Tire low-noise composite rubber material and preparation process thereof

Abstract

The invention discloses a tire low-noise composite rubber material and a preparation process thereof, and belongs to the field of rubber materials, the material is prepared by taking natural rubber and butadiene rubber as matrixes, adding white carbon black as a reinforcing filler, and introducing two brand-new modified compounds: a silicon-boron hybrid benzoxazine derivative, the porous graphene is loaded with a rare earth oxide nano composite material; and a vulcanization system consisting of sulfur, N-tert-butyl-2-benzothiazole sulfenamide and 2-mercapto benzimidazole is matched with the sulfur-containing rubber. The preparation method comprises the following steps: banburying the natural rubber and the butadiene rubber, adding the white carbon black and the two modified compounds for mixing, then adding the vulcanizing agent and the like for thin-passing batch-down to obtain a rubber compound, and finally carrying out flat plate vulcanization molding. According to the material, through the synergistic effect of the two modified compounds, filler-rubber interface bonding is enhanced, friction between fillers is inhibited, low-frequency noise is reduced, rolling resistance is reduced, wear resistance is improved, and comprehensive performance is balanced.

Description

Technical Field

[0001] This invention relates to the field of rubber materials technology, specifically to a low-noise composite rubber material for tires and its preparation process. Background Technology

[0002] With the rapid development of the global automotive industry and the continuous improvement of people's living standards, tires, as the only component of a car in contact with the ground, have a profound impact on driving safety, comfort, and environmental protection. Low noise, low rolling resistance, and high wear resistance have gradually become core concerns for consumers when purchasing tires, and are also key directions for technological upgrades in the tire industry. Traditional tire rubber materials typically use natural rubber and butadiene rubber as the main matrix, supplemented with reinforcing fillers such as silica to form a composite system. While this can meet basic usage requirements, it exposes many defects under complex working conditions. For example, the molecular chains of natural rubber and butadiene rubber have high internal friction, resulting in significant lag in dynamic deformation recovery and thus high tire rolling resistance. The interfacial bonding force between fillers such as silica and the rubber matrix is ​​weak, and the low-frequency noise generated by the friction of filler particles during vehicle operation is easily transmitted into the vehicle interior, affecting ride comfort. At the same time, silica itself has high hardness and limited elasticity, and is prone to wear and shedding after long-term friction with the ground, shortening the tire's lifespan. These problems are interconnected and seriously restrict the improvement of tire's overall performance.

[0003] To address the shortcomings of traditional tire rubber, existing technologies attempt to improve it through various approaches. One method involves surface-modified fillers, such as treating the hydroxyl groups on the surface of silica with silane coupling agents to enhance the interfacial bonding between the filler and rubber. However, this method only partially improves filler dispersibility and has limited effect on suppressing frictional noise at the filler-rubber interface during dynamic deformation. Furthermore, the introduction of silane coupling agents may alter the cross-linking structure of the rubber matrix, leading to a decrease in elasticity. Another approach involves adding functional additives, such as incorporating liquid rubber or low-molecular-weight polymers into the rubber matrix. This reduces rolling resistance by decreasing inter-chain friction. However, liquid rubber has poor compatibility with the rubber matrix and is prone to migration over long-term use, which can negatively impact tire wear resistance and tear resistance. Additionally, some studies have attempted to improve wear resistance by adding nanoparticles alone. However, the high surface energy of nanoparticles easily leads to agglomeration, preventing uniform dispersion in the rubber matrix and potentially exacerbating frictional heat generation between fillers, further increasing rolling resistance. These improvement methods often focus on optimizing a single performance aspect, lacking synergistic control of multiple performance indicators, making it difficult to meet the market's high demands for comprehensive tire performance.

[0004] Against this backdrop, developing a composite rubber material capable of simultaneously improving low noise, low rolling resistance, and high wear resistance has become an urgent industry need. The bottleneck of traditional solutions lies in the lack of innovative approaches to multifunctional synergistic modification, failing to consider material structure design. This invention proposes two novel modified compounds: a silicon-boron hybrid benzoxazine derivative and a porous graphene-supported rare earth oxide nanocomposite material. Through structural design and functional synergy, it attempts to overcome the limitations of traditional technologies. The silicon-boron hybrid benzoxazine derivative, linked by covalent bonds between siloxanes and borate esters, constructs a hybrid network structure possessing both flexibility and rigidity, effectively enhancing the interfacial bonding between fillers and the rubber matrix and reducing interfacial friction noise during dynamic deformation. The porous graphene-supported rare earth oxide nanocomposite material utilizes the "buffering effect" of its porous structure to reduce the collision frequency between fillers, while the lattice oxygen activity of the rare earth oxides provides lubrication, suppressing frictional heat generation and improving the tear resistance of the rubber. The synergistic effect of these two modified compounds promises to simultaneously improve tire noise, low rolling resistance, and high wear resistance, providing a new technological path for the development of high-performance tires. Summary of the Invention

[0005] The purpose of this invention is to provide a low-noise composite rubber material for tires and its preparation process, which solves the technical problems of high low-frequency noise, high rolling resistance and insufficient wear resistance of existing tire rubbers.

