Wear-resistant non-slip EVA shoe sole material and preparation process thereof

Abstract

The application relates to the technical field of EVA, and discloses a wear-resistant and skid-resistant EVA shoe sole material and a preparation process thereof.The wear-resistant and skid-resistant EVA shoe sole material comprises, by weight, 100 parts of ethylene-vinyl acetate copolymer, 1-4 parts of nylon fiber, 0.2-1 part of VA-SSS-based polyamide copolymer, 0.5-0.8 parts of a crosslinking agent, 2.2-3 parts of a foaming agent and the like.The VA-SSS-based polyamide copolymer can improve the compatibility of the nylon fiber in the EVA, makes the nylon fiber play a better reinforcing role, improves the interfacial force between the montmorillonite and the EVA, improves the dispersity of the montmorillonite, the montmorillonite is not prone to agglomeration in the EVA shoe sole material, the uniformly dispersed montmorillonite has a good reinforcing effect, and the wear resistance, skid resistance and tear strength of the material are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of EVA, in particular to a wear-resistant and slip-resistant EVA sole material and a preparation process thereof. BACKGROUND

[0002] The current sole material is mainly EVA, polyvinyl chloride, polyurethane and other foaming materials. Among them, EVA (ethylene-vinyl acetate copolymer) has good foaming property, good water resistance, no odor, excellent resilience, and is widely used in shoe materials, hot melt adhesive, film, sound insulation material and other aspects. The traditional EVA has poor wear resistance, poor mechanical properties such as tear strength, and therefore it is necessary to improve the wear resistance, slip resistance, mechanical strength and other properties of EVA, so that EVA has better practical application in sole materials and other aspects.

[0003] Montmorillonite is a natural silicate mineral with wide sources and low cost. After modification, montmorillonite has good dispersion performance and is widely used in plastics, fibers, rubber and other high polymer materials, which can improve the impact strength, wear resistance, heat resistance and other properties of the materials. The modifiers for montmorillonite include sodium dodecyl benzene sulfonate, silane coupling agent and polyacrylic acid. Chinese patent CN110591214B discloses a fluorine-containing organic montmorillonite modified EVA foaming material and a preparation method thereof. The fluorine-containing organic montmorillonite, a styrene-based thermoplastic elastomer, a glycidyl methacrylate grafted EVA compatibilizer, and EVA are blended and foamed to obtain a foaming product with excellent wear resistance and slip resistance. However, the preparation method of the fluorine-containing organic montmorillonite in the patent is relatively complex, and the tear strength of the EVA material is not improved. Nylon fiber is a synthetic fiber with good wear resistance and high mechanical strength. The present application aims to improve the mechanical strength and wear resistance of EVA sole material by using montmorillonite and nylon fiber. SUMMARY

[0004] The present application solves the problem of poor mechanical strength, wear resistance and other properties of EVA sole material.

[0005] The technical solution of the present application is a wear-resistant and slip-resistant EVA sole material, which comprises, by weight, 100 parts of ethylene-vinyl acetate copolymer, 1-4 parts of nylon fiber, 0.2-1 part of VA-SSS-based polyamide copolymer, 2-8 parts of filler, 0.6-1.2 parts of auxiliary agent, 0.5-0.8 parts of crosslinking agent, 2.2-3 parts of foaming agent, 0.6-0.8 parts of stearic acid, and 0.4-0.7 parts of zinc stearate.

[0006] Further, the filler is montmorillonite, the auxiliary agent is zinc oxide, the crosslinking agent is dicumyl peroxide, and the foaming agent is azodicarbonamide.

[0007] Further, the preparation process of the wear-resistant and slip-resistant EVA shoe sole material is as follows: ethylene-vinyl acetate copolymer, nylon fiber, VA-SSS-based polyamide copolymer, filler, auxiliary agent, stearic acid, and zinc stearate are added to an open mill, the roller shaft is controlled at 90-100℃, the crosslinking agent is added after mixing, and the mixing is continued; then the foaming agent is added, and the sheet is discharged after mixing; finally, the mold foaming is carried out in a vulcanizing machine, the temperature is 175-185℃, the pressure is 15-20MPa, the time is 6-8min, the material is discharged, and the wear-resistant and slip-resistant EVA shoe sole material is obtained after cooling.

