Abstract: A sol of inorganic oxide particles is stably dispersed in a hydrophilic organic solvent containing a hydrocarbon such as a paraffinic hydrocarbon or a naphthenic hydrocarbon. The sol contains a dispersion medium containing an organic solvent containing a C6-18 paraffinic hydrocarbon, a C6-18 naphthenic hydrocarbon, or a mixture of these, a C4-8 alcohol having a carbon chain with a carbon-carbon bond in the molecule in an amount of 0.1 to 5% by mass in the entire dispersion medium, and inorganic oxide particles having an average particle diameter of 5 to 200 nm as measured by dynamic light scattering as a dispersoid, wherein the inorganic oxide particles contain a C1-3 alkyl group bonded to a silicon atom and a C4-18 alkyl group. The paraffinic hydrocarbon is a normal paraffinic hydrocarbon or an isoparaffinic hydrocarbon. The naphthenic hydrocarbon is a saturated aliphatic cyclic hydrocarbon substitutable with a C1-10 alkyl group.

Abstract: A sol of inorganic oxide particles is stably dispersed in a hydrophilic organic solvent containing a hydrocarbon such as a paraffinic hydrocarbon or a naphthenic hydrocarbon. The sol contains a dispersion medium containing an organic solvent containing a C6-18 paraffinic hydrocarbon, a C6-18 naphthenic hydrocarbon, or a mixture of these, a C4-8 alcohol having a carbon chain with a carbon-carbon bond in the molecule in an amount of 0.1 to 5% by mass in the entire dispersion medium, and inorganic oxide particles having an average particle diameter of 5 to 200 nm as measured by dynamic light scattering as a dispersoid, wherein the inorganic oxide particles contain a C1-3 alkyl group bonded to a silicon atom and a C4-18 alkyl group. The paraffinic hydrocarbon is a normal paraffinic hydrocarbon or an isoparaffinic hydrocarbon. The naphthenic hydrocarbon is a saturated aliphatic cyclic hydrocarbon substitutable with a C1-10 alkyl group.

Abstract: Disclosed are a charge transporting varnish comprising a specific oligoaniline compound, an electron accepting dopant, a metal oxide nanoparticle, and an organic solvent; a charge transporting film prepared from the charge transporting varnish; an electronic device and an organic electroluminescent device having the charge transporting film; and a method for producing the charge transporting film using the charge transporting varnish.

Abstract: A silica sol which has excellent moisture absorption resistance and stability as well as high purity and which does not cause coloring of a solvent or a resin to which the silica sol has been applied. The silica sol contains high-purity silica particles, water and/or a liquid organic medium serving as a dispersion medium, and an organic base compound, the silica particles being dispersed in the dispersion medium, wherein the silica particles satisfy the following requirements (a) to (c): (a) the silica particles have a specific surface area, as determined through a nitrogen absorption method, of 20 to 500 m2/g; (b) the silica particles have a moisture absorption amount per specific surface area thereof of 0.5 mg/m2 or less; and (c) the organic base compound is not substantially contained in the inside thereof.

Abstract: The invention provides silica particles, formed from an alkoxysilane serving as a raw material, characterized in that the silica particles satisfy the following requirements (a) to (c): (a) the silica particles have an alkali metal element content of 5 ppm or less, with respect to the silica solid content; (b) the silica particles exhibit a moisture absorption of 0.25 mg/m2 or less at 50% relative humidity, and a refractive index, as determined through the liquid immersion method, of 1.450 to 1.460; and (c) the silica particles have a mean primary particle size, derived from a specific surface area as determined through the nitrogen adsorption method, of 10 to 100 nm.

Abstract: A silica-containing resin composition, characterized by containing a resin and silica particles in an amount of 5 to 300 parts by mass, with respect to 100 parts by mass of the resin, wherein the silica particles satisfy the following requirements (a) to (c): (a) the silica particles have a specific surface area, as determined through a nitrogen absorption method, of 20 to 500 m2/g; (b) the silica particles have a percent moisture absorption of 5.0 mass % or less at a relative humidity of 50%; and (c) the silica particles contain substantially no metallic impurity or halogen.

Abstract: The invention provides silica particles, formed from an alkoxysilane serving as a raw material, characterized in that the silica particles satisfy the following requirements (a) to (c): (a) the silica particles have an alkali metal element content of 5 ppm or less, with respect to the silica solid content; (b) the silica particles exhibit a moisture absorption of 0.25 mg/m2 or less at 50% relative humidity, and a refractive index, as determined through the liquid immersion method, of 1.450 to 1.460; and (c) the silica particles have a mean primary particle size, derived from a specific surface area as determined through the nitrogen adsorption method, of 10 to 100 nm.

