Granted Patent
Utility
US 4,384,047 · App. 06/341,956
Porous vinylidene fluoride polymer membrane and process for its preparation
Inventors:
William D. Benzinger, Donald N. Robinson
Patented Case
View Patent ↗
Granted: May 17, 1983
Filed: Jan 22, 1982
Inventors
William D. Benzinger
Donald N. Robinson
Assignee (at issue)
Pennwalt 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.