| abstract |
The invention provides a stable water-repellent inorganic powder which is substantially freed from the re-dissolution of a silicon compound used in the surface treatment of the powder in an organic solvent whether the organic solvent is polar or nonpolar. A water-repellent inorganic powder which is surface-treated with a silicon compound, wherein the silicon compound is one having a group reactive with the inorganic powder and when the water-repellent inorganic powder is dispersed in any of polar organic solvents and nonpolar organic solvents, the retention of the silicon compound is 90% or above. The silicon compound is preferably methylhydrogensilicone oil, alkoxy-modified silicone oil, amino-modified silicone oil, or the like. The compound is used as an aqueous emulsion, which emulsion further contains a surfactant of sorbitan fatty acid ester type, polyoxyethylene sorbitan fatty acid ester type, or the like. |