JP7295798B2 - liquid crystal display element - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sealant for liquid crystal display elements, which has excellent storage stability and curability, and which can suppress the occurrence of display defects even when used in thin liquid crystal display elements. The present invention also relates to a vertically conductive material and a liquid crystal display element using the sealant for a liquid crystal display element.

In recent years, as a method for manufacturing a liquid crystal display element such as a liquid crystal display cell, from the viewpoint of shortening the tact time and optimizing the amount of liquid crystal used, dropping using a sealing agent as disclosed in Patent Document 1 and Patent Document 2 A liquid crystal dropping method called construction method is used.
In the dropping method, first, a frame-shaped seal pattern is formed on one of the two electrode-attached substrates by dispensing. Next, liquid crystal microdroplets are dropped into the frame of the seal pattern while the sealant is not yet cured, and the other substrate is superimposed under vacuum, and the sealant is cured to fabricate a liquid crystal display element. At present, this dripping method is the mainstream method for manufacturing liquid crystal display elements.

By the way, in the present age when various mobile devices with liquid crystal panels such as mobile phones and portable game machines are widely used, miniaturization of devices is the most demanded issue. As a method for downsizing the device, narrowing the frame of the liquid crystal display part is mentioned, and for example, the position of the seal part is arranged under the black matrix (hereinafter also referred to as narrow frame design).

However, in the narrow frame design, the sealant is placed directly under the black matrix, so if the drip method is used, the light emitted during photo-curing of the sealant is blocked, making it difficult for the light to reach the inside of the sealant. , curing is insufficient with conventional sealants. Insufficient curing of the sealant causes the problem that the uncured sealant components are easily eluted into the liquid crystal to cause liquid crystal contamination.

If it is difficult to photo-cure the sealant in this manner, it may be possible to cure the sealant by heating. As a method for curing the sealant by heating, a thermosetting agent is added to the sealant. It is However, when a thermosetting agent having high reactivity to heat is used to improve the curability of the sealant, the resulting sealant may have poor storage stability.
In recent years, liquid crystal display elements have become thinner, but there has been a problem that display defects may occur when conventional sealants are used in thin liquid crystal display elements.

JP-A-2001-133794 WO 02/092718

An object of the present invention is to provide a sealant for a liquid crystal display element which is excellent in storage stability and curability and which can suppress the occurrence of display defects even when used in a thin liquid crystal display element. Another object of the present invention is to provide a vertically conductive material and a liquid crystal display element using the sealant for a liquid crystal display element.

The present invention provides a liquid crystal display element sealing compound containing a curable resin and a thermosetting agent , and a liquid crystal display element using a liquid crystal , wherein the thermosetting agent has a solubility parameter of 40.0 (J /cm ³ ) ^1/2 or more and 60.0 (J/cm ³ ) ^1/2 or less , and the liquid crystal has a solubility parameter of 22.0 (J/cm 3 ) ^1/2 or more and 50.0 (J/cm ³ ) 1/2 or more. The liquid crystal display element is 0 (J/cm ³ ) ^1/2 or less .
The present invention will be described in detail below.

In response to thinning of liquid crystal display elements, highly polar liquid crystals containing liquid crystal molecules having polar groups such as fluoro groups, chloro groups, and cyano groups are increasingly used as liquid crystals. The inventor of the present invention believes that the cause of display failure when using a conventional sealant in a thin liquid crystal display element is the compatibility between the sealant and the highly polar liquid crystal containing liquid crystal molecules having such a polar group ( In particular, the high compatibility with the thermosetting agent contained in the sealant made liquid crystal contamination more likely to occur. Therefore, the present inventors have found that by using a hydrazide compound having a solubility parameter within a specific range as a heat curing agent, the storage stability and curability are excellent, and display defects occur even when used in a thin liquid crystal display device. The present inventors have found that a sealant for liquid crystal display elements capable of suppressing this can be obtained, and have completed the present invention.
The sealant for a liquid crystal display element of the present invention has even lower compatibility with conventional liquid crystals having low polarity, so that display defects do not occur even in liquid crystal display elements using such conventional liquid crystals. The occurrence can be suppressed.

The sealant for liquid crystal display elements of the present invention contains a thermosetting agent.
The thermosetting agent forms a covalent bond with the epoxy group or (meth)acryloyl group in the sealing agent for liquid crystal display elements by heating to crosslink the adhesive property and moisture resistance of the sealing agent for liquid crystal display elements after curing. It has a role to improve.
In addition, in this specification, the above-mentioned "(meth)acryloyl" means acryloyl or methacryloyl.

