Preparation method of rubber composite filler

Abstract

The invention belongs to the field of rubber industry, particularly discloses a preparation method of a rubber composite filler, and solves the problems of poor uniformity, high cost and long process time consumption of the composite filler in the prior art by optimizing the component proportion and process steps. Comprising the following steps: preparing a metal complex from aluminum citrate, ferric citrate (III) and molybdenum citrate according to a molar ratio of Al: Fe: Mo of 1: (0.3-1): (0.01-0.21), adding high-dispersion silicon dioxide (each mole of iron corresponds to 1.31-11.55 moles of silicon dioxide), then synchronously introducing the mixture and hydrocarbon raw materials into a reactor at 1200-1800 DEG C through a dual-channel nozzle, and after carbon black and carbon nanotubes are generated through pyrolysis, carrying out heat treatment on the carbon black and the carbon nanotubes, thereby obtaining the carbon black / molybdenum / carbon nanotube composite material. Chemical pure water is used for rapidly cooling to terminate the reaction, and the composite filler is obtained through separation. According to the method, the content of carbon black (63.9-96.8 wt%) and the content of carbon nanotubes (1.9-14.9 wt%) in the product are flexibly regulated and controlled by adjusting the proportion of the metal complex, the dosage of silicon dioxide and the injection volume ratio (1: 7-1: 50), and meanwhile, the process time is remarkably shortened. And the obtained filler is uniformly dispersed and is suitable for high-performance rubber production.

Description

Technical Field

[0001] The present invention belongs to the cross - field of nanomaterial preparation technology and rubber industrial composite material technology, and particularly relates to a preparation method of a rubber composite filler. Background Art

[0002] In the rubber industry, composite fillers (such as carbon black, silica, carbon nanotubes, etc.) are key components for improving the mechanical properties, wear resistance, electrical conductivity, and aging resistance of rubber. Although traditional single fillers (such as carbon black or silica) can improve some properties, it is difficult to meet the requirements of high - performance rubber for comprehensive properties. Therefore, the development of composite systems with the advantages of multiple fillers has become a research hotspot. However, the existing preparation methods of composite fillers generally face bottleneck problems such as complex processes, high costs, uncontrollable product composition, and poor dispersibility, which are specifically reflected in the following aspects:

[0003] Wet - mixing technology (such as EP4286465): This technology prepares composite fillers by wet - mixing silica, carbon black, and carbon nanotubes, dispersing them with a solvent and then drying. Although wet - mixing helps the dispersion of nano - fillers, the use of solvents increases the post - treatment cost, and filler agglomeration is likely to occur during the drying process, resulting in insufficient uniformity of the final product. In addition, the high price of carbon nanotubes and the dependence on dispersants further increase the production cost, limiting its industrial application.

[0004] Ultrasound - chemical modification method (such as CN107955224): This method modifies the surface of carbon nanotubes by ultrasonic treatment in combination with a dispersant (such as poly - N - vinylacetamide) and natural latex, and then mixes them with silica. Although modification can improve the compatibility of fillers, the introduction of natural latex increases the process complexity, and its poor thermal stability easily leads to performance deterioration of fillers during high - temperature processing. At the same time, multi - step ultrasonic dispersion, washing, and drying significantly extend the production cycle, making it difficult to meet the requirements of high - efficiency production.

[0005] Vapor - phase synthesis method (such as US2023406707): This method synthesizes carbon nanotubes by pyrolyzing carbon sources at high temperature through vapor - phase reactions and then composites them with carbon black. Although the vapor - phase method can achieve the synthesis of high - purity carbon nanotubes, the reaction conditions are harsh (such as high temperature and high pressure), the equipment investment is large, and the product composition is difficult to flexibly control (such as the fixed ratio of carbon nanotubes to carbon black), limiting its application in customized rubber formulations.

[0006] Based on this, there is an urgent need to develop a preparation method of rubber composite fillers with simple processes, controllable costs, and flexible composition adjustment to meet the requirements of high - performance rubber materials for efficient, economical, and customized production. Summary of the Invention

[0007] In view of the above problems, the present invention provides an efficient, flexible and economical method for preparing a rubber composite filler to improve the product performance and reduce the production cost.

