Rubber tire reinforcing filler and preparation method thereof

Abstract

The invention belongs to the field of rubber tire manufacturing, and particularly relates to a rubber tire reinforcing filler and a preparation method thereof. The method comprises the following steps: 1) putting steel fiber powder into an aluminum-containing treatment solution, carrying out surface treatment, adjusting a solution system to be alkaline, and aging to obtain modified steel fibers; 2) preparing steel wire glue, and uniformly spraying the steel wire glue on the surface of the modified steel fiber by adopting an electrostatic charge spraying method to obtain a functional fiber; and 3) preparing a composite adhesive, placing the functional fibers in the composite adhesive for negative pressure impregnation, then filtering, rolling, curing and pre-vulcanizing to obtain the rubber tire reinforcing filler. According to the invention, a special microstructure is constructed through etching deposition, and is combined with the silane coupling agent functionalized steel wire glue and the organic functionalized composite glue layer, so that the interface bonding strength between the filler and the steel wire core gold, the glue coating material and other components in the bridle layer is obviously improved, and the uniform dispersion and fixation of steel fibers in the bridle layer are realized by using a small amount of the filler; the specific gravity is greatly reduced, and the properties such as puncture resistance and wear resistance are reserved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of rubber tire manufacturing, and particularly relates to a rubber tire reinforcing filler and a preparation method thereof. BACKGROUND

[0002] Traditional tires mostly use fiber materials such as nylon, which can meet the basic driving requirements, but gradually expose the disadvantages of insufficient strength and poor durability when facing the increasingly complex road conditions and high-performance vehicle requirements. Under this background, steel wire tires emerged as the times require, which uses steel wire cord as the skeleton material to achieve a major leap in performance.

[0003] The main performance advantages of steel wire tires are remarkable. Its strength far exceeds that of ordinary tires, and when carrying heavy vehicles such as large trucks and engineering vehicles, it can effectively resist road impact and heavy pressure, reduce the probability of deformation and damage, and protect transportation efficiency and driving safety. At the same time, the durability of steel wire tires is excellent, which can withstand long-term high-strength operation, prolong the tire replacement cycle, and reduce maintenance costs, which is particularly important for long-distance transport vehicles. In terms of control stability, steel wire tires, with good deformation resistance, can maintain precise steering response and stable driving posture when driving at high speed, emergency braking and rapid turning, improving driving experience and safety.

[0004] Due to the special structure of steel wire tires, there is a special steel wire belt, and it is usually arranged in multiple layers. Different layers of steel wire tires are suitable for different vehicle types and use scenarios. For example, two-layer belts are commonly used as highway tires, while three-layer and four-layer belt steel tires are usually used as special transport vehicles. However, its high strength and high durability far exceed the actual demand, resulting in waste of vehicle performance resources and increased manufacturing costs. In addition, the specific gravity and density of steel wire tires are large, which increases the weight of the tire itself. For some new energy vehicles and other models that have strict requirements on vehicle lightweight, it will consume additional power, reduce the range, affect the overall performance of the vehicle, and also increase fuel consumption and carbon emissions during vehicle transportation to some extent, and there is also a certain performance surplus. For special vehicles, the problem of excessive specific gravity also limits the use of more layers of belts to further enhance the performance of the tire. Therefore, at the current stage, one important direction of the research on steel wire tires is how to maintain its performance as much as possible while realizing the lightweight of the steel wire tire. The cooperation of filler and steel wire core gold (i.e. steel wire that constitutes the steel cord) to build a new type of belt is an important research and development direction. However, the common filler and steel wire core gold have low cooperation degree, and even may have segregation and other problems, resulting in performance far from expected, so the research on the filler is always an important topic for the lightweight of the steel wire tire. SUMMARY

[0005] In order to solve the problems of the existing steel wire belt layer, such as the excessive specific gravity density, the excessive tire performance in some scenarios, the influence on the vehicle performance, and the limitation of the application of more belt layer in some special scenarios, the application provides a rubber tire reinforcing filler and a preparation method of the filler.

[0006] The main purpose of the application is to: 1. Construct a special filler suitable for steel wire belt layer.

[0007] 2. The filler has good compatibility with the rubber coating material of the steel wire belt layer and the steel wire core.

[0008] 3. The filler can greatly reduce the specific gravity of the steel wire belt layer after use, and effectively maintain most of the performance of the belt layer.

[0009] In order to achieve the above purpose, the application adopts the following technical scheme.

[0010] A preparation method of a rubber tire reinforcing filler, the method comprises the following steps: 1) placing steel fiber powder in an aluminum-containing treatment solution, adjusting the solution system to alkaline after surface treatment, and aging to obtain modified steel fiber.

[0011] 2) Prepare steel wire glue, and uniformly spray the steel wire glue on the surface of the modified steel fiber by using electrostatic charge spraying method to obtain functionalized fiber.

[0012] 3) Prepare a composite glue, and place the functionalized fiber in the composite glue for negative pressure immersion, and then filter, roll curing and pre-sulfurization to obtain the rubber tire reinforcing filler.

[0013] As a preferred, the steel fiber powder in step 1) is a short fiber powder with a length of 0.300-0.400 mm; the aluminum-containing treatment solution in step 1) is a mixed iron-aluminum acid solution, which is prepared by the following method: first, industrial hydrochloric acid and industrial hydrofluoric acid are mixed with water to prepare an acidic base solution, the concentration of industrial hydrochloric acid in the acidic base solution is 110-130 mL / L, and the concentration of industrial hydrofluoric acid is 10-20 mL / L, then iron chloride is added according to the dosage ratio of 3.0-4.0 mol / L of the acidic base solution, and aluminum chloride is added according to the dosage ratio of 0.3-0.8 mol / L of the acidic base solution, and the mixture is stirred uniformly to obtain the mixed iron-aluminum acid solution.

[0014] As a preferred, the surface treatment in step 1) is to place the steel fiber powder in the aluminum-containing treatment solution, and stir at 55-65℃ for 10-15min; the solution system is adjusted to alkaline by blowing ammonia gas into the solution system until the pH value is greater than or equal to 12, then standing for 25-35min, filtering and drying to obtain the modified steel fiber.

[0015] As preferred, the steel wire rubber component in step 2) is 33-35wt% carbon black N330, 3-5wt% silane coupling agent KH-550, 1-2wt% sulfur, and the balance is natural rubber, after the components are distributed, the temperature is 100-110℃, the rotation speed is 40-60rpm, and the environment is stirred for 15-20min, and then broken to a mesh size of ≥800 mesh to obtain the steel wire rubber.

[0016] As preferred, the control parameters of the electrostatic spraying method in step 2) are: voltage 50-80kV, spraying distance 20-30cm, rubber layer thickness 80-120μm, and after spraying, the temperature is 90-110℃, and the environment is kept for 5-8min to obtain the functionalized fiber.

