Process for polymerizing olefins having narrow particle size distribution

Abstract

The present disclosure relates to a process for polymerizing olefins, comprising polymerizing ethylene in the presence of a single-site polymerization catalyst, optionally in the presence of at least one other alpha-olefin comonomer, to produce a polymer component, a polyethylene polymer or polyethylene copolymer, wherein the polyethylene polymer or polyethylene copolymer has a particle size distribution described by a log-normal distribution with a scale parameter of the resulting polyethylene polymer powder or polyethylene copolymer powder of less than 0.5, preferably less than 0.45, in particular between 0.1 and 0.45, more preferably between 0.15 and 0.4. The present disclosure further relates to a single-site polymerization catalyst as described above, comprising: (i) a transition metal complex; (ii) a cocatalyst; and, optionally, (iii) a support, preferably a silica support, wherein the single-site polymerization catalyst has a compressive strength of at least 5 MPa, preferably at least 5.5 MPa, in particular between 6 and 25 MPa, more preferably between 7 and 20 MPa, even more preferably between 7 and 15 MPa. The present disclosure further relates to the use of a single-site polymerization catalyst in the preparation of a polyethylene polymer component, a polyethylene polymer or a polyethylene copolymer, and to a polyethylene polymer or polyethylene copolymer in powder form, preferably a polyethylene polymer or polyethylene copolymer obtained by the process, having a particle size distribution described by a log-normal distribution with a scale parameter of less than 0.5, preferably less than 0.45, in particular between 0.1 and 0.45, more preferably between 0.15 and 0.4.

Description

[Technical field]

[0001] The present disclosure relates to a process for polymerizing olefins to produce polyethylene polymers and copolymers using a single-site polymerization catalyst. In particular, the present disclosure relates to polymerizing olefins to produce polyethylene polymers or copolymers having a narrow particle size distribution, especially in a multi-stage polymerization process configuration. The present disclosure further relates to the single-site polymerization catalyst. The present disclosure also relates to a method of using said single-site polymerization catalyst in the preparation of polyethylene polymer components, polyethylene polymers or polyethylene copolymers having a narrow particle size distribution. [Background technology]

[0002] Multi-stage polyolefin production processes (e.g., Borstar PE, PP, Spheripol PP) consist of multi-stage reactor configurations to provide multimodal capabilities to easily achieve processing of resins with desired mechanical properties. Such processes combine multiple slurry loop reactors in series, followed by a gas phase reactor, to produce a full range of polyolefin grades.

[0003] A key feature of the aforementioned materials produced in a multi-stage olefin polymerization process is to achieve a desired production split to meet the requirements of product multimodal design without sacrificing the desired production throughput. In general, if the production split of a GPR can be increased for a given production throughput, the product portfolio can be significantly expanded / enhanced.

[0004] In many cases, the limiting step in achieving the target product split in a multi-stage polyethylene process reactor configuration comes from gas phase reactor operability challenges (e.g. poor hydrodynamic phenomena, proper gas-solid pattern, etc.) strongly associated with the particle size distribution characteristics / characteristics and bulk density of the particulate matter (which is also related to the fluidized bulk density). It is well known that fluidizing polymer PE particles with a wide particle size distribution and / or low fluidized bulk density value leads to the segregation of the particles and particle entrainment phenomena (also known as solids carryover), which not only limits the operability and performance of the GPR but also results in productivity limitations and very high risks of reactor shutdown.

[0005] Many challenges have been observed in achieving the targeted loop / GPR split and good operability in GPR when single-site catalysts are used. The broad particle size distribution of polymer particles produced in GPR, combined with the relatively low fluidized bulk density, not only poses challenges to operability in GPR, but also makes it difficult to achieve the desired product split so that the targeted product fleet is produced. Summary of the Invention [Problem to be solved by the invention]

[0006] It is an object of the present disclosure to provide a polyethylene polymerization process, typically consisting of multiple reactors connected in series, in particular a multi-stage polymerization process, and a specific catalyst system for use in said process, so as to alleviate the above-mentioned drawbacks.

[0007] The object of the present disclosure is achieved by a specific single-site polymerization catalyst system, the use of said catalyst system, a process for polymerizing olefins, and an ethylene (co)polymer, which are characterized by the features set forth in the independent claims. Preferred embodiments of the present disclosure are disclosed in the dependent claims. [Means for solving the problem]

[0008] The present disclosure is based on the idea of ​​producing a polyethylene polymer or polyethylene copolymer where the particle size distribution of the resulting polyethylene polymer powder or polyethylene copolymer powder is described by a log-normal distribution with a scale parameter of less than 0.5.

[0009] An advantage of the inventive catalysts and processes of this disclosure is that the use of the inventive single-site catalyst system in polyethylene polymerization, particularly in ethylene multi-stage polymerization processes, eliminates operability issues in GPR related to sheeting, chunking and solids carry over, in addition, it improves GPR product splits and reduces the presence of gels in the final product, which is most important in e.g. film applications.

[0010] Thus, the catalysts and processes of the present invention enable the (co)polymerization of ethylene at high production rates, and the resulting polymer particles exhibit high bulk density.

[0011] The present disclosure relates to a process for polymerizing olefins, the process comprising polymerizing ethylene, optionally together with at least one other alpha-olefin comonomer, preferably C4-C6, in the presence of a single-site polymerization catalyst. 10and polymerizing, preferably in a multi-stage polymerization process configuration, in the presence of an alpha-olefin comonomer to produce a polymer component, to produce a polyethylene polymer or polyethylene copolymer, wherein said polyethylene polymer or polyethylene copolymer has a particle size distribution described by a log-normal distribution with a scale parameter of less than 0.5 for the resulting polyethylene polymer powder or polyethylene copolymer powder.

[0012] In particular, the present disclosure relates to a process for polymerizing olefins to produce a polyethylene polymer or polyethylene copolymer, the process comprising: a) In the first polymerization step, ethylene is optionally polymerized with at least one other alpha-olefin comonomer, preferably C4-C 10 polymerizing, preferably in the slurry phase, an alpha-olefin comonomer in the presence of a single-site polymerization catalyst to form a first polymer component (A); and b) In a second polymerization step, the olefin monomer is polymerized in the presence of said first polymer component (A) of step a), optionally with at least one other alpha-olefin comonomer, preferably C4-C 10 and polymerizing, preferably in the gas phase, in the presence of an alpha-olefin comonomer to form a second polymer component (B). Including, The polyethylene polymer or polyethylene copolymer has a particle size distribution described by a log-normal distribution with a scale parameter of the resulting polyethylene polymer powder or polyethylene copolymer powder of less than 0.5.

[0013] In particular, the present disclosure relates to a process for polymerizing olefins to produce a polyethylene polymer or polyethylene copolymer, the process comprising the steps of: a) In the first polymerization step, ethylene is optionally polymerized with at least one other alpha-olefin comonomer, preferably C4-C 10polymerizing, preferably in the slurry phase, an alpha-olefin comonomer in the presence of a single-site polymerization catalyst to form a first polymer component (A), wherein the polymerization catalyst comprises (i) a metallocene complex of formula (I) [ka] wherein formula (I) is as defined herein. (ii) a cocatalyst comprising an aluminoxane cocatalyst of the following formula (ii-I): [ka] wherein formula (ii-I) is as defined herein. and optionally a further cocatalyst comprising a compound of a Group 13 element; and optionally, (iii) a support; including; b) In a second polymerization step, the olefin monomer is polymerized in the presence of said first polymer component (A) of step a), optionally with at least one other alpha-olefin comonomer, preferably C4-C 10 alpha-olefin comonomer, optionally in the gas phase, to form a second polymer component (B). Including, wherein said polyethylene polymer or said polyethylene copolymer has a particle size distribution described by a log-normal distribution with a scale parameter of the resulting polyethylene polymer powder or polyethylene copolymer powder of less than 0.5.

[0014] The present disclosure also provides (i) a metallocene complex of formula (I) [ka] wherein formula (I) is as defined herein. (ii) a promoter; (iii) Support Including, wherein the single-site polymerization catalyst has a compressive strength of at least 5 MPa, and the ratio of the co-catalyst (ii) to the transition metal complex (i) is preferably greater than 50 mol / mol, preferably from 60 to 200 mol / mol, more preferably from 100 to 160 mol / mol, and even more preferably from 110 to 150 mol / mol; Regarding the above catalyst system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] process

[0016] The present disclosure relates to a method for polymerizing olefins, the method comprising polymerizing ethylene to produce a polyethylene polymer or copolymer, wherein the polyethylene polymer or copolymer has a particle size distribution described by a log-normal distribution with a scale parameter of the resulting polyethylene polymer or polyethylene copolymer powder of less than 0.5. The process typically comprises an optional but preferred prepolymerization step, followed by a first polymerization step and a second polymerization step.

[0017] Preferably the same single-site polymerization catalyst is used in each step and ideally it is transferred sequentially from the prepolymerization to the subsequent polymerization step in a well known manner.

[0018] Generally, the amount of single-site polymerization catalyst used will depend on the nature of the catalyst, the type and conditions of the reactor, and the properties desired in the polymer product. As is well known to those skilled in the art, hydrogen can be used in either reactor to control the molecular weight of the polymer.

[0019] Thus, a method for polymerizing olefins in a plurality of polymerization reactors connected in series comprises: a) In the first polymerization step, ethylene is polymerized in the presence of a single-site polymerization catalyst, optionally with at least one other alpha-olefin comonomer, preferably a C4-C 10polymerizing, preferably in the slurry phase, in the presence of an alpha-olefin comonomer and a polymerization catalyst to form a first polymer component (A); and b) In a second polymerization step, the olefin monomer is polymerized in the presence of the first polymer component (A) of step a), optionally with at least one other alpha-olefin comonomer, preferably a C4-C 10 and polymerizing, preferably in the gas phase, in the presence of an alpha-olefin comonomer to form a second polymer component (B). Includes.

[0020] Preferably, the same polymerization catalyst is used in each step, and ideally it is transferred sequentially from the prepolymerization to the subsequent polymerization steps in a well-known manner. One preferred process configuration is the Borstar 登録商標 Type cascade, especially Borstar 登録商標 2G type cascade, especially Borstar 登録商標 Based on 3G type cascade.

[0021] Prepolymerization process

[0022] A prepolymerization step may be performed before the polymerization step. The purpose of the prepolymerization is to polymerize a small amount of polymer on the catalyst at a low temperature and / or a low monomer concentration. Prepolymerization can improve the performance of the catalyst in the slurry and / or modify the properties of the final polymer.

