Granted Patent
Utility
US 4,731,289 · App. 06/935,107
Abrasion resistant polyurethane coatings for rigid plastics
Inventor:
Charles R. Coleman
Patented Case
View Patent ↗
Granted: Mar 15, 1988
Filed: Nov 24, 1986
Inventor
Charles R. Coleman
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.