[0008] Further, the preparation process of the VA-SSS-based polyamide copolymer is as follows:

[0009] (1) According to the weight fraction, toluene, 100 parts of vinyl acetate (VA), 10-25 parts of 4-sodium styrene sulfonate (SSS), 1.6-1.8 parts of S,S'-di(α,α'-methyl-α"-acetic acid) trithiocarbonate (structure formula ), 0.14-0.2 parts of azobisisobutyronitrile are added to the reaction container, heated to 60-75℃ in a nitrogen atmosphere, reacted for 12-18h, diluted with ethanol, washed with ethanol after filtration, and dried to obtain carboxyl-terminated (vinyl acetate-styrene sulfonate)

[0010] copolymer. The reaction formula is as follows:

[0011]

[0012] (2) According to the weight fraction, N-methyl pyrrolidone, 100 parts of carboxyl-terminated (vinyl acetate-styrene sulfonate) copolymer, 6.4-8.5 parts of diamine compound, 31-35 parts of pyridine, 26-32 parts of triphenyl phosphite, and 15-18 parts of calcium chloride are added to the reaction container, stirred and reacted at 110-130℃ for 18-24h in a nitrogen atmosphere, diluted with ethanol, washed with ethanol and water after filtration, and dried to obtain the VA-SSS-based polyamide copolymer. The reaction formula is as follows:

[0013]

[0014] Further, the diamine compound is 1,4-butanediamine, 1,5-pentanediamine, or 1,6-hexanediamine.

[0015] Technical effects: the application uses S, S'-di (alpha, alpha'-methyl-alpha"-acetic acid) trithiocarbonate as a RAFT chain transfer agent, azobisisobutyronitrile as an initiator, initiates the reversible addition-fragmentation chain transfer polymerization of ethylene vinyl acetate and 4-styrene sodium sulfonate, to obtain a carboxyl-terminated (ethylene vinyl acetate-styrene sodium sulfonate) copolymer, then uses triphenyl phosphite and pyridine as a condensing agent, and 1,6-hexanediamine diamine compound for amidation polymerization to obtain a VA-SSS-based polyamide copolymer. Finally, with montmorillonite and nylon fiber as reinforcing agents, ethylene-vinyl acetate copolymer EVA as a foaming base, dicumyl peroxide as a crosslinking agent, and azodicarbonamide as a foaming agent, the wear-resistant and slip-resistant EVA shoe sole material is obtained through blending and foaming.

[0016] The main chain of the VA-SSS-based polyamide copolymer contains the same polyvinyl acetate block molecular chain as EVA, and the main chain contains an amide bond structure unit, which has similar polarity with the polyamide molecular chain of nylon fiber, so that the VA-SSS-based polyamide copolymer plays a role of a compatibilizer, improves the compatibility of the nylon fiber in the EVA, and makes the nylon fiber play a better reinforcing role, which is beneficial to improve the wear resistance, slip resistance and mechanical strength of the EVA shoe sole material.

[0017] The side chain of the VA-SSS-based polyamide copolymer contains a sodium sulfonate group, which can form interaction with the surface of montmorillonite, play a role of a dispersing agent, improve the interfacial force between montmorillonite and EVA, and improve the dispersibility of montmorillonite, so that the montmorillonite is not easy to agglomerate in the EVA shoe sole material, and the uniformly dispersed montmorillonite has a good reinforcing effect, further improves the wear resistance, slip resistance and mechanical strength of the material, shows a higher dry friction coefficient and tear strength, and reduces the wear volume of the shoe sole material. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and beneficial effects of the application more clear, the preferred embodiments of the application will be described in detail below, so as to facilitate the understanding of the skilled in the art.

