Multi-layer composite cooling pad and manufacturing method thereof

Abstract

To provide a cooling pad of a multi-layer composite structure having a rational structure, a remarkable cooling effect, good air permeability, comfortable use, and excellent practicality and durability. The solution consists of, from top to bottom, a waterproof layer 1, a zoned hydrogel layer 2, a thermally conductive strip-shaped layer 3, a support layer 4, a leak-proof layer 5, and an anti-slip layer 6. The waterproof layer is made of a polyurethane film with a hydrophobic surface. The zoned hydrogel layer includes a central high-cooling zone and an edge sustained-release zone, providing cooling in different zones using different formulas. The thermally conductive strip-shaped layer uses a composite material layer made of graphene and silica gel to improve thermal conduction efficiency. The support layer is made of a porous silica gel array formed by gradient foaming EVA, and adjusts rigidity using air pressure. The leak-proof layer uses a cross-linked polyvinyl alcohol porous film to efficiently prevent leakage. The anti-slip layer is connected to the leak-proof layer via a magnetic fastener or slot structure.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to the field of cooling products, and more particularly to a multi-layer composite cooling pad and method of manufacturing the same. [Background technology]

[0002] As living standards improve, people's demand for cooling products is increasing day by day. Efficient and comfortable cooling pads are especially important when working or exercising in high-temperature environments. However, existing cooling pad technologies are mainly divided into three types: hydrogel, phase-change material, and evaporative cooling. Conventional hydrogel cooling pads achieve cooling by absorbing heat through polyacrylamide-based hydrogel, but they suffer from issues such as hydrogel seepage, uneven temperature distribution in the cooling area, and poor breathability. Phase-change material products can maintain a constant temperature, but the rigid structure of the phase-change material makes them difficult to bond. Evaporative cooling products rely on an external water source and have limited portability, so we developed a cooling pad with a multilayer composite structure. Summary of the Invention [Means for solving the problem]

[0003] In response to the shortcomings of the prior art, the present invention aims to provide a cooling pad with a multi-layer composite structure to solve the problems of conventional cooling pads, such as uneven cooling effect, poor breathability, and inconvenience in use.

[0004] In order to solve the above technical problems, the present invention is realized by the following technical means: The present invention provides a cooling pad having a multi-layer composite structure, which includes the following layer structures compositely connected in order from above: A waterproof layer made of a polyurethane film whose surface has been hydrophobically treated, and a laser-engraved macropore structure is provided on the surface of the polyurethane film, a zoned hydrogel layer including a central high cooling zone and an edge sustained release zone, and the central high cooling zone and the edge sustained release zone are connected via a sloped transition zone; a thermally conductive stripe layer, which is a composite material layer made of graphene and silica gel and has thermally conductive stripes distributed vertically on its surface; a support layer connected to the micro pressure regulating valve and having a porous silica gel array formed by gradient foaming EVA; a leak-proof layer made of a cross-linked polyvinyl alcohol porous film; An anti-slip layer with an anti-slip pattern or suction cup array on the surface.

[0005] In one preferred embodiment of the present invention, the formula of the hydrogel layer contains the following weight percentages: 45-65% acrylamide, 12-22% glycerol, 0.03-0.08% acrylamide crosslinker, 0.02-0.05% TPGDA, 0.01-0.03% polymerization initiator, and the remainder is deionized water.

[0006] In one preferred embodiment of the present invention, the zoned hydrogel layer comprises: The thickness of the central high cooling zone is 8 to 10 mm, and the proportion of acrylamide in the formula of the hydrogel layer is 50% to 60% of the total mass; The thickness of the edge sustained-release zone is 3-5 mm, and the proportion of glycerol in the hydrogel layer formula accounts for 15%-20% of the total mass.

[0007] In one preferred embodiment of the present invention, the porous silica gel array in the support layer realizes adjustment of rigidity by air pressure drive, and the adjustable range of Young's modulus under pressure load is 0.1 to 0.5 MPa.

[0008] In one preferred embodiment of the present invention, a resilient support structure is pre-embedded within the zoned hydrogel layer, the resilient support structure being a spring-like thermoplastic polyurethane support.

[0009] In one preferred embodiment of the present invention, the anti-slip pattern on the surface of the anti-slip layer is a wave-shaped, diamond-shaped or lattice-shaped protrusion structure.

