Granted Patent
Utility
US 4,853,442 · App. 07/033,563
Amine-terminated polysulfone sulfide, useful as epoxy curing agent
Inventor:
Tuyen T. Nguyen
Patented Case
View Patent ↗
Granted: Aug 1, 1989
Filed: Apr 3, 1987
Inventor
Tuyen T. Nguyen
Assignee (at issue)
HERCULES LLC
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.