WO2017221936A1

WO2017221936A1 - Sealant for liquid crystal display elements, vertical conduction material, and liquid crystal display element

Info

Publication number: WO2017221936A1
Application number: PCT/JP2017/022717
Authority: WO
Inventors: 祐美子寺口
Original assignee: 積水化学工業株式会社
Priority date: 2016-06-21
Filing date: 2017-06-20
Publication date: 2017-12-28
Also published as: KR20220066190A; JP6978314B2; KR102531223B1; CN108292067B; CN108292067A; TW201829511A; JPWO2017221936A1; TWI797083B; KR20190016931A

Abstract

The purpose of the present invention is to provide a sealant for liquid crystal display elements, which is capable of achieving adhesiveness and prevention of permeation of moisture in a cured product. The purpose of the present invention is also to provide a vertical conduction material and liquid crystal display element which are obtained using the sealant for liquid crystal display elements. The sealant for liquid crystal display elements according to the present invention contains a curable resin, and a polymerization initiator and/or a thermosetting agent, wherein the curable resin contains a compound represented by formula (1), and the content of the compound represented by formula (1) is 1-90 parts by weight with respect to 100 parts by weight of the curable resin. In formula (1), R¹ represents a hydrogen atom or a methyl group, R² represents a group represented by formula (2-1), (2-2), or (2-3), Ar represents an optionally substituted arylene group, X represents a ring-opened structure of a cyclic lactone, n represents a value of 0-0.5 (average value), and Ep represents an epoxy compound-derived structure. In formulae (2-1)-(2-3), * represents a bonding position. In formula (2-2), "a" represents an integer of 1-8. In formula (2-3), b represents an integer of 1-8, c represents an integer of 1-3, and d represents an integer of 1-8.

Description

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

The present invention relates to a sealant for a liquid crystal display element that can achieve both adhesiveness and moisture permeation preventive property of a cured product. Moreover, this invention relates to the vertical conduction material and liquid crystal display element which use this sealing compound for liquid crystal display elements.

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

By the way, in the present age when mobile devices with various liquid crystal panels such as mobile phones and portable game machines are widespread, downsizing of devices is the most demanded issue. As a technique for miniaturization, there is a narrow frame of the liquid crystal display unit, and for example, the position of the seal portion is arranged under the black matrix (hereinafter also referred to as a narrow frame design).
With such a narrow frame design, in the liquid crystal display element, the distance from the pixel region to the sealing agent is close, and display unevenness due to contamination of the liquid crystal by the sealing agent is likely to occur.

In addition, with the spread of tablet devices and mobile devices, liquid crystal display elements are increasingly required to have moisture resistance reliability when driving in high-temperature and high-humidity environments, and the sealant prevents water from entering from the outside. There is a further demand for performance. In order to improve the moisture resistance reliability of the liquid crystal display element, in order to prevent water from entering from the interface between the sealing agent and the substrate, the adhesion of the sealing agent to the substrate, etc. is improved, and the moisture permeability of the sealing agent is prevented. It is necessary to improve the performance. As a method for improving the moisture permeation preventive property of the sealing agent, for example, a method of blending a filler such as talc can be considered. However, even when a filler such as talc is added in this way, when a strict moisture resistance reliability test is performed, there is a problem that display unevenness occurs in the liquid crystal display element.

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

The present invention relates to a sealant for a liquid crystal display element that can achieve both adhesiveness and moisture permeation preventive property of a cured product. Another object of the present invention is to provide a vertical conduction material and a liquid crystal display element using the sealing agent for a liquid crystal display element.

The present invention is a liquid crystal display element sealing agent containing a curable resin and a polymerization initiator and / or a thermosetting agent, wherein the curable resin contains a compound represented by the following formula (1). A liquid crystal display element sealing agent, wherein the content of the compound represented by the formula (1) in 100 parts by weight of the curable resin is 1 to 90 parts by weight.

In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a group represented by the following formula (2-1), (2-2), or (2-3) , Ar represents an optionally substituted arylene group, X represents a ring-opening structure of a cyclic lactone, n is 0 to 0.5 (average value), and Ep is a structure derived from an epoxy compound Represents.

In formulas (2-1) to (2-3), * represents a bonding position, in formula (2-2), a is an integer of 1 to 8, and in formula (2-3), b Is an integer from 1 to 8, c is an integer from 1 to 3, and d is an integer from 1 to 8.
The present invention is described in detail below.

