Granted Patent
Utility
US 4,469,555 · App. 06/335,787
Organic pigments
Inventors:
William W. Maslanka, Gavin G. Spence
Patented Case
View Patent ↗
Granted: Sep 4, 1984
Filed: Dec 30, 1981
Inventors
William W. Maslanka
Gavin G. Spence
Assignee (at issue)
HERCULES LLC
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.