Sol containing silica particles to which epoxy group-containing silicon compound is bonded and method for producing the same

Abstract

The purpose of the present invention is to provide: a sol containing silica particles having an epoxy-group-containing silicon compound bound thereto, in which the occurrence of ring-opening of epoxy groups bound to the silica particles is suppressed and the epoxy groups remain in an epoxy-group form; and a resin composition.　Provided is a silica sol containing silica particles having an epoxy-group-containing silicon compound bound thereto, in which the silica particles are dispersed in an organic solvent and have a pH value of 6 to 8. The epoxy equivalent (B) of the silica sol is 5000 to 25000 (g of silica sol / equivalent), and the epoxy equivalent (A) (g of silica sol / equivalent) of the silica sol which is measured when the silica sol is retained at a pH value of 3 or more and less than 6 is such that the B / A ratio becomes less than 1.0. An Si atom in the epoxy-group-containing silicon compound is bound to the silica particles at a ratio of 0.3 to 5 atoms / nm2 per unit area of the silica particles. The epoxy group is a glycidyl group or a 3,4-epoxycyclohexyl group. Also provided is a composition for forming a cured article, the composition comprising the silica sol and an amine-based curing agent, an acid-anhydride-based curing agent or an acid-generator-based curing agent.

Description

[Technical field]

[0001] The present invention relates to an epoxy group-containing organosilica sol and a cured body-forming composition using the same. [Background technology]

[0002] The organic solvent-dispersed silica sol is combined with an organic resin to obtain a silica-containing resin composition, which can be made into a resin molded body by adding a curing agent, or into a coating composition to be coated on a film. By adding inorganic oxide particles such as silica to the resin, the surface hardness, abrasion resistance, mechanical strength, heat resistance, corrosion resistance, thermal expansion coefficient, bending strength, bending modulus, etc. can be improved. In addition, when the silica particle diameter is 50 nm or less, a cured product can be formed without decreasing transparency.

[0003] Inorganic oxide particles such as silica contained in an organic resin can be further improved in physical properties by reacting with polymerizable groups in the organic resin and being present in the resin matrix via covalent bonds, taking into consideration the compatibility with the organic resin. For this reason, a sol containing silica particles containing polymerizable groups on the silica particles is desired.

[0004] For example, Patent Document 1 discloses a method for producing a composition of a polymerizable organic compound containing silica particles, which comprises mixing an amine-containing organic solvent-dispersed silica sol with a polymerizable organic compound.

[0005] Furthermore, Patent Document 1 discloses that colloidal silica particles are subjected to an organophilic treatment with an organic silane compound, and that the polymerizable organic compound is a liquid epoxy resin.

[0006] Furthermore, Patent Document 2 discloses a liquid epoxy resin composition containing a modified epoxy resin modified with tris-(2,3-epoxypropyl)-isocyanurate and silica particles. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2010 / 058754 [Patent Document 2] International Publication No. 2009 / 008509 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a silica sol which contains, as a dispersoid, silica particles containing an epoxy group or an epoxy group-containing organic group, and an alkoxy group, and which is stably dispersed in an organic solvent as a dispersion medium, and a cured body-forming composition and an epoxy cured body which contain the silica sol.

[0009] In the present invention, the epoxy group forms a diol group by ring-opening under acidic conditions, but when the epoxy group dispersed in a polymerizable resin or a polymerizable solvent is covalently bonded to such functional groups, it is preferable that the epoxy group exists in the form of an epoxy group rather than a diol group. The present invention provides a sol and a resin composition containing silica particles to which an epoxy group-containing silicon compound is bonded, which exists in the form of an epoxy group by suppressing ring-opening of the epoxy group bonded to the silica particles. [Means for solving the problem]

[0010] According to a first aspect of the present invention, there is provided a silica sol comprising silica particles having an epoxy group-containing silicon compound bonded thereto as a dispersoid, the silica particles being dispersed in an organic solvent as a dispersion medium and having a pH of 6 to 8, the silica sol having an epoxy equivalent (B) of 5,000 to 25,000 (g of silica sol / equivalent), and when the silica sol is maintained at a pH of 3 to less than 6, the epoxy equivalent (A) of the silica sol (g of silica sol / equivalent) is such that the ratio B / A is less than 1.0; From the second viewpoint, the silicon atoms of the epoxy group-containing silicon compound are 0.3 to 5 atoms / nm2 per unit area of ​​the silica particle. 2 The silica sol according to the first aspect, As a third aspect, the silica sol according to the first aspect or the second aspect, in which the epoxy group is a glycidyl group or a 3,4-epoxycyclohexyl group. As a fourth aspect, the silica sol according to any one of the first to third aspects, in which the average primary particle diameter of the silica particles measured by a nitrogen gas adsorption method (BET method) is 5 to 100 nm and the average particle diameter of the silica particles measured by a dynamic light scattering method (DLS method) is 5 to 200 nm. As a fifth aspect, the silica sol according to any one of the first to fourth aspects, in which the dispersion medium is an organic substance having a hydroxyl group, an organic substance having a carbonyl structure, or an organic substance having an epoxy group. As a sixth aspect, the silica sol according to the fifth aspect, wherein the organic substance having a hydroxyl group of the dispersion medium is methanol, ethanol, n-propanol, isopropanol, n-butanol, or propylene glycol monomethyl ether. As a seventh aspect, the silica sol according to the fifth aspect, in which the organic substance having a carbonyl structure of the dispersion medium is methyl ethyl ketone, methyl isobutyl ketone, diisopropyl ketone, diisobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, or propylene glycol monomethyl ether acetate. As an eighth aspect, the silica sol according to the fifth aspect, wherein the organic substance having an epoxy group of the dispersion medium is a bisphenol A liquid epoxy compound, a bisphenol F liquid epoxy compound, or 3',4'-epoxycyclohexylmethyl 3',4'-epoxycyclohexane carboxylate; As a ninth aspect, the silica sol according to any one of the first to eighth aspects, which contains a basic substance, and the basic substance is an amine, ammonia, an inorganic alkali compound, or a quaternary ammonium compound. as a tenth aspect, the silica sol according to the ninth aspect, wherein the amine is a secondary amine or a tertiary amine having a total of 5 to 35 carbon atoms; As an eleventh aspect, the silica particles further comprise a compound represented by any one of formulas (1) to (3):

[0011] [ka]

[0012] (In formula (1), R 3 each represents an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, or an organic group having a (meth)acryloyl group, a mercapto group, an amino group, a ureido group, or a cyano group, and is bonded to a silicon atom by a Si-C bond; R 4 each represents an alkoxy group, an acyloxy group, or a halogen group; a represents an integer of 1 to 3; In formula (2) and formula (3), R 5 and R 7 are each an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 30 carbon atoms and bonded to a silicon atom by a Si-C bond, and R 6 and R 8 each represents an alkoxy group, an acyloxy group, or a halogen group, Y represents an alkylene group, an NH group, or an oxygen atom, b is an integer of 1 to 3, c is an integer of 0 or 1, and d is an integer of 1 to 3.) The silica sol according to any one of the first to tenth aspects, which contains a hydrolysate of at least one silane compound selected from the group consisting of: As a twelfth aspect, the present invention provides a silane compound according to the eleventh aspect, which is represented by the above formula (1) (wherein R 3 is an organic group having an aryl group and bonded to a silicon atom by a Si-C bond, 4 each represents an alkoxy group, an acyloxy group, or a halogen group, and a represents an integer of 1 to 3. According to a thirteenth aspect, the silica sol according to any one of the first to twelfth aspects, in which the silica particles of the dispersoid contain aluminum atoms in a ratio of 800 to 10,000 ppm / SiO2 calculated as Al2O3. As a fourteenth aspect, the method comprises the steps (A) to (C) below: Step (A): Silica particles having an average particle size of 5 to 200 nm as determined by dynamic light scattering (DLS) are dissolved in alcohol R 1 OH (but R1 represents an organic group having 1 to 10 carbon atoms which may have an oxygen atom), and the silica sol has a water content of 5 mass % or less; Step (B): A step of adjusting the pH of the silica sol obtained in step (A) to 6 to 8; Step (C): Adding an epoxy group or an epoxy group-containing organic group (R 2 (c) adding a silane compound having a structure such that the silane compound has a structure similar to that of the first aspect, and coating the silica particles with the silane compound; As a fifteenth aspect, further comprising the step (D): Step (D): The dispersion medium of the silica sol obtained in step (C) is changed to alcohol R. 1 a step of substituting OH with an organic substance having a carbonyl structure or an organic substance having an epoxy group; As a sixteenth aspect, the production method according to the fourteenth aspect or the fifteenth aspect, wherein the step (C) further includes a step (C-1) of adding at least one silane compound selected from the group consisting of the formulas (1) to (3) to coat the silica particles. As a seventeenth aspect, the above-mentioned (D) step is a step of dispersing a dispersion medium in alcohol R 1 the production method according to the fifteenth aspect, which is a step (D-1) of replacing OH with an organic substance having a carbonyl structure, and then replacing it with an organic substance having an epoxy group; According to an eighteenth aspect, there is provided a cured body-forming composition comprising the silica sol according to any one of the first to thirteenth aspects, and an amine-based curing agent, an acid anhydride-based curing agent, or an acid generator-based curing agent; and According to a nineteenth aspect, there is provided the cured body-forming composition according to the eighteenth aspect, which further contains an epoxy resin. Effect of the Invention

[0013] The present invention is a silica sol containing silica particles bonded with an epoxy group-containing silicon compound as a dispersoid, the silica particles being dispersed in an organic solvent as a dispersion medium, and having a pH of 6 to 8. The inventors' research has revealed that even in an organic solvent under acidic conditions, the epoxy group is ring-opened by a trace amount of moisture to become a diol group. When the epoxy group dispersed in a polymerizable resin or a polymerizable solvent is covalently bonded to a functional group in the polymerizable resin or the polymerizable solvent, or when it is stably present with good compatibility, it is preferable that it exists in the form of an epoxy group rather than a diol group. The present invention is a sol containing silica particles bonded with an epoxy group-containing silicon compound, in which the epoxy group bonded to the silica particles does not open the ring and exists in the form of an epoxy group.

