JP6497809B2 - Liquid crystal sealant and liquid crystal display cell using the same - Google Patents

Description

  The present invention relates to a liquid crystal sealant that is cured by light and heat, and relates to a liquid crystal sealant used in a liquid crystal dropping method. More specifically, the present invention relates to a liquid crystal sealant for a liquid crystal dropping method that has extremely low wiring corrosivity after a moisture resistance test and is excellent in general characteristics such as low liquid crystal contamination and adhesive strength.

  With the recent increase in size of liquid crystal display cells, a so-called liquid crystal dropping method with higher mass productivity has been proposed as a method for manufacturing liquid crystal display cells (see Patent Document 1 and Patent Document 2). Specifically, it is a method of manufacturing a liquid crystal display cell in which liquid crystal is sealed by dropping a liquid crystal inside a weir of a liquid crystal sealant formed on one substrate and then bonding the other substrate.

  However, in the liquid crystal dropping method, the liquid crystal sealant in an uncured state comes into contact with the liquid crystal. At that time, the components of the liquid crystal sealant are dissolved (eluting) in the liquid crystal to reduce the resistance value of the liquid crystal, There is a problem that a display defect occurs.

In order to solve this problem, a photothermal combination type liquid crystal sealant for a liquid crystal dropping method is currently used and put into practical use (Patent Documents 3 and 4). The liquid crystal dropping method using the liquid crystal sealant is characterized in that the liquid crystal sealant sandwiched between the substrates is irradiated with light to be primarily cured and then heated to be secondarily cured. According to this method, the uncured liquid crystal sealant can be quickly cured by light, and dissolution (elution) of the liquid crystal sealant component into the liquid crystal can be suppressed. Furthermore, the problem of insufficient adhesive strength due to curing shrinkage, etc. during photocuring also occurs with photocuring alone, but if it is a photothermal combination type, the effect of stress relaxation can be obtained by secondary curing by heating, and such problems can be solved Have
With the practical application of this photothermographic liquid crystal sealing agent for liquid crystal dropping method, the liquid crystal dropping method has become a commonly used method.

Due to the practical application of the liquid crystal dropping method, even a large liquid crystal display cell can be easily manufactured. As a result, the liquid crystal display has been popularized.
On the other hand, this liquid crystal dropping method may have a defect in the quality of the manufactured liquid crystal display cell. One of them is a problem that causes defects in driving of liquid crystal after moisture resistance reliability. This problem has occurred even in a liquid crystal display cell manufactured by a conventional liquid crystal injection method, but is particularly noticeable in a liquid crystal display cell manufactured by a liquid crystal dropping method. Various solutions have been made to solve this problem. For example, the reaction rate is improved by adding a thermal radical polymerization initiator or a curing accelerator, or a material having low solubility in liquid crystals is used as a constituent component.
However, these studies have not yet achieved a liquid crystal sealing agent for a liquid crystal dropping method that sufficiently solves the above problems.

JP-A 63-179323 JP-A-10-239694 Japanese Patent No. 3583326 JP 2004-61925 A JP 2004-126211 A JP 2009-8754 A International Publication No. 2008/004455

  The present invention relates to a liquid crystal sealing agent for a liquid crystal dropping method which is cured by light and heat, and has extremely low wiring corrosion after a moisture resistance test, and also in general characteristics such as low liquid crystal contamination and adhesive strength. In order to be excellent, the present invention proposes a liquid crystal sealing agent for a liquid crystal dropping method that realizes high definition, high speed response, low voltage drive, and long life of a liquid crystal display element.

As a result of intensive investigations to solve the problem of the driving defect, the present inventors are due to wiring corrosion after the moisture resistance test, and the wiring corrosion reduces the photoreactivity of the liquid crystal sealant as much as possible. And it discovered that it could solve by raising the content rate of an inorganic filler, and came to this invention.
That is, the present invention relates to the following 1) to 10). In this specification, “(meth) acryl” means “acryl” and / or “methacryl”. The “liquid crystal sealant for liquid crystal dropping method” may be simply referred to as “liquid crystal sealant”.

