A tread rubber composition, a method for preparing a rubber compound thereof, and use in the tread of an aircraft tire

Abstract

The application belongs to the technical field of high polymer materials, and particularly relates to a tread rubber composition, a preparation method of a mixed rubber thereof and application of the tread rubber in an aviation tire tread. The tread rubber composition provided by the application comprises 100 parts of natural rubber, 40-53 parts of carbon black, 2-6 parts of liquid butadiene rubber, 1-3 parts of anti-crack resin, 1-6 parts of titanium dioxide, 2-4 parts of silane coupling agent, 1-4 parts of heat stabilizer, 0.5-2.5 parts of anti-reversion agent, 1-4 parts of nano zinc oxide, 1-3 parts of stearic acid, 1-4 parts of antioxidant, 0.5-2 parts of light stabilizer, 1-3 parts of protective wax, 0.5-3 parts of mildew-resistant antibacterial agent, 1.5-2.5 parts of insoluble sulfur and 1.2-2.2 parts of sulfenamide accelerator. The tread rubber composition provided by the application has good anti-solar radiation, mildew resistance, wear resistance, heat stability and mechanical properties, and can meet the take-off and landing sliding working conditions of the tire under large load, high speed and large impact.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a tread rubber compound composition and its preparation method and application in aircraft tire treads. Background Technology

[0002] The tread is a critical component of aircraft tires that directly contacts the ground, enduring the most demanding external stresses during takeoff, landing, and taxiing. Aircraft tires operate at high speeds, generating significant centrifugal force through high-speed rotation, while high-frequency deformation leads to substantial heat generation. This necessitates high tensile strength, tensile stress at a given elongation, tear strength, and excellent wear resistance, heat resistance, flexural strength, and cut resistance in the tread compound. Aircraft tires used in extreme marine environments face even more stringent conditions: they must withstand heavy loads, high taxiing and takeoff speeds, and are constantly exposed to strong solar radiation, high temperatures, high humidity, and high salt spray. These factors accelerate rubber aging, reduce strength, and eventually cause embrittlement. Furthermore, mold easily grows on the rubber surface. While mold does not directly corrode the rubber itself, it damages the tire's appearance, accelerates rubber aging, and poses hygiene and safety hazards.

[0003] Existing technologies include research on aircraft tire tread compounds designed for marine environments. For example, related technologies disclose an aircraft tire tread compound formulation adapted to marine environments, using natural rubber as the main material, combined with styrene-butadiene rubber, crack inhibitors, heat stabilizers, new-process high-structure, high-abrasion-resistant carbon black, silica, silane coupling agents, p-phenylenediamine antioxidants, and ketone-amine antioxidants, etc., aiming to give the compound resistance to ultraviolet radiation, ozone, atmospheric aging, salt spray, and mold attack, as well as good overall performance.

[0004] However, the existing technologies still have the following shortcomings: In terms of solar radiation resistance, they mainly rely on traditional antioxidant systems, resulting in limited radiation resistance efficiency; in terms of mildew resistance, they rely solely on the inertness of the rubber itself or the incidental effect of antioxidants; and in terms of low-temperature resistance, traditional formulations use softeners such as aromatic oils, which have high glass transition temperatures, leading to poor low-temperature brittleness of the rubber compound. Furthermore, existing technologies mostly use ordinary high-abrasion-resistant carbon black or silica in their reinforcing systems, and the synergistic effect of abrasion resistance and solar radiation resistance needs improvement. Therefore, existing aircraft tire tread compounds cannot fully meet the comprehensive requirements of high load, high speed, high-impact takeoff and landing, and long-term radiation resistance, mildew resistance, and low-temperature resistance under extreme marine environmental conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a tread compound composition and its preparation method, as well as its application in aircraft tire treads. The tread compound composition provided by this invention has good resistance to solar radiation and mildew, as well as good wear resistance, thermal stability, high tensile strength, tear strength, and 300% constant elongation stress, which meets the requirements of high load, high speed, and high impact takeoff and landing conditions. At the same time, the tread compound has good cut resistance, which can reduce the appearance of fish scale patterns on the tire during use and thus extend its service life.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a tread rubber compound composition comprising the following components in parts by weight: 100 parts natural rubber, 40-53 parts carbon black, 2-6 parts liquid butadiene rubber, 1-3 parts anti-cracking resin, 1-6 parts titanium dioxide, 2-4 parts silane coupling agent, 1-4 parts heat stabilizer, 0.5-2.5 parts anti-reversion agent, 1-4 parts nano zinc oxide, 1-3 parts stearic acid, 1-4 parts antioxidant, 0.5-2 parts light stabilizer, 1-3 parts protective wax, 0.5-3 parts anti-mildew and antibacterial agent, 1.5-2.5 parts insoluble sulfur, 1.2-2.2 parts sulfenamide accelerator; The natural rubber has a tensile strength ≥25MPa, elongation at break ≥800%, tear strength ≥30kN / m, and nitrogen content ≤0.32%; the carbon black has an STSA value of 115~137m. 2 / g, DBP absorbance value 92~127cm 3 / 100g.

