A continuous polymerization device and method for olefins in which ethylene participates in copolymerization

Abstract

The present invention provides an olefin continuous polymerization device and method in which ethylene participates in copolymerization, and relates to the technical field of polyolefin synthesis. The device is provided with a gas-liquid mixer and a feed tank connected in sequence before a polymerization reactor, and is used to evenly mix ethylene, a comonomer, and a solvent to obtain an ethylene comonomer solution, which is then injected into the polymerization reactor. Moreover, a mechanical seal agitator with a hollow structure is provided inside the polymerization reactor, so that the ethylene comonomer solution can be evenly released into the polymerization reactor during the stirring process, and then an effective polymerization reaction is achieved with a catalyst and a co-catalyst. The device of the present invention can solve the generation of insoluble substances such as polyethylene from the reaction stage, and provides a new idea for the continuous production of olefin copolymers in which ethylene participates in copolymerization, and has the advantages of simple structure and continuous polymerization through automatic control.

Description

Technical Field

[0001] The invention relates to the technical field of polyolefin synthesis, and in particular to an olefin continuous polymerization device and method in which ethylene participates in copolymerization. Background Art

[0002] Polyolefins usually refer to a class of thermoplastic resins obtained by the polymerization or copolymerization of α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, and certain cycloolefins. Taking polyolefin elastomers (POE) as an example, this type of material has attracted widespread attention due to its excellent mechanical properties, high chemical stability and high processability. In addition, cycloolefin polymers (COP) and cycloolefin copolymers (COC) have great research value due to their high transparency, low birefringence and other properties, and have received widespread attention. At present, cycloolefin copolymers have been widely used in optical lenses / lenses, electronic and electrical components, contact lenses or AR / VR, medicine, food packaging materials and other fields.

[0003] In the early days, this type of material was mainly produced by ring-opening metathesis polymerization (ROMP) using heterogeneous Ziegler-Natta catalysts, but it could not be widely used due to the limitations of the Ziegler-Natta catalysts themselves, such as low reactivity and poor chemical stability. With the emergence of metallocene catalysts and reports on the application of metallocene / methylaluminoxane (MAO) catalysts in stereospecific α-olefin polymerization, this field has ushered in innovation. Due to the high activity of metallocene catalysts and the molecular uniformity of synthetic polymers, cycloolefin polymers have been widely used and developed.

[0004] Mitsui Chemicals of Japan used ethylene and norbornene copolymerization and successfully obtained ethylene-norbornene copolymer with high transparency through metallocene catalyst. Hoechst of Germany used isopropyl (9-fluorenyl) (3-methylcyclopentyl) zirconium dichloride catalyst to copolymerize ethylene and norbornene (50:50) and successfully obtained a cycloolefin copolymer with a glass transition temperature of 145°C. LG Chem used its own developed metallocene catalyst and ethylene and 1-octene or 1-butene as raw materials to complete the production of polyolefin elastomers, with the brand name Lucene. CN105646785A discloses a method for preparing a cycloolefin copolymer, in which an inert organic solvent, a cycloolefin and ethylene are added to a reactor respectively at 40-100°C and a pressure of 1-100 bar; a solution polymerization reaction is carried out under the action of a chain transfer agent and a dual-active center composite catalyst to successfully obtain a cycloolefin polymer.

[0005] Metallocene catalysts have extremely high catalytic activity. Homogeneous metallocene catalysts containing 1g of zirconium can catalyze 10 5kg ethylene polymerization, this is the advantage of metallocene catalysts, but industrial production will also be limited by it. When using ethylene and olefin monomers for copolymerization, ethylene and comonomers are added to the reactor at the same time. The ethylene in the solution cannot be fully dispersed, and a small amount of ethylene still accumulates in the solution. When the polymerization solution enters the reactor, the ethylene gas cannot be fully mixed in the polymer solution. A small amount of aggregated ethylene molecules form ethylene bubbles. After the ethylene molecules further capture the metallocene active center in the polymer solution, due to the extremely high catalytic activity of the metallocene catalyst, ethylene will quickly generate polyethylene in a very short time. At the same time, the insertion time of olefins is extremely fast. The time for each olefin molecule to be inserted in the chain growth process is about 10 -5 s, the molecular weight grows rapidly, and then insoluble matter is quickly generated and accumulated in the reactor and pipelines, causing pipeline blockage and increasing the risk of device shutdown; the accumulated insoluble matter will also increase the difficulty of heat exchange in the device, reduce heat exchange efficiency, and reduce the conversion rate of monomers; at the same time, a small amount of polyethylene remains in the product, which will further affect the mechanical and optical properties of the product and affect the application of the product.

[0006] CN115141299A discloses a process system and method for continuously producing polyolefin elastomers, wherein the polymerization temperature of the process enables the polymer to be discharged in a molten state, and the problem of polyethylene produced during the polymerization process is not mentioned. CN116023572A discloses a high-temperature solution polymerization process for copolymerization of ethylene and α-olefins, wherein a system consisting of a tubular reactor with a static mixer and a kettle reactor is used to carry out high-temperature solution copolymerization of ethylene and α-olefins, but the problem of ethylene phase separation is not solved, and the mixing of polyethylene in the product has little effect on the product quality.

