Granted Patent
Utility
US 5,149,891 · App. 07/683,347
Method for preparing pitch fluoride
Inventors:
Takeshi Morimoto, Mikio Sasabe, Toshiyuki Maeda, Hiroyuki Fujimoto
Patented Case
View Patent ↗
Granted: Sep 22, 1992
Filed: Apr 10, 1991
Inventors
Takeshi Morimoto
Mikio Sasabe
Toshiyuki Maeda
Hiroyuki Fujimoto
Assignee (at issue)
Osaka Gas 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.