Granted Patent
Utility
US 4,582,896 · App. 06/503,949
1:2-metal complex dyes containing one atom of chromium or cobalt and two azo dyes each formed by coupling two diazo compounds to resorcinol
Inventor:
Gerhard Back
Patented Case
View Patent ↗
Granted: Apr 15, 1986
Filed: Jun 13, 1983
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.