Cut-resistant, low-heat-building all-steel engineering radial tire tread formulation and method of making

Abstract

This invention relates to a cut-resistant, low-heat-generating all-steel radial engineering tire tread compound formulation and its preparation method, comprising: 70-80 parts natural rubber, 30-50 parts styrene-butadiene rubber, 20-40 parts carbon black, 10-15 parts silica, 2-3 parts silane coupling agent, 2-3 parts stearic acid, 3-4.5 parts zinc oxide, 3-5 parts antioxidant system, 1-2 parts dispersant, 1-4 parts sulfur, 1-4 parts accelerator, and 0.1-0.4 parts scorching inhibitor; the raw rubber of this invention... The system primarily uses natural rubber, which is high in strength and low in heat generation. It also incorporates solution-polymerized styrene-butadiene rubber (SBR) to overcome the high heat generation disadvantage of traditional emulsion-polymerized SBR. Furthermore, it utilizes a wet mixing technique involving carbon nanotubes and nano-carbon black in solution-polymerized SBR to resolve dispersion issues related to reinforcing fillers and carbon nanotubes. This results in a high proportion of binder, high strength, low heat generation, and outstanding abrasion resistance. Simultaneously, it also gives the formulation excellent cut and puncture resistance, effectively overcoming the issues of prominent shoulder and crown aortic ...

Description

Technical Field

[0001] This invention relates to the field of tire technology, specifically to a cut-resistant, low-heat-generating all-steel engineering radial tire tread compound formulation and its preparation method. Background Technology

[0002] With the acceleration of global industrialization, the global production of off-highway radial tires has been rising steadily.

[0003] With changes in vehicle types and road conditions, bias-ply tires can no longer meet current usage requirements, leading to a complete replacement of off-road tires with all-steel radial tires in mines. Since 2022, my country's policies regarding mine road surfaces have been adjusted, with requirements such as longer transport distances and wider roads. This means more stringent durability requirements for all-steel engineering radial tires. Furthermore, as the mining market continues to expand and transport distances increase, vehicle performance is constantly improving, and vehicle types are gradually shifting towards larger sizes. Facing increasingly fierce market competition, transport vehicles are increasingly characterized by higher cargo boxes and stacked loading, placing higher demands on tire load capacity and performance.

[0004] Traditional cut-resistant and high-abrasion-resistant tread compounds mainly use a high proportion of styrene-butadiene rubber (SBR), modifying the reinforcing system, vulcanization system, or applying new materials such as tear-resistant resins. While these methods improve the tear and cut resistance of the compound, they also lead to other problems. The most obvious are: significantly increased tire heat generation, increased rolling resistance energy consumption, and premature tire damage caused by heat-induced defects such as shoulder gaps, bead gaps, and crown gaps.

[0005] Patent application 202111632012.2 discloses a cut-resistant and chip-resistant all-steel engineering radial tire tread compound and its preparation method. It is composed of the following raw materials in parts by weight: natural rubber: 20-30 parts, styrene-butadiene rubber: 70-80 parts, carbon black: 55-60 parts, silica: 5-15 parts, stearic acid: 1-3 parts, zinc oxide: 3-5 parts, anti-aging system: 5-6 parts, resin: 2-4 parts, oil: 3-6 parts, vulcanization accelerator: 2-4 parts. The aforementioned formulation uses 70-80 parts of a relatively high proportion of traditional latex styrene-butadiene rubber (SBR1500E), with a styrene monomer content of 23.5%. It primarily utilizes the rigid segments of styrene to enhance the formulation's resistance to cuts and abrasion on harsh road surfaces. However, since synthetic rubber is weaker than natural rubber, the high SBR proportion directly results in lower tensile strength and higher heat generation. In actual use, tires exhibit numerous shoulder defects due to high heat generation. Furthermore, the formulation uses a large amount of resin and processing oil, further reducing its strength; its tensile strength only reaches approximately 19-20 MPa. While maintaining the original cut resistance and chipping resistance, the current trend of longer transport distances and wider roads in mining environments, coupled with increased tire load requirements, no longer meets the demands for high strength and low heat generation in these new environments.

