Granted Patent
Utility
US 4,883,908 · App. 07/305,356
Process for the preparation of aromatic isocyanates from dialkyl ureas using an organic sulfonic acid promoter
Inventors:
Edward T. Shawl, Haven S. Kesling, Jr., Frank J. Liotta, Jr.
Patented Case
View Patent ↗
Granted: Nov 28, 1989
Filed: Feb 2, 1989
Inventors
Edward T. Shawl
Haven S. Kesling, Jr.
Frank J. Liotta, Jr.
Assignee (at issue)
Arco Chemical Technology, L.P.
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.