High-wear-resistance and high-resilience front sole shoe material, preparation method and shoe

Abstract

The invention discloses a high-wear-resistance and high-resilience front sole shoe material, a preparation method and a shoe. The front sole shoe material is prepared from the following components in parts by weight: 100 parts of a rubber matrix, 30 to 42 parts of reinforcing filler, 20 to 25 parts of a flexible reinforcing phase, 2 parts of sulfur, 0.5 to 2 parts of an accelerant, 4 to 7 parts of an active agent and 1.5 to 3 parts of an anti-aging agent, the flexible reinforcing phase is thermoplastic polyurethane, the thermoplastic polyurethane forms a three-dimensional nanofiber network in situ in a rubber matrix through a shear field, fibers in the three-dimensional nanofiber network are preferentially oriented in the processing direction, and the in-situ formation, the preferential orientation and the flexible network are cooperated to form the flexible composite material. A unique reinforcing structure which is firm in combination, uniform in distribution and controllable in reinforcing direction is constructed in a rubber matrix, and conversion from single rigid particle dispersion reinforcement to composite flexible fiber network reinforcement is realized, so that the front sole shoe material has high wear resistance, high rebound resilience and high toughness.

Description

TECHNICAL FIELD

[0001] The present application relates to shoes, in particular to a high-wear-resistance and high-resilience forefoot shoe material, a preparation method and a shoe. BACKGROUND

[0002] The forefoot part of shoes, especially sports shoes and daily walking shoes, is the core power point in the "propulsion period" of the gait cycle. This part simultaneously bears the huge impact force from the ground, frequent bending deformation and driving power demand when stepping off the ground during walking, running, jumping and other actions. This puts forward more stringent comprehensive performance requirements on the rubber material for manufacturing the outsole of this part: high wear resistance to ensure service life, excellent resilience to ensure efficient energy feedback and propulsion efficiency, and good toughness to resist tearing caused by repeated bending.

[0003] Currently, the industry generally uses high specific surface area nano fillers (such as carbon black and white carbon black) in the rubber matrix as the main means to improve performance. The fillers limit the movement of rubber molecular chains, thereby significantly improving the hardness, strength and wear resistance of the material.

[0004] However, this reinforcing method has an inherent limitation: while the fillers improve the hardness and wear resistance, they often cause a decrease in the resilience of the rubber compound and an increase in hysteresis loss. The fundamental reason is that the rigid filler network limits the movement of the rubber molecular chains, increasing the internal friction of the molecular chain segments during deformation, which converts more mechanical energy into heat dissipation rather than elastic rebound. Therefore, under the existing technical framework, the formulation design often faces the trade-off problem between wear resistance and resilience. SUMMARY

[0005] To synergistically improve the wear resistance, resilience and toughness of rubber materials, a high-wear-resistance and high-resilience forefoot shoe material, a preparation method and a shoe are provided.

[0006] The above first invention object of the present application is achieved by the following technical scheme: A high-wear-resistance and high-resilience forefoot shoe material, comprising the following components in parts by weight: 100 parts of a rubber matrix, 30-42 parts of a reinforcing filler, 20-25 parts of a flexible reinforcing phase, 2 parts of sulfur, 0.5-2 parts of an accelerator, 4-7 parts of an active agent, 1.5-3 parts of an antioxidant, The reinforcing filler is synthetic mica powder. The flexible reinforcing phase is a thermoplastic polyurethane, which forms a three-dimensional nanofiber network in situ in the rubber matrix through a shear field, and the fibers in the three-dimensional nanofiber network are preferentially oriented along the processing direction.

[0007] By adopting the above technical solution, a three-dimensional nanofiber network of thermoplastic polyurethane is formed in situ and preferentially oriented in the rubber matrix as a core reinforcing body to construct a material structure, not only relying on the physical mixing of rigid fillers for reinforcement, but also changing the interaction mode between the reinforcing phase and the rubber matrix: "In situ formation" means that the three-dimensional nanofiber network of polyurethane is not directly added in a prefabricated form, but is dynamically generated in the processing of the rubber compound. The specific process is as follows: the polyurethane particles melt at a mixing temperature higher than their melting point, and are dispersed in the rubber matrix in the form of micrometer-sized droplets; then, in the calendering or open mill process, the compound passes through a specific high-shear roll gap, and the molten polyurethane droplets are severely stretched, deformed and refined under the action of strong shear force and tensile flow field, and finally are directly converted into fibers with a diameter of nanometers to sub-microns and a high aspect ratio inside the rubber matrix; the fibers thus formed have their surfaces and the surrounding rubber molecular chains interpenetrated and entangled under high-temperature shear, forming a firm physical bonding interface; In contrast to the poor interface compatibility and easy debonding problems often encountered with direct addition of prefabricated fibers, the stress can be efficiently transmitted from the flexible rubber matrix to the relatively rigid polyurethane fibers, thereby fully exerting their reinforcing effect; The preferential orientation of the fibers in the three-dimensional nanofiber network along the processing direction is to realize the directional optimization of the reinforcing effect in space. By controlling the processing flow field to produce strong and directional shear flow inside the compound, the polyurethane fibers formed in situ in this flow field are not randomly arranged, but are preferentially arranged along the flow direction, i.e. the main shear direction. For the forefoot outsole, the axial orientation of most polyurethane fibers is parallel to the sole surface. When the sole is forced to the ground, the three-dimensional nanofiber network arranged in this direction can form the most effective stress transmission path along the force direction, thereby providing high modulus, tear resistance and rebound response in this direction, realizing the anisotropic design of mechanical properties, and optimizing the performance configuration to match the actual working conditions; The "flexible" property of the three-dimensional nanofiber network is the key to solving the contradiction between high wear resistance and high resilience. The modulus of polyurethane itself is much higher than that of the rubber matrix but significantly lower than that of the traditional rigid filler. Therefore, the three-dimensional nanofiber network can bear load, improve strength and wear resistance while the restriction on the movement of the rubber molecular chain is relatively weak. In dynamic deformation, the rubber molecular chain can still maintain high movement ability, and the macroscopic performance is that the hysteresis loss of the material is small, and the resilience is maintained. In addition, the three-dimensional nanofiber network can efficiently dissipate impact energy through fiber stretching, sliding and interaction between the fiber and the matrix interface, thereby improving the toughness and fatigue resistance of the material.

