JPWO2009128470A1 - Liquid crystal dropping method sealing agent, liquid crystal panel sealing agent, vertical conduction material, and liquid crystal display element - Google Patents

Abstract

An object of the present invention is to provide a sealing agent for a liquid crystal dropping method capable of manufacturing a liquid crystal display element having a high quality image with little color unevenness even when the liquid crystal display element is manufactured by a dropping method. To do. The present invention is a sealing agent for a liquid crystal dropping method containing a resin having a (meth) acryl group and a polymer azo initiator.

Description

The present invention relates to a sealing agent for a liquid crystal dropping method capable of manufacturing a liquid crystal display element having a high quality image with little color unevenness even when the liquid crystal display element is manufactured by a dropping method. Further, the present invention relates to a sealing agent for a liquid crystal panel, which can produce a liquid crystal display element having a high quality image with little color unevenness when a liquid crystal display device is manufactured by a vacuum injection method.

Conventionally, a liquid crystal display element such as a liquid crystal display cell is formed by forming a cell by facing two transparent substrates with electrodes facing each other at a predetermined interval and sealing the periphery with a sealing agent. The liquid crystal was injected from the liquid crystal injection port into the cell, and the liquid crystal injection port was manufactured by a method called a vacuum injection method in which a sealing agent or a sealing agent was sealed.

In the vacuum injection method, first, a seal pattern having a liquid crystal injection port using a thermosetting sealant is formed by screen printing on one of two transparent substrates with electrodes, and prebaked at 60 to 100 ° C. The solvent in the sealant is dried. Next, alignment is performed with the two substrates facing each other with a spacer interposed therebetween, and the gap in the vicinity of the seal is adjusted by performing hot pressing at 110 to 220 ° C. for 10 to 90 minutes, and then at 110 to 220 ° C. in an oven. Heat for 10 to 120 minutes to fully cure the sealant. Next, liquid crystal was injected from the liquid crystal injection port, and finally, the liquid crystal injection port was sealed using a sealing agent to produce a liquid crystal display element.

However, in recent years, a method for manufacturing a liquid crystal display device such as a liquid crystal display cell has been disclosed in, for example, Patent Document 1 and Patent Document 2 from the above-described vacuum injection method from the viewpoint of shortening tact time and optimizing the amount of liquid crystal used. Dropping with a sealant comprising a photocurable and heat-curable resin composition containing a photocurable acrylic resin and a photopolymerization initiator, and a thermosetting epoxy resin and a thermal polymerization initiator The liquid crystal dripping method called construction method is being replaced.

In the liquid crystal dropping method, first, a seal pattern is formed on one of the two substrates with electrodes. Next, a liquid crystal micro-droplet is dropped on the entire surface of the substrate frame in an uncured state of the sealing agent, the other substrate is superposed under vacuum, and after returning to normal pressure, the sealing portion is irradiated with ultraviolet rays to irradiate the acrylic resin. Curing is performed (temporary curing step). Thereafter, the epoxy resin is cured by heating to produce a liquid crystal display element.

By the way, in the present age when mobile devices with various liquid crystal panels such as mobile phones and portable game machines are widespread, downsizing of devices is the most demanded issue. As a technique for miniaturization, there is a narrow frame of the liquid crystal display unit, and for example, the position of the seal portion is arranged under the black matrix (hereinafter also referred to as a narrow frame design).

However, when the dripping method is performed with a narrow frame design, there are places where the black matrix does not receive light on the seal part, so there is a portion of acrylic resin that does not sufficiently irradiate light and does not proceed with curing. There was a problem that the cured acrylic resin was eluted, the liquid crystal was contaminated, and liquid crystal display unevenness occurred.
In order to irradiate the seal part under the black matrix without fail, a method of irradiating light from the back side of the substrate, that is, from the array side is conceivable. However, metal wiring, transistors, etc. also exist on the array substrate. There are places where the seal part is not exposed to light.

In order to reliably cure the uncured acrylic resin even after light irradiation, a method using a sealing agent containing a low molecular weight peroxide or an azo compound as a component for thermally curing the acrylic resin is also available. Conceivable. When such a sealant is used, the acrylic resin that has not been cured in the temporary curing step can be cured by heating during liquid crystal annealing. However, elution of low molecular weight peroxides or azo compounds into the liquid crystal causes color unevenness around the seal portion, which makes it impossible to obtain a liquid crystal display element with a high quality image.

On the other hand, when the liquid crystal display device is manufactured by the vacuum injection method which is a conventional method, there is a problem similar to the case of the liquid crystal dropping method. That is, when a liquid crystal display device is manufactured by a vacuum injection method, the liquid crystal panel sealing agent used for sealing the liquid crystal comes into contact with the liquid crystal in an uncured state. Here, when sufficient light is not irradiated to the sealing agent for liquid crystal panels, color unevenness also occurs around the sealing portion, and a liquid crystal display element with a high-quality image cannot be obtained.

JP 2001-133794 A JP-A-5-295087

In view of the above situation, the present invention provides a liquid crystal dropping method sealing agent capable of producing a liquid crystal display element having a high quality image with little color unevenness even when a liquid crystal display element is produced by a dropping method. The purpose is to do. Another object of the present invention is to provide a sealing agent for a liquid crystal panel, which can produce a liquid crystal display element with a high quality image with little color unevenness when a liquid crystal display device is manufactured by a vacuum injection method.

The present invention is a sealant for a liquid crystal dropping method containing a resin having a (meth) acryl group and a polymer azo initiator.
The present invention is a sealing agent for liquid crystal panels containing a resin having a (meth) acryl group and a polymer azo initiator.
The present invention is described in detail below.

As a result of intensive studies, the present inventors have found that the sealing agent for liquid crystal dropping method containing a resin having a (meth) acrylic group and a polymer azo initiator has no adverse effect on the liquid crystal of the azo initiator itself during thermal curing. In addition, it has been found that by curing a resin having an uncured (meth) acrylic group, a liquid crystal display element having a high quality image with little color unevenness can be produced, and the present invention has been completed. It was.

The sealing agent for liquid crystal dropping method of the present invention contains a polymer azo initiator.
In the sealing agent for liquid crystal dropping method of the present invention, by using such an initiator, it is possible to reliably cure by heat even in a seal portion where light is not irradiated by a black matrix or the like. Very little liquid crystal contamination occurs.
In the present specification, the polymer azo initiator means a compound having an azo group and having a molecular weight of 300 or more for generating a radical capable of curing a (meth) acryl group with heat.
In addition, since the said polymeric azo initiator decomposes | disassembles also by light irradiation normally and generate | occur | produces a radical, it can function also as a photoradical initiator.

