Granted Patent
Utility
US 5,208,365 · App. 07/898,201
Process for the preparation of 2,5-di(phenylamino)-terephthalic acid and its dialkyl esters in high purity
Inventors:
Hermann Fuchs, Walter Gilb, Otto Arndt
Patented Case
View Patent ↗
Granted: May 4, 1993
Filed: Jun 11, 1992
Inventors
Hermann Fuchs
Walter Gilb
Otto Arndt
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.