JP5820184B2 - Sealant for liquid crystal display element, vertical conduction material, and liquid crystal display element - Google Patents

Description

The present invention relates to a sealing agent for liquid crystal display elements that can suppress the occurrence of afterimages in liquid crystal display elements. Moreover, this invention relates to the vertical conduction material and liquid crystal display element which are manufactured using this sealing compound for liquid crystal display elements.

In recent years, a method for manufacturing a liquid crystal display element such as a liquid crystal display cell has been disclosed in, for example, Patent Document 1 and Patent Document 2 from the conventional vacuum injection method from the viewpoint of shortening tact time and optimizing the amount of liquid crystal used. Such a photocurable resin, a photopolymerization initiator, a thermosetting resin, and a liquid crystal dropping method called a dropping method using a light and heat combined curing type sealant containing a thermosetting agent are being replaced.

In the dropping method, first, a rectangular seal pattern is formed on one of two transparent substrates with electrodes by dispensing. Next, a liquid crystal micro-droplet is dropped on the entire surface of the transparent substrate frame with the sealant being uncured, and the other transparent substrate is immediately overlaid, and the seal portion is irradiated with light such as ultraviolet rays to perform temporary curing. . Thereafter, heating is performed at the time of liquid crystal annealing to perform main curing, and a liquid crystal display element is manufactured. If the substrates are bonded together under reduced pressure, a liquid crystal display element can be manufactured with extremely high efficiency, and this dripping method is currently the mainstream method for manufacturing liquid crystal display elements.
However, when a voltage is applied for a long time to a liquid crystal display element manufactured by a dropping method using a conventional sealant, an afterimage may occur in the liquid crystal display element due to “burn-in” in which the liquid crystal undergoes abnormal alignment.

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

An object of this invention is to provide the sealing compound for liquid crystal display elements which can suppress generation | occurrence | production of the afterimage in a liquid crystal display element. Moreover, an object of this invention is to provide the vertical conduction material and liquid crystal display element which are manufactured using this sealing compound for liquid crystal display elements.

The present invention is a liquid crystal dropping method sealing agent containing a curable resin, a photopolymerization initiator, a thermal polymerization initiator, and a thermosetting agent, wherein the content of the photopolymerization initiator is the curable resin. It is a sealing compound for liquid crystal dropping method which is 0.01 weight part or more and less than 0.5 weight part with respect to 100 weight part of resin.
The present invention is described in detail below.

The present inventor has found that the cause of “burn-in” in the liquid crystal display element is the photopolymerization initiator used for photocuring the curable resin. Conventionally, the blending amount of the photopolymerization initiator blended in the sealant is usually 1 part by weight or more with respect to 100 parts by weight of the curable resin.
Therefore, the present inventor obtains a sealing agent for a liquid crystal display element that can suppress the occurrence of an afterimage in the liquid crystal display element by using a specific photopolymerization initiator and reducing the content of the specific photopolymerization initiator from the normal amount. As a result, the present invention has been completed.

The sealing agent for liquid crystal display elements of this invention contains a photoinitiator. By containing the photopolymerization initiator, photocurability can be imparted to the obtained sealing agent for liquid crystal display elements.

The photopolymerization initiator has an extinction coefficient at a wavelength of 405 nm measured in a solvent of 50 mL / g · cm or more. When the extinction coefficient at a wavelength of 405 nm is less than 50 mL / g · cm, the sealant is insufficiently cured, causing liquid crystal contamination. A more preferable lower limit of the extinction coefficient is 70 mL / g · cm. The higher the extinction coefficient is, the higher the reactivity tends to be, so there is no particular upper limit.
Examples of the solvent used when measuring the extinction coefficient of the photopolymerization initiator include acetonitrile and methanol.

The photopolymerization initiator is not particularly limited as long as the absorption coefficient at a wavelength of 405 nm is 50 mL / g · cm or more. For example, a benzophenone compound, an acetophenone compound, an acylphosphine oxide compound, a titanocene compound, an oxime Examples include ester compounds, benzoin ether compounds, benzyl, thioxanthone, and the like. Among them, 1,2-octanedione 1- [4- (phenylthio) -2 has an absorption band at 405 nm, is excellent in reactivity, and can sufficiently cure the sealant even if the blending amount is small. -(O-benzoyloxime)], 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

As those commercially available of the photopolymerization initiator, for example, I RGACURE 369, IRGACURE 379, I RGACURE 819, I RGACURE OXE01, DAROCUR TPO ( all manufactured by BASF Japan Ltd.), benzoin methyl ether, benzoin ethyl ether And benzoin isopropyl ether (all of which are manufactured by Tokyo Chemical Industry Co., Ltd.). Among these, IRGACURE OXE01 and DAROCUR TPO are preferable because they are particularly excellent in reactivity and can sufficiently cure the sealant even if the blending amount is small.

