Polymerization apparatus, butadiene rubber, and method for producing same

Abstract

This invention relates to butadiene polymerization process, and discloses a polymerization reactor, cis-butadiene rubber, and a method for preparing the same. The reactor includes: a reactor, a rare earth catalyst pipeline, a Mooney viscosity modifier pipeline, a polymerization solution inlet pipeline, a first static mixer, and a second static mixer. The first static mixer is used to mix the rare earth catalyst and the polymerization solution, and its length is not less than 0.5 m. The second static mixer is used to mix the Mooney viscosity modifier and the product exiting the first static mixer, and its length is not less than 2 m. The outlet of the second static mixer is connected to the reactor for conveying the reaction raw materials into the reactor. The reactor, with its first and second static mixers, can accurately and effectively control the monomer conversion rate of the polymerization reaction and the Mooney viscosity of the polymerized cis-butadiene rubber, thereby improving production efficiency and product quality stability.

Description

Technical Field

[0001] This invention relates to butadiene polymerization process, specifically to a polymerization reactor, cis-butadiene rubber, and a method for preparing the same. Background Technology

[0002] Polybutadiene rubber (PPB) possesses high elasticity, excellent abrasion resistance, and good heat resistance, aging resistance, flexural strength, low heat generation, and low hysteresis loss. Furthermore, it is abundant and inexpensive in terms of raw material resources. Compared to natural rubber and styrene-butadiene rubber (SBR), its cold resistance, abrasion resistance, and elasticity are superior after vulcanization, making it particularly suitable for tire manufacturing. Since a US company pioneered the industrial production of PPB using titanium-based catalysts and solution polymerization in 1960, production has rapidly increased with the development of the petrochemical industry and driven by the tire manufacturing industry. By 1964, its production capacity ranked second among the seven major general-purpose synthetic rubbers, second only to SBR.

[0003] In 1958, Takeshi Matsumoto and others first discovered that reduced nickel supported on acidic substances had the ability to initiate butadiene polymerization. This marked the beginning of nickel-based directed polymerization of butadiene. Around 1965, Japan and other countries were the first to industrialize butadiene polymerization using a ternary nickel system consisting of nickel naphthenate, triethylaluminum, and boron trifluoride diethyl ether complex, with toluene as a solvent.

[0004] Polymerization technology is the core of NiBR production technology, and the conversion rate directly affects the energy and material consumption of the product, as well as the production capacity of the equipment. To date, nickel-based butadiene rubber (NiBR) production technology has been widely used, and significant progress has been made in all aspects. In actual production, water acts as a monocatalyst in the nickel-based catalytic system, participating in the generation of active species. While water can regulate reaction activity during the reaction, it is also a harmful impurity. It reacts with Al, damaging the active sites of the catalyst and thus affecting the stability of the product's Mooney viscosity.

[0005] CN212999912U discloses a continuous preparation apparatus for nickel-based butadiene rubber and rare earth-based butadiene rubber, which achieves flexible switching between the production of nickel-based butadiene rubber and rare earth-based butadiene rubber through the same polymerization apparatus, but does not improve the Mooney viscosity stability of the product.

[0006] Therefore, the Mooney viscosity of nickel-based cis-butadiene products typically fluctuates between 40 and 50, which affects the application of the products in more specific downstream sectors. This necessitates an apparatus and preparation method capable of producing cis-butadiene products with stable Mooney viscosity. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of difficult control of Mooney viscosity and poor product stability of cis-butadiene rubber in the prior art, and to provide a polymerization reaction apparatus, cis-butadiene rubber and its preparation method. The apparatus is equipped with a first static mixer and a second static mixer, which can accurately and effectively control the monomer conversion rate of the polymerization reaction, accurately control the Mooney viscosity of the polymerized product cis-butadiene rubber, improve production efficiency and improve product quality stability.

[0008] To achieve the above objectives, the first aspect of the present invention provides a polymerization reaction apparatus, wherein the apparatus comprises: a reaction vessel, a rare earth catalyst pipeline, a Mooney viscosity modifier pipeline, a polymerization solution inlet pipeline, a first static mixer, and a second static mixer;

[0009] The outlet of the rare earth catalyst pipeline is connected to the inlet of the first static mixer for conveying the rare earth catalyst; the outlet of the polymerization solution inlet pipeline is connected to the inlet of the first static mixer for conveying the polymerization solution; the first static mixer is used to mix the rare earth catalyst and the polymerization solution, and the length of the first static mixer is not less than 0.5m.

[0010] The outlet of the Mooney viscosity modifier pipeline is connected to the inlet of the second static mixer for conveying the Mooney viscosity modifier. The outlet of the first static mixer is connected to the inlet of the second static mixer. The second static mixer is used to mix the Mooney viscosity modifier with the product from the outlet of the first static mixer. The length of the second static mixer is not less than 2m. The outlet of the second static mixer is connected to the reactor for conveying the reaction raw materials into the reactor.

[0011] Preferably, the diameter of the first static mixer is 40-70 mm, and more preferably 50-60 mm.

[0012] Preferably, the length of the first static mixer is 0.5-1m.

[0013] Preferably, the diameter of the second static mixer is 40-70 mm, and more preferably 50-60 mm.

[0014] Preferably, the length of the second static mixer is 2-3m.

[0015] Preferably, the rare earth catalyst pipeline is equipped with a rare earth catalyst flow control unit for adjusting the feed flow rate of the rare earth catalyst.

[0016] Preferably, the Mooney viscosity modifier pipeline is equipped with a Mooney viscosity modifier flow control unit for adjusting the feed flow rate of the Mooney viscosity modifier.

[0017] Preferably, a monomer conversion rate measuring unit is provided on the polymerization solution inlet pipeline for measuring the inlet monomer conversion rate in the polymerization solution.

[0018] Preferably, the reaction vessel includes a vessel body and a jacket.

[0019] Preferably, a stirrer is provided in the reactor body.

[0020] Preferably, the apparatus further includes a polymerization solution outlet pipeline, wherein the material outlet of the reactor is connected to the inlet of the polymerization solution outlet pipeline.

