Granted Patent
Utility
US 4,877,840 · App. 07/144,232
Polyolefin concentrate
Inventor:
Kenneth Chu
Patented Case
View Patent ↗
Granted: Oct 31, 1989
Filed: Jan 15, 1988
Inventor
Kenneth Chu
Assignee (at issue)
DuPont Canada 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.