Description

LIQUID CRYSTAL PHOTO-ALIGNMENT AGENT, LIQUID CRYSTAL PHOTO-ALIGNMENT FILM MANUFACTURED

USING THE SAME

Technical Field

[1] The present invention relates to a liquid crystal photo-alignment agent and a liquid crystal photo-alignment film manufactured using the same. Background Art

[2] A liquid crystal display (LCD) includes a liquid crystal alignment film. The liquid crystal alignment film is mainly made of polymer materials. The liquid crystal alignment film plays a role of a director in aligning liquid crystal molecules. When the liquid crystal molecules are moved by the influence of an electric field to display an image, the liquid crystal alignment film allows them to be oriented in a predetermined direction. Generally, it is necessary to uniformly align the liquid crystal molecules in order to provide uniform brightness and a high contrast ratio to the liquid crystal device.

[3] The conventional method of aligning the liquid crystal includes coating a polymer membrane such as a polyimide on a substrate made of a material such as glass, and rubbing the surface of the substrate with a fiber such as nylon or polyester in a certain direction. However, the rubbing method may cause serious problems while fabricating a liquid crystal panel due to fine dust or electrostatic discharge (ESD) that may be generated while rubbing the polymer membrane with the fiber.

[4] In order to solve the problems of the rubbing method, the photo-radiation method has recently been researched to induce anisotropy to the polymer membrane by irradiating light on the membrane so as to align the liquid crystal molecules.

[5] As polymer membrane materials for the photo- alignment method, polymers having photo-functional groups such as azobenzene, cumarine, chalcone, and cinnamate have been suggested. Such polymers are anisotropically photo-isomerized or photo- cross-linked by being irradiated with polarized light, so as to provide anisotropy to the surface so that it can induce the liquid crystal molecules to align in a certain direction.

[6] The material for the liquid crystal alignment film should have optical stability and thermal stability, as well as no after-image, in order to apply it a substantial liquid crystal display device (LCD). However, the conventional photo- alignment materials have many problems in this respect.

[7] Further, the conventional material for the liquid crystal photo- alignment film is mainly polymeric that has a main chain of a polymer and a side group of a photo- functional group that is capable of inducing the photo-anisotropy, such as azobenzene or cinnamate. When the material for a polymeric liquid crystal photo-alignment film is used, it may cause problems not only in that a lot of photo-energy is required to induce the anisotropy, but also that the thermal stability, optical stability, and electro-optical characteristics are seriously affected by a plurality of unreacted remaining photo- functional groups.

[8] In general, a liquid crystal display is fabricated by coating a liquid crystal photo- alignment agent on a glass substrate deposited with a transparent indium tin oxide (ITO) conductive layer and heating it to form a liquid crystal alignment film, and then combining two substrates oppositely facing each other and implanting the liquid crystals therebetween. Alternatively, a liquid crystal display can be fabricated by dripping liquid crystals on one substrate and combining it with another substrate oppositely facing the one substrate. In particular, a liquid crystal display of the 5 ^th generation or later in a medium- and large- sized product line tends to adopt the latter method.

[9] In general, a liquid crystal photo-alignment film is formed by coating a liquid crystal photo- alignment agent prepared by dissolving polyamic acid or polyimide in an organic solvent on a substrate in a flexo printing method, and then predrying and firing it. When the liquid crystal photo-alignment agent has bad printability, it may have a film thickness deviation, and thereby may have a bad influence on display characteristics of a liquid crystal display including the film.

Disclosure of Invention

Technical Problem

[10] An exemplary embodiment of the present invention provides a liquid crystal photo- alignment agent and a liquid crystal photo- alignment film manufactured using the same.

[11] Another embodiment of the present invention provides a liquid crystal photo- alignment agent having excellent printability and liquid crystal photo-alignment property in that liquid crystal molecules are uniformly and stably aligned in a vertical direction and in that the vertical alignment property is not deteriorated by dropping liquid crystal by one drop filling (ODF), and it is stable for the operation conditions.

[12] A further embodiment of the present invention provides a liquid crystal alignment film having excellent after-image and electro-optical characteristics. Technical Solution

[13] According to one embodiment of the present invention, a liquid crystal photo- alignment agent is provided that includes an epoxy compound represented by the following Chemical Formula 1, and a polymer selected from polyamic acid, polyimide, and a mixture thereof.

[14] [Chemical Formula 1]

[16] In the above Chemical Formula 1, X is an integer ranging from 1 to 8, and [17] R ₁ is an organic group derived froma cumarin-based photo-diamine, a chalcone- based photo-diamine, or a cinnamate-based photo-diamine.

[18] The epoxy compound may be included in an amount of 0.01 to 60 parts by weight, in an amount of 0.05 to 50 parts by weight, or in an amount of 0.05 to 30 parts by weight based on the 100 parts by weight of the polymer.

[19] The epoxy compound may comprise at least one of compounds represented by the following Chemical Formulae 2 to 4:

[20] [Chemical Formula 2] [21]

[22] [Chemical Formula 3]

[24] wherein, in the above Chemical Formulae 2 and 3, [25] R ₂ to R ₆ and R ₁₃ to R ₁₇ are independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, and a substituted or unsubstituted heteroaryl, and

[26] R ₇ to R ₁₂ , R _1S , and R ₁₉ are independently substituents selected from the group consisting of hydrogen, a Cl to C20 alkyl, a C2 to C20 alkoxy alkyl, a Cl to C20 haloalkyl, and an aromatic group, or substituents selected from the group consisting of a Cl to C6 alkyl, and an alicyclic group.