[0021] Preferably, a Mooney viscosity measuring unit is installed on the polymerization solution outlet pipeline to measure the Mooney viscosity of the polymerization product.

[0022] Preferably, the device further includes a control unit that adjusts the feed flow rate of the rare earth catalyst and the feed flow rate of the Mooney viscosity modifier based on the received monomer conversion rate and Mooney viscosity measurement data.

[0023] A second aspect of the present invention provides a method for preparing cis-butadiene rubber, wherein the method is carried out in the polymerization apparatus described in the first aspect;

[0024] The method includes the following steps:

[0025] The polymerization solution containing the monomers enters the first static mixer through the polymerization solution inlet pipeline. The rare earth catalyst enters the first static mixer through the rare earth catalyst pipeline. After mixing in the first static mixer, the product from the first static mixer outlet enters the second static mixer. The Mooney viscosity modifier enters the second static mixer through the Mooney viscosity modifier pipeline. After mixing with the product from the first static mixer outlet, the product enters the reactor for polymerization reaction.

[0026] Preferably, the polymerization reaction is carried out by adjusting the feed flow rate N of the rare earth catalyst according to the following formula (1), and adjusting the feed flow rate A of the Mooney viscosity modifier according to the measured Mooney viscosity of the polymerization product and the following formula (2).

[0027] N=M(1-X)C cat (1)

[0028] Where M is the unpolymerized monomer flow rate, in mol / h;

[0029] X represents the monomer conversion rate of the polymerization solution when it enters the reactor;

[0030] C cat The amount of catalyst required for complete monomer conversion;

[0031] The feed flow rate N of the rare earth catalyst is every time t N Re-evaluate t N It is 0.2-1 times the reaction residence time.

[0032] A = N(D)add / D cat (2)

[0033] Among them, D add The ratio of the amount of Mooney viscosity modifier added to the amount of catalyst (calculated as rare earth element) added to the reactor at the same time;

[0034] D cat It is the ratio of the amount of Mooney viscosity modifier in the catalyst to the amount of catalyst as rare earth element.

[0035] The feed flow rate A of the Mooney viscosity modifier is every time t A Re-evaluate t A It is 0.2-0.5 times the reaction residence time.

[0036] Preferably, when the Mooney viscosity is below a set value, every t A Reduce D by 3% add Continue until the Mooney viscosity value is within ±3% of the set value.

[0037] Preferably, t N The time is 0.5-3 hours, preferably 1-2.5 hours.

[0038] Preferably, t A The time is 0.2-2 hours, preferably 0.5-1.8 hours.

[0039] Preferably, the polymerization reaction conditions include: a reaction temperature of 0-200℃, preferably 20-120℃; a reaction pressure of 0-11MPa, preferably 0-0.6MPa; and a reaction residence time of 0-10 hours, preferably 1-5 hours.

[0040] Preferably, the rare earth catalyst is selected from one or more of the following: neodymium neodecanoate catalytic system, neodymium isooctanoate catalytic system, neodymium sulfonate catalytic system, neodymium phosphonate catalytic system, and neodymium isopropoxy catalytic system.

[0041] The third aspect of the present invention provides a butadiene rubber prepared by the method described in the second aspect.

[0042] The beneficial effects achieved through the above technical solution are as follows:

[0043] In this invention, the monomer conversion rate of the polymerization reaction can be precisely and effectively controlled. Rare earth catalyst and Mooney viscosity modifier are mixed with the polymerization solution and then introduced into the reactor to precisely control the Mooney viscosity of the polymerized product, cis-butadiene rubber, thereby improving production efficiency and product quality stability. Attached Figure Description

[0044] Figure 1This is a schematic diagram of the polymerization reactor of the present invention.

[0045] Explanation of reference numerals in the attached figures

[0046] 1-Reaction vessel; 2-Agitator; 3-Rare earth catalyst pipeline; 4-Rare earth catalyst flow control unit; 5-Mounney viscosity modifier pipeline; 6-Mounney viscosity modifier flow control unit; 7-Polymerization solution inlet pipeline; 8-Monomer conversion rate measurement unit; 9-Polymerization solution outlet pipeline; 10-Mounney viscosity measurement unit; 11-Control unit; 12-First static mixer; 13-Second static mixer. Detailed Implementation

[0047] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0048] The first aspect of the present invention provides a polymerization reaction apparatus, wherein the apparatus comprises: a reaction vessel, a rare earth catalyst pipeline, a Mooney viscosity modifier pipeline, a polymerization solution inlet pipeline, a first static mixer, and a second static mixer;

[0049] The outlet of the rare earth catalyst pipeline is connected to the inlet of the first static mixer for conveying the rare earth catalyst; the outlet of the polymerization solution inlet pipeline is connected to the inlet of the first static mixer for conveying the polymerization solution; the first static mixer is used to mix the rare earth catalyst and the polymerization solution, and the length of the first static mixer is not less than 0.5m.

[0050] The outlet of the Mooney viscosity modifier pipeline is connected to the inlet of the second static mixer for conveying the Mooney viscosity modifier. The outlet of the first static mixer is connected to the inlet of the second static mixer. The second static mixer is used to mix the Mooney viscosity modifier with the product from the outlet of the first static mixer. The length of the second static mixer is not less than 2m. The outlet of the second static mixer is connected to the reactor for conveying the reaction raw materials into the reactor.

[0051] In this invention, the polymerization reaction apparatus is equipped with a first static mixer and a second static mixer. The rare earth catalyst is mixed with the polymerization solution and then mixed with the Mooney viscosity modifier to carry out the polymerization reaction. This can accurately and effectively control the monomer conversion rate of the polymerization reaction, accurately control the Mooney viscosity of the polymerized product cis-butadiene rubber, improve production efficiency, and improve product quality stability.

[0052] According to the present invention, preferably, the diameter of the first static mixer is 40-70 mm, for example, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, or any range between the two, preferably 50-60 mm. In the present invention, the types of the first and second static mixers are not particularly limited, and can be conventional static mixers in the art.

[0053] According to the present invention, preferably, the length of the first static mixer is 0.5-1m.