[0019] The following ethylene-vinyl acetate copolymer, model LG 28150, is purchased from Shanghai Ousuo Plastic Co., Ltd. Montmorillonite, average particle size 1250 mesh, is purchased from Shijiazhuang Hualang Mineral Products Trade Co., Ltd. Nylon fiber, length 6mm, is purchased from Nantong Yiheng New Material Technology Co., Ltd.

[0020] Example 1:

[0021] (1) Into a reaction vessel was added 80 mL of toluene, 20 g of vinyl acetate, 3.5 g of sodium 4-styrenesulfonate, 0.32 g of S,S'-bis(a,a'-methyl-a"-acetic acid)trithiocarbonate, 35 mg of azobisisobutyronitrile, heated to 75°C under a nitrogen atmosphere, and reacted for 12 hours. The solution was diluted with ethanol, filtered, washed with ethanol, and dried to obtain a carboxyl-terminated (vinyl acetate-sodium 4-styrenesulfonate) copolymer.

[0022] (2) Into a reaction vessel was added 250 mL of N-methylpyrrolidone, 20 g of carboxyl-terminated (vinyl acetate-sodium 4-styrenesulfonate) copolymer, 1.7 g of 1,6-hexanediamine, 6.7 g of pyridine, 5.9 g of triphenyl phosphite, 3.2 g of calcium chloride, stirred at 120°C under a nitrogen atmosphere for 24 hours. The solution was diluted with ethanol, filtered, washed with ethanol and water, and dried to obtain a VA-SSS-based polyamide copolymer.

[0023] (3) Into an open mill were added 5 kg of ethylene-vinyl acetate copolymer, 50 g of nylon fiber, 10 g of VA-SSS-based polyamide copolymer, 100 g of filler montmorillonite, 48 g of auxiliary zinc oxide, 40 g of stearic acid, and 20 g of zinc stearate, and the roll shaft was controlled at 100°C. After mixing, 34 g of a crosslinking agent, dicumyl peroxide, was added and mixing was continued. Then, 110 g of a blowing agent, azodicarbonamide, was added, and after mixing, the sheet was discharged. Finally, the material was subjected to mold foaming in a curing press at a temperature of 180°C, a pressure of 15 MPa, and a time of 8 minutes, discharged, and cooled to obtain an abrasion-resistant and slip-resistant EVA sole material.

[0024] Comparative Example 1, the difference between this comparative example and Example 1 is that the nylon fiber and the VA-SSS-based polyamide copolymer were not added.

[0025] (1) Into an open mill were added 5 kg of ethylene-vinyl acetate copolymer, 100 g of filler montmorillonite, 48 g of auxiliary zinc oxide, 40 g of stearic acid, and 20 g of zinc stearate, and the roll shaft was controlled at 100°C. After mixing, 34 g of a crosslinking agent, dicumyl peroxide, was added and mixing was continued. Then, 110 g of a blowing agent, azodicarbonamide, was added, and after mixing, the sheet was discharged. Finally, the material was subjected to mold foaming in a curing press at a temperature of 180°C, a pressure of 15 MPa, and a time of 8 minutes, discharged, and cooled to obtain an EVA sole material.

[0026] Comparative Example 2, the difference between this comparative example and Example 1 is that the nylon fiber was not added.

[0027] (1) 5 kg of ethylene-vinyl acetate copolymer, 50 g of nylon fiber, 48 g of zinc oxide, 40 g of stearic acid, and 20 g of zinc stearate were added to an open mill, and the roll shaft was controlled at 100°C. After mixing, 34 g of dicumyl peroxide was added, and mixing was continued. Then, 110 g of azodicarbonamide was added, and after mixing, the sheet was discharged. Finally, molding and foaming were performed in a vulcanizing machine at a temperature of 180°C, a pressure of 15 MPa, and a time of 8 min, and the material was discharged, cooled, and an EVA shoe sole material was obtained.

