Environment-friendly polyurethane shoe sole for boots and preparation process thereof

Abstract

The application discloses an environment-friendly polyurethane horse boot sole and a preparation process thereof, and particularly relates to the field of polyurethane horse boot sole preparation technology, and comprises a wear-resistant layer, an energy feedback layer and a comfortable layer which are sequentially compounded from bottom to top. The preparation process comprises the following steps: S1, preparation of three-layer premix, S2, synchronous foaming and hot-pressing forming, S3, trimming by using a water jet cutting mode after demolding, and the water pressure is 180-220 MPa. By using the polyester polyol with high bio-based carbon content and the recycled tire rubber particles, the application reduces the consumption of petroleum resources and carbon emissions, and can recover volatile organic compounds. The modified graphene and the rubber particles of the wear-resistant layer improve the wear resistance. The negative Poisson's ratio structure and the carbon nanotube aerogel of the energy feedback layer improve the energy feedback rate. The material of the comfortable layer guarantees antibiosis and comfort. The synchronous foaming-hot-pressing forming process and the like ensure the stable product quality, improve the size precision and appearance quality, shorten the production cycle, and are suitable for large-scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane boot sole preparation, and more particularly to an environmentally friendly polyurethane boot sole and a preparation process thereof. BACKGROUND

[0002] The boot sole is mainly made of a rubber outsole, supplemented by EVA, PU, TPR and other materials. The sole design usually has a heel height of about 3.5 cm, with anti-slip, wear-resistant and elastic properties, and is suitable for different terrains. At present, in the field of footwear manufacturing, polyurethane materials are increasingly favored in sole production due to their high resilience, lightweight, wear resistance, and hydrolysis resistance.

[0003] However, the current PU sole relies on petroleum-based raw materials, has a low proportion of bio-based raw materials, emits a large amount of volatile organic compounds, has a low recycling rate and is difficult to degrade, polluting the environment. In terms of performance, the wear resistance, energy feedback rate and comfort of the boot sole are not satisfactory, making it difficult to meet the needs of durability, labor-saving and comfort and health. In terms of preparation process, it is difficult to accurately control the structure and performance of each layer, the product quality is unstable, the production cycle is long and the efficiency is low, and it cannot meet the market demand for high-quality and low-cost polyurethane boot soles.

[0004] In view of the above situation, the present application provides an environmentally friendly polyurethane boot sole and a preparation process thereof. SUMMARY

[0005] In order to overcome the above-mentioned defects of the prior art, the present application provides an environmentally friendly polyurethane boot sole and a preparation process thereof to solve the problems raised in the background art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solution: an environmentally friendly polyurethane boot sole, the boot sole comprising a wear-resistant layer, an energy feedback layer and a comfortable layer compounded in turn from bottom to top:

[0007] The wear-resistant layer comprises the following components by weight: bio-based polyester polyol 40-50 parts, liquefied MDI 30-40 parts, modified graphene 0.8-1.5 parts and recycled tire rubber particles with a particle size of 0.1-0.5 mm 10-20 parts;

[0008] The energy feedback layer comprises: bio-based polyester polyol 45-55 parts, liquefied MDI 25-35 parts, carbon nanotube aerogel 1-3 parts and castor oil-based softener 8-12 parts;

[0009] The comfortable layer comprises: bio-based polyester polyol 35-45 parts, liquefied MDI 20-30 parts, microcapsule phase change material 3-5 parts and antibacterial ionic liquid 0.5-1 parts;

[0010] The bio-based polyester polyol is branched polyester polyol generated by ester exchange reaction of polyester diol prepared from castor oil and ethylene glycol depolymerization recycled PET, and has a hydroxyl value of 45-60 mgKOH / g, a functionality of 2.8-3.2, and a polyester diol molecular weight of 800-1000 Da.

