A method of manufacturing a shoe sole

Abstract

The application relates to the field of high polymer materials, and particularly discloses a preparation method of a shoe sole, which comprises the following steps: S1, bonding a joint layer on the surface of a bottom sheet to obtain a semi-finished product; S2, placing the semi-finished product into a foaming forming mold, and punching ETPU foaming particles into the mold, so that the ETPU foaming particles form a foaming layer through foaming forming, and a finished product shoe sole is obtained; the joint layer comprises the following raw materials in parts by weight: EVA particles 40-60 parts, TPR particles 15-25 parts, maleic anhydride grafted POE 10-25 parts, filler particles 10-18 parts, and an antioxidant 1-2 parts; the preparation method is time-saving and labor-saving, and the shoe sole has the advantages of structural stability.

Description

Technical Field

[0001] This application relates to the field of polymer materials, and more specifically, it relates to a method for preparing a shoe sole. Background Technology

[0002] There are many types of materials used for shoe soles, which can be divided into two categories: natural soles and synthetic soles. Natural soles include natural leather, bamboo, wood, etc., while synthetic soles include rubber, plastic, recycled leather, elastic cardboard, etc. As people's requirements for shoe sole comfort are increasing, highly elastic and highly resilient soles are gradually becoming more popular.

[0003] Rubber foam soles are made from natural or synthetic rubber and are widely used in sneakers, athletic shoes, hiking shoes, casual shoes, etc. They have the advantages of good elasticity, good tear resistance, aging resistance, corrosion resistance, and good electrical insulation.

[0004] In existing technologies, the bonding method between foam soles and outsoles is generally to manufacture the outsoles and foam soles separately and then bond them together with glue. This is not only time-consuming and labor-intensive, but also easily affects the bonding compatibility between the outsoles and foam soles, which can easily affect the stability of the sole structure.

[0005] Therefore, how to manufacture a shoe sole in a time-saving and labor-saving manner, while also ensuring its structural stability, is a problem that needs to be solved. Summary of the Invention

[0006] In order to prepare a shoe sole in a time-saving and labor-saving manner, and to make the shoe sole have the advantage of good structural stability, this application provides a method for preparing a shoe sole.

[0007] This application provides a method for preparing a shoe sole, which adopts the following technical solution:

[0008] A method for preparing a shoe sole includes the following steps:

[0009] S1. A bonding layer is bonded to the surface of the film to obtain a semi-finished product;

[0010] S2. Place the semi-finished product into the foaming mold, inject ETPU foam particles into the mold, and after foaming, the ETPU foam particles form a foam layer to obtain the finished shoe sole.

[0011] The bonding layer comprises the following raw materials in parts by weight: 40-60 parts EVA particles, 15-25 parts TPR particles, 10-25 parts maleic anhydride-grafted POE, 10-18 parts filler particles, and 1-2 parts antioxidant.

[0012] By adopting the above technical solution, the bonding layer can be compatible with and bonded to EPTU foam particles during the foaming process, thereby achieving one-time bonding, reducing assembly steps, improving production efficiency, and improving the structural stability of the sole through one-time molding, thereby increasing the strength of the sole.

[0013] The bonding layer combines EVA particles, maleic anhydride-grafted POE, filler particles, antioxidants, and ETPU foam particles. The adhesive properties of the EVA particles, combined with the compatibility-enhancing properties of the maleic anhydride-grafted POE, not only improve the bonding effect between the bonding layer and the ETPU foam layer, but also facilitate the stable bonding of the filler particles within the bonding layer. This enhances the bonding stability between the filler particles and the ETPU foam layer, further improving the structural stability of the sole. The finished sole exhibits both good elasticity and strength. Furthermore, the filling effect of the filler particles further improves the abrasion resistance of the finished sole material, and the antioxidants enhance the antioxidant properties of the finished sole, extending its service life.

[0014] Preferably, the filler particles are composed of mullite microparticles, nano-zirconia and hydrophobic bamboo powder in a mass ratio of 1:1-2:0.5-1.

