JP2010053330A - Curable composition, liquid crystal sealing agent and liquid crystal display element - Google Patents

Abstract

[PROBLEMS] To solve the problem of liquid crystal contamination due to an uncured liquid crystal sealant component, which is sufficiently cured even in a portion not directly irradiated with ultraviolet rays overlapping with wiring, black matrix, etc. due to a request for narrowing the frame. And a liquid crystal display element with excellent long-term stability.
The following components (A) to (E):
(A) (Meth) acrylate compound (B) Epoxy curing agent (C) Photoradical polymerization initiator having an oxime ester structure (D) Epoxy compound (E) A curable composition containing organic particles.
[Selection] Figure 1

Description

  The present invention relates to a curable composition. More specifically, the present invention relates to a 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 alignment is performed with the other transparent substrate facing each other with the spacer interposed therebetween, the two substrates are bonded together, and heated to cure the liquid crystal sealant. 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 liquid crystal sealant 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, liquid crystal is dropped onto the entire surface of the frame in an uncured state, 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. After that, the liquid crystal cell is manufactured by heating at the time of liquid crystal annealing and further curing the liquid crystal 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 strain is prevented, and adhesion between the liquid crystal sealant 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 liquid crystal sealant, and when this comes into contact with the liquid crystal, the liquid crystal sealant component is eluted and the liquid crystal is contaminated. .

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, reduces the contamination of the liquid crystal, and provides sufficient curability even in a shadowed portion due to wiring or the like, and curability that can cope with narrowing of the frame. An object is to provide a composition.

  In order to achieve the above object, the present inventors have intensively studied and used a (meth) acrylate compound, an epoxy curing agent, a highly sensitive photoradical initiator having an oxime ester structure, an epoxy compound, and organic resin particles. Thus, the present inventors have found that a curable composition having high adhesive strength that exhibits low curability with respect to liquid crystal and exhibits good curability even in a portion shaded by wiring or the like 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) (Meth) acrylate compound (B) Epoxy curing agent (C) Photoradical polymerization initiator having an oxime ester structure (D) Epoxy compound (E) A curable composition containing organic particles.
2. 2. The curable composition according to 1 above, wherein the radical photopolymerization initiator (C) having an oxime ester structure is represented by the following general formula (c-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、置換又は非置換フェニル基、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−Ｐｈ−ＣＯ−基（Ｐｈはフェニル基を示す）を示す。）
３．（Ｄ）エポキシ化合物が、分子中に２個以上のエポキシ基を有する化合物を含有する上記１又は２に記載の硬化性組成物。
４．（Ｅ）有機粒子がアクリル樹脂粒子である１〜３のいずれかに記載の硬化性組成物。５．さらに、（Ｆ）無機微粒子を含有する上記１〜４のいずれかに記載の硬化性組成物。６．さらに、（Ｇ）シランカップリング剤を含有する上記１〜５のいずれかに記載の硬化性組成物。
７．上記１〜６のいずれかに記載の硬化性組成物からなる液晶シール剤。
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 substituted or unsubstituted phenyl group, or an alkyl group having 1 to 10 carbon atoms; R ³ Represents a substituted or unsubstituted carbazole group or a Ph-S-Ph-CO- group (Ph represents a phenyl group).
3. (D) The curable composition according to 1 or 2 above, wherein the epoxy compound contains a compound having two or more epoxy groups in the molecule.
4). (E) The curable composition according to any one of 1 to 3, wherein the organic particles are acrylic resin particles. 5). Furthermore, (F) The curable composition in any one of said 1-4 containing an inorganic fine particle. 6). Furthermore, (G) The curable composition in any one of said 1-5 containing a silane coupling agent.
7). The liquid-crystal sealing compound which consists of a curable composition in any one of said 1-6.
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 sclerosing | hardenable property which shows the favorable sclerosis | hardenability 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.

