Granted Patent
Utility
US 5,229,502 · App. 07/483,144
Preparation of 1:2 chromium complexes one sulfo substituted and one sulfonamido or the like substituted azo dyes
Inventors:
Gerhard Back, Alois Puntener
Patented Case
View Patent ↗
Granted: Jul 20, 1993
Filed: Feb 21, 1990
Inventors
Gerhard Back
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.