JP2010170069A - Curable composition for liquid crystal sealing agent, and liquid crystal display device - Google Patents

Abstract

An object of the present invention is to reduce contamination of liquid crystals, exhibit sufficient curability even in shadowed areas due to wiring, etc., provide sufficient adhesion strength to glass or alignment films, and further improve storage stability. An excellent curable composition for liquid crystal sealants is provided.
The following components (A) to (E):
(A) Compound having ethylenically unsaturated group (B) Aromatic epoxy compound (C) Aliphatic epoxy compound having 3 or more epoxy groups per molecule (D) Epoxy curing agent (E) Photoradical polymerization initiator A curable composition for liquid crystal sealants.
[Selection] Figure 1

Description

  The present invention relates to a radiation curable composition. More specifically, the present invention relates to a radiation curable composition useful as a sealant for liquid crystal display elements and a liquid crystal display element using the same.

  A liquid crystal display element such as a liquid crystal display cell is formed by sealing a liquid crystal between two transparent substrates with electrodes opposed to each other with a predetermined interval. Conventionally, when manufacturing a liquid crystal display cell, first, a liquid crystal injection port is provided on the outer periphery of a range in which liquid crystal is sealed by using a thermosetting sealant by screen printing on one of two transparent substrates with electrodes. Form a pattern. Next, the other transparent substrate is opposed with the spacer interposed therebetween, alignment is performed to bond the two substrates, and the sealant is cured by heating. Next, after injecting liquid crystal from the liquid crystal injection port, the liquid crystal injection port was sealed with a sealing agent. Such a method is generally called a liquid crystal injection method.

  The liquid crystal injection method has many problems such as a large number of processes, low manufacturing efficiency, positional displacement of the substrate due to thermal strain, gap variation, and insufficient adhesion between the sealing agent and the substrate.

  As a means for solving the problems of the liquid crystal injection method, a method called a liquid crystal dropping method has been devised, and a photothermal curing combined method is becoming mainstream for curing the liquid crystal sealant. In such a liquid crystal dropping method, first, a rectangular frame serving as an outer periphery of a range in which liquid crystal is sealed is formed on one of two transparent substrates with electrodes by a liquid crystal sealant by screen printing. At this time, no liquid crystal injection port is provided. Next, with the sealant uncured, liquid crystal is dropped onto the entire surface of the frame, and the other transparent substrate is immediately superimposed and pressure-bonded, and the liquid crystal sealant portion is irradiated with ultraviolet rays and temporarily cured. Thereafter, the liquid crystal cell is manufactured by heating at the time of liquid crystal annealing and further curing the sealant.

  The liquid crystal dropping method can efficiently produce a liquid crystal cell with a small number of processes and is suitable for the production of a large panel. In addition, since temporary curing with ultraviolet rays is performed, displacement of the substrate due to thermal distortion is prevented, and adhesion between the sealing agent and the substrate is improved.

However, in the liquid crystal dropping method, there is a stage where the liquid crystal sealant in an uncured state and the liquid crystal come into contact with each other. There is a problem that a failure occurs (Patent Document 1).
A curable composition in which various components are blended has been proposed for the purpose of reducing the contamination of the liquid crystal due to the components of the uncured liquid crystal sealant and improving the curability (for example, Patent Documents 2 to 7). .

  However, in recent years, there has been a demand for a narrow frame of the liquid crystal display element, and due to the narrow frame, the liquid crystal sealant is often overlapped with the black matrix and the wiring. In this part, since the liquid crystal sealant is not irradiated with ultraviolet rays, an uncured part remains in the sealant, and when this comes into contact with the liquid crystal, the liquid crystal sealant component is eluted and the liquid crystal is contaminated.

  In recent years, an adhesive force to the alignment film is required due to a design change. However, it is required to achieve both an adhesive force to glass and an adhesive force to the alignment film.

JP 2001-133794 A JP 2004-37937 A JP 2003-28004 A JP 2005-263987 A JP 2005-60651 A JP 2006-30482 A JP 2006-58466 A

  The present invention has been made in view of the above-described problems, and reduces the contamination of liquid crystals. Even in a shadowed area due to wiring or the like, sufficient curability and adhesiveness can be obtained, and it corresponds to a narrow frame. It aims at providing the curable composition which can be performed.

  In order to achieve the above-mentioned object, the present inventors have conducted intensive research and developed a (meth) acrylate monomer, a plurality of epoxy compounds having three or more epoxy groups in one molecule, a latent epoxy curing agent, an oxime ester. By using a highly sensitive photo-radical initiator having a structure, it is excellent in workability, has low contamination to liquid crystal, and exhibits good curability and adhesion even in shadowed areas due to wiring etc. The present invention has been completed by finding that a functional composition can be obtained.

That is, the present invention provides the following curable composition, a liquid crystal sealant comprising the same, and a liquid crystal display device using the same.
1. The following components (A) to (E):
(A) Compound having ethylenically unsaturated group (B) Aromatic epoxy compound (C) Aliphatic epoxy compound having 3 or more epoxy groups per molecule (D) Epoxy curing agent (E) Photoradical polymerization initiator A curable composition for liquid crystal sealants.
2. 2. The curable composition for a liquid crystal sealant according to 1 above, wherein the (E) photoradical polymerization initiator contains a compound having an oxime ester structure.
3. 3. The curable composition for liquid crystal sealant according to 2 above, wherein the compound having the oxime ester structure is represented by the following general formula (e-1).

