Granted Patent
Utility
US 4,855,048 · App. 07/150,265
Air dried cellulose acetate membranes
Inventors:
Man-Wing Tang, William M. King, C. Glen Wensley
Patented Case
View Patent ↗
Granted: Aug 8, 1989
Filed: Jan 29, 1988
Inventors
Man-Wing Tang
William M. King
C. Glen Wensley
Assignee (at issue)
Air Products and Chemicals, Inc.
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.