JP6202683B2 - Liquid crystal sealing agent for liquid crystal dropping method and liquid crystal display cell using the same - Google Patents

Description

  The present invention relates to a liquid crystal sealing agent used in a liquid crystal dropping method and a liquid crystal display cell using the same. More specifically, the liquid crystal sealing agent for liquid crystal dropping method is excellent in quick curing and low liquid crystal stain resistance without foaming at the time of heat curing, and also excellent in general properties as a liquid crystal sealing agent such as adhesive strength. And a liquid crystal display cell manufactured using the same.

  Conventionally, azo compounds, organic peroxides, benzoins, benzoin ethers, acetophenones, benzopinacols, etc. are known as radical generators for curing radically polymerizable compounds by radical polymerization by heating. It is used.

  Azo compounds and organic peroxides, which are considered to generate radicals most efficiently by thermal cleavage, are used as radical generators in products such as adhesives, sealants and gap forming agents, and molding materials. However, since the radical generator is accompanied by the generation of a gas such as nitrogen or carbon dioxide when the radical is generated, there is a concern that the characteristics of the product may be greatly impaired by the gas. For example, the characteristics that may be damaged include a decrease in adhesive strength, a decrease in heat resistance strength, a shape defect of a molded product, and the like. Other radical generators include benzoins, benzoin ethers, acetophenones, benzopinacols, and the like. In these, foaming at the time of heating is small, but radical generation ability is inferior, and there is a problem that desired performance (reactivity and curability) cannot be obtained.

Patent Document 1 discloses that benzopinacol is used as a thermal radical generator in a system that is cured using both ultraviolet rays and heat in order to cure a shadow portion that is not exposed to light. Patent Document 2 discloses that an iniferter type radical generator is effective in producing molded products such as contact lenses, various lenses, and dental materials, and benzopinacol is mentioned as an example. Further, Patent Document 3 mentions benzopinacol as a thermal radical generator used in a sealant for flat panel displays.
Patent Documents 1 and 3 further mention compounds in which benzopinacol is chemically modified. The compounds are further described as exhibiting the desired effect. However, benzopinacol is a tertiary alcohol, and no suitable one has been reported for obtaining a stable derivative having a poor hydroxyl group due to the steric hindrance of the phenyl group.

In addition, as one of the fields of use of the thermal radical generator, there is a liquid crystal sealing agent for a liquid crystal display cell.
With the increase in size of liquid crystal display cells, in recent years, a liquid crystal dripping method has been introduced as a method of manufacturing liquid crystal display cells, which is more mass-productive than conventional liquid crystal vacuum injection liquid crystal display cell manufacturing methods. Has been manufactured (see Patent Document 4). The liquid crystal dropping method is to apply a liquid crystal sealing agent weir on the liquid crystal substrate (main seal), and then apply the sealing agent to the outermost circumference, apply the sealing agent (dummy seal), drop the liquid crystal inside the internal seal, and then This is a manufacturing method in which the liquid crystal display cell is completed by bonding the other liquid crystal substrate facing each other in a vacuum, sealing the liquid crystal by releasing it to atmospheric pressure, and curing the seal portion by UV irradiation and heating. . As a liquid crystal sealing material used for sealing liquid crystal in this manufacturing method, not a conventional thermosetting liquid crystal sealing agent but a photothermosetting combined type liquid crystal sealing agent is generally used. The reason why the conventional thermosetting liquid crystal sealant (also called thermosetting liquid crystal sealant) is not used in the liquid crystal dropping method is that when the liquid crystal dropping method is performed with the conventional thermosetting liquid crystal sealing agent, the heat of the liquid crystal during heating This is because the viscosity is lowered by expansion and heating of the liquid crystal sealant, the seal is punctured, and the liquid crystal cannot be sealed.

  The photo-curing combined type liquid crystal sealant is used by applying a liquid crystal sealant weir to the liquid crystal substrate with a dispenser, etc., then dropping the liquid crystal inside the weir and attaching the other substrate facing in vacuum. After the alignment, the liquid crystal cell is manufactured by irradiating the seal portion with light such as ultraviolet rays and temporarily curing, and then thermally curing the liquid crystal sealant at about 120 ° C. for about 1 hour.

However, in the case of the photothermographic combination type, the liquid crystal sealant must be irradiated with light such as ultraviolet rays. However, the following problems occur with the narrowing of the frame of the liquid crystal cell in recent years.
That is, the liquid crystal seal portion is shielded from light by the wiring or the black matrix, and a portion where the liquid crystal sealant is not irradiated with light is formed, and an uncured portion is generated. There has been a problem that the uncured portion is inserted by the liquid crystal during the heat curing process or liquid crystal contamination occurs. Therefore, in designing the liquid crystal cell, there has been a restriction that the sealant must be designed so that as much light as possible is irradiated. Further, since deterioration of the liquid crystal and the alignment film due to ultraviolet irradiation becomes a problem, it is necessary to shield the liquid crystal portion with a light shielding mask during the ultraviolet irradiation process so that the ultraviolet rays do not hit the liquid crystal. Furthermore, along with the increase in the size of the liquid crystal glass substrate, the ultraviolet irradiation apparatus is increased in size, and the running cost of the ultraviolet irradiation apparatus is increasing.

