Granted Patent
Utility
US 4,385,182 · App. 06/258,267
Thioxanthonecarboxylic acids and thioxanthonecarboxylic acid derivatives
Inventors:
Walter Fischer, Vratislav Kvita, Hans Zweifel, Louis Felder
Patented Case
View Patent ↗
Granted: May 24, 1983
Filed: Apr 28, 1981
Inventors
Walter Fischer
Vratislav Kvita
Hans Zweifel
Louis Felder
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.