[27] [Chemical Formula 4]

[29] wherein, in the above Chemical Formula 4, [30] R ₂₀ to R ₂₄ are independently hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl,

[31] R ₂₅ and R ₂₆ are independently hydrogen, a halogen, a cyano, or a substituted or unsubstituted Cl to C 12 alkyl, [32] where in R ₂₅ and R ₂₆ , the substituted alkyl is an alkyl substituted with a halogen or a cyano, an alkyl where at least one of non-adjacent CH ₂ group is substituted with -O-, - CO-O-, -O-CO-, or -CH=CH-, or combinations thereof, and

[33] R ₂₇ to R ₃₀ are independently substituents selected from the group consisting of hydrogen, a Cl to C20 alkyl, a C2 to C20 alkoxy alkyl, a Cl to C20 haloalkyl, and an aromatic group, or substituents selected from the group consisting of a Cl to C6 alkyl, and an alicyclic group.

[34] The polyamic acid may be including a repeating unit represented by the following Chemical Formula 5.

[35] [Chemical Formula 5]

[37] wherein, in the above Chemical Formula 5, [38] R ₃₁ is a quadrivalent organic group derived from an aliphatic cyclic acid dianhydride, or an aromatic acid dianhydride, and

[39] R ₃₂ is a divalent organic group derived from a diamine. [40] The polyimide may be including a repeating unit represented by the following Chemical Formula 6: [41] [Chemical Formula 6]

[43] wherein, in the above Chemical Formula 6,

[44] R ₃₃ is a quadrivalent organic group derived from an aliphatic cyclic acid dianhydride, or an aromatic acid dianhydride, and

[45] R ₃₄ is a divalent organic group derived from a diamine, or a divalent organic group derived from a cumarin-based photo-diamine, chalcone-based photo-diamine, or cinnamate-based photo-diamine.

[46] According to another embodiment of the present invention, a liquid crystal photo- alignment film is provided that is manufactured using the liquid crystal photo- alignment agent.

[47] Hereinafter, further embodiments of the present invention will be described in detail.

Advantageous Effects

[48] The liquid crystal photo- alignment agent according to one embodiment of the present invention provides a liquid crystal photo- alignment film having excellent printability on a substrate and excellent reliability and electro-optical characteristics. Best Mode for Carrying out the Invention

[49] Exemplary embodiments of the present invention will hereinafter be described in detail. However, these embodiments are only exemplary, and the present invention is not limited thereto.

[50] As used herein, when specific definition is not provided, the term "alkyl" refers to a

Cl to C30 alkyl, the term "cycloalkyl" refers to a C3 to C30 cycloalkyl, the term "alkylene" refers to a Cl to C6 alkylene, the term "cycloalkylene" refers to a C3 to C30 cycloalkylene, the term "heterocycloalkylene" refers to a C2 to C30 heterocy- cloalkylene, the term "aryl" refers to a C6 to C30 aryl, the term "heteroaryl" refers to a C2 to C30 heteroaryl, the term "arylene" refers to a C2 to C20 arylene, the term "het- eroarylene" refers to a C2 to C30 heteroarylene, the term "alkylaryl" refers to a Cl to C30 alkylaryl, and the term "halogen" refers to F, Cl, Br, or I.

[51] As used herein, the terms "substituted alkyl", "substituted alkylene", "substituted cycloalkylene", "substituted heterocycloalkylene", "substituted aryl", "substituted arylene", "substituted heteroaryl", "substituted heteroarylene", "substituted pyrimidinyl", "substituted pyridinyl", "substituted thiophenyl", "substituted puranyl", "substituted naphthyl", and "substituted phenyl" independently refer to an alkyl, an alkylene, a cycloalkylene, a heterocycloalkylene, an aryl, an arylene, a heteroaryl, a heteroarylene, a pyrimidinyl, a pyridinyl, a thiophenyl, a puranyl, a naphthyl, and a phenyl substituted with a halogen, a Cl to C30 alkyl, a Cl to C30 haloalkyl, a C6 to C30 aryl, a C2 to C30 heteroaryl, or a Cl to C20 alkoxy.

[52] As used herein, when a specific definition is not provided, the terms "heterocycloalkylene", "heteroaryl", and "heteroarylene" respectively refer to a cycloalkylene, an aryl, and an arylene including one to three hetero atoms selected from the group consisting of N, O, S, Si, and P, and the remaining being ring carbon atoms.

[53] As used herein, when a specific definition is not provided, the terms "alicyclic group" or "aliphatic cyclic group" refer to a C3 to C30 cycloalkyl, a C3 to C30 cycloalkenyl, or a C3 to C30 cycloalkynyl, and the term "aromatic group" refers to a C6 to C30 aryl or a C2 to C30 heteroaryl.

[54] In addition, " "λ" " refers to a part connecting the same or different atoms or chemical formulae.

[55] The liquid crystal photo- alignment agent according to one embodiment of the present invention includes an epoxy compound represented by the following Chemical Formula 1, and a polymer selected from polyamic acid, polyimide, or a mixture thereof.

[56] [Chemical Formula 1]

[58] In the above Chemical Formula 1, X is an integer ranging from 1 to 8, and

[59] Ri is an organic group derived from a cumarin-based photo-diamine, a chalcone- based photo-diamine, or a cinnamate-based photo-diamine.

[60] Hereinafter, each component is described in detail.

[61] (A) Epoxy Compound

[62] The epoxy compound may be represented by Chemical Formula 1.

[63] The epoxy compound may be included in an amount of 0.01 to 60 parts by weight, in one embodiment at 0.05 to 50 parts by weight, and in another embodiment at 0.05 to 30 parts by weight based on the 100 parts by weight of the polymer (polyamic acid, polyimide, or a mixture thereof). When the epoxy compound is included in the amount range, it is useable for a photo-alignment agent since it is suitably photo-polymerized while the printability and flatness are not deteriorated while it is coated on a substrate. [64] Non-limiting example of the epoxy compound includes at least one of compounds represented by the following Chemical Formulae 2 to 4.

[65] [Chemical Formula 2]

[67] [Chemical Formula 3]

[69] In the above Chemical Formulae 2 and 3, [70] R ₂ to R ₆ and R ₁₃ to R _n are independently hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl, and

[71] R ₇ to R ₁₂ , Ri ₈ , and R ₁₉ are independently substituents selected from the group consisting of hydrogen, a Cl to C20 alkyl, a C2 to C20 alkoxy alkyl, a Cl to C20 haloalkyl, and an aromatic group, or substituents selected from the group consisting of a Cl to C6 alkyl, and an alicyclic group.

