Process for producing polyethylene polymers

Abstract

This disclosure relates to a method for polymerizing olefins, the method comprising optionally using at least one other α-olefin comonomer (preferably C) 4‑10 In the presence of α-olefin comonomers, preferably in a multi-stage polymerization configuration, ethylene is polymerized in the presence of a single-point polymerization catalyst to produce a polymer component for producing a polyethylene polymer or polyethylene copolymer, wherein the single-point polymerization catalyst comprises (i) a transition metal complex; (ii) a cocatalyst; and optionally (iii) a support; characterized in that: the product of (Weibull modulus) x (scale parameter) is equal to or greater than 40 MPa, and the ratio of (Weibull modulus) / (scale parameter) is equal to or less than 0.50 MPa. ‑1 The Weibull modulus and scale parameters are determined by Weibull analysis of the compressive strength of the catalyst particles. This disclosure further relates to a single-site polymerization catalyst comprising (i) a transition metal complex; (ii) a co-catalyst; and optionally (iii) a support, preferably a silica support; wherein the single-site polymerization catalyst is characterized by: a (Weibull modulus) x (scale parameter) product equal to or greater than 40 MPa, and a (Weibull modulus) / (scale parameter) ratio equal to or less than 0.50 MPa. ‑1 The Weibull modulus and dimensional parameters are determined by Weibull analysis of the compressive strength of the catalyst particles. This disclosure further relates to the use of unit-point polymerization catalysts in the preparation of polyethylene polymer components, polyethylene polymers, or polyethylene copolymers.

Description

[0001] public domain

[0002] This disclosure relates to methods for polymerizing olefins using a single-point polymerization catalyst to produce polyethylene polymers and copolymers. In particular, this disclosure relates to polymerizing olefins, especially in multi-stage polymerization configurations, to produce polyethylene polymers or copolymers having a narrow particle size distribution. This disclosure further relates to single-point polymerization catalysts.

[0003] Public background

[0004] Metallocene compounds are expensive materials compared to transition metal halides. Therefore, high-productivity polymerization catalysts are essential to maximize the output of the polymerization unit with minimal catalyst feed rate. If the catalyst productivity is too low, the method becomes economically infeasible.

[0005] Furthermore, when operating continuous polymerization methods (e.g., slurry or gas-phase methods, or a combination of both), it is important to avoid reactor fouling to minimize operational interruptions. A major cause of reactor fouling is the presence of very fine polymer particles that, due to electrostatic charge, tend to adhere to process surfaces and begin forming fouling on the reactor walls. Additionally, these particles often become trapped in gas-phase reactors, causing severe operational problems due to flocculent formation, or they can degrade the operation of peripheral equipment such as heat exchangers and compressors. In particular, if the catalyst used in the polymerization process consists of highly brittle particles, there is a risk that they break down too rapidly under polymerization conditions, resulting in fine catalyst or polymer powder due to uncontrolled initial particle fragmentation. Similarly, if the active components of the catalyst system are not uniformly distributed within the catalyst particles, there is a risk of creating spatial voids within the polymer particles, resulting in low bulk density polymer powder with an inherent risk of poor operability during polymerization.

[0006] Therefore, it would be highly beneficial to invent a metallocene catalyst that addresses the aforementioned limitations by combining high productivity in the polymerization process with optimal particle strength, thereby maintaining particle integrity throughout the polymerization process, preventing the formation of fine powder, and ensuring the production of polymer powders with high bulk density. Furthermore, it would be highly beneficial to invent a catalyst that possesses the aforementioned characteristics while having a uniformly distributed active material within the support, allowing for better control of the polymerization reaction and minimizing the formation of voids within the polymer particles, thereby producing polymer powders with high bulk density and improved operability.

[0007] US7754834B2 describes a method for forming polymer particles by continuously exposing olefin monomers to a catalyst present in a polymerization reactor. The polymer particles grow from the initial formation of “micro-clusters” at the active sites of the catalyst particles. As these micro-clusters develop, spatial voids are created between the growing primary polymer particles, eventually accounting for 10% to 25% of the final polymer particle volume. The presence of these spatial voids in the final polymer particles leads to a decrease in the polymer powder packing density. Low polymer powder packing density is generally associated with reduced production rates and operability problems (e.g., fine powder formation, poor material flowability, excessive residue), and is often related to quality and heat transfer limitations leading to agglomeration and clumping in the polymerization reactor.

[0008] To reduce flaking and / or agglomeration in polymerization reactors during operation, WO2018212852A1 discloses an olefin polymerization catalyst composition comprising particles with a pore size of 300 to [missing information]. Between and / or BET surface areas less than 700m² 2 The catalyst is prepared using a support with a pore size of 10% to 80% by volume, resulting in a more uniform distribution of the catalyst components throughout the support material. However, the distribution of the catalyst components within the support material can only be assessed by XPS, which evaluates the difference in aluminum content between the catalyst surface and interior. This is a qualitative method for assessing the actual distribution of the catalytically active components within the particles. No actual measurements of the aluminum distribution throughout the support have been reported to support this claim. The inventors also claim that using the catalyst of this invention leads to better control of polymerization kinetics, increased productivity, reduced formation of hollow polymer particles, and increased packing density of the polymer powder. However, only single-stage, laboratory-scale gas-phase polymerization experiments are provided to illustrate the features of the invention, and these features do not necessarily support the applicability of the invention in slurry reactors or in combinations of a series of slurry and gas-phase reactors in a multi-stage reactor setup.

[0009] Similarly, WO2016176135A1 suggests that poor operation of polymerization reactors is often due to the uneven distribution of catalyst active sites within the pore network of the support. The inventors claim that supported catalyst compositions with macropore volumes up to 1.23 mL / g exhibit good catalyst flowability and provide enhanced reactor operation. However, no polymerization data are published that can determine practical improvements in catalyst performance and operation during polymerization.

[0010] To reduce flocculenting and / or agglomeration in polymerization reactors during operation, WO2018175071A1 discloses olefin catalyst compositions prepared from supports with a porosity of 0.15 to 0.50 mL / g, resulting in increased deposition of catalyst components on and / or within the support material. The inventors claim that using such supports reduces flocculenting and / or agglomeration within the polymerization reactor during polymerization. However, no indication of improved catalyst activity or bulk density of the resulting polymer powder is provided.

[0011] US7244785B2 discloses that when using a solid polymer such as aluminoxane as an activator, the loading of the activator during catalyst preparation directly affects the catalyst productivity and the bulk density of the resulting polymer powder: the higher the loading of the aluminoxane activator during catalyst preparation, the higher the productivity and bulk density. However, the inventors report that due to the leaching of the active material into the reaction medium, when the aluminoxane loading is higher than 6.40 mol... 甲基铝氧烷 / g 二氧化硅 (6.40mol MAO / g silica At higher aluminoxane loadings, scaling begins to form on the walls of the polymerization reactor. This scaling prevents the inventors from fully utilizing the potential of their catalyst system to achieve maximum catalyst productivity through the high packing density of the polymer powder.

[0012] Public brief description

[0013] The purpose of this disclosure is to provide a method for ethylene polymerization, particularly a multi-stage polymerization method, typically comprising multiple reactors in series, and a specific catalyst system for the method, to mitigate the aforementioned disadvantages.

[0014] The object of this disclosure is achieved by a specific unit-point polymerization catalyst, the use of said catalyst, an olefin polymerization method, and a polyethylene (co)polymer, characterized as described in the independent claim. Preferred embodiments of this disclosure are disclosed in the dependent claims.

[0015] This disclosure is based on the idea of ​​providing catalyst particles capable of following a replication pattern to produce polymer particles with spherical morphology and narrow particle size distribution, and thus high packing density. This is crucial for the efficient operation of polymerization reactors and achieving higher productivity; this is true in both gas-phase and / or slurry circulation reactors. Therefore, it is essential to provide a metallocene catalyst system that helps control catalyst fragmentation during polymerization, allowing the grown catalyst / polymer particles to undergo smooth and controllable initial catalyst fragmentation, thereby producing polyethylene polymers with high polymer packing density. The means of controlling the catalyst particle fragmentation kinetics will lead to the optimal selection of polymerization process conditions, which in turn widens the process operating window and provides flexibility in operating the polymerization reactor, while reducing the risk of producing polymer particles with undesirable morphologies (e.g., small particle size, irregular shapes, etc.).

[0016] This is achieved by providing a single-point polymerization catalyst characterized by: a (Weibull modulus) x (scale parameter) product equal to or greater than 40 MPa, and a (Weibull modulus) / (scale parameter) ratio equal to or less than 0.50 MPa. -1 The Weibull modulus and scale parameters were determined by Weibull analysis of the compressive strength of the catalyst particles.

[0017] Publicly available detailed specifications

[0018] This disclosure provides a method for olefin polymerization, the method comprising optionally using at least one other α-olefin comonomer, preferably C 4-10 In the presence of α-olefin comonomers, preferably in a multi-stage polymerization configuration, ethylene is polymerized in the presence of a single-point polymerization catalyst to produce polymer components, polyethylene polymers, or polyethylene copolymers.

[0019] The unit site polymerization catalysts include (i) transition metal complexes; (ii) co-catalysts; and optionally (iii) supports; and

[0020] Its characteristics are: the product of (Weibull modulus) and (scale parameter) is equal to or greater than 40 MPa, and the ratio of (Weibull modulus) to (scale parameter) is equal to or less than 0.50 MPa. -1 The Weibull modulus and scale parameters were determined by Weibull analysis of the compressive strength of the catalyst particles.

[0021] In materials science, the Weibull distribution is commonly used to describe the variability in the fracture mechanical strength of brittle materials within a sample population. Two characteristic parameters of Weibull analysis in compression testing are the Weibull modulus and compressive strength. The Weibull modulus is a dimensionless parameter that describes the variability in the distribution of compressive strength measured among individual particles within a sample population. The Weibull modulus corresponds to the shape parameter of the Weibull distribution. In compression testing, the scale parameter of the Weibull distribution describes the compressive strength of a representative individual particle within the sample population and is expressed in MPa. A low Weibull modulus corresponds to high variability in the mechanical strength measured within the sample population and indicates a non-uniform distribution of defects in the material, leading to non-uniform fracture behavior under stress. On the other hand, a high Weibull modulus indicates a uniform distribution of defects in the material, leading to uniform fracture behavior under stress. A high scale parameter corresponds to samples with high particle strength. A low scale parameter corresponds to samples with low particle strength. Both parameters of the Weibull distribution are related to the final properties describing the material under study, and in the case of olefin polymerization catalyst particles, both parameters will affect the polymerization behavior and the final polymer powder properties.

[0022] When the unit point polymerization catalyst exhibits a (Weibull modulus) x (scale parameter) product equal to or greater than 40 MPa (preferably equal to or greater than 41 MPa, especially 42 to 75 MPa) and a (Weibull modulus) / (scale parameter) ratio equal to or less than 0.50 MPa -1 (Preferably equal to or lower than 0.49 MPa) -1 Especially 0.25 to 0.49 MPa -1 In this process, the Weibull modulus and scale parameters are determined by Weibull analysis of the compressive strength of the catalyst particles. These parameters enable the polymer powder to have high packing density in the circulating reactor and after the gas-phase reactor, as well as high productivity in the circulating reactor and throughout the polymerization process.

[0023] This disclosure specifically provides a method for polymerizing olefins in a multi-stage polymerization process configuration, the method comprising:

[0024] a) In the first polymerization step, optionally at least one other α-olefin comonomer (preferably C) 4-10 In the presence of α-olefin comonomers and a single-point polymerization catalyst, ethylene is preferably polymerized in a slurry phase to form the first polymer component (A); and

[0025] b) In the second polymerization step, in the presence of the first polymer component (A) from step a), preferably in the gas phase, optionally in at least one other α-olefin comonomer (preferably C... 4-10 In the presence of α-olefin comonomers, olefin monomers are polymerized to form a second polymer component (B).

