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:
Apr. 16, 1991
Filed:
Dec. 14, 1989
Applicant:
Inventors:
Ryoichi Yamamoto, Yamaguchi, JP;
Hiroshi Suzuki, Yamaguchi, JP;
Assignee:
Mitsui Petrochemical Industries, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
562485 ; 562414 ; 562416 ; 562417 ; 562486 ;
Abstract
A process for exchanging a dispersing medium of a terephthalic acid slurry by introducing an aliphatic carboxylic acid slurry of terephthalic acid into a multi-stage column at the upper part thereof and introducing water at the lower part thereof to form an upflowing stream of water in the multi-stage column, while a sedimentation of terephthalic acid particles is effected, and withdrawing an aqueous aliphatic carboxylic acid solution from the upper part of the multi-stage column and an aqueous slurry of terephthalic acid from the lower part of the multi-stage column.