Light polyurethane shoe material for sports shoes and preparation process of light polyurethane shoe material

Abstract

The invention relates to the technical field of polyurethane materials, in particular to a light polyurethane shoe material for sports shoes and a preparation process thereof, and the light polyurethane shoe material comprises the following components: 40-60 parts by weight of polyether polyol, 20-40 parts by weight of hexamethylene diisocyanate, 20-40 parts by weight of N, N-dimethylformamide, 1-5 parts by weight of a coupling agent, 1-5 parts by weight of an antioxidant, 1-5 parts The invention relates to a flame-retardant and flame-retardant material which is prepared from the following components in parts by weight: 0.5-1.5 parts of N, N-dimethyl cyclohexylamine, 5-15 parts of modified p-toluenesulfonhydrazide microcapsules, 1-3 parts of a nucleating agent, 0.5-2 parts of zinc dialkyl dithiophosphate, 0.5-2 parts of phenyl salicylate and 0.5-2 parts of polyoxyethylene sorbitan monooleate. The aryl halide can improve the thermal decomposition temperature of p-toluenesulfonyl hydrazide, so that the p-toluenesulfonyl hydrazide is not easy to decompose in advance under a high-temperature processing condition, and the foaming process can be accurately controlled. Due to the fact that the fatty acid can reduce the surface tension of the system, gas can form tiny bubble nucleuses in the system more easily, the number of bubble nucleation sites is increased, a more fine and uniform bubble structure can be generated, and the buffering performance and the overall quality of the shoe material are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurethane materials, and specifically, to a lightweight polyurethane shoe material for sports shoes and its preparation process. Background Art

[0002] With the continuous improvement of people's health awareness, the number of people participating in various sports is increasing. From daily jogging, aerobics to professional basketball, football, tennis and other competitive sports, the demand for sports shoes is becoming more diverse and demanding. Consumers not only expect sports shoes to provide excellent support and cushioning protection to reduce sports injuries, but also desire the shoes to be lightweight, so as to reduce the burden on the feet during exercise and improve the flexibility and durability of sports.

[0003] As a kind of polymer, polyurethane material itself has good mechanical properties, wear resistance and processability, and has already been applied in the field of shoe materials. However, conventional polyurethane shoe materials have not fully met the pursuit of extreme lightweight of modern sports shoes. Traditional polyurethane materials are usually heavy, which affects the overall weight of the shoes and is not conducive to improving the sports efficiency of the wearer. Some chemical blowing agents are prone to produce by-products at high temperatures, which affects the quality of the final product. In view of this, we propose a lightweight polyurethane shoe material for sports shoes and its preparation process. Summary of the Invention

[0004] The purpose of the present invention is to provide a lightweight polyurethane shoe material for sports shoes and its preparation process to solve the problems raised in the above background art that traditional polyurethane materials are usually heavy, which affects the overall weight of the shoes and is not conducive to improving the sports efficiency of the wearer, and some chemical blowing agents are prone to produce by-products at high temperatures, which affects the quality of the final product.

[0005] To achieve the above purpose, the present invention provides a lightweight polyurethane shoe material for sports shoes, including the following components: 40 - 60 parts by weight of polyether polyol, 20 - 40 parts by weight of hexamethylene diisocyanate, 0.5 - 1.5 parts by weight of N,N - dimethylcyclohexylamine, 5 - 15 parts by weight of modified p - toluenesulfonylhydrazide microcapsules, 1 - 3 parts by weight of nucleating agent, 0.5 - 2 parts by weight of zinc dialkyldithiophosphate, 0.5 - 2 parts by weight of phenyl salicylate, and 0.5 - 2 parts by weight of polyoxyethylene sorbitan monooleate;

[0006] Among them, the modified p - toluenesulfonylhydrazide microcapsules are obtained by arylating p - toluenesulfonylhydrazide with aryl halides and then through microencapsulation; the aryl halide is o - chlorobenzene.

[0007] Preferably, the preparation process of the modified p - toluenesulfonylhydrazide microcapsules is as follows:

[0008] S1.1. Weigh the following components in parts by weight respectively: 10 - 20 parts by weight of p - toluenesulfonyl hydrazide, 20 - 30 parts by weight of acetonitrile, 10 - 30 parts by weight of aryl halide, 1 - 5 parts by weight of boron trifluoride diethyl ether complex, 20 - 30 parts by weight of ethanol, 5 - 15 parts by weight of fatty acid, 10 - 20 parts by weight of polyvinyl alcohol, and 1 - 5 parts by weight of glutaraldehyde;

[0009] S1.2. Dissolve p - toluenesulfonyl hydrazide in acetonitrile, stir at a speed of 300 - 500 rpm for 10 - 20 min, slowly add aryl halide, and stir at a speed of 200 - 300 rpm for 15 - 30 min; then add boron trifluoride diethyl ether complex. Under nitrogen protection, raise the temperature to 80 - 100 °C and stir for reaction at a speed of 200 - 300 rpm for 12 - 24 h; after the reaction is completed, let the reaction mixture cool to room temperature naturally, carry out suction filtration, rinse with hexane, and then dry at 50 - 60 °C for 6 - 8 h to obtain arylated p - toluenesulfonyl hydrazide;

[0010] The thermal stability of p - toluenesulfonyl hydrazide is relatively poor, and its initial decomposition temperature is generally around 105 °C. Through arylation reaction, an aryl group can be introduced into the molecular structure of p - toluenesulfonyl hydrazide to form a more stable chemical bond, thereby increasing its thermal decomposition temperature, enabling it to better meet the requirements of specific processing technologies such as high - temperature foaming, reducing the possibility of premature decomposition during processing, and facilitating more precise control of reactions such as foaming; after introducing the aryl group, the chemical stability of p - toluenesulfonyl hydrazide is enhanced, making it more stable in different chemical environments, less likely to undergo unnecessary chemical reactions due to the influence of substances such as acids and bases, enabling it to play a role in more complex chemical systems or usage environments, and at the same time improving the stability and reliability of the product during storage and use.

[0011] The properties of arylated p - toluenesulfonyl hydrazide in terms of polarity, solubility, etc. will change, thereby improving its compatibility with other substances, being able to mix more evenly with raw materials such as polyols and isocyanates to form a stable system, which is conducive to improving the quality and performance of the product and reducing problems such as phase separation and uneven foaming caused by poor compatibility.

[0012] S1.3. Dissolve arylated p - toluenesulfonyl hydrazide in ethanol, stir at a speed of 300 - 400 rpm at room temperature for 15 - 30 min, add fatty acid, and stir for reaction at a speed of 400 - 600 rpm at 30 - 50 °C for 6 - 12 h; after the reaction is completed, let the reaction mixture cool to room temperature naturally, filter to separate the solid product, rinse with ethanol, and then dry at 50 - 60 °C for 10 - 12 h to obtain modified p - toluenesulfonyl hydrazide containing fatty acid;

[0013] Fatty acids have the characteristics of being lipophilic and hydrophobic. One end of their molecules usually contains a long hydrocarbon chain, which can have a certain affinity with arylated p-toluenesulfonyl hydrazide; the other end can interact with the surrounding medium such as the polymer matrix through van der Waals forces and other interactions, thus playing a role similar to a bridge, promoting the better dispersion of arylated p-toluenesulfonyl hydrazide in the whole system, avoiding agglomeration phenomena, and helping to form a more uniform cell structure during subsequent foaming and other processes. On the one hand, during the foaming process, fatty acids can reduce the surface tension of the system, making it easier for gas to form tiny gas nuclei in the system, increasing the number of gas nucleation sites, and helping to form fine and uniform cells. On the other hand, after being adsorbed on the surface of the bubbles, fatty acids can play a certain stabilizing role, preventing the bubbles from bursting and merging during the growth process, making the generated foam more stable, and improving the quality of the foamed material.

