A method for preparing saturated metallocene polyalphaolefin

Abstract

The invention discloses a method for preparing a saturated metallocene poly-alpha-olefin. The preparation method comprises: polymerizing an alpha-olefin monomer in the presence of a metallocene catalyst and an activator, then removing unreacted monomers, and adding hydrogen for hydrogenation reaction. The method of the invention does not require the addition of an additional catalyst, saves equipment investment and raw material costs, and does not cause saturation and loss of raw materials. The prepared saturated metallocene poly-alpha-olefin has excellent performance.

Description

Technical Field

[0001] The invention relates to a method for preparing saturated metallocene poly-alpha-olefin. Background Art

[0002] Poly-alpha-olefins (PAO) are fully synthetic hydrocarbon lubricant base oils prepared by chemical synthesis. They have the advantages of high viscosity index, excellent low temperature performance, good thermal oxidation stability, low volatility, and good shear stability. They are currently considered to be the most promising fully synthetic lubricant base oils. PAO is usually catalyzed by traditional catalysts such as Lewis acid or Zieger-Natta catalysts for polymerization, such as BF3 for low viscosity PAO, AlCl3 for medium viscosity PAO, and Zieger-Natta for high viscosity PAO. Metallocene poly-alpha-olefins (mPAO) are products with comb-like structures and no upright side chains obtained by metallocene catalyst-catalyzed alpha-olefin polymerization. This structure affects the performance of PAO products. Compared with traditional PAO, mPAO usually has improved rheological properties and flow characteristics, can provide better shear stability, lower pour point and higher viscosity index, and has good viscosity-temperature characteristics. These characteristics determine that mPAO can be used in highly demanding environments, including powertrain and gear oils, compressor lubricants, transmission fluids and industrial lubricants. As society's requirements for energy efficiency and ecological protection become increasingly higher, people's demand for high-performance mPAO lubricant base oils is increasing.

[0003] mPAO is prepared by metallocene-catalyzed α-olefins, which contain double bonds in their structure. In order to improve the antioxidant properties of mPAO, mPAO must be hydrogenated and saturated.

[0004] CN105008409B discloses a method for producing an α-olefin polymer and a hydrogenated α-olefin polymer. It discloses adding hydrogen during the polymerization process. Adding hydrogen during the polymerization process easily causes the problem of saturation of the raw materials. Although it discloses hydrogenating the prepared α-olefin polymer, it does not disclose a specific hydrogenation scheme.

[0005] CN104370675B discloses a method for preparing poly-alpha-olefin in a continuous manner, but it requires the addition of a catalyst. For example, in Example 17, 0.5 wt% (based on the total weight of the poly-alpha-olefin to be hydrogenated) of BASF Ni-5249 catalyst is added thereto, hydrogen is introduced thereto until the hydrogen pressure reaches 4.0 MPa, the reactor is heated to 200° C., and the reaction is carried out at this temperature for 3 hours. The use of a hydrogenation catalyst, such as nickel, increases equipment investment and raw material costs.

[0006] In summary, there are currently two main methods for hydrogenating saturated mPAO. One is to use a hydrogenation catalyst, such as nickel or other precious metal inorganics, for fixed bed or kettle hydrogenation; the other is to add hydrogen to adjust the molecular weight during the polymerization process to prepare saturated mPAO. The former hydrogenation method increases equipment investment and raw material costs, while the latter easily causes the raw materials to be saturated. Therefore, it is necessary to find an economical and affordable method for hydrogenating saturated mPAO. Summary of the invention

[0007] In view of the above problems existing in the prior art, the present invention provides a novel method for preparing saturated metallocene poly-alpha-olefins. The method of the present invention uses the catalytic hydrogenation saturation characteristics of the polymerization catalyst metallocene compound itself to saturate the double bonds in the mPAO structure by adding hydrogen. Therefore, the method of the present invention does not need to add additional catalysts, saves equipment investment and raw material costs, and does not cause saturation and loss of raw materials. The prepared saturated metallocene poly-alpha-olefin has excellent performance.

