Method for preparing olefin block copolymer through continuous series reactor and single ethylene raw material

Abstract

The invention discloses a method for preparing an olefin block copolymer through continuous series reactors and a single ethylene raw material, and belongs to the technical field of olefin block copolymers. The method comprises the following steps: (1) continuously adding an oligomerization catalyst solution, a first cocatalyst solution, ethylene gas and a solvent into a micro-channel reactor, and carrying out an oligomerization reaction; after the reaction, conveying the materials to a kettle type reactor; (2) continuously adding a copolymerization catalyst solution, a second cocatalyst solution, ethylene gas and toluene into the tank reactor for copolymerization; and conveying the material into industrial alcohol to terminate the reaction, collecting a polymerization product, and drying to obtain the product. The method is simple in process, the polymerization process is easy to control, and the product performance can be flexibly adjusted; according to the method, expensive alpha-olefin does not need to be added, two non-metallocene catalysts do not need to be used at the same time, a chain shuttling agent does not need to be introduced, the production cost is reduced, and the problem that an oligomerization catalyst interferes with a copolymerization catalyst is solved.

Description

Technical Field

[0001] This invention relates to the field of olefin block copolymer technology, and more specifically, to a method for preparing olefin block copolymers using a single ethylene feedstock in a continuous series reactor. Background Technology

[0002] Olefin block copolymers (OBCs) are ethylene / 1-octene copolymers with alternating "soft" and "hard" segments, exhibiting high elasticity, high heat resistance, and high abrasion resistance, as well as excellent processability. They can be used for toughening and foaming modification of plastics, showing promising application prospects. Currently, only Dow Chemical can produce OBCs using chain shuttle polymerization technology. However, this technology has the following drawbacks: 1. The production cost of raw materials is high due to the need to introduce α-olefin monomers into the reaction; 2. Two non-metallocene catalysts are required during polymerization, resulting in complex polymerization kinetics, high process control costs, difficulty in controlling the polymer structure, and increased production costs due to the introduction of two catalysts; 3. The need for chain shuttles in the reaction, which can induce chain transfer during polymerization, makes it difficult to synthesize high molecular weight OBCs. Patent CN115594806A discloses an [N,P]-type non-metallocene catalyst for the preparation of olefin block copolymers. This catalyst can simultaneously possess two structures at a certain temperature: one structure catalyzes the homopolymerization of ethylene, and the other structure catalyzes the copolymerization of ethylene and α-olefins. Thus, the synthesis of olefin block copolymers can be achieved using only one catalyst, resulting in a simple process that eliminates the need for chain shuttles. However, this process still requires the addition of a large amount of α-olefin monomers for copolymerization, leading to high production costs.

[0003] As is well known, α-olefin monomers can be obtained by catalytic oligomerization of ethylene using oligomerization catalysts. A common method for preparing ethylene / α-olefin copolymers from a single ethylene feedstock is through cascade catalytic processes (first performing ethylene oligomerization, then introducing the oligomer product into the next batch for copolymerization). For example, patents CN113248643A and CN114920866B both used this cascade catalytic process to prepare polyolefin elastomers (POE). However, traditional cascade catalytic processes still have certain drawbacks: the yield of α-olefins during ethylene oligomerization cannot be precisely controlled, thus making it impossible to accurately regulate the copolymer content in the product; and there are also drawbacks such as kinetic mismatch and mutual interference between the oligomerization catalyst and the copolymerization catalyst in the catalytic system.

[0004] Patent CN118341362A proposes a microchannel reactor with advantages such as high-efficiency mass transfer, stable temperature control, and adjustable process. The microchannel reactor features continuous plug flow reaction, enabling precise control of the reaction progress and thus the yield of α-olefins during oligomerization. Therefore, combining the microchannel reactor with cascade catalysis: introducing an oligomerization catalyst into the microchannel reactor to precisely control the oligomerization reaction process and α-olefin yield, followed by introducing the cascaded oligomerization products and copolymerization catalyst into a batch reactor to obtain the corresponding ethylene / α-olefin copolymer. This innovative design effectively solves the problems of inaccurate control of the copolymer content in the product and the mismatch between oligomerization and copolymerization kinetics in the catalytic system. However, when these oligomerization products containing the oligomerization catalyst are transported in series to the batch reactor for copolymerization, the residual oligomerization catalyst interacts with the subsequent copolymerization catalyst. This interaction affects the efficiency of the copolymerization reaction and the control of the product structure by occupying active sites, altering the electronic environment, or initiating unnecessary chain transfer reactions, leading to catalyst deactivation or side reactions. This is the so-called "interference between oligomerization catalysts and copolymerization catalysts in the catalytic system." Therefore, the seamless transition from oligomerization to copolymerization in a microchannel-stage dual-reactor system requires ensuring that the products from the microchannel stage (including α-olefins and residual oligomerization catalyst) do not negatively impact subsequent reactions when entering the stage. Consequently, the copolymerization catalyst design must not only be interference-resistant itself but also coordinated with the process parameters of the microchannel stage (such as solvent selection and residual catalyst concentration) to ensure overall process compatibility. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of high cost and complex process in existing olefin block copolymer preparation processes, and to provide a method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock. This invention combines a cascade catalytic process that reduces production costs, a microchannel reactor that allows for high-precision control of the oligomerization reaction progress (ethylene conversion or α-olefin yield), and a [N,P]-type non-metallocene catalyst that can prepare olefin block copolymers under a single master catalyst. The invention achieves the preparation of ethylene / α-olefin block copolymers through a cascade catalytic process involving oligomerization in a microchannel reactor and copolymerization in a batch reactor using a single ethylene feedstock. The production process is relatively simple, and the segmented oligomerization and copolymerization processes effectively control the monomer content in the copolymerization product and avoid mismatches in oligomerization and copolymerization kinetics within the catalytic system. Furthermore, by optimizing the ligand steric hindrance design, electronic effects, and synergistic process parameters of the [N,P]-type non-metallocene catalyst in the copolymerization stage, the invention solves the problem of mutual interference between the oligomerization and copolymerization catalytic active centers when the oligomerization product containing oligomerization catalytically active species is transported to the copolymerization batch reactor, achieving seamless integration of oligomerization and copolymerization under a microchannel-batch dual-reactor system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock includes the following steps:

[0008] (1) The oligomerization catalyst solution, the first co-catalyst solution, ethylene gas and solvent are continuously added to the microchannel reactor, and the oligomerization reaction is carried out at the preset reaction temperature. The oligomerization reaction time is controlled by controlling the average residence time of the reactants in the microchannel reactor. After the reaction, the materials are transported to the batch reactor through the series pipeline.

