TPE foamed material, preparation method thereof and composite yoga mat

Abstract

The application belongs to the technical field of yoga mats, and discloses a TPE foaming material, a preparation method thereof and a composite yoga mat, the TPE foaming material is prepared from the following raw materials in parts by weight: SEBS 40-60 parts, inorganic filler 20-40 parts, processing oil 12-15 parts, compatibilizer 8-15 parts, foaming agent 1.5-3 parts, zinc oxide 0.5-1 part and stearic acid 0.2-0.8 part; and the compatibilizer is a mixture of SEBS-g-MAH and POE-g-GMA. By compounding SEBS-g-MAH and POE-g-GMA, the TPE foaming material and the rubber bottom layer are combined by hydrogen bonds and covalent bonds after hot pressing, so that the problem of low bonding strength between the foaming layer and the rubber layer and easy delamination of the traditional TPE composite mat due to the large polarity difference between the TPE material and the rubber material can be completely solved.

Description

Technical Field

[0001] This invention relates to the field of yoga mat technology, and in particular to a TPE foam material, its preparation method, and a composite yoga mat. Background Technology

[0002] TPE yoga mats are fitness mats made from thermoplastic elastomers through extrusion foaming. The material does not contain plasticizers or other harmful substances and is lightweight, highly resilient, flexible, and recyclable. To ensure a non-slip surface, TPE yoga mats are often used in combination with a natural rubber backing.

[0003] However, TPE materials and rubber have significant differences in polarity, resulting in poor compatibility. Traditional processes rely solely on direct hot-pressing with a single layer of adhesive, which fails to adequately wet the surfaces of both materials. This leads to the formation of a weak boundary layer at the interface, ultimately resulting in low bond strength and a tendency for delamination. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a TPE foam material, its preparation method and a composite yoga mat, aiming to solve the technical problem that TPE composite yoga mats are prone to delamination and peeling due to the large difference in polarity between TPE material and rubber material.

[0005] The first aspect of this invention provides a TPE foam material, the raw materials for which, by weight, are comprised: The composition includes 40-60 parts SEBS, 20-40 parts inorganic filler, 12-15 parts processing oil, 8-15 parts compatibilizer, 1.5-3 parts foaming agent, 0.5-1 part zinc oxide, and 0.2-0.8 parts stearic acid; the compatibilizer is a mixture of SEBS-g-MAH and POE-g-GMA.

[0006] In the TPE foam material, the weight ratio of SEBS-g-MAH and POE-g-GMA is (5-10):(3-5).

[0007] The TPE foam material, by weight, also includes 0.3 to 1.2 parts of silane coupling agent in its preparation raw materials.

[0008] In the TPE foam material, the silane coupling agent is at least one of γ-aminopropyltriethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

[0009] In the TPE foam material, the inorganic filler is a mixture of calcium carbonate and talc, and the weight ratio of calcium carbonate and talc is (1.8~2):1.

[0010] In the TPE foam material, the calcium carbonate has a mesh size of 1200-1250; the talc has a mesh size of 2000.

[0011] In the TPE foam material, the processing oil is naphthenic oil; the foaming agent is AC foaming agent.

[0012] A second aspect of the present invention provides a method for preparing the above-described TPE foam material, comprising the following steps: S10. Weigh SEBS, inorganic filler, processing oil, compatibilizer, foaming agent, zinc oxide and stearic acid according to the proportion and mix and plasticize them in an internal mixer. Then mix and refine them in an open mill. Finally, put them into an extruder and form them into sheets through a die to obtain the mixture. S20. Place the mixture in a mold, hot-press and foam it to obtain a sheet; S30. The sheet is welded together and then cut into sheets using a continuous sheet-cutting machine to obtain TPE foam material.

[0013] In the preparation method of the TPE foam material, the temperature of the internal mixer in step S10 is 130-150℃; the temperature of the open mill is 120-145℃; the temperature of the extruder is 130-155℃; and the temperature of the hot pressing foam in step S20 is 165-175℃, with a holding time of 12-15 min.

[0014] A third aspect of the present invention provides a composite yoga mat, comprising, from bottom to top, a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material described above.

