Granted Patent
Utility
US 4,402,882 · App. 06/295,170
Process for the production of diphosphaspiro compounds
Inventor:
Jurg Kiefer
Patented Case
View Patent ↗
Granted: Sep 6, 1983
Filed: Aug 21, 1981
Inventor
Jurg Kiefer
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.