WO2016181840A1

WO2016181840A1 - Sealant for liquid crystal display element, vertical conduction material, and liquid crystal display element

Info

Publication number: WO2016181840A1
Application number: PCT/JP2016/063185
Authority: WO
Inventors: 秀幸林
Original assignee: 積水化学工業株式会社
Priority date: 2015-05-08
Filing date: 2016-04-27
Publication date: 2016-11-17
Also published as: TWI695867B; JP6046866B1; JPWO2016181840A1; TW201702321A; CN106796376A; KR20180003527A

Abstract

The present invention provides a sealant for a liquid crystal display element, the sealant having excellent curability in a light-shielding part, having excellent moisture resistance and adhesion even in an environment of high temperature and humidity, and being capable of suppressing unevenness of display in a liquid crystal display element. The purpose of the present invention is also to provide a vertical conduction material and a liquid crystal display element manufactured using the sealant for a liquid crystal display element. The present invention is a sealant for a liquid crystal display element, containing a curable resin and a thermal radical polymerization initiator, the curable resin containing a compound having two or more acryloyl groups in each molecule thereof, and a compound having two or more methacryloyl groups in each molecule thereof.

Description

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

The present invention relates to a sealing agent for a liquid crystal display element that has excellent light-shielding part curability, has excellent moisture resistance and adhesiveness even in a high-temperature and high-humidity environment, and can suppress the occurrence of display unevenness in a liquid crystal display element. . 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, a method for manufacturing a liquid crystal display element such as a liquid crystal display cell has been disclosed in, for example, Patent Document 1 and Patent Document 2 from the conventional vacuum injection method from the viewpoint of shortening tact time and optimizing the amount of liquid crystal used. A liquid crystal dropping method called a dripping method using such a photothermal combined curing type sealant has become the mainstream.

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 with the sealant being uncured, and the other transparent substrate is immediately overlaid, and the seal portion is irradiated with light such as ultraviolet rays to perform 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.

By the way, in the present age when mobile devices with various liquid crystal panels such as mobile phones and portable game machines are widespread, downsizing of devices is the most demanded issue. As a technique for miniaturization, there is a narrow frame of the liquid crystal display unit, and for example, the position of the seal portion is arranged under the black matrix (hereinafter also referred to as “narrow frame design”).
However, when a liquid crystal display element with a narrow frame design is manufactured by the dropping method, there are places where the light does not hit the seal part due to the black matrix, so when using a photo-curing sealant, it is not sufficiently irradiated with light and cured. There is a problem that a portion where the liquid crystal does not proceed occurs, the sealing agent in the middle of curing is eluted, and the liquid crystal may be contaminated.

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

The present invention provides a sealing agent for a liquid crystal display element that has excellent light-shielding part curability, has excellent moisture resistance and adhesiveness even in a high-temperature and high-humidity environment, and can suppress the occurrence of display unevenness in a liquid crystal display element. The purpose is to provide. 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 liquid crystal display element sealing agent containing a curable resin and a thermal radical polymerization initiator, wherein the curable resin is a compound having two or more acryloyl groups in one molecule and one molecule. And a compound having two or more methacryloyl groups.
The present invention is described in detail below.

The inventor of the present invention studied to suppress liquid crystal contamination caused by elution of the sealing agent in the middle of the liquid crystal by mixing a thermal radical polymerization initiator in the sealing agent and quickly curing the curable resin. However, even when a thermal radical polymerization initiator is used, if the light shielding design is severe, the crosslinking density of the light shielding part is not sufficient, resulting in insufficient moisture resistance and adhesion in a high temperature and high humidity environment, resulting in high temperature and high humidity. There has been a problem that display unevenness may occur in the liquid crystal display element after storage in an environment.
Thus, as a result of intensive studies, the present inventors have found that a sealing agent containing a thermal radical polymerization initiator has a compound having two or more acryloyl groups in one molecule as a curable resin and two or more methacryloyl groups in one molecule. By using a compound, the glass transition temperature of the cured product can be made to be a specific temperature or more, it has excellent light-shielding part curability, and has excellent moisture resistance and adhesiveness even in a high temperature and high humidity environment. As a result, it has been found that display unevenness of the liquid crystal display element can be suppressed, 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 compound having two or more acryloyl groups in one molecule and a compound having two or more methacryloyl groups in one molecule.
Hereinafter, the compound having two or more acryloyl groups in one molecule and the compound having two or more methacryloyl groups in one molecule are also referred to as a poly (meth) acrylic compound.
In the present specification, the “(meth) acryl” means acryl or methacryl.

