Radiation-curing binders and a process for their preparation

摘要

The invention relates to a process for preparing binders which contain 1) allophanate groups, 2) groups that react with ethylenically unsaturated compounds with polymerization on exposure to actinic radiation (radiation-curing groups) and 3) optionally NCO-reactive groups, by reacting at temperatures ≦130° C.A) one or more NCO-functional compounds containing uretdione groups withB) one or more compounds that contain isocyanate-reactive groups and groups that react with ethylenically unsaturated compounds with polymerization on exposure to actinic radiation (radiation-curing groups), and thenC) with one or more saturated, hydroxyl-containing compounds other than B), at least one of these compounds having an OH functionality of ≧2, in the presence ofD) a catalyst containing one or more zinc compounds,the reaction with compounds C) taking place at least proportionally with the formation of allophanate groups.;The present invention also relates to the binders obtained by the process of the invention.