C08F2500/11

Dual catalyst system for producing polyethylene with long chain branching for blow molding applications

Ethylene-based polymers are characterized by a melt index less than 1 g/10 min, a density from 0.94 to 0.965 g/cm.sup.3, a Mw from 100,000 to 250,000 g/mol, a relaxation time from 0.5 to 3 sec, and an average number of long chain branches (LCBs) per 1,000,000 total carbon atoms in a molecular weight range of 300,000 to 900,000 g/mol that is greater than that in a molecular weight range of 1,000,000 to 2,000,000 g/mol, or an average number of LCBs per 1,000,000 total carbon atoms in a molecular weight range of 1,000,000 to 2,000,000 g/mol of less than or equal to about 5 and a maximum ratio of η.sub.E/3η at an extensional rate of 0.1 sec.sup.−1 from 1.2 to 10. These polymers have substantially no long chain branching in the high molecular weight fraction of the polymer, but instead have significant long chain branching in a lower molecular weight fraction, such that polymer melt strength and parison stability are maintained for the fabrication of blow molded products and other articles of manufacture. These ethylene polymers can be produced using a dual catalyst system containing a single or two atom bridged metallocene compound with two indenyl groups, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group.

Flexible crosslinked cable insulation and methods for making flexible crosslinked cable insulation

Crosslinkable polymeric compositions comprising (a) 10 to 99 weight percent of an ethylene-based interpolymer having the following properties: (i) a density of 0.93 g/cm.sup.3 or less, (ii) a high-shear viscosity (V100) at 190° C. and 10% strain of 1,200 Pa-s or less, and (iii) a shear thinning ratio (V0.1/V100) at 190° C. and 10% strain of at least 8; and (b) 0 to less than 10 weight percent of a filler, where the ethylene-based interpolymer is not prepared in a high-pressure reactor. Such crosslinkable polymeric compositions may be employed as insulation layers in flexible power cables.

Flexible crosslinked cable insulation and methods for making flexible crosslinked cable insulation

Crosslinkable polymeric compositions comprising (a) 10 to 99 weight percent of an ethylene-based interpolymer having the following properties: (i) a density of 0.93 g/cm.sup.3 or less, (ii) a high-shear viscosity (V100) at 190° C. and 10% strain of 1,200 Pa-s or less, and (iii) a shear thinning ratio (V0.1/V100) at 190° C. and 10% strain of at least 8; and (b) 0 to less than 10 weight percent of a filler, where the ethylene-based interpolymer is not prepared in a high-pressure reactor. Such crosslinkable polymeric compositions may be employed as insulation layers in flexible power cables.

Polyethylenes And Processes For Producing Polyethylenes

The present disclosure provides processes for producing polyethylene resins. In at least one embodiment, a polyethylene has: a density of from about 0.91 g/cm.sup.3 to about 0.94 g/cm.sup.3; a value of Mz of about 1,500,000 g/mol or greater; and a ratio of Mz to Mw of about 7 or greater. A process includes introducing a first feed stream having ethylene monomer and a first free radical initiator to a first inlet of a first reaction zone, where the first reaction zone has a first inlet temperature. The process further includes introducing a second feed stream having ethylene monomer and a second free radical initiator to a second inlet of a second reaction zone, where the second reaction zone has a second inlet temperature that is the same or different than the first inlet temperature.

Polyethylenes And Processes For Producing Polyethylenes

The present disclosure provides processes for producing polyethylene resins. In at least one embodiment, a polyethylene has: a density of from about 0.91 g/cm.sup.3 to about 0.94 g/cm.sup.3; a value of Mz of about 1,500,000 g/mol or greater; and a ratio of Mz to Mw of about 7 or greater. A process includes introducing a first feed stream having ethylene monomer and a first free radical initiator to a first inlet of a first reaction zone, where the first reaction zone has a first inlet temperature. The process further includes introducing a second feed stream having ethylene monomer and a second free radical initiator to a second inlet of a second reaction zone, where the second reaction zone has a second inlet temperature that is the same or different than the first inlet temperature.

Producing polyolefin products

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.

Solution polymerization process

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.

Solution polymerization process

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.

METHOD OF PRODUCING POLYETHYLENE AND POLYETHYLENE THEREOF

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.

Polypropylene for films and the films therefrom

A process to prepare a polypropylene, and the polypropylene and films therefrom, comprising combining a high melt strength polypropylene comprising at least 50 mol % propylene, and having a molecular weight distribution (Mw/Mn) greater than 6, a branching index (g′.sub.vis) of at least 0.95, and a melt strength of at least 20 cN determined using an extensional rheometer at 190° C., and within the range from 20 to 1000 ppm of a long half-life organic peroxide, and isolating the polypropylene, wherein the polypropylene thus formed has a molecular weight distribution (Mw/Mn) within a range of from 7 to 22, a z-average molecular weight of less than 1,600,000 g/mole, a branching index (g′.sub.vis) of at least 0.95; and a melt strength less than 20 cN.