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:
Jun. 23, 1998
Filed:
May. 19, 1997
Martin A Zeitlin, Naperville, IL (US);
David L Sikkenga, Wheaton, IL (US);
Stephen V Hoover, Aurora, IL (US);
Paul K Behrens, Warrenville, IL (US);
Amoco Corporation, Chicago, IL (US);
Abstract
Economical processes are disclosed for preparing relatively pure polycarboxylic acid from typical crude products of liquid phase oxidation, which do not involve intermediate steps of ester formation or require any alkanol containing solvent, for purification of 'crude' polycarboxylic acid containing impurities which include one or more monofunctional aromatic compounds, trifunctional aromatic compounds, and/or color causing organic compounds formed by oxidation of a corresponding substituted aromatic compound in a liquid phase, e.g. 2,6-naphthalene dicarboxylic acid by liquid phase oxidation of 2,6-dimethyl naphthalene. The invention provides integrate processes which comprise reacting crude oxidation product with a polyalkyl amine amine, e.g. trialkylamine, forming an aqueous solution of the salts thus obtained, separating deleterious compounds from the solution, and recovering the polyalkyl amine and a relatively pure polycarboxylic acid product.