Process for the preparation of cellular and non-cellular polyurethane elastomers

Claim 1

A process for the preparation of cellular or non-cellular polyurethane elastomers by reacting organic polyisocyanates, polyether polyols, chain extenders and/or cross-linking agents in the presence of catalysts as well as blowing agents, auxiliaries and additives, wherein polyoxyalkylene polyether polyols with terminal hydroxyethylene groups are used as the polyether polyols said polyether polyols prepared by reacting initiator compounds having molecular weights of 18 to 342 and containing from 2 to 8 Zerewitinoff active hydrogen atoms in the presence of alkaline catalysts selected from the group consisting of alkali metal alkoxides, alkali metal hydroxides and alkaline earth metal hydroxides comprising (a) initially reacting alkylene oxides containing more than 2 carbon atoms in the presence of from 0.01 to 0.25 mole of said catalyst per equivalent of said initiator compound, (b) further reacting the alkylene oxides containing more than 2 carbon atoms in the presence of from 0.10 to 1.0 mole of said catalyst per equivalent of said initiator compound, (c) further reacting the alkylene oxide adduct of step (b) with ethylene oxide at a maximum concentration of 30 weight percent based on the weight of the crude polyether polyol, and (d) removing the alkaline catalyst.