EPR rubber material with ultra-high performance and preparation process thereof

Abstract

The invention relates to the technical field of shoe materials, and provides an ultrahigh-performance EPR rubber material and a preparation process thereof, and the ultrahigh-performance EPR rubber material comprises the following components by weight: 30-40 parts of ethylene propylene diene monomer, 30-40 parts of a styrene-ethylene-butylene-styrene block copolymer, 20-35 parts of an ethylene-vinyl acetate copolymer, 3-4 parts of maleic anhydride graft, 1-3 parts of a coupling agent, 1-3 parts of a coupling agent, and 1-3 parts of an antioxidant. The wear-resistant rubber is prepared from the following components in parts by weight: 0.3-0.45 part of stearic acid, 10-12 parts of an anti-slip agent, 0.6-0.88 part of white stone zinc oxide, 3-4 parts of a wear-resistant agent and 0.6-0.88 part of a vulcanizing agent. The problems that an existing rubber shoe sole is heavy, crisp and prone to aging are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of composite rubber materials, in particular to an EPR rubber material with ultra-high performance and a preparation process thereof. Background Art

[0002] In the field of shoe manufacturing, rubber soles are widely used due to their excellent elasticity and wear resistance. However, traditional rubber materials generally have a high density (usually ≥1.20g / cm³), which makes the soles heavier and affects wearing comfort. At the same time, their wear resistance cannot meet the requirements of high-end footwear (such as sports shoes and outdoor shoes) under long-term and intensive use. The DIN wear resistance value is usually around 80mm. 3 The above factors can easily lead to rapid wear of the soles. Furthermore, the mechanical properties of traditional rubber, such as tensile strength (generally ≤6.0 MPa) and elongation (≤400%), also leave room for improvement, failing to strike a balance between high elasticity and high strength. Traditional rubber materials are widely used in sole manufacturing, but their performance suffers from significant shortcomings.

[0003] As consumers' demands for comfort, durability, and functionality in footwear continue to rise, the market urgently demands new sole materials that combine ultra-low density, ultra-high wear resistance, excellent mechanical properties, and high weather resistance. This is particularly true in the fields of athletic shoes, outdoor shoes, and professional work shoes, which place higher standards on lightweighting, wear resistance, and aging resistance. Currently, there are no mature technical solutions in the industry that can simultaneously meet these multiple high-performance requirements. Therefore, the development of an EPR material and its preparation method that breaks through traditional performance bottlenecks is of great practical significance. Summary of the Invention

[0004] In response to the technical deficiencies of existing rubber soles, such as being heavy, brittle, and easily aged, the present invention provides an ultra-high-performance EPR rubber material and a preparation process thereof. The EPR rubber material of the present invention is lightweight, ultra-high wear-resistant, has strong mechanical properties, and excellent weather resistance.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an ultra-high-performance EPR rubber material, comprising the following components in parts by weight: 30-40 parts by weight of EPDM rubber, 30-40 parts by weight of styrene-ethylene-butylene-styrene block copolymer, 20-35 parts by weight of ethylene vinyl acetate copolymer, 3-4 parts by weight of maleic anhydride grafting agent, 0.3-0.45 parts by weight of stearic acid, 10-12 parts by weight of anti-slip agent, 0.6-0.88 parts by weight of white stone zinc oxide, 3-4 parts by weight of anti-wear agent, and 0.6-0.88 parts by weight of vulcanizing agent.

[0006] Furthermore, the wear-resistant agent is a polyether-modified polysilicone polymer produced by Xiamen United Sino New Materials Co., Ltd.

[0007] Furthermore, the anti-slip agent is a modified polysilicone ether of model GL-41 sold by Quanzhou Shuntai Industry and Trade Co., Ltd.

