Provided are various bimodal polyethylene, including but not limited to a bimodal polyethylene for a pipe having a density of from 0.9340 to 0.9470 gram/cubic centimeters (g/ccm), a melt index (12) of from 0.1 to 0.7 gram/10 minute, a melt flow ratio (121/12) of from 20 to 90. The bimodal polyethylene includes a high molecular weight polyethylene component and a low molecular weight polyethylene component which are a reaction product of a polymerization process performed in a single reactor and that employs a bimodal polymerization catalyst system. The bimodal polymerization catalyst system includes a bimodal catalyst system of bis(2-pentamethylphenylamido)ethyl)amine Zirconium dibenzyl and either (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)Zirconium dichloride or (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium dimethyl in a 3.0:1 molar ratio; and a trim catalyst of (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)Zirconium dichloridedimethyl in heptane added to adjust melt.

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 disclosure relates to a continuous solution polymerization process wherein production rate is increased. Process solvent, ethylene, optional comonomers, optional hydrogen and a single site catalyst formulation are injected into a first reactor forming a first ethylene interpolymer. Process solvent, ethylene, optional comonomers, optional hydrogen and a heterogeneous catalyst formulation are injected into a second reactor forming a second ethylene interpolymer. The first and second reactors may be configured in series or parallel modes of operation. Optionally, a third ethylene interpolymer is formed in an optional third reactor, wherein an optional heterogeneous catalyst formulation may be employed. In a solution phase, the first, second and optional third ethylene interpolymers are combined, the catalyst is deactivated, the solution is passivated and following a phase separation process an ethylene interpolymer product is recovered.

This disclosure relates to a continuous solution polymerization process wherein production rate is increased. Process solvent, ethylene, optional comonomers, optional hydrogen and a single site catalyst formulation are injected into a first reactor forming a first ethylene interpolymer. Process solvent, ethylene, optional comonomers, optional hydrogen and a heterogeneous catalyst formulation are injected into a second reactor forming a second ethylene interpolymer. The first and second reactors may be configured in series or parallel modes of operation. Optionally, a third ethylene interpolymer is formed in an optional third reactor, wherein an optional heterogeneous catalyst formulation may be employed. In a solution phase, the first, second and optional third ethylene interpolymers are combined, the catalyst is deactivated, the solution is passivated and following a phase separation process an ethylene interpolymer product is recovered.

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.

The invention relates to a solid catalyst system comprising a chromium compound, a metal compound, an aluminium compound and a silicon oxide support, wherein the silicon oxide support has an average particle diameter in the range between ≥20 and ≤50 μm, a pore volume in the range between ≥1.7 ml/g and ≤3 ml/g, and a surface area in the range between ≥400 m.sup.2/g and ≤800 m.sup.2/g, and wherein the aluminium alkoxide compound has the formula

R.sub.1—Al—OR.sub.2

wherein R.sub.1 is selected from (C.sub.1-C.sub.8) alkyl groups and OR.sub.2 is selected from (C.sub.1-C.sub.8) alkoxyl groups.

The invention relates to a solid catalyst system comprising a chromium compound, a metal compound, an aluminium compound and a silicon oxide support, wherein the silicon oxide support has an average particle diameter in the range between ≥20 and ≤50 μm, a pore volume in the range between ≥1.7 ml/g and ≤3 ml/g, and a surface area in the range between ≥400 m.sup.2/g and ≤800 m.sup.2/g, and wherein the aluminium alkoxide compound has the formula

R.sub.1—Al—OR.sub.2

wherein R.sub.1 is selected from (C.sub.1-C.sub.8) alkyl groups and OR.sub.2 is selected from (C.sub.1-C.sub.8) alkoxyl groups.

In various embodiments, a polyethylene formulation has a density of greater than 0.940 g/cm.sup.3 when measured according to ASTM D792, and a high load melt index (I.sub.21) of 1.0 g/10 min to 10.0 g/10 min when measured according to ASTM D1238 at 190° C. and a 21.6 kg load. Moreover, the polyethylene formulation has a peak molecular weight (M.sub.p(GPC)) of less than 50,000 g/mol, a number average molecular weight (M.sub.n(GPC)) of less than 30,000 g/mol, and a weight fraction (w1) of molecular weight (MW) less than 10,000 g/mol of less than or equal to 10.5 wt %, as determined by Gel Permeation Chromatography (GPC). Articles made from the polyethylene formulation, such as articles made by blow molding processes are also provided.

In various embodiments, a polyethylene formulation has a density of greater than 0.940 g/cm.sup.3 when measured according to ASTM D792, and a high load melt index (I.sub.21) of 1.0 g/10 min to 10.0 g/10 min when measured according to ASTM D1238 at 190° C. and a 21.6 kg load. Moreover, the polyethylene formulation has a peak molecular weight (M.sub.p(GPC)) of less than 50,000 g/mol, a number average molecular weight (M.sub.n(GPC)) of less than 30,000 g/mol, and a weight fraction (w1) of molecular weight (MW) less than 10,000 g/mol of less than or equal to 10.5 wt %, as determined by Gel Permeation Chromatography (GPC). Articles made from the polyethylene formulation, such as articles made by blow molding processes are also provided.

This disclosure relates to a continuous solution polymerization process where ethylene interpolymer products having an improved color index; for example, products having higher whiteness (Whiteness Index (WI)) and lower yellowness (Yellowness Index (YI)). Product color was improved by adjusting selected solution polymerization reaction conditions. The disclosed ethylene interpolymer products have improved color relative to comparative polyethylene compositions.