Granted Patent
Utility
US 4,364,864 · App. 06/018,089
1:2 Cobalt and chromium complex unsymmetrical azo dyes
Inventors:
Fabio Beffa, Gerhard Back, Hans U. Schutz
Patented Case
View Patent ↗
Granted: Dec 21, 1982
Filed: Mar 6, 1979
Inventors
Fabio Beffa
Gerhard Back
Hans U. Schutz
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.