Kart tire tread rubber and preparation method thereof

Abstract

The invention discloses kart tire tread rubber and a preparation method thereof, and belongs to the technical field of automobile tire rubber materials. The kart tire tread rubber is prepared from the following raw materials: 40 phr to 60 phr of emulsion polymerized styrene-butadiene rubber, 40 phr to 60 phr of high-vinyl high-styrene solution polymerized styrene-butadiene rubber, 15 phr to 25 phr of liquid reinforcing resin, 90 phr to 120 phr of reinforcing carbon black, 2 phr to 5 phr of zinc oxide, 3 phr to 5 phr of an anti-aging agent, 1 phr to 2 phr of stearic acid, 2 phr to 5 phr of protective wax, 1 phr to 3 phr of sulfur masterbatch and 1 phr to 3 phr of accelerant CBS masterbatch. According to the invention, the emulsion polymerized styrene-butadiene rubber with high oil charge and the high-vinyl high-styrene solution polymerized styrene-butadiene rubber cooperate with each other, so that the basic grip potential of the tread rubber is improved from the rubber matrix layer; the special superfine-particle-size carbon black with high heat generation characteristic and the liquid reinforcing resin are adopted, the hot melting effect of the tread rubber is enhanced through the synergistic effect, and the road holding stability of the tread rubber under the high-temperature and high-speed working conditions is further guaranteed.

Description

Technical Field

[0001] This application belongs to the field of automotive tire rubber compound technology, specifically relating to a go-kart tire tread compound and its preparation method. Background Technology

[0002] As a type of motor vehicle that combines entertainment and competition, the performance of go-karts is directly related to the performance of their tire tread compound. Especially in track racing scenarios, the tread compound's grip, high-temperature stability, and heat-melting properties have a decisive impact on the vehicle's handling limits, safety performance, and racing results. Currently, most go-kart tire products on the market focus on basic usage needs for general recreational scenarios, with less attention paid to performance optimization for track racing, resulting in significant technical limitations in the design of existing tread compounds.

[0003] Existing go-kart tires commonly suffer from the following problems during track racing: (1) tire slippage is likely to occur when the vehicle accelerates, brakes or turns due to defects in the tread compound design; (2) the tires are prone to loss of grip and poor stability under long-term high temperature and high speed conditions.

[0004] In other words, existing go-kart tires, due to limitations in the selection of tread compound materials and formulation design, cannot meet the core requirements of high grip, anti-slip, and high-temperature and high-speed performance stability in track racing scenarios. Summary of the Invention

[0005] The purpose of this application is to provide a go-kart tire tread compound and its preparation method, which can solve the problem of go-kart tire slippage under track conditions and optimize the grip performance and stability of the tread compound.

[0006] To achieve the above objectives, this application provides a go-kart tire tread compound comprising the following raw materials: 40 phr to 60 phr of emulsion styrene-butadiene rubber, 40 phr to 60 phr of high-vinyl-high-styrene solution-polymerized styrene-butadiene rubber, 15 phr to 25 phr of liquid reinforcing resin, 90 phr to 120 phr of reinforcing carbon black, 2 phr to 5 phr of zinc oxide, 3 phr to 5 phr of antioxidant, 1 phr to 2 phr of stearic acid, 2 phr to 5 phr of protective wax, 1 phr to 3 phr of sulfur masterbatch particles, and 1 phr to 3 phr of accelerator CBS masterbatch particles.

[0007] Furthermore, it includes the following raw materials: 60 phr emulsion styrene-butadiene rubber, 40 phr high vinyl high styrene solution styrene-butadiene rubber, 20 phr liquid reinforcing resin, 110 phr reinforcing carbon black, 3 phr zinc oxide, 4.5 phr antioxidant, 1.5 phr stearic acid, 2 phr protective wax, 1.8 phr sulfur masterbatch, and 1.2 phr accelerator CBS masterbatch.

[0008] Furthermore, the latex styrene-butadiene rubber has a styrene content of 40% and a filler oil content of 50 phr.

[0009] Furthermore, the sulfur masterbatch particles have a sulfur content of 80 wt%, and the accelerator CBS masterbatch particles have a CBS content of 80 wt%.

[0010] Furthermore, the liquid reinforcing resin is an alkylphenol compound, obtained by decarboxylation distillation of shell oil.

[0011] Furthermore, the nitrogen adsorption specific surface area of ​​the reinforcing carbon black is 180 m². 2 / g~200m 2 / g, statistical thickness surface area is 150m² 2 / g~180m 2 / g.

[0012] Furthermore, the antioxidant includes an amine antioxidant, which includes at least one of antioxidant RD and / or antioxidant 4020, wherein the mass ratio of antioxidant RD to antioxidant 4020 is 2:1.

