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:
Dec. 29, 1992
Filed:
Apr. 01, 1991
Shuichi Mitamura, Kawasaki, JP;
Yasuhisa Tsutsumi, Kawasaki, JP;
Yoshimi Kata, Kawasaki, JP;
Atsushi Kawada, Kawasaki, JP;
Naoya Okabayashi, Kawasaki, JP;
Nippon Steel Chemical Co., Ltd., Tokyo, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
The process of this invention for preparing 2,6-naphthalene-dicarboxylic acid comprises a reaction step (Step A) wherein 2,6-naphthalene-dicarboxylic acid potassium salts consisting of 2,6-naphthalene-dicarboxylic acid dipotassium salt and/or 2,6-naphthalene-dicarboxylic acid monopotassium salt are allowed to react with benzene-carboxylic acids in the presence of water to yield 2,6-naphthalene-dicarboxylic acid and benzene-carboxylic acid potassium salts and a separation step (Step B) wherein the crystallized 2,6-naphthalene-dicarboxylic acid is separated from the benzene-carboxylic acid potassium salts dissolved in the aqueous solution and provides 2,6-naphthalene-dicarboxylic acid, useful as raw material for polymers, at low cost on a commerical scale with recycle of potassium.