1)
(A) a radical curable compound, (B) a photo radical polymerization initiator and (C) an inorganic filler,
The component (B) radical photopolymerization initiator has a molar extinction coefficient at 365 nm of less than 50 mL / g · cm, and the content ratio of component (B) to component (A) (content of component (B) / ( A) content of component) is 0.05 or less,
(C) The liquid crystal sealing agent for liquid crystal dropping methods whose content rate in the liquid crystal sealing agent total amount of an inorganic filler is 20 mass% or more.
2)
Furthermore, (D) Liquid crystal sealing agent for liquid crystal dropping methods as described in said 1) containing a thermal radical polymerization initiator.
3)
The above component 1) wherein the component (D) thermal radical polymerization initiator is a thermal radical polymerization initiator containing no oxygen-oxygen bond (—O—O—) and nitrogen-nitrogen bond (—N═N—) in the molecule. Or the liquid-crystal sealing compound for liquid crystal dropping methods as described in 2).
4)
The liquid crystal sealing agent for a liquid crystal dropping method according to any one of 1) to 3), wherein the component (A) radical curable compound is an epoxy (meth) acrylate compound.
5)
Furthermore, the liquid-crystal sealing compound for liquid crystal dropping methods as described in any one of said 1) thru | or 4) containing the curable compound (E) which has an epoxy group.
6)
Furthermore, (F) Liquid crystal sealing agent for liquid crystal dropping methods as described in any one of said 1) thru | or 5) containing a thermosetting agent.
7)
The liquid crystal sealing agent for liquid crystal dropping method according to 7) above, wherein the component (F) thermosetting agent is an organic acid hydrazide.
8)
Furthermore, (G) Liquid crystal sealing agent for liquid crystal dropping methods as described in any one of said 1) thru | or 7) containing a silane coupling agent.
9)
In a liquid crystal display cell constituted by two substrates, the liquid crystal was dropped inside the liquid crystal sealing agent weir of the liquid crystal dropping method according to any one of 1) to 8) formed on one substrate. Then, the other substrate is bonded, and then cured by light and / or heat.
10)
The liquid crystal display cell sealed with the hardened | cured material obtained by hardening | curing the liquid crystal sealing agent for liquid crystal dropping methods as described in any one of said 1) thru | or 8).

  The liquid crystal sealant for the liquid crystal dropping method of the present invention is extremely useful as a liquid crystal sealant for liquid crystal display elements because it can suppress wiring corrosion to the maximum and is excellent in low liquid crystal contamination and adhesive strength.

The liquid crystal sealing agent of the present invention contains (A) a radical curable compound.
The component (A) is not particularly limited as long as it undergoes a radical polymerization reaction by light or heat, and examples thereof include a curable compound having a (meth) acryloyl group and a curable compound having a vinyl group.
Examples of the curable compound having a (meth) acryloyl group include (meth) acrylic ester and epoxy (meth) acrylate. (Meth) acrylic esters include benzyl methacrylate, cyclohexyl methacrylate, glycerol dimethacrylate, glycerol triacrylate, EO-modified glycerol triacrylate, pentaerythritol acrylate, trimethylolpropane triacrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol. Examples include hexaacrylate and phloroglucinol triacrylate. Epoxy (meth) acrylate is obtained by a known method by a reaction between an epoxy compound and (meth) acrylic acid. Although it does not specifically limit as an epoxy compound used as a raw material, A bifunctional or more epoxy compound is preferable, for example, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a phenol novolac type epoxy compound , Cresol novolac type epoxy compound, bisphenol A novolak type epoxy compound, bisphenol F novolak type epoxy compound, alicyclic epoxy compound, aliphatic chain epoxy compound, glycidyl ester type epoxy compound, glycidyl amine type epoxy compound, hydantoin type epoxy compound , Isocyanurate type epoxy compounds, phenol novolac type epoxy compounds having a triphenolmethane skeleton, other catechols, resorcinols, etc. Diglycidyl ethers of ability phenols, bifunctional alcohols diglycidyl ethers of, and their halides, and the like hydrogenated product. Among these, an epoxy compound having a resorcin skeleton is preferable from the viewpoint of liquid crystal contamination, such as resorcin diglycidyl ether. 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.
Therefore, a preferable curable compound having a (meth) acryloyl group is a curable compound having a (meth) acryloyl group and further having a resorcin skeleton, such as an acrylic acid ester of resorcin diglycidyl ether or resorcin diglycidyl ether. Methacrylic acid ester.

  Content of the component (A) in the liquid-crystal sealing compound of this invention is 30-75 mass% normally, Preferably it is 40-65 mass%. In particular, when the epoxy compound and the (meth) acrylated epoxy compound are used in combination, the content of the epoxy compound in the component (A) is usually 3 to 30% by mass, preferably 5 to 20% by mass, and more preferably. It is 8-15 mass%.

The liquid crystal sealing agent of the present invention contains (B) a photoradical polymerization initiator, and the photoabsorption polymerization initiator has a molar extinction coefficient at 365 nm of less than 50 mL / g · cm.
Examples of photo radical polymerization initiators that satisfy this condition 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, camphorquinone, 9-fluorenone, diphenyldisulfide and the like can be mentioned. Specifically, IRGACURE ^RTM 651, 184, 2959, 127, 907, 369, 379EG, 819, 784, 754, 500, OXE01, OXE02, DAROCURE ^RTM 1173, LUCIRIN ^RTM TPO (all manufactured by BASF), Sequol ^RTM Z, BZ, BEE, BIP, BBI (all of which are manufactured by Seiko Chemical Co., Ltd.) and the like.
Moreover, it is preferable to use what has a (meth) acryl group in a molecule | numerator from a liquid crystal contamination viewpoint, for example, 2-methacryloyloxyethyl isocyanate and 1- [4- (2-hydroxyethoxy) -phenyl]- The reaction product with 2-hydroxy-2methyl-1-propan-1-one is preferably used. This compound can be obtained by the method described in International Publication No. 2006/027982.

