A puncture resistant shoe sole material and a method of making the same

Abstract

The present application relates to a kind of puncture-resistant shoe sole material and its preparation method, belong to EVA foamed material technical field, it includes according to weight parts: EVA master batch 100 parts, POE master batch 10-15 parts, modified EVA 25-35 parts, filling agent 10-13 parts, foaming agent 5.2-6.5 parts, bridging agent 0.9-1.2 parts, accelerator 1.4-1.8 parts and lubricant 2.5-3 parts;The modified EVA is mainly with EVA macromolecular chain, and has good compatibility with substrate EVA, rigid cage type POSS structure is introduced into substrate EVA in blending process, strengthens EVA substrate, while with EVA matrix composite forms countless microstructure of soft and hard uneven structure, increases the resistance of material and penetrator, and improves the puncture resistance, in test, puncture force reaches 900N or more, far higher than the standard of anti-stab product 490N.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of EVA foaming materials, and particularly relates to a puncture-resistant shoe sole material and a preparation method thereof. BACKGROUND

[0002] Ethylene-vinyl acetate copolymer (EVA) is one of the core research and development of shoe materials, and EVA foaming material is still the first choice for most leisure shoes and jogging shoes on the current market. Compared with rubber soles, EVA foaming material has the advantages of low density, good impact resistance, shock resistance and elasticity, and is light and comfortable to wear, which is widely loved by people.

[0003] However, the puncture resistance of EVA material is insufficient, and in some specific environments such as wild jungle and construction site, the sharp objects such as bamboo stick and steel nail cannot effectively penetrate the shoe sole, which limits the application of EVA material to the extreme. In the prior art, the puncture resistance of EVA can be improved to a certain extent by adding hard fillers to EVA material. However, these fillers form internal defects in EVA material, which increases the density of EVA material, especially in foaming material. When the material is deformed under stress, the fillers pierce the cell wall, which shortens the service life of the material. The introduction of cross-linking material into EVA material can also improve the puncture resistance to a certain extent by promoting the cross-linking degree of EVA, but it will reduce the resilience of EVA and affect the wearing comfort. Therefore, based on the existing EVA foaming system, the application discloses a puncture-resistant EVA foaming material for shoes. SUMMARY

[0004] In order to solve the technical problems mentioned in the background, the purpose of the application is to provide a puncture-resistant shoe sole material and a preparation method thereof.

[0005] The purpose of the application can be achieved by the following technical solutions:

[0006] A puncture-resistant shoe sole material comprises the following raw materials in parts by weight:

[0007] 100 parts of EVA master batch, 10-15 parts of POE master batch, 25-35 parts of modified EVA, 10-13 parts of filler, 5.2-6.5 parts of foaming agent, 0.9-1.2 parts of bridging agent, 1.4-1.8 parts of accelerator and 2.5-3 parts of lubricant.

[0008] The modified EVA is prepared by the following method:

[0009] Step A1: mix 3-mercapto propionic acid methyl ester, diethanolamine and anhydrous tetrahydrofuran, protect by nitrogen, heat to 55-65℃, apply 120-150rpm stirring and reflux, slowly add sodium hydride, control the addition of sodium hydride, the total reaction time is 2.5-3h, after the reaction, remove tetrahydrofuran by rotary evaporation to obtain an intermediate;

[0010] In the above reaction, the ratio of 3-mercapto propionic acid methyl ester, diethanolamine, sodium hydride and anhydrous tetrahydrofuran is 0.1mol:0.1mol:30-40mg:25-40mL, under the catalysis of sodium hydride, 3-mercapto propionic acid methyl ester and diethanolamine undergo amine-ester exchange.

