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. 27, 1999
Filed:
Jun. 16, 1998
Applicant:
Inventors:
Wiston Lamshing, Katy, TX (US);
Fu-Ming Lee, Katy, TX (US);
Randi Wright Wytcherley, Belgrade, MT (US);
Assignee:
HFM International, Inc., Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
562487 ;
Abstract
A method for reducing carboxybenzaldehyde isomers in crude terephthalic and/or isophthalic acids is described. Crude TPA or IPA is dissolved in N-methyl pyrrolidone and is subsequently contacted with an oxidant, such as substantially anhydrous hydrogen peroxide, to convert the carboxybenzaldehyde isomer (4-CBA or 3-CBA) to TPA or IPA under moderate temperature and pressure conditions.