[0007] For the production of POE, the polymerization temperature is high, and the produced polyethylene is melted and mixed into the product, and there is no situation where the polyethylene is insoluble in the solvent and blocks the pipeline; at the same time, the mixing of polyethylene into the polymer produced under this process condition has little effect on the product quality. Therefore, with regard to the problem of uniform distribution of ethylene gas in the continuous olefin polymerization process in which ethylene participates in the copolymerization, which leads to the generation of polyethylene insolubles, the existing disclosed technologies have limitations. How to find a continuous olefin polymerization process in which ethylene participates in the copolymerization with a wider range of applications and solve the problems existing in the above-mentioned process has become one of the urgent problems to be solved by front-line researchers in this field. Summary of the invention

[0008] In the technical scheme of preparing ethylene and olefin copolymers by solution polymerization in the prior art, insoluble substances such as polyethylene will be produced during the reaction process. The insoluble substances will block the system and affect the production safety of the copolymers, and at the same time affect the product quality. In view of the problems existing in the prior art, the present invention provides an olefin continuous polymerization device and method in which ethylene participates in copolymerization. The device is provided with a gas-liquid mixer and a feed tank connected in sequence before the polymerization reactor, which are used to mix ethylene, comonomers, and solvents evenly, and obtain an ethylene comonomer solution and then inject it into the polymerization reactor. Moreover, a mechanical seal agitator with a hollow structure is provided inside the polymerization reactor, so that the ethylene comonomer solution can be evenly released into the polymerization reactor during the stirring process, and then an effective polymerization reaction is achieved with the catalyst and the co-catalyst. The device of the present invention can solve the generation of insoluble substances such as polyethylene from the reaction stage, and provides a new idea for the continuous production of olefin copolymers in which ethylene participates in copolymerization, and has the advantages of simple structure and continuous polymerization through automatic control.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] One of the purposes of the present invention is to provide a continuous polymerization device for olefins in which ethylene participates in copolymerization, comprising:

[0011] A gas-liquid mixer, used to evenly mix ethylene, comonomer and solvent to obtain an ethylene comonomer solution;

[0012] A feed tank, the outlet of the gas-liquid mixer is connected to the inlet of the feed tank;

[0013] A polymerization reactor for achieving full-tank reaction; a mechanically sealed agitator is arranged inside the polymerization reactor, the mechanically sealed agitator comprises a stirring shaft and stirring blades, hollow structures for mutual circulation are provided inside the stirring shaft and the stirring blades, a gas-liquid mixture inlet is provided at the portion of the stirring shaft located outside the polymerization reactor, and at least one gas-liquid mixture outlet is provided on the stirring blades; the outlet of the feed tank is connected to the gas-liquid mixture inlet, so that the ethylene comonomer solution passes through the hollow structure and is released from the gas-liquid mixture outlet into the polymerization reactor; the polymerization reactor is also provided with a catalyst inlet for supplying catalyst and co-catalyst; the polymerization reactor is also provided with a reaction product outlet.

[0014] The present invention aims at the problems of the prior art and provides an olefin continuous polymerization device in which ethylene participates in copolymerization. In the initial stage of the reaction, a gas-liquid mixer is used to make ethylene, a comonomer and a solvent evenly mixed and close to a liquid homogeneous phase. In addition, a feed tank is used to further ensure the liquid phase feeding of the ethylene comonomer, thereby reducing the production of polyethylene in the reaction stage, solving the problem that polyethylene insolubles are produced due to uneven mixing in the olefin polymerization process, thereby affecting production safety, and achieving safe operation of the polymerization device and stable production of products.

[0015] As a preferred technical solution of the present invention, the polymerization reactor is also provided with a comonomer control inlet for supplying additional comonomers and solvents to achieve control; the catalyst inlet coincides with the comonomer control inlet, that is, the pipeline for supplying catalyst and co-catalyst is combined with the pipeline for supplying additional comonomers and solvents, and then enters the polymerization reactor through the catalyst inlet; the catalyst inlet is located at the bottom of the polymerization reactor, and the reaction product outlet is located at the top of the polymerization reactor.

[0016] As a preferred technical solution of the present invention, the gas-liquid mixer is a static mixer with a gas-liquid distribution plate, so that the gas and liquid materials are fully mixed and dissolved in the gas-liquid mixing chamber.

[0017] Preferably, the gas-liquid mixer includes any one of a suction type gas-liquid distributor, an overflow type gas-liquid distributor or a jet type gas-liquid distributor, or a combination of at least two of them.

[0018] As a preferred technical solution of the present invention, the feed tank is provided with a liquid level meter.