[0011] Preferably, the bio-based polyester polyol is prepared by mixing castor oil, recycled PET ethylene glycol depolymerization liquid with a molecular weight of 800-1000 Da, and pentaerythritol in a mass ratio of 70-80:15-25:3-8, and under the conditions of a vacuum degree of 0.03-0.08 MPa and a temperature of 170-190 DEG C, reacting for 2-4 h, and the obtained product has a bio-based carbon content of ≥80%.

[0012] Preferably, the modified graphene is functionalized graphene subjected to surface treatment with silane coupling agent KH550, and the treatment conditions are: the amount of KH550 is 20-30% of the mass of graphene, ultrasonic treatment is carried out at 60 DEG C for 30-60 min, the sheet thickness is between 5-15 nm, and the specific surface area is 300-500 m 2 / g.

[0013] Preferably, the energy feedback layer comprises negative Poisson's ratio structural units formed by spherical cavities with a diameter of 0.5-2 mm arranged in a body-centered cubic array, the cavity wall thickness is 10-15% of the diameter, and the total cavity volume accounts for 40-55% of the volume of the layer.

[0014] Preferably, the three-layer thickness ratio of the horse boot sole is wear-resistant layer: energy feedback layer: comfort layer = 1.0-1.5:2.0-2.8:1.0, the total thickness is 12-16 mm, and when the ratio is 1.5:2.8:1, the total thickness is 16 mm, and the distribution density of the energy feedback layer cavity structure in the forefoot area of the sole is 20-30% higher than that in the heel area.

[0015] Preferably, the surface of the wear-resistant layer is provided with four-pyramid-shaped micro-protrusion textures, the height is 0.3-0.8 mm, the density is 15-25 pieces / cm 2 , and the included angle between the center lines of adjacent textures is 90 DEG -120 DEG.

[0016] The application also provides a preparation process for preparing the above-mentioned environmentally friendly polyurethane horse boot sole, which specifically comprises the following steps:

[0017] S1, preparation of three-layer premix:

[0018] S1.1, wear-resistant layer premix, according to the ratio, put the bio-based polyester polyol, modified graphene, liquefied MDI, recycled tire rubber particles into the mixing tank, first mix at 500 rpm for 2 min, then ultrasonic treatment at 700 W for 15 min;

[0019] S1.2, feedback layer premix, according to the ratio, put the bio-based polyester polyol, liquefied MDI, carbon nanotube aerogel, castor oil-based softener in the planetary mixer at 10-20 rpm revolution / 25-35 rpm rotation, mix for 15-30 min;

[0020] S1.3, comfortable layer premix, according to the ratio, mix the bio-based polyester polyol, liquefied MDI, microcapsule phase change material, antibacterial ionic liquid at 200-400 rpm for 10-20 min;

[0021] S1.4, the wear-resistant layer premix, the feedback layer premix and the comfortable layer premix are used after curing at 25±2℃ for 30-60 min;

[0022] S2, synchronous foaming and hot pressing molding:

[0023] S2.1, preheat the mold for preparing the horse shoe sole to 110-130℃;

[0024] S2.2, sequentially inject the wear-resistant layer, the feedback layer and the comfortable layer premix in order, and the injection interval time of each adjacent two layers is 5-15s;

[0025] S2.3, after clamping, foaming is carried out at a temperature of 110-120℃, and a step pressure is applied, maintaining a pressure of 4-6 MPa within 0-3 min, and then the pressure is raised to 7-9 MPa after 3 min and maintained for 5 min;

[0026] S2.4, three-stage pressure control is carried out under a vacuum auxiliary system and pressure is maintained for 5-8 min;

[0027] S3, after demolding, trimming is carried out by water jet cutting, and the water pressure is 180-220 MPa.

[0028] Preferably, an organic tin-amine composite catalyst is added in the steps of S1.1, S1.2 and S1.3, which contains: dibutyltin dilaurate 0.08-0.12 parts, bis(dimethylaminoethyl) ether 0.03-0.07 parts, based on the total weight of the polyol of each layer.

[0029] Preferably, the vacuum control of the vacuum auxiliary system in the step S2.4 is:

[0030] First stage: maintain at -0.02 MPa pressure for 60-65 s;

[0031] Second stage: maintain for 120-130s under the pressure of-0.05MPa;

[0032] Third stage: maintain for 180-195s under the pressure of-0.08MPa.

