Granted Patent
Utility
US 5,211,862 · App. 07/481,771
Substituted N-thiomethylphenothiazines as lubricant stabilizers
Inventor:
John D. Spivack
Patented Case
View Patent ↗
Granted: May 18, 1993
Filed: Feb 16, 1990
Inventor
John D. Spivack
Assignee (at issue)
Ciba-Geigy
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.