WO2014199853A1 - Sealing agent for liquid crystal dropping methods, vertically conducting material, and liquid crystal display element - Google Patents

Abstract

One purpose of the present invention is to provide a sealing agent for liquid crystal dropping methods, which has excellent bonding properties and provides a cured product that has low water vapor permeability. Another purpose of the present invention is to provide a vertically conducting material and a liquid crystal display element, each of which is obtained using the sealing agent for liquid crystal dropping methods. The present invention is a sealing agent for liquid crystal dropping methods, which contains a curable resin and a radical polymerization initiator and/or a thermal curing agent. The curable resin contains an epoxy resin and a (meth)acrylic resin, and the amount of the epoxy resin contained in 100 parts by weight of the curable resin is 5-70 parts by weight. In addition, the epoxy resin contains 20% by weight or more of a dicyclopentadiene novolac epoxy resin.

Description

Liquid crystal dropping method sealing agent, vertical conduction material, and liquid crystal display element

The present invention relates to a sealant for a liquid crystal dropping method having excellent adhesiveness and low moisture permeability 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 dropping methods.

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, the film is heated and subjected to main curing to produce a liquid crystal display element. 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.

With the widespread use of tablets and mobile devices, liquid crystal display elements are increasingly required to have moisture resistance reliability in driving in high-temperature and high-humidity environments, and the performance of sealing agents to prevent water from entering from the outside. Is further demanded. In order to improve the moisture resistance reliability of the liquid crystal display element, it is necessary to improve the adhesiveness between the sealing agent and the substrate and to reduce the moisture permeability of the cured product of the sealing agent. However, it has been difficult to achieve both high adhesiveness and low moisture permeability in the sealing agent.

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

An object of this invention is to provide the sealing compound for liquid crystal dropping methods which is excellent in adhesiveness and the moisture permeability of hardened | cured material is low. Moreover, an object of this invention is to provide the vertical conduction material and liquid crystal display element which use this sealing compound for liquid crystal dropping methods.

The present invention is a sealing agent for a liquid crystal dropping method containing a curable resin and a radical polymerization initiator and / or a thermosetting agent, and the curable resin contains an epoxy resin and a (meth) acrylic resin. In addition, the content of the epoxy resin in 100 parts by weight of the curable resin is 5 to 70 parts by weight, and the epoxy resin contains 20% by weight or more of a dicyclopentadiene novolac type epoxy resin. Sealing agent.
The present invention is described in detail below.

The present inventor can obtain a liquid crystal dropping method sealing agent having excellent adhesion and low moisture permeability of a cured product by blending a specific amount of a dicyclopentadiene novolac type epoxy resin as a curable resin. The headline and the present invention have been completed.

The sealing agent for liquid crystal dropping method of the present invention contains a curable resin.
The curable resin contains an epoxy resin.
The epoxy resin contains a dicyclopentadiene novolac type epoxy resin. By containing the said dicyclopentadiene novolak type epoxy resin, the sealing agent for liquid crystal dropping methods of this invention can make high adhesiveness and low moisture permeability compatible.

Specific examples of the dicyclopentadiene novolac epoxy resin include compounds represented by the following formula (1).

In the formula (1), n is 1 to 5, and is preferably 1.

Examples of commercially available dicyclopentadiene novolac epoxy resins include HP-7200 and HP-7200L (both manufactured by DIC).

The epoxy resin may contain other epoxy resins in addition to the dicyclopentadiene novolac type epoxy resin.
When it contains the said other epoxy resin, the minimum of content of the said dicyclopentadiene novolak-type epoxy resin in the said epoxy resin is 20 weight%. When the content of the dicyclopentadiene novolac epoxy resin is less than 20% by weight, the resulting liquid crystal dropping method sealing agent does not sufficiently exhibit the effect of achieving both high adhesiveness and low moisture permeability. The minimum with more preferable content of the said dicyclopentadiene novolak-type epoxy resin is 25 weight%. The epoxy resin is preferably composed only of the dicyclopentadiene novolac type epoxy resin.
Moreover, it is preferable that content of the said dicyclopentadiene novolak-type epoxy resin in 100 weight part of curable resin is less than 70 weight part. When the content of the dicyclopentadiene novolac type epoxy resin is 70 parts by weight or more, the viscosity of the resulting liquid crystal dropping method sealing agent becomes too high, and the applicability may deteriorate. The content of the dicyclopentadiene novolac epoxy resin is more preferably 30 parts by weight or less, and still more preferably 10 parts by weight or less.

