TWI719201B - Sealant for liquid crystal display element, vertical conduction material, and liquid crystal display element - Google Patents

Abstract

The object of the present invention is to provide a sealing compound for liquid crystal display elements which has excellent storage stability and can suppress insertion of liquid crystal into the sealing compound or liquid crystal contamination caused by the sealing compound. In addition, an object of the present invention is to provide an upper and lower conduction material and a liquid crystal display element manufactured using this sealant for liquid crystal display elements.

The sealing compound for liquid crystal display elements of the present invention contains a curable resin, a thermal radical polymerization initiator, and a polymerization inhibitor, and the thermal radical polymerization initiator is an azo compound having a 10-hour half-life temperature of 65°C or less, The above-mentioned polymerization inhibitor is a compound having a naphthalene skeleton or an anthracene skeleton.

Description

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

The present invention relates to a sealing compound for a liquid crystal display element which is excellent in storage stability and can suppress insertion of liquid crystal into a sealing compound or liquid crystal contamination caused by the sealing compound. In addition, the present invention relates to an upper and lower conduction material and a liquid crystal display element manufactured using the sealant for liquid crystal display elements.

In recent years, as a method of manufacturing liquid crystal display elements such as liquid crystal display units, from the viewpoints of shortening the process time and optimizing the amount of liquid crystal used, the use of curable resins as disclosed in Patent Document 1 and Patent Document 2 has been adopted. The combination of photopolymerization initiator and thermal curing agent with light and heat curing type sealant is called the liquid crystal dropping method of the dropping method.

Regarding the dripping method, first, a rectangular sealing pattern is formed by dripping on one of the two substrates with electrodes. Then, in a state where the sealant is not hardened, droplets of liquid crystal are dropped into the sealing frame of the substrate, overlap with another substrate under vacuum, and the sealing part is irradiated with light such as ultraviolet rays to temporarily harden. After that, it is heated and hardened to produce a liquid crystal display element. At present, this dropping method has become the mainstream of the manufacturing method of liquid crystal display elements.

In addition, in the modernization of mobile devices with LCD panels such as mobile phones and portable game consoles, miniaturization of the devices is the most demanding issue. As a way to miniaturize the machine The method includes narrowing the edge of the liquid crystal display portion, for example, arranging the position of the sealing portion under the black matrix (hereinafter, also referred to as narrow-edge design).

However, since the narrow-edge design places the sealant directly under the black matrix, if the dripping method is performed, the light irradiated when the sealant is hardened by light will be shielded, and it is difficult for the light to reach the inside of the sealant. Use conventional sealing Hardening becomes insufficient during the treatment. In this way, if the curing of the sealant becomes insufficient, the uncured sealant component is eluted into the liquid crystal, and there is a problem that liquid crystal contamination is likely to occur.

Therefore, although studies have been conducted on the case where the sealant is hardened only by heat, when it is not temporarily hardened by photopolymerization, the liquid crystal flows during heating and is inserted into the sealant part during the hardening process. The seal pattern is damaged, or the sealant whose viscosity decreases due to heating, contaminates the liquid crystal.

Especially in recent years, with the narrowing of the edges of the panel, the width of the dripped sealant has also become thinner, and the sealing cross-sectional area after lamination has become smaller. Therefore, damage to the seal pattern is likely to occur.

In addition, in recent years, from the viewpoint of energy saving and liquid crystal stability, it has been desired to heat the sealant at a low temperature and for a short time to thermally harden the sealant. As a method for hardening the sealant by heating at a low temperature and for a short time, it can be considered to use a polymerization initiator or a thermosetting agent that has excellent reactivity at low temperatures. However, if such a polymerization initiator or thermosetting agent is used , There is a problem that the sealant becomes poor in storage stability.

[Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Publication No. 2001-133794

Patent Document 2: International Publication No. 02/092718

The object of the present invention is to provide a sealing compound for liquid crystal display elements which has excellent storage stability and can suppress insertion of liquid crystal into the sealing compound or liquid crystal contamination caused by the sealing compound. In addition, an object of the present invention is to provide an upper and lower conduction material and a liquid crystal display element manufactured using this sealant for liquid crystal display elements.

The sealing compound for liquid crystal display elements of the present invention contains a curable resin, a thermal radical polymerization initiator, and a polymerization inhibitor, and the thermal radical polymerization initiator is an azo compound having a 10-hour half-life temperature of 65°C or less, The above-mentioned polymerization inhibitor is a compound having a naphthalene skeleton or an anthracene skeleton.

Hereinafter, the present invention will be described in detail.

The inventors found that by combining an azo compound with a 10-hour half-life temperature below a specific temperature as a thermal radical polymerization initiator and a polymerization inhibitor with a specific structure, it is possible to obtain curability and storage at low temperatures. The sealing compound for liquid crystal display elements which is excellent in both stability, and completed this invention. In addition, when a polymerization initiator with excellent reactivity is used, when the substrate is bonded under reduced pressure in the manufacturing step of the liquid crystal display element, the curing of the sealant proceeds too quickly, resulting in a decrease in adhesiveness It is a problem, but the sealing compound for liquid crystal display elements of this invention can also prevent deterioration of adhesiveness at the time of performing such a board|substrate bonding.

The sealing compound for liquid crystal display elements of this invention contains a thermal radical polymerization initiator. The above-mentioned thermal radical polymerization initiator is an azo compound with a 10-hour half-life temperature of 65°C or less (Hereinafter, also referred to as "the thermal radical polymerization initiator of the present invention"). By containing the thermal radical polymerization initiator of the present invention, the sealing compound for liquid crystal display elements of the present invention has excellent reactivity at low temperatures, and the insertion of liquid crystal into the sealing compound or liquid crystal contamination caused by the sealing compound can be suppressed.

The azo compound, which is the thermal radical polymerization initiator of the present invention, has a 10-hour half-life temperature of 65°C or less, and therefore has excellent reactivity at low temperatures. The preferred upper limit of the 10-hour half-life temperature of the azo compound is 60°C, and the more preferred upper limit is 55°C.

In addition, from the viewpoint of making the obtained sealing compound for liquid crystal display elements more excellent in storage stability, the lower limit of the 10-hour half-life temperature of the azo compound is preferably 40°C, and more preferably, the lower limit is 45°C.

Furthermore, in this specification, the above-mentioned "10-hour half-life temperature of an azo compound" means that when the thermal decomposition reaction of the azo compound is carried out at a certain temperature in the presence of an inert gas for 10 hours, the concentration of the azo compound becomes the reaction The temperature at half an hour before the concentration.

