US Patent 7183331 Method for producing a rigid polyurethane foam

A method for producing a rigid polyurethane foam, which comprises reacting a polyol with a polyisocyanate in the presence of an amine catalyst and a blowing agent, wherein as the amine catalyst, at least one amine compound having at least one type of substituent selected from the group consisting of a hydroxyl group, a primary amino group and a secondary amino group in its molecule, or N-(2-dimethylaminoethyl)-N′-methylpiperazine, is used, and as the blowing agent, 1,1,1,3,3-pentafluoropropane (HFC-245fa) and/or 1,1,1,3,3-pentafluorobutane (HFC-365mfc) is used.