Master catalyst for the preparation of ethylene copolymer modified poly(4-methyl-1-pentene) and use thereof

Abstract

The application provides a main catalyst for preparing ethylene copolymer-modified poly(4-methyl-1-pentene) and application thereof. The main catalyst for preparing ethylene copolymer-modified poly(4-methyl-1-pentene) has a structure shown in formula I, wherein R is selected from tert-butyl or isopropyl. When the main catalyst of the application is applied to a catalytic system for catalyzing the copolymerization reaction of ethylene and 4-methyl-1-pentene, high catalytic activity is exhibited, and the prepared ethylene copolymer-modified poly(4-methyl-1-pentene) has the advantages of adjustable ethylene mole insertion rate, high molecular weight, narrow molecular weight distribution and high isotacticity, and further has excellent toughness and processing performance, and has a wide market application prospect.

Description

Technical Field

[0001] This invention belongs to the field of olefin polymerization and relates to a main catalyst for preparing ethylene copolymerized modified poly(4-methyl-1-pentene) and its application. Background Technology

[0002] Poly(4-methyl-1-pentene) (PMP) is a crystalline resin with a stereoregular structure. Its unique structure endows it with excellent chemical resistance, mechanical properties, processability, electrical insulation properties, low dielectric properties, optical properties, air permeability, and easy peeling properties. Therefore, PMP has important applications in fiber materials, release materials, high-end medical materials, and electronic materials.

[0003] High isotactic poly(4-methyl-1-pentene) homopolymers have high melting temperatures, resulting in poor toughness and high brittleness. To improve the brittleness of poly(4-methyl-1-pentene) homopolymers, current industrial methods involve copolymerizing α-olefins (mainly 1-hexene and 1-octene) with 4-methyl-1-pentene using Ziegler-Natta catalysts or metallocene catalyst systems to prepare α-olefin copolymerized modified poly(4-methyl-1-pentene). Because α-olefins have long side chains, they can significantly improve the brittleness of the copolymer and enhance the toughness of poly(4-methyl-1-pentene); simultaneously, the introduction of α-olefins also slightly lowers the melting point and increases the melt index of the polymer, which is beneficial for subsequent processing. However, the sources of α-olefins are limited and their prices are high. Meanwhile, since both α-olefin and 4-methyl-1-pentene monomers are liquids at room temperature, incompletely converted monomers during production can increase the difficulty of subsequent separation and recovery; they can also easily lead to residual monomer odors on the polymer, thus affecting the quality of the polymer.

[0004] Ethylene, as an inexpensive, readily available, and abundant olefin monomer, typically exhibits very high reactivity in olefin polymerization. Ethylene copolymerization modification can yield ethylene-modified poly(4-methyl-1-pentene). Unlike the copolymerization modification of α-olefins (which involves side-chain flexibility), the introduction of flexible ethylene segments into the polymer backbone reduces the rigidity of the polymer chains, thus enhancing the polymer's toughness. Furthermore, the preparation process for ethylene gas is simpler and easier to separate compared to liquid α-olefins. However, due to the lower steric hindrance of ethylene monomers, current Ziegler-Natta catalysts or metallocene catalysts catalyze the copolymerization of ethylene and 4-methyl-1-pentene, resulting in 4-methyl-1-pentene copolymerized modified polyethylene with a melting point of ~120℃. The material properties exhibit those of linear low-density polyethylene, losing the superior properties of poly(4-methyl-1-pentene).

[0005] Therefore, it is of great significance to develop a catalytic system capable of preparing ethylene copolymerized poly(4-methyl-1-pentene). Summary of the Invention

[0006] This invention provides a main catalyst for preparing ethylene copolymerized modified poly(4-methyl-1-pentene), its preparation method, and its application. The main catalyst of this invention exhibits superior activation of 4-methyl-1-pentene in the copolymerization reaction of ethylene and 4-methyl-1-pentene, making the activity of the 4-methyl-1-pentene monomer higher than that of the ethylene monomer. This facilitates the coordination insertion of 4-methyl-1-pentene, thereby obtaining ethylene copolymerized modified poly(4-methyl-1-pentene). This main catalyst demonstrates high catalytic activity in the copolymerization reaction of ethylene and 4-methyl-1-pentene, and the prepared ethylene copolymerized modified poly(4-methyl-1-pentene) has advantages such as controllable ethylene insertion rate, high molecular weight, narrow molecular weight distribution, high isotacticity, and high melting temperature.

[0007] The first aspect of this invention provides a main catalyst for preparing ethylene copolymerized modified poly(4-methyl-1-pentene), said main catalyst having the structure shown in Formula I:

[0008]

[0009] In Formula I, R is selected from tert-butyl or isopropyl.

