摘要 |
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.
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