JP4977896B2 - Liquid crystal sealant and liquid crystal display cell using the same - Google Patents

Description

  The present invention relates to a liquid crystal sealant and a liquid crystal display cell using the same. More specifically, the present invention relates to a liquid crystal sealant suitable for manufacturing a liquid crystal display cell by a liquid crystal dropping method and a liquid crystal display cell manufactured using the same.

  With the recent increase in size of liquid crystal display cells, a so-called liquid crystal dropping method with higher mass productivity has become widespread as a method for manufacturing liquid crystal display cells. In the liquid crystal dropping method, a liquid crystal display cell in which liquid crystal is sealed is manufactured by dropping a liquid crystal inside a weir of a liquid crystal sealing agent formed on one substrate and then bonding the other substrate. However, in the liquid crystal dropping method, the liquid crystal sealant and the liquid crystal are in direct contact with each other, so the liquid crystal sealant component is eluted into the liquid crystal and has a problem of contaminating the liquid crystal display area. From the viewpoint of improving the reliability of liquid crystal display cells, a sealing agent with lower contamination is required.

  In the liquid crystal dropping method, three methods, a thermosetting method, a photocuring method, and a photothermal curing combined method, are considered as methods for curing the liquid crystal sealant. In the thermosetting method, there is a problem that the sealant has a low viscosity when heated, so that the seal shape is difficult to maintain, and the liquid crystal is easily contaminated because the uncured liquid crystal sealant and the liquid crystal come into contact with each other when heated.

  On the other hand, the liquid crystal sealant used in the photocuring method includes two types of cationic polymerization type and radical polymerization type depending on the type of photopolymerization initiator. The cationic polymerization type liquid crystal sealing agent has a defect that it is inferior in reliability because a cationic component generated during photocuring contaminates the liquid crystal and lowers the specific resistance of the liquid crystal. In addition, the radical polymerization type liquid crystal sealing agent has a problem that the adhesive strength is not sufficient because the curing shrinkage during photocuring is large. Furthermore, as a problem related to both the cationic polymerization type and radical polymerization type photocuring methods, the light shielding part where the liquid crystal sealant is not exposed to light by the metal wiring part of the array substrate of the liquid crystal display cell and the black matrix part of the color filter substrate. Therefore, there arises a problem that the light-shielding portion becomes uncured.

  As described above, the thermosetting method and the photocuring method have their respective problems, and in fact, the photothermal curing combined method is widely used as a practical curing system. The photothermographic combination method is characterized in that a liquid crystal sealant sandwiched between substrates is first cured by light irradiation and then heated to be secondarily cured (see Patent Document 1). Advantages of thermosetting include significantly improved adhesive strength and moisture resistance reliability, and can be cured by thermosetting even if there is a light-shielding portion. As a characteristic required for the liquid crystal sealant used in the photothermal curing combined method, it is important that the liquid crystal sealant does not contaminate the liquid crystal in each step before and after light irradiation and before and after heat curing. From the viewpoint of workability, it is desired that the viscosity change during use at room temperature is small and the pot life is good. On the other hand, from the viewpoint of the characteristics of the liquid crystal to be sealed and the cost, it is generally 130 ° C or lower. There is a need for low-temperature curing within 1 hour.

  Photo-curing combined method The cured resin system used for the liquid crystal sealant is generally a cured resin system having both a thermosetting epoxy group and a photo-curing (meth) acryloyl group reactive group. It is. As such a cured resin system, a mixed resin system of an epoxy resin and an epoxy (meth) acrylate resin, or a partially (meth) acryloylated epoxy resin is used. The curable resin system further requires a photopolymerization initiator component for photocuring the (meth) acryloyl group and a curing agent component for thermosetting the epoxy group. As the curing agent component, hydrazide compounds such as adipic acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide, Amicure VDH (manufactured by Ajinomoto Fine Techno Co., Ltd .; dihydrazides having a valine hydantoin skeleton) are generally used. However, the hydrazide compound is suitable not only for reacting with an epoxy group but also for reacting with a (meth) acryloyl group, so that it is suitable for curing a light-shielding part. On the other hand, it causes a change with time such as viscosity at room temperature. Therefore, the selection of the curing agent is an important factor that greatly affects the workability of the liquid crystal sealing agent, such as liquid crystal contamination and pot life. Among the hydrazides, sealants using adipic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, isophthalic acid dihydrazide, etc. are relatively excellent in storage stability, but are not sufficient, longer working time and stable work There is a need for a sealing agent having a property.