[0008] The first aspect of the present invention provides a method for preparing saturated metallocene poly-α-olefin, comprising: polymerizing α-olefin monomers in the presence of a metallocene catalyst and an activator, then removing unreacted monomers, and adding hydrogen for hydrogenation reaction.

[0009] According to some embodiments of the preparation method of the present invention, preferably, the conditions of the hydrogenation reaction include: temperature of 50-150° C., time of 0.5-12 h, and hydrogen pressure of 0.1-2 MPa.

[0010] According to some embodiments of the preparation method of the present invention, preferably, the method for removing unreacted monomers is reduced pressure distillation.

[0011] According to some embodiments of the preparation method of the present invention, preferably, the α-olefin is selected from one or more of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecaene and 1-eicosene, preferably one or more of 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene and 1-tetradecene.

[0012] According to some embodiments of the preparation method of the present invention, preferably, the metallocene catalyst is selected from dimethylsilylbis-n-propylcyclopentadienyl zirconium dichloride, dimethylsilylbis-indenyl zirconium dichloride, diethylsilylbis-indenyl zirconium dichloride, diphenylsilylbis(4,7-dimethylindenyl) zirconium dichloride, dimethylsilylbis(4,7-dimethylindenyl) zirconium dichloride, dimethylsilylbis-indenyl zirconium dichloride, diphenylsilylbis(2-methylcyclopentadienyl) zirconium dichloride, ethylenebis-indenyl zirconium dichloride, ethylenebis-(2-methylindenyl) zirconium dichloride, dimethylsilylbis(2-methyl-3-butylcyclopentadienyl) Zirconium dichloride, dimethylsilylbiscyclopentadienyl zirconium dichloride, diethylmethylenecyclopentadienyl (3,5-dimethylphenylindenyl) zirconium dichloride, diethylmethylenecyclopentadienyl (4,7-dimethylindenyl) zirconium dichloride, dimethylmethylenecyclopentadienyl (4,7-dimethylindenyl) zirconium dichloride, dimethylsilylcyclopentadienyl (4,7-dimethylindenyl) zirconium dichloride, dimethylsilylcyclopentadienyl (3,5-dimethylphenylindenyl) zirconium dichloride, dimethylsilylbis (2-methylcyclopentadienyl) zirconium dichloride, dimethylsilylbis (2-methylindenyl) zirconium dichloride, Dimethylsilylbis(2-methylindenyl)zirconium dichloride, dimethylsilylbis(n-propylcyclopentadienyl)hafnium dichloride, dimethylsilylbis(indenyl)hafnium dichloride, diethylsilylbis(indenyl)hafnium dichloride, diphenylsilylbis(4,7-dimethylindenyl)hafnium dichloride, dimethylsilylbis(4,7-dimethylindenyl)hafnium dichloride, dimethylsilylbis(indenyl)hafnium dichloride, diphenylsilylbis(2-methylcyclopentadienyl)hafnium dichloride, ethylenebis(indenyl)hafnium dichloride, ethylenebis(2-methylindenyl)hafnium dichloride, dimethylsilylbis(2-methyl-3-butylcyclopentadienyl)hafnium dichloride, dimethylsilylbis(cyclopentadienyl)hafnium dichloride , diethylmethylenecyclopentadienyl(3,5-dimethylphenylindenyl)hafnium dichloride, diethylmethylenecyclopentadienyl(4,7-dimethylindenyl)hafnium dichloride, dimethylmethylenecyclopentadienyl(4,7-dimethylindenyl)hafnium dichloride, dimethylsilylcyclopentadienyl(4,7-dimethylindenyl)hafnium dichloride, dimethylsilylcyclopentadienyl(3,5-dimethylphenylindenyl)hafnium dichloride, dimethylsilylbis(2-methylcyclopentadienyl)hafnium dichloride, dimethylsilylbis(2-methylindenyl)hafnium dichloride and dimethylsilylcyclopentadienyl(2-methylindenyl)hafnium dichloride.

[0013] According to some embodiments of the preparation method of the present invention, preferably, the activator is alkyl aluminum and / or borate.

