Granted Patent
Utility
US 4,767,553 · App. 06/945,982
Lubricating oil containing dispersant viscosity index improver
Inventors:
William P. Hart, Maria M. Kapuscinski, Christopher S. Liu
Patented Case
View Patent ↗
Granted: Aug 30, 1988
Filed: Dec 24, 1986
Inventors
William P. Hart
Maria M. Kapuscinski
Christopher S. Liu
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.