JP6235766B1 - Sealant for liquid crystal display element, 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 display element that is excellent in storage stability and that can suppress liquid crystal contamination due to insertion into the sealing agent by liquid crystal or the sealing agent. Moreover, an object of this invention is to provide the vertical conduction material and liquid crystal display element which are manufactured using this sealing compound for liquid crystal display elements. The present invention is a sealing agent for liquid crystal display elements containing a curable resin, a thermal radical polymerization initiator, and a polymerization inhibitor, and the thermal radical polymerization initiator has a 10-hour half-life temperature of 65 ° C. or less. It is an azo compound, and the polymerization inhibitor is a sealing agent for a liquid crystal display element, which is a compound having a naphthalene skeleton or an anthracene skeleton.

Description

The present invention relates to a sealing agent for a liquid crystal display element that is excellent in storage stability and can suppress liquid crystal contamination due to insertion into a sealing agent by liquid crystal or sealing agent. Moreover, this invention relates to the vertical conduction material and liquid crystal display element which are manufactured using this sealing compound for liquid crystal display elements.

In recent years, as a method of manufacturing a liquid crystal display element such as a liquid crystal display cell, a curable resin and a light as disclosed in Patent Document 1 and Patent Document 2 from the viewpoint of shortening tact time and optimizing the amount of liquid crystal used. A liquid crystal dropping method called a dropping method using a photothermal combined curing type sealing agent containing a polymerization initiator and a thermosetting agent is used.
In the dropping method, first, a rectangular seal pattern is formed on one of the two substrates with electrodes by dispensing. Next, liquid crystal microdrops are dropped into the sealing frame of the substrate in a state where the sealing agent is uncured, the other substrate is superposed under vacuum, and the sealing portion is irradiated with light such as ultraviolet rays to perform temporary curing. Thereafter, heating is performed to perform main curing, and a liquid crystal display element is manufactured. At present, this dripping method has become the mainstream method for manufacturing liquid crystal display elements.

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 downsizing the device, a narrow frame of the liquid crystal display unit can be cited. For example, the position of the seal portion is arranged under the black matrix (hereinafter also referred to as a narrow frame design).

However, in the narrow frame design, since the sealing agent is arranged directly under the black matrix, when the dripping method is performed, the light irradiated when photocuring the sealing agent is blocked, and it is difficult for the light to reach the inside of the sealing agent. However, the conventional sealant is insufficiently cured. As described above, when the sealant is insufficiently cured, there is a problem in that the uncured sealant component is eluted in the liquid crystal and easily causes liquid crystal contamination.

Therefore, it has been studied to cure the sealant only by heat, but without temporary curing by photopolymerization, the liquid crystal flows when heated and is inserted into the sealant part in the middle of curing, and the seal pattern is broken. There is a problem that the liquid crystal is contaminated by a sealing agent that is generated or is reduced in viscosity by heating.
In particular, in recent years, as the panel is made narrower, the width of the sealing agent to be dispensed has become narrower, and the cross-sectional area of the seal after bonding has become smaller. Therefore, the seal pattern is easily broken.

In recent years, in view of energy saving and liquid crystal stability, it is desired to thermally cure the sealing agent by heating at a low temperature for a short time. As a method for curing the sealant by heating at a low temperature for a short time, it is conceivable to use a polymerization initiator or a thermosetting agent that is excellent in reactivity at a low temperature. Such a polymerization initiator or a thermosetting agent can be used. When is used, there is a problem that the sealant is inferior in storage stability.

JP 2001-133794 A International Publication No. 02/092718

An object of the present invention is to provide a sealing agent for a liquid crystal display element that is excellent in storage stability and that can suppress liquid crystal contamination due to insertion into the sealing agent by liquid crystal or the sealing agent. Moreover, an object of this invention is to provide the vertical conduction material and liquid crystal display element which are manufactured using this sealing compound for liquid crystal display elements.

The present invention is a sealing agent for a liquid crystal display element containing a curable resin, a thermal radical polymerization initiator, and a polymerization inhibitor, and the thermal radical polymerization initiator has a 10-hour half-life temperature of 65 ° C. or less. The polymerization inhibitor is a sealing agent for liquid crystal display elements, which is a compound having a naphthalene skeleton or an anthracene skeleton.
The present invention is described in detail below.

By using an azo compound having a 10-hour half-life temperature of a specific temperature or less as a thermal radical polymerization initiator in combination with a polymerization inhibitor having a specific structure, the present invention has low temperature curability and storage stability. The present inventors have found that a sealing agent for liquid crystal display elements excellent in both of the above can be obtained, and have completed the present invention. In addition, when a polymerization initiator having excellent reactivity is used, when the substrates are bonded together under reduced pressure in the manufacturing process of the liquid crystal display element, the adhesiveness may be deteriorated due to the curing of the sealing agent progressing too quickly. However, the sealing agent for liquid crystal display elements of the present invention can also prevent a decrease in adhesion when the substrates are bonded together.

The sealing agent for liquid crystal display elements of the present invention contains a thermal radical polymerization initiator.
The thermal radical polymerization initiator is an azo compound having a 10-hour half-life temperature of 65 ° C. or lower (hereinafter also referred to as “thermal radical polymerization initiator according to the present invention”). By containing the thermal radical polymerization initiator according to the present invention, the sealing agent for liquid crystal display elements of the present invention has excellent reactivity at low temperatures, and liquid crystal contamination due to insertion into the sealing agent by liquid crystal and sealing agent Can be suppressed.

The azo compound which is a thermal radical polymerization initiator according to the present invention has excellent reactivity at low temperatures when the 10-hour half-life temperature is 65 ° C. or lower.
A preferable upper limit of the 10-hour half-life temperature of the azo compound is 60 ° C, and a more preferable upper limit is 55 ° C.
Further, from the viewpoint of making the obtained sealing agent for a liquid crystal display element more excellent in storage stability, a preferable lower limit of the 10-hour half-life temperature of the azo compound is 40 ° C., and a more preferable lower limit is 45 ° C.
In the present specification, the “10-hour half-life temperature of an azo compound” means the concentration of the azo compound when a thermal decomposition reaction of the azo compound is carried out at a constant temperature for 10 hours in the presence of an inert gas. Is the temperature at which becomes half the concentration before the reaction.

