High thermal conductivity carbon black, preparation method therefor, and tire bladder

Abstract

The present disclosure relates to the technical field of carbon black materials, and in particular relates to a high thermal conductivity carbon black, a preparation method therefor, and a tire bladder. The high thermal conductivity carbon black has a thermal conductivity of 0.1462-0.2097 W / m·K; the carbon black has an average primary particle size of 25-45 nm; and the carbon black primary particles comprise carbon spheres and epitaxial carbon layers located on surfaces of the carbon spheres. The thermal conductivity of the carbon black of the present disclosure is an improvement of up to 79% relative to commonly used carbon blacks on the market; the thermal conductivity performance of carbon black is significantly improved, which facilitates improvement in the thermal conductivity of tire bladders while also retaining the service life thereof, and costs are also reduced.

Description

Carbon black with high thermal conductivity, preparation method thereof, and tire bladder

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority and benefits to the Chinese patent application with patent application number 202311792327.2 filed with the State Intellectual Property Office of China on December 25, 2023, and entitled “Carbon black with high thermal conductivity, preparation method thereof, and tire capsule”, and incorporates the entire text of the patent application into this disclosure by reference. Technical Field

[0003] The present disclosure relates to the technical field of carbon black materials, and in particular to carbon black with high thermal conductivity, a preparation method thereof, and a tire bladder. Background Art

[0004] The tire bladder is primarily a tool for tire vulcanization and a crucial mold in the tire production process, serving as the inner mold of the tire mold. During the vulcanization process, the tire bladder is filled with compressed air, nitrogen, or superheated water, causing it to expand and support the tire rubber blank to form an internal pressure-vulcanized tire. The exterior of the green tire is in direct contact with the steel mold. Because the steel mold has better thermal conductivity than the vulcanization bladder, improving the thermal conductivity of the vulcanization bladder can shorten the green tire vulcanization time, thereby saving energy, improving production efficiency, and reducing production costs.

[0005] Currently, common tire bladders use conventional carbon black as a reinforcing filler, resulting in low thermal conductivity, long curing times, and a short service life, making them difficult to meet market demand. Existing techniques have been proposed to improve the thermal conductivity and efficiency of tire bladders by blending materials with higher thermal conductivity (such as graphene, carbon nanotubes, and fiber fillers), but this introduces dispersibility and cost issues. Therefore, finding a balance between improving the thermal conductivity of curing bladders and maintaining a good service life and low cost remains a technical challenge in this field.

[0006] In view of this, the present disclosure is proposed.

[0007] Summary of the Invention

[0008] The purpose of the present disclosure is to provide carbon black with high thermal conductivity, a preparation method thereof, and a tire bladder. The carbon black disclosed in the present disclosure has excellent thermal conductivity, can significantly improve the thermal conductivity of the tire bladder while maintaining its service life and saving costs.

[0009] In order to achieve the above-mentioned purpose of the present disclosure, the present disclosure provides, on one hand, carbon black with high thermal conductivity, wherein the thermal conductivity of the carbon black is 0.1462 to 0.2097 W / m·K;

[0010] The average particle size of the primary particles of the carbon black is 25 to 45 nm; the primary particles of the carbon black include carbon spheres and epitaxial carbon layers located on the surfaces of the carbon spheres.

[0011] In a specific embodiment of the present disclosure, the carbon black satisfies the following characteristics:

[0012] (a) BET specific surface area is 70 to 160 m 2 / g;

[0013] (b) DBP oil absorption value is 240~350cm 3 / 100g;

[0014] (c) In the 2D Raman spectrum with an excitation wavelength of 532 nm, the -1 The full width at half maximum (FWHM) of the 2D Raman scattering peak in the range of 118 to 128 cm -1 The ratio of the peak intensity of the 2D Raman scattering peak to the peak intensity of the G Raman scattering peak is 0.32-0.61, and the plane size of the Raman crystallite is

[0015] In a specific embodiment of the present disclosure, the crystallinity of the carbon black is 45% to 50%, such as 47% to 50%.

[0016] In a specific embodiment of the present disclosure, the thermal conductivity of the carbon black is 0.1541 to 0.2097 W / m·K.

[0017] In a specific embodiment of the present disclosure, the carbon black is acetylene black.

