TW201903098A - Photocurable composition and adhesive for electronic parts - Google Patents

Abstract

Provided are: a photocurable composition, the molecules of which comprises both an oxium ester structure and a thioxanthone structure; an electronic component adhesive using the same; an electronic component; an LCD cell adhesive; a liquid crystal sealant; and an LCD cell.

Description

Photocurable composition and adhesive for electronic parts

The present invention relates to a photocurable composition, and an adhesive for electronic parts, an electronic part, an adhesive for a liquid crystal display unit, a liquid crystal sealant, and a liquid crystal display unit using the photocurable composition.

The photocurable composition has been widely used in applications such as adhesives for electronic parts such as display sealants, solar cell sealants, and semiconductor sealants. Examples of the display sealant include a sealant for a liquid crystal display, a sealant for an organic electroluminescence (EL) display, and an adhesive for a touch panel. For these display sealants, the following characteristics are required: while having excellent hardenability, the outgassing is small without causing damage to the display element.

However, since the photocurable composition does not undergo a curing reaction in a portion that cannot be reached by light, there is a limit to the portion that can be used.

In particular, in a liquid crystal sealant for a liquid crystal dropping method (hereinafter also simply referred to as a "liquid crystal sealant"), a light-shielding portion is generated due to a line portion of an array substrate of a liquid crystal display element and a black matrix portion of a color filter substrate. This light-shielding portion prevents light from reaching the liquid crystal sealant, and causes a problem of poor display near the sealing portion. If the primary hardening is not sufficiently performed by light due to the presence of the light-shielding portion, a large amount of unhardened components remain in the liquid crystal sealant. When proceeding to the secondary hardening step by heat in this state, the unhardened component is promoted to dissolve in the liquid crystal due to heat, causing display defects near the sealed portion.

In order to solve the problem to be solved, various studies are being conducted to improve the thermal reactivity of the liquid crystal sealant. In other words, there is an attempt to suppress the liquid crystal contamination by rapidly reacting a liquid crystal sealant that has not been sufficiently hardened by light at a low temperature in a light-shielding portion. For example, Patent Documents 1 and 2 disclose a method using a thermal radical polymerization initiator. In addition, Patent Documents 3 to 5 disclose a method using a polycarboxylic acid as a hardening accelerator.

However, in order for a thermal radical polymerization initiator to efficiently generate radicals, a thermal radical polymerization initiator having a molecular weight as small as a certain degree must be used. However, low-molecular compounds are easily soluble in liquid crystals, and although reactive Excellent, but the liquid crystal contamination caused by the thermal radical polymerization initiator itself becomes a problem. In addition, when a polycarboxylic acid is used, there is a possibility that the moisture resistance reliability may be impaired, and although it varies depending on the application, it may not be used in some cases.

As described above, although a liquid crystal sealant has been actively developed, a liquid crystal sealant has not been realized so far, which has excellent light-shielding part hardening properties on one side and low liquid crystal contamination on the other. [Prior Art 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 No. 2007/138870 Patent Document 4: Japanese Patent Laid-Open No. 2008-15155 Patent Document 5 : Japanese Patent Application Publication No. 2009-139922

[Problems to be Solved by the Invention] 的 An object of the present invention is to provide a photocurable composition that can be cured by irradiating light such as ultraviolet rays or visible light, and has a high sensitivity to light and can be used even with low-energy light. Fully hardened. [Technical means to solve the problem]

After intensive research, the inventors found that the following facts have completed the present invention described in the following [1] to [15]: a compound having both an oxime ester structure and a thioxanthone structure in the molecule, It is excellent as a dehydrogenated photoinitiator and a decomposed initiator, and has sufficient hardenability even when irradiated with low-energy light. In addition, in the present specification, "(meth) acrylic acid" means "acrylic and / or methacrylic acid", and "(meth) acrylate" means "acrylate and / or methacrylic acid" "Acrylic ester" and "(meth) acrylfluorenyl" mean "acrylfluorenyl and / or methacrylfluorenyl".

[1] A photocurable composition containing a compound having both an oxime ester structure and a thioxanthone structure in a molecule. [2] The photocurable composition according to [1], which contains a curable compound. [3] The photocurable composition according to [2], wherein the curable compound is a (meth) acrylic compound. [4] The photocurable composition according to [2], wherein the curable compound is a mixture of a (meth) acrylic compound and an epoxy compound. [5] The photocurable composition according to any one of [1] to [4], which contains an organic filler. [6] The photocurable composition according to [5], wherein the organic filler is selected from the group consisting of amine ester fine particles, acrylic fine particles, styrene fine particles, styrene olefin fine particles, and silica fine particles. At least one selected. [7] The photocurable composition according to any one of [1] to [6], which contains an inorganic filler. [8] The photocurable composition according to any one of [1] to [7], which contains a silane coupling agent. [9] The photocurable composition according to any one of [1] to [8], which contains a thermosetting agent. [10] The photocurable composition according to [9], wherein the thermosetting agent is an organic hydrazine compound. [11] An adhesive for electronic parts, using the photocurable composition according to any one of [1] to [10]. [12] An electronic component adhered with a hardened material obtained by hardening the electronic component adhesive according to [11]. [13] An adhesive for a liquid crystal display unit using the photocurable composition according to any one of [1] to [10]. [14] A liquid crystal sealant using the photocurable composition according to any one of [1] to [10]. [15] A liquid crystal display unit, which is adhered using the liquid crystal display unit adhesive according to [13] or the liquid crystal sealant according to [14]. [efficacy]

The photocurable composition of the present invention has high curability in a portion where light cannot reach sufficiently, and has sufficient curability even when irradiated with low-energy light in consideration of damage to other members, and is therefore useful for As a kind of sealant for electronic parts or an adhesive for electronic parts, it is used for manufacturing electronic parts having a light-shielding part and electronic parts which must be hardened by visible light, and is particularly useful as a sealant for displays.