  As described above, there is a need for a liquid crystal sealing agent for a liquid crystal dropping method that has low liquid crystal contamination, excellent pot life at room temperature, and low temperature curability.

  On the other hand, regarding a resin composition using a hydrazide compound, Patent Document 2 discloses tris (2-hydrazinocarbonylethyl) isocyanate, which is a hydrazide compound related to the present invention, and is useful as an epoxy resin curing agent. Yes. However, there is no description regarding the storage stability, curing characteristics, and the like of the epoxy resin composition, and there is no mention of the possibility of being applicable to a curing agent for a liquid crystal sealant. Further, Patent Document 3 shows that polyvalent carboxylic acids are effective as curing accelerators in a curing system of an epoxy resin and a hydrazide curing agent, but mentions the possibility of being applicable to liquid crystal sealing agents as well. There is no.

Japanese Patent No. 2846842 JP 2002-371069 A Japanese Patent Laid-Open No. 62-172014

  The present invention relates to a liquid crystal sealant and a liquid crystal display cell using the same, and more particularly to a liquid crystal sealant suitable for manufacturing a liquid crystal display cell by a liquid crystal dropping method and a liquid crystal display cell manufactured using the same. is there. In particular, it aims to greatly improve the pot life at room temperature, and at the same time to propose a liquid crystal sealant with excellent low-temperature curability, liquid crystal contamination, coating workability, bonding properties, and adhesive strength. To do.

[式中、Ｒ^１〜Ｒ^３は各々独立して水素又は下記式（２）

（式中、ｎは１〜６の整数を示す）
で表される分子骨格を示す]As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a resin composition having a specific composition can achieve the above object, and have completed the present invention.
That is, the present invention relates to the following (1) to (9).
(1) (a) a hydrazide compound having an isocyanuric ring skeleton represented by the following general formula (1), and (b) an epoxy resin, a (meth) acrylated epoxy resin and a partial (meth) acrylated epoxy resin A liquid crystal sealant comprising one or more curable resins.

[Wherein R ^{1 to} R ³ are each independently hydrogen or the following formula (2)

(In the formula, n represents an integer of 1 to 6)
The molecular skeleton represented by

（３）硬化性樹脂（ｂ）がエポキシ樹脂と（メタ）アクリル化エポキシ樹脂の混合物である請求項１又は２に記載の液晶シール剤。
（４）さらに、硬化促進剤として（ｃ）多価カルボン酸を含有することを特徴とする請求項１乃至３に記載の液晶シール剤
（５）多価カルボン酸が分子内に下記一般式（４）で表されるイソシアヌル環骨格を有する多価カルボン酸である（１）乃至（４）のいずれかに記載の液晶シール剤。

[式中、Ｔ^１〜Ｔ^３は各々独立して水素又は下記式（５）

（式中、ｎは１〜６の整数を示す）
で表される分子骨格を表す](2) The liquid crystal sealing agent according to (1), wherein the hydrazide compound (a) is a compound represented by the following formula (3).

(3) The liquid crystal sealant according to claim 1 or 2, wherein the curable resin (b) is a mixture of an epoxy resin and a (meth) acrylated epoxy resin.
(4) The liquid crystal sealant according to any one of claims 1 to 3, further comprising (c) a polyvalent carboxylic acid as a curing accelerator, wherein the polyvalent carboxylic acid has the following general formula ( The liquid crystal sealant according to any one of (1) to (4), which is a polyvalent carboxylic acid having an isocyanuric ring skeleton represented by 4).