I. Curable composition The curable composition of this invention (henceforth the composition of this invention) may contain the following component (A)-(H). Among the following components, (A) to (E) are essential components, and (F) to (H) are optional components to be blended as necessary.
(A) (meth) acrylate compound (B) epoxy curing agent (C) photo radical polymerization initiator having an oxime ester structure (D) epoxy compound (E) organic particles (F) inorganic fine particles (G) silane coupling agent ( H) Other ingredients

  The curable composition of the present invention uses a highly sensitive (C) photoradical polymerization initiator (photoradical polymerization initiator having an oxime ester structure), so that a shielding site that is not directly irradiated with ultraviolet rays by a wiring or a black matrix is used. Even in the case of weak ultraviolet scattered light, the crosslinking reaction of the (meth) acryloyl group proceeds, and high liquid crystal stain resistance can be imparted. Here, “high sensitivity” means that the absorption coefficient of ultraviolet rays is large and radicals can be generated even with weak light.

1. Hereinafter, each component will be described.
(A) Compound having (meth) acryloyl group The compound having (meth) acryloyl group is a component that undergoes radical polymerization.

Examples of the compound having a (meth) acryloyl group include 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 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, methoxy Ethylene glycol (meth) acrylate, 2-ethoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (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 (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 ( 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-propane Diol 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 Xoxide-added bisphenol F di (meth) acrylate, dimethylol dicyclopentadiene di (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, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, propylene oxide-added trimethylol Propane 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 ( Examples include meth) acrylate, propylene oxide-added glycerin tri (meth) acrylate, and tris (meth) acryloyloxyethyl phosphate. Of these, (meth) acrylate compounds having an aromatic ring can be preferably used.
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.
In addition, a urethane (meth) acrylate compound obtained by reacting a polyol compound with a compound having an isocyanate group and a (meth) acryloyl group can also be used.

  The amount of component (A) in the composition of the present invention is preferably 0.1 to 90% by mass, more preferably 1 to 80% by mass, particularly preferably 100% by mass when the entire composition is 100% by mass. 5 to 60% 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) 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.

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

  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 with respect to both the (meth) acrylate compound of component (A) and / or the epoxy compound of component (D), and thus functions as a compatibilizing component for both components. In addition, the panel reliability such as the display characteristics and adhesion reliability of the liquid crystal display panel is improved, which is preferable.

The upper limit of the melting point or the softening point temperature by the ring and ball method is not particularly limited, but is usually 250 ° C. or lower.
Specific examples of the latent epoxy curing agent which is an amine-based latent curing agent and has a melting point or a softening point temperature by the ring and ball method of 100 ° C. or higher include, for example, dicyandiamides 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′-ethyl; Imidazolyl- (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-phenyl Examples include imidazole derivatives such as -4-methyl-5-hydroxymethylimidazole (melting point: 191 to 195 ° C). It is.

  In addition, the latent epoxy curing agent used in the present invention is preferably one that has been subjected to a high-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 (manufactured by Ajinomoto Fine Techno Co., Ltd.) and the like.
The latent epoxy curing agent may be used alone or in combination of two or more.

  The compounding amount of the component (B) in the composition of the present invention is 0.1 to 60% by mass, preferably 1 to 50% by mass, more preferably 5 when the solid content of the composition is 100% by mass. -30 mass%. If the blending amount of the component (B) is less than 0.1% by mass, the curability with the epoxy is insufficient, and sufficient hardness and adhesiveness may not be obtained. is there. On the other hand, if the amount is more than 60% by mass, an excessive curing agent that does not react with epoxy may increase the possibility of liquid crystal contamination.

(C) Photoradical polymerization initiator having an oxime ester structure The photoradical polymerization initiator used in the present invention is a compound having an oxime ester structure. A compound having an oxime ester structure is highly sensitive and cures the composition of the present invention by reflected light, scattered light, or diffracted light even in a region such as a wiring or black matrix that is not directly irradiated with ultraviolet rays. Can be made.

