Nissan Chemical Industries Limited

Nissan Chemical Corporation

Kyushu Institute of Technology

Naohiko Suemura

Keiko Yoshitake

Toshiaki Takeyama

Masatoshi Sugisawa

Kazuya Kuroiwa

Ichitaro Kikunaga

Megumi Shimada

Hikaru Onishi

Yoshinari Koyama

Masayuki Hikita

Jiahao Liu

Megumi Araki

Takeshi Nakada

Tomoya Maeta

Yuki Sugawara

Takao Akahoshi

Kyunghoon Jang

Masahiro Kozako

Tomohisa Ishida

A silica sol including silica particles exhibiting an average particle diameter distribution having at least two peaks, the silica sol being characterized in that the at least two peaks include the largest peak a, in a range of D50-D90, being present in a range of 35-200 nm, and the largest peak b, in a range of D10-D50, being present in a range from 5 nm to less than 35 nm, and that the surfaces of at least some of silica particles include an organic group bonded directly to a silicon atom via an Si—C bond, and an alkoxy group including a methoxy group or an ethoxy group, wherein the alkoxy group is bonded to the surface of the silica particles at a ratio of 0.6-3.0 alkoxy groups/nm.

Silica sol having particle size distribution and production method therefor

An insulating composition containing silica particles, a resin, and a curing agent, wherein: when an aqueous solution of the silica particles having an SiOconcentration of 3.8% by mass is heated at 121° C. for 20 hours, the amount of Na ions eluted from the silica particles is 40 ppm/SiOor less, especially, wherein the amount of Na ions eluted from the silica particles after the heating may be 5-38 ppm/SiO, and, the silica particles may contain a polyvalent metal oxide so the ratio by mole of a polyvalent metal M to Si is 0.001-0.02; the mass ratio of NaO/SiOin the silica particles may be 700-1,300 ppm; and the silica particles may have, on the surfaces thereof, a layer having a thickness of 0.1-1.5 nm and an NaO/SiOmass ratio of 10-400 ppm, and may have an average particle diameter of 5-40 nm.

Silica-containing insulating composition

A silica sol dispersed in a nitrogen-containing solvent and a silica-containing resin composition containing a nitrogen atom-containing polymer. A silica sol including silica particles containing aluminum atoms and having an average primary particle diameter of 5 to 100 nm, the silica particles being dispersed in a nitrogen-containing solvent, wherein the aluminum atoms are bonded to the surfaces of the silica particles in an amount in terms of AlOof 800 to 10,000 ppm/SiO. The silica particles are bonded to a silane compound or a hydrolysate of the silane compound. The nitrogen-containing solvent is an amide solvent. The nitrogen-containing solvent is dimethylacetamide, dimethylformamide, N-methylpyrrolidone, or N-ethylpyrrolidone. The insulating resin composition includes the silica sol and a nitrogen-containing polymer. The nitrogen-containing polymer is polyimide, polyamide, polyamic acid, polyamideimide, polyetherimide, or polyesterimide. An insulation-coated conductor wire produced by insulation coating of a conductor wire with the insulating resin composition.

Aluminum-containing silica sol dispersed in nitrogen-containing solvent and resin composition

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 Cparaffinic hydrocarbon, a Cnaphthenic hydrocarbon, or a mixture of these, a Calcohol 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 Calkyl group bonded to a silicon atom and a Calkyl 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 Calkyl group.

Inorganic oxide sol dispersed in hydrocarbon and production method therefor

A method for preventing occurrence of creeping electrical discharge at a resin surface, the method being characterized by including dispersing nanosized inorganic fine particles in a resin, thereby preventing occurrence of creeping electrical discharge at the surface of a cured product of the resin.

Method for inhibiting occurrence of creeping electrical discharge

A silica-blended resin varnish contains a silica sol with a high dispersibility that is dispersed in a ketone organic solvent, in a nitrogen atom-containing polymer. The particles have an average size of 5 to 100 nm and have a carbon-carbon unsaturated bond-containing organic group and an alkoxy group bonded to surfaces thereof. The carbon-carbon unsaturated bond-containing organic group is bonded at 0.5 to 2.0 groups per unit area (nm) of the particle surfaces. The alkoxy group is bonded at 0.1 to 2.0 groups per unit area (nm) of the particle surfaces. The molar ratio of {(the carbon-carbon unsaturated bond-containing organic group)/(the alkoxy group)} is 0.5 to 5.0. The carbon-carbon unsaturated bond-containing organic group may be a phenyl group-containing organic group or a (meth)acryloyl group-containing organic group. An insulating resin composition contains the silica sol and a nitrogen-containing polymer, which may be polyimide, polyamide, polyamic acid, polyamide-imide, polyetherimide, or polyesterimide.

Silica sol dispersed in ketone solvent and resin composition

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 m/g; (b) the silica particles have a moisture absorption amount per specific surface area thereof of 0.5 mg/mor less; and (c) the organic base compound is not substantially contained in the inside thereof.

Silica sol and method for producing silica sol

The silica sol of the invention contains silica particles having a mean primary particle size of 20 to 100 nm and which has a silica particle size/mean primary particle size ratio, determined through dynamic light scattering, of 3.0 or less, wherein the silica particles are surface-treated with an organic silane compound and have an &#x3b1;-ray emission rate of 0.005 counts/cm&#xb7;hr or less and a moisture absorption coefficient, determined after allowing the silica particles to stand for 48 hours at 23&#xb0; C. and a relative humidity of 50 RH %, of 0.5 mass % or lower.

Silica sol and silica-containing epoxy resin composition

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 (nm) 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.

Colloidal silica particles, process for producing the same, and organic solvent-dispersed silica sol, polymerizable compound-dispersed silica sol, and dicarboxylic anhydride-dispersed silica sol each obtained from the same

Process for producing colloidal silica particles

There is provided a liquid preparation for forming an epoxy resin having curing properties combining high transparency and high bending strength while maintaining advantageous handling properties as in a liquid state. A liquid preparation for forming an epoxy resin comprising: an A agent; and a B agent; wherein the A agent contains a modified epoxy resin (I) formed from at least one type of compound (i) having in a molecule thereof, at least one functional group of Formula (1): (where Rand Rindividually represent an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, a heterocyclic group or a halogenated, aminated or nitrated derivative of any of the groups) and a compound (ii) having a glycidyl group in a molecule thereof, and an inorganic particle (II); and the B agent contains a curing agent (III). A liquid preparation for forming an epoxy resin comprising: an A' agent; and a B&#x2032; agent; wherein the A&#x2032; agent contains the modified epoxy resin (I); and the B&#x2032; agent contains the inorganic particle (II) and the curing agent (III).

Epoxy resin-forming liquid preparation containing inorganic particle

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. The present invention provides 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.

Reactive monomer-dispersed silica sol and production method thereof, and curable composition and cured article thereof

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&#xb0; 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.

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Sodegaura, Japan

Naohiko Suemura