Flame-retardant rigid polyurethane foams, compositions intended for manufacturing them and process for manufacturing the foams

摘要

The invention relates to flame-retardant rigid polyurethane foams produced using halogenated polyetherpolyols and at least one blowing agent chosen from 1,1-dichloro-1-fluoroethane and 1,1,1-trifluoro-2,2-dichloroethane in the presence of ethylene glycol. It also relates to compositions intended for their manufacture and to a process for manufacturing them. The rigid foams according to the invention exhibit an improved fire resistance and an improved dimensional stability.