JP5712846B2 - Dicarboxylic anhydride-dispersed sol of silane-modified metal oxide, method for producing the same, epoxy curing agent containing the same, and cured epoxy resin - Google Patents

Description

  The present invention relates to a sol in which modified high refractive index metal oxide colloidal particles are dispersed in a dicarboxylic acid anhydride, a method for producing the sol, an epoxy curing agent containing the sol, and an epoxy resin cured product using the epoxy curing agent.

  As a sealing resin composition used when sealing an optical semiconductor element such as a light emitting diode (LED), the cured body is required to have transparency, and in general, a bisphenol A type epoxy resin, Epoxy resin curing compositions obtained by using an epoxy resin such as an alicyclic epoxy resin or triglycidyl isocyanurate and an acid anhydride as a curing agent are widely used. However, when the epoxy resin curing composition is used as a sealing resin, due to shrinkage due to curing of the epoxy resin curing composition or distortion caused by the difference in linear expansion coefficient between the epoxy resin cured body and the optical semiconductor element, Internal stress is generated and the optical semiconductor element is deteriorated. Therefore, as a method for reducing the internal stress, it has been proposed to add an inorganic powder having a small linear expansion coefficient such as silica powder and an average particle diameter of 3 to 60 μm to the epoxy resin curing composition. A method has been proposed in which the refractive index is approximated to prevent a decrease in light transmittance of the obtained cured body (see Patent Document 1).

  Further, as a method for obtaining a colorless and transparent epoxy resin cured product, an epoxy resin curing composition including an epoxy resin, a curing agent, a curing accelerator, and inorganic oxide particles having an average primary particle size of 100 nm or less has been proposed ( Patent Document 2).

On the other hand, as one liquid agent of the two-pack type epoxy resin curing composition for improving the insulating properties of the cured epoxy resin, an inorganic filler containing a specific epoxy curing agent and spherical silica having an average particle diameter of 2 μm or less and curing It has been proposed to use a liquid containing an accelerator, and it is disclosed that the viscosity of the liquid is 25,000 to 33000 mPa · s at 25 ° C. (see Patent Document 3).
JP-A-11-74424 JP 2005-225964 A JP-A-11-71503

  When an epoxy resin curing composition containing silica particles is used as a resin composition for sealing an optical semiconductor element such as a light emitting diode (LED), the epoxy resin and silica are used when the average particle diameter of the silica particles is 3 to 60 μm. Even if the refractive index of the particles is approximated, the light transmittance of the obtained cured product is not sufficient. In addition, when inorganic oxide particles dispersed in an organic solvent having an average primary particle size of 100 nm or less are blended in an epoxy resin curing composition and the solvent is removed under a condition in which the curing reaction does not proceed, the solvent removal becomes incomplete and curing occurs. Solvent may remain on the body. Further, when the amount of spherical silica having an average particle diameter of 2 μm or less in the inorganic filler is a certain amount or more, the viscosity of the liquid agent is increased and casting workability may be lowered.

  An object of the present invention is a modified high refractive index colloidal particle having a high refractive index and a high transparency, which is suitable for a curing agent for an epoxy resin curing composition that can be used in a resin composition for sealing an optical semiconductor element. Provides a sol dispersed in a liquid dicarboxylic acid anhydride at 30 ° C., an epoxy curing agent containing the sol, and an epoxy resin cured product using the curing agent.

The first aspect of the present invention is a modified metal oxide colloidal particle having a metal oxide colloidal particle as a nucleus and an outer surface thereof coated with a composite oxide colloidal particle, which is a primary particle of 5 to 60 nm. The core is made of oxide colloidal particles (A) of at least one metal selected from the group consisting of Ti, Fe, Zr, Sn, Ta, Nb, Y, Mo, W, Pb, In, Bi, and Sr. And the outer surface is M / (SnO ₂ + SiO ₂ ) where the mass ratio of silicon dioxide / stannic oxide is 0.1 to 5.0 and 0.001 to 0.08 (where M is an amine compound) Modified metal oxide colloidal particles (C) coated with silicon dioxide-stannic oxide composite oxide colloidal particles (B) having a primary particle diameter of 1 to 4 nm by binding an amine compound at a molar ratio of ) And The mass ratio (B) / (A) of the composite oxide colloidal particles (B) to the oxide colloidal particles (A) of the genus is 0.05 to 0.50, and on the particle surface of the colloidal particles (C) A sol in which a silane-treated modified metal oxide colloidal particle having a surface area of 1 nm ² bonded with 1 to 4 silyl groups is dispersed in a liquid dicarboxylic acid anhydride at 30 ° C .;
As a second aspect, the silyl group is represented by the following general formula (I):
-Si (R ¹ ) _a (X) _3-a (I)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A represents an integer of 0 to 3.) A sol in which the silane-treated modified metal oxide colloidal particles according to the first aspect represented by the formula (1) are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C.,
As a third aspect, the silane-treated modified metal oxide colloidal particle according to the first aspect is 30 ° C., wherein the amine compound is at least one compound selected from the group consisting of a primary amine, a secondary amine, and a tertiary amine. A sol dispersed in a liquid dicarboxylic acid anhydride,
As a fourth aspect, the dicarboxylic anhydride is at least one selected from the group consisting of methylhexahydrophthalic anhydride, hydrogenated methylnadic acid anhydride, and hydrogenated trimellitic anhydride. A sol in which the silane-treated modified metal oxide colloidal particles according to any one of 3 are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C.,
As a fifth aspect, the silane-treated modified metal oxide colloidal particles according to any one of the first to fourth aspects containing the silane-treated modified metal oxide colloidal particles at 5 to 70% by mass are liquid at 30 ° C. A sol dispersed in a dicarboxylic acid anhydride of
As a sixth aspect, an epoxy curing agent comprising a sol in which the silane-treated modified metal oxide colloidal particles according to any one of the first to fifth aspects are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C.,
As a seventh aspect, the epoxy curing agent according to the sixth aspect containing 0.01 to 50 parts by mass of a non-alcoholic organic solvent with respect to 100 parts by mass of the silane-treated modified metal oxide colloidal particles,
As an eighth aspect, an epoxy resin curing composition comprising the epoxy curing agent according to the sixth aspect or the seventh aspect and an epoxy resin,
As a ninth aspect, the epoxy resin curing composition according to the eighth aspect, further comprising a curing accelerator,
As a tenth aspect, the epoxy resin curing agent according to the ninth aspect, wherein the epoxy curing agent contains 50 to 500 parts by mass and the curing accelerator contains 0.1 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin. Composition,
As an eleventh aspect, an epoxy resin cured body using the epoxy resin curing agent according to the sixth aspect or the seventh aspect,
As a twelfth aspect, any of the first to fifth aspects including the following steps (a), (b), (c), (d), (e), (f), (g), and (h) A method for producing a sol in which the silane-treated modified metal oxide colloidal particles according to claim 1 are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C .:
Step (a): An aqueous solution containing alkali stannate and alkali silicate in a mass ratio of silicon dioxide / stannic oxide in a ratio of 0.1 to 5 is prepared, and then cations present in the aqueous solution are removed. An aqueous sol of silicon dioxide-stannic oxide composite colloidal particles having a primary particle size of 1 to 4 nm is prepared, and M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound). ) Is added in an amount such that the molar ratio of 0.1 to 1.0 is such that the mass ratio of silicon dioxide / stannic oxide is 0.1 to 5.0 and 0.1 to 1 0.02 M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) a silicon dioxide-stannic oxide composite having a primary particle size of 1-4 nm stabilized with an amine compound present in a molar ratio Aqueous solution of oxide colloidal particles (B ') A process of obtaining
(B) Step: at least one metal selected from the group consisting of Ti, Fe, Zr, Sn, Ta, Nb, Y, Mo, W, Pb, In, Bi and Sr having a primary particle size of 5 to 60 nm The aqueous sol of the oxide colloidal particles (A) and the aqueous sol obtained in the step (a) are used as the silicon dioxide-stannic oxide composite oxide colloidal particles for the metal oxide colloidal particles (A) ( B ′) is mixed in such an amount that the mass ratio (B ′) / (A) is 0.05 to 0.50, whereby the metal oxide colloidal particles (A) are converted into the silicon dioxide-stannic oxide. Obtaining an aqueous sol of modified metal oxide colloidal particles (C ′) coated with the composite oxide colloidal particles (B ′);
(C) step: a step of cation-exchange the aqueous sol of the modified metal oxide colloidal particles (C ′) obtained in the step (b) and removing the amine compound added in the step (a),
Step (d): In the aqueous sol obtained in Step (c), M / (SnO ₂ + SiO ₂ ) (as the molar ratio of the amine compound to the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′)) Where M represents an amine compound) by adding an amount of an amine compound in an amount of 0.001 to 0.08, and the outer surface of the metal oxide colloidal particles (A) is made of silicon dioxide / The amine compound has a molar ratio of M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) in which the mass ratio of stannic oxide is 0.1 to 5.0 and 0.001 to 0.08. A colloidal particle (C) formed by coating with a bonded silicon dioxide-stannic oxide composite oxide colloidal particle (B) having a primary particle diameter of 1 to 4 nm, and a colloidal particle of the metal oxide ( Said dioxide for A) Obtaining an aqueous sol of modified metal oxide colloidal particles (C) having a mass ratio (B) / (A) of the silicon-stannic oxide composite oxide colloidal particles (B) of 0.05 to 0.50,
(E) Step: A step of replacing the dispersion medium of the aqueous sol obtained in the step (d) with an alcoholic organic solvent,
Step (f): The alcoholic organic solvent sol obtained in Step (e) is added to the following general formula (II):
Si (R ¹ ) _a (X) _4-a (II)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A represents an integer of 0 to 3), and the mass ratio of the organosilane compound and / or the hydrolyzate thereof to the modified metal oxide colloidal particles (C) is 0.01 to 0. .50 to give a general formula (I)
-Si (R ¹ ) _a (X) _3-a (I)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A represents an integer of 0 to 3), and a step of binding the silyl group represented by the surface of the modified metal oxide colloidal particles (C);
(G) Step: replacing the dispersion medium of the alcoholic organic solvent sol of the silane-treated modified metal oxide colloidal particles obtained in the step (f) with a non-alcohol organic solvent;
(H) Step: A step of replacing the dispersion medium of the non-alcohol organic solvent dispersion sol of the silane-treated modified metal oxide colloidal particles obtained in the step (g) with a liquid dicarboxylic anhydride at 30 ° C.