[0054] According to the present invention, preferably, the diameter of the second static mixer is 40-70mm, for example 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, or any range between the two, preferably 50-60mm.

[0055] According to the present invention, preferably, the length of the second static mixer is 2-3m.

[0056] According to a preferred embodiment of the present invention, the length-to-diameter ratio of the first static mixer is 5-25:1, for example 5:1, 10:1, 15:1, 20:1, 25:1, or any range between the two, preferably 10-20:1.

[0057] According to a preferred embodiment of the present invention, the length-to-diameter ratio of the second static mixer is 30-75:1, for example 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, or any range between the two, preferably 30-60:1.

[0058] According to the present invention, preferably, a rare earth catalyst flow control unit is provided on the rare earth catalyst pipeline for adjusting the feed flow rate of the rare earth catalyst.

[0059] According to the present invention, preferably, the Mooney viscosity modifier pipeline is provided with a Mooney viscosity modifier flow control unit for adjusting the feed flow rate of the Mooney viscosity modifier.

[0060] In this invention, preferably, a first static mixer and a second static mixer are respectively set up to mix the rare earth catalyst and the polymerization solution, as well as the Mooney viscosity modifier and the polymerization solution. At the same time, the feed flow rates of the rare earth catalyst and the Mooney viscosity modifier are precisely controlled by the rare earth catalyst flow control unit and the Mooney viscosity modifier control unit to stabilize the Mooney viscosity of the polymerization product.

[0061] According to the present invention, preferably, a monomer conversion measurement unit is provided on the polymerization solution inlet pipeline for measuring the inlet monomer conversion rate in the polymerization solution. In the present invention, an online gas chromatograph can be used, for example, as the monomer conversion measurement unit.

[0062] According to the present invention, preferably, the reactor includes a vessel body and a jacket. The reactor is provided with a material inlet and a material outlet. The jacket surrounds the vessel body and is used to adjust the temperature of the polymerization reaction.

[0063] According to the present invention, in order to achieve more uniform mixing of materials in the reactor and obtain polymer products with better performance, preferably, a stirrer is provided in the reactor body.

[0064] According to the present invention, preferably, the apparatus further includes a polymerization solution outlet pipeline, wherein the material outlet of the reactor is connected to the inlet of the polymerization solution outlet pipeline.

[0065] According to the present invention, preferably, a Mooney viscosity measuring unit is provided on the polymerization solution outlet line for measuring the Mooney viscosity of the polymerization product. The Mooney viscosity measuring unit can, for example, be an online Mooney viscometer.

[0066] According to the present invention, preferably, the apparatus further includes a control unit that adjusts the feed flow rate of the catalyst and the feed flow rate of the Mooney viscosity modifier based on received monomer conversion and Mooney viscosity measurement data. The control unit may, for example, be a DCS system.

[0067] A flow measurement control unit, for example, can be a mass flow meter.

[0068] A second aspect of the present invention provides a method for preparing cis-butadiene rubber, wherein the method is carried out in the polymerization reactor described in the first aspect;

[0069] The polymerization solution containing the monomers enters the first static mixer through the polymerization solution inlet pipeline. The rare earth catalyst enters the first static mixer through the rare earth catalyst pipeline. After mixing in the first static mixer, the product from the first static mixer outlet enters the second static mixer. The Mooney viscosity modifier enters the second static mixer through the Mooney viscosity modifier pipeline. After mixing with the product from the first static mixer outlet, the product enters the reactor for polymerization reaction.

[0070] According to the present invention, preferably, the polymerization reaction is carried out by adjusting the feed flow rate N of the rare earth catalyst according to the following formula (1), and adjusting the feed flow rate A of the Mooney viscosity modifier according to the measured Mooney viscosity of the polymerization product and the following formula (2).

[0071] N=M(1-X)C cat (1)

[0072] Where M is the unpolymerized monomer flow rate, in mol / h;

[0073] X represents the monomer conversion rate of the polymerization solution when it enters the reactor;

[0074] C cat The amount of catalyst required for complete monomer conversion;

[0075] The feed flow rate N of the rare earth catalyst is every time t N Re-evaluate t N It is 0.2-1 times the reaction residence time.

[0076] A = N(D) add / D cat (2)

[0077] Among them, D add The ratio of the amount of Mooney viscosity modifier added to the amount of catalyst (calculated as rare earth element) added to the reactor at the same time;

[0078] D cat It is the ratio of the amount of Mooney viscosity modifier in the catalyst to the amount of catalyst as rare earth element.

[0079] The feed flow rate A of the Mooney viscosity modifier is every time t A Re-evaluate t A It is 0.2-0.5 times the reaction residence time.

[0080] In this invention, the polymerization apparatus described in the first aspect is used in conjunction with the above formulas (1) and (2) to precisely control the feed flow rates of the rare earth catalyst and the Mooney viscosity modifier, thereby obtaining a polymerization product with stable Mooney viscosity.

[0081] In this invention, M represents the flow rate of unpolymerized monomer. Specifically, it refers to the flow rate of the polymerization solution entering the reactor, calculated based on unpolymerized monomer.

[0082] In this invention, D add This refers to the ratio of the amount of Mooney viscosity modifier added to the amount of catalyst added simultaneously to the reactor, calculated as rare earth elements. Specifically, for example, when an alkylaluminum is used as the added Mooney viscosity modifier and neodymium phosphonate is used as the main catalyst to prepare a polymerization catalyst, this is the ratio of the amount of alkylaluminum (calculated as the amount of aluminum) to the amount of catalyst (calculated as the amount of neodymium).

[0083] In this invention, D catThis refers to the ratio of the amount of Mooney viscosity modifier in the catalyst to the amount of catalyst in terms of rare earth elements. Specifically, for example, when using alkylaluminum as the Mooney viscosity modifier in the catalyst and neodymium phosphonate as the main catalyst to formulate a polymerization catalyst, it is the ratio of the amount of alkylaluminum in terms of the amount of aluminum to the amount of catalyst in terms of the amount of neodymium.

