KR100990015B1 - Sealing material for liquid crystal display device, and liquid crystal display device - Google Patents

Abstract

The present invention provides a curable composition capable of reducing contamination to liquid crystals, obtaining sufficient curability and adhesion even in areas shaded by wiring and the like, and coping with narrow solution softening.

This invention is curable composition containing the following components (A)-(D); It relates to a liquid crystal sealing agent and a liquid crystal display element comprising the same.

(A) a compound having an ethylenically unsaturated group,

(B) an epoxy resin having three or more epoxy groups in one molecule and not having a (meth) acryloyl group,

(C) epoxy curing agent,

(D) radical photopolymerization initiator having an oxime ester structure

Ethylenic unsaturated group, epoxy group, epoxy resin, epoxy curing agent, oxime ester structure, radical photopolymerization initiator, curable composition, inorganic fine particles, silane coupling agent, liquid crystal sealant, liquid crystal display device

Description

Sealing agent for liquid crystal display device and liquid crystal display device {SEALING MATERIAL FOR LIQUID CRYSTAL DISPLAY DEVICE, AND LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a curable composition. More specifically, it is related with the curable composition useful as a sealing agent for liquid crystal display elements, and a liquid crystal display element using the same.

Liquid crystal display elements, such as a liquid crystal display cell, are formed by enclosing a liquid crystal between two transparent substrates with electrodes which faced at predetermined intervals. Conventionally, when manufacturing a liquid crystal display cell, first, the pattern which formed the liquid crystal injection hole in the outer periphery of the range which encloses a liquid crystal is formed by screen printing on one side of two transparent substrates with an electrode by screen printing. do. Subsequently, another transparent substrate is opposed to each other with a spacer interposed therebetween, and two substrates are bonded to each other and heated to cure the liquid crystal sealant. Next, after inject | pouring a liquid crystal from a liquid crystal injection hole, the liquid crystal injection hole was sealed with the sealing agent. Such a method is generally called a liquid crystal injection method.

The number of processes for liquid crystal injection is low in manufacturing efficiency, and there are problems such as misalignment of the substrate due to thermal deformation, fluctuation in the gap, and insufficient adhesion between the liquid crystal sealant and the substrate.

As a means of solving the problem of a liquid crystal injection system, the method called a liquid crystal dropping system is currently devised, and the photothermal curing combined use method is mainstream in hardening a liquid crystal sealing agent. Such a liquid crystal dropping system first forms a rectangular frame which becomes the outer periphery of the range which encloses a liquid crystal with a liquid crystal sealing agent by screen printing on one of two transparent substrates with an electrode. At this time, the liquid crystal injection hole is not formed. Next, a liquid crystal is applied dropwise to the whole surface in this frame in the state of non-hardening of a liquid crystal sealing agent, and the other transparent substrate is overlapped and crimped | bonded immediately, and it irradiates ultraviolet-ray to the liquid crystal sealing part part and temporarily hardens. Then, it heats at the time of liquid crystal annealing, and hardens a liquid crystal sealing agent to manufacture a liquid crystal cell.

The liquid crystal dropping method can produce a liquid crystal cell efficiently because there are few processes, and it is suitable also for manufacture of a large panel. Moreover, since temporary hardening by ultraviolet-ray is performed, the position shift of the board | substrate by heat deformation is also prevented, and the adhesiveness of a liquid crystal sealing agent and a board | substrate also improves.

However, in the liquid crystal dropping method, there is a step in which the liquid crystal sealant in the uncured state and the liquid crystal come into contact with each other. Thus, a defect occurs in which the components of the liquid crystal sealant are dissolved in the liquid crystal and contaminate the liquid crystal, thereby lowering the specific resistance of the liquid crystal. There is a problem (Patent Document 1).

The curable composition which mix | blended various components is proposed (for example, following patent documents 2-7) for the purpose of reducing the contaminant with respect to the liquid crystal by the component of an uncured liquid crystal sealing agent, improvement of sclerosis | hardenability, etc.

However, in recent years, narrowing softening of liquid crystal display elements is requested | required, and the liquid-crystal sealing agent overlaps with a black matrix and wiring by the narrowing softening in many cases. In this part, since the ultraviolet light is not irradiated to the liquid crystal sealant, an uncured portion remains in the liquid crystal sealant, which causes a problem that the liquid crystal sealant component elutes and the liquid crystal is contaminated by contact with the liquid crystal.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2001-133794

[Patent Document 2] Japanese Patent Application Laid-Open No. 2004-37937

[Patent Document 3] Japanese Unexamined Patent Publication No. 2003-28004

[Patent Document 4] Japanese Patent Application Laid-Open No. 2005-263987

[Patent Document 5] Japanese Patent Application Laid-Open No. 2005-60651

[Patent Document 6] Japanese Patent Laid-Open No. 2006-30481

[Patent Document 7] Japanese Unexamined Patent Publication No. 2006-58466

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to provide a curable composition capable of reducing contamination to liquid crystals, obtaining sufficient curability and adhesiveness even in areas shaded by wiring, etc., and coping with narrow solution softening. It is done.

MEANS TO SOLVE THE PROBLEM In order to achieve the said objective, the present inventors earnestly researched, The compound which has an ethylenically unsaturated group, The epoxy resin which has three or more epoxy groups in 1 molecule which are liquid under normal temperature and normal pressure, and does not have a (meth) acryloyl group, By using an epoxy curing agent and an optical radical initiator having an oxime ester structure, it is possible to obtain a curable composition having excellent workability, low pollution to liquid crystals, and good curability and adhesion even in a portion shaded by wiring or the like. Discovered and completed the present invention.

That is, this invention provides the following curable composition, the liquid crystal sealing agent containing this, and the liquid crystal display element using the same.

