| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a rigid polyurethane foam having homogenized, minified foams and excellent in insulation efficiency using pentane which does not bring about environmental destruction. SOLUTION: The method of manufacturing the rigid polyurethane foam reacting raw materials composed of at least two constituents (a), (b) of a polyisocyanate constituent (a) and a polyol constituent (b) comprising a polyol, the pentane, water, a catalyst, a foam stabilizer and other auxiliary agents comprises the steps of: making a homogenous gas/liquid dispersing system by introducing not less than 5 vol% and less than 50 vol% of a gas into at least one of the polyisocyanate constituent (a) and the polyol constituent (b); and thereafter reacting both constituents (a), (b), whereby bubbles in each of the constituents are minified in a short time, and the obtained foams are also minified and homogenized so that the heat conductivity decreases. COPYRIGHT: (C)2008,JPO&INPIT |