[0006] Therefore, in order to meet current market demands, it is imperative to develop a tread compound for all-steel engineering radial tires that is cut-resistant, highly wear-resistant, low-heat-generating, and high-strength to adapt to current road conditions in mining areas. Summary of the Invention

[0007] In view of at least one of the defects of existing all-steel engineering radial tire tread rubbers, namely significantly increased heat generation, increased rolling resistance and energy consumption, leading to premature damage caused by heat-induced defects such as shoulder gaps, bead gaps, and crown gaps, this invention provides a cut-resistant, low-heat-generating all-steel engineering radial tire tread rubber formulation.

[0008] The objective of this invention can be achieved through the following technical solutions: One of the objectives of this invention is to provide a cut-resistant, low-heat-generating all-steel engineering radial tire tread compound formulation, which, by weight, comprises the following components: 70-80 parts natural rubber, 30-50 parts styrene-butadiene rubber, 20-40 parts carbon black, 10-15 parts silica, 2-3 parts silane coupling agent, 2-3 parts stearic acid, 3-4.5 parts zinc oxide, 3-5 parts antioxidant system, 1-2 parts dispersant, 1-4 parts sulfur, 1-4 parts accelerator, and 0.1-0.4 parts scorching inhibitor; The anti-aging system includes a protective wax, a first anti-aging agent, and a second anti-aging agent in a mass ratio of (1~2): (1~1.5): (1.5~3).

[0009] Furthermore, the natural rubber is TSR9710+, with the following performance requirements: initial plasticity P0≥40, plasticity retention PRI≥67, tensile strength≥24MPa, and elongation at break≥660%.

[0010] Furthermore, the styrene-butadiene rubber mentioned is a wet-process solution-polymerized styrene-butadiene composite rubber, whose composition includes the following components in parts by weight: 50-70 parts of solution-polymerized styrene-butadiene rubber SSBR2361F, 2-4 parts of carbon nanotubes, and 28-46 parts of nano-carbon black. By applying carbon nanotubes (CNTs) in the formulation of off-highway radial tires, the strength and thermal conductivity of some formulations are improved. CNTs possess excellent mechanical properties, with tensile strength reaching 50-200 GPa, exhibiting high modulus and high strength. Research on the application and mixing of CNTs in the formulation enhances the tensile strength and abrasion resistance of the formulation. It also balances the stress at a given elongation, improving the compound's resistance to shavings. Simultaneously, the low heat generation improves the overall performance of the tire.

[0011] Furthermore, the carbon black is N115 carbon black, with a DBP oil absorption value of (107-119)×10. -5 m 3 / kg, iodine absorption value (153-167) g / Kg, tinting strength 119-131. Traditional all-steel radial engineering tire tread compound formulations mainly use N234 carbon black, which is a medium-to-super wear-resistant carbon black with high structure and good wear resistance, but its heat generation is relatively high. This invention utilizes N115 carbon black, taking advantage of its high specific surface area, high wear resistance, high elongation, and high strength, to improve the wear resistance and tear resistance of the formulation. It also reduces the heat generation of the rubber compound and extends the service life of the finished tire.

[0012] Furthermore, the protective wax is protective wax RW221; the first antioxidant is antioxidant RD; and the second antioxidant is antioxidant 4020.

[0013] Furthermore, the silane coupling agent is silane coupling agent SI-69, which is a 1:1 mixture of bis-[γ-(triethoxysilane)propyl]tetrasulfide and N330 carbon black.

[0014] Furthermore, the stearic acid is stearic acid type 200, with an iodine value ≤0.5 g / 100g, a saponification value of (206-212) mg KOH / g, an acid value of (205-211) mg KOH / g, and a C18 content of (39-44)%.

[0015] Furthermore, the dispersant is a zinc soap of higher fatty acids.

[0016] Furthermore, the accelerator is accelerator CZ.

