Granted Patent
Utility
US 4,246,410 · App. 05/795,459
Naphtholactam dyestuffs
Inventors:
Hansrudolf Schwander, Christian Zickendraht
Patented Case
View Patent ↗
Granted: Jan 20, 1981
Filed: May 10, 1977
Inventors
Hansrudolf Schwander
Christian Zickendraht
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.