Supercritical foaming insole material with high rebound response speed and preparation method thereof

Abstract

The invention provides a supercritical foaming insole material with high rebound response speed and a preparation method thereof, and belongs to the field of footwear products. The supercritical foaming insole material is formed by supercritical foaming of formula raw materials, and the formula raw materials comprise the following components in percentage by mass: more than 98% of polycaprolactone polyurethane; 0.1 to 0.3% of an anti-hydrolysis agent; 0.1 to 0.5% of an ultraviolet light absorber; and 0.1 to 0.5 percent of an antioxidant. The light weight of the insole material is guaranteed, and meanwhile the extreme rebound efficiency and the rapid deformation recovery capacity are achieved, so that the ground counter-acting force in the movement process is effectively buffered, potential injuries of movement impact to feet and joints are reduced, and unprecedented comfort and protection experience are brought to sports enthusiasts.

Description

Technical Field

[0001] The invention belongs to the field of footwear products, and in particular relates to a supercritical foaming midsole material with high rebound response speed and a preparation method thereof. Background Art

[0002] In the rapidly developing field of modern sports, the performance of sports equipment has a crucial impact on the performance of athletes and the experience of ordinary sports enthusiasts. For footwear products, traditional sports equipment materials such as EVA (ethylene-vinyl acetate copolymer) have met the basic comfort and durability requirements to a certain extent, but there are still significant deficiencies in rebound speed, response sensitivity and lightweight. With the continuous advancement of technology and the increasing quality requirements of consumers, the development of sports equipment sole materials with higher performance has become an urgent need in the industry.

[0003] As a cutting-edge material processing method, supercritical physical foaming technology has attracted widespread attention in the fields of sports equipment materials in recent years. This technology uses the unique properties of supercritical fluids (such as high solubility and low viscosity) to form a uniform and fine microporous structure inside the material, thereby giving footwear materials products excellent properties such as light weight, high resilience, sound insulation, heat insulation and shock absorption. Compared with traditional chemical foaming technology, supercritical physical foaming technology is more environmentally friendly and efficient, and can better control the pore structure and improve the overall performance of the material.

[0004] A Chinese patent document with publication number CN 112120351 A discloses a production method for integrally forming footwear, wherein the production method allows the gas in a supercritical state to saturate the thermoplastic elastomer particles, then releases the pressure to form a foamed midsole component while bonding the various footwear components, removing the shoe last, and obtaining a complete shoe. The production method involves supercritical physics technology and has high preparation efficiency, however, the rebound response speed of the foamed midsole component still needs to be further improved. Summary of the invention

[0005] In view of this, the present invention provides a supercritical foaming midsole material with a high rebound response speed and a preparation method thereof. The present invention strives to achieve extreme rebound efficiency and rapid deformation recovery ability while ensuring the lightweight of the midsole material, thereby effectively buffering the ground reaction force during exercise, reducing the potential damage to the feet and joints caused by sports impact, and bringing unprecedented comfort and protection experience to sports enthusiasts.

[0006] The present invention provides a supercritical foaming midsole material with high rebound response speed. The supercritical foaming midsole material is formed by supercritical foaming of formula raw materials. The formula raw materials include the following components in mass fractions:

[0007] More than 98% polycaprolactone type polyurethane;

[0008] 0.1-0.3% anti-hydrolysis agent;

[0009] 0.1-0.5% UV absorber;

[0010] 0.1-0.5% antioxidant.

[0011] In an embodiment of the present invention, the synthetic monomers of the polycaprolactone polyurethane include: 63-64wt% of polycaprolactone diol, 23-24wt% of HDI, 9-10wt% of butanediol and 3-4wt% of neopentyl glycol.

[0012] In an embodiment of the present invention, the anti-hydrolysis agent is a polycarbodiimide anti-hydrolysis agent, and the mass fraction of the anti-hydrolysis agent is 0.1-0.2%.