[0008] The preparation process of the above-mentioned ultra-high performance EPR rubber material comprises the following steps: Step 1: Set the temperature of the internal mixer to 130±5°C, add EPDM rubber, styrene-ethylene-butylene-styrene block copolymer, maleic anhydride grafting, and wear-resistant agent for blending; then set the temperature of the internal mixer to 120±5°C, add ethylene vinyl acetate copolymer, stearic acid, and white stone zinc oxide into the mixing tank for mixing, then beat the material to a temperature of 105±5°C, start sweeping and cleaning the surrounding area, add anti-slip agent, lightly hammer and stir evenly, then hammer again; then beat the material to 115±5°C; then add vulcanizing agent, first lightly stir, then hammer again to mix evenly, and pour the material when the temperature reaches 120±5°C; Step 2: The mixer wheel table is set at 115±5°C, and the material unloaded in step 1 is beaten to a thickness of 5-10mm, then thinned to 1-3mm, then beaten to a thickness of 5-10mm, and then thinned to 1-3mm before discharging; Step 3: Set the temperature of the pelletizer to 100±5℃ and the die head temperature to 80℃. Clean the barrel and trough and cut and pelletize the material discharged from step 2. Step 4: After the granulated material in step 3 is allowed to stand for 23-25 ​​hours, the weighed granules are vulcanized by injection or hydraulic means according to the pre-prepared sole shape by an injection machine. The vulcanization time is set to 300-350 seconds, and the injection machine temperature is set to 175±3°C. After vulcanization, the product is taken out, and the taken out product is trimmed and trimmed. It is allowed to stand for 24 hours, and after finishing, an EPR rubber material product with ultra-high performance is obtained.

[0009] Furthermore, in step 1, after adding the anti-slip agent and hammering, the material is mixed and beaten to 115±5° C., and the material is turned over five times during the process.

[0010] Furthermore, in step 1, the material is turned over three times during the process of adding the vulcanizing agent, first lightly hammering and then hammering hard to mix.

[0011] By adopting the above technical solution, the beneficial effects of the present invention are as follows: the present invention breaks through the limitation of traditional rubber relying on raw materials such as natural rubber, styrene-butadiene rubber and nitrile-butadiene rubber, and the EPR rubber material prepared by combining the EPDM rubber compound formula with precise process control has high elasticity, ultra-high wear resistance and low density, and its performance exceeds that of traditional rubber. The ethylene-vinyl acetate copolymer has the characteristics of high elasticity, chemical resistance, impact resistance and good thermal stability. The EPDM rubber material has excellent aging resistance and physical properties. The two are combined with the styrene-ethylene-butylene-styrene block copolymer (SEBS) with high elasticity and weather resistance. G-1651) is combined with an accelerator (stearic acid) and a vulcanizing agent to produce a product with low density, high elasticity and high physical properties. At the same time, anti-wear agents, anti-slip agents, white stone zinc oxide and maleic anhydride grafted ST-3 are added during the reaction process to further significantly improve the physical properties and wear resistance and anti-slip properties of the product. While its physical properties and wear resistance far exceed the industry level, it also has low density, high elasticity, high weather resistance and other properties. This is achieved through the reasonable and optimized proportion selection of EPDM rubber, styrene-ethylene-butylene-styrene block copolymer and ethylene-vinyl acetate copolymer. The lightweight of the prepared product makes the density of the prepared material ≤0.92g / cm³, achieving lightweight soles, ultra-high wear resistance, strong mechanical properties and excellent weather resistance. The key indicators far exceed the industry level, solving the bottleneck of traditional rubber being "heavy, brittle and easy to age", and achieving a breakthrough in the performance of EPR rubber materials; through the design of a multi-material blending system and the regulation of the vulcanization process, it has achieved a breakthrough in the limitations of traditional rubber tensile strength (≤6.0MPa) and elongation (≤400%), making the tensile strength ≥8.0MPa and the elongation ≥550%, while improving the trouser-type tear (≥8.0N / mm) and C-type tear (≥30N / mm) strengths, achieving the synergistic optimization of high elasticity and high strength, and greatly improving the toughness; through formula optimization and process improvement, the DIN wear resistance value is controlled at 30mm 3 The following significantly improves the wear resistance of the material surface; by adding white stone zinc oxide for weathering modification and optimizing the cross-linking structure, the ozone aging level reaches the highest level 5, and the ultraviolet and solar irradiation levels are both ≥ 4, significantly extending the service life of the material. In the preparation process of the present invention, the EPR rubber material is prepared by a process flow of first performing a granulation step and then a vulcanization step (wherein the vulcanization step can be a one-time injection molding vulcanization process or a traditional hydraulic vulcanization molding process), so that it has ultra-high wear resistance, strong mechanical properties and excellent weather resistance; optimize the processing technology, by improving the process flow, and by adopting a new operating mode for the internal mixer and the mixing mill to solve the problems of uneven material dispersion and low cross-linking efficiency in the traditional process, thereby improving production efficiency and product consistency, and providing reliable technical support for large-scale manufacturing. DETAILED DESCRIPTION

