TW201410853A - Liquid-crystal sealing material and liquid-crystal display cell obtained using same - Google Patents

Abstract

Proposed is a liquid-crystal sealing material for liquid-crystal dropping methods which has excellent resistance to liquid-crystal penetration thereinto and is also excellent in terms of general properties required of liquid-crystal sealing materials, such as adhesion strength, and which facilitates the production of a liquid-crystal display cell having excellent long-term reliability. This liquid-crystal sealing material for liquid-crystal dropping methods contains a solid ingredient (I), wherein in cases when the specific gravity of the solid ingredient (I) is expressed by A [g/cm3], the content of the ingredient (I) in the liquid-crystal sealing material by B [g], and the volume of the liquid-crystal sealing material by C [cm3], the A, B, and C satisfy numerical expression (a). In viscosity examination with an E-type viscometer at 25 C under the conditions of 5 rpm and 0.5 rpm, the sealing material has a thixotropic ratio, shown by (viscosity at 0.5 rpm)/(viscosity at 5 rpm), of 1.1-3.0. 0.2<=B/(AC)<=0.4 (a)

Description

Liquid crystal sealing agent and liquid crystal display unit using the liquid crystal sealing agent

The present invention relates to a liquid crystal sealing agent used in a liquid crystal dropping method, and a liquid crystal display unit using the liquid crystal sealing agent. More specifically, it relates to a liquid crystal sealing agent for a liquid crystal dropping method and a liquid crystal display unit using the liquid crystal sealing agent, and the liquid crystal sealing agent for liquid crystal dropping method is excellent in resistance to penetration of liquid crystal into a liquid crystal sealing agent, and is adhered thereto. The liquid crystal sealing agent such as strength is also excellent in general characteristics.

In recent years, as a method of manufacturing a liquid crystal display unit, a so-called liquid crystal dropping method having high mass productivity has been proposed (Patent Documents 1 and 2). Specifically, the liquid crystal display method is a method for manufacturing a liquid crystal display unit, in which a liquid crystal is dropped on the inside of a bank formed of a liquid crystal sealing agent formed on one side of the substrate, and then bonded to the other side. The substrate is then cured by a liquid crystal sealant.

However, in the liquid crystal dropping method, since the liquid crystal and the liquid crystal sealing agent are in contact before the liquid crystal sealing agent is hardened, the liquid crystal sealing agent may be infiltrated due to the pressure caused by the liquid crystal. In the worst case, the liquid crystal sealing is performed. Agent The dam that is formed will collapse and cause problems. Even in a liquid crystal dropping method in which light and heat are used in combination, this problem occurs when there is a portion where a shadow such as a wiring is formed and the ultraviolet ray is not sufficiently irradiated. Further, this is a major problem especially when the liquid crystal sealing agent is hardened only by heat without ultraviolet irradiation. In order to solve this problem, it is necessary to increase the accuracy of the amount of liquid crystal dripping. However, even in the hardening step of the liquid crystal sealing agent, that is, heating, the liquid crystal expands, so that it is difficult to completely suppress the above-described infiltration phenomenon.

Further, in the liquid crystal sealing agent for liquid crystal dropping method, it is necessary to solve various problems such as low liquid crystal contamination, high adhesion strength, high moisture resistance, high heat resistance, and the like, and workability such as storage stability.

In order to solve this problem, various techniques have been proposed.

Patent Document 3 seeks to solve the above problems by using organic bentonite. Although this method has certain results for the penetration of liquid crystal, it is not sufficient.

Patent Document 4 describes a method of performing a B-stage treatment of a liquid crystal sealing agent by using a liquid crystal sealing agent obtained by using fumed silica (fumed silica) or polythiol. However, this method has the disadvantage that the engineering becomes lengthy and it is necessary to have means for this step.

Patent Document 5 discloses a liquid crystal sealing agent for a liquid crystal dropping method which uses a thermal radical polymerization initiator to prevent penetration by increasing the curing rate.

As mentioned above, although the development of liquid crystal sealants is being carried out very hard However, a liquid crystal sealing agent which has excellent penetration resistance, low liquid crystal contamination, high adhesion strength, and the like as a liquid crystal sealing agent is also excellent.

[Previous Technical Literature] (Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. SHO63-179323

Patent Document 2: Japanese Laid-Open Patent Publication No. Hei 10-239694

Patent Document 3: Japanese Patent Laid-Open Publication No. 2010-14771

Patent Document 4: Japanese Laid-Open Patent Publication No. 2011-150181

Patent Document 5: International Publication No. 2011/061910

The present invention provides a liquid crystal sealing agent used in a liquid crystal dropping method, and a liquid crystal display unit using the liquid crystal sealing agent. More specifically, a liquid crystal sealing agent for a liquid crystal dropping method and a liquid crystal sealing agent are used. In the liquid crystal display unit, the liquid crystal of the liquid crystal sealing agent for liquid crystal dropping method is excellent in penetration resistance to a liquid crystal sealing agent, and is excellent in general characteristics of a liquid crystal sealing agent such as adhesion strength.

The present inventors focused on the investigation and found a liquid crystal sealing agent containing a solid component (I), and the specific gravity A [g/cm ³ ] of the solid component (I) in the liquid crystal sealing agent, and the solid component (I) When the content B [g] in the liquid crystal sealing agent and the volume C [cm ³ ] of the liquid crystal sealing agent have a certain relationship, the infiltration resistance (impedance resistance) is excellent, and the present invention has finally been completed.

In addition, in the present specification, the term "(meth)acrylic acid" means "acrylic acid and/or methacrylic acid", and "(meth)acrylonitrile group means "acrylic acid and/or methacrylic acid".醯基". Further, the "liquid crystal sealing agent for liquid crystal dropping method" may be simply referred to as "liquid crystal sealing agent".

That is, the present invention relates to the following 1) to 12).

