Metallocene complex as well as preparation method and application thereof

Abstract

The invention discloses a metallocene complex as well as a preparation method and application thereof. The metallocene complex has a structure as shown in a formula I. When the metallocene complex is matched with a cocatalyst (such as MAO), the catalytic activity of a polymer can be remarkably improved. Even at the temperature of up to 160 DEG C, the complex provided by the invention still has relatively high catalytic activity.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to a metallocene complex, its preparation method, and its application as a catalyst in the homopolymerization or copolymerization of ethylene. Background Technology

[0002] Olefin polymerization catalyst systems can be classified into Ziegler-Natta catalysts and metallocene catalysts, and these highly active catalyst systems have been developed based on their characteristics. Ziegler-Natta catalysts have been widely used in commercial processes since their development in the 1950s. However, because Ziegler-Natta catalysts are multi-site catalysts containing multiple active sites, they result in polymers with a wide molecular weight distribution. Furthermore, due to the non-uniform compositional distribution of the comonomers, it is difficult to obtain the desired physical properties.

[0003] Meanwhile, metallocene catalysts include main catalysts with transition metal compounds as the main component and co-catalysts with organometallic compounds with aluminum as the main component. Using metallocene catalysts can yield polyolefin elastomers with very uniform molecular weight and chemical composition distributions, and the molecular structure and molecular weight of the polymer can be highly controlled by adjusting the catalyst structure.

[0004] Metallocene catalysts used for olefin polymerization include single-center and multi-center types. Multi-center metallocene dual-bridge catalysts exhibit high olefin polymerization activity at a lower Al / M (M is a group IVB metal) ratio, which can significantly reduce the amount of co-catalyst required. Therefore, research on restricted configuration dual-bridge metallocenes is very active, striving to develop new restricted configuration dual-bridge metallocene catalysts with higher activity, lower cost, and wider applications to meet the needs of polyolefin industrial production. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention provides a metallocene complex having the structure shown in Formula I:

[0006]

[0007] In formula I, M 1 and M 2 For Ti or Zr;

[0008] R1 is selected from H and C. 1-10 Alkyl, C 6-10 Aryl or C 7-10 Aryl groups;

[0009] R2 is selected from C 1-10 Alkyl, C 2-10 alkenyl, C 7-10 Aryl alkyl, or C6-10 cycloalkyl or C 6-10 Aryl;

[0010] R3 or R4 may be the same or different, and are independently selected from C. 6-10 Aryl or C 6-10 Cycloalkyl.

[0011] According to an embodiment of the present invention, R1 is selected from H and C. 1-6 Alkyl, C 6-10 Aryl or C 7-10 Aryl groups;

[0012] R2 is selected from C 1-6 Alkyl, C 2-6 alkenyl, C 7-10 Aryl alkyl, or C 6-10 cycloalkyl or C 6-10 Aryl;

[0013] R3 or R4 may be the same or different, selected from C 6-10 Aryl or C 6-10 Cycloalkyl.

[0014] According to an embodiment of the present invention, R1 is selected from H, methyl, ethyl, propyl, butyl, phenyl or benzyl.

[0015] According to an embodiment of the present invention, R2 is selected from H, methyl, ethyl, propyl, butyl, phenyl or benzyl.

[0016] According to embodiments of the present invention, R3 or R4 may be the same or different, and are selected independently from phenyl, benzyl or cyclohexane.

[0017] As a preferred embodiment of the present invention, the metallocene complex has one of the following structural formulas:

[0018]

[0019] This invention also provides a method for preparing the above-mentioned metallocene complex, the method comprising the following steps:

[0020] The compound shown in Formula II is reacted with R2CpM 2 The cyclopentadienyl compound of Cl3 reacts in the presence of an organic solvent to give the compound shown in Formula I;

[0021]

[0022] R1, R2, R3, R4, M 1 Or M 2 With the above meaning, Cp stands for cyclopentadienyl.

[0023] According to an embodiment of the present invention, the compound represented by Formula II reacts with R2CpM 2 The molar ratio of Cl3 to cyclopentadienyl compounds is 1:(1-3).

[0024] According to an embodiment of the present invention, the reaction temperature of the method is 130-160 degrees Celsius, and the reaction time is 6-48 hours.

[0025] According to an embodiment of the present invention, the organic solvent is selected from at least one of petroleum ether, THF, n-hexane, dichloromethane, toluene, etc. The content of the organic solvent is not particularly limited, as long as it is sufficient to dissolve the raw materials.

[0026] According to an embodiment of the present invention, the compound represented by Formula II is prepared as follows:

[0027] The compound shown in Formula III is reacted with R2CpM 2 The cyclopentadienyl compound of Cl3 reacts in the presence of an organic solvent to give the compound shown in Formula II;

[0028]

[0029] According to an embodiment of the present invention, the compound represented by Formula III reacts with R2CpM 2 The molar ratio of Cl3 to cyclopentadienyl compounds is 1:(1-3).

[0030] According to an embodiment of the present invention, in the preparation of the compound represented by Formula II, the reaction temperature is 100-180 degrees Celsius; the reaction time is 12-48 h.