The content of the photopolymerization initiator is less than 1 part by weight with respect to 100 parts by weight of the curable resin. When the content of the photopolymerization initiator is 1 part by weight or more, the display quality of the obtained liquid crystal display element is deteriorated and an afterimage is generated. The content of the photopolymerization initiator is preferably less than 0.7 parts by weight, and more preferably less than 0.5 parts by weight.
Moreover, the minimum with preferable content of the said photoinitiator is 0.01 weight part with respect to 100 weight part of said curable resins. If the content of the photopolymerization initiator is less than 0.01 parts by weight, the photopolymerization may not proceed sufficiently or the reaction may be too slow. The minimum with more preferable content of the said photoinitiator is 0.1 weight part.

The sealing agent for liquid crystal display elements of this invention contains curable resin.
The curable resin preferably contains a resin having a (meth) acryloyloxy group.
The resin having the (meth) acryloyloxy group preferably contains an epoxy (meth) acrylate.
In addition, in this specification, the said (meth) acryloyloxy group means an acryloyloxy group or a methacryloyloxy group, and (meth) acrylate means an acrylate or a methacrylate. Moreover, in this specification, the said epoxy (meth) acrylate represents the compound which made all the epoxy groups in an epoxy resin react with (meth) acrylic acid.

The epoxy (meth) acrylate is not particularly limited, and examples thereof include those obtained by reacting (meth) acrylic acid and an epoxy resin in the presence of a basic catalyst according to a conventional method.
In addition, in this specification, (meth) acryl means acryl or methacryl.

The epoxy resin used as a raw material for synthesizing the epoxy (meth) acrylate is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, 2,2′-diallylbisphenol A Type epoxy resin, hydrogenated bisphenol type epoxy resin, propylene oxide added bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy Resin, phenol novolac epoxy resin, orthocresol novolac epoxy resin, dicyclopentadiene novolac epoxy resin, biphenyl novolac epoxy resin Naphthalene phenol novolac-type epoxy resin, glycidyl amine type epoxy resin, alkyl polyol type epoxy resin, rubber modified epoxy resin, glycidyl ester compounds, bisphenol A type episulfide resins.

Examples of commercially available bisphenol A type epoxy resins include Epicoat 828EL, Epicoat 1001, Epicoat 1004 (all manufactured by Mitsubishi Chemical Corporation), Epicron 850-S (manufactured by DIC Corporation), and the like.
As what is marketed among the said bisphenol F type epoxy resins, Epicoat 806, Epicoat 4004 (all are Mitsubishi Chemical Corporation make) etc. are mentioned, for example.
As what is marketed among the said bisphenol S-type epoxy resins, Epicron EXA1514 (made by DIC Corporation) etc. are mentioned, for example.
As what is marketed among the said 2,2'- diallyl bisphenol A type epoxy resins, RE-810NM (made by Nippon Kayaku Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said hydrogenated bisphenol type | mold epoxy resins, Epicron EXA7015 (made by DIC Corporation) etc. are mentioned, for example.
As what is marketed among the said propylene oxide addition bisphenol A type epoxy resins, EP-4000S (made by ADEKA) etc. are mentioned, for example.
As what is marketed among the said resorcinol type epoxy resins, EX-201 (made by Nagase ChemteX Corporation) etc. are mentioned, for example.
As what is marketed among the said biphenyl type epoxy resins, Epicoat YX-4000H (made by Mitsubishi Chemical Corporation) etc. are mentioned, for example.
As what is marketed among the said sulfide type epoxy resins, YSLV-50TE (made by Nippon Steel Chemical Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said diphenyl ether type epoxy resins, YSLV-80DE (made by Nippon Steel Chemical Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said dicyclopentadiene type epoxy resins, EP-4088S (made by ADEKA) etc. are mentioned, for example.
As what is marketed among the said naphthalene type | mold epoxy resins, Epicron HP4032, Epicron EXA-4700 (all are the products made from DIC) etc. are mentioned, for example.
As what is marketed among the said phenol novolak-type epoxy resins, Epicron N-770 (made by DIC Corporation) etc. are mentioned, for example.
As what is marketed among the said ortho cresol novolak-type epoxy resins, Epicron N-670-EXP-S (made by DIC) etc. are mentioned, for example.
As what is marketed among the said dicyclopentadiene novolak-type epoxy resins, epiclone HP7200 (made by DIC) etc. are mentioned, for example.
As what is marketed among the said biphenyl novolak-type epoxy resins, NC-3000P (made by Nippon Kayaku Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said naphthalene phenol novolak-type epoxy resins, ESN-165S (made by Nippon Steel Chemical Co., Ltd.) etc. are mentioned, for example.
As what is marketed among the said glycidylamine type epoxy resins, Epicoat 630 (made by Mitsubishi Chemical Corporation), Epicron 430 (made by DIC Corporation), TETRAD-X (made by Mitsubishi Gas Chemical Co., Inc.) etc. are mentioned, for example.
Examples of commercially available alkyl polyol type epoxy resins include ZX-1542 (manufactured by Nippon Steel Chemical Co., Ltd.), Epicron 726 (manufactured by DIC Corporation), Epolite 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.), Denacol EX- 611 (manufactured by Nagase ChemteX Corporation).
Examples of commercially available rubber-modified epoxy resins include YR-450, YR-207 (all manufactured by Nippon Steel Chemical Co., Ltd.), Epolide PB (manufactured by Daicel Chemical Industries, Ltd.), and the like.
As what is marketed among the said glycidyl ester compounds, Denacol EX-147 (made by Nagase ChemteX Corporation) etc. is mentioned, for example.
As what is marketed among the said bisphenol A type | mold episulfide resin, Epicoat YL-7000 (made by Mitsubishi Chemical Corporation) etc. are mentioned, for example.
Other commercially available epoxy resins include, for example, YDC-1312, YSLV-80XY, YSLV-90CR (all manufactured by Nippon Steel Chemical Co., Ltd.), XAC4151 (manufactured by Asahi Kasei Co., Ltd.), Epicoat 1031, and Epicoat. 1032 (all manufactured by Mitsubishi Chemical Corporation), EXA-7120 (manufactured by DIC Corporation), TEPIC (manufactured by Nissan Chemical Industries, Ltd.) and the like.