[0026] To produce polyethylene polymers or polyethylene copolymers,

[0027] The unit-point polymerization catalyst comprises (i) a transition metal complex; (ii) a co-catalyst; and optionally (iii) a support; and is characterized in that the product of (Weibull modulus) x (scale parameter) is equal to or greater than 40 MPa (preferably equal to or greater than 41 MPa, particularly 42 to 75 MPa) and the (Weibull modulus) / (scale parameter) ratio is equal to or less than 0.50 MPa. -1 (Preferably equal to or lower than 0.49 MPa) -1 Especially 0.25 to 0.49 MPa -1 The Weibull modulus and scale parameters were determined by Weibull analysis of the compressive strength of the catalyst particles.

[0028] This disclosure specifically provides a method for olefin polymerization, including...

[0029] a) In the first polymerization step, optionally at least one other α-olefin comonomer (preferably C) 4-10 Ethylene is polymerized in the presence of α-olefin comonomers and a unit point polymerization catalyst, wherein the unit point polymerization catalyst comprises...

[0030] (i) Metallocene complex of formula (I)

[0031] (I) As stated in this article

[0032] (ii) Aluminoxane cocatalysts including formula (ii-I)

[0033] (ii-I) As described herein

[0034] And optional co-catalysts comprising compounds of Group 13 elements; and optional

[0035] (iii) Carrier;

[0036] Preferably in the slurry phase, to form the first polymer component (A); and

[0037] b) In the second polymerization step, in the presence of the first polymer component (A) from step a), preferably in the gas phase, optionally in at least one other α-olefin comonomer (preferably C... 4-10 In the presence of α-olefin comonomers, olefin monomers are polymerized to form a second polymer component (B).

[0038] To produce polyethylene polymers or polyethylene copolymers.

[0039] This disclosure also relates to a unit point aggregation, including

[0040] (i) Transition metal complexes;

[0041] (ii) co-catalysts; and

[0042] Optional (iii) carrier;

[0043] The unit-point polymerization catalyst is characterized by a (Weibull modulus) x (scale parameter) product equal to or greater than 40 MPa (preferably equal to or greater than 41 MPa, particularly 42 to 75 MPa) and a (Weibull modulus) / (scale parameter) ratio equal to or less than 0.50 MPa. -1 (Preferably equal to or lower than 0.49 MPa) -1 Especially 0.25 to 0.49 MPa -1 The Weibull modulus and scale parameters were determined by Weibull analysis of the compressive strength of the catalyst particles.

[0044] This disclosure specifically relates to a unit point aggregation, including

[0045] (i) Metallocene complex of formula (I)

[0046] (I) As stated in this article

[0047] (ii) co-catalyst;

[0048] (iii) Carrier; and

[0049] The unit-point polymerization catalyst is characterized by a (Weibull modulus) x (scale parameter) product equal to or greater than 40 MPa (preferably equal to or greater than 41 MPa, particularly 42 to 75 MPa) and a (Weibull modulus) / (scale parameter) ratio equal to or less than 0.50 MPa. -1 (Preferably equal to or lower than 0.49 MPa) -1 Especially 0.25 to 0.49 MPa -1 The Weibull modulus and scale parameters were determined by Weibull analysis of the compressive strength of the catalyst particles.

[0050] method

[0051] This disclosure relates to a method for polymerizing olefins, the method comprising optionally using at least one other α-olefin comonomer (preferably C...). 4-10 Ethylene is polymerized in the presence of α-olefin comonomers to produce polyethylene polymers or polyethylene copolymers. This method typically includes an optional but preferred prepolymerization step, followed by a first polymerization step and a second polymerization step.

[0052] Preferably, the same unit point polymerization catalyst is used in each step, and ideally, it is transferred sequentially from prepolymerization to subsequent polymerization steps in a well-known manner.

[0053] Typically, the amount of catalyst used in a single-point polymerization process depends on the properties of the catalyst, the type and conditions of the reactor, and the desired properties of the polymer product. As is well known in the art, hydrogen can be used to control the molecular weight of the polymer in any reactor.

[0054] Therefore, there exist methods for polymerizing olefins in a multi-stage polymerization configuration, which include...

[0055] a) In the first polymerization step, optionally at least one other α-olefin comonomer (preferably C) 4-10 In the presence of α-olefin comonomers and a polymerization catalyst, preferably in a slurry phase, ethylene is polymerized at a single point in the presence of the polymerization catalyst to form the first polymer component (A); and

[0056] b) In the second polymerization step, in the presence of the first polymer component from step a), preferably in the gas phase, optionally in at least one other α-olefin comonomer (preferably C... 4-10 In the presence of an α-olefin comonomer, an olefin monomer (preferably ethylene) is polymerized to form a second polymer component (B).

[0057] A preferred method configuration is based on Type cascade, especially 2G type cascading, especially 3G type cascade.

[0058] Prepolymerization step

[0059] A prepolymerization step may precede the polymerization step. The purpose of prepolymerization is to polymerize a small amount of polymer onto the catalyst at low temperatures and / or low monomer concentrations. Prepolymerization can improve the performance of the catalyst in the slurry and / or alter the properties of the final polymer.

[0060] The prepolymerization step can be carried out in a slurry or gas phase. Prepolymerization is preferably carried out in a slurry, and more preferably in a circulating reactor.

[0061] The prepolymerization is then preferably carried out in an inert diluent, which is preferably a low-boiling hydrocarbon or a mixture of such hydrocarbons having 1 to 6 carbon atoms. The temperature in the prepolymerization step is typically 0 to 90°C, preferably 20 to 80°C, more preferably 25 to 70°C. Pressure is not critical and is typically 1 to 150 bar, preferably 10 to 100 bar.

[0062] The amount of polymer produced in the optional prepolymerization step is included in the amount (wt%) of the ethylene polymer component (A).

[0063] When a prepolymerization step is present, a unit point polymerization catalyst is introduced into the prepolymerization step. Preferably, the reaction products of the prepolymerization step are then introduced into the first reactor.

[0064] It should be understood that, within the scope of this invention, the amount of polymer produced in the prepolymerization is between 1 and 7 wt% relative to the final multimodal (co)polymer. This can be considered as part of the first polymer component (A) produced in the first polymerization step a).

[0065] First polymerization step a)

[0066] In this method, the first polymerization step a) involves polymerizing ethylene monomer and optionally at least one olefin comonomer, preferably C 4-10 α-olefin comonomer.

[0067] In one implementation, the first polymerization step involves polymerizing ethylene to produce an ethylene homopolymer.

[0068] In another embodiment, the first polymerization step involves polymerizing ethylene and at least one olefin comonomer to produce an ethylene copolymer.

[0069] The polymerization in the first polymerization step a) is carried out in the presence of a unit point polymerization catalyst, as detailed below.

[0070] The first polymerization step can be carried out in any suitable reactor or a series of reactors. The first polymerization step can be carried out in one or more slurry polymerization reactors. The first polymerization step is preferably carried out in one or more slurry polymerization reactors, more preferably in at least three slurry phase reactors, for example exactly three slurry phase reactors, including one slurry phase reactor for prepolymerization.

[0071] Polymerization in the first polymerization zone is preferably carried out in a slurry. The polymer particles formed during polymerization are then suspended in a fluid hydrocarbon along with a catalyst that has been broken up and dispersed within the particles. The slurry is stirred to transfer the reactants from the fluid into the particles.

[0072] Slurry polymerization is typically carried out in an inert diluent, usually a hydrocarbon diluent such as methane, ethane, propane, n-butane, isobutane, pentane, hexane, heptane, octane, or mixtures thereof. Preferably, the diluent is a low-boiling-point hydrocarbon or a mixture of such hydrocarbons having 1 to 4 carbon atoms. A particularly preferred diluent is propane, which may contain small amounts of methane, ethane, and / or butane.

[0073] The ethylene content in the fluid phase of the slurry can be from 2 to about 50 mol%, preferably from about 3 to about 20 mol%, and particularly from about 5 to about 15 mol%. The advantage of having a high ethylene concentration is increased catalyst productivity, but the disadvantage is that more ethylene needs to be recovered compared to lower concentrations.

[0074] The temperature during slurry polymerization is typically 50 to 115°C, preferably 60 to 110°C, and particularly 70 to 100°C. The pressure is 1 to 150 bar, preferably 10 to 100 bar.

[0075] The pressure in the first polymerization step is typically 35 to 80 bar, preferably 40 to 75 bar, and especially 45 to 70 bar.

[0076] The residence time in the first polymerization step is typically from 0.15 hours to 3.0 hours, preferably from 0.20 hours to 2.0 hours, and particularly from 0.30 hours to 1.5 hours.

[0077] Sometimes it is advantageous to carry out slurry polymerization above the critical temperature and pressure of the fluid mixture. Such an operation is described in US-A-5391654. In such an operation, the temperature is typically 85 to 110°C, preferably 90 to 105°C, and the pressure is 40 to 150 bar, preferably 50 to 100 bar.

[0078] Slurry polymerization can be carried out in any known reactor used for slurry polymerization. Such reactors include continuous stirred tank reactors and circulating reactors. Polymerization is particularly preferred in circulating reactors. In a circulating reactor, the slurry is circulated at high speed along a closed pipe using a circulating pump. Circulating reactors are well known in the art, and examples are given for example in US-A-4582816, US-A-3405109, US-A-3324093, EP-A-479186, and US-A-5391654.

[0079] The slurry can be discharged from the reactor continuously or intermittently. Intermittent discharge is preferably achieved using a settling leg, where the slurry is concentrated before being discharged from the reactor in batches. The use of settling legs is disclosed, among others, in US-A-3374211, US-A-3242150, and EP-A-1310295. Continuous discharge is disclosed, among others, in EP-A-891990, EP-A-1415999, EP-A-1591460, and WO-A-2007 / 025640. As disclosed in EP-A-1310295, EP-A-1591460, and EP3178853B1, continuous discharge is advantageously combined with suitable concentration methods.

[0080] As is known in the art, hydrogen can be supplied to the reactor to control the molecular weight of the polymer. Furthermore, one or more α-olefin comonomers can be added to the reactor to control the density of the polymer product. The actual amounts of hydrogen and comonomer feed depend on the catalyst used and the desired melt index (or molecular weight) and density (or comonomer content) of the resulting polymer.

[0081] Second polymerization step

[0082] The first polymer component is transferred from the first polymerization step to the second polymerization step.

[0083] The polymerization in the first polymerization step b) is carried out in the presence of a unit point polymerization catalyst, as detailed below.

[0084] In this method, the second polymerization step b) involves polymerizing ethylene monomer and optionally at least one other α-olefin comonomer, preferably C. 4-10 α-olefin comonomer.

[0085] In one embodiment, the second polymerization step involves polymerizing ethylene and 1-hexene, and optionally at least one olefin comonomer, to produce either a polyethylene copolymer or an ethylene terpolymer.

[0086] The second polymerization step is preferably carried out in one or more gas-phase polymerization reactors.

[0087] Gas-phase polymerization is typically carried out in gas-solid fluidized beds (also known as gas-phase reactors (GPRs)). Gas-solid olefin polymerization reactors are commonly used for the polymerization of α-olefins (such as ethylene and propylene) because they offer relatively high flexibility in polymer design and the use of various catalyst systems. A common variant of gas-solid olefin polymerization reactors is the fluidized bed reactor.

[0088] A gas-solid olefin polymerization reactor is a polymerization reactor used for the multiphase polymerization of gaseous olefin monomers into polyolefin powder particles. It comprises three zones: a bottom zone where fluidizing gas is introduced into the reactor; a middle zone, typically cylindrical, where the olefin monomers present in the fluidizing gas polymerize to form polymer particles; and a top zone where the fluidizing gas is discharged from the reactor. In some types of gas-solid olefin polymerization reactors, a fluidizing grid (also called a distribution plate) separates the bottom zone from the middle zone. In some types of gas-solid olefin polymerization reactors, the top zone forms a separation or entrainment zone, where the fluidizing gas expands and separates from the polyolefin powder due to its increased diameter compared to the middle zone.

[0089] The dense phase refers to the region in the middle of a gas-solid olefin polymerization reactor that has increased bulk density due to the formation of polymer particles. In some types of gas-solid olefin polymerization reactors, namely fluidized bed reactors, the dense phase is formed by the fluidized bed.

[0090] The temperature in gas-phase polymerization is typically 40 to 120°C, preferably 50 to 100°C, and more preferably 65 to 90°C.

