| abstract |
RIGID POLYURETHANE FOAM AND ITS PRODUCTION PROCESS. The present invention relates to a rigid polyurethane foam formed from the reaction product at an isocyanate index of about 160 or less, a polyisocyanate, a polyol component containing an aromatic polyester polyol and a sucrose-initiated polyether polyol, in addition to a flame retardant component produced from a combustion modifying agent, in the presence of a hydrocarbon or hydrofluorocarbon blowing agent. The polyurethane foam of the invention contains, based on the total weight of the foam, at least about 3 wt% chlorine, about 1 wt% to about 2 wt% bromine and less than about 1 wt% phosphorus and exhibits satisfactory properties, satisfactory processing and satisfactory adherence to metal while meeting the flammability requirement of ASTM E-84 Class 1. |