[0014] When the epoxy group-containing silicon compound is covalently bonded to the silica particles in the silica sol, the pH of the silica sol is preferably in the range of 6 to 8. Even if the pH is subsequently changed to the acidic or alkaline side, the epoxy group will be converted to a diol group. Therefore, it is preferable to store the silica particles at a pH of 6 to 8 thereafter.

[0015] Hydrolyzable groups (e.g., alkoxy groups) contained in epoxy group-containing silicon compounds are hydrolyzed more on the acidic or alkaline side than on the neutral side, and the silanol groups of the epoxy group-containing silicon compounds are bonded to the silanol groups of the silica particles, and the epoxy group-containing silicon compounds are bonded to the silica particles via siloxane bonds. When the silica sol has a pH close to neutral, the hydrolysis of the hydrolyzable groups contained in the epoxy group-containing silicon compounds is difficult to proceed, but the silica particles themselves act as hydrolysis catalysts, and silica particles to which the epoxy group-containing silicon compounds are bonded are produced.

[0016] This process occurs not only in the medium of the silica sol but also in an organic solvent, for example, in alcohol or other organic solvents, and hydrolysis and bonding proceed due to trace amounts of water present in these organic solvents. The polar groups of water and polar solvents polarize the water molecules through hydrogen bonding, making hydrolysis easier to proceed, and as a result, bonding proceeds between the silanol groups of the epoxy group-containing silicon compound and the silanol groups of the silica particles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention relates to a silica sol which contains silica particles having an epoxy group-containing silicon compound bonded thereto as a dispersoid, the silica particles being dispersed in an organic solvent as a dispersing medium, and has a pH of 6 to 8, the silica sol having an epoxy equivalent (B) of 5,000 to 25,000 (g of silica sol / equivalent), and when the silica sol is maintained at a pH of 3 to less than 6, the epoxy equivalent (A) of the silica sol (g of silica sol / equivalent) is such that the ratio B / A is less than 1.0.

[0018] The silica sol used in the present invention preferably has an average primary particle diameter of 5 to 100 nm, 5 to 60 nm, 5 to 50 nm, or 5 to 40 nm as measured by a nitrogen gas adsorption method (BET method), and an average particle diameter of 5 to 200 nm, 10 to 100 nm, or 10 to 80 nm as measured by a dynamic light scattering method (DLS method).

[0019] The epoxy group-containing silicon compound is an epoxy group-containing silicon compound containing a hydrolyzable group, and the hydrolyzable group can be an alkoxy group such as a methoxy group or an ethoxy group. The epoxy group or the epoxy group-containing organic group is a functional group formed on the silica particles (on the surface or in the vicinity) when the epoxy group-containing or epoxy group-containing organic group-containing silicon compound is added to the silica particles.

[0020] Examples of the epoxy group include a glycidyl group or a 3,4-epoxycyclohexyl group, such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

[0021] The epoxy equivalent (B) of the silica particles in the silica sol is 5000 to 25000 (silica sol g / equivalent), 5000 to 20000 (silica sol g / equivalent), or 10000 to 20000 (silica sol g / equivalent). The epoxy equivalent (A) (silica sol g / equivalent) of the silica particles when the silica sol is kept at a pH of 3 to less than 6 is 5300 to 26800 (silica sol g / equivalent), or 5300 to 21500 (silica sol g / equivalent), or 10750 to 21500 (silica sol g / equivalent). The ratio B / A can be set to less than 1.0, or 0 to less than 1.0, or 0 to 0.9, or 0 to 0.7, or 0.1 to 0.9, or 0.1 to 0.7, or 0.1 to 0.5.

[0022] The epoxy equivalent (A) (g of silica sol / equivalent) of the silica sol when the silica sol is maintained at a pH of 3 to less than 6 can be the epoxy equivalent (A) measured by maintaining an organic solvent-dispersed silica sol having an epoxy equivalent (B) of 5,000 to 25,000 (g of silica sol / equivalent) at a pH of 3 to less than 6 for 1 hour.

[0023] The epoxy equivalent of the silica particles in the silica sol can be measured by potentiometric titration using a perchloric acid / acetic acid standard solution.

[0024] In addition, in the silica sol of the present invention, the silicon atoms of the epoxy group-containing silicon compound are 0.3 to 5 atoms / nm2 per unit area of ​​the silica particles. 2 , or 0.5 to 3 particles / nm 2 It is preferable that the bond ratio is 1:

[0025] The sol of the present invention has a solid content of 0.1 to 70 mass %, or 1 to 60 mass %, or 10 to 55 mass %. Here, the solid content refers to the firing residue when the sol is fired at 1000°C. The silica sol of the present invention uses an organic material as a dispersion medium (solvent), and the dispersion medium (solvent) can be, for example, an organic material having a hydroxyl group, an organic material having a carbonyl structure, or an organic material having an epoxy group.

[0026] The organic substance having a hydroxyl group of the dispersion medium includes alcohols having 1 to 5 carbon atoms, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. The organic substance having a carbonyl structure of the dispersion medium is a ketone solvent, an amide solvent, or an ester solvent.

[0027] The ketone solvent is a linear or cyclic aliphatic ketone having 3 to 30 carbon atoms, such as methyl ethyl ketone, diethyl ketone, methyl propyl ketone, methyl isobutyl ketone, diisopropyl ketone, diisobutyl ketone, methyl amyl ketone, cyclohexanone, etc. The amide solvent is an aliphatic amide having 4 to 30 carbon atoms, such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, N-ethylpyrrolidone, etc. The ester solvent is ethyl acetate, n-propyl acetate, isopropyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, etc.

[0028] Preferred examples of the organic substance having a carbonyl structure include methyl isobutyl ketone, diisopropyl ketone, diisobutyl ketone, ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate.

[0029] The organic substance having an epoxy group is a liquid epoxy compound, and examples thereof include 1,4-butanediol diglycidyl ether, 1,2-epoxy-4-(epoxyethyl)cyclohexane, glycerol triglycidyl ether, diethylene glycol diglycidyl ether, 2,6-diglycidylphenyl glycidyl ether, 1,1,3-tris[p-(2,3-epoxypropoxy)phenyl]propane, 1,2-cyclohexanedicarboxylic acid diglycidyl ester, 4,4'-methylenebis(N,N-diglycidylaniline), 3,4-epoxy ...ether, and the like. xylmethyl-3,4-epoxycyclohexanecarboxylate, trimethylolethane triglycidyl ether, triglycidyl-p-aminophenol, tetraglycidyl metaxylenediamine, tetraglycidyl diaminodiphenylmethane, tetraglycidyl-1,3-bisaminomethylcyclohexane, bisphenol-A diglycidyl ether, bisphenol-F diglycidyl ether, bisphenol-S diglycidyl ether, pentaerythritol tetraglycidyl ether, resorcinol diglycidyl ether, phthalic acid Diglycidyl ester, neopentyl glycol diglycidyl ether, polypropylene glycol diglycidyl ether, tetrabromobisphenol-A diglycidyl ether, bisphenol hexafluoroacetone diglycidyl ether, pentaerythritol diglycidyl ether, hydrogenated bisphenol-A diglycidyl ether, tris-(2,3-epoxypropyl)isocyanurate, 1-{2,3-di(propionyloxy)}-3,5-bis(2,3-epoxypropyl)-1,3,5-triazine-2,4,6·(1H,3 H,5H)-trione, 1,3-bis{2,3-di(propionyloxy)}-5-(2,3-epoxypropyl)-1,3,5-triazine-2,4,6·(1H,3H,5H)-trione, monoallyl diglycidyl isocyanurate, diglycerol polydiglycidyl ether, pentaerythritol polyglycidyl ether, 1,4-bis(2,3-epoxypropoxyperfluoroisopropyl)cyclohexane, sorbitol polyglycidyl ether, trimethylolpropane polyglycidyl ether, resorcinol diglycidyl ether, 1,6-Hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, adipic acid diglycidyl ether, o-phthalic acid diglycidyl ether, dibromophenyl glycidyl ether, 1,2,7,8-diepoxyoctane, 1,6-dimethylolperfluorohexane diglycidyl ether, 4,4'-bis(2,3-epoxypropoxyperfluoroisopropyl)diphenyl ether, 2,2-bis(4-glycidyloxyphenyl)propane, 3,4-epoxycyclohexylmethyl-3',4' ... cyclohexane carboxylate, 3,4-epoxycyclohexyl oxirane, 2-(3,4-epoxycyclohexyl)-3',4'-epoxy-1,3-dioxane-5-spirocyclohexane, 1,2-ethylenedioxy-bis(3,4-epoxycyclohexylmethane), 4',5'-epoxy-2'-methylcyclohexylmethyl-4,5-epoxy-2-methylcyclohexane carboxylate, ethylene glycol-bis(3,4-epoxycyclohexane carboxylate), bis-(3,4-epoxycyclohexylmethyl)adipate, and bis(2,3-epoxycyclopentyl)ether.

