Rubber composition for tire support and its preparation method and tire

Abstract

This invention provides a tire support rubber composition, its preparation method, and a tire, relating to the technical field of rubber manufacturing methods. The composition includes 100 parts of rubber compound; 35-65 parts of carbon black; 5-8 parts of activator; 3-6 parts of vulcanizing agent; and 1-8 parts of metal powder. The preparation method includes adding the rubber compound to a mixer, closing the mixer, and starting pressure; raising the pressure plate and adding carbon black to the pressurized rubber; mixing for 10-15 minutes, then sequentially adding the activator, metal powder, and vulcanizing agent, and continuing mixing for 15-25 minutes; stirring the mixed rubber for 1-1.5 minutes and then discharging the rubber to obtain the tire support rubber composition. This invention alleviates the technical problem in the prior art where the rubber composition cannot meet the performance requirements of the upper and lower triangle rubber in the bead and the pad rubber in the tire shoulder, achieving the technical effect of increasing tire service life.

Description

Technical Field

[0001] This invention relates to the field of rubber manufacturing methods, specifically to a tire support rubber composition and its preparation method, and also to a tire prepared using the tire support rubber composition. Background Technology

[0002] The rubber support of the tire includes the bead and the shoulder. The bead, as an important part of the tire mounting on the rim, plays a role in bearing the tensile force brought by the internal pressure, overcoming the lateral force of the tire when cornering, and preventing the tire from detaching from the rim. The shoulder is the transition area between the tire crown and the sidewall.

[0003] The upper and lower triangular rubber sections of the tire bead are the main components of the bead rubber. Under complex and varied road conditions, such as bumpy roads, potholes, and frequent acceleration, deceleration, and steering, the upper triangular rubber will be subjected to great stress and deformation. Over time, this will lead to premature fatigue cracks, significantly shortening the tire's lifespan. The lower triangular rubber, in addition to needing good hardness, rigidity, and tear resistance, must also overcome the heat generated by friction during driving. Excessive temperature accelerates rubber aging, causing its performance to decline continuously, seriously affecting the tire's reliability and durability.

[0004] The rubber padding in the tire shoulder needs to improve the tire shoulder's impact resistance to prevent the tire from being punctured by sharp objects during driving and to protect other tire components from damage; reducing heat generation can reduce the negative impact of heat accumulation on tire performance and ensure that the tire can operate stably under various working conditions.

[0005] However, the types of rubber composite materials used in the tire support components, such as the bead (upper and lower tread rubber) or shoulder (shoulder rubber), are relatively limited in existing technologies, restricting performance improvements. They cannot adequately meet the specific performance requirements of different parts, thus affecting tire lifespan. Summary of the Invention

[0006] The purpose of this invention is to provide a rubber composition for tire support parts, so as to alleviate the technical problem that the existing rubber compositions cannot meet the performance requirements of the upper triangular rubber, lower triangular rubber and pad rubber, thus affecting the service life of the tire.

[0007] Another object of the present invention is to provide a method for preparing a rubber composition for a tire support portion.

[0008] Another object of the present invention is to provide a tire that uses a tire support rubber composition as a tire bead or tire shoulder.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows:

[0010] This invention provides a rubber composition for a tire support portion;

[0011] It consists of the following components in parts by weight:

[0012] 100 parts rubber compound; 35-65 parts carbon black; 5-8 parts activator; 3-6 parts vulcanizing agent; 1-8 parts metal powder.

[0013] Furthermore, the rubber compound includes at least one of natural rubber and butadiene rubber.

[0014] Furthermore, the activator includes zinc oxide and stearic acid; zinc oxide is 2 to 7 parts and stearic acid is 1 to 3 parts.

[0015] Furthermore, the vulcanizing agent includes an accelerator and sulfur; the accelerator is 0.8 to 3 parts, and the sulfur is 2.2 to 5.2 parts.

[0016] Furthermore, the accelerator includes at least one of sulfenamides, thiazoles, thiurams, thioureas, dithiocarbamates, aldehydes, guanidines, or xanthates.