[Wherein T ^{1 to} T ³ are each independently hydrogen or the following formula (5)

(In the formula, n represents an integer of 1 to 6)
Represents a molecular skeleton represented by

（７）多価カルボン酸（ｃ）が下記式(７)で表される化合物である（５）に記載の液晶シール剤。

（８）前記（１）乃至（７）のいずれかに記載の液晶シール剤の硬化物でシールされた液晶表示セル。
（９）２枚の基板により構成される液晶表示セルにおいて、一方の基板に形成された（１）乃至（７）のいずれかに記載の液晶シール剤堰の内側に液晶を滴下した後、もう一方の基板を貼り合わせ、次いで硬化することを特徴とする液晶表示セルの製造方法。(6) The liquid crystal sealing agent according to (5), wherein the polyvalent carboxylic acid (c) is a compound represented by the following formula (6).

(7) The liquid crystal sealing agent according to (5), wherein the polyvalent carboxylic acid (c) is a compound represented by the following formula (7).

(8) A liquid crystal display cell sealed with a cured product of the liquid crystal sealing agent according to any one of (1) to (7).
(9) In a liquid crystal display cell composed of two substrates, after the liquid crystal is dropped inside the liquid crystal sealing agent weir according to any one of (1) to (7) formed on one substrate, A method for producing a liquid crystal display cell, characterized in that one substrate is bonded and then cured.

  The liquid crystal sealing agent of the present invention is excellent in application workability and bonding property to a substrate, has a long pot life, and is excellent in strong adhesive strength, low liquid crystal contamination, and gap forming ability. By using the liquid crystal sealing agent of the present invention for the liquid crystal dropping method, it is possible to improve the yield and productivity in the production of liquid crystal display cells.

Hereinafter, the present invention will be described in detail.
The liquid crystal sealing agent used in the present invention contains a hydrazide compound (a) having an isocyanuric ring skeleton represented by the general formula (1) as a curing agent.
These hydrazide compounds having an isocyanuric ring skeleton can be synthesized by a conventional method such as esterification of a carboxylic acid compound having the skeleton and further reaction with hydrated hydrazine under heating. Specific examples of the hydrazide compound include tris (2-hydrazinocarbonylmethyl) isocyanurate (the following formula (8)), tris (2-hydrazinocarbonylethyl) isocyanurate (the following formula (9)), tris ( Although 2-hydrazinocarbonylpropyl) isocyanurate (following formula (10)), bis (2-hydrazinocarbonylethyl) isocyanurate (following formula (11)), etc. are mentioned, it does not specifically limit. Tris (2-hydrazinocarbonylethyl) isocyanurate is commercially available from Nippon Finechem Co., Ltd. under the trade name HCIC.

Liquid crystal dripping type Liquid crystal sealant curing agent, after heating, after light irradiation, the liquid crystal sealant starts to react uniformly and quickly without contaminating the liquid crystal. It is important that is good. In the case of solid dispersion type latent thermosetting agents, if the particle size is uneven and there is a large particle size, or if the dispersion is insufficient and uneven, the curing will not be performed uniformly and the cause of the cell gap failure Or liquid crystal contamination occurs, resulting in a display failure of the liquid crystal panel. In view of this point, it is preferable to use a hydrazide compound having an isocyanuric ring skeleton used in the present invention that is finely pulverized to an average particle diameter of 3 μm or less as measured by a laser diffraction / scattering particle size distribution analyzer. More preferably, the average particle size is 2 μm or less, and the lower limit of the average particle size is about 0.1 μm. Similarly, the maximum particle size is preferably 8 μm or less, more preferably 5 μm or less. A sealant using a hydrazide compound having an isocyanuric ring skeleton has a very good pot life at room temperature, and exhibits moderate curability even at 120 ° C. for 1 hour. Since the hydrazide compound having an isocyanuric ring skeleton has almost no solubility in the liquid crystal, the contamination property of the encapsulated liquid crystal becomes extremely low.
The amount of the hydrazide compound (a) having an isocyanuric ring skeleton as a curing agent is preferably 1 part by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the curable resin (b).