[0030] In particular, examples of organic substances having an epoxy group include bisphenol A liquid epoxy compounds, bisphenol F liquid epoxy compounds, and 3',4'-epoxycyclohexylmethyl 3',4'-epoxycyclohexane carboxylate. Examples of bisphenol A liquid epoxy compounds include bisphenol-A-diglycidyl ether, and examples of bisphenol F liquid epoxy compounds include bisphenol-F-diglycidyl ether.

[0031] In the present invention, it is preferable to use a silica sol in which the dispersed silica particles contain aluminum atoms in an amount of 800 to 10,000 ppm / SiO2 calculated as Al2O3. By using such a silica sol, the stability is improved.

[0032] The silica sol of the present invention can be prepared by the following steps (A) to (C): Step (A): Silica particles having an average particle size of 5 to 200 nm as determined by dynamic light scattering (DLS) are dissolved in alcohol R 1 OH (but R 1 represents an organic group having 1 to 10 carbon atoms which may have an oxygen atom), and the silica sol has a water content of 5 mass % or less; Step (B): A step of adjusting the pH of the silica sol obtained in step (A) to 6 to 8; Step (C): Adding an epoxy group or an epoxy group-containing organic group (R 2 ) to coat the silica particles.

[0033] In the step (A), a silica sol can be used in which an alcohol having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms, is used as a dispersion medium. Examples of the alcohol include methanol, ethanol, n-propanol, i-propanol, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. In particular, methanol is preferred as the alcohol.

[0034] R 1 The silica sol using an alcohol having an OH structure as a dispersion medium preferably has a water content of 5% by mass or less, for example, 1.0 to 5.0% by mass, 1.2 to 5.0% by mass, or 1.2 to 3.0% by mass.

[0035] Alcohol R having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms 1 Silica sol using OH as a dispersion medium is obtained by starting with aqueous silica sol. Aqueous silica sol is obtained by a) exchanging the aqueous glass with cations to obtain active silicic acid, and b) heating the active silicic acid to obtain silica particles.

[0036] In step a), a mineral acid (e.g., hydrochloric acid, nitric acid, or sulfuric acid) is added to highly purify the activated silicic acid, and metal impurities other than silica are dissolved, and the activated silicic acid from which the metal impurities and unnecessary anions have been removed by cation exchange and anion exchange can be used. In step b), an alkali component (e.g., NaOH, KOH) is added to the activated silicic acid to grow silica particles.

[0037] In order to promote the particle growth of silica particles, a seed liquid and a feed liquid are prepared by adding an alkali to the activated silicic acid obtained in step a), and the seed liquid is heated while the feed liquid is supplied to increase the silica particle diameter, thereby making it possible to obtain an aqueous silica sol with a desired particle diameter.

[0038] More preferably, among the aqueous silica sols obtained in step b), an acidic silica sol from which alkali ions present outside the particles have been removed is suitable as the starting material for the present invention.

[0039] In the step (A) of the present invention, the aqueous medium for the aqueous silica sol is preferably an alcohol R having 1 to 4 carbon atoms. 1 OH (but R 1 represents an alkyl group having 1 to 4 carbon atoms. This alcohol can be substituted with a solvent (especially methanol) to obtain silica particles having an average particle size of 5 to 200 nm as measured by dynamic light scattering, as a dispersoid, and a silica sol can be obtained using the alcohol having 1 to 4 carbon atoms as a dispersion medium.

[0040] Step (B) is a step of adjusting the pH of the silica sol obtained in step (A) to 6 to 8. In the above pH setting, a basic substance is added to the silica sol so that it is contained in the silica sol. As the basic substance, an amine, ammonia, an inorganic alkali compound, or a quaternary ammonium compound can be used.

[0041] The pH of the silica sol of the present invention can be measured by mixing the silica sol, organic solvent, and water in a ratio of 1:1:1 with a pH meter. For example, when the organic solvent is methanol, the liquid obtained by mixing the silica sol dispersed in methanol, methanol, and pure water in a mass ratio of 1:1:1 or 1:2:1 is measured with a pH meter. When the organic solvent is methyl ethyl ketone, the liquid obtained by mixing the silica sol dispersed in methyl ethyl ketone, methanol, and pure water in a mass ratio of 1:1:1 or 1:2:1 is measured with a pH meter.

[0042] The basic substance includes amines, ammonia, inorganic alkali compounds, and quaternary ammonium compounds.

[0043] Examples of the amine include secondary amines and tertiary amines having a total of 5 to 35 carbon atoms.

[0044] Examples of the secondary amine include ethyl-n-propylamine, ethylisopropylamine, dipropylamine, diisopropylamine, ethylbutylamine, n-propylbutylamine, dibutylamine, ethylpentylamine, n-propylpentylamine, isopropylpentylamine, dipentylamine, ethyloctylamine, i-propyloctylamine, butyloctylamine, and dioctylamine.

[0045] Examples of the tertiary amine include triethylamine, ethyldi-n-propylamine, diethyl-n-propylamine, tri-n-propylamine, triisopropylamine, ethyldibutylamine, diethylbutylamine, isopropyldibutylamine, diisopropylethylamine, diisopropylbutylamine, tributylamine, ethyldipentylamine, diethylpentylamine, tri-n-pentylamine, methyldioctylamine, dimethyloctylamine, ethyldioctylamine, diethyloctylamine, trioctylamine, benzyldibutylamine, and diazabicycloundecene.

[0046] Among the above amines, secondary amines and tertiary amines having an alkyl group with a total of 5 to 35 carbon atoms are preferred, and examples thereof include diisopropylamine, tri-n-pentylamine, triisopropylamine, dimethyloctylamine, trioctylamine, and diisopropylethylamine.

[0047] Ammonia can be used in the form of gaseous ammonia or aqueous ammonia. The quaternary ammonium hydroxide is preferably a tetraalkylammonium hydroxide having a total of 4 to 40 carbon atoms, such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra-n-propylammonium hydroxide, tetra-i-propylammonium hydroxide, tetrabutylammonium hydroxide, and ethyltrimethylammonium hydroxide.

[0048] The inorganic alkali compound includes alkali metal hydroxides, such as sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[0049] In the step (C), an epoxy group or an epoxy group-containing organic group (R 2 ) to coat the silica particles.

[0050] Epoxy group or epoxy group-containing organic group (R 2 ) is a compound that contains an epoxy group or an epoxy group-containing organic group (R 2 (R)-containing silane is added to the silica particle. 2 ) include, for example, an alkyl group having 1 to 10 carbon atoms and an aryl group. The alkyl group may have a straight chain structure, a branched structure, a cyclic structure, or a combination thereof, and examples thereof include a propyl group, a cyclohexyl group, and a cyclohexylethyl group. Examples of the aryl group include a phenyl group and a phenylmethyl group.

[0051] The epoxy group is a glycidyl group or a 3,4-epoxycyclohexyl group, and examples thereof include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, etc. In particular, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltrimethoxysilane can be preferably used.

[0052] This step is a step in which the silane compound reacts with hydroxy groups on or near the surface of silica particles, for example, silanol groups in the case of silica particles, to coat the surface of the silica particles with the silane compound through siloxane bonds. This step can be carried out at a reaction temperature ranging from 0°C to the boiling point of the dispersion medium, for example, in the range of 20°C to 100°C. This step can also be carried out for a reaction time of about 0.1 to 6 hours.

[0053] The hydrolysis of the above silane compound requires water, but the alcohol R having 1 to 4 carbon atoms is 1 In the case of a sol of an OH solvent, the water remaining in the alcohol solvent when the aqueous medium is solvent-substituted with an alcohol can be used. The remaining water is the water remaining when the sol of an aqueous medium is solvent-substituted with a sol of an alcohol solvent having 1 to 4 carbon atoms, and for example, the water content of the silica sol dispersed in the alcohol can be 5% by mass or less, for example, 1.0 to 5.0% by mass, 1.2 to 5.0% by mass, or 1.2 to 3.0% by mass.

[0054] As for the catalyst, the above-mentioned basic substance also serves as a hydrolysis catalyst.

[0055] In the step (C), the epoxy group or the epoxy group-containing organic group (R 2 In addition to adding a silane containing the formula (1), a step (C-1) of adding at least one silane compound selected from the group consisting of the formulas (1) to (3) can be added.

[0056] In formula (1), R 3 each represents an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, or an organic group having a (meth)acryloyl group, a mercapto group, an amino group, a ureido group, or a cyano group, and is bonded to a silicon atom by a Si-C bond; R 4 each represents an alkoxy group, an acyloxy group, or a halogen group; a represents an integer of 1 to 3; In formula (2) and formula (3), R 5 and R 7 are each an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 30 carbon atoms and bonded to a silicon atom by a Si-C bond, and R 6 and R 8 each represents an alkoxy group, an acyloxy group, or a halogen group; Y represents an alkylene group, an NH group, or an oxygen atom; b is an integer of 1 to 3; c is an integer of 0 or 1; and d is an integer of 1 to 3.

