LOW SURFACE ENERGY POLYISOCYANATES AND THEIR USE IN ONE-OR TWO-COMPONENT COATING COMPOSITIONS

摘要

The present invention is directed to a polyisocyanate mixture i) having a monomeric diisocyanate content of less than 3% by weight, ii) having a urethane group content of more than 50 equivalent %, based on the total equivalents of urethane and allophanate groups, and iii) containing fluorine (calculated as F, AW 19) in an amount of 0.001 to 50% by weight, wherein the preceding percentages are based on the solids content of the polyisocyanate mixture and wherein fluorine is incorporated by reacting a) an isocyanate group from a polyisocyanate adduct containing isocyanurate groups and prepared from a monomeric diisocyanate having at least one cycloaliphatic group with b) a compound containing two or more carbon atoms, one or more hydroxyl groups and one or more fluorine atoms to form urethane groups. The present invention is also directed to the use of this polyisocyanate mixture, optionally in blocked form, as an isocyanate component in one- or two-component coating compositions.