Granted Patent
Utility
US 3,983,139 · App. 05/552,498
3-(Hydroxyhydrocarbylsecondaryamino)thiophene 1,1-dioxides and polyurethanes chain extended therewith
Inventor:
Chung-Ling Mao
Patented Case
View Patent ↗
Granted: Sep 28, 1976
Filed: Feb 24, 1975
Inventor
Chung-Ling Mao
Assignee (at issue)
Uniroyal Ltd.
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.