A multi-material midsole blank suitable for synchronous foaming and a method of manufacturing the same

Abstract

The application discloses a multi-material insole blank suitable for synchronous foaming and a preparation method thereof. The insole blank comprises a surrounding strip part and a filling part, and the surrounding strip part is arranged on the periphery of the filling part. The surrounding strip part is made of a first material, and the filling part is made of a second material. The first material mainly comprises 40-50 parts of a first ethylene-vinyl acetate copolymer, 10-15 parts of a second ethylene-vinyl acetate copolymer, 20-25 parts of a polyolefin elastomer, 10-20 parts of a hydrogenated styrene-butadiene block copolymer, 2-10 parts of a ternary ethylene-propylene rubber and other auxiliary components. The second material mainly comprises 20-30 parts of the first ethylene-vinyl acetate copolymer, 25-30 parts of the second ethylene-vinyl acetate copolymer, 15-20 parts of the polyolefin elastomer, 20-25 parts of the hydrogenated styrene-butadiene block copolymer, 2-5 parts of the ternary ethylene-propylene rubber and other auxiliary components. The multi-material insole blank can improve the deformation and the cracking of the joint after the insole with the multi-material is synchronously foamed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of midsole materials, in particular to a multi-material midsole blank suitable for synchronous foaming and a preparation method thereof. BACKGROUND

[0002] In order to improve the different performances of the midsole of the shoe corresponding to different positions of the human foot, different materials or midsole materials with different performances can be used in different parts of the midsole of the shoe. The existing midsole is generally prepared by foaming materials such as EVA, TPEE, etc. When at least two foaming materials are used to prepare the midsole, the two materials need to be spliced before foaming. This splicing is generally connected by glue, and then foaming is performed. However, due to the different foaming rates of different materials under the same temperature and environment, if synchronous foaming is performed, the midsole after foaming will be deformed, and the joint of different materials will be cracked. SUMMARY

[0003] The purpose of the present application is to overcome the above-mentioned defects or problems existing in the background art, and to provide a multi-material midsole blank suitable for synchronous foaming and a preparation method thereof, which can improve the deformation and joint cracking of the midsole after synchronous foaming.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0005] A multi-material midsole blank suitable for synchronous foaming, comprising a surrounding strip part and a filling part, the surrounding strip part being arranged around the filling part; the surrounding strip part is made of a first material, and the filling part is made of a second material; the first material comprises the following components by mass fraction: 40-50 parts of first ethylene vinyl acetate copolymer; 10-15 parts of second ethylene vinyl acetate copolymer; 20-25 parts of polyolefin elastomer; 10-20 parts of hydrogenated styrene-butadiene block copolymer; 2-10 parts of ternary ethylene-propylene rubber; 0.2-0.5 parts of active agent; 0.5-1 parts of auxiliary agent; 0.5-1 parts of crosslinking agent; 4-8 parts of low-temperature foaming agent; the second material comprises the following components by mass fraction: 20-30 parts of first ethylene vinyl acetate copolymer; 25-30 parts of second ethylene vinyl acetate copolymer; 15-20 parts of polyolefin elastomer; 20-25 parts of hydrogenated styrene-butadiene block copolymer; 2-5 parts of ternary ethylene-propylene rubber; 9-10 parts of wear-resistant agent; 0.2-0.5 parts of active agent; 0.5-1 parts of auxiliary agent; 0.5-1 parts of crosslinking agent; 4-8 parts of low-temperature foaming agent; wherein the content of vinyl acetate in the first ethylene vinyl acetate copolymer is 26%, and the content of vinyl acetate in the second ethylene vinyl acetate copolymer is 33%.

[0006] Further, the hydrogenated styrene-butadiene block copolymer is a star-shaped SEBS with a molecular weight of 300,000 to 350,000.

[0007] Further, the polyolefin elastomer brand is POE8003.

[0008] Further, the active agent adopts stearic acid.

[0009] Further, the wear-resistant agent adopts silicone wear-resistant agent.

[0010] Further, the auxiliary agent adopts zinc carbonate.

[0011] Further, the cross-linking agent adopts dicumyl peroxide.

