Granted Patent
Utility
US 5,220,040 · App. 07/808,899
Mixed and mixed crystal benzodefuranone dyes
Inventors:
Leslie A. Mather, David Brierley, James F. Bullock, Nigel Hughes, Prakash Patel
Patented Case
View Patent ↗
Granted: Jun 15, 1993
Filed: Dec 18, 1991
Inventors
Leslie A. Mather
David Brierley
James F. Bullock
Nigel Hughes
Prakash Patel
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.