Catalyst for olefin polymerization and method for preparing the same

Abstract

The application provides an olefin polymerization catalyst and a preparation method thereof. The preparation method comprises the following steps: mixing a terminal silicon ether aliphatic amine and a salicylaldehyde compound to perform a condensation reaction, so as to obtain an organic ligand; mixing the organic ligand and silica gel to perform an elimination reaction, so as to obtain an intermediate product A; mixing the intermediate product A and a tetraamine metal compound to perform a complexation reaction, so as to obtain an intermediate product B; and mixing the intermediate product B, a co-catalyst and phenolic aluminum oxide to perform an activation reaction, so as to obtain the olefin polymerization catalyst. The catalyst obtained by the method has high catalytic activity, high metal loading and low cost.

Description

Technical Field

[0001] This invention relates to a catalyst for olefin polymerization and its preparation method, belonging to the field of olefin polymerization. Background Technology

[0002] Phenoxy-imine catalysts (FI catalysts) are a class of high-performance, highly distinctive single-site catalysts. Their core advantages lie in their ultra-high activity, excellent single-site characteristics (narrow molecular weight distribution, high stereoselectivity), outstanding copolymerization ability (especially with higher α-olefins and polar monomers), and high tunability. These advantages make them irreplaceable in the synthesis of high-performance, high-value-added polyolefin products (such as high syndiotactic polypropylene, high-performance elastomers, and functionalized polyolefins).

[0003] Currently, the mainstream method for producing polyolefins is using supported catalysts, which offer advantages such as universal equipment, relatively simple processes, no use of organic solvents, and non-sticking of product particles to the reactor. However, due to limitations in preparation methods, traditional supported catalysts have relatively low metal content after loading. Some catalyst adheres to the surface of the support through surface adsorption and detaches during slurry polymerization, resulting in multiple polymerization centers in the polymerization system and causing an excessively wide molecular weight distribution of the polyolefin product. Moreover, in traditional supported processes, after the catalyst is loaded onto the support surface, the metal centers easily react with the residual silanol groups on the support surface, altering the spatial structure of the active centers and thus losing their activity, preventing them from achieving the polymerization performance under homogeneous conditions. In addition, the preparation of traditional supported catalysts requires a large amount of co-catalysts such as MAO, which are expensive and increase costs.

[0004] Therefore, it is necessary to develop a new olefin polymerization catalyst to improve the above-mentioned problems. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a catalyst for olefin polymerization and its preparation method, wherein the catalyst has high catalytic activity, high metal loading, and low cost.

[0006] To achieve the above objectives, the present invention provides a method for preparing a catalyst for olefin polymerization, comprising the following steps:

[0007] A condensation reaction was carried out by mixing terminal silyl ether fatty amines and salicylaldehyde compounds to obtain organic ligands;

[0008] The organic ligand and silica gel were mixed to carry out an elimination reaction to obtain intermediate product A.

[0009] Intermediate product A is mixed with a tetraamine metal compound and subjected to a complexation reaction to obtain intermediate product B.

[0010] Intermediate product B, co-catalyst, and aluminum phenoloxide are mixed and activated to obtain a catalyst for olefin polymerization.

[0011] The organic ligand of this invention contains a silyl ether group at one end, which can react effectively with the hydroxyl groups remaining on the surface of the silica gel support to achieve an anchoring effect. The other end is a phenoxyimine organic ligand, which can complex with a tetraamine-based metal compound to obtain an integrated solid-phase FI catalyst. This catalyst has a sea urchin-like structure, so the metal at the polymerization center is no longer tightly attached to the support surface, but rather suspended on the support surface. This preserves the catalytic performance under homogeneous conditions to a greater extent, preventing catalyst loss, increasing metal loading, and retaining all the catalytic performance of the polymerization center, thereby improving the polymerization activity of the solid catalyst and reducing the amount of co-catalyst required. Simultaneously, this invention reduces the amount of traditional co-catalysts such as MAO by adding aluminum phenoloxide. Moreover, compared to the structural uncertainty of traditional co-catalysts such as MAO, the aluminum phenoloxide structure added in this invention is controllable, effectively stabilizing the cationic polymerization center and improving catalytic activity. Furthermore, the preparation method of this invention is simple and easy to implement, and the prepared catalyst has high catalytic activity and low cost. It can efficiently obtain polymer products with a narrow molecular weight distribution in olefin polymerization.