[0011] Step A2: mix octavinyl-POSS and dimethylacetamide, then add the intermediate and dimethylphenylphosphine, protect by nitrogen, heat to 80-90℃, apply 60-90rpm stirring, assist with 150-200W / m 2 UV irradiation, react for 4.5-5.5h, after the reaction, wash with water, remove the aqueous phase and vacuum dry to obtain a modifier;

[0012] In the above reaction, the ratio of octavinyl-POSS, intermediate, dimethylphenylphosphine and dimethylacetamide is 10mmol:0.1mol:10-20mg:50-60mL, under the catalysis of dimethylphenylphosphine and UV irradiation initiation, the thiol group in the intermediate and the double bond of octavinyl-POSS undergo click addition.

[0013] Step A3: mix EVA-g-MAH, modifier, anhydrous sodium acetate and dimethylbenzene, protect by nitrogen, heat to 100-120℃, apply 30-55rpm stirring, react for 1.5-2.2h, after the reaction, remove dimethylbenzene by vacuum evaporation to obtain modified EVA;

[0014] In the above reaction, the ratio of EVA-g-MAH, modifier, anhydrous sodium acetate and dimethylbenzene is 100g:8-12mmol:0.8-1.1g:200-280mL, under the catalysis of anhydrous sodium acetate, the polyol hydroxyl group in the modifier molecule and the anhydride in the side chain of EVA-g-MAH undergo esterification, and the modifier is introduced into the molecular chain of EVA-g-MAH.

[0015] A preparation method of a puncture-resistant shoe sole material, comprising the following steps:

[0016] Step S1: mix the raw materials for making the shoe sole material in the proportion of parts by weight in a stirrer to obtain a mixture;

[0017] Step S2: the batch is transferred into a foaming machine, and is milled at 120-130 DEG C for 15-20 min, is extruded into a mold, and is foamed at 165-180 DEG C for 11-15 min, and is cooled and demolded to obtain the puncture-resistant shoe sole material.

[0018] Preferably, the filler is selected from calcium carbonate powder with fineness not less than 325 mesh.

[0019] Preferably, the foaming agent is compounded from foaming agent AC-3000 and foaming agent AK-3.

[0020] Preferably, the bridging agent is compounded from triallyl isocyanurate and bis-tert-butyl peroxyisopropyl benzene.

[0021] Preferably, the accelerator is selected from zinc oxide.

[0022] Preferably, the lubricant is selected from stearic acid.

[0023] Advantages of the present application:

[0024] The application discloses a foaming EVA shoe sole material, which greatly improves the puncture resistance of shoe materials by compounding self-made modified EVA, and has moderate apparent density, good resilience and folding resistance; the modified EVA is prepared by amine-ester exchange of 3-mercapto methyl propionate and diethanolamine to form an amide compound with terminal mercapto and hydroxyl, i.e. an intermediate, then the active mercapto of the intermediate is clicked to add to double bonds of octa-vinyl-POSS to graft the intermediate to the molecular end of octa-vinyl-POSS, i.e. a modifier, finally, under the catalysis of anhydrous sodium acetate, the polyol hydroxyl in the modifier molecule is esterified with anhydride between the side chains of EVA-g-MAH to introduce the modifier into the molecular chain of EVA-g-MAH; the modified EVA takes EVA macromolecular chains as the main body, has good compatibility with the base material EVA, introduces rigid cage-shaped POSS structure into the base material EVA in the blending process, on the one hand, strengthens the EVA base material and improves the puncture resistance of the material, on the other hand, the rigid cage-shaped POSS structure is dispersed in the EVA soft chain to form numerous micro non-uniform structures, when subjected to external puncture, the soft chain is easy to be deformed by puncture, while the rigid cage-shaped POSS structure is not easy to be deformed to form an anchor point, and numerous micro local stretching is formed at the puncture position, so that the modified EVA material is fully attached to the surface of the puncturing object to increase the penetration resistance, meanwhile, the non-uniform rigid cage-shaped POSS structure changes the stress uniformity of the material to form stress anisotropy at the penetration position to hinder the directional penetration of the puncturing object; the sulfur-nitrogen structure introduced by the intermediate in the preparation process of the modified EVA forms chelation, and chelates with the filler calcium carbonate and the accelerator zinc oxide in the blending and foaming process to improve the strengthening effect of these inorganic particles on the EVA base material, and meanwhile, is compounded with the rigid cage-shaped POSS structure in situ to strengthen the anchoring effect of the rigid chain segment. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0026] Embodiment 1, preparation of puncture-resistant shoe sole material, the specific implementation process is as follows:

[0027] (1) Preparation of modified EVA

[0028] Step A1: 3-mercapto propionic acid methyl ester, diethanolamine and anhydrous tetrahydrofuran were mixed, nitrogen was introduced for protection, the temperature was raised to 55°C, stirring was applied at 120 rpm and reflux was performed, sodium hydride was slowly added, the addition time was 1.5 h, after the complete addition of sodium hydride, constant temperature reflux reaction was continued, the total reaction time of the addition of sodium hydride was controlled to be 3 h, wherein the amount ratio of 3-mercapto propionic acid methyl ester, diethanolamine, sodium hydride and anhydrous tetrahydrofuran was 0.1 mol:0.1 mol:30 mg:25 mL, after the reaction was completed, tetrahydrofuran was removed by rotary evaporation to obtain an intermediate.

[0029] Step A2: octavinyl-POSS and dimethylacetamide were mixed, then the intermediate and dimethylphenyl phosphine were added and mixed, nitrogen was introduced for protection, the temperature was raised to 80°C, stirring was applied at 60 rpm, and 150 W / m 2 ultraviolet irradiation was applied, the reaction was performed for 5.5 h, wherein the amount ratio of octavinyl-POSS, the intermediate, dimethylphenyl phosphine and dimethylacetamide was 10 mmol:0.1 mol:10 mg:50 mL, after the reaction was completed, water was mixed and washed, the aqueous phase was removed and vacuum dried to obtain a modifier.

[0030] Step A3: EVA-g-MAH, the modifier, anhydrous sodium acetate and xylene were mixed, nitrogen was introduced for protection, the temperature was raised to 100°C, stirring was applied at 30 rpm, and the reaction was performed for 2.2 h, wherein the Bynel E418 type raw material of Dow Chemical was used in the implementation process of EVA-g-MAH, the amount ratio of EVA-g-MAH, the modifier, anhydrous sodium acetate and xylene was 100 g:8 mmol:0.8 g:200 mL, after the reaction was completed, xylene was removed by evaporation under reduced pressure to obtain modified EVA.

[0031] (2) Preparation of puncture-resistant shoe sole material

[0032] Step S1: Measure the raw materials according to the weight ratio: 100 parts EVA masterbatch (SF45 type from Taiwan Plastics Industries Co., Ltd.); 15 parts POE masterbatch (8003 type from Dow Chemical); 25 parts modified EVA (self-made in this embodiment); 13 parts filler (industrial grade 325 mesh calcium carbonate); and 5.2 parts foaming agent (AC-3000 type from Zhejiang Haitai New Material Technology Co., Ltd. and AK type from Hangzhou Lingbei Technology Co., Ltd.). -3 type foaming agent, the two are premixed and compounded at a weight ratio of 2:1; 0.9 parts of crosslinking agent, in the implementation process, industrial grade triallyl isocyanurate and di-tert-butylperoxyisopropylbenzene are compounded at a weight ratio of 10:1 and mixed during the batching process; 1.6 parts of accelerator, in the implementation process, rubber grade zinc oxide from Shanghai Changjiu Chemical Co., Ltd. is used; 3 parts of lubricant, in the implementation process, 1801 type stearic acid from Shanghai Changjiu Chemical Co., Ltd. is used; add all raw materials to the mixer and mix at 600 rpm for 15 minutes to obtain the compound.

[0033] Step S2: Transfer the compound material into a foaming machine, mix it at 120°C for 20 minutes, extrude it into a mold, foam it at 165°C for 15 minutes, cool and demold to obtain the puncture-resistant shoe sole material.

