EVA (Ethylene Vinyl Acetate) slow-rebound anti-slip sole or slipper and preparation method thereof

Abstract

The invention provides an EVA (Ethylene Vinyl Acetate) slow-rebound anti-skid sole or slipper and a preparation method thereof, and belongs to the technical field of slow-rebound sole materials. The EVA slow-rebound antiskid sole or slipper is prepared from the following raw materials in parts by mass: 50-70 parts of EVA; 10-30 parts of a thermoplastic elastomer; 10 to 15 parts of SBR rubber powder; 5 to 8 parts of nano silicon dioxide; 0.5 to 2 parts of a fluorinated modifier; 1-5 parts of a silane coupling agent; and 1-5 parts of a cross-linking agent. The thermoplastic elastomer and the EVA are compounded for use, so that the flexibility and the microscopic roughness of the sole are improved, and the road holding force of the sole is enhanced. The addition of the hydrogenated styrene elastomer can improve the low-temperature skid resistance and reduce the risk of skid on the ice surface. Through compounding of the raw materials, the good resilience of the sole is kept, the anti-skid performance of the sole is further improved, and the sole is safer and more comfortable to use in special sports occasions.

Description

Technical Field

[0001] The invention relates to the technical field of slow-rebound sole materials, in particular to an EVA slow-rebound anti-skid sole or slipper and a preparation method thereof. Background Art

[0002] With the development of society and the improvement of people's living standards, people are shifting from traditional demands for warmth and protection in shoes to demands that they be lightweight, soft, and comfortable. Traditional EVA resin, with its excellent elasticity and plasticity, and its lightweight foam, is popular and widely used in the field of shoe sole materials. However, EVA resin exhibits significant compression deformation after foaming. EVA resin-based soles can easily experience heel collapse, soft material, and poor wear resistance after wear. With the advancement of social development and a deeper understanding of environmental protection, the recycling of waste rubber is increasing. Combining abundant and inexpensive rubber with EVA resin not only reduces the production cost of shoe sole materials and improves resource recycling, but also significantly improves the performance of EVA resin.

[0003] Patent CN201711033480.1 provides a high-rebound composite foam material for soles and a preparation method thereof. TPU / EVA alloy is used to increase the volume to form an EVA / TPU interpenetrating network. The prepared sole material has excellent resilience and wear resistance. However, due to the large content of TPU / EVA alloy in the foam material, the foam material has a high hardness and poor anti-slip performance.

[0004] Therefore, how to obtain a kind of EVA slow rebound anti-skid sole or slipper and preparation method thereof is the technical problem that needs to be solved at present. Summary of the Invention

[0005] The purpose of the present invention is to provide an EVA slow-rebound anti-skid sole or slipper and a preparation method thereof, so as to solve the technical problem that the existing EVA sole material cannot have both slow rebound and anti-skid properties.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides an EVA slow-rebound anti-skid sole or slipper, which is prepared from raw materials containing the following parts by mass:

[0008]

[0009]

[0010] Furthermore, the mass content of VA in the EVA is 18-28%.

[0011] Furthermore, the thermoplastic elastomer includes one or more of polyurethane elastomer, thermoplastic rubber and hydrogenated styrene elastomer.

[0012] Furthermore, the particle size of the SBR rubber powder is 80-200 mesh, and the particle size of the nano-silicon dioxide is 50-100 nm.

[0013] Furthermore, the fluorinated modifier comprises polytetrafluoroethylene powder, and the particle size of the polytetrafluoroethylene powder is 0.1 to 5 μm.

[0014] Furthermore, the silane coupling agent comprises KH-550, KH-560 or A-171 silane coupling agent;

[0015] The cross-linking agent comprises one or more of dicumyl peroxide, di-tert-butyl peroxycumene and tert-amyl peroxy (2-ethylhexyl) carbonate.

