Wäßrige Überzugsmittel für elastische Einbrennlackierungen

摘要

Heat-crosslinkable, aqueous coating compositions which contain, as binder, a combination of a) a water-soluble or -dispersible polyol component with b) a water-soluble or -dispersible polyisocyanate component containing blocked isocyanate groups, made from b1) a polyisocyanate mixture having a mean NCO functionality of from 2.5 to 3.5 comprising (i) at least 15% by weight of a diisocyanate component and (ii) tri- and/or higher-functional polyisocyanates, b2) blocking agents for isocyanate groups, and b3) at least one aliphatic monohydroxycarboxylic acid, and optionally conventional auxiliaries and additives, and the use thereof for coating metallic substrates with stoving finishes (baking finishes).