POLYURETHANE FOAMS

1339441 Polyurethane foam DUNLOP HOLDINGS Ltd 2 June 1971 [19 June 1970] 30000/70 Heading C3R Flexible flame resistant polyurethane foam is prepared by reacting tolylene diisocyanate with a polymeric polyol in a foam forming reaction mixture having an isocyanate index #150 and which contains (I) as a foam modifier a substance normally effective as a catalyst for the polymerization of tolylene diisocyanate, and (II) an anti-ageing additive substantially to limit any deleterious effect of I on the foam. Examples of I are alkali metal hydroxides, alkali metal salts of weak inorganic acids, e.g. Na 2 , CO 3 , or alkali metal salts of organic acids. I may be present at 0À05-1% by wt. of the polyol component. II may be a halogenated aliphatic phosphate ester, e.g. tris-2,3-dibromopropyl orthophosphate. II may be present at 0.5-4% by wt. of the polyol component. The polyol may be a poly(oxyethylene)poly(oxypropylene) triol having a poly(oxyethylene) content of up to 20% by wt. and containing a substantial proportion of primary OH groups. Alternatively it may comprise a mixture of polyols as disclosed in Specification 1,339,442.