Granted Patent
Utility
US 4,273,702 · App. 06/118,290
Cobalt aluminate internal colorants for diol bis (allyl carbonate)
Inventor:
Ivan R. Leatherman
Patented Case
View Patent ↗
Granted: Jun 16, 1981
Filed: Feb 4, 1980
Inventor
Ivan R. Leatherman
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.