As said poly (meth) acrylic compound, (meth) acrylic acid ester compound obtained by making the compound which has a hydroxyl group react with (meth) acrylic acid, for example, making (meth) acrylic acid and an epoxy compound react. Epoxy (meth) acrylate obtained by the above, urethane (meth) acrylate obtained by reacting an isocyanate compound with a (meth) acrylic acid derivative having a hydroxyl group, and two (meth) acryloyl groups in one molecule The compound which has the above is mentioned.
The “(meth) acrylate” means acrylate or methacrylate, and the “epoxy (meth) acrylate” means a compound obtained by reacting all epoxy groups in the epoxy compound with (meth) acrylic acid. The above “(meth) acryloyl” means acryloyl or methacryloyl.

Examples of the bifunctional one of the (meth) acrylic acid ester compounds include 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 1,6-hexanediol diene. (Meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di (meth) acrylate , Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate , Polypropy Glycol (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 , Neopentyl glycol di (meth) acrylate, ethylene oxide modified isocyanuric acid di (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, carbonate diol di (meth) acrylate, polyether diol di (Meth) acrylate, polyester diol di (meth) acrylate, polycaprolactone diol di (meth) acrylate, polybutadiene diol di (meth) Acrylate, and the like.

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, pentaerythritol tri (meth) acrylate, ethylene oxide-added isocyanuric acid tri (meth) acrylate, glycerol tri (meth) acrylate, propylene oxide-added glycerol 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 resin, glycidyl ester compounds, bisphenol A type episulfide resins.

As what is marketed among the said bisphenol A type epoxy resins, jER828EL, jER1001, jER1004 (all are the Mitsubishi Chemical company make), Epicron 850 (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.
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 | mold epoxy resins, Epicron EXA7015 (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 Epicron HP4032, Epicron EXA-4700 (both manufactured by DIC) and the like.
Examples of commercially available phenol novolac epoxy resins include Epicron N-770 (manufactured by DIC).
Examples of the ortho-cresol novolac type epoxy resin that are commercially available include epiclone N-670-EXP-S (manufactured by DIC).
As what is marketed among the said dicyclopentadiene novolak-type epoxy resins, epiclone HP7200 (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), Epicron 430 (manufactured by DIC), and TETRAD-X (manufactured by Mitsubishi Gas Chemical).
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), 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 (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).
Examples of commercially available bisphenol A type episulfide resins include jER YL-7000 (manufactured by Mitsubishi Chemical 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 used as a raw material for the urethane (meth) acrylate 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 (isocyanate) Phenyl) thiophosphate, tetramethylxylene diisocyanate, 1,6,11-undecanetriiso Aneto and the like.

The isocyanate compound is obtained by, for example, reacting a polyol such as ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, polycaprolactone diol and an excess isocyanate compound. It is also possible to use chain-extended isocyanate compounds.

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

Examples of commercially available urethane (meth) acrylates include M-1100, M-1200, M-1210, M-1600 (all manufactured by Toagosei Co., Ltd.), EBECRYL230, EBECRYL270, EBECRYL4858, EBECRYL8402, EBECRYL8804, EBECRYL8803, EBECRYL8807, EBECRYL9260, EBECRYL1290, EBECRYL5129, EBECRYL4842, EBECRYL210, EBECRYL4827, EBECRYL6700, EBECRYL6700, EBECRYL6700 , Art resin N-1255, Art Resin UN-330, Art Resin UN-3320HB, Art Resin UN-1200TPK, Art Resin SH-500B (all manufactured by Negami Industrial Co., Ltd.), U-2HA, U-2PHA, U-3HA, U- 4HA, U-6H, U-6LPA, U-6HA, U-10H, U-15HA, U-122A, U-122P, U-108, U-108A, U-324A, U-340A, U-340P, U-1084A, U-2061BA, UA-340P, UA-4100, UA-4000, UA-4200, UA-4400, UA-5201P, UA-7100, UA-7200, UA-W2A (all Shin-Nakamura Chemical Industries Manufactured by Co., Ltd.), AI-600, AH-600, AT-600, UA-101I, UA-101T, UA-306H, A-306I, UA-306T (all manufactured by Kyoeisha Chemical Co., Ltd.).

