| 摘要 |
<p>Mouldings and coatings are obtd. by reacting (i) a polyol mixt. with an OH-function >3 (3.2-3.8) esp. 3.3-3.7, and an average mol.wt. of 180-400, esp. 220-300, with (ii) a polyisocyanate mixt. composed of 3-isocyanatomethyl-3,5,5-trimethyl-cyclo hexylisocyanate and the urea deriv. contg. an isocyanate gp. thereof, in a esp. mol. ratio of 0.5-6:1, pref. 0.7-4:1, at 20-100 degrees C; in the presence of a catalyst, suitably organo-metallic cpds., tert amines, etc. (i) and (ii) are used in such amts. that the OH/NCO ratio is 1-0.8-1.2, pref. 0.95-1.05. The mechanical and physical props. of the mouldings or coatings are advantageously improved by post-heating at 100-180 degrees C. The highly crosslinked prods. have excellent mechanical props., good electrical props. and weathering props., enabling them to be used externally. They may be transparent or may contain fillers.</p> |
