Shoe and boot material with porous structure

Abstract

The invention provides a shoe and boot material with a porous structure, and relates to the technical field of shoe and boot manufacturing, the shoe and boot material comprises micropores and nanopores, 85% of the micropores are communicated through the nanopores, moisture is discharged through the micropores and the nanopores, and meanwhile the rebound resilience of the shoe and boot material is guaranteed. 85% of the micropores are communicated through the nanopores, moisture is discharged through the micropores and the nanopores, and dryness and comfort are kept; meanwhile, external impact force can be effectively absorbed and dispersed through the micropores, so that foot joints and muscles are protected, and it is guaranteed that the shoe and boot material has good rebound resilience and damping performance.

Description

Technical Field

[0001] The invention relates to the technical field of shoe manufacturing, and in particular to a shoe material with a porous structure. Background Art

[0002] In the footwear manufacturing industry, material selection plays a vital role in product performance. Traditional footwear materials, such as natural leather, artificial leather, rubber and polyurethane, have shown significant limitations in practical applications.

[0003] First, regarding breathability, although natural leather and artificial leather have certain breathability, their moisture removal capacity is limited in extremely hot and humid environments, resulting in moisture accumulation in the shoes, causing discomfort to the wearer. Rubber and some polyurethane materials are almost non-breathable, further exacerbating this problem. Secondly, in terms of shock absorption effect, traditional footwear materials lack a special shock absorption mechanism in structural design, which makes the foot joints and muscles prone to fatigue and damage during long-term walking or high-intensity activities. Current shock absorption technology mostly relies on the design of the sole structure, but the effect is limited and it is difficult to fully cope with the shock absorption challenge. Furthermore, traditional materials are not good at antibacterial performance. The hot and humid environment inside the shoes is prone to breeding bacteria and fungi, leading to frequent problems such as odor and foot infections. Although there are antibacterial coated shoes on the market, their effect and durability are limited, and they have not fundamentally solved the problem. In addition, environmental protection and sustainability issues cannot be ignored. Many traditional footwear materials rely on petrochemical-based materials, which have high energy consumption and large waste emissions during the production process, which is contrary to modern environmental protection concepts. In particular, the production of natural leather involves a large amount of water consumption and the use of chemicals, causing significant pollution to the environment. The production of artificial leather and polyurethane materials also faces environmental challenges. Finally, in the pursuit of high strength and wear resistance, existing footwear materials often increase the weight of the material at the expense of wearing comfort and convenience. Although lightweight materials are comfortable to wear, their mechanical strength and wear resistance are often difficult to meet the standards and are easily damaged during use. In view of this, the present invention proposes a footwear material with a porous structure and a method for manufacturing the same, aiming to overcome the limitations of the prior art and improve the overall performance of footwear. Summary of the invention

[0004] In order to solve the problems of traditional shoe materials in terms of air permeability, shock absorption effect, antibacterial performance, environmental protection, and mechanical strength and weight balance, the present invention provides a shoe material with a porous structure.

[0005] The present invention is achieved in the following manner: A porous shoe material includes micropores and nanopores, 85 percent of the micropores are connected by nanopores, moisture is discharged through the micropores and nanopores, and the resilience of the shoe material is ensured at the same time.

[0006] Furthermore, the pore size of the micropore is 10-200 micrometers, and the pore size of the nanopore is 50-500 nanometers.

[0007] Furthermore, the shoe material in which the micropores are connected by nanopores is prepared by the following materials and processes: The material comprises 30-50 parts of thermoplastic polymer, 20-40 parts of bio-based polymer, 5-10 parts of functional powder, 5-15 parts of foaming agent, 1-10 parts of cross-linking agent, 10-20 parts of additive, 5-15 parts of nano material, 5-15 parts of natural fiber material, and 1-5 parts of antibacterial agent; The specific steps of the process are as follows: a) mixing thermoplastic polymer, bio-based polymer, functional powder, foaming agent, cross-linking agent, additive, nanomaterial, natural fiber material and antimicrobial agent in proportion; b) kneading the mixture under vacuum; c) granulating the kneaded material; d) The granulated material is heated to 180-220°C in the mold and a pressure of 2-10MPa is applied. e) De-mould after cooling to room temperature.