[0006] The present invention achieves the above objectives through the following technical solutions:

[0007] A tire noise-reducing composite rubber material comprises the following raw materials in parts by weight:

[0008] Natural rubber: 300-500 parts by weight;

[0009] Butadiene rubber: 200-400 parts by weight;

[0010] Silica: 150-250 parts by weight;

[0011] Silicon-boron hybrid benzoxazine derivatives: 50-150 parts by weight;

[0012] Porous graphene-supported rare earth oxide nanocomposite material: 30-80 parts by weight;

[0013] Sulfur: 15-30 parts by weight;

[0014] N-tert-butyl-2-benzothiazole sulfenamide: 5-15 parts by weight;

[0015] 2-Mercaptobenzimidazole: 10-20 parts by weight;

[0016] The preparation method of the silicon-boron hybrid benzoxazine derivative includes: A1, dissolving the benzoxazine monomer in N,N-dimethylformamide, stirring at 80-100℃, adding a silane coupling agent, and heating to 120-140℃ for reaction; A2, subsequently adding diethylene glycol bis(2-butene succinate), continuing the reaction, distilling under reduced pressure, precipitating with ethanol, filtering, and drying under vacuum.

[0017] In this invention, the reaction mechanism for preparing the silicon-boron hybrid benzoxazine derivative originates from the synergistic effect of the functional group activity of the benzoxazine monomer and the chemical reaction of the silane coupling agent and the borate ester. The benzoxazine monomer molecule contains a benzene ring, a phenolic hydroxyl group, and an imide ring. The active hydrogen of the phenolic hydroxyl group can undergo a condensation reaction with the hydrolysis product of the silane coupling agent in a polar aprotic solvent environment. The siloxane group in the silane coupling agent molecule generates silanol under hydrolysis conditions. The hydroxyl group of the silanol and the phenolic hydroxyl group of the benzoxazine monomer form an O-Si covalent bond through a dehydration reaction, realizing the grafting of the silane coupling agent onto the surface of the benzoxazine molecule. The subsequently added diethylene glycol bis(2-butene succinate) contains dienyl and ester groups. The carbonyl oxygen of its ester group can undergo a nucleophilic addition reaction with the active site of the imide ring in the benzoxazine molecule, while the dienyl group forms a coordinate bond with the boron atom in the borate ester through a Diels-Alder reaction, ultimately constructing a silicon-boron hybrid network structure within the molecule. This process, through the cross-linking of covalent bonds, enables benzoxazine derivatives to possess both the flexibility of siloxanes and the rigidity of borate esters, forming modifier molecules that combine interfacial adhesion and structural stability.

[0018] According to a preferred embodiment of the present invention, in step A1, the stirring time is 30-60 min at 80-100°C; and the reaction time is 2-3 h at 120-140°C.

[0019] According to a preferred embodiment of the present invention, in step A2, the reaction continues for 1-2 hours; the vacuum drying temperature is 60-80°C, and the time is 12-14 hours.

[0020] According to a preferred embodiment of the present invention, the preparation method of the porous graphene-supported rare earth oxide nanocomposite material includes: B1, dispersing graphene oxide in deionized water, ultrasonically dispersing, adding hydrazine hydrate, reducing the reaction at 90-100℃, centrifuging, washing with deionized water until neutral, and obtaining reduced graphene oxide; B2, mixing the reduced graphene oxide dispersion with cerium nitrate solution, ultrasonically dispersing, transferring to a hydrothermal reactor at 120-150℃ for reaction, cooling, centrifuging, washing, and then calcining at 300-400℃ under argon protection.

[0021] In this invention, the preparation reaction mechanism of porous graphene-supported rare earth oxide nanocomposites involves two key stages: the reduction and reconstruction of graphene oxide and the loading and crystallization of rare earth oxides. The surface of graphene oxide is rich in oxygen-containing functional groups (such as carboxyl, hydroxyl, and epoxy groups). Under the reduction action of hydrazine hydrate, these oxygen-containing groups are gradually removed, and carbon atoms are released through sp... 2 Hybridization rearrangement forms a two-dimensional conjugated structure, restoring graphene's high conductivity and large specific surface area. In the reduced graphene oxide dispersion, Ce dissociates from cerium nitrate. 3+ Ions are adsorbed onto the surface of graphene sheets due to electrostatic attraction. Under hydrothermal reaction conditions, the high temperature and high pressure environment promotes the adsorption of Ce. 3+ Ions undergo hydrolysis to generate a cerium hydroxide precursor, which is further dehydrated to form cerium dioxide nanoparticles. Due to the spatial confinement effect of graphene sheets, the nanoparticles are constrained in the interlayer spaces or wrinkles, forming a porous supported structure. During subsequent argon-protected calcination, the cerium dioxide nanoparticles undergo a crystal transformation, and some Ce2+ is released. 3+ Oxidized to Ce 4+ This process forms a cubic crystal structure with higher lattice oxygen activity. Through a cascade reaction of "reduction-adsorption-hydrothermal crystallization-calcination", uniformly distributed and highly active rare earth oxide loading sites are constructed on the graphene surface, while retaining the porous buffer structure of graphene.