[0013] This application also provides a method for preparing go-kart tire tread compound, which uses a combination of a mixer and an extruder, and includes the following steps: Emulsion styrene-butadiene, high-vinyl-high-styrene solution styrene-butadiene, zinc oxide, antioxidant, protective wax, stearic acid, and reinforcing carbon black are fed into an internal mixer. The temperature of the internal mixer's discharge gate, mixing chamber, and rotor is controlled at 65°C to 75°C for the initial mixing. When the mixing temperature reaches the set value, liquid reinforcing resin is added for mixing. After reaching the set discharge temperature, the mixture is discharged to obtain a mixed rubber. The mixed rubber, sulfur masterbatch granules, and accelerator CBS masterbatch granules are fed into an extruder, mixed, and then extruded and mixed to obtain the final product.

[0014] Furthermore, the set value is 115℃~125℃, and the set unloading temperature is 140℃~150℃.

[0015] Furthermore, the mixing speed of the internal mixer is 45 rpm to 60 rpm, the initial mixing time is 15 s to 30 s, and the extrusion mixing time is 70 s to 90 s.

[0016] In summary, this application has the following advantages: The go-kart tire tread compound of this application adopts a compound system of emulsion styrene-butadiene rubber and high-vinyl-high-styrene solution styrene-butadiene rubber. The performance complementarity is achieved through the optimization of the ratio of the two rubbers: the high glass transition temperature of the high-vinyl-high-styrene solution styrene-butadiene rubber can significantly enhance the initial grip and cornering lateral grip of the tread compound on dry tracks, while the introduction of emulsion styrene-butadiene rubber ensures the basic wear resistance and elasticity of the tread compound; at the same time, liquid reinforcing resin and reinforcing carbon black form a synergistic reinforcing network. The resin can penetrate to the rubber-carbon black interface, improve the interfacial bonding force, and avoid the grip reduction caused by the slippage of carbon black aggregates at high temperatures. The carbon black dosage range achieves a balance between wear resistance requirements and elasticity retention. It strengthens the tread's resistance to deformation through high filling amount, while avoiding the problems of excessive filling leading to an overly hard tread and reduced grip contact area. Ultimately, the tread compound maintains stable grip in all scenarios such as low-speed start, medium-speed acceleration, and high-speed cornering, meeting the needs of go-karts for high-frequency changes of direction and short-distance racing. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart illustrating the preparation method of the go-kart tire tread compound involved in the embodiments of this application. Detailed Implementation

[0018] The principles and features of this application are described below with reference to embodiments. The examples are for illustrative purposes only and are not intended to limit the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0019] In track racing, existing go-kart tires generally face the following technical problems: (1) Insufficient grip leads to safety and performance hazards: Due to the defective formula design of existing tread rubber, tires are prone to slippage when the vehicle accelerates, brakes or turns. This may not only lead to safety risks such as crashes, but also limit the power output efficiency and control response speed of the go-kart, so that the vehicle's racing performance (such as acceleration ability and cornering limit) cannot be fully utilized; (2) Poor grip stability under high temperature and high speed conditions: In track racing, go-kart tires need to be in the harsh conditions of high temperature (tread temperature rise) and high speed (vehicle continuously drives at high speed) for a long time. Due to improper material selection, existing tread rubber is difficult to maintain stable grip under these conditions, and grip decay is prone to occur, further aggravating the risk of slippage. To address the aforementioned challenges of traditional tread compounds, this application develops a go-kart tire tread compound based on the synergistic effect between rubber matrix materials and additives. First, a synergistic combination of high-oil-filled emulsion styrene-butadiene rubber (ESBR) and high-vinyl, high-styrene solution-polymerized styrene-butadiene rubber (HBR) is employed to enhance the basic grip potential of the tread compound at the rubber matrix level. Second, a special ultrafine-particle carbon black with high heat generation properties and liquid reinforcing resin are rationally introduced, enhancing the tread compound's heat-melting effect through material synergy, further ensuring the stability of the tread compound's grip under high-temperature and high-speed conditions.

[0020] Based on this, in a first aspect, this application provides a go-kart tire tread compound comprising the following raw materials: 40 phr to 60 phr of emulsion styrene-butadiene rubber, 40 phr to 60 phr of high-vinyl-high-styrene solution styrene-butadiene rubber, 15 phr to 25 phr of liquid reinforcing resin, 90 phr to 120 phr of reinforcing carbon black, 2 phr to 5 phr of zinc oxide, 3 phr to 5 phr of antioxidant, 1 phr to 2 phr of stearic acid, 2 phr to 5 phr of protective wax, 1 phr to 3 phr of sulfur masterbatch particles, and 1 phr to 3 phr of accelerator CBS masterbatch particles.

