A metallocene catalyst composition and its preparation method and application

Abstract

The present invention provides a metallocene catalyst composition and a preparation method and application thereof, belonging to the field of olefin polymerization catalysts. The present invention can obtain a metallocene catalyst composition by compounding a main catalyst with a stabilizer shown in Formula V and a carrier, and a polymer with good morphology, high bulk density and narrow molecular weight distribution can be obtained by using the metallocene catalyst composition. Among them, the stabilizer shown in Formula V can not only act on part of the active centers of the main catalyst to inhibit the initial activity of the main catalyst, and reduce the generation of static electricity and fine powder when the metallocene catalyst composition is used for olefin polymerization reaction; it can also minimize the inhibition of catalytic activity while ensuring that the metallocene catalyst composition stably catalyzes the olefin polymerization reaction.

Description

Technical Field

[0001] The invention relates to an olefin polymerization catalyst, and in particular to a metallocene catalyst composition and a preparation method and application thereof. Background Art

[0002] Metallocene catalysts refer to catalysts that use a complex of a Group IVB transition metal (such as Ti, Zr, Hf) as the main catalyst and an alkylaluminoxane (such as methylaluminoxane MAO) or an organic boron compound (such as B(C 6 F 5 ) 3 ) as a co-catalyst. Metallocene catalysts are another major breakthrough after Ziegler Natta catalysts. Since Professor Kaminsky of Hamburg University in Germany first discovered in the early 1980s that the metallocene / MAO catalyst system has high activity for olefin polymerization, this catalyst system has been a hot topic of research.

[0003] However, in the gas phase polymerization and slurry polymerization of olefins, the friction between solid particles, the flow of liquids, impurities in the reaction system, and the breakage of catalysts will generate static electricity, and the charged particles containing active centers will be adsorbed or adhered to the wall of the reaction device to continue the reaction, which will produce local "hot spots" and cause the reaction products to melt and agglomerate, which will not only increase the lumps in the product and affect the product quality, but also may affect the long-term stable operation of the reaction device, resulting in an increase in the operating cost of the reaction device. In addition, the direct use of metallocene catalysts for olefin polymerization reactions is also prone to serious sticking of the reactants to the reactor, and the morphology of the prepared reaction products is generally poor, making post-processing difficult.

[0004] In view of the above problems, researchers have made many attempts, for example, introducing antistatic agents and carriers into metallocene catalysts to form metallocene catalyst compositions. Patent application number EP97303811 "Process for controlling static in polymerizations utilizing metallocene catalysts" discloses a method for controlling static when catalyzing ethylene polymerization in a gas phase fluidized bed reactor using a metallocene supported catalyst, using amines containing hydroxyl groups as antistatic agents, wherein the main catalyst is a metallocene compound bis(n-butylcyclopentadienyl)zirconium dichloride or indenyl tri(diethylamino)zirconium, and the cocatalyst is MAO or modified MAO; when no antistatic agent is added, the static voltage is -1500 V to -3000 V, and the static voltage can be controlled by adding 10 mg / kg of the antistatic agent ATMER-163 whose main component is octadecyl bis(hydroxyethyl)amine, but the catalytic activity is still affected to a certain extent; when the antistatic agent ATMER-104 whose main component is sorbitan tristearate or the quaternary ammonium salt antistatic agent ATMER-190 is used, the amount of the antistatic agent to be added needs to be 2000 mg / kg or 2000 mg / kg, respectively. When the static electricity was controlled at 370 mg / kg and the catalyst activity decreased by 80% and 50% respectively.

[0005] It can be seen that after introducing antistatic agents and carriers into metallocene catalysts, the antistatic agents easily reduce the activity of the catalyst, which is not conducive to the reaction. Therefore, how to find a metallocene catalyst composition that can reduce the sticking of reactants to the kettle, maintain the good shape of the reaction products, and at the same time can not only improve the catalytic activity but also effectively control static electricity needs to be solved urgently. Summary of the invention

[0006] The invention provides a metallocene catalyst composition, which has high fluidity and bulk density, can play a good antistatic role when applied to olefin polymerization reaction, and the obtained polymer has good morphology, high bulk density, narrow molecular weight distribution and is not easy to agglomerate.

[0007] The present invention provides a method for preparing the above-mentioned metallocene catalyst composition, which can simply and quickly obtain the metallocene catalyst composition by limiting the sequence of raw materials and the reaction temperature and time to meet a certain range.

[0008] The present invention also provides an application of the metallocene catalyst composition or the metallocene catalyst composition prepared by the preparation method in olefin polymerization.

[0009] The present invention provides a metallocene catalyst composition, comprising a carrier and a main catalyst and a stabilizer loaded on the carrier;

[0010] The main catalyst has the structure shown in Formula I:

[0011] Formula I;

[0012] In Formula I, M is selected from one of the transition metal elements of Groups IIIB, IVB, VB, and VIB in the Periodic Table; X is selected from halogen, -R 1 、-OR 2 、-SR 3 、-OCOR 4 、-N(R 5 ) 2 、-P(R 6 ) 2 or-OSO 2 CF 3 One of; Q is selected from -C(R 7 ) 2 -、-Si(R 8 ) 2 -、-Ge(R 9 ) 2 -、-N(R 10 ) 2 -、-P(R 11 ) 2 -or-B(R 12 ) 2 - one of;

[0013] Among them, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 are each independently selected from hydrogen, substituted or unsubstituted C 1 -C 30 Alkyl, substituted or unsubstituted C 3 -C 30 Cycloalkyl, substituted or unsubstituted C 6 -C 30 One of the aromatic groups;

[0014] A and Z are each independently selected from one of the π-ligands shown in formula II, formula III, and formula IV:

[0015] Formula II; Formula III; Formula IV;

[0016] n is an integer from 1 to 4;

[0017] R 13 , R 13 '、R 15 , R 19 Each is independently selected from one of hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl, benzyl, 2-furyl, and 2-thienyl;

[0018] R 14 , R 14 '、R 16 , R 16 ' are each independently selected from hydrogen, substituted or unsubstituted C 1 -C 40 Alkyl, substituted or unsubstituted C 3 -C 40 Cycloalkyl, substituted or unsubstituted C 6 -C 40 One of the aromatic groups;

[0019] R 17 , R 17 '、R 20 , R 21 , R 22 , R 23 are each independently selected from hydrogen, substituted or unsubstituted C 1 -C 40 One of the alkyl groups;

[0020] R 18 , R 24 Each independently selected from one of hydrogen and fluorine;

[0021] R 25 , R 26 Each independently selected from hydrogen, fluorine, chlorine, bromine, -OR 27 、-SR 28 、-OCOR 29 、-N(R 30 ) 2 、-P(R 31 ) 2 One of;

[0022] Among them, R 27 , R 28 , R 29 , R 30 , R 31 are each independently selected from substituted or unsubstituted C 1 -C 40 Alkyl, substituted or unsubstituted C 3 -C40 Cycloalkyl, substituted or unsubstituted C 6 -C 40 One of the aromatic groups;

[0023] The stabilizer has the structure shown in Formula V:

[0024] Formula V.

[0025] The metallocene catalyst composition as described above, wherein the molar ratio of the main catalyst to the stabilizer is 1:(0.1-1).

[0026] The metallocene catalyst composition as described above, wherein the carrier comprises at least one of silica gel, composite silica gel and clay.

[0027] The metallocene catalyst composition as described above, wherein the silica gel comprises Lewis acid-modified silica gel;

[0028] Lewis acids include polymethylaluminoxane, modified polymethylaluminoxane or organoboron reagents;

[0029] The modified anion in the modified polymethylaluminoxane is selected from [Al(C 6 H 5 ) 4 ] - 、[(CH 3 )Al(C 6 F 5 ) 3 ] - 、[Al(C 6 F 5 ) 4 ] - 、[Al(2,6-(CH 3 ) 2 -C 6 H 3 ) 4 ] - 、[Al(2,4,6-(CH 3 ) 3 -C 6 H 2 ) 4 ] - 、[Al(2,3,5,6-(CH 3 ) 4 -C 6 H) 4 ] - 、[Al(3,5-(CH 3 ) 2 -C 6 H 3 ) 4 ]- 、[Al(3,4,5-(CH 3 ) 3 -C 6 H 2 ) 4 ] - 、[Al(2,6-(CH 3 ) 2 -C 6 F 3 ) 4 ] - 、[Al(2,4,6-(CH 3 ) 3 -C 6 F 2 ) 4 ] - 、[Al(2,3,5,6-(CH 3 ) 4 -C 6 F) 4 ] - 、[Al(3,5-(CH 3 ) 2 -C 6 F 3 ) 4 ] - 、[Al(3,4,5-(CH 3 ) 3 -C 6 F 2 ) 4 ] - 、[Al(2,6-(CF 3 ) 2 -C 6 H 3 ) 4 ] - 、[Al(2,4,6-(CF 3 ) 3 -C 6 H 2 ) 4 ] - 、[Al(2,3,5,6-(CF 3 ) 4 -C 6 H) 4 ] - At least one of;