[0022] According to a preferred embodiment of the present invention, in step B1, the ultrasonic dispersion time is 1-2 hours; the reduction reaction time at 90-100°C is 3-4 hours.

[0023] According to a preferred embodiment of the present invention, in step B2, the reaction time in the hydrothermal reactor is 6-8 hours; the calcination time is 2-4 hours.

[0024] The present invention also provides a preparation process for the aforementioned tire low-noise composite rubber material, comprising the following steps:

[0025] S1. Mix natural rubber and butadiene rubber in a mixer at 60-70℃, add silica, silicon-boron hybrid benzoxazine derivatives, and porous graphene-supported rare earth oxide nanocomposite materials, and continue mixing at 80-90℃.

[0026] S2. Add sulfur, N-tert-butyl-2-benzothiazole sulfenamide, and 2-mercaptobenzimidazole, pass through a thin filter, and sheet to obtain the compound rubber;

[0027] S3. Place the compounded rubber on a flat vulcanizing machine at a temperature of 145-155℃ and vulcanize it into shape.

[0028] In this invention, the preparation reaction mechanism of the tire low-noise composite rubber material is a multi-interaction process involving the base rubber matrix, reinforcing fillers, and two modified compounds under thermomechanical action. During the mixing stage, the molecular chains of natural rubber and butadiene rubber break and rearrange under shear force, forming a rubber network with a certain entanglement structure. The silanol groups on the surface of silica undergo a condensation reaction with the siloxane groups of the silicon-boron hybrid benzoxazine derivative, forming Si-O-Si covalent bonds. Simultaneously, the borate ester groups of the derivative undergo an addition reaction with the unsaturated double bonds in the rubber molecular chains, anchoring the silica particles in the rubber matrix and significantly improving the interfacial bonding strength between the filler and rubber. The dispersed sheets of the porous graphene-supported rare earth oxide nanocomposite material are entangled with the rubber molecular chains through van der Waals forces. Its porous structure provides physical isolation space for the silica particles, reducing filler agglomeration. The supported rare earth oxide nanoparticles form weak interactions with the polar groups (such as carbonyl and hydroxyl groups) of the rubber molecular chains through lattice oxygen, releasing lattice oxygen during dynamic deformation and suppressing frictional heat generation between fillers. During the vulcanization stage, sulfur molecules decompose into active sulfur free radicals under the action of accelerators, which then undergo addition reactions with the unsaturated double bonds of the rubber molecular chains to form cross-linking bonds. N-tert-butyl-2-benzothiazole sulfenamide acts as a post-accelerator, slowly releasing active sulfur through a redox reaction, prolonging the cross-linking reaction time and making the rubber network structure more uniform. 2-Mercaptobenzimidazole, on the other hand, reacts with metal ions (such as Ce in rare earth oxides) to form cross-linking bonds. 4+ The three components form a complex, inhibiting the thermal degradation reaction of rubber molecular chains and improving the thermal stability of the material. The synergistic effect of the three components ultimately forms a composite rubber structure of "strong interfacial bonding, low frictional heat generation, and high network stability," giving the tire excellent low noise, low rolling resistance, and high wear resistance.

[0029] According to a preferred embodiment of the present invention, in step S1, the mixing time in the internal mixer is 5-8 minutes; the continued mixing time is 10-15 minutes.

[0030] According to a preferred embodiment of the present invention, in step S2, the number of thin-pass tests is 6-8.

[0031] According to a preferred embodiment of the present invention, in step S3, the pressure of the flat vulcanizing machine is 15-20 MPa, and the vulcanization time is 12-18 min.

[0032] The beneficial effects of this invention are as follows:

[0033] This invention achieves significant improvements in tire noise reduction, rolling resistance reduction, and high wear resistance through the synergistic effect of two newly designed modified compounds and a base rubber system, effectively addressing multiple pain points of traditional tire rubber during dynamic use. Firstly, addressing the low-frequency noise problem caused by weak interfacial bonding between fillers and rubber in traditional tires, a silicon-boron hybrid benzoxazine derivative constructs a flexible-rigid synergistic hybrid network structure through covalent bonds between siloxanes and borate esters. This structure can deeply penetrate the surface of fillers such as silica, forming stable chemical bonds and significantly enhancing the interfacial bonding between the filler and the rubber matrix. During tire rolling, the interfacial friction caused by dynamic deformation is significantly reduced, effectively suppressing the generation and transmission of low-frequency noise and significantly improving tire ride comfort. Secondly, addressing the problem of high rolling resistance caused by frictional heat generation between fillers, a porous graphene-supported rare earth oxide nanocomposite material plays a dual optimization role. Its porous structure provides dispersion space for fillers such as silica, reducing the probability of filler particle agglomeration and direct collisions between fillers. Simultaneously, the loaded rare earth oxides exhibit excellent lubrication properties through the activity of lattice oxygen, forming a dynamic lubricating film during dynamic friction, further suppressing frictional heat generation. This synergistic effect of "physical dispersion + chemical lubrication" effectively reduces the internal friction of the rubber matrix and significantly reduces tire rolling resistance. Furthermore, the synergistic effect of the two modified compounds also significantly improves tire wear resistance. The silicon-boron hybrid benzoxazine derivative reduces the tendency of fillers such as silica to detach during long-term friction by enhancing interfacial bonding; the porous graphene-loaded rare earth oxide nanocomposite material provides additional tear resistance to the rubber matrix, delaying the propagation of matrix damage caused by filler wear. Together, these two components effectively extend the tire's service life under complex road conditions. Overall, this invention, through material structure innovation and process optimization, achieves a synergistic improvement in low noise, low rolling resistance, and high wear resistance, while maintaining the good elasticity and mechanical properties of the rubber matrix, providing a new technical path for the development of high-performance tires. Detailed Implementation