[0009] (2) Add copolymerization catalyst solution, second co-catalyst solution, ethylene gas and toluene continuously to a batch reactor and carry out copolymerization reaction at a preset reaction temperature. Control the reaction time by controlling the average residence time of the reactants in the batch reactor. Then, the material is transported to industrial alcohol to terminate the reaction, the polymerization product is collected and dried to obtain olefin block copolymer.

[0010] The present invention is further configured such that the oligomerization catalyst solution is a solution of one of bis(2-decylthioethyl)amine-CrCl3 (bis(2-decylthioethyl)amine chromium chloride), bis(2-dodecylsulfanyl-ethyl)amine-CrCl3 (bis(2-dodecylthioethyl)amine chromium chloride), and (Ph2PCH2CH2NH2)2CrCl3 ([bis(diphenylphosphineethylamine)]chromium chloride(III)).

[0011] The present invention is further configured such that the first cocatalyst solution is a solution of one of methylaluminoxane and modified methylaluminoxane.

[0012] The present invention is further configured such that, in step (1), the solvent used in the oligomerization catalyst solution and the solvent used in the first co-catalyst solution are the same, and are all one of hexane, heptane, octane and decane.

[0013] The present invention is further configured such that the copolymerization catalyst is a [N,P]-type non-metallocene catalyst, with the following general structural formula:

[0014]

[0015] In the formula, R1 is one of 2,6-dimethylphenyl, 2,6-difluorophenyl, and 2,6-diisopropylphenyl; R2 and R3 are both one of 2,4,6-trimethylphenyl and 2,4,6-trifluorophenyl; M represents one of the transition metals Ti, Zr, and Hf; X is one of the halogen atoms Cl and Br; m=4; and 1≤n≤3.

[0016] When oligomers containing catalytically active species are transported to the copolymerization reactor, free chromium ions adsorb onto the active sites of [N,P]-type non-metallocene catalysts, occupying active sites and hindering the coordination and insertion of ethylene or α-olefins. Furthermore, the high oxidation state of chromium alters the electronic environment of the metal center of the [N,P]-type non-metallocene catalyst, inhibiting catalytic activity. Therefore, this invention employs sterically hindered aryl groups (such as 2,6-diisopropylphenyl) to modify the nitrogen-phosphine ligands of the [N,P]-type non-metallocene catalyst, forming a steric barrier to prevent free chromium species from approaching the metal active site. During the copolymerization stage, the PM bond reversibly breaks, releasing active sites, while sterically hindered ligand fragments temporarily occupy the surrounding space, further isolating free chromium. Using a group VB transition metal as the metal center of the [N,P]-type non-metallocene catalyst, under the synergistic stabilization of the lone pair electrons of nitrogen and the σ-electron-donating ability of phosphorus, the metal center forms highly reduced active species (such as Zr). 4+ The [N,P]-type non-metallocene catalyst is not sensitive to the oxidizing effects of chromium. The activity loss rate of the catalyst is <10% when the chromium residue is ≤100 ppm.

[0017] The present invention further specifies that the second cocatalyst solution is one of triethylaluminum and triisobutylaluminum. When the oligomerization product containing oligomerization catalytically active species is transported to the copolymerization reactor, chromium residues may catalyze non-selective chain transfer, leading to disordered block sequences in the resulting copolymer. Therefore, the present invention uses alkylaluminum (such as triisobutylaluminum) as a cocatalyst in the reactor stage to regulate the ligand dissociation equilibrium of the [N,P]-type non-metallocene catalyst, which preferentially reacts with free chromium ions to form inert aluminum-chromium complexes, inhibiting their catalytic non-selective chain transfer activity; methylaluminoxane / modified methylaluminoxane is used as a cocatalyst in the microchannel stage to enhance the oligomerization activity of the chromium catalyst; a non-polar solvent (such as hexane) is used in the microchannel stage to limit the dissolution of chromium species; and the reactor stage is supplemented with the weakly polar solvent toluene to promote the dissolution of the [N,P]-type non-metallocene catalyst while simultaneously precipitating chromium residues.

[0018] The present invention is further configured such that, in step (1), under a single average residence time, the molar concentration of the oligomerizing catalyst in the microchannel reactor is 1~25 μmol / L, and the molar ratio of the first co-catalyst to the oligomerizing catalyst is (50~1000):1, and the molar ratio of ethylene to the oligomerizing catalyst introduced into the microchannel reactor is (1×10⁻⁶). 5 ~1.5×10 6 ):1.

[0019] The present invention is further configured such that, in step (1), the oligomerization reaction temperature is 40-90℃ and the average residence time of the reactants in the microchannel reactor is 10-60 min.

[0020] The present invention is further configured such that, in step (2), the molar ratio of the copolymerization catalyst to the oligopolymerization catalyst in step (1) is (0.1~20):1, the molar ratio of the second cocatalyst to the copolymerization catalyst is (100~800):1, and the molar ratio of ethylene to the copolymerization catalyst introduced into the batch reactor is (1×10⁻⁶). 6 ~1×10 7 ):1; The solvents used in the copolymerization catalyst solution and the second co-catalyst solution are both toluene, and the toluene concentration in the batch reactor is 1~10 mol / L under a single average residence time.

[0021] The present invention is further configured such that, in step (2), the copolymerization reaction temperature is 80℃-180℃, and the average residence time of the reactants in the batch reactor is 5-30 min.

[0022] In summary, the present invention has the following beneficial effects:

[0023] 1. By combining a microchannel reactor with a cascade catalytic process, olefin block copolymers were prepared using a single ethylene feedstock, a microchannel-tandem double reactor, and an [N,P]-type non-metallocene catalyst. Compared to Dow Chemical's polymerization technology for preparing olefin block copolymers via chain shuttle technology, this method is simpler, easier to control during polymerization, and allows for flexible adjustment of product performance. It eliminates the need for expensive α-olefins, the simultaneous use of two non-metallocene catalysts, and the introduction of chain shuttles, significantly reducing production costs.

