Liquid crystal seal agent for liquid crystal dropping method and liquid crystal display panel using the same

Abstract

To provide a liquid crystal seal agent for a liquid crystal dropping method which is excellent in adhesiveness and moisture permeation property, and a liquid crystal display panel sealed with a cured product of the same, wherein the liquid crystal seal agent for the liquid crystal dropping method has excellent adhesiveness to stresses in both directions of a shear direction and a peeling direction.SOLUTION: A liquid crystal seal agent for a liquid crystal dropping method contains a component (A): a filler having an average particle diameter of 0.4 μm or less, a component (B): a curable compound, a component (C): a photo-radical polymerization initiator, and a component (D): a thermosetting agent, wherein the content of the component (A) is 7 pts.wt. or more and 25 pts.wt. or less with respect to 100 pts.wt. of the component (B), (B-1) a compound having a (meth)acrylic group and (B-2) a compound having a thiol group are contained as the components (B), and an elastic modulus of a cured product at 25°C measured by a universal testing machine is 2,000 MPa or more and less than 4,500 MPa.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a liquid crystal sealing agent for a liquid crystal droplet discharge method and a liquid crystal display cell sealed with a cured product thereof.

Background Art

[0002] In recent years, as a method for manufacturing a liquid crystal display element, from the viewpoints of shortening tact time and optimizing the amount of liquid crystal used, a droplet discharge method using a photothermal dual-curing type sealing agent containing a curable resin, a photopolymerization initiator, and a thermosetting agent, as disclosed in Patent Document 1 and Patent Document 2, is used.

[0003] In the droplet discharge method, first, a rectangular seal pattern is formed by dispensing on one of two transparent substrates with electrodes. Next, minute droplets of liquid crystal are dropped onto the entire surface within the frame of the transparent substrate while the sealing agent is in an uncured state, and immediately the other transparent substrate is superposed, and light such as ultraviolet rays is irradiated on the seal portion to perform temporary curing. Then, heating is performed for final curing to produce a liquid crystal display element. By performing the bonding of the substrates under reduced pressure, a liquid crystal display element can be manufactured with extremely high efficiency, and currently this droplet discharge method has become the mainstream of the manufacturing method of liquid crystal display elements.

[0004] With the spread of tablet terminals and mobile terminals, the liquid crystal display element is increasingly required to have durability against impact tests, drop tests, etc., and the adhesiveness to the substrate is increasingly required. In addition, with the narrowing of the bezel of the panel, moisture resistance reliability in driving under a high temperature and high humidity environment, etc. is required, and the sealing agent is further required to have the performance of preventing the intrusion of water from the outside. In order to improve the impact resistance and moisture resistance reliability of the liquid crystal display element, it is necessary to improve the adhesiveness between the sealing agent and the substrate, etc., and to lower the moisture permeability of the cured product of the sealing agent. However, it has been difficult to produce a sealing agent that is excellent in both adhesiveness and moisture permeability prevention.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-133794 [Patent Document 2] Japanese Patent Application Laid-Open No. 5-295087 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] An object of the present invention is to provide a liquid crystal sealing agent for a liquid crystal dropping method, which is excellent in adhesiveness and moisture permeability preventing property, and a liquid crystal display panel sealed with a cured product thereof. In particular, the liquid crystal sealing agent for a liquid crystal dropping method of the present invention has excellent adhesiveness to stresses in both the shear direction and the peeling direction. [Means for Solving the Problems]

[0007] That is, the present invention relates to the following [1] to [7]. In the present application, “(numerical value 1) to (numerical value 2)” indicates that the upper and lower limit values are included. Further, “(meth) acrylate” means “acrylate” and / or “methacrylate”. [1] A liquid crystal sealing agent for a liquid crystal dropping method, which contains a filler (A) having an average particle diameter of 0.4 μm or less, a curable compound (B), a photo radical polymerization initiator (C), and a thermosetting agent (D), the content of the component (A) is 7 parts by weight or more and 25 parts by weight or less with respect to 100 parts by weight of the component (B), as the component (B), it contains a compound (B-1) having a (meth) acrylic group and a compound (B-2) having a thiol group, A liquid crystal sealing agent for a liquid crystal dropping method, wherein the elastic modulus of the cured product at 25 ° C. measured by a universal testing machine is 2000 MPa or more and less than 4500 MPa. [2] The liquid crystal sealing agent for a liquid crystal dropping method according to the above [1], wherein the moisture permeability of the cured product measured under the conditions of 60 ° C. and 90% is 50 g / m 2 · 24 h or less. [3] The liquid crystal sealing agent for the liquid crystal dropping method according to the preceding item [1] or [2], which contains partial epoxy (meth)acrylate as the component (B-1). [4] The liquid crystal sealing agent for the liquid crystal dropping method according to any one of the preceding items [1] to [3], which contains urethane (meth)acrylate as the component (B-1). [5] Furthermore, the liquid crystal sealing agent for the liquid crystal dropping method according to any one of the preceding items [1] to [4], which contains a component (E) thermal radical polymerization initiator. [6] The liquid crystal sealing agent for the liquid crystal dropping method according to the preceding item [5], wherein the component (E) 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. [7] A liquid crystal display panel sealed with the liquid crystal sealing agent for the liquid crystal dropping method according to any one of the preceding items [1] to [6].

Effects of the Invention

[0008] The present invention can provide a liquid crystal sealing agent for the liquid crystal dropping method, which is excellent in adhesiveness and moisture permeability prevention, and a liquid crystal display panel sealed with a cured product thereof.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0010] The sealant for the liquid crystal dropping method of the present invention (hereinafter, also simply referred to as "liquid crystal sealant") contains a filler (A) with an average particle diameter of 0.4 μm or less, a curable compound (B), a photo radical polymerization initiator (C), and a thermosetting agent (D). The content of the component (A) is 7 parts by weight or more and 25 parts by weight or less with respect to 100 parts by weight of the component (B). As the component (B), it contains a compound (B-1) having a (meth)acrylic group and a compound (B-2) having a thiol group, and the elastic modulus of the cured product at 25°C measured by a universal testing machine is 2000 MPa or more and less than 4500 MPa.