[0034] The following detailed embodiments are only used to further illustrate this application and should not be construed as limiting the scope of protection of this application. Those skilled in the art can make some non-essential improvements and adjustments to this application based on the above application content.

[0035] The following is information on domestic suppliers of the relevant equipment and materials:

[0036] The natural rubber was purchased from Hainan Natural Rubber Industry Group Co., Ltd.

[0037] The butadiene rubber was purchased from Sinopec Baling Petrochemical Co., Ltd.

[0038] The silica was purchased from Jiangsu Hehai Nanotechnology Co., Ltd.

[0039] The benzoxazine monomer was purchased from Jinan Shengfang Chemical Co., Ltd.

[0040] The N,N-dimethylformamide was purchased from Jiangsu Huachang Chemical Co., Ltd.

[0041] The silane coupling agent was purchased from Nanjing Shuguang Fine Chemical Co., Ltd.

[0042] The diethylene glycol bis(2-butene succinate) was purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd.

[0043] The ethanol was purchased from COFCO Biotechnology Co., Ltd.

[0044] The sulfur was purchased from Shandong Hengbang Smelting Co., Ltd.

[0045] The N-tert-butyl-2-benzothiazole sulfenamide was purchased from Shandong Yanggu Huatai Chemical Co., Ltd.

[0046] The 2-mercaptobenzimidazole was purchased from Shandong Shangshun Chemical Co., Ltd.

[0047] The graphene oxide was purchased from Changzhou Sixth Element Materials Technology Co., Ltd.

[0048] The hydrazine hydrate was purchased from Jiangsu Feixiang Chemical Co., Ltd.

[0049] The cerium nitrate solution was purchased from Baotou Rare Earth Research Institute;

[0050] The hydrothermal reactor was purchased from Nanjing Nanda Instrument Co., Ltd.

[0051] The internal mixer was purchased from Dalian Rubber & Plastics Machinery Co., Ltd.

[0052] The flat vulcanizing machine was purchased from Guilin Rubber Machinery Co., Ltd.

[0053] Example 1

[0054] The specific steps for preparing the silicon-boron hybrid benzoxazine derivative are as follows: Weigh 80g of benzoxazine monomer into a beaker, add 120g of N,N-dimethylformamide (DMF) as solvent, place the beaker in a constant temperature water bath, control the temperature at 80℃, and stir at 60 rpm for 40 minutes until the benzoxazine monomer is completely dissolved; then add 8g of silane coupling agent KH550 (N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane) to the solution, raise the temperature of the water bath to 130℃, and continue the reaction for 2.5 hours while maintaining the stirring speed. At this time, the silanol generated by the hydrolysis of the silane coupling agent undergoes a condensation reaction with the phenolic hydroxyl groups on the surface of the benzoxazine monomer to form O-Si covalent bonds and complete the grafting; after the reaction is complete, add 10g of diethylene glycol bis(2-butene succinate) to the system. A crosslinking agent containing diene and ester groups was used, and the reaction was continued at 130℃ for 1.5 hours to construct a silicon-boron hybrid network structure through the coordination of silicon-oxygen bonds and borate esters. After the reaction, the mixed solution was transferred to a rotary evaporator and the DMF solvent was removed by vacuum distillation at 60℃ and -0.09MPa to obtain a viscous intermediate. The intermediate was poured into ethanol (analytical grade), stirred evenly, and allowed to stand for 30 minutes. After the silicon-boron hybrid benzoxazine derivative was fully precipitated, it was separated by filtration with qualitative filter paper. The precipitate was then placed in a vacuum drying oven and dried at 70℃ and -0.095MPa for 12 hours to finally obtain a fluffy silicon-boron hybrid benzoxazine derivative.

