摘要 |
A method for manufacturing polyurethane foam by mixing (a) polyisocyanate, (b) polyol, (c) blowing agent, (d) catalyst and, as required (e) surface active agent, filler, or other such additive, the said method being characterized in that the polyisocyanate (a) is a prepolymer with isocyanate end groups produced from a polyester polyol and a blended polyisocyanate component comprising 45-95 weight % of diphenylmethane diisocyanate and 55-5 weight % of a polymethylene polyphenyl polyisocyanate with a functionality of 3 or more. |