（式中、Ｒ^１は水素原子、フェニル基、炭素数１〜１０のアルキル基を示し、Ｒ^２は水素原子、フェニル基、炭素数１〜１０のアルキル基を示し、Ｒ^３は置換又は非置換のカルバゾール基、或いはＰｈ−Ｓ−Ｐｈｅ−ＣＯ−基（Ｐｈはフェニル基、Ｐｈｅはフェニレン基を示す）を示す。）
４．前記（Ｂ）成分及び前記（Ｃ）成分が、常温、常圧下で液体である、上記１〜３のいずれかに記載の液晶シール剤用硬化性組成物。
５．前記（Ｂ）成分及び前記（Ｃ）成分のエポキシ当量が５０〜２０００である、上記１〜４のいずれかに記載の液晶シール剤用硬化性組成物。
６．前記（Ａ）エチレン性不飽和基を有する化合物が、１個以上の（メタ）アクリロイル基を有する化合物である、上記１〜５のいずれかに記載の液晶シール剤用硬化性組成物。
７．さらに、（Ｆ）無機微粒子を含有する上記１〜６のいずれかに記載の液晶シール剤用硬化性組成物。
８．上記７に記載の液晶シール剤を用いて製造された液晶表示素子。

(In the formula, 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 non-substituted group. A substituted carbazole group or a Ph-S-Phe-CO- group (Ph represents a phenyl group and Phe represents a phenylene group).
4). The curable composition for a liquid crystal sealant according to any one of the above 1 to 3, wherein the component (B) and the component (C) are liquid at normal temperature and normal pressure.
5). The curable composition for liquid crystal sealing agents according to any one of 1 to 4, wherein the epoxy equivalent of the component (B) and the component (C) is 50 to 2000.
6). 6. The curable composition for a liquid crystal sealing agent according to any one of 1 to 5, wherein the compound (A) having an ethylenically unsaturated group is a compound having one or more (meth) acryloyl groups.
7). Furthermore, (F) The curable composition for liquid crystal sealing agents in any one of said 1-6 containing an inorganic fine particle.
8). 8. A liquid crystal display element produced using the liquid crystal sealant according to 7.

ADVANTAGE OF THE INVENTION According to this invention, the curable composition which shows the favorable sclerosis | hardenability and adhesiveness can be provided even if it is a part which is low in the stain | pollution property with respect to a liquid crystal and becomes a shadow by wiring etc.
ADVANTAGE OF THE INVENTION According to this invention, when manufacturing a liquid crystal display element by a liquid crystal dropping method, a particularly useful liquid crystal sealing agent can be provided.
According to the present invention, liquid crystal contamination due to an uncured liquid crystal sealant is reduced, and a liquid crystal display element having excellent long-term stability can be provided.

I. Curable composition The curable composition of this invention (henceforth the composition of this invention) may contain the following component (A)-(I). Among the following components, (A) to (E) are essential components, and (F) to (H) are optional components to be blended as necessary.
(A) Compound having an ethylenically unsaturated group (hereinafter also referred to as component (A))
(B) Aromatic epoxy compound (hereinafter also referred to as component (B))
(C) Aliphatic epoxy compound having 3 or more epoxy groups per molecule (hereinafter also referred to as component (C))
(D) Epoxy curing agent (hereinafter also referred to as component (D))
(E) Photoradical polymerization initiator (hereinafter also referred to as component (E))
(F) Inorganic fine particles (hereinafter also referred to as component (F))
(G) Silane coupling agent (hereinafter also referred to as component (G))
(H) Additive (hereinafter also referred to as component (H))

  The curable composition of the present invention expresses high adhesion to a glass substrate and an alignment film, which has been difficult to achieve at the same time by using two or more types of epoxy compounds, and is free to design a liquid crystal display panel. It increases the degree.

1. Hereinafter, each component will be described.
(A) Compound having an ethylenically unsaturated group The compound having an ethylenically unsaturated group is a component that undergoes radical polymerization, and exhibits effects such as an improvement in strength, a low linear expansion coefficient, and an improvement in positional stability. Although it does not specifically limit as an ethylenically unsaturated group, For example, a (meth) acryloyl group, ethylene group, etc. are mentioned, It is preferable that it is a (meth) acryloyl group.

