| 摘要 |
PURPOSE:To obtain a polyurethane foam excellent in foamability and flexibility and useful for an automobile cushion material, by reacting a specified polyisocyanate compound with a polyol component in the presence of a blowing agent. CONSTITUTION:A polyisocyanate (a) comprising 60-90wt% diphenylemthane diisocyanate containing 5-20wt% 2,4'-diphenylmethane diisocyanate and 40-10wt% polymethylenepolyphenyl isocyanate is reacted with a polyether diol (b) to obtain a polyisocyanate component (A) which is a prepolymer of an isocyanate group content of 20.0-28.0wt%. component A is reacted with a polyol component (B) comprising a polyether polyol having an average MW, per OH group, of 1,500-2,500, an ethylene oxide content of 5-25wt% and an average functionality of 3.8-4.1 in the presence of, optionally, a catalyst, surfactant, filler and other additives.
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