Olefin polymerization catalyst as well as preparation method and application thereof

Abstract

The complex as shown in the formula (I) is used for catalyzing polymerization of ethylene and alpha-olefin as a catalyst for olefin polymerization, and has the advantages of high polymerization activity, high temperature resistance, high alpha-olefin insertion rate, good insertion uniformity and narrow molecular weight distribution of the product.

Description

Technical Field

[0001] This invention belongs to the field of catalysts for olefin polymerization, and relates to an olefin polymerization catalyst, its preparation method, and its application. Background Technology

[0002] Polyolefins are the most produced and widely used synthetic polymer materials in history. Polyethylene and polypropylene are the two largest producers of polyolefins, accounting for two-thirds of global annual thermoplastic plastic production. Due to their advantages such as abundant raw material sources, low cost, excellent mechanical properties, and good chemical stability, they have been widely used in numerous fields including construction, automotive, aerospace, electronics, electrical engineering, packaging, daily necessities, and military. The development of polyolefin materials has greatly facilitated human production and life. However, with economic and social development, the performance requirements for polyolefin products are constantly increasing, and traditional polyolefin products can no longer meet the needs of many emerging and high-end application areas. Therefore, new polyolefin products, such as olefin block copolymers, are increasingly attracting attention from academia and industry.

[0003] The development of new polyolefin materials is closely related to catalyst innovation. The advent of Zn catalysts enabled the widespread production and application of polyethylene and polypropylene. The emergence of methylaluminoxane (MAO) in the 1980s allowed metallocene catalysts to be used in the industrial production of polyolefins. However, the demanding preparation processes of metallocene catalysts result in high production costs for metallocene polyolefins. Therefore, lower-cost non-metallocene catalysts have become a hot topic in polyolefin catalyst research in recent years. Developing non-metallocene catalysts suitable for preparing high-performance polyolefin elastomers is a relatively new research direction. Summary of the Invention

[0004] To improve the above-mentioned technical problems, the present invention provides a complex of formula (I):

[0005]

[0006] Each of R1, R2, and R3 may be the same or different, and they are independently selected from H and C. 1-10 Alkyl, C 1-10 Alkoxy, C 3-10 cycloalkyl;

[0007] M is selected from transition metals;

[0008] Each X is the same or different, and is selected independently from each other.

[0009] According to an embodiment of the present invention, each R1, R2, R3 may be the same or different, and is independently selected from H and C. 1-6 Alkyl groups; for example, H, methyl, ethyl, isopropyl, tert-butyl.

[0010] According to an embodiment of the present invention, M is selected from group IVB metals, such as Ti, Zr, and Hf.

[0011] According to an embodiment of the present invention, the coordination compound is selected from the following structures:

[0012]

[0013]

[0014] The present invention also provides a ligand compound represented by formula (II):

[0015]

[0016] Among them, R1, R2, and R3 independently have the definitions described above.

[0017] The present invention also provides a method for preparing the complex shown in formula (I), comprising reacting compound a with LiX to obtain the complex shown in formula (I);

[0018]

[0019] Among them, R1, R2, R3, M and X have the definitions described above independently of each other.

[0020] The present invention also provides the application of the complex shown in formula (I) above in catalysts for olefin polymerization.

[0021] The present invention also provides a catalyst for olefin polymerization, the catalyst comprising the complex shown in formula (I) above.

[0022] The present invention also provides a catalytic system comprising the complex shown in formula (I) above or comprising the catalyst for olefin polymerization described above.

[0023] According to an embodiment of the present invention, the catalytic system further includes a co-catalyst selected from at least one of aluminoxanes, alkylaluminum compounds, and organoboron compounds. Specifically, it can be a mixture of two or three of the above, and exemplaryly, it can be a mixture of aluminoxanes and alkylaluminum compounds, a mixture of aluminoxanes and organoboron compounds, a mixture of alkylaluminum compounds and organoboron compounds, or a mixture of aluminoxanes, alkylaluminum compounds, and organoboron compounds.