[72] [Chemical Formula 4]

[74] In the above Chemical Formula 4, [75] R ₂₀ to R ₂₄ are independently hydrogen, a substituted or unsubstituted alkyl, a sub- stituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl,

[76] R ₂₅ and R ₂₆ are independently hydrogen, a halogen, a cyano, or a substituted or unsubstituted Cl to C 12 alkyl,

[77] where in R ₂₅ and R ₂₆ , the substituted alkyl is an alkyl substituted with a halogen or a cyano, an alkyl where at least one of non-adjacent CH ₂ groups is substituted with -O-, CO-O-, -O-CO-, or -CH=CH-, or combinations thereof, and

[78] R ₂₇ to R ₃₀ are independently substituents selected from the group consisting of hydrogen, a Cl to C20 alkyl, a C2 to C20 alkoxy alkyl, a Cl to C20 haloalkyl, and an aromatic group, or substituents selected from the group consisting of a Cl to C6 alkyl, and an alicyclic group.

[79] (B) Polymer

[80] The polymer is selected from polyamic acid, polyimide, or a mixture thereof. When the polyamic acid is mixed with polyimide, it is included in a ratio of 1 to 99 wt% and 99 to 1 wt%. In addition, the amount of polymer is included at 0.01 to 30 wt%, and in another embodiment, at 1 to 15 wt%, based on 100 wt% of the total solution.

[81] (B-I) Polyamic Acid

[82] The polyamic acid for the liquid crystal photopolymer may include any polyamic acid synthesized from an acid dianhydride and a diamine.

[83] The acid dianhydride may include an aliphatic cyclic acid dianhydride, an aromatic acid dianhydride, or a mixture thereof. The diamine may independently include an aromatic diamine or a functional diamine, or a mixture of an aromatic diamine and a functional diamine.

[84] The method of preparing polyamic acid by copolymerizing the acid dianhydride and the diamine may include any conventional method known for copolymerizing the polyamic acid.

[85] A non-limiting example of the polyamic acid according to one embodiment of the present invention may be including a repeating unit represented by the following Chemical Formula 5.

[86] [Chemical Formula 5]

[88] In the above Chemical Formula 5,

[89] R _3I is a quadrivalent organic group derived from an aliphatic cyclic acid dianhydride, or an aromatic acid dianhydride, and [90] R ₃₂ is a divalent organic group derived from the diamine.

[91] (B - 1 - 1 ) Acid dianhydride

[92] (B -1-1-1) Aliphatic cyclic acid dianhydride

[93] Examples of the aliphatic cyclic acid dianhydride include

1,2,3,4-cyclobutanetetracarboxylic acid dianhydride (CBDA), 5- (2,5-dioxotetrahydropuryl)-3-methylcyclohexene- 1 ,2-dicarboxylic acid anhydride (DOCDA), bicyclooctene-2,3,5,6-tetracarboxylic acid dianhydride (BODA), 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride (CPDA), 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride CHDA), l,2,4-tricarboxyl-3-methylcarboxyl cyclopentane dianhydride, 1,2,3,4-tetracarboxyl cyclopentane dianhydride, or mixtures thereof, but are not limited thereto.

[94] The quadrivalent organic group derived from the aliphatic cyclic acid dianhydride may have at least one structure of functional groups represented by the following Chemical Formulae 7 to 11.

[95] [Chemical Formula 7]

[97] [Chemical Formula 8]

[99] [Chemical Formula 9]

[101] [Chemical Formula 10] [102]

[103] [Chemical Formula 11]

[105] In the above Chemical Formulae 7 to 11, [106] R ₄₀ is a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl, n ₄₀ is an integer ranging from 0 to 3, and

[107] R _4I to R ₄₇ are independently hydrogen, a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl.

[108] (B- 1-1-2) Aromatic acid dianhydride [109] Examples of the aromatic acid dianhydride include pyromellitic acid dianhydride (PMDA), biphthalic acid dianhydride (BPDA), oxydiphthalic acid dianhydride (ODPA), benzophenone tetracarboxylic acid dianhydride (BTDA), hexafluoroiso- propylidene diphthalic acid dianhydride (6-FDA), or mixtures thereof, but are not limited thereto.

[HO] The quadrivalent organic group derived from the aromatic acid dianhydride may have at least one structure of functional groups represented by the following Chemical Formulae 12 and 13.

[111] [Chemical Formula 12]

[113] [Chemical Formula 13] [114]

[115] In the above Chemical Formulae 12 and 13,

[116] R ₅ i and R ₅₂ are independently hydrogen, a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl,

[117] R ₅₄ and R ₅₅ are independently a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl,

[118] n ₅₄ and n ₅₅ are independently integers ranging from 0 to 3,

[119] R ₅₃ is -O-; -CO-, a substituted or unsubstituted alkylene such as -C(CF ₃ ) ₂ -, a substituted or unsubstituted cycloalkylene, or a substituted or unsubstituted heterocy- cloalkylene, and

[120] n ₅₃ is an integer of 0 or 1.

[121] (B-l-2) Diamine

[ 122] (B - 1 -2- 1 ) Aromatic diamine

[123] Examples of the aromatic diamine include para-phenylenediamine (p-PDA),

4,4-methylene dianiline (MDA), 4,4-oxydianiline (ODA), meta-bisaminophenoxy diphenylsulfone (m-BAPS), para-bisaminophenoxy diphenylsulfone (p-BAPS), 2,2-bis[(aminophenoxy)phenyl]propane (BAPP), 2,2-bisaminophenoxyphenyl hexaflu- oropropane (HF-BAPP), l,4-diamino-2-methoxybenzene, or mixtures thereof, but are not limited thereto.