1) A liquid crystal sealing agent for a liquid crystal dropping method, wherein the liquid crystal sealing agent contains a solid component (I), and when the specific gravity of the solid component (I) is A [g/cm ³ ], the solid component (I) is When the content in the liquid crystal sealing agent is B [g] and the volume of the liquid crystal sealing agent is defined as C [cm ³ ], the above A, B, and C satisfy the following formula (a), and the E type viscosity is used. Among the viscosity values measured at 25 rpm and 5 rpm and 0.5 rpm, the Thixotropic Ratio expressed by the viscosity at a viscosity of 0.5 rpm at 0.5 rpm was 1.1 to 3.0, 0.2 ≦ B / (A). ×C)≦0.4‧‧‧(a).

(2) The liquid crystal sealing agent for liquid crystal dropping method according to the above 1), wherein the above A [g/cm ³ ] is 0.85 to 1.10 g/cm ³ .

(3) The liquid crystal sealing agent for liquid crystal dropping method according to the above-mentioned 1), wherein the total amount of the solid component (I) contains 85 mass% or more of the solid content (I-1), and the solid component (I-1) The Shore A hardness is 10 to 70.

4) The liquid crystal sealing agent for liquid crystal dropping method according to the above 3), wherein The solid component (I-1) is one or two or more solid components selected from the group consisting of ruthenium rubber, styrene rubber, styrene-olefin rubber, and acrylic rubber.

(5) The liquid crystal sealing agent for liquid crystal dropping method according to the above 1), which comprises: (meth)acrylated epoxy resin (II), thermosetting agent (III), and thermal radical polymerization initiator ( IV).

6) The liquid crystal sealing agent for liquid crystal dropping method according to the above 5), wherein the (meth)acrylated epoxy resin (II) is resorcin diglycidyl ether ( Methyl) acrylate.

(7) The liquid crystal sealing agent for liquid crystal dropping method according to the above 5), wherein the thermosetting agent (III) is a polyfluorene compound.

(8) The liquid crystal sealing agent for liquid crystal dropping method according to the above 5), wherein the thermal radical polymerization initiator (IV) is 1,2-bis(trimethyldecyloxy)-1,1,2 , 2,-tetraphenylethane.

9) The liquid crystal sealing agent for liquid crystal dropping method according to the above 1), which contains a decane coupling agent (V).

(10) The liquid crystal sealing agent for a liquid crystal dropping method according to the above 1), which comprises an epoxy resin (VI).

(11) A liquid crystal display unit manufacturing method according to any one of the above 1) to 10), wherein the liquid crystal display unit comprising two substrates is formed on one side of the substrate In the method, the liquid crystal is dropped on the inside of the bank formed by the liquid crystal sealing agent, and then the other substrate is bonded, and then the liquid crystal sealing agent for liquid crystal dropping method is cured by heat.

12) A liquid crystal display unit sealed with a hardened material The cured product obtained by curing the liquid crystal sealing agent for liquid crystal dropping method according to any one of the above 1) to 10).

The liquid crystal sealing agent of the present invention is extremely excellent in resistance to penetration of liquid crystal. Therefore, the manufacture of the liquid crystal display unit is facilitated. Further, since the liquid crystal sealing agent such as the adhesive strength is also excellent in general characteristics, the long-term reliability of the completed liquid crystal display unit is high. That is, the present invention enables an excellent liquid crystal display unit to be easily manufactured.

The liquid crystal sealing agent of the present invention is characterized in that it contains a solid component (I), and when the specific gravity of the solid component (I) is A [g/cm ³ ], the solid component (I) is in a liquid crystal sealing agent. When the content is B [g] and the volume of the liquid crystal sealing agent is defined as C [cm ³ ], the above A, B, and C satisfy the following formula (a), 0.2 ≦ B / (A × C) ≦ 0.4‧ ‧‧(a).

From the above mathematical formula, the volume occupancy of the solid component (I) in the liquid crystal sealing agent can be calculated. In other words, if the volume occupancy ratio in the liquid crystal sealing agent is too large, the dispensing property is lowered, and if it is too small, sufficient penetration resistance cannot be obtained. Here, the upper limit of the volume occupancy ratio is 0.4, and the lower limit is 0.2. With this value as the limit, there will be significant differences in efficacy. That is, if the volume occupancy ratio exceeds 0.4, the thixotropic ratio increases, and the linearity of the sealing portion at the time of coating becomes If the difference is less than 0.2, liquid crystal infiltration may occur during bonding. Further, the specific gravity A of the solid component (I) can be measured by a water substitution method (JIS K7112).

Further, the liquid crystal sealing agent of the present invention is characterized by a thixotropic property represented by a viscosity at a viscosity of 5 rpm at 0.5 rpm in a viscosity value measured at 5 rpm and 0.5 rpm using an E-type viscometer at 25 ° C. The ratio is 1.1~3.0. When the thixotropic ratio exceeds 3.0, the linearity at the time of sealing application is deteriorated, and if the thixotropic ratio is less than 1.1, the breaking condition of the sealant is deteriorated. When the breaking condition of the sealant is deteriorated, the following problem occurs: the end point at the time of seal coating becomes a state of being pulled, and the drawing cannot be clearly performed.

In the present specification, the solid component (I) means an organic filler, an inorganic filler or the like which is not related to a chemical reaction. That is, it means that the solid components after the following components are excluded: thermosetting agent (III), thermal radical polymerization initiator (IV), solid hardening accelerator, solid epoxy resin, solid epoxy acrylic acid Ester resin and the like.

Further, the specific gravity A may be calculated from the value in the manufacturer's catalog without using the water substitution method. For example, the specific gravity A when the organic filler and the inorganic filler are mixed can be calculated by the following formula.

A[g/cm ³ ]=specific gravity of organic filler×content ratio of organic filler in solid component (I)+specific gravity of inorganic filler×content of inorganic filler in solid component (I)

This method can be applied even when the solid component (I) is a mixture of three or more components.