From the above, in recent years, in the liquid crystal dropping method, a thermosetting liquid crystal sealing agent (thermosetting liquid crystal sealing agent for liquid crystal dropping method) that does not require ultraviolet irradiation and can produce a liquid crystal display cell only by thermosetting Realization is desired.
To date, proposals have been made for thermosetting liquid crystal sealing agents for the liquid crystal dropping method. For example, in Patent Document 5, 3 to 40 thermosetting agents are added to 100 parts by weight of a curable resin whose value obtained by dividing the number of hydrogen bonding functional groups in one molecule by molecular weight is 3.5 × 10 −4 or more. A thermosetting liquid crystal sealing agent for liquid crystal dropping method containing parts by weight has been proposed. It has been disclosed that the use of this liquid crystal sealant results in low liquid crystal contamination. However, in the liquid crystal dropping method using the thermosetting liquid crystal sealing agent, there is a problem that the liquid crystal leaks because the weir of the liquid crystal sealing agent in the middle of curing, whose viscosity has been lowered by heating, is broken (seal puncture problem) In addition, the liquid crystal sealant component whose viscosity has been reduced by heating is heated more than the NI point (temperature at which the isotropic phase transitions to the liquid crystal phase) or more, so that the liquid crystal becomes more fluid than usual. It is difficult to say that the serious problem of leaching out and contaminating the liquid crystal has been sufficiently solved.

Further, in Patent Document 6, the liquid crystal sealant to which the gelling agent is added can prevent the seal puncture and keep the seal shape by the liquid crystal dropping method only by thermosetting. However, it has not been solved about the contamination of the liquid crystal sealant to the liquid crystal at the time of heat curing, which is a problem of the thermosetting liquid crystal dropping method.
Patent Document 7 proposes a manufacturing method in which a liquid crystal sealant made of a thermosetting resin is applied, pre-baked, and thereafter liquid crystal dropping and vacuum bonding are performed. However, the specific resin composition of the liquid crystal sealant is not specified.

Patent Documents 8 and 9 propose a thermosetting liquid crystal sealing method for a liquid crystal dropping method in which a pre-baking process is performed as a B-stage (semi-cured state) process. Since this method requires a B-stage treatment for 20 minutes at 80 ° C., there is a drawback that the process time becomes long. Further, if the processing temperature is raised to, for example, 100 ° C. or more in order to shorten the B-stage processing time for 20 minutes, the described liquid crystal sealant is not preferable because the curing reaction proceeds.
Patent Document 7 proposes a liquid crystal sealing agent characterized by containing a thermal cleavage type radical generator, a thermosetting compound containing a compound having an unsaturated double bond, and a polyaddition type thermosetting agent. Yes. And, there is described production of a liquid crystal display element that is partially UV-irradiated by bonding a liquid crystal substrate at atmospheric pressure. However, there is no description about the production of a liquid crystal display element only by thermosetting without UV irradiation by vacuum decompression bonding of a liquid crystal substrate.

  Patent Document 10 discloses that a compound obtained by silylated benzopinacol is suitable for a liquid crystal sealing agent for a liquid crystal dropping method by only thermosetting. However, since it is a liquid crystal sealant for a liquid crystal dropping method that is in direct contact with liquid crystal, further fast curing and low liquid crystal contamination are required.

  As mentioned above, there is no thermosetting liquid crystal dropping sealant that solves all the problems with the thermosetting sealant in the liquid crystal dropping method, and the liquid crystal dropping method only by thermosetting has not been realized yet.

  In addition, in recent years, there has been a strong demand to increase the display area without increasing the external size of the substrate. For this reason, liquid crystal cells have been designed such as narrowing the outer periphery of the liquid crystal seal and narrowing the liquid crystal seal width. As a result, there has been a demand for a liquid crystal sealant that can be formed with a narrow seal width and has a uniform seal shape that is not easily disturbed, and a liquid crystal sealant that has high adhesive strength even if the seal width is narrow. Further, there is a demand for a liquid crystal sealant having a long pot life in which the change in application conditions of the liquid crystal sealant is small within the working time. In recent years, with the spread of liquid crystal televisions and the like, the cell gap of the liquid crystal (the gap between the two substrates filled with liquid crystal) is narrowed in order to increase the high-speed response of the liquid crystal when playing back moving images. It is coming. There has been a demand for a liquid crystal sealant that can easily narrow the cell gap when the liquid crystal substrate is vacuum-bonded.

And in response to the demand for a long life of the liquid crystal cell, deterioration of the liquid crystal seal under high humidity conditions has become a problem. There has been a demand for a liquid crystal sealant with a small deterioration of the adhesive strength of the liquid crystal seal after the high temperature and high humidity test.
As described above, the thermosetting type liquid crystal dropping method is realized, the substrate is vacuum-bonded, does not seal puncture by heating, and there is no liquid crystal contamination, and the adhesive strength after the moisture resistance test is strong. There is a need for a thermosetting liquid crystal sealant for liquid crystal dropping method that has excellent seal coatability, has a long pot life at room temperature, and is easy to narrow the cell gap.