[0018] In a specific embodiment of the present disclosure, the epitaxial carbon layer is in-situ grown on the surface of the carbon sphere.

[0019] Another aspect of the present disclosure provides a method for preparing any one of the above-mentioned carbon blacks, comprising the following steps:

[0020] Acetylene and methane undergo thermal cracking reaction in an environment containing carbon dioxide and isolated from air to form carbon black.

[0021] In a specific embodiment of the present disclosure, the flow ratio of the acetylene, the methane, and the carbon dioxide is 20:5:(2-7).

[0022] In a specific embodiment of the present disclosure, the acetylene and methane gas flows are in opposite directions, and the carbon dioxide gas flow is arranged at an angle to the acetylene and methane gas flows. Furthermore, the angle is 45° to 60°.

[0023] In another aspect, the present disclosure provides a tire bladder, comprising a rubber matrix and a filler; the filler comprises any one of the carbon blacks described above.

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

[0025] (1) The carbon black disclosed herein can improve the thermal conductivity by up to 79% compared to commercially available carbon black, significantly improving the thermal conductivity of carbon black, helping to improve the thermal conductivity of tire bladders while maintaining their service life and saving costs;

[0026] (2) The carbon black preparation method disclosed in the present invention has a simple process and is easy to produce on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] FIG1 is a schematic structural diagram of an apparatus for preparing carbon black with high thermal conductivity provided in an embodiment of the present disclosure;

[0029] FIG2 is a schematic top view of a nozzle and a furnace head provided in an embodiment of the present disclosure;

[0030] FIG3 is a transmission electron microscope image of the carbon black prepared in Example 1 of the present disclosure;

[0031] FIG4 is a partial enlarged view of the transmission electron microscope image of FIG3;

[0032] FIG5 is another partial enlarged view of the transmission electron microscope image of FIG3;

[0033] FIG6 is a Raman spectrum of the carbon black prepared in Example 1 of the present disclosure;

[0034] FIG7 is a Raman spectrum of the carbon black prepared in Example 2 of the present disclosure;

[0035] FIG8 is a Raman spectrum of the carbon black prepared in Example 3 of the present disclosure.

[0036] FIG9 is a Raman spectrum of the carbon black of Comparative Example 1 of the present disclosure;

[0037] FIG10 is a Raman spectrum of the carbon black prepared in Comparative Example 2 of the present disclosure.

[0038] Reference numerals:

[0039] 10-cracking furnace body; 11-reaction chamber; 12-furnace head;

[0040] 13-nozzle; 14-gas inlet pipe; 15-discharge port;

[0041] 131 - first nozzle; 132 - second nozzle. DETAILED DESCRIPTION

[0042] The technical solutions of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but those skilled in the art will understand that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments, and are only used to illustrate the present disclosure, and should not be considered as limiting the scope of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present disclosure. If specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0043] Carbon black can be used as a common reinforcing filler in the preparation of tire bladders. However, with the rapid popularization of radial tires, high-performance tire manufacturing has also put forward higher requirements on the standards of tire bladders. In order to balance improving the thermal conductivity of the vulcanization bladder with maintaining a good service life and low cost, it is necessary to further improve the thermal conductivity of carbon black while maintaining other properties.

[0044] Based on this, the present disclosure provides, on one hand, carbon black with high thermal conductivity, wherein the thermal conductivity of the carbon black is 0.1462 to 0.2097 W / m·K;

[0045] The average particle size of the primary particles of carbon black is 25 to 45 nm; the primary particles of carbon black include carbon spheres and epitaxial carbon layers located on the surfaces of the carbon spheres.

[0046] Thermal conductivity was measured using a thermal constant analyzer (Hot Disk). For example, in various embodiments, the thermal conductivity of carbon black can be 0.1462 W / m·K, 0.15 W / m·K, 0.16 W / m·K, 0.17 W / m·K, 0.18 W / m·K, 0.19 W / m·K, 0.20 W / m·K, 0.2097 W / m·K, or any combination thereof.

[0047] After research, the inventors found that when the BET specific surface area, DBP absorption value and 2D Raman spectrum of carbon black simultaneously meet certain requirements, the corresponding thermal conductivity of carbon black can be significantly improved, thereby meeting the high requirements of high-performance tire manufacturing for tire bladders.