[0017] Furthermore, the metal powder is iron powder, and the particle size D50 of the iron powder is 0.5μm to 1μm.

[0018] The present invention also provides a method for preparing a rubber composition for a tire support portion, comprising the following steps:

[0019] Includes the following steps:

[0020] Step 1: Add 100 parts of rubber compound to the internal mixer, turn off the internal mixer, start pressurizing, and obtain pressurized rubber.

[0021] Step 2: Raise the pressure block and add 35-65 parts of carbon black to the pressurized rubber; stir for 10-15 minutes, then add 5-8 parts of activator, 1-8 parts of metal powder and 3-6 parts of vulcanizing agent in sequence, and continue to mix for 15-25 minutes to obtain the compound.

[0022] Step 3: Stir the rubber compound for 1 to 1.5 minutes and then discharge the rubber to obtain the tire support rubber composition.

[0023] Furthermore, the pressure applied in step 1 is 10MPa to 15MPa, and the pressurization time is 50s to 65s.

[0024] Furthermore, in step 2, the mixing speed is 30 r / min to 35 r / min, and the mixing temperature is 100℃ to 130℃.

[0025] The present invention also provides a tire, a tire bead or tire shoulder of a tire support portion, which is prepared using a tire support portion rubber composition.

[0026] Beneficial effects:

[0027] This invention comprises the following components by weight: 100 parts rubber compound; 35-65 parts carbon black; 5-8 parts activator; 3-6 parts vulcanizing agent; and 1-8 parts metal powder. Adding 35-65 parts carbon black improves the tensile strength and tear strength of the rubber composition for the tire support section. Through the vulcanizing agent and activator, the rubber composition used in the tire support section of this invention exhibits good aging resistance. During frequent acceleration, deceleration, and steering operations, the upper triangular rubber is prone to stress concentration, leading to tearing. The addition of 1-8 parts metal powder improves its tear resistance, reduces fatigue crack formation, enhances fatigue resistance, and improves thermal conductivity, thereby extending the service life of the upper triangular rubber. Applying 1-8 parts metal powder to the lower triangular rubber improves thermal conductivity, hardness, and rigidity, enhancing the fatigue performance of the compound. Applying 1-8 parts metal powder to the pad rubber improves impact resistance and reduces heat generation.

[0028] The preparation method of the rubber composition for the tire support section of this invention is simple and easy to manufacture. This invention meets the performance requirements of the upper and lower triangular rubbers in the tire bead and the padding rubber in the tire shoulder of the tire support section. Tires using the rubber composition prepared by this invention as the support section have a long service life and can improve the overall performance and safety of the tire. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 A flowchart illustrating a method for preparing a tire support rubber composition according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the structure of the upper triangular rubber, lower triangular rubber, and pad rubber in a tire, as provided in an embodiment of the present invention.

[0032] Attached label: 100 - Upper triangular adhesive; 200 - Lower triangular adhesive; 300 - Pad adhesive. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0034] In a first aspect, the present invention provides a tire support rubber composition; comprising, by weight, the following components:

[0035] The rubber compound consists of 100 parts; carbon black of 35-65 parts; activator of 5-8 parts; vulcanizing agent of 3-6 parts; and metal powder of 1-8 parts.

[0036] In embodiments of the present invention, the carbon black may be, but is not limited to, 35 parts, 45 parts or 65 parts by weight.

[0037] The activator may be, but is not limited to, 3.5 parts, 4.5 parts, or 6 parts by weight;

[0038] The vulcanizing agent can be, but is not limited to, 1 part, 1.3 parts, or 3.5 parts by weight;

[0039] The metal powder can be, but is not limited to, 1 part, 2 parts, 3 parts, 4 parts, 6 parts or 8 parts by weight.

[0040] It should be noted that the rubber compound, as a base material, is set at 100 parts, providing sufficient elasticity, flexibility, and adhesion for the tire bead or shoulder support. When applied to the tire bead, it ensures a tight fit to the rim and withstands various complex stresses and deformations during vehicle operation, providing a matrix support for other performance characteristics. The 100 parts rubber compound applied to the tire shoulder pad allows it to effectively absorb and buffer impacts from the road surface when subjected to dynamic loads during vehicle operation, maintaining good contact between the tire and the ground, and also helping to reduce tire fatigue damage caused by impacts.

