A structurally reconstituted pyrolytic carbon black and its preparation method and apparatus

Abstract

This invention belongs to the field of solid waste recycling technology, and relates to a method and apparatus for reconstructing pyrolytic carbon black and its preparation. In a protective atmosphere at a temperature of 830–980°C, an external carbon source, pyrolytic carbon black, and an active carrier for initiating the reaction are brought into full contact for 5–12 seconds to obtain modified pyrolytic carbon black. This modified carbon black is then treated with a plasma discharge power of 200–400W at a temperature of 450–550°C for 1–3 minutes. Finally, it is immersed in an acidic solution of 4–9 mol / L for 5–15 minutes. The carbon source can be any one of gaseous hydrocarbons, high-carbon polymers, or thermosetting resins; the active carrier for initiating the reaction is a copper foil carrier. Using this method and apparatus, an external carbon source is solidified onto the surface of pyrolytic carbon black under high-temperature conditions, forming new porous structures and chemical functional groups, reshaping the structure and surface microchemical environment of the pyrolytic carbon black, and increasing the bonding performance between the pyrolytic carbon black and rubber composite materials.

Description

Technical Field

[0001] This invention belongs to the field of solid waste recycling technology, specifically relating to a structural remodeling pyrolytic carbon black and its preparation method and apparatus. In particular, it remodels the structure and surface microchemical environment of pyrolytic carbon black obtained from the pyrolysis of waste tires, thereby increasing the bonding performance between pyrolytic carbon black and rubber composite materials. Background Technology

[0002] With the continuous increase in my country's car ownership, the annual output of waste tires is increasing year by year, causing serious waste of energy resources and environmental pollution. Pyrolysis can convert waste tires into aromatic oils, high-fuel-value gases, and reusable carbon black and steel wire, achieving maximum energy recovery and resource reuse of waste tires. It is currently the most effective way to recycle waste tires, offering advantages such as large processing capacity, high economic benefits, and low pollution compared to other final disposal methods. Currently, some countries in the United States and Europe have banned incineration, landfill, and stockpiling, allowing only pyrolysis, considering it the most effective and thorough treatment method.

[0003] Pyrolytic carbon black is the second largest byproduct of waste tire pyrolysis, accounting for approximately 30-35%. Its composition is highly complex, mainly containing fillers (carbon black, silica) added during tire manufacturing, vulcanizing auxiliaries (zinc oxide), and reaction derivatives generated during pyrolysis (zinc oxide reacts with sulfur to form zinc sulfide and other substances). It contains many impurities and has low activity, exhibiting disadvantages compared to industrially produced carbon black, such as larger particle size, lower structure, and lower surface activity, making it unusable in the production of new tires. Therefore, pyrolytic carbon black needs to be modified before reuse.

[0004] Numerous methods exist for the activation and modification of pyrolytic carbon black, with numerous patent reports. However, these methods primarily involve impurity removal and activation of the already obtained pyrolytic carbon black. While the strength of the treated pyrolytic carbon black is improved to some extent when used in the preparation of rubber composites, its 300% tensile strength remains very low, failing to meet the requirements for tire use. The 300% tensile strength is closely related to the structure of the pyrolytic carbon black itself; the higher the structure, the greater the 300% tensile strength. Based on the correlation between material properties and material structure, it is clear that current methods and processes for treating pyrolytic carbon black have failed to fundamentally solve the problem of its low structure. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned problems existing in the prior art. It proposes a structural remodeling pyrolytic carbon black and its preparation method and apparatus. Under high temperature conditions, the present invention solidifies an external carbon source onto the surface of pyrolytic carbon black to form a new pore structure and chemical functional groups, remodels the structure and surface microchemical environment of pyrolytic carbon black, and increases the bonding performance of pyrolytic carbon black with rubber composite materials.

[0006] The technical solution of this invention is:

[0007] This invention provides a method for preparing reconstructed pyrolytic carbon black. The method involves solidifying an external carbon source onto the surface of pyrolytic carbon black under specific temperature conditions to form new pore structures and chemical functional groups, thereby reshaping the structure and surface microchemical environment of the pyrolytic carbon black. The method includes the following steps:

[0008] S1: In a protective atmosphere, the temperature is set to 830-980℃. The external carbon source, pyrolytic carbon black and the active carrier for initiating the reaction are fully contacted for 5-12 seconds. New pore structures are grown on the surface of the pyrolytic carbon black, changing the morphology of the primary particles of the pyrolytic carbon black and forming new chemical functional groups on the surface of the pyrolytic carbon black, thus obtaining modified pyrolytic carbon black.

[0009] The number of chemical functional groups on the surface of modified pyrolytic carbon black in step S1 is mainly related to the residence time of the carbon source on the surface of the pyrolytic carbon black. Functional groups will only form on the surface of the pyrolytic carbon black if the carbon source is in full contact with it (the optimal residence time is 2-5 seconds). The carbon sources used in this invention include both gaseous and solid carbon sources. When the carbon source is in gaseous form, it is only necessary to raise its temperature to a certain condition to allow it to decompose and react with the pyrolytic carbon black. However, when the carbon source is in solid form, it needs to decompose first to generate a gaseous carbon source before reacting with the pyrolytic carbon black. This stepwise reaction process takes time, so it will be longer than the 2-5 second residence time. Therefore, the reaction time is set to 5-12 seconds.

