AQUEOUS SELF-CROSSLINKABLE POLYURETHANE DISPERSIONS

The present invention relates to polyester polyols (1) carrying at least one keto-type C═O group derived from HO-C(═O)-L1-C(═O)-R1 (1i) or from a derivative thereof, wherein L1 is a linking group and R1 is selected from the group consisting of C1-20-alkyl, C5-8-cycloalkyl, C6-10-aryl and C7-20-aralkyl, to aqueous polyurethane dispersions (PUD) comprising at least one polyurethane (2) carrying at least one keto-type C═O group, water, and optionally at least one organic solvent (4), wherein the at least one polyurethane (2) carrying at least one keto-type C═O group comprises units derived from at least one polyester polyol (1), to aqueous self-crosslinkable polyurethane dispersions (SC-PUD) comprising at least one polyurethane (2) carrying at least one keto-type C═O group, at least one compound (3) carrying at least two keto-type C═O group reactive groups, water, and optionally at least one organic solvent (4), wherein the at least one polyurethane (2) carrying at least one keto-type C═O group comprises units derived from at least one polyester polyol (1), to aqueous self-crosslinkable polyurethane coating composition comprising the aqueous self-crosslinkable polyurethane dispersion (SC-PUD) optionally at least one organic solvent (5), at least one coating composition additive (6), optionally at least one polymer (7) different from the polyurethane (2), and optionally at least one monomer (8) carrying at least one olefinically unsaturated group, to substrate coated with the aqueous self-crosslinkable polyurethane coating composition, and to a process for coating the substrate with the aqueous self-crosslinkable polyurethane coating composition.