[0014] According to some embodiments of the preparation method of the present invention, preferably, the chemical formula of the alkyl aluminum is AlR3, wherein R is C1-C 10The alkyl group is preferably selected from at least one of trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-propylaluminum, triisobutylaluminum, tri-n-butylaluminum, triisopentylaluminum, tri-n-pentylaluminum, triisohexylaluminum, tri-n-hexylaluminum, triisoheptylaluminum, tri-n-heptylaluminum, triisooctylaluminum, tri-n-octylaluminum, triisononylaluminum, tri-n-nonylaluminum, triisodecylaluminum and tri-n-decylaluminum.

[0015] According to some embodiments of the preparation method of the present invention, preferably, the borate is selected from at least one of tetrakis(pentafluorophenyl)borate dimethylanilinium salt, tetrakis(pentafluorophenyl)borate diethylanilinium salt, tetrakis(pentafluorophenyl)borate dibutylanilinium salt, tetrakis(pentafluorophenyl)borate trimethylammonium salt, tetrakis(pentafluorophenyl)borate diethylammonium salt and tetrakis(pentafluorophenyl)borate tributylammonium salt.

[0016] In the present invention, the weight ratio of the metallocene catalyst, the activator and the α-olefin monomer can have a wide range, for example, but not limited to, the weight ratio of the metallocene catalyst, the activator and the α-olefin monomer can be 1: (10 to 1000): (100 to 1×10 5 ).

[0017] According to some embodiments of the preparation method of the present invention, preferably, the polymerization reaction further comprises using a solvent, preferably, the solvent is an alkane solvent and / or an aromatic solvent, more preferably at least one of hexane, heptane, octane, nonane, decane, cyclohexane, benzene, toluene and xylene. In the present invention, the amount of the solvent can have a wide selection range, for example, the volume ratio of the solvent to the monomer is (1 to 1000):1.

[0018] According to some embodiments of the preparation method of the present invention, preferably, the conditions of the polymerization reaction include: temperature of 20 to 200° C., pressure of 0.1 to 2 MPa, and time of 0.5 to 5 h.

[0019] Beneficial effects of the present invention:

[0020] The method of the present invention does not require the addition of an additional catalyst, and does not cause saturation and loss of the raw materials. The saturation of the product is carried out by catalytic hydrogenation of the polymerization catalyst metallocene compound itself. The method has high economic benefits and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a process flow chart of the method for preparing saturated metallocene poly-α-olefin according to Example 1 of the present invention. DETAILED DESCRIPTION

[0022] In order to make the present invention more easily understood, the present invention will be described in detail below in conjunction with embodiments. These embodiments are only for illustration and are not intended to limit the application scope of the present invention.

[0023] [Example 1]

[0024] Process flow chart Figure 1 As shown. 100g of 1-octene and 200mL of toluene were added to a 500mL flask filled with nitrogen, and heated at 100°C for 30 minutes. 50mL of metallocene catalyst solution (3μmol of dimethylsilylbisindenyl zirconium dichloride, 50mg of dimethylanilinium tetrakis(pentafluorophenyl)borate, and 35mg of triethylaluminum) was added. After reacting for 1 hour, the unreacted 1-octene was removed by vacuum distillation. 0.1MPa of hydrogen was added at 100°C, and the reaction was continued for 2 hours. Finally, 92g of saturated metallocene polyalphaolefin product was obtained. The yield was calculated to be 92%.

[0025] The performance of the saturated metallocene poly-alpha-olefin product was tested, and the kinematic viscosity at 100°C was 20 cSt, the viscosity index was 191, the weight average molecular weight was 2843, and the bromine index was 80 mg / 100 g.

[0026] [Example 2]

[0027] Add 100g of 1-octene and 200mL of toluene to a 500mL flask filled with nitrogen, heat at 100°C for 30 minutes, and add 50mL of metallocene catalyst solution (3μmol of dimethylsilylbisindenyl zirconium dichloride, 50mg of dimethylanilinium tetrakis(pentafluorophenyl)borate, 35mg of triethylaluminum). After reacting for 1 hour, remove the unreacted 1-octene by vacuum distillation. Add 0.5MPa of hydrogen at 100°C, continue the reaction for 2 hours, and finally obtain 90g of saturated metallocene polyalphaolefin product, with a yield of 90% calculated.

