JP5182834B2 - 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. In view of improving the reliability of liquid crystal display cells, a liquid crystal sealant 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 demand for low-temperature curing within 1 hour, more preferably at 100 ° C. for about 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. The hydrazide compound is suitable not only for reacting with an epoxy group by heating but also for reacting with a (meth) acryloyl group, so that it is suitable for curing a light shielding part, but it causes a change with time such as viscosity at room temperature. The selection of the curing agent is an important factor that greatly affects the workability of the liquid crystal sealant, 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 and the like are relatively excellent in storage stability, but have low temperature curability due to their high melting point. On the other hand, Amicure VDH, which is a low-melting hydrazide compound, is excellent in low-temperature curability but is not good in storage stability.

  By the way, the liquid crystal dropping method by only thermosetting without using photocuring is not easily realized because it involves difficulties such as seal shape retention and liquid crystal contamination as described above. It is considered that, in principle, it is possible to maintain the shape and reduce contamination by reacting and thickening at a relatively low temperature at the time of heat curing. In order to cure the sealant quickly, there is a technique of adding a low-temperature curing accelerator, such as imidazoles, amine adducts, tertiary amines, triphenylphosphine, etc., which are usually used as accelerators for epoxy resins. All of the phosphines have problems such as contact with the liquid crystal to contaminate it and lower the specific resistance value, and the pot life is very short and there are practical problems. An effective curing system for the thermosetting liquid crystal dropping method including the curing system used has not been found yet. The industrial merit of performing the liquid crystal dropping method only by thermal curing is that no expensive photomask and UV lamp that protect the liquid crystal and alignment film from UV light are required during UV curing, and the power cost required for UV lamp lighting Can be reduced.

  As described above, there is a need for a liquid crystal sealant for a liquid crystal dropping method that cures at a lower temperature, has a long pot life and stable workability. On the other hand, regarding a resin composition using a dihydrazide compound, Patent Document 2 shows that polyvalent carboxylic acids are effective as a curing accelerator in a curing system of an epoxy resin and a dihydrazide curing agent. There is no mention of the possibility of being applicable to agents.

Japanese Patent No. 2846842 Japanese Patent Laid-Open No. 62-172014

  The present invention firstly provides a liquid crystal sealant that is excellent in low-temperature curability, at the same time has low liquid crystal contamination, has a long pot life, and has a good workability for application to a substrate, bonding properties, and adhesive strength, The second object is to provide a liquid crystal sealant effective for the thermosetting liquid crystal dropping method.

[式中、Ｔ１〜Ｔ３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]
（２）
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上記（１）に記載の液晶シール剤、
（３）
（ｃ）硬化促進剤が下記式(３)で表される化合物である上記（１）又は（２）に記載の液晶シール剤、

（４）
（ｃ）硬化促進剤が下記式(４)で表される化合物である上記（１）又は（２）に記載の液晶シール剤、

（５）
上記（１）乃至（４）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、
（６）
２枚の基板により構成される液晶表示セルにおいて、一方の基板に上記（１）乃至（４）のいずれか一項に記載の液晶シール剤を用いてシールパターンを形成し、シールパターン内又は対向基板に液晶を滴下した後、対向基板を貼り合わせ、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、
（７）
紫外線及び／又は可視光線による一次硬化を経て、次いで加熱による二次硬化を行う上記（６）に記載の液晶表示セルの製造方法、
（８）
紫外線及び／又は可視光線による硬化を経ず、加熱のみで硬化を行う上記（６）に記載の液晶表示セルの製造方法、
に関する。 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
(1)
(A) a dihydrazide compound, (b) one or more selected from epoxy resins, (meth) acrylated epoxy resins and partially (meth) acrylated epoxy resins as a curable resin, and (c) a curing accelerator A liquid crystal sealant comprising a polyvalent carboxylic acid compound having an isocyanuric ring skeleton represented by the following general formula (1) :

