| 摘要 |
PURPOSE: To easily produce and stabilize a coating agent free from variation of coating film characteristics caused by aging by specifying the amount of water used as a raw material for the hydrolysis of an alkoxysilane. CONSTITUTION: The silica-based coating agent is composed mainly of (A) a reaction product produced by hydrolyzing an alkoxysilane of formula Si(OR)4 (R is a 1-8C alkyl) with an acidic catalyst while controlling the maximum temperature to preferably <=40 deg.C and (B) fine particles of a metal oxide. The amount of water to be used as a raw material for the hydrolysis of the alkoxysilane is adjusted to >=4.5mol based on 1mol of the alkoxysilane. The coating agent further contains a diluent component consisting of a cyclic ether, a carboxylic acid ester, an ether, an alcohol or a ketone in an amount of 3-60%. |
