Granted Patent
Utility
US 5,252,693 · App. 07/693,375
Syndiotactic styrene polymers
Inventors:
Nobuhide Ishihara, Masahiko Kuramoto, Michitake Uoi
Patented Case
View Patent ↗
Granted: Oct 12, 1993
Filed: Apr 30, 1991
Inventors
Nobuhide Ishihara
Masahiko Kuramoto
Michitake Uoi
Assignee (at issue)
IDEMITSU KOSAN CO., 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.