The poly (meth) acrylic compound preferably has a hydrogen-bonding unit such as —OH group, —NH— group, and —NH ₂ group from the viewpoint of suppressing adverse effects on the liquid crystal.

The curable resin is a bisphenol A type epoxy (meth) acrylate, bisphenol E type epoxy (meth) acrylate, bisphenol F type epoxy (meth) acrylate, or bisphenol S type epoxy (meth) as a poly (meth) acrylic compound. It is preferable to contain at least one selected from the group consisting of acrylates.

The minimum with the preferable ratio of the methacryloyl group with respect to the total amount of the acryloyl group and the methacryloyl group in the said whole curable resin is 5 mol%. When the ratio of the methacryloyl group is 5 mol% or more, the obtained sealing agent for liquid crystal display elements is more excellent in the effect of suppressing display unevenness of the liquid crystal display elements after storage in a high temperature and high humidity environment. . A more preferable lower limit of the ratio of the methacryloyl group is 10 mol%.
From the viewpoint of adhesiveness and the like, the preferable upper limit of the ratio of the methacryloyl group is 80 mol%, and the more preferable upper limit is 70 mol%.

The preferable lower limit of the content of the compound having two or more acryloyl groups in one molecule in 100 parts by weight of the entire curable resin is 5 parts by weight, and the preferable upper limit is 70 parts by weight. When the content of the compound having two or more acryloyl groups in one molecule is within this range, the obtained sealing agent for liquid crystal display elements is stored in a high temperature and high humidity environment while maintaining excellent adhesiveness. The resulting liquid crystal display element is more excellent in the effect of suppressing display unevenness. The more preferable lower limit of the content of the compound having two or more acryloyl groups in one molecule is 20 parts by weight, and the more preferable upper limit is 60 parts by weight.

The preferable lower limit of the content of the compound having two or more methacryloyl groups in one molecule in 100 parts by weight of the entire curable resin is 1 part by weight, and the preferable upper limit is 75 parts by weight. When the content of the compound having two or more methacryloyl groups in one molecule is within this range, the obtained sealing agent for liquid crystal display elements is stored in a high temperature and high humidity environment while maintaining excellent adhesiveness. The resulting liquid crystal display element is more excellent in the effect of suppressing display unevenness. The more preferable lower limit of the content of the compound having two or more methacryloyl groups in one molecule is 5 parts by weight, the more preferable upper limit is 60 parts by weight, the still more preferable lower limit is 20 parts by weight, and the still more preferable upper limit is 50 parts by weight. .

The said curable resin may contain a monofunctional (meth) acryl compound in the range which does not inhibit the objective of this invention.
Moreover, the said curable resin may contain an epoxy compound in the range which does not inhibit the objective of this invention for the purpose of improving the adhesiveness of the sealing compound for liquid crystal display elements obtained.
Examples of the epoxy compound include an epoxy compound that is a raw material for synthesizing the epoxy (meth) acrylate and a portion having one or more epoxy groups and one (meth) acryloyl group in one molecule (meta ) Acrylic modified epoxy resin and the like. Especially, it is preferable that the said curable resin contains the partial (meth) acryl modified | denatured epoxy resin which has one or more epoxy groups and one (meth) acryloyl group in 1 molecule.