[0021] Here, phr is an abbreviation for parts per hundred resin, meaning the number of parts added per 100 parts of raw rubber. It is an important unit of measurement for expressing the amount of additives in chemical formulations, specifically used for the formulation design and production control of polymer materials (such as plastics, rubber, coatings, etc.). Its core is to calculate the addition ratio of other components based on the "total mass of raw rubber" (set as 100 parts). For example, if the formulation indicates "stearic acid is 1 phr", it means that 1 part of stearic acid (1 phr of stearic acid) is required for every 100 parts of raw rubber (in this application, it refers to the sum of emulsion styrene-butadiene rubber and high vinyl high styrene solution styrene-butadiene rubber, for example, 50 phr of emulsion styrene-butadiene rubber plus 50 phr of high vinyl high styrene solution styrene-butadiene rubber).

[0022] In this application, (1) emulsion styrene-butadiene rubber is used as the base rubber, which has excellent wear resistance and processing fluidity, can reduce the process difficulty in mixing and vulcanization, and at the same time provide stable tread structure support, avoiding performance fluctuations caused by excessive tread deformation when go-karts start and stop frequently and turn sharply. (2) high vinyl high styrene solution styrene-butadiene rubber is used as the key functional rubber, whose high vinyl structure can significantly increase the glass transition temperature of rubber, enhance tread rigidity and dry grip at low temperatures (go-karts are mostly used on paved hard tracks, and dry grip directly affects cornering speed and acceleration response); the high styrene component further strengthens the tear resistance and compression set resistance of the tread, solving the problem of tread cracks and bulges that go-kart tires are prone to due to repeated lateral steering forces. (3) High-structure reinforcing carbon black is selected. Its high filling amount can maximize the tensile strength, tensile stress and wear index of the tread rubber, and significantly extend the service life of go-kart tires (ordinary go-kart tires need to be replaced frequently due to fast wear, but this formula can reduce the replacement frequency). After the carbon black is uniformly dispersed, it can form a rubber-carbon black network structure, which enhances the tread's resistance to deformation and avoids the loss of grip caused by excessive tread creep during high-speed cornering. (4) Liquid reinforcing resin is used as a synergistic reinforcing agent for carbon black. The liquid resin can penetrate between the rubber molecular chains and carbon black aggregates, further improving the interfacial bonding force and enhancing the tear resistance of the tread (especially for the problem of easy tearing at the edge of the go-kart tire tread); at the same time, it improves the dispersibility of carbon black in rubber, avoids the problem of uneven wear resistance and uneven vulcanization caused by carbon black agglomeration, and improves the overall performance stability of the tread. (5) Using sulfur masterbatch and accelerator CBS masterbatch as the vulcanization system, and antioxidant, protective wax, zinc oxide and stearic acid as the protective system, can ensure the stability and efficiency of mixing and vulcanization.

[0023] As an optional embodiment of this application, a go-kart tire tread compound comprises the following raw materials: 60 phr of emulsion styrene-butadiene rubber, 40 phr of high vinyl high styrene solution styrene-butadiene rubber, 20 phr of liquid reinforcing resin, 110 phr of reinforcing carbon black, 3 phr of zinc oxide, 4.5 phr of antioxidant, 1.5 phr of stearic acid, 2 phr of protective wax, 1.8 phr of sulfur masterbatch particles, and 1.2 phr of accelerator CBS masterbatch particles.

[0024] As an optional embodiment of this application, the latex styrene-butadiene rubber has a styrene content of 40% and a filler oil content of 50 phr. Preferably, the latex styrene-butadiene rubber is SBR1714, produced by Qilu Petrochemical Company, which is essentially a styrene-butadiene rubber with good grip performance, high tensile strength, and high temperature resistance. Preferably, the high vinyl high styrene solution-polymerized styrene-butadiene rubber is SE6233, a product manufactured by Sumitomo Chemicals (distributed by Shanghai Lishenxing International Trade Co., Ltd.), which can provide the tread compound of this application with high grip and rapid heat generation performance.