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

Examples of commercially available epoxy (meth) acrylates include EBECRYL860, EBECRYL3200, EBECRYL3201, EBECRYL3412, EBECRYL3600, EBECRYL3700, EBECRYL3701, EBECRYL3702, EBECRYL3703, EA-1010, EA-1020, EA-5323, EA-5520, EA-CHD, EMA-1020 (all manufactured by Shin-Nakamura Chemical Co., Ltd.), epoxy ester M-600A, epoxy ester 40EM, epoxy ester 70PA, epoxy ester 200 PA, epoxy ester 80 MFA, Poxy ester 3002M, Epoxy ester 3002A, Epoxy ester 1600A, Epoxy ester 3000M, Epoxy ester 3000A, Epoxy ester 200EA, Epoxy ester 400EA (all manufactured by Kyoeisha Chemical Co., Ltd.), Denacol acrylate DA-141, Denacol acrylate DA-314, Denacol acrylate DA-911 (all manufactured by Nagase ChemteX Corporation) and the like.

Examples of the resin having a (meth) acryloyloxy group other than the epoxy (meth) acrylate include an ester compound obtained by reacting a compound having a hydroxyl group with (meth) acrylic acid, and a hydroxyl group in the isocyanate (meth). Examples thereof include urethane (meth) acrylate obtained by reacting an acrylic acid derivative.

The ester compound obtained by reacting the (meth) acrylic acid with a compound having a hydroxyl group is not particularly limited, and examples of the monofunctional ester compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meta ) Acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) ) Acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, 2-ethoxyethyl (meth) acrylate Tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) Acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, imide (meth) Acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, Rohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isononyl (meth) acrylate, isomyristyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) ) Acrylate, bicyclopentenyl (meth) acrylate, isodecyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyl Roxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl 2-hydroxypropyl phthalate, glycidyl (meth) acrylate, 2- (meth) acryloyloxyethyl phosphate, etc. It is done.

Bifunctional ester compounds include, for example, 1,4-butanediol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9 -Nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, dipropylene glycol di (meth) Acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate , Propylene oxide-added bisphenol A di (meth) acrylate, ethylene oxide-added bisphenol A di (meth) acrylate, ethylene oxide-added bisphenol F di (meth) acrylate, dimethylol dicyclopentadienyl di (meth) acrylate, 1,3-butylene Glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide modified isocyanuric acid di (meth) acrylate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, carbonate diol di (meth) Acrylate, polyether diol di (meth) acrylate, polyester diol di (meth) acrylate, polycaprolactone diol di (meth) acrylate, polybutadiene Diol di (meth) acrylate.

The trifunctional or higher functional ester compounds include, for example, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, propylene oxide-added trimethylolpropane tri (meth) acrylate, and ethylene oxide-added trimethylolpropane tri (meth). Acrylate, caprolactone-modified trimethylolpropane tri (meth) acrylate, ethylene oxide-added isocyanuric acid tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, Pentaerythritol tetra (meth) acrylate, glycerin tri (meth) acrylate, propylene oxide-added glyce Entries (meth) acrylate, tris (meth) acryloyloxyethyl phosphate, and the like.

