Curable resin composition, coating layer, and film

Abstract

One purpose of the present invention is to provide a curable resin composition able to yield a cured product having excellent hardness and adhesive properties even if exposed to a high temperature high humidity environment. Another purpose of the present invention is to provide a coating layer and a film that are formed using said curable resin composition. The present invention is a curable resin composition which contains a curable resin, a coupling agent and a polymerization initiator. The curable resin includes a curable resin having two or more glycidyl groups per molecule. The coupling agent includes a coupling agent having one glycidyl group per molecule. Relative to a total of 100 parts by mass of the curable resin as a whole and the coupling agent as a whole, the content of the coupling agent having one glycidyl group per molecule is 10-50 parts by mass.

Description

Curable resin composition, coating layer, and film

[0001] The present invention relates to a curable resin composition. The present invention also relates to a coating layer and a film formed using the curable resin composition.

[0002] Optical semiconductor elements such as LEDs have low power consumption and long life, and are therefore widely used in backlights of liquid crystal displays, lighting fixtures, etc. Optical semiconductor elements deteriorate when exposed to moisture or gas in the atmosphere, resulting in a decrease in light extraction efficiency. Therefore, they are typically sealed with a sealant and protected with a cover glass or the like before use. In recent years, forming a coating layer on the surface of an optical semiconductor element using a hard coating agent has been considered as a method for protecting and sealing an optical semiconductor element without using a cover glass or the like (e.g., Patent Document 1, etc.).

[0003] Japanese Patent Application Laid-Open No. 2016-1657

[0004] Hard coating agents that protect and seal optical semiconductor elements are required to achieve both hardness and adhesion (especially adhesion to glass) after curing. However, even if conventional hard coating agents have excellent hardness and adhesion after curing, it has been difficult to maintain these hardness and adhesion when exposed to a high-temperature, high-humidity environment. The present invention aims to provide a curable resin composition that can produce a cured product that has excellent hardness and adhesion even when exposed to a high-temperature, high-humidity environment. Another aim of the present invention is to provide a coating layer and a film formed using the curable resin composition.

[0005] Disclosure 1 is a curable resin composition containing a curable resin, a coupling agent, and a polymerization initiator, wherein the curable resin includes a curable resin having two or more glycidyl groups per molecule, and the coupling agent includes a coupling agent having one glycidyl group per molecule, and the content of the coupling agent having one glycidyl group per molecule is 10 parts by mass or more and 50 parts by mass or less relative to a total of 100 parts by mass of the entire curable resin and the entire coupling agent. Disclosure 2 is a curable resin composition of Disclosure 1, wherein the polymerization initiator includes a photopolymerization initiator. Disclosure 3 is a curable resin composition of Disclosure 1, wherein the curable resin composition is irradiated with UV-LED at a wavelength of 365 nm and an illuminance of 100 mW / cm. ２ The curable resin composition of Disclosure 1 or 2 is a curable resin composition of Disclosure 1 or 2, which is obtained by irradiating the curable resin composition with ultraviolet light of 365 nm wavelength and 100 mW / cm irradiance for 30 seconds, followed by heating at 100°C for 30 minutes, and then subjecting the cured product to a reliability test in which the product is exposed to an environment of 85°C and 85% RH for 24 hours, after which the pencil hardness measured in accordance with JIS K 5600-5-4 is 4H or more. ２ The curable resin composition of Disclosure 1, 2, or 3 is a curable resin composition obtained by irradiating a cured product with ultraviolet light of 100°C for 30 seconds and then heating at 100°C for 30 minutes, and then subjecting the cured product to a reliability test in which the cured product is exposed to an environment of 85°C and 85% RH for 24 hours. The curable resin composition is classified as 0 or 1 in an adhesion test using a cross-cut method in accordance with JIS K 5600-5-6. Disclosure 5 is a coating layer formed using the curable resin composition of Disclosure 1, 2, 3, or 4. Disclosure 6 is a film formed using the curable resin composition of Disclosure 1, 2, 3, or 4. The present invention is described in detail below.

[0006] The present inventors have investigated the use of a curable resin composition in combination with a curable resin having two or more glycidyl groups per molecule and a coupling agent having one glycidyl group per molecule, and have investigated the content of the coupling agent having one glycidyl group per molecule within a specific range. As a result, they have found that a curable resin composition can be obtained that can give a cured product that has excellent hardness and adhesion (particularly adhesion to glass) even when exposed to a high-temperature, high-humidity environment, and have completed the present invention.

