WO2018062159A1

WO2018062159A1 - Sealing agent for liquid crystal display elements, vertically conducting material and liquid crystal display element

Info

Publication number: WO2018062159A1
Application number: PCT/JP2017/034705
Authority: WO
Inventors: 秀幸林
Original assignee: 積水化学工業株式会社
Priority date: 2016-09-29
Filing date: 2017-09-26
Publication date: 2018-04-05
Also published as: KR102460034B1; CN108780249A; CN108780249B; TW201819505A; JP7000158B2; TWI745437B; JPWO2018062159A1; KR20190053132A

Abstract

One purpose of the present invention is to provide a sealing agent for liquid crystal display elements, which is capable of suppressing contamination of liquid crystals, while exhibiting excellent curability in a light-blocked part. Another purpose of the present invention is to provide: a vertically conducting material which is obtained using this sealing agent for liquid crystal display elements; and a liquid crystal display element. The present invention is a sealing agent for liquid crystal display elements, which contains a curable resin and a photopolymerization initiator, and wherein: the curable resin contains a (meth)acrylic compound and an aromatic epoxy compound; the photopolymerization initiator contains a compound represented by formula (1); and the difference between the SP value of the curable resin and the SP value of the photopolymerization initiator is 2.5 or less.

Description

Sealant for liquid crystal display element, vertical conduction material, and liquid crystal display element

The present invention relates to a sealant for a liquid crystal display element that is excellent in light-shielding part curability and can suppress liquid crystal contamination. Moreover, this invention relates to the vertical conduction material and liquid crystal display element which use 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 two transparent substrates with electrodes by dispensing. Next, a liquid crystal micro-droplet is dropped on the entire surface of the transparent substrate frame in a state where the sealant is uncured, and the other transparent substrate is immediately overlaid, and the seal portion is irradiated with light such as ultraviolet rays for temporary curing. . Thereafter, heating is performed at the time of liquid crystal annealing to perform main curing, and a liquid crystal display element is manufactured. If the substrates are bonded together under reduced pressure, a liquid crystal display element can be manufactured with extremely high efficiency, and this dripping method is currently 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 method for reducing the size of the apparatus, there is a narrow frame of the liquid crystal display unit. 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, the sealant is placed directly under the black matrix, so when the dripping method is used, the light irradiated when photocuring the sealant is blocked, and the light does not reach the inside of the sealant. There was a problem that the curing was insufficient. If the sealant is insufficiently cured in this manner, the uncured sealant component is eluted in the liquid crystal, and the curing reaction by the eluted sealant component proceeds in the liquid crystal, resulting in liquid crystal contamination. there were.
As a method for suppressing liquid crystal contamination, Patent Document 3 discloses that a highly sensitive photopolymerization initiator is blended with a sealant. However, liquid crystal contamination could not be sufficiently suppressed in the light-shielding part only by blending a highly sensitive photopolymerization initiator.

JP 2001-133794 A International Publication No. 02/092718 International Publication No. 2012/002028

An object of this invention is to provide the sealing compound for liquid crystal display elements which is excellent in sclerosis | hardenability of light-shielding part, and can suppress liquid-crystal contamination. Another object of the present invention is to provide a vertical conduction material and a liquid crystal display element using the sealing agent for a liquid crystal display element.

The present invention is a sealant for a liquid crystal display element containing a curable resin and a photopolymerization initiator, wherein the curable resin contains a (meth) acryl compound and an aromatic epoxy compound, and the photopolymerization is started. The agent is a sealing agent for liquid crystal display elements that contains a compound represented by the following formula (1) and has a SP value difference of 2.5 or less between the curable resin and the photopolymerization initiator.

The present invention is described in detail below.
The inventor considered that the reason why the light-curing portion curability could not be sufficiently improved even when a highly sensitive photopolymerization initiator was used was that the photopolymerization initiator had low solubility in the curable resin. Therefore, the present inventor uses a specific compound as a curable resin and a photopolymerization initiator in combination so that the difference in SP value is not more than a specific value, thereby providing excellent light-shielding part curability and liquid crystal contamination. It has been found that a sealing agent for liquid crystal display elements that can be suppressed can be obtained, and the present invention has been completed.

