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. 15, 2005
Filed:
Dec. 23, 2003
Applicants:
Ulrich Schädeli, Plasselb, CH;
Edward Ephraim Jaffe, Wilmington, DE (US);
Linda Snyderallen, Wilmington, DE (US);
Inventors:
Ulrich Schädeli, Plasselb, CH;
Edward Ephraim Jaffe, Wilmington, DE (US);
Linda SnyderAllen, Wilmington, DE (US);
Assignee:
Ciba Specialty Chemicals Corporation, Tarrytown, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D471/02 ; C07D471/00 ;
U.S. Cl.
CPC ...
Abstract
A process for the preparation of a quinacridone comprises oxidation of a 6,13-dihydroquinacridone using hydrogen peroxide, wherein a polymeric dispersant is present in the oxidation reaction mixture. The resulting pigment products exhibit greatly improved dispersibility relative to pigments in which the polymeric dispersant is not present during the oxidation reaction.