C08F2420/00

High porosity fluorided silica-coated alumina activator-supports and uses thereof in metallocene-based catalyst systems for olefin polymerization

Fluorided silica-coated alumina activator-supports have a bulk density from 0.15 to g/mL, a total pore volume from 0.85 to 2 mL/g, a BET surface area from 200 to 500 m.sup.2/g, an average pore diameter from 10 to 25 nm, and from 80 to 99% of pore volume in pores with diameters of greater than 6 nm. Methods of making the fluorided silica-coated alumina activator-supports and using the fluorided silica-coated aluminas in catalyst compositions and olefin polymerization processes also are described. Representative ethylene-based polymers produced using the compositions and processes have a melt index of 0.1 to 10 g/10 min and a density of 0.91 to 0.96 g/cm.sup.3, and contain from 70 to 270 ppm solid oxide and from 2 to 18 ppm fluorine.

Bimodal polyethylene copolymers

Ethylene-based polymers are characterized by a density from 0.92 to 0.955 g/cm.sup.3, a HLMI of less than 35 g/10 min, and a ratio of a number of short chain branches (SCBs) per 1000 total carbon atoms at Mz to a number of SCBs per 1000 total carbon atoms at Mn in a range from 11.5 to 22. These polymers can have a higher molecular weight (HMW) component and a lower molecular weight (LMW) component, in which a ratio of a number of SCBs per 1000 total carbon atoms at Mn of the HMW component to a number of SCBs per 1000 total carbon atoms at Mn of the LMW component is in a range from 10.5 to 22. These ethylene polymers can be produced using a dual catalyst system containing an unbridged metallocene compound with an indenyl group having at least one halogen-substituted hydrocarbyl substituent with at least two halogen atoms, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group.

Methods for determining transition metal compound concentrations in multicomponent liquid systems

Methods for simultaneously determining the concentrations of transition metal compounds in solutions containing two or more transition metal compounds are described. Polymerization reactor systems providing real-time monitoring and control of the concentrations of the transition metal components of a multicomponent catalyst system are disclosed, as well as methods for operating such polymerization reactor systems.

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.

Process for the preparation of polyethylenes

The present invention relates to a process for the production of a polyethylene by polymerisation of a reaction mixture comprising ethylene in the presence a catalyst system and an antistatic agent according to formula I: (I) wherein R1, R2 and R3 stand for a moiety according to formula II or a hydrocarbon moiety having 1 to 20 carbon atoms (II) wherein each of R4, R5 and R6 may be the same or different, and wherein each of R4, R5 and R6 is a hydrocarbon moiety having 1 to 10 carbon atoms, and wherein at least one of R1, R2 and R3 is a moiety according to formula II. Such process allows for the reduction of sheeting in the polymerisation reactor without compromising the polymerisation reaction kinetics. ##STR00001##

METHOD TO PREPARE ETHYLENE COPOLYMERS

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.

Methods for Determining Transition Metal Compound Concentrations in Multicomponent Liquid Systems
20190299183 · 2019-10-03 ·

Methods for simultaneously determining the concentrations of transition metal compounds in solutions containing two or more transition metal compounds are described. Polymerization reactor systems providing real-time monitoring and control of the concentrations of the transition metal components of a multicomponent catalyst system are disclosed, as well as methods for operating such polymerization reactor systems.

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.

PROCESS FOR THE PREPARATION OF POLYMERIZED POLYETHYLENE WAX

The present invention relates to a process for the preparation of a polyethylene wax, the process comprising the steps of providing a catalyst solution, wherein the catalyst solution comprises at least one activating compound, an alkylaluminoxane and a me-tallocene complex, wherein the molar ratio of the activating compound to aluminum comprised in the alkylaluminoxane is from 0.0005 to 0.20; and polymerizing ethylene, by contacting the ethylene and the catalyst solution.

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.