The sealing agent for liquid crystal display elements of this invention contains curable resin.
The curable resin contains a (meth) acrylic compound and an aromatic epoxy compound. By using a combination of the (meth) acrylic compound and the aromatic epoxy compound, the obtained sealing agent for liquid crystal display elements is excellent in the effect of achieving both adhesiveness and liquid crystal contamination.
In the present specification, the “(meth) acryl” means acryl or methacryl, and the “(meth) acryl compound” means a compound having a (meth) acryloyl group. The term “(meth) acryloyl group” means an acryloyl group or a methacryloyl group. In the present specification, the “aromatic epoxy compound” means a compound having an aromatic ring and an epoxy group.

Examples of the (meth) acrylic compound include (meth) acrylic acid ester compounds, epoxy (meth) acrylates, urethane (meth) acrylates, and the like. Of these, epoxy (meth) acrylate is preferable. The (meth) acrylic compound preferably has two or more (meth) acryloyl groups in the molecule because of its high 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.

Examples of the monofunctional compounds among the (meth) acrylic acid ester compounds include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and 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.

Examples of the bifunctional compound among the (meth) acrylic acid ester compounds include 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 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 as a raw material for synthesizing the epoxy (meth) acrylate include 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.

Examples of commercially available bisphenol A type epoxy resins include jER828EL, jER1004 (all manufactured by Mitsubishi Chemical Corporation), EPICLON EXA-830CRP, EPICLON EXA-850CRP (manufactured by DIC), and the like.
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, EPICLONEXA1514 (made by DIC Corporation) etc. are mentioned, for example.
Examples of commercially available 2,2′-diallylbisphenol A type epoxy resins include RE-810NM (manufactured by Nippon Kayaku Co., Ltd.).
As what is marketed among the said hydrogenated bisphenol-type epoxy resins, EPICLONEXA7015 (made by DIC Corporation) etc. are mentioned, for example.
Examples of commercially available propylene oxide-added bisphenol A type epoxy resins include EP-4000S (manufactured by ADEKA).
Examples of commercially available resorcinol type epoxy resins include EX-201 (manufactured by Nagase ChemteX Corporation).
Examples of commercially available biphenyl type epoxy resins include jER YX-4000H (manufactured by Mitsubishi Chemical Corporation).
Examples of commercially available sulfide type epoxy resins include YSLV-50TE (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.).
Examples of commercially available diphenyl ether type epoxy resins include YSLV-80DE (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.).
Examples of commercially available dicyclopentadiene type epoxy resins include EP-4088S (manufactured by ADEKA).
Examples of commercially available naphthalene type epoxy resins include EPICLONP 4032 and EPICLONEXA-4700 (both manufactured by DIC).
Examples of commercially available phenol novolak epoxy resins include EPICLONN-770 (manufactured by DIC).
Examples of commercially available ortho cresol novolac epoxy resins include EPICLONN-670-EXP-S (manufactured by DIC).
As what is marketed among the said dicyclopentadiene novolak-type epoxy resins, EPICRONHP7200 (made by DIC) etc. are mentioned, for example.
Examples of commercially available biphenyl novolac epoxy resins include NC-3000P (manufactured by Nippon Kayaku Co., Ltd.).
Examples of commercially available naphthalene phenol novolac type epoxy resins include ESN-165S (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.).
Examples of commercially available glycidylamine type epoxy resins include jER630 (manufactured by Mitsubishi Chemical Corporation), EPICLON 430 (manufactured by DIC Corporation), TETRAD-X (manufactured by Mitsubishi Gas Chemical Company), and the like.
Examples of commercially available alkyl polyol type epoxy resins include ZX-1542 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), EPICLON 726 (manufactured by DIC), Epolite 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.), Denacol EX-611 ( Nagase ChemteX Corporation).
Examples of commercially available rubber-modified epoxy resins include YR-450, YR-207 (both manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Epolide PB (manufactured by Daicel Corporation), and the like.
Examples of commercially available glycidyl ester compounds include Denacol EX-147 (manufactured by Nagase ChemteX Corporation).
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 (all Also, 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 And Denacol acrylate DA-911 (all manufactured by Nagase ChemteX Corporation).

