Process of making modified metallocene catalyst, catalyst produced and use thereof

摘要

Olefin polymerization catalysts or catalyst systems comprising a mixture, contact product, reaction product or complex comprising as elements or components: (A) at least one metallocene pre-catalyst compound or polymerization active metallocene compound; (B) at least one titanium containing metallocene compound; and when (A) is a metallocene pre-catalyst compound, (C) at least one activator; provided however: (I) the titanium-containing metallocene compound is inactive or substantially inactive for the polymerization of olefins prior to or concurrently with the use of the catalyst system for olefin polymerization. Also disclosed are processes for producing the catalyst system and polyolefins having desirable combinations of properties, including melt index and molecular weight distribution, which properties are particularly desirable for the manufacture of polyolefin film products, especially LLDPE film A preferred catalyst comprises a zirconium or hafnium metal containing metallocene, an inactivated titanocene and a SiO2 support carrier.

主权项

1. An olefin polymerization catalyst or catalyst system comprising a mixture, contact product, reaction product or complex comprising as elements or components:
(A) at least one metallocene pre-catalyst compound or polymerization-active metallocene compound; (B) at least one titanium-containing metallocene compound;and when (A) is a metallocene pre-catalyst compound,
(C) at least one compound selected from the group consisting of:
(c1) an organoaluminum oxy-compound;(c2) an ionizing ionic compound; and(c3) an organoaluminum compound;provided however:
(I) the titanium-containing metallocene compound is inactive or substantially inactive for the polymerization of olefins; or (II) when the titanium containing metallocene compound is initially active or capable of being activated for olefin polymerization and thus includes titanium which exhibits an oxidation state of Ti+4, the titanium present in the compound is reduced to an oxidation state of Ti+3 so that the titanium containing metallocene compound is inactive or substantially inactive prior to or concurrently with the use of the catalyst system for olefin polymerization; wherein substantially inactive means that the titanium compound will produce less than about 50% of the amount of polyolefin compared to its polymerization-active counterpart.