Macromolecular mildew-proof antibacterial micro-foaming breathable shoe material and preparation method thereof

Abstract

The invention relates to the field of insoles, and particularly discloses a macromolecular mildew-proof antibacterial micro-foaming breathable shoe material and a preparation method thereof.The shoe material comprises a foaming macromolecular matrix, and the foaming macromolecular matrix is mixed with an antibacterial plant extract, a mildew inhibitor, a functional additive and a volatile aromatic component; the antibacterial plant extract comprises at least one of mugwort plant extract and wula sedge extract, the mildew preventive is cinnamyl aldehyde, the functional additive comprises at least one of nano TiO2, chitosan, tea polyphenol, zinc oxide or graphene oxide, and the volatile aromatic component is volatile natural essential oil or perfume component. And the foaming polymer matrix is a bio-based polymer material. According to the invention, sustainable bio-based manufacturing and multifunctional integration can be taken into consideration, and efficient, simple, convenient and high-quality micro-foaming breathable shoe material preparation is realized.

Description

[0001] Technical Field

[0002] The present invention relates to the field of shoe materials, and particularly to a polymer anti-mildew and antibacterial micro-foamed breathable shoe material and a preparation method thereof. Background Art

[0003] With the continuous improvement of people's requirements for healthy, comfortable and green environmental protection shoe materials, functional materials such as insoles and soles are changing from traditional petrochemical polymer systems to sustainable bio-based material systems. Existing polymer breathable shoe materials mainly rely on polyurethane (PU) or ethylene-vinyl acetate copolymer, and obtain pore structures through physical or chemical foaming to improve air circulation and cushioning performance; however, such materials still have the following limitations: on the one hand, the raw materials rely on petrochemical resources, which not only increases the environmental burden, but also makes the recycling and degradation of products difficult; on the other hand, commonly used synthetic antibacterial and anti-mildew agents are volatile, precipitate, or are difficult to stably exert their efficacy for a long time due to poor compatibility with the highly polar PU matrix, resulting in a short service life of the shoe material, serious odor problems, and lack of natural green activity. Summary of the Invention

[0004] In view of the above technical problems, the present invention provides a polymer anti-mildew and antibacterial micro-foamed breathable shoe material and a preparation method thereof.

[0005] Other features and advantages of the present disclosure will become apparent from the following detailed description, or be learned in part through the practice of the present disclosure.

[0006] According to one aspect of the present invention, a polymer anti-mildew and antibacterial micro-foamed breathable shoe material is proposed. The shoe material includes a foamed polymer matrix, in which an antibacterial plant extract, an anti-mildew agent, a functional additive, and a volatile aromatic component are admixed; the antibacterial plant extract includes at least one selected from Artemisia plant extract and Carex meyeriana Kunth extract, the anti-mildew agent is cinnamaldehyde, the functional additive includes at least one selected from nano-TiO2, chitosan, tea polyphenols, zinc oxide or graphene oxide, the volatile aromatic component is a volatile natural essential oil or a spice component, and the foamed polymer matrix is a bio-based polymer material.

[0007] Furthermore, the mass ratio of the antibacterial plant extract to cinnamaldehyde is (7-8):(2-3).

[0008] Furthermore, the nano-TiO2, the chitosan, the tea polyphenols, the zinc oxide and the graphene oxide are dispersed in the foamed polymer matrix. The content of nano-TiO2 is 0.5-5 wt%, the content of chitosan is 0.1-3 wt%, the content of tea polyphenols is 0.1-3 wt%, the content of zinc oxide is 0.5-5 wt%, and the content of graphene oxide is 0.01-1 wt%.

[0009] Further, the foamed polymer matrix has a cell structure with an average cell diameter of 0.1 - 1.0 μm and a cell density of about 10 6 - 10 8 cells / cm 2 .

