Granted Patent
Utility
US 5,830,267 · App. 08/642,178
Coloration of high molecular weight organic materials in the mass with soluble phthalocyanine precursors
Inventors:
John S. Zambounis, Heinz Wolleb
Patented Case
View Patent ↗
Granted: Nov 3, 1998
Filed: May 6, 1996
Inventors
John S. Zambounis
Heinz Wolleb
Assignee (at issue)
Ciba Specialty Chemicals Corporation
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.