Granted Patent
Utility
US 4,990,479 · App. 07/366,547
Process for polymerizing olefins and polymerization catalyst therefor
Inventors:
Naoshi Ishimaru, Mamoru Kioka, Akinori Toyota
Patented Case
View Patent ↗
Granted: Feb 5, 1991
Filed: Jun 15, 1989
Inventors
Naoshi Ishimaru
Mamoru Kioka
Akinori Toyota
Assignee (at issue)
Mitsui Petrochemical Industries, 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.