[0041] It should be noted that adding 35-65 parts of carbon black can effectively improve the strength and hardness of the tire bead or shoulder without significantly increasing costs. This allows the tire bead or shoulder to maintain good shape and performance when subjected to tire friction and internal tire pressure, reducing wear and deformation and extending service life. Furthermore, 35-65 parts of carbon black can give the rubber compound suitable viscosity and flowability during processing, facilitating the uniform mixing of various raw materials during compounding and aiding in the shaping of the tire bead or shoulder during molding.

[0042] It should be noted that 3 to 6 parts of vulcanizing agent can enable the rubber molecular chains to form a moderately cross-linked structure. Insufficient cross-linking will result in soft bead or shoulder with poor strength properties; excessive cross-linking will cause the bead or shoulder to harden and become brittle, losing its elasticity. This dosage range allows the bead or shoulder to achieve good strength, elasticity, heat resistance, and aging resistance, balancing the various properties of the bead or shoulder.

[0043] It should be noted that 1 to 8 parts of metal powder are applied to the upper triangular rubber in the tire bead. The good thermal conductivity of the metal powder is used to improve the thermal conductivity of the upper triangular rubber, so that the heat inside the tire can be dissipated quickly, reducing the tire temperature and improving fatigue resistance.

[0044] When applied to the lower tread bead, it increases the hardness and rigidity of the lower tread bead, enhances its resistance to deformation, helps improve structural stability, and strengthens its supporting function.

[0045] When applied to tire shoulder pads, it can improve the impact resistance of the pads. The presence of metal powder increases the density and strength of the pads, enabling them to better resist external forces when subjected to impact. It may also help reduce the heat generation of the pads and improve their performance.

[0046] In embodiments of the present invention, the rubber matrix includes one or more of natural rubber and butadiene rubber. For example, it can be natural rubber, butadiene rubber, or a mixture of the above.

[0047] In embodiments of the present invention, the activator comprises 2 to 7 parts of zinc oxide and 1 to 3 parts of stearic acid; for example, it may be 4 parts of zinc oxide and 3 parts of stearic acid.

[0048] In embodiments of the present invention, the vulcanizing agent comprises 0.8 to 3 parts of accelerator and 2.2 to 5.2 parts of sulfur; for example, 1 part of accelerator and 2.5 parts of sulfur can be mixed.

[0049] In embodiments of the present invention, the accelerator includes at least one selected from sulfenamides, thiazoles, thiurams, thioureas, dithiocarbamates, aldehyde amines, guanidines, or xanthates. For example, it can be a thiazole, a thiuram, or a mixture of the above.

[0050] In embodiments of the present invention, the metal powder is iron powder with a particle size D50 of 0.5 μm to 1 μm. Preferably, it is 1 μm. When the median particle size is between 0.5 and 1 μm, it is easily and uniformly dispersed in the natural rubber or butadiene rubber matrix under the shear force of the internal mixer. It forms a thermally conductive path in the upper triangular rubber, increasing the thermal conductivity by 28% compared to when it is not added, effectively reducing heat accumulation caused by stress concentration, reducing crack initiation, and extending fatigue life. It stabilizes the hardness of the lower triangular rubber at Shore hardness 91, which can enhance rigidity to withstand internal pressure and lateral forces, while increasing thermal conductivity by 36.7% and inhibiting high-temperature aging. As a rigidity-enhancing node in the padding rubber, it increases the thermal diffusivity by 25%, accelerates heat dissipation, improves impact resistance, and increases the hardness to Shore hardness 65, effectively resisting puncture by sharp objects. If the particle size is too large (e.g., 40-50 μm iron powder), the dispersion efficiency decreases, resulting in filler accumulation, causing fluctuations in thermal conductivity and deterioration in processing performance.

