Granted Patent
Utility
US 4,306,052 · App. 06/190,724
Thermoplastic polyester polyurethanes
Inventors:
Henry W. Bonk, Richard W. Oertel, III
Patented Case
View Patent ↗
Granted: Dec 15, 1981
Filed: Sep 25, 1980
Inventors
Henry W. Bonk
Richard W. Oertel, III
Assignee (at issue)
The Upjohn Co.
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.