Process for the trimerization of diisocyanates

摘要: In a process for the trimerization of diisocyanates in presence catalyst comprising quaternary ammonium salts organic acids having formula: ##STR1## wherein X represents same or different radicals selected from group consisting C 1 -C 20 alkyl, 3 8 cycloalkyl, and 2 aralkyl; two taken together with at least one other heteroatom forming hetero-ring three nitrogen atoms through common hetero-atom such that said heterocyclic ring structure is triethylene diamine, methyl quinuclidine, N-methylmorpholine, N-ethylmorpholine, N,N'-dimethylpiperazine; R cycloalkyl aralkyl, R" hydrogen; R+R" form 12 alkyl radical; R' hydrogen, hydroxyl radical, optionally containing CH.sub.(3-b) Z b group, b=1 to OH, improvement comprising: reacting diisocyanate an amount 0.02 0.1% by weight calculated on compound be trimerized temperature ranging 40° 120° C.