Granted Patent
Utility
US 5,015,612 · App. 07/407,437
Olefin polymerization catalyst subjected to preliminary polymerization treatment
Inventors:
Mamoru Kioka, Masao Nakano, Kenji Doi, Akinori Toyota
Patented Case
View Patent ↗
Granted: May 14, 1991
Filed: Sep 14, 1989
Inventors
Mamoru Kioka
Masao Nakano
Kenji Doi
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.