WO2017183583A1

WO2017183583A1 - Sealant for liquid crystal display element, method for manufacturing sealant for liquid crystal display element, vertical conduction material, and liquid crystal display element

Info

Publication number: WO2017183583A1
Application number: PCT/JP2017/015318
Authority: WO
Inventors: 洋小林
Original assignee: 積水化学工業株式会社
Priority date: 2016-04-20
Filing date: 2017-04-14
Publication date: 2017-10-26
Also published as: JP7053262B2; CN107924093A; JPWO2017183583A1; KR20180129753A; TW201809055A

Abstract

The purpose of the present invention is to provide a sealant for a liquid crystal display element, the sealant having superior adhesion properties and light-blocking-section curing properties and serving to reduce environmental load. Another purpose of the present invention is to provide a method for manufacturing the sealant for a liquid crystal display element, as well as a vertical conduction material and a liquid crystal display element made by using the sealant for a liquid crystal display element. The present invention provides a sealant for a liquid crystal display element, the sealant containing a curable resin and a polymerization initiator and/or a heat curing agent, wherein the curable resin contains a bisphenol-A epoxy resin and/or a (meth)acrylic modified bisphenol-A epoxy resin, and the bisphenol A content is not more than 500 ppm.

Description

SEALING AGENT FOR LIQUID CRYSTAL DISPLAY ELEMENT, PROCESS FOR PRODUCING SEALING AGENT FOR LIQUID CRYSTAL DISPLAY ELEMENT, VERTICAL CONDUCTIVE MATERIAL, AND LIQUID CRYSTAL DISPLAY ELEMENT

The present invention relates to a sealant for a liquid crystal display element that is excellent in adhesiveness and light-shielding part curability and that can reduce the burden on the environment. Moreover, this invention relates to the manufacturing method of this sealing compound for liquid crystal display elements, and 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 for manufacturing a liquid crystal display element, a curable resin, a photopolymerization initiator, and a heat 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 curing 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 to perform main curing, and a liquid crystal display element is manufactured. A liquid crystal display element can be manufactured with extremely high efficiency by bonding the substrates under a reduced pressure, and this dropping 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.

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

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

The present invention is a liquid crystal display element sealing agent comprising a curable resin and a polymerization initiator and / or a thermosetting agent, wherein the curable resin is a bisphenol A type epoxy resin and / or (meth) acrylic. It is a sealing agent for liquid crystal display elements that contains a modified bisphenol A type epoxy resin and the content of bisphenol A is 50 ppm or less.
The present invention is described in detail below.

The present inventors have formulated a chemically and physically excellent bisphenol A type epoxy resin and / or (meth) acryl-modified bisphenol A type epoxy resin as the curable resin contained in the liquid crystal display element sealant. investigated. However, when such a curable resin is used, there is a problem that sufficient light-shielding part curability may not be obtained. The inventors of the present invention have the reason that the light-shielding part curability is deteriorated because bisphenol A slightly present in the bisphenol A type epoxy resin and / or the (meth) acryl-modified bisphenol A type epoxy resin inhibits the polymerization reaction. I thought that there was to be. Accordingly, the present inventors have found that by making the content of bisphenol A not more than a specific value, it is possible to obtain a sealing agent for a liquid crystal display element that is excellent in adhesiveness and light-shielding part curability. It came to complete. Moreover, since the sealing agent for liquid crystal display elements of this invention has reduced content of bisphenol A, the environmental load by this bisphenol A can be reduced.

The sealing agent for liquid crystal display elements of this invention contains curable resin.
The curable resin contains a bisphenol A type epoxy resin and / or a (meth) acryl-modified bisphenol A type epoxy resin. By containing the bisphenol A type epoxy resin and / or the (meth) acryl-modified bisphenol A type epoxy resin, the sealing agent for liquid crystal display elements of the present invention has excellent adhesiveness.
In the present specification, the “(meth) acryl” means acryl or methacryl. The (meth) acryl-modified bisphenol A type epoxy resin may be a completely (meth) acryl-modified bisphenol A type epoxy resin obtained by (meth) acryl-modifying all the epoxy groups of the bisphenol A type epoxy resin, A partial (meth) acryl-modified bisphenol A type epoxy resin in which a part of epoxy groups is (meth) acryl-modified may be used.