[0017] As preferred, the composite rubber in step 3) is prepared by the following method: uniformly mixing natural rubber latex, peroxoacetic acid, carbon black N550 and nano white carbon black in a mass ratio of 5: (1.4-1.6):2.5: (0.3-0.5), and stirring and mixing under the conditions of a temperature of 30-40℃ and a pressure of 0.5-1.0MPa for 1-2h to obtain the composite rubber.

[0018] As preferred, the control environment pressure of the negative pressure impregnation process in step 3) is ≤0.1 atm; the rolling curing process in step 3) is to place the material under the conditions of 70-80℃ and continuously stirring and rolling at a rotation speed of 30-90rpm for 25-35min; the pre-vulcanization process in step 3) controls the temperature to be 120-130℃, the pressure to be 0.5-0.8Mpa, and the vulcanization time to be 10-15min.

[0019] A rubber tire reinforcing filler.

[0020] As preferred, the rubber tire reinforcing filler is used for filling the steel wire belt of the tire.

[0021] As preferred, when the rubber tire reinforcing filler is used for filling the steel wire belt of the tire, it is added to the rubber coating material and uniformly mixed; the rubber tire reinforcing filler is added in an amount of 15-25wt% of the rubber coating material, and the steel wire cord density is reduced by 30-50%.

[0022] In the technical scheme of the present application, the core is to realize the significant improvement of the adhesion performance of the rubber tire reinforcing filler through the interface microstructure design, chemical bonding strengthening and organic-inorganic synergistic effect, and successfully prepare a high-performance rubber tire reinforcing filler.

[0023] First, the pretreatment of the steel wire microstructure. The present invention uses a special aluminum-containing oxide etching solution to etch the surface of the steel fiber, which is used to construct micro-nanoscale grooves and pores on the surface of the steel fiber. This unique microstructure design utilizes the dual effects of mechanical anchoring effect and capillary infiltration effect, thereby significantly increasing the amount of adhesive attached. Specifically, the rough surface formed by extrusion provides a large number of stable physical anchoring points for the adhesive. These surface grooves and pores cooperate with each other to form a special "locking structure". Under dynamic load conditions, this "locking structure" creates a strong mechanical bite between the adhesive layer and the steel wire, which can effectively inhibit the occurrence of interfacial slip and significantly reduce the risk of peeling. At the same time, the capillary force generated by the microporous structure plays a key role. It drives the adhesive to penetrate quickly and deeply into the pores. Compared with traditional smooth surfaces, the infiltration depth of the adhesive is greatly improved. This microstructure design not only lays a good physical foundation for subsequent chemical bonding and synergistic effects, but also the reinforcement effect it brings directly acts on the adhesion performance of the rubber tire reinforcing filler.

[0024] Then, by adjusting the pH value, aluminum oxide compounds such as ferric aluminate and iron oxide compounds are further deposited on the rough surface of the etched steel fiber, which provides a good basis for subsequent coupling condensation and chemical bridging.

[0025] The modified steel fibers, through the multi-stage action of the steel wire adhesive, first form a three-stage chemical bonding system (steel fiber-adhesive layer-rubber), a key feature of the present invention that enhances interfacial strength. This system, closely integrated with the previously described microstructure design, further strengthens and enhances the performance of the rubber tire reinforcing filler. KH-550, a key coupling agent, reacts with the silanol (-Si-OH) groups on the steel wire surface through condensation reactions with oxides (such as Fe-O, Al-O) and aluminates (M-Al-O) to form stable MO-Si bonds, establishing the initial chemical bridge between the steel fiber and adhesive layer. Furthermore, the amino (-NH2) groups at the coupling agent's terminals also form hydrogen bonds with carboxyl (-COOH) groups in the rubber, further strengthening this connection. More importantly, the filler of this invention undergoes a pre-vulcanization treatment, initially forming crosslinks between the rubber molecular chains. Later, during belt processing and rubber coating, the vulcanization process is completed, forming CSSC crosslinks. This cross-linking reaction further solidifies the interfacial bonding bridged by the coupling agent into a complete and stable overall network structure. This chemical bonding system not only relies on the physical adhesion foundation provided by the aforementioned microstructure design, but also tightly binds the various components together through chemical reactions. This allows the rubber tire reinforcing filler to maintain high stability and reliability under various complex working conditions, achieving a significant increase in interfacial strength. At the same time, it allows the filler of the present invention to be effectively dispersed and stabilized in the belt layer.

[0026] Furthermore, by the synergistic effect of modified natural rubber and nano-filler, stress dispersion and energy dissipation under dynamic load are realized. The coordination between the epoxy groups of epoxidized natural rubber and the contact surface of steel wire core gold, and the nano-white carbon black effectively disperses stress through the "particle-rubber" sliding mechanism, significantly reducing the dynamic modulus difference. The silicon hydroxyl groups (-Si-OH) on the surface of nano-white carbon black are connected to the rubber molecular chain through weak hydrogen bonds. Under the action of dynamic load, the nanoparticles can reversibly slide, converting local stress into heat energy, thereby effectively inhibiting crack propagation. This organic-inorganic synergistic effect not only provides a stable structure through the microstructure design and chemical bonding mentioned above, but also plays a unique role in the dynamic environment, further improving the overall performance of the rubber tire reinforcing filler.

[0027] Through the above treatment, the filler of the present application can effectively integrate into the belt layer, form a crosslinked network interpenetration with the coating material, and be fixed and connected at the same time. The filler is in direct contact with the steel wire core gold cord, and also has good compatibility to realize connection and cooperation.

[0028] Finally, the present application is actually a multi-stage vulcanization process formed by the process of coating material calendering coating in the preparation process of pre-vulcanized belt layer. The multi-stage vulcanization process is the key to the successful implementation of the entire technical solution. The multi-stage vulcanization process is carried out in stages, and the purpose is to avoid the flow of the glue layer leading to the failure of the microstructure filling, while ensuring that the interface chemical bond can fully react. In the pre-vulcanization stage, the glue layer is preliminarily crosslinked to form a gel network. This network structure can effectively fix the glue solution in the microstructure pores, prevent the glue solution from overflowing during high-temperature final vulcanization, and thus ensure the integrity and stability of the microstructure, providing protection for the role of the microstructure designed above. In the final vulcanization stage, the high temperature and high pressure environment accelerates the completion of the sulfur crosslinking reaction, not only promoting the full formation of Fe-O-Si bonds to further strengthen the chemical bonding system, but also helping to improve the rubber crosslinking network, ensuring the integrity of the interface bonding. Through this multi-stage vulcanization process, the microstructure design, chemical bonding strengthening, and organic-inorganic synergistic effect are organically combined, and the overall adhesion performance of the rubber tire reinforcing filler is finally improved.

[0029] The advantage of the present application is that the present application constructs a special microstructure by etching deposition, combines silane coupling agent functionalized steel wire glue and organic functionalized composite glue layer, significantly improves the interfacial adhesion strength of the filler and the steel wire core gold in the belt layer, the coating material and other components, realizes the uniform dispersion and fixation of the steel fiber in the belt layer with less amount, and compared with the conventional belt layer, the steel fiber can realize the replacement of a large amount of steel wire core gold in the steel cord, greatly reduces the specific gravity and retains the performance of puncture resistance, wear resistance and other aspects to a high degree. DETAILED DESCRIPTION

[0030] The present application will be further described in greater detail by way of specific embodiments. Those skilled in the art will be able to implement the present application based on the foregoing description. In addition, the embodiments of the present application involved in the following description are generally only embodiments of a part of the present application, rather than all embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments in the present application without creative labor should fall within the scope of protection of the present application.