[0010] The compound shown in Formula I is a non-necropolis-bridged imine amine hafnium complex. This complex has low steric hindrance, which is conducive to the coordination insertion of the sterically hindered 4-methyl-1-pentene monomer. It exhibits a unique activation effect on the 4-methyl-1-pentene monomer. Compared with Ziegler-Natta catalysts and metallocene catalysts, the polymerization activity of the 4-methyl-1-pentene monomer is higher than that of ethylene in the copolymerization reaction of ethylene monomer and 4-methyl-1-pentene monomer. This can lead to the production of ethylene copolymerized modified poly(4-methyl-1-pentene). Furthermore, the ethylene insertion rate in the obtained ethylene copolymerized modified poly(4-methyl-1-pentene) can be adjusted in the range of 3 to 30 mol%. It also has the advantages of high copolymer molecular weight, narrow molecular weight distribution, and high isotacticity.

[0011] The inventors discovered that when R is selected from isopropyl, the main catalyst exhibits higher catalytic activity.

[0012] A second aspect of the present invention provides a method for preparing the above-mentioned main catalyst for preparing ethylene copolymerized modified poly(4-methyl-1-pentene), the preparation route of which is shown below:

[0013]

[0014] The specific steps include: 1) reacting methylglyoxal with 2,6-diisopropylaniline to obtain intermediate A; 2) reacting intermediate A with 1-phenanthreneamine to obtain intermediate B; 3) reacting intermediate B with a 2-R-substituted phenyl lithium compound to obtain intermediate C; 4) reacting intermediate C sequentially with alkyllithium and hafnium tetrahalide to obtain intermediate D; 5) reacting intermediate D with methylmagnesium halide to obtain the main catalyst shown in Formula I.

[0015] Steps 1) and 2) involve using arylamine compounds to condense the aldehyde and carbonyl groups in methylglyoxal to obtain an asymmetric aryl-substituted diimine intermediate B. In step 3), a phenyl lithium compound with R2 substitution at the 2-position is used as a nucleophile to nucleophilically add to intermediate B to obtain a bridgehead-substituted imine amine intermediate C, which is the ligand of the main catalyst. In step 4), alkyllithium is deprotonated from the secondary amine and then reacted with hafnium tetrahalide to obtain imine amine hafnium halide intermediate D. In step 5), intermediate D undergoes a Grignard reaction with methyl magnesium halide to obtain the main catalyst shown in Formula I.

[0016] In step 4), the alkyl lithium is preferably n-butyllithium, the hafnium tetrahalide is preferably hafnium tetrachloride, and in step 5), the methyl magnesium halide is preferably methyl magnesium bromide.

[0017] The selection of specific reaction conditions in steps 1) to 5) is a routine procedure for those skilled in the art with a background in organic synthesis, and will not be elaborated here.

[0018] A third aspect of the present invention provides a catalyst for preparing ethylene copolymerized modified poly(4-methyl-1-pentene), the catalyst comprising the main catalyst, co-catalyst and / or activator provided in the first aspect of the present invention.

[0019] Since the catalyst includes the main catalyst provided in the first aspect of the present invention, it has high catalytic activity, and the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared by the catalyst has the advantages of adjustable ethylene insertion rate, high molecular weight, narrow molecular weight distribution and high isotacticity.

[0020] Furthermore, the cocatalyst of the present invention is selected from boron compounds; and / or, the activator is selected from alkyl aluminum compounds.

[0021] Considering factors such as catalyst activity, selectivity, and cost, the boron compound is selected from [Ph3C][B(C6F5)4], B(C6F5)3, or a mixture of [Ph3C][B(C6F5)4] and B(C6F5)3, and the alkyl aluminum compound is selected from at least one of trimethylaluminum, triethylaluminum, and triisobutylaluminum. Further, the boron compound is preferably [Ph3C][B(C6F5)4], and the alkyl aluminum compound is preferably triisobutylaluminum.

[0022] Furthermore, through experimental exploration of the molar ratio of the main catalyst, co-catalyst, and activator in the catalyst, it was found that when the molar ratio of Hf element in the main catalyst, B element in the boron compound, and Al element in the alkylaluminum compound is 1:(1-3):(0-300), and more preferably 1:(1.2-2):(100-200), the catalyst has higher catalytic activity, and the prepared copolymer has both higher molecular weight and narrower molecular weight distribution.

[0023] The fourth aspect of the present invention provides a method for preparing ethylene copolymerized modified poly(4-methyl-1-pentene), the method comprising: using the catalyst provided in the third aspect of the present invention to catalyze the copolymerization reaction of ethylene monomer and 4-methyl-1-pentene monomer to obtain the ethylene copolymerized modified poly(4-methyl-1-pentene).

[0024] The catalyst of this invention exhibits high catalytic activity in the copolymerization reaction of ethylene monomer and 4-methyl-1-pentene. The ethylene copolymer-modified poly(4-methyl-1-pentene) prepared has an adjustable ethylene insertion rate, isotacticity of 4-methyl-1-pentene segments >98%, and a melting temperature of 200-234°C, resulting in better toughness and processing performance.

