Aqueous coating agent based on polyurethane dispersions

摘要

Water-dilutable hydroxy-functional polyurethanes (I) comprising polyamide units are new. Water-dilutable hydroxy-functional polyurethanes (I) comprising polyamide units of formula (II) are new. -O-R 2-CO-NH-R 1-NH-CO-R 2-O- (II) R 1a 2-18C aliphatic or alicyclic group; R 2a 3-5C aliphatic group. Independent claims are also included for: (1) solutions comprising 50-90 wt.% (I) and 10-50 wt.% organic solvent, optionally with conventional paint additives; (2) dispersions comprising 35-70 wt.% (I) and 30-65 wt.% water, optionally with organic solvents and conventional paint additives; (3) aqueous coating materials comprising a dispersion as above and a crosslinker; (4) multilayer structure with a clear or topcoat lacquer, comprising (I) as the topmost layer.