The preferable lower limit of the melting point of the azo compound is 40 ° C., and the preferable upper limit is 125 ° C. When the melting point of the azo compound is within this range, the resulting sealing agent for liquid crystal display elements is more excellent in the effect of achieving both low-temperature curability and storage stability. The minimum with more preferable melting | fusing point of the said azo compound is 45 degreeC, and a more preferable upper limit is 120 degreeC.
The melting point of the azo compound can be determined by differential scanning calorimetry.

The preferable lower limit of the molecular weight of the azo compound is 100, and the preferable upper limit is 400. When the molecular weight of the azo compound is within this range, the resulting liquid crystal display element sealing agent is more excellent in the effect of achieving both low-temperature curability and storage stability. The more preferable lower limit of the molecular weight of the azo compound is 150, and the more preferable upper limit is 300.

Specifically, the thermal radical polymerization initiator according to the present invention includes 2,2′-azobis (2,4-dimethylvaleronitrile) (10-hour half-life temperature 51 ° C., melting point 45 ° C. to 70 ° C.), 2, 2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (10-hour half-life temperature 30 ° C., melting point 50 ° C. to 96 ° C.), 2,2′-azobis (isobutyronitrile) (10-hour half-life) 65 ° C., melting point 100 ° C. to 103 ° C.), 2,2′-azobis (2-methylbutyronitrile) (10 hour half-life temperature 65 ° C., melting point 48 ° C. to 52 ° C.), and dimethyl-2, It is preferably at least one selected from the group consisting of 2′-azobis (2-methylpropionate) (10-hour half-life temperature 66 ° C., melting point 22 ° C. to 28 ° C.), and 2,2′-azobis ( 2,4-Dimethyl bar More preferably Ronitoriru).

Examples of commercially available thermal radical polymerization initiators according to the present invention include V-59, V-60, V-65, V-70, and V-601 (all manufactured by Wako Pure Chemical Industries, Ltd.). Etc.

As for the content of the thermal radical polymerization initiator according to the present invention, a preferable lower limit is 0.1 part by weight and a preferable upper limit is 5 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the thermal radical polymerization initiator according to the present invention is within this range, the resulting liquid crystal display element sealing agent is more excellent in the effect of achieving both low-temperature curability and storage stability. The more preferable lower limit of the thermal radical polymerization initiator according to the present invention is 0.2 parts by weight, and the more preferable upper limit is 1 part by weight.

The sealing agent for liquid crystal display elements of this invention contains a polymerization inhibitor.
The polymerization inhibitor is a compound having a naphthalene skeleton or an anthracene skeleton (hereinafter also referred to as “polymerization inhibitor according to the present invention”). By using the polymerization inhibitor according to the present invention as the polymerization inhibitor, the sealing agent for liquid crystal display elements of the present invention maintained excellent curability by using the above-described thermal radical polymerization initiator according to the present invention. The storage stability is excellent.

Examples of the compound having a naphthalene skeleton include 1-hydroxy-4-methoxynaphthalene, ammonium 1,4-dihydroxy-2-naphthalenesulfonate, 1,4-dihydroxynaphthalene, 1,4-dihydroxy-2-naphthoic acid. Etc.
Examples of the compound having an anthracene skeleton include 9,10-dibutoxyanthracene and 9-butoxyanthracene.
Of these, the polymerization inhibitor is preferably a compound having a naphthalene skeleton, and more preferably 1-hydroxy-4-methoxynaphthalene.

The content of the polymerization inhibitor according to the present invention is preferably 0.01 parts by weight and preferably 1 part by weight with respect to 100 parts by weight of the curable resin. When the content of the polymerization inhibitor according to the present invention is within this range, the resulting sealing agent for liquid crystal display elements is more excellent in the effect of achieving both low-temperature curability and storage stability. The minimum with more preferable content of the polymerization inhibitor concerning this invention is 0.02 weight part, and a more preferable upper limit is 0.5 weight part.

The sealing agent for liquid crystal display elements of this invention contains curable resin.
The curable resin preferably contains a (meth) acrylic compound.
In the present specification, the “(meth) acryl” means acryl or methacryl, and the “(meth) acryl compound” means a compound having a (meth) acryloyl group. “Meth) acryloyl” means acryloyl or methacryloyl.

As the (meth) acrylic compound, for example, (meth) acrylic acid ester compound obtained by reacting (meth) acrylic acid with a compound having a hydroxyl group, (meth) acrylic acid and epoxy compound are reacted. Examples include epoxy (meth) acrylates obtained, urethane (meth) acrylates obtained by reacting an isocyanate compound with a (meth) acrylic acid derivative having a hydroxyl group. Of these, epoxy (meth) acrylate is preferable. The (meth) acrylic compound preferably has two or more (meth) acryloyl groups in one molecule from the viewpoint of reactivity.
In the present specification, the “(meth) acrylate” means acrylate or methacrylate, and the “epoxy (meth) acrylate” refers to all the epoxy groups in the epoxy compound and (meth) acrylic acid. It represents the reacted compound.

Among the above (meth) acrylic acid ester compounds, as monofunctional ones, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate , T-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, iso Myristyl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxy Til (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, bicyclopentenyl (meth) acrylate, benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2 -Butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, tetrahydrofur Furyl (meth) acrylate, ethyl carbitol (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, imide (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) ) Acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl 2-hydroxypropyl phthalate, 2- (meth) acrylic Examples include leuoxyethyl phosphate and glycidyl (meth) acrylate.

Moreover, as a bifunctional thing among the said (meth) acrylic acid ester compounds, for example, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexane Diol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (Meth) acrylate, polyethylene glycol di (meth) acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) ) Acrylate, poly Lopylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide-added bisphenol A di (meth) acrylate, propylene oxide-added bisphenol A di (meth) acrylate, ethylene oxide-added bisphenol F di (meth) acrylate, dimethylol Dicyclopentadienyl di (meth) acrylate, ethylene oxide modified isocyanuric acid di (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, carbonate diol di (meth) acrylate, polyether diol Di (meth) acrylate, polyester diol di (meth) acrylate, polycaprolactone diol di (meth) acrylate, polybutadiene diol (Meth) acrylate.

