Polymer modified polyamines and a process for their preparation

Polymer modified polyamines having a polymer content of from 1 to 30 wt. % and an aromatic amino group content of from 1 to 12.5 wt. % are produced by hydrolyzing a polyisocyanate prepolymer in an aqueous alkaline medium. The polyisocyanate prepolymer is polymer modified by in situ polymerization of either the prepolymer or the isocyanate used in making the prepolymer with an unsaturated monomer in the presence of a radical forming polymerization catalyst in a manner such that a solution and/or dispersion is formed. The prepolymer is formed from a relatively high molecular weight polyhydroxyl compound, aromatic polyisocyanate, and optionally a chain extender or crosslinking agent. The aromatic polyisocyanate used is from 60-100 wt. % polyisocyanate of the diphenyl alkane series and from 0 to 60 wt. % tolylene diisocyanate. The preferred unsaturated monomer is acrylonitrile containing up to 20 wt. % comonomer. The polymer modified polyamines of the present invention are particularly useful in the production of polyurethanes.