Process for the polymerization of nickel-based butadiene and its applications

Abstract

This invention relates to the field of butadiene polymerization technology, and discloses a nickel-based cis-butadiene polymerization method and its application. The nickel-based cis-butadiene polymerization method of this invention includes continuously introducing a rare earth catalyst and a Mooney viscosity modifier into the polymerization reaction system under solution polymerization conditions of nickel-based cis-butadiene. The feed flow rate N of the rare earth catalyst is adjusted according to the measured amount of unreacted monomer in the reactor, and the feed flow rate A of the Mooney viscosity modifier is adjusted according to the measured Mooney viscosity of the polymerization product. The feed flow rate N of the rare earth catalyst is adjusted every time interval t. N Re-evaluate t N The feed flow rate A of the Mooney viscosity modifier is 0.2-2 times the reaction residence time, and is maintained at a rate t every time interval t. A Re-evaluate t A The reaction residence time is 0.2-0.5 times. According to the method of the present invention, the monomer conversion rate and Mooney viscosity of butadiene rubber products can be precisely controlled, improving production efficiency and enhancing product quality stability.

Description

Technical Field

[0001] This invention relates to butadiene polymerization processes, and more specifically, to a nickel-based cis-butadiene polymerization method and its application. 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, its raw material resources are abundant and inexpensive, 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 expanded with the development of the petrochemical industry and driven by the tire manufacturing sector. By 1964, its production capacity ranked second among the seven major general-purpose synthetic rubbers, second only to styrene-butadiene rubber (SBR). Currently, many countries and regions worldwide have industrial production facilities for PPB.

[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. In the early 1970s, my country also industrialized nickel-based cis-butadiene rubber using hydrogenated gasoline as a solvent and a ternary nickel system consisting of nickel naphthenate, triisobutylaluminum, and boron trifluoride diethyl ether complex, employing a nickel-aluminum aging process followed by the addition of dilute boron.

[0004] Polymerization technology is the core of NiBR production technology, and the conversion rate directly affects the product's energy and material consumption, as well as the plant's production capacity. To date, nickel-based butadiene rubber (NiBR) production technology has been industrialized in my country for over 40 years, achieving significant progress 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, it is also a harmful impurity, reacting with Al to destroy the catalyst's active sites, thus affecting the stability of the product's Mooney viscosity. Therefore, the Mooney viscosity of nickel-based butadiene rubber typically fluctuates between 40 and 50, which limits its application in more specific downstream sectors. Summary of the Invention

[0005] The purpose of this invention is to provide a nickel-based cis-butadiene polymerization method. This method adjusts the Mooney viscosity regulator feed flow rate by real-time monitoring of the Mooney viscosity of the polymerization product, which can accurately and effectively control the monomer conversion rate of the polymerization reaction. This allows for precise control of the Mooney viscosity of the cis-butadiene rubber product, thereby improving production efficiency, enhancing product quality stability, and showing great promise for industrial applications.

[0006] To achieve the above objectives, the present invention provides a nickel-based cis-butadiene polymerization method, comprising continuously introducing a rare earth catalyst and a Mooney viscosity modifier into a polymerization reaction system under solution polymerization conditions of nickel-based cis-butadiene, wherein the feed flow rate N of the rare earth catalyst is adjusted according to the measured amount of unreacted monomer in the reactor and based on the following formula (1), and the feed flow rate A of the Mooney viscosity modifier is adjusted according to the measured Mooney viscosity of the polymerization product and based on the following formula (2).

[0007] N=M(1-X)C cat (1)

[0008] Where M is the unpolymerized monomer flow rate, in mol / h;

[0009] X represents the monomer conversion rate of the polymerization solution when it enters the polymerization reactor;

[0010] C cat The amount of catalyst required for complete monomer conversion;

[0011] The feed flow rate N of the rare earth catalyst is every time t N Re-evaluate t N It is 0.2-2 times the reaction residence time.

[0012] A = N(D) add / D cat (2)

[0013] 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;

[0014] 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.