<Photocurable composition> [A compound having both an oxime ester structure and a thioxanthone structure in the molecule] The photocurable composition of this embodiment contains a compound having both an oxime ester structure and a thioxanthone structure in the molecule (hereinafter (Also known as a "specific compound"). This specific compound functions as a photopolymerization initiator, and its sensitivity to low-energy light is very high. A specific compound may be used individually by 1 type, and may use 2 or more types together.

The oxime ester structure which a specific compound has is a structure represented by following formula (1), for example.

In the formula (1), R ₁ represents a (C1-C8) alkyl group or (C1-C8) alkoxy group, R ₂ represents a hydrogen atom, (C1-C8) alkyl group, (C2-C8) alkenyl group, Aryl, or heteroaryl.

In the formula (1), the (C1-C8) alkyl group in R ₁ may be, for example, a linear, branched, or cyclic unsubstituted alkyl group, and a linear alkyl group. Better. Specific examples include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl; isopropyl and isobutyl Branched alkyl groups such as alkyl, secondary butyl, and tertiary butyl; cyclic alkyl groups such as cyclopropyl, cyclopentyl, and cyclohexyl. The (C1-C8) alkyl group may be formed by bonding a linear alkyl group such as 3-cyclopentylpropyl to a cyclic alkyl group. Among these, (C1-C3) alkyl is preferred from the viewpoint of compatibility with the hardening compound and the solvent. Specific examples include methyl, ethyl, n-propyl, and methyl. Better.

In the above formula (1), as the (C1-C8) alkoxy group in R ₁ , for example, a linear or branched unsubstituted alkoxy group, and a linear alkoxy group is good. Specific examples include linear alkoxy groups such as methoxy, ethoxy, n-propoxy, and n-butoxy; isopropoxy, isobutoxy, secondary butoxy, Branched alkoxy groups such as tertiary butoxy. Of these, methoxy is preferred.

In the formula (1), R ₁ is preferably a methyl group.

In the formula (1), the (C1-C8) alkyl group in R ₂ includes the same meaning as the (C1-C8) alkyl group in R ₁ described above, including those preferred.

Examples of the (C2-C8) alkenyl group in R ₂ in the formula (1) include a linear or branched unsubstituted alkenyl group. Specific examples include vinyl, 1-propenyl, 2-propenyl, and the like.

Examples of the aryl group and heteroaryl group in R ₂ in the formula (1) include a phenyl group, a pyridyl group, and a thienyl group. Aryl and heteroaryl groups can be substituted by at least one of carboxyl, sulfo, hydroxyl, acetamido, halogen atom, cyano, nitro, sulfamoyl, alkyl, alkoxy, etc To replace. Examples of the aryl group and heteroaryl group having such a substituent include a 4-nitrophenyl group.

In the above formula (1), R ₂ is preferably a hydrogen atom or a methyl group.

In the above formula (1), * represents a bonding position, and may be a position bonded to a thioxanthone structure represented by the following formula (2), and when the thioxanthone structure is bonded via another bonding group , Can be the position of bonding with the bonding base. Examples of the bonding group include an alkylene group, an alkylene group, and an alkylene oxide group.

The thioxanthone structure possessed by the specific compound is a structure represented by the following formula (2).

In the above formula (2), * represents a bonding position, and may be a position to be bonded to the oxime ester structure represented by the above formula (1), and when it is bonded to the oxime ester structure via another bonding group, it may be The position of the bond with the bond base. Examples of the bonding group include an alkylene group, an alkylene group, and an alkylene oxide group.

The thioxanthone structure represented by the formula (2) may have other substituents in addition to the oxime ester structure represented by the formula (1). As other substituents, for example, a carboxyl group, a sulfo group, a hydroxyl group, an acetamido group, a halogen atom, a cyano group, a nitro group, a sulfamoyl group, a (C1-C8) alkyl group, a (C1-C8) alkoxy group Base etc.

When the thioxanthone structure represented by the formula (2) has another substituent, the substituent may be bonded to R ₁ in the formula (1) to form a cyclic structure.

Specific examples of the specific compound include compounds of the following compound numbers 1 to 20. However, it is not limited to these. Among the compounds of compound numbers 1 to 20, compounds of compound numbers 1 to 17 and 20 are preferred, and compounds of compound number 1 are preferred.

Among the specific compounds, for example, the compounds of Compound No. 1 and Compound No. 20 can be synthesized by a method described in Synthesis Example 1 described later.

The specific compound generates radicals by irradiating light such as ultraviolet rays or visible light, and has a high sensitivity to light, and thus exhibits sufficient reactivity even with low-energy light. In addition, it has good thermal stability, low volatility, good storage stability, and good solubility, and is also suitable for photopolymerization in the presence of air (oxygen). Therefore, the specific compound is useful as a photopolymerization initiator for polymerizing a curable compound capable of radical polymerization.

The content of the specific compound in the total amount of the photocurable composition is usually 0.001 to 10% by mass, preferably 0.002 to 5.0% by mass, and more preferably 0.1 to 3.0% by mass. When the content of the specific compound is 0.001% by mass or more, there is a tendency that the photocurable composition can sufficiently undergo photopolymerization. On the other hand, if the content of the specific compound is 10% by mass or less, unreacted compounds can be reduced. As a result, it is possible to suppress the deterioration of the light resistance and storage stability of the photocurable composition, and to adversely affect the display characteristics when the photocurable composition is used as a sealant for a display element.

[Photopolymerization Initiator] 的 The photocurable composition of the present embodiment may contain other photopolymerization initiators in addition to the specific compounds described above. The other photopolymerization initiator is not particularly limited as long as it is a compound capable of generating radicals, acids, bases, and the like by irradiating ultraviolet rays or visible light to start a chain polymerization reaction.

