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.

The present disclosure relates to asymmetric ansa-metallocene catalyst compounds that include at least one indenyl ligand substituted at the 3-position with a C.sub.3-C.sub.40 -branched alkyl, such as 1-methylethyl, 1-methylpropyl, 1-methylbutyl, 1-ethylbutyl, 1,3-dimethylbutyl, 1-methyl-1-ethylbutyl, 1,1-diethylbutyl, 1-propylpentyl, and the like. Catalyst systems prepared with the catalyst compounds, polymerization methods using such catalyst systems, and polyolefins made using the polymerization methods are also described.

The present disclosure provides bridged metallocene catalyst compounds including at least two SiSi bridges, catalyst systems including such compounds, and uses thereof. Catalyst compounds of the present disclosure can be hafnium-containing compounds having one or more cyclopentadiene ligand(s) substituted with one or more silyl neopentyl groups and linked with at least two SiSi-containing bridges. In another class of embodiments, the present disclosure is directed to polymerization processes to produce polyolefin polymers from catalyst systems including one or more olefin polymerization catalysts, at least one activator, and an optional support.

Disclosed herein is a catalyst compound represented by Formula (I) or Formula (II): ##STR00001##
M is a group 4 metal. Each of R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, and R.sup.9 is independently hydrogen, or a C1-C50 substituted or unsubstituted hydrocarbyl, halocarbyl, silylcarbyl, alkoxyl, siloxyl, or one or more of R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.5 and R.sup.6, R.sup.6 and R.sup.7, and R.sup.7 and R.sup.8 are joined to form cyclic a saturated or unsaturated ring. Each X is independently a halide or C1-C50 substituted or unsubstituted hydrocarbyl, hydride, amide, alkoxide, sulfide, phosphide, halide, or a combination thereof, or two Xs are joined together to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene. Also disclosed is a method for using the catalyst compound in a catalyst system to produce polyolefin polymers.

A method for forming polar-functionalized polyolefins may comprise contacting an unsubstituted -olefin monomer and an amino-olefin monomer of formula H.sub.2CCH(CH.sub.2).sub.n(CHR).sub.mNR.sub.2, wherein R is H or an unsubstituted linear or branched alkyl group having from 1 to 10 carbons, each R is an independently selected unsubstituted linear or branched alkyl group having from 1 to 10 carbons, m is an integer from 1 to 11, and n is an integer from 1 to 11, in the presence of a rare earth catalyst and a cocatalyst under conditions to induce a heteropolymerization reaction between the unsubstituted oc-olefin and amino-olefin monomers to provide a polar-functionalized poly olefin.

The present invention relates to a catalyst composition for synthesizing an olefin copolymer, including a first metallocene catalyst, a second metallocene catalyst, and a third metallocene catalyst, each having a specific structure, and a method for preparing an olefin copolymer using the catalyst composition for synthesizing an olefin copolymer.

Catalyst systems and methods for making and using the same are described. A method includes selecting a catalyst blend using a blend polydispersity index (bPDI) map. The polydispersity map is generated by generating a number of polymers for at least two catalysts. Each polymer is generated at a different hydrogen to ethylene ratio. At least one catalyst generates a higher molecular weight polymer and another catalyst generates a lower molecular weight polymer. A molecular weight for each polymer is measured. The relationship between the molecular weight of the polymers generated by each of the catalysts and the ratio of hydrogen to ethylene is determined. A family of bPDI curves for polymers that would be made using a number of ratios of a blend of the at least two catalysts for each of a number of ratios of hydrogen to ethylene. A ratio for the catalyst blend of the catalysts that generates a polymer having a bPDI that matches a polymer fabrication process is selected, and the product specific polyolefin is made using the catalyst blend.

Novel polyethylene copolymers having a relatively high comonomer partitioning tendency are disclosed as are methods for their preparation. The comonomer partitioning tendency is the tendency for a copolymer to have comonomer in the higher molecular weight chains. Novel metrics for describing the comonomer partitioning tendency are also disclosed.

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.

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.