Aqueous two-component polyurethane coating agent, process for preparing the same and its use in a process for applying a multilayered coating of lacquer

摘要

PCT No. PCT/EP94/01991 Sec. 371 Date Dec. 20, 1995 Sec. 102(e) Date Dec. 20, 1995 PCT Filed Jun. 18, 1994 PCT Pub. No. WO95/02005 PCT Pub. Date Jan. 19, 1995The present invention relates to an aqueous two-component polyurethane coating composition comprising A) a water-dilutable polyacrylate resin (A) having an OH number of from 40 to 200 mg of KOH/g, an acid number of from 20 to 100 mg of KOH/g and a glass transition temperature of from -40 DEG C. to +60 DEG C., and B) a polyisocyanate component as crosslinking agent, characterized in that the water-dilutable acrylate resin is obtainable by solution polymerization, in the presence of a polymerization initiator, of at least one monomer which is free of carboxyl groups, at least one monomer which contains hydroxyl groups, at least one vinyl ester of alpha -branched monocarboxylic acids having 5 to 18 carbon atoms per molecule and/or at least one reaction product of acrylic acid and/or methacrylic acid with the glycidyl ester of alpha -branched monocarboxylic acids having 5 to 18 carbon atoms per molecule, at least one monomer containing carboxyl groups and, if desired, other monomers which are essentially free of carboxyl groups, and after the end of the polymerization the resulting polyacrylate resin is at least partially neutralized and is dispersed in water.