Abstract: In the present invention, a rigid polyurethane foam or polyisocyanurate foam is prepared by mixing an isocyanate with a premix of a polyol, a blowing agent, a reaction catalyst, a foam stabilizer and other additives, in which 1,1,1,3,3-pentafluoropropane is used as the blowing agent in combination with a vapor pressure depressant therefor that includes at least one compound compatible with 1,1,1,3,3-pentafluoropropane.

Abstract: In the present invention, a rigid polyurethane foam or polyisocyanurate foam is prepared by mixing an isocyanate with a premix of a polyol, a blowing agent, a reaction catalyst, a foam stabilizer and other additives, in which 1,1,1,3,3-pentafluoropropane is used as the blowing agent in combination with a vapor pressure depressant therefor that includes at least one compound compatible with 1,1,1,3,3-pentafluoropropane.

Abstract: The present invention provides a polyol composition for hard polyurethane foam in which HFC-245fa is used as a blowing agent and its vapor pressure is suppressed, and a method for producing a hard polyurethane foam. The polyol composition for hard polyurethane foam comprises at least a polyol compound, a blowing agent, a foam stabilizer and a catalyst, which is mixed with an isocyanate component containing a polyisocyanate compound, followed by foaming and curing to form a hard polyurethane foam, and the blowing agent is 1,1,1,3,3-pentafluoropropane (HFC-245fa) and further comprises at least one compatibilizer selected from the group consisting of DMA, NMP, GBL and MPA, and 1,1,1,3,3-pentafluorobutane (HFC-365mfc) in a predetermined ratio.

Abstract: A vapor pressure reducing agent for polyurethane foam, comprising at least one compound represented by the following formula (1): wherein R1, R2 and R3 represent a straight-chain alkyl group or branched-chain alkyl group having 2 to 5 carbon atoms, R1, R2 and R3 may be the same or different, with the proviso that the compound wherein R1, R2 and R3 are all ethyl groups is excluded, the compound having a total acid content of 650 mg KOH or less as measured in accordance with MIL H-19457; and a premix composition for producing polyurethane foam, comprising a polyol, a curing catalyst, 1,1,1,3,3-pentafluoropropane, a foaming stabilizer, and the vapor pressure reducing agent described above.

Abstract: In the present invention, a rigid polyurethane foam or polyisocyanurate foam is prepared by mixing an isocyanate with a premix of a polyol, a blowing agent, a reaction catalyst, a foam stabilizer and other additives, in which 1,1,1,3,3-pentafluoropropane is used as the blowing agent in combination with a vapor pressure depressant therefor that includes at least one compound compatible with 1,1,1,3,3-pentafluoropropane.