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

In Formula (c-1), R ¹ is preferably a hydrogen atom, a phenyl group, or an alkyl group having 1 to 10 carbon atoms.
R ² is preferably a hydrogen atom, a substituted or unsubstituted phenyl group, or an alkyl group having 1 to 10 carbon atoms.
R ³ is preferably a monovalent organic group containing a substituted or unsubstituted carbazole group, a Ph—S—Ph—CO— group (Ph represents a phenyl group or 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 (C). As the O-acyloxime compound, a carbazole-based O-acyloxime 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-benzoylcarbazole-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-methylbenzoyl) carbazol-3-yl] -Ethan-1-one oxime-O-benzoate, 1- [9-ethyl-6- (2-methylbenzoyl) carbazol-3-yl] -ethane-1-one oxime- -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-tetrahydropyranylmethoxybenzoyl) carbazol-3-yl ] -Ethane-1-one oxime-O-acetate, 1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylmethoxybenzoyl) carbazol-3-yl] -ethane-1-one oxime-O-acetate, Examples include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] and the like.

  As preferred specific examples, the following compound Nos. 1-No. And compounds represented by each of 4.

  Among these O-acyloxime compounds, in particular 1- [9-ethyl-6- (2-methylbenzoyl) carbazol-3-yl] -ethane-1-one oxime-O-acetate, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], compound no. 1, compound no. 3 is preferred.

  Examples of commercially available compounds having an oxime ester structure include Irgacure OXE01, Irgacure OXE02 (manufactured by Ciba Specialty Chemicals Co., Ltd.), and the like.

  The radical photopolymerization initiator of component (C) 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 compounding quantity of the component (C) in the composition of this invention is 0.01-20 mass% when the whole composition is 100 mass%, Preferably it is 0.1-15 mass%, More preferably, it is 1 -10 mass%. If the amount of component (C) is less than 0.01% by mass, the crosslinkability of the acrylic group may be insufficient, and sufficient hardness and dimensional stability may not be obtained, and the possibility of liquid crystal contamination may increase. is there. On the other hand, if the amount is more than 20% by mass, the inside (lower part) is not cured and the possibility of liquid crystal contamination is likely to increase.

(D) Epoxy Compound (D) The epoxy compound is a compound having at least one epoxy group in one molecule, and is a component that reacts and cures by heating. (D) The tension | pulling adhesive strength improves by mix | blending a component. Examples of the component (D) include an aliphatic compound having an epoxy group, an alicyclic compound having an epoxy group, and an aromatic compound having an epoxy group. An aromatic compound having an epoxy group is preferred.

Specific examples of the aliphatic compound having an epoxy group include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, and polyethylene glycol. Diglycidyl ether, glycerin triglycidyl ether, polypropylene glycol diglycidyl ethers; polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin Polyglycidyl ethers; diglycidyl esters of aliphatic long-chain dibasic acids; monoglycidyl ethers of higher aliphatic alcohols; glycidyl of higher fatty acids Esters; epoxidized soybean oil; butyl epoxy stearate, epoxy stearic octyl, epoxidized linseed oil, epoxy polybutadiene, and the like.
Commercially available aliphatic compounds having an epoxy group include SR-NPG, SR-16H, SR-PG, SR-TPG (above, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.); PG-202, PG-207 (above, Toto Kasei) EX-610U, EX-1610-P (manufactured by Nagase ChemteX Corporation) and the like.

Specific examples of the alicyclic compound having an epoxy group include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3. , 4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl- 3 ′, 4′-epoxy-6′-methylcyclohexanecarboxylate, ε-caprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl- 3 ', 4'-epoxy Rhohexanecarboxylate, β-methyl-δ-valerolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, methylene bis (3,4-epoxycyclohexane), di (3,4) of ethylene glycol 4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexanecarboxylate), epoxycyclohexahydrophthalic acid dioctyl, epoxycyclohexahydrophthalic acid di-2-ethylhexyl, and the like.
Examples of commercially available alicyclic compounds having an epoxy group include Celoxide 2021, Celoxide 2021P, Celoxide 2081, Celoxide 2083, Celoxide 2085, Epolide GT-300, Epolide GT-301, Epolide GT-302, Epolide GT-400, Epolide. 401, epolide 403 (manufactured by Daicel Chemical Industries, Ltd.) and the like.