[0028] Comparative Example 3: The difference between this comparative example and Example 1 is that no montmorillonite and no VA-SSS-based polyamide copolymer were added.

[0029] (1) 5 kg of ethylene-vinyl acetate copolymer, 50 g of nylon fiber, 48 g of zinc oxide, 40 g of stearic acid, and 20 g of zinc stearate were added to an open mill, and the roll shaft was controlled at 100°C. After mixing, 34 g of dicumyl peroxide was added, and mixing was continued. Then, 110 g of azodicarbonamide was added, and after mixing, the sheet was discharged. Finally, molding and foaming were performed in a vulcanizing machine at a temperature of 180°C, a pressure of 15 MPa, and a time of 8 min, and the material was discharged, cooled, and an EVA shoe sole material was obtained.

[0030] Comparative Example 4: The difference between this comparative example and Example 1 is that no montmorillonite was added.

[0031] (1) 5 kg of ethylene-vinyl acetate copolymer, 50 g of nylon fiber, 48 g of zinc oxide, 40 g of stearic acid, and 20 g of zinc stearate were added to an open mill, and the roll shaft was controlled at 100°C. After mixing, 34 g of dicumyl peroxide was added, and mixing was continued. Then, 110 g of azodicarbonamide was added, and after mixing, the sheet was discharged. Finally, molding and foaming were performed in a vulcanizing machine at a temperature of 180°C, a pressure of 15 MPa, and a time of 8 min, and the material was discharged, cooled, and an EVA shoe sole material was obtained.

[0032] Comparative Example 5: The difference between this comparative example and Example 1 is that no VA-SSS-based polyamide copolymer was added.

[0033] (1) 5 kg of ethylene-vinyl acetate copolymer, 50 g of nylon fiber, 48 g of zinc oxide, 40 g of stearic acid, and 20 g of zinc stearate were added to an open mill, and the roll shaft was controlled at 100°C. After mixing, 34 g of dicumyl peroxide was added, and mixing was continued. Then, 110 g of azodicarbonamide was added, and after mixing, the sheet was discharged. Finally, molding and foaming were performed in a vulcanizing machine at a temperature of 180°C, a pressure of 15 MPa, and a time of 8 min, and the material was discharged, cooled, and an EVA shoe sole material was obtained.

[0034] Comparative Example 6: The difference between this comparative example and Example 1 is that styrene is used instead of sodium 4-styrenesulfonate when preparing the copolymer.

[0035] (1) Into a reaction vessel were added 80 mL of toluene, 20 g of vinyl acetate, 3.5 g of styrene, 0.32 g of S,S'-bis(a,a'-methyl-a"-acetic acid)trithiocarbonate, 35 mg of azobisisobutyronitrile, heated to 75°C under a nitrogen atmosphere, and reacted for 12 h. Ethanol was added to dilute the solution, which was filtered, washed with ethanol, and dried to obtain a carboxyl-terminated (vinyl acetate-styrene) copolymer.

[0036] (2) Into a reaction vessel were added 250 mL of N-methylpyrrolidone, 20 g of the carboxyl-terminated (vinyl acetate-styrene) copolymer, 1.7 g of 1,6-hexanediamine, 6.7 g of pyridine, 5.9 g of triphenyl phosphite, and 3.2 g of calcium chloride. After stirring, the mixture was reacted for 24 h at 120°C under a nitrogen atmosphere. Ethanol was added to dilute the solution, which was filtered, washed with ethanol and water, and dried to obtain a VA-St-based polyamide copolymer.