[0014] Some fatty acids can have a certain synergistic effect with arylated p-toluenesulfonyl hydrazide during the heating process, forming a relatively stable complex or playing a role in blocking heat transfer, delaying the decomposition rate of arylated p-toluenesulfonyl hydrazide at high temperatures, further improving its thermal stability, ensuring efficient and stable foaming and other reactions within a suitable processing temperature range, and avoiding problems such as foaming failure or material property deterioration caused by premature decomposition.

[0015] S1.4. Disperse the modified p-toluenesulfonyl hydrazide containing fatty acids in deionized water and stir at a speed of 300 - 500 rpm for 10 - 20 min to form a stable suspension; dissolve polyvinyl alcohol in deionized water, heat to 80 - 90 °C and stir at a speed of 200 - 300 rpm until completely dissolved to obtain a polyvinyl alcohol solution with a concentration of 5 - 10%.

[0016] S1.5. Use a high-speed shearing device with a rotation speed of 10000 - 20000 rpm and a shearing time of 15 - 30 min. Add the suspension to the polyvinyl alcohol solution to form a fine water-in-oil emulsion. Add glutaraldehyde to the emulsion to form microcapsules; then filter and separate the microcapsules, wash them 3 - 5 times with deionized water, and dry the microcapsules at 30 - 50 °C for 12 - 24 h to obtain modified p-toluenesulfonyl hydrazide microcapsules.

[0017] Microencapsulation can provide a relatively stable environment for modified p-toluenesulfonyl hydrazide, reduce its direct contact with the external environment, thereby improving its thermal stability, making it less likely to decompose under high-temperature processing conditions, and helping to more precisely control its reactions during processes such as foaming; prevent modified p-toluenesulfonyl hydrazide from being affected by surrounding chemical substances, such as avoiding unnecessary chemical reactions with other additives, polymer matrices, etc., ensuring that it can maintain its own properties and functions in a complex chemical system, and improving the stability and reliability of the product during storage and use.

[0018] The modified p-toluenesulfonylhydrazide after microencapsulation has better fluidity and dispersibility, can be more evenly dispersed in the polymer matrix or other media, avoid agglomeration, and helps to form a more uniform and fine cell structure during the foaming process, thereby improving the quality and performance of the foamed material.

[0019] Preferably, in the step S1.2, the rate of slowly adding the aryl halide is 1-2 parts by weight per minute.

[0020] Preferably, in the step S1.3, the fatty acid is any one of stearic acid or palmitic acid.

[0021] Preferably, in the step S1.5, the thickness of the formed microcapsule is 1-5 μm.

[0022] On the other hand, the present invention provides a preparation process for a lightweight polyurethane shoe material for sports shoes, which is used for a lightweight polyurethane shoe material for sports shoes described in any one of the above, and includes the following steps:

[0023] S2.1: Weigh the following components in parts by weight respectively: 40-60 parts by weight of polyether polyol, 20-40 parts by weight of hexamethylene diisocyanate, 0.5-1.5 parts by weight of N,N-dimethylcyclohexylamine, 5-15 parts by weight of modified p-toluenesulfonylhydrazide microcapsule, 1-3 parts by weight of nucleating agent, 0.5-2 parts by weight of zinc dialkyldithiophosphate, 0.5-2 parts by weight of phenyl salicylate, and 0.5-2 parts by weight of polyoxyethylene sorbitan monooleate;

[0024] S2.2: Add the nucleating agent, zinc dialkyldithiophosphate and phenyl salicylate to the polyether polyol in sequence, stir at a speed of 300-500 rpm for 10-20 min at room temperature to ensure that each component is evenly dispersed; slowly add polyoxyethylene sorbitan monooleate, and continue to stir at a speed of 300-500 rpm for 5-10 min; under nitrogen protection, add N,N-dimethylcyclohexylamine, and stir at a speed of 200-300 rpm for 5-10 min to form a uniform polyol mixture;

[0025] Nucleating agents can provide more nucleation sites for the formation of bubbles, making it easier for gas to form tiny and uniformly distributed bubble nuclei in the system. During foaming, the gas generated by the foaming agent will grow around these nucleation sites to form cell pores, which helps to produce a finer and more uniform cell structure. Such a good cell structure is of great significance for improving the cushioning performance, elasticity of the shoe material and reducing the overall density of the shoe material, making the sports shoes more comfortable and lightweight to wear; nucleating agents have a certain thermal stability function. During the processing and subsequent use of the shoe material, when encountering an increase in temperature, it can delay the thermal decomposition rate of the polyurethane material, improve the material's tolerance to high-temperature environments, and ensure that the shoe material can still maintain stable physical and chemical properties when worn in a high-temperature environment such as in summer or when heat accumulates after strenuous exercise, without becoming too soft, deformed or losing its original function too quickly.

[0026] S2.3. Add hexamethylene diisocyanate to the polyol mixture, raise the temperature to 70 - 80 °C, and continuously stir at a speed of 1000 - 2000 rpm for 3 - 5 min to ensure sufficient mixing of the two phases; add the modified p-toluenesulfonyl hydrazide microcapsules and stir to ensure its uniform dispersion in the mixture.

[0027] S2.4. Pour the mixture in S2.3 into a mold, and place the mold in an oven to allow the material to fully foam and cure; after foaming is completed, naturally cool to room temperature to obtain a lightweight polyurethane shoe material for sports shoes.

[0028] Preferably, in S2.2, the nucleating agent is any one of zinc stearate or calcium stearate.

[0029] Preferably, in S2.2, the addition rate of polyoxyethylene sorbitan monooleate is 0.5 - 1 part by weight per minute.

[0030] Preferably, in S2.3, the stirring speed for adding the microcapsules is 500 - 1000 rpm, and the stirring time is 15 - 20 min.

[0031] Preferably, in S2.4, the curing temperature is 80 - 100 °C, and the curing time is 10 - 30 min.

[0032] Compared with the prior art, the beneficial effects of the present invention:

[0033] 1. In the lightweight polyurethane shoe material for sports shoes and its preparation process, aryl halides are added. Since it can increase the thermal decomposition temperature of p-toluenesulfonyl hydrazide, making it less likely to decompose prematurely under high-temperature processing conditions, it helps to more precisely control the reaction processes such as foaming, ensuring better foaming effect of the shoe material, forming a uniform and ideal cell structure, and improving the cushioning performance and overall quality of the shoe material.

[0034] 2. In the lightweight polyurethane shoe material for sports shoes and its preparation process, fatty acid is added. Since it can reduce the surface tension of the system, make it easier for gas to form tiny bubble nuclei in the system, increase the number of bubble nucleation sites, and help generate a finer and more uniform cell structure. After the bubbles are formed, the fatty acid can also adsorb on the surface of the bubbles, playing a role in stabilizing the bubbles, preventing the bubbles from bursting and merging during the growth process, and enabling the shoe material to continuously exert good buffering and supporting functions during long-term use. Detailed implementation mode

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] The present invention provides a lightweight polyurethane shoe material for sports shoes, which includes the following components: 40 - 60 parts by weight of polyether polyol, 20 - 40 parts by weight of hexamethylene diisocyanate, 0.5 - 1.5 parts by weight of N,N - dimethylcyclohexylamine, 5 - 15 parts by weight of modified p - toluenesulfonylhydrazide microcapsule, 1 - 3 parts by weight of nucleating agent, 0.5 - 2 parts by weight of zinc dialkyldithiophosphate, 0.5 - 2 parts by weight of phenyl salicylate, and 0.5 - 2 parts by weight of polyoxyethylene sorbitan monooleate;

[0037] Among them, the modified p - toluenesulfonylhydrazide microcapsule is obtained by carrying out arylation reaction on p - toluenesulfonylhydrazide with aryl halide and then through microencapsulation; the aryl halide is o - chlorobenzene.