The preferred lower limit of the melting point of the above-mentioned azo compound is 40°C, and the preferred upper limit is 125°C. When the melting point of the above-mentioned azo compound is in this range, the obtained sealing compound for liquid crystal display elements has both the curability at low temperature and the storage stability effect more excellent. The lower limit of the melting point of the above-mentioned azo compound is more preferably 45°C, and the more preferable upper limit is 120°C.

Furthermore, the melting point of the above-mentioned azo compound can be determined by differential scanning calorimetry.

The preferred lower limit of the molecular weight of the azo compound is 100, and the preferred upper limit is 400. By setting the molecular weight of the above-mentioned azo compound in this range, the effect of having both the curability at low temperature and the storage stability of the sealing compound for liquid crystal display elements obtained is more excellent. The lower limit of the molecular weight of the above-mentioned azo compound is more preferably 150, and the more preferable upper limit is 300.

The thermal radical polymerization initiator of the present invention is specifically preferably selected from 2,2'- Azobis(2,4-dimethylvaleronitrile) (10 hours half-life temperature 51℃, melting point 45℃~70℃), 2,2'-azobis(4-methoxy-2,4-bis Methylvaleronitrile) (10-hour half-life temperature 30°C, melting point 50°C~96°C), 2,2'-azobis(isobutyronitrile) (10-hour half-life temperature 65°C, melting point 100°C~103°C), 2,2'-Azobis(2-methylbutyronitrile) (10-hour half-life temperature 65℃, melting point 48℃~52℃), and 2,2'-azobis(2-methylpropionic acid) two At least one of the group consisting of dimethyl 2,2'-azobis(2-methylpropionate) (10 hours half-life temperature 66℃, melting point 22℃~28℃), more preferably 2,2'-azo Bis(2,4-dimethylvaleronitrile).

As the commercially available thermal radical polymerization initiator of the present invention, for example, V-59, V-60, V-65, V-70, V-601 (all manufactured by Wako Pure Chemical Industries, Ltd.) Wait.

The content of the thermal radical polymerization initiator of the present invention relative to 100 parts by weight of the above-mentioned curable resin, the preferred lower limit is 0.1 parts by weight, and the preferred upper limit is 5 parts by weight. By setting the content of the thermal radical polymerization initiator of the present invention within this range, the obtained sealing compound for liquid crystal display elements has both the curability at low temperatures and the storage stability more excellent. The lower limit of the thermal radical polymerization initiator of the present invention is more preferably 0.2 part by weight, and the upper limit is more preferably 1 part by weight.

The sealing compound for liquid crystal display elements of this invention contains a polymerization inhibitor.

The above-mentioned polymerization inhibitor is a compound having a naphthalene skeleton or an anthracene skeleton (hereinafter, also referred to as "the polymerization inhibitor of the present invention"). By using the polymerization inhibitor of the present invention as the above-mentioned polymerization inhibitor, the sealing compound for liquid crystal display elements of the present invention maintains the above-mentioned excellent curability obtained by using the thermal radical polymerization initiator of the present invention and is stable in storage Excellent sex.

Examples of the above-mentioned compound having a naphthalene skeleton include: 1-hydroxy-4-methoxynaphthalene, 1,4-dihydroxy-2-ammonium naphthalenesulfonate, 1,4-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, Hydroxy-2-naphthoic acid and so on.

Examples of the above-mentioned compound having an anthracene skeleton include 9,10-dibutoxyanthracene, 9-butoxyanthracene, and the like.

Among them, the above-mentioned polymerization inhibitor is preferably a compound having a naphthalene skeleton, more preferably 1-hydroxy-4-methoxynaphthalene.

With respect to 100 parts by weight of the curable resin, the content of the polymerization inhibitor of the present invention preferably has a lower limit of 0.01 part by weight, and a preferable upper limit of 1 part by weight. By setting the content of the polymerization inhibitor of the present invention within this range, the obtained sealing compound for liquid crystal display elements has both the curability at low temperature and the storage stability effect more excellent. The lower limit of the content of the polymerization inhibitor of the present invention is more preferably 0.02 parts by weight, and the upper limit is more preferably 0.5 parts by weight.

The sealing compound for liquid crystal display elements of this invention contains a curable resin.

The curable resin preferably contains a (meth)acrylic compound.

Furthermore, in this specification, the above-mentioned "(meth)acrylic acid" refers to acrylic acid or methacrylic acid, the above-mentioned "(meth)acrylic compound" refers to a compound having a (meth)acryloyl group, and the above-mentioned "( "Meth)acryloyl" refers to acryloyl or methacryloyl.

Examples of the (meth)acrylic compound include (meth)acrylic acid ester compounds obtained by reacting (meth)acrylic acid with a compound having a hydroxyl group, and (meth)acrylic acid ester compounds obtained by reacting (meth)acrylic acid with epoxy Epoxy (meth)acrylate obtained by reacting a compound, amine (meth)acrylate obtained by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group, etc. Among them, epoxy (meth)acrylate is preferred. In addition, from the viewpoint of reactivity, the (meth)acrylic compound described above is preferably one having two or more (meth)acrylic groups in one molecule.

Furthermore, in this specification, the above-mentioned "(meth)acrylate" refers to acrylate or methacrylate The above-mentioned "epoxy (meth)acrylate" refers to a compound obtained by reacting all epoxy groups in an epoxy compound with (meth)acrylic acid.

Examples of the monofunctional among the above-mentioned (meth)acrylate compounds include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and n-butyl (meth)acrylate. Ester, isobutyl (meth)acrylate, tertiary butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate , Isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, (meth) 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexyl (meth)acrylate, ( Isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxy (meth)acrylate Ethyl ester, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (Meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethyl carbitol (Meth)acrylate, (meth)acrylate 2,2,2-trifluoroethyl, (meth)acrylate 2,2,3,3-tetrafluoropropyl, (meth)acrylate 1H, 1H, 5H-octafluoropentyl ester, imine (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-(methyl) succinate ) Acrylic oxyethyl ester, hexahydrophthalic acid 2-(meth)acrylic acid oxyethyl ester, phthalic acid 2-(meth)acrylic acid oxyethyl 2-hydroxypropyl ester, phosphoric acid 2-(meth)acryloyloxyethyl, glycidyl (meth)acrylate and the like.

In addition, examples of the bifunctional ones in the above-mentioned (meth)acrylate compounds include 1,3-butanediol di(meth)acrylate and 1,4-butanediol di(meth) Acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol Di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate Base) acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, poly Propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide addition bisphenol A di(meth)acrylate, propylene oxide addition bisphenol A bis(methyl) )Acrylate, ethylene oxide addition bisphenol F di(meth)acrylate, dimethylol dicyclopentadiene di(meth)acrylate, ethylene oxide modified isocyanuric acid (Meth)acrylate, 2-hydroxy-3-(meth)acryloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth) Acrylate, polyesterdiol di(meth)acrylate, polycaprolactonediol di(meth)acrylate, polybutadienediol di(meth)acrylate, etc.