The sol of the present invention is a modified metal oxide colloidal particle having a metal oxide colloidal particle as a nucleus and an outer surface coated with a composite oxide colloidal particle, and having a primary particle diameter of 5 to 60 nm. Fe, Zr, Sn, Ta, Nb, Y, Mo, W, Pb, In, Bi, and Sr. The outer surface of the oxide colloidal particle (A) of at least one metal selected from the group consisting of M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) in which the mass ratio of silicon dioxide / stannic oxide is 0.1 to 5.0 and 0.001 to 0.08. A modified metal oxide colloidal particle (C) formed by coating with a silicon dioxide-stannic oxide composite oxide colloidal particle (B) having an amine compound bonded in a ratio and having a primary particle diameter of 1 to 4 nm, And metal oxide co Weight ratio of the composite oxide colloidal particles (B) for id particles (A) (B) / ( A) is 0.05 to 0.50, and its surface area 1 nm ² on the particle surfaces of the colloidal particles (C) This is a sol in which silane-treated modified metal oxide colloidal particles, each having 1 to 4 silyl groups bonded to each other, are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C.

  By using the sol of the present invention as an epoxy curing agent, the nano-sized silane-treated modified metal oxide colloidal particles can be efficiently introduced into the cured epoxy resin. Even if the metal oxide colloidal particles cannot be directly dispersed in the epoxy resin because the epoxy resin is a solid or highly viscous liquid, the silane-treated modified metal oxide colloidal particles are dispersed in the epoxy curing agent. Therefore, the silane-treated modified metal oxide colloidal particles can be easily dispersed at a high filling rate in the cured epoxy resin.

  Moreover, since the epoxy curing agent of the present invention has extremely high transparency, even if the metal oxide component as a filler is contained at a high concentration, the transparency of the resulting cured epoxy resin is not impaired. The epoxy curing agent of the present invention can arbitrarily adjust the refractive index by appropriately adjusting the content of the silane-treated modified metal oxide colloidal particles. For this reason, it is extremely useful as an epoxy curing agent for an epoxy resin curing composition used for a resin composition for sealing an optical semiconductor element such as an LED.

The sol of the present invention is a modified metal oxide colloidal particle having a metal oxide colloidal particle as a nucleus and an outer surface coated with a composite oxide colloidal particle, and having a primary particle diameter of 5 to 60 nm. Fe, Zr, Sn, Ta, Nb, Y, Mo, W, Pb, In, Bi, and Sr. The outer surface of the oxide colloidal particle (A) of at least one metal selected from the group consisting of M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) in which the mass ratio of silicon dioxide / stannic oxide is 0.1 to 5.0 and 0.001 to 0.08. A modified metal oxide colloidal particle (C) formed by coating with a silicon dioxide-stannic oxide composite oxide colloidal particle (B) having an amine compound bonded in a ratio and having a primary particle diameter of 1 to 4 nm, And metal oxide co Weight ratio of the composite oxide colloidal particles (B) for id particles (A) (B) / ( A) is 0.05 to 0.50, and its surface area 1 nm ² on the particle surfaces of the colloidal particles (C) This is a sol in which silane-treated modified metal oxide colloidal particles, each having 1 to 4 silyl groups bonded to each other, are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C.

  The concentration of the silane-treated modified metal oxide colloidal particles contained in the sol of the present invention is 5 to 70% by mass, preferably 10 to 60% by mass.

  Ti, Fe, Zr, Sn, Ta, Nb, Y, Mo, W, Pb, In, having a primary particle diameter of 5 to 60 nm, which is the core of the silane-treated modified metal oxide colloidal particles contained in the sol of the present invention, The oxide colloidal particles (A) of at least one metal selected from the group consisting of Bi and Sr can be produced by a known method such as an ion exchange method, a peptization method, a hydrolysis method, or a reaction method. .

  Examples of the ion exchange method include a method of treating the acid salt of the metal with a hydrogen ion exchange resin or a method of treating the basic salt of the metal with a hydroxyl type anion exchange resin.

  Examples of the peptization method include neutralizing the acidic salt of the metal with a base, or washing the gel obtained by neutralizing the basic salt of the metal with an acid, and then peptizing with an acid or a base. The method of doing is mentioned.

  Examples of the hydrolysis method include a method of hydrolyzing the alkoxide of the metal, or a method of removing an unnecessary acid after hydrolyzing the basic salt of the metal.

  An example of the reaction method is a method of reacting the metal powder with an acid.

The oxide colloidal particles (A) is an oxide of a metal of valence 2-6, as they form, for example _{TiO 2, Fe 2 O 3,} ZrO 2, SnO 2, Ta 2 O 5, Nb ₂ O ₅ , Y ₂ O ₃ , MoO ₃ , WO ₃ , PbO, In ₂ O ₃ Bi ₂ O ₃ , SrO and the like can be exemplified. These metal oxides can be used alone or in combination. Examples of the combination include a method of mixing several kinds of the metal oxides, a method of combining the metal oxides, and a method of solidifying the metal oxides at the atomic level.

For example, SnO ₂ —WO ₃ composite colloidal particles in which SnO ₂ particles and WO ₃ particles are chemically combined at the interface to form a composite, and SnO ₂ particles and ZrO ₂ particles form a chemical bond at the interface. And composite SnO ₂ —ZrO ₂ composite colloidal particles, and TiO ₂ —ZrO ₂ —SnO ₂ composite colloidal particles obtained by forming a solid solution of TiO ₂ , ZrO ₂ and SnO ₂ at the atomic level. .

The oxide colloidal particles (A) can also be used as a compound by a combination of metal components, and examples thereof include TiSrO ₃ and TiBaO ₃ .

  In the present invention, the aqueous sol of the metal oxide colloidal particles (A) serving as a nucleus in the present invention may have a pH of 5 to 11.5, preferably a pH of 7 to 11.5. The pH of the aqueous sol can be adjusted with an alkali component as necessary. Examples of the alkali component used include alkali metal hydroxides such as lithium, sodium and potassium, and alkaline earth metals such as calcium, magnesium and strontium. Hydroxide, ammonia, ethylamine, triethylamine, isopropylamine, alkylamines such as n-propylamine, aralkylamines such as benzylamine, alicyclic amines such as piperidine, alkanolamines such as monoethanolamine and triethanolamine, A quaternary ammonium hydroxide etc. are mentioned.