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

Examples of the isocyanate compound include 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 (isocyanatophenyl) thiophosphate, tetramethylxylylene diene Isocyanate, 1,6,11-undecane triisocyanate and the like.

Moreover, as said isocyanate compound, the chain-extended isocyanate compound obtained by reaction with a polyol and excess isocyanate compound can also be used, for example.
Examples of the polyol include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.

Examples of the (meth) acrylic acid derivative having a hydroxyl group include hydroxyalkyl mono (meth) acrylate, mono (meth) acrylate of divalent alcohol, mono (meth) acrylate or di (meth) acrylate of trivalent alcohol. And epoxy (meth) acrylate.
Examples of the hydroxyalkyl mono (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. Can be mentioned.
Examples of the divalent alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol.
Examples of the trivalent alcohol include trimethylolethane, trimethylolpropane, and glycerin.
Examples of the epoxy (meth) acrylate include bisphenol A type epoxy acrylate.

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 Shin-Nakamura Chemical Industries AH-600, AI-600, AT-600, UA-101I, UA-101T, UA-306H, A-306I, UA-306T (all manufactured by Kyoeisha Chemical Co., Ltd.).

The preferable lower limit of the content of the (meth) acrylic compound in 100 parts by weight of the curable resin is 20 parts by weight, and the preferable upper limit is 80 parts by weight. When the content of the (meth) acrylic compound is within this range, the obtained sealing agent for liquid crystal display elements is more excellent in light-shielding part curability and low liquid crystal contamination. The minimum with more preferable content of the said (meth) acryl compound is 30 weight part, and a more preferable upper limit is 70 weight part.

As said aromatic epoxy compound, what has an aromatic ring among the epoxy compounds used as the raw material for synthesize | combining the said epoxy (meth) acrylate, the partial (meth) acryl modified epoxy compound which has an aromatic ring, etc. are mentioned, for example. It is done.
In the present specification, the partial (meth) acryl-modified epoxy compound 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.

The preferable lower limit of the content of the aromatic epoxy compound in 100 parts by weight of the curable resin is 10 parts by weight, and the preferable upper limit is 70 parts by weight. When the content of the aromatic epoxy compound is within this range, the obtained sealing agent for liquid crystal display elements is more excellent in the effect of achieving both the light-shielding part curability and the adhesiveness. The minimum with more preferable content of the said aromatic epoxy compound is 20 weight part, and a more preferable upper limit is 60 weight part.

The (meth) acrylic compound and the aromatic epoxy compound preferably have a bisphenol skeleton. When the (meth) acrylic compound and the aromatic epoxy compound have a bisphenol skeleton, the photopolymerization initiator composed of the compound represented by the formula (1) is more easily dissolved.

The curable resin preferably contains a maleimide compound.
When the curable resin contains the maleimide compound, the photopolymerization initiator composed of the compound represented by the formula (1) is more easily dissolved.
In the present invention, the maleimide compound is not included in the photopolymerization initiator but is included in the curable resin.

From the viewpoint of reactivity, the maleimide compound is preferably a polyfunctional maleimide compound having two or more maleimide groups in one molecule. The compound represented by the following formula (2) and / or the following formula (3 It is more preferable to contain the compound represented by this.

In the formula (2), R ¹ represents an alkylene group having 2 to 3 carbon atoms, and n is an integer of 2 to 40.

In the formula (3), R ² represents a divalent aliphatic group having 1 to 40 carbon atoms.

In the above formula (3), R ² preferably has 12 to 36 carbon atoms. R ² preferably has an aliphatic ring.
Specific examples of the compound represented by the above formula (3) include 1,20-bismaleimide-10,11-dioctyl-eicosane (compound represented by the following formula (4-1)), 1- Heptylenemaleimide-2-octylenemaleimide-4-octyl-5-heptylcyclohexane (compound represented by the following formula (4-2)), 1,2-dioctylenemaleimide-3-octyl-4-hexyl And cyclohexane (a compound represented by the following formula (4-3)). These can be synthesized by the method described in US Pat. No. 5,973,166.

