Granted Patent
Utility
US 5,284,939 · App. 07/882,981
Process for the preparation of highly concentrated solutions of cationic azo dyes
Inventors:
Alex Nicopoulos, Hanspeter Birri, Gerhard Hanika
Patented Case
View Patent ↗
Granted: Feb 8, 1994
Filed: May 14, 1992
Inventors
Alex Nicopoulos
Hanspeter Birri
Gerhard Hanika
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.