1. Component (A) to (D):

(A) a compound having an ethylenically unsaturated group,

(B) an epoxy resin having three or more epoxy groups in one molecule and not having a (meth) acryloyl group,

(C) epoxy curing agent,

(D) radical photopolymerization initiator having an oxime ester structure

Curable composition containing.

2. The curable composition according to the above 1, wherein the radical photopolymerization initiator having the (D) oxime ester structure is represented by the following general formula (d-1).

Formula (d-1)]

(Wherein R ¹ represents a hydrogen atom, a phenyl group or an alkyl group having 1 to 10 carbon atoms, R ² represents a hydrogen atom, a phenyl group or an alkyl group having 1 to 10 carbon atoms, and R ³ represents a substituted or unsubstituted carba) Or a Ph-S-Ph-CO- group (Ph represents an aromatic group which may have a substituent)

3. Curable composition as described in said 1 or 2 whose epoxy resin which has three or more epoxy groups in the said (B) 1 molecule, and does not have a (meth) acryloyl group is liquid at normal temperature and normal pressure.

4. Curable composition as described in any one of said 1-3 whose epoxy equivalent of the epoxy resin which has 3 or more epoxy groups in said (B) 1 molecule, and does not have a (meth) acryloyl group.

5. The curable composition according to any one of 1 to 4, wherein the compound (A) having an ethylenically unsaturated group is a compound having one or more (meth) acryloyl groups.

6. Curable composition as described in any one of said 1-5 which further contains (E) radical photopolymerization initiator which has a structure represented by following General formula (e-1).

[Formula (e-1)]

(Wherein, R ²⁴ and R ²⁵ each independently represent an alkyl group having 1 to 4 carbon atoms, R ²⁶ represents a hydroxyl group or an alkyl group having 1 to 4 carbon atoms, and R ²⁷ represents a hydrogen atom or a methyl group)

7. The curable composition according to the above 6, wherein the weight ratio of the component (D) and the component (E) is in the range of (D) :( E) = 35: 65 to 65:35.

8. The curable composition according to any one of the above 1 to 7, further comprising (F) inorganic fine particles.

9. Curable composition as described in any one of said 1-8 which further contains (G) silane coupling agent.

10. Liquid crystal sealing agent containing curable composition in any one of said 1-9.

11. The liquid crystal display element manufactured using the liquid crystal sealing agent of said 10.

According to the present invention, it is possible to provide a curable composition which is low in contamination with liquid crystals and exhibits good curability and adhesion even in areas shaded by wiring or the like.

According to this invention, the liquid crystal sealing agent which is especially useful at the time of manufacturing a liquid crystal display element by the liquid crystal dropping method can be provided.

According to the present invention, the contamination of the liquid crystal by the uncured liquid crystal sealant is reduced, so that a liquid crystal display device excellent in long term stability can be provided.

I. Curable Compositions

The curable composition of the present invention (hereinafter referred to as the composition of the present invention) may include the following components (A) to (H). Among the following components, (A) to (D) are essential components, and (E) to (H) are optional components blended as necessary.

(A) a compound having an ethylenically unsaturated group,

(B) an epoxy resin having three or more epoxy groups in one molecule and not having a (meth) acryloyl group,

(C) epoxy curing agent,

(D) radical photopolymerization initiator which has an oxime ester structure,

(E) radical photopolymerization initiator which has a structure represented by general formula (e-1),

(F) inorganic fine particles,

(G) silane coupling agent,

(H) additive

The curable composition of the present invention uses a highly sensitive (D) radical photopolymerization initiator (the radical photopolymerization initiator having an oxime ester structure), so that even a weak ultraviolet scattered light of a shielding site where ultraviolet rays are not directly irradiated by a wiring or a black matrix. Crosslinking reaction of a (meth) acryloyl group advances and can provide high liquid-crystal contamination resistance. Here, "high sensitivity" means that the absorption coefficient of ultraviolet rays is large and can generate radicals even with weak light.

1. Hereinafter, each component is demonstrated.

(A) Compound having ethylenically unsaturated group

The compound which has an ethylenically unsaturated group is a component which radically polymerizes, and expresses effects, such as strength improvement, low linear expansion coefficient, and positional stability improvement. Although it does not specifically limit as ethylenically unsaturated group, For example, a (meth) acryloyl group, an ethylene group, etc. are mentioned, It is preferable that it is a (meth) acryloyl group.

As a compound which has a (meth) acryloyl group, 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl ( Meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isobornyl ( (Meth) acrylate, cyclohexyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, 2-ethoxyethyl (meth) acrylate, tetrahydrofurfuryl ( Meth) acrylate, benzyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, Methoxypoly Tylene glycol (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoro Lopentyl (meth) acrylate, imide (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, propyl (meth) acrylate, n-butyl ( Meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isononyl (meth) acrylate, isomyristyl (meth) acrylate, 2 Butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, bicyclopentenyl (meth) acrylate, isodecyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethyl Aminoethyl (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acrylic Loyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxyethyl 2-hydroxypropylphthalate, glycidyl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate, 1,4-butanediol Di (meth) acrylate, 1,3-butanedioldi (meth) acrylate, 1,6-hexanedioldi (meth) acrylate, 1,9-nonane dioldi (meth) acrylate, 1,10-decane Diol di (meth) acrylate, 2-n-butyl-2-ethyl-1,3-propanedioldi (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate , Polypropylene glycol (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene oxide Addition Bisphenol A Di (meth) acrylate, Ethylene Oxa De-added bisphenol A di (meth) acrylate, ethylene oxide added bisphenol F di (meth) acrylate, dimethyloldicyclopentadienyldi (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, neo Pentyl glycol di (meth) acrylate, ethylene oxide modified isocyanuric acid di (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, carbonatedioldi (meth ) Acrylate, polyetherdioldi (meth) acrylate, polyesterdioldi (meth) acrylate, polycaprolactonedioldi (meth) acrylate, polybutadienedioldi (meth) acrylate, pentaerythritol tree ( Meth) acrylate, trimethylolpropane tri (meth) acrylate, propylene oxide addition trimethylolpropane tri (meth) acrylate, ethylene oxide addition trimethylolprop Pantri (meth) acrylate, caprolactone modified trimethylolpropanetri (meth) acrylate, ethylene oxide addition isocyanuric acid tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol Hexa (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerin tri (meth) acrylate, propylene oxide addition glycerin tri (meth) acrylate, tris ( Meth) acryloyloxyethyl phosphate etc. are mentioned. Among these, the (meth) acrylate compound which has an aromatic ring can be used preferably.

