A kind of high thermal conductivity rubber and its preparation method and application

Abstract

The invention discloses a high thermal conductive rubber and its preparation method and application, which relates to the technical field of rubber material preparation. The high thermal conductive rubber comprises 50-70 parts of methyl vinyl silicone rubber, 20-30 parts of hexagonal carbon nitride, Ti3AlC 2 5-10 parts, 10-15 parts of aluminum oxide, 2-4 parts of molybdenum disulfide, 5-10 parts of graphite microplatelets, 5-10 parts of modified carbon black, 0.5-1 parts of silane coupling agent, 3-5 parts of vulcanizing agent, 5-10 parts of flame retardant, 1-3 parts of dicyclopentadiene, 2-5 parts of lignin, and 0.5-1 parts of anti-aging agent. The high thermal conductivity rubber has good thermal conductivity, and the rubber material has high dispersibility and overall performance.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber material preparation, and in particular to a high thermal conductivity rubber and a preparation method and application thereof. Background Art

[0002] The rapid development of industries such as electronics and automobiles has led to higher demands on the thermal conductivity of rubber materials. In the tire industry, traditional rubber materials have poor thermal conductivity. Heat generated by friction during driving is difficult to dissipate promptly, leading to elevated tire temperatures. This, in turn, affects tire wear resistance, aging resistance, and safety, shortening tire service life. Currently, while the thermal conductivity of rubber can be improved to a certain extent by adding thermally conductive fillers, conventional alumina (Al2O3) and silica (SiO2) fillers, due to their numerous crystal defects, have a thermal conductivity coefficient of only 20-30 W / (m·K). Furthermore, a filler content of >50% is required to achieve a value above 1 W / (m·K), making the rubber material susceptible to brittle cracking. Chinese patent CN119751993A discloses a composite rubber material for track coating and its preparation method. The use of carbon nanotubes improves the thermal conductivity of the rubber. However, the carbon nanotubes tend to clump together during mixing, resulting in poor dispersion of the rubber material and affecting its overall performance. Summary of the Invention

[0003] The first technical problem to be solved by the present invention is: to address the deficiencies in the prior art and provide a high thermal conductivity rubber with good thermal conductivity, high dispersibility and overall performance of the rubber material.

[0004] In order to solve the above-mentioned first technical problem, the technical solution of the present invention is:

[0005] A high thermal conductive rubber comprising the following raw materials in parts by weight: 50-70 parts of methyl vinyl silicone rubber, 20-30 parts of hexagonal carbon nitride, 25-10 parts of Ti3AlC, 10-15 parts of aluminum oxide, 2-4 parts of molybdenum disulfide, 5-10 parts of graphite microplatelets, 5-10 parts of modified carbon black, 0.5-1 part of a silane coupling agent, 3-5 parts of a vulcanizing agent, 5-10 parts of a flame retardant, 1-3 parts of dicyclopentadiene, 2-5 parts of lignin, and 0.5-1 part of an anti-aging agent;

[0006] Wherein, the preparation method of the modified carbon black is:

[0007] Place carbon black, zinc nitrate, and 2-methylimidazole in a three-dimensional mixer at a mass ratio of 1:1.5:3.3, and premix at a speed of 60-80 rpm for 30-50 minutes to obtain a mixed powder;

[0008] The large zirconia grinding balls, mixed powder and small zirconia grinding balls are loaded into a ball mill in order from bottom to top, and the ball milling is carried out at 250 rpm for 0.5-1 h, then the speed is increased to 350 rpm for 0.5-1 h, and finally the speed is reduced to 300 rpm for 1.5-2 h. The particle size of the large zirconia grinding balls is 5 mm, the particle size of the small zirconia grinding balls is 3 mm, the volume ratio of the large zirconia grinding balls to the small zirconia grinding balls is 3:2, and the ball-to-material ratio is 10:1.

[0009] After the ball milling is completed, the grinding balls are separated using a 100-mesh sieve, and then the unreacted fine powder is removed by air flow classification with a cut particle size of 5 μm. Finally, the product is subjected to Soxhlet extraction with methanol for 6-8 hours, the extraction temperature is 65±2°C, and the reflux rate is controlled at 3-5 drops / second. The obtained extract is subjected to supercritical CO2 drying treatment at 40±0.5°C and 8.0±0.2MPa for 1-3 hours, and the pressure release rate is controlled to be ≤0.5MPa / min to obtain modified carbon black.

[0010] Preferably, the flame retardant is a mixture of one or more of melamine cyanurate, decabromodiphenylethane, and magnesium hydroxide.

[0011] Preferably, the anti-aging agent is a mixture of one or more of antioxidant 1010, antioxidant 168, and antiozonant 4010NA.

[0012] Preferably, the Ti3AlC2 is pretreated before use, the steps are as follows:

[0013] A: Disperse LiF evenly in HCl solution and stir magnetically for 10 minutes until completely dissolved. Then add Ti3AlC2 powder and react at 40±2°C for 16-24 hours with stirring speed controlled at 200-300 rpm to obtain a reaction solution.

[0014] B: The reaction solution was centrifuged at 3500-4000 rpm for 5-10 min and washed with deionized water until the pH was ≥ 6. It was then dried at 60-65 ° C and -0.09 to -0.095 MPa for 10-12 h. Nitrogen was introduced during the drying process for protection to obtain multilayer Ti3C2T x ;

[0015] C: Multilayer Ti3C2T x Mix with tetramethylammonium hydroxide solution, stir at 200-300 rpm under nitrogen protection for 5-8 hours, then transfer to an ultrasonic tank, ultrasonicate in an ice-water bath for 1-2 hours, and finally centrifuge at 1500-2000 rpm for 10-15 minutes to obtain a dispersion;

[0016] D: Acetic acid was added to the dispersion to adjust the pH to 4-5, and then 3-aminopropyltriethoxysilane was added. The mixture was refluxed at 60-65°C for 5-8 hours, and then centrifuged and washed 2-3 times with an ethanol / water mixed solvent. The mixture was dried at 55-60°C and -0.09 to -0.095 MPa for 3-5 hours to obtain pretreated Ti3AlC2.

