Granted Patent
Utility
US 5,116,955 · App. 07/587,385
Process for the preparation of mono- and polyazo dyes
Inventors:
Horst Langfeld, Roland Minges
Patented Case
View Patent ↗
Granted: May 26, 1992
Filed: Sep 25, 1990
Inventors
Horst Langfeld
Roland Minges
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.