TW201930536A - Sealing agent for displays - Google Patents

Abstract

An objective of the present invention is to provide a sealing agent for displays with fast response due to heat, extremely low contamination to liquid crystals through the process, excellent adhesion to organic films such as alignment films, and less deterioration in performance by moisture resistance reliability test. The sealing agent for displays of the present invention contains (A) a compound having a carboxy group bonded to an aromatic ring in the molecule and (B) a curable compound.

Description

   Display Encapsulant   

The invention relates to a sealant for a display, which has a fast response due to heat, has extremely low pollution to liquid crystals through steps, and has excellent adhesion to an organic film such as an alignment film. The resulting degradation is small.

Examples of the display sealant system include a sealant for a liquid crystal display, a sealant for an organic EL display, and an adhesive for a touch panel. What these materials have in common is that they have excellent hardenability, high adhesion regardless of the adherend, and must have excellent humidity and heat resistance.

For example, a liquid crystal sealant will be described below.

In recent years, with the miniaturization of liquid crystal display elements, the metal wiring portion of the array substrate of the liquid crystal display element and the black matrix portion of the color filter substrate will form a light-shielding portion in the liquid crystal sealant that does not illuminate the light, making the package The problem of poor display around is more serious than ever. That is, due to the presence of the light-shielding portion, the primary hardening by light becomes insufficient, and many unhardened components remain in the liquid crystal sealant. In this state, if the secondary hardening step is performed by heating, the dissolution of the unhardened component into the liquid crystal will be promoted by the heating, which will cause display failure near the package.

In order to solve this problem, various reviews have been made to improve thermal reactivity. In the light-shielding portion, an attempt has been made to rapidly react a liquid crystal sealant that has not been sufficiently hardened by light at a low temperature to suppress liquid crystal contamination. For example, Patent Documents 1 and 2 disclose a method using a thermal radical initiator. Furthermore, Patent Documents 3 to 5 disclose methods using a polycarboxylic acid as a hardening accelerator.

However, although these methods improve thermal reactivity, the thermal radical initiator and hardening accelerator used will elute to the liquid crystal and cause a problem of poor display. Moreover, when a carboxylic acid is used as a hardening accelerator, the carboxylic acid which has not participated in the hardening system remains in its original state, causing a problem that the moisture resistance reliability is lowered.

In addition, in recent years, as the bezel of a liquid crystal panel is narrowed, a liquid crystal sealant is often drawn on an alignment film, and a problem of peeling of the liquid crystal panel may occur due to poor adhesion between the liquid crystal sealant and the alignment film. The conventionally used rubbing-type alignment film has problems such as foreign matter and uneven orientation of liquid crystal due to friction generated during the rubbing treatment. In recent years, the rubbing-type alignment film has been oriented toward the light-alignment type. The film is changed. However, the adhesion between the light-alignment-type alignment film and the liquid crystal sealant is usually weak, and the problem of peeling of the liquid crystal panel is more obvious.

In order to solve the problem of adhesiveness between a liquid crystal sealant and an alignment film, various technical proposals have been made. For example, Patent Document 6 proposes a sealant that does not use an inorganic filler, but does not mention a photo-alignment-oriented alignment film. Patent Document 7 proposes a sealing material containing an aliphatic epoxy compound having three or more epoxy groups in one molecule, but does not mention an alignment film of a photo-alignment type.

The problems of the above-mentioned hardenability, moisture resistance reliability, and adhesiveness to different adherends are not limited to liquid crystal sealants, but are considered to be problems of encapsulants for displays.

    (Prior technical literature)         (Patent Literature)    

[Patent Document 1] Japanese Patent Laid-Open No. 2004-126211

[Patent Document 2] Japanese Patent Laid-Open No. 2009-8754

[Patent Document 3] International Publication 2007/138870

[Patent Document 4] Japanese Patent Laid-Open No. 2008-15155

[Patent Document 5] Japanese Patent Laid-Open No. 2009-139922

[Patent Document 6] Japanese Patent Laid-Open No. 2010-85712

[Patent Document 7] Japanese Patent Laid-Open No. 2010-170069

The present invention provides a display encapsulant, which is fast in response to heat, has extremely low pollution to liquid crystals through steps, and has excellent adhesion to an organic film such as an alignment film. Caused by less performance degradation.

As a result of intensive review by the inventors, it was found that a sealing agent for a display containing a compound having a carboxyl group bonded to an aromatic ring in the molecule is excellent in thermal reactivity, and as a result, the liquid crystal contamination can be suppressed, and adhesion And the humidity and heat resistance is also excellent, and the present invention has been completed.

In addition, "(meth) acrylic acid" in this specification means "acrylic acid" and / or "methacrylic acid."

That is, the present invention relates to the following: [1] An encapsulant for a display, which contains a component (A) and a component (B), and the component (A) is a compound having a carboxyl group bonded to an aromatic ring in the molecule. This component (B) is a hardening compound; [2] The encapsulant for a display as described in [1] above, wherein the component (A) is a compound having a carboxyl group, a hydroxyl group, and a hydrogen sulfide group; [3] The encapsulant for a display according to the above [1] or [2], wherein the component (B) is the component (B-1) (meth) acrylic compound; [4] as described in the above [1] to [3] The encapsulant for a display according to any one of the above, wherein the component (B) is a mixture of the component (B-1) and the component (B-2), and the component (B-1) is a (meth) acrylic compound [5] The component (B-2) is an epoxy compound; [5] The encapsulant for a display according to any one of [1] to [4] above, further containing a component (C), and the component (C) is Organic filler; [6] The encapsulant for a display according to any one of [1] to [5], further comprising a component (D), which is an inorganic filler; [7] as described in [1] ] The encapsulant for a display according to any one of [6], further containing component (E), which (E) is a silane coupling agent; [8] The encapsulant for a display according to any one of [1] to [7] above, further comprising a component (F), which is a thermosetting catalyst [9] The packaging agent for a display according to the above [8], wherein the component (F) is an imidazole compound; [10] The packaging for a display according to any one of the above [1] to [9] The agent further contains a component (G), which is a photoradical polymerization initiator; [11] The encapsulant for a display according to any one of [1] to [10] above, further containing a component (H), the component (H) is a thermal radical polymerization initiator; [12] a liquid crystal display, which is sealed with a sealing agent for a display according to any one of [1] to [11].