[0023] The prepolymerization step can be carried out in a slurry or in the gas phase. Preferably, the prepolymerization is carried out in a slurry, preferably in a loop reactor.

[0024] The prepolymerization is then preferably carried out in an inert diluent, preferably a low boiling hydrocarbon having 1-6 carbon atoms or a combination of such hydrocarbons. The temperature in the prepolymerization step is typically 0-90° C., preferably 20-80° C., more preferably 25-70° C. The pressure is not critical and is typically 1-150 bar, preferably 10-100 bar.

[0025] The amount of polymer produced in the optional prepolymerization step counts towards the amount (wt %) of polyethylene polymer component (A).

[0026] If a prepolymerization step is present, the single-site polymerization catalyst is preferably introduced into the prepolymerization step. The reaction product of the prepolymerization step is then preferably introduced into the first reactor.

[0027] Within the scope of the present invention, it is understood that the amount of polymer produced in the prepolymerization is in the range of 1-7% by weight relative to the final multimodal (co)polymer, which can be counted as part of the first polymer component (A) produced in the first polymerization step a).

[0028] First polymerization step a)

[0029] In the present process, the first polymerization step a) comprises the step of polymerizing ethylene monomer and, optionally, at least one olefin comonomer, preferably C4-C 10 The process includes polymerizing an alpha-olefin comonomer.

[0030] In one embodiment, the first polymerization step comprises polymerizing ethylene to produce an ethylene homopolymer.

[0031] In another embodiment, the first polymerization step comprises polymerizing ethylene and at least one olefin comonomer to produce an ethylene copolymer.

[0032] The polymerization in the first polymerization step a) is carried out in the presence of a single-site polymerization catalyst, as described in more detail below.

[0033] The first polymerization step can be carried out in any suitable reactor or series of reactors. The first polymerization step is carried out in one or more slurry polymerization reactors. Preferably, the first polymerization step is carried out in one or more slurry polymerization reactors, more preferably in at least three slurry phase reactors, for example in three exact slurry phase reactors, including the slurry phase reactor for carrying out the prepolymerization.

[0034] The polymerization in the first polymerization zone is preferably carried out in a slurry. The polymer particles formed in the polymerization are then suspended in a fluid hydrocarbon with the catalyst fragmented and dispersed within the particles. The slurry is agitated to allow transfer of reactants from the fluid to the particles.

[0035] The slurry polymerization is usually carried out in an inert diluent, typically a hydrocarbon diluent, such as methane, ethane, propane, n-butane, isobutane, pentane, hexane, heptane, octane, and the like, or mixtures thereof. Preferably, the diluent is a low boiling hydrocarbon having 1 to 4 carbon atoms, or a combination of such hydrocarbons. A particularly preferred diluent is propane, optionally with small amounts of methane, ethane, and / or butane.

[0036] The ethylene content in the fluid phase of the slurry is 2 to about 50 mol%, preferably about 3 to about 20 mol%, particularly about 5 to about 15 mol%. The advantage of having a high ethylene concentration is that the productivity of the catalyst is increased, but the disadvantage is that more ethylene needs to be recycled than if the concentration is lower.

[0037] The temperature in the slurry polymerization is typically from 50 to 115° C., preferably from 60 to 110° C., particularly from 70 to 100° C. The pressure is from 1 to 150 bar, preferably from 10 to 100 bar.

[0038] The pressure in the first polymerization step is typically from 35 to 80 bar, preferably from 40 to 75 bar, in particular from 45 to 70 bar.

[0039] The residence time in the first polymerization stage is typically from 0.15 hours to 3.0 hours, preferably from 0.20 hours to 2.0 hours, particularly from 0.30 hours to 1.5 hours.

[0040] It may be advantageous to carry out the 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 85-110°C, preferably 90-105°C, and the pressure is 40-150 bar, preferably 50-100 bar.

[0041] The slurry polymerization can be carried out in any reactor known for use in slurry polymerization. Such reactors include continuous stirred tank reactors and loop reactors. It is particularly preferred that the polymerization is carried out in a loop reactor. In a loop reactor, the slurry is circulated at high speed along a closed pipe by using a circulation pump. Loop reactors are generally 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.

[0042] The slurry can be withdrawn from the reactor continuously or intermittently. A preferred method of intermittent withdrawal is the use of settling legs, in which the slurry is concentrated before withdrawing a batch of the concentrated slurry from the reactor. The use of settling legs is disclosed, inter alia, in US-A-3374211, US-A-3242150, and EP-A-1310295. Continuous withdrawal is disclosed, inter alia, in EP-A-899990, EP-A-1415999, EP-A-1591460, and WO-A-2007 / 025640. Said continuous withdrawal is advantageously combined with suitable concentration methods, as disclosed in EP-A-1310295, EP-A-1591460 and EP 3178853 B1.

[0043] As known in the art, hydrogen may be fed into the reactor to control the molecular weight of the polymer. Additionally, one or more alpha-olefin comonomers may be added to the reactor to control the density of the polymer product. The actual amount of hydrogen and comonomer fed depends on the catalyst used and the desired melt index (or molecular weight) and density (or comonomer content) of the resulting polymer.

[0044] Second Polymerization Step

[0045] From the first polymerization step, the first polymer component is transferred to the second polymerization step.

[0046] The polymerization in the second polymerization step b) is carried out in the presence of a single-site polymerization catalyst, as described in more detail below.

[0047] In this process, the second polymerization step b) comprises the polymerization of ethylene monomer and, optionally, at least one other alpha-olefin comonomer, preferably a C4-C 10 alpha-olefin comonomer.

[0048] In one embodiment, the second polymerization step comprises polymerizing ethylene and 1-hexene, and optionally at least one olefin comonomer, to produce a polyethylene copolymer or an ethylene terpolymer, respectively.

[0049] The second polymerization step is preferably carried out in one or more gas phase polymerization reactors.

[0050] The gas phase polymerization is typically carried out in a gas-solids fluidized bed, also known as a gas phase reactor (GPR). Gas solids olefin polymerization reactors are commonly used for the polymerization of alpha-olefins, such as ethylene and propylene, because they allow relatively high flexibility in polymer design and the use of various catalyst systems. A common variation of the gas solids olefin polymerization reactor is the fluidized bed reactor.

[0051] A gas-solid olefin polymerization reactor is a polymerization reactor for heterophase polymerization of one or more gaseous olefin monomers into polyolefin powder particles, which comprises three zones: in the bottom zone, a fluidization gas is introduced into the reactor; in the middle zone, which usually has a generally cylindrical shape, one or more olefin monomers present in the fluidization gas are polymerized to form polymer particles; in the top zone, the fluidization gas is withdrawn from the reactor. In some gas-solid olefin polymerization reactors, a fluidization grid (also named distribution plate) separates the bottom zone from the middle zone. In some gas-solid olefin polymerization reactors, the top zone forms a disengaging zone or entrainment zone where the fluidization gas expands due to its expanding diameter compared to the middle zone, and where the gas disengages from the polyolefin powder.

[0052] Dense phase refers to the region in the intermediate zone of a gas-solid olefin polymerization reactor that has an increased bulk density due to the formation of said polymer particles. In certain gas-solid olefin polymerization reactors, i.e. fluidized bed reactors, said dense phase is formed by the fluidized bed.

[0053] The temperature in the gas phase polymerization is typically 40 to 120°C, preferably 50 to 100°C, and more preferably 65 to 90°C.

[0054] The pressure in the gas phase polymerization is typically from 3 to 40 bar, preferably from 5 to 35 bar, more preferably from 10 to 32 bar, and even more preferably from 15 to 30 bar.

[0055] The residence time in the gas phase polymerization is from 1.0 to 4.5 hours, preferably from 1.5 to 4.0 hours, particularly preferably from 2.0 to 3.5 hours.

[0056] The polymer production rate in the gas phase reactor is 10 tn / h to 65 tn / h, preferably 12 tn / h to 58 tn / h, particularly 13 tn / h to 52.0 tn / h, and therefore the total polymer withdrawal rate from the gas phase reactor is 15 tn / h to 100 tn / h, preferably 18 tn / h to 90 tn / h, particularly 20 tn / h to 80.0 tn / h.

[0057] The product split (second polymer component (B) % / first polymer component (A) %) may be 0.65 to 2.5, preferably 0.8 to 2.3, and most preferably 1.0 to 1.65.

[0058] The gas phase polymerization can be carried out in any reactor known for use in gas phase polymerization. Such reactors include fluidized bed reactors, fast fluidized bed reactors, or settled bed reactors, or any combination thereof. When a combination of reactors is used, the polymer is transferred from one polymerization reactor to another. Moreover, some or all of the polymer from a polymerization stage may be returned to a previous polymerization stage.

[0059] It is often preferable to remove reactants from a previous polymerization stage from the polymer before introducing the reactants into a subsequent polymerization stage. This is preferably done when the polymer is transferred from one polymerization stage to another.

[0060] Single-site polymerization catalyst

[0061] The polymerization catalyst utilized in the present process is a single-site polymerization catalyst. A single-site polymerization catalyst typically comprises (i) a transition metal complex, (ii) a cocatalyst, and, optionally, (iii) a support.

[0062] Preferably, the first and second polymerization steps are carried out using the same single-site catalyst, ie in the presence of the same metallocene catalyst.

[0063] The catalyst can be transferred into the first reactor by any means known in the art: for example, it can be suspended in a diluent and maintained as a slurry, it can be mixed with a viscous mixture of grease and oil and the resulting paste fed into the polymerization zone, or it can be allowed to settle and part of the catalyst mud thus obtained can be introduced into the polymerization.

[0064] The process preferably utilizes a single-site catalyst. Polyethylene copolymers produced with single-site catalysts, in contrast to Ziegler-Natta catalysts, have properties that allow them to be distinguished from Ziegler-Natta materials. In particular, the comonomer distribution is more uniform. This can be shown using the TREF technique or the Crystaf technique. The catalyst residue may also indicate the catalyst used. Ziegler-Natta catalysts do not contain group (IV) metals, for example Zr or Hf.

[0065] The single-site polymerization catalyst of the present invention preferably has a compressive strength of at least 5 MPa, preferably at least 5.5 MPa, particularly preferably from 6 to 25 MPa, more preferably from 7 to 20 MPa, and even more preferably from 7 to 15 MPa.

