Light high-elastic wear-resistant foaming material for shoes

Abstract

The invention provides a lightweight high-elastic wear-resistant foam material for shoes, and relates to the technical field of polymer foam materials. The material comprises the following components in parts by weight: a polyamide elastomer, polyethylene-vinyl acetate resin, an ethylene-octylene random copolymer, a hydrogenated styrene-butadiene block copolymer, ionomer resin, a compatible agent SEBS-g-MAH, a wear-resistant agent, stearic acid, zinc stearate, zinc oxide, a cross-linking agent, a cross-linking assistant, a foaming agent and a filler. By adding the ionomer resin, the physical crosslinking effect among the components is enhanced, the melt strength is improved, and gas can be well locked in the melt; the ionomer resin has a special self-repairing function, so that the wear and scratch resistance is greatly improved, and compared with a shoe material prepared by a traditional EVA chemical foaming process, the shoe material has better properties of light weight, high elasticity, low wear and low compression permanent deformation rate on the basis of ensuring hardness and tear strength.

Description

Technical Field

[0001] The invention relates to the technical field of polymer foaming materials, in particular to a lightweight, highly elastic and wear-resistant foaming material for shoes. Background Art

[0002] In recent years, people's awareness and habits of sports and fitness have been increasing, and there have been more diversified demands for the use of related equipment, such as balls, protective gear, accessories such as clothing, shoes, etc.; as people's living standards improve, users are more receptive to the use of higher quality shoes to meet their various performance requirements at different sports levels, such as the lightweight of running shoes for middle and long distance jogging, the comfort of the foot, the elastic feedback of the foam midsole at high step frequency, and the different degrees of wear requirements for various possible road surfaces.

[0003] The sole foaming materials produced by traditional soft elastomers such as EVA, POE and SEBS can no longer meet the higher performance requirements of consumers. Therefore, the supercritical foaming technology used in shoe materials in recent years has developed many new materials for use in shoe materials; for example, high-performance thermoplastic elastomers such as polyamide elastomer (PEBA), polyurethane elastomer (TPU), polyether ester elastomer (TPEE) are used to prepare lightweight and highly elastic high-performance sports shoe midsoles using supercritical foaming process technology, which occupy the main sales focus of high-end sports shoes of major domestic and foreign brands; and this type of thermoplastic elastomer contains hard segments and soft segments with different molecular structures in the polymer chain structure. Under room temperature application, the material is between the glass transition temperatures of the soft and hard segments, and the hard segment micro-region is in a glassy state, which serves as a physical cross-linking point to provide the thermoplastic elastomer with a certain physical strength, while the soft segment region is in a highly elastic state, providing the material with good ductility and elasticity.

[0004] In recent years, domestic and foreign sports brands have begun to use polyamide elastomer materials and use supercritical foaming technology to produce high-performance midsoles. The main feature is that it can achieve 75-80% or even higher impact rebound performance at a lighter weight, and it has quickly become a hot emerging material in the industry; however, the use of supercritical foaming technology has higher undesirable losses compared to the traditional in-mold foaming process, that is, higher costs; in terms of physical properties, the rebound of the midsole foam material produced by traditional chemical foaming can reach more than 65%, but the wear resistance and durability are poor. For this reason, we propose a lightweight, highly elastic and wear-resistant foam material for shoes to solve the above problems. Summary of the invention

[0005] The problem to be solved by the present invention is that it is difficult for the sole material prepared by chemical foaming process to have the characteristics of light weight, high elasticity, high wear resistance and the like.

