Fabric-free insole preparation method and insole prepared by same

Abstract

The invention relates to a fabric-free insole preparation method and an insole prepared by the method, the method comprises the following steps: preparing a polyol mixture component A: mixing polyether polyol, polyester polyol, a surfactant, a catalyst and a compatilizer, putting the mixture into a container A, stirring, heating and stirring to obtain the polyol mixture component A, preparing an isocyanate prepolymer component B: mixing diphenylmethane and diisocyanate, putting the mixture into a container B, stirring, heating and stirring to obtain the isocyanate prepolymer component B, uniformly mixing the polyol mixture component A obtained in the step S1 and the isocyanate prepolymer component B obtained in the step S2 to obtain a base material mixed component, and carrying out heat treatment on the base material mixed component to obtain the polyurethane adhesive. 3, the base material mixed component obtained in the step 3 is poured into a mold, an insole precursor is obtained through autonomous foaming, the mold is opened, the insole precursor is evenly coated with the polyol mixture A component in a brushing mode to prepare the polyol mixture A component, then the mold is closed, heating and curing are conducted, and the fabric-free insole is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of insole manufacturing, and particularly relates to a method for preparing a fabricless insole and an insole made by this method. Background Art

[0002] Insoles not only improve the wearing comfort but also have various practical functions. By providing additional cushioning and support, insoles can effectively reduce the pressure on the feet during walking or exercise, preventing foot fatigue and pain. At the same time, insoles made of antibacterial materials can inhibit the growth of bacteria, reduce odors, and keep the shoe interior clean and hygienic. In addition, insoles can increase the friction between the shoes and the feet, improve stability, and reduce the risk of slipping or spraining. For specific occasions and needs, such as sports shoes, leather shoes, or high heels, choosing the right insole can provide additional functions and protection, thus extending the service life of the shoes.

[0003] The existing fabricless insoles need to have a wear-resistant layer on the surface to ensure cushioning and elasticity because their materials are relatively easy to wear. This wear-resistant layer can be artificial leather, animal skin, fiber cloth, etc., and then a polyurethane elastomer is adhered to form an insole. The wear-resistant layer is used to contact the sole instead of the polyurethane insole to avoid wear. However, the wear-resistant layer has no antibacterial and odor-proof effect, and the antibacterial and odor-proof effect of the polyurethane is isolated by the wear-resistant layer, resulting in the antibacterial, odor-proof, and deodorant effects not being effectively applied to the sole. At the same time, due to the material characteristics of the wear-resistant layer, it does not have good ductility and breathability. Therefore, there is still room for improvement in the existing technology. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing a fabricless insole in view of the above deficiencies of the existing technology.

[0005] To achieve the above object, the present invention provides the following technical solution. A method for preparing a fabricless insole, characterized by comprising the following steps:

[0006] S1. Prepare component A of the polyol mixture: Mix polyether polyol, polyester polyol, surfactant, catalyst, and compatibilizer and put them into container A for stirring. After heating and stirring, component A of the polyol mixture is obtained. The heating temperature is controlled at 40 - 60°C, the rotation speed is 50 - 80 revolutions per minute, and the stirring time is 1 - 1.5 hours;

[0007] S2. Prepare component B of the isocyanate prepolymer: Add diphenylmethane diisocyanate to container B and heat it for standby to obtain component B of the isocyanate prepolymer, where the heating temperature is 40 - 50°C;

[0008] S3. Prepare surface treatment liquid C: Put component A of the polyol mixture and silane coupling agent into container C for stirring, and surface treatment liquid C is obtained through stirring at room temperature;

[0009] S4. Mix the prepared polyol mixture component A and the isocyanate prepolymer component B obtained in steps S1 and S2 evenly to obtain a base material mixed component;

[0010] S5. Pour the base material mixed component obtained in step S3 into a mold, and through self-foaming, obtain a shoe insole precursor;

[0011] S6. Open the mold, evenly brush the surface treatment liquid C on the surface of the shoe insole precursor, then close the mold and heat and cure for 30 - 40 min, and control the heating temperature at 50 - 70 °C; obtain a fabricless shoe insole.