The encapsulant for a display of the present invention has a fast reaction speed during heat curing, and therefore has sufficient hardening even under wiring that is difficult to illuminate light. Therefore, it is possible to ensure the degree of freedom in wiring design of the panel and easily manufacture high Reliable display panel. In addition, since it has excellent adhesion to different adherends and high humidity and heat resistance, it also contributes to the long-term reliability of the display.

    [(A) Compound having a carboxyl group bonded to an aromatic ring in the molecule]    

The encapsulant for a display of the present invention contains (A) a compound having a carboxyl group bonded to an aromatic ring in the molecule (hereinafter also simply referred to as "component (A)"). Since this compound reacts quickly with an epoxy group, it does not function as a hardening accelerator, but functions as a hardener. Therefore, the carboxyl group does not remain in the reaction system and does not adversely affect the humidity resistance reliability. In addition, because of its high reactivity, the crosslinked density of the cured product is high, and its heat resistance is excellent, so it has excellent long-term reliability.

Moreover, when used in combination with a suitable hardening catalyst, it will also react with acrylic groups. Thereby, an acrylic component which cannot be light-cured under the light-shielding of the wiring can be thermally cured, and an encapsulant having excellent resistance to liquid crystal contamination can be obtained.

Component (A) means a group in which a carboxyl group is directly bonded to an aromatic ring. Here, the aromatic ring means a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, or the like, or a thiophene ring, a furan ring, a pyrrole ring, a thiazole ring, Azole ring, pyrazole ring, imidazole ring, isothiazole ring, iso Azole ring, pyrazole ring, thiadiazole ring, Diazole ring, triazole ring, pyridine ring, da Ring, pyrimidine ring, and pyridine Rings and other heterocyclic rings. From the viewpoint of reactivity, the aromatic ring system is preferably a benzene ring.

The aromatic ring may have a substituent other than the carboxyl group. Examples of the substituent include a halogen atom, another carboxyl group, a carbamoyl group, a sulfo group, an aminesulfonyl group, a hydroxyl group, a hydrogen thio group, an amine group, a cyano group, a dioxo group, a phosphine group, and a phosphino group Group, phosphinoamino group, nitro group, silyl group, fluorenyl group, C1 to C6 alkyl group (may be selected from one or more than one halogen atom, hydroxyl group, carboxyl group, carbamoyl group, sulfo group, and sulfamo group Fluorenyl substituents), C1 to C6 alkoxy (can be substituted with 1 or 2 or more substituents selected from halogen atom, hydroxyl, carboxyl, carbamoyl, sulfo, and sulfamoyl) C1 to C6 sulfoalkyl (may be substituted by 1 or 2 or more substituents selected from halogen atom, hydroxyl, carboxyl, carbamoyl, sulfo and sulfamoyl), C1 to C6 alkyl Thio (can be substituted with one or more substituents selected from halogen atom, hydroxyl, carboxyl, carbamoyl, sulfo, and sulfamoyl), C1 to C6 alkylamino (can be substituted by 1 2 or more substituents selected from halogen atom, hydroxyl group, carboxyl group, carbamoyl group, sulfo group, and sulfamoyl group), or fluorenylamino group, aryloxy group, heterocyclic group, heterocyclic ring Aryloxy, arylsulfur , A heterocyclic thio group, an aryl group, a heterocyclic amino group, a sulfo group aryl acyl, a heterocyclic acyl group sulfo and the like.

Among these substituents, those having a carboxyl group, a hydroxyl group, and a hydrogenthio group are more preferable, and those in which these substituents are directly bonded to an aromatic group are more preferable. This is because these substituents can react with an epoxy group (and in some cases, a (meth) acrylic group), thereby increasing the crosslinking density of the hardened material. Furthermore, from the viewpoint of storage stability, a hydroxyl group is preferred.

When there is only one substituent other than the carboxyl group, the substitution position is preferably the ortho or para position of the carboxyl group, and more preferably the para position. When there are two substituents other than the carboxyl group, the substitution position is preferably at the 2,4-position. The substituent other than the carboxyl group is particularly preferably one substituent, and its substitution position is para.

In addition, in the encapsulant for a display of the present invention, the compounding amount of the component (A) is generally 0.1 to 20% by mass, preferably 0.1 to 10% by mass, and 0.5 It is particularly good to 5 mass%.

Examples of the component (A) include the compounds shown in Table 1.

    [(B) hardening compound]    

The sealing compound for a display of the present invention contains a curable compound (hereinafter also simply referred to as "component (B)") as a component (B).

The component (B) is not particularly limited as long as it is a compound that is hardened by light or heat, but the component (B-1) (meth) acrylic compound (hereinafter also referred to as "component (B-1)") The situation is better.

