Granted Patent
Utility
US 4,309,294 · App. 06/171,863
N,N'-Disubstituted 2,4'-diaminodiphenyl ethers as antioxidants
Inventor:
John T. Roberts
Patented Case
View Patent ↗
Granted: Jan 5, 1982
Filed: Jul 24, 1980
Inventor
John T. Roberts
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.