Granted Patent
Utility
US 4,802,891 · App. 07/171,152
Coal-methanol slurry and its production process
Inventors:
Izumi Yamada, Tetsuya Oishi, Kazuhiko Hanashita
Patented Case
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Granted: Feb 7, 1989
Filed: Mar 21, 1988
Inventors
Izumi Yamada
Tetsuya Oishi
Kazuhiko Hanashita
Assignees (at issue)
MITSUI MINING COMPANY, LIMITED
Mitsui Toatsu Chemicals, Incorporated
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.