Process for preparing double metal cyanide catalysts

US12370535B2 · kind B2 · utility

Assignee

• Covestro Deutschland AG · DE

Inventors

• Joerg Hofmann · Krefeld, DE
• Maria Gleixner · Kempen, DE
• Thomas Asma · Tönisvorst, DE

Key dates

• Filing date: Feb 17, 2021
• Grant date: Jul 29, 2025
• Expiry date: Jun 19, 2042

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G65/2663
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for preparing a double metal cyanide (DMC) catalyst, comprising the reaction of an aqueous solution of a cyanide-free metal salt, an aqueous solution of an alkaline metal cyanide salt, an organic complex ligand and optionally a complex-forming component, wherein the metal cyanide salt is one or more compound(s) and is selected from the group consisting of potassium hexacyanocobaltat(III), potassium hexacyanoferrate(II), potassium hexacyanoferrate(III), calcium hexacyanocobaltate(III) and lithium hexacyanocobaltat(III), where the organic complex ligand is one or more compound(s) and is selected from the group consisting of dimethoxyethane, tert-butanol, 2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol, ethylene glycol mono-tert-butyl ether and 3-methyl-3-oxetanemethanol, and wherein the alkaline metal cyanide salt used has an alkalinity by the titration method disclosed in the Experimental of between 0.700% and 3.000% by weight of sodium hydroxide (NaOH) based on the total weight of the alkaline metal cyanide salt used. The invention further relates to double metal cyanide (DMC) catalysts obtainable by the process according to the invention and…