Granted Patent
Utility
US 4,542,246 · App. 06/478,946
Electrical insulating oil having high oxidation stability and method for production thereof
Inventors:
Atsushi Matsunaga, Sampo Kusayanagi, Masamitu Takano, Yutaka Kato
Patented Case
View Patent ↗
Granted: Sep 17, 1985
Filed: Mar 25, 1983
Inventors
Atsushi Matsunaga
Sampo Kusayanagi
Masamitu Takano
Yutaka Kato
Assignee (at issue)
Nippon Mining Company Limited
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.