Granted Patent
Utility
US 5,212,313 · App. 07/781,589
Polycyclic dyes
Inventors:
Ronald W. Kenyon, David F. Newton, Derek Thorp
Patented Case
View Patent ↗
Granted: May 18, 1993
Filed: Oct 23, 1991
Inventors
Ronald W. Kenyon
David F. Newton
Derek Thorp
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.