[0010] According to another aspect of the present invention, a method for preparing a polymer anti - mildew and antibacterial micro - foamed breathable shoe material is disclosed. The method is used to prepare the polymer anti - mildew and antibacterial micro - foamed breathable shoe material as described above, and the method includes steps S11 - S17:

[0011] S11: Under the protection of inert gas, a polyester polyol with a molecular weight of 2000 and a diisocyanate mixture are added to a reaction kettle. The diisocyanate mixture is obtained by mixing a bio - based polymeric diisocyanate and hexamethylene diisocyanate in a mass ratio of 25:75, 50:50, or 75:25;

[0012] S12: The reaction kettle is heated to 80 °C and stirring is maintained until a polyurethane prepolymer with a free isocyanate group content of 8.0 ± 0.1% is obtained;

[0013] S13: The polyurethane prepolymer and a chain extender are mixed in the reaction kettle. The chain extender is 1,4 - butanediol, and 0.2 wt% of dibutyltin dilaurate catalyst is added, and a chain - extending reaction is carried out under stirring conditions;

[0014] S14: The antibacterial plant extract, the mildew - proof agent, the functional additive, and the volatile aromatic component are successively added to the reaction kettle, and stirring is continued at 80 °C to obtain an overall mixture;

[0015] S15: A foaming agent is added to the homogenized overall mixture, and the overall mixture is continuously stirred until bubbles are generated in the overall mixture;

[0016] S16: The overall mixture is introduced into a mold pre - heated to 50 °C, and pressure is applied to the mold so that the material in the mold is hot - pressed into a product blank shape;

[0017] S17: The pre - formed part after mold pressing is removed from the mold, and the product blank shape is further cured at 50 °C to complete the curing of the foaming system.

[0018] Further, the molar ratio of the free isocyanate group in the polyurethane prepolymer to the hydroxyl group of the chain extender is 0.95:1 - 1.10:1.

[0019] Further, when determining the content of the free isocyanate group, titration is used for determination.

[0020] Further, the foaming agent is one of azodicarbonamide and supercritical CO2;

[0021] In step S15, the overall mixture containing the foaming agent is subjected to high-shear mixing at 1000 - 3000 rpm for 30 seconds to 2 minutes, so that the foaming agent forms uniformly dispersed micro-nuclei in the overall mixture and generates bubbles.

[0022] Further, in step S16, when the overall mixture is injected into the mold, the pressure in the mold is maintained at 1 - 5 MPa for 10 - 60 seconds, and then quickly depressurized to 0.1 - 0.3 MPa to induce nucleation growth, forming a micro-foamed structure with an average pore diameter of 0.1 - 1.0 μm and a pore density of about 10 6 ~10 8 per cm 2 ³.

[0023] Further, after the product blank is cured, the product blank is subjected to laser drilling, plasma treatment and cutting to form an insole.

[0024] Adopting the above scheme, the beneficial effects of the present invention are as follows:

[0025] By mixing bio-based diisocyanate with hexamethylene diisocyanate and using bio-based 1,4-butanediol for chain extension, the renewable carbon content therein is significantly increased, which helps to reduce the dependence on petrochemical resources, promote the green synthesis process, and the production process can be operated in the same reaction kettle, with the process simplified and convenient, improving production efficiency; by changing the mixing ratio of the diisocyanate mixture, the tensile strength and elasticity of the final product can be adjusted to adapt to complex environmental uses;

[0026] The synergistic effect of Artemisia or Achnatherum splendens plant extract and cinnamaldehyde in a mass ratio of (7 - 8):(2 - 3) not only endows the material with a broad-spectrum antibacterial function but also has a mildew-inhibiting effect; functional aids such as nano-TiO2, chitosan, tea polyphenols, zinc oxide, and graphene oxide are evenly dispersed, which can simultaneously improve the mechanical strength, wear resistance, antioxidant, and self-cleaning properties of the material. Description of the Drawings

[0027] Figure 1 is a flow chart of the preparation method of the high-molecular mildew-proof and antibacterial micro-foamed breathable shoe material of the present invention. Detailed Embodiments

[0028] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present disclosure. However, those skilled in the art will recognize that the technical solutions of the present disclosure may be practiced without one or more of the specific details, or may be implemented using other methods, components, devices, steps, etc. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring the various aspects of the present disclosure.

[0029] In one embodiment, a polymer anti-mildew and antibacterial micro-foamed breathable shoe material is provided. The shoe material includes a foamed polymer matrix, and an antibacterial plant extract, a mildew-proof agent, a functional additive, and a volatile aromatic component are admixed in the foamed polymer matrix; the antibacterial plant extract includes at least one selected from Artemisia plant extract and Carex meyeriana Kunth extract, the mildew-proof agent is cinnamaldehyde, the functional additive includes at least one selected from nano-TiO₂, chitosan, tea polyphenols, zinc oxide, or graphene oxide, the volatile aromatic component is a volatile natural essential oil or a spice component, and the foamed polymer matrix is a bio-based polymer material.