[0007] The curable resin composition of the present invention contains a curable resin. The curable resin includes a curable resin having two or more glycidyl groups per molecule (hereinafter also referred to as "the curable resin of the present invention"). By using the curable resin of the present invention in combination with a coupling agent having one glycidyl group per molecule in an amount described below, the curable resin composition of the present invention can give a cured product that is excellent in hardness and adhesiveness (particularly adhesiveness to glass) even when exposed to a high-temperature, high-humidity environment.

[0008] The curable resin according to the present invention has two or more glycidyl groups in one molecule. From the viewpoints of reactivity and the hardness of the resulting cured product, the curable resin according to the present invention more preferably has four or more glycidyl groups in one molecule. There is no particular upper limit to the number of glycidyl groups in one molecule of the curable resin according to the present invention, but the substantial upper limit is eight.

[0009] Specific examples of the curable resin according to the present invention include dicyclopentadiene dimethanol diglycidyl ether, trimethylolpropane triglycidyl ether, ethylene oxide-added trimethylolpropane triglycidyl ether, propylene oxide-added trimethylolpropane triglycidyl ether, caprolactone-modified trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, propylene oxide-added glycerin triglycidyl ether, pentaerythritol triglycidyl ether, ditrimethylolpropane tetraglycidyl ether, pentaerythritol tetraglycidyl ether, dipentaerythritol pentaglycidyl ether, and dipentaerythritol hexaglycidyl ether.

[0010] The curable resins may be used alone or in combination of two or more.

[0011] The preferred lower limit of the content of the curable resin according to the present invention relative to 100 parts by mass of the total of the curable resin and the coupling agent is 50 parts by mass. When the content of the curable resin according to the present invention is 50 parts by mass or more, the cured product of the obtained curable resin composition will have better hardness and adhesion (particularly adhesion to glass) when exposed to a high-temperature, high-humidity environment. Furthermore, the preferred lower limit of the content of the curable resin according to the present invention in the total curable resin is 50% by mass, and more preferably 90% by mass. The content of the curable resin according to the present invention in the total curable resin may be 100% by mass, i.e., the curable resin may consist solely of the curable resin according to the present invention.

[0012] The preferred lower limit of the total content of the curable resins in 100 parts by mass of the curable resin composition of the present invention is 40 parts by mass, and the preferred upper limit is 90 parts by mass. When the total content of the curable resins is within this range, the resulting curable resin composition has better curability and adhesiveness. The more preferred lower limit of the total content of the curable resins is 45 parts by mass, and the more preferred upper limit is 85 parts by mass.

[0013] The curable resin composition of the present invention contains a coupling agent. The coupling agent includes a coupling agent having one glycidyl group per molecule (hereinafter also referred to as "the coupling agent of the present invention"). In this specification, "having one glycidyl group per molecule" means having only one glycidyl group per molecule, and coupling agents having two or more glycidyl groups per molecule are not considered to be coupling agents of the present invention.

[0014] The coupling agent according to the present invention is preferably a silane coupling agent having one glycidyl group in one molecule.

[0015] Specific examples of the silane coupling agent having one glycidyl group per molecule include 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane.

[0016] The above coupling agents may be used alone or in combination of two or more.

[0017] The lower limit of the content of the coupling agent according to the present invention is 10 parts by mass, and the upper limit is 50 parts by mass, relative to 100 parts by mass of the total of the curable resin and the coupling agent. When the content of the coupling agent according to the present invention is 10 parts by mass or more, the cured product of the obtained curable resin composition exhibits excellent adhesion when exposed to a high-temperature, high-humidity environment. When the content of the coupling agent according to the present invention is 50 parts by mass or less, the cured product of the obtained curable resin composition exhibits excellent hardness when exposed to a high-temperature, high-humidity environment. The preferred lower limit of the content of the coupling agent according to the present invention is 20 parts by mass, the preferred upper limit is 40 parts by mass, and the more preferred upper limit is 30 parts by mass. Furthermore, the preferred lower limit of the content of the coupling agent according to the present invention in the total coupling agent is 10% by mass, and the more preferred lower limit is 30% by mass. The content of the coupling agent according to the present invention in the total coupling agent may be 100% by mass, i.e., the coupling agent may consist solely of the coupling agent according to the present invention.

