Bayer Aktiengesellschaft

Bayer Materialscience Ag

Thorsten Fechtel

Pieter Ooms

Jörg Hofmann

Bernd Klinksiek

J&ouml;rg Hofmann

Stephan Ehlers

Franz F&ouml;hles

Ulrich Esser

J&uuml;rgen Scholz

Matthias Ruhland

Franz Föhles

The invention provides an improved process for the preparation of double metal cyanide (DMC) catalysts for the preparation of polyether polyols by polyaddition of alkylene oxides on to starter compounds containing active hydrogen atoms, in which aqueous solutions of a metal salt and a metal cyanide salt are first reacted in the presence of an organic complexing ligand and optionally one or more further complex-forming components to form a DMC catalyst dispersion, this dispersion is then filtered, the filter cake is subsequently washed with one or more aqueous or non-aqueous solutions of the organic complexing ligand and optionally one or more further complex-forming components by a filter cake washing and the washed filter cake is finally dried, after an optional pressing out or mechanical removal of moisture.

Method for producing double metal cyanide (DMC) catalysts

The invention relates to an improved method of producing double-metal cyanide (DMC) catalysts for the production of polyether polyols by polyaddition of alkylene oxides to starter compounds containing active hydrogen atoms, in which the DMC catalyst dispersion is produced using a mixing nozzle, preferably a jet disperser. The DMC catalysts produced in this way have an increased activity in polyether polyol production, reduced particle size and narrower particle size distribution.

Process for producing DMC catalysts

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Kö'ln, Germany

Thorsten Fechtel