The preferable lower limit of the number average molecular weight of the polymeric azo initiator is 1000, and the preferable upper limit is 300,000. If the number average molecular weight of the polymer azo initiator is less than 1000, the polymer azo initiator may adversely affect the liquid crystal, and if it exceeds 300,000, mixing with a resin having a (meth) acryl group may occur. It can be difficult. The more preferable lower limit of the number average molecular weight of the polymeric azo initiator is 5000, the more preferable upper limit is 100,000, the still more preferable lower limit is 10,000, and the still more preferable upper limit is 90,000.

The polymer azo initiator has a preferred lower limit of 10 hours half-life temperature of 50 ° C. and a preferred upper limit of 90 ° C. When the 10-hour half-life temperature of the polymer azo compound is less than 50 ° C., the storage stability of the obtained liquid crystal dropping method sealing agent may be deteriorated. When the 10-hour half-life temperature of the polymer azo compound exceeds 90 ° C., the curing of the sealing agent for liquid crystal dropping method of the present invention requires a high temperature and a long time, which may affect panel productivity.

Examples of the polymer azo initiator include those having a structure in which a plurality of units such as polydimethylsiloxane and polyalkylene oxide are bonded via an azo group.
As a structure in which a plurality of units such as polyalkylene oxide are bonded, those having a polyethylene oxide structure are preferable.
Examples of such a polymer azo initiator include polycondensates of 4,4′-azobis (4-cyanopentanoic acid) and polyalkylene glycol, and 4,4′-azobis (4-cyanopentanoic acid) and terminal. Examples thereof include polycondensates of polydimethylsiloxane having an amino group, such as VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001 (all manufactured by Wako Pure Chemical Industries, Ltd.). Etc.

In addition to the above polymer azo compounds, polymer azo compounds represented by the following general formula (I) described in JP-A-2008-50572 and JP-A-2003-12784 can also be suitably used. .

In formula (I), R ¹² , R ¹³ , R ²² and R ²³ each independently represents an alkyl group having 1 to 10 carbon atoms or a cyano group, and a and b each independently represent 0 to 4 A ¹¹ and A ¹² are polymer chains, and Y ¹¹ and Y ¹² are each independently —CO—O—, —O—CO—, —NH—CO—, —CO—. NH—, —O— or —S—.

In the general formula (I), the alkyl group having 1 to 10 carbon atoms represented by R ¹² , R ¹³ , R ²² and R ²³ is methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl. , Isobutyl, amyl, isoamyl, t-amyl, hexyl, cyclohexyl, cyclohexylmethyl, cyclohexylethyl, heptyl, isoheptyl, t-heptyl, n-octyl, isooctyl, t-octyl, 2-ethylhexyl, n-nonyl, n-decyl Etc.

In the above general formula (I), the polymer chains represented by A ¹¹ and A ¹² are not particularly limited. For example, polyoxylene chain, polymethylene chain, polyether chain, polyester chain, polysiloxane chain, poly (meth) acrylate Examples thereof include a chain, a polystyrene-vinyl acetate chain, a polyamide chain, a polyimide chain, a polyurethane chain, a polyurea chain, and a polypeptide chain. Among ^{them, Y 11} is ^-O-CO-, preferably compounds ^{Y 12} is ^-CO-O-, the polymer chain represented by ^{A 11} and ^{A 12,} is a polyether chain and a polyester chain Those are more preferred because they are particularly inexpensive and easy to manufacture.

Among the above general formula (I), among the polymer azo compounds in which A ¹¹ and A ¹² are polyether chains, the compound represented by the following general formula (II) has good solubility and the molecular weight of the polymerization initiator. It is more preferable because it gives a grafted pigment that is easy to control and highly dispersible.

In the formula (II), R ¹² , R ¹³ , R ²² , R ²³ , a and b are the same as those in the general formula (I), and R ¹¹ and R ²¹ are each independently selected from 1 to 24 represents an alkyl group, Z ¹¹ , Z ¹² , Z ²¹ and Z ²² each independently represent an alkylene group having 1 to 4 carbon atoms, and m, n, s and t each independently represent 0 The sum of m + n and the sum of s + t are each independently 2 or more. )

In the general formula (II), the alkylene group having 1 to 4 carbon atoms represented by Z ¹¹ , Z ¹² , Z ²¹ and Z ²² is methylene, ethylene, trimethylene, propylene, propylidene, isopropylidene, tetramethylene, butylene. , Isobutylene, ethylethylene, dimethylethylene and the like, and the alkyl group having 1 to 24 carbon atoms represented by R ¹¹ and R ²¹ is methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, Isobutyl, amyl, isoamyl, t-amyl, hexyl, cyclohexyl, cyclohexylmethyl, cyclohexylethyl, heptyl, isoheptyl, t-heptyl, n-octyl, isooctyl, t-octyl, 2-ethylhexyl, n-nonyl, n-decyl, Lauryl, stearyl, be Alkylsulfonyl and the like. The alkyl group having 1 to 24 carbon atoms represented by R ¹¹ and R ²¹ has a carbon atom number of 1 to 4 to give a highly dispersible grafted pigment, and to one end of the chain polymer. Since the reactivity of the esterification reaction between the compound having a hydroxyl group and the azodicarboxylic acid compound is high, it is preferable.

Among the polymer azo compounds represented by the general formula (I) in which A ¹¹ and A ¹² are polyester chains, the compound represented by the following general formula (III) has good solubility and excellent water resistance. This is preferable.

In the formula (III), R ¹² , R ¹³ , R ²² , R ²³ , a and b are the same as those in the general formula (I), and Z ¹³ and Z ²³ each independently represent 1 to 18 represents an alkylene group, R ³¹ and R ⁴¹ each independently represent a hydrogen atom or an alkyl group having 1 to 24 carbon atoms, and p and u are each independently a number from 1 to 1000. )

In the general formula (III), the alkylene group having 1 to 18 carbon atoms represented by Z ¹³ and Z ²³ is methylene, ethylene, trimethylene, propylene, propylidene, isopropylidene, tetramethylene, butylene, isobutylene, ethylethylene, Dimethylethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, 1,4-pentanediyl, decamethylene, undecamethylene, 1,4-undecandiyl, dodecane, 1,11-heptadecandiyl, octadecamethylene, etc. Examples of the alkyl group having 1 to 24 carbon atoms represented by R ³¹ and R ⁴¹ include those exemplified as R ¹¹ and R ²¹ in the general formula (II). The alkyl group having 1 to 24 carbon atoms represented by R ³¹ and R ⁴¹ has a carbon atom number of 1 to 4 to give a highly dispersible grafted pigment, and to one end of the chain polymer. Since the reactivity of the esterification reaction between the compound having a hydroxyl group and the azodicarboxylic acid compound is high, it is preferable.