[0025] As an optional embodiment of this application, the sulfur masterbatch contains 80 wt% sulfur, and the CBS content of the accelerator CBS masterbatch is 80 wt%. The accelerator CBS is N-cyclohexylbenzothiazole-2-sulphenamide, also known as rubber accelerator CZ, with foreign names including Accelerator CZ. Its molecular formula is C... 13 H 16 N2S2, CAS number 95-33-0, density 1.26 g / cm³ 3 It has a melting point of 93℃~100℃, poor water solubility at room temperature, and low vapor pressure. The CBS-80 used in this application (containing 80% CBS and 20% carrier and dispersant) is a grayish-white granule, a highly reactive post-curing accelerator with excellent anti-scorch properties, safe processing, and short vulcanization time. It belongs to the category of post-curing rubber accelerators and is mainly used in the vulcanization processes of natural rubber, synthetic rubber, and tires, improving the physical properties of rubber products by delaying vulcanization. The sulfur masterbatch granules are preferably S-80, a pre-dispersed vulcanizing agent composed of 80% sulfur and 20% carrier material, used to improve the vulcanization efficiency and safety of rubber.

[0026] As an optional embodiment of this application, the liquid reinforcing resin is an alkylphenol compound, obtained by decarboxylation distillation of shell oil, and is a bio-renewable, non-food chain phenolic resin. Preferably, the liquid reinforcing resin is B136, produced by Jiangsu Qixiang. Adding the B136 liquid reinforcing resin described in this application can improve the rapid heating performance of the mixture and its grip under low-temperature conditions.

[0027] As an optional embodiment of this application, the nitrogen adsorption specific surface area (NSA) of the reinforcing carbon black is 180 m². 2 / g~200m 2 / g, Statistical thickness surface area (STSA, also known as external surface area) is 150m². 2 / g~180m 2 / g. Preferably, the reinforcing carbon black is BDX101 special ultrafine particle size reinforcing carbon black produced by Shandong Shuoyuan New Materials, whose specific surface area is much higher than that of N100 and N200 (NSA / STSA 150 / 130) series carbon blacks. The BDX101 carbon black used in this application has an ultrafine particle size and high structure, and is the variety of rubber carbon black with the highest reinforcement and wear resistance for tire treads. It has strong tire grip and strong dynamic and static balance capabilities, and is mainly used in high-performance tires and racing tires. Furthermore, the BDX101 of this application, when mixed with SBR1714 and SE6233, can improve the hysteresis loss of the tread rubber under high temperature and high speed conditions, as well as the stability of grip under high temperature and high speed conditions.

[0028] As an optional embodiment of this application, the antioxidant includes an amine antioxidant, which includes at least one of antioxidant RD and / or antioxidant 4020. When antioxidant RD and antioxidant 4020 are used in combination, the mass ratio of antioxidant RD to antioxidant 4020 is 2:1. Antioxidant RD and antioxidant 4020 described in this application are both products of Shandong Shangshun Chemical Co., Ltd. Rubber antioxidant 4020 is a p-phenylenediamine-based rubber antioxidant with good compatibility with rubber, is not prone to blooming, is not easily volatile, has low toxicity, and possesses excellent resistance to oxidation, ozone, flexural cracking, and sun-induced cracking. It also has a strong inhibitory effect on harmful metals such as copper and manganese, and is suitable for various synthetic and natural rubbers. Rubber antioxidant 4020 has good dispersibility in rubber compounds, softens the rubber compound, and has little impact on vulcanization. Antioxidant RD is a ketamine rubber protectant with the chemical name 2,2,4-trimethyl-1,2-dihydroquinoline polymer.

[0029] Secondly, based on a general inventive concept, this application also provides a method for preparing go-kart tire tread compound, which employs a combination of a mixer and an extruder, such as... Figure 1 As shown, it includes the following steps: S1. Add emulsion styrene-butadiene, high vinyl high styrene solution styrene-butadiene, zinc oxide, antioxidant, protective wax, stearic acid and reinforcing carbon black into the internal mixer, and control the temperature of the internal mixer discharge gate, mixing chamber and rotor to 65℃~75℃ and the initial mixing speed to 45rpm~60rpm for 15s~30s.

[0030] S2. When the mixing temperature rises to 115℃~125℃, add liquid reinforcing resin and mix. After reaching the set discharge temperature of 140℃~150℃, discharge to obtain the mixed rubber.

[0031] S3. The mixed rubber, sulfur masterbatch particles and accelerator CBS masterbatch particles are put into an extruder and mixed, and then extruded and kneaded for 70s~90s to obtain the product.