[0017] The second objective of this invention is to provide a method for preparing a cut-resistant, low-heat-generating all-steel engineering radial tire tread compound, which uses the tread compound formulation described above and includes the following steps: S1: Put natural rubber into an internal mixer and mix for 40-60 seconds. Raise the top bolt and hold for 10-15 seconds. Press down the top bolt again and continue mixing until the rubber temperature is 160℃-170℃. Discharge the rubber to obtain plasticized rubber. Let the obtained plasticized rubber stand at room temperature for at least 2 hours. S2: Set the initial speed of the internal mixer to 60-90 rpm, put the plasticized rubber and styrene-butadiene rubber obtained in step S1 into the internal mixer and premix for 30-60 seconds, then add carbon black, zinc oxide, stearic acid, protective wax, antioxidant and dispersant for mixing; when the rubber temperature rises to 120-140℃, raise the top bolt, hold for 10-20 seconds, then reduce the speed of the internal mixer to 15-25 rpm, press down the top bolt and continue mixing until the rubber temperature is 155℃-160℃, then discharge the rubber to obtain a first-stage masterbatch, and let the obtained first-stage masterbatch stand at room temperature for at least 8 hours; S3: Set the initial speed of the internal mixer to 45~55 rpm, put the first stage of masterbatch obtained in step S2 into the internal mixer, add silica and silane coupling agent for mixing, the mixing time is 110~120 seconds, the discharge temperature is 148℃~155℃, and the second stage of masterbatch is obtained. Let the obtained second stage of masterbatch stand at room temperature for at least 8 hours. S4: Set the initial speed of the internal mixer to 60~90 rpm, and put the second-stage masterbatch, sulfur, accelerator and anti-scorching agent obtained in step S3 into the internal mixer for mixing. The mixing time is 150~160 seconds and the discharge temperature is 110℃~115℃ to obtain the cut-resistant, low-heat-generating all-steel engineering radial tire tread rubber.

[0018] Compared with the prior art, the present invention has the following advantages: (1) Natural rubber has high strength, low hysteresis loss, and lower heat generation than styrene-butadiene rubber. It can be processed by simply plasticizing and has good affinity with carbon black. Styrene-butadiene rubber has rigid styrene segments, making it wear-resistant and cut-resistant. It generates a lot of heat and has lower strength than natural rubber. In the existing technology, for the tread formulation of all-steel engineering radial tires that are cut-resistant and anti-scratching, styrene-butadiene rubber is used or styrene-butadiene rubber is used as the main component and natural rubber is used. The proportion of styrene-butadiene rubber in the formulation is relatively high, which improves the cut resistance and anti-scratching performance. However, the content of rigid benzene ring groups in the formulation increases, the heat generation of the formulation is higher, and the styrene-butadiene rubber content is high. In order to improve the processing performance, resin, processing oil and other softeners need to be added, which further reduces the strength of the formulation. This results in high heat generation and low strength of the tire, which cannot meet the current market demand. The finished tire feedback shows prominent shoulder gap and crown gap.

[0019] In this invention, the raw rubber system is primarily composed of natural rubber, which boasts high strength and low heat generation. Solution-polymerized styrene-butadiene rubber (SBR) is used to overcome the high heat generation drawback of traditional emulsion-polymerized SBR. Furthermore, the wet mixing technology of carbon nanotubes and nano-carbon black in solution-polymerized SBR solves the dispersion problems of reinforcing fillers and carbon nanotubes. This results in a high proportion of binder, high strength, low heat generation, and outstanding abrasion resistance. Simultaneously, the formulation also exhibits excellent cut and puncture resistance. Therefore, it effectively overcomes the problems of shoulder and coronal aneurysms reported in the current market.

[0020] 2. In this invention, N115 carbon black is used instead of N234 carbon black in the prior art. Its high specific surface area improves the wear resistance of the formulation while reducing heat generation. Simultaneously, the formulation uses high-grade unsaturated fatty acid zinc soap dispersants to reduce the intermolecular forces in rubber, improve the dispersion of the carbon black reinforcing filler, and further enhance heat generation and wear resistance. This increases tire lifespan.

