CN118027112A - Preparation method and application of geometry-limited metallocene catalyst containing phenoxy - Google Patents

Abstract

The present disclosure provides a preparation method and an application of a geometry-limited metallocene catalyst containing phenoxy, wherein the metallocene catalyst has a structure as shown in formula (I) or formula (II), and a metal center connected with the phenoxy structure in the metallocene catalyst forms a bridging structure with a metallocene ring or an indene ring; each X is independently selected from halogen; r ₁、R₂ are each independently selected from phenyl or substituted phenyl; r ₃、R₄、R₅ is independently selected from any one of hydrogen, hydrocarbon group of C ₁～C₁₂ and halogen; r ₆、R₇、R₈、R₉、R₁₀、R₁₁ is each independently selected from any one of hydrogen, C ₁～C₁₂ hydrocarbyl, substituted silicon-based or C ₁～C₁₂ substituted hydrocarbyl.

Description

Preparation method and application of geometry-limited metallocene catalyst containing phenoxy

Technical Field

The disclosure relates to the technical field of catalysts, in particular to a preparation method and application of a geometry-limited metallocene catalyst containing phenoxy, and more particularly relates to a geometry-limited metallocene catalyst containing a large steric hindrance phenoxy for olefin polymerization and copolymerization, and a preparation method and application thereof.

Background

Polyolefin is one of the most widely used high molecular materials with the highest yield, and occupies a very important position in the field of material science. The current global maximum polyolefin production is mainly focused on common low-end varieties, the productivity of low-end polyolefin materials has reached a saturation state, but the production capacity in the field of high-end polyolefin materials is relatively weak, and high-end polyolefin materials such as polyolefin elastomer (POE), cycloolefin copolymer (COC) and the like need to rely on a large amount of import.

Among them, polyolefin elastomer (POE) is a polymer synthesized from ethylene and 1-octene by copolymerization, in which the introduction of alpha-olefin (e.g., 1-octene) is critical to the physical and chemical properties of the polymer. By adding alpha-olefins, the density and crystallinity of the polymer can be effectively reduced, which has a significant effect on improving the flexibility and processability of the material. In addition, the addition proportion of the alpha-olefin can also be used for regulating and controlling the melt index of the polymer, so that the processability of the polyolefin elastomer is convenient to optimize, and the precise regulation of the melt index of the polymer can be realized by precisely controlling the content of the alpha-olefin, so that different processing and application requirements are met. When the insertion ratio of the alpha-olefin reaches a certain threshold, the resulting polymer exhibits typical polyolefin elastomer characteristics. These properties, including excellent elasticity, abrasion resistance, and resistance to environmental influences, make polyolefin elastomers widely used in many industrial and commercial applications.

Polyolefin elastomer (POE) is successfully synthesized by adopting a metallocene catalyst (CGC) limited by geometric configuration at the earliest, has excellent mechanical property, rheological property and ageing resistance, is widely applied to the field of plastic modification, and meanwhile, POE plays an important role in the fields of rubber and thermoplastic elastomer. With the continuous increase of POE demand, the product performance requirement is also continuously improved, but the use of CGC catalyst has a certain limitation in use, firstly, although the geometric configuration limitation endows the CGC catalyst with a certain high temperature resistance, the activity of the CGC catalyst is obviously reduced above 100 ℃, and the CGC catalyst is the highest temperature of the CGC catalyst, so that the CGC catalyst is limited in application in industrial production. Secondly, CGC catalysts are usually co-catalyst with Methylaluminoxane (MAO) as co-catalyst, whereas the production process of MAO is complex, costly and costly.

Therefore, the development of novel catalysts and related catalytic processes for preparing high performance polyolefin materials is of great significance in improving the competitiveness of the high-end polyolefin industry.

Disclosure of Invention

In view of the above, the present disclosure provides a preparation method and application of a constrained metallocene catalyst containing a phenoxy geometry, so as to at least partially solve the above technical problems.

In order to solve the technical problems, the technical scheme provided by the disclosure is as follows:

as a first aspect of the present disclosure, there is provided a metallocene catalyst having a structure as shown in formula (i) or formula (ii):

wherein, the metal center connected with the phenoxy structure in the metallocene catalyst is bridged with the metallocene ring or the indene ring;

Each X is independently selected from halogen;

r ₁、R₂ are each independently selected from phenyl or substituted phenyl;

R ₃、R₄、R₅ is independently selected from any one of hydrogen, hydrocarbon group of C ₁～C₁₂ and halogen;

R ₆、R₇、R₈、R₉、R₁₀、R₁₁ is each independently selected from any one of hydrogen, C ₁～C₁₂ hydrocarbyl, substituted silicon-based or C ₁～C₁₂ substituted hydrocarbyl.

According to embodiments of the present disclosure, substituents in substituted phenyl groups include any one or more of hydroxy, amino, methyl, methoxy;

The substituent in the substituted silicon group comprises any one or more of alkyl, aryl and methoxy;

the substituent of the substituted hydrocarbon group of C ₁～C₁₂ includes any one or more of hydroxyl group, amino group, acyl group and ether group.

As a second aspect of the present disclosure, there is provided a method for preparing a metallocene catalyst, comprising:

From compounds A under inert gas atmosphere Reacting with a compound M ₁-ⁿ Bu and TiX ₄ to obtain a metallocene catalyst with a structure shown in a formula (I);

Or C compound Reacting with a compound B and TiX ₄ to obtain a metallocene catalyst with a structure shown in a formula (II);

Wherein, after the X halogen atom of TiX ₄ is partially substituted in the reaction, the Ti atom is connected with the phenoxy in the A compound or the C compound and forms a bridging structure with the cyclopentadienyl ring or the indenyl ring;

R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁ And X has the same definition as in the metallocene catalysts described above;

m ₁ is independently selected from any one of lithium, sodium, potassium, rubidium and cesium;

ⁿ Bu represents n-butyl.

According to embodiments of the present disclosure, compound a is formed from compound DWith E compoundsObtaining the product through reaction;

or C compound is composed of D compound With F Compounds/>Obtaining the product through reaction;

Wherein ,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁ and X have the same meanings as in the metallocene catalysts described above;

m ₂ is independently selected from any one of lithium, sodium, potassium, rubidium and cesium.

According to embodiments of the present disclosure, the D compound is composed of a B compound and a G compoundAnd H compoundsObtaining the product through reaction;

Wherein R ₁、R₂、R₃、R₄、R₅、M₁、ⁿ Bu has the same definition as the preparation method of the metallocene catalyst;

x ₁ is independently selected from halogen.

According to embodiments of the present disclosure, the H compound is formed from the J compoundReacting with methyl iodide and potassium hydroxide, and converting hydroxyl into methoxy to obtain;

The J compound is composed of K compound With L Compounds/>Performing Friedel-crafts reaction in zinc chloride and concentrated hydrochloric acid solution to obtain the product;

wherein R ₁、R₂、R₃、X₁ has the same definition as the preparation method of the metallocene catalyst.