In addition, examples of the above-mentioned (meth)acrylate compounds having three or more functions include trimethylolpropane tri(meth)acrylate, ethylene oxide addition trimethylolpropane tri(methyl) )Acrylate, propylene oxide addition trimethylolpropane tri(meth)acrylate, caprolactone modified trimethylolpropane tri(meth)acrylate, ethylene oxide addition isocyanuric acid Acid tri(meth)acrylate, glycerol tri(meth)acrylate, propylene oxide addition glycerol tri(meth)acrylate, neopentylerythritol tri(meth)acrylate, phosphoric acid tri(meth) Acrylic oxyethyl ester, di(trimethylolpropane) tetra(meth)acrylate, neopentylerythritol tetra(meth)acrylate, dineopentaerythritol penta(meth)acrylate, dixin Pentaerythritol hexa(meth)acrylate and the like.

As said epoxy (meth)acrylate, the thing obtained by reacting an epoxy compound and (meth)acrylic acid in the presence of a basic catalyst according to a conventional method, etc. are mentioned, for example.

Epoxy as a raw material for synthesizing the above-mentioned epoxy (meth)acrylate Examples of the compound include: bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, 2,2'-diallyl bisphenol A epoxy resin, hydrogenated bisphenol Type epoxy resin, propylene oxide addition bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, thioether type epoxy resin, diphenyl ether type epoxy resin, two Cyclopentadiene epoxy resin, naphthalene epoxy resin, phenolic novolac epoxy resin, o-cresol novolac epoxy resin, dicyclopentadiene novolac epoxy resin, biphenyl novolac epoxy resin Type epoxy resin, naphthol novolac type epoxy resin, glycidylamine type epoxy resin, alkyl polyol type epoxy resin, rubber modified type epoxy resin, glycidyl ester compound, etc.

Examples of commercially available bisphenol A epoxy resins include jER828EL, jER1004 (all manufactured by Mitsubishi Chemical Corporation), EPICLON 850CRP (manufactured by DIC Corporation), and the like.

Examples of commercially available bisphenol F epoxy resins include jER806 and jER4004 (all manufactured by Mitsubishi Chemical Corporation).

As a commercially available one among the said bisphenol S-type epoxy resin, EPICLON EXA1514 (made by DIC Corporation) etc. are mentioned, for example.

As a commercially available one among the above-mentioned 2,2'-diallyl bisphenol A epoxy resins, for example, RE-810NM (manufactured by Nippon Kayaku Co., Ltd.) and the like can be cited.

As a commercially available one among the said hydrogenated bisphenol-type epoxy resin, EPICLON EXA7015 (made by DIC Corporation) etc. are mentioned, for example.

As a commercial one among the said propylene oxide addition bisphenol A type epoxy resin, EP-4000S (made by ADEKA company) etc. are mentioned, for example.

As a commercially available one among the above-mentioned resorcinol type epoxy resins, for example, EX-201 (长 Made by Se Kasei Corporation) and so on.

As a commercial item among the said biphenyl type epoxy resin, jER YX-4000H (made by Mitsubishi Chemical Corporation) etc. are mentioned, for example.

Examples of commercially available sulfide epoxy resins include YSLV-50TE (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) and the like.

As a commercially available one among the above-mentioned diphenyl ether type epoxy resins, YSLV-80DE (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) etc. are mentioned, for example.

As a commercially available one among the above-mentioned dicyclopentadiene-type epoxy resins, EP-4088S (made by ADEKA Corporation) etc. are mentioned, for example.

As commercially available among the above-mentioned naphthalene-type epoxy resins, for example, EPICLON HP4032, EPICLON EXA-4700 (all manufactured by DIC Corporation), and the like can be cited.

As a commercially available one among the said phenolic novolak type epoxy resins, EPICLON N-770 (made by DIC Corporation) etc. are mentioned, for example.

As a commercially available one among the said o-cresol novolak type epoxy resins, EPICLON N-670-EXP-S (made by DIC Corporation) etc. are mentioned, for example.

As a commercially available one among the said dicyclopentadiene novolak-type epoxy resins, EPICLON HP7200 (made by DIC Corporation) etc. are mentioned, for example.

As a commercial item among the said biphenol novolak type epoxy resin, NC-3000P (manufactured by Nippon Kayaku Co., Ltd.) etc. are mentioned, for example.

As a commercially available one among the naphthol novolak type epoxy resins, for example, ESN-165S (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) and the like can be cited.

As a commercially available one among the above-mentioned glycidylamine type epoxy resins, for example, jER630 (three Ryochemical Corporation), EPICLON 430 (manufactured by DIC Corporation), TETRAD-X (manufactured by Mitsubishi Gas Chemical Corporation), etc.

As commercially available among the above-mentioned alkyl polyol type epoxy resins, for example, ZX-1542 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), EPICLON 726 (manufactured by DIC Corporation), and EPOLIGHT 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.) ), DENACOL EX-611 (manufactured by Nagase Chemical Co., Ltd.), etc.

Examples of commercially available ones among the above-mentioned rubber-modified epoxy resins include YR-450, YR-207 (all manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), EPOLEAD PB (manufactured by Daicel), and the like.

As a commercial item among the said glycidyl ester compounds, DENACOL EX-147 (manufactured by Nagase Kasei Co., Ltd.) etc. are mentioned, for example.

As other commercially available ones among the above-mentioned epoxy compounds, for example, YDC-1312, YSLV-80XY, YSLV-90CR (all manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), XAC4151 (manufactured by Asahi Kasei Co., Ltd.), jER1031, jER1032 ( All are manufactured by Mitsubishi Chemical Corporation), EXA-7120 (manufactured by DIC Corporation), TEPIC (manufactured by Nissan Chemical Corporation), etc.

Examples of commercially available epoxy (meth)acrylates include: EBECRYL 860, EBECRYL 3200, EBECRYL 3201, EBECRYL 3412, EBECRYL 3600, EBECRYL 3700, EBECRYL 3701, EBECRYL 3702, EBECRYL 3703, EBECRYL 3800, EBECRYL 6040, EBECRYL RDX 63182 (all manufactured by Daicel Allnex), EA-1010, EA-1020, EA-5323, EA-5520, EA-CHD, EMA-1020 (all manufactured by Shinnakamura Chemical Industry Co., Ltd.), EPOXYESTER M-600A, EPOXYESTER 40EM, EPOXYESTER 70PA, EPOXYESTER 200PA, EPOXYESTER 80MFA, EPOXYESTER 3002M, EPOXYESTER 3002A, EPOXYESTER 1600A, EPOXYESTER 3000M, EPOXYESTER 3000A, EPOXYESTER 200EA, EPOXYESTER 400EA (all manufactured by Kyoeisha Chemical Co., Ltd.), DENACOL ACRYLATE DA-141, DENACOL ACRYLATE DA-314, DENACOL ACRYLATE DA-911 (all manufactured by Nagase Chemical Co.), etc.