[0010] In one preferred embodiment of the present invention, there is provided a method for manufacturing a multi-layer composite cooling pad, comprising the steps of: Step 1: Using hot press molding technology to produce the waterproof layer and anti-slip layer; Step 2: Apply graphene / silica gel mixed slurry on the surface of the leak-proof layer and press it into a mold to form a thermally conductive strip layer; Step 3: forming a zoned hydrogel layer on the thermally conductive strip layer using a zoned injection molding method; Step 4: stacking and pressing the waterproof layer, zoned hydrogel layer, thermal conductive strip layer and leak-proof layer with hot melt adhesive; Step 5 includes connecting the leak-proof layer and the anti-slip layer.

[0011] In one preferred embodiment of the present invention, the process for producing the hydrogel layer used in step 3 includes the following steps: The raw materials are pre-treated by mixing deionized water, acrylamide, and glycerol in a certain ratio and stirring at 30-40°C for 30-40 minutes. Vacuum copolymerization was performed by adding a crosslinking agent (0.03-0.08 wt%) and a polymerization initiator (0.01-0.03 wt%) and stirring under a vacuum of 0.08-0.09 MPa for 20-30 minutes. Zoned injection molding is a method of injecting into zoned cavities using custom molds and controlling the temperature difference between the center zone and edge zone to ≦5°C. This includes post-processing, in which the surface is flattened after UV curing and the thickness tolerance is controlled to ±0.1 mm. [Effects of the Invention]

[0012] The present invention has the following beneficial effects: This invention uses a waterproof layer and a zoned injection molding method to achieve gradient-controlled temperature with rapid cooling in the center zone and long-lasting, sustained release in the edge zone. It combines with a graphene silica gel thermal conductive strip layer to improve thermal conductivity. It uses a honeycomb support layer driven by air pressure to adapt to different pressures in different areas. It combines a cross-linked polyvinyl alcohol leak-proof film with an anti-slip layer to solve the technical problems of traditional cooling pads, such as poor breathability, uneven temperature distribution, stiff support, leakage, and slippage. It achieves the collaborative optimization of comfortable breathability, accurate temperature control, dynamic support, safe leakage prevention, and convenient maintenance.

[0013] Of course, any product embodying the present invention need not necessarily achieve all of the above advantages simultaneously. [Brief explanation of the drawings]

[0014] In order to more clearly describe the technical aspects of the embodiments of the present invention, the following briefly describes the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, and those skilled in the art can also obtain other drawings based on these drawings without paying creative labor. [Figure 1] 1 is a perspective view of a cooling pad of the present invention; [Figure 2] 1 is a cross-sectional view of a cooling pad of the present invention. [Figure 3] 1 is a manufacturing flowchart of the cooling pad of the present invention. [Figure 4] FIG. 1 is a formula diagram of the hydrogel layer of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, the technical aspects of the embodiments of the present invention will be clearly and completely described in connection with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present invention.

[0016] As shown in FIG. 1 and FIG. 2, the present invention provides a cooling pad with a multi-layer composite structure and a manufacturing method thereof, the specific composite structure of which is as follows: multilayer composite structure Waterproof layer: Made of polyurethane film with a hydrophobic surface. The surface of the polyurethane film is laser engraved to form a macropore structure. The waterproof layer is made of polyurethane film with a hydrophobic surface, and the laser-engraved macropores on the surface have a diameter of 1-5 μm and a porosity of 20%-30%. This design allows the waterproof layer to have a moisture permeability of 5000-7000 g / m. 2 It can reach 24 hours / hour, and the waterproof level can reach IPX 7, achieving an optimal balance between waterproof and breathable performance.

[0017] As shown in Figure 4, the zoned hydrogel layer includes a central high-cooling zone and an edge sustained-release zone, connected by a sloped transition zone. The central high-cooling zone is 8-10 mm thick. The hydrogel layer formula contains the following weight percentages: 50-60% acrylamide, 12-22% glycerol, 0.03-0.08% acrylamide crosslinker, 0.02-0.05% TPGDA, and 0.01-0.03% polymerization initiator, with the remainder being deionized water. The edge sustained-release zone is 3-5 mm thick, and the glycerol content of the hydrogel layer formula is 15-20% of the total weight. This zoned design allows for precise cooling based on the cooling needs of different areas. The central high-cooling zone can rapidly reduce localized high temperatures, while the edge sustained-release zones can prolong the duration of the cooling effect. The central high-cooling zone in the zoned hydrogel layer is rich in acrylamide and has strong heat absorption capabilities, allowing it to rapidly absorb heat released from the human body or the surface of an object. After absorbing heat, the water in the hydrogel transfers it to the edge sustained-release zones through molecular thermal motion. The edge sustained-release zones contain a relatively high proportion of glycerol, which, thanks to its high specific heat capacity, helps store and slowly release heat, extending the duration of cooling. At the same time, the extremely high thermal conductivity of the graphene in the thermally conductive strips allows the heat absorbed by the hydrogel layer to be rapidly transferred to the external environment along the vertical thermal conductive strips, significantly improving heat dissipation efficiency.