The present inventor surprisingly uses a specific amount of a compound having a specific structure as the curable resin, thereby making it possible to achieve both adhesiveness and moisture permeation preventive property of the cured product. Has been found, and the present invention has been completed.

The sealing agent for liquid crystal display elements of this invention contains curable resin.
The said curable resin contains the compound represented by the said Formula (1). By containing the compound represented by the above formula (1), the sealing agent for liquid crystal display elements of the present invention can achieve both adhesiveness and moisture permeation preventive property of the cured product.

In the above formula (1), R ¹ represents a hydrogen atom or a methyl group. Among them, from the viewpoint of moisture proof property of the cured product of the liquid crystal display element sealing agent obtained, the R ¹ is preferably a methyl group.

In the above formula (1), R ² represents a group represented by the above formula (2-1), (2-2), or (2-3). Among these, from the viewpoint of the adhesiveness of the obtained sealing agent for liquid crystal display elements and the flexibility of the cured product, R ² is preferably a group represented by the above formula (2-2). In 2-2), a group in which a is 2 (ethylene group) is more preferable.

In said formula (1), Ar represents the arylene group which may be substituted.
Examples of the arylene group include 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, 1,4-naphthylene group, 1,5-naphthylene group, 1,8-naphthylene group, Examples include 2,6-naphthylene group and 2,7-naphthylene group. Of these, a 1,2-phenylene group and a 1,8-naphthylene group are preferable, and a 1,2-phenylene group is more preferable.

In the above formula (1), X represents a ring-opening structure of a cyclic lactone.
Examples of the cyclic lactone include γ-undecalactone, ε-caprolactone, γ-decalactone, σ-dodecalactone, γ-nonalactone, γ-nonanolactone, γ-valerolactone, σ-valerolactone, β-butyrolactone, γ -Butyrolactone, β-propiolactone, σ-hexanolactone, 7-butyl-2-oxepanone and the like. Among them, those in which the straight chain portion of the main skeleton has 5 to 7 carbon atoms when ring-opened are preferable.

In formula (1), Ep represents a structure derived from an epoxy compound.
Examples of the epoxy compound from which Ep is derived include, for example, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol E type epoxy compounds, bisphenol S type epoxy compounds, resorcinol type epoxy compounds, dicyclopentadiene type epoxy compounds, and naphthalene. Type epoxy compounds, rubber-modified epoxy compounds, glycidyl ester compounds, and the like.
Among them, the compound represented by the above formula (1) has a structure where n is 0 and Ep is derived from a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, or a bisphenol E type epoxy compound. Is preferred.

Examples of the method for producing the compound represented by the above formula (1) include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl acrylate and aromatic carboxylic acid anhydrides such as phthalic anhydride and naphthalic anhydride. And a step of reacting by heating and stirring in the presence of a polymerization inhibitor such as hydroquinone and p-methoxyphenol, and a step of adding an epoxy resin to the obtained reaction product and reacting by heating and stirring. And the like. The hydroxyalkyl (meth) acrylate may be partially reacted with a cyclic lactone such as ε-caprolactone before reacting with the aromatic carboxylic acid anhydride.
In the present specification, the “(meth) acrylate” means acrylate or methacrylate.

The lower limit of the content of the compound represented by the formula (1) in 100 parts by weight of the curable resin is 1 part by weight, and the upper limit is 90 parts by weight. When the content of the compound represented by the formula (1) is 1 part by weight or more, the obtained sealing agent for liquid crystal display elements is excellent in adhesiveness. When the content of the compound represented by the above formula (1) is 90 parts by weight or less, the obtained sealing agent for liquid crystal display elements has excellent workability in each process during liquid crystal display element production, such as applicability. It becomes. The preferred lower limit of the content of the compound represented by the formula (1) is 5 parts by weight, the preferred upper limit is 85 parts by weight, the more preferred lower limit is 10 parts by weight, the more preferred upper limit is 80 parts by weight, and the still more preferred lower limit is 12 parts by weight. Parts, and a more preferred upper limit is 75 parts by weight.

It is preferable that the said curable resin contains an epoxy compound from a viewpoint of improving adhesiveness more.
Examples of the epoxy compound include bisphenol A 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, and naphthalene type epoxy. Resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, dicyclopentadiene novolac type epoxy resin, biphenyl novolac type epoxy resin, naphthalenephenol novolac type epoxy resin, glycidylamine type epoxy resin, alkyl polyol type epoxy resin, rubber modified Type epoxy resin, glycidyl ester compound and the like.