[124] The divalent organic group derived from the aromatic diamine may have at least one structure of functional groups represented by the following Chemical Formulae 14 to 16.

[125] [Chemical Formula 14]

[127] [Chemical Formula 15]

[129] [Chemical Formula 16] [130]

[131] In the above Chemical Formulae 14 to 16, [132] R ₆ i, R- ₆₃ , R _ό4 , and R ₆₇ to R ₆₉ are independently a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl, or the above alkyl, aryl, or heteroaryl further including -O-, -COO-, - CONH-, or -OCO-,

[133] R ₆₂ , R ₆₅ , and R ₆₆ are independently -O-, -SO ₂ -, or -C(R')(R")- such as -C(CF ₃ ) ₂ - where R' and R" are independently hydrogen, or a substituted or unsubstituted Cl to C6 alkyl,

[134] n ₆₁ , n ₆₃ , n ₆₄ , and n ₆₇ to n ₆₉ are independently integers ranging from 0 to 4, and [135] n ₆₂ , n ₆₅ , and n ₆₆ are independently integers of 0 or 1. [136] (B -1-2-2) Functional Diamine [137] A functional diamine may be mixed with the aromatic diamine while preparing the polyamic acid in order to provide a liquid crystal alignment layer with an excellent alignment property that easily controls the pretilt angle of liquid crystal molecules. The functional diamine may include compounds represented by the following Chemical Formulae 17 to 19 or a mixture thereof. When the functional diamine is mixed with the aromatic diamine, some of the obtained polyamic acid includes a functional group derived from the aromatic diamine, and the other includes a divalent organic acid derived from the functional diamine.

[138] [Chemical Formula 17]

[140] In the above Chemical Formula 17, [141] R _7I is hydrogen, a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl,

[142] R ₇₂ is a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl, and [143] n ₇₂ is an integer ranging from 0 to 3. [144] [Chemical Formula 18]

π77

[146] In the above Chemical Formula 18, [147] R ₇₃ , R ₇₅ , and R ₇₆ are independently a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl,

[148] R ₇₄ is -O-, -COO-, -CONH-, -OCO-, or a substituted or unsubstituted Cl to ClO alkylene, [149] R ₇₇ is hydrogen, a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl, or the above alkyl, aryl, or heteroaryl further including -O-, -COO-, -CONH-, or -OCO-,

[150] n ₇₃ is an integer ranging from 0 to 3, [151] n ₇₅ and n ₇₆ are independently integers ranging from 0 to 4, and [152] n ₇₄ is an integer of 0 or 1. [153] [Chemical Formula 19]

[155] In the above Chemical Formula 19, [156] R ₈₁ and R ₈₃ are independently a substituted or unsubstituted Cl to C20 alkyl, a sub- stituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl,

[157] R ₈₂ is hydrogen, a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl,

[158] R ₇₈ and R ₇₉ are independently -O- or -COO-,

[159] R ₈₀ is -O-, -COO-, -CONH-, or -OCO-,

[160] n ₈₁ and n ₈₃ are independently integers ranging from 0 to 4, and

[161] n ₇₈ to n ₈₀ are independently integers of 0 or 1.

[162] (B-2) Polyimide

[163] The polyimide may include any one of a polyimide polymer or a polyimide pho- topolymer used for a liquid crystal photopolymer.

[164] The polyimide may be prepared by imidizing the polyamic acid represented by

Chemical Formula 1 or by synthesizing at least one kind of photo-diamine and acid di- anhydride. The detailed descriptions on the method of preparing a polyimide polymer by imidizing polyamic acid and the method of preparing a polyimide photopolymer from a photo-diamine and an acid dianhydride are omitted since they are well known in this art.

[165] Non-limiting example of the polyimide according to one embodiment of the present invention may be including a repeating unit represented by the following Chemical Formula 6.

[166] [Chemical Formula 6]

[168] In the above Chemical Formula 6,

[169] R ₃₃ is a quadrivalent organic group derived from an aliphatic cyclic acid dianhydride or an aromatic acid dianhydride, and

[170] R ₃₄ is a divalent organic group derived from a diamine, or a divalent organic group derived from cumarin-based photo-diamine, chalcone-based photo-diamine, or cinnamate -based photo-diamine.

[171] (B-2-1) Acid Dianhydride

[172] The acid dianhydride for the polyimide may include an aliphatic cyclic acid dianhydride, an aromatic acid dianhydride, or a mixture thereof, and the detailed description is the same as for polyamic acid.

[173] (B-2-2) Photo-diamine

[174] The photo-diamine used for preparing the polyimide may include cinnamate-based photo-diamine, chalcone-based photo-diamine, cumarine-based photo-diamine, or a mixture thereof.

[175] The cinnamate-based photo-diamine may include a compound represented by the following Chemical Formula 20, a compound represented by the following Chemical Formula 21, or a mixture thereof; the chalcone-based photo-diamine may include a compound represented by the following Chemical Formula 22; and the cumarine-based photo-diamine may include a compound represented by the following Chemical Formula 23.

[176] [Chemical Formula 20]

H ₀ M

(R Q2) ⁿ 92

[178] In the above Chemical Formula 20, [179] R ₉ i is hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl,

[180] R ₉₂ is a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl, and

[181] n ₉₂ is an integer of 0 to 3. [182] [Chemical Formula 21] [183] (Rg ₄ )H ₉₄

[184] In the above Chemical Formula 21, [185] R ₉₇ is an aromatic diamine group, a diamine group substituted with a substituted or unsubstituted Cl to C24 linear or branched alkylene, or combinations thereof,