[0048] Among them, theoretically speaking, the larger the BET, the smaller the primary particles of the material, and the more primary particles of the same mass, the more they can be stacked to build a richer thermal conductivity network, and the better the thermal conductivity performance. However, the smaller the primary particles, the greater the intermolecular forces of conventional carbon black will become, which will introduce dispersion problems when used in downstream blending, resulting in problems such as local heating in downstream products. Based on this, the inventors further discovered that when an epitaxial carbon layer structure is introduced on the surface of carbon black and the carbon black surface is etched to a certain extent, on the one hand, the dispersion is significantly improved, and on the other hand, the surface contact between carbon black particles and between carbon black and other materials can be increased, thereby expanding the thermal conductivity network and further improving thermal conductivity.

[0049] DBP oil absorption and 2D Raman spectroscopy are microscopic parameters of carbon black. DBP oil absorption characterizes the void volume within carbon black aggregates. Introducing new structures and etching the carbon black surface both increase the void volume within the carbon black aggregates to a certain extent. A higher DBP oil absorption indicates a more developed branched structure, leading to a more developed thermal network and improved thermal conductivity. 2D Raman spectroscopy can reveal the specific number of layers and stacking pattern of the epitaxial carbon layer structure introduced into carbon black.

[0050] Therefore, it is necessary to precisely and quantitatively control the range of each parameter to make carbon black have a better thermal conductive network and high thermal conductivity.

[0051] In a specific embodiment of the present disclosure, carbon black satisfies the following characteristics:

[0052] (a) BET specific surface area is 70 to 160 m 2 / g;

[0053] (b) DBP oil absorption value is 240~350cm 3 / 100g;

[0054] (c) In the 2D Raman spectrum with an excitation wavelength of 532 nm, the -1 The full width at half maximum (FWHM) of the 2D Raman scattering peak in the range of 118 to 128 cm -1 The ratio of the peak intensity of the 2D Raman scattering peak to the peak intensity of the G Raman scattering peak is 0.32-0.61, and the plane size of the Raman crystallite is

[0055] The BET specific surface area is tested according to the method of GB / T19587-2004. For example, in different embodiments, the BET specific surface area of ​​carbon black can be 70 m 2 / g、80m 2 / g、90m 2 / g、100m 2 / g、110m2 / g, 120m 2 / g, 130m 2 / g, 140m 2 / g, 150m 2 / g, 160m 2 / g or a range consisting of any two of them.

[0056] The DBP oil absorption value is determined using the standard method of "GB / T 3780.2-2017 Carbon Black Part 2: Determination of Oil Absorption Value". For example, in different embodiments, the DBP oil absorption value of carbon black can be 240 cm 3 / 100g、250cm 3 / 100g、256cm 3 / 100g、300cm 3 / 100g、350cm 3 / 100g or a range consisting of any two thereof.

[0057] The specific 2D Raman spectroscopy test method and test parameters are as follows:

[0058] Using a laser Raman spectrometer, several carbon black particles were placed on a glass slide and scraped several times with a spatula to flatten the sample. The measurements were performed under the following conditions: YAG laser (excitation wavelength): 532 nm, number of lines: 600 gr / mm, filter: D0.6, objective magnification: 100x, exposure time: 150 seconds, and accumulation times: 2. The Raman crystallite planar size (La) was measured using Raman spectroscopy. Regression analysis yielded the following empirical relationship: La = 43.5 × (area of ​​the G band / area of ​​the D band), where La is expressed in angstroms. La can be used to characterize the crystal domains of carbon black and provide an indication of the degree of graphitization; higher La values ​​indicate a higher degree of graphitization.