[0013] In an embodiment of the present invention, the ultraviolet absorber is N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxalamide, and the mass fraction of the ultraviolet absorber is 0.2-0.3%.

[0014] In an embodiment of the present invention, the antioxidant is antioxidant XH-245, and the mass fraction of the antioxidant is 0.2-0.3%.

[0015] In an embodiment of the present invention, the compression deformation recovery speed of the supercritical foaming midsole material is 750-770 mm / s.

[0016] In an embodiment of the present invention, the hardness of the supercritical foaming midsole material is 36-42C.

[0017] The present invention provides a method for preparing the supercritical foaming midsole material as described above, comprising the following steps:

[0018] Using a supercritical fluid as a foaming agent, dissolving the foaming agent in a formula raw material under a supercritical state, and then inducing expansion through a decompression process to obtain the supercritical foaming midsole material;

[0019] The formula raw materials include the following components by mass fraction:

[0020] More than 98% polycaprolactone type polyurethane;

[0021] 0.1-0.3% anti-hydrolysis agent;

[0022] 0.1-0.5% UV absorber;

[0023] 0.1-0.5% antioxidant.

[0024] In an embodiment of the present invention, the supercritical fluid is carbon dioxide or nitrogen.

[0025] With the continuous progress in the field of materials science, it also provides strong support for the research and development of high-performance sports equipment materials. The present invention has pioneered the development of a high-performance supercritical foaming midsole material by integrating advanced materials science and supercritical physical foaming technology. The formula raw materials of the supercritical foaming midsole material include: more than 98wt% polycaprolactone polyurethane; 0.1-0.3wt% anti-hydrolysis agent; 0.1-0.5wt% ultraviolet absorber; 0.1-0.5% antioxidant. First, the present invention adopts a special formula and supercritical physical foaming technology, so that the material can quickly and fully absorb energy when subjected to external force, and restore deformation in a very short time. This instant rebound performance greatly enhances the wearer's sports experience and reduces fatigue during exercise. Secondly, the midsole material of the present invention has an extremely fast response speed, and the rebound process can start almost at the same time as it is impacted. This rapid response ability helps to more effectively disperse and alleviate sports impact, thereby protecting the wearer's feet and joints and reducing the risk of sports injuries. Finally, the high rebound response speed characteristic of the midsole material of the present invention also enables it to maintain stable performance after repeated use, and is not prone to aging or performance degradation, thereby ensuring the long-term durability of the midsole material. In summary, the midsole material with high rebound response speed characteristics of the present invention provides a solution for higher performance products in the relevant field. DETAILED DESCRIPTION

[0026] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the technical scheme of the present invention is now described in detail below in conjunction with specific embodiments. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0027] The present invention provides a supercritical foaming midsole material with high rebound response speed, which is formed by supercritical foaming of formula raw materials, wherein the formula raw materials include the following components in mass fractions:

[0028] More than 98% polycaprolactone type polyurethane;

[0029] 0.1-0.3% anti-hydrolysis agent;

[0030] 0.1-0.5% UV absorber;

[0031] 0.1-0.5% antioxidant.

[0032] The midsole material described in the present invention is a new type of supercritical foaming midsole material that combines high rebound, extremely fast response and durability. It can solve the deficiencies of traditional sports equipment materials in rebound speed, response sensitivity and long-term durability, so as to significantly improve the wearing comfort and protective performance of sports equipment such as sports shoes.

[0033] The midsole material described in the present invention is a foamed material formed by supercritical foaming of formulated raw materials, wherein the formulated raw materials contain polycaprolactone polyurethane as a main component, and its mass content exceeds 98%, preferably greater than or equal to 99%, and further 99.1-99.7%, for example, 99.2%, 99.3%, 99.4%, 99.5%, etc.

