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:
Apr. 11, 2017
Filed:
Dec. 05, 2014
Steffen Krill, Muehltal, DE;
Alexander Lygin, Griesheim, DE;
Torsten Balduf, Pfungstadt, DE;
Rudolf Burghardt, Darmstadt, DE;
Andreas Tepperis, Bad Koenig, DE;
Matthias Groemping, Darmstadt, DE;
Steffen Krill, Muehltal, DE;
Alexander Lygin, Griesheim, DE;
Torsten Balduf, Pfungstadt, DE;
Rudolf Burghardt, Darmstadt, DE;
Andreas Tepperis, Bad Koenig, DE;
Matthias Groemping, Darmstadt, DE;
EVONIK ROEHM GmbH, Darmstadt, DE;
Abstract
The present invention relates to a process for preparing methyl methacrylate by a direct oxidative esterification of methacrolein with oxygen and methanol, which is conducted in the liquid phase at a pressure of 2 to 100 bar with a gold catalyst. According to the invention, the liquid phase is withdrawn continuously from the reactor and optionally enriched with oxygenous gas, the pH, after the withdrawal, is adjusted to a pH between 5 and 9 by means of addition of a basic solution and this liquid phase is conducted back into the reactor again to an extent of at least 50%.