Granted Patent
Utility
US 5,057,193 · App. 07/453,370
Anti-tarnish treatment of metal foil
Inventors:
Lifun Lin, Ned W. Polan
Patented Case
View Patent ↗
Granted: Oct 15, 1991
Filed: Dec 22, 1989
Inventors
Lifun Lin
Ned W. Polan
Assignee (at issue)
Olin 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.