[0084] According to the present invention, the feed flow rate N of the rare earth catalyst is every time t N The value is recalculated, that is, the feed flow rate N of the rare earth catalyst is recalculated based on the above formula (1) every time interval.

[0085] According to the present invention, the above-mentioned interval time t N The residence time is 0.2-1 times the reaction residence time, which refers to the reaction time in which the monomer and catalyst coexist, and can typically be 0.5-10 hours, preferably 1-5 hours.

[0086] According to the present invention, preferably, t N The time is 0.5-3 hours, preferably 1-2.5 hours, more preferably 1.2-2 hours, and even more preferably 1.5-1.8 hours.

[0087] According to the present invention, preferably, t A The time is 0.2-2 hours, preferably 0.5-1.8 hours, and more preferably 1-1.5 hours. The t A When the value is less than the above range, there is a problem that frequent adjustments may lead to the Mooney fluctuation failing to converge due to the lag in the adjustment effect; the t A When the fluctuation exceeds the above range, there is a risk that the Mooney fluctuation may exceed the tolerance range of the post-processing equipment due to untimely adjustment.

[0088] According to a preferred embodiment of the present invention, the mixing method is not particularly limited, and those skilled in the art can use conventional mixing methods with a static mixer.

[0089] In this invention, the polymerization reaction conditions are not particularly limited, and conventional polymerization reaction conditions in the art can be used. To overcome oxygen inhibition and obtain a polymer product with a larger molecular weight, according to a preferred embodiment of the invention, the polymerization reaction is carried out in an inert atmosphere.

[0090] In this invention, the inert atmosphere refers to any gas or gas mixture that does not chemically react with reactants and products, such as nitrogen and one or more of the group 0 gases of the periodic table, preferably selected from at least one of nitrogen, helium and argon.

[0091] According to the present invention, preferably, the conditions for the polymerization reaction include: a reaction temperature of 0-200°C, preferably 20-120°C; a reaction pressure of 0-11 MPa, preferably 0-0.6 MPa; and a reaction residence time of 0-10 hours, preferably 1-5 hours.

[0092] In this invention, preferably, in order to more effectively adjust the feed flow rate of the rare earth catalyst according to the measured amount of unreacted monomer in the reactor, preferably, the monomer conversion rate and the feed flow rate of the rare earth catalyst in the polymerization process are monitored in real time.

[0093] In this invention, preferably, the initial feed flow rate of the rare earth catalyst can be calculated using the following formula.

[0094] F0=M0(1-X0)C cat ,

[0095] Where M0 is the initial unpolymerized monomer flow rate, in mol / h;

[0096] X0 represents the monomer conversion rate of the polymerization solution when it enters the reactor at time t0;

[0097] C cat The amount of catalyst required for complete monomer conversion.

[0098] In this invention, C in each formula cat It can be obtained through intermittent small-scale experiments, specifically, C cat The amount of catalyst required to completely convert a unit quantity of monomer can be determined through intermittent small-scale experiments. (C) cat It is a unitless ratio, which is the number of moles of catalyst / the number of moles of monomer.

[0099] The conditions for the intermittent pilot-scale experiment are preferably the same as those for the butadiene rubber polymerization reaction of the present invention, as described below: the reaction temperature is 0-200℃, preferably 20-120℃; the reaction pressure is 0-11MPa, preferably 0-0.6MPa; and the reaction residence time is 0-10 hours, preferably 1-5 hours. By making the conditions for the intermittent pilot-scale experiment the same as those for the butadiene rubber polymerization reaction of the present invention, the monomer conversion rate of the polymerization reaction can be controlled more accurately and effectively.

[0100] According to the present invention, in order to more effectively adjust the feed flow rate of the Mooney viscosity modifier based on the measured Mooney viscosity of the polymerization product, preferably, the Mooney viscosity of the polymerization product and the feed flow rate of the Mooney viscosity modifier during the polymerization process are monitored in real time.

[0101] In this invention, by measuring the inlet monomer conversion rate and the outlet Mooney viscosity according to the above method and calculating according to the above formula, the fluctuation range of the Mooney viscosity at the reactor outlet can be controlled within 10%, preferably within 8%, more preferably within 3%, and even more preferably within 2.5%. Preferably, for ease of operation and easier control, the polymerization reaction is preferably carried out in a polymerization reactor.

[0102] In a preferred embodiment of the invention, when the Mooney viscosity is below a set value, every t A Reduce D by 3% add Continue until the Mooney viscosity value is within ±3% of the set value, preferably within 2.5%.

[0103] In another preferred embodiment of the invention, when the Mooney viscosity is higher than a set value, every t A Increase D by 3% add Until the Mooney viscosity value is within ±10% of the set value, preferably within 8%, more preferably within 3%, and even more preferably within 2.5%.

[0104] According to a preferred embodiment of the present invention, the method includes: when the capacity of the reactor of the polymerization reactor is 1-3L, the length of the first static mixer is 0.5-1m and the diameter is 50-60mm, and the length of the second static mixer is 2-3m and the diameter is 50-60mm.

[0105] According to the present invention, the types of polymeric monomers are known to those skilled in the art and can be rationally selected according to the polymer to be prepared. For example, they can be selected from one or more of isoprene and butadiene.

[0106] According to a preferred embodiment of the present invention, the monomer-containing solution is a nickel-based polybutadiene solution, comprising a mixture of polybutadiene, a nickel-based catalyst, and butadiene monomer. Preferably, the monomer conversion rate of the nickel-based polybutadiene solution is 70-80%. Using the monomer-containing solution of the above-mentioned preferred embodiment to prepare cis-butadiene rubber helps to precisely control the monomer conversion rate during the reaction process, further improving product quality.

[0107] According to the present invention, preferably, the type and source of the catalyst are not particularly limited, and it can be commercially available or prepared by existing methods. The catalyst can be any catalyst capable of initiating the polymerization of the monomer. Preferably, the catalyst is a rare earth catalyst.

[0108] According to the present invention, preferably, the rare earth catalyst is selected from one or more of the neodymium neodecanoate catalytic system, neodymium isooctanoate catalytic system, neodymium sulfonate catalytic system, neodymium phosphonate catalytic system and neodymium isopropoxy catalytic system.

