Blowing agent and process for preparing polyurethane foam

摘要

The use of 1,1-difluoroethane (HFC-152a) and dimethyl ether, optionally with up to 50 mole % of water, as the blowing agent is disclosed as an efficient route to a rigid, closed-cell polyurethane or polyisocyanurate foam of improved cell structure and excellent insulation properties.