As a third aspect of the present disclosure there is provided the use of a metallocene catalyst comprising: providing an activated metallocene catalyst; and catalyzing olefin to carry out homo-polymerization reaction or copolymerization reaction by using the activated metallocene catalyst.

According to embodiments of the present disclosure, obtaining an activated metallocene catalyst comprises:

the metallocene catalyst and the alkyl aluminum are mixed in a first organic solvent, and then boron cocatalyst is added for activation.

According to embodiments of the present disclosure, catalyzing an olefin for homo-polymerization or copolymerization using an activated metallocene catalyst includes:

under 160-200 ℃, utilizing the activated metallocene catalyst to carry out homo-polymerization reaction or copolymerization reaction on olefin in a second organic solvent;

the homopolymerization reaction comprises the homopolymerization reaction of catalyzing C2-C6 olefin;

The copolymerization reaction comprises the catalysis of the copolymerization reaction of C2-C6 olefins and C6-C10 olefins.

According to an embodiment of the present disclosure, the first organic solvent includes one or more of toluene, methylene chloride, diethyl ether, tetrahydrofuran, n-hexane, n-heptane;

the second organic solvent comprises any one or more of tetrahydrofuran, n-pentane, n-hexane, n-heptane, petroleum ether, toluene, benzene and methylene dichloride;

the C2-C6 olefins include: any one or more of ethylene, propylene, 1-butene, 1-pentene and 1-hexene;

The C6-C10 olefins include one or more of 1-hexene, 1-octene, and 1-decene.

Based on the technical scheme, the metallocene catalyst, the preparation method and the application thereof provided by the disclosure at least comprise one of the following beneficial effects:

(1) In the embodiments of the present disclosure, by introducing a large sterically hindered phenoxy structure, a bridged structure is formed with the metallocene ring or indene ring, enhancing the steric hindrance effect of the metal center, enabling the metallocene catalyst to withstand higher temperatures, be able to operate stably at higher temperatures (up to 180 ℃), and also providing significant structural adjustability. The polymerization activity and selectivity of the catalyst can be effectively optimized by means of adjusting the specific structure of the metallocene ring and the like.

(2) In embodiments of the present disclosure, the metallocene catalysts provided by the present disclosure can be effectively activated by a small amount of aluminum alkyls and boron-containing cocatalysts, effectively reducing the need to use Methylaluminoxane (MAO), thereby reducing the polymerization costs. In the catalysis of olefin homopolymerization and copolymerization, the steric hindrance of the catalyst can be effectively controlled by precisely adjusting the substituent of the metallocene catalyst, so that the key parameters such as the melting point, the molecular weight distribution and the like of a polymerization product are finely regulated and controlled, and the performance of the polymerization product is optimized, such as the thermal stability and the mechanical strength of the polymerization product are improved.

Detailed Description

For the purposes of promoting an understanding of the principles and advantages of the disclosure, reference will now be made in detail to the embodiments.

Hereinafter, the technical aspects of the present disclosure will be described in connection with specific embodiments. It should be understood that the description is only exemplary and is not intended to limit the scope of the present disclosure. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the concepts of the present disclosure.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The terms "comprises," "comprising," and/or the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly formal manner.

Where a convention analogous to "at least one of A, B and C, etc." is used, in general such a convention should be interpreted in accordance with the meaning of one of skill in the art having generally understood the convention (e.g., "a system having at least one of A, B and C" would include, but not be limited to, systems having a alone, B alone, C alone, a and B together, a and C together, B and C together, and/or A, B, C together, etc.).

In carrying out the present disclosure, it was found that related studies have suggested a cyclopentadienyl and phenoxy based geometry restriction catalyst that maintains high polymerization activity at 80 ℃ and is activated by small amounts of aluminum alkyls and borane based cocatalysts without the use of MAO. However, the activity of the catalyst of this system at higher temperatures of more than 100℃is significantly reduced, and there is room for further optimization of this type of catalyst. Therefore, the development and optimization of the novel catalyst are of great significance for improving POE production capacity, reducing cost and meeting market demands.

In view of this, the present disclosure provides a method for preparing a constrained geometry metallocene catalyst comprising a phenoxy group and uses thereof, and in particular, as a first aspect of the present disclosure, a metallocene catalyst having a structure as shown in formula (i) or formula (ii):

wherein, the metal center connected with the phenoxy structure in the metallocene catalyst is bridged with the metallocene ring or the indene ring;

Each X is independently selected from halogen;

r ₁、R₂ are each independently selected from phenyl or substituted phenyl;

R ₃、R₄、R₅ is independently selected from any one of hydrogen, hydrocarbon group of C ₁～C₁₂ and halogen;

R ₆、R₇、R₈、R₉、R₁₀、R₁₁ is each independently selected from any one of hydrogen, C ₁～C₁₂ hydrocarbyl, substituted silicon-based or C ₁～C₁₂ substituted hydrocarbyl.

According to the embodiment of the disclosure, the phenoxy structure is introduced to connect with the metal center, and a bridging structure is formed between the metal center and the metallocene ring or the indene ring, so that the structural stability of the catalyst is improved, and the electronic environment is modulated, so that the electronic density and the reactivity of the metal center are influenced. The metallocene catalyst has excellent thermal stability and chemical stability, and provides a solid foundation for polymerization under high temperature and severe conditions.

Preferably, X is independently taken from chlorine, bromine; r ₁、R₂ is independently selected from phenyl or substituted phenyl; r ₃、R₄、R₅ is independently selected from hydrogen and methyl; r ₆、R₇、R₈、R₉、R₁₀、R₁₁ is independently selected from hydrogen, C ₁～C₄ hydrocarbyl.

According to embodiments of the present disclosure, R ₁、R₂ are each independently selected from phenyl or substituted phenyl, which can adjust the electronic properties and steric environment of the catalyst, further increase the steric hindrance of the metallocene catalyst, form a geometrically constrained configuration, and can limit the approach of reactants and catalyst centers to exert control over intermediates and transition states during the catalytic reaction, thereby affecting the reaction pathways and product distribution. For example, in the polymerization of olefins, such steric hindrance may reduce the occurrence of chain transfer reaction, thereby increasing the molecular weight of the polymer.

According to embodiments of the present disclosure, substituents in substituted phenyl groups include any one or more of hydroxy, amino, methyl, methoxy;

The substituent in the substituted silicon group comprises any one or more of alkyl, aryl and methoxy;

the substituent of the substituted hydrocarbon group of C ₁～C₁₂ includes any one or more of hydroxyl group, amino group, acyl group and ether group.

According to the embodiment of the disclosure, each substituent group can be selected according to the performance requirement of the target catalyst, and the electronic and stereochemical properties of the catalyst can be adjusted, so that the activity and selectivity of the catalyst are affected.

