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.

Methods for treating solid metallocene compounds that are exposed to air are disclosed. These methods include a step of contacting the exposed solid metallocene compound with a purging gas stream containing an inert gas, and optionally, subjecting the exposed solid metallocene compound to a sub-atmospheric pressure.

Disclosed herein are ethylene-based polymers produced using dual metallocene catalyst systems. These polymers have low densities, high molecular weights, and broad molecular weight distributions, as well as having the majority of the long chain branches in the lower molecular weight component of the polymer, and the majority of the short chain branches in the higher molecular weight component of the polymer. Films produced from these polymers have improved impact and puncture resistance.

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.

Sulfated bentonite compositions are characterized by a total pore volume from 0.4 to 1 mL/g, a total BET surface area from 200 to 400 m.sup.2/g, and an average pore diameter from 55 to 100 Angstroms. The sulfated bentonite compositions also can be characterized by a d50 average particle size in a range from 15 to 50 ?m and a ratio of d90/d10 from 3 to 15. The sulfated bentonite compositions can contain a sulfated bentonite and from 10 to 90 wt. % of colloidal particles, or the sulfated bentonite compositions can contain a sulfated bentonite and from 0.2 to 10 mmol/g of zinc and/or phosphorus. These compositions can be utilized in metallocene catalyst systems to produce ethylene based polymers.

A catalytic system based at least on a preformation conjugated diene monomer, on an organometallic compound as cocatalyst and on a metallocene of formula {P(Cp.sup.1)(Cp.sup.2)Y} is provided. In the formula, Y denotes a group comprising a metal atom which is a rare earth metal, Cp.sup.1 and Cp.sup.2, which are identical or different, are selected from the group consisting of fluorenyl groups, cyclopentadienyl groups and indenyl groups, the groups being substituted or unsubstituted, and P is a group bridging the two Cp.sup.1 and Cp.sup.2 groups and comprising a silicon or carbon atom. Such a catalytic system exhibits an improved stability of the catalytic activity over time, in particular on storage.

Disclosed herein are ethylene-based polymers produced using dual metallocene catalyst systems. These polymers have low densities, high molecular weights, and broad molecular weight distributions, as well as having the majority of the long chain branches in the lower molecular weight component of the polymer, and the majority of the short chain branches in the higher molecular weight component of the polymer. Films produced from these polymers have improved impact and puncture resistance.

A continuous solution polymerization process is disclosed wherein at least two catalyst formulations are employed. A first homogeneous catalyst formulation is employed in a first reactor to produce a first ethylene interpolymer and a first heterogeneous catalyst formulation is employed in a second reactor to produce a second ethylene interpolymer. Optionally a third ethylene interpolymer is formed in a third reactor. The resulting ethylene interpolymer products possess desirable properties in a variety of end use applications, for example in film applications. A means for increasing the molecular weight of the first ethylene interpolymer is disclosed and/or a means for increasing the temperature of the first reactor, relative to a third homogeneous catalyst formulation. A means for reducing the (-olefin/ethylene) weight ratio in the first reactor is disclosed and/or reducing the density of the first ethylene interpolymer, relative to a third homogeneous catalyst formulation.

This disclosure relates to ethylene interpolymer compositions. Specifically, ethylene interpolymer products having: a Dilution Index (Y.sub.d) greater than 0; total catalytic metal 3.0 ppm; 0.03 terminal vinyl unsaturations per 100 carbon atoms, and; optionally a Dimensionless Modulus (X.sub.d) greater than 0. The disclosed ethylene interpolymer products have a melt index from about 0.3 to about 500 dg/minute, a density from about 0.869 to about 0.975 g/cm.sup.3, a polydispersity (M.sub.w/M.sub.n) from about 2 to about 25 and a CDBI.sub.50 from about 20% to about 97%. Further, the ethylene interpolymer products are a blend of at least two ethylene interpolymers; where one ethylene interpolymer is produced with a single-site catalyst formulation and at least one ethylene interpolymer is produced with a heterogeneous catalyst formulation.

This disclosure relates to ethylene interpolymer compositions. Specifically, ethylene interpolymer products having: a Dilution Index (Y.sub.d) greater than 0; total catalytic metal 3.0 ppm; 0.03 terminal vinyl unsaturations per 100 carbon atoms, and; optionally a Dimensionless Modulus (X.sub.d) greater than 0. The disclosed ethylene interpolymer products have a melt index from about 0.3 to about 500 dg/minute, a density from about 0.869 to about 0.975 g/cm.sup.3, a polydispersity (M.sub.w/M.sub.n) from about 2 to about 25 and a CDBI.sub.50 from about 20% to about 97%. Further, the ethylene interpolymer products are a blend of at least two ethylene interpolymers; where one ethylene interpolymer is produced with a single-site catalyst formulation and at least one ethylene interpolymer is produced with a heterogeneous catalyst formulation.