Rubber elastomer capable of releasing heat and application of rubber elastomer in preparation of heating and heat preservation shoes

Abstract

The invention discloses a rubber elastomer capable of releasing heat and application of the rubber elastomer in preparation of heating and heat preservation shoes, the obtained rubber elastomer capable of releasing heat is applied to preparation of the heating and heat preservation shoes, the shoes do not need to be heated by electric energy, mechanical energy is completely converted into heat energy, and energy is saved. The problems that the heating time is limited, charging is troublesome, waste battery pollution is generated and the like due to the fact that a current heating shoe needs a battery for heating are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a rubber elastic body capable of releasing heat and application of the rubber elastic body in preparing heating and heat-insulating shoes. Background Art

[0002] In the northern high latitudes, the temperature is low in winter. In order to keep the feet warmer, people sometimes choose heated shoes or heated insoles to warm their feet when going out. However, traditional heated shoes or heated insoles need to be powered by external batteries or built-in rechargeable batteries to heat. Due to the components and batteries, this type of shoe increases the weight of the entire shoe, making it inconvenient to walk.

[0003] During the use of natural rubber products, there is a phenomenon of being squeezed, deformed and generating heat. The principle is the force between rubber molecules. When the rubber is stretched, the distance between molecules increases and absorbs external energy. When the rubber is released, the distance between molecules decreases and the absorbed energy is released, thus generating molecular energy and causing the temperature of the rubber to rise. The use of vulcanizers in the rubber mixing process forms cross-linked bonds between rubber molecules, making the rubber molecules more tightly linked and further increasing the force between rubber molecules.

[0004] In addition, when the rubber is squeezed and bent, friction will occur between the internal rubber and the additives. This internal friction will also generate heat, and the rubber itself has poor heat dissipation and a certain heat preservation ability, which further causes the temperature of the rubber product to rise when it is squeezed and deformed.

[0005] At present, in order to control the heat generation reaction of rubber products, the common practice is to improve the mixing process, add butyl rubber to natural rubber, and improve the heat resistance of rubber products; at the same time, add flow agents and dispersants to improve the fluidity of rubber and make the various components in the rubber more evenly distributed. Reinforcing agents are also needed to increase the hardness of rubber products and reduce the deformation of rubber; after all additives and rubber are fully mixed, all materials are evenly mixed together to eliminate the internal stress between materials and improve the performance stability of rubber products.

[0006] Existing battery-free heating shoes specifically solve the following technical problems: 1. The shoes have no batteries and do not need to be charged. They are heated by bending and deforming when walking, thus solving the charging troubles of traditional heated shoes and improving the convenience and environmental friendliness of wearing.

[0007] 2. The shoes improve their thermal insulation capabilities and reduce their overall weight through innovative use of internal filling materials and inner side materials, improving the heavy weight and inconvenience of walking in traditional snow boots, cotton shoes, and heated shoes, and improving the wearing feel of the shoes. Summary of the invention

[0008] In view of the problem that rubber elastomers in the prior art suffer from deformation and heat generation, the present invention provides a rubber elastomer that can release heat and use it in preparing heated and thermal insulation shoes. The obtained rubber elastomer that can release heat is used in preparing heated and thermal insulation shoes. The shoes do not require electric energy to be heated, and mechanical energy is completely converted into thermal energy, thereby solving the problems that current heated shoes require batteries for heating, resulting in limited heating time, troublesome charging, and pollution caused by waste batteries.

[0009] The technical solution of the present invention is as follows: A method for preparing a rubber elastic body capable of releasing heat comprises the following steps: 1) Raw rubber plasticizing: Add 2 parts by weight of stearic acid to every 100 parts by weight of natural rubber after cutting into an internal mixer. Set the mixer speed to 60 rpm and the pressure to 0.8 MPa to break the rubber blocks. At the same time, crush the natural rubber and heat it to 45-50°C. Put the processed natural rubber into an open mixer and prepare for plasticizing. 2) Plastication: Adjust the spacing of the rollers of the open mixing mill to 0.5 mm, and squeeze repeatedly for 10-15 minutes to expel bubbles. At the same time, add 1.1 parts by weight of accelerator N-cyclohexyl-2-benzothiazole sulfonamide (CZ) and 0.8 parts by weight of antioxidant to reduce the Mooney coefficient of the rubber. When the rubber material does not stick to the rollers, cut the rubber film and wrap it around each other to form a triangular bag to obtain a semi-finished rubber product for mixing; 3) Prepare a second open mixing mill, adjust the roller distance of the open mixing mill to 5mm, heat the roller temperature to 50℃, load the plasticized rubber semi-finished product, ensure that the rubber material completely covers the front roller, and there is a 2-3cm thick accumulation of rubber on the two rollers, add 10 parts by weight of white carbon black powder prepared by precipitation method during mixing, the particle size of the white carbon black powder is 300-400 mesh, mix for 10 minutes, add 2 parts by weight of vulcanizing agent, and mix for another 10 minutes to obtain a rubber elastomer that can release heat. The rubber elastomer that can release heat has the following technical indicators: ①The hardness of the rubber elastic body is about 35 Shore C, which is relatively soft and does not affect walking; ② In a simulated shoe environment, without wind and at a temperature of 20°C, after repeated squeezing and bending within 1 minute, the rubber elastomer has an obvious sense of temperature. The shoes made of the rubber elastomer as the midsole have an initial temperature of 16°C in the outdoor environment of -4°C. Combined with the thermal insulation material in the shoe, the foot-shaped silicone mold is used to simulate the walking state for 5 minutes, and the temperature in the shoe can rise by 4.6-4.7°C.

