A caprolactone copolymer foam material, its preparation method, and a shoe sole.

Abstract

This invention discloses a caprolactone copolymer foam material, its preparation method, and a shoe sole. The caprolactone copolymer foam material is prepared by supercritical foaming of the following components in parts by weight: 90-95 parts thermoplastic polyurethane; 1-3 parts antioxidant; 0.1-0.5 parts plasticizer; 0.5-2 parts ultraviolet absorber; 1-4 parts anti-hydrolysis agent; and 2-5 parts filler. The thermoplastic polyurethane is composed of the following components in parts by weight: 5-10 parts butanediol; 8-15 parts oxalic acid dihydrate; 2-5 parts caprolactone; 6-10 parts hexamethylene diisocyanate; and 1-3 parts neopentyl glycol. This material exhibits sufficiently light weight and excellent support and cushioning properties.

Description

Technical Field

[0001] This invention relates to the field of copolymer foaming materials technology, specifically to a caprolactone copolymer foaming material, its preparation method, and a shoe sole. Background Technology

[0002] In racing, shoes place high demands on performance: they must be sufficiently lightweight while providing excellent support and cushioning. Only shoes with these properties can ensure optimal performance during high-speed running. Current racing shoe soles are generally made using supercritical foaming technology to produce foamed materials from raw materials, typically EVA. While EVA is lightweight, it often struggles to maintain other key performance characteristics. Summary of the Invention

[0003] The purpose of this invention is to overcome the aforementioned defects or problems in the prior art and to provide a caprolactone copolymer foam material, a preparation method, and a shoe sole, which has a sufficiently light weight and excellent support and cushioning performance.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] Technical Solution 1: A caprolactone copolymer foam material, which is made by supercritical foaming of the following components in parts by weight: 90-95 parts thermoplastic polyurethane; 1-3 parts antioxidant; 0.1-0.5 parts plasticizer; 0.5-2 parts ultraviolet absorber; 1-4 parts anti-hydrolysis agent; 2-5 parts filler; wherein the thermoplastic polyurethane is made by the following components in parts by weight: 5-10 parts butanediol; 8-15 parts oxalic acid dihydrate; 2-5 parts caprolactone; 6-10 parts hexamethylene diisocyanate; 1-3 parts neopentyl glycol.

[0006] Technical Solution 2 based on Technical Solution 1: The antioxidant comprises the following components in parts by weight: 0.05-0.10 parts of 2,6-di-tert-butyl-p-cresol; 0.6-2.0 parts of triethylene glycol ether-di(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate; and 0.35-0.90 parts of dodecyl thiodipropionate.

[0007] Technical Solution 3 based on Technical Solution 2: The plasticizer is triphenyl phosphate.

[0008] Technical solution four based on technical solution three: The ultraviolet absorber is N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-β-ethylenediamide.

[0009] Technical solution five based on technical solution four: The anti-hydrolysis agent is polycarbodiimide.

[0010] Technical solution six based on technical solution five: The filler is silicon dioxide.

[0011] Furthermore, the present invention also provides a seventh technical solution: a method for preparing a caprolactone copolymer foam material, which is based on the components of the caprolactone copolymer foam material described in any one of technical solutions one to six, and is prepared by the following steps: Step one: obtaining thermoplastic polyurethane by bulk polymerization according to the corresponding components of thermoplastic polyurethane; Step two: mixing the thermoplastic polyurethane obtained in step one with other components to obtain a compound material; Step three: injecting the compound material into a mold and foaming it by supercritical foaming; Step four: after foaming, cooling and demolding to obtain the caprolactone copolymer foam material.

[0012] Technical solution eight based on technical solution seven: In step three, the supercritical foaming conditions are: the volume ratio of nitrogen to carbon dioxide is 75%-80% to 20%-25%; the pressure during the pressurization stage is 12-14MPa, the temperature is 175-185℃, and the pressure holding time is 90-110min.

[0013] In addition, the present invention also provides a ninth technical solution: a shoe sole, characterized in that it is made of caprolactone copolymer foam material prepared by the method of preparing caprolactone copolymer foam material as described in technical solutions seven or eight.

