Granted Patent
Utility
US 4,315,874 · App. 06/137,641
Process for the production of spherical carrier particles for olefin polymerization catalysts
Inventors:
Yoshihisa Ushida, Yoshikatu Amimoto, Akinori Toyota, Norio Kashiwa
Patented Case
View Patent ↗
Granted: Feb 16, 1982
Filed: Apr 7, 1980
Inventors
Yoshihisa Ushida
Yoshikatu Amimoto
Akinori Toyota
Norio Kashiwa
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.