The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 29, 2025
Filed:
Feb. 17, 2021
Covestro Deutschland Ag, Leverkusen, DE;
Covestro Deutschland AG, Leverkusen, DE;
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 to the use of DMC catalysts for preparation of polyoxyalkylene polyols.