[0016] The present invention also provides a method for preparing an EVA slow-rebound anti-skid sole or slipper, comprising the following steps:

[0017] 1) EVA, a thermoplastic elastomer, SBR rubber powder, and a fluorinated modifier are mixed according to parts by mass and then kneaded, and then nano-silica, a silane coupling agent, and a cross-linking agent are added and further kneaded to obtain a blend, which is granulated and cooled to obtain a foamed granular material;

[0018] 2) placing the foamed granules in a mold, hot pressing and cooling to obtain a foamed blank;

[0019] 3) placing the foamed green sheet in a reactor and introducing supercritical gas to perform supercritical foaming, and releasing the pressure after the gas is saturated, thereby obtaining the EVA slow-rebound anti-skid sole or slipper.

[0020] Furthermore, in the step 1), the banburying temperature is 160-180° C., and the banburying time is 3-10 min;

[0021] The temperature of the hot pressing molding is 130-200° C., and the time of the hot pressing molding is 3-5 minutes.

[0022] Furthermore, the supercritical gas includes supercritical CO2, supercritical N2, supercritical ethanol or supercritical propane.

[0023] Furthermore, the supercritical foaming temperature is 100-200° C., the saturation is carried out at a pressure of 20-30 MPa for 2-4 hours, and the pressure relief rate is 5-15 MPa / s.

[0024] Beneficial effects of the present invention:

[0025] The present invention improves the flexibility and micro-roughness of the sole and enhances the grip of the sole by compounding thermoplastic elastomer with EVA. The addition of hydrogenated styrene elastomer improves low-temperature skid resistance and reduces the risk of slipping on icy surfaces.

[0026] In the present invention, the thermoplastic elastomer and EVA form a cross-linked network under the action of a silane coupling agent. The silane coupling agent forms a Si-O-Si network through hydrolysis and condensation during processing, interacting with the vinyl acetate (VA) polar groups of the EVA to increase the entanglement and cross-linking density of the molecular chains. At the same time, the thermoplastic elastomer is embedded in the cross-linked network to improve the slow rebound performance of the material.

[0027] By combining a fluorinated modifier with nano-silica, the present invention utilizes their micron-scale physical structures to reduce the surface energy of the material, reduce water film adsorption, and improve the wet-slip performance of the sole. The addition of a silane coupling agent improves the dispersion of the fluorinated modifier and nano-silica. The three work together to create a synergistic effect, effectively enhancing the anti-slip performance of the sole or slipper.

[0028] The present invention adds a small amount of SBR rubber powder to compensate for the relatively soft and poor resilience of EVA as a sole material. The addition of SBR rubber powder effectively improves the rebound and friction properties of the EVA material, resulting in a sole or slipper with slow rebound properties. The material has moderate hardness and excellent anti-slip properties, and can be used in high-performance sports shoe soles. DETAILED DESCRIPTION

[0029] The present invention provides an EVA slow-rebound anti-skid sole or slipper, which is prepared from raw materials containing the following parts by mass:

[0030]

[0031] In the present invention, the amount of EVA used is preferably 55 to 65 parts by mass, and more preferably 58 to 62 parts by mass.

[0032] In the present invention, the content of the thermoplastic elastomer is preferably 15 to 25 parts by mass, more preferably 18 to 22 parts by mass.

[0033] In the present invention, the amount of the SBR rubber powder is preferably 11 to 14 parts by mass, more preferably 12 to 13 parts by mass.

[0034] In the present invention, the amount of the nano-silica is preferably 6 to 7 parts by mass, more preferably 7 parts.

[0035] In the present invention, the amount of the fluorinated modifier is preferably 0.8 to 1.5 parts by mass, more preferably 1.0 part.

[0036] In the present invention, the amount of the silane coupling agent is preferably 2 to 4 parts by mass, more preferably 3 to 4 parts by mass.

[0037] In the present invention, the amount of the cross-linking agent is preferably 2 to 4 parts by mass, more preferably 3 to 4 parts by mass.

[0038] In the present invention, the mass content of VA in the EVA is 18-28%, preferably 20-25%, and more preferably 22-24%.

[0039] In the present invention, the thermoplastic elastomer includes one or more of polyurethane elastomer, thermoplastic rubber and hydrogenated styrene elastomer, preferably TPU, TPR, SEBS or SEPS.