[0007] Preferably, the natural rubber has a nitrogen content of 0.16~0.32%, generates heat upon compression ≤8℃, and develops cracks after ozone aging for ≥6h.

[0008] Preferably, the carbon black comprises N134 and / or N115.

[0009] Preferably, the liquid butadiene rubber is LBR-50; the anti-cracking resin is AD-1600; the titanium dioxide is PGA110; the silane coupling agent is Si69; the heat stabilizer is HS-80; and the anti-reversion agent is SL-9088.

[0010] Preferably, the antioxidant is p-phenylenediamine antioxidant 4020; the light stabilizer is UV-P; the protective wax is HW230; the antifungal and antibacterial agent is AM-907h and / or AM102ZP; the insoluble sulfur is IS-HS-7020 or HD OT20; and the sulfenamide accelerator is NS and / or DZ.

[0011] This invention provides a method for preparing the compound of the tread rubber composition described in the above technical solution, comprising the following steps: Natural rubber, liquid butadiene rubber, heat stabilizer and carbon black are mixed and compounded in one stage to obtain a first stage masterbatch; The first-stage masterbatch, nano zinc oxide, stearic acid, anti-crack resin, titanium dioxide, silane coupling agent, antioxidant, light stabilizer, antifungal and antibacterial agent and protective wax are mixed and then compounded in a second stage to obtain a second-stage masterbatch. The two-stage masterbatch, insoluble sulfur, sulfenamide accelerator, and anti-reversion agent are mixed and compounded in three stages to obtain the compound of the tread rubber composition.

[0012] This invention provides the application of the tread rubber compound composition described above in tire treads.

[0013] Preferably, the tire is an aircraft tire.

[0014] Preferably, the tire is a tire used in marine environmental conditions.

[0015] The present invention provides a tire whose tread is made of the tread rubber compound composition described in the above technical solution or the compound prepared by the preparation method described in the above technical solution.

[0016] This invention provides a tread rubber compound composition comprising the following components in parts by weight: 100 parts natural rubber, 40-53 parts carbon black, 2-6 parts liquid butadiene rubber, 1-3 parts anti-cracking resin, 1-6 parts titanium dioxide, 2-4 parts silane coupling agent, 1-4 parts heat stabilizer, 0.5-2.5 parts anti-reversion agent, 1-4 parts nano zinc oxide, 1-3 parts stearic acid, 1-4 parts antioxidant, 0.5-2 parts light stabilizer, 1-3 parts protective wax, 0.5-3 parts anti-mildew and antibacterial agent, 1.5-2.5 parts insoluble sulfur, and 1.2-2.2 parts sulfenamide accelerator; wherein the natural rubber has a tensile strength ≥25 MPa, elongation at break ≥800%, tear strength ≥30 kN / m, and nitrogen content ≤0.32%; and the carbon black has an STSA value of 115-137 m. 2 / g, DBP absorbance value 92~127cm 3 / 100g. The tread rubber compound composition provided by this invention uses natural rubber with the above-mentioned performance parameters as the main material, and includes the following auxiliary materials: ultra-abrasion-resistant small-particle-size carbon black with the above-mentioned properties, titanium dioxide, light stabilizer, silane coupling agent, anti-mildew and antibacterial agent, nano zinc oxide, protective wax, anti-cracking resin, anti-reversion agent, and liquid butadiene rubber. Compared with the prior art, this invention has the following beneficial effects: The tread rubber compound composition provided by this invention exhibits excellent resistance to solar radiation. This invention utilizes ultra-abrasion-resistant small-particle-size carbon black (STSA value 115~137 μm) with the aforementioned performance parameters. 2 As a reinforcing agent, carbon black with a smaller particle size provides better UV shielding, helps slow down photoaging, has higher photon absorption efficiency, and better resistance to solar radiation. The addition of titanium dioxide, an inorganic compound, effectively improves the tread rubber's resistance to solar radiation and high temperatures due to its resistance to sun exposure, high temperatures, and acids and alkalis. Silane coupling agents form an interfacial bridging structure between the natural rubber matrix and the titanium dioxide filler, improving resistance to solar radiation without reducing tensile and tear strength, and imparting good thermal stability and dynamic balance to the compound. The addition of light stabilizers further helps resist photoaging and improves thermal stability.