[Wherein T1 to T3 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
(2)
The liquid crystal sealing agent according to the above (1), wherein the curable resin (b) is a mixture of an epoxy resin and a (meth) acrylated epoxy resin,
(3)
(C) The liquid crystal sealing agent according to the above (1) or (2), wherein the curing accelerator is a compound represented by the following formula (3):

(4)
(C) The liquid crystal sealant according to the above (1) or (2), wherein the curing accelerator is a compound represented by the following formula (4):

(5)
A liquid crystal display cell sealed with a cured product of the liquid crystal sealant according to any one of (1) to (4) above,
(6)
In a liquid crystal display cell constituted by two substrates, a seal pattern is formed on one substrate using the liquid crystal sealant according to any one of (1) to (4), and the seal pattern is formed in or opposite to the seal pattern. A method of manufacturing a liquid crystal display cell, characterized in that after the liquid crystal is dropped on the substrate, the opposite substrate is bonded and then cured;
(7)
The method for producing a liquid crystal display cell according to the above (6), which undergoes primary curing with ultraviolet rays and / or visible light, and then performs secondary curing with heating,
(8)
The method for producing a liquid crystal display cell according to the above (6), in which the curing is performed only by heating without being cured by ultraviolet rays and / or visible light,
About.

  The liquid crystal sealing agent of the present invention is particularly excellent in low-temperature curability, and at the same time has low liquid crystal contamination and a long pot life, and has excellent coating workability, bonding properties, and adhesive strength on a substrate. 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 dihydrazide compound (a) as a curing agent. Dihydrazides in this case refer to those having two hydrazide groups in the molecule. Specific examples thereof include, for example, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, adipic acid dihydrazide, pimelin. Acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecandiodihydrazide, hexadecandiodihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide dihydrazide diacid 2,6-naphthoic acid dihydrazide, 4,4-bisbenzene dihydrazide, 1,4-naphthoic acid dihydrazide, 2,6-pyridinedihydrazide, 1 1,3-bis (hydrazinocarboethyl Roh ethyl) -5-isopropyl hydantoin and the like, but not limited thereto. When dihydrazide is used as a curing agent, it is preferable to make the particle size fine and uniformly disperse. Among dihydrazides, adipic acid dihydrazide, isophthalic acid dihydrazide, and 1,3-bis (hydrazinocarbonoethyl) -5-isopropylhydantoin are particularly preferable from the viewpoint of liquid crystal contamination. The average particle diameter is preferably 3 μm or less, and more preferably 2 μm or less, because if the average particle size is too large, it becomes a cause of defects such as failure to form a gap when the upper and lower glass substrates are bonded together when manufacturing a narrow gap liquid crystal cell. Similarly, the maximum particle size is preferably 8 μm or less, more preferably 5 μm or less. The particle size of the curing agent was measured with a laser diffraction / scattering particle size distribution analyzer (dry type) (manufactured by Seishin Enterprise Co., Ltd .; LMS-30).

  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, the dihydrazide compound used in the present invention is preferably a finely pulverized one having an average particle size of 3 μm or less as measured by a laser diffraction / scattering particle size distribution analyzer, and more preferably an average particle The diameter is 2 μm or less, and the lower limit of the average particle diameter 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 dihydrazide compound has a very good pot life at room temperature, and exhibits moderate curability even at 0 ° C. for 1 hour. Since the dihydrazide compound has almost no solubility in the liquid crystal, the contamination of the encapsulated liquid crystal is extremely low. The amount of the dihydrazide compound (a) used as the 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 novolac 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. In the present invention, the amount used as the curable resin (b) is within a range that does not affect 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. And preferably 25 to 75% by weight.

  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-generating photopolymerization initiator that can be used include benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, diethyl thioxanthone, 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 about 0.1 to 5% by weight in the liquid crystal sealant.

The liquid crystal sealing material of the present invention you blended polycarboxylic acid compound having an isocyanuric ring structure represented by the above formula as a curing accelerator for improving the low-temperature curability (1) (c). The polyvalent carboxylic acid having an isocyanuric ring structure represented by a general formula (1), specifically, tris (2-carboxymethyl) diisocyanate isocyanurate (formula (5)), tris (2-carboxyethyl ) Isocyanurate (following formula (3)), tris (2-carboxypropyl) isocyanurate (following formula (4)), bis (2-carboxyethyl) isocyanurate (following formula (6)).