As a second aspect of the present disclosure, there is provided a method for preparing a metallocene catalyst, comprising:

From compounds A under inert gas atmosphere Reacting with a compound M1- ⁿ Bu and TiX ₄ to obtain a metallocene catalyst with a structure shown in a formula (I);

Or C compound Reacting with a compound M ₁-ⁿ Bu and TiX ₄ to obtain a metallocene catalyst with a structure shown in a formula (II), wherein ,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁ has the same definition as the above, and M ₁ is independently selected from any one of lithium, sodium, potassium, rubidium and cesium; ⁿ Bu represents n-butyl.

According to embodiments of the present disclosure, the molar ratio between the a compound or the C compound and the B compound is 1:1, the molar ratio between the a compound or the C compound and the TiX ₄ is 1:1.5, the above reaction is performed in an organic solvent containing triethylamine, and after the X halogen atom in TiX ₄ is partially substituted in the above reaction, the Ti atom is connected to the phenoxy group in the a compound or the C compound and forms a bridged structure with the metallocene ring or the indene ring.

According to embodiments of the present disclosure, compound aFrom D compoundsWith E Compounds/>And (3) reacting to obtain the product.

According to an embodiment of the present disclosure, the molar ratio between the D compound and the E compound in the above reaction is 1:1, the D compound is an organic compound containing a silicon atom, wherein the silicon atom is connected to an organic group (R ₄ and R ₅) and an aromatic ring containing methoxy, and the alkali metal in the E compound may increase the nucleophilicity of the aromatic ring or make it leave as a leaving group, so that the position participates in the reaction, and the D compound reacts with the E compound to form the a compound.

According to embodiments of the present disclosure, compound CFrom D compoundsWith F Compounds/>Obtaining the product through reaction; wherein M ₂ is independently selected from any one of lithium, sodium, potassium, rubidium and cesium.

According to the embodiment of the disclosure, the molar ratio of the compound D to the compound F in the reaction is 1:1, and the compound F has alkali metal, so that the nucleophilicity of the carbon-alkali metal bond position in the aromatic ring is increased, and the organosilicon in the compound D and the activated position in the compound F are conveniently coupled to obtain the compound C.

According to embodiments of the present disclosure, D compoundsFrom B compounds M ₁-ⁿ Bu with G compoundsAnd H Compounds/>Obtained by a reaction wherein X ₁ is independently selected from halogen.

According to embodiments of the present disclosure, the molar ratio of H compound to B compound is 1:1 and the molar ratio of H compound to G compound is 1:5. M ₁ in the compound B M ₁-ⁿ Bu is alkali metal, and is independently selected from any one of lithium, sodium, potassium, rubidium and cesium, and an alkaline environment is provided in the reaction to promote nucleophilic substitution reaction; the compound B reacts with the compound G and the compound H together, and active silicon-chlorine bonds on the compound G react with aromatic rings in the compound H through nucleophilic substitution reaction to generate a compound D.

According to embodiments of the present disclosure, H compoundsFrom J Compound/>Reacting with methyl iodide and potassium hydroxide to convert hydroxy into methoxy.

Specifically, according to embodiments of the present disclosure, methyl iodide is used as the methylating agent and potassium hydroxide is used as the deprotonating agent under alkaline conditions. Potassium hydroxide is first synthesized from J compoundThe hydroxyl in the (B) is abstracted into a proton (H+) to form a corresponding phenol anion, the alcohol anion has higher nucleophilicity, and then the anion and methyl iodide undergo nucleophilic substitution reaction to lead to the leaving of iodine atoms, and a new methoxy (-OCH 3) is formed, thus obtaining H compound/>

According to embodiments of the present disclosure, J compoundsFrom K Compound/>With L compoundsPerforming Friedel-crafts reaction in zinc chloride and concentrated hydrochloric acid solution to obtain the product, wherein X ₁ is independently selected from fluorine, chlorine, bromine and iodine; r ₁、R₂ is independently selected from phenyl or substituted phenyl; r ₃ is independently selected from hydrogen, hydrocarbon group of C ₁～C₁₂ and halogen atom. Preferably, X ₁ is independently taken from chlorine, bromine; r ₁、R₂ is independently selected from phenyl or substituted phenyl; r ₃ is independently selected from hydrogen and methyl.

According to the embodiment of the disclosure, the molar ratio of the K compound to the L compound is 1:1, and the concentrated hydrochloric acid provides an acidic environment to increase the activity of the reactant and can also serve as a solvent or a reaction medium. Zinc chloride as Lewis acid increases the stability of the reaction intermediate, thereby promoting K compoundWith L Compounds/>Friedel-crafts alkylation reaction is carried out, alkyl is introduced into aromatic ring, thus phenol containing more steric hindrance substituent is formed, namely J compound

According to the embodiment of the disclosure, the above reactions are all performed under argon or nitrogen atmosphere, so that the interference of oxygen in the reaction system is avoided, the reactants or products are protected from being affected by oxygen, and the reactants can be prevented from reacting with impurities or moisture in the air.

As a third aspect of the present disclosure there is provided the use of a metallocene catalyst comprising:

Providing an activated metallocene catalyst;

and catalyzing olefin to carry out homo-polymerization reaction or copolymerization reaction by using the activated metallocene catalyst.

According to the embodiment of the disclosure, after the metallocene catalyst is activated, the metallocene center of the catalyst can obtain enough activity, so that the polymerization reaction of olefin can be effectively catalyzed, and the molecular weight, molecular weight distribution, composition and molecular structure of the copolymer and the like of the polymer are controlled.

According to embodiments of the present disclosure, the polymerization pressure of the homo-polymerization or copolymerization reaction is 0.1 to 3MPa, which may be, for example, 0.5MPa, 0.8MPa, 1.2MPa, 2.1MPa, 2.8MPa, etc.; the polymerization temperature is 25 to 250℃and may be, for example, 30℃80℃160℃200℃240 ℃. But are not limited to, the recited values, and other non-recited values within the range of values are equally applicable.

According to embodiments of the present disclosure, obtaining an activated metallocene catalyst comprises: the metallocene catalyst with the structure shown in the formula (I) or the formula (II) is mixed with aluminum alkyl in a first organic solvent, and then boron cocatalyst is added for activation. Wherein the first organic solvent comprises one or more of toluene, dichloromethane, diethyl ether, tetrahydrofuran, n-hexane and n-heptane. Preferably, the first organic solvent comprises one or more of n-hexane, n-heptane, toluene, dichloromethane.

According to the embodiment of the disclosure, the metallocene catalyst can be effectively activated by using a small amount of aluminum alkyl, and the electron density of the center of the metallocene catalyst is increased, so that active sites are generated, the activated metallocene catalyst can catalyze the polymerization reaction of various olefins, and the overall cost of the polymerization reaction can be greatly reduced.

According to embodiments of the present disclosure, catalyzing an olefin for homo-polymerization or copolymerization using an activated metallocene catalyst includes:

under 160-200 ℃, utilizing the activated metallocene catalyst to carry out homo-polymerization reaction or copolymerization reaction on olefin in a second organic solvent;

the homopolymerization reaction comprises the homopolymerization reaction of catalyzing C2-C6 olefin;

The copolymerization reaction comprises the catalysis of the copolymerization reaction of C2-C6 olefins and C6-C10 olefins.