Further, among the above (meth) acrylic acid ester compounds, those having three or more functions include, for example, trimethylolpropane tri (meth) acrylate, ethylene oxide-added trimethylolpropane tri (meth) acrylate, propylene oxide-added trimethylolpropane tri ( (Meth) acrylate, caprolactone-modified trimethylolpropane tri (meth) acrylate, ethylene oxide-added isocyanuric acid tri (meth) acrylate, glycerin tri (meth) acrylate, propylene oxide-added glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, Tris (meth) acryloyloxyethyl phosphate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra Meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate.

Examples of the epoxy (meth) acrylate include those obtained by reacting an epoxy compound and (meth) acrylic acid in the presence of a basic catalyst according to a conventional method.

Examples of the epoxy compound that is a raw material for synthesizing the epoxy (meth) acrylate include, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and 2,2′-diallyl bisphenol A type epoxy resin. , Hydrogenated bisphenol type epoxy resin, propylene oxide added bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, phenol Novolac epoxy resin, orthocresol novolac epoxy resin, dicyclopentadiene novolac epoxy resin, biphenyl novolac epoxy resin, naphtha Ren phenol novolak type epoxy resin, glycidyl amine type epoxy resin, alkyl polyol type epoxy resin, rubber-modified epoxy resins, glycidyl ester compounds.

As what is marketed among the said bisphenol A type epoxy resins, jER828EL, jER1004 (all are the Mitsubishi Chemical company make), Epiklon 850CRP (made by DIC company), etc. are mentioned, for example.
As what is marketed among the said bisphenol F-type epoxy resins, jER806, jER4004 (all are the Mitsubishi Chemical company make) etc. are mentioned, for example.
As what is marketed among the said bisphenol S-type epoxy resins, Epicron EXA1514 (made by DIC Corporation) etc. are mentioned, for example.
As what is marketed among the said 2,2'- diallyl bisphenol A type epoxy resins, RE-810NM (made by Nippon Kayaku Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said hydrogenated bisphenol type | mold epoxy resins, Epicron EXA7015 (made by DIC Corporation) etc. are mentioned, for example.
As what is marketed among the said propylene oxide addition bisphenol A type epoxy resins, EP-4000S (made by ADEKA) etc. are mentioned, for example.
As what is marketed among the said resorcinol type epoxy resins, EX-201 (made by Nagase ChemteX Corporation) etc. are mentioned, for example.
As what is marketed among the said biphenyl type epoxy resins, jER YX-4000H (made by Mitsubishi Chemical Corporation) etc. are mentioned, for example.
As what is marketed among the said sulfide type epoxy resins, YSLV-50TE (made by Nippon Steel & Sumikin Chemical Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said diphenyl ether type epoxy resins, YSLV-80DE (made by Nippon Steel & Sumikin Chemical Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said dicyclopentadiene type epoxy resins, EP-4088S (made by ADEKA) etc. are mentioned, for example.
As what is marketed among the said naphthalene type | mold epoxy resins, Epicron HP4032, Epicron EXA-4700 (all are the products made from DIC) etc. are mentioned, for example.
As what is marketed among the said phenol novolak-type epoxy resins, Epicron N-770 (made by DIC Corporation) etc. are mentioned, for example.
As what is marketed among the said ortho cresol novolak-type epoxy resins, Epicron N-670-EXP-S (made by DIC) etc. are mentioned, for example.
As what is marketed among the said dicyclopentadiene novolak-type epoxy resins, epiclone HP7200 (made by DIC) etc. are mentioned, for example.
As what is marketed among the said biphenyl novolak-type epoxy resins, NC-3000P (made by Nippon Kayaku Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said naphthalene phenol novolak-type epoxy resins, ESN-165S (made by Nippon Steel & Sumikin Chemical Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said glycidyl amine type epoxy resins, jER630 (made by Mitsubishi Chemical Corporation), Epicron 430 (made by DIC Corporation), TETRAD-X (made by Mitsubishi Gas Chemical Co., Inc.) etc. are mentioned, for example.
Examples of commercially available alkyl polyol type epoxy resins include ZX-1542 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Epiklon 726 (manufactured by DIC Corporation), Epolite 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.), Denacol EX-611. (Manufactured by Nagase ChemteX Corporation).
Examples of commercially available rubber-modified epoxy resins include YR-450, YR-207 (all manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Epolide PB (manufactured by Daicel Corporation), and the like.
As what is marketed among the said glycidyl ester compounds, Denacol EX-147 (made by Nagase ChemteX Corporation) etc. is mentioned, for example.
Other commercially available epoxy compounds include, for example, YDC-1312, YSLV-80XY, YSLV-90CR (all manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), XAC4151 (manufactured by Asahi Kasei Co., Ltd.), jER1031, jER1032 (any And Mitsubishi Chemical Corporation), EXA-7120 (DIC Corporation), TEPIC (Nissan Chemical Corporation), and the like.

Examples of commercially available epoxy (meth) acrylates include EBECRYL860, EBECRYL3200, EBECRYL3201, EBECRYL3412, EBECRYL3600, EBECRYL3700, EBECRYL3701, EBECRYL3702, EBECRY370R ), EA-1010, EA-1020, EA-5323, EA-5520, 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 80MF Epoxy ester 3002M, Epoxy ester 3002A, 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 (all manufactured by Nagase ChemteX Corporation) and the like.

Examples of the urethane (meth) acrylate obtained by reacting a hydroxyl group-containing (meth) acrylic acid derivative with the isocyanate compound include, for example, (meth) acrylic having a hydroxyl group with respect to 1 equivalent of an isocyanate compound having two isocyanate groups. Two equivalents of the acid derivative can be obtained by reacting in the presence of a catalytic amount of a tin-based compound.

As an isocyanate compound used as the raw material of the urethane (meth) acrylate, 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 diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris (isocyanate) Phenyl) thiophosphate, tetramethylxylylene diisocyanate, 1,6,11-undecantrie Cyanate, and the like.

