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Title:
CURABLE COMPOSITIONS FOR ONE DROP SEALANT APPLICATIONS
Document Type and Number:
WIPO Patent Application WO/2018/213668
Kind Code:
A1
Abstract:
The present invention relates to resins useful in adhesive and sealant compositions and particularly as one drop fill sealants for liquid crystal applications. In particular, the present invention permits assembly of LCD panels without migration of the sealant resin into the liquid crystal or vice versa during LCD assembly and/or curing of the resin.

Inventors:
SRIDHAR LAXMISHA (US)
Application Number:
PCT/US2018/033331
Publication Date:
November 22, 2018
Filing Date:
May 18, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HENKEL IP & HOLDING GMBH (DE)
SRIDHAR LAXMISHA (US)
International Classes:
C08G73/10; C07D405/14; C08G59/02; C09J163/10; C09J179/08; G02F1/13
Domestic Patent References:
WO2017008242A12017-01-19
WO2017011207A12017-01-19
WO2017008244A12017-01-19
Foreign References:
RU2291876C22007-01-20
Attorney, Agent or Firm:
BAUMAN, Steven C. et al. (US)
Download PDF:
Claims:
What is Claimed is:

1. A resin comprising the structure:

wherein Q may be selected from:

an unfunctionalized group, wherein the unfunctionalized group is selected from the group consisting of H, alkyl, alkoxy, aryl, aralkyl, cycloalkyl and heterocyclic; and

R is a multivalent hydrocarbyl linker selected from linear or branched alkyls, linear or branched cycloalkyls, alkylenes, cycloalkylenes, bicycloalkylenes, tricycloalkylenes, linear or branched alkylenes, linear or branched cycloalkylenes, linear or branched alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene or

heterocycloarylenes; the alkyls, cycloalkyls, alkylenes, cycloalkylenes, alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene and

heterocycloarylenes can optionally contain O or S or hydroxyl group;

Ri is H or methyl;

X is selected from CH2 ,

and n3 are each independently 0-10;

n2is 1-10;

Y is arylene, alkylene, alkenylene, aralkylene, cycloalkylene, bicycloalkylene or tricycloalkylene; and

Z is a covalent bond connecting the aryl group to the carboxylic ester group or a hydrocarbylene linker.

2. A resin com rising the structure:

wherein Xi and X2 are 3-10 membered ring groups independently selected from functionalized or unfunctionalized alicyclic groups optionally having one or more heteroatoms;

R is a multivalent hydrocarbyl linker selected from linear or branched alkyls, linear or branched cycloalkyls, alkylenes, cycloalkylenes, bicycloalkylenes, tricycloalkylenes, linear or branched alkylenes, linear or branched cycloalkylenes, linear or branched alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene or

heterocycloarylenes; the alkyls, cycloalkyls, alkylenes, cycloalkylenes, alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene and

heterocycloarylenes can optionally contain O or S or hydroxyl group; and R is linked to the ring structures containing Xi and X2 at any position; X3 is a bond linking the (meth)acrylate group to the ring Xls or

wherein n is 0-10; and Ri is H or methyl;

Y is arylene, alkylene, alkenylene, aralkylene, cycloalkylene, bicycloalkylene or tricycloalkylene; with the proviso that hydroxyl group on Xi ring is adjacent to the X3 group containing (meth)acrylate, and hydroxyl group on the X2 ring is adjacent to the maleimidoaroyl or maleimidoaralkaoyl group, respectively; and

Z is a covalent bond connecting the aryl group to the carboxylic ester group or a hydrocarbylene linker.