The thermosetting agent contains a hydrazide compound having a solubility parameter (hereinafter also referred to as “SP value”) of 37.0 (J/cm ³ ) ^1/2 or more and 60.0 (J/cm ³ ) ^{1/2 or} less. . Hereinafter, a hydrazide compound having an SP value of 37.0 (J/cm ³ ) ^1/2 or more and 60.0 (J/cm ³ ) ^{1/2 or} less is also referred to as "a hydrazide compound according to the present invention".
By containing a hydrazide compound having an SP value within this range, the sealant for a liquid crystal display element of the present invention is excellent in storage stability and curability, and causes display defects even when used in a thin liquid crystal display element. The occurrence can be suppressed. A preferable lower limit of the SP value of the hydrazide compound according to the present invention is 40 (J/cm ³ ) ^1/2 , and a more preferable lower limit is 45 (J/cm ³ ) ^1/2 .
A preferable upper limit of the SP value of the hydrazide compound according to the present invention is 50.0 (J/cm ³ ) ^1/2 .
In the present specification, the "SP value" is a value calculated based on the calculation method devised by Fedors (Journal of the Adhesion Society of Japan, vol.22, no.10 (1986) (53) (566) ( Journal of Adhesion Society of Japan), etc.). Since the calculation method does not require a density value, the solubility parameter can be easily calculated. The Fedors theoretical SP value is calculated by the following formula.
SP value = (ΣΔei/ΣΔvi) ^1/2
where ΣΔei is the sum of vaporization energies of atoms and groups, and ΣΔvi=sum of molar volumes.

The hydrazide compound according to the present invention preferably has one or more hydroxyl groups in one molecule. By having one or more hydroxyl groups in one molecule of the hydrazide compound according to the present invention, the obtained sealing agent for liquid crystal display elements is excellent in the effect of achieving both storage stability and curability.

Specific examples of hydrazide compounds according to the present invention include malic acid dihydrazide (SP value 39.7 (J/cm ³ ) ^1/2 ), 2-hydroxypropane-1,2,3-tricarbohydrazide ( SP value 40.5 (J/cm ³ ) ^1/2 ), tartaric acid dihydrazide (SP value 45.9 (J/cm ³ ) ^1/2 ), gluconic acid hydrazide (SP value 48.5 (J/cm ³ ) ^1/2 ) and the like. Among them, at least one selected from the group consisting of 2-hydroxypropane-1,2,3-tricarbohydrazide, tartaric acid dihydrazide, and gluconic acid hydrazide is preferable.

The content of the hydrazide compound according to the present invention in the thermosetting agent is preferably 80 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% or more. Mole % is most preferred.

As for the content of the thermosetting agent, a preferable lower limit is 1 part by weight and a preferable upper limit is 10 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the thermosetting agent is within this range, the obtained sealing agent for liquid crystal display elements is excellent in the effect of achieving both storage stability and curability. A more preferable lower limit to the content of the thermosetting agent is 3 parts by weight, and a more preferable upper limit is 8 parts by weight.

The sealant for liquid crystal display elements of the present invention contains a curable resin.
The curable resin preferably contains an epoxy compound.
Examples of the epoxy compounds include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, 2,2'-diallylbisphenol A type epoxy resin, and 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 type epoxy resin, ortho cresol Novolak type epoxy resin, dicyclopentadiene novolak type epoxy resin, biphenyl novolak type epoxy resin, naphthalenephenol novolac type epoxy resin, glycidylamine type epoxy resin, alkyl polyol type epoxy resin, rubber modified type epoxy resin, glycidyl ester compound, etc. be done.