  Examples of the aromatic compound having an epoxy group include compounds having an aromatic ring structure in the main skeleton and having two or more epoxy groups. Examples of the aromatic ring structure of such a compound include a bisphenol A type structure, a bisphenol F type structure, a novolac type structure, a naphthalene skeleton, an anthracene skeleton structure, and a fluorene skeleton.

  As commercial products of aromatic compounds having an epoxy group, JER806, JER828, YL980 (above, manufactured by Japan Epoxy Resin Co., Ltd.); YD-127, YD-128, YDF-170, YDF-175S, YDPN-638, YDCN- 701 (manufactured by Toto Kasei Co., Ltd.); EPICLON 830, EPICLON 850, EPICLON 835, EPICLON HP-4032D (manufactured by DIC);

  The compounding amount of the component (D) in the composition of the present invention is 1 to 90% by mass, preferably 5 to 80% by mass, more preferably 5 to 60% by mass, when the entire composition is 100% by mass. It is. If the blending amount of component (D) exceeds 90% by mass, an appropriate hardness cannot be obtained when irradiated with ultraviolet rays, and there is a possibility that displacement due to heat tends to occur.

(E) Organic resin particles The curable composition of the present invention contains organic resin particles. By containing the organic resin particles, the adhesive strength can be increased.
As the organic resin particles, solid particles such as acrylic fine particles are preferably used.

  Examples of the acrylic fine particles include a methyl methacrylate polymer, a copolymer of methacrylic acid and an alkyl compound, and among these, as commercially available ones, for example, Zefiac F-320, F-301, F-340, F-325, F-351 (made by Zeon Kasei Co., Ltd.), etc. are mentioned.

  The compounding quantity of the component (E) in the composition of this invention is 0.1-50 mass% when the whole composition is 100 mass%, Preferably it is 1-40 mass%. When the blending amount is less than 0.1% by mass, sufficient gelling action is not exhibited, the fluidity of the seal part is increased during heating, and the seal part is deformed or broken, and when it exceeds 50% by mass, Viscosity at room temperature increases and dispensing properties are significantly reduced.

(F) Inorganic fine particles The inorganic fine particles are preferably used because the effect of improving the dimensional stability can be expressed (improved or 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 for bonding the glass substrates 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 0 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. If the blending amount of component (F) is more than 50% by mass, there is a possibility that the gap formation for bonding the glass substrates during the production of the liquid crystal cell will 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. .1 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 components Other components can be mix | blended with the composition of this invention in the range which does not impair the effect of this invention. Examples of such additives include photo radical initiators other than component (C), partially (meth) acryloylated epoxy resins, reactive (meth) acrylic polymers, sensitizers, chain transfer agents, antifoaming agents, Examples thereof include an ion scavenger, a water absorbing agent, a leveling agent, and a spacer.

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 cured by further heating after 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 500~10,000mJ / cm ^2, more preferably a 1,000~3,000mJ / 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 1,000 Pa · s, more preferably 100 to 500 Pa · s, from the viewpoint of dispensing properties and shape preservation properties.

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 by mass of 2-isocyanatoethyl acrylate (Karenz AOI manufactured by Showa Denko KK) in a vessel equipped with a stirrer and 0.1 mass of dibutyltin dilaurate 24.6 parts by mass of glycerin (purified glycerin manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) was added dropwise at 10 ° C. for 1 hour, followed by stirring at 60 ° C. for 4 hours. It was set as the reaction liquid.
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 by mass 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 2-9 and Comparative Examples 1-5
Each curable composition was manufactured like Example 1 except having set it as the composition shown in the following Table 1 and Table 2.

