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:
Feb. 09, 1999
Filed:
Oct. 14, 1997
Stefan Jelko, Haltern, DE;
Anton Schoengen, Witten, DE;
Hermann-Josef Korte, Haltern, DE;
Gerhard Franz, Marl, DE;
Hans-Guenther Srebny, Nienburg, DE;
Thomas Jostmann, Duelmen, DE;
Frank Steding, Marl, DE;
Huels Aktiengesellschaft, Marl, DE;
Abstract
A process is provided for the oxidation of p-xylene and methyl p-tolulate with oxygen-containing gases in the Witten-Hercules process for preparing dimetyl terephthalate in at least two sequentially arranged stages and in the presence of a catalyst, wherein the process involves oxidizing p-xylene and methyl p-toluate with oxygen containing gases in at least two sequential stages in the presence of a catalyst, wherein the at least two sequential stages include at least one p-xylene rich stage and at least one methyl p-toluate rich stage, wherein at least one of the following steps (a) and (b) occurs: