Granted Patent
Utility
US 5,391,815 · App. 07/978,702
Method of separating vinylphosphonic acid from crude mixtures
Inventor:
Gunter Roscher
Patented Case
View Patent ↗
Granted: Feb 21, 1995
Filed: Feb 3, 1993
Inventor
Gunter Roscher
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.