Examples of the other epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, 2,2′-diallyl bisphenol A type epoxy resins, hydrogenated bisphenol A type epoxy resins, and propylene oxide. Addition bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin other than dicyclopentadiene novolak type, naphthalene type epoxy resin, phenol novolac type epoxy Resin, ortho-cresol novolac epoxy resin, biphenyl novolac epoxy resin, naphthalenephenol novolac epoxy resin, glycidyl resin Emission type epoxy resin, alkyl polyol type epoxy resin, rubber modified epoxy resin, glycidyl ester compounds, bisphenol A type episulfide resins. These epoxy resins may be used independently and 2 or more types may be used in combination.

Examples of commercially available bisphenol A type epoxy resins include jER 828, jER 1004 (all manufactured by Mitsubishi Chemical Corporation), EPICLON 850CRP (manufactured by DIC Corporation), and the like.
Examples of commercially available bisphenol F-type epoxy resins include jER 806, jER 4004, jER YL983U (all manufactured by Mitsubishi Chemical Corporation).
As what is marketed among the said bisphenol S-type epoxy resins, EPICLON EXA1514 (made by DIC Corporation) etc. are mentioned, for example.
Examples of commercially available 2,2′-diallylbisphenol A type epoxy resins include RE-810NM (manufactured by Nippon Kayaku Co., Ltd.).
Examples of commercially available hydrogenated bisphenol A type epoxy resins include EPICLON EXA7015 (manufactured by DIC), jER YX8000 (manufactured by Mitsubishi Chemical Corporation), and the like.
Examples of commercially available propylene oxide-added bisphenol A type epoxy resins include EP-4000S (manufactured by ADEKA).
Examples of commercially available resorcinol type epoxy resins include EX-201 (manufactured by Nagase ChemteX Corporation).
Examples of commercially available biphenyl type epoxy resins include jER YX-4000H (manufactured by Mitsubishi Chemical Corporation).
Examples of commercially available sulfide type epoxy resins include YSLV-50TE (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.).
Examples of commercially available diphenyl ether type epoxy resins include YSLV-80DE (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.).
Examples of commercially available dicyclopentadiene type epoxy resins other than the above-mentioned dicyclopentadiene novolak type include EP-4088S (manufactured by ADEKA).
Examples of commercially available naphthalene type epoxy resins include EPICLON HP4032, EPICLON EXA-4700 (both manufactured by DIC), and the like.
Examples of commercially available phenol novolac epoxy resins include EPICLON N-770 (manufactured by DIC).
Examples of commercially available ortho cresol novolac type epoxy resins include EPICLON N-670-EXP-S (manufactured by DIC).
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 jER 630 (manufactured by Mitsubishi Chemical), EPICLON 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.), EPICLON 726 (manufactured by DIC Corporation), Epolite 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.), Denacol EX-611. (Manufactured by Nagase ChemteX Corporation).
Examples of commercially available rubber-modified epoxy resins include YR-450, YR-207 (both manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) and Epolide PB (manufactured by Daicel Chemical Industries, Ltd.).
Examples of commercially available glycidyl ester compounds include Denacol EX-147 (manufactured by Nagase ChemteX Corporation).
Examples of commercially available bisphenol A type episulfide resins include jER YL-7000 (manufactured by Mitsubishi Chemical Corporation).
Other commercially available epoxy 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.), jER 1031 and jER 1032. (Both manufactured by Mitsubishi Chemical Corporation), EXA-7120 (manufactured by DIC), and the like.

Moreover, you may contain resin which has an epoxy group and a (meth) acryloyloxy group in 1 molecule as said other epoxy resin. Examples of such a compound include a partial (meth) acryl-modified epoxy resin obtained by reacting a part of an epoxy group of a compound having two or more epoxy groups with (meth) acrylic acid. The partial (meth) acryl-modified epoxy resin is treated as an epoxy resin, not a (meth) acrylic resin described later.
In addition, you may use the partial (meth) acryl modified epoxy resin obtained by making the epoxy group of a part of said dicyclopentadiene novolak type epoxy resin react with (meth) acrylic acid.