According to embodiments of the present disclosure, the polymerization reaction may be carried out at 160 ℃, 175 ℃, 186 ℃, 190 ℃, 195 ℃, etc., but is not limited to the recited values, and other non-recited values within the range of values are equally applicable. The metallocene catalyst provided by the disclosure has higher thermal stability, can play a role in a higher temperature range, and is beneficial to the full reaction of olefin at a higher temperature.

According to an embodiment of the present disclosure, the second organic solvent includes any one or more of tetrahydrofuran, n-pentane, n-hexane, n-heptane, petroleum ether, toluene, benzene, and dichloromethane; preferably, the second organic solvent is n-hexane, n-heptane, toluene or dichloromethane; more preferably toluene.

According to an embodiment of the present disclosure, the C2 to C6 olefins include: any one or more of ethylene, propylene, 1-butene, 1-pentene and 1-hexene; the C6-C10 olefins include one or more of 1-hexene, 1-octene, and 1-decene. Preferably, the olefin is ethylene or propylene.

According to embodiments of the present disclosure, the first organic solvent is used to dissolve the catalyst, the second organic solvent is used to perform the polymerization reaction, and the corresponding organic solvent may be selected according to the structure, compatibility, and stability at the reaction temperature of the actual catalyst or olefin. The polymerization of olefins in the presence of a catalyst may be carried out by solution polymerization, slurry polymerization, gas phase polymerization or other forms of polymerization processes, without limitation.

In order to make the objects, technical solutions and advantages of the present disclosure clearer, the technical solutions and principles of the present disclosure are further described below by specific embodiments. It should be noted that the following specific examples are given by way of illustration only and the scope of the present disclosure is not limited thereto.

All the synthetic and polymerization steps in the examples below were carried out under anhydrous conditions and under nitrogen protection. All solvents are dried to remove water and other test materials and reagents used, unless otherwise specified, are commercially available, and the examples, without any particular skill or condition being noted, are conventional and may be carried out according to the techniques or conditions described in the literature in this field or according to the product specifications. In the examples below, nuclear Magnetic Resonance (NMR) analysis was performed using a 400MHz nuclear magnetic instrument manufactured by Bruker; mass spectrometry was determined by Thermo FISHER SCIENTIFIC LTQ Orbitrap XL (electrospray positive ion mode, ESI+) or P-SIMS-Gly of Bruker Daltonics Inc (electron bombardment positive ion mode, EI+); the molecular weight and molecular weight distribution of the polymer were determined by Gel Permeation Chromatography (GPC) (polystyrene columns, HR2 and HR4, tank temperature 45 ℃, water 1515 and Water 2414 pumps; mobile phase tetrahydrofuran, flow rate 1.0 mL/min); the glass transition temperature and melting point of the polymer were determined by TA DSC Q20.

Example 1

Preparing a metallocene catalyst having a structure represented by formula (I ₁), comprising:

Step (1): preparation of 2-bromo-4-methyl-6-benzhydryl phenol

186G of 2-bromo-4-methylphenol and 184g of benzhydrol were weighed into a 350mL pressure-resistant bottle which was placed on a heating apparatus and heated to 100℃to completely melt the reaction mass. Subsequently, 68g of a concentrated hydrochloric acid solution of zinc chloride was slowly added, a pressure-resistant bottle cap was closed, and the temperature was raised to 160℃to react for 6 hours to complete the reaction. After the reaction is finished, adding proper amount of ethyl acetate and water into the system for extraction and separation, drying the separated organic phase, removing 80% of solvent under the condition of reduced pressure, adding methanol into the residue for recrystallization, and filtering to obtain a white solid product: 2-bromo-4-methyl-6-benzhydryl phenol was produced in 320g yield, 90.9% relative to the theoretical yield.

The nuclear magnetic hydrogen spectrum of the 2-bromo-4-methyl-6-benzhydryl phenol is ：¹H NMR(400MHz,Chloroform-d)δ7.29(dd,J＝8.1,6.4Hz,4H),7.25–7.20(m,2H),7.11(dd,J＝7.1,1.8Hz,4H),6.58(d,J＝2.0Hz,1H),5.86(s,1H),5.42(s,1H),2.17(s,3H); as a measured value of molecular weight: m/z 352.0455[ M ] +; theoretical value: m352.0463; theoretical value of elemental analysis: c,68.00; h,4.85; o,4.53; actual measurement value: c,67.75; h,4.98; o,4.44.

Step (2): preparation of 5-methyl-2-methoxy-3-benzhydryl bromobenzene

35.2G of 2-bromo-4-methyl-6-benzhydryl phenol was weighed and placed in a eggplant-shaped bottle, 100mL of acetonitrile was added to dissolve the same, 8g of potassium hydroxide was added to the eggplant-shaped bottle, 30g of methyl iodide was slowly added at room temperature under stirring, and the reaction was continued for 12 hours. After the completion of the reaction, the solvent was removed by distillation under reduced pressure, followed by washing the solid after the reaction with n-hexane three times, collecting the filtrate, and removing the n-hexane solvent under reduced pressure to finally obtain a pale yellow solid product: the yield of 5-methyl-2-methoxy-3-benzhydryl bromobenzene was 29.5g, 80.60% relative to the theoretical yield.

The nuclear magnetic hydrogen spectrum of the 5-methyl-2-methoxy-3-benzhydryl bromobenzene is ：¹H NMR(400MHz,Chloroform-d)δ7.28(tt,J＝6.6,1.0Hz,4H),7.24–7.18(m,2H),7.16–7.04(m,4H),6.67(d,J＝2.2Hz,1H),5.95(s,1H),3.49(s,3H),2.20(m,3H). molecular weight actual measurement values: m/z 366.0605[ M+ ]. Theoretical value: m366.0619. Theoretical value of elemental analysis: c,68.67; h,5.21; o,4.36. Actual measurement value: c,68.25; h,5.58; o,4.50.

Step (3): preparation of 4-methyl-2-benzhydryl-6-dimethylchlorosilane anisole

36.6G (100 mmol) of 2-methoxy-5-methyl-3-benzhydryl bromobenzene are dissolved in a mixed solvent consisting of 50mL of tetrahydrofuran and 100mL of n-hexane under nitrogen atmosphere. At-78℃a solution of 100mmol of n-butyllithium in n-hexane was slowly added. Subsequently, the temperature was slowly raised to-30℃and maintained at this temperature for 1 hour, and then the temperature was again lowered to-60℃to obtain a suspension, designated as suspension A. At the same time, 64.5g (50 mmol) of dimethyldichlorosilane was dissolved in 200mL of n-hexane and the solution was cooled to-60℃and labeled solution B.

Suspension a was slowly injected into solution B via syringe under anhydrous and anaerobic conditions and after 1 hour of reaction at-60 ℃, the temperature was allowed to return to room temperature and the reaction was continued for 12 hours under these conditions. After the completion of the reaction, the solvent was removed by vacuum evaporation, and then n-hexane was added for dissolution, followed by filtration using celite. The filtrate was evaporated in vacuo to give the product as a pale yellow liquid: the yield of 4-methyl-2-benzhydryl-6-dimethylchlorosilane anisole was 31.5g and 82.9% relative to the theoretical yield.

