Patent ID: 8742166

Claim:
A process for preparing an isocyanurate-comprising polyisocyanate, the process comprising: at least partly trimerizing at least one (cyclo)aliphatic diisocyanate in the presence of at least one trimerization catalyst comprising a salt, which comprises a tetrasubstituted ammonium cation and an anion of a lactam, wherein the at least one trimerization catalyst is a tetrasubstituted ammonium lactamate of formula (I): R 1 , R 2 , R 3 and R 4 each independently represent a straight-chain or branched optionally substituted C 1 - to C 20 -alkyl group, an optionally substituted C 5 - to C 12 -cycloalkyl group, an optionally substituted C 7 - to C 10 -aralkyl group, or an optionally substituted C 6 -C 12 -aryl group, or two or more of R 1 to R 4 radicals together form a 4-, 5- or 6-membered alkylene chain or, together with nitrogen, form a 5- or 6-membered ring optionally comprising additional nitrogen or oxygen as a bridge member, or together form a multi-membered polycyclic system optionally comprising additional nitrogen, oxygen, or any combination thereof as a bridge member or bridge members; and R 5 represents a divalent C 1 -C 12 -alkylene, optionally interrupted by oxygen, sulfur, a substituted or an unsubstituted imino group, or any combination thereof, or substituted by a functional group, an aryl group, an alkyl group, an aryloxy group, an alkyloxy group, a halogen, a heteroatom, a heterocycle, or any combination thereof.