The content B [g] of the solid content (I) in the liquid crystal sealing agent, and the volume C [cm ³ ] of the liquid crystal sealing agent are values determined according to the amount of the sample taken arbitrarily, and can be degassed from the vacuum using self/revolution type. In a liquid crystal sealing agent which is sufficiently defoamed by a machine or the like, it is measured by a measuring cylinder and an electron balance.

The above solid component (I) means an organic filler or an inorganic filler.

Examples of the organic filler include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), and butyl rubber (IIR). ), nitrile rubber (NBR), ethylene-propylene rubber (EPM, EP), chloroprene rubber (CR), acrylic rubber (ACM, ANM), chlorosulfonated polyethylene rubber (CSM), polyurethane rubber (PUR) ), rubber (SI, SR), fluororubber (FKM, FPM), polysulfide rubber (Thiokol), etc. These solid components (I) may be used in combination of two or more kinds. Among these solid components (I), ruthenium rubber, styrene rubber, styrene-olefin rubber, and acrylic rubber are preferred.

The above ruthenium rubber is preferably KMP-594, KMP-597, KMP-598 (above manufactured by Shin-Etsu Chemical Co., Ltd.), TREFIL ^RTM E-5500, 9701, EP-2001 (above manufactured by Dow Corning Toray Co., Ltd.), styrene rubber Preferred are RABALON ^RTM T320C, T331C, SJ4400, SJ5400, SJ6400, SJ4300C, SJ5300C, SJ6300C (the above is manufactured by Mitsubishi Chemical Corporation), and styrene-olefin rubber is preferably SEPTON ^RTM SEPS2004, SEPS2063. In addition, in this specification, the superscript "RTM" means a registered trademark.

Further, when the above acrylic rubber is used, it is preferably an acrylic rubber having a core-shell structure composed of two kinds of acrylic rubbers, particularly preferably an acrylic rubber having a core layer of n-butyl acrylate and a shell layer of methyl methacrylate. . This acrylic rubber is ZEFIAC ^RTM F-351 sold by AICA Industries, Ltd.

When the average particle diameter of the organic filler is too large, when a liquid crystal cell having a narrow gap is produced, the gap between the upper and lower glass substrates cannot be smoothly formed. Therefore, the average particle diameter of the organic filler is preferably 20 μm or less. It is preferably 10 μm or less. The particle size can be determined by electron microscopy.

Examples of the inorganic filler of the solid component (I) include molten cerium oxide, crystalline cerium oxide, cerium carbide, cerium nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, and calcium sulfate. Mica, talc, clay, alumina, magnesia, zirconia, aluminum hydroxide, magnesium hydroxide, calcium citrate, aluminum silicate, lithium aluminum niobate, zirconium silicate, barium titanate, glass fiber, carbon fiber, two Molybdenum sulfide, asbestos, etc., preferably molten cerium oxide, crystalline cerium oxide, cerium nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, cerium Calcium acid or aluminum citrate is more preferably molten cerium oxide, crystalline cerium oxide, aluminum oxide or talc. These inorganic fillers may be used in combination of two or more kinds. If the average particle size of the inorganic filler is too large, it is manufactured. In the case of a liquid crystal cell having a narrow gap, the gap between the upper and lower glass substrates may not be formed smoothly. Therefore, the average particle diameter of the inorganic filler is preferably 3 μm or less, and preferably 2 μm or less. The particle size can be determined by a laser diffraction/scattering particle size distribution analyzer (dry type) (manufactured by SEISHIN Co., Ltd.; LMS-30).

Further, the specific gravity A [g/cm ³ ] of the solid component (I) is preferably 0.85 to 1.10. In this case, the influence imparted by the penetration tolerance is remarkable.

Further, the total amount of the solid component (I) is preferably 85 mass% or more of the solid content (I-1), and the Shore A hardness of the solid component (I-1) is 10 to 70. Further, it is more preferably 90% by mass or more of the solid content (I-1). In addition, the Shore A hardness can be measured by JIS K6253. Here, the solid component (I-1) having a Shore A hardness of 10 to 70 corresponds to the above-mentioned silicone rubber, styrene rubber, styrene-olefin rubber, acrylic rubber, and the like.

In the liquid crystal sealing agent of the present invention, if the volume fraction of the solid component (I) satisfies the above formula (a) and the thixotropic ratio satisfies the predetermined range, the other composition is not particularly limited, but preferably contains: (Meth)acrylated epoxy resin (II), thermosetting agent (III), and thermal radical polymerization initiator (IV).

The (meth)acrylated epoxy resin (II) can be obtained by a conventional reaction between an epoxy resin and (meth)acrylic acid. For example, a predetermined equivalent ratio of (meth)acrylic acid or a catalyst (for example, benzyldimethylamine, triethylamine, benzyltrimethylammonium chloride, triphenylphosphine, or the like) is added to the epoxy resin. Triphenyl stibine, polymerization inhibitor (eg, methoquinone, hydroquinone, hydrazine, phenothiazine) And dibutylhydroxytoluene, etc., and obtained by, for example, esterification reaction at 80 to 110 °C. The epoxy resin as the raw material is not particularly limited, and is preferably a bifunctional or higher epoxy resin, and examples thereof include diepoxypropyl ether of resorcinol, bisphenol A epoxy resin, and 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 epoxy resin, epoxy propylamine epoxy resin, hydantoin epoxy resin, isocyanurate An ester type epoxy resin, a phenol novolak type epoxy resin having a trisphenol methane skeleton; other di-epoxypropyl ether compounds such as difunctional phenols, diepoxypropyl ether compounds of difunctional alcohols, and Such halides, hydrides, and the like. Among these epoxy resins, from the viewpoint of liquid crystal contamination, a bisphenol type epoxy resin, a novolak type epoxy resin, and a di-epoxypropyl ether of resorcin are preferable.

