Process for the direct preparation of cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor

Abstract

The application belongs to the technical field of organic compound synthesis and the field of polymer preparation, and discloses a method for directly preparing a cycloolefin copolymer from dicyclopentadiene and ethylene based on a continuous flow reactor; the continuous flow reactor is used to efficiently prepare norbornene and derivatives thereof from ethylene and dicyclopentadiene, and then the norbornene and derivatives thereof are used to prepare a cycloolefin copolymer from excessive ethylene. The application uses dicyclopentadiene and ethylene as raw materials, realizes a continuous process from the synthesis of a cycloolefin monomer to the preparation of a cycloolefin copolymer, and the cycloolefin monomer does not need to be separated and stored and can directly participate in the polymerization reaction, so that the original complicated process is effectively simplified, energy consumption is reduced, the catalyst in the polymerization stage is not easy to be deactivated even at high temperature, the catalytic efficiency is high, and a high polymer yield can be obtained in a very short time.

Description

Technical Field

[0001] This invention belongs to the fields of organic compound synthesis technology and polymer preparation technology, specifically relating to a method for directly preparing cyclic olefin copolymers using dicyclopentadiene through a series continuous flow tubular reactor. Background Technology

[0002] Cyclic olefin copolymers (COCs) are polymers prepared by copolymerizing cyclic olefin monomers with α-olefins, etc. They possess low density, low hygroscopicity, high transparency, high heat resistance, high refractive index, and excellent processability. These amorphous thermoplastic polymers have attracted significant attention in industry and academia in recent years, showing broad application prospects in optical lenses, electronics, and pharmaceutical packaging. Currently, the mainstream processes for preparing COCs are based on traditional stirred tank reactors and homogeneous solution polymerization. Here, homogeneous solution polymerization refers to polymerization where the catalyst is soluble in the reaction system, and no solid catalyst is present in the polymerization system.

[0003] Current mainstream processes for preparing copolymers (COCs) all use cyclic olefin monomers (such as norbornene compounds) and α-olefins (such as ethylene) as raw materials, employing different catalysts to catalyze the polymerization reaction. Patent CN106232641A from Polyplastics Co., Ltd. of Japan discloses a method for preparing olefin copolymers in a stirred tank reactor. In the presence of a titanium cadmium catalyst, using norbornene-derived cyclic olefin monomers and C4-C12 α-olefin-derived α-olefin monomers as raw materials, although 1g of the aforementioned titanium cadmium catalyst can yield more than 1kg of copolymer, the polymerization temperature is low (40℃), the polymerization time is long (1-5h), and the activity per unit time is low. Chinese patent CN108752526A describes a method for preparing olefin copolymers in a stirred tank reactor using ethylene and / or α-olefins and norbornene compounds as raw materials, employing a metallocene catalyst with a catalyst concentration of 1-6×10⁻⁶. -5 mol / L, reaction temperature 40-80℃, reaction time 30 min, activity 1~17×10 6 g / mol Zr Each millimole of the main catalyst produces 2.9-8.5 kg of copolymer per h. Ticona Ltd.'s patent CN1245506A also uses a metallocene catalyst in an autoclave to prepare cyclic olefin copolymers (ethylene-norbornene copolymers). The reactants are ethylene and norbornene, with a norbornene concentration of 30-80 wt%. The catalyst is a metallocene catalyst, and the co-catalyst is an alkylaluminoxane at a ratio of 1:1 to 10000. The polymerization temperature is 70°C, the pressure is 3-58 bar, and the polymerization time is generally 8-30 min. At a pressure of 58 bar, the highest activity of this patent is only 2 × 10⁻⁶. 6 g / g Zr·h, the COC obtained per unit mass of main catalyst is only 400g. In order to improve the catalyst efficiency, the method adopted is to extend the reaction time (1h).

[0004] The aforementioned patents all employ stirred tank reactors. Although the catalyst is homogeneous, gaseous ethylene is continuously introduced into the reaction system, meaning the polymerization reaction is a gas-liquid two-phase reaction. Therefore, this heterogeneous polymerization presents several problems: First, for gas (ethylene)-liquid two-phase polymerization, there are serious mass transfer issues. The mass transfer of gas in the liquid significantly affects the actual monomer ratio (the monomer ratio of ethylene to cycloolefins) in the bulk polymerization reaction (liquid phase), thus affecting the stability of product quality and the compositional distribution of the copolymer, and also severely impacting the polymerization rate; Second... Scale-up of gas-liquid heterogeneous reactions in stirred tank reactors has always been a formidable engineering challenge. Third, according to literature (Macromol. Mater. Eng. 2004, 289, 475–479), metallocene catalysts exhibit a half-life at high temperatures and gradually deactivate with increasing reaction time. To prevent catalyst deactivation, the typical polymerization temperature range is 20-90℃. Low polymerization temperatures result in poor mass transfer, leading to low polymerization rates. To achieve higher economic benefits (high polymer yield), extending the polymerization reaction time is necessary. However, low temperatures in the polymerization system increase viscosity, further deteriorating mass and heat transfer effects. Fourth, the processes are all carried out in stirred tank reactors. Low ethylene pressure results in low activity, while high ethylene pressure poses significant safety hazards.

