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:
Oct. 17, 2023
Filed:
Jun. 04, 2019
Shpp Global Technologies B.v., Bergen op Zoom, NL;
Robert John Werling, Mt. Vernon, IN (US);
Simon Padmanabhan, Mt. Vernon, IN (US);
Aaron Matthew Royer, Mt. Vernon, IN (US);
Bradley Osborne, Mt. Vernon, IN (US);
Christopher Poirier, Mt. Vernon, IN (US);
SHPP GLOBAL TECHNOLOGIES B.V., Bergen op Zoom, NL;
Abstract
A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent and converting to the corresponding aromatic dianhydride. The extracting is carried out in an extraction column including a high specific surface area metal packing material and having an interface between the aqueous reaction mixture and the organic solvent that is at a level that is 14 to 85% of the height of the extraction column.