3. A resin comprising the structure:

III

wherein Xi and X2 are 3-10 membered ring groups independently selected from functionalized or unfunctionalized alicyclic groups optionally having one or more heteroatoms;

R is a multivalent hydrocarbyl linker selected from linear or branched alkyls, linear or branched cycloalkyls, alkylenes, cycloalkylenes, bicycloalkylenes, tricycloalkylenes, linear or branched alkylenes, linear or branched cycloalkylenes, linear or branched alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene or

heterocycloarylenes; the alkyls, cycloalkyls, alkylenes, cycloalkylenes, alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes, tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, eterocycloalkylene and heterocycloarylenes can optionally contain O or S or hydroxyl group;

R may be linked to the ring structures Xi and X2 at any position, with the proviso that the hydroxyl group on X2 ring is adjacent to the maleimide containing carboxyl group; and

Z is a covalent bond connecting the aryl group to the carboxylic ester group or a hydrocarbylene linker.

4. An ODF sealant composition comprising the resin of claim 1 and a material selected from the group consisting of photoinitiators, free radical initiators, curing agents, fillers and combinations thereof.

5. The ODF sealant composition of claim 8 further comprising a material selected from the group consisting of photopolymerizable compounds, thermoset resins, thixotropic agents, silane coupling agents, diluents, modifiers, coloring agents, surfactants, preservatives, stabilizers, plasticizers, lubricants, defoamers, leveling agents and combinations thereof.

6. An ODF sealant composition comprising the resin of claim 2 and a material selected from the group consisting of photoinitiators, free radical initiators, curing agents, fillers and combinations thereof.

7. The ODF sealant composition of claim 6 further comprising a material selected from the group consisting of photopolymerizable compounds, thermoset resins, thixotropic agents, silane coupling agents, diluents, modifiers, coloring agents, surfactants, preservatives, stabilizers, plasticizers, lubricants, defoamers, leveling agents and combinations thereof.

8. An ODF sealant composition comprising the resin of claim 3 and a material selected from the group consisting of photoinitiators, free radical initiators, curing agents, fillers and combinations thereof.

9. The ODF sealant composition of claim 8 further comprising a material selected from the group consisting of photopolymerizable compounds, thermoset resins, thixotropic agents, silane coupling agents, diluents, modifiers, coloring agents, surfactants, preservatives, stabilizers, plasticizers, lubricants, defoamers, leveling agents and combinations thereof.

A compound selected from

Description:
CURABLE COMPOSITIONS FOR ONE DROP SEALANT APPLICATIONS

BACKGROUND

FIELD

[0001] The present invention relates to resins useful in adhesive and sealant compositions and particularly as one drop fill sealants for liquid crystal applications. In particular, the present invention permits assembly of LCD panels without migration of the sealant resin into the liquid crystal or vice versa during LCD assembly and/or curing of the resin.

BRIEF DESCRIPTION OF RELATED TECHNOLOGY

[0002] The one drop fill ("ODF") process is becoming the mainstream process in the assembly of LCD panels in display applications, replacing the conventional vacuum injection technology to meet faster manufacturing process demands. In the ODF process, first, a sealant is dispensed on an electrode-equipped substrate to form a frame of a display element, and liquid crystals are dropped inside the depicted frame. In the next step of the assembly, another electrode equipped substrate is joined thereto under vacuum. Then, the sealant undergoes a curing process, either by a combination of UV and thermal or by thermal only process.

[0003] The ODF method has a few problems in that the sealant material in uncured state comes into contact with the liquid crystal ("LC") during the assembly process. This could cause reduction in electro-optical properties of the LC by migration of resin into the LC or vice versa, or ionic impurities. Hence, design of resin systems for sealant material that show good liquid crystal resistance (less contamination) along with good adhesion and moisture barrier properties has remained a challenge.

[0004] In addition, since typically 5% of excess LC is used than what is required to fill the volume, there is positive pressure of LC on the sealant resin during the vacuum assembly process before the sealant undergoes curing. If the resin is not robust, the LC can penetrate into the sealant during the assembly open time. The resin needs structural characteristics to exhibit sufficient LC resistance to minimize LC contamination or penetration. Typically, polar functionalities, such as hydroxyl, urea, urethane, imide and aromatic groups, are needed for good LC resistance. Hence, design of resin systems for sealant material that show good liquid crystal resistance (less contamination) along with good adhesion and moisture barrier properties has remained a challenge.

