POLYUREAURETHANE SOLUTION HAVING CROSSLINKED STRUCTURE AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a polyureaurethane soln. which can retain a stable state of soln. over a long term by reacting a polyisocyanate compd. with a polyol and a polyamine in a solvent contg. or not contg. an alcohol and, when the solvent does not contain an alcohol adding an alcohol to the resultant product. SOLUTION: A polyol compd. having a functionality of 2 is reacted with a diisocyanate compd. in an equivalent ratio of NCO/OH higher than 1 but not higher than 2 in a solvent to give an isocyanate-terminated prepolymer, which is reacted with a diamine compd. having a functionality of 2 in an equivalent ratio of NH2/NCO of 2. The resultant amine-terminated prepolymer is further reacted with a polyamine compd. having a functionality of 3 or higher and a diisocyanate compd. in an equivalent ratio of NCO/NH2 not lower than 0.6 but lower than 1.0. The solvent is required to contain at least 10 wt.% alcohol.