Granted Patent
Utility
US 4,259,307 · App. 06/115,275
Process for producing carbon fibers
Inventor:
Kunio Maruyama
Patented Case
View Patent ↗
Granted: Mar 31, 1981
Filed: Jan 25, 1980
Inventor
Kunio Maruyama
Assignees (at issue)
SUMITOMO CHEMICAL COMPANY, LIMITED
JAPAN EXLAN 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.