Granted Patent
Utility
US 5,171,921 · App. 07/692,333
Production of olefins
Inventors:
Anne Mae Gaffney, John A. Sofranko
Patented Case
View Patent ↗
Granted: Dec 15, 1992
Filed: Apr 26, 1991
Inventors
Anne Mae Gaffney
John A. Sofranko
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.