The addition amount of the hardening accelerator (c), the curable resin (b) 100 parts by weight per 0.1 part by weight or more, is preferably not more than 10 parts by weight.

  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.

  Below is the one. If the average particle size is larger than 3 μm, it will hinder the gap formation 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. 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-methacryloxypropyltrimethoxy Examples include silane coupling agents such as silane, 3-chloropropylmethyldimethoxysilane, and 3-chloropropyltrimethoxysilane. 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 material 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 about 0.1 to 15% 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. The amount of UV irradiation is usually 200 mJ / cm2 to 6000 mJ / cm2, preferably 500 mJ / cm2 to 4000 mJ / cm2. Then, the liquid crystal display cell of this invention can be obtained by hardening at 90-140 degreeC for 1-2 hours. Alternatively, in the present invention, after the gap is formed, the liquid crystal display cell of the present invention can be obtained by curing at 90 to 140 ° C. for 1 to 2 hours without ultraviolet irradiation. Examples of the spacer include glass fiber, silica beads, polymer beads and the like. 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.

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

[Example 1]
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, photoinitiator KAYACURE
RPI-4 (Nippon Kayaku Co., Ltd .; reaction product of 2-isocyanatoethyl methacrylate and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methylpropan-1-one) 5 parts by weight and 1.5 parts by weight of a silane coupling agent Silaace S-510 (manufactured by Chisso Corporation; 3-glycidoxypropyltrimethoxysilane) were mixed to obtain a resin liquid. Next, 17.5 parts by weight of Nanotech Alumina SPC (Cai Kasei Co., Ltd .; spherical alumina, average particle size 50 nm) as filler, butadiene / alkyl methacrylate / styrene copolymer (Rohm and Haas Co., Ltd .; Paraloid EXL-2655) ) 3 parts by weight are uniformly mixed with a bead mill, and further finely pulverized isophthalic acid dihydrazide (manufactured by Otsuka Chemical Co., Ltd .; IDH-S is pulverized with a jet mill to an average particle size of 1.5 μm and a maximum particle size of 5 μm) 7.55 parts by weight, tris (2-carboxyethyl) isocyanurate pulverized product (manufactured by Shikoku Kasei Kogyo Co., Ltd .: CIC acid finely pulverized with a jet mill to an average particle size of 1.5 μm and a maximum particle size of 5 μm) 3 weights The liquid crystal sealant of the present invention was obtained by kneading the part with a mixed three roll. The viscosity (25 ° C.) of the liquid crystal sealant was 340 Pa · s (25 ° C., R-type viscometer (manufactured by Toki Sangyo Co., Ltd.)).

[Example 2]
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, photoinitiator KAYACURE
RPI-4 (Nippon Kayaku Co., Ltd .; reaction product of 2-isocyanatoethyl methacrylate and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methylpropan-1-one) 5 parts by weight and 1.5 parts by weight of a silane coupling agent Silaace S-510 (manufactured by Chisso Corporation; 3-glycidoxypropyltrimethoxysilane) were mixed to obtain a resin liquid. Next, 17.5 parts by weight of Nanotech Alumina SPC (Cai Kasei Co., Ltd .; spherical alumina, average particle size 50 nm) as filler, butadiene / alkyl methacrylate / styrene copolymer (Rohm and Haas Co., Ltd .; Paraloid EXL-2655) ) 3 parts by weight are uniformly mixed with a bead mill, and further finely pulverized isophthalic acid dihydrazide (manufactured by Otsuka Chemical Co., Ltd .; IDH-S is pulverized with a jet mill to an average particle size of 1.5 μm and a maximum particle size of 5 μm) 7.55 parts by weight, tris (2-carboxypropyl) isocyanurate pulverized product (manufactured by Shikoku Kasei Kogyo Co., Ltd .: C3-CIC acid finely pulverized with a jet mill to an average particle size of 1.5 μm and a maximum particle size of 5 μm) 3 parts by weight was mixed and kneaded by a three roll to obtain the liquid crystal sealant of the present invention. The viscosity (25 ° C.) of the liquid crystal sealant was 380 Pa · s (25 ° C., R-type viscometer (manufactured by Toki Sangyo Co., Ltd.)).