Specifically, as the partial (meth) acryl-modified epoxy resin, for example, 190 g of a phenol novolac type epoxy resin (manufactured by DIC, “N-770”) is dissolved in 500 mL of toluene, and triphenylphosphine, 0.03 wt. 1 g was added to obtain a uniform solution, and 35 g of acrylic acid was added dropwise to the obtained solution under reflux stirring for 2 hours, followed by further refluxing stirring for 6 hours, and then removal of toluene to remove 50 mol%. A partially acryl-modified phenol novolac type epoxy resin in which an epoxy group has reacted with acrylic acid can be obtained (in this case, 50% partially acryl-modified).

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

The lower limit of the content of the epoxy resin in 100 parts by weight of the curable resin is 5 parts by weight, and the upper limit is 70 parts by weight. When the content of the epoxy resin is less than 5 parts by weight, the content of the dicyclopentadiene novolac type epoxy resin decreases, so that the obtained liquid crystal dropping method sealing agent has high adhesiveness and low moisture permeability. It becomes impossible to make it compatible. If the content of the epoxy resin exceeds 70 parts by weight, liquid crystal contamination is likely to occur. The preferable lower limit of the content of the epoxy resin is 10 parts by weight, the preferable upper limit is 65 parts by weight, the more preferable lower limit is 15 parts by weight, and the more preferable upper limit is 60 parts by weight.
Moreover, the preferable minimum of content of the epoxy resin except the said partial (meth) acryl modified epoxy resin in 100 weight part of the said curable resin is 3 weight part, and a preferable upper limit is 59 weight part. When the content of the epoxy resin excluding the partial (meth) acrylic-modified epoxy resin is less than 3 parts by weight, the content of the dicyclopentadiene novolac epoxy resin is reduced, and thus the obtained sealing agent for liquid crystal dropping method is , High adhesiveness and low moisture permeability may not be compatible. When the content of the epoxy resin excluding the partial (meth) acryl-modified epoxy resin exceeds 59 parts by weight, liquid crystal contamination may occur. The more preferable lower limit of the content of the epoxy resin is 5 parts by weight, the preferable upper limit is 30 parts by weight, and the more preferable upper limit is 20 parts by weight.

The curable resin contains a (meth) acrylic resin.
The (meth) acrylic resin is, for example, an ester compound obtained by reacting (meth) acrylic acid with a compound having a hydroxyl group, or an epoxy (meth) obtained by reacting (meth) acrylic acid with an epoxy compound. Examples thereof include urethane (meth) acrylate obtained by reacting acrylate and isocyanate with a (meth) acrylic acid derivative having a hydroxyl group.
In the present specification, the (meth) acrylic resin means a resin having a (meth) acryloyl group, and the (meth) acryloyl group means an acryloyl group or a methacryloyl group. Moreover, the said (meth) acrylate means an acrylate or a methacrylate. The said epoxy (meth) acrylate means what all the epoxy groups of the epoxy compound reacted with (meth) acrylic acid.
Among these, the (meth) acrylic resin may contain a dicyclopentadiene novolac epoxy (meth) acrylate formed by reacting all the epoxy groups of the dicyclopentadiene novolac epoxy resin with (meth) acrylic acid. preferable.

Examples of the monofunctional compounds of the ester compounds include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, Isobutyl (meth) acrylate, t-butyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-methoxyethyl (meth) ) Acrylate, methoxyethylene glycol (meth) acrylate, 2-ethoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, ethylcal Tall (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, imide (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl ( (Meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isononyl (Meth) acrylate, isomyristyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, bicyclopentenyl (meth) acrylate, isodecyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethyl Aminoethyl (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl 2-hydroxypropyl phthalate, glycidyl ( And (meth) acrylate and 2- (meth) acryloyloxyethyl phosphate.

Examples of the bifunctional ester compound include 1,4-butanediol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,6-hexanediol 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 (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (me ) Acrylate, propylene oxide-added bisphenol A di (meth) acrylate, ethylene oxide-added bisphenol A di (meth) acrylate, ethylene oxide-added bisphenol F di (meth) acrylate, dimethylol dicyclopentadienyl di (meth) acrylate, 1,3 -Butylene glycol 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 di (meth) acrylate.

