| abstract |
[Problem] To provide: a silica sol dispersed in a nitrogen-containing solvent; and a silica-compounded resin composition, particularly an insulating resin composition, with which a nitrogen-atom-containing polymer has been compounded. [Solution] A silica sol in which aluminum-atom-containing silica particles having an average primary particle diameter of 5–100 nm are dispersed in a nitrogen-containing solvent, wherein aluminum atoms are bonded to the silica particle surfaces in a ratio of 800–10000 ppm/SiO2 expressed in terms of Al2O3. A silane compound or a hydrolyzate thereof is bonded in the silica particles. The nitrogen-containing solvent is an amide-based solvent. The nitrogen-containing solvent is dimethylacetamide, dimethylformamide, N-methylpyrrolidone, or N-ethylpyrrolidone. An insulating resin composition containing the silica sol and a nitrogen-containing polymer. The nitrogen-containing polymer is a polyimide, a polyamide, polyamic acid, a polyamideimide, a polyetherimide, or a polyesterimide. An insulated and sheathed conductor wire that has been insulated and sheathed using the insulating resin composition. |