Examples of the isocyanate compound that is a raw material for the urethane (meth) acrylate include, for example, polyols such as ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol. Chain-extended isocyanate compounds obtained by reaction with excess isocyanate compounds can also be used.

Examples of the (meth) acrylic acid derivative having a hydroxyl group, which is a raw material for the urethane (meth) acrylate, include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth). Hydroxyalkyl mono (meth) acrylates such as acrylate and 4-hydroxybutyl (meth) acrylate, ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, polyethylene glycol Mono (meth) acrylates of dihydric alcohols such as mono (meth) acrylates or di (meth) acrylates of trivalent alcohols such as trimethylolethane, trimethylolpropane and glycerin, and bisphenol A type epoxy Epoxy (meth) acrylates such as acrylate and the like.

Examples of commercially available urethane (meth) acrylates include M-1100, M-1200, M-1210, M-1600 (all manufactured by Toagosei Co., Ltd.), EBECRYL210, EBECRYL220, EBECRYL230, EBECRYL270, EBECRYL1290, EBECRYL2220, EBECRYL4827, EBECRYL4842, EBECRYL4858, EBECRYL5129, EBECRYL6700, EBECRYL8402, EBECRYL8803, EBECRYL8804, EBECRYL8804 , Art resin N-1255, Art Resin UN-3320HB, Art Resin UN-7100, Art Resin UN-9000A, Art Resin UN-9000H (all manufactured by Negami Industrial Co., Ltd.), U-2HA, U-2PHA, U-3HA, U- 4HA, U-6H, U-6HA, U-6LPA, U-10H, U-15HA, U-108, U-108A, U-122A, U-122P, U-324A, U-340A, U-340P, U-1084A, U-2061BA, UA-340P, UA-4000, UA-4100, UA-4200, UA-4400, UA-5201P, UA-7100, UA-7200, UA-W2A (all are Shin-Nakamura Chemical Industries Manufactured by AH), AH-600, AI-600, AT-600, UA-101I, UA-101T, UA-306H, A-306I, UA-306T (all manufactured by Kyoeisha Chemical Co., Ltd.).

The said curable resin may contain an epoxy compound for the purpose of improving the adhesiveness of the sealing compound for liquid crystal display elements obtained. As said epoxy compound, the epoxy compound used as a raw material for synthesize | combining the said epoxy (meth) acrylate, a partial (meth) acryl modified epoxy resin, etc. are mentioned, for example.
In the present specification, the partial (meth) acryl-modified epoxy resin means a compound having one or more epoxy groups and (meth) acryloyl groups in one molecule, for example, two in one molecule. It can be obtained by reacting a part of the epoxy group having an epoxy group with (meth) acrylic acid.

As what is marketed among the said partial (meth) acryl modified epoxy resins, UVACURE1561 (made by Daicel Ornex) etc. are mentioned, for example.

When the sealing agent for liquid crystal display elements of the present invention contains the (meth) acrylic compound and the epoxy compound, the ratio of the (meth) acryloyl group to the epoxy group is 30:70 to 95: 5. It is preferable to blend the (meth) acrylic compound and the epoxy compound. When the ratio of the (meth) acryloyl group to the epoxy group is within this range, the resulting sealant for a liquid crystal display element is more excellent in adhesiveness while suppressing the occurrence of liquid crystal contamination.

The curable resin preferably has a hydrogen bonding unit such as —OH group, —NH— group, and —NH ₂ group from the viewpoint of suppressing liquid crystal contamination.

The sealing agent for liquid crystal display elements of the present invention may contain a photo radical polymerization initiator in addition to the above thermal radical polymerization initiator.
Examples of the photo radical polymerization initiator include benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, benzyl, thioxanthone, and the like.

Examples of commercially available photo radical polymerization initiators include IRGACURE 184, IRGACURE 369, IRGACURE 379, IRGACURE 651, IRGACURE 819, IRGACURE 907, IRGACURE 2959, IRGACURE OXE01, and Lucin TPO (both benzoin methyl ether, benzoin methyl ether) Examples include ethyl ether and benzoin isopropyl ether (both manufactured by Tokyo Chemical Industry Co., Ltd.).

The content of the photo radical polymerization initiator is preferably 0.1 parts by weight and preferably 10 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the photo radical polymerization initiator is within this range, the effect of improving the photocurability is improved without impairing the weather resistance and the like of the obtained sealing agent for liquid crystal display elements. The minimum with more preferable content of the said radical photopolymerization initiator is 0.2 weight part, and a more preferable upper limit is 8 weight part.

The sealing agent for liquid crystal display elements of the present invention may contain a thermosetting agent.
Examples of the thermosetting agent include organic acid hydrazides, imidazole derivatives, amine compounds, polyhydric phenol compounds, acid anhydrides, and the like. Among these, solid organic acid hydrazide is preferably used.

Examples of the solid organic acid hydrazide include 1,3-bis (hydrazinocarboethyl-5-isopropylhydantoin), sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, malonic acid dihydrazide, and the like. Examples thereof include Amicure VDH, Amicure UDH (all manufactured by Ajinomoto Fine Techno Co., Ltd.), SDH, IDH, ADH (all manufactured by Otsuka Chemical Co., Ltd.), MDH (manufactured by Nippon Finechem Co., Ltd.), and the like.

The content of the thermosetting agent is preferably 1 part by weight with respect to 100 parts by weight of the curable resin, and 50 parts by weight with respect to the preferable upper limit. When the content of the thermosetting agent is within this range, the thermosetting property can be further improved without deteriorating the applicability of the obtained sealing agent for liquid crystal display elements. The upper limit with more preferable content of the said thermosetting agent is 30 weight part.

The sealing agent for liquid crystal display elements of the present invention contains an inorganic filler for the purpose of improving the viscosity, improving the adhesiveness due to the stress dispersion effect, improving the linear expansion coefficient, improving the moisture permeability of the cured product, and the like. Is preferred.

Examples of the inorganic filler include silica, talc, glass beads, asbestos, gypsum, diatomaceous earth, smectite, bentonite, montmorillonite, sericite, activated clay, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, and titanium oxide. , Calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum nitride, silicon nitride, barium sulfate, calcium silicate and the like.