[0015] 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.

[0016] Preferably, when the Mooney viscosity is below a set value, every t A Reduce D by 5% add Continue until the Mooney viscosity value is within ±5% of the set value.

[0017] Preferably, when the Mooney viscosity is higher than a set value, every t A Increase D by 5% add Continue until the Mooney viscosity value is within ±5% of the set value.

[0018] Preferably, t N The time is 0.5-4 hours, preferably 1.5-2.5 hours.

[0019] Preferably, t A The time is 0.5-3 hours, preferably 0.8-2 hours.

[0020] 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.

[0021] Preferably, the Mooney viscosity modifier is an alkyl aluminum compound; more preferably, the Mooney viscosity modifier is one or more of triisobutylaluminum, diisobutylaluminum hydride, and triethylaluminum.

[0022] Preferably, the solution polymerization reaction conditions include: a reaction temperature of 0-200℃, a reaction pressure of 0-11MPa, and a reaction time of 0-10 hours.

[0023] Preferably, the monomer conversion rate, Mooney viscosity of the polymerization product, feed flow rate of rare earth catalyst, and feed flow rate of Mooney viscosity modifier are monitored in real time during the polymerization process.

[0024] The present invention also provides cis-butadiene rubber prepared by the nickel-based cis-butadiene polymerization method of the present invention.

[0025] This invention also provides the application of the nickel-based cis-butadiene polymerization method of this invention in the preparation of nickel-based cis-butadiene rubber.

[0026] By using the above technical solution, the Mooney viscosity of the polymerization product can be monitored in real time and the Mooney viscosity regulator feed flow rate can be adjusted accordingly. This allows for precise and effective control of the monomer conversion rate in the polymerization reaction, enabling accurate control of the Mooney viscosity of butadiene rubber products. This, in turn, improves production efficiency and enhances product quality stability, making it a promising technology for industrial applications. Attached Figure Description

[0027] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0028] Figure 1 This is a schematic diagram of the polymerization reactor provided by the present invention.

[0029] Explanation of reference numerals in the attached figures

[0030] 1-Reaction vessel; 2-Agitator; 3-Rare earth catalyst pipeline; 4-Rare earth catalyst flow control valve; 5-Mountie viscosity modifier pipeline; 6-Mountie viscosity modifier flow control valve; 7-Polymerization solution inlet pipeline; 8-Monomer conversion rate measurement unit; 9-Mountie viscosity measurement unit; 10-Polymerization solution outlet pipeline; 11-Control unit. Detailed Implementation

[0031] 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.

[0032] This invention provides a method for nickel-based cis-butadiene polymerization. The method includes continuously introducing a rare earth catalyst and a Mooney viscosity modifier into the polymerization reaction system under solution polymerization conditions of nickel-based cis-butadiene. The feed flow rate N of the rare earth catalyst is adjusted according to the measured amount of unreacted monomer in the reactor and based on the following formula (1). The feed flow rate A of the Mooney viscosity modifier is adjusted according to the measured Mooney viscosity of the polymerization product and based on the following formula (2).

[0033] N=M(1-X)C cat (1)

[0034] Where M is the unpolymerized monomer flow rate, in mol / h;

[0035] X represents the monomer conversion rate of the polymerization solution when it enters the polymerization reactor;

[0036] C cat The amount of catalyst required for complete monomer conversion;

[0037] The feed flow rate N of the rare earth catalyst is every time t N Re-evaluate t N It is 0.2-2 times the reaction residence time.

[0038] A = N(D) add / D cat (2)

[0039] 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;

[0040] 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.

[0041] 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.

[0042] In this invention, M represents the flow rate of unpolymerized monomers. Specifically, it refers to the flow rate of the polymerization solution entering the polymerization reactor, calculated based on unpolymerized monomers.

[0043] 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).

[0044] In this invention, D cat This 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.

[0045] 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.