[0005] Currently, the most typical COC material is the ethylene-norbornene copolymer, in which norbornene (NB) is mainly produced by the Diels-Alder (DA) reaction of cyclopentadiene (CPD) and ethylene using liquid-phase or gas-phase processes. The product obtained from the reaction must be separated, purified, and stored to reach the polymerization grade before it can be used for COC preparation. This production process is cumbersome and energy-intensive.

[0006] Microchannel reactors are miniature reactors with characteristic dimensions between 10 and 300 micrometers (or less than 1000 micrometers) manufactured using compact fabrication technology. They are an important component of microchemical technology and have the characteristics of large specific surface area, high mass and heat transfer efficiency, low online material requirements, high pressure and high temperature resistance, continuous steady-state operation, and rapid scale-up. They have unique advantages in synthesizing organic compounds under high temperature / high pressure conditions.

[0007] The synthesis of the polymerization-grade cyclic olefin monomer norbornene using a microchannel reactor offers several advantages. Excellent mass transfer ensures more thorough mixing of reactants and reduces side reactions caused by poor mass transfer. The efficient mass transfer capability rapidly removes heat from the reaction, preventing hot spots, or transfers heat to promote endothermic reactions. Furthermore, the controllability, continuity, and excellent high-temperature and high-pressure resistance of the microchannel reactor enhance the safety of the reaction process and broaden experimental operating conditions. This overcomes the drawbacks of conventional high-temperature and high-pressure reactors, such as low conversion rates, numerous byproducts, and poor safety. Simultaneously, the preparation of cyclic olefin copolymers using a continuous flow tubular reactor demonstrates high catalytic efficiency and minimal catalyst deactivation even at high temperatures, enabling high polymer yields in a very short time. This method is safe, rapid, compositionally controllable, efficient, flexible, stable, and easily scalable for large-scale production.

[0008] In summary, current technologies using norbornene-derived cyclic olefin monomers as raw materials suffer from problems such as gas-liquid separation of upstream reaction solutions and purification of norbornene compounds, resulting in complex processes and high energy consumption.

[0009] The mainstream polymerization process uses a stirred tank reactor. When the reactant is a gas such as ethylene, the reaction system is a gas-liquid two-phase reaction. This heterogeneous polymerization has obvious disadvantages: First, for gas-liquid two-phase polymerization, the rate of mass transfer of gas into liquid affects the actual monomer ratio (the ratio of α-olefin to cycloolefin monomers) in the main polymer, thus affecting the stability of product quality and the composition distribution of the copolymer, and also seriously affecting the polymerization rate. Second, scaling up the gas-liquid heterogeneous reaction in the stirred tank reactor has always been a difficult engineering challenge. Third, according to the literature (Macromol. Mater. Eng. 2004, 289, 475–479), metallocene catalysts have a half-life at high temperatures and gradually deactivate with the extension of reaction time. In order to prevent catalyst deactivation, the general polymerization reaction temperature range is 20-90℃. Low polymerization temperature and poor mass transfer lead to low polymerization rate. In order to obtain higher economic benefits (high polymer yield), the polymerization reaction time must be extended. Low temperatures in polymerization systems increase viscosity, further worsening mass and heat transfer. Summary of the Invention

[0010] The technical problem to be solved by this invention is to provide a method for directly preparing cyclic olefin copolymers using dicyclopentadiene through a series continuous flow tubular reactor. This invention utilizes a continuous flow reactor to efficiently produce norbornene and its derivatives from ethylene and dicyclopentadiene, and then further reacts with excess ethylene to obtain cyclic olefin copolymers.

[0011] To address the aforementioned technical problems, this invention provides a method for directly preparing cyclic olefin copolymers from dicyclopentadiene and ethylene using a continuous flow reactor:

[0012] The continuous flow reactor includes an ethylene gas feed section, a norbornene monomer synthesis section, and a cyclic olefin copolymer polymerization section. Both the norbornene monomer synthesis section and the cyclic olefin copolymer polymerization section are tubular reactors.

[0013] The norbornene monomer synthesis section includes a preheating section, a monomer reaction section (referred to as the reaction section), and a cooling section connected in sequence.

