Granted Patent
Utility
US 6,271,420 · App. 09/552,777
Preparation of quinonediimines from phenylenediamines using hydrogen peroxide and a catalyst
Inventor:
Raymond Anton Lohr, Jr.
Patented Case
View Patent ↗
Granted: Aug 7, 2001
Filed: Apr 21, 2000
Inventor
Raymond Anton Lohr, Jr.
Assignee (at issue)
Flexsys America L.P.
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.