Varmehærdelige overtrækmasser

Heat-curable, epoxide-free coating materials (I) for coating powders with a matt surface, consists of a dry mixt. of at least two coating powders based on COOH-terminated polyester resins (a) with an acid no of 20-200 (pref 20-120) mg KOH/g and a Tg of at least 40 degrees C, and beta -hydroxyalkyl-amides (b) with at least 2 beta -hydroxyalkylamide (b-OHAA) gps/mol and/or mixts of di- and poly-functional b-OHAA cpds, and opt. other conventional additives, where the various coating powders differ w.r.t. the no of COOH and/or b-OHAA gps. per mol. Also claimed are: (i) a process for the prodn of (I) from separate mixts. of (a) and (b), opt. with additives, pref. pigments, fillers, wetting agents, flow improvers, degassing agents, or thermal or UV stabilisers etc. by melt extrusion at 80-130 degrees C, cooling, milling, and sieving to a particle size of less than 90 mu m, and then combining the separate mixts. in an intensive mixer; (ii) coating materials obtd. by this process; and (iii) protective coatings produced from these materials.