Granted Patent
Utility
US 5,340,892 · App. 08/038,089
Process for producing styrene polymers
Inventor:
Masahiko Kuramoto
Patented Case
View Patent ↗
Granted: Aug 23, 1994
Filed: Mar 29, 1993
Inventor
Masahiko Kuramoto
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.