[0008] Further, the thermoplastic polymer includes one or more combinations of polyurethane (PU), ethylene vinyl acetate (EVA), and thermoplastic polyurethane (TPU); The bio-based polymer is selected from one or more combinations of polylactic acid (PLA) or polybutylene succinate (PBS); The functional powder is selected from far infrared functional powder or negative ion powder; The foaming agent is sodium bicarbonate; The cross-linking agent is a peroxide cross-linking agent, specifically dicumyl peroxide; The additives include plasticizers, stabilizers, lubricants and antioxidants; The plasticizer includes one or more combinations of dioctyl phthalate, diisononyl phthalate or trioctyl trimellitate; the stabilizer includes one or more combinations of lead stabilizer, calcium zinc stabilizer or organic tin stabilizer; the lubricant includes one or more combinations of stearic acid, calcium stearate or zinc stearate; the antioxidant includes one or more combinations of hindered phenol antioxidants, phosphate antioxidants or thioether antioxidants; The nano material is selected from nano silicon dioxide or nano calcium carbonate; The natural fiber material is selected from bamboo fiber, coconut shell fiber or corn fiber; The antibacterial agent is selected from silver ions or nano silver.

[0009] Further, the heating and pressurizing step includes two stages, the temperature of the first stage is 160-180°C, and the temperature of the second stage is 180-220°C; The cooling step includes water cooling or air cooling for 5-15 minutes, and microwave treatment is performed during the cooling process. 85 percent of the micropores are connected by nanopores, which discharge moisture to keep you dry and comfortable. At the same time, the micropores can effectively absorb and disperse external impact forces, thereby protecting the joints and muscles of the feet and ensuring that the shoe material has good resilience and shock absorption properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The present invention is a flow chart of a method for manufacturing a footwear material having a porous structure. DETAILED DESCRIPTION

[0011] The present invention will be further described below in conjunction with specific examples, and the advantages and features of the present invention will become clearer as the description proceeds. However, the specific experimental methods involved in the following examples are all conventional methods or implemented under the conditions recommended by the manufacturer's instructions unless otherwise specified.

[0012] A porous shoe material includes micropores and nanopores, 85 percent of the micropores are connected by nanopores, moisture is discharged through the micropores and nanopores, and the resilience of the shoe material is ensured at the same time.

[0013] The pore size of the micropore is 10-200 micrometers, and the pore size of the nanopore is 50-500 nanometers.

[0014] The footwear material with a porous structure in which micropores are connected by nanopores is prepared by the following materials and processes: The material comprises 30-50 parts of thermoplastic polymer, 20-40 parts of bio-based polymer, 5-10 parts of functional powder, 5-15 parts of foaming agent, 1-10 parts of cross-linking agent, 10-20 parts of additive, 5-15 parts of nano material, 5-15 parts of natural fiber material, and 1-5 parts of antibacterial agent; The thermoplastic polymer includes one or more combinations of polyurethane (PU), ethylene vinyl acetate (EVA), and thermoplastic polyurethane (TPU); The bio-based polymer is selected from one or more combinations of polylactic acid (PLA) or polybutylene succinate (PBS); The functional powder is selected from far-infrared functional powder or negative ion powder; far-infrared functional powder, such as far-infrared ceramic powder, can absorb energy from the human body and the environment and release far-infrared rays. Far-infrared rays can promote blood circulation and enhance cell metabolism through their thermal effect, and this effect has an enhancing effect on the breathability and health functions of shoes and boots. Negative ion powder, such as tourmaline powder, negative ion materials such as tourmaline can release negative ions through friction, pressure or temperature changes. Negative ions have the effects of inhibiting bacteria, deodorizing, and improving air quality, which help to improve the antibacterial and deodorizing properties of footwear materials. Therefore, the functions of these powders are based on their physical and chemical properties, which can effectively improve the health performance and comfort of footwear materials. For example, far-infrared ceramic powder can improve breathability by releasing far-infrared rays, while negative ion powder improves antibacterial properties by releasing negative ions.