[0012] In some alternative embodiments, the terminal silyl ether fatty amine has the structural formula (RO)3SiCH2CH2CH2NH2, where R is selected from C1 to C10 alkyl groups.

[0013] In some alternative embodiments, the choice of metal element in the tetraamine metal compound is not particularly limited, and may be selected from tetraamine zirconium and / or tetraamine titanium.

[0014] In some optional embodiments, aluminum phenoloxide is obtained by reacting bridged biphenol with alkyl aluminum, and the preparation method can be found in CN119462345B. Specifically, aluminum phenoloxide is prepared by the following steps: under inert gas protection, using alkane as solvent, bridged biphenol reacts with alkyl aluminum at 20~90℃ for 10min~6h to obtain aluminum phenoloxide; wherein the molar ratio of bridged biphenol to alkyl aluminum is 1~3:1.

[0015] In some alternative embodiments, the structural formula of the salicylaldehyde compound is as follows: R1 and R2 are each independently selected from tert-butyl and adamantyl.

[0016] In some alternative implementations, the preparation route of the organic ligand is as follows:

[0017]

[0018] In some alternative implementations, the preparation route of intermediate product A is as follows:

[0019]

[0020] In some alternative implementations, the preparation route of intermediate product B is as follows:

[0021]

[0022] In some optional embodiments, the cocatalyst is selected from one or more combinations of methylaluminoxane, modified methylaluminoxane, and boron salt. The modified methylaluminoxane may be selected from MMAO-3 and / or MMAO-7; the boron salt may be selected from one or more combinations of [Ph3C][B(C6F5)4], [PhMe2NH][B(C6F5)4], and B(C6F5)3.

[0023] Furthermore, the molar ratio of the terminal silyl ether fatty amine and the salicylaldehyde compound is (0.8:1) to (1:2), preferably 1:1.

[0024] Furthermore, the weight ratio of silica gel to organic ligand is (3:1) to (100:1).

[0025] Furthermore, the number of moles of the tetraamine metal compound is 1 to 1.5 mmol per gram of intermediate product A.

[0026] Furthermore, when the co-catalyst is selected from methylaluminoxane and / or modified methylaluminoxane, the amount of the co-catalyst is 50 to 500 times the amount of the tetraamine metal compound. When the co-catalyst is selected from boron salts, the amount of the co-catalyst is 1 to 10 times the amount of the tetraamine metal compound.

[0027] Furthermore, the amount of aluminum phenoxylate is 0.5 to 10 times the amount of tetraamine metal compound.

[0028] Furthermore, the condensation reaction is carried out at a temperature of 80°C to 120°C for 6 to 12 hours. In some optional embodiments, the reaction is conducted under an inert gas atmosphere, where a terminal silyl ether fatty amine and a salicylaldehyde compound containing a sterically hindered group undergo a condensation reaction in a solvent to obtain an o-hydroxyimine organic ligand.

[0029] Furthermore, the elimination reaction temperature is 80℃~120℃, and the reaction time is 3h~30h, preferably 24h. In some optional embodiments, the elimination reaction is carried out under inert gas protection. Heat-treated silica gel is added to a solution of organic ligand and reaction solvent and refluxed. After the reaction is completed, the precipitate is collected after cooling, washed, and then the solvent is removed under reduced pressure to obtain intermediate product A.

[0030] Furthermore, the reaction temperature for the complexation reaction is 50℃~120℃, and the reaction time is 3h~30h. In some optional embodiments, the complexation reaction is carried out under inert gas protection. Intermediate product A is added to the reaction solvent, stirred, refluxed, and a tetraamine metal compound is added to react. After the reaction is completed, the precipitate is collected after cooling, washed, and then the solvent is removed under reduced pressure to obtain intermediate product B.

[0031] Furthermore, the activation reaction temperature is 30℃~100℃, and the reaction time is 3~30h. The activation reaction is carried out under inert gas protection. Intermediate product B is added to the reaction solvent, stirred, refluxed, and then the co-catalyst and aluminum phenoloxide are added. The mixture is then refluxed, allowed to stand, filtered, the filter residue is dried under vacuum, washed, and dried again to obtain the activated catalyst for olefin polymerization.

