Granted Patent
Utility
US 5,248,784 · App. 07/870,786
4-carbonyl-substituted coumarin compound
Inventors:
Tsukasa Ohyama, Kazuhiko Murayama, Yoriaki Matsuzaki, Susumu Kasamatsu, Keisuke Takuma, Kimitoshi Kato
Patented Case
View Patent ↗
Granted: Sep 28, 1993
Filed: Apr 16, 1992
Inventors
Tsukasa Ohyama
Kazuhiko Murayama
Yoriaki Matsuzaki
Susumu Kasamatsu
Keisuke Takuma
Kimitoshi Kato
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.