[0012] Further, the low-temperature foaming agent adopts white azodicarbonamide.

[0013] In addition, the application further provides a preparation method of the multi-material midsole blank suitable for synchronous foaming, which is based on the components of the first material and the second material provided by the multi-material midsole blank suitable for synchronous foaming material according to any one of the technical solutions one to seven, and is prepared by the following steps: preparing the first material: weighing other components in the first material except the auxiliary agent and the cross-linking agent according to the mass fraction, and mixing at 115±5℃ for 10-15min; then adding the auxiliary agent and the cross-linking agent, and mixing at 120±5℃ for 10-15min; preparing the second material: weighing other components in the second material except the auxiliary agent and the cross-linking agent according to the mass fraction, and mixing at 115±5℃ for 10-15min; then adding the auxiliary agent and the cross-linking agent, and mixing at 120±5℃ for 10-15min; preparing the midsole blank: extruding the first material and the second material in the molten state after mixing into the blank mold respectively, and surrounding the first material around the second material, so that the first material and the second material are bonded at the joint, and then cooling to obtain the midsole blank.

[0014] From the above description of the application, the application has the following beneficial effects relative to the prior art:

[0015] The application provides a multi-material midsole blank suitable for synchronous foaming, which is provided with a surrounding strip part at the position of the periphery and a filling part inside the surrounding strip part, wherein the surrounding strip part is prepared from the first material, and the filling part is prepared from the second material, the material of the surrounding strip part has better supporting performance, and the material of the filling part has better shock-absorbing performance.

[0016] In the application, the main components of the first material and the second material are all ethylene vinyl acetate copolymer, polyolefin elastomer and hydrogenated styrene-butadiene block copolymer, but due to the different positions of the first material and the second material in the midsole blank, the formula proportions of the two are quite different, by finely adjusting the mass proportions of the corresponding components, the first material enhances the support performance on the basis of better resilience, and the second material further enhances the resilience and shock absorption performance; at the same time, although the first material and the second material have different foaming ratios when they are foamed synchronously under different mass proportions, the shrinkage degrees of the two are basically the same in the cooling process after foaming due to the use of basically the same components, and the deformation of the midsole after foaming is caused by the inconsistent shrinkage degrees in the shrinkage process; and, in the first material and the second material, polyolefin elastomer is also added, which can help the surrounding strip part and the filling part maintain good shape stability in the shrinkage process; in addition, if the midsole after foaming deforms, it will also cause the position originally connected by glue between different materials to crack, and the surrounding strip part and the filling part in the application are bonded together when being injected, and physical cross-linking will occur at the bonding position of the surrounding strip part and the filling part during foaming, forming a space network structure, so that even if there is slight deformation of the surrounding strip part and the filling part in the cooling process after foaming, the connection of the two is very firm, and the edges of the two materials at the joint will not be uneven.

[0017] In the application, two kinds of ethylene vinyl acetate copolymers with different VA contents are used in the components, wherein the EVA with a VA content of 26% can provide basic hardness and wear resistance, so that the final material has good shock absorption effect, and the EVA with a VA content of 33% can bring better softness and elasticity to the material, so that the final material has good resilience; the amounts of the two kinds of ethylene vinyl acetate copolymers in the first material and the second material are different, thereby bringing different physical properties to the surrounding strip part and the filling part.

[0018] In addition, hydrogenated styrene-butadiene block copolymer is also specially added, and preferably star-shaped SEBS with a molecular weight of 300,000 to 350,000, adding a certain amount of star-shaped SEBS can improve the anti-deformation ability of the first material and the second material, and the first material and the second material can better maintain their own shapes in the shrinkage process after foaming. And SEBS itself has good mechanical properties, which can cooperate with ethylene vinyl acetate copolymer and polyolefin elastomer to improve the resilience of the final material, and also can improve the surface finish of the product.

[0019] The low-temperature foaming agent can reduce the influence of the color of the foaming agent on the final material, and the foaming at low temperature can reduce the overall foaming ratio, so that the foaming ratio difference between the first material and the second material is reduced, and the deformation of the midsole after foaming is further improved. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are preferred embodiments of the present application, and should not be regarded as exclusive to other embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] In the claims and specification of the present application, the terms "comprise", "have" and their variants are intended to mean "include but not limited to".