Examples of the ester compound having three or more functional groups include pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, propylene oxide-added trimethylolpropane tri (meth) acrylate, and ethylene oxide-added trimethylolpropane tri. (Meth) acrylate, caprolactone-modified trimethylolpropane tri (meth) acrylate, ethylene oxide-added isocyanuric acid tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane tetra (meth) ) Acrylate, pentaerythritol tetra (meth) acrylate, glycerin tri (meth) acrylate, propylene oxide De additional glycerin tri (meth) acrylate, tris (meth) acryloyloxyethyl phosphate, and the like.

Examples of the epoxy (meth) acrylate include those obtained by reacting an epoxy resin 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 resin mentioned above can be used.

Specific examples of the epoxy (meth) acrylate include 360 parts by weight of a resorcinol type epoxy resin (manufactured by Nagase ChemteX Corporation, “EX-201”), 2 parts by weight of p-methoxyphenol as a polymerization inhibitor, and a reaction catalyst. Resorcinol-type epoxy acrylate can be obtained by reacting 2 parts by weight of triethylamine and 210 parts by weight of acrylic acid at 90 ° C. while refluxing and stirring for 5 hours.

Examples of commercially available epoxy (meth) acrylates include EBECRYL860, EBECRYL3200, EBECRYL3201, EBECRYL3412, EBECRYL3600, EBECRYL3700, EBECRYL3701, EBECRYL3702, EBECRY370R ), EA-1010, EA-1020, EA-5323, EA-5520, EA-CHD, EMA-1020 (all manufactured by Shin-Nakamura Chemical Co., Ltd.), epoxy ester M-600A, epoxy ester 40EM, epoxy ester 70PA, Epoxy ester 200PA, Epoxy ester 80MF Epoxy ester 3002M, Epoxy ester 3002A, Epoxy ester 1600A, Epoxy ester 3000M, Epoxy ester 3000A, Epoxy ester 200EA, Epoxy ester 400EA (all manufactured by Kyoeisha Chemical Co., Ltd.), Denacol acrylate DA-141, Denacol acrylate DA-314 And Denacol acrylate DA-911 (all manufactured by Nagase ChemteX Corporation).

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

Examples of the isocyanate used as a raw material for the urethane (meth) acrylate include isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, 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, tetramethylxylene diisocyanate, 1,6,10-undecane triisocyanate Doors and the like.

Moreover, as an isocyanate used as a raw material of urethane (meth) acrylate obtained by reacting the above-mentioned isocyanate with a (meth) acrylic acid derivative having a hydroxyl group, ethylene glycol, glycerin, sorbitol, trimethylolpropane, (poly) propylene glycol It is also possible to use chain-extended isocyanate compounds obtained by reaction of polyols such as carbonate diols, polyether diols, polyester diols, polycaprolactone diols and excess isocyanates.

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

Specific examples of the urethane (meth) acrylate include, for example, 134 parts by weight of trimethylolpropane, 0.2 part by weight of BHT as a polymerization inhibitor, 0.01 part by weight of dibutyltin dilaurate as a reaction catalyst, and 666 parts by weight of isophorone diisocyanate. In addition, the mixture can be reacted at 60 ° C. with stirring under reflux for 2 hours, and then 51 parts by weight of 2-hydroxyethyl acrylate is added, and the mixture is reacted at 90 ° C. with stirring at reflux for 2 hours while feeding air.

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-122P, U-108A, U-340P, U- 4HA, U-6HA, U-324A, U-15HA, UA-5201P, UA-W2A, U-1084A, U-6LPA, U-2HA, U-2PHA, UA-4100, UA-7100, UA-4200, UA-4400, UA-340P, U-3HA, UA-7200, U-2061BA, U-10H, U-122A, U-340A, U-108, U-6H, UA-4000 (all Shin-Nakamura Chemical Industries ), AH-600, AT-600, UA-306H, AI-600, UA-101T, UA-101I, A-306T, UA-306I (all manufactured by Kyoeisha Chemical Co., Ltd.).

The (meth) acrylic resin preferably has a hydrogen-bonding unit such as —OH group, —NH— group, —NH ₂ group and the like from the viewpoint of suppressing adverse effects on the liquid crystal. (Meth) acrylate is particularly preferred.
The (meth) acrylic resin preferably has 2 to 3 (meth) acryloyl groups in the molecule because of its high reactivity.

The sealing agent for liquid crystal dropping method of the present invention contains a radical polymerization initiator and / or a thermosetting agent.
Examples of the radical polymerization initiator include a photo radical polymerization initiator and a thermal radical polymerization initiator.