[0109] As is known to those skilled in the art, the rare earth catalyst in this invention comprises neodymium carboxylate compounds, alkyl aluminum compounds (Mooney viscosity modifiers), halogenated compounds, and conjugated dienes.

[0110] According to the present invention, preferably, the neodymium carboxylate compound in the rare earth catalyst is C1-C. 20 Neodymium carboxylate, preferably neodymium naphthenate and / or branched alkyl carboxylate. More preferably, it is selected from at least one of neodymium naphthenate, neodymium isooctanoate and neodymium neodecanoate.

[0111] According to the present invention, preferably, the alkyl compound in the rare earth catalyst that serves as a Mooney viscosity modifier is a compound having the general formula AlR3 or AlHR2, or a mixture thereof, wherein R is a C1-C6 alkyl group. Tributylaluminum and / or dibutylaluminum hydride are preferred.

[0112] The halogen-containing compound in the rare earth catalyst is an alkyl aluminum halide with the general formula AlR2X or a sesquialkyl aluminum halide with the general formula Al2R3X3, wherein R is a C1-C6 alkyl group and X is bromine or chlorine. Preferred are diethylaluminum chloride, sesquiethylaluminum chloride, or diisobutylaluminum chloride, or mixtures thereof.

[0113] The conjugated diene in the rare earth catalyst refers to any monomer having a conjugated double bond in its molecule. Preferred are butadiene, isoprene, or mixtures thereof. The conjugated diene in the catalyst may be the same as or different from the conjugated diene used as a polymerization monomer.

[0114] In this invention, preferably, the preparation method of the catalyst includes: first mixing a neodymium carboxylate compound and a conjugated diene in an organic solvent, then adding an alkylaluminum compound for aging, and finally adding a halogen-containing compound and continuing aging at 0-35°C to obtain a homogeneous transparent catalyst. The molar ratio of each component of the catalyst is neodymium carboxylate compound: alkylaluminum compound: halogen-containing compound: conjugated diene = 1:(5-10):(1-5):(8-30).

[0115] The organic solvent used in the preparation process of the rare earth catalyst described in this invention is not particularly limited. Saturated aliphatic or alicyclic hydrocarbon solvents that are inert to the reactants and are commonly used in the art can be selected, with C5-C hydrocarbons being the preferred choice. 10 Alkanes or cycloalkanes, such as pentane, isopentane, hexane, cyclohexane, heptane, octane, etc., or mixtures thereof.

[0116] According to the present invention, in addition to the alkyl compound contained in the rare earth catalyst as a Mooney viscosity modifier, a Mooney viscosity modifier is added, and is introduced into the polymerization reaction system independently and continuously as the added Mooney viscosity modifier along with the rare earth catalyst.

[0117] As the aforementioned additional Mooney viscosity modifier, it can be a substance used in the art for adjusting Mooney viscosity, preferably an alkyl aluminum compound used in the aforementioned rare earth catalyst. Preferably, the Mooney viscosity modifier is one or more of triisobutylaluminum, diisobutylaluminum hydride, and triethylaluminum.

[0118] In a preferred embodiment of the invention, the added Mooney viscosity modifier is the same compound as the alkyl compound used as the Mooney viscosity modifier in the rare earth catalyst.

[0119] According to a preferred embodiment of the present invention, the polymerization apparatus is as follows: Figure 1 As shown, a polymerization solution is supplied to the first static mixer 12 via a polymerization solution inlet line 7. A monomer conversion rate measuring unit 8 is installed on the polymerization solution inlet line 7 to measure the inlet monomer conversion rate. A rare earth catalyst is supplied to the first static mixer 12 via a rare earth catalyst line 3. A rare earth catalyst flow control unit 4 is installed on the rare earth catalyst line 3. The rare earth catalyst and polymerization solution are mixed in the first static mixer 12, and the mixture is sent to the second static mixer 13. A Mooney viscosity modifier is supplied to the second static mixer 13 via a Mooney viscosity modifier line 5. A Mooney viscosity modifier flow control unit 6 is installed on the Mooney viscosity modifier line 5. The Mooney viscosity modifier and the mixture from the first static mixer are mixed in the second static mixer 13 and fed into the reactor 1. The reactor is equipped with a stirrer 2, and the polymerization reaction is carried out under stirring conditions. The polymerization reaction product is sent to the polymerization solution outlet line 9 through the reactor outlet. A Mooney viscosity measuring unit 10 is installed on the polymerization solution outlet line 9 to measure the Mooney viscosity of the polymerization product. The feed flow rate of the rare earth catalyst and the feed flow rate of the Mooney viscosity modifier are adjusted by the control unit 11.

[0120] Accordingly, N represents the monomer conversion rate X of the polymerization solution entering the reactor, the initial unpolymerized monomer flow rate M0, and the catalyst dosage C required for complete monomer conversion, as measured by the monomer conversion measurement unit 8. cat The calculated catalyst feed flow rate; A is the Mooney viscosity of the polymerization solution at the time of exiting the reactor, measured by the Mooney viscosity measuring unit 10, and the Mooney viscosity modifier flow rate is controlled by the control unit 11 and the Mooney viscosity modifier flow control unit 6.

[0121] According to the present invention, the method of adjusting the catalyst feed rate and the Mooney viscosity modifier flow rate by means of data measured by the monomer conversion rate measurement unit and the Mooney viscosity measurement unit received by the control unit 11 is known to those skilled in the art. For example, N and A can be calculated based on the conversion rate and Mooney viscosity measured by the monomer conversion rate measurement unit and the Mooney viscosity measurement unit, combined with the above formula. The catalyst feed rate and the Mooney viscosity modifier flow rate can be manually calculated according to the above method, and the feed rate can be manually adjusted according to the calculated data; the catalyst feed rate and the Mooney viscosity modifier flow rate can also be calculated by a computer, and the automatic adjustment of the feed rate can be achieved by computer control.

[0122] The third aspect of the present invention provides a butadiene rubber prepared by the method described in the second aspect.

[0123] The present invention will be described in detail below through examples and comparative examples. Unless otherwise specified, all reagents used in the following examples and comparative examples are commercially available.