Through testing, the nuclear magnetic hydrogen spectrum ：¹H NMR(400MHz,Chloroform-d)δ7.02–6.99(m,5H),6.96–6.92(m,5H),6.89–6.85(m,2H),5.89(s,1H),3.25(s,3H),1.79(s,3H),0.50(s,6H). molecular weight of the 4-methyl-2-benzhydryl-6-dimethyl chlorsily anisole is measured: m/z 380.1333[ M+ ]. Theoretical value: m380.1363. Theoretical value of elemental analysis: c,72.51; h,6.61; o,4.20. Actual measurement value: c,72.00; h,6.66; o,4.07.

Step (4): preparation of the Compound (5-methyl-2-phenoxy-3-benzhydryl cyclopentadienyl dimethylsilyl phenyl titanium dichloride) of formula (I ₁)

3.80G (10 mmol) of 4-methyl-2-benzhydryl-6-dimethylchlorosilane anisole are dissolved in 20mL of tetrahydrofuran under nitrogen atmosphere and marked as solution C. In addition, 0.80g (11 mmol) of cyclopentadienyl lithium was dissolved in 20mL of tetrahydrofuran and labeled as solution D. Solution D was slowly added to solution C at-30 ℃ and the temperature of the mixture was then raised to room temperature and held for 12 hours to complete the reaction. After the reaction, water was added to the reaction mixture to extract, and the organic phase was dried. Subsequently, the product was purified by column chromatography (using pure petroleum ether as eluent) to give a pale yellow liquid: 4-methyl-2-benzhydryl-6-cyclopentadienyl dimethylsilyl anisole in a yield of 2.10g and a yield of 53.2%.

1.98G (5 mmol) of 4-methyl-2-benzhydryl-6-cyclopentadienyl dimethylsilyl anisole was dissolved in 20mL of toluene and 2.15mL of triethylamine was added thereto. 5mmol of n-butyllithium was added at-70℃and the temperature of the mixture was then raised to room temperature and kept for 12 hours. After the reaction was completed, the mixture was cooled to 0℃and 6mL of a toluene solution containing 6mmol of titanium tetrachloride at a concentration of 1mol/L was slowly added. Then, the temperature was slowly raised to room temperature and kept for reaction for 1 hour, followed by heating to 95℃and further reaction for 10 hours. After the reaction was completed, the reaction mixture was cooled to room temperature, and the solvent was removed by vacuum-pumping. Toluene was then added to dissolve the residue, and the residue was filtered using celite, and the filtrate was vacuum-dried and recrystallized using a toluene/n-hexane mixed solvent to give a brown solid product: 5-methyl-2-phenoxy-3-benzhydryl cyclopentadienyl dimethylsilyl phenyl titanium dichloride in a yield of 0.69g and a yield of 27%.

The nuclear magnetic hydrogen spectrum of the 5-methyl-2-phenoxy-3-benzhydryl cyclopentadienyl dimethylsilyl phenyl titanium dichloride is ：¹H NMR(400MHz,Chloroform-d)δ7.23–7.18(m,4H),7.12(m,4H),6.90(d,1H),6.80(d,5H),3.53(d,3H),2.12(s,3H),0.35(d,6H). element analysis theory: c,63.17; h,5.11; o,3.12. Actual measurement value: c,62.80; h,5.26; o,3.15.

Example 2

The same preparation as in example 1 was conducted except that the step (4) was replaced with the preparation of a metallocene catalyst (5-methyl-2-phenoxy-3-benzhydryl-dimethylsilyl phenyl titanium dichloride) having the structure shown in the formula (I ₂)

3.80G (10 mmol) of 4-methyl-2-benzhydryl-6-dimethylchlorosilane anisole are dissolved in 20mL of tetrahydrofuran under nitrogen atmosphere and labeled as solution E. In addition, 1.40g (11 mmol) of lithium tetramethylcyclopentadiene was dissolved in 20mL of tetrahydrofuran and labeled as solution F. Solution F was slowly added to solution E at-30 ℃, followed by raising the temperature of the mixture to room temperature and reacting under this condition for 12 hours. After the completion of the reaction, water was added to the mixture for extraction, followed by drying the organic phase. Purification by column chromatography (using pure petroleum ether as eluent) gives a pale yellow liquid: 4-methyl-2-benzhydryl-6-tetramethyl cyclopentadienyl dimethylsilyl anisole with a yield of 2.45g and 54.3%.

Further, 2.26g (5 mmol) of 4-methyl-2-benzhydryl-6-tetramethylcyclopentadienyl dimethylsilanylmethyl ether was dissolved in 20mL of toluene, and 2.15mL of triethylamine was added thereto. 5mmol of n-butyllithium were added at-70℃after which the temperature of the mixture was raised to room temperature and kept for 12 hours. After the reaction was completed, the mixture was cooled to 0℃and 6mL of a toluene solution containing 6mmol of titanium tetrachloride at a concentration of 1mol/L was slowly added. Subsequently, the temperature was slowly raised to room temperature and kept for reaction for 1 hour, followed by heating to 95℃and further reaction for 10 hours. Finally, the reaction mixture was cooled to room temperature and the solvent was removed by vacuum-pumping. Toluene was added to dissolve the residue, and the residue was filtered using celite, and after the filtrate was dried under vacuum, the filtrate was recrystallized using toluene/n-hexane mixed solvent to give a brown solid product: 5-methyl-2-phenoxy-3-benzhydryl tetramethyl cyclopentadienyl dimethylsilyl phenyl titanium dichloride in a yield of 0.48g and 17%.

The nuclear magnetic hydrogen spectrum of the 5-methyl-2-phenoxy-3-benzhydryl tetramethyl cyclopentadienyl dimethylsilyl phenyl titanium dichloride is ：¹H NMR(400MHz,Chloroform-d)δ7.25–7.16(m,4H),7.11(m,4H),6.90(d,1H),6.75(d,1H),3.35(s,3H),2.21(s,3H),1.88(s,6H),1.23(d,6H),0.39(d,6H). element analysis theoretical value: c,65.38; h,6.02; o,2.81. Actual measurement value: c,65.57; h,6.23; o,2.99.

Example 3

The same preparation as in example 1 was carried out, except that the step (4) was replaced with the preparation of a metallocene catalyst (5-methyl-2-phenoxy-3-benzhydryl dimethylsilyl phenyl titanium dichloride) having the structure shown in the formula (II ₁)

3.80G (10 mmol) of 4-methyl-2-benzhydryl-6-dimethylchlorosilane anisole was added to 20mL of tetrahydrofuran under the protection of nitrogen atmosphere, the resulting solution was labeled as solution G, and 1.32G (11 mmol) of indenyl lithium was dissolved in 20mL of tetrahydrofuran, and the resulting solution was labeled as solution H. Solution H was slowly added to solution G at-30 ℃ and the mixture was subsequently warmed to room temperature and allowed to react for 12 hours. After the completion of the reaction, water was added to the mixture for extraction, followed by drying the organic phase. Purification by column chromatography (using pure petroleum ether as eluent) gives the product as a pale yellow liquid: 4-methyl-2-benzhydryl-6-indenyl dimethylsilyl anisole yield was 3.32g and 74.4%.