  The content of the component (B) radical photopolymerization initiator that can be used in the liquid crystal sealant of the present invention is 0.05 or less in terms of the content ratio with respect to the component (A). By reducing the photoreactivity, the difference in the degree of cure between the light shielding part and the exposed part can be reduced, and as a result, the wiring corrosivity can be lowered. This content ratio is preferably 0.03 or less, and more preferably 0.025 or less. The content ratio of component (B) to component (A) is determined by the content of component (B) / content of component (A).

The liquid crystal sealing agent of the present invention contains (C) an inorganic filler.
Examples of the inorganic filler include silica, 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, molybdenum disulfide, asbestos, etc., preferably fused silica, crystalline silica, silicon nitride, boron nitride, calcium carbonate , Barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, calcium silicate, and aluminum silicate, with silica, alumina, and talc being preferred. These inorganic fillers may be used in combination of two or more.
If the average particle size of the inorganic filler is too large, 2000 nm or less is suitable, preferably 1000 nm or less, because it may cause failure such as inability to form a gap when the upper and lower glass substrates are bonded together during the production of a narrow gap liquid crystal cell. More preferably, it is 300 nm or less. Moreover, a preferable minimum is about 10 nm, More preferably, it is about 100 nm. The particle diameter can be measured by a laser diffraction / scattering particle size distribution analyzer (dry type) (manufactured by Seishin Enterprise Co., Ltd .; LMS-30).

The content of the component (C) inorganic filler in the total amount of the liquid crystal sealant is 20% by mass or more. Content of an inorganic filler further reduces wiring corrosivity by interaction with the said photocurability. The content of this component (C) is preferably 25% by mass or more, more preferably 30% by mass or more.
Moreover, the upper limit of the said content rate is about 70 mass%, Preferably it is 60 mass%.

The liquid-crystal sealing compound of this invention can aim at the improvement of a cure rate and a cure degree using (D) thermal radical polymerization initiator.
The thermal radical polymerization initiator is not particularly limited as long as it is a compound that generates radicals by heating and initiates a chain polymerization reaction, but there are organic peroxides, azo compounds, benzoin compounds, benzoin ether compounds, acetophenone compounds, benzopinacols, and the like. And benzopinacol is preferably used. For example, examples of the organic peroxide include Kayamek ^RTM A, M, R, L, LH, SP-30C, Parkadox CH-50L, BC-FF, Kadox B-40ES, Parkadox 14, Trigonox ^RTM 22-70E, 23-C70, 121, 121-50E, 121-LS50E, 21-LS50E, 42, 42LS, Kaya Ester ^RTM P-70, TMPO-70, CND-C70, OO-50E, AN, Kayabutyl ^RTM B, Parkardox 16 , Kayacaron ^RTM BIC-75, AIC-75 (manufactured by Kayaku Akzo Co., Ltd.), Permec ^RTM N, H, S, F, D, G, Perhexa ^RTM H, HC, Pat TMH, C, V, 22, MC, Percure ^RTM AH, AL, HB, Perbutyl ^RTM H, C, ND, L, Parkmill ^{RT M} H, D, Peroyl ^RTM IB, IPP, Perocta ^RTM ND, is available as such is a commercially available product (manufactured by NOF Co., Ltd.).

  Moreover, as an azo compound, VA-044, V-070, VPE-0201, VSP-1001 (made by Wako Pure Chemical Industries Ltd.), etc. are available as a commercial item. In the present specification, the superscript RTM means a registered trademark.