[0022] The present application provides a multi-material midsole blank suitable for synchronous foaming and a preparation method thereof, the multi-material midsole blank comprising a surrounding strip part and a filling part, the surrounding strip part being arranged around the filling part; the surrounding strip part is made of a first material, and the filling part is made of a second material; the first material comprises the following components in mass fraction: 40-50 parts of first ethylene-vinyl acetate copolymer; 10-15 parts of second ethylene-vinyl acetate copolymer; 20-25 parts of polyolefin elastomer; 10-20 parts of hydrogenated styrene-butadiene block copolymer; 2-10 parts of ternary ethylene-propylene rubber; 0.2-0.5 parts of active agent; 0.5-1 parts of auxiliary agent; 0.5-1 parts of crosslinking agent; and 4-8 parts of low-temperature foaming agent; the second material comprises the following components in mass fraction: 20-30 parts of first ethylene-vinyl acetate copolymer; 25-30 parts of second ethylene-vinyl acetate copolymer; 15-20 parts of polyolefin elastomer; 20-25 parts of hydrogenated styrene-butadiene block copolymer; 2-5 parts of ternary ethylene-propylene rubber; 9-10 parts of wear-resistant agent; 0.2-0.5 parts of active agent; 0.5-1 parts of auxiliary agent; 0.5-1 parts of crosslinking agent; and 4-8 parts of low-temperature foaming agent; wherein the content of vinyl acetate in the first ethylene-vinyl acetate copolymer is 26%, and the content of vinyl acetate in the second ethylene-vinyl acetate copolymer is 33%.

[0023] In addition, the hydrogenated styrene-butadiene block copolymer therein is star-shaped SEBS with a molecular weight of 300,000 to 350,000, and the brand is Balin Petrochemical 604T. The wear-resistant agent is an organic silicon wear-resistant agent, specifically a silicone coupling agent. The active agent is stearic acid. The auxiliary agent is zinc carbonate. The crosslinking agent is dicumyl peroxide. The low-temperature foaming agent is white azodicarbonamide.

[0024] The multi-material midsole blank suitable for synchronous foaming based on the components of the first material and the second material is prepared by the following steps:

[0025] Step 1: Preparation of the first material: the components of the first material except the auxiliary agent and the crosslinking agent are weighed according to the mass fraction, and are mixed at a temperature of 115±5℃ for 10-15 min; then the auxiliary agent and the crosslinking agent are added, and are mixed at a temperature of 120±5℃ for 10-15 min;

[0026] Step 2: Preparation of the second material: the components of the second material except the auxiliary agent and the crosslinking agent are weighed according to the mass fraction, and are mixed at a temperature of 115±5℃ for 10-15 min; then the auxiliary agent and the crosslinking agent are added, and are mixed at a temperature of 120±5℃ for 10-15 min;

[0027] Step 3: Preparation of the midsole blank: the first material and the second material in a molten state after mixing are respectively injected into the blank mold, and the first material is wrapped around the second material, so that the first material and the second material are bonded at the joint, and then the midsole blank is obtained after being cooled.

[0028] After the midsole blank is prepared, it is placed in a foaming mold, the mold temperature is set to 172±3℃, and the mold is vacuumized. As the temperature of the blank increases from the surface to the inside, the whole blank is in a molten state, and the surrounding strip part and the filling part of the blank gradually expand under the action of the foaming agent. After 4-4.5 h, the foaming is completed, and the foamed midsole is obtained.

[0029] The application provides a multi-material midsole blank suitable for synchronous foaming, which is provided with a surrounding strip part at a circumferential position and a filling part inside the surrounding strip part, wherein the surrounding strip part is prepared by using a first material, and the filling part is prepared by using a second material. The material used for the surrounding strip part has better supporting performance, and the material used for the filling part has better shock-absorbing performance.