<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 Tables 1 and 2.

1. Tensile bond strength [Glass]
A dispersion of 1 part by weight of spacer particles 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 uniformly. 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. It can be said that the larger the value of the adhesive strength, the better the adhesiveness.

2. Tensile bond strength [alignment film]
On the slide glass, Optomer AL60101 (manufactured by JSR) was applied as an alignment film, and heated in an oven at 200 ° C. substituted with nitrogen for 1 hour to form a coating film. Except for using this slide glass, 1. The adhesive strength was measured by performing the same operation as described above. It can be said that the larger the value of the adhesive strength, the better the adhesiveness.

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 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).

4). 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 (at this time, the center of the sealing agent 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 inner part 1 mm from the non-shielding part and the end of the shielding part, 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

○: The acrylic reaction rate at a portion 1 mm from the end of the shielding portion is 50% or more.

Commercial products in Tables 1 and 2 represent the following.
EB3700: Daicel Cytec Co., Ltd. bisphenol A-containing epoxy acrylate Glycerin-AOI: synthesized in Production Example 1

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

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

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

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

  Irgacure OX01 ((Ciba Specialty Chemicals Co., Ltd.))

Zefiac F320: PMMA particles manufactured by Ganz Kasei Co., Ltd., average particle size 1 μm
Zefiac F325: PMMA particles manufactured by Ganz Kasei Co., Ltd., average particle size 0.5 μm
Zefiac F351: Core shell acrylate copolymer particles manufactured by Ganz Kasei Co., Ltd., average particle size 0.3 μm

Admafine SE3200-SEJ: Epoxy-modified silica particles manufactured by Admatechs Co., Ltd., average particle size 1 μm
SH6040: Toray Dow Corning Co., Ltd. silane coupling agent; γ-glycidoxypropyltrimethoxysilane

KIP150 (made by Lamberti)

  From the results in Table 1, it can be seen that the curable compositions of Examples using a high-sensitivity photoradical polymerization initiator (component (C)) exhibit excellent dark part curability. Moreover, it turns out that the Example which mix | blended the organic particle (component (E)) has strengthened tensile adhesive strength with both glass and alignment film board | substrate.

Since the liquid crystal sealant of the present invention is sufficiently cured even in a portion not directly irradiated with ultraviolet rays overlapping with a wiring, a black matrix, etc. due to a recent demand for a narrower frame, the liquid crystal sealant has high adhesion to the substrate and is an uncured liquid crystal The possibility of liquid crystal contamination due to the sealant component is reduced, and a liquid crystal display element having excellent long-term stability can be provided.
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.

Explanation of symbols

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)

(A) (Meth) acrylate compound (B) Epoxy curing agent (C) Photoradical polymerization initiator having an oxime ester structure (D) Epoxy compound (E) A curable composition containing organic particles. The curable composition according to claim 1, wherein the radical photopolymerization initiator (C) having an oxime ester structure is represented by the following general formula (c-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 substituted or unsubstituted phenyl group, or an alkyl group having 1 to 10 carbon atoms, R ³ represents a substituted or unsubstituted carbazole group or a Ph—S—Ph—CO— group (Ph represents a phenyl group or a phenylene group).   The curable composition according to claim 1 or 2, wherein the (D) epoxy compound contains a compound having two or more epoxy groups in the molecule.   The curable composition according to any one of claims 1 to 3, wherein the (E) organic particles are acrylic resin particles.   Furthermore, (F) The curable composition of any one of Claims 1-4 containing an inorganic fine particle. Furthermore, (G) The curable composition of any one of Claims 1-5 containing a silane coupling agent.   The liquid-crystal sealing compound which consists of a curable composition of any one of Claims 1-6.   The liquid crystal display element manufactured using the liquid-crystal sealing compound of Claim 7.

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