[0091] The pressure in gas-phase polymerization is typically 3 to 40 bar, preferably 5 to 35 bar, more preferably 10 to 32 bar, and even more preferably 15 to 30 bar.

[0092] The residence time in gas-phase polymerization is 1.0 hour to 4.5 hours, preferably 1.5 hours to 4.0 hours, and particularly 2.0 to 3.5 hours.

[0093] The polymer production rate in the gas phase reactor can be from 10 tn / h to 65 tn / h, preferably from 12 tn / h to 58 tn / h, and particularly from 13 tn / h to 52.0 tn / h. Therefore, the total polymer discharge rate from the gas phase reactor can be from 15 tn / h to 100 tn / h, preferably from 18 tn / h to 90 tn / h, and particularly from 20 tn / h to 80.0 tn / h.

[0094] The production ratio (% of second polymer component (B) / % of first polymer component (A)) can be from 0.65 to 2.5, preferably from 0.8 to 2.3, and most preferably from 1.0 to 1.65.

[0095] Gas-phase polymerization can be carried out in any known reactor used for gas-phase polymerization. Such reactors include fluidized bed reactors, fast fluidized bed reactors, or settling bed reactors, or any combination thereof. When using a combined reactor, the polymer is transferred from one polymerization reactor to another. Furthermore, some or all of the polymer from the polymerization stage can be returned to the previous polymerization stage.

[0096] It is generally preferred to remove the reactants from the previous polymerization stage from the polymer before introducing it into subsequent polymerization stages. This is preferably done when transferring the polymer from one polymerization stage to another.

[0097] Unit point polymerization catalyst

[0098] The polymerization catalyst used in this method is a single-site polymerization catalyst. A single-site polymerization catalyst typically includes (i) a transition metal complex, (ii) a co-catalyst, and optionally (iii) a support.

[0099] Preferably, the first and second polymerization steps are carried out using the same single-point polymerization catalyst (preferably a metallocene catalyst), i.e., in its presence.

[0100] The catalyst can be transferred to the first reactor by any means known in the art. For example, the catalyst can be suspended in a diluent and kept as a slurry, the catalyst can be mixed with a viscous mixture of grease and oil and the resulting paste can be fed into the polymerization zone, or the catalyst can be allowed to settle and a portion of the resulting catalyst slurry can be introduced into the polymerization.

[0101] This method utilizes single-point catalysis. In contrast to Ziegler-Natta catalysis, polyethylene copolymers prepared using single-point catalysis exhibit characteristics that distinguish them from Ziegler-Natta materials. In particular, the comonomer distribution is more uniform. This can be visualized using TREF or Crystaf techniques. Catalyst residues can also indicate the catalyst used. For example, Ziegler-Natta catalysts do not contain Zr or Group IV (Hf) metals.

[0102] The product of the (Weibull modulus) and (scale parameter) of the catalyst at this unit point is equal to or greater than 40 MPa (preferably equal to or greater than 41 MPa, especially 42 to 75 MPa) and the (Weibull modulus) / (scale parameter) ratio is equal to or less than 0.50 MPa. -1 (Preferably equal to or lower than 0.49 MPa) -1 Especially 0.25 to 0.49 MPa -1 The Weibull modulus and scale parameters were determined by Weibull analysis of the compressive strength of the catalyst particles.

[0103] The unit point polymerization catalyst preferably has a compressive strength of at least 5 MPa, more preferably at least 5.5 MPa, particularly 6 to 25 MPa, more preferably 7 to 20 MPa, and even more preferably 7 to 15 MPa.

[0104] The individual crushing strength of any 10 or more particles (e.g., exactly 10 particles) can be measured using a compression tester under an inert atmosphere, and the average of the measurements is calculated as the compressive strength of the polymerization catalyst, thereby determining the compressive strength. Preferably, the average of the measurements is calculated after removing statistical outliers. The crushing strength can be measured using the MCT-510 micro-compression tester manufactured by Shimadzu Seisakusho Ltd.

[0105] The ratio of the co-catalyst (ii) to the transition metal complex (i) in the unit site polymerization catalyst is preferably greater than 50 mol / mol, preferably 60 to 200 mol / mol, and more preferably 100 to 160 mol / mol.

[0106] Transition metal complexes (i)

[0107] Transition metal complexes include transition metals (M) or actinides or lanthanides from Groups 3 to 10 of the periodic table (IUPAC 2007).

[0108] The term "transition metal complex" according to the present invention includes any metallocene or nonmetallocene compound of a transition metal that carries at least one organic (coordinating) ligand and exhibits catalytic activity alone or in conjunction with a co-catalyst. Transition metal compounds are well known in the art, and the present invention covers metal compounds of Groups 3 to 10 of the Periodic Table (IUPAC 2007), such as Groups 3 to 7 or Groups 3 to 6, such as Groups 4 to 6, as well as lanthanides or actinides.

[0109] Most preferably, the transition metal complex (i) is a metallocene complex comprising a transition metal compound as defined above.

[0110] Benzomet metal complexes can have the structure of formula (I):

[0111]

[0112] Each X is a σ donor ligand;

[0113] Each Het is independently a monocyclic or polycyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S;

[0114] L is a divalent bridge based on carbon, silicon, or germanium, in which one or two framework atoms connect to the ligand;

[0115] M is Ti, Zr, or Hf;

[0116] Each R1 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy, benzyl, O-benzyl, optionally with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl or optionally substituted with 1 to 3 carbons 1-6 Alkyl-substituted O-phenyl; and / or

[0117] Two adjacent R1 groups together with the atoms they are attached to form another ring, for example, thus forming an indene ring with the Cp ring, said other ring being optionally replaced by up to four R3 groups;

[0118] Each R3 is the same or different, for C 1-10 Alkyl, C 1-10 Alkyl groups or optionally alkoxy groups with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl;

[0119] Each n is between 0 and 3;

[0120] Each R2 is the same or different, for C 1-10Alkyl, C 1-10 Alkoxy or -Si(R)3 group;

[0121] Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and

[0122] Each p is between 0 and 3.

[0123] The following preferred selections are all general formulas applicable to this article.

[0124] M is preferably Zr or Hf, more preferably Zr.

[0125] Each X is an independent σ donor ligand. Therefore, each X can be the same or different, and is preferably a hydrogen atom, a halogen atom, a straight-chain or branched chain, or a cyclic or acyclic C atom. 1-20 Alkyl or C 1-20 Alkoxy, C 6-20 Aryl, C 7-20 alkylaryl or C 7-20 Aryl alkyl group.

[0126] In one embodiment, the X group may be trihydrocarbylsilyl, C 1-10 Alkoxy, C 1-10 Alkoxy-C 1-10 Alkyl or amide group.

[0127] The term halogen includes fluorine, chlorine, bromine, and iodine groups, with chlorine groups being preferred.

[0128] The relevant amide groups are -NH2 and -NHC. 1-6 Alkyl or -N(C) 1-6 Alkyl)2.

[0129] More preferably, each X is independently a hydrogen atom, a halogen atom, or a carbon atom. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl.

[0130] More preferably, each X is independently a halogen atom, a straight-chain or branched C atom. 1-4 Alkyl or C 1-4 Alkoxy, phenyl, or benzyl.

[0131] Most preferably, each X is independently chlorine, benzyl, cyclohexyl or methyl.

[0132] Preferably, the two X groups are identical.

[0133] The most preferred choice for the two X groups is two chlorine groups, two methyl groups, or two benzyl groups.

[0134] L is a bridge based on carbon, silicon, or germanium. There are one or two skeletal connecting atoms between the two ligands, such as the structure of ligand-C-ligand (one skeletal atom) or ligand-Si-Si-ligand (two skeletal atoms).

[0135] The bridging atom can carry other groups. For example, suitable bridging ligands L are selected from -R'2C-, -R'2C-CR'2-, -R'2Si-, -R'2Si-SiR'2-, and -R'2Ge-, where each R' is independently a hydrogen atom or optionally a C atom containing one or more heteroatoms or fluorine atoms from groups 14 to 16 of the periodic table. 1-20 A hydrocarbon group, or optionally two R' groups together, can form a ring. In one embodiment, R' may be an alkyl group having 1 to 10 carbon atoms substituted with an alkoxy group having 1 to 10 carbon atoms.

[0136] The term heteroatoms, which belong to groups 14 to 16 of the periodic table, include, for example, Si, N, O, or S.

[0137] Preferably, L is -R'2Si-, ethylene, or methylene.

[0138] In equation -R'2Si-, each R' is independently preferably C. 1-20 Hydrocarbon group. Therefore, the term C 1-20 Hydrocarbon groups include C 1-20 Alkyl, C 2-20 alkenyl, C 2-20 alkynyl group, C 3-20 cycloalkyl, C 3-20 Cycloalkenyl, C 6-20 Aryl, C 7-20 Alkyl, C 7-20 Aryl alkyl groups or mixtures of these groups, such as cycloalkyl groups substituted with alkyl groups. Unless otherwise specified, C is preferred. 1-20 The hydrocarbon group is C 1-20 Alkyl, C 2-20 alkenyl, C 4-20 cycloalkyl, C 5-20 cycloalkylalkyl, C 7-20 Alkyl, C 7-20 Aryl or C 6-20 Aryl.

[0139] In one embodiment, the formula -R'2Si- represents a silcycloalkane dieryl, such as silcyclobutane, silcyclopentane, or 9-silfluorene.

[0140] Preferably, the two R' groups are identical. Preferably, R' is C. 1-10 The R' group is a hydrocarbon group or an alkyl group having 1-10 carbon atoms substituted with an alkoxy group having 1-10 carbon atoms. Preferred R' groups are methyl, ethyl, propyl, isopropyl, tert-butyl, isobutyl, C...2-10 alkenyl, C 3-8 Cycloalkyl, cyclohexylmethyl, phenyl, or benzyl, more preferably, each R' independently is C 1-6 Alkyl, C 2-10 alkenyl, C 5-6 Cycloalkyl or phenyl, most preferably, both R' are methyl or one is methyl and the other is cyclohexyl. Most preferably, the bridge is -Si(CH3)2-.

[0141] The het groups can be the same or different, but are preferably the same. The het group is a monocyclic or polycyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N, or S. If N is present in the ring, it can be accompanied by H or C, depending on the ring structure. 1-6 alkyl.

[0142] Preferably, the Het group is monocyclic. Preferably, the Het group is a heteroaromatic group. Preferably, the Het group is a monocyclic heteroaromatic group. Preferably, the Het group has a 5- or 6-membered heteroaromatic or heterocyclic structure.

[0143] Preferred Het groups include furanyl, tetrahydrofuranyl, thiophenyl, pyridyl, piperidinyl, or pyrroleyl.

[0144] Preferably, the Het ring contains one heteroatom. Preferably, the heteroatom is O or S, preferably O. Most preferably, the Het group is furanyl. Preferably, the connection between the Het group and the cyclopentadienyl ring is located on a carbon adjacent to the heteroatom. Preferably, the connection between the Cp group and the Het ring is located on a carbon adjacent to the linker L.

[0145] Each R1 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy, benzyl, O-benzyl (i.e., OBz), C 6-10 Aryl, OC 6-10 Aryl, optional 1 to 3 C 1-6 Alkyl-substituted phenyl or optionally substituted with 1 to 3 carbons 1-6 Alkyl-substituted O-Ph;

[0146] and / or

[0147] Two adjacent R1 groups together with the atoms they are attached to form another ring, such as an indene ring with the Cp ring, which is optionally replaced by up to four R3 groups.

[0148] However, it is preferable that there is no fused ring, so that the ligand contains two cyclopentadienyl rings.

[0149] Each R1 is preferably C 1-6 Alkyl, C 1-6Alkoxy, benzyl, or optionally surrounded by 1 to 3 carbons 1-6 Alkyl-substituted phenyl groups.

[0150] More preferably, R1 is C 1-6 Alkyl groups, such as methyl, ethyl, or tert-butyl.

[0151] The subscript "n" is preferably 1 or 2, meaning that the ring is preferably substituted. If n is 2, then R1 is preferably methyl. If n is 1, then R1 is preferably tert-butyl.

[0152] If n is greater than 1, it is preferable that the R1 group does not bond with the same C atom.

