Amine prods. contg. urethane and urea gps. prepn.

摘要

The amines (I) are prepd. by reacting (A) isocyanate prepolymer having urethane gps., NCO gps. of the prepolymer being reversibly blocked by a sec. monoamine (II), with (B) at least difunctional amine of mol.wt. 60-500 which has in all at least 2 prim. or sec. amino gps. with splitting off of (II), (A) and (B) being in proportions such that there are more than 1.25 prim. and/or sec. amino gps. of (B) per blocked NCO gp. of (A). More specifically (A) is obtd. by reacting polyether polyol fo mol.wt. 500-10,000 with excess of organic polyisocyanate then reacting residual free NCO gps. with (II). (B) is di prim. diamine contg. at least one cycloaliphatic ring. (II) is such that, after reaction of (A) with (B), it can be removed from reaction mixt. by distn., and is partic. di-isopropylamine (III). Molar ratio of prim. and/or sec. amino gps. of (B) to blocked NCO gps. of (A) is 2-10:1. (A) and (B) are reacted at 60-140 deg.C and liberated (II) is removed by distn..