Abstract: An antifouling coating composition comprising a binder comprising a non-volatile amine and rosin or maleinised or fumarised rosin. The non-volatile amine is preferably an amine of the formula I ##STR1## where R.sup.1 is a monovalent hydrocarbon group derived from a diterpene and R.sup.2 and R.sup.3 are hydrogen, alkyl or aryl, preferably present in a proportion by weight of 9:1 to 1:9 relative to the rosin or maleinised or fumarised rosin.

Abstract: Fouling of a ship's hull is inhibited by an amine of the formula ##STR1## where R.sup.1 is a monovalent hydrocarbon group derived from a diterpene and R.sup.2 and R.sup.3 are each independently hydrogen, an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 12 carbon atoms. The amine acts as a paint binder and as a marine biocide. An antifouling coating composition may comprise a pigment with the said amine as binder. Alternatively an antifouling coating composition comprises as binder an acid-functional polymer whose acid groups are blocked by a monoamine group which forms an organic-solvent-soluble salt of the polymer.

Abstract: A marine anti-fouling paint which is gradually dissolved in sea water comprises a binder which is a resin produced by the reaction of rosin and an aliphatic polyamine containing at least one primary or secondary amine group. The resin contains an amidoamine or imidazoline group. The anti-fouling paint comprises the binder, a marine biocide and a pigment having a solubility in sea water of not more than 10 parts per million by weight. The pigment may itself be the marine biocide of the paint.

Abstract: An anti-corrosive coating composition includes an anti-corrosive pigment component comprising (a) a salt comprising a polyvalent metal cation and an organic polyphosphonic acid containing at least 2 phosphonic acid groups and (b) a corrosion passivator capable of modifying the metal oxide film on the metal to be protected to render it more protective. The ratio of the polyphosphonate salt (a) to the passivator (b) in the coating composition is 1:1 to 50:1 by weight.

Abstract: An anti-corrosive coating composition includes as an anti-corrosive pigment dispersed in a film-forming binder a salt of a polyvalent metal cation and an organic polyphosphonic acid containing at least 2 phosphonic acid groups. The ratio of polyvalent metal cations to phosphonate groups in the salt is at least 0.8/n:1, where n is the valency of the polyvalent metal ion.