[0008] The present invention includes the following technical solutions:

[0009] A method for preparing a rubber composite filler, comprising the following steps:

[0010] (a) Mix a metal element complex with a liquid. The metal element complex includes aluminum citrate, iron(III) citrate and molybdenum citrate, and their molar ratio is Al:Fe:Mo = 1:(0.3 - 1):(0.01 - 0.21);

[0011] (b) Add highly dispersed silica to the mixture in step (a). The addition amount is 1.31 to 11.55 moles of highly dispersed silica per 1 mole of iron atoms;

[0012] (c) Simultaneously introduce the mixture in step (b) and a hydrocarbon raw material into a reactor heated to 1200 - 1800 °C through a dual-channel nozzle to prepare a rubber composite filler; the first channel introduces the mixture of the metal element complex and highly dispersed silica, and the second channel introduces the hydrocarbon raw material;

[0013] (d) Introduce chemically pure water into the reactor for rapid cooling to terminate the growth of carbon black particles;

[0014] (e) Separate the cooled product from the gas to obtain a rubber composite filler containing highly dispersed silica, carbon black and carbon nanotubes.

[0015] Further, in the above method for preparing a rubber composite filler, in step (a), the preparation of the metal element complex includes dissolving citric acid and ammonium molybdate in deionized water to form a molybdenum citrate complex, and then adding aluminum citrate and iron(III) citrate.

[0016] Further, in the above method for preparing a rubber composite filler, in step (a), the particle size of the highly dispersed silica is 10 - 100 nm, and the specific surface area is 100 - 400 m 2 / g.

[0017] Further, in the above method for preparing a rubber composite filler, in step (c), the injection volume ratio of the dual-channel nozzle is 1:7 to 1:50, where the first channel is the mixture of the metal element complex and highly dispersed silica, and the second channel is the hydrocarbon raw material.

[0018] Further, in the preparation method of the above rubber composite filler, in step (c), the hydrocarbon raw material is selected from one or a mixture of coal tar, anthracene oil, ethylene oil or carbon black oil.

[0019] Further, in the preparation method of the above rubber composite filler, in step (c), a high-voltage electric field is provided in the synthesis zone of the reactor, and the 380V voltage is boosted through a voltage multiplier rectifier device and then applied to the inner wall of the reactor.

[0020] Further, in the preparation method of the above rubber composite filler, in step (d), in the rapid cooling step, after introducing chemical pure water, the temperature of the mixture drops from 1200 - 1800 °C to 600 - 650 °C, and is cooled to about 300 °C by secondary water injection.

[0021] Further, in the preparation method of the above rubber composite filler, in step (e), the separation step adopts one of a cyclone dust collector, a bag filter or an electrostatic precipitator.

[0022] Further, in the preparation method of the above rubber composite filler, in step (e), the content of carbon black in the final product is 63.9 wt% to 96.8 wt%, and the content of carbon nanotubes is 1.9 wt% to 14.9 wt%.

[0023] The present invention also discloses the application of the above preparation method in the production of high-performance conductive rubber.

[0024] Compared with the prior art, the present invention has the following prominent beneficial effects:

[0025] The present invention discloses a preparation method of a rubber composite filler. By optimizing the ratio of metal complexes (Al:Fe:Mo = 1:(0.3 - 1):(0.01 - 0.21)), the co - injection of a dual - channel nozzle (volume ratio 1:7 - 1:50), and the high - voltage electric field assistance process (12 kV), the performance and production efficiency of the rubber composite filler are significantly improved. Specifically, the process efficiency is enhanced. For example, in Example 4, the preparation only takes 3.0 hours, which is 65% shorter than that in Comparative Example 1 (8.5 hours), benefiting from the dual - channel synchronous feeding and rapid cooling technologies. The composition is flexibly controllable. The carbon black content can be precisely adjusted within the range of 63.9 - 96.8 wt% (such as in Example 5 and Example 4), and the carbon nanotube content can be precisely adjusted within the range of 1.9 - 14.9 wt% (such as in Example 5 and Example 9), breaking through the limitations of traditional processes (such as the fixed carbon nanotube content of 4.2 wt% in Comparative Example 1). The comprehensive performance is excellent. When the carbon nanotube content in Example 5 is 14.9 wt%, the tensile strength is increased by 45% (only 25% in Comparative Example 1). In Example 7, the conductivity of 1.5×10⁻³ S / cm is achieved through the assistance of a high - voltage electric field (10 times that of Comparative Example 2). The industrialization potential is prominent. The high - voltage electric field directional growth technology (Examples 7 - 9) can prepare fillers with a conductivity of 1.5×10⁻³ S / cm, meeting the dual requirements of high conductivity (antistatic) and high strength (tensile strength increased by 42%) for new energy vehicle tires. At the same time, the raw material cost is reduced by reducing the amount of carbon nanotubes used (only 14.9 wt% in Example 5).

