METHOD FOR MANUFACTURING RIGID POLYURETHANE FOAM, RIGID POLYURETHANE FOAM AND IMPACT ABSORBING MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing rigid polyurethane foam capable of being excellently molded by commonly-used molding, having smaller anisotropy, larger effective strain range and higher stress absorption performance, and also to provide rigid polyurethane foam and an impact absorbing material obtained by the method.SOLUTION: A method for manufacturing rigid polyurethane foam 31 includes a step of molding polyurethane foam through foaming and reacting, inside a mold 10, a polyurethane foam formation composition 21 including a polyhydroxy compound, a polyisocyanate compound, a foaming agent, a catalyst and a foam stabilizer. The composition 21 further includes, based on 100 pts.mass of the polyhydroxy compound, 25-70 pts.mass of powder whose average particle diameter is 0.05-10 μm and specific surface area is 0.2-4.5 m/g. The step of molding the polyurethane foam is performed inside the mold 10 that is substantially airtight. Rigid polyurethane foam and an impact absorbing material can be obtained by the method.