STABLE, COLLOIDAL, AQUEOUS DISPERSIONS OF CROSS- LINKED UREA-URETHANE POLYMERS AND THEIR METHOD OF PRODUCTION

摘要

Mo-2278 PC-073 STABLE, COLLOIDAL, AQUEOUS DISPERSIONS OF CROSS-LINKED UREA-URETHANE POLYMERS AND THEIR METHOD OF PRODUCTION The present invention relates to a process for the preparation of stable, colloidal, aqueous dispersions of cross-linked urea-urethanes which comprises reacting a) an aqueously dispersed, substantially linear, isocyanate-terminated prepolymer having a molecular weight of up to about 25,000 and containing i) about 0 to 120 milliequivalents of ionic groups per 100 grams of prepolymer, and ii) about 0.35 to 10% by weight, based on the weight of the prepolymer, of lateral and/or terminal, hydrophilic ethylene oxide units wherein components(i) and (ii) are present in an amount sufficient to provide a stable dispersion of the prepolymer in the aqueous medium, with b) polyfunctional amine chain extenders having an average functionality between about 2.2 and 6.0. The present invention additionally relates to the aqueous dispersions produced by the above process and to the films, coatings or adhesives produced from these dispersions. PC-073