Granted Patent
Utility
US 4,212,957 · App. 05/864,553
Plastifiers, method of preparation and PVC compositions containing same
Inventor:
John W. Hirzy
Patented Case
View Patent ↗
Granted: Jul 15, 1980
Filed: Dec 27, 1977
Inventor
John W. Hirzy
Assignee (at issue)
Monsanto 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.