The minimum with preferable content of the said maleimide compound in 100 weight part of said curable resin is 2 weight part, and a preferable upper limit is 20 weight part. When the content of the maleimide compound is within this range, it becomes easier to dissolve the photopolymerization initiator composed of the compound represented by the above formula (1), and the obtained sealing agent for the liquid crystal display element has light-shielding part curability. And an effect of achieving both low liquid crystal contamination. The minimum with more preferable content of the said maleimide compound is 5 weight part, and a more preferable upper limit is 15 weight part.

The said curable resin may contain other curable resins, such as an aliphatic epoxy compound, in the range which does not inhibit the objective of this invention.

A preferable upper limit of the average SP value of the entire curable resin is 24. When the average SP value of the entire curable resin is 24 or less, the photopolymerization initiator composed of the compound represented by the formula (1) is more easily dissolved. The upper limit with more preferable average SP value of the said whole curable resin is 23.8.
In the present specification, the “SP value” means a solubility parameter, and is calculated by the Fedors estimation method. The “average SP value” is an average of SP values by weight fraction.

The minimum with a preferable weight average molecular weight of the said whole curable resin is 340, and a preferable upper limit is 10,000. When the weight average molecular weight of the whole curable resin is within this range, the photopolymerization initiator composed of the compound represented by the formula (1) can be more easily dissolved. The more preferable lower limit of the weight average molecular weight of the entire curable resin is 700, and the preferable upper limit is 3000.
In the present specification, the “weight average molecular weight” is a value determined by polystyrene conversion after measurement by gel permeation chromatography (GPC). Examples of the column used when measuring the weight average molecular weight in terms of polystyrene by GPC include Shodex LF-804 (manufactured by Showa Denko).

The sealing agent for liquid crystal display elements of this invention contains a photoinitiator.
The photopolymerization initiator contains a compound represented by the formula (1). By using the compound represented by the formula (1) as the photopolymerization initiator, the sealing agent for liquid crystal display elements of the present invention has excellent light-shielding part curability.

The content of the compound represented by the above formula (1) is preferably 0.1 parts by weight and preferably 5 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the compound represented by the above formula (1) is within this range, the obtained sealing agent for liquid crystal display elements is more excellent in the effect of achieving both light-shielding part curability and low liquid crystal contamination. The minimum with more preferable content of the compound represented by the said Formula (1) is 0.5 weight part, and a more preferable upper limit is 2 weight part.

The sealing agent for liquid crystal display elements of the present invention may contain other photopolymerization initiator other than the compound represented by the above formula (1) as long as the object of the present invention is not impaired.

In the sealing agent for liquid crystal display elements of the present invention, the difference in SP value between the curable resin and the photopolymerization initiator is 2.5 or less. When the difference in SP value between the curable resin and the photopolymerization initiator is 2.5 or less, the obtained sealing agent for liquid crystal display elements is excellent in light-shielding part curability and low liquid crystal contamination. The difference in SP value between the curable resin and the photopolymerization initiator is more preferably 2.3 or less, and even more preferably 2.0 or less.
The “SP value difference” means a difference in average SP values. That is, the difference in SP value between the curable resin and the photopolymerization initiator means the difference between the average SP value of the entire curable resin and the average SP value of the entire photopolymerization initiator.

The sealing agent for liquid crystal display elements of the present invention may contain a thermal polymerization initiator.
As said thermal polymerization initiator, what consists of an azo compound, an organic peroxide etc. is mentioned, for example. Among these, an initiator made of a polymer azo compound (hereinafter also referred to as “polymer azo initiator”) is preferable.
In the present specification, the polymer azo compound means a compound having an azo group and generating a radical by heat and having a number average molecular weight of 300 or more.

The preferable lower limit of the number average molecular weight of the polymer azo compound is 1000, and the preferable upper limit is 300,000. When the number average molecular weight of the polymer azo compound is within this range, it can be easily mixed with a curable resin while suppressing liquid crystal contamination. The more preferable lower limit of the number average molecular weight of the polymer azo compound 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.
In addition, in this specification, the said number average molecular weight is a value calculated | required by polystyrene conversion by measuring with gel permeation chromatography (GPC). Examples of the column for measuring the number average molecular weight in terms of polystyrene by GPC include Shodex LF-804 (manufactured by Showa Denko KK).