Here, "(meth) acrylic acid" means "acrylic acid" and / or "methacrylic acid" (the same shall apply hereinafter). Examples of the component (B-1) include (meth) acrylate compounds and (meth) acrylate epoxy compounds.

    [(B-1) (meth) acrylic compound]    

Specific examples of the (meth) acrylate compound include N-propenyloxyethylhexahydrophthalimide, propenylmorpholine, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, cyclohexane-1,4-dimethanol mono (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, Phenyl polyethoxylate (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, o-phenylphenol monoethoxy (meth) acrylate, o-phenylphenol poly Ethoxy (meth) acrylate, p-cumylphenoxyethyl (meth) acrylate, isoamyl (meth) acrylate, tribromophenyloxyethyl (meth) acrylate, ( Dicyclopentyl methacrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tricyclodecanedimethanol (meth) acrylate, bisphenol A polyethoxy Di (meth) acrylate, bisphenol A polypropoxy di (meth) acrylate, bisphenol F polyethylene Di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, ginsyl (propyleneoxyethyl) trimeric isocyanate, neopentyl tetraol (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol Alcohol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, bistrimethylolpropane tetra (methyl) Monomers such as acrylic acid esters, diacrylates of neopentyl glycol and hydroxytrimethylacetate, and diacrylates of ε-caprolactone adducts of neopentyl glycol and hydroxytrimethylacetate. Preferred examples include N-propenyloxyethylhexahydrophthalimide, phenoxyethyl (meth) acrylate, and dicyclopentenyloxy (meth) acrylate. Ethyl ester.

The (meth) acrylic epoxy ester compound can be obtained by a conventional method by reacting an epoxy compound with (meth) acrylic acid. The epoxy compound used as a raw material is not particularly limited, but an epoxy compound having two or more functions is preferred, and examples thereof include resorcinol diglycidyl ether, bisphenol A type epoxy compound, and bisphenol F type Epoxy compounds, bisphenol S epoxy compounds, phenol novolac epoxy compounds, cresol novolac epoxy compounds, bisphenol A novolac epoxy compounds, bisphenol F novolac epoxy compounds, grease Cyclic epoxy compounds, aliphatic chain epoxy compounds, epoxypropyl ester epoxy compounds, epoxypropylamine epoxy compounds, hydantoin epoxy compounds, trimeric isocyanate epoxy compounds Phenol novolak epoxy compounds with a triphenol methane skeleton, other difunctional propyl ethers of difunctional phenols such as catechol, resorcinol, etc., and diepoxys of difunctional alcohols Propyl etherate and halides, hydrides and the like. Among these compounds, a bisphenol A epoxy compound and resorcinol diglycidyl ether are preferred from the viewpoint of liquid crystal contamination. The ratio of the epoxy group to the (meth) acrylfluorenyl group is not limited, and can be appropriately selected from the viewpoint of engineering applicability. In addition, a partially methacrylated (meth) acrylic epoxy ester can be suitably used. The proportion of acrylated at this time is preferably about 30 to 70%.

The component (B-1) may be used alone or as a mixture of two or more. When the component (B-1) is used in the display encapsulant of the present invention, it is generally 5 to 50% by mass, and preferably 5 to 30% by mass in the total amount of the display encapsulant.

    [(B-2) epoxy compound]    

In the aspect of the present invention, it is more preferable that the above-mentioned component (B) further contains the component (B-2) epoxy compound (hereinafter also simply referred to as the component (B-2)).

The epoxy compound is not particularly limited, but an epoxy compound having two or more functions is preferred, and examples thereof include resorcinol diglycidyl ether, bisphenol A type epoxy resin, and bisphenol F type epoxy resin. Bisphenol S epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol F novolac epoxy resin, alicyclic ring Oxygen resin, aliphatic chain epoxy resin, epoxy propyl ester epoxy resin, epoxy propyl amine epoxy resin, hydantoin type epoxy resin, trimer isocyanate type epoxy resin, Phenol novolac epoxy resin of phenol methane skeleton, other difunctional phenol ethers of difunctional phenols such as catechol, resorcinol, etc. These halides, hydrides, etc. From the viewpoint of liquid crystal contamination, among these, bisphenol A type epoxy resin and resorcinol diglycidyl ether are preferred.

The component (B-2) may be used alone or as a mixture of two or more. In the display sealing agent of the present invention, when the component (B-2) is used, it is generally 5 to 50% by mass, and preferably 5 to 30% by mass in the total amount of the display sealing agent.

In addition, in the encapsulant for a display of the present invention, the blending amount of the component (B) is generally 10 to 80% by mass, and preferably 20 to 70% by mass of the encapsulant for a display.

    [(C) Organic filler]    

The display sealing agent of the present invention may contain an organic filler (hereinafter also simply referred to as "component (C)") as the component (C). Examples of the organic filler include urethane fine particles, acrylic fine particles, styrene fine particles, styrene olefin fine particles, and polysiloxane fine particles. Further, the polysiloxane particles are preferably KMP-594, KMP-597, KMP-598 (made by Shin-Etsu Chemical Industry); Trefil ^RTM E-5500, 9701, EP-2001 (made by Dow Corning Toray); urethane The fine particles are preferably JB-800T, HB-800BK (Gensang Industrial Co., Ltd.); the styrene fine particles are preferably Rabalon ^RTM T320C, T331C, SJ4400, SJ5400, SJ6400, SJ4300C, SJ5300C, SJ6300C (manufactured by Mitsubishi Chemical); styrene The olefin fine particles are preferably Septon ^RTM SEPS2004 and SEPS2063.