[0010] The above reaction temperature is any temperature value within the range of 830 to 980℃, such as 830℃, 850℃, 870℃, 880℃, 890℃, 895℃, 900℃, 910℃, 920℃, 925℃, 940℃, 950℃, 970℃, or 980℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0011] The contact time can be any value within the range of 5 to 12 seconds, such as 5s, 6s, 7s, 8s, 9s, 10s, 11s, or 12s, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0012] S2: The modified pyrolytic carbon black is treated at a temperature of 450-550℃ with a plasma discharge power of 200-400W for 1-3 minutes; step S2 improves the ordered distribution characteristics of the carbon structure through local oxidation and etching, increases its activity, and enriches its surface active functional groups.

[0013] S3: Place the treated modified pyrolytic carbon black in an acidic solution with a concentration of 4-9 mol / L and soak for 5-15 minutes;

[0014] The concentration of the acidic solution can be any value in the range of 4 to 9 mol / L, such as 4 mol / L, 5 mol / L, 6 mol / L, 7 mol / L, 8 mol / L, or 9 mol / L, but is not limited to the listed values. Other unlisted values ​​in this range are also applicable.

[0015] Soaking time can be any time within the range of 5 to 15 minutes, such as 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, or 15 minutes, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0016] S4: Drying;

[0017] S5: By thoroughly mixing supercritical carbon dioxide with reconstructed pyrolytic carbon black and spraying it out with a special nozzle, the particle size of the pyrolytic carbon black is refined through the strong high-frequency pulsating shear force field formed by the rapid expansion of supercritical carbon dioxide, and finally reconstructed pyrolytic carbon black is obtained.

[0018] The carbon source is any one of gaseous hydrocarbons, high carbon content polymers, or thermosetting resins.

[0019] The initiating reactive support is a copper foil support. It should be noted that under different initiating reactive support conditions, the method of this invention will produce modified pyrolytic carbon black with completely different properties. The formation of new chemical functional groups on the surface of the pyrolytic carbon black of this invention is achieved under the condition of an initiating reactive support mainly composed of copper foil. If other initiating reactive support systems are used, different types of chemical functional groups will be formed.

[0020] The present invention uses the above-mentioned preparation method to solidify an external carbon source onto the surface of pyrolytic carbon black, grow a new pore structure on the surface of pyrolytic carbon black, change the morphology of primary particles of pyrolytic carbon black, and form new chemical functional groups on the surface of pyrolytic carbon black.

[0021] Furthermore, the protective atmosphere is selected from inert gas atmospheres, including nitrogen and argon;

[0022] The gaseous hydrocarbons are selected from those with a carbon content of more than 90%, including methane;

[0023] The high carbon content polymer includes any one or a mixture of several of polyethylene, polypropylene, and polystyrene.

[0024] Furthermore, when the carbon source is gaseous hydrocarbon, the gaseous hydrocarbon is continuously introduced at an inlet rate of 20 ml / min. Under the protection of argon atmosphere, the gaseous hydrocarbon, pyrolytic carbon black and the active carrier for initiating the reaction are brought into full contact for 5 to 10 seconds at a heating rate of 10 to 15 K / min and a final temperature of 900 to 950 °C.

[0025] The heating rate can be any rate within the range of 10 to 15 K / min, such as 10 K / min, 11 K / min, 12 K / min, 13 K / min, 14 K / min, or 15 K / min, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The optimal heating rate is 13 K / min.

[0026] The preferred reaction temperature is 930℃.

[0027] The contact time can be any value within the range of 5 to 10 seconds, such as 5 seconds, 6 seconds, 7 seconds, 8 seconds, 9 seconds, or 10 seconds, but is not limited to the listed values. Other unlisted values ​​within this range also apply. The optimal contact time is 8 seconds.

[0028] When the carbon source is a high carbon content polymer, the mass ratio of the high carbon content polymer to pyrolytic carbon black is 1.5 to 2:100. Under an argon protective atmosphere, at a heating rate of 5 to 10 K / min, and at a final temperature of 830 to 880 °C, the pyrolytic carbon black is brought into full contact with the decomposition products of the high carbon content polymer and the reactive carrier for 8 to 12 seconds.

[0029] The mass ratio of 1.5 to 2:100 mentioned above can be 1.5:100, 1.6:100, 1.7:100, 1.8:100, 1.9:100 or 1:50, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] The heating rate can be any rate within the range of 5 to 10 K / min, such as 5 K / min, 6 K / min, 7 K / min, 8 K / min, 9 K / min, or 10 K / min, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The optimal heating rate is 8 K / min.

[0031] The preferred reaction temperature is 850℃.

[0032] The contact time can be any value within the range of 8 to 12 seconds, such as 8, 9, 10, 11, or 12 seconds, but is not limited to the listed values. Other unlisted values ​​within this range also apply. The optimal contact time is 10 seconds.

