Granted Patent
Utility
US 5,367,096 · App. 07/932,757
Process for the preparation of 2,5-di(phenylamino)terephthalic acid and dialkyl esters thereof in high purity
Inventors:
Eberhard Ritter, Hans-Ludwig Schafer, Thomas Vollheim, Martin Schottler
Patented Case
View Patent ↗
Granted: Nov 22, 1994
Filed: Aug 20, 1992
Inventors
Eberhard Ritter
Hans-Ludwig Schafer
Thomas Vollheim
Martin Schottler
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.