[0018] Thermally conductive strip layer: A composite material layer made of graphene and silica gel, in which the graphene content is 1.5% to 3% (mass fraction). The surface of this layer is provided with thermally conductive stripes distributed vertically, with the spacing between the stripes being 2 to 5 mm. The excellent thermal conductivity of graphene and the flexibility of silica gel combine to rapidly conduct heat and improve heat dissipation efficiency.

[0019] The support layer is made of a porous silica gel array formed from gradient foam EVA, with a diameter of 3 to 8 mm. The support layer is connected to a micro-pressure valve, which adjusts its stiffness through air pressure. The Young's modulus under pressure can be adjusted between 0.1 and 0.5 MPa. When the user applies pressure, it is transmitted through the porous silica gel array, and the micro-pressure valve adjusts the air pressure within the porous silica gel array accordingly. Changes in air pressure alter the stiffness of the porous silica gel array, thereby adjusting the overall hardness of the support layer, adapting to different user weights and usage scenarios and providing stable and comfortable support.

[0020] Leak-proof layer: Made of cross-linked polyvinyl alcohol porous film, the thickness of the film is 0.1-0.3 mm, and the water permeability is ≦0.01 ml / cm 2 ·h. The leak-proof layer, made of a cross-linked porous polyvinyl alcohol film, contains a large amount of hydroxyls in its molecular structure, which form a tight network structure through cross-linking. This structure gives the film minute, uniform pores, the size of which is smaller than the diameter of the liquid molecules in the hydrogel layer, effectively preventing liquid leakage from the hydrogel layer and ensuring the safety and reliability of the cooling pad.

[0021] The anti-slip layer is detachably connected to the leak-proof layer via a magnetic fastener or slot structure. The surface of the anti-slip layer is provided with an anti-slip pattern or suction cup array, which has a wave-shaped, diamond-shaped, or lattice-shaped protrusion structure. The anti-slip layer is connected to the leak-proof layer via a magnetic fastener or slot structure, and the anti-slip pattern or suction cup array on its surface provides anti-slip protection. The wave-shaped, diamond-shaped, or lattice-shaped protrusion structure of the anti-slip pattern increases friction with the contact surface, effectively preventing movement of the cooling pad when an external force attempts to compress it. The suction cup array adheres to the contact surface, generating a strong adhesive force, further preventing displacement of the cooling pad during use.

[0022] Manufacturing method (shown in Figure 3) Step 1: The waterproof and anti-slip layers were fabricated using heat press molding. For the waterproof layer, a macropore structure was created on the surface of the polyurethane film using laser engraving. The film surface was then plasma treated to create a hydrophobic surface with a contact angle of 110°-120°. For the anti-slip layer, modules with anti-slip patterns or suction cup arrays were fabricated using heat press molding according to design requirements, and other connection methods such as magnetic fasteners or slot structures were also used. Step 2: A graphene / silica gel mixed slurry is applied to the surface of the leak-proof layer and pressed into a mold to form a thermally conductive strip layer. The ratio of graphene to silica gel in the mixed slurry must be strictly controlled to ensure the thermal conductivity and flexibility of the thermally conductive strip layer. During the pressing process, the pressure and temperature must be controlled to ensure that the shape and dimensions of the thermally conductive stripe meet the design requirements. Step 3: Zonal hydrogel layers are formed on the thermally conductive strip layer using a zonal injection molding method. The raw materials are first pre-processed by mixing deionized water, acrylamide, and glycerol in a specific ratio and stirring at 30-40°C for 30-40 minutes to thoroughly dissolve and mix the materials. This is followed by vacuum copolymerization, adding a crosslinker (0.03-0.08 wt%) and a polymerization initiator (0.01-0.03 wt%) and stirring under a vacuum of 0.08-0.09 MPa for 20-30 minutes to initiate the polymerization reaction. A custom mold is used to inject the hydrogel into the zonal cavities, controlling the temperature difference between the center and edge zones to ≤5°C to ensure that the performance differences in the hydrogel layers in different regions meet the design requirements. Finally, post-processing is performed, including UV curing and surface flattening, with a thickness tolerance of ±0.1 mm. Step 4: The waterproof layer, zoned hydrogel layer, thermally conductive strip layer, and leak-proof layer are stacked and pressed together with hot melt adhesive. During the pressing process, the amount and temperature of the hot melt adhesive must be controlled to ensure a tight bond between each layer without affecting the performance of each layer. Step 5: Connect the anti-leak layer and anti-slip layer via magnetic fasteners or slot structure to complete the assembly of the cooling pad.

