Granted Patent
Utility
US 5,262,504 · App. 07/598,637
Styrene copolymer and process for production thereof
Inventors:
Toshinori Tazaki, Masahiko Kuramoto
Patented Case
View Patent ↗
Granted: Nov 16, 1993
Filed: Oct 19, 1990
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.