Method and liquid coating composition for the formation of silica-based coating film on substrate surface

A method for the preparation of a liquid coating composition for the formation of a siliceous coating film comprising, as a uniform solution:

• (A) a partial cohydrolysis-cocondensation product of
• (a) a first hydrolyzable silane compound represented by the general formula
• HSi(OR).sub.3,
• in which each R is, independently from the others, an alkyl group having 1 to 4 carbon atoms or a phenyl group, and
• (b) a second hydrolyzable silane compound represented by the general formula
• Si(OR).sub.4,
• in which each R has the same meaning as defined above, in a molar ratio of (a):(b) in the range from 1:9 to 9:1;
• and
• (B) an organic solvent to dissolve the component (A), which comprises the steps of:
• (1) dissolving the first and second hydrolyzable silane compounds in the organic solvent to form a silane solution;
• (2) admixing the silane solution with water and an acid as a catalyst to form a hydrolysis reaction mixture;
• and
• (3) agitating the hydrolysis reaction mixture to form a solution containing the cohydrolysis-cocondensation product of the hydrolyzable silane compounds and an alcohol as the hydrolysis product of the cohydrolysis reaction.