[0032] In step S1 of this application, the rubber matrix, solid additives, and reinforcing carbon black are first added, without the addition of liquid resin and vulcanizing agent. The rubber softens at a low temperature of 65℃~75℃ to form an elastic matrix, providing a carrier for the subsequent dispersion of carbon black and additives. The solid additives (such as antioxidants and protective waxes) are added at a low temperature to avoid volatilization loss caused by high temperature. In step S2, when the mixing temperature rises to 115℃~125℃, the liquid reinforcing resin is added. Within this temperature range, the rubber viscosity decreases to a suitable range, and the liquid resin can quickly... It quickly penetrates to the rubber-carbon black interface, filling the gaps between carbon black aggregates and maximizing the synergistic reinforcing effect of resin and carbon black (improving tear resistance and abrasion resistance); in step S3, the vulcanizing agent (sulfur masterbatch particles) and accelerator are added to the extruder instead of being mixed with other raw materials in the internal mixer. The operating temperature of the extruder is usually lower than that of the internal mixer (especially the temperature of the feeding section can be controlled at 80℃~100℃), which can avoid the vulcanization system from being activated prematurely in high-temperature internal mixing (i.e., scorching, which causes the rubber compound to harden and become unprocessable).

[0033] In this application, the mixed rubber after unloading from the internal mixer can directly enter the extruder without intermediate cooling and reheating (traditional processes require reheating to the processing temperature after cooling, which is energy-intensive and time-consuming), significantly improving production efficiency (especially suitable for the mass production needs of go-kart tires). Furthermore, the coordinated operation of the internal mixer and extruder reduces the rubber compound's exposure time to air, avoiding contamination caused by moisture absorption and dust settling during cooling, and improving the cleanliness of the tread rubber (impurities reduce tread wear resistance and may even lead to cracking during use).

[0034] The technical solutions described above in this application will be explained in detail below with reference to specific embodiments.

[0035] Example 1 This embodiment provides a go-kart tire tread compound, comprising the following raw materials: Emulsion styrene-butadiene rubber SBR1714, 60 phr High-vinyl-high-styrene solution-polymerized styrene-butadiene rubber SE6233, 40 phr. Liquid reinforcing resin B136, 15 phr. Special ultrafine reinforcing carbon black BDX101, 90 phr. Zinc oxide (99.7%, effective zinc oxide content), totaling 3 phr. Anti-aging agent 4020, 3 phr. Anti-aging agent RD, calculated at 1.5 phr. Stearic acid, 1.5 phr Protective wax RW220 (Jiangsu Ruiba Chemical Materials), 2 phr. Sulfur masterbatch granules-80, totaling 2 phr. And accelerator CBS-80 masterbatch particles, totaling 1.2 phr.

[0036] The go-kart tire tread compound of this embodiment is prepared by the following method: (1) Emulsion styrene-butadiene rubber SBR1714 and high vinyl high styrene solution styrene-butadiene rubber SE6233 are put into F370 internal mixer and mixed at 50 rpm for 20 s. The top bolt of the internal mixer is lifted, and special ultrafine reinforcing carbon black BDX101, zinc oxide, antioxidant 4020, antioxidant RD, stearic acid and protective wax RW220 are put into the internal mixer for mixing through the feeding gate and the filling conveying pipe, respectively.

[0037] (2) When the temperature rises to 120°C, add liquid reinforcing resin B136 and continue mixing until the temperature rises to 145°C and then unload to obtain the mixture.

[0038] (3) The mixture is fed into a multi-screw extruder, extruded and mixed for 80 seconds, and then sheeted, cooled and collected to obtain the tread rubber of the go-kart tire.

[0039] Example 2 This embodiment provides a go-kart tire tread compound, comprising the following raw materials: Emulsion styrene-butadiene rubber SBR1714, 50 phr High-vinyl-high-styrene solution-polymerized styrene-butadiene rubber SE6233, 50 phr. Liquid reinforcing resin B136, 20 phr. Special ultrafine reinforcing carbon black BDX101, 100 phr. Zinc oxide (99.7%), 3 phr. Anti-aging agent 4020, 3 phr. Anti-aging agent RD, calculated at 1.5 phr. Stearic acid, 1.5 phr Protective wax RW220, 2 phr Sulfur masterbatch granules-80, totaling 1.9 phr. And accelerator CBS-80 masterbatch particles, totaling 1.1 phr.

[0040] The go-kart tire tread compound of this embodiment is prepared by the following method: (1) Emulsion styrene-butadiene rubber SBR1714 and high vinyl high styrene solution styrene-butadiene rubber SE6233 are put into F370 internal mixer and mixed at 50 rpm for 20 s. The top bolt of the internal mixer is lifted, and special ultrafine reinforcing carbon black BDX101, zinc oxide, antioxidant 4020, antioxidant RD, stearic acid and protective wax RW220 are put into the internal mixer for mixing through the feeding gate and the filling conveying pipe, respectively.

[0041] (2) When the temperature rises to 120°C, add liquid reinforcing resin B136 and continue mixing until the temperature rises to 145°C and then unload to obtain the mixture.

[0042] (3) The mixture is fed into a multi-screw extruder, extruded and mixed for 80 seconds, and then sheeted, cooled and collected to obtain the tread rubber of the go-kart tire.