Examples of the compound having a (meth) acryloyl group include 2-hydroxyethyl acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 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, benzene (Meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, 2,2,2, -Trifluoroethyl (meth) acrylate, 2,2,3,3, -tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H, -octafluoropentyl (meth) acrylate, imide (meth) acrylate, methyl (meta ) Acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethyl Xyl (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, dimethylaminoethyl (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2 -(Meth) acryloyloxyethyl 2-hydroxypropyl phthalate, glycidyl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate, 1,4-butanediol di (meth) acrylate, 1, 3-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9 nonanediol di (meth) acrylate, 1,10 decanediol di (meth) acrylate 2-n-butyl-2 -Ethyl-1,3-propanediol di (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-added bisphenol A di (meth) acrylate, ethylene oxide-added bisphenol A di (meth) acrylate, ethylene oxide-added bisphenol F di (meth) acrylate, dimethylol dicyclopentadiene rudi (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Ethylene oxide modified isocyanuric acid di (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, carbonate diol di (meth) acrylate, polyether diol di (meth) acrylate, polyester diol di (meth) ) Acrylate, polycaprolactone diol di (meth) acrylate, polybutadiene diol di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylol group Pantri (meth) acrylate, propylene oxide-added trimethylolpropane tri (meth) acrylate, ethylene oxide-added trimethylolpropane tri (meth) acrylate, caprolactone-modified trimethylolpropane tri (meth) acrylate, ethylene oxide-added 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-added glycerin tri (meth) Examples thereof include acrylate and tris (meth) acryloyloxyethyl phosphate.
Examples of commercially available compounds having such a (meth) acryloyl group include VR-77LC (manufactured by Showa Polymer Co., Ltd.), EB3700 (manufactured by Daicel Cytec Co., Ltd.), and the like.

  The compounding quantity of the component (A) in the composition of this invention is 0.1-90 mass% when the whole composition is 100 mass%, Preferably it is 1-80 mass%, More preferably, it is 5-70. % By mass. If the blending amount of the component (A) is out of the range of 0.1 to 90% by mass, an appropriate hardness may not be obtained when irradiated with ultraviolet rays, and a positional shift due to heat may easily occur.

(B) an aromatic epoxy compound, (C) an aliphatic epoxy compound having three or more epoxy groups in one molecule,
The component (B) is an aromatic epoxy compound, and the component (C) is an epoxy compound having three or more epoxy groups in one molecule, and is preferably liquid at normal temperature and normal pressure. Here, “liquid at normal temperature and normal pressure” means that the viscosity at normal temperature and normal pressure is 5,000 Pa · s or less, preferably 1,000 Pa · s or less, more preferably 100 Pa · s or less. . Here, “normal temperature” specifically refers to 15 ° C. to 30 ° C., and “normal pressure” specifically refers to atmospheric pressure (0.1 MPa). The viscosity is a measured value using a B-type viscometer at 25 ° C. Since the component (B) and the component (C) are liquid at normal temperature and normal pressure, the liquid crystal sealant using this as a raw material has low viscosity and excellent workability.

  It is preferable that the epoxy equivalent of the epoxy compound of a component (B) and a component (C) exists in the range of 50-2,000, and it is more preferable that it exists in the range of 60-1000. Here, “epoxy equivalent” refers to the molecular weight of the epoxy compound per epoxy group. When the epoxy equivalent is less than 50, there is a possibility that the stain resistance to the liquid crystal is adversely affected. When the epoxy equivalent is more than 2000, sufficient curing strength may not be obtained.

The component (B) is an aromatic epoxy compound, and it is particularly preferable that the epoxy group in one molecule is trifunctional or more, and the effect that the contamination to the liquid crystal is suppressed and the adhesive strength is further improved is obtained. Examples of the component (B) include diaminodiphenylmethane type epoxy compounds, m-cresol type epoxy compounds, bisphenol F type epoxy compounds, phenol novolac type epoxy compounds, and the like. Among these, in particular, N, N, N ′, N′-tetraglycidyl-4,4′-diaminodiphenylmethane, which is a diaminodiphenylmethane type epoxy compound, suppresses contamination of the liquid crystal and further improves the adhesive strength. This is preferable.
Examples of commercially available products of these components (B) include Araldite MY721, DY203 (polyfunctional epoxy compound manufactured by Huntsman Advanced Materials), Epicoat 806, 806L, 807. 152 (made by Japan Epoxy Resin Co., Ltd.) and the like. The epoxy compound of a component (B) may be used individually by 1 type, and may be used in combination of 2 or more type.

The epoxy compound of component (C) is a compound having 3 or more epoxy groups in one molecule, and is not particularly limited as long as it is liquid at normal temperature and normal pressure. For example, sorbitol polyglycidyl ether, Examples include polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether. The component (C) epoxy compound used in the present invention is preferably sorbitol polyglycidyl ether, trimethylolpropane polyglycidyl ether or the like because of low liquid crystal contamination and low viscosity of the compound itself. Since these epoxy compounds have a low viscosity, a liquid crystal sealant made from such an epoxy compound has a low viscosity and excellent workability. Examples of such commercially available epoxy compounds include EX-314, EX-411, EX-614B, EX-610U-P, EX-1610-P (polyfunctional epoxy compound manufactured by Nagase ChemteX Corporation), Examples include GT401 (tetrafunctional epoxy compound manufactured by Daicel Chemical Industries, Ltd.), SR-SEP (polyfunctional epoxy compound manufactured by Sakamoto Pharmaceutical Co., Ltd., etc.).
The epoxy compound of a component (C) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The compounding amount of the component (B) and the component (C) in the composition of the present invention is 0.1 to 90% by mass, preferably 1 to 80% by mass, when the entire composition is 100% by mass. Preferably it is 5-60 mass%. If the blending amount of component (B) is out of the range of 0.1 to 90% by mass, sufficient adhesive strength cannot be obtained, or moderate hardness cannot be obtained when irradiated with ultraviolet rays, resulting in misalignment due to heat. Is likely to occur. Moreover, the compounding ratio of the component (B) and the component (C) is preferably in the range of component (B): component (C) = 10: 90 to 90:10, and more preferably in the range of 20:80 to 80:20. .