In the general formula (III), p and u are 20 to 100 to give a highly dispersible grafted pigment, and a compound having a hydroxyl group at one end of the chain polymer and an azodicarboxylic acid compound This is preferable because of the high reactivity of the esterification reaction.

The content of the polymer azo initiator in the liquid crystal dropping method sealing agent of the present invention is not particularly limited, but a preferred lower limit is preferably 0.1 parts by weight with respect to 100 parts by weight of the resin having the (meth) acryl group. The upper limit is 30 parts by weight. When the content of the polymer azo initiator is less than 0.1 parts by weight, the polymerization of the resin having the (meth) acryl group may not sufficiently proceed. If the content of the polymer azo initiator exceeds 30 parts by weight, the viscosity of the obtained liquid crystal dropping method sealing agent increases, which may adversely affect coating workability and the like. The minimum with more preferable content of the said polymeric azo initiator is 0.5 weight part, and a more preferable upper limit is 10 weight part.

The sealing agent for liquid crystal dropping method of the present invention contains a resin having a (meth) acryl group.
The resin having the (meth) acrylic group is not particularly limited. For example, an ester compound obtained by reacting a compound having a hydroxyl group with (meth) acrylic acid, or reacting (meth) acrylic acid with an epoxy compound. Epoxy (meth) acrylate obtained by the above, urethane (meth) acrylate obtained by reacting an isocyanate with a (meth) acrylic acid derivative having a hydroxyl group, and the like.

The ester compound obtained by reacting the (meth) acrylic acid with a compound having a hydroxyl group is not particularly limited, and examples of the monofunctional ester compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meta ) Acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) ) Acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, 2-ethoxyethyl (meth) acrylate Tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, methoxy polyethylene 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 (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) acrylic Leuoxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl 2-hydroxypropyl phthalate, glycidyl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate, etc. Is mentioned.

Bifunctional ester compounds include, for example, 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 dicyclopentadienyl 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 , Polyether diol di (meth) acrylate, polyester diol di (meth) acrylate, polycaprolactone diol di (meth) acrylate, polybutadiene Oruji (meth) acrylate.

The trifunctional or higher functional ester compounds include, for example, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, propylene oxide-added trimethylolpropane tri (meth) acrylate, and 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 glyce Entry (meth) acrylate, tris (meth) acryloyloxyethyl phosphate, and the like.

The epoxy (meth) acrylate obtained by reacting the (meth) acrylic acid and the epoxy compound is not particularly limited. For example, an epoxy resin and (meth) acrylic acid are combined in the presence of a basic catalyst according to a conventional method. And the like obtained by reacting with.

The epoxy compound used as a raw material for synthesizing the epoxy (meth) acrylate is not particularly limited, and commercially available products include, for example, bisphenol A type such as Epicoat 828EL and Epicoat 1004 (both manufactured by Japan Epoxy Resin Co., Ltd.). Epoxy resins, bisphenol F-type epoxy resins such as Epicoat 806 and Epicoat 4004 (all manufactured by Japan Epoxy Resin), bisphenol S-type epoxy resins such as Epicron EXA1514 (produced by Dainippon Ink), and RE-810NM (Japan) 2,2′-diallyl bisphenol A type epoxy resin such as Kayaku Co., Ltd., hydrogenated bisphenol type epoxy resin such as Epicron EXA7015 (Dainippon Ink Co., Ltd.), EP-4000S (Asahi Denka Co., Ltd.), etc. Propylene oxide-added bisphe A-type epoxy resin, resorcinol-type epoxy resin such as EX-201 (manufactured by Nagase ChemteX), biphenyl-type epoxy resin such as Epicoat YX-4000H (manufactured by Japan Epoxy Resin), YSLV-50TE (Tokyo) Sulfide type epoxy resin such as Kasei Co., Ltd., ether type epoxy resin such as YSLV-80DE (manufactured by Tohto Kasei Co., Ltd.), dicyclopentadiene type epoxy resin such as EP-4088S (Asahi Denka Co., Ltd.), and Epicron HP4032. Naphthalene type epoxy resins such as Epicron EXA-4700 (all manufactured by Dainippon Ink), phenol novolac type epoxy resins such as Epicron N-770 (made by Dainippon Ink), and Epicron N-670-EXP-S. Orthocresol novolac type (Dainippon Ink Co., Ltd.) Poxy resin, dicyclopentadiene novolac type epoxy resin such as Epicron HP7200 (manufactured by Dainippon Ink and Co., Ltd.), biphenyl novolac type epoxy resin such as NC-3000P (manufactured by Nippon Kayaku Co., Ltd.), ESN-165S (Toto Kasei Co., Ltd.) Naphthalenephenol novolak type epoxy resins such as Epicote 630 (manufactured by Japan Epoxy Resin Co., Ltd.), Epicron 430 (manufactured by Dainippon Ink Co., Ltd.), TETRAD-X (manufactured by Mitsubishi Gas Chemical Company), etc. Alkyl polyol type epoxy resins such as ZX-1542 (manufactured by Tohto Kasei Co., Ltd.), Epiklon 726 (manufactured by Dainippon Ink and Chemicals), Epolite 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.), Denacol EX-611 (manufactured by Nagase ChemteX) , YR-450, YR-207 Kasei), Epolide PB (Daicel Chemicals) and other rubber-modified epoxy resins, Denacor EX-147 (Nagase ChemteX) glycidyl ester compounds and Epicoat YL-7000 (Japan Epoxy Resin) Bisphenol A type episulfide resin such as YDC-1312, YSLV-80XY, YSLV-90CR (all manufactured by Tohto Kasei Co., Ltd.), XAC4151 (manufactured by Asahi Kasei Co., Ltd.), Epicoat 1031 and Epicoat 1032 (all Japan Epoxy Resins) Product), EXA-7120 (Dainippon Ink Co., Ltd.), TEPIC (Nissan Chemical Co., Ltd.) and the like.

Specifically, the epoxy (meth) acrylate obtained by reacting the (meth) acrylic acid and the epoxy compound is, for example, 360 parts by weight of a resorcinol type epoxy resin (EX-201, manufactured by Nagase ChemteX Corporation), It can be obtained by reacting 2 parts by weight of p-methoxyphenol as a polymerization inhibitor, 2 parts by weight of triethylamine as a reaction catalyst, and 210 parts by weight of acrylic acid for 5 hours while refluxing and stirring at 90 ° C.

