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:
Jun. 13, 1995
Filed:
Sep. 15, 1993
Applicant:
Inventors:
Shivakumar B Hendi, Newark, DE (US);
Donald L Bauman, Wilmington, DE (US);
Edward E Jaffe, Wilmington, DE (US);
Assignee:
Ciba-Geigy Corporation, Ardsley, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
546 49 ; 546 56 ;
Abstract
A process for the direct preparation of pigmentary 2,9-dichloroquinacridone, which comprises oxidizing 2,9-dichloro-6,13-dihydroquinacridone directly to pigmentary 2,9-dichloroquinacridone by heating a reaction mixture comprising 2,9-dichloro-6,13-dihydroquinacridone, an alkali metal hydroxide, a water-soluble organic solvent, water and effective amounts of an oxidizing agent and a phthalimidomethylquinacridone particle growth inhibitor. The process yields pigmentary 2,9-dichloroquinacridone directly; without the need for additional particle-size reducing aftertreatments.