Granted Patent
Utility
US 4,803,151 · App. 07/013,419
Photographic material for the silver dye bleach process comprising an AZO dye, capable of laking, in gelatine
Inventors:
Rolf Steiger, Matthias Schellenberg
Patented Case
View Patent ↗
Granted: Feb 7, 1989
Filed: Feb 11, 1987
Inventors
Rolf Steiger
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.