Granted Patent
Utility
US 4,431,583 · App. 06/183,892
Phenyl- or naphthyl-azo-(8-hydroxyquinoline) 1:2-cobalt complex dyes for leather
Inventor:
Gerhard Back
Patented Case
View Patent ↗
Granted: Feb 14, 1984
Filed: Sep 4, 1980
Inventor
Gerhard Back
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.