Granted Patent
Utility
US 5,246,657 · App. 07/867,347
Process of making polyolefin fiber
Inventors:
Kazuo Yagi, Hiroyuki Takeda
Patented Case
View Patent ↗
Granted: Sep 21, 1993
Filed: Apr 13, 1992
Inventors
Kazuo Yagi
Hiroyuki Takeda
Assignee (at issue)
Mitsui Petrochemical 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.