In the present invention, at least one selected from the group consisting of Ti, Fe, Zr, Sn, Ta, Nb, Y, Mo, W, Pb, In, Bi, and Sr having a primary particle diameter of 5 to 60 nm serving as a nucleus in the present invention. M / (SnO ₂ + SiO ₂ ) covering the metal oxide colloidal particles (A) and having a mass ratio of silicon dioxide / stannic oxide of 0.1 to 5.0 and 0.001 to 0.08 The silicon dioxide-stannic oxide composite oxide colloidal particles (B) having a primary particle diameter of 1 to 4 nm in which the amine compound is bonded at a molar ratio of M (wherein M represents an amine compound) are used as a precursor thereof. / Mass ratio of stannic oxide is 0.1 to 5.0 and exists in a molar ratio of M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) of 0.1 to 1.0. 1 to 4 nm stabilized with an amine compound An aqueous sol of silicon dioxide-stannic oxide composite oxide colloidal particles (B ′) having a primary particle size is prepared, and the aqueous sol is added to the aqueous sol of the metal oxide colloidal particles (A), After the surface of the metal oxide colloidal particles (A) is coated with the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′), the amine compound for stabilization is removed by cation exchange, Subsequently, an amine compound in an amount suitable for stabilization of the modified metal oxide colloidal particles (C) is bonded to the surface thereof. The amount of the amine compound suitable for stabilizing the modified metal oxide colloidal particles (C) is 0.001 to 0.08 as a molar ratio of M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound). Is the amount. When the amount of the amine compound bound to the silicon dioxide-stannic oxide composite oxide colloidal particles (B) is less than 0.001 as the molar ratio of M / (SnO ₂ + SiO ₂ ), the silane treatment of the present invention is performed. This is not preferable because the dispersion stability of the alcoholic organic solvent-dispersed sol prepared in the course of producing a sol in which the modified metal oxide colloidal particles are dispersed in a liquid dicarboxylic anhydride at 30 ° C. is insufficient. Further, when the molar ratio of M / (SnO ₂ + SiO ₂ ) exceeds 0.08, it is represented by the general formula (I) bonded to the particle surface of the modified metal oxide colloidal particles (C). This is not preferable because it prevents the bonding of silyl groups.

  The silicon dioxide-stannic oxide composite oxide colloidal particles (B ') can be obtained by using the following known methods (for example, Japanese Patent Publication No. 50-40119). That is, a silicon dioxide-stannic oxide composite colloid having a primary particle size of 1 to 4 nm by mixing an alkali silicate aqueous solution or silicate sol solution and an alkali stannate aqueous solution and then removing the cation with a cation exchange resin. By producing particles and then adding and mixing the amine compound, an aqueous sol of colloidal particles of silicon dioxide-stannic oxide composite stabilized by the amine compound can be obtained.

  The amine compound in the aqueous sol of silicon dioxide-stannic oxide composite oxide colloidal particles (B ′) having a primary particle diameter of 1 to 4 nm stabilized with the amine compound is a silicon dioxide-stannic oxide composite. Presumed to maintain the dispersion stability of the colloidal particles (B ′) by being dissolved in the dispersion medium of the aqueous sol in addition to those adsorbed on the surface of the oxide colloidal particles (B ′). Is done.

A silicon dioxide-stannic oxide composite having a primary particle diameter of 1 to 4 nm obtained by mixing the alkali silicate aqueous solution or the silicate sol solution and the alkali stannate aqueous solution and then removing the cation with a cation exchange resin. The aqueous sol of colloidal particles loses stability when left for several hours and gels when no amine compound is added or when an amine compound having a molar ratio of M / (SnO ₂ + SiO ₂ ) of less than 0.1 is added. Therefore, it cannot be used. The addition of an amine compound having a molar ratio of M / (SnO ₂ + SiO ₂ ) of 0.1 to 1.0 (where M is an amine compound) is performed by adding the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′ ) Is sufficient to maintain the dispersion stability of the aqueous sol. Even if the molar ratio of M / (SnO ₂ + SiO ₂ ) exceeds 1.0, the amine compound is present in excess, which is not efficient.

  As the alkali silicate aqueous solution, sodium silicate and potassium silicate can be used, and as the silicate sol liquid, active silicic acid obtained by cation exchange of these alkali silicate aqueous solutions can be used. As the alkali stannate aqueous solution, a sodium stannate aqueous solution can be preferably used.

  The amine compound used in the present invention is at least one selected from the group consisting of primary amines, secondary amines and tertiary amines. Primary amines include methylamine, ethylamine, propylamine, isopropylamine, butylamine, isobutylamine, amylamine, allylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dodecylamine, cyclopropylamine, cyclobutylamine, cyclopentylamine And cyclohexylamine. Secondary amines include dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, N-ethyl-1,2-dimethylpropylamine, diamylamine and diallylamine. Tertiary amines include trimethylamine, triethylamine, tripropylamine, tributylamine, triamylamine and triallylamine.

The modified metal oxide colloidal particles (C) have the metal oxide colloidal particles (A) as nuclei and the outer surface thereof having a mass ratio of silicon dioxide / stannic oxide of 0.1 to 5.0. Silicon dioxide in which the amine compound is bonded and has a primary particle size of 1 to 4 nm in a molar ratio of M / (SnO ₂ + SiO ₂ ) (wherein M represents an amine compound) of 0.001 to 0.08 It is formed by coating with stannic oxide composite oxide colloidal particles (B).

The modified metal oxide colloidal particles (C) have an aqueous sol of the metal oxide colloidal particles (A) used as nuclei and a mass ratio of silicon dioxide / stannic oxide of 0.1 to 5.0. And a silicon dioxide-secondary oxide having a primary particle size of 1-4 nm stabilized with an amine compound having a molar ratio of 0.1 / 1.0 M / (SnO ₂ + SiO ₂ ), where M is an amine compound. An aqueous sol of tin composite oxide colloidal particles (B ′) is mixed to 0.05 to 0.50 in a mass ratio (B ′) / (A) converted to a metal oxide to modify the modified metal oxide. After obtaining an aqueous sol of the product colloidal particles (C ′), the amine compound is removed from the aqueous sol by cation exchange, and further the amine for the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′). M / (SnO ₂ + Si as the molar ratio of the compound O ₂ ) is obtained by adding an amount of an amine compound in which 0.001 to 0.08 (where M is an amine compound).

  The aqueous sol of the modified metal oxide colloidal particles (C) can contain other optional components as long as the object of the present invention is achieved. In particular, when oxycarboxylic acids are contained in an amount of about 10% by weight or less based on the total amount of all metal oxides, colloidal particles with further improved performance such as dispersibility can be obtained.

  Examples of the oxycarboxylic acid used include lactic acid, tartaric acid, malic acid, citric acid, gluconic acid and the like. Moreover, an alkali component can be contained, for example, hydroxides of alkali metals such as lithium, sodium, potassium, rubidium, and cesium, ammonia, and the like can also be contained. These can also be used in combination with the oxycarboxylic acid.

  The aqueous sol of the modified metal oxide colloidal particles (C) is concentrated to about 50% by mass as the total amount of all metal oxides of the modified metal oxide colloidal particles (C) by, for example, evaporation method, ultrafiltration method or the like. be able to.

The silane-treated modified metal oxide colloidal particles contained in the sol of the present invention have the following general formula (I) on the particle surface of the modified metal oxide colloidal particles (C).
-Si (R ¹ ) _a (X) _3-a (I)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A represents an integer of 0 to ^3. ) It is preferable that 0.1 to 4 silyl groups each having a surface area of 1 nm ² are bonded.

The number of silyl groups per 1 nm ² of surface area of the modified metal oxide colloidal particles (C) can be measured using ICP emission spectroscopic analysis or CHN elemental analysis. The specific surface area of the silane-treated modified metal oxide colloidal particles can be measured by a nitrogen adsorption method.

  The silyl group represented by the general formula (I) bonded to the surface of the modified metal oxide colloidal particle (C) is an organosilane compound represented by the following general formula (II). It can be bonded by reacting with the surface of the particles (C).

(R ¹ ) _a Si (X) _4-a (II)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A represents an integer of 0 to 3)
Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, hexyl, tert-butyl, sec-butyl, decyl, dodecyl, octadecyl and the like.

  Examples of the aryl group include a phenyl group and a naphthyl group. A phenyl group is preferred.