[0153] If n = 2, then the R1 group is preferably adjacent. If n = 2, then the R1 group is preferably attached to the carbon adjacent to bridge L and the next carbon.

[0154] If n = 1, then the R1 group is preferably not adjacent to the linker L or the Het group.

[0155] Each R2 is the same or different, for C 1-10 Alkyl, C 1-10 The alkoxy or -Si(R)3 group is preferred. R2 is preferably a -Si(R)3 group.

[0156] Each R is independently C 1-6 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl groups. Therefore, each R group may be the same or different.

[0157] The R group is preferably phenyl or C. 1-4 Alkyl, particularly methyl or phenyl. In one embodiment, one R is phenyl and the other R groups are C. 1-4 Alkyl groups, such as methyl groups. In another embodiment, all R groups are C10. 1-4 Alkyl groups. -SiPhMe2 or SiMe3 are preferred.

[0158] Preferably, p is 0 or 1, and more preferably p = 1.

[0159] If p is not 0, the R2 substituent is preferably located on a carbon adjacent to the heteroatom. Preferably, the R2 group is not bonded to the same carbon atom that connects to the Cp ring. If the Het group is a furanyl group, it is preferred that the Het ring is connected to the Cp ring and the Het group (if present) via two carbons adjacent to O.

[0160] The complex used in this invention is preferably as shown in formula (II):

[0161]

[0162] Each X is independently a hydrogen atom, a halogen atom, or a carbon atom. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0163] Each Het is independently a monocyclic or polycyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S;

[0164] L is either -R'2C- or -R'2Si-, where each R' is independently C. 1-20 The C group is either a hydrocarbon group or a C group substituted with an alkoxy group having 1 to 10 carbon atoms. 1-10 alkyl;

[0165] M is Ti, Zr, or Hf;

[0166] Each R1 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy, benzyl, O-benzyl, optionally with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl or optionally substituted with 1 to 3 carbons 1-6 Alkyl-substituted O-phenyl; and / or

[0167] Two adjacent R1 groups together with the atoms they are attached to form another ring, for example, thus forming an indene ring with the Cp ring, said other ring being optionally replaced by up to four R3 groups;

[0168] Each R3 is the same or different, for C 1-6 Alkyl, C 1-6 Alkyl groups or optionally alkoxy groups with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl;

[0169] Each n is between 0 and 3;

[0170] Each R2 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy or -Si(R)3 group;

[0171] Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and

[0172] Each p is between 0 and 3.

[0173] Benzomet metal complexes are preferably as shown in formula (III):

[0174]

[0175] Each X is independently a hydrogen atom, a halogen atom, or a carbon atom. 1-6 Alkyl, C 1-6Alkoxy, amide, phenyl, or benzyl groups;

[0176] Each Het is independently a monocyclic or polycyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S;

[0177] L is either -R'2C- or -R'2Si-, where each R' is independently C. 1-20 The C group is either a hydrocarbon group or a C group substituted with an alkoxy group having 1 to 10 carbon atoms. 1-10 alkyl;

[0178] M is Ti, Zr, or Hf;

[0179] Each R1 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy, benzyl, O-benzyl, optionally with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl or optionally substituted with 1 to 3 carbons 1-6 Alkyl-substituted O-phenyl;

[0180] Each n is between 0 and 3;

[0181] Each R2 is the same or different, for C 1-6 Alkyl, C 1-6 Alkoxy or -Si(R)3 group;

[0182] Each R is C 1-6 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and

[0183] Each p is between 0 and 3.

[0184] Benzomet metal complexes are preferably as shown in formula (IV):

[0185]

[0186] Each X is independently a hydrogen atom, a halogen atom, or a carbon atom. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0187] Each Het is independently a monocyclic heteroaromatic group containing at least one heteroatom selected from O, N or S;

[0188] L is either -R'2C- or -R'2Si-, where each R' is independently C. 1-20 The C group is either a hydrocarbon group or a C group substituted with an alkoxy group having 1 to 10 carbon atoms. 1-10 alkyl;

[0189] M is Ti, Zr, or Hf;

[0190] Each R1 is the same or different, for C 1-6 Alkyl or C 1-6 Alkoxy;

[0191] Each n is between 0 and 3;

[0192] Each R2 is the same or different, for C 1-6 Alkyl, C 1-6 Alkoxy or -Si(R)3 group;

[0193] Each R is independently C 1-6 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and

[0194] Each p is between 0 and 3.

[0195] Benzomet metal complexes are preferably as shown in formula (V):

[0196]

[0197] Each X is independently a hydrogen atom, a halogen atom, or a carbon atom. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0198] Each Het is independently a monocyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O or S;

[0199] L is -R'2Si-, where each R' is independently C. 1-20 The C group is either a hydrocarbon group or a C group substituted with an alkoxy group having 1 to 10 carbon atoms. 1-10 alkyl;

[0200] M is Ti, Zr, or Hf;

[0201] Each R1 is the same or different, for C 1-6 Alkyl or C 1-6 Alkoxy;

[0202] Each n is between 1 and 2;

[0203] Each R2 is the same or different, for C 1-6 Alkyl, C 1-6 Alkoxy or -Si(R)3 group;

[0204] Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and

[0205] Each p is between 0 and 1.

[0206] The complex used in this invention is preferably as shown in formula (VI):

[0207]

[0208] Each X is independently a hydrogen atom, a halogen atom, or a carbon atom. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0209] Each Het is independently a monocyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O or S;

[0210] L is -R'2Si-, where each R' is independently C. 1-10 Alkyl, C 3-8 cycloalkyl or C 2-10 alkenyl;

[0211] M is Ti, Zr, or Hf;

[0212] Each R1 is the same or different, for C 1-6 alkyl;

[0213] Each n is between 1 and 2;

[0214] Each R2 may be the same or different, and is a -Si(R)3 group;

[0215] Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and

[0216] Each p is between 0 and 1.

[0217] Benzomet metal complexes are preferably as shown in formula (VII):

[0218]

[0219] Each X is a σ donor ligand, for example, each X is independently a hydrogen atom, a halogen atom, a carbon atom, etc. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0220] L is a divalent bridge based on carbon, silicon, or germanium, where one or two framework atoms connect to a ligand, such as -R'2Si-, where each R' is independently C. 1-20 The C group is either a hydrocarbon group or a C group substituted with an alkoxy group having 1 to 10 carbon atoms. 1-10 alkyl;

[0221] Each R1 is the same or different, for C 1-6 alkyl;

[0222] Each n is between 0 and 3;

[0223] Each R2 is the same or different, for C1-6 Alkyl or -Si(R)3 group;

[0224] Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and

[0225] Each p is between 0 and 3.

[0226] Benzomet metal complexes are preferably as shown in formula (VIII):

[0227]

[0228] Each X is a σ donor ligand, for example, each X is independently a hydrogen atom, a halogen atom, a carbon atom, etc. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0229] L is a divalent bridge based on carbon, silicon, or germanium, where one or two framework atoms connect to a ligand, such as -R'2Si-, where each R' is independently C. 1-20 The C group is either a hydrocarbon group or a C group substituted with an alkoxy group having 1 to 10 carbon atoms. 1-10 alkyl;

[0230] Each R1 is the same or different, for C 1-6 alkyl;

[0231] Each n is between 1 and 2;

[0232] R2 is a -Si(R)3 alkyl group;

[0233] Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl;

[0234] Each p is 1.

[0235] Benzomet metal complexes are preferably as shown in formula (IX):

[0236]

[0237] Each X is a σ donor ligand, for example, each X is independently a hydrogen atom, a halogen atom, a carbon atom, etc. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0238] L is Me2Si- or (Me)C 2-10 Alkenyl Si;

[0239] Each R1 is the same or different, for C 1-6 Alkyl groups, such as methyl or tert-butyl;

[0240] Each n is between 1 and 2;

[0241] R2 is a -Si(R)3 alkyl group;

[0242] Each R is C 1-6 Alkyl or phenyl;

[0243] Each p is 1;

[0244] For example, equation (IX')

[0245]

[0246] Each X is a σ donor ligand, for example, each X is independently a hydrogen atom, a halogen atom, a carbon atom, etc. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0247] L is Me2Si- or (Me)C 2-10 Alkenyl Si;

[0248] Each R1 is the same or different, for C 1-6 Alkyl groups, such as methyl or tert-butyl;

[0249] Each n is between 1 and 2;

[0250] R2 is a -Si(R)3 alkyl group;

[0251] Each R is C 1-6 Alkyl or phenyl.

[0252] Benmohexagonal metal complexes are particularly shown as in formula (X):

[0253]

[0254] Each X is a σ donor ligand, for example, each X is independently a hydrogen atom, a halogen atom, a carbon atom, etc. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0255] L is a divalent bridge based on carbon, silicon, or germanium, where one or two framework atoms connect to a ligand, such as -R'2Si-, where each R' is independently C. 1-20 The C group is either a hydrocarbon group or a C group substituted with an alkoxy group having 1 to 10 carbon atoms. 1-10 alkyl;

[0256] M is Ti, Zr, or Hf;

[0257] Each Het is independently a monocyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S;

[0258] Each R1 is the same or different, for C 1-10 alkyl;

[0259] Each n is between 1 and 3;

[0260] Each R2 may be the same or different, and is a -Si(RaRbRc) group;

[0261] Ra is C 1-6 alkyl;

[0262] Rb is C 1-6 alkyl;

[0263] Rc is randomly selected from 1 to 3 Cs. 1-6 Alkyl-substituted phenyl; and

[0264] Each p is between 1 and 3;

[0265] For example, equation (X')

[0266]

[0267] Each X is a σ donor ligand, for example, each X is independently a hydrogen atom, a halogen atom, a carbon atom, etc. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0268] L is a divalent bridge based on carbon, silicon, or germanium, where one or two framework atoms connect to a ligand, such as -R'2Si-, where each R' is independently C. 1-20 The C group is either a hydrocarbon group or a C group substituted with an alkoxy group having 1 to 10 carbon atoms. 1-10 alkyl;

[0269] Each R1 is the same or different, for C 1-10 alkyl;

[0270] Each n is between 1 and 3;

[0271] Each R2 may be the same or different, and is a -Si(RaRbRc) group;

[0272] Ra is C 1-6 alkyl;

[0273] Rb is C 1-6 alkyl;

[0274] Rc is randomly selected from 1 to 3 Cs. 1-6 Alkyl-substituted phenyl groups.

[0275] A more preferred complex is the complex of formula (XI).

[0276]

[0277] Each X is a σ donor ligand, for example, each X is independently a hydrogen atom, a halogen atom, a carbon atom, etc. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0278] L is a divalent bridge based on carbon, silicon, or germanium, where one or two framework atoms connect to a ligand, such as -R'2Si-, where each R' is independently C. 1-20 The C group is either a hydrocarbon group or a C group substituted with an alkoxy group having 1 to 10 carbon atoms. 1-10 alkyl;

[0279] Each Het is independently a monocyclic heteroaromatic group containing at least one heteroatom selected from O, N or S;

[0280] M is Ti, Zr, or Hf;

[0281] Each R1 is the same or different, forming a branch C. 3-10 alkyl;

[0282] Each R2 may be the same or different, and is a -Si(R)3 group;

[0283] Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and

[0284] Each p is 1.

[0285] For example, equation (XI')

[0286]

[0287] Each X is a σ donor ligand, for example, each X is independently a hydrogen atom, a halogen atom, a carbon atom, etc. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0288] L is a divalent bridge based on carbon, silicon, or germanium, where one or two framework atoms connect to a ligand, such as -R'2Si-, where each R' is independently C. 1-20 The C group is either a hydrocarbon group or a C group substituted with an alkoxy group having 1 to 10 carbon atoms. 1-10 alkyl;

[0289] Each R1 is the same or different, forming a branch C. 3-10 alkyl;

[0290] Each R2 may be the same or different, and is a -Si(R)3 group;

[0291] Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6Alkyl-substituted phenyl groups.

[0292] Even more preferred metallocene complexes are those of formula (XII).

