Graphene acetate cloth heating sheet

Abstract

The invention discloses a graphene acetate cloth heating sheet, which comprises an acetate cloth base material layer, a graphene conductive layer, an insulation packaging layer and an electrode, the graphene conducting layer is fixed on the acetic acid cloth base material layer through a hot-pressing composite process, a gradual change type conductive grid structure is arranged in the edge area of the graphene conducting layer, and the grid density of the gradual change type conductive grid structure is gradually reduced from the center to the edge; the outer side of the graphene conducting layer is coated with the insulating packaging layer; the electrodes are symmetrically arranged at the two ends of the graphene conducting layer and are electrically connected with the graphene conducting layer; a nanoscale bonding layer is also arranged between the acetic acid cloth base material layer and the graphene conducting layer, and is prepared by mixing polyurethane and carbon nanotubes; through the gradual change type conductive grid structure, the width of the grid lines of the gradual change type conductive grid structure is gradually increased from the center to the edge, the edge current distribution can be optimized, and the current density of the center area and the edge of the grid lines is uniform.

Description

Technical Field

[0001] The present invention relates to the technical field of electrothermal materials, and in particular to a graphene acetic acid cloth heating sheet, which is particularly suitable for flexible heating devices, intelligent wearables and medical physiotherapy products. Background Art

[0002] Due to its excellent electrical conductivity and flexibility, graphene heating sheets are widely used in various heating products. In particular, graphene can be applied to acetic acid cloth to form a heating material with very good comfort. However, there are usually the following two problems when existing graphene heating sheets are combined with other materials: Firstly, the risk of delamination caused by insufficient interlayer bonding force. There may be insufficient interfacial bonding strength between graphene and the acetic acid cloth substrate, resulting in delamination under long-term heating or mechanical stress. Delamination will damage the conductive network of the heating sheet, leading to uneven local heating or failure, and at the same time reducing the product life. Secondly, in the edge area of the existing heating sheet, due to the reduction of current density or insufficient graphene coverage, a "blind area" with low heating efficiency is formed, where the edge temperature is lower than the central area, affecting the overall heating uniformity and seriously reducing the user experience.

[0003] Therefore, the bonding force between graphene and the substrate is insufficient, and it is easy to delaminate after long-term use, resulting in a decline in heating performance; indirectly, it leads to poor flexibility of the encapsulating material. At the same time, it is easy to crack after repeated bending during use, and the structure will be damaged after repeated bending many times, affecting the service life. Due to the structural problems of existing graphene heating sheets, usually the graphene arrangement in the edge area is wider, resulting in uneven current density (i.e., high current density in the middle and low current density at the edge), poor heating effect, and easy formation of a "blind area", and the experience effect of this heating temperature is not good.

[0004] To solve the above problems, a new type of graphene heating sheet combined with acetic acid cloth is needed to form a new material and innovate the design in terms of structure. Summary of the Invention

[0005] The purpose of the present invention is to provide a graphene acetic acid cloth heating sheet to solve the problems raised in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A graphene acetic acid cloth heating sheet, characterized in that: it includes an acetic acid cloth base material layer, a graphene conductive layer, an insulating encapsulation layer and electrodes; the graphene conductive layer is fixed on the acetic acid cloth base material layer through a hot pressing composite process, and a gradient conductive grid structure is provided in the edge area of the graphene conductive layer, and the grid density of the gradient conductive grid structure gradually decreases from the center to the edge; the insulating encapsulation layer is coated on the outside of the graphene conductive layer; the electrodes are symmetrically arranged at both ends of the graphene conductive layer and are electrically connected to the graphene conductive layer; a nanoscale adhesive layer is further provided between the acetic acid cloth base material layer and the graphene conductive layer, and the nanoscale adhesive layer is made of a mixture of polyurethane and carbon nanotubes.

[0008] Preferably, the grid line width of the gradient conductive grid structure gradually increases from the center to the edge.

[0009] Preferably, the grid line width in the central area of the gradient conductive grid structure is 0.1 - 0.3 mm, and the grid line width in the edge area is 0.5 - 1.0 mm.

[0010] Preferably, the thickness of the nanoscale adhesive layer is 10 - 50 nanometers, and the content of carbon nanotubes is 5% - 15%.

[0011] Preferably, the insulating encapsulation layer is a polyimide film, the thickness of the polyimide film is 0.05 - 0.2 mm, and a groove structure matching the shape of the graphene conductive layer is provided on the inner side of the insulating encapsulation layer.

[0012] Preferably, the electrodes are silver paste electrodes, and an antioxidant layer is covered on the surface thereof, and the antioxidant layer is a nano - coating of gold or platinum.