[0011] In the present invention, the elastic modulus is measured by a universal testing machine (Autograph AG-Xplus500N manufactured by Shimadzu Corporation) at room temperature (25°C) for a cured product with a thickness of 100 μm cured under the conditions of 120°C for 70 minutes after irradiation with ultraviolet rays at 3000 mJ / cm 2 (measurement wavelength: 365 nm). The elastic modulus of the liquid crystal sealant of the present invention is 2000 MPa or more and less than 4500 MPa, and more preferably 2500 MPa or more and 4000 MPa or less.

[0012] In the present invention, the moisture permeability is measured using a moisture permeability measuring machine (L80-5000 manufactured by Lyssy) for a cured product with a thickness of 300 μm cured under the conditions of 120°C for 70 minutes after irradiation with ultraviolet rays at 3000 mJ / cm 2 (measurement wavelength: 365 nm), but it may also be measured by leaving the cured product standing for 24 hours under the conditions of 60°C and 90%. The moisture permeability of the liquid crystal sealant of the present invention is preferably 50 g / m 2 ·24 h or less, and more preferably 40 g / m 2 ·24 h or less.

[0013] The liquid crystal sealing agent for the liquid crystal droplet application method of the present invention has excellent adhesiveness to stresses in both the shear direction and the peeling direction. Specifically, in the measurement method described later, the shear adhesion strength is preferably 15 MPa or more. The upper limit is not particularly limited, but is preferably 30 MPa or less. The peeling adhesion strength is preferably 1.5 kgf or more. The upper limit is not particularly limited, but is preferably 3.0 kgf or less.

[0014] [(A) Filler with an average particle diameter of 0.4 μm or less] Component (A) Filler with an average particle diameter of 0.4 μm or less (hereinafter, also simply referred to as component (A)) is a filler with an average particle diameter of 0.4 μm or less, and examples include organic fillers and inorganic fillers.

[0015] In the present invention, the average particle diameter can be measured by a laser diffraction / scattering particle size distribution analyzer (dry type) (manufactured by Seishin Enterprise Co., Ltd.; LMS-30). Also, for commercially available products, not limited to the above method, values specified in each company's catalog may be used.

[0016] The lower limit of the average particle diameter is not particularly limited, but is preferably 0.001 μm or more, more preferably 0.01 μm or more, and particularly preferably 0.1 μm or more. Also, the upper limit is preferably 0.4 μm or less, more preferably 0.3 μm or less. This is because being 0.4 μm or less provides excellent adhesion in the shear direction of the liquid crystal sealing agent, and being 0.001 μm or more provides excellent dispersibility and dispensability.

[0017] Also, the shape of the particles may be spherical, plate-like, or other shapes, but considering the gap property, a spherical shape is preferred.

[0018] The content of component (A) is preferably 7 to 25 parts by weight, more preferably 12 to 20 parts by weight, based on 100 parts by weight of the curable compound of component (B) described below. When it is 7 parts by weight or more, the adhesive strength in the peeling direction increases, and when it is 25 parts by weight or less, the thixotropy ratio decreases and the wettability to the substrate increases.

[0019] [Organic filler] Examples of the organic filler include urethane fine particles, acrylic fine particles, styrene fine particles, styrene olefin fine particles, and silicone fine particles. Examples of the silicone fine particles include KMP-594, KMP-597, KMP-598 (manufactured by Shin-Etsu Chemical Co., Ltd.), and Trefl RTM E-5500, 9701, EP-2001 (manufactured by Toray Dow Corning Co., Ltd.) are preferred. Examples of the urethane fine particles include JB-800T, HB-800BK (Negami Kogyo Co., Ltd.), and examples of the styrene fine particles include Lavaron RTM T320C, T331C, SJ4400, SJ5400, SJ6400, SJ4300C, SJ5300C, SJ6300C (manufactured by Mitsubishi Chemical Corporation) are preferred. Examples of the styrene olefin fine particles include Septon RTM SEPS2004 and SEPS2063 are preferred. These organic fillers may be used alone or in combination of two or more. Also, a core-shell structure may be formed using two or more of them. Among these, acrylic fine particles and silicone fine particles are preferred. When using the above acrylic fine particles, it is preferably an acrylic rubber having a core-shell structure composed of two types of acrylic rubbers. Particularly preferably, the core layer is n-butyl acrylate and the shell layer is methyl methacrylate. This is sold by Aika Kogyo Co., Ltd. as Zephiace RTM F-351. Examples of the silicone fine particles include organopolysiloxane crosslinked powder, linear dimethylpolysiloxane crosslinked powder, etc. Examples of the composite silicone rubber include those in which the surface of the silicone rubber is coated with a silicone resin (e.g., polyorganosilsesquioxane resin). Among these fine particles, particularly preferred are silicone rubber of linear dimethylpolysiloxane crosslinked powder or composite silicone rubber fine particles of silicone resin-coated linear dimethylpolysiloxane crosslinked powder. These may be used alone or in combination of two or more. Preferably, the shape of the rubber powder is spherical, which causes less thickening of the viscosity after addition.

[0020] [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, they include 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, they are silica, alumina, and talc. These inorganic fillers may be used as a mixture of two or more.

[0021] [(B) Curing compound] The liquid crystal sealing agent of the present invention contains a curing compound (hereinafter also simply referred to as "component (B)") as component (B). Component (B) is not particularly limited as long as it is a compound that cures by light, heat, etc. Examples thereof include compounds having a (meth)acrylic group, compounds having a thiol group, compounds having an epoxy group, compounds having a maleimide group, etc.

[0022] [Compound having a (meth)acrylic group] Examples of the compound having a (meth)acrylic group include (meth)acrylate, epoxy (meth)acrylate, urethane (meth)acrylate, polybutadiene compounds having a (meth)acrylic group, and the like.