Moreover, the commercial item of the said epoxy (meth) acrylate is, for example, Evecri 3700, Evekril 3600, Evekril 3701, Evekril 3703, Evekrill 3201, Evekril 3600, Evekril 3702, Evekrill 3412, Evekril 860, Evekril RDX63182e , Evecri 3800 (all manufactured by Daicel Cytec Co., Ltd.), EA-1020, EA-1010, EA-5520, EA-5323, EA-CHD, EMA-1020 (all manufactured by Shin-Nakamura Chemical Co., Ltd.), Epoxy ester M- 600A, epoxy ester 40EM, epoxy ester 70PA, epoxy ester 200PA, epoxy ester 80MFA, epoxy ester 3002M, epoxy ester 002A, Epoxy ester 1600A, Epoxy ester 3000M, Epoxy ester 3000A, Epoxy ester 200EA, Epoxy ester 400EA (all manufactured by Kyoeisha Chemical Co., Ltd.), Denacol acrylate DA-141, Denacol acrylate DA-314, Denacol acrylate DA-911 (Both manufactured by Nagase ChemteX Corporation).

The urethane (meth) acrylate obtained by reacting the isocyanate with a (meth) acrylic acid derivative having a hydroxyl group is, for example, a (meth) acrylic acid derivative 2 having a hydroxyl group with respect to 1 equivalent of a compound having two isocyanate groups. The equivalent weight can be obtained by reacting in the presence of a catalytic amount of a tin-based compound.

Isocyanate that is a raw material of urethane (meth) acrylate obtained by reacting a hydroxyl group-containing (meth) acrylic acid derivative with the isocyanate is not particularly limited. For example, isophorone diisocyanate, 2,4-tolylene diisocyanate, 2, 6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4′-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene Range Iocyanate (XDI), Hydrogenated XDI, Lysine Diisocyanate, Triphenylmethane Triisocyanate, Tris (Isocyanate Phenyl) Thioff Sufeto, tetramethyl xylene diisocyanate, 1,6,10- undecene country isocyanate.

Moreover, the isocyanate used as the raw material of the urethane (meth) acrylate obtained by making the said isocyanate react with the (meth) acrylic acid derivative which has a hydroxyl group is not specifically limited, For example, ethylene glycol, glycerol, sorbitol, a trimethylol propane, Chain-extended isocyanate compounds obtained by reaction of polyols such as (poly) propylene glycol, carbonate diol, polyether diol, polyester diol, polycaprolactone diol and excess isocyanate can also be used.

The (meth) acrylic acid derivative having a hydroxyl group, which is a raw material for urethane (meth) acrylate obtained by reacting the isocyanate with a (meth) acrylic acid derivative having a hydroxyl group, is not particularly limited. For example, 2-hydroxyethyl Commercial products such as (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, ethylene glycol, propylene glycol, 1,3-propanediol, 1 Mono (meth) acrylates of divalent alcohols such as 1,3-butanediol, 1,4-butanediol and polyethylene glycol, mono (meth) acrylates of trivalent alcohols such as trimethylolethane, trimethylolpropane and glycerin, or (Meth) acrylates, epoxy acrylates such as bisphenol A-modified epoxy acrylate.

Specifically, the urethane (meth) acrylate obtained by reacting the isocyanate with a hydroxyl group-containing (meth) acrylic acid derivative is, for example, 134 parts by weight of trimethylolpropane, 0.2 part by weight of BHT as a polymerization inhibitor, As reaction catalysts, 0.01 parts by weight of dibutyltin dilaurate and 666 parts by weight of isophorone diisocyanate were added and reacted at 60 ° C. with stirring under reflux for 2 hours. Next, 51 parts by weight of 2-hydroxyethyl acrylate was added and air was fed. It can be obtained by reacting at 90 ° C. with stirring under reflux for 2 hours.

Examples of commercially available urethane (meth) acrylates include M-1100, M-1200, M-1210, and M-1600 (all manufactured by Toagosei Co., Ltd.), Evecryl 230, Evekril 270, Evekril 4858, Evekril. 8402, Evecryl 8804, Evekril 8803, Evekril 8807, Evekril 9260, Evekril 1290, Evekrill 5129, Evekril 4842, Evekril 210, Evekril 4827, Evekril 6700, Evekrill 220, Evekrill 2220 (all manufactured by Daicel Cytec J. N) 9000H, Art Resin UN-9000A, Art Resin UN-7100, Art Resin UN-1255, Art Resin UN-330, Art Resin UN-3320HB, A Toresin UN-1200TPK, Art Resin SH-500B (all manufactured by Negami Kogyo Co., Ltd.), U-122P, U-108A, U-340P, U-4HA, U-6HA, U-324A, U-15HA, UA-5201P , UA-W2A, U-1084A, U-6LPA, U-2HA, U-2PHA, UA-4100, UA-7100, UA-4200, UA-4400, UA-340P, U-3HA, UA-7200, U -2061BA, U-10H, U-122A, U-340A, U-108, U-6H, UA-4000 (all manufactured by Shin-Nakamura Chemical Co., Ltd.), AH-600, AT-600, UA-306H, AI -600, UA-101T, UA-101I, UA-306T, UA-306I and the like.

The resin having the (meth) acryl group is preferably one having a hydrogen-bonding unit such as —OH group, —NH— group, and —NH ₂ group in terms of suppressing adverse effects on the liquid crystal, and is easy to synthesize. From the above, epoxy (meth) acrylate is particularly preferable.
The resin having the (meth) acryl group is preferably one having 2 to 3 (meth) acryl groups in the molecule because of its high reactivity.

The sealing agent for liquid crystal dropping method of the present invention preferably further contains a resin having an epoxy group in order to improve adhesiveness.