JP-A-57-53508 Japanese Patent Laid-Open No. 11-21304 JP 2006-10870 A Japanese Patent Publication No. 8-20627 Japanese Patent No. 3955038 Japanese Patent No. 3976749 JP 2005-92043 A JP 2007-199710 A JP 2007-224117 A International Publication No. 2011-061910

  The present invention relates to a liquid crystal sealing agent used in a liquid crystal dropping method and a liquid crystal display cell using the same, and more specifically, it is excellent in quick curing and low liquid crystal contamination without foaming at the time of thermal curing, and further bonded. The present invention provides a liquid crystal sealing agent for a liquid crystal dropping method which is excellent in general characteristics as a liquid crystal sealing agent such as strength, and a liquid crystal display cell manufactured using the same.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the use of a bisimidazole skeleton radical generator can provide a thermosetting liquid crystal sealant for the liquid crystal dropping method of the previous period. The title and the present invention have been completed.
In the present specification, “(meth) acryl” means “acryl and / or methacryl”, and “(meth) acryloyl group” means “acryloyl group and / or methacryloyl group”. Further, “liquid crystal sealing agent for liquid crystal dropping method” may be simply referred to as “liquid crystal sealing agent”.

[式中、Ｒ^１〜Ｒ^６は各々独立して、水素原子、Ｃ１−Ｃ４アルキル基、Ｃ１−Ｃ４アルコキシ基又はハロゲン原子を表す。]
２）
上記式（１）において、Ｒ^１〜Ｒ^６がいずれも水素原子である上記１）に記載の液晶滴下工法用液晶シール剤、
３）
上記成分（Ａ）が平均粒子径５μｍ以下の固体粉末である上記１）又は２）に記載の液晶滴下工法用液晶シール剤、
４）
上記成分（Ｂ）が、（メタ）アクリル化エポキシ樹脂及び／又はエポキシ樹脂である上記１）乃至３）のいずれか一項に記載の液晶滴下工法用液晶シール剤、
５）
上記成分（Ｃ）が、有機酸ヒドラジド化合物である上記１）乃至４）のいずれか一項に記載の液晶滴下工法用液晶シール剤、
６）
上記成分（Ｄ）が、アルミナ及び／又はシリカである上記１）乃至５）のいずれか一項に記載の液晶滴下工法用液晶シール剤、
７）
上記成分（Ｄ）の平均粒子系が１０〜２０００ｎｍである上記１）乃至６）のいずれか一項に記載の液晶滴下工法用液晶シール剤、
８）
更に（Ｅ）水素供与体を含有する上記１）乃至７）のいずれか一項に記載の液晶滴下工法用液晶シール剤、
９）
上記成分（Ｅ）が、（Ｅ−１）アミノ基を有する化合物、又は（Ｅ−２）メルカプト基を有する化合物である上記８）に記載の液晶滴下工法用液晶シール剤、
１０）
上記成分（Ｅ）がＮ−フェニルグリシン及び／又は２−メルカプトベンゾオキサゾールである上記８）に記載の液晶滴下工法用液晶シール剤、
１１）
更に（Ｆ）シランカップリング剤を含有する上記１）乃至１０）のいずれか一項に記載の液晶滴下工法用液晶シール剤、
１２）
更に（Ｇ）有機フィラーを含有する上記１）乃至１１）のいずれか一項に記載の液晶滴下工法用液晶シール剤、
１３）
上記成分（Ｇ）が、ウレタン微粒子、アクリル微粒子、スチレン微粒子、スチレンオレフィン微粒子、及びシリコーン微粒子からなる群より選択される１又は２以上の有機フィラーである上記１２）に記載の液晶滴下工法用液晶シール剤、
１４）
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上記１）乃至１３）のいずれか一項に記載の液晶滴下工法用液晶シール剤の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、その後熱により硬化することを特徴とする液晶表示セルの製造方法、
１５）
上記１）乃至１３）のいずれか一項に記載の液晶滴下工法用液晶シール剤を硬化して得られる硬化物でシールされた液晶表示セル。 That is, the present invention relates to the following 1) to 15).
1)
(A) A liquid crystal sealant for a liquid crystal dropping method containing a radical generator represented by the following formula (1), (B) a curable compound, (C) a thermosetting agent, and (D) an inorganic filler,

[Wherein, R ^{1 to} R ⁶ each independently represents a hydrogen atom, a C1-C4 alkyl group, a C1-C4 alkoxy group or a halogen atom. ]
2)
In the above formula (1), R ^{1 to} R ⁶ are all hydrogen atoms, the liquid crystal sealing agent for liquid crystal dropping method according to 1) above,
3)
The liquid crystal sealing agent for liquid crystal dropping method according to 1) or 2), wherein the component (A) is a solid powder having an average particle size of 5 μm or less,
4)
The liquid crystal sealing agent for liquid crystal dropping method according to any one of 1) to 3), wherein the component (B) is a (meth) acrylated epoxy resin and / or an epoxy resin,
5)
The liquid crystal sealing agent for a liquid crystal dropping method according to any one of 1) to 4) above, wherein the component (C) is an organic acid hydrazide compound,
6)
The liquid crystal sealing agent for a liquid crystal dropping method according to any one of 1) to 5), wherein the component (D) is alumina and / or silica,
7)
The liquid crystal sealing agent for a liquid crystal dropping method according to any one of 1) to 6) above, wherein the average particle system of the component (D) is 10 to 2000 nm,
8)
Furthermore, (E) Liquid crystal sealing agent for liquid crystal dropping method as described in any one of 1) to 7) above containing a hydrogen donor,
9)
The liquid crystal sealing agent for liquid crystal dropping method according to 8), wherein the component (E) is (E-1) a compound having an amino group or (E-2) a compound having a mercapto group,
10)
The liquid crystal sealing agent for liquid crystal dropping method according to 8), wherein the component (E) is N-phenylglycine and / or 2-mercaptobenzoxazole,
11)
Furthermore, (F) Liquid crystal sealing agent for liquid crystal dropping methods as described in any one of 1) to 10) above containing a silane coupling agent,
12)
(G) Liquid crystal sealing agent for liquid crystal dropping method according to any one of 1) to 11) above, which contains an organic filler,
13)
The liquid crystal for liquid crystal dropping method according to 12), wherein the component (G) is one or more organic fillers selected from the group consisting of urethane fine particles, acrylic fine particles, styrene fine particles, styrene olefin fine particles, and silicone fine particles. Sealant,
14)
In a liquid crystal display cell composed of 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 13) formed on one substrate. Thereafter, the other substrate is bonded, and then cured by heat, a method for producing a liquid crystal display cell,
15)
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 13).