[0037] (3) Into an open mill were added 5 kg of ethylene-vinyl acetate copolymer, 50 g of nylon fiber, 10 g of the VA-SSS-based polyamide copolymer, 100 g of filler montmorillonite, 48 g of auxiliary zinc oxide, 40 g of stearic acid, and 20 g of zinc stearate. After mixing at a roll shaft temperature of 100°C, 34 g of a crosslinking agent, dicumyl peroxide, was added and mixing was continued. Then, 110 g of a blowing agent, azodicarbonamide, was added and mixing was continued until the mixture was sheeted. Finally, the mixture was subjected to mold foaming in a vulcanizing machine at a temperature of 180°C, a pressure of 15 MPa, and a time of 8 min. The product was discharged, cooled, and an EVA sole material was obtained.

[0038] Comparative Example 7: The difference between this comparative example and Example 1 is that sodium 4-styrenesulfonate is used instead of vinyl acetate when preparing the copolymer.

[0039] (1) Into a reaction vessel were added 80 mL of toluene, 23.5 g of sodium 4-styrenesulfonate, 0.32 g of S,S'-bis(a,a'-methyl-a"-acetic acid)trithiocarbonate, and 35 mg of azobisisobutyronitrile. The mixture was heated to 75°C under a nitrogen atmosphere and reacted for 12 h. Ethanol was added to dilute the solution, which was filtered, washed with ethanol, and dried to obtain a carboxyl-terminated sodium 4-styrenesulfonate copolymer.

[0040] (2) Into a reaction vessel was added 250 mL of N-methyl pyrrolidone, 20 g of sodium carboxyl terminated styrene sulfonate copolymer, after stirring, 1.7 g of 1,6-hexanediamine, 6.7 g of pyridine, 5.9 g of triphenyl phosphite, 3.2 g of calcium chloride, under a nitrogen atmosphere, stirred at 120 °C for 24 h, ethanol was added to the solution to dilute, after filtration, washed with ethanol, water, and dried to obtain a SSS based polyamide copolymer.

[0041] (3) Into a two roll mill was added 5 kg of ethylene-vinyl acetate copolymer, 50 g of nylon fiber, 10 g of SSS based polyamide copolymer, 100 g of filler montmorillonite clay, 48 g of zinc oxide, 40 g of stearic acid, 20 g of zinc stearate, the roll temperature was controlled at 100 °C, after mixing, 34 g of crosslinking agent dicumyl peroxide was added and mixing was continued; then 110 g of foaming agent azodicarbonamide was added and mixing was continued, after which the mixture was sheeted off; finally, the mixture was subjected to compression molding and foaming in a curing press at a temperature of 180 °C, a pressure of 15 MPa, and a time of 8 min, the product was discharged, cooled, and an EVA shoe sole material was obtained.

[0042] Example 2:

[0043] (1) Into a reaction vessel was added 80 mL of toluene, 20 g of vinyl acetate, 5 g of sodium 4-styrene sulfonate, 0.34 g of S,S'-bis(a,a'-methyl-a"-acetic acid) trithiocarbonate, 40 mg of azobisisobutyronitrile, under a nitrogen atmosphere, heated to 60 °C for 18 h, ethanol was added to the solution to dilute, after filtration, washed with ethanol, and dried to obtain a carboxyl terminated (vinyl acetate-styrene sulfonate) copolymer.

[0044] (2) Into a reaction vessel was added 250 mL of N-methyl pyrrolidone, 20 g of carboxyl terminated (vinyl acetate-styrene sulfonate) copolymer, after stirring, 1.28 g of 1,4-butanediamine, 7 g of pyridine, 5.2 g of triphenyl phosphite, 3 g of calcium chloride, under a nitrogen atmosphere, stirred at 130 °C for 18 h, ethanol was added to the solution to dilute, after filtration, washed with ethanol, water, and dried to obtain a VA-SSS based polyamide copolymer.

[0045] (3) Into a two roll mill was added 5 kg of ethylene-vinyl acetate copolymer, 120 g of nylon fiber, 10 g of VA-SSS based polyamide copolymer, 250 g of filler montmorillonite clay, 60 g of zinc oxide, 33 g of stearic acid, 25 g of zinc stearate, the roll temperature was controlled at 90 °C, after mixing, 25 g of crosslinking agent dicumyl peroxide was added and mixing was continued; then 150 g of foaming agent azodicarbonamide was added and mixing was continued, after which the mixture was sheeted off; finally, the mixture was subjected to compression molding and foaming in a curing press at a temperature of 175 °C, a pressure of 20 MPa, and a time of 8 min, the product was discharged, cooled, and a wear resistant and slip resistant EVA shoe sole material was obtained.