Commercially available bisphenol A type epoxy resins include, for example, jER828EL, jER1004 (all manufactured by Mitsubishi Chemical Corporation), Epiclon 850 (manufactured by DIC Corporation), and the like.
Examples of commercially available bisphenol F type epoxy resins include jER806 and jER4004 (both manufactured by Mitsubishi Chemical Corporation).
Examples of commercially available bisphenol E type epoxy resins include Epomic R710 (manufactured by Mitsui Chemicals, Inc.).
Examples of commercially available bisphenol S-type epoxy resins include Epiclon EXA1514 (manufactured by DIC Corporation).
Commercially available 2,2′-diallylbisphenol A type epoxy resins include, for example, RE-810NM (manufactured by Nippon Kayaku Co., Ltd.).
Commercially available hydrogenated bisphenol type epoxy resins include, for example, Epiclon EXA7015 (manufactured by DIC Corporation).
Commercially available propylene oxide-added bisphenol A type epoxy resins include, for example, EP-4000S (manufactured by ADEKA).
Commercially available resorcinol-type epoxy resins include, for example, EX-201 (manufactured by Nagase ChemteX Corporation).
Commercially available biphenyl-type epoxy resins include, for example, jER YX-4000H (manufactured by Mitsubishi Chemical Corporation).
Examples of commercially available sulfide-type epoxy resins include YSLV-50TE (manufactured by Nippon Steel Chemical & Materials Co., Ltd.).
Examples of commercially available diphenyl ether type epoxy resins include YSLV-80DE (manufactured by Nippon Steel Chemical & Materials Co., Ltd.).
Commercially available dicyclopentadiene type epoxy resins include, for example, EP-4088S (manufactured by ADEKA).
Examples of commercially available naphthalene-type epoxy resins include Epiclon HP4032 and Epiclon EXA-4700 (both manufactured by DIC Corporation).
Commercially available phenolic novolac epoxy resins include, for example, Epiclon N-770 (manufactured by DIC Corporation).
Commercially available ortho-cresol novolac type epoxy resins include, for example, Epiclon N-670-EXP-S (manufactured by DIC).
Examples of commercially available dicyclopentadiene novolac type epoxy resins include Epiclon HP7200 (manufactured by DIC Corporation).
Commercially available biphenyl novolac type epoxy resins include, for example, NC-3000P (manufactured by Nippon Kayaku Co., Ltd.).
Commercially available naphthalene phenol novolac type epoxy resins include, for example, ESN-165S (manufactured by Nippon Steel Chemical & Materials Co., Ltd.).
Examples of commercially available glycidylamine type epoxy resins include jER630 (manufactured by Mitsubishi Chemical Corporation), Epiclon 430 (manufactured by DIC Corporation), TETRAD-X (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and the like.
Examples of commercially available alkyl polyol type epoxy resins include ZX-1542 (manufactured by Nippon Steel Chemical & Materials Co., Ltd.), Epiclon 726 (manufactured by DIC Corporation), Epolite 80 MFA (manufactured by Kyoeisha Chemical Co., Ltd.), and Denacol EX. -611 (manufactured by Nagase ChemteX Corporation) and the like.
Examples of commercially available rubber-modified epoxy resins include YR-450 and YR-207 (both manufactured by Nippon Steel Chemical & Materials) and Epolead PB (manufactured by Daicel).
Examples of commercially available glycidyl ester compounds include Denacol EX-147 (manufactured by Nagase ChemteX Corporation).
Other commercially available epoxy compounds include YDC-1312, YSLV-80XY, YSLV-90CR (all manufactured by Nippon Steel Chemical & Materials), XAC4151 (manufactured by Asahi Kasei), jER1031, and jER1032. (all manufactured by Mitsubishi Chemical), EXA-7120 (manufactured by DIC), TEPIC (manufactured by Nissan Chemical) and the like.

Partially (meth)acrylic-modified epoxy resins are also suitably used as the epoxy compound.
In this specification, the partially (meth)acrylic-modified epoxy resin is obtained by reacting a partial epoxy group of an epoxy compound having two or more epoxy groups with (meth)acrylic acid. It means a compound having one or more epoxy groups and one or more (meth)acryloyl groups in the molecule.

Examples of commercially available partially (meth)acrylic-modified epoxy resins include UVACURE 1561 and KRM8287 (both manufactured by Daicel Allnex).

A preferable lower limit of the content of the epoxy compound in 100 parts by weight of the curable resin is 5 parts by weight, and a preferable upper limit thereof is 60 parts by weight. When the content of the epoxy compound is within this range, the resulting sealing agent for liquid crystal display elements is excellent in curability and low liquid crystal contamination. A more preferable upper limit of the content of the epoxy compound is 45 parts by weight.

Moreover, the curable resin may contain a (meth)acrylic compound.
Examples of the (meth)acrylic compound include (meth)acrylic acid ester compounds, epoxy (meth)acrylates, and urethane (meth)acrylates. Among them, epoxy (meth)acrylate is preferred. The (meth)acrylic compound preferably has two or more (meth)acryloyl groups in one molecule because of its high reactivity.
In addition, in this specification, the above-mentioned "(meth)acryl" means acryl or methacryl, and the above-mentioned "(meth)acrylic compound" means a compound having a (meth)acryloyl group. Further, the above "(meth)acrylate" means acrylate or methacrylate, and the above "epoxy(meth)acrylate" is a compound obtained by reacting all epoxy groups in an epoxy compound with (meth)acrylic acid. represents

Among the above (meth)acrylic acid ester compounds, monofunctional ones include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate. , t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, iso myristyl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, cyclohexyl ( meth)acrylate, isobornyl (meth)acrylate, bicyclopentenyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-Phenoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethyleneglycol (meth)acrylate, phenoxydiethyleneglycol (meth)acrylate, phenoxypolyethyleneglycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethyl carbi tall (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, imido (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethylhexahydrophthalate, 2-( meth)acryloyloxyethyl 2-hydroxypropyl phthalate, 2-(meth)acryloyloxyethyl phosphate, glycidyl (meth)acrylate and the like.

Among the above (meth)acrylic acid ester compounds, bifunctional ones include, for example, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexane Diol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate (Meth) acrylate, polyethylene glycol di (meth) acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) ) acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, ethylene oxide-added bisphenol F di(meth)acrylate , dimethyloldicyclopentadienyl di(meth)acrylate, ethylene oxide-modified isocyanuric acid di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, polybutadiene diol di(meth)acrylate and the like.

Further, among the above (meth)acrylic acid ester compounds, trifunctional or higher ones include, for example, trimethylolpropane tri(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added trimethylolpropane tri( meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, ethylene oxide-added isocyanuric acid tri(meth)acrylate, glycerin tri(meth)acrylate, propylene oxide-added glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate and the like.

