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. 26, 1996
Filed:
Aug. 08, 1994
Applicant:
Inventor:
James B Ganci, Wilmington, DE (US);
Assignee:
Ciba-Geigy Corporation, Tarrytown, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
546 49 ; 546 56 ;
Abstract
An aqueous phase air oxidation process for the for the preparation of unsubstituted and substituted quinacfidone pigments is disclosed. The process involves an oxidation step wherein a 6,13-dihydroquinacridone is convened to the corresponding quinacfidone, utilizing a quinone compound and molecular oxygen as oxidizing agent, in a basic, aqueous reaction medium, in the presence of a nonionic, polar organic material which forms a second liquid phase in the basic reaction medium and which is present in a minor amount relative to the amount of aqueous base in the reaction medium. The quinacridones prepared by this process are useful as pigments.