  As the curable resin of the present invention, one or two or more curable resins (b) selected from an epoxy resin, a (meth) acrylated epoxy resin, and a partial (meth) acrylated epoxy resin are used. Examples thereof include an epoxy resin, a mixture of an epoxy resin and a (meth) acrylated epoxy resin, a (meth) acrylated epoxy resin, and a partial (meth) acrylated epoxy resin. (Here, “(meth) acryl” means “acryl” and / or “methacryl”. The same applies hereinafter.) Any of the curable resins used in the present invention has low contamination and solubility in liquid crystals. Examples of suitable epoxy resins include, but are not limited to, bisphenol S-type epoxy resins, resorcin diglycidyl ether multimers, diglycidyl ethers of ethylene oxide-added bisphenol S, and the like. The (meth) acryloylated epoxy resin and the partially (meth) acryloylated epoxy resin are obtained by a reaction between the epoxy resin and (meth) acrylic acid. Although it does not specifically limit as an epoxy resin used as a raw material, An epoxy resin more than bifunctional is preferable, for example, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a phenol novolac type epoxy resin , Cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol F novolak type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin , Isocyanurate type epoxy resins, phenol novolac type epoxy resins having a triphenolmethane skeleton, diglycidyl ethers of difunctional phenols, difunctional alcohols Diglycidyl ether compound, and their halides, and the like hydrogenated product. Of these, bisphenol type epoxy resin and novolac type epoxy resin are more preferable from the viewpoint of liquid crystal contamination. Further, the ratio of the epoxy group to the (meth) acryloyl group is not limited, and is appropriately selected from the viewpoint of process compatibility and liquid crystal contamination.

As the curable resin, a monomer and / or oligomer of (meth) acrylic acid ester may be further used for controlling the reactivity and viscosity. Examples of such a monomer or oligomer include a reaction product of dipentaerythritol and (meth) acrylic acid, a reaction product of dipentaerythritol / caprolactone and (meth) acrylic acid, and the like, but has low contamination with liquid crystals. If it is a thing, it will not restrict | limit in particular.
The amount used as the curable resin (b) is appropriately determined in consideration of the workability and physical properties of the obtained liquid crystal sealant, and is usually about 25 to 80% by weight in the liquid crystal sealant, preferably 25. ~ 75 wt%.

When a curable resin containing a (meth) acryloyl group is used for the liquid crystal sealant of the present invention, a radical reaction type photopolymerization initiator is used in order to impart photocurability. Any initiator can be used as long as it has sensitivity near i-line (365 nm), which has a relatively small influence on liquid crystal properties, and has low liquid crystal contamination. Specific examples of the radical reaction type photopolymerization initiator that can be used include, for example, benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, diethylthioxanthone, benzophenone, 2-ethylanthraquinone, 2-hydroxy-2-methylpropiophenone. 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propane, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-hydroxyethyl acrylate, isophorone diisocyanate and 2-hydroxy-1- [ Reaction product of 4- (2-hydroxyethoxy) phenyl] -2-methylpropan-1-one, 2-isocyanatoethyl methacrylate and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl]- 2-methyl group It can be mentioned reaction products of the pan-1-one.
When a radical reaction type photopolymerization initiator is added and used, the amount used is usually about 0.1 to 10% by weight in the liquid crystal sealant.

