Granted Patent
Utility
US 4,577,013 · App. 06/680,690
Ionically modified cellulose material, its preparation and its use
Inventors:
Jurg Merz, Walter Voser
Patented Case
View Patent ↗
Granted: Mar 18, 1986
Filed: Dec 12, 1984
Inventors
Jurg Merz
Walter Voser
Assignee (at issue)
Ciba-Geigy
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.