[0026] In summary, the present invention takes the synergistic catalysis of metal complexes, precise ratio control by nozzles, and electric field assistance as the core innovations, solves the problems of uneven filler dispersion, complex processes, and high costs in the prior art, and provides an efficient and economical solution for the customized production of high - performance rubber products. Brief Description of the Drawings

[0027] Figure 1 Comparison of filler preparation time (I);

[0028] Figure 2 Comparison of rubber tensile strength increase (%) (I);

[0029] Figure 3 Comparison of rubber conductivity (S / cm) (I);

[0030] Figure 4 Comparison of filler preparation time (II);

[0031] Figure 5 Comparison of rubber tensile strength increase (%) (II);

[0032] Figure 6 Comparison of rubber conductivity (S / cm) (II). Detailed Description of the Invention

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] Aluminum citrate: CAS 31142-56-0, produced by City Chemical LLC, USA;

[0035] Iron(III) citrate: pentahydrate (FeC6H5O7·3.5H2O), prepared according to Patent US2005080283;

[0036] Ammonium molybdate tetrahydrate: conforming to GOST 3765-78 standard;

[0037] High-dispersion silica: particle size 10-50 nm, specific surface area 200 m 2 / g (Model Aerosil 200, produced by Evonik, Germany);

[0038] Hydrocarbon raw material: coal tar (industrial grade, provided by Sinopec);

[0039] Derivatizer: Model Q 1500D (Netzsch, Germany).

[0040] Example 1

[0041] A preparation method of a rubber composite filler:

[0042] (a) Dissolve 19.3 g of citric acid and 16.2 g of ammonium molybdate in 1 L of deionized water to form a molybdenum(VI) citrate complex; add 94.4 g of aluminum citrate (0.437 mol Al) and 142.5 g of iron(III) citrate (0.437 mol Fe), with a molar ratio of Al:Fe:Mo = 1:1:0.21.

[0043] (b) Add silica: add 78.6 g of high-dispersion silica (Aerosil 200) according to the ratio of 3 mol of silica corresponding to 1 mol of Fe.

[0044] (c) Simultaneously introduce the mixture in step (b) and the hydrocarbon raw material into a reactor heated to 1200 °C through a dual-channel nozzle to prepare a rubber composite filler; the mixture of the metal element complex and high-dispersion silica is introduced into the first channel, and the hydrocarbon raw material is introduced into the second channel; the volume ratio of the dual-channel nozzle is 1:7 (metal mixture: coal tar);

[0045] (d) Rapid cooling: Inject chemical pure water to reduce the temperature to 600 °C, and then inject water again for cooling to 300 °C.

[0046] (e) Separation: Use a bag filter to separate the products.

[0047] Test results:

[0048] Carbon black content: 87.7 wt%;

[0049] Carbon nanotube content: 7.4 wt%;

[0050] Process time: 4.2 hours.

[0051] Example 2

[0052] Preparation of metal complex:

[0053] Molar ratio of Al:Fe:Mo = 1:0.3:0.01, aluminum citrate 0.9166 mol, iron citrate 0.275 mol, molybdenum 0.09166 mol.

[0054] Add silicon dioxide: Add 11.55 mol of silicon dioxide (about 826.5 g) according to the ratio of 42 mol of silicon dioxide corresponding to 1 mol of Fe.

[0055] Reactor parameters:

[0056] Nozzle volume ratio 1:40;

[0057] Synthesis zone temperature 1800 °C.

[0058] Separation: Separate by a cyclone dust collector.

[0059] The remaining steps are the same as in Example 1.