[0019] Preferably, a pressure sensor and a pressure regulating valve are provided on the top of the feed tank, and the two are connected by signals, and the pressure in the feed tank is kept constant by setting the pressure of the pressure regulating valve;

[0020] The inlet of the feed tank is opened on the side, and the outlet of the feed tank is opened at the bottom;

[0021] A feed pump is provided between the outlet of the feed tank and the inlet of the gas-liquid mixture. The evenly mixed ethylene comonomer solution in the feed tank is pressed into the mechanical seal agitator for flushing through the feed pump. Through the design of the agitator, the flushing liquid is evenly introduced into the six stirring blades through the stirring shaft and released from the stirring blades into the polymerization reactor, so as to evenly disperse the fully mixed ethylene comonomer solution into the polymerization reactor in this way.

[0022] As a preferred technical solution of the present invention, the polymerization reactor is provided with a temperature control system with a temperature probe monitoring, and the reaction temperature of the polymerization device is regulated and controlled by the temperature control system, and at the same time has an emergency cooling function;

[0023] A pressure probe is provided on the top of the polymerization reactor, and a regulating valve is provided on the reaction product pipeline connected to the reaction product outlet. The pressure probe is connected to the regulating valve for signal connection, and the pressure in the polymerization reactor is controlled to be constant through the regulating valve discharge.

[0024] A second object of the present invention is to provide a method for continuous polymerization of olefins with the participation of ethylene in copolymerization, using the device for continuous polymerization of olefins with the participation of ethylene in copolymerization as described in the first object, the method comprising:

[0025] Ethylene, comonomer and solvent are respectively introduced into the gas-liquid mixer for mixing. The obtained ethylene comonomer solution passes through the feed tank, and then is uniformly released into the polymerization reactor from the gas-liquid mixture inlet of the mechanically sealed agitator, through the hollow structure, and from the gas-liquid mixture outlet opened by the stirring blades of the mechanically sealed agitator; at the same time, the catalyst and the co-catalyst enter through the catalyst inlet of the polymerization reactor to carry out continuous polymerization of olefins and realize full reactor reaction; the obtained reaction product is collected through the reaction product outlet.

[0026] The present invention adopts a solution polymerization method, wherein the proportion of comonomer, ethylene and solvent is controlled to enter a gas-liquid mixer so that ethylene, comonomer and solvent are fully mixed, dissolved and absorbed to form a nearly liquid homogeneous phase which enters a feed tank, and enters a polymerization reactor in the form of a liquid phase through the bottom of the feed tank; the catalyst and the co-catalyst are directly metered into the reactor, the comonomer and the solvent can enter the polymerization reactor through a regulating pipeline for continuous polymerization, the polymerization reactor is full for reaction, and the material is discharged through a regulating valve in conjunction with the pressure in the reactor.

[0027] As a preferred technical solution of the present invention, the structural formula of the comonomer is structural formula A or structural formula B;

[0028]

[0029] Structural formula A Structural formula B

[0030] Wherein, n, m, z are positive integers, X is a halogen atom, R1 is a hydrocarbon group, R2, R3, R4, R5, R6, R7, R8 independently include hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, amino groups, cyano groups, thiol groups, hydroxyl groups, carboxyl groups, ester groups, carbonate groups and atoms or atomic groups that can replace the above groups, or R4 and R5 can be connected to form a group with a cyclic structure.

[0031] Preferably, the comonomer comprises at least one of tetracyclododecene, 1-octene, 1-decene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and norbornene and derivatives thereof. The comonomer is preferably a cycloolefin.

[0032] As a preferred technical solution of the present invention, the solvent is a hydrocarbon solvent, which can dissolve and dilute the co-monomer, catalyst and co-catalyst.

[0033] Preferably, the solvent comprises at least one of toluene, xylene, n-hexane, cyclohexane, n-heptane or octane, preferably toluene.

[0034] The catalyst is a metallocene and non-metallocene compound including titanium, vanadium, zirconium, hafnium or tantalum, and the catalyst includes Me2(Ind)2TiCl2, EtCp(Ind)TiCl2, Ph2Cp(Ind)TiCl2, Me2Si(Ind)2TiCl2, VO(Cl)3, VO(OCH3)Cl2, VO(OCH3)2Cl, VO(OCH3)3, VO(OC2H5)Cl2, VO(OC2H5)2Cl, VO(OC2H5)3, V At least one of O(O-iso-C3H7)Cl2, Ph2Cp(Ind)ZrCl2, Me2Si(Ind)2ZrCl2, (Ind)2ZrCl2, Me2SiCp2ZrCl2, EtCp(Ind)ZrCl2, Me2(Ind)2ZrCl2, Me2Si(Ind)2HfCl2, Et(Ind)2HfCl2, Me2SiCp2HfCl2, TaO(Cl)3 or TaO(OC2H5)Cl2.

[0035] Preferably, the cocatalyst includes at least one of trialkylaluminum (such as trimethylaluminum, triethylaluminum, tributylaluminum), alkylaluminoxane (such as methylaluminumoxane, ethylaluminumoxane), partially alkoxylated and halogenated alkylaluminum (such as ethylaluminum ethoxychloride, butylaluminum butoxychloride, ethylaluminum ethoxybromide), partially hydrogenated alkoxy (such as diethylaluminum hydride, dibutylaluminum hydride, alkylaluminum dihydride), partially halogenated alkylaluminum halide (such as diethylaluminum monochloride, ethylaluminum dichloride, sesquiethylaluminum chloride), and organic boron compound (such as boroxine, triethylborane, triphenylcarbonium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate).