[0033] Preferably, the water jet cutting in the S3 step adopts an angular garnet abrasive with Mohs hardness of 7.5 or more, the particle size is 80-120 mesh, the cutting speed is 0.5-1.2m / min, the abrasive flow is 200-300g / min, and the mass ratio of abrasive to water is 1:3-1:5, and the roughness Ra of the shoe sole edge after cutting is less than or equal to 12.5μm.

[0034] Technical effects and advantages of the present application:

[0035] 1、The present application uses a biobased polyester polyol prepared by ester exchange reaction of polyester diol prepared from castor oil and ethylene glycol depolymerization of recycled PET as the main raw material, the biobased carbon content is greater than or equal to 80%, and the particle size of the recycled tire rubber particles in the wear-resistant layer is 0.1-0.5mm, which realizes efficient recycling of waste resources, greatly reduces the consumption of petroleum-based resources, reduces carbon emissions in the production process, and further reduces environmental pollution by recovering volatile organic compounds through a vacuum auxiliary system in the preparation process, truly realizing the unity of environmental protection and high performance.

[0036] 2、In terms of wear resistance, the modified graphene added in the wear-resistant layer and the recycled tire rubber particles synergistically act to significantly improve the service life of the shoe sole, the negative Poisson's ratio structure unit of the energy feedback layer cooperates with the carbon nanotube aerogel to greatly improve the energy feedback rate, effectively reducing walking fatigue, and the microcapsule phase change material and antibacterial ionic liquid of the comfort layer effectively improve the antibacterial rate, providing a comfortable and healthy environment for the feet.

[0037] 3、The present application adopts a synchronous foaming-thermal compression molding process, precisely controls the preparation parameters of each layer of premix, the mold temperature, the step pressure and the vacuum three-stage pressure regulation, ensures the close compounding of the three-layer structure, the thickness ratio of each layer is strictly controlled at 1.0-1.5:2.0-2.8:1.0, the total thickness deviation is less than or equal to 0.1mm, the water jet cutting trimming process makes the roughness Ra of the shoe sole edge less than or equal to 12.5μm, and significantly improves the dimensional accuracy and appearance quality of the product. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The preparation flowchart of the present application. DETAILED DESCRIPTION

[0039] Example 1,

[0040] The embodiment of the present application provides an environment-friendly polyurethane horse boot sole, which comprises, from bottom to top, a wear-resistant layer, an energy feedback layer and a comfortable layer, and specifically comprises the following components:

[0041] The bio-based polyester polyol, liquefied MDI, modified graphene, recycled tire rubber particles with a particle size of 0.3 mm, carbon nanotube aerogel, castor oil-based softener, microcapsule phase change material and antibacterial ionic liquid are used.

[0042] The bio-based polyester polyol is obtained by mixing castor oil, recycled PET glycol depolymerization liquid with a molecular weight of 800-1000 Da and pentaerythritol at a mass ratio of 70:25:5, under the conditions of a vacuum degree of 0.05 MPa and a temperature of 180 DEG C, and reacting for 3 h, and the obtained product has a bio-based carbon content of 82%, a hydroxyl value of 50 mgKOH / g and a functionality of 3.0.

[0043] The modified graphene is obtained by using KH550 in an amount of 25% of the mass of the graphene, ultrasonic treatment at 60 DEG C for 40 min, and having a sheet thickness of 10 nm and a specific surface area of 400 m² / g.

[0044] The embodiment of the present application also provides a preparation process for preparing the environment-friendly polyurethane horse boot sole.