[0031] Unless otherwise specified, the raw materials used in the embodiments of the present application are commercially available or available to those skilled in the art. Unless otherwise specified, the methods used in the embodiments of the present application are methods mastered by those skilled in the art.

[0032] Unless otherwise specified, the industrial hydrochloric acid used in the embodiments of the present application is commercially available industrial hydrochloric acid with a standard concentration of 38 wt%. The industrial hydrofluoric acid used in the embodiments of the present application is commercially available industrial hydrofluoric acid with a standard concentration of 48 wt%.

[0033] Embodiment 1: A method for preparing a rubber tire reinforcing filler, the method comprising: 1) mixing industrial hydrochloric acid and industrial hydrofluoric acid with water to prepare an acidic base solution, the concentration of industrial hydrochloric acid in the acidic base solution being 110 mL / L, the concentration of industrial hydrofluoric acid in the acidic base solution being 10 mL / L, then adding iron chloride according to a dosage ratio of 3.0 mol / L of the acidic base solution, and adding aluminum chloride according to a dosage ratio of 0.3 mol / L of the acidic base solution, and stirring to obtain a mixed iron-aluminum acid solution.

[0034] 2) Put 0.300 mm short fiber steel fiber powder into the aluminum-containing treatment solution, stir for 15 min in a constant temperature environment of 55°C, carry out surface treatment, then pass ammonia gas into the solution system to a pH value of 12, then stand for 35 min, filter and dry to obtain modified steel fiber.

[0035] 3) 33 wt% carbon black N330, 3 wt% silane coupling agent KH-550, 1 wt% sulfur, and the balance being natural rubber, after the above components are dosed, the temperature is 100°C, the rotation speed is 40 rpm, and the environment is stirred for 20 min, then crushed to a mesh size of 800 mesh to obtain steel wire glue.

[0036] 4) The steel wire glue is uniformly sprayed on the surface of the modified steel fiber by using electrostatic charge spraying method, the electrostatic spraying voltage is 50 kV, the spraying distance is 20 cm, the glue layer thickness is 80 μm, and after the spraying is completed, the temperature is 90°C, and the environment is kept for 8 min to obtain functionalized fiber.

[0037] 5) The natural rubber latex, peroxoacetic acid, carbon black N550 and nano white carbon black are mixed uniformly according to the mass ratio of 5:1.4:2.5:0.3, and stirred and mixed under the environmental conditions of temperature 30℃ and pressure 0.5MPa for 2h, to obtain a composite glue.

[0038] 6) The functionalized fiber is placed in the composite glue to perform negative pressure impregnation under the controlled environmental pressure of 0.1atm, and then the material is filtered and placed under the condition of 70℃ for continuous stirring and rolling at the speed of 30rpm for 35min, and then vulcanization is performed under the conditions of temperature 120℃ and pressure 0.5Mpa for 15min, to obtain a rubber tire reinforcing filler.

[0039] 7) The natural rubber, carbon black, zinc oxide, stearic acid, antioxidant 4020, accelerator NS and sulfur are mixed uniformly according to the mass ratio of 100:60:5;2;2:1.5:2, to obtain a coating material.

[0040] 8) The steel cord of the steel cord belt is passed through a double-roller calender, the rubber tire reinforcing filler is added under the environmental conditions of temperature 90℃, and the surface is coated with 1.5mm of the coating material, and then vulcanization is performed under the environmental conditions of temperature 150℃ and pressure 20MPa for 15min, to obtain a reinforced rubber tire.

[0041] A control group is set for step 8) in the example, only the steel cord density and the amount of rubber tire reinforcing filler (the amount is calculated according to the coating material, i.e. the amount of reinforcing filler accounts for the mass percentage of the original coating material, the same below) are changed, and the specific changes are as follows.

[0042] Table 1: Control table of different steel cord densities and filler amounts in Example 1:

[0043] The above S1-1 is a blank group.

[0044] The rubber tires prepared according to the parameters in the above table 1 are subjected to performance detection, and the specific characterization results are as follows.

[0045] Axial (Y-axis) tensile strength detection: cut a dumbbell-shaped sample with a thickness of 2.0±0.2mm along the direction of the steel cord, use a universal testing machine pneumatic clamp with an initial clamp distance of 50mm, record the maximum tension at a stretching rate of 500mm / min. The strength of the blank group S1-1 is defined as 100%.

[0046] Transverse (X-axis) tensile strength detection: cut a dumbbell-shaped sample with a thickness of 2.0±0.2mm along the direction perpendicular to the steel cord, use a universal testing machine pneumatic clamp with an initial clamp distance of 50mm, record the maximum tension at a stretching rate of 500mm / min. The strength of the blank group S1-1 is defined as 100%.

[0047] Abrasion resistance test: The test sample size is a cylinder with a diameter of 16 ± 0.2 mm and a thickness of 6 ± 0.5 mm. The mass is weighed, and a rotating drum abrasion tester is used under the condition of a pressure of 10 N and a H-18 type grinding wheel with a Shore hardness of 90. The sample is rotated for 40 turns, and the mass loss is observed. The abrasion resistance retention rate is calculated based on the mass retention ratio after abrasion. It is specified that the strength of the blank group S1-1 is 100%.

[0048] Puncture resistance test: The example material is cut into a 100x100mm square sheet with a thickness of 2.0±0.1mm, and a puncture tester with a sharp tip diameter of 1.0mm conical needle is used to penetrate the sample at a puncture rate of 50mm / min. The maximum force value during puncture is recorded. It is specified that the strength of the blank group S1-1 is 100%.

[0049] Specific gravity test: The example material is cut into a 10x10x2mm square block, and the specific gravity is calculated using the water displacement method.

[0050] Table 2: Performance test characterization results of Example 1:

[0051] Analyzing the above Table 2 characterization results, the introduction of rubber tire reinforcing fillers has a significant impact on the mechanical anisotropy, interface microstructure, and macroscopic performance of the tire composite system, achieving multi-dimensional optimization of the tire material system.

[0052] From the perspective of mechanical property anisotropy, the experimental groups S1-2 to S1-5 show a significant mechanical property reconstruction effect as the amount of rubber tire reinforcing filler increases. The Y-axis (axial) tensile strength shows a decreasing trend, which is directly related to the decrease in steel cord density; while the X-axis (transverse) tensile strength shows a nonlinear change rule of first increasing and then tending to be stable. This anisotropy transformation phenomenon is attributed to the secondary reinforcing network structure formed by the rubber tire reinforcing filler in the rubber matrix from the material mechanics constitutive relationship analysis. The reinforcing filler establishes a continuous stress transmission path in the transverse direction, filling the mechanical performance "blind area" between the steel cord in the traditional tire structure.