[0012] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0013] The raw materials, trade names and equipment models used in the examples are shown in the following table:

[0014] Test parameter indicators: Hardness: Tested according to GB / T3903.4-2017 standard; Density: tested according to GB / T 533-2008 standard; Wear resistance: tested according to GB / T 9867-2008 standard; Anti-slip: tested according to GB / T 3903.6-2017 standard; Tensile strength: tested according to GB / T 3903.22-2008 standard; Elongation: tested according to GB / T 3903.22-2008 standard; Tear strength: tested according to GB / T 3903.12-2021 standard.

[0015] Ingredients and quantities of Example 1, Example 2, and Example 3 Example 1

[0016] The preparation process of the ultra-high performance EPR rubber material using the ratio of the components in Example 1 in the above table includes the following steps: Step 1: Set the temperature of the internal mixer to 130°C, first add EPDM 30.86PHR, styrene-ethylene-butylene-styrene block copolymer G-1651 30.86PHR, maleic anhydride grafted ST-3 3.69PHR, and wear-resistant agent 3.69PHR for blending; then set the temperature of the internal mixer to 120°C, then add ethylene vinyl acetate copolymer 7350 34.28PHR, stearic acid ST1842 0.37PHR, and white stone zinc oxide 0.74PHR into the mixing tank for mixing, and mix the materials in the internal mixer until the temperature reaches 105°C, then start sweeping the powder and cleaning the surroundings; then add anti-slip agent GL-41 4.9PHR, lightly hammer and stir evenly, then hammer again; then mix the materials in the internal mixer until the temperature reaches 115°C, and turn the materials over five times during the mixing process; then add vulcanizing agent BIPB. 0.74PHR, first light hammer stirring, then heavy hammer mixing, stirring to 120℃ when pouring out the material, the material is turned over three times during the light hammer and heavy hammer mixing process; Step 2: The mixer wheel temperature is set at 115°C, and the material unloaded in step 1 is beaten into a thickness of 8mm, then thinned to 3mm, then thickened to 7mm, and then thinned to 2mm before discharging; Step 3: Set the temperature of the pelletizer to 100°C and the die head to 80°C. Clean the barrel and trough and cut and pelletize the material discharged from step 2. Step 4: After the granulated material in step 3 is allowed to stand for 24 hours, the weighed granules are vulcanized by injection or hydraulic pressure. The vulcanization time is set to 300 seconds and the injection molding machine temperature is set to 177°C. After vulcanization, the product is taken out; the taken out product is trimmed and left to stand for 24 hours. After finishing, an EPR rubber material product with ultra-high performance is obtained.