[0124] Catalyst Preparation Example 1

[0125] Under nitrogen protection, 481.3 g of hexane, 37.5 mL of 0.53 mol / L neodymium phosphonate solution, and 18.1 g of butadiene were added to a clean and dry aging vessel. After mixing, 92 mL of 2.0 mol / L monohydrodiisobutylaluminum solution was added at 50 °C and the mixture was stirred for 30 minutes. Then, the reaction vessel was cooled to 30 °C, and 22.2 mL of 2.0 mol / L diethylaluminum chloride solution was added. The reaction was then aged for another 24 hours for polymerization. The catalyst was a yellow-green transparent homogeneous phase.

[0126] In the following embodiments,

[0127] The amount of catalyst C required for complete monomer conversion in each embodiment cat The results were obtained through intermittent small-scale experiments, under the same conditions as the polymerization conditions in the same embodiment.

[0128] The polymerization reactor is as follows Figure 1As shown, a polymerization solution is supplied to the first static mixer 12 via a polymerization solution inlet line 7. A monomer conversion rate measuring unit 8 is installed on the polymerization solution inlet line 7 to measure the inlet monomer conversion rate. A rare earth catalyst is supplied to the first static mixer 12 via a rare earth catalyst line 3. A rare earth catalyst flow control unit 4 is installed on the rare earth catalyst line 3. The rare earth catalyst and polymerization solution are mixed in the first static mixer 12, and the mixture is sent to the second static mixer 13. A Mooney viscosity modifier is supplied to the second static mixer 13 via a Mooney viscosity modifier line 5. A Mooney viscosity modifier flow control unit 6 is installed on the Mooney viscosity modifier line 5. The Mooney viscosity modifier and the mixture from the first static mixer are mixed in the second static mixer 13 and fed into the reactor 1. The reactor is equipped with a stirrer 2, and the polymerization reaction is carried out under stirring conditions. The polymerization reaction product is sent to the polymerization solution outlet line 9 through the reactor outlet. A Mooney viscosity measuring unit 10 is installed on the polymerization solution outlet line 9 to measure the Mooney viscosity of the polymerization product. The feed flow rate of the rare earth catalyst and the feed flow rate of the Mooney viscosity modifier are adjusted by the control unit 11.

[0129] N represents the monomer conversion rate X of the polymerization solution entering the reactor, as measured by monomer conversion measurement unit 8; the initial unpolymerized monomer flow rate M0; and the catalyst dosage C required for complete monomer conversion. cat The calculated catalyst feed flow rate; A is the Mooney viscosity of the polymerization solution at the time of exiting the reactor, measured by the Mooney viscosity measuring unit 10, and the Mooney viscosity modifier flow rate is controlled by the control unit 11 and the Mooney viscosity modifier flow control unit 6.

[0130] Example 1

[0131] exist Figure 1 The polymerization apparatus shown is used to prepare olefin polymers, wherein the capacity of reactor 1 is 3L. The temperature of reactor 1 is controlled at 50°C and the pressure is set at 0.4MPa by a jacket. The catalyst of catalyst preparation example 1 is fed into the first static mixer 12 with a length of 1m and a diameter of 50mm through rare earth catalyst pipeline 3. The nickel-based polymerization solution (polybutadiene, nickel-based catalyst, butadiene monomer mixture, monomer conversion rate of 80%) is fed into the first static mixer 12 for mixing at a flow rate of 0.5kg / h. Diisobutylaluminum hydrogen is fed into the second static mixer 13 with a length of 2m and a diameter of 60mm through Mooney viscosity modifier pipeline 5 and mixed with the mixture from the first static mixer before being introduced into reactor 1. Then the polymerization reaction begins.

[0132] From the start of the polymerization reaction, control unit 11 (specifically the DCS system, the same below) adjusts the rare earth catalyst flow control unit 4 every 1.6 h (0.4 times the reaction residence time) and the Mooney viscosity modifier flow control unit 6 every 1.2 h (0.3 times the reaction residence time) according to the data measured by each measuring unit and according to formulas (1) and (2), so as to adjust the feed flow rates of the rare earth catalyst and Mooney viscosity modifier. After 6 hours of polymerization, a sample is taken from the material outlet, flocculated with 100 mL of ethanol, and then dried in an oven at a temperature of 50 °C and a pressure of -0.1 MPa (gauge pressure) to obtain cis-butadiene rubber.

[0133] Fifteen hours after polymerization, the Mooney viscosity of the polymer product fluctuated within 2.5%, and this fluctuation remained within 2.5% for the subsequent three months of operation.

[0134] Example 2

[0135] exist Figure 1 The polymerization apparatus shown is used to prepare olefin polymers, wherein the capacity of the reactor is 3L. The temperature of reactor 1 is controlled at 50°C and the pressure is set at 0.4MPa by a jacket. The catalyst of catalyst preparation example 1 is fed into the first static mixer 12 with a length of 1m and a diameter of 40mm through the rare earth catalyst pipeline 3. The nickel-based polymerization solution (polybutadiene, nickel-based catalyst, butadiene monomer mixture, monomer conversion rate of 75%) is fed into the first static mixer 12 for mixing at a flow rate of 0.6kg / h. Diisobutylaluminum hydrogen is fed into the second static mixer 13 with a length of 3m and a diameter of 70mm through the Mooney viscosity modifier pipeline 5. After mixing with the mixture from the first static mixer, it is introduced into reactor 1 to start the polymerization reaction.

[0136] Starting from the polymerization reaction, control unit 11 adjusts the rare earth catalyst flow control unit 4 every 1.8 hours (0.54 times the reaction residence time) and the Mooney viscosity modifier flow control unit 6 every 1 hour (0.3 times the reaction residence time) according to the data measured by each measuring unit and according to formulas (1) and (2), so as to regulate the feed flow rates of the rare earth catalyst and Mooney viscosity modifier. After 6 hours of polymerization, a sample is taken from the material outlet, flocculated with 100 mL of ethanol, and then dried in an oven at a temperature of 50°C and a pressure of -0.1 MPa (gauge pressure) to obtain cis-butadiene rubber.

