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:
Dec. 07, 1976
Filed:
Apr. 01, 1976
Applicant:
Inventors:
Bernd Schroeder, Odenthal, DT;
Wolfgang Auge, Cologne, DT;
Karl-Werner Thiem, Cologne, DT;
Rutger Neeff, Leverkusen, DT;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DT;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C09B / ;
U.S. Cl.
CPC ...
260369 ;
Abstract
A mixture of dinitroanthraquinones of which at least 35% is 1,5-dinitroanthraquinone is dissolved at elevated temperature in a halogenated aromatic hydrocarbon, a carboxylic acid nitrile or a cyclic sulphone and is thereafter cooled selectively to precipitate substantially pure 1,5-dinitroanthraquinone. Preferred solvents are 1-chloronaphthalene, sulpholane and adipic acid dinitrile. The temperature of dissolution ranges from about 120.degree. C up to the boiling point and cooling is by about 10.degree. to 200.degree. C to a temperature not below about 0.degree. C.