Anti-skid mute material for shoe sole and preparation method of anti-skid mute material

Abstract

The invention belongs to the technical field of high polymer material processing and functionalization application, and particularly relates to an anti-skid mute material for shoe soles and a preparation method of the anti-skid mute material. The invention aims to solve the problem of conflict among the skid resistance, high resilience, softness and silence characteristics of the current sole skid-resistant and silence material. Monodisperse W / O / W double emulsion droplets are prepared and cured to form silicon rubber hollow microspheres with uniform wall thickness, and a polycaprolactone polymer brush layer is grafted on the surface of the microspheres in situ through a ring-opening polymerization method; the preparation method comprises the following steps: preheating high-damping thermoplastic polyurethane particles, sequentially adding the layered double-metal hydroxide nanosheets and the modified microspheres, mixing at low temperature, adding the polyethylene fibers and the auxiliary agent, and carrying out melt blending to obtain the material, and the material has the characteristics of high wetland friction coefficient, excellent rebound rate, low ground contact noise and the like.

Description

Technical Field

[0001] This invention belongs to the field of polymer material processing and functional application technology, specifically relating to an anti-slip and sound-absorbing material for shoe soles and its preparation method. Background Technology

[0002] With advancements in materials science and rising consumer demands for superior wearing experiences, modern footwear materials are evolving towards multi-functionality, characterized by lightweight construction, high resilience, enhanced slip resistance, and improved comfort and quiet operation (CN121179690A). Thermoplastic polyurethane (TPU), due to its excellent abrasion resistance, mechanical strength, and recyclability, has gradually replaced traditional vulcanized rubber and ethylene vinyl acetate (EVA), becoming the mainstream choice for high-end footwear materials. In particular, expanded thermoplastic polyurethane (E-TPU) materials prepared using supercritical fluid foaming technology have achieved great success in the field of athletic shoe midsoles due to their outstanding energy return performance.

[0003] However, in practical applications, existing TPU foam shoe materials face several irreconcilable performance conflicts, mainly in the following three aspects:

[0004] (1) The contradiction between anti-slip properties and softness and quietness: Traditional anti-slip mechanisms rely on the high hardness and surface roughness of materials to provide mechanical interlocking force. In order to obtain good wet grip, it is usually necessary to use rubber with high hardness or add hard particles, which often leads to a large impact noise when the sole touches the ground. On the contrary, in order to achieve a quiet effect, the material needs to have low modulus and high damping characteristics to absorb sound wave energy, but this will cause the material to "slip" on wet surfaces because it cannot pierce the water film.

[0005] (2) The contradiction between high rebound and damping shock absorption: Sports shoe soles require high rebound to improve athletic performance, which requires the material to quickly release the stored elastic potential energy after deformation. However, quietness and shock absorption performance essentially depend on energy dissipation, that is, reducing vibration and sound wave propagation by converting mechanical energy into heat energy. Although E-TPU material has a rebound rate of over 70%, its low damping characteristics make it less effective at suppressing high-frequency impact noise, and it is prone to generating high-frequency friction noise when walking.

[0006] To address these issues, researchers have attempted to add functional fillers to the TPU matrix. For example, hollow glass microspheres have been introduced to reduce weight and provide some acoustic barrier properties. However, inorganic glass microspheres are brittle and easily break during extrusion and foaming. Furthermore, their rigid surfaces have poor adhesion to the flexible TPU matrix, leading to interfacial delamination after repeated bending and severely reducing fatigue resistance. On the other hand, while ultra-high molecular weight polyethylene fibers possess extremely low coefficients of friction and high wear resistance, making them ideal microscopic anti-slip reinforcements, their non-polar surface makes them difficult to disperse in polar TPU matrices and they are prone to agglomeration during melt blending.

[0007] In summary, there is an urgent need for a new shoe sole material that simultaneously achieves excellent wet slip resistance, high rebound, and quietness, as well as a new method for its preparation. Summary of the Invention

[0008] This invention provides an anti-slip and sound-absorbing material for shoe soles and its preparation method. It aims to overcome the conflict between these properties of traditional shoe sole materials by combining anti-slip properties with high resilience, softness and quietness through structural design and process innovation.

[0009] The specific technical solution is as follows: An anti-slip and sound-absorbing material for shoe soles and its preparation method are as follows: S1: Double emulsion preparation.

[0010] S11: Sorbitol monooleate is dissolved in deionized water to obtain an internal aqueous phase solution; methyl vinyl silicone rubber prepolymer is mixed with a platinum catalyst to obtain an oil phase.

[0011] S12: The aqueous phase solution prepared in S11 is added to the oil phase prepared in S11, and shear emulsification is performed to obtain the primary emulsion.

[0012] S13: Dissolve polysorbate 20 and polyvinyl alcohol in deionized water to obtain an external aqueous phase solution; wet the membrane tube with the primary emulsion prepared in S12, and then place it in the emulsification device, with the external aqueous phase placed in the outer chamber.

[0013] S14: The primary emulsion prepared in S12 is pressurized and extruded, and then separated from the membrane pores under the flushing of the external aqueous phase to obtain a double emulsion.

[0014] S2: Preparation of hollow microspheres grafted with silicone rubber.

[0015] S21: Add the platinum catalyst to the double emulsion prepared in S14, stir and solidify, centrifuge and wash, and dry to obtain silicone rubber hollow microspheres.

[0016] S22: Disperse the silicone rubber hollow microspheres prepared in S21 in ethanol, irradiate with ultraviolet light for 30 min, then add ε-caprolactone and stannous octoate, stir, cool to room temperature, centrifuge, wash, dry, and sieve to obtain surface-grafted silicone rubber hollow microspheres.