[0057] The alkyl group is an alkyl group having 1 to 18 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, a cyclobutyl group, a 1-methyl-cyclopropyl group, a 2-methyl-cyclopropyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, a 1-ethyl -n-propyl, cyclopentyl, 1-methyl-cyclobutyl, 2-methyl-cyclobutyl, 3-methyl-cyclobutyl, 1,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-cyclopropyl, 2-ethyl-cyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n-butyl , 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl, 3,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl, 1-ethyl-2-methyl-n-propyl, cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclobutyl cyclopropyl, 3-ethyl-cyclobutyl, 1,2-dimethyl-cyclobutyl, 1,3-dimethyl-cyclobutyl, 2,2-dimethyl-cyclobutyl, 2,3-dimethyl-cyclobutyl, 2,4-dimethyl-cyclobutyl, 3,3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl, 1-i-propyl-cyclopropyl, 2-i-propyl-cyclopropyl, 1,2,2-trimethyl-cyclopropyl, 1,2,3-trimethyl-cyclopropyl, 2,2,Examples of the cyclopropyl group include, but are not limited to, 3-trimethyl-cyclopropyl group, 1-ethyl-2-methyl-cyclopropyl group, 2-ethyl-1-methyl-cyclopropyl group, 2-ethyl-2-methyl-cyclopropyl group, 2-ethyl-3-methyl-cyclopropyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group.

[0058] Examples of the alkylene group include alkylene groups derived from the above-mentioned alkyl groups.

[0059] The aryl group is an aryl group having 6 to 30 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, an anthracene group, and a pyrene group.

[0060] The alkenyl group is an alkenyl group having 2 to 10 carbon atoms, and examples of the alkenyl group include ethenyl group, 1-propenyl group, 2-propenyl group, 1-methyl-1-ethenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-ethylethenyl group, 1-methyl-1-propenyl group, 1-methyl-2-propenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 1-n-propylethenyl group, 1-methyl-1-butenyl group, 1-methyl-2-butenyl group, 1-methyl-3-butenyl group, 2-ethyl-2-propenyl group, 2-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2-methyl-3-butenyl group, 3 Examples of the aryl group include, but are not limited to, 1-methyl-1-butenyl group, 3-methyl-2-butenyl group, 3-methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1-i-propylethenyl group, 1,2-dimethyl-1-propenyl group, 1,2-dimethyl-2-propenyl group, 1-cyclopentenyl group, 2-cyclopentenyl group, 3-cyclopentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group, 5-hexenyl group, 1-methyl-1-pentenyl group, 1-methyl-2-pentenyl group, 1-methyl-3-pentenyl group, 1-methyl-4-pentenyl group, 1-n-butylethenyl group, 2-methyl-1-pentenyl group, and 2-methyl-2-pentenyl group.

[0061] The alkoxy group includes alkoxy groups having 1 to 10 carbon atoms, such as, for example, a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, an s-butoxy group, a t-butoxy group, an n-pentyloxy group, a 1-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 3-methyl-n-butoxy group, a 1,1-dimethyl-n-propoxy group, a 1,2-dimethyl-n-propoxy group, a 2,2-dimethyl-n-propoxy group, a 1-ethyl-n-propoxy group, and an n-hexyloxy group, but is not limited to these.

[0062] The acyloxy group includes acyloxy groups having 2 to 10 carbon atoms, such as a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an i-propylcarbonyloxy group, an n-butylcarbonyloxy group, an i-butylcarbonyloxy group, an s-butylcarbonyloxy group, a t-butylcarbonyloxy group, an n-pentylcarbonyloxy group, a 1-methyl-n-butylcarbonyloxy group, a 2-methyl-n-butylcarbonyloxy group, a 3-methyl-n-butylcarbonyloxy group, a 1,1-dimethyl-n-propylcarbonyloxy group, a 1,2-dimethyl-n-propylcarbonyloxy group, a 2,2-dimethyl-n-propylcarbonyloxy group, a 1-ethyl-n-propylcarbonyloxy group, an n-hexylcarbonyloxy group, a 1-methyl-n-pentylcarbonyloxy group, and a 2-methyl-n-pentylcarbonyloxy group, but is not limited to these.

[0063] The halogen group includes fluorine, chlorine, bromine, iodine, and the like.

[0064] The (meth)acryloyl group refers to both acryloyl and methacryloyl groups. Examples of organic groups having a (meth)acryloyl group include a 3-methacryloxypropyl group and a 3-acryloxypropyl group. An example of the organic group having a mercapto group is a 3-mercaptopropyl group.

[0065] Examples of organic groups having an amino group include a 2-aminoethyl group, a 3-aminopropyl group, an N-2-(aminoethyl)-3-aminopropyl group, an N-(1,3-dimethyl-butylidene)aminopropyl group, an N-phenyl-3-aminopropyl group, and an N-(vinylbenzyl)-2-aminoethyl-3-aminopropyl group.

[0066] An example of the organic group having a ureido group is a 3-ureidopropyl group.

[0067] An example of the organic group having a cyano group is a 3-cyanopropyl group.

[0068] The silica compounds represented by the above formulas (2) and (3) are preferably compounds capable of forming trimethylsilyl groups on the surface of silica particles.

[0069] Examples of such compounds include the following:

[0070] [ka]

[0071] In the above formula, R 12 is an alkoxy group, examples of which include a methoxy group and an ethoxy group.

[0072] Preferred functional groups are trimethylsilyl, monomethylsilyl, dimethylsilyl, methacryloxypropylsilyl, and phenyl groups, and corresponding silane compounds include hexamethyldisilazane, hexamethylsiloxane, hexamethyldisiloxane, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, acryloxypropyltrimethoxysilane, acryloxypropyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane.

[0073] The silane compound is represented by the formula (1) (R 3 is an organic group having an aryl group and bonded to a silicon atom by a Si-C bond, 4 each represents an alkoxy group, an acyloxy group, or a halogen group, and a represents an integer of 1 to 3.) is preferable, and examples thereof include phenyltriethoxysilane and phenyltrimethoxysilane.

[0074] In step (D), the dispersion medium of the silica sol obtained in step (C) is changed to alcohol R1 This is a process of replacing OH with an organic substance having a carbonyl structure or an organic substance having an epoxy group.

[0075] The organic substance having a carbonyl structure is a ketone solvent, an amide solvent, or an ester solvent, and the organic substance having an epoxy group is a liquid epoxy compound, specific examples of which include the compounds exemplified above.

[0076] In step (D), the dispersion medium is alcohol R 1 After the OH group has been replaced with an organic substance having a carbonyl structure, a step (D-1) of replacing the OH group with an organic substance having an epoxy group can be carried out.

[0077] In the present invention, a silica sol containing an organic material having a carbonyl structure as a dispersion medium, and a silica sol containing an organic material having an epoxy group as a dispersion medium can be obtained. Either silica sol can be made into a cured product by containing a curing agent such as an amine-based curing agent, an acid anhydride-based curing agent, or an acid generator-based curing agent (thermal acid generator or photoacid generator). A cured product can be formed by applying a cured product-forming composition containing silica sol and a curing agent to a substrate and heating, irradiating with light, or a combination thereof. The cured product-forming composition can further contain an epoxy resin.

[0078] In the case of a thermosetting composition for forming a cured product, the thermosetting agent may be contained in an amount of 0.5 to 1.5 equivalents, preferably 0.8 to 1.2 equivalents, relative to the epoxy group. The equivalent of the thermosetting agent relative to the epoxy compound is represented by the equivalent ratio of the curable group of the thermosetting agent to the epoxy group.

[0079] Examples of the heat curing agent include phenol resins, amine-based curing agents, polyamide resins, imidazoles, polymercaptans, acid anhydrides, heat acid generators, etc. In particular, acid anhydride-based curing agents and amine-based curing agents are preferred.

[0080] Even if these thermosetting agents are solid, they can be used by dissolving them in a solvent. However, evaporation of the solvent reduces the density of the cured product and creates pores, resulting in reduced strength and reduced water resistance. Therefore, it is preferable for the curing agent itself to be liquid at room temperature and normal pressure.

[0081] Examples of the phenol resin include phenol novolac resin and cresol novolac resin.

[0082] Examples of the amine curing agent include piperidine, N,N-dimethylpiperazine, triethylenediamine, 2,4,6-tris(dimethylaminomethyl)phenol, benzyldimethylamine, 2-(dimethylaminomethyl)phenol, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, di(1-methyl-2-aminocyclohexyl)methane, menthenediamine, isophoronediamine, diaminodicyclohexylmethane, 1,3-diaminomethylcyclohexane, xylylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, 3,3'-diethyl-4,4'-diaminodiphenylmethane, and diethyltoluenediamine. Of these, liquid diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, N-aminoethylpiperazine, di(1-methyl-2-aminocyclohexyl)methane, menthenediamine, isophoronediamine, diaminodicyclohexylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, diethyltoluenediamine, etc. can be preferably used.

[0083] The polyamide resin is produced by condensation of a dimer acid and a polyamine, and a polyamideamine having a primary amine and a secondary amine in the molecule is preferred.

[0084] Examples of the imidazoles include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, and epoxy imidazole adduct.