[0045] S1, preparation of three-layer premix:

[0046] S1.1, wear-resistant layer premix, 40 parts of bio-based polyester polyol, 0.8 parts of modified graphene, 30 parts of liquefied MDI, 10 parts of recycled tire rubber particles are put into a mixing tank, first mixed at 500 rpm for 2 min, and then ultrasonic treated at 700 W for 15 min;

[0047] S1.2, feedback layer premix, 45 parts of bio-based polyester polyol, 25 parts of liquefied MDI, 1 part of carbon nanotube aerogel, 8 parts of castor oil-based softener are mixed in a planetary mixer at 10 rpm revolution / 25 rpm rotation for 15 min;

[0048] S1.3, comfortable layer premix, 35 parts of bio-based polyester polyol, 20 parts of liquefied MDI, 3 parts of microcapsule phase change material, 0.5 parts of antibacterial ionic liquid are mixed at 200 rpm for 10 min;

[0049] S1.4, the three-layer premix is aged at 25 DEG C for 30 min;

[0050] S2, synchronous foaming and hot pressing molding:

[0051] S2.1, the mold for preparing the horse boot sole is preheated to 110 DEG C;

[0052] S2.2, sequentially inject the wear-resistant layer, the energy feedback layer and the comfort layer premix, the injection interval time of each adjacent two layers is 5s;

[0053] S2.3, after the mold is closed, foaming is carried out at a temperature of 110 DEG C, and a step pressure is applied, 4MPa pressure is maintained within 0-3min, and the pressure is raised to 7MPa after 3min and maintained for 5min;

[0054] S2.4, three-stage pressure control is carried out under a vacuum auxiliary system (first stage: -0.02MPa is maintained for 62s; second stage: -0.05MPa is maintained for 125s; third stage: -0.08MPa is maintained for 185s) and pressure maintaining for 6min;

[0055] S3, after demolding, trimming is carried out in a water jet cutting mode, the water pressure is 180MPa, an angular garnet abrasive with Mohs hardness of 7.5 is used, the particle size is 80 meshes, the cutting speed is 0.5m / min, the abrasive flow is 200g / min, and the mass ratio of the abrasive to water is 1:3, and the roughness Ra of the sole edge after cutting is 10μm.

[0056] The environmental protection type polyurethane horse boot sole of the embodiment has a three-layer thickness ratio of 1.0:2.0:1.0, a total thickness of 12mm, and a total cavity volume of the energy feedback layer accounting for 40% of the volume of the layer, a distribution density of the forefoot area being 20% higher than that of the heel area, and the wear-resistant layer surface being provided with four-pyramid-shaped micro-protrusion textures with a height of 0.3mm and a density of 15 / cm², and the included angle between the center lines of adjacent textures being 90°.

[0057] Embodiment 2,

[0058] The environmental protection type polyurethane horse boot sole provided by the embodiment of the application comprises, from bottom to top, a wear-resistant layer, an energy feedback layer and a comfort layer, and specifically comprises the following components:

[0059] Bio-based polyester polyol, liquefied MDI, modified graphene, recycled tire rubber particles with a particle size of 0.3mm, carbon nanotube aerogel, castor oil-based softening agent, microcapsule phase change material and antibacterial ionic liquid;

[0060] The bio-based polyester polyol is obtained by mixing castor oil, recycled PET glycol depolymerization liquid with a molecular weight of 800-1000Da and pentaerythritol at a mass ratio of 75:20:5, and then reacting at a vacuum degree of 0.05MPa and a temperature of 180 DEG C for 3h, and has a bio-based carbon content of 85%, a hydroxyl value of 55mgKOH / g and a functionality of 3.0;

[0061] The modified graphene is obtained by ultrasonic treatment of graphene at 60 DEG C for 40min, and has a sheet thickness of 10nm and a specific surface area of 400m² / g.

[0062] The embodiment of the present application also provides a preparation process for preparing the environment-friendly polyurethane horse boot sole.

