A wear-resistant sole material and preparation method thereof

Abstract

The invention discloses a wear-resistant sole material and a preparation method thereof, and belongs to the technical field of polymer materials. Raw materials: 40-50 parts of natural rubber, 20-30 parts of styrene-butadiene rubber, 20-30 parts of chloroprene rubber, 3-8 parts of modified nano calcium carbonate, 1-2 parts of zinc oxide, 0.1-0.6 parts of stearic acid, 0.5-2 parts of antioxidant, 0.3-2 parts of auxiliary agent, 0.1-1 parts of 2-mercaptobenzothiazole, 0.2-2 parts of 2-acrylamide-2-methylpropanesulfonic acid and 0.05-0.1 parts of initiator. The modified nano calcium carbonate can be combined with rubber macromolecules to form a three-dimensional network structure, which not only improves the wear resistance, impact strength and tensile strength of the material, but also improves the heat resistance of the material. The auxiliary agent enables the sole material to have excellent resistance to thermal oxygen aging and ultraviolet absorption, and the effect of other additives greatly improves the weather resistance of the sole material of the present invention.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a wear-resistant sole material and a preparation method thereof. Background Art

[0002] Shoes protect the human foot and can improve the effect of exercise to a certain extent. As the core part of sports shoes, the sole provides stability, cushioning and rebound effects, as well as absorbs the impact generated during exercise, which largely determines the performance of the shoe.

[0003] Rubber is the basic raw material of the rubber industry. As an elastomer, it can recover quickly and has good physical and mechanical properties and chemical stability. It is widely used in soles, hoses, cables and other fields. However, rubber has problems such as easy wear, easy aging and poor mechanical properties in application. Therefore, designing a wear-resistant sole material is an urgent problem to be solved. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a wear-resistant sole material and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A wear-resistant sole material comprises the following raw materials in parts by weight: 40-50 parts of natural rubber, 20-30 parts of styrene-butadiene rubber, 20-30 parts of chloroprene rubber, 3-8 parts of modified nano calcium carbonate, 1-2 parts of zinc oxide, 0.1-0.6 parts of stearic acid, 0.5-2 parts of antioxidant, 0.3-2 parts of auxiliary agent, 0.1-1 parts of 2-mercaptobenzothiazole, 0.2-2 parts of 2-acrylamide-2-methylpropanesulfonic acid and 0.05-0.1 parts of initiator.

[0007] Further, the modified nano calcium carbonate is prepared by the following steps:

[0008] The nano-calcium carbonate was immersed in an isopropyl tri(dioctyl pyrophosphate) titanate coupling agent diluted with acetone, and then the paste-like coupling agent and nano-calcium carbonate mixture was placed on an ultrasonic oscillator for 30 minutes, the temperature was set to 60°C, and then cis-dodec-11-enoic acid was slowly added to the mixture and stirred evenly, and then ultrasonically vibrated for 60 minutes, filtered, and the filter cake was rinsed with acetone. Finally, the filter cake was placed in a vacuum oven and dried at 100°C for 12 hours to obtain modified nano-calcium carbonate.

[0009] Furthermore, the mass ratio of cis-dodec-11-enoic acid, titanate coupling agent and nano-calcium carbonate is 0.4-0.5:0.3:1-1.2.

[0010] The surface of nano-calcium carbonate contains many hydrophilic and oleophobic hydroxyl groups. One end of cis-dodec-11-enoic acid is a hydrophilic carboxyl group, which can form chemical bonds with calcium ions on the surface of nano-calcium carbonate and undergo hydrogen bond adsorption with the surface hydroxyl groups, thereby forming an active coating layer to prevent the agglomeration of nano-calcium carbonate particles. The other end is a long-chain alkyl group, which is compatible with polymers. Nano-calcium carbonate modified with fatty acids can better improve the rheological properties of the material and is easy to process. The unsaturated double bond at the end of the fatty acid can also react chemically with additives or base resins.