[0017] S3: Pre-dispersion and blending.

[0018] S31: Disperse layered bimetallic hydroxide nanosheets in a mixed solvent of ethanol and water, add KH-550, stir, dry, and pulverize to obtain surface-modified layered bimetallic hydroxide nanosheets.

[0019] S32: The dried high-damping thermoplastic polyurethane is stirred and heated to 90°C, and the surface-modified layered bimetallic hydroxide nanosheets prepared in S31 are added. Then, the surface-grafted silicone rubber hollow microspheres prepared in S22 are added and stirred at high speed to obtain the pre-dispersed material.

[0020] S33: The pre-dispersed material prepared in S32, poly(p-phenylene terephthalamide) fiber, antioxidant 1010, calcium stearate, and silicone masterbatch are mixed and stirred, melt-extruded, cooled and solidified to obtain an anti-slip and sound-absorbing material.

[0021] Furthermore, the internal aqueous phase solution described in S11 has a mass concentration of 1 to 2%.

[0022] The methyl vinyl silicone rubber prepolymer described in S11 has a mass ratio of 100:0.4 to the platinum catalyst.

[0023] The shear emulsification described in S12 has the following parameter settings: rotation speed 10000~15000rpm, duration 2~4min.

[0024] The primary emulsion described in S12 has an internal aqueous phase to oil phase mass ratio of 1:5.

[0025] The external aqueous phase solution described in S13 has a concentration of 2-4%, wherein polysorbate 20 is 1.5-2.5% and polyvinyl alcohol is 0.5-1.5%.

[0026] The pressure extrusion described in S14 has the following parameter settings: pressure 20-80 kPa, temperature 20-25℃.

[0027] The dual emulsion described in S14 has an external aqueous phase and a primary emulsion mass ratio of 10:1.

[0028] Furthermore, the platinum catalyst described in S21 is added in such an amount that the concentration of platinum catalyst in the aqueous phase is 0.05%.

[0029] The stirring and curing described in S21 has the following parameters: temperature 65-75℃, rotation speed 150-250rpm, and duration 3-5h.

[0030] The centrifugal washing described in S21 uses deionized water and is set with the following parameters: speed 3000 rpm, duration 5 min, and number of cycles 5.

[0031] The ε-caprolactone described in S22 is 2 to 4 times the mass of the silicone rubber hollow microspheres.

[0032] The stannous octoate described in S22 has a mass of 0.2 to 0.5% of the mass of ε-caprolactone.

[0033] The stirring described in S22 has the following parameters: temperature 110-120℃, speed 200-400rpm, and duration 6-10h.

[0034] The centrifugal washing described in S22 uses tetrahydrofuran washing, with the following parameters: speed 4000 rpm, duration 5 min.

[0035] The surface-grafted silicone rubber hollow microspheres described in S22 have a particle size of 40–60 µm.

[0036] Furthermore, the layered bimetallic hydroxide nanosheets described in S31 are organically modified Mg-Al or Zn-Al layered hydroxides with a sheet diameter of 20–100 nm and a sheet thickness of 1–5 nm.

[0037] The KH-550 described in S31 has a mass of 1 to 3% of the mass of the layered bimetallic hydroxide nanosheets.

[0038] The stirring described in S31 has the following parameters: temperature 60-70℃, pH 4-5, rotation speed 200-400rpm, and duration 3-5h.

[0039] The high-speed stirring described in S32 has the following parameters: temperature 70-80℃, speed 800-1200rpm, and duration 10-15min.

[0040] The poly(p-phenylene terephthalamide) fiber described in S33 has a length of 3-6 mm and a diameter of 10-30 µm.

[0041] The melt extrusion described in S33 has the following parameter settings: the temperatures of the feeding zone, melting zone, mixing zone, and homogenization zone are 150-160℃, 170-180℃, 180-190℃, and 175-185℃, respectively; the die head temperature is 170-180℃; and the screw speed is 200-250 rpm.

[0042] The anti-slip and sound-absorbing material described in S33 comprises, based on 100 parts of high-damping thermoplastic polyurethane, 3-15 parts of surface-modified layered bimetallic hydroxide nanosheets, 7-30 parts of surface-grafted silicone rubber hollow microspheres, 4-20 parts of poly(p-phenylene terephthalamide) fiber, 1-2 parts of antioxidant 1010, 1.5-3 parts of calcium stearate, and 2-4 parts of silicone masterbatch.

[0043] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention achieves excellent anti-slip performance while maintaining softness and high elasticity through multi-scale composite design, and the material has good vibration reduction and noise reduction capabilities, significantly reducing the impact noise of walking.

[0044] 2. This invention improves the friction coefficient of the material by adding LDH nanosheets and a microsphere-fiber composite structure. Attached Figure Description

[0045] Figure 1 This is a flowchart illustrating the manufacturing process of an anti-slip and sound-absorbing material used in shoe soles.

[0046] Figure 2 This is a comparison FTIR image of the hollow silicone rubber microspheres prepared in Example 1 and the surface-grafted hollow silicone rubber microspheres.

[0047] Figure 3 This is a microscopic morphology diagram of the anti-slip and sound-absorbing material finally prepared in Example 1. Detailed Implementation

[0048] The following embodiments further explain and illustrate the technical solutions of the present invention. It should be specifically noted that each specific embodiment is a concretization and explanation of the technical solution and should not be considered as a limitation on the scope of protection of the present invention. Those skilled in the art still have the right to modify the technical solutions of these embodiments and make equivalent substitutions for some or all of the technical features, and these modifications or substitutions do not change the essence of the corresponding technical solutions, nor do they cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions described in the present invention.

