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. 27, 1977
Filed:
Apr. 30, 1975
Richard Wessendorf, Essen-Heisingen, DT;
August Sommer, Herne, DT;
Heinrich Birkelbach, Oer-Erkenschwick, DT;
Veba-Chemie AG, Gelsenkirchen-Buer, DT;
Abstract
An improvement in a process for refining crude glyoxal solutions, especially those obtained by the oxidation of acid aldehyde with nitric acid, wherein the crude glyoxal solution, free of volatile acids, is neutralized, the glyoxal is transformed to the glyoxal semiacetal with an alcohol having 1 to 3 carbon atoms and, after separation of the salts and other impurities, is again hydrolized with water at elevated temperatures. The improvement described involves continuously extracting the glyoxal semiacetal formed with an organic solvent which is immiscible with water, hydrolyzing the extracted glyoxal semiacetal and refining the aqueous glyoxal solution obtained with active charcoal.