[0015] By adopting the above technical solution, since EPTU is not resistant to high temperature and ultraviolet rays, in the hot summer, the temperature of asphalt pavement is very high. In addition, with the high temperature of ultraviolet radiation, when the sole of the shoe is frequently in contact with the high temperature asphalt pavement, EPTU is prone to hardening, becoming brittle and losing elasticity, which leads to a shortened service life of the sole on high temperature pavement.

[0016] The combination of mullite microparticles, nano-zirconia, and hydrophobic bamboo powder, along with the stacking and filling effect of the mullite microparticles and nano-zirconia and their good thermal insulation properties, gives the bonding layer excellent thermal insulation. The numerous pores in the hydrophobic bamboo powder further dissipate excess heat through these pores, further enhancing the cooling and thermal insulation effect of the bonding layer. This not only gives the bonding layer good high-temperature resistance but also, through its thermal insulation effect, minimizes the impact of high temperatures on the foam layer. Therefore, even when the sole is in prolonged contact with hot asphalt pavement in the hot summer, it is less likely to harden, become brittle, lose elasticity, or reduce strength, thus ensuring the lifespan of the sole on high-temperature roads.

[0017] The combination of mullite microparticles, nano-silica, and hydrophobic bamboo powder utilizes the layered filling effect of mullite microparticles and nano-silica to improve the density of the bonding layer while leveraging their high mechanical strength to further enhance the strength and abrasion resistance of the sole. The hydrophobicity of the mullite microparticles, nano-silica, and hydrophobic bamboo powder also improves the waterproofing of the bonding layer. Furthermore, in the sole structure, the sole plate is the bottom layer, followed by the bonding layer, and then the foam layer. By utilizing the water-blocking effect of the bonding layer, it minimizes the penetration of water from lower levels into the foam layer, thereby improving the waterproofing of the sole.

[0018] Preferably, the mullite microparticles are composed of mullite powder and triethylenetetramine solution in a mass ratio of 1:0.1-0.25.

[0019] By adopting the above technical solution, mullite powder and triethylenetetramine solution are combined, and triethylenetetramine is loaded on the surface of mullite powder. The amino groups of triethylenetetramine on the surface of mullite powder are combined with the isocyanate groups in ETPU foam particles to improve the bonding stability between mullite powder and foam layer, and also to improve the dispersion stability between mullite powder and bonding layer, thereby improving the structural stability of the sole and thus improving the mechanical strength and wear resistance of the sole and extending its service life.

[0020] Preferably, the nano-zirconia is composed of zirconium dioxide powder and hydroxyethyl cellulose solution in a mass ratio of 1:0.1-0.3.

[0021] By adopting the above technical solution, zirconium dioxide powder and hydroxyethyl cellulose solution are combined. The hydroxyl groups in the hydroxyethyl cellulose on the surface of zirconium dioxide powder are combined with the isocyanate groups in ETPU to improve the bonding stability between nano zirconium dioxide and the foam layer. This improves the bonding stability between the bonding layer and the foam layer, so that the finished shoe sole has good mechanical strength, good wear resistance and long service life.

[0022] Preferably, the hydrophobic bamboo powder is prepared by modifying bamboo powder with the hydrophobic agent KH-570.

[0023] By adopting the above technical solution, bamboo powder and silane coupling agent KH-570 are combined. The porous water absorption of bamboo powder facilitates the adsorption of silane coupling agent KH-570 by bamboo powder, thereby giving bamboo powder a hydrophobic effect, but the porous structure is still retained in the hydrophobic bamboo powder.

[0024] On the one hand, the hydrophobic bamboo powder in contact with the sole utilizes its porous structure to facilitate heat dissipation through the pores of the bonding layer. Combined with the thermal insulation effect of the bamboo powder itself, this further enhances the thermal insulation effect of the bonding layer. This not only minimizes the impact of high-temperature asphalt pavement on the foam layer but also improves the durability of the sole. On the other hand, the hydrophobic bamboo powder in contact with the foam layer formed by ETPU foam particles utilizes its porous structure to improve the bonding compatibility between the bonding layer and the foam layer, thereby further enhancing the stability of the sole structure.