[0032] In some optional embodiments, the choice of reaction solvent in this invention is not particularly limited, and conventional reagents in the art can be used. For example, in some specific embodiments, the solvent is an alkane (e.g., n-hexane, cyclopentane, heptane, etc.) or toluene.

[0033] This invention also provides a catalyst for olefin polymerization, which is prepared by the aforementioned method. The structural formula of this catalyst for olefin polymerization is shown below:

[0034]

[0035] Furthermore, the catalyst of this invention can be better used for olefin polymerization, especially the polymerization of ethylene or α-olefins. Attached Figure Description

[0036] Figure 1 The DSC test results for the polymer of Example 14 are shown.

[0037] Figure 2 The DSC test results for the polymer of Example 17 are shown.

[0038] Figure 3 The GPC test pattern of the polymer in Example 17 is shown;

[0039] Figure 4 The DSC test results for the polymer of Example 13 are shown;

[0040] Figure 5 The GPC test pattern of the polymer in Example 13 is shown;

[0041] Figure 6 The DSC test results for the polymer of Example 18 are shown.

[0042] Figure 7 The GPC test pattern of the polymer of Example 18 is shown;

[0043] Figure 8 The DSC test results for the polymer of Example 19 are shown;

[0044] Figure 9 The GPC test graph of the polymer of Example 19 is shown;

[0045] Figure 10 The 1H NMR spectrum of silyl ether-based o-hydroxybenzylimine from Example 1 is shown.

[0046] Figure 11 The carbon NMR spectrum of silyl ether-based o-hydroxybenzylimine from Example 1 is shown.

[0047] Figure 12 The mass spectrum of silyl ether-based o-hydroxybenzylimine from Example 1 is shown;

[0048] Figure 13 The GPC test pattern of the polymer of Example 12 is shown. Detailed Implementation

[0049] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0050] Example 1

[0051] This embodiment provides a method for preparing an integrated solid-phase FI catalyst Xs-1, which includes the following steps:

[0052] (a) The preparation method of silyl ether-based o-hydroxybenzylimine is as follows:

[0053] Under nitrogen protection, 11 g of 3-(triethoxysilyl)propylamine (50 mmol, CAS No. 919-30-2) was added dropwise to a toluene solution of 11.7 g (50 mmol) of 3,5-di-tert-butylsalicylaldehyde. The reaction system was heated and kept under reflux. The heating intensity was controlled by maintaining a stable reflux droplet in a water separator when the system was heated to 100 °C. After stirring for 12 h, the solution was allowed to return to room temperature. The solution turned yellow and a small amount of precipitate formed. The precipitate was removed by filtration, and the filtrate was concentrated to obtain the product silyl ether o-hydroxybenzylimine in 95% yield. Figure 10 The 1H NMR spectrum of silyl ether-based o-hydroxybenzylimine from Example 1 is shown. Figure 11 The carbon NMR spectrum of silyl ether-based o-hydroxybenzylimine from Example 1 is shown. Figure 12 The mass spectrum of silyl ether-based o-hydroxybenzylimine from Example 1 is shown.

[0054] (II) The preparation method of the integral solid adjacent phenylhydroxyimine is as follows:

[0055] Silica gel activation: GraceDavison955 silica gel was placed in a fluidized bed with temperature control and electric heating device, heated to 600°C in 2 hours under high-purity nitrogen, and calcined at this temperature for 4 hours. Then it was cooled to room temperature under high-purity nitrogen protection and transferred to a glove box for storage until use.

[0056] 20g of activated GraceDavison 955 silica gel was placed in a bottle. 500mL of a toluene solution of 6g of the silyl ether-based o-hydroxybenzyl imine obtained from the above reaction was added to the silica gel. The reaction system was heated and kept under reflux. Heating was carried out at 100℃, with the heating intensity controlled by maintaining a stable reflux droplet in the separator. After vigorous stirring for 24 hours, the mixture was allowed to return to room temperature and stand. The solid was washed three times with toluene, and the remaining liquid was removed under vacuum to obtain a yellow solid, i.e., a monolithic solid o-hydroxybenzyl imine. Elemental analysis results are as follows: N 0.604 mmol / g, C 9.80 mmol / g, H 14.31 mmol / g, N:C:H = 1:15.2:23.7.