[186] where in R ₉₇ , the substituted alkylene is a alkylene substituted with a halogen, or a cyano; an alkylene where at least one of non-adjacent CH ₂ groups is substituted with a substituted or unsubstituted arylene, a substituted or unsubstituted heteroarylene, a substituted or unsubstituted cycloalkylene, a substituted or unsubstituted heterocy- cloalkylene-O-, -CO-, -CO-O-, -O-CO-, -Si(CH ₃ ) ₂ -O-Si(CH ₃ ) ₂ -, -NR'-, -NR'-CO-, - CO-NR'-, -NR'-CO-O-, -O-CO-NR'-, -CH=CH-, -C≡C-, or -O-CO-O- (where R' is hydrogen, or a substituted or unsubstituted Cl to C6 alkyl); or combinations thereof,

[187] R ₉₄ is a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl, n ₉₄ is an integer ranging from 0 to 4,

[188] R ₉₅ and R ₉₆ are independently hydrogen, a halogen, a cyano, or a substituted or unsubstituted Cl to C 12 alkyl,

[189] where in R ₉₅ and R ₉₆ , the substituted alkyl is an alkyl substituted with a halogen or a cyano, an alkyl where at least one of non-adjacent CH ₂ groups is substituted with -O-, CO-O-, -O-CO-, or -CH=CH-, or combinations thereof, and

[190] R ₉₃ is a substituted or unsubstituted alkyl; a substituted or unsubstituted alkylaryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted pyrimidinyl, a substituted or unsubstituted pyridinyl, a substituted or unsubstituted thiophenyl, a substituted or unsubstituted puranyl, a substituted or unsubstituted naphthyl, or a substituted or unsubstituted phenyl,

[191] where in R ₉₃ , the substituted alkyl is an alkyl substituted with a halogen or a cyano, an alkyl where at least one of non-adjacent CH ₂ groups is substituted with -O-, - CO-O-, -O-CO-, or -CH=CH-, or combinations thereof, and

[192] the substituted alkylaryl is an alkylaryl where at least one of non-adjacent CH ₂ groups is substituted with -O-, -CO-O-, -O-CO-, or -CH=CH-.

[193] [Chemical Formula 22]

[ ¹⁹⁴ J (Ri ₀₂ )H ₁₀₂ (Rio5)ni os

[195] In the above Chemical Formula 22,

[196] Rioi is an aromatic diamine group, a diamine group substituted with a substituted or unsubstituted Cl to C24 linear or branched alkylene, or combinations thereof,

[197] where in Ri _0I , the substituted alkylene is a alkylene substituted with a halogen, or a cyano; an alkylene where at least one of non-adjacent CH ₂ groups is substituted with a substituted or unsubstituted arylene, a substituted or unsubstituted heteroarylene, a substituted or unsubstituted cycloalkylene, a substituted or unsubstituted heterocy- cloalkylene-O-, -CO-, -CO-O-, -O-CO-, -Si(CH ₃ ) ₂ -O-Si(CH ₃ ) ₂ -, -NR'-, -NR'-CO-, - CO-NR'-, -NR'-CO-O-, -0-CO-NR'-, -CH=CH-, -C≡C-, or -O-CO-O- (where R' is hydrogen; or a substituted or unsubstituted Cl to C6 alkyl); or combinations thereof,

[198] Ri ₀₂ and Ri ₀₅ are independently a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted hetero aryl, ni ₀₂ and ni ₀₅ are independently integers ranging from 0 to 4,

[199] R ₁₀₃ and R ₁₀₄ are independently hydrogen, a halogen, a cyano, or a substituted or un- substituted Cl to C 12 alkyl, [200] where in R ₁₀₃ and R ₁₀₄ , the substituted alkyl is an alkyl substituted with a halogen or a cyano, an alkyl where at least one of non-adjacent CH ₂ groups is substituted with -O-, - CO-O-, -O-CO-, or -CH=CH-, or combinations thereof, and

[201] R ₁₀₆ is a substituted or unsubstituted alkyl, a substituted or unsubstituted alkylaryl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted pyrimidinyl, a substituted or unsubstituted pyridinyl, a substituted or unsubstituted thiophenyl, a substituted or unsubstituted puranyl, a substituted or unsubstituted naphthyl, or a substituted or unsubstituted phenyl,

[202] where in R ₁₀₆ , the substituted alkyl is an alkyl substituted with a halogen or a cyano, an alkyl where at least one of non-adjacent CH ₂ groups is substituted with -O-, - CO-O-, -O-CO-, or -CH=CH-, or combinations thereof, and

[203] the substituted alkylaryl is an alkylaryl where at least one of non-adjacent CH ₂ groups is substituted with -O-, -CO-O-, -O-CO-, or -CH=CH-.

[204] [Chemical Formula 23]

[206] In the above Chemical Formula 23, [207] R ₁₁₁ is an aromatic diamine group, a diamine group substituted with a substituted or unsubstituted Cl to C24 linear or branched alkylene, or combinations thereof,

[208] where in R ₁₁₁ , the substituted alkylene is a alkylene substituted with a halogen, or a cyano, an alkylene where at least one of non-adjacent CH ₂ groups is substituted with a substituted or unsubstituted arylene, a substituted or unsubstituted heteroarylene, a substituted or unsubstituted cycloalkylene, a substituted or unsubstituted heterocy- cloalkylene, -O-, -CO-, -CO-O-, -O-CO-, -Si(CH ₃ ) ₂ -O-Si(CH ₃ ) ₂ -, -NR'-, -NR'-CO-, - CO-NR'-, -NR'-CO-O-, -0-CO-NR'-, -CH=CH-, -C≡C-, or -0-CO-O- (where R' is hydrogen, or a substituted or unsubstituted Cl to C6 alkyl), or combinations thereof,

[209] R ₁₁₂ is a substituted or unsubstituted Cl to C20 alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl, the n ₁₁₂ is an integer ranging from 0 or 4, and

[210] R ₁₁₃ and R ₁₁₄ are independently hydrogen, a halogen, a cyano, or a substituted or un- substituted Cl to C 12 alkyl,

[211] where in R ₁₁₃ and R ₁₁₄ , the substituted alkyl is an alkyl substituted with a halogen or a cyano, an alkyl where at least one of non-adjacent CH ₂ groups is substituted with -O-, - CO-O-, -O-CO-, or -CH=CH-, or combinations thereof.