[0046] In this invention, the aforementioned interval time t N It is 0.2-2 times the reaction residence time, which refers to the reaction time in which the monomer and catalyst coexist, and can usually be 0.5-10 hours, preferably 1-5 hours.

[0047] Specifically, the t N The time can be 0.5-4 hours, preferably 1.5-2.5 hours, more preferably 1.5-2.2 hours, and even more preferably 1.5-2 hours.

[0048] Specifically, the t A The time can be 0.5-3 hours, preferably 0.8-2 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 AWhen 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.

[0049] According to the present invention, in order to more effectively adjust the feed flow rate of the rare earth catalyst based on 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.

[0050] According to the present invention, the initial feed flow rate of the rare earth catalyst can be calculated by the following formula: F0=M0(1-X0)C cat ,

[0051] Where M0 is the initial unpolymerized monomer flow rate, in mol / h;

[0052] X0 represents the monomer conversion rate of the polymerization solution when it enters the polymerization reactor at time t0;

[0053] C cat The amount of catalyst required for complete monomer conversion.

[0054] 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.

[0055] The conditions for the batch-scale test are preferably the same as those for the nickel-based cis-butadiene polymerization method of the present invention, as described below. For example, the reaction temperature can be 0-200°C, preferably 20-120°C; the reaction pressure can be 0-11 MPa, preferably 0-0.6 MPa; and the reaction time can be 0-10 hours, preferably 1-5 hours. By making the conditions for the batch-scale test the same as those for the nickel-based cis-butadiene polymerization method of the present invention, the monomer conversion rate of the polymerization reaction can be controlled more precisely and effectively.

[0056] 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.

[0057] 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 5%, and even more preferably within 3%. Preferably, for ease of operation and control, the polymerization reaction is preferably carried out in a polymerization reactor apparatus. The polymerization reactor apparatus will be described in detail below.

[0058] In a preferred embodiment of the invention, when the Mooney viscosity is below a set value, every t A Reduce D by 5% add Continue until the Mooney viscosity value is within ±5% of the set value (preferably within 3%).

[0059] In another preferred embodiment of the invention, when the Mooney viscosity is higher than a set value, every t A Increase D by 5% add Continue until the Mooney viscosity value is within ±10% of the set value (preferably within 8%, more preferably within 5%, and even more preferably within 3%).

[0060] 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.

[0061] Those skilled in the art will understand that, in order for the monomer to undergo a polymerization reaction, the reaction system should contain a catalyst. The catalyst can be any catalyst capable of initiating the polymerization of the monomer; for example, the catalyst can be a rare earth catalyst. It is known to those skilled in the art that rare earth catalysts typically contain neodymium carboxylate compounds, alkylaluminum compounds (Mooney viscosity modifiers), halogenated compounds, and conjugated dienes.

[0062] The neodymium carboxylate compound in the rare earth catalyst is C1-C 20 Neodymium carboxylate, which may be neodymium naphthenate or branched alkyl carboxylate. Preferably, it is one or more of neodymium naphthenate, neodymium isooctanoate, and neodymium neodecanoate.

[0063] The alkyl compound in the rare earth catalyst that acts 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, dibutylaluminum hydride, or a mixture thereof are preferred.

[0064] 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.

[0065] 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.

[0066] The rare earth catalyst is prepared as follows: In an organic solvent, a neodymium carboxylate compound and a conjugated diene are first mixed, then an alkylaluminum compound is added and aged. Finally, a halogen-containing compound is added and aged further at 0–35°C to obtain a homogeneous transparent catalyst. The molar ratio of the catalyst components is neodymium carboxylate compound: alkylaluminum compound: halogen-containing compound: conjugated diene = 1:5-10:1-5:8-30.

[0067] The organic solvent used in the preparation process of the rare earth catalyst described in this invention is not particularly limited. Saturated aliphatic hydrocarbons or alicyclic hydrocarbons that are inert to the reaction components and are commonly used in the art can be selected, typically C5-C64 solvents. 10 Alkanes or cycloalkanes, such as pentane, isopentane, hexane, cyclohexane, heptane, octane, etc., or mixtures thereof.