[0012] Adopting the above technical solution, by mixing polyether polyol, polyester polyol, surfactant, catalyst, and compatibilizer and putting them into container A for stirring, and through heating and stirring to obtain the polyol mixture component A. For the above-mentioned method for preparing a fabricless shoe insole and the shoe insole made by this method, polyether polyol is used to improve the elasticity and comfort of the shoe insole, and polyester polyol mainly acts as an adhesive to bond various materials of the shoe insole together, improving the integrity and stability of the shoe insole. The surfactant mainly plays the roles of wetting and emulsifying during the shoe insole forming process, can reduce the interfacial tension, increase the wettability of the interface, thereby improving the adhesion and permeability of the coating. The catalyst plays a role in promoting chemical reactions during the shoe insole forming process, can accelerate the cross-linking reaction between polymer molecules, and promote the curing and forming of materials; by mixing diphenylmethane and diisocyanate and putting them into container B for stirring, and through heating and stirring to obtain the isocyanate prepolymer component B. When diphenylmethane diisocyanate is formed, by reacting with components such as polyester polyol and polyether polyol, the cross-linking density of the shoe insole material can be increased, improving the elasticity and durability of the shoe insole. Then, evenly brush the treatment liquid C on the obtained shoe insole precursor and heat it to conduct a secondary surface reaction on the shoe insole precursor to form a dense and wear-resistant layer. The silane coupling agent optimizes the interfacial properties. On the one hand, it improves the interfacial bonding force between component A and the shoe insole precursor. At the same time, the hydrolysis and cross-linking of the silane can improve the interfacial cross-linking degree, thereby further improving the wear resistance of the surface. By forming a dense protective layer on the shoe insole surface, the wear and loss during daily use can be effectively reduced, and the service life of the shoe insole can be extended. This wear-resistant layer can also provide better protection, prevent the erosion of the external environment on the shoe insole material, and maintain the performance and comfort of the shoe insole. The dense layer formed by the secondary surface reaction can also enhance the waterproof and dustproof performance of the shoe insole, enabling it to maintain a good use state in various environments.

[0013] For the above-mentioned method for preparing a fabricless shoe insole, it can be further set as: when preparing the polyol mixture component A in step S1, an antibacterial agent and an anti-odor agent are also put into container A and stirred simultaneously.

[0014] With the above technical solution, the antibacterial agent can be a nano-silver antibacterial agent that effectively inhibits the growth of bacteria by destroying the bacterial cell membrane and inhibiting the activity of bacterial respiratory enzymes, keeping the insole clean and hygienic. The deodorant can be activated carbon that eliminates or reduces the odor in the insole by its adsorption performance, keeping the inside of the shoe fresh and hygienic. The antibacterial agent and the deodorant are directly formed in the polyurethane elastomer insole, enabling it to achieve an efficient antibacterial and deodorant effect after contacting the sole of the foot.

[0015] The above method for preparing a fabricless insole can be further set as follows: When preparing the polyol mixture component A in step S1, an open-cell agent and a hardening agent are also put into container A and stirred simultaneously.

[0016] With the above technical solution, the function of the open-cell agent is to form micropores during the molding of the polyurethane insole, increasing the air permeability and moisture absorption of the insole, adjusting the softness, hardness and elasticity of the insole, improving the wearing comfort, and making the insole more comfortable. The function of the hardening agent is to harden the insole, increasing its durability and abrasion resistance. By adding the hardening agent, the insole can be made more wear-resistant and wrinkle-resistant, extending its service life. By controlling the components of the open-cell agent and the hardening agent, the fabricless polyurethane antibacterial and deodorant insole has the characteristics of elasticity and comfort while also having wear-resistant properties, improving the service life of the product, enabling it to achieve wear-resistant and pressure-resistant characteristics without the need for an artificial leather-like wear-resistant layer. The open-cell agent can be an aerogel with a porous structure to improve the air permeability and moisture absorption of the insole, and the hardening agent can be a polyurethane resin to improve the durability and abrasion resistance of the insole.

[0017] The above method for preparing a fabricless insole can be further set as follows: In step S3, the silane coupling agent is selected from one or more of: γ-aminopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane.

[0018] With the above technical solution, the selection of silane coupling agents such as γ-aminopropyltriethoxysilane enhances the bonding force and adhesion between materials, improves the mechanical properties and durability of the product. The silane coupling agent can form covalent bonds, tightly combining materials with different properties, expanding the application range of materials. They also have excellent chemical stability and weather resistance, and can maintain stable performance in harsh environments, extending the service life of the product.