The component (D) is preferably a thermal radical polymerization initiator that does not have an oxygen-oxygen bond (—O—O—) or a nitrogen-nitrogen bond (—N═N—) in the molecule. A thermal radical polymerization initiator having an oxygen-oxygen bond (—O—O—) or a nitrogen-nitrogen bond (—N═N—) in the molecule emits a large amount of oxygen or nitrogen when a radical is generated. There exists a possibility that it hardens | cures in the state which left the bubble inside, and characteristics, such as adhesive strength, may be reduced. Particularly preferred are benzopinacol-based thermal radical polymerization initiators (including those obtained by chemically modifying benzopinacol). Specifically, benzopinacol, 1,2-dimethoxy-1,1,2,2-tetraphenylethane, 1,2-diethoxy-1,1,2,2-tetraphenylethane, 1,2-diphenoxy- 1,1,2,2-tetraphenylethane, 1,2-dimethoxy-1,1,2,2-tetra (4-methylphenyl) ethane, 1,2-diphenoxy-1,1,2,2-tetra (4-methoxyphenyl) ethane, 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane, 1,2-bis (triethylsiloxy) -1,1,2,2-tetraphenyl Ethane, 1,2-bis (t-butyldimethylsiloxy) -1,1,2,2-tetraphenylethane, 1-hydroxy-2-trimethylsiloxy-1,1,2,2-tetraphenylethane, 1- Hydroxy-2-trie Lucyloxy-1,1,2,2-tetraphenylethane, 1-hydroxy-2-t-butyldimethylsiloxy-1,1,2,2-tetraphenylethane and the like can be mentioned, and preferably 1-hydroxy-2 -Trimethylsiloxy-1,1,2,2-tetraphenylethane, 1-hydroxy-2-triethylsiloxy-1,1,2,2-tetraphenylethane, 1-hydroxy-2-t-butyldimethylsiloxy-1 1,2,2-tetraphenylethane, 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane, more preferably 1-hydroxy-2-trimethylsiloxy-1,1. 2,2-tetraphenylethane, 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane, particularly preferably 1,2-biphenyl. It is (trimethylsiloxy) 1,1,2,2-phenylethane.
The benzopinacol is commercially available from Tokyo Chemical Industry Co., Ltd., Wako Pure Chemical Industries, Ltd. Moreover, etherification of the hydroxy group of benzopinacol can be easily synthesized by a known method. Moreover, silyl etherification of the hydroxy group of benzopinacol can be obtained by synthesizing by a method in which the corresponding benzopinacol and various silylating agents are heated under a basic catalyst such as pyridine. Examples of silylating agents include trimethylchlorosilane (TMCS), hexamethyldisilazane (HMDS), N, O-bis (trimethylsilyl) trifluoroacetamide (BSTFA) and triethylsilylating agents, which are generally known trimethylsilylating agents. Examples of triethylchlorosilane (TECS) and t-butyldimethylsilylating agent include t-butylmethylsilane (TBMS). These reagents can be easily obtained from markets such as silicon derivative manufacturers. The reaction amount of the silylating agent is preferably 1.0 to 5.0 times mol for 1 mol of the hydroxy group of the target compound. More preferably, it is 1.5-3.0 times mole. When the amount is less than 1.0 times mol, the reaction efficiency is poor and the reaction time is prolonged, so that thermal decomposition is promoted. When the amount is more than 5.0 times mol, separation may be deteriorated during collection or purification may be difficult.

  It is preferable that the component (D) has a fine particle size and is uniformly dispersed. The average particle size is preferably 5 μm or less, more preferably 3 μm or less, because if the average particle size is too large, it becomes a cause of defects such as inability to successfully form a gap when the upper and lower glass substrates are bonded together during the production of a narrow gap liquid crystal display cell. . Moreover, although it does not matter even if it makes it infinitely small, usually a minimum is about 0.1 micrometer. The particle size can be measured by a laser diffraction / scattering particle size distribution analyzer (dry type) (manufactured by Seishin Enterprise Co., Ltd .; LMS-30).

  As content of a component (D), it is preferable that it is 0.0001-10 mass% in the total amount of a liquid-crystal sealing compound, More preferably, it is 0.0005-5 mass%, 0.001-3 mass%. Is particularly preferred.

The liquid crystal sealant of the present invention may further contain (E) a curable compound having an epoxy group, if necessary. Examples of the curable compound having an epoxy group include a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a phenol novolac type epoxy compound, a cresol novolac type epoxy compound, and a bisphenol A novolak type epoxy. Compound, bisphenol F novolac type epoxy compound, alicyclic epoxy compound, aliphatic chain epoxy compound, glycidyl ester type epoxy compound, hydantoin type epoxy compound, isocyanurate type epoxy compound, phenol novolac type epoxy compound having triphenolmethane skeleton , Other diglycidyl ethers of difunctional phenols, diglycidyl ethers of difunctional alcohols, and their halogenated compounds , Like hydrogenated product.
When using a component (E), it is preferable that it is 1-20 mass% in the total amount of a liquid-crystal sealing compound, More preferably, it is 1-15 mass%.

