Recyclable, high-wear-resistance and high-slip-resistance TPU sole specially used for running shoes, and preparation method therefor

Abstract

The present invention particularly relates to a recyclable, high-wear-resistance and high-slip-resistance TPU sole specially used for running shoes and a preparation method therefor. The preparation method comprises: cutting a TPU film sheet, placing a TPU reinforcing thin sheet at the position of a shoe sole mold corresponding to the toe area, then placing the cut TPU film sheet under the shoe sole mold, performing compression molding on the TPU film sheet in the shoe sole mold by means of a high-frequency wave processing or hot pressing mode, and performing secondary cutting to remove offcut materials to obtain the TPU sole which is specially used for running shoes and which conforms to the shape of the shoe sole mold. The TPU film sheet is prepared from raw materials comprising polytetramethylene ether glycol, isophorone diisocyanate, a chain extender, a cross-linking agent, an anti-slip agent, etc., and has good mechanical strength and wear resistance and exhibits excellent attachment performance and stability with surfaces of external objects, so as to endow the TPU shoe sole with good wear resistance, slip resistance and yellowing resistance and quick-processing performance with simple shape moldability.

Description

A recyclable, highly wear-resistant, and highly anti-skid TPU sole specifically designed for running shoes and its preparation method Technical Field

[0001] The present invention relates to the technical field of soles, and in particular to a recyclable, highly wear-resistant, and highly anti-skid TPU sole specially designed for running shoes and a preparation method thereof. Background Art

[0002] Running shoes are essential footwear for protecting the feet during running and other sports. The sole is the part of the shoe that comes into direct contact with the ground. A high-quality running shoe sole should possess both wear resistance and anti-slip properties. Anti-slip performance directly impacts the wearer's comfort and safety, affecting speed and performance in competitive sports. Wear resistance, on the other hand, determines the shoe's lifespan. Therefore, these two performance indicators are of particular concern to both footwear companies and consumers.

[0003] Thermoplastic polyurethane elastomer, abbreviated as TPU, is a linear block copolymer composed of oligomer polyol as soft segment and diisocyanate as hard segment. According to the soft segment structure, it can be further divided into polyester type, polyether type and butadiene type. Among them, the advantages of polyether type TPU are good flexibility, high hydrolysis resistance and resilience, but poor strength, thermal stability and chemical stability; while the advantages of polyester type TPU are high tensile strength, wear resistance and high temperature resistance, but poor hydrolysis resistance. The above TPU material is used in the production of shoe outsoles, which has good bending resistance, wear resistance and oxidation resistance, but poor anti-slip property, temperature resistance and yellowing resistance. The poor anti-slip property of the outsole will affect the wearer's walking safety, especially on smooth or wet roads. For this reason, the development of TPU materials with high anti-slip and high wear resistance has broad application prospects and commercial value for its application in shoe materials. Summary of the Invention

[0004] The purpose of the present invention is to provide a recyclable, highly wear-resistant and highly anti-skid TPU sole for running shoes in order to solve the above-mentioned deficiencies in the prior art.

[0005] The purpose of the present invention is achieved by the following technical solution: a recyclable, highly wear-resistant, and highly anti-slip TPU sole for running shoes, comprising the following preparation steps:

[0006] (1) Cut the TPU film into the set size and set aside;

[0007] (2) Place a TPU reinforcement sheet at the position of the sole mold corresponding to the toe, and then place the cut TPU membrane under the sole mold;

[0008] (3) The TPU membrane under the sole mold is thermoformed by high-frequency processing or hot pressing, and then cooled to set the shape. Then, a secondary cutting is performed to remove the edge material to obtain a TPU sole for running shoes that matches the shape of the sole mold.

[0009] Furthermore, the thickness of the TPU reinforcement sheet is 0.7-2 mm. By padding the toe with the TPU reinforcement sheet, the thickness and hardness of the toe can be increased, thereby improving the anti-friction and collision strength of the toe.

[0010] Furthermore, in step (1), the preparation steps of the TPU diaphragm are specifically as follows: heating polytetramethylene ether glycol to 120°C for dehydration for 1-2 hours, filling with nitrogen, lowering the temperature to 80-90°C, adding isophorone diisocyanate and a catalyst thereto, stirring and reacting for 1.5-3 hours to obtain a prepolymer, lowering the temperature to 30°C, adding a solvent and a chain extender to the prepolymer and continuing the reaction for 2-3 hours, then adding a cross-linking agent, an anti-slip agent and a stabilizing agent, heating and mixing, and then extruding and molding through an extruder to obtain the TPU diaphragm.