[0049] This invention proposes an anti-slip and sound-absorbing material for shoe soles and its preparation method, resolving the conflict between anti-slip properties and high resilience, softness, and sound-absorbing characteristics in existing shoe sole materials. It provides a shoe sole material that combines excellent anti-slip performance, high resilience, and good shock absorption and noise reduction. (See attached diagram) Figure 1 The image shows an anti-slip and sound-absorbing material for shoe soles and its preparation method. The detailed technical solution is as follows: 1. Preparation of dual emulsions Sorbitol monooleate was dissolved in deionized water to obtain an inner aqueous phase solution; methyl vinyl silicone rubber prepolymer was mixed with a platinum catalyst to obtain an oil phase; the inner aqueous phase solution was added to the oil phase and sheared to emulsify, resulting in a primary emulsion; polysorbate 20 and polyvinyl alcohol (PVA) were dissolved in deionized water to obtain an outer aqueous phase solution; the membrane tube was wetted with the primary emulsion and then placed in an emulsification device, with the outer aqueous phase placed in the outer chamber; the primary emulsion was pressurized and extruded, and then detached from the membrane pores under the flushing of the outer aqueous phase, resulting in a dual emulsion.

[0050] In the presence of surfactants with low hydrophilic-lipophilic balance (HLB) values, high-speed shearing inputs mechanical energy to break down the inner aqueous phase (W1) into micron-sized or even submicron-sized droplets, which are then dispersed in the oil phase (O). Surfactant molecules rapidly adsorb onto the newly formed W1 / O interface, with their lipophilic tails extending into the oil phase and their hydrophilic heads anchored in the aqueous phase. By reducing interfacial tension and forming a kinetic energy barrier, they prevent the immediate aggregation of small droplets, thus forming a metastable primary emulsion with a relatively wide droplet size distribution in the inner phase. Under pressure, the primary W1 / O emulsion is pressed into the uniform pores of the SPG membrane. At the pore outlet, the dispersed phase (W1 / O) protrudes to form a spherical cap, and the flowing outer aqueous phase (W2) applies laminar shear force to the cap. When the shear force overcomes the interfacial tension between the W1 / O droplets and the continuous phase W2, the droplets are "cut off" and detached from the membrane pores. Because all membrane pores have uniform diameters and the shear field and pressure conditions experienced at each pore are highly consistent, the detached W1 / O droplets have an extremely narrow size distribution, avoiding the severe turbulence and uneven energy distribution in the high-speed shearing method, thus achieving monodispersity far superior to the traditional two-step method.

[0051] Polysorbate 20, as a small molecule emulsifier, can be quickly adsorbed onto the newly formed O / W2 interface, reducing the interfacial energy and preventing droplets from coalescing upon contact. PVA, as a high molecular surfactant, extends its long chains into the aqueous phase after adsorption at the interface, forming a thick steric hindrance layer, which improves the long-term kinetic stability of the emulsion and provides a guarantee for the subsequent thermosetting process that lasts for several hours.

[0052] 2. Preparation and modification of silicone rubber hollow microspheres Platinum catalyst was added to a double emulsion, stirred and cured, centrifuged, washed and dried to obtain silicone rubber hollow microspheres; the silicone rubber hollow microspheres were dispersed in ethanol, irradiated with ultraviolet light, and then ε-caprolactone and stannous octoate were added, stirred, cooled to room temperature, centrifuged, washed and dried, and sieved to obtain surface-grafted silicone rubber hollow microspheres.

[0053] The oil phase (O) of the dual emulsion contains a platinum catalyst and a crosslinkable silicone rubber prepolymer. When the system is heated to approximately 70°C, the platinum-catalyzed hydrosilylation reaction is activated, and the vinyl groups in the prepolymer react with the crosslinking agent, resulting in a three-dimensional network crosslinking process from the interface inwards within the shell space of the oil phase. The reaction is confined to the microscale of the O phase, ultimately forming an elastic crosslinked silicone rubber spherical shell that encapsulates the inner aqueous phase (W1). The outer aqueous phase (W2), acting as a continuous medium, provides channels for heat transfer and diffusion of reaction byproducts, while the polyvinyl alcohol and polysorbate 20 stabilizing layers ensure interfacial integrity during curing, preventing the spherical shell from sticking together or cracking. By using ultraviolet treatment, polar functional groups such as hydroxyl and carboxyl groups are introduced onto the surface of the silicone rubber spheres, providing sites for the grafting reaction. In anhydrous toluene, the surface-anchored hydroxyl groups react with the catalyst stannous octoate to form active centers. At high temperatures, the cyclic structure of the ε-caprolactone monomer is opened, and its ester groups react with the active centers, growing outward from the surface of the microspheres through chemical bonds, ultimately forming a polycaprolactone (PCL) polymer brush. One end of its molecular chain is firmly chemically bonded to the surface of the microspheres, while the other end extends freely to the outside, forming a flexible interface layer. This "soft brush" can significantly improve the compatibility between the hydrophobic silicone rubber and the subsequent TPU matrix, optimizing stress transfer and energy dissipation.

[0054] 3. Pre-dispersion and blending Layered double hydroxide (LDH) nanosheets were dispersed in a mixed solvent of ethanol and water, KH-550 was added, and the mixture was stirred, dried, and pulverized to obtain surface-modified LDH nanosheets. The dried high-damping thermoplastic polyurethane was stirred and heated to 90°C, and the surface-modified LDH nanosheets were added. Then, surface-grafted silicone rubber hollow microspheres were added, and the mixture was stirred at high speed. It was then mixed and stirred with poly(p-phenylene terephthalamide) fiber, antioxidant 1010, calcium stearate, and silicone masterbatch. The mixture was melt-extruded, cooled, and solidified to obtain an anti-slip and sound-absorbing material.