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

As the epoxy compound serving as a raw material for synthesizing the epoxy (meth)acrylate, the same epoxy compound as the curable resin contained in the sealing agent for liquid crystal display elements of the present invention can be used.

Commercially available epoxy (meth)acrylates include, for example, epoxy (meth)acrylate manufactured by Daicel Allnex, epoxy (meth)acrylate manufactured by Shin-Nakamura Chemical Industry, epoxy (meth)acrylate manufactured by Kyoeisha Chemical Co., Ltd. ( meth) acrylate, epoxy (meth) acrylate manufactured by Nagase ChemteX Corporation, and the like.
Examples of epoxy (meth)acrylates manufactured by Daicel Allnex include EBECRYL860, EBECRYL3200, EBECRYL3201, EBECRYL3412, EBECRYL3600, EBECRYL3700, EBECRYL3701, EBECRYL3702, EBECRYL3703, EBECR YL3708, EBECRYL3800, EBECRYL6040, EBECRYL RDX63182 and the like.
Examples of epoxy (meth)acrylates manufactured by Shin-Nakamura Chemical Co., Ltd. include EA-1010, EA-1020, EA-5323, EA-5520, EA-CHD, and EMA-1020.
Examples of the epoxy (meth)acrylate manufactured by Kyoeisha Chemical Co., Ltd. include, for example, Epoxy Ester M-600A, Epoxy Ester 40EM, Epoxy Ester 70PA, Epoxy Ester 200PA, Epoxy Ester 80MFA, Epoxy Ester 3002M, Epoxy Ester 3002A, Epoxy Ester 1600A, Epoxy Ester 3000M, Epoxy Ester 3000A, Epoxy Ester 200EA, Epoxy Ester 400EA and the like.
Examples of epoxy (meth)acrylates manufactured by Nagase ChemteX Co., Ltd. include Denacol acrylate DA-141, Denacol acrylate DA-314, Denacol acrylate DA-911, and the like.

The urethane (meth)acrylate can be obtained, for example, by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group in the presence of a catalytic amount of a tin compound.

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

As the isocyanate compound, a chain-extended isocyanate compound obtained by reacting a polyol with an excess isocyanate compound can also be used.
Examples of the polyol include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, polycaprolactone diol and the like.

Examples of the (meth)acrylic acid derivative having a hydroxyl group include hydroxyalkyl mono(meth)acrylates, dihydric alcohol mono(meth)acrylates, trihydric alcohol mono(meth)acrylates and di(meth)acrylates. , epoxy (meth)acrylate, and the like.
Examples of the hydroxyalkyl mono(meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and the like. mentioned.
Examples of the dihydric alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol.
Examples of the trihydric alcohol include trimethylolethane, trimethylolpropane, glycerin and the like.
Examples of the epoxy (meth)acrylate include bisphenol A type epoxy acrylate.

Examples of commercially available urethane (meth) acrylates include urethane (meth) acrylate manufactured by Toagosei Co., Ltd., urethane (meth) acrylate manufactured by Daicel Allnex, and urethane (meth) acrylate manufactured by Negami Kogyo Co., Ltd. acrylate, urethane (meth)acrylate manufactured by Shin-Nakamura Chemical Co., Ltd., urethane (meth)acrylate manufactured by Kyoeisha Chemical Co., Ltd., and the like.
Examples of the urethane (meth)acrylates manufactured by Toagosei Co., Ltd. include M-1100, M-1200, M-1210 and M-1600.
Examples of the urethane (meth)acrylates manufactured by Daicel Allnex include EBECRYL210, EBECRYL220, EBECRYL230, EBECRYL270, EBECRYL1290, EBECRYL2220, EBECRYL4827, EBECRYL4842, EBECRYL4858, and EBECRYL5. 129, EBECRYL6700, EBECRYL8402, EBECRYL8803, EBECRYL8804, EBECRYL8807, EBECRYL9260, etc. mentioned.
Examples of the urethane (meth)acrylate manufactured by Neagari Kogyo Co., Ltd. include, for example, Artresin UN-330, Artresin SH-500B, Artresin UN-1200TPK, Artresin UN-1255, Artresin UN-3320HB, Artresin UN- 7100, Artresin UN-9000A, Artresin UN-9000H and the like.
The urethane (meth)acrylates manufactured by Shin-Nakamura Chemical Co., Ltd. include, for example, 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 and the like.
Examples of the urethane (meth)acrylate manufactured by Kyoeisha Chemical Co., Ltd. include AH-600, AI-600, AT-600, UA-101I, UA-101T, UA-306H, UA-306I, and UA-306T. be done.

When the curable resin contains the (meth)acrylic compound in addition to the epoxy compound, or when the partially (meth)acryl-modified epoxy compound is contained, the epoxy group in the curable resin and the (meth) It is preferable that the ratio of (meth)acryloyl groups in the total amount of acryloyl groups is 30 mol % or more and 95 mol % or less. When the ratio of the (meth)acryloyl group is within this range, the resulting sealant for liquid crystal display elements has excellent adhesion while suppressing the occurrence of liquid crystal contamination.