[0066] The crushing strength can be determined by measuring the individual crushing strength of any 10 or more particles, for example, exactly 10 particles, using a compression tester, typically under an inert atmosphere, and calculating the average value of the measured values ​​as the compressive strength of the polymerization catalyst. The average value of the measured values ​​is preferably calculated after removing statistical outliers. The crushing strength can be measured using a micro compression tester MCT-510 manufactured by Shimadzu Corporation.

[0067] The single-site polymerization catalyst of the present invention preferably has a ratio of co-catalyst (ii) to transition metal complex (i) of more than 50 mol / mol, preferably from 60 to 200 mol / mol, more preferably from 100 to 160 mol / mol, and even more preferably from 110 to 150 mol / mol.

[0068] Transition metal complexes (i)

[0069] The transition metal complex comprises a transition metal (M) from groups 3 to 10 of the periodic table (IUPAC 2007), or an actinide or lanthanide transition metal (M).

[0070] In accordance with the present invention, the term "transition metal complex" includes any metallocene or non-metallocene compound of a transition metal, which has at least one organic (coordination) ligand and has catalytic activity alone or together with a cocatalyst. Such transition metal compounds are well known in the art, and the present invention covers compounds of metals from groups 3 to 10, such as groups 3 to 7, or groups 3 to 6, such as groups 4 to 6, as well as the lanthanides or actinides of the periodic table (IUPAC 2007).

[0071] Most preferably, the transition metal complex (i) is a metallocene complex, which comprises a transition metal compound as defined above.

[0072] The metallocene complexes of the present invention may have the structure of formula (I): [ka] where each X is a sigma donor ligand; each Het is independently a monocyclic or polycyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from an O atom, a N atom, or a S atom; L is a divalent bridge based on carbon, silicon or germanium atoms, where one or two backbone atoms connect the ligands; M is Ti, Zr or Hf; Each R1 may be the same or different; C 1~10 Alkyl group, C 1~10 Alkoxy group, benzyl group, O-benzyl group, 1 to 3 C 1~6 A phenyl group optionally substituted by an alkyl group, or 1 to 3 C 1~6 an O-phenyl group, optionally substituted by an alkyl group; and / or two adjacent R groups, together with the atoms to which they are attached, form a further ring, such as, for example, forming an indenyl ring together with the Cp ring, where said further ring is optionally substituted by up to four R groups; Each R3 may be the same or different; C 1~10 Alkyl group, C 1~10 Alkoxy group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; each n is 0 to 3; Each R2 may be the same or different; C 1~10 Alkyl group, C 1~10 an alkoxy group or a -Si(R)3 group; Each R is C 1~10 Alkyl group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; and Each p is 0 to 3.

[0073] The following preferences apply to all general formulae herein.

[0074] M is preferably Zr or Hf, more preferably Zr.

[0075] Each X is independently a sigma donor ligand. Thus, each X may be the same or different, and is preferably a hydrogen atom, a halogen atom, a linear or branched, cyclic or acyclic, C 1~20 Alkyl group or C 1~20Alkoxy group, C 6~20 Aryl group, C 7~20 Alkylaryl group or C 7~20 It is an arylalkyl group.

[0076] In one embodiment, the X group is trihydrocarbylsilyl, C 1~10 Alkoxy group, C 1~10 Alkoxy group-C 1~10 It may be an alkyl group or an amide group.

[0077] The term "halogen" includes fluoro, chloro, bromo and iodo groups, preferably chloro.

[0078] Amide groups of interest are -NH2, -NHC 1~6 Alkyl, or -N(C 1~6 alkyl)2.

[0079] More preferably, each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 It is an alkoxy group, an amido group, a phenyl group or a benzyl group.

[0080] Even more preferably, each X is independently a halogen atom, a linear or branched C 1~4 Alkyl or C 1~4 It is an alkoxy group, a phenyl group or a benzyl group.

[0081] Most preferably, each X is independently a chloro group, a benzyl group, a cyclohexyl group, or a methyl group.

[0082] Preferably, both X groups are the same.

[0083] The most preferred choices for both X groups are two chloro groups, two methyl groups or two benzyl groups.

[0084] L is a bridge based on a carbon atom, a silicon atom or a germanium atom. There are 1-2 backbone bond atoms between the two ligands, such as structures like Ligand-C-Ligand (one backbone atom) or Ligand-Si-Si-Ligand (two backbone atoms).

[0085] The bridging atoms may carry other groups. For example, suitable bridging ligands L are selected from -R'2C-, -R'2C-CR'2-, -R'2Si-, -R'2Si-SiR'2-, -R'2Ge-, where each R' is independently a hydrogen atom or a C1-C2 heteroatom, optionally containing one or more heteroatoms of groups 14 to 16 of the periodic table or fluorine atoms. 20 It is a hydrocarbyl group, or optionally two R' groups taken together form a ring. In one embodiment, R' can be an alkyl optionally substituted with alkoxy having 1 to 10 carbon atoms.

[0086] The term "heteroatom" includes, for example, a Si atom, a N atom, an O atom, or a S atom when it belongs to Groups 14 to 16 of the periodic table.

[0087] Preferably, L is -R'2Si-, ethylene or methylene.

[0088] In the formula -R'2Si-, each R' is independently preferably C1-C 20 It is a hydrocarbyl group. Hence the term "C 1~20 The "hydrocarbyl group" is 1~20 Alkyl group, C 2~20 Alkenyl group, C 2~20 Alkynyl group, C 3~20 Cycloalkyl groups, C 3~20 Cycloalkenyl group, C 6~20 Aryl group, C 7~20 Alkylaryl group or C 7~20 arylalkyl groups, or combinations of these groups, such as cycloalkyl substituted with alkyl. 1~20 The hydrocarbyl group is C 1~20Alkyl, C 2~20 Alkenyl, C 4~20 Cycloalkyl, C 5~20 Cycloalkylalkyl groups, C 7~20 Alkylaryl group, C 7~20 Arylalkyl group or C 6~20 It is an aryl group.

[0089] In one embodiment, the formula -R'2Si- represents a silacycloalkanediyl, for example, silacyclobutane, silacyclopentane, or 9-silafluorene.

[0090] Preferably, both R' groups are the same. R' is a C1-C alkoxy group, optionally substituted with an alkoxy group having 1 to 10 carbon atoms. 10 Preferred R' groups are methyl, ethyl, propyl, isopropyl, tert-butyl, isobutyl, C 2~10 Alkenyl group, C 3~8 cycloalkyl, cyclohexylmethyl, phenyl or benzyl; more preferably, each R' is independently 1~ C6 alkyl, C 2~10 Alkenyl, C 5~6 Preferably, R' is a cycloalkyl group or a phenyl group, and most preferably, both R' are methyl or one is methyl and the other is cyclohexyl. Most preferably, the bridge is -Si(CH3)2-.

[0091] The Het groups may be the same or different, preferably the same. The Het groups are monocyclic or polycyclic heteroaromatic or heterocyclic groups containing at least one heteroatom selected from O, N or S atoms. When N is present in a ring, depending on the structure of the ring, it can be H or C. 1~6 It may have an alkyl group.

[0092] Preferably, the Het group is monocyclic. Preferably, the Het group is heteroaromatic. Preferably, the Het group is a monocyclic heteroaromatic group. Preferably, the Het group is a 5- or 6-membered heteroaromatic or heterocyclic ring structure.

[0093] Preferred Het groups include furanyl, tetrahydrofuranyl, thiophenyl, pyridyl, piperidinyl, or pyrrole.

[0094] It is preferred that there is one heteroatom in the Het ring. It is preferred that the heteroatom is an O atom or a S atom, preferably an O atom. It is most preferred that Het is furanyl. It is preferred that the link from the Het group to the cyclopentadienyl ring is on the carbon atom adjacent to the heteroatom. It is preferred that the link from the Cp group to the Het ring is on the carbon atom adjacent to the linker L.

[0095] Each R1 may be the same or different; C 1~10 Alkyl group, C 1~10 Alkoxy group, benzyl group, O-benzyl group (i.e., OBz), C 6~10 Aryl, OC 6~10 Aryl, 1-3 C 1~6 A phenyl group optionally substituted by an alkyl group, or 1 to 3 C 1~6 an O-Ph group optionally substituted by an alkyl group; and / or Two adjacent R groups, together with the atoms to which they are attached, form a further ring, such as, for example, to form an indenyl ring together with the Cp ring, where the further ring may be substituted by up to four R groups.

[0096] However, it is preferred if there are no fused rings and therefore the ligand comprises two cyclopentadienyl rings.

[0097] Each R1 is preferably C 1~6 Alkyl group, C 1~6Alkoxy group, benzyl group, 1 to 3 C 1~6 It is a phenyl group which may be substituted by an alkyl group.

[0098] More preferably, R1 is C 1~6 An alkyl group, for example a methyl group, an ethyl group or a tert-butyl group.

[0099] The subscript "n" is preferably 1 or 2, i.e., when the ring is substituted. When n is 2, R1 is preferably methyl. When n is 1, R1 is preferably t-Bu.

[0100] If n is ≥ 1, it is preferred that the R1 groups are not bound to the same C atom.

[0101] When n=2, the R1 groups are preferably adjacent. When n=2, the R1 groups are preferably attached to the carbon atom adjacent to the bridge L and the next carbon atom.

[0102] When n=1, the R1 group is preferably not adjacent to the linker L or to the Het group.

[0103] Each R2 may be the same or different; C 1~10 Alkyl group, C 1~10 It is an alkoxy group or a -Si(R)3 group. It is preferred that R2 is a -Si(R)3 group.

[0104] Each R is independently 1~6 Alkyl group or 1 to 3 C 1~6 It is a phenyl group optionally substituted by an alkyl group. Thus, each R group may be the same or different.

[0105] The R group is preferably phenyl or C 1~4 In one embodiment, one R is phenyl and the other R group is C 1~4In another embodiment, all R groups are C 1~4 It is an alkyl group. It is preferred to use -SiPhMe2 or -SiMe3.

[0106] It is preferred that p is 0 or 1, and more preferably p=1.

[0107] When p is other than 0, the R2 substituent is preferably on the carbon atom adjacent to the heteroatom.The R2 group is preferably not bonded to the same carbon atom as the link to the Cp ring.When the Het group is furanyl, the Het ring is preferably linked to the Cp ring and the Het group (if present) through the two carbon atoms adjacent to the O atom.