(D) Epoxy curing agent The epoxy curing agent is blended in order to crosslink a compound containing an epoxy group and to develop effects of adhesion and hardness. Examples of the epoxy curing agent include an acidic compound, an acid generator, a basic compound, and a base generator. Further, as the epoxy curing agent, it is preferable to use a “latent epoxy curing agent” in which the curing agent itself undergoes a crosslinking reaction with an epoxy group and is incorporated into the crosslinked polymer.
As the latent epoxy curing agent, known ones can be used, but from the viewpoint of providing a one-pack type composition with good viscosity stability, organic acid dihydrazide compounds, imidazole and its derivatives, dicyandiamide, aromatic Amines and the like are preferred. These may be used alone or in combination.

  Among these, the latent epoxy curing agent is preferably an amine-based latent curing agent having a melting point or a softening point temperature according to the ring and ball method (conforming to JISK2207) of 100 to 250 ° C. .

  When an amine-based latent curing agent is used, the active hydrogen of the amine causes a thermal nucleophilic addition reaction to the (meth) acryloyl group of the other component having the (meth) acryloyl group in the composition of the present invention. The curability of the composition of the present invention is improved.

  That is, the amine-based latent curing agent exhibits thermal reaction characteristics for both the component (A) compound having an ethylenically unsaturated group and / or the component (B) and the epoxy compound (C). It functions as a compatibilizing component of both components and is preferable because the panel reliability such as the display characteristics and adhesion reliability of the liquid crystal display panel is improved.

  Specific examples of the latent epoxy curing agent that is an amine latent curing agent and has a melting point or a softening point temperature of 100 to 250 ° C. by the ring and ball method include, for example, dicyandiamide such as dicyandiamide (melting point 209 ° C.) Organic acid dihydrazides such as adipic acid dihydrazide (melting point 181 ° C.), 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 to 147 ° C.), 2-phenyl-4-methylimidazole (melting point 174 to 184 ° C.), 2- Imidazole derivatives such as phenyl-4-methyl-5-hydroxymethylimidazole (melting point: 191 to 195 ° C.) Etc. salicyl hydrazide (melting point 140 ° C.) and the like.

  Moreover, it is also preferable to use the latent epoxy curing agent used in the present invention that has been subjected to a purification treatment by a water washing method, a recrystallization method, or the like.

Examples of commercially available amine-based latent curing agents include Amicure VDH, VDH-J, UDH, UDH-J (Ajinomoto Fine Techno Co., Ltd.), salicyl hydrazide (Otsuka Chemical Co., Ltd.), etc. Is mentioned.
The latent epoxy curing agent may be used alone or in combination of two or more.

  The amount of component (D) in the composition of the present invention is 0.1 to 60% by weight, preferably 1 to 50% by weight, more preferably 3 to 30%, based on 100% by weight of the entire composition. % By mass. If the blending amount of the component (D) is less than 0.1% by mass, the curability with the epoxy is insufficient, and sufficient hardness and adhesiveness may not be obtained, and there is a possibility that the possibility of liquid crystal contamination is increased. is there. On the other hand, when the amount is more than 60% by mass, there is a possibility that an excessive curing agent that does not react with the epoxy may contaminate the liquid crystal.

(E) Photoradical polymerization initiator The photoradical polymerization initiator used in the present invention is added to generate a radical and polymerize the component (A) by ultraviolet irradiation. (E) Although a well-known compound can be used as a component, even if it is a site | part which is highly sensitive and is not directly irradiated with an ultraviolet-ray as a shadow of wiring, a black matrix, etc., reflected light, scattered light, diffraction Since the composition of the present invention can be cured by light, it preferably contains a compound having an oxime ester structure.

  The compound having an oxime ester structure is preferably a compound represented by the following general formula (e-1).

In Formula (e-1), R ¹ is preferably a hydrogen atom, a phenyl group, an alkyl group having 1 to 10 carbon atoms, or the like.
R ² is preferably a hydrogen atom, a phenyl group, an alkyl group having 1 to 10 carbon atoms, or the like.
R ³ is preferably a monovalent organic group containing a substituted or unsubstituted carbazole group, a Ph—S—Phe—CO— group (Ph represents a phenyl group, and Phe represents a phenylene group), and the like.

Moreover, an O-acyl oxime type compound is mentioned as a compound which has an oxime ester structure preferable as a component (E). As the O-acyloxime compound, 9. H. A carbazole-based O-acyloxime polymerization initiator is preferred. For example, 1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], 1- [9-ethyl-6-benzoyl-9. H. -Carbazol-3-yl] -nonane-1,2-nonane-2-oxime-O-benzoate, 1- [9-ethyl-6-benzoyl-9. H. -Carbazol-3-yl] -nonane-1,2-nonane-2-oxime-O-acetate, 1- [9-ethyl-6-benzoyl-9. H. -Carbazol-3-yl] -pentane-1,2-pentane-2-oxime-O-acetate, 1- [9-ethyl-6-benzoyl-9. H. -Carbazol-3-yl] -octane-1-one oxime-O-acetate, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-benzoate, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate, 1- [9-ethyl-6- (1,3,5-trimethylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-benzoate, 1- [9-butyl-6- (2-ethylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-benzoate, 1- [9-ethyl-6- (2-methyl-4-tetrahydropyranylmethoxybenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate, 1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylmethoxybenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate, ethanone, 1- [9-ethyl-6- [2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxy Benzoyl] -9. H. -Carbazol-3-yl]-, 1- (O-acetyloxime) and the like.
Of these O-acyloxime compounds, 1- [9-ethyl-6- (2-methylbenzoyl) -9. H. -Carbazol-3-yl] -ethane-1-one oxime-O-acetate, ethanone, 1- [9-ethyl-6- [2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxy Benzoyl] -9. H. -Carbazol-3-yl]-, 1- (O-acetyloxime), 1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] are preferred.