[0033] When the carbon source is a thermosetting resin, the mass ratio of thermosetting resin to pyrolytic carbon black is 2.5 to 3.5:100. Under a nitrogen protective atmosphere, at a heating rate of 2 to 5 K / min, and with a final temperature of 950 to 980 °C, the pyrolytic carbon black is brought into full contact with the decomposition products of the thermosetting resin and the reactive carrier for 5 to 8 seconds.

[0034] The mass ratio of 2.5 to 3.5:100 mentioned above can be 2.5:100, 2.6:100, 2.7:100, 2.8:100, 2.9:100, 3.0:100, 3.1:100, 3.2:100, 3.3:100, 3.4:100, or 3.5:100, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] The heating rate can be any rate within the range of 2 to 5 K / min, such as 2 K / min, 3 K / min, 4 K / min, or 5 K / min, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The optimal heating rate is 3 K / min.

[0036] The preferred reaction temperature is 970℃.

[0037] The contact time can be any value within the range of 5 to 8 seconds, such as 5 seconds, 6 seconds, 7 seconds, or 8 seconds, but is not limited to the listed values. Other unlisted values ​​within this range also apply. The optimal contact time is 7 seconds.

[0038] Furthermore, in step S1, the added carbon source is solidified onto the surface of pyrolytic carbon black to form chemical functional groups. The formation of new chemical functional groups on the surface of pyrolytic carbon black is closely related to the form and structure reconstruction process of the carbon source. When gaseous hydrocarbons are used as carbon sources, under the above reaction conditions, the functional groups are mainly hydroxyl groups. When high carbon content polymers are used as carbon sources, under the above reaction conditions, the functional groups are mainly hydroxyl and amide groups. When thermosetting resins are used as carbon sources, under the above reaction conditions, the functional groups are mainly hydroxyl and aromatic groups.

[0039] Furthermore, step S2 involves localized oxidation of the modified pyrolytic carbon black, specifically, the modified pyrolytic carbon black undergoes plasma-enhanced surface carbon source structure at a certain temperature; this includes:

[0040] Modified pyrolytic carbon black was treated at 450℃ with a plasma discharge power of 200W for 3 minutes; or,

[0041] Modified pyrolytic carbon black was treated at 500℃ with a plasma discharge power of 300W for 2 minutes; or,

[0042] Modified pyrolytic carbon black was treated at 550℃ with a plasma discharge power of 400W for 1 minute.

[0043] Furthermore, in step S3, the modified pyrolytic carbon black is etched, and the acidic solution is one or both of sulfuric acid and hydrofluoric acid.

[0044] Under sulfuric acid conditions, the concentration is 5–9 mol / L, and the soaking time is 10–15 min; preferably, the optimal concentration is 7 mol / L, and the optimal soaking time is 12 min.

[0045] Under hydrofluoric acid conditions: the concentration is 4-7 mol / L, and the soaking time is 5-10 min; preferably, the optimal concentration is 5 mol / L and the optimal soaking time is 7 min.

[0046] After new chemical functional groups are formed on the surface of pyrolytic carbon black, the ordered distribution characteristics of the carbon structure can be improved, its activity can be increased, and its surface active functional groups can be enriched through the aforementioned local oxidation and etching processes.

[0047] The present invention also provides a structurally reconstituted pyrolytic carbon black prepared by any of the preparation methods described above.

[0048] The method for preparing reconstructed pyrolytic carbon black provided by this invention, under the influence of multiple external fields, controls the size of the pore structure, growth thickness, and types and quantities of surface chemical functional groups of pyrolytic carbon black by adjusting and optimizing the ratio of pyrolytic carbon black to added carbon source, controlling the reaction atmosphere, optimizing the reaction temperature, adjusting the reaction time, and optimizing the oxidation and etching conditions.

[0049] The aforementioned external multi-field enhancement refers to the introduction of multiple fields such as magnetic fields, ultrasound, and plasma during the pyrolysis carbon black treatment process. This activates the gas surrounding the surface of the pyrolysis carbon black, alters the aggregation state evolution of the pyrolysis carbon black, and thus enhances the structural reshaping effect of the pyrolysis carbon black.

[0050] The aforementioned multi-process parameter control involves adjusting the pyrolytic carbon black structure remodeling process parameters based on the performance requirements of the target product, pyrolytic carbon black, such as its structure degree, aggregated structure, chemical composition, surface morphology, and surface chemical group properties.

[0051] The performance requirements of the target product, pyrolytic carbon black, are mainly achieved by adjusting the ratio of pyrolytic carbon black to external carbon source, the reaction atmosphere, and the reaction temperature process parameters.

[0052] The performance requirements of the aggregated structure of the target product, pyrolytic carbon black, are mainly determined by process parameters such as reaction time, reaction atmosphere, reaction temperature, and local oxidation and etching conditions.

[0053] The performance requirements of the chemical composition of the target product, pyrolytic carbon black, are mainly achieved by adjusting the ratio of pyrolytic carbon black to external carbon source, reaction atmosphere, and reaction temperature process parameters.