[0108] The complexes used in the present invention are preferably of formula (II) below: [ka] where each X is independently a hydrogen atom, a halogen atom, or C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; each Het is independently a monocyclic or polycyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from an O atom, a N atom, or a S atom; L is -R'C- or -R'Si-, where each R' is independently optionally substituted with an alkoxy group having 1 to 10 carbon atoms; 1~20 Hydrocarbyl or C 1~10 is alkyl; M is Ti, Zr or Hf; Each R1 may be the same or different; C 1~10 Alkyl group, C 1~10 Alkoxy group, benzyl group, O-benzyl group, 1 to 3 C 1~6 A phenyl group optionally substituted by an alkyl group, or 1 to 3 C 1~6an O-phenyl group, optionally substituted by an alkyl group; and / or two adjacent R groups, together with the atoms to which they are attached, form a further ring, such as, for example, forming an indenyl ring together with the Cp ring, where said further ring is optionally substituted by up to four R groups; Each R3 may be the same or different; C 1~6 Alkyl group, C 1~6 Alkoxy group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; each n is 0 to 3; Each R2 may be the same or different; C 1~10 Alkyl group, C 1~10 an alkoxy group or a -Si(R)3 group; Each R is C 1~10 Alkyl group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; and Each p is 0 to 3.

[0109] The metallocene complexes of the present invention are preferably of formula (III): [ka] where each X is independently a hydrogen atom, a halogen atom, or C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; each Het is independently a monocyclic or polycyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from an O atom, a N atom, or a S atom; L is -R'C- or -R'Si-, where each R' is independently optionally substituted with an alkoxy group having 1 to 10 carbon atoms; 1~20 Hydrocarbyl or C 1~10 is alkyl; M is Ti, Zr or Hf; Each R1 may be the same or different; C 1~10 Alkyl group, C 1~10 Alkoxy group, benzyl group, O-benzyl group, 1 to 3 C 1~6 A phenyl group optionally substituted by an alkyl group, or 1 to 3 C 1~6 an O-phenyl group optionally substituted by an alkyl group; each n is 0 to 3; Each R2 may be the same or different; C 1~6 Alkyl group, C 1~6 an alkoxy group or a -Si(R)3 group; Each R is C 1~6 Alkyl group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; and Each p is 0 to 3.

[0110] The metallocene complexes of the present invention are preferably of formula (IV): [ka] where each X is independently a hydrogen atom, a halogen atom, or C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; each Het is independently a monocyclic heteroaromatic group containing at least one heteroatom selected from an O atom, a N atom, or a S atom; L is -R'C- or -R'Si-, where each R' is independently optionally substituted with an alkoxy group having 1 to 10 carbon atoms; 1~20 Hydrocarbyl or C 1~10 is alkyl; M is Ti, Zr or Hf; Each R1 may be the same or different; C 1~6 Alkyl group or C 1~6 is an alkoxy group; each n is 0 to 3; Each R2 may be the same or different; C 1~6 Alkyl group, C 1~6 an alkoxy group, or a -Si(R)3 group; Each R is independently 1~6 Alkyl group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; and Each p is 0 to 3.

[0111] The metallocene complexes of the present invention are preferably of formula (V): [ka] where each X is independently a hydrogen atom, a halogen atom, or C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; Each Het is independently a monocyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from an O atom or a S atom; L is -R'2Si-, where each R' is independently optionally substituted with an alkoxy group having 1 to 10 carbon atoms; 1~20 Hydrocarbyl or C 1~10 is alkyl; M is Ti, Zr or Hf; Each R1 may be the same or different; C 1~6 Alkyl group or C 1~6 is an alkoxy group; each n is 1 to 2; Each R2 may be the same or different; C 1~6 Alkyl group, C 1~6 an alkoxy group or a -Si(R)3 group; Each R is C 1~10 Alkyl group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; and Each p is an integer from 0 to 1.

[0112] The complexes used in the present invention are preferably of formula (VI) below: [ka] where each X is independently a hydrogen atom, a halogen atom, or C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; each Het is independently a monocyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from an O atom or a S atom; L is -R'Si-, where each R' is independently C 1~10 Alkyl, C 3~8 Cycloalkyl or C 2~10 alkenyl; M is Ti, Zr or Hf; Each R1 may be the same or different; C 1~6 is an alkyl group; each n is 1 to 2; each R2, which may be the same or different, is a -Si(R)3 group; Each R is C 1~10 Alkyl group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; and Each p is an integer from 0 to 1.

[0113] The metallocene complexes of the present invention are preferably of formula (VII): [ka] wherein each X is a sigma donor ligand, e.g., wherein each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; L is a divalent bridge based on carbon, silicon or germanium atoms, where one or two backbone atoms link the ligands, e.g., -R'2Si-, where each R' may be independently substituted with an alkoxy group having 1 to 10 carbon atoms; 1~20 Hydrocarbyl or C 1~10 is alkyl; Each R1 may be the same or different; C 1~6 is an alkyl group; each n is 0 to 3; Each R2 may be the same or different; C 1~6 an alkyl group or a -Si(R)3 group; Each R is C 1~10 Alkyl group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; and Each p is 0 to 3.

[0114] The metallocene complexes of the present invention are preferably of formula (VIII): [ka] wherein each X is a sigma donor ligand, e.g., wherein each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; L is a divalent bridge based on carbon, silicon or germanium atoms, where one or two backbone atoms link the ligands, e.g., -R'2Si-, where each R' may be independently substituted with an alkoxy group having 1 to 10 carbon atoms; 1~20 Hydrocarbyl or C 1~10 is alkyl; Each R1 may be the same or different; C 1~6 is an alkyl group; each n is 1 to 2; R2 is a -Si(R)3 alkyl group; Each R is C 1~10 Alkyl group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; Each p is 1.

[0115] The metallocene complexes of the present invention are preferably of formula (IX) below: [ka] wherein each X is a sigma donor ligand, e.g., wherein each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; L is Me2Si- or (Me)C 2~10 Alkenyl Si; Each R1 may be the same or different; C 1~6 an alkyl group, such as methyl or t-Bu; each n is 1 to 2; R2 is a -Si(R)3 alkyl group; Each R is C 1~6 is an alkyl group or a phenyl group; and Each p is 1; For example, the compound represented by the formula (IX') [ka] wherein each X is a sigma donor ligand, e.g., wherein each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; L is Me2Si- or (Me)C 2~10 Alkenyl Si; Each R1 may be the same or different; C 1~6 an alkyl group, such as methyl or t-Bu; each n is 1 to 2; R2 is a -Si(R)3 alkyl group; Each R is C 1~6 It is an alkyl group or a phenyl group.

[0116] The metallocene complexes of the invention are in particular of formula (X) [ka] wherein each X is a sigma donor ligand, e.g., wherein each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; L is a divalent bridge based on carbon, silicon or germanium atoms, where one or two backbone atoms link the ligands, e.g., -R'2Si-, where each R' may be independently substituted with an alkoxy group having 1 to 10 carbon atoms; 1~20 Hydrocarbyl or C 1~10 is alkyl; M is Ti, Zr or Hf; each Het is independently a monocyclic heteroaromatic or heterocyclic group containing at least one heteroatom selected from an O atom, a N atom, or a S atom; Each R1 may be the same or different; C 1~10 is an alkyl group; each n is 1 to 3; each R2 may be the same or different and is a -Si(RaRbRc) group; Ra is C 1~6 is alkyl; Rb is C 1~6 is alkyl; Rc is 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; and each p is 1 to 3; For example, of the following formula (X'): [ka] wherein each X is a sigma donor ligand, e.g., wherein each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; L is a divalent bridge based on carbon, silicon or germanium atoms, where one or two backbone atoms link the ligands, e.g., -R'2Si-, where each R' may be independently substituted with an alkoxy group having 1 to 10 carbon atoms; 1~20 Hydrocarbyl or C 1~10 is alkyl; Each R1 may be the same or different; C 1~10 is an alkyl group; each n is 1 to 3; each R2 may be the same or different and is a -Si(RaRbRc) group; Ra is C 1~6 is alkyl; Rb is C 1~6 is alkyl; and Rc is 1 to 3 C 1~6 It is a phenyl group which may be substituted by an alkyl group.

[0117] More preferred complexes are of formula (XI): [ka] wherein each X is a sigma donor ligand, e.g., wherein each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; L is a divalent bridge based on carbon, silicon or germanium atoms, where one or two backbone atoms link the ligands, e.g., -R'2Si-, where each R' may be independently substituted with an alkoxy group having 1 to 10 carbon atoms; 1~20 Hydrocarbyl or C1~10 is alkyl; each Het is independently a monocyclic heteroaromatic group containing at least one heteroatom selected from an O atom, a N atom, or a S atom; M is Ti, Zr or Hf; Each R1 may be the same or different, and each R1 may be a branched C 3~10 is an alkyl group; each R2, which may be the same or different, is a -Si(R)3 group; Each R is C 1~10 Alkyl group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; and Each p is 1, For example, of formula (XI'): [ka] wherein each X is a sigma donor ligand, e.g., wherein each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; L is a divalent bridge based on carbon, silicon or germanium atoms, where one or two backbone atoms link the ligands, e.g., -R'2Si-, where each R' may be independently substituted with an alkoxy group having 1 to 10 carbon atoms; 1~20 Hydrocarbyl or C 1~10 is alkyl; Each R1 may be the same or different, and each R1 may be a branched C 3~10 is an alkyl group; each R2, which may be the same or different, is a -Si(R)3 group; Each R is C 1~10 Alkyl group or 1 to 3 C 1~6 It is a phenyl group which may be substituted by an alkyl group.

[0118] An even more preferred metallocene complex is of formula (XII): [ka] wherein each X is a sigma donor ligand, e.g., wherein each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; each Het is independently a monocyclic heteroaromatic group containing at least one heteroatom selected from an O atom, a N atom, or a S atom; L is a (RdRe)Si group; Rd is C 1~10 is an alkyl group; Re is C 2~10 is an alkenyl group; M is Ti, Zr or Hf; Each R1 may be the same or different; C 1~10 is an alkyl group; each n is 1 to 3; each R2, which may be the same or different, is a -Si(R)3 group; Each R is C 1~10 Alkyl group or 1 to 3 C 1~6 a phenyl group optionally substituted by an alkyl group; and Each p is 0 to 3; For example, of formula (XII'): [ka] wherein each X is a sigma donor ligand, e.g., wherein each X is independently a hydrogen atom, a halogen atom, C 1~6 Alkyl group, C 1~6 an alkoxy group, an amido group, a phenyl group, or a benzyl group; L is a (RdRe)Si group; Rd is C 1~10 is an alkyl group; Re is an alkenyl group; Each R1 may be the same or different; C 1~10 is an alkyl group; each n is 1 to 3; each R2 may be the same or different and is a -Si(R)3 group; and Each R is C 1~10 Alkyl group or 1 to 3 C 1~6 It is a phenyl group which may be substituted by an alkyl group.

