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:
Jan. 11, 2000
Filed:
Apr. 30, 1998
Hiroshi Machida, Kurashiki, JP;
Fumiya Zaima, Kurashiki, JP;
Kengi Nakaya, Kurashiki, JP;
Kazuo Tanaka, Kurashiki, JP;
Abstract
A process for the production of high-purity dimethyl 2,6-naphthalenedicarboxylate, which comprises esterifying 2,6-naphthalenedicarboxylic acid obtained by liquid phase oxidation of 2,6-dialkylnaphthalene with molecular oxygen in the presence of an oxidation catalyst, with methanol and then purifying a crude ester formed by the esterification, the crude ester being purified in the presence of an aromatic hydrocarbon as a solvent, in which impurities contained in a reaction product obtained by the esterification of 2,6-naphthalenedicarboxylic acid prepared by the liquid phase oxidation of 2,6-dialkylnaphthalene are effectively removed with simple procedures, oxidation catalyst metals are recovered, a crystal of naphthalenedicarboxylic acid formed by the oxidation of dialkylnaphthalene and/or its oxide derivative can be easily separated, and the oxidation catalyst to be brought into the step of producing dimethyl naphthalenedicarboxylate is recovered in the process of the production of naphthalenedicarboxylic acid and effectively used in the process of the production of naphthalenedicarboxylic acid.