Sole material and preparation method thereof

Abstract

The invention relates to the technical field of shoe soles, and provides a shoe sole material and a preparation method thereof.The shoe sole material is prepared from, by weight, 40-60 parts of EVA, 5-10 parts of shrinkage stopping agent, 5-10 parts of EPDM, 10-20 parts of polyolefin elastomer, 10-25 parts of SEBS, 10-15 parts of wear-resisting agent, 2-5 parts of talcum powder, 0.3-0.8 part of stearic acid, 1-1.5 parts of zinc oxide powder, 0.3-0.8 part of fast material, 0.3-0.8 part of environment-friendly tackifier, 0.6-1 part of bridging agent and 3.5-4.5 parts of medium-temperature foaming agent. Through formula adjustment and the preparation method, the balance of wear resistance, rebound resilience and lightness of the sole material is realized, and the prepared sole material has good lightness, wear resistance and buffering and damping properties, and is beneficial to improving the exercise performance of a user.

Description

Technical Field

[0001] The invention relates to the technical field of soles, and in particular to a sole material and a preparation method thereof. Background Art

[0002] Shoes are tools used to protect the feet. They can also be designed according to different sports attributes to help users improve their sports performance. The midsole is one of the core components of the shoe and plays a key role in the performance of the shoe.

[0003] In the prior art, EVA (full name in Chinese: ethylene-vinyl acetate copolymer) soles are one of the common types of shoe midsoles. A layer of rubber skin is usually attached to the outside of the EVA midsole to improve the wear resistance and anti-slip performance of the sole. The wear resistance of conventional EVA sole materials is poorer than that of rubber materials, so traditional EVA soles are easily scratched and torn, and have a short service life; and the weight of rubber materials is higher than that of EVA materials, so the soles made of rubber materials put a greater burden on the feet, and the feet are easily tired during long-term exercise. It is difficult for both to take into account the characteristics of lightness and wear resistance, which is not conducive to improving the user's sports performance. In addition, the rebound and shock absorption properties of existing shoe midsoles need to be further improved. Summary of the invention

[0004] The purpose of the present invention is to provide a sole material, aiming to improve the problem that the wear resistance, resilience and lightness of existing shoe midsoles are poor and difficult to take into account, which is not conducive to improving sports performance.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A shoe sole material, comprising, by weight:

[0007] EVA 40-60 parts, shrinkage stop agent 5-10 parts, EPDM 5-10 parts, polyolefin elastomer 10-20 parts, SEBS 10-25 parts, wear agent 10-15 parts, talc 2-5 parts, stearic acid 0.3-0.8 parts, zinc oxide powder 1-1.5 parts, quick-acting material 0.3-0.8 parts, environmentally friendly tackifier 0.3-0.8 parts, bridging agent 0.6-1 parts, medium-temperature foaming agent 3.5-4.5 parts.

[0008] Preferably, a sole material comprises, by weight: 45 parts of EVA, 10 parts of shrinkage stopper, 10 parts of EPDM, 15 parts of polyolefin elastomer, 20 parts of SEBS, 12 parts of wear-resistant agent, 3 parts of talc, 0.5 parts of stearic acid, 1.2 parts of zinc oxide powder, 0.5 parts of quick-acting material, 0.5 parts of environmentally friendly tackifier, 0.8 parts of bridging agent, and 4 parts of medium-temperature foaming agent.

[0009] Preferably, the content of vinyl acetate in the EVA is 18-26%.

[0010] A method for preparing the above-mentioned sole material is also provided, comprising the following steps:

[0011] (1) primary mixing: EVA, shrinkage stop agent, EPDM, polyolefin elastomer, SEBS, wear resistance agent, talcum powder, stearic acid, zinc oxide powder, quick-release material, environmentally friendly tackifier, bridging agent and medium-temperature foaming agent are put into a rinsing machine for mixing to obtain a primary mixed material;

[0012] (2) Secondary mixing: the primary mixed material is put into an open mixer for cooling, dispersion and mixing to obtain a secondary mixed material;

[0013] (3) Extrusion granulation: The secondary kneaded product is put into a granulator for extrusion granulation to obtain pellets;

[0014] (4) Injection molding: After the pellets are naturally cooled to room temperature, the pellets are matched with the mold and subjected to one-time injection molding on an injection molding machine to obtain a rough blank;

[0015] (5) Molding: The rough blank is cooled and shrunk naturally. After the surface temperature of the rough blank drops to room temperature, it is sorted and packaged and continues to be parked at room temperature. After the shrinkage of the rough blank is stable, it is molded to obtain a finished midsole.