[0006] In order to solve the above technical problems, the present invention provides a lightweight, highly elastic and wear-resistant foam material for shoes, wherein the foam material comprises the following components in parts by weight:

[0007] Polyamide elastomer: 5-20 parts;

[0008] Polyethylene-vinyl acetate resin: 20-35 parts;

[0009] Ethylene-octene random copolymer: 10-25 parts;

[0010] Hydrogenated styrene butadiene segment copolymer: 10-30 parts;

[0011] Ionomer resin: 0-5 parts;

[0012] Compatibility agent SEBS-g-MAH: 0-6 parts;

[0013] Wear-resistant agent: 0-5 parts;

[0014] Stearic acid: 0.1-0.5 parts;

[0015] Zinc stearate: 0.1-0.5 parts;

[0016] Zinc oxide: 1-1.8 parts;

[0017] Cross-linking agent: 0.1-0.55 parts;

[0018] Cross-linking aid: 0-0.1 parts;

[0019] Foaming agent: 1-3.5 parts;

[0020] Filler: 0-8 parts;

[0021] Preferably, the sum of the weight parts of the polyamide elastomer, polyethylene-vinyl acetate resin, ethylene-octene random copolymer, hydrogenated styrene butadiene segment copolymer, and ionomer resin is 100 parts.

[0022] Preferably, the compatibilizer is at least one or more of maleic anhydride grafted ethylene-octene block copolymer, maleic anhydride grafted ethylene-octene random copolymer, maleic anhydride grafted hydrogenated styrene butadiene block copolymer, and maleic anhydride grafted ethylene-vinyl acetate resin.

[0023] Preferably, the foaming agent is at least one or more of azodicarbonamide, N,N-dinitrosopentamethylenetetramine, 4,4'-oxybisbenzenesulfonylhydrazide, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate and ammonium nitrite.

[0024] Preferably, the cross-linking agent is at least one or two of dicumyl peroxide and 1,4-di-tert-butyl peroxycumene.

[0025] Preferably, the crosslinking aid is at least one or more of triallyl isocyanurate, trimethacrylate, and trimethylolpropane triacrylate.

[0026] Preferably, the filler is at least one or more of talc, titanium dioxide, calcium carbonate, white carbon black and montmorillonite.

[0027] Preferably, the foaming material further comprises an antioxidant, an anti-wear agent, a coupling agent, and a pigment.

[0028] Technical effects and advantages of the present invention:

[0029] 1. The present invention strengthens the physical cross-linking effect between the components by adding ionomer resin, improves the melt strength, and can lock the gas therein well; and because the ionomer resin has a special self-repairing function, it greatly improves the wear and scratch resistance, making the foamed midsole material have higher durability.

[0030] 2. The compatibilizer added in the present invention can improve the dispersibility of hydrogenated styrene butadiene block copolymer and polyamide elastomer in the formula, so that the impact rebound, wear resistance, mechanical strength, compression deformation and delamination tear strength are significantly improved, thereby improving the strength of the foamed midsole.

[0031] 3. The present invention enables the traditional chemical foaming formula to comprehensively improve physical properties by adding PEBAX material. The hard segment (amide) in its molecular structure plays a role in backbone reinforcement, which can make the formula lightweight while improving physical properties. The soft segment (polyether) in the molecular structure can greatly improve the impact resilience and compression permanent deformation rate of the foam.

[0032] 4. Compared with the shoe materials made by the traditional EVA chemical foaming process, the shoe foaming material provided by the present invention has a lower average density, higher tensile strength, higher rebound rate, and lower compression permanent deformation rate on the basis of ensuring hardness and tear strength, and has the better performance of lighter weight, high elasticity, low wear, and low compression permanent deformation rate. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with implementation examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] Example 1

[0035] The present invention provides a lightweight, highly elastic and wear-resistant foam material for shoes. The foam material comprises the following components in parts by weight:

[0036] Polyamide elastomer (PEBA) 55R53: 5 parts;

[0037] Polyethylene-vinyl acetate resin EVA7470: 35 parts;

[0038] Ethylene-octene random copolymer (POE) POE8003: 5 parts;

[0039] Ethylene-octene random copolymer (POE) POE8180: 20 parts;

[0040] Hydrogenated styrene butadiene segment copolymer N533: 30 parts;

[0041] Ionomer resin: 5 parts;

[0042] Compatibility agent SEBS-g-MAH: 6 parts;

[0043] Wear-resistant agent: 5 parts;

[0044] Stearic acid: 0.5 parts;

[0045] Zinc stearate: 0.5 parts;

[0046] Zinc oxide: 1.8 parts;

[0047] Cross-linking agent (BIPB): 0.55 parts;

[0048] Cross-linking aid (TAIC): 0.1 part;

[0049] Foaming agent (AC3000): 3.5 parts;

[0050] Titanium dioxide (R103): 5 parts;

[0051] Filler (talc): 3 parts.