Examples of the photo radical polymerization initiator include benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, 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, IRGACUREOXE01, and Lucirin TPO (all manufactured by BASF 30, manufactured by BASF 30 SPEEDCURE EMK (manufactured by DKSH Japan), benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.) and the like.

Examples of the thermal radical polymerization initiator include peroxides and azo compounds. Among these, a polymer azo initiator composed of a polymer azo compound is preferable.
In the present specification, the polymer azo initiator 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 polymer azo initiator is less than 1000, the polymer azo initiator may adversely affect the liquid crystal. When the number average molecular weight of the polymeric azo initiator exceeds 300,000, mixing with the curable resin may be difficult. 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 include polycondensates of polydimethylsiloxane having a terminal amino group.

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

Examples of commercially available thermal radical polymerization initiators include perbutyl O, perhexyl O, perbutyl PV (all manufactured by NOF Corporation), V-30, V-501, V-601, VPE-0201. VPE-0401, VPE-0601 (both manufactured by Wako Pure Chemical Industries, Ltd.) and the like.

The content of the radical 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 radical polymerization initiator is less than 0.01 part by weight, the obtained sealing agent for liquid crystal dropping method may not be sufficiently cured. When content of the said radical polymerization initiator exceeds 10 weight part, storage stability may fall.

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 (hydrazinocarbonoethyl) -5-isopropylhydantoin, sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, malonic acid dihydrazide, and the like. Examples of such products include SDH (manufactured by Nippon Finechem Co., Ltd.), ADH (manufactured by Otsuka Chemical Co., Ltd.), Amicure VDH, Amicure VDH-J, Amicure UDH (all manufactured by Ajinomoto Fine Techno Co., Ltd.), and the like.

The content of the thermosetting agent is preferably 1 part by weight with respect to 100 parts by weight of the curable resin, and 50 parts by weight with respect to the preferable upper limit. When the content of the thermosetting agent is less than 1 part by weight, the sealing agent for liquid crystal dropping method of the present invention may not be sufficiently cured. When content of the said thermosetting agent exceeds 50 weight part, the viscosity of the sealing compound for liquid crystal dropping methods of this invention will become high, and coating property may deteriorate. The upper limit with more preferable content of the said thermosetting agent is 30 weight part.

The sealing agent for liquid crystal dropping method of the present invention preferably contains a curing accelerator. The dicyclopentadiene novolac type epoxy resin needs to be heated at a relatively high temperature in order to be sufficiently cured, but by using the curing accelerator, it can be cured sufficiently without being heated at a high temperature. And the effect of achieving both high adhesiveness and low moisture permeability is sufficiently exhibited.

Examples of the curing accelerator include imidazole-based curing accelerators, thiol-based curing accelerators, and tertiary amine-based curing accelerators. Among them, it is preferable to contain an imidazole-based curing accelerator and / or a thiol-based curing accelerator because the curing rate is high and the viscosity increase rate at room temperature is low.

Examples of the imidazole curing accelerator include 1-cyanoethyl-2-phenylimidazole, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2- And phenyl-4-methyl-5-hydroxymethylimidazole.

Examples of the thiol-based curing accelerator include trimethylolpropane tristhioglycolate, trimethylolethane tristhioglycolate, and the like.

As for content of the said hardening accelerator, a preferable minimum is 1 weight part and a preferable upper limit is 10 weight part with respect to 100 weight part of said curable resins. When the content of the curing accelerator is less than 1 part by weight, the obtained liquid crystal dropping method sealing agent may not be sufficiently cured, or heating at a high temperature may be required for curing. When content of the said hardening accelerator exceeds 10 weight part, the sealing compound for liquid crystal dropping methods obtained may become inferior to adhesiveness.

The sealing agent for liquid crystal dropping method of the present invention may further contain a filler for the purpose of improving the adhesiveness by the stress dispersion effect, improving the linear expansion coefficient, and the like.
Examples of the filler include talc, asbestos, silica, diatomaceous earth, smectite, bentonite, calcium carbonate, magnesium carbonate, alumina, montmorillonite, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, and hydroxide. Examples include inorganic fillers such as aluminum, glass beads, silicon nitride, barium sulfate, gypsum, calcium silicate, sericite activated clay, and aluminum nitride, and organic fillers such as polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, and acrylic polymer fine particles. It is done.