The resin having the epoxy group is not particularly limited, and commercially available resins include, for example, bisphenol A type epoxy resins such as Epicoat 828EL and Epicoat 1004 (all manufactured by Japan Epoxy Resin Co., Ltd.), Epicoat 806 and Epicoat 4004 ( 2,2 such as bisphenol F type epoxy resin such as Japan Epoxy Resin Co., Ltd., bisphenol S type epoxy resin such as Epicron EXA1514 (Dainippon Ink Co., Ltd.), RE-810NM (Nippon Kayaku Co., Ltd.), etc. '-Diallyl bisphenol A type epoxy resin, hydrogenated bisphenol type epoxy resin such as Epicron EXA7015 (manufactured by Dainippon Ink), propylene oxide-added bisphenol A type epoxy resin such as EP-4000S (manufactured by Asahi Denka), EX-201 (Nagase Resuscinol type epoxy resin such as Mutex), biphenyl type epoxy resin such as Epicoat YX-4000H (Japan Epoxy Resin), sulfide type epoxy resin such as YSLV-50TE (manufactured by Toto Kasei), YSLV- Ether type epoxy resin such as 80DE (manufactured by Tohto Kasei Co., Ltd.), dicyclopentadiene type epoxy resin such as EP-4088S (manufactured by Asahi Denka Co., Ltd.), Epiklon HP4032, Epiklone EXA-4700 (both manufactured by Dainippon Ink Co., Ltd.) Such as naphthalene type epoxy resin, phenol novolac type epoxy resin such as Epicron N-770 (manufactured by Dainippon Ink), and orthocresol novolak type epoxy such as Epicron N-670-EXP-S (manufactured by Dainippon Ink). Resin and Epicron HP7200 (Dainippon Dicyclopentadiene novolac epoxy resin such as NC-3000P (manufactured by Nippon Kayaku Co., Ltd.), naphthalene phenol novolac epoxy such as ESN-165S (manufactured by Tohto Kasei Co., Ltd.), etc. Resins, glycidylamine type epoxy resins such as Epicoat 630 (manufactured by Japan Epoxy Resin), Epicron 430 (manufactured by Dainippon Ink), TETRAD-X (manufactured by Mitsubishi Gas Chemical Company), and ZX-1542 (manufactured by Tohto Kasei Co., Ltd.) ), Epicron 726 (manufactured by Dainippon Ink & Co.), Epolite 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.), Denacol EX-611, (manufactured by Nagase ChemteX Corporation), and other alkyl polyol type epoxy resins, YR-450, YR-207 ( All are manufactured by Toto Kasei Co., Ltd.), Epolide PB (manufactured by Daicel Chemical Industries) Rubber modified epoxy resins such as glycidyl ester compounds such as Denacol EX-147 (manufactured by Nagase ChemteX), bisphenol A type episulfide resins such as Epicoat YL-7000 (manufactured by Japan Epoxy Resin), and other YDC- 1312, YSLV-80XY, YSLV-90CR (all manufactured by Tohto Kasei Co., Ltd.), XAC4151 (manufactured by Asahi Kasei Co., Ltd.), Epicoat 1031, Epicoat 1032 (all manufactured by Japan Epoxy Resin Co., Ltd.), EXA-7120 (manufactured by Dainippon Ink & Chemicals) , TEPIC (manufactured by Nissan Chemical Co., Ltd.) and the like.

Moreover, the resin which has the said epoxy group may be a compound which has a (meth) acryl group and an epoxy group in 1 molecule, for example. Examples of such a compound include a compound obtained by reacting a part of the epoxy group of a compound having two or more epoxy groups with (meth) acrylic acid.

The compound obtained by reacting a part of the epoxy groups having two or more epoxy groups with (meth) acrylic acid is prepared by, for example, reacting an epoxy resin and (meth) acrylic acid with a basic catalyst according to a conventional method. It is obtained by reacting in the presence. Specifically, for example, 190 g of phenol novolac type epoxy resin N-770 (manufactured by Dainippon Ink & Co., Ltd.) is dissolved in 500 mL of toluene, and 0.1 g of triphenylphosphine is added to this solution to obtain a uniform solution. After adding dropwise 35 g of acrylic acid over 2 hours under reflux stirring, the mixture was further stirred under reflux for 6 hours. Next, by removing toluene, a novolak-type solid-modified epoxy in which 50 mol% of epoxy groups reacted with (meth) acrylic acid. A resin can be obtained (in this case 50% partially acrylated).

Among the compounds obtained by reacting a part of the epoxy groups having two or more epoxy groups with (meth) acrylic acid, a commercially available product is, for example, Eveacryl 1561 (manufactured by Daicel Cytec Co., Ltd.).

When the sealing agent for liquid crystal dropping method of the present invention contains the resin having the epoxy group, the (meth) acryl group is added so that the ratio of the (meth) acryl group to the epoxy group is 50:50 to 95: 5. It is preferable to mix a resin having an epoxy group and a resin having an epoxy group. If the ratio of the (meth) acrylic group is 50% or less, the liquid crystal may be contaminated because many uncured epoxy resin components are present even when the thermal polymerization with the azo initiator is completed. If the ratio of (meth) acrylic groups is 95% or more, sufficient adhesive strength may not be obtained.

When the sealing agent for liquid crystal dropping method of the present invention contains the resin having the epoxy group, it is preferable to further contain an epoxy thermosetting agent. The said epoxy thermosetting agent is not specifically limited, For example, organic acid hydrazide, an imidazole derivative, an amine compound, a polyhydric phenol type compound, an acid anhydride etc. are mentioned. Among these, solid organic acid hydrazide is preferably used.
The solid organic acid hydrazide is not particularly limited, and examples thereof include sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, malonic acid hydrazide, other Amicure VDH, and Amicure UDH (all manufactured by Ajinomoto Fine Techno Co., Ltd.).

Although content of the said epoxy thermosetting agent is not specifically limited, A preferable minimum is 1 weight part with respect to 100 weight part of resin which has the said epoxy group, and a preferable upper limit is 50 weight part. When the content of the epoxy thermosetting agent is less than 1 part by weight, the effect of containing the thermosetting agent is hardly obtained. When content of the said epoxy thermosetting agent exceeds 50 weight part, the viscosity of the sealing compound for liquid crystal dropping methods of this invention will become high, and applicability | paintability etc. may be impaired. The upper limit with more preferable content of the said epoxy thermosetting agent is 30 weight part.

As described above, the sealing agent for the liquid crystal dropping method of the present invention can not only thermally cure the resin having the (meth) acrylic group but also photocure by using the polymer azo initiator. However, you may contain a photoinitiator further as needed. The photopolymerization initiator is not particularly limited, and those commercially available include, for example, Irgacure 184, Irgacure 2959, Irgacure 907, Irgacure 819, Irgacure 651, Irgacure 369, Irgacure 379, Irgacure OXE01 (all of which are Ciba Specialty. Chemicals), benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, Lucillin TPO (manufactured by BASF Japan) and the like.

Although content of the said photoinitiator is not specifically limited, A preferable minimum is 0.1 weight part with respect to 100 weight part of resin which has the said (meth) acryl group, and a preferable upper limit is 10 weight part. When the content of the photopolymerization initiator is less than 0.1 parts by weight, the liquid crystal dropping method sealing agent of the present invention may not be sufficiently photocured. When content of the said photoinitiator exceeds 10 weight part, storage stability may fall.