[0137] After 20 hours of polymerization, the Mooney viscosity of the polymer product fluctuated within 2.5%, and this fluctuation remained within 2.5% for the subsequent three months of operation.

[0138] Example 3

[0139] exist Figure 1The polymerization apparatus shown is used to prepare olefin polymers, wherein the capacity of reactor 1 is 3L. The temperature of reactor 1 is controlled at 50°C and the pressure is set at 0.4MPa by a jacket. The catalyst of catalyst preparation example 1 is fed into the first static mixer 12 with a length of 1m and a diameter of 60mm through rare earth catalyst pipeline 3. The nickel-based polymerization solution (polybutadiene, nickel-based catalyst, butadiene monomer mixture, monomer conversion rate of 77%) is fed into the first static mixer 12 for mixing at a flow rate of 0.6kg / h. Diisobutylaluminum hydrogen is fed into the second static mixer 13 with a length of 3m and a diameter of 50mm through Mooney viscosity modifier pipeline 5. After mixing with the mixture from the first static mixer, it is introduced into reactor 1, and then the polymerization reaction begins.

[0140] From the start of the polymerization reaction, control unit 11 adjusts the rare earth catalyst flow control unit 4 every 1.2 hours (0.36 times the reaction residence time) and the Mooney viscosity modifier flow control unit 6 every 1.5 hours (0.45 times the reaction residence time) according to the data measured by each measuring unit and according to formulas (1) and (2), so as to regulate the feed flow rates of the catalyst and Mooney viscosity modifier. After 6 hours of polymerization, a sample is taken from the material outlet, flocculated with 100 mL of ethanol, and then dried in an oven at a temperature of 50°C and a pressure of -0.1 MPa (gauge pressure) to obtain cis-butadiene rubber. After 18 hours of polymerization, the Mooney viscosity fluctuation is within 2.5%, and in the subsequent three months of operation, the Mooney viscosity fluctuation remains within 2.5%.

[0141] Example 4

[0142] exist Figure 1 The polymerization apparatus shown is used to prepare olefin polymers, wherein the capacity of reactor 1 is 3L. The temperature of reactor 1 is controlled at 50°C and the pressure is set at 0.4MPa by a jacket. The catalyst of catalyst preparation example 1 is fed into the first static mixer 12 with a length of 0.5m and a diameter of 60mm through rare earth catalyst pipeline 3. The nickel-based polymerization solution (polybutadiene, nickel-based catalyst, butadiene monomer mixture, monomer conversion rate of 76%) is fed into the first static mixer 12 for mixing at a flow rate of 0.5kg / h. Diisobutylaluminum hydrogen is fed into the second static mixer 13 with a length of 2m and a diameter of 60mm through Mooney viscosity modifier pipeline 5 and mixed with the mixture from the first static mixer before being introduced into reactor 1. Then the polymerization reaction begins.

[0143] Starting from the polymerization reaction, control unit 11 adjusts the rare earth catalyst flow control unit 4 every 2.5 hours (0.62 times the reaction residence time) and the Mooney viscosity modifier flow control unit 6 every 2 hours (0.5 times the reaction residence time) based on the data measured by each measuring unit and according to formulas (1) and (2), in order to regulate the feed flow rates of the rare earth catalyst and Mooney viscosity modifier. After 6 hours of polymerization, a sample is taken from the material outlet, flocculated with 100 mL of ethanol, and then dried in an oven at a temperature of 50°C and a pressure of -0.1 MPa (gauge pressure) to obtain cis-butadiene rubber.

[0144] After 45 hours of polymerization, the Mooney viscosity fluctuation was within 3%, and during the subsequent three months of operation, the Mooney viscosity fluctuation remained within 2.5%.

[0145] Example 5

[0146] The olefin polymer was prepared according to the method of Example 1, except that the first static mixer 12 was 0.5m long and 70mm in diameter, and the second static mixer 13 was 3m long and 40mm in diameter. Other conditions were the same as in Example 1. After polymerization for 40 hours, the Mooney viscosity fluctuation was within 3%. In the subsequent three months of operation, the Mooney viscosity fluctuation remained within 3%.

[0147] Comparative Example 1

[0148] Olefin polymers were prepared according to the method of Example 1, except that the rare earth catalyst was introduced into a first static mixer 12 (0.3 m long, 40 mm diameter) via rare earth catalyst line 3. A nickel-based polymerization solution (a mixture of polybutadiene, nickel-based catalyst, and butadiene monomers with a monomer conversion rate of 80%) was fed into the first static mixer 12 for mixing. Diisobutylaluminum hydrogen was introduced into the reactor 1 after being mixed with the product from the first static mixer via a second static mixer 13 (2 m long, 50 mm diameter) through Mooney viscosity modifier line 5. Other conditions were the same as in Example 1. After 60 hours of polymerization, the Mooney viscosity fluctuation was within 3%, and during the subsequent three months of operation, the Mooney viscosity fluctuation remained within 3.5%.

[0149] Comparative Example 2

[0150] Olefin polymers were prepared according to the method of Example 1, except that the rare earth catalyst entered a first static mixer 12 (0.5 m long, 50 mm in diameter) via rare earth catalyst line 3. A nickel-based polymerization solution (a mixture of polybutadiene, nickel-based catalyst, and butadiene monomers with a monomer conversion rate of 80%) was fed into the first static mixer 12 for mixing. Diisobutylaluminum hydrogen was introduced into a second static mixer 13 (1 m long, 40 mm in diameter) via Mooney viscosity modifier line 5 and mixed with the product from the first static mixer before being introduced into reactor 1. Other conditions were the same as in Example 1. After 60 hours of polymerization, the Mooney viscosity fluctuation was within 3%, and during the subsequent three months of operation, the Mooney viscosity fluctuation remained within 3.5%.

[0151] Comparative Example 3

[0152] The olefin polymer was prepared according to the method of Example 1, except that the rare earth catalyst and monohydrodiisobutylaluminum were not passed through the first and second static mixers, but were directly introduced into the reactor. Other conditions were the same as in Example 1. After 60 hours of polymerization, the Mooney viscosity fluctuation was within 3%. In the subsequent three months of operation, the Mooney viscosity fluctuation remained within 3%.