[0030] In the application, the main components of the first material and the second material are all ethylene vinyl acetate copolymer, polyolefin elastomer and hydrogenated styrene-butadiene block copolymer, but due to the different positions of the first material and the second material in the midsole blank, the formula proportions of the two are quite different, by finely adjusting the mass proportions of the corresponding components, the first material enhances the support performance on the basis of better resilience, and the second material further enhances the resilience and shock absorption performance; at the same time, although the first material and the second material have different foaming ratios when they are foamed synchronously under different mass proportions, the shrinkage degrees of the two are basically the same in the cooling process after foaming due to the use of basically the same components, and the deformation of the midsole after foaming is caused by the inconsistent shrinkage degrees in the shrinkage process; and, in the first material and the second material, polyolefin elastomer is also added, which can help the surrounding strip part and the filling part maintain good shape stability in the shrinkage process; in addition, if the midsole after foaming deforms, it will also cause the position originally connected by glue between different materials to crack, and the surrounding strip part and the filling part in the application are bonded together when being injected, and physical cross-linking will occur at the bonding position of the surrounding strip part and the filling part during foaming, forming a space net structure, so that even if there is slight deformation of the surrounding strip part and the filling part in the cooling process after foaming, the connection of the two is very firm, and the edges of the two materials at the joint will not be uneven.

[0031] In the application, two kinds of ethylene vinyl acetate copolymers with different VA contents are used in the components, wherein the EVA with a VA content of 26% can provide basic hardness and wear resistance, so that the final material has good shock absorption effect, and the EVA with a VA content of 33% can bring better softness and elasticity to the material, so that the final material has good resilience; the amounts of the two kinds of ethylene vinyl acetate copolymers in the first material and the second material are different, thereby bringing different physical properties to the surrounding strip part and the filling part.

[0032] In addition, hydrogenated styrene-butadiene block copolymer is also specially added, and preferably star-shaped SEBS with a molecular weight of 300,000 to 350,000, adding a certain amount of star-shaped SEBS can improve the anti-deformation ability of the first material and the second material, and the first material and the second material can better maintain their own shapes in the shrinkage process after foaming. And SEBS itself has good mechanical properties, which can cooperate with ethylene vinyl acetate copolymer and polyolefin elastomer to improve the resilience of the final material, and also can improve the surface finish of the product.

[0033] The low-temperature foaming agent can reduce the influence of the color of the foaming agent on the final material, and the foaming at low temperature can reduce the overall foaming ratio, so that the difference in the foaming ratio of the first material and the second material is reduced, and the deformation of the midsole after foaming is further improved.

[0034] To further illustrate the performance of the multi-material midsole blank suitable for synchronous foaming provided by the present application, the following examples and comparative examples are provided.

[0035] Example 1

[0036] The components are weighed as follows:

[0037] The first material: first ethylene vinyl acetate copolymer: 42 parts; second ethylene vinyl acetate copolymer: 12 parts; polyolefin elastomer: 24 parts; hydrogenated styrene-butadiene block copolymer: 18 parts; ternary ethylene-propylene rubber: 4 parts; active agent: 0.44 parts; auxiliary agent: 0.8 parts; crosslinking agent: 0.56 parts; low-temperature foaming agent: 4.5 parts.

[0038] The second material: first ethylene vinyl acetate copolymer: 25 parts; second ethylene vinyl acetate copolymer: 30 parts; polyolefin elastomer: 20 parts; hydrogenated styrene-butadiene block copolymer: 22 parts; ternary ethylene-propylene rubber: 3 parts; wear-resistant agent: 9.23 parts; active agent: 0.46 parts; auxiliary agent: 0.9 parts; crosslinking agent: 0.63 parts; low-temperature foaming agent: 6.2 parts.

[0039] The content of ethylene vinyl acetate in the first ethylene vinyl acetate copolymer is 26%, and the content of ethylene vinyl acetate in the second ethylene vinyl acetate copolymer is 33%. The hydrogenated styrene-butadiene block copolymer is a star-shaped SEBS with a molecular weight of 300,000 to 350,000, and the brand is Balin Petrochemical 604T. The wear-resistant agent is an organic silicon wear-resistant agent, specifically a silicone coupling agent. The active agent is stearic acid. The auxiliary agent is zinc carbonate. The high crosslinking agent is dicumyl peroxide. The low-temperature foaming agent is white azodicarbonamide.