[0017] The tread rubber compound composition provided by this invention has excellent anti-mold properties. This invention uses natural rubber with low nitrogen content as the raw rubber system, reducing the risk of mold growth from the source; nano-zinc oxide replaces ordinary zinc oxide, and zinc ions can inhibit the growth and reproduction of mold; the anti-mold and antibacterial agent slowly migrates to the rubber surface, comes into contact with mold spores in the air, and penetrates the cell wall and cell membrane to achieve the anti-mold effect; the protective wax forms a dense film, which can physically isolate moisture and mold spores in the air; the silane coupling agent has good hydrophobicity, which helps to isolate moisture and air, thus preventing mold growth.

[0018] The tread compound composition provided by this invention has excellent low-temperature resistance. This invention uses liquid butadiene rubber instead of traditional softener aromatic oil, which has a glass transition temperature (Tg) as low as -100℃ to -110℃. It also exhibits good compatibility with natural rubber, significantly improving the low-temperature resistance of the compound and enabling tires to meet the requirements for use under extreme low-temperature conditions.

[0019] The tread rubber compound composition provided by this invention possesses excellent mechanical and durability properties. The natural rubber used in this invention exhibits the aforementioned performance parameters, with a tensile strength ≥25.0 MPa and a tear strength ≥30 kN / m, significantly superior to imported Indonesian No. 1 smoked sheet rubber (measured tensile strength 21.0 MPa, tear strength 25 kN / m), thus imparting higher tensile strength, tear strength, and elongation at break to the tread rubber. Ultra-abrasion-resistant small-particle carbon black significantly improves the abrasion resistance of the compound. Nano-zinc oxide enhances tensile strength, abrasion resistance, and tear resistance. Anti-reversion agents provide the vulcanized rubber with excellent anti-reversion and heat resistance properties. Anti-cracking resin improves crack resistance and fracture resistance, enhances cut and puncture resistance, and reduces fish-scale pattern issues. Protective wax provides all-weather ozone protection.

[0020] In summary, the tread compound composition provided by this invention has the characteristics of good resistance to solar radiation, mildew resistance, good cut resistance, good wear resistance, good thermal stability, and low brittle temperature. At the same time, it has high tensile strength, tear strength, and 300% constant elongation stress, which fully meets the performance requirements of aviation tire tread compounds under extreme working conditions in marine environments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the longitudinal section structure of a tire; In the diagram: 1-tread rubber, 2-belt layer, 3-carcass ply, 4-airtight layer, 5-sidewall rubber, 6-bead. Detailed Implementation

[0022] This invention provides a tread rubber compound composition comprising the following components in parts by weight: 100 parts natural rubber, 40-53 parts carbon black, 2-6 parts liquid butadiene rubber, 1-3 parts anti-cracking resin, 1-6 parts titanium dioxide, 2-4 parts silane coupling agent, 1-4 parts heat stabilizer, 0.5-2.5 parts anti-reversion agent, 1-4 parts nano zinc oxide, 1-3 parts stearic acid, 1-4 parts antioxidant, 0.5-2 parts light stabilizer, 1-3 parts protective wax, 0.5-3 parts anti-mildew and antibacterial agent, 1.5-2.5 parts insoluble sulfur, 1.2-2.2 parts sulfenamide accelerator; The natural rubber has a tensile strength ≥25MPa, elongation at break ≥800%, tear strength ≥30kN / m, and nitrogen content ≤0.32%; the carbon black has an STSA value of 115~137m. 2 / g, DBP absorbance value 92~127cm 3 / 100g.

[0023] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0024] The tread rubber compound composition provided by this invention comprises 100 parts by weight of natural rubber. In this invention, the natural rubber has a tensile strength ≥25 MPa, elongation at break ≥800%, tear strength ≥30 kN / m, and nitrogen content ≤0.32%. Preferably, the nitrogen content of the natural rubber is 0.16~0.32%, compression heat generation ≤8℃, and cracks appear after ozone aging for ≥6 hours.

[0025] In this invention, the natural rubber is domestically produced high-end natural rubber. By using microorganisms to coagulate the natural rubber latex, the protein content in the natural rubber is appropriately reduced, thereby increasing its tensile strength, elongation at break, and tear strength, reducing compression heat generation, and improving its resistance to ozone aging. Domestically produced high-end natural rubber exhibits higher strength and elongation, lower heat generation, and better ozone aging resistance and mildew resistance than ordinary domestically produced natural rubber.

[0026] The product parameters of the natural rubber used in this invention are shown in Table 1.