[0017] The obtained ultra-high performance EPR rubber material was tested according to the above standards, and the test results are as follows: Hardness: 63C; Density: 0.83g / cm³; Tensile strength: 8.7Mpa; Elongation: 556%; Trouser tearing strength: 11N / mm; C-type tearing strength: 35N / mm; DIN wear resistance: 29mm 3 ; Ozone: Level 5; UV: Level 4 Sun lamp: Level 4 MARKII anti-slip: 0.46. Example 2

[0018] The preparation process of the ultra-high performance EPR rubber material using the ratio of the components in Example 2 in the above table includes the following steps: Step 1: Set the internal mixer temperature to 130°C and add 38.86 PHR of EPDM, 38.86 PHR of styrene-ethylene-butylene-styrene block copolymer G-1651, 33.69 PHR of maleic anhydride grafted ST-3, and 3.69 PHR of anti-wear agent to the mixer. Set the internal mixer temperature to 120°C and add 22.28 PHR of ethylene vinyl acetate copolymer 7350, 20.37 PHR of stearic acid ST184, and 0.74 PHR of white stone zinc oxide to the mixing tank for mixing. Mix the mixture to 105°C and begin dusting and cleaning the surroundings. Add 4.9 PHR of anti-slip agent GL-41 and gently hammer until uniform, then hammer again. Mix the material in a mixer until the temperature reaches 115℃, turn the material over five times during the mixing process, add 0.74PHR of vulcanizing agent BIPB, stir with a light hammer first, then with a heavy hammer to mix evenly, and pour the material when the temperature reaches 120℃, turn the material over three times during the mixing process of light hammer and heavy hammer; Step 2: The mixer wheel temperature is set at 115°C, and the material unloaded in step 1 is beaten once to a thickness of 9mm, then thinned once to 2mm, then beaten once to a thickness of 7mm, and then thinned once to 2mm to discharge; Step 3: Set the temperature of the pelletizer to 100°C and the die head to 80°C. Clean the barrel and trough and cut and pelletize the material discharged from step 2. Step 4: After the granulated material in step 3 is allowed to stand for 24 hours, the weighed granules are vulcanized by injection or hydraulic pressure. The vulcanization time is set to 320 seconds and the injection molding machine temperature is set to 175°C. After vulcanization, the product is taken out; the taken out product is trimmed and left to stand for 24 hours. After finishing, an EPR rubber material product with ultra-high performance is obtained.

[0019] The obtained ultra-high performance EPR rubber material was tested according to the above standards, and the test results are as follows: Hardness: 66C; Density: 0.90g / cm³; Tensile strength: 8.4Mpa; Elongation: 574%; Trouser tearing strength: 12N / mm; C-type tearing strength: 32N / mm; DIN wear resistance: 21mm 3 ; Ozone: Level 5; UV: Level 4 Sun lamp: Level 4 MARKII anti-slip: 0.46. Example 3

[0020] The preparation process of the ultra-high performance EPR rubber material using the ratio of the components in Example 3 in the above table includes the following steps: Step 1: Set the internal mixer temperature to 130°C and add 34.86 PHR of EPDM, 30.86 PHR of styrene-ethylene-butylene-styrene block copolymer G-1651, 33.69 PHR of maleic anhydride grafted ST-3, and 3.69 PHR of anti-wear agent for blending. Set the internal mixer temperature to 120°C and add 34.28 PHR of ethylene vinyl acetate copolymer 7350, 0.37 PHR of stearic acid ST1842, and 0.74 PHR of white stone zinc oxide to the mixing tank for mixing. Mix the mixture to 105°C and begin dusting and cleaning the surroundings. Add 4.9 PHR of anti-slip agent GL-41 and gently hammer until evenly mixed, then hammer again. Mix the material in a mixer until the temperature reaches 115℃, turn the material over five times during the mixing process, add 0.74PHR of vulcanizing agent BIPB, stir with a light hammer first, then with a heavy hammer to mix evenly, and pour the material when the temperature reaches 120℃, turn the material over three times during the mixing process of light hammer and heavy hammer; Step 2: The mixer wheel temperature is set at 115°C, and the material unloaded in step 1 is beaten to a thickness of 10mm, then to a thickness of 3mm, then to a thickness of 8mm, and finally to a thickness of 1mm before discharging; Step 3: Set the temperature of the pelletizer to 100°C and the die head to 80°C. Clean the barrel and trough and cut and pelletize the material discharged from step 2. Step 4: After the granulated material in step 3 is allowed to stand for 24 hours, the weighed granules are vulcanized by injection or hydraulic pressure. The vulcanization time is set to 350 seconds, the injection molding machine temperature is set to 174°C, and the granules are taken out after vulcanization. The taken-out product is trimmed and left to stand for 24 hours. After finishing, an EPR rubber material product with ultra-high performance is obtained.