  In order to improve the low temperature curability, the liquid crystal sealant of the present invention desirably contains a polyvalent carboxylic acid (c) as a curing accelerator. Specific examples of the polyvalent carboxylic acid include aromatic carboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid and benzophenone tetracarboxylic acid, aliphatic carboxylic acids such as decanedioic acid and dodecanedioic acid, and the above-mentioned And polyvalent carboxylic acid having an isocyanuric ring skeleton represented by the general formula (4). Specific examples of the polyvalent carboxylic acid having an isocyanuric ring skeleton represented by the general formula (4) include tris (2-carboxymethyl) isocyanurate (the following formula (12)) and tris (2-carboxyethyl). Examples include isocyanurate (following formula (6)), tris (2-carboxypropyl) isocyanurate (following formula (7)), and bis (2-carboxyethyl) isocyanurate (following formula (13)).

Among these curing accelerators, in the present invention, a polyvalent carboxylic acid having an isocyanuric ring skeleton is preferable from the viewpoint of temporal stability and liquid crystal contamination.
The addition amount of the curing accelerator is preferably 0.1 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the curable resin (b).

  The liquid crystal sealant of the present invention may contain an inorganic filler for the purpose of improving adhesiveness, moisture resistance and the like. The inorganic filler that can be used is not particularly limited. Specifically, spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, Calcium sulfate, mica, talc, clay, alumina, magnesium oxide, zirconium oxide, aluminum hydroxide, magnesium hydroxide, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, disulfide Examples include molybdenum and asbestos, preferably spherical silica, fused silica, crystalline silica, titanium oxide, titanium black, silicon nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, al Na, aluminum hydroxide, calcium silicate, aluminum silicate. Two or more of the above inorganic fillers may be mixed and used.

The average particle size of the inorganic filler used in the present invention is preferably 3 μm or less. If the average particle size is larger than 3 μm, there may be a problem in forming a gap when the upper and lower glass substrates are bonded together during the production of the liquid crystal cell. The lower limit of the average particle size of the inorganic filler is usually about 0.01 μm.
The content of the inorganic filler used in the present invention in the liquid crystal sealant is usually 2 to 60% by weight, preferably 5 to 50% by weight. When the content of the filler is lower than 2% by weight, the adhesive strength to the glass substrate is lowered, and the moisture resistance reliability is inferior, so that the decrease in the adhesive strength after moisture absorption may be increased. Further, when the filler content is more than 60% by weight, the filler content is too high, and the gap of the liquid crystal cell may not be formed because the filler is not easily crushed.

  In addition, an organic filler may be further added to the liquid crystal sealant of the present invention as long as the characteristics of the liquid crystal sealant are not affected. Examples of the organic filler include polymer beads and core-shell type rubber fillers. Two or more of these fillers may be mixed and used.

The liquid crystal sealing agent of the present invention preferably contains a silane coupling agent in order to improve the adhesive strength. Examples of silane coupling agents that can be used include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2- (3,4-epoxycyclohexyl). ) Ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloxypropyltri Methoxy Run, 3-chloropropyl methyl dimethoxy silane, silane coupling agents such as 3-chloropropyl trimethoxysilane. These silane coupling agents may be used in combination of two or more. Among these, in order to obtain better adhesive strength, the silane coupling agent is preferably a silane coupling agent having an amino group. By using a silane coupling agent, an adhesive strength is improved and a liquid crystal sealing agent having excellent moisture resistance reliability can be obtained.
When a coupling agent is added, the amount used is usually about 0.1 to 5% by weight in the liquid crystal sealant.

  The liquid crystal sealant according to the present invention may further contain an organic solvent and additives such as pigments, leveling agents, and antifoaming agents as necessary.

  In order to obtain the liquid crystal sealant of the present invention, first, the resin component is dissolved and mixed, and the filler component and the thermosetting agent are uniformly mixed by a known mixing device such as a three roll, sand mill, ball mill, planetary mixer, etc. By doing so, the liquid crystal sealing agent of the present invention can be produced. In order to remove impurities after mixing is completed, it is preferable to perform filtration.