[0015] The foaming agent is sodium bicarbonate; sodium bicarbonate is a fine-pore foaming agent with a higher nucleation density, so it can produce more and smaller bubbles during the foaming process. By increasing the nucleation density, the fine-pore foaming agent can promote the formation of a fine pore structure inside the material and reduce the size of the pores. However, to achieve nanoscale pores, simply replacing the foaming agent is far from enough. Ordinary fine-pore foaming agents can usually control the pore size in the micrometer range, but further optimization is needed to enter the nanoscale. Nanoscale pores are usually in the range of 1-100 nanometers, The crosslinking agent is a peroxide crosslinking agent, specifically dicumyl peroxide; the type and amount of the crosslinking agent determine the structure of the material network, and a higher crosslinking density will limit the expansion of the pores, making the pores smaller and more stable.

[0016] The additives include plasticizers, stabilizers, lubricants and antioxidants; the plasticizer includes one or more combinations of dioctyl phthalate, diisononyl phthalate or trioctyl trimellitate; the stabilizer includes one or more combinations of lead stabilizers, calcium zinc stabilizers or organic tin stabilizers; the lubricant includes one or more combinations of stearic acid, calcium stearate or zinc stearate; the antioxidant includes one or more combinations of hindered phenol antioxidants, phosphate antioxidants or thioether antioxidants; The nanomaterial is selected from nano silicon dioxide or nano calcium carbonate; the nanomaterial can act as a nucleating agent during the foaming process to promote the formation of more pores, thereby reducing the pore size. The natural fiber material is selected from bamboo fiber, coconut shell fiber or corn fiber; the use of bio-based polymers and natural fiber materials, combined with the design of a porous structure, makes the shoe material more environmentally friendly and has good biodegradability.

[0017] The antibacterial agent is selected from silver ions or nano silver. The antibacterial agent is added and the distribution uniformity of the antibacterial agent is enhanced through the nanopore structure, thereby significantly improving the antibacterial performance of the material.

[0018] The specific steps of the process are as follows: a) mixing the base material, foaming agent, cross-linking agent, additive, nanomaterial, natural fiber material and antibacterial agent according to proportion; b) kneading the mixture under vacuum; c) granulating the kneaded material; d) The granulated material is heated to 180-220°C in the mold and a pressure of 2-10MPa is applied. e) De-mould after cooling to room temperature.

[0019] The substrate includes a thermoplastic polymer, a bio-based polymer, and a functional powder; In order to ensure the controllability of the gradual and stable molding and foaming process of the material, the heating and pressurizing step includes two stages, the temperature of the first stage is 160-180°C, and the temperature of the second stage is 180-220°C; The cooling step comprises water cooling or air cooling for 5-15 minutes, and microwave treatment is performed during the cooling process.

[0020] The foaming process of the present invention belongs to one-time foaming and is a compression foaming process. Pressure is applied through the compression process to effectively restrict the expansion of bubbles. The foaming agent is continuously decomposed in the mold through a two-stage heating process to form a microporous and nanoporous structure. During the first stage, the heating temperature is 160-180°C and the pressure is 2-10MPa. At the lower temperature of the first stage, the crosslinking agent begins to decompose, but the speed is relatively slow. The temperature at this stage enhances the fluidity of the material, but has not yet reached the level of complete crosslinking and hardening. Therefore, the material can flow, fill and form properly in the mold, and a preliminary crosslinking reaction occurs at the same time to form a basic material network structure. The heating at this stage ensures that the material components are evenly distributed and prevents premature foaming from causing unstable or irregular pore structures. In the second stage, the temperature is raised to 180-200°C, reaching the complete decomposition temperature of the foaming agent, and generating a large amount of gas. At this time, the crosslinking reaction reaches a higher degree, the material hardens, and a stable porous structure is formed. In this stage, the gas released by the decomposition of the foaming agent diffuses in the already formed material network, producing a honeycomb microporous structure and providing a basis for the interconnected pores in the subsequent nanopore formation process. The heating at this stage ensures the uniformity of the pore size, so that the micropore and nanopore structures have a consistent distribution, optimizing the permeability of the material and the uniform distribution of the antimicrobial agent. Through staged heating, the initial molding and cross-linking at a lower temperature in the first stage can control the decomposition rate of the foaming agent, avoiding the release of a large amount of gas at one time, resulting in excessive or uneven pore size. The high-temperature heating in the second stage ensures that the foaming agent is completely decomposed and releases gas, and the final micropores of 10-200 microns and nanopores of 50-500 nanometers are formed. This gradual heating and pressure change can adjust the pore density, strength and air permeability of the material, and ensure the stability and functionality of the porous structure. The two-stage heating and pressurization process can ensure the uniform and stable formation of the honeycomb microporous structure and the interconnected nanoporous structure, and connect the honeycomb microporous structure through the nanoporous structure, balancing the mechanical strength and air permeability of the material. The initial low-temperature stage helps the material maintain its mechanical strength, while the later high-temperature stage ensures the formation of a stable porous structure, enhancing breathability, shock absorption and antibacterial effects.