[0014] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects:

[0015] The caprolactone copolymer foam material provided by this invention uses an innovatively developed thermoplastic polyurethane as the main substrate. The main components of this thermoplastic polyurethane include butanediol, oxalic acid dihydrate, caprolactone, hexamethylene diisocyanate, and neopentyl glycol. Butanediol, as the soft segment component, provides flexibility and low-temperature resistance, while oxalic acid dihydrate, as the hard segment component, enhances the material's rigidity and wear resistance. Combined with a specific component ratio, the resulting thermoplastic polyurethane achieves a balance between soft and hard segments, ensuring that the thermoplastic polyurethane possesses both good elasticity and sufficient structural strength. Simultaneously, caprolactone and neopentyl glycol, as chain extenders, increase the molecular weight of the thermoplastic polyurethane, improving the material's strength and stability. Hexamethylene diisocyanate... Isocyanate, as a crosslinking agent, promotes intermolecular crosslinking, enhancing the strength and elasticity of the material. Through the synergistic effect of the above components, the thermoplastic polyurethane possesses both low density and good support and shock absorption properties. Subsequently, using this thermoplastic polyurethane as a substrate, the aforementioned caprolactone copolymer foam material is prepared through supercritical foaming. Supercritical foaming allows the copolymer foam material to form uniform and dense pores. Combined with the inherent material properties of thermoplastic polyurethane, this achieves a significant reduction in weight. At the same time, the pore structure of the copolymer foam material enables it to effectively disperse impact forces while reducing weight, providing better support and shock absorption properties.

[0016] Furthermore, triphenyl phosphate is used as a plasticizer in this caprolactone copolymer foam material. It not only improves the material's resilience and shock absorption properties but also helps disperse the silica filler in the polymer matrix, thereby improving the overall uniformity of the material's properties. The silica filler enhances the mechanical properties of this copolymer foam material, giving it good support and shock absorption performance, and it can also act as a UV shielding agent, providing protection for the material. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are preferred embodiments of the present invention and should not be considered as excluding other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] In the claims and description of this invention, the terms "comprising," "having," and variations thereof are used to mean "including but not limited to."

[0019] This invention provides a shoe sole made of caprolactone copolymer foam material, which is produced by supercritical foaming of the following components in parts by weight: 90-95 parts thermoplastic polyurethane; 1-3 parts antioxidant; 0.1-0.5 parts plasticizer; 0.5-2 parts ultraviolet absorber; 1-4 parts anti-hydrolysis agent; and 2-5 parts filler. The thermoplastic polyurethane is composed of the following components in parts by weight: 5-10 parts butanediol; 8-15 parts oxalic acid dihydrate; 2-5 parts caprolactone; 6-10 parts hexamethylene diisocyanate; and 1-3 parts neopentyl glycol.

[0020] The antioxidant comprises the following components in parts by weight: 0.05-0.10 parts of 2,6-di-tert-butyl-p-cresol; 0.6-2.0 parts of triethylene glycol ether-di(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate; and 0.35-0.90 parts of dodecyl thiodipropionate. This antioxidant consists of three different components. 2,6-Di-tert-butyl-p-cresol is a phenolic antioxidant with a benzene ring structure containing two tert-butyl groups and one hydroxyl group. It prevents oxidative degradation of materials by capturing free radicals, effectively preventing materials from becoming brittle, yellowing, or losing elasticity due to oxidation. Triethylene glycol ether-di(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate is an ester antioxidant with a long alkyl chain, ether bond, and benzene ring structure. It exhibits excellent thermal stability, improving the material's stability at high temperatures and providing better protection under high-temperature processing or use conditions. Didodecyl thiodipropionate is a thioester antioxidant containing sulfur atoms and a long alkyl chain. It has metal ion passivation properties, preventing metal-catalyzed oxidation reactions. By incorporating these three different types of antioxidants into the formulation, the material can maintain its performance and appearance under various usage conditions. This combined strategy helps improve the overall durability and reliability of the material, especially in outdoor applications or situations requiring long-term exposure to harsh environments.

[0021] The plasticizer is triphenyl phosphate. In this formulation, triphenyl phosphate increases the flexibility and ductility of the polymer material. By reducing the interaction forces between polymer molecular chains, it makes the material softer and easier to process. It can provide better resilience and shock absorption properties for the aforementioned caprolactone copolymer foam material. Simultaneously, triphenyl phosphate also helps disperse silica fillers in the polymer matrix, thereby improving the uniformity of the overall material properties.

[0022] The ultraviolet absorber is N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-β-ethylenediamide, which protects materials from ultraviolet damage. This compound absorbs ultraviolet radiation and converts it into low-energy heat, thereby preventing ultraviolet radiation from damaging the polymer structure and extending the material's service life.

