| 摘要 |
1480949 Polyurethane foams BASF WYANDOTTE CORP 2 Dec 1974 [3 Dec 1973] 52014/74 Heading C3R A process for the preparation of a flexible polyurethane foam comprises reacting : (a) a polyoxyalkylene ether polyol or polyoxyalkylene ether polyol blend which has an equivalent weight of at least 100 and in which at least 17% of the hydroxyl groups are primary OH groups, (b) an aliphatic polyisocyanate or an aromatic polyisocyanate having at least 2 NCO groups attached to the same aromatic ring, (c) water, in the presence of (d) a surfactant and (e) an organic stannous salt as the sole catalyst. The foams generally have a density of 1-2 1bs./cu. ft. Suitable catalysts are stannous acetate, stannous butyrate, stannous laurate, stannous octoate, stannous stearate, stannous oleate and stannous linoleate. Suitable polyisocyanates are polymethylene diisocyanates and toluene diisocyanates. The NCO/OH ratio is generally from 0À9 : 1 to 1À5 : 1. Suitable surfactants are polysiloxanes, oxyalkylated polysiloxanes and alkylene oxide adducts of organic compounds containing reactive hydrogen atoms. Optional ingredients include fillers, e.g. aluminium silicate, calcium silicate, magnesium silicate, calcium carbonate, barium sulphate, calcium sulphate, carbon black and silica; and inorganic and organic pigments, e.g. TiO 2 , ZnO, iron oxides, antimony oxide, chrome green or yellow, iron blue siennas, molybdate oranges, para reds, benzidine yellow, toluidine red, toners and phthalocyanines. In the examples flexible foams having improved load-bearing properties are prepared from the following formulations: 65/35 or 80/20 2,4-, 2,6-toluene diisocyanate, water, oxyalkylated polysiloxane, stannous octoate or stannous oleate and as the polyol component either (A) a glycerol-propylene oxide-ethylene oxide adduct (e.g. wt., 1000, primary OH content 50%) and/or (B) a trimethylolpropane - propylene oxide - ethylene oxide adduct (e.g. wt. 2200, primary OH content 100%), or a blend of (C) a glycerol-propylene oxide adduct (e.g. wt. 1000, primary OH content 5%) with either polyol (A) or with (D) a glycerol-propylene oxide ethylene oxide adduct (e.g. wt. 1000, primary OH content 100%).
|