Further, 2.23g (5 mmol) of 4-methyl-2-benzhydryl-6-indenyl dimethylsilyl anisole was dissolved in 20mL of toluene and 2.15mL of triethylamine was added. To this solution was added 5mmol of n-butyllithium at-70℃and then the temperature was returned to room temperature and maintained for 12 hours to continue the reaction. After the reaction was completed, the mixture was cooled to 0℃and 6mL of a toluene solution containing 6mmol of titanium tetrachloride at a concentration of 1mol/L was slowly added, and the temperature was slowly raised to room temperature to react for 1 hour, and further heated to 95℃and the reaction was continued for 10 hours. Finally, the reaction mixture was cooled to room temperature and the solvent was removed by vacuum-pumping. Toluene was again added to dissolve the residue, and filtration was performed with celite. Recrystallizing the filtrate subjected to vacuum pumping treatment by using a toluene/n-hexane mixed solvent to obtain a red solid product: 5-methyl-2-phenoxy-3-benzhydryl indenyl dimethylsilyl phenyl titanium dichloride produced in 0.78g and yield of 27.7%.

The nuclear magnetic hydrogen spectrum of the 5-methyl-2-phenoxy-3-benzhydryl indenyl dimethyl silicon phenyl titanium dichloride is ：¹H NMR(400MHz,Chloroform-d)δ7.35(d,1H),7.26–7.16(m,5H),7.09(d,5H),6.95(d,2H),6.90(d,1H),6.80(dd,2H),6.47(dt,1H),5.92(s,1H),3.43(d,3H),2.08(s,3H),0.36(s,6H). element analysis theory: c,65.97; h,5.18; o,2.83. Actual measurement value: c,66.26; h,5.45; o,2.57.

Example 4

The same preparation as in example 1 was conducted except that step (4) was replaced with the preparation of a metallocene catalyst (5-methyl-2-phenoxy-3-benzhydryl- (1-trimethylsilylindenyl) dimethylsilyl phenyl titanium dichloride) having the structure shown in formula (II ₂)

3.80G (10 mmol) of 4-methyl-2-benzhydryl-6-dimethylchlorosilane anisole were dissolved in 20mL of tetrahydrofuran under nitrogen atmosphere and the resulting solution was labeled as solution J. Subsequently, 2.13g (11 mmol) of 1-trimethylsilyl indenyl lithium was dissolved in another 20mL of tetrahydrofuran and the resulting solution was labeled as solution K. Solution K was slowly added to solution J at-30℃after which the mixture was gradually warmed to room temperature and reacted for 12 hours. After completion of the reaction, water was added to the mixture for extraction, and then the organic phase was dried. The product was purified by column chromatography using pure petroleum ether as eluent to give the product as a pale yellow liquid: 4-methyl-2-benzhydryl-6- (1-trimethylsilylindenyl) dimethyl silyl anisole was produced in a yield of 4.06g and a yield of 78.37%.

Further, 2.59g (5 mmol) of 4-methyl-2-benzhydryl-6- (1-trimethylsilylindenyl) dimethylsilyl anisole was dissolved in 20mL of toluene, and 2.15mL of triethylamine was added thereto. 5mmol of n-butyllithium was added at-70℃and the temperature was then returned to room temperature for reaction for 12 hours. After the reaction was completed, the mixture was cooled to 0℃and 6mL of a toluene solution containing 6mmol of titanium tetrachloride at a concentration of 1mol/L was slowly added. After that, the temperature was gradually raised to room temperature for further 1 hour, followed by heating to 95℃for further 10 hours. Finally, the mixture was cooled to room temperature, the solvent was removed by vacuum extraction, toluene was added to dissolve the residue, and filtration was performed with celite. After the filtrate is subjected to vacuum pumping treatment, the filtrate is recrystallized by using a toluene/normal hexane mixed solvent to obtain a black and red solid product: 5-methyl-2-phenoxy-3-benzhydryl- (1-trimethylsilylindenyl) dimethylsilyl phenyl titanium dichloride was produced in a yield of 1.28g and a yield of 40.3%.

The nuclear magnetic hydrogen spectrum of the 5-methyl-2-phenoxy-3-benzhydryl- (1-trimethylsilyl indenyl) dimethylsilyl phenyl titanium dichloride is ：1H NMR(400MHz,Chloroform-d)δ7.37(d,1H),7.25–7.19(m,4H),7.05(m,4H),6.95–6.89(d,3H),6.75(m,2H),6.47(s,1H),6.32(s,1H),3.25(s,3H),2.11(s,3H),0.41(s,6H),0.19(s,9H). element analysis theory: c,64.15; h,5.86; o,2.51. Actual measurement value: c,63.85; h,5.75; o,2.77.

Example 5

The same preparation as in example 1 was conducted, except that the step (4) was replaced with the preparation of a metallocene catalyst (5-methyl-2-phenoxy-3-benzhydryl- (1-methylindenyl) dimethylsilyl phenyl titanium dichloride) having the structure shown in the formula (II ₃)

3.80G (10 mmol) of 4-methyl-2-benzhydryl-6-dimethylchlorosilane anisole were dissolved in 20mL of tetrahydrofuran under nitrogen atmosphere, and the resulting solution was labeled as solution L. Then, 1.32g (11 mmol) of 1-methylindenyl lithium was dissolved in another 20mL of tetrahydrofuran, and the resulting solution was labeled as solution M. Solution M was slowly added to solution L at-30℃and after gradually raising the temperature of the mixture to room temperature, it was reacted for 12 hours. After completion of the reaction, water was added to the mixture for extraction, and then the organic phase was dried. The product was purified by column chromatography using pure petroleum ether as eluent to give the product as a pale yellow liquid: 4-methyl-2-benzhydryl-6- (1-methylindenyl) dimethylsilyl anisole in a total weight of 3.35g and a yield of 72.83%.

2.30G (5 mmol) of 4-methyl-2-benzhydryl-6- (1-methylindenyl) dimethylsilyl anisole was dissolved in 20mL of toluene, and 2.15mL of triethylamine was added thereto. 5mmol of n-butyllithium was added at-70℃and the temperature was then returned to room temperature and reacted for 12 hours. After the reaction was completed, the mixture was cooled to 0℃and 6mL of a toluene solution containing 6mmol of titanium tetrachloride at a concentration of 1mol/L was slowly added. Subsequently, the temperature was slowly raised to room temperature and reacted for 1 hour, and the reaction was continued for 10 hours by heating to 95 ℃. Finally, the mixture was cooled to room temperature, the solvent was removed by vacuum extraction, toluene was added to dissolve the residue, and filtration was performed using celite. After the filtrate is subjected to vacuum pumping treatment, adopting toluene/n-hexane mixed solvent for recrystallization to obtain a red solid product: 5-methyl-2-phenoxy-3-benzhydryl- (1-methylindenyl) dimethylsilyl phenyl titanium dichloride in a yield of 0.85g and 29.5%.