The content of the (meth) acrylated epoxy resin (II) is appropriately determined in consideration of the workability and physical properties of the obtained liquid crystal sealing agent, and is usually about 25 to 80% by mass in the liquid crystal sealing agent, preferably 25 to 75 mass%.

The thermosetting agent (III) is not particularly limited, and examples thereof include polyamines, polyhydric phenols, anthraquinone compounds, and the like, and a polyfluorene compound is particularly suitably used. example For example, the following substances of aromatic hydrazine: p-xylylene hydrazide, m-xylylene hydrazine, 2,6-naphthoic acid diterpene, 2,6-pyridine dihydrazine, 1, 2, 4-Benzene triazole, tetramethyl sulfonium 1,4,5,8-naphthoic acid, pyromellitic acid, and the like. Further, examples of the aliphatic hydrazine compound include: formazan, acetamidine, acetamidine, acetonide, propylene dioxime, butyl hydrazine, pentane quinone, hexamidine, and gin. Anthraquinone, 1,4-cyclohexanedipine, dihydroxybutanediamine, hydroxybutanediamine, iminodiethylenediazine, N,N'-hexamethylenebiscarbazone ( N,N'-hexamethylene bis(semicarbazide)), hydroxypropane trimethyl hydrazine, trimethyl acetoxyacetate, cyclohexane trimethyl hydrazine; 1,3-bis(decylcarbonylethyl)-5-isopropyl 1,3-bis(hydrazinocarboethyl-5-isopropylhydantoin) and the like have an intramethylene uregar skeleton, preferably a guanamine carbendazim skeleton (the carbon atom of the uremone ring is isopropyl group) a substituted ruthenium compound; ginseng (1-mercaptocarbonylmethyl) isocyanurate, ginseng (2-mercaptocarbonylethyl) isocyanurate, ginseng (3-mercaptocarbonyl) Base) isocyanurate, bis(2-mercaptocarbonylethyl) isocyanurate, and the like. From the standpoint of the balance between the hardening reactivity and the latent potential, it is preferably meta-xylylene, propylene dioxime, hexamethylene dioxime, ginseng (1-mercaptocarbonylmethyl) isocyanurate. , ginseng (2-mercaptocarbonylethyl) isocyanurate, ginseng (3-mercaptocarbonylpropyl) isocyanurate, especially ginseng (2-mercaptocarbonylethyl) isocyanuric acid ester. When the total amount of the (meth)acrylated epoxy resin (II) is 100 parts by mass, the content of the heat-curing agent (III) is preferably 30 to 50 parts by mass, more preferably 35. ~45 mass, can also be used in combination of two or more.

The thermal radical polymerization initiator (IV) is not particularly limited as long as it is a compound which generates a radical by heating and initiates a chain polymerization reaction, and examples thereof include an organic peroxide, an azo compound, and a benzene. The acylo compound, the benzoin ether compound, the acetophenone compound, tetraphenyl-1,2-ethylene bromide, etc., are preferably used as tetraphenyl-1,2-ethanediol. For example, organic peroxides are available in the following commercial products: Kayamek ^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; Kayaester ^RTM P-70, TMPO-70, CND-C70, OO-50E, AN; Kayabutyl ^RTM B; Perkadox 16; Kayacarbon ^RTM BIC-75, AIC-75 (above manufactured by Kayaku Akzo Co., Ltd.); Permek ^RTM N, H, S, F, D, G; Perhexa ^RTM H, HC, TMH, C, V, 22, MC, Percure ^RTM AH, AL, HB, Perbutyl ^RTM H, C, ND, L, Percumyl ^RTM H, D, Peroyl ^RTM IB, IPP, Perocta ^RTM ND (above manufactured by Nippon Oil Co., Ltd.). Further, the azo compound can be obtained from the following commercially available products: VA-044, V-070, VPE-0201, VSP-1001 (the above is manufactured by Wako Pure Chemical Industries Co., Ltd.). Further, from the viewpoint of reactivity and solubility to liquid crystal, a compound represented by the following formula (1) is particularly preferably used.

In the formula (1), Y ¹ and Y ² each independently represent a hydrogen atom, a phenyl group or a ruthenium atom; and R ¹ to R ⁶ each independently represent a hydrogen atom or a straight or branched chain having 1 to 4 carbon atoms; Alkyl; X ¹ to X ⁴ each independently represent a hydrogen atom, a methyl group, an ethyl group, a methoxy group, an ethoxy group, a phenoxy group or a halogen atom; however, when Y ¹ or Y ² is a hydrogen atom, respectively R ¹ to R ³ or R ⁴ to R ⁶ bonded to Y ¹ or Y ² are absent.

In the above formula (1), Y ¹ and Y ² each independently represent a hydrogen atom, a phenyl group or a ruthenium atom, and preferably at least one of them is a ruthenium atom, and particularly preferably both are ruthenium atoms. In the above formula (1), a linear or branched alkyl group having 1 to 4 carbon atoms in R ¹ to R ⁶ (hereinafter sometimes referred to simply as C1 to C4 alkyl group) may, for example, be a methyl group or a methyl group. Base, n-propyl, isopropyl, tert-butyl, and the like. Further, examples of the halogen atom in X ¹ to X ⁴ include a fluorine atom, a chlorine atom, and a bromine atom.

When Y ¹ or Y ² in the formula (1) is other than a hydrogen atom, R ¹ R ² R ³ Y ¹ - or R ⁴ R ⁵ R ⁶ Y ² - is preferably a phenyl group or 1 to 3 C1~ a phenyl group substituted with a C4 alkyl group, or a di C1~C4 alkyl fluorenyl group or a tri C1~C4 alkyl fluorenyl group, more preferably a di C1~C4 alkyl fluorenyl group or a tri C1~C4 alkyl fluorenyl group, more preferably Three C1~C4 alkyl fluorenyl groups.

