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. 03, 1992
Filed:
Oct. 12, 1990
Applicant:
Inventors:
Detlef-Ingo Schutze, Cologne, DE;
Reinold Schmitz, Odenthal, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
546 56 ; 546 49 ;
Abstract
Process for the preparation of a substituted or unsubstituted quinacridone by oxidation of a substituted or unsubstituted dihydroquinacridone with oxygen or an oxygen-containing gas in the presence of alkali, a solvent or diluent and an oxygen transfer agent, which is characterized in that the oxidation is carried out in the presence of a quaternary ammonium compound.