A process for the preparation of color - and / or effect paint systems with the use of self-crosslinking graft copolymers of polyurethanes, and to novel self-crosslinking polyurethanes and their graft copolymers

摘要

A process for the preparation of color - and / or effect, e of the multicoat paint systems according to the wet in wet - - - a method in which an aqueous basecoat material applied, the at least one graft copolymer containing(A) at least one (meth) acrylate copolymer and(B) at least one polyurethane,, wherein the graft copolymer can be produced by(1) at least one hydrophilic or hydrophobic self-crosslinking polyurethane (b) having a statistical average at least one terminal and / or at least one pendant olefinically unsaturated group and at least a blocked isocyanate group per molecule is dispersed in an aqueous medium, after which(2), a mixture of at least one monomer (a1) with at least one isocyanate-reactive functional group and at least one monomer copolymerizable with this (a2) in the presence of the polyurethane (b) or of the polyurethanes (b) in emulsion copolymerized by;and the resulting basecoat film with a powder slurry - clearcoat, after which the basecoat film and the clearcoat are cured together; new hydrophilic or hydrophobic self-crosslinking polyurethanes (b) with at least one pendant and / or at least one terminal olefinically unsaturated group and at least one pendant blocked isocyanate group per molecule and graft copolymers on the basis of these polyurethanes (b) as well as their use.