[0030] The anion in the organoboron reagent is selected from [B(C 6 H 5 ) 4 ] - 、[(CH 3 )B(C 6F 5 ) 3 ] - 、[B(C 6 F 5 ) 4 ] - 、[B(2,6-(CH 3 ) 2 -C 6 H 3 ) 4 ] - 、[B(2,4,6-(CH 3 ) 3 -C 6 H 2 ) 4 ] - 、[B(2,3,5,6-(CH 3 ) 4 -C 6 H) 4 ] - 、[B(2,6-(CF 3 ) 2 -C 6 H 3 ) 4 ] - 、[B(2,4,6-(CF 3 ) 3 -C 6 H 2 ) 4 ] - 、[B(2,3,5,6-(CF 3 ) 4 -C 6 H) 4 ] - 、[B(3,5-(CH 3 ) 2 -C 6 H 3 ) 4 ] - 、[B(3,4,5-(CH 3 ) 3 -C 6 H 2 ) 4 ] - 、[B(3,5-(CF 3 ) 2 -C 6 H 3 ) 4 ] - 、[B(3,4,5-(CF 3 ) 3 -C 6 H2 ) 4 ] - , [B(2,6-(CF 3 ) 2 -C 6 F 3 ) 4 ] - , [B(2,4,6-(CF 3 ) 3 -C 6 F 2 ) 4 ] - , [B(2,3,5,6-(CF 3 ) 4 -C 6 F) 4 ] - , [B(3,5-(CF 3 ) 2 -C 6 F 3 ) 4 ] - , [B(3,4,5-(CF 3 ) 3 -C 6 F 2 ) 4 ] - At least one of .

[0031] In the metallocene catalyst composition as described above, the Lewis acid-modified silica gel is prepared by reacting silica gel and Lewis acid at 40° C.-80° C. for 5-8 h.

[0032] The metallocene catalyst composition as described above, wherein the metallocene catalyst composition further comprises a co-catalyst;

[0033] The co-catalyst includes at least one of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisobutylaluminum, trihexylaluminum, tri-n-butylaluminum, triisopropylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldibenzylaluminum, ethyldi-p-tolylaluminum and diethylbenzylaluminum.

[0034] The present invention provides a method for preparing the above-mentioned metallocene catalyst composition, comprising the following steps:

[0035] The main catalyst and the carrier are subjected to a first reaction to obtain a first reactant;

[0036] adding a stabilizer to the first reactant to carry out a second reaction to obtain a metallocene catalyst composition;

[0037] The temperature of the first reaction is 40-100°C and the time is 180-480 min;

[0038] The temperature of the second reaction is 40-80°C and the time is 50-480 min.

[0039] The preparation method as described above, wherein the preparation method of the main catalyst comprises the following steps:

[0040] The compound represented by formula a is reacted with the compound represented by formula b to obtain the main catalyst represented by formula I;

[0041]

[0042] In formula a, Q, A, and Z are defined as above, and LG is selected from hydrogen, an alkali metal element, or an organic free radical comprising one of Si, Ge, Sn, Pd, Zn, Ba, Mg, and Ca;

[0043] In formula b, M, X, and n are defined as above, T is selected from a monodentate or bidentate neutral ligand, and k is an integer between 0 and 3.

[0044] The preparation method as described above, wherein the stabilizer represented by formula V is prepared by reacting melem and acetaldehyde;

[0045] The reaction temperature is 60°C-90°C, the reaction time is 1-10 h, and the pH value is 8-9.

[0046] The present invention also provides an application of the metallocene catalyst composition or the metallocene catalyst composition prepared by the preparation method in olefin polymerization.

[0047] The invention provides a metallocene catalyst composition, comprising a carrier, a main catalyst and a stabilizer loaded on the carrier. The metallocene catalyst composition is obtained by compounding the main catalyst, the stabilizer and the carrier. The metallocene catalyst composition has high fluidity and bulk density, so it is convenient for transportation and catalyst feeding in industrial production processes. When applied to olefin polymerization reaction, it can play a good antistatic role, and the obtained polymer has good morphology, high bulk density and narrow molecular weight distribution, so it is not easy to agglomerate. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a molecular weight distribution curve of polyethylene powder 1 in test example 1;

[0049] Figure 2 is a molecular weight distribution curve of polyethylene powder 2 in test example 1;

[0050] Figure 3 is a molecular weight distribution curve of polyethylene powder 3 in test example 1;

[0051] Figure 4 This is a diagram showing the phenomenon of the polyethylene powder 20 sticking to the reactor after the slurry polymerization reaction in Test Example 1;

[0052] Figure 5 This is a diagram showing the phenomenon of the polyethylene powder 21 sticking to the reactor after the slurry polymerization reaction in Test Example 1;

[0053] Figure 6 This is a diagram showing the phenomenon that the reactor does not stick after the slurry polymerization reaction of the polyethylene powder 2 in Test Example 1. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below. The specific implementation methods listed below are only for describing the principles and features of the present invention. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0055] The first aspect of the present invention provides a metallocene catalyst composition, comprising a carrier and a main catalyst and a stabilizer supported on the carrier;

[0056] The main catalyst has the structure shown in Formula I:

[0057] Formula I;

[0058] In Formula I, M is selected from one of the transition metal elements of Groups IIIB, IVB, VB, and VIB in the Periodic Table; X is selected from halogen, -R 1 、-OR 2 、-SR 3 、-OCOR 4 、-N(R 5 ) 2 、-P(R 6 ) 2 or-OSO 2 CF 3 One of; Q is selected from -C(R 7 ) 2 -、-Si(R 8 ) 2 -、-Ge(R 9 ) 2 -、-N(R 10 ) 2 -、-P(R 11 ) 2 -or-B(R 12 ) 2 - one of;

[0059] Among them, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 are each independently selected from hydrogen, substituted or unsubstituted C 1 -C 30 Alkyl, substituted or unsubstituted C 3 -C 30 Cycloalkyl, substituted or unsubstituted C 6 -C 30 One of the aromatic groups;

[0060] n is an integer from 1 to 4;

[0061] A and Z are each independently selected from one of the π-ligands shown in formula II, formula III, and formula IV:

[0062] Formula II; Formula III; Formula IV;

[0063] R 13 , R 13 '、R 15 , R 19 Each is independently selected from one of hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl, benzyl, 2-furyl, and 2-thienyl;

[0064] R 14 , R 14 '、R 16 , R 16 ' are each independently selected from hydrogen, substituted or unsubstituted C 1 -C 40 Alkyl, substituted or unsubstituted C 3 -C 40 Cycloalkyl, substituted or unsubstituted C 6 -C 40 One of the aromatic groups;

[0065] R 17 , R 17 '、R 20 , R 21 , R 22 , R 23are each independently selected from hydrogen, substituted or unsubstituted C 1 -C 40 One of the alkyl groups;

[0066] R 18 , R 24 Each independently selected from one of hydrogen and fluorine;

[0067] R 25 , R 26 Each independently selected from hydrogen, fluorine, chlorine, bromine, -OR 27 、-SR 28 、-OCOR 29 、-N(R 30 ) 2 、-P(R 31 ) 2 One of;

[0068] Among them, R 27 , R 28 , R 29 , R 30 , R 31 are each independently selected from substituted or unsubstituted C 1 -C 40 Alkyl, substituted or unsubstituted C 3 -C 40 Cycloalkyl, substituted or unsubstituted C 6 -C 40 One of the aromatic groups;

[0069] The stabilizer has the structure shown in Formula V:

[0070] Formula V.

[0071] In the present invention, the main catalyst has a structure shown in Formula I:

[0072] Formula I;

[0073] In Formula I, M is selected from one of the transition metal elements of Groups IIIB, IVB, VB, and VIB in the periodic table; further, M can be selected from one of the transition metal elements of Groups IIIB and IVB in the periodic table; further, M can be selected from one of Ti, Zr, and Hf in Group IVB in the periodic table; X is selected from halogen, -R 1 、-OR 2 、-SR 3 、-OCOR 4 、-N(R 5 ) 2 、-P(R 6 )2 or-OSO 2 CF 3 It can be understood that X is the same or different from each other; Q is a divalent free radical selected from -C(R 7 ) 2 -、-Si(R 8 ) 2 -、-Ge(R 9 ) 2 -、-N(R 10 ) 2 -、-P(R 11 ) 2 -or-B(R 12 ) 2 - one of;

[0074] Among them, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 are each independently selected from hydrogen, substituted or unsubstituted C 1 -C 30 Alkyl, substituted or unsubstituted C 3 -C 30 Cycloalkyl, substituted or unsubstituted C 6 -C 30 One of the aromatic groups;

