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Title:
PHOTOALIGNING COPOLYMER MATERIALS
Document Type and Number:
WIPO Patent Application WO/2018/069071
Kind Code:
A1
Abstract:
The present invention relates to siloxane copolymers for the photoalignment of liquid crystals, especially for the planar orientation of liquid crystals, and which comprise at least one monomer of formula (I), and one monomer of formula (II), and to their use for optical and electro optical devices, such as, liquid crystal devices (LCDs).

Inventors:
CHAPPELLET SABRINA (FR)
LINCKER FRÉDÉRIC (FR)
Application Number:
PCT/EP2017/074853
Publication Date:
April 19, 2018
Filing Date:
September 29, 2017
Export Citation:
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Assignee:
ROLIC TECH AG (CH)
International Classes:
G02F1/1337; C08G77/00; C08G77/388
Domestic Patent References:
WO2013017467A12013-02-07
WO2000059966A12000-10-12
WO2001053384A12001-07-26
Foreign References:
US20140249244A12014-09-04
US6340506B12002-01-22
JPS59190945A1984-10-29
JPS6013740A1985-01-24
JPS58109479A1983-06-29
DE1078120B1960-03-24
GB872355A1961-07-05
JP4458299B22010-04-28
US20120114907A12012-05-10
Other References:
DATABASE WPI Week 201149, Derwent World Patents Index; AN 2011-H65369, XP002767202
"Plast. Eng.", vol. 36, 1996, MARCEL DEKKER, INC., article "Polyimides, fundamentals and applications"
Attorney, Agent or Firm:
PEDUZZI, Elisa (CH)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1 . A copolymer comprising i. A first monomer having a side chain of formula (I)

(I)

wherein

n0 is an integer from 0 to 4; and

ni is an integer from 0 to 15; and

n2 is an integer from 0 to 15; and

n3 is an integer from 1 to 15; and

X, Y each independently from each other represents H, F, CI, CN; and

S2 represents a cyclic, aromatic, straight-chain or branched, substituted or unsubstituted C C24alkylen in which one or more -C-, -CH-, -CH2- groups may be replaced by a linking group; and

E represents O, S, NH, C(C C6 alkyl), NR4, OC, OOC, OCONH, OCONR 2, SCS, SC, wherein R 2 is cyclic, straight chain or branched, substituted or unsubstituted CrC24 alkyl wherein one or more -C-, -CH-, -CH2-, group(s) may be independently from each other be replaced by a linking group; and

A represents halogen, or substituted or unsubstituted C C24 alkyl, a substituted or unsubstituted C C24 alkenyl, a substituted or unsubstituted C C24 alkynyl, or a carboxylic acid, wherein one or more, -C-, -CH-, -CH2-, group may

independently from each other be replaced by a heteroatom; and Z2 represents a chemical group having a delocalisation of its electronical density and/or inducing a delocalisation of the electronical density of its neighboring atom; and

T represents a single bond, an unsubstituted or substituted, straight-chain C C16alkyl; and

wherein * denotes the attachment to the polymer backbone; and

a second monomer having a side chain of formula (II)

(II)

Wherein

n5 and n6 are independently from each other 0, 1 or 2; and

E is a bridging group, selected from the group consisting of - O -, - CO -, - COO -, - OCO -,- NR6 -, - NR6CO -, -CO NR6-, - NR6COO -, - OCONR6-, - NR6CO NR6 -, - C=C -, -C≡ C-, - O - COO -; and

S3 is a spacer group, selected from the group consisting of single bond, straight chain or branched Ci-C24 alkylene, which is unsubstituted or substituted by cyano or halogen and wherein one or more CH2 group may be independently from each other replaced by a heteroatom or by a group selected from the group consisting of - O -, - CO -, - COO -, - OCO -,- OOC -, - NR6 -, - NR6CO -, -CO NR6-, - NR6COO -, - OCONR6-, - NR6CO NR6 -, - C=C -, -C≡ C-, - O - COO -; and

Yi and Xi are independently from each other either cyano or hydrogen; and An and Ar2 independently from each other represent a ring system of 5 to 40 atoms, wherein each ring system includes at least one unsaturation directly connected via electron conjugation (π-π bonding) to the double bond of formula (II); and

Ri , R2 , R3 and R4 are independently from each other hydrogen, a C Ci2 alkoxy, halogen, straight chain or branched, substituted or unsubstituted C C24 alkyl, nitrile; or Ri and R4 are hydrogen and R2 and R3 form together the residue of an electron- donating ring which is condensed to the Ar2 ring; and

R5, R6 and R7 are independently from each other hydrogen, a C Ci2 alkoxy, halogen, straight chain or branched, substituted or unsubstituted C C24 alkyl, nitrile or an electron-donating single substituent; or R5 and R6 form together the residue of an electron-donating ring which is condensed to the Αη ring; and

* denotes the attachment to the polymer backbone; and wherein the polymer backbone is a polysiloxane.

2. A copolymer according to claim 1 , wherein the monomers of the polymer backbone in the first monomer and in the second monomer is represented by formula (VI)

wherein

Ra represents OH, CI, substituted or unsubstituted alkoxyl group having 1 to 20 carbons, alkyl group having 1 to 20 carbons, or aryl group having 1 to 20 carbons; and

R0 represents OH, CI, a linear or branched, substituted or unsubstituted alkoxyl group having 1 to 20 carbons, in which a -C-, -CH-, -CH2- could be replaced by unsubstituted or substituted C6-C20 aryl group; and

Si represents a single bond or a straight-chain or branched, substituted or unsubstituted CrC24 alkylen, especially CrCi2 alkylen, more especially d-C8 alkylen, more especially CrC6 alkylen, most especially CrC4 alkylen, most especially CrC2 alkylen in which one or more -C-. -CH-, CH2- groups may be replaced by a linking group; and

z is an integer from 0 to 15; and

Zi represents a single bond, or substituted or unsubstituted aliphatic or alicyclic group of C3 to Ci2; and

* represents the attachment to the monomer of formula (I).

A copolymer according to claim 2 wherein

Ra, Ro, are as described above; and

Ζ represents a substituted or unsubstituted C5-C6 alicyclic group; and

Si represents a substituted or unsubstituted C C24 straight chain alkyl.

A copolymer according to claims 2 or 3 wherein

Ra, Ro, are as described above; and

Zi represents a substituted or unsubstituted cyclohexanol group or substituted or unsubstituted cyclohexanether group; and

Si represents an ethyl group.

A copolymer according to claim 1 , wherein in the first monomer having a side chain of formula (I)

n0, rii , n2, n3, S2, T are as described above; and

A represents H, one or more halogens, one or more methoxy groups or one or more carboxylic groups; and

E represents O, or S or NH; and

X, Y are H; and

Z2 is CN.

A copolymer according to claim 5, wherein in the first monomer having a side chain of formula (I)

n0, n1 ; n2, n3, S2, T, A, X, Y and Z2 are as described above; and

E represents O.

7. A copolymer according to claim 1 , wherein in the second monomer having a side chain of formula (II)

S3, Αη , Ar2, Xi , Yi , Ri , R2, 3, R4, R5, Re, R7, n5 and n6 are as defined above; and

Ei is selected from the group consisting of - O - - CO -, - COO - - OCO - - OOC -.

8. A copolymer according to claim 7 wherein in the second monomer having a side chain of formula (II)

S3 is a straight chain or branched Ci -C24 alkylene, which is unsubstituted and wherein one or more CH2 group may be independently from each other be substituted by - O -.

9. A copolymer according to claims 7 or 8, wherein

Ri , R2, R3 and R4 are independently from each other hydrogen, a C Ci2 alkoxy, halogen, straight chain or branched, substituted or unsubstituted CrC24 alkyl, nitrile.

10. A copolymer according to claims 7 or 8, wherein

Ri and R4 are hydrogen; and

R2 and R3 form together the residue of an electron-donating ring which is condensed to the Ar2 ring;

or wherein R1 ; R2 R3 and R4 are independently from each other hydrogen, a C C12 alkoxy, halogen, straight chain or branched, with halogen substituted or unsubstituted C C24 alkyl, nitrile.

1 1 . A copolymer according to any one of claims 7 to 10, wherein

R5, Re and R7 are hydrogen.

12. Composition comprising at least one first copolymer according to anyone of claims 1 to 1 1 and a second polymer or copolymer, which is not identical to the first copolymer, and optionally an additive.

13. Orientation layer, comprising at least one copolymer according to any one of claims 1 to 1 1 , or a composition according to claim 12.

14. Use of an orientation layer according to claim 13 for the orientation of liquid

crystals.

15. Optical or electro-optical unstructured or structured elements, preferably liquid crystal display cells, multi-layer and hybrid layer elements, comprising at least one linear, branched or crosslinked copolymer according to any one of claims 1 to 1 1 or a composition according to claim 12 or an orientation layer according to claim 13.

Description:
PHOTOALIGNING COPOLYMER MATERIALS

The present invention relates to copolymers for the photoalignment of liquid crystals, crosslinkable liquid crystals or non-crosslinkable liquid crystals, such as for the planar orientation of liquid crystals or for the vertical alignment of liquid crystals. Further the present invention relates to compositions comprising said copolymer, and to their use for optical and electro-optical devices, such as liquid crystal devices (LCDs).

Several photo-aligning materials are already known in the art but there is still the demand to develop new photo-aligning materials having better optical qualities for the use for example in electro-optical applications. Homopolymers have limited flexibility in fine-tuning chemical and/or electro-optical characteristics. Therefore, often blends or formulations are composed which should give access to the desired chemical and/or electro-optical properties. However, there are drawbacks due to solubility problems, phase separations, inhomogeneties on the alignment layer surface and changes in the electro-optical properties, which are undesiderable. To circumvent these drawbacks there is a need for novel photoaligning materials which solve these problems and in addition show the desired chemical and/or electro-optical properties. One example of such photo-aligning copolymer material is described in WO2013/017467 A1 .

In the present invention new photo-aligning copolymers comprising at least a first monomer having a side chain of formula (I) and a second monomer having a side chain of formulae (II) or (III) are described. These photo-aligning copolymers have superior optical properties and they give access to an economic manufacturing process and low energy consuming LCDs without decreasing the required optical properties.

SUMMARY OF THE INVENTION

It is a first object of the present invention to provide a copolymer comprising at least a first monomer having a side chain of formula (I)

And a second monomer having a side chain of formula (II) and wherein the polymer backbone is a polysiloxane.

It is a second object of the present invention to provide a composition comprising at least one said copolymer and a second polymer or copolymer which is different from the first one, and optionally an additive.

It is a third object of the present invention to provide an orientation layer comprising one said copolymer. It is a fourth object of the present invention to provide a method for preparing the orientation layer comprising said copolymer and to orientation layers obtained by such method.

It is a fifth object of the present invention to provide the use of said orientation layer to align liquid crystals in particular for liquid crystal displays, such as for the in plane switching (IPS), for the vertical alignment (VA), for the twisted nematic alignment (TN) or for the alignment of liquid crystals comprising polymerizable liquid crystals, or for the alignment of liquid crystals which are sandwiched between a pair of said orientation layers.

It is a sixth object of the present invention to provide a method for manufacturing a liquid crystal display comprising said photoaligning material or said orientation layer.

It is a seventh object of the present invention to provide optical or electro-optical unstructured or structured elements comprising said copolymer, or said orientation layer.

DETAILED DESCRIPTION OF THE INVENTION

Thus, the present invention relates in a first aspect to a copolymer comprising a first monomer having a side chain of formula (I) and a second monomer having a side chain of formulae (II) or (III) and wherein the polymer backbone is a polysiloxane, for the photoalignment of liquid crystals, such as for the planar orientation of liquid crystals or for the vertical alignment of liquid crystals:

(I)

wherein, n 0 is an integer from 0 to 4, preferably from 0 to 2; even more preferably from 0 to 1 ;

Πι is an integer from 0 to 15, preferably from 1 to 10, more preferably from 1 to 8, more preferably from 1 to 5, most preferably from 1 to 3, most preferred n-, is 1 ; n 2 is an integer from 0 to 15, preferably from 1 to 10, more preferably from 1 to 8, more preferably from 1 to 5, most preferably from 1 to 3, most preferred n 2 is 1 ; n 3 is an integer from 1 to 15, preferably from 1 to 10, more preferably from 1 to 8, more preferably from 1 to 5, most preferably from 1 to 3, most preferred n 3 is 1 ;

X, Y each independently from each other represents H, F, CI, CN;

S 2 represents a cyclic, aromatic, straight-chain or branched, substituted or

unsubstituted Ci-C 24 alkylen, especially C Ci 2 alkylen, more especially C C 8 alkylen, more especially C C 6 alkylen, most especially Ci-C 4 alkylen, most especially C C 2 alkylen in which one or more -C-, -CH-, -CH2- groups may be replaced by a linking group; wherein if more than one -C-, -CH-, -CH2- group is replaced, the linking groups may be the same or different

E represents O, S, NH, C(C C 6 alkyl), NR 2 , OC, OOC, OCONH, OCONR 4 , SCS, SC, wherein R 2 is cyclic, straight chain or branched, substituted or unsubstituted C C 24 alkyl wherein one or more -C-, -CH-, -CH2- group(s) may be independently from each other be replaced by a linking group; ore preferably E is selected from the group consisting of - O -, - CO -, - COO -, - OCO -, - OOC -, S or NH. A represents halogen, or substituted or unsubstituted CrC 24 alkyl, a substituted or unsubstituted CrC 24 alkenyl, a substituted or unsubstituted CrC 24 alkynyl, or a carboxylic acid, wherein one or more, -C-, -CH-, -CH 2 -, group may independently from each other be replaced by a heteroatom; preferably A is halogen, H, or a C C 24 alkoxy or a carboxylic acid; most preferably A is H, F, C C 6 alkyl, C C 6 alkoxy or a carboxylic acid;

Z 2 represents a chemical group having a delocalisation of its electronical density and/or inducing a delocalisation of the electronical density of its neighboring atom; and T represents a single bond, an unsubstituted or substituted, straight-chain C Ci 6 alkyl; wherein * denotes the attachment site to the polymer backbone; and a second monomer having a side chain of formula (II)

wherein Ei is a bridging group, selected from the group consisting of - O -, - CO -, - COO -, - OCO -,- NR 8 -, - NR 8 CO -, -CO NR 8 -, - NR 8 COO -, - OCONR 8 -, - NR 8 CO NR 8 -, - C=C -, -C≡C- - O - COO -; wherein R 8 is a hydrogen atom or lower alkyl.

Preferably the bridging group is selected from - O -, - CO -, - COO -, - OCO -, - C=C -, -C≡C- - O - COO -. More preferably the bridging group is selected from the group consisting of - O -, - CO -, - COO -, - OCO -, - OOC -; and

S 3 is a spacer group, selected from the group consisting of single bond, straight chain or branched C C 24 alkylene, preferably 1 to 16, more preferably 1 to 12 carbon atoms, which is unsubstituted or substituted by cyano or halogen and wherein one or more CH 2 groups may be independently from each other be replaced by a heteroatom or by a group selected from the group consisting of - O -, - CO -, - COO -, - OCO -,- NR 8 -, - NR 8 CO -, -CO NR 8 -, - NR 8 COO -, - OCONR 8 -, - NR 8 CO NR 8 -, - C=C -, - C≡C- - O - COO -; wherein R 8 is a hydrogen atom or lower alkyl. More preferably one or more CH 2 groups are replaced by a heteroatom or by a group selected from the group consisting of - O -, - CO -, - COO -, - OCO -, - C=C -, -C≡C- - O - COO -, most preferably one CH 2 group is substituted by a heteroatom, even more preferably one CH 2 group is substituted by oxygen; and

Yi and Xi are independently from each other either cyano or hydrogen; and An and Ar 2 independently from each other represent a ring system of 5 to 40 atoms, wherein each ring system includes at least one unsaturation directly connected via electron conjugation (π-π bonding) to the double bond of formula (II); and wherein the ring system may be unsubstituted or mono- or poly-substituted by a halogen atom, a hydroxyl group and/or a polar group like nitro, nitrile or a carboxy group, and/or a cyclic, straight-chain or branched alkyl residue having from 1 to 30 carbon atoms, which is unsubstituted, mono- or poly-substituted by methyl, fluorine and/or chlorine, wherein one or more, preferably non-adjacent -CH2- groups independently may be replaced by a group selected from -0-, -CO-

-CO-O-, -O-CO-, -NR 9 -, - NR 9 -CO-, -CO- NR 9 -, - NR 9 -CO-0-, -O-CO- NR 9 -, - NR 9 -CO- NR-, -CH=CH-, -C≡C-, -0-CO-O- and -Si(CH 3 )2-0-Si(CH 3 )2-, an aromatic or an alicyclic group, wherein R 9 is a hydrogen atom or lower alkyl; and/or an acryloyloxy, alkoxy, alkylcarbonyloxy, alkyloxocarbonyloxy, methacryloyloxy, vinyl, allyl, vinyloxy and/or allyloxy group, having from 1 to 20 carbon atoms, preferably having from 1 to 10 carbon atoms; and

Ri , R 2 , R3 and R 4 are independently from each other hydrogen, a C 1 -C 12 alkoxy, halogen, straight chain or branched, with halogen substituted or unsubstituted CrC 24 alkyl; nitrile; or

Ri and R 4 are hydrogen and R 2 and R 3 form together the residue of an electron- donating ring which is condensed to ring Ar 2 ; and R 5 , R 6 and R 7 are independently from each other hydrogen, a C Ci 2 alkoxy, halogen; straight chain or branched, with halogen substituted or unsubstituted C C 24 alkyl; nitrile; or an electron-donating single substituent; or

R 5 and R 6 form together the residue of an electron-donating ring which is condensed to the Αη ring; and n 5 and n 6 independently from each other represents an integer from 0 to 2; and * denotes the attachment site to the polymer backbone; and the polymer backbone is a polysiloxane. In the context of the present invention the term "copolymer" denotes a polymer having a polymer backbone, wherein the polymer backbone can be the same or can be different and wherein the side chains of the copolymer are different. The copolymer according to the present invention comprises at least one first monomer having a side chain of formula (I) and a second monomer having a side chain of formulae (II) or of formula (III). The copolymers according to the present invention can be linear, branched or crosslinked. The term copolymer has also the meaning of co-oligomer.