[0016] Preferably, in step (1), the mixing time of the mixer is 11.5 to 12.5 minutes and the temperature is 113 to 123°C.

[0017] Preferably, in step (2), the time for secondary mixing in the open mixer is 5.5 to 6.5 minutes, and the temperature is 80 to 90°C.

[0018] Preferably, in step (2), the cooling and dispersion kneading is repeated 3 to 5 times on the first kneaded product.

[0019] Preferably, in step (4), the temperature of the primary injection molding machine for injection molding is 175° C. and the time is 500 s.

[0020] Preferably, in step (5), the rough blank is arranged and packaged and then left at room temperature for 12 hours.

[0021] Preferably, in step (5), the molding temperature is 170-180° C., the heating time is 450-510 s, and the cooling time is 450-510 s.

[0022] After adopting the above technical solution, the present invention has the following advantages compared with the background technology:

[0023] 1. The present invention achieves a balance among the wear resistance, resilience and lightness of the sole material through formula adjustment and preparation method. The prepared sole material has good lightness, wear resistance and cushioning and shock absorption, which helps to improve the sports performance of users.

[0024] 2. The present invention adds polyolefin elastomer to keep the sole material at a low specific gravity, thereby achieving the purpose of lightweighting.

[0025] 3. When preparing the sole material of the present invention, after the raw materials are mixed once in a mill, they are continuously transferred to an open mixer for repeated cooling, dispersion and mixing, which effectively improves the uniformity of mixing and provides sufficient cooling time, thereby avoiding the situation where a sudden drop in temperature destroys the material structure or the temperature is too high to cause direct granulation and harden the material, and effectively improves the quality of the finished sole material. DETAILED DESCRIPTION

[0026] For ease of understanding of the present invention, the present invention will be described more fully below. Although the present application provides preferred embodiments of the present invention, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Where specific techniques or conditions are not indicated in the embodiments, the technical conditions described in the documents in this area or the product specifications are carried out.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0028] In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0029] In the present invention, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0030] Only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and likewise any upper limit can be combined with any other upper limit to form an unspecified range. In addition, each separately disclosed point or single value can itself be combined as a lower limit or upper limit with any other point or single value or with other lower limits or upper limits to form an unspecified range.

[0031] The temperature parameters in the present invention, if not specifically limited, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the precision range controlled by the instrument.

[0032] In the description of the invention, “plurality” means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] If there is no special description, all embodiments and optional embodiments of the present invention can be combined with each other to form a new technical solution. If there is no special description, all technical features and optional technical features of the present invention can be combined with each other to form a new technical solution.

[0034] If not specifically stated, all steps of the present invention may be performed sequentially or randomly, but are preferably performed sequentially.

[0035] The reagents and instruments used without indicating the manufacturer are all conventional products obtained from the market.

[0036] In Examples 1 to 4 of the present invention, the specific raw materials used are shown in Table 1, but are not limited thereto:

[0037] Table 1 Raw material selection of the present invention

[0038]

[0039]