[0028] The performance of the saturated metallocene poly-alpha-olefin product was tested, and the kinematic viscosity at 100°C was 19 cSt, the viscosity index was 191, the weight average molecular weight was 2780, and the bromine index was 50 mg / 100 g.

[0029] [Example 3]

[0030] Add 100g of 1-octene and 200mL of toluene to a 500mL flask filled with nitrogen, heat at 100°C for 30 minutes, and add 50mL of metallocene catalyst solution (3μmol of dimethylsilylbisindenyl zirconium dichloride, 50mg of dimethylanilinium tetrakis(pentafluorophenyl)borate, and 35mg of triethylaluminum). After reacting for 1 hour, remove the unreacted 1-octene by vacuum distillation. Add 1MPa of hydrogen at 100°C and continue the reaction for 2 hours to finally obtain 92g of saturated metallocene polyalphaolefin product, with a calculated yield of 92%.

[0031] The performance of the saturated metallocene polyalphaolefin product was tested, and the kinematic viscosity at 100°C was 22 cSt, the viscosity index was 191, the weight average molecular weight was 2875, and the bromine index was 20 mg / 100 g.

[0032] [Example 4]

[0033] Add 100g of 1-octene and 200mL of toluene to a 500mL flask filled with nitrogen, heat at 100°C for 30 minutes, and add 50mL of metallocene catalyst solution (3μmol of dimethylsilylbisindenyl zirconium dichloride, 50mg of dimethylanilinium tetrakis(pentafluorophenyl)borate, 35mg of triethylaluminum). After reacting for 1 hour, remove the unreacted 1-octene by vacuum distillation. Add 1MPa of hydrogen at 100°C, continue the reaction for 3 hours, and finally obtain 93g of saturated metallocene polyalphaolefin product, with a calculated yield of 93%.

[0034] The performance of the saturated metallocene poly-alpha-olefin product was tested, and the kinematic viscosity at 100°C was 20 cSt, the viscosity index was 191, the weight average molecular weight was 2818, and the bromine index was 9 mg / 100 g.

[0035] [Example 5]

[0036] Add 100g of 1-octene and 200mL of toluene to a 500mL flask filled with nitrogen, heat at 100°C for 30 minutes, and add 50mL of metallocene catalyst solution (3μmol of dimethylsilylbisindenyl zirconium dichloride, 50mg of dimethylanilinium tetrakis(pentafluorophenyl)borate, and 35mg of triethylaluminum). After reacting for 1 hour, remove the unreacted 1-octene by vacuum distillation. Add 2MPa of hydrogen at 100°C and continue the reaction for 2 hours to finally obtain 91g of saturated metallocene polyalphaolefin product, with a calculated yield of 91%.

[0037] The performance of the saturated metallocene polyalphaolefin product was tested, and the kinematic viscosity at 100°C was 20 cSt, the viscosity index was 190, the weight average molecular weight was 2802, and the bromine index was 5 mg / 100 g.

[0038] [Example 6]

[0039] 100 g of 1-octene and 200 mL of toluene were added to a 500 mL flask filled with nitrogen, and heated at 100°C for 30 minutes. 50 mL of metallocene catalyst solution (3 μmol of dimethylsilylbisindenyl zirconium dichloride, 50 mg of dimethylanilinium tetrakis(pentafluorophenyl)borate, and 35 mg of triethylaluminum) was added. After reacting for 1 hour, unreacted 1-octene was removed by vacuum distillation. 0.1 MPa of hydrogen was added at 100°C, and the reaction was continued for 6 hours. Finally, 92 g of saturated metallocene polyalphaolefin product was obtained. The yield was calculated to be 92%.

[0040] The performance of the saturated metallocene poly-alpha-olefin product was tested, and the kinematic viscosity at 100°C was 21 cSt, the viscosity index was 190, the weight average molecular weight was 2836, and the bromine index was 18 mg / 100 g.