[0025] In the above copolymerization reaction, the parameters of the ethylene insertion rate, weight-average molecular weight, molecular weight distribution, isotacticity, and melting temperature of the ethylene copolymerized modified poly(4-methyl-1-pentene) can be controlled by changing the molar ratio of 4-methyl-1-pentene monomer to catalyst, the temperature of the copolymerization reaction, the pressure of the ethylene monomer introduced, and the solvent.

[0026] After optimizing the above reaction conditions, it was found that the preferred molar ratio of 4-methyl-1-pentene monomer to the main catalyst in the catalyst is (10000~31800):1; the copolymerization temperature is 40~60℃; the preferred solvent for the copolymerization reaction is at least one of toluene, dichloromethane, n-hexane, and chlorobenzene, and more preferably toluene; the preferred pressure of the ethylene monomer is 0.3~10 atm.

[0027] By controlling factors such as the molar ratio of 4-methyl-1-pentene monomer to the main catalyst in the copolymerization reaction, polymerization temperature, polymerization solvent, and pressure of ethylene monomer, the ethylene molar insertion rate in the prepared ethylene copolymerized modified poly(4-methyl-1-pentene) can be achieved to be 3% to 30%, and further, the ethylene molar insertion rate can be achieved to be 10% to 25%. Through the random insertion of the above-mentioned ethylene content, the copolymer has better toughness and processing performance.

[0028] Furthermore, the ethylene copolymer-modified poly(4-methyl-1-pentene) prepared by the above copolymerization reaction has a melting temperature of 200-234℃ and an isotacticity of >98%, which further ensures that the copolymer has good toughness and processing performance.

[0029] Compared with the prior art, the present invention has at least the following beneficial effects:

[0030] 1) The main catalyst provided by this invention is a non-necrobridged imine amine complex. This complex has small steric hindrance, which is conducive to the coordination insertion of sterically hindered 4-methyl-1-pentene monomer. It exhibits a unique activation effect on 4-methyl-1-pentene monomer. In the copolymerization reaction of ethylene monomer and 4-methyl-1-pentene, the polymerization activity of 4-methyl-1-pentene monomer can be higher than that of ethylene, thereby obtaining ethylene copolymerized modified poly(4-methyl-1-pentene) with adjustable ethylene molar insertion rate. In addition, the obtained copolymer also has the advantages of high molecular weight, narrow molecular weight distribution, high isotacticity and high melting temperature, thus having better toughness and processing performance.

[0031] 2) The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared by this invention has the advantages of abundant and inexpensive monomer ethylene compared to the currently commercially available α-olefin copolymerized modified poly(4-methyl-1-pentene). At the same time, in industry, ethylene as a gas has the advantages of simple preparation process and easy separation compared to liquid α-olefins.

[0032] 3) The method for preparing ethylene copolymerized modified poly(4-methyl-1-pentene) provided by the present invention has the advantages of mild and efficient reaction conditions and easy operation. Attached Figure Description

[0033] Figure 1 Image of the ethylene copolymer-modified poly(4-methyl-1-pentene) sample prepared in Example 2;

[0034] Figure 2 The 1H NMR spectrum of the ethylene copolymerized poly(4-methyl-1-pentene) prepared in Example 2;

[0035] Figure 3 The carbon NMR spectrum of the ethylene copolymerized poly(4-methyl-1-pentene) prepared in Example 2 is shown.

[0036] Figure 4 The DSC curve of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared in Example 2 is shown.

[0037] Figure 5 The image shows the GPC curve of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared in Example 2. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0039] The following detailed description, with reference to specific embodiments, provides the main catalyst for preparing ethylene copolymerized modified poly(4-methyl-1-pentene), its preparation method, and its application.

[0040] It should be noted that, unless otherwise specified, the raw materials used in the following embodiments can be obtained by commercial purchase or conventional methods, and the experimental methods without specific conditions are all conventional methods and conditions well known in the art.

[0041] The catalytic activity calculation formula for the main catalyst in the following examples and comparative examples is: Catalytic activity = Mass (g) of ethylene copolymerized modified poly(4-methyl-1-pentene) / (Amount of main catalyst added (mol) × Reaction time (h);

[0042] The weight-average molecular weight and molecular weight distribution index of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared in the following examples and comparative examples were determined by GPC.

[0043] The melting temperatures of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared in the following examples and comparative examples were all determined by DSC thermal analysis.

[0044] The isotacticity of the ethylene copolymerized poly(4-methyl-1-pentene) prepared in the following examples and comparative examples was determined by carbon nuclear magnetic resonance spectroscopy.

[0045] The ethylene molar insertion rate of the ethylene copolymerized poly(4-methyl-1-pentene) prepared in the following examples and comparative examples was determined by 1H NMR spectroscopy.