[0040] In the present invention, the particle size of the SBR rubber powder is 80-200 mesh, preferably 100-180 mesh, more preferably 150 mesh; the particle size of the nano-silica is 50-100 nm, preferably 60-80 nm, more preferably 70-80 nm.

[0041] In the present invention, the fluorinated modifier comprises polytetrafluoroethylene powder, and the particle size of the polytetrafluoroethylene powder is 0.1 to 5 μm, preferably 1 to 4 μm, and more preferably 2 to 3 μm.

[0042] In the present invention, the silane coupling agent comprises KH-550, KH-560 or A-171 silane coupling agent, preferably KH-550;

[0043] The cross-linking agent comprises one or more of dicumyl peroxide, di-tert-butyl peroxyisopropylbenzene and tert-amyl peroxy (2-ethylhexyl) carbonate, preferably dicumyl peroxide.

[0044] The present invention also provides a method for preparing an EVA slow-rebound anti-skid sole or slipper, comprising the following steps:

[0045] 1) EVA, a thermoplastic elastomer, SBR rubber powder, and a fluorinated modifier are mixed according to parts by mass and then kneaded, and then nano-silica, a silane coupling agent, and a cross-linking agent are added and further kneaded to obtain a blend, which is granulated and cooled to obtain a foamed granular material;

[0046] 2) placing the foamed granules in a mold, hot pressing and cooling to obtain a foamed blank;

[0047] 3) placing the foamed green sheet in a reactor and introducing supercritical gas to perform supercritical foaming, and releasing the pressure after the gas is saturated, thereby obtaining the EVA slow-rebound anti-skid sole or slipper.

[0048] In the present invention, in step 1), the banburying temperature is 160-180° C., preferably 165-175° C., more preferably 170° C.; the banburying time is 3-10 min, preferably 4-9 min, more preferably 5-8 min;

[0049] The temperature of the hot pressing molding is 130-200° C., preferably 140-180° C., and more preferably 150-160° C.; the time of the hot pressing molding is 3-5 minutes, and preferably 4 minutes.

[0050] In the present invention, the supercritical gas comprises supercritical CO2, supercritical N2, supercritical ethanol or supercritical propane, preferably supercritical CO2.

[0051] In the present invention, the temperature of the supercritical foaming is 100-200°C, preferably 130-180°C, and more preferably 140-160°C; saturation is carried out for 2-4 hours at a pressure of 20-30 MPa, and the pressure relief rate is 5-15 MPa / s. Preferably, saturation is carried out for 3 hours at a pressure of 25 MPa, and the pressure relief rate is 8-12 MPa / s.

[0052] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0053] Example 1

[0054] A method for preparing an EVA slow-rebound anti-skid sole or slipper comprises the following steps:

[0055] raw material:

[0056]

[0057] The preparation process is as follows:

[0058] 1) EVA (VA content of 20%), thermoplastic elastomer TPU, SBR rubber powder (particle size of 200 mesh) and polytetrafluoroethylene powder (particle size of 2 μm) were mixed according to their weight proportions and kneaded at 170° C. for 3 minutes. Nano-silica (particle size of 50-60 nm), silane coupling agent KH-550 and dicumyl peroxide were then added and kneaded for another 5 minutes. The resulting blend was granulated and cooled to obtain foamed granules;

[0059] 2) placing the foamed granules in a mold, hot pressing at 150° C., and cooling to obtain a foamed green sheet;

[0060] 3) placing the foamed green sheet into a supercritical foaming reactor, injecting 20 MPa supercritical carbon dioxide, maintaining the pressure at 150° C. for 3 hours, and then releasing the pressure at a rate of 10 MPa / s to obtain an EVA slow-rebound anti-slip sole or slipper.