[0024] 2. By designing the ligand steric hindrance of [N,P]-type non-metallocene catalysts, optimizing electronic effects, and synergizing oligomerization and copolymerization process parameters, the interference problem of oligomerization catalysts on copolymerization catalysts is solved, and seamless connection between oligomerization and copolymerization is achieved in a microchannel-stage dual reactor.

[0025] 3. The olefin block copolymers prepared by this method have excellent thermal and mechanical properties. Compared with the OBCs commercially available from Dow Chemical, they have higher molecular weights and can impart higher tensile strength. Attached Figure Description

[0026] Figure 1 The melting curve of the olefin block copolymer product of Example 1 is shown below.

[0027] Figure 2 The melting curve of the olefin block copolymer product from Example 1 after SSA treatment;

[0028] Figure 3 The temperature control flowchart for SSA treatment analysis of the olefin block copolymer product of Example 1 is shown.

[0029] Figure 4 The olefin block copolymer of Example 113 C-NMR spectrum. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention relates to a method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock, comprising the following steps:

[0032] (1) Add oligomerization catalyst solution, first co-catalyst solution, ethylene gas and solvent continuously to the microchannel reactor, and carry out oligomerization reaction for 10-60 min at a preset reaction temperature of 40-90℃. Control the oligomerization reaction time by controlling the average residence time of the reactants in the microchannel reactor. After the reaction, transport the materials to the batch reactor through a series pipeline.

[0033] The oligomerization catalyst solution is a solution of one of the following: bis(2-decylthioethyl)amine-CrCl3 (bis(2-decylthioethyl)amine chromium chloride), bis(2-dodecylsulfanyl-ethyl)amine-CrCl3 (bis(2-dodecylthioethyl)amine chromium chloride), or (Ph2PCH2CH2NH2)2CrCl3 ([bis(diphenylphosphineethylamine)]chromium chloride(III)). The first co-catalyst solution is a solution of one of methylaluminoxane or modified methylaluminoxane. The solvent used in the oligomerization catalyst solution and the first co-catalyst solution are the same, namely one of hexane, heptane, octane, or decane. At a single average residence time, the molar concentration of the oligomerization catalyst in the microchannel reactor is 1~25 μmol / L, and the molar ratio of the first co-catalyst to the oligomerization catalyst is (50~1000):1. The molar ratio of ethylene to the oligomerization catalyst introduced into the microchannel reactor is (1×10⁻⁶). 5 ~1.5×10 6 ):1.

[0034] (2) Add copolymerization catalyst solution, second co-catalyst solution, ethylene gas and toluene continuously to a batch reactor and carry out copolymerization reaction for 5-30 min at a preset reaction temperature of 80℃-180℃. Control the reaction time by controlling the average residence time of the reactants in the batch reactor. Then, transfer the material to industrial alcohol to terminate the reaction, collect the polymerization product, and dry it to obtain the olefin block copolymer.

[0035] The copolymerization catalyst is a [N,P]-type non-metallocene catalyst, and its general structural formula is as follows:

[0036]

[0037] In the formula, R1 is one of 2,6-dimethylphenyl, 2,6-difluorophenyl, and 2,6-diisopropylphenyl; R2 and R3 are both one of 2,4,6-trimethylphenyl and 2,4,6-trifluorophenyl; M represents one of the transition metals Ti, Zr, and Hf; X is one of the halogen atoms Cl and Br; m=4; and 1≤n≤3. This copolymerization catalyst conforming to the general formula was prepared according to the method described in patent publication CN109970890A.

[0038] The second co-catalyst solution is one of triethylaluminum and triisobutylaluminum.

[0039] The molar ratio of the copolymerization catalyst to the oligomerization catalyst in step (1) is (0.1~20):1, the molar ratio of the second co-catalyst to the copolymerization catalyst is (100~800):1, and the molar ratio of ethylene to the copolymerization catalyst introduced into the batch reactor is (1×10⁻⁶). 6 ~1×10 7 ):1; The solvents used in the copolymerization catalyst solution and the second co-catalyst solution are both toluene, and the toluene concentration in the batch reactor is 1~10 mol / L under a single average residence time.

[0040] The specific implementation method is as follows:

[0041] Comparative Example 1

[0042] The reaction steps are as follows: A catalyst solution ([N,P] type non-metallocene catalyst) (using toluene as solvent), a co-catalyst solution of triisobutylaluminum (using toluene as solvent), ethylene gas, 1-hexene, and toluene are continuously added to a batch reactor. The reaction temperature is 100℃, and the average residence time of the reactants in the batch reactor is 10 min. Simultaneously, the catalyst concentration in the batch reactor is controlled at 20 μmol / L, the co-catalyst concentration at 10 mmol / L, the 1-hexene concentration at 0.62 mol / L, and the molar ratio of ethylene to catalyst at 1×10⁻⁶. 6 :1; Then the material is fed into industrial alcohol to terminate the reaction, the polymerization product is collected and dried.

[0043] The catalyst is a conventional [N,P]-type non-metallocene catalyst disclosed in patent publication number CN115594806A, which has not undergone the chromium interference-resistant design of this invention. Its general structural formula is:

[0044]

[0045] In the formula, R1, R2, and R3 are all methyl groups, M is Ni, X is methyl, m=2, n=1. The elemental analysis results of the catalyst are as follows: Ni (31.86%), C (19.56%), H (4.92%), Cl (19.24%), N (7.60%), P (16.81%). 13 C-NMR (400MHz, CDCl3): δ 13.9 (2C, s), 40.1 (1C, s). The co-catalyst was triisobutylaluminum, and the solvent was toluene.

[0046] Comparative Example 2

[0047] Oligopolymerization system: The oligopolymerization catalyst is bis(2-decylthioethyl)amine-CrCl3, the first cocatalyst is methylaluminoxane, and the solvent is hexane; Copolymerization system: The catalyst is a non-metallocene catalyst with a [N,P] type structure as shown in Comparative Example 1, where R1, R2, and R3 are all methyl, M is Ni, X is methyl, m=2, n=1, and the second cocatalyst is triisobutylaluminum.