As the above-mentioned (meth)acrylate amine ester obtained by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group, for example, it can be obtained by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxy group in the presence of a catalyst amount of a tin compound. It is obtained by reacting 1 equivalent of an isocyanate compound with one isocyanate group and 2 equivalents of a (meth)acrylic acid derivative having a hydroxyl group therewith.

Examples of the isocyanate compound used as the raw material of the amine (meth)acrylate include: isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hexamethylene diisocyanate, tri Methylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, toluidine diisocyanate , Xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, thiophosphate tris(isocyanatophenyl) ester, tetramethylxylylene diisocyanate , 1,6,11-Undecane triisocyanate, etc.

In addition, as the above-mentioned isocyanate compound used as the raw material of the (meth)acrylate amine ester, for example, it is also possible to use ethylene glycol, 1,2-propanediol, glycerol, sorbitol, trimethylolpropane, and two carbonates. A chain-extended isocyanate compound obtained by reacting polyols, polyether diols, polyester diols, polycaprolactone diols and other polyols with excess isocyanate compounds.

Examples of the (meth)acrylic acid derivative having a hydroxyl group used as the raw material of the (meth)acrylate amine ester include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, Mono (meth) propylene such as 2-hydroxybutyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate Hydroxyalkyl enoate, or glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, polyethylene glycol, etc. Mono(meth)acrylate, or mono(meth)acrylate or di(meth)acrylate of triol such as trimethylolethane, trimethylolpropane, glycerin, or bisphenol A type Epoxy (meth)acrylates such as epoxy acrylates, etc.

Examples of commercially available amine (meth)acrylate esters include: M-1100, M-1200, M-1210, M-1600 (all manufactured by Toagosei Co., Ltd.), EBECRYL 210, EBECRYL 220, EBECRYL 230, EBECRYL 270, EBECRYL 1290, EBECRYL 2220, EBECRYL 4827, EBECRYL 4842, EBECRYL 4858, EBECRYL 5129, EBECRYL 6700, EBECRYL 8402, EBECRYL 8803, EBECRYL 8804, EBECRYL 8RES, EBECRYL All 9260 (all manufactured by the company) UN-330, ARTRESIN SH-500B, ARTRESIN UN-1200TPK, ARTRESIN UN-1255, ARTRESIN UN-3320HB, ARTRESIN UN-7100, ARTRESIN UN-9000A, ARTRESIN UN-9000H (all manufactured by Negami Kogyo), U-2HA , U-2PHA, U-3HA, U-4HA, U-6H, U-6HA, U-6LPA, U-10H, U-15HA, U-108, U-108A, U-122A, U-122P, U -324A, U-340A, U-340P, U-1084A, U-2061BA, UA-340P, UA-4000, UA-4100, UA-4200, UA-4400, UA-5201P, UA-7100, UA-7200 , UA-W2A (all manufactured by Shinnakamura Chemical Industry Co., Ltd.), AH-600, AI-600, AT-600, UA-101I, UA-101T, UA-306H, UA-306I, UA-306T (all are common Eisha Chemical Co., Ltd.) and so on.

In order to improve the adhesiveness of the sealing compound for liquid crystal display elements obtained, the said curable resin may contain an epoxy compound. Examples of the epoxy compound include an epoxy compound used as a raw material for synthesizing the epoxy (meth)acrylate, a partially (meth)acrylic modified epoxy resin, and the like.

Furthermore, in this specification, the above-mentioned partially (meth)acrylic modified epoxy resin refers to those having one or more epoxy groups and one or more (meth)acrylic groups in one molecule. The compound can be obtained, for example, by reacting a part of epoxy groups of an epoxy compound having two or more epoxy groups in one molecule with (meth)acrylic acid.

As a commercially available one among the above-mentioned partially (meth)acrylic modified epoxy resins, for example, UVACURE 1561 (manufactured by Daicel Allnex) and the like can be cited.

When the sealing compound for liquid crystal display elements of the present invention contains the (meth)acrylic compound and the epoxy compound, it is preferable that the ratio of the (meth)acryloyl group to the epoxy group is 30:70 to 95 : In the mode of 5, the above-mentioned (meth)acrylic compound and the above-mentioned epoxy compound are blended. By setting the ratio of the (meth)acryloyl group to the epoxy group in this range, the occurrence of liquid crystal contamination is suppressed, and the adhesiveness of the obtained sealing compound for liquid crystal display elements is more excellent.

From the viewpoint of suppressing liquid crystal contamination, the curable resin is preferably one having hydrogen bonding units such _{as -OH group, -NH- group, and -NH 2 group.}

The sealing compound for liquid crystal display elements of this invention may contain a photoradical polymerization initiator in addition to the said thermal radical polymerization initiator.

等。 Examples of the aforementioned photoradical polymerization initiator include benzophenone-based compounds, acetophenone-based compounds, phosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, Benzol, 9-oxysulfur

Wait.

Examples of commercially available photo radical polymerization initiators include: IRGACURE 184, IRGACURE 369, IRGACURE 379, IRGACURE 651, IRGACURE 819, IRGACURE 907, IRGACURE 2959, IRGACURE OXE 01, LUCIRIN TPO (all BASF Manufactured by the company), benzoin methyl ether, benzoin ethyl ether, benzoin Isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.), etc.

The content of the photo radical polymerization initiator relative to 100 parts by weight of the curable resin has a preferred lower limit of 0.1 parts by weight and a preferred upper limit of 10 parts by weight. By setting the content of the photoradical polymerization initiator in this range, the effect of improving the photocurability without impairing the weather resistance of the obtained sealing compound for liquid crystal display elements is more excellent. The lower limit of the content of the photo radical polymerization initiator is more preferably 0.2 parts by weight, and the upper limit is more preferably 8 parts by weight.

The sealing compound for liquid crystal display elements of this invention may contain a thermosetting agent.

As said thermosetting agent, organic acid hydrazine, imidazole derivatives, amine compounds, polyphenol compounds, acid anhydrides, etc. are mentioned, for example. Among them, it is suitable to use solid organic acid hydrazine.

Examples of the above-mentioned solid organic acid hydrazine include: 1,3-bis(hydrazinocarbonylethyl-5-isopropylhydantoin), dihydrazine sebacate, and dihydrazide isophthalate , Dihydrazine adipic acid, Dihydrazine malonate, etc., as commercially available ones, for example, AMICURE VDH, AMICURE UDH (all manufactured by Ajinomoto Fine-Techno), SDH, IDH, ADH (all Otsuka Chemical company manufacturing), MDH (Japan Finechem company manufacturing), etc.

