Granted Patent
Utility
US 5,458,792 · App. 08/289,487
Asymmetric triblock copolymer viscosity index improver for oil compositions
Inventors:
Robert B. Rhodes, Craig A. Stevens
Patented Case
View Patent ↗
Granted: Oct 17, 1995
Filed: Aug 11, 1994
Inventors
Robert B. Rhodes
Craig A. Stevens
Assignee (at issue)
SHELL OIL COMPANY
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.