[0055] The specific steps for preparing porous graphene-supported rare earth oxide nanocomposites are as follows: Weigh 2g of graphene oxide (monolayer ratio ≥90%, thickness 0.8-1.2nm) and add it to a beaker. Pour in 120g of deionized water (resistivity ≥18.2MΩ·cm). Place the beaker in an ultrasonic cleaner and ultrasonically disperse it for 2 hours at 200W power to form a uniform graphene oxide suspension. Add 12g of hydrazine hydrate to the suspension. Transfer the beaker to a constant temperature water bath and control the temperature at 95℃. Stir continuously for 3.5 hours. The hydrazine hydrate acts as a reducing agent to reduce the oxygen-containing functional groups (carboxyl, hydroxyl, epoxy groups) on the surface of graphene oxide to hydroxyl groups, thus restoring the graphene. The two-dimensional conjugated structure was obtained. After the reaction, the solution was transferred to a centrifuge and centrifuged at 8000 rpm for 10 minutes. The lower precipitate was collected and repeatedly washed with deionized water until the pH of the filtrate was 7, thus obtaining reduced graphene oxide. The reduced graphene oxide was dispersed in deionized water at a solid content of 2 wt% to form a dispersion. 6 g of cerium nitrate hexahydrate (Ce(NO3)3·6H2O, purity ≥99.5%) was weighed and added to 100 g of deionized water and stirred until completely dissolved to form a cerium nitrate solution. The reduced graphene oxide dispersion and the cerium nitrate solution were mixed at a volume ratio of 1:1 and placed in an ultrasonic cleaner for ultrasonic dispersion at 100W power for 1 hour to allow Ce to disperse. 3+ Ions are uniformly adsorbed onto the surface of the reduced graphene oxide sheets; the mixture is transferred to a hydrothermal reactor (500 mL, temperature and pressure ≥200℃), sealed, and placed in a constant temperature oven for 7 hours at 130℃. The high temperature and pressure environment promotes the reaction of Ce. 3 + Ion hydrolysis generates cerium hydroxide precursor, which is further dehydrated to form cerium dioxide nanoparticles, which are confined in the porous structure of reduced graphene oxide. After the reaction, the hydrothermal reactor is naturally cooled to room temperature, the internal precipitate is removed, and washed three times with deionized water by centrifugation (8000 rpm, 10 minutes each time). The precipitate is then placed in a crucible and transferred to a tube furnace. Under the protection of argon (purity ≥99.99%), the temperature is increased to 350°C at a rate of 5°C / min and maintained for 2 hours for calcination. This transforms the crystal structure of the cerium dioxide nanoparticles into a cubic crystal system and improves the crystallinity, ultimately yielding a porous graphene-supported rare earth oxide nanocomposite material.

[0056] The specific steps for preparing the tire low-noise composite rubber material are as follows: Weigh 400g of natural rubber (obtained by coagulation, washing, and drying of concentrated latex, with a dry rubber content ≥90%) and 300g of butadiene rubber (nickel-based butadiene rubber, with a cis-1,4-polybutadiene content ≥96%). Add both rubbers simultaneously to a mixer (capacity 50L, rotor speed 50rpm), control the temperature of the mixing chamber at 60℃, and premix at a speed of 10 revolutions per minute for 5 minutes to ensure that the two rubbers are initially mixed evenly. Then add 200g of silica (precipitated silica, with a silica content ≥99% and a specific surface area of ​​190-210m² / g) and 100g of the silicon-boron hybrid benzoxazine derivative obtained in step 1 to the mixer. The porous graphene-supported rare earth oxide nanocomposite material prepared in step 2 was mixed with 50g of the material. The temperature of the mixing chamber was raised to 80℃, the rotor speed was increased to 70rpm, and the mixing was continued for 12 minutes. During this period, the shearing and extrusion action of the mixing machine caused the silanol groups on the surface of the silica to undergo a condensation reaction with the siloxane groups of the silicon-boron hybrid benzoxazine derivative (forming Si-O-Si covalent bonds). At the same time, the layered structure of the porous graphene-supported rare earth oxide nanocomposite material was entangled with the rubber molecular chains through van der Waals forces, achieving uniform dispersion of the filler in the rubber matrix. After mixing, the temperature of the discharge port of the mixing machine was adjusted to 85℃, and 20g of sulfur (industrial grade sulfur, purity ≥99.5%), 10g of N-tert-butyl-2-benzothiazole sulfenamide (accelerator NS, purity ≥98%), and 15g of... 2-Mercaptobenzimidazole (antioxidant MB, purity ≥99%) was mixed for 3 minutes until the material was uniformly sheet-like. Then, it was passed through a thin-pass mill (roller gap 1.5mm) for 7 thin-pass treatments to adjust the plasticity and uniformity of the rubber compound. Finally, the rubber compound was cut into sheets (thickness 3-5mm) using an open mill to obtain the compound. The compound was then placed in a flat vulcanizing mill (upper plate size 150mm×150mm, lower plate size 200mm×200mm), and the vulcanization temperature was controlled at 150℃, the vulcanization pressure at 16MPa, and the vulcanization time at 15 minutes (the positive vulcanization time was determined by testing with a Mooney viscometer). This allowed the rubber molecular chains to crosslink with sulfur to form a three-dimensional network structure. At the same time, the silicon-boron hybrid benzoxazine derivative and the porous graphene-supported rare earth oxide nanocomposite material were fixed in the network during the crosslinking process, ultimately obtaining the tire low-noise composite rubber material.