[0036] Preferably, the mass ratio of the catalyst to the co-catalyst is 1:(50-5000), for example, 1:50, 1:100, 1:300, 1:500, 1:800, 1:1000, 1:3000 or 1:5000, etc.

[0037] As a preferred technical solution of the present invention, the pressure of the feed tank (3) is controlled to be 10-100 bar, for example, 10 bar, 20 bar, 30 bar, 40 bar, 50 bar, 60 bar, 70 bar, 80 bar, 90 bar or 100 bar.

[0038] As a preferred technical solution of the present invention, the molar ratio of the comonomer to ethylene is 0.3-5, for example, 0.3, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5, etc., the Tg of the reaction product is 70-200°C, for example, 70°C, 80°C, 100°C, 110°C, 130°C, 150°C, 170°C, 180°C or 200°C, etc., and the polymerization temperature in the polymerization reactor (1) is controlled to be 5-80°C, for example, 5°C, 10 The polymerization temperature is 0.1-0.20 °C, 0.20 °C, 0.30 °C, 0.40 °C, 0.50 °C, 0.60 °C, 0.70 °C or 0.80 °C, etc., the polymerization reaction pressure is 10-60 bar, such as 10 bar, 15 bar, 20 bar, 25 bar, 30 bar, 40 bar, 50 bar or 60 bar, etc., and the residence time is 5-120 min, such as 5 min, 10 min, 30 min, 50 min, 70 min, 90 min, 100 min or 120 min, etc.

[0039] The glass transition temperature (Tg) of the polymer formed by solution polymerization of ethylene and comonomer is closely related to the molar ratio of each polymer structural unit in the polymer molecule. However, in the past, in the process of copolymerization of comonomer and ethylene, part of ethylene will self-polymerize to form polyethylene insolubles, which will affect the ratio between comonomer and ethylene, causing the glass transition temperature of the polymer to fluctuate. At the same time, the generated polyethylene insolubles will also be mixed in the polymer, further affecting the optical properties of the product. The olefin continuous polymerization method with ethylene participating in the copolymerization of the present invention adopts an improved olefin continuous polymerization device with ethylene participating in the copolymerization, effectively avoiding the generation of polyethylene insolubles, and further regulating the comonomer ethylene ratio in the comonomer ethylene solution by temperature and pressure, thereby completing the production of polymers with a specific glass transition temperature. For example, when the molar ratio of ethylene in the copolymer is 75%, the Tg of the generated copolymer is about 50°C, and when the molar ratio of ethylene in the copolymer is 35%, the Tg of the generated copolymer is about 200°C; that is, when cycloolefin monomers are used to copolymerize ethylene, the higher the ratio of cycloolefin monomers in the polymer, the higher the Tg of the synthesized polymer. In order to obtain the designed polymer without producing polyethylene, the process conditions shown in Table 1 below need to be defined.

[0040] Table 1

[0041]

[0042] Note: The preferred molar numbers of comonomer and ethylene in the table are the molar parts of comonomer and ethylene in 1L toluene solution.

[0043] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0044] In view of the problems of the prior art, the present invention provides an olefin continuous polymerization device in which ethylene participates in the copolymerization, which solves the generation of insoluble matter in the solution copolymerization process in which ethylene participates in the reaction stage, solves the influence of the insoluble matter on the device, ensures the smooth operation of the device, and improves the quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a schematic diagram of an olefin continuous polymerization device in which ethylene participates in copolymerization according to Example 1 of the present invention;

[0046] Figure 2 is a schematic structural diagram of a mechanical seal agitator in Example 1 of the present invention;

[0047] In the figure: 1-polymerization reactor, 2-gas-liquid mixer, 3-feeding tank, 4-feeding pump, 5-mechanical seal agitator, 6-temperature control system, 7-regulating valve, 8-pressure regulating valve, 9-gas-liquid mixture inlet, 10-hollow structure, 11-gas-liquid mixture outlet;

[0048] Figure 3 It is the DSC result of the white insoluble matter obtained in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0049] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0050] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0051] Example 1

[0052] This embodiment provides a continuous polymerization device for olefins in which ethylene participates in copolymerization, such as Figure 1 As shown, including:

[0053] A gas-liquid mixer 2 is used to evenly mix ethylene, comonomer and solvent to obtain an ethylene comonomer solution;

[0054] A feed tank 3, the outlet of the gas-liquid mixer 2 is connected to the inlet of the feed tank 3;

