Granted Patent
Utility
US 4,822,851 · App. 06/947,179
Process for the preparation of cationized polyvinyl alcohol
Inventors:
Reinhard Stober, Ellen Kohn, Dietmar Bischoff
Patented Case
View Patent ↗
Granted: Apr 18, 1989
Filed: Dec 29, 1986
Inventors
Reinhard Stober
Ellen Kohn
Dietmar Bischoff
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.