Granted Patent
Utility
US 4,721,807 · App. 07/047,341
Process for separating 2,6-toluene diisocyanate from isomers of toluene diisocyanate
Inventor:
Hermann A. Zinnen
Patented Case
View Patent ↗
Granted: Jan 26, 1988
Filed: May 8, 1987
Inventor
Hermann A. Zinnen
Assignee (at issue)
UOP LLC
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.