Production manner of coating liquid for silica type coat formation, coating liquid for silica type coat formation, silica type coat formation manner and silica type coat

摘要

PURPOSE:To improve flatness by hydrolyzing at least two kinds of specific alkoxysilane compounds in the presence of water and a catalyst in an organic solvent, applying the resultant silica-based film-forming coating solution onto a substrate and hot curing the formed film. CONSTITUTION:At least two kinds of alkoxysilane compounds, expressed by formula IV (n is 2-4) including tetramethoxysilane, monomethyltrimethoxysilane, etc., expressed by formulas I to III (R' is 1-3C alkyl or phenyl; R is 1-3C alkyl) are hydrolyzed in the presence of water in an amount of 2-4mol water based on 1mol alkoxysilane compounds and a catalyst, such as phosphoric acid, in an organic solvent, such as ethylene glycol diethyl ether, having 17 deg. contact angle to a substrate to provide a silica-based film-forming coating solution, which is then applied onto the substrate, dried at 50-250 deg.C and then hot cured at 300-600 deg.C in N2 atmosphere to form a silica-based film excellent in flatness.