Granted Patent
Utility
US 4,889,938 · App. 07/229,392
1,4-Oxathianones and 1,4-oxathiepanones
Inventors:
Ulrich Kristen, Hermann O. Wirth
Patented Case
View Patent ↗
Granted: Dec 26, 1989
Filed: Aug 8, 1988
Inventors
Ulrich Kristen
Hermann O. Wirth
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.