Copolymers according to the various non-limiting embodiments herein may have a polymeric or oligomeric form of an alternating copolymer, a periodic copolymer, a random copolymer, a statistical copolymer, a block copolymer, a graft copolymer, a linear copolymer, a gradient copolymer, a branched copolymer, a hyperbranched copolymer, a dendritic copolymer, a star copolymer, a brush copolymer and a comb polymer. The copolymers according to the present invention may have the same or different polymer backbone. In a preferred embodiment, the copolymers of the present invention have the same polymer backbone and the monomers differ in their side chains. In a preferred embodiment the copolymers according to the present invention comprise at least one first monomer having a side chains according to formula (I) and at least one second monomer having a side chain according to formulae (II) or (III). The order and configurations of the side chains is not limited to any preferred embodiment. Hence, the copolymer can have polymeric chains which have only monomers having a side chain of formula (I) and these chains are linked to other chains which have only monomers having a side chain of formula (II) or of formula (III). These linkages or forms can be as defined above. Or the copolymer according to the present invention can have at least one monomer having a side chain of formula (I) and at least one monomer having a side chain of formulae (II) or (III) wherein the monomers are randomly arranged. In specific non-limiting embodiments, the copolymers may include a polymer chain where different sections may have different forms, such as, for example, a random polymeric section and a block polymeric section. Formation of copolymers having one or more of the recited forms may be accomplished using polymerization methods know in the art, including, but not limited to, addition polymerization, step-growth polymerization, condensation polymerization, controlled living polymerization, anionic polymerization, cationic polymerization,

photopolymerization, radical polymerization, reversible addition-fragmentation chain transfer polymerization (RAFT) and metathesis polymerisation.

The term "linking group", as used in the context of the present invention is preferably selected from an unsubstituted or substituted alicyclic group, preferably cyclohexylen, or an unsubstituted or substituted aromatic group, single bond, heteroatom, cationic carbohydrogen group such as - depending - (C+) -, - O -, - CO, - arylen-

, - CO - O -, - O - CO - , - N = , - CN, - NR 0 -, - NR 0 - CO -, - CO - NR 0 -,- NR 0 - CO - O -, - O - CO - NR 10 -, - NR 10 - CO - NR 10 -, - CH = CH -, - C≡ C -, - O - CO - 0-, and -Si(CH 3 ) 2 - O - Si(CH 3 ) 2 - , and wherein:

R 0 represents a hydrogen atom or d-C 6 alkyl;

with the proviso that oxygen atoms of linking groups are not directly linked to each other.

Substituents of the substituted alicyclic or aromatic group of the linking groups may be one or more and are preferably halogene, such as fluor, chloro, bromo, iodo, and preferably fluoro and/chloro and more preferably fluor; or CrC 6 alkoxy, such as preferably methoxy, or trifluoromethyl.

It is understood that the wording "each ring system includes at least one unsaturation directly connected via electron conjucation (π-π bonding) to the double bond" indicates that each ring system An and Ar 2 contains at least one unsaturated bond, i.e. double bond, that is directly linked to the double bond in formula (II) thereby extending the electron conjugation.

In a preferred embodiment ring systems An and Ar 2 are a carbocyclic or heterocyclic ring group selected from a monocyclic ring of four to six atoms, ot at least two adjacent monocyclic rings of five or six atoms, or a fused bicyclic ring system of eight, nine or ten atoms, or a fused tricyclic ring system of thirteen or fourteen atoms. More preferably ring systems An and Ar 2 are selected from pyrimidine, pyridine, thiophenylene, furanylene, phenanthrylene, naphthylene, or phenylene.

More preferably ring systems An is selected from primidine, pyridine, pyridine cation, thiophenylene, furanylene, pheneanthrylene, 9,10-dihydrophenanthrene, pyrene, naphtylene, 9H-fluorene, 9H-fluoren-9-one, 9,9-dimethyl-9H-fluorene or phenylene, and A1 is selected from cyclohexane, cyclohexene, cyclohexadiene, pyrimidine, pyridine, thiophenylene, furanylene, phenanthrylene, naphthylene or phenylene or a steroidal skeleton or a rod shaped ajhacent aromatic and/or aromatic/alicycic group.

In a yet a further embodiment

An is a ring system of formula (IV):

a (iv)

and

Ar 2 is a ring system of formula (V):

( cy— z 3 -)^ 2

a (V)

wherein:

C C 2 each independently are a substituted or unsubstituted non-aromatic of 3 to 40 atoms, or an aromatic, optionally substituted, carbocyclic or heterocyclic group of 5 to 14 atoms, preferably connected to each other at the opposite positions via the bridging groups Z and Z 2 , and wherein the substituents of substituted C , C 2 are R 5 , R 6 or R 7 for ring An and R , R 2 , R 3 or R 4 for ring Ar 2 ; and

Z 3 , Z 4 each independently are a single bond or a group selected

from -CH(OH)-, -0-, -CH 2 (CO)-, -SO-, -CH 2 (SO)-, -S0 2 -, -CH 2 (S0 2 )-, -COO-, -OCO- , -COF 2 -, -CF 2 CO-, -S-CO-, -CO-S-, -SOO-, -OSO-, -CH 2 -CH 2 -, -0-CH 2 -,

-CH 2 0-, -CH=CH-, -C≡S-, -SH=CH-COO-, -OCO-CH=CH-, -CH=N-, -C(CH 3 )=N-, -0-CO-0-, -N=N- , or a short alkyl spacer of 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms; a is 0, 1 , 2 or 3, preferably a is 0 or 1 , more preferably 0; with the proviso that C 2 , which is directly connected to the double bond, is unsaturated and conjugated to it.

The term "connected to each other at the opposite positions via the bridging groups Z 3 and Z 4 " means that five- and six-membered rings are preferably linked in 1 ,3- or 1 ,4- position and not in neighbouring 1 ,2-position. Analogous linking pattern in other e.g. higher membered rings will be obvious to a skilled person.

It is understood that ring system Ar 2 has an analogous structure to ring system Αη of formula (IV) with the exception that group Ar 2 carries a terminal group. Thus, for a = 0 group C 2 represents the terminal group and for a > 0 groups C are connected via the bridging groups Z 4 , with the final group C being the terminal group. Thus, for a = 1 ring system A 2 has the following formula c^z^c 2

Likewise for a = 2 or 3 ring system A 2 has the following formula

c^-z^ c 1 - z^- c 2

1 , 2

Preferably C , C 2 in formulae (IV) and (V) independently from each other have one of the following meanings:

wherein L is halogen, hydroxyl, and/or a polar group such as nitrile cyano or carboxy, and/or acryloyloxy, alkoxy, such as methoxy, ethoxy, propoxy, alkylcarbonyloxy, alkyloxocarbonyloxy, methacryloyloxy, vinyl, vinyloxy, allyl, allyloxy, and(or a cyclic, straight-chain or branched alkyl residue, which is unsubstituted, mono- or poly- substituted by fluorine and/or chlorine, and/or a silane group, and/or a siloxane group, wherein the alkyl residue has from 1 to 20 C-atoms, wherein one or more, preferably non-adjacent CH2 groups mai independently be replaced by a group selected from -0-, -CO- -CO-0-, -0-CO-, -CH=CH-, -C≡C-, -0-CO-0-, Si(CH 3 )2-0-Si(CH 3 )2-, preferably L is methoxy, halogen, CF 3 or hydrogen; u1 is 0, 1 , 2, 3, or 4; u2 is 0, 1 , 2, or 3; and u3 is 0, 1 , or 2; with the proviso that C 2 , which is directly connected to the double bond, is unsaturated and conjugated to it. More preferably C\ C 2 are phenanthryl, phenanthrylene, biphenyl, biphenylene, naphthyl, naphthylene, cyclohexyl, cyclohexylen, phenyl or phenylene, pyridine, pyridinylene; preferably naphthyl or naphthylene, phenyl or phenylene, pyridine or pyridinylene.

Preferably Z 3 , Z 4 in formulae (IV) and (V) each independently are a single bond or a bridging group most preferably selected from -CH(OH)-, -0-, -CH 2 (CO)-, -COO-, -OCO-, -COF 2 -, -CF 2 CO-, -CH 2 -CH 2 -, -0-CH 2 -, -CH20-, -CH=CH-, -OCO-CH=CH-, -CH=N-, -C(CH 3 )=N-, -0-CO-0-, -N=N- , or a short alkyl spacer of 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms.

More preferably Z 3 , Z 4 each independently are a single bond, -0-, -CH 2 (CO)-, -C00-, - 0C0-, -CH 2 -CH 2 -, -OCO-CH=CH-, -N=N- , or a short alkyl spacer of 1 to 3 carbon atoms.

In the context of the present invention an electron-donating ring which is condensed to the ring Ar 2 is preferably unsubstituted or substituted -X 2 -Ci-C 24 alkylene-(X 3 ) 0 O M - , or more especially unsubstituted or substituted -X 2 -C 2 -C 24 alkylene-(X 3 ) 0 O M -, wherein X 2 and X 3 are independently from each other selected from a single bond, -0-, -S-, Se, - N-, -NH- and -NRn , wherein Rn is hydrogen atom or a straight-chain or branched alkyl or alkylene group, having from 1 to 12, more preferably from 1 to 6 carbon atoms, wherein one or more, preferably non-adjacent -CH 2 - groups may be independently unreplaced or replaced by a linking group, preferably selected

from -0-, -CO-, -C0-0-, -0-C0-, -C=C-, -C≡C; more preferably Rn is a hydrogen atom or methyl; or preferably is an optionally substituted CrC 6 alkyl, and more preferably Ri i is hydrogen; and within the above given preferences, wherein the substituted -X 2 - Ci-C 24 alkylene-(X 3 )o on - ! is preferably CrC 6 alkyl, such as methyl or ethyl, which substitutes a CrC 24 alkylene postion. Preferred X 2 and X 3 are identical, more preferably X 2 and X 3 are -O- . Further preferred -X 2 -C 1 -C 24 alkylene-(X 3 )o on- ! is -X 2 -C

Ci 2 alkylene-(X 3 )o on-, , more preferred -X 2 -Ci-C 6 alkylene-(X 3 )o or i-, and most preferred -X 2 -Ci-C 3 alkylene-(X 3 )o or i-, especially 1 ,3-propylene, 1 ,2-ethylene, methylene,- CH(CH 3 )CH(CH 3 )-, -CH 2 CH(CH 3 )CH 2 -. More preferred X 1 and X 2 are identical and are -O-propylene-0-, -O-ethylene-0-, -ethylene-O-, -O-methylene-0-, - OCH(CH 3 )CH(CH 3 )-0-, -0-CH 2 CH(CH 3 )CH 2 -0-. In the context of the present invention the wording "electron-donating single

substituent" is preferably selected from the groups CrC- 24 alkyl, preferably methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert,-butyl, pentyl, isopentyl, hexyl, iso-hexyl; or -X 4 -Ci-C 24 alkyl, preferably -X 4 -CrCi 2 alkyl, more preferably -X 4 -CrC 6 alkyl, most preferably -X 4 -CrC 3 alkyl, wherein X 4 is a single bond, -0-, -S-, Se, -N-, -NH- and -NR 11 ; preferably -0-, and wherein is as described above and within the above given preferences; preferably -O-metyl, -O-ethyl, -O-propyl, -O-isopropyl, -O-butyl, -O-sec.-butyl, -O-tert- butyl, -O-pentyl, -O-isopentyl, -O-hexyl or -O-iso-hexyl; or -X 4 -CrC 24 alkylen-aryl, preferably -O-benzylen, -O-methylen-phenyl, -O-ethylen- phenyl; or -0-CF 3 ; with the proviso that in the residue C-i-C 24 alkyl, one or more C-atom, CH- or CH 2 -group may be replaced by a linking group. Preferred C-i-C 24 alkyl residue is Ci-C 12 alkyl, more pereferably CrC 6 alkyl, and more preferred are methyl, ethyl, propyl, isopropyl, butyl, tert-butyl sec-butyl, iso-pentyl, pentyl, hexyl or isohexyl and most preferred are methyl and ethyl. Most preferred electron-donating single substituent is methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert.-butyl, -0-CF 3 , -O-benzylen, -O-methylen-phenyl, -O-methyl, -O-ethyl,—O-propyl, -S-methyl, -S-ethyl,— S-propyl, - NRn-methyl, -NRn-ethyl,— NRn-propyl, wherein Rn is hydrogen or methyl.

In the context of the present invention the term "polysiloxane" means any polymer, copolymer or oligomer, comprising a functional group with the Si-O-Si linkage. The polysiloxane according to the present invention may be linear, branched or crosslinked. Polysiloxanes are synthesized by methods well-known in the art.

Most preferred are polysiloxane backbones comprising monomers of formula

wherein R a represents OH, CI, substituted or unsubstituted alkoxyl group having 1 to 20 carbons, alkyl group having 1 to 20 carbons, or aryl group having 1 to 20 carbons; and

Si represents a single bond or a straight-chain or branched, substituted or

unsubstituted Ci-C 24 alkylen, especially C Ci 2 alkylen, more especially C C 8 alkylen, more especially C C 6 alkylen, most especially C C 4 alkylen, most especially C C 2 alkylen in which one or more -C-. -CH-, CH 2 - groups may be replaced by a linking group; and z is an integer from 0 to 15, preferably from 1 to 10, more preferably from 1 to 8, more preferably from 1 to 5, even more preferably from 1 to 3, most preferred n is 1 ; and

Ζ represents a single bond, or substituted or unsubstituted aliphatic or alicyclic group of C 3 to Ci 2 , more preferably C 3 to Ci 0 , even more preferably C 5 to C 8 , most preferably C 5 to C 6 ; and

R 0 represents OH, CI, a linear or branched, substituted or unsubstituted alkoxyl group having 1 to 20 carbons, in which a -C-, -CH-, -CH 2 - could be replaced by unsubstituted or substituted C 6 -C 20 aryl group; and wherein * denotes the attachment site to the side chains.

Preferred are polysiloxanes having a backbone comprising monomers according to formula (VI) wherein Ζ represents a substituted or unsubstituted C 5 -C 6 alicyclic group and Si represents a substituted or unsubstituted C C 24 straight chain alkyl. More preferred are polysiloxanes having a polymer backbone comprising monomers according to formula (VI) wherein Ζ represents a substituted or unsubstituted cyclohexanol group or substituted or unsubstituted cyclohexanether group and Si represents an ethyl group.

The polysiloxane backbone comprising monomers according to formula (VI) is a polymer chain which can be linear, branched or crosslinked. The polymer chain is at least once substituted with a side chain of formula (I) and at least once substituted with a side chain of formulae (II) or (III). Not all siloxane monomers of the polysiloxane backbone comprising monomers according to formula (VI) must be substituted by a side chain, as long as at least one monomer of the polysiloxane backbone comprising monomers according to formula (VI) is substituted by a side chain of formula (I) and at least another monomer of the polysiloxane backbone comprising monomers according to formula (VI) is substituted by a side chain of formula (II) or (III).

In the copolymer according to the present invention, the polymer backbone may comprise the same or different polymer backbones comprising monomers according to formula (VI).

In the context of the present invention the term "alkyl" includes straight-chain and branched alkyl, as well as saturated and unsaturated groups. The term "alkyl" has the meaning of unsubstituted or substituted alkyl, wherein substituted alkyl has also the meaning of alkylen. Alkyl, alkyloxy, alkoxy, alkylcarbonyloxy, acryloyloxyalkoxy, acryloyloxyalkyl, acryloyloxyalken, alkyloxycarbonyloxy, alkylacryloyloxy,

methacryloyloxyalkoxy, methacryloyloxyalkyl, methacryloyloxyalken,

alkylmethacryloyloxy, alkylmethacryloyloxy, alkylvinyl, alkylvinyloxy and alkylallyloxy and alkylene, as used in the context of the present invention denote with their alkyl residue, respectively their alkylene residue, a cyclic, straight-chain or branched, substituted or unsubstituted alkyl, respectively alkylene, in which one or more, preferably non-adjacent, -C-, -CH-, or -CH2- group may be unreplaced or replaced by a linking group, preferably replaced by -O-, NH, -COO, OCO.

Further, in the context of the present invention "alkyl" is branched or straight chain, unsubstituted or substituted alkyl, preferably CrC 40 alkyl, especially C C 30 alkyl, preferably C C 20 alkyl, more preferably C Ci 6 alkyl, most preferably C 1 -C 10 alkyl and especially most preferably C C 6 alkyl. Accordingly alkylen is for example CrC 40 alkylen, especially Ci-C 30 alkylen, preferably Ci-C 20 alkylen, more preferably C Ci 6 alkylen, most preferably C 1 -C 1 0 alkylen and especially most preferably C C 6 alkylen. In the context of the present invention the definitions for alkyl given below, are applicable to alkylene in analogy.

Ci-C 6 alkyl is for example methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert.-butyl, pentyl or hexyl. Ci -C 10 alkyl is for example methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert.-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl. C1 -C16 alkyl is for example methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert.-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl or hexadecyl.

C1 -C20 alkyl is for example methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert.-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nondecyl, eicosyl.

Ci -C 24 alkyl is for example methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert.-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nondecyl, eicosyl.

C1 -C30 alkyl is for example methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert.-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nondecyl, eicosyl, heneicosyl, tricosyl, tetracosy, pentacosyl, hexacosdy, heptacosyl, octacosyl, nonacosy or triacontyl.

C1 -C40 alkyl is for example methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert.-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nondecyl, eicosyl, heneicosyl, tricosyl, tetracosy, pentacosyl, hexacosdy, heptacosyl, octacosyl, nonacosy, triacontyl or tetracontyl.

CrC 6 alkoxy is for example methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec.-butoxy, tert.-butoxy, pentoxy or hexoxy.

C1 -C20 acryloyloxyalkylene, preferably C1 -C10 acryloyloxyalkylene,

C C 6 acryloyloxyalkylene is for example acryloyloxymethylen, acryloyloxyethylene, acryloyloxypropylene, acryloyloxyisopropylene, acryloyloxybutylene, acryloyloxy-sec- butylene, acryloyloxypentylene, acryloyloxyhexylene, acryloyloxyheptylene,

acryloyloxyoctylene, acryloyloxynonylene, acryloyloxydecylene, acryloyloxyundecylene, acryloyloxydodecane, acryloyloxytridecylene, acryloyloxytetradecylene,

acryloyloxypentyldecane, acryloyloxyhexadecylene, acryloyloxyheptadecylene, acryloyloxyoctadecylene, acryloyloxynondecylene, acryloyloxyeicosylene.