[0017] Preferably, the mass ratio of LiF to Ti3AlC2 powder is 1:1-1.05, the ratio of LiF to HCl solution is 1g:15-20mL, the concentration of HCl solution is 5-8%wt, and the multilayer Ti3C2T x The ratio of the amount of LiF added to the tetramethylammonium hydroxide solution is 1g:20-30mL, the concentration of the tetramethylammonium hydroxide solution is 20-30%wt, the ratio of the amount of LiF added to 3-aminopropyltriethoxysilane is 1g:10-15mL, and the volume ratio of ethanol to water in the ethanol / water mixed solvent is 9:1.

[0018] Preferably, the carbon black is first sieved through a 400-mesh sieve to remove large particles before modification, and then dried at 0.01-0.05 MPa and 60-80° C. for 4-6 hours to make the moisture content ≤0.5 wt%;

[0019] Preferably, zinc nitrate is ground to a D50 of ≤10 μm, and 2-methylimidazole is passed through a 200-mesh sieve.

[0020] Preferably, the silane coupling agent is prepared by compounding γ-aminopropyltriethoxysilane and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 2 to 3:1.

[0021] Preferably, the vulcanizing agent is a thiol-containing epoxy resin.

[0022] The second technical problem to be solved by the present invention is: to address the deficiencies in the prior art and provide a method for preparing a high thermal conductivity rubber, wherein the prepared high thermal conductivity rubber has good thermal conductivity, high dispersibility and overall performance of the rubber material.

[0023] In order to solve the above second technical problem, the technical solution of the present invention is:

[0024] A method for preparing high thermal conductivity rubber comprises the following steps:

[0025] S1. Place the methyl vinyl silicone rubber in an open mill and plasticize at 40±2°C and 30-50 rpm for 5-8 minutes;

[0026] S2. Then, hexagonal carbon nitride, aluminum oxide, Ti3AlC2, modified carbon black, molybdenum disulfide and graphite flakes were added in sequence and mixed at 60±5°C for 10-15 minutes;

[0027] S3. Continue adding flame retardant, dicyclopentadiene, lignin and anti-aging agent, and knead at 50±2℃ for 5-10min;

[0028] S4, adding silane coupling agent, reacting at 65-75 ° C for 5-8 minutes, wherein the silane coupling agent is added three times with an interval of 2 minutes;

[0029] S5. Add vulcanizing agent, carry out first-stage vulcanization at 170±2℃ and 10Mpa for 10-15min, then raise the temperature to 200±2℃ and continue second-stage vulcanization at normal pressure for 1.5-2.5h to obtain high thermal conductivity rubber.

[0030] The third technical problem to be solved by the present invention is: to provide an application of high thermal conductivity rubber in the field of tires in view of the shortcomings of the existing technology.

[0031] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] 1. Hexagonal carbon nitride has excellent intrinsic thermal conductivity, forming a continuous and dense thermal conductivity path together with graphite microplatelets and Ti3AlC2. The flaky structure of hexagonal carbon nitride and graphite microplatelets can be stacked layer by layer in the rubber matrix. The pre-treated Ti3AlC2, as a two-dimensional transition metal carbon / nitride, fills it with a unique two-dimensional planar form. The three overlap each other, like building a high-speed "heat transfer channel", allowing heat to be transferred quickly, significantly improving the thermal conductivity of the rubber material. At the same time, fillers such as alumina and molybdenum disulfide can also help improve the thermal conductivity network, further enhancing the overall thermal conductivity effect.

[0033] 2. During tire operation, the rubber material generates a large amount of heat due to repeated deformation, a phenomenon known as heat generation. The hexagonal carbon nitride and Ti3AlC2 in the formula have excellent thermal stability and low dielectric loss characteristics, which can effectively suppress the internal friction of the rubber molecular chain during deformation. Molybdenum disulfide, as a solid lubricant, can reduce the frictional resistance between the filler and the rubber matrix, and between the fillers themselves, reducing the heat generated by friction. In addition, the realization of high thermal conductivity allows the generated heat to be dissipated in a timely manner, avoiding heat accumulation, thereby significantly reducing the heat generation of the rubber material, extending the service life of the tire, and improving safety in use.

[0034] 3. One end of the silane coupling agent molecule reacts chemically with the methyl vinyl silicone rubber matrix, while the other end binds to active groups on the surface of inorganic fillers such as hexagonal carbon nitride and alumina, forming a chemical bond. This effectively improves the compatibility between the filler and the rubber matrix. Furthermore, the modified carbon black undergoes special treatment to optimize its surface properties, enhancing its affinity with the rubber matrix and other fillers, thereby promoting the uniform dispersion of other fillers. Dicyclopentadiene can soften the rubber matrix, reduce its viscosity, and provide a better environment for filler dispersion. This allows fillers such as hexagonal carbon nitride and graphite microplatelets to be evenly distributed in the rubber matrix, avoiding agglomeration. This improves the mechanical properties, thermal conductivity, and other comprehensive properties of the rubber material, ensuring the stable application of high-thermal conductivity rubber in tire production. For example, the -NH2 of KH-550 (γ-aminopropyltriethoxysilane) and the epoxy group of KH-560 (γ-(2,3-epoxypropyloxy)propyltrimethoxysilane) undergo an addition reaction at 65-75°C to form a three-dimensional cross-linked network, simultaneously anchoring the filler and rubber molecular chains. The epoxy group of KH-560 participates in the peroxide vulcanization reaction, forming a synergistic cross-linking network with the vulcanizer, and increasing the cross-linking density.

