Granted Patent
Utility
US 4,420,592 · App. 06/309,588
Process for multi-step gaseous phase polymerization of olefins
Inventors:
Akifumi Kato, Junichi Yoshida, Ryoichi Yamamoto
Patented Case
View Patent ↗
Granted: Dec 13, 1983
Filed: Oct 8, 1981
Inventors
Akifumi Kato
Junichi Yoshida
Ryoichi Yamamoto
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.