[0054] The performance requirements of the surface morphology of the target product, pyrolytic carbon black, are mainly achieved by adjusting the process parameters such as reaction time, reaction temperature, local oxidation, and etching conditions.

[0055] The performance requirements of the surface chemical group properties of the target product, pyrolytic carbon black, are mainly achieved by adjusting the process parameters of local oxidation and etching conditions.

[0056] Furthermore, the reconstituted pyrolytic carbon black is mixed with rubber to prepare a reconstituted pyrolytic carbon black rubber composite material.

[0057] In order to increase the bonding performance of pyrolytic carbon black and rubber composite materials, this invention also needs to be combined with the preparation and mixing process of structural reconstituted pyrolytic carbon black rubber composite materials. During the mixing process, the small ingredients need to be added first according to the composite material formula, then rubber, then silica, and then structural reconstituted pyrolytic carbon black and processing oil are added to the mixing system. After the mixing temperature reaches 155°C, the glue is discharged and cooled.

[0058] The present invention also provides an apparatus for implementing the preparation method described in any of the above claims, characterized in that the apparatus comprises a continuously feeding extruder, an apparatus body, and a continuously discharging extruder connected in sequence; a transmission assembly and a bearing assembly are fixedly mounted on the apparatus body; the apparatus body includes a housing, on which an electric heating coil is mounted; a conveying assembly and a protective gas channel are provided inside the housing; the conveying assembly is made of copper foil material; the protective gas channel is installed at a position slightly above the middle of the conveying assembly; the continuously feeding extruder is inserted into the apparatus body and extends directly above the conveying assembly; a main drive wheel and a driven drive wheel are respectively provided at both ends of the conveying assembly; the transmission assembly drives the bearing assembly and the main drive wheel of the conveying assembly to rotate, thereby driving the conveying assembly and the driven drive wheel of the conveying assembly to rotate at a uniform speed; the apparatus also includes a sealing assembly.

[0059] Furthermore, the continuous discharge extruder is fixedly connected to the main body of the device and forms a 45-degree angle with the shell;

[0060] The housing is also provided with a protective gas inlet and a protective gas outlet, which are respectively connected to both ends of the protective gas channel;

[0061] The protective gas channel is installed at a position 20% above the middle of the delivery assembly;

[0062] A sealing assembly is provided at the position where the housing mates with the main drive wheel and the driven drive wheel of the conveying assembly. The sealing assembly includes a housing sidewall, a drive wheel central shaft, and a sealing ring that is interference-fitted with the drive wheel central shaft. The sealing ring has a U-shaped structure, and its sealing working plane extends 1-2 mm beyond the working surface of the drive wheel central shaft. A static sealing upper ring and a static sealing lower ring are provided at the mating position between the housing sidewall and the sealing ring. Both the static sealing upper ring and the static sealing lower ring are circular rings, with the static sealing upper ring being 10 mm longer than the static sealing lower ring. A sealing ring is provided between the sealing ring and the static sealing upper ring and the static sealing lower ring. The sealing assembly also includes a lubricating oil port.

[0063] The beneficial effects of this invention are:

[0064] This invention solidifies an external carbon source onto the surface of pyrolytic carbon black under high-temperature conditions, forming new pore structures and chemical functional groups. This reshapes the structure and surface microchemical environment of the pyrolytic carbon black, increasing the bonding performance between pyrolytic carbon black and rubber composites. Furthermore, based on the performance requirements of the rubber composites, under the influence of multiple external fields, the size, growth thickness, and types and quantities of surface chemical functional groups of the pyrolytic carbon black surface can be controlled through various process parameters, including adjusting and optimizing the ratio of pyrolytic carbon black to external carbon source, controlling the reaction atmosphere, optimizing the reaction temperature, adjusting the reaction time, and optimizing local oxidation and etching conditions. A complete set of pyrolytic carbon black structure reconstruction equipment has been developed and is currently undergoing industrial-scale application.

[0065] This invention realizes the transformation of the tire life cycle from a linear "resource-product-waste" model to a circular "resource-product-recycled resource" model, which is of great significance for promoting my country's ecological civilization construction and building a resource-saving and environmentally friendly society. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the device structure provided by the present invention;

[0067] Figure 2 A cross-sectional view of the device structure provided by the present invention;

[0068] Figure 3 This is a schematic diagram of the sealing assembly provided by the present invention;

[0069] In the above figures, Ⅰ, continuous feed extruder; Ⅱ, device body; Ⅲ, continuous discharge extruder; Ⅳ, frame; 1, sealing assembly; 2, protective gas inlet; 3, protective gas outlet; 4, bearing assembly; 4-1, sealing ring; 4-2, sealing ring; 4-3, static seal upper ring; 4-4, static seal lower ring; 5, transmission assembly; 6, housing; 6-1, housing side wall; 6-2, lubricating oil port; 7, protective gas passage; 8, conveying assembly; 9, conveying assembly main drive wheel; 9-1, drive wheel central shaft; 10, conveying assembly driven drive wheel. Detailed Implementation

[0070] The technical solution of the present invention will now be clearly and completely described with reference to specific embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] Example 1

[0072] In this embodiment, gaseous hydrocarbons are used as the carbon source to restructure pyrolytic carbon black under these conditions.