[0035] 4. Etch the Al layer in Ti3AlC2 with LiF / HCl solution to form multilayer Ti3C2T x , tetramethylammonium hydroxide solution is inserted into the interlayer and ultrasonic treatment is performed, which can further peel off into a few layers or even a single layer of Ti3C2T x Layer, adding Ti3C2T x The specific surface area of ​​Ti3C2T is large, exposing more active sites. By grafting 3-aminopropyltriethoxysilane, x Organic functional groups such as amino groups (-NH2) are introduced to the surface. These functional groups not only form chemical bonds with the silane coupling agent but also physically entangle or chemically react with the rubber matrix, thereby enhancing interfacial bonding. Simultaneously, adjusting the pH to 4-5 promotes the hydrolysis and condensation of 3-aminopropyltriethoxysilane, improving grafting efficiency.

[0036] 5. Modified carbon black is treated with zinc nitrate and 2-methylimidazole to form a special metal-organic framework structure on its surface, which has more active sites and a unique micromorphology. When constructing a thermal conductive network with hexagonal carbon nitride, graphite microplatelets, and Ti3AlC2, the modified carbon black's special structure can closely overlap with the flaky hexagonal carbon nitride and graphite microplatelets, filling the gaps between them and making the thermal conductive path more continuous and dense. At the same time, the active sites on the surface of the modified carbon black can interact with the functional groups on the surface of Ti3AlC2 to form chemical bonds or physical adsorption, further enhancing the stability and thermal conductivity of the thermal conductive network. During tire use, this synergistically constructed high-efficiency thermal conductive network can quickly conduct away heat generated by friction, significantly improving the overall thermal conductivity of the rubber material. In addition, the modified carbon black can act as a "bridge" to promote the uniform dispersion of other fillers such as aluminum oxide and molybdenum disulfide in the methyl vinyl silicone rubber matrix. During the mixing process, the modified carbon black, with its excellent dispersibility and compatibility with other fillers, reduces agglomeration of fillers like alumina, ensuring a more even distribution of all fillers within the rubber matrix. Dicyclopentadiene softens the rubber matrix, reducing its viscosity, creating a more favorable environment for the modified carbon black to disperse other fillers. Together, these factors achieve high dispersibility, avoid performance defects caused by filler agglomeration, and enhance the overall performance of the rubber material. The surface modification enhances the bond between the modified carbon black and the rubber matrix. When subjected to external forces, the modified carbon black can share stress with hexagonal carbon nitride and alumina. When the rubber is stretched or torn, the modified carbon black and the high strength of hexagonal carbon nitride interact to disperse stress concentration points and inhibit crack propagation. Furthermore, molybdenum disulfide, acting as a solid lubricant, reduces internal friction and energy loss during rubber deformation. This synergistic effect with the modified carbon black allows the rubber to maintain high elasticity while improving mechanical properties such as tensile strength and tear strength, extending the tire's service life under challenging road conditions.

[0037] 6. Dicyclopentadiene has excellent fluidity and low viscosity, which can reduce viscosity during the rubber mixing process and facilitate even mixing of various raw materials. Furthermore, its molecules contain multiple double bonds, which can cross-link with rubber molecular chains to form a three-dimensional network structure. This cross-linked structure can enhance the rubber's mechanical properties, such as strength, hardness, and wear resistance. Furthermore, the cross-linking reaction improves the rubber's heat resistance and aging resistance, extending the service life of rubber products. Furthermore, dicyclopentadiene can form thermal conductive pathways within the rubber matrix, promoting heat transfer. When rubber is mixed with hexagonal carbon nitride or Ti3AlC2, dicyclopentadiene interacts with these materials, allowing them to disperse more efficiently within the rubber, thereby improving the thermal conductivity of the entire rubber material and helping to reduce heat buildup during use.

[0038] 7. Lignin has a certain degree of rigidity and hardness. When added to rubber, it can act as a filler, increasing the volume of the rubber and reducing costs. It can also improve the processing properties of rubber, making it easier to handle during mixing, molding, and other processing steps, thereby increasing production efficiency. The surface of lignin contains various active groups, such as hydroxyl and carboxyl groups, which can physically or chemically react with the rubber matrix and other additives, thereby improving the interfacial bonding between lignin and the rubber matrix. This good interfacial bonding helps to improve the mechanical properties of rubber materials, such as tensile strength and tear strength. Furthermore, lignin has a certain degree of thermal stability, which can improve the heat resistance of rubber to a certain extent. During the use of rubber products, especially in high-temperature environments, lignin can slow the thermal degradation of rubber and extend the service life of rubber products.

[0039] 8. The thiol groups (-SH) in thiolated epoxy resins and the vinyl groups (CH=CH2) in methyl vinyl silicone rubber undergo a "click chemistry" reaction at a relatively low first-stage vulcanization temperature, initially forming a crosslinked network. This allows for efficient crosslinking without the need for high temperatures and pressures, reducing energy consumption. During the second-stage vulcanization, the epoxy groups open and deeply crosslink with the remaining -SH groups. Simultaneously, the disulfide bonds (-SS-) in the thiolated epoxy resin dynamically recombine to release internal stress and prevent bubble formation. Furthermore, the (-SS-) bonds can break and recombine at the second-stage vulcanization temperature, imparting self-healing properties to the rubber and avoiding the embrittlement caused by excessive crosslinking with traditional vulcanizers. Furthermore, the polarity (-SH, epoxy groups) of the thiolated epoxy resin reacts with hydroxyl groups (-OH) or defect sites on the surface of fillers such as hexagonal carbon nitride, alumina, and Ti3AlC2, forming chemical bonds (such as -SO-Al), reducing interfacial thermal resistance and improving the continuity of the thermal path. Mercaptolated epoxy resin can cooperate with silane coupling agent to enhance the filler-rubber interface bonding through the reaction of -SH and -SiOR, thereby increasing the strength of the rubber material. In addition, the epoxy group can capture free radicals and cooperate with anti-aging agents to delay the oxidative degradation of silicone rubber at high temperature. DETAILED DESCRIPTION

