Granted Patent
Utility
US 4,585,876 · App. 06/551,768
Novel xanthones and thioxanthones
Inventors:
Walter Fischer, Jurgen Finter, Hans Zweifel
Patented Case
View Patent ↗
Granted: Apr 29, 1986
Filed: Nov 14, 1983
Inventors
Walter Fischer
Jurgen Finter
Hans Zweifel
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.