Examples of the polymer azo compound include those having a structure in which a plurality of units such as polyalkylene oxide and polydimethylsiloxane are bonded via an azo group.
As the polymer azo compound having a structure in which a plurality of units such as polyalkylene oxide are bonded via the azo group, 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) Examples include polycondensates of polydimethylsiloxane having a terminal amino group.
Examples of commercially available polymer azo compounds include VPE-0201, VPE-0401, VPE-0601, VPS-0501, and VPS-1001 (all manufactured by Wako Pure Chemical Industries, Ltd.). .
Examples of thermal polymerization initiators made of azo compounds that are not polymers include V-65 and V-501 (both manufactured by Wako Pure Chemical Industries, Ltd.).

Examples of the organic peroxide include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, peroxyester, diacyl peroxide, and peroxydicarbonate.

The content of the thermal polymerization initiator is preferably 0.05 parts by weight and preferably 10 parts by weight with respect to 100 parts by weight of the curable resin. When the thermal polymerization initiator is within this range, the obtained sealing agent for liquid crystal display elements is excellent in storage stability and curability while suppressing liquid crystal contamination. The minimum with more preferable content of the said thermal-polymerization initiator is 0.1 weight part, and a more preferable upper limit is 5 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. Of these, organic acid hydrazide is preferably used.

Examples of the organic acid hydrazide include sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, malonic acid dihydrazide, and the like.
Examples of commercially available organic acid hydrazides include SDH, ADH, MDH (all manufactured by Otsuka Chemical), Amicure VDH, Amicure VDH-J, Amicure UDH, Amicure UDH-J (all Ajinomoto Fine). (Techno).

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.

From the standpoint of improving the flexibility and adhesiveness of the cured product, suppressing the elution of the sealing agent into the liquid crystal and the sealing agent for the liquid crystal display element of the present invention, It is preferable to contain soft particles.

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.

As said silicone type particle | grain, a silicone rubber particle is preferable from a dispersible viewpoint to resin.

(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 alkyl (meth) acrylates, oxygen atom-containing (meth) acrylates, nitrile-containing monomers, and fluorine-containing (meth) acrylates. Monofunctional monomers such as the like.
Examples of the alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2- Examples include ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, and isobornyl (meth) acrylate.
Examples of the oxygen atom-containing (meth) acrylates include 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate, and the like.
Examples of the nitrile-containing monomer include (meth) acrylonitrile.
Examples of the fluorine-containing (meth) acrylates include trifluoromethyl (meth) acrylate and 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 a crosslinkable monomer 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 other sealant components, it does not cause problems such as swelling and is easily dispersed uniformly. . When the amount of the crosslinkable monomer used is 90% by weight or less, the recovery rate can be lowered. 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, vinyl ethers, carboxylic acid vinyl esters, unsaturated hydrocarbons, halogen-containing monomers, triallyl cyanurate, triallyl isocyanurate, Monomers such as triallyl trimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, vinyltrimethoxysilane may be used.
Examples of the styrene monomer include styrene, α-methylstyrene, trimethoxysilylstyrene, and the like.
Examples of the vinyl ethers include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, and the like.
Examples of the carboxylic acid vinyl esters include vinyl acetate, vinyl butyrate, vinyl laurate, and vinyl stearate.
Examples of the unsaturated hydrocarbon include ethylene, propylene, isoprene, butadiene and the like.
Examples of the halogen-containing monomer include vinyl chloride, vinyl fluoride, chlorostyrene, and the like.

As the (meth) acrylic particles, core-shell (meth) acrylate copolymer fine particles are also preferably used.
Examples of commercially available core-shell (meth) acrylate copolymer fine particles include F351 (manufactured by Zeon Kasei Co., Ltd.).