[0040] The present invention will be further described below with reference to the embodiments. Example 1

[0041] Preparation of modified carbon black

[0042] Carbon black N330 was passed through a 400-mesh sieve and dried at 0.03 MPa and 70°C for 5 hours to a moisture content of ≤0.5 wt%. Zinc nitrate was ground and 2-methylimidazole was sieved. The three were then added to a three-dimensional mixer at a mass ratio of 1:1.5:3.3 and premixed at 70 rpm for 40 minutes. Ball milling was performed at 250 rpm for 0.7 hours, 350 rpm for 0.7 hours, and finally at 300 rpm for 1.7 hours. The particle size of the large zirconia grinding balls is 5 mm, the particle size of the small zirconia grinding balls is 3 mm, the volume ratio of the large zirconia grinding balls to the small zirconia grinding balls is 3:2, and the ball-to-material ratio is 10:1; after the ball milling, a 100-mesh sieve is used to separate the grinding balls, and then the unreacted fine powder is removed by air flow classification with a cut particle size of 5 μm. Finally, the product is extracted with methanol Soxhlet for 7 hours, the extraction temperature is 65±2°C, and the reflux rate is controlled at 4 drops / second. The extracted product is supercritical CO2 dried at 40±0.5°C and 8.0±0.2MPa for 2 hours, and the pressure release rate is controlled to be ≤0.5MPa / min to obtain modified carbon black.

[0043] Preparation of high thermal conductivity rubber

[0044] 60 parts of methyl vinyl silicone rubber were plasticized at 40±2℃ and 40rpm for 6min; 25 parts of hexagonal carbon nitride, 12 parts of aluminum oxide, 7 parts of Ti3AlC2 powder, 7 parts of modified carbon black, 3 parts of molybdenum disulfide and 7 parts of graphite flakes were added in sequence and mixed at 60±5℃ for 12min; 7 parts of flame retardant (decabromodiphenyl ethane and magnesium hydroxide were mixed at a ratio of 1:1), 2 parts of dicyclopentadiene, 3 parts of lignin and 0.7 parts of antioxidant (antioxidant 168 and antiozonant 4010NA were mixed at a ratio of 1:1 by mass) were added and mixed at 50±2℃. Mix for 7 minutes; add 0.7 parts of silane coupling agent (γ-aminopropyltriethoxysilane (KH-550) and γ-(2,3-epoxypropyloxy)propyltrimethoxysilane (KH-560) in a mass ratio of 2.5:1) in three equal doses at intervals of 2 minutes, and react at 70°C for 6 minutes; add 4 parts of thiol epoxy resin, vulcanize at 170±2°C and 10Mpa for 12 minutes, raise the temperature to 200±2°C, and vulcanize at normal pressure for 2 hours to obtain high thermal conductivity rubber. Example 2

[0045] Preparation of modified carbon black

[0046] Carbon black N550 was passed through a 400-mesh sieve to remove large particles and dried at 0.01 MPa and 60°C for 4 hours to a moisture content of ≤0.5 wt%. Zinc nitrate was ground to a D50 of ≤10 μm, and 2-methylimidazole was passed through a 200-mesh sieve. The treated carbon black, zinc nitrate, and 2-methylimidazole were placed in a three-dimensional mixer at a mass ratio of 1:1.5:3.3 and premixed at 60 rpm for 30 minutes to obtain a mixed powder. Large zirconia grinding balls, mixed powder, and small zirconia grinding balls were loaded into a ball mill from bottom to top and milled at 250 rpm for 0.5 hour, then increased to 350 rpm for 0.5 hour, and finally reduced to 300 rpm for 1.5 hours. The large zirconia grinding balls had a particle size of 5 mm, and the small zirconia grinding balls had a particle size of 3 mm. The volume ratio of large to small zirconia grinding balls was 3:2, and the ball-to-material ratio was 10:1. After ball milling, the grinding balls were separated with a 100-mesh sieve, and unreacted fine powder was removed by air flow classification with a cut particle size of 5 μm. The product was then Soxhlet extracted with methanol for 6 h, with an extraction temperature of 65±2°C and a reflux rate of 3 drops / second. The extracted product was dried in supercritical CO2 at 40±0.5°C and 8.0±0.2 MPa for 1 h, with the pressure release rate controlled to be ≤0.5 MPa / min, to obtain modified carbon black.

[0047] Preparation of pretreated Ti3AlC2

[0048] LiF was evenly dispersed in HCl solution (concentration of 5% wt), the ratio of LiF to HCl solution added was 1g:15mL, magnetic stirring was performed for 10min until completely dissolved, Ti3AlC2 powder was added, the mass ratio of LiF to Ti3AlC2 powder was 1:1, and the reaction was carried out at 40±2℃ for 16h, with the stirring speed controlled at 200rpm to obtain a reaction solution. The reaction solution was centrifuged at 3500rpm for 5min and washed with deionized water to pH ≥ 6, and then dried at 60℃ and -0.09Mpa for 10h. Nitrogen was introduced during the drying process for protection to obtain multilayer Ti3C2T x . Multilayer Ti3C2T x Mixed with tetramethylammonium hydroxide solution (concentration of 20%wt), multilayer Ti3C2T xThe ratio of LiF to tetramethylammonium hydroxide solution was 1g:20mL, stirred at 200rpm under nitrogen protection for 5h, then transferred to an ultrasonic tank, ultrasonicated in an ice-water bath for 1h, and finally centrifuged at 1500rpm for 10min to obtain a dispersion. Acetic acid was added to the dispersion to adjust the pH to 4, and then 3-aminopropyltriethoxysilane was added. The ratio of LiF to 3-aminopropyltriethoxysilane was 1g:10mL, refluxed at 60℃ for 5h, and then centrifuged and washed twice with an ethanol / water mixed solvent (ethanol and water volume ratio of 9:1), and dried at 55℃ and -0.09 MPa for 3h to obtain pretreated Ti3AlC 2。