[0040] Among them, the performance of EVA with different VA (Chinese full name: vinyl acetate) contents is different. The present invention selects VA content of 18-26% in EVA raw materials, which has good softness and elasticity, and improves wear resistance and good stress cracking resistance. While providing basic physical property guarantees for sole materials, it can also reduce production costs. Shrinkage stoppers can improve the cold and hot dimensional stability of sole materials during the production process. Under different temperature conditions, they play a role in ensuring rebound and balancing shrinkage, reducing or eliminating the generation of dents, thereby improving the overall quality. EPDM (Chinese full name: ethylene propylene diene monomer rubber) can improve the wear resistance, elongation and aging resistance of sole materials. The flexibility and resilience of polyolefin elastomers are much higher than those of EVA raw materials, and after foaming, they have lighter weight, better compression resilience, high tear strength and other effects, and can reduce the formula density, so that the foam cells of the sole materials prepared are uniform and delicate, and have a good touch. SEBS (Chinese full name: hydrogenated styrene-butadiene block copolymer) can improve wear resistance and compression resilience. Wear-resistant agents can further improve wear resistance. Talc is used as a filler to ensure the structural stability of the sole material. Stearic acid can improve the wear resistance and durability of the sole material, as well as improve the flexibility and comfort of the sole material, and help to evenly disperse the various raw material components to ensure the overall quality. Zinc oxide powder and quick-release materials can both play a role in reducing the decomposition temperature of the medium-temperature foaming agent. By reducing the decomposition temperature, the medium-temperature foaming agent can be triggered to decompose at a lower temperature, thereby generating gas faster and improving the foaming efficiency; the lower decomposition temperature also helps to better control the decomposition timing of the medium-temperature foaming agent during the production process, making the foaming process more controllable; and can affect the gas release rate during the foaming process, thereby optimizing the internal structure and performance of the sole material. Environmentally friendly thickeners can increase the cross-linking of the foaming, thereby enhancing the wear resistance of the sole material. Bridging agents can enable the molecular chains of the material to form a stable network structure, thereby enhancing the material properties and improving the wear resistance, weather resistance and chemical corrosion resistance of the sole material. The medium-temperature foaming agent can completely decompose in a short period of time to produce bubbles, which plays a foaming role, helping to improve the elongation and pore structure of the sole material, and give the sole material better physical properties, such as density, tensile strength, tear strength, etc. It can also control the foaming conditions to form bubbles of a certain size inside the foaming material, thereby improving the shock-absorbing performance of the sole material and reducing the impact on the foot during exercise.

[0041] Embodiment 1

[0042] The raw materials of the sole material in this embodiment (by weight) include:

[0043] EVA 60 parts, shrinkage stop agent 5 parts, EPDM 8 parts, polyolefin elastomer 15 parts, SEBS 12 parts, wear agent 10 parts, talc 3 parts, stearic acid 0.5 parts, zinc oxide powder 1.2 parts, fast material 0.5 parts, environmentally friendly tackifier 0.5 parts, bridging agent 0.9 parts, medium temperature foaming agent 4.2 parts.

[0044] Among them, the content of vinyl acetate (VA) in EVA is 18%.

[0045] The preparation method of the sole material in this embodiment specifically comprises the following steps:

[0046] (1) Primary mixing: EVA, shrinkage stop agent, EPDM, polyolefin elastomer, SEBS, wear resistance agent, talcum powder, stearic acid, zinc oxide powder, quick-release material, environmentally friendly tackifier, bridging agent and medium-temperature foaming agent are put into a rinsing machine for mixing. The mixing time is 11.5 minutes and the mixing temperature is 123° C. to obtain a primary mixed material;

[0047] (2) Secondary kneading: The primary kneaded product was put into an open mill for cooling and dispersing kneading. The mixing time was 5.5 min and the mixing temperature was 90° C. The cooling and dispersing kneading was repeated 5 times to obtain a secondary kneaded product.

[0048] (3) Extrusion granulation: The secondary kneaded product is put into a granulator for extrusion granulation to obtain pellets;

[0049] (4) Injection molding: After the pellets are naturally cooled to room temperature, the pellets are matched with the mold and subjected to primary injection molding on a primary injection molding machine. The temperature of the primary injection molding machine is 175°C and the time is 500 seconds to obtain a rough blank;

[0050] (5) Molding: The rough blank is cooled and shrunk naturally. After the surface temperature of the rough blank drops to room temperature, it is sorted and packaged and left at room temperature for 12 hours. After the shrinkage of the rough blank stabilizes, it is molded. The molding temperature is 170°C, the heating time is 510s, and the cooling time is 510s to obtain a finished midsole.

