Granted Patent
Utility
US 5,750,599 · App. 08/821,194
Quinophthalone compounds and polarizing films using same
Inventors:
Akira Ogiso, Rihoko Imai, Tsutami Misawa, Ryu Oi, Yoriaki Matsuzaki, Hisato Itoh
Patented Case
View Patent ↗
Granted: May 12, 1998
Filed: Mar 19, 1997
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.