The nuclear magnetic hydrogen spectrum of the 5-methyl-2-phenoxy-3-benzhydryl- (1-methylindenyl) dimethylsilyl phenyl titanium dichloride is ：¹H NMR(400MHz,Chloroform-d)δ7.31-7.40(m,7H),7.11-7.20(m,7H),6.98(s,1H),6.91(s,1H),6.25(s,2H),5.50(s,1H),3.21(m,1H),2.39(s,3H),1.80(s,3H),0.25(s,6H). element analysis theoretical values: c,66.45; h,5.40; o,2.77. Actual measurement value: c,66.85; h,5.52; o,2.96.

Example 6

The same preparation as in example 1 was conducted, except that the step (4) was replaced with the preparation of a metallocene catalyst (5-methyl-2-phenoxy-3-benzhydryl- (hexamethylindenyl) dimethylsilyl phenyl titanium dichloride) having the structure shown in the formula (II ₄)

3.80G (10 mmol) of 4-methyl-2-benzhydryl-6-dimethylchlorosilane anisole are dissolved in 20mL of tetrahydrofuran under nitrogen atmosphere, this solution being marked as solution N. Subsequently, 2.20g (11 mmol) of hexamethylindenyl lithium were dissolved in another 20mL of tetrahydrofuran, and this solution was labeled as solution O. Solution O was slowly added to solution N at-30 ℃ and the mixture was gradually warmed to room temperature and reacted for 12 hours. After completion of the reaction, water was added to the mixture to extract, and the organic phase was dried. The product was purified by column chromatography using pure petroleum ether as eluent to give the product as a pale yellow liquid: 4-methyl-2-benzhydryl-6-hexamethylindenyl dimethylsilyl anisole, yield was 4.26g and 80.38%.

Further, 2.65g (5 mmol) of 4-methyl-2-benzhydryl-6-hexamethylindenyl dimethylsilyl anisole was dissolved in 20mL of toluene, and 2.15mL of triethylamine was added thereto. 5mmol of n-butyllithium was added at-70℃and the temperature was then returned to room temperature for reaction for 12 hours. After the reaction was completed, the mixture was cooled to 0℃and 6mL of a toluene solution containing 6mmol of titanium tetrachloride at a concentration of 1mol/L was slowly added, the temperature was gradually raised to room temperature to react for 1 hour, followed by heating to 95℃to continue the reaction for 10 hours. Finally, the mixture was cooled to room temperature and the solvent was removed by vacuum drying. Toluene was added to dissolve the residue and filtered through celite. After the filtrate is subjected to vacuum pumping treatment, the filtrate is recrystallized by using a toluene/n-hexane mixed solvent to obtain a red solid product: 5-methyl-2-phenoxy-3-benzhydryl-6- (hexamethylindenyl) dimethylsilyl phenyl titanium dichloride gave 1.37g and 42.35% yield.

The nuclear magnetic hydrogen spectrum of the 5-methyl-2-phenoxy-3-benzhydryl-6- (hexamethylindenyl) dimethylsilyl phenyl titanium dichloride is ：¹H NMR(400MHz,Chloroform-d)δ7.28-7.35(m,3H),7.12-7.18(m,7H),7.00(s,1H),6.95(s,1H),5.45(s,1H),3.05(m,1H),2.63(s,3H),2.49(s,3H),2.27(s,3H),2.11(s,3H),2.05(s,3H),1.98(s,3H),1.68(s,3H),0.22(s,6H). element analysis theory: c,68.52; h,6.37; o,2.47. Actual measurement value: c,68.27; h,6.15; o,2.36.

Example 7

The metallocene catalysts prepared in examples 1 to 6 are used for catalyzing ethylene to carry out homopolymerization, and the specific polymerization method is as follows:

Under the protection of nitrogen atmosphere, 20mL of n-heptane was added as a polymerization solvent to a 350mL polymerization reactor. The reactor was then connected to a polymerization apparatus and the apparatus was evacuated using an Edwardsier vacuum pump for at least 5 minutes to remove oxygen from the polymerization apparatus piping. The temperature control system was adjusted and the reaction temperature was set at 180 ℃.

The metallocene catalysts (containing 5. Mu. Mol of titanium) prepared in examples 1 to 6 were used with triisobutylaluminum (100. Mu. Mol) and mixed with a boron-containing cocatalyst for activation. Under the atmosphere of ethylene, the activated metallocene catalyst is injected into the reaction device through an injector, the injection valve is closed immediately after the injection is completed, ethylene with preset pressure is introduced into the reaction kettle, the ethylene pressure range in the embodiment is set between 8 atm and 30atm, and the reaction time is 10 minutes. After the reaction is finished, the ethylene main valve is closed, and then the exhaust valve is slowly opened for discharging. The reactor was removed from the apparatus and ethanol was added thereto to precipitate the polymer, and the resulting polyethylene was collected by suction filtration and vacuum drying.

The polymerization results are detailed in table 1.

TABLE 1

Wherein the total volume of the polymerization reaction is 20mL, and the polymerization temperature is 180 ℃; the unit of polymerization activity is 10 ⁵g_PE·mol^-1·h^-1; the melting point of the polyethylene is measured by a Differential Scanning Calorimeter (DSC); the number average molecular weight unit was 10 ⁴g mol^-1, and was measured by GPC.

As can be seen from Table 1, after the metallocene catalyst provided by the present disclosure is activated, the polymerization reaction of ethylene can be catalyzed at a higher temperature of 180 ℃, the polymerization activity can reach 39.72×10 ⁵g_PE·mol^-1·h^-1, the melting point can reach 128.26 ℃, the number average molecular weight is 2.26×10 ⁴～9.11×10⁴g mol^-1, and the molecular weight distribution is 1.8-2.8.

Example 8

The metallocene catalysts prepared in examples 1 to 6 are used for catalyzing ethylene and 1-octene to carry out copolymerization, and the specific polymerization method is as follows:

To a 350mL polymerization reactor was added 20.6mL of n-heptane and 9.4mL of 1-octene under nitrogen atmosphere. The reactor was then connected to a polymerization apparatus and the apparatus was evacuated using an Edwardsier vacuum pump for at least 5 minutes to remove oxygen from the polymerization apparatus piping. The temperature control system was adjusted and the reaction temperature was set at 180 ℃.

The metallocene catalysts (containing 5. Mu. Mol of titanium) prepared in examples 1 to 6 were used with triisobutylaluminum (100. Mu. Mol) and mixed with a boron-containing cocatalyst for activation. The activated metallocene catalyst was injected into the reaction apparatus through an injector under an ethylene atmosphere of 2atm, the injection valve was closed immediately after the injection was completed, and ethylene of a predetermined pressure was introduced into the reaction vessel, the ethylene pressure in this example being 30atm, and the reaction time being 10 minutes. After the reaction is finished, the ethylene main valve is closed, and then the exhaust valve is slowly opened for discharging. The reaction vessel was removed from the apparatus, and ethanol was added thereto to precipitate a polymer, and the resulting polymer was collected by suction filtration and vacuum drying.