[0027] Table 1 Product parameters of natural rubber

[0028] In a specific embodiment of the present invention, the manufacturer of the natural rubber is Yunnan Natural Rubber Industry Group Jiangcheng Co., Ltd. The tread rubber compound composition provided by the present invention uses natural rubber with the best tear strength and comprehensive performance among common raw rubber types, especially high-end domestic natural rubber. Its tensile strength, tear strength, and elongation at break are significantly higher than those of imported Indonesian No. 1 smoked sheet rubber, while its nitrogen content is significantly lower. A comparison of the performance of the natural rubber used in the present invention with that of imported Indonesian No. 1 smoked sheet rubber is shown in Table 2.

[0029] Table 2. Performance Comparison Results of Natural Rubber and Imported Indonesian No. 1 Smoked Sheet Rubber

[0030] This invention uses domestically produced high-end natural rubber, which can give the tread compound of aircraft tires high tensile strength, elongation at break and tear strength, while having low nitrogen content and being less prone to mold growth.

[0031] Based on the mass fraction of the natural rubber, the tread compound composition provided by the present invention comprises 40-53 parts of carbon black, and in the examples, it may be 45, 48, or 50 parts. In the present invention, the STSA value of the carbon black is 115-137 m. 2 / g, preferably 124~137m 2 / g; DBP absorbance value 92~127cm 3 / 100g, preferably 113~127cm 3 / 100g. In this invention, the carbon black preferably includes N134 and / or N115. The preferred use of N134 and / or N115 as a reinforcing agent in this invention can significantly improve the wear resistance of the rubber compound. Furthermore, the smaller the particle size of the carbon black, the larger its specific surface area (STSA value), the larger the contact area with light, the higher its photon absorption efficiency, and the better its resistance to solar radiation. Simultaneously, the formulation system of this invention provides excellent reinforcing effects.

[0032] Based on the mass fraction of natural rubber, the tread compound composition provided by this invention includes 2 to 6 parts of liquid butadiene rubber, with 2 or 3 parts in the examples. In this invention, the liquid butadiene rubber is preferably LBR-50. This invention uses liquid butadiene rubber instead of commonly used plasticizers in the art. Liquid butadiene rubber has a glass transition temperature (Tg) as low as -100℃ to -110℃, exhibiting excellent low-temperature resistance. Simultaneously, it has good compatibility with natural rubber, improving the processing performance of the compound while enhancing its low-temperature resistance, enabling tires to be used under extreme conditions.

[0033] Based on the mass fraction of the natural rubber, the tread compound composition provided by this invention includes 1-3 parts of anti-cracking resin, which may be 1.5 or 2 parts in the embodiments. In this invention, the anti-cracking resin is preferably AD-1600. The addition of AD-1600 anti-cracking resin in this invention can improve the crack resistance and fracture resistance of the tread compound, and enhance its cut resistance and puncture resistance, thereby reducing the occurrence of fish-scale patterns on the tire tread during tire use and increasing tire lifespan.

[0034] Based on the mass fraction of the natural rubber, the tread compound composition provided by this invention includes 1 to 6 parts of titanium dioxide, with 2, 4, or 5 parts in the embodiments. In this invention, the titanium dioxide is preferably PGA110, commonly known as titanium dioxide. By adding titanium dioxide PGA110, an inorganic substance resistant to sun exposure, high temperatures, and acids and alkalis, this invention improves the tread compound's resistance to solar radiation and high-temperature performance.

[0035] Based on the mass fraction of the natural rubber, the tread compound composition provided by this invention includes 2-4 parts of silane coupling agent, which may be 3 or 3.5 parts in the examples. In this invention, the silane coupling agent is preferably Si69. This invention also incorporates an appropriate silane coupling agent, which acts as a bridge between the natural rubber and titanium dioxide, improving the tread compound's resistance to solar radiation without reducing tensile and tear strength. It also imparts good thermal stability and dynamic balance to the compound. Furthermore, the silane coupling agent's good hydrophobicity helps to physically isolate moisture and air, preventing mold growth.

[0036] Based on the mass fraction of the natural rubber, the tread compound composition provided by this invention includes 1 to 4 parts of heat stabilizer, which may be 2 or 2.5 parts in the examples. In this invention, the heat stabilizer is preferably HS-80. The addition of a heat stabilizer in this invention improves the thermal stability of the tread compound.

[0037] Based on the mass fraction of the natural rubber, the tread compound composition provided by this invention includes 0.5 to 2.5 parts of an anti-reversion agent, which may be 1 or 1.5 parts in the examples. In this invention, the anti-reversion agent is preferably SL-9088. The addition of the anti-reversion agent SL-9088 in this invention enables the vulcanized rubber to have good anti-reversion properties and heat resistance, ensuring that the rubber does not degrade or degrades significantly under high load, high speed, and large impact conditions when the tread rubber temperature is high, thus significantly improving the heat resistance of the tread rubber.