[0052] The specific preparation method comprises the following steps:

[0053] S1: For the proportion of foaming material components, ethylene-octene random copolymer (POE), hydrogenated styrene butadiene block copolymer (SEBS), polyethylene-vinyl acetate resin (EVA), ionomer resin (Surlyn) and polyamide elastomer (PEBA) and compatibility agent are added into an internal mixer for blending, the blending time is 10-12 minutes, and the blending setting temperature is 100-120°C;

[0054] S2: Put the cross-linking agent, auxiliary cross-linking agent, stearic acid, zinc stearate, zinc oxide, foaming agent and filler into an internal mixer, and continue to mix at 110-120° C. for 2-3 minutes to form a mixture;

[0055] S3: Transfer the mixture in S2 to an open mixer to make thin sheets, pass through once, mix for 3 minutes, pass through three times, mix for 1 minute;

[0056] S4, pouring the shoe material copolymer particles in S3 into a foaming mold for foaming, the foaming temperature is 170-175°C, the foaming time is 600-800 seconds, and a rough sole blank is obtained. After the rough sole blank is cooled, it is polished and peeled, and then placed in a molding mold for heating and cooling and shaping. The heating temperature is 170-175°C, the heating time is 450-650 seconds, the cooling is 450-650 seconds, the shaping pressure is 8-15MPa, the foaming ratio is 1.70-1.75, and the sole material is obtained after shaping.

[0057] Example 2

[0058] The present invention provides a lightweight, highly elastic and wear-resistant foam material for shoes. The foam material comprises the following components in parts by weight:

[0059] Polyamide elastomer (PEBA) 55R53: 10 parts;

[0060] Polyethylene-vinyl acetate resin EVA7470: 30 parts;

[0061] Ethylene-octene random copolymer (POE) POE8003: 5 parts;

[0062] Ethylene-octene random copolymer (POE) POE8180: 20 parts;

[0063] Hydrogenated styrene butadiene segment copolymer N533: 30 parts;

[0064] Ionomer resin: 5 parts;

[0065] Compatibility agent SEBS-g-MAH: 6 parts;

[0066] Wear-resistant agent: 5 parts;

[0067] Stearic acid: 0.5 parts;

[0068] Zinc stearate: 0.5 parts;

[0069] Zinc oxide: 1.8 parts;

[0070] Cross-linking agent (BIPB): 0.55 parts;

[0071] Cross-linking aid (TAIC): 0.1 part;

[0072] Foaming agent (AC3000): 3.5 parts;

[0073] Titanium dioxide (R103): 5 parts;

[0074] Filler (talc): 3 parts.

[0075] The specific preparation method comprises the following steps:

[0076] S1: For the proportion of foaming material components, ethylene-octene random copolymer (POE), hydrogenated styrene butadiene block copolymer (SEBS), polyethylene-vinyl acetate resin (EVA), ionomer resin (Surlyn) and polyamide elastomer (PEBA) and compatibility agent are added into an internal mixer for blending, the blending time is 10-12 minutes, and the blending setting temperature is 100-120°C;

[0077] S2: Put the cross-linking agent, auxiliary cross-linking agent, stearic acid, zinc stearate, zinc oxide, foaming agent and filler into an internal mixer, and continue to mix at 110-120° C. for 2-3 minutes to form a mixture;

[0078] S3: Transfer the mixture in S2 to an open mixer to make thin sheets, pass through once, mix for 3 minutes, pass through three times, mix for 1 minute;

[0079] S4: sending the flake material in S3 to a granulator for granulation to obtain a shoe material copolymer;

[0080] S5: pouring the shoe material copolymer particles in S4 into the barrel of an injection molding machine, with a molding temperature of 170-175° C., a molding time of 400-450 seconds, and a foaming ratio of 1.50-1.65 to obtain a shoe sole material.