When the said epoxy compound is contained as said curable resin, the upper limit with the preferable ratio of the epoxy group with respect to the total amount of the acryloyl group in the whole said curable resin, a methacryloyl group, and an epoxy group is 50 mol%. When the ratio of the epoxy group is 50 mol% or less, liquid crystal contamination due to dissolution of the obtained sealing agent for liquid crystal display elements in the liquid crystal can be suppressed, and the obtained liquid crystal display element is superior in display performance. It becomes. A more preferable upper limit of the ratio of the epoxy group is 20 mol%.

When the curable resin contains a partial (meth) acryl-modified epoxy resin having one or more epoxy groups and one (meth) acryloyl group in one molecule, in 100 parts by weight of the curable resin as a whole. The preferable lower limit of the content of the partial (meth) acryl-modified epoxy resin in is 3 parts by weight, and the preferable upper limit is 50 parts by weight. By using the partial (meth) acryl-modified epoxy resin in this range, the obtained sealing agent for liquid crystal display elements is excellent in adhesiveness and excellent in suppressing the occurrence of display unevenness in the obtained liquid crystal display elements. It will be a thing. The minimum with more preferable content of the said partial (meth) acryl modified epoxy resin is 5 weight part, and a more preferable upper limit is 40 weight part.

The sealing agent for liquid crystal display elements of the present invention contains a thermal radical polymerization initiator.
As said thermal radical 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 initiator is an azo group, and generates a radical that can react with a radical polymerizable group such as a (meth) acryloyl group by heat, and has a number average molecular weight of 300 or more. Means a compound of

The preferable lower limit of the number average molecular weight of the polymeric azo initiator is 1000, and the preferable upper limit is 300,000. When the number average molecular weight of the polymeric azo initiator is within this range, it can be more easily mixed into the curable resin while preventing adverse effects on the liquid crystal. The more preferable lower limit of the number average molecular weight of the polymeric azo initiator is 5000, the more preferable upper limit is 100,000, the still more preferable lower limit is 10,000, and the still more preferable upper limit is 90,000.
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 initiator 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 initiator 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 thereof include polycondensates of polydimethylsiloxane having a terminal amino group, such as VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001 (all of which are Wako Pure Chemical Industries, Ltd.) Manufactured) and the like.
Examples of azo compounds that are not a polymer 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 radical 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 content of the thermal radical polymerization initiator is within this range, the liquid crystal display element sealant obtained is more excellent in thermosetting while suppressing liquid crystal contamination by the unreacted thermal radical polymerization initiator. . The minimum with more preferable content of the said thermal radical polymerization initiator is 0.1 weight part, and a more preferable upper limit is 5 weight part.

The content of the thermal radical polymerization initiator in the sealing agent for liquid crystal display elements of the present invention 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 thermal radical polymerization initiator is 0.1 parts by weight or more, the obtained sealing agent for liquid crystal display elements is more excellent in thermosetting. When the content of the thermal radical polymerization initiator is 10 parts by weight or less, the viscosity of the obtained sealing agent for liquid crystal display elements does not become too high, and the coating properties and the like are excellent. The minimum with more preferable content of the said thermal radical polymerization initiator is 0.15 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 photo radical polymerization initiator in addition to the 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, all manufactured by Rusilin TPO ), Benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.) and the like.

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 0.1 parts by weight or more, the obtained sealing agent for liquid crystal display elements is more excellent in photocurability. When the content of the radical photopolymerization initiator is 10 parts by weight or less, a large amount of unreacted radical photopolymerization initiator does not remain, and the resulting sealant for a liquid crystal display element has superior weather resistance. 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 1 part by weight or more, the obtained sealing agent for liquid crystal display elements is more excellent in thermosetting. When the content of the thermosetting agent is 50 parts by weight or less, the viscosity of the obtained sealing agent does not become too high, and the coating property is excellent. 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 may contain a filler for the purpose of improving the viscosity, improving the adhesiveness due to the stress dispersion effect, improving the linear expansion coefficient, and further improving the moisture resistance of the cured product. Good.

Examples of the filler include talc, asbestos, silica, diatomaceous earth, smectite, bentonite, calcium carbonate, magnesium carbonate, alumina, montmorillonite, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, water Inorganic fillers such as aluminum oxide, glass beads, silicon nitride, barium sulfate, gypsum, calcium silicate, sericite, activated clay, aluminum nitride, polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, acrylic polymer fine particles, core shell acrylate Examples include organic fillers such as copolymer fine particles. These fillers may be used alone or in combination of two or more.