[0038] The fatty acid is any one of stearic acid or palmitic acid, preferably stearic acid.

[0039] The nucleating agent is any one of zinc stearate or calcium stearate, preferably zinc stearate.

[0040] Example 1: A lightweight polyurethane shoe material for sports shoes and its preparation process, including the following steps:

[0041] S2.1. Weigh the following components in parts by weight respectively: 50 parts by weight of polyether polyol, 30 parts by weight of hexamethylene diisocyanate, 1 part by weight of N,N - dimethylcyclohexylamine, 10 parts by weight of modified p - toluenesulfonylhydrazide microcapsule, 2 parts by weight of zinc stearate, 1.5 parts by weight of zinc dialkyldithiophosphate, 1.5 parts by weight of phenyl salicylate, and 1.5 parts by weight of polyoxyethylene sorbitan monooleate;

[0042] S2.2. Add zinc stearate, zinc dialkyldithiophosphate, and phenyl salicylate to the polyether polyol in sequence, and stir at a speed of 500 rpm for 20 min at room temperature to ensure uniform dispersion of each component; add polyoxyethylene sorbitan monooleate at a speed of 1 part by weight per minute, and continue to stir at a speed of 500 rpm for 10 min; under nitrogen protection, add N,N-dimethylcyclohexylamine and stir at a speed of 300 rpm for 10 min to form a uniform polyol mixture;

[0043] S2.3. Add hexamethylene diisocyanate to the polyol mixture, raise the temperature to 80 °C, and continuously stir at a speed of 1500 rpm for 5 min to ensure full mixing of the two phases; add the modified p-toluenesulfonyl hydrazide microcapsules and stir at a speed of 800 rpm for 20 min to ensure its uniform dispersion in the mixture;

[0044] S2.4. Pour the mixture in S2.3 into a mold, place the mold in an oven at 100 °C, and keep it for 30 min to allow the material to foam and cure fully; after foaming is completed, cool it naturally to room temperature to obtain a lightweight polyurethane shoe material for sports shoes.

[0045] The preparation process of the modified p-toluenesulfonyl hydrazide microcapsules is as follows:

[0046] S1.1. Weigh the following components by weight: 15 parts by weight of p-toluenesulfonyl hydrazide, 25 parts by weight of acetonitrile, 15 parts by weight of o-chlorobenzene, 3 parts by weight of boron trifluoride ether complex, 25 parts by weight of ethanol, 10 parts by weight of stearic acid, 15 parts by weight of polyvinyl alcohol, and 3 parts by weight of glutaraldehyde;

[0047] S1.2. Dissolve p-toluenesulfonyl hydrazide in acetonitrile, stir at a speed of 500 rpm for 20 min, add o-chlorobenzene at a speed of 1-2 parts by weight per minute, and stir at a speed of 300 rpm for 15-30 min; then add boron trifluoride ether complex, under nitrogen protection, raise the temperature to 80 °C, and stir and react at a speed of 200 rpm for 20 h; after the reaction is completed, allow the reaction mixture to cool naturally to room temperature, perform suction filtration, rinse with hexane, and then dry at 60 °C for 8 h to obtain arylated p-toluenesulfonyl hydrazide;

[0048] S1.3. Dissolve the arylated p-toluenesulfonyl hydrazide in ethanol, stir at a speed of 400 rpm for 30 min at room temperature, add stearic acid, and stir and react at a speed of 500 rpm at 40 °C for 12 h; after the reaction is completed, allow the reaction mixture to cool naturally to room temperature, filter to separate the solid product, rinse with ethanol, and then dry at 50 °C for 10 h to obtain modified p-toluenesulfonyl hydrazide containing fatty acids;

[0049] S1.4. Disperse the modified p-toluenesulfonyl hydrazide containing fatty acids in deionized water and stir at a speed of 500 rpm for 20 min to form a stable suspension; dissolve polyvinyl alcohol in deionized water, heat to 90 °C and stir at a speed of 300 rpm until completely dissolved to obtain a polyvinyl alcohol solution with a concentration of 8%.

[0050] S1.5. Using a high-speed shearing device with a rotation speed of 10,000 rpm and a shearing time of 30 min, add the suspension to the polyvinyl alcohol solution to form a fine water-in-oil emulsion. Add glutaraldehyde to the emulsion to form microcapsules with a thickness of 4 μm; then filter and separate the microcapsules, rinse them 5 times with deionized water, and dry the microcapsules at 30 °C for 24 h to obtain modified p-toluenesulfonyl hydrazide microcapsules.

[0051] Example 2: A lightweight polyurethane shoe material for sports shoes and its preparation process, including the following steps:

[0052] S2.1. Weigh the following components by weight: 50 parts by weight of polyether polyol, 30 parts by weight of hexamethylene diisocyanate, 1 part by weight of N,N-dimethylcyclohexylamine, 10 parts by weight of modified p-toluenesulfonyl hydrazide microcapsules, 2 parts by weight of zinc stearate, 1.5 parts by weight of zinc dialkyldithiophosphate, 1.5 parts by weight of phenyl salicylate, and 1.5 parts by weight of polyoxyethylene sorbitan monooleate.

[0053] S2.2. Add zinc stearate, zinc dialkyldithiophosphate, and phenyl salicylate to the polyether polyol in sequence, stir at a speed of 500 rpm at room temperature for 20 min to ensure that each component is evenly dispersed; add polyoxyethylene sorbitan monooleate at a rate of 1 part by weight per minute and continue to stir at a speed of 500 rpm for 10 min; under nitrogen protection, add N,N-dimethylcyclohexylamine and stir at a speed of 300 rpm for 10 min to form a uniform polyol mixture.

[0054] S2.3. Add hexamethylene diisocyanate to the polyol mixture, raise the temperature to 80 °C, and continuously stir at a speed of 1500 rpm for 5 min to ensure full mixing of the two phases; add the modified p-toluenesulfonyl hydrazide microcapsules and stir at a speed of 800 rpm for 20 min to ensure its uniform dispersion in the mixture.

[0055] S2.4. Pour the mixture in S2.3 into a mold, place the mold in an oven at 100 °C, and keep it for 30 min to allow the material to fully foam and cure; after foaming is completed, naturally cool to room temperature to obtain a lightweight polyurethane shoe material for sports shoes.

