Granted Patent
Utility
US 4,390,669 · App. 06/266,593
Process for multi-step gas-phase polymerization of olefins
Inventors:
Yoshinori Morita, Shinzi Hayata, Akifumi Kato, Hideo Nara, Tohru Watanabe
Patented Case
View Patent ↗
Granted: Jun 28, 1983
Filed: May 22, 1981
Inventors
Yoshinori Morita
Shinzi Hayata
Akifumi Kato
Hideo Nara
Tohru Watanabe
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.