[0014] The cyclic olefin copolymer polymerization section includes a pre-activation section and a polymerization section in sequence;

[0015] The ethylene gas feed section is connected to the monomer reaction section, and the cooling section is connected to the pre-activation section;

[0016] Includes the following steps:

[0017] The dicyclopentadiene solution is preheated in the preheating section to form a preheated product, and the preheated product discharged from the preheating section enters the monomer reaction section; the dicyclopentadiene solution is composed of dicyclopentadiene and an inert organic solvent; the mass concentration of dicyclopentadiene in the dicyclopentadiene solution is ≥1% (i.e., 1% to saturated solution, preferably 10 to 70%).

[0018] Ethylene enters the monomer reaction section through the ethylene gas feed section and reacts with the preheated product. The reaction temperature in the reaction section is 220-320℃ and the pressure is 15-30MPa. The residence time of ethylene in the monomer reaction section is 0.2-5min, and the molar ratio of ethylene to dicyclopentadiene is 0.1-10:1.

[0019] The catalyst mixture, consisting of a main catalyst solution and a co-catalyst solution, first enters the pre-activation section for mixing and pre-activation at 30–150°C; then it enters the polymerization section.

[0020] The reaction stock solution (a gas-liquid mixture) obtained from the monomer reaction section is cooled in the cooling section and depressurized by the back pressure valve before entering the polymerization section. Under the action of the pre-activated catalyst combination liquid, the polymerization reaction takes place. The reaction temperature in the polymerization section is 60–200℃, the reaction pressure in the polymerization section is 0.1–20 MPa, and the residence time of the reaction stock solution in the polymerization section is 2–300 s. The volume ratio of the reaction stock solution to the catalyst combination liquid is 1:1–2.

[0021] Note: The reaction stock solution is cooled to a temperature below the set temperature of the polymerization section after passing through the cooling section, and the pressure is reduced to the set pressure of the polymerization section.

[0022] As an improvement to the method of the present invention for the direct preparation of cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor:

[0023] The main catalyst is one of a bridged metallocene catalyst, a defined geometry catalyst, or a non-metallocene catalyst.

[0024] The cocatalyst is one of a composition consisting of alkylaluminoxane, alkylaluminum and boron-containing compounds;

[0025] When alkylaluminoxane is selected as the co-catalyst, the molar ratio of Al in the alkylaluminoxane to the metal atoms in the main catalyst is 100-2000:1, preferably 300-1000:1;

[0026] When the co-catalyst is a composition of alkylaluminum and boron-containing compounds, the molar ratio of aluminum atoms in the alkylaluminum to metal atoms in the main catalyst to boron atoms in the boron-containing compound is 50-2000:1:1-100, preferably 100-1000:1:3-50.

[0027] All solvents used are inert organic solvents, and are consistent with the inert organic solvents used in the dicyclopentadiene solution.

[0028] As a further improvement to the method of the present invention for the direct preparation of cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor:

[0029] The bridged metallocene catalysts are ethylene-bis(1-indenyl)zirconia, methylene-bis(cyclopentadienyl)zirconia, diphenylmethylene-bis(cyclopentadienyl)zirconia, and isopropene-bis(cyclopentadienyl)zirconia;

[0030] The catalysts with defined geometric configurations are (tert-butylamide)dimethyl-9-fluorenylsilane titanium dichloride, (isopropylamide)dimethyl-9-fluorenylsilane dimethyl titanium, and (tert-butylamide)dimethyl-9-fluorenylsilane dimethyl titanium.

[0031] As a further improvement to the method of the present invention for the direct preparation of cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor: the temperature of the preheating section is 160-220°C, and the pressure of the preheating section is equal to the reaction pressure in the monomer reaction section.

[0032] During the preheating process described above, dicyclopentadiene is partially or completely thermally decomposed into cyclopentadiene; therefore, the preheated product contains cyclopentadiene or both cyclopentadiene and dicyclopentadiene.

[0033] As a further improvement to the method of the present invention for the direct preparation of cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor: the cooling medium of the cooling section is circulating water or air.

[0034] As a further improvement to the method of the present invention for the direct preparation of cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor: the inert organic solvent is at least one of straight-chain aliphatic hydrocarbons, cyclic aliphatic hydrocarbons, and aromatic hydrocarbons.

[0035] As a further improvement to the method of the present invention for the direct preparation of cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor: the straight-chain aliphatic hydrocarbon is n-hexane or n-heptane, the cyclic aliphatic hydrocarbon is cyclohexane or cyclopentane, and the aromatic hydrocarbon is one of toluene, xylene, ethylbenzene, diethylbenzene, and their homologues.

[0036] As a further improvement to the method of the present invention for the direct preparation of cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor:

[0037] The preferred temperature for the preheating section is 160–220℃;

[0038] The preferred reaction temperature in the reaction section is 240–280°C, the preferred pressure is 20–25 MPa, and the preferred molar ratio of ethylene to dicyclopentadiene is 3–8:1; the preferred residence time of ethylene in the monomer reaction section is 1–3 min.