[0021] The obtained ultra-high performance EPR rubber material was tested according to the above standards, and the test results are as follows: Hardness: 64C; Density: 0.86g / cm³; Tensile strength: 8.2Mpa; Elongation: 555%; Trouser tearing strength: 10N / mm; C-type tearing strength: 36N / mm; DIN wear resistance: 28mm 3 ; Ozone: Level 5; UV: Level 4 Sun lamp: Level 4 MARKII anti-slip: 0.49.

[0022] Comparative Example 1 The ingredients and amounts of Comparative Example 1:

[0023] Comparative Example 1 Processing Technology: Step 1: Put 12PHR of cis-butyl rubber BR1208, 20PHR of nitrile rubber 2203, and 20.5PHR of nitrile rubber 7030 into an internal mixer and plasticate for 90 seconds at a machine temperature of 90°C; Step 2: Lift the hammer and pour in 0.7 PHR of accelerator DM, 1.6 PHR of antioxidant OH3, 3.7 PHR of zinc carbonate, 0.4 PHR of stearic acid, and 4 PHR of one-third of white smoke, and masticate for 60 seconds at 110°C. Step 3: Lift the hammer to clean, then pour in one-third of white smoke 4PHR and refine for 60 seconds at a temperature of 115°C; Step 4: Lift the hammer to clean, pour in the remaining white smoke plastic 4PHR and refine for 60 seconds at 125°C; Step 5: Lift the hammer to clean, then lower it to plasticize, repeat three times, 120 seconds, temperature 135°C; Step 6: Pour the masticated rubber into the turbine and continue masticating for 180 seconds, roll it up, hang it on a rack to dry, let it cool, then weigh it, pack it in PE bags, and store it for 24 hours before use; Step 7: Add 1.2PHR of insoluble sulfur as a vulcanizing agent to the stored rubber material in a mixing mill and mix evenly, then roll it up into sheets; dry it for 4 hours and cut the material for later use; Step 8: The temperature of the rubber vulcanization machine is 160°C, the pressure is 155 kg / cm2, the exhaust is three times, and the vulcanization time is 320 seconds.

[0024] The finished product was tested and its performance parameters are shown in the following table: Test results: Hardness A: 65; Specific gravity g / cm³: 1.19; Wear resistance: 120 mm 3 ; Tensile strength MPa: 7; Elongation %: 410; Tear strength N / mm: 8; Ozone level: 3.

[0025] Ozone test conditions (temperature: 40°C; humidity: 65% RH; ozone concentration: 50 pphm; time: 6 hours).

[0026] Final measured values ​​according to the three examples: density ≤ 0.92 g / cm³, DIN wear resistance: ≤ 30 mm 3, and other physical properties and reliability reach the industry's top level. While reducing density, the wear resistance, mechanical properties, and weather resistance are simultaneously improved, avoiding the "loss of one thing for another" problem in traditional modifications and meeting the stringent requirements of high-end footwear materials for multiple properties. The above-mentioned formula and process are key factors. The reasonable combination of the overall formula is the basis and guarantee for achieving the overall performance of the product. The rubber insole material of Comparative Example 1 is an existing optimized formula and product. Obviously, the density, mechanical properties, aging properties and other properties of existing rubber composite soles cannot achieve effective balance and performance enhancement, which is the performance limitation of composite materials with rubber as the main material.

[0027] In the above embodiment, the control of the mixing machine is preferably set as follows: the material unloaded in step 1 is thickened by 5-10mm once, then thinned by 1-3mm once, then thickened by 5-10mm once, and then thinned by 1-3mm once. When the vulcanization process is carried out in step 4, the vulcanization time is preferably set to 300-350 seconds when the injection molding vulcanization process or the traditional oil pressure vulcanization molding process is adopted, and the injection machine temperature is set to 175±3°C. The temperature setting of each step of the internal mixer of step 1, the mixing machine of step 2, and the granulator of step 3 can be preferably set at a temperature of ±5°C according to Example 1 to Example 3.

