Ductile coating composition of an acrylic polymer having reactive sites and an epoxy resin

A coating composition consisting essentially of a compatible mixture of film-forming constituents in a liquid carrier;

• wherein the film-forming constituents consist essentially of
• a. 60-95% by weight of an acrylic polymer of hard and soft segments and having a number average molecular weight of about 25,000-70,000 determined according to gel permeation chromatography and a glass transition temperature of -20.degree. C. to +60.degree. C. and wherein the acrylic polymer consists essentially of polymerized units of about
• 10-50% by weight of styrene, methyl styrene, methyl methacrylate or acrylonitrile,
• 30-88.5% by weight of an alkyl methacrylate having 2-18 carbon atoms in the alkyl group or an alkyl acrylate having 1-18 carbon atoms in the alkyl group,
• 1-10% by weight of alkoxymethyl acrylamide or alkoxymethyl methacrylamide,
• 0.5-10% by weight of an unsaturated carboxylic acid;
• and
• b. 5-40% by weight, of an epoxy resin having at least one vic epoxy group in combination with at least one hydroxyl group or epoxide group or mixture thereof per polymer chain and having a number average molecular weight of 300 to 20,000 determined as above;
• wherein the film-forming constituents in the fully cured stated have a brittle ductile transition temperature of about -40.degree. C. to +20.degree. C. measured at an elongation rate of 10% per minute on an Instron testing machine using a free film about 2.0-4.0 mils thick of the fully cured composition.