Granted Patent
Utility
US 4,990,640 · App. 07/407,435
Benzene-insoluble organoaluminum oxy-compounds and process for preparing same
Inventors:
Toshiyuki Tsutsui, Mamoru Kioka, Akinori Toyota
Patented Case
View Patent ↗
Granted: Feb 5, 1991
Filed: Sep 14, 1989
Inventors
Toshiyuki Tsutsui
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.