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

Isocyanate that is a raw material of urethane (meth) acrylate obtained by reacting a hydroxyl group-containing (meth) acrylic acid derivative with the isocyanate is not particularly limited. For example, isophorone diisocyanate, 2,4-tolylene diisocyanate, 2, 6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4′-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene Range Iocyanate (XDI), Hydrogenated XDI, Lysine Diisocyanate, Triphenylmethane Triisocyanate, Tris (Isocyanate Phenyl) Thioff Sufeto, tetramethyl xylene diisocyanate, 1,6,10- undecene country isocyanate.

Moreover, the isocyanate used as the raw material of the urethane (meth) acrylate obtained by making the said isocyanate react with the (meth) acrylic acid derivative which has a hydroxyl group is not specifically limited, For example, ethylene glycol, glycerol, sorbitol, a trimethylol propane, Chain-extended isocyanate compounds obtained by reaction of polyols such as (poly) propylene glycol, carbonate diol, polyether diol, polyester diol, polycaprolactone diol and excess isocyanate can also be used.

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

Examples of commercially available urethane (meth) acrylates include M-1100, M-1200, M-1210, and M-1600 (all manufactured by Toagosei Co., Ltd.), Evekril 230, Evekril 270, and Evekril 4858. , Evekril 8402, Evekrill 8804, Evekrill 8803, Evekrill 8807, Evekrill 9260, Evekrill 1290, Evekril 5129, Evekril 4842, Evekril 4827, Evekril 6700, Evekril 220, Evekyle Rine Tech Co., Ltd. UN-9000H, Art Resin UN-9000A, Art Resin UN-7100, Art Resin UN-1255, Art Resin UN-330, Art Resin UN-332 HB, Art Resin UN-1200TPK, Art Resin SH-500B (all manufactured by Negami Kogyo Co., Ltd.), U-122P, U-108A, U-340P, U-4HA, U-6HA, U-324A, U-15HA, UA-5201P, UA-W2A, U-1084A, U-6LPA, U-2HA, U-2PHA, UA-4100, UA-7100, UA-4200, UA-4400, UA-340P, U-3HA, UA- 7200, U-2061BA, U-10H, U-122A, U-340A, U-108, U-6H, UA-4000 (all manufactured by Shin-Nakamura Chemical Co., Ltd.), AH-600, AT-600, UA- 306H, AI-600, UA-101T, UA-101I, UA-306T, UA-306I (all manufactured by Kyoeisha Chemical Co., Ltd.) It is.

The resin having the (meth) acryloyloxy group preferably has a hydrogen bonding unit such as —OH group, —NH— group, and —NH ₂ group from the viewpoint of suppressing adverse effects on the liquid crystal.
In addition, the resin having the (meth) acryloyloxy group is preferably one having 2 to 3 (meth) acryloyloxy groups in the molecule because of high reactivity.

The curable resin preferably further contains a resin having an epoxy group for the purpose of improving the adhesiveness of the obtained sealing agent for liquid crystal display elements. The resin having the epoxy group is not particularly limited, and examples thereof include an epoxy resin that is a raw material for synthesizing the epoxy (meth) acrylate and a partial (meth) acryl-modified epoxy resin.
In the present specification, the partial (meth) acryl-modified epoxy resin means a resin having one or more epoxy groups and (meth) acryloyloxy groups in one molecule, for example, two or more epoxy resins. It can be obtained by reacting an epoxy group of a part of the resin having a group with (meth) acrylic acid.

The partial (meth) acryl-modified epoxy resin can be obtained, for example, by reacting an epoxy resin and (meth) acrylic acid in the presence of a basic catalyst according to a conventional method. Specifically, for example, 190 g of phenol novolac type epoxy resin N-770 (manufactured by DIC) is dissolved in 500 mL of toluene, 0.1 g of triphenylphosphine is added to this solution to obtain a uniform solution, and acrylic acid is added to this solution. 35 g of the mixture was added dropwise under reflux stirring for 2 hours, followed by further refluxing stirring for 6 hours. Next, by removing toluene, 50 mol% of the epoxy group reacted with (meth) acrylic acid, partially acryl-modified phenol novolak. Type epoxy resin can be obtained (in this case 50% partially acrylated).

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

When the resin having the (meth) acryloyloxy group and the resin having the epoxy group are blended as the curable resin, the ratio of the (meth) acryloyloxy group and the epoxy group of the curable resin is a molar ratio. It is preferable to blend a resin having a (meth) acryloyloxy group and a resin having an epoxy group so as to be 50:50 to 95: 5. When the ratio of the (meth) acryloyloxy group is less than 50%, a large amount of uncured epoxy resin component is present even when the polymerization is completed, and the liquid crystal may be contaminated. When the ratio of the (meth) acryloyloxy group exceeds 95%, the resulting sealant may be inferior in adhesiveness.

