Granted Patent
Utility
US 5,647,896 · App. 08/544,986
Color-developing agents and color-developing sheets
Inventors:
Takeshi Nishimura, Tomoko Kamashita, Masaru Wada, Teruyuki Nagata, Yoshimitsu Tanabe, Kiyoharu Hasegawa, Masakatsu Nakatsuka
Patented Case
View Patent ↗
Granted: Jul 15, 1997
Filed: Oct 30, 1995
Inventors
Takeshi Nishimura
Tomoko Kamashita
Masaru Wada
Teruyuki Nagata
Yoshimitsu Tanabe
Kiyoharu Hasegawa
Masakatsu Nakatsuka
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.