[0021] Therefore, heating and pressurizing are divided into two stages in order to achieve optimal control during material molding, foaming, cross-linking and pore structure formation, ensuring that the porous structure footwear material has excellent mechanical properties, breathability and antibacterial properties.

[0022] Embodiment 1: Material formula: 40 parts of polyurethane (PU); 30 parts of polylactic acid (PLA); 7 parts of far-infrared functional powder; 10 parts of sodium bicarbonate (NaHCO3); 5 parts of dicumyl peroxide (DCP); 8 parts of plasticizer (dioctyl phthalate); 10 parts of nano-silicon dioxide; 7 parts of bamboo fiber; 3 parts of silver ions; Manufacturing steps: a) Mixing the base material, foaming agent, cross-linking agent, additive, nano material, natural fiber material and antibacterial agent according to the formula ratio.

[0023] b) kneading the mixture under vacuum.

[0024] c) granulating the kneaded material.

[0025] d) The granulated material is heated to 200°C in the mold and a pressure of 5 MPa is applied for 10 minutes. The temperature of the first stage is 170°C and the temperature of the second stage is 200°C; e) demoulding after cooling to room temperature, wherein the cooling step comprises water cooling or air cooling for 5-15 minutes, and performing microwave treatment during the cooling process.

[0026] This embodiment uses a combination of polyurethane and polylactic acid, combined with far-infrared functional powder and bamboo fiber, to improve the air permeability and shock absorption effect of the material. The addition of nano-silicon dioxide and silver ions enhances the antibacterial property and mechanical strength, and the overall material is lightweight and environmentally friendly.

[0027] Embodiment 2: Material formula: 35 parts of ethylene vinyl acetate (EVA); 25 parts of polybutylene succinate (PBS); 6 parts of negative ion powder; 12 parts of sodium bicarbonate (NaHCO3); 6 parts of dicumyl peroxide (DCP); 15 parts of calcium zinc stabilizer; 12 parts of nano calcium carbonate; 10 parts of coconut shell fiber; 4 parts of nano silver.

[0028] Manufacturing steps: a) Mixing the base material, foaming agent, cross-linking agent, additive, nano material, natural fiber material and antibacterial agent according to the formula ratio.

[0029] b) kneading the mixture under vacuum.

[0030] c) granulating the kneaded material.

[0031] d) The granulated material is heated to 220°C in the mold and a pressure of 8 MPa is applied for 15 minutes. The temperature of the first stage is 180°C and the temperature of the second stage is 220°C; e) demoulding after cooling to room temperature, the cooling step includes 5-15 minutes of water cooling or air cooling, and microwave treatment during the cooling process.

[0032] In this embodiment, the combination of EVA and PBS, the addition of negative ion powder and coconut shell fiber make the material excellent in air permeability and shock absorption performance. The addition of nano calcium carbonate and nano silver improves the antibacterial property and mechanical strength of the material. This formula is particularly suitable for occasions with high antibacterial requirements.

