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. 11, 1993
Filed:
Dec. 30, 1991
Gerhard Frank, Hirschberg, DE;
Guenter Herrmann, Heidelberg, DE;
Gert Buerger, Mannheim, DE;
Jost H Manegold, Lambsheim, DE;
Stefan Karbach, Neustadt, DE;
Ruediger Schmitz, Lambsheim, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
A process for working up mother liquors resulting from the preparation of adipic acid by oxidation of cyclohexanol or cyclohexanone or mixtures thereof with nitric acid entails removal of nitric acid by azeotropic distillation with water, heating the resulting melt at from 130.degree. to 180.degree. C. and then dissolving it in water, treating the aqueous solution with cation exchangers, subsequently again evaporating off the water and heating the resulting dicarboxylic acid melt at from 200.degree. to 240.degree. C. and then obtaining a mixture of dicarboxylic acids by distillation.