Supported metallocene catalysts for polyethylene wax synthesis, methods of making and using the same

Abstract

The application relates to the technical field of chemical materials, in particular to a supported metallocene catalyst for polyethylene wax synthesis and a preparation method and application thereof. The supported metallocene catalyst comprises a carrier, a main catalyst and a cocatalyst; the main catalyst comprises a metallocene compound with the structure shown in the general formula (I), wherein R1, R3 and R4 are each independently selected from C1-C6 alkyl, R2 and R5 are each independently selected from C6-C13 aromatic group, Ln is selected from rare earth metal, and X is selected from halogen; the cocatalyst is C1-C12 alkyl aluminum or alkyl aluminum oxyalkane; and the carrier is selected from silica gel. The supported metallocene catalyst formed by loading the above metallocene compound with a specific structure as the main catalyst and the cocatalyst on the silica gel carrier has good stability to hydrogen and shows high ethylene absorption rate, high polymerization activity, and can be used to prepare low molecular weight polyethylene wax with narrow molecular weight distribution under low hydrogen partial pressure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical materials, in particular to a supported metallocene catalyst for synthesizing polyethylene wax, a preparation method and application thereof. BACKGROUND

[0002] Polyethylene wax, as an important low molecular weight polyethylene, is widely used in many industrial fields such as plastic processing, paint, ink, cable material and hot melt adhesive, because it has excellent wear resistance, lubricity, dispersibility and good electrical insulation performance. The performance of polyethylene wax mainly depends on its molecular weight and molecular weight distribution (MWD). Generally speaking, the product with low molecular weight (usually Mw<10000) and narrow molecular weight distribution (MWD≈2) performs better in uniformity, gloss and physical properties.

[0003] In the industrial production of polyethylene wax, using metallocene catalyst for ethylene homopolymerization or copolymerization with a small amount of α-olefin is an advanced technical route. Because of its single active center characteristics, metallocene catalyst can theoretically produce polymers with extremely narrow molecular weight distribution. However, in the actual catalytic polymerization system, the partial pressure of hydrogen is one of the key factors to control the molecular weight of the polymer. However, the metallocene catalysts in the prior art still have obvious limitations in response to hydrogen.

[0004] For example, the existing patent CN111154017B discloses a metallocene catalyst for synthesizing polyethylene wax. The technology needs to be carried out under the condition that the hydrogen partial pressure is 0.0333 times the total pressure, and the molecular weight of the prepared polyethylene wax is 1230-3100, and the molecular weight distribution is 2.1-2.4. The results show that under this catalyst system, a certain hydrogen pressure is still needed to obtain low molecular weight products, and the molecular weight distribution of the obtained products is relatively wide, and the advantages of single active center catalyst are not fully reflected. Further, patent CN115160462B reports another metallocene catalyst, which can prepare high-quality narrow-distribution polyethylene wax with a molecular weight of 815-2778 and a molecular weight distribution of 1.26-1.5 under high hydrogen partial pressure (0.333 times-0.438 times the total pressure). However, this catalyst is highly dependent on hydrogen concentration. When the hydrogen partial pressure is reduced to a lower level of 0.0188 times-0.05 times the total pressure, the molecular weight distribution of the obtained polyethylene wax is significantly widened to 2.15-3.36, and the molecular weight is 960-3043. This fully illustrates that the catalyst has insufficient chain transfer efficiency under low hydrogen conditions, resulting in poor consistency of active centers, and cannot stably produce narrow-distribution products under mild process conditions.

[0005] In summary, the metallocene catalysts for synthesizing polyethylene wax in the prior art have a common technical problem: their poor sensitivity or responsiveness to hydrogen. Specifically, to prepare polyethylene wax with sufficiently low molecular weight and narrow distribution, it is often necessary to rely on a higher hydrogen partial pressure, which not only increases the safety requirements and operating costs of the production process, but also limits the possibility of developing products under milder conditions; and under a lower hydrogen partial pressure, these catalysts cannot effectively exert their single-active-center characteristics, resulting in a broad molecular weight distribution of the product, affecting the uniformity of product quality and high-end application performance. SUMMARY

[0006] Therefore, it is necessary to provide a supported metallocene catalyst for synthesizing polyethylene wax, which has good response stability to hydrogen, can still maintain high polymerization activity and efficient chain transfer ability under a lower hydrogen partial pressure, thereby stably and efficiently preparing high-quality polyethylene wax products with low molecular weight and narrow molecular weight distribution. Further, a preparation method and application of the supported metallocene catalyst are provided.

[0007] Firstly, the present application provides a supported metallocene catalyst for synthesizing polyethylene wax, comprising a carrier, a main catalyst and a cocatalyst; the main catalyst comprises a metallocene compound having a structure shown in the following general formula (I),

[0008]

[0009] wherein R1, R3 and R4 are each independently selected from C1-C6 alkyl, R2 and R5 are each independently selected from C6-C13 aromatic group, Ln is selected from rare earth metal, and X is selected from halogen;

[0010] the cocatalyst is C1-C12 alkyl aluminum or alkyl aluminum oxyalkane;

[0011] the carrier is selected from silica gel.

[0012] In the present application, C1-C6 alkyl can refer to a straight-chain or branched-chain alkyl group containing 1 to 6 carbon atoms, or a cyclic alkyl group containing 3 to 6 ring carbon atoms; including but not limited to methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, cyclopropyl, cyclopropyl, cyclopentyl and cyclohexyl, etc.

[0013] Preferably, R1 is methyl.

[0014] Preferably, R3 is methyl.

[0015] Preferably, R4 is tert-butyl.

[0016] Preferably, R2 is phenyl. ​

[0017] Preferably, R5 is phenyl.

[0018] Preferably, Ln is selected from scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium or lutetium; more preferably, Ln is neodymium.

[0019] Preferably, X is selected from F, Cl, Br or I; more preferably, X is Cl.

[0020] Preferably, the co-catalyst is selected from trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, methylaluminoxane or isobutylaluminoxane; more preferably, the co-catalyst is methylaluminoxane.

[0021] Preferably, the molar ratio of aluminum in the co-catalyst to the rare earth metal in the metallocene compound is (50-1000): 1.

[0022] Preferably, the mass ratio of the carrier to the main catalyst is (10-200): 1.

[0023] Preferably, the silica gel can be a common commercial silica gel, including but not limited to Grace 955, Grace 948, Grace SP9-485, Grace SP9-10046, Grace 2212 or Grace 2408D.

[0024] Preferably, the carrier is a modified silica gel; the preparation method of the modified silica gel comprises the following steps:

[0025] dispersing the silica gel in a solvent, adding hydrogen chloride to adjust the pH of the system to 1-4, then adding an aluminum source, controlling the molar ratio of silicon elements to aluminum elements in the system to be (20-200): 1, stirring at 60-65°C for 20-24h, filtering, washing, drying, and finally calcining at 600-650°C for 4-5h to obtain the modified silica gel;

[0026] wherein the solvent is selected from one or more of deionized water, ethanol and isopropanol; and the aluminum source is aluminum chloride, aluminum chloride hexahydrate or aluminum isopropoxide.