[212] (D) Solvent

[213] A liquid crystal photo-alignment agent according to one embodiment includes a solvent.

[214] The solvent may include any one capable of dissolving an epoxy compound and a polymer.

[215] The solvent may include N-methyl-2-pyrrolidone, N,N-dimethyl acetamide,

N,N-dimethyl formamide, dimethyl sulfoxide, γ-butyro lactone, and a phenol-based solvent such as a meta-cresol, a phenol, a halogenated phenol, and the like.

[216] In addition, the solvent may further include a poor solvent such as alcohols, ketones, esters, ethers, hydrocarbons, or halogenated hydrocarbons solvents, as long as the soluble polyimide is not deposited. The poor solvent lowers surface energy of a liquid crystal photo-alignment agent and improves its spread capability and flatness when the liquid crystal photo-alignment agent is coated.

[217] The poor solvent may be included in an amount of 1 to 90 volume% based on the total amount of the solvent. In another embodiment, it may be included in an amount of 1 to 70 volume%.

[218] Examples of the poor solvent include one selected from the group consisting of methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, acetone, methylethylketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl hydroxide, malonic acid ester, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol phenyl ether, ethylene glycol phenyl methyl ether, ethylene glycol phenyl ethyl ether, ethylene glycol dimethylethyl, diethylene glycol dimethylethyl, diethylene glycol ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, 4-hydroxy-4-methyl-2-pentanone, 2-hydroxy ethyl propionate, 2-hydroxy-2-methyl ethyl propionate, ethoxy ethyl acetate, hydroxy ethyl acetate, 2-hydroxy-3-methyl butanoic acid methyl, 3-methoxy methyl propionate, 3-methoxy ethyl propionate, 3-ethoxy ethyl propionate, 3-ethoxy methyl propionate, methyl methoxy butanol, ethyl methoxy butanol, methyl ethoxy butanol, ethyl ethoxy butanol, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichloro butane, trichloro ethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, and combinations thereof. [219] The amount of solvent is not limited in the liquid crystal photo- alignment agent, but according to one embodiment of the present invention, it may be used so that the solid content of the liquid crystal photo- alignment agent may range from 1 to 48 wt%. In another embodiment, the solid content ranges from 3 to 15 wt%; and in a further embodiment, it ranges from 5 to 10 wt%. When the solid is included in the range, it is not influenced by the substrate surface during the printing process, so as to maintain the suitable film uniformity and viscosity, to prevent the uniformity deterioration of layer formed by the printing, and to show suitable transmittance.

[220] (E) Other Additive

[221] The liquid crystal photo- alignment agent according to one embodiment may further include a silane coupling agent or a surfactant.

[222] The liquid crystal photo- alignment film according to another embodiment is fabricated using the liquid crystal photo- alignment agent.

[223] The liquid crystal photo- alignment film may be fabricated by coating the liquid crystal photo-alignment agent on a substrate, and the method of coating the liquid crystal photo-alignment agent on the substrate may include spin coating, flexo printing, InkJet printing, and so on. The film formed by a flexo printing has excellent film uniformity and is easily large-sized, so it is generally used.

[224] The substrate may include any substrate as long as it has a high transparency, and it may include a glass substrate, or a plastic substrate such as an acryl substrate or a polycarbonate substrate. In addition, when it includes a substrate formed with the ITO electrode for driving the liquid crystal, the process may be simplified.

[225] After uniformly coating the liquid crystal photo- alignment agent on a substrate to improve the film uniformity, it may be pre-dried at a temperature of between room temperature and 200 ⁰ C; in another embodiment, at a temperature of between 30 and 15O ⁰ C; and in a further embodiment, at a temperature of between 40 and 12O ⁰ C, for 1 to 100 minutes. Through the pre-drying process, it is possible to provide a uniform film having less deviation by adjusting the volatilization of each component.

[226] Subsequently, it is baked at a temperature of 80 to 300 ⁰ C, or 120 to 28O ⁰ C, for 5 to 300 minutes to completely evaporate the solvent, so it is possible to provide a liquid crystal photo-alignment film.

[227] The obtained liquid crystal photo-alignment film is aligned in one axis with polarization ultraviolet (UV) irradiation, or it is applicable to provide a liquid crystal display (LCD) without subjecting the same with a one axis alignment in some applications such as a vertical alignment layer.

[228] The liquid crystal photo- alignment film according to one embodiment is exposed by light with energy of 10 mJ to 5000 mJ for 0.1 to 180 minutes to align the same in one axis. When it is aligned in one axis while the exposure intensity is decreased as above, the double bond included in the polyimide photopolymer is completely removed. Mode for the Invention

[229] The following examples illustrate the present invention in more detail. These examples, however, should not in any sense be interpreted as limiting the scope of the present invention.

[230] A person having ordinary skill in this art can sufficiently understand parts of the present invention that are not specifically described.

[231] (Preparation Example 1: Preparing Polyamic Acid (PAA-I))

[232] 0.7 moles of paraphenylenediamine and 0.3 moles of functional diamine

3,5-diaminophenyldecyl succinimide represented by the following Chemical Formula 24 are introduced into a four-neck flask mounted with an agitator, a temperature controller, a nitrogen gas injector, and a condenser while nitrogen is passed, and then N-methyl-2-pyrrolidone (NMP) is added to provide a mixed solution.

[233] [Chemical Formula 24]

[234]

H _β

[235] 1.0 mole of solid 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride is severely agitated with the mixed solution. The solid is added in an amount of 20 wt%, and the reaction is carried out at a temperature between 3O ⁰ C and 5O ⁰ C for 10 hours to provide a polyamic acid resin. A mixed organic solvent of N-methyl-2-pyrrolidone and γ- butyrolactone is added to the obtained polyamic acid resin and agitated at room temperature for 24 hours to provide a polyamic acid solution (PAA-I) having a solid content of 8 wt%.

