| 摘要 |
<p>An aq. polyurea dispersion comprises polyureas contg. 0.5-25 wt.% en-urea gps. (calculated as -NH-C(O)-N-, MW 57) obtd. by the reaction of an isocyanate gp. with an aldimine gp. prepd. from a cyclic polyamine contg. (cyclo)aliphatically bound amino gps., wherein the polyureas are based on the reaction prod. of: (i) an NCO prepolymer contg. 0.5-25 wt.%, based on the wt. of the polyurea, of such en-urea gps.; with (ii) an isocyanate-reactive component contg. amino gps. Also claimed is prepn. of such a dispersion comprising: (1) preparing an NCO prepolymer by reacting an organic polyisocyanate (a) with an aldimine (b) and/or a high mol. wt. polyol (c) and opt. an NCO-reactive cpd. (d) contg. hydrophilic gps., and (2) reacting the prepolymer with (b) or (d) contg. amino gps. either prior to, during or after dispersing the prepolymer in water, where (a) is present in an amt. sufficient to incorporate 0.5-25 wt.% of the en-urea gps. Alternatively, the prepolymer is prepd. by reacting (a) with (b) and opt. (c) and/or (d) contg. hydrophilic gps., and then reacting the prepolymer with (d) contg. amino gps.</p> |
