Patent ID: 6855759
Filing Date: 2005-02-15
Classification: C08K

Abstract:
1. An organic resin composition comprising; (a) 100 parts by weight of an organic resin; and (b) from 0.01 to 10 parts by weight of silane-surface-treated fine silica particles wherein said silane-surface-treated fine silica particles comprise primary particles having a particle diameter of from 0.1 to 5 μm, and the fine silane-surface-treated silica particles are obtained by: (A) introducing an R by adding to an aqueous dispersion medium or mixed-solvent dispersion medium comprising the hydrophilic fine silica particle, a trifunctional silane compound represented by formula (II): wherein R 2 represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and the R 4 groups may be the same or different and may each represent a monovalent hydrocarbon group having 1 to 6 carbon atoms, or a partial hydrolysis-condensation product thereof or a mixture thereof, to treat the surfaces of the hydrophilic fine silica particles and form an aqueous hydrophobic fine silica particle dispersion; and (B) introducing an R by converting the dispersion medium of the aqueous hydrophobic fine silica particle dispersion into a ketone solvent to obtain a hydrophobic fine silica particle ketone solvent dispersion, and adding to the hydrophobic fine silica particle ketone solvent dispersion a monofunctional silazane compound represented by formula (III):  R 1 3 SiNHSiR 1 3   (III) wherein the R 1 groups may be the same or different and each may represent a substituted or unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms, a monofunctional silane compound represented by formula (IV): wherein the R wherein the fine silica particles fulfill the following conditions (i) and (ii), (i) when an organic compound which is liquid at room temperature and has a dielectric constant of from 1 to 40 F/m and fine silane-surface-treated silica particles are mixed in a weight ratio of 5:1 and shaken, the fine silane-surface-treated silica particles disperse uniformly in the organic compound; and (ii) the quantity of primary particles remaining as primary particles when methanol is evaporated under heating from a dispersion prepared by dispersing the fine silane-surface-treated silica particles in methanol and thereafter holding the fine silane-surface-treated silica particles at a temperature of 100° C. for 2 hours, is at least 20% based on the quantity of primary particles originally present.