[236] (Preparation Example 2: Preparing Polyimide (SPI-I))

[237] 0.8 moles of phenylenediamine and 0.2 moles of diamine 3,5-diaminophenyldecyl succinimide represented by the following Chemical Formula 24 are introduced into a four-neck flask mounted with an agitator, a temperature controller, a nitrogen gas injector, and a condenser while nitrogen is passed, and then N-methyl-2-pyrrolidone (NMP) is added to provide a mixed solution.

[238] 1.0 mole of solid 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride is severely agitated with the mixed solution. The solid is added in an amount of 20 wt%, and the reaction is carried out with maintaining the temperature between 3O ⁰ C and 5O ⁰ C for 10 hours to provide a polyamic acid resin.

[239] 3.0 moles of acetic acid anhydride and 5.0 moles of pyridine are added to the obtained polyamic acid solution and heated to 8O ⁰ C, and then it is reacted for 6 hours and the catalyst and the solvent are removed through evaporation to provide a soluble polyimide resin having a solid content of 20 wt%.

[240] A mixed organic solvent of N-methyl-2-pyrrolidone and γ-butyrolactone is added to the obtained polyimide resin and agitated at room temperature for 24 hours to provide a polyimide solution (SPI-I) having a solid content of 8 wt%.

[241] (Fabricating Liquid Crystal Photo-aligning Agent) [242] (Example 1) [243] 80 g of a PAA- 1 solution having a solid content of 8 wt% obtained from Preparation Example 1 is added to 20 g of an SPI-I solution having 8 wt% of the solid obtained from Preparation Example 2 to provide a polymer solution. The epoxy compound represented by the following Chemical Formula 25 is added to the polymer solution in an amount of 0.05 parts by weight based on 100 parts by weight of the total polymer, and agitated for 24 hours while nitrogen is passed. Subsequently, it is filtered through a filter having a particle diameter of 0. lμm to provide a liquid crystal photo-alignment agent (hereinafter referred to as PSPI-I) having a solid content of 8 wt%.

[244] [Chemical Formula 25]

[246] (Example 2) [247] A liquid crystal photo-alignment agent (hereinafter referred to as PSPI-2) having a solid content of 8 wt% is prepared in accordance with the same procedure as in Example 1, except that the epoxy compound is added in 30 parts by weight based on 100 parts by weight of the polymer compound.

[248] (Example 3) [249] A liquid crystal photo-alignment agent (hereinafter referred to as PSPI-3) having a solid content of 8 wt% is prepared in accordance with the same procedure as in Example 1, except that the epoxy compound is added in 50 parts by weight based on 100 parts by weight of the polymer compound.

[250] (Example 4) [251] 80 g of a PAA- 1 solution having a solid content of 8 wt% obtained from Preparation Example 1 is added to 20 g of an SPI-I solution having a solid content of 8 wt% obtained from Preparation Example 2 to provide a polymer solution. The epoxy compound represented by the following Chemical Formula 26 is added to the polymer solution in an amount of 0.05 parts by weight based on 100 parts by weight of the total polymer, and agitated for 24 hours while nitrogen is passed. Subsequently, it is filtered through a filter having a particle diameter of 0.1 /M to provide a liquid crystal photo- alignment agent (hereinafter referred to as PSPI-4) having a solid content of 8 wt%.

[252] [Chemical Formula 26]

[254] (Example 5)

[255] A liquid crystal photo-alignment agent (hereinafter referred to as PSPI-5) having a solid content of 8 wt% is prepared in accordance with the same procedure as in Example 4, except that the epoxy compound is added at 30 parts by weight based on 100 parts by weight of the polymer compound.

[256] (Example 6)

[257] A liquid crystal photo-alignment agent (hereinafter referred to as PSPI-6) having a solid content of 8 wt% is prepared in accordance with the same procedure as in Example 4, except that the epoxy compound is added at 50 parts by weight based on 100 parts by weight of the polymer compound.

[258] (Example 7)

[259] 80 g of a PAA- 1 solution having a solid content of 8 wt% obtained from Preparation Example 1 is added to 20 g of an SPI-I solution having a solid content of 8 wt% obtained from Preparation Example 2 to provide a polymer solution. The epoxy compound represented by the following Chemical Formula 27 is added to the polymer solution in an amount of 0.05 parts by weight based on 100 parts by weight of the polymer compound and agitated for 24 hours while nitrogen is passed. Subsequently, it is filtered through a filter having a particle diameter of 0. Iβia to provide a liquid crystal photo- alignment agent (hereinafter referred to as PSPI-7) having a solid content of 8 wt%.

[260] [Chemical Formula 27]

[261]

[262] (Example 8)

[263] A liquid crystal photo-alignment agent (hereinafter referred to as PSPI-8) having a solid content of 8 wt% is prepared in accordance with the same procedure as in Example 7, except that the epoxy compound is added at 30 parts by weight based on 100 parts by weight of the polymer compound.

[264] (Example 9)

[265] A liquid crystal photo-alignment agent (hereinafter referred to as PSPI-9) having a solid content of 8 wt% is prepared in accordance with the same procedure as in Example 7, except that the epoxy compound is added at 50 parts by weight based on 100 parts by weight of the polymer compound.

[266] (Comparative Example 1)

[267] 100 g of a PAA-I solution having a solid content of 8 wt% obtained from

Preparation Example 1 is agitated for 24 hours while nitrogen is passed and filtered through a filter having a particle diameter of 0.1 μm to provide a liquid crystal alignment agent (hereinafter referred to as PSPI-10) having a solid content of 8 wt%.

[268] (Comparative Example 2)

[269] 100 g of an SPI-I solution having a solid content of 8 wt% obtained from Preparation Example 2 is agitated for 24 hours while nitrogen is passed and filtered through a filter having a particle diameter of 0.1 /M to provide a liquid crystal alignment agent (hereinafter referred to as PSPI-11) having a solid content of 8 wt%.