[0008] In summary, through the synergy of "in-situ formation", "preferential orientation" and "flexible network", a unique reinforcing structure with firm combination, uniform distribution and controllable reinforcing direction is constructed in the rubber matrix, realizing the transition from single "rigid particle dispersion reinforcement" to composite "flexible fiber network reinforcement", so that the forefoot shoe material has high wear resistance, high resilience and high toughness.

[0009] Optionally, the synthetic mica powder is a modified synthetic mica powder, and a polymer gradient interface layer is constructed on the surface of the modified synthetic mica powder. The inside of the polymer gradient interface layer is a rigid segment combined with the surface of the lamellar crystal by a strong chemical bond, and the outside is a flexible segment with good compatibility with the rubber matrix. The plane of the synthetic mica powder is oriented and arranged parallel to the macroscopic surface of the forefoot shoe material.

[0010] By adopting the above technical solution, the synthetic mica powder is constructed with a polymer gradient interface layer, and the polymer gradient interface layer forms a continuous transition zone from the filler phase to the matrix phase, which can effectively smooth the stress transfer and avoid stress concentration at the interface, thereby significantly enhancing the interfacial bonding strength. At the same time, the plane of the synthetic mica powder is controlled to be arranged parallel to the macroscopic surface of the forefoot shoe material, so that the synthetic mica powder forms an ordered and continuous in-plane reinforcing network on the worn surface of the material. When the material is subjected to friction or impact, the in-plane reinforcing network directly resists wear through its high hardness and strength in the plane, and forces the crack tip to deflect, bypass or branch during the propagation process, thereby consuming a large amount of energy and improving the wear resistance and tear resistance of the material. Therefore, through the microstructure design of the "gradient interface layer" and the "lamellar crystal directional arrangement", the interfacial compatibility problem between the rigid filler and the rubber matrix is solved, and the reinforcing efficiency of the filler is maximized by constructing an ordered reinforcing network, while the wear resistance and toughness are improved.

[0011] Optionally, the aspect ratio of the synthetic mica powder is 20-30.

[0012] By adopting the technical scheme, the flake crystals can respond to the processing flow field, and an ordered reinforcing network is successfully constructed, so that the microstructure of the required gradient interface layer is obtained, When the diameter-thickness ratio is 20-30, it means that the flake crystals have the geometric characteristics of "large plane and thin thickness". In the mixing and calendering process, the high diameter-thickness ratio makes the flake crystals more easily rotate and orient in the shearing flow field, and the plane of the flake crystals is subjected to strong drag force of the fluid, so as to be effectively turned to be parallel to the flow field direction, and finally realize the highly ordered arrangement of "the plane being parallel to the surface of the front sole material". If the diameter-thickness ratio of the flake crystals is too small, the flake crystals cannot be effectively oriented, and the effect is the same as that of ordinary particle fillers, so that the gradient interface layer structure advantage and synergistic toughening effect will be greatly reduced. In addition, the flake crystals with high diameter-thickness ratio can form a larger area and more continuous overlapping barrier in the matrix at a lower addition amount, and can more effectively hinder the external wear and internal crack propagation path.

[0013] Optionally, the polymer gradient interface layer is a methyl methacrylate-n-butyl acrylate copolymer grafted by a silane coupling agent, and the thickness is 300-400 nm.

[0014] By adopting the technical scheme, when the thickness of the interface layer is less than 300 nanometers, the modulus transition interval is too short, and the modulus mutation between the rigid filler and the flexible rubber matrix cannot be fully relieved; when the thickness is more than 400 nanometers, the over-thick polymer layer may weaken the flexibility and filler combination force of the polymer layer itself, and thus the overall reinforcing efficiency is reduced; the thickness of 300-400 nanometers ensures that the interface layer has sufficient space volume, so that the polymer chain segments can form a continuous conformational change from rigid to flexible in the thickness direction, which ensures that the filler can effectively transfer stress when bearing load, and can prevent cracks from directly expanding to the inside of the filler through the plastic deformation of the interface layer, thereby significantly improving the fracture toughness and fatigue life of the composite material.

[0015] Optionally, the rubber matrix is composed of natural rubber and neodymium-based butadiene rubber.