If a large amount of bisphenol A is present in the bisphenol A type epoxy resin and / or the (meth) acryl-modified bisphenol A type epoxy resin, the light-shielding part curability and environment of the resulting liquid crystal display element sealing agent are adversely affected. give.
The liquid crystal display element sealant of the present invention has a bisphenol A content of 50 ppm or less. By using the bisphenol A type epoxy resin and / or the (meth) acryl-modified bisphenol A type epoxy resin as the curable resin, the content of the bisphenol A is set to 50 ppm or less, whereby the liquid crystal display element seal of the present invention is used. The agent is excellent in adhesiveness and light-shielding part curability, and can reduce the burden on the environment.
The content of bisphenol A can be quantitatively measured using liquid chromatography by extracting bisphenol A from a sealing agent using an arbitrary solution such as a dimethyl sulfoxide solution.

As a method of setting the content of the bisphenol A to 50 ppm or less, for example, the bisphenol A type epoxy resin and / or the (meth) acryl-modified bisphenol A type epoxy resin can be removed by washing with pure water. Examples of the purification method include a method of purification by physical adsorption removal of bisphenol A using an adsorbent.
A method for producing a sealing agent for a liquid crystal display element according to the present invention, wherein a bisphenol A type epoxy resin and / or a (meth) acryl-modified bisphenol A type epoxy resin is purified by washing and removing bisphenol A with pure water. A method for producing a sealing agent for a liquid crystal display device, comprising: a step and a step of mixing a purified bisphenol A type epoxy resin and / or a (meth) acryl-modified bisphenol A type epoxy resin with at least a polymerization initiator and / or a thermosetting agent. And a step of purifying bisphenol A type epoxy resin and / or (meth) acryl-modified bisphenol A type epoxy resin by physical adsorption removal of bisphenol A using an adsorbent, a purified bisphenol A type epoxy resin and / or Or (meth) acryl-modified bisphenol A type epoxy Method of manufacturing a liquid crystal display device for sealing agent and a step of mixing with a resin at least a polymerization initiator and / or thermal curing agent is also one of the present invention, respectively.

When purifying the bisphenol A type epoxy resin and / or the (meth) acryl-modified bisphenol A type epoxy resin by washing and removing bisphenol A with pure water, the bisphenol A type epoxy resin and In addition, the above (meth) acryl-modified bisphenol A type epoxy resin and pure water are added, and the mixture can be purified by repeatedly performing a washing operation for separating pure water after stirring while heating.
The removal by washing with water is preferably performed using hot water of 40 ° C. to 50 ° C.

When the bisphenol A type epoxy resin and / or the (meth) acryl-modified bisphenol A type epoxy resin is purified by physical adsorption removal of bisphenol A using an adsorbent, examples of the adsorbent used include charcoal, Carbon-based porous materials such as coal, activated carbon and carbon black, inorganic porous materials such as silica gel, alumina and magnesia, zirconia crosslinked material, alumina crosslinked material, chromium oxide crosslinked material, titanium oxide crosslinked material, iron oxide crosslinked material And clay-based porous bodies, porous glasses, zeolites, styrene-divinylbenzene copolymers, polyacrylic ester-based crosslinked bodies, and ion exchange resins obtained by chemically modifying these.