[0021] 3. In this invention, natural rubber is plasticized so that its Mooney viscosity is close to that of styrene-butadiene rubber (SBR), thereby enabling better blending of natural rubber and SBR and avoiding uneven dispersion of carbon black in natural rubber and SBR due to large Mooney viscosity deviation. Detailed Implementation

[0022] The present invention will now be described in detail with reference to specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0023] Unless otherwise specified, the raw materials used in the following examples and comparative examples are all commercially available products, such as: Natural rubber, purchased from Xishuangbanna Manlie Rubber Co., Ltd., model number TSR9710+.

[0024] The carbon black was purchased from Xinjiang Junxin Chemical Co., Ltd., and its model is N115 carbon black.

[0025] The silica was purchased from Wuxi Hengcheng Silicon Industry Co., Ltd., model number HCSIL-900MP.

[0026] The silane coupling agent is silane coupling agent SI-69, which is a 1:1 mixture of bis-[γ-(triethoxysilane)propyl]tetrasulfide and N330 carbon black.

[0027] Stearic acid is stearic acid type 200, with an iodine value ≤0.5 g / 100g, a saponification value of (206-212) mg KOH / g, an acid value of (205-211) mg KOH / g, and a C18 content of (39-44)%.

[0028] Protective wax, purchased from Jiangsu Ruiba New Material Technology Co., Ltd., model: RW221.

[0029] Antioxidant RD, purchased from Shandong Shangshun Chemical Holding Co., Ltd., model: TMQ.

[0030] Antioxidant 4020, purchased from Shandong Shangshun Chemical Holding Co., Ltd., model: 6PPD.

[0031] The dispersant was purchased from Fuyang Hongyuan Rubber Technology Co., Ltd., model: HY-1001.

[0032] Accelerator, purchased from Shandong Shangshun Chemical Holding Co., Ltd., model: S200 mesh, accelerator CZ.

[0033] The anti-scorching agent was purchased from Shandong Yanggu Huatai Chemical Co., Ltd., model: PVI.

[0034] The wet-solution polymerized styrene-butadiene rubber (SBR) comprises the following components in parts by weight: 50-70 parts of solution-polymerized SBR SSBR2361F, 2-4 parts of carbon nanotubes, and 28-46 parts of nano-carbon black. The preparation method of the wet-solution polymerized SBR includes the following steps: (1) Surface modification of carbon nanotubes: Three parts of carbon nanotubes were added to a 10wt% dilute nitric acid aqueous solution, and the mass ratio of carbon nanotubes to acid was controlled to be approximately 1:20. The mixture was magnetically stirred at 60℃ for 2 hours to introduce a small amount of functional groups such as -COOH and -OH onto the surface of the carbon nanotubes. After the reaction, the mixture was repeatedly washed with deionized water until the pH of the washing solution was close to neutral. The solution was then filtered and vacuum dried at 80℃ for later use. The dried carbon nanotubes were dispersed in a Tris buffer solution (pH 8.0-8.5), and 0.24 parts of dopamine were added. The mixture was ultrasonically dispersed for 30 minutes and then mechanically stirred at room temperature (20-25℃) for 12-24 hours to allow dopamine to self-polymerize on the surface of the carbon nanotubes to form a polydopamine coating layer. After the reaction, the liquid phase was removed by filtration, and the mixture was washed with deionized water until the washing solution was colorless and transparent. The mixture was then vacuum dried at 80℃ to obtain polydopamine-modified carbon nanotubes.

[0035] (2) Wet modification of nano-carbon black: 35 parts of nano-carbon black were added to n-heptane, and the solid content of the system was adjusted to 10-15 wt%. The mixture was sheared in a high-speed shear disperser at 2000-4000 rpm for 15-30 min to obtain a uniform carbon black slurry. 1.05 parts of silane coupling agent SI69 were added to the carbon black slurry, and the mixture was stirred and reacted at 60-80℃ for 30-60 min to allow Si-69 to condense or adsorb onto the active sites on the carbon black surface, thus obtaining a SI69-modified nano-carbon black dispersion.

[0036] (3) Preparation of solution-polymerized styrene-butadiene rubber solution: Cut 100 parts of solution-polymerized styrene-butadiene rubber SSBR2361F dry rubber into small pieces, add to 350 parts of n-heptane, control the temperature at 30-40℃, stir at 100-200 rpm for 2-3 hours until the solution-polymerized styrene-butadiene rubber SSBR2361F is completely dissolved, and obtain solution-polymerized styrene-butadiene rubber solution.