[0034] Polyurethane is the abbreviation of polyurethane resin, abbreviated as PU in English. Its synthesis is mainly carried out through the reaction of isocyanate and polyol. Among them, cast polyurethane elastomer is referred to as CPU and is widely used; thermoplastic polyurethane elastomer is referred to as TPU. In the unique raw material formula design of the embodiment of the present invention, polycaprolactone polyurethane, a polyester thermoplastic polyurethane elastomer, is used as the basic material, and special additives such as anti-hydrolysis agent and antioxidant are added through scientific proportions to form a unique composite system. This formula can optimize the physical properties and chemical stability of the midsole material, ensure the effective arrangement and cross-linking of molecular chains during the supercritical foaming process, and lay the foundation for the excellent rebound performance of the material.

[0035] Preferably, the synthetic monomers of the polycaprolactone polyurethane include: 63-64wt% polycaprolactone diol, 23-24wt% HDI, 9-10wt% butanediol and 3-4wt% neopentyl glycol. Further, its synthetic monomers are: 63.8% polycaprolactone diol, 23.5% HDI, 9.2% butanediol and 3.5% neopentyl glycol. Among them, HDI is the abbreviation of hexamethylene diisocyanate, which is an aliphatic isocyanate, which is conducive to obtaining a polyurethane elastomer with good weather resistance and flexibility. The polycaprolactone polyurethane can be a commercially available product, such as the H793 model of Guangzhou Shunli Company, with a melt index of 5-10g / 10min (test conditions 190℃, 2.16kg weight).

[0036] In an embodiment of the present invention, the formula raw materials include 0.1-0.3% by mass of an anti-hydrolysis agent, and its mass fraction is preferably 0.1-0.2%. The anti-hydrolysis agent is preferably a polycarbodiimide anti-hydrolysis agent, and its specific melting point can be 70-90°C, and its density is about 1.05g / cm 3 , solid content ≥99%, commercially available products can be used.

[0037] In addition, the raw material formula includes the following components by mass fraction: 0.1-0.5% of ultraviolet absorber and 0.1-0.5% of antioxidant. The ultraviolet absorber is preferably N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxalamide, which is also called ultraviolet absorber UV-312, and its chemical structure is shown in the following formula; the mass fraction of the ultraviolet absorber is preferably 0.2-0.3%, and it has the characteristics of good thermal stability and the like.

[0038]

[0039] In a preferred embodiment of the present invention, the antioxidant is antioxidant XH-245, and the mass fraction of the antioxidant is 0.2-0.3%. The chemical name of antioxidant XH-245 is triethylene glycol ether-di(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, which is mainly used to extend the life of polymer materials and inhibit or delay the oxidative degradation of materials. The embodiment of the present invention finely controls the molecular chain structure of the midsole material, optimizes the molecular structure, etc., to ensure that the molecular chain can maintain an appropriate balance of flexibility and rigidity during the foaming process. This optimization not only improves the rebound speed and response sensitivity of the material, but also significantly enhances the material's fatigue resistance and stability under long-term use.

[0040] The embodiments of the present invention can precisely control the molecular structure and physical properties of the midsole material through the above-mentioned scientific ratio of high molecular polymers and special additives to achieve the optimization of material performance. This refined regulation not only helps to improve the rebound speed and response sensitivity of the midsole material, but also significantly enhances the durability of the material and extends the service life of sports equipment. In the embodiments of the present invention, the supercritical foaming midsole material with a high rebound response speed can not only effectively improve the wearing comfort and protective performance of sports equipment such as sports shoes, but also bring revolutionary innovative solutions to the sporting goods industry and promote the sustainable development of the entire industry.

[0041] The embodiment of the present invention provides a method for preparing the supercritical foaming midsole material as described above, comprising the following steps:

[0042] A supercritical fluid (such as carbon dioxide or nitrogen) is used as a foaming agent, which is dissolved in the above-mentioned formula raw materials under a supercritical state, and then expanded by a decompression process to obtain the supercritical foaming midsole material.

