Granted Patent
Utility
US 4,701,186 · App. 06/509,637
Polymeric membranes with ammonium salts
Inventor:
Anthony Zampini
Patented Case
View Patent ↗
Granted: Oct 20, 1987
Filed: Jun 30, 1983
Inventor
Anthony Zampini
Assignee (at issue)
Monsanto Company
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.