[0046] Example 3:

[0047] (1) Into a reaction vessel, 70 mL of toluene, 20 g of vinyl acetate, 2 g of sodium 4-styrene sulfonate, 0.32 g of S,S'-bis(a,a'-methyl-a"-acetic acid) trithiocarbonate, 28 mg of azobisisobutyronitrile were added, heated to 65°C under nitrogen atmosphere, and reacted for 12 hours. Ethanol was added to dilute the solution, and after filtration, the product was washed with ethanol and dried to obtain a carboxyl-terminated (vinyl acetate-sodium 4-styrene sulfonate) copolymer.

[0048] (2) Into a reaction vessel, 250 mL of N-methylpyrrolidone, 20 g of carboxyl-terminated (vinyl acetate-sodium 4-styrene sulfonate) copolymer were added, and after stirring, 1.52 g of 1,5-pentanediamine, 6.2 g of pyridine, 6.4 g of triphenyl phosphite, and 3.6 g of calcium chloride were added. The reaction was stirred at 110°C for 24 hours under nitrogen atmosphere. Ethanol was added to dilute the solution, and after filtration, the product was washed with ethanol and water and dried to obtain a VA-SSS-based polyamide copolymer.

[0049] (3) 5 kg of ethylene-vinyl acetate copolymer, 200 g of nylon fiber, 10 g of VA-SSS-based polyamide copolymer, 400 g of filler montmorillonite, 30 g of auxiliary zinc oxide, 30 g of stearic acid, and 25 g of zinc stearate were added to an open mill, and the roll shaft was controlled at 90°C. After mixing, 40 g of a crosslinking agent, dicumyl peroxide, was added and mixing was continued. Then, 136 g of a foaming agent, azodicarbonamide, was added, and after mixing, the product was sheeted. Finally, the product was subjected to mold foaming in a curing press at a temperature of 185°C, a pressure of 20 MPa, and a time of 6 min, discharged, and cooled to obtain a wear-resistant and slip-resistant EVA sole material.

[0050] Example 4:

[0051] (1) 5 kg of ethylene-vinyl acetate copolymer, 120 g of nylon fiber, 30 g of VA-SSS-based polyamide copolymer (prepared according to the process of Example 2), 250 g of filler montmorillonite, 60 g of auxiliary zinc oxide, 33 g of stearic acid, and 25 g of zinc stearate were added to an open mill, and the roll shaft was controlled at 90°C. After mixing, 25 g of a crosslinking agent, dicumyl peroxide, was added and mixing was continued. Then, 150 g of a foaming agent, azodicarbonamide, was added, and after mixing, the product was sheeted. Finally, the product was subjected to mold foaming in a curing press at a temperature of 175°C, a pressure of 20 MPa, and a time of 8 min, discharged, and cooled to obtain a wear-resistant and slip-resistant EVA sole material.

[0052] Example 5:

[0053] (1) Put 5 kg of ethylene-vinyl acetate copolymer, 120 g of nylon fiber, 50 g of VA-SSS-based polyamide copolymer (prepared according to the process of Example 2), 250 g of filler montmorillonite, 60 g of auxiliary zinc oxide, 33 g of stearic acid, and 25 g of zinc stearate into an open mill, control the roller shaft at 90°C, mix after adding 25 g of crosslinking agent dicumyl peroxide, and continue mixing; then add 150 g of foaming agent azodicarbonamide, mix after sheeting; finally, perform mold foaming in a vulcanizing machine at a temperature of 175°C, a pressure of 20 MPa, and a time of 8 min, discharge, cool, and obtain a wear-resistant and slip-resistant EVA shoe sole material.