[0043] Example 3 This embodiment provides a go-kart tire tread compound, comprising the following raw materials: Emulsion styrene-butadiene rubber SBR1714, 60 phr High-vinyl-high-styrene solution-polymerized styrene-butadiene rubber SE6233, 40 phr. Liquid reinforcing resin B136, 25 phr. Special ultrafine reinforcing carbon black BDX101, 110 phr. Zinc oxide (99.7%), 3 phr. Anti-aging agent 4020, 3 phr. Anti-aging agent RD, calculated at 1.5 phr. Stearic acid, 1.5 phr Protective wax RW220, 2 phr Sulfur masterbatch granules-80, totaling 1.8 phr. And accelerator CBS-80 masterbatch particles, totaling 1.2 phr.

[0044] The go-kart tire tread compound of this embodiment is prepared by the following method: (1) Emulsion styrene-butadiene rubber SBR1714 and high vinyl high styrene solution styrene-butadiene rubber SE6233 are put into F370 internal mixer and mixed at 50 rpm for 20 s. The top bolt of the internal mixer is lifted, and special ultrafine reinforcing carbon black BDX101, zinc oxide, antioxidant 4020, antioxidant RD, stearic acid and protective wax are put into the internal mixer for mixing through the feeding gate and the filling conveying pipe, respectively.

[0045] (2) When the temperature rises to 120°C, add liquid reinforcing resin B136 and continue mixing until the temperature rises to 145°C and then unload to obtain the mixture.

[0046] (3) The mixture is fed into a multi-screw extruder, extruded and mixed for 80 seconds, and then sheeted, cooled and collected to obtain the tread rubber of the go-kart tire.

[0047] Comparative Example 1 This comparative example provides a tread compound, comprising the following raw materials: SBR1712 rubber (containing 25wt% styrene, oil extrusion of 37.5 phr, Qilu Petrochemical) 50 phr High-vinyl-high-styrene solution-polymerized styrene-butadiene rubber SE6233, 50 phr. Liquid reinforcing resin B136, 20 phr. Special ultrafine reinforcing carbon black BDX101, 100 phr. Zinc oxide (99.7%), 3 phr. Anti-aging agent 4020, 3 phr. Anti-aging agent RD, calculated at 1.5 phr. Stearic acid, 1.5 phr Protective wax RW220, 2 phr Sulfur masterbatch granules, totaling 2 phr. And accelerator CBS masterbatch particles, totaling 1 phr.

[0048] The tread compound of this comparative example was prepared by the following method: (1) SBR1712 rubber and high vinyl high styrene solution polystyrene rubber SE6233 are put into F370 internal mixer and mixed at 50 rpm for 20 s. The top bolt of the internal mixer is lifted, and special ultrafine reinforcing carbon black BDX, zinc oxide, antioxidant 4020, antioxidant RD, stearic acid and protective wax are put into the internal mixer for mixing through the feeding gate and the filling conveying pipe respectively.

[0049] (2) When the temperature rises to 120°C, add liquid reinforcing resin B136 and continue mixing until the temperature rises to 145°C and then unload to obtain the mixture.

[0050] (3) The mixture is fed into a multi-screw extruder, extruded and mixed for 80 seconds, and then sheeted, cooled and collected to obtain the tread rubber of the go-kart tire.

[0051] Comparative Example 2 This comparative example provides a tread compound, comprising the following raw materials: High-oil-filled, high-styrene emulsion styrene-butadiene polystyrene (SBR1714), 50 phr. Solution-polymerized styrene-butadiene rubber HPR755 (40% styrene, 39% vinyl, JSR Japan product), 50 phr. Liquid reinforcing resin B136, 20 phr. Special ultrafine reinforcing carbon black BDX101, 100 phr. Zinc oxide (99.7%), 3 phr. Anti-aging agent 4020, 3 phr. Anti-aging agent RD, calculated at 1.5 phr. Stearic acid, 1.5 phr Protective wax RW220, 2 phr Sulfur masterbatch granules, totaling 2 phr. And accelerator CBS masterbatch particles, totaling 1 phr.

[0052] The tread compound of this comparative example was prepared by the following method: (1) High oil-filled, high styrene-based emulsion styrene-butadiene SBR1714 and solution styrene-butadiene HPR755 are put into an F370 internal mixer and mixed at 50 rpm for 20 s. The top bolt of the internal mixer is then lifted, and special ultrafine reinforcing carbon black BDX, zinc oxide, antioxidant 4020, antioxidant RD, stearic acid and protective wax are put into the internal mixer for mixing through the feeding gate and the packing conveyor pipe, respectively.