[0016] By adopting the technical scheme, the natural rubber can be strain-induced crystallized under external force due to its high molecular chain regularity, and this characteristic endows the material with high tensile strength, tear resistance and resilience; however, the natural rubber has high internal heat during dynamic fatigue; The neodymium-based butadiene rubber has a high content of cis-1, 4 structure (usually > 98%), and the molecular chain is regular and flexible, so that the neodymium-based butadiene rubber has a low glass transition temperature, excellent high-speed resilience, low rolling resistance and internal heat. The two are used together to construct a high-performance elastomer matrix, and the natural rubber provides a strong skeleton and main entropic elastic recovery force as the matrix, and the neodymium-based butadiene rubber acts as a high-efficiency "dynamic performance regulator", and the low internal friction of the molecular chain significantly reduces the energy loss (hysteresis loss) of the composite material in periodic deformation, thereby effectively inhibiting the temperature rise during use and improving the dynamic fatigue resistance of the material.

[0017] Optionally, the mass ratio of the natural rubber to the neodymium-based butadiene rubber is (50-70):(30-50).

[0018] By further limiting the mass ratio of the natural rubber to the neodymium-based butadiene rubber, the balance between the strength, resilience and internal heat of the material is optimized, and the performance of the matrix rubber is ensured to be in the best synergistic state, neither too hard to lose resilience nor too soft to lack support.

[0019] The above-mentioned second invention of the present application is realized by the following technical solution: The preparation method of the high-wear-resistance and high-resilience forefoot shoe material includes the following steps: S1 mixing: uniformly mixing the rubber matrix, reinforcing filler, thermoplastic polyurethane particles and other additives in a mixer at 140-160 DEG C to obtain a mixed rubber, and the melting point of the thermoplastic polyurethane particles is lower than the mixing temperature; S2 orientation and fiber formation: performing multiple thin passes and calendering treatment on the mixed rubber obtained in step S1 on an open mill and a calender, controlling the roll temperature to be 130-150 DEG C, and applying a shear field with a shear rate of not less than 1000 s-1 by adjusting the roll gap to obtain a rubber sheet; S3 vulcanization and shaping: vulcanizing the rubber sheet treated in step S2 to obtain the forefoot shoe material.

[0020] By adopting the above technical solution, the three-step process of "mixing-orientation and fiber formation-vulcanization" is used to prepare the forefoot shoe material, and in the second step, the in-situ fiberization of the polyurethane is realized by using a precisely controlled shear field, thereby providing a reliable and controllable preparation method and ensuring the accurate formation of the micro-level ordered structure in the forefoot shoe material.

[0021] The above-mentioned three invention purposes of the present application are realized by the following technical solution: A shoe, wherein the forefoot outer sole part is made of the high-wear-resistance and high-resilience forefoot shoe material.

[0022] By adopting the above technical solution, the forefoot shoe material of the present application is applied to the forefoot outer sole part of the shoe, and the synergistic optimization of wear resistance, resilience and service life is realized.

[0023] In summary, the present application at least has the following beneficial effects: 1. By forming an oriented three-dimensional nanofiber network in situ under the action of a shear field through thermoplastic polyurethane, a new composite material system with "flexible reinforcement" is constructed, which solves the contradiction that traditional rigid filler reinforcement leads to a decrease in resilience, and realizes the synergistic improvement of high wear resistance and high resilience; 2. Synthetic mica powder with a gradient interface layer is used as a reinforcing filler, and the modulus gradient of the interface layer effectively relieves stress concentration, and the oriented arrangement of the platelets forms an optimal anti-wear barrier, which significantly improves the wear resistance and toughness of the material; 3. Through an optimized preparation process, the oriented arrangement of platelets and the fiberization of thermoplastic polyurethane are simultaneously controlled under specific shear field parameters, ensuring the precise construction of a multi-level ordered structure, and making the material performance have good consistency and repeatability. DETAILED DESCRIPTION

[0025] Natural rubber, domestic SCR5 standard rubber; Neodymium-based butadiene rubber, Langsheng CB22, neodymium-based catalyst, cis-1, 4 structure content ≥98%; Sulfur, commercially available rubber vulcanizing agent, industrial grade, purity 99.5%; Acetic acid, commercially available product, industrial grade, purity 99.9%; Aminopropyl triethoxysilane, commercially available product, purity 98%; Anhydrous toluene, commercially available product, water content <0.05wt%; RAFT chain transfer agent, 2- (dodecyltrithiocarbonate) -2-methylpropionic acid, commercially available product, purity 97wt%; Azobisisobutyronitrile, commercially available product, purity 98%; Methyl methacrylate, commercially available product, washed with alkali to remove polymerization inhibitor before use, purity 99wt%; n-Butyl acrylate, commercially available product, washed with alkali to remove polymerization inhibitor before use, purity 99wt%; Carbon black, commercially available rubber special product, particle size 50nm; Modified white carbon black, commercially available product with particle size 50nm mixed with aminopropyl triethoxysilane at a mass ratio of 100:0.03kg; Zinc oxide, commercially available rubber special active zinc oxide, purity 99.0wt%, particle size 400nm; Stearic acid, commercially available product, purity 98.5%, iodine value ≤2.0; Accelerator NS, antioxidant RD, 0.1kg antioxidant 4020, all are commercially available products; Synthetic mica powder, commercially available from Lingshou County Malin Mine Product Processing Factory, single product specification size stable, various specifications used in this application, see below; Thermoplastic polyurethane particles, particle size 5 pm, two melting point specifications used in this application; thermoplastic polyurethane particles with a melting point of 135℃ were obtained by crushing and sieving BASF Elastollan® 1185A, and thermoplastic polyurethane particles with a melting point of 180℃ were obtained by crushing and sieving Wanhua Chemical WHT-1590A; Polyurethane fibers with a length of 100 pm and a diameter of 500 nm were obtained by shearing after melt spinning of Wanhua Chemical WHT-1590A at 180℃.

