Granted Patent
Utility
US 5,639,829 · App. 08/486,641
Polypropylene composition
Inventors:
Masayoshi Yamaguchi, Akio Ishimoto, Hiroshi Wakumoto, Masahiro Sugi
Patented Case
View Patent ↗
Granted: Jun 17, 1997
Filed: Jun 7, 1995
Inventors
Masayoshi Yamaguchi
Akio Ishimoto
Hiroshi Wakumoto
Masahiro Sugi
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.