[0038] Based on the mass fraction of the natural rubber, the tread compound composition provided by this invention includes 1 to 4 parts of nano zinc oxide, which may be 3.5 or 4 parts in the examples. This invention adds nano zinc oxide to replace ordinary zinc oxide. Nano zinc oxide is a highly efficient and multifunctional upgraded activator. Compared with ordinary zinc oxide, it can improve the tensile strength, abrasion resistance, tear resistance, faster vulcanization rate, and better operational safety of the tread compound. Furthermore, zinc ions inhibit the growth and reproduction of mold, thus achieving an anti-mold effect.

[0039] Based on the mass fraction of the natural rubber, the tread compound composition provided by the present invention includes 1 to 3 parts of stearic acid, which may be 2 parts in the examples.

[0040] Based on the mass fraction of the natural rubber, the tread compound composition provided by the present invention includes 1 to 4 parts of antioxidant, and in the examples, it can be 2.5 parts. In the present invention, the antioxidant is preferably p-phenylenediamine antioxidant 4020.

[0041] Based on the mass fraction of the natural rubber, the tread compound composition provided by the present invention includes 0.5 to 2 parts of a light stabilizer, which may be 1.5 parts in the examples. In the present invention, the light stabilizer is preferably UV-P.

[0042] Based on the mass fraction of the natural rubber, the tread compound composition provided by this invention includes 1-3 parts of protective wax, with 2 parts in the examples. In this invention, the protective wax is a high-temperature protective wax. Preferably, the protective wax is HW230. The high-temperature protective wax HW230 added in this invention has excellent high-temperature protection performance, forms a slow-drying, durable, dense, and flexible film, strongly hinders ozone penetration, achieving all-weather ozone protection, while also isolating moisture and airborne mold spores, thus helping the rubber compound prevent mold growth.

[0043] Based on the mass fraction of the natural rubber, the tread compound composition provided by this invention includes 0.5 to 3 parts of an antifungal and antibacterial agent, which may be 0.5, 1, or 1.5 parts in the embodiments. In this invention, the antifungal and antibacterial agent is preferably AM-907h and / or AM102ZP. The antifungal and antibacterial agent AM-907h added to the rubber compound by this invention slowly migrates to the rubber surface, comes into contact with airborne mold spores, and penetrates the cell walls and cell membranes of the mold spores to achieve an antifungal effect, meeting the product's usage conditions under extreme marine environmental conditions.

[0044] Based on the mass fraction of the natural rubber, the tread compound composition provided by the present invention includes 1.5 to 2.5 parts of insoluble sulfur, which may be 1.8 or 2 parts in the examples. In the present invention, the insoluble sulfur is preferably IS-HS-7020 or HD OT 20.

[0045] Based on the mass fraction of the natural rubber, the tread compound composition provided by the present invention includes 1.2 to 2.2 parts of sulfenamide accelerator; in the examples, it can be 1.6 or 1.8 parts. In the present invention, the sulfenamide accelerator is preferably NS and / or DZ.

[0046] The tread compound composition provided by this invention, through the rational formulation of other components, gives the tread compound excellent properties such as good resistance to solar radiation, good cut resistance, good wear resistance, good thermal stability, and mildew resistance. It also features high tensile strength, tear strength, 300% tensile stress, and low brittle temperature. When used in aircraft tires under marine environmental conditions and extreme operating conditions, the tread compound exhibits good resistance to solar radiation, long storage and service life, and is not prone to mildew growth, meeting the stringent operating conditions of tires in extreme marine environments.

[0047] This invention provides a method for preparing the compound of the tread rubber composition described in the above technical solution, comprising the following steps: Natural rubber, liquid butadiene rubber, heat stabilizer and carbon black are mixed and compounded in one stage to obtain a first stage masterbatch; The first-stage masterbatch, nano zinc oxide, stearic acid, anti-crack resin, titanium dioxide, silane coupling agent, antioxidant, light stabilizer, antifungal and antibacterial agent and protective wax are mixed and then compounded in a second stage to obtain a second-stage masterbatch. The two-stage masterbatch, insoluble sulfur, sulfenamide accelerator, and anti-reversion agent are mixed and compounded in three stages to obtain the compound of the tread rubber composition.