[0119] Highly preferred complexes are: [ka]

[0120] Cocatalyst (ii)

[0121] In order to form an active catalytic species, it is usually necessary to use a promoter, as is well known in the art.

[0122] According to the present invention, a cocatalyst containing a Group 13 element is required, such as a boron-containing cocatalyst or an Al-containing cocatalyst. Most preferably, an aluminoxane cocatalyst is used in combination with the metallocene catalyst complex defined above.

[0123] The alumoxane cocatalyst can be of formula (ii-I): [ka] Here, n is 6 to 20, and R has the following meaning:

[0124] Aluminoxanes are formed, for example, by partial hydrolysis of organoaluminum compounds, such as those of the formulae AlR3, AlR2Y and Al2R3Y3, where R is, for example, C1-C 10 Alkyl, preferably C1 to C5 alkyl, or C 3~10 -Cycloalkyl, C7-C 12arylalkyl or alkylaryl, and / or phenyl or naphthyl, where Y is a hydrogen atom, a halogen atom, preferably a chlorine atom or a bromine atom, or a C1-C 10 The alkoxy group is preferably methoxy or ethoxy. The resulting oxygen-containing aluminoxanes are generally not pure compounds but are combinations of oligomers of the formula (ii-I).

[0125] A preferred aluminoxane is methylaluminoxane (MAO). The aluminoxanes used according to the invention as cocatalysts are not pure compounds due to their mode of preparation, therefore hereinafter the molar ratios of the aluminoxane solutions are based on their aluminum content.

[0126] A boron-containing cocatalyst may also be used, optionally in combination with an aluminoxane cocatalyst. Boron-containing cocatalysts of interest include those of formula (ii-II) below: BY3(ii-II) wherein Y may be the same or different and is a hydrogen atom, an alkyl group of 1 to about 20 carbon atoms, an aryl group of 6 to about 15 carbon atoms, an alkylaryl, an arylalkyl, a haloalkyl or a haloaryl, each of which has 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, or a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. Preferred examples of Y are a fluorine atom, trifluoromethyl, an aromatic fluorinated group such as p-fluorophenyl, 3,5-difluorophenyl, pentafluorophenyl, 3,4,5-trifluorophenyl and 3,5-di(trifluoromethyl)phenyl. Preferred choices are trifluoroborane, tris(4-fluorophenyl)borane, tris(3,5-difluorophenyl)borane, tris(4-fluoromethylphenyl)borane, tris(2,4,6-trifluorophenyl)borane, tris(pentafluorophenyl)borane, tris(3,5-difluorophenyl)borane and / or tris(3,4,5-trifluorophenyl)borane.

[0127] Particularly preferred is tris(pentafluorophenyl)borane.

[0128] However, it is preferred to use borates, ie compounds which contain borate.

[0129] These compounds generally comprise anions of the following formulas (ii-III): (Z)4B - (ii-III) wherein Z is an optionally substituted phenyl derivative, wherein the substituent is halo-C 1~6 It is an alkyl or halo group. The preferred choices are fluoro or trifluoromethyl. Most preferably, the phenyl group is perfluorinated.

[0130] Such ionic cocatalysts are preferably weakly-coordinating anions, such as tetrakis(pentafluorophenyl)borate or tetrakis(3,5-di(trifluoromethyl)phenyl)borate.

[0131] Suitable cationic counterions include triphenylcarbenium and protonated amine or aniline derivatives, such as methylammonium, anilinium, dimethylammonium, diethylammonium, N-methylanilinium, diphenylammonium, N,N-dimethylanilinium, trimethylammonium, triethylammonium, tri-n-butylammonium, methyldiphenylammonium, pyridinium, p-bromo-N,N-dimethylanilinium, or p-nitro-N,N-dimethylanilinium.

[0132] Preferred ionizing compounds that may be used in accordance with the present invention include: tributylammonium tetrakis(pentafluorophenyl)borate, tributylammonium tetrakis(trifluoromethylphenyl)borate, tributylammonium tetrakis(4-fluorophenyl)borate, N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylbenzylammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-di(propyl)ammonium tetrakis(pentafluorophenyl)borate, di(cyclohexyl)ammonium tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, or Ferrocenium tetrakis(pentafluorophenyl)borate.

[0133] Preferably, the following is provided: triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dimethylcyclohexylammonium tetrakis(pentafluorophenyl)borate, or N,N-Dimethylbenzylammonium tetrakis(pentafluorophenyl)borate.

[0134] The preferred borates for use in the present invention include the trityl, i.e., triphenylcarbenium ion. Hence, the use of Ph3CB(PhF5)4 and their analogs is particularly preferred.

[0135] Suitable amounts of promoter will be known to those skilled in the art.

[0136] Support (iii)

[0137] The polymerization catalyst of the present invention can be used in solid but unsupported form according to the protocol of WO03 / 051934.The catalyst system of the present invention is preferably used in solid supported form.The particle support material used can be an inorganic porous support, such as silica, alumina, or mixed oxides, such as silica-alumina, especially silica.

[0138] The use of a silica support is preferred.

[0139] Particularly preferably, the support is a porous material, so that the complex can be supported within the pores of the particulate support using similar processes as described, for example, in WO 94 / 14856, WO 95 / 12622, WO 2006 / 097497 and EP 1828266.

[0140] The average particle size of the support, e.g., silica support, can typically be from 10 to 100 μm. Preferably, the average particle size of the silica support is from 10 to 40 μm, preferably from 15 to 35 μm. The average particle size (i.e., median particle size, D 50 ) can be determined using a laser diffraction particle size analyzer Malvern Mastersizer 3000 (sample dispersion: dry powder).

[0141] The average pore size of the support, for example a silica support, can range from 10 to 100 nm and the pore volume can be from 1 to 3 mL / g.

[0142] 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 and sold by AGC Si-Tech Co. The support can optionally be calcined prior to use in the catalyst preparation to reach an optimum silanol group content.

[0143] The catalyst may comprise 5 to 500 μmol, for example 10 to 100 μmol, of transition metal complex (i) per gram of support, and 3 to 15 mmol of co-catalyst (ii), for example MAO, per gram of support (iii), for example silica.

[0144] Polyethylene Polymer

[0145] The present disclosure relates to the preparation of polyethylene polymers, in particular multimodal ethylene homopolymers or copolymers. The multimodal ethylene homopolymers or copolymers have a density of 900 to 980 kg / m 3 , preferably 905 to 940 kg / m 3 , especially 910-935kg / m 3 , it is possible.

[0146] The polyethylene (co)polymer directly provided by this process is in the form of a polymer powder.

[0147] The polyethylene (co)polymer of the present invention has a particle size distribution of the polyethylene polymer or polyethylene copolymer in powder form described by a log-normal distribution having a scale parameter of less than 0.5, preferably less than 0.45, in particular between 0.1 and 0.45, more preferably between 0.15 and 0.4.

[0148] It is preferred if the multimodal polyethylene polymer is a copolymer. More preferably, the multimodal polyethylene copolymer is LLDPE. It has a viscosity of 905 to 940 kg / m 3 , preferably 910 to 935 kg / m 3 , more preferably 915 to 930 kg / m 3 , especially 916~928kg / m 3 In one embodiment, the density may be 910 to 928 kg / m 3 As used herein, "LLDPE" refers to linear low density polyethylene. The LLDPE is preferably multimodal.

[0149] The term "multimodal" includes polymers that are multimodal with respect to MFR, and therefore includes bimodal polymers. The term "multimodal" can also mean multimodality with respect to "comonomer distribution".

[0150] Usually, polymers containing at least two polyethylene fractions are said to be "multimodal" because they are produced under different polymerization conditions and the fractions have different (weight average) molecular weights and molecular weight distributions. The prefix "multi" 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 of a multimodal polymer, e.g. LLDPE, i.e. the graphical appearance of the polymer weight fraction as a function of molecular weight, may show two or more maxima or at least be clearly broadened compared to the curves for the individual fractions. The final MWD curve is often broad, skewered or shows a shoulder.

[0151] Ideally, the molecular weight distribution curve of the multimodal polymer of the present invention will show two distinct maxima. Alternatively, the polymer fractions have similar MFR and are bimodal in comonomer content. Polymers comprising at least two polyethylene fractions are produced under different polymerization conditions, resulting in different comonomer contents of the fractions, also referred to as "multimodal".

[0152] For example, when a polymer is produced in a sequential, multi-stage process using reactors connected in series and using different conditions in each reactor, the polymer fractions produced in the different reactors will have their own molecular weight distributions and weight average molecular weights. When the molecular weight distribution curve of such a polymer is recorded, the individual curves of these fractions are superimposed on the molecular weight distribution curve for the resulting polymer product as a whole, usually giving a curve with two or more distinct maxima.

[0153] In the possible multimodal polymers, there may be a lower molecular weight component (LMW) and a higher molecular weight component (HMW). The LMW component has a lower molecular weight than the high molecular weight component. This difference is preferably at least 5000 g / mol.

[0154] The multimodal polyethylene polymers used in the present invention preferably have at least one C 4~10 It includes a comonomer, which may be present in the HMW component (i.e., the second component (B), produced in the second polymerization step) or in the LMW component (i.e., the first component (A), produced in the first polymerization step) or in both. Hereinafter, the term "LMW / HMW component" is used, but the described embodiments apply to the first component and the second component, respectively.

[0155] At least one HMW component is C 4~10 It is preferred if it contains a comonomer. The LMW component may then be an ethylene homopolymer or may contain at least one C 4~10 In one embodiment, the multimodal polyethylene polymer comprises a single comonomer. In a preferred embodiment, the multimodal polyethylene polymer comprises at least two, e.g. exactly two, C 4~10 Contains comonomer.

[0156] In one embodiment, the multimodal polyethylene polymer is a terpolymer and comprises at least two C 4~10 In that scenario, the HMW component may be a copolymer or terpolymer component, and the low molecular weight (LMW) component may be an ethylene homopolymer or copolymer component. Alternatively, both the LMW and HMW components may contain at least two C 4~10 It may be a copolymer such that a comonomer is present.

[0157] Thus, the multimodal polyethylene polymer has an HMW component consisting of ethylene and at least two other C 4~10 Alpha-olefin monomers, such as 1-butene, and one C 6~8 and alpha-olefin monomers. Ethylene preferably forms the majority of the LMW or HMW component. In a most preferred embodiment, the LMW component may comprise an ethylene 1-butene copolymer, and the HMW component may comprise an ethylene 1-hexene copolymer.