[0068] 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.

[0069] As the aforementioned additional Mooney viscosity modifier, it can be a substance used in the art to adjust Mooney viscosity, preferably an alkyl aluminum compound used in the aforementioned rare earth catalyst.

[0070] 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.

[0071] According to the present invention, the polymerization reaction conditions can employ conventional polymerization reaction conditions in the art. However, preferably, in order to overcome oxygen inhibition and obtain a polymer product with a larger molecular weight, the polymerization reaction is carried out in an inert atmosphere. The inert atmosphere refers to any gas or gas mixture that does not chemically react with the reactants and products, such as nitrogen and one or more of the group 0 gases of the periodic table. The polymerization reaction conditions typically include reaction temperature, reaction pressure, and reaction residence time. The reaction temperature can be, for example, 0-200°C, preferably 20-120°C; the reaction pressure can be, for example, 0-11 MPa, preferably 0-0.6 MPa; and the reaction residence time can be, for example, 0-10 hours, preferably 1-5 hours.

[0072] According to the present invention, in a preferred embodiment, such as Figure 1 As shown, the polymerization reaction is carried out in a polymerization reactor, which includes a reactor 1 and a control unit 11. The reactor 1 includes a vessel body with a rare earth catalyst inlet, a material inlet, and a material outlet, and a jacket surrounding the vessel body with an inlet and an outlet. A conversion rate measuring unit 8 for measuring the monomer conversion rate at the inlet is installed on the pipeline 7 connecting the material inlet to the material source. A Mooney viscosity measuring unit 10 for measuring the Mooney viscosity is installed on the pipeline 9 connecting the material outlet to the outside. A catalyst flow measurement and control unit 4 is installed on the pipeline 3 connecting the rare earth catalyst inlet to the rare earth catalyst source. A Mooney viscosity adjustment unit 10 is also installed on the pipeline. A catalyst flow measurement and control unit 6 is installed on the pipeline 5 connecting the catalyst inlet and the Mooney viscosity modifier source; the conversion rate measurement unit 8, the Mooney viscosity measurement unit 9, the Mooney viscosity modifier flow measurement and control unit 6, and the catalyst flow measurement and control unit 4 are respectively connected to the control unit 11; the polymer preparation method includes continuously introducing the monomer solution into the reactor 1 through the material inlet and polymerizing it under the conditions of monomer solution polymerization reaction, and then flowing out from the material outlet; the control unit 11 adjusts the feed flow rate of the rare earth catalyst and the flow rate of the Mooney viscosity modifier according to the received monomer conversion rate and Mooney viscosity measurement data.

[0073] Accordingly, N represents the monomer conversion rate X of the polymerization solution entering the polymerization reactor, the initial unpolymerized monomer flow rate M0, and the catalyst dosage C required for complete monomer conversion, all measured by the 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 polymerization 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 measurement and control unit 6.

[0074] 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.

[0075] For example, an online gas chromatograph can be used as the conversion rate measurement unit mentioned above.

[0076] Mooney viscosity measurement units, such as online Mooney viscometers, can be used.

[0077] A flow measurement control unit, for example, can be a mass flow meter.

[0078] The aforementioned control unit can be, for example, a DCS system.

[0079] According to the present invention, in order to achieve more uniform mixing of materials in the reactor and obtain polymer products with better performance, the polymerization reaction apparatus preferably further includes a stirrer 2 disposed in the reactor.

[0080] The present invention also provides cis-butadiene rubber prepared by the nickel-based cis-butadiene polymerization method of the present invention.

[0081] This invention also provides the application of the nickel-based cis-butadiene polymerization method of this invention in the preparation of nickel-based cis-butadiene rubber.

[0082] According to the present invention, by adjusting the feed flow rate of the Mooney viscosity modifier by real-time monitoring of the Mooney viscosity of the polymerization product, the monomer conversion rate of the polymerization reaction can be accurately and effectively controlled, so that the Mooney viscosity of the butadiene rubber product can be precisely controlled, thereby improving production efficiency and product quality stability, and has great industrial application prospects.