[0027] Preferably, the average particle size D50 of the modified silica gel is 10-100μm.

[0028] Preferably, the specific surface area of the modified silica gel is 200m 2 / g-500m 2 / g.

[0029] Preferably, the specific pore volume of the modified silica gel is 1-3cc / g.

[0030] Preferably, the average pore size of the modified silica gel is 10-50nm.

[0031] Based on one general inventive concept, the present application also provides a method for preparing a supported metallocene catalyst for polyethylene wax synthesis, comprising the following steps:

[0032] (a) providing the metallocene compound, the support and the cocatalyst, respectively;

[0033] (b) dissolving the cocatalyst in a first organic solvent, adding the support, heating to 60-80°C, and stirring for 20-24 hours; then sequentially filtering, washing and vacuum drying to obtain a cocatalyst-supported support;

[0034] (c) dissolving the metallocene compound in a second organic solvent, adding the cocatalyst-supported support, heating to 60-80°C, and stirring for 20-24 hours; then sequentially filtering, washing and vacuum drying to obtain a supported catalyst.

[0035] Preferably, the first organic solvent is selected from toluene, xylene, n-heptane or cyclohexane.

[0036] Preferably, the second organic solvent is selected from toluene, xylene, n-heptane or cyclohexane.

[0037] Preferably, the method for preparing the metallocene compound comprises the following steps:

[0038] (a1) providing intermediate 1 having the structure shown in Formula A and intermediate 2 having the structure shown in Formula B, respectively;

[0039] (a2) dissolving the intermediate 1 in an inert organic solvent 1, adding dropwise an alkyl lithium reagent at -70-80°C to perform a lithiation reaction, after the dropwise addition is completed, placing at room temperature to continue the reaction for 12-14 hours; then adding dropwise a halosilane having the structure shown in Formula C at -70-80°C to perform a first nucleophilic substitution reaction, after the dropwise addition is completed, placing at room temperature to continue the reaction for 12-14 hours to obtain a halosilane-containing intermediate;

[0040] (a3) dissolving the halosilane-containing intermediate obtained in step (a2) in an inert organic solvent 2, adding dropwise an alkyl lithium reagent at -70-80°C to perform a lithiation reaction, after the dropwise addition is completed, placing at room temperature to continue the reaction for 12-14 hours; then adding dropwise the intermediate 2 at -70-80°C to perform a second nucleophilic substitution reaction, after the dropwise addition is completed, placing at room temperature to continue the reaction for 12-14 hours, and isolating and purifying to obtain a silicon-bridged metallocene ligand;

[0041] (a4) dissolving the silicon-bridged metallocene ligand obtained in step (a3) in an inert organic solvent 3, adding alkyl lithium dropwise at -5°C to 0°C to perform lithiation reaction, after dropwise addition, placing at room temperature to continue reaction for 12h to 14h, adding rare earth metal halide at -5°C to 0°C, after addition, placing at room temperature to continue reaction for 12h to 14h, separating and purifying to obtain the metallocene compound;

[0042] 、 、 ;

[0043] wherein R1, R3 and R4 are each independently selected from C1-C6 alkyl, R2 and R5 are each independently selected from C6-C13 aromatic group, and X is selected from halogen.

[0044] Preferably, the inert organic solvent 1 is selected from diethyl ether, tetrahydrofuran or toluene.

[0045] Preferably, the inert organic solvent 2 is selected from diethyl ether, tetrahydrofuran or toluene.

[0046] Preferably, the alkyl lithium is selected from n-butyllithium, t-butyllithium or diisopropylaminolithium.

[0047] Preferably, the inert organic solvent 3 is selected from diethyl ether, tetrahydrofuran or toluene.

[0048] Preferably, the silane in step (a2) is dichlorosilane reagent.

[0049] Preferably, the intermediate 1 has a structure as shown in the following formula A1;

[0050] .

[0051] Preferably, the preparation method of the intermediate 1 having a structure as shown in the formula A1 comprises the following steps:

[0052] S1, performing Williamson synthesis reaction on 2-tert-butyl phenol with methyl iodide in the presence of a strong base 1 to generate an anisole derivative;

[0053] S2, performing cyclization reaction on the anisole derivative generated in step S1 with 2-bromo isobutyryl bromide under catalysis of a Lewis acid to obtain a cyclization product;

[0054] S3, performing bromination reaction on the cyclization product obtained in step S2 with a bromination reagent 1 to generate a brominated derivative;

[0055] S4, performing Suzuki coupling reaction on the brominated product obtained in step S3 with R2B(OH)2 in the presence of a palladium catalyst and a basic reagent 1 to generate a coupling derivative;

[0056] S5, subjecting the coupling derivative obtained in step S4 to a reduction reaction under the action of a reducing agent to form a reduction product;

[0057] S6, subjecting the reduction product obtained in step S5 to an elimination reaction under the action of an acidic elimination agent to eliminate the hydroxyl group to obtain an intermediate 1 having a structure as shown in formula A1.

[0058] Preferably, in step S1, the strong base reagent 1 is selected from sodium hydroxide, potassium hydroxide, sodium hydride, preferably potassium hydroxide.

[0059] Preferably, step S1 comprises: first dissolving 2-tert-butyl phenol in organic solvent 1, adding strong base 1 dropwise at -10°C to 30°C (preferably 0°C), after the dropwise addition is completed, place it at room temperature, react for 12h to 14h, then add iodomethane dropwise at -10°C to 30°C (preferably 0°C), after the dropwise addition is completed, place it at room temperature, react for 12h to 14h.

[0060] Preferably, the organic solvent 1 is selected from one of n-hexane, tetrahydrofuran, toluene, xylene, dichloromethane, preferably tetrahydrofuran.

[0061] Preferably, step S2 comprises: mixing the anisole derivative generated in step 1 with 2-bromoisobutyryl bromide, then adding a Lewis acid organic solution dropwise at -30°C to 0°C (preferably -10°C), after the dropwise addition is completed, place it at room temperature, react for 12h to 14h.

[0062] Preferably, the Lewis acid in step S2 is selected from aluminum trichloride, iron trichloride or zinc chloride, preferably aluminum trichloride.

[0063] Preferably, the organic solvent 2 in the Lewis acid organic solution is selected from one of n-hexane, tetrahydrofuran, toluene, xylene, dichloromethane, preferably dichloromethane.

[0064] Preferably, step S3 comprises: dissolving the cyclization product obtained in step S2 in organic solvent 3, adding brominating reagent 1 dropwise at -30°C to 10°C, after the dropwise addition is completed, place it at room temperature, react for 4h to 5h. More preferably, brominating reagent 1 is added dropwise at preferably 0°C.

[0065] Preferably, the bromine reagent in step S3 comprises liquid bromine, NBS or DBH, preferably NBS.

[0066] Preferably, the organic solvent 3 in step S3 is selected from tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide or acetonitrile; preferably N,N-dimethylformamide.