[0055] A polymerization reactor 1 is used to achieve full reactor reaction; a mechanical seal agitator 5 is provided inside the polymerization reactor 1; Figure 2As shown, the mechanical seal agitator 5 includes a stirring shaft and a stirring blade; a hollow structure 10 for mutual circulation is provided inside the stirring shaft and the stirring blade, a gas-liquid mixture inlet 9 is provided at the portion of the stirring shaft located outside the polymerization reactor 1, and at least one gas-liquid mixture outlet 11 is provided on the stirring blade; the outlet of the feed tank 3 is connected to the gas-liquid mixture inlet 9, so that the ethylene comonomer solution passes through the hollow structure and is released from the gas-liquid mixture outlet 11 into the polymerization reactor 1; the polymerization reactor 1 is also provided with a catalyst inlet for supplying catalyst and co-catalyst; the polymerization reactor 1 is also provided with a reaction product outlet;

[0056] The polymerization reactor 1 is also provided with a comonomer control inlet for supplying additional comonomers and solvents to achieve control, and the catalyst inlet coincides with the comonomer control inlet;

[0057] The catalyst inlet is located at the bottom of the polymerization reactor 1, and the reaction product outlet is located at the top of the polymerization reactor 1;

[0058] The gas-liquid mixer 2 is a static mixer with a gas-liquid distribution plate, so that the gas and liquid materials are fully mixed and dissolved in the gas-liquid mixing chamber;

[0059] The feed tank 3 is provided with a liquid level gauge; a pressure sensor and a pressure regulating valve 8 are provided on the top of the feed tank 3, and the two realize signal connection; the inlet of the feed tank 3 is opened on the side, and the outlet of the feed tank 3 is opened at the bottom; a feed pump 4 is provided between the outlet of the feed tank 3 and the gas-liquid mixture inlet 9;

[0060] The polymerization reactor 1 is provided with a temperature control system 6 with a temperature probe for monitoring; a pressure probe is provided on the top of the polymerization reactor 1, and a regulating valve 7 is provided on the reaction product pipeline connected to the reaction product outlet, and the pressure probe is connected to the regulating valve 7 for signal connection.

[0061] This embodiment also provides a method for continuous polymerization of olefins with ethylene participating in copolymerization, using the above-mentioned continuous polymerization device for olefins with ethylene participating in copolymerization, the effective volume of the polymerization reactor 1 is 1L, and continuous solution polymerization of ethylene and tetracyclododecene is carried out; the method comprises:

[0062] Ethylene, tetracyclododecene, and toluene are respectively mixed in the gas-liquid mixer 2 to form a nearly homogeneous ethylene comonomer solution, which is then stored in the feed tank 3. The feed pump 4 is used to uniformly release the mixture from the gas-liquid mixture inlet 9 of the mechanically sealed agitator 5, through the hollow structure 10, and from the gas-liquid mixture outlet 11 opened by the stirring blades of the mechanically sealed agitator 5 into the polymerization reactor 1.

[0063] The polymerization temperature in the polymerization reactor 1 is controlled to be 50° C., and the polymerization pressure is 20 bar; the main catalyst used is Me2(CP)(Flu)ZrCl2, which is prepared into a solution with toluene, and 0.64 μmol is fed per unit residence time; the co-catalyst used is methylaluminoxane, which is prepared into a solution with toluene, and 1.28 mmol is fed per unit residence time; the co-monomer used is tetracyclododecene, and 1.6 mol is fed per unit residence time, 7.2 mol is fed per unit residence time of solvent toluene, and 0.4 mol is fed per unit residence time of ethylene; the solution of the catalyst, the co-catalyst, the ethylene and the co-monomer is supplied to the polymerization reactor 1 through the above-mentioned two catalyst pipelines and a mixed solution pipeline for continuous polymerization;

[0064] The material was automatically discharged by adjusting the pressure in the polymerization reactor. The residence time in this embodiment was 60 min. At steady state, 1 L of the polymer solution was taken and post-treated to obtain 86.5 g of ethylene-tetracyclododecene copolymer with a Tg of 187.4° C. No white precipitate was found in the polymer solution.

[0065] Example 2

[0066] The present embodiment provides a method for continuous polymerization of olefins with ethylene participating in copolymerization. Compared with Example 1, the differences are: the reaction polymerization temperature is not 40°C, the polymerization pressure is 20 bar; the main catalyst used is EtCp(Ind)ZrCl2, which is prepared into a solution with toluene, and 0.64 μmol is fed per unit residence time; the co-catalyst used is methylaluminoxane, and 1.28 mmol is fed per unit residence time; the co-monomer used is tetracyclododecene, and 1.1 mol is fed per unit residence time; the solvent toluene is fed per unit residence time of 7.9 mol, and ethylene is fed per unit residence time of 0.6 mol. The other conditions remain unchanged, and continuous solution polymerization of ethylene and tetracyclododecene is carried out in a polymerization reactor.

[0067] The material was automatically discharged by adjusting the pressure in the polymerization reactor. In this embodiment, 1 L of the polymer solution was taken at steady state, and 94.8 g of ethylene-tetracyclododecene copolymer with a Tg of 158.3° C. was obtained through post-treatment. No white precipitate was found in the polymer solution.