[0075] Specifically, substituted or unsubstituted C 1 -C 30 The alkyl group can be C 1 -C 30 A straight-chain or branched alkyl group, a saturated or unsaturated alkyl group, a halogenated or non-halogenated alkyl group, an alkyl group optionally containing heteroatoms of elements from Groups 13 to 17 of the Periodic Table, or a C 7 -C 30 Aryl substituted alkyl; for example, C 1 -C 30 Saturated alkyl and saturated halogenated alkyl include, but are not limited to, methyl, trifluoromethyl, ethyl, 1,1,1-trifluoroethyl, perfluoroethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, n-heptyl, n-octyl, n-dodecyl, n-octadecyl, trimethylsilyl, triethylsilyl, triphenylsilyl, etc.; C 1 -C 30Unsaturated alkyl groups include, but are not limited to, vinyl, propenyl, allyl, etc.;

[0076] Substituted or unsubstituted C 3 -C 30 The cycloalkyl group includes, but is not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, 1-adamantane, etc.;

[0077] Substituted or unsubstituted C 6 -C 30 Aryl includes, but is not limited to, phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl, 9-phenanthrenyl, etc.; wherein the substituted C 6 -C 30 The substituents in the aryl group may be C 1 -C 6 alkyl and / or halogen, such as 2-methylphenyl, 2,6-dimethylphenyl, 2-fluoro-3-methylphenyl, 2-fluoro-4-methylphenyl, 2,6-difluoro-3-methylphenyl, 2,6-difluoro-4-methylphenyl, 2-chloro-3-methylphenyl, 2-chloro-4-methylphenyl, 2,6-dichloro-3-methylphenyl, 2,6-dichloro-4-methylphenyl, 2-ethylphenyl, 2,6-diethylphenyl, 2-isopropylphenyl, etc.;

[0078] Furthermore, R 7 , R 8 , R 9 , R 10 , R 11 , R 12 Each of them can be independently selected from one of methyl, ethyl, isopropyl, trimethylsilyl, phenyl and benzyl;

[0079] n is an integer of 1-4, and it is understood that n can be any value of 1, 2, 3, and 4. In addition, the value of n multiplied by the charge number of X can be equal to the charge number of M minus the value of two.

[0080] In Formula I, A and Z are each independently selected from one of the π-ligands shown in Formula II, Formula III, and Formula IV:

[0081] Formula II; Formula III; Formula IV;

[0082] It is understood that in Formula II, Formula III, and Formula IV, the symbol “ "Whether connected to a chemical bond, an atom or a free radical, it means that this site can form a chemical single bond with the same chemical bond, atom or free radical, and all the symbols " ” has the same meaning.

[0083] Among them, R 13 , R 13 '、R 15 , R 19 Each is independently selected from one of hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl, benzyl, 2-furyl, and 2-thienyl;

[0084] R 14 , R 14 '、R 16 , R 16 ' are each independently selected from hydrogen, substituted or unsubstituted C 1 -C 40 Alkyl, substituted or unsubstituted C 3 -C 40 Cycloalkyl, substituted or unsubstituted C 6 -C 40 One of the aromatic groups;

[0085] Specifically, substituted or unsubstituted C 1 -C 40 The alkyl group can be C 1 -C 40 A straight-chain or branched alkyl group, a saturated or unsaturated alkyl group, a halogenated or non-halogenated alkyl group, an alkyl group optionally containing heteroatoms of elements from Groups 13 to 17 of the Periodic Table, or a C 7 -C 40 Aryl substituted alkyl; for example, C 1 -C 40 Saturated and halogenated alkyl groups include, but are not limited to, methyl, trifluoromethyl, ethyl, 1,1,1-trifluoroethyl, perfluoroethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, n-heptyl, n-octyl, n-dodecyl, n-octadecyl, trimethylsilyl, triethylsilyl, triphenylsilyl, etc.; C 1 -C 40 Unsaturated alkyl groups include, but are not limited to, vinyl, propenyl, allyl, etc.;

[0086] Substituted or unsubstituted C 3 -C 40 The cycloalkyl group includes, but is not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, 1-adamantane, etc.;

[0087] Substituted or unsubstituted C 6 -C 40Aryl includes, but is not limited to, phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl, 9-phenanthrenyl, etc.; wherein, C 7 -C 40 Alkyl-substituted aryl, for example, 2-methylphenyl, 2,6-dimethylphenyl, 2-fluoro-3-methylphenyl, 2-fluoro-4-methylphenyl, 2,6-difluoro-3-methylphenyl, 2,6-difluoro-4-methylphenyl, 2-chloro-3-methylphenyl, 2-chloro-4-methylphenyl, 2,6-dichloro-3-methylphenyl, 2,6-dichloro-4-methylphenyl, 2-ethylphenyl, 2,6-diethylphenyl, 2-isopropylphenyl, 2,6-diisopropylphenyl, 3-methylphenyl, and the like;

[0088] Furthermore, R 14 , R 14 ' can be independently selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl; further, R 16 , R 16 ' can be independently selected from hydrogen, C 1 -C 20 Straight-chain or branched, saturated or unsaturated, partially or fully halogenated, linear or cyclic carbon radicals;

[0089] R 17 , R 17 '、R 20 , R 21 , R 22 , R 23 are each independently selected from hydrogen, substituted or unsubstituted C 1 -C 40 One of the alkyl groups;

[0090] Specifically, substituted or unsubstituted C 1 -C 40 The alkyl group can be C 1 -C 40 A straight-chain or branched alkyl group, a saturated or unsaturated alkyl group, a halogenated or non-halogenated alkyl group, an alkyl group optionally containing heteroatoms of elements from Groups 13 to 17 of the Periodic Table, or a C 7 -C 40 Aryl substituted alkyl; for example, C 1 -C 40 Saturated and halogenated alkyl groups include, but are not limited to, methyl, trifluoromethyl, ethyl, 1,1,1-trifluoroethyl, perfluoroethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, n-heptyl, n-octyl, n-dodecyl, n-octadecyl, trimethylsilyl, triethylsilyl, triphenylsilyl, etc.; C 1 -C40 Unsaturated alkyl groups include, but are not limited to, vinyl, propenyl, allyl, etc.;

[0091] R 18 , R 24 are each independently selected from one of hydrogen and fluorine; further, R 18 , R 24 may each independently be selected from hydrogen;

[0092] R 25 , R 26 Each independently selected from hydrogen, fluorine, chlorine, bromine, -OR 27 、-SR 28 、-OCOR 29 、-N(R 30 ) 2 、-P(R 31 ) 2 One of them; further, R 25 , R 26 Each is independently selected from one of hydrogen, fluorine, chlorine, ester group, alkoxy group, thiol group, amine group and phosphine group;

[0093] Among them, R 27 , R 28 , R 29 , R 30 , R 31 are each independently selected from substituted or unsubstituted C 1 -C 40 Alkyl, substituted or unsubstituted C 3 -C 40 Cycloalkyl, substituted or unsubstituted C 6- C 40 One of the aromatic groups;

[0094] Specifically, substituted or unsubstituted C 1 -C 40 The alkyl group can be C 1 -C 40 A straight-chain or branched alkyl group, a saturated or unsaturated alkyl group, a halogenated or non-halogenated alkyl group, an alkyl group optionally containing heteroatoms of elements from Groups 13 to 17 of the Periodic Table, or a C 7 -C 40 Aryl substituted alkyl; for example, C 1 -C 40 Saturated and halogenated alkyl groups include, but are not limited to, methyl, trifluoromethyl, ethyl, 1,1,1-trifluoroethyl, perfluoroethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, n-heptyl, n-octyl, n-dodecyl, n-octadecyl, trimethylsilyl, triethylsilyl, triphenylsilyl, etc.; C1 -C 40 Unsaturated alkyl groups include, but are not limited to, vinyl, propenyl, allyl, etc.;

[0095] Substituted or unsubstituted C 3 -C 40 The cycloalkyl group includes, but is not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, 1-adamantane, etc.;

[0096] Substituted or unsubstituted C 6 -C 40 Aryl includes, but is not limited to, phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthrenyl, 2-phenanthrenyl, 3-phenanthrenyl, 4-phenanthrenyl, 9-phenanthrenyl, etc.; wherein, C 7 -C 40 Alkyl-substituted aryl, for example, 2-methylphenyl, 2,6-dimethylphenyl, 2-fluoro-3-methylphenyl, 2-fluoro-4-methylphenyl, 2,6-difluoro-3-methylphenyl, 2,6-difluoro-4-methylphenyl, 2-chloro-3-methylphenyl, 2-chloro-4-methylphenyl, 2,6-dichloro-3-methylphenyl, 2,6-dichloro-4-methylphenyl, 2-ethylphenyl, 2,6-diethylphenyl, 2-isopropylphenyl, 2,6-diisopropylphenyl, 3-methylphenyl and the like.