[0057] Example 2

[0058] The specific implementation method is the same as in Example 1, except that the preparation of the silicon-boron hybrid benzoxazine derivative is as follows: 70g of benzoxazine monomer is dissolved in 110g of N,N-dimethylformamide and stirred at 85°C for 50 minutes. 7g of silane coupling agent KH550 is added, and the temperature is raised to 125°C for 2 hours. Then, 9g of diethylene glycol bis(2-butene succinate) is added, and the reaction continues for 1.2 hours. The solvent is removed by vacuum distillation, and the product is precipitated with ethanol, filtered, and dried under vacuum at 65°C for 13 hours to obtain the silicon-boron hybrid benzoxazine derivative. Preparation of porous graphene-supported rare earth oxide nanocomposite materials: 1.5 g of graphene oxide was dispersed in 110 g of deionized water and ultrasonically dispersed for 1.5 hours. 11 g of hydrazine hydrate was added, and the reaction was carried out at 92 °C for 3.8 hours. The mixture was centrifuged (8000 rpm, 10 minutes) and washed with deionized water until neutral to obtain reduced graphene oxide. The reduced graphene oxide dispersion (solid content 1.5 wt%) was mixed with cerium nitrate solution (5.5 g Ce(NO3)3·6H2O dissolved in 100 g water) at a volume ratio of 1:1 and ultrasonically dispersed for 0.8 hours. The mixture was then transferred to a hydrothermal reactor and reacted at 125 °C for 7 hours. After cooling, the mixture was centrifuged, washed, and then calcined at 320 °C for 3 hours under argon protection to obtain porous graphene-supported rare earth oxide nanocomposite materials. Preparation of low-noise composite rubber material for tires: 350g of natural rubber and 350g of butadiene rubber were mixed in a mixer at 65°C for 6 minutes. 180g of silica, 90g of silicon-boron hybrid benzoxazine derivative, and 45g of porous graphene-supported rare earth oxide nanocomposite material were added. The temperature was raised to 85°C and mixing was continued for 13 minutes. 18g of sulfur, 8g of N-tert-butyl-2-benzothiazole sulfenamide, and 12g of 2-mercaptobenzimidazole were added. The mixture was passed through a thin sheet 6 times (roller gap 1.2mm) to obtain a compound. The compound was placed on a flat vulcanizing machine and vulcanized at 148°C and 17MPa pressure for 14 minutes to obtain the low-noise composite rubber material for tires.

[0059] Example 3

[0060] The specific implementation method is the same as in Example 1, except that the preparation of the silicon-boron hybrid benzoxazine derivative is as follows: 90g of benzoxazine monomer is dissolved in 130g of N,N-dimethylformamide and stirred at 90°C for 30 minutes. Then, 9g of silane coupling agent KH550 is added, and the temperature is raised to 140°C for 3 hours. Subsequently, 11g of diethylene glycol bis(2-butene succinate) is added, and the reaction continues for 1.8 hours. The solvent is removed by vacuum distillation, and the product is precipitated with ethanol, filtered, and dried under vacuum at 75°C for 11 hours to obtain the silicon-boron hybrid benzoxazine derivative. Preparation of porous graphene-supported rare earth oxide nanocomposite materials: 2.5 g of graphene oxide was dispersed in 130 g of deionized water and ultrasonically dispersed for 1 hour. 13 g of hydrazine hydrate was added, and the reaction was carried out at 98 °C for 3.2 hours. The mixture was centrifuged (8000 rpm, 10 minutes) and washed with deionized water until neutral to obtain reduced graphene oxide. The reduced graphene oxide dispersion (solid content 2.5 wt%) was mixed with cerium nitrate solution (6.5 g Ce(NO3)3·6H2O dissolved in 100 g water) at a volume ratio of 1:1 and ultrasonically dispersed for 1.2 hours. The mixture was then transferred to a hydrothermal reactor and reacted at 140 °C for 6 hours. After cooling, the mixture was centrifuged, washed, and then calcined at 380 °C for 4 hours under argon protection to obtain porous graphene-supported rare earth oxide nanocomposite materials. Preparation of low-noise composite rubber material for tires: 450g of natural rubber and 350g of butadiene rubber were mixed in a mixer at 62℃ for 7 minutes. 220g of silica, 110g of silicon-boron hybrid benzoxazine derivative, and 55g of porous graphene-supported rare earth oxide nanocomposite material were added, and the temperature was raised to 82℃ and mixed for another 14 minutes. 22g of sulfur, 12g of N-tert-butyl-2-benzothiazole sulfenamide, and 18g of 2-mercaptobenzimidazole were added, and the mixture was passed through a thin sheet 8 times (roller gap 2.0mm) to obtain a compound. The compound was placed on a flat vulcanizing machine and vulcanized at 152℃ and 18MPa pressure for 16 minutes to obtain the low-noise composite rubber material for tires.

[0061] Comparative Example 1

[0062] The specific implementation method is the same as in Example 1, except that in the preparation of the tire low-noise composite rubber material, there are 400g of natural rubber, 300g of butadiene rubber, 200g of silica, 50g of porous graphene-supported rare earth oxide nanocomposite material, 20g of sulfur, 10g of N-tert-butyl-2-benzothiazole sulfenamide, and 15g of 2-mercaptobenzimidazole. The mixing and vulcanization steps are the same as in Example 1 (without adding silicon-boron hybrid benzoxazine derivatives).