Examples of commercially available bisphenol A type epoxy resins include jER828 and jER1001 (both manufactured by Mitsubishi Chemical Corporation).
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 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).
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.), jER1031, jER1032 (all Also, Mitsubishi Chemical Corporation), EXA-7120 (DIC Corporation), TEPIC (Nissan Chemical Corporation) and the like.

Moreover, the said curable resin may contain a partial (meth) acryl modified epoxy resin as said epoxy compound.
In the present specification, the partial (meth) acryl-modified epoxy resin means a compound having one or more epoxy groups and one or more (meth) acryloyl groups in one molecule. It can be obtained by reacting an epoxy group of a part of an epoxy compound having two or more epoxy groups therein with (meth) acrylic acid.

The preferable lower limit of the content of the epoxy compound in 100 parts by weight of the curable resin is 1 part by weight, and the preferable upper limit is 80 parts by weight. When the content of the epoxy compound is within this range, the obtained sealing agent for a liquid crystal display element is more excellent in adhesiveness while suppressing the occurrence of liquid crystal contamination. The more preferable lower limit of the content of the epoxy compound is 5 parts by weight, and the more preferable upper limit is 70 parts by weight.

The said curable resin may contain another curable resin in the range which does not inhibit the objective of this invention.
As said other curable resin, other (meth) acrylic compounds other than the compound represented by Formula (1) etc. are mentioned, for example.
In the present specification, the “(meth) acryl” means acryl or methacryl, and the “(meth) acryl compound” means a compound having a (meth) acryloyl group. “Meth) acryloyl” means acryloyl or methacryloyl.

As said other (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, and (meth) acrylic acid and an epoxy compound are made to react. Epoxy (meth) acrylate obtained by this, urethane (meth) acrylate obtained by making the isocyanate compound react with the (meth) acrylic acid derivative which has a hydroxyl group, etc. are mentioned. Of these, epoxy (meth) acrylate is preferable. The (meth) acrylic compound preferably has two or more (meth) acryloyl groups in one molecule from the viewpoint of reactivity.
In addition, in this specification, the said "epoxy (meth) acrylate" represents the compound which made all the epoxy groups in an epoxy compound react with (meth) acrylic acid.

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

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

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

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

As an epoxy compound used as a raw material for synthesize | combining the said epoxy (meth) acrylate, the thing similar to the epoxy compound mentioned above can be used.

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).

In the urethane (meth) acrylate, for example, 1 equivalent of an isocyanate compound having two isocyanate groups is reacted with 2 equivalents of a (meth) acrylic acid derivative having a hydroxyl group in the presence of a catalytic amount of a tin compound. Can be obtained by:

Examples of the isocyanate compound include isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4′-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris (isocyanatophenyl) thiophosphate, tetramethylxylylene diene Isocyanate, 1,6,11-undecane triisocyanate and the like.

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 include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. And hydroxyalkyl mono (meth) acrylates such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, polyethylene glycol and the like mono (meta) ) Epoxy (meth) acrylates such as acrylate, mono (meth) acrylate or di (meth) acrylate of trivalent alcohols such as trimethylolethane, trimethylolpropane and glycerin, and bisphenol A type epoxy acrylate Etc. The.

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

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

The sealing agent for liquid crystal display elements of this invention contains a polymerization initiator and / or a thermosetting agent.
As the polymerization initiator, a radical polymerization initiator is preferably used.

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, thioxanthones, 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.

As said thermal radical polymerization initiator, what consists of an azo compound, an organic peroxide, etc. is mentioned, for example. Among these, a polymer azo initiator composed of a polymer azo compound 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) acryloyloxy 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 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 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 0.1 parts by weight and preferably 30 parts by weight with respect to 100 parts by weight of the entire curable resin. When the content of the polymerization initiator is within this range, the resulting sealing agent for liquid crystal display elements is more excellent in curability while maintaining excellent storage stability. A more preferable lower limit of the content of the polymerization initiator is 1 part by weight, a more preferable upper limit is 10 parts by weight, and a still more preferable upper limit is 5 parts by weight.