[0055] The modified LDH surface changes from hydrophilic to hydrophobic and oleophilic. Its long organic chains can interact with the high-damping thermoplastic polyurethane molecular chains through van der Waals forces. This strong interfacial force ensures that stress is efficiently transferred from the soft TPU matrix to the rigid LDH nanosheets, giving full play to its reinforcing effect, while also improving the interfacial adhesion of LDH under wet and slippery conditions.

[0056] In the low-temperature pre-dispersion stage, the "leather state" property of high-damping thermoplastic polyurethane above the glass transition temperature (Tg) and below the melting temperature is utilized. At this time, the surface of the high-damping thermoplastic polyurethane particles softens and becomes sticky, but the whole remains solid. LDH nanosheets and silicone rubber hollow microspheres are added sequentially and stirred at high speed. Under the action of mechanical force, they are forced into and anchored on the surface of the softened high-damping thermoplastic polyurethane particles, avoiding their re-agglomeration in the subsequent melt due to Brownian motion and high surface energy. It also avoids the risk of being instantly broken by the screw when directly put into the high-temperature and high-shear melt, thus protecting the complete spherical structure of the silicone rubber hollow microspheres. When the pre-composite particles enter the melting zone of the twin-screw extruder, the solid high-damping thermoplastic polyurethane core melts, and the fillers (LDH and microspheres) in the shell are released into the melt. The screw provides shearing and stretching, causing the LDH nanosheets to further peel off and disperse, forming a nanoscale interface and physical cross-linking network in the high-damping thermoplastic polyurethane matrix. The PCL brush layer on the surface of the silicone rubber microspheres undergoes chain diffusion and entanglement with the TPU melt, forming a strong interfacial bond. The nanosheets and microspheres no longer exist in isolation in the melt, but rather, through the "wetted" and "compatible" interface, they initially form an interconnected "hard-soft" biphase micro-network. The fibers are better dispersed under the conveying and shearing of the screw and acquire a certain orientation along the flow direction, thereby forming a high-strength, high-modulus macroscopic skeleton that runs through the aforementioned "hard-soft" micro-network, effectively transferring and dispersing stress.

[0057] Example 1 An anti-slip and sound-absorbing material for shoe soles and its preparation method are as follows:

[0058] S1: Double emulsion preparation.

[0059] S11: Sorbitol monooleate is dissolved in deionized water to obtain an internal aqueous solution with a mass concentration of 1.5%; methyl vinyl silicone rubber prepolymer is mixed with a platinum catalyst to obtain an oil phase. The mass ratio of methyl vinyl silicone rubber prepolymer to platinum catalyst is 100:0.4.

[0060] S12: The aqueous phase solution prepared in S11 is added to the oil phase prepared in S11, and shear emulsification is performed to obtain the primary emulsion. The shear emulsification parameters are set as follows: rotation speed 12500 rpm, duration 3 min; the mass ratio of the aqueous phase to the oil phase in the primary emulsion is 1:5.

[0061] S13: Polysorbate 20 and polyvinyl alcohol are dissolved in deionized water to obtain a 3% aqueous external phase solution; the membrane tube is wetted with the primary emulsion prepared in S12, and then placed in the emulsification device, with the aqueous external phase placed in the outer chamber. The composition of polysorbate 20 is 2%, and the composition of polyvinyl alcohol is 1%; the mass ratio of the aqueous external phase to the primary emulsion is 10:1.

[0062] S14: The primary emulsion prepared in S12 is subjected to pressure extrusion and then extruded from the membrane pores under the flushing action of the external aqueous phase to obtain a dual emulsion. The pressure extrusion parameters are set as follows: pressure 50 kPa, temperature 22℃.

[0063] S2: Preparation and modification of hollow silicone rubber microspheres.

[0064] S21: The platinum catalyst was added to the double emulsion prepared in S14, stirred and cured, washed with deionized water (3000 rpm, 5 min, 5 times), and dried to obtain silicone rubber hollow microspheres. The amount of platinum catalyst added was such that the concentration of platinum catalyst in the aqueous phase was 0.05%; the stirring and curing parameters were set as follows: temperature 70℃, stirring speed 200 rpm, and time 4 h.

[0065] S22: The silicone rubber hollow microspheres prepared in S21 were dispersed in ethanol and irradiated with ultraviolet light for 30 min. Then, ε-caprolactone and stannous octoate were added, stirred, cooled to room temperature, washed with tetrahydrofuran (4000 rpm for 5 min), dried, and sieved to obtain surface-grafted silicone rubber hollow microspheres. The ε-caprolactone content was 3 times the mass of the silicone rubber hollow microspheres; the stannous octoate content was 0.35% of the ε-caprolactone content; the stirring parameters were set as follows: temperature 115℃, rotation speed 300 rpm, and stirring time 8 h.

[0066] S3: Pre-dispersion and blending.

[0067] S31: Layered bimetallic hydroxide nanosheets were dispersed in a mixed solvent of ethanol and water, KH-550 was added, and the mixture was stirred, dried, and pulverized to obtain surface-modified layered bimetallic hydroxide nanosheets. The mass of KH-550 was 2% of the mass of the layered bimetallic hydroxide nanosheets. The stirring parameters were set as follows: temperature 65℃, pH 4.5, rotation speed 300 rpm, and stirring time 4 h.

[0068] S32: The dried high-damping thermoplastic polyurethane was stirred and heated to 90℃. The surface-modified layered bimetallic hydroxide nanosheets prepared in S31 were added, followed by the surface-grafted silicone rubber hollow microspheres prepared in S22. The mixture was stirred at high speed to obtain a pre-dispersed material. High-speed stirring parameters: temperature 75℃, speed 1000 rpm, duration 12.5 min.