[0023] [(Meth)acrylate] (Meth)acrylate specific examples include N-acryloyloxyethylhexahydrophthalimide, acryloylmorpholine, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexane-1,4-dimethanol mono(meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenoxyethyl (meth)acrylate, phenylpolyethoxy (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, o-phenylphenol monoethoxy (meth)acrylate, o-phenylphenol polyethoxy (meth)acrylate, p-cumylphenoxyethyl (meth)acrylate, isobornyl (meth)acrylate, tribromophenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl oxyethyl (meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, bisphenol A polyethoxydi(meth)acrylate, bisphenol A polypropoxydi(meth)acrylate, bisphenol F polyethoxydi(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, tris(acryloxyethyl)isocyanurate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol penta(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane polyethoxytri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, esters of neopentyl glycol and hydroxypivalic acid diacrylate or esters of neopentyl glycol and hydroxypivalic acid ε-caprolactone adduct diacrylate and other monomers can be mentioned.Preferably, o-phenylphenol monoethoxy (meth)acrylate, o-phenylphenol polyethoxy (meth)acrylate, etc. can be mentioned.

[0024] [Epoxy (meth)acrylate] Epoxy (meth)acrylate is obtained by a known method through the reaction of an epoxy resin and (meth)acrylic acid. The epoxy resin as a raw material is not particularly limited, but a bifunctional or higher-functional epoxy resin is preferred. For example, dimer acid-modified epoxy resin, resorcin diglycidyl ether, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, 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, glycidyl amine type epoxy resin, hydantoin type epoxy resin, isocyanurate type epoxy resin, phenol novolac type epoxy resin having a triphenol methane skeleton, and others, such as diglycidyl ether compounds of bifunctional phenols such as catechol and resorcinol, diglycidyl ether compounds of bifunctional alcohols, and their halides, hydrogenated products, etc. can be mentioned. Among these, from the viewpoint of liquid crystal contamination, bisphenol A type epoxy resin and resorcin diglycidyl ether are preferred. Also, the ratio of the epoxy group to the (meth)acryloyl group is not limited and is appropriately selected from the viewpoint of process compatibility. In addition, partial epoxy (meth)acrylate in which a part of the epoxy group is acrylated is preferably used. In this case, the acrylation ratio is preferably about 30 to 70%.

[0025] [Urethane (meth)acrylate] Urethane (meth)acrylate has a flexible skeleton unique to the urethane structure, so the cured product has the properties of being flexible and having low moisture permeability, and can also follow the bending in a flexible display. Therefore, it is preferably used as a curable compound, and it is more preferable to use one having a polyester structure. Urethane (meth)acrylate can be obtained by reacting (a) a polyol, (b) an organic polyisocyanate, and (c) a hydroxyl group-containing (meth)acrylate and synthesizing by a conventional method, and using a catalyst such as a tin compound as necessary. In the synthesis of urethane (meth)acrylate, it is preferable to react 1.1 to 2.0 equivalents of the isocyanate group of component (b) with respect to 1 equivalent of the hydroxyl group of component (a), and it is particularly preferable to react 1.3 to 2.0 equivalents. The reaction temperature is preferably room temperature (25 °C) to 100 °C. It is preferable to react 0.95 to 1.1 equivalents of the hydroxyl group in component (c) per 1 equivalent of the isocyanate group in the reaction product of component (a) and component (b). The reaction temperature is preferably room temperature (25 °C) to 100 °C.

[0026] (a) Specific examples of the polyol include tricyclodecane dimethanol, hydrogenated polybutadiene polyol, dimer diol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, 1,20-icosanediol, 1-methyl-1,8-octanediol, 2-methyl-1,8-octanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, cyclohexane-1,4-dimethanol, polyethylene glycol, polypropylene glycol, bisphenol A poly(n≈2 - 20) ethoxydiol, bisphenol A poly(n≈2 - 20) propoxydiol and other diols (a-1); polyester polyols (a-2) which are reaction products of these diols (a-1) with dibasic acids or their anhydrides (such as succinic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, isophthalic acid, terephthalic acid, phthalic acid or their anhydrides), etc. Preferably, they are polyester polyols and polyols having an aromatic ring, and particularly preferably polyester polyols having an aromatic ring. Examples of the aromatic ring include aromatic hydrocarbon rings such as benzene ring, naphthalene ring, anthracene ring, phenanthroline ring; aromatic heterocyclic rings such as furan ring, pyrrole ring, thiophene ring, pyridine ring, thiazole ring, benzothiazole ring; preferably a benzene ring or a naphthalene ring. Component (a) may be used alone or in combination of two or more.

[0027] (b) Specific examples of the organic polyisocyanate include tolylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-cyclohexylmethane diisocyanate, xylylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, trimethylhexamethylene diisocyanate, dimer diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-diphenylene diisocyanate, and the like. Preferably, tolylene diisocyanate, isophorone diisocyanate, 1,6-hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate can be mentioned.

[0028] (c) Specific examples of the hydroxyl group-containing (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 1,4-butanediol (meth)acrylate, polyethylene glycol mono (meth)acrylate, polypropylene glycol mono (meth)acrylate, pentaerythritol tri (meth)acrylate, ε-caprolactone adduct of 2-hydroxyethyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, and the like. Preferably, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and polyethylene glycol mono (meth)acrylate can be mentioned.

[0029] The lower limit of the polystyrene-equivalent weight average molecular weight in GPC of the urethane (meth)acrylate is preferably 1000 or more, more preferably 2000 or more, particularly preferably 3000 or more, and most preferably 4000 or more. Also, the upper limit is preferably 10000 or less, more preferably 8000 or less, particularly preferably 7000 or less, and most preferably 6000 or less. Being in the above range can maintain good flexibility and moisture permeability while making the viscosity of the liquid crystal sealant within an appropriate range.

