Manufacturing method null (i) poriisoshianeto and (ii) poly

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a reaction injection molded polyurethane foam, capable of forming the polyurethane molded article having an integral skin structure and a density of 0.2-0.8 g/cm3. SOLUTION: This method for producing a polyurethane foam comprises reacting a polyisocyanate with a polyol mixture through a reaction injection molding method to form the polyurethane foam having an integral skin structure and a density of 0.2-0.8 g/cm3, wherein (a) either or the both of the polyisocyanate and the polyol mixture comprise containing a foaming agent, and the foaming agent contains carbon dioxide in an amount corresponding to 0.05-1.0 wt.% based on the total weight of the polyisocyanate and the polyol mixture; (b) the reactivity of the polyisocyanate with the polyol mixture is so controlled that a rise time for completing the foaming reaction is not longer than 40 sec.