Granted Patent
Utility
US 4,252,909 · App. 06/018,048
Free-expandable rubbery composition
Inventors:
Kiyoshi Honma, Hidekuni Oda
Patented Case
View Patent ↗
Granted: Feb 24, 1981
Filed: Mar 6, 1979
Inventors
Kiyoshi Honma
Hidekuni Oda
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.