The liquid crystal sealing agent of the present invention may contain (F) a thermosetting agent.
The thermosetting agent means a thermosetting agent that does not generate radicals by heating, unlike the component (D) thermal radical polymerization initiator. Specifically, it reacts nucleophilically with an unshared electron pair or an anion in the molecule, and examples thereof include polyvalent amines, polyhydric phenols, and organic acid hydrazide compounds. However, it is not limited to these. Of these, organic acid hydrazide compounds are particularly preferably used. For example, the aromatic hydrazide terephthalic acid dihydrazide, isophthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 2,6-pyridinedihydrazide, 1,2,4-benzenetrihydrazide, 1,4,5,8-naphthoic acid Examples thereof include tetrahydrazide and pyromellitic acid tetrahydrazide. Examples of aliphatic hydrazide compounds include form hydrazide, acetohydrazide, propionic acid hydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, sebacic acid dihydrazide. 1,4-cyclohexanedihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, iminodiacetic acid dihydrazide, N, N'-hexamethylenebissemicarbazide, citric acid trihydrazide, nitriloacetic acid trihydrazide, cyclohexanetricarboxylic acid trihydrazide, 1,3-bis ( Hydantoin skeleton such as hydrazinocarbonoethyl) -5-isopropylhydantoin, preferably valine hydantoin skeleton (where the carbon atom of the hydantoin ring is iso Dihydrazide compounds having a skeleton substituted with a propyl group), tris (1-hydrazinocarbonylmethyl) isocyanurate, tris (2-hydrazinocarbonylethyl) isocyanurate, tris (1-hydrazinocarbonylethyl) isocyanurate, tris (3-hydrazinocarbonylpropyl) isocyanurate, bis (2-hydrazinocarbonylethyl) isocyanurate and the like can be mentioned. Preferably, from the balance of curing reactivity and latency, isophthalic acid dihydrazide, malonic acid dihydrazide, adipic acid dihydrazide, tris (1-hydrazinocarbonylmethyl) isocyanurate, tris (1-hydrazinocarbonylethyl) isocyanurate, tris ( 2-Hydrazinocarbonylethyl) isocyanurate and tris (3-hydrazinocarbonylpropyl) isocyanurate, particularly preferably tris (2-hydrazinocarbonylethyl) isocyanurate.
A component (H) may be used independently and may mix 2 or more types. In the liquid crystal sealing agent of the present invention, when component (F) is used, it is usually 0.1 to 10% by mass, preferably 1 to 5% by mass in the total amount of the liquid crystal sealing agent.

The liquid crystal sealant of the present invention can be improved in adhesion strength and moisture resistance by adding a silane coupling agent as the component (G).
As component (G), 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltri Methoxysilane, 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-methacryloxypropyltrimethoxysilane, 3-chloropropyl Chill dimethoxysilane, 3-chloropropyl trimethoxy silane, and the like. Since these silane coupling agents are sold by Shin-Etsu Chemical Co., Ltd. as KBM series, KBE series, etc., they are easily available from the market. In the liquid crystal sealing agent of the present invention, when component (G) is used, 0.05 to 3% by mass is preferable in the total amount of the liquid crystal sealing agent.

If necessary, the liquid crystal sealant of the present invention may further contain additives such as curing accelerators such as organic acids and imidazoles, radical polymerization inhibitors, pigments, leveling agents, antifoaming agents and solvents. .
Examples of the curing accelerator include organic acids and imidazoles.
Examples of the organic acid include organic carboxylic acids and organic phosphoric acids, but organic carboxylic acids are preferred. Specifically, aromatic carboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, benzophenone tetracarboxylic acid, furandicarboxylic acid, succinic acid, adipic acid, dodecanedioic acid, sebacic acid, thiodipropionic acid , Cyclohexanedicarboxylic acid, tris (2-carboxymethyl) isocyanurate, tris (2-carboxyethyl) isocyanurate, tris (2-carboxypropyl) isocyanurate, bis (2-carboxyethyl) isocyanurate and the like. .
Examples of imidazole compounds include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, and 1-benzyl. 2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 2,4-diamino-6 (2′-methylimidazole (1 ′ )) Ethyl-s-triazine, 2,4-diamino-6 (2′-undecylimidazole (1 ′)) ethyl-s-triazine, 2,4-diamino-6 (2′-ethyl-4-methylimidazole) (1 ′)) Ethyl-s-triazine, 2,4-diamino-6 (2′- Methylimidazole (1 ′)) ethyl-s-triazine isocyanuric acid adduct, 2-methylimidazole isocyanuric acid 2: 3 adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethyl Examples include imidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, and 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole.
In the liquid crystal sealant of the present invention, when a curing accelerator is used, it is usually 0.1 to 10% by mass, preferably 1 to 5% by mass, based on the total amount of the liquid crystal sealant.