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, effects such as improvement in adhesiveness are further improved while suppressing deterioration of 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 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 N, for example. -Phenyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane, etc. are preferably used . 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 agents for liquid crystal display elements of this invention is 0.1 weight part, and a preferable upper limit is 20 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 0.5 weight part, and a more preferable upper limit is 10 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 preferable.

Titanium black is a substance having a higher transmittance in the vicinity of the ultraviolet region, particularly for light having a wavelength of 370 to 450 nm, compared to the average transmittance for light having 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. Accordingly, as the photo radical polymerization initiator, a photocatalyst for the sealing agent for liquid crystal display elements of the present invention can be used by using a photo initiator capable of initiating the reaction with light having a wavelength (370 to 450 nm) at which the transmittance of titanium black is high. Curability can be further increased. On the other hand, 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 titanium black preferably has an optical density (OD value) per μm of 3 or more, more preferably 4 or more. The higher the light-shielding property of the titanium black, the better. The OD value of the titanium black is not particularly limited, but is usually 5 or less.

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 sufficient light-shielding properties, and therefore 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 (all manufactured by Mitsubishi Materials Corporation), Tilak D (manufactured by Ako Kasei Co., Ltd.), and the like.

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 5 parts by weight or more, the obtained sealing agent for liquid crystal display elements is more excellent in light-shielding properties. When the content of the light-shielding agent is 80 parts by weight or less, the obtained sealing agent for liquid crystal display elements is excellent in adhesion to the substrate, strength after curing, and drawing properties. 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.

The sealing agent for liquid crystal display elements of the present invention further comprises a reactive diluent for adjusting the viscosity, a spacer such as polymer beads for adjusting the panel gap, 3-P-chlorophenyl-1,1- You may contain additives, such as hardening accelerators, such as a dimethyl urea and isocyanuric carboxylic acid, an antifoamer, a leveling agent, a polymerization inhibitor, and another coupling agent.

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 thereof include a method of mixing a radical polymerization initiator and an additive such as a silane coupling agent added as necessary.

As for the sealing compound for liquid crystal display elements of this invention, the preferable minimum of the glass transition temperature of hardened | cured material is 100 degreeC. When the glass transition temperature of the cured product is 100 ° C. or higher, the effect of suppressing display unevenness of the liquid crystal display element after storage in a high-temperature and high-humidity environment is excellent. The minimum with a more preferable glass transition temperature of the said hardened | cured material is 110 degreeC.
From the viewpoint of adhesiveness, the preferable upper limit of the glass transition temperature of the cured product is 130 ° C., and the more preferable upper limit is 120 ° C.
In the present specification, the “glass transition temperature” means a temperature at which a maximum due to micro-Brownian motion appears among the maximum of loss tangent (tan δ) obtained by dynamic viscoelasticity measurement. It can be measured by a conventionally known method using an apparatus or the like. The cured product for measuring the glass transition temperature can be obtained by heating at 120 ° C. for 1 hour when the sealing agent for liquid crystal display elements is cured by heating, and 100 mW when cured by light irradiation. / Cm ² of ultraviolet light for 30 seconds.

A vertical conduction material can be produced by blending conductive fine particles with the sealing agent for liquid crystal display elements 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 said electroconductive fine particles, what formed the conductive metal layer on the surface of a metal ball, resin microparticles | fine-particles etc. can be used, for example. 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 of the present invention is provided on one of two transparent substrates having electrodes such as an ITO thin film. A step of forming a frame-shaped seal pattern by screen printing, dispenser application, etc., a step of applying a liquid crystal microdrop on the entire surface of the frame of the seal pattern, and superimposing the other substrate under vacuum, and The method etc. which have the process of heating and hardening a sealing compound are mentioned.

