Granted Patent
Utility
US 5,800,719 · App. 08/856,218
Method for dewatering drinking sludge using a water soluble block copolymer
Inventors:
Frank J. Sutman, Richard A. Hobirk
Patented Case
View Patent ↗
Granted: Sep 1, 1998
Filed: May 14, 1997
Inventors
Frank J. Sutman
Richard A. Hobirk
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.