JP2013134329A - Sealing agent for liquid crystal display element, vertical conduction material, and liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing agent for a liquid crystal display element that is excellent in adhesive force and in holding power at high temperatures and that hardly causes liquid crystal contamination, and to provide a vertical conduction material and a liquid crystal display element, using the sealing agent for a liquid crystal display element.SOLUTION: A sealing agent for a liquid crystal display element comprises: a block copolymer; a (meth)acrylic acid ester monomer; and a photo-radical polymerization initiator. The block copolymer is an A-B type block copolymer and/or an A-B-A type block copolymer that are composed of a block body A and a block body B.

Description

The present invention relates to a sealant for a liquid crystal display element that has excellent adhesive strength and holding power at high temperatures and hardly causes liquid crystal contamination. Moreover, this invention relates to the vertical conduction material and liquid crystal display element which use this sealing compound for liquid crystal display elements.

In recent years, a method for manufacturing a liquid crystal display device such as a liquid crystal display cell has been disclosed in, for example, Patent Document 1 and Patent Document 2 from a conventional vacuum injection method from the viewpoint of shortening tact time and optimizing the amount of liquid crystal used. A seal comprising a photocurable and heat-curable resin composition containing a photocurable resin such as a (meth) acrylic resin and a photopolymerization initiator, and a thermosetting resin such as an epoxy resin and a thermosetting agent. A liquid crystal dropping method called a dripping method using an agent is being replaced.

In the dripping method using a sealing agent made of a light and heat curable resin composition, first, a seal pattern is formed on one of the two substrates with electrodes. Next, a liquid crystal micro-droplet is dropped into the substrate frame in an uncured state of the sealant, the other substrate is superposed under vacuum, and light is applied to the seal portion to cure the photocurable resin ( Provisional curing step). Then, it heats and thermosetting resin is hardened and a liquid crystal display element is produced.

Conventionally, glass substrates have been mainly used as substrates for liquid crystal display elements, but it has been required to use plastic substrates such as polyethylene terephthalate, polycarbonate, and cycloolefin that are lightweight and inexpensive. In particular, such a flexible substrate made of plastic has attracted attention as a substrate having a shutter function to be disposed in front of a 3D liquid crystal display element. However, such a flexible substrate has a polar surface, whereas the conventional glass substrate has no or almost no polarity, and is flexible, so that it is sufficiently bonded with a conventional sealant. I could not.
Furthermore, it is difficult for conventional sealing agents for liquid crystal display elements to maintain adhesive strength in a wide range from low temperature to high temperature.

JP 2001-133794 A JP-A-5-295087

An object of the present invention is to provide a sealing agent for a liquid crystal display element that is excellent in adhesive strength and holding power at high temperatures and hardly causes liquid crystal contamination. Another object of the present invention is to provide a vertical conduction material and a liquid crystal display element using the sealing agent for a liquid crystal display element.

The present invention contains a block copolymer, a (meth) acrylic acid ester monomer, and a radical photopolymerization initiator, and the block copolymer is composed of a block body A and a block body B, A- It is a sealing agent for liquid crystal display elements which is a B type block copolymer and / or an ABA type block copolymer.
The present invention is described in detail below.

The present inventors use an AB block copolymer and / or an ABBA block copolymer in combination with a (meth) acrylic acid ester monomer, thereby providing an adhesive force and a high temperature. The present inventors have found that a sealing agent for liquid crystal display elements having excellent holding power and hardly causing liquid crystal contamination can be obtained, and the present invention has been completed.
In the present specification, the “holding force” means the ability to maintain adhesiveness.

The sealing agent for liquid crystal display elements of this invention contains a block copolymer.
The block copolymer is an AB type block copolymer and / or an ABA type block copolymer composed of a block body A and a block body B.

The block body A constituting the block copolymer preferably has a glass transition temperature (hereinafter also referred to as “Tg”) of 60 ° C. or higher. When the Tg of the block A is 60 ° C. or higher, the sealing agent for liquid crystal display elements of the present invention has excellent holding power at high temperatures. The minimum with more preferable Tg of the block body A which comprises the said block copolymer is 80 degreeC.
The Tg of the block A is preferably 60 ° C. or higher, but the upper limit is preferably 140 ° C. because of excellent retention at high temperatures for a long time.
In addition, the said glass transition temperature shows the value measured by differential scanning calorimetry (DSC) based on "the plastics transition temperature measuring method" of JISK7121. Specifically, it refers to a value measured with a differential scanning calorimeter at a rate of temperature increase of 10 ° C./min and a measurement temperature of −100 ° C. to 200 ° C. for a 10 mg test piece. As the differential scanning calorimeter, for example, EXSTAR600 (manufactured by Seiko instrument) can be used.

Examples of the block body A include styrene block bodies, (meth) acrylic block bodies, and olefin block bodies. Especially, since manufacture is easy, it is preferable that they are a styrene-type block body or a (meth) acrylic-type block body.
In addition, in this specification, the said (meth) acryl means acryl or methacryl.

As a monomer which comprises the said styrene-type block body, styrene, (alpha) -methylstyrene, p-methylstyrene, t-butylstyrene etc. are mentioned, for example.
Examples of the monomer constituting the (meth) acrylic block body include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, and t-butyl methacrylate. , 2-ethylhexyl methacrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-cyanoethyl methacrylate, phenyl (meth) acrylate, and the like.
Examples of the monomer constituting the olefin block body include ethylene and propylene.

The block body B constituting the block copolymer preferably has a Tg of 10 ° C. or lower. When the Tg of the block B is 10 ° C. or lower, the liquid crystal display element sealing agent of the present invention has sufficient adhesive force even if the substrate is a flexible substrate or the like. The upper limit with more preferable Tg of the block body B which comprises the said block copolymer is -10 degreeC.
The Tg of the block B is preferably 10 ° C. or less, but the preferable lower limit is −80 ° C. because of excellent adhesion to the adherend.

Examples of the block B include (meth) acrylic acid alkyl ester block, conjugated diene such as butadiene and isoprene, and lactone block such as ε-caprolactone and valerolactone. Especially, since it is excellent in the adhesiveness to a to-be-adhered body, it is preferable that it is a (meth) acrylic-acid alkylester block body.

Examples of the monomer constituting the (meth) acrylic acid alkyl ester block body include, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic acid Acrylic acid alkyl esters such as sec-butyl, n-tetradecyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, n-butyl methacrylate, isobutyl methacrylate, amyl methacrylate, isoamyl methacrylate, n methacrylate -Alkyl esters such as hexyl, 2-ethylhexyl methacrylate, pentadecyl methacrylate, lauryl methacrylate, tridecyl methacrylate, 2-hexyldecyl methacrylate, and the like.