[0039] As a further improvement to the method of the present invention for the direct preparation of cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor:

[0040] The preferred pre-activation temperature is 60–90°C;

[0041] The preferred reaction temperature in the polymerization section is 100–150℃, the preferred pressure in the polymerization section is 0.1–1.6 MPa, and the preferred residence time of the reaction stock solution in the polymerization section is 30–50 s.

[0042] This invention addresses the drawbacks of cumbersome separation and purification processes of reaction stock solutions, high energy consumption, long reaction times, low production efficiency, low safety, and scale-up effects in the polymerization stage. It provides a method for directly preparing cyclic olefin copolymers using a continuous flow tubular reactor in series. Using dicyclopentadiene and ethylene as raw materials, this method achieves a continuous process from cyclic olefin monomer synthesis to cyclic olefin copolymer preparation. The cyclic olefin monomers do not require separation or extraction and directly participate in the polymerization reaction, effectively simplifying the original complex process, reducing energy consumption, and ensuring that the catalyst is not easily deactivated even at high temperatures during the polymerization stage, exhibiting high catalytic efficiency and enabling high polymer yields in a very short time.

[0043] The norbornene monomer synthesis section (preheating section, monomer reaction section and cooling section) is a stainless steel microchannel, and the cyclic olefin copolymer polymerization section (preactivation section and polymerization section) is a stainless steel pipe.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] (1) The cyclic olefin monomers obtained by the Diels-Alder reaction and the excess α-olefins in the reaction can be directly used in the polymerization reaction to prepare cyclic olefin copolymers without separation and purification.

[0046] (2) The continuous flow tubular reactor (i.e., continuous flow reactor) of the present invention has high heat transfer efficiency, which can transfer heat into or out of the system, so that the reaction can be carried out under near isothermal conditions, avoiding the generation of reaction hot spots, thereby effectively suppressing side reactions.

[0047] (3) The continuous flow tubular reactor of the present invention has high mass transfer efficiency and uniform mixing of reactants, which can reduce the difference in reaction process caused by poor mass transfer. Compared with conventional batch reactor, it does not require stirring or other moving equipment, which not only helps to reduce energy consumption and production costs, but also helps to seal the reactor and improve production safety.

[0048] (4) This invention develops a highly integrated, flexible, and adaptable continuous flow reactor for norbornene monomers. Using this integrated continuous flow reactor, only targeted adjustments to the process conditions and parameters are needed, including temperature and pressure settings, material concentration, material ratio, and material flow rate, to ensure their coordinated operation and reaction matching. This allows for the synthesis of cyclic olefin copolymers containing different norbornene monomers. In other words, a single reactor can efficiently produce different grades of cyclic olefin copolymers with polymer glass transition temperatures ranging from -10 to 150°C.

[0049] (5) No scale-up effect, meaning that the process can still be completed in a short time on an industrial scale, and the activity of the catalyst, the composition and properties of the polymer are basically the same as those on a laboratory scale.

[0050] (6) The catalyst of the method of the present invention is not easily deactivated, has a high utilization rate, is safe, fast, has controllable composition, is efficient, flexible, stable and easy to produce on a large scale. Attached Figure Description

[0051] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0052] Figure 1 This is a schematic diagram of the continuous flow tubular reactor of the present invention. Detailed Implementation

[0053] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto:

[0054] Example 1: A continuous flow tubular reactor, the structure of which is as follows Figure 1 As shown,

[0055] It includes an ethylene gas feed section, a norbornene monomer synthesis section, and a cyclic olefin copolymer polymerization section. Both the norbornene monomer synthesis section and the cyclic olefin copolymer polymerization section are tubular reactors. The norbornene monomer synthesis section includes a preheating section and a monomer reaction section, respectively. Figure 1 The reaction section (hereinafter referred to as the reaction section) and the cooling section are included. The cyclic olefin copolymer polymerization section includes a pre-activation section and a polymerization section connected in sequence. The ethylene gas feed section is connected to the monomer reaction section, and the cooling section is connected to the polymerization section through a back pressure valve.

[0056] The piping for the preheating section, monomer reaction section, and cooling section is all made of stainless steel microchannels (inner diameter 0.2–1 mm). The preheating section uses oil bath heating, and the cooling section uses circulating water bath or air cooling. The length of the monomer reaction section is 10–50 m.

[0057] The pre-activation section has a pipe diameter of 0.5–5 mm and a length of 1–2 m; the polymerization section has a pipe diameter of 0.5–5 mm and a length of 2–10 m.

[0058] Dicyclopentadiene is partially or completely thermally decomposed into cyclopentadiene in the preheating section.

[0059] A back pressure valve is installed at the outlet of the polymerization section.