From the viewpoint of further suppressing liquid crystal contamination, the curable resin preferably has a hydrogen-bonding unit such as —OH group, —NH— group, or —NH ₂ group.

The preferred lower limit of the SP value of the entire curable resin is 25.0 (J/cm ³ ) ^1/2 and the preferred upper limit is 50.0 (J/cm ³ ) ^1/2 . When the SP value of the curable resin as a whole is within this range, the obtained sealing compound for liquid crystal display elements is excellent in low liquid crystal contamination and is excellent in the effect of suppressing display defects of liquid crystal display elements.
In addition, when the curable resin is composed of a plurality of types of constituent components, the SP value of the entire curable resin means the average value of the SP values according to the weight fraction of each curable resin constituent component.

The sealing compound for liquid crystal display elements of the present invention preferably contains a radical polymerization initiator.
Examples of the radical polymerization initiator include photoradical polymerization initiators that generate radicals by light irradiation and thermal radical polymerization initiators that generate radicals by heating.

Examples of the radical photopolymerization initiator include benzophenone-based compounds, acetophenone-based compounds, acylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, and thioxanthone.

Specific examples of the photoradical polymerization initiator include 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino )-2-((4-methylphenyl)methyl)-1-(4-(4-morpholinyl)phenyl)-1-butanone, 2,2-dimethoxy-2-phenylacetophenone, bis(2,4,6- trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-2 -methyl-1-propane-1-one, 1-(4-(phenylthio)phenyl)-1,2-octanedione 2-(O-benzoyloxime), 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and the like.
The radical photopolymerization initiators may be used alone, or two or more of them may be used in combination.

Examples of the thermal radical polymerization initiator include those composed of azo compounds, organic peroxides, and the like. Among them, from the viewpoint of suppressing liquid crystal contamination, an initiator composed of an azo compound (hereinafter also referred to as an "azo initiator") is preferable, and an initiator composed of a polymer azo compound (hereinafter referred to as a "polymer azo initiator") is preferable. Also referred to as "initiator") is more preferred.
The thermal radical polymerization initiators may be used alone, or two or more of them may be used in combination.
As used herein, the term "polymeric azo compound" means a compound having an azo group, generating a radical capable of curing a (meth)acryloyl group by heat, and having a number average molecular weight of 300 or more. do.

A preferable lower limit of the number average molecular weight of the above high-molecular azo compound is 1,000, and a preferable upper limit thereof is 300,000. When the number-average molecular weight of the high-molecular-weight azo compound is within this range, it can be easily mixed with the curable resin while preventing adverse effects on the liquid crystal. The lower limit of the number average molecular weight of the high-molecular azo compound is more preferably 5,000, the upper limit is 100,000, the lower limit is still more preferably 10,000, and the upper limit is still more preferably 90,000.
In addition, in this specification, the said number average molecular weight is a value which performs measurement using a tetrahydrofuran as a solvent by a gel permeation chromatography (GPC), and is calculated|required by polystyrene conversion. Examples of a column for measuring the number average molecular weight by GPC in terms of polystyrene include Shodex LF-804 (manufactured by Showa Denko KK).

Examples of the polymer azo compound include those having a structure in which a plurality of units such as polyalkylene oxide and polydimethylsiloxane are bonded via an azo group.
As the polymer azo compound having a structure in which a plurality of units such as polyalkylene oxide are bonded via the azo group, one having a polyethylene oxide structure is preferable.
Specific examples of the high-molecular azo compound include polycondensates of 4,4′-azobis(4-cyanopentanoic acid) and polyalkylene glycol, and 4,4′-azobis(4-cyanopentanoic acid). and a polycondensate of polydimethylsiloxane having a terminal amino group.
Commercially available polymeric azo initiators include, for example, VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001 (all manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) and the like. mentioned.
Examples of non-polymeric azo initiators include V-65 and V-501 (both manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.).

Examples of the organic peroxides include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, peroxyesters, diacyl peroxides and peroxydicarbonates.

The content of the radical polymerization initiator has a preferred lower limit of 0.1 parts by weight and a preferred upper limit of 30 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the radical polymerization initiator is within this range, the resulting sealing compound for liquid crystal display elements is excellent in storage stability and curability while suppressing liquid crystal contamination. The more preferable lower limit of the content of the radical polymerization initiator is 1 part by weight, the more preferable upper limit is 10 parts by weight, and the more preferable upper limit is 5 parts by weight.

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

An inorganic filler or an organic filler can be used as the filler.
Examples of inorganic fillers include silica, talc, glass beads, asbestos, gypsum, diatomaceous earth, smectite, bentonite, montmorillonite, sericite, activated clay, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, and titanium oxide. , calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum nitride, silicon nitride, barium sulfate, calcium silicate and the like.
Examples of the organic filler include polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, acrylic polymer fine particles, and the like.
The above fillers may be used alone, or two or more of them may be used in combination.