The sealing agent for liquid crystal dropping method of the present invention may further contain a light-shielding colorant.
By containing the light-shielding colorant, the liquid crystal dropping method sealing agent of the present invention is colored. Thereby, even when the width of the black mask is narrow and the sealant protrudes from the bottom of the black mask to the outside, it is possible to prevent a field where the light from the backlight leaks from the sealant and lowers the contrast.
When the light-shielding colorant is added to the conventional liquid crystal dropping method sealing agent, the light irradiation may be inhibited and the curability may be impaired. However, the liquid crystal dropping method sealing agent of the present invention can be reliably cured by heat by containing the resin having the (meth) acrylic group and the polymer azo initiator.
In this specification, “light shielding” means that light having a wavelength of 370 to 800 nm is shielded by 80% or more.

The light-shielding colorant is not particularly limited as long as it provides light-shielding property to the sealing agent for liquid crystal dropping method of the present invention after curing and has few impurities to the liquid crystal. The light-shielding colorant is preferably, for example, a black pigment or a plurality of pigments and / or dyes having a complementary color relationship that becomes black when mixed.

The black pigment is not particularly limited, and examples thereof include iron oxide, titanium black, aniline black, cyanine black, fullerene, carbon black, and resin-coated carbon black. The said black pigment may be used independently and 2 or more types may be used together. Of these, titanium black and / or carbon black are preferable from the viewpoints of insulation and workability.

The carbon black is not particularly limited as long as impurities are not easily eluted into the liquid crystal, and known carbon blacks such as channel black, lamp black, furnace black, and thermal black can be used. Among them, from the viewpoint of insulating properties, there are grafted carbon black whose surface is grafted, coated carbon black whose surface is coated with an insulating inorganic substance or insulating organic substance, and / or acidic carbon black whose surface is oxidized. preferable. Since such carbon black has low conductivity compared to untreated carbon black, when used in the sealing agent for liquid crystal dropping method of the present invention, a liquid crystal display element with low current leakage and high reliability can be obtained. Can do.

The titanium black is not particularly limited, and specific commercial products include, for example, 12S, 13M, 13MC, 13R-N (all of which are manufactured by Mitsubishi Materials Corporation), Tilac D (manufactured by Ako Kasei Co., Ltd.), and the like. It is done. In addition, the titanium black surface treated with a coupling agent or the one coated with an inorganic component such as silicon oxide, titanium oxide, germanium oxide, aluminum oxide, zirconium oxide, or magnesium oxide may be used. it can.

A plurality of organic pigments that have a complementary color relationship that becomes black when mixed are not particularly limited. For example, azo pigments such as insoluble azo pigments and soluble azo pigments, copper phthalocyanine blue pigments, halogenated copper phthalocyanine pigments, and sulfonated copper Phthalocyanine pigments such as phthalocyanine pigments, metal-free phthalocyanine pigments, dissimilar metal phthalocyanine pigments, and condensed polycyclic pigments such as aminoanthraquinone pigments, indanthrone pigments, isoindolinone pigments, quinacridone pigments, dioxazine pigments, perinone pigments, and perylene pigments. Etc. Among these, halogenated copper phthalocyanine pigments and condensed multisensitive pigments are preferably used. These organic pigments can also be used as an auxiliary coloring component of the black pigment.

A plurality of dyes having a complementary color relationship that becomes black when mixed are not particularly limited. For example, cyanine dyes, metacyanine dyes, rhodocyanine dyes, oxonol dyes, styryl dyes, base styryl dyes, benzopyran dyes Quinolidine dyes, coumarin dyes, thiazole dyes, indanthrone dyes, pyranthrone dyes, anthraquinone carbazole dyes, anthraquinone oxazole dyes, indigo, thioindigo, pyrazolone azo dyes, γ-acid azo dyes, H- Examples include acid azo dyes, triallylmethane dyes, and oxazine dyes. These dyes can also be used as an auxiliary coloring component of the black pigment.

The particle size of the light-shielding colorant is not particularly limited, but the preferred lower limit of the primary particles is 10 nm, and the preferred upper limit is 500 nm. When the particle size of the light-shielding colorant is outside this range, the dispersibility in the sealing agent for dripping method of the present invention is deteriorated.

Although content of the said light-shielding coloring agent is not specifically limited, A preferable minimum is 5 weight part and a preferable upper limit is 50 weight part with respect to 100 weight part of total weight of the sealing compound for dripping method of this invention. If the content of the light-shielding colorant is less than 5 parts by weight, sufficient light-shielding property may not be obtained, and if it exceeds 50 parts by weight, the adhesion of the sealing agent for liquid crystal dropping method of the present invention to the substrate In some cases, the strength after curing may decrease, or the drawability may decrease. The minimum with more preferable content of the said light-shielding coloring agent is 10 weight part, and a more preferable upper limit is 40 weight part.

The sealing agent for dripping method of the present invention may contain a pigment (organic pigment, inorganic pigment) or dye as an auxiliary coloring component in addition to the light-shielding colorant. For example, when the black pigment is reddish black, the light-shielding colorant can be made to exhibit a more preferable black color by adding an auxiliary coloring component that exhibits a blue color that is a complementary color of red.

The sealing agent for liquid crystal dropping method of the present invention preferably further contains a silane coupling agent. The silane coupling agent mainly serves as an adhesion aid for favorably bonding the liquid crystal dropping method sealing agent and the liquid crystal display element substrate.

Although the silane coupling agent is not particularly limited, it is excellent in the effect of improving the adhesion to a glass substrate and the like, and can be prevented from flowing into the liquid crystal by being chemically bonded to the curable resin. Propyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-isocyanatopropyltrimethoxysilane and the like are preferably used. These silane coupling agents may be used independently and 2 or more types may be used together.

The sealing agent for liquid crystal dropping method of the present invention may contain a filler for the purpose of improving adhesiveness due to stress dispersion effect, improving linear expansion coefficient, and the like.
The filler is not particularly limited. For example, talc, asbestos, silica, diatomaceous earth, smectite, bentonite, calcium carbonate, magnesium carbonate, alumina, montmorillonite, diatomaceous earth, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, water Inorganic fillers such as magnesium oxide, aluminum hydroxide, glass beads, silicon nitride, barium sulfate, gypsum, calcium silicate, talc, glass beads, sericite activated clay, bentonite, aluminum nitride, polyester fine particles, polyurethane fine particles, vinyl polymers Examples thereof include organic fillers such as fine particles and acrylic polymer fine particles.