Specific examples of other photopolymerization initiators include benzophenone dimethyl ketal, 1-hydroxycyclohexylphenyl ketone, diethylthioxanthone, benzophenone, and 2-ethylanthracene. Quinone, 2-hydroxy-2-methylphenylacetone, 2-methyl [4- (methylthio) phenyl] -2- (N-morpholinyl) -1-propane, 2,4,6-tri Methylbenzylidene diphenylphosphine oxide, camphorquinone, 9-fluorenone, diphenyl disulfide and the like. Examples of commercially available products include: IRGACURE ^RTM 651, 184, 2959, 127, 907, 396, 379EG, 819, 784, 754, 500, OXE01, OXE02, DAROCURE ^RTM 1173, LUCIRIN ^RTM TPO (the above are manufactured by BASF Corporation) ); SEIKUOL ^RTM Z, BZ, BEE, BIP, BBI (the above are made by Seiko Chemical Co., Ltd.) and so on. Furthermore, the superscript "RTM" in this specification means a registered trademark.

Among these, from the viewpoint of improving the hardenability of the photocurable composition by using light absorption in a wide range of wavelengths, the absorbance at the maximum absorption wavelength (λmax) in the wavelength region of 200 to 300 nm is preferably A photopolymerization initiator having a photopolymerization initiator of 400 or more, a photopolymerization initiator having a maximum absorption wavelength (λmax) in a wavelength region of 200 to 300 nm and an absorbance of 500 or more, and more preferably a wavelength of 200 to 300 nm A photopolymerization initiator having a maximum absorption wavelength (λmax) in a region having an absorbance of 1500 or more. Examples of the photopolymerization initiator having an absorbance at a maximum absorption wavelength (λmax) in a wavelength region of 200 to 300 nm of 500 or more include, for example, IRGACURE ^RTM 651, 184, and 2959 (trade names). Further, as a photopolymerization initiator having an absorbance at a maximum absorption wavelength (λmax) in a wavelength region of 200 to 300 nm of 1500 or more, for example, IRGACURE ^RTM 2959 (trade name) can be mentioned.

From the viewpoint of preventing outgassing, the photopolymerization initiator preferably has a molecular weight of 150 to 1,000. Similarly, from the viewpoint of preventing outgassing, the photopolymerization initiator preferably has a (meth) acrylfluorenyl group in the molecule, and for example, 2-methacryloxyethyl isocyanate and Reaction product of 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one. This compound can be produced by the method described in International Publication No. 2006/027982.

When the photocurable composition of this embodiment contains other photopolymerization initiators, the content of the other photopolymerization initiators in the total amount of the photocurable composition is preferably 0.001 to 10% by mass, and more preferably 0.1 to 5.0% by mass is preferred.

[Photo-starting Aid] The photo-curable composition of this embodiment may contain a photo-starting aid such as a tertiary amine in order to further improve the hardenability. The tertiary amines are not particularly limited, and examples thereof include ethyl p-dimethylaminobenzoate, iso-amyl p-dimethylaminobenzoate, and N, N-dimethylbenzylamine. In addition, a high-molecular-weight compound can also be appropriately used, which is obtained by branching a plurality of tertiary amines with a polyhydric alcohol or the like in one molecule.

When the photocurable composition of this embodiment contains a photoinitiator, the content of the photostarter in the total amount of the photocurable composition is preferably 0.005 to 20% by mass, and 0.01 to 10% by mass. % Is better.

[Sclerosing Compound] 的 The photocurable composition of the present embodiment preferably contains a sclerosing compound. The curable compound is not particularly limited as long as it is a compound that can be cured by light, heat, or the like, and is preferably a (meth) acrylic acid compound such as a (meth) acrylate compound or an epoxy (meth) acrylate compound. Department of compounds. The (meth) acrylic compound may be used individually by 1 type, and may use 2 or more types together.

Examples of the (meth) acrylic acid ester compound include N-acryloxyethylhexahydrophthalimide, acrylamidomorpholine, 2-hydroxypropyl (meth) acrylate, and (meth) acrylate. Group) 4-hydroxybutyl acrylate, cyclohexane-1,4-dimethanol mono (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, phenyl Polyethoxy (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, o-phenylphenol monoethoxy (meth) acrylate, o-phenylphenol polyethoxylate (Meth) acrylate, p-pentylphenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, tribromophenoxyethyl (meth) acrylate, bicyclic (meth) acrylate Amyl ester, 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 polyethoxydi (meth) acrylate, bis Phenol A polypropoxy di (meth) acrylate, bisphenol F polyethoxy di ( (Meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, ginseng ((meth) acryloxyethyl) isocyanurate, pentaerythritol tetra (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, trimethylol Propane tri (meth) acrylate, trimethylolpropane (poly) ethoxytri (meth) acrylate, bis (trimethylolpropane) tetra (meth) acrylate, neopentyl glycol and Diacrylates of esters of hydroxytrimethylacetate, diacrylates of ε-caprolactone adducts of esters of neopentyl glycol and hydroxytrimethylacetate, and the like. Among these, preferred are N-acryloxyethylhexahydrophthalimide, phenoxyethyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate.