[0030] As a supplement, the mass ratio of the antibacterial plant extract to cinnamaldehyde is (7 - 8):(2 - 3).

[0031] In addition, the nano-TiO₂, the chitosan, the tea polyphenols, the zinc oxide, and the graphene oxide are dispersed in the foamed polymer matrix. The content of nano-TiO₂ is 0.5 - 5 wt%, the content of chitosan is 0.1 - 3 wt%, the content of tea polyphenols is 0.1 - 3 wt%, the content of zinc oxide is 0.5 - 5 wt%, and the content of graphene oxide is 0.01 - 1 wt%. The foamed polymer matrix has a cell structure, the average cell diameter is 0.1 - 1.0 μm, and the cell density is about 10 6 ~10 8 cells / cm 2 .

[0032] Among them, the use of bio-based polymer materials can increase the carbon content in the substrate to reduce the dependence on petroleum resources. Artemisia plants such as mugwort and carex extract contain a variety of phenols and volatile oils, which have inhibitory effects on both Gram-positive / negative bacteria. In addition, artemisia essential oil has antibacterial effects on Staphylococcus aureus, Bacillus subtilis, etc. Carex extract contains volatile oils, flavonoids and phenolic acids, and experiments show that it has strong antibacterial and antioxidant properties; cinnamaldehyde, as a natural mildew-proof agent, has good inhibitory activity against common molds (such as Candida albicans, Aspergillus niger, etc.). The mass ratio of the antibacterial plant extract to cinnamaldehyde is 7-8:2-3, which can be 3 parts of artemisia extract, 4 parts of carex extract, 3 parts of cinnamaldehyde, or 4 parts of artemisia extract, 4 parts of carex extract, 2 parts of cinnamaldehyde.

[0033] In the functional additives, nano-TiO2 can improve wear resistance, light shielding and photocatalytic self-cleaning properties in the foamed polymer matrix; chitosan can enhance antibacterial, mildew-proof and adhesion forces to prevent the escape of each functional additive; tea polyphenols are polyphenolic biomolecules with good compatibility with the foamed polymer matrix, having antioxidant and metal complexation effects; zinc oxide is an antibacterial additive that can improve ultraviolet shielding and antibacterial properties in the foamed polymer matrix; graphene oxide can enhance thermal conductivity, antibacterial and mechanical strength. The content of each functional additive is the optimal content obtained from experiments.

[0034] The volatile aromatic components can be natural essential oils such as tea tree and lavender, and they have good compatibility with the polymer matrix and can be slowly released for a long time to improve the odor inside the shoes.

[0035] In one embodiment, as Figure 1 shown, a method for preparing a polymer mildew-proof and antibacterial micro-foamed breathable shoe material is provided. The method is used to prepare the polymer mildew-proof and antibacterial micro-foamed breathable shoe material as described above, and the method includes steps S11-S16:

[0036] S11: Under the protection of inert gas, add a polyester polyol with a molecular weight of 2000 and a diisocyanate mixture to the reaction kettle. The diisocyanate mixture is obtained by mixing bio-based polymeric diisocyanate and hexamethylene diisocyanate in a mass ratio of 25:75, 50:50 or 75:25.

[0037] S12: Heat the reaction kettle to 80 °C and maintain stirring until a polyurethane prepolymer with a free isocyanate group content of 8.0 ± 0.1% is prepared.

[0038] S13: Mix the polyurethane prepolymer with a chain extender in the reaction kettle. The chain extender has a hydroxyl group of 1,4-butanediol, and add 0.2 wt% of dibutyltin dilaurate catalyst, and carry out a chain extension reaction under stirring conditions.

[0039] S14: Add the antibacterial plant extract, the mildew preventive, the functional auxiliary, and the volatile aromatic component to the reaction kettle successively, and continue stirring in an 80°C environment to obtain a total mixture;

[0040] S15: Add a foaming agent to the homogenized total mixture, and continue stirring the total mixture until bubbles are generated in the total mixture;

[0041] S16: Introduce the total mixture into a mold preheated to 50°C, and apply pressure to the mold so that the material in the mold is hot-pressed into a product blank shape;

[0042] S17: Remove the prefabricated part after mold pressing of the mold, and continue to cure the product blank shape at 50°C to complete the curing of the foaming system.

