Patent ID: 7595396

Claim:
A process for preparing a polyisocyanate containing an iminooxadiazinedione group which comprises trimerizing a portion of the isocyanate groups of a polyisocyanate, which does not contain an iminooxadiazinedione group, in the presence of a catalyst containing an anion corresponding to formula (I) (R f ) n —CR′(3 −n )—C(O)O − (I) wherein R f is a perfluorinated C 1 -C 30 radical which is optionally branched, cyclic, and/or unsaturated; R′ are identical or different, optionally heteroatom-containing substituents selected from the group consisting of H, C 1 -C 20 alkyl, and aryl; and n is 1 or 2; and wherein the counterion to the anion of formula (I) is a quaternary ammonium cation or phosphonium cation.