Granted Patent
Utility
US 5,639,719 · App. 08/605,088
Lubricating oil containing aromatic ether compounds
Inventors:
Masahide Tanaka, Masayasu Ishibashi, Takashi Hayashi, Hajime Oyoshi, Tetsuo Hayashi, Kinya Mizui
Patented Case
View Patent ↗
Granted: Jun 17, 1997
Filed: Mar 6, 1996
Inventors
Masahide Tanaka
Masayasu Ishibashi
Takashi Hayashi
Hajime Oyoshi
Tetsuo Hayashi
Kinya Mizui
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.