[0097] In the present invention, the stabilizer has a structure shown in Formula V:

[0098] Formula V;

[0099] The stabilizer of the present invention is a novel alcohol amine polymerization stabilizer with melem as the main structure. Since each molecule thereof contains 6 hydroxyl groups and 3 tertiary amino groups, it has a higher concentration of hydroxyl groups and amino groups, can absorb moisture through hydrogen bonding and form a conductive layer on the surface, thereby reducing surface resistance, preventing static electricity accumulation, having a good antistatic effect, and only needing a small amount of addition in the metallocene catalyst composition to obtain a good antistatic effect. At the same time, the hydroxyl groups and amino groups contained in the alcohol amine structure can form hydrogen bonds, and its structure is relatively simple and symmetrical, and it is not easy to rearrange or decompose in a thermal environment, so the stabilizer of the present invention also has excellent thermal stability. The stabilizer of the present invention has good compatibility, ensuring the uniform distribution and lasting effect of the stabilizer.

[0100] In addition, metallocene catalysts usually have very high catalytic activity and can quickly initiate polymerization reactions. However, if the polymerization reaction speed is too fast, it is not only easy to form polymer deposition on the inner wall of the reactor, resulting in serious problems of sticking to the reactor, but also may cause the growth and morphology of polymer particles to be uncontrolled, thereby causing uneven polymer particles, irregular morphology, and difficulty in post-processing. Therefore, in order to solve the above problems, the present invention loads the main catalyst and stabilizer onto the carrier. Loading the main catalyst and stabilizer onto the carrier can improve the catalyst dispersibility, effectively increase the specific surface area of ​​the catalyst, help to more evenly carry out the polymerization reaction, and reduce the sticking phenomenon caused by the local reaction being too fast; at the same time, the catalyst is distributed on the carrier, and the reaction exotherm can be more evenly dispersed, thereby reducing the possibility of local overheating, helping to keep the temperature of the reaction system stable, improving the molecular weight distribution and morphology of the polymer, and then obtaining a more uniform particle size and better fluidity, simplifying the post-processing steps; in addition, the supported catalyst usually has better mechanical stability, can maintain activity and stability for a long time during the reaction, and reduce the risk of catalyst deactivation and reaction interruption.

[0101] The metallocene catalyst composition of the present invention can be obtained by compounding the main catalyst shown in formula I with the stabilizer shown in formula V and the carrier. The stabilizer shown in formula V has a good matching effect with the main catalyst and the carrier, and can promote the metallocene catalyst composition to have high fluidity and high bulk density, which is conducive to the transportation of the catalyst and the catalyst feed in the industrial production process. The stabilizer shown in formula V can also act with some active centers of the main catalyst, thereby suppressing the initial activity of the main catalyst, promoting the generation of static electricity and fine powder when the metallocene catalyst composition is used for olefin polymerization to be greatly reduced, and effectively avoiding the formation of flaking. The stabilizer can reduce the inhibition of catalytic activity as much as possible when ensuring that the metallocene catalyst composition stably catalyzes olefin polymerization. Through experimental verification, the polymer obtained by using the metallocene catalyst composition to carry out olefin polymerization has good morphology, high bulk density, narrow molecular weight distribution, and is not easy to agglomerate.

[0102] Furthermore, the molar ratio of the main catalyst to the stabilizer is 1:(0.1-1). Exemplarily, the molar ratio of the main catalyst to the stabilizer can be 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1 or a range consisting of any two of the above molar ratios. Limiting the molar ratio of the main catalyst to the stabilizer to meet the above range can promote a good matching effect between the main catalyst and the stabilizer, thereby improving the performance of the prepared polymer.

[0103] In the solution of the present invention, the carrier includes at least one of silica gel, composite silica gel and clay. When the carrier meets the above range, it helps to better play the role of loading, can further improve the polymer morphology, and reduce the phenomenon of reactant sticking to the kettle.

[0104] Further, the silica gel includes Lewis acid-modified silica gel;

[0105] Lewis acids include polymethylaluminoxane, modified polymethylaluminoxane or organoboron reagents;

[0106] The modified anion in the modified polymethylaluminoxane is selected from [Al(C 6 H 5 ) 4 ] - 、[(CH 3 )Al(C 6 F 5 ) 3 ] - 、[Al(C 6 F 5 ) 4 ] - 、[Al(2,6-(CH 3 ) 2 -C 6 H 3 ) 4 ] - 、[Al(2,4,6-(CH 3 ) 3 -C 6 H 2 ) 4 ] - 、[Al(2,3,5,6-(CH 3 ) 4 -C 6 H) 4 ] - 、[Al(3,5-(CH 3 ) 2 -C 6 H 3 ) 4 ] - 、[Al(3,4,5-(CH 3 ) 3 -C 6 H 2 ) 4 ] - 、[Al(2,6-(CH 3 ) 2 -C 6 F 3 ) 4 ] -、[Al(2,4,6-(CH 3 ) 3 -C 6 F 2 ) 4 ] - 、[Al(2,3,5,6-(CH 3 ) 4 -C 6 F) 4 ] - 、[Al(3,5-(CH 3 ) 2 -C 6 F 3 ) 4 ] - 、[Al(3,4,5-(CH 3 ) 3 -C 6 F 2 ) 4 ] - 、[Al(2,6-(CF 3 ) 2 -C 6 H 3 ) 4 ] - 、[Al(2,4,6-(CF 3 ) 3 -C 6 H 2 ) 4 ] - 、[Al(2,3,5,6-(CF 3 ) 4 -C 6 H) 4 ] - At least one of;

[0107] The anion in the organoboron reagent is selected from [B(C 6 H 5 ) 4 ] - 、[(CH 3 )B(C 6 F 5 ) 3 ] - ,[B(C 6 F 5 ) 4 ] - 、[B(2,6-(CH 3 ) 2 -C 6 H 3 ) 4 ] -、[B(2,4,6-(CH 3 ) 3 -C 6 H 2 ) 4 ] - 、[B(2,3,5,6-(CH 3 ) 4 -C 6 H) 4 ] - 、[B(2,6-(CF 3 ) 2 -C 6 H 3 ) 4 ] - 、[B(2,4,6-(CF 3 ) 3 -C 6 H 2 ) 4 ] - 、[B(2,3,5,6-(CF 3 ) 4 -C 6 H) 4 ] - 、[B(3,5-(CH 3 ) 2 -C 6 H 3 ) 4 ] - 、[B(3,4,5-(CH 3 ) 3 -C 6 H 2 ) 4 ] - 、[B(3,5-(CF 3 ) 2 -C 6 H 3 ) 4 ] - 、[B(3,4,5-(CF 3 ) 3 -C 6 H 2 ) 4 ] - 、[B(2,6-(CF 3 ) 2 -C 6 F 3 ) 4 ] - 、[B(2,4,6-(CF 3 ) 3 -C 6 F2 ) 4 ] - , [B(2,3,5,6-(CF 3 ) 4 -C 6 F) 4 ] - , [B(3,5-(CF 3 ) 2 -C 6 F 3 ) 4 ] - , [B(3,4,5-(CF 3 ) 3 -C 6 F 2 ) 4 ] - At least one of .

[0108] Lewis acid is a type of Lewis acidic substance with expanded volume, delocalized electrons and poor coordination. In the present invention, the Lewis acid used in the modified silica gel includes polymethylaluminoxane (PMAO), modified polymethylaluminoxane (MMAO) or an organic boron reagent having a chain, ring and cage structure equilibrium state in the solution. The present invention defines that the silica gel includes Lewis acid-modified silica gel, and defines the type of Lewis acid, and at the same time defines the selection range of the modified anion in the modified polymethylaluminoxane and the anion in the organic boron reagent, which helps to remove impurities in the silica gel, stabilize the active center of the main catalyst in the late stage of the polymerization reaction, and increase the activity period of the main catalyst.

[0109] The molar ratio of Lewis acid to main catalyst is (10-500): 1; regulating the molar ratio of Lewis acid to main catalyst to meet the above range helps to promote a good matching effect between modified silica gel and main catalyst, and further improve the activity period of main catalyst. Exemplarily, the molar ratio of Lewis acid to main catalyst can be 10: 1, 100: 1, 200: 1, 300: 1, 400: 1, 500: 1 or a range consisting of any two of the above molar ratios.

[0110] In a specific embodiment, the Lewis acid-modified silica gel is prepared by reacting silica gel and Lewis acid at 40° C.-80° C. for 5-8 h.

[0111] By limiting the reaction temperature and time of silica gel and Lewis acid, the Lewis acid-modified silica gel required by the present invention can be obtained simply, quickly and accurately.