[0059] For example, in different embodiments, in the 2D Raman spectrum of carbon black with an excitation wavelength of 532 nm, the peak position range of the 2D Raman scattering peak can be selected from but not limited to 2670 cm -1 、2675cm -1 、2680cm -1 、2685cm -1 、2690cm -1 or a range consisting of any two thereof; the full width at half maximum Δ2D corresponding to the 2D Raman scattering peak can be selected from but not limited to 118 cm -1 , 120cm -1 , 122cm -1 , 124cm -1 , 125cm -1 、126cm -1 、128cm-1 Or the range of any two thereof; the peak intensity of the 2D Raman scattering peak (I 2D ) and the peak intensity of the G Raman scattering peak (I G ) ratio I 2D / I G The Raman crystallite size of carbon black can be selected from but not limited to 0.32, 0.43, 0.45, 0.50, 0.51, 0.53, 0.55, 0.57, 0.59, 0.61 or any two thereof; the Raman crystallite size of carbon black can be selected from but not limited to Or a range consisting of any two of them.

[0060] In a specific embodiment of the present disclosure, the crystallinity of the carbon black is 45% to 50%, such as 47% to 50%. The crystallinity can be used to characterize the degree of graphitization of the carbon black, which is measured in Raman spectroscopy as the ratio of the intensity of the G band to the sum of the intensities of the G band and the D band (I G / I G+D The carbon black disclosed herein has a high degree of graphitization. When used as a filler in rubber, the carbon black can form a thermally conductive network in the rubber, thereby improving the thermal conductivity of the rubber due to the high degree of graphitization of the carbon black.

[0061] For example, in different embodiments, the crystallinity of carbon black may be 45%, 47%, 48%, 50%, or a range consisting of any two thereof.

[0062] In a specific embodiment of the present disclosure, the thermal conductivity of carbon black is 0.1541 to 0.2097 W / m·K.

[0063] In a specific embodiment of the present disclosure, the carbon black is acetylene black.

[0064] In a specific embodiment of the present disclosure, an epitaxial carbon layer is grown in situ on the surface of the carbon spheres.

[0065] Another aspect of the present disclosure provides a method for preparing any of the above-mentioned carbon blacks, comprising the following steps:

[0066] Acetylene and methane undergo thermal cracking reaction in an environment containing carbon dioxide and isolated from air to form carbon black.

[0067] In the disclosed carbon black preparation method, acetylene is thermally cracked to generate nuclei for acetylene black, which then grow. Simultaneously, the heat generated by the thermal cracking of acetylene causes methane to decompose and grow, generating a significant amount of hydrogen atoms. This slows down and prevents the curling and closing of carbon clusters on the acetylene black surface, forming a spherical surface and, consequently, forming an epitaxial carbon layer on the acetylene black carbon spheres. Furthermore, the carbon dioxide in the reaction system reacts with the high-temperature carbon generated by the cracking to generate a significant amount of active oxygen atoms, which etch the acetylene black surface, hindering or severing the formation of a perfect spherical carbon layer on the surface of the acetylene black carbon spheres and promoting the formation of an epitaxial carbon layer on the acetylene black carbon spheres.

[0068] In a specific embodiment of the present disclosure, the flow ratio of acetylene, methane, and carbon dioxide is 20:5:(2-7).

[0069] For example, in various embodiments, the flow ratio of acetylene, methane, and carbon dioxide can be 20:5:2, 20:5:3, 20:5:4, 20:5:6, 20:5:7, or any combination thereof. The corresponding carbon black structure can be obtained by ensuring that the flow ratio of acetylene, methane, and carbon dioxide in the reaction environment is within the aforementioned range.

[0070] In a specific embodiment of the present disclosure, the acetylene and methane gas flows are arranged in opposite directions to facilitate uniform mixing of the acetylene and methane. The carbon dioxide gas flow is arranged at an angle to the acetylene and methane gas flows. The angle is preferably 45° to 60°.

[0071] By regulating the flow directions of carbon dioxide, acetylene, and methane to meet the above conditions, the acetylene black produced by the cracking of acetylene and methane can be rapidly passed through the reaction zone, avoiding the presence of a reflux zone that could terminate the reaction, further promoting the formation of an epitaxial carbon layer on the acetylene black carbon spheres. For example, in various embodiments, the angle can be 45°, 48°, 50°, 52°, 55°, 58°, 60°, or a range consisting of any two thereof.

[0072] In another aspect, the present disclosure provides an apparatus for implementing any of the aforementioned carbon black production methods, as shown in FIG1 , comprising a cracking furnace body 10 having a reaction chamber 11 formed therein for performing a thermal cracking reaction. The structure of the reaction chamber 11 can be adapted to that of the cracking furnace body 10 .