The content of the thermosetting agent relative to 100 parts by weight of the curable resin has a preferred lower limit of 1 part by weight, and a preferred upper limit of 50 parts by weight. By setting the content of the above-mentioned thermosetting agent in this range, the thermosetting properties can be further improved without deteriorating the coating properties and the like of the obtained sealing compound for liquid crystal display elements. The more preferable upper limit of the content of the thermal hardening agent is 30 parts by weight.

The sealing compound for liquid crystal display elements of the invention preferably contains an inorganic filler in order to increase the viscosity, improve the adhesion obtained by the stress dispersion effect, improve the linear expansion rate, and improve the moisture permeability of the cured product. .

Examples of the above-mentioned inorganic fillers include: silica, talc, glass beads, asbestos, gypsum, diatomaceous earth, bentonite, bentonite, montmorillonite, sericite, activated clay, alumina, zinc oxide , Iron oxide, magnesium oxide, tin oxide, titanium oxide, calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum nitride, silicon nitride, barium sulfate, calcium silicate, etc.

The lower limit of the content of the inorganic filler in the sealing compound for liquid crystal display elements of the present invention is preferably 10% by weight, and the upper limit is preferably 70% by weight. By setting the content of the filler in this range, the effect of improving adhesiveness, etc., is more excellent without deteriorating coatability and the like. The lower limit of the content of the above-mentioned inorganic filler is more preferably 20% by weight, and the more preferable upper limit is 60% by weight.

It is preferable that the sealing compound for liquid crystal display elements of this invention contains a silane coupling agent. The above-mentioned silane coupling agent mainly has a role as an adhesive auxiliary agent for bonding a sealant to a substrate, etc. satisfactorily.

As the above-mentioned silane coupling agent, in terms of the effect of improving the adhesion to the substrate, etc., and the ability to chemically bond with the curable resin to suppress the outflow of the curable resin into the liquid crystal, it is suitable to use, for example, 3-amine Propyl propyl trimethoxy silane, 3-mercaptopropyl trimethoxy silane, 3-glycidoxy propyl trimethoxy silane, 3-isocyanato propyl trimethoxy silane, etc.

The lower limit of the content of the silane coupling agent in the sealing compound for liquid crystal display elements of the present invention is preferably 0.1% by weight, and the upper limit is preferably 10% by weight. By setting the content of the silane coupling agent in this range, the effect of suppressing the occurrence of liquid crystal contamination and improving adhesion is more excellent. The lower limit of the content of the silane coupling agent is more preferably 0.3% by weight, and the upper limit is more preferably 5% by weight.

The sealing compound for liquid crystal display elements of this invention preferably contains soft particles. The above-mentioned soft particles serve as barriers between the other sealant components and the liquid crystal during the production of liquid crystal display elements. By containing the above-mentioned soft particles, the sealing compound for liquid crystal display elements of the present invention can inhibit the insertion of liquid crystal into the sealing compound or the sealing compound The liquid crystal pollution caused by the effect is better.

The maximum particle size of the above-mentioned soft particles is preferably at least 100% of the cell gap of the liquid crystal display device, which is 5-20 μm. The above-mentioned soft particles can cause springback by using the maximum particle size of 100% or more of the cell gap, but by setting the maximum particle size of the above-mentioned soft particles to 20μm or less, the gap defect caused by the springback can not be caused. Under the circumstances, liquid crystal display elements are produced.

Furthermore, the cell gap of a liquid crystal display element differs depending on the display element, so it is not limited, but the cell gap of a typical liquid crystal display element is 2μm~10μm.

The preferred lower limit of the maximum particle size of the soft particles is 100% of the cell gap of the liquid crystal display device, which is 5 μm. That is, when the cell gap of the liquid crystal display element is 5 μm or less, the lower limit of the maximum particle size of the soft particles is preferably 5 μm, and when the cell gap of the liquid crystal display element exceeds 5 μm, the maximum particle diameter of the soft particles The preferred lower limit is 100% of the cell gap of the liquid crystal display element. By making the maximum particle size of the soft particles 5 μm and the above value of 100% of the cell gap of the liquid crystal display element to be the preferred lower limit value or more, the effect of suppressing seal fracture or liquid crystal contamination is more excellent.

In addition, from the viewpoint of suppressing the decrease in adhesiveness caused by springback or the gap defect of the liquid crystal display element, the preferred upper limit of the maximum particle size of the soft particles is 20 μm. A more preferable upper limit of the maximum particle size of the soft particles is 15 μm. Furthermore, from the viewpoint of suppressing the drop in adhesiveness caused by springback or the gap defect of the liquid crystal display element, the maximum particle size of the soft particles is preferably 2.6 times or less of the cell gap. The better upper limit of the maximum particle size of the above soft particles It is 2.2 times the cell gap, and the preferred upper limit is 1.7 times the cell gap.

Furthermore, in this specification, the maximum particle size of the above-mentioned soft particles and the following average particle size are obtained by measuring the particles before blending into the sealant using a laser diffraction particle size distribution measuring device The value. As the above-mentioned laser diffraction type distribution measuring device, MASTERSIZER 2000 (manufactured by Malvern Instruments Ltd.) or the like can be used.

The soft particles preferably have a particle size distribution of the soft particles measured by the laser diffraction type distribution measuring device, and the content ratio of particles with a particle size of 5 μm or more is 60% or more in terms of volume frequency. By making the content ratio of particles with a particle diameter of 5 μm or more 60% or more in terms of volume frequency, the effect of suppressing seal fracture or liquid crystal contamination is more excellent. The content of particles with a particle size of 5 μm or more is more preferably 80% or more.

From the viewpoint of further exerting the effect of suppressing the occurrence of seal fracture or liquid crystal contamination, the above-mentioned soft particles are preferably particles that contain more than 70% of the particle size distribution of the entire soft particles and 100% or more of the cell gap of the liquid crystal display element. More preferably, it is composed of particles that are more than 100% of the cell gap of the liquid crystal display element.

The preferred lower limit of the average particle diameter of the soft particles is 2 μm. By making the average particle diameter of the above-mentioned soft particles 2 μm or more, the effect of suppressing the sealing fracture or the contamination of the liquid crystal is more excellent. The lower limit of the average particle diameter of the soft particles is more preferably 4 μm.

In addition, from the viewpoint of suppressing the decrease in adhesiveness caused by springback or the gap defect of the liquid crystal display element, the preferred upper limit of the average particle diameter of the soft particles is 15 μm. The more preferable upper limit of the average particle diameter of the soft particles is 12 μm.

