Granted Patent
Utility
US 5,223,472 · App. 07/868,775
Demetallation catalyst
Inventors:
Howard D. Simpson, Milan Skripek
Patented Case
View Patent ↗
Granted: Jun 29, 1993
Filed: Apr 14, 1992
Inventors
Howard D. Simpson
Milan Skripek
Assignee (at issue)
Union Oil Company of California
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.