[0033] Embodiment 3: Material formula: 50 parts of thermoplastic polyurethane (TPU); 30 parts of polylactic acid (PLA); 9 parts of far-infrared functional powder; 10 parts of sodium bicarbonate (NaHCO3); 4 parts of diisopropyl peroxide (DCP); 10 parts of hindered phenol antioxidant; 8 parts of nano-silicon dioxide; 8 parts of bamboo fiber; 2 parts of silver ions Manufacturing steps: a) Mixing the base material, foaming agent, cross-linking agent, additive, nano material, natural fiber material and antibacterial agent according to the formula ratio.

[0034] b) kneading the mixture under vacuum.

[0035] c) granulating the kneaded material.

[0036] d) Heat the granulated material in the mold to 190°C and apply a pressure of 6MPa for 12 minutes. (The temperature in the first stage is 165°C, and the temperature in the second stage is 190°C; e) demoulding after cooling to room temperature, the cooling step includes 5-15 minutes of water cooling or air cooling, and microwave treatment during the cooling process.

[0037] This embodiment uses a combination of TPU and PLA to increase the flexibility and environmental friendliness of the material. The addition of far-infrared functional powder and bamboo fiber improves the comfort and antibacterial properties of the material, and nano-silicon dioxide further enhances the mechanical strength. It is suitable for footwear applications that require high strength and high comfort.

[0038] Embodiment 4: Material formula: 45 parts of polyurethane (PU); 35 parts of polybutylene succinate (PBS); 6 parts of negative ion powder; 13 parts of sodium bicarbonate (NaHCO3); 7 parts of dicumyl peroxide (DCP); 12 parts of calcium stearate; 11 parts of nano calcium carbonate; 5 parts of coconut shell fiber; 3 parts of nano silver.

[0039] Manufacturing steps: a) Mixing the base material, foaming agent, cross-linking agent, additive, nano material, natural fiber material and antibacterial agent according to the formula ratio.

[0040] b) kneading the mixture under vacuum.

[0041] c) granulating the kneaded material.

[0042] d) The granulated material was heated to 210° C. in a mold and a pressure of 7 MPa was applied and maintained for 14 minutes.

[0043] The temperature of the first stage is 170°C, and the temperature of the second stage is 210°C; e) demoulding after cooling to room temperature, the cooling step includes 5-15 minutes of water cooling or air cooling, and microwave treatment during the cooling process.

[0044] This embodiment uses a combination of PU and PBS to provide excellent elasticity and environmental protection. The use of negative ion powder and coconut shell fiber improves the health function and air permeability of the material, and calcium stearate and nano calcium carbonate enhance the stability and wear resistance of the material.

[0045] Embodiment 5: Material formula: 30 parts of ethylene vinyl acetate (EVA); 40 parts of polylactic acid (PLA); 5 parts of far-infrared functional powder; 15 parts of sodium bicarbonate (NaHCO3); 8 parts of dicumyl peroxide (DCP); 10 parts of phosphate antioxidant; 10 parts of nano-silicon dioxide; 7 parts of bamboo fiber; 2 parts of silver ions Manufacturing steps: a) Mixing the base material, foaming agent, cross-linking agent, additive, nano material, natural fiber material and antibacterial agent according to the formula ratio.

[0046] b) kneading the mixture under vacuum.

[0047] c) granulating the kneaded material.

[0048] d) The granulated material was heated to 180° C. in a mold and a pressure of 9 MPa was applied and maintained for 10 minutes.

[0049] The temperature of the first stage is 160°C, and the temperature of the second stage is 180°C; e) demoulding after cooling to room temperature, the cooling step includes 5-15 minutes of water cooling or air cooling, and microwave treatment during the cooling process.

[0050] This embodiment provides good flexibility and environmental protection through the combination of EVA and PLA. The addition of far-infrared functional powder and bamboo fiber improves the comfort and antibacterial properties of the material, and nano-silicon dioxide and silver ions enhance the mechanical strength and hygienic properties of the material.

[0051] The footwear materials prepared in the above embodiments were tested in terms of air permeability, shock absorption, antibacterial performance, biodegradability, mechanical strength and weight, and compared with traditional polyurethane footwear material A and traditional rubber footwear material B. The experimental process and experimental data are as follows: Experiment 1: Comparison of air permeability performance Procedure: Use an air permeability tester and follow standard test methods to test the air permeability of the material sample in L / m² / s.