[0049] Preparation of high thermal conductivity rubber

[0050] Put 50 parts of methyl vinyl silicone rubber into an open mill and plasticize at 40±2℃ and 30rpm for 5 minutes; then add 20 parts of hexagonal carbon nitride, 10 parts of aluminum oxide, 5 parts of pretreated Ti3AlC2, 5 parts of modified carbon black, 2 parts of molybdenum disulfide and 5 parts of graphite microsheets in sequence and mix at 60±5℃ for 10 minutes; then add 5 parts of flame retardant (melamine cyanurate), 1 part of dicyclopentadiene, 2 parts of lignin and 0.5 parts of antioxidant (antioxidant 1010) and mix at 50±2℃ for 5 minutes. n; add 0.5 parts of silane coupling agent (γ-aminopropyltriethoxysilane (KH-550) and γ-(2,3-epoxypropyloxy)propyltrimethoxysilane (KH-560) in a mass ratio of 2:1), react at 65°C for 5 minutes, and add the silane coupling agent three times on average with an interval of 2 minutes; add 3 parts of thiol epoxy resin, vulcanize at 170±2°C and 10 MPa for 10 minutes, then raise the temperature to 200±2°C and continue vulcanization at normal pressure for 1.5 hours to obtain a high thermal conductive rubber. Example 3

[0051] Preparation of modified carbon black

[0052] Carbon black N330 was passed through a 400-mesh sieve and dried at 0.03 MPa and 70°C for 5 hours to a moisture content of ≤0.5 wt%. Zinc nitrate was ground and 2-methylimidazole was sieved. The three were then added to a three-dimensional mixer at a mass ratio of 1:1.5:3.3 and premixed at 70 rpm for 40 minutes. Ball milling was performed at 250 rpm for 0.7 hours, 350 rpm for 0.7 hours, and finally at 300 rpm for 1.7 hours. The particle size of the large zirconia grinding balls is 5 mm, the particle size of the small zirconia grinding balls is 3 mm, the volume ratio of the large zirconia grinding balls to the small zirconia grinding balls is 3:2, and the ball-to-material ratio is 10:1; after the ball milling, a 100-mesh sieve is used to separate the grinding balls, and then the unreacted fine powder is removed by air flow classification with a cut particle size of 5 μm. Finally, the product is extracted with methanol Soxhlet for 7 hours, the extraction temperature is 65±2°C, and the reflux rate is controlled at 4 drops / second. The extracted product is supercritical CO2 dried at 40±0.5°C and 8.0±0.2MPa for 2 hours, and the pressure release rate is controlled to be ≤0.5MPa / min to obtain modified carbon black.

[0053] Preparation of pretreated Ti3AlC2

[0054] LiF was evenly dispersed in HCl solution and magnetically stirred for 10 minutes until completely dissolved. Ti3AlC2 powder was continuously added and reacted at 40±2°C for 18 hours with a stirring speed of 250 rpm to obtain a reaction solution, wherein the mass ratio of LiF to Ti3AlC2 powder was 1:1-1.02, the ratio of LiF to HCl solution was 1 g:17 mL, and the concentration of the HCl solution was 6% wt;

[0055] The reaction solution was centrifuged at 3700 rpm for 7 min and washed with deionized water until the pH was ≥ 6. It was then dried at 62 °C and -0.095 MPa for 11 h. During the drying process, nitrogen was introduced for protection to obtain multilayer Ti3C2T x ;

[0056] Multilayer Ti3C2T x It was mixed with tetramethylammonium hydroxide solution, stirred at 250 rpm for 7 h under nitrogen protection, then transferred to an ultrasonic tank, ultrasonicated in an ice-water bath for 1.5 h, and finally centrifuged at 1800 rpm for 12 min to obtain a dispersion, in which multilayer Ti3C2T x The ratio of the amount of tetramethylammonium hydroxide solution added is 1g:25mL, and the concentration of the tetramethylammonium hydroxide solution is 25%wt;

[0057] Acetic acid was added to the dispersion to adjust the pH to 5, and then 3-aminopropyltriethoxysilane was added. The mixture was refluxed at 62°C for 7 hours, and then centrifuged and washed three times with an ethanol / water mixed solvent. The mixture was dried at 57°C and -0.095 MPa for 4 hours to obtain Ti3AlC2, wherein the ratio of LiF to 3-aminopropyltriethoxysilane added was 1 g:12 mL, and the volume ratio of ethanol to water in the ethanol / water mixed solvent was 9:1.

[0058] Preparation of high thermal conductivity rubber

[0059] 60 parts of methyl vinyl silicone rubber were masticated at 40 ± 2°C and 40 rpm for 6 minutes; 25 parts of hexagonal carbon nitride, 12 parts of aluminum oxide, 7 parts of pretreated Ti3AlC2, 7 parts of modified carbon black, 3 parts of molybdenum disulfide and 7 parts of graphite flakes were added in sequence and mixed at 60 ± 5°C for 12 minutes; 7 parts of flame retardant (a mixture of decabromodiphenylethane and magnesium hydroxide in a ratio of 1:1), 2 parts of dicyclopentadiene, 3 parts of lignin and 0.7 parts of antioxidant (a mixture of antioxidant 168 and antiozonant 4010NA in a ratio of 1:1 by mass) were added and mixed at 50 ± 2°C for 7 minutes; 0.7 parts of silane coupling agent (γ-aminopropyltriethoxysilane (KH-550) and γ-(2,3-epoxypropyloxy)propyltrimethoxysilane (KH-560) in a mass ratio of 2.5:1) were added three times at an interval of 2 minutes and reacted at 70°C for 6 minutes; 4 parts of thiol epoxy resin were added, and the mixture was vulcanized at 170±2°C and 10 MPa for 12 minutes. The temperature was raised to 200±2°C and vulcanized at normal pressure for 2 hours to obtain a high thermal conductive rubber. Example 4

[0060] Preparation of modified carbon black

[0061] Carbon black N330 was sieved through a 400-mesh sieve to remove large particles, and then dried at 0.04 MPa and 75°C for 5 h to make the moisture content ≤ 0.5 wt%. Zinc nitrate was ground to a D50 of ≤ 10 μm, and 2-methylimidazole was sieved through a 200-mesh sieve.

