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. 22, 2016
Filed:
Apr. 22, 2013
Zhengfeng Zhang, Shanghai, CN;
Gerhard Koelbl, Gernsheim, DE;
Lorenza Sartorelli, Ober-Ramstadt, DE;
Horst Hiltner, Muenster, DE;
Huisheng Wang, Shanghai, CN;
Mirko Michel, Dortmund, DE;
Zhengfeng Zhang, Shanghai, CN;
Gerhard Koelbl, Gernsheim, DE;
Lorenza Sartorelli, Ober-Ramstadt, DE;
Horst Hiltner, Muenster, DE;
Huisheng Wang, Shanghai, CN;
Mirko Michel, Dortmund, DE;
EVONIK RÖHM GmbH, Darmstadt, DE;
Abstract
This invention relates to a process of preparing highly pure, non-yellowing (meth)acrylic acid necessary for high-tech applications requiring long-tem color stability in the presence of amines. Process for the preparation of highly pure, non-yellowing (meth)acrylic acid comprising the steps: f) Condensation of a (meth)acrylic acid-containing gas phase obtained via a gas phase oxidation process of a C4-compound to generate an aqueous (meth)acrylic acid solution g) Separation of the (meth)acrylic acid from the aqueous (meth)acrylic acid solution to obtain crude (meth)acrylic acid h) Rectification of the crude (meth)acrylic acid to obtain pure (meth)acrylic acid via a sidestream outlet of the rectification column i) Treatment of the pure (meth)acrylic acid generated in step c) with an ion exchange resin j) Distillation of the (meth)acrylic acid generated in step d).