Polyisocyanates containing acylurea groups, a process for their production and their use

摘要

The present invention relates to a process for preparing polyisocyanates containing acylurea groups by reacting isocyanates corresponding to formula (I) R-(NCO)_n, (I) wherein R represents an n-valent linear or branched aliphatic group or cycloaliphatic group having 4 to 30 carbon atoms or an aromatic group having 6 to 24 carbon atoms and n is 1, 2, 3 or 4, with aliphatic and/or aromatic carboxylic acids in the presence of a metal salt catalyst at a temperature of 20 to 220° C. The present invention also relates to the reaction products (polyisocyanates) prepared by this process and to their use as binders for polyurethane coating compositions.