As the above-mentioned soft particles, two or more types of soft particles with different maximum particle diameters may be mixed and used. That is, the maximum particle size can also be less than 100% of the cell gap of the liquid crystal display element The soft particles are mixed with soft particles whose maximum particle size is more than 100% of the cell gap of the liquid crystal display element.

The coefficient of variation of the particle diameter of the soft particles (hereinafter also referred to as CV value) is preferably 30% or less from the viewpoint of suppressing cell gap defects. The CV value of the particle diameter of the soft particles is more preferably 28% or less.

In addition, the CV value of the particle diameter in this specification refers to the value obtained by the following formula.

CV value of particle size (%)=(standard deviation of particle size/average particle size)×100

Even if the above-mentioned soft particles have a maximum particle diameter, an average particle diameter, or a CV value outside the above range, they can be classified so that the maximum particle diameter, average particle diameter, or CV value is within the above range. In addition, soft particles with a particle size of less than 100% of the cell gap of the liquid crystal display element do not help to suppress the occurrence of seal fracture or liquid crystal contamination, and the thixotropy value may increase if the sealant is blended, so it is preferable To be removed in advance by classification.

As a method of classifying the above-mentioned soft particles, for example, methods such as wet classification and dry classification can be cited. Among them, wet classification is preferred, and wet sieve classification is more preferred.

Examples of the above-mentioned flexible particles include silicone-based particles, vinyl-based particles, urethane-based particles, fluorine-based particles, and nitrile-based particles. Among them, polysiloxane-based particles and vinyl-based particles are preferred.

The above-mentioned silicone-based particles are preferably silicone rubber particles from the viewpoint of dispersibility into the resin.

Examples of commercially available polysiloxane-based particles include: KMP-594, KMP-597, KMP-598, KMP-600, KMP-601, KMP-602 (manufactured by Shin-Etsu Silicones), TREFIL E-506S, EP-9215 (manufactured by Toray Dow Corning Co., Ltd.), etc., can be classified and used. The above-mentioned silicone-based particles may be used singly, or two or more of them may be used in combination.

As the above-mentioned vinyl-based particles, (meth)acrylic particles are suitably used.

The above-mentioned (meth)acrylic particles can be obtained by polymerizing monomers used as raw materials by a known method. Specifically, for example, a method of suspension polymerization of monomers in the presence of a radical polymerization initiator; in the presence of a radical polymerization initiator, the monomer can be absorbed by non-crosslinked particles. , The method of swelling the seed particles and polymerizing the seeds, etc.

As a monomer used as a raw material for forming the above-mentioned (meth)acrylic particles, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and (meth)acrylate can be cited. Butyl acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, ( Stearyl meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate and other alkyl (meth)acrylates, or 2-hydroxyethyl (meth)acrylate, (meth)acrylate (Meth)acrylates containing oxygen atoms such as glyceryl acrylate, polyoxyethylene (meth)acrylate, glycidyl (meth)acrylate, etc., or nitrile-containing monomers such as (meth)acrylonitrile, Or monofunctional monomers such as fluorine-containing (meth)acrylates such as trifluoromethyl (meth)acrylate and pentafluoroethyl (meth)acrylate. Among them, in terms of the low Tg of the homopolymer and the ability to increase the amount of deformation when a load of 1 g is applied, alkyl (meth)acrylates are preferred.

Furthermore, in order to have a crosslinked structure, tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, Trimethylolpropane tri(meth)acrylate, dineopentaerythritol hexa(meth)acrylate, dineopentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, diglycerol (Meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, (poly)tetramethylene di(meth)acrylate, 1, 4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylic acid Polyfunctional monomers such as esters and isocyanuric acid skeleton tri(meth)acrylates. Among them, (poly)ethylene glycol di(meth)acrylate and (poly)propylene glycol di(poly)propylene glycol di(poly)ethylene glycol di(meth)acrylate are preferred in terms of the large molecular weight between crosslinking points and the ability to increase the amount of deformation when a load of 1 g is applied. Meth) acrylate, (poly)tetramethylene di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth) Acrylate.

The amount of the crosslinkable monomer used in the entire monomer used as the raw material for forming the (meth)acrylic particles is preferably 1% by weight in the lower limit, and 90% by weight in the upper limit. By setting the usage amount of the above-mentioned crosslinkable monomer to 1% by weight or more, solvent resistance is improved, and it does not cause problems such as swelling when kneaded with various sealant raw materials, and it becomes easy to uniformly disperse. By making the use amount of the above-mentioned crosslinkable monomer 90% by weight or less, the recovery rate can be reduced, and it becomes difficult to cause problems such as springback. The lower limit of the amount of the crosslinkable monomer used is more preferably 3% by weight, and the upper limit is more preferably 80% by weight.

Furthermore, in addition to the acrylic monomers, styrene-based monomers such as styrene and α-methylstyrene, or vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether can also be used. Type, or acid vinyl esters such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate, or unsaturated hydrocarbons such as ethylene, propylene, isoprene, butadiene, or chlorinated ethylene Ester, fluorinated vinyl ester, chlorostyrene and other halogen-containing monomers, or triallyl (iso)cyanurate, triallyl trimellitate, divinylbenzene, diallyl phthalate , Diallyl acrylamide, diallyl ether, γ-(meth) acryloxy propyl trimethoxysilane, trimethoxysilyl styrene, vinyl trimethoxysilane and other monomers.

In addition, as the aforementioned vinyl-based particles, for example, polydivinylbenzene particles, polychloroprene particles, butadiene rubber particles, and the like can also be used.

As a commercially available one among the above-mentioned urethane-based particles, for example, ARTPEARL (Manufactured by Nejo Industry Co., Ltd.), DAIMIC BEAZ (manufactured by Dainichi Seiki Chemical Co., Ltd.), etc., can be used by classifying them.

From the viewpoint of suppressing the deterioration of the adhesiveness of the obtained sealant for liquid crystal display elements or the defect of the gap of the obtained liquid crystal display elements, the hardness of the soft particles is preferably 10 in the lower limit and 50 in the upper limit. A more preferable lower limit of the hardness of the soft particles is 20, and a more preferable upper limit is 40.

Furthermore, in this specification, the hardness of the above-mentioned soft particles refers to the durometer A hardness measured by a method based on JIS K 6253.

The lower limit of the content of the soft particles relative to the entire sealing compound for liquid crystal display elements is preferably 15% by weight. By making the content of the above-mentioned soft particles 15% by weight or more, the effect of suppressing the occurrence of seal fracture or liquid crystal contamination is more excellent. The lower limit of the content of the soft particles is more preferably 20% by weight. In addition, from the viewpoint of suppressing the drop in adhesiveness due to springback or the gap defect of the liquid crystal display element, the content of the soft particles is preferably 50% by weight with respect to the entire sealing compound for liquid crystal display elements. The more preferable upper limit of the content of the soft particles is 40% by weight.