[0060] Example 1:

[0061] 1) Prepare a 20 wt% dicyclopentadiene-toluene solution. The solution is preheated in a preheating section at 180°C and 20 MPa. The effluent from the preheating section is named the preheated dicyclopentadiene-toluene solution.

[0062] Under ambient temperature conditions, ethylene is directly fed from the ethylene gas feed section to the monomer reaction section. The molar ratio of ethylene to dicyclopentadiene in the dicyclopentadiene-toluene solution is 4:1. The ethylene and preheated dicyclopentadiene-toluene solution react in the monomer reaction section at a temperature of 280°C, a pressure of 20 MPa, and a residence time of 3 minutes (i.e., the residence time of ethylene in the reaction section is 3 minutes). The conversion rate of dicyclopentadiene is 98%. The reactants are cooled in a cooling section and depressurized by a back pressure valve (cooling to a temperature below the polymerization section temperature and depressurizing to the polymerization section pressure) before entering the polymerization section.

[0063] 2) The main catalyst solution is a toluene solution of ethylene-bis(1-indenyl)zirconia (code c) with a concentration of 3.2 × 10⁻⁶. -5 The concentration of co-catalyst 1 was 1.92 × 10⁻⁶ mol / L, and the concentration of co-catalyst 1 was a toluene solution of triisobutylaluminum. -2 The concentration of co-catalyst 2 was 9.6 × 10⁻⁶ mol / L, and the toluene solution of triphenyl methyl tetratetra(pentafluorophenyl)borate was also present. -5The molar ratio of ethylene-bis(1-indenyl)zirconium dichloride (code c), triisobutylaluminum, and tetra(pentafluorophenyl)borate triphenyl methyl ester is 1:600:3; the flow rates of the main catalyst solution, co-catalyst 1, and co-catalyst 2 are all 0.6 mL / min. Therefore, the residence time of the main catalyst solution, co-catalyst 1, and co-catalyst 2 in the pre-activation section is 20 s, and the temperature of the pre-activation section is 90 °C; the effluent from the outlet of the pre-activation section is named the activated mixed catalyst.

[0064] The flow rate of the depressurized reactant obtained in step 1) into the polymerization section is 1.8 mL / min, and the flow rate of the activated mixed catalyst into the polymerization section is 1.8 mL / min. Therefore, the volume ratio of the depressurized reactant obtained in step 1) to the activated mixed catalyst is 1:1.

[0065] The polymerization section temperature was 130℃, the polymerization pressure was 0.6MPa, and the polymerization reaction time was 50s. The reaction liquid flowing out from the end of the polymerization section was reduced to atmospheric pressure by a back pressure valve and then subjected to conventional post-processing to obtain the cyclic olefin copolymer.

[0066] Post-processing can be as follows: Collect the depressurized reaction solution at the outlet for 5 minutes and precipitate it in 0.5 L of 5% (v / v) hydrochloric acid-acidified ethanol with stirring (precipitating while stirring). Then filter, dry the resulting filter cake (drying at 80°C to constant weight) to obtain the cyclic olefin copolymer. The final cyclic olefin copolymer is named ethylene-norbornene copolymer; yield (kg·g) -1 The value was 10.2, and the activity (10) 6 g mol -1 h -1 The α value is 14.3, and the glass transition temperature is 72.1℃.

[0067] Example 2:

[0068] 1) Prepare a 10wt% dicyclopentadiene-toluene solution. The dicyclopentadiene-toluene solution is preheated in the preheating section at a temperature of 180℃ and a pressure of 20MPa.

[0069] Under ambient temperature conditions, ethylene is directly fed from the ethylene gas feed section to the monomer reaction section. The molar ratio of ethylene to dicyclopentadiene in the dicyclopentadiene-toluene solution is 4:1. The ethylene and preheated dicyclopentadiene-toluene solution react in the monomer reaction section at a temperature of 240°C, a pressure of 20 MPa, and a residence time of 2 minutes, achieving a dicyclopentadiene conversion rate of 62%. The reactants are then cooled in a cooling section and depressurized by a back pressure valve before entering the polymerization section.

[0070] 2) The main catalyst solution is a toluene solution of ethylene-bis(1-indenyl)zirconia (code c) with a concentration of 3.2 × 10⁻⁶. -5 The concentration of co-catalyst 1 was 1.92 × 10⁻⁶ mol / L, and the concentration of co-catalyst 1 was a toluene solution of triisobutylaluminum. -2 The concentration of co-catalyst 2 was 9.6 × 10⁻⁶ mol / L, and the toluene solution of triphenyl methyl tetratetra(pentafluorophenyl)borate was also present. -5 The concentration of the catalyst solution was mol / L, and the molar ratio of ethylene-bis(1-indenyl)zirconium dichloride (designated c), triisobutylaluminum, and triphenyl methyl tetratetra(pentafluorophenyl)borate was 1:600:3; the mass flow rate of both the main catalyst solution and the co-catalyst solution was 1.1 mL / min. The temperature of the pre-activation section was 70℃.