Ci-C 20 methacryloyloxyalkylene, preferably C Ci 0 methacryloyloxyalkylene, C C 6 methacryloyloxyalkylene is for example methacryloyloxymethylen,

methacryloyloxyethylene, methacryloyloxypropylene, methacryloyloxyisopropylene, methacryloyloxybutylene, methacryloyloxy-sec.-butylene, methacryloyloxypentylene, methacryloyloxyhexylene, methacryloyloxyheptylene, methacryloyloxyoctylene, methacryloyloxynonylene, methacryloyloxydecylene, methacryloyloxyundecylene, methacryloyloxydodecane, methacryloyloxytridecylene, methacryloyloxytetradecylene, methacryloyloxypentyldecane, methacryloyloxyhexadecylene,

methacryloyloxyheptadecylene, methacryloyloxyoctadecylene,

methacryloyloxynondecylene, methacryloyloxyeicosylene.

Ci-C 20 acryloyloxyalkoxy, preferably CrCi 0 acryloyloxyalkoxy, d- C 6 acryloyloxyalkoxy is for example acryloyloxymethoxy, acryloyloxyethoxy, acryloyloxypropoxy,

acryloyloxyisopropoxy, acryloyloxybutoxy, acryloyloxy-sec.-butoxy, acryloyloxypentoxy, acryloyloxyhexoxy, acryloyloxyheptoxy, acryloyloxyoctoxy, acryloyloxynonoxy, acryloyloxydecoxy, acryloyloxyundecoxy, acryloyloxydodecanoxy,

acryloyloxytridecyloxy. Ci-C 20 methacryloyloxyalkoxy, preferably C 1 -C 1 0 methacryloyloxyalkoxy, C C 6 methacryloyloxyalkoxy is for example methacryloyloxymethoxy,

methacryloyloxyethoxy, methacryloyloxypropoxy, methacryloyloxyisopropoxy, methacryloyloxybutoxy, methacryloyloxy-sec.-butoxy, methacryloyloxypentoxy, methacryloyloxyhexoxy, methacryloyloxyheptoxy, methacryloyloxyoctoxy,

methacryloyloxynonoxy, methacryloyloxydecoxy, methacryloyloxyundecoxy, methacryloyloxydodecanoxy, methacryloyloxytridecyloxy.

An aliphatic group is for example a saturated or unsaturated, mono-, bi-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, deca-valent alkyl, alkylene, alkyloxy, alkylcarbonyloxy, acryloyloxy, alkylacryl, alkylmethacryl, alkyl(en)acryl(en),

alkyl(en)methacryl(en), alkyloxycarbonyloxy, alkyloxycarbonyloxy methacryloyloxy, alkylvinyl, alkylvinyloxy or alkylallyloxy, which may comprise one or more heteroatom and/or bridging group.

An alicyclic group is preferably a non-aromatic group or unit and may be substituted or unsubstituted. Preferably an alicyclic group is a non-aromatic carbocyclic or

heterocyclic group and represents for example ring systems, with 3 to 30 carbon atoms, as for example cyclopropane, cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexene, cyclohexadiene, decaline, tetrahydrofuran, dioxane, pyrrolidine, piperidine or a steroidal skeleton such as cholesterol. Preferred alicyclic group is cyclohexane. Substituents of an alicyclic group are halogene, preferably fluor or/and chloro, or C C 6 alkoxy which is substituted or unsubstituted with halogen, leading to the formation of an ether group, preferably methoxy or triflourmethyl or one or more hydroxyl groups. Preferred is a cyclohexanol group or a cyclohexan group substituted with a CrC 6 alkoxy, which is then called in the context of the present invention a cycloxanether group.

The term "aromatic", as used in the context of the present invention, preferably denotes unsubstituted or substituted carbocyclic and heterocyclic groups, incorporating five, six, ten ot 14 ring atoms, e.g. furan, benzene or phenylene, pyridine, pyrimidine, naphthalenen, which may form ring assemblies, such as biphenylene or triphenylen, which are uninterrupted or interrupted by at least a single heteroatom and/or at least a single bridging group; or fused polycyclic systems, such as phenanthrene, tetraline. Preferably aromatic group are benzene, phenylene, biphenylene or triphenylen. More preferred aromatic group is benzene, phenylene and biphenylene. Especially preferred substituents of an aromatic group or of a carbocyclic and heterocyclic groups are halogene, preferably fluor or/and chloro, C C 6 alkoxy, preferably methoxy or triflourmethyl.

A carbocyclic or heterocyclic aromatic or alicyclic group incorporates preferably three, four, five, six, ten or 14 ring atoms, as for example aziridin, epoxy, cyclopropyl, furan, pyrollidin, oxazolin, imidazol, benzene, pyridine, triazine, pyrimidine, naphthalene, phenanthrene, biphenylene or tetraline units, preferably naphthalene, phenanthrene, biphenylene or phenylene, more preferably naphthalene, biphenylene or phenylene, and most preferably phenylene.

Especially preferred substituents of carbocyclic and heterocyclic aromatic or alicyclic groups are halogene, preferably fluor or/and chloro, C C 6 alkoxy, preferably methoxy or triflourmethyl.

The unsubstituted or substituted carbocyclic or heterocyclic aromatic or alicyclic group is for example unsubstituted or mono- or poly-substituted. Preferred substitutents of carbocyclic or heterocyclic aromatic groups are at least one triflourmethyl, halogen, such as fluor, chloro, bromo, iodo, especially fluor or/and cloro, and more especially fluor; hydroxyl, a polar group, acryloyloxy, alkylacryloyloxy, alkoxy, especially methoxy, ethoxy, propoxy; alkylcarbonyloxy, alkyloxycarbonyloxy, alkyloxocarbonyloxy, methacryloyloxy, vinyl, vinyloxy and/or allyloxy group, wherein the alkyl residue has preferably from 1 to 20 carbon atoms, and more preferably having from 1 to 10 carbon atoms. Preferred polar groups are nitro, nitrile or a carboxy group, and/or a cyclic, straight-chain or branched Ci-C 30 alkyl, which is unsubstituted, mono- or poly- substituted. Preferred substitutents of Ci-C 30 alkyl are methyl, fluorine and/or chlorine, wherein one or more, preferably non-adjacent, -C-, -CH-, -CH 2 - group may

independently of each other be replaced by a linking group. Preferably, the linking group is selected from -0-, -CO-, -COO- and/or -OCO-.

A monocyclic ring of five or six atoms is for example furan, benzene, preferably phenylene, pyridine, pyrimidine, pyridine cation, pyrimidine cation. A bicyclic ring system of eight, nine or ten atoms is for example naphthalene, biphenylene or tetraline.

A tricyclic ring system of thirteen or fourteen atoms is for example phenanthrene. The term "phenylene", as used in the context of the present invention, preferably denotes a 1 ,2-, 1 ,3- or 1 ,4-phenylene group, which is optionally substituted. Especially preferred substituents of phenylene are halogene, preferably fluor or/and chloro, C C 6 alkoxy, preferably methoxy or triflourmethyl. It is preferred that the phenylene group is either a 1 ,3- or a 1 ,4-phenylene group. 1 ,4-phenylene groups are especially preferred. The term "halogen" denotes a chloro, fluoro, bromo or iodo substituent, preferably a chloro or fluoro substituent, and more preferably fluoro. The term "heteroatom", as used in the context of the present invention is a neutral, anionic or cationic heteroatom and primarily denotes oxygen, sulphur and nitrogen, halogene, such as fluoro, chloro, bromo, iodo, and more preferably fluoro and/or chloro, and most preferably fluoro; preferably halogene, oxygen and nitrogen, in the latter case primary amine, secondary amine, tertiary amine or quartarnary ammonium cation, preferably in the form of -NH-.

The term "optionally substituted" as used in the context of the present invention primarily means substituted by lower alkyl, such as CrC 6 alkyl, lower alkoxy, such as CrC 6 alkoxy, hydroxy, halogen such as fluorine or chlorine or by a polar group such as a cyano group.

With respect to straight chain or branched alkyl, alkylene, alkoxy, alkylcarbonyloxy, acryloyloxyalkoxy, acryloyloxyalkyl, acryloyloxyalkene, alkyloxycarbonyloxy, alkylacryloyloxy, methacryloyloxyalkoxy, methacryloyloxyalkyi, methacryloyloxyalkene, alkylmethacryloyloxy, alkylmethacryloyloxy, alkylvinyl, alkylvinyloxy, alkylallyloxy and alkylene groups it is repeatedly pointed out that some or several of the -C-, -CH- , -CH 2 - groups may be replaced e.g. by heteroatoms, but also by other groups, preferably bridging groups. In such cases it is generally preferred that such

replacement groups are not directly linked to each other. It is alternatively preferred that heteroatoms, and in particular oxygen atoms are not directly linked to each other.

In a preferred embodiment, the first aspect of the invention relates to copolymer for the photoalignment of liquid crystals, especially for the planar orientation of liquid crystals, and which comprises at least one monomer having a side chain of formula (I):

wherein

n 0, n 1 ; n 2 , n 3 , S 2 , A, T are as described above; and

E represents O, or S or NH;

X, Y are H; and

Z 2 is CN; and

* denotes the attachment site to the polymer backbone; and a second monomer having a side chain of formula (II)

wherein Ei , n 5 , n 6 , Ri , R 2 , R3, R 4 and R 5 have the same meaning as described above; and either Xi or Yi is cyano and the other is hydrogen; and S 3 is a straight chain or branched CrC 24 alkylene, more preferably a C 1 -C 12 alkylene, even more preferably a C 4 -Ci 2 alkylene, wherein one or more -CH 2 - groups may be independently from each other be replaced by a heteroatom or by a group selected from the group consisting of - O -, - CO -, - COO -, - OCO -,- NR 8 -, - NR 8 CO -, - CO NR 8 -, - NR 8 COO -, - OCONR 8 -, - NR 8 CO NR 8 -, - C=C -, -C≡C- - O - COO - ; wherein R 8 is a hydrogen atom or lower alkyl; and

* denotes the attachment site to the polymer backbone; and wherein the polymer is a polysiloxane.

In another preferred embodiment, the first aspect of the invention relates to a copolymer for the photoalignment of liquid crystals, especially for the planar orientation of liquid crystals, and which comprises at least one monomer having a side chain of formula (I):

wherein n 0, n 1 ; n 2 , n 3 , S 2 , T are as described above; and

A represents H, one or more halogens, one or more methoxy groups or one or more carboxylic groups; and E represents O, or S or NH ; X, Y are H ; and Z 2 is CN; and

* denotes the attachment site to the polymer backbone; and a second monomer having a side chain of formula (I I I)

wherein

Ei, n 5 , n 6 , Ri, R 2 , R3, R 4 and R 5 have the same meaning as described above; and; either Xi or Yi is cyano and the other is hydrogen; and

S 3 is a straight chain or branched CrC 24 alkylene, more preferably a C 1 -C 12 alkylene, even more preferably a C4-C 12 alkylene, wherein one or more -CH 2 - groups may be independently from each other be replaced by a heteroatom or by a group selected from the group consisting of - O - - CO - - COO - - OCO - - NR 8 -, - NR 8 CO - - CO NR 8 - - NR 8 COO -, - OCONR 8 - - NR 8 CO NR 8 -, - C=C - -C≡C- - O - COO - ; wherein R 8 is a hydrogen atom or lower alkyl; and

* denotes the attachment site to the polymer backbone; and wherein the polymer is a polysiloxane. In another preferred embodiment, the first aspect of the invention relates to a copolymer for the photoalignment of liquid crystals, especially for the planar orientation of liquid crystals, and which comprises one monomer having a side chain of formula (I):

wherein no, ni , n 2 , n 3 , S 2 , T are as described above; and

A represents H, halogens, methoxy groups or carboxylic groups; and

E represents O; and

X, Y are H; and

Z 2 is CN; and

* denotes the attachment site to the polymer backbone; and a second monomer having a side chain of formula (III)

wherein E 1 ; n 5 , n 6 , Ri , R 2 , R 3 , R 4 and R 5 have the same meaning as described above; and; either X ! or is cyano and the other is hydrogen; and

S 3 is a straight chain or branched C C 24 alkylene, more preferably a C Ci 2 alkylene, even more preferably a C 4 -Ci 2 alkylene, wherein one or more -CH 2 - groups may be independently from each other be replaced by a heteroatom or by a group selected from the group consisting of - O - - CO - - COO - - OCO - - NR 8 -, - NR 8 CO - - CO NR 8 - - NR 8 COO -, - OCONR 8 -, - NR 8 CO NR 8 -, - C=C - -C≡C- - O - COO - ; wherein R 8 is a hydrogen atom or lower alkyl; and;

* denotes the attachment site to the polymer backbone; and wherein the polymer is a polysiloxane. In a further preferred embodiment, the first aspect of the invention relates to a copolymer for the photoalignment of liquid crystals, especially for the planar orientation of liquid crystals, and which comprises one monomer having a side chain of formula (la):

(A),

(la) wherein n 0 and T are as described above; and

A represents H, halogens, methoxy groups or carboxylic groups; and E represents O; and X, Y are H; and Z 2 is CN; and

* denotes the attachment site to the polymer backbone; and a second monomer having a side chain of formula (II)

(II)

wherein

Ei, n 5 , n 6 , Ri, R 2 , R3, R 4 and R 5 have the same meaning as described above; and either X ! or is cyano and the other is hydrogen; and

S 3 is a straight chain or branched C C 24 alkylene, more preferably a C 1 -C 12 alkylene, even more preferably a C 4 -Ci 2 alkylene, wherein one or more -CH 2 - groups may be independently from each other be replaced by a heteroatom or by a group selected from the group consisting of - O -, - CO -, - COO -, - OCO -,- NR 8 -, - NR 8 CO -, - CO NR 8 -, - NR 8 COO -, - OCONR 8 -, - NR 8 CO NR 8 -, - C=C -, -C≡C- - O - COO - ; wherein R 8 is a hydrogen atom or lower alkyl; and * denotes the attachment site to the polymer backbone; and wherein the polymer is a polysiloxane.

In a yet further preferred embodiment, the first aspect of the invention relates to a copolymer for the photoalignment of liquid crystals, especially for the planar orientation of liquid crystals, and which comprises one monomer having a side chain of formula

(la):

(la) wherein n 0 and T are as described above; and A represents H, halogens, methoxy groups or carboxylic groups; and E represents O; and

X, Y are H ; and Z 2 is CN; and * denotes the attachment site to the polymer backbone; and a second monomer having a side chain of formula (I I I)

wherein

Ei, n 5 , n 6 , Ri, R 2 , R3, R 4 and R 5 have the same meaning as described above; and; either Xi or Yi is cyano and the other is hydrogen; and S 3 is a straight chain or branched CrC 24 alkylene, more preferably a C 1 -C 12 alkylene, even more preferably a C4-C 12 alkylene, wherein one or more -CH 2 - groups may be independently from each other be replaced by a heteroatom or by a group selected from the group consisting of - O -, - CO -, - COO -, - OCO -,- NR 8 -, - NR 8 CO -, - CO NR 8 -, - NR 8 COO -, - OCONR 8 -, - NR 8 CO NR 8 -, - C=C -, -C≡C- - O - COO - ; wherein R 8 is a hydrogen atom or lower alkyl; and; * denotes the attachment site to the polymer backbone; and wherein the polymer is a polysiloxane. In a yet further preferred embodiment, the first aspect of the invention relates to a copolymer for the photoalignment of liquid crystals, especially for the planar orientation of liquid crystals, and which comprises one monomer having a side chain of formula (la):

(la) wherein n 0 and T are as described above; and

A represents H, halogens, methoxy groups or carboxylic groups; and E represents O; and X, Y are H; and Z 2 is CN; and

* denotes the attachment site to the polymer backbone; and a second monomer having a side chain of formula (III)

wherein

E 1 ; n 5 , n 6 , S 3 , R 4 and R 5 have the same meaning as described above; and; either X ! or is cyano and the other is hydrogen; and

Ri , R 2 and R 3 are independently from each other H or -CF 3 or methoxy; and

* denotes the attachment site to the polymer backbone; and wherein the polymer is a polysiloxane.

In a yet further preferred embodiment, the first aspect of the invention relates to a copolymer for the photoalignment of liquid crystals, especially for the planar orientation of liquid crystals, and which comprises one monomer having a side chain of formula (la):

(la) wherein n 0 and T are as described above; and

A represents H, halogens, methoxy groups or carboxylic groups; and E represents O; and X, Y are H; and Z 2 is CN; and

* denotes the attachment site to the polymer backbone; and a second monomer having a side chain of formula (III)

wherein Ei , n 5 , n 6 , S 3 , R 4 and R 5 have the same meaning as described above; and; either Xi or Yi is cyano and the other is hydrogen; and Ri , R 2 and R 3 are independently from each other H or -CF 3 or methoxy; and

S 3 is a C 4 alkylene or a C 5 alkylene or a C 6 alkylene or a C 7 alkylene or a C 8 alkylene or a C 9 alkylene or a Ci 0 alkylene or a Cn alkylene or a Ci 2 alkylene; and * denotes the attachment site to the polymer backbone; and wherein the polymer is a polysiloxane.

The present invention relates to a copolymer comprising a first monomer having a side chain of formula (I) or of formula (la) and a second monomer having a side chain of formulae (II) or (III), wherein the molar ratio of the second monomer of formula (II) or of formula (III) in relation to the total amount of monomers of formula (I) or of formula (la) and of formula (II) or (III) is between 0.01 % to 50%, preferably between 0.01 % and 25%, more preferably between 0.01 % and 15%.

In a second embodiment the invention relates to a composition comprising at least one said copolymer as described above and a second polymer or copolymer which is different from the first copolymer. In a preferred second embodiment the invention relates to a composition comprising at least one copolymer as described above and a second polymer or copolymer which is different from the first copolymer and an additive.