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

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

The above-mentioned titanium black is a substance that has a higher transmittance in the vicinity of the ultraviolet region, especially light with a wavelength of 370 to 450 nm, compared to the average transmittance of light with a wavelength of 300 to 800 nm. That is, the above-mentioned titanium black is effective to the liquid crystal of the present invention by sufficiently shielding the light of the wavelength of the visible light region. The sealant for display elements imparts light-shielding properties. On the other hand, it is a light-shielding agent that has the property of transmitting light of a wavelength near the ultraviolet region. The light-shielding agent contained in the sealing compound for liquid crystal display elements of the present invention is preferably a material with high insulation, and titanium black is also preferable as a light-shielding agent with high insulation.

The above-mentioned titanium black exhibits sufficient effects even if the surface is not treated. However, titanium black whose surface is treated with organic ingredients such as coupling agent, or silicon oxide, titanium oxide, germanium oxide, aluminum oxide, and oxide can also be used. Titanium black coated with inorganic components such as zirconium, magnesium oxide and other surface-treated titanium black. Among them, titanium black treated with organic components is preferable in terms of further improving insulation.

In addition, the liquid crystal display element manufactured using the sealant for liquid crystal display elements of the present invention containing the titanium black as a light-shielding agent has sufficient light-shielding properties, so that no light leakage can be achieved, and the liquid crystal display element has a high contrast ratio and is excellent Image display quality liquid crystal display element.

Examples of commercially available titanium blacks include 12S, 13M, 13M-C, 13R-N, and 14M-C (all manufactured by Mitsubishi Materials), TILACK D (manufactured by Ako Chemical Co., Ltd.), and the like.

The preferred lower limit of the specific surface area of the titanium black is 13 m ² /g, the preferred upper limit is 30 m ² /g, the more preferred lower limit is 15 m ² /g, and the more preferred upper limit is 25 m ² /g.

In addition, the lower limit of the volume resistance of the above-mentioned titanium black is preferably 0.5Ω. cm, the preferred upper limit is 3Ω. cm, the better lower limit is 1Ω. cm, the more preferable upper limit is 2.5Ω. cm.

The primary particle size of the light-shielding agent is not particularly limited as long as it is less 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 5000 nm. By making the primary particle diameter of the said light-shielding agent into this range, it can become a thing with more excellent light-shielding property without worsening the coatability etc. of the sealing compound for liquid crystal display elements obtained. Of the above sunscreen A more preferable lower limit of the primary particle size is 5 nm, a more preferable upper limit is 200 nm, a still more preferable lower limit is 10 nm, and a more preferable upper limit is 100 nm.

In addition, the primary particle size of the sunscreen can be measured by dispersing the sunscreen in a solvent (water, organic solvent, etc.) using NICOMP 380ZLS (manufactured by PARTICLE SIZING SYSTEMS).

The lower limit of the content of the light-shielding agent in the sealing compound for liquid crystal display elements of the present invention is preferably 5% by weight, and the upper limit is preferably 80% by weight. By setting the content of the above-mentioned light-shielding agent in this range, it is possible to exhibit more excellent light-shielding without deteriorating the adhesion to the substrate of the obtained sealing compound for liquid crystal display elements, the strength after curing, or the drawing properties. Sex. The lower limit of the content of the sunscreen is more preferably 10% by weight, the upper limit is more preferably 70% by weight, the lower limit is still more preferably 30% by weight, and the upper limit is more preferably 60% by weight.

The sealing compound for liquid crystal display elements of the present invention may further contain additives such as a stress reliever, a reactive diluent, a thixotropic agent, a spacer, a hardening accelerator, a defoamer, and a leveling agent as necessary.

As a method of manufacturing the sealing compound for liquid crystal display elements of the present invention, for example, the curable resin is mixed with a mixer such as a homogeneous disperser, a homomixer, a universal mixer, a planetary mixer, a kneader, and a three-roll mill. , The method of mixing thermal radical polymerization initiator, polymerization inhibitor, and optionally silane coupling agent and other additives.

By blending conductive fine particles into the sealing compound for liquid crystal display elements of the present invention, a vertical conduction material can be produced. Such an upper and lower conduction material containing the sealing compound for liquid crystal display elements of the present invention and conductive fine particles is also one of the present invention.

As the conductive fine particles, metal balls and resin fine particles can be used. A conductive metal layer is formed on the surface. Among them, those with a conductive metal layer formed on the surface of the resin particles are suitable due to the excellent elasticity of the resin particles, which can be electrically connected without damaging the transparent substrate or the like.

The liquid crystal display element which uses the sealing compound for liquid crystal display elements of this invention or the top and bottom conduction material of this invention is also one of this invention.

As a method of manufacturing the liquid crystal display element of this invention, it is suitable to use a liquid crystal dropping method. Specifically, for example, a method having the following steps: by screen printing, dispenser coating, etc., the sealant for liquid crystal display elements of the present invention is coated on a glass substrate with electrodes such as an ITO film or a pair The step of forming a frame-shaped seal pattern on one of two substrates such as an ethylene phthalate substrate; in a state where the sealant for liquid crystal display elements of the present invention is not hardened, droplets of liquid crystal are applied to The step of overlapping with another substrate in the frame of the sealing pattern of the substrate under vacuum; and the step of heating and hardening the sealant for the liquid crystal dropping method of the present invention. In addition, before the step of heating and hardening the sealant for liquid crystal dropping methods of the present invention, a step of temporarily hardening the sealant by irradiating the seal pattern portion with light such as ultraviolet rays may be performed.

According to the present invention, it is possible to provide a sealing compound for a liquid crystal display element which is excellent in storage stability and can suppress insertion of liquid crystal into the sealing compound or liquid crystal contamination caused by the sealing compound. In addition, according to the present invention, it is possible to provide an upper and lower conduction material and a liquid crystal display element manufactured using the sealant for liquid crystal display elements.

Hereinafter, the present invention will be further described in detail with examples, but the present invention is not limited to these examples.

(Examples 1 to 12, Comparative Examples 1 to 3)

According to the blending ratios described in Tables 1 to 3, each material was stirred using a planetary stirring device ("Defoaming Nentaro" manufactured by Thinky), and then uniformly mixed using a ceramic three-roll mill to obtain Examples 1 to 12. The sealing compound for liquid crystal display elements of Comparative Examples 1 to 3.

<evaluation>

The following evaluation was performed about each sealing compound for liquid crystal display elements obtained in an Example and a comparative example. The results are shown in Tables 1 to 3.