[0067] Preferably, the palladium catalyst in step S4 is selected from palladium acetate, palladium tetra-triphenylphosphine, palladium dichlorobistriphenylphosphine or bis(tri-tert-butylphosphine)palladium, preferably palladium tetra-triphenylphosphine.

[0068] Preferably, the basic reagent 1 in step S4 is selected from sodium carbonate, potassium carbonate, potassium phosphate, potassium hydroxide or sodium hydroxide, preferably potassium carbonate.

[0069] Preferably, the temperature of the Suzuki coupling reaction in step S4 is 80°C to 140°C, preferably 120°C.

[0070] Preferably, the time of the Suzuki coupling reaction in step S4 is 10h to 14h.

[0071] Preferably, the Suzuki coupling reaction in step S4 is carried out in the presence of an organic solvent 4, and the organic solvent 4 is selected from tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, ethyleneglycol dimethyl ether, toluene, xylene, preferably toluene.

[0072] Preferably, step S5 comprises: dissolving the coupling derivative obtained in step S4 in an organic solvent 5, adding a reducing agent under the condition of -30°C to 10°C, and after the reducing agent is completely dissolved, placing it under the condition of room temperature, and reacting for 2h to 3h. More preferably, the reducing agent is added under the condition of -10°C.

[0073] Preferably, the reducing agent in step S5 is selected from lithium aluminum hydride, sodium borohydride, borane tetrahydrofuran complex or diisobutylaluminum hydride, preferably lithium aluminum hydride.

[0074] Preferably, the organic solvent 5 in step S5 is selected from tetrahydrofuran, 2-methyltetrahydrofuran, methyl tert-butyl ether or 1,4-dioxane, preferably tetrahydrofuran.

[0075] Preferably, the eliminating agent in step S6 is selected from p-toluenesulfonic acid, p-toluenesulfonic acid pyridine salt or pyridine hydrochloride, preferably p-toluenesulfonic acid.

[0076] Preferably, the eliminating reaction in step S6 is carried out in an organic solvent 6, and the organic solvent 6 is selected from toluene, xylene, tetrahydrofuran or 1,4-dioxane, preferably toluene.

[0077] Preferably, the temperature of the eliminating reaction in step S6 is 80°C to 120°C, preferably 100°C.

[0078] As an example, the preparation route of the intermediate 1 with the structure shown in formula A1 is as follows:

[0079] .

[0080] Preferably, the preparation method of the intermediate 2 with the structure shown in formula B comprises the following steps:

[0081] S7, subjecting 2-methylpyrrole to a nucleophilic substitution reaction with (trimethylsily)ethoxymethyl chloride under the condition of a strong base reagent 2 to obtain an alkylated derivative.

[0082] S8, subjecting the alkylated derivative obtained in step (S7) to a bromination reaction with a bromination reagent 2 to obtain a brominated intermediate.

[0083] S9, subjecting the brominated intermediate obtained in step (S8) to a cyclization reaction with 2-bromoisobutyryl bromide reagent in the presence of a Lewis acid to obtain a cyclized intermediate.

[0084] S10, subjecting the cyclized intermediate obtained in step (S9) to a Suzuki coupling reaction with R5B(OH)2 in the presence of a palladium catalyst and a basic reagent 2 to generate a coupling product.

[0085] S11, subjecting the coupling product obtained in step (S10) to a reduction reaction with a reducing agent to generate a reduction product.

[0086] S12, subjecting the reduction product obtained in step (S11) to an elimination reaction with an acidic elimination reagent to eliminate the hydroxyl group to obtain a dehydrated compound.

[0087] S13, subjecting the dehydrated product obtained in step (S12) to a removal reaction with a removal reagent to remove the hydroxyl group to obtain an intermediate 2 with a structure shown in Formula B.

[0088] Preferably, in step S7, the strong base reagent 2 is selected from n-butyllithium, sodium hydride, potassium hexamethyldisilazide, and preferably sodium hydride.

[0089] Preferably, in step S7, the temperature of the nucleophilic substitution reaction is 0°C to 30°C, and preferably 20°C.

[0090] Preferably, in step S7, the nucleophilic substitution reaction is carried out under the condition of an organic solvent 7, and the organic solvent 7 is selected from one of N,N-dimethylformamide, tetrahydrofuran, dimethyl sulfoxide, dichloromethane, and preferably tetrahydrofuran.

[0091] Preferably, step S8 includes dissolving the alkylated derivative obtained in step (S7) in an organic solvent 8, adding the bromination reagent 2 dropwise at -30°C to 10°C, and after the dropwise addition is completed, placing it under room temperature conditions for 4h to 5h. More preferably, the bromination reagent 2 is added dropwise at 0°C.

[0092] Preferably, in step S8, the bromination reagent 2 is selected from liquid bromine, NBS, or DBH, and preferably NBS.

[0093] Preferably, the organic solvent 8 in step S8 is selected from tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide or acetonitrile; preferably N,N-dimethylformamide.

[0094] Preferably, step S9 comprises: mixing the bromo intermediate obtained in step (S8) with 2-bromoisobutyryl bromide reagent, then adding dropwise a Lewis acid organic solution at -30℃~0℃, and after the dropwise addition is completed, placing at room temperature for 12h~14h. More preferably, the Lewis acid organic solution is added dropwise at -10℃.

[0095] Preferably, the Lewis acid in step S9 is selected from aluminum trichloride, iron trichloride, zinc chloride, preferably aluminum trichloride.

[0096] Preferably, in step S9, the organic solvent 9 in the Lewis acid organic solution is selected from n-hexane, tetrahydrofuran, toluene, xylene or dichloromethane, preferably dichloromethane.

[0097] Preferably, the palladium catalyst in step S10 is selected from palladium acetate, palladium tetraphenylphosphine, palladium dichlorodiphenylphosphine or bis(tri-tert-butylphosphine)palladium.

[0098] Preferably, the basic reagent 2 in step S10 is selected from sodium carbonate, potassium carbonate, potassium phosphate, potassium hydroxide or sodium hydroxide, preferably potassium carbonate.

[0099] Preferably, the Suzuki coupling reaction in step S10 is carried out in an organic solvent 10 selected from tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, toluene or xylene, preferably toluene.

[0100] Preferably, the temperature of the Suzuki coupling reaction in step S10 is 80℃~140℃, preferably 120℃.

[0101] Preferably, the reaction conditions of the reduction reaction in step S11 are consistent with those of step S5, which will not be repeated here.

[0102] Preferably, the reaction conditions of the elimination reaction in step S12 are consistent with those of step S6, which will not be repeated here.

[0103] Preferably, the removing agent in step S13 is selected from tetra-n-butylammonium fluoride, pyridine trifluoride or trimethylsilyl tetrafluoride ammonium, preferably tetra-n-butylammonium fluoride.

[0104] Preferably, the removing reaction in step S13 is carried out in an organic solvent 11 selected from tetrahydrofuran, 1,4-dioxane, dichloromethane, preferably tetrahydrofuran.

[0105] Preferably, the temperature of the removal reaction in step S13 is 0-30℃, preferably 20℃.