[0293]

[0294] Each X is a σ donor ligand, for example, each X is independently a hydrogen atom, a halogen atom, a carbon atom, etc. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0295] Each Het is independently a monocyclic heteroaromatic group containing at least one heteroatom selected from O, N or S;

[0296] L represents the (RdRe)Si group;

[0297] Rd is C 1-10 alkyl;

[0298] Re is C 2-10 alkenyl;

[0299] M is Ti, Zr, or Hf;

[0300] Each R1 is the same or different, for C 1-10 alkyl;

[0301] Each n is between 1 and 3;

[0302] Each R2 may be the same or different, and is a -Si(R)3 group;

[0303] Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and

[0304] Each p is between 0 and 3.

[0305] For example, equation (XII')

[0306]

[0307] Each X is a σ donor ligand, for example, each X is independently a hydrogen atom, a halogen atom, a carbon atom, etc. 1-6 Alkyl, C 1-6 Alkoxy, amide, phenyl, or benzyl groups;

[0308] L represents the (RdRe)Si group;

[0309] Rd is C 1-10 alkyl;

[0310] Re is C 2-10 alkenyl;

[0311] Each R1 is the same or different, for C 1-10 alkyl;

[0312] Each n is between 1 and 3;

[0313] Each R2 may be the same or different, and is a -Si(R)3 group;

[0314] Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl groups.

[0315] The highly preferred complex is

[0316]

[0317]

[0318] Co-catalyst (ii)

[0319] In order to form an active catalytic substance, a co-catalyst well known in the art is usually required.

[0320] According to the present invention, a cocatalyst containing a Group 13 element is needed, such as a boron-containing cocatalyst or an aluminum-containing cocatalyst. Combining an aluminoxane cocatalyst with a metallocene catalyst complex as defined above is most preferred.

[0321] Aluminoxane catalysts can be one of formula (ii-I):

[0322]

[0323] Where n is between 6 and 20 and R has the following meanings.

[0324] Aluminoxanes are formed by the partial hydrolysis of organoaluminum compounds such as AlR3, AlR2Y, and Al2R3Y3, where R can be, for example, C. 1-10 Alkyl (preferably C) 1-5 alkyl) or C 3-10 cycloalkyl, C 7-12 Aryl or alkylaryl and / or phenyl or naphthyl, wherein Y may be hydrogen, halogen (preferably chlorine or bromine) or C. 1-10 Alkoxy groups (preferably methoxy or ethoxy). The resulting oxyaluminoxanes are usually not pure compounds, but mixtures of oligomers of formula (ii-I).

[0325] The preferred aluminoxane is methylaluminoxane (MAO). Since the aluminoxane used as a cocatalyst according to the present invention is not a pure compound due to its preparation method, the molar concentration of the aluminoxane solution hereinafter is based on its aluminum content.

[0326] Boron-containing co-catalysts can also be used, optionally in combination with aluminum oxane co-catalysts.

[0327] Related boron-containing cocatalysts include cocatalysts of formula (ii-II).

[0328] BY3(ii-II)

[0329] Wherein Y may be the same or different, and may be a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 15 carbon atoms, an alkylaryl group having 1 to 10 carbon atoms in the alkyl group and 6 to 20 carbon atoms in the aryl group, an aralkyl group, a haloalkyl group, or a haloaryl group, or fluorine, chlorine, bromine, or iodine. Preferred examples of Y are fluorine, trifluoromethyl, or aromatic fluorinated groups such as p-fluorophenyl, 3,5-difluorophenyl, pentafluorophenyl, 3,4,5-trifluorophenyl, and 3,5-di(trifluoromethyl)phenyl. Preferred alternatives are trifluoroborane, tri(4-fluorophenyl)borane, tri(3,5-difluorophenyl)borane, tri(4-fluoromethylphenyl)borane, tri(2,4,6-trifluorophenyl)borane, tri(pentafluorophenyl)borane, tri(3,5-difluorophenyl)borane, and / or tri(3,4,5-trifluorophenyl)borane.

[0330] Tris(pentafluorophenyl)borane is particularly preferred.

[0331] However, borates, i.e. compounds containing borates, are preferred.

[0332] These compounds typically contain anions of formula (ii-III):

[0333] (Z)4B-(ii-III)

[0334] Where Z is an optionally substituted phenyl derivative, and the substituent is a halogenated C. 1-6 Alkyl or halogenated groups. Preferred options are fluorine or trifluoromethyl. Most preferably, the phenyl group is perfluorinated.

[0335] Such ionic cocatalysts preferably contain weakly coordinating anions, such as tetra(pentafluorophenyl)borate or tetra(3,5-di(trifluoromethyl)phenyl)borate.

[0336] Suitable cationic counterions include triphenylcarbocations and are protonated amines or aniline derivatives, such as methylammonium, phenylammonium, dimethylammonium, diethylammonium, N-methylaniline, diphenylammonium, N,N-dimethylphenylammonium, trimethylammonium, triethylammonium, tri-n-butylammonium, methyldiphenylammonium, pyridinium, p-bromo-N,N-dimethylaniline, or p-nitro-N,N-dimethylaniline.

[0337] Preferred ionic compounds that can be used according to the present invention include:

[0338] Tributylammonium tetra(pentafluorophenyl)borate, Tributylammonium tetra(trifluoromethylphenyl)borate

[0339] Tributylammonium tetra(4-fluorophenyl)borate,

[0340] N,N-Dimethylcyclohexylammonium tetra(pentafluorophenyl)borate,

[0341] N,N-Dimethylbenzylammonium tetra(pentafluorophenyl)borate,

[0342] N,N-Dimethylaniline tetra(pentafluorophenyl)borate,

[0343] N,N-Di(propyl)ammonium tetra(pentafluorophenyl)borate,

[0344] Di(cyclohexyl)ammonium tetra(pentafluorophenyl)borate,

[0345] Triphenylcarbazone (pentafluorophenyl) borate

[0346] Or ferrocene tetra(pentafluorophenyl)borate.

[0347] Triphenylcarbatote (pentafluorophenyl) borate is preferred.

[0348] N,N-Dimethylaniline tetra(pentafluorophenyl)borate,

[0349] N,N-Dimethylcyclohexylammonium tetra(pentafluorophenyl)borate or

[0350] N,N-Dimethylbenzylammonium tetra(pentafluorophenyl)borate.

[0351] Therefore, the preferred borates used in this invention contain triphenylmethyl, i.e., triphenyl carbocations. Ph3CB(PhF5)4 and its analogues are particularly preferred.

[0352] The appropriate amount of co-catalyst is well known to those skilled in the art.

[0353] Carrier (iii)

[0354] The polymerization catalyst can be used in solid but unsupported form according to the scheme in WO03 / 051934. The polymerization catalyst is preferably used in solid supported form. The particulate support material used can be an inorganic porous support, such as silica, alumina, or a mixed oxide, such as silica-alumina, especially silica.

[0355] Silica carrier is preferred.

[0356] Particularly preferred is that the carrier is a porous material, so that the complex can be loaded into the pores of the particulate carrier, for example using methods similar to those described in WO94 / 14856, WO95 / 12622, WO2006 / 097497 and EP1828266.

[0357] The average particle size of the support, such as silica support, is typically 10 to 100 μm. Preferably, the average particle size of the silica support is 10 to 40 μm, more preferably 15 to 35 μm. Average particle size (i.e., median particle size, D) 50 The particle size distribution can be determined using a Malvern Mastersizer 3000 laser diffraction particle size analyzer and a dry powder sample dispersion.

[0358] The average pore size of the support, such as silica support, can be in the range of 10 to 100 nm and the pore volume is 1 to 3 mL / g.

[0359] Examples of suitable support materials are, for example, ES757 manufactured and sold by PQ Corporation, Sylopol 948 manufactured and sold by Grace, or SUNSPERA DM-L-303 silica manufactured by AGC Si-Tech Co. The support may optionally be calcined during catalyst preparation prior to use to achieve optimal silanol content.

[0360] Each gram of catalyst support (iii) (e.g., silica) may contain 5 to 500 μmol (e.g., 10 to 200 μmol) of transition metal complex (i) and 3 to 15 mmol of co-catalyst (ii) (e.g., methylaluminoxane).

[0361] Polyethylene polymer

[0362] This disclosure relates to the preparation of polyethylene polymers, and particularly to the preparation of multimodal ethylene homopolymers or copolymers. The density of the multimodal ethylene homopolymers or copolymers can be between 900 and 980 kg / m³. 3 between.

[0363] The polyethylene polymer provided by this method is in the form of polymer powder.

[0364] Preferably, the multimodal ethylene polymer is a copolymer. More preferably, the multimodal polyethylene copolymer is LLDPE. Its density can be 905 to 940 kg / m³. 3 Preferred weight is 910 to 935 kg / m³. 3 More preferably 915 to 930 kg / m 3 Especially 916 to 928 kg / m 3 In one implementation scheme, 910 to 928 kg / m³ 3The preferred range is as follows. The term LLDPE used herein refers to linear low-density polyethylene. LLDPE is preferably multimodal.

[0365] The term "multimodal" includes polymers with a multimodal MFR, and therefore also includes bimodal polymers. The term "multimodal" can also refer to the multimodality of the "comonomer distribution".

[0366] Polymers comprising at least two polyethylene fractions are typically referred to as “multimodal”, meaning they are produced under different polymerization conditions, resulting in different (weight-average) molecular weights and molecular weight distributions. The prefix “multimodal” refers to the number of different polymer fractions present in the polymer. Thus, for example, the term multimodal polymer includes so-called “bimodal” polymers consisting of two fractions. The molecular weight distribution curve (MWD) of a multimodal polymer (e.g., LLDPE) can exhibit two or more maximum values, or be significantly wider than the curve for a single fraction. Typically, the final MWD curve will be broad, skewed, or show shoulders.

[0367] Ideally, the molecular weight distribution curve of the multimodal polymer of the present invention will show two distinct maximum values. Alternatively, the polymer fractions have similar MFRs, and the comonomer content exhibits a bimodal distribution. Polymers comprising at least two polyethylene fractions are also referred to as “multimodal”, said at least two polyethylene fractions being produced under different polymerization conditions, resulting in different comonomer contents in these fractions.

[0368] For example, if a polymer is produced using a continuous, multi-stage process, utilizing reactors in series and employing different conditions in each reactor, the polymer fractions produced in each reactor will each have their own molecular weight distribution and weight-average molecular weight. When recording the molecular weight distribution curves of such a polymer, superimposing these individual curves onto the molecular weight distribution curve of the overall polymer product typically produces a curve with two or more distinct maximum values.

[0369] In any multimodal polymer, a lower molecular weight component (LMW) and a higher molecular weight component (HMW) can be present. The LMW component has a lower molecular weight compared to the higher molecular weight component. This difference is preferably at least 5000 g / mol.

[0370] The multimodal polyethylene polymer used in this invention preferably contains at least one C 4-10 Comonomer. The comonomer may be present in the HMW component (or the second component) or the LMW component (or the first component) or both. From this point onward, the term LMW / HMW component will be used, but the described embodiments apply to the first and second components, respectively.

[0371] Preferably, the HMW component contains at least one C 4-10 Comonomer. The LMW component may be an ethylene homopolymer or may also include at least one C 4-10 Comonomer. In one embodiment, the multimodal polyethylene polymer comprises a single comonomer. In a preferred embodiment, the multimodal polyethylene polymer comprises at least two, for example, exactly two C... 4-10 Comonomer.

[0372] In one embodiment, the multimodal polyethylene polymer is a terpolymer and contains at least two C2C4 compounds. 4-10 Comonomer. In this case, the HMW component can be a copolymer component or a terpolymer component, and the lower molecular weight (LMW) component can be an ethylene homopolymer component or a copolymer component. Alternatively, both the LMW and HMW components can be copolymers, such that at least two C... 4-10 Comonomer.

[0373] Therefore, multimodal polyethylene polymers may contain HMW components derived from ethylene and at least two other C464 components. 4-10 α-olefin monomers (e.g., 1-butene) and a C 6-10 A multimodal polyethylene polymer of repeating units of α-olefin monomers. Ethylene preferably forms the majority of the LMW or HMW component. In the most preferred embodiment, the LMW component may comprise an ethylene-1-butene copolymer and the HMW component may comprise an ethylene-1-hexene copolymer.