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

As for content of the said thermosetting agent, a preferable minimum is 1 weight part and a preferable upper limit is 50 weight part with respect to 100 weight part of whole curable resin. When the content of the thermosetting agent is within this range, the obtained sealing agent for a liquid crystal display element is more excellent in curability while maintaining excellent coating properties and storage stability. 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, further improving the adhesion due to the stress dispersion effect, improving the linear expansion coefficient, improving the moisture resistance of the cured product, 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 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 content of the said filler is this range, effects, such as an adhesive improvement, can be exhibited more, suppressing deterioration, such as applicability | paintability. The minimum with more preferable content of the said filler is 20 weight part, and a more preferable upper limit is 60 weight part.

The sealing agent for liquid crystal display elements of the present invention preferably contains a silane coupling agent for the purpose of further improving the adhesiveness. The silane coupling agent mainly has a role as an adhesion assistant for favorably bonding the sealing agent and the substrate.
As the silane coupling agent, for example, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane and the like are preferably used.

The minimum with preferable content of the said silane coupling agent in 100 weight part of sealing compounds for liquid crystal display elements of this invention is 0.1 weight part, and a preferable upper limit is 10 weight part. When the content of the silane coupling agent is within this range, the effect of improving the adhesiveness can be further exhibited while suppressing the occurrence of liquid crystal contamination. The minimum with more preferable content of the said silane coupling agent is 0.3 weight part, and a more preferable upper limit is 5 weight part.

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

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

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 viscosity and thixotropy of the obtained sealing agent for liquid crystal display elements are not greatly increased, and the coating property is excellent. 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 using a particle size distribution meter (for example, “NICOMP 380ZLS” manufactured by PARTICLE SIZING SYSTEMS).

The preferable lower limit of the content of the light-shielding agent in 100 parts by weight of the sealant for liquid crystal display elements of the present invention is 5 parts by weight, and the preferable upper limit is 80 parts by weight. When the content of the light-shielding agent is within this range, the effect of improving the light-shielding property is exhibited without lowering the adhesiveness, strength after curing, and drawing property of the obtained sealing agent for liquid crystal display elements. it can. The more preferable lower limit of the content of the light shielding agent is 10 parts by weight, the more preferable upper limit is 70 parts by weight, the still more preferable lower limit is 30 parts by weight, and the still more preferable upper limit is 60 parts by weight.

The sealing agent for liquid crystal display elements of the present invention is further added with a stress relaxation agent, reactive diluent, thixotropic agent, spacer, curing accelerator, antifoaming agent, leveling agent, polymerization inhibitor, etc., if necessary. An agent 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.

A vertical conducting material can be produced by blending conductive fine particles with the liquid crystal display element sealant of the present invention. The 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.

The sealing agent for liquid crystal display elements of this invention can be used suitably for manufacture of the liquid crystal display element by a liquid crystal dropping method.
As a method for producing the liquid crystal display element of the present invention by the liquid crystal dropping method, specifically, for example, a rectangular seal pattern is formed on the substrate by screen printing, dispenser application, etc. of the liquid crystal display element sealant of the present invention. A step of applying liquid crystal microdroplets to the entire surface of the transparent substrate in an uncured state of the sealant for the liquid crystal display element of the present invention, and immediately superimposing another substrate; and Examples of the method include a step of irradiating a seal pattern portion such as a sealing agent for liquid crystal display elements with light such as ultraviolet rays to temporarily cure the sealing agent, and a step of heating and temporarily curing the temporarily cured sealing agent. It is done.

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal display elements which can make adhesiveness and moisture permeability prevention property of hardened | cured material compatible can be provided. Moreover, according to this invention, the vertical conduction material and liquid crystal display element which use this sealing compound for liquid crystal display elements can be provided.

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

(Preparation of curable resin A)
To the reaction flask is added 130 parts by weight of 2-hydroxyethyl methacrylate, 148 parts by weight of phthalic anhydride, and 0.3 parts by weight of p-methoxyphenol as a polymerization inhibitor, and the mixture is stirred at 90 ° C. for 5 hours using a mantle heater. did. Next, 170 parts by weight of bisphenol A diglycidyl ether was added to the obtained reaction product, and the mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin A.
^{According to 1} H-NMR and ¹³ C-NMR, the curable resin A contains a compound represented by the above formula (1) (R ¹ is a methyl group, R ² is an ethylene group, Ar is a 1,2-phenylene group, n = 0, Ep was confirmed to be a structure derived from bisphenol A diglycidyl ether).

