Granted Patent
Utility
US 5,071,898 · App. 07/360,801
Propane-1,3-dione derivatives and their use as stabilizers for polymers containing chlorine
Inventors:
Hermann O. Wirth, Hans-Helmut Friedrich, Gerd Abeler
Patented Case
View Patent ↗
Granted: Dec 10, 1991
Filed: Jun 2, 1989
Inventors
Hermann O. Wirth
Hans-Helmut Friedrich
Gerd Abeler
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.