[0040] The above components are used as raw materials, and the following steps are performed to obtain a multi-material midsole blank:

[0041] Step 1: Preparation of the first material: weigh the components in the first material except the auxiliary agent and the crosslinking agent according to the mass fraction, and mix at 115°C for 10 min; then add the auxiliary agent and the crosslinking agent, and mix at 120°C for 10 min;

[0042] Step 2: Preparation of the second material: weigh the components in the second material except the auxiliary agent and the crosslinking agent according to the mass fraction, and mix at 115°C for 10 min; then add the auxiliary agent and the crosslinking agent, and mix at 120°C for 10 min;

[0043] Step three: preparing the midsole blank: the first material and the second material in molten state after mixing are respectively injected into the blank mold, and the first material is wrapped around the second material, so that the junction of the first material and the second material is bonded, and then the midsole blank is obtained after standing and cooling.

[0044] Example 2

[0045] The components are taken by mass fraction as follows:

[0046] The first material: first ethylene vinyl acetate copolymer: 45 parts; second ethylene vinyl acetate copolymer: 10 parts; polyolefin elastomer: 23 parts; hydrogenated styrene-butadiene block copolymer: 17 parts; ternary ethylene-propylene rubber: 5 parts; active agent: 0.42 parts; auxiliary agent: 0.75 parts; crosslinking agent: 0.6 parts; low-temperature foaming agent: 5 parts.

[0047] The second material: first ethylene vinyl acetate copolymer: 26 parts; second ethylene vinyl acetate copolymer: 29 parts; polyolefin elastomer: 18 parts; hydrogenated styrene-butadiene block copolymer: 21 parts; ternary ethylene-propylene rubber: 4 parts; wear-resistant agent: 9.5 parts; active agent: 0.48 parts; auxiliary agent: 0.85 parts; crosslinking agent: 0.65 parts; low-temperature foaming agent: 6.5 parts.

[0048] Among them, the content of ethylene vinyl acetate in the first ethylene vinyl acetate copolymer is 26%, and the content of ethylene vinyl acetate in the second ethylene vinyl acetate copolymer is 33%. The hydrogenated styrene-butadiene block copolymer adopts star-shaped SEBS with a molecular weight of 300,000 to 350,000, and the brand is Balin Petrochemical 604T. The wear-resistant agent adopts silicone wear-resistant agent, specifically silicone coupling agent. The active agent adopts stearic acid. The auxiliary agent adopts zinc carbonate. The high crosslinking agent adopts dicumyl peroxide. The low-temperature foaming agent adopts white azodicarbonamide.

[0049] The above components are used as raw materials, and the following steps are performed to obtain a multi-material midsole blank:

[0050] Step one: preparing the first material: the components in the first material except the auxiliary agent and the crosslinking agent are taken by mass fraction, and mixed at a temperature of 115°C for 15 minutes; then the auxiliary agent and the crosslinking agent are added, and mixed at a temperature of 120°C for 15 minutes;

[0051] Step two: preparing the second material: the components in the second material except the auxiliary agent and the crosslinking agent are taken by mass fraction, and mixed at a temperature of 115°C for 15 minutes; then the auxiliary agent and the crosslinking agent are added, and mixed at a temperature of 120°C for 15 minutes;

[0052] Step three: preparing the midsole blank: the first material and the second material in molten state after mixing are respectively injected into the blank mold, and the first material is wrapped around the second material, so that the junction of the first material and the second material is bonded, and then the midsole blank is obtained after standing and cooling.

[0053] Example 3

[0054] The components are taken by mass fraction as follows:

[0055] The first material: first ethylene vinyl acetate copolymer: 43 parts; second ethylene vinyl acetate copolymer: 11 parts; polyolefin elastomer: 22 parts; hydrogenated styrene-butadiene block copolymer: 16 parts; ternary ethylene-propylene rubber: 4 parts; active agent: 0.4 parts; auxiliary agent: 0.78 parts; crosslinking agent: 0.58 parts; low-temperature foaming agent: 4.8 parts.