[0015] Beneficial effects: The first aspect of this invention provides a TPE foam material. By using two compatibilizers, SEBS-g-MAH and POE-g-GMA, the TPE foam material and the rubber substrate can be hot-pressed together, forming a dual bond of hydrogen bonds and covalent bonds at the interface between the TPE foam material and the rubber substrate. This can completely improve the problem of low bonding strength between the foam layer and the rubber substrate and easy delamination caused by the large polarity difference between TPE material and rubber material in traditional TPE composite pads.

[0016] The second aspect of the present invention provides a method for preparing TPE foam material. The method for preparing TPE foam material can be carried out on a large scale using existing yoga mat foaming equipment, and has strong process stability, which is convenient for industrial promotion and production. It can efficiently prepare TPE foam material that can be tightly bonded to rubber and is tear-resistant.

[0017] The third aspect of this invention provides a composite yoga mat with clearly defined functions for each layer. The rubber bottom layer is responsible for anti-slip grip, the TPE foam layer provides cushioning and rebound for a comfortable feel, and the hot melt adhesive layer ensures a stable and strong interface bond between the two layers during the hot-pressing process. This synergistic effect of the three layers results in excellent performance in terms of anti-slip properties, cushioning, flexibility, and durability. It effectively meets the comprehensive performance requirements of low-impact exercises such as yoga and Pilates, and is particularly suitable for high-end yoga mats that require frequent folding and carrying, as well as maintaining structural stability under high-intensity use. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating the preparation process of the TPE foam material provided by the present invention.

[0019] Figure 2 This is a top view of the composite yoga mat in Example 1. Detailed Implementation

[0020] This invention provides a TPE foam material, its preparation method, and a composite yoga mat. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0021] The first aspect of the present invention provides a TPE foam material, which, after being made into a sheet, can be laminated with other sheet materials (such as a rubber backing) by hot pressing to form a composite yoga mat.

[0022] Specifically, by weight, the raw materials for its preparation include: 40-60 parts of SEBS, 20-40 parts of inorganic filler, 12-15 parts of processing oil, 8-15 parts of compatibilizer, 1.5-3 parts of foaming agent, 0.5-1 part of zinc oxide, and 0.2-0.8 parts of stearic acid.

[0023] In the raw materials for preparing the aforementioned TPE foam material, SEBS is a hydrogenated styrene-butadiene-styrene block copolymer, which is the basic elastomer of the TPE foam material of this invention. The elastomer molecules have polystyrene hard segments at both ends and styrene soft segments in the middle. During friction, when external force deforms the cell walls of the TPE foam material, the SEBS molecular chains can rapidly extend and store energy like a spring, and quickly retract after the external force is removed. This excellent resilience significantly reduces the permanent deformation of the TPE foam material, allowing the cell structure of yoga mats made from TPE foam material to remain more intact and less prone to collapse even after long-term use. The yoga mats will not experience localized excessive hardness or foot vibration.

[0024] In the raw materials for preparing the aforementioned TPE foam material, inorganic fillers, as a low-cost filler matrix, can reduce raw material costs. Furthermore, when inorganic fillers are uniformly distributed within the SEBS matrix, they act as foaming nucleation points, resulting in fine and uniform pores in the TPE foam material. This fine and uniform pore structure ensures a consistent overall hardness distribution in the TPE foam material, providing a smooth and balanced cushioning and rebound when stepped on, preventing localized excessive hardness, collapse, or foot jarring. Simultaneously, the uniform and fine pore structure of the TPE foam material enhances its tensile strength, tear strength, and dimensional stability, reducing permanent compression deformation after long-term pressure on the yoga mat, making it less prone to denting, deformation, cracking, or damage after repeated use. Processing oils can swell the SEBS elastic matrix, reducing the hardness of the TPE foam material and preventing the yoga mat from being too hard or irritating to the skin, meeting the need for a soft feel. Furthermore, processing oils can reduce melt viscosity, improving the processing performance of processes such as mixing, open milling, and extrusion.

[0025] In the raw materials for preparing the aforementioned TPE foam material, zinc oxide and stearic acid are both functional additives. Zinc oxide lowers the decomposition temperature of the foaming agent, allowing for a stable and uniform release of foaming gas, thus preventing cell rupture and interconnection caused by a sudden surge in gas production. Stearic acid, as a lubricant, reduces internal friction between components during the mixing process, improves processing fluidity, and ensures uniform mixing of the materials.

