| abstract |
PROBLEM TO BE SOLVED: To provide a production method capable of releasing a low-density semi-rigid polyurethane foam excellent in abrasion resistance in a short time. SOLUTION: From a polyol mixture comprising a polyisocyanate and a polyol, a catalyst, a foaming agent, and, if necessary, a crosslinking agent, an internal release agent, a reinforcing agent and other auxiliaries, According to the reaction injection molding method, the density is 0.3 to 0.9 g / cm 3. In the method for producing a polyurethane foam having minute cells of A trifunctional polyether polyol having an active hydrogen equivalent of ~ 1000 and an ethylene oxide content of 5 to 30% by weight in the polyol is contained in an amount of 40% by weight or more, and the average active hydrogen equivalent of all the polyether polyols is 50%; A method for producing a polyurethane foam, which is a polyether polyol component having a viscosity of 200 to 800 mPas / 25 ° C. |