[0073] The cracking furnace body 10 is provided with two nozzles 13 in communication with the reaction chamber 11 for introducing gas into the reaction chamber 11. The two nozzles 13 can extend into the reaction chamber 11 to introduce gas into the reaction chamber 11 to ensure the smooth progress of the thermal cracking reaction.

[0074] The cracking furnace body 10 is formed with a furnace head 12 corresponding to the two nozzles 13 ; the furnace head 12 is provided with at least one gas introduction pipe 14 communicating with the reaction chamber 11 for introducing carbon dioxide into the reaction chamber 11 .

[0075] As shown in Figure 2, the two nozzles 13 include a first nozzle 131 and a second nozzle 132. The first nozzle 131 is used to introduce air or methane into the reaction chamber 11, while the second nozzle 132 is used to introduce acetylene into the reaction chamber 11. The first nozzle 131 and the second nozzle 132 are positioned on opposite sides of the furnace head 12, near one end of the furnace head 12, with the central axes of the first and second nozzles 131, 132 perpendicular to the central axis of the furnace head 12. The jets from the first and second nozzles 131, 132 are directed in opposite directions.

[0076] In actual operation, air can be introduced through the first nozzle 131 and acetylene gas can be introduced through the second nozzle 132 to cause combustion and heat up to a certain temperature (such as 850°C) to preheat the cracking furnace; then, after cutting off the air supply for a period of time, methane gas is supplied from the first nozzle 131 and carbon dioxide is introduced through the gas inlet pipe 14 to cause a thermal cracking reaction, and the carbon black is collected after cooling.

[0077] In a specific embodiment of the present disclosure, two gas introduction pipes 14 are included, and the two gas introduction pipes 14 are arranged opposite to each other on both sides of the furnace head 12 .

[0078] In actual operation, the cracking furnace body 10 may be provided with conventional heating components and temperature control components.

[0079] In the embodiment of the present disclosure, the central axis of the gas inlet pipe 14 is arranged at an angle to the central axis of the furnace head 12. Further, the angle is 30° to 45°. In subsequent embodiments, unless otherwise specified, the angle is 40°, but the present invention is not limited thereto.

[0080] By adjusting the angle between the central axis of the gas inlet pipe 14 and the central axis of the furnace head 12, the acetylene black generated by the cracking of acetylene and methane can pass through the reaction zone quickly, avoiding the long-term existence of the reflux zone and terminating the reaction, further promoting the formation of an epitaxial carbon layer on the acetylene black carbon balls.

[0081] In a specific embodiment of the present disclosure, the cracking furnace body 10 further includes a discharge port 15 , which is disposed at one end of the reaction chamber 11 away from the furnace head 12 . When the reaction is completed, the carbon black leaves the reaction chamber 11 through the discharge port 15 .

[0082] In another aspect, the present disclosure provides a tire bladder, comprising a rubber matrix and a filler; the filler comprises any one of the above-mentioned carbon blacks.

[0083] Among them, carbon black is used as a filler in tire bladders, which can completely replace or partially replace the original filler in the tire bladder. Carbon black can be used as the only filler or used together with other fillers. The other fillers include but are not limited to any one or more of commercially available acetylene black, carbon black N220, carbon black N330 and carbon black N660.

[0084] In a specific embodiment of the present disclosure, the amount of carbon black disclosed herein is 25% to 31% of the mass of the rubber matrix.

[0085] In a specific embodiment of the present disclosure, the rubber matrix includes, but is not limited to, butyl rubber.

[0086] The tire bladder of the present disclosure may also contain other conventional additives, including but not limited to softeners, vulcanizers, active agents, and processing aids. The softeners include but are not limited to castor oil, the vulcanizers include but are not limited to vulcanized resins, the active agents include but are not limited to chloroprene rubber and zinc oxide, and the processing aids include but are not limited to stearic acid.

[0087] In addition, the tire bladder may also include additives such as active substances and dispersants.

[0088] Examples 1 to 3

[0089] Examples 1 to 3 provide methods for preparing carbon black with high thermal conductivity, which are prepared using the apparatus shown in FIG1 and include the following steps:

[0090] (1) Acetylene gas is heated at 10 Nm 3 / h flow rate and air at 60Nm 3 / h flow rate into the cracking furnace 10, so that it burns and heats up to 850°C to preheat the cracking furnace body 10; wherein, air is supplied through the first nozzle 131 and acetylene is supplied through the second nozzle 132.

