Granted Patent
Utility
US 4,818,612 · App. 07/039,679
Process for the production of pitch-type carbon fibers
Inventors:
Ryuichi Hara, Masami Kagizaki, Tsuyoshi Takakura, Shigeki Tomono
Patented Case
View Patent ↗
Granted: Apr 4, 1989
Filed: Apr 20, 1987
Inventors
Ryuichi Hara
Masami Kagizaki
Tsuyoshi Takakura
Shigeki Tomono
Assignee (at issue)
Mitsubishi Chemical 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.