Covestro Deutschland Ag

Covestro Intellectual Property Gmbh & Co. Kg

Michael Pohl

Walter Leitner

Thomas Ernst Müller

Christoph Gürtler

Jörg Hofmann

Muhammad Afzal Subhani

Thomas-Ernst MÜLLER

Muhammad-Afzal Subhani

The invention relates to a method for producing polyether carbonate polyols by agglomeration of alkyl oxides and carbon dioxide on carboxylic acid in the presence of a double metal cyanide (DMC) catalyst, wherein one or more carboxylic acids are continually added to the reactor during the reaction, characterized in that the carboxylic acid is at least difunctional and has a pKa value greater than or equal to 1.5, and the adding of the one or more carboxylic acids occurs such that, at any time in the method according to the invention, the molar concentration of unconverted carboxylic acid in the reaction mixture does not exceed a value in the amount of 0.001 mol/g multiplied by the mass of the catalyst used per liter of reaction mixture, specified in grams, and two carboxylic acid groups present in the same molecule are separated from each other at least by one carbon atom. The method further relates to the polyether carbonate polyols obtained according to the invention.

Method for producing polyether carbonate polyols

The invention provides a process for preparing polyether carbonate polyols by addition of alkylene oxides and carbon dioxide onto H-functional starter substance in the presence of a double metal cyanide (DMC) catalyst or in the presence of a metal complex catalyst based on the metals zinc and/or cobalt, wherein (&#x3b3;) alkylene oxide and carbon dioxide are added onto H-functional starter substance in a reactor in the presence of a double metal cyanide catalyst or in the presence of a metal complex catalyst based on the metals zinc and/or cobalt, wherein a reaction mixture comprising the polyether carbonate polyol is obtained, and wherein (&#x3b4;) the reaction mixture obtained in step (&#x3b3;) remains in the reactor or is transferred continuously into a postreactor, wherein the content of free alkylene oxide in the reaction mixture is reduced in each case in the manner of a postreaction, characterized in that a component K is added during the postreaction, component K being selected from at least one compound containing a phosphorus-oxygen-hydrogen group.

Process for preparing polyether carbonate polyols

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Aachen, Germany

Michael Pohl