Granted Patent
Utility
US 5,797,987 · App. 08/572,434
Zinc phosphate conversion coating compositions and process
Inventor:
Charles E. Rossio
Patented Case
View Patent ↗
Granted: Aug 25, 1998
Filed: Dec 14, 1995
Inventor
Charles E. Rossio
Assignee (at issue)
PPG Industries, Inc.
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.