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:
Mar. 27, 2012
Filed:
Jan. 24, 2007
Applicants:
Randolf Hugo, Dirmstein, DE;
Kirsten Dahmen, Mannheim, DE;
Sabine Huber, Limburgerhof, DE;
Inventors:
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B01D 3/10 (2006.01);
U.S. Cl.
CPC ...
Abstract
A process comprising: continuously distilling a crude xylylenediamine in a column to form a pure xylylenediamine and a bottom product, wherein the column comprises a distillation column having a side draw and the distillation column is operated under a reduced pressure and a bottom temperature of 185° C. or less; drawing off the pure xylylenediamine from the side draw; evaporatively concentrating the bottom product of the distillation column in an additional evaporation stage to form a condensate; and returning the condensate into the distillation column.