  Examples of commercially available compounds having an oxime ester structure include Irgacure OX01, OXE02 (manufactured by Ciba Specialty Chemicals Co., Ltd.), N-1919 (manufactured by Adeka Co., Ltd.), and the like.

  The radical photopolymerization initiator of component (E) may be used alone or in combination of two or more. Moreover, you may combine an appropriate sensitizer and a chain transfer agent. What provided the crosslinkable group to photoradical initiator itself can also be used.

  The radical photopolymerization initiator of component (E) is also preferably compounded with a compound having a structure represented by the following general formula (e-2).

式中、Ｒ^２４、Ｒ^２５はそれぞれ独立に炭素数１〜４のアルキル基を表し、Ｒ^２６は水酸基又は炭素数１〜４のアルキル基を表し、Ｒ^２７は水素原子又はメチル基を表す。

In the formula, R ²⁴ and R ²⁵ each independently represents 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.

Furthermore, a structure in which a plurality of (e-2) are continuous may be used, and the molecular weight in that case is preferably in the range of 350 to 10,000.
When the compound represented by (e-2) is used in combination with the radical photopolymerization initiator having the oxime ester structure, the contamination with respect to the liquid crystal can be more effectively reduced. The blending ratio (weight ratio) of the photoradical polymerization initiator having an oxime ester structure and the photoradical initiator represented by (e-2) is preferably in the range of 35:65 to 65:35, and 50 : 50 is particularly preferable. When there are few radical photopolymerization initiators which have an oxime ester structure, dark part curability will fall, and conversely, when too much, the stain resistance with respect to a liquid crystal may fall. If it is in the said range, the curable composition excellent in any performance of adhesiveness, the stain | pollution resistance with respect to a liquid crystal, and dark part curability will be obtained.

Specific examples of the photoradical polymerization initiator represented by (e-2) used in the present invention include oligo (2-hydroxy-2-methyl-1- [4-] represented by the following formula (e-2 ′). (1-methylvinyl) phenyl] propanone is exemplified, and examples of commercially available products include Esacure KIP150 and 150P (manufactured by Sartomer).

（式中、ｋは２〜５０の数を表す。）

(In the formula, k represents a number of 2 to 50.)

  The compounding amount of the component (E) in the composition of the present invention is 0.01 to 20% by mass, preferably 0.1 to 15% by mass, more preferably 0 when the entire composition is 100% by mass. 2 to 10% by mass. If the amount of component (E) is less than 0.01% by mass, the liquid crystal contamination may be deteriorated. On the other hand, when the content is more than 20% by mass, liquid crystal contamination and adhesive strength may be reduced.

(F) Inorganic fine particles By blending inorganic fine particles, a high glass transition temperature and a low linear expansion coefficient are obtained, and the effect of improving dimensional stability can be expressed (improved and improved).
Examples of the inorganic fine particles include particles containing silica, alumina, zirconium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, barium sulfate, talc, montmorillonite and the like as main components, and particles containing silica and alumina as main components are preferable.
The shape of the inorganic fine particles may be any of a spherical shape, a rod shape, a plate shape, a fiber shape, and an indeterminate shape, and these may be a solid shape, a hollow shape, or a porous shape.
The number average particle size of the inorganic fine particles is usually 0.001 to 10 μm, preferably 0.01 to 5 μm. If it exceeds 10 μm, there is a possibility that the gap formation of the glass substrate bonding during the production of the liquid crystal cell will not be successful. Here, the number average particle diameter of the inorganic fine particles is measured by a laser light diffraction method.

  The inorganic fine particles may be directly added to and mixed with other components in powder form, or the solvent dispersion may be added to and mixed with other components to distill off the solvent.

Examples of commercially available inorganic fine particles include, for example, Admafine SO-E1, SO-E2, SO-E3, SO-E4, SO-E5, SE3200-SEJ (manufactured by Admatechs Co., Ltd.), SS01, SS03. , SS15, SS35 (manufactured by Osaka Kasei Co., Ltd.) and the like.
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 a surface treatment, compatibility with other components can be improved, and dispersibility and mechanical strength in the composition can be improved.

  The compounding amount of the component (F) in the composition of the present invention is 1 to 50% by mass, preferably 5 to 40% by mass, more preferably 10 to 30% by mass when the entire composition is 100% by mass. It is. When the blending amount of the component (F) is less than 1% by mass, the dimensional stability may be deteriorated. On the other hand, when the amount is more than 50% by mass, there is a possibility that the gap formation of the glass substrate bonding at the time of manufacturing the liquid crystal cell may not be successful.

