| 摘要 |
PURPOSE:To produce a polyurethane foam with reduced amts. used of a catalyst and blowing agent by reacting an active hydrogen compd. with a polyisocyanate in the presence of the catalyst, a low boiling halogenated hydrocarbon blowing agent, and an ionic surfactant. CONSTITUTION:A polyurethane foam is produced by reacting 100 pts.wt. active hydrogen compd. (e.g. a polyol with a hydroxyl value of 200-800) with a polyisocyanate in the presence of 50-150 pts.wt., pref. 20-60 pts.wt., blowing agent comprising a low boiling hydrocarbon [pref 1,1-dichloro-2,2,2- trifluoroethane (R-123), 1,1-dichloro-1-fluoroethane (R-141b) or methylene chloride] and, if necessary, 0-10 pts.wt., pref. 1-5 pts.wt., water, an ionic surfactant (pref. an anionic surfactant), and a catalyst. |
