Abstract: The present invention relates to an aqueous coating composition comprising at least one first polymer (A) as binder, at least one crosslinking agent (B) and at least one copolymer (C) as second binder, which is obtainable by copolymerization of ethylenically unsaturated monomers in the presence of a polyurethane resin having polymerizable carbon double bonds, the weight ratio of polymer (A) to polymer (C) being greater than 3.0. The present invention further relates to a method for producing a topcoat on a metallic substrate that comprises applying and subsequently curing the coating composition of the invention on a metallic substrate, and also to a metallic substrate coated by the method of the invention.

Abstract: The present invention relates to a use of an aqueous coating composition for applying a topcoat to at least one side of a substrate metal surface coated at least with a primer coat, said aqueous coating composition comprising at least one binder (A) in dispersion or solution in water, at least one crosslinking agent (B), at least one second binder (C) in dispersion or solution in water, and optionally at least one pigment (D), the second binder (C) being a copolymer which is obtainable by copolymerization of ethylenically unsaturated monomers in the presence of at least one polyurethane resin having polymerizable carbon double bonds; to a process for coating a substrate metal surface coated at least with a primer coat, said process comprising at least one step of at least single-sidedly applying the aqueous coating composition as topcoat to the substrate metal surface coated at least with a primer coat; and also to a coated substrate obtainable by this process.