(G) Silane coupling agent It is preferably used because the effect of improving the durability of the adhesive strength can be expressed (improvement, improvement) by blending the silane coupling agent.
As the silane coupling agent, those having an epoxy group and those having 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.

Examples of the silane coupling agent having an epoxy group include γ-glycidoxypropyltrimethoxysilane. Examples of commercially available products of these silane coupling agents include SH6040 (manufactured by Toray Dow Corning Co., Ltd.), KBM-403 (manufactured by Shin-Etsu Silicone Co., Ltd.), and the like.
Examples of the silane coupling agent having a (meth) acryloyl group include γ-methacryloxypropyltrimethoxysilane. Examples of commercially available products of these silane coupling agents include SZ6030 (manufactured by Toray Dow Corning Co., Ltd.), KBM-503, KBM-5103 (manufactured by Shin-Etsu Silicone Co., Ltd.), and the like.

  The compounding amount of the component (G) in the composition of the present invention is 0.001 to 15% by mass, preferably 0.01 to 10% by mass, more preferably 0, when the entire composition is 100% by mass. 0.05 to 5% by mass. If the amount of component (G) is less than 0.001% by mass, sufficient adhesion durability may not be obtained. On the other hand, if the amount is more than 15% by mass, the possibility of liquid crystal contamination may increase.

(H) Other additives Other additives can be blended with the composition of the present invention within a range not impairing the effects of the present invention. Examples of such additives include photo radical initiators other than the component (E), sensitizers, chain transfer agents, antifoaming agents, ion scavengers, water absorbing agents, organic fine particles, leveling agents, spacers, organic solvents. Etc.

2. Method for Producing Curable Composition The composition of the present invention uses components (A) to (E) and, if necessary, components (F) to (H) in a container, and a stirrer such as a planetary stirrer. And thoroughly mixed, and then defoamed under vacuum.

3. Curing method and curing conditions of curable composition The composition of the present invention can be cured by ultraviolet irradiation or by heating.
When the composition of the present invention is used as a liquid crystal sealant and a liquid crystal dropping method is used, it is generally hardened by further heating after being temporarily cured by ultraviolet irradiation.
The wavelength of light used for curing the composition of the present invention is not particularly limited, but is preferably 350 to 700 nm in consideration of damage to the alignment film and the liquid crystal. Irradiation dose is preferably 500~10000mJ / cm ^2, more preferably a 1000~3000mJ / cm ^2.
Although it does not specifically limit as temperature of thermosetting, Preferably curing 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 it is 20 minutes or more and less than 3 hours, More preferably, it is 30 minutes or more and less than 2 hours.

II. Liquid crystal sealant The liquid crystal sealant is used to bond the two glass substrates of the liquid crystal display element to protect the inside and prevent the liquid crystal from flowing out.
The liquid-crystal sealing compound of this invention consists of the said curable composition of this invention, It is characterized by the above-mentioned. Therefore, the liquid crystal sealant of the present invention has liquid crystal stain resistance, dark part curability, tensile adhesive strength and the like, and is useful for the production of liquid crystal display elements (liquid crystal display cells) by a liquid crystal dropping method.

  The viscosity of the liquid crystal sealant of the present invention is not particularly limited, but is preferably 10 to 1000 Pa · s, more preferably 100 to 500 Pa · s, from the viewpoint of dispensing properties and shape preservability.

III. Liquid crystal display element The liquid crystal display element of this invention is manufactured using the liquid-crystal sealing compound of the said invention. Therefore, according to the present invention, it is possible to obtain a liquid crystal display element having excellent resistance to liquid crystal contamination and tensile adhesion, and excellent long-term stability and reliability.

The structure of the liquid crystal display element of the present invention will be described with reference to the schematic view of one embodiment of the liquid crystal display element of the present invention shown in FIG.
As shown in FIG. 1, the liquid crystal display element 1 includes a liquid crystal sealant and a liquid crystal 22 with a spacer 18 sandwiched between two glass substrates 10 provided with a transparent electrode 14, an alignment film 12, and a color filter 16. It has a structure to hold.
The two glass substrates 10 are bonded together by the liquid crystal sealing agent 20, and at the same time, the liquid crystal 22 is sealed and held in a space surrounded by the glass substrate 10 and the liquid crystal sealing agent 20. As can be seen from FIG. 1, the liquid crystal sealant 20 is in direct contact with the liquid crystal 22, so that the specific resistance of the liquid crystal 22 is reduced when components in the uncured liquid crystal sealant 20 may be dissolved in the liquid crystal 22. As a result, the long-term stability and reliability of the liquid crystal display element 1 are impaired.
Since the liquid crystal display element of the present invention uses the above-described liquid crystal sealant of the present invention, the uncured liquid crystal sealant component is prevented from dissolving in the liquid crystal, and thus has excellent long-term stability and reliability. Yes.

