Granted Patent
Utility
US 4,822,382 · App. 07/115,913
Composite membranes, their manufacture and their use
Inventor:
Joyce K. Nelson
Patented Case
View Patent ↗
Granted: Apr 18, 1989
Filed: Nov 2, 1987
Inventor
Joyce K. Nelson
Assignee (at issue)
Union Carbide Corporation
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.