[0073] (1) The structural reconstruction process of pyrolytic carbon black:

[0074] S1: In the process of reconstructing the structure of pyrolytic carbon black, methane is used as the carbon source. The methane is continuously introduced into the reaction device at an inlet flow rate of 20 ml / min. Under the protective atmosphere of argon, the temperature is increased at a rate of 13 K / min, and the final temperature is 950℃. The methane and pyrolytic carbon black are brought into full contact on a copper foil carrier for 10 seconds.

[0075] S2: The modified pyrolytic carbon black produced in step S1 is treated at 450℃ with a plasma discharge power of 200W for 3 minutes.

[0076] S3: Immerse the modified pyrolytic carbon black treated in step S2 in sulfuric acid with a concentration of 7 mol / L for 12 min.

[0077] S4: Dry the modified pyrolytic carbon black prepared in step S3.

[0078] (2) Preparation process of structural reconstruction pyrolytic carbon black rubber composite material:

[0079] S1: Modified pyrolytic carbon black prepared by pyrolytic carbon black structural reconstruction is weighed according to the requirements of the rubber composite material formulation; the formulation components and proportions are shown in Table 1 below:

[0080] Table 1. Names and quantities of each component in the formula.

[0081]

[0082]

[0083] S2: The mixing process parameters are set as follows:

[0084] The mixing chamber temperature is 60℃, the rotation speed is 60r / min, the filling coefficient is 0.65, and the pressure of the top plug is 0.7MPa;

[0085] S3: The mixing process is as follows:

[0086] First, add rubber and mix for 40 seconds. Then, add zinc oxide (ZnO), stearic acid (SAD), accelerator 4020, antioxidant RD, microcrystalline wax, and plasticizer A. After mixing for 40 seconds, add coupling agent Si69 and precipitated silica. After mixing for 40 seconds, slowly and in multiple batches, add pyrolysis carbon black and processing oil. After mixing for 40 seconds, lift the plug and finally mix to 155°C for degassing.

[0087] S4: The rubber compound obtained from S3 is pressed into sheets and vulcanized, and then the properties of the rubber compound are tested.

[0088] (3) Test Experiment Results

[0089] Table 1 Performance test data of reconstituted pyrolytic carbon black

[0090] project Pyrolytic carbon black Reconstructed pyrolytic carbon black <![CDATA[Iodine absorption value / g·kg -1 > 85 140 <![CDATA[DBP oil absorption value / 10 -5 m 3 .kg -1 > 90 100 <![CDATA[Nitrogen adsorption specific surface area (NSA) / 10 3 m 2 .kg -1 > 26.87 46.3 Add / subtract calories / % 3.02 0.05 Detailed content / % 40.6 7.26 Particle hardness 51 45.5 325 mesh screen residue / % 0.05 0.05

[0091] Table 2 Performance Analysis of Rubber Composite Materials

[0092] Pyrolytic carbon black rubber composite material Structural Reconstruction of Pyrolytic Carbon Black Rubber Composite Materials hardness 54.5 58.3 100% fixed stretch 1.82 2.88 200% fixed stretch 5.14 8.26 300% fixed stretch 10.78 13.55 tensile strength 22.94 22.38 Elongation at break 476.77 501.08 Tensile volume 10933 11214

[0093] Example 2

[0094] In this embodiment, a high-carbon-content polymer is used as the carbon source to restructure pyrolytic carbon black under these conditions.

[0095] (1) The structural reconstruction process of pyrolytic carbon black:

[0096] S1: In the process of reconstructing the structure of pyrolytic carbon black, polyethylene is used as the carbon source. Under the protection of argon gas, the pyrolytic carbon black with a mass ratio of 1.8:100 and the decomposition products of polyethylene are fully contacted on a copper foil carrier for 10 seconds at a heating rate of 8K / min and a final temperature of 850℃.

[0097] S2: The modified pyrolytic carbon black produced in step S1 is treated at 500℃ with a plasma discharge power of 300W for 2 minutes.

[0098] S3: Immerse the modified pyrolytic carbon black treated in step S2 in sulfuric acid with a concentration of 7 mol / L for 12 min.

[0099] S4: Dry the modified pyrolytic carbon black prepared in step S3.

[0100] (2) Preparation process of structural reconstruction pyrolytic carbon black rubber composite material:

[0101] S1: The modified pyrolytic carbon black prepared by pyrolytic carbon black structural reconstruction is weighed according to the requirements of the rubber composite material formulation; the formulation components and proportions are shown in Table 1 of Example 1.