These organic fillers may be used alone or in combination of two or more. It is also possible to use two or more core shell structures. Among these, acrylic fine particles and polysiloxane fine particles are preferred.

When the above-mentioned acrylic fine particles are used, an acrylic rubber having a core-shell structure containing two types of acrylic rubber is preferred, and a core layer of n-butyl acrylate and a shell layer of methyl methacrylate are particularly preferred. This is sold by Aica Industries Co., Ltd. as Zefiac ^RTM F-351.

Examples of the polysiloxane fine particles include organic polysiloxane crosslinked powder, linear dimethyl polysiloxane crosslinked powder, and the like. In addition, examples of the composite silicone rubber include those in which a surface of the silicone rubber is coated with a silicone resin (for example, a polyorganosilicon silsesquioxane resin). Among these fine particles, particularly preferred is a silicone polymer of a linear dimethylpolysiloxane crosslinked powder or a composite polymer of a linear dimethylpolysiloxane crosslinked powder coated with a silicone resin. Particles of silicone rubber. These fine particles may be used alone or in combination of two or more. In addition, the shape of the rubber powder is preferably a spherical shape with little viscosity increase after the addition. When the component (C) is used in the display encapsulant of the present invention, it is generally 5 to 50% by mass, preferably 5 to 40% by mass, based on the total amount of the display encapsulant.

    [(D) Inorganic filler]    

The sealing agent for a display of the present invention may contain an inorganic filler (hereinafter also simply referred to as "component (D)") as the component (D). Examples of the inorganic fillers included in the present invention include: silicon dioxide, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, mica, talc, clay , Aluminum oxide, magnesium oxide, zirconia, aluminum hydroxide, magnesium hydroxide, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, asbestos, etc. ; The preferred ones can be listed as: fused silica, crystalline silica, silicon nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, silicon Calcium acid, aluminum silicate; silicon dioxide, aluminum oxide and talc are preferred. These inorganic fillers may be used by mixing two or more kinds.

If the average particle diameter of the inorganic filler is too large, when manufacturing a narrow gap liquid crystal display unit, it will become a bad factor such as that the gap cannot be formed well when the upper and lower glass substrates are bonded. 1000 nm or less is preferable, and 300 nm or less is more preferable. The preferable lower limit is about 10 nm, and more preferably about 100 nm. The particle diameter can be measured with a laser diffraction / scattering type particle size distribution measuring device (dry type) (manufactured by Seishin Enterprise; LMS-30).

When an inorganic filler is used in the display encapsulant of the present invention, the inorganic filler is generally 5 to 50% by mass, and preferably 5 to 40% by mass in the total amount of the display encapsulant. When the content of the inorganic filler is less than 5% by mass, the adhesion strength to the glass substrate is low and the moisture resistance reliability is also poor. Therefore, the adhesion strength after moisture absorption may be greatly reduced. In addition, when the content of the inorganic filler is more than 50% by mass, the content of the inorganic filler may be excessive, and it may become difficult to collapse and the gap of the liquid crystal cell may not be formed.

    [(E) Silane coupling agent]    

The display sealing agent of the present invention may be added with a silane coupling agent (hereinafter also simply referred to as "ingredient (E)") as the component (E) to improve the adhesion strength and moisture resistance.

Examples of the component (E) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropylmethyl Diethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N- (2-aminoethyl Group) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxy Silane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methacryl methoxypropyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, and the like. These silane coupling agents have been sold by the Shin-Etsu Chemical Industry Co., Ltd. as KBM series, KBE series, etc., so they can be easily obtained from the market. When the component (E) is used in the display sealing agent of the present invention, it is preferably 0.05 to 3% by mass based on the total amount of the display sealing agent.

    [(F) Hardening catalyst]    

The display sealing agent of the present invention can be added with a hardening catalyst (hereinafter also simply referred to as "ingredient (F)") as a component (F) to improve the reactivity. As described above, the component (A) can also react with an acrylic group by using a hardening catalyst. Therefore, the acrylic component plays a particularly important role when it is not light-cured.

Examples of the curing catalyst include amines and imidazoles, and imidazoles are particularly suitable. Examples of imidazoles include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2- Phenyl imidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2- Undecyl imidazole, 2,4-diamino-6- (2'-methylimidazole (1 ')) ethyl-mesanthine , 2,4-diamino-6- (2'-undecylimidazole (1 ')) ethyl-mesanthine , 2,4-diamino-6- (2'-ethyl-4-methylimidazole (1 ')) ethyl-mesanthine , 2,4-diamino-6- (2'-methylimidazolyl (1 ')) ethyl-mesanthine / Trimeric isocyanate adduct, 2-methylimidazole / trimeric isocyanate 2: 3 adduct, 2-phenylimidazole trimeric isocyanate adduct, 2-phenyl-3, 5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole Wait. Among these, 2,4-diamino-6- (2'-methylimidazolyl (1 ')) ethyl-mesantriol is preferred / Trimeric isocyanate adduct.