[0052] Comparative experimental materials: Material A: traditional polyurethane shoe material; Material B: traditional rubber shoe material Result analysis: The air permeability of the material of the embodiment is significantly higher than that of the prior art material. The porous structure design allows air to pass through the material more freely, thereby improving the air permeability and solving the problem of poor air permeability in traditional shoe materials.

[0053] Experiment 2: Comparison of shock absorption effects Procedure: Use an impact testing machine and perform the test according to standard methods. Test the shock absorption performance of the material sample and measure its shock absorption rate in parts.

[0054] Comparative experimental materials: Material A: traditional polyurethane shoe material; Material B: traditional rubber shoe material Result analysis: The shock absorption performance of the embodiment material is significantly better than that of the prior art material. The microporous structure effectively absorbs and disperses external impact force, provides better shock absorption effect, and is particularly suitable for sports shoes and work boots.

[0055] Experiment 3: Comparison of antibacterial properties Process: Use an antibacterial tester and follow standard methods to test the antibacterial properties of material samples and measure their antibacterial rate in units of parts.

[0056] Comparative experimental materials: Material A: traditional polyurethane shoe material; Material B: traditional rubber shoe material Result analysis: The antibacterial performance of the example material is significantly better than that of the prior art material. The nanoporous structure enhances the uniformity of the distribution of the antibacterial agent, significantly improves the antibacterial performance of the material, and ensures the health of the wearer's feet.

[0057] Experiment 4: Environmental protection and sustainability comparison Procedure: Use a biodegradation tester and follow standard methods to test the biodegradability of material samples and measure their degradation rate in parts.

[0058] Comparative experimental materials: Material A: traditional polyurethane shoe material; Material B: traditional rubber shoe material Result analysis: The biodegradability of the material in the embodiment is significantly better than that of the prior art material. The use of bio-based polymers and natural fiber materials makes the material more environmentally friendly and meets modern environmental protection requirements.

[0059] Experiment 5: Mechanical Strength and Weight Comparison Process: Use a tensile testing machine and follow standard methods to test the tensile strength and density of the material sample in MPa and g / cm 3 .

[0060] Comparative experimental materials: Material A: traditional polyurethane shoe material; Material B: traditional rubber shoe material Result analysis: The example material shows high mechanical strength and wear resistance while maintaining its lightweight characteristics. The porous structure design and the introduction of nanomaterials effectively improve the overall stability and durability of the material, which is superior to the existing technical materials.

[0061] in conclusion: By comparing the experimental data, it can be seen that the porous structure footwear material of the present invention is significantly superior to the existing technology materials in terms of air permeability, shock absorption effect, antibacterial performance, environmental protection and sustainability, as well as mechanical strength and weight balance. The differences between the embodiments are mainly reflected in the differences in material formula and specific parameters. These differences lead to slight changes in performance, but overall they are superior to the existing technology materials, significantly improving the comprehensive performance of footwear materials and solving the problems in the existing technology.

[0062] The present invention forms a stable microporous and nanoporous structure through staged temperature control, molding process and material formula design; combines far-infrared powder, nanomaterials and natural fibers to achieve coordinated optimization of porous structure and functional performance.

[0063] 1) Technical mechanism of temperature stage control The present invention adopts two-stage heating control (160-180°C and 180-200°C). The mechanism of this technical design mainly involves the dynamic balance between the decomposition rate of the foaming agent, the cross-linking reaction rate and the material fluidity: The first stage (160~180℃): material molding and preliminary cross-linking In this temperature range, the cross-linking agent begins to decompose, and the molecular chains in the system undergo a preliminary cross-linking reaction, but the reaction rate is slow. The fluidity of the material is enhanced, which can fully fill the mold cavity, ensure the uniform distribution of the material, and avoid irregular pore size or structural defects in the early stage of bubble formation. The decomposition rate of the foaming agent (such as sodium bicarbonate) is low, and the gas produced is limited. At this time, smaller initial bubbles are formed, which play a supporting and shaping role. The uniform distribution of the material in the mold is guaranteed to avoid incomplete structure due to insufficient fluidity. The initially formed cross-linked network provides support for the subsequent foaming process to avoid excessive pore size or collapse caused by excessive bubble expansion.