The liquid crystal display element of the present invention is preferably manufactured by a liquid crystal dropping method. An outline of a manufacturing process of a liquid crystal display element by a liquid crystal dropping method will be described with reference to FIG.
On one glass substrate, a frame of a liquid crystal sealing agent that surrounds a range in which liquid crystal is sealed is formed using a dispenser. The line width and film thickness of the liquid crystal sealing agent are usually about 0.1 to 5 mm and 0.1 to 20 μm, respectively, preferably 0.5 to 3 mm and 1 to 10 μm. Examples of the liquid crystal sealant dispenser used in this case include SHOTminiSL (manufactured by Musashi Engineering Co., Ltd.).
Without curing the liquid crystal sealant, after dropping the liquid crystal into the frame of the liquid crystal sealant and removing bubbles, etc., the other glass substrate is bonded, the two glass substrates are pressure-bonded, and the liquid crystal is sealed To do.
Next, ultraviolet rays are irradiated to temporarily cure the liquid crystal sealant. The ultraviolet rays used at this time are preferably those having a wavelength of 200 to 700 nm, and more preferably those having a wavelength of 350 to 700 nm in consideration of damage to the alignment film and the liquid crystal. As the ultraviolet light source, a high-pressure mercury lamp, a metal halide lamp, an LED, or the like is preferably used.
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 fully cured to obtain liquid crystal. A display element is obtained.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited at all by these Examples.
Production Example 1
Synthesis of urethane acrylate (component (A); glycerin-AOI) 75.4 parts 2-isocyanatoethyl acrylate (Karenz AOI manufactured by Showa Denko KK) in a vessel equipped with a stirrer, 0.1 part dibutyltin dilaurate, 24.6 parts of glycerin (purified glycerin manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) was added dropwise at 10 ° C. for 1 hour, and the mixture was stirred at 60 ° C. for 4 hours. did.
When the amount of residual isocyanate of the product in this reaction liquid was measured by FT-IR, it was 0.1 mass% or less, and it was confirmed that the reaction was carried out almost quantitatively. Moreover, it confirmed that a urethane bond and an acryloyl group (polymerizable unsaturated group) were included in the molecule | numerator.
As a result, 100 parts of glycerin-AOI was obtained.

Example 1
The components shown in Example 1 in Table 1 below were weighed into a container and thoroughly mixed using a planetary stirrer (Awatori Nertaro, manufactured by Shinky Corporation). Thereafter, defoaming was performed under vacuum to produce a curable composition.

Examples 2-4 and Comparative Examples 1-5
Each curable composition was produced in the same manner as in Example 1 except that the composition shown in Table 1 was used.

<Characteristic evaluation of cured product>
The following characteristics were evaluated when the curable compositions obtained in the above Examples and Comparative Examples were cured. The obtained results are shown in Table 1.

1. Tensile bond strength [Glass]
A dispersion in which 1 part by weight of spacer particles is dispersed with respect to 100 parts by weight of the curable composition is taken at the center of the slide glass, and another slide glass is overlapped in a cross shape and pressed to be uniform. Thickness. This was irradiated with ultraviolet rays (500 mW / cm ² , 3000 mJ / cm ² ) and then left at 120 ° C. for 1 hour to obtain a sample for measuring tensile adhesive strength. The adhesive strength (N / mm ² ) of this sample was measured with a tensile tester. If it is 4 N / mm ² or more, the tensile adhesive strength is good.

2. Tensile bond strength [alignment film]
Optomer AL60101 (a composition for alignment film manufactured by JSR Corporation) was applied as an alignment film on a slide glass, prebaked at 80 ° C. for 2 minutes, and then heated in an oven at 200 ° C. for 60 minutes. Except for using a slide glass with an alignment film, The same operation was performed.

3. Change of liquid crystal phase transition temperature 0.025 g of the curable composition was put in a sample bottle (inner diameter 10 mm), and then 0.075 g of liquid crystal (MLC-6608 manufactured by Merck & Co., Inc.) was put. The sample bottle was irradiated with ultraviolet rays (3000 mJ / cm ² ) from the bottom and then left at 120 ° C. for 1 hour. After allowing to cool to 25 ° C, the supernatant of the liquid crystal was taken out and subjected to DSC measurement (temperature increase rate 2 ° C / min). The amount of change was determined from the difference between the measured phase transition temperature and the phase transition temperature of the untreated liquid crystal (blank), and evaluated according to the following evaluation criteria.
A: The difference (change amount) is less than 0.5 ° C. with respect to the blank B: The difference (change amount) with respect to the blank is 0.5 ° C. or more and less than 1.0 C: The difference (change amount) with respect to the blank is 1.0 ℃ or higher

4). Epoxy reaction rate The curable composition before curing and ultraviolet rays were irradiated (light quantity: 500 mW / cm ² , irradiation amount: 3000 mJ / cm ² ), and IR measurement was performed on each of the curable compositions left at 120 ° C. for 1 hour. . Relative to the peak intensity of 1720 cm ^-1, was determined and the reaction rate of the epoxy from the reduction rate of the peak of the epoxy group (910 cm ^-1) intensity. The calculation was performed assuming that the epoxy reaction rate before curing was 0% and the peak intensity of the epoxy group after curing was 0 was 100%. It can be said that the higher the epoxy reaction rate, the better the curability of the curable composition.

5). Storage stability The viscosity (using an E-type viscometer) of the curable composition that was allowed to stand at 23 ° C. for 2 days was measured, and the rate of increase in viscosity was determined by comparison with the viscosity of the initial curable composition.
○: The increase rate is less than 10% with respect to the initial viscosity.
X: The increase rate is 10% or more with respect to the initial viscosity.

