Magnesium Dichloride Supported Titanium Catalyst Composition for Polyolefin Polymerization

摘要

In the present disclosure, a Ziegler-Natta catalyst composition for the polymerization of olefin monomers to produce polyolefin with controlled molecular weight distribution is provided wherein said controlled molecular weight distribution ranges from narrow to broad. The desired control over the molecular weight distribution of polyolefin is accomplished by using a Ziegler-Natta catalyst composition having enhanced self-extinguishing property. In the Zeigler-Natta catalyst composition of the present disclosure, in addition to a titanium and magnesium containing pro-catalyst component, a mixture of tri-alkyl aluminum compounds as a co-catalyst mixture is used. The particular combination of tri-alkyl aluminum compounds in a pre-determined weight proportion provides desirable control over the molecular weight distribution of polyolefin.

主权项

1. A catalyst composition for the polymerization of olefins, said catalyst composition comprising;
i. a solid pro-catalyst component containing Ti, Mg and at least one internal electron donor; ii. a co-catalyst component comprising a mixture of at least two trialkyl aluminum compounds selected from the group consisting of triethyl aluminum, triisobutyl aluminum and trioctyl aluminum, said co-catalyst mixture comprises at least one said trialkyl aluminum compound in an amount of at least 10 mole percent, based on the total amount of the co-catalyst mixture; and iii. at least one external electron donor selected from the group of compounds consisting of alkoxysilanes and carboxylic acid esters.