Granted Patent
Utility
US 5,447,901 · App. 08/297,525
Color-developing compositions and their use
Inventors:
Keizaburo Yamaguchi, Yoshimitsu Tanabe, Kiyoharu Hasegawa, Akihiro Yamaguchi
Patented Case
View Patent ↗
Granted: Sep 5, 1995
Filed: Aug 26, 1994
Inventors
Keizaburo Yamaguchi
Yoshimitsu Tanabe
Kiyoharu Hasegawa
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.