Granted Patent
Utility
US 4,980,433 · App. 07/417,355
Novel amine-containing copolymers and their use
Inventors:
Fu Chen, William S. Carey
Patented Case
View Patent ↗
Granted: Dec 25, 1990
Filed: Oct 5, 1989
Inventors
Fu Chen
William S. Carey
Assignee (at issue)
Betz Laboratories, 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.