Granted Patent
Utility
US 4,923,692 · App. 07/253,402
Process for producing pitch-type carbon fibers
Inventors:
Akira Nakagoshi, Hiroshi Tahara, Tetuo Yamada, Hiroyuki Sekiguchi, Hidemi Murata
Patented Case
View Patent ↗
Granted: May 8, 1990
Filed: Oct 3, 1988
Inventors
Akira Nakagoshi
Hiroshi Tahara
Tetuo Yamada
Hiroyuki Sekiguchi
Hidemi Murata
Assignee (at issue)
Mitsubishi Kasei Corporation
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.