[0158] The total comonomer content in the multimodal polyethylene polymer may be, for example, from 0.2 to 14.0 mol %, preferably from 0.3 to 12 mol %, more preferably from 0.5 to 10.0 mol %, and most preferably from 0.6 to 8.5 mol %.

[0159] The 1-butene may be present in an amount of 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 %.

[0160] C6~C 10 The alpha-olefin may be present in an amount of from 0.2 to 6 mol %, preferably from 0.3 to 5.5 mol %, and more preferably from 0.4 to 4.5 mol %.

[0161] Preferably, the LMW component has a lower comonomer amount (mol %) than the HMW component, for example the amount of comonomer, preferably 1-butene, in the LMW component is 0.05-0.9 mol %, more preferably 0.1-0.8 mol %, while the amount of comonomer, preferably 1-hexene, in the HMW component (B) is 1.0-8.0 mol %, more preferably 1.2-7.5 mol %.

[0162] If necessary, the comonomer content (mol %) in the HMW component = (comonomer content (mol %) in the final product - weight fraction of the LMW component x comonomer content (mol %) in the LMW component) / (weight fraction of the HMW component).

[0163] Thus, the multimodal polyethylene copolymer may be formed from ethylene along with at least one of 1-butene, 1-hexene, or 1-octene. The multimodal polyethylene polymer may be an ethylene butene hexene center polymer, for example, the HMW component is an ethylene butene hexene center polymer and the LMW is an ethylene homopolymer component. The use of terpolymers of ethylene with 1-octene and 1-hexene comonomers is also envisioned.

[0164] In a further embodiment, the multimodal polyethylene copolymer may comprise two polyethylene copolymers, such as two ethylene butene copolymers or an ethylene butene copolymer (e.g., as the LMW component) and an ethylene hexene copolymer (e.g., as the HMW component). It may also be possible to combine a polyethylene copolymer component with an ethylene terpolymer component, such as an ethylene butene copolymer (e.g., as the LMW component) and an ethylene butene hexene copolymer (e.g., as the HMW component).

[0165] The LMW component of the multimodal polyethylene polymer may 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 may be 50 to 3000 g / 10 min, more preferably 100 to 1000 g / 10 min, for example where the target is a cast film. In some embodiments, the MFR2 of the LMW component may be 0.5 to 50 g / 10 min, more preferably 1.0 to 10 g / 10 min, preferably 1.5 to 9.0, more preferably 2.0 to 8.5, for example where the target is a blown film.

[0166] The molecular weight (Mw) of the low molecular weight component should preferably be from 20,000 to 180,000, for example from 40,000 to 160,000.

[0167] The low molecular weight component is at least 925 kg / m 3 , e.g. at least 940 kg / m 3 , and may have a density of 930 to 950 kg / m 3 , preferably 935 to 945 kg / m 3 , the range of densities is possible.

[0168] The HMW component of the multimodal polyethylene polymer may for example have an MFR2 of less than 1 g / 10 min, for example 0.2 to 0.9 g / 10 min, preferably 0.3 to 0.8 g / 10 min, more preferably 0.4 to 0.7 g / 10 min. The HMW component may have an MFR2 of less than 915 kg / m 3 Less than 910kg / m 3 Less than 905 kg / m 3 The Mw of the high molecular weight component may range from 70,000 to 1,000,000, preferably from 100,000 to 500,000.

[0169] The LMW component may be 30 to 70 wt %, for example 38 to 62 wt %, especially 45 to 55 wt % multimodal polyethylene polymer.

[0170] The HMW component may be from 30 to 70% by weight, such as from 38 to 62% by weight, especially from 45 to 55% by weight, of multimodal polyethylene polymer.

[0171] In one embodiment, there is 40-45 wt.% of the LMW component and 60-55 wt.% of the HMW component.

[0172] In one embodiment, the polyethylene polymer is composed of HMW and LMW components as the only polymer components.

[0173] The multimodal polyethylene polymer of the present invention may have a MFR2 of 0.01 to 50 g / 10 min, preferably 0.05 to 25 g / 10 min, especially 0.1 to 10 g / 10 min.

[0174] 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.

[0175] Multimodal polyethylene polymers can be produced as described herein.Preferably, the multimodal polymers are produced in at least two stages of polymerization, for example using two slurry reactors or two gas-phase reactors or any combination thereof, and can be adopted in any order.However, preferably, the multimodal polymers are produced using slurry polymerization, for example slurry polymerization in two loop reactors connected in series, followed by gas-phase polymerization in a gas-phase reactor.

[0176] Preferably, the low molecular weight polymer fraction is produced in a series of continuously operated loop reactors connected in which ethylene and any comonomers are polymerized in the presence of the polymerization catalyst described above and a chain transfer agent, such as hydrogen, the diluent being typically an inert aliphatic hydrocarbon, preferably isobutane or propane.

[0177] The higher molecular weight component can then be formed in a gas phase reactor using the same catalyst.

[0178] It is also possible to use an additional polymerization step, for example an additional gas phase step.

[0179] It is often preferable to remove reactants from a previous polymerization stage from the polymer before introducing the reactants into a subsequent polymerization stage. This is preferably done when the polymer is transferred from one polymerization stage to another.

[0180] When the high molecular weight component is produced second in a multi-stage polymerization, its properties cannot be measured directly. However, one skilled in the art can use the Hagstrom equation (Hagstrom, The Polymer Processing Society, Europe / Africa Region Meeting, Gothenburg, Sweden, August 19-21, 1997) to determine the density, MFR2, etc., of the high molecular weight component.

[0181] According to Hagstrom, in the formula (Formula 3), a=5.2 and b=0.7 for MFR2. Moreover, w is the weight fraction of another polyethylene polymer component, such as component (A), having a higher MFR. Thus, the LMW component can be taken as component 1 and the HMW component as component 2. MIb is the MFR2 of the final polyethylene.

[0182] The polymers made by the process of the present invention can be used in a variety of applications, such as films, such as blown or cast films. The polymers are also useful in molding applications.

[0183] Working Example

[0184] Experimental Example

[0185] Catalyst Analysis and Characterization

[0186] Al and Zr contents in solid catalyst components by ICP-OES

[0187] In a glove box, an aliquot of catalyst (approximately 40 mg) is weighed into a glass weighing boat using an analytical balance. The sample is then placed in a second steel container equipped with an air inlet and exposed to air overnight. 5 mL of concentrated nitric acid (65%) is then placed in an Xpress microwave container (20 mL) and used to rinse the contents of the boat. The sample is then subjected to microwave-assisted acid digestion using a MARS 6 laboratory microwave unit, which is heated to 150°C within 20 minutes and held at 150°C for 35 minutes. The digested sample is cooled to room temperature and then transferred into a plastic 100 mL volumetric flask. A standard solution containing 1000 mg / L yttrium (0.4 mL) is added. The flask is then filled with distilled water and shaken. The solution is filtered through a 0.45 μm nylon syringe filter and subjected to analysis using a Thermo iCAP 6300 ICP-OES and iTEVA software.

[0188] The instrument is calibrated for Al and Zr using a blank (5% HNO3 solution prepared from concentrated nitric acid) and six standards of 0.005 mg / L, 0.01 mg / L, 0.1 mg / L, 1 mg / L, 10 mg / L and 100 mg / L of Al and Zr in solution. The solutions contain 5% HNO3 (concentrated nitric acid), 4 mg / L Y standard in distilled water. Plastic volumetric flasks are used. Curve fitting and 1 / concentration weighting are used for the calibration curve. Just before the analysis, the calibration curve is verified and adjusted (re-slope function of the instrument) using the blank, 4 mg / L Y in distilled water and 10 mg / L Al and Zr standard samples with 5% concentrated nitric acid HNO3. To verify the gradient, a quality control sample (QC: 1 mg / L Al; 2 mg / L Zr and 4 mg / L LY, 5% HNO3 solution of concentrated nitric acid in distilled water) is run. The QC sample is also run at the end of the scheduled analytical set.

[0189] The Zr content is monitored using a 339.198 nm wavelength line. The Al content is monitored via a 394.401 nm wavelength line. Y 371.030 nm is used as an internal standard. The reported values ​​are calculated back to the original catalyst sample using the original mass of the catalyst aliquot and the dilution amount.

[0190] Compressive strength The crushing strength of the materials in the examples was determined using a Shimadzu Micro Compression Tester MCT-510. The sample material was dispersed on the lower compression plate, and the particles separated therefrom were selected for measurement using an optical microscope. The diameter of the particles was measured using a microscope software tool. The selected sample particles were compressed with constantly increasing loads until the particles broke or a set maximum force was reached. The crushing strength of the material was determined by the maximum compressive load and particle diameter at which the particles broke. The measurements were performed under inert conditions, with a loading rate of 0.4462 mN / s and a maximum load of 40 mN. The crushing strength of 10 randomly selected particles was measured, and the crushing strength of the catalyst was reported as the average value after removing statistical outliers.

[0191] Particle size distribution of catalyst component powders The particle size distribution of the catalyst components is measured using a laser diffraction particle size analyzer Malvern Mastersizer 3000 (sample dispersion: dry powder).

[0192] Polymer Analysis and Characterization

[0193] Bulk density The bulk density of the polymer powder can be determined according to standard methods, such as ISO 60:1977 or ASTM D1895-17.

[0194] MFR The melt flow rate (MFR) is determined according to ISO 1133 and is expressed in g / 10 min. The MFR is an index of the flowability and therefore processability of a polymer. The higher the melt flow rate, the lower the viscosity of the polymer. The MFR2 of polypropylene is determined at a temperature of 230°C and a load of 2.16 kg, the MFR5 of polyethylene at a temperature of 190°C and a load of 5 kg, and the MFR2 of polyethylene at a temperature of 190°C and a load of 2.16 kg.

[0195] density Density is measured according to ISO 1183-2 / 1872-2B.

[0196] Particle size distribution The particle size distribution of the polymer powders was measured using a Coulter LS 200 particle size analyzer according to ISO 13320-1. The instrument is capable of measuring particle size distribution from 0.4 to 2000 μm. The method is a laser diffraction method, where a laser beam is directed at the sample moving in a flow-through cuvette. The polymer sample is first pretreated by screening particles larger than 2 mm. The screened sample is mixed with isopropanol and placed in an ultrasonic device to separate the particles from each other. The pretreated sample is then placed in a sample unit and analyzed.