[0048] The reaction steps are as follows: An oligomerization catalyst solution (using hexane as solvent), a first co-catalyst solution (using hexane as solvent), ethylene gas, and hexane are continuously added to a microchannel reactor to initiate the oligomerization reaction. The microchannel reactor is controlled at 80°C, and the average residence time of the reactants in the microchannel reactor is 30 min. Simultaneously, the concentrations of the oligomerization catalyst and the first co-catalyst in the microchannel reactor are controlled at 20 μmol / L, 2 mmol / L, and the molar ratio of ethylene to the oligomerization catalyst is 1 × 10⁻⁶ at each average residence time. 5 :1; After the reaction, the material is transported to a batch reactor via a series pipeline. A copolymerization catalyst ([N,P] type non-metallocene catalyst) solution (using toluene as solvent), a second co-catalyst solution (using toluene as solvent), ethylene gas, and toluene are continuously added to the batch reactor to carry out the copolymerization reaction. The batch reactor is controlled at 100℃, and the average residence time of the reactants in the batch reactor is 10 min. Simultaneously, the molar ratio of copolymerization catalyst to oligomerization catalyst in the batch reactor is controlled at 1:1, the molar ratio of second co-catalyst to copolymerization catalyst is 500:1, the toluene concentration is 5.8 mol / L, and the molar ratio of ethylene to copolymerization catalyst is 1×10⁻⁶. 6 :1; Then the material is fed into industrial alcohol to terminate the reaction, the polymerization product is collected and dried.

[0049] Comparative Example 3

[0050] The catalyst is a non-metallocene catalyst with the [N,P] type structure shown in Comparative Example 1, where R1 is 2,6-dimethylphenyl, R2 and R3 are both 2,4,6-trimethylphenyl, M is Zr, X is Cl, m=4, n=3. The elemental analysis results of this catalyst are as follows: Zr (7.06%), C (72.50%), H (7.25%), Cl (2.74%), N (3.25%), P (7.19%). 13 C-NMR (400MHz, CDCl3): δ 18.3 (6C, s), 19.4 (12C, s), 20.9 (6C, s), 116.6 (6C, s), 128.6 (3C, s), 128.8 (6C, s), 129.3 (12C, s), 134.8–134.9 (18C, 134.8 (s), 134.9 (s)), 137.7 (6C, s), 141.8 (3C, s). The co-catalyst was triisobutylaluminum, and the solvent was toluene.

[0051] The reaction steps are as follows: A catalyst solution ([N,P] type non-metallocene catalyst) (using toluene as solvent), a co-catalyst solution (using toluene as solvent), ethylene gas, 1-hexene, and toluene are continuously added to a batch reactor. The reaction temperature is 100℃, and the average residence time of the reactants in the batch reactor is 10 min. Simultaneously, the catalyst concentration in the batch reactor is controlled at 20 μmol / L, the co-catalyst concentration at 10 mmol / L, the 1-hexene concentration at 0.62 mol / L, and the molar ratio of ethylene to catalyst at 1×10⁻⁶. 6 :1; Then the material is fed into industrial alcohol to terminate the reaction, the polymerization product is collected and dried.

[0052] Example 1

[0053] Oligopolymerization system: The oligopolymerization catalyst is bis(2-decylthioethyl)amine-CrCl3, the first cocatalyst is methylaluminoxane, and the solvent is hexane. Copolymerization system: The copolymerization catalyst has the following structural formula:

[0054]

[0055] In the formula, R1 is 2,6-dimethylphenyl, R2 and R3 are both 2,4,6-trimethylphenyl, M is Zr, X is Cl, m=4, n=3; the second co-catalyst is triisobutylaluminum.

[0056] The reaction steps are as follows: An oligomerization catalyst solution (using hexane as solvent), a first co-catalyst solution (using hexane as solvent), ethylene gas, and hexane are continuously added to a microchannel reactor to initiate the oligomerization reaction. The microchannel reactor is maintained at 80°C, and the average residence time of the reactants in the microchannel reactor is 30 min. Simultaneously, the concentrations of the oligomerization catalyst and the first co-catalyst in the microchannel reactor are controlled at 20 μmol / L, 2 mmol / L, and the molar ratio of ethylene to the oligomerization catalyst at a single average residence time of 1 × 10⁻⁶. 5 :1; After the reaction, the materials are transported to a batch reactor via a series pipeline. A copolymerization catalyst solution ([N,P] type non-metallocene catalyst) solution (using toluene as solvent), a second co-catalyst solution (using toluene as solvent), ethylene gas, and toluene are continuously added to the batch reactor to carry out the copolymerization reaction. The batch reactor is controlled at 100℃, and the average residence time of the reactants in the batch reactor is 10 min. Simultaneously, the molar ratio of copolymerization catalyst to oligomerization catalyst in the batch reactor is controlled at 1:1, the molar ratio of second co-catalyst to copolymerization catalyst is 500:1, and the molar ratio of ethylene to copolymerization catalyst is 1×10⁻¹⁰ under the single average residence time. 6 1. The toluene concentration is 5.8 mol / L; then the material is transferred to industrial alcohol to terminate the reaction, the polymerization product is collected and dried.

[0057] Example 2

[0058] Oligopolymerization system: The oligopolymerization catalyst is bis(2-dodecylsulfanyl-ethyl)amine-CrCl3, the first co-catalyst is modified methylaluminoxane, and the solvent is heptane. Copolymerization system: The catalyst is a non-metallocene catalyst with the [N,P] type structure shown in Example 1, where R1 is 2,6-difluorophenyl, R2 and R3 are both 2,4,6-trifluorophenyl, M is Ti, X is Cl, m=4, n=2. The elemental analysis results of this catalyst are as follows: Ti (4.99%), C (45.08%), H (1.47%), Cl (7.39%), F (31.69%), N (2.92%), P (6.46%). 13 C-NMR (400MHz, CDCl3): δ 104.7 (8C, s), 111.3 (4C, s), 115.6 (2C, s), 116.6 (4C, s), 141.8 (2C, s), 157.2 (8C, s), 157.9 (4C, s), 161.4 (4C, s). The second co-catalyst was triethylaluminum.