A preferable lower limit of the content of the filler in 100 parts by weight of the sealing compound for liquid crystal display elements of the present invention is 10 parts by weight, and a preferable upper limit thereof is 70 parts by weight. When the content of the filler is within this range, the effect of improving adhesiveness, etc., is excellent without deteriorating coating properties, etc. A more preferable lower limit of the filler content is 20 parts by weight, and a more preferable upper limit thereof is 60 parts by weight.

The sealing compound for liquid crystal display elements of the present invention may contain a silane coupling agent. The silane coupling agent mainly serves as an adhesion assistant for good adhesion between the sealing agent and the substrate.

As the silane coupling agent, for example, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane and the like are preferably used. These are excellent in the effect of improving the adhesiveness to a substrate or the like, and can suppress the outflow of the curable resin into the liquid crystal by chemically bonding with the curable resin.
The silane coupling agents may be used alone, or two or more of them may be used in combination.

A preferable lower limit of the content of the silane coupling agent in 100 parts by weight of the liquid crystal display element sealing compound of the present invention is 0.1 parts by weight, and a preferable upper limit thereof is 10 parts by weight. When the content of the silane coupling agent is within this range, the effect of improving adhesion while suppressing the occurrence of liquid crystal contamination is more excellent. A more preferable lower limit to the content of the silane coupling agent is 0.3 parts by weight, and a more preferable upper limit is 5 parts by weight.

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

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 preferable.

Titanium black is a substance that exhibits a higher transmittance for light in the vicinity of the ultraviolet region, particularly light with a wavelength of 370 nm or more and 450 nm or less, than average transmittance for light with a wavelength of 300 nm or more and 800 nm or less. That is, the titanium black has a property of imparting a light-shielding property to the sealing agent for a liquid crystal display element of the present invention by sufficiently shielding light of wavelengths in the visible light region, while transmitting light of wavelengths in the vicinity of the ultraviolet region. It is a light-shielding agent with Therefore, by using, as the photoradical polymerization initiator, a reaction that can be initiated by light of a wavelength (370 nm or more and 450 nm or less) at which the transmittance of the titanium black increases, the sealant for a liquid crystal display element of the present invention can be obtained. Photocurability can be further increased. On the other hand, as the light shielding agent contained in the sealant for liquid crystal display elements of the present invention, a highly insulating substance is preferable, and titanium black is also suitable as the highly insulating light shielding agent.
The above titanium black preferably has an optical density (OD value) per 1 μm of 3 or more, more preferably 4 or more. The higher the light shielding property of the titanium black, the better. Although there is no particular upper limit for the OD value of the titanium black, it is usually 5 or less.

The above titanium black exerts a sufficient effect even if it is not surface-treated, but it can also be used when the surface is treated with an organic component such as a coupling agent, silicon oxide, titanium oxide, germanium oxide, aluminum oxide, oxide. Surface-treated titanium blacks, such as those coated with inorganic components such as zirconium and magnesium oxide, can also be used. Among them, those treated with an organic component are preferable because they can further improve the insulating properties.
Further, the liquid crystal display device manufactured using the sealing agent for a liquid crystal display device of the present invention in which the above-described titanium black is blended as a light shielding agent has sufficient light shielding properties, so that light does not leak out and has high contrast. A liquid crystal display element having excellent image display quality can be realized.

Examples of commercially available titanium blacks include titanium black manufactured by Mitsubishi Materials Corporation, titanium black manufactured by Ako Kasei Co., Ltd., and the like.
Examples of titanium black manufactured by Mitsubishi Materials Corporation include 12S, 13M, 13M-C, 13R-N, and 14M-C.
Examples of the titanium black manufactured by Ako Kasei Co., Ltd. include Tilak D and the like.

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

The primary particle size of the light shielding agent is not particularly limited as long as it is equal to or smaller 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. When the primary particle size of the light shielding agent is within this range, the obtained sealing agent for liquid crystal display elements can be made more excellent in light shielding properties without deteriorating the applicability or the like. The primary particle size of the light shielding agent has a more preferable lower limit of 5 nm, a more preferable upper limit of 200 nm, a still more preferable lower limit of 10 nm, and a still more preferable upper limit of 100 nm.
The primary particle size of the light shielding agent can be measured by dispersing the light shielding agent in a solvent (water, organic solvent, etc.) using NICOMP 380ZLS (manufactured by PARTICLE SIZING SYSTEMS).

A preferable lower limit of the content of the light shielding agent in 100 parts by weight of the liquid crystal display element sealing compound of the present invention is 5 parts by weight, and a preferable upper limit thereof is 80 parts by weight. When the content of the light-shielding agent is within this range, the obtained sealant for liquid crystal display elements exhibits excellent light-shielding properties without significantly deteriorating the adhesiveness, strength after curing, and drawability. be able to. A more preferable lower limit of the content of the light shielding agent is 10 parts by weight, a more preferable upper limit is 70 parts by weight, a still more preferable lower limit is 30 parts by weight, and a further preferable upper limit is 60 parts by weight.

