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:
Nov. 12, 2013
Filed:
May. 08, 2008
Sascha Braune, Luftenberg An der Donau, AT;
Bernhard Holub, Strassham, AT;
Christoph Huber, Langenstein, AT;
Sascha Braune, Luftenberg An der Donau, AT;
Bernhard Holub, Strassham, AT;
Christoph Huber, Langenstein, AT;
DSM Fine Chemicals Austria NFG GmbH & Co Kg, Linz, AT;
Abstract
Improved process for working up diacetone acrylamide solutions, obtained by reaction of acetone or diacetone alcohol with acrylonitrile and sulfuric acid and subsequent dilution and neutralization, in which a) the organic phase obtained subsequent to the neutralization, which comprises the crude diacetone acrylamide, is hydrolyzed by addition of an aqueous alkaline solution in order to remove acrylamide, then b) after phase separation has been carried out, the organic phase, which comprises the crude diacetone acrylamide, is neutralized by addition of an acid, and c) in succession, low-boiling-point byproducts are removed by distillation in the presence of one or more polymerization inhibitors, then t-butylacrylamide is removed by distillation and, finally, the diacetone acrylamide is isolated by product distillation, and d) the diacetone acrylamide thus obtained is converted into its final form.