[0063] S1, preparation of three-layer premixes:

[0064] S1.1, preparation of the wear-resistant layer premix, 45 parts of bio-based polyester polyol, 1.2 parts of modified graphene, 35 parts of liquefied MDI, and 15 parts of recycled tire rubber particles are put into a mixing tank, mixed at 500 rpm for 2 min, and then ultrasonically treated at 700 W for 15 min;

[0065] S1.2, preparation of the feedback layer premix, 50 parts of bio-based polyester polyol, 30 parts of liquefied MDI, 2 parts of carbon nanotube aerogel, and 10 parts of castor oil-based softener are mixed in a planetary mixer at 15 rpm revolution / 30 rpm rotation for 20 min;

[0066] S1.3, preparation of the comfort layer premix, 40 parts of bio-based polyester polyol, 25 parts of liquefied MDI, 4 parts of microcapsule phase change material, and 0.8 parts of antibacterial ionic liquid are mixed at 300 rpm for 15 min;

[0067] S1.4, the three-layer premixes are cured at 25℃ for 45 min;

[0068] S2, simultaneous foaming and hot pressing:

[0069] S2.1, the mold for preparing the horse boot sole is preheated to 120℃;

[0070] S2.2, the wear-resistant layer, the feedback layer, and the comfort layer premixes are sequentially injected in order, and the injection interval time of each adjacent two layers is 10s;

[0071] S2.3, after the mold is closed, foaming is performed at a temperature of 115℃, and a step pressure is applied, the pressure is maintained at 5MPa within 0-3min, and then the pressure is increased to 8MPa after 3min and maintained for 5min;

[0072] S2.4, three-stage pressure control is performed under a vacuum auxiliary system (first stage: -0.02MPa for 60s; second stage: -0.05MPa for 120s; third stage: -0.08MPa for 180s) and pressure maintaining for 7min;

[0073] S3, after demolding, the edge trimming is performed in a water jet cutting mode, the water pressure is 200MPa, an angular garnet abrasive with Mohs hardness of 7.5 is used, the particle size is 100 mesh, the cutting speed is 0.8m / min, the abrasive flow is 250g / min, the mass ratio of abrasive to water is 1:4, and the roughness Ra of the sole edge after cutting is 8μm.

[0074] The environmentally friendly polyurethane horse boot sole of the embodiment has a three-layer thickness ratio of 1.2:2.5:1.0, a total thickness of 14 mm, and a total cavity volume of the energy feedback layer accounting for 48% of the volume of the layer, and the distribution density of the forefoot area is 25% higher than that of the heel area, the wear-resistant layer is provided with four-pyramid-shaped micro-protrusion textures with a height of 0.5 mm and a density of 20 pieces / cm², and the included angle between the center lines of adjacent textures is 100°.

[0075] Embodiment 3,

[0076] The environmentally friendly polyurethane horse boot sole provided by the embodiment of the present application comprises, from bottom to top, a wear-resistant layer, an energy feedback layer and a comfortable layer, and specifically comprises the following components:

[0077] The bio-based polyester polyol, liquefied MDI, modified graphene, recycled tire rubber particles with a particle size of 0.3 mm, carbon nanotube aerogel, castor oil-based softening agent, microcapsule phase change material and antibacterial ionic liquid;

[0078] The bio-based polyester polyol is obtained by mixing castor oil, recycled PET glycol depolymerization liquid with a molecular weight of 800-1000 Da and pentaerythritol at a mass ratio of 80:15:5, and then reacting at 0.05 MPa vacuum degree and 180 DEG C for 3 hours, and the product has a bio-based carbon content of 83%, a hydroxyl value of 58 mgKOH / g and a functionality of 3.2;

[0079] The modified graphene is obtained by adding KH550 in an amount of 25% of the mass of the graphene, and then ultrasonic treatment at 60 DEG C for 40 min, and the sheet thickness is 10 nm and the specific surface area is 400 m² / g.

[0080] The embodiment of the present application also provides a preparation process for preparing the environmentally friendly polyurethane horse boot sole.