[0024] According to embodiments of the present invention, the aluminum oxane includes at least one selected from methylaluminoxane (MAO), modified methylaluminoxane, ethylaluminoxane, and isobutylaluminoxane. Specifically, the modified methylaluminoxane is, for example, triisobutylaluminum modified methylaluminoxane (MMAO).

[0025] According to an embodiment of the present invention, the alkylaluminum is selected from at least one of trimethylaluminum, triethylaluminum, and triisobutylaluminum.

[0026] According to an embodiment of the present invention, the organoboron compound is at least selected from Ph3CB(C6F5)4, B(C6F5)3, PhNMe2HB(C6F5)4, Ph3CB[(CF3)2C6H3]4 or a mixture of at least two of them.

[0027] According to an embodiment of the present invention, in the catalytic system, the molar ratio of the complex represented by formula (I) to aluminum oxane and / or alkyl aluminum is 1:500-2000, for example 1:500, 1:800, 1:1000, 1:1200, 1:1500 or 1:2000.

[0028] According to an embodiment of the present invention, in the catalytic system, the molar ratio of the complex represented by formula (I) to the organoboron compound is 1:0.5-5, for example, 1:0.8, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4 or 1:4.5.

[0029] According to an embodiment of the present invention, the catalytic system may include a solvent. Specifically, the solvent may be selected from alkanes, cycloalkanes, or aromatics, such as at least one selected from n-pentane, cyclopentane, n-hexane, cyclohexane, solvent oil (e.g., Isopar E), benzene, toluene, etc.

[0030] The present invention also provides a method for preparing a polyolefin elastomer, the method comprising polymerizing an olefin in the presence of the above-mentioned catalytic system to obtain a polyolefin elastomer.

[0031] According to an embodiment of the present invention, the polymerization reaction is carried out in the presence of a solvent. Specifically, the solvent may be the same as or different from the solvent in the catalytic system, and may be selected from alkanes, cycloalkanes, or aromatics, such as at least one selected from n-pentane, cyclopentane, n-hexane, cyclohexane, solvent oil (e.g., Isopar E), benzene, toluene, etc.

[0032] According to an embodiment of the present invention, the method includes the following steps:

[0033] The catalytic system is injected into the reactor, and olefins and hydrogen are introduced to carry out the polymerization reaction.

[0034] According to an embodiment of the present invention, a solvent is injected before the catalytic system is injected into the reactor.

[0035] According to an embodiment of the present invention, the olefin comprises ethylene and a comonomer; specifically, the comonomer is selected from at least one of α-olefins other than ethylene, and can be, for example, at least one of propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene or 1-octene.

[0036] According to an embodiment of the present invention, the temperature of the polymerization reaction is 40°C-180°C, exemplarily 120-150°C, and also, for example, 130-140°C. Specifically, for example, it is 60°C, 80°C, 100°C, 120°C, 140°C, or 160°C.

[0037] According to an embodiment of the present invention, the pressure of the polymerization reaction is 0.1 MPa-5 MPa, for example 0.5 MPa, 1.0 MPa, 1.5 MPa, 2.0 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa or 4.5 MPa.

[0038] Beneficial effects

[0039] The present invention provides a complex of formula (I) which has high polymerization activity as a catalyst for olefin polymerization of ethylene and α-olefin, and is resistant to high temperature (e.g., resistant to at least 180°C, and the polymerization reaction temperature can be 120-140°C, preferably 130-140°C), has a high α-olefin insertion rate, good insertion uniformity, and a narrow molecular weight distribution of the product.

[0040] In addition, in catalytic systems including the complex shown in formula (I), the cocatalyst can be selected from aluminoxanes and / or alkylaluminum, but can also be selected from organoboron compounds, which greatly expands the range of cocatalysts.

[0041] Furthermore, the addition of organoboron compounds to the catalytic system can further improve the α-olefin insertion rate and molecular weight distribution.