[0051] It should be noted that after the raw materials are mixed once in the mill in step (1), they need to be mixed again in the open mixer in step (2). The purpose of the secondary mixing is to further mix the parts that were not mixed evenly in the first mixing, thereby improving the mixing effect; and to prepare for the subsequent granulation process. Since the temperature of the open mixer is lower than that of the mill, the secondary mixing also provides sufficient buffer time to stabilize the temperature of the material structure. Cooling on the open mixer can also ensure that the temperature is not easy to drop too much suddenly, so as to achieve the purpose of cooling and dispersing mixing, and avoid direct granulation when the temperature is too high, resulting in hardening.

[0052] Furthermore, the size, ratio, foaming holes, structure, surface and shape of the material after high-temperature foaming in step (5) are still in an unstable state. The rough blank is placed to wait for its surface temperature to drop to room temperature, and then placed and parked at room temperature for 12 hours to wait for the internal structure of the rough blank to stabilize and the internal temperature to drop, and then the rough blank is molded and formed after the shrinkage is stabilized.

[0053] Embodiment 2

[0054] The raw materials of the sole material in this embodiment (by weight) include:

[0055] 55 parts of EVA, 8 parts of shrinkage stopper, 8 parts of EPDM, 14 parts of polyolefin elastomer, 15 parts of SEBS, 10 parts of wear resistance agent, 3 parts of talc, 0.5 parts of stearic acid, 1.2 parts of zinc oxide powder, 0.5 parts of fast-acting material, 0.5 parts of environmentally friendly tackifier, 0.8 parts of bridging agent, and 4.1 parts of medium-temperature foaming agent.

[0056] Among them, the content of vinyl acetate (VA) in EVA is 18%.

[0057] The preparation method of the sole material in this embodiment specifically comprises the following steps:

[0058] (1) Primary mixing: EVA, shrinkage stop agent, EPDM, polyolefin elastomer, SEBS, wear resistance agent, talcum powder, stearic acid, zinc oxide powder, quick-release material, environmentally friendly tackifier, bridging agent and medium-temperature foaming agent are put into a rinsing machine for mixing. The mixing time is 12.5 minutes and the mixing temperature is 113° C. to obtain a primary mixed material;

[0059] (2) Secondary kneading: The primary kneaded product was placed in an open mill for cooling and dispersing kneading. The mixing time was 6 min and the mixing temperature was 85° C. The cooling and dispersing kneading was repeated 4 times to obtain a secondary kneaded product.

[0060] (3) Extrusion granulation: The secondary kneaded product is put into a granulator for extrusion granulation to obtain pellets;

[0061] (4) Injection molding: After the pellets are naturally cooled to room temperature, the pellets are matched with the mold and subjected to primary injection molding on a primary injection molding machine. The temperature of the primary injection molding machine is 175°C and the time is 500 seconds to obtain a rough blank;

[0062] (5) Molding: The rough blank is cooled and shrunk naturally. After the surface temperature of the rough blank drops to room temperature, it is sorted and packaged and left at room temperature for 12 hours. After the shrinkage of the rough blank stabilizes, it is molded. The molding temperature is 174°C, the heating time is 495 seconds, and the cooling time is 495 seconds to obtain a finished midsole.

[0063] It should be noted that after the raw materials are mixed once in the mill in step (1), they need to be mixed again in the open mixer in step (2). The purpose of the secondary mixing is to further mix the parts that were not mixed evenly in the first mixing, thereby improving the mixing effect; and to prepare for the subsequent granulation process. Since the temperature of the open mixer is lower than that of the mill, the secondary mixing also provides sufficient buffer time to stabilize the temperature of the material structure. Cooling on the open mixer can also ensure that the temperature is not easy to drop too much suddenly, so as to achieve the purpose of cooling and dispersing mixing, and avoid direct granulation when the temperature is too high, resulting in hardening.