[0059] The reaction steps are as follows: An oligomerization catalyst solution (using heptane as solvent), a first co-catalyst solution (using heptane as solvent), ethylene gas, and heptane are continuously added to a microchannel reactor to initiate the oligomerization reaction. The microchannel reactor is maintained at 60°C, and the average residence time of the reactants in the microchannel reactor is 45 min. Simultaneously, the concentrations of the oligomerization catalyst, the first co-catalyst, and the molar ratio of ethylene to the oligomerization catalyst are controlled at 10 μmol / L, 1 mmol / L, and 1 × 10⁻⁶ molar ratios, respectively, within the single average residence time. 5 1; After the reaction is complete, the materials are transported to a batch reactor via a series pipeline. A copolymerization catalyst ([N,P] type non-metallocene catalyst) solution (using toluene as solvent), a second co-catalyst solution (using toluene as solvent), ethylene gas, and toluene are continuously added to the batch reactor. The batch reactor is adjusted to 120°C, and the average residence time of the reactants in the batch reactor is 15 min. Simultaneously, the molar ratio of copolymerization catalyst to oligomerization catalyst in the batch reactor is controlled at 2:1, the molar ratio of second co-catalyst to copolymerization catalyst is 500:1, and the molar ratio of ethylene to copolymerization catalyst is 1×10⁻⁶ at a single average residence time. 6 1. The toluene concentration is 7.6 mol / L; then the material is transferred to industrial alcohol to terminate the reaction, the polymerization product is collected and dried.

[0060] Example 3

[0061] Oligopolymerization system: The oligopolymerization catalyst is (Ph2PCH2CH2NH2)2CrCl3, the first cocatalyst is methylaluminoxane, and the solvent is octane. Copolymerization system: The copolymerization catalyst is a non-metallocene catalyst with the [N,P] type structure shown in Example 1, where R1 is 2,6-diisopropylphenyl, R2 is 2,4,6-trimethylphenyl, R3 is 2,4,6-trifluorophenyl, M is Hf, X is Br, m=4, n=1. The elemental analysis results of this catalyst are as follows: Hf (20.41%), C (37.07%), H (3.46%), Br (27.40%), F (6.52%), N (1.60%), P (3.54%). 13C-NMR (400MHz, CDCl3): δ 19.4 (2C, s), 20.9 (1C, s), 22.9 (4C, s), 28.2 (2C, s), 104.7 (2C, s), 116.5–116.6 (2C, 116.6(s), 116.6(s)), 123.5 (2C, s), 126.1 (1C, s), 129.3 (2C, s), 134.9 (2C, s), 137.7 (1C, s), 141.8 (1C, s), 146.9 (2C, s), 157.2 (2C, s), 161.4 (1C, s). The second co-catalyst was triisobutylaluminum.

[0062] The reaction steps are as follows: An oligomerization catalyst solution (using octane as solvent), a first co-catalyst solution (using octane as solvent), ethylene gas, and octane are continuously added to a microchannel reactor to initiate the oligomerization reaction. The microchannel reactor is adjusted to 70°C, and the average residence time of the reactants in the microchannel reactor is 50 min. Simultaneously, the concentrations of the oligomerization catalyst, the first co-catalyst, and the molar ratio of ethylene to the oligomerization catalyst are controlled at 15 μmol / L, 3 mmol / L, and 1 × 10⁻⁶ molar ratios, respectively, within the single average residence time. 5 :1; After the reaction, the materials are transported to a batch reactor via a series pipeline. A 20 μmol / L copolymerization catalyst ([N,P] type non-metallocene catalyst) solution (using toluene as solvent), a 10 mmol / L second co-catalyst solution (using toluene as solvent), 20 mol / L ethylene gas, and toluene are continuously added to the batch reactor to carry out the copolymerization reaction. The batch reactor is controlled at 130℃, and the average residence time of the reactants in the batch reactor is 18 min. Simultaneously, the molar ratio of copolymerization catalyst to oligomerization catalyst in the batch reactor is controlled at 4:3, the molar ratio of second co-catalyst to copolymerization catalyst is 500:1, and the molar ratio of ethylene to copolymerization catalyst is 1×10⁻⁶ at a single average residence time. 6 1. The toluene concentration is 6.6 mol / L; then the material is transferred to industrial alcohol to terminate the reaction, the polymerization product is collected and dried.

[0063] Example 4

[0064] Oligopolymerization system: The oligopolymerization catalyst is bis(2-decylthioethyl)amine-CrCl3, the first cocatalyst is modified methylaluminoxane, and the solvent is decane; Copolymerization system: The catalyst is a non-metallocene catalyst with the [N,P] type structure shown in Example 1, where R1 is 2,6-diisopropylphenyl, R2 and R3 are both 2,4,6-trifluorophenyl, M is Zr, X is Br, m=4, n=2. The elemental analysis results of this catalyst are as follows: Zr (7.68%), C (48.54%), H (3.56%), Br (13.45%), F (19.19%), N (2.36%), P (5.22%). 13 C-NMR (400MHz, CDCl3): δ 22.9 (8C, s), 28.2 (4C, s), 104.7 (8C, s), 116.6 (4C, s), 123.5 (4C, s), 126.1 (2C, s), 141.8 (2C, s), 146.9 (4C, s), 157.2 (8C, s), 161.4 (4C, s). The second co-catalyst was triisobutylaluminum.

[0065] The reaction steps are as follows: An oligomerization catalyst solution (using decane as solvent), a first co-catalyst solution (using decane as solvent), ethylene gas, and decane are continuously added to a microchannel reactor to initiate the oligomerization reaction. The microchannel reactor is adjusted to 60°C, and the average residence time of the reactants in the microchannel reactor is 60 min. Simultaneously, the concentrations of the oligomerization catalyst, the first co-catalyst, and the molar ratio of ethylene to the oligomerization catalyst are controlled at 15 μmol / L, 3 mmol / L, and 1 × 10⁻⁶ molar ratios, respectively, within the single average residence time. 5 1; After the reaction, the materials are transported to a batch reactor via a series pipeline. A copolymerization catalyst ([N,P] type non-metallocene catalyst) solution (using toluene as solvent), a second co-catalyst solution (using toluene as solvent), ethylene gas, and toluene are continuously added to the batch reactor. The batch reactor is adjusted to 160°C, and the average residence time of the reactants in the batch reactor is 20 min. Simultaneously, the molar ratio of copolymerization catalyst to oligomerization catalyst in the batch reactor is controlled at 4:3, the molar ratio of second co-catalyst to copolymerization catalyst is 500:1, and the molar ratio of ethylene to copolymerization catalyst is 1×10⁻⁶ at a single average residence time. 6 1. The toluene concentration is 8.1 mol / L; then the material is transferred to industrial alcohol to terminate the reaction, the polymerization product is collected and dried.

