Granted Patent
Utility
US 4,818,374 · App. 06/795,729
Process for converting coal to an oil fraction
Inventors:
Nobuyoshi Hirokoh, Yoichi Kageyama, Yukio Nakako, Tetsuo Matsumura
Patented Case
View Patent ↗
Granted: Apr 4, 1989
Filed: Nov 8, 1985
Inventors
Nobuyoshi Hirokoh
Yoichi Kageyama
Yukio Nakako
Tetsuo Matsumura
Assignees (at issue)
Mitsubishi Chemical Industries, Ltd.
Kabushiki Kaisha Kobe Seiko Sho
IDEMITSU KOSAN CO., LTD.
Asia Oil Company Limited
Nippon Brown Coal Liquefaction Co., 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.