[0026] To improve the interlayer bonding between the TPE foam material and the rubber substrate, the compatibilizer used in the TPE foam material of this invention is a mixture of SEBS-g-MAH and POE-g-GMA. SEBS-g-MAH is maleic anhydride-grafted SEBS, with one end of its molecular chain retaining the SEBS chain segment structure, allowing for good compatibility with the SEBS matrix. Meanwhile, the maleic anhydride polar groups at the other end of the molecular chain can form hydrogen bonds with the hydroxyl and amino groups in the rubber and hot melt adhesive during the hot-pressing process of the TPE foam material and the rubber substrate. This enhances the interlayer bonding between the TPE foam material and the rubber, making it less likely for the TPE foam material to peel off from the rubber substrate. Meanwhile, the maleic anhydride polar groups on the SEBS-g-MAH molecular chain can chemically bond with the hydroxyl groups on the surface of the inorganic filler, improving the interfacial compatibility between the inorganic filler and the organic matrix, and enabling the inorganic filler to be uniformly dispersed in the SEBS matrix. This ensures that a uniform and dense cell structure can be formed inside the TPE foam material, and yoga mats made with this TPE foam material can obtain excellent mechanical properties.

[0027] POE-g-GMA is a polyolefin elastomer grafted with glycidyl methacrylate. Its POE backbone exhibits excellent flexibility, allowing it to penetrate and wrap around the SEBS matrix, thus enhancing the toughness of TPE foam materials. When TPE foam is compounded with rubber, the POE backbone can buffer interfacial bending stress, preventing stress concentration and cracking of the TPE foam under load. Simultaneously, the glycidyl methacrylate grafted onto the polyolefin elastomer possesses epoxy groups, which can react with hydroxyl groups and other groups on the surface of the rubber substrate to form chemical bonds at the interface. This further enhances the interlayer bonding between the TPE foam and the rubber substrate, making the TPE foam less prone to peeling off.

[0028] As can be seen, by using SEBS-g-MAH and POE-g-GMA compatibilizers in combination, this invention enables the TPE foam material to be hot-pressed with rubber, forming a dual bond of hydrogen bonds and covalent bonds at the interface between the TPE foam material and the rubber substrate. This completely improves the problem of low bonding strength between the foam layer and the rubber layer and easy delamination caused by the large polarity difference between TPE and rubber materials in traditional TPE composite pads.

[0029] Among the compatibilizers mentioned, SEBS-g-MAH and POE-g-GMA affect the melt flowability, interfacial adhesion, mechanical properties, and fatigue bending resistance of TPE foam. Specifically, SEBS-g-MAH has a high molecular chain rigidity; if the proportion of SEBS-g-MAH in the compatibilizer is too high, it will lead to a decrease in melt flowability. When hot-pressing TPE foam and rubber underlayer, the ability of the TPE foam surface to melt, spread, and wet the rubber surface deteriorates, which weakens the bond strength between the TPE foam and the rubber underlayer. In addition, a high proportion of SEBS-g-MAH in the compatibilizer will increase the modulus of the TPE foam. When the composite yoga mat is repeatedly bent, microcracks are easily generated inside the TPE foam, leading to cracking of the foam under long-term fatigue conditions.

[0030] If the proportion of POE-g-GMA in the compatibilizer is too high, the excessive amount of POE-g-GMA will make the interfacial layer too soft and viscoelastic. During the hot-pressing process of yoga mats, the overly soft interfacial layer is prone to lateral flow and creep under pressure, which can lead to relative slippage between the rubber base and the TPE foam material. This prevents the effective transfer of peel stress and makes the TPE foam material easy to peel off.

[0031] Furthermore, although POE and SEBS both belong to polyolefin elastomers, their structures differ significantly. When there is an excessive amount of POE-g-GMA, it cannot be effectively anchored by the SEBS matrix and will form independent island-like aggregates within the matrix. These aggregates, acting as stress concentration points, will significantly reduce the tensile and tear strength of the TPE foam material itself, causing yoga mats to easily crack and shed fibers during use.

[0032] In a preferred embodiment, the weight ratio of SEBS-g-MAH and POE-g-GMA is (5-10):(3-5). This ratio can improve the bonding strength between the TPE foam material and the rubber substrate, making it less likely for the TPE foam material to peel off from the rubber substrate.