[0197] Mean and median of particle size distribution (D 50 ) and modes were calculated from the experimental data by using standard statistical distribution analysis methods.

[0198] The log-normal scale and location parameters of the particle size distribution of the polymer powders were determined by fitting a model log-normal distribution to the experimental distribution and calculating the probability density function for the distribution by using the following equation:

number

[0199] GPC The molecular weight averages (Mz, Mw and Mn), the molecular weight distribution (MWD) and its broadness, expressed by the polydispersity index PDI=Mw / Mn, where Mn is the number average molecular weight and Mw is the weight average molecular weight, were 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:

number

[0200] Fixed elution interval ΔV i , where A i and M i are the elution volumes, V i and the polyolefin molecular weight (MW) associated with the chromatogram peak slice area, where N is equal to the number of data points obtained from the chromatogram between the integration limits.

[0201] A high temperature GPC instrument was used, equipped with an infrared (IR) detector (IR4 or IR5 from PolymerChar, Valencia, Spain) and equipped with 3x Agilent-PLgel Olexis and 1x Agilent-PLgel Olexis Guard columns. As solvent and mobile phase, 1,2,4-trichlorobenzene (TCB) stabilized with 250 mg / L 2,6-ditert-butyl-4-methylphenol was used. The chromatographic system was operated at 160°C and a constant flow rate of 1 mL / min. 200 μL of sample solution was injected per analysis. Data collection was performed using either Agilent Cirrus software version 3.3 or PolymerChar GPC-IR control software.

[0202] The column set was calibrated using universal calibration (according to ISO 16014-2:2003) with 19 narrow MWD polystyrene (PS) standards ranging from 0.5 kg / mol to 11,500 kg / mol. The PS standards were dissolved at room temperature for several hours. Conversion of the polystyrene peak molecular weights to polyolefin molecular weights was accomplished by using the Mark Houwink equation and the Mark Houwink constants:

number

[0203] A third order polynomial fit was used to fit the calibration data.

[0204] All samples were prepared in the concentration range of 0.5–1 mg / mL and dissolved at 160 °C with continuous gentle shaking for 2.5 h for PP and 3 h for PE.

[0205] Chemicals and Raw Materials

[0206] The pretreated silica was a commercially available synthetic amorphous silica, ES757, obtained from PQ Corp. The pretreatment refers to commercial calcination of the silica at 600° C. according to conventional PO catalyst technology.

[0207] Methylaluminoxane (30 wt % MAO solution in toluene, Axion CA 1330) was obtained from Lanxess.

[0208] Bis(1-methyl-3-n-butylcyclopentadienyl)zirconium dichloride (30 wt % in toluene) and rac-dimethylsilanediylbis{2-(5-(trimethylsilyl)furan-2-yl)-4,5-dimethylcyclopentadien-1-yl}zirconium dichloride metallocenes were purchased commercially.

[0209] Comparative Catalyst Experimental Example 1 (C-CE1)

[0210] The catalysts used were alumoxane-containing support catalysts including the metallocene bis(1-methyl-3-n-butylcyclopentadienyl)zirconium(IV) chloride and Enhanced ActivCat from Albemarle Grace Corporation. 登録商標 Activation techniques were used.

[0211] Catalyst Example 1 (C-IE1) - Representative Description of Catalyst Preparation Procedure

[0212] SiO2 loading: 10 kg of silica (PQ Corporation ES757, calcined at 600° C.) was added from a feed drum and deactivated in the reactor until the O2 level was below 2 ppm.

[0213] Preparation of metallocene / MAO solutions in toluene: 30 wt% MAO in toluene (14.1 kg) was added from a balance into a separate reactor followed by toluene (4.0 kg) at 25°C (oil circulation temperature) and stirred at 95 rpm. After toluene addition, the stirring speed was increased from 95 rpm to 200 rpm (stirring time 30 min). 477 g of the metallocene Rac-dimethylsilanediylbis{2-(5-(trimethylsilyl)furan-2-yl)-4,5-dimethylcyclopentadiene-1-yl}zirconium dichloride was added from a metal cylinder and then flushed with 4 kg toluene (total toluene 8.0 kg). The stirring speed of the reactor was changed to 95 rpm for MC feed and then back to 200 rpm for a reaction time of 3 hours. After the reaction time, the MAO / tol / MC solution was transferred to the feed vessel.

[0214] Preparation of catalyst: The reactor temperature was set to 10°C (oil circulation temperature) and agitated at 40 rpm for the MAO / tol / MC addition. The MAO / tol / MC solution (target 22.5 kg, actual 22.2 kg) was added within 205 minutes, followed by 60 minutes of agitation (oil circulation temperature set to 25°C). After agitation, the "dry mix" was stabilized at 25°C (oil circulation temperature) and 0 rpm agitation for 12 hours. The reactor was rotated 20° (back and forth) and agitation was performed at 5 rpm for several rounds per hour.

[0215] After stabilization, the catalyst was dried at 60°C (oil circulation temperature) under nitrogen flow of 2 kg / h for 2 hours, followed by drying under vacuum for 13 hours (same nitrogen flow, stirring at 5 rpm). The dried catalyst was sampled and the HC content was measured by thermogravimetry using a Sartorius Moisture Analyser (Model MA45) in a glove box. The target HC level was less than 2% (actual value 1.3%).

[0216] Catalyst Example 2 (C-IE2)

[0217] Catalyst C-IE2 was prepared following the same procedure as C-IE1, except that the silica loading was 5 kg, the MAO loading was 9.87 kg of a 30 wt % solution in toluene, and the rac-dimethylsilanediylbis{2-(5-(trimethylsilyl)furan-2-yl)-4,5-dimethylcyclopentadien-1-yl}zirconium dichloride metallocene loading was 0.238 kg. The process parameters were adjusted accordingly.

[0218] Catalyst Example 3 (C-IE3)

[0219] Catalyst C-IE3 was prepared according to the same procedure as C-IE1, except that the silica loading was 5 kg, the MAO loading was 9.87 kg of a 30 wt% solution in toluene, and the rac-dimethylsilanediylbis{2-(5-(trimethylsilyl)furan-2-yl)-4,5-dimethylcyclopentadien-1-yl}zirconium dichloride metallocene loading was 0.429 kg. The process parameters were adjusted accordingly.

[0220] Comparative Catalyst Experiment 2 (C-CE2)

[0221] Catalyst C-CE2 was prepared according to the same procedure as C-IE1, except that the silica loading was 5 kg, the MAO loading was 6.84 kg of a 30 wt% solution in toluene, and the metallocene was bis(1-n-butyl-3-methylcyclopentadienyl)zirconium dichloride (0.481 kg of a 25 wt% solution in toluene), with the process parameters adjusted accordingly.

[0222] [Table 1]

[0223] Comparative Process Experiment 1 (CPE 1)

[0224] Initial size (D 50 A single-site catalyst (C-CE1) with a diameter of 35 µm was used to produce LLDPE film. 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 of 1-butene per tonne of ethylene, 0.27 Kg of hydrogen per tonne of propane, and 6.50 tn of propane / h (diluent) were fed into the prepoly reactor, and the average residence time was 30 minutes. The product was then cooled to 100 °C for 1 h and then cooled to 150 °C for 2 h. 3The polymer particles were transferred to a split loop reactor configuration with a total volume of 350 m3, operated at a total pressure of 20 barg and a temperature of 75° C. The polymerization conditions were 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, and the overall production rate in the loop reactor was 25 tn / h (total productivity was 2.5 kg / gcat). The material was then flashed out in a high pressure separator, the operating pressure of which was chosen to be equal to 2 barg and the estimated residence time was equal to 5 min. The polymer particles were then transferred to a high pressure separator with a total volume of 350 m3, operated at a total pressure of 20 barg and a temperature of 75° C. 3 (including disengagement zone) 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 was 2 hours. The gas superficial velocity in the gas phase reactor was selected to be 0.45 m / s.

[0225] A cyclone is installed at the exit of the disengagement zone (recirculation gas pipe) to recover entrained particles (which are estimated to be carried over) and to prevent small size particles from passing through the gas compressor and heat exchanger (it is possible to overcome it).

[0226] The catalyst productivity in the GPR was 1.2 kg / gcat (average over 3 days). The product split value was 58%. The fluidized bulk density was 250 kg / m based on ΔP measurements across the fluidized bed (i.e., ΔP=rho*g*hbed). 3 The polymer particles produced and collected were measured to be d 50The particle size distribution was characterized by a mean particle diameter of 550 μm and a log-normal particle size distribution scale parameter of 0.45. The solids carryover was 250 kg / hr. Furthermore, after three days of operation, significant agglomeration problems occurred resulting in serious problems in operability. The GPR operation was suspended after three days of operation due to sheeting and chunking problems, which ultimately led to a shutdown.

[0227] Comparative Example Process Experiment 2 (CPE2)

[0228] The procedure of Example 1 was repeated, except that catalyst C-CE2 was used. The catalyst productivity in the GPR was 0.4 kg / gcat (12-day average). The product split value was 58%. The fluidized bulk density was 270 kg / m based on ΔP measurements across the fluidized bed. 3 The polymer particles produced and collected were measured to be d 50 The particle size distribution was characterized by a mean particle diameter of 381 μm and a log-normal scale parameter of 0.49. The solids carryover was 150 kg / hr. Operation of the GPR was interrupted and ultimately shut down after 12 days of operation due to sheeting and chunking problems.

[0229] Process of the Invention Example 1 (IPE 1)

[0230] The initial size of different single-site catalysts (C-IE1) 50 The procedure of Example 1 was repeated, except that the pore size was about 25 μm. The catalyst productivity in the GPR was 0.9 kg / gcat. The product split value was 58%. The fluidized bulk density was 310 kg / m based on ΔP measurements across the fluidized bed. 3 The polymer particles produced and collected were measured to be d 50The particle size distribution was characterized by a mean diameter of 360 μm and a log-normal scale parameter of 0.36. The solids carryover was 9 kg / hr. The GPR operated smoothly for 20 days.

[0231] Process of the Invention Example 2 (IPE 2)

[0232] The procedure of Example 1 was repeated, except that a different single-site catalyst (C-IE2) was used, with the same initial size as the previously used catalyst (i.e., 25 μm). The catalyst productivity in the GPR was 1.3 kg / gcat. The product split value was 58%. Based on ΔP measurements across the fluidized bed, the fluidized bulk density was 315 kg / m 3 The polymer particles produced and collected were measured to be d 50 The particle size distribution was characterized by a mean diameter of 420 μm and a log-normal scale parameter of 0.33. The solids carryover was 6 kg / hr. The GPR was operated successfully for 20 days.