[0025] Preferably, the ETPU foam particles contain the following raw materials in parts by weight: 30-50 parts polyester polyol, 20-40 parts polyether polyol, 25-45 parts isocyanate, 5-10 parts foaming agent, 2-6 parts chain extender, 0.5-1 part antioxidant, 2-8 parts heat-resistant filler, and 5-10 parts maleic anhydride-grafted EVA.

[0026] By adopting the above technical solution, polyester polyol, polyether polyol, isocyanate, maleic anhydride-grafted EVA, heat-resistant filler, and bonding layer are combined. The isocyanate combines with hydroxyl groups and other substances in the bonding layer, and the adhesive compatibility between maleic anhydride-grafted EVA and the bonding layer, as well as the adhesiveness generated by the bonding layer during the foaming process, results in good bonding stability between the bonding layer and the foam layer. At the same time, the high strength and heat insulation and heat resistance of the filler particles in the bonding layer and the heat-resistant particles in the foam layer are utilized to further improve the heat resistance and wear resistance of the sole, thereby extending the service life of the sole in high-temperature environments.

[0027] Preferably, the heat-resistant filler is composed of barium stearate and silicon dioxide in a mass ratio of 1:0.6-1.5.

[0028] By adopting the above technical solution, barium stearate and silica are combined. The heat resistance and aging resistance of barium stearate are combined with the heat insulation and filling effect of silica to further improve the heat resistance of the foam layer. In addition, barium stearate has a certain degree of lubricity, which facilitates the molding of the foam layer. At the same time, silica is compatible and bonded with the silane coupling agent KH-570 on the surface of hydrophobic bamboo powder, thereby further improving the structural stability of the shoe sole material.

[0029] Preferably, the foaming agent is composed of sodium bicarbonate and polyethylene glycol in a mass ratio of 1:1-3.

[0030] By adopting the above technical solution, sodium bicarbonate and polyethylene glycol are combined. The gas-generating effect of sodium bicarbonate when heated and the foaming effect of polyethylene glycol are utilized to further improve the foaming effect of the foam layer. Furthermore, the hydroxyl groups at both ends of polyethylene glycol not only improve the foaming effect but also enhance the bonding stability between the foam layer and the bonding layer, thereby improving the structural stability of the shoe sole.

[0031] Preferably, the antioxidant is composed of antioxidant 1010 and ultraviolet absorber UV-971 in a mass ratio of 1:1-3.

[0032] By adopting the above technical solutions, the soles of the shoes have better aging resistance, thereby minimizing the aging caused by conditions such as oxygen, ultraviolet rays, and high temperatures, and ensuring that the soles still have a long service life when used on high-temperature roads.

[0033] Preferably, the chain extender is 1,4-butanediol.

[0034] By adopting the above technical solution, the combination of 1,4-butanediol and polyethylene glycol can further increase the hydroxyl chain, and after polymerization with isocyanate, a foam layer with high density and good wear resistance is formed, thereby improving the structural stability of the shoe sole while improving the strength and wear resistance of the shoe sole.

[0035] In summary, this application has the following beneficial effects:

[0036] 1. The bonding layer can be compatible with and bonded to EPTU foam particles during the foaming process, thereby achieving one-time bonding, reducing assembly steps, improving production efficiency, and also improving the structural stability of the sole through one-time molding.

[0037] 2. The combination of mullite microparticles, nano-zirconia, and hydrophobic bamboo powder, through its heat insulation effect, can minimize the impact of high temperatures on the foam layer. This ensures that even when the sole is in prolonged contact with hot asphalt roads in the hot summer, it is less likely to harden, become brittle, or lose elasticity, thus guaranteeing the lifespan of the sole on high-temperature roads. Furthermore, it can block moisture, preventing water from the lower surface from entering the foam layer through the bonding layer, thereby improving the waterproof effect of the sole.

[0038] 3. Mullite powder, triethylenetetramine solution, zirconium dioxide powder, hydroxyethyl cellulose solution, and ETPU foam particles are combined to improve the adhesion between mullite powder and zirconium dioxide powder and the foam layer, thereby improving the structural stability and wear resistance of the shoe sole. Detailed Implementation

[0039] The present application will be further described in detail below with reference to the embodiments.

