Granted Patent
Utility
US 4,285,859 · App. 06/014,778
Azo compounds useful in a photographic dye diffusion transfer process
Inventors:
Rainer Kitzing, Brian R. D. Whitear, William E. Long, David L. R. Reeves, Glenn Wood
Patented Case
View Patent ↗
Granted: Aug 25, 1981
Filed: Feb 23, 1979
Inventors
Rainer Kitzing
Brian R. D. Whitear
William E. Long
David L. R. Reeves
Glenn Wood
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.