[0081] Example 3

[0082] The present invention provides a lightweight, highly elastic and wear-resistant foam material for shoes. The foam material comprises the following components in parts by weight:

[0083] Polyamide elastomer (PEBA) 55R53: 20 parts;

[0084] Polyethylene-vinyl acetate resin EVA7470: 20 parts;

[0085] Ethylene-octene random copolymer (POE) POE8003: 5 parts;

[0086] Ethylene-octene random copolymer (POE) POE8180: 20 parts;

[0087] Hydrogenated styrene butadiene segment copolymer N533: 30 parts;

[0088] Ionomer resin: 5 parts;

[0089] Compatibility agent SEBS-g-MAH: 6 parts;

[0090] Wear-resistant agent: 5 parts;

[0091] Stearic acid: 0.5 parts;

[0092] Zinc stearate: 0.5 parts;

[0093] Zinc oxide: 1.8 parts;

[0094] Cross-linking agent (BIPB): 0.55 parts;

[0095] Cross-linking aid (TAIC): 0.1 part;

[0096] Foaming agent (AC3000): 3.5 parts;

[0097] Titanium dioxide (R103): 5 parts;

[0098] Filler (talc): 3 parts.

[0099] The specific preparation method comprises the following steps:

[0100] S1: For the proportion of foaming material components, ethylene-octene random copolymer (POE), hydrogenated styrene butadiene block copolymer (SEBS), polyethylene-vinyl acetate resin (EVA), ionomer resin (Surlyn) and polyamide elastomer (PEBA) and compatibility agent are added into an internal mixer for blending, the blending time is 10-12 minutes, and the blending setting temperature is 100-120°C;

[0101] S2: Put the cross-linking agent, auxiliary cross-linking agent, stearic acid, zinc stearate, zinc oxide, foaming agent and filler into an internal mixer, and continue to mix at 110-120° C. for 2-3 minutes to form a mixture;

[0102] S3: Transfer the mixture in S2 to an open mixer to make thin sheets, pass through once, mix for 3 minutes, pass through three times, mix for 1 minute;

[0103] S4, pouring the shoe material copolymer particles in S3 into a foaming mold for foaming, the foaming temperature is 170-175°C, the foaming time is 600-800 seconds, and a rough sole blank is obtained. After the rough sole blank is cooled, it is polished and peeled, and then placed in a molding mold for heating and cooling and shaping. The heating temperature is 170-175°C, the heating time is 450-650 seconds, the cooling is 450-650 seconds, the shaping pressure is 8-15MPa, the foaming ratio is 1.70-1.75, and the sole material is obtained after shaping.

[0104] Table 1: Component details of each embodiment of lightweight, highly elastic, compression-resistant foam material for shoes

[0105]

[0106] As shown in Table 1, Comparative Example 1 does not add ionomer resin to Comparative Example 1; Comparative Example 2 does not add compatibility agent to Comparative Example 2; Comparative Example 3 does not add main base material polyamide elastomer to Comparative Example 3; The sole samples prepared according to the chemical foaming preparation method of each embodiment are subjected to tensile strength, 180 degree tear strength, hardness, density, impact rebound rate, compression permanent deformation rate and other performance tests, and the test results are shown in Table 2;

[0107] Table 2: Test results

[0108]

[0109] As can be seen from the table, the density of Examples 1-3 is 0.155 g / cm 3 -0.173g / cm 3 , the maximum rebound can reach 69%, the tensile strength is above 3.0MPa, the impact rebound rate is above 65%, the minimum compression permanent deformation can reach 36%, and the minimum national standard wear can be less than 9.0.

