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. 04, 1982
Filed:
Nov. 03, 1980
Applicant:
Inventors:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
2602 / ;
Abstract
A process for the purification of raw caprolactam obtained by extraction h alkylated phenols from its sulphuric solution, re-extraction with water, oxidation preferably with KMnO.sub.4, evaporation of water and distillation, comprises, before the oxidation treatment, a 'fast distillation', in the presence of an alkali. The oxidation is conducted at 0.degree.-80.degree. C. and at atmospheric pressure with 0.005-0.5% by weight of KMnO.sub.4. The amount of alkali (NaOH) used in the fast distillation is comprised between 0.05 and 0.5% by weight.