[0374] The total monomer content in the multimodal polyethylene polymer can be, for example, 0.2 to 14.0 mol%, preferably 0.3 to 12 mol%, more preferably 0.5 to 10.0 mol%, and most preferably 0.6 to 8.5 mol%.

[0375] The amount of 1-butene present can be from 0.05 to 6.0 mol%, for example, from 0.1 to 5 mol%, more preferably from 0.15 to 4.5 mol%, and most preferably from 0.2 to 4 mol%.

[0376] C 6-10 The amount of α-olefin present can be from 0.2 to 6 mol%, preferably from 0.3 to 5.5 mol%, more preferably from 0.4 to 4.5 mol%.

[0377] Preferably, the LMW component has a lower amount of comonomer (mol%) than the HMW component. For example, the LMW component preferably has 0.05 to 0.9 mol% of 1-butene as the comonomer, more preferably 0.1 to 0.8 mol%, while the HMW component (B) preferably has 1.0 to 8.0 mol% of 1-hexene as the comonomer, more preferably 1.2 to 7.5 mol%.

[0378] If necessary, the comonomer content (mol%) in the HMW component = (comonomer content (mol%) in the final product – (weight fraction of LMW component * comonomer content (mol%) in LMW component)) / (weight fraction of HMW component).

[0379] Therefore, multimodal polyethylene copolymers can be formed from ethylene and at least one of 1-butene, 1-hexene, or 1-octene. The multimodal polyethylene polymer can be an ethylene-butene-hexene terpolymer, for example, wherein the HMW component is an ethylene-butene-hexene terpolymer and the LMW is an ethylene homopolymer component. Terpolymers of ethylene with 1-butene and 1-octene comonomers, or terpolymers of ethylene with 1-octene and 1-hexene comonomers, are also envisioned.

[0380] In another embodiment, the multimodal polyethylene copolymer may include two polyethylene copolymers, such as two ethylene-butene copolymers or one ethylene-butene copolymer (e.g., as an LMW component) and one ethylene-hexene copolymer (e.g., as an HMW component). The polyethylene copolymer component and the ethylene terpolymer component may also be combined, such as an ethylene-butene copolymer (e.g., as an LMW component) and an ethylene-butene-hexene terpolymer (e.g., as an HMW component).

[0381] The LMW component of the multimodal polyethylene polymer can have an MFR2 of 0.5 to 3000 g / 10 min, more preferably 1.0 to 1000 g / 10 min. In some embodiments, the MFR2 of the LMW component can be 50 to 3000 g / 10 min, more preferably 100 to 1000 g / 10 min, for example, when the target is a cast film. In some embodiments, the MFR2 of the LMW component can be 0.5 to 50 g / 10 min, more preferably 1.0 to 10 g / 10 min, preferably 1.5 to 9.0 g / 10 min, and more preferably 2.0 to 8.5 g / 10 min. The target is a blown film.

[0382] The molecular weight (Mw) of the low molecular weight component should preferably be between 20,000 and 180,000, for example, between 40,000 and 160,000.

[0383] Its density can be at least 925 kg / m³ 3 For example, at least 940 kg / m 3 930 to 950 kg / m 3 Preferred weight is 935 to 945 kg / m³. 3 Density within the range is possible.

[0384] The HMW component of the multimodal polyethylene polymer can, for example, have an MFR2 of less than 1 g / 10 min, such as 0.2 to 0.9 g / 10 min, preferably 0.3 to 0.8 g / 10 min, and more preferably 0.4 to 0.7 g / 10 min. Its density can be less than 915 kg / m³. 3 For example, less than 910 kg / m 3 Preferably less than 905 kg / m 3 The Mw of the higher molecular weight component can be from 70,000 to 1,000,000, preferably from 100,000 to 500,000.

[0385] The LMW component can form 30 to 70 wt% of the multimodal polyethylene polymer, for example 38 to 62 wt%, especially 45 to 55 wt%.

[0386] The HMW component can form 30 to 70 wt% of the multimodal polyethylene polymer, for example 38 to 62 wt%, especially 45 to 55 wt%.

[0387] In one embodiment, there are 40 to 45 wt% LMW component and 60 to 55 wt% HMW component.

[0388] In one embodiment, the polyethylene polymer consists of HMW and LMW components as the sole polymer components.

[0389] The multimodal polyethylene polymer of the present invention can have an MFR2 of 0.01 to 50 g / 10 min, preferably 0.05 to 25 g / 10 min, and especially 0.1 to 10 g / 10 min.

[0390] The multi-peak polyethylene polymer of the present invention can have a content of 900 to 960 kg / m³. 3 Preferred weight is 905 to 940 kg / m³. 3 Especially 910 to 935 kg / m 3 The density.

[0391] The molecular weight distribution (MWD, Mw / Mn) of the polyethylene terpolymer of the present invention is in the range of 2.0 to 15.0, preferably in the range of 2.2 to 10.0, and more preferably in the range of 2.4 to 4.6.

[0392] Multimodal polyethylene polymers can be produced as described herein. Preferably, the multimodal polymer is prepared in at least two stages of polymerization using, for example, two slurry reactors or two gas-phase reactors or any combination thereof, in any order. However, it is preferred to prepare the multimodal polymer using slurry polymerization, for example in two circulating reactors connected in series, followed by gas-phase polymerization in a gas-phase reactor.

[0393] Preferably, the lower molecular weight polymer fraction is produced in a continuously operating tandem circulating reactor, wherein ethylene and any comonomer are polymerized in the presence of a polymerization catalyst and chain transfer agent, such as hydrogen, as described above. The diluent is typically an inert aliphatic hydrocarbon, preferably isobutane or propane.

[0394] The same catalyst can then be used to form higher molecular weight components in a gas-phase reactor.

[0395] Further polymerization steps, such as further gas-phase steps, can also be used.

[0396] It is generally preferred to remove the reactants from the previous polymerization stage from the polymer before introducing it into subsequent polymerization stages. This is preferably done when transferring the polymer from one polymerization stage to another.

[0397] When a higher molecular weight component is the second component in a multi-stage polymerization process, its properties cannot be directly measured. However, those skilled in the art can use... The equation determines the density, MFR2, etc. of higher molecular weight components. The Polymer Processing Society, Europe / Africa Region Meeting, Gothenburg, Sweden, August 19-21, 1997):

[0398] According to the above In the equation (eq.3), for MFR2, a = 5.2 and b = 0.7. Furthermore, w is the weight fraction of other ethylene polymer components (e.g., component (A)) with higher MFRs. Therefore, the LMW component can be considered as component 1, and the HMW component can be considered as component 2. MIb is the MFR2 of the final polyethylene.

[0399] The polymers prepared in the method of this invention can be used in a variety of applications, such as films, for example blown or cast films. They can also be used in molding applications. Example

[0400] Chemicals and raw materials used in the experiment

[0401] Methylaluminoxane was obtained from Lannxess (Axion CA 1330) as a 30 wt% MAO toluene solution.

[0402] The racemic-dimethylsilanediylbis{2-(5-(trimethylsilyl)furan-2-yl)-4,5-dimethylcyclopentadien-1-yl}zirconium dichloride was purchased from a commercial source.

[0403] Comparative Example 1

[0404] The pretreated silica was commercially synthesized amorphous silica ES757 obtained from PQ Corp. Pretreatment involved commercial calcination of the silica at 600°C using conventional PO catalyst technology.

[0405] Catalyst analysis and characterization

[0406] The Al and Zr contents of the solid catalyst components were determined by ICP-OES.

[0407] In a glove box, an equal amount of catalyst (approximately 40 mg) was weighed into a glass weighing dish using an analytical balance. The sample was then placed in a steel secondary container with an air inlet and exposed to air overnight. The contents of the dish were then rinsed into a 20 mL Xpress microwave-safe container using 5 mL of concentrated nitric acid (65%). The sample was then subjected to microwave-assisted acid digestion using a MARS 6 laboratory microwave apparatus, with the temperature increased to 150 °C over 20 minutes and maintained at 150 °C for 35 minutes. The digested sample was cooled to room temperature and then transferred to a 100 mL plastic volumetric flask. A standard solution containing 1000 mg / L yttrium (0.4 mL) was added. The flask was then filled with distilled water and agitated. The solution was filtered through a 0.45 μm nylon syringe filter and analyzed using a Thermo iCAP 6300 ICP-OES and iTEVA software.

[0408] The instrument was calibrated for Al and Zr using a blank (5% HNO3 solution, prepared with concentrated nitric acid) and six standard solutions (0.005 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L, and 100 mg / L Al and Zr solutions). The solutions contained 5% HNO3 (from concentrated nitric acid) and 4 mg / L Y standard in distilled water. Plastic volumetric flasks were used. Curve fitting and 1 / concentration weighting were used for the calibration curve. Prior to analysis, the calibration was validated and adjusted using a blank and 10 mg / L Al and Zr standards (containing 4 mg / L Y and 5% HNO3, prepared with concentrated nitric acid in distilled water) (instrument reslope function). Quality control samples (QC: 1 mg / L Al; 2 mg / L Zr and 4 mg / L Y, dissolved in 5% HNO3, prepared with concentrated nitric acid in distilled water) were used to confirm the reslope. QC samples were also run at the end of the scheduled analysis.

[0409] Zr content was monitored using the 339.198 nm line. Al content was monitored using the 394.401 nm line. Y at 371.030 nm was used as an internal standard. The reported values ​​of the original catalyst samples were calculated using the original mass and dilution volume of the aliquots.

[0410] Compressive strength

[0411] The crushing strength of the material in this embodiment was determined using a Shimadzu MCT-510 micro-compression tester. The sample material was dispersed on a lower compression plate, and the separated particles were located and measured using an optical microscope. The particle diameter was measured using microscope software. Selected sample particles were compressed with progressively increasing loading forces until the particles fractured or the set maximum force was reached. The crushing strength of the material was determined by the maximum compressive load at the particle fracture point and the particle diameter. Measurements were performed under inert conditions, with a loading rate of 0.4462 mN / sec and a maximum load of 40 mN. The crushing strength of 10 randomly selected particles was measured, and the average value after removing statistical outliers was taken as the compressive strength of the catalyst.

[0412] Use commercial statistical analysis software (such as MiniTab or Origin) to perform Weibull distribution analysis on individual particle data.

[0413] Particle size distribution of catalyst component powder

[0414] The particle size distribution of the catalyst components was measured using a Malvern Mastersizer 3000 laser diffraction particle size analyzer. Sample dispersion: dry powder.

[0415] Polymer analysis and characterization

[0416] Bulk density

[0417] The bulk density of polymer powder can be determined according to standard methods such as ISO 60:1977 or ASTM D1895-17.

[0418] MFR

[0419] Melt flow rate (MFR) is determined according to ISO 1133 and expressed in g / 10 min. MFR is an indicator of a polymer's flowability and processing properties. A higher melt flow rate generally corresponds to a lower polymer viscosity. The MFR2 for polypropylene was determined at 230°C and a load of 2.16 kg, the MFR5 for polyethylene was measured at 190°C and a load of 5 kg, and the MFR2 for polyethylene was measured at 190°C and a load of 2.16 kg.

[0420] density

[0421] The density of the polymer was measured according to ISO 1183-2 / 1872-2B.

[0422] Particle size distribution

[0423] The particle size distribution of the polymer powder was measured using a Coulter LS200 particle size analyzer according to ISO 13320-1. This instrument is capable of measuring particle size distributions ranging from 0.4 to 2000 μm. The method used is laser diffraction, where a laser beam is directed at the sample traveling in a flow-through cuvette. Heptane was used as the sample fluid. The polymer sample was first pretreated to screen out particles larger than 2 mm. The screened sample was then mixed with isopropanol and placed in an ultrasonic apparatus to separate the particles. The pretreated sample was then placed in a sample cell for analysis.

[0424] The mean, median (D50), and mode of the particle size distribution were calculated from the experimental data using standard statistical distribution analysis methods.

[0425] The log-normal scale and location parameters of the polymer powder particle size distribution are determined by fitting a model log-normal distribution to the experimental distribution, and the probability density function of the distribution is calculated using the following formula:

[0426]

[0427] Where σ is the scale parameter, and μ is the location parameter of the log-normal distribution. The case where μ = 0 and σ = 1 is called the standard log-normal distribution.