[0018] The curable resin composition of the present invention contains a polymerization initiator. The polymerization initiator preferably includes a photopolymerization initiator. The photopolymerization initiator preferably includes a photocationic polymerization initiator. The photocationic polymerization initiator is not particularly limited as long as it generates a protonic acid or a Lewis acid upon light irradiation, and may be an ionic photoacid-generating type or a nonionic photoacid-generating type.

[0019] The anion moiety of the ionic photoacid generating cationic photopolymerization initiator may be, for example, BF ４ － , P.F. ６ － , SbF ６ － , (BX ４ ) －(wherein X represents a phenyl group substituted with at least two fluorine atoms or trifluoromethyl groups). Examples of the anion moiety include PF ｍ (C ｎ F ２ｎ＋１ ) ６－ｍ － (wherein, m is an integer of 0 or more and 5 or less, and n is an integer of 1 or more and 6 or less). Examples of the ionic photoacid-generating photocationic polymerization initiator include aromatic sulfonium salts, aromatic iodonium salts, aromatic diazonium salts, aromatic ammonium salts, and (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe salts, which have the anion moiety.

[0020] Examples of the aromatic sulfonium salt include bis(4-(diphenylsulfonio)phenyl)sulfide bishexafluorophosphate, bis(4-(diphenylsulfonio)phenyl)sulfide bishexafluoroantimonate, bis(4-(diphenylsulfonio)phenyl)sulfide bistetrafluoroborate, bis(4-(diphenylsulfonio)phenyl)sulfide tetrakis(pentafluorophenyl)borate, diphenyl-4-(phenylthio)phenylsulfonium hexafluorophosphate, diphenyl-4-(phenylthio)phenylsulfonium tris(pentafluoroethyl)trifluorophosphate, diphenyl-4-(phenylthio)phenylsulfonium hexafluoroantimonate, diphenyl-4-(phenylthio)phenylsulfonium tetrafluoroborate, and diphenyl-4-(phenylthio)phenylsulfonium tetrakis(pentafluorophenyl)borate. , triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis(pentafluorophenyl)borate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bishexafluorophosphate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bishexafluoroantimonate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide bistetrafluoroborate, bis(4-(di(4-(2-hydroxyethoxy))phenylsulfonio)phenyl)sulfide tetrakis(pentafluorophenyl)borate, tris(4-(4-acetylphenyl)thiophenyl)sulfonium tetrakis(pentafluorophenyl)borate, and the like. Of these, triarylsulfonium tetrakis(pentafluorophenyl)borate such as triphenylsulfonium tetrakis(pentafluorophenyl)borate is preferred.

[0021] Examples of the aromatic iodonium salts include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis(pentafluorophenyl)borate, bis(dodecylphenyl)iodonium hexafluorophosphate, bis(dodecylphenyl)iodonium hexafluoroantimonate, bis(dodecylphenyl)iodonium tetrafluoroborate, bis(dodecylphenyl)iodonium tetrakis(pentafluorophenyl)borate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexafluorophosphate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexafluoroantimonate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium tetrafluoroborate, and 4-methylphenyl-4-(1-methylethyl)phenyliodonium tetrakis(pentafluorophenyl)borate.

[0022] Examples of the aromatic diazonium salt include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis(pentafluorophenyl)borate.

[0023] Examples of the aromatic ammonium salt include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl-2-cyanopyridinium tetrakis(pentafluorophenyl)borate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluorophosphate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluoroantimonate, 1-(naphthylmethyl)-2-cyanopyridinium tetrafluoroborate, and 1-(naphthylmethyl)-2-cyanopyridinium tetrakis(pentafluorophenyl)borate.

[0024] Examples of the (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe salt include (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe(II) hexafluorophosphate, (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe(II) hexafluoroantimonate, (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe(II) tetrafluoroborate, and (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-Fe(II) tetrakis(pentafluorophenyl)borate.

[0025] Examples of the nonionic photoacid generating cationic photopolymerization initiator include nitrobenzyl esters, sulfonic acid derivatives, phosphate esters, phenolsulfonic acid esters, diazonaphthoquinone, and N-hydroxyimide sulfonates.