As a commercial item of the compound which has such a (meth) acryloyl group, VR-77LC (made by Showa Kobunshi Co., Ltd.), EB3700 (made by Daicel Cytec Co., Ltd.), etc. are mentioned, for example.

In addition, the urethane (meth) acrylate compound which made the polyol compound react with the compound which has an isocyanate group and a (meth) acryloyl group can also be used.

The compounding quantity of the component (A) in the composition of this invention is 0.1-90 weight%, Preferably 1-80 weight%, More preferably, 5-70 weight%, when the total amount of a composition is 100 weight%. to be. When the compounding quantity of component (A) is out of the said 0.1-90 weight% range, when irradiated with an ultraviolet-ray, an appropriate hardness may not be obtained and position shift by heat may become easy to occur.

(B) An epoxy resin having three or more epoxy groups in one molecule and not having a (meth) acryloyl group

The epoxy resin of component (B) is an epoxy resin which has three or more epoxy groups in 1 molecule, and does not have a (meth) acryloyl group, and it is preferable that it is a liquid at normal temperature and normal pressure. Here, "a liquid at normal temperature and normal pressure" means that the viscosity under normal temperature and normal pressure is 5,000 Pa * s or less, Preferably it is 1,000 Pa * s or less, More preferably, it is 100 Pa * s or less. Here, "normal temperature" means 15 degreeC-30 degreeC specifically, and "normal pressure" means atmospheric pressure (0.1 mPa) specifically. The said viscosity is the measured value using the Brookfield viscometer in 25 degreeC. When component (B) is a liquid at normal temperature and normal pressure, the liquid crystal sealing agent which used this as a raw material becomes low viscosity, and is excellent in workability.

When the epoxy resin of component (B) is trifunctional or more, the contamination with a liquid crystal is suppressed and the effect which adhesive strength improves more is acquired.

The epoxy resin of the component (B) is not particularly limited as long as it has three or more epoxy groups in one molecule and does not have a (meth) acryloyl group and is liquid at normal temperature and normal pressure, for example, sorbitol polyglycidyl ether, Polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, trimethylol propane polyglycidyl ether and the like. As for the epoxy resin of the component (B) used by this invention, sorbitol polyglycidyl ether, trimethylol propane polyglycidyl ether, etc. are preferable at the point which the liquid crystal contamination of resin itself is low, and a viscosity is low. Since these epoxy resins are low viscosity, the liquid crystal sealing agent which uses this as a raw material becomes excellent in workability at low viscosity.

It is preferable that it is in the range of 50-2,000, and, as for the epoxy equivalent of the epoxy resin of component (B), it is more preferable to exist in the range of 60-1,000. Here, "epoxy equivalent" means the molecular weight of the epoxy resin per epoxy group. If the epoxy equivalent is less than 50, there is a fear that it may adversely affect the contamination resistance to the liquid crystal, if larger than 2,000, there is a fear that sufficient curing strength may not be obtained.

As an example of the commercial item of the epoxy resin of a component (B), for example, GT401 (4-functional epoxy resin manufactured by Daicel Chemical Industries, Ltd.), EX-314 (trifunctional epoxy resin manufactured by Nagase Chemtex Co., Ltd.) , EX-411 (4-functional epoxy resin manufactured by Nagase Chemtex Co., Ltd.), EX-614B (4-functional epoxy resin manufactured by Nagase Chemtex Co., Ltd.), EX-610U-P (manufactured by Nagase Chemtex Co., Ltd.) And tetrafunctional epoxy resins), SR-SEP (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), and the like.

The epoxy resin of component (B) may be used individually by 1 type, and may be used in combination of 2 or more type.

The compounding quantity of the component (B) in the composition of this invention is 0.1-90 weight%, Preferably it is 1-80 weight%, More preferably, it is 5-60 weight% when the total amount of a composition is 100 weight%. . When the blending amount of the component (B) is out of the range of 0.1 to 90% by weight, a sufficient adhesive strength may not be obtained, or an appropriate hardness may not be obtained when irradiated with ultraviolet rays, and position misalignment due to heat is likely to occur. There is this.

(C) epoxy curing agent

An epoxy curing agent is mix | blended in order to bridge | crosslink the compound containing an epoxy group, and to express the effect of adhesiveness and hardness. As an epoxy hardening | curing agent, an acidic compound, an acid generator, a basic compound, or a base generator is mentioned. In addition, as an epoxy hardening | curing agent, it is preferable to use the "potential epoxy hardening | curing agent" which the hardening | curing agent itself performs crosslinking reaction with an epoxy group and is accepted in the crosslinked polymer.

As the latent epoxy curing agent, known ones can be used, but organic acid dihydrazide compounds, imidazoles and derivatives thereof, dicyandiamide, aromatic amines, and the like are preferable in that a compound having good viscosity stability in a one-part type can be provided. . These may be used alone or in combination.