[0056] The second material: first ethylene vinyl acetate copolymer: 24 parts; second ethylene vinyl acetate copolymer: 28 parts; polyolefin elastomer: 19 parts; hydrogenated styrene-butadiene block copolymer: 23 parts; ternary ethylene-propylene rubber: 3 parts; wear-resistant agent: 9.8 parts; active agent: 0.45 parts; auxiliary agent: 0.88 parts; crosslinking agent: 0.62 parts; low-temperature foaming agent: 6.3 parts.

[0057] The content of ethylene vinyl acetate in the first ethylene vinyl acetate copolymer is 26%, and the content of ethylene vinyl acetate in the second ethylene vinyl acetate copolymer is 33%. The hydrogenated styrene-butadiene block copolymer is star-shaped SEBS with a molecular weight of 300,000 to 350,000, and the brand is Balin Petrochemical 604T. The wear-resistant agent is an organic silicon wear-resistant agent, specifically a silicone coupling agent. The active agent is stearic acid. The auxiliary agent is zinc carbonate. The high crosslinking agent is dicumyl peroxide. The low-temperature foaming agent is white azodicarbonamide.

[0058] The above components are used as raw materials, and the following steps are taken to prepare a multi-material midsole blank:

[0059] Step one: preparing the first material: the components in the first material except the auxiliary agent and the crosslinking agent are taken by mass fraction, and mixed at a temperature of 115°C for 15 minutes; then the auxiliary agent and the crosslinking agent are added, and mixed at a temperature of 120°C for 15 minutes;

[0060] Step two: preparing the second material: the components in the second material except the auxiliary agent and the crosslinking agent are taken by mass fraction, and mixed at a temperature of 115°C for 15 minutes; then the auxiliary agent and the crosslinking agent are added, and mixed at a temperature of 120°C for 15 minutes;

[0061] Step three: preparing the midsole blank: the first material and the second material in molten state after mixing are respectively injected into the blank mold, and the first material is wrapped around the second material, so that the first material and the second material are bonded at the joint, and then the midsole blank is obtained after standing and cooling.

[0062] Comparative Example 1

[0063] Based on Example 1, the difference is that in the formula component, neither the first material nor the second material includes the component of polyolefin elastomer.

[0064] Comparative Example 2

[0065] Based on Example 1, the difference is that in the formula component, the first ethylene vinyl acetate in the first material is replaced by thermoplastic polyester elastomer TPEE.

[0066] Comparative Example 3

[0067] Based on Example 1, the difference is that in the formula component, neither the first material nor the second material includes the component of hydrogenated styrene-butadiene block copolymer.

[0068] The multi-material midsole blanks prepared in the above Examples 1, 2, 3 and Comparative Examples 1, 2, 3 after cooling are foamed under the same conditions. The foaming process is as follows: the blank is placed in a foaming mold, the mold temperature is set to 172±3℃, and the mold is vacuumed. After 4-4.5h, the foaming is completed, and the foamed midsole is obtained.

[0069] The foamed midsoles obtained after foaming of the above Examples 1, 2, 3 and Comparative Examples 1, 2, 3 are inspected by visual and tactile methods. The foamed midsoles prepared in Examples 1, 2, 3 are basically free of deformation, and the boundary of the surrounding strip part and the filling part is clear and free of cracking. The foamed midsole prepared in Comparative Example 1 has a certain degree of deformation, and the surrounding strip part and the filling part joint have cracks. The foamed midsole prepared in Comparative Example 2 has a greater degree of deformation than Comparative Example 1, and the surrounding strip part and the filling part joint have a larger degree of cracking. The foamed midsole prepared in Comparative Example 3 has a certain degree of deformation, and the surrounding strip part and the filling part joint have a certain degree of cracking. Through the inspection, it can be seen that compared with Examples 1, 2, 3, Comparative Examples 1, 2, 3 all have different degrees of deformation and cracking, which shows that the multi-material midsole blank suitable for synchronous foaming provided by the present application can improve the deformation and joint cracking of the midsole after synchronous foaming.