[0026] Among the above-mentioned cationic photopolymerization initiators, commercially available ones include, for example, cationic photopolymerization initiators manufactured by Midori Chemical Industry Co., Ltd., cationic photopolymerization initiators manufactured by Union Carbide Corporation, cationic photopolymerization initiators manufactured by ADEKA Corporation, cationic photopolymerization initiators manufactured by 3M Corporation, cationic photopolymerization initiators manufactured by BASF Corporation, cationic photopolymerization initiators manufactured by Solvay SA, and cationic photopolymerization initiators manufactured by San-Apro Corporation. Examples of the cationic photopolymerization initiators manufactured by Midori Chemical Industry Co., Ltd. include DTS-200. Examples of the cationic photopolymerization initiators manufactured by Union Carbide Corporation include UVI6990 and UVI6974. Examples of the cationic photopolymerization initiators manufactured by ADEKA Corporation include SP-150 and SP-170. Examples of the cationic photopolymerization initiators manufactured by 3M Corporation include FC-508 and FC-512. Examples of the cationic photopolymerization initiator manufactured by BASF include IRGACURE 261 and IRGACURE 290. Examples of the cationic photopolymerization initiator manufactured by Solvay include PI 2074. Examples of the cationic photopolymerization initiator manufactured by San-Apro include CPI-100P, CPI-200K, and CPI-210S.

[0027] The polymerization initiators may be used alone or in combination of two or more.

[0028] The content of the polymerization initiator is preferably 1 part by mass at the lower limit and 20 parts by mass at the upper limit relative to 100 parts by mass of the curable resin. When the content of the polymerization initiator is within this range, the resulting curable resin composition has better curability and storage stability. The content of the polymerization initiator is more preferably 3 parts by mass at the lower limit and 15 parts by mass at the upper limit.

[0029] From the viewpoint of light resistance, the curable resin composition of the present invention may further contain an ultraviolet absorber.

[0030] Examples of the ultraviolet absorber include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-ethoxy-2'-ethyloxalic acid bisanilide, dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, 2-(2'-hydroxy-4'-n-octoxyphenyl)benzotriazole, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, phenyl salicylate, p-t-butylphenyl salicylate, and 2-ethylhexyl 2-cyano-3,3-diphenylacrylate.

[0031] The content of the ultraviolet absorber is preferably 0.001 parts by mass at the lower limit and 5 parts by mass at the upper limit relative to 100 parts by mass of the curable resin. When the content of the ultraviolet absorber is within this range, the resulting curable resin composition has better light resistance. The more preferred lower limit of the content of the ultraviolet absorber is 0.1 parts by mass, and the more preferred upper limit is 1 part by mass.

[0032] The curable resin composition of the present invention may further contain a leveling agent from the viewpoint of flatness of the coating film.

[0033] Examples of the leveling agent include silicone-based leveling agents, fluorine-based leveling agents, and acrylic-based leveling agents.

[0034] The content of the leveling agent is preferably 0.01 parts by mass at the lower limit and 10 parts by mass at the upper limit relative to 100 parts by mass of the curable resin. By using the leveling agent in this range, the resulting curable resin composition has better coatability and coating film flatness. The more preferred lower limit of the content of the leveling agent is 0.03 parts by mass, and the more preferred upper limit is 1 part by mass.

[0035] From the viewpoint of coatability, the curable resin composition of the present invention may further contain a thixotropy-imparting agent.

[0036] Examples of the thixotropy-imparting agent include polysiloxane, polyacrylic, polyamide, polyvinyl alcohol, polyether ester, alkyl-modified cellulose, peptide, polypeptide, and silica.

[0037] The content of the thixotropy-imparting agent is preferably 0.1 parts by mass or less and 5 parts by mass or less relative to 100 parts by mass of the curable resin. When the content of the thixotropy-imparting agent is within this range, the resulting curable resin composition has better coatability. The content of the thixotropy-imparting agent is more preferably 1 part by mass or less and 3 parts by mass or less.

[0038] The curable resin composition of the present invention has excellent low outgassing properties and does not require a solvent removal step, and therefore the solvent content is preferably 1% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less, and it is particularly preferable that the curable resin composition does not contain a solvent.

[0039] Furthermore, the curable resin composition of the present invention may contain various known additives such as dyes, curing retarders, reinforcing agents, viscosity modifiers, and antioxidants, as needed.

[0040] The curable resin composition of the present invention has a viscosity, measured at 25°C using an E-type viscometer, of preferably 10 mPa·s as the lower limit and 50,000 mPa·s as the upper limit. Having the viscosity within this range ensures that the resulting curable resin composition has excellent coatability. A more preferred lower limit of the viscosity is 20 mPa·s and a more preferred upper limit of 10,000 mPa·s. The viscosity can be measured, for example, using a VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) E-type viscometer with a No. 1 rotor at a rotational speed of 1 rpm or 10 rpm.

