Granted Patent
Utility
US 4,937,318 · App. 07/254,701
Aromatic amine resins
Inventors:
Keizaburo Yamaguchi, Yoshimitsu Tanabe, Tatsuhiro Urakami, Akihiro Yamaguchi, Norimasa Yamaya, Masahiro Ohta
Patented Case
View Patent ↗
Granted: Jun 26, 1990
Filed: Oct 7, 1988
Inventors
Keizaburo Yamaguchi
Yoshimitsu Tanabe
Tatsuhiro Urakami
Akihiro Yamaguchi
Norimasa Yamaya
Masahiro Ohta
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.