[0043] The components in the raw material formula are as described above; in the embodiment of the present invention, the raw materials are placed in a supercritical foaming processing device, and a foaming agent such as carbon dioxide or nitrogen is dissolved in the material under a supercritical state. The process conditions for dissolving the supercritical fluid foaming agent include: a pressure of 40-50MPa, a temperature of 130-160°C, and a time of 60-150min.

[0044] Subsequently, the embodiment of the present invention induces expansion through a decompression process to obtain the supercritical foaming midsole material. The embodiment of the present invention prepares a new type of supercritical foaming midsole material with high rebound response speed by precisely controlling the material molecular structure and supercritical material foaming process technology. The supercritical foaming midsole material has excellent instant rebound performance, fast response speed, and can recover deformation in a very short time, significantly improving the wearer's sports experience and comfort.

[0045] In some embodiments of the present invention, the compression deformation recovery rate of the supercritical foaming midsole material is 750-770mm / s. In addition, the hardness of the supercritical foaming midsole material can be 36-42C (normal temperature test). The present invention successfully develops a new type of supercritical foaming midsole material through the organic combination of unique formula raw materials and supercritical physical foaming technology. It has significant characteristics of high rebound response speed, excellent resilience and durability, and brings revolutionary innovative solutions to the sporting goods industry, with huge market potential and application prospects.

[0046] In order to further understand the present invention, the present invention is described in detail below in conjunction with the examples, and the protection scope of the present invention is not limited by the following examples. In addition, the experimental methods without specifying the specific experimental conditions are conventional methods and conditions well known in the art.

[0047] The synthetic monomers of the polycaprolactone polyurethane include: 63.8wt% (molar ratio of 7.3%) of polycaprolactone diol, 23.5wt% of HDI (molar ratio of 50.0%), 9.2wt% of butanediol (molar ratio of 30.6%) and 3.5wt% (molar ratio of 12.1%) of neopentyl glycol; it is model H793 of Guangzhou Shunli Company, with a melt index of 5-10g / 10min (test conditions 190°C, 2.16kg weight).

[0048] Example 1

[0049] The method for preparing the supercritical foaming midsole material comprises the following steps:

[0050] Supercritical fluid is used as a foaming agent, and the foaming agent carbon dioxide is dissolved in the formula raw materials under a supercritical state, and then expansion is induced through a decompression process to obtain the supercritical foaming midsole material; the process conditions for dissolving the supercritical fluid foaming agent include: pressure of 40-50MPa, temperature of 140-150°C, and time of 120min.

[0051] The formula raw materials include the following components by mass fraction:

[0052] 99.4% polycaprolactone type polyurethane;

[0053] 0.2% anti-hydrolysis agent;

[0054] 0.2% UV absorber;

[0055] 0.2% antioxidant.

[0056] The anti-hydrolysis agent is a polycarbodiimide anti-hydrolysis agent with a melting point of 70-90°C and a density of about 1.05 g / cm 3 , solid content ≥99%.

[0057] The ultraviolet absorber is N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxalamide; and the antioxidant is antioxidant XH-245.

[0058] The supercritical foamed midsole sample of Example 1 was subjected to performance testing, and the results are as follows.

[0059] Table 1 Performance test results of the midsole samples of Example 1

[0060]

[0061]

[0062] Wear resistance test: GB / T 3903.2-2017 peeling. Various impact shock absorption tests: J4003; Rebound and shock absorption performance test: J4004; Fatigue compression performance test: J4011 1.3KN, 3.8Hz, 100,000 times. Color fastness test: J52, B method is UV lamp, continuous irradiation for 3h, C method is spotlight, irradiation distance 0.5m, continuous irradiation for 72h. Aging resistance test: J53 A method, 70℃, 95%RH, 72h. Hardness test: J56 Aska C; There is also a low temperature (0~15℃, 2h) pretreatment and immediate test, low temperature hardness left and right (MD up, MD down): 41~47. Strength test: J57 C method; Compression deformation test: J59 A method 50℃, 6h. Density test: J60 A method; Shrinkage performance test: J64 B method 70℃, 20min. Delamination tear strength test: J83; Resilience test: J86.