[0071] The flow rate of the depressurized reactant entering the polymerization section after step 1) is 3.3 mL / min, and the flow rate of the activated mixed catalyst entering the polymerization section is 3.3 mL / min. Therefore, the volume ratio of the depressurized reactant to the activated mixed catalyst is 1:1.

[0072] The polymerization section temperature was 110℃, the polymerization pressure was 0.4MPa, and the polymerization reaction time was 30s. After the reaction liquid flowing out from the end of the polymerization section was cooled to atmospheric pressure, it underwent conventional post-processing to obtain the cyclic olefin copolymer.

[0073] The final cyclic olefin copolymer is named ethylene-norbornene copolymer; yield (kg·g) -1 The value was 12.6, and the activity (10) 6 g mol -1 h -1 The φ is 28.3, and the glass transition temperature is 52.8℃.

[0074] Example 3:

[0075] 1) Prepare a 15wt% dicyclopentadiene-toluene solution. The dicyclopentadiene-toluene solution is preheated in the preheating section at a temperature of 180℃ and a pressure of 20MPa.

[0076] Under ambient temperature conditions, ethylene is directly fed from the ethylene gas feed section to the monomer reaction section. The molar ratio of ethylene to dicyclopentadiene in the dicyclopentadiene-toluene solution is 6:1. The ethylene and preheated dicyclopentadiene-toluene solution react in the monomer reaction section at a temperature of 260°C, a pressure of 25 MPa, and a residence time of 1 min, achieving a dicyclopentadiene conversion rate of 64%. The reactants are then cooled in a cooling section and depressurized by a back pressure valve before entering the polymerization section.

[0077] 2) The main catalyst solution is a toluene solution of ethylene-bis(1-indenyl)zirconia (code c) with a concentration of 3.2 × 10⁻⁶. -5 The concentration of co-catalyst 1 was 9.6 × 10⁻⁶ mol / L, and the concentration of co-catalyst 1 was a toluene solution of triisobutylaluminum. -3 The concentration of co-catalyst 2 was 9.6 × 10⁻⁶ mol / L, and the toluene solution of triphenyl methyl tetratetra(pentafluorophenyl)borate was also present. -5 The concentration of the catalyst solution was mol / L, and the molar ratio of ethylene-bis(1-indenyl)zirconium dichloride (designated c), triisobutylaluminum, and triphenyl methyl tetratetra(pentafluorophenyl)borate was 1:300:3; the mass flow rate of the main catalyst solution and the flow rate of the co-catalyst solution were both 1.0 mL / min. The temperature of the pre-activation section was 70 °C.

[0078] The flow rate of the depressurized reactant obtained in step 1) into the polymerization section is 1.5 mL / min, and the flow rate of the activated mixed catalyst into the polymerization section is 3.0 mL / min. Therefore, the ratio of the depressurized reactant to the activated mixed catalyst is 1:2. The polymerization section temperature is 120℃, the polymerization pressure is 0.8 MPa, and the polymerization reaction time is 40 s. After the reaction liquid flowing out from the end of the polymerization section is reduced to atmospheric pressure, it undergoes conventional post-treatment to obtain the cyclic olefin copolymer.

[0079] The final cyclic olefin copolymer is named ethylene-norbornene copolymer; yield (kg·g) -1 The value was 14.8, and the activity (10) 6 g mol -1 h -1 The value is 41.7, and the glass transition temperature is 23.7℃.

[0080] Example 4:

[0081] A 10 wt% dicyclopentadiene-toluene solution was prepared and preheated in a preheating section at a temperature of 180°C and a pressure of 20 MPa.

[0082] Under ambient temperature conditions, ethylene is directly fed from the ethylene gas feed section to the monomer reaction section. The molar ratio of ethylene to dicyclopentadiene in the dicyclopentadiene-toluene solution is 8:1. The ethylene and preheated dicyclopentadiene-toluene solution react in the monomer reaction section at a temperature of 280°C, a pressure of 20 MPa, and a residence time of 2 minutes. The conversion rate of dicyclopentadiene is 94%. The reactants are cooled in the cooling section and depressurized by the back pressure valve before entering the polymerization section.