[0030] [Polybutadiene compound having a (meth)acrylic group] As the polybutadiene compound having a (meth)acrylic group, for example, TEAI-1000 and TE-2000 manufactured by Nippon Soda Co., Ltd. can be obtained from the market. From the viewpoint of reducing liquid crystal contamination, the lower limit of the number average molecular weight of these polybutadiene compounds is preferably 500, more preferably 750, and particularly preferably 1000. Further, from the viewpoint of handleability, the upper limit of the number average molecular weight is preferably 10000, more preferably 8000, and particularly preferably 6000.

[0031] [Compound having a thiol group] Examples of the compound having a thiol group include methanedithiol, 1,2-dimercaptoethane, 1,2-dimercaptopropane, 2,2-dimercaptopropane, 1,3-dimercaptopropane, 1,2,3-trimercaptopropane, 1,4-dimercaptobutane, 1,6-dimercaptohexane, bis(2-mercaptoethyl)sulfide, 1,2-bis(2-mercaptoethylthio)ethane, 1,5-dimercapto-3-oxapentane, 1,8-dimercapto-3,6-dioxaoctane, 2,2-dimethylpropane-1,3-dithiol, 3,4-dimethoxybutane-1,2 -dithiols, 2-mercaptomethyl-1,3-dimercaptopropane, 2-mercaptomethyl-1,4-dimercaptobutane, 2-(2-mercaptoethylthio)-1,3-dimercaptopropane, 1,2-bis(2-mercaptoethylthio)-3-mercaptopropane, 1,1,1-tris(mercaptomethyl)propane, tetrakis(mercaptomethyl)methane, ethylene glycol bis(2-mercaptoacetate), ethylene glycol bis(3-mercaptopropionate), 1,4-butanediol bis(2-mercaptoacetate), 1,4-butanediol bis(3-mercaptopropionate), trimethylolpropane tris(2-mercaptoacetate), trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), pentaerythritol tetrakis(3-mercaptopropionate), 1,1-dimercaptocyclohexane, 1,4-dimercaptocyclohexane, 1,3-dimercaptocyclohexane, 1,2-dimercaptocyclohexane, dipentaerythritol hexakis(3-mercaptopropionate), dipentaerythritol hexakis(2-mercaptoacetate), 1,2-dimercaptobenzene, 1,3-dimercapto-2-propanol, 2,3-dimercapto-1-propanol, 1,2-dimercapto-1,3-butanediol, hydroxymethyl-tris(mercaptoethylthiomethyl)methane, hydroxyethylthiomethyl-tris(mercaptoethylthio)methane, ethylene glycol bis(3-mercaptopropionate), propylene glycol bis(3-mercaptopropionate), butanediol bis(3-mercaptopropionate), octanediol bis(3-mercaptopropionate), tetraethylene glycol bis(3-mercaptopropionate), ethylene glycol bis(4-mercaptobutyrate), propylene glycol bis(4-mercaptobutyrate), butanediol bis(4-mercaptobutyrate), octanediol bis(4-mercaptobutyrate), trimethylolpropane tris(4-mercaptobutyrate), pentaerythritol tetrakis(4-mercaptobutyrate), ethylene glycol bis(6-mercaptovalerate), propylene glycol bis(6-mercaptovalerate), butanediol bis(6-mercaptovalerate), octanediol bis(6-mercaptovalerate), trimethylolpropane tris(6-mercaptovalerate), pentaerythritol tetrakis(6-mercaptovalerate), 1,6-hexanedithiol, 1,9-nonanedithiol, 1,10-decanedithiol, 4,4'-bis(mercaptomethyl)phenyl sulfide, 2,4'-bis(mercaptomethyl)phenyl sulfide, 2,4,4'-tri(mercaptomethyl)phenyl sulfide, 2,2',4,4'-tetra(mercaptomethyl)phenyl sulfide, 1,3,5-tris[2-(3-mercaptopropionyloxy)ethyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, etc. may be mentioned, and these may be used alone or in combination of two or more kinds., Among these, preferred are trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), dipentaerythritol hexakis(3-mercaptopropionate), 1,3,5-tris[2-(3-mercaptopropionyloxy)ethyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and pentaerythritol tetrakis(3-mercaptobutyrate). More preferably, from the viewpoints of liquid crystal contamination and storage stability at room temperature, 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and pentaerythritol tetrakis(3-mercaptobutyrate) having a secondary thiol structure are particularly preferred. These compounds having a thiol group may be produced by known methods or commercially available ones may be used. Commercially available ones include Karenz MT RTM PE1, BD1, NR1, trimethylolpropane tris(3-mercaptobutyrate), trimethylolethane tris(3-mercaptobutyrate) (all manufactured by Resonac Co., Ltd.), polythiol RTM 340M (manufactured by Toray Fine Chemical Co., Ltd.), pentaerythritol tetrakis(3-mercaptopropionate) (manufactured by SC Organic Chemicals), etc.

[0032] Also, it is also preferable that the compound has a trifunctional or higher thiol group in the molecule. For example, 2,4,4'-tri(mercaptomethyl)phenyl sulfide, 2,2',4,4'-tetra(mercaptomethyl)phenyl sulfide, 1,3,5-tris[2-(3-mercaptopropionyloxy)ethyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris(3-mercaptobutyloxyethyl)1,3,5-triazine-2,4,6(1H,3H,5H)-trione, pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane, etc. can be mentioned. This is because the heat resistance and the like can be improved by increasing the crosslinking density. In addition, especially when used in a liquid crystal display cell, elution into the liquid crystal can be suppressed and high reliability can be realized.

[0033] [Compound having an epoxy group] Examples of the compound having an epoxy group include epoxy resins and polybutadiene compounds having an epoxy group.

