Granted Patent
Utility
US 4,803,258 · App. 07/076,873
Thermoplastic aromatic polyether-pyridine and process for preparing same
Inventors:
Keizaburo Yamaguchi, Hideaki Oikawa, Kenichi Sugimoto, Masahiro Ohta, Akihiro Yamaguchi
Patented Case
View Patent ↗
Granted: Feb 7, 1989
Filed: Jul 23, 1987
Inventors
Keizaburo Yamaguchi
Hideaki Oikawa
Kenichi Sugimoto
Masahiro Ohta
Akihiro Yamaguchi
Assignee (at issue)
Mitsui Toatsu Chemicals, Incorporated
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.