[0051] Secondly, such as Figure 1 As shown, the present invention provides a method for preparing a rubber composition for a tire support portion, which includes the following steps:

[0052] Step 1: Add 100 parts of rubber compound to the internal mixer, turn off the internal mixer, and start pressurizing to obtain pressurized rubber; the pressurization pressure is 10MPa~15MPa, and the pressurization time is 50s~65s.

[0053] Step 2: Raise the pressure block and add 35-45 parts of carbon black to the pressurized rubber; stir for 10-15 minutes, then add 5-8 parts of activator, 1-8 parts of metal powder and 3-6 parts of vulcanizing agent in sequence, and continue to mix for 15-25 minutes to obtain the compound; the mixing speed is 30-35 r / min and the mixing temperature is 100℃-130℃.

[0054] Step 3: Stir the rubber compound for 1 to 1.5 minutes and then discharge the rubber to obtain the tire support rubber composition.

[0055] This invention applies a pressure treatment of 10MPa–15MPa for 50–65s to the rubber compound, improving its plasticity and making it easier to mix with other components. This ensures that all components are uniformly dispersed in the rubber matrix, avoiding local agglomeration or uneven mixing, and improving the processing performance and quality stability of the tire support rubber. A rotation speed of 330–35r / min and a temperature of 100–130℃ ensure that the rubber is fully mixed with its components during the compounding process without being affected by excessive shearing or high temperature, which could negatively impact the rubber's properties. This results in a compounded rubber with good flowability and plasticity, allowing for better mold filling during bead or shoulder molding, forming precisely sized, smooth-surfaced beads or shoulders, thus improving the molding quality and production efficiency of beads or shoulders.

[0056] Thirdly, the present invention also provides a tire that uses a tire support rubber composition as the tire support. The support bead includes an upper triangular rubber 100 and a lower triangular rubber 200, and the support shoulder includes a pad rubber 300 positioned on the tire as follows: Figure 2 As shown.

[0057] The features and performance of the present invention will be further described in detail below with reference to specific embodiments.

[0058] Example 1

[0059] This embodiment 1 provides a tire support bead rubber composition, which is the rubber at the upper triangular rubber 100, and is composed of the following components by weight: 100 parts rubber matrix; 45 parts carbon black; 6 parts activator (4 parts zinc oxide and 2 parts stearic acid); 4 parts vulcanizing agent (0.8 parts accelerator and 3.2 parts sulfur); and 1 part metal powder (0.5 μm particle size D50 iron powder).

[0060] The method for preparing the rubber composition in this embodiment includes: adding rubber compound to a mixer, closing the mixer, and starting pressure to obtain pressurized rubber; the pressure is 10 MPa, and the pressurization time is 50 s. Raising the pressure bar and adding carbon black to the pressurized rubber; stirring for 10 min, then sequentially adding an activator, metal powder, and vulcanizing agent, and continuing to mix for 15 min to obtain a compound; the mixing speed is 30 r / min, and the mixing temperature is 100℃. After stirring the compound for 1 min, discharging the rubber to obtain the bead rubber composition.

[0061] Example 2

[0062] This embodiment 2 provides a tire support bead rubber composition, which is the rubber at the upper triangular rubber 100, and is composed of the following components by weight: 45 parts carbon black; 5 parts activator (3 parts zinc oxide and 2 parts stearic acid); 3 parts vulcanizing agent (0.8 parts accelerator and 2.2 parts sulfur); and 2 parts metal powder (0.5 μm particle size D50 iron powder).

[0063] The preparation method of the rubber composition in this embodiment differs from that in Example 1 in that the pressure applied is 15 MPa and the pressing time is 65 s. After stirring for 15 min, the activator, metal powder, and vulcanizing agent are added sequentially, and the mixture is continuously kneaded for 25 min to obtain the compound; the kneading speed is 35 r / min, and the kneading temperature is 130℃. The compound is stirred for 1.5 min and then discharged.

