Catalytic system which can be used for the stereospecific polymerization of .alpha.-olefins, process for this polymerization and polymers obtained

Granted: Dec 14, 1999 Filed: Feb 6, 1997

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.