Granted Patent
Utility
US 5,238,989 · App. 07/820,668
Polypropylene resin composition
Inventors:
Hiroshi Takei, Rikio Yonaiyama, Michio Kasai, Nobukazu Atsumi
Patented Case
View Patent ↗
Granted: Aug 24, 1993
Filed: Jan 16, 1992
Inventors
Hiroshi Takei
Rikio Yonaiyama
Michio Kasai
Nobukazu Atsumi
Assignee (at issue)
Chisso 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.