PRODUCTION OF WATER-BASE POLYURETHANE-POLYUREA DISPERSION

PURPOSE:To obtain the subject dispersion excellent in water resistance by adding a mixture comprising water, a polyamine, and a base to a specific carboxylated isocyanate-terminated urethane prepolymer to form a emulsion and reacting the emulsion with an aziridine. CONSTITUTION:This water-base dispersion is obtd. by adding a mixture comprising water, a polyamine (of which 60mol% or higher is hydrazine), and a base as the neutralizing agent (e.g. NaOH in an amt. of 80mol% of the carboxyl groups of a urethane prepolymer which will be mentioned below) to a carboxylated isocyanate-terminated urethane prepolymer obtd. from an arom. polyisocyanate (e.g. tolylene diisocyanatte), a polyhydroxy compd. (e.g. polyethylene adipate), and a carboxylic compd. (e.g. dimethylolpropionic acid) to form an emulsion and, after the completion of emulsification, reacting the emulsion with a compd. having at least two aziridinyl groups in the molecule (e.g. 1,6- hexamethylenediethyleneurea).