The preferable lower limit of the ratio of the block A in the block copolymer is 10% by weight, and the preferable upper limit is 50% by weight. When the proportion of the block A is less than 10% by weight, the obtained sealing agent for liquid crystal display elements may be inferior in holding power. When the ratio of the block A exceeds 50% by weight, the viscosity of the obtained sealing agent for liquid crystal display elements may be too high, resulting in poor applicability. A more preferable lower limit of the proportion of the block A is 15% by weight, and a more preferable upper limit is 30% by weight.
Moreover, the said block copolymer may copolymerize polymerizable components, such as a compound which has unsaturated double bonds other than the block body A and the block body B, in the range which does not impair an effect.

Since the block copolymer can be copolymerized with a (meth) acrylic acid ester monomer, it preferably has terminal activity.
Although the reactivation temperature of the said block copolymer is not specifically limited, A preferable minimum is 45 degreeC and a preferable upper limit is 150 degreeC. When the reactivation temperature of the block copolymer is less than 45 ° C., terminal reactivation may not start. When the reactivation temperature of the block copolymer exceeds 150 ° C., the (meth) acrylic acid ester monomers react with each other, and the block copolymer and the (meth) acrylic acid ester monomer do not copolymerize. There is. A more preferable lower limit of the reactivation temperature of the block copolymer is 80 ° C., and a more preferable upper limit is 130 ° C.

The preferable lower limit of the shear modulus at 25 ° C. of the block copolymer is 1.0 × 10 ⁵ Pa, and the preferable upper limit is 9.0 × 10 ⁶ Pa. When the shear elastic modulus at 25 ° C. of the block copolymer is less than 1.0 × 10 ⁵ Pa, the obtained cured product of the sealant for liquid crystal display elements may be inferior in holding power. When the shear elastic modulus at 25 ° C. of the block copolymer exceeds 9.0 × 10 ⁶ Pa, the viscosity of the sealing agent for liquid crystal display elements is increased and the applicability may be inferior. A more preferable upper limit of the shear elastic modulus at 25 ° C. of the block copolymer is 5.0 × 10 ⁶ Pa.
In the present specification, the shear elastic modulus is -50 ° C. to + 200 ° C. at a frequency of 10 Hz and a heating rate of 6 ° C./min using a dynamic viscoelastic spectrum measuring device such as DVA200 (IT Measurement Control Co., Ltd.). The value obtained by measuring in the range.

The preferable lower limit of the shear modulus at 100 ° C. of the block copolymer is 1.0 × 10 ⁴ Pa, and the preferable upper limit is 9.0 × 10 ⁶ Pa. When the block copolymer has a shear elastic modulus at 100 ° C. of less than 1.0 × 10 ⁴ Pa, the resulting liquid crystal display element sealant may be inferior in the retention of the cured product. When the shear elastic modulus at 100 ° C. of the block copolymer exceeds 9.0 × 10 ⁶ Pa, the adhesive force may be lowered.
A more preferable lower limit of the shear modulus at 100 ° C. of the block copolymer is 3.0 × 10 ⁴ Pa, and a more preferable upper limit is 3.0 × 10 ⁶ Pa.

The minimum with a preferable weight average molecular weight of the said block copolymer is 10,000, and a preferable upper limit is 500,000. When the weight average molecular weight of the block copolymer is less than 10,000, the cured product of the obtained sealing agent for liquid crystal display elements becomes soft and may cause liquid crystal contamination. When the weight average molecular weight of the block copolymer exceeds 500,000, the viscosity of the obtained sealing agent for liquid crystal display elements becomes too high and the coating property may be inferior. The minimum with a more preferable weight average molecular weight of the said block copolymer is 50,000, and a more preferable upper limit is 300,000.
The preferable lower limit of the ratio of the weight average molecular weight to the number average molecular weight of the block copolymer (weight average molecular weight / number average molecular weight) is 1.0, and the preferable upper limit is 3.0. When the weight average molecular weight / number average molecular weight of the block copolymer is less than 1.0, it takes time to produce the block copolymer, and the production efficiency may decrease. If the weight average molecular weight / number average molecular weight of the block copolymer exceeds 3.0, the resulting sealing agent for liquid crystal display elements may be inferior in holding power at high temperatures. The more preferable lower limit of the weight average molecular weight / number average molecular weight of the block copolymer is 1.05, and the more preferable upper limit is 2.5.
In addition, in this specification, the said weight average molecular weight and the said number average molecular weight are the values calculated | required by polystyrene conversion by measuring with gel permeation chromatography (GPC). Examples of the column for measuring the weight average molecular weight and number average molecular weight in terms of polystyrene by GPC include Shodex LF-804 (manufactured by Showa Denko KK).

The minimum with preferable content of the said block copolymer with respect to 100 weight part of sealing compounds for liquid crystal display elements of this invention is 10 weight part, and a preferable upper limit is 70 weight part. If the content of the block copolymer is less than 10 parts by weight, the adhesive strength may be lowered. When the content of the block copolymer exceeds 70 parts by weight, the viscosity of the obtained sealing agent for liquid crystal display elements becomes too high, and the coating property may be inferior. The minimum with more preferable content of the said block copolymer is 20 weight part, and a more preferable upper limit is 60 weight part.

Examples of the method for producing the block copolymer include a method using a living radical polymerization method, an ultraviolet polymerization method, an anionic polymerization method, a cationic polymerization method, a polymerization method using an organic rare earth metal complex, and the like. Of these, a living radical polymerization method using a polymerization initiator having a nitroxide structure is preferable. In the living radical polymerization method using the polymerization initiator having the nitroxide structure, an alkyl radical and nitroxyl are generated by applying heat or the like, and the generated alkyl radical is polymerized in the presence of a monomer or a resin having an unsaturated double bond. Start and let the growth reaction proceed.

In the living radical polymerization method using the polymerization initiator having the nitroxide structure, it is preferable to add an additive within a range that does not impair the adhesive performance of the sealing agent for liquid crystal display elements.
The said additive is not specifically limited, For example, the compound etc. which have unsaturated double bonds, such as a (meth) acrylic acid ester monomer, are mentioned.

