Binder composition, coating composition containing this binder, production and use thereof

A binder composition suitable for coating compositions, which binder comprises

• A) 25 to 75 wt % of one or more resins containing carboxyl groups, with a number average molecular weight (Mn) of 500 to 10000 g/mol and an acid value of 15 to 200 mg KOH/g,
• B) 25 to 75 wt. % of one or more polyethers, polyesters, polyether-polyesters and/or (meth)acrylic copolymers, each containing groups of the formulas:
• ##STR2## and having at least one .alpha.,.beta.-unsaturated group and at least one epoxy group per molecule;
• wherein R.sub.1, R.sub.2 and R.sub.3 are each independently hydrogen or an unbranched or branched alkyl with 1 to 10 carbon atoms;
• wherein the .alpha.,.beta.-unsaturated groups and epoxy groups are present in a numerical ratio of 20:80 to 80:20, with a number average molecular weight (Mn) of up to 10000 g/mol, said molecular weight applies to all of the polyethers, polyesters, polyether-polyesters, and (meth) acrylic copolymers,
• C) 0 to 60 wt. % of one or more polyols with at least two hydroxyl functional groups per molecule,
• D.sub.1) 0 to 20 wt. % of one or more melamine resins,
• D.sub.2) 0 to 40 wt. % of one or more capped polyisocyanates, wherein the sum of the weight percentages of components A), B), C), D.sub.1) and D.sub.2 is 100 wt. %, together with
• E) 0 to 10 wt. % of one or more catalysts to catalyze the reaction of the carboxyl and epoxy groups, related to the sum of the weights of components A) to D.sub.2, and
• F) 0.1 to 10 wt. % of one or more thermally or photochemically activated initiators, related to the total weight of component A) and B).