The curable resin may contain other curable resins in addition to the bisphenol A type epoxy resin and / or the (meth) acryl-modified bisphenol A type epoxy resin.
Examples of the other curable resins include other (meth) acryl compounds other than the complete (meth) acryl-modified bisphenol A epoxy resin, the bisphenol A epoxy resin, and the partial (meth) acryl-modified bisphenol A epoxy. Examples include other epoxy compounds other than resins. Among them, the curable resin contains the complete (meth) acryl-modified bisphenol A type epoxy resin and / or the other (meth) acrylic compound (these are also simply referred to as “(meth) acrylic compounds”). It is preferable to do.
Examples of the other (meth) acrylic compounds include, for example, (meth) acrylic acid ester compounds obtained by reacting (meth) acrylic acid with a compound having a hydroxyl group, (meth) acrylic acid and bisphenol A type epoxy resin Other complete (meth) acryl-modified epoxy resins obtained by reacting with an epoxy compound, urethane (meth) acrylate obtained by reacting an isocyanate compound with a (meth) acrylic acid derivative having a hydroxyl group, etc. .
In the present specification, the “(meth) acrylate” means acrylate or methacrylate.

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, glycidyl (meth) acrylate, Examples include 2- (meth) acryloyloxyethyl phosphate.

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, 2-n-butyl-2-ethyl-1,3-propanediol di (meth) ) Acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) ) Acrylate, poly Ethylene 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, 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 (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, pentaerythritol tri (meth) acrylate, ethylene oxide-added isocyanuric acid tri (meth) acrylate, propylene oxide-added glycerin tri (meth) acrylate, tris (meth) acryloyloxyethyl Phosphate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaeryth Penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin tri (meth) acrylate.

The other complete (meth) acryl-modified epoxy resin can be obtained, for example, by reacting an epoxy compound other than bisphenol A type epoxy resin with (meth) acrylic acid in the presence of a basic catalyst according to a conventional method. And the like.

Examples of the epoxy compound used as a raw material for synthesizing the other complete (meth) acryl-modified epoxy resin include, for example, bisphenol F type epoxy resin, bisphenol S 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 type epoxy resin, orthocresol novolac type epoxy resin, dicyclopentadiene novolak type epoxy resin, biphenyl novolac type epoxy resin, naphthalene phenol novolak Type epoxy resin, glycidylamine type epoxy resin, alkyl polyol type epoxy resin, rubber-modified epoxy resin, glycidyl ester compound Etc. The.

As what is marketed among the said bisphenol F type epoxy resins, Epicoat 806, Epicoat 4004 (all are Mitsubishi Chemical Corporation 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 resorcinol type epoxy resins include EX-201 (manufactured by Nagase ChemteX Corporation).
Examples of commercially available biphenyl type epoxy resins include Epicoat 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 epoxy resins include Epicoat 630 (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).
Other commercially available epoxy resins 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.), Epicoat 1031 and Epicoat 1032. (All manufactured by Mitsubishi Chemical), EXA-7120 (manufactured by DIC), TEPIC (manufactured by Nissan Chemical) and the like.

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 the raw material for the urethane (meth) acrylate include isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, and diphenylmethane-4,4. '-Diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris (isocyanate) Phenyl) thiophosphate, tetramethylxylylene diisocyanate, 1,6,11-undecantrie Cyanate, and the like.

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. Mono (meth) acrylates of dihydric alcohols such as diols and polyethylene glycols, mono (meth) acrylates or di (meth) acrylates of trivalent alcohols such as trimethylolethane, trimethylolpropane, glycerin, and others mentioned above Complete (meth) acryl-modified epoxy resin and the like.

Examples of commercially available urethane (meth) acrylates include M-1100, M-1200, M-1210, M-1600 (all manufactured by Toagosei Co., Ltd.), 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 (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 upper limit with the preferable ratio of the epoxy group with respect to the total amount of the epoxy group and (meth) acryloyl group in the said whole curable resin is 50 mol%. When the ratio of the epoxy group is 50 mol% or less, the resulting liquid crystal display element sealant is less soluble in the liquid crystal and the liquid crystal contamination is lower. It will be excellent. A more preferable upper limit of the ratio of the epoxy group is 20 mol%.

Examples of the other epoxy compounds include, for example, the epoxy compounds mentioned as raw materials for synthesizing the other complete (meth) acryl-modified epoxy resins, and portions other than the partial (meth) acryl-modified bisphenol A type epoxy resins ( And a (meth) acryl-modified epoxy resin.