[0040] Example of preparation of mullite microparticles

[0041] Preparation Example 1: Mullite microparticles were prepared by the following method:

[0042] Weigh out triethylenetetramine and dissolve it in water by stirring to prepare a 5% triethylenetetramine solution;

[0043] 0.18 kg of triethylenetetramine solution was uniformly sprayed onto the surface of 1 kg of mullite powder, and then uniformly dispersed, dried, and broken up to obtain finished mullite microparticles; the particle size of the mullite microparticles was sieved through a 400-mesh sieve.

[0044] Preparation Example 2: The difference between this preparation example and Preparation Example 1 is that:

[0045] 0.1 kg of triethylenetetramine solution was uniformly sprayed onto the surface of 1 kg of mullite powder, and then uniformly dispersed, dried, and broken up to obtain finished mullite microparticles; the particle size of the mullite microparticles was such that they passed through a 400-mesh sieve.

[0046] Preparation Example 3: The difference between this preparation example and Preparation Example 1 is that:

[0047] 0.25 kg of triethylenetetramine solution was uniformly sprayed onto the surface of 1 kg of mullite powder, and then uniformly dispersed, dried, and broken up to obtain finished mullite microparticles; the particle size of the mullite microparticles was sieved through a 400-mesh sieve.

[0048] Preparation example of nano-zirconia

[0049] Preparation Example 4: Nano-zirconia was prepared using the following method:

[0050] Weigh out hydroxyethyl cellulose and place it in water, stirring until completely dissolved to obtain a 0.5% hydroxyethyl cellulose solution.

[0051] 0.2 kg of hydroxyethyl cellulose solution was uniformly sprayed onto the surface of 1 kg of zirconium dioxide powder. After uniform dispersion, drying, and dispersing, finished nano zirconium dioxide was obtained with a particle size of 100 nm.

[0052] Preparation Example 5: The difference between this preparation example and Preparation Example 4 is that:

[0053] A 0.1 kg hydroxyethyl cellulose solution was uniformly sprayed onto the surface of 1 kg zirconium dioxide powder, and then uniformly dispersed, dried, and broken up to obtain the finished nano zirconium dioxide with a particle size of 100 nm.

[0054] Preparation Example 6: The difference between this preparation example and Preparation Example 4 is that:

[0055] 0.3 kg of hydroxyethyl cellulose solution was uniformly sprayed onto the surface of 1 kg of zirconium dioxide powder, and then uniformly dispersed, dried, and broken up to obtain finished nano zirconium dioxide with a particle size of 100 nm.

[0056] Preparation example of hydrophobic bamboo powder

[0057] Preparation Example 7: Hydrophobic bamboo powder was prepared by the following method:

[0058] 1 kg of bamboo powder was placed in 5 kg of silane coupling agent KH-570 and dispersed and stirred at 1000 r / min for 30 min. The bamboo powder was then filtered out and passed through a 200 mesh sieve. After crushing, drying and dispersing, the finished hydrophobic bamboo powder was obtained and passed through a 1500 mesh sieve.

[0059] Example of ETPU foaming particle preparation

[0060] Preparation Example 8: ETPU foam particles:

[0061] The composition includes 40 kg of polyester polyol, 30 kg of polyether polyol, 35 kg of isocyanate, 8 kg of foaming agent, 4 kg of chain extender, 0.8 kg of antioxidant, 5 kg of heat-resistant filler, and 8 kg of maleic anhydride-grafted EVA. The polyester polyol is polyethylene adipate diol; the polyether polyol is polytetrahydrofuran ether diol; the isocyanate is isoflurane diisocyanate; the foaming agent is composed of sodium bicarbonate and polyethylene glycol in a 1:1.5 mass ratio, and the polyethylene glycol is polyethylene glycol 4000; the chain extender is 1,4-butanediol; the antioxidant is composed of antioxidant 1010 and ultraviolet absorber UV-971 in a 1:1.5 mass ratio; and the heat-resistant filler is composed of barium stearate and silica in a 1:1 mass ratio, with a particle size of 40 μm.