[0010] The rubber semi-finished product obtained by the plasticization in step 2) has a relatively high viscosity and is relatively soft. Normal rubber products still require the addition of dispersants and two-stage plasticization to allow various additives to be dispersed more evenly, reduce the internal stress of the rubber product, and make the rubber performance more stable. However, the rubber product required by the present invention needs to be in an unstable state of the rubber to retain the rubber from deformation and extrusion, resulting in changes in internal stress and thus heat.

[0011] The antioxidant in step 2) is selected from antioxidant MB (2-mercaptobenzoimidazole), which can delay the natural aging of natural rubber products and extend the service life of natural rubber products.

[0012] The silica powder prepared by the precipitation method in step 3) has larger particles than the silica powder prepared by the gas phase method. Since the use of dispersant is eliminated, the silica is difficult to disperse evenly, which will lead to partial condensation of particles. In order to ensure that the silica can be relatively evenly distributed in the rubber while retaining some condensed silica particles, 10 parts by weight of silica are added to every 100 parts by weight of rubber.

[0013] The rubber elastomer that can release heat is obtained in step 3), and is cut into pieces to form sheet rubber products, which are used to cut and make shoe midsoles. The rubber midsoles made in this way are weaker than conventional rubber soles, with a hardness of about 35 Shore C, and are relatively soft, which helps to increase the deformation amplitude of the rubber. At the same time, since large particles of white carbon black are mixed in the rubber product, the white carbon black particles rub against the rubber particles during the extrusion deformation process of the rubber product, and generate heat at the same time.

[0014] The present invention also relates to a rubber elastic body capable of releasing heat obtained by the above-mentioned preparation method, which has the following technical indicators: ①The hardness of the rubber elastic body is about 35 Shore C, which is relatively soft and does not affect walking; ② In a simulated shoe environment, without wind and at a temperature of 20°C, after repeated squeezing and bending within 1 minute, the rubber elastomer has an obvious sense of temperature. The shoes made of the rubber elastomer as the midsole have an initial temperature of 16°C in the outdoor environment of -4°C. Combined with the thermal insulation material in the shoe, the foot-shaped silicone mold is used to simulate the walking state for 5 minutes, and the temperature in the shoe can rise by 4.6-4.7°C.

[0015] The present invention also relates to the use of the above-mentioned rubber elastomer capable of releasing heat in the preparation of heating and heat-insulating shoes, specifically, to the preparation of charging-free shoes capable of heating, heat preservation and heat collection.

[0016] Compared with the prior art, the present invention has the following advantages: 1. The rubber elastic body capable of releasing heat of the present invention is used to prepare heating and heat-insulating shoes, which adopts a combination of moisture-absorbing heating fiber and aerogel to recycle the water discharged by the human body for heating. At the same time, the overall weight of the shoes is reduced, which is 30% to 40% lighter than that of traditional electrically heated shoes.

[0017] 2. The application of the rubber elastomer capable of releasing heat in the preparation of heating and heat-insulating shoes described in the present invention, wherein the shoes do not require electric energy for heating and are completely converted into heat energy through mechanical energy, thereby solving the problems that the current heating shoes require batteries for heating, resulting in limited heating time, troublesome charging, and pollution caused by waste batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a diagram of the sole structure of the heating and heat-insulating shoes prepared in the experimental example of the present invention (upper figure: insole; middle figure: midsole; lower figure: outsole); Figure 2 This is the rubber mixing flow chart in Experimental Example 1 of the present invention (1. Heating the raw rubber; 2. Adding auxiliary materials for mixing (stearic acid, accelerator, etc.) to increase the plasticity of the rubber; 3. Adding white carbon black and vulcanizer for reinforcement after the rubber softens; 4. End of mixing). DETAILED DESCRIPTION

[0019] The present invention is further described in detail below by way of examples, but these examples should not be considered as limiting the present invention.

