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. 12, 1977
Filed:
Aug. 11, 1975
Rudolph Hans Gath, Mannheim, DT;
Hugo Fuchs, Ludwigshafen, DT;
BASF Aktiengesellschaft, Ludwigshafen (Rhine), DT;
Abstract
A method of simultaneously purifying crude caprolactams obtained from the Beckmann rearrangement of cyclohexanone oxime in oleum and the gas-phase rearrangement of cyclohexanone oxime in the presence of catalysts. The improvement consists in that the crude caprolactam obtained from the catalytic gas-phase rearrangement is added to the acid rearrangement mixture derived from the Beckmann rearrangement in oleum and the mixture is maintained at temperatures of from 100.degree. to 200.degree. C with thorough mixing, whereupon it is neutralized and worked up. Advantageously, the content of lactam in the catalytic gas-phase rearrangement is from 5 to 30% of the content of lactam in the acid rearrangement mixture obtained from the Beckmann rearrangement.