[0064] Furthermore, the size, ratio, foaming holes, structure, surface and shape of the material after high-temperature foaming in step (5) are still in an unstable state. The rough blank is placed to wait for its surface temperature to drop to room temperature, and then placed and parked at room temperature for 12 hours to wait for the internal structure of the rough blank to stabilize and the internal temperature to drop, and then the rough blank is molded and formed after the shrinkage is stabilized.

[0065] Embodiment 3

[0066] The raw materials of the sole material in this embodiment (by weight) include:

[0067] EVA 43 parts, shrinkage stop agent 10 parts, EPDM 8 parts, polyolefin elastomer 19 parts, SEBS 20 parts, wear agent 12 parts, talc 3 parts, stearic acid 0.5 parts, zinc oxide powder 1.2 parts, fast material 0.5 parts, environmentally friendly tackifier 0.5 parts, bridging agent 0.8 parts, medium temperature foaming agent 4 parts.

[0068] Among them, the content of vinyl acetate (VA) in EVA is 18%.

[0069] The preparation method of the sole material in this embodiment specifically comprises the following steps:

[0070] (1) Primary mixing: EVA, shrinkage stop agent, EPDM, polyolefin elastomer, SEBS, wear resistance agent, talcum powder, stearic acid, zinc oxide powder, quick-release material, environmentally friendly tackifier, bridging agent and medium-temperature foaming agent are put into a rinsing machine for mixing. The mixing time is 12 minutes and the mixing temperature is 116° C. to obtain a primary mixed material;

[0071] (2) Secondary kneading: The primary kneaded product was placed in an open mixer for cooling and dispersing kneading. The mixing time was 6 min and the mixing temperature was 87° C. The cooling and dispersing kneading was repeated 4 times to obtain a secondary kneaded product.

[0072] (3) Extrusion granulation: The secondary kneaded product is put into a granulator for extrusion granulation to obtain pellets;

[0073] (4) Injection molding: After the pellets are naturally cooled to room temperature, the pellets are matched with the mold and subjected to primary injection molding on a primary injection molding machine. The temperature of the primary injection molding machine is 175°C and the time is 500 seconds to obtain a rough blank;

[0074] (5) Molding: The rough blank is cooled and shrunk naturally. After the surface temperature of the rough blank drops to room temperature, it is sorted and packaged and left at room temperature for 12 hours. After the shrinkage of the rough blank stabilizes, it is molded. The molding temperature is 176°C, the heating time is 480 seconds, and the cooling time is 480 seconds to obtain a finished midsole.

[0075] It should be noted that after the raw materials are mixed once in the mill in step (1), they need to be mixed again in the open mixer in step (2). The purpose of the secondary mixing is to further mix the parts that were not mixed evenly in the first mixing, thereby improving the mixing effect; and to prepare for the subsequent granulation process. Since the temperature of the open mixer is lower than that of the mill, the secondary mixing also provides sufficient buffer time to stabilize the temperature of the material structure. Cooling on the open mixer can also ensure that the temperature is not easy to drop too much suddenly, so as to achieve the purpose of cooling and dispersing mixing, and avoid direct granulation when the temperature is too high, resulting in hardening.

[0076] Furthermore, the size, ratio, foaming holes, structure, surface and shape of the material after high-temperature foaming in step (5) are still in an unstable state. The rough blank is placed to wait for its surface temperature to drop to room temperature, and then placed and parked at room temperature for 12 hours to wait for the internal structure of the rough blank to stabilize and the internal temperature to drop, and then the rough blank is molded and formed after the shrinkage is stabilized.

[0077] Embodiment 4

[0078] The raw materials of the sole material in this embodiment (by weight) include:

[0079] EVA 45 parts, shrinkage stop agent 10 parts, EPDM 10 parts, polyolefin elastomer 15 parts, SEBS 20 parts, wear agent 12 parts, talc 3 parts, stearic acid 0.5 parts, zinc oxide powder 1.2 parts, fast material 0.5 parts, environmentally friendly tackifier 0.5 parts, bridging agent 0.8 parts, medium temperature foaming agent 4 parts.