The bisimidazole represented by the general formula (1) used in the present invention is useful as a thermal radical generator, has no foaming at the time of heating, and has a high molecular weight of the decomposed product even when decomposed, so that the contamination of the liquid crystal Is low. Therefore, it can be used as a thermal radical generator that has no fear of deterioration of physical properties due to foaming, for a wide variety of uses such as the production of adhesives, sealants, gap forming agents, molding materials, etc. Products with excellent cured properties, adhesive strength, shape stability, etc. can be obtained. In particular, it is excellent as a thermal radical generator for a thermosetting liquid crystal sealing agent used in a liquid crystal dropping method.
The thermosetting liquid crystal sealing agent using the bisimidazole represented by the general formula (1) used in the present invention as a thermal radical generator is a thermosetting for liquid crystal dropping method that does not require ultraviolet irradiation to the liquid crystal sealing portion. The liquid crystal sealant (hereinafter also referred to as the liquid crystal sealant of the present invention) is optimal.

  The liquid crystal sealant of the present invention contains a radical generator represented by the above formula (1) as the component (A).

In said formula (1), R < ¹ > -R < ⁶ > respectively independently represents a hydrogen atom, a C1-C4 alkyl group, a C1-C4 alkoxy group, or a halogen atom. Of these, preferred is a hydrogen atom.

  The C1-C4 alkyl group in the formula (1) represents a linear or branched alkyl group having 1 to 4 carbon atoms. A branched chain such as an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group; Of these, preferred are straight-chain ones such as a methyl group and an ethyl group, and more preferred is a methyl group.

  The C1-C4 alkoxy group in the above formula (1) represents a linear or branched alkoxy group having 1 to 4 carbon atoms, for example, a linear chain such as a methoxy group, an ethoxy group, an n-propoxy group, or an n-butoxy group. A branched chain such as an isopropoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group; Of these, preferred are straight-chain ones such as a methoxy group and an ethoxy group, and more preferred is a methyl group.

  Examples of the halogen atom in the above formula (1) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. A fluorine atom or a chlorine atom is preferable, and a chlorine atom is particularly preferable.

Examples of the thermal radical generator represented by the above formula (1) used in the present invention include 2,4,5,2 ′, 4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2 , 2′-bis (o-tolyl) -4,5,4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2,2′-bis (m-tolyl) -4,5,4 ′ , 5′-tetraphenyl-4,4′-biimidazole, 2,2′-bis (p-tolyl) -4,5,4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2, 2′-bis (o-ethylphenyl) -4,5,4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2,2′-bis (m-ethylphenyl) -4,5,4 ', 5'-tetraphenyl-4,4'-biimidazole, 2,2'-bis (p-ethylphenyl) -4,5,4', 5'-tetraphenyl-4,4 ' -Biimidazole, 2,2'-bis (on-propylphenyl) -4,5,4 ', 5'-tetraphenyl-4,4'-biimidazole, 2,2'-bis (mn) -Propylphenyl) -4,5,4 ', 5'-tetraphenyl-4,4'-biimidazole, 2,2'-bis (pn-propylphenyl) -4,5,4', 5 '-Tetraphenyl-4,4'-biimidazole,2,2'-bis (o-propylphenyl) -4,5,4 ', 5'-tetraphenyl-4,4'-biimidazole, 2, 2'-bis (m-i-propylphenyl) -4,5,4 ', 5'-tetraphenyl-4,4'-biimidazole, 2,2'-bis (pi-propylphenyl) -4 , 5,4 ′, 5′-Tetraphenyl-4,4′-biimidazole, 2,2′-bis (ot-propylphenyl) -4 , 5,4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2,2′-bis (mt-propylphenyl) -4,5,4 ′, 5′-tetraphenyl-4, 4′-biimidazole, 2,2′-bis (pt-propylphenyl) -4,5,4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2,2′-bis (o -Fluorophenyl) -4,5,4 ', 5'-tetraphenyl-4,4'-biimidazole, 2,2'-bis (m-fluorophenyl) -4,5,4', 5'-tetra Phenyl-4,4′-biimidazole, 2,2′-bis (p-fluorophenyl) -4,5,4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2,2′-bis (O-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2,2′-bis (m-chloro) Phenyl) -4,5,4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2,2′-bis (p-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-4 , 4′-biimidazole, 2,2′-bis (o-bromophenyl) -4,5,4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2,2′-bis (m- Bromophenyl) -4,5,4 ′, 5′-tetraphenyl-4,4′-biimidazole, 2,2′-bis (p-bromophenyl) -4,5,4 ′, 5′-tetraphenyl -4,4'-biimidazole. 2,4,5,2 ′, 4 ′, 5′-tetraphenyl-4,4′-biimidazole is preferred.
These are commercially available from Nikko Chemtech Co., Ltd., etc., but using the corresponding benzyl and benzaldehyde, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN VOL. 43 429-438 (1970).

