Granted Patent
Utility
US 6,331,651 · App. 09/839,808
Process for making hexamethylene diamine using ozone-treated adiponitrile that contains phosphorous compounds
Inventor:
John J. Ostermaier
Patented Case
View Patent ↗
Granted: Dec 18, 2001
Filed: Apr 20, 2001
Inventor
John J. Ostermaier
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND COMPANY
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.