[0026] Preparation Example 1 A modified synthetic mica powder with a polymer gradient interface layer constructed on the surface.

[0027] The specific preparation process is as follows: 1 kg of synthetic mica powder with a thickness of 1 pm and a planar size of 25 pm was dispersed in 5 kg of 90 wt% ethanol aqueous solution, and ultrasonic treatment was performed at a power of 500 W for 30 min to fully disperse it, then 0.05 kg of aminopropyltriethoxysilane was added at 280 rpm and mixed uniformly, the pH value of the reaction system was adjusted to 5.5 with acetic acid, and then the temperature was raised to 80℃, and the reaction was refluxed at 280 rpm for 6 h; After the reaction was completed, centrifugal separation was performed, and washing was performed three times with ethanol until the supernatant was colorless, and the obtained solid was vacuum dried at 80℃ to obtain aminated platelets; The obtained aminated platelets were redispersed in 5 L of anhydrous toluene, ultrasonic treatment was performed for 30 min, then the reaction system was placed in an ice bath, 5 g of a RAFT chain transfer agent was added, and high-purity nitrogen gas was bubbled for 30 min to remove oxygen in the reaction system; The reaction system was warmed to 70℃ and maintained in a nitrogen atmosphere, 1 g of azobisisobutyronitrile was dissolved in 100 mL of anhydrous toluene to prepare an initiator solution, the initiator solution was injected into the reaction system, and stirring and dropwise addition of 400 g of methyl methacrylate and 600 g of n-butyl acrylate (see Table 1 for dropwise addition rate control) were simultaneously started, the system temperature was maintained at 70℃, and the stirring rate was 200 rpm, after the monomer dropwise addition was completed, the reaction was continued until the total reaction time reached 12 h; After the reaction was completed, the reaction system was cooled to room temperature, the solid product was centrifugally separated, repeatedly washed and centrifuged with fresh toluene until the supernatant was colorless and transparent, and the final product was dried in a vacuum oven at 60℃ for 24 h until the weight was constant, ground and dispersed, and sieved to obtain a modified synthetic mica powder.

[0028] Table 1. Methyl methacrylate, n-butyl acrylate dropwise addition rate table

[0029] The average thickness of the polymer gradient interface layer on the modified synthetic mica powder is 350 nm, as measured by sampling.

[0030] Preparation Example 2 A modified synthetic mica powder, which is different from Preparation Example 1 in that the synthetic mica powder used has a thickness of 1 μm and a planar size of 5 μm.

[0031] Preparation Example 3 A modified synthetic mica powder, which is different from Preparation Example 1 in that the synthetic mica powder used has a thickness of 1 μm and a planar size of 20 μm.

[0032] Preparation Example 4 A modified synthetic mica powder, which is different from Preparation Example 1 in that the synthetic mica powder used has a thickness of 1 μm and a planar size of 30 μm.

[0033] Preparation Example 5 A modified synthetic mica powder, which is different from Preparation Example 1 in that the synthetic mica powder used has a thickness of 1 μm and a planar size of 45 μm.

[0034] Preparation Example 6 A modified synthetic mica powder, which is different from Preparation Example 1 in that the amount of methyl methacrylate dropped is 120 g, the amount of n-butyl acrylate dropped is 180 g, and the dropping speed is 30% of the dropping speed in Table 1.

[0035] The average thickness of the polymer gradient interface layer on the modified synthetic mica powder is 106 nm, as measured by sampling.

[0036] Preparation Example 7 A modified synthetic mica powder, which is different from Preparation Example 1 in that the amount of methyl methacrylate dropped is 343 g, the amount of n-butyl acrylate dropped is 514 g, and the dropping speed is 85.7% of the dropping speed in Table 1.

[0037] The average thickness of the polymer gradient interface layer on the modified synthetic mica powder is 300 nm, as measured by sampling.

[0038] Preparation Example 8 A modified synthetic mica powder, which is different from Preparation Example 1 in that the amount of methyl methacrylate dropped is 457 g, the amount of n-butyl acrylate dropped is 686 g, and the dropping speed is 114.3% of the dropping speed in Table 1.

[0039] The average thickness of the polymer gradient interface layer on the modified synthetic mica powder is 400 nm, as measured by sampling.

[0040] Preparation Example 9 A modified synthetic mica powder differs from Preparation Example 1 in that the amount of methyl methacrylate added is 571 g, the amount of n-butyl acrylate added is 857 g, and the dropping rate is 142.8% of the dropping rate in Table 1.

