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:
May. 22, 1979
Filed:
Nov. 10, 1977
Rupert Wenzel, Leverkusen, DE;
Johann Grolig, Leverkusen, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
A process has been provided for the purification of crude anthraquinone made by (1) oxidation of naphthalene to naphthoquinone (2) reaction of the oxidation product with butadiene to give tetrahydroanthraquinone and (3) oxide-hydrogenation of this reaction product with molecular oxygen to yield the crude anthraquinone, then optionally separating naphthalene, phthalic anhydride and low-boiling compounds from said crude anthraquinone. The purification of said crude anthraquinone is effected by treatment with an oxygen compound or mixture of oxygen compounds of the elements of the 1st and/or 2nd main group of the periodic system at elevated temperature, if desired in the presence of an inert solvent and the purified anthraquinone is isolated by physical separation methods from the products treated.