OLEFIN TRIMERISATION USING A CATALYST COMPRISING A SOURCE OF CHROMIUM, MOLYBDENUM OR TUNGSTEN AND A LIGAND CONTAINING AT LEAST ONE PHOSPHOROUS, ARSENIC OR ANTIMONY ATOM BOUND TO AT LEAST ONE (HETERO)HYDROCARBYL GROUP

Granted: Oct 5, 2004 Filed: Jan 10, 2003

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.