Granted Patent
Utility
US 5,163,972 · App. 07/621,405
Process for the dyeing of polyacrylonitrile materials with cationic benzo-thiazolium azo dye
Inventors:
Wilfried Herter, Josef Koller
Patented Case
View Patent ↗
Granted: Nov 17, 1992
Filed: Dec 3, 1990
Inventors
Wilfried Herter
Josef Koller
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.