[0102] S2: The mixing process parameters are set as follows:

[0103] The mixing chamber temperature is 60℃, the rotation speed is 60r / min, the filling coefficient is 0.65, and the pressure of the top plug is 0.7MPa;

[0104] S3: The mixing process is as follows:

[0105] First, add rubber and mix for 40 seconds. Then, add zinc oxide (ZnO), stearic acid (SAD), accelerator 4020, antioxidant RD, microcrystalline wax, and plasticizer A. After mixing for 40 seconds, add coupling agent Si69 and precipitated silica. After mixing for 40 seconds, slowly and in multiple batches, add pyrolysis carbon black and processing oil. After mixing for 40 seconds, lift the plug and finally mix to 155°C for degassing.

[0106] S4: The rubber compound obtained from S3 is pressed into sheets and vulcanized, and then the properties of the rubber compound are tested.

[0107] (3) Test Experiment Results

[0108] Table 3 Performance test data of reconstituted pyrolytic carbon black

[0109] project Pyrolytic carbon black Reconstructed pyrolytic carbon black <![CDATA[Iodine absorption value / g·kg -1 > 85 152 <![CDATA[DBP oil absorption value / 10 -5 m 3 .kg -1 > 90 105 <![CDATA[Nitrogen adsorption specific surface area (NSA) / 10 3 m 2 .kg -1 > 26.87 42.9 Add / subtract calories / % 3.02 0.07 Detailed content / % 40.6 9.26 Particle hardness 51 47.6 325 mesh screen residue / % 0.05 0.05

[0110] Table 4 Performance Analysis of Rubber Composite Materials

[0111]

[0112]

[0113] Example 3

[0114] In this embodiment, thermosetting resin is used as a carbon source to restructure pyrolytic carbon black under these conditions.

[0115] (1) The structural reconstruction process of pyrolytic carbon black:

[0116] S1: In the process of reconstructing the structure of pyrolytic carbon black, using acrylic resin as the carbon source, under a nitrogen protective atmosphere, with a heating rate of 3K / min and a final temperature of 980℃, the pyrolytic carbon black and the decomposition products of acrylic resin with a mass ratio of 3:100 are fully contacted on a copper foil carrier for 8 seconds.

[0117] S2: The modified pyrolytic carbon black produced in step S1 is treated at 550℃ with a plasma discharge power of 400W for 1 minute.

[0118] S3: Immerse the modified pyrolytic carbon black treated in step S2 in sulfuric acid with a concentration of 7 mol / L for 12 min.

[0119] S4: Dry the modified pyrolytic carbon black prepared in step S3.

[0120] (2) Preparation process of structural reconstruction pyrolytic carbon black rubber composite material:

[0121] S1: The modified pyrolytic carbon black prepared by pyrolytic carbon black structural reconstruction is weighed according to the requirements of the rubber composite material formulation; the formulation components and proportions are shown in Table 1 of Example 1.

[0122] S2: The mixing process parameters are set as follows:

[0123] The mixing chamber temperature is 60℃, the rotation speed is 60r / min, the filling coefficient is 0.65, and the pressure of the top plug is 0.7MPa;

[0124] S3: The mixing process is as follows:

[0125] First, add rubber and mix for 40 seconds. Then, add zinc oxide (ZnO), stearic acid (SAD), accelerator 4020, antioxidant RD, microcrystalline wax, and plasticizer A. After mixing for 40 seconds, add coupling agent Si69 and precipitated silica. After mixing for 40 seconds, slowly and in multiple batches, add pyrolysis carbon black and processing oil. After mixing for 40 seconds, lift the plug and finally mix to 155°C for degassing.

[0126] S4: The rubber compound obtained from S3 is pressed into sheets and vulcanized, and then the properties of the rubber compound are tested.

[0127] (3) Test Experiment Results

[0128] Table 5 Performance test data of reconstituted pyrolytic carbon black

[0129]

[0130]

[0131] Table 6 Performance Analysis of Rubber Composite Materials

[0132] Pyrolytic carbon black rubber composite material Structural Reconstruction of Pyrolytic Carbon Black Rubber Composite Materials hardness 54.5 65.5 100% fixed stretch 1.82 4.20 200% fixed stretch 5.14 9.85 300% fixed stretch 10.78 18.65 tensile strength 22.94 24.89 Elongation at break 476.77 488.28 Tensile volume 10933 12153

[0133] The experimental data above clearly show that the performance of the reconstituted pyrolytic carbon black rubber composite material prepared by the present invention far exceeds that of the traditional pyrolytic carbon black rubber composite material, and the 300% elongation reaches 18.65 MPa, which meets the performance requirements of passenger car tire tread rubber.

[0134] Example 4

[0135] This embodiment provides an apparatus for preparing structurally reconstituted pyrolytic carbon black, such as... Figure 1 and 2 As shown, the device includes a continuous feed extruder I, a device body II, and a continuous discharge extruder III connected in sequence, and also includes a support frame IV.

[0136] The device body II includes a housing 6, on which an electric heating coil for heating and maintaining temperature is mounted. Inside the housing 6, a conveying assembly 8 and a protective gas channel 7 are disposed. The protective gas channel 7 is installed at a position slightly above the center of the conveying assembly 8; in one specific embodiment, the protective gas channel 7 is installed at a position 20% above the center of the conveying assembly 8. Furthermore, the housing 6 is also provided with a protective gas inlet 2 and a protective gas outlet 3, which are respectively connected to the two ends of the protective gas channel 7.