[0061] Example 2

[0062] A method for preparing an EVA slow-rebound anti-skid sole or slipper comprises the following steps:

[0063] raw material:

[0064]

[0065] The preparation process is as follows:

[0066] 1) EVA (VA content of 25%), thermoplastic elastomer TPR, SBR rubber powder (particle size of 150 mesh) and polytetrafluoroethylene powder (particle size of 5 μm) were mixed according to their weight proportions and kneaded at 180° C. for 5 minutes. Nano-silica (particle size of 60-70 nm), silane coupling agent KH-560 and di-tert-butyl peroxyisopropylbenzene were then added and kneaded for another 5 minutes. The resulting mixture was granulated and cooled to obtain foamed granules;

[0067] 2) placing the foamed granules in a mold, hot pressing at 200° C., and cooling to obtain a foamed green sheet;

[0068] 3) placing the foamed green sheet into a supercritical foaming reactor, injecting 25 MPa supercritical nitrogen, maintaining the pressure at 160° C. for 2 hours, and then releasing the pressure at a rate of 12 MPa / s to obtain an EVA slow-rebound anti-slip sole or slipper.

[0069] Example 3

[0070] A method for preparing an EVA slow-rebound anti-skid sole or slipper comprises the following steps:

[0071] raw material:

[0072]

[0073] The preparation process is as follows:

[0074] 1) EVA (VA content of 18%), thermoplastic elastomer SEBS, SBR rubber powder (particle size of 200 mesh), and polytetrafluoroethylene powder (particle size of 5 μm) were mixed according to their weight proportions and kneaded at 160° C. for 3 minutes. Nano-silica (particle size of 50-60 nm), silane coupling agent A-171, and dicumyl peroxide were then added and kneaded for another 5 minutes. The resulting blend was granulated and cooled to obtain foamed granules.

[0075] 2) placing the foamed granules in a mold, hot pressing at 130° C., and cooling to obtain a foamed green sheet;

[0076] 3) placing the foamed green sheet into a supercritical foaming reactor, injecting 20 MPa supercritical carbon dioxide, maintaining the pressure at 150° C. for 3 hours, and then releasing the pressure at a rate of 8 MPa / s to obtain an EVA slow-rebound anti-slip sole or slipper.

[0077] Example 4

[0078] A method for preparing an EVA slow-rebound anti-skid sole or slipper comprises the following steps:

[0079] raw material:

[0080]

[0081]

[0082] The preparation process is as follows:

[0083] 1) EVA (VA content of 21%), thermoplastic elastomer SEPS, SBR rubber powder (particle size of 150 mesh), and polytetrafluoroethylene powder (particle size of 2 μm) were mixed according to their weight proportions and kneaded at 165° C. for 3 minutes. Nano-silica (particle size of 50-60 nm), silane coupling agent KH-550, and dicumyl peroxide were then added and kneaded for another 5 minutes. The resulting blend was granulated and cooled to obtain foamed granules.

[0084] 2) placing the foamed granules in a mold, hot pressing at 170° C., and cooling to obtain a foamed green sheet;

[0085] 3) placing the foamed green sheet into a supercritical foaming reactor, injecting 20 MPa supercritical ethanol, maintaining the pressure at 150° C. for 3 hours, and then releasing the pressure at a rate of 10 MPa / s to obtain an EVA slow-rebound anti-slip sole or slipper.

[0086] Example 5

[0087] A method for preparing an EVA slow-rebound anti-skid sole or slipper comprises the following steps:

[0088] raw material:

[0089]

[0090] The preparation process is as follows:

[0091] 1) EVA (VA content of 25%), thermoplastic elastomer TPU, SBR rubber powder (particle size of 200 mesh) and polytetrafluoroethylene powder (particle size of 2 μm) were mixed according to their weight proportions and kneaded at 175° C. for 3 minutes. Nano-silica (particle size of 50-60 nm), silane coupling agent A-171 and dicumyl peroxide were then added and kneaded for another 5 minutes. The resulting blend was granulated and cooled to obtain foamed granules.

[0092] 2) placing the foamed granules in a mold, hot pressing at 150° C., and cooling to obtain a foamed green sheet;

[0093] 3) placing the foamed green sheet into a supercritical foaming reactor, injecting 25 MPa supercritical carbon dioxide, maintaining the pressure at 150° C. for 3 hours, and then releasing the pressure at a rate of 10 MPa / s to obtain an EVA slow-rebound anti-slip sole or slipper.

