METHOD FOR PRODUCING RIGID PLASTIC FOAM

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a rigid polyurethane foam or a urethane-modified rigid polyisocyanurate foam whereby a normal foam can be obtained even under conditions in which the atmospheric temperature during foam production is low in the case in which HCFC-141b is used as a blowing agent. SOLUTION: There is provided a method for producing a rigid polyurethane foam or a rigid urethane-modified polyisocyanurate foam, which process comprises reacting an active-hydrogen-containing compound with a polyisocyanate compound in the presence of a low-boiling halohydrocarbon blowing agent, wherein the blowing agent used is a mixture of 0.1-30 wt.% HFC-125 and/or HFC-143a with 99.9-70 wt.% HCFC-141b.