US Patent 7737192 Process for producing flexible polyurethane foam

A flexible polyurethane foam is produced by blending a polyurethane raw material containing a polyol, a polyisocyanate, a blowing agent, and a catalyst with an inorganic compound hydrate having a specific gravity of 1.5 to 4.0 and reacting the above polyurethane raw material to effect foaming and curing. The inorganic compound hydrate is preferably an iron sulfate hydrate, a calcium sulfate hydrate, or a magnesium sulfate hydrate. The above inorganic compound hydrate preferably has decomposition temperature of from 100 to 170° C. Then, an increase in exothermic temperature owing to the above foaming and curing is diminished by evaporation of water formed through decomposition of the above inorganic compound hydrate.