The radical polymerization inhibitor is not particularly limited as long as it is a compound that prevents polymerization by reacting with radicals generated from a photopolymerization initiator, a thermal radical polymerization initiator, etc., and is not limited to quinone, piperidine, hinders. A dophenol type, a nitroso type, etc. can be used. Specifically, naphthoquinone, 2-hydroxynaphthoquinone, 2-methylnaphthoquinone, 2-methoxynaphthoquinone, 2,2,6,6, -tetramethylpiperidine-1-oxyl, 2,2,6,6, -tetramethyl -4-hydroxypiperidine-1-oxyl, 2,2,6,6, -tetramethyl-4-methoxypiperidine-1-oxyl, 2,2,6,6, -tetramethyl-4-phenoxypiperidine-1- Oxyl, hydroquinone, 2-methylhydroquinone, 2-methoxyhydroquinone, parabenzoquinone, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, 2,6-di-t-butylcresol, stearyl β -(3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2'-methylene (4-ethyl-6-tert-butylphenol), 4,4′-thiobis-3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 3 , 9-bis [1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl], 2,4,8,10-tetraoxaspiro [ 5,5] undecane, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenylpropionate) methane, 1,3,5-tris (3 ′, 5′- Di-t-butyl-4′-hydroxybenzyl) -sec-triazine-2,4,6- (1H, 3H, 5H) trione, paramethoxyphenol, 4-methoxy-1-naphthol, thiodiphenylamine, N-nitroso Examples include, but are not limited to, an aluminum salt of phenylhydroxyamine, trade name ADK STAB LA-81, trade name ADK STAB LA-82 (manufactured by Adeka Corporation), and the like. Of these, naphthoquinone, hydroquinone, and nitroso piperazine radical polymerization inhibitors are preferred, and naphthoquinone, 2-hydroxynaphthoquinone, hydroquinone, 2,6-di-tert-butyl-P-cresol, Polystop 7300P (Hakuto Co., Ltd.) Company-made) is more preferred, and Polystop 7300P (made by Hakuto Co., Ltd.) is most preferred.
The content of the radical polymerization inhibitor is preferably 0.0001 to 1% by mass, more preferably 0.001 to 0.5% by mass, and 0.01 to 0.2% by mass in the total amount of the liquid crystal sealant of the present invention. Is particularly preferred.

  An example of a method for obtaining the liquid crystal sealant of the present invention is the following method. First, the (A) component, the (C) component, and, if necessary, the (E) component are dissolved by heating. Next, after cooling to room temperature, component (C) is added, and further, (D) component, (F) component, (G) component and antifoaming agent, leveling agent, solvent, etc. are added as necessary. For example, the liquid crystal sealant of the present invention can be produced by uniformly mixing with a three-roll, sand mill, ball mill or the like and filtering with a metal mesh.

The liquid crystal display cell of the present invention is a cell in which a pair of substrates having predetermined electrodes formed on a 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. is there. The kind of liquid crystal to be sealed is not particularly limited. Here, the substrate is composed of a combination of substrates made of at least one of glass, quartz, plastic, silicon, etc. and having light transmission properties. As a manufacturing method thereof, 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 to one of the pair of substrates using a dispenser or a screen printing device. Then, if necessary, temporary curing is performed at 80 to 120 ° C. Thereafter, a liquid crystal is dropped inside the weir of the liquid crystal sealant, and the other glass substrate is overlaid in a vacuum to create a gap. After forming the gap, the liquid crystal display cell of the present invention can be obtained by curing at 90 to 130 ° C. for 1 to 2 hours. When used as a photothermal combination type, the liquid crystal sealant is irradiated with ultraviolet rays by an ultraviolet irradiator and photocured. The ultraviolet irradiation amount is preferably 500 to 10000 mJ / cm ² , more preferably 1000 to 6000 mJ / cm ² . Then, if necessary, the liquid crystal display cell of the present invention can be obtained by curing at 90 to 130 ° C. for 1 to 2 hours. 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. 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% by mass, preferably 0.5 to 2% by mass, and more preferably about 0.9 to 1.5% by mass with respect to 100% by mass of the liquid crystal sealant of the present invention. is there.

  The liquid crystal sealant of the present invention has an effect of reducing wiring corrosion. As a result, driving defects after the moisture resistance test can be eliminated. Moreover, it is excellent also in low liquid-crystal stain | contamination property, and also the cured | curing material is excellent also in various hardened | cured material characteristics, such as adhesive strength and heat resistance. As described above, a liquid crystal display cell having excellent reliability can be realized by using the liquid crystal sealing agent of the present invention. In addition, the liquid crystal display cell prepared using the liquid crystal sealant of the present invention satisfies the characteristics required for a liquid crystal display cell having a high voltage holding ratio and a low ion density.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to an Example. Unless otherwise specified, “part” and “%” in the text are based on mass.
[Synthesis Example 1]
[Synthesis of total acrylate of resorcin diglycidyl ether]
[Process 1]
To a flask equipped with a thermometer, a dropping funnel, a condenser, and a stirrer, 5500 g of resorcin, 37000 g of epichlorohydrin and 500 g of tetramethylammonium chloride were dissolved under stirring, and the temperature was raised to 70 ° C. Next, after adding 4000 g of flaky sodium hydroxide over 100 minutes, a post-reaction was further performed at 70 ° C. for 1 hour. After completion of the reaction, 15000 g of water was added and washed, and then excess epichlorohydrin and the like were distilled off from the oil layer at 130 ° C. under reduced pressure. To the residue, 22200 g of methyl isobutyl ketone was added and dissolved, and the temperature was raised to 70 ° C. Under stirring, 1000 g of 30% aqueous sodium hydroxide solution was added and the reaction was carried out for 1 hour, followed by washing with water 5550 g three times, and distilling off methyl isobutyl ketone at 180 ° C. under reduced pressure to obtain 10550 g of resorcin diglycidyl ether. It was. The epoxy equivalent of the obtained epoxy resin was 129 g / eq.
[Process 2]
181.2 g of resorcin diglycidyl ether obtained in Synthesis Example 1 was dissolved in 266.8 g of toluene, and 0.8 g of dibutylhydroxytoluene was added as a polymerization inhibitor, and the temperature was raised to 60 ° C. Thereafter, 117.5 g of acrylic acid having 100% equivalent of epoxy group was added, and the temperature was further raised to 80 ° C., and 0.6 g of trimethylammonium chloride as a reaction catalyst was added thereto, followed by stirring at 98 ° C. for about 30 hours. The obtained reaction liquid was washed with water and toluene was distilled off to obtain 253 g of an acrylic ester product of the desired resorcin diglycidyl ether.
[Synthesis Example 2]
[Synthesis of 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane]
100 parts (0.28 mol) of commercially available benzopinacol (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 350 parts of dimethylformaldehyde. To this were added 32 parts (0.4 mol) of pyridine as a base catalyst and 150 parts (0.58 mol) of BSTFA (manufactured by Shin-Etsu Chemical Co., Ltd.) as a silylating agent, and the mixture was heated to 70 ° C. and stirred for 2 hours. The obtained reaction solution was cooled and stirred while adding 200 parts of water to precipitate the product and deactivate the unreacted silylating agent. The precipitated product was separated by filtration and thoroughly washed with water. Subsequently, the obtained product was dissolved in acetone, recrystallized by adding water and purified. 105.6 parts (yield 88.3%) of the desired 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane were obtained.
As a result of analysis by HPLC (high performance liquid chromatography), the purity was 99.0% (area percentage).