[0046] Example 1

[0047] The preparation process of the main catalyst, the catalyst itself, and the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment is as follows:

[0048] 1) Preparation of main catalyst P1

[0049] The preparation route is shown below:

[0050]

[0051] The preparation steps include:

[0052] a. Add 0.79 g (11 mmol) of S1 (methylglyoxal), 50 mL of ethanol and a catalytic amount of formic acid to a reaction flask, mix well, and then slowly add 1.77 g (10 mmol) of 2,6-diisopropylaniline to the reaction flask. After the addition is complete, stir the reaction for 12 h, concentrate the reaction system to remove the solvent, and purify the concentrate by silica gel column chromatography (eluent is a mixed solvent of n-hexane and ethyl acetate with a volume ratio of 50:1) to obtain compound S2 with a yield of 93%.

[0053] b. Dissolve 0.93 g (4 mmol) of compound S2 in 50 mL of toluene, then slowly add 0.97 g (5 mmol) of 1-phenanthreneamine and a catalytic amount of p-toluenesulfonic acid, heat to reflux, react for 12 h, cool and concentrate to remove solvent, purify the concentrate by column chromatography (eluent is a mixed solvent of n-hexane and ethyl acetate in a volume ratio of 50:1) to give compound S3 in 86% yield;

[0054] c. At -40°C, 2.03 g (5 mmol) of compound S3 was dissolved in anhydrous diethyl ether, and 0.84 g (6 mmol) of 2-tert-butylphenyllithium in diethyl ether solution was slowly added dropwise. After the addition was complete, the reaction system was allowed to rise naturally to room temperature and reacted overnight. After the reaction was detected by TLC, a saturated solution of ammonium chloride was added to the reaction system to quench the reaction. The system was extracted three times with anhydrous diethyl ether, and the diethyl ether phase was collected. The diethyl ether phase was washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a concentrate. Ethanol was added to the concentrate and recrystallized to obtain ligand L1 in 83% yield.

[0055] The characterization data for ligand L1 are as follows:

[0056] 1 H NMR (CD3Cl, 400MHz): δ (ppm) 8.94 (d, 1H, Phen-H), 8.84 ( d, 1H, Phen-H), 8.05-7.66 (d,5H,Phen-H),7.60-6.95(m,9H,Ar-H),6.64(s,1H,CNH),4.17(s,1H,NCH),3.34( sept,1H,CH(CH3)2),3.02(sept,1H,CH(CH3)2),1.39(d,6H,CH(CH3)2),1.30(s,9H ,C(CH3)3),1.22(d,3H,CH(CH3)2),0.90(d,3H,CH(CH3)2),0.57(d,3H,CH(CH3)2).

[0057] Anal.Calcd for C 39 H 44 N2:C,86.62;H,8.20;N,5.18;Found:C,86.69;H,8.15;N,5.16.

[0058] d. Under a nitrogen atmosphere, ligand L1 1.08 g (2 mmol) was added to a dry Schlenk flask and dissolved in 20 mL of toluene. A 1.5 mL (1.6 M) solution of n-butyllithium was added dropwise to the Schlenk flask at -50 °C. After the addition was complete, the flask was allowed to cool naturally to room temperature. Once the reaction was complete, the solvent was removed by vacuum, and a yellow powder precipitated. The powder was washed three times with n-hexane, and after removing the hexane, a yellow lithium salt ligand was obtained. The yellow lithium salt ligand was dissolved in toluene and transferred to a reaction flask. HfCl4 was then added... 0.71 g (2.2 mmol) of toluene suspension was also added to the reaction flask, and the temperature was raised to 120 °C and reacted for 6 hours to obtain a reaction system containing compound S4. The reaction system was allowed to cool naturally to room temperature, and then placed in a low-temperature bath to cool to -40 °C. Then, MeMgBr (2.5 mL, 3 M) was slowly added dropwise to the reaction system. After the addition was complete, the mixture was allowed to rise naturally to room temperature and stirred for 6 hours. The precipitate was removed by filtration, and then washed three times with toluene. The filtrates were combined and the solvent in the filtrate was removed by vacuum distillation to obtain a solid. The solid was washed three times with n-hexane and dried to obtain the main catalyst P1, a yellow solid with a yield of 56%.

[0059] The characterization data of the main catalyst P1 are as follows:

[0060] 1 H NMR(C6D6,400MHz): δ(ppm)8.96(d,1H,Phen-H),8.88(d,1H,Phen-H),8.16(d,1H,Phen-H),7.97(d,1H, Phen-H),7.70(d,1H,Phen-H),7.63-6.91(m,10H,Ar-H),4.18(s,1H,NCH),3.16(sept,1H,CH(CH3)2),2. 96(sept,1H,CH(CH3)2),1.37(d,3H,CH(CH3)2),1.32(d,3H,CH(CH3)2),1.23(s,9H,C(CH3)3),1.00(d,3 H,CH(CH3)2),0.87(s,3H,Hf-CH3),0.72(d,3H,CH(CH3)2),0.59(s,3H,Hf-CH3),0.33(d,3H,CH(CH3)2).