The epoxy (meth) acrylate compound is obtained by a conventional method by reacting an epoxy compound with (meth) acrylic acid. The epoxy compound used as the raw material is not particularly limited, and an epoxy compound having two or more functions is preferred. Examples of the bifunctional or more epoxy compound include resorcinol diglycidyl ether, bisphenol A type epoxy compound, bisphenol F type epoxy compound, bisphenol S type epoxy compound, and phenol novolac Type epoxy compound, cresol novolac type epoxy compound, bisphenol A novolac type epoxy compound, bisphenol F novolac type epoxy compound, alicyclic epoxy compound, aliphatic chain epoxy compound, shrinkage Glyceride type epoxy compound, glycidylamine type epoxy compound, hydantoin type epoxy compound, isocyanurate type epoxy compound, phenol novolac type epoxy compound with triphenol methane skeleton, difunctional Diglycidyl etherates of phenols (catechol, resorcinol, etc.), diglycidyl etherification of difunctional alcohols, halides or hydrides thereof, and the like. Among these, when the photocurable composition of this embodiment is used as a liquid crystal sealant, from the viewpoint of liquid crystal contamination, a bisphenol A type epoxy compound and resorcinol diglycidyl are preferred. Based ether. The ratio of the epoxy group to the (meth) acrylfluorenyl group in the epoxy (meth) acrylate compound is not particularly limited, and can be appropriately selected from the viewpoint of process suitability.

The photocurable composition of the present embodiment preferably contains an epoxy compound in addition to the (meth) acrylic compound (however, the (meth) acrylic compound is excluded). An epoxy compound may be used individually by 1 type, and may use 2 or more types together.

The epoxy compound is not particularly limited, and an epoxy compound having two or more functions is preferred. Examples of the bifunctional or higher epoxy compound include resorcinol diglycidyl ether, bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and phenol novolac. Epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol F novolac epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, shrinkage Glyceride type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, isocyanurate type epoxy resin, phenol novolac type epoxy resin with triphenol methane skeleton, difunctional Diglycidyl etherates of phenols (catechol, resorcinol, etc.), diglycidyl etherification of difunctional alcohols, halides or hydrides thereof, and the like. Among these, when the photocurable composition of this embodiment is used as a liquid crystal sealant, from the viewpoint of liquid crystal contamination, bisphenol A type epoxy resin and resorcinol diglycidyl ether are used. Better.

When the photocurable composition of this embodiment contains a curable compound, the content of the curable compound in the total amount of the photocurable composition is usually 10 to 80% by mass, and preferably 20 to 70% by mass. When the photocurable composition of the present embodiment contains an epoxy compound, the content of the epoxy compound in the total amount of the photocurable composition is usually 5 to 50% by mass, preferably 5 to 30% by mass. .

[Organic Filler] The photocurable composition of this embodiment may contain an organic filler. The organic filler may be used singly or in combination of two or more kinds.

Examples of the organic filler include amine ester fine particles, acrylic fine particles, styrene fine particles, styrene olefin fine particles, and silica fine particles. As the silica fine particles, KMP-594, KMP-597, and KMP-598 (trade names, which are manufactured by Shin-Etsu Chemical Industry Co., Ltd.); TORAYFIL ^RTM E-5500, 9701, EP-2001 (trade names, The above is made by Dow Corning Toray Co., Ltd.). As the amine ester fine particles, JB-800T and HB-800BK (trade names, the above are manufactured by Gensang Industrial Co., Ltd.) are preferred. As the styrene fine particles, RABALON ^RTM T320C, T331C, SJ4400, SJ5400, SJ6400, SJ4300C, SJ5300C, and SJ6300C (trade names, which are manufactured by Mitsubishi Chemical Corporation) are preferred. As the styrene olefin fine particles, SEPTON ^RTM SEPS2004 and SEPS2063 (trade names, which are manufactured by KURARAY Co., Ltd.) are preferable. These organic fillers may be organic fillers having a core-sheath structure using two or more materials.

Among these organic fillers, acrylic fine particles and silica fine particles are preferred.

The acrylic fine particles are preferably acrylic rubbers having a core-sheath structure composed of two types of acrylic rubbers, and more preferably acrylic fine particles having a core layer of n-butyl acrylate and a sheath layer of methyl methacrylate. Acrylic microparticles having a core layer of n-butyl acrylate and a sheath layer of methyl methacrylate have been marketed by AICA Industrial Co., Ltd. as ZEFIAC ^RTM F-351 (trade name).

In addition, as the silica fine particles, there can be mentioned, for example, an organopolysiloxane crosslinked powder, a linear dimethylpolysiloxane crosslinked powder, and a silicone resin (for example, polysilsesquioxane). Resin) is a composite silicone rubber formed by covering the surface of silicone rubber. Among these siloxane fine particles, a siloxane rubber having a linear dimethylpolysiloxane crosslinked powder or a linear dimethylpolysiloxane crosslinked with a silicone resin is preferable. Powdered compound silicone microparticles. The shape of the rubber powder should be spherical, and its viscosity after addition is less thickened.

When the photocurable composition of this embodiment contains an organic filler, the content of the organic filler in the total amount of the photocurable composition is usually 5 to 50% by mass, and preferably 5 to 40% by mass.

[Inorganic Filler] The photocurable composition of this embodiment may contain an inorganic filler. The inorganic filler may be used singly or in combination of two or more kinds.

Examples of the inorganic filler include silicon oxide, silicon carbide, silicon nitride, boron nitride, calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, aluminum oxide, magnesium oxide, zirconia, and hydrogen. Alumina, magnesium hydroxide, calcium silicate, aluminum silicate, lithium aluminum silicate, zirconium silicate, barium titanate, glass fiber, carbon fiber, molybdenum disulfide, asbestos, etc .; preferred examples include fused silica, Crystalline silicon oxide, silicon nitride, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, mica, talc, clay, alumina, aluminum hydroxide, calcium silicate, aluminum silicate, etc. Particles such as aluminum and talc are preferred.