[0033] To ensure uniform dispersion of the inorganic filler within the SEBS matrix, in a preferred embodiment, the raw materials for preparing the TPE foam material further include 0.3–1.2 parts by weight of a silane coupling agent. The alkoxy group at one end of the silane coupling agent can react with the hydroxyl groups on the surface of the inorganic filler to form a chemical bond, changing the surface of the inorganic filler from hydrophilic to lipophilic. This reduces the interfacial tension between the inorganic filler and the SEBS matrix, preventing agglomeration of the inorganic filler and reducing crack initiation sites within the TPE foam material, thereby contributing to improved tear strength. Furthermore, during hot-pressing of the yoga mat, the amino groups in the silane coupling agent can react with the polar groups on the rubber surface and the hot melt adhesive components, further enhancing the interlayer bonding between the TPE foam material and the rubber substrate.

[0034] For example, the silane coupling agent is at least one of γ-aminopropyltriethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

[0035] In a preferred embodiment, the inorganic filler is a mixture of calcium carbonate and talc.

[0036] Among the inorganic fillers mentioned above, calcium carbonate provides a large number of uniform, rigid nucleation sites, which is beneficial for the formation of a dense, high-closed-cell structure within the TPE foam material. Simultaneously, calcium carbonate enhances the hardness and resistance to compression set of the TPE foam material, preventing the yoga mat from easily collapsing after prolonged use. Talc, with its flake-like structure, effectively inhibits excessive bubble expansion and bubble coalescence. Furthermore, the oriented arrangement of talc flakes forms a continuous stress transfer network, hindering crack propagation when the yoga mat is stretched or bent, thus improving the tear strength of the TPE foam material.

[0037] Furthermore, calcium carbonate has a surface rich in hydroxyl groups, and the silicate layers of talc also contain polar silanol groups. After being coated with a silane coupling agent, both types of fillers have active amino groups grafted onto their surfaces. During mixing and hot pressing, these modified fillers can be uniformly dispersed and enriched on the surface of the TPE foam material; their amino groups can bond and anchor with the compatibilizer in the SEBS matrix, and during hot pressing, they can form a dense hydrogen bond network with the double bonds and polar groups on the rubber underlayer molecular chains, thereby further enhancing the interlayer bonding between the TPE foam material and the rubber underlayer.

[0038] The ratio of calcium carbonate to talc in inorganic fillers directly affects the overall mechanical properties, cell structure stability, and long-term durability of TPE foam materials. If the proportion of calcium carbonate in the inorganic filler is too high and the proportion of flaky talc is insufficient, a continuous stress transfer network cannot be guaranteed within the TPE foam material, resulting in limited improvement in tear strength. If the proportion of talc in the inorganic filler is too high, the excessive lamellar structure is prone to highly oriented stacking in the shear flow field of the SEBS matrix. This not only significantly increases the mechanical anisotropy of the TPE foam material in the longitudinal and transverse directions, but more critically, it creates numerous chemically unbonded physical interfaces between the lamellars. During the dynamic service of the composite yoga mat under repeated bending, stress concentrates at the lamellar interfaces, easily leading to interface debonding and relative slippage, causing rapid propagation of microcracks, thus significantly deteriorating the fatigue bending life and structural stability of the composite yoga mat. In a preferred embodiment, the ratio of calcium carbonate to talc is (1.8-2):1 by weight, which improves the service life of TPE foam material under repeated compression and bending conditions, ensuring that the composite yoga mat has both flexibility and structural integrity.

[0039] In order to enable calcium carbonate to provide a large number of uniform foaming nucleation sites in the SEBS matrix, so that a fine pore structure can be formed inside the TPE foam material, in a preferred embodiment, the calcium carbonate has a mesh size of 1200-1250 mesh.

[0040] In order to enable talc powder to be uniformly dispersed in the SEBS matrix to form a continuous stress barrier network and thereby improve the tear resistance of TPE foam material, in a preferred embodiment, the talc powder has a mesh size of 2000.

[0041] As an example, the processing oil is preferably a naphthenic oil. Naphthenic oil can swell the ethylene-butene soft segments of SEBS, weaken the entanglement between molecular chains, reduce the torque during mixing and extrusion, and make the material mix evenly and extrusion foam smoothly.

