Preparation method of skin-friendly soft foaming material

Abstract

The invention discloses a preparation method of a skin-friendly soft foaming material. The preparation method comprises the following steps: 1, mixing an ethylene-vinyl acetate copolymer, a polyolefin elastomer, a hydrogenated styrene-butadiene block copolymer and naphthenic oil; step 2, adding an auxiliary agent and a cross-linking agent into a mixing product obtained in the step 1, and continuously mixing; 3, curing the mixed product in the step 2 to obtain a primary blank; 4, the primary blank obtained in the step 3 is placed in a supercritical fluid environment, the pressure is maintained for 2-5 min at the pressure of 0.8-1.2 MPa, then the pressure is increased to 15-18 MPa, and the pressure is maintained for 90-100 min; and 5, after the pressure maintaining in the step 4 is completed, the pressure is released to 0 within 10-13 s, and the foaming material is obtained after cooling. The foaming material prepared by the method has good skin-friendly performance.

Description

Technical Field

[0001] The invention relates to the technical field of foaming materials, and in particular to a method for preparing a skin-friendly soft foaming material. Background Art

[0002] Ethylene-vinyl acetate copolymer (EVA) is a rubber-like thermoplastic. Compared with polyethylene, it has excellent flexibility, elasticity, stress cracking resistance, good plasticity and processability, so it is widely used. EVA has a wide range of applications. EVA foam material has the properties of softness, good elasticity, and chemical corrosion resistance. It is used in the soles and interior materials of mid-to-high-end tourist shoes, hiking shoes, slippers, and sandals.

[0003] However, although the current EVA foam material has certain soft elastic properties, its surface is still relatively hard and dense when it comes into contact with and rubs the skin, and its skin-affinity is poor. When used in some scenarios where it comes into direct contact with the skin, its comfort cannot meet the requirements. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects or problems existing in the background technology and provide a method for preparing a skin-friendly soft foaming material, which can improve the skin-friendliness of the foaming material.

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

[0006] Technical solution 1: A method for preparing a skin-friendly soft foam material, comprising the following steps: Step 1: Mixing ethylene-vinyl acetate copolymer, polyolefin elastomer, hydrogenated styrene-butadiene block copolymer and cyclohexane oil; the mass fraction of ethylene-vinyl acetate copolymer is 20-30 parts, the mass fraction of polyolefin elastomer is 12-18 parts, the mass fraction of hydrogenated styrene-butadiene block copolymer is 50-75 parts, and the mass fraction of cyclohexane oil is 1.5-2.5 parts; Step 2: Adding an auxiliary agent to the mixed product of step 1 and a cross-linking agent, and continue to mix; the mass portion of the auxiliary agent is 0.5-0.8 parts, and the mass portion of the cross-linking agent is 0.4-0.7 parts; step three: the mixed product of step two is ripened to obtain a primary embryo; step four: the primary embryo obtained in step three is placed in a supercritical fluid environment and maintained at a pressure of 0.8-1.2MPa for 2-5min, and then the pressure is increased to 15-18MPa and maintained for 90-100min; step five: after the pressure maintenance in step four is completed, the pressure is released to 0 within 10-13s, and the foaming material is obtained after cooling.

[0007] Technical solution 2 based on technical solution 1: in step 1, the mixing temperature is 110-120°C, and the mixing time is 10-15min.

[0008] Technical solution three based on technical solution one: in step two, the mixing temperature is 120-130° C., and the mixing time is 10-15 min.

[0009] Technical solution 4 based on technical solution 1: in step 3, the aging temperature is 170-180°C, and the aging time is 6-7 minutes.

[0010] Technical solution five based on technical solution one: in step four, the supercritical fluid environment is a nitrogen fluid environment.

[0011] Technical solution six based on technical solution one: the content of vinyl acetate in the ethylene-vinyl acetate copolymer is 30%-35%.

[0012] Technical Solution 7 based on Technical Solution 1: The hydrogenated styrene-butadiene block copolymer is a star-shaped block copolymer with a molecular weight of 200,000-250,000.

[0013] Technical solution eight based on technical solution one: the auxiliary agent is one or two of stearic acid and fatty acid.

[0014] Technical solution nine based on technical solution one: the cross-linking agent is one of diisopropylbenzene peroxide and 1,4-di-tert-butylperoxyisopropylbenzene.