[0042] Terminology Definitions and Explanations

[0043] Unless otherwise stated, the definitions of groups and terms recorded in this application specification and claims, including definitions as examples, exemplary definitions, preferred definitions, definitions recorded in tables, and definitions of specific compounds in the examples, can be arbitrarily combined and combined with each other. Such combinations and combinations of group definitions and compound structures should be understood as being within the scope of this application specification and / or claims.

[0044] Unless otherwise stated, the numerical ranges described in this specification and claims are equivalent to describing at least each specific integer value therein. For example, the numerical range "1-10" is equivalent to describing each integer value, namely 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.

[0045] The term "halogen" refers to fluorine, chlorine, bromine, and iodine.

[0046] Term "C" 1-10 "Alkyl" should be understood as representing a straight-chain or branched saturated monovalent hydrocarbon group having 1 to 10 carbon atoms. For example, "C 1-6 "Alkyl" refers to straight-chain and branched alkyl groups having 1, 2, 3, 4, 5, or 6 carbon atoms. "C" 1-4 "Alkyl" means a straight-chain or branched alkyl group having 1, 2, 3, or 4 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl, or 1,2-dimethylbutyl, or their isomers.

[0047] Term "C" 1-10 "Alkoxy" should be understood as "C 1-10 Alkyl-O-”, where C 1-10 Alkyl groups have the definition described in this invention.

[0048] Term "C" 3-10 "Cycloalkyl" should be understood to refer to a saturated monovalent monocyclic, bicyclic (e.g., bridged, spirocyclic) hydrocarbon ring or tricyclic alkane having 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms, preferably "C". 3-8 "Cycloalkyl" or "C" 3-6 "Cycloalkyl". 3-10 Cycloalkyl groups can be monocyclic hydrocarbon groups, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, or cyclodecyl; or bicyclic hydrocarbon groups, such as borneolyl, indolyl, hexahydroindolyl, tetrahydronaphthyl, decahydronaphthyl, bicyclo[2.1.1]hexyl, bicyclo[2.2.1]heptyl, bicyclo[2.2.1]heptenyl, 6,6-dimethylbicyclo[3.1.1]heptyl, 2,6,6-trimethylbicyclo[3.1.1]heptyl, bicyclo[2.2.2]octyl, 2,7-diazaspiro[3,5]nonyl, 2,6-diazaspiro[3,4]octyl; or tricyclic hydrocarbon groups, such as adamantyl. Detailed Implementation Plan

[0049] The technical solutions of this disclosure will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of this disclosure and should not be construed as limiting the scope of protection of this disclosure. All technologies implemented based on the above content of this disclosure are covered within the scope of protection intended by this disclosure.

[0050] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0051] Preparation Example 1

[0052]

[0053] 20 g of compound 1a and 30.7 g of compound 1b were dissolved in 300 mL of ethylene glycol dimethyl ether. Under nitrogen protection, 1.2 g of tetrakis(triphenylphosphine)palladium and 17.5 g of potassium carbonate were added, and the mixture was heated to reflux for 8 h. After quenching the reaction with water, the mixture was filtered, and the filtrate was extracted with ethyl acetate. The organic phase was recovered and washed with saturated sodium bicarbonate and saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated. The crude product was eluted by silica gel column chromatography to give 20.4 g of compound 1c. ESIMS: m / z 240.8 ([M+H) + ).

[0054] 20 g of compound 1c was dissolved in 200 mL of acetonitrile, and then 9 mL of acetic acid was added at 0 °C, followed by 3.6 g of butanedione. The mixture was stirred for 1 hour at room temperature. The reaction was quenched with saturated ammonium chloride solution, and then extracted with ethyl acetate. The organic phase was recovered and washed with saturated sodium bicarbonate and saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated. The crude product was eluted by silica gel column chromatography to give 19.1 g of compound 1d. ESIMS: m / z 529.6 ([M+H) + ). 1 H NMR(400MHz, CDCl3-d)δ:7.96-7.92(s,2H),7.76-7.72(s,2H),7.56-7.42(m,4H ),7.28-7.20(m,6H),2.48-2.40(s,6H),2.08-2.02(s,6H),1.48-1.40(s,18H).

