Granted Patent
Utility
US 5,843,337 · App. 08/905,427
Treatment of aqueous systems using a chemically modified tannin
Inventors:
David B. Mitchell, Ralph L. Minnis, Thomas Peter Curran, Steven M Deboo, John A. Kelly, Rashmi Patwardhan, Wun Ten Tai
Patented Case
View Patent ↗
Granted: Dec 1, 1998
Filed: Aug 4, 1997
Inventors
David B. Mitchell
Ralph L. Minnis
Thomas Peter Curran
Steven M Deboo
John A. Kelly
Rashmi Patwardhan
Wun Ten Tai
Assignee (at issue)
Betzdearborn, 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.