[0083] 2) The main catalyst solution is a toluene solution of ethylene-bis(1-indenyl)zirconia (code c) with a concentration of 4.8 × 10⁻⁶. -5The concentration of co-catalyst 1 was 1.44 × 10 mol / L, and the co-catalyst 1 was a toluene solution of triisobutylaluminum with a concentration of 1.44 × 10 mol / L. -2 The co-catalyst 2 is a toluene solution of triphenyl methyl tetratetra(pentafluorophenyl)borate with a concentration of 1.44 × 10⁻⁶ mol / L. -4 The concentration of the catalyst solution was mol / L, and the molar ratio of ethylene-bis(1-indenyl)zirconium dichloride (designated c), triisobutylaluminum, and triphenyl methyl tetratetra(pentafluorophenyl)borate was 1:300:3; the mass flow rate of the main catalyst solution and the flow rate of the co-catalyst solution were both 0.8 mL / min. The temperature of the pre-activation section was 70 °C.

[0084] The flow rate of the depressurized reactant entering the polymerization section after step 1) is 1.6 mL / min, and the flow rate of the activated mixed catalyst entering the polymerization section is 2.4 mL / min. Therefore, the volume ratio of the depressurized reactant to the activated mixed catalyst is 1:1.5.

[0085] The polymerization section temperature was 150℃, the polymerization pressure was 1.2MPa, and the polymerization reaction time was 45s. After the reaction liquid flowing out from the end of the polymerization section was cooled to atmospheric pressure, it underwent conventional post-processing to obtain the cyclic olefin copolymer.

[0086] The final cyclic olefin copolymer is named ethylene-norbornene copolymer; yield (kg·g) -1 The value was 16.8, and the activity (10) 6 g mol -1 h -1 The value is 34.7, and the glass transition temperature is 5.4℃.

[0087] Example 5:

[0088] A 15 wt% dicyclopentadiene-toluene solution was prepared and preheated in a preheating section at a temperature of 180°C and a pressure of 20 MPa.

[0089] Under ambient temperature conditions, ethylene is directly fed from the ethylene gas feed section to the monomer reaction section. The molar ratio of ethylene to dicyclopentadiene in the dicyclopentadiene-toluene solution is 8:1. The ethylene and preheated dicyclopentadiene-toluene solution react in the monomer reaction section at a temperature of 280°C, a pressure of 25 MPa, and a residence time of 2 minutes, achieving a dicyclopentadiene conversion rate of 95%. The reactants are then cooled in a cooling section and depressurized by a back pressure valve before entering the polymerization section.

[0090] 2) The main catalyst solution is a toluene solution of ethylene-bis(1-indenyl)zirconia (code c) with a concentration of 4.8 × 10⁻⁶. -5 The concentration of co-catalyst 1 was 2.88 × 10⁻⁶ mol / L, and the concentration of co-catalyst 1 was a toluene solution of triisobutylaluminum.-2 The co-catalyst 2 is a toluene solution of triphenyl methyl tetratetra(pentafluorophenyl)borate with a concentration of 1.44 × 10⁻⁶ mol / L. -4 The concentration of the catalyst solution was mol / L, and the molar ratio of ethylene-bis(1-indenyl)zirconium dichloride (designated c), triisobutylaluminum, and triphenyl methyl tetratetra(pentafluorophenyl)borate was 1:600:3; the mass flow rate of the main catalyst solution and the flow rate of the co-catalyst solution were both 1.0 mL / min. The temperature of the pre-activation section was 70 °C.

[0091] The flow rate of the depressurized reactant entering the polymerization section after step 1) is 3.0 mL / min, and the flow rate of the activated mixed catalyst entering the polymerization section is 3.0 mL / min. Therefore, the volume ratio of the depressurized reactant to the activated mixed catalyst is 1:1.

[0092] The polymerization section temperature was 130℃, the polymerization pressure was 1.0 MPa, and the polymerization reaction time was 40 s. After the reaction liquid flowing out from the end of the polymerization section was cooled to atmospheric pressure, it underwent conventional post-processing to obtain the cyclic olefin copolymer.

[0093] The final cyclic olefin copolymer is named ethylene-norbornene copolymer; yield (kg·g) -1 The value was 15.3, and the activity (10) 6 g mol -1 h -1 The φ is 38.7, and the glass transition temperature is 13.7℃.

[0094] Examples 6 to 10: The parameters in Example 1 were changed accordingly as shown in Table 1, while the rest remained the same as in Example 1. The results are shown in Table 1 below.

[0095] Note: The formula for calculating the yield is: polymer as product [g] / (mass of the main catalyst metallocene [g]).

[0096] The formula for calculating activity is: Activity = Polymer [g] / (Time [h] × Molar amount of main catalyst metallocene [mol])

[0097] Polymer glass transition temperature: Test methods are ISO 11375-1, -2, -3.

[0098] The results are shown in Table 1.