    [(G) Photo radical polymerization initiator]    

The encapsulant for a display of the present invention may contain a photoradical polymerization initiator (hereinafter also simply referred to as "component (G)") as a component (G). The photoradical polymerization initiator is not particularly limited as long as it is a compound that initiates a chain polymerization reaction due to the generation of a radical or an acid by irradiation with ultraviolet or visible light, and examples thereof include benzyldimethylketal and 1-hydroxycyclohexyl Phenylketone, diethylthiaxanthone, diphenylketone, 2-ethylanthraquinone, 2-hydroxy-2-methyl propiophenone, 2-methyl- [4- (methylthio) phenyl] -2-morpholinyl-1-propane, 2,4,6-trimethylbenzylfluorenyldiphenylphosphine oxide, camphorquinone, 9- Fluorenone, diphenyl disulfide, etc. Specific examples include: IRGACURE ^RTM 651, 184, 2959, 127, 907, 369, 379EG, 819, 784, 754, 500, OXE01, OXE02, DAROCURE ^RTM 1173, LUCIRIN ^RTM TPO (all of which are manufactured by BASF Corporation) ); SEIKUOL ^RTM Z, BZ, BEE, BIP, BBI (the above are all manufactured by Seiko Chemical Co., Ltd.) and so on.

From the viewpoint of liquid crystal contamination, it is preferable to use a (meth) acrylic group in the molecule. For example, 2-methacrylfluorenyloxyethyl isocyanate and 1- [4- (2 -Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one reaction product. This compound can be produced by the method described in International Publication No. 2006/027982.

When the component (G) is used in the display encapsulant of the present invention, the total amount of the display encapsulant is generally 0.001 to 3% by mass, and preferably 0.002 to 2% by mass.

    [(H) Thermal radical polymerization initiator]    

The encapsulant for a display of the present invention may contain (H) a thermal radical polymerization initiator (hereinafter also referred to simply as "component (H)") to improve the curing speed and hardenability.

The thermal radical polymerization initiator is not particularly limited as long as it is a compound that initiates a chain polymerization reaction by generating free radicals by heating, but examples thereof include organic peroxides, azo compounds, benzoin compounds, and benzoin Ether compounds, acetophenone compounds, benzopinacol and the like, and benzopinacol is suitably used. For example, for organic peroxides, commercially available products such as: Kayamek ^RTM A, M, R, L, LH, SP-30C; Perkadox CH-50L, BC-FF; Kadox 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 (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 (manufactured by Nippon Oil Corporation) and the like.

Furthermore, commercially available products such as VA-044, 086, V-070, VPE-0201, VSP-1001 (manufactured by Wako Pure Chemical Industries, Ltd.) and the like are available for the azo compound.

The content of the component (H) is preferably 0.0001 to 10% by mass, more preferably 0.0005 to 5% by mass, and particularly preferably 0.001 to 3% by mass in the total display encapsulant for display of the present invention.

In the sealing agent for a display of the present invention, additives such as a radical polymerization inhibitor, a thermosetting agent other than the component (A), a pigment, a leveling agent, an antifoaming agent, and a solvent may be further blended as necessary.

    [Free radical polymerization inhibitor]    

The above-mentioned radical polymerization inhibitor is not particularly limited as long as it is a compound that reacts with a radical generated by a photoradical polymerization initiator or a thermal radical polymerization initiator to prevent polymerization, and a quinone-based or piperidine-based compound can be used. , Hindered phenols, nitrosos and so on. Specific examples include naphthoquinone, 2-hydroxynaphthoquinone, 2-methylnaphthoquinone, 2-methoxynaphthoquinone, 2,2,6,6-tetramethylpiperidine-1-oxide, 2 , 2,6,6-tetramethyl-4-hydroxypiperidine-1-oxide, 2,2,6,6-tetramethyl-4-methoxypiperidine-1-oxide, 2,2 , 6,6-tetramethyl-4-phenoxypiperidine-1-oxide, hydroquinone, 2-methylhydroquinone, 2-methoxyhydroquinone, p-benzoquinone, butylhydroxyanisole , 2,6-di-tertiary-butyl-4-ethylphenol, 2,6-di-tertiary-butylcresol, stearyl β- (3,5-di-tertiary-butyl-4-hydroxybenzene Propyl) propionate, 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4,4'-thiobis (3-methyl-6-tert-butyl) Phenol), 4,4'-butylene bis (3-methyl-6-tertiary butylphenol), 3,9-bis [1,1-dimethyl-2- [β- (3-tertiary Butyl-4-hydroxy-5-methylphenyl) propanyloxy] ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, methane- [methylene 3- (3 ', 5'-di-tertiary-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-ginseno (3', 5'-di-tertiary-butyl -4'-hydroxybenzyl)-secondary tris -2,4,6- (1H, 3H, 5H) triketone, p-methoxyphenol, 4-methoxy-1-naphthol, thiodiphenylamine, N-nitrosophenylhydroxylamine aluminum salt , Trade name ADK STAB LA-81, trade name ADK STAB LA-82 (manufactured by Adeka Co., Ltd.), etc., but are not limited to these. Among these, naphthoquinone, hydroquinone, nitroso, and piperidine A radical polymerization inhibitor is preferred, and naphthoquinone, 2-hydroxynaphthoquinone, hydroquinone, 2,6-di-tert-butyl-p-cresol, and Polystop 7300P (manufactured by Bodong Co., Ltd.) are more preferred. , Polystop 7300P (made by Bodong Co., Ltd.) is the best.

The content of the radical polymerization inhibitor is preferably 0.0001 to 1% by mass, more preferably 0.001 to 0.5% by mass, and particularly preferably 0.01 to 0.2% by mass in the total encapsulant for a display of the present invention.