[270] (Comparative Example 3)

[271] 80 g of a PAA- 1 solution having a solid content of 8 wt% obtained from Preparation Example 1 is added to 20 g of an SPI-I solution having a solid content of 8 wt% obtained from Preparation Example 2, agitated for 24 hours while nitrogen is passed, and filtered through a filter having a particle diameter of 0. lμm to provide a liquid crystal alignment agent (hereinafter referred to as PSPI- 12) having a solid content of 8 wt%.

[272] (Assessment of Printabilitv and End Terminal Film Uniformity)

[273] Each liquid crystal photo-alignment agent obtained from Examples 1 to 12 and Comparative Examples 1 to 3 is flexo printed on a glass substrate attached with washed ITO by an alignment layer printer (CZ 200 ^® , manufactured by Nakan Corporation), and the printed substrate is allowed to stand on a hot plate of 50 to 9O ⁰ C for 2 to 5 minutes to pre-dry the coat.

[274] After pre-drying the substrate, the substrate is baked on a hot plate at 200 to 23O ⁰ C for 10 to 30 minutes and exposed to energy of 10 mJ to 5000 mJ for 0.1 to 180 minutes to provide a substrate attached with a liquid crystal photo- alignment film.

[275] The film surface of the liquid crystal photo- alignment film is observed by the naked eye and an electron microscope (MX50 ^® , manufactured by Olympus Corporation) through the entire surface of substrate (central and end terminal parts) to determine printability (pinhole and stains) and film thickness change, and the results are shown in the following Table 1.

[276] In the following Table 1, the printability is determined as good in the case of having 0 to 3 pinholes, moderate in the case of having 4 to 6 pinholes, and bad in the case of having more than 6 pinholes; the stains is determined as good in the case of no strains, and bad in the case of observing stains; and the film uniformity is determined as good in the case of having a thickness deviation of less than 0.005/M, moderate in the case of having a thickness deviation of 0.005 to 0.01/M, and bad in the case of having a thickness deviation of more than 0.01/M.

[277] (Alignment Property of Liquid Crystal Photo- Alignment Film)

[278] A liquid crystal cell is fabricated in order to determine the alignment property of the photo- alignment agent. The liquid crystal cell is fabricated as follows.

[279] A standardized-size ITO glass substrate is patterned by photolithography to provide a square of ITO having a size of 1.5cmx 1.5cm and an ITO electrode shape for applying a voltage and to remove the other parts.

[280] Each liquid crystal photo-alignment agent obtained from Examples 1 to 8 and Comparative Examples 1 to 3 is coated on the patterned ITO substrate by spin coating to provide a thickness of 0.1/M and cured at 7O ⁰ C and 21O ⁰ C.

[281] Two cured ITO substrates are exposed at a predetermined angle and with predetermined energy using an exposer (UIS-S2021J7-YD01, Ushio LPUV) and disposed in a direction opposing each other (for VA mode, 90 degrees), and they are joined while maintaining a cell gas of 4.75/M to correspond to the shapes of the upper and lower ITO substrates. The light source for the exposure is a 2kW deep UV lamp (UXM-2000).

[282] The obtained cell is filled with a liquid crystal material, and the liquid crystal alignment property is observed by a perpendicularly polarized optical microscope. The results are shown in the following Table 1.

[283] (Electro-optical Characteristics of Liquid Crystal Photo-alignment Layer)

[284] The electrical characteristic and optical characteristic of the liquid crystal photo- alignment film are measured with a liquid crystal cell having a cell gap of 4.75/M to determine a voltage-transmission curve, a voltage holding ratio, and a residual DC voltage.

[285] Hereinafter, the electrical and optical characteristics are simply described referring to the voltage-transmission curve, the voltage holding ratio, and the residual DC voltage.

[286] The voltage-transmission curved line is one of important electrical and optical characteristics, and is one factor for determining the driving voltage of a liquid crystal display (LCD). It is a standardized curve of which the quantity of the brightest light is considered to be 100% and the quantity of the darkest light is considered to be 0%.

[287] The voltage holding ratio represents the degree that the exterior electric source and the floating liquid crystal layer hold the charged voltage during an undefined period in an active matrix TFT-LCD, and a value approaching 100% is ideal.

[288] The residual DC voltage represents a voltage applied to the liquid crystal layer by absorbing ionized impurities of the liquid crystal layer to the alignment layer without applying the exterior voltage, and a lower value is better. A method of measuring the residual DC voltage generally includes a method of using flicker and a method of using a curve (C-V) of electrical capacity change of the liquid crystal layer depending upon DC voltage application.

[289] The results of the electrical and optical characteristics of the liquid crystal photo- alignment film using the liquid crystal cell are shown in the following Table 1.

[290]

[Table 1 ]

Referring to Table 1, it is understood that the liquid crystal photo-alignment agents obtained from Examples 1 to 9 show good voltage transmission and voltage holding ratios as well as good printability and film uniformity when the photo-epoxy additive is included at 0.05 to 50 parts by weight based on the amount of liquid crystal photo- alignment agent.

[292] As shown in Table 1, it is understood that the liquid crystal photo-alignment film obtained using each liquid crystal alignment agent obtained from Examples 1 to 9 has superior printability, film uniformity, voltage transmission, or voltage holding ratio to those of Comparative Examples 1 to 3. The liquid crystal photo-alignment film obtained using each liquid crystal photo- alignment agent obtained from Examples 1 to 9 has good electrical characteristics such as voltage transmittance, voltage holding ratio, residual DC voltage, and so on.

[293] The voltage holding ratio and the residual DC voltage are references for determining after-image characteristics of the liquid crystal photo-alignment film, and the afterimage characteristics are more improved as the voltage holding ratio is higher and the residual DC voltage is lower. Accordingly, each liquid crystal photo-alignment agent obtained from Examples 1 to 9 has excellent after-image characteristics compared to those of Comparative Examples 1 to 3.

[294] While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.