[0112] To ensure the smooth progress of the reaction and reduce the occurrence of side reactions, the silica gel can be first evacuated and then cooled to room temperature under the protection of inert gas; thereafter, to promote sufficient reaction, the silica gel can be first dispersed in a homogeneous liquid medium, and the homogeneous liquid medium can be at least one of a saturated alkane liquid medium or an aromatic liquid medium, wherein the saturated alkane includes at least one of pentane and its isomers, hexane and its isomers, heptane and its isomers, or octane and its isomers, and the aromatic liquid medium includes at least one of benzene, toluene, xylene and its isomers, trimethylbenzene and its isomers, chlorobenzene, dichlorobenzene and its isomers, fluorobenzene, difluorobenzene and its isomers, or polyfluorobenzene and its isomers. Further, the homogeneous liquid medium can be at least one of toluene, hexane, and pentane; at the same time, to promote more uniform dispersion of the silica gel, the temperature can be maintained at 25-30°C, the stirring speed can be maintained at 100-300 rpm, and the time can be maintained at 30 min-60 min for dispersion; then, Lewis acid can be added to the dispersed silica gel for reaction, and after the reaction is completed, toluene is used for washing, and finally vacuum drying is performed to obtain Lewis acid-modified silica gel.

[0113] In one embodiment of the present invention, the preparation method of Lewis acid-modified silica gel is as follows:

[0114] Grace 955 silica gel was evacuated at 450°C for 3 hours, and then naturally cooled to room temperature under the protection of inert gas, and the silica gel was added to a flask containing toluene, and the temperature was maintained at 25°C, the stirring speed was 100 rpm, and the time was 1 hour. Then, a toluene solution containing 10wt% methylaluminoxane was added thereto, and the temperature was raised to 60°C, and the reaction was kept warm for 6 hours. After the reaction was completed, it was washed with toluene 3 times, and then vacuum dried to obtain methylaluminoxane-modified silica gel.

[0115] In addition, the metallocene catalyst composition of the present invention may also include a co-catalyst; the co-catalyst includes at least one of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisobutylaluminum, trihexylaluminum, tri-n-butylaluminum, triisopropylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldibenzylaluminum, ethyldi-p-tolylaluminum and diethylbenzylaluminum.

[0116] The cocatalyst of the present invention can be introduced into the metallocene catalyst composition by means of a stabilizer activator, that is, the cocatalyst and the stabilizer are reacted in advance to obtain an activated stabilizer, and then the activated stabilizer is put into the subsequent preparation experiment; at this time, the cocatalyst can be triisobutylaluminum; further, the molar ratio of the cocatalyst to the stabilizer can be (1-5): 1. Exemplarily, the molar ratio of the cocatalyst to the stabilizer can be 1:1, 2:1, 3:1, 4:1, 5:1 or a range consisting of any two of the above molar ratios.

[0117] The cocatalyst of the present invention can also be introduced into the metallocene catalyst composition by means of a main catalyst activator, that is, the cocatalyst and the main catalyst are reacted in advance to obtain an activated main catalyst, and then the activated main catalyst is put into a subsequent preparation experiment; at this time, the cocatalyst can be triethylaluminum or triisobutylaluminum; further, the molar ratio of the cocatalyst to the main catalyst can be (1-20): 1. Exemplarily, the molar ratio of the cocatalyst to the main catalyst can be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1 or a range consisting of any two of the above molar ratios.

[0118] The second aspect of the present invention provides a method for preparing a metallocene catalyst composition, comprising the following steps:

[0119] The main catalyst and the carrier are subjected to a first reaction to obtain a first reactant;

[0120] adding a stabilizer to the first reactant to carry out a second reaction to obtain a metallocene catalyst composition;

[0121] The temperature of the first reaction is 40-100°C and the time is 180-480 min;

[0122] The temperature of the second reaction is 40-80°C and the time is 50-480 min.

[0123] The present invention can simply and quickly obtain a metallocene catalyst composition by limiting the raw material sequence and the reaction temperature and time to meet the above ranges, and the metallocene catalyst composition itself has high fluidity and bulk density, so it is convenient for transportation and catalyst feeding in industrial production processes; when it is applied to olefin polymerization reactions, it can play a good antistatic role, and the obtained polymer has good morphology, high bulk density, and narrow molecular weight distribution, so it is not easy to agglomerate.

[0124] In the present invention, in order to promote sufficient contact between the raw materials and further promote the reaction to proceed fully, the main catalyst and the carrier can also be dispersed in a homogeneous liquid medium respectively, wherein the main catalyst and the carrier can be dispersed in toluene; in order to further promote the reaction of the main catalyst and the carrier, stirring can be performed on the basis of controlling the temperature and time of the first reaction, specifically, the stirring speed can be 100-300 rpm; after the first reaction is completed, the supernatant can be removed after sedimentation and stratification, and the obtained first reactant can be washed with an organic solvent such as toluene; then, a stabilizer is added to the first reactant, and hexane can also be added for better reaction, and finally the temperature and time of the second reaction are controlled, and vacuum drying can obtain a solid metallocene catalyst composition.

[0125] In one embodiment of the present invention, the main catalyst can be first dissolved in toluene to prepare a main catalyst toluene solution, and then the carrier is added to a flask filled with toluene, the main catalyst toluene solution is added to the flask at 25°C, stirred at a stirring speed of 100 rpm for 30 minutes, then heated to 60°C and kept warm for reaction for 3 hours, after sedimentation and stratification, the upper clear liquid is removed to obtain the reactant, the reactant is washed with toluene 3 times, and then a hexane solution and a stabilizer are added, and the reaction is carried out at 40°C for 1 hour, and vacuum drying is performed to obtain a metallocene catalyst composition.

[0126] In a specific embodiment, the preparation method of the main catalyst comprises the following steps:

[0127] The compound represented by formula a is reacted with the compound represented by formula b to obtain the main catalyst represented by formula I;

[0128]

[0129] In formula a, Q, A, and Z are defined as above, and LG is selected from hydrogen, an alkali metal element, or an organic free radical comprising one of Si, Ge, Sn, Pd, Zn, Ba, Mg, and Ca;

[0130] In formula b, M, X, and n are defined as above, T is selected from a monodentate or bidentate neutral ligand, and k is an integer between 0 and 3.

[0131] It is understood that LG is selected from hydrogen, alkali metal elements or organic free radicals including one of Si, Ge, Sn, Pd, Zn, Ba, Mg, and Ca; wherein the alkali metal element includes at least one of lithium, sodium, and potassium; the organic free radical of one of Si, Ge, Sn, Pd, Zn, Ba, Mg, and Ca can be Si(R 32 ) 3 , Ge(R 33 ) 3 Sn(R 34 )3 、Pd(R 35 ) 3 、Zn(R 36 )、Ba(R 37 )、Mg(R 38 ) and Ca(R 39 ), where R 32 -R 39 are each independently selected from substituted or unsubstituted C 1 -C 30 Alkyl, substituted or unsubstituted C 3 -C 30 Cycloalkyl, substituted or unsubstituted C 6 -C 30 One of the aromatic groups.

[0132] Specifically, substituted or unsubstituted C 1 -C 30 The alkyl group can be C 1 -C 30 A straight-chain or branched alkyl group, a saturated or unsaturated alkyl group, a halogenated or non-halogenated alkyl group, an alkyl group optionally containing heteroatoms of elements from Groups 13 to 17 of the Periodic Table, or a C 7 -C 30 substituted or unsubstituted C 6 -C 30 Aryl can also be C 7 -C 30 The alkyl group is substituted with an aryl group.

[0133] In addition, T is selected from monodentate or bidentate neutral ligands; wherein the monodentate ligands include ethers, thioethers, tertiary amines, tertiary phosphines, cyclic ethers, cyclic thioethers, ketones, substituted cyclic ketones, substituted pyridines, substituted pyrroles, substituted piperidines, esters, lactones, amides and lactams, for example, triphenyl, ammonia, and halogen ions.

[0134] Among them, bidentate ligands include ortho diethers, α,ω-diethers, ortho diamines, α,ω-diamines, ortho disulfides, α,ω-disulfides, ortho diphosphines and α,ω-diphosphines, for example, ethylenediamine, bipyridine, and phenanthroline.

[0135] In the present invention, the reaction medium of the main catalyst during the synthesis process is saturated C 5 -C 15 Alkanes, C 5 -C 15 At least one of the cycloalkanes, specifically, the reaction medium can be hexane, heptane, octane, toluene or xylene. In addition, the reaction temperature can be -5°C - +100°C.

[0136] In the scheme of the present invention, the stabilizer shown in formula V is prepared by reacting melem and acetaldehyde; the reaction temperature is 60° C.-90° C., the reaction time is 1-10 h, and the pH value is 8-9.

[0137] In a specific embodiment, in order to improve the yield of the stabilizer, acetaldehyde can be added to melem twice for reaction, first adding acetaldehyde solution to melem, and then adding sodium bicarbonate solution under stirring to provide an alkaline environment for preliminary reaction. After the reaction is completed, acetaldehyde solution can be continued to be added for reaction. In one embodiment of the present invention, melem can be weighed into a flask, acetaldehyde solution is added thereto, stirring is turned on, sodium bicarbonate solution is then added thereto, and the temperature is raised to 60°C, and the reaction is kept warm for 3 hours. After the reaction is completed, the temperature is lowered to room temperature, acetaldehyde solution is added thereto again, the temperature is raised to 90°C, and the reaction is kept warm for 5 hours. Finally, ethyl acetate can be added thereto, the layers are stirred and the organic phase is taken out, and the organic solvent is removed and then column chromatography and rotary evaporation are performed to obtain the stabilizer shown in Formula V.