The sealant for liquid crystal display elements of the present invention may further contain, if necessary, stress relaxation agents, reactive diluents, thixotropic agents, spacers, curing accelerators, antifoaming agents, leveling agents, polymerization inhibitors, and the like. It may contain an agent.

As a method for producing the sealing compound for a liquid crystal display element of the present invention, for example, a mixer is used to mix a curable resin, a thermosetting agent, and a radical polymerization initiator or the like added as necessary. methods and the like. Examples of the mixer include a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, and three rolls.

By blending the conductive fine particles into the liquid crystal display element sealant of the present invention, a vertically conducting material can be produced. A vertically conductive material containing such a sealant for a liquid crystal display element of the present invention and conductive fine particles is also one aspect of the present invention.

As the conductive fine particles, for example, metal balls, resin fine particles having a conductive metal layer formed on the surface thereof, and the like can be used. Among them, those having a conductive metal layer formed on the surface of the resin fine particles are preferable because the excellent elasticity of the resin fine particles enables conductive connection without damaging the transparent substrate or the like.

A liquid crystal display element using the sealant for a liquid crystal display element of the present invention or the vertically conductive material of the present invention is also one aspect of the present invention.
Since the sealant for a liquid crystal display device of the present invention has low compatibility with liquid crystal molecules having polar groups, the liquid crystal display device of the present invention uses a highly polar liquid crystal containing liquid crystal molecules having polar groups. In this case, the effect of suppressing display defects is more pronounced than with conventional sealants. That is, the liquid crystal display element of the present invention preferably uses a highly polar liquid crystal containing liquid crystal molecules having a polar group.
Polar groups of the liquid crystal molecules include, for example, fluoro groups, chloro groups, and cyano groups.

Further, the sealant for a liquid crystal display element of the present invention uses a liquid crystal having an SP value of 22.0 (J/cm ³ ) ^1/2 or more and 50.0 (J/cm ³ ) ^1/2 or less. , the effect of suppressing display defects is more pronounced than with conventional sealants.
In addition, when the liquid crystal is composed of a plurality of types of liquid crystal molecules, the SP value of the liquid crystal means the average value of the SP values according to the weight fraction of each liquid crystal molecule.

As the liquid crystal display element of the present invention, a liquid crystal display element having a narrow frame design is preferable. Specifically, it is preferable that the width of the frame portion around the liquid crystal display section is 2 mm or less.
Moreover, it is preferable that the coating width of the sealant for a liquid crystal display element of the present invention when manufacturing the liquid crystal display element of the present invention is 1 mm or less.

The sealing compound for liquid crystal display elements of the present invention can be suitably used for manufacturing liquid crystal display elements by the liquid crystal dropping method.
Examples of the method for manufacturing the liquid crystal display element of the present invention by the liquid crystal dropping method include the following methods.
First, a step of forming a frame-shaped seal pattern on a substrate by screen printing, applying with a dispenser, or the like the sealant for a liquid crystal display element of the present invention is performed. Next, a step of applying liquid crystal microdroplets to the entire surface of the frame of the seal pattern while the sealant for a liquid crystal display element of the present invention is uncured, and immediately superimposing another substrate is performed. After that, a liquid crystal display element can be obtained by a method of performing a step of heating and curing the sealant. Moreover, before the step of heating and curing the sealant, a step of temporarily curing the sealant by irradiating the seal pattern portion with light such as ultraviolet rays may be performed.

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal display elements which is excellent in storage stability and curability, and can suppress generation|occurrence|production of a display defect can be provided, even when it is used for a thin liquid crystal display element. Further, according to the present invention, it is possible to provide a vertically conductive material and a liquid crystal display element using the sealant for a liquid crystal display element.

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.

(Examples 2 to 4, Reference Examples 1, 5 to 7, Comparative Examples 1 to 3)
According to the compounding ratio shown in Table 1, each material was mixed using a planetary stirrer (manufactured by THINKY Co., Ltd., "Awatori Mixer"), and then further mixed using a three-roll roll. 2 to 4, Reference Examples 1, 5 to 7, and Comparative Examples 1 to 3 were prepared.

<Evaluation>
The sealants for liquid crystal display elements obtained in Examples , Reference Examples, and Comparative Examples were evaluated as follows. Table 1 shows the results.

(Storage stability)
For each liquid crystal display element sealant obtained in Examples , Reference Examples, and Comparative Examples, the initial viscosity immediately after production and the viscosity after storage in an atmosphere of 25 ° C. and 50% RH for 48 hours after production. was measured. (Viscosity after storage) / (initial viscosity) is defined as the viscosity increase rate, and "○" indicates that the viscosity increase rate is less than 1.2, and "△" indicates that the viscosity increase rate is 1.2 or more and less than 1.3. , 1.3 or more, the storage stability was evaluated as "x".
The viscosity of the sealing agent was measured using an E-type viscometer (“DV-III” manufactured by BROOK FIELD) at 25° C. and a rotational speed of 1.0 rpm.

