| abstract |
A process for producing coatings, in which n (I) coating materials are applied to substrates or to uncured, part-cured and/or fully cured coating films present on said substrates, and n (II) the resulting films of the coating materials are cured thermally and with actinic radiation, alone or together with the coating films, n which involves n (1) conducting the actinic radiation cure under an oxygen-depleted atmosphere and n (2) the coating materials comprising n (A) meth(acrylate) copolymers which have an OH number of from 100 to 220 mg KOH/G, a glass transition temperature of −35 to +60° C., a number-average molecular weight of from 1 000 to 10 000 daltons and a mass-average molecular weight of from 2 000 to 40 000 daltons and which contain in copolymerized form an amount of hydroxyl-containing monomers (a) that corresponds to the OH number, of which n (a1) from 20 to 90% by weight are based on (a), 4-hydroxybutyl (meth)acrylate and/or 2-alkylpropane-1,3-diol mono-(meth)acrylate, and n (a2) from 10 to 80% by weight are based on (a), other hydroxyl-containing olefinically unsaturated monomers; and n (B) from 0.2 to 8% by weight of photoinitiators. |