Ethylene-based polymers having a density of 0.952 to 0.968 g/cm.sup.3, a ratio of HLMI/MI from 185 to 550, an IB parameter from 1.46 to 1.80, a tan δ at 0.1 sec.sup.−1 from 1.05 to 1.75 degrees, and a slope of a plot of viscosity versus shear rate at 100 sec.sup.−1 from 0.18 to 0.28 are described, with low melt flow versions having a HLMI from 10 to 30 g/10 min and a Mw from 250,000 to 450,000 g/mol, and high melt flow versions having a HLMI from 30 to 55 g/10 min and a Mw from 200,000 to 300,000 g/mol. These polymers have the processability of chromium-based resins, but with improved stress crack resistance and topload strength for bottles and other blow molded products.

A diblock polymer composed of a first block and a second block is provided. The first block is a statistical copolymer comprising units of a 1,3-diene and more than 50 mol % of ethylene units. The second block is a polyethylene with a melting point above 90° C. and a number-average molar mass greater than or equal to 2000 g/mol and less than or equal to 10 000 g/mol. Such a diblock polymer has improved rheology compared to a statistical copolymer of the same microstructure and of the same macrostructure as the first block of the diblock polymer.

Ethylene-based polymers having a density of 0.952 to 0.968 g/cm3. a ratio of HLMI/MI from 185 to 550. an IB parameter from 1.46 to 1.80, a tan δ at 0.1 sec.sup.-1 from 1.05 to 1.75 degrees, and a slope of a plot of viscosity versus shear rate at 100 sec.sup.-1 from 0.18 to 0.28 are described, with low melt flow versions having a HLMI from 10 to 30 g/10 min and a Mw from 250,000 to 450,000 g/mol, and high melt flow versions having a HLMI from 30 to 55 g/10 min and a Mw from 200,000 to 300,000 g/mol. These polymers have the processability of chromium-based resins, but with improved stress crack resistance and topload strength for bottles and other blow molded products.

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 .Math.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.

The purpose of the present invention is to provide a method for efficiently producing an olefin (co)polymer containing a constituent unit derived from 1-butene, the (co)polymer having a molecular weight that is sufficiently high even for high temperature conditions that are beneficial for industrial production methods. This purpose can be achieved by means of a method for producing an olefin (co)polymer containing a constituent unit derived from 1-butene, wherein at least 1-butene and, if necessary, an α-olefin having 2 or more carbon atoms (excluding 1-butene) and other monomers are (co)polymerized in the presence of an olefin polymerization catalyst that contains (A) a crosslinked metallocene compound represented by general formula [I] and (B) at least one type of compound selected from among (b-1) an organic aluminum oxy compound, (b-2) a compound that forms an ion pair upon a reaction with the crosslinked metallocene compound (A), and (b-3) an organic aluminum compound, at a polymerization temperature of 55-200° C. and a polymerization pressure of 0.1-5.0 MPaG.

The invention relates to a process for the preparation of a particulate ultra high molecular weight polyethylene (UH-MWPE), comprising the steps of preparing a magnesium containing carrier, loading the carrier with a organometallic compound forming a supported catalyst and contacting the supported catalyst with at least ethylene under polymerization conditions, wherein the organometallic compound is of the formula R.sup.3.sub.3P═N—TiCpX.sub.n.

A catalyst system comprising a) a metal complex of the formula CyLMZ.sub.p, wherein M is a group 4 metal Z is an anionic ligand, p is number of 1 to 2, preferably 2 Cy is a cyclopentadienyl-type ligand and, L is a ligand of the formula ##STR00001## wherein each A is independently selected from the group consisting of nitrogen and phosphorus and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently selected from the group consisting of hydrogen, unsubstituted or substituted hydrocarbyl, unsubstituted or substituted silyl and unsubstituted or substituted germyl residues, and b) a boron containing activator, characterized in that the molar ratio of the boron of the activator to M of the metal complex is greater than 2.5.

The present invention provides a polyolefin polymer having a bimodal composition with a reduced higher molecular weight component prepared using a self-supported phosphinimine single site catalyst. The catalyst is prepared by precipitating an emulsion of the activated catalyst from a perfluoroalkane continuous phase resulting in spherical catalyst particles having a diameter typically from 5 to 200 μm.

The present disclosure relates to dual catalyst systems and processes for use thereof. The present disclosure further provides a catalyst system that is a combination of at least two hafnium metallocene catalyst compounds. The catalyst systems may be used for olefin polymerization processes. The present disclosure further provides for polymers, which can be formed by processes and catalyst systems of the present disclosure.

Ethylene-based polymers having a density of 0.952 to 0.968 g/cm.sup.3, a ratio of HLMI/MI from 185 to 550, an IB parameter from 1.46 to 1.80, a tan δ at 0.1 sec.sup.−1 from 1.05 to 1.75 degrees, and a slope of a plot of viscosity versus shear rate at 100 sec.sup.−1 from 0.18 to 0.28 are described, with low melt flow versions having a HLMI from 10 to 30 g/10 min and a Mw from 250,000 to 450,000 g/mol, and high melt flow versions having a HLMI from 30 to 55 g/10 min and a Mw from 200,000 to 300,000 g/mol. These polymers have the processability of chromium-based resins, but with improved stress crack resistance and topload strength for bottles and other blow molded products.