[0055] Under nitrogen atmosphere and at -78°C, 6 mL of 2.5 M butyllithium n-hexane solution was added to 50 mL of tetrahydrofuran solution containing 5 g of compound 1d. The mixture was stirred at room temperature for 10 hours. The temperature was then lowered to -78°C, and a mixture of 2.64 g of zirconium tetrachloride and 8 mL of tetrahydrofuran solution was slowly added dropwise to the reaction mixture. The mixture was stirred for 6 hours, the solvent was removed, the solution was washed with toluene, filtered, and the filtrate was concentrated to give 4.6 g of complex 1. ESIMS: m / z 727.6 ([M+H) + ).

[0056] At room temperature, a pentane solution (8.30 mmol) of LiCH₂TMS was added to a suspension of compound 1e (2 g) in 60 mL of diethyl ether. The reaction mixture was stirred overnight, then filtered and concentrated under reduced pressure to give compound 1. ESIMS: m / z 882.5 ([M+H) + Elemental analysis: C50H77N2Si3Zr Theoretical values: C, 68.12; H, 8.80; N, 3.18; Measured values: C, 67.23; H, 9.11; N, 3.46. 1 H NMR(400MHz, CDCl3-d)δ:8.08-8.02(s,2H),7.86-7.82(s,2H),7.64-7.60(m,4H),7.42-7.38(m,6H ),2.54-2.46(s,6H),2.16-2.09(s,6H),1.50-1.42(s,18H),0.74-0.68(s,6H),0.30-0.20(s,27H).

[0057] Preparation Example 2

[0058] Complexes 2-3 were prepared according to the method of Preparation Example 1, as detailed in Table 1.

[0059] Table 1. Structural formulas and characterization data of coordination compounds 2-3

[0060]

[0061]

[0062] Example

[0063] Catalyst preparation: Using the complex obtained in the above preparation example as the catalyst, it was dissolved in toluene to prepare an 8% (w / w) catalyst solution; a certain amount of organoboron compound was dissolved in toluene to prepare an 8% (w / w) borate solution; the aluminum element in the triisobutylaluminum-modified methylaluminoxane (MMAO) solution and the methylaluminoxane solution was 7% (w / w). The corresponding catalytic system was prepared according to the composition in Table 2, in which the catalyst:Al ratio was 1:1200 and the catalyst:B:Al ratio was 1:1:1200.

[0064] Table 2 Catalysts and co-catalysts in the catalytic systems of Examples 1-7

[0065] Example catalyst Organoboron compounds (B) Aluminum-containing co-catalyst (Al) Example 1 Complex 1 / MMAO Example 2 Complex 2 / MMAO Example 3 Complex 3 / MMAO Example 4 Complex 1 <![CDATA[Ph3CB(C6F5)4]]> MMAO Example 5 Complex 1 <![CDATA[Ph3CB(C6F5)4]]> Triethylaluminum Example 6 Complex 1 <![CDATA[Ph3CB(C6F5)4]]> Methylaluminoxane (MAO)

[0066] Test Example 1: Ethylene / 1-hexene polymerization reaction

[0067] Aggregation conditions:

[0068] (1) Under a nitrogen atmosphere, add 20 mL of Isopar E solvent to a 350 mL polymerization reactor, then connect the reactor to the polymerization reaction device, use a vacuum pump to evacuate for more than 5 minutes to remove oxygen from the pipeline of the polymerization device, and adjust the temperature control device to make the reaction temperature 30℃.

[0069] (2) Inject the catalyst system containing 1 μmol of catalyst into the reaction apparatus. After injection, close the valve and introduce 1-hexene comonomer into the reactor. Then add hydrogen gas and finally continuously introduce ethylene to keep the total polymerization pressure constant at 2.0 MPa. React at 120°C for 0.5 h.

[0070] (3) Terminate the reaction, cool to room temperature, and test the yield and related properties of the polymer product, as shown in Table 3.

