Granted Patent
Utility
US 5,013,439 · App. 07/433,450
Microporous membranes having increased pore densities and process for making the same
Inventors:
Harold Fisher, Daniel Leone, James J. Lowery
Patented Case
View Patent ↗
Granted: May 7, 1991
Filed: Nov 9, 1989
Inventors
Harold Fisher
Daniel Leone
James J. Lowery
Assignee (at issue)
Hoechst Celanese 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.