[0011] Titanate coupling agent can form chemical bonds with the hydroxyl groups on the surface of nano-calcium carbonate. The nano-calcium carbonate modified with titanate coupling agent has good compatibility with polymer molecules, can reduce viscosity and improve the dispersibility of the material. In addition, the modification of titanate coupling agent containing halogen-free flame retardant element P improves the flame retardant properties of the material. Titanate coupling agent bridges between inorganic filler molecules such as nano-calcium carbonate and polymer molecules, enhances the interaction between the polymer matrix and the inorganic filler, thereby improving the flame retardancy and mechanical physical properties of the material such as tensile strength, impact strength, bending strength, wear resistance, etc.

[0012] Cis-11-dodecenoic acid and titanate coupling agent synergistically modify nano calcium carbonate, making the nano calcium carbonate particles ultrafine, narrow particle size distribution, and controllable crystal shape. After its surface is coated with organic matter, the single dispersed inorganic rigid particles form a chain structure, which then combines with rubber macromolecules to form a three-dimensional network structure, which not only improves the flame retardancy, wear resistance, tensile strength and impact strength of the material, but also improves the thermal insulation and heat resistance of the material to a certain extent.

[0013] Furthermore, the antioxidant is one or more of antioxidant AW, antioxidant BLE, antioxidant RD and antioxidant D.

[0014] Furthermore, the initiator is benzoyl peroxide.

[0015] Further, the auxiliary agent is prepared by the following steps:

[0016] S1. Add methanol, 50 wt% sodium hydroxide solution and pentaerythritol tetrakis-3-mercaptopropionate into a four-necked flask, stir thoroughly until mixed evenly, slowly add 4-chloro-1-butene and potassium iodide while stirring, raise the temperature in the oil bath to 75°C after the addition, reflux at this temperature for 2 h, then cool to room temperature, add deionized water, separate the liquids, take the organic phase, dry it with anhydrous magnesium sulfate, filter, and distill the filtrate under reduced pressure under nitrogen protection to obtain intermediate 1; the amount ratio of pentaerythritol tetrakis-3-mercaptopropionate, 4-chloro-1-butene and potassium iodide is 32 mL:10 mL:1 g.

[0017] Under the catalysis of potassium iodide, when the molar ratio of pentaerythritol tetra-3-mercaptopropionate and 4-chloro-1-butene is 1:1.1-1.2, the sulfur atom of pentaerythritol tetra-3-mercaptopropionate attacks the alkyl carbon cation of alkyl 4-chloro-1-butene to undergo a nucleophilic substitution reaction. The reaction process is as follows:

[0018]

[0019] S2. Add methanol, 50 wt% sodium hydroxide solution and intermediate 1 into a four-necked flask, stir thoroughly until mixed, slowly add 2,6-di-tert-butyl-4-bromomethylphenol and potassium iodide while stirring, heat the oil bath to 75°C after the addition, reflux at this temperature for 3 hours, then cool to room temperature, add water and separate the liquids, take the organic phase, dry it with anhydrous magnesium sulfate, filter, and distill under reduced pressure under nitrogen protection to obtain intermediate 2; the usage ratio of intermediate 1, 2,6-di-tert-butyl-4-bromomethylphenol and potassium iodide is 11.3 g:7.48 g:0.25 g.

[0020] Under the catalysis of potassium iodide, when the molar ratio of intermediate 1 and 2,6-di-tert-butyl-4-bromomethylphenol is 1:1.1-1.2, a nucleophilic substitution reaction will occur between the two. The reaction process is as follows:

[0021]

[0022] S3. Add a mixed solvent of benzene and methanol, 50wt% sodium hydroxide solution and intermediate 2 to a four-necked flask, stir thoroughly until the mixture is uniform, slowly add 2'-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole (UV-326) and potassium iodide while stirring, heat the oil bath to 75°C after the addition, reflux at this temperature for 3h, then cool to room temperature, add water and separate the liquids, take the organic phase, dry it with anhydrous magnesium sulfate, filter it, and distill it under reduced pressure under nitrogen protection to obtain the auxiliary agent. The dosage ratio of intermediate 2, UV-326 and potassium iodide is 15.9g:7.9g:0.25g.

