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:
Oct. 28, 1980
Filed:
May. 19, 1978
Maomi Seko, Tokyo, JP;
Tetsuya Miyake, Tokyo, JP;
Hiroshi Takeuchi, Nobeoka, JP;
Masatoshi Tanouchi, Nobeoka, JP;
Asahi Kasei Kogyo Kabushiki Kaisha, Osaka, JP;
Abstract
An improved process for the production of a high purity terephthalic acid by a liquid phase oxidation reaction of para-xylene by means of molecular oxygen or a molecular oxygen-containing gas in an aliphatic monocarboxylic acid solvent in the presence of a cobalt-manganese-bromine catalyst system, characterized in that as the cobalt-manganese-bromine catalyst system there is used a catalyst system of a specific composition at a specific concentration, and the liquid phase oxidation reaction is effected in the presence of acetaldehyde in addition to the cobalt-manganese-bromine catalyst system under relatively mild temperature (170.degree.-190.degree. C.) and pressure conditions while maintaining the water concentration in the reaction system at a specified low level. The terephthalic acid produced according to the process of the present invention is of so high a quality that it can be used for the direct production of a polyalkylene terephthalate from the acid and an alkylene glycol or ethylene oxide, which direct production does not need the preparation of an intermediate such as a methyl ester of terephthalic acid.