Granted Patent
Utility
US 5,478,950 · App. 08/284,545
Process for producing pyrrolidone and N-alkyl pyrrolidones
Inventors:
Manfred Bergfeld, Gunter Wiesgickl
Patented Case
View Patent ↗
Granted: Dec 26, 1995
Filed: Aug 8, 1994
Inventors
Manfred Bergfeld
Gunter Wiesgickl
Assignee (at issue)
AKZO NOBEL N.V.
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.