Granted Patent
Utility
US 4,904,404 · App. 07/320,187
Lubricating oil containing viscosity index improver
Inventors:
Christopher S. Liu, Nicholas Benfaremo, Maria M. Kapuscinski, Larry D. Grina
Patented Case
View Patent ↗
Granted: Feb 27, 1990
Filed: Mar 7, 1989
Inventors
Christopher S. Liu
Nicholas Benfaremo
Maria M. Kapuscinski
Larry D. Grina
Assignee (at issue)
Texaco Inc.
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.