Among these, as a latent epoxy hardening | curing agent, it is more preferable that it is an amine latent hardening | curing agent, and the softening point temperature by its melting | fusing point or ring-ball method (based on JISK2207) is 100 degreeC or more.

When the amine latent curing agent is used, the active hydrogen of the amine causes a thermal nucleophilic addition reaction with respect to the (meth) acryloyl group of another component having a (meth) acryloyl group in the composition of the present invention. Curability of the resin is improved.

That is, since the amine latent curing agent exhibits thermal reaction properties with respect to both the compound having an ethylenically unsaturated group of component (A) and / or the epoxy resin of component (B), it functions as a compatibilizing component of both components, thereby Panel reliability, such as display characteristics of a display panel, adhesion | attachment reliability, becomes favorable, and it is preferable.

In addition, although the upper limit of the softening point temperature by melting | fusing point or the round ball method is not specifically limited, Usually, it is 250 degrees C or less.

As a specific example of a latent epoxy hardening | curing agent which is an amine latent hardening | curing agent, and whose melting point or softening point temperature by a ring method is 100 degreeC or more, For example, dicyandiamide, such as dicyanidiamide (melting point 209 degreeC); Organic acid dihydrazides such as adipic dihydrazide (melting point 181 ° C) and 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (melting point 120 ° C); 2,4-diamino-6- [2'-ethylimidazolyl- (1 ')]-ethyltriazine (melting point 215 ° C to 225 ° C), 2-phenylimidazole (melting point 137-147 ° C) , Imidazole derivatives such as 2-phenyl-4-methylimidazole (melting point 174 to 184 ° C), 2-phenyl-4-methyl-5-hydroxymethylimidazole (melting point 191 to 195 ° C), and the like. Can be.

In addition, it is preferable to use the latent epoxy hardening | curing agent used for this invention which performed the high purity treatment by the washing method, the recrystallization method, etc.

As an example of the commercial item of the said amine type latent hardener, amicure VDH, VDH-J, UDH, UDH-J (made by Ajinomoto Fine Techno Co., Ltd.) etc. are mentioned, for example.

A latent epoxy hardening | curing agent may be used individually by 1 type, and may be used in combination of 2 or more type.

The compounding quantity of the component (C) in the composition of this invention is 0.1-60 weight%, Preferably it is 1-50 weight%, More preferably, it is 3-30 weight% when making the total amount of a composition 100 weight%. . When the compounding quantity of component (C) is less than 0.1 weight%, there exists a possibility that liquid-crystal contamination may become high, with the possibility that curability with an epoxy may be inadequate and sufficient hardness and adhesiveness may not be obtained. Moreover, when more than 60 weight%, there exists a possibility that the possibility that an excess hardening agent which does not react with an epoxy may contaminate a liquid crystal may become high.

(D) radical photopolymerization initiator having an oxime ester structure

The radical photopolymerization initiator used in the present invention is a compound having an oxime ester structure. The compound having an oxime ester structure is highly sensitive and can harden the composition of the present invention by reflected light, scattered light, or diffracted light, even in a portion where shadows such as wiring or a black matrix are not directly irradiated with ultraviolet rays.

It is preferable that the compound which has an oxime ester structure is a compound represented by following General formula (d-1).

<Formula (d-1)>

In general formula (d-1), it is preferable that R <^1> is a hydrogen atom, a phenyl group, a C1-C10 alkyl group, etc.

R ² is preferably a hydrogen atom, a phenyl group, or an alkyl group having 1 to 10 carbon atoms.

R ³ is preferably a monovalent organic group including a substituted or unsubstituted carbazole group, or a Ph-S-Ph-CO- group (Ph represents an aromatic group which may have a substituent).

Moreover, O-acyl oxime type compound is mentioned as a compound which has a preferable oxime ester structure as a component (D). As an O-acyl oxime type compound, the carbazole type O-acyl oxime type polymerization initiator is preferable. For example, 1- [9-ethyl-6-benzoylcarbazol-3-yl] -nonane-1,2-nonane-2-oxime-O-benzoate, 1- [9-ethyl-6-benzoylcar Bazol-3-yl] -nonane-1,2-nonane-2-oxime-O-acetate, 1- [9-ethyl-6-benzoylcarbazol-3-yl] -pentane-1,2-pentane- 2-oxime-O-acetate, 1- [9-ethyl-6-benzoylcarbazol-3-yl] -octane-1-one oxime-O-acetate, 1- [9-ethyl-6- (2-methyl Benzoyl) carbazol-3-yl] -ethane-1-one oxime-O-benzoate, 1- [9-ethyl-6- (2-methylbenzoyl) carbazol-3-yl] -ethan-1-one Oxime-O-acetate, 1- [9-ethyl-6- (1,3,5-trimethylbenzoyl) carbazol-3-yl] -ethane-1-one oxime-O-benzoate, 1- [9- Butyl-6- (2-ethylbenzoyl) carbazol-3-yl] -ethane-1-one oxime-O-benzoate, 1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylme Methoxybenzoyl) carbazol-3-yl] -ethane-1-one oxime-O-acetate, 1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylmethoxybenzoyl) carbazole-3- Work〕- Ethane-1-one oxime-O-acetate, 1- [9-ethyl-6- [2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl] carbazole-3 -Yl] -1- (O-acetyl oxime) etc. are mentioned.

Among these O-acyl oxime compounds, in particular, 1- [9-ethyl-6- (2-methylbenzoyl) carbazol-3-yl] -ethane-1-one oxime-O-acetate, 1- [9-ethyl- Preference is given to 6- [2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl] carbazol-3-yl] -1- (O-acetyloxime).

