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. 16, 1995
Filed:
Oct. 04, 1994
Takeshi Namekata, Kashima, JP;
Ikuo Ito, Kashima, JP;
Kazuhiko Maeda, Kashima, JP;
Toshio Sato, Kashima, JP;
Keiichi Yokota, Kashima, JP;
Sumikin Chemical Co., Ltd., Tokyo, JP;
Abstract
An improved process for manufacturing 5-hydroxyisophthalic acid by means of oxidizing 5-acyloxy-m-xylene or its oxidation intermediate with molecular oxygen in a solvent consisting of lower aliphatic carboxylic acid and acetic anhydride in the presence of catalyst consisting of heavy metal comprising cobalt as the main component, and a bromine compound, and hydrolyzing the product thereby obtained. The improvement is characterized in that the oxidation is carried out under a pressure of 2-15/cm.sup.2 gauge in the presence of an alkali metal compound corresponding to 0.1-1.1 gram atom in terms of alkali metal atom based upon 1 gram atom of the heavy metal used for the catalyst. The present invention produces a high-quality 5-hydroxyisophthalic acid having excellent color from 5-acyloxy-m-xylene.