[0057] (III) The preparation method of the integrated solid-phase FI catalyst is as follows:

[0058] A toluene solution of tetradimethylaminozirconium (1.0 mmol) was slowly added dropwise to a toluene suspension of an integrated solid-phase FI catalyst (1.0 g) containing adjacent phenylhydroxyimine. The mixture was stirred vigorously at 80 °C for 12 h. After sedimentation, the supernatant was filtered off and the catalyst was washed three times with n-heptane. Excess solvent was removed under reduced pressure to obtain a yellow solid, which was the integrated solid-phase FI catalyst S-1. Elemental analysis results showed that the Zr content was 3.7%, equivalent to 0.41 mmol / g.

[0059] (iv) Activation of integrated solid-phase FI catalyst

[0060] 1.0 g (Zr 0.41 mmol / g) of integrated solid-phase FI catalyst S-1 was suspended in toluene. MAO (100 times the amount of zirconium metal) was added, and the reaction system was heated and kept under reflux. Heating was carried out at 100 °C, with the heating intensity controlled by maintaining a stable reflux droplet in the separator. Reflux was continued for 12 h, allowed to stand, filtered, and the filter residue was dried under vacuum. The residue was washed with heptane and dried again to obtain the activated integrated solid-phase FI catalyst Xs-1. Elemental analysis results showed: Zr content was 0.9%, and Al content was 12.5%.

[0061] Example 2

[0062] This embodiment provides a method for preparing an integrated solid-phase FI catalyst Xs-2, which differs from Example 1 only in that: trimethoxysilylpropylamine (CAS No. 13822-56-5) is used instead of 3-(triethoxysilyl)propylamine; and MAO is added at a concentration equivalent to 200 times the amount of zirconium metal.

[0063] The elemental analysis results of the activated integrated solid-phase FI catalyst Xs-2 are as follows: Zr content is 0.88% and Al content is 12.1%.

[0064] Example 3

[0065] This embodiment provides a method for preparing an integrated solid-phase FI catalyst Xs-3, which differs from Example 2 only in that MMAO-3 equivalent to 100 times the amount of metallic zirconium is added.

[0066] The elemental analysis results of the activated integrated solid-phase FI catalyst Xs-3 are as follows: Zr content is 0.86% and Al content is 12.3%.

[0067] Example 4

[0068] This embodiment provides a method for preparing an integrated solid-phase FI catalyst Xs-4, which differs from Example 2 only in that MMAO-3 equivalent to 200 times the amount of metallic zirconium is added.

[0069] The elemental analysis results of the activated integrated solid-phase FI catalyst Xs-4 are as follows: Zr content is 0.80% and Al content is 11.9%.

[0070] Example 5

[0071] This embodiment provides a method for preparing an integrated solid-phase FI catalyst Xs-5, which differs from Example 2 only in that MMAO-7 equivalent to 100 times the amount of metallic zirconium is added.

[0072] The elemental analysis results of the activated integrated solid-phase FI catalyst Xs-5 are as follows: Zr content is 0.83% and Al content is 12.0%.

[0073] Example 6

[0074] This embodiment provides a method for preparing an integrated solid-phase FI catalyst Xs-6, which differs from Example 2 only in that MMAO-7 equivalent to 200 times the amount of metallic zirconium is added.

[0075] The elemental analysis results of the activated integrated solid-phase FI catalyst Xs-6 are as follows: Zr content is 0.79% and Al content is 12.1%.

[0076] Example 7

[0077] This embodiment provides a method for preparing an integrated solid-phase FI catalyst Xs-7, which differs from Example 2 only in that: 100 times the amount of MAO and 100 times the amount of aluminum phenoloxide (the preparation method of aluminum phenoloxide is described in Example 1 of CN119462345B) are added.

[0078] The elemental analysis results of the activated integrated solid-phase FI catalyst Xs-7 are as follows: Zr content is 0.32% and Al content is 12.8%.

[0079] Example 8

[0080] This embodiment provides a method for preparing an integrated solid-phase FI catalyst Xs-8, which differs from Example 2 only in that: 100 times the amount of MAO and 200 times the amount of aluminum phenoloxide (the preparation method of aluminum phenoloxide is described in Example 1 of CN119462345B) are added.

