| 摘要 |
<p>The present invention relates to a process for the production of polyurethane ureas from a prepolymer which contains isocyanate groups and a mlxture of hardeners containing amino groups, in the presence of water, and optionally in the presence of solvents, characterized in that the mixture of hardeners comprises compounds corresponding to the following general formulae: H2N-R-NH2 (A) H2N-R-N = R1 (B) and Rl ~ N-R-N - Rl (C) wherein R represents a divalent aliphatic, cycloaliphatlc or araliphatic group having from 2 to 18 carbon atoms and optionally also containing -O- or ? (wherein X represents H, -CH3,-C2H5, -C3H7 or -C4Hg) and R1 represents an aliphatic or cycloaliphatic group such as may be obtained by removal of the oxygen from a ketone or aldehyde having from about 2 to 8, preferably from about 3 to 6, carbon atoms, in which mixture the following molar ratios should be observed: = from about 1:20 to 1:3, preferably from about 1:10 to 1:5; = from about 1 2 to 2:1, preferably from about 1:1.5 to 1.5:1; and = from about 1:1.4 to 1:20, preferably from about 1:1.4 to 1:10.</p> |