[Preparation of Examples 1-3 and Comparative Examples 1-4]
Photoradical polymerization initiator (component (B)) was added to the radical curable compound (component (A)) such as the compound synthesized in Synthesis Example 1 at the ratio shown in Table 1 below, and dissolved by heating at 90 ° C. Cool to room temperature, add thermal radical polymerization initiator (component (D)), silane coupling agent (component (G)), thermosetting agent (component (F)), inorganic filler (component (C)), etc. After stirring, the mixture was dispersed with a three-roll mill and filtered with a metal mesh (635 mesh) to prepare liquid crystal dropping method sealing agents (Examples 1 to 3, Comparative Examples 1 to 4).

[Measurement of glass transition temperature]
The liquid crystal sealant produced in Examples and Comparative Examples was sandwiched between polyethylene terephthalate (PET) films to form a thin film having a thickness of 100 μm, and a metal halide lamp (manufactured by Ushio Inc.) was used at 3000 mJ / cm 2 (100 mW / cm 2 for 30 seconds). ) Was irradiated for 40 minutes in an oven at 130 ° C. for curing. After curing, the PET film was peeled off to obtain a cured sealant film, which was then cut into a 50 mm × 5 mm strip to obtain a sample piece. This sample piece was measured in a tensile mode of a dynamic viscoelasticity measuring apparatus (DMS-6100: manufactured by SII Nano Technology) under the conditions of a frequency of 10 Hz and a temperature rising temperature of 3 ° C./min, and the obtained loss factor The temperature at which Tan δ was the maximum was taken as the glass transition temperature.

[Moisture permeability measurement]
A cured sealant film was prepared by the same method as the glass transition temperature measurement method, and cut into a 90 mm × 90 mm square to obtain a sample piece. This sample piece was measured for moisture permeability under a temperature condition of 60 ° C. with a moisture permeability measuring device Lyssy L80-5000 manufactured by System Illinois in accordance with JIS-K7129 A method.

[Evaluation of electrode corrosion in high temperature and high humidity test]
A liquid crystal cell for evaluation having a cell gap of 5 μm was prepared using the liquid crystal sealant produced in Examples and Comparative Examples, and the occurrence of electrode corrosion in a high temperature and high humidity test was confirmed. The test method is shown below. 0.02 g of glass fiber having a diameter of 5 μm is added to each 2 g of the liquid crystal sealant as a spacer, mixed, stirred and degassed, and filled into a 5 ml syringe. Using a dispenser (SHOTMASTER 300: manufactured by Musashi Engineering Co., Ltd.), a liquid crystal sealant previously filled in a syringe on a glass substrate with an ITO transparent electrode was applied to a rectangular seal pattern of 30 mm × 40 mm, and then liquid crystal (MLC-3007) : Merck & Co., Inc.) was dropped into the seal pattern frame. Furthermore, an in-plane spacer (NATOCO spacer KSEB-525F: manufactured by NATCO Corporation: gap width after bonding: 5 μm) is sprayed on another ITO glass substrate, heat-fixed, and then pasted in vacuum using a bonding apparatus. After bonding to the liquid crystal dripped substrate, the air was released to form a gap. In order to assume a wiring light-shielding part that is hard to irradiate the seal with ultraviolet rays, UV rays with a low dose of 500 mJ / cm2 (100 mW / cm2 for 5 seconds) are irradiated with a metal halide lamp (manufactured by Ushio Electric Co., Ltd.) and the seal pattern is halved. The seal pattern was cured by being cured and further put into an oven at 130 ° C. for 1 hour to prepare a liquid crystal cell for evaluation. The obtained liquid crystal cell for evaluation was put into a high-temperature and high-humidity condition of 60 ° C. and 90% RH for 240 hours in a state where a sine wave voltage of 10 V 100 Hz was applied with a function generator (FG-281: manufactured by Techio Technology Co., Ltd.) Thereafter, electrode corrosion was evaluated according to the following criteria by observing the seal portion for evaluation with a microscope.