Abstract: There is provided colloidal silica particles comprising at least one polyvalent metal element M selected from a group consisting of iron, aluminum, zinc, zirconium, titanium, tin, and lead in an average content of 0.001 to 0.02 in terms of an M/Si molar ratio, and having an average primary particle diameter of 5 to 40 nm, wherein the content of the polyvalent metal element M present in an outermost layer of the colloidal particles is 0 to 0.003 atom per square nanometer (nm2) of a surface area of the colloidal particles; and a silica sol that the colloidal silica particles are dispersed in an organic solvent, a silica sol that the colloidal silica particles are dispersed in a polymerizable compound, and a silica sol that the colloidal silica particles are dispersed in a dicarboxylic anhydride.

Abstract: There is provided colloidal silica particles comprising at least one polyvalent metal element M selected from a group consisting of iron, aluminum, zinc, zirconium, titanium, tin, and lead in an average content of 0.001 to 0.02 in terms of an M/Si molar ratio, and having an average primary particle diameter of 5 to 40 nm, wherein the content of the polyvalent metal element M present in an outermost layer of the colloidal particles is 0 to 0.003 atom per square nanometer (nm2) of a surface area of the colloidal particles; and a silica sol that the colloidal silica particles are dispersed in an organic solvent, a silica sol that the colloidal silica particles are dispersed in a polymerizable compound, and a silica sol that the colloidal silica particles are dispersed in a dicarboxylic anhydride.

Abstract: There is provided colloidal silica particles comprising at least one polyvalent metal element M selected from a group consisting of iron, aluminum, zinc, zirconium, titanium, tin, and lead in an average content of 0.001 to 0.02 in terms of an M/Si molar ratio, and having an average primary particle diameter of 5 to 40 nm, wherein the content of the polyvalent metal element M present in an outermost layer of the colloidal particles is 0 to 0.003 atom per square nanometer (nm2) of a surface area of the colloidal particles; and a silica sol that the colloidal silica particles are dispersed in an organic solvent, a silica sol that the colloidal silica particles are dispersed in a polymerizable compound, and a silica sol that the colloidal silica particles are dispersed in a dicarboxylic anhydride.

Abstract: A silica sol which has excellent moisture absorption resistance and stability as well as high purity and which does not cause coloring of a solvent or a resin to which the silica sol has been applied. The silica sol contains high-purity silica particles, water and/or a liquid organic medium serving as a dispersion medium, and an organic base compound, the silica particles being dispersed in the dispersion medium, wherein the silica particles satisfy the following requirements (a) to (c): (a) the silica particles have a specific surface area, as determined through a nitrogen absorption method, of 20 to 500 m2/g; (b) the silica particles have a moisture absorption amount per specific surface area thereof of 0.5 mg/m2 or less; and (c) the organic base compound is not substantially contained in the inside thereof.

Abstract: A silica-containing resin composition, characterized by containing a resin and silica particles in an amount of 5 to 300 parts by mass, with respect to 100 parts by mass of the resin, wherein the silica particles satisfy the following requirements (a) to (c): (a) the silica particles have a specific surface area, as determined through a nitrogen absorption method, of 20 to 500 m2/g; (b) the silica particles have a percent moisture absorption of 5.0 mass % or less at a relative humidity of 50%; and (c) the silica particles contain substantially no metallic impurity or halogen.

Abstract: There is provided colloidal silica particles comprising at least one polyvalent metal element M selected from a group consisting of iron, aluminum, zinc, zirconium, titanium, tin, and lead in an average content of 0.001 to 0.02 in terms of an M/Si molar ratio, and having an average primary particle diameter of 5 to 40 nm, wherein the content of the polyvalent metal element M present in an outermost layer of the colloidal particles is 0 to 0.003 atom per square nanometer (nm2) of a surface area of the colloidal particles; and a silica sol that the colloidal silica particles are dispersed in an organic solvent, a silica sol that the colloidal silica particles are dispersed in a polymerizable compound, and a silica sol that the colloidal silica particles are dispersed in a dicarboxylic anhydride.

Abstract: There is provided colloidal silica particles comprising at least one polyvalent metal element M selected from a group consisting of iron, aluminum, zinc, zirconium, titanium, tin, and lead in an average content of 0.001 to 0.02 in terms of an M/Si molar ratio, and having an average primary particle diameter of 5 to 40 nm, wherein the content of the polyvalent metal element M present in an outermost layer of the colloidal particles is 0 to 0.003 atom per square nanometer (nm2) of a surface area of the colloidal particles; and a silica sol that the colloidal silica particles are dispersed in an organic solvent, a silica sol that the colloidal silica particles are dispersed in a polymerizable compound, and a silica sol that the colloidal silica particles are dispersed in a dicarboxylic anhydride.