[0064] Example 3

[0065] This embodiment 3 provides a tire support bead rubber composition, which is the rubber at the upper triangular rubber 100, and is composed of the following components by weight: 45 parts carbon black; 8 parts activator (5 parts zinc oxide and 3 parts stearic acid); 6 parts vulcanizing agent (2 parts accelerator and 4 parts sulfur); and 3 parts metal powder (iron powder with a particle size of 0.5 μm and a D50).

[0066] The preparation method of the rubber composition in this embodiment differs from that in Example 1 in that the pressure applied is 13 MPa and the pressing time is 60 s. After stirring for 13 min, the activator, metal powder, and vulcanizing agent are added sequentially, and the mixture is continuously kneaded for 20 min to obtain the compound; the kneading speed is 32 r / min, and the kneading temperature is 120℃. The compound is stirred for 1.2 min and then discharged.

[0067] Comparative Example 1

[0068] Comparative Example 1 provides a rubber composition for use in the triangular rubber 100 on the tire bead of the tire support section. The preparation method is the same as that of Example 1, except that no metal powder is added to the composition.

[0069] The bead triangular rubber compositions obtained in Examples 1-3 were compared with those in Comparative Example 1 in terms of thermal conductivity, fatigue life, and hardness. The results are shown in Table 1.

[0070] Tire bead (upper triangular corner rubber) Comparative Example 1 Example 1 Example 2 Example 3 Iron powder (parts) 0 1 2 3 Iron powder particle size D50 (μm) 0 0.5 0.5 0.5 Thermal conductivity (W / m·℃) 0.21 0.23 0.25 0.27 Fatigue life <![CDATA[2.6×10 7 ]]> <![CDATA[5.87×10 7 ]]> <![CDATA[5.16×10 7 ]]> <![CDATA[3.4×10 7 ]]>

[0071] Table 1

[0072] The data in Table 1 show that adding different amounts of iron powder to the upper triangular rubber of the tire bead affected its thermal conductivity and fatigue life. In Examples 1-3, as the amount of iron powder increased to 1, 2, and 3 parts, the thermal conductivity increased to 0.23 (W / m·℃), 0.25 (W / m·℃), and 0.27 (W / m·℃), respectively. For the upper triangular rubber of the bead, higher thermal conductivity means that the heat generated during tire operation can be dissipated more efficiently, reducing problems such as rubber aging and performance degradation caused by heat accumulation. This helps maintain the performance stability of the upper triangular rubber at high temperatures and extends the tire's service life.

[0073] Comparing the fatigue life of Comparative Example 1 with Examples 1-3, the fatigue life increased with the increase of iron powder content, indicating that under the current experimental conditions, adding iron powder can improve the fatigue resistance of the triangular rubber on the tire bead.

[0074] Example 4

[0075] This embodiment 4 provides a tire support bead rubber composition, which is the rubber at the lower triangular rubber 200, and is composed of the following components by weight: 100 parts of rubber matrix; 60 parts of carbon black; 5 parts of activator (3 parts of zinc oxide and 2 parts of stearic acid); 6 parts of vulcanizing agent (2 parts of accelerator and 4 parts of sulfur); and 4 parts of metal powder (iron powder with a particle size of 1 μm and a D50).

[0076] The preparation method of this embodiment includes: adding rubber compound to a mixer, closing the mixer, and starting pressure to obtain pressurized rubber; the pressure is 12 MPa, and the pressurization time is 55 s. Raising the pressure bar and adding carbon black to the pressurized rubber; stirring for 11 min, then sequentially adding an activator, metal powder, and vulcanizing agent, and continuing to mix for 16 min to obtain a compound; the mixing speed is 32 r / min, and the mixing temperature is 110℃. After stirring the compound for 1.5 min, the rubber is discharged to obtain a bead rubber composition.

[0077] Example 5

[0078] This embodiment 5 provides a tire support bead rubber composition, which is used as the rubber at the lower triangular rubber 200. It is composed of the following components by weight: 100 parts of rubber matrix; 55 parts of carbon black; 5 parts of activator (3.5 parts of zinc oxide and 1.5 parts of stearic acid); 6 parts of vulcanizing agent (0.8 parts of accelerator and 5.2 parts of sulfur); and 6 parts of metal powder (iron powder with a particle size of 1 μm and a D50).

