Granted Patent
Utility
US 5,496,898 · App. 08/219,338
Star polymers of dienes, vinylarenes and alkyl methacrylates as modified viscosity index improvers
Inventors:
Robert J. Sutherland, Donn A. DuBois
Patented Case
View Patent ↗
Granted: Mar 5, 1996
Filed: Mar 29, 1994
Inventors
Robert J. Sutherland
Donn A. DuBois
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.