[0023] The anti-hydrolysis agent is polycarbodiimide, whose main function is to improve the material's resistance to hydrolysis. Polycarbodiimide possesses extremely high chemical and thermal stability, effectively resisting hydrolytic reactions, especially in humid or high-humidity environments. This property makes polycarbodiimide an ideal choice for protecting materials from hydrolysis, thereby maintaining the material's mechanical properties and chemical stability, and extending its service life. By adding polycarbodiimide to the formulation, the durability and reliability of the material under various application conditions can be significantly improved.

[0024] The filler is silica, which enhances the mechanical properties of the copolymer foam material, giving it good support and shock absorption properties, and also acts as a UV shielding agent to protect the material.

[0025] In the components of thermoplastic polyurethane, butanediol, as the soft segment component, provides flexibility and low-temperature resistance, while oxalic acid dihydrate, as the hard segment component, enhances the material's rigidity and wear resistance. Combined with a specific component ratio, the resulting thermoplastic polyurethane achieves a balance between soft and hard segments, ensuring that it possesses both good elasticity and sufficient structural strength. Simultaneously, caprolactone and neopentyl glycol, as chain extenders, increase the molecular weight of the thermoplastic polyurethane, improving the material's strength and stability. Hexamethylene diisocyanate, as a crosslinking agent, promotes intermolecular crosslinking, enhancing the material's strength and elasticity. Through the synergistic effect of these components, the thermoplastic polyurethane achieves both low density and good support and shock absorption properties.

[0026] The above-mentioned caprolactone copolymer foam material is prepared based on the above components using the following steps:

[0027] Step 1: Obtain thermoplastic polyurethane by bulk polymerization according to the corresponding components of thermoplastic polyurethane;

[0028] Step 2: Mix the thermoplastic polyurethane obtained in Step 1 with other components to obtain a compound material;

[0029] Step 3: Inject the mixed material into the mold and foam it using supercritical foaming.

[0030] Step 4: After foaming is complete, cool and demold to obtain the caprolactone copolymer foam material.

[0031] The thermoplastic polyurethane is prepared by bulk polymerization, a conventional polymer polymerization method. Those skilled in the art can prepare thermoplastic polyurethane according to this polymerization method based on actual conditions. The thermoplastic polyurethane obtained in step one is mixed with other components using a mixing machine. The mixing temperature can be adjusted according to actual conditions, with a preferred mixing temperature of 150℃ to 160℃. In step three, the mixed material is injected into a mold using high-pressure injection, and then foamed using supercritical foaming. Supercritical foaming is a conventional physical foaming method in the art, and those skilled in the art are familiar with the specific process of supercritical foaming. Preferred supercritical foaming conditions are: a nitrogen to carbon dioxide volume ratio of 75%-80% to 20%-25%; a pressure of 12-14 MPa during the pressurization stage; a temperature of 175-185℃; and a holding time of 90-110 min.

[0032] The caprolactone copolymer foam material provided by this invention uses an innovatively developed thermoplastic polyurethane as the main substrate. The main components of this thermoplastic polyurethane include butanediol, oxalic acid dihydrate, caprolactone, hexamethylene diisocyanate, and neopentyl glycol. Butanediol, as the soft segment component, provides flexibility and low-temperature resistance, while oxalic acid dihydrate, as the hard segment component, enhances the material's rigidity and wear resistance. Combined with a specific component ratio, the resulting thermoplastic polyurethane achieves a balance between soft and hard segments, ensuring that the thermoplastic polyurethane possesses both good elasticity and sufficient structural strength. Simultaneously, caprolactone and neopentyl glycol, as chain extenders, increase the molecular weight of the thermoplastic polyurethane, improving the material's strength and stability. Hexamethylene diisocyanate... Isocyanate, as a crosslinking agent, promotes intermolecular crosslinking, enhancing the strength and elasticity of the material. Through the synergistic effect of the above components, the thermoplastic polyurethane possesses both low density and good support and shock absorption properties. Subsequently, using this thermoplastic polyurethane as a substrate, the aforementioned caprolactone copolymer foam material is prepared through supercritical foaming. Supercritical foaming allows the copolymer foam material to form uniform and dense pores. Combined with the inherent material properties of thermoplastic polyurethane, this achieves a significant reduction in weight. At the same time, the pore structure of the copolymer foam material enables it to effectively disperse impact forces while reducing weight, providing better support and shock absorption properties.

