| 摘要 |
<p>PURPOSE:To obtain a coating composition improved in heat resistance, surface hardness, chemical resistance, abrasion resistance, scratch resistance, stain resistance, weathering resistance, storage stability and painting workability, by mixing silica with an organohydroxysilane (partial condensate) and a specified solvent. CONSTITUTION:An organoalkoxysilane (B) is added to an aqueous colloidal silica dispersion (A) which is preferably acidic and contains silica of a mean particle diameter <=150mmum and hydrolyzed to form an organohydroxysilane of the formula (wherein R<1> is a 1-3 C alkyl, vinyl, 3,4-epoxycyclohexylethyl, gamma-glycidoxypropyl, gamma-methacryloxypropyl, gamma-mercaptopropyl or gamma-chloropropyl) and its partial condensate, and the obtained composition is diluted with at least 20wt.% (based on the solvent of the composition) solvent containing at least 20wt.%, based on the solvent of the composition, ethylene glycol monobutyl ether to obtain the title composition comprising solid matter comprising 30-90wt.% silica and 10-70wt.% organohydroxysilane and its condensate and the solvent and having a pH of 2-7.</p> |