[0068] Example 3

[0069] The present embodiment provides a method for continuous polymerization of olefins with ethylene participating in copolymerization. Compared with Example 1, the differences are: the reaction polymerization temperature is 40°C, the polymerization pressure is 30 bar; the main catalyst used is EtCp(Ind)ZrCl2, which is prepared into a solution with toluene, and 0.64 μmol is fed per unit residence time; the co-catalyst used is ethylaluminoxane, and 2.56 mmol is fed per unit residence time; the co-monomer used is norbornene, and 1.6 mol is fed per unit residence time; 7.8 mol of solvent toluene is fed per unit residence time, and 0.8 mol of ethylene is fed per unit residence time. The other conditions remain unchanged, and continuous solution polymerization of ethylene and norbornene is carried out in a polymerization reactor.

[0070] The material was automatically discharged by adjusting the pressure in the polymerization reactor. In this embodiment, 1 L of the polymer solution was taken at steady state, and 84.7 g of ethylene-norbornene copolymer with a Tg of 141.5° C. was obtained through post-treatment. No white precipitate was found in the polymer solution.

[0071] Example 4

[0072] The present embodiment provides a method for continuous polymerization of olefins with ethylene participating in copolymerization. Compared with Example 1, the difference is that: the reaction polymerization temperature is 50°C, the polymerization pressure is 40 bar; the comonomer is tetracyclododecene, 1.8 mol is fed per unit residence time, 6.9 mol of solvent toluene is fed per unit residence time, and 1.0 mol of ethylene is fed per unit residence time. The other conditions remain unchanged, and continuous solution polymerization of ethylene and tetracyclododecene is carried out in a polymerization reactor.

[0073] The material was automatically discharged by adjusting the pressure in the polymerization reactor. In this embodiment, 1 L of the polymer solution was taken out at steady state and 132.5 g of ethylene-tetracyclododecene copolymer with a Tg of 124.6° C. was obtained by post-treatment. No white precipitate was found in the polymer solution.

[0074] Example 5

[0075] The present embodiment provides a method for continuous polymerization of olefins with ethylene participating in copolymerization. Compared with Example 1, the difference is that: the reaction polymerization temperature is 30°C, the polymerization pressure is 40 bar; the comonomer is tetracyclododecene, 1.3 mol is fed per unit residence time, 7.6 mol of solvent toluene is fed per unit residence time, and 1.2 mol of ethylene is fed per unit residence time. The other conditions remain unchanged, and continuous solution polymerization of ethylene and tetracyclododecene is carried out in a polymerization reactor.

[0076] The material was automatically discharged by adjusting the pressure in the polymerization reactor. In this embodiment, 1 L of the polymer solution was taken out at steady state and 105.8 g of ethylene-tetracyclododecene copolymer with a Tg of 109.9° C. was obtained by post-treatment. No white precipitate was found in the polymer solution.

[0077] Example 6

[0078] The present embodiment provides a method for continuous polymerization of olefins with ethylene participating in copolymerization. Compared with Example 1, the difference is that: the reaction polymerization temperature is 60°C, the polymerization pressure is 50 bar; the comonomer is norbornene, 1.0 mol is fed per unit residence time, 8.4 mol of solvent toluene is fed per unit time, and 2.9 mol of ethylene is fed per unit residence time. The other conditions remain unchanged, and continuous solution polymerization of ethylene and norbornene is carried out in a polymerization reactor.

[0079] The material was automatically discharged by adjusting the pressure in the polymerization reactor. In this embodiment, 1 L of the polymer solution was taken at steady state and subjected to post-treatment to obtain 84.7 g of ethylene-norbornene copolymer with a Tg of 73.5° C. No white precipitate was found in the polymer solution.

[0080] Example 7

[0081] This embodiment provides a method for continuous polymerization of olefins with ethylene participating in copolymerization. Compared with Example 2, the difference is that: the reaction polymerization temperature is 60°C, the polymerization pressure is 50 bar; the comonomer is norbornene, 1.0 mol is fed per unit residence time, 8.4 mol of solvent toluene is fed per unit time, and 1.6 mol of ethylene is fed per unit residence time. The other conditions remain unchanged, and continuous solution polymerization of ethylene and norbornene is carried out in a polymerization reactor.

[0082] The material was automatically discharged by adjusting the pressure in the polymerization reactor. In this embodiment, 1 L of the polymer solution was taken at steady state and 83.4 g of ethylene-norbornene copolymer with a Tg of 88.9° C. was obtained by post-treatment. No white precipitate was found in the polymer solution.

[0083] Example 8

[0084] The present embodiment provides a method for continuous polymerization of olefins with ethylene participating in copolymerization. Compared with Example 1, the difference is that: the reaction polymerization temperature is 40°C, the polymerization pressure is 20 bar; the comonomer is tetracyclododecene, 1.8 mol is fed per unit residence time, 6.9 mol of solvent toluene is fed per unit time, and 0.3 mol of ethylene is fed per unit residence time. The other conditions remain unchanged, and continuous solution polymerization of ethylene and norbornene is carried out in a polymerization reactor.