[0081] The elemental analysis results of the activated integrated solid-phase FI catalyst Xs-8 are as follows: Zr content is 0.30% and Al content is 14.1%.

[0082] Example 9

[0083] This embodiment provides a method for preparing an integrated solid-phase FI catalyst Xs-9, which differs from Example 1 only in that: trimethoxysilylpropylamine is used instead of 3-(triethoxysilyl)propylamine; 3-adamantyl-5-tert-butylsalicylaldehyde (CAS No. 801288-07-3) is used instead of 3,5-di-tert-butylsalicylaldehyde; and 100 times the amount of MMAO-3 and 100 times the amount of aluminum phenoloxide (the preparation method of aluminum phenoloxide is described in Example 1 of CN119462345B) are added.

[0084] The elemental analysis results of the activated integrated solid-phase FI catalyst Xs-9 are as follows: Zr content is 0.35% and Al content is 12.3%.

[0085] Example 10

[0086] This embodiment provides a method for preparing an integrated solid-phase FI catalyst Xs-10, which differs from Example 9 only in that: 200 times the amount of metallic zirconium is added in aluminum phenoloxide (the preparation method of aluminum phenoloxide is described in Example 1 of CN119462345B).

[0087] The elemental analysis results of the activated integrated solid-phase FI catalyst Xs-10 are as follows: Zr content is 0.34% and Al content is 14.8%.

[0088] Comparative Example 1

[0089] This comparative example provides a method for preparing catalyst S1, which includes the following steps:

[0090] Take 1.0 mmol of conventional FI catalyst (0.40 g), mix with 200 mmol of MAO in toluene solution, stir for 30 min, add 1.0 g of activated silica gel, heat under reflux at 100 °C for 12 h, let stand, filter, wash three times with n-heptane, remove excess solvent under reduced pressure, and obtain a pink solid, which is the S1 catalyst. The FI catalyst is... .

[0091] Comparative Example 2

[0092] This comparative example provides a method for preparing catalyst S2, which differs from Comparative Example 1 only in that 300 mmol of MAO is used instead of 200 mmol of MAO.

[0093] Comparative Example 3

[0094] This comparative example provides a method for preparing catalyst S3, which differs from Comparative Example 1 only in that 300 mmol of isobutylaluminum is used instead of 200 mmol of MAO.

[0095] Example 11

[0096] This embodiment provides a method for olefin polymerization, which includes the following steps:

[0097] The polymerization reactor is equipped with a stirring rod, thermocouple, serpentine condenser, and automatic temperature control. Take 5 mg of the activated catalyst Xs-1 and place it in the pre-dried, dehydrated, and deoxygenated polymerization reactor. Add 10 mL of toluene, heat to the specified temperature of 70°C, introduce ethylene gas, maintain a constant pressure, and the polymerization reaction begins. The automatic temperature controller is used to control the temperature of the polymerization reaction, keeping temperature fluctuations within ±5°C. After 30 minutes, stop heating and stirring, turn off the condensate, close the ethylene inlet valve, and slowly cool to room temperature. Slowly open the pressure relief valve until the internal and external pressures are balanced. Open the reactor, pour the polymer toluene solution into a beaker, add 15 mL of ethanol, stir, and let stand overnight. Filter the obtained polymer, wash with ethanol, and then place it in a 60°C constant temperature vacuum drying oven to dry overnight.

[0098] Example 12

[0099] This embodiment provides a method for copolymerizing ethylene with α-olefins, which includes the following steps:

[0100] A clean, dry 250 mL stainless steel reactor was purged three times with ethylene. Then, 100 mL of dry toluene, 5.0 g of 1-hexene (0.15 mol / L), and 50 mg of the main catalyst Xs-2 were added sequentially. Methylaluminoxane (10.0 mmol, 1.9 g of 30 wt% toluene solution) was added to the reactor using a dry syringe. Ethylene was introduced, maintaining a pressure of 1 atm. The reaction mixture was stirred at 70 °C for 60 minutes, and then the reaction was terminated by adding a 5 wt% hydrochloric acid-ethanol solution. The resulting polymer was washed with ethanol, filtered, and dried in a vacuum oven at 60 °C for 24 hours. The polymer was a white powder with a bulk density of 0.35 g / cm³. 3 The polymer density is 0.925 g / cm³. 3 .

