Granted Patent
Utility
US 4,990,232 · App. 07/240,166
Process for the preparation of carbodiimides
Inventor:
Alex Alder
Patented Case
View Patent ↗
Granted: Feb 5, 1991
Filed: Sep 2, 1988
Inventor
Alex Alder
Assignee (at issue)
Ciba-Geigy
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.