In the general formula (II), X is a hydroxyl group or a hydrolyzable group, and is an alkoxy group having 1 to 4 carbon atoms. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. a represents an integer of 0 to 3. When R ¹ or X there are a plurality, the plurality of R ¹ or X may be the same or different, respectively. a is preferably 1 or 2, particularly preferably 1.

The substituent contained in R ¹ is not particularly limited, but is a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl, ethyl, isopropyl, propyl). , T-butyl etc.), aryl groups (phenyl, naphthyl etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl etc.), alkoxy groups (methoxy, ethoxy, isopropoxy etc.), aryloxy (phenoxy etc.), Alkenyl groups (vinyl, 1-propenyl, etc.), acyloxy groups (acetoxy, acryloyloxy, methacryloyloxy, etc.), alkoxycarbonyl groups (methoxycarbonyl, ethoxycarbonyl, etc.), aryloxycarbonyl groups (phenoxycarbonyl, etc.), carbamoyl groups (carbamoyl) N-methylcal Moil, etc.), an acylamino group (an acetylamino, benzoylamino, acrylamino, methacrylamino etc.). These substituents may be further substituted.

When there are a plurality of R ^{1 s} , at least one is preferably a substituted alkyl group or a substituted aryl group.

  Examples of the organosilicon compound represented by the general formula (II) include tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetraisopropoxysilane, tetra n-butoxysilane, tetraacetoxysilane, and methyltrimethoxysilane. , Methyltriethoxysilane, methyltripropoxysilane, methyltriacetoxysilane, methyltributoxysilane, methyltripropoxysilane, methyltriamyloxysilane, methyltriphenoxysilane, methyltribenzyloxysilane, methyltriphenethyloxysilane, glycine Sidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxye Rutrimethoxysilane, β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyl Triethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxysilane, γ-glycidoxypropyl Triphenoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane, β-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyl Triethoxysilane, δ -Glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, (3,4-epoxycyclohexyl) methyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltriethoxysilane, β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltripropoxysilane, β- (3,4-epoxycyclohexyl) Ethyltributoxysilane, β- (3,4-epoxycyclohexyl) ethyltriphenoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltriethoxysilane, δ- (3,4 Poxycyclohexyl) butyltrimethoxysilane, δ- (3,4-epoxycyclohexyl) butyltriethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylethyldimethoxysilane, α-glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane Silane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ- Lysidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane Γ-glycidoxypropyl vinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, phenyltrimethoxy Silane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, 3, 3,3-trifluoropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, β-cyanoethyltriethoxysilane, chloromethyltrimethoxysilane, chloro Methyltriethoxysilane, N- (β-aminoethyl) γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, N- (β- Aminoethyl) γ-aminopropyltriethoxysilane, N- (β-aminoethyl) γ-aminopropylmethyldiethoxysilane, dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyl Ethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxy Silane, (gamma) -mercaptomethyldiethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, etc. are mentioned, These can be used individually or in combination of 2 or more types.

In addition, the hydrolyzate of the organosilane compound of the general formula (II) is a compound in which a part or all of R ¹ and X in the formula are replaced with hydrogen atoms. These hydrolysates of organosilane compounds of general formula (II) can be used alone or in combination of two or more.

  Hydrolysis of the organic silane compound is carried out by adding water or an acidic aqueous solution of a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution or an acetic acid aqueous solution to the organic silane compound and stirring them.

  In this invention, it is preferable to use at least 1 sort (s) chosen from the group which consists of a compound represented with general formula (II), and its hydrolyzate as an organosilane compound. In particular, methyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, methacryloxypropyltrimethoxysilane and / or a hydrolyzate thereof are preferable.

  In a sol in which the silane-treated modified metal oxide colloidal particles of the present invention are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C., the liquid state at 30 ° C. means a liquid state at an atmospheric pressure of 30 ° C. .

  The liquid dicarboxylic acid anhydride used at 30 ° C is methyltetrahydrophthalic acid anhydride, methylhexahydrophthalic acid anhydride, methyl nadic acid anhydride, hydrogenated methyl nadic acid anhydride, hydrogenated trimellitic acid anhydride. , Trialkylhydrophthalic anhydride, dodecenyl succinic anhydride and the like. Among these, methylhexahydrophthalic anhydride, hydrogenated methylnadic acid anhydride, or hydrogenated trimellitic anhydride is preferable from the viewpoint of heat resistance, light resistance, and colorless transparency.

  In the sol in which the silane-treated modified metal oxide colloidal particles of the present invention are dispersed in a liquid dicarboxylic anhydride at 30 ° C., the concentration of the silane-treated modified metal oxide colloidal particles is preferably 5 to 70% by mass. Is 10-60 mass%.

  Further, the B-type viscosity of the sol at 30 ° C. is 30 to 200000 mPa · s, preferably 30 to 50000 mPa · s, and more preferably 30 to 5000 mPa · s.

  The sol is excellent in transparency, and the light transmittance with an optical path length of 10 mm at a wavelength of 500 nm when the concentration of the silane-treated modified metal oxide colloidal particles (D) in the sol is adjusted to 10% by mass is 30. % Or more, preferably 40%.

  The present invention is characterized in that a sol in which the silane-treated modified metal oxide colloidal particles are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C. is used as an epoxy curing agent.

  The silane-treated modified metal oxide colloidal particles contained in the epoxy curing agent of the present invention is 5 to 70% by mass.

  The epoxy curing agent of the present invention is highly transparent and has a high refractive index. The refractive index of the epoxy curing agent is 1.48 to 1.65.

  Further, the epoxy curing agent of the present invention may contain a small amount of a non-alcoholic organic solvent for the purpose of viscosity adjustment, etc., and the allowable content range is the silane treatment modification contained in the epoxy curing agent of the present invention. It is 0.01-50 mass parts as a non-alcoholic organic solvent with respect to 100 mass parts of metal oxide colloidal particles, Preferably it is 0.01-10 mass parts.

  The epoxy curing agent of the present invention can be blended with an epoxy resin to form an epoxy resin curing composition.

  The epoxy resin used in the epoxy resin hardened composition of the present invention is not particularly limited, but specific examples 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-cyclohexane Dicarboxylic acid diglycidyl ester, 4,4′-methylenebis (N, N-diglycidylaniline), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, trimethylolethane triglycidyl ether, triglycidyl-p -A Nophenol, tetraglycidylmetaxylenediamine, tetraglycidyldiaminodiphenylmethane, tetraglycidyl-1,3-bisaminomethylcyclohexane, bisphenol-A-diglycidyl ether, bisphenol-S-diglycidyl ether, pentaerythritol tetraglycidyl ether resorcinol diglycidyl Ether, diglycidyl phthalate, 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-epoxy (Lopyl) isocyanurate, 1- {2,3-di (propionyloxy)}-3,5-bis (2,3-epoxypropyl) -1,3,5-triazine-2,4,6 · (1H, 3H, 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, resorcin diglycidyl ether, 1,6-hexane Diol diglycidyl ether, polyethylene glycol diglycidyl ether, phenyl glycidyl ether, p-tertiary butyl phenyl glycidyl ether, adipic acid diglycidyl ether, o-phthalic acid diglycidyl ether, dibromophenyl glycidyl ether, 1,2,7,8 -Diepoxyoctane, 1,6-dimethylol perfluorohexane diglycidyl ether, 4,4'-bis (2,3-epoxypropoxyperfluoroisopropyl) diphenyl ether, 2,2-bis (4-glycidyloxyphenyl) propane 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexyloxirane, 2- (3,4-epoxycyclohexyl)- ', 4'-epoxy-1,3-dioxane-5-spirocyclohexane, 1,2-ethylenedioxy-bis (3,4-epoxycyclohexylmethane), 4', 5'-epoxy-2'-methylcyclohexyl Methyl-4,5-epoxy-2-methylcyclohexanecarboxylate, ethylene glycol-bis (3,4-epoxycyclohexanecarboxylate), bis- (3,4-epoxycyclohexylmethyl) adipate, bis (2,3-epoxy And cyclopentyl) ether. Among them, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 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, 3H, 5H) -trione, 1,3-bis (2,3-di (propionyloxy))-5- (2,3-epoxypropyl) 1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione, and mixtures thereof Etc. are preferably used.