[0066] Example 5

[0067] Oligopolymerization system: The oligopolymerization catalyst is bis(2-dodecylsulfanyl-ethyl)amine-CrCl3, the first co-catalyst is methylaluminoxane, and the solvent is hexane; Copolymerization system: The catalyst is a non-metallocene catalyst with the [N,P] type structure shown in Example 1, where R1 is 2,6-dimethylphenyl, R2 is 2,4,6-trimethylphenyl, R3 is 2,4,6-trifluorophenyl, M is Ti, X is Cl, m=4, n=1. The elemental analysis results of this catalyst are as follows: Ti (8.63%), C (49.81%), H (4.00%), Cl (19.18%), F (10.28%), N (2.53%), P (5.58%); 13 C-NMR (400MHz, CDCl3): δ 18.3 (2C, s), 19.4 (2C, s), 20.9 (1C, s), 104.7 (2C, s), 116.5-116.6 (2C, 116.6 (s), 116.6 (s)), 128.6 (1C, s), 128.8 (2C, s), 129.3 (2C, s), 134.8-134.9 (4C, 134.8 (s), 134.9 (s)), 137.7 (1C, s), 141.8 (1C, s), 157.2 (2C, s), 161.4 (1C, s). The second co-catalyst was triethylaluminum.

[0068] The reaction steps are as follows: An oligomerization catalyst solution (using hexane as solvent), a first co-catalyst solution (using hexane as solvent), ethylene gas, and hexane are continuously added to a microchannel reactor to initiate the oligomerization reaction. The microchannel reactor is adjusted to 55°C, and the average residence time of the reactants in the microchannel reactor is 33 min. Simultaneously, the concentrations of the oligomerization catalyst, the first co-catalyst, and the molar ratio of ethylene to the oligomerization catalyst are controlled at 10 μmol / L, 1 mmol / L, and 1 × 10⁻⁶ molar ratios, respectively, within the single average residence time. 5 1; After the reaction, the materials are transported to a batch reactor via a series pipeline. A copolymerization catalyst ([N,P] type non-metallocene catalyst) solution (using toluene as solvent), a second co-catalyst solution (using toluene as solvent), ethylene gas, and toluene are continuously added to the batch reactor. The batch reactor is adjusted to 117°C, and the average residence time of the reactants in the batch reactor is 7 min. Simultaneously, the molar ratio of copolymerization catalyst to oligomerization catalyst in the batch reactor is controlled at 2:1, the molar ratio of second co-catalyst to copolymerization catalyst is 500:1, and the molar ratio of ethylene to copolymerization catalyst is 1×10⁻⁶ at a single average residence time. 61. The toluene concentration is 6.4 mol / L; then the material is transferred to industrial alcohol to terminate the reaction, the polymerization product is collected and dried.

[0069] Example 6

[0070] Oligopolymerization system: The oligopolymerization catalyst is (Ph2PCH2CH2NH2)2CrCl3, the first cocatalyst is modified methylaluminoxane, and the solvent is heptane; Copolymerization system: The catalyst is a non-metallocene catalyst with the [N,P] type structure shown in Example 1, where R1 is 2,6-difluorophenyl, R2 and R3 are both 2,4,6-trimethylphenyl, M is Hf, X is Cl, m=4, n=3. The elemental analysis results of this catalyst are as follows: Hf (12.72%), C (61.63%), H (5.39%), Cl (2.53%), F (8.12%), N (2.99%), P (6.62%); 13 C-NMR (400MHz, CDCl3): δ 19.4 (12C, s), 20.9 (6C, s), 111.3 (6C, s), 115.6 (3C, s), 116.6 (6C, s), 129.3 (12C, s), 134.9 (12C, s), 137.7 (6C, s), 141.8 (3C, s), 157.9 (6C, s). The second co-catalyst was triisobutylaluminum.

[0071] The reaction steps are as follows: An oligomerization catalyst solution (using heptane as solvent), a first co-catalyst solution (using heptane as solvent), ethylene gas, and heptane are continuously added to a microchannel reactor to initiate the oligomerization reaction. The microchannel reactor is adjusted to 65°C, and the average residence time of the reactants in the microchannel reactor is 25 min. The concentrations of the oligomerization catalyst, the first co-catalyst, and the molar ratio of ethylene to the oligomerization catalyst in the microchannel reactor are controlled at 20 μmol / L, 2 mmol / L, and 1 × 10⁻⁶ molar ratios, respectively, under the single average residence time. 5 1. After the reaction is complete, the materials are transported to a batch reactor via a series pipeline. A 20 μmol / L solution of copolymerization catalyst ([N,P] type non-metallocene catalyst) (using toluene as solvent), a 10 mmol / L solution of the second co-catalyst (using toluene as solvent), 20 mol / L ethylene gas, and toluene are continuously added to the batch reactor. The batch reactor is adjusted to 90°C, and the average residence time of the reactants in the batch reactor is 30 min. Simultaneously, the molar ratio of copolymerization catalyst to oligomerization catalyst in the batch reactor is controlled at 1:1, the molar ratio of the second co-catalyst to copolymerization catalyst is 500:1, and the molar ratio of ethylene to copolymerization catalyst is 1×10⁻¹⁰ at a single average residence time. 61. The toluene concentration is 7.2 mol / L; then the material is transferred to industrial alcohol to terminate the reaction, the polymerization product is collected and dried.

[0072] The analytical and testing techniques used in this invention are as follows:

[0073] Microchannel 1-hexene yield test: The mixture sample after oligomerization was collected, and the 1-hexene content in the sample was quantitatively analyzed by gas chromatography (GC). The yield of 1-hexene was calculated based on the amount of ethylene added before the reaction (theoretical amount) and the amount of 1-hexene measured in the sample after the reaction.

