Granted Patent
Utility
US 6,117,825 · App. 07/879,401
Polyisobutylene succinimide and ethylene-propylene succinimide synergistic additives for lubricating oils compositions
Inventors:
Christopher S. Liu, Cyril A. Migdal, Norris Roland Crawford, Roy Isamu Yamamota
Patented Case
View Patent ↗
Granted: Sep 12, 2000
Filed: May 7, 1992
Inventors
Christopher S. Liu
Cyril A. Migdal
Norris Roland Crawford
Roy Isamu Yamamota
Assignee (at issue)
Ethyl Corporation
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.