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:
Jul. 20, 1993
Filed:
Jun. 07, 1991
Applicant:
Inventors:
Johannes Pfenninger, Rechthalten, CH;
Walter C Zukowski, Wilmington, DE (US);
Fridolin Babler, Hockessin, DE (US);
Edward E Jaffe, Wilmington, DE (US);
Assignee:
Ciba-Geigy Corporation, Ardsley, NY (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
546 49 ;
Abstract
A process for preparing a modified beta quinacridone polytype having identified color space values which comprises the steps of dry pre-milling beta phase quinacridone, deaggregating the pre-milled product in an alcohol-base medium and ripening the deaggregated product in the presence of an oxidizing agent.