FOAMING SYSTEM FOR CLOSED-CELL RIGID POLYURETHANE FOAM

摘要

This invention relates to the use of a C2-6 polyfluorocarbon compound containing non chlorine or bromine atoms as physical blowing agent in the preparation of rigid, closed-cell, polymer foams. Use of such blowing agents in the prepara- tion of polyurethane foam provides for a product in which the loss in therma l insulationperformance with time compared to products prepared in absence of such blowing agent is reduced.