[0099] Table 1

[0100]

[0101]

[0102] Finally, it should be noted that the above examples are merely some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A method for the direct preparation of cyclic olefin copolymers from dicyclopentadiene and ethylene using a continuous flow reactor, characterized by: The continuous flow reactor includes an ethylene gas feed section, a norbornene monomer synthesis section, and a cyclic olefin copolymer polymerization section. Both the norbornene monomer synthesis section and the cyclic olefin copolymer polymerization section are tubular reactors. The norbornene monomer synthesis section includes a preheating section, a monomer reaction section, and a cooling section connected in sequence. The cyclic olefin copolymer polymerization section includes a pre-activation section and a polymerization section in sequence; The ethylene gas feed section is connected to the monomer reaction section, and the cooling section is connected to the pre-activation section after passing through the back pressure valve. Includes the following steps: The dicyclopentadiene solution is preheated in the preheating section to form a preheated product, and the preheated product discharged from the preheating section enters the monomer reaction section; the dicyclopentadiene solution is composed of dicyclopentadiene and an inert organic solvent; the mass concentration of dicyclopentadiene in the dicyclopentadiene solution is 10-70%. Ethylene enters the monomer reaction section through the ethylene gas feed section and reacts with the preheated product. The reaction temperature in the reaction section is 220-320℃ and the pressure is 15-30MPa. The residence time of ethylene in the monomer reaction section is 0.2-5min. The molar ratio of ethylene to dicyclopentadiene is 1-10:

1. The catalyst mixture, consisting of a main catalyst solution and a co-catalyst solution, first enters the pre-activation section for mixing and pre-activation at 30–150°C; then it enters the polymerization section. The reaction stock solution obtained from the monomer reaction section is cooled in the cooling section and depressurized by the back pressure valve before entering the polymerization section. Under the action of the pre-activated catalyst combination liquid, the polymerization reaction takes place. The reaction temperature in the polymerization section is 60-200℃, the reaction pressure in the polymerization section is 0.1-20MPa, and the residence time of the reaction stock solution in the polymerization section is 2-300s. The volume ratio of the reaction stock solution to the catalyst combination liquid is 1:1-2. The main catalyst is one of a bridged metallocene catalyst, a defined geometry catalyst, or a non-metallocene catalyst. The cocatalyst is one of a composition consisting of alkylaluminoxane, alkylaluminum and boron-containing compounds; When an alkylaluminoxane is selected as the co-catalyst, the molar ratio of Al in the alkylaluminoxane to the metal atoms in the main catalyst is 100 to 2000:

1. When the co-catalyst is a combination of alkylaluminum and boron-containing compounds, the molar ratio of aluminum atoms in the alkylaluminum to metal atoms in the main catalyst to boron atoms in the boron-containing compound is 50-2000:1:1-100. All solvents used are inert organic solvents, and are consistent with the inert organic solvents used in the dicyclopentadiene solution.

2. The method for directly preparing cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor according to claim 1, characterized in that: The bridged metallocene catalysts are ethylene-bis(1-indenyl)zirconia, methylene-bis(cyclopentadienyl)zirconia, diphenylmethylene-bis(cyclopentadienyl)zirconia, and isopropene-bis(cyclopentadienyl)zirconia; The catalysts with defined geometric configurations are (tert-butylamide)dimethyl-9-fluorenylsilane titanium dichloride, (isopropylamide)dimethyl-9-fluorenylsilane dimethyl titanium, and (tert-butylamide)dimethyl-9-fluorenylsilane dimethyl titanium.

3. The method for directly preparing cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor according to claim 2, characterized in that: The temperature of the preheating section is 120℃~240℃, and the pressure of the preheating section is equal to the reaction pressure in the monomer reaction section.

4. The method for directly preparing cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor according to claim 3, characterized in that: The cooling medium in the cooling section is either circulating water or air.

5. The method for directly preparing cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor according to any one of claims 1 to 4, characterized in that: The inert organic solvent is at least one of straight-chain aliphatic hydrocarbons, cyclic aliphatic hydrocarbons, and aromatic hydrocarbons.

6. The method for directly preparing cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor according to claim 5, characterized in that: The straight-chain aliphatic hydrocarbon is n-hexane or n-heptane, the cyclic aliphatic hydrocarbon is cyclohexane or cyclopentane, and the aromatic hydrocarbon is one of toluene, xylene, ethylbenzene, diethylbenzene, and their homologues.

7. The method for directly preparing cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor according to claim 6, characterized in that: Preheating section temperature: 160–220℃; The reaction temperature in the reaction section is 240–280℃, the pressure is 20–25 MPa, and the molar ratio of ethylene to dicyclopentadiene is 3–8:1; the residence time of ethylene in the monomer reaction section is 1–3 min.

8. The method for directly preparing cyclic olefin copolymers from dicyclopentadiene and ethylene based on a continuous flow reactor according to claim 7, characterized in that: Pre-activation temperature: 0–90℃; The reaction temperature in the polymerization section is 100–150℃, the pressure in the polymerization section is 0.1–1.6 MPa, and the residence time of the reaction stock solution in the polymerization section is 30–50 s.

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