Tetraaryl ethoxy side chain monometalated compounds, catalyst systems comprising the same and processes for polyolefin synthesis conducted using the same

Abstract

The application discloses a kind of four aryl ethoxy side chain single metallocene compound, catalyst system comprising it and the polyolefin synthesis method carried out by application carries out.The structural formula of the four aryl ethoxy side chain single metallocene compound is as follows: wherein, M is selected from Ti, Zr or Hf;Cp' is selected from cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl and substituted fluorenyl;Ar is selected from phenyl and substituted phenyl;X is selected from halogen, alkyl, alkoxy and dialkylamino, phenyl and benzyl.Using the catalyst system comprising the four aryl ethoxy side chain single metallocene compound catalyzes olefin polymerization reaction, because the active center of four aryl ethoxy side chain single metallocene is single, α-olefin isomerization side reaction is highly inhibited, can significantly improve the α-olefin content of polyisobutylene product, reduce product molecular weight distribution.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of olefin catalytic polymerization, in particular to a tetraaryl ethoxy side chain monometallic compound, a catalyst system comprising the same and a polyolefin synthesis method using the same. BACKGROUND

[0002] The production of high activity polyisobutylene (HRPIB) is carried out with isobutylene or mixed carbon four as raw material, BF3 cationic catalyst at about -30℃. However, due to the existence of serious isomerization side reaction in the reaction system, the content of chain end α-double bond is only about 90%, which is difficult to further improve. At the same time, due to the need of low temperature conditions at about -30℃ for the reaction, the production cost is high. In addition, there are problems of equipment corrosion, fluorine-containing wastewater discharge pollution, etc.

[0003] Barsan et al. first synthesized medium and high molecular weight polyisobutylene using (η 5 -C5Me5)TiMe3 / B(C6F5)3 metallocene catalyst system. In the temperature range of -20 to -78℃, the Mw molecular weight of polyisobutylene product increased from 3×10 4 (Mw / Mn=0~3) to 2×10 5 (Mw / Mn=0~2) (Barsan F., Baird M C. The first example of polymerization of isobutylene induced by a metallocene like initiator [(η5-C5Me5)TiMe2(μ-Me)B(C6F5)3] [J]. Chemical Communications, 1995, 1065-1066.).

[0004] Andrew G. Carr et al. used Cp 2 ZrMe 2 and Cp*2ZrMe2 / B(C6F5)3 catalyst system to catalyze isobutylene homopolymerization and isobutylene / isoprene copolymerization, and obtained medium and high molecular weight polyisobutylene (Carr A G, Dawsor DM. Zirconocenes as initiators for carbocationic isobutene home and copolymerizations [J]. Macromolecules, 1998, 31(7): 2035-2040.).

[0005] Wang Fengrong et al. proposed that polyisobutylene with a molecular weight adjustable from 500 to 10,000, an α-double bond content ≥95%, and a MWD ≤2 can be synthesized using a metallocene catalyst system, but did not mention the specific type of catalyst (Wang Fengrong, Gao Meng, Zhang Chao et al. Research progress on highly active polyisobutylene catalysts, Refining & Chemical Industry, 2019, Vol. 2, pp. 3-4).

[0006] Patent application CN107417729A proposes a method for synthesizing monometallic compounds, using group IVB metal halides as raw materials and cyclopentadiene ligands in a molar ratio of 1:1.

[0007] Rosa Fandos et al. used a method based on intramolecular thermally induced CX bond activation of complexes containing neutral cyclopentadienyl ligands, employing tetramethyl-methoxypropyl-cyclopentadienyl titanium inneronium salt η 5 Using C5Me4(CH2)3OMe]TiCl2(CHPPh3) as a starting material, a bidentate cyclopentadienyl alkoxide ligand C5Me4(CH2)3OTiCl2 with a pseudo-tripod structure was synthesized. This ligand can catalyze olefin polymerization. (Fandos R, Meetsma A, Teuben J H. Intramolecular C-X Activation as a Synthetic Route to Bidentate Cyclopentadienyl-Alkoxide Ligands: Preparation and Molecular Structure of (3-(2,3,4,5-Tetramethylcyclopentadienyl)propoxy)titanium Dichloride[J]. Organometallics, 1991, 10(1): 59-60.)