[0106] As an example, the preparation method route of intermediate 2 with the structure as shown in formula B is as follows:

[0107] .

[0108] Based on one general inventive concept, the application further provides an application of a supported metallocene catalyst in preparing polyethylene wax through polymerization reaction of ethylene and hydrogen.

[0109] Preferably, the temperature of the polymerization reaction is 0-100℃.

[0110] Preferably, the ethylene partial pressure in the polymerization reaction system is 0.1-10 MPa.

[0111] Preferably, the hydrogen partial pressure is 1%-5% of the total pressure of the reaction system.

[0112] Preferably, during the polymerization reaction, the residence time of the supported metallocene catalyst is 0.5-10 h.

[0113] Preferably, the molecular weight of the polyethylene wax is 500-3000. As an example, the molecular weight of the polyethylene wax can be 500, 700, 800, 1000, 1100, 1600, 1700, 2000, 2300, 2800, 2900 or 3000. It can also be any value within the range constituted by any two of the above point values as end values.

[0114] Preferably, the molecular weight distribution of the polyethylene wax is ≤1.5. As an example, the molecular weight distribution of the polyethylene wax can be 1.5, 1.4, 1.3, 1.25, 1.2, 1.1 or 1, and can also be other values within the above range. It can also be any value within the range constituted by any two of the above point values as end values.

[0115] Compared with the prior art, the technical scheme of the application has the following beneficial effects:

[0116] On the main catalyst, the metallocene compound with the structure shown in general formula (I) is provided, the strong electron donor in the ligand such as methyl, methoxy, etc. can improve the hydrogen resistance of the metallocene, enhance the stability of the catalyst, at the same time, the introduction of larger steric hindrance groups such as tert-butyl, aromatic groups reduces the attack of hydrogen on the catalyst, improves the hydrogen tolerance, prevents the catalyst from being poisoned and maintains high activity. The nitrogen atom can increase the electron density of the metal center, strengthen the interaction with ethylene, accelerate the monomer insertion rate, and also can fine-tune the electron cloud density of the metal center, reduce the coordination energy barrier of hydrogen molecules, and effectively reduce the molecular weight of polyethylene wax. The suitable ligand steric hindrance makes the polymerization process mainly based on β-H elimination, and the molecular weight distribution of the product is relatively narrow.

[0117] On the other hand, the aluminum-doped modified silica gel as the carrier can enhance the activation efficiency of the metallocene, optimize the interaction between the carrier and the metallocene, improve the dispersion of the metallocene on the carrier, and to a certain extent, improve the polymerization activity and the molecular weight distribution of the product.

[0118] By using the above metallocene compound with a specific structure as the main catalyst and synergistically loading the cocatalyst on the silica gel carrier, the formed supported metallocene catalyst has good stability to hydrogen and shows high ethylene absorption rate, high polymerization activity, and can prepare low molecular weight polyethylene wax with narrow molecular weight distribution under low hydrogen partial pressure. BRIEF DESCRIPTION OF DRAWINGS

[0119] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0120] Figure 1 The nuclear magnetic resonance hydrogen spectrum of the catalyst D1 prepared for example 1.

[0121] Figure 2 The nuclear magnetic resonance carbon spectrum of the catalyst D1 prepared for example 1. DETAILED DESCRIPTION

[0122] The embodiments described in the specification are only for the purpose of explaining the present application, and are not intended to limit the present application.

[0123] For simplicity, only some numerical ranges are explicitly recited herein. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with other lower limits to form a range not explicitly recited, as can any upper limit be combined with any other upper limit to form a range not explicitly recited. Moreover, although not explicitly recited, every point or individual number within a range is included in that range. Thus, every point or individual number can serve as its own lower or upper limit to, in combination with, any other point or individual number or in combination with other lower or upper limits to form a range not explicitly recited.

[0124] Various embodiments of the application can exist in a range format; it should be understood that the description in range format is merely for convenience and brevity and should be taken in its entirety to describe all possible sub-ranges and individual numbers within that range. For example, a range of from 1 to 6 should be read to include the end points 1 and 6, as well as any single number between 1 and 6, for example, 1, 2, 3, 4, 5, and 6. The same applies to ranges describing fractions. Whenever a numerical range is indicated, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrase "range / form" means a range of values, and, where so used, includes fractional values within the indicated range, as well as the integers as if such integers were individually denoted by limiting language such as "from X to Y," where X and Y represent specific integer values. Also, the phrases "ranging / range" are used "from" and "to" means "from and including" the number or point before "from" and "to" the number or point after "to."

[0125] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0126] The term "aryl" refers to a closed aromatic ring or ring system. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, phenanthryl, anthryl, biphenylyl (including bisphenyl, trisphenyl), triphenylenyl, pyrenyl, spirobifluorenyl, perylenyl, indenyl, azulenyl, and benzophenanthryl. In various embodiments, a C6-C30 aryl group, i.e., an aryl group, can contain from 6 to 30 carbons used to form the ring.

[0127] In the present application, "alkyl" can mean straight chain, branched chain and / or cyclic alkyl. The number of carbons of alkyl can be 1 to 50, 1 to 30, 1 to 20, 1 to 10 or 1 to 6. A phrase comprising this term, for example, "C1-C9 alkyl" means alkyl comprising 1 to 9 carbon atoms, and each occurrence thereof can be independently C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl or C9 alkyl. Non-limiting examples of alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, isobutyl, 2-ethylbutyl, 3,3 dimethylbutyl, n-pentyl, isopentyl, neopentyl, t-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-t-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethyl, heptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, t-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethyihexadecyl, 2-butyihexadecyl, 2-hexyihexadecyl, 2-octyihexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyileicosyl, 2-hexyleicosyl, 2-octyleicosyl, n-uneicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, n-triacontyl, adamantyl, and the like.

[0128] The term "alkoxy" refers to a group of the structure "-O-alkyl", i.e., an alkyl group as defined above attached to another group through an oxygen atom. Suitable examples of a phrase comprising this term include, but are not limited to: methoxy (-O-CH3 or -OMe), ethoxy (-O-CH2CH3 or -OEt), and t-butoxy (-O-C(CH3)3 or -OtBu).

[0129] In the present application, when a connecting site is not specified in a group, it means that an optional connectable site in the group is a connecting site.

[0130] In the present application, when a fused site is not specified in a group, it means that an optional fusible site in the group is a fused site, and preferably two or more sites in the group in ortho position are fused sites.

[0131] In the present application, when a same group contains multiple substituents with the same symbol, each substituent can be the same as or different from each other, for example, 6 R on the benzene ring can be the same as or different from each other.

[0132] The following abbreviations can be used herein: TBAF is tetrabutylammonium fluoride, PhB(OH)2 is phenylboronic acid, Pd(PPh3)4 is palladium tetrakis(triphenylphosphine), LiAlH4 is lithium aluminum hydride, THF is tetrahydrofuran, TsOH is p-toluenesulfonic acid, Tol is toluene, SEMCl is 2-(trimethylsilyl)ethoxymethyl chloride.