The minimum with preferable content of the said filler in 100 weight part of sealing agents for liquid crystal dropping methods of this invention is 5 weight part, and a preferable upper limit is 70 weight part. When the content of the filler is less than 5 parts by weight, effects such as improvement of adhesiveness may not be sufficiently exhibited. When content of the said filler exceeds 70 weight part, the viscosity of the sealing compound for liquid crystal dropping methods obtained will become high too much, and coating property may deteriorate. The minimum with more preferable content of the said filler is 10 weight part, and a more preferable upper limit is 60 weight part.

The sealing agent for liquid crystal dropping method of the present invention may contain a silane coupling agent.
As the silane coupling agent, for example, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane and the like are preferably used. These may be used independently and 2 or more types may be used together.

The minimum with preferable content of the said silane coupling agent in 100 weight part of sealing agents for liquid crystal dropping methods of this invention is 0.1 weight part, and a preferable upper limit is 20 weight part. When the content of the silane coupling agent is less than 0.1 parts by weight, the effect of blending the silane coupling agent may not be sufficiently exhibited. When content of the said silane coupling agent exceeds 20 weight part, the sealing compound for liquid crystal dropping methods obtained may cause liquid-crystal contamination. The minimum with more preferable content of the said silane coupling agent is 0.5 weight part, and a more preferable upper limit is 10 weight part.

The sealing agent for liquid crystal dropping method of the present invention may contain a light shielding agent. By containing the said light shielding agent, the sealing compound for liquid crystal dropping methods 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 light shielding properties to the sealing agent for liquid crystal dropping method of the present invention, while transmitting light having a wavelength in the vicinity of the ultraviolet region. A shading agent. Therefore, by using the photo radical polymerization initiator or the photo cationic polymerization initiator that can start the reaction with light having a wavelength (370 to 450 nm) at which the transmittance of the titanium black is high, the liquid crystal of the present invention is used. The photocurability of the sealing agent for the dripping method can be further increased. On the other hand, the light shielding agent contained in the liquid crystal dropping method sealing agent of the present invention is preferably a highly insulating material, and titanium black is also suitable as the highly insulating light shielding agent.
The titanium black preferably has an optical density (OD value) per μm of 3 or more, more preferably 4 or more. The higher the light-shielding property of the titanium black, the better. The OD value of the titanium black is not particularly limited, but is usually 5 or less.

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

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

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

The primary particle diameter of the light-shielding agent is not particularly limited as long as it is not more than the distance between the substrates of the liquid crystal display element, but the preferred lower limit is 1 nm and the preferred upper limit is 5 μm. When the primary particle diameter of the light-shielding agent is less than 1 nm, the viscosity and thixotropy of the obtained liquid crystal dropping method sealing agent are greatly increased, and workability may be deteriorated. When the primary particle diameter of the light-shielding agent exceeds 5 μm, the coating property of the obtained liquid crystal dropping method sealing agent on the substrate may be deteriorated. 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 preferable lower limit of the content of the light shielding agent in 100 parts by weight of the sealing agent for liquid crystal dropping method of the present invention is 5 parts by weight, and the preferable upper limit is 80 parts by weight. If the content of the light shielding agent is less than 5 parts by weight, sufficient light shielding properties may not be obtained. When the content of the light-shielding agent exceeds 80 parts by weight, the adhesion of the obtained sealing agent for liquid crystal dropping method to the substrate and the strength after curing may be lowered, or the drawing property may be lowered. 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 the liquid crystal dropping method of the present invention further includes a reactive diluent for adjusting the viscosity, a thixotropic agent for adjusting thixotropy, a spacer such as a polymer bead for adjusting the panel gap, an eraser, if necessary. You may contain other well-known additives, such as a foaming agent, a leveling agent, and a polymerization inhibitor.

As a method for producing the sealing agent for liquid crystal dropping method of the present invention, for example, a curable resin, a radical polymerization initiator and / or a thermosetting agent, a silane coupling agent added as necessary, and the like are homogenized. The method of mixing using mixers, such as a disper, a homomixer, a universal mixer, a planetary mixer, a kneader, and 3 rolls, is mentioned.

A vertical conduction material can be produced by blending conductive fine particles with the sealant for the liquid crystal dropping method of the present invention. If such a vertical conduction material is used, the electrodes can be reliably conductively connected.
The vertical conduction material containing the sealing agent for liquid crystal dropping method of the present invention and conductive fine particles is also one aspect of the present invention.

