Marine paint

Claim 1

A top coat paint for ships' hulls comprising (a) a film-forming copolymer containing from more than 50 up to 80 percent by weight of units of at least one tri-organo tin salt of an olefinically unsaturated carboxylic acid having the general formula R 3 SnOOCCR' = CHR" where R is the same or different alkyl radical containing up to 8 carbon atoms, an aryl group or an aralkyl group, R' is hydrogen or a methyl group and R" is hydrogen or a --COOSnR 3 group, the balance of the copolymer being units of at least one olefinically unsaturated comonomer, (b) a substantially water insoluble metalliferous pigment capable of reacting with sea-water to form a water-soluble metal compound, and (c) a hydrophobic organic retarder for retarding the rate of ion exchange between sea-water and the copolymer (a), which retarder (i) has a solubility in sea-water at 25° C. of not more than 5 parts per million by weight and is miscible with the copolymer (a), (ii) has a negligible vapour pressure at 25° C., and (iii) is present to the extent of 5 to 120 percent by weight based on the weight of the tri-organo tin ion content of the copolymer (a), and (d) an organic solvent for components (a) and (c).