[0031] The present invention also provides the use of the metallocene complexes shown in Formula I as described above as catalysts for the homopolymerization of ethylene or the copolymerization of ethylene with other monomers.

[0032] According to an embodiment of the present invention, the other monomers are selected from at least one of α-olefins (excluding ethylene), cycloolefins, borneol and its derivatives.

[0033] For example, the other monomers are selected from at least one of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, norbornene, norbornediene, ethylidene norbornene, phenyl norbornene, vinyl norbornene, dicyclopentadiene, 1,4-butadiene, 1,5-pentadiene, 1,6-hexadiene, styrene, α-methylstyrene, divinylbenzene, and 3-chloromethylstyrene.

[0034] The present invention also provides a catalyst composition for catalyzing the homopolymerization of ethylene or copolymerization with other monomers, the composition comprising a metallocene complex as shown in Formula I above and a cocatalyst.

[0035] According to an embodiment of the present invention, the co-catalyst is selected from at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylaluminum chloride, triisopropylaluminum, trisec-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylmethoxyaluminum, dimethylethoxyaluminum, trimethylboron, triethylboron, triisobutylboron, tripropylboron, and tributylboron.

[0036] According to an embodiment of the present invention, in the composition, the molar ratio of the metallocene complex represented by Formula I to the cocatalyst is 1:500-2500, for example, 1:500, 1:1000, 1:2000, 1:1500, 1:1800, 1:2000, 1:2200, 1:2400 or 1:2500.

[0037] According to embodiments of the present invention, the reaction temperature for the catalyst composition to catalyze the homopolymerization of ethylene or its copolymerization with other monomers is from 0°C to 160°C, for example, from 50°C to 160°C, or from 50°C to 100°C. Examples include 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, or 160°C.

[0038] The beneficial effects of this invention are:

[0039] This invention provides a metallocene complex, its preparation method, and its applications. The metallocene complex, when combined with a cocatalyst (e.g., MAO), can significantly enhance the catalytic activity of polymers. Even at temperatures as high as 160°C, the complex of this invention still exhibits high catalytic activity.

[0040] In addition, in catalytic systems including the complex shown in Formula I, the cocatalyst can be selected from alkylaluminum, but it can also be selected from organoboron, which greatly expands the range of cocatalysts. Detailed Implementation

[0041] The technical solution of the present invention 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 the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0042] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0043] Example 1

[0044] Preparation of metallocene complex of formula I-1:

[0045]

[0046] (S1) 0.1 mol Dissolve the compound in 100 mL of n-hexane, and add a 0.2 mol n-butyllithium solution in n-hexane (concentration 0.05 M) dropwise at -10 to -20 °C. React overnight at room temperature. After the reaction is complete, filter to remove the solvent and dry the product. Dissolve 0.1 mol of the product (i.e., the compound shown in Formula III) in 200 mL of toluene, add 0.2 mol cyclopentadienyl titanium trichloride·ethylene glycol dimethyl ether, stir at room temperature for 24 h, centrifuge, and extract the residue with dichloroethane. Combine the centrifuged liquid and the extract, concentrate until a solid appears, and obtain the compound shown in Formula II, where R3 and R4 are both phenyl groups.

[0047] (S2) 0.1 mol of the compound shown in Formula II was mixed with 0.2 mol of cyclopentadienyl titanium trichloride CpTiCl3 in 150 mL of toluene and reacted at 140 °C for 24 h. After cooling the reaction solution to room temperature, it was filtered and concentrated to obtain the metallocene complex shown in Formula I-1 above.

[0048] The NMR analysis data for Equation I-1 are as follows: 1 H NMR (300MHz, DMSO-d6) δ7.50-7.37(m,10H),6.50-6.40(m,16H),2.90(m,4H),2.65(m,2H).

[0049] Example 2

[0050] Preparation of metallocene complex I-2:

[0051]

[0052] The difference between Example 2 and Example 1 is that: the raw materials... Replace with The above-mentioned metallocene complex I-2 was prepared.

[0053] The NMR analysis data for Equation I-2 are as follows: 1H NMR (300MHz, DMSO-d6) δ6.50-6.40(m,16H),2.90(m,4H),2.65(m,2H),1.53-1.24(m,20H),1.19(m,2H).

[0054] Example 3

[0055] Preparation of metallocene complex I-3:

[0056]

[0057] The difference between Example 3 and Example 1 is that the raw materials are... Replace with The above-mentioned metallocene complex, formula I-3, was prepared.

[0058] The NMR analysis data for Equation I-3 are as follows: 1 H NMR (300MHz, DMSO-d6) δ7.41(m,4H),7.26(m,4H),6.50-6.40(m,16H),2.90(m,4H),2.65(m,2H),2.37(s,6H).

[0059] Comparative Example 3

[0060] Preparation of metallocene complex A:

[0061]

[0062] The difference between Comparative Example 1 and Example 1 is as follows:

[0063] (S1) Take the raw materials from step (S1) Replace with

[0064]

[0065] (S2) Replace cyclopentadienyl titanium trichloride CpTiCl3 in step (S2) with methylcyclopentadienyl titanium trichloride MeCpTiCl3 to prepare the above metallocene complex of formula A.