[0042] As an example, the foaming agent is preferably an AC foaming agent. The AC foaming agent can uniformly release nitrogen gas when decomposed at high temperature, forming closed microbubbles inside the SEBS matrix. In addition, in conjunction with the nucleation points formed by inorganic fillers, a large number of microbubbles can be generated simultaneously, resulting in a dense pore structure in the TPE foam material.

[0043] like Figure 1 As shown, a second aspect of the present invention provides a method for preparing the above-described TPE foam material, comprising the following steps: S10. Weigh SEBS, inorganic filler, processing oil, compatibilizer, foaming agent, zinc oxide and stearic acid according to the proportion and mix and plasticize them in an internal mixer. Then mix and refine them in an open mill. Finally, put them into an extruder and form them into sheets through a die to obtain the mixture. S20. Place the mixture in a mold, hot-press and foam it to obtain a sheet; S30. The sheet is welded together and then cut into sheets using a continuous sheet-cutting machine to obtain TPE foam material.

[0044] The method for preparing the TPE foam material can be implemented on a large scale using existing yoga mat foaming equipment. It has strong process stability, is easy to promote and produce industrially, and can efficiently prepare TPE foam materials that can be tightly bonded to rubber and are tear-resistant.

[0045] In a preferred embodiment, the temperature of the internal mixer in step S10 is 130–150°C; the temperature of the open mill is 120–145°C; and the temperature of the extruder is 130–155°C.

[0046] Maintaining a mixing temperature of 130–150℃ allows SEBS to fully plasticize and fuse with SEBS-g-MAH and POE-g-GMA, promoting the dispersion of inorganic fillers while preventing premature decomposition of the foaming agent. Setting the open mill temperature at 120–145℃ further optimizes the dispersion of inorganic fillers and improves the overall uniformity of the compound. Setting the extruder temperature at 130–155℃ allows the material to melt and plasticize, resulting in a smooth surface and uniform distribution of components in the extruded preform. This temperature is still below the foaming temperature, preventing premature foaming during the mixing and extrusion process, thus ensuring the stable operation of subsequent foaming processes and ultimately producing a TPE foam material with fine and uniform cells.

[0047] In order to form a uniform and dense cell structure in the TPE foam material during the hot-pressing foaming process, in the preparation method of the TPE foam material, the hot-pressing foaming temperature in step S20 is 165-175℃ and the holding time is 12-15min.

[0048] A third aspect of the present invention provides a composite yoga mat, comprising, from bottom to top, a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material described above.

[0049] The composite yoga mat provided by this invention can be laminated using a conventional hot-pressing process. Each layer of the composite yoga mat has a clearly defined function. The rubber bottom layer is responsible for anti-slip grip, the TPE foam layer provides cushioning and a comfortable feel, and the hot-melt adhesive layer ensures a stable and strong interface bond between the two layers during the hot-pressing process. This three-layer structure works synergistically, resulting in excellent performance in terms of anti-slip properties, cushioning, flexibility, and durability. It effectively meets the comprehensive performance requirements of low-impact exercises such as yoga and Pilates, and is particularly suitable for high-end yoga mats that require frequent folding and carrying, as well as maintaining structural stability under high-intensity use.

[0050] The following examples and comparative examples further illustrate the present invention. The sources of some of the raw materials used in the following examples and comparative examples are as follows: SEBS: Baling Petrochemical YH-502T; SEBS-g-MAH: Kraton FG1901; POE-g-GMA: Runfeng Petrochemical W5A.

[0051] Example 1 This embodiment provides a TPE foam material, the raw materials for which, by weight, are: The composition includes 50 parts SEBS, 30 parts inorganic filler, 13 parts naphthenic oil, 10 parts compatibilizer, 2 parts AC foaming agent, 0.8 parts zinc oxide, 0.8 parts γ-aminopropyltriethoxysilane, and 0.6 parts stearic acid; the compatibilizer is a mixture of SEBS-g-MAH and POE-g-GMA.

[0052] The SEBS-g-MAH and POE-g-GMA are mixed in a weight ratio of 5:5, or 1:1.

[0053] The inorganic filler is a mixture of calcium carbonate and talc; the calcium carbonate has a mesh size of 1250 mesh and the talc has a mesh size of 2000 mesh; the ratio of calcium carbonate to talc by weight is 2:1.