  In the epoxy resin curing composition of the present invention, the epoxy curing agent of the present invention is preferably 50 to 500 parts by mass with respect to 100 parts by mass of the epoxy resin.

  Further, the epoxy resin curing composition of the present invention may appropriately contain a curing accelerator. Examples of curing accelerators include imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole; amines such as 2,4,6-tris (dimethylaminomethyl) phenol and benzyldimethylamine; triphenylphosphine Organic phosphorus compounds such as tributylphosphine; triphenylmonoalkylphosphonium halides such as triphenylethylphosphonium bromide; quaternary phosphonium salts such as tetrabutylphosphonium O, O′-diethyldithiophosphate; It is done. Among them, triphenylethylphosphonium bromide, tetrabutylphosphonium O, O′-diethyldithiophosphate, 2-ethyl-4-methylimidazole and the like are preferable as a curing accelerator.

  The epoxy resin curing composition of the present invention preferably contains 0.1 to 10 parts by mass of a curing accelerator.

  The epoxy curing agent of the present invention is blended with the epoxy resin and prepared as an epoxy resin curing composition, and the resulting epoxy resin curing composition is heated to become the cured epoxy resin of the present invention.

  When the epoxy curing agent of the present invention and the epoxy resin are mixed, the mixing method is not particularly limited, but it is preferably performed with stirring so that the epoxy curing agent and the epoxy resin are uniformly mixed. When uniform mixing is difficult due to the high viscosity of the epoxy resin curing composition containing the epoxy curing agent of the present invention and the epoxy resin, heating is performed so that the curing reaction of the curing composition does not proceed. By doing so, the viscosity of the curable composition can be reduced and workability can be improved.

  Moreover, when the non-alcoholic organic solvent is contained in the epoxy curing agent of the present invention, the obtained epoxy resin curing composition also contains the non-alcoholic organic solvent. It is preferable to remove the non-alcoholic organic solvent by a method such as heat treatment.

  The curing treatment of the epoxy resin curing composition is performed using an apparatus such as an oven at a temperature of 100 to 200 ° C., preferably 120 to 180 ° C., for 2 to 8 hours, preferably 3 to 6 hours.

  The cured epoxy resin of the present invention contains a silane-treated surface-modified metal oxide colloidal particle in the epoxy curing agent used, has high transparency, and has a high refractive index. Have a high refractive index and transparency.

  In addition, the cured epoxy resin of the present invention has a low coefficient of linear expansion and high bending strength and bending elastic modulus.

The sol in which the silane-treated modified metal oxide colloidal particles of the present invention are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C. has the following (a), (b), (c), (d), (e), (F), (g), and (h) It can manufacture by the method containing process.
The silane according to any one of claims 1 to 5, comprising the following steps (a), (b), (c), (d), (e), (f), (g) and (h). Method for producing sol in which treated modified metal oxide colloidal particles are dispersed in liquid dicarboxylic anhydride at 30 ° C .:
Step (a): An aqueous solution containing alkali stannate and alkali silicate in a mass ratio of silicon dioxide / stannic oxide in a ratio of 0.1 to 5 is prepared, and then cations present in the aqueous solution are removed. An aqueous sol of silicon dioxide-stannic oxide composite colloidal particles having a primary particle size of 1 to 4 nm is prepared, and M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound). ) Is added in an amount such that the molar ratio of 0.1 to 1.0 is such that the mass ratio of silicon dioxide / stannic oxide is 0.1 to 5.0 and 0.1 to 1 0.02 M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) a silicon dioxide-stannic oxide composite having a primary particle size of 1-4 nm stabilized with an amine compound present in a molar ratio Aqueous solution of oxide colloidal particles (B ') A process of obtaining
(B) Step: at least one metal selected from the group consisting of Ti, Fe, Zr, Sn, Ta, Nb, Y, Mo, W, Pb, In, Bi and Sr having a primary particle size of 5 to 60 nm The aqueous sol of the oxide colloidal particles (A) and the aqueous sol obtained in the step (a) are used as the silicon dioxide-stannic oxide composite oxide colloidal particles for the metal oxide colloidal particles (A) ( B ′) is mixed in such an amount that the mass ratio (B ′) / (A) is 0.05 to 0.50, whereby the metal oxide colloidal particles (A) are converted into the silicon dioxide-stannic oxide. Obtaining an aqueous sol of modified metal oxide colloidal particles (C ′) coated with the composite oxide colloidal particles (B ′);
(C) step: a step of cation-exchange the aqueous sol of the modified metal oxide colloidal particles (C ′) obtained in the step (b) and removing the amine compound added in the step (a),
Step (d): In the aqueous sol obtained in Step (c), M / (SnO ₂ + SiO ₂ ) (as the molar ratio of the amine compound to the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′)) Where M represents an amine compound) by adding an amount of an amine compound in an amount of 0.001 to 0.08, and the outer surface of the metal oxide colloidal particles (A) is made of silicon dioxide / The amine compound has a molar ratio of M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) in which the mass ratio of stannic oxide is 0.1 to 5.0 and 0.001 to 0.08. A colloidal particle (C) formed by coating with a bonded silicon dioxide-stannic oxide composite oxide colloidal particle (B) having a primary particle diameter of 1 to 4 nm, and a colloidal particle of the metal oxide ( Said dioxide for A) Obtaining an aqueous sol of modified metal oxide colloidal particles (C) having a mass ratio (B) / (A) of the silicon-stannic oxide composite oxide colloidal particles (B) of 0.05 to 0.50,
(E) Step: A step of replacing the dispersion medium of the aqueous sol obtained in the step (d) with an alcoholic organic solvent,
Step (f): The alcoholic organic solvent sol obtained in Step (e) is added to the following general formula (II):
Si (R ¹ ) _a (X) _4-a (II)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A represents an integer of 0 to 3), and the mass ratio of the organosilane compound and / or the hydrolyzate thereof to the modified metal oxide colloidal particles (C) is 0.01 to 0. .50 to give a general formula (I)
-Si (R ¹ ) _a (X) _3-a (I)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A represents an integer of 0 to 3), and a step of binding the silyl group represented by the surface of the modified metal oxide colloidal particles (C);
(G) Step: replacing the dispersion medium of the alcoholic organic solvent sol of the silane-treated modified metal oxide colloidal particles obtained in the step (f) with a non-alcohol organic solvent;
(H) Step: A step of replacing the dispersion medium of the non-alcohol organic solvent dispersion sol of the silane-treated modified metal oxide colloidal particles obtained in the step (g) with a liquid dicarboxylic anhydride at 30 ° C.

  In step (a), sodium stannate or potassium stannate can be used as the alkali stannate, and sodium stannate is preferred.

  As the silicate alkali, sodium silicate and potassium silicate can be used.

  Alkali stannate and alkali silicate are prepared as an aqueous solution containing silicon dioxide / stannic oxide at a mass ratio of 0.1 to 5, and then the cation present in the aqueous solution is converted to a cation exchange resin. Remove.

The alkali stannate and the alkali silicate are prepared by being measured so that the mass ratio of silicon dioxide / stannic oxide is 0.1 to 5.0 and dissolved in water. A preferable solid content concentration of the aqueous solution is 1 to 12% by mass as (SnO ₂ + SiO ₂ ).

  Cations are removed from the prepared aqueous solution using a cation exchange resin. The cation exchange resin is preferably a hydrogen-type strongly acidic cation exchange resin. For example, Amberlite (registered trademark) 120B can be packed in a column and used. By performing this cation exchange, the silicic acid component and the stannic acid component are polymerized to produce silicon dioxide-stannic oxide composite colloidal particles having a primary particle diameter of 1 to 4 nm.

This colloidal particle of silicon dioxide-stannic oxide composite is poor in stability and gels within a few hours if left to stand. Therefore, after cation exchange, an amine compound is quickly added to stabilize the silicon dioxide / oxidized An amine compound having a stannic mass ratio of 0.1 to 5.0 and a molar ratio of M / (SnO ₂ + SiO ₂ ) (wherein M represents an amine compound) of 0.1 to 1.0 It is necessary to prepare an aqueous sol of silicon dioxide-stannic oxide composite oxide colloidal particles (B ′) having a primary particle diameter of 1 to 4 nm stabilized by 1). The obtained aqueous sol is 0.1 to 10% by mass as (SnO ₂ + SiO ₂ ).