In the liquid crystal cell of the present invention, a pair of substrates each having a predetermined electrode formed on the substrate are arranged opposite to each other at a predetermined interval, the periphery is sealed with the liquid crystal sealant of the present invention, and the liquid crystal is sealed in the gap. . The kind of liquid crystal to be sealed is not particularly limited. Here, the substrate is composed of a combination of substrates made of glass, quartz, plastic, silicon, etc. and having light transparency in at least one of them. For example, after adding a spacer (gap control material) such as glass fiber to the liquid crystal sealant of the present invention, the liquid crystal sealant is applied in a dam shape to one of the pair of substrates by a dispenser or the like, Liquid crystal is dropped inside the liquid crystal sealing agent weir, and another glass substrate is stacked in a vacuum to form a gap. After forming the gap, the liquid crystal seal portion is irradiated with ultraviolet rays by an ultraviolet irradiator to be photocured. UV irradiation dose is usually ^{200mJ / cm 2 ~6000mJ / cm 2} , preferably exposure dose of ^{500mJ / cm 2 ~4000mJ / cm 2} . Then, the liquid crystal display cell of this invention can be obtained by hardening at 90-140 degreeC for 1-2 hours. Examples of the spacer include glass fiber, silica beads, and polymer beads. The diameter varies depending on the purpose, but is usually 2 to 8 μm, preferably 4 to 7 μm. The amount used is usually 0.1 to 4 parts by weight, preferably about 0.5 to 2 parts by weight with respect to 100 parts by weight of the liquid crystal sealant of the present invention.

  The liquid crystal sealant of the present invention has extremely low contamination to the liquid crystal throughout the manufacturing process, and is easy to apply to the substrate, adherence, adhesion strength, pot life at room temperature, and low temperature curability. Excellent. The liquid crystal display cell of the present invention thus obtained has no display defects due to liquid crystal contamination, and has excellent adhesion and moisture resistance reliability.

(Example)
Hereinafter, the present invention will be described in more detail with reference to examples.

  Epoxy acrylate resin KAYARAD R-94220 (manufactured by Nippon Kayaku Co., Ltd .; epoxy acrylate of bisphenol F epoxy resin), epoxy resin RE-203 (manufactured by Nippon Kayaku Co., Ltd .; epoxy equivalent 233 g / eq, ethylene oxide-added bisphenol S-type epoxy resin) 25 parts by weight, photopolymerization initiator KAYACURE RPI-4 (manufactured by Nippon Kayaku Co., Ltd .; 2-isocyanatoethyl methacrylate and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl]- 2 parts by weight of a reaction product with 2-methylpropan-1-one) and 1.5 parts by weight of silane coupling agent Silaace S-510 (manufactured by Chisso Corporation; 3-glycidoxypropyltrimethoxysilane) Thus, a resin liquid was obtained. Next, 17.5 parts by weight of Nanotech Alumina SPC (manufactured by C-I Kasei Co., Ltd .; spherical alumina, average particle size of 50 nm) as a filler, butadiene / alkyl methacrylate / styrene copolymer (Rohm and Haas Co., Ltd .; Paraloid EXL-) 2655) 1.5 parts by weight are uniformly mixed with a bead mill, and further tris (2-hydrazinocarbonylethyl) isocyanurate finely pulverized product (manufactured by Nippon Finechem Co., Ltd .; HCIC is jet mill with an average particle size of 1.5 μm, maximum 14 parts by weight, pulverized dodecanedioic acid (manufactured by Ube Industries, Ltd .: dodecanedioic acid pulverized to a mean particle size of 1.5 μm and maximum particle size of 5 μm) 3 The liquid crystal sealant of the present invention was obtained by mixing parts by weight and kneading with three rolls. The viscosity (25 ° C.) of the liquid crystal sealant was 300 Pa · s (25 ° C., R-type viscometer (manufactured by Toki Sangyo Co., Ltd.)).

