| 摘要 |
1277531 Polyurethane foams FARBENFABRIKEN BAYER AG 3 Sept 1970 [6 Sept 1969] 42195/70 Headings C3C and C3R [Also in Division C2] Polyurethane foams are prepared by reacting an organic polyisocyanate a compound which contains at least two active hydrogen atoms and a blowing agent in the presence of a 6-hydroxychroman of the general formula wherein R 1 is a hydrogen atom or a C 1-9 alkyl, cycloalkyl or aralkyl radical and R 2 , R 3 , R 4 and R 5 represent a hydrogen atom or a C 1-6 alkyl group. The hydroxy chromans are used suitably in admixture with organic esters of phosphorous acid, phosphines and/or sulphides. Conventional polyisocyanates, active hydrogen-containing compounds, blowing agents, catalysts and surfactants may be used. In a typical example a foam is produced from a mixture of a branched polyether, water, triethylene diamine, stannous octoate, a polyether-polysiloxane, toluylene diisocyanate and 2,2 - dimethyl - 6 - hydroxy chroman. |
