An
antifouling coating composition comprising (A) a silyl ester
copolymer containing constituent units derived from a polymerizable unsaturated
carboxylic acid silyl ester; (B) a
carboxylic acid; (C) a bivalent or trivalent
metal compound; and (D) a dehydrating agent. It is preferred that the component (C) be contained in an amount of 1.2 equivalents or more, in terms of the number of equivalents of
metal as a constituent of the component (C), per equivalent of carboxyl group of the
carboxylic acid (B); that the component (C) be a bivalent
metal compound; and that the component (C) be a compound of at least one metal selected from the group consisting of
zinc,
copper,
magnesium,
calcium and
barium. From the
antifouling coating composition, there can be obtained an
antifouling coating film which exhibits less
cracking tendency, excellent adherence so as to ensure less peeling tendency and desirably controlled
hydrolysis rate so as to be excellent in antifouling performance, in particular, antifouling properties in highly
fouling environment and long-term antifouling properties. With respect to the provided antifouling
coating composition, its storage stability is high, its concentration can be increased, the amount of
solvent used therefor can be reduced, and its applicability is high.