[0037] (4) Wet blending of carbon nanotubes / nano-carbon black with solution-polymerized styrene-butadiene rubber (SBR): The SBR obtained in step (3) is transferred to a jacketed blending vessel, and the temperature is adjusted to 30-35°C. Under a stirring speed of 200-400 rpm, polydopamine-modified carbon nanotube dispersion is slowly added dropwise over a time of 30-60 min. After the addition is complete, stirring continues for 30-60 min to allow the carbon nanotubes to form a stable nanoscale dispersion in the SBR and be fully coated by the SBR molecular chains, thus obtaining a carbon nanotube / solution-polymerized SBR pre-composite solution. The Si-69-modified nano-carbon black dispersion obtained in step 2 is added to the carbon nanotube / solution-polymerized SBR pre-composite solution in 2-3 batches, with stirring at 300-600 rpm for 10-20 min after each addition. During the blending process, the system temperature is maintained at 30–40°C, and the total blending time is approximately 60 minutes, until a uniform CNTs / nanocarbon black / SSBR ternary composite solution with no obvious sedimentation or agglomeration is obtained. The composite solution is continuously fed into a coagulation tower or a stirred coagulation vessel, and saturated steam is introduced from the bottom of the tower, with the steam pressure controlled at 0.3–0.6 MPa. An azeotrope is formed between n-heptane and water, and the solvent is stripped along with the steam and condensed and recovered at the top of the tower. As the solvent concentration decreases, SSBR carrying CNTs and nanocarbon black precipitates from the solution, forming rubber / filler co-precipitated wet particles with a predominantly 0.5–3 mm particle size, uniformly dispersed in the aqueous phase. The co-precipitated wet particles are separated from most of the water using a hydrocyclone, vibrating screen, or similar equipment to obtain wet masterbatch particles with a moisture content of approximately 30%–50%. The wet masterbatch granules are fed into a horizontal screw centrifuge and centrifuged at 1500–3000 rpm for 5–15 minutes to reduce the moisture content of the granules to no more than 15%. The dehydrated wet masterbatch granules are then fed into a vibrating fluidized bed dryer and dried with hot air at 80–100°C, with the outlet air temperature controlled at 60–70°C for 40–60 minutes, to reduce the moisture content of the rubber masterbatch to below 0.5 wt% and the residual n-heptane content to no more than 0.5 wt%, thus obtaining wet-process solution-polymerized styrene-butadiene composite rubber.

[0038] Example 1 This embodiment provides a cut-resistant, low-heat-generating all-steel engineering radial tire tread compound, prepared with the following raw materials in parts by weight: 70 parts natural rubber, 50 parts wet-process solution-polymerized styrene-butadiene rubber, 28 parts N115 carbon black, 15 parts silica, 3 parts silane coupling agent SI69, 2 parts stearic acid, 3.5 parts zinc oxide, 2.5 parts antioxidant 4020, 1 part antioxidant RD, 1 part protective wax, 1 part dispersant, 1 part sulfur, 1.5 parts accelerator CZ, and 0.2 parts anti-scorching agent.

[0039] The preparation method of the tread compound for this all-steel engineering radial tire is as follows: (1) Put natural rubber into a BB430 internal mixer (rotor model 6WI) and mix for 30-40 seconds. Then raise the top bolt and hold for 10-20 seconds. Then press the bolt until the temperature is 160℃-170℃ and discharge the rubber to obtain plasticized rubber. Let the plasticized rubber stand at room temperature for at least 2 hours.

[0040] (2) Set the initial speed of the F370 internal mixer (rotor model 4WH) to 60 rpm. Put the plasticized rubber and wet solution polymerized styrene-butadiene composite rubber obtained in step (1) into the F370 internal mixer for premixing for 30 seconds. Then add N115 carbon black, zinc oxide, stearic acid, anti-aging system and dispersant to the F370 internal mixer for mixing. Raise the temperature to 140℃ and raise the top bolt. Hold the top bolt for 20 seconds and reduce the speed to 25 rpm. Press the top bolt until the discharge temperature is 155℃-160℃ to discharge the rubber and obtain a section of masterbatch. The mixing time is 150-160 seconds. Let the section of masterbatch stand for at least 8 hours.