[0085] The polymercaptan is, for example, one having a mercaptan group at the end of a polypropylene glycol chain or one having a mercaptan group at the end of a polyethylene glycol chain, and is preferably in a liquid form.

[0086] As the acid anhydride curing agent, the anhydride of the compound having a plurality of carboxyl groups in one molecule is preferred.As these acid anhydride curing agents, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bis trimellitate, glycerol tris trimellitate, maleic anhydride, tetrahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, endomethylene tetrahydrophthalic anhydride, methyl endomethylene tetrahydrophthalic anhydride, methyl butenyl tetrahydrophthalic anhydride, dodecenyl succinic anhydride, hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, succinic anhydride, methylcyclohexene dicarboxylic anhydride, chlorendic anhydride, etc. can be mentioned.

[0087] Examples of the thermal acid generator include sulfonium salts and phosphonium salts, and among these, sulfonium salts are preferably used. For example, the following compounds can be mentioned.

[0088] [ka]

[0089] R may be an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 20 carbon atoms, and is particularly preferably an alkyl group having 1 to 12 carbon atoms.

[0090] Among these, the following are preferred, which are liquid at room temperature and pressure: methyltetrahydrophthalic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride (methylnadic anhydride, methylhimic anhydride), hydrogenated methylnadic anhydride, methylbutenyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, methylhexahydrophthalic anhydride, and a mixture of methylhexahydrophthalic anhydride and hexahydrophthalic anhydride. These liquid acid anhydrides have a viscosity of about 10 mPa·s to 1000 mPa·s when measured at 25°C.

[0091] In addition, when obtaining the above-mentioned cured product, a curing assistant may be used in combination as appropriate. Examples of the curing assistant include organic phosphorus compounds such as triphenylphosphine and tributylphosphine, quaternary phosphonium salts such as ethyltriphenylphosphonium bromide and methyltriphenylphosphonium diethyl phosphate, quaternary ammonium salts such as 1,8-diazabicyclo(5,4,0)undecane-7-ene, salts of 1,8-diazabicyclo(5,4,0)undecane-7-ene and octylic acid, zinc octylate, and tetrabutylammonium bromide. These curing assistants can be contained in a ratio of 0.001 to 0.1 parts by mass relative to 1 part by mass of the curing agent.

[0092] Epoxy group or epoxy group-containing organic group (R 2 ) and alkoxy groups (OR 1 A silica sol of silica particles containing the epoxy resin or a composition further containing an epoxy resin can be mixed with a curing agent and, if desired, a curing aid to obtain a thermosetting composition (a thermosetting composition for forming a cured product). The mixing can be carried out in a reaction vessel using a stirring blade or a kneader.

[0093] The mixing is carried out by a hot mixing method at a temperature of 60° C. to 100° C. for 0.5 to 1 hour.

[0094] The obtained liquid epoxy resin composition (thermosetting composition) is a thermosetting composition and has an appropriate viscosity for use, for example, as a liquid encapsulant. The liquid thermosetting composition can be prepared to any viscosity, and can be used as a transparent encapsulant for LEDs and the like by casting, potting, dispenser, printing, or the like, allowing partial encapsulation at any desired location. The liquid thermosetting composition is directly mounted on an LED or the like in liquid form by the above-mentioned method, and then dried and cured to obtain a cured epoxy resin body.

[0095] The thermosetting composition is applied to a substrate and heated at a temperature of 80 to 200° C. to obtain a cured product.

[0096] In the case of a photocurable composition (photocurable composition for forming a cured product), the photocuring agent (photoacid generator) may be contained in an amount of 0.5 to 20% by mass, preferably 0.8 to 10% by mass, based on the epoxy groups.

[0097] The photoacid generator is not particularly limited as long as it generates an acid directly or indirectly upon irradiation with light.

[0098] Specific examples of the photoacid generator that can be used include triazine-based compounds, acetophenone derivative compounds, disulfone-based compounds, diazomethane-based compounds, sulfonic acid derivative compounds, onium salts such as iodonium salts, sulfonium salts, phosphonium salts, and selenium salts, metallocene complexes, and iron arene complexes.

[0099] Among the onium salts used as the photoacid generator, examples of the iodonium salt include diphenyliodonium chloride, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium mesylate, diphenyliodonium tosylate, diphenyliodonium bromide, diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluoroarsenate, bis(p-tert-butylphenyl)iodonium hexafluorophosphate, bis(p-tert-butylphenyl)iodonium mesylate, bis(p-tert-butylphenyl)iodonium tosylate, bis(p-tert-butylphenyl)iodonium trifluoromethanesulfonate, bis(p-tert-butylphenyl)iodonium trifluoromethanesulfonate, and bis(p-tert-butylphenyl)iodonium trifluoromethanesulfonate. )iodonium tetrafluoroborate, bis(p-tert-butylphenyl)iodonium chloride, bis(p-chlorophenyl)iodonium chloride, bis(p-chlorophenyl)iodonium tetrafluoroborate, further bis(alkylphenyl)iodonium salts such as bis(4-t-butylphenyl)iodonium hexafluorophosphate, alkoxycarbonylalkoxy-trialkylaryliodonium salts (e.g., 4-[(1-ethoxycarbonyl-ethoxy)phenyl]-(2,4,6-trimethylphenyl)-iodonium hexafluorophosphate, etc.), bis(alkoxyaryl)iodonium salts (e.g., bis(alkoxyphenyl)iodonium salts such as (4-methoxyphenyl)phenyliodonium hexafluoroantimonate, etc.).

[0100] Examples of the sulfonium salt include triphenylsulfonium salts such as triphenylsulfonium chloride, triphenylsulfonium bromide, tri(p-methoxyphenyl)sulfonium tetrafluoroborate, tri(p-methoxyphenyl)sulfonium hexafluorophosphonate, tri(p-ethoxyphenyl)sulfonium tetrafluoroborate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, and triphenylsulfonium hexafluorophosphate; and sulfonium salts such as (4-phenylthiophenyl)diphenylsulfonium hexafluoroantimonate, (4-phenylthiophenyl)diphenylsulfonium hexafluorophosphate, bis[4-(diphenylsulfonio)phenyl]sulfide-bis-hexafluoroantimonate, bis[4-(diphenylsulfonio)phenyl]sulfide-bis-hexafluorophosphate, and (4-methoxyphenyl)diphenylsulfonium hexafluoroantimonate.

[0101] Examples of the phosphonium salt include triphenylphosphonium chloride, triphenylphosphonium bromide, tri(p-methoxyphenyl)phosphonium tetrafluoroborate, tri(p-methoxyphenyl)phosphonium hexafluorophosphonate, tri(p-ethoxyphenyl)phosphonium tetrafluoroborate, 4-chlorobenzenediazonium hexafluorophosphate, and benzyltriphenylphosphonium hexafluoroantimonate.

[0102] Other examples of photoacid generators include selenium salts such as triphenylselenium hexafluorophosphate, and metallocene complexes such as (η5 or η6-isopropylbenzene)(η5-cyclopentadienyl)iron(II) hexafluorophosphate.

[0103] In addition, the following compounds can also be used as the photoacid generator.

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109] [ka]

[0110] [ka]

[0111] [ka]

[0112] [ka]

[0113] As the photoacid generator, sulfonium salt compounds and iodonium salt compounds are preferred. The anion species thereof is CF3SO3 - , C4F9SO3 - , C8F 17 SO3 - , camphorsulfonate anion, tosylate anion, BF4 - , PF6- , AsF6 - and SbF6 - In particular, anion species such as phosphorus hexafluoride and antimony hexafluoride, which exhibit strong acidity, are preferred.

[0114] The cured body-forming composition of the present invention may contain conventional additives as necessary. Examples of such additives include pigments, colorants, thickeners, sensitizers, defoamers, leveling agents, coating improvers, lubricants, stabilizers (antioxidants, heat stabilizers, light resistance stabilizers, etc.), plasticizers, surfactants, dissolution promoters, fillers, antistatic agents, curing agents, etc. These additives may be used alone or in combination of two or more.

[0115] Examples of the coating method include flow coating, spin coating, spray coating, screen printing, casting, bar coating, curtain coating, roll coating, gravure coating, dipping, and slit coating.

[0116] In the present invention, the photocurable composition for forming a cured body can be applied onto a substrate and cured by irradiation with light. Heating can also be performed before or after the irradiation with light.

[0117] The thickness of the coating film can be selected from the range of about 0.01 μm to 10 mm depending on the application of the cured product. For example, when used as a photoresist, it can be about 0.05 to 10 μm (particularly 0.1 to 5 μm), when used as a printed wiring board, it can be about 5 μm to 5 mm (particularly 100 μm to 1 mm), and when used as an optical thin film, it can be about 0.1 to 100 μm (particularly 0.3 to 50 μm).

[0118] When a photoacid generator is used, the light to be irradiated or exposed may be, for example, gamma rays, X-rays, ultraviolet rays, visible light, etc., and is usually visible light or ultraviolet rays, particularly ultraviolet rays. The wavelength of the light is, for example, about 150 to 800 nm, preferably 150 to 600 nm, more preferably 200 to 400 nm, and particularly preferably about 300 to 400 nm. The amount of irradiation light varies depending on the thickness of the coating film, but is, for example, 2 to 20,000 mJ / cm. 2 , preferably 5 to 5000 mJ / cm 2 It can be about that.

