Poly:amine with urethane and/or urea gps. prodn. - from isocyanate prepolymer by alkaline hydrolysis and decarboxylation and use in polyurethane prodn.

摘要

In the prodn. of polyamines (I) with urethane and/or urea gps. by hydrolysing cpds. with terminal NCO gps., an NCO prepolymer (II) with urethane and/or urea gps. is converted to the corresp. carbamate (III) in the first stage by introducing into an (5-20 wt.%) aq. alkali hydroxide soln. at 0 to 40 deg.C, using a hydroxide/NCO gp. equiv. ratio of over 1.01:1. In the second stage, (III) is converted to the ammonium salt (IV) by adding excess mineral acid (V), with elimination of CO2, then the excess (V) is neutralised by adding a base and the (I) formed is sepd. from the reaction mixt. in conventional manner. (I) are specified for use in the prodn. of polyurethane plastics by reaction with polyisocyanates, opt. in conjunction with other low and/or high mol.cpds. with NCO-reactive gps. and conventional auxiliaries and additives. Definite aromatic or aliphatic prim. amines are obtd. without harmful side reactions.