Granted Patent
Utility
US 4,357,280 · App. 06/268,222
Use of tertiary phosphines in photographic silver dye bleach materials
Inventors:
Christoph Chylewski, Gerald Jan, Roland Kurzen, Max Meier, Matthias Schellenberg
Patented Case
View Patent ↗
Granted: Nov 2, 1982
Filed: May 29, 1981
Inventors
Christoph Chylewski
Gerald Jan
Roland Kurzen
Max Meier
Matthias Schellenberg
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.