Granted Patent
Utility
US 4,412,021 · App. 06/351,577
Novel polyalkylpiperidyl-ureas and their use as stabilizers
Inventor:
Friedrich Karrer
Patented Case
View Patent ↗
Granted: Oct 25, 1983
Filed: Feb 23, 1982
Inventor
Friedrich Karrer
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.