[0110] Comparative Example 1 Compared with Example 1, it can be found that the presence of the ionomer resin strengthens the physical cross-linking effect between the components, improves the melt strength and can lock the gas therein well; and because the ionomer resin has a special self-repairing function, the wear and scratch resistance of Comparative Example 1 is greatly improved, so that the foamed midsole material has higher durability.

[0111] Comparative Example 2 Compared with Example 2, it can be found that in the presence of a compatibilizer, the dispersibility of hydrogenated styrene butadiene block copolymer and polyamide elastomer in the formula is improved, so that the impact rebound, abrasion resistance, mechanical strength, compression deformation and delamination tear strength are all significantly improved.

[0112] Comparative Example 3 Compared with Example 3, it can be found that the introduction of PEBAX material enables the traditional chemical foaming formula to comprehensively improve the physical properties. Mainly, the hard segment (amide) in its molecular structure plays a role in backbone reinforcement, which can make the formula lightweight while improving physical properties. The soft segment (polyether) in the molecular structure can greatly improve the impact resilience and compression permanent deformation rate of the foam.

[0113] Compared with the shoe material made by the traditional EVA chemical foaming process, the shoe sole material of the present invention has lower average density, higher tensile strength, higher rebound rate, and lower compression permanent deformation rate on the basis of ensuring hardness and tear strength, and has the better performance of lighter weight, high elasticity, low wear, and low compression permanent deformation rate.

[0114] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A lightweight, highly elastic, wear-resistant foam material for shoes, characterized by: The foaming material comprises the following components in parts by weight: Polyamide elastomer: 5-20 parts; Polyethylene-vinyl acetate resin: 20-35 parts; Ethylene-octene random copolymer: 10-25 parts; Hydrogenated styrene butadiene segment copolymer: 10-30 parts; Ionomer resin: 0-5 parts; Compatibility agent SEBS-g-MAH: 0-6 parts; Wear-resistant agent: 0-5 parts; Stearic acid: 0.1-0.5 parts; Zinc stearate: 0.1-0.5 parts; Zinc oxide: 1-1.8 parts; Cross-linking agent: 0.1-0.55 parts; Cross-linking aid: 0-0.1 parts; Foaming agent: 1-3.5 parts; Filler: 0-8 parts.

2. A lightweight, highly elastic, wear-resistant foam material for shoes according to claim 1, characterized in that: The total weight of the polyamide elastomer, polyethylene-vinyl acetate resin, ethylene-octene random copolymer, hydrogenated styrene butadiene segment copolymer and ionomer resin is 100 parts.

3. The lightweight, highly elastic and wear-resistant foam material for shoes according to claim 1, characterized in that: The compatibilizer is at least one or more of maleic anhydride grafted ethylene-octene block copolymer, maleic anhydride grafted ethylene-octene random copolymer, maleic anhydride grafted hydrogenated styrene butadiene block copolymer, and maleic anhydride grafted ethylene-vinyl acetate resin.

4. The lightweight, highly elastic, wear-resistant foam material for shoes according to claim 1, characterized in that: The foaming agent is at least one or more of azodicarbonamide, N,N-dinitrosopentamethylenetetramine, 4,4'-oxybisbenzenesulfonylhydrazide, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate and ammonium nitrite.

5. The lightweight, highly elastic and wear-resistant foam material for shoes according to claim 1, characterized in that: The cross-linking agent is at least one or two of dicumyl peroxide and 1,4-di-tert-butyl peroxycumene.

6. The lightweight, highly elastic, wear-resistant foam material for shoes according to claim 1, characterized in that: The cross-linking auxiliary agent is at least one or more of triallyl isocyanurate, trimethacrylate, and trimethylolpropane triacrylate.

7. The lightweight, highly elastic and wear-resistant foam material for shoes according to claim 1, characterized in that: The filler is at least one or more of talc, titanium dioxide, calcium carbonate, white carbon black and montmorillonite.

8. The lightweight, highly elastic, wear-resistant foam material for shoes according to claim 1, characterized in that: The foaming material also includes antioxidants, wear-resistant agents, coupling agents and pigments.

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