[0053] The durability performance evaluation shows that the wear resistance retention rate of each experimental group is higher than 93%, among which S1-4 and S1-5 reach more than 95%, showing excellent wear resistance characteristics. From the wear mechanism analysis, the wear surface micro-morphology of the filler modified sample is more uniform, and the standard deviation of the wear track width is reduced, which is directly related to the optimization of the energy dissipation mechanism caused by the restriction of the filler on the movement of the rubber molecular chain. It is particularly worth noting that the effective retention of the puncture resistance, the puncture resistance of S1-5 sample is only decreased by about 3% compared with S1-1, and the enhanced filler changes the crack propagation path, promotes the frequent deflection and branching of the crack, prolongs the crack propagation path, and increases the energy dissipation, which is a "crack blunting" mechanism that plays a key role in improving the puncture resistance of the tire.

[0054] Lightweight benefit analysis shows that the introduction of rubber tire reinforcing filler realizes the effective reduction of tire weight under the premise of ensuring performance. With the increase of filler addition amount, the steel wire cord density decreases, and the tire specific gravity decreases from 2.13 g / cm 3 of S1-1 to 1.97 g / cm 3 of S1-5, about 7.51% weight reduction. Lightweight design not only reduces energy consumption in the use stage, but also reduces carbon emissions in the tire production process by reducing the amount of steel wire, realizing the double optimization of economic benefit and environmental benefit.

[0055] Compared with the blank group S1-1, the experimental groups S1-2 to S1-5 realize the coordinated adjustment of multi-dimensional performance such as transverse strength, puncture resistance, wear resistance and lightweight under the premise of meeting the design requirements of axial strength. Especially S1-4 and S1-5 formulations perform best in the balance of various performance indicators, with an average heart function very close to S1-1 experimental group and a significantly decreased specific gravity, representing the best performance balance point that can be achieved under current technical conditions.

[0056] Filler-matrix interface interaction characterization reveals a clear adsorption effect and a positive correlation with the addition amount. With the increase of filler addition amount, the adsorption weight gain rate shows a gradient increase, and this weight gain phenomenon is mainly due to the strong adsorption ability of the filler surface micro-pore structure to the rubber precursor, forming an extended interface layer, and the glue successfully penetrates into the deep micro-pores, forming an effective mechanical anchoring structure.

[0057] The glue absorption capacity is a key parameter for maintaining the mechanical properties of the composite material. Under the condition that the filler addition amount is similar, the S1-4 / S1-5 group with high glue absorption weight gain rate is significantly better than the low glue absorption group S1-3 in the puncture resistance, and the puncture resistance is increased by about 22-28%. The difference can be attributed to the three-dimensional network interface structure formed by the "glue deep penetration micro-pore", which provides a more effective stress transfer path. From the perspective of material-structure-property relationship, this lightweight strategy is essentially realized by optimizing the mechanical transfer path. The traditional tire mainly relies on high-density steel cord to provide mechanical properties, while the present application realizes more efficient stress distribution by constructing a "steel cord-filler-rubber" ternary synergistic system, which makes it possible to reduce the amount of steel wire while maintaining or even improving the overall performance.

[0058] The present application realizes the technical upgrading of the tire material system from the traditional single reinforcing structure to the "steel wire + filler" synergistic reinforcing structure through the innovative application of rubber tire reinforcing filler, which improves the comprehensive performance of the tire while meeting the needs of the automobile industry for lightweight, safety and environmental protection.

[0059] Example 2: A method for preparing a rubber tire reinforcing filler, the method comprising: 1) mixing industrial hydrochloric acid and industrial hydrofluoric acid with water to prepare an acidic base solution, the concentration of industrial hydrochloric acid in the acidic base solution is 120 mL / L, the concentration of industrial hydrofluoric acid is 15 mL / L, then adding iron chloride according to the dosage ratio of 3.5 mol / L acidic base solution, and adding aluminum chloride according to the dosage ratio of 0.55 mol / L acidic base solution, and stirring to obtain a mixed iron-aluminum acid solution.

[0060] 2) Put 0.350 mm short fiber steel fiber powder into the aluminum-containing treatment solution, stir at 60℃ constant temperature for 13 min, then pass ammonia gas into the solution system to pH 13, then stand for 30 min, filter and dry to obtain modified steel fiber.

[0061] 3) 34wt% carbon black N330, 4wt% silane coupling agent KH-550, 1.5wt% sulfur, and the balance is natural rubber, after the above components are dosed, the temperature is 105℃, the rotation speed is 50rpm, and the stirring is carried out for 18min, then crushed to 900 mesh, and the steel cord glue is obtained.

[0062] 4) The steel cord glue is uniformly sprayed on the surface of the modified steel fiber by electrostatic charging spraying method, the electrostatic spraying voltage is 65kV, the spraying distance is 25cm, the glue layer thickness is 100μm, and after the spraying is completed, the functionalized fiber is obtained by keeping the temperature at 100℃ for 7min.

[0063] 5) The natural rubber latex, peroxoacetic acid, carbon black N550 and nano white carbon black were mixed uniformly according to the mass ratio of 5:1.5:2.5:0.4, and then stirred and mixed under the environmental conditions of temperature 35 °C and pressure 0.75 MPa for 1.5 h, to obtain a composite glue.

[0064] 6) The functionalized fiber was placed in the composite glue to perform negative pressure impregnation under the controlled environmental pressure of 0.08 atm, and then the material was filtered and placed under the condition of 75 °C for continuous stirring and rolling at the speed of 60 rpm for 30 min, and then vulcanized under the conditions of temperature 125 °C and pressure 0.65 MPa for 13 min, to obtain a rubber tire reinforcing filler.

[0065] 7) The natural rubber, carbon black, zinc oxide, stearic acid, antioxidant 4020, accelerator NS and sulfur were mixed uniformly according to the mass ratio of 100:60:5;2;2:1.5:2, to obtain a coating material.

[0066] 8) The steel cord of the steel cord belt was passed through a double-roller calender, and the rubber tire reinforcing filler was added to the surface of the steel cord under the environmental conditions of temperature 95 °C and coating thickness 1.5 mm, and then vulcanized under the environmental conditions of temperature 155 °C and pressure 23 MPa for 13 min, to obtain a reinforced rubber tire, and the rubber tire reinforcing filler was added in an amount of 22 wt% of the coating material.

[0067] A control group was set for step 8) in the example, and only the steel cord density was changed, and the specific changes were as follows.

[0068] Table 3: Control table of different steel cord density settings in Example 2

[0069] The rubber tire prepared according to the parameters in Table 3 was subjected to performance detection, and the specific characterization results were as follows.

[0070] Axial (Y-axis) tensile strength detection: a dumbbell-shaped sample with a thickness of 2.0±0.2 mm was cut along the direction of the steel cord, a universal testing machine pneumatic clamp with an initial clamping distance of 50 mm was used, and the maximum tensile force was recorded at a tensile rate of 500 mm / min. The strength of the blank group S1-1 was defined as 100%.