[0023] Under the catalysis of potassium iodide, when the molar ratio of intermediate 2 and UV-326 is 1:1.1-1.2, intermediate 2 and UV-326 undergo a nucleophilic substitution reaction, and the reaction process is as follows:

[0024]

[0025] The auxiliary agent of the present invention contains a thioester antioxidant structure and a hindered phenol antioxidant structure, both of which are chain-terminating antioxidants and can capture free radicals. The two synergistically resist oxidation, and can make the material have excellent thermal-oxidative aging resistance; the auxiliary agent contains a benzotriazole ultraviolet absorption structure, which has stable performance, strong ultraviolet absorption capacity, and itself also has antioxidant properties. It has a synergistic effect when used with the antioxidant, and can improve the thermal-oxidative aging resistance of the material and enhance the ultraviolet absorption capacity of the material; the unsaturated carbon-carbon double bonds in the auxiliary agent can produce chemical reactions with the base resin, other additives such as modified nano calcium carbonate, and the combination of thiol, hydroxyl and ester groups, the auxiliary agent has stronger binding force and compatibility with the base resin and other additives, so that the material can have excellent antioxidant properties, wear resistance, impact resistance and flame retardancy for a long time.

[0026] A method for preparing a wear-resistant sole material comprises the following steps:

[0027] Firstly, natural rubber, styrene-butadiene rubber and chloroprene rubber are added to an open mixer in proportion and plasticized to obtain a rubber mixture; secondly, other additives are added in proportion, mixed evenly, and mixed and kneaded in an internal mixer to obtain a rubber mixture; then, the rubber is rolled in the open mixer and cut to obtain a rubber sheet; then, the rubber sheet is placed in a sole-shaped mold for shaping, and vulcanized in a vulcanizer; finally, the edges are trimmed, ground and painted to obtain a wear-resistant sole material.

[0028] The beneficial effects of the present invention are as follows: after the surface of the modified nano calcium carbonate is coated with organic substances, the single dispersed inorganic rigid particles form a chain structure, which then combines with the rubber macromolecules to form a three-dimensional network structure, which not only improves the wear resistance, tensile strength and impact strength of the sole material, but also improves the heat resistance of the material to a certain extent. The benzotriazole ultraviolet absorber in the auxiliary agent, the thioester antioxidant structure, and the hindered phenol antioxidant structure work synergistically, so that the sole material has excellent resistance to thermal oxidation aging and ultraviolet absorption. In addition, the effects of other additives greatly improve the weather resistance of the sole material of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] The specific steps for preparing modified nano calcium carbonate are as follows:

[0032] Add 6g of isopropyl tri(dioctyl pyrophosphate) titanate coupling agent and 100mL of acetone to a beaker, stir thoroughly until mixed, then add 24g of nano calcium carbonate, stir thoroughly until mixed, then place on an ultrasonic oscillator for 30min, set the temperature to 60°C, slowly add 8g of cis-dodec-11-enoic acid to the mixture and stir evenly, then ultrasonically oscillate for 60min, filter, rinse the filter cake with acetone, and finally place the filter cake in a vacuum oven and dry at 100°C for 12h to obtain modified nano calcium carbonate.

[0033] Example 2

[0034] The specific steps for preparing modified nano calcium carbonate are as follows:

[0035] The remaining steps remain unchanged, only the mass of cis-dodec-11-enoic acid is changed to 10 g, and the mass of nano-calcium carbonate is changed to 20 g, to obtain modified nano-calcium carbonate.

