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:
Dec. 04, 2001
Filed:
May. 11, 2000
Applicant:
Inventors:
Jörg Erbes, Ludwigshafen, DE;
Alfons Ludwig, Höxter, DE;
Gunter Pipper, Bad Dürkheim, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G 6/908 ; C08G 7/310 ; C08F 6/00 ;
U.S. Cl.
CPC ...
C08G 6/908 ; C08G 7/310 ; C08F 6/00 ;
Abstract
A process for continuous extraction of polyamide particles using a recirculating extractant in a vertical extraction column that is divided into two zones comprises treating the polyamide with an aqueous extractant comprising from 40 to 95% by weight of &egr;-caprolactam in a first zone at from 100 to 140° C., and then effecting an aftertreatment with water in a second zone. The caprolactam can then be extracted in a conventional manner. The process provides for economical production of polyamide having a low dimer content.