Granted Patent
Utility
US 5,149,850 · App. 07/726,625
Process for the production of high-purity tetrachloro-1,4-benzoquinone
Inventors:
Otto Arndt, Theodor Papenfuhs
Patented Case
View Patent ↗
Granted: Sep 22, 1992
Filed: Jun 28, 1991
Inventors
Otto Arndt
Theodor Papenfuhs
Assignee (at issue)
Hoechst GmbH
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.