Granted Patent
Utility
US 4,530,889 · App. 06/229,208
Acidified powdered interleaving
Inventors:
Paul F. Duffer, Helmut Franz, Joseph D. Kelly
Patented Case
View Patent ↗
Granted: Jul 23, 1985
Filed: Jan 28, 1981
Inventors
Paul F. Duffer
Helmut Franz
Joseph D. Kelly
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.