[0043] Among them, as an explanation of steps S11 - S16:

[0044] In step S11, under the protection of inert nitrogen, a mixture of polyester polyol Polios55 / 20 (Mn≈2000), bio-based polymeric diisocyanate Tolonate TM XFLO100 and hexamethylene diisocyanate (HDI) is added to the reaction kettle. The diisocyanate mixture is prepared with mass ratios of bio-based diisocyanate to HDI of 25∶75, 50∶50, and 75∶25 respectively. The purpose of this step is to formulate the raw material recipe for synthesizing the prepolymer, and to exclude moisture through nitrogen protection to ensure that the isocyanate is not hydrolyzed.

[0045] In step S12, the temperature of the reaction kettle is raised to about 80°C and stirring is continued for about 4 hours. Under these conditions, the polyester polyol and the diisocyanate undergo addition polymerization to form a polyurethane prepolymer. During the reaction, the content of free isocyanate groups (–NCO) in the prepolymer is titrimetrically determined by the method of ASTM D2572 - 97 (Standard Test Method for Isocyanate Groups in Polyurethane Materials or Prepolymers). If the result is about 8.0 ± 0.1%, it indicates that the content of free isocyanate groups is sufficient. This step obtains a prepolymer with a target free - NCO content by controlling the temperature and time, providing a suitable active end (–NCO) content for the subsequent chain extension reaction.

[0046] In step S13, while maintaining the kettle temperature at about 80 °C, add the polyurethane prepolymer chain extender 1,4-butanediol (BDO) and the dibutyltin dilaurate (DBTDL) catalyst (about 0.2 wt%). Conduct the chain extension reaction under stirring conditions, and set the molar ratio of the free isocyanate groups in the polyurethane prepolymer to the chain extender to 0.95:1 to 1.10:1 to achieve a substantially equivalent ratio of end groups. The purpose of this step is to extend the molecular chain through the diol chain extender to form a high-molecular-weight polyurethane network structure and improve the mechanical strength and toughness of the material.

[0047] In step S14, after the chain extension reaction is completed, add the antibacterial plant extract, mildew-proof agent, functional additives, and volatile aromatic components to the kettle in sequence at 80 ± 2 °C, and stir evenly to disperse. The purpose is to endow the shoe material with functions such as antibacterial, mildew-proof, skin care, or fragrance, and at the same time adjust the processing performance and cell structure of the polymer through additives. Specifically, the functional additives include at least one selected from nano-TiO2, chitosan, tea polyphenols, zinc oxide, or graphene oxide. Among them, the content of nano-TiO2 is 0.5 - 5 wt%, the content of chitosan is 0.1 - 3 wt%, the content of tea polyphenols is 0.1 - 3 wt%, the content of zinc oxide is 0.5 - 5 wt%, and the content of graphene oxide is 0.01 - 1 wt%. The antibacterial plant extract is selected from wormwood powder or carex meyeriana kunth powder, or a combination of both. The mildew-proof agent is selected as cinnamaldehyde.

[0048] In step S15, add a blowing agent (such as water or a low-boiling organic solvent) to the above reaction mixture at 80 °C, and continue stirring until bubbles continuously form inside the system. The blowing agent decomposes or vaporizes under the action of temperature, releases gas, and forms a fine pore structure in the polyurethane system. This step is used to generate microcellular foam, provide lightweight and cushioning properties for the shoe material, and provide breathability. A breathable insole can reduce bacteria and prevent mildew.

[0049] In step S16, quickly pour the foamed mixture into a preheated mold (such as preheated to 40 °C and then heated to 50 °C), and apply appropriate pressure for hot pressing and forming. During the hot pressing process, the material further foams and fills the mold cavity, and at the same time, partial cross-linking and curing occur to fix the shape. Among them, a prefabricated shoe material blank is obtained through hot pressing and forming, and the mold temperature and pressure can be adjusted according to the product design.

[0050] In step S17, after the prefabricated blank is removed from the mold, place it in an environment at 50 °C for continued thermal curing for several hours (such as curing at 50 °C for 4 hours). This process enables the complete cross-linking or crystallization of the polyurethane segments, fixes the cell structure, and finally forms a stable microcellular foamed shoe material product.