[0069] S33: The pre-dispersed material prepared in S32, poly(p-phenylene terephthalamide) fiber, antioxidant 1010, calcium stearate, and silicone masterbatch are mixed and stirred, melt-extruded, and cooled and solidified to obtain an anti-slip and noise-reducing material. The melt extrusion parameters are set as follows: the temperatures of the feeding zone, melting zone, mixing zone, and homogenization zone are 155℃, 175℃, 185℃, and 180℃, respectively; the die head temperature is 175℃; and the screw speed is 230 rpm. The anti-slip and noise-reducing material is based on 100g of high-damping thermoplastic polyurethane, with 9g of surface-modified layered bimetallic hydroxide nanosheets, 18g of surface-grafted silicone rubber hollow microspheres, 12g of poly(p-phenylene terephthalamide) fiber, 1.5g of antioxidant 1010, 2.3g of calcium stearate, and 3g of silicone masterbatch.

[0070] Example 2 The composition and preparation process are the same as in Example 1, except that: In the preparation process, the mass concentration of the internal aqueous phase solution in S11 is 1%, and the other components are the same.

[0071] In step S12 of the preparation process, the shear emulsification parameters are set as follows: rotation speed 10000 rpm, duration 2 min, and other steps are the same.

[0072] In the S13 preparation process, the external aqueous phase solution has a concentration of 2%, of which polysorbate 20 is 1.5%, polyvinyl alcohol is 0.5%, and other components are the same.

[0073] In the S14 step of the preparation process, the pressure extrusion parameters are set as follows: pressure 20 kPa, temperature 20 °C, and other steps are the same.

[0074] The stirring and curing parameters in step S21 of the preparation process are set as follows: temperature 65℃, rotation speed 150rpm, duration 3h, and other steps are the same.

[0075] In the preparation process S22, the mass of ε-caprolactone is twice the mass of the silicone rubber hollow microspheres; the mass of stannous octoate is 0.2% of the mass of ε-caprolactone, and the other components are the same.

[0076] The stirring parameters in step S22 of the preparation process are set as follows: temperature 110℃, rotation speed 200rpm, duration 6h, and other steps are the same.

[0077] In the preparation process S31, the mass of KH-550 is 1% of the mass of the layered bimetallic hydroxide nanosheets, and the other components are the same.

[0078] The stirring parameters in step S31 of the preparation process are set as follows: temperature 60℃, pH 4, rotation speed 200rpm, duration 3h, and other steps are the same.

[0079] The high-speed stirring parameters in step S32 of the preparation process are set as follows: temperature 70℃, speed 800rpm, duration 10min, and other steps are the same.

[0080] In the S33 process of preparation, the melt extrusion parameters are set as follows: the temperatures of the feeding zone, melting zone, mixing zone, and homogenization zone are 150℃, 170℃, 180℃, and 175℃, respectively; the die head temperature is 170℃; the screw speed is 200 rpm; and the other steps are the same.

[0081] The anti-slip and sound-absorbing material in the S33 preparation process is based on 100g of high-damping thermoplastic polyurethane, 3g of surface-modified layered bimetallic hydroxide nanosheets, 7g of surface-grafted silicone rubber hollow microspheres, 4g of poly(p-phenylene terephthalamide) fiber, 1g of antioxidant 1010, 1.5g of calcium stearate, and 2g of silicone masterbatch, with other components being the same.

[0082] Example 3 The composition and preparation process are the same as in Example 1, except that: In the preparation process, the mass concentration of the internal aqueous phase solution in S11 is 2%, and the other components are the same.

[0083] In step S12 of the preparation process, the shear emulsification parameters are set as follows: rotation speed 15000 rpm, duration 4 min, and other steps are the same.

[0084] In the S13 preparation process, the external aqueous phase solution has a concentration of 4%, of which polysorbate 20 is 2.5%, polyvinyl alcohol is 1.5%, and other components are the same.

[0085] In the S14 step of the preparation process, the pressure extrusion parameters are set as follows: pressure 80 kPa, temperature 25℃, and other steps are the same.

[0086] The stirring and curing parameters in step S21 of the preparation process are set as follows: temperature 75℃, rotation speed 250rpm, duration 5h, and other steps are the same.

[0087] In the preparation process S22, the mass of ε-caprolactone is 4 times the mass of the silicone rubber hollow microspheres; the mass of stannous octoate is 0.5% of the mass of ε-caprolactone, and the other components are the same.

[0088] The stirring parameters in step S22 of the preparation process are set as follows: temperature 120℃, rotation speed 400rpm, duration 10h, and other steps are the same.

[0089] In the preparation process S31, the mass of KH-550 is 3% of the mass of the layered bimetallic hydroxide nanosheets, and the other components are the same.

[0090] The stirring parameters in step S31 of the preparation process are set as follows: temperature 70℃, pH 5, rotation speed 400rpm, duration 3-5h, and other steps are the same.

[0091] The high-speed stirring parameters in step S32 of the preparation process are set as follows: temperature 80℃, speed 1200rpm, duration 15min, and other steps are the same.

[0092] In the S33 process of preparation, the melt extrusion parameters are set as follows: the temperatures of the feeding zone, melting zone, mixing zone, and homogenization zone are 160℃, 180℃, 190℃, and 185℃, respectively; the die head temperature is 180℃; the screw speed is 250 rpm; and the other steps are the same.