[0041] [Example 7]

[0042] Add 100g of 1-octene and 200mL of toluene to a 500mL flask filled with nitrogen, heat at 50°C for 30 minutes, and add 50mL of metallocene catalyst solution (3μmol of dimethylsilylbisindenyl zirconium dichloride, 50mg of dimethylanilinium tetrakis(pentafluorophenyl)borate, and 35mg of triethylaluminum). After reacting for 1 hour, remove the unreacted 1-octene by vacuum distillation. Add 0.1MPa of hydrogen at 50°C, continue the reaction for 2 hours, and finally obtain 95g of saturated metallocene polyalphaolefin product, with a yield of 95% after calculation.

[0043] The performance test of the saturated metallocene poly-alpha-olefin product showed that the kinematic viscosity at 100°C was 160 cSt, the viscosity index was 218, the weight average molecular weight was 7407, and the bromine index was 107 mg / 100 g.

[0044] [Example 8]

[0045] Add 100g of 1-octene and 200mL of toluene to a 500mL flask filled with nitrogen, heat at 150°C for 30 minutes, and add 50mL of metallocene catalyst solution (3μmol of dimethylsilylbisindenyl zirconium dichloride, 50mg of dimethylanilinium tetrakis(pentafluorophenyl)borate, 35mg of triethylaluminum). After reacting for 1 hour, remove the unreacted 1-octene by vacuum distillation. Add 0.1MPa of hydrogen at 150°C, continue the reaction for 2 hours, and finally obtain 86g of saturated metallocene polyalphaolefin product, with a calculated yield of 86%.

[0046] The performance test of the saturated metallocene poly-alpha-olefin product showed that the kinematic viscosity at 100°C was 11 cSt, the viscosity index was 156, the weight average molecular weight was 1855, and the bromine index was 3 mg / 100 g.

[0047] [Example 9]

[0048] The method of Example 1 was followed, except that 1-octene was replaced by 1-hexadecene. Finally, 93 g of saturated metallocene poly-α-olefin product was obtained, and the yield was calculated to be 93%.

[0049] The performance test of the saturated metallocene poly-alpha-olefin product showed that the kinematic viscosity at 100°C was 104 cSt, the viscosity index was 200, the weight average molecular weight was 5658, and the bromine index was 87 mg / 100 g.

[0050] [Example 10]

[0051] The method of Example 1 was followed, except that dimethylsilylbisindenylzirconium dichloride was replaced by dimethylsilylbis-n-propylcyclopentadienylzirconium dichloride. Finally, 85 g of saturated metallocene poly-α-olefin product was obtained, and the yield was calculated to be 85%.

[0052] The performance test of the saturated metallocene polyalphaolefin product showed that the kinematic viscosity at 100°C was 17 cSt, the viscosity index was 160, the weight average molecular weight was 2537, and the bromine index was 60 mg / 100 g.

[0053] [Example 11]

[0054] The method of Example 1 was followed, except that dimethylsilylbisindenylzirconium dichloride was replaced by dimethylsilylbis-n-propylcyclopentadienylhafnium dichloride. Finally, 80 g of saturated metallocene poly-α-olefin product was obtained, and the yield was calculated to be 80%.

[0055] The performance of the saturated metallocene polyalphaolefin product was tested, and the kinematic viscosity at 100°C was 15 cSt, the viscosity index was 170, the weight average molecular weight was 2410, and the bromine index was 62 mg / 100 g.

[0056] [Example 12]

[0057] The method of Example 1 was followed, except that tetrakis(pentafluorophenyl)borate dimethylanilinium salt was replaced by tetrakis(pentafluorophenyl)borate trimethylammonium salt. Finally, 93 g of saturated metallocene poly-α-olefin product was obtained, and the yield was calculated to be 93%.

[0058] The performance of the saturated metallocene poly-alpha-olefin product was tested, and the kinematic viscosity at 100°C was 20 cSt, the viscosity index was 190, the weight average molecular weight was 2752, and the bromine index was 76 mg / 100 g.

[0059] [Example 13]

[0060] The method of Example 1 was followed, except that triethylaluminum was replaced by tri-n-butylaluminum. Finally, 95 g of saturated metallocene poly-α-olefin product was obtained, and the yield was calculated to be 95%.