  Epoxy acrylate resin KAYARAD R-94220 (manufactured by Nippon Kayaku Co., Ltd .; epoxy acrylate of bisphenol F epoxy resin), epoxy resin RE-203 (manufactured by Nippon Kayaku Co., Ltd .; epoxy equivalent 233 g / eq, ethylene oxide-added bisphenol S-type epoxy resin) 25 parts by weight, photopolymerization initiator KAYACURE RPI-4 (manufactured by Nippon Kayaku Co., Ltd .; 2-isocyanatoethyl methacrylate and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl]- 2 parts by weight of a reaction product with 2-methylpropan-1-one) and 1.5 parts by weight of silane coupling agent Silaace S-510 (manufactured by Chisso Corporation; 3-glycidoxypropyltrimethoxysilane) Thus, a resin liquid was obtained. Next, 17.5 parts by weight of Nanotech Alumina SPC (manufactured by C-I Kasei Co., Ltd .; spherical alumina, average particle size of 50 nm) as a filler, butadiene / alkyl methacrylate / styrene copolymer (Rohm and Haas Co., Ltd .; Paraloid EXL-) 2655) 1.5 parts by weight are uniformly mixed with a bead mill, and further tris (2-hydrazinocarbonylethyl) isocyanurate finely pulverized product (manufactured by Nippon Finechem Co., Ltd .; HCIC is jet mill with an average particle size of 1.5 μm, maximum 14 parts by weight, finely pulverized to a particle size of 5 μm), tris (2-carboxyethyl) isocyanurate pulverized product (manufactured by Shikoku Kasei Kogyo Co., Ltd.) Finely pulverized product) 3 parts by weight were mixed and kneaded by three rolls to obtain the liquid crystal sealant of the present invention. The viscosity (25 ° C.) of the liquid crystal sealant was 250 Pa · s (25 ° C., R-type viscometer (manufactured by Toki Sangyo Co., Ltd.)).

  Epoxy acrylate resin KAYARAD R-94220 (manufactured by Nippon Kayaku Co., Ltd .; epoxy acrylate of bisphenol F epoxy resin), epoxy resin RE-203 (manufactured by Nippon Kayaku Co., Ltd .; epoxy equivalent 233 g / eq, ethylene oxide-added bisphenol S-type epoxy resin) 25 parts by weight, photopolymerization initiator KAYACURE RPI-4 (manufactured by Nippon Kayaku Co., Ltd .; 2-isocyanatoethyl methacrylate and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl]- 2 parts by weight of a reaction product with 2-methylpropan-1-one) and 1.5 parts by weight of silane coupling agent Silaace S-510 (manufactured by Chisso Corporation; 3-glycidoxypropyltrimethoxysilane) Thus, a resin liquid was obtained. Next, 17.5 parts by weight of Nanotech Alumina SPC (manufactured by C-I Kasei Co., Ltd .; spherical alumina, average particle size of 50 nm) as a filler, butadiene / alkyl methacrylate / styrene copolymer (Rohm and Haas Co., Ltd .; Paraloid EXL-) 2655) 1.5 parts by weight are uniformly mixed with a bead mill, and further tris (2-hydrazinocarbonylethyl) isocyanurate finely pulverized product (manufactured by Nippon Finechem Co., Ltd .; HCIC is jet mill with an average particle size of 1.5 μm, maximum 14 parts by weight, finely pulverized to a particle size of 5 μm), tris (2-carboxypropyl) isocyanurate pulverized product (manufactured by Shikoku Kasei Kogyo Co., Ltd .: C3-CIC acid with jet mill, average particle size 1.5 μm, maximum particle size The liquid crystal sealant of the present invention mixed with 3 parts by weight and kneaded by a three roll Got. The viscosity (25 ° C.) of the liquid crystal sealant was 350 Pa · s (25 ° C., R-type viscometer (manufactured by Toki Sangyo Co., Ltd.)).

