Granted Patent
Utility
US 4,304,725 · App. 06/148,444
Process for producing disperse dyes
Inventor:
Hansrudolf Schwander
Patented Case
View Patent ↗
Granted: Dec 8, 1981
Filed: May 9, 1980
Inventor
Hansrudolf Schwander
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.