[0062] The preparation method is as follows:

[0063] Polyester polyol, polyether polyol, chain extender, heat-resistant filler, and maleic anhydride-grafted EVA were mixed and stirred evenly. Then, isocyanate, foaming agent, and antioxidant were added and mixed evenly. Granulation was then carried out to obtain ETPU foam particles. The granulation temperature was 220℃, the pressure was 5MPa, and the particle size of the ETPU foam particles was 2mm.

[0064] Preparation Example 9: The difference between this preparation example and Preparation Example 8 is that:

[0065] The composition includes 30 kg of polyester polyol, 20 kg of polyether polyol, 25 kg of isocyanate, 5 kg of foaming agent, 2 kg of chain extender, 0.5 kg of antioxidant, 2 kg of heat-resistant filler, and 5 kg of maleic anhydride-grafted EVA. The foaming agent is composed of sodium bicarbonate and polyethylene glycol in a 1:1 mass ratio. The antioxidant is composed of antioxidant 1010 and ultraviolet absorber UV-971 in a 1:1 mass ratio. The heat-resistant filler is composed of barium stearate and silica in a 1:0.6 mass ratio.

[0066] Preparation Example 10: The difference between this preparation example and Preparation Example 8 is that:

[0067] The composition includes 50 kg of polyester polyol, 40 kg of polyether polyol, 45 kg of isocyanate, 10 kg of foaming agent, 6 kg of chain extender, 1 kg of antioxidant, 8 kg of heat-resistant filler, and 10 kg of maleic anhydride-grafted EVA. The foaming agent is composed of sodium bicarbonate and polyethylene glycol in a mass ratio of 1:3. The antioxidant is composed of antioxidant 1010 and ultraviolet absorber UV-971 in a mass ratio of 1:3. The heat-resistant filler is composed of barium stearate and silica in a mass ratio of 1:1.5.

[0068] Example

[0069] The EVA granules in the following raw materials were purchased from Thai petrochemical EVA sold by Yuyao Fulin Plastics Co., Ltd., with brand name SV1055 and VA content of 28%; the TPR granules were purchased from Dongguan Dongying Plastics Co., Ltd., with product number DY; other raw materials and equipment were all commercially available.

[0070] Example 1: A method for preparing a shoe sole:

[0071] S1. Weigh 50 kg of EVA particles, 20 kg of TPR particles, 18 kg of maleic anhydride-grafted POE, 15 kg of filler particles, and 1.5 kg of antioxidant, mix and stir evenly, and heat to 180°C to obtain a binder liquid. The filler particles are composed of mullite microparticles prepared in Preparation Example 1, nano-zirconia prepared in Preparation Example 4, and hydrophobic bamboo powder prepared in Preparation Example 7, with a mass ratio of 1:1.4:0.8. The antioxidant is composed of antioxidant 1010 and ultraviolet absorber UV-971, with a mass ratio of 1:1. The binder liquid is evenly coated on the surface of a rubber film with a thickness of 0.3 cm. After the binder liquid dries, a bonding layer is formed with a thickness of 0.3 cm, and a semi-finished product is obtained.

[0072] S2. Place the semi-finished product into the foaming mold, install the mold on the molding machine, inject the ETPU foam particles prepared in Preparation Example 8 into the mold, heat and pressurize the particles in the mold with steam at a temperature of 180°C for 100 seconds to complete the foaming process, and form a foam layer with a thickness of 2.4 cm to obtain the finished shoe sole.

[0073] Example 2: The difference between this example and Example 1 is that:

[0074] S1. Weigh 40 kg of EVA particles, 15 kg of TPR particles, 10 kg of maleic anhydride-grafted POE, 10 kg of filler particles, and 1 kg of antioxidant, mix and stir evenly, and heat to 180°C to obtain a binder liquid. The filler particles are composed of mullite microparticles prepared in Preparation Example 2, nano-zirconia prepared in Preparation Example 5, and hydrophobic bamboo powder prepared in Preparation Example 7, with a mass ratio of 1:1:0.5. The ETPU foaming particles are selected from the ETPU foaming particles prepared in Preparation Example 9.