[0153] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A polymerization reactor, characterized in that, The apparatus includes: a reaction vessel, a rare earth catalyst pipeline, a Mooney viscosity modifier pipeline, a polymerization solution inlet pipeline, a first static mixer, and a second static mixer; The outlet of the rare earth catalyst pipeline is connected to the inlet of the first static mixer for conveying the rare earth catalyst; the outlet of the polymerization solution inlet pipeline is connected to the inlet of the first static mixer for conveying the polymerization solution; the first static mixer is used to mix the rare earth catalyst and the polymerization solution, and the length of the first static mixer is not less than 0.5m. The outlet of the Mooney viscosity modifier pipeline is connected to the inlet of the second static mixer for conveying the Mooney viscosity modifier. The outlet of the first static mixer is connected to the inlet of the second static mixer. The second static mixer is used to mix the Mooney viscosity modifier with the product from the outlet of the first static mixer. The length of the second static mixer is not less than 2m. The outlet of the second static mixer is connected to the reactor for conveying the reaction raw materials into the reactor.

2. The apparatus according to claim 1, wherein, The diameter of the first static mixer is 40-70mm, preferably 50-60mm; Preferably, the length of the first static mixer is 0.5-1m; Preferably, the diameter of the second static mixer is 40-70 mm, and more preferably 50-60 mm; Preferably, the length of the second static mixer is 2-3m.

3. The apparatus according to claim 1 or 2, wherein, The rare earth catalyst pipeline is equipped with a rare earth catalyst flow control unit, which is used to adjust the feed flow rate of the rare earth catalyst. Preferably, the Mooney viscosity modifier pipeline is equipped with a Mooney viscosity modifier flow control unit for adjusting the feed flow rate of the Mooney viscosity modifier.

4. The apparatus according to any one of claims 1-3, wherein, The polymerization solution inlet pipeline is equipped with a monomer conversion rate measuring unit, which is used to measure the inlet monomer conversion rate in the polymerization solution; Preferably, the reaction vessel includes a vessel body and a jacket; Preferably, a stirrer is provided in the reactor body.

5. The apparatus according to any one of claims 1-4, wherein, The device also includes a polymerization solution outlet pipeline, and the material outlet of the reactor is connected to the inlet of the polymerization solution outlet pipeline; Preferably, a Mooney viscosity measuring unit is installed on the polymerization solution outlet pipeline for measuring the Mooney viscosity of the polymerization product; Preferably, the device further includes a control unit that adjusts the feed flow rate of the rare earth catalyst and the feed flow rate of the Mooney viscosity modifier based on the received monomer conversion rate and Mooney viscosity measurement data.

6. A method for preparing cis-butadiene rubber, characterized in that, The method is carried out in the polymerization apparatus according to any one of claims 1-5; The method includes the following steps: The polymerization solution containing the monomers enters the first static mixer through the polymerization solution inlet pipeline. The rare earth catalyst enters the first static mixer through the rare earth catalyst pipeline. After mixing in the first static mixer, the product from the first static mixer outlet enters the second static mixer. The Mooney viscosity modifier enters the second static mixer through the Mooney viscosity modifier pipeline. After mixing with the product from the first static mixer outlet, the product enters the reactor for polymerization reaction.

7. The preparation method according to claim 6, wherein, The polymerization reaction is based on adjusting the feed flow rate N of the rare earth catalyst according to the following formula (1), and adjusting the feed flow rate A of the Mooney viscosity modifier according to the measured Mooney viscosity of the polymerization product and the following formula (2). N=M(1-X)C cat (1) Where M is the unpolymerized monomer flow rate, in mol / h; X represents the monomer conversion rate of the polymerization solution when it enters the reactor; C cat The amount of catalyst required for complete monomer conversion; The feed flow rate N of the rare earth catalyst is every time t N Re-evaluate t N It is 0.2-1 times the reaction residence time. A=N(D add / D cat ) (2) Among them, D add The ratio of the amount of Mooney viscosity modifier added to the amount of catalyst (calculated as rare earth element) added to the reactor at the same time; D cat It is the ratio of the amount of Mooney viscosity modifier in the catalyst to the amount of catalyst as rare earth element. The feed flow rate A of the Mooney viscosity modifier is every time t A Re-evaluate t A It is 0.2-0.5 times the reaction residence time.

8. The method according to claim 6 or 7, wherein, When the Mooney viscosity is below the set value, every t A Reduce D by 3% add Continue until the Mooney viscosity value is within ±3% of the set value.

9. The method according to any one of claims 6-8, wherein, t N The time is 0.5-3 hours, preferably 1-2.5 hours.

10. The method according to any one of claims 6-9, wherein, t A The time is 0.2-2 hours, preferably 0.5-1.8 hours.

11. The method according to any one of claims 6-10, wherein, The conditions for the polymerization reaction include: a reaction temperature of 0-200℃, preferably 20-120℃; a reaction pressure of 0-11MPa, preferably 0-0.6MPa; and a reaction residence time of 0-10 hours, preferably 1-5 hours.

12. The method according to any one of claims 6-11, wherein, The polymeric monomer is selected from one or more of isoprene and butadiene; Preferably, the solution containing the polymeric monomer is a nickel-based polybutadiene solution; Preferably, the monomer conversion rate of the nickel-based polybutadiene solution is 70-80%.

13. The method according to any one of claims 6-12, wherein, The rare earth catalyst is selected from one or more of the following: neodymium neodecanoate catalytic system, neodymium isooctanoate catalytic system, neodymium sulfonate catalytic system, neodymium phosphonate catalytic system, and neodymium isopropoxy catalytic system; Preferably, the Mooney viscosity modifier is an alkyl aluminum compound.

14. The method according to claim 13, wherein, The Mooney viscosity modifier is one or more of triisobutylaluminum, diisobutylaluminum hydride, and triethylaluminum.

15. The cis-butadiene rubber prepared by the method according to any one of claims 6-14.

Images