[en] Process for preparing binders including reacting A) one or more NCO-functional compounds containing uretdione groups with B) one or more compounds containing groups capable of participating in polymerization reaction with ethylenically unsaturated compounds on exposure to actinic radiation, and contain isocyanate-reactive groups, followed by C) reaction with one or more hydroxyl-containing compounds other than B), wherein at least one of these compounds has an OH functionality of >=2, D) in the presence of one or more compounds containing phenoxide groups, as catalysts, and E) optionally auxiliaries and additives, where the reaction with compounds of component C); proceeds at least proportionally with the formation of allophanate groups and where and including binders containing allophanate groups and groups capable of participating in a polymerization reaction with ethylenically unsaturated compounds on exposure to actinic radiation, and optionally also contain NCO-reactive groups. The binders are used in coating compositions used to coat substrates