[0133] The present application is further illustrated by the following examples. It is to be understood that these examples are merely illustrative of specific embodiments of the application and that various modifications and changes can be made by those skilled in the art within the scope of the present application. Unless otherwise stated, all parts, percentages and ratios reported herein are based upon the weight, and all reagents used in the examples are commercially available or synthesized by conventional methods and used without further purification, and the instruments used in the examples are commercially available.

[0134] Example 1

[0135] (1) Synthesis of A1 intermediate according to the following route:

[0136] S1, Synthesis of 2-tert-butyl-1-methoxybenzene

[0137]

[0138] Reaction: 140.06 g of KOH (2.5 mol) was mixed with 1.5 L of THF, then 150 g (1 mol) of 2-tert-butylphenol was added dropwise into the mixture of KOH and THF at 0°C, with vigorous stirring, and after the dropwise addition was completed, the temperature was allowed to rise to room temperature naturally, and the reaction was carried out for 12 h; 212.91 g (1.5 mol) of iodomethane was added dropwise into the above mixture at 0°C, with vigorous stirring, and after the dropwise addition was completed, the temperature was allowed to rise to room temperature naturally, and the reaction was carried out for 12 h.

[0139] Work-up: sufficient deionized water was added for extraction, and the pH was adjusted to neutral using dilute hydrochloric acid, then sufficient anhydrous sodium sulfate was added for drying, and the solvent was removed by rotary evaporation, finally obtaining the product 159 g with a yield of 97%.

[0140] S2, Synthesis of 5-tert-butyl-6-methoxy-2-methyl-1-indanone

[0141]

[0142] Reaction: 137g (0.59mol) of 5-tert-butyl-6-methoxy-2-methyl-1-indanone was mixed with 1.5L of DMF, 115.45g (0.65mol) of NBS was added dropwise into the above solution at 0°C, with vigorous stirring, after the addition was completed, the natural temperature was raised to room temperature, and the reaction was carried out for 4h.

[0143] Post-processing: quench at -30°C with ice deionized water, add enough deionized water for extraction, and adjust the pH to neutral with saturated sodium bicarbonate solution, then add enough anhydrous sodium sulfate to remove water, and finally remove the solvent by rotary evaporation to obtain the product 137g with a yield of 61%.

[0144] S3, synthesis of 4-bromo-5-tert-butyl-6-methoxy-2-methyl-1-indanone

[0145]

[0146] Reaction: 137g (0.59mol) of 5-tert-butyl-6-methoxy-2-methyl-1-indanone was mixed with 1.5L of DMF, 115.45g (0.65mol) of NBS was added dropwise into the above solution at 0°C, with vigorous stirring, after the addition was completed, the natural temperature was raised to room temperature, and the reaction was carried out for 4h.

[0147] Post-processing: add enough sodium sulfite solution, stir until the solution fades, add enough deionized water for extraction, and adjust the pH to neutral with saturated sodium bicarbonate solution, add enough anhydrous sodium sulfate to remove water, and finally remove the solvent by rotary evaporation to obtain the product 165g with a yield of 90%.

[0148] S4, synthesis of 5-tert-butyl-4-phenyl-6-methoxy-2-methyl-1-indanone

[0149]

[0150] Reaction: 165g (0.53mol) of 4-bromo-5-tert-butyl-6-methoxy-2-methyl-1-indanone, 146.54g (1.06mol) of K2CO3, 71.11g (0.58mol) of phenylboronic acid, 6.13g (5.30mmol) of tetrakis(triphenylphosphine)palladium and 1.5L of toluene were mixed uniformly, and the reaction was carried out at 120°C under condensation reflux for 12h.

[0151] Post-processing: add enough deionized water for extraction, and adjust the pH to neutral with dilute hydrochloric acid, add enough anhydrous sodium sulfate to remove water, and finally remove the solvent by rotary evaporation to obtain the product 152g with a yield of 93%.

[0152] S5, Synthesis of 5-tert-butyl-4-phenyl-6-methoxy-2-methyl-l-indanone

[0153]

[0154] Reaction: 152 g (0.49 mol) of 5-tert-butyl-4-phenyl-6-methoxy-2-methyl-l-indanone was mixed with 1.5 L of THF, 9.35 g (0.25 mol) of LiAlH4was added at -10 °C, the temperature was maintained until the dissolution was completed with vigorous stirring, after dissolution, the temperature was naturally increased to room temperature, and the reaction was allowed to proceed for 2 h.

[0155] Post-treatment: ice deionized water was added at -30 °C for quenching, enough deionized water was added for extraction, dilute hydrochloric acid was used to adjust the pH to neutral, then enough anhydrous sodium sulfate was added for water removal, and the solvent was removed by rotary evaporation, finally 150 g of product was obtained with a yield of 98%.

[0156] S6, Synthesis of 5-tert-butyl-4-phenyl-6-methoxy-2-methyl-l-indanone

[0157]

[0158] Reaction: 150 g (0.48 mol) of 5-tert-butyl-4-phenyl-6-methoxy-2-methyl-l-indanone, 16.64 g (0.097 mol) of p-toluene sulfonate, 1.5 L of toluene were mixed uniformly, and the reaction was condensed and refluxed at 100 °C for 12 h.

[0159] Post-treatment: enough deionized water was added for extraction, water washing was performed until neutral, enough anhydrous sodium sulfate was added for water removal, the solvent was removed by rotary evaporation, and column chromatography was used for separation to obtain 108 g of product with a yield of 76%.

[0160] (2) The B1 intermediate was synthesized according to the following route:

[0161] S7, Synthesis of 1-(trimethylsilyl)ethoxymethyl-2-methylpyrrole

[0162]

[0163] Reaction: 80 g (1 mol) of 2-methylpyrrole, 35.5 g (1.5 mol) of sodium hydride, and 0.8 L of THF were mixed uniformly, 180.86 g (1.1 mol) of (trimethylsilyl)ethoxymethyl chloride was slowly added at 20 °C, and the reaction temperature was maintained for 12 h.

[0164] Work-up: quench with ice deionized water at -30 °C, extract with enough deionized water, wash with water until neutral, then add enough anhydrous sodium sulfate to remove water, and finally remove the solvent by rotary evaporation to obtain the product 188 g with a yield of 90%.

[0165] S8, Synthesis of 1-(trimethylsilyl)ethoxymethyl-2-methyl-3-bromopyrrole

[0166]

[0167] Reaction: mix 188 g (0.90 mol) of 1-(trimethylsilyl)ethoxymethyl-2-methylpyrrole with 1.8 L of DMF, and then add 174.13 g (0.99 mol) of NBS dropwise into the above solution while stirring vigorously, and then naturally warm to room temperature after the dropwise addition is completed, and then react for 4 h.

[0168] Work-up: add enough sodium sulfite solution, stir until the solution fades, extract with enough deionized water, adjust the pH to neutral with saturated sodium bicarbonate solution, add enough anhydrous sodium sulfate to remove water, and finally remove the solvent by rotary evaporation to obtain the product 220 g with a yield of 85%.

