Granted Patent
Utility
US 4,302,403 · App. 06/171,450
Process for reacting sulfuric acid and an aromatic hydrocarbon to purify a disulfonic acid product of an aromatic hydrocarbon
Inventors:
Kenneth G. Reabe, Hans Dressler, Frederick M. Covelli
Patented Case
View Patent ↗
Granted: Nov 24, 1981
Filed: Jul 23, 1980
Inventors
Kenneth G. Reabe
Hans Dressler
Frederick M. Covelli
Assignee (at issue)
KOPPERS, INC.
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.