Granted Patent
Utility
US 4,877,834 · App. 07/190,860
Lubricating oil containing a Mannich base
Inventors:
Christopher S. Liu, Donald J. Clarke, Larry D. Grina
Patented Case
View Patent ↗
Granted: Oct 31, 1989
Filed: May 6, 1988
Inventors
Christopher S. Liu
Donald J. Clarke
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.