[0019] The above method for preparing a fabricless insole can be further set as follows: In step S3, the mass fraction of the silane coupling agent in the surface treatment liquid C is: 0.5 - 5%.

[0020] With the above technical solution, controlling the mass fraction of the silane coupling agent in the surface treatment liquid C within 0.5 - 5% can precisely optimize the surface treatment effect of the material. This proportion range ensures that the coupling agent fully plays its role, enhances the bonding force and adhesion of the material surface, and effectively improves the product performance. At the same time, it avoids problems of improper treatment caused by excessive or insufficient coupling agent, such as excessive coupling agent residue affecting the material properties or insufficient amount failing to achieve the expected effect.

[0021] The insole made by the above - mentioned method for preparing a fabric - free insole can be further configured as: including a fabric - free insole body and a dense wear - resistant layer attached to the surface of the fabric - free insole body. The fabric - free insole body is provided with a plurality of ventilation holes, and the ventilation holes are distributed in a gradient from small to large from the surface to the inside.

[0022] With the above technical solution, setting a plurality of ventilation holes inside the insole significantly improves the durability and comfort of the insole. The dense wear - resistant layer can effectively extend the service life of the insole, reduce daily wear and tear. The design of the ventilation holes ensures good ventilation performance, improves the comfort during wearing. The ventilation holes are distributed in a gradient from small to large from the surface to the inside, which helps to more effectively discharge moisture and heat, keep the inside of the shoe dry, and prevent the growth of bacteria.

[0023] The insole made by the above - mentioned method for preparing a fabric - free insole can be further configured as: the surface pore diameter range of the ventilation holes is 0.2 - 0.3 mm.

[0024] With the above technical solution, the surface pore diameter of the ventilation holes is carefully controlled within the range of 0.2 - 0.3 mm. It can not only effectively promote air circulation, enhance the air exchange inside the insole, so as to keep the feet dry and comfortable, and reduce the stuffy feeling and moisture accumulation caused by long - term wearing; at the same time, this pore diameter range can also effectively block fine particles from entering the inside of the insole, such as dust or tiny sand grains, maintaining the cleanliness and hygiene inside the insole.

[0025] The insole made by the above - mentioned method for preparing a fabric - free insole can be further configured as: the internal pore diameter range of the ventilation holes is 0.6 - 0.7 mm.

[0026] With the above technical solution, the larger internal pore diameter can more effectively promote air circulation, accelerate the gas exchange inside and outside the insole, thus significantly improving the ventilation performance, ensuring that the feet can still remain dry and comfortable during long - term wearing, effectively preventing sweating and odor. This pore diameter range can effectively balance the ventilation and structural strength while ensuring high - efficiency ventilation, ensuring that the insole maintains good durability and support while providing excellent comfort.

[0027] The beneficial effects of the present invention:

[0028] 1. Polyether polyol and polyester polyol are used as the main components, making the insole elastic and comfortable while also having the durability and abrasion resistance that were originally only possessed by the artificial leather layer. This makes the insole have a longer service life, a simpler process, and a lower cost.

[0029] 2. During the preparation process, antibacterial agents and deodorants are added, making the resulting insole have good antibacterial and deodorant effects, effectively solving problems such as foot odor and athlete's foot caused by traditional insoles being prone to getting damp and bacteria growing after sweating, and further improving foot health.

[0030] 3. By introducing a silane coupling agent, the surface treatment effect of the material can be effectively improved, the adhesion and bonding force on the material surface can be enhanced, the surface crosslinking density can be increased, and the abrasion resistance on the surface of the polyurethane material can be increased; at the same time, the porosity of the insole surface can be maintained, and the breathability of the insole can be improved.

[0031] 4. Through a systematic process step, from raw material preparation to the production of the finished insole, each step has been optimized in detail. For example, when preparing component A, antibacterial agents, deodorants, blowing agents, and hardeners are added to ensure the multifunctionality and excellent performance of the insole material, and the uniformity of the foam and the overall quality of the insole are improved through a casting mold. Detailed implementation mode

[0033] This specific embodiment is only an explanation of the present invention and does not limit the present invention. After reading this specification, those skilled in the art can make modifications without creative contributions to this embodiment as needed, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

[0034] A typical preparation method of a fabricless insole is as follows:

[0035] S1. Prepare component A of the polyol mixture: Mix polyether polyol, polyester polyol, surfactant, catalyst, and compatibilizer and put them into container A for stirring. After heating and stirring, component A of the polyol mixture is obtained. The heating temperature is controlled at 40 - 60 °C, the rotation speed is 50 - 80 revolutions per minute, and the stirring time is 1 - 1.5 hours;

[0036] S2. Prepare component B of the isocyanate prepolymer: Add diphenylmethane diisocyanate to container B and heat it for standby to obtain component B of the isocyanate prepolymer, where the heating temperature is 40 - 50 °C;

[0037] S3. Prepare surface treatment liquid C: Put component A of the polyol mixture and γ-aminopropyltriethoxysilane into container C for stirring, and obtain surface treatment liquid C through normal temperature stirring;

[0038] S4. Mix the A component of the polyol mixture obtained in steps S1 and S2 with the isocyanate prepolymer B component evenly to obtain the base material mixed component;

[0039] S5. Pour the base material mixed component obtained in step S3 into a mold and perform self-foaming to obtain the insole precursor;

[0040] S6. Open the mold, evenly brush the surface treatment liquid C on the insole precursor, then close the mold and heat and cure for 30 - 40 min, with the heating temperature controlled at 50 - 70 °C; obtain the fabricless insole.

[0041] Example 1

[0042] S1. Prepare the A component of the polyol mixture: Mix polyether polyol, polyester polyol, surfactant, catalyst, and compatibilizer and put them into container A for stirring. After heating and stirring, obtain the A component of the polyol mixture, with the heating temperature controlled at 40 °C, the rotation speed being 50 revolutions per minute, and the stirring time being 1 hour;

[0043] S2. Prepare the B component of the isocyanate prepolymer: Add diphenylmethane diisocyanate to container B and heat it for standby to obtain the B component of the isocyanate prepolymer, where the heating temperature is 40 °C;

[0044] S3. Prepare the surface treatment liquid C: Mix the A component of the polyol mixture and vinyltriethoxysilane and put them into container C for stirring. After stirring at room temperature, obtain the surface treatment liquid C;

[0045] S4. Mix the A component of the polyol mixture obtained in steps S1 and S2 with the isocyanate prepolymer B component evenly to obtain the base material mixed component;

[0046] S5. Pour the base material mixed component obtained in step S3 into a mold and perform self-foaming to obtain the insole precursor;

[0047] S6. Open the mold, evenly brush the surface treatment liquid C on the insole precursor, then close the mold and heat and cure for 30 min, with the heating temperature controlled at 50 °C; obtain the fabricless insole.

[0048] Example 2

[0049] S1. Prepare the A component of the polyol mixture: Mix polyether polyol, polyester polyol, surfactant, catalyst, and compatibilizer and put them into container A for stirring. After heating and stirring, obtain the A component of the polyol mixture, with the heating temperature controlled at 50 °C, the rotation speed being 60 revolutions per minute, and the stirring time being 1.5 hours;

[0050] S2. Preparation of the isocyanate prepolymer B component: Add diphenylmethane diisocyanate to container B and heat it for standby to obtain the isocyanate prepolymer B component, where the heating temperature is 45°C.

[0051] S3. Preparation of the surface treatment liquid C: Put the polyol mixture A component and γ-glycidoxypropyltrimethoxysilane into container C and stir. After stirring at room temperature, obtain the surface treatment liquid C.

[0052] S4. Mix the prepared polyol mixture A component and isocyanate prepolymer B component obtained in steps S1 and S2 evenly to obtain the substrate mixed component.

[0053] S5. Pour the substrate mixed component obtained in step S3 into a mold and let it foam spontaneously to obtain the insole precursor.

[0054] S6. Open the mold, evenly brush the surface treatment liquid C on the insole precursor, then close the mold and heat and cure for 35 minutes, with the heating temperature controlled at 55°C; obtain the fabricless insole.

[0055] Example 3

[0056] S1. Preparation of the polyol mixture A component: Put polyether polyol, polyester polyol, surfactant, catalyst, and compatibilizer into container A and stir. After heating and stirring, obtain the polyol mixture A component, with the heating temperature controlled at 60°C, the rotation speed being 80 revolutions per minute, and the stirring time being 1.5 hours.

[0057] S2. Preparation of the isocyanate prepolymer B component: Add diphenylmethane diisocyanate to container B and heat it for standby to obtain the isocyanate prepolymer B component, where the heating temperature is 50°C.

