In Japanese Examined Patent Publication No. 15104/1986, there is reported an anti-corrosive coating composition comprising (a) an acrylic copolymer consisting of (1) a monomer represented by the formula: ##STR1## wherein R1 is hydrogen or methyl group, R2, R3 and R4 are same or different and each is an alkyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 12, (2) styrene, and (3) (me