Examples of the polymerization initiator having the nitroxide structure include N-tert-butyl-N- (2-methyl-1-phenylpropyl) -O- (1-phenylethyl) hydroxylamine, N-tert-butyl-O. -[1- [4- (Chloromethyl) phenyl] ethyl] -N- (2-methyl-1-phenylpropyl) hydroxylamine, 2,2,5-trimethyl-4-phenyl-3-azahexane-3-nitroxide 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and the like.

The sealing agent for liquid crystal display elements of this invention contains a (meth) acrylic acid ester monomer.
The (meth) acrylic acid ester monomer is preferably a monofunctional (meth) acrylate because it has a small curing shrinkage and can suppress peeling.
In the present specification, the (meth) acrylate means acrylate or methacrylate.

The monofunctional (meth) acrylate is not particularly limited as long as it has one (meth) acryloyloxy group in the molecule. Specifically, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxy Propyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-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, tetrahydride Furfuryl (meth) acrylate, benzyl (meth) acrylate, ethyl carbitol (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, n-butyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhex Ru (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, dimethylaminoethyl (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2 -(Meth) acryloyloxyethyl 2-hydroxypropyl phthalate, glycidyl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate and the like. These monofunctional (meth) acrylates may be used alone or in combination of two or more.

With respect to the content of the monofunctional (meth) acrylate, a preferable lower limit is 30 parts by weight and a preferable upper limit is 90 parts by weight with respect to 100 parts by weight of the sealing agent for liquid crystal display elements of the present invention. If the content of the monofunctional (meth) acrylate is less than 30 parts by weight, the photocuring property cannot be sufficiently imparted to the sealing agent for liquid crystal display elements, and it becomes difficult to achieve both adhesion and flexibility. There is. If the content of the monofunctional (meth) acrylate exceeds 90 parts by weight, the resulting sealing agent for liquid crystal display elements may have a low viscosity and poor applicability. The minimum with more preferable content of the said monofunctional (meth) acrylate is 40 weight part, and a more preferable upper limit is 80 weight part.

The sealing agent for liquid crystal display elements of this invention may contain polyfunctional (meth) acrylate as said (meth) acrylic acid ester monomer for the purpose of improving the heat resistance of hardened | cured material.

Examples of the polyfunctional (meth) acrylate include an ester compound obtained by reacting a compound having a hydroxyl group with (meth) acrylic acid, and an epoxy obtained by reacting (meth) acrylic acid with an epoxy compound ( Examples thereof include urethane (meth) acrylates obtained by reacting (meth) acrylates and isocyanates with (meth) acrylic acid derivatives having a hydroxyl group.
In this specification, the said epoxy (meth) acrylate shows the compound which made all the epoxy groups in an epoxy compound react with (meth) acrylic acid.

Among the ester compounds, examples of the bifunctional compound include 1,4-butanediol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, and 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 ( ) 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 , And polybutadiene diol di (meth) acrylate.

Among the above ester compounds, those having three or more functions include, for example, 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 glycol Sid added glycerin tri (meth) acrylate, tris (meth) acryloyloxyethyl phosphate, and the like.

The epoxy (meth) acrylate is not particularly limited, and examples thereof include those obtained by reacting an epoxy compound and (meth) acrylic acid in the presence of a basic catalyst according to a conventional method.

Examples of the epoxy compound that is a raw material for synthesizing the epoxy (meth) acrylate include, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and 2,2′-diallyl bisphenol A type epoxy resin. , Hydrogenated bisphenol type epoxy resin, propylene oxide added bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, phenol Novolac epoxy resin, orthocresol novolac epoxy resin, dicyclopentadiene novolac epoxy resin, biphenyl novolac epoxy resin, naphtha Ren phenol novolak type epoxy resin, glycidyl amine type epoxy resin, alkyl polyol type epoxy resin, rubber-modified epoxy resins, glycidyl ester compounds.

As what is marketed among the said bisphenol A type epoxy resins, Epicoat 828EL, Epicoat 1004 (all are the Mitsubishi Chemical company make), Epiklon 850-S (made by DIC company), etc. are mentioned, for example.
As what is marketed among the said bisphenol F type epoxy resins, Epicoat 806, Epicoat 4004 (all are Mitsubishi Chemical Corporation make) etc. are mentioned, for example.
As what is marketed among the said bisphenol S-type epoxy resins, Epicron EXA1514 (made by DIC Corporation) etc. are mentioned, for example.
As what is marketed among the said 2,2'- diallyl bisphenol A type epoxy resins, RE-810NM (made by Nippon Kayaku Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said hydrogenated bisphenol type | mold epoxy resins, Epicron EXA7015 (made by DIC Corporation) etc. are mentioned, for example.
As what is marketed among the said propylene oxide addition bisphenol A type epoxy resins, EP-4000S (made by ADEKA) etc. are mentioned, for example.
As what is marketed among the said resorcinol type epoxy resins, EX-201 (made by Nagase ChemteX Corporation) etc. are mentioned, for example.
As what is marketed among the said biphenyl type epoxy resins, Epicoat YX-4000H (made by Mitsubishi Chemical Corporation) etc. are mentioned, for example.
As what is marketed among the said sulfide type epoxy resins, YSLV-50TE (made by Nippon Steel Chemical Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said diphenyl ether type epoxy resins, YSLV-80DE (made by Nippon Steel Chemical Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said dicyclopentadiene type epoxy resins, EP-4088S (made by ADEKA) etc. are mentioned, for example.
As what is marketed among the said naphthalene type | mold epoxy resins, Epicron HP4032, Epicron EXA-4700 (all are the products made from DIC) etc. are mentioned, for example.
As what is marketed among the said phenol novolak-type epoxy resins, Epicron N-770 (made by DIC Corporation) etc. are mentioned, for example.
As what is marketed among the said ortho cresol novolak-type epoxy resins, Epicron N-670-EXP-S (made by DIC) etc. are mentioned, for example.
As what is marketed among the said dicyclopentadiene novolak-type epoxy resins, epiclone HP7200 (made by DIC) etc. are mentioned, for example.
As what is marketed among the said biphenyl novolak-type epoxy resins, NC-3000P (made by Nippon Kayaku Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said naphthalene phenol novolak-type epoxy resins, ESN-165S (made by Nippon Steel Chemical Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said glycidylamine type epoxy resins, Epicoat 630 (made by Mitsubishi Chemical Corporation), Epicron 430 (made by DIC Corporation), TETRAD-X (made by Mitsubishi Gas Chemical Co., Inc.) etc. are mentioned, for example.
Examples of commercially available alkyl polyol type epoxy resins include ZX-1542 (manufactured by Nippon Steel Chemical Co., Ltd.), Epicron 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 (all manufactured by Nippon Steel Chemical Co., Ltd.), Epolide PB (manufactured by Daicel Chemical Industries, Ltd.), and the like.
As what is marketed among the said glycidyl ester compounds, Denacol EX-147 (made by Nagase ChemteX Corporation) etc. is mentioned, for example.
Other commercially available epoxy resins include, for example, YDC-1312, YSLV-80XY, YSLV-90CR (all manufactured by Nippon Steel Chemical Co., Ltd.), XAC4151 (manufactured by Asahi Kasei Co., Ltd.), Epicoat 1031, and Epicoat. 1032 (all manufactured by Mitsubishi Chemical Corporation), EXA-7120 (manufactured by DIC Corporation), TEPIC (manufactured by Nissan Chemical Industries, Ltd.) and the like.