[0138] In order to further promote the stabilizer of the present invention to play a role, a co-catalyst can be used to activate the stabilizer. The co-catalyst of the present invention can react with the six hydroxyl groups in the stabilizer, thereby reducing the effect of the stabilizer on the catalyst activity of the metallocene catalyst composition. Specifically, the stabilizer shown in formula V and the co-catalyst provided by the present invention can be dissolved in hexane, and after the stabilizer hexane solution is cooled to 10°C, the co-catalyst hexane solution is slowly added dropwise thereto, and after the addition is completed, the temperature is raised to 70°C and kept warm for 3 hours to obtain an activated stabilizer.

[0139] The present invention does not specifically limit the source of melem, which can be commercially available or prepared by conventional methods in the art. In a specific embodiment, melem can be prepared by the following method:

[0140] Weigh melamine into a flask, slowly heat to 250°C and keep the temperature for 9 hours, then continue to heat to 385°C-390°C and keep the temperature for 20 hours. Stop heating and wait for the reaction to slowly cool to room temperature to obtain melem.

[0141] The third aspect of the present invention provides an application of the metallocene catalyst composition or the metallocene catalyst composition prepared by the above preparation method in olefin polymerization.

[0142] The metallocene catalyst composition of the present invention is convenient for transportation and catalyst feeding in industrial production processes due to its high fluidity and bulk density; when applied to olefin polymerization, it can play a good antistatic role, and the obtained polymer has a good morphology, a high bulk density, and a narrow molecular weight distribution, so it is not easy to agglomerate. Therefore, the metallocene catalyst composition of the present invention can be applied to olefin polymerization, especially gas phase polymerization and slurry polymerization of olefins. At the same time, it is not only applicable to intermittent polymerization reactors but also to continuous production devices, and can achieve stable, efficient and continuous operation of the device.

[0143] Furthermore, the olefin polymerization may be ethylene polymerization, ethylene and long-chain alpha olefin polymerization, or long-chain alpha olefin polymerization. Specifically, the long-chain alpha olefin may be butene, hexene, or octene.

[0144] The technical solution of the present application will be further explained below in conjunction with specific examples. The experimental methods in the following examples that do not specify specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The reagents used are commercially available or available from public channels unless otherwise specified.

[0145] Example 1

[0146] This embodiment provides a metallocene catalyst composition, and the preparation method thereof is as follows:

[0147] (1) Preparation of modified silica gel carrier:

[0148] Grace 955 silica gel was evacuated at 450°C for 3 hours, and then naturally cooled to room temperature under nitrogen protection. 10 g of the above silica gel was weighed and added to a 250 mL flask containing 100 mL toluene, and the temperature was maintained at 25°C, the stirring speed was 100 rpm, and the time was 1 h. Then 40 g of toluene solution containing 10 wt% methylaluminoxane (MAO) was added thereto, and the temperature was raised to 60°C and kept for 6 hours. After the reaction was completed, it was washed with toluene 3 times, and 50 mL of toluene was used for each wash, and then vacuum dried to obtain 13 g of MAO-modified silica gel.

[0149] (2) Preparation of stabilizer:

[0150] Melem is prepared according to Formula 1, and the specific synthesis steps are as follows:

[0151] Equation 1;

[0152] Weigh 25 g (200 mmol) of melamine into a 100 mL two-necked flask and slowly heat it in an electric heating jacket salt bath. When the heating temperature reaches 250°C, a large amount of ammonia is released. Keep the reaction at this temperature for 9 hours, then continue to heat to 385°C-390°C and keep the reaction at this temperature for 20 hours. Stop heating and wait for the reaction to slowly cool to room temperature to obtain 16 g of melem. The melem product is an off-white powder with a yield of 73.4%.

[0153] The preparation of the hexane solution of melem ethanolamine compound is carried out according to equation 2, and the specific synthesis steps are as follows:

[0154] Equation 2;

[0155] Weigh 2.18 g (10 mmol) of melem into a 100 mL two-necked flask, add 20 ml of acetaldehyde solution, start stirring at 100 rpm, then add 10 ml of 10wt% sodium bicarbonate solution, heat to 60°C at a heating rate of 10°C / min, and keep warm for 3 hours. After the reaction is completed, cool to room temperature (25°C), add 10 ml of acetaldehyde solution, then heat to 90°C at a heating rate of 10°C / min, and keep warm for 5 hours. After the reaction is completed, add 50 ml of ethyl acetate, stir to separate and take out the organic phase, remove the organic solvent, and obtain 2.3 g of melem ethanolamine compound in the form of white powder by column chromatography and rotary evaporation, with a reaction yield of 48%.

[0156] Weigh 0.1 g (0.2 mmol) of the above melem ethanolamine compound and dissolve it in 9.4 mL of dry hexane, cool it to 10°C, and slowly add 0.6 ml of 1M (0.6 mmol) triisobutylaluminum hexane solution thereto using a dropping funnel. After the addition is completed, heat the mixture to 70°C at a heating rate of 6°C / min and keep the reaction for 3 hours to obtain a hexane solution of the modified melem ethanolamine compound with a concentration of 20 μmol / mL.

[0157] (3) Preparation of main catalyst:

[0158] The main catalyst is prepared according to equation 3, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula II, R 13 , R 13 '、R 14 , R 14 ' is selected from hydrogen, and the specific synthesis steps are as follows:

[0159] Equation 3;

[0160] 0.186 g (1 mmol) of the above-mentioned ligand dimethylsilylbiscyclopentadienyl was dissolved in 10 ml of dry methyl tert-butyl ether (MTBE), cooled to 0°C, 0.8 mL of 2.5 M (1.0 mmol) n-butyllithium (n-BuLi) hexane solution was added, the temperature was increased to 50°C at a heating rate of 5°C / min, and the reaction was stirred for 2 hours to obtain a ligand lithium salt solution.

[0161] Weigh 0.23 g (1.0 mmol) zirconium tetrachloride (ZrCl 4 ) was placed in a reaction bottle, 10 mL of anhydrous MTBE was added to the reaction bottle under nitrogen protection, and stirred in a low-temperature cold bath at -40°C for 20 min, and then the above-mentioned ligand lithium salt solution was slowly added dropwise to the reaction bottle for a total of 3 h. After the addition was completed, the temperature was raised to 25°C at a heating rate of 5°C / min, and the mixture was kept warm and stirred for 3 h at a stirring speed of 100 rpm. The solvent was vacuum-evacuated to constant weight to obtain the main catalyst Cat-1.

[0162] (4) Preparation of metallocene catalyst composition:

[0163] Dissolve 20 μmol of the main catalyst Cat-1 obtained in step (3) in 15 ml of toluene to prepare a main catalyst toluene solution. Add 1 g of the modified silica gel obtained in step (1) to a 50 mL flask containing 20 mL of toluene, add the main catalyst toluene solution to the flask at 25°C, stir at a stirring speed of 100 rpm for 30 minutes, then heat to 60°C at a heating rate of 10°C / min, and keep the temperature for reaction for 3 hours. After sedimentation and stratification, remove the supernatant to obtain the reactant. Wash the reactant with toluene 3 times, then add 20 mL of hexane solution and 0.5 mL of the stabilizer obtained in step (2), react at 40°C for 1 hour, and vacuum dry to obtain a metallocene catalyst composition.

[0164] Example 2

[0165] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 1, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-2. The preparation method thereof is similar to that of Embodiment 1, but the ligand raw materials used are different, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula II, R 13 , R 13 ' is selected from methyl, R 14 , R 14 ' is selected from hydrogen.

[0166] Example 3

[0167] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 1, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-3. The preparation method thereof is similar to that of Embodiment 1, but the ligand raw materials used are different, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula II, R 13 , R 13 ' is selected from hydrogen, R 14 , R 14 ' is selected from methyl.

[0168] Example 4

[0169] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 1, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-4. The preparation method thereof is similar to that of Embodiment 1, but the ligand raw materials used are different, wherein M is selected from Hf, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula II, R 13 , R 13 '、R 14 , R 14 ' is selected from hydrogen.

[0170] Example 5

[0171] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 1, except for step (4). In step (4) of this embodiment, the volume of the stabilizer obtained in step (2) added is 1.5 ml.

[0172] Example 6

[0173] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 1, except for step (4). In step (4) of this embodiment, the volume of the stabilizer obtained in step (2) added is 4 ml.

[0174] Example 7

[0175] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 1, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-5. The preparation method thereof is similar to that of Embodiment 1, but the ligand raw materials used are different, as shown in Formula 4, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH3 ) 2 , A and Z are selected from the π-ligands shown in formula III, R 15 Selected from methyl, R 16 , R 16 '、R 17 , R 17 '、R 18 Selected from hydrogen.