[0060] Test results:

[0061] Carbon black content: 92.4 wt%;

[0062] Carbon nanotube content: 2.7 wt%;

[0063] Process time: 3.5 hours.

[0064] Example 3

[0065] Preparation of metal complex:

[0066] Molar ratio of Al:Fe:Mo = 1:0.5:0.10, aluminum citrate 0.6648 mol, iron citrate 0.332 mol, molybdenum 0.0665 mol.

[0067] Add silicon dioxide: Add 5.98 mol of silicon dioxide (about 428.6 g) at a ratio of 18 mol per 1 mol of Fe.

[0068] Reactor parameters:

[0069] Nozzle volume ratio 1:10;

[0070] Synthesis zone temperature 1350 °C.

[0071] The remaining steps are the same as in Example 1.

[0072] Test results:

[0073] Carbon black content: 83.7 wt%;

[0074] Carbon nanotube content: 6.5 wt%;

[0075] Process time: 4.8 hours.

[0076] Example 4

[0077] Steps:

[0078] Preparation of metal complex:

[0079] Molar ratio Al:Fe:Mo = 1:0.8:0.01, aluminum citrate 0.623 mol, iron citrate 0.499 mol, molybdenum 0.00627 mol.

[0080] Add silicon dioxide: Add 2.99 mol of silicon dioxide (about 214.0 g) at a ratio of 6 mol per 1 mol of Fe.

[0081] Reactor parameters:

[0082] Nozzle volume ratio 1:50;

[0083] Synthesis zone temperature 1450 °C.

[0084] The remaining steps are the same as in Example 1.

[0085] Test results:

[0086] Carbon black content: 96.8 wt%;

[0087] Carbon nanotube content: 1.9 wt%;

[0088] Process time: 3.0 hours.

[0089] Example 5

[0090] Preparation of metal complex:

[0091] Molar ratio of Al:Fe:Mo = 1:0.4:0.04, 0.789 mol of aluminum citrate, 0.316 mol of iron citrate, 0.03158 mol of molybdenum.

[0092] Add silicon dioxide: Add 8.84 mol of silicon dioxide (about 633.2 g) according to the ratio of 28 mol corresponding to 1 mol of Fe.

[0093] Reactor parameters:

[0094] Nozzle volume ratio 1:5;

[0095] Synthesis zone temperature 1600 °C.

[0096] The remaining steps are the same as those in Example 1.

[0097] Test results:

[0098] Carbon black content: 63.9 wt%;

[0099] Carbon nanotube content: 14.9 wt%;

[0100] Process time: 5.5 hours.

[0101] Example 6

[0102] Preparation of metal complex:

[0103] Molar ratio of Al:Fe:Mo = 1:0.6:0.08, and the remaining steps are the same as those in Example 1.

[0104] Add silicon dioxide: According to the ratio of 15 mol corresponding to 1 mol of Fe.

[0105] Reactor parameters:

[0106] Nozzle volume ratio 1:20;

[0107] Synthesis zone temperature 1500 °C.

[0108] The remaining steps are the same as those in Example 1.

[0109] Test results:

[0110] Carbon black content: 75.0 wt%;

[0111] Carbon nanotube content: 9.8 wt%;

[0112] Process time: 4.0 hours.

[0113] Example 7

[0114] A method for preparing a rubber composite filler, comprising the following steps:

[0115] (a) Dissolve 20.5 g of citric acid and 17.0 g of ammonium molybdate in 1.2 L of deionized water to form a citric acid - molybdenum complex. Add 100.0 g of aluminum citrate (0.464 mol Al) and 150.0 g of iron(III) citrate (0.464 mol Fe), with a molar ratio of Al:Fe:Mo = 1:1:0.18;

[0116] (b) Add 372.0 g of highly - dispersed silica (Aerosil 200) in a ratio of 8.0 mol of silica per 1 mol of Fe;

[0117] (c) Feed the mixture from step (b) and the hydrocarbon raw material into a reactor heated to 1550 °C simultaneously through a two - channel nozzle to prepare a rubber composite filler; the mixture of the metal element complex and highly - dispersed silica is fed through the first channel, and coal tar is fed through the second channel; a high - voltage electric field (voltage 12 kV after voltage - doubling rectification) is applied to the inner wall of the reactor;

[0118] (d) Pass in chemical pure water to cool the temperature to 650 °C, and then re - inject water to cool it to 300 °C;

[0119] (e) Separate the product using an electrostatic precipitator.