[0137] It is understood that the conveying component 8 is mainly related to the reactive carrier material that initiates the reaction (mainly copper foil material in this specific embodiment). Therefore, the conveying component 8 is made of copper foil material, so that the pyrolysis carbon black can achieve the growth of functional groups on the surface of the pyrolysis carbon black under the action of the reactive carrier material initiated by the copper foil at the modification temperature.

[0138] The continuous feed extruder I is fixed to the device body II via a flange, and is inserted into the device body II, extending directly above the conveying assembly 8. The continuous discharge extruder III is fixedly connected to the device body II via a flange, and is installed at the bottom of the device body II, forming a 45-degree angle with the housing 6, to facilitate the continuous input and output of pyrolytic carbon black.

[0139] The main body II of the device is fixedly installed with a transmission assembly 5 and a bearing assembly 4; the two ends of the conveying assembly 8 are respectively provided with a main drive wheel 9 and a driven drive wheel 10. The transmission assembly 5 drives the bearing assembly 4 and the main drive wheel 9 of the conveying assembly to rotate, thereby driving the conveying assembly 8 and the driven drive wheel 10 of the conveying assembly to rotate at a uniform speed.

[0140] like Figure 3As shown, in order to ensure that the protective gas does not leak in the main body II of the device, a sealing component 1 needs to be installed at the mating part of the housing 6 with the main drive wheel 9 of the conveying component and the driven drive wheel 10 of the conveying component. The sealing assembly 1 consists of a transmission wheel central shaft 9-1, a sealing rotating ring 4-1, a sealing ring 4-2, a housing side wall 6-1, a lubricating oil port 6-2, a static sealing upper ring 4-3, and a static sealing lower ring 4-4. The sealing rotating ring 4-1 has a U-shaped structure and is interference-fitted to the corresponding part of the transmission wheel central shaft 9-1, with the sealing working plane of the sealing rotating ring 4-1 extending 1-2 mm beyond the working surface of the transmission wheel central shaft 9-1. Two circular rings are welded to the mating area between the housing side wall 6-1 and the sealing rotating ring 4-1 to form precision sealing rings (the static sealing upper ring 4-3 and the static sealing lower ring 4-4, respectively), where the static sealing upper ring 4-3 is 10 mm longer than the static sealing lower ring 4-4. The sealing ring 4-2 is located in the sealing working area between the sealing rotating ring 4-1 and the static sealing upper ring 4-3 and static sealing lower ring 4-4. Lubricating oil is introduced through the lubricating oil port 6-2 to lubricate the sealing working area.

[0141] The process flow of the pyrolytic carbon black structure regeneration device provided by this invention is as follows:

[0142] Pyrolytic carbon black and an external carbon source are continuously and uniformly fed into the conveying assembly 8 in the main body 2 of the device via a continuous feed extruder Ⅰ. An electric heating coil is installed on the shell 6 of the main body Ⅱ, maintaining the high temperature required for the pyrolytic carbon black modification process. Under the action of the transmission assembly 5, the bearing assembly 4 and the main drive wheel 9 of the conveying assembly rotate. The rotation of the main drive wheel 9 drives the conveying assembly 8 and the driven drive wheel 10 of the conveying assembly to rotate at a uniform speed. Since the material of the conveying assembly 8 is copper foil, the reactive carrier required in the pyrolytic carbon black structural reconstruction process, new functional group structures grow on the surface of the pyrolytic carbon black under high temperature and the action of the external carbon source. The entire process needs to be carried out in a specific reaction atmosphere, which is mainly introduced into the protective gas channel 7 through the protective gas inlet 2. The protective gas channel 7 is installed approximately 20% above the middle of the conveying assembly 8, facilitating direct action of the protective gas on the reactive region of the pyrolytic carbon black. Part of the protective gas is discharged from the protective gas outlet 3. The processed pyrolytic carbon black is continuously output to the outside of the equipment via a continuous discharge extruder Ⅲ.

[0143] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, alterations, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing structurally reconstituted pyrolytic carbon black, characterized in that, The preparation method involves solidifying the active carbon component generated from the decomposition of an external carbon source onto the surface of pyrolytic carbon black on a heated copper foil carrier under certain temperature conditions, forming new pore structures and chemical functional groups, and reshaping the structure and surface microchemical environment of the pyrolytic carbon black. The method includes the following steps: S1: When the carbon source is gaseous hydrocarbon, the gaseous hydrocarbon is continuously introduced at an inlet rate of 20 ml / min. Under the protection of argon, the gaseous hydrocarbon, pyrolytic carbon black and copper foil carrier are brought into full contact for 5-10 seconds at a heating rate of 10-15 K / min and a final temperature of 900-950℃ to obtain modified pyrolytic carbon black. When the carbon source is a high carbon content polymer, the mass ratio of the high carbon content polymer to pyrolytic carbon black is 1.5-2:

100. Under an argon protective atmosphere, at a heating rate of 5-10 K / min and a final temperature of 830-880℃, the pyrolytic carbon black is fully contacted with the decomposition products of the high carbon content polymer and the copper foil carrier for 8-12 seconds to obtain modified pyrolytic carbon black. When the carbon source is a thermosetting resin, the mass ratio of thermosetting resin to pyrolytic carbon black is 2.5-3.5:

100. Under a nitrogen protective atmosphere, at a heating rate of 2-5 K / min and a final temperature of 950-980℃, the pyrolytic carbon black is brought into full contact with the decomposition products of the thermosetting resin and the copper foil carrier for 5-8 seconds to obtain modified pyrolytic carbon black. S2: The modified pyrolytic carbon black is treated at a temperature of 450-550℃ with a plasma discharge power of 200-400W for 1-3 minutes. S3: Place the treated modified pyrolytic carbon black in an acidic solution with a concentration of 4-9 mol / L and soak for 5-15 min; S4: Drying; S5: By thoroughly mixing supercritical carbon dioxide with reconstructed pyrolytic carbon black and spraying it out through a special nozzle, the particle size of the pyrolytic carbon black is refined through the strong high-frequency pulsating shear force field formed by the rapid expansion of supercritical carbon dioxide, and finally reconstructed pyrolytic carbon black is obtained.

2. The preparation method according to claim 1, characterized in that, The gaseous hydrocarbon is selected from gaseous hydrocarbons with a carbon content of more than 90%, including methane; the high carbon content polymer includes any one or a mixture of several of polyethylene, polypropylene, and polystyrene.

3. The preparation method according to claim 1, characterized in that, In step S1, an external carbon source is solidified onto the surface of pyrolytic carbon black to form chemical functional groups. When gaseous hydrocarbons are used as the carbon source, the functional groups are mainly hydroxyl groups. When high carbon content polymers are used as the carbon source, the functional groups are mainly hydroxyl and amide groups. When thermosetting resins are used as the carbon source, the functional groups are mainly hydroxyl and aromatic groups.

4. The preparation method according to claim 1, characterized in that, Step S2 involves localized oxidation of the modified pyrolytic carbon black, specifically, the modified pyrolytic carbon black is subjected to plasma-enhanced surface carbon source structure at a certain temperature; including: Modified pyrolytic carbon black was treated at 450℃ with a plasma discharge power of 200W for 3 minutes; or, Modified pyrolytic carbon black was treated at 500℃ with a plasma discharge power of 300W for 2 minutes; or, Modified pyrolytic carbon black was treated at 550℃ with a plasma discharge power of 400W for 1 minute.

5. The preparation method according to claim 1, characterized in that, Step S3 involves etching the modified pyrolytic carbon black, wherein the acidic solution is one or both of sulfuric acid and hydrofluoric acid. Among them, under sulfuric acid conditions: its concentration is 5~9 mol / L, and the soaking time is 10~15 min; Under hydrofluoric acid conditions: the concentration is 4~7 mol / L, and the soaking time is 5~10 min.

6. The reconstituted pyrolytic carbon black prepared by the preparation method according to any one of claims 1-5.

7. The structurally reconstituted pyrolytic carbon black according to claim 6, characterized in that, The reconstituted pyrolytic carbon black is mixed with rubber to prepare a reconstituted pyrolytic carbon black rubber composite material.

8. An apparatus for implementing the preparation method according to any one of claims 1-5, characterized in that, The device includes a continuously feeding extruder, a device body, and a continuously discharging extruder connected in sequence. A transmission assembly and a bearing assembly are fixedly mounted on the device body. The device body includes a housing with an electric heating coil mounted on it. Inside the housing are a conveying assembly and a protective gas channel. The conveying assembly is made of copper foil, and the protective gas channel is located slightly above the center of the conveying assembly. The continuously feeding extruder is inserted into the device body and extends directly above the conveying assembly. The conveying assembly has a main drive wheel and a driven drive wheel at each end. The transmission assembly drives the bearing assembly and the main drive wheel to rotate, thereby causing the conveying assembly and the driven drive wheel to rotate at a uniform speed. The device also includes a sealing assembly. The continuous discharge extruder is fixedly connected to the main body of the device and forms a 45-degree angle with the shell; The housing is also provided with a protective gas inlet and a protective gas outlet, which are respectively connected to both ends of the protective gas channel; The protective gas channel is installed at a position 20% above the middle of the conveying assembly; A sealing assembly is provided at the position where the housing mates with the main drive wheel and the driven drive wheel of the conveying assembly. The sealing assembly includes a housing sidewall, a drive wheel central shaft, and a sealing ring that is interference-fitted with the drive wheel central shaft. The sealing ring has a U-shaped structure, and its sealing working plane extends 1-2 mm beyond the working surface of the drive wheel central shaft. A static sealing upper ring and a static sealing lower ring are provided at the mating position between the housing sidewall and the sealing ring. Both the static sealing upper ring and the static sealing lower ring are circular rings, with the static sealing upper ring being 10 mm longer than the static sealing lower ring. A sealing ring is provided between the sealing ring and the static sealing upper ring and the static sealing lower ring. The sealing assembly also includes a lubricating oil port.

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