[0056] The preparation process of the modified p-toluenesulfonyl hydrazide microcapsules is as follows:

[0057] S1.1. Weigh the following components by weight respectively: 15 parts by weight of p-toluenesulfonyl hydrazide, 25 parts by weight of acetonitrile, 21 parts by weight of o-chlorobenzene, 3 parts by weight of boron trifluoride diethyl ether complex, 25 parts by weight of ethanol, 10 parts by weight of stearic acid, 15 parts by weight of polyvinyl alcohol, and 3 parts by weight of glutaraldehyde;

[0058] S1.2. Dissolve p-toluenesulfonyl hydrazide in acetonitrile, stir at a speed of 500 rpm for 20 min, add o-chlorobenzene at a speed of 1 - 2 parts by weight per minute, and stir at a speed of 300 rpm for 15 - 30 min; then add boron trifluoride diethyl ether complex. Under nitrogen protection, raise the temperature to 80 °C and stir for 20 h at a speed of 200 rpm; after the reaction is completed, let the reaction mixture cool naturally to room temperature, perform suction filtration, rinse with hexane, and then dry at 60 °C for 8 h to obtain arylated p-toluenesulfonyl hydrazide;

[0059] S1.3. Dissolve the arylated p-toluenesulfonyl hydrazide in ethanol, stir at a speed of 400 rpm at room temperature for 30 min, add stearic acid, and stir at a speed of 500 rpm at 40 °C for 12 h; after the reaction is completed, let the reaction mixture cool naturally to room temperature, filter to separate the solid product, rinse with ethanol, and then dry at 50 °C for 10 h to obtain modified p-toluenesulfonyl hydrazide containing fatty acid;

[0060] S1.4. Disperse the modified p-toluenesulfonyl hydrazide containing fatty acid in deionized water and stir at a speed of 500 rpm for 20 min to form a stable suspension; dissolve polyvinyl alcohol in deionized water, heat to 90 °C and stir at a speed of 300 rpm until completely dissolved to obtain a polyvinyl alcohol solution with a concentration of 8%;

[0061] S1.5. Using a high-speed shearing device with a rotation speed of 10000 rpm and a shearing time of 30 min, add the suspension to the polyvinyl alcohol solution to form a fine water-in-oil emulsion. Add glutaraldehyde to the emulsion to form microcapsules with a thickness of 4 μm; then filter and separate the microcapsules, rinse 5 times with deionized water, and dry the microcapsules at 30 °C for 24 h to obtain modified p-toluenesulfonyl hydrazide microcapsules.

[0062] Example 3: A lightweight polyurethane shoe material for sports shoes and its preparation process, including the following steps:

[0063] S2.1. Weigh the following components by weight respectively: 50 parts by weight of polyether polyol, 30 parts by weight of hexamethylene diisocyanate, 1 part by weight of N,N-dimethylcyclohexylamine, 10 parts by weight of modified p-toluenesulfonyl hydrazide microcapsules, 2 parts by weight of zinc stearate, 1.5 parts by weight of zinc dialkyldithiophosphate, 1.5 parts by weight of phenyl salicylate, and 1.5 parts by weight of polyoxyethylene sorbitan monooleate;

[0064] S2.2. Add zinc stearate, zinc dialkyldithiophosphate, and phenyl salicylate to the polyether polyol in sequence. Stir at a speed of 500 rpm for 20 min at room temperature to ensure uniform dispersion of each component. Add polyoxyethylene sorbitan monooleate at a speed of 1 part by weight per minute, and continue to stir at a speed of 500 rpm for 10 min. Under nitrogen protection, add N,N-dimethylcyclohexylamine and stir at a speed of 300 rpm for 10 min to form a uniform polyol mixture.

[0065] S2.3. Add hexamethylene diisocyanate to the polyol mixture, raise the temperature to 80 °C, and continuously stir at a speed of 1500 rpm for 5 min to ensure sufficient mixing of the two phases. Add the modified p-toluenesulfonyl hydrazide microcapsules and stir at a speed of 800 rpm for 20 min to ensure its uniform dispersion in the mixture.

[0066] S2.4. Pour the mixture in S2.3 into a mold, place the mold in an oven at 100 °C, and keep it for 30 min to allow the material to foam and cure sufficiently. After foaming is completed, cool it naturally to room temperature to obtain a lightweight polyurethane shoe material for sports shoes.

[0067] The preparation process of the modified p-toluenesulfonyl hydrazide microcapsules is as follows:

[0068] S1.1. Weigh the following components by weight: 15 parts by weight of p-toluenesulfonyl hydrazide, 25 parts by weight of acetonitrile, 24 parts by weight of o-chlorobenzene, 3 parts by weight of boron trifluoride ether complex, 25 parts by weight of ethanol, 10 parts by weight of stearic acid, 15 parts by weight of polyvinyl alcohol, and 3 parts by weight of glutaraldehyde.

[0069] S1.2. Dissolve p-toluenesulfonyl hydrazide in acetonitrile, stir at a speed of 500 rpm for 20 min, add o-chlorobenzene at a speed of 1 - 2 parts by weight per minute, and stir at a speed of 300 rpm for 15 - 30 min. Then add the boron trifluoride ether complex. Under nitrogen protection, raise the temperature to 80 °C and stir for 20 h at a speed of 200 rpm. After the reaction is completed, let the reaction mixture cool naturally to room temperature, perform suction filtration, rinse with hexane, and then dry at 60 °C for 8 h to obtain arylated p-toluenesulfonyl hydrazide.

[0070] S1.3. Dissolve the arylated p-toluenesulfonyl hydrazide in ethanol, stir at a speed of 400 rpm for 30 min at room temperature, add stearic acid, and stir at a speed of 500 rpm at 40 °C for 12 h. After the reaction is completed, let the reaction mixture cool naturally to room temperature, filter to separate the solid product, rinse with ethanol, and then dry at 50 °C for 10 h to obtain modified p-toluenesulfonyl hydrazide containing fatty acids.

[0071] S1.4. Disperse the modified p-toluenesulfonyl hydrazide containing fatty acids in deionized water, stir at a speed of 500 rpm for 20 min to form a stable suspension; dissolve polyvinyl alcohol in deionized water, heat to 90 °C and stir at a speed of 300 rpm until completely dissolved to obtain a polyvinyl alcohol solution with a concentration of 8%.

[0072] S1.5. Use a high-speed shearing device with a rotation speed of 10,000 rpm and a shearing time of 30 min. Add the suspension to the polyvinyl alcohol solution to form a fine water-in-oil emulsion. Add glutaraldehyde to the emulsion to form microcapsules with a thickness of 4 μm; then filter and separate the microcapsules, rinse them 5 times with deionized water, and dry the microcapsules at 30 °C for 24 h to obtain modified p-toluenesulfonyl hydrazide microcapsules.

[0073] Example 4: A lightweight polyurethane shoe material for sports shoes and its preparation process, including the following steps:

[0074] S2.1. Weigh the following components by weight: 50 parts by weight of polyether polyol, 30 parts by weight of hexamethylene diisocyanate, 1 part by weight of N,N-dimethylcyclohexylamine, 10 parts by weight of modified p-toluenesulfonyl hydrazide microcapsules, 2 parts by weight of zinc stearate, 1.5 parts by weight of zinc dialkyldithiophosphate, 1.5 parts by weight of phenyl salicylate, and 1.5 parts by weight of polyoxyethylene sorbitan monooleate;

[0075] S2.2. Add zinc stearate, zinc dialkyldithiophosphate, and phenyl salicylate to the polyether polyol in sequence, stir at a speed of 500 rpm for 20 min at room temperature to ensure uniform dispersion of each component; add polyoxyethylene sorbitan monooleate at a speed of 1 part by weight per minute, and continue to stir at a speed of 500 rpm for 10 min; under nitrogen protection, add N,N-dimethylcyclohexylamine and stir at a speed of 300 rpm for 10 min to form a uniform polyol mixture;

[0076] S2.3. Add hexamethylene diisocyanate to the polyol mixture, raise the temperature to 80 °C, and continuously stir at a speed of 1500 rpm for 5 min to ensure sufficient mixing of the two phases; add the modified p-toluenesulfonyl hydrazide microcapsules and stir at a speed of 800 rpm for 20 min to ensure its uniform dispersion in the mixture;

[0077] S2.4. Pour the mixture in S2.3 into a mold, place the mold in an oven at 100 °C, and keep it for 30 min to allow the material to fully foam and cure; after foaming is completed, naturally cool to room temperature to obtain a lightweight polyurethane shoe material for sports shoes.

