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:
Oct. 06, 1992
Filed:
Jun. 25, 1982
Applicant:
Inventors:
Ryo Matsuura, Yamato, JP;
Tatsuyoshi Komatsu, Kamakura, JP;
Kenji Usui, Tokyo, JP;
Toru Sato, Kawasaki, JP;
Assignee:
Kawasaki Kasei Chemicals Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ;
U.S. Cl.
CPC ...
552296 ; 562485 ; 562486 ;
Abstract
Naphthoquinone having a purity of higher than 95% is separated from an aqueous slurry of naphthoquinone and phthalic acid prepared by contacting, with an aqueous medium, a reaction mixture gas containing naphthoquinone and phthalic anhydride formed by a catalytic vapor phase oxidation of naphthalene. An extraction of naphthoquinone is carried out with a chain or cyclic saturated hydrocarbon at 60.degree. to 110.degree. C. under the condition adjusting pH to 1.2 to 5 and substantially dissolving phthalic acid in the aqueous phase and leaving resinous materials as a bottom.