[0074] Chromium residue test in batch reactor: The reaction solution was collected from the reactor and the chromium concentration was detected using an inductively coupled plasma mass spectrometer (ICP-MS).

[0075] Polymer weight-average molecular weight and molecular weight distribution testing: The molecular weight and molecular weight distribution of the polymer products were determined using high-temperature gel permeation chromatography (GPC-IR). The instrument was equipped with three PLgel Olexis columns. Analysis procedure: 8 mg of sample was weighed into an 8 mL sample vial and dissolved in 8 mL of 1,2,4-trichlorobenzene solution containing a small amount of BHT antioxidant. The solution was shaken and dissolved at 160 °C for 2 h. After dissolution, the instrument automatically injected the sample at 160 °C and a solvent flow rate of 1.0 mL / min. Polystyrene (PS) was used as a standard to determine the molecular weight.

[0076] Polymer density test: determined according to GB / T 4472-2011.

[0077] Polymer DSC melting peak half-width, melting point, and glass transition point testing: A PerkinElmer DSC8000 instrument was used to characterize the melting temperature (Tm) and glass transition point (Tg) of the polymer product. 4 mg of sample was weighed and placed in a sample dish, sealed, and placed in the sample cell, with the furnace lid closed. The sample mass was entered into the operating software, and a programmed temperature rise was performed from 40 °C to 160 °C at a rate of 10 °C / min, held at this temperature for 10 min to eliminate thermal history. Then, the temperature was lowered to 40 °C at a rate of 10 °C / min, and the crystallization curve of the sample was acquired. Finally, the temperature was raised to 160 °C at a rate of 10 °C / min, and the melting curve of the sample was acquired.

[0078] Polymer tensile strength and elongation at break testing: A universal testing machine was used to perform room temperature tensile tests on the polymer. The procedure was as follows: the polymer was molded into strips at 180℃, quenched at room temperature, and the samples were prepared according to the test method of GB / T 528-2009. The tensile rate was 20 mm / min. The average value of five test results was taken.

[0079] The experimental results comparing the effects of chromium residue in this invention are as follows:

[0080]

[0081] Comparative Example 1 (without microchannel oligomerization segment) and Comparative Example 2 (microchannel oligomerization-copolymerization two-stage linkage) show that when the residual chromium in the oligomerized product transported to the copolymerization vessel reaches 50 ppm, the copolymerization activity of the [N,P]-type non-metallocene catalyst without the anti-chromium interference design of this invention is reduced by >86% in the copolymerization segment. This indicates that the residual chromium inhibits the activity of the [N,P]-type non-metallocene catalyst by occupying active sites and changing the electronic environment. The half-peak width of the DSC melting peak of the copolymer increased from 2.2℃ to 17.5℃, indicating that the block sequence disorder of the product increased significantly, which is caused by the non-selective chain transfer catalyzed by the residual chromium. By comparing Example 3 (without microchannel oligomerization stage) and Example 1 (microchannel oligomerization-copolymerization dual-stage linkage), when the residual chromium in the oligomerization product delivered to the copolymerization reactor reaches 50 ppm, the copolymerization activity loss of the [N,P]-type non-metallocene catalyst designed with anti-chromium interference in this invention in the reactor stage is <6%, and the half-peak width of the DSC melting peak of the copolymer increases from 2.1℃ to 2.2℃, but is still less than 5℃ (the regularity of the product block sequence reaches the OBC level of Dow Chemical). This shows that the present invention, through the ligand steric hindrance design, electronic effect optimization, and synergistic effect of oligomerization and copolymerization process parameters of the [N,P]-type non-metallocene catalyst, can effectively suppress the interference of residual chromium on the copolymerization catalyst, and achieve seamless linkage of oligomerization-copolymerization cascade catalysis under microchannel-reactor dual reactor.

[0082] The test results of the polymerization products in the embodiments of the present invention are summarized as follows:

[0083]

[0084] The polymers obtained in this embodiment of the invention retain a glass transition point of -64 to -51°C while maintaining a melting point of 117 to 125°C. For example, the product of Example 1 has a melting peak of 122°C and a glass transition point of -56°C (see DSC melt curve). Figure 1 The product exhibits significant melting between 75-135 °C and does not contain polyethylene (as the peak melting point of polyethylene is around 135 °C). Its melting peak is contributed by long ethylene segments (from the low comonomer content of the ethylene / 1-hexene "hard segment"). Further analysis using Successive Self-nucleation and Annealing (SSA) further differentiated the original melting peak into multiple smaller peaks. Figure 2The different lengths of the crystallizable segments (long ethylene sequences) corresponding to each small peak indicate a wide distribution of crystallizable long ethylene segment lengths (sequences) in the product. The SSA analysis conditions were as follows: The polymer sample (approximately 5 mg) was heated to 200 °C at a rate of 30 °C / min and held at 200 °C for 5 minutes. The sample was then cooled to 25 °C at a rate of 10 °C / min and held at 25 °C for 2 minutes. Next, the sample was heated to the first self-nucleation temperature Ts (170 °C) at a rate of 10 °C / min and held at this temperature for 5 minutes; then, the sample was cooled to 25 °C at a rate of 10 °C / min and held at 25 °C for 2 minutes. This was marked as the first cycle. Next, the sample was heated to the second nucleation temperature Ts (165 °C) at a rate of 10 °C / min and held at this temperature for 5 minutes. Then, the sample was cooled to 25 °C at a rate of 10 °C / min and held at 25 °C for 2 minutes, marking this as the second cycle. This process was repeated, with each subsequent nucleation temperature decreasing by 5 °C (160 °C, 155 °C, etc.). The final nucleation temperature was set at 60 °C, held at this temperature for 5 minutes, and then cooled to 25 °C at a rate of 10 °C / min and held at 25 °C for 2 minutes. Finally, the sample was heated to 200 °C at a rate of 10 °C / min, and the heating (melting) curves for this process were recorded. Figure 3 The temperature control process during SSA analysis is demonstrated.

