Granted Patent
Utility
US 6,500,311 · App. 09/957,591
Propylene oxide purification
Inventor:
Gary A. Sawyer
Patented Case
View Patent ↗
Granted: Dec 31, 2002
Filed: Sep 21, 2001
Inventor
Gary A. Sawyer
Assignee (at issue)
Arco Chemical Technology, L.P.
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.