The results of the polymerization are detailed in table 2.

TABLE 2

Wherein the total volume of the polymerization reaction is 30mL, and the concentration of octene is 2M; the unit of polymerization activity is 10 ⁵g_PE·mol^-1·h^-1; the melting point of the polymer is measured by a Differential Scanning Calorimeter (DSC); the number average molecular weight unit was 10 ⁴g mol^-1, and was measured by GPC.

As can be seen from Table 2, the metallocene catalyst provided by the present disclosure can catalyze the copolymerization of ethylene and 1-octene at a higher temperature (180 ℃) after activation, the polymerization activity can reach 28.44×10 ⁵g_PE·mol^-1·h^-1 at the highest, the melting point is 61.80 ℃ to 89.65 ℃, the 1-octene insertion ratio is 7.1% -11.1%, the number average molecular weight is 1.88×10 ⁴～7.80×10⁴, and the molecular weight distribution is 1.9-2.2.

Based on the technical scheme, the geometry restriction metallocene catalyst containing phenoxy has the advantages that by introducing a phenoxy structure with larger steric hindrance and forming a bridging structure with a metallocene ring or an indene ring, the steric hindrance of a metal center can be effectively increased, and the geometry restriction is formed by further increasing the steric hindrance of the metallocene catalyst due to the substituent which is a benzene ring or a substituted benzene ring. So that the catalyst has stronger thermal stability and can catalyze the homo-polymerization reaction and the copolymerization reaction of olefin at the temperature of 180 ℃. And through fine adjustment of the metallocene ring structure and substituent groups, the catalyst activity can be precisely controlled, and the product performance can be optimized, so that the catalyst is suitable for the specific requirements of polymerization reaction at high temperature. The poly-low-carbon olefin and the copolymer thereof with specific melting point, molecular weight distribution, glass transition temperature and other adjustable properties are produced.

The foregoing embodiments have been provided for the purpose of illustrating the general principles of the present disclosure, and are not meant to limit the disclosure to the particular embodiments disclosed, but to limit the scope of the disclosure to the particular embodiments disclosed.

Claims (10)

1. A metallocene catalyst having a structure represented by formula (i) or formula (ii):

Wherein, the metal center connected with the phenoxy structure in the metallocene catalyst is bridged with the metallocene ring or the indene ring;

Each X is independently selected from halogen;

r ₁、R₂ are each independently selected from phenyl or substituted phenyl;

R ₃、R₄、R₅ is independently selected from any one of hydrogen, hydrocarbon group of C ₁～C₁₂ and halogen;

R ₆、R₇、R₈、R₉、R₁₀、R₁₁ is each independently selected from any one of hydrogen, C ₁～C₁₂ hydrocarbyl, substituted silicon-based or C ₁～C₁₂ substituted hydrocarbyl.

2. The metallocene catalyst according to claim 1, wherein,

The substituent in the substituted phenyl comprises any one or more of hydroxyl, amino, methyl and methoxy;

The substituent in the substituted silicon group comprises any one or more of alkyl, aryl and methoxy;

the substituent of the substituted hydrocarbyl of C ₁～C₁₂ comprises any one or more of hydroxyl, amino, acyl and ether groups.

3. A process for the preparation of a metallocene catalyst as claimed in claim 1 or 2, comprising:

From compounds A under inert gas atmosphere Reacting with a compound M ₁-ⁿ Bu and TiX ₄ to obtain the metallocene catalyst with the structure shown in the formula (I);

Or C compound Reacting with the compound B and TiX ₄ to obtain the metallocene catalyst with the structure shown in the formula (II);

Wherein, after the X halogen atom in TiX ₄ is partially substituted in the reaction, the Ti atom is connected with the phenoxy in the A compound or the C compound and is bridged with a metallocene ring or an indene ring;

R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁ And X is as defined in claim 1;

m ₁ is independently selected from any one of lithium, sodium, potassium, rubidium and cesium;

ⁿ Bu represents n-butyl.

4. The method for producing a metallocene catalyst according to claim 3, wherein,

The A compoundFrom D Compounds/>With E compoundsObtaining the product through reaction;

The C compound From D Compounds/>With F compoundsObtaining the product through reaction;

Wherein ,R₁、R₂、R₃、R₄、R₅、R₆、R₇、R₈、R₉、R₁₀、R₁₁ and X are as defined in claim 1;

m ₂ is independently selected from any one of lithium, sodium, potassium, rubidium and cesium.

5. The method for preparing a metallocene catalyst according to claim 4, wherein,

The D compoundFrom the B compound M ₁-ⁿ Bu with the G compound/>And H Compounds/>Obtaining the product through reaction;

wherein R ₁、R₂、R₃、R₄、R₅、M₁、ⁿ Bu is as defined in claim 3;

x ₁ is independently selected from halogen.

6. The method for producing a metallocene catalyst according to claim 5, wherein,

The H compoundFrom J Compound/>Reacting with methyl iodide and potassium hydroxide, and converting hydroxyl into methoxy to obtain;

The J compound From K Compound/>With L Compounds/>Performing Friedel-crafts reaction in zinc chloride and concentrated hydrochloric acid solution to obtain the product;

wherein R ₁、R₂、R₃、X₁ is as defined in claim 5.

7. Use of the metallocene catalyst of claim 1, comprising:

Providing an activated metallocene catalyst;

And catalyzing olefin to carry out homo-polymerization reaction or copolymerization reaction by using the activated metallocene catalyst.

8. The use of claim 7, wherein obtaining the activated metallocene catalyst comprises:

And after the metallocene catalyst and the aluminum alkyl are mixed in a first organic solvent, adding a boron cocatalyst for activation.

9. The use of claim 8, wherein catalyzing the homo-or copolymerization of olefins with the activated metallocene catalyst comprises:

carrying out the homopolymerization or copolymerization of olefin in a second organic solvent by utilizing the activated metallocene catalyst at 160-200 ℃;

the homopolymerization reaction comprises the homopolymerization reaction of catalyzing C2-C6 olefin;

the copolymerization reaction comprises catalyzing the copolymerization reaction of the C2-C6 olefin and the C6-C10 olefin.

10. The use according to claim 9, wherein,

The first organic solvent comprises one or more of toluene, dichloromethane, diethyl ether, tetrahydrofuran, n-hexane and n-heptane;

the second organic solvent comprises any one or more of tetrahydrofuran, n-pentane, n-hexane, n-heptane, petroleum ether, toluene, benzene and methylene dichloride;

the C2-C6 olefins include: any one or more of ethylene, propylene, 1-butene, 1-pentene and 1-hexene;

the C6-C10 olefin comprises one or more of 1-hexene, 1-octene and 1-decene.