[0169] S9, Synthesis of 1-(trimethylsilyl)ethoxymethyl-2,5-dimethyl-3-bromopyrrolocinone

[0170]

[0171] Reaction: mix 220 g (0.76 mol) of 1-(trimethylsilyl)ethoxymethyl-2,5-dimethyl-3- bromopyrrole with 191.66 g (0.83 mol) of 2-bromoisobutyryl bromide, and then add 202.1 g (1.52 mol) of AlCl3 dissolved in 2.2 L of DCM dropwise into the solution at -10 °C while stirring vigorously, and then naturally warm to room temperature after the dropwise addition is completed, and then react for 12 h.

[0172] Work-up: quench with ice deionized water at -30 °C, extract with enough deionized water, adjust the pH to neutral with saturated sodium bicarbonate solution, then add enough anhydrous sodium sulfate to remove water, and finally remove the solvent by rotary evaporation to obtain the product 172 g with a yield of 63%.

[0173] S10, Synthesis of 1-(trimethylsilyl)ethoxymethyl-2,5-dimethyl-3-phenylpyrrolocinone

[0174]

[0175] Reaction: 173 g (0.48 mol) of 1- (trimethylsilyl) ethoxymethyl-2, 5-dimethyl-3- bromopyrrolocyclopentenone, 132.67 g (0.96 mol) of K2CO3, 64.38 g (0.53 mol) of phenylboronic acid, 5.55 g (4.8 mmol) of tetrakis (triphenylphosphine) palladium and 1.7 L of toluene were mixed uniformly, and the reaction was performed under reflux condensation at 120°C for 12 h.

[0176] Post-treatment: A sufficient amount of deionized water was added for extraction, and dilute hydrochloric acid was used to adjust the pH to neutral. A sufficient amount of anhydrous sodium sulfate was added to remove water, and the solvent was removed by rotary evaporation. Finally, 157 g of product was obtained with a yield of 92%.

[0177] S11, Synthesis of 1- (trimethylsilyl) ethoxymethyl-2, 5-dimethyl-3-phenylpyrrolocyclopentenol

[0178]

[0179] Reaction: 157 g (0.44 mol) of 1- (trimethylsilyl) ethoxymethyl-2, 5-dimethyl-3- phenylpyrrolocyclopentenone and 1.6 L of THF were mixed uniformly, and 8.38 g (0.22 mol) of LiAlH4 was added at -10°C. The temperature was maintained until dissolution with vigorous stirring. After dissolution, the temperature was naturally increased to room temperature, and the reaction was performed for 2 h.

[0180] Post-treatment: Ice deionized water was added at -30°C for quenching, a sufficient amount of deionized water was added for extraction, and dilute hydrochloric acid was used to adjust the pH to neutral. Subsequently, a sufficient amount of anhydrous sodium sulfate was added to remove water, and the solvent was removed by rotary evaporation. Finally, 150 g of product was obtained with a yield of 96%.

[0181] S12, Synthesis of 1- (trimethylsilyl) ethoxymethyl-2, 5-dimethyl-3-phenylpyrrolocyclopenta-2, 4-diene

[0182]

[0183] Reaction: 150 g (0.42 mol) of 1- (trimethylsilyl) ethoxymethyl-2, 5-dimethyl-3- phenylpyrrolocyclopentenol, 14.45 g (0.084 mol) of p-toluenesulfonate, and 1.5 L of toluene were mixed uniformly, and the reaction was performed under reflux condensation at 100°C for 12 h.

[0184] Post-treatment: A sufficient amount of deionized water was added for extraction, and the water was washed to neutral. A sufficient amount of anhydrous sodium sulfate was added to remove water, and the solvent was removed by rotary evaporation. Column chromatography was used to separate the product, and 103 g of product was obtained with a yield of 72%.

[0185] S13, 2, 5-dimethyl-3-phenylpyrrolocyclopenta-2, 4-diene

[0186]

[0187] Reaction: 103 g (0.44 mol) of 1-(trimethylsilyl)ethoxymethyl-2,5-dimethyl-3-phenylpyrrolocyclopentadiene was thoroughly mixed with 1.0 L of THF, and 95.18 g (0.36 mol) of tetrabutylammonium fluoride was added at 20 °C with vigorous stirring during the reaction for 2 h.

[0188] Post-processing: Quench with ice water at -10℃, extract with sufficient deionized water, adjust pH to neutral with dilute hydrochloric acid, then add sufficient anhydrous sodium sulfate to remove water, remove solvent by rotary evaporation, and finally obtain 57g of product with a yield of 90%.

[0189] (3) Synthesize catalyst D1 according to the following route:

[0190] Synthesis of S14, 5-tert-butyl-4-phenyl-6-methoxy-2-methyl-1-indene

[0191]

[0192] Reaction: 50 g (0.16 mol) of 5-tert-butyl-4-phenyl-6-methoxy-2-methyl-1-indene was dissolved in 0.5 L of THF, and 68.5 mL of n-butyllithium (2.5 M 0.17 mol) was added dropwise at -78 °C with thorough stirring. After the addition was complete, the mixture was allowed to rise to room temperature and reacted for 12 h. 31.58 g (0.24 mol) of dichlorodimethylsilane was added at -78 °C with thorough stirring. After the addition was complete, the mixture was allowed to rise to room temperature and reacted for 12 h.

[0193] Post-processing: Quench with ice water at -10℃, extract with sufficient deionized water, adjust pH to neutral with saturated sodium bicarbonate, then remove water with sufficient anhydrous sodium sulfate, remove solvent by rotary evaporation, and finally obtain 58g of product with a yield of 89%.

[0194] Synthesis of S15, dimethylsilyl (5-tert-butyl-4-phenyl-6-methoxy-2-methyl-1-indene) (2,5-dimethyl-3-phenylpyrrolocyclopentadiene)

[0195]

[0196] Reaction: 49 g (0.088 mol) of dimethylsilicon (5-tert-butyl-4-phenyl-6-methoxy-2-methyl-1-indene) (2,5-dimethyl-3-phenyl pyrrolocyclopenta-diene) was dissolved in 1.0 L of diethyl ether, 35.2 mL of n-butyllithium (2.5 M, 0.088 mol) was added dropwise at 0 °C, and the mixture was stirred thoroughly during the addition. After the addition was completed, the mixture was allowed to warm to room temperature and reacted for 12 h. Then, 22.05 g (0.088 mol) of anhydrous neodymium chloride was added at 0 °C, and the mixture was stirred thoroughly during the addition. After the addition was completed, the mixture was allowed to warm to room temperature and reacted for 12 h.

[0197] Work-up: The reaction was quenched with ice water at -10 °C, and the mixture was extracted with a sufficient amount of deionized water. The pH was adjusted to neutral with saturated sodium bicarbonate, and then the mixture was dehydrated with a sufficient amount of anhydrous sodium sulfate. The solvent was removed by rotary evaporation, and the product was purified by column chromatography to obtain 49 g of the product at a yield of 61%.