When the sealing agent for liquid crystal display elements of the present invention contains the other curable resin, the bisphenol A type epoxy resin and / or the (meth) acryl-modified bisphenol A type epoxy in 100 parts by weight of the curable resin as a whole. The preferable lower limit of the resin content is 10 parts by weight, and the preferable upper limit is 100 parts by weight. When the content of the bisphenol A-type epoxy resin and / or the (meth) acryl-modified bisphenol A-type epoxy resin is within this range, the obtained sealing agent for liquid crystal display elements has adhesiveness, applicability, and low liquid crystal contamination. Etc. The minimum with more preferable content of the said bisphenol A type epoxy resin and / or the said (meth) acryl modified bisphenol A type epoxy resin is 20 weight part, and a more preferable upper limit is 90 weight part.

The sealing agent for liquid crystal display elements of this invention contains a polymerization initiator and / or a thermosetting agent.
As the polymerization initiator, a radical polymerization initiator is preferably used from the viewpoint of curing speed and the like. When the above radical polymerization initiator is used, the inhibition of curing by bisphenol A is particularly likely to occur. However, the sealing agent for liquid crystal display elements of the present invention has such an extremely small content of bisphenol A that it inhibits such curing inhibition. It suppresses and becomes excellent in light-shielding part curability.
Examples of the radical polymerization initiator include a photo radical polymerization initiator that generates radicals by light irradiation, a thermal radical polymerization initiator that generates radicals by heating, and the like.

Examples of the photo radical polymerization initiator include benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, thioxanthone compounds, 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 ), NCI-930 (manufactured by ADEKA), SPEEDCURE EMK (manufactured by Nippon Sebel Hegner), benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.) and the like.

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 compound means a compound having an azo group and generating a radical capable of curing a (meth) acryloyl group 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 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 easily mixed with a curable resin while suppressing liquid crystal contamination. 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 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 polymerization initiator is preferably 0.01 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 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 polymerization initiator is 0.1 weight part, and a more preferable upper limit is 5 weight part.

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, for example, SDH, ADH (all manufactured by Otsuka Chemical Co., Ltd.), Amicure VDH, Amicure VDH-J, Amicure UDH, Amicure UDH-J (all Ajinomoto Fine Techno Co., Ltd.) Manufactured) and the like.

The content of the thermosetting agent is preferably 1 part by weight with respect to 100 parts by weight of the curable resin, and 50 parts by weight with respect to the preferable upper limit. When the content of the thermosetting agent is within this range, the thermosetting property can be further improved without deteriorating the applicability of the obtained sealing agent for liquid crystal display elements. When content of the said thermosetting agent exceeds 50 weight part, the viscosity of the sealing compound for liquid crystal display elements obtained will become high, and applicability | paintability may worsen. 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 viscosity, improving adhesiveness due to stress dispersion effect, improving linear expansion coefficient, improving moisture permeability of cured products, and the like. preferable.

Examples of the 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, titanium oxide, Organic fillers such as calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum nitride, silicon nitride, barium sulfate, and calcium silicate, and organic materials such as polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, and acrylic polymer fine particles A filler is mentioned.

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

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

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

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

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. The light shielding agent contained in the liquid crystal display element sealant of the present invention is preferably a highly insulating material, and titanium black is also preferred as the highly insulating light shielding agent.

The above-mentioned titanium black exhibits a sufficient effect even if it is not surface-treated, but the surface is treated with an organic component such as a coupling agent, silicon oxide, titanium oxide, germanium oxide, aluminum oxide, oxidized Surface-treated titanium black such as those coated with an inorganic component such as zirconium or magnesium oxide can also be used. Especially, what is processed with the organic component is preferable at the point which can improve insulation more.
In addition, the liquid crystal display element produced using the sealing agent for liquid crystal display elements of the present invention containing the above-described titanium black as a light-shielding agent has 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, 14M-C (all manufactured by Mitsubishi Materials Corporation), Tilak D (manufactured by Ako Kasei Co., Ltd.), and the like. Can be mentioned.