[0054] This embodiment also provides a method for preparing the TPE foam material of this embodiment, including the following steps: S10. Weigh SEBS, inorganic filler, processing oil, compatibilizer, foaming agent, zinc oxide and stearic acid according to the proportion and mix and plasticize them in an internal mixer. Then mix and refine them in an open mill. Finally, put them into an extruder and form them into sheets through a die to obtain the mixture. S20. Place the mixture in a mold, hot-press and foam it to obtain a sheet; S30. The sheet is welded together and then cut into sheets using a continuous sheet-cutting machine to obtain foamed material.

[0055] In step S10, the temperature of the internal mixer is 135°C; the temperature of the open mill is 140°C; the temperature of the extruder is 145°C; and in step S20, the temperature of the hot pressing foaming is 170°C, and the holding time is 13 minutes.

[0056] This embodiment also provides a composite yoga mat, which includes, from bottom to top, a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material of this embodiment.

[0057] Example 2 This embodiment provides a TPE foam material, the raw materials for which, by weight, are: The composition includes 40 parts SEBS, 28 parts inorganic filler, 12 parts naphthenic oil, 8 parts compatibilizer, 1.5 parts AC foaming agent, 0.5 parts zinc oxide, 0.3 parts γ-aminopropyltriethoxysilane, and 0.2 parts stearic acid; the compatibilizer is a mixture of SEBS-g-MAH and POE-g-GMA.

[0058] The ratio of SEBS-g-MAH and POE-g-GMA by weight is 5:3.

[0059] The inorganic filler is a mixture of calcium carbonate and talc; the calcium carbonate has a mesh size of 1250 mesh and the talc has a mesh size of 2000 mesh; the weight ratio of calcium carbonate to talc is 1.8:1.

[0060] This embodiment also provides a method for preparing the TPE foam material of this embodiment, including the following steps: S10. Weigh SEBS, inorganic filler, processing oil, compatibilizer, foaming agent, zinc oxide and stearic acid according to the proportion and mix and plasticize them in an internal mixer. Then mix and refine them in an open mill. Finally, put them into an extruder and form them into sheets through a die to obtain the mixture. S20. Place the mixture in a mold, hot-press and foam it to obtain a sheet; S30. The sheet is welded together and then cut into sheets using a continuous sheet-cutting machine to obtain foamed material.

[0061] In step S10, the temperature of the internal mixer is 130°C; the temperature of the open mill is 140°C; the temperature of the extruder is 155°C; and in step S20, the temperature of the hot pressing foaming is 165°C, and the holding time is 12 minutes.

[0062] This embodiment also provides a composite yoga mat, which includes, from bottom to top, a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material of this embodiment.

[0063] Example 3 This embodiment provides a TPE foam material, the raw materials for which, by weight, are: The composition includes 60 parts SEBS, 36 parts inorganic filler, 15 parts naphthenic oil, 15 parts compatibilizer, 3 parts AC foaming agent, 1 part zinc oxide, 1.2 parts γ-aminopropyltriethoxysilane, and 0.8 parts stearic acid; the compatibilizer is a mixture of SEBS-g-MAH and POE-g-GMA.

[0064] The ratio of SEBS-g-MAH and POE-g-GMA by weight is 10:5.

[0065] The inorganic filler is a mixture of calcium carbonate and talc; the calcium carbonate has a mesh size of 1250 mesh and the talc has a mesh size of 2000 mesh; the ratio of calcium carbonate to talc by weight is 2:1.

[0066] This embodiment also provides a method for preparing the TPE foam material of this embodiment, including the following steps: S10. Weigh SEBS, inorganic filler, processing oil, compatibilizer, foaming agent, zinc oxide and stearic acid according to the proportion and mix and plasticize them in an internal mixer. Then mix and refine them in an open mill. Finally, put them into an extruder and form them into sheets through a die to obtain the mixture. S20. Place the mixture in a mold, hot-press and foam it to obtain a sheet; S30. The sheet is welded together and then cut into sheets using a continuous sheet-cutting machine to obtain foamed material.

[0067] In step S10, the temperature of the internal mixer is 140°C; the temperature of the open mill is 145°C; the temperature of the extruder is 155°C; and in step S20, the temperature of the hot pressing foam is 175°C, and the holding time is 15 minutes.

[0068] This embodiment also provides a composite yoga mat, which includes, from bottom to top, a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material of this embodiment.

