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. 27, 1982
Filed:
Feb. 19, 1980
Applicant:
Inventors:
Paolo Senni, Colleferro, IT;
Domenico Astarita, Segni-Colleferro, IT;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
203 37 ; 203 71 ; 203 91 ; 2602 / ;
Abstract
A process for purifying caprolactame by continuous and/or discontinuous (or atch) vacuum distillation comprises a first stage fast vacuum distillation of the raw caprolactame possibly in the presence of an alkaline and/or alkaline-earth hydroxide, a second stage consisting of a vacuum rectification distillation of the caprolactame obtained in the first stage and a third stage consisting of the fast vacuum distillation of the caprolactame yielded from the second stage, in the presence of an alkaline and/or alkaline-earth hydroxide. The hydroxide amount in the third and possibly the first stage distillation as well varies from 0.05 to 5% preferably from 0.1% to 1%.