The second polymer or copolymer of the second embodiment of the present invention is a polymer or copolymer selected from the group consisting of: polyamic acids, polyamic esters, polyimides, polymerizable liquid crystals, polymerized liquid crystals (LCP), polysiloxanes, polyacrylate, polymethacrylate, polyacrylamide,

polymethacrylamide, polyvinylether, polyvinylester, polyallylether, polyallylester, polystyrene, polyamidimide, polymaleic acid, polyfumaric acid, polyurethane and derivatives thereof, polystyrol, polyester, polyurethane, polyethylene, polypropylen, polyvinylchloride, polytetrafluoroethylen, polycarbonate, polysilane, polymaleinimide, polynorbornene, polyterephthalate, polycyanostilbenes and dendrimere. More preferred second polymer or copolymer of the second embodiment of the present invention is polyamic acid or polyimide. Most preferred is polyamic acid.

The term "diamine" or "diamine compound" is to be understood as designating a chemical structure which has at least two amino groups, i.e. which may also have 3 or more amino groups.

If the second polymer or a copolymer is a diamine, the diamine represents an optionally substituted aliphatic, aromatic or alicyclic diamino group having from 1 to 40 carbon atoms and preferably made from or selected from the following group of structures: aniline, p-phenylenediamine, m-phenylenediamine, benzidine,

diaminofluorene, or their derivatives, with the proviso that compounds listed which do not carry two amino groups are taken as derivatives with at least one additional amino group, and more preferably made from or selected from the following commercially available amino compounds (example of suppliers: Aldrich, ABCR, ACROS, Fluka) which can also be used as comonomers:

4-amino-2,3,5,6-tetrafluorobenzoic acid

4-amino-3,5-diiodobenzoic acid, 3,4-diaminobenzoic acid

4-amino-3-methylbenzoic acid,

4-amino-2-chlorobenzoic acid

4-aminosalicylic acid

4-aminobenzoic acid

4-aminophthalic acid

1 -(4-aminophenyl)ethanol

4-aminobenzyl alcohol

4-amino-3-methoxybenzoic acid

4-aminophenyl ethyl carbinol

4-amino-3-nitrobenzoic acid

4-amino-3,5-dinitrobenzoic acid 4-amino-3,5-dichlorobenzoic acid

4-amino-3-hydroxybenzoic acid

4-aminobenzyl alcohol hydrochloride

4-aminobenzoic acid hydrochloride

pararosaniline base

4-amino-5-chloro-2-methoxybenzoic acid

4-(hexafluoro-2-hydroxyisopropyl)aniline

piperazine-p-amino benzoate

4-amino-3,5-dibromobenzoic acid

isonicotinic acid hydrazide p-aminosalicylate salt

4-amino-3,5-diiodosalicylic acid

4-amino-2-methoxybenzoic acid

2-[2-(4-aminophenyl)-2-hydroxy-1 -(hydroxymethyl)ethyl]isoindoline-1 ,3-dione

4-amino-2-nitrobenzoic acid

2,4-diaminobenzoic acid

p-aminobenzoic acid,

[3,5-3h]-4-amino-2-methoxybenzoic acid

L-(+)-threo-2-amino-1 -(4-aminophenyl)-1 ,3-propanediol

L-(+)-threo-2-(N,N-dimethylamino)-1 -(4-aminophenyl)-1 ,3-propanediol ethyl 2-(4-aminophenyl)-3,3,3-trifluoro-2-hydroxypropanoate

ethyl 2-(4-amino-3-methylphenyl)-3,3,3-trifluoro-2-hydroxypropanoa te ethyl 2-(4-amino-3-methoxyphenyl)-3,3,3-trifluoro-2-hydroxypropano ate

3,4-diaminobenzyl alcohol dihydrochloride

4-aminonaphthalene-1 ,8-dicarboxylic acid

4-amino-3-chloro-5-methylbenzoic acid

4-amino-2,6-dimethylbenzoic acid

4-amino-3-fluorobenzoic acid

4-amino-5-bromo-2-methoxybenzenecarboxylic acid

2,7-diaminofluorene

4,4'-diaminooctafluorobiphenyl

3,3'-diaminobenzidine

3,3',5,5'-tetramethylbenzidine

3,3'-dimethoxybenzidine

o-tolidine 3,3'-dinitrobenzidine

2- nitrobenzidine

3,3'-dihydroxybenzidine

o-tolidine sulfone

benzidine,

3,3'-dichlorobenzidine

2,2',5,5'-tetrachlorobenzidine,

benzidine-3,3'-dicarboxylic acid

4,4'-diamino-1 ,1 '-binaphthyl

4,4'-diaminodiphenyl-3,3'-diglycolic acid

dihydroethidium

o-dianisidine

2,2'-dichloro-5,5'-dimethoxybenzidine

3- methoxybenzidine

3,3'-dichlorobenzidine (diphenyl-d6),

2,7-diamino-9-fluorenone

3,5,3',5'-tetrabromo-biphenyl-4,4'-diamine

2,2'-bis(trifluoromethyl)benzidine

2,2'-dichloro[1 ,1 '-biphenyl]- 4,4'-diamine

3,9-diamino-1 ,1 1 -dimethyl-5,7-dihydro-dibenzo(a,c)cyclohepten-6-one

3,3'-bis(trifluoromethyl)benzidine

dibenzo(1 ,2)dithiine-3,8-diamine

3,3'-tolidine-5-sulfonic acid

3,3'-dichlorobenzidine-d6

tetramethylbenzidine

3,3'-diaminobenzophenone, 3,3'-diaminodiphenylmethane,

4,4-bis-(3-amino-4-hydroxyphenyl)-valeric acid

2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane

2,2-bis(3-amino-4-methylphenyl)hexafluoropropane

tetrabromo methylenedianiline

2,7-diamino-9-fluorenone

2,2-bis(3-aminophenyl)hexafluoropropane

bis-(3-amino-4-chloro-phenyl)-methanone

bis-(3-amino-4-dimethylamino-phenyl)-methanone 3-[3-amino-5-(trifluoromethyl)benzyl]-5-(trifluoromethyl)ani line

1 .5- diaminonaphthalene

or their derivatives, again with the proviso that compounds listed which do not carry two amino groups are taken as derivatives with at least one additional amino group.

Preferred examples of additional other diamines are: ethylenediamine, 1 ,3-propylenediamine, 1 ,4-butylenediamine, 1 ,5-pentylenediamine,

1 .6- hexylenediamine, 1 ,7-heptylenediamine, 1 ,8-octylenediamine,

1 ,9-nonylenediamine, 1 ,10-decylenediamine, 1 ,1 1 -undecylenediamine,

1 ,12-dodecylenediamine, α,α'-diamino-m-xylene, α,α'-diamino-p-xylene, (5-amino- 2,2,4-trimethylcyclopentyl)methylamine, 1 ,2-diaminocyclohexane,

4,4'-diaminodicyclohexylmethane, 1 ,3-bis(methylamino)cyclohexane,

4,9-dioxadodecane-1 ,12-diamine, 3,5-diaminobenzoic acid methyl ester,

3,5-diaminobenzoic acid hexyl ester, 3,5-diaminobenzoic acid dodecyl ester,

3,5-diaminobenzoic acid isopropyl ester, 4,4'-methylenedianiline, 4,4'-ethylenedianiline, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 3,3',5,5'-tetramethylbenzidine,

4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether,

1 ,5-diaminonaphthalene,3,3'-dimethyl-4,4'-diaminobiphenyl,

3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 4,4'-diamino-2,2'-dimethylbibenzyl, bis[4-(4-aminophenoxy)phenyl] sulfone,

1 ,4-bis(4-aminophenoxy)benzene, 1 ,3-bis(4-aminophenoxy)benzene,

1 ,3-bis(3-aminophenoxy)benzene, 2,7-diaminofluorene,

9,9-bis(4-aminophenyl)fluorene, 4,4'-methylenebis(2-chloroaniline),

4,4'-bis(4-aminophenoxy)biphenyl, 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl,

2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4'-(1 ,4-phenyleneisopropylidene)bisaniline,

4,4'-(1 ,3-phenyleneisopropylidene)bisaniline,

2,2-bis[4-(4-aminophenoxy)phenyl]propane,

2,2-bis[3-(4-aminophenoxy)phenyl]hexafluoropropane,

2,2-bis[3-amino-4-methylphenyl]hexafluoropropane,

2,2-bis(4-aminophenyl)hexafluoropropane,

2,2'-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluo ropropane, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, and

4,4'-bis[(4-amino-2-trifluoromethyl)phenoxy]-2,3,5,6,2',3',5 ',6'-octafluorobiphenyl; as well as diamines disclosed in US 6,340,506, WO 00/59966 and WO 01/53384, all of which are explicitely incorporated herein by reference;

The diamine compounds according to the present invention may be prepared using methods that are known to a person skilled in the art. In addition, preferred diamines are the commercially available ones listed below:

Polymers

Poly(3,3',4,4'-benzophenonetetracarboxylic dianhydride-co-4,4'-oxydianiline/1 ,3- phenylenediamine), amic acid solution

Poly(3,3',4,4'-benzophenonetetracarboxylic dianhydride-co-4,4'-oxydianiline/1 ,3- phenylenediamine), amic acid solution

Poly(pyromellitic dianhydride-co-4,4'-oxydianiline), amic acid solution Aromatic diamine:

2,7-diaminofluorene

1 .5- diaminoanthraquinone

2.6- diaminoanthraquinone

pararosaniline hydrochloride

3,6-acridinediamine

4,4'-diaminooctafluorobiphenyl

2,2'-dithiodianiline

3,3',5,5'-tetramethylbenzidine

3,3'-diaminodiphenyl sulfone

4,4'-diamino-2,2'-dimethylbibenzyl

4,4'-diaminodiphenyl ether

4,4'-dithiodianiline

4,4'-diaminodiphenyl sulfone 4,4'-diaminodiphenylmethane

4,4'-ethylenedianiline

3,3'-dimethoxybenzidine

2,2'-dithiobis(1 -naphthylamine)

3,7-diamino-2-methoxyfluorene

3.6- diamino-10-methylacridinium chloride

propidium iodide

o-dianisidine dihydrochloride

2.7- diaminofluorene dihydrochloride

pararosaniline acetate

3, 6-diamino-10-methylacridinium chloride hydrochloride proflavine dihydrochloride

o-tolidine dihydrochloride

3,3',5,5'-tetramethylbenzidine dihydrochloride

3,3'-diaminobenzidine tetrahydrochloride

4,4'-diaminostilbene dihydrochloride

4,4'-diaminodiphenylamine sulfate

proflavine hemisulfate

2,2'-ethylenedianiline diphosphate

1 ,5-diamino-4,8-dihydroxyanthraquinone

o-tolidine

3,3'-diaminobenzophenone

3,3'-diaminodiphenylmethane

3,4'-diaminodiphenylmethane

2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane 4,4'-diamino-1 ,1 '-dianthramide

3,3'-dinitrobenzidine

4,4'-diamino-5,5'-dimethyl-2,2'-biphenyldisulfonic acid 4,4'-diaminostilbene-2,2'-disulfonic acid

3-amino-4-hydroxyphenyl sulfone

4,4-bis-(3-amino-4-hydroxyphenyl)-valeric acid

2,2'-diamino-4,4'-difluorobibenzyl

2-amino-4-chlorophenyl disulfide

3,3'-(decamethylenedioxy)dianiline 3,3'-(pentamethylenedioxy)dianiline

4-(p-aminoanilino)-3-sulfoaniline

4-[3-(4-aminophenoxy)propoxy]aniline

2-nitrobenzidine

benzidine-3-sulfonic acid

4,4'-diaminodiphenyl sulfide

4,4'-diaminobenzanilide

n,n'-bis(3-aminophenylsulfonyl)ethylenediamine

2,2'-biphenyldiamine

3,4'-diaminodip enyl ether

proflavine hemisulphate

phenosafranin

4,4'-diaminobenzophenone

2,2-bis(4-aminophenyl)hexafluoropropane

2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane

2.2- bis(3-amino-4-methylphenyl)hexafluoropropane 3,3'-dihydroxybenzidine

3,3'-diamino-4,4'-dihydroxybiphenyl

4,4'-bis(4-aminophenoxy)biphenyl

2,2-bis[4-(4-aminophenoxy)phenyl]propane

1 .4- bis(4-aminophenoxy)benzene

1 .3- bis(4-aminophenoxy)benzene

bis[4-(4-aminophenoxy)phenyl]sulfone

9,9-bis(4-aminophenyl)fluorene

o-tolidine sulfone

benzidine

3,3'-dichlorobenzidine dihydrochloride

benzidine dihydrochloride

3,6-thioxanthenediamine-10,10-dioxide

4,4'-diamino-2,2'-biphenyldisulfonic acid

4,4'-azodianiline

2.5- bis-(4-aminophenyl)-(1 ,3,4)oxadiazole

3,3'-dimethylnaphthidine

benzidine sulfate 1 .3- bis(3-aminophenoxy)benzene

3,3'-dichlorobenzidine

2,2',5,5'-tetrachlorobenzidine

4,4'-diamino-1 ,1 '-binaphthyl

diamine bordeaux

benzoflavin

chrysaniline

2,2'-thiobis(5-aminobenzenesulfonic acid)

4,4'-methylene-bis(2-chloroaniline)

tetrabromo methylenedianiline

4,4'-diamino-3,3'-dinitrodiphenyl ether

benzidine pyrophosphate

3, 6-diaminothioxanthene-10-dioxide, dihcl

4,4"-diamino-p-terphenyl

1 ,8-diamino-4,5-dihydroxyanthraquinone

bis(p-aminophenoxy)dimethylsilane

bis[4-(3-aminophenoxy)phenyl]sulfone

4,4'-methylenedi-2,6-xylidine

2-aminobenzaldehyde-ethylene-diimine

3-methylbenzidine dihydrochloride

3,3'-diethylbenzidine dihydrochloride

3,6-diaminoacridine hydrochloride

4,4'-diamino-5,5'-dimethyl-2,2'-biphenyl disulfonic acid disodium salt 4,4'-methylenebis(3-chloro-2,6-diethylaniline)

4,4'-methylene-bis-(2,6-diethylaniline)

4,4'-methylenebis-(2,6-diisopropylaniline)

toluylenediamine

3,8-diamino-6-phenylphenanthridine

thionin perchlorate

dihydroethidium

thionin

4.4- diamino benzene sulfonyl anilide

o-dianisidine hcl

2,2'-dichloro-5,5'-dimethoxybenzidine 3-methoxybenzidine

2,2'-(hexamethylenedioxy)dianiline

2,2'-(pentamethylenedioxy)dianiline

2,2'-(ethylenedioxy)dianiline

4-[4-(4-aminophenoxy)butoxy]aniline

2,2'-diamino-4'-methoxy-4-methylbenzanilide

5,5'-dimethyl-2,2'-dinitrobenzidine

n,n'-bis(2-aminophenyl)-1 ,3-propanediamine

3,4'-diaminochalcone

2,3',4,5',6-pentaphenyl-3,4'-biphenyldiamine

2-([1 -(4-(1 -[(2-aminophenyl)thio]-2-nitroethyl)phenyl)-2-nitroethyl]thi o)an ilin

2-((2-[(2-aminophenyl)thio]ethyl)thio)aniline

2- ((4-[(2-aminophenyl)thio]but-2-enyl)thio)aniline

4,4'-diamino-3,3'-dimethyldiphenyl methane

2,2'-diamino-bibenzyl

trimethylene bis(4-aminobenzoate)

fluoresceinamine

benzidines mixture

3- nitro-4,4'-methylenedianiline

4,4-diamino-2,2'-dichlorodiphenyl disulfide

1 ,6-diaminopyrene

1 ,8-diaminopyrene

3,6-diaminocarbazole

4,4'(5')-diamino-[2,4]-dibenzo-18-crown-6,dihydrochloride

4,4'-diaminostilbene-2,2'-disulfonic acid, disodium salt

(r)-(+)-2,2'-diamino-1 ,1 '-binaphthyl

proflavine hemisulfate dihydrate

3,6-diaminoacridine hemisulfate hemihydrate

dimidium bromide monohydrate

o-tolidine dihydrochloride hydrate

3,3',5,5'-tetramethylbenzidine dihydrochloride hydrate

3,3'-diaminobenzidine tetrahydrochloride dihydrate

3,6-[bis(4-amino-3-(sodiumsulphonato)phenlamino)]-2,5-dichlo ro 4-benzoquinone 2,2'-dimethylbenzidine hydrochloride 2,2'-(phenylmethylenebis)bis(4-methylaniline)

3,4'-diaminobiphenyl

2,7-diamino-9-fluorenone

n,n'-bis(2-aminophenyl)oxamide

2-[2-(2-aminophenyl)diaz-1 -enyl]aniline

3,5,3',5'-tetrabromo-biphenyl-4,4'-diamine

n,n'-bis(4-aminophenyl)-1 ,3-bis(aminomethyl)benzene dihydrochloride

4',4"(5")-diaminodibenzo-15-crown-5

2,2'-bis(trifluoromethyl)benzidine

bis(4-amino-2,3-dichlorophenyl)methane

alpha,alpha'-bis(4-aminophenyl)-1 ,4-diisopropylbenzene

2,2-bis(3-aminophenyl)hexafluoropropane

3,10-diamino-6,13-dichlorobenzo[5,6][1 ,4]oxazino[2,3-b]phenoxazine-4,1 1 -dis ulfo n1 -(2-amino-4-methylphenyl)-2-aminobenzamide

n1 -(2-amino-4-chlorophenyl)-2-aminobenzamide

2,2'-dichloro[1 ,1 '-biphenyl]-4,4'-diamine

4,4'(5')-diaminodibenzo-15-crown-5 dihydrochloride

rcl s19,413-1

bis-(4-amino-3-nitro-phenyl)-methanone

bis-(3-amino-4-chloro-phenyl)-methanone

bis-(3-amino-4-dimethylamino-phenyl)-methanone

n,n'-bis-(4-amino-2-chloro-phenyl)-isophthalamide

n,n'-bis-(4-amino-2-chloro-phenyl)-terephthalamide

3,9-diamino-1 ,1 1 -dimethyl-5,7-dihydro-dibenzo(a,c)cyclohepten-6-one

2-aminobenzaldehyde n-[(z)-(2-aminophenyl)methylidene]hydrazone

3,3'-bis(trifluoromethyl)benzidine

dicarboxidine 2 hcl

4,4'-(1 ,3-phenylenediisopropylidene)bisaniline

1 ,4-phenylenebis[[4-(4-aminophenoxy)phenyl]methanone]