Specifically, the epoxy (meth) acrylate is, for example, 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 as a reaction catalyst. 2 parts by weight of triethylamine and 210 parts by weight of acrylic acid can be obtained by stirring at 90 ° C. while feeding air and reacting for 5 hours.

Examples of commercially available epoxy (meth) acrylates include EBECRYL860, EBECRYL3200, EBECRYL3201, EBECRYL3412, EBECRYL3600, EBECRYL3700, EBECRYL3701, EBECRYL3702, EBECRYL3703, 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 200 PA, epoxy ester 80 MFA, Poxy 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, Denacol acrylate DA-911 (all manufactured by Nagase ChemteX Corporation) and the like.

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

The isocyanate used as the raw material of the urethane (meth) acrylate is not particularly limited. For example, 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, triphenylmethanetri Isocyanate, tris (isocyanatephenyl) thiophosphate, tetramethylxylene diisocyanate, 1,6,10-undecane triiso Aneto and the like. In addition, for example, chain extension obtained by reaction of polyol such as ethylene glycol, glycerin, sorbitol, trimethylolpropane, (poly) propylene glycol, carbonate diol, polyether diol, polyester diol, polycaprolactone diol and excess isocyanate. Diisocyanate compounds can also be used.

The (meth) acrylic acid derivative having a hydroxyl group, which is a raw material for the urethane (meth) acrylate, is not particularly limited. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl Commercial products such as (meth) acrylate and 2-hydroxybutyl (meth) acrylate, and two products such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol Mono (meth) acrylates of monohydric alcohols, mono (meth) acrylates or di (meth) acrylates of trivalent alcohols such as trimethylolethane, trimethylolpropane and glycerin, and epoxies such as bisphenol A type epoxy (meth) acrylate ( Data) acrylate, and the like.

Specifically, the urethane (meth) acrylate includes, 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. The mixture can be reacted at 60 ° C. for 2 hours with stirring under reflux, then 51 parts by weight of 2-hydroxyethyl acrylate is added, and the mixture is refluxed and stirred at 90 ° C. while feeding air for 2 hours.

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 U -1255, Art Resin UN-330, Art Resin UN-3320HB, Art Resin UN-1200TPK, Art Resin SH-500B (all manufactured by Negami Kogyo Co., Ltd.), U-2HA, U-2PHA, U-3HA, U-4HA U-6H, U-6LPA, U-6HA, U-10H, U-15HA, U-122A, U-122P, U-108, U-108A, U-324A, U-340A, U-340P, U -1084A, U-2061BA, UA-340P, UA-4100, UA-4000, UA-4200, UA-4400, UA-5201P, UA-7100, UA-7200, UA-W2A (all Shin-Nakamura Chemical Co., Ltd. Manufactured), AI-600, AH-600, AT-600, UA-101I, UA-101T, UA-306H, U -306I, UA-306T (all manufactured by Kyoeisha Chemical Co., Ltd.).

The content of the polyfunctional (meth) acrylate is preferably 0.01 parts by weight and preferably 5 parts by weight with respect to 100 parts by weight of the sealing agent for liquid crystal display elements of the present invention. When the content of the polyfunctional (meth) acrylate is less than 0.01 parts by weight, effects such as improvement of heat resistance by blending the polyfunctional (meth) acrylate may not be sufficiently exhibited. When content of the said polyfunctional (meth) acrylate exceeds 5 weight part, the sealing compound for liquid crystal display elements obtained may become inferior to the adhesiveness with respect to a flexible substrate. The minimum with more preferable content of the said polyfunctional (meth) acrylate is 0.05 weight part, and a more preferable upper limit is 2 weight part.

The sealing agent for liquid crystal display elements of the present invention may be blended with a resin having an epoxy group within the range not impairing the object of the present invention for the purpose of improving the adhesion to the substrate.

Examples of the resin having an epoxy group include the same epoxy compounds as the raw material for synthesizing the above-described epoxy (meth) acrylate.

Moreover, you may contain resin which has an epoxy group and a (meth) acryloyloxy group in 1 molecule as resin which has the said epoxy group. 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 can be obtained, for example, by reacting an epoxy resin and (meth) acrylic acid in the presence of a basic catalyst according to a conventional method. Specifically, for example, 190 g of phenol novolac type epoxy resin N-770 (manufactured by DIC) is dissolved in 500 mL of toluene, 0.1 g of triphenylphosphine is added to this solution to obtain a uniform solution, and 35 g of acrylic acid is added to this solution. Was added dropwise under reflux stirring for 2 hours, and further reflux stirring was performed for 6 hours. Next, by removing toluene, a partially acrylic modified phenol novolac type epoxy resin in which 50 mol% of the epoxy groups reacted with acrylic acid was obtained. Can be obtained (in this case 50% partially acrylic modified).

Examples of commercially available partial (meth) acrylic-modified epoxy resins include UVACURE 1561 (manufactured by Daicel Cytec Co., Ltd.).

With respect to the content of the resin having an epoxy group, a preferable lower limit is 1 part by weight and a preferable upper limit is 30 parts by weight with respect to 100 parts by weight of the sealing agent for liquid crystal display elements of the present invention. If the content of the resin having an epoxy group is less than 1 part by weight, effects such as improvement in adhesiveness by blending a resin having an epoxy group may not be sufficiently exhibited. When the content of the resin having an epoxy group exceeds 30 parts by weight, the obtained sealing agent for liquid crystal display elements may contaminate the liquid crystal. The minimum with more preferable content of the resin which has the said epoxy group is 5 weight part, and a more preferable upper limit is 20 weight part.