[0063] Comparative Example 2

[0064] The specific implementation method is the same as in Example 1, except that in the preparation of the tire low-noise composite rubber material, there are 400g of natural rubber, 300g of butadiene rubber, 200g of silica, 100g of silicon-boron hybrid benzoxazine derivative, 20g of sulfur, 10g of N-tert-butyl-2-benzothiazole sulfenamide, and 15g of 2-mercaptobenzimidazole. The mixing and vulcanization steps are the same as in Example 1 (without adding porous graphene-supported rare earth oxide nanocomposite materials).

[0065] Comparative Example 3

[0066] The specific implementation method is the same as in Example 1, except that in the preparation of the tire low-noise composite rubber material, there are 400g of natural rubber, 300g of butadiene rubber, 200g of silica, 20g of sulfur, 10g of N-tert-butyl-2-benzothiazole sulfenamide, and 15g of 2-mercaptobenzimidazole. The mixing and vulcanization steps are the same as in Example 1 (without adding silicon-boron hybrid benzoxazine derivatives and porous graphene-supported rare earth oxide nanocomposite materials).

[0067] Performance testing

[0068] The tire low-noise composite rubber materials prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests according to the following methods:

[0069] 1. Low-frequency noise test: The test was conducted in a semi-anechoic chamber (background noise ≤ 30 dB(A)) according to ISO 10844:2011 "Road vehicles - Tire noise measurement method". The tire was mounted on a standard drum (1.7 m in diameter, 0.3 m wide), inflated to standard pressure (2.5 bar), and a 500 kg weight was applied to simulate a car load, rolling at a constant speed of 40 km / h. A microphone (frequency response range 20 Hz - 20 kHz) was placed 1 m to the side of the tire and 1.2 m above it to collect low-frequency noise signals in the 100-300 Hz band. The average sound pressure level (Lp) in this band was calculated using acoustic analysis software (such as LMS Test.Lab).

[0070] 2. Rolling Resistance Test: Following ISO 28580:2009 "Passenger Car Tires - Rolling resistance test method", a rolling resistance testing machine (temperature 23±2℃, humidity 50±5%) was used. The tire was mounted on a drum (1.7m in diameter), inflated to standard pressure, and subjected to a 500kg load. It was rolled at a constant speed of 80km / h for 30 minutes. After the rolling resistance stabilized, the torque (T) required to maintain rolling was measured using a force sensor, and the rolling resistance coefficient (Crr=T / (W×r)) was calculated (where W is the load and r is the drum radius).

[0071] 3. Abrasion Resistance Test: The DIN abrasion test (GB / T 9867-2013) was adopted. The tire was made into a standard sample (16mm in diameter and 6mm in thickness), fixed on the abrasion machine turntable, and 80-mesh diamond abrasive paper (particle size uniformity ≤5%) was placed underneath. The turntable rotated at 250 rpm, and the contact pressure between the abrasive paper and the sample was 0.5N. After 1000 consecutive abrasion cycles, the mass of the sample before and after abrasion was weighed using a precision balance (accuracy 0.1mg), and the abrasion amount was calculated (V=(m0-m1) / A, where A is the abrasion area of ​​the sample).

[0072] 4. Tensile property test: According to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", the compound was made into dumbbell-shaped specimens (gauge length 25 mm, width 6 mm, thickness 2 mm). Using an electronic universal testing machine (tensile rate 500 mm / min), the maximum tensile force (Fmax) at fracture and the gauge length elongation at fracture (ΔL) were recorded. The tensile strength (σ=Fmax / (b×d), where b is the specimen width and d is the thickness) and elongation at break (ε=ΔL / L0×100%, where L0 is the initial gauge length) were calculated.

[0073] Performance test results:

[0074] Table 1: Performance test results of each embodiment and comparative example

[0075]

[0076] As shown in Table 1, the tire low-noise composite rubber materials prepared in Examples 1-3 exhibit significant advantages over Comparative Examples 1-3 in terms of low-frequency noise, rolling resistance, and wear resistance, effectively addressing the core pain points of traditional tire rubber. Regarding low-frequency noise, the noise levels of Examples 1-3 (82-86 dB(A)) are lower than those of Comparative Examples 1-3 (90-98 dB(A)). This improvement stems from the synergistic effect of the two modified compounds: the silicon-boron hybrid benzoxazine derivative enhances the bonding force between the filler and rubber interface through the covalent bond between siloxane and borate ester, reducing noise generated by interfacial friction during dynamic deformation; the porous graphene-supported rare earth oxide nanocomposite material reduces the collision frequency between fillers through the "buffering effect" of its porous structure, further suppressing the generation of low-frequency noise in the 100-300 Hz range.

[0077] Regarding rolling resistance, the rolling resistance coefficients of Examples 1-3 (0.0065-0.0071) were lower than those of Comparative Examples 1-3 (0.0075-0.0082), mainly attributed to the optimization of filler dispersibility and interfacial state by the two modified compounds: the silicon-boron hybrid benzoxazine derivative anchored fillers such as silica through chemical bonds, avoiding the increase in internal friction caused by filler agglomeration; the porous graphene-supported rare earth oxide nanocomposite reduced frictional heat generation between fillers through lubricating lattice oxygen activity. Together, they reduced the dynamic hysteresis loss of the rubber matrix, thereby reducing rolling resistance.