[0005] While certain solutions to these issues have been identified in the past (see e.g.,

International Patent Application Nos. PCT/US2016/04611, PCT/CN2015/083966 and

PCT/CN2015/083963), alternative technologies would be desirable for the end user to provide wider choices of potential solutions.

SUMMARY

[0006] The present invention relates to unique resins and ODF compositions made therefrom.

[0007] In one aspect of the invention there is included a resin having the structure I:

where Q may be selected from:

and an unfunctionalized group, wherein the unfunctionalized group is selected from the group consisting of H, alkyl, alkoxy, aryl, aralkyl, cycloalkyl and heterocyclic; and

R is a multivalent hydrocarbyl linker selected from linear or branched alkyls, linear or branched cycloalkyls, alkylenes, cycloalkylenes, bicycloalkylenes, tricycloalkylenes, linear or branched alkylenes, linear or branched cycloalkylenes, linear or branched alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene or

heterocycloarylenes; the alkyls, cycloalkyls, alkylenes, cycloalkylenes, alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene and

heterocycloarylenes can optionally contain O or S or hydroxyl group;

Ri is H or methyl;

X is selected from CH 2 ,

and O O

m and n 3 are each independently 0-10;

m is 1-10;

Y is arylene, alkylene, alkenylene, aralkylene, cycloalkylene, bicycloalkylene or tricycloalkylene; and

Z is a covalent bond connecting the aryl group to the carboxylic ester group or a hydrocarbylene linker.

[0008 In another aspect of the invention there is included a resin having the structure II:

where Xi and X 2 are 3-10 membered ring groups independently selected from functionalized or unfunctionalized alicyclic groups optionally having one or more heteroatoms;

R is a multivalent hydrocarbyl linker selected from linear or branched alkyls, linear or branched cycloalkyls, alkylenes, cycloalkylenes, bicycloalkylenes, tricycloalkylenes, linear or branched alkylenes, linear or branched cycloalkylenes, linear or branched alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene or

heterocycloarylenes; the alkyls, cycloalkyls, alkylenes, cycloalkylenes, alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene and

heterocycloarylenes can optionally contain O or S or hydroxyl group; and R is linked to the ring structures containing Xi and X 2 at any position;

X 3 is a bond linkin the (meth)acrylate roup to the ring Xi, or where n is 0-10; and Ri is H or methyl;

Y is arylene, alkylene, alkenylene, aralkylene, cycloalkylene, bicycloalkylene or tricycloalkylene; with the proviso that hydroxyl group on Xi ring is adjacent to the X 3 group containing (meth)acrylate, and hydroxyl group on the X 2 ring is adjacent to the maleimidoaroyl or maleimidoaralkaoyl group, respectively; and

Z is a covalent bond connecting the aryl group to the carboxylic ester group or a hydrocarbylene linker.

In yet another aspect of the invention there is included a resin having the structure III

where X 1 and X 2 are 3-10 membered ring groups independently selected from functionalized or unfunctionalized alicyclic groups optionally having one or more heteroatoms;

R is a multivalent hydrocarbyl linker selected from linear or branched alkyls, linear or branched cycloalkyls, alkylenes, cycloalkylenes, bicycloalkylenes, tricycloalkylenes, linear or branched alkylenes, linear or branched cycloalkylenes, linear or branched alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene or

heterocycloarylenes; the alkyls, cycloalkyls, alkylenes, cycloalkylenes, alkenylenes, arylenes, aralkylenes, arylbicycloalkylenes, aryltricycloalkylenes, bicycloalkylarylenes,

tricycloalkylarylenes, bisphenylenes, cycloalkylarylenes, heterocycloalkylene and

heterocycloarylenes can optionally contain O or S or hydroxyl group; and

R may be linked to the ring structures Xi and X 2 at any position, with the proviso that the hydroxyl group on X 2 ring is adjacent to the maleimide containing carboxyl group; and

Z is a covalent bond connecting the aryl group to the carboxylic ester group or a hydrocarbylene linker.

