Granted Patent
Utility
US 4,929,752 · App. 07/352,652
Process for the preparation of 1-amine-2-naphthol-4-sulfonic acid
Inventors:
Bernhard Albrecht, Jurgen Beyrich
Patented Case
View Patent ↗
Granted: May 29, 1990
Filed: May 12, 1989
Inventors
Bernhard Albrecht
Jurgen Beyrich
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.