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

The preferable lower limit of the average particle diameter of the flexible particles is 0.01 μm, and the preferable upper limit is 10 μm. When the average particle diameter of the flexible particles is within this range, the effect of improving the flexibility and adhesiveness of the cured product of the obtained sealing agent for liquid crystal display elements is excellent. The more preferable lower limit of the average particle diameter of the flexible particles is 0.1 μm, and the more preferable upper limit is 8 μm.
In addition, in this specification, the average particle diameter of the said flexible particle means the value obtained by measuring using the laser diffraction type particle size distribution measuring apparatus about the particle | grains before mix | blending with a sealing compound. As the laser diffraction particle size distribution measuring device, Mastersizer 2000 (manufactured by Malvern) or the like can be used.

The preferable lower limit of the hardness of the flexible particles is 10, and the preferable upper limit is 50. When the hardness of the flexible particles is in this range, the effect of improving the flexibility and adhesiveness of the cured product of the obtained sealing agent for liquid crystal display elements is improved. 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 in 100 parts by weight of the sealing agent for liquid crystal display elements of the present invention is 5 parts by weight, and the preferable upper limit is 50 parts by weight. When the content of the flexible particles is within this range, the effect of improving the flexibility and adhesiveness of the cured product of the obtained sealing agent for liquid crystal display elements is improved. The minimum with more preferable content of the said flexible particle | grain is 10 weight part, and a more preferable upper limit is 30 weight part.

The sealing agent for liquid crystal display elements of the present invention preferably contains a filler for the purpose of improving the viscosity, improving the adhesiveness due to the stress dispersion effect, improving the linear expansion coefficient, and the like.

Examples of the filler include inorganic fillers and organic fillers other than those contained in the flexible particles.
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 preferable lower limit of the content of the filler in 100 parts by weight of the sealant for liquid crystal display elements of the present invention is 10 parts by weight, and the preferable upper limit is 70 parts by 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 filler is 20 weight part, and a more preferable upper limit is 60 weight part.

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 the silane coupling agent, for example, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane and the like are preferably used. These are excellent in the effect of improving the adhesion to a substrate or the like, and can suppress the outflow of the curable resin into the liquid crystal by chemically bonding with the curable resin. These silane coupling agents may be used alone or in combination of two or more.

The minimum with preferable content of the said silane coupling agent in 100 weight part of sealing compounds for liquid crystal display elements of this invention is 0.1 weight part, and a preferable upper limit is 10 weight part. 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 part, and a more preferable upper limit is 5 weight part.

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 preferred because of its high insulating properties.

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.

The primary particle diameter of the light-shielding agent is not particularly limited as long as it is not more than the distance between the substrates of the liquid crystal display element, but the preferred lower limit is 1 nm and the preferred upper limit is 5 μm. 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 preferable lower limit of the content of the light-shielding agent in 100 parts by weight of the sealant for liquid crystal display elements of the present invention is 5 parts by weight, and the preferable upper limit is 80 parts by 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 parts by weight, the more preferable upper limit is 70 parts by weight, the still more preferable lower limit is 30 parts by weight, and the still more preferable upper limit is 60 parts by weight.

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, a light Examples thereof include a method of mixing a polymerization initiator 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. Specific examples include a method having the following steps.
First, the liquid crystal display element sealant of the present invention is applied to one of two substrates such as a glass substrate or a polyethylene terephthalate substrate with an electrode such as an ITO thin film by screen printing, dispenser application, etc. The step of forming the seal pattern is performed. Next, in a state where the sealant for a liquid crystal display element of the present invention is uncured, a step of applying droplets of liquid crystals into the frame of the seal pattern of the substrate and superimposing another substrate under vacuum is performed. Then, a liquid crystal display element can be obtained by the method of irradiating light, such as an ultraviolet-ray, to the seal pattern part of the sealing agent for liquid crystal display elements of this invention, and photocuring a sealing agent. In addition to the step of photocuring the sealant, a step of heating and thermosetting the sealant may be performed.

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal display elements which is excellent in light-shielding part curability and can suppress liquid-crystal contamination can be provided. Moreover, according to this invention, the vertical conduction material and liquid crystal display element which use 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.

