Granted Patent
Utility
US 4,973,411 · App. 07/407,824
Process for the preparation of sulfurized overbased phenate detergents
Inventors:
Tze-Chi Jao, Carl K. Esche, Jr., Elzie D. Black, Robert H. Jenkins, Jr.
Patented Case
View Patent ↗
Granted: Nov 27, 1990
Filed: Sep 15, 1989
Inventors
Tze-Chi Jao
Carl K. Esche, Jr.
Elzie D. Black
Robert H. Jenkins, Jr.
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.