[0041] (3) Set the initial speed of the F370 internal mixer (rotor model 4WH) to 55 rpm. Put the first stage of masterbatch obtained in step (2) into the F370 internal mixer, add silica and silane coupling agent SI69 for mixing. The mixing time is 110-120 seconds and the discharge temperature is 148℃-155℃ to obtain the second stage of masterbatch. Let the second stage of masterbatch stand for at least 8 hours.

[0042] (4) Set the initial speed of the BB430 internal mixer (rotor model 4WN) to 60 rpm. Add the second-stage masterbatch, sulfur, accelerator, and anti-scorching agent obtained in step (3) into the BB430 internal mixer for mixing. The mixing time is 150-160 seconds, and the discharge temperature is 110-115℃ to obtain the all-steel engineering radial tire tread compound. Let the all-steel engineering radial tire tread compound stand at room temperature for at least 8 hours.

[0043] (5) The product obtained in sampling step (4) is used to prepare vulcanized test pieces by cutting the product from the open mill: vulcanization is carried out using a flat vulcanizing machine, vulcanization temperature: 145℃, vulcanization time: 40min, vulcanization pressure: 30MPa, and the performance of the vulcanized product is shown in Table 1.

[0044] Example 2 This embodiment provides a cut-resistant, low-heat-generating all-steel radial engineering tire tread compound. The raw materials are prepared in the following weight proportions: 80 parts natural rubber, 35 parts wet-process solution-polymerized styrene-butadiene rubber, 35 parts N115 carbon black, 10 parts silica, 2 parts silane coupling agent SI69, 2 parts stearic acid, 3.5 parts zinc oxide, 2.5 parts antioxidant 4020, 1 part antioxidant RD, 1 part protective wax, 1 part dispersant, 1 part sulfur, 1.5 parts accelerator CZ, and 0.2 parts anti-scorching agent.

[0045] The preparation method of the tread compound for this all-steel engineering radial tire is as follows: (1) Put natural rubber into a BB430 internal mixer (rotor model 6WI) and mix for 30-40 seconds. Then raise the top bolt and hold for 10-20 seconds. Then press the bolt until the temperature is 160℃-170℃ and discharge the rubber to obtain plasticized rubber. Let the plasticized rubber stand at room temperature for at least 2 hours.

[0046] (2) Set the initial speed of the F370 internal mixer (rotor model 4WH) to 60 rpm. Put the plasticized rubber and wet solution polymerized styrene-butadiene composite rubber obtained in step (1) into the F370 internal mixer for premixing for 30 seconds. Then add N115 carbon black, zinc oxide, stearic acid, anti-aging system and dispersant into the F370 internal mixer for mixing. Raise the temperature to 140℃ and raise the top bolt. Hold the top bolt for 20 seconds and reduce the speed to 25 rpm. Press the top bolt until the discharge temperature is 155℃-160℃ to discharge the rubber and obtain a section of masterbatch. The mixing time is 150-160 seconds. Let the section of masterbatch stand for at least 8 hours.

[0047] (3) Set the F370 internal mixer (rotor model 4WH) to 55 rpm, put the first stage of masterbatch obtained in step (2) into the F370 internal mixer, add silica and silane coupling agent SI69 for mixing, the mixing time is 110-120 seconds, the discharge temperature is 148-155℃ to obtain the second stage of masterbatch, and let the second stage of masterbatch stand for at least 8 hours.

[0048] (4) Set the initial speed of the BB430 internal mixer (rotor model 4WN) to 60~90 rpm. Add the second-stage masterbatch, sulfur, accelerator, and anti-scorching agent obtained in step (3) into the BB430 internal mixer for mixing. The mixing time is 150-160 seconds, and the discharge temperature is 110-115℃ to obtain the all-steel engineering radial tire tread compound. Let the all-steel engineering radial tire tread compound stand at room temperature for at least 8 hours.