[0048] This invention involves mixing natural rubber, liquid butadiene rubber, a heat stabilizer, and carbon black in a single-stage mixing process to obtain a first-stage masterbatch. In this invention, the rotor speed during the single-stage mixing is preferably 30-35 r / min; the preferred feeding order is: natural rubber, liquid butadiene rubber, heat stabilizer, and carbon black. After the single-stage mixing is completed, the rubber is discharged to obtain the first-stage masterbatch.

[0049] After obtaining a primary masterbatch, this invention involves mixing the primary masterbatch, nano-zinc oxide, stearic acid, anti-crack resin, titanium dioxide, silane coupling agent, antioxidant, light stabilizer, antifungal and antibacterial agent, and protective wax in a second-stage mixing process to obtain a secondary masterbatch. In this invention, the rotor speed for the second-stage mixing is preferably 30-35 r / min. The feeding sequence for the second-stage mixing is: primary masterbatch, nano-zinc oxide, stearic acid, anti-crack resin, titanium dioxide, silane coupling agent, antioxidant, light stabilizer, antifungal and antibacterial agent, and protective wax. After the second-stage mixing is completed, the adhesive is discharged to obtain the secondary masterbatch.

[0050] After obtaining the second-stage masterbatch, the present invention mixes the second-stage masterbatch, insoluble sulfur, sulfenamide accelerator, and anti-reversion agent for three-stage compounding to obtain the compounded tread rubber composition. In the present invention, the rotor speed for the three-stage compounding is preferably 30-35 r / min. The preferred order of feeding the materials in the three-stage compounding is: second-stage masterbatch, insoluble sulfur, accelerator, and anti-reversion agent. After the three-stage compounding is completed, the rotor is lifted 2-3 times, and then the rubber is discharged to obtain the compounded tread rubber composition.

[0051] This invention provides the application of the tread rubber compound composition described above in tire treads.

[0052] In this invention, the tire is an aircraft tire. In this invention, the tire is a tire used in marine environmental conditions.

[0053] The present invention provides a tire whose tread is made of the tread rubber compound composition described in the above technical solution or the compound prepared by the preparation method described in the above technical solution.

[0054] The tire manufacturing method provided by the present invention preferably includes the following steps: extruding the tread rubber compound composition into a tread semi-finished product using an extruder; attaching the tread semi-finished product to the upper part of the belt layer on a molding machine to form a tire blank; and vulcanizing the tire blank using a vulcanizing machine to obtain the finished tire. The vulcanization temperature is preferably 135~138℃, and the vulcanization time is preferably 50~100 min.

[0055] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0056] Examples 1-3 The formulations of the tread rubber compounds provided in Examples 1-3 are shown in Table 3.

[0057] Table 3 Formulations (parts by weight) of the tread rubber compound compositions provided in Examples 1-3

[0058] The preparation methods of the tread rubber compound compositions provided in Examples 1-3 are as follows: The rubber compound is mixed in three stages, all within a GK250E internal mixer: The rotor speed of the first mixing stage is 35 r / min. The feeding sequence is: raw rubber, liquid butadiene rubber, heat stabilizer HS-80 → super wear-resistant carbon black N115 → discharge rubber.

[0059] The rotor speed for the two-stage mixing process is 35 r / min. The feeding sequence is as follows: primary masterbatch → nano zinc oxide, stearic acid, anti-cracking resin AD-1600, titanium dioxide PGA110, silane coupling agent Si69, antioxidant 4020, light stabilizer UV-P, anti-mildew and antibacterial agent AM-907h, protective wax HW230 → discharge.

[0060] The rotor speed for the three-stage mixing (final mixing) is 30 r / min. The feeding sequence is: second-stage masterbatch, insoluble sulfur IS-HS-7020, accelerator NS, anti-sulfurization reversion agent SL-9088 → lifting the plug 2~3 times → discharging the rubber.

[0061] The performance test data of the tread compound prepared using Example 1 are shown in Table 4. The prior art in Table 4 is a conventional tread compound, with the following specific formulation (parts by weight): Conventional formulation: 100 parts of No. 1 smoked sheet rubber, 50 parts of medium-strength abrasion-resistant carbon black N220, 4 parts of aromatic oil, 10 parts of precipitated silica, 1 part of silane coupling agent Si69, 5 parts of zinc oxide, 2 parts of stearic acid, 1.5 parts of antioxidant 4020, 1.5 parts of antioxidant RD, 2 parts of protective wax RP-3, 2.1 parts of insoluble sulfur IS-60, and 1.2 parts of accelerator NS. The preparation method of the conventional tread compound is basically the same as that in Example 1, except that a conventional tread compound formulation is used.