[0058] S3. Preparation of the surface treatment liquid C: Put the polyol mixture A component and silane coupling agent into container C and stir. After stirring at room temperature, obtain the surface treatment liquid C.

[0059] S4. Mix the prepared polyol mixture A component and isocyanate prepolymer B component obtained in steps S1 and S2 evenly to obtain the substrate mixed component.

[0060] S5. Pour the substrate mixed component obtained in step S3 into a mold and let it foam spontaneously to obtain the insole precursor.

[0061] S6. Open the mold, evenly brush the surface treatment liquid C on the insole precursor, then close the mold and heat and cure for 40 minutes, with the heating temperature controlled at 60°C; obtain the fabricless insole.

[0062] Test the various properties of the fabricless polyurethane antibacterial and deodorant insoles obtained in Examples 1 - 3:

[0063] 1. Wear resistance performance test reference standard: GB / T 21196.3 - 2007: Determination of mass loss

[0064] Test method: Use a wear resistance testing machine. Place the insole on the test bench and apply a certain pressure and frictional force for cyclic friction testing.

[0065] 2. Air permeability performance test reference standard: GB / T 5453 - 1997 Determination of air permeability of textiles

[0066] Test method: Use an air permeability tester. Place the insole in the test device and measure the air flow rate passing through the insole per unit time.

[0067] Data obtained from Example 1:

[0068] Wear resistance performance: After 5000 cycles of friction testing, the mass loss of the insole is less than 3%, indicating excellent wear resistance performance.

[0069] Air permeability rate: 700 mm / s, indicating good air permeability performance of the insole.

[0070] Data obtained from Example 2:

[0071] Wear resistance performance: After 5000 cycles of friction testing, the mass loss of the insole is less than 2%, indicating excellent wear resistance performance.

[0072] Air permeability rate: 900 mm / s, indicating excellent air permeability performance of the insole.

[0073] Data obtained from Example 3:

[0074] Wear resistance performance: After 5000 cycles of friction testing, the mass loss of the insole is less than 5%, indicating good wear resistance performance.

[0075] Air permeability rate: 750 mm / s, indicating good air permeability performance of the insole.

[0076] Abrasion resistance Air permeability Implementation 1 Mass loss is less than 3% 700 mm / s Implementation 2 Mass loss is less than 2% 900 mm / s Implementation 3 Mass loss is less than 5% 750 mm / s

[0077] Comparative Example 1

[0078] S1. Preparation of polyol mixture component A: Mix polyether polyol, polyester polyol, surfactant, catalyst, and compatibilizer and put them into container A for stirring. After heating and stirring, obtain polyol mixture component A. The heating temperature is controlled at 40°C, the rotation speed is 50 revolutions per minute, and the stirring time is 1 hour;

[0079] S2. Preparation of isocyanate prepolymer component B: Add diphenylmethane diisocyanate to container B and heat it for standby to obtain isocyanate prepolymer component B, where the heating temperature is 40°C;

[0080] S3. Mix the A component of the polyol mixture obtained in steps S1 and S2 with the isocyanate prepolymer B component evenly to obtain the base material mixed component;

[0081] S4. Pour the base material mixed component obtained in step S3 into a mold and let it foam spontaneously to obtain the insole precursor;

[0082] S5. Open the mold and evenly apply the top coat on the insole precursor.

[0083] Comparative Example 2

[0084] S1. Prepare the A component of the polyol mixture: Mix polyether polyol, polyester polyol, surfactant, catalyst, and compatibilizer and put them into container A for stirring. After heating and stirring, obtain the A component of the polyol mixture. The heating temperature is controlled at 50 °C, the rotation speed is 60 revolutions per minute, and the stirring time is 1.5 hours;

[0085] S2. Prepare the isocyanate prepolymer B component: Add diphenylmethane diisocyanate to container B and heat it for standby to obtain the isocyanate prepolymer B component, where the heating temperature is 45 °C;

[0086] S3. Mix the A component of the polyol mixture obtained in steps S1 and S2 with the isocyanate prepolymer B component evenly to obtain the base material mixed component;

[0087] S4. Pour the base material mixed component obtained in step S3 into a mold and let it foam spontaneously to obtain the insole precursor;

[0088] S5. Open the mold and evenly apply the top coat on the insole precursor.