    [Thermal hardener other than the component (A)]    

The thermosetting agent other than the component (A) is a nucleophilic reaction by a non-covalent electron pair or an anion in the molecule, and examples thereof include, but are not limited to, polyamines, polyphenols, and organic hydrazine compounds. . Examples include: dihydrazine terephthalate, dihydrazine isophthalate, dihydrazine 2,6-naphthoate, 2,6-pyridinedihydrazine, 1, 2, 4 -Pyrotrimethylene hydrazine, 1,4,5,8-naphthoic acid tetramethylhydrazine, pyromellitic acid tetramethylhydrazine and the like. Moreover, if it is an aliphatic hydrazine compound, for example, formamidine, hydrazine, hydrazine propionate, dihydrazine oxalate, dihydrazine malonate, dihydrazine succinate, and glutaric acid dihydrate Hydrazine, dihydrazine adipate, dihydrazide pimelate, dihydrazide sebacate, 1,4-cyclohexanedihydrazine, dihydrazide dihydroxysuccinate, dihydrazone dihydroxysuccinate Hydrazine, iminodiacetic acid, dihydrazine, N, N'-hexamethylenebishemipalazine, trimethylhydrazine citrate, trimethylhydrazine nitroacetate, trimethylhydrazine cyclohexanetricarboxylic acid, Hydantoin skeletons such as 3-bis (hydrazinocarbethyl) -5-isopropylhydantoin and the like, and preferred examples thereof include a hydantoin valinate skeleton (carbon of hydantoin ring) Isopropyl substituted skeleton skeleton) bishydrazine compound, ginseng (1-hydrazinocarbonylmethyl) trimer isocyanate, ginseng (2-hydrazinocarbonylethyl) trimer isocyanate, ginseng (1-hydrazinocarbonyl) Ethyl) trimeric isocyanate, ginseng (3-hydrazinocarbonylpropyl) trimeric isocyanate, bis (2-hydrazinocarbonylethyl) trimeric isocyanate, and the like. In terms of the balance between curing reactivity and latentity, diisohydrazine isophthalate, dihydrazine malonate, dihydrazine adipate, and ginseng (1-hydrazinocarbonylmethyl) trimer isocyanate are preferred. , Ginseng (1-hydrazinocarbonylethyl) trimer isocyanate, ginseng (2-hydrazinocarbonylethyl) trimer isocyanate, ginseng (3-hydrazinocarbonylpropyl) trimer isocyanate, the best ones are ginseng (2 -Hydrazinocarbonylethyl) trimeric isocyanate.

The heat curing agent other than the component (A) may be used alone, or two or more kinds may be mixed. In the display sealing agent of the present invention, when a thermosetting agent other than the component (A) is used, it is generally 0.1 to 10% by mass and preferably 0.1 to 5% by mass in the total display sealing agent.

In addition, among the encapsulants for displays of the present invention, those without a hydrazine-based hardener are also one of the preferred types. In this case, the content ratio of the hydrazine-based curing agent is preferably 1.0% by mass or less of the total amount of the display sealing agent, and more preferably, it is substantially not contained.

As an example of a method for obtaining the photocurable resin composition of the present invention, the following method is used. First, the component (G) is heated and dissolved in the component (B) as necessary. Next, after cooling to room temperature, add component (A), optional components (C), (D), (E), (F), (H), defoamer, leveling agent, solvent, etc., By using a conventional mixing device, such as a three-roll mill, a sand mill, a ball mill and the like, uniformly mixing and filtering through a metal screen, the sealing agent for a display of the present invention can be manufactured.

Furthermore, the encapsulant for a display of the present invention is very suitable as an adhesive for a liquid crystal display unit, and particularly suitable as a liquid crystal sealant. When the sealing compound for a display of the present invention is used as a liquid crystal sealant, an example of a liquid crystal display unit is shown below.

A liquid crystal display unit manufactured by using the adhesive for a liquid crystal display unit of the present invention is configured by arranging a pair of substrates having predetermined electrodes formed on the substrate at a predetermined interval from each other, and sealing the liquid crystal sealant of the present invention around the substrate. A liquid crystal is sealed in the gap. The type of the enclosed liquid crystal is not particularly limited. The substrate refers to a substrate made of a combination of at least one of glass, quartz, plastic, and silicon that has translucency. The method is to add a spacer such as glass fiber (gap control material) to the liquid crystal sealant of the present invention, and then apply the liquid crystal sealant to one of the pair of substrates using a dispenser or a screen printing device. After that, quasi-hardening is performed at 80 to 120 ° C if necessary. Then, the liquid crystal is dropped to the inside of the weir of the liquid crystal sealant, and another glass substrate is laminated in a vacuum to form a gap. After the gap is formed, the liquid crystal display unit of the present invention can be obtained by curing at 90 to 130 ° C for 30 minutes to 2 hours. When used as a photothermal combination type, ultraviolet light is irradiated to the liquid crystal sealant portion by an ultraviolet irradiator to harden the light. Based ultraviolet irradiation amount of 500 to 6000 mJ / cm ² irradiation amount of preferably, at / cm ² irradiation amount of 4000 mJ to 1000 is more preferred. Then, if necessary, by hardening at 90 to 130 ° C for 30 minutes to 2 hours, the liquid crystal display unit of the present invention can be obtained. The liquid crystal display unit of the present invention obtained in this way does not exhibit poor display due to liquid crystal contamination, and is one having excellent adhesion and humidity resistance reliability. Examples of the spacer include glass fibers, silica beads, and polymer beads. The diameter varies depending on the purpose, but is generally 2 to 8 μm, and preferably 4 to 7 μm. With respect to 100 parts by mass of the liquid crystal sealant of the present invention, its usage amount is generally 0.1 to 4 parts by mass, preferably 0.5 to 2 parts by mass, and more preferably about 0.9 to 1.5 parts by mass.