[0011] Furthermore, in the step of preparing the TPU film, the NCO group content in the reaction system is 8-12% of the mass of the prepolymer, the chain extension coefficient is 1.02-1.05, and the hard segment content is 16-20%.

[0012] Furthermore, the chain extender is one or more combinations of alicyclic diamine compounds or 3,5-diamino-1,2,4-triazole.

[0013] Furthermore, the catalyst is an organic tin catalyst, preferably dibutyltin dilaurate, and the amount of the catalyst is 0.04-0.08% of the mass of the prepolymer.

[0014] Furthermore, the solvent is toluene, ethyl acetate or tetrahydrofuran, and the amount of the solvent is 58-65% of the total mass of the raw materials; the cross-linking agent is triethanolamine, and the amount of the cross-linking agent is 1.2-2% of the mass of the prepolymer.

[0015] Furthermore, the anti-slip agent is at least one of an organosilicon compound, nano-silicon dioxide, nano-zinc oxide, or nano-aluminum oxide, and the amount of the anti-slip agent is 5-10% of the mass of the prepolymer. As a preferred embodiment of the present invention, the anti-slip agent is a mixture of an organosilicon compound and nano-zinc oxide in a mass ratio of 3:2.

[0016] In the present invention, the TPU film is obtained by reacting polytetramethylene ether glycol and isophorone diisocyanate to obtain a prepolymer, and then a cross-linked network is formed under the action of a specific chain extender and triethanolamine, which significantly improves the mechanical properties and elasticity of the TPU film. Among them, the TPU synthesized with polytetramethylene ether glycol as the soft segment and isophorone diisocyanate as the hard segment has good yellowing resistance and good flexibility and mechanical properties. The addition of the chain extender containing secondary amine molecules or amino groups helps to form intermolecular hydrogen bonds, thereby improving the mechanical properties and low-temperature resistance of the TPU; the addition of a cross-linking agent moderately increases the degree of cross-linking of the TPU system, so that the TPU film maintains good toughness and elongation while ensuring that it has moderate hardness and improves the high temperature resistance and chemical stability of the TPU film; the addition of an anti-slip agent improves the anti-slip performance and wear resistance of the TPU film.

[0017] Furthermore, the organosilicon compound includes the following raw materials in parts by weight: 70-100 parts of hydroxyl-terminated polydimethylsiloxane, 20-40 parts of toluene diisocyanate, 0.5-1.5 parts of catalyst aid, 0.8-1.5 parts of foaming aid, 8-20 parts of fumed silica, 3-8 parts of foam stabilizer and 1-2 parts of water.

[0018] Furthermore, the preparation steps of the organosilicon compound are specifically as follows: hydroxyl-terminated polydimethylsiloxane, a catalyst, fumed silica, a foam stabilizer and a foaming aid are added to a stirred reactor and mixed thoroughly, toluene diisocyanate is added thereto and stirred for reaction, water is added and stirred, and the mixture is allowed to stand for foaming, and the organosilicon compound is obtained after aging.

[0019] The catalytic aid is an organic tin catalyst, preferably stannous octoate or dibutyltin dilaurate; the foaming aid is a mixture of triethylenediamine and dipropylene glycol water in a mass percentage of 30-40%:60-70%.

[0020] The organosilicon compound obtained by the above preparation steps has a uniform pore structure, and at the same time has high thermal stability, mechanical strength and hydrophobicity; using it in the preparation of TPU diaphragms can effectively enhance the wear resistance, anti-slip properties and temperature stability of the TPU diaphragms.

[0021] Furthermore, the stabilizing agent is a combination of one or more of a coupling agent, an antioxidant, a plasticizer, and a light stabilizer. The selection of the stabilizing agent can be reasonably added according to the final performance requirements of the TPU film, and the amount of the stabilizing agent is 0.5-2% of the mass of the prepolymer.