[0049] (5) The product obtained in sampling step (4) is used to prepare vulcanized test pieces by cutting the product from the open mill: vulcanization is carried out using a flat vulcanizing machine, vulcanization temperature: 145℃, vulcanization time: 40min, vulcanization pressure: 30MPa, and the performance of the vulcanized product is shown in Table 1.

[0050] Comparative Example 1 This comparative example is basically the same as Example 1, except that the formulation in this comparative example is as follows: 70 parts natural rubber, 30 parts latex styrene-butadiene rubber SBR1500E, 55 parts N115 carbon black, 1 part carbon nanotubes, 2 parts stearic acid, 3.5 parts zinc oxide, 2.5 parts antioxidant 4020, 1 part antioxidant RD, 1 part protective wax, 1 part dispersant, 1 part sulfur, 1.5 parts accelerator CZ, and 0.2 parts anti-scorching agent.

[0051] Comparative Example 2 This comparative example is basically the same as Example 1, except that the formulation in this comparative example is as follows: 20 parts natural rubber, 80 parts styrene-butadiene rubber SBR1500E, 30 parts N234 carbon black, 30 parts N326 carbon black, 15 parts silica, 1 part stearic acid, 3 parts zinc oxide, 2 parts antioxidant RD, 2 parts antioxidant 4020, 1 part protective wax, 1 part 203 resin, 1 part dispersant, 3 parts naphthenic oil, 1 part sulfur, and 2 parts accelerator CZ.

[0052] Examples 1-2 and Comparative Examples 1-2 were vulcanized under the same conditions and their physical properties were tested. The results are shown in the table below: As can be seen from Examples 1 and 2 above, with the increase of wet-solution polymerized styrene-butadiene rubber (SBR), the elongation and strength of the formulation show a decreasing trend, while the DIN abrasion and cutting resistance decrease. In Comparative Example 1, the ratio of natural rubber to emulsion SBR is 70 / 30, and other formulations are basically the same. Comparing Example 1 using wet-solution polymerized SBR with Comparative Example 1 using emulsion SBR1500E, it can be seen that the formulation using wet-solution polymerized SBR has a strength that is nearly 15% higher than that using emulsion SBR, a reduction in compression heat generation of about 20%, and an improvement in cutting resistance of nearly 12.7%.

[0053] In Comparative Example 2, the ratio of natural rubber to styrene-butadiene rubber was 20 / 80. Compared with Example 2, where the ratio of natural rubber to wet-process solution-polymerized styrene-butadiene rubber was 80 / 35, Comparative Example 2 had a higher styrene-butadiene rubber content, a lower formulation strength by 25.7%, and a higher compression heat generation by 39.6%. This resulted in insufficient load-bearing capacity of the finished tires, higher tread heat generation, and the presence of crown and shoulder voids in the finished tires.

[0054] As can be seen from the table above, by adjusting the appropriate ratio of natural rubber to styrene-butadiene rubber and using wet-process solution-polymerized styrene-butadiene rubber to replace emulsion-polymerized styrene-butadiene rubber SBR1500E, the heat generation of the formulation is significantly reduced and the strength is improved. The formulation maintains appropriate elongation and elongation, while exhibiting excellent cut resistance and abrasion resistance, and significantly reduced heat generation. This effectively overcomes the prominent problems of poor load-bearing capacity, shoulder voids, and crown voids reported by the market.

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A cut-resistant, low-heat-generating all-steel engineering radial tire tread compound formulation, characterized in that, By weight, it comprises the following components: 70-80 parts natural rubber, 30-50 parts styrene-butadiene rubber, 20-40 parts carbon black, 10-15 parts silica, 2-3 parts silane coupling agent, 2-3 parts stearic acid, 3-4.5 parts zinc oxide, 3-5 parts antioxidant system, 1-2 parts dispersant, 1-4 parts sulfur, 1-4 parts accelerator, and 0.1-0.4 parts scorching inhibitor; The anti-aging system includes a protective wax, a first anti-aging agent, and a second anti-aging agent in a mass ratio of (1~2): (1~1.5): (1.5~3).