  The component (A) is preferably dispersed uniformly with a fine particle size. The average particle diameter is preferably 5 μm or less, and more preferably 3 μm or less, because if the average particle size is too large, it becomes a cause of defects such as poor gap formation when the upper and lower glass substrates are bonded together during the production of a narrow gap liquid crystal cell. In addition, the particle size of (a) can be made infinitely fine, but the lower limit is usually about 0.1 μm as the average particle size.

  The content of the component (A) in the liquid crystal sealant of the present invention is usually 0.1 to 10% by mass, preferably 0.3 to 7% by mass, and more preferably 0.5%, based on the total amount of the liquid crystal sealant. ˜5 mass%. When the content is less than 0.1% by mass, the curability is deteriorated and seal puncture occurs, and when the content is more than 10% by mass, the liquid crystal contamination may be increased.

The liquid crystal sealing agent of the present invention contains a curable compound as the component (B).
The component (B) is not particularly limited as long as it undergoes a polymerization reaction by light or heat, and examples thereof include a curable compound having a (meth) acryloyl group and a curable compound having an epoxy 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 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, and other difunctional phenolic diglycidyl esters such as catechol and resorcinol Ether compound, bi-functional alcohol diglycidyl ethers of, and their halides, and the like hydrogenated product. Among these, from the viewpoint of liquid crystal contamination, an epoxy resin having a resorcin skeleton is preferable, 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.
Examples of the curable compound having an epoxy group include an epoxy resin. Although it does not specifically limit as this epoxy resin, The epoxy resin more than bifunctional is preferable, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak 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 resin, phenol novolac type epoxy resin with triphenolmethane skeleton, diglycidyl etherified product of bifunctional phenols, diglycidyl of bifunctional alcohols Ether compound, and their halides, and the like hydrogenated product. Among these, bisphenol type epoxy resin and novolac type epoxy resin are preferable from the viewpoint of liquid crystal contamination.
The curable compound having a (meth) acryloyl group and the curable compound having an epoxy group can be used in combination of two or more, and a (meth) acrylated epoxy resin and an epoxy resin can be used in combination. This is one of the particularly preferred embodiments of the invention.

  The content of the component (B) in the liquid crystal sealant of the present invention is usually 30 to 75% by mass, preferably 40 to 65% by mass. In particular, when an epoxy resin and a (meth) acrylated epoxy resin are used in combination In the above, the content of the epoxy resin in the component (B) is usually 3 to 30% by mass, preferably 5 to 20% by mass, and more preferably 8 to 15% by mass.

The liquid crystal sealing agent of the present invention contains a thermosetting agent as the component (C).
The component (C) means a thermosetting agent that does not generate radicals by heating, unlike the above-described component (A) radical generator. 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 (2-hydrazinocarbonylethyl) isocyanurate, tris ( 2-hydrazinocarbonylethyl) isocyanurate and tris (3-hydrazinocarbonylpropyl) isocyanurate, particularly preferably malonic acid dihydrazide.
The content of the component (C) thermosetting agent is preferably 0.1 to 10% by mass and more preferably 1 to 5% by mass in the total amount of the liquid crystal sealant.

The liquid crystal sealing agent of the present invention contains an inorganic filler as component (D).
As the component (D), fused silica, crystalline silica, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, magnesium oxide, zirconium oxide, hydroxide Aluminum, 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, aluminum silicate, more preferably fused silica, crystalline silica, alumina, tar It is. These inorganic fillers may be used in combination of two or more.
The average particle size of the component (D) is suitably 2000 nm or less, since it becomes a cause of defects such as failure to form a gap when the upper and lower glass substrates are bonded together when a narrow gap liquid crystal cell is produced. 1000 nm or less. Moreover, a preferable minimum is about 10 nm, More preferably, it is about 20 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).
In the liquid crystal sealing agent of the present invention, when an inorganic filler is used, it is usually 5 to 50% by mass, preferably 5 to 40% by mass, in the total amount of the liquid crystal sealing agent. When the content of the inorganic filler is lower than 5% by mass, 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. Moreover, when there is more content of an inorganic filler than 50 mass%, since there is too much filler content, it may become difficult to collapse and it will become impossible to form the gap of a liquid crystal cell.

  The liquid crystal sealant of the present invention may contain (E) a hydrogen donor for further improving the curability. The component (E) hydrogen donor is not particularly limited as long as it is a compound that abstracts hydrogen and generates a radical. For example, a compound having a hydroxy group in the molecule such as a phenol compound or an amino acid in the molecule. And a compound having a mercaptooxy group. Of these, compounds having an amino group or a mercapto group in the molecule are preferred. Specific examples of the compound having an amino group include N-phenylglycine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, and the like. As a compound having a mercapto group, 2-mercaptobenzoxazole, glutathione, dodecanethiol, mercaptobenzothiazole, mercaptobenzimidazole, 5-chloro-2-mercaptobenzothiazole, 2-mercapto-5-methoxybenzothiazole, 5-methyl- 1,3,4-thiadiazole-2-thiol, 5-mercapto-1-methyltetrazole, 3-mercapto-4-methyl-4H-1,2,4-triazole, 2-mercapto-1-methylimidazole, 2- Mercaptothiazoline, octanethiol, hexanedithiol, decandidiol, 1,4-dimethylmercaptobenzene, 1,4-butanediol bis (3-mercaptopropionate), 1,4-butanediol bis (mercaptoacetate) G), ethylene glycol bis (3-mercaptopropionate), ethylene glycol bis (mercaptoacetate), trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris (mercaptoacetate), pentaerythritol tetrakis (3 -Mercaptopropionate), pentaerythritol tetrakis (mercaptoacetate), and the like. Among these, N-phenylglycine and / or 2-mercaptobenzoxazole are more preferable.