[0079] The preparation method of Example 5 is the same as that of Example 4.

[0080] Example 6

[0081] This embodiment 6 provides a tire support bead rubber composition, which is used as the rubber at the lower triangular rubber 200. It is composed of the following components by weight: 100 parts of rubber matrix; 60 parts of carbon black; 5 parts of activator (3.5 parts of zinc oxide and 1.5 parts of stearic acid); 5 parts of vulcanizing agent (2 parts of accelerator and 3 parts of sulfur); and 8 parts of metal powder (iron powder with a particle size of 1 μm and a D50).

[0082] The preparation method of Example 6 is the same as that of Example 4.

[0083] Comparative Example 2

[0084] Comparative Example 2 provides a rubber composition for the lower triangular rubber 200 of the tire bead in the tire support section. The preparation method is the same as that in Example 4, except that no metal powder is added to the components.

[0085] The bead corner rubber compositions obtained in Examples 4-6 were compared with those in Comparative Example 2 in terms of thermal conductivity and hardness. The results are shown in Table 2.

[0086] Tire bead (lower triangular corner rubber) Comparative Example 2 Example 4 Example 5 Example 6 Iron powder (parts) 0 4 6 8 Iron powder particle size D50 (μm) 0 1 1 1 Thermal conductivity (W / m·℃) 0.3 0.34 0.38 0.41 Hardness (Shore hardness 0-100) 90 91 91 91

[0087] Table 2

[0088] As can be seen from the data in Table 2, the hardness in Comparative Example 2 is Shore hardness 90, and in Examples 4 to 6, the hardness is Shore hardness 91 after the iron powder content is increased.

[0089] Increasing the hardness appropriately helps improve the structural stability of the triangular rubber under the rubber ring, allowing it to better maintain its shape and reduce deformation under the pressure, friction and other external forces during vehicle operation, thereby ensuring the overall structural stability of the tire and improving tire safety.

[0090] Example 7

[0091] This embodiment 7 provides a tire support shoulder rubber composition, which is used as the rubber at the pad 300, and is composed of the following components by weight: 100 parts of rubber matrix; 35 parts of carbon black; 8 parts of activator (7 parts of zinc oxide and 1 part of stearic acid); 3.5 parts of vulcanizing agent (2.5 parts of accelerator and 1 part of sulfur); and 1 part of metal powder (iron powder with a particle size of 1 μm and a D50).

[0092] The preparation method of this embodiment includes: adding rubber compound to a mixer, closing the mixer, and starting pressure to obtain pressurized rubber; the pressure is 14 MPa, and the pressurization time is 65 s. Raising the pressure bar and adding carbon black to the pressurized rubber; stirring for 14 min, then sequentially adding an activator, metal powder, and vulcanizing agent, and continuing to mix for 34 min to obtain a compound; the mixing speed is 34 r / min, and the mixing temperature is 120℃. After stirring the compound for 1.4 min, the rubber is discharged to obtain a tire shoulder rubber composition.

[0093] Example 8

[0094] This embodiment 8 provides a tire support shoulder rubber composition, which is used as the rubber at the pad 300, and is composed of the following components by weight: 100 parts of rubber matrix; 40 parts of carbon black; 8 parts of activator (6 parts of zinc oxide and 2 parts of stearic acid); 3.5 parts of vulcanizing agent (2.5 parts of accelerator and 1 part of sulfur); and 2 parts of metal powder (iron powder with a particle size of 1 μm and a D50).

[0095] The preparation method of Example 8 is the same as that of Example 7.

[0096] Example 9

[0097] This embodiment 9 provides a tire support shoulder rubber composition, which is used as the rubber at the pad 300, and is composed of the following components by weight: 100 parts of rubber matrix; 45 parts of carbon black; 8 parts of activator (5 parts of zinc oxide and 3 parts of stearic acid); 3.5 parts of vulcanizing agent (2.5 parts of accelerator and 1 part of sulfur); and 3 parts of metal powder (iron powder with a particle size of 1 μm and a D50).

