CN-122003384-A - Surface-treated silica sol containing free silanol groups dispersed in nitrogen-containing solvent and insulating resin composition

CN122003384ACN 122003384 ACN122003384 ACN 122003384ACN-122003384-A

Abstract

Disclosed is a silica sol wherein silica particles are dispersed in a nitrogen-containing solvent for mixing with a polyimide-based or polyamide-based polar resin in a state of good compatibility, wherein the silica sol can be subjected to additional silane treatment according to the use or the like, is excellent in storage stability even at high concentrations, and has both customizability and reliability. The silica sol is a silica sol comprising silica particles having an average particle diameter of 5 to 100nm, which is obtained by a dynamic light scattering method and in which organic groups having an unsaturated bond between carbon atoms are bonded to the surface, and a nitrogen-containing solvent, wherein the amount of the organic groups having an unsaturated bond between carbon atoms bonded to the surface of the silica particles is 0.1 to 2.0/nm 2 per unit area of the surface of the silica particles, the concentration of the silica particles is 25 to 70 mass%, free silanol groups are present on the surface of the silica particles, and the amount of the free silanol groups present per unit area of the surface of the silica particles is 0.4 to 1.2/nm 2 .

Inventors

Hasiwa Kazuya
SUGITA MASATOSHI
SUEMURA NAOHIKO
Front Tian Zhi also
SEKIGUCHI KAZUTOSHI

Assignees

日产化学株式会社

Dates

Publication Date: 20260508
Application Date: 20250603
Priority Date: 20240924

Claims (9)

1. Silica sol comprising silica particles having an average particle diameter of 5 to 100nm, which are obtained by a dynamic light scattering method and which contain an organic group containing an unsaturated bond between carbon atoms bonded to the surface, and a nitrogen-containing solvent, wherein, The amount of the organic group containing an unsaturated bond between carbon atoms bonded to the surface of the silica particles is 0.1 to 2.0/nm 2 per unit area of the surface of the silica particles, The concentration of the silica particles is 25 to 70 mass%, The free silanol groups are present on the surface of the silica particles, and the amount of the free silanol groups present per unit area on the surface of the silica particles is 0.4 to 1.2 per nm 2 .
2. The silica sol according to claim 1, wherein the amount of the alkoxy groups bonded to the surfaces of the silica particles is 0.001 to 0.03 alkoxy groups per unit area of the surfaces of the silica particles per nm 2 .
3. The silica sol according to claim 1, wherein the organic group containing an unsaturated bond between carbon atoms is an organic group containing a phenyl group or an organic group containing a (meth) acryloyl group.
4. The silica sol according to claim 1, wherein the organic group containing an unsaturated bond between carbon atoms is a phenyl group, a phenylaminoalkyl group, a (meth) acryl group, or a (meth) acryloylalkyl group.
5. The silica sol according to claim 1, wherein the nitrogen-containing solvent is an amide-based solvent.
6. The silica sol of claim 1, wherein the nitrogen-containing solvent is dimethylacetamide, dimethylformamide, N-methylpyrrolidone, or N-ethylpyrrolidone.
7. An insulating resin composition comprising the silica sol according to any one of claims 1 to 6 and a nitrogen-containing polymer.
8. The insulating resin composition according to claim 7, wherein the nitrogen-containing polymer is 1 to 100 parts by mass based on 1 part by mass of silica contained in the silica sol.
9. The insulating resin composition according to claim 7, wherein the nitrogen-containing polymer is polyimide, polyamide, polyamic acid, polyamideimide, polyether imide, or polyester imide.

Description

Surface-treated silica sol containing free silanol groups dispersed in nitrogen-containing solvent and insulating resin composition Technical Field The present invention relates to a surface-treated silica sol having free silanol groups dispersed in a nitrogen-containing solvent, and an insulating resin composition containing the silica sol and a nitrogen-containing polymer. Background There is known a method of obtaining an inorganic oxide sol dispersed in an organic solvent such as toluene by reacting an alcohol with hydroxyl groups on the surface of inorganic oxide particles such as silica to introduce alkoxysilyl groups and subjecting the resulting product to an organic surface treatment. For example, patent document 1 discloses a silica sol in which phenyltrimethoxysilane is reacted with a methanol-dispersed silica sol and dispersed in a toluene solvent. Patent document 2 discloses a silica sol obtained by performing a surface treatment with phenyltrimethoxysilane after a solvent substitution of a methanol-dispersed silica sol with acetonitrile to obtain an acetonitrile-methanol mixed solvent-dispersed silica sol. Patent document 3 discloses a silica-based microparticle water dispersion sol containing silica microparticles obtained by modifying the surface of silica microparticles with aluminum. Patent document 4 discloses a silica sol in which aluminum atoms are bonded to the surfaces of silica particles at a predetermined ratio, and an insulating resin composition using the silica sol, wherein the silica sol is a silica sol containing aluminum in which silica particles containing aluminum atoms are dispersed in a nitrogen-containing solvent. Prior art literature Patent literature Patent document 1 Japanese patent laid-open publication No. 2005-200294 Patent document 2 International publication No. 2009-008509 Patent document 3 Japanese patent laid-open publication No. 2011-026183 Patent document 4 International publication No. 2022-097694 Disclosure of Invention Problems to be solved by the invention The inventors of the present invention have further studied and found that it is industrially useful (customizable) to provide a silica sol which can be subjected to additional silane treatment in accordance with the use or the like, and further, it is desired to provide a silica sol (reliability) having a high concentration and excellent storage stability even before the additional silane treatment is performed, and it is found that there is room for further improvement in terms of the possibility of achieving both of such customization and reliability. The present invention aims to provide a silica sol in which silica particles are dispersed in a nitrogen-containing solvent used for mixing with a polyimide-based or polyamide-based polar resin in a state of good compatibility, wherein the silica sol can be additionally subjected to a silane treatment according to the use or the like, and is excellent in storage stability at a high concentration, and has both customizability and reliability. Means for solving the problems The present inventors have conducted intensive experiments to solve the above problems, and as a result, they have completed the present invention. Namely, the gist of the present invention is as follows. [1] Silica sol comprising silica particles having an average particle diameter of 5 to 100nm, which are obtained by a dynamic light scattering method and which contain an organic group containing an unsaturated bond between carbon atoms bonded to the surface, and a nitrogen-containing solvent, wherein, The amount of the organic group containing an unsaturated bond between carbon atoms bonded to the surface of the silica particles is 0.1 to 2.0/nm 2 per unit area of the surface of the silica particles, The concentration of the silica particles is 25 to 70 mass%, The free silanol groups are present on the surface of the silica particles, and the amount of the free silanol groups present per unit area on the surface of the silica particles is 0.4 to 1.2 per nm 2. [2] The silica sol according to [1], wherein the amount of the alkoxy groups bonded to the surfaces of the silica particles is 0.001 to 0.03/nm 2 per unit area of the surfaces of the silica particles. [3] The silica sol according to [1], wherein the organic group containing an unsaturated bond between carbon atoms is an organic group containing a phenyl group or an organic group containing a (meth) acryloyl group. [4] The silica sol according to [1], wherein the organic group containing an unsaturated bond between carbon atoms is a phenyl group, a phenylaminoalkyl group, a (meth) acryl group, or a (meth) acryloylalkyl group. [5] The silica sol according to [1], wherein the nitrogen-containing solvent is an amide-based solvent. [6] The silica sol according to [1], wherein the nitrogen-containing solvent is dimethylacetamide, dimethylformamide, N-methylpyrrolidone, or N-ethylpyrrolidone. [7] An insulating resin composition comprisi