GB1054788A - - Google Patents

Abstract

1,054,788. Polyurethanes and polyols. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. Sept. 7, 1964 [Nov. 13, 1963], No. 44808/63. Headings C3C and C3R. Flexible polyurethane foams are prepared by reacting an organic polyisocyanate and a polyether polyol which is the condensation product of an organic compound containing at least two replaceable hydrogen atoms with ethylene oxide and propylene oxide, the polyol having an hydroxyl equivalent weight of at least 700 and an oxyethylene radical content of 5-25% by weight of the oxyalkylene radical content, the oxyethylene radicals being essentially non- terminal whereby the polyol contains essentially secondary hydroxyl groups and whereby polyol is prepared by reacting an organic compound containing replaceable hydrogen atoms with ethylene or propylene oxides. sequentially or in admixture, to form an intermediate adduct which is then reacted with propylene oxide. The polyurethanes may be prepared by the oneshot method in which water is present as a coreactant. In addition to water an auxiliary foaming agent comprising a volatile liquid, e.g. a halogenated hydrocarbon, may be present. The replaceable hydrogen may be in hydroxyl, phenol, carboxylic acid, amine, hydrazine, imine, amide, guanidine, sulphonamide, urea, thiourea, mercaptan, thiophenol or thiocarboxylic acid groups. The examples refer to the use of glycerol. Hydroxyl equivalent weight is the average molecular weight of the polyol divided by the number of hydroxyl groups in the polyol.