[0062] Table 4. Performance test data of the compound rubber prepared in Example 1

[0063] Compared with existing rubber compounds, the rubber compound made using the formulation of Example 1 has the following advantages: (1) The rubber compound of the present invention has better resistance to solar radiation. After 56 days of solar radiation test, the tensile strength of the rubber compound is 23.8 MPa and the elongation at break is 396%, which is significantly better than the 15.3 MPa and 195% of the existing rubber compound. This is because the present invention adds an appropriate amount of titanium dioxide PGA110 and silane coupling agent, and uses p-phenylenediamine antioxidant 4020 and light stabilizer UV-P in the anti-aging system. At the same time, it uses ultra-abrasion resistant carbon black N115 with smaller particle size as a reinforcing agent, which greatly improves the resistance to solar radiation of the rubber compound without significantly reducing the strength and other key properties of the rubber compound. This is the innovation of the present invention; (2) The anti-mildew effect is better. After 84 days of mold test, the mold growth level of the rubber compound is 0, while the existing rubber compound reaches level 3 mold growth. The antifungal and antibacterial agents used in this invention are AM-907h and / or AM102ZP, which can improve the antifungal performance of the rubber compound. However, when added to the tread compound which is mainly composed of natural rubber, the tear strength of the rubber compound will decrease by more than 10kn / m. This invention adopts the following measures, such as using domestic high-end natural rubber with lower nitrogen content for raw rubber, using ultra-abrasion-resistant carbon black N115 with smaller particle size as reinforcing agent, and the reasonable configuration of other components, which improves the antifungal performance of the rubber compound without significantly reducing the strength, abrasion resistance and other key properties of the rubber compound; (3) The low temperature resistance of this invention is better (no damage at -62℃), because compared with the prior art (no damage at -55℃), this invention uses liquid butadiene rubber with a glass transition temperature Tg as low as -100℃~-110℃ to replace the commonly used softener in the field, which makes the low temperature brittleness of the rubber compound better; (4) The cutting resistance is better (cutting loss of 1.501g), while the cutting loss of the prior art rubber compound is 2.417g. Because this invention incorporates an anti-cracking resin that improves the crack resistance and fracture resistance of the rubber compound and is equipped with a suitable vulcanization system, it improves the tread rubber's resistance to cutting and punctures without significantly reducing the strength and other key properties of the rubber compound; (5) This invention is more wear-resistant (wear reduction of 0.115 cm). 3 / 1.61km), compared to existing technology (wear reduction of 0.154 cm). 3 Compared to / 1.61km), the reinforcing system of the present invention uses ultra-abrasion resistant carbon black N115 or N134 with finer particle size, and at the same time eliminates the softener that would reduce abrasion resistance, making the abrasion resistance of the rubber compound better; (6) the high temperature resistance is better (the torque curve change rate of the vulcanizer at 165℃×60min is 0, while the prior art is -7.6%), because the present invention uses stabilizer HS-80, light stabilizer UV-P and anti-vulcanization reversion agent SL-9088 at the same time, which improves the high temperature resistance of the rubber compound.

[0064] The performance test data of the tread rubber compounds prepared in Examples 2 and 3 are shown in Table 5: Table 5. Performance test data of the tread rubber compounds prepared in Examples 2 and 3

[0065] The preparation process of each of the above embodiments is the same: the raw materials are mixed in an internal mixer according to the ratio to produce a compound rubber, and the compound rubber is extruded into a tread semi-finished product by an extruder. The tread semi-finished product is attached to the upper part of the belt layer on a molding machine to form a tire blank, and the tire blank is vulcanized by a vulcanizing machine to become a finished tire.

[0066] As can be seen from the above embodiments, the present invention provides a tread compound composition with good resistance to solar radiation and mildew prevention, suitable for aircraft tires used in extreme marine environments. This tread compound is mainly composed of domestically produced high-end natural rubber, and also contains ultra-wear-resistant small-particle carbon black (STSA value 124 μm). 2 / g~137m 2 / g, DBP absorbance 113 cm⁻¹ 3 / 100g~127 cm 3 This tread compound is made from a specific ratio of main auxiliary materials including (100g), titanium dioxide PGA110, light stabilizer, silane coupling agent, antifungal and antibacterial agent, nano zinc oxide, high-temperature protective wax, anti-cracking resin, anti-reversion agent SL-9088, and liquid butadiene rubber. It exhibits excellent resistance to solar radiation and antifungal properties, along with good cut resistance, abrasion resistance, thermal stability, and low brittle temperature. Furthermore, it boasts high tensile strength, tear strength, and 300% tensile stress, meeting the performance requirements of aviation tire tread compounds used in extreme marine environments.

[0067] The properties of the tread rubber compound composition with good resistance to solar radiation and mildew resistance provided by the present invention are shown in Table 6.

