Topcoating composition and film-forming process by use of the same

A topcoating composition prepared by mixing a condensate of an organosilicate represented by the general formula:

• ##STR5## wherein R is the same or different and is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, with an organic coating composition containing, as a resin component, a reactively curable organic resin consisting of a mixture of a hydroxyl group-containing base resin with a polyisocyanate compound curing agent, said condensate having a degree of condensation of 2 to 10, said hydroxyl group-containing base resin having a number average molecular weight of 2,000 to 100,000 and a hydroxyl number of 20 to 200, the hydroxyl group-containing base resin and the polyisocyanate compound being mixed in a ratio between the hydroxyl group-containing base resin and the polyisocyanate compound such that an isocyanate group in the polyisocyanate compound is in the range of 0.6 to 1.5 equivalents based on hydroxyl group in the hydroxyl group-containing base resin, followed by being dried and cured to form a crosslinked organic film, a film formed from said topcoating composition being such that a surface of the film, which has been subjected to an acid treatment, shows a contact angle to water of 70.degree. or less.