MANUFACTURE OF FOAM

PURPOSE:To obtain a highly air-permeable foam free from surface skin, by mold injection, at a specific packing rate, of a stock solution prepared by regulating the final density after expansion of a blend of organic polyisocyanate and a specific polyol in the presence of specific catalyst, foam stabilizer and foaming agent. CONSTITUTION:A blend comprising (A) an organic polyisocyanate and (B) a polyol at least part of which is a polymer from ethylenic unsaturated monomer and polyether (or polyester) polyol is subjected, in the presence of (1) as a catalyst, 0.02-0.2pts.wt. per 100pts.wt. of said polyol, of a tertiary amine, a resinification promotor and 0.2-0.9pts.wt. of a second tertiary amine, a foaming accelerator, (2) as a foam stabilizer, a silicone compound of formula (A is polyoxyethylene with an average molecular weight 100-700, etc.; x is 3-20; y is 3-30; R is H, etc.), and (3) a foaming agent, to expansion in a mold (with injection at a packing rate 120-300% of the stock solution capable of providing the final density 0.02-0.04g/cm after free expansion, made up of the above components and ingredients), thus obtaining the objective foam.