Patent ID: 8373004

Claim:
A process for preparing an isocyanurate group-comprising polyisocyanate mixture of (cyclo)aliphatic diisocyanates, comprising a) reacting monomeric (cyclo)aliphatic diisocyanate (D) with at least one monofunctional or bifunctional alcohol (A) having from 3 to 10 carbon atoms to form urethane groups in the absence of compounds which catalyze this reaction, b) reacting the reaction mixture obtained from a) in the presence of at least one catalyst (K) which catalyzes the reaction of isocyanates to form isocyanurate groups, c) deactivating the catalyst (K) from step b) by adding a catalyst poison (S), d) separating the unreacted (cyclo)aliphatic diisocyanate (D) from the reaction mixture obtained from c) and e) optionally carrying out ozonolysis of the distillation bottoms obtained from d), wherein the catalyst poison (S) is a compound of the formula where R 1 and R 2 are each, independently of one another, hydrogen or C 1 -C 20 -alkyl, C 6 -C 12 -aryl or C 5 -C 12 -cycloalkyl each of which is optionally substituted by aryl, alkyl, aryloxy, alkyloxy, heteroatoms and/or heterocycles, where when X═O or S, R 1 ≠H and R 1 and R 2 together with the group X (CO) NH can also form a 5 to 12-membered ring, with R 1 and R 2 together forming an optionally substituted divalent C 2 -C 9 -alkylene radical which can also be part of an arylene or cycloalkylene radical, Z is oxygen (O) or sulfur (S), X is oxygen (O), sulfur (S), imino (NH) or substituted imino (NR 3 ) and R 3 is C 1 - C 4 -alkyl, where the radical R 1 in the case of the compound (S) has at least one group which is reactive toward isocyanate selected from the group consisting of mercapto, amino, monosubstitued amino and hydroxyl.