Granted Patent
Utility
US 5,616,779 · App. 08/397,733
Process for the preparation of 2,5-di-phenylamino-terephthalic acid and its dialkyl esters
Inventor:
Otto Arndt
Patented Case
View Patent ↗
Granted: Apr 1, 1997
Filed: Mar 2, 1995
Inventor
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.