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

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

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

The sealing agent for liquid crystal display elements of the present invention is further added as necessary, stress relieving agent, reactive diluent, thixotropic agent, spacer, curing accelerator, antifoaming agent, leveling agent, polymerization inhibitor, etc. An agent or the like may be contained.

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, a three roll, a curable resin, and a polymerization Examples thereof include a method of mixing an initiator and / or a thermosetting agent and an additive such as a silane coupling agent added as necessary.

The sealing agent for liquid crystal display elements of the present invention has a preferable lower limit of 50,000 mPa · s and a preferable upper limit of 700,000 mPa · s measured using an E-type viscometer at 25 ° C. and 1 rpm. When the viscosity is within this range, the obtained sealing agent for liquid crystal display elements has excellent coating properties. A more preferable lower limit of the viscosity is 100,000 mPa · s, and a more preferable upper limit is 500,000 mPa · s.
As the E-type viscometer, for example, 5XHBDV-III + CP (manufactured by Brookfield, rotor No. CP-51) can be used.

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

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

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

As a method for producing the liquid crystal display element of the present invention, a liquid crystal dropping method is preferably used. Specifically, for example, the liquid crystal display element sealant of the present invention is applied to one of two substrates such as a glass substrate with electrodes such as an ITO thin film or a polyethylene terephthalate substrate by screen printing, dispenser application, or the like. A step of forming a frame-shaped seal pattern, in which the liquid crystal display element sealant of the present invention is in an uncured state, droplets of liquid crystal are dropped into the frame of the substrate seal pattern, and another substrate is stacked under vacuum. A step of aligning, a step of irradiating the seal pattern portion of the sealant for the liquid crystal display element of the present invention with light such as ultraviolet rays, and temporarily curing the sealant, and heating and temporarily curing the temporarily cured sealant. Examples thereof include a method having a step.

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal display elements which is excellent in adhesiveness and light-shielding part sclerosis | hardenability, and can reduce the load to an environment can be provided. Moreover, according to this invention, the manufacturing method of this sealing compound for liquid crystal display elements, and 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.

(Preparation of bisphenol A type epoxy resin solution)
1000 parts by weight of a 10% aqueous sodium hydroxide solution, 230 parts by weight of bisphenol A and 180 parts by weight of epichlorohydrin were added to the flask, and the mixture was stirred at 80 ° C. for 3 hours in a nitrogen atmosphere. Next, 600 parts by weight of methyl isobutyl ketone was added to dissolve the reaction product, and then allowed to stand to separate and remove the aqueous layer. Thereafter, 300 parts by weight of 0.1 mol / L hydrochloric acid aqueous solution was added and stirred, and then the aqueous layer was separated and removed to obtain a bisphenol A type epoxy resin solution.

(Preparation of bisphenol A type epoxy resin A (refined product))
A washing operation for separating and removing pure water after adding 500 parts by weight of pure water to the bisphenol A type epoxy resin solution obtained in “(Preparation of bisphenol A type epoxy resin solution)” and heating and stirring at 50 ° C. for 30 minutes. Went. Further, this water washing operation was repeated four times, and then the solvent was removed by distillation under reduced pressure to obtain bisphenol A type epoxy resin A (refined product). The pure water used for the washing operation is warm water of 40 ° C. to 50 ° C.

(Preparation of bisphenol A type epoxy resin B (refined product))
To the bisphenol A type epoxy resin solution obtained in “(Preparation of bisphenol A type epoxy resin solution)”, 10 parts by weight of Kyoward 2000 (Kyowa Chemical Industry Co., Ltd., aluminum oxide / magnesium oxide solid solution) was added as an adsorbent. After heating and stirring at 50 ° C. for 30 minutes and separating Kyward 2000 by filtration, the solvent was removed by distillation under reduced pressure to obtain bisphenol A type epoxy resin B (purified product).

(Preparation of bisphenol A type epoxy resin C (unfinished product))
Methyl isobutyl ketone was removed from the bisphenol A type epoxy resin solution obtained in “(Preparation of bisphenol A type epoxy resin solution)” by vacuum distillation to obtain bisphenol A type epoxy resin C (unrefined product).

