Granted Patent
Utility
US 4,324,898 · App. 06/071,329
Heterocyclic compounds useful as color photographic material
Inventor:
Paul Tschopp
Patented Case
View Patent ↗
Granted: Apr 13, 1982
Filed: Aug 30, 1979
Inventor
Paul Tschopp
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.