[0094] Comparative Example 1

[0095] The technical solution is the same as that of Example 1, except that the thermoplastic elastomer TPU is not added.

[0096] Comparative Example 2

[0097] The technical solution is the same as that of Example 2, except that polytetrafluoroethylene powder is not added.

[0098] Comparative Example 3

[0099] The technical solution is the same as that of Example 3, except that nano-silicon dioxide is not added.

[0100] Comparative Example 4

[0101] The technical solution is the same as that of Example 4, except that the amount of polytetrafluoroethylene powder used is 5 parts.

[0102] Comparative Example 5

[0103] The technical solution is the same as that of Example 5, except that the amount of SBR rubber powder is 25 parts.

[0104] Test Example 1

[0105] The above embodiment and comparative example were made into soles of the same size, with a thickness of 5 cm, and performance tests were carried out:

[0106] 1. Density test: Test in accordance with HG / T2872-1997;

[0107] 2. Impact resilience test: Tested in accordance with GB / T1681-1991, the impact capacity is 0.5J, the sphere diameter is 15mm, and the impact mass is 100-350g;

[0108] 3. Wear resistance test: A DIN abrasion tester was used for the test. The prepared lightweight, wear-resistant EVA slow-rebound material was made into a cylindrical specimen with a diameter of 16 mm and a thickness of 8 mm. Under the test conditions of a friction distance of 40 mm and a load of 10 N, the transversely moving specimen was rubbed against the gauze on the drum. The wear resistance of the specimen was expressed by the outsole wear volume. The test results are shown in Table 1 below.

[0109] Table 1 Test results

[0110] project <![CDATA[Density g / cm 3 > Impact resilience% <![CDATA[Wear volume (mm 3 )]]> Example 1 0.22 63.5 69.51 Example 2 0.25 64.1 67.85 Example 3 0.23 68.3 68.22 Example 4 0.21 66.8 65.71 Example 5 0.26 67.3 68.57 Comparative Example 1 0.19 49.3 153.21 Comparative Example 2 0.25 60.5 90.56 Comparative Example 3 0.26 63.1 85.54 Comparative Example 4 0.39 59.6 101.14 Comparative Example 5 0.44 77.6 88.71

[0111] Test Example 2

[0112] Anti-slip performance test: The test was conducted in accordance with GB / T 3903.6-2017. The standard environment was 25°C, humidity 50%, distilled water was used as lubricant, the sole load was 50kg, and the sole was fixed on the test platform with the contact surface facing down.

[0113] Drying test: Place directly on dry ceramic tiles.

[0114] Wet slip test: Apply lubricant (1 mL of water) evenly on the surface of the ceramic tile.

[0115] Slowly tilt the platform at a constant speed (e.g., 1° / s) until the sole begins to slide. Record the critical sliding angle (θ) and calculate the static friction coefficient (μ), μ = tanθ, μ ≥ 0.3 meets the standard:

[0116] The test results are shown in Table 2 below.

[0117] Table 2 Test results

[0118]

[0119]

[0120] Test Example 3

[0121] Slow rebound performance test: According to ASTM D3574 standard test, the soles made in the embodiment and comparative example are fixed on the test bench, and a drop hammer (5 kg) is dropped from a set height (50 mm) (H drop ) free fall, measure the rebound height (H rebound ) and impact energy absorption rate:

[0122]

[0123] The test results are shown in Table 3 below.

