Granted Patent
Utility
US 4,465,639 · App. 06/461,247
Process for polyisocyanates
Inventor:
Richard Hatfield, Jr.
Patented Case
View Patent ↗
Granted: Aug 14, 1984
Filed: Jan 26, 1983
Inventor
Richard Hatfield, Jr.
Assignee (at issue)
The Upjohn Co.
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.