[0033] Furthermore, triphenyl phosphate is used as a plasticizer in this caprolactone copolymer foam material. It not only improves the material's resilience and shock absorption properties but also helps disperse the silica filler in the polymer matrix, thereby improving the overall uniformity of the material's properties. The silica filler enhances the mechanical properties of this copolymer foam material, giving it good support and shock absorption performance, and it can also act as a UV shielding agent, providing protection for the material.

[0034] To further illustrate the advantages of the caprolactone copolymer foam material provided by the present invention, the following examples are provided in this specification.

[0035] Example 1

[0036] Weigh the components according to the following mass fractions:

[0037]

[0038] The thermoplastic polyurethane includes: 5 parts butanediol; 8 parts oxalic acid dihydrate; 2 parts caprolactone; 6 parts hexamethylene diisocyanate; and 1 part neopentyl glycol.

[0039] The antioxidants include: 0.05 parts of 2,6-di-tert-butyl-p-cresol; 0.6 parts of triethylene glycol ether-di(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate; and 0.35 parts of dodecyl thiodipropionate.

[0040] The plasticizer is triphenyl phosphate; the ultraviolet absorber is N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-β-oxadiamide; the hydrolysis inhibitor is polycarbodiimide; and the filler is silica.

[0041] The above components were prepared into a caprolactone copolymer foam material according to the following steps:

[0042] Step 1: Obtain thermoplastic polyurethane by bulk polymerization according to the corresponding components of thermoplastic polyurethane; Step 2: Mix the thermoplastic polyurethane obtained in Step 1 with other components to obtain a compound material; Step 3: Inject the compound material into a mold and foam it through supercritical foaming; Step 4: After foaming, cool and demold to obtain the caprolactone copolymer foam material.

[0043] In step two, the mixing temperature is 150℃; in step three, the supercritical foaming conditions are: nitrogen to carbon dioxide volume ratio of 75% to 25%; the pressure during the pressurization stage is 12MPa, the temperature is 175℃, and the holding time is 90min.

[0044] Example 2

[0045] Weigh the components according to the following mass fractions:

[0046]

[0047] The thermoplastic polyurethane includes: 7.5 parts butanediol; 11.5 parts oxalic acid dihydrate; 3.5 parts caprolactone; 8 parts hexamethylene diisocyanate; and 2 parts neopentyl glycol.

[0048] The antioxidants include: 0.075 parts of 2,6-di-tert-butyl-p-cresol; 1.3 parts of triethylene glycol ether-di(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate; and 0.625 parts of dodecyl thiodipropionate.

[0049] The plasticizer is triphenyl phosphate; the ultraviolet absorber is N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-β-oxadiamide; the hydrolysis inhibitor is polycarbodiimide; and the filler is silica.

[0050] The above components were prepared into a caprolactone copolymer foam material according to the following steps:

[0051] Step 1: Obtain thermoplastic polyurethane by bulk polymerization according to the corresponding components of thermoplastic polyurethane; Step 2: Mix the thermoplastic polyurethane obtained in Step 1 with other components to obtain a compound material; Step 3: Inject the compound material into a mold and foam it through supercritical foaming; Step 4: After foaming, cool and demold to obtain the caprolactone copolymer foam material.

[0052] In step two, the mixing temperature is 155℃; in step three, the supercritical foaming conditions are: nitrogen to carbon dioxide volume ratio of 78% to 22%; the pressure during the pressurization stage is 13MPa, the temperature is 180℃, and the holding time is 100min.

[0053] Example 3

[0054] Weigh the components according to the following mass fractions:

[0055]

[0056] The thermoplastic polyurethane includes: 10 parts butanediol; 15 parts oxalic acid dihydrate; 5 parts caprolactone; 10 parts hexamethylene diisocyanate; and 3 parts neopentyl glycol.

[0057] The antioxidants include: 0.1 parts of 2,6-di-tert-butyl-p-cresol; 2 parts of triethylene glycol ether-di(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate; and 0.9 parts of dodecyl thiodipropionate.

[0058] The plasticizer is triphenyl phosphate; the ultraviolet absorber is N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-β-oxadiamide; the hydrolysis inhibitor is polycarbodiimide; and the filler is silica.

[0059] The above components were prepared into a caprolactone copolymer foam material according to the following steps:

[0060] Step 1: Obtain thermoplastic polyurethane by bulk polymerization according to the corresponding components of thermoplastic polyurethane; Step 2: Mix the thermoplastic polyurethane obtained in Step 1 with other components to obtain a compound material; Step 3: Inject the compound material into a mold and foam it through supercritical foaming; Step 4: After foaming, cool and demold to obtain the caprolactone copolymer foam material.