The sealing agent for liquid crystal display elements of this invention contains a thermosetting agent.
The said thermosetting agent is not specifically limited, For example, organic acid hydrazide, an imidazole derivative, an amine compound, a polyhydric phenol type compound, an acid anhydride etc. are mentioned. Among these, solid organic acid hydrazide is preferably used.

The solid organic acid hydrazide is not particularly limited, and examples thereof include sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, malonic acid dihydrazide, and the like. Examples of commercially available products include SDH (manufactured by Nippon Finechem Co., Ltd.). ), Amicure VDH, Amicure UDH (all manufactured by Ajinomoto Fine Techno Co., Ltd.), ADH (manufactured by Otsuka Chemical Co., Ltd.) and the like.

Although content of the said thermosetting agent is not specifically limited, A preferable minimum is 3 weight part and a preferable upper limit is 10 weight part with respect to 100 weight part of said curable resins. If the content of the thermosetting agent is less than 3 parts by weight, the thermosetting may not proceed sufficiently or the reaction may become too slow. When content of the said thermosetting agent exceeds 10 weight part, workability | operativity may fall or reaction may become non-uniform | heterogenous. The minimum with more preferable content of the said thermosetting agent is 4 weight part, and a more preferable upper limit is 8 weight part.

The sealing agent for liquid crystal display elements of the present invention preferably contains a thermal polymerization initiator in addition to the photopolymerization initiator. When the sealing agent for liquid crystal display elements of the present invention contains the above thermal polymerization initiator, the sealing agent can be reliably cured by heat, so that liquid crystal contamination is extremely reduced.

The above-mentioned thermal polymerization initiator has a preferred lower limit of 10 hours half-life temperature of 50 ° C. and a preferred upper limit of 90 ° C. When the 10-hour half-life temperature of the thermal polymerization initiator is less than 50 ° C., the storage stability of the obtained sealing agent for liquid crystal display elements may be deteriorated. If the 10-hour half-life temperature of the thermal polymerization initiator exceeds 90 ° C., the curing of the sealing agent for liquid crystal display elements of the present invention requires a high temperature and a long time, which may affect panel productivity.
In the present specification, the 10-hour half-life temperature means that the concentration of the thermal polymerization initiator is half that before the reaction when the thermal decomposition reaction is carried out at a constant temperature for 10 hours in the presence of an inert gas. Is the temperature at which

The thermal polymerization initiator is not particularly limited, and examples thereof include azo compounds and organic peroxides. Of these, a polymer azo initiator composed of a polymer azo compound is preferable.
In the present specification, the polymer azo compound means a compound having an azo group and generating a radical capable of curing the curable resin by heat and having a molecular weight of 300 or more.

The preferable lower limit of the number average molecular weight of the polymeric azo initiator is 1000, and the preferable upper limit is 300,000. When the number average molecular weight of the polymer azo initiator is less than 1000, the polymer azo initiator may adversely affect the liquid crystal. When the number average molecular weight of the polymeric azo initiator exceeds 300,000, mixing with the curable resin may be difficult. The more preferable lower limit of the number average molecular weight of the polymeric azo initiator is 5000, the more preferable upper limit is 100,000, the still more preferable lower limit is 10,000, and the still more preferable upper limit is 90,000.

Examples of the polymer azo initiator include those having a structure in which a plurality of units such as polydimethylsiloxane and polyalkylene oxide are bonded via an azo group.
As a structure in which a plurality of units such as polyalkylene oxide are bonded, those having a polyethylene oxide structure are preferable.
Examples of such a polymer azo initiator include polycondensates of 4,4′-azobis (4-cyanopentanoic acid) and polyalkylene glycol, and 4,4′-azobis (4-cyanopentanoic acid) and terminal. Examples thereof include polycondensates of polydimethylsiloxane having an amino group. Specifically, for example, VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001 (all manufactured by Wako Pure Chemical Industries, Ltd.) ) And the like.

As the polymer azo initiator, a polymer azo compound represented by the following general formula (I) described in JP-A-2008-50572 and JP-A-2003-12784 is also preferably used. Can do.

In formula (I), R ¹² , R ¹³ , R ²² and R ²³ each independently represents an alkyl group having 1 to 10 carbon atoms or a cyano group, and a and b are each independently a number of 0 to 4 A ¹¹ and A ¹² are polymer chains, and Y ¹¹ and Y ¹² are each independently —CO—O—, —O—CO—, —NH—CO—, —CO—NH—, -O- or -S-.