[0078] The preparation process of the modified p-toluenesulfonyl hydrazide microcapsules is as follows:

[0079] S1.1: Weigh the following components by weight respectively: 15 parts by weight of p-toluenesulfonyl hydrazide, 25 parts by weight of acetonitrile, 30 parts by weight of o-chlorobenzene, 3 parts by weight of boron trifluoride diethyl ether complex, 25 parts by weight of ethanol, 10 parts by weight of stearic acid, 15 parts by weight of polyvinyl alcohol, and 3 parts by weight of glutaraldehyde;

[0080] S1.2: Dissolve p-toluenesulfonyl hydrazide in acetonitrile, stir at a speed of 500 rpm for 20 min, add o-chlorobenzene at a speed of 1 - 2 parts by weight per minute, and stir at a speed of 300 rpm for 15 - 30 min; then add boron trifluoride diethyl ether complex. Under nitrogen protection, raise the temperature to 80 °C and stir and react at a speed of 200 rpm for 20 h; after the reaction is completed, let the reaction mixture cool naturally to room temperature, perform suction filtration, rinse with hexane, and then dry at 60 °C for 8 h to obtain arylated p-toluenesulfonyl hydrazide;

[0081] S1.3: Dissolve the arylated p-toluenesulfonyl hydrazide in ethanol, stir at a speed of 400 rpm at room temperature for 30 min, add stearic acid, and stir and react at a speed of 500 rpm at 40 °C for 12 h; after the reaction is completed, let the reaction mixture cool naturally to room temperature, filter to separate the solid product, rinse with ethanol, and then dry at 50 °C for 10 h to obtain modified p-toluenesulfonyl hydrazide containing fatty acid;

[0082] S1.4: Disperse the modified p-toluenesulfonyl hydrazide containing fatty acid in deionized water, stir at a speed of 500 rpm for 20 min to form a stable suspension; dissolve polyvinyl alcohol in deionized water, heat to 90 °C and stir at a speed of 300 rpm until completely dissolved to obtain a polyvinyl alcohol solution with a concentration of 8%;

[0083] S1.5: Use a high-speed shearing device with a rotation speed of 10000 rpm and a shearing time of 30 min to add the suspension to the polyvinyl alcohol solution to form a fine water-in-oil emulsion. Add glutaraldehyde to the emulsion to form microcapsules with a thickness of 4 μm; then filter and separate the microcapsules, rinse 5 times with deionized water, and dry the microcapsules at 30 °C for 24 h to obtain modified p-toluenesulfonyl hydrazide microcapsules.

[0084] Example 5: A lightweight polyurethane shoe material for sports shoes and its preparation process, including the following steps:

[0085] S2.1. Weigh the following components by weight respectively: 40 parts by weight of polyether polyol, 20 parts by weight of hexamethylene diisocyanate, 0.5 part by weight of N,N-dimethylcyclohexylamine, 8 parts by weight of modified p-toluenesulfonyl hydrazide microcapsules, 1 part by weight of zinc stearate, 0.5 part by weight of zinc dialkyldithiophosphate, 0.5 part by weight of phenyl salicylate, and 0.5 part by weight of polyoxyethylene sorbitan monooleate;

[0086] S2.2. Add zinc stearate, zinc dialkyldithiophosphate and phenyl salicylate to polyether polyol in sequence, stir at a speed of 500 rpm for 20 min at room temperature to ensure that each component is evenly dispersed; add polyoxyethylene sorbitan monooleate at a speed of 1 part by weight per minute, and continue to stir at a speed of 500 rpm for 10 min; under nitrogen protection, add N,N-dimethylcyclohexylamine and stir at a speed of 300 rpm for 10 min to form a uniform polyol mixture;

[0087] S2.3. Add hexamethylene diisocyanate to the polyol mixture, raise the temperature to 80 °C, and continuously stir at a speed of 1500 rpm for 5 min to ensure full mixing of the two phases; add the modified p-toluenesulfonyl hydrazide microcapsules and stir at a speed of 800 rpm for 20 min to ensure its uniform dispersion in the mixture;

[0088] S2.4. Pour the mixture in S2.3 into a mold, place the mold in an oven at 100 °C and keep it for 30 min to allow the material to fully foam and cure; after foaming is completed, cool it naturally to room temperature to obtain a lightweight polyurethane shoe material for sports shoes.

[0089] The preparation process of the modified p-toluenesulfonyl hydrazide microcapsules is as follows:

[0090] S1.1. Weigh the following components by weight respectively: 10 parts by weight of p-toluenesulfonyl hydrazide, 20 parts by weight of acetonitrile, 16 parts by weight of o-chlorobenzene, 1 part by weight of boron trifluoride diethyl ether complex, 20 parts by weight of ethanol, 5 parts by weight of stearic acid, 10 parts by weight of polyvinyl alcohol, and 1 part by weight of glutaraldehyde;

[0091] S1.2. Dissolve p-toluenesulfonyl hydrazide in acetonitrile, stir at a speed of 500 rpm for 20 min, add o-chlorobenzene at a speed of 1 - 2 parts by weight per minute, and stir at a speed of 300 rpm for 15 - 30 min; then add the boron trifluoride diethyl ether complex, under nitrogen protection, raise the temperature to 80 °C and stir and react at a speed of 200 rpm for 20 h; after the reaction is completed, let the reaction mixture cool naturally to room temperature, carry out suction filtration, rinse with hexane, and then dry at 60 °C for 8 h to obtain arylated p-toluenesulfonyl hydrazide;

[0092] S1.3. Dissolve the arylated p-toluenesulfonylhydrazide in ethanol, stir at a speed of 400 rpm for 30 min at room temperature, add stearic acid, and stir the reaction at a speed of 500 rpm at 40 °C for 12 h; after the reaction is completed, let the reaction mixture cool naturally to room temperature, filter to separate the solid product, rinse with ethanol, and then dry at 50 °C for 10 h to obtain modified p-toluenesulfonylhydrazide containing fatty acids;

[0093] S1.4. Disperse the modified p-toluenesulfonylhydrazide containing fatty acids in deionized water and stir at a speed of 500 rpm for 20 min to form a stable suspension; dissolve polyvinyl alcohol in deionized water, heat to 90 °C and stir at a speed of 300 rpm until completely dissolved to obtain a 5% polyvinyl alcohol solution;

[0094] S1.5. Using a high-speed shearing device with a rotation speed of 10,000 rpm and a shearing time of 30 min, add the suspension to the polyvinyl alcohol solution to form a fine water-in-oil emulsion, add glutaraldehyde to the emulsion to form microcapsules with a thickness of 4 μm; then filter to separate the microcapsules, rinse 5 times with deionized water, and dry the microcapsules at 30 °C for 24 h to obtain modified p-toluenesulfonylhydrazide microcapsules.

