Granted Patent
Utility
US 4,340,430 · App. 06/174,994
Azo pigments, process for their production and their use
Inventor:
Armand Roueche
Patented Case
View Patent ↗
Granted: Jul 20, 1982
Filed: Aug 4, 1980
Inventor
Armand Roueche
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.