[0119] The light source can be selected according to the type of light to be exposed, and for example, in the case of ultraviolet light, a low pressure mercury lamp, a high pressure mercury lamp, an ultra-high pressure mercury lamp, a deuterium lamp, a halogen lamp, laser light (helium-cadmium laser, excimer laser, etc.) can be used. Such light irradiation causes the curing reaction of the composition to proceed.

[0120] When a thermal acid generator is used, or when a photoacid generator is used, the coating film is heated as necessary after light irradiation, for example at 60 to 250° C., and preferably at about 100 to 200° C. The heating time can be selected within a range of 3 seconds or more (for example, about 3 seconds to 5 hours), for example, 5 seconds to 2 hours, preferably about 20 seconds to 30 minutes, and usually about 1 minute to 3 hours (for example, about 5 minutes to 2.5 hours).

[0121] Furthermore, when forming a pattern or an image (for example, when manufacturing a printed wiring board, etc.), the coating film formed on the substrate may be pattern-exposed, and this pattern exposure may be performed by scanning with laser light or by irradiating light through a photomask. A pattern or an image can be formed by developing (or dissolving) the non-irradiated area (unexposed part) generated by such pattern exposure with a developer.

[0122] The developer may be an alkaline aqueous solution or an organic solvent.

[0123] Examples of the alkaline aqueous solution include aqueous solutions of alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, potassium carbonate, and sodium carbonate; aqueous solutions of quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline; and aqueous solutions of amines such as ethanolamine, propylamine, and ethylenediamine.

[0124] The alkaline developer is generally an aqueous solution of 10% by mass or less, and preferably an aqueous solution of 0.1 to 3.0% by mass, etc. Furthermore, alcohols and surfactants can be added to the developer, and each of these is preferably 0.05 to 10 parts by mass relative to 100 parts by mass of the developer.

[0125] Of these, an aqueous solution of 0.1 to 2.38 mass % tetramethylammonium hydroxide can be used.

[0126] In addition, the organic solvent used as the developer can be a general organic solvent, such as acetone, acetonitrile, toluene, dimethylformamide, methanol, ethanol, isopropanol, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, propylene glycol butyl ether acetate, ethyl lactate, cyclohexanone, etc., and can be used alone or in combination of two or more of these. In particular, propylene glycol methyl ether, propylene glycol methyl ether acetate, ethyl lactate, etc. can be preferably used.

[0127] In the present invention, a surfactant may be added to improve the coating property. Such surfactants are not particularly limited to fluorine-based surfactants, silicone-based surfactants, nonionic surfactants, etc. One or more of the above surfactants may be used in combination.

[0128] Among these surfactants, fluorine-based surfactants are preferred because of their high coating property improving effect.Specific examples of fluorine-based surfactants include, but are not limited to, F-TOP EF301, EF303, EF352 (Tokem Products Co., Ltd. product names), Megafac F171, F173, R-30, R-40, R-08, R-90, BL-20, F-482 (Dainippon Ink and Chemicals Co., Ltd. product names), Fluorad FC430, FC431 (Sumitomo 3M Co., Ltd. product names), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd. product names).

[0129] The amount of the surfactant added in the cured body-forming composition of the present invention is 0.0008 to 4.5 mass %, preferably 0.0008 to 2.7 mass %, and more preferably 0.0008 to 1.8 mass %, based on the solid content.

[0130] In the present invention, an adhesion promoter can be added for the purpose of improving adhesion to the substrate after development. These adhesion promoters include chlorosilanes such as trimethylchlorosilane, dimethylvinylchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane, alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylvinylethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane, silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilylimidazole, vinyltrichlorosilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane. Examples of the heterocyclic compounds include silanes such as aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-(N-piperidinyl)propyltrimethoxysilane; heterocyclic compounds such as benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, urazole, thiouracil, mercaptoimidazole, and mercaptopyrimidine; and ureas such as 1,1-dimethylurea and 1,3-dimethylurea, or thiourea compounds.

[0131] The adhesion promoters may be used alone or in combination of two or more. The amount of these adhesion promoters added is usually 18% by mass or less, preferably 0.0008 to 9% by mass, and more preferably 0.04 to 9% by mass, based on the solid content.

[0132] In the present invention, a sensitizer may be contained. Examples of sensitizers that can be used include anthracene, phenothiazene, perylene, thioxanthone, and benzophenone thioxanthone. Examples of sensitizing dyes include thiopyrylium salt dyes, merocyanine dyes, quinoline dyes, styrylquinoline dyes, ketocoumarin dyes, thioxanthene dyes, xanthene dyes, oxonol dyes, cyanine dyes, rhodamine dyes, and pyrylium salt dyes.

[0133] Particularly preferred is an anthracene-based sensitizer, which, when used in combination with a cationic curing catalyst (radiation-sensitive cationic polymerization initiator), dramatically improves sensitivity and also has a radical polymerization initiation function, and in the hybrid type of the present invention in which the cationic curing system and the radical curing system are used in combination, the catalyst type can be simplified. Specific examples of anthracene compounds that are effective include dibutoxyanthracene and dipropoxyanthraquinone. The amount of the sensitizer added is 0.01 to 20% by mass, preferably 0.01 to 10% by mass, based on the solid content.

[0134] In the present invention, a cured body-forming composition containing an epoxy compound is photocured or thermally cured using a photoacid generator or a thermal acid generator. Because a photoacid generator or a thermal acid generator is used, commonly used epoxy curing agents (e.g., amines and acid anhydrides) are not used, or even if they are used, their content is extremely small, so that the storage stability of the composition containing the epoxy compound is improved.

[0135] The inventors have found that the composition containing the liquid epoxy compound has photocationic polymerizability. It has a higher curing speed than conventional liquid epoxy compounds (e.g., alicyclic epoxy compounds having an epoxycyclohexyl ring). Because of the fast curing speed, it is possible to reduce the amount of acid generator added and to use a weak acid generator. Reducing the amount of acid generator is important in preventing metal corrosion because acid active species may remain even after UV irradiation. Because of the fast curing speed, thick film curing is possible.

[0136] Curing by UV irradiation can be applied to materials (equipment) that are sensitive to heat.

[0137] The thermosetting material and photocurable material using the cured body-forming composition containing the epoxy compound of the present invention have characteristics such as fast curing, transparency, small curing shrinkage, etc., and can be used for coating and bonding electronic parts, optical parts, and precision mechanical parts. For example, they can be used for bonding parts such as mobile phone and camera lenses, optical elements such as light-emitting diodes (LEDs) and semiconductor lasers (LDs), liquid crystal panels, biochips, camera lenses and prisms, magnetic parts of hard disks of personal computers, etc., pickups of CD and DVD players (parts that capture optical information reflected from the disk), speaker cones and coils, motor magnets, circuit boards, electronic parts, and parts inside the engine of automobiles, etc.

[0138] As a hard coating material for surface protection of automobile bodies, lamps, electrical appliances, building materials, plastics, etc., it can be applied to, for example, automobile and motorcycle bodies, headlight lenses and mirrors, plastic lenses for glasses, mobile phones, game consoles, optical films, ID cards, etc.

[0139] Other applications for ink materials printed on metals such as aluminum and plastics include printing inks for cards such as credit cards and membership cards, switches for electrical appliances and office equipment, and keyboards, as well as inks for inkjet printers for CDs and DVDs.

[0140] Further applications include a technology for hardening resin in combination with 3D CAD to create complex three-dimensional objects, photolithography for producing models of industrial products, coating of optical fibers, adhesion, optical waveguides, thick-film resists, etc.

[0141] In addition, the cured body-forming composition containing the epoxy compound of the present invention can be suitably used as an insulating resin for electronic materials such as semiconductor sealing materials, adhesives for electronic materials, materials for printed wiring boards, materials for interlayer insulating films, and sealing materials for power modules, as well as an insulating resin for use in high-voltage equipment such as generator coils, transformer coils, and gas-insulated switchgear. EXAMPLES

[0142] [Measurement of SiO2 concentration] The silica sol was placed in a crucible, dried at 130°C, and then fired at 1000°C, and the firing residue was weighed and calculated. [Measurement of average primary particle size (nitrogen adsorption particle size / BET method)] The specific surface area of ​​the silica sol powder dried at 300° C. was measured using a specific surface area measuring device Monosorb (product name) MS-16 (manufactured by Yuasa Ionics Co., Ltd.). [Measurement of Viscosity] The viscosity of the organic solvent-dispersed silica sol was measured using an Ostwald viscometer at 20° C. The viscosity of the resin monomer-dispersed sol was measured using a B-type rotational viscometer (manufactured by Toki Sangyo Co., Ltd.). [Measuring average particle size using dynamic light scattering / DLS method] The average particle size of the silica sol was measured by dynamic light scattering by diluting the sol with various dispersion solvents to a predetermined concentration, and measuring the average particle size using a dynamic light scattering particle size measuring device (manufactured by Malvern Instruments LTD, product name ZETASIZER Nano series).