2-((5-[(2-aminophenyl)thio]-3,4-dinitro-2-thienyl)thio)an iline

n'1 -(2-aminobenzoyl)-2-aminobenzene-1 -carbohydrazide

2-[4-(5-amino-1 h-benzimidazol-2-yl)phenyl]-1 h-benzimidazol-5-amine

4-[4-(4-aminophenoxy)-2,3,5,6-tetrafluorophenoxy]aniline

3,3'-dinitro-4,4'-diaminodiphenyl sulfone 3,3',4,4'-tetraaminodiphenylsulfone

4-[1 -(4-aminophenyl)-1 -methylethyl]aniline

3.3- diamino diphenyl urea

bis(4-aminophenyl)acetylene

dibenzo(1 ,2)dithiine-3,8-diamine

ethidium homodimer-2

4.4'-bis-(2-aminobenzenesulfonyl)bis-phenolester

neopentyl glycol bis(4-aminophenyl) ether

2,2'-oxydianiline

4,4'-diaminodiphenylamine-2,2-disulphonic acid

4.4- diamino diphenyl urea

3,3'-tolidine-5-sulfonic acid

n1 -(3-[(2-aminobenzoyl)amino]propyl)-2-aminobenzamide

2-((6-[(2-aminophenyl)sulfanyl]-5-nitro-2-pyridyl)sulfany l)aniline

2-((6-amino-1 ,3-benzothiazol-2-yl)dithio)-1 ,3-benzothiazol-6-ylamine tetramethylbenzidine

2-([6-[(2-aminophenyl)sulfanyl]-3,5-di(trifluoromethyl)-2-py ridyl]sulfanyl) anil 3,6-diaminothioxanthene-10-dioxide dihydrochloride

m-tolidine dihydrochloride hydrate

2-amino-n-[2-amino-4-(trifluoromethyl)phenyl]-5-methylben zamide

2-([2-[(2-aminophenyl)thio]-6-nitro-4-(trifluoromethyl)pheny l]thio)aniline

2- [(3-([(2-aminophenyl)thio]methyl)-2,4,6-trimethylbenzyl)thio ]aniline

3- [3-amino-5-(trifluoromethyl)benzyl]-5-(trifluoromethyl)anili ne

2- ((5-[(2-aminophenyl)thio]-4-chloro-2-nitrophenyl)thio)anilin e

4-(1 -(4-aminophenyl)-2-[4-(dimethylamino)phenyl]vinyl)aniline

1 .5- bis(4-aminophenoxy)pentane

2,3'-dichlorobenzidine dihydrochloride

3,3'-diamono-4,4'-dichlorodiphenyl sulfone

3- (bis-(4-amino-phenyl)-methyl)-2,3-dihydro-isoindol-1 -one

4,4-diamino diphenyl-2-sulphonic acid

4,4'-diamino-diphenylene-cycylohexane

4,5'-diamino-(1 ,1 ')bianthracenyl-9,10,9',10'-tetraone

Alicyclic diamines: 4,4'-methylenebis(cyclohexylamine)

4,4'-methylenebis(2-methylcyclohexylamine) Aliphatic diamines:

1 ,8-diamino-p-menthane

4,4'-methylenebis(cyclohexylamine)

d-cystine

l-cystine dimethyl ester dihydrochloride

neamine

bis(2-aminopropyl)amine

(h-cys-beta-na)2 2 hcl

l-cystine dibenzyl ester ditosylate

1 .4-diaminocyclohexane

(h-cys-pna)2

dl-2-aminopropionic anhydride

l-cystine(di-b-naphthylamide)hydrochloride

l-cystine-bis-p-nitroanilide dihydrobromide

l-cystine diethyl ester dihydrochloride

trans-1 ,4-cyclohexanediamine

4,4'-methylenebis(2-methylcyclohexylamine)

l-leucinethiol, oxidized dihydrochloride

1 ,3-diaminoadamantane dihydrochloride

l-leucinethiol disulfide 2 hcl

l-cystine disodium salt, monohydrate

l-homocystine methylester hydrochloride

1 ,3-adamantanediamine

tetracyclo[8.2.1 .1 (8, 1 1 ).0(2,7)]tetradeca-2,4,6-triene- 10,1 1 -diamine

tricyclo[3.3.1 .0(3,7)]nonane-3,7-diamine

From the class of commercially available diamines preferred are the below listed ones:

Alicyclic diamines: 4,4'-methylenebis(cyclohexylamine)

4,4'-methylenebis(2-methylcyclohexylamine)

Aliphatic diamines

4,4'-methylenebis(cyclohexylamine)

1 .4-diaminocyclohexane

trans-1 ,4-cyclohexanediamine

4,4'-methylenebis(2-methylcyclohexylamine)

1 ,3-adamantanediamine

Aromatic diamines

2,7-diaminofluorene

2,6-diaminoanthraquinone

4,4'-diaminooctafluorobiphenyl

4,4'-diaminodiphenyl ether

4,4'-dithiodianiline

4,4'-diaminodiphenylmethane

4,4'-ethylenedianiline

3,3'-dimethoxybenzidine

o-tolidine

3,3'-diaminobenzophenone

3,3'-diaminodiphenylmethane

3,4'-diaminodiphenylmethane

2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane

4-[3-(4-aminophenoxy)propoxy]aniline

4,4'-diaminodiphenyl sulfide

4,4'-diaminobenzophenone

2,2-bis(4-aminophenyl)hexafluoropropane

4,4'-bis(4-aminophenoxy)biphenyl

2.2- bis[4-(4-aminophenoxy)phenyl]propane

1 ,4-bis(4-aminophenoxy)benzene

1 .3- bis(4-aminophenoxy)benzene

bis[4-(4-aminophenoxy)phenyl]sulfone

9,9-bis(4-aminophenyl)fluorene

benzidine 4,4'-azodianiline

1 .3- bis(3-aminophenoxy)benzene

4,4'-diamino-1 ,1 '-binaphthyl

4,4"-diamino-p-terphenyl

bis(p-aminophenoxy)dimethylsilane

4-[4-(4-aminophenoxy)butoxy]aniline

3,4'-diaminochalcone

trimethylene bis(4-aminobenzoate)

3,4'-diaminobiphenyl

2,7-diamino-9-fluorenone

4',4"(5")-diaminodibenzo-15-crown-5

2,2'-bis(trifluoromethyl)benzidine

alpha,alpha'-bis(4-aminophenyl)-1 ,4-diisopropylbenzene

3,3'-bis(trifluoromethyl)benzidine

4,4'-(1 ,3-phenylenediisopropylidene)bisaniline

1 .4- phenylenebis[[4-(4-aminophenoxy)phenyl]methanone]

4-[4-(4-aminophenoxy)-2,3,5,6-tetrafluorophenoxy]aniline

4-[1 -(4-aminophenyl)-1 -methylethyl]aniline

neopentyl glycol bis(4-aminophenyl) ether

4,4-diamino diphenyl or

1 .5- bis(4-aminophenoxy)pentane

From the class of commercially available diamines (L) more preferred are the below listed ones:

Aromatic diamines:

2,7-diaminofluorene

4,4'-diaminooctafluorobiphenyl

4,4'-diaminodiphenyl ether

4,4'-diaminodiphenylmethane

4,4'-ethylenedianiline

3,3'-diaminobenzophenone

4-[3-(4-aminophenoxy)propoxy]aniline 4,4'-diaminodiphenyl sulfide

4,4'-diaminobenzophenone

2.2- bis(4-aminophenyl)hexafluoropropane

4,4'-bis(4-aminophenoxy)biphenyl

2,2-bis[4-(4-aminophenoxy)phenyl]propane

1 .4- bis(4-aminophenoxy)benzene

1 .3- bis(4-aminophenoxy)benzene

9,9-bis(4-aminophenyl)fluorene

benzidine

bis(p-aminophenoxy)dimethylsilane

4-[4-(4-aminophenoxy)butoxy]aniline

3,4'-diaminochalcone

trimethylene bis(4-aminobenzoate)

3,4'-diaminobiphenyl

2,7-diamino-9-fluorenone

4',4"(5")-diaminodibenzo-15-crown-5

4-[4-(4-aminophenoxy)-2,3,5,6-tetrafluorophenoxy]aniline

4-[1 -(4-aminophenyl)-1 -methylethyl]aniline

1 .5- bis(4-aminophenoxy)pentane

Aliphatic diamines:

4,4'-methylenebis(cyclohexylamine)

1 .4- diaminocyclohexane

Alicyclic diamines

4,4'-methylenebis(cyclohexylamine)

Preferably, the further polymer, homo- or copolymer or oligomer comprises at least a diamine as one of the basic building block, and a tetracarboxylic acid anhydride, preferably a tetracarboxylic acid anhydride of formula (VII).

Preferably, the substituted or unsubstituted, preferably substituted within polar group or unsubstituted, tetracarboxylic acid anhydride is of formula (VII): wherein:

T represents a tetravalent organic radical.

The tetravalent organic radical T is preferably derived from an aliphatic, alicyclic or aromatic tetracarboxylic acid dianhydride. The tetravalent organic radical T is preferably derived from an aliphatic, alicyclic or aromatic tetracarboxylic acid dianhydride.

Preferred examples of aliphatic or alicyclic tetracarboxylic acid dianhydrides are: 1 ,1 ,4,4-butanetetracarboxylic acid dianhydride, ethylenemaleic acid dianhydride,

1 .2.3.4- cyclobutanetetracarboxylic acid dianhydride, 1 ,2, 3,4-cyclopentanetetracarboxyli c acid dianhydride; 2,3,5-tricarboxycyclopentylacetic acid dianhydride (with the term "2,3,5-tricarboxycyclopentylacetic acid dianhydride" all isomers of this compound are incorporated especially the exo and/or endo body), 2,3,5-tricarboxycyclopentylacetic- 1 ,2:3,4-dianhydride is accessible for example by processes as described in JP59-

190945, JP60-13740 and JP58-109479, respectively DE 1078120 and JP58-109479, or GB 872,355, and JP04458299, which processes are herewith incorporated by reference; tetrahydro-4,8-methanofuro[3,4-d]oxepine-1 ,3,5,7-tetrone, 3-(carboxymethyl)-1 ,2,4- cyclopentanetricarboxylic acid 1 ,4:2,3-dianhydride,

hexahydrofuro[3',4':4,5]cyclopenta[1 ,2-c]pyran-1 ,3,4,6-tetrone, 3,5,6-tricarboxy- norbornylacetic acid dianhydride,

2.3.4.5- tetrahydrofurantetracarboxylic acid dianhydride, rel-[1 S,5R,6R]-3-oxabicyclo[3.2. 1 ]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran2',5'-dione), 4-(2,5-dioxotetrahydrofuran- -3-yl)tetrahydronaphthalene-1 ,2-dicarboxylicacid dianhydride, 5-(2,5-dioxotetrahydro- furan-3-yl)-3-methyl-3-cyclohexene-1 ,2-dicarboxylic-acid dianhydride,

bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride,

bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic acid dianhydride,

1 ,8-dimethylbicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, pyromellitic acid dianhydride,3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 4,4'-oxydiphthalic acid dianhydride,

3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 1 ,3-dimethyl-1 ,2,3,4- cyclobutanetetracarboxylicacid dianhydride, 1 ,3-difluoro-1 ,2,3,4- cyclobutanetetracarboxylicacid dianhydride, 1 ,3-dichloro-1 ,2,3,4- cyclobutanetetracarboxylicacid dianhydride,

1 ,2,3-trimethyl-1 ,2,3,4-cyclobutanetetracarboxylicacid dianhydride, 1 ,2,3,4-tetramethyl- 1 ,2,3,4-cyclobutanetetracarboxylicacid dianhydride, 1 -methyl-1 ,2,3,4- cyclobutanetetracarboxylicacid dianhydride,

1 ,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2, 3, 6,7-naphthalenetetracarboxylic acid dianhydride, 3,3',4,4'-dimethyldiphenylsilanetetracarboxylic acid dianhydride, 3,3',4,4'-tetraphenylsilanetetracarboxylic acid dianhydride, 1 ,2,3,4-furantetracarboxylic a cid di-anhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride,

4,4'-bis(3,4-dicarboxyphenoxy)-diphenyl sulfone dianhydride,

4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride,

3,3',4,4'-biphenyltetracarboxylic acid dianhydride,

ethylene glycol bis(trimellitic acid) dianhydride,4,4'-(1 ,4-phenylene)bis(phthalic acid) dia nhydride, 4,4'-(1 ,3-phenylene)bis(phthalic acid) dianhydride,

4,4'-(hexafluoroisopropylidene)diphthalic acid dianhydride, 4-te/?-butyl-6-(2,5- dioxotetrahydro-3-furanyl)-2-benzofuran-1 ,3-dione, 5-(2,5-dioxotetrahydro-3-furanyl)- 3a,4,5,9b-tetrahydronaphtho[1 ,2-c]furan-1 ,3-dione, 5-(2,5-dioxotetrahydro-3-furanyl)-5- methyl-3a,4,5,9b-tetrahydronaphtho[1 ,2-c]furan-1 ,3-dione, 5-(2,5-dioxotetrahydro-3- furanyl)-6-methylhexahydro-2-benzofuran-1 ,3-dione, 5-(2,5-dioxotetrahydro-3-furanyl)- 7-methyl-3a,4,5,7a-tetrahydro-2-benzofuran-1 ,3-dione, 6-(2,5-dioxotetrahydro-3- furanyl)-4-methylhexahydro-2-benzofuran-1 ,3-dione, 9-isopropyloctahydro-4,8- ethenofuro[3',4':3,4]cyclobuta[1 ,2-/][2]benzofuran-1 ,3,5,7-tetrone, 1 ,2,5,6- cyclooctanetetracarboxylic acid dianhydride, octahydro-4,8- ethenofuro[3',4':3,4]cyclobuta[1 ,2-f][2]benzofuran-1 ,3,5,7-tetrone,

octahydrofuro[3',4':3,4]cyclobuta[1 ,2-/][2]benzofuran-1 ,3,5,7-tetrone, tetrahydro-3,3'- bifuran-2,2',5,5'-tetrone, 4,4'-oxydi(1 ,4-phenylene)bis(phthalic acid) dianhydride, and 4,4'-methylenedi(1 ,4-phenylene)bis(phthalic acid) dianhydride.

Preferred examples of aromatic tetracarboxylic acid dianhydrides are: pyromellitic acid dianhydride,

3,3',4,4'-benzophenonetetracarboxylic acid dianhydride,

4,4'-oxydiphthalic acid dianhydride,

3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride,

1 ,4,5,8-naphthalenetetracarboxylic acid dianhydride,

2,3,6,7-naphthalenetetracarboxylic acid dianhydride,

3,3',4,4'-dimethyldiphenylsilanetetracarboxylic acid dianhydride,

3,3',4,4'-tetraphenylsilanetetracarboxylic acid dianhydride,

1 ,2,3,4-furantetracarboxylic acid dianhydride,

4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride,

4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfone dianhydride,

4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride,

3,3',4,4'-biphenyltetracarboxylic acid dianhydride,

ethylene glycol bis(trimellitic acid) dianhydride,

4,4'-(1 ,4-phenylene)bis(phthalic acid) dianhydride,

4,4'-(1 ,3-phenylene)bis(phthalic acid) dianhydride,

4,4'-(hexafluoroisopropylidene)diphthalic acid dianhydride,

4,4'-oxydi(1 ,4-phenylene)bis(phthalic acid) dianhydride,

4,4'-methylenedi(1 ,4-phenylene)bis(phthalic acid) dianhydride,

4-tert-butyl-6-(2,5-dioxotetrahydro-3-furanyl)-2-benzofur an-1 ,3-dione,

and the like.

More preferably the tetracarboxylic acid dianhydrides used to form the tetravalent organic radical T are selected from:

1 ,2,3,4-cyclobutanetetracarboxylic acid dianhydride,

1 ,2,3,4-cyclopentanetetracarboxylic acid dianhydride,

2,3,5-tricarboxycyclopentylacetic acid dianhydride,

tetrahydro-4,8-methanofuro[3,4-d]oxepine-1 ,3,5,7-tetrone, 3- (carboxymethyl)-1 ,2,4-cyclopentanetricarboxylic acid 1 ,4:2,3-dianhydride,

hexahydrofuro[3',4':4,5]cyclopenta[1 ,2-c]pyran-1 ,3,4,6-tetrone,

5-(2,5-dioxotetrahydrofuran-3-yl)-3-methyl-3-cyclohexene- 1 ,2-dicarboxylic acid dianhydride,

pyromellitic acid dianhydride,

4- (2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1 ,2-dicarboxylic acid dianhydride,

5- (2,5-dioxotetrahydro-3-furanyl)-5-methyl-3a,4,5,9b-tetrahydr onaphtho[1 ,2-c]furan-1 ,3- dione,

5-(2,5-dioxotetrahydro-3-furanyl)-3a,4,5,9b-tetrahydronap htho[1 ,2-c]furan-1 ,3-dione, 5-(2,5-dioxotetrahydro-3-furanyl)-7-methyl-3a,4,5,7a-tetrahy dro-2-benzofuran-1 ,3- dione,

4-tert-butyl-6-(2,5-dioxotetrahydro-3-furanyl)-2-benzofuran- 1 ,3-dione,

4,4'-(hexafluorneoisopropylidene)diphthalic acid dianhydride and

bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride.

In the context of the present invention the term "polyimide" has the meaning of partially or completely imidisated polyamic acid or polyamic ester. In analogy, the term

"imidisation" has in the context of the present invention the meaning of partially or complete imidisation.

The second embodiment of the present invention relates more particularly to a composition wherein the second polymer or copolymer is 100% imidised, or has an imidisation degree in the range of 1 to 99%, preferably 5 to 50%, more preferably 10 to 40% by weight.

In the context of the second embodiment of the present invention, the composition may comprise a siloxane copolymer as described above, a second polymer or copolymer which is different from the first one and at least one additional polymer or copolymer which is different from the first and from the second polymer or copolymer of the composition.

In the second preferred embodiment the invention relates to a composition comprising at least one siloxane copolymer as described above and a second polymer or copolymer which is different from the first one and an additive and wherein the additive is an additive which is known by the person skilled in the art.

