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:
Jun. 04, 2002
Filed:
Jan. 11, 2000
Applicant:
Inventors:
Albert-Johannes Frings, Rheinfelden, DE;
Michael Horn, Rheinfelden, DE;
Peter Jenker, Rheinfelden, DE;
Jaroslaw Monkiewicz, Rheinfelden, DE;
Hans-Guenther Srebny, Duelmen, DE;
Burkhard Standke, Loerrach, DE;
Bertram Trautvetter, Rheinfelden, DE;
Assignee:
Degussa-Huels Aktiengesellschaft, Frankfurt, DE;
Primary Examiner:
Int. Cl.
CPC ...
B01D 3/00 ; B01D 1/100 ; B01D 1/500 ; C07C / ;
U.S. Cl.
CPC ...
B01D 3/00 ; B01D 1/100 ; B01D 1/500 ; C07C / ;
Abstract
An apparatus for the purification of crude N,N′-diphenyl-p-phenylenediamine (DPPD) in which there is an extraction unit containing a liquid permeable container and an adsorption layer downstream of the container, a solvent evaporator downstream of the adsorption layer, a filter unit, a line for returning the filtrate to the solvent evaporator, and a condenser for returning solvent to the extraction unit.