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:
Mar. 14, 2000
Filed:
Oct. 14, 1998
Applicant:
Inventors:
Assignee:
Elf Atochem S.A., , FR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
204529 ; 204530 ; 204541 ;
Abstract
In order to remove the salts (in particular NH.sub.4 Cl) present in an aqueous sulphonamide solution (in particular CH.sub.3 SO.sub.2 NH.sub.2), the solution is subjected to a two-compartment electrodialysis. By maintaining the pH at a value below 7, the formation of ammonia is avoided. The demineralized solution can be concentrated in order to receover after crystallization, the sulphonamide.