[0233] Process of the Invention Example 3 (IPE 3)

[0234] The procedure of Example 1 was repeated, except that a different single-site catalyst (C-IE3) was used, with the same initial size as the catalyst used previously. The catalyst productivity in the GPR was 1.6 kg / gcat. The product split value was 58%. The fluidized bulk density was 325 kg / m based on ΔP measurements across the fluidized bed. 3 The polymer particles produced and collected were d 50 The particle size distribution was characterized by a mean diameter of 510 μm and a log-normal scale parameter of 0.34. The solids carryover was 6 kg / hr. The GPR was operated successfully for 20 days.

[0235] The following Tables 2 to 4 show the polymerization results.

[0236] It has been surprisingly found that the compressive strength of the olefin polymerization catalyst of the present invention correlates with the scale parameter of the log-normal particle size distribution of the resulting polymer powder after polymerization reaction in a multi-reactor configuration. The higher the compressive strength of the catalyst particles, the lower the scale parameter, i.e., the lower the skewness of the distribution and the lower the number of large particles (Table 3 below).

[0237] Moreover, it has also been surprisingly found that by using the particular catalyst system of the present invention, reduced solids carryover (solids entrainment) is achieved, as shown in Table 4.

[0238] [Table 2]

[0239] [Table 3]

[0240] [Table 4]

Claims

1. A process for polymerizing an olefin, the process comprising: polymerizing ethylene in the presence of a single-site polymerization catalyst, optionally in the presence of at least one other alpha-olefin comonomer, to produce a polymer component, a polyethylene polymer or a polyethylene copolymer, wherein the polyethylene polymer or the polyethylene copolymer has a particle size distribution described by a lognormal distribution having a scale parameter of less than 0.5, as determined as described in the experimental section of the resulting polyethylene polymer powder or polyethylene copolymer powder; said method.

2. A process for polymerizing an olefin in a plurality of polymerization reactors connected in series to produce a polyethylene polymer or a polyethylene copolymer, the process comprising: a) in a first polymerization step, polymerizing ethylene in the presence of a single-site polymerization catalyst, optionally in the presence of at least one other alpha-olefin comonomer, to form a first polymer component (A); and b) in a second polymerization step, polymerizing an olefin monomer in the presence of the first polymer component (A) of step a), optionally in the presence of at least one other alpha-olefin comonomer, to form a second polymer component (B) comprising wherein the polyethylene polymer or the polyethylene copolymer has a particle size distribution described by a lognormal distribution having a scale parameter of less than 0.5, as determined as described in the experimental section of the resulting polyethylene polymer powder or polyethylene copolymer powder; said method.

3. The method according to claim 1 or 2, wherein the single-site polymerization catalyst comprises (i) a transition metal complex, (ii) a cocatalyst, and optionally (iii) a support, and the ratio of the cocatalyst (ii) to the transition metal complex (i) is greater than 50 mol / mol.

4. The method according to claim 1 or 2, wherein the single-site polymerization catalyst comprises (i) a transition metal complex, (ii) a cocatalyst, and (iii) a support, and wherein the single-site polymerization catalyst has a compressive strength of at least 5 Mpa as determined as described in the experimental section.

5. wherein the transition metal complex (i) is a metallocene complex of the following formula (I): 【Chemical 1】 where each X is a sigma 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 atoms; L is a divalent bridge based on a carbon, silicon, or germanium atom, where one or two backbone atoms link the ligands; M is Ti, Zr, or Hf; each R 1 may be the same or different and is a C 1～10 alkyl group, a C 1～10 alkoxy group, a benzyl group, an O-benzyl group, a phenyl group optionally substituted by 1 to 3 C 1～6 alkyl groups, or an O-phenyl group optionally substituted by 1 to 3 C 1～6 alkyl groups; and / or two adjacent R 1 groups together with the atoms to which they are attached form a further ring, for example an indenyl ring together with a Cp ring, where the further ring may be substituted by up to 4 R 3 groups; each R 3 may be the same or different and is a C 1～10 alkyl group, a C 1～10 alkoxy group, or a phenyl group optionally substituted by 1 to 3 C 1～6 alkyl groups; each n is from 0 to 3; Each R 2 may be the same or different and is a C 1～10 alkyl group, a C 1～10 alkoxy group or a -Si(R) 3 group; Each R is a C 1～10 alkyl group or a phenyl group which may be substituted by 1 to 3 C 1～6 alkyl groups; and each p is from 0 to 3, The method according to claim 3.

6. The transition metal complex (i) is a metallocene complex of the following formula (X), 【Chemical formula 2】 wherein each X is a sigma donor ligand, for example, wherein each X is independently a hydrogen atom, a halogen atom, a C 1～6 alkyl group, a C 1～6 alkoxy group, an amide group, a phenyl group or a benzyl group; L is a divalent bridge based on a carbon atom, a silicon atom or a germanium atom, wherein one or two skeletal atoms link the ligand, for example -R' 2 Si-, and wherein each R’ is independently a C 1～20 hydrocarbyl or a C 1～10 alkyl which may be substituted by an alkoxy group having 1 to 10 carbon atoms; M is Ti, Zr or Hf; each Het is independently a monocyclic heteroaromatic group or a heterocyclic group containing at least one heteroatom selected from an O atom, an N atom or an S atom; Each R 1 may be the same or different and is a C 1～10 alkyl group; each n is from 1 to 3; Each R 2 may be the same or different and is a -Si(RaRbRc) group; Ra is a C 1～6 alkyl; Rb is C 1～6 an alkyl; Rc is a phenyl group which may be substituted by 1 to 3 C 1～6 alkyl groups; and, each p is from 1 to 3, The method according to claim 3.

7. The metallocene complex (X) is of the following formula (XII’), 【Chemical formula 3】 wherein each X is a sigma donor ligand, for example, wherein each X is independently a hydrogen atom, a halogen atom, C 1～6 an alkyl group, C 1～6 an alkoxy group, an amide group, a phenyl group or a benzyl group; L is a (RdRe)Si group; Rd is C 1～10 an alkyl group; Re is C 2～10 an alkenyl group; each R 1 may be the same or different and is a C 1～10 alkyl group; each n is from 1 to 3; each R 2 may be the same or different and is a -Si(R) 3 group; each R is C 1～10 an alkyl group or a phenyl group which may be substituted by 1 to 3 C 1～6 alkyl groups, The method according to claim 6.

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

9. The method according to claim 1 or 2, wherein the lognormal distribution has a scale parameter of 0.1 to 0.

45.

10. A single-site polymerization catalyst comprising (i) a transition metal complex; (ii) a cocatalyst; and, optionally, (iii) a support comprising wherein the single-site polymerization catalyst has a compressive strength determined as described in the experimental section of at least 5 MPa, the single-site polymerization catalyst.

11. wherein the transition metal complex (i) is a metallocene complex of the following formula (I), [Chemical Formula 4] wherein each X is a sigma 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 atoms; L is a divalent bridge based on a carbon, silicon or germanium atom, wherein one or two backbone atoms link the ligands; M is Ti, Zr or Hf; each R 1 may be the same or different and is a C 1～10 alkyl group, a C 1～10 alkoxy group, a benzyl group, an O-benzyl group, a phenyl group optionally substituted by 1 to 3 C 1～6 alkyl groups, or an O-phenyl group optionally substituted by 1 to 3 C 1～6 alkyl groups; and / or, two adjacent R 1 groups together with the atoms to which they are attached form a further ring, for example together with the Cp ring to form an indenyl ring, wherein the further ring may be substituted by up to 4 R 3 groups; each R 3 may be the same or different and is a C 1～10 alkyl group, a C 1～10 alkoxy group, or a phenyl group optionally substituted by 1 to 3 C 1～6 alkyl groups; Each n is from 0 to 3; Each R 2 may be the same or different and is a C 1～10 alkyl group, a C 1～10 alkoxy group or a -Si(R) 3 group; Each R is a C 1～10 alkyl group or a phenyl group which may be substituted by 1 to 3 C 1～6 alkyl groups; and each p is from 0 to 3, The single-site polymerization catalyst according to claim 10.

12. The transition metal complex (i) is a metallocene complex of the following formula (X), 【Chemical Formula 5】 Here, each X is a sigma donor ligand, for example, here each X is independently a hydrogen atom, a halogen atom, a C 1～6 alkyl group, a C 1～6 alkoxy group, an amide group, a phenyl group or a benzyl group; L is a divalent bridge based on a carbon atom, a silicon atom or a germanium atom, where one or two backbone atoms connect the ligand, for example -R' 2 Si-, and here each R’ is independently a C 1～20 hydrocarbyl or C 1～10 alkyl which may be substituted by an alkoxy group having 1 to 10 carbon atoms; M is Ti, Zr or Hf; Each Het is independently a monocyclic heteroaromatic group or a heterocyclic group containing at least one heteroatom selected from an O atom, an N atom or an S atom; Each R 1 may be the same or different and is a C 1～10 alkyl group; each n is from 1 to 3; Each R 2 may be the same or different and is a -Si(RaRbRc) group; Ra is a C 1～6 is alkyl; Rb is C 1～6 is alkyl; Rc is a phenyl group which may be substituted by 1 to 3 C 1～6 alkyl groups; and, each p is from 1 to 3, The single-site polymerization catalyst according to claim 10.

13. The single-site polymerization catalyst according to claim 10, wherein the ratio of the cocatalyst (ii) to the transition metal complex (i) is more than 50 mol / mol.

14. The cocatalyst (ii) is represented by the following formula (ii-I), 【Chemical Formula 6】 wherein n is from 6 to 20 and R is C 1 to C 10 alkyl, or C 3 to C 10 cycloalkyl, C 7 to C 12 arylalkyl or C 7 to C 12 alkylaryl, and / or phenyl or naphthyl; The single-site polymerization catalyst of claim 10.

15. The single-site polymerization catalyst according to claim 10, wherein the cocatalyst (ii) is MAO.

16. A method for using the single-site polymerization catalyst according to claim 10 in the preparation of a polyethylene polymer component, a polyethylene polymer or a polyethylene copolymer, wherein the particle size distribution of the resulting polymer powder, determined as described in the experimental section, is described by a lognormal distribution having a scale parameter of less than 0.

5.

17. A polyethylene polymer or a polyethylene copolymer, which is in powder form and has a particle size distribution described by a lognormal distribution having a scale parameter of less than 0.5 as determined as described in the experimental section for the polyethylene polymer or the polyethylene copolymer.

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