DETAILED DESCRIPTION

[0010] The resins of the present invention are useful in a wide variety of applications including adhesive and sealant. One particularly effective use of the inventive resins is as an ODF sealants for assembling LCD panels.

[0011] The present invention provides resins (which also includes oligomers and polymers) useful for preparing curable compositions which may be used for ODF sealants. [0012] The glycidyl ether/ester compounds useful in synthesizing the inventive hybrid resins described herein is not particularly limited, and examples of the epoxy compounds available in the market include: bisphenol A type epoxy resins such as Epikote 828EL and Epikote 1004 (all manufactured by Japan Epoxy Resin Co., Ltd.); bisphenol F type epoxy resins such as Epikote 806 and Epikote 4004 (all manufactured by Japan Epoxy Resin Co., Ltd.);

bisphenol S type epoxy resins such as Epiclon EXA1514 (manufactured by Dainippon Ink and Chemicals Inc.) and SE 650 manufactured by Shin A T&C ; 2,2'-diallyl bisphenol A type epoxy resins such as RE-81 ONM (manufactured by Nippon Kayaku Co., Ltd.); hydrogenated bisphenol type epoxy resins such as Epiclon EXA7015 (manufactured by Dainippon Ink and Chemicals Inc.); propyleneoxide-added bisphenol A type epoxy resins such as EP-4000S (manufactured by ADEKA Corporation); resorcinol type epoxy resins such as EX-201

(manufactured by Nagase ChemteX Corporation); biphenyl type epoxy resins such as Epikote YX-4000H (manufactured by Japan Epoxy Resin Co., Ltd.); sulfide type epoxy resins such as YSLV 50TE (manufactured by Tohto Kasei Co., Ltd.); ether type epoxy resins such as YSLV 80DE (manufactured by Tohto Kasei Co., Ltd.); dicyclopentadiene type epoxy resins such as EP- 4088S and EP4088L (manufactured by ADEKA Corporation); naphthalene type epoxy resins such as SE-80, SE-90, manufactured by Shin A T&C; glycidyl amine type epoxy resins such as Epikote 630 (manufactured by Japan Epoxy Resin Co., Ltd.), Epiclon 430 (manufactured by Dainippon Ink and Chemicals Inc.) and TETRAD-X (manufactured by Mitsubishi Gas Chemical Company Inc.); alkylpolyol type epoxy resins such as ZX-1542 (manufactured by Tohto Kasei Co., Ltd.), Epiclon 726 (manufactured by Dainippon Ink and Chemicals Inc.), Epolight 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.) and Denacol EX-611 (manufactured by Nagase ChemteX Corporation); rubber modified type epoxy resins such as YR-450,YR-207 (all manufactured by Tohto Kasei Co., Ltd.) and Epolead PB (manufactured by Daicel Chemical Industries, Ltd.); glycidyl ester compounds such as Denacol EX-147 (manufactured by Nagase ChemteX Corporation); bisphenol A type episulfide resins such as Epikote YL-7000

