Granted Patent
Utility
US 5,129,996 · App. 07/681,794
Lower alkylene oxide purification
Inventor:
T. Thomas Shih
Patented Case
View Patent ↗
Granted: Jul 14, 1992
Filed: Apr 8, 1991
Inventor
T. Thomas Shih
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.