[0093] The anti-slip and sound-absorbing material in the S33 preparation process is based on 100g of high-damping thermoplastic polyurethane, 15g of surface-modified layered bimetallic hydroxide nanosheets, 30g of surface-grafted silicone rubber hollow microspheres, 20g of poly(p-phenylene terephthalamide) fiber, 2g of antioxidant 1010, 3g of calcium stearate, and 4g of silicone masterbatch, with other components being the same.

[0094] Example 4 The composition and preparation process are the same as in Example 1, except that: In the preparation process S11, the mass concentration of the internal aqueous solution is 1.2%, the mass ratio of methyl vinyl silicone rubber prepolymer to platinum catalyst is 100:0.4, and other components are the same.

[0095] In step S12 of the preparation process, the shear emulsification parameters are set as follows: rotation speed 14000 rpm, duration 2.5 min, and other steps are the same.

[0096] In the S13 preparation process, the external aqueous phase solution has a concentration of 2.4%, of which polysorbate 20 is 1.7%, polyvinyl alcohol is 0.7%, and other components are the same.

[0097] In the S14 step of the preparation process, the pressure extrusion parameters are set as follows: pressure 65 kPa, temperature 24℃, and other steps are the same.

[0098] The stirring and curing parameters in step S21 of the preparation process are set as follows: temperature 74℃, rotation speed 1600rpm, duration 4.5h, and other steps are the same.

[0099] In the preparation process S22, the mass of ε-caprolactone is 3.5 times the mass of silicone rubber hollow microspheres; the mass of stannous octoate is 0.4% of the mass of ε-caprolactone, and other components are the same.

[0100] The stirring parameters in step S22 of the preparation process are set as follows: temperature 117℃, rotation speed 360rpm, duration 9h, and other steps are the same.

[0101] In the S31 preparation process, the layered bimetallic hydroxide nanosheets are Zn-Al, and the mass of KH-550 is 2.5% of the mass of the layered bimetallic hydroxide nanosheets, with other components being the same.

[0102] The stirring parameters in step S31 of the preparation process are set as follows: temperature 68℃, pH 4.8, rotation speed 390rpm, duration 3.5h, and other steps are the same.

[0103] The high-speed stirring parameters in step S32 of the preparation process were set as follows: temperature 72℃, speed 1100rpm, duration 11min, and other steps were the same.

[0104] In the S33 process of preparation, the melt extrusion parameters are set as follows: the temperatures of the feeding zone, melting zone, mixing zone, and homogenization zone are 158℃, 177℃, 181℃, and 182℃, respectively; the die head temperature is 178℃; the screw speed is 240 rpm; and the other steps are the same.

[0105] The anti-slip and sound-absorbing material in the S33 preparation process is based on 100g of high-damping thermoplastic polyurethane, 12g of surface-modified layered bimetallic hydroxide nanosheets, 28g of surface-grafted silicone rubber hollow microspheres, 6g of poly(p-phenylene terephthalamide) fiber, 1.2g of antioxidant 1010, 2.5g of calcium stearate, and 3.5g of silicone masterbatch, with other components being the same.

[0106] Comparative Example 1 The composition and preparation process are the same as in Example 1, except that: In step S2 of the preparation process, the surface-grafted silicone rubber hollow microspheres are removed, and unmodified silicone rubber microspheres are used instead. The other steps are the same.

[0107] Comparative Example 2 The composition and preparation process are the same as in Example 1, except that: In step S3 of the preparation process, layered bimetallic hydroxide nanosheets are removed, and an equal mass of high-damping thermoplastic polyurethane is added; the other steps are the same.

[0108] Samples were taken from the hollow silicone rubber microspheres prepared in S21 and the surface-grafted hollow silicone rubber microspheres prepared in S22 in Example 1. Infrared spectroscopy was performed using a Fourier transform infrared spectrometer. The surface-grafted hollow silicone rubber microspheres were centrifuged and washed with tetrahydrofuran (4000 rpm for 15 min), then dried to obtain sample A. The hollow silicone rubber microspheres were centrifuged and washed with deionized water, then dried to obtain sample B. The dried samples A and B were respectively mixed with dried potassium bromide and ground until the powder was uniform and free of particles. The powder was then compressed into tablets (10 MPa) using a tablet press. Spectroscopic acquisition was performed on the compressed tablets (range 4000–400 cm⁻¹). -1 (64 scans) Figure 2 As shown, in the range of 2850–2950 cm -1 In the region, the peak intensity of grafted microspheres should be significantly higher than that of ungrafted microspheres. This is because the PCL segment introduces a large number of methylene structures, demonstrating its chain growth at 1730 cm⁻¹. -1 A new, sharp absorption peak appears nearby, which is the stretching vibration peak of the ester carbonyl group in the PCL molecular chain. Since pure silicone rubber hollow microspheres do not contain carbonyl groups, this peak indicates that the grafting was successful. The peak is located in the range of 1000–1100 cm⁻¹. -1 and 1260cm -1 The sharp peaks appear nearby, which are symmetric deformation vibrations of methyl groups attached to silicon atoms.