[0041] Sampling and testing revealed that the average thickness of the polymer gradient interface layer on the modified synthetic mica powder was 497 nm.

[0042] Preparation Example 10 A modified synthetic mica powder, the specific preparation process of which is as follows: 1 kg of synthetic mica powder with a thickness of 1 μm and a planar size of 25 μm was dispersed in 5 kg of 90 wt% ethanol aqueous solution. The mixture was ultrasonically treated at 500 W for 30 min to ensure full dispersion. Then, 0.05 kg of aminopropyltriethoxysilane was added at 280 rpm and mixed evenly. The pH of the reaction system was adjusted to 5.5 with acetic acid. The temperature was then raised to 80 °C and refluxed at 280 rpm for 6 h. After the reaction was completed, the mixture was centrifuged and washed three times with ethanol until the supernatant was colorless. The resulting solid was then dried under vacuum at 80°C to obtain modified synthetic mica powder.

[0043] Example 1 A high-wear-resistant and high-resilience forefoot shoe material, the raw materials of which are rubber matrix, reinforcing filler, flexible reinforcing phase, sulfur, accelerator, activator and antioxidant.

[0044] The rubber matrix is ​​a blend of natural rubber and neodymium-based cis-butadiene rubber in a mass ratio of 60:40.

[0045] The reinforcing filler was the modified synthetic mica powder prepared in Preparation Example 1.

[0046] The flexible reinforcing phase is thermoplastic polyurethane, which forms a three-dimensional nanofiber network in situ in the rubber matrix through a shear field, and the fibers in the three-dimensional nanofiber network are preferentially oriented along the processing direction.

[0047] The preparation method of high abrasion resistance and high rebound forefoot shoe material is as follows: (1) S1 Mixing 6 kg of natural rubber and 4 kg of neodymium-based butadiene rubber were added to a mixer preheated to 70°C and plasticized at 30 rpm for 2 minutes at 70°C. Then add 3.5 kg of surface-modified synthetic mica powder, 0.5 kg of zinc oxide, 0.15 kg of stearic acid, 0.1 kg of antioxidant RD and 0.1 kg of antioxidant 4020 to the internal mixer; Increase the rotor speed to 60 rpm and set the mixing chamber temperature to 140℃. Mix for 4 minutes under these conditions. Add 2.2 kg of hot plastic polyurethane particles, continue to maintain the rotor speed of 60 rpm and the mixing temperature of 140℃, and mix for 3 min; The evenly mixed rubber compound is discharged from the internal mixer to obtain a rubber compound; the rubber compound is placed at room temperature and cooled to room temperature for standby; (2) S2 orientation and fiber formation The front roller temperature of the two-roll open mill is set to 140℃, the rear roller temperature is set to 135℃, and the roller gap is adjusted to 1.0 mm; The rubber compound obtained in step S1 is subjected to repeated thin pass operation on the open mill, and the rubber compound is continuously passed through the roller gap, folded, and passed through again. This process is repeated 10 times, during which the shear rate experienced by the rubber compound is about 1200 s⁻¹, and the surface change of the rubber compound is observed (during the preparation process of Example 1, it can be observed that as the number of thin passes increases, the surface of the rubber compound gradually becomes smooth and a bright orientation gloss appears); The roller gap is adjusted to 2.0 mm to form a wrapped roller state of the rubber compound, 0.2 kg of sulfur and 0.12 kg of accelerator NS are uniformly scattered on the rubber compound, and the left and right knives are each cut 3 times to ensure uniform dispersion of the vulcanizing agent, and then the sheet is quickly cut off within 1 min to obtain a rubber sheet; (3) S3 vulcanization and shaping The rubber sheet obtained in step S2 is cut and filled into the mold cavity of the preheated to 150℃ shoe sole.

[0048] The mold is placed in a flat vulcanizing machine and vulcanized at 150℃ and a pressure of 15 MPa, and the vulcanization time is 15 min; After vulcanization is completed, the mold is immediately demolded, and the obtained forefoot shoe material is naturally cooled to room temperature at room temperature to obtain a forefoot shoe material.

[0049] Example 2 A high-wear-resistance high-rebound forefoot shoe material, which is different from Example 1 in that the modified synthetic mica powder is prepared according to Preparation Example 10.

[0050] Example 3 A high-wear-resistance high-rebound forefoot shoe material, which is different from Example 1 in that the modified synthetic mica powder is prepared according to Preparation Example 2.

[0051] Example 4 A high-wear-resistance high-rebound forefoot shoe material, which is different from Example 1 in that the modified synthetic mica powder is prepared according to Preparation Example 3.

[0052] Example 5 A high-wear-resistance high-rebound forefoot shoe material, which is different from Example 1 in that the modified synthetic mica powder is prepared according to Preparation Example 4.

[0053] Example 6 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the modified synthetic mica powder is prepared from Preparation Example 5.

[0054] Example 7 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the modified synthetic mica powder is prepared from Preparation Example 6.

[0055] Example 8 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the modified synthetic mica powder is prepared from Preparation Example 7.

[0056] Example 9 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the modified synthetic mica powder is prepared from Preparation Example 8.

[0057] Example 10 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the modified synthetic mica powder is prepared from Preparation Example 9.

[0058] Example 11 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the rubber matrix is natural rubber.

