Granted Patent
Utility
US 4,920,217 · App. 07/245,490
Production of dimethylaminomethyl copper phthalocyanine
Inventors:
Ian A. Lambie, Paul I. W. Yarrow, Robert Langley, Colin D. Campbell
Patented Case
View Patent ↗
Granted: Apr 24, 1990
Filed: Sep 19, 1988
Inventors
Ian A. Lambie
Paul I. W. Yarrow
Robert Langley
Colin D. Campbell
Assignee (at issue)
Ciba-Geigy
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.