Granted Patent
Utility
US 5,132,033 · App. 07/607,960
Method of preparing overbased calcium sulfonates
Inventors:
Tze-Chi Jao, Jayne M. Vaccaro, Elzie D. Black
Patented Case
View Patent ↗
Granted: Jul 21, 1992
Filed: Nov 1, 1990
Inventors
Tze-Chi Jao
Jayne M. Vaccaro
Elzie D. Black
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.