[0071] Transverse (X-axis) tensile strength detection: a dumbbell-shaped sample with a thickness of 2.0±0.2 mm was cut along the direction perpendicular to the steel cord, a universal testing machine pneumatic clamp with an initial clamping distance of 50 mm was used, and the maximum tensile force was recorded at a tensile rate of 500 mm / min. The strength of the blank group S1-1 was defined as 100%.

[0072] Abrasion resistance test: The sample size is a cylinder with a diameter of 16±0.2mm and a thickness of 6±0.5mm. The mass is weighed, and the rotating drum abrasion tester is used under the condition of 10N pressure and H-18 type sand wheel with Shore hardness 90. Rotate 40 times to observe the mass loss and calculate the abrasion resistance retention rate. The blank group S1-1 strength is 100%.

[0073] Puncture resistance test: The example material is cut into a 100x100mm square film with a thickness of 2.0±0.1mm. The puncture tester with a sharp tip diameter of 1.0mm conical needle is used to penetrate the sample at a puncture rate of 50mm / min. The maximum force value during puncture is recorded, and the average value of 5 points is taken. The blank group S1-1 strength is 100%.

[0074] Specific gravity test: The example material is cut into a 10x10x2mm block, and the specific gravity is calculated using the water displacement method.

[0075] Table 4: Performance test characterization results of Example 2:

[0076] Analyzing the above Table 4 characterization results, compared with Example 1, Example 2 further optimizes the performance of the rubber tire reinforcing filler by adjusting the parameters and raw material ratio in the preparation process. Specifically, increasing the concentration of industrial hydrochloric acid and industrial hydrofluoric acid, and increasing the amount of ferric chloride and aluminum chloride, these adjustments make the reaction of iron-aluminum mixed acid solution more sufficient, thereby improving the performance of modified steel fiber. At the same time, the formula of steel wire glue is optimized, the amount of carbon black N330 and silane coupling agent KH-550 is increased, the adhesion and wear resistance of steel wire glue are improved. In addition, the voltage and spraying distance of electrostatic spraying are also increased, and the thickness of the glue layer is increased, so that the preparation of functionalized fibers is more reliable.

[0077] During the preparation of the composite glue, the ratio of each component and the reaction conditions are also adjusted to obtain more uniform mixing effect and higher reaction efficiency. The conditions of negative pressure impregnation and vulcanization are also optimized to ensure that the rubber tire reinforcing filler can fully penetrate into the functionalized fibers to form a good interfacial bond.

[0078] From the performance test results, the rubber tire prepared in Example 2 has a slight decrease in Y-axis tensile strength, but the X-axis tensile strength, wear resistance and puncture resistance are all improved. Especially the puncture resistance, which has a more significant improvement compared with Example 1.

[0079] Example 3: A method for preparing a rubber tire reinforcing filler, the method comprising: 1) mixing industrial hydrochloric acid and industrial hydrofluoric acid with water to prepare an acidic base solution, the concentration of industrial hydrochloric acid in the acidic base solution being 130 mL / L, the concentration of industrial hydrofluoric acid in the acidic base solution being 20 mL / L, then adding iron chloride according to a dosage ratio of 4.0 mol / L of the acidic base solution, and adding aluminum chloride according to a dosage ratio of 0.8 mol / L of the acidic base solution, and stirring to obtain a mixed iron-aluminum acid solution.

[0080] 2) Put 0.400 mm short fiber steel fiber powder into the aluminum-containing treatment solution, stir for 10 min in a constant temperature environment of 65°C, pass ammonia gas into the solution system to a pH value of 14 after surface treatment, then stand for 25 min, filter and dry to obtain modified steel fiber.

[0081] 3) 35wt% carbon black N330, 5wt% silane coupling agent KH-550, 2wt% sulfur, and the balance being natural rubber, after batching according to the above components, stirring for 15 min under the environmental conditions of a temperature of 110°C and a rotation speed of 60 rpm, then crushing to a mesh size of 1000 mesh to obtain steel wire glue.

[0082] 4) uniformly spray the steel wire glue on the surface of the modified steel fiber by electrostatic charge spraying method, the electrostatic spraying voltage is 80kV, the spraying distance is 30cm, the glue layer thickness is 120μm, after spraying, heat preservation for 5min in an environment with a temperature of 110°C to obtain functionalized fiber.

[0083] 5) Mix uniformly according to the mass ratio of natural rubber latex, peroxoacetic acid, carbon black N550 and nano white carbon black of 5:1.6:2.5:0.5, stir and mix under the environmental conditions of a temperature of 40°C and a pressure of 1.0MPa for 1h to obtain a composite glue.

[0084] 6) Put the functionalized fiber into the composite glue and control the environmental pressure to 0.05atm for negative pressure impregnation, then filter and place the material in a 80°C environment for continuous stirring and rolling at a rotation speed of 90rpm for 25min, then vulcanize at a temperature of 130°C and a pressure of 0.8Mpa for 10min to obtain a rubber tire reinforcing filler.

[0085] 7) Mix uniformly natural rubber, carbon black, zinc oxide, stearic acid, antioxidant 4020, accelerator NS and sulfur according to the mass ratio of 100:60:5;2;2:1.5:2 to prepare a coating material.

[0086] 8) The steel cord of the steel cord belt is coated with 1.5 mm of the rubber compound at a temperature of 100°C by a double-roller calender and vulcanized at a temperature of 160°C and a pressure of 25 MPa for 10 min to obtain the reinforced rubber tire, and the rubber tire reinforcing filler is added in an amount of 25 wt% of the rubber compound.

[0087] A control group is set for step 8) in the example, and only the steel cord density is changed, and the specific changes are as follows.

[0088] Table 5: Control table of different steel cord density settings in Example 3:

[0089] The rubber tire prepared in the example is subjected to performance detection, and the specific characterization results are as follows.

[0090] Axial (Y-axis) tensile strength detection: cut a dumbbell-shaped sample with a thickness of 2.0±0.2 mm along the steel cord direction, use a universal testing machine pneumatic clamp with an initial clamping distance of 50 mm, and record the maximum tensile force at a tensile rate of 500 mm / min. The strength of the blank group S1-1 is defined as 100%.

[0091] Transverse (X-axis) tensile strength detection: cut a dumbbell-shaped sample with a thickness of 2.0±0.2 mm along the direction perpendicular to the steel cord, use a universal testing machine pneumatic clamp with an initial clamping distance of 50 mm, and record the maximum tensile force at a tensile rate of 500 mm / min. The strength of the blank group S1-1 is defined as 100%.

[0092] Puncture resistance detection: cut the example material into a 100×100 mm square piece with a thickness of 2.0±0.1 mm, use a puncture tester with a conical needle with a tip diameter of 1.0 mm, penetrate the sample at a puncture rate of 50 mm / min, record the maximum force value during puncture, and take the average of 5 points. The strength of the blank group S1-1 is defined as 100%.