[0034] [Epoxy resin] The epoxy resin is not particularly limited, but a bifunctional or higher-functional epoxy resin is preferred. For example, dimer acid-modified epoxy resin, resorcinol diglycidyl ether, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, 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, glycidyl amine type epoxy resin, hydantoin type epoxy resin, isocyanurate type epoxy resin, phenol novolac type epoxy resin having a triphenol methane skeleton, and other diglycidyl ether compounds of bifunctional phenols such as catechol and resorcinol, diglycidyl ether compounds of bifunctional alcohols, and their halides, hydrogenated products, etc. can be mentioned. Among these, from the viewpoint of liquid crystal contamination, bisphenol A type epoxy resin and resorcinol diglycidyl ether are preferred.

[0035] [Polybutadiene compound having an epoxy group] As the polybutadiene compound having an epoxy group, for example, JP-100 and JP-200 manufactured by Nippon Soda Co., Ltd. can be obtained from the market. From the viewpoint of reducing liquid crystal contamination, the lower limit of the number average molecular weight of these polybutadiene compounds is preferably 500, more preferably 750, and particularly preferably 1000. Also, from the viewpoint of handleability, the upper limit of the number average molecular weight is preferably 10000, more preferably 8000, and particularly preferably 6000.

[0036] Component (B) may be used alone or in combination of two or more of the above materials. Component (B) is preferably 78 parts by weight or more and 90 parts by weight or less, more preferably 80 parts by weight or more and 86 parts by weight or less, based on 100 parts by weight of the total amount of the liquid crystal sealant.

[0037] [(C) Photo radical polymerization initiator] The liquid crystal sealant of the present invention may contain a photo radical polymerization initiator (hereinafter, also simply referred to as "component (C)") as component (C). The photo radical polymerization initiator is not particularly limited as long as it is a compound that generates radicals or an acid upon irradiation with ultraviolet rays or visible light and initiates a chain polymerization reaction. For example, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, diethyl thioxanthone, benzophenone, 2-ethyl anthraquinone, 2-hydroxy-2-methyl propiophenone, 2-methyl-〔4-(methylthio)phenyl〕-2-morpholino-1-propane, 2,4,6-trimethylbenzoyl diphenyl phosphine oxide, camphorquinone, 9-fluorenone, diphenyl disulfide, etc. can be mentioned. Specifically, IRGACURE RTM 651, 184, 2959, 127, 907, 369, 379EG, 819, 784, 754, 500, OXE01, OXE02, OXE03, OXE04, DAROCURE RTM 1173, LUCIRIN RTM TPO (all manufactured by BASF), Seikool RTM Z, BZ, BEE, BIP, BBI (all manufactured by Seiko Chemical Co., Ltd.), Kayacure DETX-S (manufactured by Nippon Kayaku Co., Ltd.), etc. can be mentioned. Among these, preferably, IRGACURE RTM OXE01, OXE02, OXE03, OXE04, and Kayacure DETX-S which is a thioxanthone-based initiator. Furthermore, by using an oxime ester-based initiator and a thioxanthone-based initiator in combination, both immediate curability and light-shielding part curability can be achieved, and it is preferable because it can be cured even with visible light. In the liquid crystal sealant of the present invention, when component (C) is used, it is usually 0.001 to 3 parts by weight, preferably 0.01 to 2 parts by weight, per 100 parts by weight of the total amount of the liquid crystal sealant.

[0038] [(D) Thermal curing agent] The liquid crystal sealant of the present invention can improve reactivity by adding a thermal curing agent (hereinafter, also simply referred to as "component (D)") as component (D). Examples of component (D) include, but are not limited to, compounds having a carboxy group bonded to an aromatic ring in the molecule, polyvalent amines, polyvalent phenols, organic acid hydrazides, imidazole compounds, etc. For example, terephthalic acid dihydrazide, isophthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 2,6-pyridine dihydrazide, 1,2,4-benzenetrihydrazide, 1,4,5,8-naphthoic acid tetrahydrazide, pyromellitic acid tetrahydrazide, etc., which are aromatic hydrazides, can be mentioned. Also, in the case of aliphatic hydrazides, for example, formhydrazide, 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-cyclohexane dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, iminodiacetic acid dihydrazide, N,N'-hexamethylenebis semicarbazide, citric acid trihydrazide, nitrilotriacetic acid trihydrazide, cyclohexanetricarboxylic acid trihydrazide, hydantoin skeletons such as 1,3-bis(hydrazinocarbonoethyl)-5-isopropylhydantoin, preferably dihydrazides having a valine hydantoin skeleton (a skeleton in which the carbon atom of the hydantoin ring is substituted with an isopropyl group), tris(1-hydrazinocarbonylmethyl)isocyanurate, tris(2-hydrazinocarbonylethyl)isocyanurate, tris(1-hydrazinocarbonylethyl)isocyanurate, tris(3-hydrazinocarbonylpropyl)isocyanurate, bis(2-hydrazinocarbonylethyl)isocyanurate, etc. can be mentioned.In addition, examples of the imidazole compound include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 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, 2:3 adduct of 2-methylimidazole isocyanurate, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole, and the like. From the balance of the 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, tris(3-hydrazinocarbonylpropyl)isocyanurate, 2,4-diamino-6(2'-methylimidazole(1'))ethyl-s-triazine·isocyanuric acid adduct are preferably used.

[0039] Component (D) may be used alone or in combination of two or more. It is preferable to add Component (D) in an amount of 0.5 parts by weight or more and 15.0 parts by weight or less, more preferably 0.7 parts by weight or more and 10 parts by weight or less, and particularly preferably 2.0 parts by weight or more and 8.0 parts by weight or less, based on 100 parts by weight of Component (B). Further, it is preferable that the particle size of the component (D) is reduced using a jet mill or the like. Specifically, the average particle size is preferably 3.0 μm or less, more preferably 2.5 μm or less, and particularly preferably 2.0 μm or less.