[0064] The second stage (180~200℃): decomposition of foaming agent and formation of stable pore structure In this temperature range, the foaming agent decomposes rapidly, a large amount of gas is released, and larger bubbles are formed and gradually expand. At the same time, the cross-linking reaction is accelerated, and the material gradually changes from a viscoelastic state to a solid state, completing the curing and hardening process. At this time, the cross-linked network structure plays a restraining role, so that the bubble expansion is controlled, the bubble size is more uniform and the distribution is stable.

[0065] The formation of micropores and nanopores is based on two mechanisms: Honeycomb micropore structure: supported by the expansion of larger bubbles, with pore sizes between 10 and 200 μm, providing shock absorption and lightweight properties. Interconnected nanopore structure: The diffusion of foaming gas inside the material forms interconnected small pores with pore sizes between 50 and 500 nm, enhancing air permeability and uniform distribution of antimicrobial agents.

[0066] By accelerating the decomposition and cross-linking reaction of the foaming agent at high temperature, the uniformity and stability of the pore structure are achieved. The coordinated existence of honeycomb micropores and interconnected nanopores is achieved, optimizing the material's air permeability, shock absorption and antibacterial effects.

[0067] 2) Synergistic effect of temperature and pressure This application applies a pressure of 2~10MPa during the heating process, and its mechanism is mainly reflected in the following aspects: Inhibit excessive expansion of bubbles: Pressure controls the expansion rate of bubbles, ensuring that the pore size is within a controllable range and avoiding excessive or collapsed pore structures. Improve the uniformity of pore structure: Under the action of heating and pressure, the gas inside the bubbles diffuses evenly, which helps to form a consistent honeycomb and interconnected pore structure. Enhance the mechanical properties of the material: Pressure promotes the tight cross-linking of molecular chains, enhances the hardness and strength of the material, and balances the requirements of lightness and strength. Pressure and temperature control ensure that the bubble formation rate matches the curing rate of the material to form a stable and uniform porous structure. The material has high mechanical strength and light weight to meet the needs of high-strength application scenarios.

[0068] 3. Co-design of material formulation and pore structure The material formula of the present invention optimizes the pore structure and material performance through the synergistic effect of functional powder, foaming agent, nanomaterial and natural fiber material; functional powder, such as far-infrared functional powder and negative ion powder, far-infrared powder releases infrared rays to enhance the air permeability and health of the material. Negative ion powder releases negative ions to inhibit bacteria and deodorize, thereby improving the hygienic properties of footwear materials. Foaming agents, such as sodium bicarbonate, gradually decompose at two stage temperatures, and bubbles are formed evenly to avoid sudden decomposition leading to uncontrolled pore size. Nanomaterials, such as nano-silicon dioxide and nano-calcium carbonate, provide skeleton support to enhance the mechanical strength and stability of the material. Natural fiber materials, such as bamboo fiber and coconut shell fiber, provide lightweight and environmentally friendly characteristics, and enhance the biodegradability and environmental protection of the material. The material formula is combined with temperature and pressure processes to form a multifunctional porous structure, which achieves a comprehensive improvement in air permeability, shock absorption, antibacterial and environmental protection performance, and meets the high air permeability, shock absorption and environmental protection requirements of footwear materials.

[0069] 1. The porous structure design of the present invention makes the shoe material have extremely high air permeability. The combination of nanopores and micropores can effectively discharge moisture in the shoes, keeping the feet dry and comfortable, and is particularly suitable for long-term wear and high-intensity activities. Compared with the airtight shoe materials in the prior art, the present invention solves the problem of poor air permeability leading to hot and sweaty feet, and significantly improves the comfort of wearing.

[0070] 2. The microporous structure in the material of the present invention provides excellent shock absorption effect. The micropores can effectively absorb and disperse external impact force, thereby protecting the foot joints and muscles. Compared with the shoe materials with insufficient shock absorption performance in the prior art, the present invention solves the fatigue and discomfort caused by uneven force on the foot, and is particularly suitable for sports shoes and work boots, providing better comfort and safety.