The minimum with preferable content of the said inorganic filler in the sealing compound for liquid crystal display elements of this invention is 10 weight%, and a preferable upper limit is 70 weight%. When the content of the filler is within this range, the effect of improving adhesiveness and the like is improved without deteriorating applicability and the like. The minimum with more preferable content of the said inorganic filler is 20 weight%, and a more preferable upper limit is 60 weight%.

It is preferable that the sealing compound for liquid crystal display elements of this invention contains a silane coupling agent. The silane coupling agent mainly has a role as an adhesion assistant for favorably bonding the sealing agent and the substrate.

As said silane coupling agent, since it is excellent in the effect which improves adhesiveness with a board | substrate etc. and it can suppress the outflow of curable resin in a liquid crystal by chemically bonding with curable resin, it is 3 for example. -Aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane and the like are preferably used.

The minimum with preferable content of the said silane coupling agent in the sealing compound for liquid crystal display elements of this invention is 0.1 weight%, and a preferable upper limit is 10 weight%. When the content of the silane coupling agent is within this range, the effect of improving the adhesiveness is suppressed while suppressing the occurrence of liquid crystal contamination. The minimum with more preferable content of the said silane coupling agent is 0.3 weight%, and a more preferable upper limit is 5 weight%.

It is preferable that the sealing compound for liquid crystal display elements of this invention contains a soft particle. Since the flexible particles serve as a barrier between the other sealing agent component and the liquid crystal when the liquid crystal display element is manufactured, the sealing agent for a liquid crystal display element of the present invention contains a liquid crystal. It is excellent in the effect of suppressing the liquid crystal contamination due to the insertion into the sealant and the sealant.

The flexible particles preferably have a maximum particle size of 100% or more of the cell gap of the liquid crystal display element and 5 to 20 μm. The flexible particles can cause spring back by using particles having a maximum particle size of 100% or more of the cell gap. However, by setting the maximum particle size of the flexible particles to 20 μm or less, a gap failure due to spring back is caused. A liquid crystal display element can be manufactured without any problem.
The cell gap of the liquid crystal display element is not limited because it varies depending on the display element, but the cell gap of a general liquid crystal display element is 2 μm to 10 μm.

The preferable lower limit of the maximum particle size of the flexible particles is 100% of the cell gap of the liquid crystal display element and 5 μm. That is, when the cell gap of the liquid crystal display element is 5 μm or less, the preferred lower limit of the maximum particle diameter of the flexible particles is 5 μm. When the cell gap of the liquid crystal display element exceeds 5 μm, the maximum particle diameter of the flexible particles is A preferred lower limit is 100% of the cell gap of the liquid crystal display element. The maximum particle diameter of the flexible particles is not less than 5 μm and 100% of the cell gap of the liquid crystal display element, which is the above lower limit value. It becomes.
In addition, from the viewpoint of suppressing a decrease in adhesiveness due to springback and a gap defect of the liquid crystal display element, a preferable upper limit of the maximum particle diameter of the flexible particles is 20 μm. A more preferable upper limit of the maximum particle size of the flexible particles is 15 μm.
Furthermore, the maximum particle diameter of the flexible particles is preferably 2.6 times or less of the cell gap from the viewpoint of suppressing a decrease in adhesion due to springback and a gap defect of the liquid crystal display element. A more preferable upper limit of the maximum particle diameter of the flexible particles is 2.2 times the cell gap, and a more preferable upper limit is 1.7 times the cell gap.
In the present specification, the maximum particle size of the flexible particles and the average particle size described below are values obtained by measuring the particles before blending with the sealant using a laser diffraction particle size distribution measuring device. means. As the laser diffraction type distribution measuring device, Mastersizer 2000 (manufactured by Malvern) or the like can be used.

In the flexible particles, the content ratio of particles having a particle diameter of 5 μm or more in the particle size distribution of the flexible particles measured by the laser diffraction type distribution measuring device is preferably 60% or more by volume frequency. When the content ratio of the particles having a particle diameter of 5 μm or more is 60% or more in terms of volume frequency, the effect of suppressing seal break and liquid crystal contamination is excellent. The content ratio of particles having a particle diameter of 5 μm or more is more preferably 80% or more.

The flexible particles contain 100% or more of the cell gap of the liquid crystal display element by 70% or more of the particle size distribution in the entire flexible particles from the viewpoint of further exerting the effect of suppressing the occurrence of seal break and liquid crystal contamination. It is preferable that the liquid crystal display element is composed only of particles having a cell gap of 100% or more.

A preferable lower limit of the average particle diameter of the flexible particles is 2 μm. When the average particle diameter of the flexible particles is 2 μm or more, the effect of suppressing seal break and liquid crystal contamination is excellent. A more preferable lower limit of the average particle diameter of the flexible particles is 4 μm.
Further, from the viewpoint of suppressing a decrease in adhesiveness due to springback and a gap defect of the liquid crystal display element, a preferable upper limit of the average particle diameter of the flexible particles is 15 μm. A more preferable upper limit of the average particle diameter of the flexible particles is 12 μm.

As the soft particles, two or more kinds of soft particles having different maximum particle diameters may be mixed and used. That is, a soft particle having a maximum particle diameter of less than 100% of the cell gap of the liquid crystal display element and a soft particle having a maximum particle diameter of 100% or more of the cell gap of the liquid crystal display element may be mixed and used.

The coefficient of variation (hereinafter also referred to as CV value) of the flexible particles is preferably 30% or less from the viewpoint of suppressing cell gap defects. The CV value of the particle diameter of the flexible particles is more preferably 28% or less.
In the present specification, the CV value of the particle diameter is a numerical value obtained by the following formula.
CV value of particle diameter (%) = (standard deviation of particle diameter / average particle diameter) × 100

Even if the above-mentioned flexible particles are those having a maximum particle size, an average particle size, or a CV value outside the above-mentioned ranges, the maximum particle size, the average particle size, or the CV value is set within the above-mentioned range by classification. Can do. In addition, flexible particles having a particle size of less than 100% of the cell gap of the liquid crystal display element do not contribute to the suppression of the occurrence of seal break and liquid crystal contamination, and may increase the thixo value when blended with a sealant. It is preferable to remove by classification.
Examples of the method for classifying the flexible particles include wet classification and dry classification. Of these, wet classification is preferable, and wet sieving classification is more preferable.