[0091] (2) Continue to supply acetylene through the second nozzle 132, and cut off the air supply for a period of time to ensure that the cracking furnace is isolated from the air. Then, supply methane gas from the first nozzle 131 and supply carbon dioxide through the gas inlet pipe 14. After the thermal cracking reaction is carried out in the reaction chamber 11, the carbon black produced is collected after cooling.

[0092] In the preparation methods of Examples 1 to 3, in step (2), the flow rates of acetylene gas, methane gas and carbon dioxide are shown in Table 1.

[0093] Table 1 Flow information

[0094] Example 4

[0095] This embodiment provides a tire bladder, wherein, by weight, the amounts of the raw materials are: 100 parts of butyl rubber, 8 parts of castor oil, 30 parts of carbon black, 9 parts of vulcanized resin, 4 parts of chloroprene rubber, 6 parts of zinc oxide, and 2 parts of stearic acid.

[0096] This embodiment also provides a method for preparing a tire capsule, which specifically includes the following steps:

[0097] (1) Ingredients: Weigh each raw material separately. The amount of each raw material used is: 100 parts of butyl rubber, 8 parts of castor oil, 30 parts of carbon black, 9 parts of vulcanized resin, 4 parts of chloroprene rubber, 6 parts of zinc oxide and 2 parts of stearic acid.

[0098] (2) Mixing: butyl rubber, chloroprene rubber, stearic acid, carbon black, and castor oil are sequentially put into a mixer and mixed for 4 minutes;

[0099] (3) After mixing, the first stage coke is discharged at a temperature of 150°C, and then the coke is filtered and left to stand for 24 hours;

[0100] (4) Adding vulcanized resin and zinc oxide to the last stage of coke for two-stage mixing, the mixing time is 7 minutes;

[0101] (5) The mixed second-stage coke is discharged at a temperature of 120°C and left for 24 hours;

[0102] (6) Extruding the rubber strips: Extruding the second-stage rubber strips with a cold feed extruder, and controlling the temperature of the extruded rubber strips at 130°C;

[0103] (7) Bladder molding: The extruded rubber strip is prepared into a tire bladder using an injection vulcanizer. The vulcanization temperature is 200°C and the vulcanization mold pressure is 20Pa.

[0104] The carbon black in each tire bladder is the carbon black obtained in Examples 1 to 3, and the corresponding tire bladders are numbered as Example 4-1, Example 4-2, and Example 4-3, respectively.

[0105] Comparative Example 1

[0106] Comparative Example 1 provides a commercially available SP carbon black.

[0107] Comparative Example 1 also provides a tire bladder, which is prepared according to the method of Example 4, except that the carbon black is replaced with an equal weight of commercially available SP carbon black.

[0108] Comparative Example 2

[0109] Comparative Example 2 provides a carbon black, and the preparation method is the same as that of Example 1, except that: in step (2), no carbon dioxide is supplied.

[0110] Experimental Example 1

[0111] Figures 3 to 5 are transmission electron microscope images of the carbon black obtained in Example 1 of the present disclosure. It can be seen from the figures that the primary particles of the carbon black disclosed in the present disclosure are roughly spherical, and the primary particles include carbon spheres and epitaxial carbon layers located on the carbon spheres. At the same time, the lattice fringes of the epitaxial carbon layer are clear and have the characteristics of graphene or graphite carbon layers, and have good thermal conductivity. Since the carbon spheres of the primary particles have epitaxial carbon layers on their surfaces, point-to-surface contact can be formed between the primary particles of the carbon black, thereby improving thermal conductivity, which has obvious advantages over the point-to-point contact of traditional carbon black.

[0112] In addition, the average particle size of the primary particles of the carbon black of different examples and comparative examples (the average particle size of 100 primary particles observed by transmission electron microscopy) is shown in the following table. As can be seen from Table 2, the average particle size of the primary particles of the carbon black disclosed herein is 25 to 45 nm.