[0061] The performance test of the saturated metallocene poly-alpha-olefin product showed that the kinematic viscosity at 100°C was 20 cSt, the viscosity index was 190, the weight average molecular weight was 2689, and the bromine index was 81 mg / 100 g.

[0062] [Comparative Example 1]

[0063] The method of Example 1 is the same, except that the vacuum distillation is not performed, that is, the unreacted monomers are not removed. The details are as follows:

[0064] 100 g of 1-octene and 200 mL of toluene were added to a 500 mL flask filled with nitrogen, and heated at 100°C for 30 minutes. 50 mL of metallocene catalyst solution (3 μmol of dimethylsilylbisindenyl zirconium dichloride, 50 mg of dimethylanilinium tetrakis(pentafluorophenyl)borate, and 35 mg of triethylaluminum) was added. After reacting for 1 hour, 0.1 MPa of hydrogen was added, and the reaction was continued for 2 hours. Finally, 90 g of saturated metallocene polyalphaolefin product was obtained. The yield was calculated to be 90%.

[0065] The performance of the saturated metallocene polyalphaolefin product was tested, and the kinematic viscosity at 100°C was 20 cSt, the viscosity index was 191, the weight average molecular weight was 2905, and the bromine index was 120 mg / 100 g.

[0066] [Comparative Example 2]

[0067] The method of Example 1 is followed, except that hydrogen is added during the reaction, as follows:

[0068] 100 g of 1-octene and 200 mL of toluene were added to a 500 mL flask filled with nitrogen, and heated at 100° C. for 30 minutes. 50 mL of a metallocene catalyst solution (3 μmol of dimethylsilylbisindenylzirconium dichloride, 50 mg of dimethylanilinium tetrakis(pentafluorophenyl)borate, and 35 mg of triethylaluminum) was added. 0.1 MPa of hydrogen was added, and the reaction was continued for 3 hours. Finally, 60 g of a saturated metallocene polyα-olefin product was obtained. The yield was calculated to be 60%.

[0069] The performance of the saturated metallocene polyalphaolefin product was tested, and the kinematic viscosity at 100°C was 9 cSt, the viscosity index was 150, the weight average molecular weight was 1692, and the bromine index was 50 mg / 100 g.

[0070] It can be seen from Examples 1-13 and Comparative Examples 1-2 that the method of the present invention does not require the addition of additional catalysts, thus saving equipment investment and raw material costs, and does not cause saturation and loss of raw materials. The prepared saturated metallocene poly-α-olefin has excellent performance.

[0071] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this field, under the technical enlightenment provided by the present invention, as common knowledge in the field, other equivalent variations and improvements can also be made, which should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a saturated metallocene poly-α-olefin, comprising: In the presence of a metallocene catalyst and an activator, α-olefin monomers are polymerized, unreacted monomers are removed, and hydrogen is added to carry out a hydrogenation reaction; The conditions of the hydrogenation reaction include: temperature of 50-100°C, time of 0.5-12h, and hydrogen pressure of 0.1-2MPa; the conditions of the polymerization reaction include: temperature of 50-100°C, pressure of 0.1-2MPa, and time of 0.5-5h.

2. The preparation method according to claim 1, characterized in that: The method for removing unreacted monomers is reduced pressure distillation.

3. The preparation method according to claim 1 or 2, characterized in that: The α-olefin is selected from one or more of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene and 1-eicosene.

4. The preparation method according to claim 3, characterized in that: The α-olefin is selected from one or more of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene and 1-tetradecene.