(manufactured by Japan Epoxy Resin Co., Ltd.); and others such as YDC- 1312, YSLV-BOXY, YSLV-90CR (all manufactured by Tohto Kasei Co., Ltd.), XAC4151 (manufactured by Asahi Kasei Corporation), Epikote 1031, Epikote 1032 (all manufactured by Japan Epoxy Resin Co., Ltd.), EXA-7120 (manufactured by Dainippon Ink and Chemicals Inc.), TEPIC (manufactured by Nissan Chemical Industries, Ltd.). Examples of the commercially available phenol novolak type epoxy compound include Epiclon N-740, N-770, N-775 (all manufactured by Dainippon Ink and Chemicals Inc.), Epikote 152, Epikote 154 (all manufactured by Japan Epoxy Resin Co., Ltd.), and the like. Examples of the commercially available cresol novolak type epoxy compound include Epiclon N-660, N-665, N-670, N-673, N-680, N-695, N-665-EXP and N-672- EXP (all manufactured by Dainippon Ink and Chemicals Inc.); an example of the commercially available biphenyl novolak type epoxy compound is NC-3000P (manufactured by Nippon Kayaku Co., Ltd.); examples of the commercially available trisphenol novolak type epoxy compound include EP1032S50 and EP1032H60 (all manufactured by Japan Epoxy Resin Co., Ltd.); examples of the commercially available dicyclopentadiene novolak type epoxy compound include XD-1000-L (manufactured by Nippon Kayaku Co., Ltd.) and HP-7200 (manufactured by Dainippon Ink and Chemicals Inc.); examples of the commercially available bisphenol A type epoxy compound include Epikote 828, Epikote 834, Epikote 1001, Epikote 1004 (all

manufactured by Japan Epoxy Resin Co., Ltd.), Epiclon 850, Epiclon 860 and Epiclon 4055 (all manufactured by Dainippon Ink and Chemicals Inc.); examples of the commercially available bisphenol F type epoxy compound include Epikote 807 (manufactured by Japan Epoxy Resin Co., Ltd.) and Epiclon 830 (manufactured by Dainippon Ink and Chemicals Inc.); an example of the commercially available 2,2'-diallyl bisphenol A type epoxy compound is RE-810NM

(manufactured by Nippon Kayaku Co., Ltd.); an example of the commercially available hydrogenated bisphenol type epoxy compound is ST-5080 (manufactured by Tohto Kasei Co., Ltd.); examples of the commercially available polyoxypropylene bisphenol A type epoxy compound include EP-4000 and EP-4005 (all manufactured by ADEKA Corporation); and the like. HP4032 and Epiclon EXA-4700 (all manufactured by Dainippon Ink and Chemicals Inc.); phenol novolak type epoxy resins such as Epiclon N-770 (manufactured by Dainippon Ink and Chemicals Inc.); orthocresol novolak type epoxy resins such as Epiclon N-670-EXP-S

(manufactured by Dainippon Ink and Chemicals Inc.); dicyclopentadiene novolak type epoxy resins such as Epiclon HP7200 (manufactured by Dainippon Ink and Chemicals Inc.); biphenyl novolak type epoxy resins such as NC-3000P (manufactured by Nippon Kayaku Co., Ltd.); naphthalene phenol novolak type epoxy resins such as ESN-165S (manufactured by Tohto Kasei Co.) [0013] Examples of the alicyclic epoxy compounds useful in synthesizing the inventive resins include polyglycidyl ethers of polyhydric alcohols having at least one alicyclic ring and cyclohexene oxide- or cyclopentene oxide containing compounds obtained by epoxidizing cyclohexene ring or cyclopentene ring-containing compounds. Specific examples include hydrogenated bisphenol A diglycidyl ether, 3,4-epoxycyclohexylmethyl 3,4- epoxycyclohexanecarboxylate, 3 ,4-epoxy-l-methyl cyclohexyl-3 ,4-epoxy- 1 - methylcyclohexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxy- cyclohexanecarboxylate, 3,4-epoxy-3-methylcyclohexylmethyl 3,4-epoxy-3- methylcyclohexanecarboxylate, 3,4-epoxy-5-methylcylcohexylmethyl-3,4-epoxy-5- methylcyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane- metadioxane, bis(3 ,4-epoxycyclohexylmethyl)adipate, 3 ,4-epoxy-6-methylcyclohexyl carboxylate, methylenebis(3,4-epoxycyclohexane), dicyclopentadiene diepoxide,

ethylenebis(3,4-epoxycyclohexanecarboxylate), dioctylepoxyhexahydrophthalate, and di-2- ethylhexyl epoxyhexahydrophthalate.