The average particle diameter of the inorganic filler is more preferably 2000 nm or less, preferably 1000 nm or less, and more preferably 300 nm or less. When the average particle diameter of the inorganic filler is set to 2000 nm or less, for example, when the photocurable composition of the present embodiment is used as a liquid crystal sealing agent for a liquid crystal dropping method, a liquid crystal cell having a narrow gap is produced. When the upper and lower glass substrates are bonded, a gap can be formed smoothly. In addition, a preferable lower limit is about 10 nm, and a more preferable lower limit is about 100 nm. The particle diameter can be measured using a laser diffraction scattering type particle size distribution measuring device (dry type) (manufactured by SEISHIN Corporation, LMS-30).

When the photocurable composition of this embodiment contains an inorganic filler, the content of the inorganic filler in the total amount of the photocurable composition is usually 5 to 50% by mass, and preferably 5 to 40% by mass. When the content of the inorganic filler is 5% by mass or more, the adhesive strength to the glass substrate can be improved, and the moisture resistance reliability can also be improved. Therefore, there is a tendency that the decrease in the adhesive strength after moisture absorption can be suppressed. When the content of the inorganic filler is 50% by mass or less, for example, when the photocurable composition of this embodiment is used as a liquid crystal sealing agent for a liquid crystal dropping method to produce a liquid crystal cell, the inorganic filler tends to be crushed. And it went smoothly.

[Silane coupling agent] 的 The photocurable composition of this embodiment may contain a silane coupling agent in order to improve the adhesive strength and moisture resistance. The silane coupling agent may be used singly or in combination of two or more kinds.

Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropylmethyldiethyl. Oxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3 -Aminopropylmethyldimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- Mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methyl Acrylic methoxypropyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, etc. These silane coupling agents are commercially available from Shin-Etsu Chemical Industry Co., Ltd., such as KBM series and KBE series, so they can be easily obtained from the market.

When the photocurable composition of this embodiment contains a silane coupling agent, the content of the silane coupling agent in the total amount of the photocurable composition is preferably from 0.05 to 3% by mass.

[Thermal hardener] The photocurable composition of the present embodiment may contain a thermal hardener. A thermosetting agent may be used individually by 1 type, and may use 2 or more types together.

Thermal hardeners undergo nucleophilic reactions by lone pairs of electrons or anions in the molecule. Examples include polyamines, polyphenols, and organic hydrazine compounds. Among these, an organic hydrazine compound is preferably used.

Among the organic hydrazine compounds, examples of the aromatic hydrazine compound include terephthalylhydrazine, m-xylylenedihydrazine, 2,6-naphthoate dihydrazine, 2,6-pyridinedihydrazine, 1,2,4-benzenetrimethylhydrazine, 1,4,5,8-naphthoic acid tetramethylhydrazine, pyromethylenetetramethylhydrazine, etc. In addition, among the organic hydrazine compounds, the aliphatic hydrazine compounds may be, for example, formamidine, acetazine, propidium, hydrazine, malonazine, succinimide, glutarazine, hexamethylene Dihydrazine, heptanehydrazine, decanediozine, 1,4-cyclohexanedihydrazine, tartrazinehydrazine, apple dihydrazine, iminodiethylhydrazine, N, N'-hexa N, N'-hexamethylenebis (semicarbazide), lemon trimethylhydrazine, trimethylhydrazine nitrogen acetate, cyclohexanetrimethylhydrazine; 1,3-bis (hydrazinocarbonylethyl) -5-isopropylhydantoin (1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin) and the like have a hydantoin skeleton, preferably a hydantoin valinate skeleton (hydantoin ring Diisohydrazine compounds having a skeleton in which a carbon atom is substituted with an isopropyl group; reference (1-hydrazinocarbonylmethyl) isocyanurate, reference (2-hydrazinocarbonylethyl) isocyanurate, reference (1-hydrazinocarbonylethyl) isocyanurate, ginseng (3-hydrazinocarbonylpropyl) isocyanurate, bis (2-hydrazinocarbonylethyl) isocyanurate, and the like.

Among the organic hydrazine compounds, from the viewpoint of the balance between the hardening reactivity and the potential, m-xylylenedihydrazine, malondihydrazine, hexamethylenedihydrazine, and ginseng (1-hydrazinocarbonylmethyl) are preferred. Isocyanurate, ginseng (1-hydrazinocarbonylethyl) isocyanurate, ginseng (2-hydrazinocarbonylethyl) isocyanurate, and ginseng (3-hydrazinocarbonylpropyl) isocyanate The cyanurate is more preferably ginseng (2-hydrazinocarbonylethyl) isocyanurate.

When the photocurable composition of this embodiment contains a thermosetting agent, the content of the thermosetting agent in the total amount of the photocurable composition is usually 0.1 to 10% by mass, preferably 1 to 5% by mass.

[Thermal Radical Polymerization Initiator] 的 The photocurable composition of the present embodiment may contain a thermal radical polymerization initiator in order to improve the curing speed and curability. A thermal radical polymerization initiator may be used individually by 1 type, and may use 2 or more types together.

The thermal radical polymerization initiator is not particularly limited as long as it is a compound capable of generating a radical by heating to initiate a chain polymerization reaction, and examples thereof include organic peroxides, azo compounds, benzoin compounds, Benzoyl ether compounds, acetophenone compounds, benzopinacol and the like are preferably used.

Examples of commercially available organic peroxides include: 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 (trade names, the above are manufactured by Akzo Co., Ltd.); PERMEK ^RTM N, H, S, F, D, G, PERHEXA ^RTM H, HC, TMH, C, V, 22, MC, PERCURE ^RTM AH, PERBUTYL ^RTM H, C, ND, L, PERCUMYL ^RTM H, D, PEROYL ^RTM IB, IPP, PEROCTA ^RTM ND (commercial names, the above is made by Nippon Oil Co., Ltd.) and so on.

Examples of commercially available azo compounds include VA-044, 086, V-070, VPE-0201, and VSP-1001 (trade names, which are manufactured by Wako Pure Chemical Industries, Ltd.).