[0022] Furthermore, in step (3), the sole mold is placed on a heating platform of a high-frequency machine, and the TPU membrane is thermally molded by the high-frequency current of the high-frequency machine; wherein the high-frequency current of the high-frequency machine is 8-10A, the frequency is 6000-8000HZ, the power-on time is 30-60S, and the temperature is 140-160°C. The sole mold is then placed on a cooling platform at a temperature of 10-20°C to cool the molded TPU membrane, and then the molded TPU membrane is cooled and shaped by cold pressing of the mold, and finally the TPU sole is obtained by secondary cutting to remove the excess material.

[0023] Furthermore, in step (3), the sole mold is placed on a heating bracket with a temperature of 130-160°C, the TPU film is pressurized by a hot pressing mold to die-cast the TPU membrane, and then the TPU membrane is cooled and shaped by cold pressing of the mold, and finally the residual material is removed by secondary cutting to obtain the TPU sole.

[0024] The beneficial effects of the present invention are as follows: the present invention provides a method for preparing a recyclable, highly wear-resistant, and highly anti-slip TPU sole specifically for running shoes. The preparation method has a short processing flow, simple operation, and high production efficiency. Specifically, by inserting a TPU reinforcing sheet into the toe position within the sole mold, the thickness and hardness of the toe can be enhanced, imparting the toe with anti-friction and anti-collision properties. The outsole is thermoformed using a TPU membrane. The TPU membrane is obtained by reacting polytetramethylene ether glycol and isophorone diisocyanate to obtain a prepolymer, and then forms a cross-linked network under the action of a specific chain extender and triethanolamine, significantly improving the mechanical properties and elasticity of the TPU membrane. At the same time, the addition of an anti-slip agent enhances the wear resistance and anti-slip properties of the TPU membrane. DETAILED DESCRIPTION

[0025] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the embodiments. The contents mentioned in the embodiments are not intended to limit the present invention.

[0026] Example 1

[0027] This embodiment provides a recyclable, highly wear-resistant, and highly anti-slip TPU sole for running shoes, including the following preparation steps:

[0028] (1) Cut the TPU film into the set size and set aside;

[0029] (2) Place a TPU reinforcement sheet at the position of the sole mold corresponding to the toe, and then place the cut TPU membrane under the sole mold;

[0030] (3) The TPU membrane under the sole mold is thermoformed by high-frequency processing, and then cooled to set the shape. Then, secondary cutting is performed to remove the edge material to obtain a TPU sole for running shoes that matches the shape of the sole mold.

[0031] Furthermore, the thickness of the TPU reinforcement sheet is 0.7 mm.

[0032] Furthermore, in step (1), the preparation steps of the TPU diaphragm are specifically as follows: heating polytetramethylene ether glycol to 120° C. for dehydration for 1 hour, filling with nitrogen, lowering the temperature to 80° C., adding isophorone diisocyanate and a catalyst thereto, stirring and reacting for 1.5 hours to obtain a prepolymer, lowering the temperature to 30° C., adding a solvent and a chain extender to the prepolymer and continuing the reaction for 2 hours, then adding a cross-linking agent and an anti-slip agent for mixing, and then extruding and molding through an extruder to obtain the TPU diaphragm.

[0033] Furthermore, in the step of preparing the TPU diaphragm, the NCO group content in the reaction system is 8% of the mass of the prepolymer, the chain extension coefficient is 1.02, and the hard segment content is 16%.

[0034] Furthermore, the chain extender is a binary cyclic secondary amine piperazine chain extender.

[0035] Furthermore, the catalyst is dibutyltin dilaurate, and the amount of the catalyst is 0.05% of the mass of the prepolymer.

[0036] Furthermore, the solvent is toluene, and the amount of the solvent is 58% of the total mass of the raw materials; the cross-linking agent is triethanolamine, and the amount of the cross-linking agent is 1.2% of the mass of the prepolymer.

[0037] Furthermore, the anti-slip agent is nano zinc oxide, and the amount of the anti-slip agent is 6% of the mass of the prepolymer.

[0038] Furthermore, in step (3), the sole mold is placed on a heating platform of a high-frequency machine, and the TPU membrane is thermally molded by the high-frequency current of the high-frequency machine; wherein the high-frequency current of the high-frequency machine is 8A, the frequency is 6000HZ, the power-on time is 40S, and the temperature is 140°C. The sole mold is then placed on a cooling platform at a temperature of 20°C to cool the molded TPU membrane, and then the molded TPU membrane is cooled and shaped by cold pressing of the mold, and finally the TPU sole is obtained by secondary cutting to remove the excess material.

