Granted Patent
Utility
US 4,304,939 · App. 05/957,263
Preparation of N-phenyl-N-alkylphenylenediamines
Inventor:
Ted Symon
Patented Case
View Patent ↗
Granted: Dec 8, 1981
Filed: Nov 2, 1978
Inventor
Ted Symon
Assignee (at issue)
UOP LLC
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.