[0071] Table 3 Polymerization activity and related properties of Examples 1-6

[0072]

[0073]

[0074] Test Example 2: Ethylene / 1-Octene Polymerization

[0075] Referring to the method in Test Example 1, except that the comonomer was replaced with 1-octene, the ethylene / 1-octene polymerization reaction was catalyzed using the catalyst system of Example 4. The ethylene insertion rate in the polymer was measured to be 20.3%, and the polymerization activity was 15.5 × 10⁻⁶. 6 g / (mol·h).

[0076] The results above show that the catalyst of the present invention has high polymerization activity, high α-olefin insertion rate, and good insertion uniformity. Adding organoboron compounds to the reaction system can further improve the α-olefin insertion rate and obtain polyolefins with a narrow molecular weight distribution.

[0077] The above description provides an exemplary illustration of the implementation scheme of the technical solution disclosed herein. It should be understood that the scope of protection of this disclosure is not limited to the above-described implementation scheme. Any modifications, equivalent substitutions, or improvements made by those skilled in the art within the spirit and principles of this disclosure should be included within the scope of protection of the claims of this application.

Claims

1. A complex of formula (I): in, Each of R1, R2, and R3 may be the same or different, and they are independently selected from H and C. 1-10 Alkyl, C 1-10 Alkoxy, C 3-10 cycloalkyl; M is selected from transition metals; Each X is the same or different, and is selected independently from each other.

2. The complex according to claim 1, characterized in that, Each of R1, R2, and R3 may be the same or different, and they are independently selected from H and C. 1-6 Alkyl groups; for example, H, methyl, ethyl, isopropyl, tert-butyl; Preferably, M is selected from group IVB metals, such as Ti, Zr, and Hf; Preferably, the complex is selected from the following structures:

3. The method for preparing the complex according to claim 1 or 2, comprising reacting compound a with LiX to obtain the complex shown in formula (I); in, R1, R2, R3, M, and X each have the definition as described in claim 1 or 2.

4. A ligand compound represented by formula (II): in, R1, R2, and R3 independently have the definitions described in claim 1 or 2.

5. The use of the complex according to claim 1 or 2 in catalysts for olefin polymerization.

6. A catalyst for olefin polymerization, comprising the complex according to claim 1 or 2.

7. A catalytic system comprising the complex of claim 1 or 2 or the catalyst for olefin polymerization of claim 6.

8. The catalytic system according to claim 7, characterized in that, The catalytic system also includes a co-catalyst, which is selected from at least one of aluminoxane, alkylaluminum, and organoboron compounds; Preferably, the aluminum oxane includes at least one of methylaluminoxane (MAO), modified methylaluminoxane, ethylaluminoxane, and isobutylaluminoxane; specifically, the modified methylaluminoxane is, for example, triisobutylaluminum modified methylaluminoxane (MMAO). Preferably, the alkylaluminum is selected from at least one of trimethylaluminum, triethylaluminum, and triisobutylaluminum; Preferably, the organoboron compound is selected from at least Ph3CB(C6F5)4, B(C6F5)3, PhNMe2HB(C6F5)4, Ph3CB[(CF3)2C6H3]4 or a mixture of at least two of them; Preferably, in the catalytic system, the molar ratio of the complex to aluminum oxane and / or alkyl aluminum is 1:500-2000; Preferably, in the catalytic system, the molar ratio of the complex to the organoboron compound is 1:0.5-5.

9. A method for preparing a polyolefin elastomer, the method comprising polymerizing an olefin in the presence of the catalytic system of claim 7 or 8 to obtain the polyolefin elastomer.

10. The preparation method according to claim 9, characterized in that, The olefin includes ethylene and a comonomer; preferably, the comonomer is selected from at least one of α-olefins other than ethylene, and preferably, the comonomer can be at least one of propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene or 1-octene; Preferably, the polymerization reaction is carried out at a temperature of 40°C to 180°C. Preferably, the pressure of the polymerization reaction is 0.1 MPa-5 MPa.

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