[0034] Example 2: Preparation of puncture-resistant shoe sole material, the specific implementation process is as follows:

[0035] (1) Preparation of modified EVA

[0036] Step A1: Mix methyl 3-mercaptopropionate, diethanolamine, and anhydrous tetrahydrofuran, purge with nitrogen for protection, heat to 65°C, stir at 150 rpm and reflux. Slowly add sodium hydride over 1 hour. After complete addition of sodium hydride, continue the reaction under constant temperature reflux for a total reaction time of 2.5 hours. The ratio of methyl 3-mercaptopropionate, diethanolamine, sodium hydride, and anhydrous tetrahydrofuran is 0.1 mol: 0.1 mol: 40 mg: 40 mL. After the reaction is complete, remove the tetrahydrofuran by rotary evaporation to obtain the intermediate.

[0037] Step A2: Mix octavinyl-POSS and dimethylacetamide, then add the intermediate and dimethylphenylphosphine, purge with nitrogen, heat to 90°C, stir at 90 rpm, and apply 200 W / m 2 The mixture was subjected to ultraviolet irradiation for 4.5 h. The ratio of octavinyl-POSS, intermediate, dimethylphenylphosphine, and dimethylacetamide was 10 mmol: 0.1 mol: 20 mg: 60 mL. After the reaction was completed, water was added to wash the mixture, the aqueous phase was removed, and the mixture was vacuum dried to obtain the modifier.

[0038] Step A3: Take EVA-g-MAH, modifier, anhydrous sodium acetate and xylene, protect with nitrogen, heat to 120°C, apply 55 rpm stirring, react for 1.5 h, wherein, Bynel E418 of Dow Chemical is used in the process of EVA-g-MAH, the amount ratio of EVA-g-MAH, modifier, anhydrous sodium acetate and xylene is 100 g: 12 mmol: 1.1 g: 280 mL, remove xylene by evaporation under reduced pressure after the reaction is completed, and modified EVA is obtained.

[0039] (2) Preparation of puncture-resistant shoe sole material

[0040] Step S1: Take raw materials according to weight ratio, 100 parts of EVA master batch, SF45 of Taiwan Plastic Industry Co., Ltd. is used in the process; 10 parts of POE master batch, 8003 of Dow Chemical is used in the process; 35 parts of modified EVA, which is self-made in this embodiment; 10 parts of filler, industrial-grade calcium carbonate of 325 mesh is used in the process; 6.5 parts of foaming agent, AC-3000 of Zhejiang Haiti New Material Technology Co., Ltd. and AK-3 of Hangzhou Linggebe Technology Co., Ltd. are premixed and compounded according to a weight ratio of 2:1; 1.1 parts of bridging agent, which is compounded according to a weight ratio of 10:1 between industrial-grade triallyl isocyanurate and bis-tert-butyl peroxyisopropylbenzene, and mixed during batching; 1.8 parts of accelerator, which is rubber-grade zinc oxide of Shanghai Changjiu Chemical Co., Ltd.; 2.5 parts of lubricant, which is 1801 type stearic acid of Shanghai Changjiu Chemical Co., Ltd.; Put each raw material into the stirrer, mix for 15 min at 600 rpm, and get the compound.

[0041] Step S2: Transfer the compound into the foaming machine, densify for 15 min at 130°C, extrude into the mold, foam for 11 min at 180°C, cool and demold, and get the puncture-resistant shoe sole material.

[0042] Example 3, preparation of puncture-resistant shoe sole material, the specific implementation process is as follows:

[0043] (1) Preparation of modified EVA

[0044] Step A1: Take 3-mercapto propionic acid methyl ester, diethanolamine and anhydrous tetrahydrofuran, protect with nitrogen, heat to 60°C, apply 120 rpm stirring and reflux, slowly add sodium hydride, the addition time is 1.3 h, continue to heat and reflux after the complete addition of sodium hydride, control the total reaction time of sodium hydride addition, the amount ratio of 3-mercapto propionic acid methyl ester, diethanolamine, sodium hydride and anhydrous tetrahydrofuran is 0.1 mol: 0.1 mol: 35 mg: 40 mL, remove tetrahydrofuran by rotary evaporation after the reaction is completed, and get the intermediate.