[0062] The treated carbon black, zinc nitrate and 2-methylimidazole were placed in a three-dimensional mixer at a mass ratio of 1:1.5:3.3, and premixed at a speed of 75 rpm for 45 minutes to obtain a mixed powder;

[0063] Large zirconia grinding balls, mixed powder and small zirconia grinding balls were loaded into a ball mill in order from bottom to top, and ball milled at 250 rpm for 1 hour, then increased to 350 rpm for 0.8 hour, and finally reduced to 300 rpm for 2 hours. The particle size of the large zirconia grinding balls was 5 mm, the particle size of the small zirconia grinding balls was 3 mm, the volume ratio of the large zirconia grinding balls to the small zirconia grinding balls was 3:2, and the ball-to-material ratio was 10:1.

[0064] After the ball milling, the grinding balls were separated using a 100-mesh sieve, and then the unreacted fine powder was removed by air flow classification with a cut particle size of 5 μm. Finally, the product was extracted with methanol Soxhlet for 8 hours, the extraction temperature was 65±2°C, and the reflux rate was controlled at 5 drops / second. The obtained extract was dried in supercritical CO2 at 40±0.5°C and 8.0±0.2MPa for 3 hours, and the pressure release rate was controlled to be ≤0.5MPa / min to obtain modified carbon black.

[0065] Preparation of pretreated Ti3AlC2

[0066] LiF was evenly dispersed in HCl solution and magnetically stirred for 10 minutes until completely dissolved. Ti3AlC2 powder was continuously added and reacted at 40±2°C for 22 hours with a stirring speed of 260 rpm to obtain a reaction solution, wherein the mass ratio of LiF to Ti3AlC2 powder was 1:1.05, the ratio of LiF to HCl solution was 1 g:20 mL, and the concentration of the HCl solution was 8% wt;

[0067] The reaction solution was centrifuged at 4000 rpm for 9 min and washed with deionized water until the pH was ≥ 6. It was then dried at 65 °C and -0.095 MPa for 12 h. During the drying process, nitrogen was introduced for protection to obtain multilayer Ti3C2T x ;

[0068] Multilayer Ti3C2T x It was mixed with tetramethylammonium hydroxide solution, stirred at 280 rpm for 7 h under nitrogen protection, then transferred to an ultrasonic tank, ultrasonicated in an ice-water bath for 2 h, and finally centrifuged at 1700 rpm for 14 min to obtain a dispersion, in which multilayer Ti3C2T x The ratio of the amount of tetramethylammonium hydroxide solution added is 1 g: 27 mL, and the concentration of the tetramethylammonium hydroxide solution is 28% wt;

[0069] Acetic acid was added to the dispersion to adjust the pH to 4, and then 3-aminopropyltriethoxysilane was added. The mixture was refluxed at 65°C for 8 hours, and then centrifuged and washed twice with an ethanol / water mixed solvent. The mixture was dried at 59°C and -0.09 MPa for 5 hours to obtain pretreated Ti3AlC2, wherein the ratio of LiF to 3-aminopropyltriethoxysilane added was 1 g:14 mL, and the volume ratio of ethanol to water in the ethanol / water mixed solvent was 9:1.

[0070] Preparation of high thermal conductivity rubber

[0071] 65 parts of methyl vinyl silicone rubber were plasticized at 40±2℃ and 50rpm for 8 minutes; 28 parts of hexagonal carbon nitride, 12 parts of aluminum oxide, 8 parts of pretreated Ti3AlC2, 8 parts of modified carbon black, 4 parts of molybdenum disulfide and 9 parts of graphite microplatelets were added and mixed at 60±5℃ for 15 minutes; 7 parts of flame retardant (melamine cyanurate, decabromodiphenylethane, magnesium hydroxide were mixed in a ratio of 1:1:1), 3 parts of dicyclopentadiene, 4 parts of lignin and 0.7 parts of antioxidant (antioxidant 1010, antioxidant 168, antiozonant 4010NA were mixed in a ratio of 1:1:1 by mass) were added and mixed at 50±2℃ for 10 minutes; 0.7 parts of silane coupling agent (γ-aminopropyltriethoxysilane (KH-550) and γ-(2,3-epoxypropyloxy)propyltrimethoxysilane (KH-560) were mixed in a ratio of 3:1 by mass) were added. Compounding) Add three times with an interval of 2 minutes, react at 75℃ for 8 minutes; add 5 parts of mercaptolated epoxy resin, vulcanize at 170±2℃ and 10Mpa for 15 minutes, and vulcanize at 200±2℃ and normal pressure for 2.5 hours to obtain high thermal conductive rubber. Example 5

[0072] Preparation of modified carbon black

[0073] Carbon black N330 was sieved through a 400-mesh sieve to remove large particles, and then dried at 0.05 MPa and 80°C for 6 h to reduce the moisture content to ≤ 0.5 wt%. Zinc nitrate was ground to a D50 of ≤ 10 μm, and 2-methylimidazole was sieved through a 200-mesh sieve.

