Preparation of amino polyols

Abstract From the Canadian patent

An improved method is disclosed for producing amino polyols useful in preparing polyurethane foams. The improvement concerns charging ammonia, a primary amine or a secondary amine to the reaction vessel at the end of the oxide digestion step. The amine or ammonia scavenges the residual oxide and the resulting alkanol amine becomes one of the components of the polyol mixture. Alkanol amines are beneficial components of urethane polyols. In prior art industrial practice residual oxide, is vented to a scrubber system and then stripped to a low concentration.