(Preparation of curable resin B)
To the reaction flask, 130 parts by weight of 2-hydroxyethyl methacrylate, 57 parts by weight of ε-caprolactone and 0.3 parts by weight of hydroquinone as a polymerization inhibitor were added and stirred at 90 ° C. for 5 hours using a mantle heater. 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours. Next, 170 parts by weight of bisphenol A diglycidyl ether was added to the obtained reaction product, and the resulting mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin B.
^{According to 1} H-NMR and ¹³ C-NMR, the curable resin B contains a compound represented by the above formula (1) (R ¹ is a methyl group, R ² is an ethylene group, Ar is a 1,2-phenylene group, X Was a ring-opening structure of ε-caprolactone, n = 0.48 (average value), and Ep was a structure derived from bisphenol A diglycidyl ether.

(Preparation of curable resin C)
To the reaction flask, 116 parts by weight of 2-hydroxyethyl acrylate, 57 parts by weight of ε-caprolactone, and 0.3 parts by weight of p-methoxyphenol as a polymerization inhibitor were added, and stirred at 90 ° C. for 5 hours using a mantle heater. After that, 198 parts by weight of naphthalic anhydride was added and further stirred for 5 hours. Next, 170 parts by weight of bisphenol A diglycidyl ether was added to the obtained reaction product, and the mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin C.
^{By 1} H-NMR and ¹³ C-NMR, the curable resin C was obtained from the compound represented by the above formula (1) (R ¹ is a hydrogen atom, R ² is an ethylene group, Ar is a 1,8-naphthylene group, X Was a ring-opening structure of ε-caprolactone, n = 0.47 (average value), and Ep was a structure derived from bisphenol A diglycidyl ether.

(Preparation of curable resin D)
To the reaction flask, 116 parts by weight of 2-hydroxyethyl acrylate, 148 parts by weight of phthalic anhydride, and 0.3 parts by weight of p-methoxyphenol as a polymerization inhibitor are added, and stirred at 90 ° C. for 5 hours using a mantle heater. did. Next, 170 parts by weight of bisphenol A diglycidyl ether was added to the obtained reaction product, and the mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin D.
^{According to 1} H-NMR and ¹³ C-NMR, the curable resin D is a compound represented by the above formula (1) (R ¹ is hydrogen, R ² is an ethylene group, Ar is a 1,2-phenylene group, n = 0, Ep was confirmed to be a structure derived from bisphenol A diglycidyl ether).

(Preparation of curable resin E)
To the reaction flask, 130 parts by weight of 2-hydroxyethyl methacrylate, 114 parts by weight of ε-caprolactone and 0.3 parts by weight of hydroquinone as a polymerization inhibitor were added and stirred at 90 ° C. for 5 hours using a mantle heater. 148 parts by weight of phthalic anhydride was added and further stirred for 5 hours. Next, 170 parts by weight of bisphenol A diglycidyl ether was added to the obtained reaction product, and the mixture was stirred at 90 ° C. for 5 hours to obtain a curable resin E.
^{According to 1} H-NMR and ¹³ C-NMR, the curable resin E has the following formula (1): R ¹ is a methyl group, R ² is an ethylene group, Ar is a 1,2-phenylene group, and X is ε-caprolactone. It was confirmed that the compound was a ring-opened structure, n = 1.02 (average value), and Ep was a structure derived from bisphenol A diglycidyl ether.

(Examples 1 to 7, Comparative Examples 1 to 3)
In accordance with the blending ratio described in Table 1, each material was stirred with a planetary stirrer (“Shinky Co., Ltd.,“ Awatori Netaro ”), and then uniformly mixed with a ceramic three roll. To 7 and Comparative Examples 1 to 3 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 Table 1.

(Adhesiveness)
1% by weight of a silica spacer (“SI-H055” manufactured by Sekisui Chemical Co., Ltd.) was added to each of the sealing agents for liquid crystal display elements obtained in Examples and Comparative Examples, and two glass substrates with an ITO thin film (25 × 45 mm) was finely dropped. The other glass substrate with an ITO thin film was bonded to this substrate in a cross shape, irradiated with 3000 mJ / cm ² ultraviolet rays with a metal halide lamp, and then heated at 120 ° C. for 60 minutes to obtain an adhesive test piece. When the edge part of the board | substrate in the produced adhesion test piece was pushed in at a speed | rate of 5 mm / min using the metal cylinder with a radius of 5 mm, the intensity | strength in case panel peeling occurred was measured. The value obtained by dividing the obtained measured value (kgf) by the seal diameter (cm) was 3.5 kgf / cm or more, “◎”, 3.0 kgf / cm or more and less than 3.5 kgf / cm The case was evaluated as “◯”, the case where it was 2.5 kgf / cm or more and less than 3.0 kgf / cm as “Δ”, and the case where it was less than 2.5 kgf / cm as “x”.