Liquid crystal contamination (UV irradiation and heat curing)
The liquid crystal sealing material placed 0.5g of a sample bottle, a liquid crystal (Merck, MLC-6866-100) was added to 1g, after irradiation with ultraviolet rays of 3000 mJ / cm ² by UV irradiation machine, 1 hour 120 ° C. oven I put it in. After standing at room temperature for 30 minutes, the liquid crystal was taken out from the sample bottle, and the elution amount (ppm) of the sealant component was quantified by gas chromatography. The results are shown in Table 1.

Liquid crystal contamination (thermal curing only)
0.5 g of a liquid crystal sealant was put in a sample bottle, 1 g of liquid crystal (MLC-6866-100, manufactured by Merck & Co., Inc.) was added, and the mixture was then placed in a 120 ° C. oven for 1 hour. Immediately after taking out from the oven, the liquid crystal was taken out from the sample bottle, and the elution amount (ppm) of the sealant component was quantified by gas chromatography. The results are shown in Table 2.

Adhesive strength 1 g of 5 μm glass fiber is added as a spacer to 100 g of the obtained liquid crystal sealant and mixed and stirred. This liquid crystal sealant is applied onto a 50 mm × 50 mm glass substrate, a 1.5 mm × 1.5 mm glass piece is bonded onto the liquid crystal sealant, and irradiated with 3 J / cm ² ultraviolet rays by a UV irradiator. And cured by heat. The thermosetting conditions were 100 ° C. for 1 hour and 120 ° C. for 1 hour. The shear bond strength of the glass pieces was measured with a bond tester manufactured by Seishin Shoji. The results are shown in Table 3.

Pot life The viscosity change at 25 ° C. of the obtained liquid crystal sealant was measured. Table 3 shows the rate of increase in viscosity (%) relative to the initial viscosity.

  As shown in Tables 1, 2, and 3, the sealant of the example according to the present invention is a sealant having low liquid crystal contamination, excellent adhesiveness, little change in viscosity, and good workability. In particular, it can be seen that the polyvalent carboxylic acid having an isocyanuric ring skeleton used in Examples 2 and 3 is excellent in the reliability of the resulting panel because it is difficult to elute into the liquid crystal and has little contamination.

Claims (9)

(A) One type selected from a hydrazide compound having an isocyanuric ring skeleton represented by the following general formula (1), and (b) an epoxy resin, a (meth) acrylated epoxy resin and a partially (meth) acrylated epoxy resin Or the liquid crystal sealing agent characterized by containing 2 or more types of curable resin.

[Wherein R ^{1 to} R ³ are each independently hydrogen or the following formula (2)

(In the formula, n represents an integer of 1 to 6)
The molecular skeleton represented by The liquid crystal sealant according to claim 1, wherein the hydrazide compound (a) is a compound represented by the following formula (3).

  The liquid crystal sealant according to claim 1 or 2, wherein the curable resin (b) is a mixture of an epoxy resin and a (meth) acrylated epoxy resin.   Furthermore, (c) polyhydric carboxylic acid is contained as a hardening accelerator, The liquid-crystal sealing compound of Claim 1 thru | or 3 characterized by the above-mentioned. The liquid crystal sealant according to any one of claims 1 to 4, wherein the polyvalent carboxylic acid (c) is a polyvalent carboxylic acid having an isocyanuric ring skeleton represented by the following general formula (4) in the molecule.

[Wherein T ^{1 to} T ³ are each independently hydrogen or the following formula (5)

(In the formula, n represents an integer of 1 to 6)
The molecular skeleton represented by The liquid crystal sealant according to claim 5, wherein the polyvalent carboxylic acid (c) is a compound represented by the following formula (6).

The liquid crystal sealing agent according to claim 5, wherein the polyvalent carboxylic acid (c) is a compound represented by the following formula (7).

  A liquid crystal display cell sealed with a cured product of the liquid crystal sealing agent according to claim 1.   In a liquid crystal display cell constituted by two substrates, after the liquid crystal is dropped inside the liquid crystal sealing agent weir according to claim 1 formed on one substrate, the other substrate is attached. A method for producing a liquid crystal display cell, characterized by combining and then curing.