[0040] [(E) Thermal radical polymerization initiator] The liquid crystal sealant of the present invention contains (E) a thermal radical polymerization initiator (hereinafter also simply referred to as "component (E)") and can improve the curing rate and curability. The component (E) is not particularly limited as long as it is a compound that generates radicals by heating and initiates a chain polymerization reaction. Examples include organic peroxides, azo compounds, benzoin compounds, benzoin ether compounds, acetophenone compounds, benzopinacol, etc. Benzopinacol is preferably used. For example, as organic peroxides, Kayameck RTM A, M, R, L, LH, SP-30C, Perkadox CH-50L, BC-FF, Cadox B-40ES, Perkadox 14, Trigonox RTM 22-70E, 23-C70, 121, 121-50E, 121-LS50E, 21-LS50E, 42, 42LS, Kayaster RTM P-70, TMPO-70, CND-C70, OO-50E, AN, Kayabutyl RTM B, Perkadox 16, Kayacarboxylic RTM BIC-75, AIC-75 (manufactured by Kayaku Akzo Co., Ltd.), Permeck RTM N, H, S, F, D, G, Perhexa RTM H, HC, TMH, C, V, 22, MC, Perkure RTM AH, AL, HB, Perbutyl RTM H, C, ND, L, Parkmill RTM H, D, Peroyl RTM IB, IPP, Perocta RTM ND (manufactured by NOF Corporation) and the like are commercially available.

[0041] In addition, as azo compounds, VA-044, 086, V-070, VPE-0201, VSP-1001 (manufactured by Fujifilm Wako Pure Chemical Corporation), etc. are commercially available.

[0042] Preferred as component (E) is a thermal radical polymerization initiator that does not have an oxygen-oxygen bond (-O-O-) and a nitrogen-nitrogen bond (-N=N-) in the molecule. Thermal radical polymerization initiators having an oxygen-oxygen bond (-O-O-) or a nitrogen-nitrogen bond (-N=N-) in the molecule generate a large amount of oxygen and nitrogen when radicals are generated, so that they cure while leaving bubbles in the liquid crystal sealant, which may cause a decrease in adhesive strength, a decrease in moisture permeability, a decrease in properties under a wet heat environment, etc. A benzopinacol-based thermal radical polymerization initiator (including those obtained by chemically modifying benzopinacol) is particularly suitable. 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-tetraphenylethane, 1,2-bis(t-butyldimethylsiloxy)-1,1,2,2-tetraphenylethane, 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, etc. may be mentioned, 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, and particularly preferably 1,2-bis(trimethylsiloxy)-1,1,2,2-tetraphenylethane. The above-mentioned benzopinacol is commercially available from Tokyo Chemical Industry Co., Ltd., FUJIFILM Wako Pure Chemical Corporation, etc. Also, etherification of the hydroxy group of benzopinacol can be easily synthesized by well-known methods. Further, silylation of the hydroxy group of benzopinacol can be obtained by heating the corresponding benzopinacol and various silylating agents under a basic catalyst such as pyridine. Examples of silylating agents include trimethylchlorosilane (TMCS), a generally known trimethylsilylating agent, hexamethyldisilazane (HMDS), N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA), triethylchlorosilane (TECS) as a triethylsilylating agent, and t-butyldimethylsilyl chloride (TBMS) as a t-butyldimethylsilylating agent. These reagents can be easily obtained from the market such as silicon derivative manufacturers. The reaction amount of the silylating agent is preferably 1.0 to 5.0 times the molar amount per 1 mol of the hydroxy group of the target compound, more preferably 1.5 to 3.0 times the molar amount. If it is less than 1.0 times the molar amount, the reaction efficiency is poor and the reaction time becomes long, promoting thermal decomposition. If it is more than 5.0 times the molar amount, separation becomes poor during recovery or purification becomes difficult.

[0043] The content of component (E) is preferably 0.0001 to 5 parts by weight, more preferably 0.0005 to 3 parts by weight, and particularly preferably 0.001 to 1 part by weight in 100 parts by weight of the total amount of the liquid crystal sealant of the present invention.

[0044] [(O) Other components] Additives such as a curing accelerator, a silane coupling agent, a radical polymerization inhibitor, a pigment, a leveling agent, an antifoaming agent, and a solvent can be further incorporated into the liquid crystal sealant of the present invention as required. [Curing accelerator] The liquid crystal sealant of the present invention can be further improved in reactivity by adding a curing accelerator. Examples of the curing accelerator include organic acids. Examples of the organic acid include organic carboxylic acids and organic phosphoric acids, etc., and organic carboxylic acids are preferred. Specifically, aromatic carboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, benzophenone tetracarboxylic acid, and furan dicarboxylic 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, etc. can be mentioned. In the liquid crystal sealing agent of the present invention, when a curing accelerator is used, it is preferably 0.1 to 10 parts by weight, more preferably 1 to 5 parts by weight, per 100 parts by weight of the total amount of the liquid crystal sealing agent.

[0045] [Silane coupling agent] Examples of the above silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N-(2-(vinylbenzylamino)ethyl)-3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloxypropyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, etc. These silane coupling agents are sold by Shin-Etsu Chemical Co., Ltd. as the KBM series, KBE series, etc., and are thus easily available on the market. In the liquid crystal sealing agent of the present invention, when a silane coupling agent is used, 0.05 to 3 parts by weight per 100 parts by weight of the total amount of the liquid crystal sealing agent is suitable.

[0046] [Radical polymerization inhibitor] The radical polymerization inhibitor is not particularly limited as long as it is a compound that reacts with radicals generated from photo radical polymerization initiators, thermal radical polymerization initiators, etc. to prevent polymerization, and quinone-based, piperidine-based, hindered phenol-based, nitroso-based, 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, para-benzoquinone, 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'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 3,9-bis[1,1-dimethyl-2-[β-(3-t-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, aluminum salt of N-nitrosophenylhydroxyamine, trade name AdekaStab LA-81, trade name AdekaStab LA-82 (manufactured by Adeka Corporation), etc. can be mentioned, but it is not limited thereto.Among these, naphthoquinone-based, hydroquinone-based, nitroso-based, and piperazine-based radical polymerization inhibitors are preferred, naphthoquinone, 2-hydroxynaphthoquinone, hydroquinone, 2,6-di-tert-butyl-p-cresol, and Polystop 7300P (manufactured by Hakuto Co., Ltd.) are more preferred, and Polystop 7300P (manufactured by Hakuto Co., Ltd.) is most preferred. As the content of the radical polymerization inhibitor, 0.0001 to 1 part by weight is preferred, 0.001 to 0.5 part by weight is more preferred, and 0.005 to 0.2 part by weight is particularly preferred in 100 parts by weight of the total amount of the liquid crystal sealant of the present invention.