The sealing agent for the liquid crystal dropping method of the present invention further includes a reactive diluent for adjusting the viscosity, a thixotropic agent for adjusting the thixotropy, a spacer such as a polymer bead for adjusting the panel gap, if necessary. It may contain a curing accelerator such as -P-chlorophenyl-1,1-dimethylurea, an antifoaming agent, a leveling agent, a polymerization inhibitor, and other additives.

The method for producing the sealing agent for a liquid crystal display element of the present invention is not particularly limited. For example, the resin having a (meth) acryl group, a polymer azo initiator, an additive blended as necessary, and the like. And a method of mixing by a conventionally known method.

A vertical conduction material can be produced by blending conductive fine particles with the sealant for the liquid crystal dropping method of the present invention.

The conductive fine particles are not particularly limited, and metal balls, those obtained by forming a conductive metal layer on the surface of resin fine particles, and the like can be used. Among them, the one in which the conductive metal layer is formed on the surface of the resin fine particle is preferable because the conductive connection is possible without damaging the electrode or the like due to the excellent elasticity of the resin fine particle.

The liquid crystal display element using the sealing compound for liquid crystal dropping method of the present invention and / or the vertical conduction material of the present invention is also one aspect of the present invention.

The method for producing the liquid crystal display element of the present invention includes, for example, forming a seal pattern on one of two substrates with electrodes such as an ITO thin film by screen printing, dispenser application, etc. of the liquid crystal dropping method of the present invention. Irradiating light such as ultraviolet rays to the sealing agent for the liquid crystal dropping method of the present invention, and the step of applying the liquid crystal microdrops in the frame of the seal pattern and applying the other substrate under vacuum. Examples of the method include a step of temporarily curing, and a step of heating and finally curing a seal pattern made of the sealing agent for liquid crystal dropping method of the present invention.
The liquid crystal display element using the sealing agent for liquid crystal dropping method of the present invention and / or the vertical conduction material of the present invention is also one aspect of the present invention.

The sealing agent for liquid crystal panels containing the resin having the (meth) acryl group and the polymer azo initiator is also one aspect of the present invention.
When a liquid crystal display device is manufactured by a conventional vacuum injection method, as in the case of manufacturing a liquid crystal display device by the liquid crystal dropping method, the liquid crystal panel sealing agent is not cured when liquid crystal is sealed. Contact with. At this time, when sufficient light is not irradiated to the sealing agent for liquid crystal panels, color unevenness also occurs around the sealing portion, and a liquid crystal display element having a high-quality image cannot be obtained. If the sealing agent for liquid crystal panels of this invention is used as a sealing agent when manufacturing a liquid crystal display device by a vacuum injection method, the liquid crystal display element of a high-definition image with few color irregularities can be manufactured. This is extremely effective especially in the case of a panel design that is not sufficiently irradiated with ultraviolet rays.

The sealing agent for liquid crystal panels of the present invention is a resin having an epoxy group, an epoxy thermosetting agent, a photopolymerization initiator, a light-shielding colorant, a silane coupling agent, and a filler, like the liquid crystal dropping method sealing agent of the present invention. Various additives may be contained.

According to the present invention, it is possible to provide a sealing agent for a liquid crystal dropping method capable of manufacturing a liquid crystal display element having a high quality image with little color unevenness even when the liquid crystal display element is manufactured by a dropping method. it can. Moreover, when manufacturing a liquid crystal display device by a vacuum injection system, the sealing agent for liquid crystal panels which can manufacture the liquid crystal display element of a high quality image with few color nonuniformity can be provided.

In an Example and a comparative example, it is the figure which showed typically the procedure which produces a liquid crystal display element by a liquid crystal dropping system. In an Example and a comparative example, it is the figure which showed typically the procedure which produces a liquid crystal display element by a vacuum injection system.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Synthesis of epoxy acrylate (EX-201 modified product))
120 g of EX-201 (resorcinol type epoxy resin) was dissolved in 500 mL of toluene, and 0.1 g of triphenylphosphine was added to this solution to obtain a uniform solution. To this solution, 70 g of acrylic acid was added dropwise over 2 hours with stirring under reflux, followed by further stirring under reflux for 8 hours. Next, by removing toluene, an epoxy acrylate (EX-201 modified product) in which all epoxy groups were modified to acrylic groups was obtained.

(Synthesis of partially acrylated epoxy acrylate (N-770 partially modified product))
190 g of N-770 (phenol novolac type epoxy resin) is dissolved in 500 mL of toluene, 0.1 g of triphenylphosphine is added to this solution to obtain a uniform solution, and 35 g of acrylic acid is dropped into this solution over 2 hours with stirring under reflux. Thereafter, the mixture was further stirred at reflux for 6 hours. Next, partially acrylated epoxy acrylate (N-770 partially modified product) in which 50 mol% of the epoxy group was modified to an acrylic group by removing toluene was obtained.

(Examples 1 to 10 and Comparative Examples 1 to 3)
In accordance with the mixing ratio described in Table 1, each material was mixed using a planetary stirrer (“Shinky Co., Ltd.“ Awatori Nertaro ”), and then further mixed using three rolls. The sealing agents for liquid crystal dropping method of Comparative Examples 1 to 3 were prepared.

As shown in FIG. 1, the obtained liquid crystal dropping method sealing agent is applied to a substrate on which a transparent electrode and an alignment film are formed with a dispenser so as to draw a square frame, and inside the square frame. The obtained sealing agent for liquid crystal dropping method was spotted. Subsequently, a fine droplet of liquid crystal (“JC-5004LA” manufactured by Chisso Corporation) is dropped onto the entire surface of the transparent base frame, and a substrate on which another transparent electrode and an alignment film are formed is superposed in a vacuum, and vacuum is applied. After the release, the outer frame seal part was irradiated with ultraviolet rays at 100 mW / cm ² for 30 seconds using a high-pressure mercury lamp. At this time, a mask was applied so that UV was not irradiated to the sealing agent for the liquid crystal dropping method which was dotted. Thereafter, liquid crystal annealing was performed at 120 ° C. for 1 hour, and at the same time, the sealing agent for liquid crystal dropping method was thermally cured to obtain a liquid crystal display element.

<Evaluation>
The following evaluation was performed about the sealing agent for liquid crystal dropping methods obtained in Examples 1-10 and Comparative Examples 1-3, and a liquid crystal display element. The results are shown in Table 1.

(Panel display unevenness evaluation)
About the obtained liquid crystal display element, the color nonuniformity which arises in the liquid crystal around the sealing agent for liquid crystal dropping methods which were dotted was visually observed in the energized state and the non-energized state. As a result, “◎” indicates that there is no color unevenness, “◯” indicates that there is almost no color unevenness, “△” indicates that there is slight color unevenness, and “×” indicates that there is considerable color unevenness. It was evaluated.

