Granted Patent
Utility
US 5,391,671 · App. 08/088,523
Styrene copolymer and process for production thereof
Inventors:
Toshinori Tazaki, Masahiko Kuramoto
Patented Case
View Patent ↗
Granted: Feb 21, 1995
Filed: Jul 9, 1993
Inventors
Toshinori Tazaki
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.