[0080] Among them, the content of vinyl acetate (VA) in EVA is 18%.

[0081] The preparation method of the sole material in this embodiment specifically comprises the following steps:

[0082] (1) Primary mixing: EVA, shrinkage stop agent, EPDM, polyolefin elastomer, SEBS, wear resistance agent, talcum powder, stearic acid, zinc oxide powder, quick-release material, environmentally friendly tackifier, bridging agent and medium-temperature foaming agent are put into a rinsing machine for mixing. The mixing time is 12 minutes and the mixing temperature is 118° C. to obtain a primary mixed material;

[0083] (2) Secondary kneading: The primary kneaded product was put into an open mill for cooling and dispersing kneading. The mixing time was 6.5 min and the mixing temperature was 80° C. The cooling and dispersing kneading was repeated 3 times to obtain a secondary kneaded product.

[0084] (3) Extrusion granulation: The secondary kneaded product is put into a granulator for extrusion granulation to obtain pellets;

[0085] (4) Injection molding: After the pellets are naturally cooled to room temperature, the pellets are matched with the mold and subjected to primary injection molding on a primary injection molding machine. The temperature of the primary injection molding machine is 175°C and the time is 500 seconds to obtain a rough blank;

[0086] (5) Molding: The rough blank is cooled and shrunk naturally. After the surface temperature of the rough blank drops to room temperature, it is sorted and packaged and left at room temperature for 12 hours. After the shrinkage of the rough blank stabilizes, it is molded. The molding temperature is 180°C, the heating time is 450 seconds, and the cooling time is 450 seconds to obtain a finished midsole.

[0087] It should be noted that after the raw materials are mixed once in the mill in step (1), they need to be mixed again in the open mixer in step (2). The purpose of the secondary mixing is to further mix the parts that were not mixed evenly in the first mixing, thereby improving the mixing effect; and to prepare for the subsequent granulation process. Since the temperature of the open mixer is lower than that of the mill, the secondary mixing also provides sufficient buffer time to stabilize the temperature of the material structure. Cooling on the open mixer can also ensure that the temperature is not easy to drop too much suddenly, so as to achieve the purpose of cooling and dispersing mixing, and avoid direct granulation when the temperature is too high, resulting in hardening.

[0088] Furthermore, the size, ratio, foaming holes, structure, surface and shape of the material after high-temperature foaming in step (5) are still in an unstable state. The rough blank is placed to wait for its surface temperature to drop to room temperature, and then placed and parked at room temperature for 12 hours to wait for the internal structure of the rough blank to stabilize and the internal temperature to drop, and then the rough blank is molded and formed after the shrinkage is stabilized.

[0089] Test example

[0090] The hardness, specific gravity, wear resistance and resilience of the sole materials prepared in Examples 1 to 4 were tested, wherein Example 4 is a preferred embodiment of the present invention. The test results are shown in Table 2.

[0091] Among them, the test method for hardness is HG / T 2489-2007 (Shore C durometer test), the test method for specific gravity is the water bath method, the test method for wear resistance is GB / T 3903.2-2017 (XM wear method), and the test method for resilience is HG / T4993-2016 (impact pendulum test).

[0092] Table 2 Test results of the sole material of the present invention

[0093] Test items Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Hardness (C) 64 62 60 60 <![CDATA[Specific gravity (g / cm 3 )]]> 0.27 0.27 0.26 0.28 Wear resistance(mm) 12 11 10.5 9.5 Resilience(%) 48％ 50％ 53％ 57％

[0094] From the test results, it can be seen that as the weight of EVA in the formula decreases, the hardness of the sole material tends to decrease, while the resilience tends to increase, that is, the lightness, comfort and cushioning effect are improved. Secondly, polyolefin elastomer is added to the formula, so that the sole material of each embodiment is kept at a low specific gravity, that is, lightweight.

