Granted Patent
Utility
US 4,515,716 · App. 06/414,733
2,6-Diaminopyridine-based azo dyes for cellulose-containing fibers
Inventors:
Toshio Niwa, Toshio Hihara
Patented Case
View Patent ↗
Granted: May 7, 1985
Filed: Sep 3, 1982
Inventors
Toshio Niwa
Toshio Hihara
Assignee (at issue)
Mitsubishi Chemical Industries, Ltd.
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.