The encapsulant for a display of the present invention is very suitable for use in adhesive applications in the fields that require hardenability, adhesion to different adherends, and reliability in moisture and heat resistance. Examples include a liquid crystal sealant, an organic EL encapsulant, and a touch panel adhesive.

[Example]

Hereinafter, the present invention will be described in more detail by examples, but the present invention is not limited by the examples. In addition, "part" and "%" in this article are based on quality unless otherwise noted.

    [Examples 1 to 2 and Comparative Example 1]    

After dissolving the components (B) and (G) by heating at 90 ° C in the proportion shown in Table 1 below, the components were cooled to room temperature, and the components (A), (C), (D), (E), and (F) were added. ), (H), after being stirred, dispersed with a three-roll mill, and filtered with a metal screen (635 mesh) to prepare Examples 1 to 5 of a photocurable resin composition. In addition, component (O-4) was used in place of component (A) to prepare Comparative Example 1.

    [Evaluation]         [Adhesive strength]         (Initial Adhesion Glass)    

To 100 g of the liquid crystal sealant produced in the examples and comparative examples, 1 g of 5 μm glass fiber as a spacer was added, and the mixture was stirred. This liquid crystal sealant was applied on a glass substrate in a manner to reproduce a corner portion of 1 cm × 1 cm, and the opposite glass substrate was bonded together and irradiated with 3000 mJ / cm ² of ultraviolet light by a UV irradiator, and then poured into the glass substrate. The oven was hardened at 120 ° C for 1 hour. A peel tester (bond tester) (manufactured by Nishijin Co., Ltd .: SS-30WD) was used to measure the peeling adhesion strength of the glass substrate by pressing the corners. The intensity is shown in Table 2.

    (Initial Adhesion Light Directional Film)    

The orientation film liquid (manufactured by Nissan Chemical Industry Co., Ltd .: RN2880) was spin-coated on a glass substrate, pre-fired with a hot plate at 80 ° C for 3 minutes, and fired in an oven at 230 ° C for 30 minutes. Furthermore, this substrate with an orientation film was irradiated with 500 mJ / cm ² (measurement wavelength: 254 nm) of ultraviolet rays by a UV irradiator, and was further calcined in an oven at 230 ° C. for 30 minutes.

To 100 g of the liquid crystal sealant produced in the examples and comparative examples, 1 g of 5 μm glass fiber as a spacer was added and mixed and stirred. The liquid crystal sealant was coated on a glass substrate coated with an alignment film so as to reproduce a corner of 1 cm × 1 cm. The opposite alignment film was coated with a glass substrate and bonded, and irradiated with 3000 mJ by a UV irradiator. After the ultraviolet ray / cm ² , it was put into an oven and heat-cured at 120 ° C. for 1 hour. The peeling adhesion strength of the oriented film-coated glass substrate was measured with a pressure tester (manufactured by Nishijin Co., Ltd .: SS-30WD) by pressing the corners. The intensity is shown in Table 2.

    (PCT followed by intensity light directing film)    

A liquid crystal sealant was coated on the alignment film-coated substrate, and a PCT test (condition: temperature 121 ° C., humidity 100%, air pressure 2 atm, test time 12 hours) was performed on the cured test piece, and the adhesion strength was measured in the same manner. The intensity is shown in Table 2.

    [Measurement of glass transition temperature]    

The liquid crystal sealants manufactured in the examples and comparative examples were sandwiched between polyethylene terephthalate (PET) films to form a film having a thickness of 100 μm, and the film was irradiated with 3000 mJ / cm ² of ultraviolet light by a UV irradiator. , Put into an oven, and heat-cured at 120 ° C for 1 hour. After curing, the PET film was peeled off to obtain a sealant cured film, which was then cut into a 50 mm x 50 mm short note shape to make a sample piece. This sample piece was measured in a tensile mode of a dynamic viscoelasticity measuring device (DMS-6100: manufactured by SII NanoTechnology) under the conditions of a frequency of 10 Hz and a temperature rise temperature of 3 ° C / min. The loss coefficient Tan δ and The temperature at which the maximum value was obtained in the Tan δ curve was taken as a result of the glass transition temperature. The results are shown in Table 2.

    [Moisture permeability]    

The liquid crystal sealants manufactured in the examples and comparative examples were sandwiched between polyethylene terephthalate (PET) films to form a film having a thickness of 100 μm, and the film was irradiated with 3000 mJ / cm ² of ultraviolet light by a UV irradiator. , Put into an oven, heat-cured at 120 ° C for 1 hour, peeled the PET film after curing, and made a sample. The moisture permeability of the sample at 60 ° C and 90% was measured with a moisture permeability measuring machine (manufactured by Lessy: L80-5000). The results are shown in Table 2.

    [Voltage holding rate]    

An orientation film liquid (NRB, manufactured by Nissan Chemical Co., Ltd.) was coated on a substrate with a transparent electrode, and calcined, and UV orientation treatment was performed. The substrate is dispensed so that the line width of the obtained liquid crystal sealant is 0.6 mm after bonding, and the liquid crystal (JC-5015LA; manufactured by JNC Co., Ltd.) is then divided into a main seal and a dummy seal. Fine droplets of liquid within the sealed pattern frame. Then, the in-plane spacers (Naotco Spacer KSEB-525F manufactured by Naotco Co., Ltd .; the gap width after bonding was 5 μm) were spread on another substrate subjected to friction treatment, and the bonding was performed in a vacuum using a bonding device. The substrate where the liquid crystal has been dropped. After opening the atmosphere to form a gap, only the inside of the sealed pattern frame was shielded, and 100 mJ / cm ² of ultraviolet rays were irradiated with a UV irradiator, and then placed in an oven and cured at 120 ° C. for 1 hour to prepare a liquid crystal test unit for evaluation.