[0008] A. Rajesh et al. used a handle-η 5 A monofluorofluorenyl cyclohexanoate zirconium (IV) complex / MAO catalytic system was used to synthesize polyethylene with different structures and mixtures of polyethylene with linear α-olefins and long-chain alkanes at 40–100 °C. The main catalyst structure was as follows: (Rajesh A,Sivaram S.Polymerization of ethylene tobranched poly(ethylene)s using ansa-η 5-monofluorenyl cyclohexanolatozirconium(IV)complex / methylaluminoxane[J].Polymer Bulletin,2011,67(3):383-399.) Bernhard Rieger reacted symmetrically substituted epoxides with fluorenyl lithium to obtain the corresponding alcohols and prepared compounds with the general formula: The catalyst, when combined with the co-catalyst Al(CH3)3, can catalyze the polymerization of ethylene. (Bernhard, Rieger. Preparation and some properties of chiral ansa-mono(η) 5 -fluorenyl)zirconium(IV)complexes[J]. Journal of Organometallic Chemistry, 1991.) Steven DR et al. synthesized the structure of

[0009] Monolithic titanium complexes were described, but their applications were not discussed. (SDR Christie, KWMan, RJ Whitby, et al. Novel Routes to Bidentate Cyclopentadienyl-Alkoxide Complexes of Titanium: Synthesis of (η 5 -σ-C5R 14 CHR2CH2CR3R4O)TiCl2[J].Organometallics, 1999.)

[0010] Alexander Rau et al. synthesized [η] with a handle-shaped semi-sandwich structure using two methods: a one-pot method and thermal decomposition of TiCl3 precursor. 5 :η 1 -C5H4-C(CH3)2-2-C6H4O]TiCl2, with the following structure: And it is used as the main catalyst, MAO or Al(i-Bu3) and [Me2PhNH] + [B(C6F5)4] -Ethylene polymerization and ethylene / 1-hexene copolymerization were carried out in a high-pressure reactor at 210 °C and 150 MPa using a co-catalyst. (SG Luft. Synthesis and application in high-pressure polymerization of a titanium complex with a linked cyclopentadienyl-phenoxide ligand[J]. Journal of Organometallic Chemistry, 2000.)

[0011] Esther E et al. prepared titanium complexes [η] with cyclopentadienyl-alkoxide auxiliary ligands. 5 η 1 -C5Me4(CH2)3O]TiR2 (R=Cl、Me、CH2Ph、CH2CMe3、CH2SiMe3) and used it to catalyze the polymerization of propylene to obtain atactic polypropylene. (Gielens E, Tiesnitsch JY, Hessen B, et al. Titanium Hydrocarbyl Complexes with a Linked Cyclopentadienyl-Alkoxide Ancillary Ligand;Participation of the Ligand in an Unusual Activation of a(Trimethylsilyl)methyl Group[J]. Organometallics, 1998, 17(9):1652-1654.)

[0012] Patent application CN110218272A discloses a method for synthesizing polyisobutylene and its copolymers, which employs... Polyisobutylene products with number-average molecular weights (Mn) ranging from 0.52 million to 678,000 were synthesized using organoboron compound catalysts at reaction temperatures ranging from -80℃ to 50℃ and reaction times ranging from 1 / 6 to 24 h.

[0013] Patent application CN106632768A and Yang Ke et al. (Research on the polymerization reaction of isobutylene initiated by monoclonal scandium, Yang Ke, Dalian University of Technology, D, 2019) disclose a type of rare earth butyl rubber and its preparation method. The method uses a monoclonal scandium catalyst system composed of Lewis base coordinated cyclopentadienyl scandium complex / organoboride catalyst / alkyl aluminum to synthesize polyisobutylene products with a number average molecular weight (Mn) of more than 18,000.

[0014] Patent application CN101130467A discloses a method for preparing lubricating oil base oil by catalytic oligomerization of α-olefins using a catalyst system consisting of a metallocene compound with a restricted geometry containing a phenoxy side chain as the main catalyst and alkylaluminoxanes and alkylaluminum / boron compounds as co-catalysts. This method involves directly adding the metallocene catalyst to a reactor containing α-olefins and stirring to catalyze the oligomerization reaction. The reaction mixture is filtered to remove the catalyst, then dilute hydrochloric acid is added, stirred, separated, dried, filtered, and distilled under reduced pressure to remove unreacted raw materials. The patent also mentions adding dilute hydrochloric acid to the reaction mixture, stirring, drying, filtering, and distilling under reduced pressure to remove unreacted raw materials. This method utilizes the principle that the catalyst is insoluble in olefins and their polymers for filtration and uses acid to terminate the reaction. Furthermore, this patent does not demonstrate that this catalyst system can synthesize highly active polyisobutylene.

[0015] Patent application CN104877049A discloses monocerotitanium complexes with sterically hindered aryloxy side chains. This patent describes a method for catalyzing the homopolymerization of ethylene and the copolymerization of ethylene / α-olefins using alkylaluminoxanes, alkylaluminum, alkylhalogenated aluminum, Ph3CB(C6F5)4, R4NB(C6F5)4, B(C6F5)3, or mixtures thereof as the main catalyst to obtain high molecular weight polymers. The patent describes a monoceramic titanium complex containing a sterically hindered aryloxy side chain, wherein the α-olefin is propylene, 1-butene, 1-hexene, 1-octene, or 1-decene; the alkylaluminum is trimethylaluminum, triethylaluminum, or triisobutylaluminum; the alkylaluminoxane is methylaluminoxane or modified methylaluminoxane; and the organoboron auxiliary agent is Ph3CB(C6F5)4, PhNMe2HB(C6F5)4, or B(C6F5)3. CN1431232A discloses a phenoxy-containing metallocene compound catalyst for the homopolymerization of ethylene and the copolymerization of ethylene / α-olefins to obtain high molecular weight polymers. The olefins mentioned are ethylene, propylene, isobutene, 1-butene, 1-hexene, 1-octene, 1-decene and other terminal olefins with fewer than 20 carbons, or conjugated or non-conjugated dienes or polyenes, styrene, norbornene or cyclohexene.

