| 摘要 |
<p>Non-cellular polyurethanes from (a) a mixt. of (1) 75-95 wt. % of a polyol from 2-4C alkylene oxide with 2-8 OH gp. contg. aliphatic polyol having in OH number of 30-1200 and (2) 5-25 wt. % novolak resin of formula: (where R is H or 1-3C alkyl, X is H, OH, Cl Br or 1-12C alkyl, n is 1-2, and m is 0-4) (b) polyisocyanate and a catalyst, the polyiso cyanate being used so as to give 0.9-2 NCO gps. per reactive H atom. Novolak gives the polyurethane increased tensile strength, and makes it fire-resistant.</p> |