In the two or three C1~C4 straight or branched alkyl fluorenyl groups of R ¹ R ² R ³ Y ¹ -, R ⁴ R ⁵ R ⁶ Y ² - of the formula (1), two or three C1~ The C4 alkyl group may be the same or different, and examples of the fluorenyl group include a di-C1-C4 alkyl fluorenyl group such as a dimethyl fluorenyl group, a diethyl fluorenyl group or a methyl ethyl fluorenyl group; and a trimethyl fluorenyl group. And a tri-C1-C4 alkyl fluorenyl group such as a triethyl fluorenyl group, a dimethylethyl fluorenyl group or a tert-butyldimethyl fluorenyl group. Among these alkyl fluorenyl groups, the most preferred is a tri-C1 to C4 alkyl fluorenyl group, and more preferably a trimethyl fluorenyl group.

X ¹ to X ^{4 of the} formula (1) each independently represent a hydrogen atom, a methyl group, an ethyl group, a methoxy group, an ethoxy group, a phenoxy group or a halogen atom, and preferably all of X ¹ to X ⁴ are a hydrogen atom. The situation.

Specific examples of the compound represented by the formula (1) include tetraphenyl-1,2-ethanediol (Benzopinacol) and 1,2-dimethoxy-1,1,2,2-tetraphenylbenzene. Ethylethane, 1,2-diethoxy-1,1,2,2-tetraphenylethane, 1,2-diphenoxy-1,1,2,2-tetraphenylethane, 1,2-Dimethoxy-1,1,2,2-tetrakis(4-methylphenyl)ethane, 1,2-diphenoxy-1,1,2,2-tetra (4- Methoxyphenyl)ethane, 1,2-bis(trimethyldecyloxy)-1,1,2,2-tetraphenylethane, 1,2-bis(triethyldecyloxy) -1,1,2,2-tetraphenylethane, 1,2-bis(t-butyldimethylmethoxy)-1,1,2,2-tetraphenylethane, 1-hydroxyl -2-trimethyldecyloxy-1,1,2,2-tetraphenylethane, 1-hydroxy-2-triethyldecyloxy-1,1,2,2-tetraphenylethane , 1-hydroxy-2-tert-butyldimethyloxyl-1,1,2,2-tetraphenylethane, etc., preferably 1-hydroxy-2-trimethyldecyloxy-1 1,1,2,2-tetraphenylethane, 1-hydroxy-2-triethyldecyloxy-1,1,2,2-tetraphenylethane, 1-hydroxy-2-t-butyl Dimethyl decyloxy-1,1,2,2-tetraphenylethane, 1,2-bis(trimethyldecyloxy)-1,1,2,2-tetraphenylethane, more Good is 1-hydroxy-2-trimethyldecyloxy-1,1,2,2-tetraphenylethane, 1,2-bis(trimethyldecyloxy)-1,1,2,2-tetra Phenylethane. However, the structure of the formula (1) is not limited to these compounds. Further, two or more kinds may be used in combination.

Among the above thermal radical polymerization initiators (IV), tetraphenyl-1,2-ethanediol is sold by Tokyo Chemical Industry Co., Ltd., Wako Pure Chemical Industries Co., Ltd., and the like. Further, a compound obtained by etherifying a hydroxyl group of tetraphenyl-1,2-ethanediol can be easily synthesized by a conventional method. Further, a compound obtained by subjecting a hydroxyl group of tetraphenyl-1,2-ethanediol to oxime etherification can be carried out by using a corresponding tetraphenyl-1,2-ethanediol under an alkaline catalyst such as pyridine. It is obtained by a method of heating with various decylating agents. The decylating agent may, for example, be generally known as a decylating agent: trimethyl chloroalkylating agent (TMCS), hexamethyldioxane (HMDS), N, O- Bis(trimethyldecyl)trifluoroacetamide (BSTFA); triethylsulfonating agent, also known as triethylchlorodecane (TECS); or tert-butyl dimethyl decylating agent, tert-butyl Base decane (TBMS) and the like. These reagents can be easily obtained on the market such as hydrazine derivative manufacturers. The reaction amount of the alkylating agent is preferably 1.0 to 5.0 moles per mole of the hydroxyl group of the target compound. More preferably, it is 1.5 to 3.0 times more. If it is less than 1.0 times mole, the reaction efficiency is poor and the reaction time is long, so that thermal decomposition is promoted. If it is more than 5.0 times moles, the separation is poor at the time of recovery and it is difficult to purify.

Examples of the basic catalyst include pyridine and triethylamine. The alkaline catalyst has the following effects: it captures hydrogen chloride generated during the reaction, and the reaction system It is more alkaline, or hydrogen which attracts hydroxyl groups, and promotes the reaction more. The content of the basic catalyst may be 0.5 times or more with respect to the hydroxyl group to be reacted, and may be used as a solvent.

As the solvent, a nonpolar organic solvent such as hexane, ether or toluene is preferred because it does not participate in the reaction. Further, the following polar solvents are also preferred: pyridine, dimethylformamide (DMF), dimethyl hydrazine (DMSO), tetrahydrofuran (THF), acetonitrile and the like. The content of the solvent is preferably such that the weight concentration of the solute is 5 to 40%. Further preferably, it is 10 to 30%. If it is less than 5%, the reaction becomes slow, and decomposition due to heat is promoted so that the yield is lowered. If it is more than 40%, by-products become large and the yield falls.

The above thermal radical polymerization initiator (IV) preferably has a fine particle size and is uniformly dispersed. When the average particle diameter of the thermal radical polymerization initiator (IV) is too large, when a liquid crystal display unit having a narrow gap is produced, a problem such as a gap cannot be formed smoothly when the upper and lower glass substrates are bonded together, and thus the average particle size is obtained. The diameter is preferably 5 μm or less, and more preferably 3 μm or less. Further, the particle diameter may be made fine without limitation, and usually the lower limit is about 0.1 μm. The particle size can be determined by a laser diffraction/scattering particle size distribution analyzer (dry type) (manufactured by SEISHIN Co., Ltd.; LMS-30).