[0101] Example 13

[0102] This embodiment provides a method for copolymerizing ethylene with α-olefins, which includes the following steps:

[0103] A clean, dry 250 mL stainless steel reactor was purged three times with ethylene. Then, 100 mL of dry toluene, 15.0 g of 1-hexene (0.45 mol / L), and 50 mg of the main catalyst Xs-3 were added sequentially. Methylaluminoxane (10.0 mmol, 1.9 g of 30 wt% toluene solution) was added to the reactor using a dry syringe. Ethylene was introduced, maintaining a pressure of 1 atm. The reaction mixture was stirred at 50 °C for 60 minutes, and then the reaction was terminated by adding a 5% hydrochloric acid-ethanol solution. The resulting polymer was washed with ethanol, filtered, and dried in a vacuum oven at 60 °C for 24 hours. The polymer was a white powder with a bulk density of 0.38 g / cm³. 3 The polymer density is 0.890 g / cm³. 3 .

[0104] Example 14

[0105] This embodiment provides a method for copolymerizing ethylene with α-olefins, which includes the following steps:

[0106] A clean, dry 250 mL stainless steel reactor was purged three times with ethylene. Then, 100 mL of dry toluene, 15.0 g of 1-hexene (0.45 mol / L), and the main catalyst Xs-4 (45 mg) were added sequentially. Methylaluminoxane (10.0 mmol, 1.9 g of 30 wt% toluene solution) was added to the reactor using a dry syringe. Ethylene was introduced, maintaining a pressure of 1 atm. The reaction mixture was stirred at 50 °C for 60 minutes, and then the reaction was terminated by adding a 5% hydrochloric acid-ethanol solution. The resulting polymer was washed with ethanol, filtered, and dried in a vacuum oven at 60 °C for 24 hours. The polymer was a white powder with a bulk density of 0.37 g / cm³. 3 The polymer density is 0.895 g / cm³. 3 .

[0107] Example 15

[0108] This embodiment provides a method for copolymerizing ethylene with α-olefins, which differs from Example 14 only in that it uses the main catalyst Xs-5.

[0109] Example 16

[0110] This embodiment provides a method for copolymerizing ethylene with α-olefins, which differs from Example 14 only in that it uses the main catalyst Xs-6.

[0111] Example 17

[0112] This embodiment provides a method for copolymerizing ethylene with α-olefins, which differs from Example 14 only in that it uses the main catalyst Xs-7.

[0113] Example 18

[0114] This embodiment provides a method for copolymerizing ethylene with α-olefins, which differs from Example 14 only in that it uses the main catalyst Xs-8.

[0115] Example 19

[0116] This embodiment provides a method for copolymerizing ethylene with α-olefins, which differs from Example 14 only in that it uses the main catalyst Xs-9.

[0117] Example 20

[0118] This embodiment provides a method for copolymerizing ethylene with α-olefins, which differs from Example 14 only in that it uses the main catalyst Xs-10.

[0119] Comparative Example 4

[0120] This comparative example provides a method for copolymerizing ethylene with α-olefins, which differs from Example 14 only in the use of main catalyst S1.

[0121] Comparative Example 5

[0122] This comparative example provides a method for copolymerizing ethylene with α-olefins, which differs from Example 14 only in the use of main catalyst S2.

[0123] Comparative Example 6

[0124] This comparative example provides a method for copolymerizing ethylene with α-olefins, which differs from Example 14 only in the use of main catalyst S3.

[0125] Performance characterization: Catalyst activity was calculated by weighing. Elemental analysis was performed according to GB / T17359-2023. The polymer melting point (Tm, °C), crystallinity (Xc, %), and molecular weight (Mw and Mn, 10⁻⁶) were obtained by DSC and GPC tests. 5 (g / mol) and molecular weight distribution (PDI). Test data for Comparative Examples 4-6 are shown in Table 1. Test data for Examples 11-20 are shown in Table 2. Figure 1 The DSC test results for the polymer of Example 14 are shown. Figure 2 The DSC test results for the polymer of Example 17 are shown. Figure 3 The GPC test pattern of the polymer in Example 17 is shown; Figure 4 The DSC test results for the polymer of Example 13 are shown; Figure 5 The GPC test pattern of the polymer in Example 13 is shown; Figure 6 The DSC test results for the polymer of Example 18 are shown. Figure 7 The GPC test pattern of the polymer of Example 18 is shown; Figure 8 The DSC test results for the polymer of Example 19 are shown; Figure 9 Figure 19 shows the GPC test pattern of the polymer of Example 19; Figure 13 shows the GPC test pattern of the polymer of Example 12.

