Catalyst systems and methods for making and using the same. A method of methylating a catalyst composition while substantially normalizing the entiomeric distribution is provided. The method includes slurrying the organometallic compound in dimethoxyethane (DME), and adding a solution of RMgBr in DME, wherein R is a methyl group or a benzyl group, and wherein the RMgBr is greater than about 2.3 equivalents relative to the organometallic compound. After the addition of the RMgBr, the slurry is mixed for at least about four hours. An alkylated organometallic is isolated, wherein the methylated species has a meso/rac ratio that is between about 0.9 and about 1.2.

This invention relates to a supported catalyst system comprising: (i) at least one first catalyst component comprising a group 4 metallocycle containing metallocene complex; (ii) at least one second catalyst component comprising a 2,6-bis(imino)pyridyl iron complex; (iii) activator; and (iv) support. The catalyst system may be used for preparing polyolefins, such a bimodal polyethylene, typically in a gas phase polymerization.

Improved preparation process for silica supported catalyst systems, which comprise a specific class of metallocene complexes in combination with a boron containing cocatalyst and an aluminoxane cocatalyst and use of the new, improved catalyst system.

Improved preparation process for supported catalyst systems, which comprise a specific class of metallocene complexes in combination with a boron containing cocatalyst and an aluminoxane cocatalyst and use of the new, improved catalyst system.

New, improved silica supported catalyst system, which comprises a specific class of metallocene complexes in combination with a boron containing cocatalyst and an aluminoxane cocatalyst, its use for producing propylene homopolymers, propylene copolymers, especially with ethylene, as well as heterophasic propylene copolymers, preferably in a multistep process including a gas phase polymerization step.

Catalyst systems and methods for making and using the same. A method of methylating a catalyst composition while substantially normalizing the entiomeric distribution is provided. The method includes slurrying the organometallic compound in dimethoxyethane (DME), and adding a solution of RMgBr in DME, wherein R is a methyl group or a benzyl group, and wherein the RMgBr is greater than about 2.3 equivalents relative to the organometallic compound. After the addition of the RMgBr, the slurry is mixed for at least about four hours. An alkylated organometallic is isolated, wherein the methylated species has a meso/rac ratio that is between about 0.9 and about 1.2.

A system and method of producing polyethylene, including: polymerizing ethylene in presence of a catalyst system in a reactor to form polyethylene, wherein the catalyst system includes a first catalyst and a second catalyst; and adjusting reactor conditions and an amount of the second catalyst fed to the reactor to control melt index (MI), density, and melt flow ratio (MFR) of the polyethylene.

A system and method of producing polyethylene, including: polymerizing ethylene in presence of a catalyst system in a reactor to form polyethylene, wherein the catalyst system includes a first catalyst and a second catalyst; and adjusting reactor conditions and an amount of the second catalyst fed to the reactor to control melt index (MI), density, and melt flow ratio (MFR) of the polyethylene.

Metallocene complexes represented by the structure below are useful for alpha olefin oligomerization in the presence of an activator to generate polyalphaolefins having a high percentage of vinylidene termination and relatively low Mn values.

##STR00001##

M is a group 4 transition metal. A is a bridging group having one bridging atom extending between a first indenyl ring and a second indenyl ring. Each X is independently an anionic ligand, or two Xs are joined and bound to M to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand. R.sup.1, R.sup.1′, R.sup.3, R.sup.3′, R.sup.4, R.sup.4′, R.sup.7 and R.sup.7′ are hydrogen. R.sup.5, R.sup.5′, R.sup.6, and R.sup.6′ are independently a C.sub.1-C.sub.10, optionally substituted, hydrocarbyl group, or R.sup.5 and R.sup.6 and/or R.sup.5′ and R.sup.6′ are bonded together to form an optionally substituted hydrocarbyl ring structure.

Catalyst systems and methods for making and using the same. A method of polymerizing olefins to produce a polyolefin polymer with a multimodal composition distribution, includes contacting ethylene and a comonomer with a catalyst system. The catalyst system includes a first catalyst compound and a second catalyst compound that are co-supported to form a commonly supported catalyst system. The first catalyst compound includes a compound with the general formula (C.sub.5H.sub.aR.sup.1.sub.b)(C.sub.5H.sub.cR.sup.2.sub.d)HfX.sub.2. The second catalyst compound includes at least one of the following general formulas:

##STR00001##

In both catalyst systems, the R groups can be independently selected from any number of substituents, including, for example, H, a hydrocarbyl group, a substituted hydrocarbyl group, or a heteroatom group, among others.