[0120] Test results:

[0121] Carbon black content: 78.5 wt%;

[0122] Carbon nanotube content: 9.2 wt%;

[0123] Process time: 4.5 hours.

[0124] Example 8

[0125] Preparation of metal complex: Molar ratio of Al:Fe:Mo = 1:0.6:0.05.

[0126] Silica ratio: 5.5 mol of silica per 1 mol of Fe.

[0127] Reactor parameters:

[0128] Nozzle volume ratio 1:25;

[0129] Synthesis zone temperature 1400 °C.

[0130] Separation: Separate using a cyclone separator.

[0131] The remaining steps are the same as in Example 7.

[0132] Test results:

[0133] Carbon black content: 85.3 wt%;

[0134] Carbon nanotube content: 6.8 wt%;

[0135] Process time: 5.0 hours.

[0136] Example 9

[0137] Preparation of metal complex: molar ratio of Al:Fe:Mo = 1:0.8:0.02, and the remaining steps are the same as in Example 7.

[0138] Proportion of silica: 11.0 mol of silica corresponds to 1 mol of Fe.

[0139] Reactor parameters:

[0140] Nozzle volume ratio 1:50;

[0141] Synthesis zone temperature 1700 °C.

[0142] The remaining steps are the same as in Example 7.

[0143] Test results:

[0144] Carbon black content: 91.2 wt%;

[0145] Carbon nanotube content: 3.1 wt%;

[0146] Process time: 3.8 hours.

[0147] Comparative Example 1

[0148] Method of Patent CN113563741

[0149] Steps:

[0150] The catalyst is a nickel compound, and the fuel is coal tar and anthracene oil (7:3);

[0151] After the carbon black core is formed by combustion, carbon nanotubes are synthesized in a high-voltage electric field (10 kV);

[0152] Rapid cooling with softened water, process time 8.5 hours.

[0153] Test results:

[0154] Carbon black content: 88.5 wt%;

[0155] Carbon nanotube content: 4.2 wt%;

[0156] Process time: 8.5 hours.

[0157] Comparative Example 2

[0158] Wet mixing method of Patent EP4286465

[0159] Steps:

[0160] Mix silica and carbon nanotubes by wet method and obtain composite filler after drying;

[0161] Process time: 6 hours (including drying step);

[0162] The dosage of carbon nanotubes is 10 wt% of the total filler.

[0163] Test results:

[0164] Carbon black content: not added;

[0165] Carbon nanotube content: 10.0 wt%.

[0166] Test Example 1

[0167] Perform performance tests on Examples 1-9 and Comparative Examples 1-2.

[0168] 1. Sample preparation: Add the compositions of Examples 1–9 and Comparative Examples 1–3 to the natural rubber matrix at 5 wt%, mix and vulcanize (150 °C × 12 minutes) to obtain rubber composites.

[0169] 2. Test standards:

[0170] 1) Tensile strength: ASTM D412, dumbbell-shaped specimen, tensile rate 500 mm / min.

[0171] 2) Rubber conductivity: Impedance analysis method

[0172] Equipment: Electrochemical workstation (CHI660E, Chenhua, Shanghai).

[0173] Steps: Sample preparation: Cut the rubber composite into a 10×10×2 mm square and coat the surface with conductive silver paste to reduce contact resistance. Test conditions: Frequency range 100 Hz - 1 MHz, amplitude 10 mV. Data processing: Fit the equivalent circuit through the Nyquist diagram, extract the bulk resistance (Rb), and conductivity σ = 1 / (Rb × sample thickness / cross-sectional area). The remaining content and dispersion uniformity use existing conventional physical and chemical methods.

[0174] The results are shown in Table 1 and Table 2, Figures 1-6 .

[0175] Table 1: Performance comparison between examples and comparative examples 1

[0176]

[0177] Table 2: Performance comparison between examples and comparative examples 2

[0178]

[0179] According to the data in Analysis Tables 1 and 2, the superiority and creativity of the preparation method of the present invention are reflected in the following aspects:

[0180] 1. Significantly improved process efficiency

[0181] Process time:

[0182] The process time of Examples 1-9 is 3.0 - 5.5 hours, significantly shorter than that of Comparative Example 1 (8.5 hours) and Comparative Example 2 (6.0 hours).

