Granted Patent
Utility
US 4,496,774 · App. 06/633,717
Complex formed to separate nitrated phenolic compounds from other phenolic compounds
Inventor:
Gerd Leston
Patented Case
View Patent ↗
Granted: Jan 29, 1985
Filed: Jul 23, 1984
Inventor
Gerd Leston
Assignee (at issue)
KOPPERS, INC.
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.