Granted Patent
Utility
US 4,892,969 · App. 07/203,553
Process for the preparation of 1-amino-2-naphthol-4-sulfonic acid
Inventor:
Bruno Fortsch
Patented Case
View Patent ↗
Granted: Jan 9, 1990
Filed: May 31, 1988
Inventor
Bruno Fortsch
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.