As an example of the commercial item of the compound which has an oxime ester structure, CGI242, OXE01 (made by Ciba Specialty Chemicals Co., Ltd.), N-1919 (made by Adeka Co., Ltd.), etc. are mentioned, for example.

The radical photopolymerization initiator of a component (D) may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, a suitable sensitizer and a chain transfer agent can also be combined. The thing which provided the crosslinkable group to the radical radical initiator itself can also be used.

The compounding quantity of the component (D) in the composition of this invention is 0.01-20 weight%, Preferably it is 0.1-15 weight%, More preferably, 0.2-10 weight weight when making the total amount of a composition 100 weight%. %to be. When the compounding quantity of component (D) is less than 0.01 weight%, the crosslinkability of an acryl group may become inadequate, sufficient hardness and dimensional stability may not be obtained, and there exists a possibility that a liquid-crystal contamination possibility may become high. Moreover, when more than 20 weight%, there exists a possibility that liquid crystal contamination possibility may become high similarly, without hardening to the inside (lower part).

(E) radical photopolymerization initiator having a structure represented by formula (e-1)

The radical photopolymerization initiator of component (E) is a compound which has a structure represented by following General formula (e-1).

<Formula (e-1)>

In the formula, R ²⁴ and R ²⁵ each independently represent an alkyl group having 1 to 4 carbon atoms, R ²⁶ represents a hydroxyl group or an alkyl group having 1 to 4 carbon atoms, and R ²⁷ represents a hydrogen atom or a methyl group.

In addition, the photoinitiator of component (E) may be a structure in which two or more said general formulas (e-1) were connected, and the molecular weight in that case has the preferable range of 350-10,000.

By using together with the radical photopolymerization initiator which has the oxime ester structure of the said component (D), the contamination with respect to a liquid crystal can be reduced more effectively. As for the compounding ratio (weight ratio) of the initiator of component (D) and the initiator of component (E), it is preferable that component (D): component (E) exists in the range of 35: 65-65: 35, and it is 50:50. Particularly preferred. When there is little component (D), dark part sclerosis | hardenability will fall, and when too much, contaminant tolerance to a liquid crystal may fall. If it is in the said range, the curable composition excellent in all the performance of adhesiveness, the contamination tolerance with respect to a liquid crystal, and dark part hardenability will be obtained.

In addition, the photoinitiator of component (E) may be a structure in which two or more said general formulas (e-1) were connected, and the molecular weight in that case has the preferable range of 350-10,000.

By using together with the radical photopolymerization initiator which has the oxime ester structure of the said component (D), the contamination with respect to a liquid crystal can be reduced more effectively. As for the compounding ratio (weight ratio) of the initiator of component (D) and the initiator of component (E), it is preferable that component (D): component (E) exists in the range of 35: 65-65: 35, and it is 50:50. Particularly preferred. When there is little component (D), dark part sclerosis | hardenability will fall, and when too much, contaminant tolerance to a liquid crystal may fall. If it is in the said range, the curable composition excellent in all the performance of adhesiveness, the contamination tolerance with respect to a liquid crystal, and dark part hardenability will be obtained.

As a specific example of the radical photopolymerization initiator of the component (E) used by this invention, oligo (2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl represented by following General formula (e-2). ] Propanone.

<Formula (e-2)>

(Wherein k represents a number from 2 to 50)

As a commercial item of the radical photopolymerization initiator of the component (E) used by this invention, Esacure KIP150 and 150P (above, Sartomer make) are mentioned, for example.

The compounding quantity of the component (E) in the composition of this invention is 0.01-20 weight%, Preferably 0.1-15 weight%, More preferably, 0.2-10 weight%, when the total amount of a composition is 100 weight%. to be. When the compounding quantity of component (E) is less than 0.01 weight%, there exists a possibility that liquid-crystal contamination may deteriorate. Moreover, when more than 20 weight%, there exists a possibility that liquid-crystal contamination and adhesive strength may fall. In addition, the compounding quantity of component (E) should be determined in consideration of the ratio with the compounding quantity of component (D).

(F) inorganic fine particles

By mix | blending an inorganic fine particle, since it becomes a high glass transition temperature and a low linear expansion coefficient, and the effect of dimensional stability improvement can be expressed (improvement, improvement), it is used preferably.

Examples of the inorganic fine particles include particles mainly composed of silica, alumina, zirconium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, barium sulfate, talc, montmorillonite, and the like. Particles mainly containing silica and alumina are preferable.

The shape of an inorganic fine particle may be any of spherical shape, rod shape, plate shape, fibrous form, and indefinite shape, and these may be solid form, hollow form, or porous form.

The number average particle diameter of the inorganic fine particles is usually in the range of 0.001 to 10 µm, preferably 0.01 to 5 µm. When it exceeds 10 micrometers, there exists a possibility that the clearance gap formation of the glass substrate bonding at the time of liquid crystal cell preparation may become difficult. Here, the number average particle diameter of an inorganic fine particle is measured by the laser beam diffraction method.

The inorganic fine particles may be added and mixed with a powdery thing directly to another component, or may be added and mixed with another component which is used as a solvent dispersion liquid to distill off the solvent.

Examples of commercially available products of the inorganic fine particles include, for example, admafine SO-E1, SO-E2, SO-E3, SO-E4, SO-E5 (manufactured by Admattec Co., Ltd.), SS01, SS03, SS15, SS35 (The Osaka Kasei Co., Ltd. product) etc. are mentioned.

An inorganic fine particle may be used individually by 1 type, and may be used in combination of 2 or more type.

The inorganic fine particles may be surface treated with a silane coupling agent or the like. By performing such surface treatment, compatibility with other components can be improved and the dispersibility and mechanical strength in a composition can be improved.

