GB777769A - Coating compositions - Google Patents

Abstract

Coating compositions comprise a linear thermoplastic copolymer made from 15 to 80 parts of styrene, 15 to 80 parts of an ester of acrylic or methacrylic acid with an aliphatic alcohol containing not more than 4 carbon atoms and 5 to 10 parts of acrylic or methacrylic acid, for a total of 100 parts, in admixture with from 15 to 55 per cent of a low molecular weight polymeric condensation product of diphenylolpropane with epichlorhydrin having an epoxide content of at least 7.5 per cent, a melting-point not exceeding 75 DEG C. and a Gardner viscosity not exceeding 1.65 poises as a 40 per cent solution in ethylene glycol monobutyl ether, and from 0.5 to 2.0 per cent, on the combined weight of copolymer and condensation product, of a quaternary ammonium hydroxide having at least one alkyl group of from 12 to 18 carbon atoms attached to its nitrogen atom, e.g. dodecyl trimethylammonium hydroxide, dioctadecyl dimethylammonium hydroxide and octadecyl, hexadecyl, tetradecyl and dodecyl benzyl dimethylammonium hydroxides. The compositions may contain a pigment, such as titanium dioxide, and may be used in the form of a solution in a mixture of butanol and xylene. Films made from the compositions yield, on baking, protective coatings which are acetone and soap resistant. The preparation is described of styrene/alkyl acrylate/acrylic acid copolymers by copolymerization in solution in xylene in the presence of a mixture of benzoyl peroxide and tert.-butyl hydroperoxide. Specifications 730,869 and 731,946 are referred to.