[0071] 3. Antibacterial agents are added to the material of the present invention, and the uniformity of the distribution of the antibacterial agents is enhanced through the nanopore structure, thereby significantly improving the antibacterial properties of the material. Nanopores can limit the growth environment of bacteria and fungi, thereby preventing odor in shoes and foot infections. Compared with the shoe materials in the prior art that are susceptible to bacterial growth, the present invention significantly improves the hygienic properties of shoes and boots, ensuring the health of the wearer's feet.

[0072] 4. The materials of the present invention use bio-based polymers and natural fiber materials, and the porous structure design makes the shoe materials more environmentally friendly and has good biodegradability. Compared with the existing shoe materials mainly based on petrochemical materials, the present invention provides a more environmentally friendly and sustainable solution, responding to the current society's demand for green environmental protection.

[0073] 5. By introducing nanomaterials and natural fiber materials into the material and combining with porous structure design, the shoe material of the present invention has high mechanical strength and wear resistance while maintaining the lightweight characteristics of the material. The combination of honeycomb and interconnected pore structures enhances the overall stability and durability of the material. Compared with the shoe materials in the prior art that are not strong enough or too heavy, the present invention not only increases the service life of the material, but also improves the convenience and comfort of wearing.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several changes and improvements can be made without departing from the overall concept of the present invention, which should also be regarded as the scope of protection of the present invention.

Claims

1. A porous shoe material, comprising micropores and nanopores, characterized in that: 85 percent of the micropores are connected by nanopores, which discharge moisture while ensuring the resilience of the shoe material.

2. The porous structure shoe material according to claim 1, characterized in that: The pore size of the micropore is 10-200 micrometers, and the pore size of the nanopore is 50-500 nanometers.

3. The porous structure shoe material according to claim 2, characterized in that: The shoe material in which micropores are connected by nanopores is prepared by the following materials and processes: The material comprises 30-50 parts of thermoplastic polymer, 20-40 parts of bio-based polymer, 5-10 parts of functional powder, 5-15 parts of foaming agent, 1-10 parts of cross-linking agent, 10-20 parts of additive, 5-15 parts of nano material, 5-15 parts of natural fiber material, and 1-5 parts of antibacterial agent; The specific steps of the process are as follows: a) mixing thermoplastic polymer, bio-based polymer, functional powder, foaming agent, cross-linking agent, additive, nanomaterial, natural fiber material and antimicrobial agent in proportion; b) kneading the mixture under vacuum; c) granulating the kneaded material; d) The granulated material is heated to 180-220°C in the mold and a pressure of 2-10MPa is applied. e) De-mould after cooling to room temperature.

4. The porous structure shoe material according to claim 3, characterized in that: The thermoplastic polymer includes one or more combinations of polyurethane (PU), ethylene vinyl acetate (EVA), and thermoplastic polyurethane (TPU); The bio-based polymer is selected from one or more combinations of polylactic acid (PLA) or polybutylene succinate (PBS); The functional powder is selected from far infrared functional powder or negative ion powder; The foaming agent is sodium bicarbonate; The cross-linking agent is a peroxide cross-linking agent, specifically dicumyl peroxide; The additives include plasticizers, stabilizers, lubricants and antioxidants; The plasticizer includes one or more combinations of dioctyl phthalate, diisononyl phthalate or trioctyl trimellitate; the stabilizer includes one or more combinations of lead stabilizer, calcium zinc stabilizer or organic tin stabilizer; the lubricant includes one or more combinations of stearic acid, calcium stearate or zinc stearate; the antioxidant includes one or more combinations of hindered phenol antioxidants, phosphate antioxidants or thioether antioxidants; The nano material is selected from nano silicon dioxide or nano calcium carbonate; The natural fiber material is selected from bamboo fiber, coconut shell fiber or corn fiber; The antibacterial agent is selected from silver ions or nano silver.

5. The porous structure shoe material according to claim 3, characterized in that: The heating and pressurizing step includes two stages, the temperature of the first stage is 160-180°C, and the temperature of the second stage is 180-220°C; The cooling step comprises water cooling or air cooling for 5-15 minutes, and microwave treatment is performed during the cooling process.

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