6). Dark part sclerosis | hardenability What prepared the light-shielding process (1) for the whole slide glass, and what processed the light-shielding process (2) half. The resin composition is spot-coated on the center of (1), and (2) is bonded together (at this time, the center of the sealant is placed at the boundary between the shielding part and the non-shielding part of (2)). After sufficient compression, after irradiation with ultraviolet rays (3000mJ / cm ^2), to stand for 1 hour at 120 ° C.. Two glass slides were peeled off, IR measurement was performed on the inside of 0.5 mm from the non-shielding part and the shielding part end, the acrylic reaction rate was calculated from the following formula, and evaluated according to the following evaluation criteria.

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

A: Acrylic reaction rate of 0.5 mm from the end of the shielding part is 50% or more B: Acrylic reaction rate of 0.5 mm part from the end of the shielding part is 30% or more and less than 50% C: 0.5 mm from the end of the shielding part The acrylic reaction rate of the part is less than 30%

なお、欄中の「−」は該当する成分を使用しなかったことを表す。

In addition, “-” in the column represents that the corresponding component was not used.

The commercial products in Table 1 represent the following.
(A) component EB3700: Daicel Cytec Co., Ltd. bisphenol A containing epoxy acrylate

Glycerin-AOI (synthesized in Production Example 1)

(B) component Araldite MY721: polyfunctional epoxy resin (molecular weight: 423) manufactured by Huntsman Advanced Materials Co., Ltd.

（Ｃ）成分
ＥＸ−１６１０−Ｐ：ナガセケムテックス（株）製多官能エポキシ化合物（重量平均分子量（ＧＰＣ）：７６０）

Component (C) EX-1610-P: polyfunctional epoxy compound manufactured by Nagase ChemteX Corporation (weight average molecular weight (GPC): 760)

Component (D) Amicure UDH-J: latent epoxy curing agent manufactured by Ajinomoto Fine Techno Co., Ltd. Amicure VDH-J: latent epoxy curing agent manufactured by Ajinomoto Fine Techno Co., Ltd. Hardener

(E) Component (e-1) N-1919: Photo radical polymerization initiator manufactured by Adeka Co., Ltd.

  (E-2) KIP150: Photoradical polymerization initiator manufactured by Sartomer

(F) component Admafine SE3200-SEJ: silica particle (G) component manufactured by Admatechs Corporation SH6040: silane coupling agent manufactured by Toray Dow Corning Co., Ltd .; γ-glycidoxypropyltrimethoxysilane

  From the results of Table 1, it can be seen that in Comparative Examples 1 and 2 where the component (B) and the component (C) are not used in combination, the epoxy reaction rate is low and the tensile adhesive strength is poor. On the other hand, it can be seen that the curable compositions of Examples 1 to 4 in which the epoxy compounds of the component (B) and the component (C) are used together exhibit excellent tensile adhesion strength on both the glass and the alignment film. . Further, it is understood that not only the tensile adhesive strength but also the balance between the liquid crystal phase transition temperature change and dark part curability is excellent.

The liquid crystal sealant of the present invention has high adhesiveness to the substrate because it is sufficiently cured even in the part where the sealant part and the wiring, black matrix, etc. are not directly irradiated with ultraviolet rays due to the recent demand for narrowing the frame. Further, the possibility of liquid crystal contamination due to the uncured liquid crystal sealant component can also be reduced.
ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal sealing agent useful in the liquid crystal dropping system which can manufacture a liquid crystal display element efficiently with few processes can be provided.

It is a cross-sectional schematic diagram of the liquid crystal display element of this invention. It is a figure which shows the outline | summary of the liquid crystal dropping method.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display element 10 Glass substrate 12 Alignment film 14 Transparent electrode 16 Color filter 18 Spacer 20 Liquid crystal sealing agent 22 Liquid crystal

Claims (8)

The following components (A) to (E):
(A) Compound having ethylenically unsaturated group (B) Aromatic epoxy compound (C) Aliphatic epoxy compound having 3 or more epoxy groups per molecule (D) Epoxy curing agent (E) Photoradical polymerization initiator A curable composition for liquid crystal sealants.   The curable composition for a liquid crystal sealant according to claim 1, wherein the (E) radical photopolymerization initiator contains a compound having an oxime structure. The curable composition for liquid crystal sealing agents according to claim 2, wherein the compound having the oxime structure is represented by the following general formula (e-1).

(In the formula, 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 non-substituted group. A substituted carbazole group or a Ph-S-Phe-CO- group (Ph represents a phenyl group and Phe represents a phenylene group).   The curable composition for a liquid crystal sealant according to any one of claims 1 to 3, wherein the component (B) and the component (C) are liquid at normal temperature and normal pressure.   The curable composition for liquid crystal sealing agents according to any one of claims 1 to 4, wherein an epoxy equivalent of the component (B) and the component (C) is in the range of 50 to 2,000.   The curable composition for a liquid crystal sealant according to any one of claims 1 to 5, wherein the compound (A) having an ethylenically unsaturated group is a compound having one or more (meth) acryloyl groups. .   Furthermore, the curable composition for liquid crystal sealing agents of any one of Claims 1-6 containing (F) inorganic fine particles.   The liquid crystal display element manufactured using the liquid-crystal sealing compound of Claim 7.

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