For stabilizing the silicon dioxide-stannic oxide composite colloidal particles produced by the cation exchange, a molar ratio of M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) is 0.1 to 1. Addition of an amine compound in an amount of 0.0 is appropriate. Addition of an amine compound having a molar ratio of M / (SnO ₂ + SiO ₂ ) of less than 0.1 to 1.0 is not preferable because it loses stability and is gelated after standing for several hours.

Next, in step (b), at least one selected from the group consisting of Ti, Fe, Zr, Sn, Ta, Nb, Y, Mo, W, Pb, In, Bi and Sr having a primary particle size of 5 to 60 nm. The mass ratio of the aqueous sol of the metal oxide colloidal particles (A) and the silicon dioxide / stannic oxide obtained in the step (a) is 0.1 to 5.0 and 0.1 to 1.0. Silicon dioxide-stannic oxide composite oxide colloidal particles having a primary particle size of 1 to 4 nm stabilized with an amine compound having a molar ratio of M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) The aqueous sol of (B ′) is used as the mass ratio (B ′) / (A) of the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′) to the metal oxide colloidal particles (A). By mixing at a ratio of 0.05 to 0.50 An aqueous sol of modified metal oxide colloidal particles (C ′) in which the metal oxide colloidal particles (A) are coated with the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′) can be obtained. .

  The solid content concentration of the aqueous sol of the metal oxide colloidal particles (A) is 0.5 to 50% by mass, and preferably 5 to 30% by mass.

  As the aqueous sol of the metal oxide colloidal particles (A), one having a pH of 5 to 11.5, preferably 7 to 11.5 can be used. The pH of the aqueous sol can be adjusted with an alkali component as required. Examples of the alkali component used include alkali metal hydroxides such as lithium, sodium and potassium, and alkaline earth metals such as calcium, magnesium and strontium. Hydroxide, ammonia, ethylamine, triethylamine, isopropylamine, alkylamines such as n-propylamine, aralkylamines such as benzylamine, alicyclic amines such as piperidine, alkanolamines such as monoethanolamine, triethanolamine, etc. A quaternary ammonium hydroxide etc. are mentioned.

  The mixing of the aqueous sol of the metal oxide colloidal particles (A) and the aqueous sol obtained in the step (a) is preferably performed with stirring.

  The mixing ratio of the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′) to the metal oxide colloidal particles (A) is 0.05 to 0.00 as a mass ratio (B ′) / (A). 50 is preferable, and if it is less than 0.05, the metal oxide colloidal particles (A) serving as nuclei cannot be sufficiently coated with the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′). Further, 0.50 is sufficient as the mass ratio, and even if it exceeds 0.50, it is not efficient.

Next, in step (c), cation exchange of the aqueous sol of the modified metal oxide colloidal particles (C ′) obtained in step (b) is performed. It is preferable to use a hydrogen type strongly acidic cation exchange resin for the cation exchange.
Next, in step (d), M / (SnO ₂ + SiO ₂ ) is used as the molar ratio of the amine compound to the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′) in the aqueous sol obtained in step (c). ) (Wherein M represents an amine compound) is added in an amount of 0.001 to 0.08 of the amine compound. When the amount of the amine compound to be added is less than 0.001 as the molar ratio of M / (SnO ₂ + SiO ₂ ), the silane-treated modified metal oxide colloidal particles of the present invention are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C. Further, the dispersion stability of the alcoholic organic solvent-dispersed sol prepared in the middle step of producing the sol is not preferable. Further, when the molar ratio of M / (SnO ₂ + SiO ₂ ) exceeds 0.08, the silyl represented by the general formula (I) bonded to the particle surface of the modified metal oxide colloidal particles (C). This is not preferable because it hinders bonding of groups.

  Next, in step (e), the dispersion medium of the aqueous sol obtained in step (d) is replaced with an alcoholic organic solvent. As a method of replacing the dispersion medium from water with an alcoholic organic solvent, a known method can be used. For example, an evaporation replacement method, an ultrafiltration membrane method, a solvent extraction method, or the like under normal pressure or reduced pressure can be used.

  In order to perform solvent substitution efficiently, the aqueous sol obtained in step (d) is prepared in advance so that the concentration of the modified metal oxide colloidal particles (C) contained is in the range of 1 to 70% by mass, or 10 to 50% by mass. It is preferable to concentrate. The sol can be concentrated by a known method such as a heat evaporation method or an ultrafiltration method. The temperature of the sol at the time of solvent replacement is in the range of room temperature to the boiling point of the alcoholic organic solvent. The solvent replacement is performed until the water content in the sol becomes less than 5% by mass.

  The solid content concentration of the sol obtained in the step (e) is 20 to 70% by mass as the total metal oxide concentration of the modified metal oxide colloidal particles (C).

  Examples of the alcoholic organic solvent used include methanol, ethanol, n-propanol, iso-propanol, n-butanol, t-butyl alcohol, and amyl alcohol.

  Next, in the step (f), the dispersion medium of the alcoholic organic solvent dispersion sol obtained in the step (e) is replaced with a non-alcoholic organic solvent. A known method can be used to replace the dispersion medium from the alcoholic organic solvent to the non-alcoholic organic solvent. For example, an evaporation replacement method, an ultrafiltration membrane method, a solvent extraction method, or the like under normal pressure or reduced pressure is used. be able to.

  As the non-alcoholic organic solvent to be used, those having good compatibility with the dicarboxylic acid anhydride are preferable, and the boiling point is 100 ° C. or lower so that the solvent can be easily removed in the production process of the epoxy curing agent of the present invention. Are preferred. Specifically, diethyl ether, methyl acetate, ethyl acetate, acetone, methyl ethyl ketone, n-hexane, cyclohexane, dichloromethane, acetonitrile and the like are preferable.

Next, in step (g), the non-alcoholic organic solvent-dispersed sol obtained in step (f) is added to the following general formula (II):
Si (R ¹ ) _a (X) _4-a (II)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A represents an integer of 0 to 3), and the mass ratio of the organosilane compound and / or the hydrolyzate thereof to the modified metal oxide colloidal particles (C) is 0.01 to 0. .50 to give a general formula (I)
-Si (R ¹ ) _a (X) _3-a (I)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. (A represents an integer of 0 to 3)) is bonded to the surface of the modified metal oxide colloidal particles (C).

  Examples of the organosilane compound of the general formula (II) used in the step (f) are as described above, and the alcoholic organic solvent dispersion sol of the modified metal oxide colloidal particles (C) obtained in the step (e) is used. By adding and aging the organosilane compound represented by the general formula (II), the silyl group represented by the formula (II) is bonded to the surface of the modified metal oxide colloidal particles (C). .

  In order to produce the silyl group represented by the formula (I) from the organosilane compound represented by the general formula (II), 1 to 4 mol of water is required per 1 mol of the organosilane compound. is there. This necessary water may be previously contained in the alcoholic organic solvent-dispersed sol, or may be added after the organosilane compound is added to the sol.

  After the organosilane compound is added to the alcoholic organic solvent dispersion sol, aging is performed. The aging temperature can be carried out in the range of the boiling point of the alcoholic organic solvent used from room temperature, and it is preferable that the aging is performed near the boiling point of the alcoholic organic solvent because the reaction efficiency of the silyl group is good.

  The aging can be performed under atmospheric pressure, and is preferably performed under reflux.

  The organic silane compound of the general formula (II) may be added after hydrolysis. The hydrolyzate of the organic silane compound can be obtained by adding water or an acidic aqueous solution of a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution, or an acetic acid aqueous solution to the organic silane compound and stirring them, as desired.

  The organic silane compound used is particularly preferably methyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, methacryloxypropyltrimethoxysilane and / or a hydrolyzate thereof.

(F) By performing the step, silane-treated modified metal oxide colloidal particles in which 0.1 to 4 silyl groups are bonded to the particle surface of the modified metal oxide colloidal particles (C) per 1 nm ² of the surface area. An alcoholic organic solvent is obtained. The solid content concentration of the obtained non-alcoholic organic solvent dispersion sol is 5 to 70% by mass as the total metal oxide concentration of the silane-treated modified metal oxide colloidal particles.

  Next, in step (h), the dispersion medium of the non-alcoholic organic solvent dispersion sol obtained in step (g) is replaced with a liquid dicarboxylic anhydride at 30 ° C. A known method can be used to replace the dispersion medium from the alcoholic organic solvent to the non-alcoholic organic solvent. For example, an evaporation replacement method, an ultrafiltration membrane method, a solvent extraction method, or the like under normal pressure or reduced pressure is used. be able to.