[0016] Patent application CN1431232A discloses a method for homopolymerization of ethylene and copolymerization of ethylene with olefins including isobutylene using a phenoxy-containing side-chain metallocene compound catalyst system. Summary of the Invention

[0017] The first objective of this invention is to provide a tetraarylethoxy side-chain monocerometallic compound.

[0018] A second objective of this invention is to provide a catalyst system comprising the aforementioned tetraarylethoxy side-chain monocerometallurgical compound.

[0019] A third objective of this invention is to provide a method for synthesizing polyolefins using the catalyst system described above.

[0020] To achieve the above objectives, the present invention adopts the following technical solution:

[0021] The first aspect of this invention provides a tetraarylethoxy side-chain monometallic compound with the following structural formula:

[0022]

[0023] Wherein, M is selected from Ti, Zr, or Hf;

[0024] Cp' is selected from cyclopentadienyl, substituted cyclopentadienyl, indene, substituted indene, fluorenyl, and substituted and fluorenyl groups;

[0025] The substituted cyclopentadienyl group is a mono- or poly-substituted cyclopentadienyl group, and the substituent is selected from alkyl, aryl, or alkylmethylsilyl groups;

[0026] Ar is selected from phenyl, monosubstituted phenyl and polysubstituted phenyl, wherein the substituent is an alkyl group from C1 to C18. Typical Ars include methylphenyl, ethylphenyl, butylphenyl, hexylphenyl, dodecylphenyl, octadecylphenyl, 2,4-dimethylphenyl or 2,4-ditert-butylphenyl.

[0027] X is selected from halogens, C1-C20 alkyl groups, C1-C20 alkoxy groups, dialkylamino groups, phenyl groups, benzyl groups, and trimethylsilylmethyl groups.

[0028] The tetraarylethoxy side-chain monocerometallurgical catalyst of the present invention exhibits good stability and high catalytic activity due to the steric hindrance of the four aromatic groups. Furthermore, the two carbon bridging groups give the catalyst the characteristic of a restricted geometric configuration catalyst. At the same time, the catalyst is also readily soluble in alkane solvent systems other than aromatic hydrocarbons.

[0029] In the tetraarylethoxy side-chain monocenocene compound of the present invention, preferably, M is Ti.

[0030] In the tetraarylethoxy side-chain monometallocene compound of the present invention, preferably, Cp' is selected from cyclopentadienyl, substituted cyclopentadienyl, indenyl and fluorenyl; more preferably, Cp' is selected from substituted cyclopentadienyl, and even more preferably tetramethylcyclopentadienyl.

[0031] In the tetraarylethoxy side-chain monocerometallic compound of the present invention, preferably, Ar is phenyl, methylphenyl, ethylphenyl, butylphenyl, hexylphenyl, dodecylphenyl, octadecylphenyl, 2,4-dimethylphenyl or 2,4-di-tert-butylphenyl; more preferably, it is phenyl.

[0032] In the tetraarylethoxy side-chain monocenocene compound of the present invention, preferably, X is selected from halogen, methyl, neopentyl, phenyl or benzyl, more preferably, X is selected from halogen, and even more preferably Cl.

[0033] A second aspect of the present invention provides a catalyst system, wherein the catalyst system comprises catalyst A, catalyst B and catalyst C;

[0034] Catalyst A is selected from the above-mentioned tetraarylethoxy side-chain monocerometallic compounds;

[0035] The catalyst B is selected from Ph3CB(C6F5)4, PhNMe2HB(C6F5)4, B(C6F5)3 and [(C n H 2n+1 )2NH(C m H 2m+1 One of [B(C6F5)4], where n is an integer from 2 to 20 and m is an integer from 1 to 20;

[0036] The catalyst C is selected from alkylaluminum compounds.

[0037] According to the catalyst system of the present invention, preferably, the molar ratio of catalyst A, catalyst B and catalyst C is 1:(1-2):(2-40).

[0038] In the catalyst system according to the present invention, preferably, n is selected from an integer from 4 to 18; m is 1 or 2, preferably 1.

