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. 08, 1980
Filed:
Oct. 17, 1978
Tsuneo Kimura, Kitakyushu, JP;
Hiroshi Hashizume, Kitakyushu, JP;
Yoshiaki Izumisawa, Kitakyushu, JP;
Mitsubishi Chemical Industries, Limited, Tokyo, JP;
Abstract
A process for the continuous preparation of pure terephthalic acid by oxidation of p-xylene with molecular oxygen in acetic acid solvent comprising conducting the oxidation at a temperature of 205.degree. to 230.degree. C. in the presence of an oxidation catalyst comprising (a) a cobalt compound in an amount of at least 120 ppm and less than 200 ppm as cobalt based on the weight of solvent, (b) a manganese compound sufficient to provide a manganese to cobalt weight ratio of 0.5 to 1.5 and (c) a bromine compound selected from hydrogen bromide, cobalt bromide and manganese bromide in an amount of 200 to 1,000 ppm as bromine based on the weight of solvent, while the water content of the liquid phase of the reaction system is kept at 4 to 14 percent by weight.