[0093] Table 6: Performance detection characterization results of Example 3:

[0094] Analyzing the characterization results in Table 6 above, compared with Example 2, Example 3 further improves the preparation process of the rubber tire reinforcing filler. By increasing the concentrations of industrial hydrochloric acid and industrial hydrofluoric acid, and increasing the amounts of ferric chloride and aluminum chloride, the reaction of the iron-aluminum mixed acid solution is more vigorous, generating more active iron-aluminum compounds, thereby further improving the performance of the modified steel fiber. At the same time, the formula of the steel cord rubber is also optimized, and the proportion of the amount of carbon black N330 and silane coupling agent KH-550 is increased, which not only improves the adhesion of the steel cord rubber, but also significantly enhances its wear resistance and anti-aging performance.

[0095] From the performance test results, the rubber tire prepared in Example 3 has a slight decrease in Y-axis tensile strength, but the X-axis tensile strength and puncture resistance are both improved. In particular, in terms of puncture resistance, the rubber tire of Example 3 exhibits better performance than Example 2, and is almost equivalent to the puncture resistance of the high-density steel cord of the control group.

[0096] Comparative Example 1: Based on Example 2, only the fiber filler is changed in this example, and the remaining steps are the same as Example 2. The specific settings are as follows.

[0097] Table 7: Process adjustment control table of Comparative Example 1:

[0098] The performance test method of the product of Comparative Example 1 is completely consistent with Example 1, and the characterization results are shown in the following table.

[0099] Table 8: Performance test characterization results comparison table of Comparative Example 1 and Example 2:

[0100] Analyzing the characterization results in the above Table 8, the use of nylon short fibers instead of steel fibers in the present application results in a significant deterioration of the performance of the composite system. From the perspective of material constitutive properties, the modulus of nylon short fibers is significantly lower than that of steel fibers in the present application. This fundamental difference leads to the inability of nylon fibers to form an effective load transfer path in the composite system. The modulus gradient between the fibers and the rubber matrix in D1-1 sample is too large and the compatibility is poor, while in Example 2, the steel fibers with special surface treatment form a transition zone of about 5-8 μm wide, and the modulus presents a gradient distribution. During the deformation of the rubber matrix, the nylon fibers bend and flex significantly due to insufficient stiffness, resulting in a significant reduction in stress transfer efficiency. This stiffness mismatch effect is directly reflected in the Y-axis tensile strength of D1-1, which is only 72% of the blank group, much lower than the 88% of Example 2, indicating that nylon short fibers cannot effectively cooperate with steel cord to bear axial load.

[0101] Only physical adsorption characteristics are observed on the surface of nylon fibers in D1-1, and similar chemical bonding structures cannot be formed. Example 2 forms an element interdiffusion zone of about 2.5 μm wide at the fiber-rubber interface, while the interface transition zone in D1-1 is less than 0.8 μm wide, indicating poor interface compatibility. The interface bonding strength of D1-1 is only 43% of that of Example 2. This significant difference in interface bonding strength is one of the fundamental reasons for the deterioration of the performance of the composite material, and the interface stress concentration is severe, and the risk of interface failure is significantly increased.

[0102] The stress transfer efficiency of nylon short fibers in the composite system is much lower than that of steel fibers, and early failure characteristics can occur, which will directly reflect on the X-axis tensile strength, D1-1 only reaches 66% of the blank group, indicating that the transverse reinforcement effect of steel fibers on the rubber matrix is significantly better than that of nylon fibers, and the nylon fibers are essentially unable to achieve X-axis reinforcement due to low modulus and poor compatibility, and even serious deterioration. In addition, due to the insufficient stiffness of nylon fibers, they cannot form an effective "bridging effect" in the composite system, resulting in a significant decrease in micro-crack propagation resistance, which is consistent with the poor wear resistance test results of D1-1. The wear volume of D1-1 is significantly higher than that of Example 2, and the wear surface roughness increases by about 42%, indicating that nylon short fibers cannot effectively improve the wear resistance of the rubber matrix.

[0103] Specific gravity analysis shows that although D1-1 has a slight increase in overall density due to the use of lower density nylon fibers, this is because nylon itself has good glue absorption capacity, but Example 2 is close to it, which also shows that the glue absorption capacity of the filler of the present application is excellent. In contrast, the experimental group of D1-1 still produces a significant lightweight effect, but this lightweight benefit is offset or even covered by the significant decline in performance. Based on the "performance / weight" index evaluation, the overall efficiency of D1-1 is only about 68% of that of Example 2, indicating that simply using low-density fibers cannot achieve true lightweight optimization.

[0104] Comparative Example 2: Based on Example 2, only the modified steel fiber filler is changed, and the remaining steps are the same as Example 2. The specific settings are as follows.

[0105] Table 9: Process adjustment control table of Comparative Example 2:

[0106] The performance test method of the product of Comparative Example 2 is completely consistent with that of Example 1, and the characterization results are shown in the following table.

[0107] Table 10: Performance test characterization results comparison table of Comparative Example 2 and Example 2:

[0108] Analyzing the above Table 10 characterization results, the original steel fiber without surface modification leads to significant performance degradation of the composite system, fully demonstrating the decisive role of interface chemical bonding and micro-morphology engineering in the reinforcement of the filler-matrix interface.

[0109] From the perspective of surface chemical properties, in Example 2, a covalent chemical bond network is formed between the surface metal matrix-silicon bridge bond-rubber molecular chain after the steel fiber is treated with acid and sprayed with a coupling agent. In contrast, D2-1 lacks chemical bonding sites with rubber molecular chains, and the interface chemical bonding is missing.

[0110] Micro-morphology characterization reveals the significant influence of surface modification on the structure of steel fiber surface. The surface roughness parameter of steel fiber in Example 2 reaches 380 nm, while that of the original steel fiber in D2-1 is only 42 nm, and the difference in surface morphology is nearly one order of magnitude. The acid-treated steel fiber surface forms a micro-nano scale pit structure with a depth of about 0.5-1.5 μm, which increases the effective specific surface area and forms mechanical anchoring points at the same time. In Example 2, the rubber molecular chains penetrate deeply into the fiber surface pits to form a finger-like interlocking structure; while in D2-1, the interface presents a clear flat interface, lacking mechanical interlocking effect. This micro-morphology difference explains the problem of insufficient rubber adhesion in D2-1 due to the smooth surface, which directly limits the interface contact area and adhesion strength. The significant difference in interface stress transfer efficiency is directly reflected in the macro-mechanical properties, i.e., the Y-axis tensile strength of D2-1 is only 68% of the blank group, which is significantly lower than the 88% of Example 2; the X-axis tensile strength decreases to 96%, which does not produce a strengthening effect and is lower than Example 2. It is particularly worth noting that in the puncture resistance test, the maximum puncture force of D2-1 decreases by about 18% compared with Example 2, and the puncture energy decreases by about 25%, which indicates that the interface bonding strength plays a decisive role in the mechanical properties of the composite material under complex stress state.