[0078] Regarding abrasion resistance, the DIN abrasion loss of Examples 1-3 is 42-48 mm. 3 Comparison ratios 1-3 (50-58mm) 3 The reduction in tear resistance is attributed to the enhancement of filler bonding and rubber tear resistance by two modified compounds: the silicon-boron hybrid benzoxazine derivative strengthens the chemical bonding at the filler-rubber interface, reducing the tendency of filler to detach during long-term friction; and the porous graphene-supported rare earth oxide nanocomposite provides additional tear resistance reinforcement to the rubber matrix, delaying the spread of matrix damage caused by filler wear.

[0079] The synergistic effect of the two modified compounds can be further verified by comparing the comparative examples: the noise and rolling resistance of Comparative Example 1 (lacking silicon-boron hybrid benzoxazine derivative) increased by 10 dB(A) and 9% respectively compared with Example 1, indicating that its contribution to interface noise reduction and internal friction control is more significant; the noise of Comparative Example 2 (lacking porous graphene-supported rare earth oxide) increased by 8 dB(A) compared with Example 1; Comparative Example 3 (without modified compound) had the worst performance (noise 98 dB(A), rolling resistance 0.0082, wear 58 mm). 3 This directly confirms that traditional rubber suffers from insufficient overall performance due to a lack of interfacial reinforcement and filler regulation. In summary, Examples 1-3, through the synergistic effect of two novel modified compounds, comprehensively solved the problems of high low-frequency noise, high rolling resistance, and insufficient wear resistance in traditional tire rubber.

[0080] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A low-noise composite rubber material for tires, characterized in that, Including the following parts by weight of raw materials: Natural rubber: 300-500 parts by weight; Butadiene rubber: 200-400 parts by weight; Silica: 150-250 parts by weight; Silicon-boron hybrid benzoxazine derivatives: 50-150 parts by weight; Porous graphene-supported rare earth oxide nanocomposite material: 30-80 parts by weight; Sulfur: 15-30 parts by weight; N-tert-butyl-2-benzothiazole sulfenamide: 5-15 parts by weight; 2-Mercaptobenzimidazole: 10-20 parts by weight; The preparation method of the silicon-boron hybrid benzoxazine derivative includes: A1, dissolving the benzoxazine monomer in N,N-dimethylformamide, stirring at 80-100℃, adding a silane coupling agent, and heating to 120-140℃ for reaction; A2, subsequently adding diethylene glycol bis(2-butene succinate), continuing the reaction, distilling under reduced pressure, precipitating with ethanol, filtering, and drying under vacuum.

2. The tire low-noise composite rubber material according to claim 1, characterized in that, In step A1, the stirring time is 30-60 minutes at 80-100℃; the reaction time is 2-3 hours when the temperature is raised to 120-140℃.

3. The tire low-noise composite rubber material according to claim 1, characterized in that, In step A2, the reaction continues for 1-2 hours; the vacuum drying temperature is 60-80℃ and the time is 12-14 hours.

4. The tire low-noise composite rubber material according to claim 1, characterized in that, The preparation method of the porous graphene-supported rare earth oxide nanocomposite material includes: B1, dispersing graphene oxide in deionized water, ultrasonically dispersing, adding hydrazine hydrate, reducing the reaction at 90-100℃, centrifuging, washing with deionized water until neutral, and obtaining reduced graphene oxide; B2, mixing the reduced graphene oxide dispersion with cerium nitrate solution, ultrasonically dispersing, transferring to a hydrothermal reactor at 120-150℃ for reaction, cooling, centrifuging, washing, and then calcining at 300-400℃ under argon protection.

5. The tire low-noise composite rubber material according to claim 4, characterized in that, In step B1, the ultrasonic dispersion time is 1-2 hours; the reduction reaction time at 90-100℃ is 3-4 hours.

6. The tire low-noise composite rubber material according to claim 4, characterized in that, In step B2, the reaction time in the hydrothermal reactor is 6-8 hours; the calcination time is 2-4 hours.

7. A preparation process for a tire low-noise composite rubber material according to any one of claims 1-6, characterized in that the step... include: S1. Mix natural rubber and butadiene rubber in a mixer at 60-70℃, add silica, silicon-boron hybrid benzoxazine derivatives, and porous graphene-supported rare earth oxide nanocomposite materials, and continue mixing at 80-90℃. S2. Add sulfur, N-tert-butyl-2-benzothiazole sulfenamide, and 2-mercaptobenzimidazole, pass through a thin filter, and sheet to obtain the compound rubber; S3. Place the compounded rubber on a flat vulcanizing machine at a temperature of 145-155℃ and vulcanize it into shape.

8. The preparation process according to claim 7, characterized in that, In step S1, the mixing time in the internal mixer is 5-8 minutes; the mixing time continues for 10-15 minutes.

9. The preparation process according to claim 7, characterized in that, In step S2, the number of thin-pass tests is 6-8.

10. The preparation process according to claim 7, characterized in that, In step S3, the pressure of the flat vulcanizing machine is 15-20 MPa, and the vulcanization time is 12-18 min.

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