Cold, one-shot prepn. of polyurethane foams - using unmodified diisocyanate and specific polyether polyols

摘要

Flexible or semi-rigid polyurethane foams with(out) integral skin are prepd. cold by the one-shot method, by moulding a free expansion, by reacting polyisocyanats (I) polyether-polyols (II) a blowing agent and a catalyst, the reaction being characterised by (I) being a pure, ie. unmodified diisocyanate, and (II) being prepd. by oxyalkylation of polyalcohol(s) of functionality =4, alternately or mixed, by alkylene oxide(s) to give (II) with an OH value =37, and having a terminal ethylene oxide content 10% by wt. the majority of the OH gps. being primary. The process allows the prepn. of industrially exploitable polyurethane foams by the cold, one-shot method, which has not been possible in prior art. The prod. has characteristics approximately those of latex.