[0054] The wear-resistant performance of the EVA shoe sole material is tested according to the method specified in the national standard GB / T 9867-2008, and the lower the wear volume, the better the wear-resistant performance. The slip-resistant performance is tested according to the method specified in GB / T 3903.6-2017, and the greater the friction coefficient, the better the slip-resistant performance. The tear strength is tested according to the national standard GB / T 10808-2006.

[0055] Table 1 Performance test of EVA shoe sole material

[0056]

[0057]

[0058] As can be seen from the above table, compared with Comparative Example 5, the VA-SSS-based polyamide copolymer is added in Example 1, the copolymer contains the same polyvinyl acetate block molecular chain as EVA, and also contains amide bond structural units, which have similar polarity with the polyamide molecular chain of nylon fiber, so that the VA-SSS-based polyamide copolymer plays the role of a compatibilizer, improves the compatibility of nylon fiber in EVA, and makes the nylon fiber play a better reinforcing role, which is conducive to improving the wear-resistant, slip-resistant, and mechanical strength of the EVA shoe sole material. In addition, the side chain of the VA-SSS-based polyamide copolymer contains a sodium sulfonate group, which can form an interaction with the surface of montmorillonite, play the role of a dispersant, and at the same time improve the interfacial force between montmorillonite and EVA and the dispersibility of montmorillonite. The uniformly dispersed montmorillonite has a good reinforcing effect, further improves the wear-resistant, slip-resistant, and mechanical strength of the material, exhibits a higher dry friction coefficient and tear strength, and at the same time reduces the wear volume of the material.

[0059] In Comparative Example 1, only montmorillonite is added, the compatibility between montmorillonite and EVA is poor, the dispersibility is not good, and the reinforcing effect is low, resulting in a large wear volume of the EVA shoe sole material, a low dry friction coefficient, poor wear-resistant and slip-resistant performance, and a low tear strength.

[0060] Compared with Comparative Example 1, Comparative Example 2 added VA-SSS based polyamide copolymer, which side chain contains sodium sulfonate groups, can form interaction with the surface of montmorillonite, play the role of dispersant, at the same time improve the interfacial force between montmorillonite and EVA, and improve the dispersibility of montmorillonite, and the uniformly dispersed montmorillonite has good reinforcing effect, which can improve the wear resistance, slip resistance and tear strength of the sole material.

[0061] Comparative Example 3 only added nylon fiber, which has poor compatibility with EVA, and the reinforcing effect is not good, resulting in poor wear resistance, slip resistance and tear strength of the sole material.

[0062] Compared with Comparative Example 3, Comparative Example 4 added VA-SSS based polyamide copolymer, which can play the role of compatibilizer, improve the compatibility of nylon fiber in EVA, make the nylon fiber have better reinforcing effect, and be conducive to improving the wear resistance, mechanical strength and other properties of EVA sole material,

[0063] Comparative Example 6 did not add 4-sodium styrene sulfonate instead of styrene, and the obtained carboxyl-terminated (vinyl acetate-styrene) copolymer and VA-St based polyamide copolymer side chain do not contain sodium sulfonate groups, which cannot form interaction with the surface of montmorillonite, cannot play the role of dispersant, and cannot improve the interfacial force between montmorillonite and EVA, and the reinforcing effect of montmorillonite is not good, and the wear resistance, slip resistance and tear strength of the sole material are poor.

[0064] Comparative Example 7 used 4-sodium styrene sulfonate instead of vinyl acetate, and the obtained carboxyl-terminated sodium styrene sulfonate copolymer and SSS based polyamide copolymer main chain do not contain polyvinyl acetate block molecular chains, which cannot play the role of compatibilizer, cannot improve the compatibility between nylon fiber, montmorillonite and EVA, resulting in poor wear resistance, slip resistance and tear strength of the sole material.

