Method for producing polyether carbonate polyols

US10364323B2 · kind B2 · utility

Assignee

• Covestro Deutschland AG · DE

Inventors

• Thomas Ernst Müller · Aachen, DE
• Christoph Gürtler · Cologne, DE
• Michael Pohl · Villach, AT
• Muhammad Afzal Subhani · Aachen, DE
• Walter Leitner · Aachen, DE

Key dates

• Filing date: May 24, 2016
• Grant date: Jul 30, 2019
• Expiry date: Aug 13, 2036

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G65/2663
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

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.