[0059] Example 12 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the rubber matrix is neodymium-based butadiene rubber.

[0060] Example 13 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the rubber matrix is a mixture of natural rubber and neodymium-based butadiene rubber at a mass ratio of 35:65.

[0061] Example 14 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the rubber matrix is a mixture of natural rubber and neodymium-based butadiene rubber at a mass ratio of 50:50.

[0062] Example 15 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the rubber matrix is a mixture of natural rubber and neodymium-based butadiene rubber at a mass ratio of 70:30.

[0063] Example 16 A high wear-resistance and high resilience forefoot shoe material, which differs from Example 1 in that the rubber matrix is a mixture of natural rubber and neodymium-based butadiene rubber at a mass ratio of 88:12.

[0064] Example 17 A high wear resistance and high resilience forefoot shoe material, which is different from example 1 in that the amount of raw materials is as follows: 6 kg of natural rubber, 4 kg of neodymium-based butadiene rubber, 3 kg of surface modified synthetic mica powder, 0.3 kg of zinc oxide, 0.1 kg of stearic acid, 0.75 kg of antioxidant RD, 0.75 kg of antioxidant 4020, 2 kg of thermoplastic polyurethane particles, 0.2 kg of sulfur and 0.5 kg of accelerator NS.

[0065] Example 18 A high wear resistance and high resilience forefoot shoe material, which is different from example 1 in that the amount of raw materials is as follows 6 kg of natural rubber, 4 kg of neodymium-based butadiene rubber, 4.2 kg of surface modified synthetic mica powder, 1.5 kg of zinc oxide, 0.5 kg of stearic acid, 0.15 kg of antioxidant RD, 0.15 kg of antioxidant 4020, 2.5 kg of thermoplastic polyurethane particles, 0.2 kg of sulfur and 0.2 kg of accelerator NS.

[0066] Comparative example 1 A high wear resistance and high resilience forefoot shoe material, which is different from example 1 in that the amount of raw materials is as follows

[0067] Comparative example 2 A high wear resistance and high resilience forefoot shoe material, which is different from example 1 in that the amount of raw materials is as follows

[0068] Comparative example 3 A high wear resistance and high resilience forefoot shoe material, which is different from example 1 in that the amount of raw materials is as follows

[0069] Comparative example 4 A high wear resistance and high resilience forefoot shoe material, which is different from example 1 in that the amount of raw materials is as follows S2: Set the roll temperature of the open mill to 80°C, adjust the roll gap to 3.8 mm, pass the masterbatch obtained in S1 through the roll gap twice on the open mill, only preheat and initially press the sheet, and form a thick sheet blank with uniform thickness; Adjust the roll gap to 2.0 mm to make the rubber wrap the roll, evenly sprinkle 0.2 kg of sulfur and 0.12 kg of accelerator NS on the rubber, mix for no more than 3 min in the left-right cutter, winding and turning mode to ensure that the vulcanizing agent is initially dispersed evenly, and then press the rubber mixed with the vulcanizing agent to obtain a flat rubber sheet; The film is cut into a shape and weight matching the forefoot outsole mold cavity as a preform blank; S3: The preform blank obtained in S2 is filled into the forefoot outsole mold cavity preheated to 150°C; The mold is placed in a flat vulcanization machine and vulcanized at 150°C and a pressure of 15 MPa, with a vulcanization time of 15 min (at this high temperature and high pressure, the thermoplastic polyurethane melts and forms fibers in situ under the action of pressure, but due to the lack of directional shear, the fibers will be disorganized and randomly distributed); After vulcanization is completed, the mold is immediately demolded, and the shoe material is naturally cooled at room temperature to obtain a forefoot shoe material.

[0070] Comparative Example 5 A high-wear-resistance high-resilience forefoot shoe material, which differs from Example 1 in that the reinforcing filler is a mixture of carbon black and white carbon black in a mass ratio of 1:1.

[0071] The forefoot shoe materials of Examples 1-16 and Comparative Examples 1-5 are tested, and the test items are as follows.

[0072] Wear resistance: Akron abrasion amount test according to GB / T 1689.

[0073] Resilience: Resilience value test according to GB / T 1681.

[0074] Strength: Tear strength test according to GB / T 529.

[0075] Hardness: Shore A hardness test according to GB / T 531.1.

[0076] The test results are shown in Table 2 below.

[0077] Table 2. Test results of Examples 1-16 and Comparative Examples 1-5

[0078] Comparative Example 1 and Comparative Examples 1-2: In Example 1, the flexible reinforcing phase is thermoplastic polyurethane, which is first uniformly dispersed in the rubber matrix in S1, and then preferentially oriented to form primary fibers under the action of directional shear and pressure in S2; In Comparative Example 1, no flexible reinforcing phase is contained, and only reinforcing fillers are used for reinforcement; In Comparative Example 2, the melting point of the thermoplastic polyurethane is greater than the process temperature of the double-roll open mill in S2, and the thermoplastic polyurethane does not melt and draw; The results of the test show that the abrasion resistance of Example 1 is significantly better than that of Comparative Examples 1-2; the rebound value of Example 1 is better than that of Comparative Examples 1-2; the tear strength of Example 1 is significantly better than that of Comparative Example 12; and the Shore A hardness of Example 1 is reduced after the flexible reinforcing phase is adjusted, and the material is softer and more comfortable.