[0176] Equation 4;

[0177] Example 8

[0178] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 7, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-6. The preparation method thereof is similar to that of Embodiment 7, but the ligand raw materials used are different, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula III, R 15 , R 16 , R 16 '、R 17 , R 17 '、R 18 Selected from hydrogen.

[0179] Example 9

[0180] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 7, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-7. The preparation method thereof is similar to that of Embodiment 7, but the ligand raw materials used are different, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula III, R 15 , R 16 , R 16 ' is selected from methyl, R 17 , R 17 '、R 18 Selected from hydrogen.

[0181] Example 10

[0182] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 7, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-8. The preparation method thereof is similar to that of Embodiment 7, but the ligand raw materials used are different, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 )2 , A and Z are selected from the π-ligands shown in formula III, R 15 Selected from methyl, R 16 , R 16 'Selected from Ph, R 17 , R 17 '、R 18 Selected from hydrogen.

[0183] Embodiment 11

[0184] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 7, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-9. The preparation method thereof is similar to that of Embodiment 7, but the ligand raw materials used are different, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula III, R 15 Selected from methyl, R 16 , R 16 'Selected from p-MePh, R 17 , R 17 '、R 18 Selected from hydrogen.

[0185] Example 12

[0186] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 7, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-10. The preparation method thereof is similar to that of Embodiment 7, but the ligand raw materials used are different, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula III, R 15 Selected from methyl, R 16 , R 16 'Selected from Naphth, R 17 , R 17 '、R 18 Selected from hydrogen.

[0187] Example 13

[0188] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 7, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-11. The preparation method thereof is similar to that of Embodiment 7, but the ligand raw materials used are different, wherein M is selected from Hf, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2, A and Z are selected from the π-ligands shown in formula III, R 15 , R 17 , R 17 ' is selected from methyl, R 16 , R 16 'Selected from Ph, R 18 Selected from hydrogen.

[0189] Embodiment 14

[0190] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 7, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-12. The preparation method thereof is similar to that of Embodiment 7, but the ligand raw materials used are different, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula III, R 15 Selected from Ethyl, R 16 , R 16 'Selected from Ph, R 17 , R 17 '、R 18 Selected from hydrogen.

[0191] Embodiment 15

[0192] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 7, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-13. The preparation method thereof is similar to that of Embodiment 7, but the ligand raw materials used are different, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula III, R 15 , R 17 , R 17 '、R 18 Selected from methyl, R 16 , R 16 ' is selected from hydrogen.

[0193] Example 16

[0194] This embodiment provides a metallocene catalyst composition. The preparation method thereof can refer to that of Embodiment 7, except for step (3). The main catalyst obtained in step (3) of this embodiment is Cat-14. The preparation method thereof is similar to that of Embodiment 7, but the ligand raw materials used are different, wherein M is selected from Zr, X is selected from Cl, and Q is selected from -Si(CH 3 ) 2 , A and Z are selected from the π-ligands shown in formula III, R 15 , R17 , R 17 '、R 18 Selected from methyl, R 16 , R 16 'Selected from Ph.

[0195] Comparative Example 1

[0196] This comparative example provides a metallocene catalyst composition, and its preparation method can refer to Example 1, except that this comparative example does not contain step (2), that is, no stabilizer is used, and the step (4) is changed accordingly as follows: 20 μmol of the main catalyst Cat-1 is dissolved in 15 ml of toluene to prepare a main catalyst toluene solution. 1 g of modified silica gel is added to a 50 mL flask containing 20 mL of toluene, and the main catalyst toluene solution is added to the flask at 25°C, stirred at a stirring speed of 100 rpm for 30 minutes, then heated to 60°C at a heating rate of 10°C / min, and kept warm for reaction for 3 hours. After sedimentation and stratification, the supernatant is removed to obtain a reactant. The reactant is washed with toluene 3 times, and vacuum dried to obtain a metallocene catalyst composition.

[0197] Comparative Example 2

[0198] This comparative example provides a metallocene catalyst composition, and its preparation method can refer to Example 2, except that this comparative example does not contain step (2), that is, no stabilizer is used, and the step (4) is changed accordingly: 20 μmol of the main catalyst Cat-2 is dissolved in 15 ml of toluene to prepare a main catalyst toluene solution. 1 g of modified silica gel is added to a 50 mL flask containing 20 mL of toluene, and the main catalyst toluene solution is added to the flask at 25°C, stirred at a stirring speed of 100 rpm for 30 minutes, then heated to 60°C at a heating rate of 10°C / min, and kept warm for reaction for 3 hours. After sedimentation and stratification, the supernatant is removed to obtain a reactant. The reactant is washed with toluene 3 times and vacuum dried to obtain a metallocene catalyst composition.

[0199] Comparative Example 3

[0200] This comparative example provides a metallocene catalyst composition, and its preparation method can refer to Example 3, except that this comparative example does not contain step (2), that is, no stabilizer is used, and the step (4) is changed accordingly: 20 μmol of the main catalyst Cat-3 is dissolved in 15 ml of toluene to prepare a main catalyst toluene solution. 1 g of modified silica gel is added to a 50 mL flask containing 20 mL of toluene, and the main catalyst toluene solution is added to the flask at 25°C, stirred at a stirring speed of 100 rpm for 30 minutes, then heated to 60°C at a heating rate of 10°C / min, and kept warm for reaction for 3 hours. After sedimentation and stratification, the supernatant is removed to obtain a reactant. The reactant is washed with toluene 3 times and vacuum dried to obtain a metallocene catalyst composition.

[0201] Test Example 1: Olefin Slurry Polymerization

[0202] (1) After nitrogen is fully replaced in a 2 L stainless steel reactor, 700 ml of n-hexane and 2 mL of 1 mol / L triethylaluminum hexane solution are added thereto, stirring is started at 200 rpm, the temperature is raised to 50°C, and the reaction is carried out for 20 minutes. 75 mg of the metallocene catalyst composition powder in Example 1 is weighed and dissolved in 300 ml of hexane to obtain a metallocene catalyst composition hexane solution, which is added to the above reactor, and ethylene is introduced to make the total pressure in the reactor reach 1.1 MPa, and polymerization is carried out at 70°C for 1 hour. After the reaction is completed, the reactor is cooled to 25°C and stirring is stopped. After drying, 122 g of polyethylene powder 1 is obtained, and its PDI is 3.1.

[0203] (2) After nitrogen is fully replaced in a 2 L stainless steel reactor, 700 ml of n-hexane and 2 mL of 1 mol / L triethylaluminum hexane solution are added thereto, stirring is started at 200 rpm, the temperature is raised to 50°C, and the reaction is carried out for 20 minutes. 78 mg of the metallocene catalyst composition powder in Example 1 is weighed and dissolved in 300 ml of hexane to obtain a metallocene catalyst composition hexane solution, which is added to the above reactor, and ethylene is introduced to make the total pressure in the reactor reach 1.8 MPa, and polymerization is carried out at 70°C for 1 hour. After the reaction is completed, the reactor is cooled to 25°C and stirring is stopped. After drying, 289 g of polyethylene powder 2 is obtained, and its PDI is 3.0.

[0204] (3) After nitrogen is fully replaced in a 2 L stainless steel reactor, 700 ml of n-hexane and 25 ml of 1-hexene monomer are added thereto, stirred at 200 rpm at 25°C for 5 min, and then 2 mL of 1 mol / L triethylaluminum hexane solution is added, the temperature is raised to 50°C, and the reaction is carried out for 20 minutes. 72 mg of the metallocene catalyst composition powder in Example 1 is weighed and dissolved in 300 ml of hexane to obtain a metallocene catalyst composition hexane solution, which is added to the above reactor, and ethylene is introduced to make the total pressure in the reactor reach 1.8 MPa, and polymerization is carried out at 70°C for 1 hour. After the reaction is completed, the reactor is cooled to 25°C and stirring is stopped. After drying, 325 g of polyethylene powder 3 is obtained, and its PDI is 2.6.

[0205] (4) With reference to the preparation method of polyethylene powder 2, the metallocene catalyst composition powder in Example 1 was replaced with the metallocene catalyst composition powders in Examples 2-16 respectively and sequentially to obtain polyethylene powders 4-18.

[0206] (5) With reference to the preparation method of polyethylene powder 2, the metallocene catalyst composition powder in Example 1 was replaced with the metallocene catalyst composition powders in Comparative Examples 1-3 respectively and sequentially to obtain polyethylene powders 19-21.