[0109] Samples of the anti-slip and sound-absorbing material prepared in S3 of Example 1 were taken and subjected to SEM and TEM tests. For SEM testing: a portion of the sample was cut into strips of 5mm × 5mm × 2mm, immersed in liquid nitrogen for 20 minutes, sputter-coated with gold, and observed using a field emission scanning electron microscope (accelerating voltage 5kV, working distance 8mm). Figure 3 As shown in the left image, the spherical structure is obvious, and the broken parts of some spheres show a hollow structure, indicating that S1 and S2 successfully prepared hollow silicone rubber microspheres with a core-shell structure. The microspheres are uniformly dispersed in the matrix without obvious agglomeration, indicating that the pre-dispersion process is effective. In the high-magnification inset, the surface of the microspheres shows a layer of nanoscale "fluffy" rough texture, indicating that polycaprolactone has undergone good chain entanglement and physical cross-linking with the matrix, making the interface between the microspheres and the matrix blurred, with no obvious gaps or peeling, indicating good interfacial compatibility. TEM testing was performed: some samples were embedded in epoxy resin, and sections were prepared at -80℃ using a cryo-microtome equipped with a diamond scalpel. Observation was performed using a high-resolution transmission electron microscope (accelerating voltage 120kV). Figure 3 As shown in the right image, LDH appears as black needles or lines. The lines are mostly single or 3 to 5 parallel fine lines, rather than large black agglomerates. This indicates that LDH has achieved exfoliation or high intercalation. The uniformly dispersed nanosheets construct a rigid network that runs through the matrix, which can effectively bear stress and improve the anti-slip and mechanical properties of the material.

[0110] Based on Examples 1-4 and Comparative Examples 1-2, samples of the finally prepared anti-slip and sound-absorbing materials were taken for static and dynamic friction coefficient tests: Samples of the anti-slip and sound-absorbing materials (lower sample 80mm × 200mm, upper sample 60mm × 60mm) were placed in an environment of 23℃ and 50% relative humidity for 12 hours to equilibrate. The lower sample was then fixed flat on a horizontal test platform, and the upper sample completely covered the bottom surface of the slider (slider mass 200g) and secured with tape. A sliding test was conducted (speed 100mm / min, distance 60mm), and the maximum peak force (F) at the moment the slider began to move was recorded.s ), calculate the average force (F) of the slider during the uniform sliding phase. k Repeat 5 times and calculate the average.

[0111] Based on Examples 1-4 and Comparative Examples 1-2, samples of the finally prepared anti-slip and sound-absorbing materials were taken for rebound rate testing: Samples (diameter 29mm, height 12.5mm) were taken and placed in an environment with a temperature of 23℃ and a relative humidity of 50% for 12 hours to equilibrate. The sample was then placed flat and centered on the sample platform of a pendulum rebound hammer. The pendulum was set to 90° and released smoothly. At the moment when the pendulum rebounded to the highest point, the rebound angle value was accurately read from the scale. Each sample was repeated three times, and the average value was taken to calculate the rebound rate.

[0112] Based on Examples 1-4 and Comparative Examples 1-2, samples of the finally prepared anti-slip and sound-absorbing materials were taken and subjected to impact rebound noise tests: samples of the anti-slip and sound-absorbing materials (300mm×300mm, thickness 15mm) were taken and laid freely on a 40mm thick concrete slab. The samples were tested in a semi-anechoic chamber using a standard impact hammer (mass 500g) (height 300mm). Five samples were selected for each group and 10 impact tests were performed on the same sample. The average value was calculated.

[0113] The specific test results are shown in Table 2. Figure 2 , Figure 3 As shown: Table 2 Comparison of core performance of Examples 1-4 and Comparative Examples 1-2

[0114] The comparison results above show that Example 1 has the best overall performance. The moderate internal water phase concentration and shear speed formed hollow microspheres with uniform size and suitable wall thickness, ensuring good resilience and deformation recovery. The surface-grafted ε-caprolactone enhanced the interfacial bonding between the silicone rubber microspheres and the TPU matrix, enabling effective stress transfer. At the same time, the hollow structure of the microspheres provided excellent buffering and sound absorption performance. The surface-modified layered bimetallic hydroxide nanosheets and fibers formed a multi-scale reinforcing network, which improved the coefficient of friction while maintaining the overall softness of the material. This shows that Example 1 successfully solved the current conflict between anti-slip and high resilience, softness and quietness. The overall performance of Examples 2 to 4 was slightly lower than that of Example 1, but still maintained a high level. This shows that excellent performance balance was still achieved under a large range of parameter variations. Comparative Example 1 used unmodified silicone rubber microspheres, which had poor compatibility with the TPU matrix and weak interfacial bonding, resulting in a reduced coefficient of friction, resilience, and impact rebound noise performance. Comparative Example 2 removed the layered bimetallic hydroxide nanosheets, resulting in insufficient anti-slip performance and weakened sound absorption and vibration reduction capabilities.

[0115] In summary, it is clear from the above embodiments and comparative examples that the anti-slip and noise-reducing material for shoe soles provided by the present invention is significantly superior to the comparative scheme in terms of static friction coefficient, dynamic friction coefficient, rebound rate, and impact rebound noise. This is attributed to the construction of double emulsion hollow microspheres, surface grafting modification, and multi-scale composite, thereby solving the performance balance problem of anti-slip and noise-reducing materials between high anti-slip properties, high rebound, low compression deformation, and low noise.

Claims

1. A non-slip and sound-absorbing material for shoe soles, comprising a matrix resin and additives, characterized in that: The specific raw materials used in the preparation are based on 100 parts of high-damping thermoplastic polyurethane, and include the following components: 3-15 parts of surface-modified layered bimetallic hydroxide nanosheets, 7-30 parts of surface-grafted silicone rubber hollow microspheres, 4-20 parts of poly(p-phenylene terephthalamide) fiber, 1-2 parts of antioxidant 1010, 1.5-3 parts of calcium stearate, and 2-4 parts of silicone masterbatch.

2. The anti-slip and sound-absorbing material for shoe soles according to claim 1, characterized in that: The surface-modified layered bimetallic hydroxide nanosheets are organically modified Mg-Al or Zn-Al layered hydroxides with a diameter of 20–100 nm and a layer thickness of 1–5 nm.