[0089] Comparative Example 3

[0090] S1. Prepare the A component of the polyol mixture: Mix polyether polyol, polyester polyol, surfactant, catalyst, and compatibilizer and put them into container A for stirring. After heating and stirring, obtain the A component of the polyol mixture. The heating temperature is controlled at 60 °C, the rotation speed is 80 revolutions per minute, and the stirring time is 1.5 hours;

[0091] S2. Prepare the isocyanate prepolymer B component: Add diphenylmethane diisocyanate to container B and heat it for standby to obtain the isocyanate prepolymer B component, where the heating temperature is 50 °C;

[0092] S3. Mix the A component of the polyol mixture obtained in steps S1 and S2 with the isocyanate prepolymer B component evenly to obtain the base material mixed component;

[0093] S4. Pour the base material mixture components obtained in step S3 into a mold, and obtain a pre-insole through self-foaming.

[0094] S5. Open the mold and evenly apply a topcoat on the pre-insole.

[0095] Test data of directly applying a paint film to the insole

[0096] Abrasion resistance Air permeability Comparative Example 1 Mass loss is less than 4% 400 mm / s Comparative Example 2 Mass loss is less than 6% 500 mm / s Comparative Example 3 Mass loss is less than 6% 350 mm / s

[0097] Beneficial effects:

[0098] By introducing a silane coupling agent, the surface treatment effect of the material can be effectively improved, the bonding force and adhesion of the material surface can be enhanced, the surface crosslinking density can be increased, and the wear resistance of the polyurethane material surface can be increased; compared with the insole directly coated with a paint film, it still maintains excellent wear resistance, and at the same time, the ventilation holes are distributed in a gradient from small to large from the surface to the inside, ensuring good air permeability and improving the comfort during wearing.

Claims

1. A method for preparing a fabric-free insole, characterized in that: The steps include: S1. Prepare component A of a polyol mixture: mix polyether polyol, polyester polyol, surfactant, catalyst and compatibilizer into container A and stir, and obtain component A of a polyol mixture by heating and stirring. The heating temperature is controlled at 40-60° C., the rotation speed is 50-80 rpm, and the stirring time is 1-1.5 hours; S2, preparing isocyanate prepolymer component B: adding diphenylmethane diisocyanate into container B and heating for standby use, thereby obtaining isocyanate prepolymer component B, wherein the heating temperature is 40-50° C.; S3, preparing surface treatment liquid C: adding component A of the polyol mixture and a silane coupling agent into a container C and stirring at room temperature to obtain a surface treatment liquid C; S4, uniformly mixing the polyol mixture component A obtained in step S1 and step S2 with the isocyanate prepolymer component B to obtain a substrate mixed component; S5, pouring the mixed components of the substrate obtained in step S3 into a mold, and subjecting it to self-foaming to obtain a shoe insole precursor. S6, opening the mold, brushing the surface treatment liquid C evenly on the insole precursor, and then heating and curing for 30-40 minutes after closing the mold, with the heating temperature controlled at 50-70° C. to obtain the fabric-free insole.

2. The method for preparing a fabric-free insole according to claim 1, characterized in that: When preparing the polyol mixture component A in step S1, the process also includes adding an antibacterial agent and a deodorant into the container A while stirring.

3. The method for preparing a fabric-free insole according to claim 1, characterized in that: When preparing the polyol mixture component A in step S1, the process also includes adding a cell opener and a hardener into the container A and stirring them simultaneously.

4. The method for preparing a fabric-free insole according to claim 1, characterized in that: In step S3, the silane coupling agent is selected from one or more of γ-aminopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-methacryloxypropyltrimethoxysilane.

5. The method for preparing a fabric-free insole according to claim 1, characterized in that: In the step S3, the mass fraction of the silane coupling agent in the surface treatment liquid C is 0.5-5%.

6. The insole made by the method for preparing a fabric-free insole according to any one of claims 1 to 5, characterized in that: The invention comprises a non-fabric insole pad body and a porous wear-resistant layer attached to the surface of the non-fabric insole pad body. The upper surface of the non-fabric insole pad body presents air holes, and the air holes are distributed in a gradient from small to large from the surface to the inside.

7. The insole made by the method for preparing a fabric-free insole according to claim 6 is characterized in that: The pore diameter of the air-permeable hole surface ranges from 0.2 to 0.3 mm.

8. The insole made by the method for preparing a fabric-free insole according to claim 6, characterized in that: The inner diameter of the air holes ranges from 0.6 to 0.7 mm.