(Adhesive strength evaluation)
3 parts by weight of polymer beads having an average particle diameter of 5 μm (“Micropearl SP” manufactured by Sekisui Chemical Co., Ltd.) are dispersed by a planetary stirrer with respect to 100 parts by weight of the obtained liquid crystal dropping method sealing agent, to obtain a uniform liquid, A very small amount is taken in the center of Corning glass 1737 (20 mm x 50 mm x 1.1 mmt), and the same type of glass is placed on top of it to spread the sealing agent for the liquid crystal dropping method, and ultraviolet rays are applied at 100 mW / cm ² for 20 seconds. Irradiated. Thereafter, heating at 120 ° C. for 1 h was performed to obtain an adhesion test piece. The adhesive strength of this test piece was measured using a tension gauge (comparative unit is N / cm ² ).

(Examples 11 to 15 and Comparative Examples 4 to 5)
For the liquid crystal panels of Examples 11 to 15 and Comparative Examples 4 to 5 by mixing each material using a planetary stirrer (“Shintaro Awatori” manufactured by Sinky Corporation) according to the blending ratio described in Table 2. A sealant was prepared.

As shown in FIG. 2, the liquid crystal dropping method sealant of Example 1 was applied to the substrate on which the transparent electrode and the alignment film were formed with a dispenser so that a part of the square frame was interrupted, The substrate on which the transparent electrode and the alignment film were formed was overlaid and pressurized until the sealant reached a predetermined gap, and a heat treatment at 120 ° C. for 1 h was performed to obtain an empty cell before liquid crystal injection. Next, after the empty cell was evacuated, the liquid crystal ("JC-5004LA" manufactured by Chisso Corporation) was brought into contact with the part where the square frame was partially cut off, then returned to normal pressure, A cell filled with liquid crystal was obtained.

Next, after sealing the place where the part of the square frame cut off using the sealing agents of Examples 11 to 15 and Comparative Examples 4 to 5 using the obtained sealing agent for liquid crystal panels, The sealant was irradiated with ultraviolet rays at 100 mW / cm ² for 30 seconds using a high-pressure mercury lamp. Thereafter, liquid crystal annealing was performed at 120 ° C. for 1 hour, and at the same time, the sealing agent was thermally cured to obtain a liquid crystal display element. At this time, a liquid crystal display element was also obtained under the condition that the sealing agent was not irradiated with ultraviolet light and subjected to liquid crystal annealing at 120 ° C. for 1 h.

<Evaluation>
About the liquid crystal display element obtained in Examples 11-15 and Comparative Examples 4-5, the panel display nonuniformity was evaluated with the following method.
The results are shown in Table 2.

(Panel display unevenness evaluation)
About the obtained liquid crystal display element, the color nonuniformity which arises in the liquid crystal around a sealing part was observed visually in the energized state and the non-energized state. As a result, “◎” indicates that there is no color unevenness, “◯” indicates that there is almost no color unevenness, “△” indicates that there is slight color unevenness, and “×” indicates that there is considerable color unevenness. It was evaluated.

(Reference Examples 1-5)
According to the blending ratio described in Table 3, each material was mixed using a planetary stirrer (“Shinky Co., Ltd.“ Awatori Nertaro ”), and then mixed using three rolls to obtain Reference Examples 1 to 5 A liquid crystal dropping method sealing agent was prepared.

<Evaluation>
About the sealing compound for liquid crystal dropping methods obtained in Reference Examples 1-5, the OD value and curability were evaluated by the following methods. Further, panel display unevenness evaluation was performed by the same method as in the example.
The results are shown in Table 3.

(Measurement of optical density (OD value))
1 g of a silica spacer having a diameter of 5 μm (manufactured by Sekisui Chemical Co., Ltd., Micropearl SI) was added as a spacer to 100 g of the obtained liquid crystal dropping method sealing agent, and mixed and stirred.
Apply the obtained spacer-containing liquid crystal dropping method sealant onto a 50 mm x 50 mm glass substrate, overlay the same size glass substrate on the substrate, apply a load, and crush to the spacer diameter to make the thickness uniform did. Next, irradiation was performed at 100 mW / cm 2 for 30 seconds using a metal halide lamp. Thereafter, curing was performed in a 120 ° C. oven for 1 hour to obtain a measurement sample of the light shielding sealant. The optical density (OD value) of the obtained sample was measured using PDA-100 manufactured by Konica.

(Evaluation of curability)
A sample was prepared by sandwiching a sealing agent for liquid crystal dropping method between two polyethylene terephthalate films so that the sealing agent had a thickness of about 5 μm. This sample was irradiated with ultraviolet rays at 100 mW / cm ² for 30 seconds using a high-pressure mercury lamp, and then heat-treated at 120 ° C. for 1 hour. When the polyethylene terephthalate film was peeled off after heat treatment, the case where no tack remained on both sides was evaluated as “◯”, and the case where tack remained on either side was evaluated as “x”.

According to the present invention, it is possible to provide a sealing agent for a liquid crystal dropping method capable of manufacturing a liquid crystal display element having a high quality image with little color unevenness even when the liquid crystal display element is manufactured by a dropping method. it can. Moreover, when manufacturing a liquid crystal display device by a vacuum injection system, the sealing agent for liquid crystal panels which can manufacture the liquid crystal display element of a high quality image with few color nonuniformity can be provided.

Claims (9)

A sealing agent for a liquid crystal dropping method comprising a resin having a (meth) acrylic group and a polymer azo initiator. 2. The sealing agent for liquid crystal dropping method according to claim 1, wherein the polymer azo initiator has a polydimethylsiloxane unit or a polyalkylene oxide unit. Furthermore, the sealing compound for liquid crystal dropping methods of Claim 1 or 2 containing resin which has an epoxy group, and an epoxy thermosetting agent. Furthermore, the photopolymerization initiator is contained, The sealing compound for liquid crystal dropping methods of Claim 1, 2, or 3 characterized by the above-mentioned. Furthermore, the sealing agent for liquid crystal dropping methods of Claim 1, 2, 3 or 4 characterized by containing a light-shielding colorant. A vertical conduction material comprising the sealing agent for liquid crystal dropping method according to claim 1, 2, 3, 4 or 5, and conductive fine particles. A sealing agent for a liquid crystal panel comprising a resin having a (meth) acrylic group and a polymer azo initiator. A liquid crystal display device comprising the sealing agent for liquid crystal dropping method according to claim 1, 2, 3, 4 or 5, and / or the vertical conduction material according to claim 6. A liquid crystal display element comprising the sealing agent for a liquid crystal panel according to claim 7.

Images