[0066] Application Example 1

[0067] The complexes obtained in Examples 1-3 and Comparative Example 1 were used as catalysts to catalyze the polymerization of ethylene in the presence of a co-catalyst. The specific reaction steps are as follows:

[0068] The polymerization reaction was carried out in a 100 mL dry stainless steel autoclave, which was heated at 120 °C under vacuum for 30 minutes and then cooled to the reaction temperature under an ethylene atmosphere. Appropriate amounts of MAO (10 wt% toluene solution) and toluene were added to the reactor, followed by saturation with ethylene for 20 minutes. After reaching isothermal equilibrium, a toluene solution of catalyst was added to the reactor, and ethylene was introduced at the desired pressure to initiate polymerization. After stirring the reaction mixture to the desired reaction time, the ethylene pressure in the autoclave was slowly released, and then 15 mL of ethanol was added dropwise to terminate the polymerization. The resulting mixture was poured into 50 mL of 10% HCl ethanol solution. The resulting polymer product was collected by filtration, washed with 10% HCl ethanol solution, and then dried under vacuum at 65 °C for 10 hours to constant weight. The polymer mass was then weighed. The catalytic results of the complex are shown in Table 1.

[0069] Table 1 Results under co-catalysis with MAO co-catalyst

[0070]

[0071] Application Example 2

[0072] The difference between Application Example 2 and Application Example 1 is:

[0073] The cocatalyst MAO used in Application Example 1 was replaced with triethylboron, and the catalytic results of the complex are shown in Table 2.

[0074] Table 2 Results under the co-catalysis of triethylboron co-catalyst

[0075]

[0076]

[0077] The embodiments of the present invention have been described above by way of example. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A metallocene complex, characterized in that, It has the structure shown in Equation I: In formula I, M 1 and M 2 For Ti or Zr; R1 is selected from H and C. 1-10 Alkyl, C 6-10 Aryl or C 7-10 Aryl groups; R2 is selected from C 1-10 Alkyl, C 2-10 alkenyl, C 7-10 Aryl alkyl, or C 6-10 cycloalkyl or C 6-10 Aryl; R3 or R4 may be the same or different, and are independently selected from C. 6-10 Aryl or C 6-10 Cycloalkyl.

2. The metallocene complex according to claim 1, characterized in that, R1 is selected from H and C. 1-6 Alkyl, C 6-10 Aryl or C 7-10 Aryl groups; R2 is selected from C 1-6 Alkyl, C 2-6 alkenyl, C 7-10 Aryl alkyl, or C 6-10 cycloalkyl or C 6-10 Aryl; R3 or R4 may be the same or different, selected from C 6-10 Aryl or C 6-10 Cycloalkyl.

3. The metallocene complex according to claim 1, characterized in that, The metallocene complex has one of the following structural formulas:

4. The method for preparing the metallocene complex according to any one of claims 1-3, characterized in that, The method includes the following steps: The compound shown in Formula II is reacted with R2CpM 2 The cyclopentadienyl compound of Cl3 reacts in the presence of an organic solvent to give the compound shown in Formula I; R1, R2, R3, R4, M 1 Or M 2 With the above meaning, Cp stands for cyclopentadienyl.

5. The method according to claim 4, characterized in that, The compound shown in Formula II and R2CpM 2 The molar ratio of Cl3 to cyclopentadienyl compounds is 1:(1-3).

6. The method according to claim 4, characterized in that, The reaction temperature of the method is 130-160 degrees Celsius, and the reaction time is 6-48 hours.

7. Use of the metallocene complex according to any one of claims 1-3 as a catalyst for the homopolymerization of ethylene or the copolymerization of ethylene with other monomers. Preferably, the other monomers are selected from at least one of α-olefins (excluding ethylene), cycloolefins, borneol and their derivatives. Preferably, the other monomers are selected from at least one of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, norbornene, norbornediene, ethylidene norbornene, phenyl norbornene, vinyl norbornene, dicyclopentadiene, 1,4-butadiene, 1,5-pentadiene, 1,6-hexadiene, styrene, α-methylstyrene, divinylbenzene, and 3-chloromethylstyrene.

8. A catalyst composition for catalyzing the homopolymerization of ethylene or its copolymerization with other monomers, characterized in that, The composition comprises the metallocene complex of Formula I as described in any one of claims 1-3 and a cocatalyst.

9. The catalyst composition according to claim 8, characterized in that, The co-catalyst is selected from at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylaluminum chloride, triisopropylaluminum, trisec-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylmethoxyaluminum, dimethylethoxyaluminum, trimethylboron, triethylboron, triisobutylboron, tripropylboron, and tributylboron.

10. The catalyst composition according to claim 8, characterized in that, In the composition, the molar ratio of the metallocene complex of Formula I to the cocatalyst is 1:500-2500. Preferably, the reaction temperature for the catalyst composition to catalyze the homopolymerization of ethylene or copolymerization with other monomers is from 0°C to 160°C.

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