Process for the preparation of carbodiimide-isocyanurate foams employing quaternary boron salts as catalysts

Claim 1

A process for the preparation of foams characterized by carbodiimide and isocyanurate linkages comprising catalytically condensing an organic polyisocyanate in the presence of a catalytically sufficient amount of a quaternary boron salt prepared by the reaction at a temperature of from 25° C. to 200° C. for a period of one half hour to 24 hours of (a) boric acid or an alkyl ester thereof with (b) an organic compound having a reactive hydrogen atom on a nitrogen atom selected from the group consisting of primary and secondary alkyl amines having from 1 to 4 carbon atoms in the alkyl chain, alkylenediamines, polyalkylene polyamines and primary and secondary alkanolamines having from 2 to 4 carbon atoms in the alkanol chain or mixtures of the above organic compounds with an alcohol having from 1 to 6 carbon atoms and from 1 to 3 hydroxyl groups or a phenol having from 6 to 20 carbon atoms and from 1 to 3 hydroxyl groups, and (c) an alkali metal, alkali metal oxide or an alkali metal hydroxide employing a mole ratio of (a):(b):(c) of from 1:2:1 to 1:4:1.