Granted Patent
Utility
US 5,269,931 · App. 07/747,668
Cationic charge modified microporous membranes
Inventors:
Ho-Pin Hu, Inessa Katsnelson, Alan Sellinger, Wesley Tamashiro
Patented Case
View Patent ↗
Granted: Dec 14, 1993
Filed: Aug 20, 1991
Inventors
Ho-Pin Hu
Inessa Katsnelson
Alan Sellinger
Wesley Tamashiro
Assignee (at issue)
Gelman Sciences
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.