[0070] The above description and the examples are intended to explain the scope of the present application, but not to limit the scope of the present application. Modifications, equivalent replacements or other improvements based on the conception of the present application or the above examples, which can be obtained by those skilled in the art with common knowledge, common technical knowledge and / or prior art, through logical analysis, reasoning or limited tests, shall be included in the scope of the present application.

Claims

1. A multi-material midsole precursor adapted for simultaneous foaming, characterized in that, The girdle part is arranged around the filling part, the girdle part adopts a first material, and the filling part adopts a second material; The first material comprises the following components by mass fraction: The first ethylene-vinyl acetate copolymer is 40-50 parts; the second ethylene-vinyl acetate copolymer is 10-15 parts; the polyolefin elastomer is 20-25 parts; the hydrogenated styrene-butadiene block copolymer is 10-20 parts; the ternary ethylene-propylene rubber is 2-10 parts; the active agent is 0.2-0.5 parts; the auxiliary agent is 0.5-1 part; the crosslinking agent is 0.5-1 part; and the low-temperature foaming agent is 4-8 parts. The second material comprises the following components by mass fraction: The first ethylene-vinyl acetate copolymer is 20-30 parts; The second ethylene-vinyl acetate copolymer is 25-30 parts; the polyolefin elastomer is 15-20 parts; the hydrogenated styrene-butadiene block copolymer is 20-25 parts; the ternary ethylene-propylene rubber is 2-5 parts; the wear-resistant agent is 9-10 parts; the active agent is 0.2-0.5 parts; the auxiliary agent is 0.5-1 part; the crosslinking agent is 0.5-1 part; and the low-temperature foaming agent is 4-8 parts. The content of vinyl acetate in the first ethylene-vinyl acetate copolymer is 26%, and the content of vinyl acetate in the second ethylene-vinyl acetate copolymer is 33%.

2. A multi-material midsole precursor suitable for simultaneous foaming according to claim 1, wherein, The hydrogenated styrene-butadiene block copolymer is star-shaped SEBS with a molecular weight of 300,000-350,000.

3. A multi-material midsole precursor suitable for simultaneous foaming as in claim 2, wherein, The polyolefin elastomer is POE8003.

4. A multi-material midsole precursor suitable for simultaneous foaming as in claim 1, wherein, The active agent is stearic acid.

5. A multi-material midsole precursor suitable for simultaneous foaming as in claim 1, wherein The wear-resistant agent is an organic silicon wear-resistant agent.

6. A multi-material midsole precursor suitable for simultaneous foaming as in claim 1, wherein, The auxiliary agent is zinc carbonate.

7. A multi-material midsole precursor suitable for simultaneous foaming as in claim 1, wherein, The crosslinking agent is dicumyl peroxide.

8. A multi-material midsole precursor suitable for simultaneous foaming as in claim 1, wherein, The low-temperature foaming agent is white azodicarbonamide.

9. A method for preparing a multi-material midsole preform suitable for simultaneous foaming, characterized in that, Based on the components of the first material and the second material provided by the multi-material midsole blank suitable for synchronous foaming according to any one of claims 1-8, the following steps are used for preparation: Preparation of the first material: the components other than the auxiliary agent and the crosslinking agent in the first material are weighed according to the mass fraction, and are mixed at a temperature of 115±5℃ for 10-15 minutes; then the auxiliary agent and the crosslinking agent are added, and are mixed at a temperature of 120±5℃ for 10-15 minutes; Preparation of the second material: the components other than the auxiliary agent and the crosslinking agent in the second material are weighed according to the mass fraction, and are mixed at a temperature of 115±5℃ for 10-15 minutes; then the auxiliary agent and the crosslinking agent are added, and are mixed at a temperature of 120±5℃ for 10-15 minutes; Preparation of the midsole blank: the first material and the second material in a molten state after mixing are respectively injected into a blank mold, the first material is arranged around the second material, the junction of the first material and the second material is bonded, and then the midsole blank is obtained after standing and cooling.