摘要 |
Polyurethanes prepd. by the reaction of a polyisocyanate and an organic polyol are made flame resistant by mixing with 2.5-60 wt. % guanidine carbonate, and opt. blowing agents and other additives. Polyisocyanates may be toluenediisocyanate or diphenylmethanediisocyanate. Polyols can be glycols, triols, polyether- or polyesterpolyols partic. polyoxypropylene, poly(oxypropylene-oxyethylene) polyols with 2 to 4 -OH gps. per mol. and a MW 1000-10,000 or an ethylenically unsatd. polymer modified polyol. The flame resistance of polyurethane is improved considerably. |