[0113] Table 2 Carbon black morphology information of different embodiments and comparative examples

[0114] Experimental Example 2

[0115] Raman spectroscopy tests were performed on the carbon black of different embodiments and comparative examples. The specific testing method was as follows: using a laser Raman spectroscopy device, several particles of the carbon black sample to be tested were placed on a glass slide, and scraped with a spatula several times to make it flat. The test was performed under the following test conditions: YAG laser (excitation wavelength): 532 nm, number of lines: 600 gr / mm, filter: D0.6, objective lens magnification: 100x, exposure time: 150 seconds, and accumulation times: 2 times.

[0116] Figures 6 to 8 are Raman spectra of the carbon black prepared in Examples 1 to 3 of the present disclosure, respectively. The carbon black prepared in Examples 1 to 3 has a Raman spectrum of 2670 to 2690 cm -1 The full width at half maximum (FWHM) of the 2D Raman scattering peaks appearing in the range are 125, 118, and 128 cm -1 Among them, the 2D Raman scattering peak is a symmetrical sharp single peak, and the peak position of the 2D Raman scattering peak is lower than that of general bulk graphite (about 2710 cm -1 ) shifts to the left, which is the characteristic peak of the carbon layer with graphene structure different from that of bulk graphite, which also proves the existence of epitaxial carbon layer in the carbon black disclosed in the present invention, which is consistent with the TEM result.

[0117] In addition, the 2D Raman scattering peak is highly correlated with the graphene layer structure and stacking mode. Generally, the fewer the graphene layers, the sharper and more symmetrical the 2D Raman scattering peak. The 2D Raman scattering peak of the carbon black prepared in the present disclosure is symmetrical, and the ratio of the peak intensity of the 2D Raman scattering peak to the peak intensity of the G Raman scattering peak (I 2D / IG ) are 0.32, 0.51, and 0.61 respectively. 2D / I G As the ratio decreases, the number of graphene layers increases, but the Raman scattering of the graphite layer on the surface of the carbon black carbon ball is removed, which affects the contribution of the Raman spectrum G peak of the carbon black. 2D / I G is 0.32~0.61, indicating that the carbon black has a small number of epitaxial carbon layers and has a graphene-like structure, which is consistent with the TEM results. 2D / I G When the carbon black carbon layer is 0.32 to 0.61, the carbon black epitaxial carbon layer can exhibit the unique flexibility of the graphene sheet, and can improve the surface contact between the epitaxial carbon layers and between the epitaxial carbon layer and the carbon black carbon balls, so that the carbon black can have excellent thermal conductivity.

[0118] The La of the carbon black prepared in Examples 1 to 3 are This indicates that the carbon black prepared in the present invention has a high degree of graphitization.

[0119] At the same time, the degree of graphitization of carbon black is further characterized by crystallinity. It is measured by Raman spectroscopy that the crystallinity of the carbon black prepared in specific Examples 1 to 3 is 47%, 50%, and 45%, respectively, further illustrating that the carbon black prepared in the present disclosure can obtain a high degree of graphitization. Therefore, when it is used as a filler for rubber, a thermal conductive network can be formed in the rubber, and its high degree of graphitization can improve the thermal conductivity of the rubber.

[0120] FIG9 and FIG10 are Raman spectra of the carbon black of Comparative Examples 1 and 2 of the present disclosure, respectively. As can be seen from the figures, the Raman spectra of Comparative Examples 1 and 2 have no 2D Raman scattering peaks.

[0121] The characteristic information of carbon black of different embodiments and comparative examples of the present disclosure obtained based on Raman spectroscopy is shown in Table 3.

[0122] Table 3 Characteristic information of different embodiments and comparative examples

[0123] Experimental Example 3

[0124] The BET specific surface area of ​​the carbon black of different embodiments and comparative examples was tested in accordance with GB / T19587-2004; the thermal conductivity of the carbon black of different embodiments and comparative examples was tested using a Hot Disk thermal constant analyzer; and the DBP oil absorption value of the carbon black of different embodiments and comparative examples was determined using the standard method of "GB / T 3780.2-2017 Carbon Black Part 2: Determination of Oil Absorption". The specific test results are shown in Table 4.

