Granted Patent
Utility
US 5,001,191 · App. 07/438,070
Process for dry cationization of polyvinyl alcohol
Inventors:
Reinhard Stober, Dietmar Bischoff, Ellen Kohn
Patented Case
View Patent ↗
Granted: Mar 19, 1991
Filed: Nov 20, 1989
Inventors
Reinhard Stober
Dietmar Bischoff
Ellen Kohn
Assignee (at issue)
Degussa AG
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.