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:
May. 03, 2005
Filed:
May. 19, 2003
Kazuo Tanaka, Kurashiki, JP;
Hiroshi Ogawa, Kurashiki, JP;
Ikutraro Maruki, Kurashiki, JP;
Atsushi Okoshi, Kurashiki, JP;
Kazuo Tanaka, Kurashiki, JP;
Hiroshi Ogawa, Kurashiki, JP;
Ikutraro Maruki, Kurashiki, JP;
Atsushi Okoshi, Kurashiki, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
A process for producing pyromellitic acid which comprises oxidizing 2,4,5-trimethylbenzaldehyde and/or its oxidized derivative in the presence of a catalyst containing iron, manganese and bromine, or additionally containing zirconium or cerium continuously or semi-continuously using aqueous acetic acid solvent and 0.05-2% by weight of bromide ion. The catalyst used in the present invention has high activity, and the catalyst solution has low corrosive because the reaction is performed at low bromide concentration by using a solvent of aqueous acetic acid. So pyromellitic acid is produced industrially advantageously in high yield continuously or semi-continuously which has been a major difficulty up to now.