[0075] Example 3: The difference between this example and Example 1 is that:

[0076] S1. Weigh 60 kg of EVA particles, 25 kg of TPR particles, 25 kg of maleic anhydride-grafted POE, 18 kg of filler particles, and 2 kg of antioxidant, mix and stir evenly, and heat to 180°C to obtain a binder liquid. The filler particles are composed of mullite microparticles prepared in Preparation Example 3, nano-zirconia prepared in Preparation Example 6, and hydrophobic bamboo powder prepared in Preparation Example 7, with a mass ratio of 1:2:1. The ETPU foaming particles are selected from the ETPU foaming particles prepared in Preparation Example 10.

[0077] Example 4: The difference between this example and Example 1 is that:

[0078] No hydrophobic bamboo powder was added to the filler particles.

[0079] Example 5: The difference between this example and Example 1 is that:

[0080] Mullite microparticles are replaced with an equal mass of mullite powder in the filler particles, and nano-zirconia is replaced with an equal mass of zirconia powder.

[0081] Example 6: The difference between this example and Example 1 is that:

[0082] In the mullite microparticles, the triethylenetetramine solution was replaced with an equal mass of ethyl cellulose solution, which was a 0.5% ethyl cellulose ethanol solution. In the nano-zirconia, the hydroxyethyl cellulose solution was replaced with an equal mass of ethyl cellulose solution, which was a 0.5% ethyl cellulose ethanol solution.

[0083] Example 7: The difference between this example and Example 1 is that:

[0084] No heat-resistant filler was added to the ETPU foam particles.

[0085] Example 8: The difference between this example and Example 1 is that:

[0086] The heat-resistant filler in ETPU foam particles is silica.

[0087] Example 9: The difference between this example and Example 1 is that:

[0088] Barium stearate was not added to the foaming agent in the ETPU foam particles.

[0089] Example 10: The difference between this example and Example 1 is that:

[0090] No maleic anhydride-grafted EVA was added to the ETPU foam particles.

[0091] Comparative Example

[0092] Comparative Example 1: The difference between this comparative example and Example 1 is that:

[0093] No filler particles were added to the bonding layer.

[0094] Comparative Example 2: This comparative example differs from Example 1 in that:

[0095] Maleic anhydride-grafted POE was not added to the bonding layer.

[0096] Performance testing

[0097] 1. Tensile strength test

[0098] Finished shoe soles were prepared using the preparation methods of Examples 1-10 and Comparative Examples 1-2, respectively. The tensile strength of the finished products was tested according to GB / T6344-2008, and the data were recorded.

[0099] 2. Bending resistance test

[0100] Finished shoe soles were prepared using the preparation methods of Examples 1-3, 5, 10 and Comparative Example 2, respectively. An opening with a length of 4 mm and a depth of 1 mm was cut into the surface of the shoe sole. The shoe sole was bent along the direction of the cut, and one bend was completed when the two ends of the shoe sole touched each other. After 300,000 bends, the length of the opening was measured again.

[0101] 3. Rebound rate test

[0102] Finished shoe soles were prepared using the preparation methods of Examples 1-3, 5-6, 10 and Comparative Example 2, respectively. The rebound rate was tested and the data were recorded in accordance with GB / T1681-2009.

[0103] 4. Aging resistance test

[0104] Finished shoe soles were prepared using the preparation methods of Examples 1-10 and Comparative Examples 1-2, respectively, with reference to HGT3689-2001 Test Method for Yellowing Resistance of Footwear;

[0105] Irradiate the covered area for 8 hours under a bulb with a wavelength of 240-380nm for ultraviolet light, and then evaluate the yellowing level of the covered area under a standard multi-source color matching lamp. Record the data of Examples 1-3.

[0106] The heating plate was heated to 80°C, and then the sole was placed on the heating plate with the foam layer facing upwards. After 48 hours, the tensile strength of Examples 1-10 and Comparative Examples 1-2 was tested again, and the data were recorded.