2. The tread compound formulation for a cut-resistant, low-heat-generating all-steel engineering radial tire according to claim 1, characterized in that, The natural rubber is TSR9710+, with the following performance requirements: initial plasticity P0≥40, plasticity retention PRI≥67, tensile strength≥24MPa, and elongation at break≥660%.

3. The tread compound formulation for a cut-resistant, low-heat-generating all-steel engineering radial tire according to claim 1, characterized in that, The styrene-butadiene rubber mentioned is a wet-process solution-polymerized styrene-butadiene composite rubber, which comprises the following components in parts by weight: 50-70 parts of solution-polymerized styrene-butadiene rubber SSBR2361F, 2-4 parts of carbon nanotubes, and 28-46 parts of nano carbon black.

4. The tread compound formulation for a cut-resistant, low-heat-generating all-steel engineering radial tire according to claim 1, characterized in that, The carbon black is N115 carbon black, DBP oil absorption value is (107-119) x 10 -5 m 3 / kg, iodine absorption value is (153-167) g / Kg, color strength is 119-131.

5. The tread compound formulation for a cut-resistant, low-heat-generating all-steel engineering radial tire according to claim 1, characterized in that, The protective wax is protective wax RW221; the first antioxidant is antioxidant RD; the second antioxidant is antioxidant 4020.

6. The tread compound formulation for a cut-resistant, low-heat-generating all-steel engineering radial tire according to claim 1, characterized in that, The silane coupling agent is silane coupling agent SI-69.

7. The tread compound formulation for a cut-resistant, low-heat-generating all-steel engineering radial tire according to claim 1, characterized in that, The stearic acid mentioned is stearic acid type 200, with an iodine value ≤0.5 g / 100g, a saponification value of (206-212) mg KOH / g, an acid value of (205-211) mg KOH / g, and a C18 content of (39-44)%.

8. The tread compound formulation for a cut-resistant, low-heat-generating all-steel engineering radial tire according to claim 1, characterized in that, The dispersant is a high-grade fatty acid zinc soap dispersant.

9. The tread compound formulation for a cut-resistant, low-heat-generating all-steel engineering radial tire according to claim 1, characterized in that, The accelerator is accelerator CZ.

10. A method for preparing a cut-resistant, low-heat-generating all-steel engineering radial tire tread compound, characterized in that, It adopts the tread compound formulation as described in any one of claims 1-9, and includes the following steps: S1: Put natural rubber into an internal mixer and mix for 40-60 seconds. Raise the top bolt and hold for 10-15 seconds. Press down the top bolt again and continue mixing until the rubber temperature is 160℃-170℃. Discharge the rubber to obtain plasticized rubber. Let the obtained plasticized rubber stand at room temperature for at least 2 hours. S2: Set the initial speed of the internal mixer to 60-90 rpm, put the plasticized rubber and styrene-butadiene rubber obtained in step S1 into the internal mixer and premix for 30-60 seconds, then add carbon black, zinc oxide, stearic acid, protective wax, antioxidant and dispersant for mixing; when the rubber temperature rises to 120-140℃, raise the top bolt, hold for 10-20 seconds, then reduce the speed of the internal mixer to 15-25 rpm, press down the top bolt and continue mixing until the rubber temperature is 155℃-160℃, then discharge the rubber to obtain a first-stage masterbatch, and let the obtained first-stage masterbatch stand at room temperature for at least 8 hours; S3: Set the initial speed of the internal mixer to 45~55 rpm, put the first stage of masterbatch obtained in step S2 into the internal mixer, add silica and silane coupling agent for mixing, the mixing time is 110~120 seconds, the discharge temperature is 148℃~155℃, and the second stage of masterbatch is obtained. Let the obtained second stage of masterbatch stand at room temperature for at least 8 hours. S4: Set the initial speed of the internal mixer to 60~90 rpm, and put the second-stage masterbatch, sulfur, accelerator and anti-scorching agent obtained in step S3 into the internal mixer for mixing. The mixing time is 150~160 seconds and the discharge temperature is 110℃~115℃ to obtain a cut-resistant, low-heat-generating all-steel engineering radial tire tread compound.

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