[0081] S1, three-layer premix preparation:

[0082] S1.1, wear-resistant layer premix, 50 parts of bio-based polyester polyol, 1.5 parts of modified graphene, 40 parts of liquefied MDI, 20 parts of recycled tire rubber particles are put into a mixing tank, first mixed at 500 rpm for 2 min, and then ultrasonic treated at 700 W for 15 min;

[0083] S1.2, feedback layer premix, 55 parts of bio-based polyester polyol, 35 parts of liquefied MDI, 3 parts of carbon nanotube aerogel, 12 parts of castor oil-based softening agent are mixed in a planetary mixer at 20 rpm revolution / 35 rpm rotation for 30 min;

[0084] S1.3, comfortable layer premix, 45 parts of bio-based polyester polyol, 30 parts of liquefied MDI, 5 parts of microcapsule phase change material, 1 part of antibacterial ionic liquid are mixed at 400 rpm for 20 min.

[0085] S1.4, the three-layer premix is matured at 25°C for 60 min;

[0086] S2, synchronous foaming and hot-pressing molding:

[0087] S2.1, the mold for preparing the horse shoe sole is preheated to 130°C;

[0088] S2.2, the wear-resistant layer, the feedback layer and the comfort layer premixes are sequentially injected in order, and the injection interval time of each adjacent two layers is 15 s;

[0089] S2.3, after the mold is closed, foaming is carried out at a temperature of 120°C, and a step pressure is applied, the pressure is maintained at 6 MPa within 0-3 min, and then the pressure is increased to 9 MPa after 3 min and maintained for 5 min;

[0090] S2.4, three-stage pressure control is carried out under a vacuum auxiliary system (first stage: -0.02 MPa for 65 s; second stage: -0.05 MPa for 130 s; third stage: -0.08 MPa for 195 s) and pressure maintaining for 8 min;

[0091] S3, after demolding, trimming is carried out in a water jet cutting manner, the water pressure is 220 MPa, an angular garnet abrasive with a Mohs hardness of 7.5 is used, the particle size is 120 mesh, the cutting speed is 1.2 m / min, the abrasive flow is 300 g / min, and the mass ratio of abrasive to water is 1:5, and the sole edge roughness after cutting is Ra6μm.

[0092] The environmentally friendly polyurethane horse shoe sole of this embodiment has a three-layer thickness ratio of 1.5:2.8:1.0, a total thickness of 16 mm, and a total cavity volume of the energy feedback layer accounting for 55% of the volume of the layer, the distribution density of the forefoot area is 30% higher than that of the heel area, the wear-resistant layer surface is provided with four-pyramid-shaped micro-protrusion textures with a height of 0.8 mm and a density of 25 pieces / cm², and the included angle between the center lines of adjacent textures is 120°.

[0093] Comparative Example 1,

[0094] The traditional polyurethane horse shoe sole does not use a three-layer structure, the raw material is ordinary polyurethane, there is no bio-based component and functional filler, and the preparation process does not carry out steps such as synchronous foaming and vacuum assistance.

[0095] Comparative Example 2,

[0096] The same as Example 1, but the bio-based polyester polyol is replaced by a petroleum-based raw material, and the other preparation steps are the same.

[0097] Comparative Example 3,

[0098] The same as example 1, but the energy feedback layer is not provided with negative Poisson's ratio structure units, and other preparation steps are the same.

[0099] In the following, the shoe soles of examples 1-3 and comparative examples 1-3 are respectively subjected to performance tests, and the test steps are as follows:

[0100] Wear resistance test: according to GB / T3903.2-2008 "Shoe outer sole test method wear resistance", the wear resistance of the shoe sole is tested by using a wear tester, and the wear amount within a certain time is recorded;

[0101] Energy feedback performance test: a pressure sensor and a displacement sensor are used to simulate the pressure on the shoe sole when a person walks, the rebound energy of the shoe sole after being pressed is tested, and the energy feedback is calculated;

[0102] Antibacterial performance test: according to GB / T20944.3-2008 "Evaluation of antibacterial properties of textiles Part 3: oscillation method", the antibacterial test of the comfort layer is carried out, and the inhibition rate of escherichia coli and staphylococcus aureus is determined;

[0103] Thickness and structure test: the total thickness and the thickness of each layer of the shoe sole are measured by using a vernier caliper, whether the proportion meets the requirements is verified, and the cavity structure and distribution density of the energy feedback layer are observed by using a microscope;

[0104] Surface texture test: the height and density of the four-pyramid micro-protrusion texture on the surface of the wear-resistant layer are measured by using a profilometer;

[0105] Edge roughness test: according to GB / T3505-2009 "Product geometry technical specification (GPS) surface structure profile method terms, definitions and surface structure parameters", the roughness test of the edge of the cut shoe sole is carried out.