The compounding quantity of the component (F) in the composition of this invention is 1-50 weight%, Preferably it is 5-40 weight%, More preferably, it is 10-30 weight% when making the total amount of a composition 100 weight%. to be. When the compounding quantity of component (F) is less than 1 weight%, there exists a possibility that dimensional stability may deteriorate. Moreover, when more than 50 weight%, there exists a possibility that the clearance gap formation of the glass substrate bonding at the time of liquid crystal cell preparation may not become good.

(G) silane coupling agent

By mix | blending a silane coupling agent, since the effect of the durability improvement of adhesive strength can be expressed (improved, improved), it is used preferably.

As a silane coupling agent, what has an epoxy group and what has a (meth) acryloyl group are preferable.

A silane coupling agent may be used individually by 1 type, and may be used in combination of 2 or more type.

As an example of the silane coupling agent which has an epoxy group, (gamma)-glycidoxy propyl trimethoxysilane etc. are mentioned, for example. As an example of the commercial item of these silane coupling agents, SH6040 (made by Toray Dow Corning Co., Ltd.), KBM-403 (made by Shin-Etsu Silicone Co., Ltd.), etc. are mentioned, for example.

As an example of the silane coupling agent which has a (meth) acryloyl group, (gamma)-methacryloxypropyl trimethoxysilane etc. are mentioned, for example. As an example of the commercial item of these silane coupling agents, SZ6030 (made by Toray Dow Corning Co., Ltd.), KBM-503, KBM-5103 (made by Shin-Etsu Silicone Co., Ltd.), etc. are mentioned, for example.

The compounding quantity of the component (G) in the composition of this invention is 0.001-15 weight%, Preferably it is 0.01-10 weight%, More preferably, 0.05-5 weight% when making the total amount of a composition 100 weight% to be. When the compounding quantity of component (G) is less than 0.001 weight%, there exists a possibility that sufficient adhesive durability may not be obtained. Moreover, when more than 15 weight%, there exists a possibility that liquid crystal contamination possibility may become high.

(H) other additives

The other additive can be mix | blended with the composition of this invention in the range which does not impair the effect of this invention. As such an additive, radical radical initiators, sensitizers, chain transfer agents, antifoamers, ion trapping agents, absorbers, organic fine particles, leveling agents, spacers, organic solvents, etc. other than component (D) and (E) are mentioned, for example. .

2. Manufacturing Method of Curable Composition

In the composition of the present invention, the components (A) to (D) and, if necessary, the components (E) to (H) are placed in a container, sufficiently mixed using a stirrer such as a planetary stirrer, and then defoamed under vacuum. It can manufacture by doing.

3. Curing method and curing conditions of the curable composition

The composition of the present invention can be cured either by ultraviolet irradiation or by heating.

When using the composition of this invention as a liquid crystal sealing agent, and using the liquid crystal dropping method, it is generally hardened by further heating, after temporarily hardening by ultraviolet irradiation.

Although the wavelength of the light used in order to harden the composition of this invention is not specifically limited, 350-700 nm is preferable in consideration of damage to an orientation film or a liquid crystal. The irradiation dose is preferably 500 to 10,000 mJ / cm 2, more preferably 1,000 to 3,000 mJ / cm 2.

Although it does not specifically limit as temperature to thermoset, Preferably, hardening temperature is 70 degreeC or more and less than 200 degreeC, More preferably, it is 100 degreeC or more and less than 150 degreeC. Moreover, as hardening time, Preferably they are 20 minutes or more and less than 3 hours, More preferably, they are 30 minutes or more and less than 2 hours.

II. Liquid crystal sealant

A liquid crystal sealing agent is used in order to adhere | attach two glass substrates of a liquid crystal display element, to protect the inside, and to prevent the outflow of a liquid crystal.

The liquid crystal sealing agent of this invention contains the curable composition of the said invention, It is characterized by the above-mentioned. Therefore, the liquid crystal sealing agent of this invention is equipped with liquid-crystal contamination resistance, dark part curability, tensile adhesive strength, etc., and is useful for manufacture of the liquid crystal display element (liquid crystal display cell) by a liquid crystal dropping method.

Although the viscosity of the liquid crystal sealing agent of this invention is not specifically limited, From a spraying property and shape preservation viewpoint, Preferably it is 10-1,000 Pa.s, More preferably, it is 100-500 Pa.s.

III. Liquid crystal display device

The liquid crystal display element of this invention is manufactured using the liquid crystal sealing agent of the said invention, It is characterized by the above-mentioned. Therefore, according to this invention, the liquid crystal display element which is excellent in liquid-crystal contamination tolerance, tensile adhesive strength, and excellent in long-term stability and reliability is obtained.

The structure of the liquid crystal display element of this invention is demonstrated, referring the schematic diagram of one Embodiment of the liquid crystal display element of this invention shown in FIG.

As shown in FIG. 1, the liquid crystal display device 1 includes a spacer 18 between two glass substrates 10 provided with a transparent electrode 14, an alignment film 12, and a color filter 16. It has a structure which hold | maintains the liquid crystal 22 by the liquid crystal sealing agent.

The liquid crystal sealant 20 bonds two glass substrates 10 together, and seals and holds the liquid crystal 22 in a space surrounded by the glass substrate 10 and the liquid crystal sealant 20. As can be seen from FIG. 1, since the liquid crystal sealant 20 is in direct contact with the liquid crystal 22, if a component in the uncured liquid crystal sealant 20 is dissolved in the liquid crystal 22, the liquid crystal The specific resistance of (22) is lowered, resulting in a loss of long-term stability and reliability of the liquid crystal display element 1.

Since the liquid crystal sealing element of this invention uses the liquid crystal sealing agent of the said invention, since the uncured liquid crystal sealing agent component is prevented from melt | dissolving in a liquid crystal, it is excellent in long-term stability and reliability.

