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:
Apr. 24, 2001
Filed:
Mar. 17, 1999
Applicant:
Inventors:
Eric B. Henriet, Lyons, FR;
Philippe Leconte, Meyzieu, FR;
Carl Patois, Lyons, FR;
Robert Perron, Charly, FR;
Assignee:
Rhodia Fiber and Resin Intermediates, Courbevoie Cedex, FR;
Primary Examiner:
Int. Cl.
CPC ...
C07C 5/500 ; C07C 5/100 ;
U.S. Cl.
CPC ...
C07C 5/500 ; C07C 5/100 ;
Abstract
The invention discloses a method for purifying adipic acid in water. More precisely it discloses an improvement in adipic acid crystallization or recrystallization in water, characterised in that the said crystallization or recrystallization is effected in presence of a strong proton acid and/or in the presence of carbon monoxide. This crystallization or recrystallization particularly enables the content of metal catalyst traces in the adipic acid to be reduced.