Granted Patent
Utility
US 6,806,350 · App. 10/362,512
Washing process for the purification of polymers containing N or amino, ammonium or spirobicyclic ammonium groups
Inventors:
Michael Stanek, Regina Schitter, Gerhard Steinbauer, Gerald Summer, Peter Hildebrand
Patented Case
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Granted: Oct 19, 2004
Filed: Feb 24, 2003
Inventors
Michael Stanek
Regina Schitter
Gerhard Steinbauer
Gerald Summer
Peter Hildebrand
Assignee (at issue)
DSM Fine Chemicals Austria NFG GmbH & Co KG
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.