[0039] Example 2

[0040] This embodiment provides a recyclable, highly wear-resistant, and highly anti-slip TPU sole for running shoes, including the following preparation steps:

[0041] (1) Cut the TPU film into the set size and set aside;

[0042] (2) Place a TPU reinforcement sheet at the position of the sole mold corresponding to the toe, and then place the cut TPU membrane under the sole mold;

[0043] (3) The TPU membrane under the sole mold is thermoformed by hot pressing, cooled and shaped, and then cut twice to remove the edge material to obtain a TPU sole for running shoes that matches the shape of the sole mold.

[0044] Furthermore, the thickness of the TPU reinforcement sheet is 2 mm.

[0045] Furthermore, in step (1), the preparation steps of the TPU diaphragm are specifically as follows: heating polytetramethylene ether glycol to 120° C. and dehydrating for 2 hours, filling with nitrogen, lowering the temperature to 90° C., adding isophorone diisocyanate and a catalyst thereto and stirring and reacting for 3 hours to obtain a prepolymer, lowering the temperature to 30° C., adding a solvent and a chain extender to the prepolymer and continuing the reaction for 3 hours, then adding a cross-linking agent and an anti-slip agent and mixing, and then extruding and molding through an extruder to obtain the TPU diaphragm.

[0046] Furthermore, in the step of preparing the TPU diaphragm, the NCO group content in the reaction system is 10% of the mass of the prepolymer, the chain extension coefficient is 1.04, and the hard segment content is 18%.

[0047] Furthermore, the chain extender is 3,5-diamino-1,2,4-triazole.

[0048] Furthermore, the catalyst is dibutyltin dilaurate, and the amount of the catalyst is 0.06% of the mass of the prepolymer.

[0049] Furthermore, the solvent is toluene, and the amount of the solvent is 65% of the total mass of the raw materials; the cross-linking agent is triethanolamine, and the amount of the cross-linking agent is 2% of the mass of the prepolymer.

[0050] Furthermore, the anti-slip agent is a mixture of nano zinc oxide and nano silicon dioxide in a mass ratio of 3:2, and the amount of the anti-slip agent is 10% of the mass of the prepolymer.

[0051] Furthermore, in step (3), the sole mold is placed on a heating bracket at a temperature of 150°C, the TPU film is pressurized by a hot pressing mold to die-cast the TPU membrane, and then the TPU membrane is cooled and shaped by cold pressing of the mold. Finally, the TPU sole is obtained by removing the excess material through secondary cutting.

[0052] Example 3

[0053] This embodiment provides a recyclable, highly wear-resistant, and highly anti-slip TPU sole for running shoes, including the following preparation steps:

[0054] (1) Cut the TPU film into the set size and set aside;

[0055] (2) Place a TPU reinforcement sheet at the position of the sole mold corresponding to the toe, and then place the cut TPU membrane under the sole mold;

[0056] (3) The TPU membrane under the sole mold is thermoformed by hot pressing, cooled and shaped, and then cut twice to remove the edge material to obtain a TPU sole for running shoes that matches the shape of the sole mold.

[0057] Furthermore, the thickness of the TPU reinforcement sheet is 1 mm.

[0058] Furthermore, in step (1), the preparation steps of the TPU diaphragm are specifically as follows: heating polytetramethylene ether glycol to 120° C. for dehydration for 2 hours, filling with nitrogen, lowering the temperature to 90° C., adding isophorone diisocyanate and a catalyst thereto, stirring and reacting for 2 hours to obtain a prepolymer, lowering the temperature to 30° C., adding a solvent and a chain extender to the prepolymer and continuing the reaction for 2 hours, then adding a cross-linking agent and an anti-slip agent for mixing, and then extruding and molding through an extruder to obtain the TPU diaphragm.

[0059] Furthermore, in the step of preparing the TPU diaphragm, the NCO group content in the reaction system is 10% of the mass of the prepolymer, the chain extension coefficient is 1.05, and the hard segment content is 20%.

[0060] Furthermore, the chain extender is 3,5-diamino-1,2,4-triazole.

