Granted Patent
Utility
US 5,504,227 · App. 08/400,920
Anthraquinone dyes, process for their preparation and the use thereof
Inventors:
Urs Lehmann, Marcel Frick
Patented Case
View Patent ↗
Granted: Apr 2, 1996
Filed: Mar 8, 1995
Inventors
Urs Lehmann
Marcel Frick
Assignee (at issue)
Ciba-Geigy
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.