(Synthesis of bisphenol A type epoxy acrylate oligomer)
170 g (0.5 mol) of bisphenol A type epoxy resin, 86.5 g (1.2 mol) of acrylic acid, 2.6 g (0.01 mol) of triphenylphosphine in a four-necked flask equipped with a cooling tube and stirring blades, and Dibutylhydroxytoluene 0.2 g (0.001 mol) was added and stirred in an oil bath at 120 ° C. for 12 hours. As the bisphenol A type epoxy resin, a reagent manufactured by DIC was used. As the acrylic acid, a reagent manufactured by Tokyo Chemical Industry Co., Ltd. was used. As the triphenylphosphine, a reagent manufactured by Tokyo Chemical Industry Co., Ltd. was used. As the dibutylhydroxytoluene, a reagent manufactured by Tokyo Chemical Industry Co., Ltd. was used.
After completion of the reaction, washing with distilled water, vacuum drying, and filtration were performed to obtain a bisphenol A type epoxy acrylate oligomer (molecular weight 4500, dispersity 2.5).
The structure of the obtained bisphenol A type epoxy acrylate oligomer was confirmed by ¹ H-NMR and GC-Ms.

(Synthesis of bisphenol A type epoxy methacrylate oligomer)
170 g (0.5 mol) of bisphenol A type epoxy resin, 103.3 g (1.2 mol) of methacrylic acid, 2.6 g (0.01 mol) of triphenylphosphine, Dibutylhydroxytoluene 0.2 g (0.001 mol) was added and stirred in an oil bath at 120 ° C. for 12 hours. As the bisphenol A type epoxy resin, a reagent manufactured by DIC was used. As the methacrylic acid, a reagent manufactured by Tokyo Chemical Industry Co., Ltd. was used. As the triphenylphosphine, a reagent manufactured by Tokyo Chemical Industry Co., Ltd. was used. As the dibutylhydroxytoluene, a reagent manufactured by Tokyo Chemical Industry Co., Ltd. was used.
After completion of the reaction, washing with distilled water, vacuum drying, and filtration were performed to obtain a bisphenol A type epoxy methacrylate oligomer (molecular weight 3200, dispersity 2.2).
The structure of the obtained bisphenol A type epoxy methacrylate oligomer was confirmed by ¹ H-NMR and GC-Ms.

(Examples 1 to 12, Comparative Examples 1 to 5)
According to the blending ratios listed in Tables 1 to 3, each material was mixed using a planetary stirrer (“Shinky Co.,“ Awatori Nertaro ”), and then mixed using three rolls. Sealants for liquid crystal display elements of Examples 1 to 12 and Comparative Examples 1 to 5 were prepared.

<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.

(Solubility of photopolymerization initiator)
About each sealing agent for liquid crystal display elements obtained by the Example and the comparative example, 2 g of photoinitiators used by each sealing agent are put into 100 g of curable resin used by each sealing agent, and it heats in 120 degreeC oven. did. When fully dissolved in less than 5 minutes from the start of heating, “XX”, when completely dissolved in 5 minutes to less than 10 minutes “○○”, when completely dissolved in 10 minutes to less than 30 minutes "○", the solubility of the photopolymerization initiator was evaluated as "△" when the residue was dissolved but "△" when the residue was not dissolved and "X" when it was not dissolved at all even after 30 minutes. .

(Light-shielding part curability)
First, a substrate A on which half of a Corning glass having a thickness of 0.7 mm was vapor-deposited and a substrate B on which the front surface was vapor-deposited were prepared. Next, 1 part by weight of spacer particles having an average particle diameter of 5 μm (manufactured by Sekisui Chemical Co., Ltd., “Micropearl SI-H050”) with respect to 100 parts by weight of the sealant for each liquid crystal display device obtained in Examples and Comparative Examples. Was uniformly dispersed by a planetary stirrer. Next, the sealing agent in which the spacer particles are dispersed is applied to the central portion of the substrate A (the boundary between the chromium vapor-deposited portion and the non-vapor-deposited portion), and after the substrate B is bonded together, the sealant is sufficiently crushed. A 100 mW / cm ² ultraviolet ray was irradiated for 30 seconds from the side using a metal halide lamp.
Thereafter, the substrates A and B are peeled off using a cutter, and the spectrum is measured by a microscopic IR method for the sealant on a point 50 μm away from the direct ultraviolet irradiation part (the part shielded from light by chromium vapor deposition). The conversion rate of the inside (meth) acryloyl group was calculated | required with the following method. That is, the conversion ratio of the (meth) acryloyl group was calculated by the following formula, with the peak area of 815 to 800 cm ^{−1 as} the peak area of the (meth) acryloyl group and the peak area of 845 to 820 cm ⁻¹ as the reference peak area. A light shielding part where the conversion rate of the (meth) acryloyl group was 80% or more, “◯”, the case of 30% or more and less than 80% was “Δ”, and the case of less than 30% was “X”. The curability was evaluated.
Conversion rate of (meth) acryloyl group = (1- (peak area of (meth) acryloyl group after UV irradiation / reference peak area after UV irradiation) / (peak area of (meth) acryloyl group before UV irradiation / ultraviolet light) Reference peak area before irradiation)) x 100