[0041] The curable resin composition of the present invention is irradiated with a UV-LED at a wavelength of 365 nm and an illuminance of 100 mW / cm ２ The cured product obtained by irradiating the cured resin composition with ultraviolet light for 30 seconds and then heating at 100°C for 30 minutes preferably has a pencil hardness of 4H or more as measured in accordance with JIS K 5600-5-4 (hereinafter also simply referred to as "pencil hardness of the cured product"). Since the pencil hardness of the cured product is 4H or more, the curable resin composition of the present invention can be suitably used as a hard coating agent for protecting and sealing optical semiconductor elements and the like. The pencil hardness of the cured product is more preferably 7H or more. Furthermore, the curable resin composition of the present invention can be cured by irradiating the cured resin composition with ultraviolet light for 30 seconds and heating at 100°C for 30 minutes. The pencil hardness of the cured product is preferably 4H or more as measured in accordance with JIS K 5600-5-4. Since the pencil hardness of the cured product is 4H or more, the cured resin composition of the present invention can be suitably used as a hard coating agent for protecting and sealing optical semiconductor elements and the like. The pencil hardness of the cured product is more preferably 7H or more. Furthermore, the curable resin composition of the present invention can be cured by irradiating the cured resin composition with ultraviolet light using a UV-LED at a wavelength of 365 nm and an illuminance of 100 mW / cm. ２ The cured product obtained by irradiating the cured product with ultraviolet light for 30 seconds and then heating at 100°C for 30 minutes is preferably subjected to a reliability test in which the product is exposed to an environment of 85°C and 85% RH for 24 hours. After the reliability test, the cured product preferably has a pencil hardness of 4H or more as measured in accordance with JIS K 5600-5-4 (hereinafter also referred to as "pencil hardness of the cured product after the reliability test"). Since the cured product after the reliability test has a pencil hardness of 4H or more, the curable resin composition of the present invention can be suitably used as a hard coating agent for protective encapsulation of optical semiconductor elements and the like, even when exposed to a high-temperature, high-humidity environment. The pencil hardness of the cured product after the reliability test is more preferably 7H or more. Pencils with hardnesses ranging from 6B to 10H are used as pencils for measuring pencil hardness. In this specification, a pencil hardness of "nH or more (n is an integer)" means that the pencil hardness is equal to or harder than the pencil hardness of nH.

[0042] From the viewpoint of reliability when the curable resin composition of the present invention is used as a hard coating agent for protective encapsulation of an optical semiconductor element or the like, the difference between the pencil hardness of the cured product and the pencil hardness of the cured product after the reliability test is preferably 2 levels or less, more preferably 1 level or less, and most preferably 0 level, i.e., the pencil hardness of the cured product and the pencil hardness of the cured product after the reliability test are the same.

[0043] The curable resin composition of the present invention is irradiated with a UV-LED at a wavelength of 365 nm and an illuminance of 100 mW / cm ２ The cured product obtained by irradiating the composition with ultraviolet light of 100 nm for 30 seconds and then heating at 100°C for 30 minutes preferably has a classification of 0 or 1 in an adhesion test using the cross-cut method in accordance with JIS K 5600-5-6 (hereinafter simply referred to as "adhesion classification of the cured product"). When the adhesion classification of the cured product is 0 or 1, the curable resin composition of the present invention can be suitably used as a hard coating agent for protecting and sealing optical semiconductor elements and the like. It is most preferable that the adhesion classification of the cured product is 0. Furthermore, the curable resin composition of the present invention can be cured by irradiating the composition with ultraviolet light of 100 nm for 30 seconds and then heating at 100°C for 30 minutes. When the adhesion classification of the cured product is 0 or 1, the cured product can be suitably used as a hard coating agent for protecting and sealing optical semiconductor elements and the like. It is most preferable that the adhesion classification of the cured product is 0. Furthermore, the curable resin composition of the present invention can be cured by irradiating the composition with ultraviolet light of 100 nm for 30 seconds and heating at 100°C for 30 minutes. ２ The cured product obtained by irradiating the composition with ultraviolet light for 30 seconds and then heating at 100°C for 30 minutes is preferably subjected to a reliability test in which the cured product is exposed to an environment of 85°C and 85% RH for 24 hours, and then the resulting cured product is classified as 0 or 1 in an adhesion test using the cross-cut method in accordance with JIS K 5600-5-6 (hereinafter also referred to as the "adhesion classification of the cured product after the reliability test"). Since the cured product after the reliability test has an adhesion classification of 0 or 1, the curable resin composition of the present invention can be suitably used as a hard coating agent for protective encapsulation of optical semiconductor elements and the like, even when exposed to a high-temperature, high-humidity environment. It is most preferable that the adhesion classification of the cured product after the reliability test is 0.