[0039] According to the catalyst system of the present invention, preferably, the alkylaluminum compound is selected from one of trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, tri-n-decylaluminum and tri-n-dodecylaluminum; more preferably, it is triethylaluminum, triisopropylaluminum or triisobutylaluminum.

[0040] A third aspect of the present invention provides a method for synthesizing polyolefins, wherein the method uses the above-described catalyst system to catalyze the polymerization reaction of olefins to obtain the polyolefins.

[0041] According to the synthesis method of the present invention, preferably, the olefin is selected from one or more combinations of C2-C20 1-olefins. Specifically, the olefin may be selected from isobutylene, a combination of ethylene and propylene, a combination of ethylene, propylene and norbornene, a combination of ethylene, propylene and ethyleneide norbornene, a combination of ethylene and 1-hexene, a combination of ethylene and 1-octene, a combination of ethylene and norbornene, and a combination of ethylene and ethyleneide norbornene.

[0042] According to the synthesis method of the present invention, preferably, the olefin is isobutylene, and the polyolefin is polyisobutylene; the polyisobutylene has an α-olefin content ≥95%, a number-average molecular weight (Mn) of 300-10000, and a molecular weight distribution of 1-2.5.

[0043] According to the synthesis method of the present invention, preferably, the molar ratio of isobutylene to catalyst A is: (1 × 10⁻⁶) / ( ... 4 ~1×10 7 ): 1.

[0044] According to the synthesis method of the present invention, preferably, the polymerization reaction is carried out in a solvent; the solvent is selected from one or more combinations of C2-C12 straight-chain alkanes, C4-C12 isoalkanes, C3-C8 cycloalkanes, benzene, and toluene. More preferably, the solvent is hexane, cyclohexane, or toluene.

[0045] According to the synthesis method of the present invention, preferably, the polymerization reaction is carried out at a temperature of 0 to 100°C, for a time of 0.1 to 4 hours, and at a pressure of 0 to 2 MPa (gauge pressure).

[0046] According to the synthesis method of the present invention, preferably, after the polymerization reaction is completed, the method further includes: removing the catalyst, separating unreacted monomers, solvents and oligomers, to obtain polyisobutylene product.

[0047] A preferred embodiment of the present invention provides a method for synthesizing highly reactive polyisobutylene, comprising the following steps:

[0048] Polymerization reaction is carried out using isobutylene as raw material and the above catalyst system as catalyst. After the reaction is completed, the catalyst is removed and the unreacted monomers, solvents and oligomers are separated to obtain polyisobutylene. The number average molecular weight (Mn) of the polyisobutylene is 300 to 10,000, the molecular weight distribution is 1 to 2.5, and the content of α-double bonds (α-olefin content) at the chain ends is ≥95%.

[0049] Due to the high isomerization and significant steric hindrance of isobutylene, conventional metallocene catalyst systems are insufficient for catalyzing its polymerization. The metallocene catalyst system of this invention enables high-temperature, high-monomer-concentration polymerization of isobutylene. Because the tetraarylethoxy side-chain monometallic catalyst has a single active center, it effectively suppresses the α-olefin isomerization side reaction, significantly increasing the α-olefin content and reducing the molecular weight distribution of the polyisobutylene product. After polymerization, the catalyst is removed by inorganic acid washing, alkaline washing, or direct water washing. Then, the monomers, solvent, and oligomers are separated to obtain a qualified high-activity polyisobutylene product with a chain-terminal α-double bond content (α-olefin content) ≥95%, a number-average molecular weight (Mn) of 300–10000, and a molecular weight distribution of 1–2.5.

[0050] In this preferred embodiment, the more specific steps include:

[0051] (1) Refining of raw materials and solvents:

[0052] The solvent (e.g., cyclohexane) and isobutylene are dried to remove impurities, reducing the content of water, oxygen and other impurities to below 1 ppm, thus meeting the requirements of the metallocene catalyst system for the content of water, oxygen and other impurities.

[0053] (2) Polymerization reaction:

[0054] The polymerization reaction is carried out in a high-pressure reactor. First, the high-pressure reactor is heated, purged with high-purity nitrogen to remove water and oxygen, so that the reaction environment meets the requirements for catalyst use. Then, solvent, isobutylene and catalyst C (alkylaluminum) are added to the high-pressure reactor and stirred for a certain period of time to further remove trace amounts of water, oxygen and other impurities in the reaction system that can poison and deactivate the metallocene catalyst. Then, the temperature is raised to the reaction temperature, and catalyst A and catalyst B are added to carry out the polymerization reaction.

[0055] (3) Catalyst separation:

[0056] After the reaction is complete, unreacted isobutylene monomer is released from the vent tube, and the reaction product is released from the bottom of the vessel and collected. Inorganic acid solution is added to wash away the catalyst, and then alkaline washing-water washing or direct water washing is performed until neutral to obtain qualified intermediate product.