[0207] The catalytic activity of polyethylene powder 1-21 in the polymerization reaction process was calculated. The polyethylene powder 1-21 obtained in Test Example 1 was subjected to gel permeation chromatography (GPC) using a GPC-IR high temperature gel chromatograph produced by Spanish polymerchar company. The bulk density of the polyethylene powder 1-21 obtained in Test Example 1 was tested according to the method specified in GBT16913.3-2008. The results can be seen in Table 1 and Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 ;in, Figure 1 is the molecular weight distribution curve of polyethylene powder 1, Figure 2 is the molecular weight distribution curve of polyethylene powder 2, Figure 3 is the molecular weight distribution curve of polyethylene powder 3, Figure 4 This is a graph showing the phenomenon of polyethylene powder 20 sticking to the reactor after the slurry polymerization reaction. Figure 5 This is a graph showing the phenomenon of polyethylene powder 21 sticking to the reactor after the slurry polymerization reaction. Figure 6This is a diagram showing the phenomenon of no sticking in the reactor after the slurry polymerization of polyethylene powder 2. This shows that the metallocene catalyst composition of the present invention can significantly improve the catalyst activity and reduce the sticking in the reactor by introducing a stabilizer, and the polyethylene obtained has a good morphology, a high bulk density, and a narrow molecular weight distribution.

[0208] Table 1

[0209]

[0210]

[0211] Test Example 2: Olefin Gas Phase Polymerization

[0212] The metallocene catalyst composition in Example 1 of the present invention is used to carry out gas phase polymerization of olefins using the Unipol polyethylene process. The fluidized bed reaction device of the Unipol polypropylene process includes a catalyst system, a refining system and a polymerization reaction system. The steps of starting up the reaction device are as follows:

[0213] (1) The refining system has been replaced and qualified, the gas phase polymerization reaction raw materials (ethylene and hydrogen) have been introduced into the refining system, and the catalyst and auxiliary system have been put into use normally and are in a circulating state;

[0214] (2) The reactor replacement leak detection is qualified;

[0215] (3) Filling the reactor with a seed bed and dehydrating the bed;

[0216] (4) introducing gas phase polymerization feedstock (ethylene and hydrogen) into the reactor to establish the composition;

[0217] (5) Adding a catalyst to establish a reaction;

[0218] After the reactor was started, it was confirmed that the hydrogen concentration was 100-110 ppm and the ethylene concentration was close to 70%; it was confirmed that the reactor R-2300 had reached 2.05 Mpa, and the R-2300 temperature was controlled at 74°C; it was confirmed that the catalyst feeder pressure gauge and differential pressure gauge were normal and easy to use, and the injection pipe was unobstructed. The program feeding system was started, the feeding time was set to 75 s, and the R-2300 material level LIC-23001 was set to 2.0 m. The discharge control program KC-23001 was started, and the addition amount of the metallocene catalyst composition was gradually adjusted according to the reaction state. The metallocene catalyst composition feed amount was 5 g / h, and the polyethylene discharge amount was 37 kg / h. The catalyst activity was calculated to be 7400gPE / gcat. After the reaction was continuously operated for 72 hours, the block discharge amount under a load of 15 tons / h was 5 kg, the wall temperature-reaction temperature was -5°C, and the catalyst operated smoothly.

[0219] The above experimental results show that the metallocene catalyst composition prepared by the present invention is suitable for a gas phase continuous device, especially for a Unipol continuous device.

[0220] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A metallocene catalyst composition, characterized in that It comprises a carrier and a main catalyst and a stabilizer loaded on the carrier; The main catalyst has a structure shown in Formula I: Formula I; In Formula I, M is selected from one of Zr, Hf, and Ti; X is selected from one of halogen and -R1; Q is selected from one of -C(R7)2- and -Si(R8)2-; wherein R1, R7, and R8 are each independently selected from hydrogen, substituted or unsubstituted C1-C 30 Alkyl, substituted or unsubstituted C3-C 30 cycloalkyl, substituted or unsubstituted C6-C 30 One of the aromatic groups; A and Z are each independently selected from one of the π-ligands shown in formula II, formula III, and formula IV: Formula II; Formula III; Formula IV; n is an integer from 1 to 4; R 13 , R 13 '、R 14 , R 14 'Each independently selected from one of hydrogen and methyl; R 15 One selected from hydrogen, methyl, and ethyl; R 16 , R 16 'Each independently select one of hydrogen, methyl, Ph, p-MePh, Naphth; R 17 , R 17 '、R 18 Each independently selects one of hydrogen and methyl; R 19 One selected from hydrogen, methyl, ethyl, isopropyl, tert-butyl, phenyl and benzyl; R 20 , R 21 , R 22 , R 23 are each independently selected from hydrogen, substituted or unsubstituted C1-C 40 One of the alkyl groups; R 24 Selected from hydrogen; R 25 , R 26 are each independently selected from hydrogen; The stabilizer has a structure shown in Formula V: Formula V.

2. The metallocene catalyst composition according to claim 1, characterized in that The molar ratio of the main catalyst to the stabilizer is 1:(0.1-1).

3. The metallocene catalyst composition according to claim 1 or 2, characterized in that The carrier includes at least one of silica gel, composite silica gel and clay.

4. The metallocene catalyst composition according to claim 3, characterized in that The silica gel includes Lewis acid-modified silica gel; The Lewis acid includes polymethylaluminoxane, modified polymethylaluminoxane or an organic boron reagent; The modified anion in the modified polymethylaluminoxane is selected from [Al(C6H5)4] - 、[(CH3)Al(C6F5)3] - 、[Al(C6F5)4] - 、[Al(2,6-(CH3)2-C6H3)4] - 、[Al(2,4,6-(CH3)3-C6H2)4] - 、[Al(2,3,5,6-(CH3)4-C6H)4] - 、[Al(3,5-(CH3)2-C6H3)4] - 、[Al(3,4,5-(CH3)3-C6H2)4] - 、[Al(2,6-(CH3)2-C6F3)4] - 、[Al(2,4,6-(CH3)3-C6F2)4] - 、[Al(2,3,5,6-(CH3)4-C6F)4] - 、[Al(3,5-(CH3)2-C6F3)4] - 、[Al(3,4,5-(CH3)3-C6F2)4] - 、[Al(2,6-(CF3)2-C6H3)4] - 、[Al(2,4,6-(CF3)3-C6H2)4] - 、[Al(2,3,5,6-(CF3)4-C6H)4] - At least one of; The anion in the organic boron reagent is selected from [B(C6H5)4] - 、[(CH3)B(C6F5)3] - 、[B(C6F5)4] - 、[B(2,6-(CH3)2-C6H3)4] - 、[B(2,4,6-(CH3)3-C6H2)4] - 、[B(2,3,5,6-(CH3)4-C6H)4] - 、[B(2,6-(CF3)2-C6H3)4] - 、[B(2,4,6-(CF3)3-C6H2)4] - 、[B(2,3,5,6-(CF3)4-C6H)4] - 、[B(3,5-(CH3)2-C6H3)4] - 、[B(3,4,5-(CH3)3-C6H2)4] - 、[B(3,5-(CF3)2-C6H3)4] - 、[B(3,4,5-(CF3)3-C6H2)4] - 、[B(2,6-(CF3)2-C6F3)4] - 、[B(2,4,6-(CF3)3-C6F2)4] - 、[B(2,3,5,6-(CF3)4-C6F)4] - 、[B(3,5-(CF3)2-C6F3)4] - 、[B(3,4,5-(CF3)3-C6F2)4] - At least one of .

5. The metallocene catalyst composition according to claim 4, characterized in that The Lewis acid-modified silica gel is prepared by reacting silica gel and Lewis acid at 40° C.-80° C. for 5-8 h.

6. The metallocene catalyst composition according to claim 1, characterized in that The metallocene catalyst composition also includes a co-catalyst; The co-catalyst includes at least one of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisobutylaluminum, trihexylaluminum, tri-n-butylaluminum, triisopropylaluminum, tricyclohexylaluminum, trioctylaluminum, triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldibenzylaluminum, ethyldi-p-tolylaluminum and diethylbenzylaluminum.

7. The method for preparing the metallocene catalyst composition according to any one of claims 1 to 6, characterized in that: The steps include: The main catalyst and the carrier are subjected to a first reaction to obtain a first reactant; adding a stabilizer to the first reactant to carry out a second reaction to obtain the metallocene catalyst composition; The temperature of the first reaction is 40-100°C and the time is 180-480 min; The temperature of the second reaction is 40-80°C and the time is 50-480 min.

8. The preparation method according to claim 7, characterized in that: The preparation method of the main catalyst comprises the following steps: The compound represented by formula a is reacted with the compound represented by formula b to obtain the main catalyst represented by formula I; In formula a, Q, A, and Z are defined as in claim 1, and LG is selected from hydrogen, an alkali metal element, or an organic free radical comprising one of Si, Ge, Sn, Pd, Zn, Ba, Mg, and Ca; In formula b, the definitions of M, X, and n are the same as those in claim 1, T is selected from a monodentate or bidentate neutral ligand, and k is an integer between 0 and 3.

9. The preparation method according to claim 7 or 8, characterized in that: The stabilizer shown in formula V is prepared by reacting melem and acetaldehyde; The reaction temperature is 60°C-90°C, the reaction time is 1-10 h, and the pH value is 8-9.

10. Use of the metallocene catalyst composition according to any one of claims 1 to 6 or the metallocene catalyst composition prepared by the preparation method according to any one of claims 7 to 9 in olefin polymerization.

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