[0061] Furthermore, the catalyst is dibutyltin dilaurate, and the amount of the catalyst is 0.08% of the mass of the prepolymer.

[0062] Furthermore, the solvent is toluene, and the amount of the solvent is 60% of the total mass of the raw materials; the cross-linking agent is triethanolamine, and the amount of the cross-linking agent is 1.6% of the mass of the prepolymer.

[0063] Furthermore, the anti-slip agent is an organic silicon compound, and the amount of the anti-slip agent is 8% of the mass of the prepolymer.

[0064] In this embodiment, the organosilicon compound includes the following raw materials in parts by weight: 70 parts of hydroxyl-terminated polydimethylsiloxane, 20 parts of toluene diisocyanate, 0.5 parts of catalyst, 1 part of foaming agent, 10 parts of fumed silica, 4 parts of foam stabilizer and 1 part of water.

[0065] Furthermore, the preparation steps of the organosilicon compound are specifically as follows: hydroxyl-terminated polydimethylsiloxane, a catalyst, fumed silica, a foam stabilizer and a foaming aid are added to a stirred reactor and mixed thoroughly, toluene diisocyanate is added thereto and stirred for reaction, water is added and stirred, and the mixture is allowed to stand for foaming, and the organosilicon compound is obtained after aging.

[0066] Furthermore, the catalyst aid is stannous octoate; the molecular weight of the hydroxyl-terminated polydimethylsiloxane is 1000; the foaming aid is a mixture of triethylenediamine and dipropylene glycol water in a mass percentage of 35%:65%; and the foam stabilizer is silicone oil L-580.

[0067] Furthermore, in step (3), the sole mold is placed on a heating bracket at a temperature of 160°C, the TPU film is pressurized by a hot pressing mold to die-cast the TPU membrane, and then the TPU membrane is cooled and shaped by cold pressing of the mold. Finally, the TPU sole is obtained by removing the excess material through secondary cutting.

[0068] Example 4

[0069] This embodiment provides a recyclable, highly wear-resistant, and highly anti-slip TPU sole for running shoes, including the following preparation steps:

[0070] (1) Cut the TPU film into the set size and set aside;

[0071] (2) Place a TPU reinforcement sheet at the position of the sole mold corresponding to the toe, and then place the cut TPU membrane under the sole mold;

[0072] (3) The TPU membrane under the sole mold is thermoformed by high-frequency processing, and then cooled to set the shape. Then, secondary cutting is performed to remove the edge material to obtain a TPU sole for running shoes that matches the shape of the sole mold.

[0073] Furthermore, the thickness of the TPU reinforcement sheet is 1 mm.

[0074] Furthermore, in step (1), the preparation steps of the TPU diaphragm are specifically as follows: heating polytetramethylene ether glycol to 120° C. and dehydrating for 2 hours, filling with nitrogen, lowering the temperature to 90° C., adding isophorone diisocyanate and a catalyst thereto and stirring and reacting for 2 hours to obtain a prepolymer, lowering the temperature to 30° C., adding a solvent and a chain extender to the prepolymer and continuing the reaction for 3 hours, then adding a cross-linking agent, an anti-slip agent and a stabilizing agent, heating and mixing, and then extruding and molding through an extruder to obtain the TPU diaphragm.

[0075] Furthermore, in the step of preparing the TPU diaphragm, the NCO group content in the reaction system is 10% of the mass of the prepolymer, the chain extension coefficient is 1.02, and the hard segment content is 18%.

[0076] Furthermore, the chain extender is 3,5-diamino-1,2,4-triazole.

[0077] Furthermore, the catalyst is dibutyltin dilaurate, and the amount of the catalyst is 0.04-0.08% of the mass of the prepolymer.

[0078] Furthermore, the solvent is toluene, and the amount of the solvent is 60% of the total mass of the raw materials; the cross-linking agent is triethanolamine, and the amount of the cross-linking agent is 1.5% of the mass of the prepolymer.

[0079] Furthermore, the anti-slip agent is formed by mixing an organic silicon compound and nano zinc oxide in a mass ratio of 3:2, and the amount of the anti-slip agent is 8% of the mass of the prepolymer.

