Granted Patent
Utility
US 4,985,152 · App. 07/380,086
Process for separating solvents used in the purification of products
Inventors:
Josef Hilbig, Guenther Welt, Manfred Ziegelmayer
Patented Case
View Patent ↗
Granted: Jan 15, 1991
Filed: Jul 14, 1989
Inventors
Josef Hilbig
Guenther Welt
Manfred Ziegelmayer
Assignee (at issue)
Hoechst GmbH
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.