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:
Apr. 28, 2026
Filed:
Jul. 02, 2021
Evonik Operations Gmbh, Essen, DE;
Jens Hildebrand, Johannesberg, DE;
Annegret Terheiden, Alpen, DE;
Natalia Hinrichs-Tontrup, Alzenau, DE;
Walter Pfefferle, Langgoens, DE;
Evonik Operations GmbH, Essen, DE;
Abstract
A method of hydrolyzing a polyurethane is disclosed in which the polyurethane is contacted with water in the presence of a strong inorganic base having a pKvalue at 25° C. of below 1, and a catalyst that is a quaternary ammonium salt containing an ammonium cation containing 6 to 14 carbon atoms if the ammonium cation does not contain a benzyl residue or containing 6 to 12 carbon atoms if the ammonium cation contains a benzyl residue. An active hydrogen containing polyether and an organic polyamine can be recovered in high yields. The present method finds use in polyurethane recycling.