VERFAHREN ZUM BESCHICHTEN EINES SUBSTRATES MIT EINER DURCH BESTRAHLUNG HAERTBAREN KOMPOSITION

摘要

A process is disclosed for coating a substrate with a radiation curble coating composition, characterized in that the composition comprises (A) an at least one isocyanate group-containing adduct of (a) an acrylic or methacrylic hydroxy ester with 5 to 20 carbon atoms and (b) a polyisocyanate with 4 to 40 carbon atoms and with 2 to 4 isocyanate groups per molecule, (B) a polyfunctional hydroxy compound having a molecular weight of 178 to 12,000 and a hydroxyl content of 0.5 to 30% by weight in an amount of 0.5 to 1.5 equivalents of hydroxy per equivalent of isocyanate of component A, and (C) a photoinitiator in an amount of 0.1 to 10% by weight of component A. The curing takes place in a first stage by radiation having a wavelength of 90 to 600 nm and in a second stage by reaction of the isocyanate groups of component A with water vapor and the hydroxyl groups of the polyfunctional hydroxy compound.