(Curability)
Each of the liquid crystal display element sealants obtained in Examples , Reference Examples, and Comparative Examples was spotted onto one of two transparent substrates, and the other transparent substrate was placed on top of the other. UV rays of 100 mW/cm ² were applied for 30 seconds. Then, it was heated at 120° C. for 1 hour to thermally cure the liquid crystal display element sealant. The transparent substrate was peeled off, and the cured product remaining on the transparent substrate was measured using an infrared spectrometer (manufactured by Agilent Technologies, "UMA600"). From the results, the curing rate was calculated by the following formula.
Curing rate (%) = 100 x (1-(peak area of epoxy group after curing)/(peak area of epoxy group before curing))
Curability was evaluated by assigning “◯” when the curing rate was 90% or more, “Δ” when the curing rate was 70% or more and less than 90%, and “X” when the curing rate was less than 70%.

(Display performance of liquid crystal display element)
One of the two rubbed substrates with alignment films and transparent electrodes was coated with the liquid crystal display element sealants obtained in Examples , Reference Examples, and Comparative Examples with a dispenser so as to draw a square frame. A seal pattern was formed. A sealant for a liquid crystal display element was dotted on the inner side of the formed seal pattern.
Subsequently, a liquid crystal containing a liquid crystal molecule having a cyano group as a polar group (manufactured by Tokyo Chemical Industry Co., Ltd., "4-pentyl-4-biphenylcarbonitrile", SP value 22.4 (J/cm ³ ) ^1/2 ). A microdroplet was applied dropwise to the entire frame of the sealant on the substrate with the transparent electrode, and the other substrate was superimposed in a vacuum. After releasing the vacuum, the outer frame seal portion was irradiated with ultraviolet rays of 100 mW/cm ² for 30 seconds using a metal halide lamp. At this time, the spotted liquid crystal display element sealing agent was masked so as not to be irradiated with ultraviolet rays. After that, liquid crystal annealing was performed at 120° C. for 1 hour to thermally cure the liquid crystal display element sealant to obtain a liquid crystal display element.
Regarding the liquid crystal display element immediately after the production, disturbance of the liquid crystal alignment around the spotted liquid crystal display element sealing compound was visually confirmed. Disturbance in liquid crystal alignment was determined by color unevenness and bright spots in a range of less than 500 μm from the sealing edge of the liquid crystal display element.
In the range of less than 500 μm from the sealing edge of the liquid crystal display element, “○” when there is no color unevenness or bright spots at all, “△” when color unevenness and / or bright spots are slightly observed, color The display performance of the liquid crystal display element (immediately after production) was evaluated with "x" when there were considerable unevenness and/or bright spots.
In addition, after 24 hours at 25° C. from the production of the liquid crystal display element, disturbance of the liquid crystal alignment around the spotted liquid crystal display element sealant was visually confirmed in an energized state. Disturbance of liquid crystal alignment was judged by color unevenness and bright spots in the range of less than 500 μm and 500 μm or more from the sealing edge of the peripheral portion of the liquid crystal display element.
In the range of less than 500 μm from the seal, "◎" when there is no color unevenness and bright spots at all, "○" when color unevenness and / or bright spots are slightly observed, color unevenness and / or bright spots The display performance of the liquid crystal display element (24 hours after production) is evaluated as "△" when there is considerable color unevenness and bright spots in the range of 500 μm or more from the seal. bottom.

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal display elements which is excellent in storage stability and curability, and can suppress generation|occurrence|production of a display defect can be provided, even when it is used for a thin liquid crystal display element. Further, according to the present invention, it is possible to provide a vertically conductive material and a liquid crystal display element using the sealant for a liquid crystal display element.

Claims (4)

A sealant for a liquid crystal display element containing a curable resin and a thermosetting agent, and a liquid crystal display element using a liquid crystal,
The thermosetting agent contains a hydrazide compound having a solubility parameter of 40.0 (J/cm ³ ) ^1/2 or more and 60.0 (J/cm ³ ) ^1/2 or less,
The liquid crystal has a solubility parameter of 22.0 (J/cm ³ ) ^1/2 or more and 50.0 (J/cm ³ ) ^1/2 or less.
A liquid crystal display element characterized by : The hydrazide compound has a solubility parameter of 50.0 (J/cm ³ ) ^1/2 2. The liquid crystal display device according to claim 1, wherein: The solubility parameter of the entire curable resin is 25.0 (J/cm ³ ) ^1/2 50.0 (J/cm ³ ) ^1/2 3. The liquid crystal display device according to claim 1 or 2, wherein: The curable resin contains an epoxy compound,
4. The liquid crystal display element according to claim 1, wherein the content of said epoxy compound in 100 parts by weight of said curable resin is 5 parts by weight or more and 60 parts by weight or less.