[0126] Table 1

[0127]

[0128] Table 2

[0129]

[0130] Table 2 (below)

[0131]

[0132] Compared to Comparative Examples 4-6, the catalysts obtained in Examples 11-20 of this invention exhibit higher catalytic activity and higher metal loading. Furthermore, the addition of aluminum phenoxylate further enhances the catalyst activity. We believe this activity originates from the Al-Me group in the molecule. As a derivative of trimethylaluminum, it can act as a donor for alkyl-Me groups, similar to the alkylation effect of MAO, and also as a coordinating ion to stabilize the polymerization active center. Experimental results show that adding 100 or 200 equivalents of aluminum phenoxylate can effectively increase the activity by 50%. Further increasing the amount is unnecessary because analysis of the aluminum content indicates that the amount of aluminum does not increase further. This suggests that the silica gel surface has reached saturation and cannot continue to load more co-catalyst. This invention provides a catalyst with higher catalytic activity and higher metal loading at a lower cost.

Claims

1. A method for preparing a catalyst for olefin polymerization, characterized in that, Includes the following steps: A condensation reaction was carried out by mixing terminal silyl ether fatty amines and salicylaldehyde compounds to obtain organic ligands; The organic ligand and silica gel were mixed and subjected to an elimination reaction to obtain intermediate product A. The intermediate product A is mixed with a tetraamine metal compound and subjected to a complexation reaction to obtain intermediate product B. The intermediate product B, the co-catalyst, and aluminum phenoxylate were mixed and activated to obtain a catalyst for olefin polymerization. The molar ratio of the terminal silyl ether fatty amine to the salicylaldehyde compound is (0.8:1) to (1:2); the reaction temperature of the condensation reaction is 80℃ to 120℃, and the reaction time is 6h to 12h; the amount of aluminum phenoloxide is 0.5 to 10 times the amount of the tetraamine metal compound. The intermediate product B has the following structure: R1 and R2 are each independently selected from tert-butyl and adamantyl, and M represents Ti or Zr; The structural formula of the salicylaldehyde compound is as follows: R1 and R2 are each independently selected from tert-butyl and adamantyl groups; The tetraamine-based metal compound is selected from tetraamine zirconium and / or tetraamine titanium.

2. The method for preparing the catalyst for olefin polymerization according to claim 1, characterized in that, The cocatalyst is selected from one or more combinations of methylaluminoxane, modified methylaluminoxane, and boron salts.

3. The method for preparing the catalyst for olefin polymerization according to claim 1, characterized in that, The weight ratio of the silica gel to the organic ligand is (3:1) to (100:1).

4. The method for preparing the catalyst for olefin polymerization according to claim 1, characterized in that, The molar amount of the tetraamine metal compound is 1 to 1.5 mmol per gram of intermediate product A.

5. The method for preparing the catalyst for olefin polymerization according to claim 2, characterized in that, When the cocatalyst is selected from the methylaluminoxane and / or the modified methylaluminoxane, the amount of the cocatalyst is 50 to 500 times the amount of the tetraamine metal compound. When the co-catalyst is selected from the boron salt, the amount of the co-catalyst is 1 to 10 times the amount of the tetraamine-based metal compound.

6. The method for preparing the catalyst for olefin polymerization according to claim 1, characterized in that, The elimination reaction is carried out at a temperature of 80℃ to 120℃ for a time of 3h to 30h.

7. The method for preparing the catalyst for olefin polymerization according to claim 1, characterized in that, The complexation reaction is carried out at a temperature of 50℃ to 120℃ and for a time of 3h to 30h.

8. The method for preparing the catalyst for olefin polymerization according to claim 1, characterized in that, The activation reaction is carried out at a temperature of 30℃ to 100℃ for a duration of 3h to 30h.

9. A catalyst for olefin polymerization, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 8.

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