It is preferable that the liquid crystal display element of this invention is manufactured by the liquid crystal dropping method. 2, the outline | summary of the manufacturing process of the liquid crystal display element by a liquid crystal dropping system is demonstrated.

Using an injector on one glass substrate, a frame of a liquid crystal sealant surrounding a range in which liquid crystal is enclosed is formed. The line width and film thickness of a liquid crystal sealing agent are respectively 0.1-5 mm and about 0.1-20 micrometers normally, and it is preferable that they are 0.5-3 mm and 1-10 micrometers, respectively. As an injector of the liquid crystal sealing agent used at this time, SHOTminiSL (made by Musashi Engineering Co., Ltd.) etc. are mentioned.

After hardening a liquid crystal in a frame of a liquid crystal sealing agent and removing a bubble etc., without hardening a liquid crystal sealing agent, the other glass substrate is bonded together, two glass substrates are crimped | bonded, and a liquid crystal is sealed.

Next, ultraviolet rays are irradiated to temporarily harden the liquid crystal sealant. As for the ultraviolet-ray used at this time, it is preferable to use the thing of wavelength 200-700 nm, and considering the damage to an oriented film or a liquid crystal, it is more preferable to use the thing of wavelength 350-700 nm. As a light source of an ultraviolet-ray, it is preferable to use a high pressure mercury lamp, a metal halide lamp, LED, etc.

Thereafter, the substrate is heated at 70 to 200 ° C, preferably 90 to 150 ° C for 10 minutes to 5 hours, preferably 30 minutes to 2 hours to perform liquid crystal annealing, and at the same time, the liquid crystal sealant is completely cured. Obtain a liquid crystal display element.

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited in any way by these Examples.

Preparation Example 1

Synthesis of Urethane Acrylate ((A) Component; Glycerin-AOI)

To a solution containing 75.4 parts of 2-isocyanate ethyl acrylate (Karens AOI manufactured by Showa Denko Co., Ltd.) and 0.1 part of dibutyltin dilaurate in a container with a stirrer, glycerin (Sakamoto Yakuching High School ( 24.6 parts of purified glycerin) produced by the dropwise product was added dropwise under the condition of 10 ° C for 1 hour, and then stirred under the condition of 60 ° C for 4 hours to obtain a reaction solution.

When the amount of residual isocyanate of the product in this reaction liquid was measured by FT-IR, it confirmed that reaction was performed almost quantitatively as 0.1 mass% or less. Moreover, it was confirmed that a urethane bond and acryloyl group (polymerizable unsaturated group) are contained in a molecule | numerator.

As a result, 100 parts of glycerin-AOI were obtained.

Example 1

The component shown in Example 1 of the following Table 1 was weighed in the container, and it fully mixed using the planetary stirrer (Awato Renta Co., Ltd. make). Thereafter, degassing was performed under vacuum to prepare a curable composition.

Examples 2 to 9 and Comparative Examples 1 to 3

Except having set it as the composition shown in following Table 1, it carried out similarly to Example 1, and manufactured each curable composition.

<Characteristic Evaluation of Hardened Materials>

The following characteristics at the time of hardening the curable composition obtained by the said Example and comparative example were evaluated. The obtained results are shown in Table 1.

1. Tensile Adhesive Strength

A curable composition is taken in the center part of a slide glass, another slide glass is overlapped so that it may cross, and it may be crimped | bonded and it will be set to uniform thickness. After irradiating this with ultraviolet (500 mW / cm <2>, 3,000 mJ / cm <2>), it was left to stand at 120 degreeC for 1 hour, and it was set as the sample for tensile adhesive strength measurement. The adhesive strength (N / cm 2) of this sample was measured by a tensile tester. If it is 400 N / cm <2> or more, tensile adhesive strength is favorable.

2. Liquid Crystal Phase Transition Temperature Change

After putting the curable composition 0.025g in the sample bottle (10 mm inside diameter), 0.075g of liquid crystals (MLC-6608 by Merck) was put. After irradiating an ultraviolet-ray (3,000 mJ / cm <2>) from the bottom face of this sample bottle, it was left to stand at 120 degreeC for 1 hour. After cooling to 25 degreeC, the liquid crystal was taken out and DSC measurement was performed (heating rate 2 degree-C / min). The change amount was calculated | required from the difference between the measured phase transition temperature and the phase transition temperature of the unprocessed liquid crystal (public test), and it evaluated according to the following evaluation criteria.

○: The difference (change amount) for the blank test is less than 0.5 ° C.

(Triangle | delta): The difference (amount of change) with respect to a blank test is 0.5 degreeC or more and less than 1.0 degreeC

X: The difference (change amount) with respect to a blank test is 1.0 degreeC or more

3. Dark sclerosis

The light shielding process (1) of the whole surface of a slide glass, and the light shielding process (2) of the half are prepared. The resin composition is spot-coated in the center part of (1), and (2) is bonded together (at this time, the center of a sealing agent will come in the boundary of the shielding part and unshielding part of (2)). After sufficiently compressing, it is irradiated with ultraviolet (3,000 mJ / ㎠), it is left at 120 ℃ 1 hour. Two slide glass was peeled off, IR measurement of the part of 0.5 mm inner part was performed at the non-shielding part and shielding part terminal part, acrylic reaction rate was computed from the following formula, and it evaluated according to the following evaluation criteria.

Acrylic reaction rate = {1- (acrylic group peak area after curing / reference peak area after curing) / (acrylic group peak area before curing / reference peak area before curing)} × 100

(Circle): Acrylic reaction rate of 0.5 mm part in shield part terminal is 50% or more

(Triangle | delta): The acryl reaction rate of the part of 0.5 mm in a shield part terminal is 30% or more and less than 50%

X: Acrylic reaction rate of 0.5 mm of portion at the shield end is less than 30%

The commercial item of Table 1 shows the following.