[0107] 5. Abrasion resistance test

[0108] Finished shoe soles were prepared using the methods described in Examples 1-7 and Comparative Example 1, respectively. The abrasion resistance of the shoe soles was tested in accordance with GB / T9867-2008, and the wear volume was recorded.

[0109] 6. Waterproofing test

[0110] Finished shoe soles were prepared using the methods described in Examples 1-3, respectively. The shoe soles were then soaked in water at a temperature of 60°C and a water level of 0.4 cm for 12 hours. The foaming layer on the shoe sole was then observed to determine if yellowing occurred.

[0111] Table 1 Performance Test Table

[0112]

[0113]

[0114] As can be seen from Examples 1-3 and Table 1, the sole material prepared in this application has high tensile strength, and the tensile strength changes little after high-temperature treatment. At the same time, it has good flexural strength, resilience, UV radiation resistance and abrasion resistance. This indicates that the sole material has good structural stability, high mechanical strength, and resistance to high temperature and UV aging.

[0115] Combining Examples 1 and 4-10 with Table 1, it can be seen that no hydrophobic bamboo powder was added to the filler particles in Example 4. Compared with Example 1, the tensile strength of the shoe sole prepared in Example 4 is lower than that in Example 1, the difference between the tensile strength at room temperature and high temperature is greater than the corresponding difference in Example 1, and the wear resistance is worse than that in Example 1. This indicates that the addition of hydrophobic bamboo powder can not only improve the strength, but also facilitate heat dissipation of the shoe sole by utilizing its porous structure, thereby extending the service life of the shoe sole on high-temperature roads.

[0116] In Example 5, mullite powder replaced mullite microparticles in the filler particles, and zirconium dioxide powder replaced nano-zirconia in the same mass. In Example 6, ethyl cellulose solution replaced triethylenetetramine solution in the mullite microparticles, and ethyl cellulose solution replaced hydroxyethyl cellulose solution in the nano-zirconia. Compared to Example 1, the tensile strength of the shoe soles prepared in Examples 5 and 6 was lower than that in Example 1, the difference in tensile strength between room temperature and high temperature was greater than the corresponding difference in Example 1, the resilience was lower than that in Example 1, and the abrasion resistance was worse than that in Example 1. This indicates that the combination of mullite powder, triethylenetetramine solution, zirconium dioxide powder, hydroxyethyl cellulose solution, and ETPU foam particles utilizes the reaction between the amino groups on the surface of mullite powder and the hydroxyl groups on the surface of zirconium dioxide powder with the isocyanates in the ETPU foam particles to improve the bonding compatibility between the bonding layer and the foam layer, thereby improving the strength and abrasion resistance of the shoe sole, resulting in better structural stability and a longer service life.

[0117] In Example 7, no heat-resistant filler was added to the ETPU foam particles. In Example 8, the heat-resistant filler in the ETPU foam particles was silica. Compared with Example 1, the tensile strength of the shoe soles prepared in Examples 7 and 8 was lower than that in Example 1, and the difference in tensile strength between room temperature and high temperature was greater than the corresponding difference in Example 1. This indicates that the combination of barium stearate and silica, utilizing the heat resistance and aging resistance of barium stearate combined with the heat insulation filling effect of silica, further improves the heat resistance of the foam layer. In addition, barium stearate has a certain degree of lubricity, which facilitates the molding of the foam layer. At the same time, silica and the silane coupling agent KH-570 on the surface of hydrophobic bamboo powder are easily compatible and bonded, thereby further improving the strength and heat aging resistance of the shoe sole material.

[0118] In Example 9, the foaming agent in the ETPU foam particles was sodium bicarbonate. Compared with Example 1, the tensile strength of the sole prepared in Example 9 was lower than that in Example 1, and the difference in tensile strength between room temperature and high temperature was greater than the corresponding difference in Example 1. This indicates that the combination of sodium bicarbonate and polyethylene glycol utilizes the gas-generating effect of sodium bicarbonate when heated and the foaming effect of polyethylene glycol to further improve the foaming effect of the foam layer. Furthermore, the hydroxyl groups at both ends of polyethylene glycol not only improve the foaming effect but also enhance the bonding stability between the foam layer and the bonding layer, thereby increasing the service life of the sole.

