Granted Patent
Utility
US 4,814,390 · App. 07/133,425
Chlorinated rubber
Inventors:
Tetsuo Tojo, Takashi Nakahara, Yasuhiko Otawa, Katsuo Okamoto
Patented Case
View Patent ↗
Granted: Mar 21, 1989
Filed: Dec 15, 1987
Inventors
Tetsuo Tojo
Takashi Nakahara
Yasuhiko Otawa
Katsuo Okamoto
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.