[0015] It can be seen from the above description of the present invention that, compared with the prior art, the present invention has the following beneficial effects:

[0016] The invention provides a method for preparing a skin-friendly soft foaming material. The foaming material is based on ethylene-vinyl acetate copolymer, hydrogenated styrene-butadiene block copolymer and polyolefin elastomer, cyclohexane oil and corresponding additives and cross-linking agents are added, and the desired foaming material is obtained by supercritical fluid foaming after aging. By controlling the mass ratio of each component in the above formula and improving the preparation process, the skin-friendliness of the foaming material is greatly improved compared with conventional EVA foaming materials, and the material is soft and fatigue-resistant, and is suitable for scenes in direct contact with the skin.

[0017] Among them, in the formula of the skin-friendly soft foam material, the ratio of hydrogenated styrene-butadiene block copolymer, i.e. SEBS material, reaches a high ratio of 50-75 parts by mass, which is about 2.5 times that of ethylene-vinyl acetate copolymer, i.e. EVA material. By increasing the proportion of SEBS, the butadiene block part as the soft segment in SEBS can make the material have a soft touch, while the styrene block part as the hard segment can provide a certain rigidity, so that the material also has good shape stability, and SEBS can cooperate with EVA, and the specific ratio of the two makes the final foam material The foam material not only has a soft touch, but also has a relatively stable contact texture; wherein, the content of vinyl acetate in the added EVA can be selected in the range of 30%-35%, and VA, as a flexible segment in the EVA molecular chain, has a freer internal rotation of the intramolecular chemical bonds, and can form an irregularly curled random coil conformation; the appropriate VA mass content range can ensure the uniform distribution of the random coil conformation in the tertiary structure of the polymer, effectively reduce the crystallization ability of the ethylene segment in the polymer, and keep the polymer molecular chain as flexible as possible, thereby ensuring the softness and high elasticity of the foam material.

[0018] At the same time, polyolefin elastomer, i.e., POE material, is added to the formula, and the POE material can further improve the elasticity of the foaming material and the tensile crack resistance of the foaming material; the addition of cyclopentane oil cooperates with the aging and supercritical foaming process in the foaming material preparation method, so that the foaming can proceed normally under a relatively low supercritical fluid pressure, and the pore size of the foaming material is denser, so that the surface of the foaming material has both soft elasticity and silkiness, and the cyclopentane oil can reduce the interaction between polymer molecular chains, so that the surface of the foaming material remains smooth and maintains an appropriate friction coefficient, thereby reducing the friction of the surface of the foaming material on the skin, and does not cause poor touch due to being too smooth, thereby improving the skin-friendliness of the foaming material to the skin; in addition, the cyclopentane oil is evenly dispersed in the resin system through the mixing process, so that the cyclopentane oil can adjust the overall hardness and flexibility of the foaming material, so that the foaming material can have better elasticity and deformation recovery ability.

[0019] In addition, in step one, the mixing temperature is set to 110-120°C and the mixing time is 10-15min. Within this temperature and time range, the molecular chains of each polymer component have appropriate mobility and can interweave and entangle with each other under the action of mechanical shear force, so that the components are evenly dispersed and local agglomeration or uneven mixing is avoided, thereby ensuring the consistency and stability of material properties and laying a good foundation for subsequent steps. If the temperature is too low or the time is too short, the mixing is insufficient, which will lead to uneven material properties; if the temperature is too high or the time is too long, it may cause adverse phenomena such as polymer degradation, affecting material properties.

[0020] In step 2, the mixing temperature of 120-130°C and the mixing time of 10-15 minutes can make the additives and cross-linking agents evenly dispersed and effectively play a role. This temperature range is conducive to the full integration of the additives and the polymer matrix, promoting their uniform distribution in the material, and better playing the role of improving processing performance. The cross-linking agent can undergo a moderate cross-linking reaction with the polymer molecular chain at this temperature and time to form a stable cross-linked network structure. If the temperature and time are not properly controlled, the cross-linking reaction may be incomplete or excessive, resulting in insufficient material strength or too hard, brittle and other problems, affecting the skin-friendly soft properties and comprehensive performance.

[0021] In step 3, the aging temperature of 170-180℃ and the aging time of 6-7min help the embryo to further stabilize the structure and improve the performance. Under this aging condition, the cross-linking reaction is further improved, the arrangement of the polymer molecular chain is more regular and orderly, and the stress inside the material is relaxed, thereby improving the dimensional stability, strength and heat resistance of the material.