(Preparation of bisphenol A type epoxy resin D (refined product))
A washing operation for separating and removing pure water after adding 500 parts by weight of pure water to the bisphenol A type epoxy resin solution obtained in “(Preparation of bisphenol A type epoxy resin solution)” and heating and stirring at 50 ° C. for 30 minutes. Went. Furthermore, after repeating this water washing operation twice, the solvent was removed by distillation under reduced pressure to obtain bisphenol A type epoxy resin A (refined product). The pure water used for the washing operation is warm water of 40 ° C. to 50 ° C.

(Preparation of bisphenol A type epoxy resin E (refined product))
A washing operation for separating and removing pure water after adding 500 parts by weight of pure water to the bisphenol A type epoxy resin solution obtained in “(Preparation of bisphenol A type epoxy resin solution)” and heating and stirring at 50 ° C. for 30 minutes. Went. Subsequently, the solvent was removed by distillation under reduced pressure to obtain bisphenol A type epoxy resin A (purified product). The pure water used for the washing operation is warm water of 40 ° C. to 50 ° C.

(Production of acrylic modified bisphenol A type epoxy resin (refined product))
150 parts by weight of acrylic acid and 5 parts by weight of triethylbenzylammonium chloride are added to the bisphenol A type epoxy resin solution obtained in “(Preparation of bisphenol A type epoxy resin solution)” and stirred at 80 ° C. for 3 hours in a nitrogen atmosphere. went. Next, 800 parts by weight of pure water and 800 parts by weight of diethyl ether were added and stirred, and then a water washing operation for separating and removing the aqueous layer was performed. Further, this washing operation was repeated 4 times, and then the solvent was removed by distillation under reduced pressure to obtain an acrylic-modified bisphenol A type epoxy resin (purified product). The pure water used for the washing operation is warm water of 40 ° C. to 50 ° C.

(Examples 1 to 5 and Comparative Examples 1 and 2)
According to the mixing ratio described in Table 1, each material was mixed using a planetary stirrer (manufactured by Shinky Co., Ltd., “Awatori Nertaro”), and then further mixed using three rolls. To 5 and Comparative Examples 1 and 2 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 Table 1.

(Bisphenol A content)
Each liquid crystal display element sealing agent obtained in Examples and Comparative Examples was prepared to be a 0.1 wt / vol% dimethyl sulfoxide solution and shaken for 2 hours. Subsequently, the obtained solution was diluted 10-fold with methanol, filtered through a 0.2 μm filter, and the content of bisphenol A was measured by liquid chromatography using an external standard method.

(Adhesiveness)
One part by weight of spacer particles (Sekisui Chemical Co., Ltd., “Micropearl SP-2050”) having an average particle diameter of 5 μm is used for 100 parts by weight of each sealing agent for liquid crystal display elements obtained in Examples and Comparative Examples. Disperse uniformly with a stirrer, take a trace amount in the center of Corning glass 1737 (20 mm x 50 mm x thickness 0.7 mm), and stack the same type of glass on top to spread the sealant for liquid crystal display elements After irradiating with 100 mW / cm ² ultraviolet rays for 30 seconds using a metal halide lamp, the sealant was cured by heating at 120 ° C. for 1 hour to obtain an adhesion test piece.
About the obtained adhesion test piece, the adhesive strength was measured using the tension gauge. The resulting value obtained by dividing measured values (kgf) in the seal coating cross sectional area (cm ²⁾ is a case was 35 kgf / cm ² or more "◎" was 30 kgf / cm ² or more 35 kgf / cm less than ² where "○", the case was 25 kgf / cm ² or more 30 kgf / cm less than ² "△", and evaluated the adhesiveness of the case was less than 25 kgf / cm ² as "×".