Abstract: Colloidal silica particles dispersed in a reactive monomer may cause the polymerization, degradation, or the like of the reactive monomer by an action of the solid acidity of the surfaces of the particles and a monomer may be polymerized during a process for producing a monomer-dispersed silica sol, or a stable silica sol may not be obtained. In addition, a polymer of a resin formed article etc. obtained by curing a monomer-dispersed silica sol may be deteriorated, degraded, or the like with time. Therefore, there are provided a reactive monomer-dispersed silica sol having high stability by reducing the solid acidity of the surfaces of the colloidal silica particles contained in the reactive monomer-dispersed silica sol, and a production method thereof, and a curable composition using the reactive monomer-dispersed silica sol, and a cured article in which the deterioration, the degradation, or the like of the polymer is suppressed.

Abstract: A reactive monomer-dispersed silica sol having high stability by reducing the solid acidity of the surfaces of the colloidal silica particles contained in the reactive monomer-dispersed silica sol, and a production method thereof, and a curable composition using the reactive monomer-dispersed silica sol, and a cured article in which the deterioration, the degradation, or the like of the polymer is suppressed. A reactive monomer-dispersed silica sol containing a colloidal silica particle in which an alkaline earth metal ion is bonded to a surface of the colloidal silica particle.

Abstract: There is provided colloidal silica particles comprising at least one polyvalent metal element M selected from a group consisting of iron, aluminum, zinc, zirconium, titanium, tin, and lead in an average content of 0.001 to 0.02 in terms of an M/Si molar ratio, and having an average primary particle diameter of 5 to 40 nm, wherein the content of the polyvalent metal element M present in an outermost layer of the colloidal particles is 0 to 0.003 atom per square nanometer (nm2) of a surface area of the colloidal particles; and a silica sol that the colloidal silica particles are dispersed in an organic solvent, a silica sol that the colloidal silica particles are dispersed in a polymerizable compound, and a silica sol that the colloidal silica particles are dispersed in a dicarboxylic anhydride.

Abstract: A process for producing an inorganic oxide organosol that has good dispersibility and low viscosity, has excellent transparency, and shows good compatibility with resin solutions, and includes the steps (A) and (B) of: (A) adding silicon alkoxide having two or more alkoxy groups bonded to a silicon atom or having one or more hydroxy groups bonded to a silicon atom and one or more alkoxy groups bonded to a silicon atom to a hydrophilic inorganic oxide sol containing a hydrophilic solvent having a boiling point (1 atm) of 100° C. or less in an amount of 25 to 100% by weight in a dispersion medium to treat surface of the inorganic oxide particles in the sol; and (B) replacing the dispersion medium of the surface treated inorganic oxide sol obtained in step (A) with a non-alcoholic organic solvent in the presence of a primary alcohol having 3 to 12 carbon atoms.

Abstract: Colloidal silica particles dispersed in a reactive monomer may cause the polymerization, degradation, or the like of the reactive monomer by an action of the solid acidity of the surfaces of the particles and a monomer may be polymerized during a process for producing a monomer-dispersed silica sol, or a stable silica sol may not be obtained. In addition, a polymer of a resin formed article etc. obtained by curing a monomer-dispersed silica sol may be deteriorated, degraded, or the like with time. Therefore, there are provided a reactive monomer-dispersed silica sol having high stability by reducing the solid acidity of the surfaces of the colloidal silica particles contained in the reactive monomer-dispersed silica sol, and a production method thereof, and a curable composition using the reactive monomer-dispersed silica sol, and a cured article in which the deterioration, the degradation, or the like of the polymer is suppressed.

Abstract: A process for producing a hydrophobic silica powder, comprises the steps for hydrophobic treatment of: adding to a silica sol in mixed solvent having a silica concentration of 5 to 50 mass % obtained by mixing an aqueous silica sol containing hydrophilic colloidal silica having a specific surface area of 5.5 to 550 m2/g with a hydrophilic organic solvent in a mass ratio of 0.12 to 2.5 based on water in the aqueous silica sol, a disilazane compound of formula (1) (R13Si)2NH ??(1) wherein each R1 is C1-6alkyl group or phenyl group that is selected independently of one another, in an amount of 0.1 to 20 mmol per surface area 100 m2 of the hydrophilic colloidal silica, to obtain a mixture of the silica sol in mixed solvent and the disilazane compound; and heating the mixture at a temperature of 50 to 100° C. for aging it to obtain a slurry dispersion of hydrophobic treated colloidal silica. The process provides a hydrophobic silica powder through a simple hydrophobic treatment step.