[0047] As an example of the method for obtaining the liquid crystal sealant of the present invention, there is the following method. First, the curable compound, photo radical initiator, thermal radical initiator, and radical polymerization inhibitor are heated and dissolved at 90°C, then cooled to room temperature, and a silane coupling agent, curing agent, curing accelerator, filler, defoaming agent, leveling agent, solvent, etc. are added, and uniformly mixed by a known mixing device, such as a three-roll mill, sand mill, ball mill, etc., and filtered through a metal mesh to produce the liquid crystal sealant of the present invention.

[0048] The liquid crystal display cell manufactured using the liquid crystal sealant of the present invention is formed by oppositely arranging a pair of substrates with predetermined electrodes formed thereon at a predetermined interval, sealing the periphery with the liquid crystal sealant of the present invention, and enclosing liquid crystal in the gap. The type of liquid crystal to be enclosed is not particularly limited. Here, the substrate is composed of a combination of substrates having light transmissibility on at least one of glass, quartz, plastic, silicon, etc. As its manufacturing method, 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, a screen printing device, etc., and then, if necessary, pre-curing is performed at 80 to 120°C. Thereafter, liquid crystal is dropped inside the dam of the liquid crystal sealant, and the other glass substrate is overlaid in a vacuum to form a gap. After gap formation, the liquid crystal display cell of the present invention can be obtained by curing at 90 to 130°C for 30 minutes to 2 hours. When used as a combination of light and heat type, the liquid crystal sealant is irradiated with ultraviolet rays by an ultraviolet irradiation machine for photocuring. The ultraviolet irradiation amount is preferably 500 to 6000 mJ / cm 2 , more preferably 1000 to 4000 mJ / cm 2 (measurement wavelength: 365 nm) of irradiation amount is preferable. Thereafter, if necessary, the liquid crystal display cell of the present invention can be obtained by curing at 90 to 130°C for 30 minutes to 2 hours. The liquid crystal display cell of the present invention thus obtained has no display defect due to liquid crystal contamination and is excellent in adhesiveness and moisture resistance reliability. Examples of the spacer include glass fiber, silica beads, polymer beads, etc. Its diameter varies depending on the purpose, but is usually 2 to 8 μm, preferably 4 to 7 μm. Its usage amount is usually 0.1 to 4 parts by weight, preferably 0.5 to 2 parts by weight, more preferably about 0.9 to 1.5 parts by weight with respect to 100 parts by weight of the liquid crystal sealant of the present invention.

Examples

[0049] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples. Unless otherwise specified, "parts" and "%" in the text are based on weight.

[0050] [Synthesis Example 1] In a flask equipped with a thermometer, a cooling tube, and a stirring device, 776.99 g of a polyester polyol (P-2012 manufactured by Kuraray Co., Ltd., hydroxyl value 54.6 mgKOH / g) of methylpentanediol, adipic acid, and isophthalic acid and 131.68 g of toluene diisocyanate (Coronate T-100 manufactured by Tosoh Corporation, molecular weight 174.2) were charged and reacted at 80°C. The isocyanate content at this time was determined by adding an excess of amine and back-titrating with hydrochloric acid, and it was confirmed that the value was within the range of plus or minus 2% of the residual amount of isocyanate obtained from the calculated value. Next, 0.6 g of methoquinone (polymerization inhibitor), 90.43 g of 2-hydroxyethyl acrylate (molecular weight 116.1), and 0.3 g of dibutyltin dilaurate (catalyst) were added, stirred at 80°C, and the absorption spectrum of the isocyanate group (2280 cm -1 ) was reacted until it disappeared to obtain a urethane acrylate oligomer having a weight average molecular weight of 6300.

[0051] [Synthesis Example 2] 100 parts (0.28 mol) of commercially available benzopinacol (manufactured by Tokyo Chemical Industry) was dissolved in 350 parts of dimethylformaldehyde. To this, 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 were added, the temperature was raised to 70°C, and the mixture was stirred for 2 hours. The obtained reaction solution was cooled, and while stirring, 200 parts of water was added to precipitate the product and deactivate the unreacted silylating agent. The precipitated product was separated by filtration and then washed thoroughly with water. Next, the obtained product was dissolved in acetone, water was added for recrystallization, and purification was performed. 105.6 parts (yield 88.3%) of the target 1,2-bis(trimethylsiloxy)-1,1,2,2-tetraphenylethane was obtained.

[0052] [Examples 1 to 20, Comparative Examples 1 to 4] The curable compound, photo radical initiator, and radical polymerization inhibitor were heated and dissolved at 90°C at the ratios shown in Tables 1 and 2 below, then cooled to room temperature. After adding a silane coupling agent, curing agent, curing accelerator, filler, and thermal radical initiator and stirring, it was dispersed using a three-roll mill and filtered through a metal mesh (635 mesh) to prepare a liquid crystal sealant.