ADVANTAGE OF THE INVENTION According to this invention, it is the liquid crystal display element seal | sticker which is excellent in light-shielding part sclerosis | hardenability, has the outstanding moisture resistance and adhesiveness also in a high temperature, high humidity environment, and can suppress generation | occurrence | production of the display nonuniformity of a liquid crystal display element. An agent 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 to 12, Comparative Examples 1 to 4)
In accordance with the blending ratios described in Tables 1 and 2, each material was stirred with a planetary stirrer (manufactured by Shinky Co., Ltd., “Awatori Netaro”) and then mixed uniformly with a ceramic three roll. Sealants for liquid crystal display elements of Examples 1 to 12 and Comparative Examples 1 to 4 were 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 and 2.

(1) Glass transition temperature Each of the sealing agents for liquid crystal display elements obtained in Examples 1 to 12 and Comparative Examples 1 to 3 was heated at 120 ° C. for 1 hour to completely cure the sealing agent, and a film having a thickness of 300 μm Was prepared as a test piece. About the sealing compound for liquid crystal display elements obtained by the comparative example 4, instead of heating at 120 degreeC for 1 hour, the test piece was obtained by irradiating 100 mW / cm < ² > ultraviolet-ray for 30 second using a metal halide lamp. The obtained test piece was measured for dynamic viscoelasticity at −80 to 200 ° C. and 10 Hz using a dynamic viscoelasticity measuring device (“DVA-200” manufactured by IT Measurement Control Co., Ltd.), and loss tangent (tan δ) ) Was determined as the glass transition temperature.

(2) Adhesiveness (initial adhesiveness and adhesiveness after high temperature and high humidity test)
Each of the sealing agents for liquid crystal display elements obtained in Examples and Comparative Examples was mixed with 1% by weight of a silica spacer (“SI-H055” manufactured by Sekisui Chemical Co., Ltd.), and two pieces of alkali glass test pieces with ITO film (30 × 40 mm) was finely dropped on one side, and the other glass test piece was bonded to this in a cross shape. With respect to the sealing agents for liquid crystal display elements obtained in Examples 1 to 12 and Comparative Examples 1 to 3, adhesion test pieces were obtained by heating at 120 ° C. for 1 hour. About the sealing compound for liquid crystal display elements obtained in Comparative Example 4, an adhesive test piece was obtained by irradiating with 100 mW / cm ² ultraviolet rays for 30 seconds using a metal halide lamp instead of heating at 120 ° C. for 1 hour. . A tensile test (5 mm / sec) was performed by placing chucks on the upper and lower sides of the obtained adhesion test piece.
Further, the adhesion test piece produced in the same manner was left in an environment of 121 ° C., 100% RH, 2 atm for 48 hours, and then subjected to a tensile test (5 mm / sec).
If the resulting value obtained by dividing measured values (kgf) in the seal coating cross sectional area (cm ²⁾ is "◎" the case was 290kgf / cm ² or more was 270 kgf / cm ² or more 290kgf / cm of less than ² The initial adhesiveness and the adhesiveness after the high-temperature and high-humidity test are indicated as “◯”, “△” when 250 kgf / cm ² or more and less than 270 kgf / cm ² , and “X” when 250 kgf / cm ^{2 or} less. evaluated.