[0022] A star-shaped block copolymer with a molecular weight of 200,000-250,000 is used as the hydrogenated styrene-butadiene block copolymer. The special molecular structure of the star-shaped block copolymer has multiple arms, which can serve as nucleation points during the foaming process to promote the uniform formation and stability of the bubbles. At the same time, its molecular weight affects the entanglement and interaction of the molecular chains, and thus affects the strength and elasticity of the material. The appropriate molecular weight range can ensure a good foaming effect while giving the material the mechanical properties required for skin-friendly softness. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are preferred embodiments of the present invention and should not be regarded as excluding other embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the claims and description of the present invention, if the terms "include", "have" and their variations are used, they are intended to mean "including but not limited to".

[0025] The present invention provides a method for preparing a skin-friendly soft foam material, and the method for preparing the skin-friendly soft foam material comprises the following steps:

[0026] Step 1: mixing ethylene-vinyl acetate copolymer, polyolefin elastomer, hydrogenated styrene-butadiene block copolymer and cyclohexane oil; the mass portion of ethylene-vinyl acetate copolymer is 20-30 parts, the mass portion of polyolefin elastomer is 12-18 parts, the mass portion of hydrogenated styrene-butadiene block copolymer is 50-75 parts, and the mass portion of cyclohexane oil is 1.5-2.5 parts;

[0027] Step 2: Adding an auxiliary agent and a cross-linking agent to the mixed product of step 1, and continuing to mix; the weight portion of the auxiliary agent is 0.5-0.8 parts, and the weight portion of the cross-linking agent is 0.4-0.7 parts;

[0028] Step 3: Ripening the mixed product of step 2 to obtain a primary embryo;

[0029] Step 4: Place the embryo obtained in step 3 into a supercritical fluid environment and maintain the pressure at 0.8-1.2 MPa for 2-5 minutes, then increase the pressure to 15-18 MPa and maintain the pressure for 90-100 minutes;

[0030] Step 5: After the pressure maintenance in step 4 is completed, the pressure is released to 0 within 10-13 seconds, and the foaming material is obtained after cooling.

[0031] In step 1, the mixing temperature is 110-120° C. and the mixing time is 10-15 min.

[0032] In step 2, the mixing temperature is 120-130° C. and the mixing time is 10-15 min.

[0033] In step 3, the aging temperature is 170-180° C. and the aging time is 6-7 minutes.

[0034] In step 4, the supercritical fluid environment is a nitrogen fluid environment.

[0035] In the ethylene-vinyl acetate copolymer, the content of vinyl acetate is 30%-35%, and the EVA brand can be selected from brands such as UE629 of Taiwan Taiju, Japan Tosoh EVA633, EVA750, and US DuPont 150.

[0036] The hydrogenated styrene-butadiene block copolymer is a star-shaped block copolymer with a molecular weight of 200,000-250,000, and the SEBS brand is YH602T from Baling Petrochemical.

[0037] The auxiliary agent is one or both of stearic acid and fatty acid.

[0038] The cross-linking agent is one of dicumyl peroxide and 1,4-di-tert-butyl peroxycumene.

[0039] Among them, in the formula of the skin-friendly soft foam material, the ratio of hydrogenated styrene-butadiene block copolymer, i.e. SEBS material, reaches a high ratio of 50-75 parts by mass, which is about 2.5 times that of ethylene-vinyl acetate copolymer, i.e. EVA material. By increasing the proportion of SEBS, the butadiene block part as the soft segment in SEBS can make the material have a soft touch, while the styrene block part as the hard segment can provide a certain rigidity, so that the material also has good shape stability, and SEBS can cooperate with EVA, and the specific ratio of the two makes the final foam material The foam material not only has a soft touch, but also has a relatively stable contact texture; wherein, the content of vinyl acetate in the added EVA can be selected in the range of 30%-35%, and VA, as a flexible segment in the EVA molecular chain, has a freer internal rotation of the intramolecular chemical bonds, and can form an irregularly curled random coil conformation; the appropriate VA mass content range can ensure the uniform distribution of the random coil conformation in the tertiary structure of the polymer, effectively reduce the crystallization ability of the ethylene segment in the polymer, and keep the polymer molecular chain as flexible as possible, thereby ensuring the softness and high elasticity of the foam material.