[0020] Embodiment 1: A method for preparing a rubber elastic body capable of releasing heat comprises the following steps: 1) Raw rubber plasticizing: put the cut natural rubber into an internal mixer at a ratio of 2 kg stearic acid per 100 kg natural rubber, set the mixer speed to 60 rpm and the pressure to 0.8 MPa, crush the natural rubber and heat it to 45°C, put the processed natural rubber into an open mixer and prepare for plasticizing; 2) Plastication: Adjust the spacing of the rollers of the open mixing mill to 0.5mm, squeeze repeatedly for 10 minutes to expel bubbles, and add 1.1Kg of accelerator CZ and 0.8Kg of antioxidant MB to reduce the Mooney coefficient of the rubber. When the rubber material does not stick to the rollers, cut the rubber film and wrap it left and right to form a triangular bag to obtain a semi-finished rubber product, ready for mixing; 3) Prepare the second open mill, adjust the roller distance of the open mill to 5mm, heat the roller temperature to 50℃, load the plasticized rubber semi-finished product, ensure that the rubber material completely covers the front roller, and there is a 2-3cm thick accumulation of rubber on the two rollers, add 10Kg of white carbon black powder prepared by precipitation method during the mixing process, the particle size of the white carbon black powder prepared by precipitation method is 300 mesh ~ 400 mesh, after mixing for 10min, add 2Kg of vulcanizing agent, and mix for another 10min to obtain a rubber elastomer that can release heat. The obtained rubber elastomer that can release heat has the following technical indicators: In a simulated shoe environment, with no wind and a temperature of 20°C, after repeated squeezing and bending within 1 minute, the rubber elastomer has an obvious sense of temperature. The shoes made of the rubber elastomer as the midsole have an initial temperature of 16°C in the outdoor environment of -4°C. Combined with the thermal insulation material in the shoe, the walking state is simulated using a foot-shaped silicone mold for 5 minutes, and the temperature in the shoe rises by 4.6°C.

[0021] Embodiment 2: A method for preparing a rubber elastic body capable of releasing heat comprises the following steps: 1) Raw rubber plasticizing: put the cut natural rubber into an internal mixer at a ratio of 2 kg stearic acid per 100 kg natural rubber, set the mixer speed to 60 rpm and the pressure to 0.8 MPa, crush the natural rubber and heat it to 50°C, put the processed natural rubber into an open mixer and prepare for plasticizing; 2) Plastication: Adjust the spacing of the rollers of the mixing mill to 0.5mm, squeeze repeatedly for 15 minutes to expel bubbles, and add 1.1kg of accelerator CZ and 0.8kg of antioxidant MB to reduce the Mooney coefficient of the rubber. When the rubber material does not stick to the rollers, cut the film and wrap it around each other to form a triangular bag to obtain a semi-finished rubber product, ready for mixing; 3) Prepare the second open mill, adjust the roller distance of the open mill to 5mm, heat the roller temperature to 50℃, load the plasticized rubber semi-finished product, ensure that the rubber material completely covers the front roller, and there is a 2-3cm thick accumulation of rubber on the two rollers, add 10Kg of white carbon black powder prepared by precipitation method during the mixing process, the particle size of the white carbon black powder prepared by precipitation method is 300 mesh ~ 400 mesh, after mixing for 10min, add 2Kg of vulcanizing agent, and mix for another 10min to obtain a rubber elastomer that can release heat. The obtained rubber elastomer that can release heat has the following technical indicators: In a simulated shoe environment, with no wind and a temperature of 20°C, after repeated squeezing and bending within 1 minute, the rubber elastomer has an obvious sense of temperature. The shoes made with the rubber elastomer as the midsole have an initial temperature of 16°C at an outdoor ambient temperature of -4°C. Combined with the thermal insulation material in the shoe, the walking state is simulated using a foot-shaped silicone mold for 5 minutes, and the temperature in the shoe rises by 4.7°C.

[0022] Comparative Example 1: The difference from the embodiment is that 2 kg of dispersant (saturated fatty acid zinc salt) is added in step 3) for two-stage plasticizing, and the rest is the same as in embodiment 1.

