Granted Patent
Utility
US 6,332,949 · App. 09/269,633
Method for upgrading used sulfuric acids
Inventors:
Heiko Beckhaus, Jurgen Munnig, Wolfgang Lorenz, Karl-Heinz Schumacher
Patented Case
View Patent ↗
Granted: Dec 25, 2001
Filed: Mar 30, 1999
Inventors
Heiko Beckhaus
Jurgen Munnig
Wolfgang Lorenz
Karl-Heinz Schumacher
Assignee (at issue)
Bayer Aktiengesellschaft
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.