[0051] In summary, the bio-based thermoplastic polyurethane elastomer synthesized by the above pre-polymerization method has good mechanical properties and sustainability characteristics. By selecting the polymerization conditions (80 °C, 4 h), the free -NCO content of the prepolymer is maintained at about 8%. In the subsequent chain extension reaction, addition of antibacterial plant extracts, addition of mildew-proof agents, addition of functional additives, and curing process, a mildew-proof and antibacterial high-molecular-weight network structure can be successfully formed. Combining the foaming agent and the hot pressing molding process, this method can obtain a shoe material blank with a uniform fine bubble structure, while ensuring the strength, elasticity, and breathability of the material.

[0052] In one embodiment, the foaming agent is one of azodicarbonamide and supercritical CO2;

[0053] As in step S14, the overall mixture containing azodicarbonamide or supercritical CO2 is high-shear mixed at 1000 - 3000 rpm for 30 seconds to 2 minutes, so that the foaming agent forms uniformly dispersed micro-nuclei in the overall mixture and generates bubbles. In step S15, when the overall mixture is injected into the mold, the pressure in the mold is maintained at 1 - 5 MPa for 10 - 60 seconds, and then quickly depressurized to 0.1 - 0.3 MPa to induce nucleation growth, forming a micro-foamed structure with an average pore diameter of 0.1 - 1.0 μm and a pore density of about 10 6 ~10 8 per cm 2 Among them, by adopting the steps of ultra-high shear (1000 - 3000 rpm) and pressure control (1 - 5 MPa → 0.1 - 0.3 MPa), a micro-porous network with a pore diameter of 100 - 1000 nm and a density of 10 6 –10 8 / cm 2 can be stably formed in the elastomer.

[0054] In one embodiment, after the product blank is cured, the product blank is subjected to laser drilling, plasma treatment, and cutting to form an insole.

[0055] Among them, after the product blank is cured, laser drilling (forming a surface honeycomb structure), atmospheric pressure plasma surface activation treatment (gas: argon / oxygen mixture, power 100 - 300 W, treatment time 30 s - 2 min), and precision numerical control cutting are successively adopted to obtain a final insole with a micro-foamed breathable structure and excellent surface adhesion. Among them, inert or active gases (argon, oxygen, nitrogen, air) are ionized by high-frequency electric fields or microwaves to form a plasma containing a large number of electrons, ions, free radicals, and ultraviolet photons; these high-energy particles bombard the surface of the insole material, removing the surface organic pollution layer and introducing various active functional groups (such as -OH, -COOH, -NH2, etc.) at the ends or side chains of the polymer molecules, so that the surface energy is significantly increased and the surface micro-roughness is controllably changed.

[0056] Beneficial effects:

[0057] By mixing bio-based diisocyanate with hexamethylene diisocyanate and using bio-based 1,4-butanediol for chain extension, the renewable carbon content therein is significantly increased, which helps to reduce the dependence on petrochemical resources, promote green synthesis processes, and the production process can be operated in the same reaction kettle, with the process simplified and convenient, improving production efficiency; by changing the mixing ratio of the diisocyanate mixture, the tensile strength and elasticity of the final product can be adjusted to adapt to complex environmental uses;

[0058] By using the synergistic effect of Artemisia or Carex meyeriana plant extracts and cinnamaldehyde in a mass ratio of 6:2 to 8:4, the material is endued with broad-spectrum antibacterial function and at the same time has mildew inhibition effect; functional additives such as nano-TiO2, chitosan, tea polyphenols, zinc oxide, graphene oxide, etc. are evenly dispersed, which can simultaneously improve the mechanical strength, wear resistance, antioxidant and self-cleaning properties of the material.

[0059] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. A polymer mildew-proof and antibacterial micro-foamed breathable shoe material, characterized in that, The shoe material includes a foamed polymer matrix, in which an antibacterial plant extract, a mildew preventive, a functional additive, and a volatile aromatic component are admixed; the antibacterial plant extract includes at least one selected from Artemisia plant extract and Carex meyeriana Kunth extract, the mildew preventive is cinnamaldehyde, the functional additive includes at least one selected from nano-TiO₂, chitosan, tea polyphenols, zinc oxide, or graphene oxide, the volatile aromatic component is a volatile natural essential oil or a fragrance component, and the foamed polymer matrix is a bio-based polymer material.

