Granted Patent
Utility
US 4,735,685 · App. 06/773,705
Process for sizing paper or cardboard with anionic hydrophobic sizing agents and cationic retention aids
Inventors:
Michael Bernheim, Hubert Meindl, Peter Rohringer
Patented Case
View Patent ↗
Granted: Apr 5, 1988
Filed: Sep 9, 1985
Inventors
Michael Bernheim
Hubert Meindl
Peter Rohringer
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.