[0014] Some of these alicyclic epoxy resins are commercially available under the following trade designations: UVR-6100, UVR-6105, UVR-6110, UVR-6128, and UVR-6200 (products of Union Carbide Corporation); CELLOXIDE 2021, CELLOXIDE 2021P,

CELLOXIDE 2081, CELLOXIDE 2083, CELLOXIDE 2085, CELLOXIDE 2000,

CELLOXIDE 3000, CYCLMER A200, CYCLMER M100, CYCLMER M101, EPOLEAD GT- 301, EPOLEAD GT-302, EPOLEAD 401, EPOLEAD 403, ETHB, and EPOLEADHD 300 (from Daicel Chemical Industries, Ltd.); KRM-21 10, and KRM-2199 (from ADEKA

Corporation).

[0015] In addition to the curable polymers of the present invention, ODF sealant compositions may also include a free radical initiator (which may be triggered by exposure to elevated temperature conditions or radiation in the electromagnetic spectrum) and a curing agent. In embodiments where an epoxide ring is present, a latent epoxy curing agent may also be employed. [0016] Useful thermal free radical initiators include organic peroxides and azo compounds, examples of which include: azo free radical initiators such as AIBN

(azodiisobutyronitrile), 2,2'-azobis(4-methoxy-2,4-dimethyl valeronitrile), 2,2'-azobis(2,4- dimethyl valeronitrile), dimethyl 2,2'-azobis(2-ethylpropionate), 2,2'-azobis(2- methylbutyronitrile), 1,1,1 -azobis(cyclohexane- 1 -carbonitrile), 2,2'-azobis[ -(2-propenyl)-2- methylpropionamide]; dialkyl peroxide free radical initiators such as l,l-di-(butylperoxy-3,3,5- trimethyl cyclohexane); alkyl perester free radical initiators such as TBPEH (t-butyl per-2- ethylhexanoate); diacyl peroxide free radical initiators such as benzoyl peroxide; peroxy dicarbonate radical initiators such as ethyl hexyl percarbonate; ketone peroxide initiators such as methyl ethyl ketone peroxide, bis(t-butyl peroxide) diisopropylbenzene, t-butylperbenzoate, t- butyl peroxy neodecanoate, and combinations thereof.

[0017] Further examples of organic peroxide free radical initiators include dilauroyl peroxide, 2,2-di(4,4-di(tert-butylperoxy)cyclohexyl)propane, di(tert-butylperoxyisopropyl) benzene, di(4-tert-butylcyclohexyl) peroxydicarbonate, dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, 2,3-dimethyl-2,3-diphenylbutane, dicumyl peroxide, dibenzoyl peroxide, diisopropyl peroxydicarbonate, tert-butyl monoperoxymaleate, 2,5-dimethyl-2,5-di(tert- butylperoxy)hexane, tert-butylperoxy 2-ethylhexyl carbonate, tert-amyl peroxy-2- ethylhexanoate, tert-amyl peroxypivalate, tert-amylperoxy 2-ethylhexyl carbonate, 2,5-dimethyl- 2,5-di(2-ethylhexanoylperoxy) hexane 2,5-dimethyl-2,5-di(tert-butylperoxy) hexpe-3, di(3- methoxybutyl)peroxydicarbonate, diisobutyryl peroxide, tert-butyl peroxy-2-ethylhexanoate (TRIGONOX 21 S), 1,1 -di(tert-butylperoxy)cyclohexane, tert-butyl peroxyneodecanoate, tert- butyl peroxypivalate, tert-butyl peroxyneoheptanoate, tert-butyl peroxydiethylacetate, l,l-di(tert- butylperoxy)-3,3,5-trimethylcyclohexane, 3,6,9-triethyl-3,6,9-trimethyl-l,4,7-triperoxonane, di(3,5,5-trimethylhexanoyl) peroxide, tert-butyl peroxy-3,5,5-trimethyl hexanoate, 1,1,3,3- tetramethylbutyl peroxy-2-ethylhexanoate, 1,1,3,3- tetramethylbutyl peroxyneodecanoate, tert- butyl peroxy-3,5,5-trimethyl hexanoate, cumyl peroxyneodecanoate, di-tert-butyl peroxide, tert- butylperoxy isopropyl carbonate, tert-butyl peroxybenzoate, di(2-ethylhexyl) peroxydicarbonate, tert-butyl peroxyacetate, isopropylcumyl hydroperoxide, tert-butyl cumyl peroxide, and combinations thereof. [0018] The thermal free radical initiators with a higher decomposition rate is ordinarily desired, as this can generate free radicals more easily at common cure temperatures (such as in the range of 80 to 130°C) and give faster cure speed, which can reduce the contact time between liquid resin and liquid crystal, and reduce the liquid crystal contamination. On the other hand, if the decomposition rate of initiator is too high, the viscosity stability at room temperature will be influenced and thereby reducing the work life of the sealant.