Examples of the flexible particles include silicone particles, vinyl particles, urethane particles, fluorine particles, and nitrile particles. Of these, silicone particles and vinyl particles are preferable.

The silicone-based particles are preferably silicone rubber particles from the viewpoint of dispersibility in the resin.
Examples of commercially available silicone particles include KMP-594, KMP-597, KMP-598, KMP-600, KMP-601, KMP-602 (manufactured by Shin-Etsu Silicone), Trefil E-506S. EP-9215 (manufactured by Dow Corning Toray) and the like can be classified and used. The said silicone type particle | grains may be used independently and 2 or more types may be used together.

(Meth) acrylic particles are preferably used as the vinyl particles.
The (meth) acrylic particles can be obtained by polymerizing monomers as raw materials by a known method. Specifically, for example, a method in which a monomer is suspension-polymerized in the presence of a radical polymerization initiator, and a seed particle is swollen by absorbing the monomer into a non-crosslinked seed particle in the presence of a radical polymerization initiator. And a seed polymerization method.

Examples of the monomer that is a raw material for forming the (meth) acrylic particles include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and hexyl (meth). Alkyl (meth) such as acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, etc. ) Acrylates, oxygen-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate, etc. And, (meth) nitrile and containing monomers such as acrylonitrile, trifluoromethyl (meth) acrylate, monofunctional monomer such as a fluorine-containing (meth) acrylates such as pentafluoroethyl (meth) acrylate. Among these, alkyl (meth) acrylates are preferable because the Tg of the homopolymer is low and the deformation amount when a 1 g load is applied can be increased.

Moreover, in order to give a crosslinked structure, tetramethylol methane tetra (meth) acrylate, tetramethylol methane tri (meth) acrylate, tetramethylol methane di (meth) acrylate, trimethylol propane tri (meth) acrylate, dipentaerythritol hexa ( (Meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, ( Poly) tetramethylene di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, isocyanuric acid skeleton tri (meth) It may be used polyfunctional monomers acrylate. Especially, since the molecular weight between cross-linking points is large and the deformation amount when a 1 g load is applied can be increased, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, ( Poly) tetramethylene di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 1,6-hexanediol di (meth) acrylate are preferred.

With respect to the use amount of the crosslinkable monomer, the preferable lower limit is 1% by weight and the preferable upper limit is 90% by weight in the whole monomer as a raw material for forming the (meth) acrylic particles. When the amount of the crosslinkable monomer used is 1% by weight or more, the solvent resistance is improved, and when kneaded with various sealant raw materials, problems such as swelling do not occur and it becomes easy to disperse uniformly. When the amount of the crosslinkable monomer used is 90% by weight or less, the recovery rate can be lowered, and problems such as springback are less likely to occur. A more preferable lower limit of the amount of the crosslinkable monomer used is 3% by weight, and a more preferable upper limit is 80% by weight.

In addition to these acrylic monomers, styrene monomers such as styrene and α-methylstyrene, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether, vinyl acetate, vinyl butyrate, and laurin. Acid vinyl esters such as vinyl acid and vinyl stearate, unsaturated hydrocarbons such as ethylene, propylene, isoprene and butadiene, halogen-containing monomers such as vinyl chloride, vinyl fluoride and chlorostyrene, triallyl (iso ) Using monomers such as cyanurate, triallyl trimellitate, divinylbenzene, diallylphthalate, diallylacrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane Good .

Further, as the vinyl particles, for example, polydivinylbenzene particles, polychloroprene particles, butadiene rubber particles and the like may be used.

Examples of commercially available urethane-based particles include Art Pearl (manufactured by Negami Kogyo Co., Ltd.), Dimic Beads (manufactured by Dainichi Seika Kogyo Co., Ltd.), and the like, which can be classified and used. .

From the viewpoint of suppressing a decrease in adhesiveness of the obtained sealing agent for liquid crystal display elements and a gap defect of the obtained liquid crystal display element, the preferred lower limit of the hardness of the flexible particles is 10, and the preferred upper limit is 50. The more preferable lower limit of the hardness of the soft particles is 20, and the more preferable upper limit is 40.
In addition, in this specification, the hardness of the said flexible particle means the durometer A hardness measured by the method based on JISK6253.

The preferable lower limit of the content of the flexible particles is 15% by weight with respect to the entire liquid crystal display element sealing agent. When the content of the flexible particles is 15% by weight or more, the effect of suppressing the occurrence of seal break and liquid crystal contamination is excellent. The minimum with more preferable content of the said flexible particle | grain is 20 weight%.
Further, from the viewpoint of suppressing a decrease in adhesiveness due to springback and a gap defect of the liquid crystal display element, the upper limit of the content of the flexible particles is preferably 50% by weight with respect to the entire liquid crystal display element sealing agent. The upper limit with more preferable content of the said flexible particle | grain is 40 weight%.

The sealing agent for liquid crystal display elements of the present invention may contain a light shielding agent. By containing the said light shielding agent, the sealing compound for liquid crystal display elements of this invention can be used suitably as a light shielding sealing agent.

Examples of the light-shielding agent include iron oxide, titanium black, aniline black, cyanine black, fullerene, carbon black, and resin-coated carbon black. Of these, titanium black is preferable.

The titanium black is a substance having a higher transmittance in the vicinity of the ultraviolet region, particularly for light with a wavelength of 370 to 450 nm, compared to the average transmittance for light with a wavelength of 300 to 800 nm. That is, the above-described titanium black sufficiently shields light having a wavelength in the visible light region, thereby providing a light shielding property to the sealing agent for liquid crystal display elements of the present invention, while transmitting light having a wavelength in the vicinity of the ultraviolet region. A shading agent. The light shielding agent contained in the liquid crystal display element sealant of the present invention is preferably a highly insulating material, and titanium black is also preferred as the highly insulating light shielding agent.