When the photocurable composition of this embodiment contains a thermal radical polymerization initiator, the thermal radical polymerization initiator is usually 0.0001 to 10% by mass, and 0.0005 to 5% by mass of the total amount of the photocurable composition. % Is preferable, and 0.001 to 3% by mass is more preferable.

[Other Components] 的 The photocurable composition of the present embodiment may contain additives such as a hardening accelerator, a radical polymerization inhibitor, a pigment, an antifoaming agent, and a solvent as needed.

(Hardening Accelerator) Examples of the hardening accelerator include organic acids and imidazole compounds. As the organic acid, for example, organic carboxylic acid, organic phosphoric acid, etc. are preferred, and organic carboxylic acid is preferred. Specifically, for example: phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, benzophenonetetracarboxylic acid, furandicarboxylic acid, succinic acid, adipic acid, dodecanedicarboxylic acid Acid, sebacic acid, thiodipropionic acid, cyclohexanedicarboxylic acid, ginseng (2-carboxymethyl) isocyanurate, ginseng (2-carboxyethyl) isocyanurate, ginseng (2-carboxy Propyl) isocyanurate, bis (2-carboxyethyl) isocyanurate, and the like. Examples of the imidazole compound include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, and 1-benzene Methyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl 2-undecylimidazole, 2,4-diamino-6- (2'-methylimidazole (1 ')) ethyl-s-triazine, 2,4-diamino-6- ( 2'-undecylimidazole (1 ')) ethyl-s-triazine, 2,4-diamino-6- (2'-ethyl-4-methylimidazole (1')) ethyl -s-triazine, 2,4-diamino-6- (2'-methylimidazole (1 ')) ethyl-s-triazine isocyanuric acid adduct, 2-methylimidazole isocyanide 2: 3 adduct of uric acid, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-5 -Methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole, and the like.

When the photocurable composition of this embodiment contains a hardening accelerator, the content of the hardening accelerator in the total amount of the photocurable composition is usually 0.1 to 10% by mass, and preferably 1 to 5% by mass.

(Radical Polymerization Inhibitor) As a radical polymerization inhibitor, as long as it is a compound capable of reacting with a radical generated from a photo radical polymerization initiator, a thermal radical polymerization initiator, or the like to inhibit the progress of polymerization, It is not particularly limited, and examples thereof include radical polymerization inhibitors such as quinone-based, piperidine-based, hindered phenol-based, and nitroso-based. Specifically, for example, naphthoquinone, 2-hydroxynaphthoquinone, 2-methylnaphthoquinone, 2-methoxynaphthoquinone, 2,2,6,6-tetramethylpiperidine-1-oxide ( 2,2,6,6-tetramethylpiperidine-1-oxyl), 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, butylated hydroxyanisole, 2,6-bis (tertiarybutyl) -4-ethylphenol, 2,6-bis (tertiarybutyl) cresol, β- (3,5-bis (tertiarybutyl) -4-hydroxyphenyl) stearate, 2,2'-methylenebis (4-ethyl-6-tertiarybutylphenol) , 4,4'-thiobis (3-methyl-6-tert-butylphenol), 4,4'-butylenebis (3-methyl-6-tert-butylphenol), 3,9 -Bis [1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propanyloxy] ethyl] 2,4,8,10 -Tetraoxaspiro [5.5] undecane, [methylene-3- (3 ', 5'-bis (tertiarybutyl) -4'-hydroxyphenyl) propionate] methane, 1, 3,5-gins (3 ', 5'-bis (tertiary-butyl-4'-hydroxybenzyl) -secondary-triazine-2,4,6- (1H, 3H, 5H) trione) P-methoxyl Aluminum salt of phenol, 4-methoxy-1-naphthol, thiodiphenylamine, N-nitrosophenylhydroxylamine; trade names ADEKA STAB LA-81, trade names ADEKA STAB LA-82 (all are ADEKA Co., Ltd.), etc. Among these, naphthoquinone-based, hydroquinone-based, nitroso-based, and piperidine-based radical polymerization inhibitors are preferred, and naphthoquinone, 2-hydroxynaphthoquinone, and hydroquinone 2,6-bis (tertiary butyl) p-cresol, POLYSTOP 7300P (made by Bodong Co., Ltd.) is preferred, and POLYSTOP 7300P (made by Bodong Co., Ltd.) is more preferred.

When the photocurable composition of this embodiment contains a radical polymerization inhibitor, the content of the radical polymerization inhibitor in the total amount of the photocurable composition is usually 0.0001 to 1% by mass, and 0.001 to 0.5% by mass Preferably, it is 0.01 to 0.2% by mass.

[Viscosity of Photocurable Composition] The viscosity of the photocurable composition of this embodiment at 25 ° C is preferably 150 to 500 Pa · s, and more preferably 200 to 500 Pa · s. In particular, when the photocurable composition of this embodiment is used as a liquid crystal sealant, the viscosity of the photocurable composition at 25 ° C is preferably 250 to 400 Pa · s, and more preferably 280 to 320 Pa · s. good. When the viscosity is 250 Pa · s or more, there is a tendency that it is possible to suppress the occurrence of liquid crystal infiltration and to facilitate unitization. When the viscosity is 400 Pa · s or less, the liquid crystal sealant tends to be easily applied.

[Method for preparing photocurable composition] As an example of the method for preparing the photocurable composition of the present embodiment, the following method can be mentioned. First, the specific compound is heated to dissolve the curable compound. Then, after cooling to room temperature, an organic filler, an inorganic filler, a silane coupling agent, a thermosetting agent, a thermal radical polymerization initiator, an antifoaming agent, a leveling agent, a solvent, etc. are added as needed. Then, by using a conventional mixing device such as a three-roll mill, a sand mill, and a ball mill, the mixture is uniformly mixed and filtered with a metal sieve, whereby the photohardenable composition of this embodiment can be prepared.

