Patent ID: 6335378
Filing Date: 2002-01-01
Classification: C08J

Abstract:
Process for preparing rigid polyurethane or urethane-modified polyisocyanurate foams comprising the step of:reacting an organic polyisocyanate with a polyfunctional isocyanate-reactive component, said component comprising from 10 to 75 wt %, relative to the total isocyanate-reactive components, of an amine initiated polyether polyol, in the presence of 0.2-5% by weight, relative to the total weight of isocyanate-reactive components, of water, and a physical blowing agent mixture containing 1,1,1,3,3-pentafluoropropane and isopentane and/or n-pentane wherein the mole ratio of 1,1,1,3,3-pentafluoropropane/iso- and/or n-pentane is between 10/90 and 40/60, to form a foam, the foam having an initial thermal conductivity after forming the foam of below 23 mW/mK.