[0069] Comparative Example 1 This comparative example provides a TPE foam material. Compared with the raw materials used to prepare the TPE foam material in Example 1, the only difference is that the amount of compatibilizer is reduced from 10 parts to 2 parts. The compatibilizer is still a mixture of SEBS-g-MAH and POE-g-GMA, and the ratio of SEBS-g-MAH to POE-g-GMA is still 1:1.

[0070] This comparative example also provides a method for preparing the TPE foam material of this comparative example, which is the same as the preparation method provided in Example 1.

[0071] This comparative example also provides a composite yoga mat, which, from bottom to top, comprises a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material of this comparative example.

[0072] Comparative Example 2 This comparative example provides a TPE foam material, which differs from the TPE foam material of Example 1 only in that the ratio of SEBS-g-MAH and POE-g-GMA is 8:2.

[0073] This comparative example also provides a method for preparing the TPE foam material of this comparative example, which is the same as the preparation method provided in Example 1.

[0074] This comparative example also provides a composite yoga mat, which, from bottom to top, comprises a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material of this comparative example.

[0075] Comparative Example 3 This comparative example provides a TPE foam material, which differs from the TPE foam material of Example 1 only in that the ratio of SEBS-g-MAH and POE-g-GMA is 2:8.

[0076] This comparative example also provides a method for preparing the TPE foam material of this comparative example, which is the same as the preparation method provided in Example 1.

[0077] This comparative example also provides a composite yoga mat, which, from bottom to top, comprises a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material of this comparative example.

[0078] Comparative Example 4 This comparative example provides a TPE foam material. The only difference between this TPE foam material and the TPE foam material of Example 1 is that γ-aminopropyltriethoxysilane is not used in the raw materials. The compatibilizer is still a mixture of SEBS-g-MAH and POE-g-GMA, and the ratio of SEBS-g-MAH to POE-g-GMA is still 1:1.

[0079] This comparative example also provides a method for preparing the TPE foam material of this comparative example, which is the same as the preparation method provided in Example 1.

[0080] This comparative example also provides a composite yoga mat, which, from bottom to top, comprises a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material of this comparative example.

[0081] Comparative Example 5 This comparative example provides a TPE foam material. The only difference between this TPE foam material and the TPE foam material in Example 1 is that the ratio of calcium carbonate and talc in the inorganic filler is 0.5:2.5 by weight.

[0082] This comparative example also provides a method for preparing the TPE foam material of this comparative example, which is the same as the preparation method provided in Example 1.

[0083] This comparative example also provides a composite yoga mat, which, from bottom to top, comprises a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material of this comparative example.

[0084] Comparative Example 6 This comparative example provides a TPE foam material. The only difference between this TPE foam material and the TPE foam material in Example 1 is that the ratio of calcium carbonate and talc in the inorganic filler is 2.5:0.5 by weight.

[0085] This comparative example also provides a method for preparing the TPE foam material of this comparative example, which is the same as the preparation method provided in Example 1.

[0086] This comparative example also provides a composite yoga mat, which, from bottom to top, comprises a rubber bottom layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material of this comparative example.

[0087] Peel strength tests were conducted on the composite yoga mats provided in the above embodiments and comparative examples. The test results are shown in Table 1 below. The tests were conducted in accordance with the provisions of standard TY / T 3802.1-2024 "Requirements and Test Methods for Use of Fitness Yoga Mats and Sports Equipment Part 1: Yoga Mats" and standard GB / T 8808-1988 "Peel Test Method for Soft Composite Plastic Materials".

[0088] The composite yoga mats provided in the above embodiments and comparative examples were subjected to bending resistance tests. The tests were conducted using a DeMattia reciprocating bending tester with a bending stroke of 20 mm and a frequency of 120 times / min. After 5000 consecutive bends, it was observed whether interlayer separation occurred between the TPE foam layer and the rubber bottom layer of the composite yoga mat. The test results are shown in Table 1 below.

[0089] The TPE foam layer in each of the above embodiments and comparative examples was tested individually to determine its tear strength. The tests were conducted according to standard GB / T 529-2008 "Determination of Tear Strength of Vulcanized Rubber or Thermoplastic Rubber", and the test results are shown in Table 1 below.