[0036] Example 3

[0037] The specific steps for preparing modified nano calcium carbonate are as follows:

[0038] The remaining steps remain unchanged, only the mass of cis-dodec-11-enoic acid is changed to 8.4 g, and the mass of nano-calcium carbonate is changed to 22 g, to obtain modified nano-calcium carbonate.

[0039] Example 4

[0040] Preparation of auxiliary agent, the specific steps are as follows:

[0041] S1. Add 100 mL of methanol, 12 g of 50 wt% sodium hydroxide solution and 32 mL of pentaerythritol tetrakis-3-mercaptopropionate into a 250 mL four-necked flask, stir thoroughly until the mixture is uniform, slowly add 10 mL of 4-chloro-1-butene, 6 mL of deionized water and 1 g of potassium iodide while stirring, heat the oil bath to 75 ° C after the addition, reflux at this temperature for 2 h, then cool to room temperature, add deionized water, separate the liquids, take the organic phase, dry it with anhydrous magnesium sulfate, filter it, and distill the filtrate under reduced pressure under nitrogen protection to obtain intermediate 1;

[0042] S2. Add 100 mL of methanol, 3 g of 50 wt% sodium hydroxide solution and 11.3 g of intermediate 1 into a 250 mL four-necked flask, stir thoroughly until mixed, slowly add 7.48 g of 2,6-di-tert-butyl-4-bromomethylphenol, 4 mL of deionized water and 0.25 g of potassium iodide while stirring, after the addition is completed, heat the oil bath to 75 ° C, reflux at this temperature for 3 h, then cool to room temperature, add water and separate the liquids, take the organic phase, dry it with anhydrous magnesium sulfate, filter it, and distill it under reduced pressure under nitrogen protection to obtain intermediate 2;

[0043] S3. Add 60 mL of a mixed solvent of benzene and 40 mL of methanol, 3 g of a 50 wt% sodium hydroxide solution and 15.9 g of intermediate 2 into a 250 mL four-necked flask, stir thoroughly until the mixture is uniform, slowly add 7.9 g of UV-326, 4 mL of deionized water and 0.25 g of potassium iodide while stirring, after the addition is completed, heat the oil bath to 75 ° C, reflux at this temperature for 3 h, then cool to room temperature, add water and separate the liquids, take the organic phase, dry it with anhydrous magnesium sulfate, filter, and distill under reduced pressure under nitrogen protection to obtain an auxiliary agent.

[0044] Example 5

[0045] The specific steps of preparing the wear-resistant sole material are as follows:

[0046] First, 45 parts of natural rubber, 25 parts of styrene-butadiene rubber and 25 parts of chloroprene rubber are added to an open mill for plasticizing to obtain a rubber mixture; secondly, 6 parts of the modified nano-calcium carbonate of Example 1, 1.8 parts of zinc oxide, 0.5 parts of stearic acid, 1 part of antioxidant AW, 2 parts of the auxiliary agent of Example 4, 0.8 parts of 2-mercaptobenzothiazole, 1.6 parts of 2-acrylamide-2-methylpropanesulfonic acid and 0.08 parts of benzoyl peroxide are added, mixed evenly, and mixed and kneaded in an internal mixer to obtain a rubber mixture; then, the open mill is used for sheeting and cutting to obtain a rubber sheet; then, the rubber sheet is placed in a sole-shaped mold for shaping and vulcanized in a vulcanizer; finally, the edges are trimmed, ground and painted to obtain a wear-resistant sole material.