[Example 3]
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, photoinitiator KAYACURE
RPI-4 (Nippon Kayaku Co., Ltd .; reaction product of 2-isocyanatoethyl methacrylate and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methylpropan-1-one) 5 parts by weight and 1.5 parts by weight of a silane coupling agent Silaace S-510 (manufactured by Chisso Corporation; 3-glycidoxypropyltrimethoxysilane) were mixed to obtain a resin liquid. Next, 17.5 parts by weight of Nanotech Alumina SPC (Cai Kasei Co., Ltd .; spherical alumina, average particle size 50 nm) as filler, butadiene / alkyl methacrylate / styrene copolymer (Rohm and Haas Co., Ltd .; Paraloid EXL-2655) ) 3 parts by weight were mixed uniformly with a bead mill, and further finely pulverized adipic acid dihydrazide (manufactured by Otsuka Chemical Co., Ltd .; ADH-S pulverized to a mean particle size of 1.5 μm and maximum particle size of 5 μm with a jet mill) 7 parts by weight, Tris (
2-Carboxyethyl) isocyanurate pulverized product (manufactured by Shikoku Kasei Kogyo Co., Ltd .: CIC acid finely pulverized to a mean particle size of 1.5 μm and maximum particle size of 5 μm with a jet mill) Thus, a liquid crystal sealant of the present invention was obtained. The viscosity (25 ° C.) of the liquid crystal sealant was 320 Pa · s (25 ° C., R-type viscometer (manufactured by Toki Sangyo Co., Ltd.)).

[Example 4]
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, photoinitiator KAYACURE
RPI-4 (Nippon Kayaku Co., Ltd .; reaction product of 2-isocyanatoethyl methacrylate and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methylpropan-1-one) 5 parts by weight and 1.5 parts by weight of a silane coupling agent Silaace S-510 (manufactured by Chisso Corporation; 3-glycidoxypropyltrimethoxysilane) were mixed to obtain a resin liquid. Next, 17.5 parts by weight of Nanotech Alumina SPC (Cai Kasei Co., Ltd .; spherical alumina, average particle size 50 nm) as filler, butadiene / alkyl methacrylate / styrene copolymer (Rohm and Haas Co., Ltd .; Paraloid EXL-2655) ) 3 parts by weight were mixed uniformly with a bead mill, and further finely pulverized adipic acid dihydrazide (manufactured by Otsuka Chemical Co., Ltd .; ADH-S pulverized to a mean particle size of 1.5 μm and maximum particle size of 5 μm with a jet mill) 7 parts by weight, tris (2-carboxypropyl) isocyanurate pulverized product (manufactured by Shikoku Kasei Kogyo Co., Ltd .: C3-CIC acid finely pulverized with a jet mill to an average particle size of 1.5 μm and a maximum particle size of 5 μm) 1 weight The liquid crystal sealant of the present invention was obtained by mixing the parts and kneading them with three rolls. The viscosity (25 ° C.) of the liquid crystal sealant was 350 Pa · s (25 ° C., R-type viscometer (manufactured by Toki Sangyo Co., Ltd.)).