The above-mentioned titanium black exhibits a sufficient effect even if it is not surface-treated, but the surface is treated with an organic component such as a coupling agent, silicon oxide, titanium oxide, germanium oxide, aluminum oxide, oxidized Surface-treated titanium black such as those coated with an inorganic component such as zirconium or magnesium oxide can also be used. Especially, what is processed with the organic component is preferable at the point which can improve insulation more.
In addition, the liquid crystal display element produced using the sealing agent for liquid crystal display elements of the present invention containing the above-described titanium black as a light-shielding agent has a sufficient light-shielding property, and thus has high contrast without light leakage. A liquid crystal display element having excellent image display quality can be realized.

Examples of commercially available titanium black include 12S, 13M, 13M-C, 13R-N, 14M-C (all manufactured by Mitsubishi Materials Corporation), Tilak D (manufactured by Ako Kasei Co., Ltd.), and the like. Can be mentioned.

The preferable lower limit of the specific surface area of the titanium black is 13 m ² / g, the preferable upper limit is 30 m ² / g, the more preferable lower limit is 15 m ² / g, and the more preferable upper limit is 25 m ² / g.
Further, the preferred lower limit of the volume resistance of the titanium black is 0.5 Ω · cm, the preferred upper limit is 3 Ω · cm, the more preferred lower limit is 1 Ω · cm, and the more preferred upper limit is 2.5 Ω · cm.

Although the primary particle diameter of the said light-shielding agent will not be specifically limited if it is below the distance between the board | substrates of a liquid crystal display element, a preferable minimum is 1 nm and a preferable upper limit is 5000 nm. When the primary particle diameter of the light-shielding agent is within this range, the light-shielding property can be improved without deteriorating the applicability of the obtained sealing agent for liquid crystal display elements. The more preferable lower limit of the primary particle diameter of the light shielding agent is 5 nm, the more preferable upper limit is 200 nm, the still more preferable lower limit is 10 nm, and the still more preferable upper limit is 100 nm.
The primary particle size of the light shielding agent can be measured by using NICOMP 380ZLS (manufactured by PARTICS SIZING SYSTEMS) and dispersing the light shielding agent in a solvent (water, organic solvent, etc.).

The minimum with preferable content of the said light-shielding agent in the sealing compound for liquid crystal display elements of this invention is 5 weight%, and a preferable upper limit is 80 weight%. When the content of the light-shielding agent is within this range, the liquid crystal display element sealant can exhibit better light-shielding properties without reducing the adhesion to the substrate, the strength after curing, and the drawability. it can. The more preferable lower limit of the content of the light-shielding agent is 10% by weight, the more preferable upper limit is 70% by weight, the still more preferable lower limit is 30% by weight, and the still more preferable upper limit is 60% by weight.

The sealing agent for liquid crystal display elements of the present invention further contains additives such as a stress relieving agent, a reactive diluent, a thixotropic agent, a spacer, a curing accelerator, an antifoaming agent, and a leveling agent as necessary. May be.

As a method for producing the sealing agent for liquid crystal display elements of the present invention, for example, using a mixer such as a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, or a three roll, a curable resin and a heat Examples include a method of mixing a radical polymerization initiator, a polymerization inhibitor, and an additive such as a silane coupling agent added as necessary.

A vertical conducting material can be produced by blending conductive fine particles with the liquid crystal display element sealant of the present invention. Such a vertical conduction material containing the sealing agent for liquid crystal display elements of the present invention and conductive fine particles is also one aspect of the present invention.

As the conductive fine particles, a metal ball, a resin fine particle formed with a conductive metal layer on the surface, or the like can be used. Among them, the one in which the conductive metal layer is formed on the surface of the resin fine particles is preferable because the conductive connection is possible without damaging the transparent substrate due to the excellent elasticity of the resin fine particles.

The liquid crystal display element using the sealing agent for liquid crystal display elements of this invention or the vertical conduction material of this invention is also one of this invention.

As a method for producing the liquid crystal display element of the present invention, a liquid crystal dropping method is preferably used. Specifically, for example, the liquid crystal display element sealant of the present invention is applied to one of two substrates such as a glass substrate with electrodes such as an ITO thin film or a polyethylene terephthalate substrate by screen printing, dispenser application, or the like. A step of forming a frame-shaped seal pattern, in which the liquid crystal display element sealant of the present invention is in an uncured state, droplets of liquid crystal are dropped into the frame of the substrate seal pattern, and another substrate is stacked under vacuum. And a method including a step of combining and a step of heating and curing the sealing agent for liquid crystal dropping method of the present invention. Moreover, you may perform the process of irradiating light, such as an ultraviolet-ray, to a seal pattern part, and preliminarily hardening a sealing agent before the process of heating and hardening the sealing compound for liquid crystal dropping methods of this invention.

ADVANTAGE OF THE INVENTION According to this invention, the sealing agent for liquid crystal display elements which is excellent in storage stability and can suppress the liquid crystal contamination by the sealing agent and the insertion to the sealing agent by a liquid crystal can be provided. Moreover, according to this invention, the vertical conduction material and liquid crystal display element which are manufactured using this sealing compound for liquid crystal display elements can be provided.

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

(Examples 1-12, Comparative Examples 1-3)
According to the blending ratios described in Tables 1 to 3, each material was stirred with a planetary stirrer ("Shinky", "Awatori Netaro"), and then mixed uniformly with three ceramic rolls. The sealing agent for liquid crystal display elements of Examples 1-12 and Comparative Examples 1-3 was obtained.

<Evaluation>
The following evaluation was performed about each sealing compound for liquid crystal display elements obtained by the Example and the comparative example. The results are shown in Tables 1-3.

(1) Storage stability About each sealing agent for liquid crystal display elements obtained by the Example and the comparative example, the state after storing at 25 degreeC for 168 hours was confirmed. The storage stability of the sealant was evaluated as “◯” when gelation was not confirmed in the sealant after storage, and “x” when gelation was confirmed in the sealant after storage.
In addition, after stirring a sealing agent with a spatula, when dripping, when the fluidity fell significantly compared with before storage, it judged that it gelatinized.