[0044] The curable resin composition of the present invention can be used for hard coating agents, sealants for displays, microlenses, etc. In particular, it is suitably used as a hard coating agent to form a coating layer on an optical semiconductor element or the like, or as a film to cover an optical semiconductor element or the like, thereby protecting and sealing the optical semiconductor element or the like. A coating layer formed using the curable resin composition of the present invention also constitutes one aspect of the present invention. A film formed using the curable resin composition of the present invention also constitutes one aspect of the present invention.

[0045] The coating layer of the present invention can be formed by applying the curable resin composition of the present invention to an object to be coated, such as an optical semiconductor element, and then curing the composition. The film of the present invention can be formed by applying the curable resin composition of the present invention to a release film or the like, and then curing the composition.

[0046] Examples of methods for applying the curable resin composition of the present invention include spin coating, bar coating, and inkjet methods.

[0047] When the curable resin composition of the present invention contains the photopolymerization initiator as the polymerization initiator, the curable resin composition of the present invention can be easily cured by light irradiation. The method for curing the curable resin composition of the present invention by light irradiation includes, for example, a method using a wavelength of 300 nm or more and 400 nm or less and a light irradiation rate of 300 mJ / cm. ２ More than 3000mJ / cm ２ Examples of the method include irradiating light with the following integrated light amount.

[0048] Examples of light sources for irradiating the curable resin composition of the present invention with light include UV-LEDs, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, excimer lasers, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, sodium lamps, halogen lamps, xenon lamps, fluorescent lamps, sunlight, and electron beam irradiation devices. These light sources may be used alone or in combination of two or more. These light sources are appropriately selected according to the absorption wavelength of the photopolymerization initiator.

[0049] Examples of means for irradiating the curable resin composition of the present invention with light include simultaneous irradiation from various light sources, sequential irradiation with a time lag, and a combination of simultaneous irradiation and sequential irradiation, and any of these irradiation means may be used.

[0050] The curable resin composition of the present invention may be cured by heating after the above-mentioned light irradiation.

[0051] According to the present invention, it is possible to provide a curable resin composition that can give a cured product that is excellent in hardness and adhesion even when exposed to a high-temperature, high-humidity environment. Furthermore, according to the present invention, it is possible to provide a coating layer and a film formed using the curable resin composition.

[0052] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0053] (Examples 1 to 8 and Comparative Examples 1 to 6) Each of the curable resin compositions of Examples 1 to 8 and Comparative Examples 1 to 6 was prepared by stirring and mixing each material using a stirring mixer according to the blending ratios shown in Table 1. Awatori Rentaro ARE-310 (manufactured by Thinky Corporation) was used as the stirring mixer.

[0054] <Evaluation> The following evaluations were carried out on each of the obtained curable resin compositions. The results are shown in Table 1.

[0055] (Hardness and hardness retention of cured product) Each of the obtained curable resin compositions was applied to a glass substrate having a length of 5 cm, a width of 5 cm, and a thickness of 0.7 mm using a spin coater at 900 rpm for 20 seconds to obtain a coating film having a thickness of 10 μm. Then, a UV-LED was used to apply the coating film at a wavelength of 365 nm and an illuminance of 100 mW / cm. ２The curable resin composition was cured by irradiating it with ultraviolet light for 30 seconds, and then heating it at 100°C for 30 minutes to obtain a test piece. The pencil hardness of the obtained test piece was measured in accordance with JIS K 5600-5-4 under a load of 750g, and the hardness of the cured product was evaluated according to the following criteria. Pencils with hardnesses ranging from 6B to 10H were used. In addition, the obtained test piece was subjected to a reliability test in which it was exposed to an environment of 85°C and 85% RH for 24 hours, and then the pencil hardness was measured in the same manner, and the hardness of the cured product after the reliability test was evaluated. AA: When the pencil hardness was 7H or more A: When the pencil hardness was 4H or more and 6H or less B: When the pencil hardness was 3H or less Note that, in this specification, a pencil hardness of "nH or less (n is an integer)" means that the pencil hardness is a hardness that corresponds to nH, or is softer than a hardness that corresponds to nH. Furthermore, the hardness retention was evaluated based on the difference between the pencil hardness of the cured product (the pencil hardness of the cured product without the reliability test) and the pencil hardness of the cured product after the reliability test, according to the following criteria: AA: When the pencil hardness of the cured product and the pencil hardness of the cured product after the reliability test were the same (difference was 0 levels); A: When the difference between the pencil hardness of the cured product and the pencil hardness of the cured product after the reliability test was 1 or 2 levels; B: When the difference between the pencil hardness of the cured product and the pencil hardness of the cured product after the reliability test was 3 levels or more.