[0023] The obtained rubber elastic body capable of releasing heat has the following technical indicators: In a simulated shoe environment, with no wind and a temperature of 20°C, after repeated squeezing and bending within 1 minute, the rubber elastomer has an obvious sense of temperature. In a shoe made with the rubber elastomer as the midsole, the initial temperature inside the shoe is 16°C at an outdoor ambient temperature of -4°C. Combined with the thermal insulation material in the shoe, a foot-shaped silicone mold is used to simulate a walking state for 5 minutes, and the temperature inside the shoe rises by 1.5°C.

[0024] Comparative Example 2: The difference from the embodiment is that the white carbon black powder prepared by the gas phase method in step 3) usually has a particle size of more than 1000 meshes, and the rest is the same as in embodiment 1.

[0025] The obtained rubber elastic body capable of releasing heat has the following technical indicators: In a simulated shoe environment, with no wind and a temperature of 20°C, after repeated squeezing and bending within 1 minute, the rubber elastomer has an obvious sense of temperature. The shoes made of the rubber elastomer as the midsole have an initial temperature of 16°C in the outdoor environment of -4°C. Combined with the thermal insulation material in the shoe, a foot-shaped silicone mold is used to simulate a walking state for 5 minutes, and the temperature in the shoe rises by 1.8°C.

[0026] Experimental example: A kind of heating insulation shoes: The shoe as a whole consists of an insole, a midsole, an outsole, and a multi-layer upper.

[0027] Figure 1 The figure is a structural diagram of the sole of the prepared heating and heat-insulating shoes (upper figure: insole; middle figure: midsole; lower figure: outsole); The outsole is a composite outsole, and the part of the outsole that contacts the ground is made of rubber with anti-wear agents added, which is wear-resistant. The upper part is made of foamed high-elastic EVA material, which increases the shock absorption performance when walking and improves the comfort when wearing and walking. In addition, the foamed EVA material contains fine bubbles, which can effectively insulate and keep warm.

[0028] The midsole is an elastomer made of rubber and silica mixed in a certain proportion. When the shoes are put on, when walking or standing, the soles are bent or squeezed, the silica particles and rubber molecules will produce friction under the action of external forces, due to the viscoelasticity and high internal friction characteristics of rubber, slight friction can release heat and cause local temperature to rise.

[0029] The insole has a porous structure, and the heat generated by the midsole is conducted upward to the sole of the foot through the porous structure. The surface of the insole (the surface in contact with the foot) is made of moisture-absorbing and heat-generating fabric. This fiber fabric can generate heat by absorbing moisture discharged from the foot, thereby further increasing the temperature inside the shoe.

[0030] The upper has three layers. The outer protective layer is made of tough first-layer leather or microfiber leather, which is waterproof and breathable, and can effectively prevent external rain and snow from entering the inside of the shoe; the middle insulation layer is filled with aerogel insulation material. The material is light but has good warmth retention effect, and can effectively isolate the heat exchange between the inside and outside of the upper; the inner side of the upper is wrapped with foam with moisture-absorbing and heat-generating fiber cloth. The foam is soft and comfortable, and the moisture-absorbing and heat-generating fiber can absorb moisture to increase the temperature.

[0031] The upper and the sole are made of one-piece molding. The upper is first sewn to the insole, then glued to the midsole with hot-melt glue, and then the outsole is injection molded through equipment. The outsole completely wraps the insole and midsole, and there is no gap in the part that fits with the upper. This ensures that rainwater will not flow into the shoes when walking on flooded roads.

[0032] Results and Discussion: 1. A rubber elastomer capable of releasing heat according to the present invention is used to prepare heating and heat-insulating shoes. The shoes do not need electric energy to be heated, but are completely converted into heat energy through mechanical energy, thereby solving the problems that the current heating shoes require batteries for heating, which results in limited heating time, troublesome charging, and pollution caused by waste batteries.

[0033] 2. The rubber elastic body capable of releasing heat of the present invention is used to prepare heating and heat-insulating shoes. The heat-insulating and heat-accumulating shoes adopt the combination of moisture-absorbing and heat-generating fibers and aerogels. The water discharged by the human body is recycled and reused for heating. At the same time, the overall weight of the shoes is reduced, which is 30% to 40% lighter than that of traditional electrically heated shoes.

[0034] 3. The rubber elastomer capable of releasing heat of the present invention is used to prepare heating and heat-insulating shoes. While having a heating effect, a carbon fiber heat-insulating material is used as a surface coating, which can effectively shield the detection of infrared thermal imaging equipment and have other concealing effects.

[0035] Charging-free design: Completely free from dependence on external power supply, users do not need to worry about battery exhaustion, which improves convenience and reliability of use.