[0085] The material was automatically discharged by adjusting the pressure in the polymerization reactor. In this embodiment, 1 L of the polymer solution was taken out at steady state and 29.3 g of ethylene-norbornene copolymer with a Tg of 207.4° C. was obtained by post-treatment. No white precipitate was found in the polymer solution.

[0086] When the molar ratio of the comonomer to ethylene exceeds 5, the polymerization ratio of the comonomer is reduced due to its own steric hindrance, so the yield of the obtained polymer is relatively small.

[0087] Comparative Example 1

[0088] This comparative example provides an olefin continuous polymerization device in which ethylene participates in copolymerization. Compared with the device described in Example 1, the only difference is that the gas-liquid mixer 2 and the feed tank 3 are completely omitted.

[0089] This comparative example also provides a method for continuous polymerization of olefins with the participation of ethylene copolymerization, using the aforementioned continuous polymerization device for olefins with the participation of ethylene copolymerization, since the gas-liquid mixer 2 and the feed tank 3 are completely omitted, ethylene, comonomers and solvent are not further mixed, but directly enter the polymerization reactor 1 for reaction, and the other conditions are the same as those in Example 1.

[0090] The material was automatically discharged by adjusting the pressure in the polymerization reactor. In this comparative example, 1L of polymer solution was taken at steady state and centrifuged to obtain 2.7g of white insoluble matter. The polymer solution was treated after polymerization to obtain 83.5g of ethylene-tetracyclododecene copolymer with Tg of 197.3℃, and the insoluble product reached 3.1%.

[0091] The white insoluble matter was sampled and characterized by DSC. The results were as follows Figure 3 As shown, it can be seen that the thermal enthalpy value of the white insoluble matter is consistent with the result of polyethylene, that is, the white insoluble matter produced is polyethylene, indicating that the generation of white insoluble matter can be effectively reduced by the gas-liquid mixer.

[0092] Comparative Example 2

[0093] This comparative example provides a method for continuous polymerization of olefins with the participation of ethylene copolymerization. The continuous polymerization device for olefins with the participation of ethylene copolymerization described in comparative example 1 is used. Since the gas-liquid mixer 2 and the feed tank 3 are completely omitted, ethylene, comonomer and solvent are not further mixed, but directly enter the polymerization reactor 1 for reaction. The other conditions are the same as those in Example 2.

[0094] The material was automatically discharged by adjusting the pressure in the polymerization reactor. In this comparative example, 1L of polymer solution was taken at a steady state and centrifuged to obtain 5.3g of white insoluble matter. The polymer solution was treated after polymerization to obtain 74.5g of ethylene-norbornene copolymer with a Tg of 153.8°C, and the insoluble product reached 6.6%.

[0095] Comparative Example 3

[0096] This comparative example provides an olefin continuous polymerization device in which ethylene participates in copolymerization. Compared with the device described in Example 1, the only difference is that the feed tank 3 is completely omitted, that is, the outlet of the gas-liquid mixer 2 is directly connected to the gas-liquid mixture inlet 9.

[0097] This comparative example also provides a method for continuous polymerization of olefins with the participation of ethylene copolymerization, using the aforementioned continuous polymerization device for olefins with the participation of ethylene copolymerization. Since the ethylene comonomer solution obtained by mixing in the gas-liquid mixer 2 does not pass through the feed tank 3, but directly enters the polymerization reactor 1 for reaction, the other conditions are the same as those in Example 1.

[0098] The material was automatically discharged by adjusting the pressure in the polymerization reactor. In this comparative example, 1L of polymer solution was taken at steady state and centrifuged to obtain 1.1g of white insoluble matter. The polymer solution was treated after polymerization to obtain 85.6g of ethylene-tetracyclododecene copolymer with Tg of 192.5°C, and the insoluble product reached 1.3%.

[0099] Comparative Example 4

[0100] This comparative example provides an olefin continuous polymerization device in which ethylene participates in copolymerization. Compared with the device described in Example 1, the only difference is that the pipeline of the raw material ethylene is no longer connected to the gas-liquid mixer 2, but is directly connected to the gas-liquid mixture inlet 9.

[0101] This comparative example also provides a method for continuous polymerization of olefins with the participation of ethylene copolymerization. The above-mentioned continuous polymerization device for olefins with the participation of ethylene copolymerization is used. Since ethylene directly enters the reactor without passing through the gas-liquid mixer, 3.2 mol of ethylene is fed per unit residence time, which is greater than the designed ethylene feed ratio. The other conditions are the same as those in Example 1, and continuous solution polymerization of ethylene-tetracyclododecene is carried out in the polymerization reactor.

[0102] The material was automatically discharged by adjusting the pressure inside the polymerization reactor. During the polymerization process, a large amount of white insoluble matter was found to be blocking the pipeline and the device was shut down.

