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. 30, 2018
Filed:
Dec. 22, 2015
Covestro Llc, Pittsburgh, PA (US);
Jack R. Reese, Coraopolis, PA (US);
Phillip E. Bowles, North Fort Myers, FL (US);
Edward P. Browne, Cologne, DE;
Covestro LLC, Pittsburgh, PA (US);
Abstract
This invention relates to a semi-batch process for producing low molecular weight polyoxyalkylene polyols. These polyoxyalkylene polyols are characterized by hydroxyl numbers of from 200 to 500. In accordance with the invention, the first alkylene oxide block used to activate the DMC catalyst comprises from 50% to 100% by weight of propylene oxide and from 0% to 50% by weight of ethylene oxide; and the second alkylene oxide block comprises from 50% to 100% by weight of propylene oxide and from 0% to 50% by weight of ethylene oxide. A continuously added starter is present. Optionally, a third alkylene oxide block can be added. The addition of the second alkylene oxide block and of the third alkylene oxide block when present is completed with a space time yield of greater than or equal to 250 kg/m/hr.