[0036] Environmental protection and energy saving: The battery-free design reduces environmental pollution and energy consumption, which is in line with the concept of green development.

[0037] Lightweight and comfortable: The use of lightweight materials and optimized structural design allows the shoes to integrate complex functions while remaining light and comfortable, improving the user's wearing experience.

[0038] Results and Discussion: 1. By comparing Examples 1-2 with Comparative Example 1, it is shown that although the elimination of the use of dispersant leads to the aggregation of white carbon black particles, which reduces the wear resistance and overall stability of the rubber product, the natural rubber product is only used in the midsole part and does not contact the ground or is exposed to the outside, so the wear resistance and the appearance of the rubber product do not need to be considered, and the condensed white carbon black particles help to increase the friction inside the rubber product and increase the temperature.

[0039] 2. By comparing Examples 1-2 and Comparative Example 2, it is shown that since Examples 1-2 use precipitated silica with larger particle size, the surface of the rubber product after mixing is relatively rough, which helps to increase the friction of the rubber product. Since the elastomer described in the present application is not exposed to the outside, the reduction in process performance does not affect the appearance of the finished shoe.

[0040] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. Various process schemes that are not substantially different from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A method for preparing a rubber elastic body capable of releasing heat, characterized in that: The following steps are involved: 1) Raw rubber plasticizing: Add 2 parts by weight of stearic acid to every 100 parts by weight of natural rubber after cutting into an internal mixer. Set the mixer speed to 60 rpm and the pressure to 0.8 MPa to break the rubber blocks. At the same time, crush the natural rubber and heat it to 45-50°C. Put the processed natural rubber into an open mixer and prepare for plasticizing. 2) Plastication: Adjust the spacing of the rollers of the open mixing mill to 0.5 mm, and squeeze repeatedly for 10-15 minutes to expel bubbles. At the same time, add 1.1 parts by weight of accelerator N-cyclohexyl-2-benzothiazole sulfenamide and 0.8 parts by weight of antioxidant to reduce the Mooney coefficient of the rubber. When the rubber material does not stick to the rollers, cut the rubber film and wrap it left and right to form a triangular bag to obtain a rubber semi-finished product and prepare for mixing; 3) Prepare a second open mixing mill, adjust the roller distance of the open mixing mill to 5mm, heat the roller temperature to 50℃, load the plasticized rubber semi-finished product, ensure that the rubber material completely covers the front roller, and there is a 2-3cm thick accumulation of rubber on the two rollers, add 10 parts by weight of white carbon black powder prepared by precipitation method during mixing, the particle size of the white carbon black powder is 300-400 mesh, mix for 10 minutes, add 2 parts by weight of vulcanizing agent, and mix for another 10 minutes to obtain a rubber elastomer that can release heat. The rubber elastomer that can release heat has the following technical indicators: ①The hardness of the rubber elastic body is 35 Shore C, which is relatively soft and does not affect walking; ② In a simulated shoe environment, without wind and at a temperature of 20°C, after repeated squeezing and bending within 1 minute, the rubber elastomer has an obvious sense of temperature. The shoes made of the rubber elastomer as the midsole have an initial temperature of 16°C in the outdoor environment of -4°C. Combined with the thermal insulation material in the shoe, the foot-shaped silicone mold is used to simulate the walking state for 5 minutes, and the temperature in the shoe can rise by 4.6-4.7°C.

2. The method for preparing a rubber elastic body capable of releasing heat according to claim 1, characterized in that: The antioxidant described in step 2) is selected from 2-thiolbenzoimidazole.

3. A rubber elastic body capable of releasing heat, characterized in that: The rubber elastic body capable of releasing heat obtained by the method for preparing the rubber elastic body capable of releasing heat according to claim 1 or 2 has the following technical indicators: ①The hardness of the rubber elastic body is 35 Shore C, which is relatively soft and does not affect walking; ② In a simulated shoe environment, without wind and at a temperature of 20°C, after repeated squeezing and bending within 1 minute, the rubber elastomer has an obvious sense of temperature. The shoes made of the rubber elastomer as the midsole have an initial temperature of 16°C in the outdoor environment of -4°C. Combined with the thermal insulation material in the shoe, the foot-shaped silicone mold is used to simulate the walking state for 5 minutes, and the temperature in the shoe can rise by 4.6-4.7°C.

4. The use of a rubber elastic body capable of releasing heat according to claim 3 in the preparation of heating and heat-insulating shoes, characterized in that: Used to prepare charging-free shoes that can achieve heating, heat preservation and heat accumulation.

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