METHOD FOR PRODUCING POLYURETHANEUREA IN SOLUTION Russian patent published in 1994 - IPC

FIELD: chemistry, in particular, manufacture of synthetic leather, fibers and coatings. SUBSTANCE: essence of this method resides in admixing polyether with diisocyanate at temperature of 90 to 70 C in undissolved state or at 50 C in the form of 70 to 50 percent solution in dimethylformamide to obtain theoretical values of concentration of isocyanate groups, allowing thus prepared admixture to cool to room temperature, adding prepolymer with water to be taken in amount of at least tenfold molar excess relative to amount of free prepolymer isocyanate groups and in amount not exceeding quantity sufficient to precipitate polymeric solution of dipolar aprotic solvent. EFFECT: greater simplicity.