(3) Light-shielding part curable A substrate (A) on which a half surface of Corning glass having a thickness of 0.7 mm was vapor-deposited and a substrate (B) in which the front surface was vapor-deposited with chromium were separately prepared. Next, 1 part by weight of spacer fine particles (manufactured by Sekisui Chemical Co., Ltd., “Micropearl SI-H050”, 5 μm) is dispersed in 100 parts by weight of the sealant for each liquid crystal display element obtained in Examples and Comparative Examples. The sealing agent was applied to the center part of the substrate A (the boundary between the chromium deposition part and the non-deposition part), and after the substrate B was bonded, the sealing agent was sufficiently crushed. The sealing agents for liquid crystal display elements obtained in Examples 1 to 12 and Comparative Examples 1 to 3 were then heated at 120 ° C. for 1 hour to cure the sealing agent. About the sealing agent for liquid crystal display elements obtained in Comparative Example 4, instead of heating at 120 ° C. for 1 hour, the sealing agent was applied by irradiating 100 mW / cm ² of ultraviolet rays from the substrate A side using a metal halide lamp for 30 seconds. Cured.
Thereafter, the substrates A and B are peeled off using a cutter, and the spectrum is measured by a microscopic IR method with respect to the sealing agent located at a position 50 μm away from the boundary between the chromium deposition part and the non-deposition part of the substrate A to the chromium deposition part side. The conversion rate of the (meth) acryloyl group in the sealant was determined by the following method. That is, 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, the conversion ratio of the (meth) acryloyl group is calculated according to the following formula: A light-shielding portion where the conversion rate of the (meth) acryloyl group was 95% or more, “◯”, 90% or more and less than 95% “△”, and less than 90% “×” The curability was evaluated.
Conversion rate of (meth) acryloyl group (%) = (1− (peak area of (meth) acryloyl group after curing of sealant / reference peak area after curing of sealant) / ((meth) acryloyl before curing of sealant) Group peak area / reference peak area before curing of sealant)) × 100

(4) Display performance of liquid crystal display element (immediate evaluation of color unevenness of liquid crystal display element driven immediately after fabrication and after storage in a high temperature and high humidity environment)
Each liquid crystal display element sealant obtained in Examples and Comparative Examples was filled in a dispensing syringe (“PSY-10E” manufactured by Musashi Engineering Co., Ltd.) and subjected to defoaming treatment. Next, using a dispenser (“SHOTMASTER 300” manufactured by Musashi Engineering Co., Ltd.), a sealing agent was applied so as to draw a rectangular frame on 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 with a liquid crystal dropping device, and the other transparent substrate is bonded under a reduced pressure of 5 Pa with a vacuum laminating device. Formed. About each liquid crystal display element sealing agent obtained in Examples 1 to 12 and Comparative Examples 1 to 3, the obtained cells were heated at 120 ° C. for 1 hour to cure the sealing agent, thereby producing liquid crystal display elements. did. About the sealing agent for liquid crystal display elements obtained in Comparative Example 4, instead of heating the obtained cell at 120 ° C. for 1 hour, it was sealed by irradiating 100 mW / cm ² ultraviolet rays for 30 seconds using a metal halide lamp. The agent was cured to produce a liquid crystal display element. About the obtained liquid crystal display element, after storing for 36 hours in the environment of temperature 80 degreeC humidity 90% RH immediately after preparation, the voltage drive of AC3.5V was carried out and it observed visually. “◎” when no display unevenness (color unevenness) is observed at the periphery of the liquid crystal display element, “○” when slightly uneven display appears at the periphery, and clear dark display unevenness at the periphery The display performance of the liquid crystal display element was evaluated with “△” when the image was present and “×” when the clear dark display unevenness spread not only to the periphery but also to the center.

Claims

A sealing agent for a liquid crystal display element containing a curable resin and a thermal radical polymerization initiator,
The said curable resin contains the compound which has 2 or more of acryloyl groups in 1 molecule, and the compound which has 2 or more of methacryloyl groups in 1 molecule, The sealing compound for liquid crystal display elements characterized by the above-mentioned.
The sealing agent for liquid crystal display elements according to claim 1, wherein the ratio of methacryloyl groups to the total amount of acryloyl groups and methacryloyl groups in the entire curable resin is 5 mol% or more.
3. The sealing agent for a liquid crystal display element according to claim 1, wherein the content of the compound having two or more methacryloyl groups in one molecule in 100 parts by weight of the entire curable resin is 1 to 75 parts by weight. .
4. The curable resin contains a partial (meth) acryl-modified epoxy resin having one or more epoxy groups and one (meth) acryloyl group in one molecule. A sealing agent for liquid crystal display elements.
The glass transition temperature of hardened | cured material is 100 degreeC or more, The sealing compound for liquid crystal display elements of Claim 1, 2, 3 or 4 characterized by the above-mentioned.
The light-shielding agent is contained, The sealing agent for liquid crystal display elements of Claim 1, 2, 3, 4 or 5 characterized by the above-mentioned.
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.