[0045] Step A2: Take octavinyl-POSS and dimethylacetamide, mix them, then add the intermediate and dimethylphenylphosphine, protect them with nitrogen, warm them to 85°C, apply 90 rpm stirring, and assist with 180 W / m 2 UV irradiation for 5.2 h, wherein the amounts of octavinyl-POSS, intermediate, dimethylphenylphosphine, and dimethylacetamide are 10 mmol: 0.1 mol: 15 mg: 60 mL, after the reaction is completed, wash with water, remove the aqueous phase, and vacuum dry to obtain the modifier.

[0046] Step A3: Take EVA-g-MAH, modifier, anhydrous sodium acetate, and xylene, protect them with nitrogen, warm them to 110°C, apply 55 rpm stirring, and react for 2 h, wherein the Bynel E418 type raw material of Dow Chemical is used in the implementation of EVA-g-MAH, and the amounts of EVA-g-MAH, modifier, anhydrous sodium acetate, and xylene are 100 g: 10 mmol: 1.1 g: 240 mL, after the reaction is completed, remove xylene by evaporation under reduced pressure to obtain modified EVA.

[0047] (2) Preparation of a puncture-resistant shoe sole material

[0048] Step S1: Take the raw materials according to the weight ratio, 100 parts of EVA masterbatch, the SF45 type raw material of Taiwan Plastic Industry Co., Ltd. is used in the implementation process; 12 parts of POE masterbatch, the 8003 type raw material of Dow Chemical is used in the implementation process; 30 parts of modified EVA, which is self-made in this embodiment; 11 parts of filler, industrial-grade 325 mesh calcium carbonate is used in the implementation process; 5.8 parts of foaming agent, the AC-3000 type foaming agent of Zhejiang Haiti New Material Technology Co., Ltd. and the AK-3 type foaming agent of Hangzhou Lingge Technology Co., Ltd. are premixed and compounded according to a weight ratio of 2:1; 1.2 parts of bridging agent, industrial-grade triallyl isocyanurate and bis-tert-butyl peroxyisopropylbenzene are compounded according to a weight ratio of 10:1, and mixed during batching; 1.4 parts of accelerator, rubber-grade zinc oxide of Shanghai Changjiu Chemical Co., Ltd. is used in the implementation process; 2.7 parts of lubricant, 1801 type stearic acid of Shanghai Changjiu Chemical Co., Ltd. is used in the implementation process; add each raw material to a stirrer, mix at 600 rpm for 15 min, and obtain a compound.

[0049] Step S2: Transfer the compound into a foaming machine, densify at 130°C for 17 min, extrude into a mold, foam at 170°C for 13 min, cool and demold, and obtain a puncture-resistant shoe sole material.

[0050] Comparative Example 1

[0051] The comparative example is a control example of Example 3, in which 30 parts of modified EVA in the raw material is replaced by 26 parts of Bynel E418 type EVA-g-MAH and 4 parts of octavinyl-POSS, and the rest of the implementation process is exactly the same.

[0052] Comparative Example 2

[0053] The comparative example refers to the prior art, and no modified EVA is added. The sole material is prepared by increasing the amount of filler and bridging agent. The specific ingredients are: EVA master batch 100 parts, POE master batch 12 parts, filler 22 parts, foaming agent 5.2 parts, bridging agent 3.5 parts, accelerator 1.4 parts and lubricant 2.7 parts. The specific process for preparing the sole material is the same as that of Example 3.

[0054] Comparative Example 3

[0055] The comparative example is the EVA sole material of TM3161 type sports safety shoes of Ruian Hongshun Shoes Co., Ltd.

