Marine paint

Abstract

A top coat paint for ships' hulls comprising a. a film-forming copolymer containing from more than 50 up to 80 per cent by weight of units of at least one tri-organo tin salt of an olefinically unsaturated carboxylic acid, 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.degree. 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.degree. C. and Iii. is present to the extent of at least 5 per cent by weight based on the weight of the tri-organo tin ion content of the copolymer (a). The top coat paint is an anti-fouling paint which at least preserves the ship's service efficiency during the life of the top coat paint and may in some circumstances lead to an improvement in that efficiency during service. Two or more coats of the paint may be applied successively to the ship's hull the proportion of retarder decreasing from the first applied coat to the last applied coat.

Dependencies are inferred from the claim text.