The sealing agent for liquid crystal display elements of this invention contains radical photopolymerization initiator.
The photo-radical polymerization initiator can be sensitized by irradiation with light in a wavelength region of 370 to 450 nm, and particularly has an extinction coefficient at 350 nm measured in acetonitrile of 100 to 100,000 M ⁻¹ · cm. What is ^-1 is preferable. However, since the flexible substrate used may absorb a specific wavelength, it may be sensitive to light having a wavelength of less than 370 nm or light having a wavelength of more than 450 nm.

Among the above radical photopolymerization initiators, those commercially available include, for example, IRGACURE127, IRGACURE184, IRGACURE369, IRGACURE02, IRGACURE651, IRGACURE651, IRGACURE907, IRGACURE907, IRGACURE1700, IRGACURE1700, IRGACURE1700, IRGACURE1700, IRGACURE1700, IRGACURE1700. , CGI242, LUCIRIN TPO, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether (all manufactured by BASF Japan), ESACURE TPO (Lambert) SPEEDCURE TPO, SPEEDCURE TPO-L (all manufactured by LAMBSON), MICURE TPO (manufactured by MIWON), N-1414 (manufactured by ADEKA), Sorbastron BIPE, Sorbastron BIBE, biimidazole (manufactured by Kurokin Kasei) , KAYACURE BP, KAYACURE DETX-S (all manufactured by Nippon Kayaku Co., Ltd.), ESACURE KIP 150 (manufactured by Lamberti), S-121 (manufactured by Shinko Giken Co., Ltd.), SEIKORU BEE (manufactured by Seiko Chemical Co., Ltd.), KR-02 ( Light chemicals).

The content of the photo radical polymerization initiator is preferably 0.1 parts by weight and preferably 10 parts by weight with respect to 100 parts by weight of the sealing agent for liquid crystal display elements of the present invention. If the content of the radical photopolymerization initiator is less than 0.1 parts by weight, the photopolymerization may not proceed sufficiently or the reaction may become too slow. When the content of the radical photopolymerization initiator exceeds 10 parts by weight, workability may be deteriorated or the reaction may become uneven. The minimum with more preferable content of the said radical photopolymerization initiator is 0.5 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 further contain a thermal radical polymerization initiator.
Examples of the thermal radical polymerization initiator include peroxides, azo compounds, and the like. Examples of commercially available products include perbutyl O, perhexyl O, perbutyl PV (all manufactured by NOF Corporation), V -30, V-501, V-601, VPE-0201, VPE-0401, VPE-0601 (all manufactured by Wako Pure Chemical Industries, Ltd.) and the like.

Although content of the said thermal radical polymerization initiator is not specifically limited, A preferable minimum is 0.1 weight part and a preferable upper limit is 30 weight part with respect to 100 weight part of sealing compounds for liquid crystal display elements of this invention. When the content of the thermal radical polymerization initiator is less than 0.1 parts by weight, the obtained sealing agent for liquid crystal display elements may not be sufficiently cured. When content of the said thermal radical polymerization initiator exceeds 30 weight part, the viscosity of the sealing agent for liquid crystal display elements obtained will become high, and applicability | paintability may worsen. The minimum with more preferable content of the said thermal radical polymerization initiator is 0.5 weight part, and a more preferable upper limit is 10 weight part.

When the said curable resin contains the resin which has the said epoxy group, it is preferable that the sealing compound for liquid crystal display elements of this invention contains a thermosetting agent.

Examples of the thermosetting agent include organic acid hydrazides, imidazole derivatives, amine compounds, polyhydric phenol compounds, acid anhydrides, and the like. Of these, organic acid hydrazide is preferably used.

The organic acid hydrazide is not particularly limited, and examples thereof include sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, malonic acid dihydrazide, and the like. Examples of commercially available products include SDH (manufactured by Nippon Finechem), 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 can be mentioned.

Although content of the said thermosetting agent is not specifically limited, A preferable minimum is 1 weight part and a preferable upper limit is 50 weight part with respect to 100 weight part of resin which has the said epoxy group. When the content of the thermosetting agent is less than 1 part by weight, the obtained sealing agent for liquid crystal display elements 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 display elements obtained will become high, and applicability | paintability may worsen. The upper limit with more preferable content of the said thermosetting agent is 30 weight part.

The sealing agent for liquid crystal display elements of the present invention may contain a filler for the purpose of improving the viscosity, improving the adhesion due to the stress dispersion effect, improving the linear expansion coefficient, and further improving the moisture resistance of the cured product. preferable.

The filler is not particularly limited. For example, talc, asbestos, silica, diatomaceous earth, smectite, bentonite, calcium carbonate, magnesium carbonate, alumina, montmorillonite, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, hydroxide Inorganic fillers such as magnesium, aluminum hydroxide, glass beads, silicon nitride, barium sulfate, gypsum, calcium silicate, sericite activated clay, aluminum nitride, polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, acrylic polymer fine particles, etc. Of organic fillers.

The content of the filler is preferably 10 parts by weight and preferably 70 parts by weight with respect to 100 parts by weight of the sealant for liquid crystal display elements of the present invention. When the content of the filler is less than 10 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 display elements obtained will become high, and applicability | paintability may worsen. 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 has sufficient adhesiveness to a flexible substrate without blending a silane coupling agent, but contains a silane coupling agent when further improvement in adhesion is required. It is preferable. 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, γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and the like are preferably used.

The content of the silane coupling agent is preferably 0.1 parts by weight and preferably 20 parts by weight with respect to 100 parts by weight of the sealing agent for liquid crystal display elements of the present invention. 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 display elements obtained may contaminate a liquid crystal. 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 method for producing the sealant for liquid crystal display elements of the present invention is not particularly limited. For example, a block copolymer using a mixer such as a homodisper, a homomixer, a universal mixer, a planetarium mixer, a kneader, or a three roll. And a method of mixing a (meth) acrylic acid ester monomer, a radical photopolymerization initiator, a silane coupling agent added as necessary, and the like.

In the sealing agent for liquid crystal display elements of the present invention, the preferred lower limit of the viscosity measured at 25 ° C. and 1 rpm using an E-type viscometer is 50,000 Pa · s, and the preferred upper limit is 500,000 Pa · s. When the viscosity is less than 50,000 Pa · s or exceeds 500,000 Pa · s, workability when applying the liquid crystal display element sealing agent to the substrate may be deteriorated. A more preferable upper limit of the viscosity is 400,000 Pa · s.