In said general formula (I), as a C1-C10 alkyl group represented by R < ¹² >, R <^13> , R < ²² > and R < ²³ >, for example, methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, isobutyl, amyl, isoamyl, t-amyl, hexyl, cyclohexyl, cyclohexylmethyl, cyclohexylethyl, heptyl, isoheptyl, t-heptyl, n-octyl, isooctyl, t-octyl, 2-ethylhexyl, n-nonyl, n-decyl etc. are mentioned.

In the above general formula (I), the polymer chains represented by A ¹¹ and A ¹² are not particularly limited. For example, polyoxylene chain, polymethylene chain, polyether chain, polyester chain, polysiloxane chain, poly (meth) acrylate Examples thereof include a chain, a polystyrene-vinyl acetate chain, a polyamide chain, a polyimide chain, a polyurethane chain, a polyurea chain, and a polypeptide chain. Among ^{them, Y 11} is ^-O-CO-, preferably compounds ^{Y 12} is ^-CO-O-, the polymer chain represented by ^{A 11} and ^{A 12,} is a polyether chain and a polyester chain Those are more preferred because they are particularly inexpensive and easy to manufacture.

Among the above general formula (I), among the polymer azo compounds in which A ¹¹ and A ¹² are polyether chains, the compound represented by the following general formula (II) has good solubility and easy molecular weight control. This is more preferable.

In the formula (II), R ¹² , R ¹³ , R ²² , R ²³ , a and b are the same as those in the general formula (I), and R ¹¹ and R ²¹ each independently have 1 to 24 carbon atoms. Z ¹¹ , Z ¹² , Z ²¹ and Z ²² each independently represent an alkylene group having 1 to 4 carbon atoms, and m, n, s and t are each independently 0 to 1000. The sum of m + n and the sum of s + t are each independently 2 or more.

In the general formula (II), examples of the alkylene group having 1 to 4 carbon atoms represented by Z ¹¹ , Z ¹² , Z ²¹ and Z ²² include methylene, ethylene, trimethylene, propylene, propylidene, isopropylidene, tetra Examples include methylene, butylene, isobutylene, ethylethylene, dimethylethylene and the like.
Examples of the alkyl group having 1 to 24 carbon atoms represented by R ¹¹ and R ²¹ include methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, isobutyl, amyl, isoamyl, t- Examples include amyl, hexyl, cyclohexyl, cyclohexylmethyl, cyclohexylethyl, heptyl, isoheptyl, t-heptyl, n-octyl, isooctyl, t-octyl, 2-ethylhexyl, n-nonyl, n-decyl, lauryl, stearyl, behenyl, etc. It is done. The alkyl group having 1 to 24 carbon atoms represented by R ¹¹ and R ²¹ is preferably one having 1 to 4 carbon atoms because of high reactivity.

Among the polymer azo compounds represented by the general formula (I) in which A ¹¹ and A ¹² are polyester chains, the compound represented by the following general formula (III) has good solubility and excellent water resistance. Therefore, it is preferable.

In the formula (III), R ¹² , R ¹³ , R ²² , R ²³ , a and b are the same as those in the general formula (I), and Z ¹³ and Z ²³ each independently have 1 to 18 carbon atoms. R ³¹ and R ⁴¹ each independently represent a hydrogen atom or an alkyl group having 1 to 24 carbon atoms, and p and u are each independently a number from 1 to 1000.

In the general formula (III), examples of the alkylene group having 1 to 18 carbon atoms represented by Z ¹³ and Z ²³ include methylene, ethylene, trimethylene, propylene, propylidene, isopropylidene, tetramethylene, butylene, isobutylene, Ethylethylene, dimethylethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, 1,4-pentanediyl, decamethylene, undecamethylene, 1,4-undecandiyl, dodecamethylene, 1,11-heptadecandiyl, octadeca And methylene.
^The alkyl group having 1 to 24 carbon atoms represented by ^{R 31} and ^{R 41,} for example, those exemplified as ^{R 11} and ^{R 21} in the general formula (II). The alkyl group having 1 to 24 carbon atoms represented by R ³¹ and R ⁴¹ is preferably one having 1 to 4 carbon atoms because of high reactivity.

In the general formula (III), p and u are preferably 20 to 100 because of high reactivity.

The organic peroxide is not particularly limited, and examples thereof include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, peroxy ester, diacyl peroxide, and peroxydicarbonate.

The content of the thermal polymerization initiator in the sealing agent for liquid crystal display elements of the present invention is not particularly limited, but the preferred lower limit is 0.1 parts by weight and the preferred upper limit is 30 parts by weight with respect to 100 parts by weight of the curable resin. is there. When the content of the thermal polymerization initiator is less than 0.1 parts by weight, the obtained sealing agent may not be sufficiently cured. When the content of the thermal polymerization initiator exceeds 30 parts by weight, the viscosity of the obtained sealing agent for liquid crystal display elements is increased, which may adversely affect application workability. The minimum with more preferable content of the said thermal-polymerization initiator is 0.5 weight part, and a more preferable upper limit is 10 weight part.