[0143] [pH Measurement] The pH of the silica sol was measured by adjusting a mixture of silica sol, methanol, and pure water in a mass ratio of 1:1:1 to 20°C and using a pH meter (manufactured by DKK-TOA Corporation, product name MM-43X). The pH measured by this method was expressed as pH(1+1+1). [Moisture content] The amount of water contained in the silica sol was measured by Karl Fischer titration using a Karl Fischer moisture meter (manufactured by Kyoto Electronics Manufacturing Co., Ltd., product name: MKA-610). [Organic solvent content] The content of the organic solvent in the silica sol was determined by gas chromatography (manufactured by Shimadzu Corporation, product name GC-2014s).

[0144] [Preparation for measuring epoxy equivalent (A)] Acetic acid was added to the silica sol, and a liquid of silica sol, methanol, and pure water in a mass ratio of 1:1:1 was adjusted to pH 4 and maintained for 1 hour. [Epoxy equivalent (B) measurement] An appropriate amount of silica sol was collected in a glass beaker, 10 mL of chloroform or acetone was added, and the mixture was stirred using a magnetic stirrer. 20 mL of acetic acid was added to the solution, followed by 20 mL of tetraethylammonium bromide acetate solution (0.25 g / mL acetic acid) and stirring. After that, the solution was titrated potentiometrically with a perchloric acid-acetic acid standard solution (0.1 mol / L) using an automatic titrator (manufactured by HIRANUMA Co., Ltd., product name COM-1700A), and the epoxy equivalent was calculated according to JIS K7236 (2001). [Epoxy equivalent (A) measurement] The silica sol prepared for the measurement of the epoxy equivalent (A) was collected in an appropriate amount in a glass beaker, 10 mL of chloroform or acetone was added, and the mixture was stirred using a magnetic stirrer. 20 mL of acetic acid was added to the solution, followed by 20 mL of tetraethylammonium bromide acetate solution (0.25 g / mL acetic acid) and stirring. After that, the solution was titrated potentiometrically with a perchloric acid-acetic acid standard solution (0.1 mol / L) using an automatic titrator (manufactured by HIRANUMA Co., Ltd., product name COM-1700A), and the epoxy equivalent was calculated according to JIS K7236 (2001).

[0145] [Calculation of epoxy equivalent ratio (B / A)] The epoxy equivalent ratio was calculated from the values ​​obtained in the epoxy equivalent measurements (A) and (B) according to the following formula.

[0146] Epoxy equivalent ratio (B / A) = epoxy equivalent (B) / epoxy equivalent (A)

[0147] [Calculation of the number of epoxy groups bonded] 4 mL of silica sol was placed in a centrifuge tube, 20 mL of hexane was added, and the tube was set in a high-speed cooling centrifuge (Tomy Kogyo Co., Ltd., product name Suprema21) and centrifuged at 5°C, 5,000 rpm, and 30 minutes. The tube was then separated into a supernatant and a precipitate, and the supernatant was collected. 8 mL of acetone was then added to the precipitate, which was then redispersed, after which 10 mL of hexane was added and centrifuged again. The centrifugation process was performed 3 to 5 times. The collected supernatant was heated in a rotary evaporator at a reduced pressure of 500 to 100 Torr and a bath temperature of 80°C for 30 minutes to 1 hour to distill off the solvent. The silane coupling agent remaining in the flask was weighed, and the weight of the silane coupling agent bonded to the particles was obtained from the difference with the amount of the silane coupling agent charged. If necessary, the amount of silica that did not settle and was dispersed in the supernatant was subtracted from the weight after distillation of the solvent. The number of epoxy groups bonded (pieces / nm 2 ) was calculated. [Measurement of Al2O3] The silica sol was collected on a platinum dish, and ultrapure water, hydrochloric acid, sulfuric acid, and hydrofluoric acid were added. The silica was removed by heating. Ultrapure water was then added to adjust the concentration to prepare the measurement stock solution. The measurement stock solution was diluted to a specified ratio, and the Al in the silica sol was measured using an ICP-MS (Agilent 8900, Agilent Technologies). The Al was then converted to Al2O3 and divided by the silica concentration in the silica sol to calculate the Al2O3 (ppm / SiO2) relative to silica.

[0148] Example 1 Water-dispersed silica sol 1 (average primary particle size by BET method: 22 nm, pH 2 to 3, silica concentration: 40 mass %, manufactured by Nissan Chemical Industries, Ltd.) was prepared. The water in 14,000 g of the above silica sol was replaced with methanol using ultrafiltration. When the water content in the sol reached 0.5 mass%, the replacement was stopped, and 14,000 g of methanol-dispersed silica sol 1 was obtained. The obtained methanol-dispersed silica sol 1 had an SiO2 concentration of 40.6 mass%, water content of 0.5 mass%, viscosity of 5.4 mPa s, Na content of 2210 ppm relative to SiO2, and SO4 content of 0.7 ppm relative to SiO2.

[0149] 200 g of the above methanol-dispersed silica sol 1 was charged into a 500 mL eggplant flask, and 1.9 g of ultrapure water was added while stirring with a magnetic stirrer. Then, 0.15 g of diisopropylethylamine (DiPEA) was added while stirring, and the pH (1+1+1) was adjusted to 7.1. Then, 4.1 g of glycidoxypropyltrimethoxysilane (trade name KBM-403, Shin-Etsu Chemical Co., Ltd.) was added while stirring, and the liquid temperature was kept at 60°C for 2 hours. Then, 6.8 g of phenyltrimethoxysilane (trade name KBM-103, Shin-Etsu Chemical Co., Ltd.) was added while stirring, and the liquid temperature was kept at 60°C for 2 hours.

[0150] Next, MEK was added to the sol to dilute the SiO2 to 30 mass%, and then MEK was added while evaporating and distilling off the solvent in a rotary evaporator at a reduced pressure of 500 to 450 Torr and a bath temperature of 80°C. The dispersion medium of the sol was replaced with MEK to obtain MEK-dispersed silica sol 1 (SiO2 30.2 mass%, viscosity (20°C) 1.4 mPa·s, moisture 0.04 mass%, methanol 0.2 mass%, dynamic light scattering average particle size 49.5 nm, epoxy equivalent (B) 15,700 (silica sol g / equivalent), epoxy equivalent (A) 16,600 (silica sol g / equivalent), epoxy equivalent (B / A) 0.95, Al2O3 4,900 ppm / SiO2).

[0151] Example 2 400 g of the methanol-dispersed silica sol 1 described in Example 1 was charged into a 1 L eggplant flask, and 4.1 g of ultrapure water was added while stirring with a magnetic stirrer. Then, 0.29 g of DiPEA was added while stirring, and the pH (1+1+1) was adjusted to 7.5. Then, 8.0 g of glycidoxypropyltrimethoxysilane (trade name KBM-403, Shin-Etsu Chemical Co., Ltd.) was added while stirring, and the liquid temperature was kept at 60 ° C for 2 hours to obtain methanol-dispersed silica sol 2 (SiO2 40.1 mass%, viscosity (20 ° C) 6.8 mPa s, moisture 1.4 mass%, dynamic light scattering average particle size 32.7 nm, epoxy equivalent (B) 11800 (silica sol g / equivalent), epoxy equivalent (A) 12400 (silica sol g / equivalent), epoxy equivalent (B / A) 0.95, The silicon atoms of the epoxy group-containing silicon compound are 0.95 / nm2 per unit area of ​​the silica particle. 2 , Al2O3 4900 ppm / SiO2) was obtained.

[0152] Example 3 150 g of the methanol-dispersed silica sol 2 obtained in Example 2 was placed in a 300 mL eggplant flask, and MEK was added to dilute SiO2 to 30 mass%. Thereafter, MEK replacement was performed in the same manner as in Example 1 to obtain MEK-dispersed silica sol 2 (SiO2 30.0 mass%, viscosity (20°C) 1.5 mPa·s, moisture 0.4 mass%, methanol 3.8 mass%, dynamic light scattering average particle size 43.8 nm, epoxy equivalent (B) 16000 (silica sol g / equivalent), epoxy equivalent (A) 17200 (silica sol g / equivalent), epoxy equivalent (B / A) 0.93, and the number of Si atoms of the epoxy group-containing silicon compound per unit area of ​​the silica particles was 0.98 / nm 2 , Al2O3 4900 ppm / SiO2) was obtained.

[0153] Example 4 40.0 g of the MEK-dispersed silica sol 2 obtained in Example 3 was placed in a 300 mL eggplant flask, and 37.0 g of an alicyclic epoxy monomer (product name CEL-2021P, manufactured by Daicel Corporation) was added and dissolved. After that, the mixture was heated in a rotary evaporator at a reduced pressure of 300 to 100 Torr and a bath temperature of 80°C for 1 hour to distill off most of the solvent. After that, the mixture was heated at a reduced pressure of 50 Torr and a bath temperature of 80°C for 3 hours to distill off the solvent, thereby obtaining epoxy monomer-dispersed sol 1 (B-type viscosity (25°C) 910 mPa s, average particle size by dynamic light scattering method 63.3 nm).

[0154] Comparative Example 1 A 3L glass reactor equipped with a stirrer, a condenser, a thermometer and two inlets was charged with 2,500 g of water-dispersed silica sol 1 (average primary particle size 22 nm, pH 2-3, silica concentration 40 mass%, Nissan Chemical Co., Ltd.), and heated to boil the silica sol. While the silica sol in the reactor was boiling, methanol steam generated in a separate boiler was continuously blown into the silica sol in the reactor to replace the water, which was the dispersion medium, with methanol. When the water content of the methanol dispersion became 3.0 mass% or less, the replacement was stopped, and 2,500 g of methanol-dispersed silica sol 3 was obtained. The obtained methanol-dispersed silica sol 3 had a SiO2 concentration of 40.4 mass%, a water content of 2.1 mass%, and a viscosity of 2.3 mPa·s.