[Comparative Example 1]
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, photoinitiator KAYACURE
RPI-4 (Nippon Kayaku Co., Ltd .; reaction product of 2-isocyanatoethyl methacrylate and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methylpropan-1-one) 5 parts by weight and 1.5 parts by weight of a silane coupling agent Silaace S-510 (manufactured by Chisso Corporation; 3-glycidoxypropyltrimethoxysilane) were mixed to obtain a resin liquid. Next, 17.5 parts by weight of Nanotech Alumina SPC (Cai Kasei Co., Ltd .; spherical alumina, average particle size 50 nm) as filler, butadiene / alkyl methacrylate / styrene copolymer (Rohm and Haas Co., Ltd .; Paraloid EXL-2655) ) 3 parts by weight are uniformly mixed with a bead mill, and further finely pulverized isophthalic acid dihydrazide (manufactured by Otsuka Chemical Co., Ltd .; IDH-S is pulverized with a jet mill to an average particle size of 1.5 μm and a maximum particle size of 5 μm) 7.55 parts by weight were kneaded with a three roll to obtain the liquid crystal sealant of the present invention. The viscosity (25 ° C.) of the liquid crystal sealant was 320 Pa · s (25 ° C., R-type viscometer (manufactured by Toki Sangyo Co., Ltd.)).

[Comparative Example 2]
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, photoinitiator KAYACURE
RPI-4 (Nippon Kayaku Co., Ltd .; reaction product of 2-isocyanatoethyl methacrylate and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl] -2-methylpropan-1-one) 5 parts by weight and 1.5 parts by weight of a silane coupling agent Silaace S-510 (manufactured by Chisso Corporation; 3-glycidoxypropyltrimethoxysilane) were mixed to obtain a resin liquid. Next, 17.5 parts by weight of Nanotech Alumina SPC (Cai Kasei Co., Ltd .; spherical alumina, average particle size 50 nm) as filler, butadiene / alkyl methacrylate / styrene copolymer (Rohm and Haas Co., Ltd .; Paraloid EXL-2655) ) 3 parts by weight were mixed uniformly with a bead mill, and further finely pulverized adipic acid dihydrazide (manufactured by Otsuka Chemical Co., Ltd .; ADH-S pulverized to a mean particle size of 1.5 μm and maximum particle size of 5 μm with a jet mill) Seven parts by weight were kneaded with a three-roll to obtain the liquid crystal sealant of the present invention. The viscosity (25 ° C.) of the liquid crystal sealant was 300 Pa · s (25 ° C., R-type viscometer (manufactured by Toki Sangyo Co., Ltd.)).

  Table 1 shows the composition table of the liquid crystal sealants described in Examples 1 to 4 and Comparative Examples 1 and 2.

[Liquid crystal contamination (UV irradiation and thermal curing)]
Add 0.5g of liquid crystal sealant to the sample bottle, add 1g of liquid crystal (MLC-6866-100, manufactured by Merck & Co.), irradiate 3000mJ / cm2 ultraviolet rays with UV irradiator and put into 120 ° C oven for 1 hour. did. 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 2 (liquid crystal contamination (UV irradiation and thermosetting): elution amount (ppm)).

[Liquid crystal contamination (heat 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 3 (liquid crystal contamination (thermosetting only): elution amount (ppm))

[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 sealing agent 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 sealing agent, and irradiated with 3 J / cm 2 of ultraviolet rays by a UV irradiator, and then placed in an oven. It was charged and heat cured. 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 4.

[Pot life]
The viscosity change at 25 ° C. of the obtained liquid crystal sealant was measured. Table 4 shows the rate of increase in viscosity (%) relative to the initial viscosity.

[Preparation of liquid crystal cell for evaluation (liquid crystal dropping method combined with photothermal)]
An alignment film solution (PIA-5540-05A; manufactured by Chisso Corporation) was applied to a substrate with a transparent electrode, baked, and rubbed. A seal pattern and a dummy seal pattern were formed with a dispenser so that the line width after bonding the liquid crystal sealants of Examples and Comparative Examples to 1 mm on this substrate, and then liquid crystal (JC-5015LA; manufactured by Chisso Corporation) Minute droplets were dropped into the frame of the seal pattern. Furthermore, an in-plane spacer (NATOCO SPACER KSEB-525F; manufactured by NATCO; gap width of 5 μm after bonding) is sprayed and thermally fixed on another rubbing-treated substrate, and the substrate is first vacuumed using a bonding apparatus. It was bonded to a liquid crystal dripped substrate. After opening to the atmosphere and forming a gap, the metal seal lamp (manufactured by Ushio Electric Co., Ltd.) was applied to the sealant part at 3 J / cm2 (100 mW / cm2).
For 30 seconds). Furthermore, it put into 120 degreeC oven and heat-cured for 1 hour, and produced the liquid crystal test cell for evaluation.