[0083] The present invention will be described in detail below through embodiments, but the present invention is not limited to the following embodiments.

[0084] Catalyst preparation example

[0085] Under nitrogen protection, 521.3 g of hexane, 43.3 ml of 0.50 mol / L neodymium phosphonate solution and 23.3 g of butadiene were added to a clean and dry aging vessel. After mixing, 103 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 27.3 ml of 2.0 mol / L diethylaluminum chloride solution was added. The mixture was then aged for another 24 hours for polymerization. The catalyst was a yellow-green transparent homogeneous phase.

[0086] In the following embodiments, in Figure 1 The polymerization apparatus shown is used to prepare olefin polymers. The apparatus includes a reactor 1 and a control unit 11. The reactor 1 includes a vessel body with a rare earth catalyst inlet, a material inlet, and a material outlet, and a jacket surrounding the vessel body with inlets and outlets. A conversion rate measuring unit 8 is installed on the pipeline 7 connecting the material inlet to the material source to measure the monomer conversion rate at the inlet. A Mooney viscosity measuring unit 10 is installed on the pipeline 9 connecting the material outlet to the outside to measure the Mooney viscosity. A catalyst flow measurement and control unit 4 is installed on the pipeline 3 connecting the rare earth catalyst inlet to the rare earth catalyst source. A Mooney viscosity adjustment unit 10 is also installed. A catalyst flow measurement and control unit 6 is installed on the pipeline 5 connecting the catalyst inlet and the Mooney viscosity modifier source; the conversion rate measurement unit 8, the Mooney viscosity measurement unit 9, the Mooney viscosity modifier flow measurement and control unit 6, and the catalyst flow measurement and control unit 4 are respectively connected to the control unit 11; the polymer preparation method includes continuously introducing the monomer solution into the reactor 1 through the material inlet and polymerizing it under the conditions of monomer solution polymerization reaction, and then flowing out from the material outlet; the control unit 11 adjusts the feed flow rate of the rare earth catalyst and the flow rate of the Mooney viscosity modifier according to the received monomer conversion rate and Mooney viscosity measurement data.

[0087] Accordingly, N represents the monomer conversion rate X of the polymerization solution entering the polymerization reactor, the initial unpolymerized monomer flow rate M0, and the catalyst dosage C required for complete monomer conversion, all measured by the conversion rate 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 polymerization 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 measurement and control unit 6.

[0088] 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.

[0089] Example 1

[0090] exist Figure 1The polymerization apparatus shown is used to prepare olefin polymers, wherein the reactor has a capacity of 2L. The temperature of the reactor is controlled at 50°C and the pressure is set at 0.4MPa by a jacket. The catalyst is introduced into reactor 1 through pipeline 3 and monohydrodiisobutylaluminum through pipeline 5. The nickel-based polymerization solution (polybutadiene, nickel-based catalyst, butadiene monomer mixture, monomer conversion rate of 82%) is continuously introduced into reactor 1 through the material inlet (inlet rate of 0.6kg / h), and then polymerization begins. From the start of the polymerization reaction, the control unit 11 (specifically the DCS system, the same below) adjusts the feed flow rate regulating valve 4 every 2h (0.5 times the reaction residence time) and the feed flow rate regulating valve 6 every 1h (0.25 times the reaction residence time) according to the data measured by each measuring unit and according to formulas (1) and (2) to regulate the feed flow rate of the catalyst and Mooney viscosity modifier. Six hours after polymerization, the solution containing cis-butadiene rubber was removed from the material outlet and filtered. The filter residue was washed three times with 100 mL of ethanol and 200 mL of water, and then dried in an oven at 50 °C and -0.1 MPa (gauge pressure) to obtain cis-butadiene rubber. Twenty hours after polymerization, the Mooney viscosity fluctuation was within 3%, and this fluctuation remained within 3% for the subsequent three months of operation.