3. The anti-slip and sound-absorbing material for shoe soles according to claim 1, characterized in that: The surface-grafted silicone rubber hollow microspheres are grafted with a polycaprolactone polymer brush layer through ring-opening polymerization of ε-caprolactone monomer, and the particle size is 40-60µm.

4. The anti-slip and sound-absorbing material for shoe soles according to claim 1, characterized in that: The poly(p-phenylene terephthalamide) fiber has a length of 3–6 mm and a diameter of 10–30 µm.

5. The anti-slip and sound-absorbing material for shoe soles according to claim 1, characterized in that... The anti-slip and sound-absorbing material used for the sole has a static friction coefficient ≥0.8, a dynamic friction coefficient ≥0.7, a rebound rate ≥85%, and an impact rebound noise ≤45dB.

6. A method for preparing the anti-slip and sound-absorbing material for shoe soles according to any one of claims 1-5, characterized in that, Includes the following steps: S1: Double emulsion preparation; S11: Sorbitol anhydride monooleate is dissolved in deionized water to obtain an internal aqueous phase solution; methyl vinyl silicone rubber prepolymer is mixed with a platinum catalyst to obtain an oil phase; S12: The aqueous phase solution prepared in S11 is added to the oil phase prepared in S11, and shear emulsification is performed to obtain the primary emulsion. S13: Dissolve polysorbate 20 and polyvinyl alcohol in deionized water to obtain an external aqueous phase solution; wet the membrane tube with the primary emulsion prepared in S12, and then place it in the emulsification device, with the external aqueous phase placed in the outer chamber; S14: The primary emulsion prepared in S12 is extruded under pressure and separated from the membrane pores under the flushing of the external aqueous phase to obtain a double emulsion; S2: Preparation of hollow microspheres grafted with silicone rubber on the surface; S21: Add platinum catalyst to the double emulsion prepared in S14, stir and solidify, centrifuge and wash, and dry to obtain silicone rubber hollow microspheres; S22: Disperse the silicone rubber hollow microspheres prepared in S21 in ethanol, irradiate with ultraviolet light for 30 min, then add ε-caprolactone and stannous octoate, stir, cool to room temperature, centrifuge, wash, dry, and sieve to obtain surface-grafted silicone rubber hollow microspheres. S3: Pre-dispersion and blending; S31: Disperse layered bimetallic hydroxide nanosheets in a mixed solvent of ethanol and water, add KH-550, stir, dry, and pulverize to obtain surface-modified layered bimetallic hydroxide nanosheets. S32: The dried high-damping thermoplastic polyurethane was stirred and heated to 90°C, and the surface-modified layered bimetallic hydroxide nanosheets prepared in S31 were added. Then, the surface-grafted silicone rubber hollow microspheres prepared in S22 were added and stirred at high speed to obtain the pre-dispersed material. S33: The pre-dispersed material prepared in S32, poly(p-phenylene terephthalamide) fiber, antioxidant 1010, calcium stearate, and silicone masterbatch are mixed and stirred, melt-extruded, cooled and solidified to obtain an anti-slip and sound-absorbing material.

7. A method for preparing an anti-slip and sound-absorbing material for shoe soles according to claim 6, characterized in that: The internal aqueous phase solution described in S11 has a mass concentration of 1-2%; The methyl vinyl silicone rubber prepolymer described in S11 has a mass ratio of 100:0.4 to the platinum catalyst. The shear emulsification described in S12 has the following parameter settings: rotation speed 10000~15000rpm, duration 2~4min; The primary emulsion described in S12 has an internal aqueous phase to oil phase mass ratio of 1:

5. The external aqueous phase solution described in S13 has a concentration of 2-4%, wherein polysorbate 20 is 1.5-2.5% and polyvinyl alcohol is 0.5-1.5%. The pressure extrusion described in S14 has the following parameter settings: pressure 20-80 kPa, temperature 20-25℃; The dual emulsion described in S14 has an external aqueous phase and a primary emulsion mass ratio of 10:

1.

8. A method for preparing an anti-slip and sound-absorbing material for shoe soles according to claim 6, characterized in that: The platinum catalyst described in S21 is added in such an amount that the concentration of platinum catalyst in the aqueous phase is 0.05%. The stirring and curing described in S21 has the following parameters: temperature 65-75℃, rotation speed 150-250rpm, and duration 3-5h. The centrifugal washing described in S21 uses deionized water and is set with the following parameters: speed 3000 rpm, duration 5 min, and number of cycles 5.

9. A method for preparing an anti-slip and sound-absorbing material for shoe soles according to claim 6, characterized in that: The ε-caprolactone described in S22 is 2 to 4 times the mass of the silicone rubber hollow microspheres; The stannous octoate described in S22 has a mass of 0.2 to 0.5% of the mass of ε-caprolactone; The stirring described in S22 has the following parameters: temperature 110-120℃, speed 200-400rpm, and duration 6-10h. The centrifugal washing described in S22 uses tetrahydrofuran washing, with the following parameters: speed 4000 rpm, duration 5 min.

10. A method for preparing an anti-slip and sound-absorbing material for shoe soles according to claim 6, characterized in that: The KH-550 described in S31 has a mass of 1 to 3% of the mass of the layered bimetallic hydroxide nanosheets; The stirring described in S31 has the following parameters: temperature 60-70℃, pH 4-5, rotation speed 200-400rpm, and duration 3-5h. The high-speed stirring described in S32 has the following parameter settings: temperature 70-80℃, speed 800-1200rpm, and duration 10-15min; The melt extrusion described in S33 has the following parameter settings: the temperatures of the feeding zone, melting zone, mixing zone, and homogenization zone are 150-160℃, 170-180℃, 180-190℃, and 175-185℃, respectively; the die head temperature is 170-180℃; and the screw speed is 200-250 rpm.

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