Granted Patent
Utility
US 5,643,494 · App. 08/456,499
Process for the preparation of aromatic hydroxy carboxylic acids
Inventors:
Siegbert Rittner, Hans-Martin Ruffer, Jorg Schmid, Thomas Wisser
Patented Case
View Patent ↗
Granted: Jul 1, 1997
Filed: Jun 1, 1995
Inventors
Siegbert Rittner
Hans-Martin Ruffer
Jorg Schmid
Thomas Wisser
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.