[0056] (Adhesion to Glass) Each of the obtained curable resin compositions was applied to a glass substrate having a length of 5 cm, a width of 5 cm, and a thickness of 0.7 mm using a spin coater at 900 rpm for 20 seconds to obtain a coating film having a thickness of 10 μm. Then, a UV-LED was used to apply the coating film with a wavelength of 365 nm and an illuminance of 100 mW / cm. ２The curable resin composition was cured by irradiating the composition with ultraviolet light for 30 seconds, followed by heating at 100°C for 30 minutes to obtain a test specimen. The obtained test specimen was subjected to a cross-cut adhesion test in accordance with JIS K 5600-5-6, in which test areas were cut into a grid pattern using a cutter, tape (manufactured by Nichiban Co., Ltd., "Cellotape (registered trademark) No. 405") was applied to the test areas, and the tape was then peeled off. The cut interval was 1 cm, and the tape peel angle was 90°. The test specimen after the adhesion test was visually observed, and the adhesion to glass was evaluated according to the following criteria based on the classification (adhesion classification) in JIS K 5600-5-6. Furthermore, the obtained test specimen was subjected to a reliability test in which it was exposed to an environment of 85°C and 85% RH for 24 hours, and then a cross-cut adhesion test was similarly performed to evaluate the adhesion to glass after the reliability test. AA: If the adhesion classification was 0 or 1 A: If the adhesion classification was 2 or 3 B: If the adhesion classification was 4 or 5

[0057]

[0058] According to the present invention, it is possible to provide a curable resin composition that can give a cured product that is excellent in hardness and adhesion even when exposed to a high-temperature, high-humidity environment. Furthermore, according to the present invention, it is possible to provide a coating layer and a film formed using the curable resin composition.

Claims

1. Contains a curable resin, a coupling agent, and a polymerization initiator; The curable resin includes a curable resin having four or more glycidyl groups in one molecule, The coupling agent includes a coupling agent having one glycidyl group in one molecule, the content of the coupling agent having one glycidyl group in one molecule is 10 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass in total of the entire curable resin and the entire coupling agent, Used to form a coating layer or film A curable resin composition comprising:

2. A curable resin composition comprising a curable resin, a coupling agent, and a polymerization initiator, The curable resin includes a curable resin having two or more glycidyl groups in one molecule, The coupling agent includes a coupling agent having one glycidyl group in one molecule, the content of the coupling agent having one glycidyl group in one molecule is 10 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass in total of the entire curable resin and the entire coupling agent, the curable resin composition is irradiated with ultraviolet light having a wavelength of 365 nm and an illuminance of 100 mW / cm 2 using a UV-LED for 30 seconds, and then heated at 100° C. for 30 minutes to obtain a cured product, which is then subjected to a reliability test in which the product is exposed to an environment of 85° C. and 85% RH for 24 hours, and after that, has a pencil hardness of 4H or more as measured in accordance with JIS K 5600-5-4; The curable resin composition is irradiated with ultraviolet light having a wavelength of 365 nm and an illuminance of 100 mW / cm 2 using a UV-LED for 30 seconds, and then heated at 100°C for 30 minutes to obtain a cured product, which is then subjected to a reliability test in which it is exposed to an environment of 85°C and 85% RH for 24 hours, and then the resultant product is classified as 0 or 1 in an adhesion test using a cross-cut method according to JIS K 5600-5-6. A curable resin composition comprising:

3. The curable resin composition according to claim 1 , wherein the polymerization initiator includes a photopolymerization initiator.

4. A coating layer formed using the curable resin composition according to claim 1 or 2.

5. A film formed using the curable resin composition according to claim 1 or 2.

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