[0057] (4) Separation of solvent and oligomers:

[0058] The solvent was separated by distillation, and then the oligomers were separated by vacuum distillation under conditions of -0.8 to -0.1 MPa and 150 to 200 °C to obtain a highly active polyisobutylene product with a number average molecular weight (Mn) of 300 to 10000, a chain-terminal α-double bond content (α-olefin content) of ≥95%, and a molecular weight distribution of 1 to 2.5.

[0059] The polyolefin synthesis method provided in this application has the following advantages:

[0060] 1) The catalyst has high activity and requires less dosage, which can save on catalyst usage and reduce production costs.

[0061] 2) The catalyst has a single active center and no isomerization side reaction, thus enabling the production of highly active polyisobutylene with a number average molecular weight of 300-10000, a terminal α-double bond content (α-olefin content) of ≥95%, and a molecular weight distribution of ≤3. The product has a single structure and high reactivity, which greatly improves the quality of highly active polyisobutylene products, saves the amount and cost of downstream products, and solves the technical problem of relatively low α-olefin content (≤90%) in traditional technologies.

[0062] 3) The catalyst system in the synthesis method of this invention has good high temperature resistance, realizing the synthesis of highly active polyisobutylene under relatively high temperature conditions of 0 to 100℃ (compared to the reaction temperature of BF3 system of -30℃). Conventional cooling water can be used for heat removal, avoiding the harsh low temperature reaction conditions (around -30℃) of the existing technical route, and greatly reducing production energy consumption and cost.

[0063] 4) Compared with the traditional BF3 catalyst system, the catalyst system of this application is non-toxic, harmless, non-polluting, and non-corrosive, solving the technical problems of toxicity, harm, corrosion, and pollution in the traditional technical route and improving the working environment for employees.

[0064] 5) The product scheme is flexible and adjustable, enabling a single device to produce multiple product models. Attached Figure Description

[0065] Figure 1 This is the 1H NMR spectrum of the polyisobutylene product. Detailed Implementation

[0066] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0067] All numerical specifications in this invention (e.g., temperature, time, concentration, and weight, including ranges for each) are generally approximate values ​​that may be changed (+) or (-) in increments of 0.1 or 1.0. All numerical specifications are to be understood as being preceded by the term "about".

[0068] The isobutylene polymerization process in this embodiment of the invention includes:

[0069] (1) Refining of raw materials and solvents:

[0070] The solvent (e.g., cyclohexane) and isobutylene are dried to remove impurities, reducing the content of water, oxygen and other impurities to below 1 ppm, thus meeting the requirements of the metallocene catalyst system for the content of water, oxygen and other impurities.

[0071] (2) Polymerization reaction:

[0072] The polymerization reaction is carried out in a high-pressure reactor. First, the high-pressure reactor is heated, purged with high-purity nitrogen to remove water and oxygen, so that the reaction environment meets the requirements for catalyst use. Then, solvent, isobutylene and catalyst C (alkylaluminum) are added to the high-pressure reactor and stirred for a certain period of time to further remove trace amounts of water, oxygen and other impurities in the reaction system that can poison and deactivate the metallocene catalyst. Then, the temperature is raised to the reaction temperature, and catalyst A and catalyst B are added to carry out the polymerization reaction.

[0073] (3) Catalyst separation:

[0074] After the reaction is complete, the unreacted isobutylene monomer is released and the reaction product is released. The catalyst is removed by washing with commonly used inorganic acid solutions such as hydrochloric acid. Then, the product is washed with sodium hydroxide solution as an alkaline solution followed by water washing or directly washed with water until neutral to obtain a qualified intermediate product.

[0075] (4) Separation of solvent and oligomers:

[0076] The solvent is separated by atmospheric or vacuum distillation, and then the oligomers are separated by vacuum distillation at -0.8 to -0.1 MPa and 150 to 200 °C to obtain polyisobutylene products.

[0077] Example 1

[0078] This embodiment prepares a tetraarylethoxy side-chain monocerometallurgical compound: tetraphenylethoxy-tetramethylcyclopentadienyl titanium dichloride, including the following process:

[0079] (1) Synthesis of tetraphenylethylene oxide (Reference: Margherita Barbero, Silvano, Stefano Cadamuro, et al., o-Benzenedisulfonimide as Reusable) Acid Catalyst forAcid-Catalyzed Organic Reactions.Synthesis 2008,No.9,1379–1388)

[0080] 330 mg (1.5 mmol) of o-phenyl sulfonamide was added to a 100 mL solution of tetraphenyl ethylene glycol (5.50 g, 15 mmol) in toluene. The mixture was stirred at 90 °C for 2 hours. The toluene solvent was then distilled off. The crude product was purified by column chromatography (200 mesh silica gel, petroleum ether / dichloromethane (8 / 2 v / v) eluent) to give 4.60 g (13.6 mmol, 91% yield) of pure tetraphenyl ethylene oxide.