[0106] The final test table is shown in the following table:

[0107]

[0108] From the above table data, it can be seen that:

[0109] 1. In terms of wear resistance, the wear amount of the wear-resistant layer of the examples is less than that of the comparative examples, and the wear amount of example 2 is only 7.5 mm³, which is much lower than that of comparative example 1, which is 15.6 mm³, indicating that the three-layer structure and the material collocation of the present application can effectively improve the wear resistance of the shoe sole;

[0110] 2. In terms of energy feedback rate, the examples gradually improve with the optimization of the structure, and example 3 reaches 75%, while comparative example 1 is only 40%, and comparative example 3 has no negative Poisson's ratio structure unit, and the energy feedback rate is 55%, which reflects the advantages of the energy feedback layer design of the present application;

[0111] 3、Antibacterial performance, the examples are all above 99.2%, and the comparative example 1 is only 80.5%, indicating that the antibacterial ionic liquid of the comfort layer plays a good role;

[0112] 4、Total thickness, the examples strictly meet the design of 12-16mm, and the comparative examples 1 and 2 are slightly deviated, the energy feedback layer cavity volume ratio meets the design, the comparative example 3 has no such structure, and the wear-resistant layer texture height and edge roughness also show that the structure design and preparation process of the examples are more excellent;

[0113] In general, on the basis of environmental protection, the environmental protection type polyurethane boot shoe sole provided by the application is significantly superior to the traditional and partially improved shoe soles in comprehensive performance.

[0114] The above only describes the preferred embodiments of the application and is not used to limit the application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. Environment-friendly polyurethane boots sole, characterized in that: The horse boot sole comprises, from bottom to top, a wear-resistant layer, an energy feedback layer and a comfortable layer which are compounded in sequence; The wear-resistant layer comprises the following components by weight: bio-based polyester polyol 40-50 parts, liquefied MDI 30-40 parts, modified graphene 0.8-1.5 parts, and recycled tire rubber particles with a particle size of 0.1-0.5 mm 10-20 parts; The energy feedback layer comprises: bio-based polyester polyol 45-55 parts, liquefied MDI 25-35 parts, carbon nanotube aerogel 1-3 parts, and castor oil-based softener 8-12 parts; The comfortable layer comprises: bio-based polyester polyol 35-45 parts, liquefied MDI 20-30 parts, microcapsule phase change material 3-5 parts, and antibacterial ionic liquid 0.5-1 part; The bio-based polyester polyol is branched polyester polyol generated by ester exchange reaction of polyester diol prepared from castor oil and ethylene glycol depolymerization recycled PET, with a hydroxyl value of 45-60 mgKOH / g, a functionality of 2.8-3.2, and a polyester diol molecular weight of 800-1000 Da.

2. The environment-friendly polyurethane boot sole according to claim 1, characterized in that: The bio-based polyester polyol is prepared by mixing castor oil, recycled PET ethylene glycol depolymerization liquid with a molecular weight of 800-1000 Da, and pentaerythritol in a mass ratio of 70-80:15-25:3-8, and reacting under a vacuum degree of 0.03-0.08 MPa and a temperature of 170-190℃ for 2-4h, wherein the bio-based carbon content of the obtained product is ≥80%.

3. The environment-friendly polyurethane boot sole according to claim 2, characterized in that: The modified graphene is functionalized graphene treated by silane coupling agent KH550, and the treatment condition is that the amount of KH550 is 20-30% of the mass of graphene, ultrasonic treatment is performed at 60°C for 30-60 min, and the sheet thickness is 5-15 nm, and the specific surface area is 300-500 m 2 / g.

