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:
Jan. 05, 1999
Filed:
May. 09, 1997
Applicant:
Inventor:
Fridolin Babler, Hockessin, DE (US);
Assignee:
Ciba Specialty Chemicals Corporation, Tarrytown, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
546 49 ;
Abstract
The present invention relates to a process of preparing quinacridone pigments in their specific crystal forms by oxidizing a premilled 6,13-dihydroquinacridone corresponding to the quinacridone pigment in a basic, aqueous reaction medium utilizing hydrogen peroxide as the oxidizing agent. The inventive process is an environmentally friendly process which yields a polymorphically homogeneous product in excellent yield.