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. 15, 1985
Filed:
Feb. 24, 1984
Applicant:
Inventors:
Fritz Gude, Herne, DE;
Herbert Haferkorn, Bottrop, DE;
Assignee:
Chemische Werke Huls Aktiengesellschaft, Marl, DE;
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549250 ; 549251 ;
Abstract
The invention relates to a process for removing naphthoquinone from phthalic anhydride produced by the air oxidation of naphthalene or mixtures containing naphthalene. Specifically, crude phthalic anhydride containing naphthoquinone is treated at a temperature of 180.degree.-280.degree. C. with an unsaturated aliphatic oil produced by the polymerization of 1,3-dienes and optionally isomerized having a molecular weight of 800-5,000, and optionally in the presence of 1-40 ppm of alkali ions, relative to the crude phthalic anhydride.