The additive is selected from the group consisting of: nucleating agents, clarifying agents, antistatics, antioxidants, slip agents, silica, talc, stabilizers, UV stabilizers, lubricants, coupling agents, antimicrobial agents, crosslinking agents, agents enhancing the crosslinking of the polymer backbone, as for example an acid generator, a base generator or a tetra-alkoxy-siloxane as tetraethoxysilan, or a siloxane monomer such as trialkoxysiloxane; surfactants, photo-active agents, photo-sensitizers, photo generators.

Additives such as silane-containing compounds and epoxy-containing crosslinking agents may be added. Suitable silane-containing additives are described in Plast. Eng. 36 (1996),

(Polyimides, fundamentals and applications), Marcel Dekker, Inc.

Suitable epoxy-containing cross-linking additives include

4,4'-methylene-bis-(N,N-diglycidylaniline), trimethylolpropane triglycidyl ether, benzene-1 ,2,4,5-tetracarboxylic acid 1 ,2,4,5-N,N'-diglycidyldiimide, polyethylene glycol diglycidyl ether, Ν,Ν-diglycidylcyclohexylamine and the like.

Suitable photo-active agents include 2,2-dimethoxyphenylethanone, a mixture of diphenylmethanone and Ν,Ν-dimethylbenzenamine or ethyl 4-(dimethylamino)- benzoate, xanthone, thioxanthone, 1 -Hydroxy-cyclohexyl-phenyl-ketone, 2-Benzyl-2- dimethylamino-1 -(4-morpholinophenyl)-butanone-1 , lrgacure ® 500 (1 :1 mixture by weight of 1 -Hydroxy-cyclohexyl-phenyl-ketone and benzophenone) and 2,2-Dimethoxy- 1 ,2-diphenylethan-1 -one, Michler's ketone, triaryl sulfonium salt and the like. The compositions according to the second embodiment of the invention, preferably blends, comprises a copolymer according to definition and preferences of the invention, a second polymer or copolymer which is different from the first one, and optionally further comprise an organic solvent. In the context of the present invention, organic solvent means any solvent commonly known in the art. More specifically the organic solvent is selected from the group consisting of: hydrocarbon, ketone, ester, ether and alcohol.

Examples of the above hydrocarbon include toluene and xylene; examples of the above ketone include methyl ethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, diethyl ketone and cyclohexanone; examples of the above ester include ethyl acetate, n-butyl acetate, i-amyl acetate, propylene glycol monomethyl ether acetate, 3- methoxybutyl acetate and ethyl lactate; examples of the above ether include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, tetrahydrofuran and dioxane; and examples of the above alcohol include 1 -hexanol, 4-methyl-2-pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol mono-n-propyl ether. Out of these, water-insoluble organic solvents are preferred.

Further examples of organic solvents are chlorobenzene, pyrrolidone solvents, preferably, N-methyl-2- pyrrolidone, N-ethyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone; imidazolidinone, dimethylsulfoxide, dimethylformamide, toluene, chloroform, organic ester, such as acetyl acetic ester or butyl acetic ester, pentyl acetic ester, hexyl acetic ester; further Y-butyrolactone, methyl cellosolve, butyl cellosolve, butyl carbitol, tetrahydrofuran, ditehylene glycol diethylether, dipentylether dipropylene glycol dimethylether, diisobutyl ketone momoethylene glycol dimethyl ether, etc. These solvents can be used alone or in mixtures thereof. The amount of the organic solvent is preferably 0.5 to 150000 parts by weight, preferably 100 to 100000 parts by weight, more preferably 150 to 25000 parts by weight based on 100 parts by weight of the total of all the copolymer compounds.

These organic solvents may be used alone or in combination of two or more.

The third object of the present invention is to provide an orientation layer comprising one said copolymer.

In the context of the present invention the wording "polymer or oligomer layer" has the meaning of "copolymer layer or oligomer layer".

In the context of the present invention the wording "orientation layer" has the same meaning as "orientation film".

The copolymers according to the invention may be used in form of orientation layers alone or in combination with other polymers, copolymers, oligomers, monomers, photoactive polymers, photo-active oligomers and/or photo-active monomers, depending upon the application to which the polymer or oligomer layer is to be added. Therefore it is understood that by varying the composition of the copolymer layer it is possible to control specific and desired properties, such as a good surface wetting, a high voltage holding ratio, a specific anchoring energy, etc.

The fourth object of the present invention is to provide a method for the preparation of the orientation layer comprising said copolymer by exposure of the copolymer with aligning light and to orientation layers obtained by such method.

The copolymer comprises in its side-chains at least one photo- reactive group. Preferably, the photo-reactive group of the side chains reacts by exposure to aligning light.

In the context of the present invention the term "photoreactive groups" has the meaning of groups which are able to react by interaction with light, preferably aligning light.

The treatment with aligning light may be conducted in a single step or in several separate steps. In a preferred embodiment of the invention the treatment with aligning light is conducted in a single step. In the context of the present invention photoreactive group has preferably the meaning of a dimerizable, isomerizable, polymerizable and/or cross-linkable group.

In the context of the present invention, aligning light, preferably polarized light is light of wavelengths, such that it can initiate photoalignment. Preferably, the wavelengths are in the UV-A, UVB and/or UV/C-range, or in the visible range. It depends on the photoalignment compound, which wavelengths are appropriate. Preferably, the photo- reactive groups are sensitive to visible and/or UV light. A further embodiment of the invention concerns the generation of aligning light by laser light.

The instant direction of the aligning light may be normal to the substrate or at any oblique angle.

More preferably, aligning light is at least partially linearly polarized, elliptically polarized, such as for example circulary polarized, or non-polarized; most preferably at least circulary or partially linearly polarized light, or non-polarized light exposed obliquely. Especially, most preferred aligning light denotes substantially polarised light, especially linearly polarised light; or aligning light denotes non-polarised light, which is applied by an oblique irradiation.

A more preferred embodiment of the invention relates to a method for the preparation of the orientation layer by exposure of the copolymer with polarised light, especially linearly polarised light, or by oblique radiation with non-polarised light. Further preferred are copolymers of the present invention, wherein the copolymer is a copolymer gel or a copolymer network; and/or wherein the copolymer has an intrinsic viscosity in the range of 0.01 to 10 dIJg, preferably in the range of 0.02 to 5 dIJg; and/or

- wherein the copolymer has a molecular weight of 1 to 6Ό00Ό00, 1 Ό00 to

6Ό00Ό00, 2Ό00 to 1 Ό00Ό00, 2Ό00 to 500Ό00, more preferably 5Ό00 to 250Ό00.

wherein the copolymer contains from 2 to 20000 repeating units, especially from 4 to 2000 repeating units, more especially 6 to 1000 repeating units; and/or - wherein the copolymer or oligomer is in the form of a statistical copolymer.

A further preferred embodiment of the present invention relates to copolymers having an intrinsic viscosity preferably in the range of 0.01 to 10 dIJg, more preferably in the range of 0.01 to 1 dL/g. Herein, the intrinsic viscosity (rjjnh = In Tlrel/C) is determined by measuring a solution containing a copolymers in a concentration of 0.5 g/100 ml solution for the evaluation of its viscosity at 30 'C using N-methyl-2-pyrrolidone as solvent. In addition, a preferred embodiment of the present invention relates to copolymers containing from 2 to 20000 repeating units, especially from 4 to 2000 repeating units, more especially 6 to 1000 repeating units.

Copolymer layers may readily be prepared from the copolymers of the present invention and a further embodiment of the invention relates to a copolymer layer comprising a copolymer according to the present invention, which is preferably prepared by treatment with aligning light.

Preferably, the invention relates to a copolymer layer comprising a copolymer according to the present invention or as prepared according to the present invention.

The copolymer layer is preferably prepared by applying one or more copolymers or compositions according to the invention to a support and, after imidisation or without imidisation, irradiating the copolymer or copolymer mixture with aligning light. Aligning light has the above given meaning and preferences.

The term "support" as used in the context of the present invention is preferably transparent or not-transparent, preferably glass or plastic substrates, polymer films, such as polyethyleneterephthalat (PET), tri-acetyl cellulose (TAC), polypropylen, optionally coated with indium tin oxide (ITO), however not limited to them.

In general a composition comprising the copolymers of the invention is applied by general coating and printing methods known in the art, such as spin-coating, meniscus- coating, wire-coating, slot-coating, offset-printing, flexo-printing, gravure-printing, ink jet printing may be used. Coating methods are for example spin coating, air doctor coating, blade coating, knife coating, reverse-roll coating, transfer roll coating, gravure roll coating, kiss roll coating, cast coating, spray coating, slot-orifice coating, calendar coating, electrodepositing coating, dip coating or die coating. In general, transparent support such as glass or plastic, which are not flexble or flexible substrates, optionally coated with indium tin oxide (ITO) or Pedot: PSS (Poly(3,4- ethylenedioxythiophene) poly(styrenesulfonate) or graphene based materials are used. Flexible substrates are used for flexible LCDs.

Printing methods are for example relief printing such as flexographic printing, ink jet printing, intaglio printing such as direct gravure printing or offset gravure printing, lithographic printing such as offset printing, or stencil printing such as screen printing. A further preferred embodiment of the present invention relates to orientation layers which are unstructured or structured.

In addition the present invention relates to a process for the preparation of structured copolymer layers comprising varying the direction of orientation and/or the tilt angle within the copolymer layer. This varying of the direction of orientation and/or the tilt angle can for example be conducted by controlling the direction of the irradiation of the aligning light. It is understood that by selectively irradiating specific regions of the polymer, copolymer or oligomer layer very specific regions of the layer can be aligned. In this way, layers with a defined tilt angle can be provided. The irradiation time is dependent upon the output of the individual lamps and can vary from a few seconds to several hours. The photo-reaction can also be carried out, however, by irradiation of the homogeneous layer using filters that, for example, allow only the radiation suitable for the reaction to pass through. Further preferred is a process for the preparation of a copolymer layer; for the preparation of planar multi-domain alignment of a copolymer layer; and/or for the preparation of a copolymer layer having a tilt angle within the given meaning and preferences of the invention. A further preferred embodiment of the invention relates to an orientation layer comprising one or more copolymers according to the invention.

In the context of the present invention orientation layer has the same meaning and preferences as alignment layer, copolymer layer and is preferably a photo alignment layer.

In the context of the present invention, the orientation layer is used for the planar alignment (in plane switching) of liquid crystals or for the vertical alignment of liquid crystals.

In a more preferred embodiment the invention relates to an orientation layer according to the invention and its use for the planar alignment of liquid crystals. In the context of the present invention the wording "alignment of liquid crystals" means that the liquid crystals have a tilt angle.

The term tilt angle as used in the context of the present invention is the angle between the liquid crystal director and the surface of the alignment layer. The liquid crystal director shall mean the average direction of the long axes of the liquid crystal molecules. In the context of the present invention, planar alignment shall mean that the tilt angle is less than 30°, preferably 0 to 30 °.

In preferred embodiments the tilt angle of the liquid crystals, induced by the photo- alignment layer is less than 10°, preferably 0 to 10 °. In more preferred embodiments the tilt angle is less than 5°, preferably 0 to 5°, and in most preferred embodiments the tilt angle is less than 1 °, preferably 0 to 1 °, even more preferably from 0° to 0.5°.

Preferred are tilt angles of less than 0.2° or 0.1 °. In the context of the present invention, vertical alignment shall mean that the tilt angle is more than 70 °, 75°, preferably more than 80 °, 85°, more preferably between 85° and 90°, even more preferably between 86° and 87° or between 87° and 88° or between 88 0 and 89 0 or between 89 0 and 90 0 . The fifth embodiment of the present invention is the use of said orientation layer, for the alignment, especially the planar alignment, of

-a) liquid crystal composition comprising one or more polymerizable liquid crystal monomers, or comprising one or more liquid crystal polymers or oligomers, which are the polymerized form of said polymerizable liquid crystal monomers, and/or -b) liquid crystal compositions comprising one or more polymerizable liquid crystal monomers, or comprising one or more liquid crystal polymers or oligomers, which are the polymerized form of said polymerizable liquid crystal monomers, said liquid crystal compositions being sandwiched between a pair of said orientation layers.

Examples of liquid crystal polymers (LCP) are described in US2012/1 14907 A1 , which is herewith incorporated by reference.

A LCP material as used within the context of this application shall meand a liquid crystal material, which comprises liquid crystal monomers and/or liquid crystal dimers and/or liquid crystal polymers and/or crosslinked liquid crystals. In case the liquid crystal material comprises liquid crystal monomers, such monomers may be

polymerized, typically after anisotropy has been created in the LCP material due to contact with a photo-aligning material. Polymerization may be initiated by thermal treatment of by exposure to actinic light, which preferably comprises UV-light. A LCP- material may consiste of a single type of liquid crystal compound, but may also be a composition of different polymerizable and/or non-polymerizable compounds, wherein not all of the compounds have to be liquid crystal compounds. Further, an LCP material may contain additives, for example, a photo-initiator or isotropic or anisotropic fluorescent and/or non-fluorescent dyes.

Further, the present invention relates preferably to the use of an orientation layer according to the invention for the induction of planar alignment of adjacent liquid crystalline layers, in particular for operating a cell wherein planar orientation is provided, such in IPS, such as IPS modes like S-IPS (Super IPS), AS-IPS (Advanced super IPS), E-IPS (Enhanced IPS), H-IPS (Horizontal IPS), UH-IPS, S-IPS II, e-IPS, p- IPS (performance IPS), PLS technology (plane to line switching), PS-IPS (polymer stabilized IPS), Field induced photoreactive alignment IPS FFS (fringe field switching), TN (twisted nematic), STN (supertwisted nematic).

Liquid crystal compositions of the present invention comprise a polymerizable monomer, or a polymer or oligomer, which is the polymerized form of said

polymerizable monomer. The polymerizable monomer or the polymer or oligomer, is bifunctional and/or has a rigid core (e.g. benzene). Further preferred is a polymerizable monomer, or a polymer or oligomer, which have one or more ring or condensed ring structures and functional groups bonded directly to the ring or condensed ring structure. More preferred liquid crystals have a monomer of formula (VIII) P S a -Ab iZb Ab^ g - S b -P 2 (VIII) wherein

Pi and P 2 are functional groups and are independently selected from acrylate, methacrylate, halogenacrylate, such as fluoroacrylate, chloroacrylate; oxetanyl, maleinimidyl, allyl, allyloxy, vinyl, vinyloxy and epoxy groups, S a and S b are independently from each other a single bond or a spacer unit, which is preferably a straight-chain or branched, substituted or unsubstituted Ci-C 24 alkylen, in which one or more, preferably non-adjacent, C-atom, CH- or CH 2 -, group may be replaced by a linking group within the above given meaning and preferences, and, preferably replaced by is a single bond, -0-, -O(CO), -S-, -(CO)O- or Ν > , -NR 2 -, wherein the substituent is preferably at least one CrC 6 alkyl, preferably methyl and wherein R 2 is a lower alkyl.

Abi and Ab 2 are ring structures and independently selected from unsubstituted or substituted carbocyclic or heterocyclic aromatic or alicyclic group with the meaning and preferences given in the present invention, especially preferred are 1 ,4-phenylene naphthalene- 2,6-diyl, terphenyl, quarterphenyl, phenanthrene groups,

Zbi is selected from -0-, -CO-, -CH(OH)-, -CH 2 (CO)-, -OCH 2 -, -CH 2 0-, -0-CH 2 - 0-, -C00-, -0C0-, -(CO)-(CO)-, -OCF 2 -, -CF 2 0-, -CF 2 -, -CON(C C 16 alkyl)-, -(C C 16 alkyl)NCO-, -CONH-, -NHCO-, -HNOCO-, -OCONH-, -NHCONH-, -OCOO- , -CO-S-, -S-CO- ,- CSS, -S00-, -OSO-

,-SOS-, -SO-, -CH 2 (SO)-, -S0 2 -, -CH=CH-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH-, - CH=N-, -C(CH 3 )=N-, -N=N-, or a single bond; or a cyclic, straight-chain or branched, substituted or unsubstituted d-C 24 alkylen, wherein one or more C-atom, CH- or CH 2 -group may independently from each other be replaced by a linking group; preferably, Zbi is -0-, -CO-, -COO-, -OCO-, -OCOO-, -OCF 2 -, -CF 2 0-,

-CON(CH 3 )-, -(CH 3 )NCO-, -CONH-, -NHCO-, -CO-S-, -S-CO-, - CSS, -SOO-, -OSO-,

-CSS-, -SOO-, -OSO-, -CH 2 (S0 2 )-, -CH 2 -CH 2 -, -OCH 2 -, -CH 2 0-

, -CH=CH-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH-, or a single bond; more preferably Zb ! is -COO-, -OCO-, -OCOO-, -OCF 2 -, -CF 2 0-, -CON(CH 3 )-, -(CH 3 )NCO-, -CONH-, -NHCO-, -CO-S-, -S-CO-, -CS-S-, -SOO-, -OSO, especially -COO-, -OCO-, -OCF 2 -, -CF 2 0-, -CON(CH 3 )-, -(CH 3 )NCO-, -CONH-, -NHCO- or a single bond; most preferred Zbi is a single bond, -COO- or -OCO-; and g is an integer of 1 , 2, or 3.

In formula (VI), and P 2 are preferably acrylate or methacrylate groups, S a and S b are a single bond Zbi is preferably a single bond, and g is preferably 0 or 1 .

Most preferred the liquid crystal is a compound represented by any one of the formulae

wherein and P 2 are independently from each other an acrylate, methacrylate, oxetane, maleinimide, allyl, allyloxy, vinyl, vinylamide, vinyloxy and epoxy group, epoxy derivatives, butoxy and butoxy derivatives,

B is a single bond, -CO-C(Ci-C 6 alkoxy) 2 -, -COO-, -OCO-, Yi , Y 2 , Y 3 , Y 4 , Y5, Ye of the liquid crystal are independently from each other hydrogen, a straight-chain or branched d-Ci 6 alkyl group, which is unsubstituted or substituted by fluorine, di-(CrCi 6 alkyl)amino, CrCi 5 alkyloxy, nitro, nitrile and/or chlorine; and wherein one or more C-atom, CH- or CH 2 - group may independently from each other be replaced by a linking group; halogen or nitrile; preferred substituents are CrC 6 alkyl group, especially methyl or ethyl, CrC 6 alkoxy group, especially methoxy or ethoxy, chlorine, fluorine, or nitrile, more preferably methoxy, chlorine, fluorine, or CN and most preferably methoxy, chlorine or fluorine; further, if the aromatic group is substituted, then it is preferably substituted once or twice; Si , S 2 , of the liquid crystal are independently from each other a single bond or a spacer unit, which is preferably a straight-chain or branched, substituted or unsubstituted C C 24 alkylen, in which one or more, preferably non-adjacent, C-atom, CH- or CH 2 -, group may be replaced by a linking group within the above given meaning and preferences, and, preferably replaced by is a single bond, -0-, -O(CO), -S-, -(CO)O- or ^ , - NR 2 -, wherein the substituent is preferably at least one CrC 6 alkyl, preferably methyl and wherein R 2 is a lower.