[0063] In addition, the sole samples are tested in pairs of left and right feet; there are also MD upper and lower two-layer structures.

[0064] Table 2 Comparative research data on the rebound response speed of supercritical foaming midsole materials

[0065]

[0066] The national standard method code is GB / T30907. Test 30 times and take the average value of the last 5 test data.

[0067] Example 2

[0068] Similar to Example 1, the method for preparing the supercritical foaming midsole material comprises the following steps:

[0069] Using supercritical fluid as a foaming agent, dissolving the foaming agent carbon dioxide in the formula raw materials under a supercritical state, and then inducing expansion through a decompression process to obtain the supercritical foaming midsole material;

[0070] The formula raw materials include the following components by mass fraction:

[0071] 99.3% polycaprolactone type polyurethane;

[0072] 0.1% anti-hydrolysis agent;

[0073] 0.3% UV absorber;

[0074] 0.3% antioxidant.

[0075] From the above examples, it can be seen that the supercritical foaming midsole material prepared in the embodiments of the present invention has a wide range of application prospects in the fields of sports shoes, etc., and can effectively reduce sports impact and protect feet and joints. The embodiments of the present invention achieve a perfect combination of its rebound performance and durability by optimizing the molecular structure and foaming process of the midsole material, and provide a high-performance material solution for related fields.

[0076] The above examples are only used to illustrate the technical features and implementation process of the present invention, rather than to limit the technical solution of the present invention. It should be pointed out that for ordinary technicians in this field, the present invention can still be modified or replaced by equivalents, and modifications or replacements that do not deviate from the principles of the present invention are all covered by the protection of the present invention.

Claims

1. A supercritical foaming midsole material with high rebound response speed, characterized in that: The supercritical foaming midsole material is formed by supercritical foaming of a formula raw material, and the formula raw material includes the following components in mass fractions: More than 98% polycaprolactone type polyurethane; 0.1-0.3% anti-hydrolysis agent; 0.1-0.5% UV absorber; 0.1-0.5% antioxidant.

2. The supercritical foaming midsole material according to claim 1, characterized in that: The synthetic monomers of the polycaprolactone polyurethane include: 63-64wt% of polycaprolactone diol, 23-24wt% of HDI, 9-10wt% of butanediol and 3-4wt% of neopentyl glycol.

3. The supercritical foaming midsole material according to claim 1, characterized in that: The anti-hydrolysis agent is a polycarbodiimide anti-hydrolysis agent, and the mass fraction of the anti-hydrolysis agent is 0.1-0.2%.

4. The supercritical foaming midsole material according to claim 1, characterized in that: The ultraviolet absorber is N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxalamide, and the mass fraction of the ultraviolet absorber is 0.2-0.3%.

5. The supercritical foaming midsole material according to claim 1, characterized in that: The antioxidant is antioxidant XH-245, and the mass fraction of the antioxidant is 0.2-0.3%.

6. The supercritical foaming midsole material according to any one of claims 1 to 5, characterized in that: The compression deformation recovery speed of the supercritical foaming midsole material is 750-770 mm / s.

7. The supercritical foaming midsole material according to claim 6, characterized in that: The hardness of the supercritical foaming midsole material is 36-42C.

8. The method for preparing the supercritical foaming midsole material according to any one of claims 1 to 7, comprising the following steps: Using a supercritical fluid as a foaming agent, dissolving the foaming agent in a formula raw material under a supercritical state, and then inducing expansion through a decompression process to obtain the supercritical foaming midsole material; The formula raw materials include the following components by mass fraction: More than 98% polycaprolactone type polyurethane; 0.1-0.3% anti-hydrolysis agent; 0.1-0.5% UV absorber; 0.1-0.5% antioxidant.

9. The preparation method according to claim 8, characterized in that: The supercritical fluid is carbon dioxide or nitrogen.

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