Granted Patent
Utility
US 5,329,021 · App. 08/081,947
Process for the production of pure vinyl pyrrolidone
Inventors:
Jeffrey M. Cohen, Russell B. Biss
Patented Case
View Patent ↗
Granted: Jul 12, 1994
Filed: Feb 4, 1993
Inventors
Jeffrey M. Cohen
Russell B. Biss
Assignee (at issue)
ISP INVESTMENTS 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.