A catalyst system including a procatalyst, a co-catalyst and an external electron donor of Formula I:
Si(L).sub.n(OR.sup.11).sub.4-n-m(R.sup.12).sub.mFormula I wherein, Si has a valency 4+; O has a valency 2 and O is bonded to Si via a silicon-oxygen bond; n is 1-4; m is 0-3; n+m4; each R.sup.11 and R.sup.12 group is independently an alkyl or aromatic substituted or unsubstituted hydrocarbyl;
each L group is independently of Formula II: ##STR00001## wherein, L is bonded to the silicon atom via the nitrogen-silicon bond; L has a single substituent on the nitrogen atom, where this single substituent is an imine carbon atom; and X and Y are independently a hydrogen atom; a heteroatom of Groups 13-17; an alkyl, optionally containing a heteroatom of Groups 13-17 or an aromatic substituted and unsubstituted hydrocarbyl, optionally containing a heteroatom of Groups 13-17.

Methods for making olefin polymerization catalysts and methods for making polyethylene polymers using the catalysts are provided. The polyethylenes can have a molecular weight distribution (MWD) of about 4.5 to about 14, a slope of strain hardening greater than about 0.75, and a melt flow ratio (MFR) greater than or equal to 8.33+(4.17MWD).

Methods for making olefin polymerization catalysts and methods for making polyethylene polymers using the catalysts are provided. The polyethylenes can have a molecular weight distribution (MWD) of about 4.5 to about 14, a slope of strain hardening greater than about 0.75, and a melt flow ratio (MFR) greater than or equal to 8.33+(4.17MWD).

Compositions useful in propylene polymerization catalysts, and in particular solid, hydrocarbon-insoluble, catalyst compositions containing magnesium, titanium, and halogen and further comprising a modifier compound with structure (1):

##STR00001## wherein Q1 is an oxygen containing group selected from CH.sub.2OR.sup.1, C(O)R.sup.1 and C(O)OR.sup.1 and Q2 is selected from R.sup.2 and OR.sup.2; R.sup.1 to R.sup.5 each being independently selected from H, alkyl, aryl, allyl, alkaryl, arylalkyl groups, optionally comprising one or more heteroatoms.

Compositions useful in propylene polymerization catalysts, and in particular solid, hydrocarbon-insoluble, catalyst compositions containing magnesium, titanium, and halogen and further comprising a modifier compound with structure (1):

##STR00001## wherein Q1 is an oxygen containing group selected from CH.sub.2OR.sup.1, C(O)R.sup.1 and C(O)OR.sup.1 and Q2 is selected from R.sup.2 and OR.sup.2; R.sup.1 to R.sup.5 each being independently selected from H, alkyl, aryl, allyl, alkaryl, arylalkyl groups, optionally comprising one or more heteroatoms.

A method for altering the melt flow ratio (MFR) of ethylene copolymers made in a gas phase reactor using a supported Ziegler-Natta catalyst treated with a catalyst modifier. The method involves changing the amount of the catalyst modifier added to the supported Ziegler-Natta polymerization catalyst to effect changes in the MFR of the resulting polymer.

A method for altering the melt flow ratio (MFR) of ethylene copolymers made in a gas phase reactor using a supported Ziegler-Natta catalyst treated with a catalyst modifier. The method involves changing the amount of the catalyst modifier added to the supported Ziegler-Natta polymerization catalyst to effect changes in the MFR of the resulting polymer.

The present invention relates to a solid Ziegler-Natta catalyst component for use in olefin polymerization. The catalyst component comprises magnesium, titanium, halide, one or more dicylopentyldialkoxysilane compounds, one or more dialkylaminotrialkoxysilane compounds, and one or more internal electron donors comprising urea, phthalate and 1,3-diether. The catalyst components, according to present invention, are able to produce polypropylene polymers having high isotacticity with high melt flow rate.