METHOD FOR PRODUCING BLOCKED POLYISOCIANTS, THEIR APPLICATION FOR COATINGS AND / OR POLYURETHANE PLASTICS AND ONE-COMPONENT SYSTEM OF HOT SUSHI

摘要

Production of blocked polyisocyanates comprises (A) reacting polyisocyanates with biuretization agents optionally in presence of catalysts to give in the blocked end-product 5-45 equivalent % of biuret groups based on the total of free and blocked NCO groups; (B) optionally converting the free NCO groups using NCO-reactive compounds and/or catalysts; and (C) blocking =95 mol. % of the remaining free NCO groups with a (cyclo)aliphatic amine. Production of blocked polyisocyanates comprises (A) reacting polyisocyanates with biuretization agents optionally in the presence of a catalyst to give in the blocked end-product 5-45 equivalent % of biuret groups of formula (I) based on the total of all free and blocked NCO groups; (B) optionally further converting the free NCO groups with the aid of isocyanate-reactive compounds and/or catalysts; and, finally, (C) blocking the remaining free NCO groups to an extent of =95 mol.% with an amine of formula R 1R 2NH where R 1 and R 2 = 1-12C aliphatic or cycloaliphatic alkyl. [Image].