Granted Patent
Utility
US 4,314,937 · App. 06/128,228
1:2 Chromium unsymmetrical complexes of azo and disazo dyes
Inventor:
Fabio Beffa
Patented Case
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Granted: Feb 9, 1982
Filed: Mar 7, 1980
Inventor
Fabio Beffa
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.