[0081] (2) Synthesis of tetraphenylhydroxyethyl-tetramethylcyclopentadiene

[0082] Tetramethylcyclopentadiene (611 mg, 5.0 mmol) was dissolved in 20 mL of diethyl ether. 2 mL of n-butyllithium solution (2.5 M toluene, 5.0 mmol) was slowly added to the solution at room temperature. After reacting for 2 hours, tetraphenylethylene oxide (1.742 g, 5.0 mmol) in diethyl ether (40 mL) was slowly added to the reaction solution under ice-water bath conditions. The mixture was stirred overnight at room temperature. The reaction was quenched with 50 mL of dilute hydrochloric acid (1 N), and the organic phase was separated. The organic phase was further washed twice with 40 mL of distilled water. The organic phase was dried over anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation. The crude product was purified by column chromatography (200 mesh silica gel column, petroleum ether / dichloromethane (8 / 2 v / v) eluent) to give 2.19 g (4.7 mmol, 93% yield) of pure tetraphenylhydroxyethyl-tetramethylcyclopentadiene.

[0083] (3) Synthesis of tetraphenylethoxy-tetramethylcyclopentadienyl titanium dichloride

[0084] Tetraphenylhydroxyethyl-tetramethylcyclopentadiene (2.000 g, 4.25 mmol) was dissolved in 50 mL of diethyl ether. 3.4 mL of n-butyllithium solution (2.5 M toluene, 8.50 mmol) was slowly added to the solution at room temperature, and the mixture was stirred overnight. Then, 10 mL of titanium tetrachloride (0.806 g, 4.25 mmol) diethyl ether solution was slowly added dropwise to the reaction mixture at -20 °C. The reaction mixture was then allowed to rise to room temperature by auto-ignition and stirred overnight. The solvent was removed by rotary evaporation, and the reaction product was dissolved in 30 mL of dichloromethane. Insoluble matter was filtered off. 20 mL of n-hexane was added to the solution until a precipitate began to form. The solution was then slowly concentrated or cooled to allow crystallization. The product was filtered off, and the solvent was removed under vacuum to give 1.025 g (1.74 mmol, 41% yield) of the pure complex.

[0085] Example 2

[0086] This embodiment uses the catalyst system of the present invention to catalyze the synthesis of polybutene, wherein the catalyst system includes catalyst A, catalyst B and catalyst C, as detailed below:

[0087] Catalyst A: Tetraphenylethoxy-tetramethylcyclopentadienyl titanium dichloride

[0088] Catalyst B: [(C 18 H 37 )2NHMe][B(C6F5)4]

[0089] Catalyst C: Al(iBu)3

[0090] Catalyst A was used at a dosage of 5 μmol, with a molar ratio of B / A = 2:1 and C / A = 40:1. Cyclohexane was used as the solvent at a dosage of 60 mL, and 102 g of isobutylene was added. The reaction was carried out at 40 °C for 2 h. After the reaction, unreacted monomers were separated, and the reaction product was released. The product was then washed successively with acid, alkali, and water until neutral, yielding a colorless and transparent intermediate product. The solvent and oligomers were removed by vacuum distillation to obtain a qualified high-activity polyisobutylene product. The product mass was weighed, and the α-terminated olefin content of the product was determined to be 98% using a 400.13 MHz proton nuclear magnetic resonance spectrometer. Figure 1 As shown, the peaks at 4.65 and 4.65 are characteristic peaks of α-hydrogen, and the peaks at 5.13-5.18 are characteristic peaks of β-hydrogen.

[0091] The molecular weight and molecular weight distribution of highly reactive polyisobutylene were determined using Agilent PL220 high-temperature gel permeation chromatography, and the results are shown in Table 1.

[0092] Comparative Example 2

[0093] This comparative example uses a catalyst system similar to that in the prior art to catalyze the synthesis of polybutene, wherein the catalyst system includes catalyst A, catalyst B, and catalyst C, as detailed below:

[0094] Catalyst A: R=CH3 (Reference literature for synthesis method: MargheritaBarbero, Silvano, Stefano Cadamuro, et al., o-Benzenedisulfonimide as Reusable Acid Catalyst for Acid-Catalyzed Organic Reactions.Synthesis 2008,No.9,1379–1388)

[0095] Catalyst B: [(C 18 H 37 )2NHMe][B(C6F5)4]

[0096] Catalyst C: Al(iBu)3

[0097] Catalyst A was used in an amount of 5 μmol, with a molar ratio of B / A = 2:1 and C / A = 40:1. Cyclohexane was used as the solvent in an amount of 60 mL, and 100 g of isobutylene was added. The reaction was carried out at 40 °C for 2 h. After the reaction was completed, the unreacted monomers were separated, and the reaction product was released. The product was then washed with acid, alkali, and water until neutral to obtain a colorless and transparent intermediate product. The solvent was removed by distillation under normal pressure, but no product was obtained.