[0040] At the same time, polyolefin elastomer, i.e., POE material, is added to the formula, and the POE material can further improve the elasticity of the foaming material and the tensile crack resistance of the foaming material; the addition of cyclopentane oil is coordinated with the aging and supercritical foaming process in the foaming material preparation method, so that the foaming can proceed normally under a relatively low supercritical fluid pressure, and the pore size of the foaming material is denser, so that the surface of the foaming material has both soft elasticity and silkiness, and the cyclopentane oil can reduce the force between polymer molecular chains, so that the surface of the foaming material is smoother, thereby reducing the friction of the foaming material surface on the skin and improving the skin-friendliness of the foaming material to the skin; in addition, the cyclopentane oil is evenly dispersed in the resin system through the mixing process, so that the cyclopentane oil can adjust the overall hardness and flexibility of the foaming material, so that the foaming material can have better elasticity and deformation recovery ability.

[0041] In addition, in step one, the mixing temperature is set to 110-120°C and the mixing time is 10-15min. Within this temperature and time range, the molecular chains of each polymer component have appropriate mobility and can interweave and entangle with each other under the action of mechanical shear force, so that the components are evenly dispersed and local agglomeration or uneven mixing is avoided, thereby ensuring the consistency and stability of material properties and laying a good foundation for subsequent steps. If the temperature is too low or the time is too short, the mixing is insufficient, which will lead to uneven material properties; if the temperature is too high or the time is too long, it may cause adverse phenomena such as polymer degradation, affecting material properties.

[0042] In step 2, the mixing temperature of 120-130°C and the mixing time of 10-15 minutes can make the additives and cross-linking agents evenly dispersed and effectively play a role. This temperature range is conducive to the full integration of the additives and the polymer matrix, promoting their uniform distribution in the material, and better playing the role of improving processing performance. The cross-linking agent can undergo a moderate cross-linking reaction with the polymer molecular chain at this temperature and time to form a stable cross-linked network structure. If the temperature and time are not properly controlled, the cross-linking reaction may be incomplete or excessive, resulting in insufficient material strength or too hard, brittle and other problems, affecting the skin-friendly soft properties and comprehensive performance.

[0043] In step 3, the aging temperature of 170-180℃ and the aging time of 6-7min help the embryo to further stabilize the structure and improve the performance. Under this aging condition, the cross-linking reaction is further improved, the arrangement of the polymer molecular chain is more regular and orderly, and the stress inside the material is relaxed, thereby improving the dimensional stability, strength and heat resistance of the material.

[0044] A star-shaped block copolymer with a molecular weight of 200,000-250,000 is used as the hydrogenated styrene-butadiene block copolymer. The special molecular structure of the star-shaped block copolymer has multiple arms, which can serve as nucleation points during the foaming process to promote the uniform formation and stability of the bubbles. At the same time, its molecular weight affects the entanglement and interaction of the molecular chains, and thus affects the strength and elasticity of the material. The appropriate molecular weight range can ensure a good foaming effect while giving the material the mechanical properties required for skin-friendly softness.

[0045] In the preparation method of the skin-friendly soft foaming material provided by the present invention, ethylene-vinyl acetate copolymer, hydrogenated styrene-butadiene block copolymer and polyolefin elastomer are used as the basis, cyclohexane oil and corresponding additives and cross-linking agents are added, and the desired foaming material is obtained by supercritical fluid foaming after aging. By controlling the mass ratio of each component in the above formula and improving the preparation process, the skin-friendliness of the foaming material is greatly improved compared with the conventional EVA foaming material, and the material is soft and suitable for scenes in direct contact with the skin.

[0046] In order to further illustrate the technical effect of the method for preparing the skin-friendly soft foaming material provided by the present invention, the present invention provides the following examples and comparative examples.

[0047] Example 1

[0048] The preparation method of the skin-friendly soft foaming material provided in Example 1 comprises the following steps:

[0049] Step 1: mixing ethylene-vinyl acetate copolymer, polyolefin elastomer, hydrogenated styrene-butadiene block copolymer and cyclohexane oil; the mass parts of ethylene-vinyl acetate copolymer are 20 parts, the mass parts of polyolefin elastomer are 12 parts, the mass parts of hydrogenated styrene-butadiene block copolymer are 50 parts, and the mass parts of cyclohexane oil are 1.5 parts;

[0050] Step 2: Adding an auxiliary agent and a cross-linking agent to the mixed product of step 1, and continuing to mix; the mass portion of the auxiliary agent is 0.5 parts, and the mass portion of the cross-linking agent is 0.4 parts;

[0051] Step 3: Ripening the mixed product of step 2 to obtain a primary embryo;

[0052] Step 4: Place the embryo obtained in step 3 into a supercritical fluid environment and maintain the pressure at 0.8 MPa for 2 minutes, then increase the pressure to 15 MPa and maintain the pressure for 90 minutes;

[0053] Step 5: After the pressure maintenance in step 4 is completed, the pressure is released to 0 within 10 seconds, and the foaming material is obtained after cooling.

