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:
Jan. 08, 2019
Filed:
Feb. 17, 2017
Covestro Deutschland Ag, Leverkusen, DE;
Joerg Hofmann, Krefeld, DE;
Norbert Hahn, Rommerskirchen, DE;
COVESTRO DEUTSCHLAND AG, Leverkusen, DE;
Abstract
The present invention relates to a method for producing polyether carbonate polyols, wherein: (i) in a first step, (a) carbon dioxide and propylene oxide or (b) carbon dioxide and a mixture of propylene oxide and at least one further alkylene oxide in a ratio by weight of >90:10 are attached to one or more H-functional starting substances in the presence of at least one DMC catalyst; (ii) in a second step, the reaction mixture obtained from step (i) is (ii-1) first chain-lengthened with a mixture containing propylene oxide (PO) and ethylene oxide (EO) in a PO/EO ratio by weight of 90/10 to 20/80 in the presence of at least one DMC catalyst.