When the total amount of the liquid crystal sealing agent of the present invention is 100 parts by mass, the content of the thermal radical polymerization initiator (IV) is preferably 0.0001 to 10 parts by mass, more preferably 0.0005 to 7 parts by mass. Particularly preferred is 0.001 to 3 parts by mass.

In the liquid crystal sealing agent of the present invention, a decane coupling agent (V) can be used to improve the adhesion strength or improve the moisture resistance reliability. As the decane coupling agent, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, and 3-glycidoxypropylmethyl are mentioned. Diethoxy decane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, N-phenyl-γ-aminopropyltrimethoxydecane, N-(2-aminoethyl 3-aminopropylmethyldimethoxydecane, N-(2-aminoethyl) 3-aminopropylmethyltrimethoxydecane, 3-aminopropyltriethoxydecane , 3-thiopropyltrimethoxydecane, vinyltrimethoxydecane, N-(2-(vinylbenzylamino)ethyl)3-aminopropyltrimethoxydecane hydrochloride, 3-methacryloxypropyltrimethoxydecane, 3-chloropropylmethyldimethoxydecane, 3-chloropropyltrimethoxydecane, and the like. These decane coupling agents are commercially available from Shin-Etsu Chemical Co., Ltd., etc., such as the KBM series and the KBE series, and thus can be easily obtained from the market. When the total amount of the liquid crystal sealing agent of the present invention is 100% by mass, the content of the decane coupling agent (V) in the liquid crystal sealing agent is preferably 0.05 to 3% by mass.

In the liquid crystal sealing agent of the present invention, the epoxy resin (VI) can be further used to improve the adhesion strength. The epoxy resin (VI) is not particularly limited, and is preferably one which is less polluting or solubility to liquid crystal. Examples of suitable epoxy resins include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and resorcinol (Resorcin). Oxypropyl propyl ether, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, bisphenol F novolak type epoxy resin, Epoxy epoxy resin, aliphatic chain epoxy resin, glycidyl ester epoxy resin, epoxy propylamine epoxy resin, intramethylene urea resin, isocyanurate epoxy resin a phenol novolak type epoxy resin having a trisphenol methane skeleton; other di-epoxypropyl ether compounds such as difunctional phenols, diepoxypropyl ether compounds of difunctional alcohols, and halides thereof, Hydride, etc.

The content of the epoxy resin (VI) is appropriately determined in consideration of the workability and physical properties of the liquid crystal sealing agent, and is usually about 25 to 80% by mass, preferably 25 to 75% by mass in the liquid crystal sealing agent.

In the liquid crystal sealing agent of the present invention, a monomer and/or an oligomer of (meth) acrylate may be further used as needed. Examples of such a monomer or oligomer include a reaction product of dipentaerythritol and (meth) acrylate, a reaction product of dipentaerythritol-caprolactone and (meth) acrylate, and the like. As long as it is low in pollution to the liquid crystal, there is no particular limitation.

The liquid crystal sealing agent of the present invention may be further formulated as needed: a photoradical polymerization initiator, an organic acid or a hardening accelerator such as imidazole; or an additive such as a pigment, a leveling agent, an antifoaming agent, or a solvent. .

As an example of the method of obtaining the liquid crystal sealing agent of the present invention, there are the methods shown below. First, in the (meth) acrylated epoxy resin (II), the epoxy resin (VI) is heated and dissolved as needed, and after cooling to room temperature, a solid component (I) and a heat hardener added as needed are added. (III), thermal radical polymerization initiator (IV), decane coupling agent (V), antifoaming agent, leveling agent, solvent The liquid crystal sealing agent of the present invention can be produced by uniformly mixing by a conventional mixing device such as a three-roll mill, a sand mill, a ball mill or the like, and filtering with a metal mesh.

In the liquid crystal display unit of the present invention, a pair of substrates on which a predetermined electrode is formed on a substrate are disposed to face each other at a predetermined interval, and the liquid crystal sealing agent of the present invention seals the periphery and seals the liquid crystal in the gap. to make. The type of liquid crystal to be enclosed is not particularly limited. Here, the substrate is composed of a substrate having a combination of at least one light transmissive property, and the substrate is made of glass, quartz, plastic, tantalum or the like. In the liquid crystal sealing agent of the present invention, a spacer such as a glass fiber (gap control material) is added to the liquid crystal sealing agent of the present invention, and the liquid crystal sealing agent is applied by using a dispenser or a screen printing device. On one side of the pair of substrates, pre-hardening is carried out at 80 ° C to 120 ° C as needed. Thereafter, the liquid crystal was dropped on the inner side of the bank formed of the liquid crystal sealing agent, and the other substrate was laminated in a vacuum to form a gap. After the gap is formed, it is cured at 90 ° C to 130 ° C for 1 to 2 hours, whereby the liquid crystal display unit of the present invention can be obtained. The liquid crystal display unit of the present invention obtained in this manner does not cause display failure due to liquid crystal contamination, and is excellent in adhesion and moisture resistance reliability. The spacer may, for example, be glass fiber, cerium oxide beads, polymer beads or the like. The diameter of the spacer varies depending on the purpose, and is usually 2 to 8 μm, preferably 4 to 7 μm. The content of the spacer is usually about 0.1 to 4% by mass, preferably about 0.5 to 2% by mass, more preferably about 0.9 to 1.5% by mass, based on 100 parts by mass of the liquid crystal sealing agent of the present invention.

