Granted Patent
Utility
US 4,405,329 · App. 06/268,978
Stable concentrated fluid formulations of metal-free dyes, process for their preparation, and their use
Inventors:
Heinz Abel, Paul Hugelshofer
Patented Case
View Patent ↗
Granted: Sep 20, 1983
Filed: Jun 1, 1981
Inventors
Heinz Abel
Paul Hugelshofer
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.