[0028] The weight ratio of each raw material in the present invention is preferably as follows: 30-40 parts by weight of EPDM rubber, 30-40 parts by weight of styrene-ethylene-butylene-styrene block copolymer, 20-35 parts by weight of ethylene vinyl acetate copolymer, 3-4 parts by weight of maleic anhydride grafted copolymer, 0.3-0.45 parts by weight of stearic acid, 10-12 parts by weight of anti-slip agent, 0.6-0.88 parts by weight of white stone zinc oxide, 3-4 parts by weight of anti-wear agent, and 0.6-0.88 parts by weight of vulcanizing agent.

[0029] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An EPR rubber material with ultra-high performance, characterized by: The invention comprises the following components in parts by weight: 30-40 parts by weight of EPDM rubber, 30-40 parts by weight of styrene-ethylene-butylene-styrene block copolymer, 20-35 parts by weight of ethylene vinyl acetate copolymer, 3-4 parts by weight of maleic anhydride grafting agent, 0.3-0.45 parts by weight of stearic acid, 10-12 parts by weight of anti-slip agent, 0.6-0.88 parts by weight of white stone zinc oxide, 3-4 parts by weight of anti-wear agent, and 0.6-0.88 parts by weight of vulcanizing agent.

2. The ultra-high performance EPR rubber material according to claim 1, characterized in that: The anti-wear agent is a polyether modified polysilicone polymer produced by Xiamen United Xinnuo New Materials Co., Ltd.

3. The ultra-high performance EPR rubber material according to claim 1, characterized in that: The anti-slip agent is a modified polysilicone ether of model GL-41 sold by Quanzhou Shuntai Industry and Trade Co., Ltd.

4. The process for preparing the ultra-high performance EPR rubber material according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: Set the temperature of the internal mixer to 130±5°C, add EPDM rubber, styrene-ethylene-butylene-styrene block copolymer, maleic anhydride grafting, and wear-resistant agent for blending; then set the temperature of the internal mixer to 120±5°C, add ethylene vinyl acetate copolymer, stearic acid, and white stone zinc oxide into the mixing tank for mixing, then beat the material to a temperature of 105±5°C, start sweeping and cleaning the surrounding area, add anti-slip agent, lightly hammer and stir evenly, then hammer again; then beat the material to 115±5°C; then add vulcanizing agent, first lightly stir, then hammer again to mix evenly, and pour the material when the temperature reaches 120±5°C; Step 2: The mixer wheel table is set at 115±5°C, and the material unloaded in step 1 is beaten to a thickness of 5-10mm, then thinned to 1-3mm, then beaten to a thickness of 5-10mm, and then thinned to 1-3mm before discharging; Step 3: Set the temperature of the pelletizer to 100±5℃ and the die head temperature to 80℃. Clean the barrel and trough and cut and pelletize the material discharged from step 2. Step 4: After the granulated material in step 3 is allowed to stand for 23-25 ​​hours, the weighed granules are vulcanized by injection or hydraulic means according to the pre-prepared sole shape by an injection machine. The vulcanization time is set to 300-350 seconds, and the injection machine temperature is set to 175±3°C. After vulcanization, the product is taken out, and the taken out product is trimmed and trimmed. It is allowed to stand for 24 hours, and after finishing, an EPR rubber material product with ultra-high performance is obtained.

5. The process for preparing an ultra-high performance EPR rubber material according to claim 4, wherein: In step 1, after adding the anti-slip agent and hammering, the material is mixed and beaten to 115±5℃, and the material is turned over five times during the process.

6. The process for preparing an ultra-high performance EPR rubber material according to claim 4, wherein: In step 1, after adding the vulcanizing agent, stir lightly with a hammer and then stir hard, turning the material over three times during the mixing process.

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