The liquid crystal sealing agent of the present invention has excellent resistance to liquid crystal infiltration, and does not cause liquid crystal infiltration or breakage of the sealing portion even in the substrate bonding step and the heating step in the liquid crystal dropping method. Therefore, it is possible to produce a stable liquid crystal display unit. Further, since the volume fraction of the solid component (I) is high, the elution of the constituent components toward the liquid crystal is extremely small, and the display failure of the liquid crystal display unit can be reduced. Moreover, since it is excellent in storage stability, it is suitable for manufacture of a liquid crystal display unit. In addition, since the cured product of the liquid crystal sealing agent of the present invention is excellent in various cured properties such as adhesion strength, heat resistance, and moisture resistance, it is possible to produce a liquid crystal having excellent reliability by using the liquid crystal sealing agent of the present invention. Display unit. Further, the liquid crystal display unit produced by using the liquid crystal sealing agent of the present invention has sufficient characteristics such as high voltage holding ratio and low ion density as a liquid crystal display unit.

[Examples]

Hereinafter, the present invention will be described in detail by way of Experimental Examples and Examples, but the present invention is not limited by the examples. In addition, “parts” and “%” in this document refer to the quality standard unless otherwise stated.

[Synthesis Example 1] [Synthesis of a full acrylate of resorcinol diepoxypropyl ether]

181.2 g (EX-201, manufactured by Nagase ChemteX Co., Ltd.) of resorcinol diglycidyl ether (DIGLYCIDYLRESORCINOLETHER) was dissolved in 266.8 g of toluene, and 0.8 g of dibutylhydroxytoluene was added thereto as a polymerization inhibitor. Warm to 60 °C. Thereafter, 100% equivalent of C is added to the epoxy group. 117.5 g of the olefinic acid was further heated to 80 ° C, and 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 to obtain a reaction liquid. The reaction liquid was washed with water, and toluene was distilled off, whereby 293 g of an epoxy acrylate of the target succinyl diepoxypropyl ether was obtained. The equivalent of the reactive group of the obtained epoxy acrylate was 183 in theory.

[Synthesis Example 2] Synthesis of [1,2-bis(trimethyldecyloxy)-1,1,2,2,-tetraphenylethane]

100 parts (0.28 mol) of commercially available tetraphenyl-1,2-ethanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 350 parts of acetone (Dimethylformaldehyde). To this was added 32 parts (0.4 mol) of pyridine as a basic catalyst, and 150 parts (0.58 mol) of BSTFA (manufactured by Shin-Etsu Chemical Co., Ltd.) as a decylating agent, and the mixture was heated to 70 ° C and stirred for 2 hours. The obtained reaction liquid was cooled, and while stirring, 200 parts of water was added to precipitate the product while deactivating the unreacted decylating agent. After the precipitated product was separated by filtration, it was sufficiently washed with water. Then, the obtained product was dissolved in acetone, and water was added thereto to recrystallize and purify. 105.6 parts of the target 1,2-bis(trimethyldecyloxy)-1,1,2,2,-tetraphenylethane was obtained (yield 88.3%).

Analysis by HPLC (High Speed Liquid Column Chromatography) gave a purity of 99.0% (area percentage).

[Examples 1 to 4, Comparative Example 1]

The acrylated epoxy resin (II) and the epoxy resin (VI) in the amounts shown in Table 1 below were heated and mixed, and after cooling, the solid component (I) and the thermal hardener were added. (III), a thermal radical polymerization initiator (IV), a decane coupling agent (V), and a hardening accelerator, which are dispersed by a three-roll mill after being stirred, and filtered by a metal mesh (635 mesh). The liquid crystal sealing agents of Examples 1 to 4 were prepared. Further, the materials shown in Table 1 were prepared by the same procedure to prepare a liquid crystal sealing agent of Comparative Example 1.

Further, the specific gravity of the solid component (I) is calculated by the method described above by taking the specific gravity of the mixing system. Further, the content of the solid content (I) in the liquid crystal sealing agent having a volume of C [cm ³ ] is measured after taking a liquid crystal sealing agent of C [cm ³ ], and multiplied by the content ratio of the solid content (I). And calculate. Further, the measurement was carried out by uniformly combining all of C[cm ³ ] to 100 cm ³ .

In addition, the thixotropy ratio of each liquid crystal sealing agent was measured using the E-type viscometer (manufactured by Toki Sangyo Co., Ltd.), and the viscosity of the liquid crystal sealing agent measured at 25 rpm and 5 rpm and 0.5 rpm was measured. The viscosity at a viscosity of 0.5 rpm at 5 rpm was calculated, thereby obtaining a thixotropic ratio.

(1) KMP-594 (Shin-Etsu Chemical Industry Co., Ltd., primary particle size: 3 μm)

(2) T320C (Mitsubishi Chemical Industry Co., Ltd., primary particle size: used after crushing to 3μm)

(3) SEPS2063 (Kuraray Co., Ltd., primary particle size: used after crushing to 3 μm)

(4) ZEFIAC F-351-S (AICA Industrial Co., Ltd., primary particle size: 0.3 μm)

(5) X-24-9163A (Shin-Etsu Chemical Co., Ltd., primary particle size: 0.11 μm)

(6) KMP-701 (Shin-Etsu Chemical Industry Co., Ltd., primary particle size: 3.5 μm)

(7) Synthesis in Synthesis Example 1

(8) HCIC (manufactured by FINECHEM, Japan, average particle size: used after crushing to 1.5 μm)

(9) Synthesis in Synthesis Example 2

(10) Sila-Ace S-510 (CHISSO Co., Ltd.)

(11) KBM-603 (made by Shin-Etsu Chemical Co., Ltd.)

(12) EX-201 (manufactured by Nagase ChemteX Co., Ltd.)

(13) CIC acid (Shikoku Chemical Industry Co., Ltd., average particle size: used after crushing to 1.5 μm)

The following evaluations were performed on the liquid crystal sealing agents prepared in Examples 1 to 4 and Comparative Example 1. The results are summarized in Table 2.