[0098] Example 3

[0099] This embodiment uses the catalyst system of the present invention to catalyze the synthesis of polybutene, wherein the catalyst system includes catalyst A, catalyst B and catalyst C, as detailed below:

[0100] Catalyst A: Tetraphenylethoxy-tetramethylcyclopentadienyl titanium dichloride

[0101] Catalyst B: [(C8H 17 )2NHMe][B(C6F5)4]

[0102] Catalyst C: Al(iBu)3

[0103] Catalyst A was used at a concentration of 5 μmol, with a catalyst ratio of B / A of 2:1 and a C / A ratio of 40:1. Cyclohexane was used as the solvent at a concentration of 60 mL, and 99 g of isobutylene was added. The reaction was carried out at 40 °C for 2 h. After the reaction, unreacted monomers were separated, and the reaction product was released. The product was then washed with acid, alkali, and water until neutral to obtain a colorless and transparent intermediate product. The solvent and oligomers were removed by vacuum distillation to obtain a qualified high-activity polyisobutylene product. The product mass was weighed, and the α-terminal olefin content of the product was determined by 400.13 MHz proton NMR spectroscopy. The molecular weight and molecular weight distribution of the high-activity polyisobutylene were determined by Agilent PL220 high-temperature gel permeation chromatography. The results are shown in Table 1.

[0104] Example 4

[0105] This embodiment uses the catalyst system of the present invention to catalyze the synthesis of polybutene, wherein the catalyst system includes catalyst A, catalyst B and catalyst C, as detailed below:

[0106] Catalyst A: Tetraphenylethoxy-tetramethylcyclopentadienyl titanium dichloride

[0107] Catalyst B: [Ph3C][B(C6F5)4]

[0108] Catalyst C: Al(iBu)3

[0109] Catalyst A was used at a dosage of 5 μmol, with a molar ratio of B / A = 2:1 and C / A = 40:1. Toluene was used as the solvent at a dosage of 60 mL, and 99 g of isobutylene was added. The reaction was carried out at 40 °C for 2 h. After the reaction was completed, unreacted monomers were separated, and the reaction product was released. The product was then washed with acid, alkali, and water until neutral to obtain a colorless and transparent intermediate product. The solvent and oligomers were removed by vacuum distillation to obtain a qualified high-activity polyisobutylene product. The product mass was weighed, and the α-terminated olefin content of the product was determined by 400.13 MHz proton NMR spectroscopy. The molecular weight and molecular weight distribution of the high-activity polyisobutylene were determined by Agilent PL220 high-temperature gel permeation chromatography. The results are shown in Table 1.

[0110] Table 1. Product analysis results of Examples 2-4 and Comparative Example 2

[0111]

[0112] As shown in Table 1, the catalyst provided in this application has a number-average molecular weight (Mn) of 300 to 10,000, a molecular weight distribution of 1 to 2.5, and a high-activity polyisobutylene product with an α-double bond content (α-olefin content) of ≥95% at the chain end.

[0113] Examples 5-15

[0114] The catalyst system of this invention was used to catalyze the synthesis of polybutene, and the changes in reaction conditions are shown in Table 2. The specific details of the catalyst system and solvent are as follows:

[0115] Catalyst A: Tetraphenylethoxy-tetramethylcyclopentadienyl titanium dichloride

[0116] Catalyst B: [(C 18 H 37 )2NHMe][B(C6F5)4]

[0117] Catalyst C: Al(iBu)3

[0118] Solvent: Hexane

[0119] The specific conditions and results are shown in Table 2. In Table 2, IB refers to isobutylene, B / A refers to the molar ratio of catalyst B to catalyst A, and C / A refers to the molar ratio of catalyst C to catalyst A.

[0120] As shown in Table 2, the catalyst system of this application can synthesize polyisobutylene products with low molecular weight, high activity, and narrow molecular weight distribution.

[0121] Table 2. Reaction conditions and product analysis results of Examples 5-15

[0122]

[0123] Example 16

[0124] This embodiment uses the catalyst system of the present invention to catalyze the polymerization reaction of 1-decene, wherein the catalyst system includes catalyst A, catalyst B and catalyst C, as detailed below:

[0125] Catalyst A: Tetraphenylethoxy-tetramethylcyclopentadienyl titanium dichloride

[0126] Catalyst B: [Ph3C][B(C6F5)4]

[0127] Catalyst C: Al(iBu)3

[0128] Catalyst A was used in an amount of 5 μmol. The molar ratio of each catalyst was B / A = 2:1 and C / A = 40:1. Hexane was used as the solvent in an amount of 60 mL. 100 g of 1-decene was added. The reaction was carried out at 40 °C for 2 h. After the reaction was completed, the unreacted monomers were separated and the reaction product was released. The product was washed with acid, alkali and water until neutral to obtain a colorless and transparent intermediate product. The solvent and monomer dimer were removed by vacuum distillation to obtain 88 g of qualified poly-1-decene product. The viscosity at 100 °C was 230, the viscosity index was 225, and the pour point was -24 °C.

