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:
May. 13, 2008
Filed:
Feb. 26, 2005
Laszlo Somogyi, Limburgerhof, DE;
Laszlo Somogyi, Limburgerhof, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
A process for working up β-sulfatoethylsulfonylaniline-2-sulfonic acid from a solution in aqueous sulfuric acid, comprises a first step of the β-sulfatoethylsulfonylaniline-2-sulfonic acid being precipitated by addition of alkali or alkaline earth metal and/or ammonium salts, separated off and dissolved or the sulfuric acid being precipitated by addition of calcium salts and the resulting calcium sulfate being separated off if appropriate, and a second step of the resultant solution being adjusted to a pH between 1 and 5 by addition of alkali or alkaline earth metal or ammonium hydroxide, carbonate, bicarbonate and/or acetate, any calcium sulfate still present being separated off and the β-sulfatoethylsulfonylaniline-2-sulfonic acid being isolated from the solution.