[0061] MS-EI (m / z): 748.33 (M + ).

[0062] Anal.Calcd for C 41 H 48 N2Hf:C,65.89;H,6.47;N,3.75;Found:C,65.97;H,6.45;N,3.79.

[0063] 2) The preparation of ethylene copolymerized modified poly(4-methyl-1-pentene) involves the following specific steps:

[0064] The reaction flask was continuously evacuated and dried with an infrared lamp for two hours. After natural cooling, 5 mL of toluene solvent and 3 mL of 4-methyl-1-pentene monomer were added sequentially, followed by triisobutylaluminum. The temperature was maintained at 40℃ and stirred for half an hour. Then, a 1 μmol solution of 2 mL toluene was prepared by mixing the main catalyst P1 with boride [Ph3C][B(C6F5)4] at a molar ratio of 1:1.5 and injected into the reaction flask. The ethylene pressure was increased to 0.5 atm to start the copolymerization reaction. After polymerization for 5 minutes, the pressure in the reaction flask was released, and then an ethanol solution acidified with hydrochloric acid was added to terminate the copolymerization reaction. The copolymerization reaction system was filtered, and the filter cake was washed three times with ethanol and dried under vacuum to constant weight to obtain ethylene copolymerized modified poly(4-methyl-1-pentene). The molar ratio of 4-methyl-1-pentene monomer to main catalyst P1 was 23900:1, and the molar ratio of aluminum in triisobutylaluminum to Hf in main catalyst P1 was 100:1.

[0065] In this embodiment, the catalytic activity of the main catalyst P1 in the above copolymerization reaction is 16.2 kg polymer / (mmolHf·h), and the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 254 kg / mol, a molecular weight distribution index of 5.1, a melting temperature of 231 °C, an isotacticity of >98%, and a molar insertion rate of ethylene of 20.1%.

[0066] Example 2

[0067] The preparation process of the main catalyst, the catalyst itself, and the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment is as follows:

[0068] 1) Preparation of main catalyst P2

[0069]

[0070] The preparation steps of the main catalyst P2 in this embodiment are basically the same as those of the main catalyst P1 in Example 1. The difference is that 2-tert-butylphenyllithium in step c is replaced with 2-isopropylphenyllithium, the product of step c is ligand L2, the yield of step c is 87%, and the yield of step d is 55%.

[0071] The structural formula of ligand L2 is as follows:

[0072]

[0073] The characterization data for ligand L2 are as follows:

[0074] 1 1H NMR (CD3Cl, 400 MHz): δ (ppm) 8.82 (d, 1H, Phen-H), 8.09 (d, 1H, Phen-H), 8.00 - 7.64 (d, 5H, Phen-H), 7.57 - 6.71 (m, 9H, Ar-H), 5.92 (s, 1H, CNH), 4.00 (s, 1H, NCH), 2.97 (sept, 2H, CH(CH3)2), 1.86 (sept, 1H, CH(CH3)2), 1.31 (d, 6H, CH(CH3)2), 1.20 (s, 9H, C(CH3)3), 1.14 (d, 3H, CH(CH3)2), 0.97 (d, 3H, CH(CH3)2).

[0075] Anal. Calcd for C 38 H 42 N2: C, 86.64; H, 8.04; N, 5.32; Found: C, 86.69; H, 8.01; N, 5.30.

[0076] The characterization data of the main catalyst P2 are as follows:

[0077] 1 1H NMR (C6D6, 400 MHz): δ (ppm) 8.94 (d, 1H, Phen-H), 8.85 (d, 1H, Phen-H), 8.08 (d, 1H, Phen-H), 7.92 (d, 1H, Phen-H), 7.69 (d, 1H, Phen-H), 7.52 - 6.83 (m, 10H, Ar-H), 3.93 (s, 1H, NCH), 3.47 (sept, 1H, CH(CH3)2), 3.21 (sept, 1H, CH(CH3)2), 2.77 (sept, 1H, CH(CH3)2), 1.41 (d, 3H, CH(CH3)2), 1.39 (d, 3H, CH(CH3)2), 1.17 (d, 3H, CH(CH3)2), 1.10 (s, 3H, C-CH3), 1.03 (d, 3H, CH(CH3)2), 0.84 (s, 3H, Hf-CH3), 0.63 (d, 3H, CH(CH3)2), 0.56 (s, 3H, Hf-CH3), 0.38 (d, 3H, CH(CH3)2).

[0078] MS-EI (m / z): 732.31 (M + ).

[0079] Anal. Calcd for C 40 H46 N2Hf:C,65.52;H,6.32;N,3.82;Found:C,65.60;H,6.25;N,3.79.