EB3700: Bisphenol A-containing epoxy acrylate made by Daicel Cytec Co., Ltd.

Glycerin-AOI (synthesized in Preparation Example 1)

HEA: Acrylate made by Osaka Yuki Chemical Co., Ltd.

GT401: tetrafunctional epoxy resin manufactured by Daicel Chemical Industries, Ltd., epoxy equivalent 197

EX-314: Nagase Chemtex Co., Ltd. trifunctional epoxy resin, epoxy equivalent 87

EX-411: 4-functional epoxy resin manufactured by Nagase Chemtex Co., Ltd., epoxy equivalent 90

EX-614B: 4-functional epoxy resin manufactured by Nagase Chemtex Co., Ltd., epoxy equivalent 101

EX-610U-P: 4-functional epoxy resin manufactured by Nagase Chemtex Co., Ltd., epoxy equivalent 216.8

YL980: bifunctional epoxy resin produced by Japan Epoxy Resin Co., Ltd.

Amicure UDH-J: latent epoxy curing agent manufactured by Ajinomoto Fine Techno Co., Ltd.

CGI242: photo radical polymerization initiator manufactured by Ciba Specialty Chemicals Co., Ltd .; Ethane, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime)

N-1919: radical photopolymerization initiator manufactured by Adeka Co., Ltd.

KIP150: Photo radical polymerization initiator produced by Sartomer Co., Ltd.

Admafine SO-E3: Silica Fine Particles by Admatechs Co., Ltd.

SH6040: A silane coupling agent manufactured by Toray Dow Corning Corporation; γ-glycidoxypropyltrimethoxysilane

From the results of Table 1, in Comparative Example 1 in which the component (D) high-sensitivity radical photopolymerization initiator was not used, the dark-curing property was inferior, and in Comparative Example 3 in which the epoxy resin was not used, the tensile adhesive strength was greatly inferior. In Comparative Example 2 using an epoxy resin, the tensile adhesive strength decreased, and the change in liquid crystal phase transition temperature significantly decreased. On the other hand, it can be seen that the curable compositions of Examples 1 to 9 using the component (D) high-sensitivity radical photopolymerization initiator and the epoxy resin of the component (B) exhibit excellent tensile adhesive strength, liquid crystal phase transition temperature change, and dark portion curability. . Moreover, it turns out that it is excellent in the balance of tensile adhesive strength, liquid crystal phase transition temperature change, and dark part sclerosis | hardenability by using together the high molecular weight photoradical initiator of component (E).

The liquid crystal sealant of the present invention is sufficiently cured even in a portion where the sealant portion and the ultraviolet ray overlapped with the wiring and the black matrix are not directly irradiated by a recent request for narrowing solution softening, and thus the adhesion to the substrate is high. The possibility of liquid crystal contamination by the uncured liquid crystal sealant component can also be reduced.

According to this invention, the liquid crystal sealing agent useful in the liquid crystal dropping method which can manufacture a liquid crystal display element with little process number can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram of the liquid crystal display element of this invention.

2 is a diagram illustrating an outline of a liquid crystal dropping method.

<Explanation of symbols for the main parts of the drawings>

1: liquid crystal display element

10: glass substrate

12: alignment film

14: transparent electrode

16: color filter

18: spacer

20 liquid crystal sealant

22: liquid crystal

Claims (11)

The following components (A) to (D): (A) a compound having an ethylenically unsaturated group, (B) an epoxy resin having three or more epoxy groups in one molecule and not having a (meth) acryloyl group, (C) epoxy curing agent, (D) radical photopolymerization initiator having an oxime ester structure Curable composition containing. The curable composition according to claim 1, wherein the radical photopolymerization initiator having the (D) oxime ester structure is represented by the following general formula (d-1). <Formula (d-1)>

Wherein R ¹ represents a hydrogen atom, a phenyl group, or an alkyl group having 1 to 10 carbon atoms, R ² represents a hydrogen atom, a phenyl group, or an alkyl group having 1 to 10 carbon atoms, and R ³ represents a substituted or unsubstituted car A basel group, or a Ph-S-Ph-CO- group (Ph represents an aromatic group which may have a substituent) The curable composition according to claim 1, wherein the epoxy resin having three or more epoxy groups in one molecule of (B) and not having a (meth) acryloyl group is a liquid at normal temperature and normal pressure. The epoxy equivalent of the epoxy resin of any one of Claims 1-3 which has 3 or more epoxy groups in the said (B) 1 molecule, and does not have a (meth) acryloyl group exists in the range of 50-2,000. Curable composition. The curable composition according to any one of claims 1 to 3, wherein the compound (A) having an ethylenically unsaturated group is a compound having at least one (meth) acryloyl group. (E) Curable composition as described in any one of Claims 1-3 which further contains the radical photopolymerization initiator which has a structure represented by following General formula (e-1). <Formula (e-1)>

(Wherein, R ²⁴ and R ²⁵ each independently represent an alkyl group having 1 to 4 carbon atoms, R ²⁶ represents a hydroxyl group or an alkyl group having 1 to 4 carbon atoms, and R ²⁷ represents a hydrogen atom or a methyl group) The curable composition of Claim 6 whose weight ratio of the said component (D) and a component (E) exists in the range of (D) :( E) = 35: 65-65: 35. The curable composition according to any one of claims 1 to 3, further comprising (F) inorganic fine particles. The curable composition according to any one of claims 1 to 3, further comprising (G) a silane coupling agent. The liquid crystal sealing agent containing the curable composition of any one of Claims 1-3. The liquid crystal display element manufactured using the liquid crystal sealing agent of Claim 10.

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