[0019] A convenient way of expressing the decomposition rate of an initiator at a specified temperature is in terms of its half-life i.e., the time required to decompose one-half of the peroxide originally present. To compare reactivity of different initiators, the temperature at which each initiator has a half-life ("T^") of 10 hours is used. The most reactive (fastest) initiator would be the one with the lowest 10 hour Ίνι temperature.

[0020] In the present invention, the thermal free radical initiator with a 10 hour Tvi temperature of 30 to 80°C is preferred, and with a 10 hour Tyi temperature of 40-70°C is more preferred.

[0021] To balance the reactivity and viscosity stability of the composition, the thermal free radical initiator used in the resin composition is in an amount of usually 0.01 to 3 parts by weight, and preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the inventive resin in the curable composition of the present invention.

[0022] Useful UV free radical initiators include Norrish type I cleavage photoinitiators that are commercially available from CIBA and BASF. These photoinitiators are used in the amount 0.1-5wt%, more preferably in about 0.2 to 3wt% in the formulation.

[0023] Examples of useful epoxy curing agent include but are not limited to the Ajicure series of hardeners available from Ajinomoto Fine-Techno Co., Inc,; the Amicure series of curing agents available from Air products and the JERCURE™ products available from

Mitsubushi Chemical. These curing agents or hardeners or accelerators are used in the amount of about 1% to about 50 % by weight of the total composition, more preferably from about 5% to about 20% by weight of the total composition.

[0024] The curable composition may optionally contain, as desired, a further component capable of a photopolymerization reaction such as a vinyl ether compound. In addition, the curable composition may further comprise additives, resin components and the like to improve or modify properties such as flowability, dispensing or printing property, storage property, curing property and physical property after curing.

[0025] Various additives may be contained in the composition as desired, for example, organic or inorganic fillers, thixotropic agents, silane coupling agents, diluents, modifiers, coloring agents such as pigments and dyes, surfactants, preservatives, stabilizers, plasticizers, lubricants, defoamers, leveling agents and the like; however it is not limited to these. In particular, the composition preferably comprises an additive selected from the group consisting of organic or inorganic filler, a thixotropic agent, and a silane coupling agent. These additives may be present in amounts of about 0.1% to about 50% by weight of the total composition, more preferably from about 2% to about 10% by weight of the total composition.

[0026] The filler may include inorganic fillers such as silica, diatomaceous earth, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, barium sulphate, gypsum, calcium silicate, talc, glass bead, sericite activated white earth, bentonite, aluminum nitride, silicon nitride, and the like; meanwhile, organic fillers such as poly(methyl) methacrylate, poly(ethyl) methacrylate, poly(propyl) methacrylate, poly(butyl) methacrylate, butylacrylate-methacrylic acid-(mefhyl) methacrylate copolymer, polyacrylonitrile, polystyrene, polybutadiene, polypentadiene, polyisoprene, polyisopropylene, and the like. These may be used alone or in combination. These fillers may be present in amounts of about 1% to about 80%, more preferably from about 5% to about 30% by weight of the total composition.