[0090] Table 1 (15 mm in Table 1 represents the sample width):

[0091] The test results in Table 1 show that the interlayer peel strength of the composite yoga mats provided in Examples 1-3 is greater than 20 N / 15 mm, and the tear strength of the TPE foam layer is stable at over 122 kN / m. This indicates that by using SEBS-g-MAH and POE-g-GMA compatibilizers, the present invention can improve the problem of low bonding strength between the foam layer and the rubber bottom layer in traditional TPE composite mats, which is caused by the large difference in polarity between TPE and rubber materials, and easy delamination.

[0092] Comparing Comparative Example 1 with Example 1, it was found that the test results of Comparative Example 1 were not as good as those of Example 1. This is because the amount of compatibilizer in the raw material system of the TPE foam material in Comparative Example 1 was too small, and there was a lack of sufficient polar groups between the TPE foam layer and the rubber underlayer to form a dual combination of hydrogen bonds and covalent bonds at the interface.

[0093] Comparing Comparative Example 2 with Example 1, it was found that the test results of Comparative Example 2 were not as good as those of Example 1. This was because the proportion of SEBS-g-MAH in the compatibilizer system was too high. Comparing Comparative Example 3 with Example 1, it was found that the test results of Comparative Example 3 were not as good as those of Example 1. This was because the proportion of POE-g-GMA in the compatibilizer system was too high.

[0094] Comparing Comparative Example 4 with Example 1, it was found that the test results of Comparative Example 4 were not as good as those of Example 1. This is because no silane coupling agent was introduced into the raw material system of the TPE foam material in Comparative Example 4.

[0095] Comparing Comparative Example 5 with Example 1, it was found that the test results of Comparative Example 5 were not as good as those of Example 1. This was because the proportion of talc in the inorganic filler was too high. Comparing Comparative Example 6 with Example 1, it was found that the test results of Comparative Example 6 were not as good as those of Example 1. This was because the proportion of calcium carbonate in the inorganic filler was too high, and the amount of talc was insufficient.

[0096] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A TPE foam material, characterized in that, The raw materials for its preparation, by weight, include: The composition includes 40-60 parts SEBS, 20-40 parts inorganic filler, 12-15 parts processing oil, 8-15 parts compatibilizer, 1.5-3 parts foaming agent, 0.5-1 part zinc oxide, and 0.2-0.8 parts stearic acid; the compatibilizer is a mixture of SEBS-g-MAH and POE-g-GMA.

2. The TPE foam material according to claim 1, characterized in that, The SEBS-g-MAH and POE-g-GMA are mixed in a weight ratio of (5-10):(3-5).

3. The TPE foam material according to claim 1, characterized in that, The raw materials for its preparation also include 0.3 to 1.2 parts by weight of silane coupling agent.

4. The TPE foam material according to claim 3, characterized in that, The silane coupling agent is at least one of γ-aminopropyltriethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

5. The TPE foam material according to claim 1, characterized in that, The inorganic filler is a mixture of calcium carbonate and talc, with the weight ratio of calcium carbonate to talc being (1.8-2):

1.

6. The TPE foam material according to claim 5, characterized in that, The calcium carbonate has a mesh size of 1200-1250; the talc has a mesh size of 2000.

7. The TPE foam material according to claim 1, characterized in that, The processing oil is a naphthenic oil; the foaming agent is an AC foaming agent.

8. A method for preparing the TPE foam material according to any one of claims 1-7, comprising the following steps: S10. Weigh SEBS, inorganic filler, processing oil, compatibilizer, foaming agent, zinc oxide and stearic acid according to the proportion and mix and plasticize them in an internal mixer. Then mix and refine them in an open mill. Finally, put them into an extruder and form them into sheets through a die to obtain the mixture. S20. Place the mixture in a mold, hot-press and foam it to obtain a sheet; S30. The sheet is welded together and then cut into sheets using a continuous sheet-cutting machine to obtain TPE foam material.

9. The method for preparing TPE foam material according to claim 8, characterized in that, In step S10, the temperature of the internal mixer is 130-150℃; the temperature of the open mill is 120-145℃; the temperature of the extruder is 130-155℃; in step S20, the temperature of the hot pressing foam is 165-175℃, and the holding time is 12-15 minutes.

10. A composite yoga mat, characterized in that, From bottom to top, it comprises a rubber base layer, a hot melt adhesive layer, and a TPE foam layer; the TPE foam layer is made of the TPE foam material according to any one of claims 1-7.

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