[0053] [Evaluation] [Viscosity][Thixotropy Ratio] The viscosity of the liquid crystal sealants produced in the examples and comparative examples was measured using an R-type viscometer (R115U type viscometer: manufactured by Toki Sangyo Co., Ltd.), a measuring cone of 3°×R7.7, a rotation speed of 5 rpm, and 0.5 rpm, in an atmosphere of 25°C. The thixotropy ratio was calculated using the formula of viscosity at 0.5 rpm / viscosity at 5 rpm. The results are shown in Tables 1 and 2. [Elastic Modulus] The liquid crystal sealants produced in the examples and comparative examples were sandwiched between polyethylene terephthalate (PET) films to form a thin film with a thickness of 100 μm, and then irradiated with ultraviolet light of 3000 mJ / cm 2 (measurement wavelength: 365 nm) using a UV irradiation machine. After that, it was put into an oven and heat-cured at 120°C for 70 minutes. After curing, the PET film was peeled off to obtain a sample. The sample was measured by performing a tensile test using a tensilon universal testing machine (manufactured by A&D Co., Ltd., RTG-1210) at room temperature (25°C) with a test speed of 5 mm / min. The results are described in Tables 1 and 2. [Moisture Permeability] The liquid crystal sealants produced in the examples and comparative examples were sandwiched between polyethylene terephthalate (PET) films to form a thin film with a thickness of 300 μm, and then irradiated with ultraviolet light of 3000 mJ / cm 2 (measurement wavelength: 365 nm) using a UV irradiation machine. After that, it was put into an oven and heat-cured at 120°C for 70 minutes. After curing, the PET film was peeled off to obtain a sample. The moisture permeability of the sample at 60°C and 90% was measured using a moisture permeability measuring machine (manufactured by Lyssy Co., Ltd.: L80-5000). The results are described in Tables 1 and 2. [Shear Adhesion Strength] An alignment film solution (Optomer AL19801-R8 manufactured by JSR Corporation) was spin-coated on a glass substrate, pre-baked on a hot plate at 110°C for 2 minutes, and baked in an oven at 230°C for 20 minutes to obtain an alignment film substrate. 1 wt% of 4-μm glass fibers was added as a spacer to the liquid crystal sealants prepared in the examples and comparative examples, and mixing and stirring were carried out using a planetary stirrer (VMX-360 manufactured by EME). The fabricated alignment film substrate was cut into a rectangle of 25 mm × 45 mm, the sealant adjusted was applied to the central part where two substrates overlapped as shown in Fig. 1, temporarily fixed with clips, and the substrates were bonded together. After irradiating with ultraviolet rays of 3000 mJ / cm 2 (measurement wavelength: 365 nm), it was adhered by heating and curing at 120°C for 70 minutes. The obtained bonded substrate was subjected to a tensile test at room temperature (25°C) and a test speed of 1000 mm / min using a tensilon universal testing machine (RTG-1210 manufactured by A&D Company, Limited), and the maximum load when the substrate was peeled off was measured. The shear adhesion strength was determined by dividing the maximum load at the time of peeling by the area of the sealant. The results are shown in Tables 1 and 2. [Peel adhesion strength] An alignment film solution (Optomer AL19801-R8 manufactured by JSR Corporation) was spin-coated on a glass substrate, pre-baked on a hot plate at 110°C for 2 minutes and baked in an oven at 230°C for 20 minutes to obtain an alignment film substrate. 1 wt% of 4-μm glass fibers was added as a spacer to the liquid crystal sealants prepared in the examples and comparative examples, and mixing and stirring were carried out using a planetary stirrer (VMX-360 manufactured by EME). The prepared liquid crystal sealant was applied onto the fabricated photo-alignment film substrate in a form that reproduced a corner portion with R = 0.5 mm and a length of 1 cm × 1 cm so that the seal width was 0.6 mm, and it was bonded to the opposing photo-alignment film substrate in a vacuum of 1 to 10 Pa. After releasing to the atmosphere, it was irradiated with ultraviolet rays of 3000 mJ / cm 2After irradiating with ultraviolet rays (measurement wavelength: 365 nm), it was adhered by heating and curing in a hot air oven at 120°C for 70 minutes. The obtained bonded substrate was cut into a shape where only the lower substrate assuming the terminal part of the display as shown in Figure 2 protruded, and the lower substrate at a point 4 mm away from the diagonal line of the corner of the display sealing agent applied with a universal testing machine (manufactured by Shimadzu Corporation: Autograph AG-Xplus500N) equipped with a 3 mmφ needle-type terminal was pushed, and the peeling adhesive strength was determined by measuring the maximum load when the bonded substrate peeled off. The results are shown in Tables 1 and 2.

[0054]

Table 1

[0055]

Table 2

[0056] TIFF2025082855000003.tif60170

[0057] From the results in Tables 1 and 2, it was confirmed that the liquid crystal sealing agent of the present invention is excellent in moisture barrier properties and has excellent adhesiveness to stresses in both the shear direction and the peeling direction.

Claims

1. A liquid crystal dropping method liquid crystal sealant containing filler (A) with an average particle diameter of 0.4 μm or less, component (B) a curable compound, component (C) a photo radical polymerization initiator, and component (D) a thermosetting agent, wherein the content of the component (A) is 7 parts by weight or more and 25 parts by weight or less with respect to 100 parts by weight of the component (B), as the component (B), it contains (B-1) a compound having a (meth)acrylic group and (B-2) a compound having a thiol group, A liquid crystal dropping method liquid crystal sealant having an elastic modulus of the cured product at 25 °C measured by a universal testing machine of 2000 MPa or more and less than 4500 MPa.

2. The moisture permeability of the cured product measured under the conditions of 60°C and 90% is 50 g / m ２ ・The liquid crystal sealing agent for the liquid crystal dropping method according to claim 1, wherein the moisture permeability is 50 g / m

3. The liquid crystal dropping method liquid crystal sealant according to claim 1, wherein the component (B-1) contains partial epoxy (meth)acrylate.

4. The liquid crystal dropping method liquid crystal sealant according to claim 3, wherein the component (B-1) contains urethane (meth)acrylate.

5. The liquid crystal dropping method liquid crystal sealant according to claim 1, further containing component (E) a thermal radical polymerization initiator.

6. The liquid crystal dropping method liquid crystal sealant according to claim 5, wherein the component (E) 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.

7. A liquid crystal display panel sealed with the liquid crystal dropping method liquid crystal sealant according to any one of claims 1 to 6.

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