[0053] (2) When the temperature rises to 120°C, add liquid reinforcing resin B136 and continue mixing until the temperature rises to 145°C and then unload to obtain the mixture.

[0054] (3) The mixture is fed into a multi-screw extruder, extruded and mixed for 80 seconds, and then sheeted, cooled and collected to obtain the tread rubber of the go-kart tire.

[0055] Comparative Example 3 This comparative example provides a tread compound, comprising the following raw materials: High-oil-filled, high-styrene emulsion styrene-butadiene polystyrene (SBR1714), 50 phr. High vinyl high styrene solution polystyrene, 50 phr Reinforcing carbon black N110, 100 phr Zinc oxide (99.7%), 3 phr. Anti-aging agent 4020, 3 phr. Anti-aging agent RD, calculated at 1.5 phr. Stearic acid, 1.5 phr Protective wax RW220, 2 phr Sulfur masterbatch granules, totaling 2 phr. And accelerator CBS masterbatch particles, totaling 1 phr.

[0056] The tread compound of this comparative example was prepared by the following method: (1) High oil-extended high styrene-based emulsion styrene-butadiene SBR1714 and high vinyl high styrene solution styrene-butadiene are put into F370 internal mixer and mixed at 50 rpm for 20 s. The top bolt of the internal mixer is lifted, and reinforcing carbon black N110, zinc oxide, antioxidant 4020, antioxidant RD, stearic acid and protective wax are put into the internal mixer for mixing through the feeding gate and the packing conveyor pipe, respectively.

[0057] (2) When the temperature rises to 120°C, add liquid reinforcing resin B136 and continue mixing until the temperature rises to 145°C and then unload to obtain the mixture.

[0058] (3) The mixture is fed into a multi-screw extruder, extruded and mixed for 80 seconds, and then sheeted, cooled and collected to obtain the tread rubber of the go-kart tire.

[0059] Comparative Example 4 This comparative example provides a tread compound, comprising the following raw materials: High-oil-filled, high-styrene emulsion styrene-butadiene polystyrene (SBR1714), 50 phr. High vinyl high styrene solution polystyrene, 50 phr Special ultrafine reinforcing carbon black BDX101, 100 phr. Zinc oxide (99.7%), 3 phr. Anti-aging agent 4020, 3 phr. Anti-aging agent RD, calculated at 1.5 phr. Stearic acid, 1.5 phr Protective wax RW220, 2 phr WSR5000 ordinary anti-slip resin (manufactured by Rebar), 20 phr. Sulfur masterbatch granules, totaling 2 phr. And accelerator CBS masterbatch particles, totaling 1 phr.

[0060] The tread compound of this comparative example was prepared by the following method: (1) High oil-extended high styrene-based emulsion styrene-butadiene SBR1714 and high vinyl high styrene solution styrene-butadiene are put into F370 internal mixer and mixed at 50 rpm for 20 s. The top bolt of the internal mixer is lifted, and special ultrafine reinforcing carbon black BDX, zinc oxide, antioxidant 4020, antioxidant RD, stearic acid and protective wax are put into the internal mixer for mixing through the feeding gate and the packing conveyor pipe.

[0061] (2) When the temperature rises to 120°C, add ordinary anti-slip resin WSR5000 and continue mixing until the temperature rises to 145°C and then unload to obtain the mixture.

[0062] (3) The mixture is fed into a multi-screw extruder, extruded and mixed for 80 seconds, and then sheeted, cooled and collected to obtain the tread rubber of the go-kart tire.

[0063] The tread rubbers of Examples 1-3 and Comparative Examples 1-4 of this application were subjected to DMA testing using a thermal dynamics analyzer. The test conditions were: double cantilever, temperature ramp frequency scan, frequency 10 Hz, strain 5%. The results are shown in Table 1.

[0064] Table 1 Performance Test Data

[0065] In Table 1, Tanδ represents the loss factor, which directly reflects grip and is used to verify the grip improvement effect across all scenarios. A higher Tanδ value indicates greater energy loss between the rubber and the ground, resulting in stronger grip (0℃ corresponds to low-temperature starting grip, 30℃ to normal-temperature racing grip, and 80℃ to continuous racing high-temperature grip). The rebound rate at 100℃ in Table 1 is used to verify high-temperature stability. A lower rebound rate indicates greater energy loss in the rubber at high temperatures (more energy is converted into grip) rather than wasted through elastic recovery, making it a key indicator of high-temperature grip stability.