[0085] Carbon nuclear magnetic resonance (NMR) spectroscopy 13 C-NMR analysis of the product, by 13 C-NMR spectrum ( Figure 4 The calculated sequence structure distribution is shown in Table 1. It can be seen that the [EEE+EEH] unit contributes to crystallization (melting peak 122℃), while the [EHE] unit constructs a low glass transition point (-56℃). Among them, 13 C-NMR analysis conditions: A deuterated o-dichlorobenzene solution of the polymer (polymer mass fraction 10%) was prepared at 150 °C and stirred for 3–4 h. The pulse angle was 90°, with reverse proton decoupling, a pulse delay time of 3 s, and a collection time of 0.8 s. Approximately 5000 scans were performed for each sample. Detailed carbon atom assignments and compositional calculations of the ethylene / 1-hexene copolymer were performed using the Seger method (MR Seger, GE Maciel. Analytical Chemistry, 2004, 76: 5734).

[0086] Table 1. Composition and sequence distribution of the products from Example 1

[0087]

[0088] In summary, the results demonstrate that the polymer is an ethylene / 1-hexene block polymer (the "soft segment" with high comonomer content provides a low glass transition point, while the "hard segment" with low comonomer content provides a high melting point).

[0089] Compared to Dow Chemical's commercially available olefin block copolymers (OBCs), the relevant parameters range as follows: weight-average molecular weight 100,000~130,000 g / mol, molecular weight distribution 1.90~3.50, and density 0.866~0.887 g / cm³. 3 The olefin block copolymer prepared by this invention has a higher weight-average molecular weight (204,000-292,000 g / mol) and can impart higher tensile strength (8.1-9.7 MPa). The melting point is 118-124℃, the glass transition point is -65℃ to -50℃, the elongation at break is 780-1540%, and the tensile strength is 1.2-7.4 MPa.

[0090] In summary, this invention combines a microchannel reactor with a cascade catalytic process, using a single ethylene feedstock, a seamless connection between a microchannel-stage reactor and a [N,P]-type non-metallocene catalyst to prepare olefin block copolymers. Compared to Dow Chemical's polymerization technology for preparing olefin block copolymers via chain shuttle technology, this method is simpler, easier to control during polymerization, and allows for flexible adjustment of product performance. It eliminates the need for expensive external α-olefins, the simultaneous use of two non-metallocene catalysts, and the introduction of chain shuttles, significantly reducing production costs. By optimizing the ligand steric hindrance design, electronic effects, and synergistic effects of the [N,P]-type non-metallocene catalyst, as well as the coordination of oligomerization and copolymerization process parameters, the interference of the oligomerization catalyst on the copolymerization catalyst is resolved, achieving a seamless connection between oligomerization and copolymerization under a microchannel-stage reactor. The olefin block copolymers prepared by this method exhibit excellent thermal and mechanical properties, and the higher molecular weight contributes a 9%–31% increase in breaking strength compared to Dow Chemical's OBC.

[0091] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock, characterized in that, Includes the following steps: (1) The oligomerization catalyst solution, the first co-catalyst solution, ethylene gas and solvent are continuously added to the microchannel reactor, and the oligomerization reaction is carried out at the preset reaction temperature. The oligomerization reaction time is controlled by controlling the average residence time of the reactants in the microchannel reactor. After the reaction, the materials are transported to the batch reactor through the series pipeline. (2) Add copolymerization catalyst solution, second co-catalyst solution, ethylene gas and toluene continuously to a batch reactor and carry out copolymerization reaction at a preset reaction temperature. Control the reaction time by controlling the average residence time of the reactants in the batch reactor. Then, the material is transported to industrial alcohol to terminate the reaction, the polymerization product is collected and dried to obtain olefin block copolymer.

2. The method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock according to claim 1, characterized in that, The oligomerization catalyst solution is a solution of one of bis(2-decylthioethyl)amine-CrCl3, bis(2-dodecylsulfanyl-ethyl)amine-CrCl3, and (Ph2PCH2CH2NH2)2CrCl3.

3. The method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock according to claim 1, characterized in that, The first cocatalyst solution is a solution of one of methylaluminoxane or modified methylaluminoxane.

4. The method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock according to claim 1, characterized in that, In step (1), the solvent used in the oligomerization catalyst solution and the solvent used in the first co-catalyst solution are the same, namely, one of hexane, heptane, octane and decane.

5. The method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock according to claim 1, characterized in that, The copolymerization catalyst is a [N,P]-type non-metallocene catalyst, and its general structural formula is as follows: In the formula, R1 is one of 2,6-dimethylphenyl, 2,6-difluorophenyl, and 2,6-diisopropylphenyl; R2 and R3 are both one of 2,4,6-trimethylphenyl and 2,4,6-trifluorophenyl; M represents one of the transition metals Ti, Zr, and Hf; X is one of the halogen atoms Cl and Br; m=4; and 1≤n≤3.

6. The method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock according to claim 1, characterized in that, The second cocatalyst solution is one of triethylaluminum and triisobutylaluminum.

7. The method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock according to claim 1, characterized in that, In step (1), under a single average residence time, the molar concentration of the oligomerizing catalyst in the microchannel reactor is 1~25 μmol / L, and the molar ratio of the first co-catalyst to the oligomerizing catalyst is (50~1000):

1. The molar ratio of ethylene to the oligomerizing catalyst introduced into the microchannel reactor is (1×10⁻⁶). 5 ~1.5×10 6 ):

1.

8. The method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock according to claim 1, characterized in that, In step (1), the oligomerization reaction temperature is 40-90℃, and the average residence time of the reactants in the microchannel reactor is 10-60 min.

9. The method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock according to claim 1, characterized in that, In step (2), the molar ratio of the copolymerization catalyst to the oligopolymerization catalyst in step (1) is (0.1~20):1, the molar ratio of the second cocatalyst to the copolymerization catalyst is (100~800):1, and the molar ratio of ethylene to the copolymerization catalyst introduced into the batch reactor is (1×10⁻⁶). 6 ~1×10 7 ):1; The solvents used in the copolymerization catalyst solution and the second co-catalyst solution are both toluene, and the toluene concentration in the batch reactor is 1~10 mol / L under a single average residence time.

10. The method for preparing olefin block copolymers using a continuous series reactor and a single ethylene feedstock according to claim 1, characterized in that, In step (2), the copolymerization reaction temperature is 80℃-180℃, and the average residence time of the reactants in the batch reactor is 5-30 min.

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