[0095] Example 6: A lightweight polyurethane shoe material for sports shoes and its preparation process, including the following steps:

[0096] S2.1. Weigh the following components by weight: 40 parts by weight of polyether polyol, 20 parts by weight of hexamethylene diisocyanate, 0.5 part by weight of N,N-dimethylcyclohexylamine, 11 parts by weight of modified p-toluenesulfonylhydrazide microcapsules, 1 part by weight of zinc stearate, 0.5 part by weight of zinc dialkyldithiophosphate, 0.5 part by weight of phenyl salicylate, 0.5 part by weight of polyoxyethylene sorbitan monooleate;

[0097] S2.2. Add zinc stearate, zinc dialkyldithiophosphate, and phenyl salicylate to the polyether polyol in sequence, stir at a speed of 500 rpm for 20 min at room temperature to ensure uniform dispersion of each component; add polyoxyethylene sorbitan monooleate at a speed of 1 part by weight per minute, and continue to stir at a speed of 500 rpm for 10 min; under nitrogen protection, add N,N-dimethylcyclohexylamine and stir at a speed of 300 rpm for 10 min to form a uniform polyol mixture;

[0098] S2.3. Add hexamethylene diisocyanate to the polyol mixture, raise the temperature to 80 °C, and continuously stir at a speed of 1500 rpm for 5 min to ensure full mixing of the two phases; add the modified p-toluenesulfonylhydrazide microcapsules and stir at a speed of 800 rpm for 20 min to ensure its uniform dispersion in the mixture;

[0099] S2.4. Pour the mixture in S2.3 into a mold, place the mold in an oven at 100 °C, and keep it for 30 min to allow the material to fully foam and cure; after the foaming is completed, naturally cool it to room temperature to obtain a lightweight polyurethane shoe material for sports shoes.

[0100] The preparation process of the modified p-toluenesulfonyl hydrazide microcapsules is as follows:

[0101] S1.1. Weigh the following components by weight: 10 parts by weight of p-toluenesulfonyl hydrazide, 20 parts by weight of acetonitrile, 16 parts by weight of o-chlorobenzene, 1 part by weight of boron trifluoride diethyl ether complex, 20 parts by weight of ethanol, 5 parts by weight of stearic acid, 10 parts by weight of polyvinyl alcohol, and 1 part by weight of glutaraldehyde;

[0102] S1.2. Dissolve p-toluenesulfonyl hydrazide in acetonitrile, stir at a speed of 500 rpm for 20 min, add o-chlorobenzene at a speed of 1 - 2 parts by weight per minute, and stir at a speed of 300 rpm for 15 - 30 min; then add boron trifluoride diethyl ether complex, under nitrogen protection, raise the temperature to 80 °C, and stir and react at a speed of 200 rpm for 20 h; after the reaction is completed, allow the reaction mixture to naturally cool to room temperature, perform suction filtration, rinse with hexane, and then dry at 60 °C for 8 h to obtain arylated p-toluenesulfonyl hydrazide;

[0103] S1.3. Dissolve the arylated p-toluenesulfonyl hydrazide in ethanol, stir at a speed of 400 rpm at room temperature for 30 min, add stearic acid, and stir and react at a speed of 500 rpm at 40 °C for 12 h; after the reaction is completed, allow the reaction mixture to naturally cool to room temperature, filter and separate the solid product, rinse with ethanol, and then dry at 50 °C for 10 h to obtain modified p-toluenesulfonyl hydrazide containing fatty acids;

[0104] S1.4. Disperse the modified p-toluenesulfonyl hydrazide containing fatty acids in deionized water, stir at a speed of 500 rpm for 20 min to form a stable suspension; dissolve polyvinyl alcohol in deionized water, heat to 90 °C and stir at a speed of 300 rpm until completely dissolved to obtain a 5% polyvinyl alcohol solution;

[0105] S1.5. Using a high-speed shearing device with a rotation speed of 10000 rpm and a shearing time of 30 min, add the suspension to the polyvinyl alcohol solution to form a fine water-in-oil emulsion, add glutaraldehyde to the emulsion to form microcapsules with a thickness of 4 μm; then filter and separate the microcapsules, rinse 5 times with deionized water, and dry the microcapsules at 30 °C for 24 h to obtain modified p-toluenesulfonyl hydrazide microcapsules.

[0106] Example 7: A lightweight polyurethane shoe material for sports shoes and its preparation process, including the following steps:

[0107] S2.1. Weigh the following components by weight respectively: 40 parts by weight of polyether polyol, 20 parts by weight of hexamethylene diisocyanate, 0.5 part by weight of N,N-dimethylcyclohexylamine, 14 parts by weight of modified p-toluenesulfonylhydrazide microcapsules, 1 part by weight of zinc stearate, 0.5 part by weight of zinc dialkyldithiophosphate, 0.5 part by weight of phenyl salicylate, and 0.5 part by weight of polyoxyethylene sorbitan monooleate;

[0108] S2.2. Add zinc stearate, zinc dialkyldithiophosphate and phenyl salicylate to the polyether polyol in sequence, and stir at a speed of 500 rpm for 20 min at room temperature to ensure that each component is evenly dispersed; add polyoxyethylene sorbitan monooleate at a speed of 1 part by weight per minute, and continue to stir at a speed of 500 rpm for 10 min; under nitrogen protection, add N,N-dimethylcyclohexylamine and stir at a speed of 300 rpm for 10 min to form a uniform polyol mixture;

[0109] S2.3. Add hexamethylene diisocyanate to the polyol mixture, raise the temperature to 80 °C, and continuously stir at a speed of 1500 rpm for 5 min to ensure full mixing of the two phases; add the modified p-toluenesulfonylhydrazide microcapsules and stir at a speed of 800 rpm for 20 min to ensure its uniform dispersion in the mixture;

[0110] S2.4. Pour the mixture in S2.3 into a mold, put the mold into an oven at 100 °C, and keep it for 30 min to make the material fully foam and cure; after the foaming is completed, naturally cool it to room temperature to obtain a lightweight polyurethane shoe material for sports shoes.

[0111] The preparation process of the modified p-toluenesulfonylhydrazide microcapsules is as follows:

[0112] S1.1. Weigh the following components by weight respectively: 10 parts by weight of p-toluenesulfonylhydrazide, 20 parts by weight of acetonitrile, 16 parts by weight of o-chlorobenzene, 1 part by weight of boron trifluoride ether complex, 20 parts by weight of ethanol, 5 parts by weight of stearic acid, 10 parts by weight of polyvinyl alcohol, and 1 part by weight of glutaraldehyde;

[0113] S1.2. Dissolve p-toluenesulfonylhydrazide in acetonitrile, stir at a speed of 500 rpm for 20 min, add o-chlorobenzene at a speed of 1 - 2 parts by weight per minute, and stir at a speed of 300 rpm for 15 - 30 min; then add the boron trifluoride ether complex, under nitrogen protection, raise the temperature to 80 °C, and stir and react at a speed of 200 rpm for 20 h; after the reaction is completed, let the reaction mixture naturally cool to room temperature, carry out suction filtration, wash with hexane, and then dry at 60 °C for 8 h to obtain arylated p-toluenesulfonylhydrazide;

[0114] S1.3. Dissolve the arylated p-toluenesulfonylhydrazide in ethanol, stir at a speed of 400 rpm for 30 min at room temperature, add stearic acid, and stir and react at a speed of 500 rpm at 40 °C for 12 h; after the reaction is completed, allow the reaction mixture to cool naturally to room temperature, filter to separate the solid product, rinse with ethanol, and then dry at 50 °C for 10 h to obtain modified p-toluenesulfonylhydrazide containing fatty acid;

[0115] S1.4. Disperse the modified p-toluenesulfonylhydrazide containing fatty acid in deionized water, stir at a speed of 500 rpm for 20 min to form a stable suspension; dissolve polyvinyl alcohol in deionized water, heat to 90 °C and stir at a speed of 300 rpm until completely dissolved to obtain a 5% polyvinyl alcohol solution;

[0116] S1.5. Using a high-speed shearing device with a rotation speed of 10,000 rpm and a shearing time of 30 min, add the suspension to the polyvinyl alcohol solution to form a fine water-in-oil emulsion, add glutaraldehyde to the emulsion to form microcapsules with a thickness of 4 μm; then filter and separate the microcapsules, rinse 5 times with deionized water, and dry the microcapsules at 30 °C for 24 h to obtain modified p-toluenesulfonylhydrazide microcapsules.