  The liquid dicarboxylic acid anhydride used at 30 ° C is methyltetrahydrophthalic acid anhydride, methylhexahydrophthalic acid anhydride, methyl nadic acid anhydride, hydrogenated methyl nadic acid anhydride, hydrogenated trimellitic acid anhydride. , Trialkylhydrophthalic anhydride, dodecenyl succinic anhydride and the like. Among these, methylhexahydrophthalic anhydride, hydrogenated methylnadic acid anhydride, or hydrogenated trimellitic anhydride is preferable from the viewpoint of heat resistance, light resistance, and colorless transparency.

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not construed as being limited thereto.

The physical property measuring method of each colloid particle and each epoxy curing agent is shown below.
〔moisture〕
It was determined by Karl Fischer titration.
[Particle diameter of colloidal particles by dynamic light scattering method]
Each sol was diluted with the same solvent as the dispersion medium, and measured with a Coulter N5 (trade name: manufactured by Coulter, USA) using the parameters of the solvent.
[Total metal oxide concentration]
The sample was weighed in a crucible and calculated from the residue baked at 800 ° C. in the crucible.
[Organic solvent content]
It was determined by gas chromatography.

  The gas chromatography conditions were as follows.

Column: 3 mm x 1 m glass column Filler: Polar pack Q
Column temperature: 130-230 ° C. (temperature increase 8 ° C./min)
Carrier: N ₂ 40 mL / min
Detector: FID
Injection volume: 1 μL
Internal standard: methyl ethyl ketone [viscosity]
The viscosity of the epoxy curing agent at 30 ° C. was measured using a B-type rotational viscometer manufactured by Toki Sangyo Co., Ltd.
(Light transmittance)
When the concentration of the silane-treated modified metal oxide colloid particles in the epoxy curing agent is adjusted to 10% by mass, the light transmittance at an optical path length of 10 mm at a wavelength of 500 nm is measured using a color meter (TC-1800MK2 manufactured by Tokyo Denshoku Co., Ltd.). Pure water was used for the blank, and the liquid temperature was 23 ° C.

Example 1
36 g of JIS 3 sodium silicate (containing 29.8 mass% as SiO ₂ , manufactured by Fuji Chemical Co., Ltd.) was dissolved in 400 g of pure water, and then sodium stannate NaSnO ₃ .H ₂ O (55.1 mass% as SnO ₂₎ 9.8 g (contained, Showa Kako Co., Ltd.) was dissolved. By passing the obtained aqueous solution through a column filled with a hydrogen cation exchange resin (Amberlite (registered trademark) IR-120B), an aqueous sol of acidic stannic oxide-silica composite colloidal particles (pH 2.4, SnO ₂ containing 0.44% by mass, SiO ₂ containing 0.87% by mass, SiO ₂ / SnO ₂ mass ratio 2.0) 1240 g was obtained. Next, 3.2 g of diisopropylamine was added to the obtained aqueous sol. The obtained sol was an aqueous sol of alkaline stannic oxide-silica composite colloidal particles and had a pH of 8.0. In the aqueous sol, colloidal particles having a primary particle diameter of 5 nm or less were observed with a transmission electron microscope. The molar ratio of diisopropylamine / (SnO ₂ + SiO ₂ ) was 0.15.

Separately, 251.85 kg of tetramethylammonium hydrogen carbonate aqueous solution (manufactured by Tama Chemical Industry Co., Ltd., containing 42.4% by mass in terms of tetramethylammonium hydroxide) and 95. pure water in a 1 m ³ reaction vessel. 6 kg was added to obtain a diluted aqueous solution. While stirring this aqueous solution, zirconium oxycarbonate powder (ZrOCO ₃ , manufactured by AMR, containing 40.11% by mass as ZrO ₂ ) was gradually added to the aqueous solution, and a total of 491.85 kg was added. After completion of the addition, after heating to 85 ° C., 8.23 kg of metastannic acid (produced by Showa Kako Co., Ltd., containing 7.08 kg as SnO ₂ ) is gradually added, followed by aging at 105 ° C. for 5 hours. It was. At the end of this heat aging, the mixed solution was sol. Further, hydrothermal treatment was performed at 145 ° C. for 5 hours. What was obtained after the hydrothermal treatment was a sol containing colloidal particles of a zirconium oxide-stannic oxide complex, having a (ZrO ₂ + SnO ₂ ) concentration of 12.86% by mass, a specific gravity of 1.180, and a pH of 10.62. Met. Next, the sol was washed and concentrated while adding pure water using an ultrafiltration device. As a result, the zirconium oxide-tin oxide composite colloidal particles having a density of 6.03 mass% and a specific gravity of 1.052 and a pH of 9.43 were obtained. 1040 kg of sol containing was obtained. The obtained zirconium oxide-stannic oxide composite colloid had a particle diameter of 5 to 15 nm as observed with an electron microscope.

The aqueous sol of alkaline silicon dioxide-stannic oxide composite colloidal particles produced in advance to 830 g of the aqueous sol of zirconium oxide-stannic oxide composite colloidal particles obtained above (containing 50 g as ZrO ₂ + SnO ₂ ). 769 g was added and stirred thoroughly. Next, the mixture was aged by heating at 95 ° C. for 2 hours to obtain 1599 g of an aqueous sol of modified zirconium oxide-stannic oxide composite colloidal particles coated with silicon dioxide-stannic oxide composite colloidal particles. The obtained sol had a pH of 8.3 and a total metal oxide concentration of 3.7% by mass. The obtained aqueous sol of modified zirconium oxide-stannic oxide composite colloidal particles is passed through a column packed with 500 g of a hydrogen type cation exchange resin (Amberlite IR-120B), and an acidic modified zirconium oxide-stannic oxide composite is passed. 1980 g of an aqueous sol of colloidal particles was obtained. The obtained sol had a pH of 2.7 and a total metal oxide concentration of 3.0% by mass. 0.5 g of diisobutylamine was added to the obtained acidic sol, and diisobutylamine was bound to the surface of the modified zirconium oxide-stannic oxide colloidal particles. The pH of the sol at this time was 4.3. Subsequently, the obtained sol was concentrated using an ultrafiltration device until the total metal oxide concentration became 20% by mass. The specific gravity of the aqueous sol concentrated to a total metal oxide concentration of 20% by mass was 1.211, and the pH was 3.7. This concentrated aqueous sol is put into an evaporator with an eggplant-shaped flask, and water is distilled off at 600 Torr while adding methanol to the sol, whereby methanol of modified zirconium oxide-stannic oxide colloidal particles bound with diisobutylamine is added. A sol was obtained. The obtained methanol sol had a specific gravity of 0.961, a viscosity of 1.0 mPa · s, a pH of 4.9 (measured by diluting with water of the same mass as the sol), a total metal oxide concentration of 21% by mass, and a water content of 2. 3%. To the obtained methanol sol, 7.6 g of phenyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., trade name: KBM-103) was added, and silylation was carried out by reflux heating at about 70 ° C. for 5 hours. Groups were attached to the surface of the modified zirconium oxide-stannic oxide colloidal particles. Silane with diisobutylamine and phenyldimethoxysilyl groups bonded to the surface by replacing methanol with acetonitrile by distilling off methanol while adding acetonitrile to the obtained methanol sol at 80 Torr using an evaporator. An acetonitrile sol of treated modified zirconium oxide-stannic oxide colloidal particles was obtained. The obtained sol had a viscosity of 1.2 mPa · s, a total metal oxide concentration of 26.6% by mass, a primary particle size of 5 to 10 nm and a dynamic light scattering method particle size of 18 nm as observed with a transmission electron microscope. . The molar ratio of diisobutylamine / (SnO ₂ + SiO ₂ ) is 0.029, and the number of silyl groups bonded to the surface of the silane-treated modified zirconium oxide-stannic oxide colloidal particle is determined by the surface area of the colloidal particle. The number was 1.4 per 1 nm ² . The physical properties of the obtained acetonitrile sol were as follows: acetonitrile concentration 73.0% by mass, methanol concentration 0.1%, water 0.1% by mass, diisobutylamine 0.2% by mass, and the sol was diluted with an equal mass of water. In this case, the pH was 5.3. 136 g of methylhexahydrophthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to 218 g of this acetonitrile sol, and the silane treatment was modified by evaporating and evaporating acetonitrile at 340 to 20 Torr and a bath temperature of 70 to 90 ° C. with an evaporator. A methylhexahydrophthalic anhydride-dispersed sol of ruthenium-stannic oxide colloidal particles was obtained. The physical properties of the obtained sol were as follows: the total metal oxide concentration was 30.0% by mass, the methylhexahydrophthalic anhydride concentration was 69.9% by mass, the acetonitrile concentration was 0.1% by mass, and the B-type viscosity at 30 ° C. was 80 mPa · s, light transmittance was 49%. The refractive index of the resulting silane-treated modified ruthenium-stannic oxide colloidal particle methylhexahydrophthalic anhydride dispersion sol was measured with an Abbe refractometer and found to be 1.504. The refractive index of methylhexahydrophthalic anhydride alone was 1.475. The obtained silane-treated modified ruconium-stannic oxide colloidal particles of methylhexahydrophthalic anhydride dispersion sol were sealed in a glass container and stored at 25 ° C. for 1 month. The appearance was colorless and transparent, and stable during storage. It was.