[0079] The reason is that the synergistic effect between the oriented three-dimensional nanofiber network formed in situ by the thermoplastic polyurethane and the reinforcing filler in Example 1.

[0080] The synthetic mica powder itself has high hardness, and when it is arranged in order with its plane parallel to the surface of the sole, it is like a superimposed structure on the surface of the material. The synthetic mica powder can directly bear friction to improve the abrasion resistance by parallel arrangement, and can also consume energy by deflecting and segmenting the crack path, thereby significantly enhancing the tear resistance of the material. The three-dimensional nanofiber network of thermoplastic polyurethane throughout the rubber matrix can dissipate energy through fiber stretching and interfacial sliding, and inhibit crack propagation by its bridging effect, thereby improving the tear strength. At the same time, the three-dimensional nanofiber network of thermoplastic polyurethane can quickly recover after deformation, so that the material maintains high rebound. Under the synergistic effect of the two: The three-dimensional nanofiber network of thermoplastic polyurethane penetrates the material and "binds" the synthetic mica powder and "anchors" it on the rubber matrix, enhancing the bonding strength of the platelets and the matrix, preventing the platelets from being "prised up" and falling off in friction. Even if the local matrix is worn, the platelets can be kept in place for a longer time under the pulling of the three-dimensional nanofiber network, and continue to play a role in wear resistance. The parallelly arranged platelets provide a solid "anchor point" for the three-dimensional nanofiber network. When the fibers are stretched, the stress can be effectively transmitted to the platelets through the gradient interfacial layer, avoiding the concentration of stress at the fragile interface. This maximizes the reinforcing efficiency of the thermoplastic polyurethane fibers. And when external stress attacks, the three-dimensional nanofiber network first elastically deforms to dissipate part of the energy; if the stress is greater, a crack is generated, and the platelets will force the crack to deflect, dissipating energy again. At the same time, the bridging effect of the thermoplastic polyurethane fibers begins to take effect, further preventing crack propagation. The multi-stage energy dissipation and synergistic defense mechanism allows the material to absorb a large amount of energy before failure, thereby exhibiting high wear resistance and toughness.

[0081] In combination with Comparative Examples 3-4, in Comparative Example 3, existing formed polyurethane fibers are directly used to replace the thermoplastic polyurethane particles; and in Comparative Example 4, no high directional shear is applied to the mixing glue during preparation, and the formed primary fibers are disordered.

[0082] The abrasion amount of Comparative Example 3 is lower than that of Comparative Examples 1-2, and the rebound value and tear strength of Comparative Example 3 are higher than those of Comparative Examples 1-2. It can be seen that the thermoplastic polyurethane preformed fiber has a certain reinforcing effect, but it is not as good as the three-dimensional nanofiber network formed in situ. The dispersion is uneven and the interface is poor, and it cannot achieve the effect of Example 1.

[0083] The abrasion amount of Comparative Example 4 is lower than that of Comparative Example 1-3, but its tear strength and rebound are still significantly lower than those of Example 1. It is verified that the orientation of the three-dimensional nanofiber network of the thermoplastic polyurethane fiber is also the key when the synergistic effect between the three-dimensional nanofiber network of the thermoplastic polyurethane fiber and the synthetic mica powder affects the rebound value and tear strength.

[0084] Therefore, through the synergistic effect of the three of “in-situ formation”, “preferential orientation” and “flexible network”, a unique reinforcing structure with firm combination, uniform distribution and controllable reinforcing direction is constructed in the rubber matrix, realizing the transition from single “rigid particle dispersion reinforcement” to composite “flexible fiber network reinforcement”. The front foot palm shoe material has high wear resistance, high rebound and high toughness.

[0085] Comparing Comparative Example 2 and Comparative Example 5, the Akron abrasion amount of Example 2 is less than that of the comparative example. The wear resistance of the carbon black and white carbon black fillers applied in the thermoplastic polyurethane three-dimensional nanofiber network of the front foot palm shoe material of the application is not as good as that of the synthetic mica powder.

[0086] Comparing Example 1 and Example 2, the reinforcing material used in Example 1 is modified synthetic mica powder, and a polymer gradient interface layer is constructed on the surface thereof; the reinforcing material used in Example 2 is only a synthetic mica powder modified by a surface silane coupling agent.

[0087] The Shore A hardness of Example 1 and Example 2 is similar, but the Akron abrasion amount of Example 1 is less than that of Example 2, and the rebound value and tear strength of Example 1 are greater than those of Example 2. Therefore, the modified synthetic mica powder with a polymer gradient interface layer is selected in the application. The polymer gradient interface layer can effectively smooth stress transfer and avoid interface stress concentration, thereby significantly enhancing the interface bonding strength. Combined with “lamellar orientation”, the interface compatibility problem of the rigid filler and the rubber matrix is solved, and the reinforcing efficiency of the filler is maximized, and the wear resistance and toughness are also enhanced.