○: No corrosion of the ITO electrode is observed around the seal.
Δ: Slight corrosion of the ITO electrode is observed around the seal.
X: Corrosion of the ITO electrode is observed around the seal.

[Liquid crystal contamination evaluation]
About each liquid crystal sealing agent manufactured in Examples and Comparative Examples, about 100 mg of the sealing agent was spread on the bottom of a 10 ml vial, and then liquid crystal (MLC-3007: manufactured by Merck Ltd.) was applied from above. Ten times the amount of each sealant was added. The obtained vial was heated and held at 130 ° C. for 1 hour, and then cooled to room temperature for 30 minutes. The supernatant of each liquid crystal is separated by decantation, the electrical resistance value is measured with a digital ultra-high resistance meter (R8340: manufactured by Advantest Co., Ltd.), and the following standard is the specific resistance value relative to the value of the liquid crystal without sealant Judgment was carried out.

○: 5.0 × 10 ¹² or more Δ: 5.0 × 10 ¹¹ or more and less than 5.0 × 10 ¹² ×: less than 5.0 × 10 ¹¹

  From the results shown in Table 1, Examples 1 to 3 showed results that there was no wiring corrosion and excellent low liquid crystal contamination. On the other hand, the liquid crystal sealant described in the comparative example has wiring corrosion and has a problem in the long-term reliability of the liquid crystal display cell. From this, it can be said that the present invention is a liquid crystal sealant having excellent reliability after the moisture resistance test, and the liquid crystal display cell manufactured using the same is also excellent in reliability.

  Since the liquid crystal sealant of the present invention has a very small influence on the liquid crystal display characteristics, the liquid crystal display element can be made high definition, high speed response, low voltage drive, and long life. In addition, since the adhesive strength and moisture resistance reliability are excellent, it is possible to realize the manufacture of a highly reliable liquid crystal display element.

Claims (10)

(A) a radical curable compound, (B) a photo radical polymerization initiator , (C) an inorganic filler , and polymethacrylate organic fine particles ,
The component (B) radical photopolymerization initiator has a molar extinction coefficient at 365 nm of less than 50 mL / g · cm, and the content ratio of component (B) to component (A) (content of component (B) / ( A) content of component) is 0.05 or less,
(C) The liquid crystal sealing agent for liquid crystal dropping methods whose content in the liquid crystal sealing agent total amount of an inorganic filler is 30 mass% or more. Furthermore, the liquid-crystal sealing compound for liquid crystal dropping methods of Claim 1 containing (D) thermal radical polymerization initiator. The component (D) thermal radical polymerization initiator is a thermal radical polymerization initiator that does not contain an oxygen-oxygen bond (—O—O—) and a nitrogen-nitrogen bond (—N═N—) in the molecule. Or the liquid-crystal sealing compound for liquid-crystal dripping construction methods of 2 or 2. The liquid crystal sealant for a liquid crystal dropping method according to any one of claims 1 to 3, wherein the component (A) radical curable compound is an epoxy (meth) acrylate compound. Furthermore, the liquid-crystal sealing compound for liquid crystal dropping methods as described in any one of Claims 1 thru | or 4 containing the curable compound (E) which has an epoxy group. Furthermore, the liquid-crystal sealing compound for liquid crystal dropping methods as described in any one of Claims 1 thru | or 5 containing the thermosetting agent (F). The liquid crystal sealant for a liquid crystal dropping method according to claim 7, wherein the component (F) thermosetting agent is an organic acid hydrazide. Furthermore, (G) The liquid-crystal sealing compound for liquid crystal dropping methods as described in any one of the Claims 1 thru | or 7 containing a silane coupling agent. In a liquid crystal display cell constituted by two substrates, after the liquid crystal is dropped inside the liquid crystal sealing agent weir for liquid crystal dropping method according to any one of claims 1 to 8, formed on one substrate. A method for producing a liquid crystal display cell, characterized in that the other substrate is bonded and then cured by light and / or heat. The liquid crystal display cell sealed with the hardened | cured material obtained by hardening | curing the liquid crystal sealing agent for liquid crystal dropping methods as described in any one of Claims 1 thru | or 8.