[0074] The treated carbon black, zinc nitrate and 2-methylimidazole were placed in a three-dimensional mixer at a mass ratio of 1:1.5:3.3, and premixed at a speed of 80 rpm for 50 minutes to obtain a mixed powder;

[0075] Large zirconia grinding balls, mixed powder and small zirconia grinding balls were loaded into a ball mill in order from bottom to top, and ball milled at 250 rpm for 1 hour, then increased to 350 rpm for 1 hour, and finally reduced to 300 rpm for 2 hours. The particle size of the large zirconia grinding balls was 5 mm, the particle size of the small zirconia grinding balls was 3 mm, the volume ratio of the large zirconia grinding balls to the small zirconia grinding balls was 3:2, and the ball-to-material ratio was 10:1.

[0076] After the ball milling, the grinding balls were separated using a 100-mesh sieve, and then the unreacted fine powder was removed by air flow classification with a cut particle size of 5 μm. Finally, the product was extracted with methanol Soxhlet for 8 hours, the extraction temperature was 65±2°C, and the reflux rate was controlled at 5 drops / second. The obtained extract was dried in supercritical CO2 at 40±0.5°C and 8.0±0.2MPa for 3 hours, and the pressure release rate was controlled to be ≤0.5MPa / min to obtain modified carbon black.

[0077] Preparation of pretreated Ti3AlC2

[0078] LiF was evenly dispersed in HCl solution and magnetically stirred for 10 minutes until completely dissolved. Ti3AlC2 powder was continuously added and reacted at 40±2°C for 24 hours with a stirring speed of 300 rpm to obtain a reaction solution, wherein the mass ratio of LiF to Ti3AlC2 powder was 1:1.05, the ratio of LiF to HCl solution was 1 g:20 mL, and the concentration of the HCl solution was 8% wt;

[0079] The reaction solution was centrifuged at 4000 rpm for 10 min and washed with deionized water until the pH was ≥ 6. It was then dried at 65 °C and -0.095 MPa for 12 h. During the drying process, nitrogen was introduced for protection to obtain multilayer Ti3C2T x ;

[0080] Multilayer Ti3C2T x It was mixed with tetramethylammonium hydroxide solution, stirred at 300 rpm for 8 h under nitrogen protection, then transferred to an ultrasonic tank, ultrasonicated in an ice-water bath for 2 h, and finally centrifuged at 2000 rpm for 15 min to obtain a dispersion, in which multilayer Ti3C2T x The ratio of the amount of tetramethylammonium hydroxide solution added is 1g:30mL, and the concentration of the tetramethylammonium hydroxide solution is 30%wt;

[0081] Acetic acid was added to the dispersion to adjust the pH to 5, and then 3-aminopropyltriethoxysilane was added. The mixture was refluxed at 65°C for 8 hours, and then centrifuged and washed three times with an ethanol / water mixed solvent. The mixture was dried at 60°C and -0.095 MPa for 5 hours to obtain pretreated Ti3AlC2, wherein the ratio of LiF to 3-aminopropyltriethoxysilane added was 1 g:15 mL, and the volume ratio of ethanol to water in the ethanol / water mixed solvent was 9:1.

[0082] Preparation of high thermal conductivity rubber

[0083] 70 parts of methyl vinyl silicone rubber were plasticized at 40±2℃ and 35rpm for 6min; 30 parts of hexagonal carbon nitride, 15 parts of alumina, 10 parts of pretreated Ti3AlC2, 10 parts of modified carbon black, 4 parts of molybdenum disulfide and 10 parts of graphite flakes were added and mixed at 60±5℃ for 11min; 10 parts of flame retardant (melamine cyanurate and decabromodiphenylethane were mixed at a ratio of 1:1), 3 parts of dicyclopentadiene, 5 parts of lignin and 1 part of cellulose were added. The mixture was stirred for 1 h at 50 ± 2 ° C for 6 min. The mixture was mixed with 1 part of antioxidant (antioxidant 1010 and antioxidant 168 in a ratio of 1:1), and kneaded at 50 ± 2 ° C for 6 min. 1 part of silane coupling agent (γ-aminopropyltriethoxysilane (KH-550) and γ-(2,3-epoxypropyloxy)propyltrimethoxysilane (KH-560) in a mass ratio of 2.2:1) was added and reacted at 67 ° C for 6 min. 3.5 parts of mercaptolated epoxy resin were added and vulcanized at 170 ± 2 ° C and 10 MPa for 11 min. Then, the mixture was vulcanized at 200 ± 2 ° C under normal pressure for 1.8 h to obtain a high thermal conductive rubber. Comparative Example 1

[0084] Carbon black N330 was not modified, and the rest was exactly the same as in Example 3. Comparative Example 2

[0085] Hexagonal carbon nitride was not used, and the rest was exactly the same as in Example 3. Comparative Example 3

[0086] Ti3AlC2 was not used, and the rest was exactly the same as in Example 3. Comparative Example 4

[0087] No modified carbon black was used (no carbon black was present in the raw materials), and the rest was exactly the same as in Example 3. Comparative Example 5

[0088] No lignin was used, and the rest was exactly the same as in Example 3. Comparative Example 6

[0089] The mercaptolated epoxy resin was replaced by sulfur, and the rest was exactly the same as in Example 3.