[0054] Wherein, in step one, the mixing temperature is 110°C and the mixing time is 10 minutes. In step two, the mixing temperature is 120°C and the mixing time is 10 minutes. In step three, the aging temperature is 170°C and the aging time is 6 minutes. In step four, the supercritical fluid environment is a nitrogen fluid environment. In the ethylene-vinyl acetate copolymer, the content of vinyl acetate is 30%. The hydrogenated styrene-butadiene block copolymer is a star-shaped block copolymer with a molecular weight of 200,000. The auxiliary agent is stearic acid. The cross-linking agent is diisopropylbenzene peroxide.

[0055] Example 2

[0056] Step 1: mixing ethylene-vinyl acetate copolymer, polyolefin elastomer, hydrogenated styrene-butadiene block copolymer and cyclohexane oil; the mass parts of ethylene-vinyl acetate copolymer are 25 parts, the mass parts of polyolefin elastomer are 25 parts, the mass parts of hydrogenated styrene-butadiene block copolymer are 60 parts, and the mass parts of cyclohexane oil are 2 parts;

[0057] Step 2: Adding an auxiliary agent and a cross-linking agent to the mixed product of step 1, and continuing to mix; the mass portion of the auxiliary agent is 0.6 parts, and the mass portion of the cross-linking agent is 0.6 parts;

[0058] Step 3: Ripening the mixed product of step 2 to obtain a primary embryo;

[0059] Step 4: placing the embryo obtained in step 3 into a supercritical fluid environment and maintaining the pressure at 1 MPa for 5 minutes, then increasing the pressure to 18 MPa and maintaining the pressure for 100 minutes;

[0060] Step 5: After the pressure maintenance in step 4 is completed, the pressure is released to 0 within 12 seconds, and the foaming material is obtained after cooling.

[0061] Wherein, in step one, the mixing temperature is 120°C and the mixing time is 15 minutes. In step two, the mixing temperature is 130°C and the mixing time is 15 minutes. In step three, the aging temperature is 180°C and the aging time is 7 minutes. In step four, the supercritical fluid environment is a nitrogen fluid environment. In the ethylene-vinyl acetate copolymer, the content of vinyl acetate is 33%. The hydrogenated styrene-butadiene block copolymer is a star-shaped block copolymer with a molecular weight of 220,000. The auxiliary agent is stearic acid. The cross-linking agent is diisopropylbenzene peroxide.

[0062] Example 3

[0063] Step 1: mixing ethylene-vinyl acetate copolymer, polyolefin elastomer, hydrogenated styrene-butadiene block copolymer and cyclohexane oil; the mass parts of ethylene-vinyl acetate copolymer are 30 parts, the mass parts of polyolefin elastomer are 18 parts, the mass parts of hydrogenated styrene-butadiene block copolymer are 75 parts, and the mass parts of cyclohexane oil are 2.5 parts;

[0064] Step 2: Adding an auxiliary agent and a cross-linking agent to the mixed product of step 1, and continuing to mix; the mass portion of the auxiliary agent is 0.8 parts, and the mass portion of the cross-linking agent is 0.7 parts;

[0065] Step 3: Ripening the mixed product of step 2 to obtain a primary embryo;

[0066] Step 4: placing the embryo obtained in step 3 into a supercritical fluid environment and maintaining the pressure at 1.2 MPa for 5 minutes, then increasing the pressure to 18 MPa and maintaining the pressure for 100 minutes;

[0067] Step 5: After the pressure maintenance in step 4 is completed, the pressure is released to 0 within 13 seconds, and the foamed material is obtained after cooling.

[0068] Wherein, in step one, the mixing temperature is 120°C and the mixing time is 15 minutes. In step two, the mixing temperature is 130°C and the mixing time is 15 minutes. In step three, the aging temperature is 180°C and the aging time is 7 minutes. In step four, the supercritical fluid environment is a nitrogen fluid environment. In the ethylene-vinyl acetate copolymer, the content of vinyl acetate is 35%. The hydrogenated styrene-butadiene block copolymer is a star-shaped block copolymer with a molecular weight of 250,000. The auxiliary agent is stearic acid. The cross-linking agent is diisopropylbenzene peroxide.