  The component (E) is preferably dispersed uniformly with a fine particle size. The average particle size is preferably 4 μm or less, and more preferably 3 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 during the production of a narrow gap liquid crystal cell. The lower limit as the average particle size is usually about 0.1 μm.

  The content of the component (E) in the liquid crystal sealant of the present invention is preferably 0.5 to 15% by mass, more preferably 1 to 8% by mass.

The liquid crystal sealant of the present invention can be improved in adhesion strength and moisture resistance by adding a silane coupling agent as component (F).
Component (F) includes 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. The content of the silane coupling agent (E) in the liquid crystal sealant is preferably 0.05 to 3% by mass in the total amount of the liquid crystal sealant of the present invention.

In the liquid crystal sealing agent of the present invention, an organic filler may be added as the component (G).
Examples of the component (G) include urethane fine particles, acrylic fine particles, styrene fine particles, styrene olefin fine particles, and silicone fine particles. The silicone fine particles are preferably KMP-594, KMP-597, KMP-598 (manufactured by Shin-Etsu Chemical Co., Ltd.), Trefil ^RTM E-5500, 9701, EP-2001 (manufactured by Toray Dow Corning), and the urethane fine particles are JB-800T, HB-800BK (Negami Kogyo Co., Ltd.), and styrene fine particles are preferably Lavalon ^RTM T320C, T331C, SJ4400, SJ5400, SJ6400, SJ4300C, SJ5300C and SJ6300C (manufactured by Mitsubishi Chemical Corporation). Septon ^RTM SEPS 2004 and SEPS 2063 are preferred.
These organic fillers may be used alone or in combination of two or more. Moreover, it is good also as a core-shell structure using 2 or more types. Of these, acrylic fine particles and silicone fine particles are preferable.
When the above acrylic fine particles are used, it is preferable that the acrylic rubber has a core-shell structure composed of two kinds of acrylic rubbers, and particularly preferably a core layer is n-butyl acrylate and a shell layer is methyl methacrylate. This is sold by Aika Industries as Zefiac ^RTM F-351.
Examples of the silicone fine particles include crosslinked organopolysiloxane powders and linear dimethylpolysiloxane crosslinked powders. Examples of the composite silicone rubber include those obtained by coating the surface of the silicone rubber with a silicone resin (for example, polyorganosilsesquioxane resin). Among these fine particles, a silicone rubber of a linear dimethylpolysiloxane crosslinked powder or a composite silicone rubber fine particle of a silicone resin-coated linear dimethylpolysiloxane crosslinked powder is particularly preferable. These may be used alone or in combination of two or more. Preferably, the rubber powder has a spherical shape with little viscosity increase after addition. In the liquid crystal sealing agent of the present invention, when an organic filler is used, it is usually 5 to 50% by mass, preferably 5 to 40% by mass, in the total amount of the liquid crystal sealing agent.

  If necessary, the liquid crystal sealing agent for the liquid crystal dropping method of the present invention further includes a photopolymerization initiator, a radical polymerization inhibitor, a curing accelerator such as an organic acid or an imidazole compound, an organic solvent, a pigment, a leveling agent, an antifoaming agent. Additives such as agents can be blended.

The photopolymerization initiator is not particularly limited as long as it is a compound that generates radicals or acids upon irradiation with ultraviolet rays or visible light, and initiates a chain polymerization reaction. 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- Examples thereof include trimethylbenzoyldiphenylphosphine oxide, camphorquinone, 9-fluorenone, diphenyldisulfide and the like. Specifically, IRGACURE ^RTM 651, 184, 2959, 127, 907, 396, 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.
When the photopolymerization initiator is used, the content of the liquid crystal sealant in the total amount is usually 0.001 to 3% by mass, preferably 0.002 to 2% by mass.

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 radical polymerization inhibitor is dissolved in the component (C) (meth) acrylated epoxy resin and / or component (C) (meth) acrylated epoxy resin and / or component (E) epoxy resin. Although there is a method, in order to obtain a more effective effect, it is preferable to add to and dissolve the component (C) (meth) acrylated epoxy resin and / or the component (E) curable resin having an epoxy group. .
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.

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.

  An example of a method for obtaining the liquid crystal sealant of the present invention is the following method. First, in component (B) (when multiple components are used, heat and mix and cool to room temperature), component (A), component (C), component (D) and, if necessary, component (E), component (F), component (G), antifoaming agent, leveling agent, solvent, etc. are added, mixed uniformly by a known mixing device such as a three roll, sand mill, ball mill, etc., and filtered through a metal mesh. Thus, the liquid crystal sealant of the present invention is produced.