Table 2 shows the results of the voltage retention ratios measured under the conditions of 5 V, 1 Hz, and 60 ° C. for the liquid crystal physical property evaluation system (manufactured by Toyo Technica Co., Ltd .: Model 6254) for the evaluation liquid crystal test unit.

A-1: 4-hydroxybenzoic acid

A-2: thiosalicylic acid

A-3: Terephthalic acid

A-4: 2,6-dihydroxyisonicotinic acid (citrazinic acid)

A-5: 4-aminobenzoic acid

A-6: 4- (aminomethyl) benzoic acid

A-7: 2-mercaptonicotinic acid

B-1: Bisphenol A acrylic epoxy ester

(Synthesis by a general synthesis method, for example, Japanese Patent Laid-Open No. 2016-24243)

B-2: Bisphenol A partially acrylic epoxy ester

(Synthesized by a general synthetic method, for example, in Japanese Patent Application Laid-Open No. 2016-24243, with 50% equivalent reaction)

B-3: EB3702

(Made by Daicel-Allnex Co., Ltd.)

B-4: EB3708

(Made by Daicel-Allnex Co., Ltd.)

B-5: Bisphenol A epoxy resin

(RE310S: manufactured by Nippon Kayaku)

B-6: Bisphenol S epoxy resin

(RE203: manufactured by Nippon Kayaku)

C-1: Polymethacrylate-based organic fine particles

(Manufactured by Aica Industrial Co., Ltd .: F-351S)

D-1: spherical silica

(Manufactured by Tokuyama Corporation: Sansil SSP-07M)

E-1: 3-glycidoxypropyltrimethoxysilane

(Made by JNC Corporation: Si1a-Ace S-510)

F-1: 2,4-diamino-6- (2'-methylimidazolyl (1 ')) ethyl-mesanthine / Trimeric isocyanate adduct

(Manufactured by Shikoku Chemical Co., Ltd .: 2MAOK-PW)

G-1: OXE04

(Made by BASF company)

H-1: 1,2-bis (trimethylsiloxy) -1,1,2,2-tetraphenylethane

(Pulverized to an average particle size of 1.9 μm)

O-1: Nitroso-based piperidine derivative

(Made by Bo Dong Co., Ltd .: Polystop 7300P)

O-2: Ginseng (2-hydrazinocarbonylethyl) trimeric isocyanate finely pulverized product

O-3: Dihydrazine malonate (manufactured by Otsuka Chemical)

O-4: Ginseng (3-carboxyethyl) trimer isocyanate

(Made by Shikoku Chemical Industry Co., Ltd .: CIC acid, which is finely pulverized by a jet mill to an average particle diameter of 1.5 μm)

From the results in Table 1, it can be seen that in Comparative Example 1 of the conventionally used hydrazine hardening system, the voltage retention rate, glass transition temperature, and bonding strength were all low, and the bonding strength after PCT was as low as half of the initial value. On the other hand, Examples 1 to 9 using the component (A) were confirmed to have excellent adhesion strength, glass transition temperature, moisture permeability, and voltage retention ratio. In particular, both the glass transition temperature and the voltage holding ratio were significantly better than those of Comparative Example 1, and it was confirmed that the component (A) was highly reactive.

From the above, it can be confirmed that the display encapsulant of the present invention using the component (A) has strong bonding strength to an organic film and can achieve high reliability.

    [Industrial availability]    

The sealing agent for a display of the present invention is excellent in handleability, can stably produce a liquid crystal display unit, and also contributes to ensuring long-term reliability of the liquid crystal display unit.

Claims (12)

    A sealing agent for a display, comprising a component (A) and a component (B), the component (A) is a compound having a carboxyl group bonded to an aromatic ring in a molecule, and the component (B) is a hardening compound.         The encapsulant for a display according to item 1 of the scope of patent application, wherein the component (A) is a compound having a carboxyl group, a hydroxyl group, and a hydrogenthio group.         The encapsulant for a display according to item 1 or 2 of the scope of patent application, wherein the component (B) is a component (B-1), and the component (B-1) is a (meth) acrylic compound.         The encapsulant for a display according to any one of claims 1 to 3, wherein the component (B) is a mixture of the component (B-1) and the component (B-2), and the component (B- 1) is a (meth) acrylic compound, and this component (B-2) is an epoxy compound.         The encapsulant for a display according to any one of claims 1 to 4 of the scope of patent application, further comprising a component (C), which is an organic filler.         The encapsulant for a display according to any one of claims 1 to 5 of the patent application scope further contains a component (D), which is an inorganic filler.         The encapsulant for a display according to any one of claims 1 to 6 of the patent application scope further contains a component (E), which is a silane coupling agent.         The encapsulant for a display according to any one of claims 1 to 7 of the scope of patent application, further comprising a component (F), which is a thermosetting catalyst.         The encapsulant for a display according to item 8 of the scope of patent application, wherein the component (F) is an imidazole compound.         The packaging agent for a display according to any one of claims 1 to 9 of the scope of patent application, further comprising a component (G), which is a photoradical polymerization initiator.         The encapsulant for a display according to any one of claims 1 to 10 of the scope of application for a patent, further contains a component (H), which is a thermal radical polymerization initiator.         A liquid crystal display is sealed by a sealing agent for a display according to any one of claims 1 to 11.