[0117] Comparative Example 1: Using the method of Example 3, without using modified p-toluenesulfonylhydrazide microcapsules, directly use p-toluenesulfonylhydrazide to prepare lightweight polyurethane shoe materials for sports shoes.

[0118] Comparative Example 2: Using the method of Example 3, in the preparation process of modified p-toluenesulfonylhydrazide microcapsules, remove the fatty acid.

[0119] Comparative Example 3: Using the method of Example 3, remove the nucleating agent.

[0120] A lightweight polyurethane shoe material for sports shoes prepared by the modified p-toluenesulfonylhydrazide microcapsules of the present invention, wherein the performance index inspection items and inspection standards of the lightweight polyurethane shoe material for sports shoes are as follows:

[0121] Referring to the national standard GB / T 6343-2009, cut a specimen with dimensions of 100 mm × 100 mm × original thickness from the material to be tested, ensure that the shape of the specimen is regular and the surface is flat and undamaged; accurately measure the length, width and height of the specimen using a measuring tool with an accuracy of 0.1 mm, and calculate its volume; weigh the specimen using an electronic balance with an accuracy of not less than 0.1 g; calculate the density of the specimen through the formula. Materials with lower density can provide sufficient elasticity and cushioning performance while maintaining a lighter mass.

[0122] First, accurately measure the volume occupied by the liquid or solid raw material before foaming, then foam it. After the foaming is completed, put the foam into a container of known volume, and measure the total volume of the foam and the medium by adding a medium (such as water). The ratio of the two volumes is the foaming ratio. A higher foaming ratio should enable the material to achieve a higher volume expansion while ensuring sufficient mechanical strength, thereby reducing weight.

[0123] According to the above standards, the lightweight polyurethane shoe materials for sports shoes prepared in the above Examples 1-7 and Comparative Examples 1-3 were tested, and the obtained data are shown in Table 1:

[0124] Table 1 Performance data of lightweight polyurethane shoe materials for sports shoes of Examples 1-7 and Comparative Examples 1-3

[0125]

[0126] It can be seen from Examples 1-4 that: when the mass ratio of aryl halide to p-toluenesulfonyl hydrazide in the modified p-toluenesulfonyl hydrazide microcapsules gradually increases, the density of the polyurethane shoe material gradually decreases, and the foaming rate gradually increases; however, when the mass ratio of aryl halide to p-toluenesulfonyl hydrazide reaches a certain value, the density of the polyurethane shoe material gradually increases, and the foaming rate gradually decreases. It can be seen that with the increase of the mass ratio of aryl halide, the density and foaming rate of the polyurethane shoe material are improved, but excessive increase may increase the density of the polyurethane shoe material and reduce the foaming rate of the polyurethane shoe material;

[0127] Specifically, after participating in the reaction, the aromatic halides will be embedded in the polyurethane molecular chain structure or enhance the flexibility of the polyurethane molecular chain to a certain extent. The molecular chains with better flexibility are easier to be stretched when the gas is generated and expanded, and will not form a major obstacle to the growth of the bubbles. They can accommodate more gas, which is conducive to the growth of the bubbles, thereby increasing the foaming ratio and reducing the overall density of the material. More aromatic halides may change the distribution of cross-linking points or the degree of cross-linking, and may increase the distance between the cross-linking points appropriately, and increase the activity space of the molecular chain segments between the cross-linking points. In this way, during foaming, it is easier for the gas to diffuse and aggregate between the molecular chains to form bubbles, and the bubbles are relatively less constrained during the growth process, which helps to increase the foaming ratio and reduce the density.

[0128] The substances produced by the decomposition of p-toluenesulfonyl hydrazide and the aromatic halide itself or its reaction products can serve as nucleation sites for the formation of pores during the foaming process. When the mass ratio gradually increases, the number of nucleation sites will increase accordingly, providing more starting positions for the gas to gather and form pores, so that the pores can be produced more densely and evenly. On the basis of the same mass of material, the total volume of the pores finally formed is larger, which increases the foaming ratio and correspondingly reduces the density of the material.

[0129] Furthermore, by comparing Examples 5-7, it can be seen that: when other components remain unchanged, only when the proportion of modified p-toluenesulfonyl hydrazide microcapsules gradually increases, the density of the polyurethane shoe material gradually decreases, and the foaming ratio gradually increases. Thus, it can be known that in addition to generating gas, the modified p-toluenesulfonyl hydrazide microcapsules and their decomposition products can also act as nucleation sites for cell formation. During the foaming process, gas needs to accumulate and grow at specific sites to form a stable cell structure, making it easier for gas to form a large number of tiny and uniformly distributed gas nuclei at these sites, and then grow into fine and uniform cells, which helps to increase the foaming ratio. Based on the same mass of polyurethane material, due to the increase in the number of cells and the increase in volume, the overall density of the material decreases; the microcapsules can reduce the friction between materials, making the entire system flow more easily during processing such as stirring and molding, which is beneficial to the uniform dispersion of gas in the system and the uniform growth of cells. This good fluidity helps the gas generated by the decomposition of the foaming agent to better fill the polyurethane matrix, forming a more regular and uniform cell structure, thereby increasing the foaming ratio and also causing the material density to decrease.

[0130] By comparing Example 3 with Comparative Example 1, it can be seen that when preparing a lightweight polyurethane shoe material for sports shoes directly using p-toluenesulfonyl hydrazide without using modified p-toluenesulfonyl hydrazide microcapsules, the density of the polyurethane shoe material increases significantly, and the foaming ratio decreases significantly.

[0131] Taking Example 3 as the optimal example and combining it with Comparative Example 2, it can be known that in the preparation process of modified p-toluenesulfonyl hydrazide microcapsules, when fatty acids are removed, the density of the polyurethane shoe material increases significantly, and the foaming ratio decreases significantly;

[0132] Fatty acids can reduce the surface tension of the system during the foaming process, which helps to provide more nucleation sites for the formation of bubbles, making it easier for gas to form tiny gas nuclei in the system, and making the bubbles generated during the foaming process finer and more uniform. Once fatty acids are removed, the ability of the system to generate gas nuclei decreases, and it is difficult for gas to form a sufficient number of small gas nuclei. More gas may aggregate to form larger bubbles or fail to effectively nucleate to form cells, resulting in a small number of final cells and uneven sizes, and the foaming ratio also decreases significantly. Due to fewer cells and relatively smaller volume, the material density increases; fatty acids can also adsorb on the surface of bubbles to play a role in stabilizing the bubbles. Without fatty acids, the stability of the generated bubbles becomes worse, and they are prone to rupture or merge into larger bubbles during the growth process, making the gas that could originally form a fine cell structure unable to effectively remain in the system to form stable cells, further leading to a decrease in the foaming ratio and an increase in the material density.

[0133] Example 3 is taken as the optimal example. Combining with Comparative Example 3, it can be seen that when the nucleating agent is removed, the density of the polyurethane shoe material increases significantly, and the foaming ratio decreases significantly.

