| abstract |
The present invention provides intercalated, modified and calcined smectite clays comprising: (a) pillars comprising aluminum and: (i) at least one rare earth metal or lanthanide metal; or (ii) at least one rare earth metal or lanthanide metal and gallium; and (b) at least one ion-exchanged metal selected from the group consisting of: aluminum, barium, beryllium, calcium, cerium, cesium, copper, chromium, gadolinium, gallium, germanium, hafnium, holmium, iron (II and III), lanthanum, lithium, magnesium, manganese, neodymium, potassium, praseodymium, rubidium, samarium, silver, selenium, sodium, strontium, tellurium, terbium, thallium, thorium, tin, titanium, uranium, ytterbium, yttrium, zinc and zirconium; wherein the clay is characterized by a bedding spacing d 001 Equal to or greater than about 18.5 angstroms. The modified clay suitably functions as a catalyst support-activator and, preferably, when used in combination with a metallocene catalyst precursor component, in the substantial absence of an alumoxane or boron-containing compound, provides an active catalyst for the polymerization of at least one olefin. |