4. The environmentally friendly polyurethane horse shoe sole according to claim 3, characterized in that: The energy feedback layer comprises a negative Poisson's ratio structural unit formed by a body-centered cubic array of spherical cavities with a diameter of 0.5-2 mm formed by a polyurethane matrix, the cavity wall thickness is 10-15% of the diameter, and the total cavity volume accounts for 40-55% of the volume of the layer.

5. The environmentally friendly polyurethane horse shoe sole according to claim 4, characterized in that: The thickness ratio of the three layers of the horse boot sole is wear-resistant layer: energy feedback layer: comfortable layer = 1.0-1.5:2.0-2.8:1.0, the total thickness is 12-16 mm, and when the ratio is 1.5:2.8:1, the total thickness is 16 mm, wherein the distribution density of the energy feedback layer cavity structure in the forefoot area of the sole is 20-30% higher than that in the heel area.

6. The environmentally friendly polyurethane horse shoe sole according to claim 5, characterized in that: The surface of the wear-resistant layer is provided with four-pyramid micro-protrusion texture, height 0.3-0.8mm, density 15-25 pieces / cm 2 , and the included angle between the center lines of adjacent textures is 90°-120°.

7. A process for preparing the environmentally friendly polyurethane shoe sole of claim 6, characterized by: Specifically comprising the following steps: S1, preparation of three-layer premix: S1.1, wear-resistant layer premix, according to the ratio of claim 1, bio-based polyester polyol, modified graphene, liquefied MDI, and recycled tire rubber particles are put into a mixing tank, first mixed at 500 rpm for 2 min, and then treated with ultrasonic waves at 700 W for 15 min; S1.2, feedback layer premix, according to the ratio of claim 1, bio-based polyester polyol, liquefied MDI, carbon nanotube aerogel, and castor oil-based softener are mixed in a planetary mixer at 10-20 rpm revolution / 25-35 rpm rotation for 15-30 min; S1.3, comfortable layer premix, according to the ratio of claim 1, bio-based polyester polyol, liquefied MDI, microcapsule phase change material, and antibacterial ionic liquid are mixed at 200-400 rpm for 10-20 min; S1.4, the wear-resistant layer premix, the feedback layer premix and the comfort layer premix are used after curing at 25±2℃ for 30-60min; S2, simultaneous foaming and hot pressing: S2.1, the mold for preparing the horse boot sole is preheated to 110-130℃; S2.2, the wear-resistant layer, the feedback layer and the comfort layer premix are injected in sequence, and the injection interval time of each adjacent two layers is 5-15s; S2.3, after the mold is closed, foaming is carried out at a temperature of 110-120℃, and a step pressure is applied, and the pressure of 4-6MPa is maintained for 0-3min, and then the pressure is increased to 7-9MPa after 3min and maintained for 5min; S2.4, three-stage pressure control is carried out under the vacuum auxiliary system and the pressure is maintained for 5-8min; S3, after demolding, trimming is carried out by water jet cutting, and the water pressure is 180-220MPa.

8. The manufacturing process of claim 7, wherein: S1.1, S1.2 and S1.3, an organic tin-amine composite catalyst is added in the steps, which contains: dibutyltin dilaurate 0.08-0.12 parts, bis(dimethylaminoethyl) ether 0.03-0.07 parts, based on the total weight of the polyol of each layer.

9. The manufacturing process of claim 8, wherein: The vacuum control of the vacuum auxiliary system in step S2.4 is: First stage: maintain at -0.02MPa for 60-65s; Second stage: maintain at -0.05MPa for 120-130s; Third stage: maintain at -0.08MPa for 180-195s.

10. The manufacturing process of claim 9, wherein: In step S3, the water jet cutting uses an angular garnet abrasive with a Mohs hardness of ≥7.5, the particle size is 80-120 mesh, the cutting speed is 0.5-1.2m / min, the abrasive flow is 200-300g / min, and the mass ratio of abrasive to water is 1:3-1:5, and the roughness Ra of the sole edge after cutting is ≤12.5μm.

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