In formula (IX), Pi and P 2 are preferably acrylate or methacrylate groups, Si and S 2 are a single bond Ζ is preferably a single bond, and n is preferably 0 or 1 . In formulae (IX) and (XI) a substituent group for the benzene ring is present at the o- position, m-position, or p-position. In formula (X), a substituent group for the

naphthalene ring is present at the o-position, m-position, p-position, ana-position, E (epi)-position, kata-position, pen-position, pros-position, amphi-position, or 2,7-position. The substituent group for the benzene ring is preferably present at the p-position among the above positions. The substituent group for the naphthalene ring is preferably present at the amphi-position among the above positions.

Preferred are:

H 2 C=CCH— COO-H +OOC CH 3 C=CH 2

In general the liquid crystals compositions or liquid crystal layers are not particularly limited, provided that they contain the mono- or/and multi-polymerizable monomer described above. The liquid crystals compositions or liquid crystal layers can thus be made of any of various liquid crystal materials that have been known publicly. The liquid crystals compositions or liquid crystal layers may be made of a liquid crystal material identical to or different from that for display use. In the sixth embodiment the present invention relates to a method for manufacturing a liquid crystal display.

In the context of the present invention the term "display" has the same meaning as the term "panel".

The method for producing the liquid crystal display panel may involve using a polymerization initiator, such as methyl ethyl ketone peroxide and a benzoyl ether- based compound. Preferably, the present invention relates to a method for manufacturing a liquid crystal display comprising applying at least a single LCP onto a siloxane polymer, copolymer or oligomer layer according to the first or second embodiment of the present invention, or preferably on the orientation layer according to the fourth embodiment of the present invention, and polymerizing said LCP.

In general the polymerization of the LCP is conducted by irraditation or at elevated temperature. The LCP may be applied onto the orientation layer in any amount, so the amount is not particularly limited. The amount may be set as appropriate in accordance with, for example, respective thicknesses of the LCP polymer films formed by polymerization of the monomeric LCP. Further the present invention relates to a method for manufacturing a liquid crystal display comprising bringing into contact a liquid crystal composition comprising a polymerizable liquid crystal monomer as described above, or a polymer or oligomer, which is the polymerized form of said poylmerizable liquid crystal monomer, with at least a single orientation layer according to the present invention, preferably two orientation layers facing each other, and polymerising said polymerizable liquid crystal monomer.

Generally the polymerization methods are not limited so far as they have no adverse effects on the manufactured device. Preferably the polymerization is conducted by irradiation, especially UV radiation, or by heat.

More specifically the process for the preparation of liquid crystal displays, preferably LCDs comprising planar alignment of liquid crystals, more especially LCDs comprising the IPS mode, comprising an orientation layer according to the present invention and electrodes, comprises performing an exposure, preferably a first exposure, of the material with the polarised light, wherein the exposure induces an orientation direction of the liquid crystals perpendicular to polarised light, or/and wherein an exposure, preferably a first exposure, induces an orientation direction of the liquid crystals and polarised light direction make an angle higher than 70°, or/andwherein an exposure, preferably a first exposure, with polarized light is conducted with an angle >70° between the electrode and the polarized light direction.

The seventh object of the present invention relates to optical or electro-optical unstructured of structured elements comprising the copolymer according to the present invention or the orientation layer according to the present invention.

In a preferred embodiment the element is a liquid crystal display cell. In the context of the present invention elements, device, cell, structure all refer to objects comprising polymerized or polymerizable liquid crystal to be oriented with the copolymer according to the present invention.

Preferably, the present invention further relates to unstructured or structured elements optical or electrooptical devices, especially a LCD, comprising a pair of substrates facing each other; wherein the substrates is provided with a pair of orientation layers according to the present invention and

- a) optionally, a LCP polymer film, wherein said polymer film is formed on that orientation layer, or

- b) a liquid crystal composition, preferably comprising a polymer made from at least a polymerizable liquid crystal monomer, wherein said liquid crystal composition is sandwiched between the pair of orientation layers. The present invention also relates to the use of such orientation layers for the alignment, preferably planar alignment, of liquid crystals, preferably in the manufacture of unstructured or structured optical-or electro-optical elements, preferably in the production of hybrid layer elements. Preferably, these optical or electro-optical devices have at least one orientation layer as well as unstructured and structured optical elements and multi-layer systems. The layer or each of the layers may contain one or more regions of different spatial orientation.

Polarised light direction shall mean the intersection line of the alignment layer surface and the plane of polarization of the polarised light during the exposure. If the polarised light is elliptically polarized, the plane of polarization shall mean the plane defined by the incident direction of the light and by the major axis of the polarization ellipse.

The term polarised light direction is used in the context of the present invention not only to describe a direction for the duration of the exposure process, but also after exposure to refer to the direction of the polarised light on the alignment layer as it was applied during exposure.

The electrodes are preferably in the form of parallel stripes, zig-zag or comb-like electrodes.

Preferably, the present invention concerns an optical and electro-optical unstructured or structured constructional elements, preferably liquid crystal display cells, multi-layer and hybrid layer elements, comprising at least one polymer layer, copolymer or oligomer layer according to the present invention.

The present invention the wording optical or electro-optical elements has preferably the meaning of multilayer systems, or devices for the preparation of a display waveguide, a security or brand protection element, a bar code, an optical grating, a filter, a retarder, a compensation film, a reflectively polarizing film, an absorptive polarizing film, an anisotropically scattering film compensator and retardation film, a twisted retarder film, a cholesteric liquid crystal film, a guest-host liquid crystal film, a monomer corrugated film, a smectic liquid crystal film, a polarizer, a piezoelectric cell, a thin film exhibiting non linear optical properties, a decorative optical element, a brightness enhancement film, a component for wavelength-band-selective compensation, a component for multi- domain compensation, a component of multiview liquid crystal displays, an achromatic retarder, a polarization state correction / adjustment film, a component of optical or electro-optical sensors, a component of brightness enhancement film, a component for light-based telecommunication devices, a G/H-polarizer with an anisotropic absorber, a reflective circular polarizer, a reflective linear polarizer, a MC (monomer corrugated film), twisted nematic (TN) liquid crystal displays, hybrid aligned nematic (HAN) liquid crystal displays, electrically controlled birefringence (ECB) liquid crystal displays, supertwisted nematic (STN) liquid crystal displays, optically compensated birefringence (OCB) liquid crystal displays, pi-cell liquid crystal displays, PLS technology (plane to line switching), PS-IPS (polymer stabilized IPS), in-plane switching (IPS) liquid crystal displays, such as IPS modes like S-IPS (Super IPS), AS-IPS (Advanced super IPS), E- IPS (Enhanced IPS), H-IPS (Horizontal IPS), UH-IPS, S-IPS II, e-IPS, p-IPS

(performance IPS); Field induced photoreactive alignment IPS, fringe field switching (FFS) liquid crystal displays; (FPA) field-induced photo-reactive alignment; hybrid FPA; VA-IPS mode liquid crystal displays, or displays using blue phase liquid crystals; all above display types are applied in either transmissive or reflective or transflective mode. More preferred optical or electro-optical elements are PLS technology (plane to line switching), PS-IPS (polymer stabilized IPS), in-plane switching (IPS) liquid crystal displays, such as IPS modes like S-IPS (Super IPS), AS-IPS (Advanced super IPS), E- IPS (Enhanced IPS), H-IPS (Horizontal IPS), UH-IPS, S-IPS II, e-IPS, p-IPS

(performance IPS); Field induced photoreactive alignment IPS, fringe field switching (FFS) liquid crystal displays; (FPA) field-induced photo-reactive alignment; hybrid FPA; VA-IPS mode liquid crystal displays, or displays using blue phase liquid crystals; all above display types are applied in either transmissive or reflective or transflective mode. The advantages of the present invention could not be foreseen by a skilled person. It has surprisingly been found, that the copolymers of the present invention, upon irradiation with polarized light, orient polymerized or polymerizable liquid crystals. Further, said photo-alignment material shows good and homogenous planar orientation quality and good electro-optical qualities as for example good voltage holding ratios or good image sticking properties, especially at high annealing temperatures. The further examples will demonstrate that the copolymers of the present invention have good or very good image sticking properties, contrast ratios and voltage holding ratios.

The further examples are a non-limiting selection of examples which will further explain the invention. Examples

Definitions used in the examples:

H NMR: H nuclear magnetic resonance spectroscopy

DMSO-d 6 : dimethylsulfoxid deuterated

300MHz: 300 Megahertz

M : multiplett

D : doublet

Dd : doublet doublet

t : triplet

s : singulet

q : quadruplet

qi : quintet

br : broad peak

HCI : hydrogen chloride

HCI solution (25%) : volume percent

NaOH : sodium hydroxide

NaOH (30%) : weight percent

MeOH: methanol

EtOAc: ethyl acetate

NMP: N-methyl-2-pyrrolidone

THF: tetrahydrofuran

TBME: tert. butyl methyl ether

DMF: N,N-dimethylformamide

DBU: 1 ,8-Diazabicyclo[5.4.0]undec-7-ene

NaHC0 3 : sodium bicarbonate

H 2 S0 4 : sulphuric acid

RT : room temperature, usually in the range of 18 °C to 28 °C

[η]: viscosity

v.t.% : volume procent

GPC: Gel permeation chromatography. GPC is measured with UV detector and with polystyrene as standards.

Mw. Molecular weight PI: Polydispersity index

MLC7067: is a mixture of liquid crystal available from Merck KGA with a dielectric anisotropy of 10.3, an optical anisotropy of 0.1025 and a rotational viscosity of 81 m.Pa.s.

Example 1 :

Preparation of 4-(3-cvanopropoxy)benzoic acid compound 1

46.8 g (307 mmol) of methyl-4-hydroxybenzoate, 50 g (338 mmol) of 4- bromobutanenitrile are dissolved in 535 mL of NMP. 5.1 g (31 mmol) of potassium iodide and 128 g (93 mmol) of potassium carbonate are added and the suspension is heated up to 80 °C. After 48h, a mixture of 15 g of sodium hydroxide and 49 ml of water is added. The reaction mixture is heated up to 100 ^ for 5 hours. Then the solution is cooled down and 480 mL of water is added. The aqueous layer is removed and the organic layer is poured to 1 .5 L of icy water. 81 mL of a 25% HCI solution is added. The precipitate is filtered off and washed with 250 mL of water. The resulting product is incorporated in 600 mL of MeOH. The suspension is then stirred for 1 hour and filtered off to give 50.1 g (80%) of compound 1 as a white powder used without further purification.

Example 2:

Preparation of (2£)-3-(4-{[4-(3-nitrilepropoxy)benzoyl1oxy)phenyl)prop-2-e noic acid compound 2

16.8 g (82 mmol) of 1 is suspended in 56 mL of toluene and few drops of DMF are added. The suspension is heated up to 75 °C and 10.7g (90 mmol) of thionylchloride are added. After 2 hours, the excess of thionyl chloride is removed under pressure. The solution is cooled down to room temperature. 10.2 g (83 mmol) of 4- hydroxybenzaldehyde, 0.5 g (4 mmol) of 4-diaminopyridine and 28 g (355 mmol) of pyridine are added. After 3 hours, 14.5 g (140 mmol) of malonic acid and 3 g (42 mmol) of pyrrolidine are added. The reaction mixture is allowed to react at 80 'Ό for 30 min. 16.8 mL of MeOH are then incorporated and the suspension is cooled down and kept at 0°C for 1 hour. The product is filtered off and suspended for 2 hours in a solution of 57 mL of MeOH, 1 1 mL of water and 7.5 g of a 25% HCI solution. The solid is filtered off and washed with MeOH and heptane. The product is crystallized in acetonitrile to give 23 g (80%) of compound 2 as a white powder.

H NMR (300MHz) in DMSO-d 6 : 12.44 (s, 1 H), 8.10 (d, 2H), 7.80 (d, 2H), 7.63 (d, 1 H), 7.33 (d, 2H), 7.15 (d, 2H), 6.55 (d, 1 H), 4.17 (t, 2H), 2.69 (t, 2H), 2.08 (qi, 2H)

Example 3:

Preparation of methyl 6-[4-(cvanomethyl)phenoxy1hexanoate compound 3

5.65 g (42 mmol) of (4-hydroxyphenyl)acetonitrile and 9.1 g (44 mmol) of methyl 6- bromohexanoate are dissolved in 75 ml_ of N,N-dimethylformamide. 6.45 g (46 mmol) of potassium carbonate and 0.7 g (4 mmol) of potassium iodide are added and the suspension is heated to 80 'C. After 5h, The mixture is allowed to cool down to 0°C with an ice bath. 375 ml of H 2 0 and 12.4 g of HCI 37% were slowly added. The precipitate is filtered off and washed with 500 ml of H 2 0. The white solid is dried overnight at 40 ^ under vacuum to give 1 1 .2 g of 6-[4-(cyanomethyl)phenoxy]hexanoic acid.

Examples 3a, 3b, 3c and 3d:

The compounds 4, 5, 6, 7 are prepared according to the process described for compound 3 with the proviso that methyl 6-bromohexanoate is replaced respectively by methyl 4-bromobutanoate, methyl 5-bromopentanoate, methyl 8-bromooctanoate, methyl 1 1 -bromoundecanoate.

Example 4:

Preparation of methyl 6-(4-formylphenoxy)hexanoate compound 8

Compound 8 is prepared according to the process described for compound 3 with the proviso that (4-hydroxyphenyl)acetonitrile is replaced by 4-hydroxybenzaldehyde. Examples 4a, 4b, 4c and 4d:

Compounds 9, 10, 1 1 , 12 are prepared according to the process described for compound 8 with the proviso that methyl 6-bromohexanoate is replaced respectively by methyl 4-bromobutanoate, methyl 5-bromopentanoate, methyl 8-bromooctanoate, methyl 1 1 -bromoundecanoate.

Example 5:

Preparation of 6-[4-(1 -cvano-2-phenyl-vinyl)phenoxy1hexanoic acid compound 13 8.85 g (35 mmol) of compound 3, 3.8 g (35 mmol) of benzaldehyde are dissolved in 30 ml_ of propan-2-ol. The solution is heated to 60 °C and 1 .77 ml_ (1 .9 mmol) of a 2M solution of tetrabuthylamoniumhydroxyde in methanol are added dropwise. After 2h at 60 °C, the reaction mixture is cooled down to 0°C. The precipitate is filtered off, washed with cold propan-2-ol. 7.4 g of the solid was dissolved in 55 ml of dimethylacetamide and then a solution of 1 .35 g of NaOH and 1 .2 g of H 2 0 in 55 ml of MeOH was added into. When the reaction is completed, the mixture reaction is slowly poured onto a solution of 13.2 g of 25% HCI and 316 g of H 2 0. The precipitate is filtered off and dried under vacuum to give 6.5 g of a white powder.

H NMR (300MHz) in DMSO-d 6 : 12.00 (s, 1 H), 7.90 (m, 3H), 7.70 (d, 2H), 7.53 (m, 3H), 7.07 (d, 2H), 4.03 (t, 2H), 2.25 (t, 2H), 1 .75 (qi, 2H), 1 .59 (qi, 2H), 1 .44 (m, 2H).

Examples 5a, 5b, 5k. 5I:

The compounds 14, 15, 23, 24 are prepared according to the process described for compound 13 with the proviso that compound 3 is replaced by compound 5, respectively compound 7, respectively compound 6, respectively compound 4.

H NMR (300MHz) in THF-d8 of compound 14: 10.68 (s, 1 H), 7.95 (dd, 2H), 7.70 (m, 3H), 7.47 (m, 3H), 7.04 (d, 2H), 4.08 (t, 2H), 2.35 (t, 2H), 1 .83 (m, 4H).

H NMR (300MHz) in DMSO-d 6 of compound 15: 1 1 .95 (s, 1 H), 7.90 (m, 3H), 7.70 (d, 2H), 7.52 (m, 3H), 7.07 (d, 2H), 4.03 (t, 2H), 2.19 (t, 2H), 1 .73 (qi, 2H), 1 .2 (m, 14H). H NMR (300MHz) in DMSO-d 6 of compound 23: 1 1 .98 (s, 1 H), 7.90 (m, 3H), 7.71 (d, 2H), 7.59 (br., 3H), 7.06 (dd, 2H), 4.03 (t, 2H), 2.24 (t, 2H), 1 .75 (m, 2H), 1 .6-1 .2 (m, 8H).

H NMR (300MHz) in DMSO-d 6 of compound 24: 12.01 (s, 1 H), 7.91 (m, 3H), 7.71 (d, 2H), 7.52 (m, 3H), 7.08 (d, 2H), 4.03 (t, 2H), 2.41 (t, 2H), 1 .97 (qi, 2H).

Examples 5c and 5d: The compounds 17, 18 are prepared according to the process described for compound 13 with the proviso that benzaldehyde is replaced by 4-fluorobenzaldehyde, respectively by 4-trifluoromethylbenzaldehyde.

H NMR (300MHz) in DMSO-d 6 of compound 17: 12.04 (s, 1 H), 7.98 (dd, 2H), 7.92 (s, 1 H), 7.68 (d, 2H), 7.38 (dd, 2H), 7.07 (d, 2H), 4.03 (t, 2H), 2.24 (t, 2H), 1 .74 (qi, 2H), 1 .58 (qi, 2H), 1 .45 (m, 2H).

H NMR (300MHz) in DMSO-d 6 of compound 18: 12.05 (s, 1 H), 8.06 (m, 3H), 7.89 (d, 2H), 7.73 (d, 2H), 7.09 (d, 2H), 4.05 (t, 2H), 2.30 (t, 2H), 1 .80 (m, 4H).

Example 5e:

The compound 19 is prepared according to the process described for compound 13 with the proviso that compound 3 is replaced by compound 8 and benzaldehyde is replaced by benzonitrile.

