Granted Patent
Utility
US 4,256,567 · App. 06/079,227
Treatment of petroleum stocks containing metals
Inventor:
David B. Bartholic
Patented Case
View Patent ↗
Granted: Mar 17, 1981
Filed: Sep 26, 1979
Inventor
David B. Bartholic
Assignee (at issue)
Engelhard Minerals & Chemicals 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.