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. 17, 2002
Filed:
May. 24, 2000
Applicant:
Inventors:
Ryusuke Shigematsu, Ibaraki-ken, JP;
Masayoshi Hayashi, Ibaraki-ken, JP;
Akio Hashimoto, Ibaraki-ken, JP;
Makoto Takagawa, Ibaraki-ken, JP;
Assignee:
Mitsubishi Gas Chemical Company, Inc., Chiyoda-ku, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C 5/142 ;
U.S. Cl.
CPC ...
C07C 5/142 ;
Abstract
Highly pure, less colored aromatic polycarboxylic acids are produced from crude aromatic polycarboxylic acids by simple procedures at low production costs. The crude aromatic polycarboxylic acid is mixed with aliphatic amine or alicyclic amine in the presence of a solvent to precipitate crystals of amine salt of aromatic polycarboxylic acid. The crystals are dissolved in water and decomposed, thereby obtaining the highly pure aromatic polycarboxylic acids.