Granted Patent
Utility
US 4,824,947 · App. 07/162,514
Substituted phthalocyanine
Inventor:
William M. Stark
Patented Case
View Patent ↗
Granted: Apr 25, 1989
Filed: Mar 1, 1988
Inventor
William M. Stark
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.