Granted Patent
Utility
US 5,659,039 · App. 08/393,426
Quinophthalone compounds
Inventors:
Akira Ogiso, Rihoko Imai, Tsutami Misawa, Ryu Oi, Yoriaki Matsuzaki, Hisato Itoh
Patented Case
View Patent ↗
Granted: Aug 19, 1997
Filed: Feb 23, 1995
Inventors
Akira Ogiso
Rihoko Imai
Tsutami Misawa
Ryu Oi
Yoriaki Matsuzaki
Hisato Itoh
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.