[0023] Specific application examples of this embodiment are as follows: Cooling pads for home, office, car, pets, outdoors, etc. Composite structure: Waterproof layer: thickness 0.1-0.3mm, density 80g / m 2 The polyurethane film is used. Zoned hydrogel layer: the central high-cooling zone was 9 mm thick and contained 55% acrylamide by mass; the edge sustained-release zone was 4 mm thick and contained 18% glycerol by mass. Thermally conductive stripe layer: The graphene content is 2.5% (mass fraction), and the spacing between the thermally conductive stripes is 3 mm. Support layer: The diameter of the porous silica gel array was 5 mm, and the air pressure was adjusted through a micro air pressure control valve to maintain the Young's modulus at 0.3 MPa. Leak-proof layer: Cross-linked polyvinyl alcohol porous film, thickness 0.2 mm. Anti-slip layer: It adopts a wave-shaped anti-slip pattern with a pattern height of 1mm, and is connected to the leak-proof layer via a magnetic fastener.

[0024] (manufacturing process) Raw material pretreatment: Mix deionized water, acrylamide, and glycerol in a certain ratio and stir at 35°C for 35 minutes. Vacuum copolymerization: Add 0.05 wt% crosslinker acrylic acid and 0.02 wt% polymerization initiator to the mixed solution, and stir under a vacuum of 0.085 MPa for 25 minutes; Zonal injection molding: Inject into a zonal cavity using a custom mold, with the center zone at 30°C and the edge zone at 28°C. Post-processing: After the injection molding is completed, the hydrogel layer is cured under UV lamp for 20 minutes, and then the surface is polished to ensure that the thickness tolerance is within ±0.1 mm. Assembly: The waterproof layer, zoned hydrogel layer, thermal conductive strip layer, and leak-proof layer are pressed together in order using hot melt adhesive, and finally the anti-slip layer is connected to the leak-proof layer using a magnetic fastener.

[0025] (Performance test) Cooling performance: Under the condition of an ambient temperature of 35°C, the cooling pad was placed in a test device simulating human skin. The test results showed that the central high cooling zone could reduce the surface temperature of the tested object by 5°C within 10 minutes, and the edge sustained release zone could reduce the temperature by 3°C within 30 minutes, and the cooling effect could last for more than 4 hours. Breathability: Tested using a breathability tester in accordance with relevant standards, the water vapor transmission rate of this cooling pad is 1200g / m 2 -It lasts 24 hours, and users have found that they do not feel stuffy even when using it for long periods of time. Support performance: By placing dummy models of different weights on the cooling pad and adjusting the micro-pressure valve, the support layer can automatically adjust its rigidity based on the weight of the model, providing stable and comfortable support for the model. Anti-slip performance: When the cooling mat is placed on a smooth tile surface and an object of a certain weight is placed on it, the measured friction coefficient is 0.8, demonstrating good anti-slip effect. Leak prevention performance: A certain amount of colored liquid was injected into the hydrogel layer and observed for 24 hours, and no leakage phenomenon was observed on the surface of the leak prevention layer.

[0026] In the description herein, references to "one embodiment," "an example," "a specific example," and the like are intended to include the specific feature, structure, material, or characteristic described in connection with at least one embodiment or example of the invention. In this specification, general references to the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0027] The preferred embodiments of the present invention disclosed above are merely intended to facilitate the description of the present invention. The preferred embodiments do not detail all the details, nor are they intended to limit the present invention to the specific embodiments described. Obviously, many modifications and variations can be made in accordance with the contents of this specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, and thus enable those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents. [Explanation of symbols]

[0028] 1. Waterproof layer; 2. Zoned hydrogel layer; 3. Thermally conductive strip layer; 4. Support layer; 5. Leak-proof layer; 6. Anti-slip layer.