[0119] In Example 10, no maleic anhydride-grafted EVA was added to the ETPU foam particles. Compared with Example 1, the tensile strength of the sole prepared in Example 10 was lower than that in Example 1, the difference in tensile strength between room temperature and high temperature was greater than the corresponding difference in Example 1, the flexural strength was worse than that in Example 1, and the resilience was lower than that in Example 1. This indicates that the maleic anhydride-grafted EVA, when combined with the EVA in the bonding layer, can further improve the adhesive compatibility of the finished sole, thereby giving the sole high strength while also providing good abrasion resistance and resistance to thermo-oxidative aging, extending the service life of the sole on high-temperature roads.

[0120] Based on Example 1 and Comparative Examples 1-2 and Table 1, it can be seen that no filler particles were added to the bonding layer of Comparative Example 1. Compared with Example 1, the tensile strength of the sole prepared in Comparative Example 1 is lower than that in Example 1, the difference between the tensile strength at room temperature and high temperature is greater than the corresponding difference in Example 1, and the wear resistance is worse than that in Example 1. This indicates that the addition of filler particles can not only increase the strength of the sole, but also improve its wear resistance.

[0121] In Comparative Example 2, no maleic anhydride-grafted POE was added to the bonding layer. Compared with the Example 1, the tensile strength of the sole prepared in Comparative Example 2 was lower than that in Example 1, the difference in tensile strength between room temperature and high temperature was greater than the corresponding difference in Example 1, the flexural strength was worse than that in Example 1, and the resilience was lower than that in Example 1. This indicates that the combination of maleic anhydride-grafted POE and maleic anhydride-grafted EVA can further improve the bonding compatibility of the bonding layer and the foam layer, thereby improving the structural stability of the sole material and giving the sole a longer service life.

[0122] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a shoe sole, characterized in that, Includes the following steps: S1. A bonding layer is bonded to the surface of the film to obtain a semi-finished product; S2. Place the semi-finished product into the foaming mold, inject ETPU foam particles into the mold, and after foaming, the ETPU foam particles form a foam layer to obtain the finished shoe sole. The bonding layer comprises the following raw materials in parts by weight: 40-60 parts EVA particles, 15-25 parts TPR particles, 10-25 parts maleic anhydride-grafted POE, 10-18 parts filler particles, and 1-2 parts antioxidant; the filler particles are composed of mullite microparticles, nano-zirconia, and hydrophobic bamboo powder in a mass ratio of 1:1-2:0.5-1; the mullite microparticles are composed of mullite powder and triethylenetetramine solution in a mass ratio of 1:0.1-0.25; the nano-zirconia is composed of zirconium dioxide powder and hydroxyethyl cellulose solution in a mass ratio of 1:0.1-0.3; and the hydrophobic bamboo powder is prepared by hydrophobic modification of bamboo powder with silane coupling agent KH-570.

2. The method for preparing a shoe sole according to claim 1, characterized in that, The ETPU foam particles contain the following raw materials in parts by weight: 30-50 parts polyester polyol, 20-40 parts polyether polyol, 25-45 parts isocyanate, 5-10 parts foaming agent, 2-6 parts chain extender, 0.5-1 part antioxidant, 2-8 parts heat-resistant filler, and 5-10 parts maleic anhydride-grafted EVA.

3. The method for preparing a shoe sole according to claim 2, characterized in that, The heat-resistant filler is composed of barium stearate and silicon dioxide in a mass ratio of 1:0.6-1.

5.

4. The method for preparing a shoe sole according to claim 2, characterized in that, The foaming agent is composed of sodium bicarbonate and polyethylene glycol in a mass ratio of 1:1-3.

5. The method for preparing a shoe sole according to claim 2, characterized in that, The antioxidant is composed of antioxidant 1010 and ultraviolet absorber UV-971 in a mass ratio of 1:1-3.

6. The method for preparing a shoe sole according to claim 2, characterized in that, The chain extender is 1,4-butanediol.

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