As said electroconductive fine particles, what formed the conductive metal layer on the surface of a metal ball, resin microparticles | fine-particles etc. can be used, for example. Among them, the one in which the conductive metal layer is formed on the surface of the resin fine particles is preferable because the conductive connection is possible without damaging the transparent substrate due to the excellent elasticity of the resin fine particles.

The liquid crystal display element using the sealing agent for liquid crystal dropping method of the present invention or the vertical conduction material of the present invention is also one aspect of the present invention.
As a method for producing the liquid crystal display element of the present invention, for example, the liquid crystal dropping method sealing agent of the present invention is applied to one of two substrates having an ITO thin film by screen printing, dispenser application, etc. The step of forming the seal pattern, the step of applying the liquid crystal droplets to the entire surface of the frame of the seal pattern, the step of superposing the other substrate under vacuum, and applying the light such as ultraviolet rays to the sealant for the liquid crystal dropping method of the present invention Examples of the method include a step of irradiating and temporarily curing the sealant, and a step of heating and temporarily curing the temporarily cured sealant.

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal dropping methods with excellent adhesiveness and low moisture permeability of hardened | cured material 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 dropping methods 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.

(Example 1)
5 parts by weight of a dicyclopentadiene novolac type epoxy resin (manufactured by DIC, “EPICLON HP-7200”) as a curable resin, 95 parts by weight of a bisphenol A type epoxy methacrylate as a (meth) acrylic resin, and diphenyl as a radical photopolymerization initiator ( 2,4,6-trimethoxybenzoyl) phosphine oxide (BASF Japan, “Lucirin TPO”) 1.5 parts by weight, malonic acid dihydrazide (Nihon Finechem, “MDH”) 1.1 wt. 2 parts by weight of 2-undecylimidazole as a curing accelerator, 10 parts by weight of talc (manufactured by Nippon Talc Co., Ltd., “Nanoace D-600F”), and 3-glycidoxypropyl as a silane coupling agent Trimethoxysilane (manufactured by Chisso Corporation, “S510 ) After mixing 1.5 parts by weight using a planetary stirrer (Shinky Co., Ltd. “Awatori Netaro”), the mixture is further mixed using three rolls for the liquid crystal dropping method of Example 1. A sealant was prepared.

(Examples 2 to 15, Comparative Examples 1 to 9)
Sealants for liquid crystal dropping methods of Examples 2 to 15 and Comparative Examples 1 to 9 were prepared in the same manner as in Example 1 except that the materials having the blending ratios shown in Tables 1 to 3 were used.

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

(1) Coating property Each liquid crystal dropping method sealant obtained in Examples and Comparative Examples was filled into a dispensing syringe ("PSY-10E" manufactured by Musashi Engineering Co., Ltd.), and defoamed. Next, using a dispenser (“SHOTMASTER 300” manufactured by Musashi Engineering Co., Ltd.), a sealing agent was applied so as to draw a rectangular frame on one of the two transparent electrode substrates with an ITO thin film. Subsequently, fine droplets of TN liquid crystal (manufactured by Chisso Corporation, “JC-5001LA”) were applied dropwise with a liquid crystal dropping device, and the other transparent substrate was bonded with a vacuum laminating device under a reduced pressure of 5 Pa. The cells after bonding were irradiated with 3000 mJ / cm ² ultraviolet rays with a metal halide lamp and then heated at 120 ° C. for 60 minutes to thermally cure the sealing agent, and 100 liquid crystal display elements were produced for each sealing agent. . When the obtained liquid crystal display element was observed, the number of breaks in the seal portion was “◎” when it was 0, “◯” when it was 1-3, and 4-10. The applicability was evaluated with “Δ” as the case when the number was 11 and “x” when the number was 11 or more.

(2) Adhesiveness 1% by weight of a silica spacer (Sekisui Chemical Co., Ltd., “SI-H055”) was added to each liquid crystal dropping method sealing agent obtained in the Examples and Comparative Examples, and two ITO films After irradiating 3000 mJ / cm ² of ultraviolet rays with a metal halide lamp, the glass test piece (30 × 40 mm) with a fine drop was applied to one of the attached glass test pieces and the other glass test piece was laminated in a cross shape. An adhesion test piece was obtained by heating at 120 ° C. for 60 minutes. A tensile test (5 mm / sec) was performed by placing chucks above and below the adhesion test piece. The resulting value obtained by dividing measured values (kgf) in the seal coating cross sectional area (cm ²⁾ is a case was 60 kgf / cm ² or more "◎" was 40 kgf / cm ² or more 60 kgf / cm less than ² where "○" was evaluated adhesion where was 10 kgf / cm ² or more 40 kgf / cm less than ² as "△", if less than 10 kgf / cm ² "×".

