Granted Patent
Utility
US 4,874,849 · App. 06/944,621
Asymmetric 1:2-chromium complex dyes containing two azo dyes, one containing an acetoacetanilide coupling component
Inventors:
Gerhard Back, Fabic Beffa, Ulrich Schlesinger, Alois Puntener
Patented Case
View Patent ↗
Granted: Oct 17, 1989
Filed: Dec 19, 1986
Inventors
Gerhard Back
Fabic Beffa
Ulrich Schlesinger
Alois Puntener
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.