In the liquid crystal display cell of the present invention, a pair of substrates on which predetermined electrodes are formed are arranged opposite to each other at a predetermined interval, the periphery is sealed with the liquid crystal sealing agent for thermosetting liquid crystal dropping method of the present invention, and the liquid crystal is in the gap It is enclosed. The kind of liquid crystal to be sealed is not particularly limited.
Here, the substrate is made of glass, quartz, plastic, silicon or the like. In the method for producing a liquid crystal display cell by the thermosetting liquid crystal dropping method, first, a spacer (gap control material) such as glass fiber is added to and mixed with the liquid crystal sealing agent of the present invention. Examples of the spacer include glass fiber, silica beads, polymer beads and the like. Although the diameter varies depending on the purpose, it is usually 2 to 8 μm, preferably 3 to 6 μm, and the amount used is usually 0.1 to 4 parts by weight, preferably 0.5 to 4 parts per 100 parts by weight of the liquid crystal sealant. The amount is about 2 parts by weight, more preferably about 0.9 to 1.5 parts by weight.

After applying a liquid crystal sealant containing a spacer to one side of the substrate with a dispenser or the like to form a weir (main seal), in order to keep the liquid crystal sealing substrate in a vacuum, the sealant is further applied to the outermost circumference. Apply (dummy seal). Thereafter, the liquid crystal is dropped inside the weir of the internal seal, and the other glass substrate is overlaid in a vacuum, and then opened to the atmospheric pressure to release the gap. The dummy sealant for holding the liquid crystal sealing substrate in a vacuum does not come into contact with the liquid crystal and is cut off after completion of the liquid crystal cell. Even if the same liquid crystal sealant is used, another UV curable type is used. A sealant, a visible light curable sealant, or a thermosetting sealant may be used. After the vacuum gap is formed, when UV curable sealant or visible light curable sealant, which is a light curable sealant, is used for the dummy seal, UV or visible light is applied to the dummy seal part by an ultraviolet irradiator or visible light irradiator. Irradiate to cure the dummy seal. If no photo-curing sealant is used for the dummy seal, the light irradiation step is omitted. The liquid crystal display cell of the present invention can be obtained by heating the gap-formed substrate 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 Hereinafter, although a synthesis example and an Example demonstrate this invention still 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 2,4,5,2 ′, 4 ′, 5′-tetraphenyl-4,4′-biimidazole]
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN VOL. 43 429-438 (1970).
2.5 g of 2,4,5-triphenylimidazole was dissolved in 250 mL of 2N potassium hydroxide ethanol solution, and 2% aqueous hexacyanoiron (III) potassium solution was added dropwise to the solution over 1.5 hours at 5 ° C. As a result, a reaction solution was obtained. The reaction solution was filtered, washed with water and dried to obtain 2.5 g of the desired product.
[Synthesis Example 2]
[Synthesis of resorcin diglycidyl ether]
Resorcin 5500g, epichlorohydrin 37000g and tetramethylammonium chloride 500g were added and dissolved under stirring, and the temperature was raised to 70 ° C. Next, 4000 g of flaky sodium hydroxide was added in portions over 100 minutes, and then post-reaction was 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 under reduced pressure at 130 ° C. 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 a 30 wt% aqueous sodium hydroxide solution was added and the reaction was carried out for 1 hour, followed by washing with water 5550 g three times. Methyl isobutyl ketone was distilled off at 180 ° C. under reduced pressure to obtain 10550 g of a resorcin diglycidylated product. Obtained. The epoxy equivalent of the obtained epoxy resin was 129 g / eq.
[Synthesis Example 3]
[Synthesis of total acrylate of resorcin diglycidyl ether]
Resorcin diglycidyl ether 181.2 g (synthesized in Synthesis Example 2 above) was dissolved in 266.8 g of toluene, 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 with 100% equivalent of epoxy group was added and the temperature was further raised to 80 ° C., 0.6 g of trimethylammonium chloride as a reaction catalyst was added thereto, and the mixture was stirred at 98 ° C. for about 30 hours, A reaction solution was obtained. This reaction solution was washed with water, and toluene was distilled off to obtain 293 g of the desired resorcin diglycidyl ether epoxy acrylate. The reactive group equivalent of the obtained epoxy acrylate is 183 in theory.

[Examples 1-3, Comparative Examples 1-2]
A liquid crystal sealant was produced using the components (A) and (B) in the amounts shown in Table 1. The manufacturing method is as follows.
First, as component (B), an epoxy acrylate and an epoxy resin are heated and mixed, cooled to room temperature, then component (A) radical generator, component (C) thermosetting agent, component (D) inorganic filler, component (E ) Add hydrogen donor, component (F) silane or pulling agent, (G) organic filler, knead with 3 rolls and filter with metal mesh (635 mesh) to produce liquid crystal sealant of the present invention did.

  The liquid crystal sealing agents prepared in Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated as follows. The results are summarized in Table 2.

[Creation of liquid crystal cell for evaluation]
As a spacer, 1 g of 5 μm glass fiber is added to each 100 g of the liquid crystal sealants of Examples 1 to 3 and Comparative Examples 1 and 2, mixed and defoamed, and filled into a syringe. An alignment film solution (PIA-5540-05A; manufactured by Chisso Corporation) was applied to a glass substrate with an ITO transparent electrode, fired, and rubbed. Using this dispenser (SHOTMASTER 300: manufactured by Musashi Engineering Co., Ltd.), the liquid crystal sealants of Examples and Comparative Examples previously filled in a syringe on this substrate were applied with a seal pattern and a dummy seal pattern, and then liquid crystal (JC-5015LA Small droplets manufactured by Chisso Corporation) were dropped into the frame of the seal pattern. Further, an in-plane spacer (NATOCO SPACER KSEB-525F; manufactured by NATCO; gap width of 5 μm after bonding) is sprayed on another glass substrate that has been subjected to rubbing treatment, heat-adhered, and in a vacuum using a vacuum bonding apparatus. Then, the substrate was bonded to the liquid crystal dripped substrate. Then, after opening to the atmosphere and forming a gap, it was put into an oven at 120 ° C. and cured by heating for 1 hour to prepare a liquid crystal test cell for evaluation.