[0088] Comparative Example 1 and Examples 3-6 differ in that the size specifications of the synthetic mica powder used in the preparation of the modified synthetic mica powder are different. In the test results, the Akron abrasion amount of Example 1, Example 4, and Example 5 is lower than that of Example 3 and Example 6; the rebound value of Example 1, Example 4, and Example 5 is greater than that of Example 6, and the rebound value of Example 5 is equal to that of Example 3; the tear strength of Example 1, Example 4, and Example 5 is greater than that of Example 3 and Example 6; the Shore A hardness of Example 1 and Examples 3-6 is similar, so the aspect ratio of the synthetic mica powder in the present application is 20-30, which is relatively optimal.

[0089] Comparative Example 1 and Examples 7-10 differ in that the thickness of the polymer gradient interface layer of the modified synthetic mica powder is different. In Example 7, Example 8, Example 1, Example 9, and Example 10, the thickness of the polymer gradient interface layer gradually increases, the Akron abrasion amount first decreases and then increases, the rebound value gradually increases, and the tear strength first increases and then decreases. Therefore, the thickness of the polymer gradient interface layer in the present application is 300-400 nm, which is relatively optimal.

[0090] In combination with Example 1 and Examples 11-16, the difference is that the rubber matrix used is different. The Akron abrasion amount of Example 1, Example 14, and Example 15 is relatively low, and the rebound value of Example 1, Example 14, and Example 15 is relatively high. Therefore, in the present application, the rubber matrix is composed of natural rubber and neodymium-based butadiene rubber, and the mass ratio of the amount of natural rubber to the amount of neodymium-based butadiene rubber is (50-70):(30-50), which is relatively optimal.

[0091] In combination with Examples 17 and 18, it can be seen that the Akron abrasion amount, rebound value, and tear strength of Examples 17 and 18 are all at a relatively optimal level compared with Comparative Examples 1-4. Therefore, in the present application, the components of the forefoot shoe material are controlled to be 100 parts of rubber matrix, 30-42 parts of reinforcing filler, 20-25 parts of flexible reinforcing phase, 2 parts of sulfur, 0.5-2 parts of accelerator, 4-7 parts of active agent, and 1.5-3 parts of antioxidant, all in terms of weight parts, which is relatively optimal.

[0092] Example 19 A shoe, the forefoot outer sole part of which is made of a high-wear-resistance and high-rebound forefoot shoe material, and the high-wear-resistance and high-rebound forefoot shoe material is one of Examples 1-18.

[0093] The specific embodiments are merely an explanation of the present application, and are not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, and the modifications are protected by the patent law as long as they are within the scope of the present application.

Claims

1. A highly wear-resistant and highly resilient forefoot shoe material, characterized in that, It contains the following components by weight: 100 parts of rubber matrix, 30-42 parts of reinforcing filler 20-25 parts of flexible reinforcing phase 2 parts sulfur Accelerator 0.5-2 parts, Surfactant 4-7 parts, Anti-aging agent 1.5-3 parts, The reinforcing filler is synthetic mica powder; The flexible reinforcing phase is thermoplastic polyurethane, which forms a three-dimensional nanofiber network in situ in the rubber matrix through a shear field, and the fibers in the three-dimensional nanofiber network are preferentially oriented along the processing direction.

2. The high abrasion-resistant and high-resilience forefoot shoe material according to claim 1, characterized in that, The synthetic mica powder is a modified synthetic mica powder. A polymer gradient interface layer is constructed on the surface of the modified synthetic mica powder. The inner side of the polymer gradient interface layer consists of rigid segments that are strongly chemically bonded to the lamellar surface, while the outer side consists of flexible segments that are well compatible with the rubber matrix. The plane of the synthetic mica powder is parallel to the macroscopic surface orientation of the forefoot shoe material.

3. The high abrasion-resistant and high-resilience forefoot shoe material according to claim 2, characterized in that, The aspect ratio of the synthetic mica powder is 20-30.

4. The high abrasion-resistant and high-resilience forefoot shoe material according to claim 2, characterized in that, The polymer gradient interface layer is a methyl methacrylate-n-butyl acrylate copolymer grafted with a silane coupling agent, and its thickness is 300-400 nm.

5. The high abrasion-resistant and high-resilience forefoot shoe material according to claim 1, characterized in that, The rubber matrix is ​​composed of natural rubber and neodymium-based cis-butadiene rubber.

6. The high abrasion-resistant and high-resilience forefoot shoe material according to claim 5, characterized in that, The mass ratio of natural rubber to neodymium-based cis-butadiene rubber is (50-70):(30-50).

7. A method for preparing a high abrasion-resistant and high-resilience forefoot shoe material according to any one of claims 1-6, characterized in that, Includes the following steps: S1 Mixing: The rubber matrix, reinforcing filler, thermoplastic polyurethane particles and other additives are mixed evenly in an internal mixer at 140-160℃ to obtain a compound, wherein the melting point of the thermoplastic polyurethane particles is lower than the mixing temperature. S2 Orientation and Fiber Formation: The compound obtained in step S1 is subjected to multiple thin-pass and calendering processes on an open mill and a calender, with the roll temperature controlled at 130-150℃. A shear field with a shear rate of not less than 1000s⁻¹ is applied by adjusting the roll gap to obtain the film. S3 Vulcanization and Shaping: The rubber sheet processed in step S2 is vulcanized to obtain the forefoot shoe material.

8. A shoe, characterized in that, Its forefoot outsole portion is made of a highly abrasion-resistant and highly resilient forefoot shoe material as described in any one of claims 1-6.

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