[0183] The key improvements are: the synchronous feeding design of the dual-channel nozzle reduces the reaction steps; the rapid cooling technology shortens the cooling time.

[0184] 2. Flexible and controllable composition

[0185] Content of carbon black and carbon nanotubes:

[0186] The carbon black content can be adjusted within the range of 63.9 - 96.8 wt% (such as between Example 5 and Example 4), and the carbon nanotube content can be regulated within the range of 1.9 - 14.9 wt% (such as between Example 5 and Example 9).

[0187] Comparing with Comparative Example 1: Its carbon nanotube content is fixed at 4.2 wt%, which cannot meet the diverse requirements.

[0188] 3. Comprehensive performance advantages

[0189] Improved tensile strength:

[0190] The tensile strength of Example 5 is increased by 45%, much higher than that of Comparative Example 1 (25%) and Comparative Example 2 (15%).

[0191] Reason: The high carbon nanotube content (14.9 wt%) and uniform dispersion synergistically enhance the rubber matrix.

[0192] Optimized conductivity:

[0193] The conductivity of Example 5 reaches 12.1×10 -4 S / cm, and that of Example 7 reaches 15×10 -4 S / cm, significantly higher than that of Comparative Example 1 (5.0×10 -4 S / cm).

[0194] Mechanism: The carbon nanotubes form a continuous conductive network, and the high-voltage electric field assists their directional arrangement (Example 7).

[0195] Dispersion uniformity:

[0196] The dispersibility of Examples 1, 5, and 7 is rated as "excellent", while that of Comparative Examples 1-2 is "poor".

[0197] 4. Technical breakthrough points

[0198] Synergistic catalysis of metal complexes: The Al-Fe-Mo complex induces in-situ composite of carbon black and carbon nanotubes at high temperature, avoiding the agglomeration problem of traditional wet processes.

[0199] Dual-channel nozzle design: By adjusting the volume ratio (1:7 to 1:50), the generation ratio of carbon black and carbon nanotubes can be precisely controlled.

[0200] High-voltage electric field assistance: In Examples 7-9, the electric field promotes the directional growth of carbon nanotubes and improves conductivity (for example, the conductivity in Example 7 is increased to 15×10 -4 S / cm).

[0201] Test Example 2

[0202] The following analyzes the technological progress of Examples 7-9 compared with Examples 1-6.

[0203] 1. Innovations in Examples 7-9:

[0204] High-voltage electric field assistance: A high-voltage electric field (such as 12 kV) is applied through a voltage multiplier rectifier device to promote the directional growth of carbon nanotubes on catalyst particles and improve conductivity (the conductivity in Example 7 reaches 1.5×10 -3 S / cm).

[0205] Process efficiency optimization: By adjusting the nozzle volume ratio and temperature (such as a volume ratio of 1:50 and a temperature of 1700 °C in Example 9), the process time is shortened to 3.8 hours (compared with 4.2 hours in Example 1).

[0206] Dispersibility improvement: The carbon nanotubes in Examples 7-9 are uniformly loaded on the carbon black-silica matrix, while there is agglomeration in Comparative Example 1.

[0207] 2. Limitations of Examples 1-6:

[0208] The high-voltage electric field is not introduced, and the growth of carbon nanotubes depends on pyrolysis conditions, resulting in lower conductivity under the condition of the same carbon nanotube content;

[0209] Although some parameter combinations (such as a carbon black content of 96.8% in Example 4) have controllable components, the performance improvement is limited (the tensile strength is only 25%).

[0210] It can also be more clearly concluded from Table 3.

[0211] Table 3 Performance comparison and effect verification between Examples 1-6 and Examples 7-9

[0212]

[0213] Examples 7-9 are significantly superior to Examples 1-6 in terms of process innovation (high-voltage electric field assistance), parameter optimization (accurate control of volume ratio and temperature), and performance improvement (conductivity and dispersibility), demonstrating the technical iteration and industrial application potential of the present invention. Examples 1-6, on the other hand, are for basic parameter verification, proving the wide applicability of the method.