[0198] S16, Synthesis of dimethylsilicon (5-tert-butyl-4-phenyl-6-methoxy-2-methyl-1-indene) (2,5-dimethyl-3-phenyl pyrrolocyclopenta-diene) neodymium chloride

[0199]

[0200] Reaction: 49 g (0.088 mol) of dimethylsilicon (5-tert-butyl-4-phenyl-6-methoxy-2-methyl-1-indene) (2,5-dimethyl-3-phenyl pyrrolocyclopenta-diene) was dissolved in 1.0 L of diethyl ether, 35.2 mL of n-butyllithium (2.5 M, 0.088 mol) was added dropwise at 0 °C, and the mixture was stirred thoroughly during the addition. After the addition was completed, the mixture was allowed to warm to room temperature and reacted for 12 h. Then, 22.05 g (0.088 mol) of anhydrous neodymium chloride was added at 0 °C, and the mixture was stirred thoroughly during the addition. After the addition was completed, the mixture was allowed to warm to room temperature and reacted for 12 h.

[0201] Work-up: The reaction was quenched with ice water at -10 °C, and the mixture was extracted with a sufficient amount of deionized water. The pH was adjusted to neutral with saturated sodium bicarbonate, and then the mixture was dehydrated with a sufficient amount of anhydrous sodium sulfate. The solvent was removed by rotary evaporation, and the product was purified by column chromatography to obtain 49 g of the product at a yield of 61%.

[0202] Figure 1 Figure 1 is a nuclear magnetic resonance hydrogen spectrum of the metallocene compound D1, in which the abscissa PPM in the graph indicates a nuclear magnetic chemical shift. The nuclear magnetic data of the metallocene compound D1 are as follows: Figure 2 Figure 2 is a carbon spectrum of the metallocene compound D1, in which the abscissa PPM in the graph indicates a nuclear magnetic chemical shift. The nuclear magnetic data of the metallocene compound D1 are as follows: 1 H NMR (400 MHz, CDCl3): δ (ppm) 7.41-7.51 (m, 10H), 7.3 (s, 1H), 6.36 (s, 1H), 6.13 (s, 1H), 3.91 (s, 3H), 2.52 (s, 3H), 1.77 (s, 6H), 1.40 (s, 9H), 0.21 (s, 6H).

[0203] The carbon spectrum data are as follows: 13 C NMR (100 MHz, CDCl3): δ (ppm) 154.5, 137.1, 136.6, 136.5, 132.4, 132.3, 131.1, 131.0, 129.0, 128.5, 127.8, 127.4 , 127.4, 127.0, 126.0, 125.7, 124.0, 121.0, 119.4, 106.0, 56.6, 37.3, 36.2, 31.8, 29.5, 25.9, 12.0, -2.9.

[0204] (4) Preparation of modified silica gel:

[0205] Grace 2408D silica gel was dispersed in ethanol / deionized water (volume ratio 1:3), the pH was adjusted to 4 with hydrogen chloride, and then aluminum chloride solution was added to control the Si / Al molar ratio to 100:1. The mixture was stirred at 60℃ for 24 h, filtered, washed, dried, and calcined at 600℃ for 4 h to obtain modified silica gel.

[0206] (5) Preparation of supported metallocene catalysts:

[0207] Modified silica gel was added to a toluene solution of methylaluminoxane, heated to 60°C, and stirred for 24 h. The mixture was then filtered, washed with n-hexane, and dried under vacuum to obtain a supported catalyst. The supported catalyst was then added to a toluene solution of metallocene compound D1, heated to 70°C, and stirred for 24 h. The mixture was then filtered, washed with n-hexane, and dried under vacuum to obtain a supported metallocene catalyst K1. The mass ratio of the modified support to the metallocene catalyst D1 was 50:1, and the molar ratio of aluminum in the methylaluminoxane to the molar ratio of rare earth metal Nd in the metallocene catalyst D1 was 100:1.

[0208] Example 2

[0209] The preparation method in this embodiment is basically the same as that in Example 1, except that R2 and R5 in the structure of the metallocene compound D2 prepared in this embodiment are both 4-tert-butylphenyl. The supported metallocene catalyst prepared in Example 2 is K2.

[0210] Example 3

[0211] The preparation method in this embodiment is basically the same as that in Example 1, except that step (4) is omitted and the silica support is not modified; Grace 2408D silica is used directly. The supported metallocene catalyst prepared in Example 3 is K3.

[0212] Comparative Example 1

[0213] The preparation method of the present comparative example is basically the same as that of Example 1, except that the main catalyst metallocene compound used in the present comparative example is E1. The supported metallocene catalyst prepared in Comparative Example 1 is M1.

[0214] The structures of D1-D2 and E1 of the metallocene compounds prepared in each example and comparative example are shown as follows:

[0215] 、 、 .

[0216] Application Example:

[0217] Application Example 1

[0218] The polymerization experiment was carried out in a 2L high-pressure steel autoclave. The reactor was purged with high-purity nitrogen for 1h, 1L of hexane was added, and the stirring was started. Then 5mL of 1mol / L TIBA toluene solution was added, and stirred for 5min. Then 25mg of the supported metallocene catalyst prepared in Example 1 was added, and hydrogen was added to make the pressure in the reactor 0.01MPa. Then ethylene was introduced to maintain the pressure in the reactor at 1Mpa. The temperature was raised to 80℃ and the reaction was carried out for 1h. During the reaction, ethylene was supplemented to maintain the pressure at 1Mpa.

[0219] Application Examples 2-5

[0220] The preparation method of Application Examples 2-5 is basically the same as that of Application Example 1, except that the amount of hydrogen added is different. Specifically, the amount of hydrogen added in each application example is as follows:

[0221] Application Example 2: hydrogen was added to make the pressure in the reactor 0.02MPa, and the other conditions were the same as in Example 1.

[0222] Application Example 3: hydrogen was added to make the pressure in the reactor 0.03MPa, and the other conditions were the same as in Example 1.

[0223] Application Example 4: hydrogen was added to make the pressure in the reactor 0.04MPa, and the other conditions were the same as in Example 1.

[0224] Application Example 5: hydrogen was added to make the pressure in the reactor 0.05MPa, and the other conditions were the same as in Example 1.

[0225] Application Example 6

[0226] The preparation method of Application Example 6 is basically the same as that of Application Example 1, except that the catalyst used in the present application example is K2.

[0227] Application Example 7

[0228] The preparation method of Application Example 7 is basically the same as that of Application Example 1, except that the catalyst used in the present application example is K3.

[0229] Example 8

[0230] The preparation method of Example 8 is basically the same as that of Example 1, except that the catalyst used in this example is M1.

[0231] Performance test:

[0232] The polymerization activity of the supported metallocene catalyst is the ratio of the mass of the polymerization product obtained per unit time to the molar amount of the metallocene used, representing the polymerization activity of the catalyst, with the unit g.PE / mol.M·h.

[0233] Number average molecular weight (Mn) and weight average molecular weight (Mw): The number average molecular weight (Mn) and weight average molecular weight (Mw) of the polyethylene wax prepared in each example were tested according to the method specified in the high temperature gel permeation chromatography method (ASTM D5296).