[0111] These interface characteristic defects collectively lead to significant degradation of the composite material in terms of axial strength, transverse strength, and puncture resistance. The results of this comparative experiment systematically verify the key role of surface engineering in steel fiber reinforced rubber composites, especially the synergistic effect between the micro-morphology modification produced by acid treatment and the chemical bonding network established by coupling agent spraying, providing a scientific basis for the interface design of high-performance tire composites.

[0112] Comparative Example 3: Based on Example 2, this example only modifies the reinforced rubber tire, and the remaining steps are the same as Example 2. The specific settings are as follows.

[0113] Table 11: Process adjustment control table of Comparative Example 3:

[0114] The performance test method of the product of Comparative Example 3 is completely consistent with that of Example 1, and the characterization results are shown in the following table.

[0115] Table 12: Performance test characterization results comparison table of Comparative Example 3 and Example 2:

[0116] Analyzing the characterization results in the above Table 12, the traditional carbon black filling system and the reinforcing filler system of the present application show fundamental differences in microstructure, mechanical reinforcement mechanism, anisotropy characteristics, and lightweight benefits, fully verifying the significant advantages of innovative filler technology in the design of tire composites.

[0117] The conventional carbon black N330 and the reinforcing filler of the present application have significant differences in geometric morphology and size. The carbon black N330 presents a typical spherical aggregate structure with a primary particle size of about 28-36 nm, while the reinforcing filler of the present application has a fibrous structure with a high aspect ratio >100, a diameter of about 15-25 μm, and a length of 2-5 mm. Such geometric structural differences determine that the two fillers have completely different reinforcing mechanisms in the composite system. In D3-1, the carbon black forms a network structure in the rubber matrix, a typical three-dimensional random distribution; while in Example 2, the filler of the present application presents obvious orientation, forming an ordered directional reinforcing structure. Such microstructural differences directly lead to the fact that the tensile strength in the Y-axis of D3-1 is only 75%, lower than 88% of Example 2; more significantly, the tensile strength in the X-axis drops to 88%, far lower than Example 2, fully exposing the fundamental limitations of the conventional carbon black filling in the transverse reinforcing ability.

[0118] In D3-1, the carbon black-rubber interface forms a bound rubber layer as the main mechanism of reinforcement; while in Example 2, the macroscopic continuous reinforcing network established by the filler of the present application relies on the stress transfer and load sharing mechanism to provide the reinforcing effect. The movement of the rubber molecular chain in D3-1 is less restricted by the carbon black, indicating that the latter has significantly enhanced the constraint ability of the polymer chain segment, and under high strain conditions, the carbon black network structure is prone to collapse, while the filler network of the present application can still maintain effective load transfer.

[0119] The specific gravity of D3-1 reaches 1.96, slightly lower than that of Example 2, and this difference is due to the fundamental difference between the two design strategies and the different absorption capacity after filling. The actual carbon filler filling forms several gaps and pores, further reducing the specific gravity. D3-1 adopts the traditional reinforcing scheme of "increasing the steel cord density + carbon black filling", which inevitably leads to an increase in the overall density due to the increase in the content of high-density steel wires; while Example 2 adopts the innovative design of "optimizing the distribution of steel cords + the synergistic reinforcement of the filler of the present application", which reduces the amount of steel wires while compensating or even surpassing the performance level of the traditional design through the transverse reinforcing effect of the filler of the present application.

[0120] Comparative Example 4: Based on Example 2, this example only cancels the pre-vulcanization step, and the other steps are the same as Example 2. The specific settings are as follows.

[0121] Table 13: Process adjustment control table of Comparative Example 4:

[0122] The performance test method of the product of Comparative Example 4 is completely consistent with that of Example 1, and partial performance characterization is carried out, and the characterization results are shown in the following table.

[0123] Table 14: Performance test characterization results comparison table of Comparative Example 4 and Example 2:

[0124] Analyzing the above Table 14 characterization results, the absence of pre-vulcanization process leads to a cascading effect of microstructure failure and macroscopic performance collapse in steel fiber reinforced rubber composites. At the molecular crosslinking network level, the absence of pre-vulcanization makes D4-1 sample fail to form the initial sulfur crosslinking structure. This stage is the key temperature window for the formation of C-S-S-C polysulfide bonds, and these initial crosslinking points construct a semi-cured gel network, which is crucial for fixing the glue liquid in the micro-pores. The lack of this pre-crosslinking structure leads to D4-1 sample showing abnormally high fluidity at the high temperature stage of final vulcanization, causing the glue liquid in the micro-pores to melt and overflow before being fully crosslinked, destroying the designed micro-anchoring structure. In terms of interface chemical bonding, the pre-vulcanization temperature interval is also the best temperature window for the hydrolysis-condensation reaction of silane coupling agent KH-550. At this temperature, the ethoxy group in KH-550 molecule is moderately hydrolyzed to form active silanol group (-Si-OH), which then reacts with the hydroxyl group on the Fe / Al oxide layer on the surface of steel fiber to form a stable Fe-O-Si covalent bond network. D4-1 directly enters the high temperature final vulcanization stage, resulting in partial thermal degradation of the coupling agent molecules before the reaction, and failing to form an effective interface chemical bonding structure, losing the molecular link between steel fiber and rubber matrix. Microstructure defects directly lead to systematic degradation of macroscopic mechanical properties. The Y / X axis tensile strength of D4-1 decreases by 14% / 19%, and this mechanical property degradation is due to a significant decrease in interface stress transfer efficiency. The puncture resistance of D4-1 decreases by 25% compared to Example 2, and the fracture analysis shows that this is closely related to the crack propagation path - in D4-1 lacking effective interface bonding, the crack mainly propagates rapidly along the interface region; while in Example 2, the effective interface bonding makes the crack propagation path more tortuous, increasing energy absorption. Durability evaluation also shows that the wear amount of D4-1 increases to 2.2 times that of Example 2, mainly due to the easy peeling wear between the glue layer and the fiber, losing the ability to resist wear together.

[0125] This example verifies the dual key role of pre-vulcanization in steel fiber reinforced rubber composites. On the one hand, the preliminary crosslinking network formed by pre-vulcanization effectively controls the fluidity of the glue liquid, prevents the glue liquid from overflowing at the high temperature stage of final vulcanization, and ensures the integrity of the micro-anchoring structure; on the other hand, pre-vulcanization provides the best temperature window for interface coupling reaction, promotes the formation of Fe-O-Si chemical bond network, and strengthens the interface bonding performance. The collapse of the full spectrum of properties of D4-1 provides reverse verification, confirming the irreplaceability of the multi-stage vulcanization process (pre-vulcanization + final vulcanization) emphasized in this invention for realizing the "microstructure design-chemical bonding-organic and inorganic synergy" three-in-one enhancement mechanism.

[0126] Comparative Example 5: Based on Example 2, this example only modifies the modified steel fiber process, and the rest of the steps are the same as Example 2. The specific settings are as follows.

[0127] Table 15: Process adjustment control table for Comparative Example 5:

[0128] The performance test method of the product of Comparative Example 5 is completely consistent with Example 1, and partial performance characterization is carried out, and the characterization results are shown in the following table.