[0080] 2) The preparation of ethylene copolymerized modified poly(4-methyl-1-pentene) is basically the same as that in Example 1, except that the main catalyst P1 in Example 1 is replaced with the main catalyst P2 in this example.

[0081] Calculations show that the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 22.7 kg polymer / (mmolHf·h).

[0082] The properties of the ethylene copolymerized modified poly(4-methyl-1-pentene) obtained in this example were observed. Figure 1 The image shows a sample of ethylene copolymerized modified poly(4-methyl-1-pentene) prepared in Example 2. Figure 1 As shown, the ethylene copolymerized modified poly(4-methyl-1-pentene) obtained in this embodiment is a white solid.

[0083] The ethylene copolymer-modified poly(4-methyl-1-pentene) prepared in this example was characterized using data. Figure 2 The 1H NMR spectrum of the ethylene copolymerized poly(4-methyl-1-pentene) prepared in Example 2; Figure 3 The carbon NMR spectrum of the ethylene copolymerized poly(4-methyl-1-pentene) prepared in Example 2; Figure 4 The DSC curve of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared in Example 2 is shown. Figure 5 The image shows the GPC curve of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared in Example 2.

[0084] Through the Figure 5 Analysis shows that the ethylene copolymer-modified poly(4-methyl-1-pentene) prepared in this embodiment has a weight-average molecular weight of 386 kg / mol and a molecular weight distribution index of 6.2; through analysis of... Figure 3 Analysis shows that the isotacticity of the ethylene copolymer-modified poly(4-methyl-1-pentene) prepared in this embodiment is >99%; through analysis of... Figure 2 Analysis shows that the molar insertion rate of ethylene in the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared in this embodiment is 23.1%; through analysis of... Figure 5 Analysis shows that the melting temperature of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared in this embodiment is 233℃.

[0085] Example 3

[0086] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0087] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the boride [Ph3C][B(C6F5)4] is replaced with B(C6F5)3.

[0088] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 24.7 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 392 kg / mol, a molecular weight distribution index of 6.0, a melting temperature of 233 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 22.8%.

[0089] Example 4

[0090] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0091] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that triisobutylaluminum is replaced with trimethylaluminum.

[0092] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 23.9 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 302 kg / mol, a molecular weight distribution index of 5.7, a melting temperature of 233 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 21.6%.

[0093] Example 5

[0094] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0095] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that triisobutylaluminum is replaced with triethylaluminum.

[0096] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 24.6 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 389 kg / mol, a molecular weight distribution index of 6.1, a melting temperature of 233 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 22.5%.

[0097] Example 6

[0098] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0099] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the molar ratio of the main catalyst P2 to the boride [Ph3C][B(C6F5)4] is changed from 1:1.5 to 1:1.

[0100] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 18.7 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 306 kg / mol, a molecular weight distribution index of 5.4, a melting temperature of 233 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 21.1%.

[0101] Example 7

[0102] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0103] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the molar ratio of the main catalyst P2 to the boride [Ph3C][B(C6F5)4] is replaced from 1:1.5 to 3:1.

[0104] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 30.6 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 405 kg / mol, a molecular weight distribution index of 4.7, a melting temperature of 234 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 24.2%.

[0105] Example 8

[0106] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0107] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that triisobutylaluminum is not added during the preparation process.

[0108] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 8.1 kg polymer / (mmol Hf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 165 kg / mol, a molecular weight distribution index of 3.2, a melting temperature of 230 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 19.4%.

[0109] Example 9

[0110] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0111] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the molar ratio of aluminum in triisobutylaluminum to Hf in the main catalyst P2 is replaced from 100:1 to 300:1.

[0112] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 48.0 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 465 kg / mol, a molecular weight distribution index of 6.5, a melting temperature of 234 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 16.0%.

[0113] Example 10

[0114] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0115] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the temperature of the copolymerization reaction is changed from 40°C to 20°C.

[0116] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 13.1 kg polymer / (mmolHf·h), and the weight-average molecular weight of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared is 72 kg / mol, the molecular weight distribution index is 4.1, the melting temperature is 234 °C, the isotacticity is >99%, and the molar insertion rate of ethylene is 18.0%.

[0117] Example 11

[0118] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0119] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the temperature of the copolymerization reaction is changed from 40°C to 80°C.

[0120] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 18.3 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 165 kg / mol, a molecular weight distribution index of 5.2, a melting temperature of 231 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 19.0%.

[0121] Example 12

[0122] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0123] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the temperature of the copolymerization reaction is changed from 40°C to 100°C.

[0124] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 2.1 kg polymer / (mmol Hf·h), and the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 78 kg / mol, a molecular weight distribution index of 7.5, a melting temperature of 229 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 20.1%.

[0125] Example 13

[0126] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0127] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the pressure of the ethylene monomer is replaced from 0.5 atm to 0.1 atm.

