Granted Patent
Utility
US 5,580,422 · App. 08/097,695
Brightening color dyed wastepaper with a bleaching agent and a quaternary compound
Inventors:
Glynn A. Hamilton, Paul W. Shepperd, III
Patented Case
View Patent ↗
Granted: Dec 3, 1996
Filed: Jul 27, 1993
Inventors
Glynn A. Hamilton
Paul W. Shepperd, III
Assignee (at issue)
Hoechst Celanese Corporation
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.