[0129] Therefore, the catalyst system of this application can be used for the polymerization of α-olefins such as 1-decene.

[0130] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A tetraaryl ethoxy side chain monometalated compound having the structure: ###0001### wherein: M is Ti; Cp' is selected from the group consisting of cyclopentadienyl, substituted cyclopentadienyl; said substituted cyclopentadienyl is mono- or poly-substituted cyclopentadienyl, the substituents being selected from the group consisting of alkyl; Ar is selected from the group consisting of phenyl, mono-substituted phenyl and poly-substituted phenyl, the substituents being C1-C18 alkyl; X is selected from the group consisting of halogen. wherein 2. A catalyst system comprising catalyst A, catalyst B and catalyst C; said catalyst A is selected from the group consisting of tetraaryl ethoxy side chain monometalated compounds of claim 1; said catalyst B is selected from the group consisting of alkyl aluminum compounds; said catalyst C is selected from the group consisting of alkyl aluminum compounds; the molar ratio of said catalyst A, catalyst B and catalyst C is 1:(1-2):(2-40).

3. The catalyst system of claim 2, wherein said catalyst A is selected from the group consisting of tetraaryl ethoxy side chain monometalated compounds of claim 1; said catalyst B is selected from the group consisting of alkyl aluminum compounds; said catalyst C is selected from the group consisting of alkyl aluminum compounds; the molar ratio of said catalyst A, catalyst B and catalyst C is 1:(1-2):(2-40).

4. The catalyst system of claim 3, wherein said alkyl aluminum compound is selected from the group consisting of one of trimethyl aluminum, triethyl aluminum, triisopropyl aluminum, triisobutyl aluminum, tri-n-hexyl aluminum, tri-n-octyl aluminum, tri-n-decyl aluminum and tri-n-dodecyl aluminum.

5. The catalyst system of claim 4, wherein said alkyl aluminum compound is selected from the group consisting of triethyl aluminum, triisopropyl aluminum or triisobutyl aluminum.

6. A synthetic method for preparing polyolefins, comprising the steps of: a) providing a catalyst system of any one of claims 2-5; b) providing an olefin; c) polymerizing said olefin in the presence of said catalyst system to obtain said polyolefin.

2. A catalyst system, wherein, 7. The synthetic method of claim 6, wherein said olefin is selected from the group consisting of one or more than two combinations of C2-C20 1-olefins.

8. The synthetic method of claim 7, wherein said olefin is selected from the group consisting of combinations of isobutylene, 1-decene, ethylene and propylene, ethylene, propylene and norbornene, ethylene, propylene and ethylidene norbornene, ethylene and 1-hexene, ethylene and 1-octene, ethylene and norbornene, ethylene and ethylidene norbornene. said catalyst B is selected from one of Ph3CB(C6F5)4, PhNMe2HB(C6F5)4, B(C6F5)3and [(C n H 2n+1 )2NH(C m H 2m+1 )][B(C6F5)4], n is selected from an integer from 2 to 20, m is selected from an integer from 1 to 20; 9. The synthetic method of claim 8, wherein said olefin is isobutylene and said polyolefin is polyisobutylene.

10. The synthetic method of claim 9, wherein said polyisobutylene has an alpha-olefin content of >95%, a number average molecular weight of 300-10000 and a molecular weight distribution of 1-2.

5.

3. The catalyst system of claim 2, wherein, 11. The synthetic method of claim 10, wherein said polymerization is carried out in a solvent.

4. The catalyst system of claim 2, wherein, 12. The synthetic method of claim 11, wherein said solvent is selected from the group consisting of one or more than two combinations of C2-C12 straight chain alkanes, C4-C12 isomeric alkanes, C3-C8 cycloalkanes, benzene and toluene.

5. The catalyst system of claim 2, wherein, 13. The synthetic method of claim 12, wherein said solvent is hexane, cyclohexane or toluene.

6. A process for the synthesis of polyolefins, wherein, 14. The synthetic method of claim 13, wherein said polymerization is carried out at a temperature of 0-100°C, a time of 0.1h-4h and a pressure of 0-2MPa.

7. The method of synthesis according to claim 6, wherein, ​ 8. The method of synthesis according to claim 6, wherein, ​ 9. The method of synthesis according to claim 6, wherein, ​ ​ 10. The method of synthesis according to claim 9, wherein, The molar ratio of said isobutene to said catalyst A is: (1 x 10 4 ~ 1 x 10 7 ) :

1.

11. The method of synthesis according to claim 9, wherein, ​ ​ 12. The method of synthesis according to claim 11, wherein, ​ 13. The method of synthesis of claim 9, wherein, ​

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