(2) Curability Each sealant for a liquid crystal display element obtained in Examples and Comparative Examples was applied in a small amount on a glass substrate using a dispenser (manufactured by Musashi Engineering Co., Ltd., “SHOTMASTER300”), and a PET film was stacked thereon. Thereafter, the sealant was cured by heating at 120 ° C. for 60 minutes. However, about the sealing compound for liquid crystal display elements obtained in Example 10, after irradiating 3000 mJ / cm < ² > of ultraviolet rays with a metal halide lamp, the sealing agent was hardened by heating at 120 degreeC for 60 minutes. The spectrum of the cured product of the obtained sealing agent was measured by a microscopic IR method, the peak area of 815 to 800 cm ⁻¹ was defined as the peak area of the (meth) acryloyl group, and the peak area of 845 to 820 cm ⁻¹ was the reference peak area. As a result, the conversion ratio of the (meth) acryloyl group was calculated by the following formula. The curability was evaluated as “◯” when the conversion was 95% or more, “Δ” when it was 90% or more and less than 95%, and “X” if it was less than 90%.
Conversion rate of (meth) acryloyl group (%) = 100 × (1- (peak area of (meth) acryloyl group after UV irradiation / reference peak area after UV irradiation) / ((meth) acryloyl group before UV irradiation) Peak area / reference peak area before UV irradiation))

(3) Insertion-preventing properties Each liquid crystal display element sealant obtained in the Examples and Comparative Examples was filled in a syringe for dispensing (“PSY-10E” manufactured by Musashi Engineering Co., Ltd.) and subjected to defoaming treatment. . Next, a sealant was applied to a transparent electrode substrate with an ITO thin film in a rectangular frame using a dispenser (manufactured by Musashi Engineering Co., Ltd., “SHOTMASTER 300”). Subsequently, fine droplets of TN liquid crystal (manufactured by Chisso Corporation, “JC-5001LA”) were dropped and applied with a liquid crystal dropping device, and the other transparent substrate was bonded with a vacuum bonding device under a reduced pressure of 5 Pa. . The sealing agent was cured by heating the bonded cells at 120 ° C. for 60 minutes. However, about the sealing compound for liquid crystal display elements obtained in Example 10, after irradiating 3000 mJ / cm < ² > of ultraviolet rays with a metal halide lamp, the sealing agent was hardened by heating at 120 degreeC for 60 minutes. About the obtained liquid crystal display element, the insertion which arises in the liquid crystal (especially corner part) around a seal | sticker part was observed visually. “○” indicates that the liquid crystal has been inserted up to ¼ of the line width, and “△” indicates that the liquid crystal has been inserted up to half the line width. What was generated) was evaluated as “x” to evaluate insertion prevention.

(4) Display performance of liquid crystal display elements (low liquid crystal contamination)
Each sealing agent for liquid crystal display elements obtained in Examples and Comparative Examples was filled in a dispensing syringe (manufactured by Musashi Engineering Co., Ltd., “PSY-10E”) and subjected to defoaming treatment. Next, a sealant was applied to a transparent electrode substrate with an ITO thin film in a rectangular frame using a dispenser (manufactured by Musashi Engineering Co., Ltd., “SHOTMASTER 300”). Subsequently, fine droplets of TN liquid crystal (manufactured by Chisso Corporation, “JC-5001LA”) were dropped and applied with a liquid crystal dropping device, and the other transparent substrate was bonded with a vacuum bonding device under a reduced pressure of 5 Pa. . The sealing agent was cured by heating the bonded cells at 120 ° C. for 60 minutes. However, about the sealing compound for liquid crystal display elements obtained in Example 10, after irradiating 3000 mJ / cm < ² > of ultraviolet rays with a metal halide lamp, the sealing agent was hardened by heating at 120 degreeC for 60 minutes.
For the obtained liquid crystal display element, the display unevenness generated in the liquid crystal (especially the corner portion) around the seal portion is visually observed, and when the display unevenness is not confirmed, “○”, when the display unevenness is confirmed. The display performance (low liquid crystal contamination) of the liquid crystal display element was evaluated as “x”.

ADVANTAGE OF THE INVENTION According to this invention, the sealing agent for liquid crystal display elements which is excellent in storage stability and can suppress the liquid crystal contamination by the sealing agent and the insertion to the sealing agent by a liquid crystal can be provided. Moreover, according to this invention, the vertical conduction material and liquid crystal display element which are manufactured using this sealing compound for liquid crystal display elements can be provided.

Claims (9)

A sealing agent for a liquid crystal display element containing a curable resin, a thermal radical polymerization initiator, and a polymerization inhibitor,
The thermal radical polymerization initiator is an azo compound having a 10-hour half-life temperature of 65 ° C. or less,
The liquid crystal display element sealing agent, wherein the polymerization inhibitor is a compound having a naphthalene skeleton or an anthracene skeleton. The sealing compound for liquid crystal display elements according to claim 1, wherein the azo compound has a melting point of 40 ° C. to 125 ° C. Azo compounds include 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (isobutyro). Nitrile), 2,2′-azobis (2-methylbutyronitrile), and dimethyl-2,2′-azobis (2-methylpropionate). The sealing agent for liquid crystal display elements of Claim 1 or 2. The sealing compound for liquid crystal display elements according to claim 3, wherein the azo compound is 2,2'-azobis (2,4-dimethylvaleronitrile). The sealing agent for liquid crystal display elements according to claim 1, 2, 3, or 4, wherein the polymerization inhibitor is a compound having a naphthalene skeleton. 6. The sealing agent for liquid crystal display elements according to claim 5, wherein the polymerization inhibitor is 1-hydroxy-4-methoxynaphthalene. The light-shielding agent is contained, The sealing compound for liquid crystal display elements of Claim 1, 2, 3, 4, 5 or 6 characterized by the above-mentioned. A vertical conduction material comprising the sealing agent for a liquid crystal display element according to claim 1, 2, 3, 4, 5, 6 or 7, and conductive fine particles. A liquid crystal display element comprising the sealant for a liquid crystal display element according to claim 1, 2, 3, 4, 5, 6 or 7, or the vertical conduction material according to claim 8.