Table 2 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. Further, Table 2 shows the results of measuring the gap of the prepared liquid crystal cell using a liquid crystal characteristic evaluation apparatus (OMS-NK3: manufactured by Chuo Seiki Co., Ltd.). The evaluation of the seal shape, liquid crystal alignment disorder, and the gap of the liquid crystal cell was made into the following four stages.
The seal shape is an evaluation related to the coating workability, and the evaluation of the liquid crystal alignment is an evaluation related to the liquid crystal contamination. The liquid crystal cell gap can also be confirmed for insertion resistance.

[Evaluation of seal shape]
○: There is no disturbance in the linearity of the seal.
[Delta]: Deformation of the seal is recognized, but there is no problem in sealing the liquid crystal.
X: A level at which liquid crystal is inserted into the seal and a problem may occur in sealing the liquid crystal.
XX: The seal is broken and a cell cannot be formed.

[Liquid crystal cell gap evaluation]
A: The cell gap is uniformly 5 μm.
Δ: There is a place where a gap of about 5.5 μm is not formed in the cell.
X: There is a place where a gap of 6 μm or more does not appear in the cell.
XX: The seal is broken and a cell cannot be formed.

[Evaluation of liquid crystal alignment]
○: There is no alignment disorder in the vicinity of the seal.
Δ: There is a slight disorder in the alignment of the liquid crystal in the vicinity of the seal.
X: There is disorder in alignment of liquid crystal in the vicinity of the seal.
XX: The seal is broken and a cell cannot be formed.

表２に示されるように、実施例１〜３の液晶シール剤は差込耐性が十分でありながら、塗布作業性に優れ、また液晶汚染性も低いシール剤であることが確認された。

As shown in Table 2, it was confirmed that the liquid crystal sealants of Examples 1 to 3 were sealants with excellent insertion workability and low liquid crystal contamination while having sufficient insertion resistance.

  The liquid crystal sealing agent for the liquid crystal dropping method of the present invention has high liquid crystal insertion resistance and low liquid crystal contamination due to the excellent performance of the radical generator. In addition, the coating workability such as dispensing and screen printing is excellent. Furthermore, since it is a liquid crystal sealant for a liquid crystal dropping method that is excellent in general properties as a liquid crystal sealant such as adhesive strength, a liquid crystal display cell having excellent long-term reliability can be easily manufactured. .

Claims (15)

(A) A liquid crystal sealant for a liquid crystal dropping method comprising a radical generator represented by the following formula (1), (B) a curable compound, (C) a thermosetting agent, and (D) an inorganic filler.

[Wherein, R ^{1 to} R ⁶ each independently represents a hydrogen atom, a C1-C4 alkyl group, a C1-C4 alkoxy group or a halogen atom. ] 2. The liquid crystal sealant for a liquid crystal dropping method according to claim 1, wherein in the formula (1), R ^{1 to} R ⁶ are all hydrogen atoms. The liquid crystal sealing agent for a liquid crystal dropping method according to claim 1 or 2, wherein the component (A) is a solid powder having an average particle size of 5 µm or less. The liquid crystal sealing agent for a liquid crystal dropping method according to any one of claims 1 to 3, wherein the component (B) is a (meth) acrylated epoxy resin and / or an epoxy resin. The said component (C) is an organic acid hydrazide compound, The liquid-crystal sealing compound for liquid crystal dropping methods as described in any one of Claims 1 thru | or 4. The liquid crystal sealant for a liquid crystal dropping method according to any one of claims 1 to 5, wherein the component (D) is alumina and / or silica. The average particle system of the said component (D) is 10-2000 nm, The liquid-crystal sealing compound for liquid crystal dropping methods as described in any one of Claims 1 thru | or 6. Furthermore, the liquid-crystal sealing compound for liquid crystal dropping methods as described in any one of Claims 1 thru | or 7 containing (E) hydrogen donor. The liquid crystal sealing agent for a liquid crystal dropping method according to claim 8, wherein the component (E) is a compound having an (E-1) amino group or a compound having an (E-2) mercapto group. The liquid crystal sealing agent for a liquid crystal dropping method according to claim 8, wherein the component (E) is N-phenylglycine and / or 2-mercaptobenzoxazole. The liquid crystal sealing agent for a liquid crystal dropping method according to any one of claims 1 to 10, further comprising (F) a silane coupling agent. Furthermore, (G) The liquid-crystal sealing compound for liquid crystal dropping methods as described in any one of Claims 1 thru | or 11 containing an organic filler. The liquid crystal for a liquid crystal dropping method according to claim 12, wherein the component (G) is one or more organic fillers selected from the group consisting of urethane fine particles, acrylic fine particles, styrene fine particles, styrene olefin fine particles, and silicone fine particles. Sealing 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 13 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 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 13.