[0091] Example 2

[0092] exist Figure 1 The polymerization apparatus shown is used to prepare olefin polymers, wherein the reactor has a capacity of 2L. The temperature of the reactor is controlled at 50°C and the pressure is set at 0.4MPa by a jacket. The catalyst is introduced into reactor 1 through pipeline 3 and monohydrodiisobutylaluminum through pipeline 5. The nickel-based polymerization solution (polybutadiene, nickel-based catalyst, butadiene monomer mixture, monomer conversion rate of 71%) is continuously introduced into reactor 1 through the material inlet and polymerized (inlet rate of 0.7kg / h), and then polymerization begins. From the start of the polymerization reaction, the control unit 11 adjusts the feed flow rate regulating valve 4 every 1.5h (0.38 times the reaction residence time) and the feed flow rate regulating valve 6 every 0.8h (0.2 times the reaction residence time) according to the data measured by each measuring unit and according to formulas (1) and (2) to regulate the feed flow rate of the catalyst and Mooney viscosity modifier. Six hours after polymerization, the solution containing cis-butadiene rubber was removed from the material outlet and filtered. The filter residue was washed three times with 100 mL of ethanol and 200 mL of water. Then it was dried in an oven at 50 °C and -0.1 MPa (gauge pressure) to obtain cis-butadiene rubber. After 35 hours of polymerization, the Mooney viscosity fluctuation was within 3%. In the subsequent three months of operation, the Mooney viscosity fluctuation remained within 3%.

[0093] Example 3

[0094] exist Figure 1 The polymerization apparatus shown is used to prepare olefin polymers, wherein the reactor has a capacity of 2L. The temperature of the reactor is controlled at 50°C and the pressure is set to 0.4MPa by a jacket. The catalyst is introduced into reactor 1 through pipeline 3 and monohydrodiisobutylaluminum through pipeline 5. The nickel-based polymerization solution (polybutadiene, nickel-based catalyst, butadiene monomer mixture, monomer conversion rate of 79%) is continuously introduced into reactor 1 through the material inlet and polymerized (inlet rate of 0.65kg / h), and then polymerization begins. From the start of the polymerization reaction, the control unit 11 adjusts the feed flow rate regulating valve 4 every 2.5h (0.63 times the reaction residence time) and the feed flow rate regulating valve 6 every 1.5h (0.38 times the reaction residence time) according to the data measured by each measuring unit and according to formulas (1) and (2) to regulate the feed flow rate of the catalyst and Mooney viscosity modifier. Six hours after polymerization, the solution containing cis-butadiene rubber was removed from the material outlet and filtered. The filter residue was washed three times with 100 mL of ethanol and 200 mL of water. Then it was dried in an oven at 50 °C and -0.1 MPa (gauge pressure) to obtain cis-butadiene rubber. After 50 hours of polymerization, the Mooney viscosity fluctuation was within 3%. In the subsequent three months of operation, the Mooney viscosity fluctuation remained within 3%.

[0095] Example 4

[0096] exist Figure 1 The polymerization apparatus shown is used to prepare olefin polymers, wherein the reactor has a capacity of 2L. The temperature of the reactor is controlled at 50°C and the pressure is set to 0.4MPa by a jacket. The catalyst is introduced into reactor 1 through pipeline 3 and monohydrodiisobutylaluminum through pipeline 5. The nickel-based polymerization solution (polybutadiene, nickel-based catalyst, butadiene monomer mixture, monomer conversion rate of 71%) is continuously introduced into reactor 1 through the material inlet and polymerized (inlet rate of 0.7kg / h), and then polymerization begins. From the start of the polymerization reaction, the control unit 11 adjusts the feed flow rate regulating valve 4 every 2.2h (0.55 times the reaction residence time) and the feed flow rate regulating valve 6 every 2h (0.5 times the reaction residence time) according to the data measured by each measuring unit and according to formulas (1) and (2) to regulate the feed flow rate of the catalyst and Mooney viscosity modifier. Six hours after polymerization, the solution containing cis-butadiene rubber was removed from the material outlet and filtered. The filter residue was washed three times with 100 mL of ethanol and 200 mL of water. Then it was dried in an oven at 50 °C and -0.1 MPa (gauge pressure) to obtain cis-butadiene rubber. After 58 hours of polymerization, the Mooney viscosity fluctuation was within 3%. In the subsequent three months of operation, the Mooney viscosity fluctuation remained within 3%.