[0124] Table 3 Test results

[0125] project Rebound rate (%) Example 1 46 Example 2 45 Example 3 49 Example 4 50 Example 5 47 Comparative Example 1 20 Comparative Example 2 45 Comparative Example 3 44 Comparative Example 4 50 Comparative Example 5 29

[0126] As can be seen from the above examples, the present invention provides an EVA slow-rebound anti-skid sole or slipper and a preparation method thereof. It can be seen from the above test data that the addition of thermoplastic elastomers and EVA in the present invention improves the flexibility and micro-roughness of the sole and enhances the grip of the sole. Compared with Example 1, the wear resistance and anti-skid performance of Comparative Example 1, which does not add thermoplastic elastomer, are reduced; the addition of a small amount of fluorinated modifier and nano-silica in the present invention not only improves the anti-skid performance, but also improves the wear resistance of the sole. If too much fluorinated modifier is added, the sole will be too slippery and unsuitable for sports shoes. Without the addition of thermoplastic elastomer, the material itself is soft, the rebound rate decreases, and the rebound is slower, making it unsuitable for use as a sole. The sole or slipper obtained under the formula of the present invention has a rebound rate of between 45% and 50%, and has excellent slow rebound performance. The present invention adds a small amount of SBR rubber powder to make up for the defects of EVA alone as a sole material being relatively soft and having poor rebound resilience. However, SBR rubber powder itself has a certain plasticity. If too much is added, the sole will become hard, the rebound performance will decrease or even no rebound will occur. The hardened sole will also lead to poor wear resistance of the sole, so it is not suitable for sports shoes. The present invention not only maintains the good rebound performance of the sole through the compounding of raw materials, but also further improves the anti-slip performance of the sole, making it safer and more comfortable to use in special sports occasions.

[0127] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An EVA slow rebound anti-skid sole or slipper, characterized in that: Prepared from the following raw materials in parts by weight:

2. The EVA slow rebound anti-skid sole or slipper according to claim 1, characterized in that: The mass content of VA in the EVA is 18-28%.

3. The EVA slow rebound anti-skid sole or slipper according to claim 1 or 2, characterized in that: The thermoplastic elastomer includes one or more of polyurethane elastomer, thermoplastic rubber and hydrogenated styrene elastomer.

4. The EVA slow rebound anti-skid sole or slipper according to claim 3, characterized in that: The particle size of the SBR rubber powder is 80-200 meshes, and the particle size of the nano-silicon dioxide is 50-100 nm.

5. The EVA slow rebound anti-skid sole or slipper according to claim 1, 2 or 4, characterized in that: The fluorinated modifier comprises polytetrafluoroethylene powder, and the particle size of the polytetrafluoroethylene powder is 0.1 to 5 μm.

6. The EVA slow rebound anti-skid sole or slipper according to claim 5, characterized in that: The silane coupling agent comprises KH-550, KH-560 or A-171 silane coupling agent; The cross-linking agent comprises one or more of dicumyl peroxide, di-tert-butyl peroxycumene and tert-amyl peroxy (2-ethylhexyl) carbonate.

7. The method for preparing the EVA slow rebound anti-skid sole or slipper according to any one of claims 1 to 6, characterized in that: The following steps are involved: 1) EVA, a thermoplastic elastomer, SBR rubber powder, and a fluorinated modifier are mixed according to parts by mass and then kneaded, and then nano-silica, a silane coupling agent, and a cross-linking agent are added and further kneaded to obtain a blend, which is granulated and cooled to obtain a foamed granular material; 2) placing the foamed granules in a mold, hot pressing and cooling to obtain a foamed blank; 3) placing the foamed green sheet in a reactor and introducing supercritical gas to perform supercritical foaming, and releasing the pressure after the gas is saturated, thereby obtaining the EVA slow-rebound anti-skid sole or slipper.

8. The method for preparing the EVA slow rebound anti-skid sole or slipper according to claim 7, characterized in that: In the step 1), the banburying temperature is 160-180° C., and the banburying time is 3-10 minutes; The temperature of the hot pressing molding is 130-200° C., and the time of the hot pressing molding is 3-5 minutes.

9. The method for preparing the EVA slow rebound anti-skid sole or slipper according to claim 7 or 8, characterized in that: The supercritical gas includes supercritical CO2, supercritical N2, supercritical ethanol or supercritical propane.

10. The method for preparing the EVA slow rebound anti-skid sole or slipper according to claim 9, characterized in that: The supercritical foaming temperature is 100-200° C., the saturation is carried out at a pressure of 20-30 MPa for 2-4 hours, and the pressure release rate is 5-15 MPa / s.

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