Claims

1. A wear resistant, slip resistant EVA shoe sole material characterized in that, The wear-resistant and skid-resistant EVA shoe sole material comprises 100 parts of ethylene-vinyl acetate copolymer, 1-4 parts of nylon fiber, 0.2-1 part of VA-SSS-based polyamide copolymer, 2-8 parts of filler, 0.6-1.2 parts of auxiliary agent, 0.5-0.8 parts of crosslinking agent, 2.2-3 parts of foaming agent, 0.6-0.8 parts of stearic acid, and 0.4-0.7 parts of zinc stearate. The preparation process of the VA-SSS-based polyamide copolymer comprises the following steps: adding N-methylpyrrolidone and carboxyl-terminated (vinyl acetate-styrene sodium sulfonate) copolymer into a reaction container, stirring, then adding diamine compound, pyridine, triphenyl phosphite, and calcium chloride, stirring and reacting in a nitrogen atmosphere, adding ethanol into the solution for dilution, filtering, washing with ethanol and water, and drying to obtain the VA-SSS-based polyamide copolymer. The filler is montmorillonite.

2. The abrasion resistant, slip resistant EVA shoe sole material of claim 1, wherein, The reaction temperature is 110-130℃, and the reaction time is 18-24h.

3. The abrasion resistant, slip resistant EVA shoe sole material of claim 1, wherein, The carboxyl-terminated (vinyl acetate-styrene sodium sulfonate) copolymer is used in an amount of 100 parts by weight, the diamine compound is 6.4-8.5 parts, the pyridine is 31-35 parts, the triphenyl phosphite is 26-32 parts, and the calcium chloride is 15-18 parts.

4. The abrasion resistant, slip resistant EVA shoe sole material of claim 3, wherein, The diamine compound is 1,4-butanediamine, 1,5-pentanediamine, or 1,6-hexanediamine.

5. The abrasion resistant, slip resistant EVA shoe sole material of claim 3, wherein, The preparation process of the carboxyl-terminated (vinyl acetate-styrene sodium sulfonate) copolymer comprises the following steps: adding toluene, vinyl acetate, 4-styrene sodium sulfonate, S,S'-bis(α,α'-methyl-α"-acetic acid) trithiocarbonate, and azobisisobutyronitrile into a reaction container, heating to 60-75℃ in a nitrogen atmosphere, reacting for 12-18h, adding ethanol into the solution for dilution, filtering, washing with ethanol, and drying to obtain the carboxyl-terminated (vinyl acetate-styrene sodium sulfonate) copolymer.

6. The abrasion resistant, slip resistant EVA shoe sole material of claim 5, wherein, The vinyl acetate is used in an amount of 100 parts by weight, the 4-styrene sodium sulfonate is 10-25 parts, the S,S'-bis(α,α'-methyl-α"-acetic acid) trithiocarbonate is 1.6-1.8 parts, and the azobisisobutyronitrile is 0.14-0.2 parts.

7. The abrasion resistant, slip resistant EVA shoe sole material of claim 1, wherein, The auxiliary agent is zinc oxide.

8. The abrasion resistant, slip resistant EVA shoe sole material of claim 1, wherein, The crosslinking agent is dicumyl peroxide, and the foaming agent is azodicarbonamide.

9. A process for the preparation of a wear resistant non-slip EVA shoe sole material as claimed in any one of claims 1 to 8, characterized in that, The preparation process comprises the following steps: adding ethylene-vinyl acetate copolymer, nylon fiber, VA-SSS-based polyamide copolymer, filler, auxiliary agent, stearic acid, and zinc stearate into an open mill, controlling the roller shaft at 90-100℃, mixing, then adding crosslinking agent and continuing mixing; then adding foaming agent and mixing to obtain a sheet; finally, performing mold foaming in a vulcanizing machine at a temperature of 175-185℃, a pressure of 15-20MPa, and a time of 6-8min, discharging, cooling, and obtaining the wear-resistant and skid-resistant EVA shoe sole material.

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