Granted Patent
Utility
US 5,032,671 · App. 07/576,865
Preparation of lactone polymers using double metal cyanide catalysts
Inventor:
Stephen D. Harper
Patented Case
View Patent ↗
Granted: Jul 16, 1991
Filed: Sep 4, 1990
Inventor
Stephen D. Harper
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.