[0155] 250 g of the above methanol-dispersed silica sol 3 was charged into a 500 mL eggplant flask, and 0.09 g of tri-n-pentylamine was added while stirring with a magnetic stirrer, and the pH (1+1+1) was adjusted to 4.3. Then, 2.6 g of glycidoxypropylmethyldiethoxysilane (trade name KBE-402, Shin-Etsu Chemical Co., Ltd.) was added while stirring, and the liquid temperature was kept at 60°C for 3 hours. Then, 4.1 g of phenyltrimethoxysilane (trade name KBM-103, Shin-Etsu Chemical Co., Ltd.) was added while stirring, and the liquid temperature was kept at 60°C for 3 hours.

[0156] Thereafter, MEK was supplied while evaporating and distilling off the solvent in a rotary evaporator at a reduced pressure of 250 to 200 Torr and a bath temperature of 60°C, and the dispersion medium of the sol was replaced with MEK to obtain MEK-dispersed silica sol 3 (SiO2 40.2 mass%, viscosity (20°C) 2.8 mPa·s, moisture 0.3 mass%, methanol 0.6 mass%, average particle size by dynamic light scattering 40.2 nm, epoxy equivalent (B) 123,700 (silica sol g / equivalent), epoxy equivalent (A) 123,700 (silica sol g / equivalent), epoxy equivalent (B / A) 1.0, Al2O3 4,900 ppm / SiO2).

[0157] Comparative Example 2 Water-dispersed silica sol 1 (average primary particle size 22 nm, pH 2 to 3, silica concentration 40 mass %, manufactured by Nissan Chemical Industries, Ltd.) was prepared. The water in 14,000 g of the above silica sol was replaced with methanol by ultrafiltration. When the water content in the sol reached 0.5 mass%, the replacement was stopped, and 14,000 g of methanol-dispersed silica sol 1 was obtained. The obtained methanol-dispersed silica sol 1 had a SiO2 concentration of 40.6 mass%, water content of 0.5 mass%, pH (1+1+1) = 3.5, viscosity of 5.4 mPa s, Na of 2210 ppm relative to SiO2, and SO4 of 0.7 ppm relative to SiO2.

[0158] 400g of methanol-dispersed silica sol 1 was placed in a 1L eggplant flask, and 4.1g of ultrapure water was added while stirring with a magnetic stirrer. Then, 8.0g of glycidoxypropyltrimethoxysilane (product name KBM-403, Shin-Etsu Chemical) was added while stirring, and the liquid temperature was kept at 60°C for 2 hours to obtain methanol-dispersed silica sol 4 (SiO2 40.1 mass%, viscosity (20°C) 9.2mPa·s, moisture 1.4 mass%, dynamic light scattering average particle size 29.1nm, epoxy equivalent (B) not detected, Al2O3 4900ppm / SiO2).

[0159] Comparative Example 3 150 g of the methanol-dispersed silica sol 2 obtained in Comparative Example 2 was placed in a 300 mL recovery flask, and MEK was added to dilute SiO2 to 30 mass %. Thereafter, MEK replacement was performed in the same manner as in Example 1, but gelation occurred during the replacement, and therefore no MEK-dispersed sol was obtained. [Industrial Applicability]

[0160] The present invention provides a sol and a resin composition containing silica particles to which an epoxy group-containing silicon compound is bonded, the epoxy group being present in the form of an epoxy group by suppressing ring-opening of the epoxy group bonded to the silica particles.

Claims

1. A silica sol containing silica particles having an epoxy group-containing silicon compound bonded thereto as a dispersoid and an organic solvent as a dispersion medium, the silica particles being dispersed in the organic solvent, and having a pH of 6 to 8, the silica sol having an epoxy equivalent (B) of 5,000 to 25,000 (g of silica sol / equivalent), and when the silica sol is maintained at a pH of 3 to less than 6, the epoxy equivalent (A) of the silica sol (g of silica sol / equivalent) is such that the ratio B / A is less than 1.

0.

2. The silicon atoms of the epoxy group-containing silicon compound are 0.3 to 5 atoms / nm2 per unit area of ​​the silica particle. ２ The silica sol according to claim 1, wherein the silica sol is bonded in a ratio of:

3. 3. The silica sol according to claim 1, wherein the epoxy group is a glycidyl group or a 3,4-epoxycyclohexyl group.

4. 3. The silica sol according to claim 1, wherein the average primary particle diameter of the silica particles measured by a nitrogen gas adsorption method (BET method) is 5 to 100 nm, and the average particle diameter of the silica particles measured by a dynamic light scattering method (DLS method) is 5 to 200 nm.

5. 2. The silica sol according to claim 1, wherein the dispersion medium is an organic substance having a hydroxyl group, an organic substance having a carbonyl structure, or an organic substance having an epoxy group.

6. 6. The silica sol according to claim 5, wherein the organic substance having a hydroxyl group in the dispersion medium is methanol, ethanol, n-propanol, isopropanol, n-butanol, or propylene glycol monomethyl ether.

7. 6. The silica sol according to claim 5, wherein the organic substance having a carbonyl structure of the dispersion medium is methyl ethyl ketone, methyl isobutyl ketone, diisopropyl ketone, diisobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, or propylene glycol monomethyl ether acetate.

8. 6. The silica sol according to claim 5, wherein the organic substance having an epoxy group in the dispersion medium is a bisphenol A liquid epoxy compound, a bisphenol F liquid epoxy compound, or 3',4'-epoxycyclohexylmethyl 3',4'-epoxycyclohexane carboxylate.

9. The silica sol according to any one of claims 1, 2, and 5 to 8, which contains a basic substance, and the basic substance is an amine, ammonia, an inorganic alkali compound, or a quaternary ammonium compound.

10. The silica sol according to claim 9, wherein the amine is a secondary or tertiary amine having a total of 5 to 35 carbon atoms.

11. The silica particles may further comprise a compound represented by formula (1) to formula (3): 【Chemistry 1】 (In formula (1), R ３ each represents an alkyl group, a halogenated alkyl group, an alkenyl group, an aryl group, or an organic group having a (meth)acryloyl group, a mercapto group, an amino group, a ureido group, or a cyano group, and is bonded to a silicon atom by a Si-C bond; R ４ each represents an alkoxy group, an acyloxy group, or a halogen group; a represents an integer of 1 to 3; In formula (2) and formula (3), R ５ and R ７ are each an alkyl group having 1 to 3 carbon atoms or an aryl group having 6 to 30 carbon atoms and bonded to a silicon atom by a Si—C bond, R ６ and R ８ each represents an alkoxy group, an acyloxy group, or a halogen group; Y represents an alkylene group, an NH group, or an oxygen atom; b is an integer of 1 to 3; c is an integer of 0 or 1; and d is an integer of 1 to 3. The silica sol according to any one of claims 1, 2, and 5 to 8, comprising a hydrolysate of at least one silane compound selected from the group consisting of:

12. The silane compound according to claim 11 is represented by the above formula (1) (wherein R ３ is an organic group having an aryl group and bonded to a silicon atom by a Si-C bond, ４ Each of the formulas represents an alkoxy group, an acyloxy group, or a halogen group, and a represents an integer of 1 to 3. The silica sol according to any one of claims 1 to 8,

13. The silica particles of the dispersoid convert aluminum atoms into Al ２ O ３ Converted to 800 to 10,000 ppm / SiO ２ The silica sol according to any one of claims 1, 2, and 5 to 8, wherein the ratio of

14. The following steps (A) to (C): Step (A): Silica particles having an average particle size of 5 to 200 nm as determined by dynamic light scattering (DLS) are dissolved in alcohol R. １ OH (but R １ represents an organic group having 1 to 10 carbon atoms which may have an oxygen atom, and the silica sol has a water content of 5 mass % or less; Step (B): adjusting the pH of the silica sol obtained in step (A) to 6 to 8; Step (C): Adding an epoxy group or an epoxy group-containing organic group (R ２ 9. The method for producing a silica sol according to claim 1, 2, or 5 to 8, comprising the step of adding a silane compound having the formula (I) to coat the silica particles.

15. Further, step (D): Step (D): The dispersion medium of the silica sol obtained in step (C) is changed to alcohol R. １ The method for producing a silica sol according to claim 14, further comprising a step of substituting OH with an organic substance having a carbonyl structure or an organic substance having an epoxy group.

16. The method according to claim 14, wherein the step (C) further includes a step (C-1) of adding at least one silane compound selected from the group consisting of the formulas (1) to (3) to coat the silica particles.

17. The above-mentioned (D) step is a step in which the dispersion medium is an alcohol R １ The method according to claim 15, further comprising a step (D-1) of replacing OH with an organic substance having a carbonyl structure and then replacing it with an organic substance having an epoxy group.

18. A cured body-forming composition comprising the silica sol according to any one of claims 1, 2, or 5 to 8, and an amine-based curing agent, an acid anhydride-based curing agent, or an acid generator-based curing agent.

19. The cured body-forming composition according to claim 18, further comprising an epoxy resin.

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