[0428] GPC

[0429] The average molecular weight (Mz, Mw, and Mn), molecular weight distribution (MWD), and its width, described by the polydispersity index (PDI), PDI = Mw / Mn (where Mn is the number-average molecular weight and Mw is the weight-average molecular weight), are determined by gel permeation chromatography (GPC) according to ISO 16014-1:2003, ISO 16014-2:2003, ISO 16014-4:2003, and ASTM D 6474-12 using the following formula:

[0430]

[0431]

[0432]

[0433] For a constant elution volume interval ΔV i A i and M i These are the peak slice area and the molecular weight (MW) of the polyolefin, respectively, as a function of the elution volume V. i The correlation is given by N, which equals the number of data points obtained from the chromatogram between the integration limits.

[0434] A high-temperature GPC instrument equipped with an infrared (IR) detector (IR4 or IR5, from PolymerChar (Valencia, Spain)) and three Agilent-PLgel Olexis guard columns and one Agilent-PLgel Olexis guard column was used. 1,2,4-trichlorobenzene (TCB) stabilized with 250 mg / L 2,6-di-tert-butyl-4-methylphenol was used as both solvent and mobile phase. The chromatographic system was run at a constant flow rate of 1 mL / min at 160 °C. 200 μL of sample solution was injected for each analysis. Data collection was performed using Agilent Cirrus software version 3.3 or PolymerChar GPC-IR control software.

[0435] The column assembly was calibrated using a universal calibration (according to ISO 16014-2:2003) and 19 narrow MWD polystyrene (PS) standards, ranging from 0.5 kg / mol to 11,500 kg / mol. PS standards were dissolved at room temperature for several hours. The conversion of polystyrene peak molecular weight to polyolefin molecular weight was performed using the Mark Houwink equation and the following Mark Houwink constant:

[0436] K PS =19x10 -3 mL / g, α PS =0.655

[0437] K PE =39x10 -3 mL / g, α PE =0.725

[0438] K PP =19x10 -3 mL / g, α PP =0.725

[0439] Third-order polynomial fitting was used to fit the calibration data.

[0440] All samples were prepared at concentrations ranging from 0.5 to 1 mg / mL and dissolved by gentle shaking continuously at 160°C for 2.5 hours for PP or 3 hours for PE.

[0441] Comparative Catalyst Example 2 (CE2) – Representative Description of a Two-Step Manufacturing Process

[0442] Preparation of SiO2 / methylaluminoxane:

[0443] Add SiO2 (5.0 kg) from the feed tank and inertize it in the reactor to reduce the O2 level to below 2 ppm.

[0444] 21.6 kg of toluene was added to the reactor. The mixture was stirred (40 rpm) for 15 minutes before starting the methylaluminoxane feed. Over 85 minutes, 30 wt% methylaluminoxane (8.53 kg) was added from the feed vessel using a balance. After the methylaluminoxane feed was complete, the methylaluminoxane in the feed line was flushed into the reactor with 1 kg of toluene. The reaction mixture was heated to 90°C. When the internal temperature reached 85°C, the temperature was set to 95°C (oil circulation). After heating for 135 minutes, the reaction time was 120 minutes. Next, the slurry was allowed to settle for 10 minutes and the mother liquor was filtered off. The remaining solids were washed twice with toluene (21.6 kg). The target temperature for the first toluene wash was 90°C for 30 minutes, and the target temperature for the second toluene wash was 60°C. The settling time before filtering the second and third toluene washes was 10 minutes. During the settling of the first toluene wash, the reactor was cooled to 60°C. Finally, the SiO2 treated with methylaluminoxane was dried at 60°C (oil circulation temperature) for 2 hours under a nitrogen flow of 2 kg / h, and then vacuum dried for 6 hours under the same nitrogen flow with stirring at 5 rpm. Samples of the dried SiO2 / methylaluminoxane were taken, and the HC content was measured using a Sartorius moisture analyzer (model MA45) in a glove box via thermogravimetric analysis. The target HC level was less than 3% (actually 1.1%). After drying, the reactor oil circulation temperature was set to 10°C.

[0445] Preparation of metallocene toluene solution:

[0446] Toluene (8.85 kg) was added to another reactor and stirred for 20 minutes at 25°C (oil circulation temperature, stirring at 400 rpm). Metallocene racemic dimethylsilane dimethylbis{2-(5-(trimethylsilyl)furan-2-yl)-4,5-dimethylcyclopentadien-1-yl}zirconium dichloride (0.209 g) was added using a burette, followed by rinsing with toluene (2 L, total toluene 8.4 kg). The reactor stirring speed was changed to 150 rpm for MC feed and then returned to 400 rpm for a reaction time of 3 hours. After the reaction time, the solution was transferred to a feed vessel to feed silica-methylaluminoxane.

[0447] Catalyst preparation:

[0448] The reactor temperature was set to 80°C (oil circulation temperature), and the metallocene solution was added with stirring at 40 rpm. The solution was added through a nozzle over 55 minutes (target 9.06 kg, actual 8.8 kg), followed by stirring at 25°C for 60 minutes. The resulting catalyst was stabilized at 25°C for 12 hours. Finally, the catalyst was dried at 60°C (oil circulation temperature) for 2 hours under a nitrogen flow of 2 kg / h, followed by vacuum drying for 7 hours under the same nitrogen flow with stirring at 5 rpm. Samples of the dried catalyst were taken, and the HC content was measured using thermogravimetric analysis in a glove box using a Sartorius moisture analyzer (model MA45). The target HC level was less than 3%.

[0449] Comparative catalyst Example 3 (CE3)

[0450] The preparation method of catalyst CE3 is similar to that of CE5, except that the initial loading of raw materials and method parameters have been modified as shown in Table 1.

[0451] Comparative catalyst Example 4 (CE4)

[0452] CE4 was prepared using the same procedure as CE2, but the method was modified according to Table 2.

[0453] Comparative Catalyst Example 5 (CE5) – A Representative Description of a One-Step Production Process

[0454] SiO2 loading:

[0455] Add 10 kg of silica (PQ Corporation ES757, calcined at 600°C) from the feed tank and inertize it in the reactor until the O2 level is below 2 ppm.

[0456] Preparation of toluene solution of metallocene / methylaluminoxane:

[0457] 30 wt% methylaluminoxane from 14.1 kg of toluene was added from a balance to another reactor, followed by the addition of 4.0 kg of toluene at 25°C (oil circulation temperature) with stirring at 95 rpm. After the addition of toluene, the stirring speed was increased from 95 rpm to 200 rpm for 30 minutes. 477 g of metallocene racemic dimethylsilanediylbis{2-(5-(trimethylsilyl)furan-2-yl)-4,5-dimethylcyclopentadien-1-yl}zirconium dichloride was added from a metal cylinder and then rinsed with 4 kg of toluene (total toluene 8.0 kg). The reactor stirring speed was changed to 95 rpm for MC feed and then returned to 200 rpm for a reaction time of 3 hours. After the reaction time, the methylaluminoxane / tol / MC solution was transferred to a feed vessel.

[0458] Catalyst preparation:

[0459] The reactor temperature was set to 10°C (oil circulation temperature) and stirred at 40 rpm to add methylaluminoxane / tol / MC. The methylaluminoxane / tol / MC solution (target 22.5 kg, actual 22.2 kg) was added over 205 minutes, followed by stirring for 60 minutes (oil circulation temperature set to 25°C). After stirring, the "dry mixture" was stabilized at 25°C (oil circulation temperature) for 12 hours with a stirring speed of 0 rpm. The reactor was rotated 20° (back and forth) and stirred several times at 5 rpm, once per hour.

[0460] After stabilization, the catalyst was dried at 60°C (oil circulation temperature) for 2 hours under a nitrogen flow of 2 kg / h, followed by vacuum drying for 13 hours (with stirring at 5 rpm under the same nitrogen flow). Samples of the dried catalyst were taken, and the HC content was measured using a Sartorius moisture analyzer (model MA45) in a glove box via thermogravimetric analysis. The target HC level was less than 2% (actually 1.3%).

[0461] Catalyst Example 1 (IE1) of the Invention

[0462] The preparation method of catalyst IE1 is similar to that of CE5, except that the initial loading of raw materials and method parameters have been modified as shown in Table 1.

[0463] Catalyst Example 2 (IE2) of the present invention

[0464] The preparation method of catalyst IE2 is similar to that of CE5, except that the initial loading of raw materials and method parameters have been modified as shown in Table 1.

[0465] Catalyst Example 3 (IE3) of the present invention

[0466] The preparation method of catalyst IE3 is similar to that of CE5, except that the initial loading of raw materials and method parameters have been modified as shown in Table 1.

[0467] Catalyst Example 4 (IE4) of the present invention

[0468] The preparation method of catalyst IE4 is similar to that of CE5, except that the initial loading of raw materials and method parameters have been modified as shown in Table 1.

[0469] General Lab-Scale Polymerization Procedure: Single-Peak Copolymerization

[0470] In a 3-liter reactor, 1.5 mL of a 10% heptane solution of triisobutylaluminium was added under nitrogen pressure, followed by 1250 mL of liquid propane at 20°C. The reactor pressure was 8.92 bar. The reactor was then heated to the required prepolymerization temperature of 60°C with a stirring rate of 350 rpm. The pressure in the reactor was 21.95 bar.

[0471] 0.2 bar H2 from a 500 mL container was injected into the feed line. Ethylene (32.6 g) and 1-hexene (5.0 mL / 3.4 g), corresponding to a pressure differential of 3.70 bar, were added to the reactor through the H2-containing line. The pressure in the reactor was increased to 25.65 bar.

[0472] The required amount of catalyst (typically 25 to 35 mg) is weighed into the catalyst feeder inside the glove box. The catalyst feeder is connected to the polymerization reactor, and air in the pipeline is removed by three repeated vacuum and nitrogen-filled cycles. After the pipeline is inertized, the catalyst is flushed into the reactor with 100 mL of propane, and the stirring speed is increased to 550 rpm. The pressure in the reactor is approximately 25.61 bar.

[0473] The prepolymerization step continues until 2 to 5% prepolymer material (roughly equivalent to 2 to 5 g of C2 consumption) is formed at 60°C by maintaining a constant pressure through the supply of ethylene using a flow meter. Typically, it takes about 40 minutes to reach the desired degree of prepolymerization.

[0474] The temperature of the polymerization reactor rose to 85°C, resulting in a reactor pressure of 40.4 bar.

[0475] Inject 0.2 bar H2 from a 500 mL container into the pipeline. Add 62.5 g of ethylene and 10.0 mL of 1-hexene (6.7 g) corresponding to a pressure differential of 6.70 bar into the reactor through the H2-containing pipeline.

[0476] For the slurry polymerization step, the reactor was stirred at 85°C for 60 minutes. Ethylene was supplied via a flow meter to maintain constant pressure. After 60 minutes of polymerization, the reaction was stopped by reducing the stirring speed to 150 rpm, venting the reactor, and lowering the temperature to 60°C. To remove hydrocarbon residues (before opening), the reactor was flushed 10 times with nitrogen pressure at 1 bar. Before opening the reactor, it was cooled to 20°C.

[0477] Comparative Method Example 1 (CPE1 / CE5)

[0478] LLDPE films were produced using a single-point catalyst (CE5) with an initial size (D50) of 25 μm. The catalyst was first prepolymerized in a prepolymerization reactor at T = 50 °C and P = 65 barg. More specifically, 900 kg / h of ethylene, 95 kg / ton of 1-butene, 0.27 kg / ton of hydrogen, and 6.50 tons / h of propane (diluent) were fed into the prepolymerization reactor, with an average residence time of 30 minutes. The product was then transferred to a container with a volume of 80 m³. 3 A separate circulating reactor configuration was used. Ethylene (C2), propane (diluent), 1-butene (C4), and hydrogen (H2) were fed into the reactor under polymerization conditions of T = 85°C, P = 64 barg, and an average residence time of 1.0 h. The molar ratios of H2 / C2 and C4 / C2 were 2 mol / kmol and 100 mol / kmol, respectively, with a total production rate of 1.1 kg / gcat. The material was then flash-distilled in a high-pressure separator, the operating pressure of which was selected to be 2 barg, and the estimated residence time to be 5 minutes. Subsequently, the polymer particles were transferred to a reactor with a total volume of 350 m³. 3 In a gas-phase reactor (including the decomposition zone), the reactor operates at a total pressure of 20 barg and a temperature of 75°C, with a gas phase composition of 52.5% mol propane, 10% mol nitrogen, 32.5% mol ethylene, 5% mol C6, and H2 / C2 = 0.5 mol / kmol. The total residence time in the GPR is 3 hours. The apparent gas velocity in the gas-phase reactor is chosen to be 0.45 m / s.