[0068] Table 6. Performance of the tread rubber compound composition with good solar radiation resistance and mildew resistance provided by the present invention.

[0069] As shown in Table 6, the tread compound composition with good solar radiation resistance and mildew resistance provided by this invention is suitable for use in extreme marine environments. It exhibits excellent solar radiation resistance and mildew resistance, along with good wear resistance, thermal stability, high tensile strength, tear strength, and 300% constant elongation stress, meeting the requirements of high-load, high-speed, and high-impact takeoff and landing conditions. Furthermore, because aircraft tires have low belt layer elongation, high crown rigidity, and bear high stress, the tread compound is easily cut when gliding on rough or sharply textured runways, forming herringbone cuts—commonly known as fish scale patterns. The tread compound provided by this invention has good cut resistance, which can reduce the occurrence of fish scale defects on the tread during tire use, thereby extending tire life.

[0070] Comparative Example 1 Table 7 Formulation (parts by weight) of the tread rubber compound composition provided in Comparative Example 1

[0071] The preparation method of Comparative Example 1 is basically the same as that of Example 1, except that the formulation shown in Table 7 is used. The performance test data of the tread compound provided by Comparative Example 1 are shown in Table 8.

[0072] Table 8. Test data of the compound properties of the tread rubber provided in Comparative Example 1

[0073] Test results of the tread compound compositions provided in Examples 1-3 and Comparative Example 1 show that titanium dioxide is a key component. If conventional precipitated silica is used, the solar radiation resistance is significantly reduced.

[0074] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A tread rubber compound composition, characterized in that, The components include the following parts by mass: 100 parts natural rubber, 40-53 parts carbon black, 2-6 parts liquid butadiene rubber, 1-3 parts anti-cracking resin, 1-6 parts titanium dioxide, 2-4 parts silane coupling agent, 1-4 parts heat stabilizer, 0.5-2.5 parts anti-reversion agent, 1-4 parts nano zinc oxide, 1-3 parts stearic acid, 1-4 parts antioxidant, 0.5-2 parts light stabilizer, 1-3 parts protective wax, 0.5-3 parts anti-mildew and antibacterial agent, 1.5-2.5 parts insoluble sulfur, 1.2-2.2 parts sulfenamide accelerator; The natural rubber has a tensile strength ≥25MPa, elongation at break ≥800%, tear strength ≥30kN / m, and nitrogen content ≤0.32%; the carbon black has an STSA value of 115~137m. 2 / g, DBP absorbance value 92~127cm 3 / 100g.

2. The tread rubber composition according to claim 1, characterized in that, The natural rubber has a nitrogen content of 0.16~0.32%, generates heat upon compression ≤8℃, and develops cracks after ozone aging for ≥6h.

3. The tread rubber composition according to claim 1, characterized in that, The carbon black includes N134 and / or N115.

4. The tread rubber compound composition according to claim 1, characterized in that, The liquid butadiene rubber is LBR-50; the anti-cracking resin is AD-1600; the titanium dioxide is PGA110; the silane coupling agent is Si69; the heat stabilizer is HS-80; and the anti-reversion agent is SL-9088.

5. The tread rubber compound composition according to claim 1, characterized in that, The antioxidant is p-phenylenediamine antioxidant 4020; the light stabilizer is UV-P; the protective wax is HW230; the antifungal and antibacterial agent is AM-907h and / or AM102ZP; the insoluble sulfur is IS-HS-7020 or HD OT 20; and the sulfenamide accelerator is NS and / or DZ.

6. A method for preparing the compound of the tread rubber composition according to any one of claims 1 to 5, characterized in that, Includes the following steps: Natural rubber, liquid butadiene rubber, heat stabilizer and carbon black are mixed and compounded in one stage to obtain a first stage masterbatch; The first-stage masterbatch, nano zinc oxide, stearic acid, anti-crack resin, titanium dioxide, silane coupling agent, antioxidant, light stabilizer, antifungal and antibacterial agent and protective wax are mixed and then compounded in a second stage to obtain a second-stage masterbatch. The two-stage masterbatch, insoluble sulfur, sulfenamide accelerator, and anti-reversion agent are mixed and compounded in three stages to obtain the compound of the tread rubber composition.

7. The application of the tread compound composition according to any one of claims 1 to 5 or the tread compound composition prepared by the preparation method according to claim 6 in tire tread.

8. The application according to claim 7, characterized in that, The tires mentioned are aircraft tires.

9. The application according to claim 7 or 8, characterized in that, The tires mentioned are tires used in marine environmental conditions.

10. A tire, characterized in that, The tread is made of the tread rubber compound composition according to any one of claims 1 to 5 or the compound prepared by the preparation method according to claim 6.

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