Catalysts of the oxirane-anhydride reaction

Abstract

This patent describes a method of catalyzing the reaction of organic polybasic acid anhydrides with at least one oxirane which comprises carrying out the reacton in the presence of an effective catalytic amount of a synergistic catalyst mixture comprising an active chromium III tricarboxylate salt haing unoccupied coordination sites and any compound capable of polarizing the carboxlyic acid anhydride to yield a reactive carboxylic acid moiety. Preferred compounds as the cocatalyst member include one or more members selected from the group consisting of the alkyl, aryl, aralkyl, and alkaryl tri-substituted compounds of the following types: quaternary ammonium hydroxides; quarternary phosphonium halides; arsines; amine oxides; sulfoxides; tertiary aminophenols; trihydrocarbon phosphine oxides; trihydrocarbon phosphines; tertiary amines, and combinations thereof, each alone or in combination with a phenol or other reactive promoter such as, carboxylic acids and alcohols; and compounds containing two or more co-catalytic functional groups in the same molecule such as alkyl phosphoramides, alone or in combination with any and all of (1) any of the members, (2) phenols or other reactive promoters. Also the invention pertains to a novel class of mixed catalysts which act synergistically for promoting the reaction of oxirane oxygen groups with curing (crosslinking) or chain extensions. agents.