Granted Patent
Utility
US 4,973,409 · App. 07/408,859
Treatment of aqueous systems
Inventor:
Barry Cook
Patented Case
View Patent ↗
Granted: Nov 27, 1990
Filed: Sep 18, 1989
Inventor
Barry Cook
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.