[0234] Molecular weight distribution width: Molecular weight distribution width = Mn / Mw.

[0235] Penetration: The penetration of the polyethylene wax prepared in each example was tested according to the method specified in the standard test method for determining the hardness of paraffin wax (ASTM D1321).

[0236] Melting drop point: The melting drop point of the polyethylene wax prepared in each example was tested according to the method specified in the standard test method for drop point of lubricating grease and petroleum (ASTM D127).

[0237] Density: The density of the polyethylene wax prepared in each example was tested according to the method specified in the standard test method for determining the density and specific gravity of plastics by displacement (ASTM D792).

[0238] The performance data of the polyethylene wax prepared in each example are shown in Table 1 below.

[0239] Table 1 Performance parameters of polyethylene wax prepared in each example

[0240]

[0241] From the data in Table 1, it can be seen that catalyst K1 can catalyze the preparation of low molecular weight polyethylene wax with narrow molecular weight distribution under low hydrogen partial pressure conditions (1%~5%), and its polymerization activity is higher and its properties are more stable compared with metallocene bis(indenyl)zirconium dichloride (M1); catalyst K2 prepared by changing the R2, R5 groups of the metallocene catalyst to 4-tert-butylphenyl also shows similar effects to K1, and this metallocene structure can be modified to develop a series of polyethylene wax metallocene grades; by comparing catalyst K1 with K3, the catalyst obtained by using aluminum doping to prepare a modified carrier has improved polymerization activity and product molecular weight distribution due to the carrier loading effect.

[0242] The above description is provided as an enabling teaching of the application and is not intended to limit its scope in any way. Any modification of the application in keeping with the spirit thereof that is apparent to those skilled in the art is to be considered within the scope of the application as defined by the appended claims.

Claims

1. A supported metallocene catalyst for the synthesis of polyethylene wax, characterized in that, It includes a support, a main catalyst, and a co-catalyst; the main catalyst comprises a metallocene compound having at least one structure shown in formulas D1 and D2. ， ， The cocatalyst is a C1-C12 alkylaluminum or alkylaluminoxane; The carrier is selected from silica gel.

2. The supported metallocene catalyst according to claim 1, characterized in that, The co-catalyst is selected from trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, methylaluminoxane, or isobutylaluminoxane.

3. The supported metallocene catalyst according to claim 1, characterized in that, The molar ratio of aluminum in the co-catalyst to the rare earth metal in the metallocene compound is (50~1000):

1.

4. The supported metallocene catalyst according to claim 1, characterized in that, The mass ratio of the support to the main catalyst is (10~200):

1.

5. The supported metallocene catalyst according to claim 1, characterized in that, The carrier is modified silica gel, and the preparation method of the modified silica gel includes the following steps: The silica gel is dispersed in a solvent, and hydrogen chloride is added to adjust the pH of the system to 1-4. Then, an aluminum source is added, and the molar ratio of silicon in the silica gel to aluminum in the aluminum source is controlled to be (20-200):

1. The mixture is stirred and reacted at 60-65°C for 20-24 hours. After filtration, washing, and drying, the mixture is finally calcined at 600-650°C for 4-5 hours to obtain the modified silica gel. The solvent is selected from one or more of deionized water, ethanol, and isopropanol; the aluminum source is aluminum chloride, aluminum chloride hexahydrate, or aluminum isopropoxide.

6. The supported metallocene catalyst according to claim 5, characterized in that, The modified silicone meets at least one of the following conditions: (1) The average particle size D50 of the modified silica gel is 10 μm to 100 μm; (2) The specific surface area of ​​the modified silica gel is 200 m². 2 / g~500m 2 / g; (3) The specific pore volume of the modified silica gel is 1cc / g to 3cc / g; (4) The average pore size of the modified silica gel is 10nm~50nm.

7. The method for preparing the supported metallocene catalyst according to any one of claims 1 to 6, characterized in that, Includes the following steps: (a) Providing the metallocene compound, the support, and the cocatalyst, respectively; (b) Dissolve the co-catalyst in a first organic solvent, add the support, heat to 60°C~80°C, and stir for 20h~24h; then filter, wash and vacuum dry in sequence to obtain the co-catalyst supported support; (c) Dissolve the metallocene compound in a second organic solvent, add the catalyst support, heat to 60°C~80°C, and stir for 20h~24h; then filter, wash and vacuum dry in sequence to obtain the supported catalyst.

8. The preparation method according to claim 7, characterized in that, The preparation method of the metallocene compound includes the following steps: (a1) Provide intermediate 1 as shown in Formula A and intermediate 2 as shown in Formula B, respectively; (a2) Dissolve the intermediate 1 in an inert organic solvent 1, and carry out a lithiation reaction by adding an alkyl lithium reagent dropwise at -70℃ to -80℃. After the addition is complete, place the mixture at room temperature and continue the reaction for 12h to 14h. Then, at -70℃ to -80℃, add a halosilane having the structure shown in Formula C dropwise to carry out the first nucleophilic substitution reaction. After the addition is complete, place the mixture at room temperature and continue the reaction for 12h to 14h to obtain a silicon halide-containing intermediate. (a3) Dissolve the silicon halide intermediate obtained in step (a2) in organic solvent 2, and carry out a lithiation reaction by adding alkyl lithium reagent dropwise at -70℃ to -80℃. After the addition is completed, place it at room temperature and continue the reaction for 12h to 14h. Then, carry out a second nucleophilic substitution reaction by adding the intermediate 2 dropwise at -70℃ to -80℃. After the addition is completed, place it at room temperature and continue the reaction for 12h to 14h. Separate and purify to obtain silicon-bridged metallocene ligands. (a4) The silicon-bridged metallocene ligand obtained in step (a3) ​​is dissolved in an inert organic solvent 3. Alkyl lithium is added dropwise at -5℃ to 0℃ to carry out a lithiation reaction. After the addition is completed, the mixture is placed at room temperature for 12h to 14h and the reaction continues for 12h to 14h. Rare earth metal halide is added at -5℃ to 0℃. After the addition is completed, the mixture is placed at room temperature and the reaction continues for 12h to 14h. The mixture is then separated and purified to obtain the metallocene compound. ， ， ， Wherein, R1 is methyl, R2 and R5 are phenyl or 4-tert-butylphenyl, R3 is methyl, R4 is tert-butyl; X is Cl.

9. The application of the supported metallocene catalyst according to any one of claims 1 to 6 in the preparation of polyethylene wax by polymerization of ethylene and hydrogen.

10. The application according to claim 9, characterized in that, The polymerization reaction satisfies at least one of the following conditions: (1) The polymerization reaction temperature is 0~100℃; (2) The partial pressure of ethylene in the polymerization reaction system is 0.1 MPa to 10 MPa; (3) The partial pressure of hydrogen is 1% to 5% of the total pressure of the reaction system; (4) During the polymerization reaction, the residence time of the supported metallocene catalyst is 0.5h to 10h; (5) The molecular weight of the polyethylene wax is 500~3000; (6) The molecular weight distribution of the polyethylene wax is ≤1.5.

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