[0134] During the foaming of polyurethane, the blowing agent decomposes to generate gas, and these gases need to aggregate and grow at specific sites to form a stable cell structure. The nucleating agent can form many tiny positions that are conducive to gas aggregation in the system through its own physical or chemical properties, enabling the gas to be evenly dispersed and form a large number of fine gas nuclei. When the nucleating agent is removed, there are not enough nucleation sites in the system, and it is difficult for the gas to find a suitable starting point to form small and uniform bubbles, resulting in difficult bubble generation and ultimately a significant reduction in the number of cells formed, leading to a decrease in the foaming ratio. The nucleating agent can promote the uniform distribution of cells throughout the polyurethane matrix, ensuring a relatively consistent foaming situation in each part. However, after removing the nucleating agent, the cells are prone to be generated concentrated in some local areas, causing uneven distribution of cells inside the entire shoe material, further affecting the overall foaming effect of the material and significantly increasing its density.

[0135] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only the preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A lightweight polyurethane shoe material for sports shoes, characterized in that: The invention comprises the following components: 40-60 parts by weight of polyether polyol, 20-40 parts by weight of hexamethylene diisocyanate, 0.5-1.5 parts by weight of N,N-dimethylcyclohexylamine, 5-15 parts by weight of modified p-toluenesulfonyl hydrazide microcapsules, 1-3 parts by weight of nucleating agent, 0.5-2 parts by weight of zinc dialkyl dithiophosphate, 0.5-2 parts by weight of phenyl salicylate and 0.5-2 parts by weight of polyoxyethylene sorbitan monooleate; The modified p-toluenesulfonyl hydrazide microcapsules are prepared by aryl halide arylating p-toluenesulfonyl hydrazide and then microencapsulating it.

2. The lightweight polyurethane shoe material for sports shoes according to claim 1, characterized in that: The preparation process of the modified p-toluenesulfonyl hydrazide microcapsules is as follows: S1.

1. Weigh the following components in parts by weight respectively: 10-20 parts by weight of toluenesulfonyl hydrazide, 20-30 parts by weight of acetonitrile, 10-30 parts by weight of aryl halide, 1-5 parts by weight of boron trifluoride ether complex, 20-30 parts by weight of ethanol, 5-15 parts by weight of fatty acid, 10-20 parts by weight of polyvinyl alcohol and 1-5 parts by weight of glutaraldehyde; S1.2, dissolve p-toluenesulfonyl hydrazide in acetonitrile, stir at a speed of 300-500rpm for 10-20min, slowly add aryl halide, stir at a speed of 200-300rpm for 15-30min; then add boron trifluoride ether complex, under nitrogen protection, raise the temperature to 80-100℃, and stir at a speed of 200-300rpm for 12-24h; after the reaction is completed, allow the reaction mixture to cool naturally to room temperature, filter, rinse with hexane, and then dry at 50-60℃ for 6-8h to obtain arylated p-toluenesulfonyl hydrazide; S1.3, dissolving the arylated p-toluenesulfonyl hydrazide in ethanol, stirring at 300-400 rpm for 15-30 min at room temperature, adding fatty acid, stirring at 400-600 rpm for 6-12 h at 30-50 ° C; after the reaction is completed, allowing the reaction mixture to cool to room temperature naturally, filtering to separate the solid product, washing with ethanol, and then drying at 50-60 ° C for 10-12 h to obtain modified p-toluenesulfonyl hydrazide containing fatty acid; S1.4, dispersing the modified p-toluenesulfonyl hydrazide containing fatty acids in deionized water, stirring at a speed of 300-500 rpm for 10-20 min to form a stable suspension; dissolving polyvinyl alcohol in deionized water, heating to 80-90°C and stirring at a speed of 200-300 rpm until completely dissolved, to obtain a polyvinyl alcohol solution with a concentration of 5-10%; S1.

5. Use a high-speed shearing device with a rotation speed of 10000-20000 rpm and a shearing time of 15-30 min to add the suspension into a polyvinyl alcohol solution to form a fine oil-in-water emulsion, add glutaraldehyde into the emulsion to form microcapsules; then filter and separate the microcapsules, rinse them with deionized water for 3-5 times, and dry the microcapsules at 30-50° C. for 12-24 h to obtain modified p-toluenesulfonyl hydrazide microcapsules.

3. The lightweight polyurethane shoe material for sports shoes according to claim 2, characterized in that: In the above S1.2, the aryl halide is slowly added at a rate of 1-2 parts by weight per minute.

4. The lightweight polyurethane shoe material for sports shoes according to claim 2, characterized in that: In S1.3, the fatty acid is either stearic acid or palmitic acid.

5. The lightweight polyurethane shoe material for sports shoes according to claim 2, characterized in that: In the above S1.5, the thickness of the formed microcapsules is 1-5 μm.

6. A process for preparing a lightweight polyurethane shoe material for sports shoes, used for preparing a lightweight polyurethane shoe material for sports shoes as claimed in any one of claims 1 to 5, characterized in that: The preparation process of the lightweight polyurethane shoe material for sports shoes is as follows: S2.

1. Weigh the following components in parts by weight respectively: 40-60 parts by weight of polyether polyol, 20-40 parts by weight of hexamethylene diisocyanate, 0.5-1.5 parts by weight of N,N-dimethylcyclohexylamine, 5-15 parts by weight of modified p-toluenesulfonyl hydrazide microcapsules, 1-3 parts by weight of nucleating agent, 0.5-2 parts by weight of zinc dialkyl dithiophosphate, 0.5-2 parts by weight of phenyl salicylate and 0.5-2 parts by weight of polyoxyethylene sorbitan monooleate; S2.2, add nucleating agent, zinc dialkyl dithiophosphate and phenyl salicylate to polyether polyol in sequence, stir at 300-500 rpm for 10-20 min at room temperature to ensure uniform dispersion of the components; slowly add polyoxyethylene sorbitan monooleate, continue stirring at 300-500 rpm for 5-10 min; under nitrogen protection, add N,N-dimethylcyclohexylamine, and stir at 200-300 rpm for 5-10 min to form a uniform polyol mixture; S2.3, add hexamethylene diisocyanate to the polyol mixture, raise the temperature to 70-80°C, and continue stirring at a speed of 1000-2000 rpm for 3-5 minutes to ensure that the two phases are fully mixed; add modified p-toluenesulfonyl hydrazide microcapsules, and stir to ensure that they are evenly dispersed in the mixture; S2.4, pour the mixture in S2.3 into a mold, and place the mold in an oven to allow the material to fully foam and solidify; after foaming, naturally cool to room temperature to obtain a lightweight polyurethane shoe material for sports shoes.

7. The process for preparing the lightweight polyurethane shoe material for sports shoes according to claim 6, characterized in that: In the above S2.2, the nucleating agent is either zinc stearate or calcium stearate.

8. The process for preparing the lightweight polyurethane shoe material for sports shoes according to claim 6, characterized in that: In the above S2.2, the rate of adding polyoxyethylene sorbitan monooleate is 0.5-1 parts by weight per minute.

9. The process for preparing the lightweight polyurethane shoe material for sports shoes according to claim 6, characterized in that: In the step S2.3, the stirring speed for adding the microcapsules is 500-1000 rpm, and the stirring time is 15-20 min.

10. The process for preparing a lightweight polyurethane shoe material for sports shoes according to claim 6, characterized in that: In S2.4, the curing temperature is 80-100° C. and the curing time is 10-30 min.

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