Granted Patent
Utility
US 4,861,644 · App. 07/238,684
Printed microporous material
Inventors:
James Young, Dennis D. Leatherman
Patented Case
View Patent ↗
Granted: Aug 29, 1989
Filed: Aug 30, 1988
Inventors
James Young
Dennis D. Leatherman
Assignee (at issue)
PPG Industries, 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.