Granted Patent
Utility
US 5,190,847 · App. 07/661,596
Photographic silver halide materials containing aryl hydrazides
Inventors:
Dominic M. Chan, Reinhold Ruger
Patented Case
View Patent ↗
Granted: Mar 2, 1993
Filed: Feb 20, 1991
Inventors
Dominic M. Chan
Reinhold Ruger
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND COMPANY
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.