[0125] Table 4 Test results of BET specific surface area, thermal conductivity and DBP oil absorption value of different embodiments and comparative examples

[0126] As shown in Table 4, the carbon black disclosed herein has a high BET specific surface area, indicating a well-developed porous structure. This increases the number of contact points between the carbon black and the rubber substrate, fully utilizing the carbon black's thermal conductivity. The carbon black disclosed herein also exhibits a high thermal conductivity, up to 79% higher than that of commonly used commercially available carbon black. The high DBP oil absorption, which measures the void volume within the carbon black aggregates, indicates that the carbon black disclosed herein has a well-developed chain branch structure, forming an efficient thermally conductive network.

[0127] The thermal conductivity of the tire bladders in Example 4 and Comparative Examples 1-2 was further tested using a Hot Disk thermal constant analyzer. The specific results are shown in Table 5.

[0128] Table 5 Thermal conductivity of different tire bladders

[0129] As can be seen from the above table, the thermal conductivity of the tire bladder disclosed herein is significantly improved compared to that of ordinary tire bladders, further proving that the carbon black disclosed herein has excellent thermal conductivity and can significantly improve the thermal conductivity of rubber.

[0130] In addition, compared with ordinary tire capsules, the tire capsule disclosed herein only replaces traditional carbon black, which greatly saves costs compared to adding high-priced high-thermal conductive materials such as graphene and carbon nanotubes, while improving the performance and service life of the tire capsule.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure. Industrial Applicability

[0132] The carbon black disclosed in the present invention has excellent thermal conductivity, and its thermal conductivity coefficient can be increased by up to 79% compared with the commonly used carbon black on the market. It helps to improve the thermal conductivity of tire bladders while maintaining their service life, saves costs, and has good industrial application prospects.

Claims

1. Carbon black with high thermal conductivity, characterized in that, The thermal conductivity of the carbon black is 0.1462 to 0.2097 W / m·K; The average particle size of the primary particles of the carbon black is 25 to 45 nm; the primary particles of the carbon black include carbon spheres and epitaxial carbon layers located on the surfaces of the carbon spheres.

2. The carbon black with high thermal conductivity according to claim 1, characterized in that, The carbon black satisfies the following characteristics: (a) BET specific surface area is 70 to 160 m 2 / g; (b) The DBP oil absorption value is 240 to 350 cm 3 / 100 g; (c) In the 2D Raman spectrum with an excitation wavelength of 532 nm, the full width at half maximum Δ2D of the 2D Raman scattering peak in the range of 2670 - 2690 cm -1 is 118 - 128 cm -1 , the ratio of the peak intensity of the 2D Raman scattering peak to the peak intensity of the G Raman scattering peak is 0.32 - 0.61, and the Raman microcrystalline plane size is 3. The carbon black with high thermal conductivity according to claim 1 or 2, characterized in that, The crystallinity of the carbon black is 45% to 50%; Preferably, the crystallinity of the carbon black is 47% to 50%.

4. The carbon black with high thermal conductivity according to any one of claims 1 to 3, characterized in that, The thermal conductivity of the carbon black is 0.1541 to 0.2097 W / m·K.

5. The carbon black with high thermal conductivity according to any one of claims 1 to 4, characterized in that, The carbon black is acetylene black.

6. The carbon black with high thermal conductivity according to any one of claims 1 to 5, characterized in that, The epitaxial carbon layer grows in-situ on the surface of the carbon sphere.

7. The preparation method of the carbon black with high thermal conductivity according to any one of claims 1 to 6, characterized in that, It includes the following steps: Acetylene and methane are subjected to a thermal cracking reaction in an environment containing carbon dioxide and isolated from air to form carbon black.

8. The preparation method according to claim 7, wherein The flow rate ratio of the acetylene, the methane, and the carbon dioxide is 20﹕5﹕(2 to 7).

9. The preparation method according to claim 7 or 8, characterized in that, The gas flow directions of the acetylene and the methane are opposite; the gas flow direction of the carbon dioxide is arranged at an angle to the gas flow directions of the acetylene and the methane; Preferably, the angle is 45° to 60°.

10. A tire bladder, characterized in that, It includes a rubber matrix and a filler; the filler includes the carbon black according to any one of claims 1 to 6 or the carbon black prepared by the preparation method according to any one of claims 7 to 9.

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