C08F2420/04

Polyethylene homopolymer compositions having good barrier properties

A polyethylene homopolymer composition comprises: a first ethylene homopolymer having a density, d.sup.1 of from 0.943 to 0.975 g/cm.sup.3, a melt index, I.sub.2.sup.1 of from 0.01 to 10 g/10 min, and a molecular weight distribution, Mw/Mn of less than 3.0; and a second ethylene homopolymer having a density, d.sup.2 of from 0.950 to 0.985 g/cm.sup.3, a melt index, I.sub.2.sup.2 of at least 500 g/10 min, and a molecular weight distribution, M.sub.w/M.sub.n of less than 3.0; wherein the ratio of the melt index, I.sub.2.sup.2 of the second ethylene homopolymer to the melt index, I.sub.2.sup.1 of the first ethylene homopolymer is at least 50. The polyethylene homopolymer compositions which may be nucleated have a weight average molecular weight, M.sub.w of ?75,000, a high load melt index, I.sub.21 of at least 200 g/10 min, a molecular weight distribution, M.sub.w/M.sub.n of from 4.0 to 12.0 and may be usefully employed in molding applications, such as, for example, in compression molded closures.

ETHYLENE POLYMER AND PREPARATION METHOD THEREFOR

The present invention relates to an ethylene polymer and a process for preparing the same, wherein the ethylene polymer has an average particle size of 50-3000 ?m, a bulk density of 0.28-0.55 g/cm.sup.3, a true density of 0.930-0.980 g/cm.sup.3, a melt index at a load of 2.16 Kg at 190? C. of 0.01-2500 g/10 min, a crystallinity of 30-90%, a melting point of 105-147? C., a comonomer molar insertion rate of 0.01-5 mol %, a weight-average molecular weight of 2?10.sup.4 g/mol-40?10.sup.4 g/mol, and a molecular weight distribution of 1.8-10. In the preparation process, raw materials containing ethylene, hydrogen gas and a comonomer are subjected to a tank-type slurry polymerization with an alkane solvent having a boiling point of 5-55? C. or a mixed alkane solvent having a saturated vapor pressure of 20-150 KPa at 20? C. as the polymerization solvent in the presence of a polyethylene catalytic system, at the molar ratio of hydrogen gas to ethylene of 0.01-20:1, preferably 0.015-10:1, at the molar ratio of hydrogen gas to the comonomer of 0.1-30:1, preferably 0.15-25:1 to prepare the ethylene polymer.

Catalyst systems containing low valent titanium-aluminum complexes and polymers produced therefrom

Disclosed herein are methods for synthesizing low valence, titanium-aluminum complexes from half-metallocene titanium compounds and alkylaluminum compounds. The titanium-aluminum complexes can be used as components in catalyst systems for the polymerization of olefins.

DILUTION INDEX

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.

THERMALLY TUNABLE PHOSPHINIMINE CATALYSTS

A new phosphinimine polymerization catalyst exhibits restricted rotation about a carbon-phosphorous bond. The restricted rotation is demonstrated using variable temperature .sup.1H NMR. Ethylene copolymers made using the catalysts have microstructures which are dependent on the temperature at which polymerization takes place.

Catalyst modification to control polymer architecture

By controlling the ratio of catalyst components or the type of activator the homogeneity of a polymer produced using a single site catalyst may be improved.

Catalyst modification to control polymer architecture

By controlling the ratio of catalyst components or the type of activator the homogeneity of a polymer produced using a single site catalyst may be improved.

Ethylene/1-butene copolymers with enhanced resin processability

Ethylene/1-butene copolymers made with a single site catalyst system have high melt strength and good processability.

Dual Catalyst System for Producing LLDPE Copolymers with Improved Processability

Disclosed herein are ethylene-based polymers generally characterized by a density from 0.89 to 0.93 g/cm.sup.3, a ratio of Mw/Mn from 3 to 6.5, a Mz from 200,000 to 650,000 g/mol, a CY-a parameter at 190 C. from 0.2 to 0.4, and a reverse short chain branching distribution. The ATREF profile of these polymers can have a high temperature peak from 92 to 102 C., and a low temperature peak from 18 to 36 C. less than that of the high temperature peak. These polymers can have comparable physical properties to that of a metallocene-catalyzed LLDPE, but with improved processability, shear thinning, and melt strength, and can be used in blown film and other end-use applications.

Dual catalyst system for producing LLDPE copolymers with improved processability

Disclosed herein are ethylene-based polymers generally characterized by a density from 0.89 to 0.93 g/cm.sup.3, a ratio of Mw/Mn from 3 to 6.5, a Mz from 200,000 to 650,000 g/mol, a CY-a parameter at 190 C. from 0.2 to 0.4, and a reverse short chain branching distribution. The ATREF profile of these polymers can have a high temperature peak from 92 to 102 C., and a low temperature peak from 18 to 36 C. less than that of the high temperature peak. These polymers can have comparable physical properties to that of a metallocene-catalyzed LLDPE, but with improved processability, shear thinning, and melt strength, and can be used in blown film and other end-use applications.