Granted Patent
Utility
US 4,810,396 · App. 07/188,517
Process for preparing overbased calcium sulfonates
Inventors:
Tze-Chi Jao, William J. Powers, III
Patented Case
View Patent ↗
Granted: Mar 7, 1989
Filed: Apr 29, 1988
Inventors
Tze-Chi Jao
William J. Powers, III
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.