[0069] Comparative Example 1

[0070] Based on Example 2, the difference from Example 2 is that the mass parts of SEBS added is 25 parts.

[0071] Comparative Example 2

[0072] Based on Example 2, the difference from Example 2 is that the mass parts of SEBS added is 30 parts, and the mass parts of EVA is 40 parts.

[0073] Comparative Example 3

[0074] Based on Example 2, the difference from Example 2 is that no cyclohexane oil is added.

[0075] The physical properties and appearance of the above examples 1-3 and comparative examples 1-3 were tested, and the test results are as follows:

[0076]

[0077] It is easy to know from the above test results that the amount of SEBS is greatly reduced in Comparative Example 1, and the amount of SEBS is roughly equivalent to the amount of EVA, resulting in poor skin affinity of the surface of the foamed material; the amount of EVA is increased in Comparative Example 2, and the surface skin affinity of the foamed material is not improved; in Comparative Example 3, no cyclopentane oil is added, resulting in a sharp decrease in the skin affinity of the foamed material. Through the above comparative examples, in the preparation method of the skin-friendly soft foamed material provided by the present invention, by increasing the amount of SEBS and adding an appropriate amount of cyclopentane oil, the skin affinity of the foamed material is effectively improved, and the material is soft and fatigue-resistant, suitable for scenes in direct contact with the skin.

[0078] The description of the above specification and embodiments is used to explain the protection scope of the present invention, but does not constitute a limitation on the protection scope of the present invention. Through the enlightenment of the present invention or the above embodiments, ordinary technicians in this field can obtain modifications, equivalent substitutions or other improvements to the embodiments of the present invention or part of the technical features thereof through logical analysis, reasoning or limited experiments, which should be included in the protection scope of the present invention.

Claims

1. A method for preparing a skin-friendly soft foaming material, characterized in that: The following steps are involved: Step 1: mixing ethylene-vinyl acetate copolymer, polyolefin elastomer, hydrogenated styrene-butadiene block copolymer and cyclohexane oil; the mass portion of ethylene-vinyl acetate copolymer is 20-30 parts, the mass portion of polyolefin elastomer is 12-18 parts, the mass portion of hydrogenated styrene-butadiene block copolymer is 50-75 parts, and the mass portion of cyclohexane oil is 1.5-2.5 parts; Step 2: Adding an auxiliary agent and a cross-linking agent to the mixed product of step 1, and continuing to mix; the weight portion of the auxiliary agent is 0.5-0.8 parts, and the weight portion of the cross-linking agent is 0.4-0.7 parts; Step 3: Ripening the mixed product of step 2 to obtain a primary embryo; Step 4: Place the embryo obtained in step 3 into a supercritical fluid environment and maintain the pressure at 0.8-1.2 MPa for 2-5 minutes, then increase the pressure to 15-18 MPa and maintain the pressure for 90-100 minutes; Step 5: After the pressure maintenance in step 4 is completed, the pressure is released to 0 within 10-13 seconds, and the foaming material is obtained after cooling.

2. The method for preparing a skin-friendly soft foaming material according to claim 1, characterized in that: In step 1, the mixing temperature is 110-120° C. and the mixing time is 10-15 min.

3. The method for preparing a skin-friendly soft foaming material according to claim 1, characterized in that: In step 2, the mixing temperature is 120-130° C. and the mixing time is 10-15 min.

4. The method for preparing a skin-friendly soft foaming material according to claim 1, characterized in that: In step 3, the aging temperature is 170-180° C. and the aging time is 6-7 minutes.

5. The method for preparing a skin-friendly soft foaming material according to claim 1, characterized in that: In step 4, the supercritical fluid environment is a nitrogen fluid environment.

6. The method for preparing a skin-friendly soft foaming material according to claim 1, characterized in that: The content of vinyl acetate in the ethylene-vinyl acetate copolymer is 30%-35%.

7. The method for preparing a skin-friendly soft foaming material according to claim 1, characterized in that: The hydrogenated styrene-butadiene block copolymer is a star-shaped block copolymer with a molecular weight of 200,000 to 250,000.

8. The method for preparing a skin-friendly soft foaming material according to claim 1, characterized in that: The auxiliary agent is one or both of stearic acid and fatty acid.

9. The method for preparing a skin-friendly soft foaming material according to claim 1, characterized in that: The cross-linking agent is one of dicumyl peroxide and 1,4-di-tert-butyl peroxycumene.

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