Granted Patent
Utility
US 4,921,945 · App. 07/198,266
Disazo dyes containing an acetoacetabukube coupling component and a quaternized aminoalkylene aminocarbonyl group bound to it
Inventor:
Willy Stingelin
Patented Case
View Patent ↗
Granted: May 1, 1990
Filed: May 25, 1988
Inventor
Willy Stingelin
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.