(Moisture permeability prevention)
Each of the sealing agents for liquid crystal display elements obtained in Examples and Comparative Examples was applied on a smooth release film using a coater so as to have a thickness of 200 to 300 μm. Subsequently, after irradiating 3000 mJ / cm < ² > of ultraviolet-rays using a metal halide lamp, the film for moisture permeability measurement was obtained by heating at 120 degreeC for 60 minutes. A moisture permeability test cup was prepared by a method according to JIS Z 0208 for moisture-proof packaging materials (cup method), the obtained moisture permeability measurement film was attached, and the temperature was 80 ° C. and humidity was 90% RH. The moisture permeability was measured by putting in a constant humidity oven. The case where the obtained moisture permeability value is less than 50 g / m ² · 24 hr is “◎”, and the case where it is 50 g / m ² · 24 hr or more and less than 60 g / m ² · 24 hr is “◯”, 60 g / m m ² · 24 hr or more ^{70 g} / m where the a was less than 2 · 24 hr or "△", was evaluated anti-moisture permeability as "×" the case was ^70g / m 2 · 24hr or more.

(Display performance of liquid crystal display elements)
In each of the sealing agents for liquid crystal display elements obtained in Examples and Comparative Examples, 1% by weight of a silica spacer (“SI-H055” manufactured by Sekisui Chemical Co., Ltd.) is blended, defoamed, After removing the foam, it was filled into a syringe for dispensing (“PSY-10E” manufactured by Musashi Engineering Co., Ltd.), and defoamed again. Next, using a dispenser (“SHOTMASTER 300” manufactured by Musashi Engineering Co., Ltd.), a sealing agent was applied so as to draw a frame on one of the two glass substrates with an ITO thin film. Subsequently, fine droplets of TN liquid crystal (manufactured by Chisso Corp., “JC-5001LA”) are dropped onto the sealant frame using a liquid crystal dropping device, and the other glass substrate with an ITO thin film is stacked on the vacuum bonding device. The two substrates were bonded together under a reduced pressure of 5 Pa. The cell after pasting was irradiated with 3000 mJ / cm ² ultraviolet rays with a metal halide lamp, and then the sealing agent was thermally cured by heating at 120 ° C. for 60 minutes, thereby producing a liquid crystal display element. The obtained liquid crystal display element was stored for 72 hours in an environment of a temperature of 80 ° C. and a humidity of 90% RH, and then driven with a voltage of AC 3.5 V, and the presence or absence of display unevenness (color unevenness) was visually observed. “◎” indicates that no display unevenness is observed at the periphery of the liquid crystal display element, “○” indicates that display is slightly thin, and “△” indicates that there is clear dark display unevenness. The display performance of the liquid crystal display element was evaluated as “x” when the dark display unevenness was extended not only to the peripheral part but also to the central part.
Note that the liquid crystal display elements with the evaluations “◎” and “で” 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 and a polymerization initiator and / or a thermosetting agent,
The curable resin contains a compound represented by the following formula (1),
A sealing agent for a liquid crystal display element, wherein the content of the compound represented by the formula (1) in 100 parts by weight of the curable resin is 1 to 90 parts by weight.

In the formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2 represents a group represented by the following formula (2-1), (2-2), or (2-3) , Ar represents an optionally substituted arylene group, X represents a ring-opening structure of a cyclic lactone, n is 0 to 0.5 (average value), and Ep is a structure derived from an epoxy compound Represents.

In formulas (2-1) to (2-3), * represents a bonding position, in formula (2-2), a is an integer of 1 to 8, and in formula (2-3), b Is an integer from 1 to 8, c is an integer from 1 to 3, and d is an integer from 1 to 8.
The compound represented by the formula (1) is characterized in that n is 0 and Ep is a structure derived from a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, or a bisphenol E type epoxy compound. The sealing agent for liquid crystal display elements of Claim 1.
The sealing agent for liquid crystal display elements according to claim 1, wherein the curable resin contains an epoxy compound.
The sealing agent for liquid crystal display elements according to claim 1, 2 or 3, further comprising a light shielding agent.
A vertical conduction material comprising the sealing agent for liquid crystal display elements according to claim 1, and conductive fine particles.
A liquid crystal display element comprising the sealant for a liquid crystal display element according to claim 1, or the vertical conduction material according to claim 5.