Granted Patent
Utility
US 5,252,737 · App. 07/887,981
Process for preparing N-aliphatic substituted p-phenylenediamines
Inventors:
Michael K. Stern, Brian K. Cheng
Patented Case
View Patent ↗
Granted: Oct 12, 1993
Filed: May 22, 1992
Inventors
Michael K. Stern
Brian K. Cheng
Assignee (at issue)
Monsanto Company
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.