[0061] In step two, the mixing temperature is 160℃; in step three, the supercritical foaming conditions are: nitrogen to carbon dioxide volume ratio of 80% to 20%; the pressure during the pressurization stage is 14MPa, the temperature is 185℃, and the holding time is 110min.

[0062] In addition, the present invention specification provides the following comparative examples:

[0063] Comparative Example 1: Based on Example 2, the difference is that the mass fraction of caprolactone in the thermoplastic polyurethane is 0.5 parts and the mass fraction of neopentyl glycol is 0.5 parts.

[0064] Comparative Example 2: Based on Example 2, the difference is that the mass fraction of oxalic acid dihydrate in the thermoplastic polyurethane is 3 parts.

[0065] Comparative Example 3: Based on Example 2, except that it does not include triphenyl phosphate.

[0066] Performance tests were conducted on Examples 1, 2, and 3, and Comparative Examples 1, 2, and 3 as described above. The test results are as follows:

[0067]

[0068] The test results above show that the caprolactone copolymer foam materials provided in Examples 1, 2, and 3 of this invention achieve a good balance in terms of resilience, damping performance, and density. Comparative Example 1, due to the reduced proportion of caprolactone and neopentyl glycol, resulted in a decrease in the damping performance and resilience of the final foam material. This is because the thermoplastic polyurethane in Comparative Example 1 has a lower molecular weight, leading to poorer performance. Comparative Example 2, due to the reduced proportion of oxalic acid dihydrate, resulted in a decrease in the damping performance of the final foam material. This is because the ratio of soft and hard segments in the thermoplastic polyurethane in Comparative Example 2 is unbalanced, making it impossible to achieve a good balance between resilience and damping performance. Comparative Example 3, by not including triphenyl phosphate, resulted in a decrease in the damping performance and an increase in density of the final material. This is because the silica filler cannot be uniformly dispersed, and the agglomerated silica reduces the performance of the final material.

[0069] The foregoing description of the specifications and embodiments is intended to explain the scope of protection of this invention, but does not constitute a limitation on the scope of protection of this invention. Modifications, equivalent substitutions, or other improvements to the embodiments of this invention or a portion thereof that can be obtained by those skilled in the art through logical analysis, reasoning, or limited experimentation, based on the teachings of this invention or the foregoing embodiments, in conjunction with common knowledge, general technical knowledge, and / or existing technology, should all be included within the scope of protection of this invention.

Claims

1. A caprolactone copolymer foam material, characterized in that, It is made from the following components by weight using a supercritical foaming method: Thermoplastic polyurethane is composed of the following components in parts by weight:

2. The caprolactone copolymer foam material as described in claim 1, characterized in that, The antioxidant comprises the following components in parts by weight: 0.05-0.10 parts of 2,6-di-tert-butyl-p-cresol; 0.6-2.0 parts of triethylene glycol ether-di(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate; and 0.35-0.90 parts of dodecyl thiodipropionate.

3. The caprolactone copolymer foam material as described in claim 2, characterized in that, The plasticizer is triphenyl phosphate.

4. The caprolactone copolymer foam material as described in claim 3, characterized in that, The ultraviolet absorber is N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-β-ethylenediamide.

5. The caprolactone copolymer foam material as described in claim 4, characterized in that, The anti-hydrolysis agent is polycarbodiimide.

6. The caprolactone copolymer foam material as described in claim 5, characterized in that, The filler is silicon dioxide.

7. A method for preparing a caprolactone copolymer foam material, characterized in that, Based on the components of the caprolactone copolymer foam material according to any one of claims 1-6, it is prepared using the following steps: Step 1: Obtain thermoplastic polyurethane by bulk polymerization according to the corresponding components of thermoplastic polyurethane; Step 2: Mix the thermoplastic polyurethane obtained in Step 1 with other components to obtain a compound material; Step 3: Inject the mixed material into the mold and foam it using supercritical foaming. Step 4: After foaming is complete, cool and demold to obtain the caprolactone copolymer foam material.

8. The method for preparing a caprolactone copolymer foam material as described in claim 7, characterized in that, In step three, the supercritical foaming conditions are: nitrogen to carbon dioxide volume ratio of 75%-80% to 20%-25%; pressure during the pressurization stage is 12-14 MPa, temperature is 175-185℃, and pressure holding time is 90-110 min.

9. A shoe sole, characterized in that, The caprolactone copolymer foam material is prepared by the method for preparing caprolactone copolymer foam material as described in claim 7 or 8.

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