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:
Sep. 28, 1999
Filed:
Sep. 28, 1998
Fumio Okoshi, Okayama-ken, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Toyo Boseki Kabushiki Kaisha, Osaka, JP;
Mizushima Aroma Company, Ltd., Kurashiki, JP;
Abstract
There is disclosed a process for producing an aromatic carboxylic acid (e.g.iso-or-tere-phthalic acid) by liquid-phase oxidation of an alkyl-group-substituted aromatic compound (e.g. p-or-m-xylene) in acetic acid which comprises dehydrating water-containing acetic acid by azeotropic distillation in an azeotropic distillation dehydration tower to recycle the dehydrated acetic acid as the solvent, and suppressing the concentration of the alkyl-group-substituted aromatic compound in the entrainer (e.g. n-butyl acetate) which is fed at the top portion of the above tower, to at most 10% by weight by removing the above aromatic compound. The process makes it possible to proceed with efficient dehydration of water-containing acetic acid for a long period of time by preventing the separation efficiency between acetic acid and an azeotropic component from being deteriorated by the alkyl-group-substituted aromatic compound remaining in the azeotropic component.