5. The preparation method according to claim 1 or 2, characterized in that: The metallocene catalyst is selected from dimethylsilylbis-n-propylcyclopentadienyl zirconium dichloride, dimethylsilylbis-indenyl zirconium dichloride, diethylsilylbis-indenyl zirconium dichloride, diphenylsilylbis(4,7-dimethylindenyl) zirconium dichloride, dimethylsilylbis(4,7-dimethylindenyl) zirconium dichloride, dimethylsilylbis-indenyl zirconium dichloride, diphenylsilylbis(2-methylcyclopentadienyl) zirconium dichloride, ethylenebis-indenyl zirconium dichloride, ethylenebis-(2-methylindenyl) zirconium dichloride, dimethylsilylbis(2-methyl-3-butylcyclopentadienyl) zirconium dichloride, dimethylsilylbis-cyclopentadienyl zirconium dichloride Zirconium chloride, diethylmethylenecyclopentadienyl (3,5-dimethylphenylindenyl) zirconium dichloride, diethylmethylenecyclopentadienyl (4,7-dimethylindenyl) zirconium dichloride, dimethylmethylenecyclopentadienyl (4,7-dimethylindenyl) zirconium dichloride, dimethylsilylcyclopentadienyl (4,7-dimethylindenyl) zirconium dichloride, dimethylsilylcyclopentadienyl (3,5-dimethylphenylindenyl) zirconium dichloride, dimethylsilylbis (2-methylcyclopentadienyl) zirconium dichloride, dimethylsilylbis (2-methylindenyl) zirconium dichloride Zirconium, dimethylsilylbis-n-propylcyclopentadienyl hafnium dichloride, dimethylsilylbis-indenyl hafnium dichloride, diethylsilylbis-indenyl hafnium dichloride, diphenylsilylbis(4,7-dimethylindenyl) hafnium dichloride, dimethylsilylbis(4,7-dimethylindenyl) hafnium dichloride, dimethylsilylbis-indenyl hafnium dichloride, diphenylsilylbis(2-methylcyclopentadienyl) hafnium dichloride, ethylenebis-indenyl hafnium dichloride, ethylenebis(2-methylindenyl) hafnium dichloride, dimethylsilylbis(2-methyl-3-butylcyclopentadienyl) hafnium dichloride, dimethylsilylbis-cyclopentadienyl hafnium dichloride, diethylmethylene at least one of dimethylcyclopentadienyl (3,5-dimethylphenylindenyl) hafnium dichloride, diethylmethylenecyclopentadienyl (4,7-dimethylindenyl) hafnium dichloride, dimethylmethylenecyclopentadienyl (4,7-dimethylindenyl) hafnium dichloride, dimethylsilylcyclopentadienyl (4,7-dimethylindenyl) hafnium dichloride, dimethylsilylcyclopentadienyl (3,5-dimethylphenylindenyl) hafnium dichloride, dimethylsilylbis (2-methylcyclopentadienyl) hafnium dichloride, dimethylsilylbis (2-methylindenyl) hafnium dichloride and dimethylsilylcyclopentadienyl (2-methylindenyl) hafnium dichloride.

6. The preparation method according to claim 1 or 2, characterized in that: The activator is alkyl aluminum and / or borate.

7. The preparation method according to claim 6, characterized in that: The chemical formula of the alkyl aluminum is AlR3, wherein R is C1-C 10 of alkyl.

8. The preparation method according to claim 7, characterized in that: The alkylaluminum is selected from at least one of trimethylaluminum, triethylaluminum, triisopropylaluminum, tri-n-propylaluminum, triisobutylaluminum, tri-n-butylaluminum, triisopentylaluminum, tri-n-pentylaluminum, triisohexylaluminum, tri-n-hexylaluminum, triisoheptylaluminum, tri-n-heptylaluminum, triisooctylaluminum, tri-n-octylaluminum, triisononylaluminum, tri-n-nonylaluminum, triisodecylaluminum and tri-n-decylaluminum.

9. The preparation method according to claim 6, characterized in that: The borate is at least one selected from tetrakis(pentafluorophenyl)borate dimethylanilinium salt, tetrakis(pentafluorophenyl)borate diethylanilinium salt, tetrakis(pentafluorophenyl)borate dibutylanilinium salt, tetrakis(pentafluorophenyl)borate trimethylammonium salt, tetrakis(pentafluorophenyl)borate diethylammonium salt and tetrakis(pentafluorophenyl)borate tributylammonium salt.

10. The preparation method according to claim 1, characterized in that: The polymerization reaction further comprises using a solvent.

11. The preparation method according to claim 10, characterized in that: The solvent is an alkane solvent and / or an aromatic hydrocarbon solvent.

12. The preparation method according to claim 11, characterized in that: The solvent is selected from at least one of hexane, heptane, octane, nonane, decane, cyclohexane, benzene, toluene and xylene.

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