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, 1979
Filed:
Jun. 23, 1977
Applicant:
Inventors:
Christian Pieper, Neuss, DE;
Surinder S Sandhu, Dormagen, DE;
Gunter Schummer, Cologne, DE;
Karlheinz Feltgen, Dormagen, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ; C07C / ; C07C / ;
U.S. Cl.
CPC ...
203 14 ; 203 26 ; 203 73 ; 203 71 ; 203D / ; 2605 / ;
Abstract
The recovery of dimethylacylamides from solutions which are formed during the production of fibres is particularly economical if the solution is concentrated in a separating column to produce a sump product having a DMA content of 30 to 90% at pressures of more than 300 Torr, using the evaporation heat of the head product for heating the column, with the aid of a compressor and then separating the sump product which is concentrated in DMA by distillation.