Granted Patent
Utility
US 5,319,138 · App. 07/926,495
Process for the preparation of pure propanephosphonic anhydride
Inventors:
Gunter Roscher, Hans-Jerg Kleiner, Harald Berger, Manfred Schmidt, Rainer Uhmann, Dirk Bottger
Patented Case
View Patent ↗
Granted: Jun 7, 1994
Filed: Aug 5, 1992
Inventors
Gunter Roscher
Hans-Jerg Kleiner
Harald Berger
Manfred Schmidt
Rainer Uhmann
Dirk Bottger
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.