[0129] Table 16: Performance test characterization result comparison table of Comparative Example 5 and Example 2:

[0130] Analyzing the above Table 16 characterization results, the surface micro-morphology characteristics have a decisive influence on the filler-rubber interface interaction and the overall performance of the composite. The D5-1 sample is prepared by a non-etching process, and the surface remains dense and smooth, lacking effective microporous structure, resulting in significant deterioration of interface performance and mechanical properties. The rubber absorption weight gain rate of D5-1 is only 0.2%, which is much lower than 3.8% of Example 2 (reduced by about 95%). This significant difference is directly due to the fundamental difference in micro-surface morphology. The surface of Example 2 forms a three-dimensional network-like microporous structure after etching treatment, and the specific surface area increases; while the surface of D5-1 remains relatively smooth, only with nanoscale roughness. This micro-morphology difference leads to a qualitative difference in the infiltration ability of the rubber precursor during the impregnation process, which is quantitatively manifested as a significant difference in rubber absorption weight gain rate. Interface bonding strength test reveals the key influence of surface microporous structure on interface bonding performance. The interface peeling strength of D5-1 is reduced by 67% compared with Example 2, firstly, the lack of microporous structure leads to the loss of mechanical anchoring effect, and the interface bonding mainly depends on the weak physical adsorption force; secondly, the interface bonding strength is proportional to the actual contact area, resulting in a significant reduction in effective contact area. This interface property difference directly transfers to the macroscopic mechanical properties, especially the transverse tensile strength. The X-axis tensile strength of D5-1 is only 89%, which is significantly lower than 112% of Example 2, indicating that there is a significant defect in the filler-rubber matrix synergy. It is worth noting that the specific gravity of D5-1 is slightly lower than that of Example 2, reduced by about 3%. This density difference is directly attributed to the difference in rubber absorption amount - the microporous structure in Example 2 absorbs more rubber, resulting in a slightly higher overall density. However, this slight weight advantage is far from making up for the significant performance decline, especially the 23% reduction in X-axis tensile strength. This trade-off relationship clearly shows that the "rubber absorption weight gain" caused by the microporous structure is the necessary cost for interface strengthening and performance improvement, which is a reasonable design trade-off.

[0131] This example verifies the core mechanism of the invention that "etching micro-porous structure can effectively improve the glue absorption capacity and specific gravity, and effectively improve the interface bonding performance". The research results show that in the design of steel fiber reinforced rubber composite material, the surface micro-porous structure is the key to build high-efficiency interface, and the lightweight target should be realized by optimizing the overall structure design and reducing the amount of steel wire cord, rather than sacrificing the interface bonding capacity of the filler.

Claims

1. A method for preparing a rubber tire reinforcing filler, characterized in that: The method comprises: 1) taking steel fiber powder and placing it in an aluminum-containing treatment solution, performing surface treatment, adjusting the solution system to alkalinity, and then aging to obtain modified steel fiber; 2) preparing steel wire glue, and using an electrostatic charge spraying method to evenly spray the steel wire glue on the surface of the modified steel fiber to obtain functionalized fiber; 3) preparing a composite glue, placing the functionalized fiber in the composite glue for negative pressure impregnation, and then filtering and performing rolling aging and pre-vulcanization to obtain a rubber tire reinforcement filler.

2. The method for preparing a rubber tire reinforcing filler according to claim 1, characterized in that: In step 1), the steel fiber powder is a short fiber powder of 0.300 to 0.400 mm; in step 1), the aluminum-containing treatment liquid is an iron-aluminum mixed acid liquid, which is prepared by the following method: first, industrial hydrochloric acid and industrial hydrofluoric acid are mixed with water to prepare an acidic base liquid, wherein the concentration of industrial hydrochloric acid in the acidic base liquid is 110 to 130 mL / L, and the concentration of industrial hydrofluoric acid is 10 to 20 mL / L, and then ferric chloride is added according to a dosage ratio of 3.0 to 4.0 mol / L of the acidic base liquid, and aluminum chloride is added according to a dosage ratio of 0.3 to 0.8 mol / L of the acidic base liquid, and the mixture is stirred and mixed evenly to obtain the iron-aluminum mixed acid liquid.

3. The method for preparing a rubber tire reinforcing filler according to claim 1 or 2, characterized in that: The surface treatment in step 1) is to place the steel fiber powder in an aluminum-containing treatment solution and stir it at a constant temperature of 55-65° C. for 10-15 minutes; the adjustment of the solution system to alkalinity in step 1) is to introduce ammonia gas into the solution system to a pH value ≥ 12, and then let it stand for 25-35 minutes, filter it, and dry it to obtain the modified steel fiber.

4. The method for preparing a rubber tire reinforcing filler according to claim 1, characterized in that: Step 2) The steel wire rubber component comprises 33-35 wt% carbon black N330, 3-5 wt% silane coupling agent KH-550, 1-2 wt% sulfur, and the balance natural rubber. After mixing the above components, the mixture is stirred at a temperature of 100-110° C. and a rotation speed of 40-60 rpm for 15-20 minutes, and then crushed to a mesh size of ≥800 to obtain the steel wire rubber.

5. The method for preparing a rubber tire reinforcing filler according to claim 1 or 4, characterized in that: Step 2) The control parameters of the electrostatic charge spraying method are: voltage 50-80 kV, spraying distance 20-30 cm, adhesive layer thickness 80-120 μm, and after spraying, the functionalized fiber is obtained by keeping the temperature at 90-110° C. for 5-8 minutes.

6. The method for preparing a rubber tire reinforcing filler according to claim 1, characterized in that: Step 3) The composite rubber is prepared by the following method: natural rubber latex, peracetic acid, carbon black N550 and nano-silica are uniformly mixed in a mass ratio of 5: (1.4-1.6): 2.5: (0.3-0.5), and stirred for 1-2 hours under environmental conditions of a temperature of 30-40° C. and a pressure of 0.5-1.0 MPa to obtain a composite rubber.

7. The method for preparing a rubber tire reinforcing filler according to claim 1 or 6, characterized in that: In step 3), the negative pressure impregnation process controls the ambient pressure to ≤0.1 atm; in step 3), the rolling aging process is to place the material at 70-80° C. and continuously stir and roll at a speed of 30-90 rpm for 25-35 minutes; in step 3), the pre-vulcanization process controls the temperature to 120-130° C., the pressure to 0.5-0.8 MPa, and the vulcanization time to 10-15 minutes.

8. A rubber tire reinforcing filler prepared by the method according to any one of claims 1 to 7.

9. The rubber tire reinforcing filler according to claim 8, characterized in that: The rubber tire reinforcing filler is used for filling the steel tire belt layer.

10. The rubber tire reinforcing filler according to claim 9, characterized in that: When the rubber tire reinforcing filler is used to fill the steel wire tire belt layer, it is added to the coating rubber and mixed evenly; the addition amount of the rubber tire reinforcing filler is 15-25wt% of the coating rubber, and the density of the steel cord is reduced by 30-50%.

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