The sealing agent for liquid crystal display elements of the present invention preferably contains a filler for the purpose of improving the viscosity, improving the adhesiveness due to the stress dispersion effect, improving the linear expansion coefficient, and the like.
The filler is not particularly limited. For example, talc, asbestos, silica, diatomaceous earth, smectite, bentonite, calcium carbonate, magnesium carbonate, alumina, montmorillonite, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, hydroxide Inorganic fillers such as magnesium, aluminum hydroxide, glass beads, silicon nitride, barium sulfate, gypsum, calcium silicate, sericite activated clay, aluminum nitride, polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, acrylic polymer fine particles, etc. Of organic fillers.

It is preferable that the sealing compound for liquid crystal display elements of the present invention further contains a silane coupling agent. The silane coupling agent mainly has a role as an adhesion aid for favorably bonding a sealing agent for a liquid crystal display element and a substrate or the like.

Although the silane coupling agent is not particularly limited, it is excellent in the effect of improving adhesiveness with a substrate and the like, and it can suppress the outflow of the curable resin into the liquid crystal by chemically bonding with the curable resin. For example, γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-isocyanatopropyltrimethoxysilane and the like are preferably used. These silane coupling agents may be used independently and 2 or more types may be used together.

The sealing agent for liquid crystal display elements of the present invention further includes a reactive diluent for adjusting the viscosity, a thixotropic agent for adjusting the thixotropy, a spacer such as a polymer bead for adjusting the panel gap, if necessary. It may contain a curing accelerator such as -P-chlorophenyl-1,1-dimethylurea, an antifoaming agent, a leveling agent, a polymerization inhibitor, and other additives.

The method for producing the sealing agent for liquid crystal display elements of the present invention is not particularly limited. For example, a curable resin, a photopolymerization initiator, a thermosetting agent, and additives that are blended as necessary are conventionally known. And the like.

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

The conductive fine particles are not particularly limited, and metal balls, those obtained by forming a conductive metal layer on the surface of resin fine particles, and the like can be used. Among them, the one in which the conductive metal layer is formed on the surface of the resin fine particles is preferable because the conductive connection is possible without damaging the transparent substrate due to the excellent elasticity of the resin fine particles.

The liquid crystal display element manufactured using the sealing compound for liquid crystal display elements of this invention and / or the vertical conduction material of this invention is also one of this invention.

As a method for producing the liquid crystal display element of the present invention, for example, the liquid crystal display element sealant of the present invention is formed into a rectangular shape on one of two transparent substrates with electrodes such as an ITO thin film by screen printing, dispenser application or the like. A step of forming a seal pattern of the present invention, a step of applying a liquid crystal micro-droplet on the entire surface of the transparent substrate while the sealant for the liquid crystal display element of the present invention is uncured, and immediately overlaying the other transparent substrate And the process of irradiating light, such as an ultraviolet-ray, to seal pattern parts, such as the sealing compound for liquid crystal display elements of this invention, and temporarily hardening a sealing compound, and the process of heating and hardening this temporarily sealing compound And the like.

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal display elements which can suppress generation | occurrence | production of the afterimage in a liquid crystal display element can be provided. Moreover, according to this invention, the vertical conduction material and liquid crystal display element which are manufactured using this sealing compound for liquid crystal display elements can be provided.

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

(Synthesis of epoxy (meth) acrylate)
126 g of bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “Epicoat 1001”) was dissolved in 500 mL of toluene, and 0.1 g of triphenylphosphine was added to obtain a uniform solution. To the obtained solution, 36 g of acrylic acid was added dropwise over 2 hours with stirring under reflux, followed by further stirring under reflux for 6 hours. Next, toluene was removed to obtain a bisphenol A type epoxy acrylate in which all epoxy groups reacted with acrylic acid.

(Synthesis of partially acrylic-modified epoxy resin)
160 g of bisphenol F type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “Epicoat 806”) was dissolved in 500 mL of toluene, and 0.1 g of triphenylphosphine was added to obtain a uniform solution. To the obtained solution, 35 g of acrylic acid was added dropwise over 2 hours with stirring under reflux, followed by further stirring under reflux for 6 hours. Next, by removing toluene, 50% partially acrylic-modified bisphenol F type epoxy resin in which 50 mol% of the epoxy group was reacted with acrylic acid was obtained.