[0080] In this embodiment, the organosilicon compound includes the following raw materials in parts by weight: 80 parts of hydroxyl-terminated polydimethylsiloxane, 28 parts of toluene diisocyanate, 1 part of catalyst, 1 part of foaming agent, 12 parts of fumed silica, 5 parts of foam stabilizer and 1.5 parts of water.

[0081] Furthermore, the preparation steps of the organosilicon compound are specifically as follows: hydroxyl-terminated polydimethylsiloxane, a catalyst, fumed silica, a foam stabilizer and a foaming aid are added to a stirred reactor and mixed thoroughly, toluene diisocyanate is added thereto and stirred for reaction, water is added and stirred, and the mixture is allowed to stand for foaming, and the organosilicon compound is obtained after aging.

[0082] Among them, the catalytic auxiliary agent is an organic tin catalyst, preferably stannous octoate or dibutyltin dilaurate; the foaming auxiliary agent is a mixture of triethylenediamine and dipropylene glycol water in a mass percentage of 35%:65%; the foam stabilizer is silicone oil L-580.

[0083] Furthermore, the stabilizing agent is antioxidant 5057, and the amount of the stabilizing agent is 0.8% of the mass of the prepolymer.

[0084] Furthermore, in step (3), the sole mold is placed on a heating platform of a high-frequency machine, and the TPU membrane is thermally molded by the high-frequency current of the high-frequency machine; wherein the high-frequency current of the high-frequency machine is 10A, the frequency is 8000HZ, the power-on time is 40S, and the temperature is 160°C. The sole mold is then placed on a cooling platform at a temperature of 20°C to cool the molded TPU membrane, and then the molded TPU membrane is cooled and shaped by cold pressing of the mold, and finally the TPU sole is obtained by secondary cutting to remove the excess material.

[0085] Comparative Example 1

[0086] The difference between this comparative example and Example 4 is that this comparative example uses 1,4-butanediol as a chain extender.

[0087] Comparative Example 2

[0088] The difference between this comparative example and Example 4 is that no cross-linking agent is added in this comparative example.

[0089] Comparative Example 3

[0090] The difference between this comparative example and Example 4 is that this comparative example uses commercially available white carbon black A200 purchased from Kaiyin Chemical as an anti-slip agent.

[0091] Comparative Example 4

[0092] The difference between this comparative example and Example 4 is that no anti-slip agent is added in this comparative example.

[0093] The TPU soles prepared in Examples 1-4 and Comparative Examples 1-4 were selectively tested for hardness, anti-slip performance, wear resistance, and yellowing resistance as required, wherein the hardness was measured using the Shore A hardness in the ASTM D2240 standard, the elongation at break was measured using the ASTM D412 standard, the wear resistance was measured using the DIN 5351 standard, and the anti-slip performance was measured using the SATRATM 144 standard; the yellowing resistance was measured using the B method in the HG-T 3689-2014 standard. The test results of Examples 1-4 and Comparative Examples 1-4 are shown in Table 1 below.

[0094] Table 1 Performance test data of Examples 1-4 and Comparative Examples 1-4

[0095] From the comparison of the above data tables, it can be seen that the hardness of the TPU soles prepared by Examples 1-4 is above 62A, the elongation at break is greater than 725%, and the DIN abrasion is greater than 24mm. 3, indicating that the TPU soles have excellent mechanical properties and wear resistance. In terms of anti-slip performance, the dry anti-slip coefficients of the TPU soles prepared in Examples 1-4 are all greater than 0.5, and the wet anti-slip coefficients are all greater than 0.7, indicating that the TPU soles have good anti-slip performance. At the same time, the UV yellowing rating of the TPU soles is all 4, indicating good yellowing resistance. On the one hand, a comparison between Example 4 and Comparative Examples 3-4 shows that Example 4 uses an organosilicon compound and nano-zinc oxide as anti-slip agents, significantly improving the anti-slip performance of the TPU sole, with the improvement in the wet anti-slip coefficient being particularly significant. In addition, the DIN abrasion resistance is also much higher than that of Comparative Examples 3-4, indicating that the organosilicon compound and nano-zinc oxide help improve the wear resistance of the TPU sole. Therefore, the present invention plays an important role in improving the anti-slip and wear resistance of the TPU sole through the combined action of the organosilicon compound and nano-zinc oxide. On the other hand, by comparing Example 4 with Comparative Example 1, it can be seen that the present invention, by introducing a chain extender containing an amino group in Example 4, helps to form intermolecular hydrogen bonds, thereby obtaining higher mechanical properties; compared with Comparative Example 2, Example 4 controls the degree of cross-linking by adding a cross-linking agent, thereby appropriately improving the hardness of the TPU sole.