[Production of liquid crystal cell for evaluation (thermosetting liquid crystal dropping method)]
An alignment film solution (PIA-5540-05A; manufactured by Chisso Corporation) was applied to a substrate with a transparent electrode, baked, and rubbed. A seal pattern and a dummy seal pattern were formed with a dispenser so that the line width after bonding the liquid crystal sealants of Examples and Comparative Examples to 1 mm on this substrate, and then liquid crystal (JC-5015LA; manufactured by Chisso Corporation) Minute droplets were dropped into the frame of the seal pattern. Furthermore, an in-plane spacer (NATOCO SPACER KSEB-525F; manufactured by NATCO; gap width of 5 μm after bonding) is sprayed and thermally fixed on another rubbing-treated substrate, and the substrate is first vacuumed using a bonding apparatus. It was bonded to a liquid crystal dripped substrate. After forming the gap by opening to the atmosphere, it was put in an oven at 120 ° C. as it was without UV curing, and was cured by heating for 1 hour to prepare an evaluation liquid crystal test cell.

Table 5 shows the results of observation of the seal shape and liquid crystal alignment disorder of the prepared liquid crystal cell for evaluation with a polarizing microscope. Evaluation was made in the following four stages.
○ (There is no alignment disorder near the seal)
Δ (Slightly disturbed orientation near the seal)
× (Liquid crystal is inserted into the seal, or there is an alignment disorder near the seal)
XX (Seal breaks and cells cannot be formed)

  As shown in Tables 2 and 3, the liquid crystal sealants of Examples and Comparative Examples according to the present invention are both liquid crystal sealants with low liquid crystal contamination. As shown in Table 4, it can be seen that the liquid crystal sealants of the examples have higher adhesive strength than the comparative examples even at low temperature curing (100 ° C. × 1 hour), and are excellent in low temperature curability. It can also be seen that the pot life is comparable to the comparative example. From Table 5, it can be seen that the liquid crystal sealants of the examples can form cells by a thermosetting liquid crystal dropping method, which was impossible with the liquid crystal sealants of the comparative examples, and there is little contamination near the seal.

  The liquid crystal sealing agent of the present invention is particularly excellent in low-temperature curability, and at the same time has low liquid crystal contamination and a long pot life, and has excellent coating workability, bonding properties, and adhesive strength on a substrate. 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.

Claims (8)

(A) a dihydrazide compound, (b) one or more selected from epoxy resins, (meth) acrylated epoxy resins and partially (meth) acrylated epoxy resins as a curable resin, and (c) a curing accelerator A liquid crystal sealant comprising a polycarboxylic acid compound having an isocyanuric ring skeleton represented by the following general formula (1) as:

[Wherein T1 to T3 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 curable resin (b) is a mixture of an epoxy resin and a (meth) acrylated epoxy resin. (C) The liquid-crystal sealing compound of Claim 1 or 2 whose hardening accelerator is a compound represented by following formula (3).

(C) The liquid-crystal sealing compound of Claim 1 or 2 whose hardening accelerator is a compound represented by following formula (4).

A liquid crystal display cell sealed with a cured product of the liquid crystal sealant according to claim 1. In a liquid crystal display cell constituted by two substrates, a seal pattern is formed on one substrate using the liquid crystal sealant according to any one of claims 1 to 4, and a liquid crystal is formed in the seal pattern or on a counter substrate. A method of manufacturing a liquid crystal display cell, wherein the counter substrate is bonded to the substrate and then cured. The manufacturing method of the liquid crystal display cell of Claim 6 which performs secondary curing by heating through primary curing by ultraviolet rays and / or visible light. The manufacturing method of the liquid crystal display cell of Claim 6 which cures only by heating, without passing through the hardening by an ultraviolet-ray and / or visible light.