[0214] From the perspective of application, Examples 1-6 are applicable to scenarios with flexible requirements for component ratios (such as high carbon black demand or high carbon nanotube demand). Examples 7-9 are more suitable for high-performance rubbers (such as new energy vehicle tires) that require a balance of conductivity, strength, and process efficiency.

[0215] Based on the above examples, comparative examples, and test results, the present invention achieves a technical breakthrough through the following innovations:

[0216] 1. Flexible and controllable composition: By adjusting the ratio of metal complexes, the amount of silica added, and the nozzle volume ratio, precise control of the carbon black and carbon nanotube content is achieved.

[0217] 2. Efficient and economical process: The dual-channel nozzle and rapid cooling technology significantly shorten the process time and reduce energy consumption.

[0218] 3. Comprehensive performance optimization: The uniform dispersion of carbon nanotubes and the construction of a conductive network endow the rubber material with high tensile strength and conductivity.

[0219] 4. Industrial potential: The high-voltage electric field-assisted process demonstrated in Examples 7-9 provides a feasible solution for high-performance conductive rubbers (such as new energy vehicle tires).

[0220] The above are only a limited number of preferred embodiments of the present invention, which are described in relatively specific and detailed terms, but should not be construed as limiting the scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all fall within the protection scope of the present invention.

Claims

1. A method for preparing a rubber composite filler, characterized in that: The following steps are involved: (a) mixing a metal element complex with a liquid, wherein the metal element complex comprises aluminum citrate, iron (III) citrate and molybdenum citrate, and the molar ratio thereof is Al:Fe:Mo=1:(0.3-1):(0.01-0.21); (b) adding highly dispersed silicon dioxide to the mixture of step (a), wherein the amount of highly dispersed silicon dioxide added is 1.31 mol to 11.55 mol per 1 mol of iron atom; (c) simultaneously introducing the mixture of step (b) and a hydrocarbon raw material into a reactor heated to 1200-1800° C. through a double-channel nozzle to prepare a rubber composite filler; wherein the mixture of the metal element complex and highly dispersed silica is introduced into the first channel, and the hydrocarbon raw material is introduced into the second channel; (d) introducing chemically pure water into the reactor to rapidly cool it down and stop the growth of carbon black particles; (e) separating the cooled product from the gas to obtain a rubber composite filler containing highly dispersed silica, carbon black and carbon nanotubes.

2. The preparation method according to claim 1, characterized in that: In the step (a), the preparation of the metal element complex comprises dissolving citric acid and ammonium molybdate in deionized water to form a molybdenum citrate complex, and then adding aluminum citrate and iron (III) citrate.

3. The preparation method according to claim 1, characterized in that: In the step (a), the particle size of the highly dispersed silicon dioxide is 10-100 nm, and the specific surface area is 100-400 m 2 / g.

4. The preparation method according to claim 1, characterized in that: In the step (c), the injection volume ratio of the dual-channel nozzle is 1:7 to 1:50, wherein the first channel is a mixture of metal element complex and highly dispersed silicon dioxide, and the second channel is a hydrocarbon raw material.

5. The preparation method according to claim 1, characterized in that: In the step (c), the hydrocarbon raw material is selected from one or more mixtures of coal tar, anthracene oil, ethylene oil or carbon black oil.

6. The preparation method according to claim 1, characterized in that: In the step (c), a high voltage electric field is provided in the synthesis zone of the reactor, and a voltage of 380 V is boosted by a voltage-doubling rectifier and then applied to the inner wall of the reactor.

7. The preparation method according to claim 1, characterized in that: In the step (d), in the rapid cooling step, the temperature of the mixture is reduced from 1200-1800° C. to 600-650° C. after the chemical pure water is introduced, and is then cooled to about 300° C. by secondary water injection.

8. The preparation method according to claim 1, characterized in that: In the step (e), the separation step uses one of a cyclone dust collector, a bag dust collector or an electrostatic dust collector.

9. The preparation method according to claim 1, characterized in that: In the step (e), the content of carbon black in the final product is 63.9wt% to 96.8wt%, and the content of carbon nanotubes is 1.9wt% to 14.9wt%.

10. Application of the preparation method according to any one of claims 1 to 9 in the production of high-performance conductive rubber.

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