[0047] Example 6

[0048] The specific steps of preparing the wear-resistant sole material are as follows:

[0049] First, 50 parts of natural rubber, 30 parts of styrene-butadiene rubber and 30 parts of chloroprene rubber are added to an open mill for plasticizing to obtain a rubber mixture; secondly, 8 parts of the modified nano-calcium carbonate of Example 2, 2 parts of zinc oxide, 0.6 parts of stearic acid, 2 parts of antioxidant BLE, 0.8 parts of the auxiliary agent of Example 4, 1 part of 2-mercaptobenzothiazole, 2 parts of 2-acrylamide-2-methylpropanesulfonic acid and 0.1 parts of benzoyl peroxide are added, mixed evenly, and mixed and kneaded in an internal mixer to obtain a rubber mixture; then, the mixture is kneaded in an open mill and cut to obtain a rubber sheet; then, the rubber sheet is placed in a sole-shaped mold for shaping and vulcanized in a vulcanizer; finally, the edges are trimmed, ground and painted to obtain a wear-resistant sole material.

[0050] Example 7

[0051] The specific steps of preparing the wear-resistant sole material are as follows:

[0052] First, 40 parts of natural rubber, 20 parts of styrene-butadiene rubber and 20 parts of chloroprene rubber are added to an open mill for plasticizing to obtain a rubber mixture; secondly, 3 parts of the modified nano-calcium carbonate of Example 3, 1 part of zinc oxide, 0.1 part of stearic acid, 0.5 part of antioxidant RD, 0.3 part of the auxiliary agent of Example 4, 0.1 part of 2-mercaptobenzothiazole, 0.2 part of 2-acrylamide-2-methylpropanesulfonic acid and 0.05 part of benzoyl peroxide are added, mixed evenly, and mixed and kneaded in an internal mixer to obtain a rubber mixture; then, the open mill is used for sheeting and cutting to obtain a rubber sheet; then, the rubber sheet is placed in a sole-shaped mold for shaping and vulcanized in a vulcanizer; finally, the edges are trimmed, ground and painted to obtain a wear-resistant sole material.

[0053] Comparative Example 1

[0054] The remaining steps remain unchanged, and the auxiliary agent in Example 5 is removed to prepare the sole material.

[0055] Comparative Example 2

[0056] The remaining steps remain unchanged, and the modified nano-calcium carbonate in Example 5 is removed to prepare the sole material.

[0057] Comparative Example 3

[0058] The remaining steps remain unchanged, and the auxiliary agent and modified nano-calcium carbonate in Example 5 are removed to prepare the sole material.

[0059] Comparative Example 4

[0060] The remaining steps remained unchanged, except that the auxiliary agent in Example 5 was replaced by antioxidant 1010, and the modified nano calcium carbonate was replaced by white carbon black to prepare the sole material.

[0061] Performance Testing

[0062] The sole materials prepared in Examples 5-7 and Comparative Examples 1-4 were subjected to the following performance tests, and the test results are shown in the table:

[0063]

[0064] As can be seen from the above table, the sole material prepared by the embodiment of the present invention has excellent tensile strength, tear strength, wear resistance and thermal oxidation aging resistance. As can be seen from the data of comparative example 1, although the auxiliary agent of the present invention cannot improve the mechanical properties of the material, there is an interaction between the double bonds of the auxiliary agent and the double bonds on the surface of the modified nano-calcium carbonate, and the auxiliary agent can further promote the dispersion of the modified nano-calcium carbonate. Therefore, when the auxiliary agent is not added, the mechanical properties of the sole material are reduced, and the wear resistance is also reduced; the data of comparative example 2 on heat aging resistance and ultraviolet aging resistance further confirm the existence of the interaction between the auxiliary agent and the modified nano-calcium carbonate; as can be seen from the data of comparative example 4, the mechanical properties and antioxidant properties of the sole material prepared by introducing the existing antioxidant and white carbon black by simple physical addition are far inferior to the sole material prepared by the embodiment of the present invention. The auxiliary agent of the present invention and the nano-calcium carbonate synergistically act, and other additives are combined with the matrix resin to form a three-dimensional network structure, which together give the sole material excellent wear resistance, thermal oxidation aging resistance and mechanical physical properties.

[0065] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation 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.