(1) Storage stability

About each sealing compound for liquid crystal display elements obtained in an Example and a comparative example, the state after storing at 25 degreeC for 168 hours was confirmed. The case where gelation is not confirmed for the sealant after storage is set to "○", and the case where gelation is confirmed for the sealant after storage is set to "×" to evaluate the storage stability of the sealant.

Furthermore, after the sealant is stirred with a spatula, the fluidity during dripping is significantly lower than before storage, and it is judged as gelation.

(2) Hardening

Using a dispenser ("SHOTMASTER 300" manufactured by Musashi High-Tech Co., Ltd.), a small amount of each liquid crystal display element sealant obtained in the examples and comparative examples was applied on a glass substrate, and the PET film was laminated, and then heated at 120°C Heat for 60 minutes to harden the sealant. Among them, the sealing compound for liquid crystal display elements obtained in Example 10 was irradiated with an ^{ultraviolet ray of 3000 mJ/cm 2} using a metal halide lamp, and then heated at 120° C. for 60 minutes to harden the sealing compound. The spectrum of the cured product of the sealant obtained was measured by the micro-IR method, ^{the peak area of 815~800cm -1 was taken as} the peak area of (meth)acrylic acid base, and the peak area of 845~820cm ^-1 was taken as With reference to the peak area, the conversion rate of the (meth)acryloyl group was calculated using the following formula. The conversion rate was 95% or more as "○", the conversion rate was 90% or more and less than 95% was "△", and the conversion rate was less than 90% was "×", and the curability was evaluated.

Conversion rate of (meth)acrylic acid group (%)=100×(1-((meth)acrylic acid group peak area after ultraviolet irradiation/reference peak area after ultraviolet irradiation)/(before ultraviolet irradiation (( (Methyl) Acrylic peak area / Reference peak area before UV irradiation))

(3) Anti-insertion

The sealing compound for each liquid crystal display element obtained in the Examples and Comparative Examples was filled in a syringe for dripping ("PSY-10E" manufactured by Musashi High-Tech Co., Ltd.), and defoaming treatment was performed. Then, a dispenser (manufactured by Musashi High-Tech Co., "SHOTMASTER 300") was used to apply the sealant by drawing a rectangular frame on the transparent electrode substrate with the ITO film. Then, a liquid crystal dropping device was used to drop the droplets coated with TN liquid crystal (“JC-5001LA” manufactured by Chisso Corporation), and another transparent substrate was bonded using a vacuum bonding device under a reduced pressure of 5 Pa. The unit after bonding is heated at 120°C for 60 minutes to harden the sealant. Among them, the sealing compound for liquid crystal display elements obtained in Example 10 was irradiated with an ^{ultraviolet ray of 3000 mJ/cm 2} using a metal halide lamp, and then heated at 120° C. for 60 minutes to harden the sealing compound. With regard to the obtained liquid crystal display element, the insertion of the liquid crystal (especially the corner) around the sealing portion was visually observed. Set the liquid crystal insertion to 1/4 of the line width as "○", and the liquid crystal insertion to half the line width as "△" to break the sealing part (seal fracture) due to the insertion of the liquid crystal Set to "×" and evaluate the anti-insertion property.

(4) The display performance of the liquid crystal display element (low liquid crystal pollution)

The sealing compound for each liquid crystal display element obtained in the Examples and Comparative Examples was filled in a syringe for dripping ("PSY-10E" manufactured by Musashi High-Tech Co., Ltd.), and defoaming treatment was performed. Then, a dispenser (manufactured by Musashi High-Tech Co., "SHOTMASTER 300") was used to apply the sealant by drawing a rectangular frame on the transparent electrode substrate with the ITO film. Then, a liquid crystal dropping device was used to drop the droplets coated with TN liquid crystal (“JC-5001LA” manufactured by Chisso Corporation), and another transparent substrate was bonded using a vacuum bonding device under a reduced pressure of 5 Pa. The unit after bonding is heated at 120°C for 60 minutes to harden the sealant. Among them, the sealing compound for liquid crystal display elements obtained in Example 10 was irradiated with an ^{ultraviolet ray of 3000 mJ/cm 2} using a metal halide lamp, and then heated at 120° C. for 60 minutes to harden the sealing compound.

Regarding the obtained liquid crystal display element, visually observe the display unevenness caused by the liquid crystal around the sealing part (especially the corners), and set the unconfirmed display unevenness to "○", and the display unevenness will be confirmed Set to "×" to evaluate the display performance (low liquid crystal contamination) of the liquid crystal display element.

[Industrial availability]

According to the present invention, it is possible to provide a sealing compound for a liquid crystal display element which is excellent in storage stability and can suppress insertion of liquid crystal into the sealing compound or liquid crystal contamination caused by the sealing compound. also, According to the present invention, it is possible to provide an upper and lower conduction material and a liquid crystal display element manufactured using the sealant for liquid crystal display elements.

Claims (9)

A sealant for liquid crystal display elements, which contains a curable resin, a thermal radical polymerization initiator, and a polymerization inhibitor, characterized in that the thermal radical polymerization initiator is a couple with a 10-hour half-life temperature of 65°C or less Nitrogen compound, the above-mentioned polymerization inhibitor is a compound having a naphthalene skeleton or an anthracene skeleton. For example, the sealing compound for liquid crystal display elements in the first item of the scope of patent application, wherein the melting point of the azo compound is 40℃~125℃. For example, the sealing compound for liquid crystal display elements in the first or second item of the scope of patent application, wherein the azo compound is selected from 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'- Azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile) ), and at least one of the group consisting of 2,2'-azobis(2-methylpropionate) dimethyl (dimethyl 2,2'-azobis(2-methylpropionate)). For example, the sealing compound for liquid crystal display elements in the third item of the scope of patent application, wherein the azo compound is 2,2'-azobis(2,4-dimethylvaleronitrile). For example, the sealing compound for liquid crystal display elements of the first or second patent application, wherein the polymerization inhibitor is a compound having a naphthalene skeleton. For example, the sealing compound for liquid crystal display elements of the fifth item of the scope of patent application, wherein the polymerization inhibitor is 1-hydroxy-4-methoxynaphthalene. For example, the sealing compound for liquid crystal display elements of the first or second item of the scope of patent application contains a light-shielding agent. An up-and-down conduction material containing the sealant for liquid crystal display elements of 1, 2, 3, 4, 5, 6 or 7 in the scope of patent application and conductive fine particles. A liquid crystal display element, which is formed by using the sealant for liquid crystal display elements of item 1, 2, 3, 4, 5, 6 or 7 of the scope of patent application or the upper and lower conductive materials of item 8 of the scope of patent application.