[0056] Samples are taken from the above sole materials, and the density test is carried out in accordance with the HG / T 2872-2009 standard; the puncture test is carried out in accordance with the GB / T12017-1989 standard; the resilience test is carried out in accordance with the HG / T 4993-2016 standard; and the folding resistance test is carried out in accordance with the GB / T3903.1-2017. The specific test results are shown in the following table:

[0057]

[0058]

[0059] From the test results in the above table, it can be seen that the sole material of the example has moderate apparent density, good resilience and folding resistance, and the puncture force reaches more than 900N, which shows excellent puncture resistance compared with the comparative examples.

[0060] In the description of the specification, the description of the reference terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are contained in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0061] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements or use similar ways to replace the described specific embodiments, as long as they do not deviate from the scope of the invention or exceed the scope defined by the present claims.

Claims

1. A puncture-resistant shoe sole material, characterized in that, The raw materials include the following by weight: 100 parts EVA masterbatch, 10-15 parts POE masterbatch, 25-35 parts modified EVA, 10-13 parts filler, 5.2-6.5 parts foaming agent, 0.9-1.2 parts crosslinking agent, 1.4-1.8 parts accelerator, and 2.5-3 parts lubricant; The modified EVA was prepared by the following method: Step A1: Mix methyl 3-mercaptopropionate, diethanolamine and anhydrous tetrahydrofuran, purge with nitrogen for protection, heat to 55-65℃ and stir under reflux, slowly add sodium hydride, control the total reaction time for sodium hydride addition to be 2.5-3h, remove tetrahydrofuran by rotary evaporation after the reaction is complete to obtain the intermediate; Step A2: Mix octavinyl-POSS and dimethylacetamide, then add the intermediate and dimethylphenylphosphine, purge with nitrogen for protection, heat to 80-90℃, stir, and supplement with 150-200W / m 2 The mixture was irradiated with ultraviolet light for 4.5-5.5 hours. After the reaction was completed, water was added to wash the mixture, the aqueous phase was removed, and the mixture was dried under vacuum to obtain the modifier. Step A3: Mix EVA-g-MAH, modifier, anhydrous sodium acetate and xylene, purge with nitrogen for protection, heat to 100-120℃, stir and react for 1.5-2.2h, remove xylene by vacuum distillation after the reaction is complete to obtain modified EVA; The filler is calcium carbonate micro powder with a fineness of not less than 325 mesh; The accelerator is zinc oxide.

2. The puncture-resistant sole material according to claim 1, characterized in that, The ratio of methyl 3-mercaptopropionate, diethanolamine, sodium hydride, and anhydrous tetrahydrofuran is 0.1 mol: 0.1 mol: 30-40 mg: 25-40 mL.

3. The puncture-resistant sole material according to claim 2, characterized in that, The ratio of octavinyl-POSS, intermediate, dimethylphenylphosphine, and dimethylacetamide is 10 mmol: 0.1 mol: 10-20 mg: 50-60 mL.

4. The puncture-resistant sole material according to claim 3, characterized in that, The ratio of EVA-g-MAH, modifier, anhydrous sodium acetate and xylene is 100g: 8-12mmol: 0.8-1.1g: 200-280mL.

5. The method for preparing a puncture-resistant shoe sole material according to claim 4, characterized in that, Includes the following steps: Step S1: Add each raw material to the mixer according to the weight ratio and mix well to obtain the batch material; Step S2: Transfer the compound material into a foaming machine, mix it at 120-130℃ for 15-20 minutes, extrude it into a mold, foam it at 165-180℃ for 11-15 minutes, cool and demold to obtain the puncture-resistant shoe sole material.

6. The method for preparing a puncture-resistant shoe sole material according to claim 5, characterized in that, The foaming agent is a compound of foaming agent AC-3000 and foaming agent AK-3.

7. The method for preparing a puncture-resistant shoe sole material according to claim 5, characterized in that, The crosslinking agent is a compound of triallyl isocyanurate and bis-tert-butylperoxyisopropylbenzene.

8. The method for preparing a puncture-resistant shoe sole material according to claim 5, characterized in that, The lubricant is stearic acid.

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