2. The polymer mildew-proof and antibacterial micro-foamed breathable shoe material according to claim 1, wherein the mass ratio of the antibacterial plant extract to cinnamaldehyde is (7-8):(2-3).

3. The polymer anti-mildew and antibacterial micro-foamed breathable shoe material according to claim 1, characterized in that, The nano-TiO₂, the chitosan, the tea polyphenols, the zinc oxide, and the graphene oxide are dispersed in the foamed polymer matrix. The content of nano-TiO₂ is 0.5-5 wt%, the content of chitosan is 0.1-3 wt%, the content of tea polyphenols is 0.1-3 wt%, the content of zinc oxide is 0.5-5 wt%, and the content of graphene oxide is 0.01-1 wt%.

4. The polymer anti-mildew and antibacterial micro-foamed breathable shoe material according to claim 1, wherein The foamed polymer matrix has a cell structure with an average cell diameter of 0.1 to 1.0 μm and a cell density of about 10 6 ~10 8 cells / cm 2 .

5. A preparation method of a polymer mildew-proof and antibacterial micro-foamed breathable shoe material, characterized in that, The method is used to prepare the polymer mildew-proof and antibacterial micro-foamed breathable shoe material according to any one of claims 1-4. The method includes steps S11-S17: S11: Under the protection of an inert gas, add a polyester polyol with a molecular weight of 2000 and a diisocyanate mixture to a reaction kettle. The diisocyanate mixture is obtained by mixing a bio-based polymeric diisocyanate and hexamethylene diisocyanate in a mass ratio of 25:75, 50:50, or 75:

25. S12: Heat the reaction kettle to 80 °C and maintain stirring until a polyurethane prepolymer with a free isocyanate group content of 8.0 ± 0.1% is obtained. S13: Mix the polyurethane prepolymer with a chain extender in the reaction kettle. The chain extender is 1,4-butanediol, and 0.2 wt% of dibutyltin dilaurate catalyst is added, and a chain extension reaction is carried out under stirring conditions. S14: Add the antibacterial plant extract, the mildew preventive, the functional additive, and the volatile aromatic component to the reaction kettle in sequence, and continue stirring in an 80 °C environment to obtain an overall mixture. S15: Add a foaming agent to the homogenized overall mixture, and continue stirring the overall mixture until the overall mixture generates bubbles. S16: Introduce the overall mixture into a mold preheated to 50 °C, and apply pressure to the mold so that the substance in the mold is hot-pressed into a product blank shape. S17: Remove the prefabricated part after mold pressing of the mold, and continue to cure the product blank shape at 50 °C to complete the curing of the foaming system.

6. The preparation method of the polymer mildew-proof and antibacterial micro-foamed breathable shoe material according to claim 5, characterized in that, The molar ratio of the free isocyanate group in the polyurethane prepolymer to the hydroxyl group of the chain extender is 0.95:1-1.10:

1.

7. The preparation method of the polymer mildew-proof and antibacterial micro-foamed breathable shoe material according to claim 5, characterized in that, When determining the content of the free isocyanate group, a titration method is used for determination.

8. The preparation method of the polymer mildew-proof and antibacterial micro-foamed breathable shoe material according to claim 5, characterized in that, The foaming agent is one of azodicarbonamide and supercritical CO₂. In step S15, the overall mixture containing the foaming agent is subjected to high-shear mixing at 1000 - 3000 rpm for 30 seconds to 2 minutes, so that the foaming agent forms uniformly dispersed minute nuclei in the overall mixture and generates bubbles.

9. The preparation method of the polymer mildew-proof and antibacterial micro-foamed breathable shoe material according to claim 5, characterized in that, In step S16, when injecting the overall mixture into the mold, a pressure of 1 to 5 MPa is maintained in the mold for 10 to 60 seconds, and then the pressure is rapidly released to 0.1 to 0.3 MPa to induce nucleation growth, forming a microcellular structure with an average pore diameter of 0.1 to 1.0 μm and a pore density of about 10 6 ~10 8 pcs / cm 2 .

10. The preparation method of the polymer anti-mildew and antibacterial micro-foamed breathable shoe material according to claim 5, wherein After the product blank is cured, laser drilling, plasma treatment and cutting are performed on the product blank to form an insole.

Images