Granted Patent
Utility
US 4,812,436 · App. 07/124,864
Metal-oxide-silica adsorbent for bleaching and refining oil
Inventors:
Leendert H. Staal, Jan C. Vis, Jan W. Groeneweg
Patented Case
View Patent ↗
Granted: Mar 14, 1989
Filed: Nov 24, 1987
Inventors
Leendert H. Staal
Jan C. Vis
Jan W. Groeneweg
Assignee (at issue)
Unilever Patent Holdings B.V.
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.