Granted Patent
Utility
US 4,909,902 · App. 07/290,559
Alkali metal Kurrol's salt as a paper pulp draining aid
Inventors:
Edward J. Griffith, Toan M. Ngo
Patented Case
View Patent ↗
Granted: Mar 20, 1990
Filed: Dec 27, 1988
Inventors
Edward J. Griffith
Toan M. Ngo
Assignee (at issue)
Monsanto Company
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.