In order to suppress liquid crystal contamination, the smaller the amount of the water-soluble ionic substance contained in the sealant for a liquid crystal display element of the present invention is better. Specifically, the preferable upper limit of the ionic conductivity in the sealant for liquid crystal display elements of the present invention is 50 μS / cm. If the ionic conductivity exceeds 50 μS / cm, the liquid crystal may be contaminated by the migration of free ions in the sealant to the liquid crystal. A more preferable upper limit of the ionic conductivity is 30 μS / cm.
In the present specification, the ionic conductivity can be measured by, for example, a conductivity meter manufactured by Horiba, Ltd.

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

The conductive fine particles are not particularly limited, and metal balls, those obtained by forming a conductive metal layer on the surface of resin fine particles, and 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 which uses the sealing compound for liquid crystal display elements of this invention and / or the vertical conduction material of this invention is also one of this invention.

As a method for producing the liquid crystal display element of the present invention, for example, screen printing of the sealant for the liquid crystal display element of the present invention on a transparent substrate such as a glass substrate with two electrodes such as an ITO thin film or a polyethylene terephthalate substrate, A step of forming a rectangular seal pattern by applying a dispenser, etc., a liquid crystal display element sealant of the present invention is uncured, and liquid crystal microdrops are dropped onto the entire surface of the transparent substrate, and immediately separated. The step of superimposing the substrates, the step of irradiating the seal pattern portion of the sealant for the liquid crystal display element of the present invention with light such as ultraviolet rays to temporarily cure the sealant, and heating the temporarily cured sealant And a method having a step of main curing.

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal display elements which is excellent in adhesive force and the retention strength in high temperature, and hardly causes liquid-crystal contamination can be provided. Moreover, according to this invention, the vertical conduction material and liquid crystal display element which use this sealing compound for liquid crystal display elements can be provided.

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

Example 1
(Preparation of sealing agent for liquid crystal display elements)
MMA-BA-MMA block copolymer (A) (manufactured by Kuraray, “LA2250”), phenoxydiethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., “light acrylate P2H-A”), according to the blending ratio described in Table 1. And after mixing silica (manufactured by Admatechs, “Admafine SO-C2”), a photo radical polymerization initiator (manufactured by BASF Japan, “IRGACURE651”) was blended. After the radical photopolymerization initiator was completely dissolved, the mixture was stirred using a planetary stirrer (manufactured by Shinky Corporation, “Awatori Netaro”). Then, the sealing compound for liquid crystal display elements was prepared by disperse | distributing uniformly using 3 rolls.
The MMA-BA-MMA block copolymer (A) used was composed of 30% by weight of methyl methacrylate having a glass transition temperature of 110 ° C. (block A) and butyl acrylate having a glass transition temperature of −30 ° C. A B-A-A type MMA-BA-MMA block copolymer (both ends inactive) composed of 70% by weight of block body B). The weight average molecular weight of the MMA-BA-MMA block copolymer (A) was 68,000, and the weight average molecular weight / number average molecular weight was 1.2.
Moreover, the shear elastic modulus in 25 degreeC of the MMA-BA-MMA block copolymer (A) was 5.3 * 10 < ⁵ > Pa, and the shear elastic modulus in 100 degreeC was 2.0 * 10 < ⁵ > Pa.

(Example 2)
(Synthesis of polymerization initiator (a))
In a 100 mL round bottom flask substituted with nitrogen, 29.9 g of N-tert-butyl-N- (2-methyl-1-phenylpropyl) [(1-phenylethyl) hydroxylamine] ether (manufactured by Aldrich) (2.1 equivalent), 10 g (1 equivalent) of hexanediol diacrylate (Aldrich) and 100 g of ethanol were supplied to obtain a mixture. The obtained mixture was heated to reflux for 8 hours, and then ethanol was removed under reduced pressure to obtain 39 g of a yellow polymerization initiator (a) having a high viscosity.

(Preparation of MMA-BA-MMA block copolymer (B))
1000 parts by weight of n-butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.) is supplied as a monomer component to a 2 L separable flask equipped with a stirrer, a cooler, a thermometer, and a nitrogen gas inlet, and nitrogen gas is used. After removing dissolved oxygen in n-butyl acrylate by bubbling for 30 minutes, the inside of the separable flask was replaced with nitrogen gas, and heated with stirring in an oil bath until n-butyl acrylate reached 50 ° C. did.
When n-butyl acrylate reaches 50 ° C., 5 parts by weight of polymerization initiator (a) is added and heated at 1 ° C./min until it reaches 115 ° C., and polymerization is advanced for 420 minutes while maintaining at 115 ° C. Then, unreacted n-butyl acrylate was removed by drying under reduced pressure. As a result, an acrylic polymer having a weight average molecular weight of 130,000 and a weight average molecular weight / number average molecular weight of 1.5 was obtained. In a 500 mL round bottom separable flask equipped with a stirrer, a cooler, a thermometer, and a nitrogen gas inlet, 100 parts by weight of the obtained acrylic polymer, 50 parts by weight of toluene (manufactured by Gordo Solvents), methyl methacrylate ( (Mitsubishi Rayon Co., Ltd.) Supplying a mixture containing 45 parts by weight, replacing the inside of the separable flask with nitrogen gas for 30 minutes, and heating the mixture at 5 ° C / min until 115 ° C in an oil bath while stirring. did. After proceeding solution polymerization for 420 minutes while maintaining the temperature of the mixture at 115 ° C., unreacted monomers and toluene were removed by drying under reduced pressure.
As a result, AB composed of 24% by weight of methyl methacrylate (block A) having a glass transition temperature of 110 ° C. and 76% by weight of butyl acrylate (block B) having a glass transition temperature of −30 ° C. -A type MMA-BA-MMA block copolymer (B) (both ends inactive) was obtained. The obtained MMA-BA-MMA block copolymer (B) had a weight average molecular weight of 170,000 and a weight average molecular weight / number average molecular weight of 1.9.
The obtained MMA-BA-MMA block copolymer (B) had a shear elastic modulus at 25 ° C. of 3.3 × 10 ⁵ Pa and a shear elastic modulus at 100 ° C. of 1.5 × 10 ⁵ Pa. .

(Preparation of sealing agent for liquid crystal display elements)
According to the blending ratio described in Table 1, the obtained MMA-BA-MMA block copolymer (B), phenoxydiethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light acrylate P2H-A”), and silica (ADMATEX) After the compounding of “Admafine SO-C2”, a photo radical polymerization initiator (“IRGACURE651” manufactured by BASF Japan) was blended. After the radical photopolymerization initiator was completely dissolved, the mixture was stirred using a planetary stirrer (manufactured by Shinky Corporation, “Awatori Netaro”). Then, the sealing compound for liquid crystal display elements was prepared by disperse | distributing uniformly using 3 rolls.

