Granted Patent
Utility
US 4,556,738 · App. 06/454,973
Process for preparation of 3,3'- or 3,4'-diamino benzophenone
Inventors:
Saburo Kawashima, Akihiro Yamaguchi
Patented Case
View Patent ↗
Granted: Dec 3, 1985
Filed: Jan 3, 1983
Inventors
Saburo Kawashima
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.