Granted Patent
Utility
US 5,126,450 · App. 07/607,707
Unsymmetrical triphenodioxazine dyes
Inventor:
Peter C. Smith
Patented Case
View Patent ↗
Granted: Jun 30, 1992
Filed: Nov 1, 1990
Inventor
Peter C. Smith
Assignee (at issue)
IMPERIAL CHEMICAL INDUSTRIES LIMITED
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.