Granted Patent
Utility
US 4,633,018 · App. 06/811,623
Process for separating isomers of toluenediamine
Inventor:
Hermann A. Zinnen
Patented Case
View Patent ↗
Granted: Dec 30, 1986
Filed: Dec 20, 1985
Inventor
Hermann A. Zinnen
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.