(Light-shielding part curability)
First, the board | substrate A which vapor-deposited one side half of the 0.7 mm thick Corning glass and the board | substrate B which vapor-deposited the whole single side | surface were prepared. Next, 1 part by weight of spacer fine 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 element obtained in Examples and Comparative Examples. Is uniformly dispersed by a planetary stirrer, and the obtained sealant is applied to the central part of the substrate A (boundary between the chromium vapor deposition part and the non-deposition part), and after the substrate B is bonded, the sealant is sufficiently applied. After crushing, 100 mW / cm ² ultraviolet rays were irradiated for 5 seconds from the substrate A 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, 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: The conversion rate was 90% or more, “◎”, 70% or more, but less than 90%, “◯”, 50% or more, less than 70%, “△”, less than 50%. The curability of the light-shielding part was evaluated with “×” as the sample.
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 1))
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. After uniformly dispersing with a stirrer, the resulting sealant is filled into a dispensing syringe (Musashi Engineering, PSY-10E), defoamed, and dispenser (Musashi Engineering, The sealant was applied in a frame shape to one of the two transparent electrode substrates with an ITO thin film by using SHOTMASTER 300 "). 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.
Regarding the obtained liquid crystal display element, the display unevenness generated in the liquid crystal (especially the corner portion) around the seal portion was visually observed, and when the display unevenness was not confirmed, “◎”, slight display unevenness was confirmed. The display performance of the liquid crystal display element (low liquid crystal contamination 1) was evaluated with “◯” as the case, “△” when the display unevenness was clearly confirmed, and “X” when the severe display unevenness was confirmed.
Note that the liquid crystal display elements evaluated as “◎” and “、” are at a level that causes no problem in practical use.

(Display performance of liquid crystal display elements (low liquid crystal contamination 2))
A liquid crystal display device manufactured by the same method as “(Display performance of liquid crystal display device (low liquid crystal contamination 1))” was allowed to stand for 180 days at 40 ° C. and 50% RH, and then the liquid crystal around the seal portion. The display unevenness that occurs in the corners (especially in the corners) is visually observed. If no display unevenness is observed, “◎”, if slight display unevenness is confirmed, “○”, clearly display unevenness is confirmed. The display performance of the liquid crystal display element (low liquid crystal contamination 2) was evaluated with “△” when the case was severe and “x” when the severe display unevenness was confirmed.
If the display performance deteriorated compared to the initial stage (display performance of the liquid crystal display element (low liquid crystal contamination 1)), it is presumed that a slight uncured component in the sealant gradually eluted into the liquid crystal.
Note that the liquid crystal display elements evaluated as “◎” and “、” are at a level that causes no problem in practical use.

Claims

A sealing agent for a liquid crystal display element comprising a curable resin, a polymerization initiator and / or a thermosetting agent,
The curable resin contains a bisphenol A type epoxy resin and / or a (meth) acryl-modified bisphenol A type epoxy resin,
A sealing agent for liquid crystal display elements, wherein the content of bisphenol A is 50 ppm or less.
The sealing agent for liquid crystal display elements according to claim 1, wherein the curable resin contains a (meth) acrylic compound.
A method for producing a sealing agent for a liquid crystal display element according to claim 1 or 2,
A step of purifying a bisphenol A type epoxy resin and / or a (meth) acryl-modified bisphenol A type epoxy resin by washing and removing bisphenol A with pure water;
And a step of mixing a purified bisphenol A type epoxy resin and / or a (meth) acryl-modified bisphenol A type epoxy resin with at least a polymerization initiator and / or a thermosetting agent. Production method.
A method for producing a sealing agent for a liquid crystal display element according to claim 1 or 2,
A step of purifying bisphenol A type epoxy resin and / or (meth) acryl-modified bisphenol A type epoxy resin by physical adsorption removal of bisphenol A using an adsorbent;
And a step of mixing a purified bisphenol A type epoxy resin and / or a (meth) acryl-modified bisphenol A type epoxy resin with at least a polymerization initiator and / or a thermosetting agent. Production method.
A vertical conduction material comprising the sealing agent for a liquid crystal display element according to claim 1 or 2 and conductive fine particles.
A liquid crystal display element comprising the sealant for a liquid crystal display element according to claim 1 or 2 or the vertical conduction material according to claim 5.