(Example 3)
(Preparation of sealing agent for liquid crystal display elements)
According to the compounding ratio described in Table 1, St-BA-St block copolymer (manufactured by Arkema, “SS8590”), phenoxydiethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., “light acrylate P2H-A”), silica (ad Photoradical polymerization was started after blending MATEX, "Admafine SO-C2"), and γ-glycidoxypropyltrimethoxysilane (Shin-Etsu Silicone, "KBM-403") as a silane coupling agent. An agent (“IRGACURE651” manufactured by BASF Japan) was blended. After the radical photopolymerization initiator was completely dissolved, the mixture was stirred using a planetary stirrer (manufactured by Shinky Corporation, “Awatori Netaro”). Then, the sealing compound for liquid crystal display elements was prepared by disperse | distributing uniformly using 3 rolls.
The St-BA-St block copolymer used was 15% by weight of styrene (block body A) having a glass transition temperature of 100 ° C. and butyl acrylate (block body B) 85 having a glass transition temperature of −30 ° C. It is an ABA type St-BA-St block copolymer (both terminal activity) comprised by weight%. The weight average molecular weight of the St-BA-St block copolymer was 240,000, and the weight average molecular weight / number average molecular weight was 1.45.
Further, the St-BA-St block copolymer had a shear elastic modulus at 25 ° C. of 2.5 × 10 ⁵ Pa and a shear elastic modulus at 100 ° C. of 3.0 × 10 ⁴ Pa.

Example 4
(Production of BA-St-BA block copolymer)
In a 2 L separable flask equipped with a stirrer, a cooler, a thermometer and a nitrogen gas inlet, 1000 parts by weight of styrene (manufactured by Wako Pure Chemical Industries) as a monomer component, 500 parts by weight of toluene (manufactured by Gordo Solvents) After removing dissolved oxygen in the styrene solution by bubbling with nitrogen gas for 30 minutes, the inside of the separable flask was replaced with nitrogen gas, and the styrene solution was heated to 50 ° C. in an oil bath while stirring. Heated until. When the styrene solution reached 50 ° C., 9.5 parts by weight of the polymerization initiator (a) obtained in the same manner as in Example 2 was added and heated at 115 ° C. at 1 ° C./min until 115 ° C. was reached. The polymerization was allowed to proceed for 420 minutes while maintaining the temperature, and then unreacted styrene and toluene were removed by drying under reduced pressure. As a result, a styrene polymer having a weight average molecular weight of 70,000 and a weight average molecular weight / number average molecular weight of 1.2 was obtained. In a 500 mL round bottom separable flask equipped with a stirrer, cooler, thermometer and nitrogen gas inlet, 100 parts by weight of the obtained styrene polymer, 50 parts by weight of toluene (manufactured by Gordo Solvents), butyl acrylate (Japan) (Catalyst Co., Ltd.) Supplying a mixed solution containing 45 parts by weight, replacing the inside of the separable flask with nitrogen gas for 30 minutes, and heating at 5 ° C./min until the mixed solution reached 115 ° C. with stirring in an oil bath . After proceeding solution polymerization for 420 minutes while maintaining the temperature of the mixture at 115 ° C., unreacted monomers and toluene were removed by drying under reduced pressure.
As a result, A-B-A composed of 24% by weight of butyl acrylate (block A) having a glass transition temperature of −30 ° C. and 76% by weight of styrene (block B) having a glass transition temperature of 100 ° C. A type of BA-St-BA block copolymer (both end activity) was obtained. The obtained BA-St-BA block copolymer had a weight average molecular weight of 90,000 and a weight average molecular weight / number average molecular weight of 1.4.
Further, the obtained BA-St-BA block copolymer had a shear elastic modulus at 25 ° C. of 2.1 × 10 ⁵ Pa and a shear elastic modulus at 100 ° C. of 9.0 × 10 ³ Pa.

(Preparation of sealing agent for liquid crystal display elements)
According to the blending ratio described in Table 1, the obtained BA-St-BA block copolymer, phenoxydiethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., “Light acrylate P2H-A”), and silica (manufactured by Admatechs, After blending “Admafine SO-C2”), a radical photopolymerization initiator (“IRGACURE651” manufactured by BASF Japan) was blended. After the radical photopolymerization initiator was completely dissolved, the mixture was stirred using a planetary stirrer (manufactured by Shinky Corporation, “Awatori Netaro”). Then, the sealing compound for liquid crystal display elements was prepared by disperse | distributing uniformly using 3 rolls.

(Example 5)
(Production of IBMA-BA-IBMA block copolymer)
In a 500 mL round bottom separable flask equipped with a stirrer, a cooler, a thermometer, and a nitrogen gas inlet, 100 parts by weight of an acrylic polymer obtained in the same manner as in Example 2, 50 parts by weight of toluene (Gordo Solvent Co., Ltd.) And a mixed solution containing 45 parts by weight of isobutyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light Ester IB”), the inside of the separable flask is replaced with nitrogen gas for 30 minutes, and the mixed solution is stirred. It heated at 5 degree-C / min until the liquid mixture became 115 degreeC with the oil bath. After proceeding solution polymerization for 420 minutes while maintaining the temperature of the mixed solution at 115 ° C., unreacted monomers and toluene were removed by drying under reduced pressure.
As a result, AB composed of 24% by weight of isobutyl methacrylate (block A) having a glass transition temperature of 45 ° C. and 76% by weight of butyl acrylate (block B) having a glass transition temperature of −30 ° C. -A-type IBMA-BA-IBMA block copolymer (both terminal activities) was obtained. The obtained IBMA-BA-IBMA block copolymer had a weight average molecular weight of 170,000 and a weight average molecular weight / number average molecular weight of 1.9.
The obtained IBMA-BA-IBMA block copolymer had a shear elastic modulus at 25 ° C. of 1.5 × 10 ⁵ Pa and a shear elastic modulus at 100 ° C. of 3.0 × 10 ³ Pa.

(Preparation of sealing agent for liquid crystal display elements)
According to the blending ratio described in Table 1, the obtained IBMA-BA-IBMA block copolymer, phenoxydiethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., “Light acrylate P2H-A”), and silica (manufactured by Admatechs, After blending “Admafine SO-C2”), a radical photopolymerization initiator (“IRGACURE651” manufactured by BASF Japan) was blended. After the radical photopolymerization initiator was completely dissolved, the mixture was stirred using a planetary stirrer (manufactured by Shinky Corporation, “Awatori Netaro”). Then, the sealing compound for liquid crystal display elements was prepared by disperse | distributing uniformly using 3 rolls.