[0027] The thixotropic agent may include, but is not limited to, talc, fume silica, superfine surface-treated calcium carbonate, fine particle alumina, plate-like alumina; layered compounds such as montmoriUonite, spicular compounds such as aluminum borate whisker, and the like. Among them, talc, fume silica and fine alumina are particularly desired. These agents may be present in amounts of about 1% to about 50%, more preferably from about 1% to about 30% by weight of the total composition.

[0028] The silane coupling agent may include, but is not limited to, γ- aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ- methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxylsilane, and the like.

[0029] The curable composition according to the present invention may be obtained by mixing the aforementioned each component by means of, for example, a mixer such as a stirrer having stirring blades and a three roll mill. The composition is liquid at ambient with the viscosity of 200-400 Pa.s (at 25°C) at 1.5s-l shear rate.

[0030] The present invention also relates to a method for manufacturing a liquid crystal display having a liquid crystal layer between a first substrate and a second substrate, by means of a liquid crystal one-drop-filling process. The method comprises the steps of:

(a) applying the curable composition described in the present invention on a sealing region at periphery of a surface of the first substrate;

(b) dropping liquid crystal on a central area encircled by the sealing region of the surface of the first substrate;

(c) overlaying the second substrate on the first substrate;

(d) performing partial curing by UV-irradiating the curable composition, and

(e) performing final curing by heating the curable composition.

[0031] The first substrate and the second substrate used in the present invention are usually transparent glass substrates. Generally, transparent electrodes, active matrix elements (such as TFT), alignment film(s), a color filter and the like are formed on at least one of the opposed faces of the two substrates. These constitutions may be modified according to the type of the LCD. The manufacturing method according to the present invention may be thought to be applied for any type of the LCD. [0032] In the step (a), the curable composition is applied on the periphery portion of the surface of the first substrate so as to lap around the substrate circumference in a frame shape. The portion where the curable composition is applied in a frame shape is referred as a seal region. The curable composition can be applied by a known method such as screen printing and dispensing.

[0033] In the step (b), the liquid crystal is then dropped onto the center region surrounded by the seal region in the frame shape on the surface of the first substrate. This step is preferably conducted under reduced pressure.

[0034] In the step (c), said second substrate is then placed over said first substrate, and

UV-irradiated in the step (d). By the UV-irradiation, the curable composition cures partially and shows the strength at a level that displacement does not occur by handling, whereby the two substrates are temporally fixed. Generally, the radiation time is preferably short, for example not longer than 5 minutes, preferably not longer than 3 minutes, more preferably not longer than 1 minute.

[0035] In the step (e), heating the curable composition allows it to achieve the final curing strength, whereby the two substrates are finally bonded. The thermal curing in the step (e) is generally heated at a temperature of 80 to 130°C, and preferably of 100 to 120°C, with the heating time of 30 minutes to 3 hours, typically 1 hour.

[0036] By the aforementioned process, the major part of the LCD panel is completed.

EXAMPLES

Example 1:

[0037] To a 500mL 3 necked flask equipped with a magnetic stir bar were added N,N- diglycidyl-4-glycidyloxyaniline (24.18g, 87mmol), 6-maleimidocaproic acid (18.42g, 87mmol), Hycat 2000S (340mg, 0.8wt%) and methylhydroquinone (42mg, lOOOppm) in ethyl acetate (42mL). The mixture was stirred at 65°C for 4h. After cooling, 300mL of ethyl acetate was added and the organic layer washed once with aq. NaHC0 3 solution, once with 5% aq. NaOH solution and 3 times with deionized water. After drying over anhydrous Na 2 S0 4 , the solution was stirred with 5g (10 wt %) silica and 5g of sillitin for lh. The solution was filtered off and washed with lOOmL of ethyl acetate. 70mg of methylhydroquinone was added (total 2000ppm) and the solvent evaporated to yield a resin as a liquid (35g, 83%). ¾ NMR indicated the presence of a mixture of the N-glycidyl and O-glycidyl adducts of maleimidocaproic acid.