H NMR (300MHz) in DMSO-d 6 of compound 19: 12.00 (s, 1 H), 7.95 (m, 3H), 7.74 (d, 2H), 7.42 (m, 3H), 7.10 (d, 2H), 4.06 (t, 2H), 2.25 (t, 2H), 1 .75 (qi, 2H), 1 .58 (qi, 2H), 1 .45 (m, 2H). Example 5f, 5i:

The compounds 20, 25 are prepared according to the process described for compound 19 with the proviso that compound 8 is replaced by compound 12, respectively by compound 10.

H NMR (300MHz) in DMSO-d 6 of compound 20: 12.00 (s, 1 H), 7.95 (m, 3H), 7.74 (d, 2H), 7.42 (m, 3H), 7.10 (d, 2H), 4.06 (t, 2H), 2.19 (t, 2H), 1 .74 (qi, 2H), 1 .40 (m, 14H). H NMR (300MHz) in DMSO-d 6 of compound 25: 12.05 (s, 1 H), 7.94 (m, 3H), 7.73 (d, 2H), 7.51 (m, 3H), 7.1 1 (d, 2H), 4.07 (t, 2H), 2.30 (t, 2H), 1 .80-1 .60 (m, 4H). Example 5q:

The compound 21 is prepared according to the process described for compound 19 with the proviso that compound 8 is replaced by compound 10 and benzaldehyde is replaced by 4-trifluoromethylbenzaldehyde. H NMR (300MHz) in DMSO-d 6 of compound 21 : 12.05 (s, 1 H), 8.13 (s, 1 H), 7.97 (m, 4H), 7.86 (d, 2H), 7.13 (d, 2H), 4.09 (t, 2H), 2.31 (t, 2H), 1 .76 (m, 4H).

Example 5h:

The compound 22 is prepared according to the process described for compound 21 with the proviso that 4-trifluoromethylbenzaldehyde is replaced by 2-(3,5- dimethoxyphenyl)acetonitrile

H NMR (300MHz) in DMSO-d 6 of compound 21 : 12.05 (s, 1 H), 7.96 (m, 3H), 7.1 1 (d, 2H), 6.86 (d, 2H), 6.57 (s, 1 H), 4.07 (t, 2H), 3.82 (s, 6H), 2.15 (t, 2H), 1 .70 (m, 4H).

Example 5i:

The compound 26 is prepared according to the process described for compound 21 with the proviso that 4-trifluoromethylbenzaldehyde is replaced by 4- fluorobenzaldehyde

H NMR (300MHz) in DMSO-d 6 of compound 26: 12.05 (s, 1 H), 7.92 (m, 3H), 7.77 (m, 2H), 7.35 (t, 2H), 7.10 (d, 2H), 4.07 (t, 2H), 2.30 (m, 2H), 1 .80-1 .60 (m, 4H). Example 6:

Preparation of the polymer P3

5.05 g (14 mmol) of compound 2 and 0.27 g (0.7 mmol) of compound 14 are suspended in 35 ml of 4-Methyl-2-pentanone and 0.54 g of H 2 0. 0.16 g (0.75 mmol) of tetraethylammonium bromine are added to give a white suspension. 4.25 g (14.2 mmol) of 2-(3,4-Epoxycyclohexyl)ethyltriethoxysilane are added dropwise. The mixture is stirred at reflux for 48h. The suspension is allowed to cool down. The upper liquid phase is removed and the polymer is rinsed with 25 ml of 4-Methyl-2-pentanone. 20 mL of tetrahydrofurane and 50 ml of ethylacetate are added and the mixture is extracted with 15 ml of water. The resulting solution is poured slowly into 240 mL of cold tert- butyl methyl ether. The solid is filtered off and washed with 10 mL of tert-butyl methyl ether. The resulting white solid is dried under vacuum to give 5.45 g of polymer.

Mw (DA): 171 120, Mn (DA):75 600, PI: 2.26 Example 7:

Preparation of the polymer P2

The polymer P2 is prepared according to the process described for the polymer P1 with the proviso that 5.05 g (14 mmol) of compound 2 and 0.162 g (0.56 mmol) of compound 14 are used.

Mw (DA):56450 , Mn (DA):34780, Pl:1 .62

Example 8:

Preparation of the polymer P1

The polymer P3 is prepared according to the process described for the polymer P1 with the proviso that 5.05 g (14 mmol) of compound 2 and 0.216 g (0.42 mmol) of compound 14 are used.

Mw (DA):40960 , Mn (DA):25866, PI: 1 .58

Example 9:

Preparation of the polymer P4

The polymer P4 is prepared according to the process described for the polymer P1 with the proviso that 5.05 g (14 mmol) of compound 2 and 0.378 g (0.98 mmol) of compound 14 are used.

Mw (DA):95700 , Mn (DA):59550, Pl:1 .6 Example 10:

Preparation of the polymer P5

The polymer P5 is prepared according to the process described for the polymer P1 with the proviso that 5.05 g (14 mmol) of compound 2 and 0.486 g (1 .26 mmol) of compound 14 are used.

Mw (DA):74130 , Mn (DA):41580, Pl:1 .78

Example 1 1 : Preparation of the polymer P6

The polymer P6 is prepared according to the process described for P1 with the proviso that compound 14 is replaced by compound 15.

Mw (DA): 98100, Mn (DA): 41400, PI: 2.37

Example 12:

Preparation of the polymer P7

The polymer P7 is prepared according to the process described for P2 with the proviso that compound 14 is replaced by compound 13.

Mw (DA): 63100 , Mn (DA): 36600, PI: 1 .72

Example 13: Preparation of the polymer P8

The polymer P8 is prepared according to the process described for P3 with the proviso that compound 14 is replaced by compound 19.

Mw (DA): 86080, Mn (DA):41030, PI: 2.1 Example 14:

Preparation of the polymer P9

The polymer P9 is prepared according to the process described for P1 with the proviso that compound 14 is replaced by compound 20.

Mw (DA): 1 17320 , Mn (DA): 65240, Pl:1 .8

Example 15:

Preparation of the polymer P10

The polymer P10 is prepared according to the process described for P3 with the proviso that compound 14 is replaced by compound 17.

Mw (DA): 128800, Mn (DA):54640, PI: 2.36

Example 16: Preparation of the polymer P1 1

The polymer P1 1 is prepared according to the process described for P2 with the proviso that compound 14 is replaced by compound 17.

Mw (DA): 40390, Mn (DA):, PI: 26650, PI: 1 .52

Example 17:

Preparation of the polymer P12

The polymer P12 is prepared according to the process described for P3 with the proviso that compound 14 is replaced by compound 21 .

Mw (DA): 81530 , Mn (DA): 44500, PI: 1 .83

Example 18:

Preparation of the polymer P13

The polymer P13 is prepared according to the process described for P3 with the proviso that compound 14 is replaced by compound 18.

Mw (DA): 77920 , Mn (DA): 40320, Pl:1 .93

Example 19:

Preparation of the polymer P14

The polymer P14 is prepared according to the process described for P3 with the proviso that compound 14 is replaced by compound 22.

Mw (DA): 72780 , Mn (DA): 40218, PI: 1 .8

Preparation of the polymer P15

The polymer P15 is prepared according to the process described for the polymer P1 with the proviso that compound 14 is replaced by compound 23

Mw (DA):124830 , Mn (DA):43000, Pl:2.9

Preparation of the polymer P16 The polymer P16 is prepared according to the process described for the polymer P3 with the proviso that compound 14 is replaced by compound 23

Mw (DA):131250 , Mn (DA):45950, Pl:2.85 Preparation of the polymer P17

The polymer P17 is prepared according to the process described for the polymer P1 with the proviso that compound 14 is replaced by compound 24

Mw (DA):104670 , Mn (DA):37800, Pl:2.8 Preparation of the polymer P18

The polymer P18 is prepared according to the process described for the polymer P3 with the proviso that compound 14 is replaced by compound 24

Mw (DA):123240 , Mn (DA):46560, Pl:2.7 Preparation of the polymer P19

The polymer P18 is prepared according to the process described for the polymer P3 with the proviso that compound 14 is replaced by compound 25

Mw (DA):125500 , Mn (DA):49740, Pl:2.5 Preparation of the polymer P20

The polymer P20 is prepared according to the process described for the polymer P3 with the proviso that compound 14 is replaced by compound 20

Mw (DA):88125 , Mn (DA):32830, Pl:2.7 Preparation of the polymer P21

The polymer P21 is prepared according to the process described for the polymer P4 with the proviso that compound 14 is replaced by compound 17

Mw (DA):901 10 , Mn (DA):43400, Pl:2 Preparation of the polymer P22

The polymer P22 is prepared according to the process described for the polymer P1 with the proviso that compound 14 is replaced by compound 26

Mw (DA):87260 , Mn (DA):45360, Pl:1 .9 Preparation of the polymer P23

The polymer P23 is prepared according to the process described for the polymer P3 with the proviso that compound 14 is replaced by compound 26

Mw (DA):1 14970 , Mn (DA):48850, Pl:2.4

Example 20:

Comparative example CP1 :

49.2 g of compound 2 are suspended in 375 ml of 4-Methyl-2-pentanone and 5 g of water. 1 .5 g of tetraethyl ammonium bromine are added to give a white suspension. 38.4 g of 2-(3,4-Epoxycyclohexyl)ethyltriethoxysilane are added dropwise. The mixture is stirred at reflux for 48h. The suspension is allowed to cool down. The upper liquid phase is removed and the polymer is rinsed with 150 ml of 4-Methyl-2-pentanone. 140 mL of Tetrahydrofurane are added and the mixture is heated to 50-60 'Ό under stirring until (yellow) solution. The resulting yellowish solution is poured slowly into 1 .5 L of cold cold within 10 mn. The solid is filtered (duration: 2 minutes) onto 15 cm Buchner with paper filter and washed with 500 mL of tert-butyl methyl ether. The resulting white solid (70. Og) is dried under vacuum to give 70 g of polymer.

Mw (DA): 34500, Mn (DA): 22700, PI: 1 .52

Example 21 : Preparation of PAA-1

0.666 g (3.4 mmol) of 1 ,2,3,4-cyclobutanetetracarboxylic acid is added to a solution of 0.69 g (3.47 mmol) of 4-(4-aminophenoxy)aniline in 8.6 g of NMP. Stirring is then carried out at 0°C for 2 hours. The polymer mixture is diluted with 50 mL of NMP, precipitated into 300 mL of water to yield, after drying at 40^ under vacum, 2.1 g of polyamic acid PAA-1 in the form of a white powder.

[η]=0.40 dIJg

Preparation of PAA-2

0.69 g (3.1 mmol) of 2,3,5-tricarboxycyclopentylacetic-1 ,2:3,4-dianhydride is added to a solution of 1 .5 g (3.1 mmol) of 4-(4-aminophenoxy)aniline in 5.1 g of NMP. Stirring is then carried out at 0°C for 2 hours. The polymer mixture is diluted with 30 g of NMP, precipitated into 300 ml_ of water to yield, after drying at 40^ under vacuum, 1 .9 g of polyamic acid PAA-2 in the form of a white powder,

[η] = 0.40dlJg

Preparation of PAA-3

3.2 g (14.1 mmol) of 2,3,5-tricarboxycyclopentylacetic-1 ,2:3,4-dianhydride is added to a solution of 3 g (14.1 mmol) of 4,4'-ethylenedianiline in 35 g of NMP. Stirring is then carried out at 0°C for 2 hours. The polymer mixture is then diluted with 47 g of acetone, precipitated into 500 ml_ of water to yield, after drying at 40^ under vacuum, 6.5 g of polyamic acid PAA-3 in the form of a white powder,

[η] = 0.52 dIJg

Preparation of PAA-4

5.6 g (25.2 mmol) of 2,3,5-tricarboxycyclopentylacetic-1 ,2:3,4-dianhydride is added to a solution of 5 g (25.2 mmol) of 4,4'-methylenedianiline in 60 g of NMP. Stirring is then carried out at 0°C for 2 hours. The mixture is subsequently allowed to react for 1 hour at room temperature. The polymer mixture is then diluted with 100 g of NMP and 78 g of acetone, precipitated into 3500 ml_ of water to yield, after drying at 40^ under vacuum, 14 g of polyamic acid PAA-4 in the form of a white powder,

[η] = 0.52 dIJg

APPLICATION EXAMPLES Example 22:

A liquid crystal cell is prepared wherein the liquid crystal is aligned by photo reactive P1 and the electric field is applied between two plan electrodes on each side of the cell gap.

A 6.3 wt% solution is prepared by mixing P1 and the polyamic acid PAA-1 in ratio of 10:90 per weight % to form a blend composition in NMP and stirred thoroughly till the solid is dissolved. Then a second solvent butyl cellusolve (BC) is added and the whole composition is stirred thoroughly to obtain final solution. The solvent ratio between NMP and butyl cellusolve is 1 :1 . The above polymer solution was spin-coated onto the two ITO coated glass substrates at a spin speed of 3600 rpm for 30seconds. After spin coating the substrates are subjected to baking procedure consisting of pre-baking for 1 .5 minutes at 130 ^ and post-baking for 40 minutes at a temperature of 200°C.The resulting layer thickness is around 90-1 10 nm. The substrates with the coated polymer layer on top are exposed to linearly polarized UV light (LPUV) at an incidence angle of 0° relative to the normal of the substrate surface. The plane of polarization was within the plane spanned by the substrate normal and the propagation direction of the light. The applied exposure dose is 100 mJ/cm 2 . After LPUV exposure, a cell is assembled with the 2 substrates, the exposed polymer layers facing to the inside of the cell. The substrates are adjusted relative to each other such that the induced alignment directions are parallel to each other. The cell is capillary filled with liquid crystal

MLC7067 (Merck KGA), which had a positive dielectric anisotropy. After that, the cell is optionally annealed at 130°C for 30 minutes and cooled down to room temperature. Alignment quality of the liquid crystal in the cell is checked by placing the cell between two crossed polarizers and adjusted to obtain dark state. The alignment quality is defined to be good, if the dark state show no defects and the liquid crystal is well oriented. The alignment quality is defined to be medium if the dark state has light leakage because of slight inhomogeneous orientation of liquid crystal in some areas of the cell. The alignment quality is defined to be worse, if liquid crystal is not oriented with absence of dark state.

The liquid crystal in the cell showed well defined and homogeneous planar orientation of the cell. A tilt angle below 0.2 ° is measured using the rotating analyzer method from Shintech.

Example 22a:

A liquid crystal cell is prepared according to the process described in example 22 except that an incidence angle of 40° relative to the normal of the substrate surface is used for thr linearly polarized UV. The liquid crystal in the cell showed well defined and homogeneous planar orientation before and after thermal annealing of the cell. A tilt angle of about below 0.2° is measured using the rotating analyzer method from

Shintech.

Example 23:

Cells are prepared with P2, P3, P4, P5, P6, P7, P8, P9, P10, P1 1 , P12, P13, P14, P15, P16, P17, P18, P19, P20, P21 , P22, P23 and CP1 according to the process described for example 22. The liquid crystal in all cells showed well defined and homogeneous planar orientation after thermal annealing of the cell. Tilt angles of below 0.2° are measured using the rotating analyzer method from Shintech. Example 24:

The image sticking of the cells made in examples 22 and 23 were measured. The image sticking of an IPS cell is measured by using an Optipro-250 from Shintech. A wavelength of 589 nm is used. The unbiased sample, consisting of 2 independent pixels, is placed between the crossed polarizers with the alignment direction of the sample being parallel to the first polarizer. The Voltage-Transmittance curve of both pixels is measured by applying 60 Hz square wave voltage in order to find the voltage amplitude V 100 for maximum transmittance T 100 and the voltage amplitude V ! at which a transmittance of 1 % is reached (T^O]). A 60 Hz square wave voltage with an amplitude V 100 is applied to the first pixel (called measurement pixel, M) for a time period of 24 hours while the second (reference, R) pixel is remained unbiased. The sample is stored protected from light and at room temperature during this time. After 24 hours the transmittances Ti[24h] are measured again for both pixels by using the same voltages Vi . The image sticking of the sample is:

Image Sticking (24h)= [TM1 (24h)/TM1 (0h)]x[TR1 (0h)/TR1 (24h)]x 100 where M refers to the measurement pixel and R refers to the reference pixel. The image sticking of a cell is considered very good (·) for values below 109%, good (□) for values between 109% to 1 13% and bad (χ) for values above 1 13%.

P8 □

P9 □

P10 □

P1 1 □

P12 □

P13 □

P14 □

P15 □

P16 □

P17 •

P18 □

P19 □

P20 □

P21 □

P22 □

P23 •

CP1 X

As shown by Example 24, the image sticking according to the copolymers according to the present invention is very good or good compared to the image sticking of the comparative example CP1 which is bad.

Example 25:

The alignment quality of the cells from example 22 and example 23 are quantified by contrast ratio (CR). The contrast of an unbiased IPS cell is determined by measuring its light leakage using a transmission microscope consisting of a backlight, polarizer and analyzer, optics (condenser lenses, microscope objective) between the polarizers and a photomultiplier to measure the transmitted light power. As a light source an LED backlight from ELDIM is used, which is similar to the backlight from commercial displays. The measurement area in the focal plane (sample) of the microscope objective is about 1 mm 2 . Without sample the polarizers from the microscope are brought to the perpendicular position (the detector signal displays a minimum value). The unbiased sample is placed under the microscope objective and rotated in-plane until the detector displays a minimum value V 0 (the alignment direction of the cell is parallel to the polarizer). By keeping the in-plane position of the sample, the analyzer rotated by 90° (until the detector displays a maximum value V max . The contrast of the sample is CR = V max /V 0 .

If CR is below 1000 the contrast is said bad, if CR is between 1000 and 2000 CR is medium (·), if CR is between 2000-3000 contrast is said good (□) and if CR is above 3000 CR is said very good (El)

Example 26:

Voltage holding ratio (VHR) of the cells from examples 22 and 23 were measured at room temperature using LCM-1 instrument from Toyo, Japan. The VHR was measured using a short frame period (T). The voltage decay V (at T=20ms) of a voltage surge of 64με with V 0 (V at t=0) = 5V is then measured over a period of T=20ms. The voltage holding ratio is then determined, at room temperature, given by integration of the measurement curve between V 0 and V weighted by the area in the case of 100% VHR. The results show VHR > 99 % for all tested cells.