<Applications, etc. of Photocurable Composition> 组成 The photocurable composition of this embodiment is very useful as a sealant for electronic parts or an adhesive for electronic parts. Examples of sealants or adhesives for electronic parts include adhesives for flexible printed wiring boards, adhesives for tape and tape automatic bonding (TAB), adhesives for semiconductors, and adhesives for various displays. , But not limited to these.

The photocurable composition of the present embodiment is very useful as an adhesive for a liquid crystal display unit, and is particularly useful as a liquid crystal sealant. An example of a liquid crystal display unit when the photocurable composition of this embodiment is used as a liquid crystal sealant is shown below.

A liquid crystal display unit manufactured by using an adhesive for a liquid crystal display unit is formed by forming a predetermined electrode on a pair of substrates, and arranging the pair of substrates facing each other at a predetermined interval, and sealing the periphery with a liquid crystal sealant. The liquid crystal is sealed in the gap. The type of the enclosed liquid crystal is not particularly limited. The substrate is composed of the following combined substrates: glass, quartz, plastic, silicon oxide, and the like, and at least one of the substrates is transparent.

The manufacturing method of a liquid crystal display cell is as follows, for example. First, a spacer (gap control material) is added to the liquid crystal sealant. Examples of the spacer include glass fiber, silica beads, and polymer beads. The diameter of the spacer varies depending on the purpose, but is usually 2 to 8 μm, and preferably 4 to 7 μm. The used amount of the spacer is usually 0.1 to 4 parts by mass, preferably 0.5 to 2 parts by mass, and more preferably 0.9 to 1.5 parts by mass with respect to 100 parts by mass of the liquid crystal sealant.

Then, a liquid crystal sealant is applied to one of a pair of substrates using a dispenser, a screen printing device, or the like, and then temporarily cured at 80 to 120 ° C. if necessary. Then, the liquid crystal is dropped on the inside of the bank 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 can be obtained by curing it at 90 to 130 ° C for 1 to 2 hours. In addition, when used in the form of a combination of light and heat, the liquid crystal sealant is irradiated with ultraviolet rays using an ultraviolet ray irradiator to perform light curing. The amount of ultraviolet irradiation is preferably 500 to 6000 mJ / cm ² , and more preferably 1000 to 4000 mJ / cm ² . Then, it is hardened at 90-130 degreeC for 1 to 2 hours as needed, and a liquid crystal display cell is obtained by this. The liquid crystal display unit obtained in the above manner does not cause display defects due to liquid crystal contamination, and has excellent adhesion and humidity resistance reliability.

The photocurable composition according to this embodiment is very suitable for applications such as an electronic component having a light-shielding portion, or an adhesive application that must be hardened with low-energy light such as visible light. For example, it is suitable as a sealing agent for liquid crystal displays, a sealing agent for organic EL, and an adhesive agent for touch panels used under a line light-shielding part. [Example]

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to the examples. In addition, as long as there is no special record, "%" in this text is a quality standard.

<Synthesis Example 1> [Synthesis of 2-Ethylthioxanthone]

2-Ethylthioxanthone was synthesized according to the synthetic sequence described in the previous literature (Material Technology, Vol. 27, No. 6 (2009), pp. 242-251).

[Synthesis of TX-OXE (Compound No. 1)]

A thermometer and a cooling tube were set in a 200 mL four-neck reaction vessel, and a nitrogen gas flow was started at a flow rate of 30 mL / min. In a reaction vessel, 2-acetamidothioxanthone (0.50 g), hydroxylamine hydrochloride (0.20 g), and N, N-dimethylformamide (60 mL) were added, and the reaction was performed at 80 ° C. 4 hours. After 50 mL of water was added and the reaction was stopped, extraction was performed with methyl isobutyl ketone (200 mL), and water washing was performed 3 times with 50 mL of water. The solvent was removed using an evaporator to obtain the oxime of 2-acetamidothioxanthone (TX-OX / yellow solid). The yellow solid (crude crystals) obtained here was directly used for the oxime esterification reaction.

A thermometer and a cooling tube were set in a 200 mL four-neck reaction vessel, and a nitrogen gas flow was started at a flow rate of 30 mL / min. The total amount of TX-OX, acetic anhydride (0.24 g), and butyl acetate (30 mL) were added to the reaction vessel, and the reaction was performed at 90 ° C for 5 hours. After 50 mL of water was added and the reaction was stopped, extraction was performed with methyl isobutyl ketone (200 mL), and water washing was performed 3 times with 50 mL of water. The solvent was removed using an evaporator to obtain a yellow solid. The yellow solid obtained here was recrystallized with acetone and water, and 0.35 g of 2-oximethioxanthone oxime ester body (TX-OXE / yellow solid) was obtained (yield of 2-stage reaction: 57%) .

[Synthesis of TX-OXE-2 (Compound No. 20)]

A thermometer and a cooling tube were set in a 200 mL four-neck reaction vessel, and a nitrogen gas flow was started at a flow rate of 30 mL / min. TX-OX (0.5 g), benzamidine chloride (0.52 g), triethylamine (0.47 g), and tetrahydrofuran (30 mL) were added to the reaction vessel, and the reaction was performed at 55 ° C for 8 hours. After adding 30 mL of water to stop the reaction, the precipitated solid was separated by filtration. The yellow solid obtained here was recrystallized with dimethyl sulfene and water to obtain 0.28 g of the oxime ester of 2-ethylfluorenylthioxanthone (TX-OXE-2 / yellow solid) (yield: 40 %).