[0095] In addition, with the increase in the weight percentage of EPDM, SEBS and wear-resistant agent in the formula, the wear scar length of the sole material tends to decrease, that is, the wear resistance is improved. The increase in the weight percentage of SEBS also promotes the increase in the resilience of the sole material.

[0096] In summary, the sole material of the present invention has good wear resistance, resilience and lightness. By adjusting the formula and the preparation method, the wear resistance, resilience and lightness of Example 4 achieve a balanced effect, so that the user can save more effort when wearing shoes during exercise, reduce the force of a single exercise, thereby effectively reducing exercise fatigue, allowing more sustained exercise, and helping the user to improve his or her athletic performance.

[0097] The EVA sole material provided by the invention can directly touch the ground without the need for rubber veneer combination, thus simplifying the process, improving the production efficiency and reducing the labor cost.

[0098] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A sole material, characterized in that: In parts by weight, it includes: EVA 40-60 parts, shrinkage stop agent 5-10 parts, EPDM 5-10 parts, polyolefin elastomer 10-20 parts, SEBS 10-25 parts, wear agent 10-15 parts, talc 2-5 parts, stearic acid 0.3-0.8 parts, zinc oxide powder 1-1.5 parts, quick-acting material 0.3-0.8 parts, environmentally friendly tackifier 0.3-0.8 parts, bridging agent 0.6-1 parts, medium-temperature foaming agent 3.5-4.5 parts.

2. The sole material according to claim 1, characterized in that: In parts by weight, it includes: 45 parts of EVA, 10 parts of shrinkage stopper, 10 parts of EPDM, 15 parts of polyolefin elastomer, 20 parts of SEBS, 12 parts of wear resistance agent, 3 parts of talc, 0.5 parts of stearic acid, 1.2 parts of zinc oxide powder, 0.5 parts of fast-acting material, 0.5 parts of environmentally friendly tackifier, 0.8 parts of bridging agent, and 4 parts of medium-temperature foaming agent.

3. The sole material according to claim 1 or 2, characterized in that: The content of vinyl acetate in the EVA is 18% to 26%.

4. A method for preparing a sole material according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) primary mixing: EVA, shrinkage stop agent, EPDM, polyolefin elastomer, SEBS, wear resistance agent, talcum powder, stearic acid, zinc oxide powder, quick-release material, environmentally friendly tackifier, bridging agent and medium-temperature foaming agent are put into a rinsing machine for mixing to obtain a primary mixed material; (2) Secondary mixing: the primary mixed material is put into an open mixer for cooling, dispersion and mixing to obtain a secondary mixed material; (3) Extrusion granulation: The secondary kneaded product is put into a granulator for extrusion granulation to obtain pellets; (4) Injection molding: After the pellets are cooled to room temperature, the pellets are matched with a mold and subjected to a primary injection molding on an injection molding machine to obtain a rough blank; (5) Molding: The rough blank is cooled and shrunk naturally. After the surface temperature of the rough blank drops to room temperature, it is sorted and packaged and continues to be parked at room temperature. After the shrinkage of the rough blank is stable, it is molded to obtain a finished midsole.

5. The method for preparing the sole material according to claim 4, characterized in that: In step (1), the mixing time of the mixer is 11.5 to 12.5 minutes, and the temperature is 113 to 123°C.

6. The method for preparing the sole material according to claim 4, characterized in that: In step (2), the time for secondary mixing in the open mill is 5.5 to 6.5 minutes, and the temperature is 80 to 90°C.

7. The method for preparing the sole material according to claim 6, characterized in that: In step (2), the cooling and dispersion kneading is repeated 3 to 5 times on the primary kneaded product.

8. The method for preparing the sole material according to claim 4, characterized in that: In step (4), the temperature of the primary injection molding machine is 175° C. and the time is 500 s.

9. The method for preparing the sole material according to claim 4, characterized in that: In step (5), the rough blank is sorted and packaged and then left at room temperature for 12 hours.

10. The method for preparing the sole material according to claim 9, characterized in that: In step (5), the molding temperature is 170-180° C., the heating time is 450-510 s, and the cooling time is 450-510 s.

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