(Display performance of liquid crystal display elements (low liquid crystal contamination))
One part by weight of spacer particles (Sekisui Chemical Co., Ltd., “Micropearl SI-H050”) having an average particle size of 5 μm is used for 100 parts by weight of each liquid crystal display element sealing agent obtained in Examples and Comparative Examples. It was uniformly dispersed by a stirrer. Next, the sealing agent in which the spacer fine particles are dispersed is filled in a dispensing syringe (“PSY-10E” manufactured by Musashi Engineering Co., Ltd.) and defoamed, and then a dispenser (“SHOTMASTER 300” manufactured by Musashi Engineering Co., Ltd.). ), A sealing agent was applied in a frame shape to one of the two transparent electrode substrates with an ITO thin film. Subsequently, fine droplets of TN liquid crystal (manufactured by Chisso Corporation, “JC-5001LA”) are applied dropwise to the frame of the sealing agent with a liquid crystal dropping device, and the other transparent electrode substrate is 5 Pa with a vacuum bonding device. Bonding was performed under vacuum to obtain a cell. The obtained cell was irradiated with 100 mW / cm ² of ultraviolet rays for 30 seconds using a metal halide lamp, and then heated at 120 ° C. for 1 hour to cure the sealant to obtain a liquid crystal display element.
For the obtained liquid crystal display element, visually observe the liquid crystal (especially the corner) around the seal, and if no display irregularities or line afterimages were confirmed, “○”, clearly confirm display irregularities and line afterimages. The display performance (low liquid crystal contamination) of the liquid crystal display element was evaluated with “Δ” as the case where it was observed and “X” when the severe display unevenness or line afterimage was confirmed.

Claims

A sealing agent for a liquid crystal display element containing a curable resin and a photopolymerization initiator,
The curable resin contains a (meth) acrylic compound and an aromatic epoxy compound,
The photopolymerization initiator contains a compound represented by the following formula (1),
A sealant for a liquid crystal display element, wherein a difference in SP value between the curable resin and the photopolymerization initiator is 2.5 or less.
The sealing agent for liquid crystal display elements according to claim 1, wherein the (meth) acrylic compound and the aromatic epoxy compound have a bisphenol skeleton.
The sealing agent for liquid crystal display elements according to claim 1, wherein the curable resin contains a maleimide compound.
The sealing compound for liquid crystal display elements according to claim 3, comprising a compound represented by the following formula (2) and / or a compound represented by the following formula (3) as the maleimide compound.

In the formula (2), R 1 represents an alkylene group having 2 to 3 carbon atoms, and n is an integer of 2 to 40.

In the formula (3), R 2 represents a divalent aliphatic group having 1 to 40 carbon atoms.
5. The sealing agent for liquid crystal display elements according to claim 1, wherein the average SP value of the entire curable resin is 24 or less.
6. The sealant for a liquid crystal display element according to claim 1, wherein the entire curable resin has a weight average molecular weight of 340 to 10,000.
A vertical conduction material comprising the liquid crystal display element sealing agent according to claim 1, 2, 3, 4, 5 or 6, and conductive fine particles.
A liquid crystal display element comprising the sealing agent for a liquid crystal display element according to claim 1, 2, 3, 4, 5 or 6, or the vertical conduction material according to claim 7.