[0096] The above specific embodiments are further explanations of the technical solutions and beneficial effects of the present invention, and are not intended to limit the implementation methods. For those skilled in the art, any obvious substitutions that do not depart from the concept of the present invention are within the scope of protection of the present invention.

Claims

1. A method for preparing a recyclable, highly wear-resistant, and highly anti-skid TPU sole for running shoes, characterized by: The method comprises the following preparation steps: (1) Cut the TPU film into the set size and set aside; (2) Place a TPU reinforcement sheet at the position of the sole mold corresponding to the toe, and then place the cut TPU membrane under the sole mold; (3) The TPU membrane under the sole mold is thermoformed by high-frequency processing or hot pressing, and then cooled to set the shape. Then, a secondary cutting is performed to remove the edge material to obtain a TPU sole for running shoes that matches the shape of the sole mold.

2. The method for preparing a recyclable, highly wear-resistant, and highly anti-skid TPU sole for running shoes according to claim 1, characterized in that: The thickness of the TPU reinforcement sheet is 0.7-2 mm.

3. The method for preparing a recyclable, highly wear-resistant, and highly anti-skid TPU sole for running shoes according to claim 1, characterized in that: In step (1), the preparation steps of the TPU diaphragm are specifically as follows: heating polytetramethylene ether glycol to 120°C for dehydration for 1-2 hours, filling with nitrogen, lowering the temperature to 80-90°C, adding isophorone diisocyanate and a catalyst thereto, stirring and reacting for 1.5-3 hours to obtain a prepolymer, lowering the temperature to 30°C, adding a solvent and a chain extender to the prepolymer and continuing the reaction for 2-3 hours, then adding a cross-linking agent, an anti-slip agent and a stabilizing agent, heating and mixing, and then extruding through an extruder to obtain the TPU diaphragm.

4. The method for preparing a recyclable, highly wear-resistant, and highly anti-skid TPU sole for running shoes according to claim 3, characterized in that: In the preparation step of the TPU film, the NCO group content in the reaction system is 8-12% of the mass of the prepolymer, and the chain extension coefficient is 1.02-1.

05.

5. The method for preparing a recyclable, highly wear-resistant, and highly anti-skid TPU sole for running shoes according to claim 3, characterized in that: The chain extender is a combination of one or more of an alicyclic diamine compound and 3,5-diamino-1,2,4-triazole.

6. The method for preparing a recyclable, highly wear-resistant, and highly anti-skid TPU sole for running shoes according to claim 3, characterized in that: The anti-slip agent is at least one of organic silicon compounds, nano silicon dioxide, nano zinc oxide or nano aluminum oxide, and the amount of the anti-slip agent is 5-10% of the mass of the prepolymer.

7. The method for preparing a recyclable, highly wear-resistant, and highly anti-skid TPU sole for running shoes according to claim 3, characterized in that: The stabilizing agent is one or more combinations of coupling agents, antioxidants, plasticizers and light stabilizers.

8. The method for preparing a recyclable, highly wear-resistant, and highly anti-skid TPU sole for running shoes according to claim 1, characterized in that: In step (3), the sole mold is placed on the heating platform of the high-frequency machine, and the TPU membrane is thermoformed by the high-frequency machine. Then, the TPU sole is obtained by cooling and shaping, and cutting the TPU membrane a second time to remove the excess material.

9. The method for preparing a recyclable, highly wear-resistant, and highly anti-skid TPU sole for running shoes according to claim 1, characterized in that: In step (3), the sole mold is placed on a heating bracket at a temperature of 130-160°C, and the TPU film is pressurized by a hot pressing mold to die-cast the TPU film. The TPU film is then cooled and shaped, and the excess material is removed by secondary cutting to obtain the TPU sole.

10. A recyclable, highly wear-resistant, and highly anti-slip TPU sole for running shoes, characterized by: The method is prepared according to any one of claims 1 to 9.

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