Claims

1. A plate-shaped cooling pad having a multi-layer composite structure, A waterproof layer made of a polyurethane film whose surface has been hydrophobically treated, and a laser-engraved macropore structure is provided on the surface of the polyurethane film, a zonal hydrogel layer including a central high cooling zone, an edge sustained-release zone, and a sloped transition zone, the central high cooling zone being located in the central zone of the zonal hydrogel layer, the edge sustained-release zone being located in the edge zone of the zonal hydrogel layer, and the central high cooling zone and the edge sustained-release zone being connected via the sloped transition zone; a thermally conductive strip layer, which is a composite material layer made of graphene and silica gel, and has thermally conductive stripes on a surface thereof distributed along the longitudinal direction of the cooling pad in a cross-sectional view; a support layer formed of a honeycomb silica gel array made of gradient foamed EVA and connected to a micro air pressure regulating valve for regulating the air pressure within the honeycomb silica gel array; a leak-proof layer made of a cross-linked polyvinyl alcohol porous film; an anti-slip layer having an anti-slip pattern or suction cup array on its surface; A cooling pad having a multi-layer composite structure, characterized in that it includes the above layer structures which are compositely connected in order from above.

2. 2. The cooling pad of claim 1, wherein the zoned hydrogel layer has a formula comprising the following weight percents: acrylamide 45-65%, glycerol 12-22%, acrylamide crosslinker 0.03-0.08%, TPGDA 0.02-0.05%, polymerization initiator 0.01-0.03%, and the remainder deionized water.

3. In the zoned hydrogel layer, the thickness of the central high cooling zone is 8-10 mm, and the proportion of acrylamide in the formula of the hydrogel layer is 50%-60% of the total mass; The cooling pad of claim 1, characterized in that the thickness of the edge sustained-release zone is 3 to 5 mm, and the proportion of glycerol in the formula of the hydrogel layer accounts for 15% to 20% of the total mass.

4. The cooling pad of the multilayer composite structure described in claim 1, characterized in that the honeycomb silica gel arrangement of the support layer realizes rigidity adjustment by air pressure drive, and the adjustable range of Young's modulus under pressure load is 0.1 to 0.5 MPa.

5. 2. The cooling pad of claim 1, wherein the zoned hydrogel layer has a pre-embedded elastic support structure, the elastic support structure being a spring-like thermoplastic polyurethane support.

6. 2. The cooling pad of claim 1, wherein the anti-slip pattern on the surface of the anti-slip layer is a wave-shaped, diamond-shaped or lattice-shaped protrusion structure.

7. A method for manufacturing a multi-layer composite cooling pad according to any one of claims 1 to 6, comprising the steps of: Step 1: Using hot press molding technology to fabricate a waterproof layer and an anti-slip layer; Step 2: Applying graphene / silica gel mixed slurry on the surface of the leak-proof layer and pressing it into a mold to form a thermally conductive strip layer; Step 3: forming a zoned hydrogel layer on the thermally conductive strip layer using a zoned injection molding method; Step 4: stacking and pressing the waterproof layer, the zoned hydrogel layer, the thermally conductive strip layer and the leak-proof layer with hot melt adhesive; 7. The method for manufacturing the multi-layer composite cooling pad according to claim 1, further comprising the step of: (5) connecting the anti-leak layer and the anti-slip layer.

8. The manufacturing process of the hydrogel layer used in step 3 includes: The raw material is pretreated by mixing deionized water, acrylamide, and glycerol in a certain ratio and stirring at 30-40°C for 30-40 minutes. a crosslinking agent (0.03 to 0.08 wt%), a polymerization initiator (0.01 to 0.03 wt%), and a vacuum copolymerization of stirring for 20 to 30 minutes under a vacuum of 0.08 to 0.09 MPa; Zonal injection molding, in which the material is injected into zoned cavities using a custom mold and the temperature difference between the center zone and the edge zone is controlled to ≦5°C; The method for manufacturing a multi-layer composite cooling pad according to claim 7, further comprising a post-treatment of performing a surface flattening process after ultraviolet curing to control the thickness tolerance to ±0.1 mm.

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