(3) Moisture resistance of cured product Each of the sealing agents for liquid crystal dropping method obtained in Examples and Comparative Examples was applied on a smooth release film with a coater to a thickness of 200 to 300 μm. Subsequently, after irradiating 3000 mJ / cm < ² > of ultraviolet-rays with a metal halide lamp, the film for moisture permeability measurement was obtained by heating at 120 degreeC for 60 minutes. A moisture permeation test cup is prepared by a method according to JIS Z 0208 for moisture proof packaging materials (cup method), and the obtained moisture permeation measuring film is attached to an oven at a temperature of 80 ° C. and a humidity of 90% RH. The moisture permeability was measured. The obtained value of the moisture permeability, the case was less than ^50g / m 2 · 24hr "◎", the case was less than ^50g / m 2 · 24hr or more ^70g / m 2 · 24hr "○", 70g / m "△" and if it was less than ² · 24 hr or more 100g ^/ m 2 · 24hr, to evaluate moisture resistance of the cured product when was 100 g ^/ m 2 · 24 hr or more as "×".

(4) Display performance of liquid crystal display element (evaluation of color unevenness of liquid crystal display element driven after storage under high temperature and high humidity)
The liquid crystal dropping method sealant obtained in each Example and each Comparative Example was filled in a dispensing syringe (“PSY-10E” manufactured by Musashi Engineering Co., Ltd.) and subjected to defoaming treatment. Next, using a dispenser (“SHOTMASTER 300” manufactured by Musashi Engineering Co., Ltd.), a sealing agent was applied so as to draw a rectangular frame on one of the two transparent electrode substrates with an ITO thin film. Subsequently, fine droplets of TN liquid crystal (manufactured by Chisso Corporation, “JC-5001LA”) were applied dropwise with a liquid crystal dropping device, and the other transparent substrate was bonded with a vacuum laminating device under a reduced pressure of 5 Pa. The cells after bonding are irradiated with 3000 mJ / cm ² ultraviolet rays with a metal halide lamp and then heated at 120 ° C. for 60 minutes to thermally cure the sealing agent, thereby producing five liquid crystal display elements for each sealing agent. did. The obtained liquid crystal display element was stored for 36 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 periphery of the halftone sealant was visually observed. "◎" when no color unevenness is seen around the sealant part, "○" when a little light color unevenness is seen, "△" when there is a clear dark color unevenness, no power supply The case where color unevenness was seen was evaluated as “x”.

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal dropping methods with excellent adhesiveness and low moisture permeability of hardened | cured material 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 dropping methods can be provided.

Claims (7)

1. A sealing agent for a liquid crystal dropping method comprising a curable resin, a radical polymerization initiator and / or a thermosetting agent,
   The curable resin contains an epoxy resin and a (meth) acrylic resin,
   The content of the epoxy resin in 100 parts by weight of the curable resin is 5 to 70 parts by weight, and the epoxy resin contains 20% by weight or more of a dicyclopentadiene novolac type epoxy resin. Sealant for liquid crystal dropping method.
2. The sealing agent for a liquid crystal dropping method according to claim 1, further comprising a curing accelerator.
3. The sealing agent for liquid crystal dropping method according to claim 2, wherein the curing accelerator contains an imidazole-based curing accelerator and / or a thiol-based curing accelerator.
4. The (meth) acrylic resin contains dicyclopentadiene novolac-type epoxy (meth) acrylate, and the sealing agent for liquid crystal dropping method according to claim 1, 2 or 3.
5. 5. The sealing agent for liquid crystal dropping method according to claim 1, 2, 3, or 4, characterized by containing a light shielding agent.
6. A vertical conduction material comprising the sealing agent for a liquid crystal dropping method according to claim 1, and conductive fine particles.
7. A liquid crystal display element manufactured using the sealing agent for a liquid crystal dropping method according to claim 1, 2, 3, 4 or 5, or the vertical conduction material according to claim 6.