[0066] Table 1 shows at least the following: Comparative Example 1 uses SBR1712 with low styrene content, resulting in a decrease in its Tanδ, thus affecting the tread rubber's grip. Comparative Example 2 uses HBR755 with low vinyl content, which also leads to a decrease in Tanδ. This is because SE6233 of this application can enhance the rigidity and ground adhesion of rubber at different temperatures by increasing the glass transition temperature (Tg), making it a core rubber type for improving grip in all scenarios. Comparative Example 3 uses conventional carbon black N110, which cannot replace the special ultrafine carbon black BX101 of this application and cannot guarantee the stability of the reinforcing network at high temperatures, thus leading to a decrease in grip at high temperatures. Comparative Example 4 uses ordinary anti-slip resin, which cannot produce a synergistic reinforcing effect with the special ultrafine carbon black BX101 of this application, also leading to a decrease in grip. The tread rubber prepared in Examples 1-3 of this application has a rebound rate of only 20%~22%, which is significantly lower than that of the tread rubber in Comparative Examples 1-4. This proves that the vulcanization system and the protective system of this application can form a stable cross-linked network. At high temperatures of 80℃~100℃, it can avoid the excess elasticity caused by the intensified thermal motion of rubber molecular chains, ensuring that energy is preferentially used for grip rather than rebound loss, thus perfectly solving the problem of grip attenuation at high temperatures during continuous racing.

[0067] While specific embodiments of this application have been described in detail, this should not be construed as limiting the scope of protection of this application. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this application.

Claims

1. A go-kart tire tread compound, characterized in that, Including the following raw materials: Emulsion styrene-butadiene rubber 40 phr~60 phr, high vinyl high styrene solution styrene-butadiene rubber 40 phr~60 phr, liquid reinforcing resin 15 phr~25 phr, reinforcing carbon black 90 phr~120 phr, zinc oxide 2 phr~5 phr, antioxidant 3 phr~5 phr, stearic acid 1 phr~2 phr, protective wax 2 phr~5 phr, sulfur masterbatch granules 1 phr~3 phr, and accelerator CBS masterbatch granules 1 phr~3 phr.

2. The go-kart tire tread compound according to claim 1, characterized in that, Including the following raw materials: Emulsion styrene-butadiene rubber 60 phr, high vinyl high styrene solution styrene-butadiene rubber 40 phr, liquid reinforcing resin 20 phr, reinforcing carbon black 110 phr, zinc oxide 3 phr, antioxidant 4.5 phr, stearic acid 1.5 phr, protective wax 2 phr, sulfur masterbatch granules 1.8 phr, and accelerator CBS masterbatch 1.2 phr.

3. The go-kart tire tread compound according to claim 1, characterized in that, The emulsion styrene-butadiene rubber has a styrene content of 40% and a filler oil content of 50 phr.

4. The go-kart tire tread compound according to claim 1, characterized in that, The sulfur masterbatch contains 80 wt% sulfur, and the accelerator CBS masterbatch contains 80 wt% CBS.

5. The go-kart tire tread compound according to claim 1, characterized in that, The liquid reinforcing resin is an alkylphenol compound, obtained by decarboxylation and distillation of shell oil.

6. The go-kart tire tread compound according to claim 1, characterized in that, The nitrogen adsorption specific surface area of ​​the reinforcing carbon black is 180 m². 2 / g~200m 2 / g, statistical thickness surface area is 150m² 2 / g~180m 2 / g.

7. The go-kart tire tread compound according to claim 1, characterized in that, The antioxidant includes an amine antioxidant, which includes at least one of antioxidant RD and / or antioxidant 4020, wherein the mass ratio of antioxidant RD to antioxidant 4020 is 2:

1.

8. A method for preparing a go-kart tire tread compound according to any one of claims 1-7, characterized in that, The operation of the internal mixer and extruder in conjunction includes the following steps: Emulsion styrene-butadiene, high vinyl high styrene solution styrene-butadiene, zinc oxide, antioxidant, protective wax, stearic acid and reinforcing carbon black are put into an internal mixer, and the temperature of the internal mixer discharge door, mixing chamber and rotor is controlled at 65℃~75℃ for the initial mixing. When the mixing temperature reaches the set value, liquid reinforcing resin is added and mixed. After reaching the set unloading temperature, the mixture is unloaded to obtain the mixed adhesive. The mixture is prepared by feeding the mixed rubber, sulfur masterbatch particles and accelerator CBS masterbatch particles into an extruder, mixing them, and then extruding and compounding them.

9. The method for preparing go-kart tire tread compound according to claim 8, characterized in that, The set value is 115℃~125℃, and the set unloading temperature is 140℃~150℃.

10. The method for preparing go-kart tire tread compound according to claim 8, characterized in that, The mixing speed of the internal mixer is 45 rpm to 60 rpm, the initial mixing time is 15 s to 30 s, and the extrusion mixing time is 70 s to 90 s.

Images