[0097] Comparative Example 1

[0098] The olefin polymer was prepared according to the method of Example 1, except that the catalyst flow rate and Mooney viscosity modifier flow rate (calculated based on an inlet monomer conversion rate of 82%) were kept constant. After 132 hours of polymerization, the Mooney viscosity fluctuation could not be controlled within 3%.

[0099] Comparative Example 2

[0100] The olefin polymer was prepared according to the method of Example 1, except that the feed flow regulating valve 4 was adjusted every 0.1 h (0.025 times the reaction residence time), and the feed flow regulating valve 6 was adjusted every 0.05 h (0.013 times the reaction residence time). After polymerization for 145 hours, the Mooney viscosity fluctuation could not be controlled within 3%.

[0101] Comparative Example 3

[0102] The olefin polymer was prepared according to the method of Example 1, except that the feed flow rate regulating valve 4 was adjusted every 6 hours (1.5 times the reaction residence time), and the feed flow rate regulating valve 6 was adjusted every 4 hours (1 time the reaction residence time). After 98 hours of polymerization, the Mooney viscosity fluctuation could not be controlled within 3%.

[0103] 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 method for nickel-based cis-butadiene polymerization, the method comprising continuously introducing a rare earth catalyst and a Mooney viscosity modifier into the polymerization reaction system under solution polymerization conditions of nickel-based cis-butadiene, characterized in that, The feed flow rate N of the rare earth catalyst is adjusted according to the measured amount of unreacted monomer in the reactor and based on the following formula (1). The feed flow rate A of the Mooney viscosity modifier is adjusted according to the measured Mooney viscosity of the polymerization product and based on 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 polymerization reactor; C cat The amount of catalyst required for complete conversion of the monomer; The feed flow rate N of the rare earth catalyst per time interval t N The value is re-taken N 0.2-2 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. The Mooney viscosity modifier is an alkyl aluminum compound.

2. The method according to claim 1, wherein, When the Mooney viscosity is below the set value, every t A Reduce D by 5% add Continue until the Mooney viscosity value is within ±5% of the set value.

3. The method according to claim 1, wherein, When the Mooney viscosity is higher than the set value, every t A Increase D by 5% add Continue until the Mooney viscosity value is within ±5% of the set value.

4. The method according to any one of claims 1-3, wherein, t N It takes 0.5-4 hours.

5. The method according to claim 4, wherein, t N It takes 1.5-2.5 hours.

6. The method according to any one of claims 1-3, wherein, t A It takes 0.5-3 hours.

7. The method according to claim 6, wherein, t A It takes 0.8-2 hours.

8. The method according to any one of claims 1-3, 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.

9. The method according to claim 1, wherein, The Mooney viscosity modifier is one or more of triisobutylaluminum, diisobutylaluminum hydride, and triethylaluminum.

10. The method according to any one of claims 1-3, wherein, The solution polymerization reaction conditions include: a reaction temperature of 20-200℃, a reaction pressure of 0-11MPa, and a reaction time of 1-10 hours.

11. The method according to any one of claims 1-3, wherein, The monomer conversion rate, Mooney viscosity of the polymerization product, feed flow rate of rare earth catalyst, and feed flow rate of Mooney viscosity modifier are monitored in real time during the polymerization process.

12. The cis-butadiene rubber prepared by the method according to any one of claims 1-11.

13. The use of the method according to any one of claims 1-11 in the preparation of nickel-based cis-butadiene rubber.

Images