  The cured epoxy resin using the epoxy curing agent of the present invention has a high refractive index and excellent transparency, and can be industrially used for sealing optical semiconductor elements such as LEDs.

Claims (12)

Ti, Fe, Zr, Sn having a primary particle diameter of 5 to 60 nm, which is a modified metal oxide colloidal particle having a metal oxide colloidal particle as a core and an outer surface coated with a composite oxide colloidal particle. , Ta, Nb, Y, Mo, W, Pb, In, Bi, and Sr. The oxide colloidal particles (A) of at least one metal selected from the group consisting of nuclei and the outer surface of which are silicon dioxide / oxidized The amine compound is bonded at a molar ratio of stannic mass ratio of 0.1 to 5.0 and M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) of 0.001 to 0.08. A modified metal oxide colloidal particle (C) coated with silicon dioxide-stannic oxide composite oxide colloidal particles (B) having a primary particle diameter of 1 to 4 nm, and a metal oxide Colloidal particles (A) Composite oxide weight ratio of colloidal particles (B) (B) / ( A) is 0.05 to 0.50, and 0.1 the surface area per 1 nm ² on the particle surfaces of the colloidal particles (C) against A sol in which silane-treated modified metal oxide colloidal particles, which are formed by bonding four silyl groups, are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C. The silyl group is represented by the following general formula (I)
-Si (R ¹ ) _a (X) _3-a (I)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A sol in which the silane-treated modified metal oxide colloidal particles according to claim 1 are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C.   2. The dicarboxylic acid in which the silane-treated modified metal oxide colloidal particles are liquid at 30 ° C. according to claim 1, wherein the amine compound is at least one compound selected from the group consisting of primary amines, secondary amines and tertiary amines. A sol dispersed in an anhydride.   The dicarboxylic acid anhydride is at least one selected from the group consisting of methylhexahydrophthalic anhydride, hydrogenated methylnadic acid anhydride, and hydrogenated trimellitic acid anhydride. A sol in which the silane-treated modified metal oxide colloidal particles according to the item are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C.   The silane-treated modified metal oxide colloidal particles according to any one of claims 1 to 4 containing 5 to 70% by mass of the silane-treated modified metal oxide colloidal particles are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C. Sol.   An epoxy curing agent comprising a sol in which the silane-treated modified metal oxide colloidal particles according to any one of claims 1 to 5 are dispersed in a liquid dicarboxylic acid anhydride at 30 ° C.   The epoxy curing agent according to claim 6, comprising 0.01 to 50 parts by mass of a non-alcoholic organic solvent with respect to 100 parts by mass of the silane-treated modified metal oxide colloidal particles.   An epoxy resin curing composition comprising the epoxy curing agent according to claim 6 or 7 and an epoxy resin.   Furthermore, the composition for epoxy resin hardening of Claim 8 containing a hardening accelerator.   The composition for epoxy resin curing according to claim 9, wherein the epoxy curing agent contains 50 to 500 parts by mass and the curing accelerator contains 0.1 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin.   An epoxy resin cured body using the epoxy resin curing agent according to claim 6. The silane according to any one of claims 1 to 5, comprising the following steps (a), (b), (c), (d), (e), (f), (g) and (h). Method for producing sol in which treated modified metal oxide colloidal particles are dispersed in liquid dicarboxylic anhydride at 30 ° C .:
Step (a): An aqueous solution containing alkali stannate and alkali silicate in a mass ratio of silicon dioxide / stannic oxide in a ratio of 0.1 to 5 is prepared, and then cations present in the aqueous solution are removed. An aqueous sol of silicon dioxide-stannic oxide composite colloidal particles having a primary particle size of 1 to 4 nm is prepared, and M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound). ) Is added in an amount such that the molar ratio of 0.1 to 1.0 is such that the mass ratio of silicon dioxide / stannic oxide is 0.1 to 5.0 and 0.1 to 1 0.02 M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) a silicon dioxide-stannic oxide composite having a primary particle size of 1-4 nm stabilized with an amine compound present in a molar ratio Aqueous solution of oxide colloidal particles (B ') A process of obtaining
(B) Step: at least one metal selected from the group consisting of Ti, Fe, Zr, Sn, Ta, Nb, Y, Mo, W, Pb, In, Bi and Sr having a primary particle size of 5 to 60 nm The aqueous sol of the oxide colloidal particles (A) and the aqueous sol obtained in the step (a) are used as the silicon dioxide-stannic oxide composite oxide colloidal particles for the metal oxide colloidal particles (A) ( B ′) is mixed in such an amount that the mass ratio (B ′) / (A) is 0.05 to 0.50, whereby the metal oxide colloidal particles (A) are converted into the silicon dioxide-stannic oxide. Obtaining an aqueous sol of modified metal oxide colloidal particles (C ′) coated with the composite oxide colloidal particles (B ′);
(C) step: a step of cation-exchange the aqueous sol of the modified metal oxide colloidal particles (C ′) obtained in the step (b) and removing the amine compound added in the step (a),
Step (d): In the aqueous sol obtained in Step (c), M / (SnO ₂ + SiO ₂ ) (as the molar ratio of the amine compound to the silicon dioxide-stannic oxide composite oxide colloidal particles (B ′)) Where M represents an amine compound) by adding an amount of an amine compound in an amount of 0.001 to 0.08, and the outer surface of the metal oxide colloidal particles (A) is made of silicon dioxide / The amine compound has a molar ratio of M / (SnO ₂ + SiO ₂ ) (where M represents an amine compound) in which the mass ratio of stannic oxide is 0.1 to 5.0 and 0.001 to 0.08. A colloidal particle (C) formed by coating with a bonded silicon dioxide-stannic oxide composite oxide colloidal particle (B) having a primary particle diameter of 1 to 4 nm, and a colloidal particle of the metal oxide ( Said dioxide for A) Obtaining an aqueous sol of modified metal oxide colloidal particles (C) having a mass ratio (B) / (A) of the silicon-stannic oxide composite oxide colloidal particles (B) of 0.05 to 0.50,
(E) Step: A step of replacing the dispersion medium of the aqueous sol obtained in the step (d) with an alcoholic organic solvent,
Step (f): The alcoholic organic solvent sol obtained in Step (e) is added to the following general formula (II):
Si (R ¹ ) _a (X) _4-a (II)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A represents an integer of 0 to 3), and the mass ratio of the organosilane compound and / or the hydrolyzate thereof to the modified metal oxide colloidal particles (C) is 0.01 to 0. .50 to give a general formula (I)
-Si (R ¹ ) _a (X) _3-a (I)
(However, R ¹ is a substituted or unsubstituted alkyl group or halogenated alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 6 to 12 carbon atoms, or Represents an unsubstituted aryl group or a halogenated aryl group, or represents an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group or a cyano group, and X represents a hydroxyl group or an alkoxy group having 1 to 4 carbon atoms. A represents an integer of 0 to 3), and a step of binding the silyl group represented by the surface of the modified metal oxide colloidal particles (C);
(G) Step: A step of replacing the dispersion medium of the alcoholic organic solvent sol of the silane-containing modified metal oxide colloidal particles obtained in the step (f) with a non-alcohol organic solvent,
(H) Step: A step of replacing the dispersion medium of the non-alcohol organic solvent dispersion sol of the silane-treated modified metal oxide colloidal particles obtained in the step (g) with a liquid dicarboxylic anhydride at 30 ° C.