[0128] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 11.7 kg polymer / (mmolHf·h), and the weight-average molecular weight of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared is 102 kg / mol, the molecular weight distribution index is 3.4, the melting temperature is 234 °C, the isotacticity is >99%, and the molar insertion rate of ethylene is 3.0%.

[0129] Example 14

[0130] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0131] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the pressure of the ethylene monomer is replaced from 0.5 atm to 10 atm.

[0132] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 26.4 kg polymer / (mmolHf·h), and the weight-average molecular weight of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared is 287 kg / mol, the molecular weight distribution index is 4.4, the melting temperature is 228 °C, the isotacticity is >99%, and the molar insertion rate of ethylene is 25.6%.

[0133] Example 15

[0134] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0135] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the pressure of the ethylene monomer is replaced from 0.5 atm to 20 atm.

[0136] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 20.7 kg polymer / (mmolHf·h), and the weight-average molecular weight of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared is 252 kg / mol, the molecular weight distribution index is 2.9, the melting temperature is 200℃, the isotacticity is >99%, and the molar insertion rate of ethylene is 30.0%.

[0137] Example 16

[0138] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0139] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the molar ratio of 4-methyl-1-pentene monomer to main catalyst P2 is replaced from 23900:1 to 2000:1.

[0140] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 0.56 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 35 kg / mol, a molecular weight distribution index of 2.6, a melting temperature of 230 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 26.4%.

[0141] Example 17

[0142] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0143] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the molar ratio of 4-methyl-1-pentene monomer to main catalyst P2 is replaced from 23900:1 to 8000:1.

[0144] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 6.9 kg polymer / (mmol Hf·h), and the weight-average molecular weight of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared is 86 kg / mol, the molecular weight distribution index is 2.7, the melting temperature is 231 °C, the isotacticity is >99%, and the molar insertion rate of ethylene is 24.1%.

[0145] Example 18

[0146] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0147] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the molar ratio of 4-methyl-1-pentene monomer to main catalyst P2 is replaced from 23900:1 to 15900:1.

[0148] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 17.2 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 170 kg / mol, a molecular weight distribution index of 4.9, a melting temperature of 232 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 26.4%.

[0149] Example 19

[0150] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0151] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the molar ratio of 4-methyl-1-pentene monomer to main catalyst P2 is replaced from 23900:1 to 31800:1.

[0152] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 50.1 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 552 kg / mol, a molecular weight distribution index of 5.9, a melting temperature of 234 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 19.4%.

[0153] Example 20

[0154] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0155] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the copolymerization solvent is replaced with dichloromethane instead of toluene.

[0156] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 15.1 kg polymer / (mmolHf·h), and the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 160 kg / mol, a molecular weight distribution index of 3.4, a melting temperature of 234 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 12.0%.

[0157] Example 21

[0158] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0159] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the copolymerization solvent is replaced with n-hexane instead of toluene.

[0160] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 8.1 kg polymer / (mmol Hf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 184 kg / mol, a molecular weight distribution index of 3.8, a melting temperature of 234 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 15.2%.

[0161] Example 22

[0162] The main catalyst and its preparation method in this embodiment are the same as those in Example 2;

[0163] The preparation steps of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this embodiment are basically the same as those in Example 2, except that the copolymerization solvent is replaced with chlorobenzene instead of toluene.

[0164] In this embodiment, the catalytic activity of the main catalyst P2 in the above copolymerization reaction is 29.5 kg polymer / (mmolHf·h). The ethylene copolymerized modified poly(4-methyl-1-pentene) prepared has a weight-average molecular weight of 452 kg / mol, a molecular weight distribution index of 4.2, a melting temperature of 233 °C, an isotacticity of >99%, and a molar insertion rate of ethylene of 20.1%.

[0165] Comparative Example 1

[0166] The main catalyst used in this comparative example was a Ziegler-Natta catalyst (obtained commercially, product model CS-2).

[0167] The preparation method of the ethylene copolymerized modified poly(4-methyl-1-pentene) in this comparative example is basically the same as that in Example 2, except that the main catalyst P2 in Example 2 is replaced with the Ziegler-Natta catalyst in this comparative example.

[0168] In this comparative example, the catalytic activity of the Ziegler-Natta catalyst in the above copolymerization reaction was 0.89 kg polymer / (mmol Ti·h), the weight-average molecular weight of the ethylene copolymerized modified poly(4-methyl-1-pentene) was 223 kg / mol, the molecular weight distribution index was 10.3, the melting temperature was 117 °C, the polymer was isotactic, and the molar insertion rate of ethylene was 89.5%.

[0169] Comparative Example 2

[0170] This comparative example uses a zirconocene catalyst to catalyze the copolymerization reaction of ethylene and 4-methyl-1-pentene. The structural formula of the zirconocene catalyst is as follows:

[0171]

[0172] The above catalyst can be prepared by referring to the method described in the literature J.Mol.Catal.A 1996,112:37.

