Granted Patent
Utility
US 4,374,756 · App. 06/300,710
Vanadium-hydrogen-phosphorus-oxygen catalytic material
Inventors:
Philip H. Harju, Eugene A. Pasek
Patented Case
View Patent ↗
Granted: Feb 22, 1983
Filed: Sep 9, 1981
Inventors
Philip H. Harju
Eugene A. Pasek
Assignee (at issue)
KOPPERS, 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.