Example 1
(Production of sealant)
As the curable resin, 75 parts by weight of the produced bisphenol A type epoxy acrylate, 25 parts by weight of the produced partially acrylic-modified bisphenol F type epoxy resin, and 1,2-octanedione 1- [4- as the photopolymerization initiator. (Phenylthio) -2- (O-benzoyloxime)] (manufactured by BASF Japan, “IRGACURE OXE01”, extinction coefficient at a wavelength of 405 nm measured in acetonitrile 1.016 × 10 ² mL / g · cm) 0.3 5 parts by weight of a polymer azo compound (manufactured by Wako Pure Chemical Industries, "VPE0201") as a thermal polymerization initiator and 5 parts by weight of adipic acid dihydrazide (manufactured by Otsuka Chemical Co., "ADH") as a thermosetting agent And γ-glycidoxypropyltrimethoxysilane (Shin-Etsu Silicone) as a silane coupling agent Manufactured by “KBM-403”) and 15 parts by weight of silica (manufactured by Admatechs Co., “SO-C2”) as a filler. After stirring with “Taro”), the mixture was uniformly mixed with three ceramic rolls to obtain a sealant.

(Production of liquid crystal display element)
Using a dispenser (manufactured by Musashi Engineering Co., Ltd., “SHOTMASTER 300”), apply the obtained sealant to a transparent electrode substrate with ITO thin film patterning so as to draw a square frame with a line width of about 1.5 mm. A seal pattern was formed. Subsequently, after applying fine droplets of TN liquid crystal (manufactured by Chisso Corporation, “JC-5001LA”) into the frame of the seal pattern with a liquid crystal dropping device, the pressure is reduced to 5 Pa with another transparent electrode substrate and a vacuum bonding device. Laminated together below. After releasing the vacuum, the seal portion was irradiated with ultraviolet rays of 100 mW / cm ² for 30 seconds using a high-pressure mercury lamp. Subsequently, the sealing agent was thermally cured by heating in an oven at 120 ° C. for 60 minutes, thereby producing a liquid crystal display element.

( Comparative Examples 1-4 )
A sealant and a liquid crystal display device were produced in the same manner as in Example 1 except that the materials and the amounts used were those shown in Table 1.
“DAROCUR TPO” in Table 1 is 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (an extinction coefficient of 1.650 × 10 ² mL / g · cm at a wavelength of 405 nm measured in acetonitrile). “IRGACURE 651” is 2,2-dimethoxy-2-phenylacetophenone (an extinction coefficient of 0 mL / g · cm at a wavelength of 405 nm measured in methanol).

<Evaluation>
The following evaluation was performed about the sealing agent and liquid crystal display element which were obtained by the Example and the comparative example. The results are shown in Table 1.

(1) Initial color unevenness (before current test)
The liquid crystal alignment disorder in the vicinity of the sealant immediately after the production of the liquid crystal display elements obtained in Examples and Comparative Examples was confirmed by visual observation. Orientation disturbance is determined by the color unevenness of the display. Depending on the degree of color unevenness, “◎” indicates that there is no color unevenness, “○” indicates that there is slight color unevenness, and there is little color unevenness. The case was evaluated as “Δ”, and the case where there was considerable color unevenness was evaluated as “x”. Note that the liquid crystal display elements evaluated as “◎” and “、” are at a level that causes no problem in practical use.

(2) Burn-in (after current test)
A DC voltage of 10 V was applied to the liquid crystal display element evaluated for “(1) initial color unevenness” for 48 hours, and subsequent burn-in was visually confirmed. Burn-in is judged by the uneven color of the transparent electrode part with patterning of the ITO thin film. Depending on the degree of burn-in, “◎” indicates that there is no burn-in, and “○” indicates that there is slight burn-in. The case where there was a slight burn-in was evaluated as “Δ”, and the case where there was a significant burn-in was evaluated as “x”.

ADVANTAGE OF THE INVENTION According to this invention, the sealing compound for liquid crystal display elements which can suppress generation | occurrence | production of the afterimage in a liquid crystal display element can be provided. Moreover, according to this invention, the vertical conduction material and liquid crystal display element which are manufactured using this sealing compound for liquid crystal display elements can be provided.

Claims (4)

A sealing agent for a liquid crystal display element containing a curable resin, a photopolymerization initiator, a thermal polymerization initiator, and a thermosetting agent,
The photopolymerization initiator has an absorption coefficient of 50 mL / g · cm or more at a wavelength of 405 nm measured in a solvent, and the content of the photopolymerization initiator is 0.01 with respect to 100 parts by weight of the curable resin. A sealing agent for a liquid crystal display element, characterized by being at least part by weight and less than 0.5 part by weight . The sealing agent for liquid crystal display elements according to claim 1, wherein the thermal polymerization initiator is a polymer azo initiator. A vertical conduction material comprising the sealing agent for a liquid crystal display element according to claim 1 or 2 and conductive fine particles. A liquid crystal display element manufactured using the sealing agent for a liquid crystal display element according to claim 1 and / or the vertical conduction material according to claim 3 .