[0173] The reaction flask was continuously evacuated and dried under an infrared lamp for two hours. After natural cooling, 5 mL of toluene solvent and 3 mL of 4-methyl-1-pentene monomer were added sequentially, followed by 20 mmol of methylaluminoxane (MAO). The temperature was maintained at 40 °C and stirred for half an hour. Then, 10 μmol of the main catalyst, zirconium oxyceramsite, was added to the reaction system, and the ethylene pressure was increased to 0.5 atm to initiate the copolymerization reaction. After 2 hours of polymerization, the pressure in the reactor was released, and then an ethanol solution acidified with hydrochloric acid was added to terminate the copolymerization reaction. The copolymerization reaction system was filtered, and the filter cake was washed three times with ethanol and dried under vacuum to constant weight to obtain ethylene copolymerized poly(4-methyl-1-pentene).

[0174] In this comparative example, the catalytic activity of the zirconium-based catalyst in the above copolymerization reaction was 0.015 kg polymer / (mmol Zr·h), and the weight-average molecular weight of the ethylene copolymerized modified poly(4-methyl-1-pentene) prepared was 32 kg / mol, the molecular weight distribution index was 3.1, the melting temperature was 161 °C, the isotacticity was 85%, and the molar insertion rate of ethylene was 39.2%.

[0175] For ease of comparison, the catalytic activity of the main catalysts prepared in the above examples and comparative examples, as well as the weight-average molecular weight, molecular weight distribution index, melting temperature, isotacticity, and ethylene insertion rate of the prepared ethylene copolymerized modified poly(4-methyl-1-pentene) are listed in Table 1.

[0176] In Table 1, M in the active unit of the main catalyst in Examples 1 to 21 is Hf, M is Ti in Comparative Example 1, and M is Zr in Comparative Example 2.

[0177] Table 1

[0178]

[0179] As shown in Table 1, compared with the main catalyst of this invention, the Ziegler-Natta catalyst cannot achieve the modification of poly(4-methyl-1-pentene) by ethylene. The resulting polymer is mainly composed of ethylene polymerization units. Furthermore, the Ziegler-Natta catalyst exhibits low catalytic activity, and due to its multiple active sites, the molecular weight distribution of the polymer is broadened, resulting in a melting temperature of 117°C and significantly reduced temperature resistance. While the zirconium-ceramic catalyst can catalyze the copolymerization of ethylene and 4-methyl-1-pentene, the resulting copolymer has a high ethylene content, leading to an excessively low melting temperature. Moreover, the catalytic activity of the zirconium-ceramic catalyst is as low as 0.015 kg polymer / (mmol Zr·h), which is approximately 1000 times lower than the catalyst activity in Example 2 of this invention. The copolymer also has a low molecular weight, with a weight-average molecular weight of 32 kg / mol, resulting in significantly reduced mechanical properties.

[0180] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A main catalyst for preparing ethylene copolymerized modified poly(4-methyl-1-pentene), characterized in that, The main catalyst has the structure shown in Formula I: Equation I In Formula I, R is selected from tert-butyl or isopropyl.

2. A catalyst for preparing ethylene copolymerized modified poly(4-methyl-1-pentene), characterized in that, The catalyst includes the main catalyst, co-catalyst, and / or activator as described in claim 1.

3. The catalyst according to claim 2, characterized in that, The cocatalyst is selected from boron compounds; and / or the activator is selected from alkyl aluminum compounds.

4. The catalyst according to claim 3, characterized in that, The boron compound is selected from at least one of [Ph3C][B(C6F5)4] and B(C6F5)3; and / or, The alkylaluminum compound is selected from at least one of trimethylaluminum, triethylaluminum, and triisobutylaluminum.

5. The catalyst according to claim 3 or 4, characterized in that, The molar ratio of Hf in the main catalyst, B in the boron compound, and Al in the alkylaluminum compound is 1:(1~3):(0~300).

6. A method for preparing ethylene copolymerized modified poly(4-methyl-1-pentene), characterized in that, The preparation method includes: using the catalyst according to any one of claims 2-5 to catalyze the copolymerization reaction of ethylene monomer and 4-methyl-1-pentene monomer to obtain the ethylene copolymerized modified poly(4-methyl-1-pentene).

7. The preparation method according to claim 6, characterized in that, The molar ratio of the 4-methyl-1-pentene monomer to the catalyst is (10000~31800):

1.

8. The preparation method according to claim 6 or 7, characterized in that, The pressure of the ethylene monomer is 0.3~10 atm, and the temperature of the copolymerization reaction is 20~60℃.

9. The preparation method according to claim 6, characterized in that, The ethylene molar insertion rate of the ethylene copolymerized poly(4-methyl-1-pentene) is 3% to 30%.

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