[Unit gap evaluation]

To 100 g of each of the liquid crystal sealing agents, 1 g of a glass fiber (PF-50S: manufactured by Nippon Electric Glass Co., Ltd.) having a diameter of 5 μm was added as a spacer, and the mixture was stirred and defoamed, and filled in a syringe. The liquid crystal sealing agent filled in the syringe was applied to a glass substrate (470×370×0.7SP30ITO: manufactured by GEOMATEC Co., Ltd.) with an ITO transparent electrode, using a dispenser (SHOTMASTER 300: manufactured by Musashi Engineering Co., Ltd.). A seal pattern and a dummy seal pattern are formed. Then, fine droplets of liquid crystal (JC-5015-LA; manufactured by CHISSO Co., Ltd.) were dropped into the frame of the seal portion pattern. Further, an in-plane spacer (Natoco Spacer KSEB-525F; manufactured by Natoco Co., Ltd.; gap width after bonding was 5 μm) was spread and thermally fixed to another glass substrate on which the rubbing treatment was completed. The substrate was bonded to the substrate on which the liquid crystal was dropped, using a bonding apparatus in a vacuum. After being exposed to the atmosphere to form a gap, it was allowed to stand for 10 minutes, and then heated and hardened in an oven at 120 ° C for 1 hour, and the formation of a cell gap was observed with a polarizing microscope.

Evaluate according to the following benchmarks.

○: A cell gap of 3 μm is uniformly formed in the cell

△: There is a gap of about 4 μm in the unit where no gap can be formed.

×: The seal portion is broken, and the unit cannot be formed.

[seal shape]

Using a dispenser (SHOTMASTER 300: manufactured by Musashi Engineering Co., Ltd.), the liquid crystal sealing agent filled in the syringe was linearly applied under the conditions of a pressure of 400 kPa, a coating speed of 20 mm/sec, a clearance of 50 μm, and a nozzle aperture of 200 μm. Coating, observing the shape of the line at this time, and evaluating according to the following criteria.

○: The deviation of the width of the seal is less than 5%

△: The deviation of the width of the sealing portion is less than 10%

×: The deviation of the width of the seal portion is 10% or more

[Liquid Crystal Sealant Adhesion Strength Test]

To 100 g of the liquid crystal sealing agent, 1 g of glass fibers having a diameter of 3 μm was added as a spacer, and the mixture was stirred and mixed. This liquid crystal sealing agent was applied onto a glass substrate of 50 mm × 50 mm, and a glass piece of 1.5 mm × 1.5 mm was bonded to the liquid crystal sealing agent, and the film was placed in an oven at 120 ° C for 1 hour to be cured. The shear bond strength of the glass piece was measured using a bond tester (SS-30WD, manufactured by Sejin Corporation). The results are shown in Table 2.

As a result of the results of Table 2, the liquid crystal sealing agent of the embodiment of the present invention has good workability, can form a desired cell gap, and is excellent in adhesiveness. In particular, the liquid crystal sealing agents of Examples 1 to 3 showed excellent results in all evaluations. In the liquid crystal sealing agent of Example 4, the specific gravity A [g/cm ³ ] of the solid content (I) is 1.31, and the solid content of the Shore A hardness is 10 to 70 in the total amount of the solid component (I). I-1) does not contain 85% by mass or more, and thus has slightly inferior results.

The liquid crystal sealing agent of the present invention is excellent in the resistance of the liquid crystal to the liquid crystal sealing agent, and is excellent in general characteristics as a liquid crystal sealing agent, such as adhesion strength, and can easily produce a liquid crystal display unit excellent in long-term reliability.

Claims (12)

A liquid crystal sealing agent for a liquid crystal dropping method, wherein the liquid crystal sealing agent contains a solid component (I), and when the specific gravity of the solid component (I) is A [g/cm ³ ], the solid component (I) is sealed in a liquid crystal. When the content in the agent is B [g] and the volume of the liquid crystal sealing agent is defined as C [cm ³ ], the above A, B, and C satisfy the following formula (a), and an E-type viscometer is used. Among the viscosity values measured at 25 rpm and 5 rpm, the viscosity ratio at a viscosity of 0.5 rpm at a viscosity of /5 rpm was 1.1 to 3.0, 0.2 ≦ B / (A × C) ≦ 0.4‧ ‧‧(a). The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, wherein the A[g/cm ³ ] is 0.85 to 1.10 g/cm ³ . The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, wherein the total amount of the solid component (I) contains 85 mass% or more of the solid content (I-1), and the solid component (I-1) The Shore A hardness is 10 to 70. The liquid crystal sealing agent for a liquid crystal dropping method according to claim 3, wherein the solid component (I-1) is one or more solid components selected from the group consisting of ruthenium rubber, styrene rubber, and benzene. Ethylene-olefin rubber, acrylic rubber. The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, which comprises: (meth)acrylated epoxy resin (II), thermosetting agent (III), and thermal radical polymerization initiator (IV) . The liquid crystal sealing agent for liquid crystal dropping method according to claim 5, wherein the (meth)acrylated epoxy resin (II) is a (meth)acrylate compound of resorcinol diglycidyl ether. The liquid crystal sealing agent for liquid crystal dropping method according to claim 5, wherein The aforementioned heat hardener (III) is a polysaccharide compound. The liquid crystal sealing agent for liquid crystal dropping method according to claim 5, wherein the thermal radical polymerization initiator (IV) is 1,2-bis(trimethyldecyloxy)-1,1,2,2 ,-tetraphenylethane. The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, which comprises a decane coupling agent (V). The liquid crystal sealing agent for liquid crystal dropping method according to claim 1, which comprises an epoxy resin (VI). A liquid crystal display unit manufacturing method according to any one of claims 1 to 10, wherein the liquid crystal display unit comprises a liquid crystal display unit comprising two substrates, which is formed on one side of the substrate. After the liquid crystal is dropped on the inside of the bank formed by the sealant, the substrate on the other side is bonded, and then the liquid crystal sealing agent for liquid crystal dropping method is cured by heat. A liquid crystal display unit obtained by curing a liquid crystal sealing agent for a liquid crystal dropping method according to any one of claims 1 to 10, which is obtained by curing a liquid crystal sealing agent according to any one of claims 1 to 10.