Granted Patent
Utility
US 4,454,348 · App. 06/434,096
Manufacture of diphenylamine
Inventors:
John Edward Aiken, Marvin C. Fields, Robert Stickel
Patented Case
View Patent ↗
Granted: Jun 12, 1984
Filed: Oct 13, 1982
Inventors
John Edward Aiken
Marvin C. Fields
Robert Stickel
Assignee (at issue)
United States Steel Corporation
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.