[0090] The performance of the high thermal conductivity rubber in Examples 1-5 and Comparative Examples 1-6 was tested, and the results are as follows:

[0091] Table 1

[0092]

[0093] It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

Claims

1. A high thermal conductivity rubber, characterized in that: The invention comprises the following raw materials in parts by weight: 50-70 parts of methyl vinyl silicone rubber, 20-30 parts of hexagonal carbon nitride, 25-10 parts of Ti3AlC, 10-15 parts of alumina, 2-4 parts of molybdenum disulfide, 5-10 parts of graphite microplatelets, 5-10 parts of modified carbon black, 0.5-1 part of silane coupling agent, 3-5 parts of vulcanizing agent, 5-10 parts of flame retardant, 1-3 parts of dicyclopentadiene, 2-5 parts of lignin, and 0.5-1 part of anti-aging agent; Wherein, the preparation method of the modified carbon black is: Place carbon black, zinc nitrate, and 2-methylimidazole in a three-dimensional mixer at a mass ratio of 1:1.5:3.3, and premix at a speed of 60-80 rpm for 30-50 minutes to obtain a mixed powder; The large zirconia grinding balls, mixed powder and small zirconia grinding balls are loaded into a ball mill in order from bottom to top, and the ball milling is carried out at 250 rpm for 0.5-1 h, then the speed is increased to 350 rpm for 0.5-1 h, and finally the speed is reduced to 300 rpm for 1.5-2 h. The particle size of the large zirconia grinding balls is 5 mm, the particle size of the small zirconia grinding balls is 3 mm, the volume ratio of the large zirconia grinding balls to the small zirconia grinding balls is 3:2, and the ball-to-material ratio is 10:

1. After the ball milling, the grinding balls were separated using a 100-mesh sieve, and then unreacted fine powder was removed by air flow classification with a cut-off particle size of 5 μm. Finally, the product was subjected to Soxhlet extraction with methanol for 6-8 hours at an extraction temperature of 65±2°C and a reflux rate of 3-5 drops / second. The obtained extract was subjected to supercritical CO2 drying at 40±0.5°C and 8.0±0.2MPa for 1-3 hours, with a pressure relief rate of ≤0.5MPa / min, to obtain modified carbon black. The Ti3AlC2 is pretreated before use, and the steps are as follows: A: Disperse LiF evenly in HCl solution and stir magnetically for 10 minutes until completely dissolved. Then add Ti3AlC2 powder and react at 40±2°C for 16-24 hours with stirring speed controlled at 200-300 rpm to obtain a reaction solution. B: The reaction solution was centrifuged at 3500-4000 rpm for 5-10 min and washed with deionized water until the pH was ≥ 6. It was then dried at 60-65 ° C and -0.09 to -0.095 MPa for 10-12 h. Nitrogen was introduced during the drying process for protection to obtain multilayer Ti3C2T x ; C: Multilayer Ti3C2T x Mix with tetramethylammonium hydroxide solution, stir at 200-300 rpm under nitrogen protection for 5-8 hours, then transfer to an ultrasonic tank, ultrasonicate in an ice-water bath for 1-2 hours, and finally centrifuge at 1500-2000 rpm for 10-15 minutes to obtain a dispersion; D: Acetic acid was added to the dispersion to adjust the pH to 4-5, and then 3-aminopropyltriethoxysilane was added. The mixture was refluxed at 60-65°C for 5-8 hours, and then centrifuged and washed 2-3 times with an ethanol / water mixed solvent. The mixture was dried at 55-60°C and -0.09 to -0.095 MPa for 3-5 hours to obtain pretreated Ti3AlC2.

2. The high thermal conductivity rubber according to claim 1, characterized in that: The flame retardant is a mixture of one or more of melamine cyanurate, decabromodiphenylethane and magnesium hydroxide.

3. The high thermal conductivity rubber according to claim 1, characterized in that: The anti-aging agent is a mixture of one or more of antioxidant 1010, antioxidant 168, and antiozonant 4010NA.

4. The high thermal conductivity rubber according to claim 1, characterized in that: The mass ratio of LiF to Ti3AlC2 powder is 1:1-1.05, the addition ratio of LiF to HCl solution is 1g:15-20mL, the concentration of the HCl solution is 5-8%wt, and the multilayer Ti3C2T x The ratio of the amount of LiF added to the tetramethylammonium hydroxide solution is 1g:20-30mL, the concentration of the tetramethylammonium hydroxide solution is 20-30%wt, the ratio of the amount of LiF added to 3-aminopropyltriethoxysilane is 1g:10-15mL, and the volume ratio of ethanol to water in the ethanol / water mixed solvent is 9:

1.

5. The high thermal conductivity rubber according to claim 1, characterized in that: Before modification, the carbon black was sieved through a 400-mesh sieve to remove large particles, and then dried at 0.01-0.05 MPa and 60-80°C for 4-6 hours to make the moisture content ≤0.5wt%; Zinc nitrate was ground to D50≤10μm, and 2-methylimidazole was passed through a 200-mesh sieve.

6. The high thermal conductivity rubber according to claim 1, characterized in that: The silane coupling agent is prepared by compounding γ-aminopropyltriethoxysilane and γ-(2,3-epoxypropoxy)propyltrimethoxysilane in a mass ratio of 2 to 3:

1.

7. The high thermal conductivity rubber according to claim 1, characterized in that: The vulcanizing agent is a mercapto-epoxy resin.

8. The method for preparing the high thermal conductivity rubber according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Place the methyl vinyl silicone rubber in an open mill and plasticize at 40±2°C and 30-50 rpm for 5-8 minutes; S2. Then, hexagonal carbon nitride, aluminum oxide, Ti3AlC2, modified carbon black, molybdenum disulfide and graphite flakes were added in sequence and mixed at 60±5°C for 10-15 minutes; S3. Continue adding flame retardant, dicyclopentadiene, lignin and anti-aging agent, and knead at 50±2℃ for 5-10min; S4, adding silane coupling agent, reacting at 65-75 ° C for 5-8 minutes, wherein the silane coupling agent is added three times with an interval of 2 minutes; S5. Add vulcanizing agent, carry out first-stage vulcanization at 170±2℃ and 10Mpa for 10-15min, then raise the temperature to 200±2℃ and continue second-stage vulcanization at normal pressure for 1.5-2.5h to obtain high thermal conductivity rubber.

9. Use of the high thermal conductivity rubber according to any one of claims 1 to 7 in the field of tires.

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