[0066] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A wear-resistant sole material, characterized in that: The invention comprises the following raw materials in parts by weight: 40-50 parts of natural rubber, 20-30 parts of styrene-butadiene rubber, 20-30 parts of chloroprene rubber, 3-8 parts of modified nano calcium carbonate, 1-2 parts of zinc oxide, 0.1-0.6 parts of stearic acid, 0.5-2 parts of antioxidant, 0.3-2 parts of auxiliary agent, 0.1-1 parts of 2-mercaptobenzothiazole, 0.2-2 parts of 2-acrylamide-2-methylpropanesulfonic acid and 0.05-0.1 parts of initiator; Wherein, the auxiliary agent is prepared by the following steps: S1. Add methanol, sodium hydroxide solution and pentaerythritol tetrakis-3-mercaptopropionate into a flask, stir, add 4-chloro-1-butene and potassium iodide, heat to 75°C and reflux for 2h, cool to room temperature, add deionized water, separate the liquids, take the organic phase, dry it, filter it, and distill it under reduced pressure to obtain intermediate 1; S2. Add methanol, sodium hydroxide solution and intermediate 1 into a flask, stir, add 2,6-di-tert-butyl-4-bromomethylphenol and potassium iodide, heat to 75°C and reflux for 3h, cool to room temperature, add deionized water, separate the liquids, take the organic phase, dry it, filter it, and distill it under reduced pressure to obtain intermediate 2; S3, add benzene and methanol, sodium hydroxide solution and intermediate 2 into a flask, stir, add UV-326 and potassium iodide, heat to 75 ° C and reflux for 3 hours, then cool to room temperature, add deionized water, separate the liquids, take the organic phase, dry it, filter it, and distill it under reduced pressure to obtain an auxiliary agent; Modified nano calcium carbonate is prepared by the following steps: Nano calcium carbonate, isopropyl tri(dioctyl pyrophosphate acyloxy) titanate coupling agent and acetone were mixed, ultrasonicated at 60°C for 30 minutes, and then cis-dodec-11-enoic acid was added, stirred, ultrasonicated for 60 minutes, filtered, and the filter cake was washed with acetone and dried to obtain modified nano calcium carbonate.

2. A wear-resistant sole material according to claim 1, characterized in that: The usage ratio of pentaerythritol tetrakis-3-mercaptopropionate, 4-chloro-1-butene and potassium iodide in step S1 is 32 mL:10 mL:1 g.

3. The wear-resistant sole material according to claim 1, characterized in that: The usage ratio of the intermediate 1, 2,6-di-tert-butyl-4-bromomethylphenol and potassium iodide in step S2 is 11.3 g:7.48 g:0.25 g.

4. The wear-resistant sole material according to claim 1, characterized in that: The usage ratio of intermediate 2, UV-326 and potassium iodide in step S3 is 15.9 g:7.9 g:0.25 g.

5. The wear-resistant sole material according to claim 1, characterized in that: The antioxidant is one or more of antioxidant AW, antioxidant BLE, antioxidant RD and antioxidant D.

6. The wear-resistant sole material according to claim 2, characterized in that: The mass ratio of cis-dodec-11-enoic acid, titanate coupling agent and nano calcium carbonate is 0.4-0.5:0.3:1-1.

2.

7. The method for preparing a wear-resistant sole material according to claim 1, characterized in that: The steps include: Firstly, natural rubber, styrene-butadiene rubber and chloroprene rubber are added to an open mixer in proportion and plasticized to obtain a rubber mixture; secondly, other additives are added in proportion, mixed evenly, and mixed and kneaded in an internal mixer to obtain a rubber mixture; then, the rubber is rolled in the open mixer and cut to obtain a rubber sheet; then, the rubber sheet is placed in a sole-shaped mold for shaping, and vulcanized in a vulcanizer; finally, the edges are trimmed, ground and painted to obtain a wear-resistant sole material.

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