(Comparative Example 1)
(Preparation of sealing agent for liquid crystal display elements)
According to the compounding ratio described in Table 1, polyester (Toyobo Co., Ltd., “Byron 500”, both terminal inactive), phenoxydiethylene glycol acrylate (Kyoeisha Chemical Co., Ltd., “Light acrylate P2H-A”), and silica (Ad After mixing with “Matrix,“ Admafine SO-C2 ”), a radical photopolymerization initiator (“ BAGACURE651 ”manufactured by BASF Japan) was added. After the radical photopolymerization initiator was completely dissolved, the mixture was stirred using a planetary stirrer (manufactured by Shinky Corporation, “Awatori Netaro”). Then, the sealing compound for liquid crystal display elements was prepared by disperse | distributing uniformly using 3 rolls.

(Comparative Example 2)
(Preparation of sealing agent for liquid crystal display elements)
According to the blending ratio described in Table 1, after blending polyester (Toyobo Co., Ltd., “Byron 500”, both ends inactive) and silica (Admatechs Co., Ltd., “Admafine SO-C2”), light A radical polymerization initiator (manufactured by BASF Japan, “IRGACURE651”) was blended. Stirring was performed using a planetary stirrer (Shinky Corporation, “Awatori Nertaro”). Thereafter, a liquid crystal display element sealant was prepared by uniformly dispersing using three rolls. However, it became high viscosity and could not be applied to the adherend.

<Evaluation>
The following evaluation was performed about the sealing compound for liquid crystal display elements obtained by the Example and the comparative example. The results are shown in Table 1.

(Adhesiveness to flexible substrate)
The obtained sealing agent for liquid crystal display elements is taken in the center of a polyethylene terephthalate (PET) film (Lintec Co., “PET5011”) of 20 mm × 50 mm, and PET 5011 of the same size is superimposed thereon. The sealing agent for liquid crystal display elements was expanded. In that state, 100 mW / cm ² of ultraviolet rays were irradiated for 30 seconds to cure the sealant, and an adhesion test piece was obtained. The adhesive strength of the obtained adhesion test piece was measured using EZgraph (manufactured by Shimadzu Corporation). The adhesive strength with respect to the flexible substrate was evaluated as “◯” when the adhesive strength was 1.0 N / cm or more and “X” when the adhesive strength was less than 1.0 N / cm.

(Holding power)
In accordance with JIS Z0237, the obtained liquid crystal display element sealant is applied to a stainless steel (SUS304) plate polished with No. 280 sandpaper so that the adhesion area is 25 mm × 25 mm and the thickness is 10 μm. Then, a polyethylene terephthalate (PET) film (“PET5011” manufactured by Lintec Corporation) was overlaid thereon. In that state, 100 mW / cm ² of ultraviolet rays were irradiated for 30 seconds to cure the sealant, and a test piece for measuring holding force was obtained. Leave in an atmosphere of 80 ° C for 30 minutes, apply a load of 100 g or 1 kg to one end of the test piece, install a stainless steel plate so that a force is applied in the shear direction to the bonding surface, and the test piece peels off. The time to fall was measured.

(Liquid crystal contamination (liquid crystal specific resistance retention rate))
Into a sample bottle, 1.0 g of liquid crystal (manufactured by Chisso Corporation, “JC-5001LA”) was added, 0.02 g of the obtained liquid crystal display element sealing agent was added and shaken, and then heated at 120 ° C. for 1 hour. The temperature was returned to room temperature (25 ° C.), and the liquid crystal part was measured using a liquid crystal resistivity measuring device (manufactured by KEITHLEY Instruments, “6517A”), and an electrode for liquid (“LE-21” manufactured by Ando Electric Co., Ltd.) as an electrode. The liquid crystal specific resistance retention was measured in a standard temperature and humidity state (20 ° C., 65% RH). The liquid crystal stain resistance was evaluated with “○” when the liquid crystal resistivity holding ratio exceeded 0.1 and “×” when the liquid crystal specific resistance retention ratio was 0.1 or less.
In addition, the liquid crystal specific resistance retention was calculated | required by the following formula.
Liquid crystal specific resistance retention ratio (%) = (use liquid crystal specific resistance after addition of sealant / use liquid crystal specific resistance without addition of sealant) × 100

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal display elements which is excellent in adhesive force and the retention strength in high temperature, and hardly causes liquid-crystal contamination can be provided. Moreover, according to this invention, the vertical conduction material and liquid crystal display element which use this sealing compound for liquid crystal display elements can be provided.

Claims (7)

Containing a block copolymer, a (meth) acrylic acid ester monomer, and a radical photopolymerization initiator,
The block copolymer is an AB type block copolymer and / or an ABA type block copolymer composed of a block body A and a block body B, and a liquid crystal display Seal for element. The block A is a styrene block having a glass transition temperature of 60 ° C. or higher or a (meth) acrylic block having a glass transition temperature of 60 ° C. or higher.
Block B is a (meth) acrylic acid alkyl ester block having a glass transition temperature of 10 ° C. or lower,
The block copolymer has a shear modulus at 25 ° C. of 1.0 × 10 ^{5 to} 9.0 × 10 ⁶ Pa and a shear modulus of elasticity at 100 ° C. of 1.0 × 10 ^{4 to} 9.0 × 10 ⁶ Pa. The sealing agent for liquid crystal display elements according to claim 1, wherein: 3. The seal for a liquid crystal display element according to claim 1, wherein the block copolymer has a weight average molecular weight of 10,000 to 500,000 and a weight average molecular weight / number average molecular weight of 1.0 to 3.0. Agent. The content of the block copolymer with respect to 100 parts by weight of the sealing agent for liquid crystal display elements is 10 to 70 parts by weight,
4. The sealant for a liquid crystal display element according to claim 1, wherein the ratio of the block A in the block copolymer is 10 to 50% by weight. 5. The sealant for a liquid crystal display element according to claim 1, wherein the block copolymer is produced by a living radical polymerization method using a polymerization initiator having a nitroxide structure. A vertical conducting material comprising the sealing agent for a liquid crystal display element according to claim 1, 2, 3, 4 or 5, and conductive fine particles. A liquid crystal display element comprising the sealant for a liquid crystal display element according to claim 1, 2, 3, 4 or 5, and / or the vertical conduction material according to claim 6.