[0479] A cyclone separator (potentially overcoming this) is placed at the outlet of the decommissioning zone (recirculated gas pipeline) to collect entrained particles (estimated particle carrying capacity) and prevent small particles from passing through the gas compressor and heat exchanger.

[0480] The catalyst productivity in the GPR is 1.5 kg / gcat (3-day average). The production fraction is 58%. Based on the measured ΔP value of the entire fluidized bed (i.e., ΔP = rho * g * hbed), the measured fluidized bed bulk density is 260 kg / m³. 3 The catalyst particles used had i) a Weibull modulus to size parameter ratio of 0.55 and ii) a Weibull modulus to size parameter product of 22. The solids carrying capacity was measured to be 160 kg / h. Furthermore, significant agglomeration issues emerged after 7 days of operation, leading to serious operability problems. Due to agglomeration and caking issues, GPR operation was interrupted and ultimately shut down after 10 days of operation.

[0481] Example 1 of the method of the present invention (IPE1 / IE2)

[0482] The procedure of Example 1 was repeated, except that a different unit-point catalyst (IE2) with an initial size d50 of 25 μm was used. The productivity was 1.5 kg / gcat, while the catalyst productivity in GPR was 1.9 kg / gcat. The production split was 58%. Based on the ΔP measurement of the entire fluidized bed, the measured fluidized bed bulk density was 380 kg / m³. 3 The catalyst particles used have i) a Weibull modulus to scale parameter ratio of 0.49 and ii) a Weibull modulus to scale parameter product of 47. The solids carrying capacity is measured to be 5 kg / h. The GPR has been operating smoothly for 20 days.

[0483] Example 2 of the method of the present invention (IPE2 / IE3)

[0484] The procedure of Example 1 was repeated, except that a different unit-point catalyst (IE3) with an initial size d50 of 25 μm was used. The productivity was 1.5 kg / gcat, while the catalyst productivity in GPR was 2.1 kg / gcat. The production split was 58%. Based on the ΔP measurement of the entire fluidized bed, the measured fluidized bed bulk density was 390 kg / m³. 3 The catalyst particles used have i) a Weibull modulus to size parameter ratio of 0.43 and ii) a Weibull modulus to size parameter product of 61. The solids carrying capacity was measured to be 4.0 kg / h. The GPR has been operating smoothly for 20 days.

[0485] Table 1 – Examples of one-step process catalysts

[0486]

[0487]

[0488] Table 2 – Examples of Two-Step Catalyst Processes

[0489]

[0490]

[0491] Table 3A – Analysis and Characterization

[0492]

[0493] Table 3B – Analysis and Characterization

[0494]

[0495]

[0496] Table 4 – Aggregated Data

[0497]

[0498] Table 5 – Aggregation using Continuous Methods

[0499]

[0500]

Claims

1. A method for polymerizing olefins, the method comprising: Ethylene may be polymerized, optionally in the presence of at least one other α-olefin comonomer, in the presence of a single-point polymerization catalyst, to produce polymer components, polyethylene polymers, or polyethylene copolymers. The unit site polymerization catalysts include (i) transition metal complexes; (ii) co-catalysts; and optionally (iii) supports; and Its features are: The product of (Weibull modulus) and (scale parameter) is equal to or greater than 40 MPa, and the ratio of (Weibull modulus) to (scale parameter) is equal to or less than 0.50 MPa. -1 The Weibull modulus and scale parameters were determined by Weibull analysis of the compressive strength of the catalyst particles. Wherein, when measured at a load rate of 0.4462 mN / sec and a maximum load of 40 mN, the compressive strength is the average of the crushing strengths of 10 randomly selected particles, wherein the crushing strength is determined by the maximum compressive load at the particle fracture point and the particle diameter; and The transition metal complex mentioned therein is a metallocene complex of formula (I). (I) Each X is a σ donor ligand; Each Het is independently a monocyclic or polycyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S; L is a divalent bridge based on carbon, silicon, or germanium, in which one or two framework atoms connect to the ligand; M is Ti, Zr, or Hf; Each R1 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy, benzyl, O-benzyl, optionally with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl or optionally substituted with 1 to 3 carbons 1-6 Alkyl-substituted O-phenyl; Each R3 is the same or different, for C 1-10 Alkyl, C 1-10 Alkyl groups or optionally alkoxy groups with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl; Each n is between 0 and 3; Each R2 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy or -Si(R)3 group; Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and Each p is between 0 and 3.

2. A method for polymerizing olefins in a multi-stage polymerization configuration, the method comprising: a) In the first polymerization step, ethylene is optionally polymerized in the presence of at least one other α-olefin comonomer and a single-point polymerization catalyst to form the first polymer component (A); and b) In the second polymerization step, in the presence of the first polymer component (A) from step a), optionally in the presence of at least one other α-olefin comonomer, an olefin monomer is polymerized to form the second polymer component (B). To produce polyethylene polymers or polyethylene copolymers, The unit site polymerization catalysts include (i) transition metal complexes; (ii) co-catalysts; and optionally (iii) supports; and Its features are: The product of (Weibull modulus) and (scale parameter) is equal to or greater than 40 MPa, and the ratio of (Weibull modulus) to (scale parameter) is equal to or less than 0.50 MPa. -1 The Weibull modulus and size parameters were determined by Weibull analysis of the compressive strength of the catalyst particles. The compressive strength was the average of the crushing strengths of 10 randomly selected particles, measured at a loading rate of 0.4462 mN / sec and a maximum load of 40 mN. The crushing strength was determined by the maximum compressive load at the particle fracture point and the particle diameter. The transition metal complex mentioned therein is a metallocene complex of formula (I). (I) Each X is a σ donor ligand; Each Het is independently a monocyclic or polycyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S; L is a divalent bridge based on carbon, silicon, or germanium, in which one or two framework atoms connect to the ligand; M is Ti, Zr, or Hf; Each R1 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy, benzyl, O-benzyl, optionally with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl or optionally substituted with 1 to 3 carbons 1-6 Alkyl-substituted O-phenyl; Each R3 is the same or different, for C 1-10 Alkyl, C 1-10 Alkyl groups or optionally alkoxy groups with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl; Each n is between 0 and 3; Each R2 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy or -Si(R)3 group; Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and Each p is between 0 and 3.

3. The method as described in claim 2, wherein, In step (a), the at least one other α-olefin comonomer is C4-C. 10 α-olefin comonomers; and / or wherein polymerization occurs in a slurry phase.

4. The method as described in claim 2 or 3, wherein, In step (b), the at least one other α-olefin comonomer is C4-C. 10 α-olefin comonomers; and / or wherein polymerization occurs in the gas phase.

5. The method of claim 1 or 2, wherein the ratio of the co-catalyst (ii) to the transition metal complex (i) is greater than 50 mol / mol.

6. The method of claim 1 or 2, wherein the metallocene complex is as shown in formula (X). (X) Each X is a σ donor ligand; L is a divalent bridge based on carbon, silicon, or germanium, in which one or two framework atoms connect to the ligand; M is Ti, Zr, or Hf; Each Het is independently a monocyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S; Each R1 is the same or different, for C 1-10 alkyl; Each n is between 1 and 3; Each R2 may be the same or different, and is a -Si(RaRbRc) group; Ra is C 1-6 alkyl; Rb is C 1-6 alkyl; Rc is randomly selected from 1 to 3 Cs. 1-6 Alkyl-substituted phenyl; and Each p is between 1 and 3.

7. The method of claim 1 or 2, wherein the metallocene complex (i) is as shown in formula (XII'). (XII'') Each X is a σ donor ligand; L represents the (RdRe)Si group; Rd is C 1-10 alkyl; Re is C 2-10 alkenyl; Each R1 is the same or different, for C 1-10 alkyl; Each n is between 1 and 3; Each R2 may be the same or different, and is a -Si(R)3 group; Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl groups.

8. The method of claim 2, wherein step a) is carried out in at least two slurry reactors.

9. The method of claim 2, wherein step a) is carried out in at least three slurry reactors.

10. A single-point polymerization catalyst, comprising: (i) Transition metal complexes; (ii) co-catalysts; and Optional (iii) carrier; The catalyst for unit-point polymerization is characterized by: the product of (Weibull modulus) x (scale parameter) being equal to or greater than 40 MPa, and the ratio of (Weibull modulus) / (scale parameter) being equal to or less than 0.50 MPa. -1 The Weibull modulus and scale parameters were determined by Weibull analysis of the compressive strength of the catalyst particles. in, When measured at a load rate of 0.4462 mN / sec and a maximum load of 40 mN, the compressive strength is the average of the crushing strengths of 10 randomly selected particles, wherein the crushing strength is determined by the maximum compressive load at the particle fracture point and the particle diameter; and The transition metal complex mentioned therein is a metallocene complex of formula (I). (I) Each X is a σ donor ligand; Each Het is independently a monocyclic or polycyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S; L is a divalent bridge based on carbon, silicon, or germanium, in which one or two framework atoms connect to the ligand; M is Ti, Zr, or Hf; Each R1 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy, benzyl, O-benzyl, optionally with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl or optionally substituted with 1 to 3 carbons 1-6 Alkyl-substituted O-phenyl; Each R3 is the same or different, for C 1-10 Alkyl, C 1-10 Alkyl groups or optionally alkoxy groups with 1 to 3 carbon atoms 1-6 Alkyl-substituted phenyl; Each n is between 0 and 3; Each R2 is the same or different, for C 1-10 Alkyl, C 1-10 Alkoxy or -Si(R)3 group; Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl; and Each p is between 0 and 3.

11. The unit site polymerization catalyst of claim 10, wherein the support is a silica support.

12. The unit site polymerization catalyst of claim 10, wherein the ratio of the co-catalyst (ii) to the transition metal complex (i) is greater than 50 mol / mol.

13. The unit site polymerization catalyst according to any one of claims 10 to 12, wherein the co-catalyst (ii) is as shown in formula (ii-I): (ii-I) Where n is between 6 and 20, and R is C 1-10 Alkyl or C 3-10 cycloalkyl, C 7-12 Aryl or alkylaryl and / or phenyl or naphthyl.

14. The unit site polymerization catalyst as described in claim 13, wherein, The co-catalyst (ii) is methylaluminoxane.

15. The unit site polymerization catalyst according to any one of claims 10 to 12, wherein the transition metal complex is a metallocene complex of formula (X). (X) Each X is a σ donor ligand; L is a divalent bridge based on carbon, silicon, or germanium, in which one or two framework atoms connect to the ligand; M is Ti, Zr, or Hf; Each Het is independently a monocyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from O, N or S; Each R1 is the same or different, for C 1-10 alkyl; Each n is between 1 and 3; Each R2 may be the same or different, and is a -Si(RaRbRc) group; Ra is C 1-6 alkyl; Rb is C 1-6 alkyl; Rc is randomly selected from 1 to 3 Cs. 1-6 Alkyl-substituted phenyl; and Each p is between 1 and 3.

16. The single-site polymerization catalyst according to any one of claims 10 to 12, wherein the metallocene complex (i) is as shown in formula (XII'). (XII'') Each X is a σ donor ligand; L represents the (RdRe)Si group; Rd is C 1-10 alkyl; Re is C 2-10 alkenyl; Each R1 is the same or different, for C 1-10 alkyl; Each n is between 1 and 3; Each R2 may be the same or different, and is a -Si(R)3 group; Each R is C 1-10 Alkyl groups or optionally 1 to 3 carbons 1-6 Alkyl-substituted phenyl groups.

17. Use of the unit point polymerization catalyst according to any one of claims 10 to 12 in the preparation of polyethylene polymer components, polyethylene polymers or polyethylene copolymers.

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