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:
Mar. 13, 1984
Filed:
Jul. 01, 1982
Applicant:
Inventors:
Assignee:
Nippon Shokubai Kagaku Kogyo Co., Ltd., Koraibashi, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549251 ;
Abstract
A method for the manufacture of high-purity phthalic anhydride, which comprises exposing crude phthalic anhydride obtained by vapor-phase catalytic oxidation of ortho-xylene to contact with a gas containing molecular oxygen at an elevated temperature in the presence of an alkali metal salt of at least one carboxylic acid selected from the group consisting of maleic acid, succinic acid and benzoic acid, and optionally a manganese-containing alloy, and subsequently subjecting the resultant reaction mixture to distillation.