Process for rigid polyurethane foams using a blowing agent containing 1,1,1,3,3-pentafluoropropane and isopentane and/or n-pentane

摘要

A process for preparing rigid polyurethane or urethane modified polyisocyanurate foams comprises reacting an organic polyisocyanate with a polyfunctional isocyanate reactive component in the presence of water and a physical blowing agent mixture containing 1,1,1,3,3-pentafluoropropane and isopentane and/or n-pentane. The mole ratio of 1,1,1,3,3-pentafluoropropane/isopentane and/or 1,1,1,3,3-pentafluoropropane/n-pentane is between 1-99 and 40-60.