Epoxy resin compositions comprising epoxy and vinyl ester groups

A coating composition, consisting of:

• i) 100 parts by weight of an epoxy resin comprising
• a) the reaction product formed from
• a1) one or more epoxy compounds having at least two epoxy groups being selected from bisphenol A diglycidyl ether, a phenol novolac glycidyl ether, and a cresol novolac glycidyl ether, and
• a2) 0.3 to 0.7 mol of acrylic acid or methacrylic acid or mixtures thereof per mole of epoxy groups,
• as component A;
• b) a solvent comprising vinyl groups as component B selected from the group consisting of butanediol di(meth)acrylate, hexanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate and tripropylene glycol di(meth)acrylate;
• the solvent comprising vinyl groups of component B consisting to an extent of at least 90% by weight of solvents comprising difunctional vinyl groups, based on the sum of all solvents comprising vinyl groups,
• ii) 0.1 to 10 parts by weight of a free radical-forming polymerization initiator,
• iii) 0.1 to 5 parts by weight of a hardener, which is a Lewis acid selected from complexes of BF3 and BCl3 with tertiary amines, and
• iv) optionally a polymerization inhibitor.