<Examples 1 and 2> (i) The hardening compounds (B-1, B-2, and B-3) shown in Table 1 below were mixed and heated at 90 ° C to make the specific compounds (A- 1) After dissolving, cool to room temperature. Then, the remaining components in Table 1 below were added and stirred, and then dispersed using a three-roll mill. Then, the photocurable composition of Examples 1 and 2 was prepared by filtering with a metal sieve (635 sieve). In addition, the numerical value of each component in Table 1 shows a mass part.

<Comparative Examples 1 and 2> Preparation and comparison were performed in the same manner as in Examples 1 and 2 except that the specific compound (A-1) was replaced with other components (O-2, O-3) shown in Table 1 below. The photocurable composition of Examples 1 and 2.

<Evaluation> [Light-shielding part hardening degree (ultraviolet irradiation)] To each of the photocurable compositions of Examples 1 and 2, and Comparative Examples 1 and 2 was added 1% by mass of 4 μm glass fiber (Nippon Electric Glass Co., Ltd. (Manufactured), and the liquid crystal sealant is prepared. After the glass substrate was etched with chromium to set a line and a pitch of 100 μm, a liquid crystal sealant was applied to the glass substrate, and a black matrix substrate was bonded as an opposing substrate. Then, from the side of the substrate on which the wires / pitches are provided, ultraviolet rays having a wavelength of 365 nm were irradiated with an irradiation amount of 3000 mJ / cm ² (100 mW / cm ² for 30 seconds), and the degree of hardening was measured with a microscope. The results are shown in Table 1 below.

[Hardness of the light-shielding portion (visible light irradiation)] To each of the photocurable compositions of Examples 1 and 2 and Comparative Examples 1 and 2 was added 1% by mass of 4 μm glass fiber (manufactured by Nippon Electric Glass Co., Ltd.), A liquid crystal sealant is prepared. After the glass substrate was etched with chromium to set a line and a pitch of 100 μm, a liquid crystal sealant was applied to the glass substrate, and a black matrix substrate was bonded as an opposing substrate. Then, visible light with a wavelength of 405 nm was irradiated with an irradiation amount of 3000 mJ / cm ² (100 mW / cm ² , 30 seconds) from the side of the substrate on which the wires / spaces were provided, and the degree of hardening was measured with a microscope. The results are shown in Table 1 below.

[Viscosity] Use an E-type viscometer (R115-type viscometer (manufactured by Toki Sangyo Co., Ltd.)) to measure the viscosity at 25 ° C of each photocurable composition of Examples 1 and 2, and Comparative Examples 1 and 2 Pa · s). The results are shown in Table 1 below.

[Table 1] A-1: TX-OXE (synthesized in Synthesis Example 1) B-1: bisphenol A epoxy acrylate (synthesized by the method described in Japanese Patent Application Laid-Open No. 2016-24243) B-2: intermediate Epoxy acrylate of hydroquinone glycidyl ether (synthesized by the method described in WO2004 / 104683) B-3: Partial epoxy acrylate of bisphenol A type (Japanese Patent Laid-Open No. 2016-50% equivalent) Acrylic acid reacts in No. 24243) C-1: Polymethacrylate organic fine particles (manufactured by AICA Industrial Co., Ltd .: F-351S) D-1: spherical silica (manufactured by TOKUYAMA Co., Ltd .: SANSIL SSP- 07M) E-1: 3-Glycidoxypropyltrimethoxysilane (JNC Corporation: Sila-Ace S-510) F-1: Sebacic acid hydrazine (Otsuka Chemical Co., Ltd .: SDH) O-1: 1,3,5-ginseng (2-carboxyethyl) isocyanurate (manufactured by Shikoku Chemical Co., Ltd., CIC acid) O-2: diethylthioxanthone O-3: 1, 2 -Octanedione, 1- [4- (phenylthio)-, 2- (O-benzylideneoxime)] (OXE-01, manufactured by BASF)

As shown in Table 1, TX-OXE was used as the photocurable composition of Examples 1 and 2 as the specific compound, compared to the photocurable composition of Comparative Examples 1 and 2 using compounds having similar structures, regardless of It is irradiated with ultraviolet rays or visible light, and it has better hardenability in the deep part (low-energy irradiation part). In other words, it was confirmed that the photocurable compositions of Examples 1 and 2 have excellent curability with low energy.

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Claims (15)

A photocurable composition containing a compound having both an oxime ester structure and a thioxanthone structure in a molecule. The photocurable composition according to claim 1, which contains a curable compound. The photocurable composition according to claim 2, wherein the curable compound is a (meth) acrylic compound. The photocurable composition according to claim 2, wherein the curable compound is a mixture of a (meth) acrylic compound and an epoxy compound. The photocurable composition according to any one of claims 1 to 4, which contains an organic filler. The photocurable composition according to claim 5, wherein the organic filler is at least one selected from the group consisting of amine ester fine particles, acrylic fine particles, styrene fine particles, styrene olefin fine particles, and silica fine particles. 1 species. The photocurable composition according to any one of claims 1 to 4, which contains an inorganic filler. The photocurable composition according to any one of claims 1 to 4, which contains a silane coupling agent. The photocurable composition according to any one of claims 1 to 4, which contains a thermosetting agent. The photocurable composition according to claim 9, wherein the thermosetting agent is an organic hydrazine compound. An adhesive for electronic parts using the photocurable composition according to any one of claims 1 to 10. An electronic component is adhered with a hardened material obtained by hardening the electronic component adhesive according to claim 11. An adhesive for liquid crystal display units using the photocurable composition according to any one of claims 1 to 10. A liquid crystal sealant using the photocurable composition according to any one of claims 1 to 10. A liquid crystal display unit is adhered using the liquid crystal display unit according to claim 13 with an adhesive or the liquid crystal sealant according to claim 14.