[0103] In summary, the device is provided with a gas-liquid mixer and a feed tank connected in sequence before the polymerization reactor, which are used to mix ethylene, comonomers, and solvents evenly, obtain an ethylene comonomer solution, and then inject it into the polymerization reactor. Moreover, a mechanical seal agitator with a hollow structure is provided inside the polymerization reactor, so that the ethylene comonomer solution can be evenly released into the polymerization reactor during the stirring process, and then achieve an effective polymerization reaction with the catalyst and the co-catalyst. The device of the present invention can solve the generation of insoluble substances such as polyethylene from the reaction stage, and provides a new idea for the continuous production of olefin copolymers in which ethylene participates in copolymerization, and has the advantages of simple structure and continuous polymerization through automatic control.

[0104] The present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0105] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0106] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0107] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A continuous polymerization device for olefins in which ethylene participates in copolymerization, characterized in that: Included are: The gas-liquid mixer (2) is used to evenly mix ethylene, comonomer and solvent to obtain an ethylene comonomer solution; the gas-liquid mixer (2) is a static mixer with a gas-liquid distribution plate, so that the gas and liquid materials are fully mixed and dissolved in the gas-liquid mixing chamber; A feed tank (3), wherein the outlet of the gas-liquid mixer (2) is connected to the inlet of the feed tank (3); a pressure sensor and a pressure regulating valve (8) are provided on the top of the feed tank (3), and the two are signal-connected; the inlet of the feed tank (3) is opened on the side, and the outlet of the feed tank (3) is opened at the bottom; A polymerization reactor (1) is used to achieve a full reactor reaction; a mechanically sealed agitator (5) is provided inside the polymerization reactor (1), the mechanically sealed agitator (5) comprises a stirring shaft and stirring blades, the stirring shaft and the stirring blades are provided with hollow structures for mutual circulation, a gas-liquid mixture inlet is provided at the portion of the stirring shaft located outside the polymerization reactor (1), and at least one gas-liquid mixture outlet is provided at the stirring blades; the outlet of the feed tank (3) is connected to the gas-liquid mixture inlet, so that the ethylene comonomer solution passes through the hollow structure and is released from the gas-liquid mixture outlet into the polymerization reactor (1); the polymerization reactor (1) is also provided with a catalyst inlet for supplying a catalyst and a co-catalyst; the polymerization reactor (1) is also provided with a reaction product outlet; The polymerization reactor (1) is further provided with a comonomer control inlet for supplying additional comonomer and solvent for control; the catalyst inlet coincides with the comonomer control inlet; the catalyst inlet is located at the bottom of the polymerization reactor (1), and the reaction product outlet is located at the top of the polymerization reactor (1); The structural formula of the comonomer is structural formula A or structural formula B; ； Structural formula A Structural formula B Wherein, n, m, z are positive integers, X is a halogen atom, R1 is a hydrocarbon group, R2, R3, R4, R5, R6, R7, R8 independently include hydrogen atoms, halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, amino groups, cyano groups, thiol groups, hydroxyl groups, carboxyl groups, ester groups, carbonate groups, and atoms or atomic groups that can replace the above groups, or R4 and R5 can be connected to form a group having a cyclic structure; The pressure of the feed tank (3) is controlled to be 10-100 bar; the molar ratio of the comonomer to ethylene is 0.3-5, the Tg of the reaction product is 70-200° C., the polymerization temperature in the polymerization reactor (1) is controlled to be 5-80° C., the polymerization pressure is controlled to be 10-60 bar, and the residence time is controlled to be 5-120 min.

2. The olefin continuous polymerization device in which ethylene participates in copolymerization according to claim 1, characterized in that: A feed pump (4) is provided between the outlet of the feed tank (3) and the inlet of the gas-liquid mixture.

3. The olefin continuous polymerization device in which ethylene participates in copolymerization according to claim 1 is characterized in that: The polymerization reactor (1) is provided with a temperature control system (6) with temperature probe monitoring; A pressure probe is provided on the top of the polymerization reactor (1), and a regulating valve (7) is provided on a reaction product pipeline connected to the reaction product outlet, and a signal connection is achieved between the pressure probe and the regulating valve (7).

4. A method for continuous polymerization of olefins with ethylene participating in copolymerization, characterized in that: The olefin continuous polymerization device in which ethylene participates in copolymerization according to any one of claims 1 to 3 is used, and the method comprises: Ethylene, comonomer and solvent are respectively introduced into the gas-liquid mixer (2) for mixing. The obtained ethylene comonomer solution passes through the feed tank (3), and then is uniformly released into the polymerization reactor (1) from the gas-liquid mixture inlet of the mechanical seal stirrer (5), through the hollow structure, and from the gas-liquid mixture outlet opened by the stirring blades of the mechanical seal stirrer (5). At the same time, the catalyst and the co-catalyst enter through the catalyst inlet of the polymerization reactor (1) to carry out a continuous polymerization reaction of olefins and realize a full reactor reaction. The obtained reaction product is collected through the reaction product outlet.

5. The method for continuous polymerization of olefins in which ethylene participates in copolymerization according to claim 4, characterized in that: The solvent is a hydrocarbon solvent; The catalyst is a metallocene and non-metallocene compound including titanium, vanadium, zirconium, hafnium or tantalum; the mass ratio of the catalyst to the co-catalyst is 1:(50-5000).

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