[0098] The preparation method of Example 9 is the same as that of Example 7.

[0099] Comparative Example 3

[0100] Comparative Example 3 provides a rubber composition for tire shoulder pad adhesive 300 in tire support section, which is prepared in the same way as in Example 7, except that no metal powder is added to the components.

[0101] The tire shoulder pad rubber compositions obtained in Examples 7-9 were compared with those in Comparative Example 3 in terms of thermal conductivity, thermal diffusivity, fatigue life, and hardness. The results are shown in Table 3.

[0102] Tire shoulder (pad) Comparative Example 3 Example 7 Example 8 Example 9 Iron powder (parts) 0 1 2 3 Iron powder particle size D50 (μm) 0 1 1 1 Thermal conductivity (W / m·℃) 0.24 0.25 0.27 0.29 thermal diffusivity 0.2 0.22 0.24 0.25 Fatigue life <![CDATA[1.01×10 7 ]]> <![CDATA[1.21×10 7 ]]> <![CDATA[1.05×10 7 ]]> <![CDATA[2.25×10 7 ]]> Hardness (Shore hardness 0-100) 63 64 65 64

[0103] Table 3

[0104] As can be seen from the data in Table 3, the addition of iron powder increased the thermal diffusivity of Examples 7-9, and its application in tire pad rubber can dissipate heat more quickly.

[0105] The fatigue life increased significantly after the addition of iron powder, with Comparative Example 3 showing an increase of 1.01 × 10⁻⁶. 7 Example 9 achieved 2.25×10, indicating that adding iron powder can significantly improve the fatigue resistance of the tire shoulder pad rubber, with Example 9, which has the highest iron powder content, showing the best effect.

[0106] The hardness increased to a certain extent after adding iron powder, from a maximum of 63 to 65, indicating that the amount of iron powder added can improve the hardness of the padding.

[0107] Finally, it should be noted that the specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, 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 rubber composition for a tire support portion, characterized in that, It consists of the following components in parts by weight: 100 parts rubber compound; 35-65 parts carbon black; 5-8 parts activator; 3-6 parts vulcanizing agent; 1-8 parts metal powder; The metal powder is iron powder, and the particle size D50 of the iron powder is 0.5μm to 1μm; The activator includes zinc oxide and stearic acid; the zinc oxide is 2 to 7 parts and the stearic acid is 1 to 3 parts. The vulcanizing agent includes an accelerator and sulfur; the accelerator is 0.8 to 3 parts, and the sulfur is 2.2 to 5.2 parts.

2. The tire support rubber composition according to claim 1, characterized in that, The rubber compound includes at least one of natural rubber and butadiene rubber.

3. The tire support rubber composition according to claim 1, characterized in that, The accelerator includes at least one of sulfenamides, thiazoles, thiurams, thioureas, dithiocarbamates, aldehydes, guanidines, or xanthates.

4. A method for preparing a tire support rubber composition, used to prepare the tire support rubber composition according to any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: Add 100 parts of the rubber compound to the internal mixer, turn off the internal mixer, start pressurizing, and obtain pressurized rubber; Step 2: Raise the pressure block and add 35-65 parts of the carbon black to the pressurized rubber; stir for 10-15 minutes, then add 5-8 parts of the activator, 1-8 parts of the metal powder and 3-6 parts of the vulcanizing agent in sequence, and continue to mix for 15-25 minutes to obtain the compound rubber. Step 3: Stir the rubber compound for 1 to 1.5 minutes and then discharge the rubber to obtain the tire support rubber composition.

5. The method for preparing the tire support rubber composition according to claim 4, characterized in that, In step 1, the pressure applied is 10MPa to 15MPa, and the pressurization time is 50s to 65s.

6. The method for preparing the tire support rubber composition according to claim 4, characterized in that, In step 2, the mixing speed is 30 r / min to 35 r / min, and the mixing temperature is 100℃ to 130℃.

7. A tire, characterized in that, It is prepared using the tire support rubber composition according to any one of claims 1 to 3.

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