[0013] Preferably, the thickness of the acetic acid cloth base material layer is 0.2 - 0.5 mm, and its surface is treated by plasma to form a micron - scale rough structure.

[0014] Compared with the prior art, the beneficial effects of the present invention are: the graphene acetic acid cloth heating sheet of the present invention has a gradient conductive grid structure, and the grid line width of the gradient conductive grid structure gradually increases from the center to the edge. The characteristics of this structure can optimize the edge current distribution, make the current density in the central area and the edge of the grid line uniform, and eliminate the heating blind area; at the same time, the present invention adopts a nanoscale adhesive layer, which significantly improves the bonding strength between graphene and the base material.

[0015] In addition, the flexible encapsulation design adopted by the present invention enables the graphene acetic acid cloth heating sheet to ensure stable operation when used under the condition of repeated bending, and the bending force is softer and will not cause damage to the skin, making the user experience better. Description of the Drawings

[0016] Figure 1 Schematic exploded three-dimensional structure diagram of the present invention;

[0017] Figure 2 is Figure 1 Partial enlarged view of A in;

[0018] Figure 3 Top view of the graphene conductive layer of the present invention;

[0019] Figure 4 Right view of the graphene conductive layer of the present invention;

[0020] Figure 5 is Figure 4 Partial enlarged view of B in;

[0021] Figure 6 Schematic exploded three-dimensional structure diagram of the insulation encapsulation layer of the present invention.

[0022] In the figure: 1 - acetate cloth substrate layer; 2 - graphene conductive layer; 3 - insulation encapsulation layer; 4 - electrode; 5 - gradient conductive grid structure; 6 - nano-level adhesive layer; 7 - groove structure; 8 - antioxidant layer; 9 - micro-level rough structure. Specific embodiments

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] As Figures 1 to 6 shown, the present invention is a graphene acetate cloth heating sheet. The graphene acetate cloth heating sheet adopts a new structural design. The new structure is required to make the heating temperature of the graphene acetate cloth heating sheet uniform, and it is required that the graphene acetate cloth heating sheet can withstand a certain number of times or a certain frequency of repeated bending; specifically, the graphene acetate cloth heating sheet includes an acetate cloth substrate layer 1, a graphene conductive layer 2, an insulation encapsulation layer 3, and an electrode 4. The graphene conductive layer 2 is compounded on the acetate cloth substrate layer 1 through a hot pressing process, and a gradient conductive grid structure 5 is provided in its edge region, and the grid density gradually decreases from the center to the edge (as Figure 1 and Figure 3 ), and at the same time, the grid line width of the gradient conductive grid structure 5 gradually increases from the center to the edge. Preferably, the gradient parameter is that the grid line width in the central region of the gradient conductive grid structure 5 is 0.1 - 0.3 mm, and the grid line width in the edge region is 0.5 - 1.0 mm. This design can balance the edge current density and achieve uniform heating.

[0025] Furthermore, a nanoscale adhesive layer 6 (such as Figure 1 ) is provided between the acetate fabric substrate layer 1 and the graphene conductive layer 2. It is made of a mixture of polyurethane and carbon nanotubes. The thickness of the nanoscale adhesive layer 6 is 10 - 50 nanometers, and the content of carbon nanotubes is 5% - 15%. The addition of carbon nanotubes significantly improves the interfacial bonding force and prevents delamination.

[0026] Furthermore, the insulating encapsulation layer 3 is coated on the outer side of the graphene conductive layer 2. Specifically, the insulating encapsulation layer 3 is a polyimide film, and the thickness of the polyimide film is preferably 0.05 - 0.2 mm. A groove structure 7 (such as Figure 6 ) is provided on the inner side. The groove structure 7 matches the shape of the graphene conductive layer 2 to avoid generating bubbles during encapsulation. The electrodes 4 are symmetrically arranged at both ends of the graphene conductive layer 2 and are electrically connected to the graphene conductive layer 2; preferably, the electrodes 4 are silver paste electrodes, and their surfaces are covered with a gold or platinum nano - coating as an antioxidant layer 8, with excellent antioxidant performance.

[0027] In actual use, the binding property of graphene is a key issue to be considered. When graphene is combined with acetate fabric, since graphene and acetate fabric are two completely different materials with different properties, the acetate fabric substrate layer 1 needs to be subjected to a certain process treatment to enhance its binding property; specifically, the acetate fabric substrate layer 1 is treated by plasma, so that a micron - scale rough structure 9 is formed on its surface. The thickness of the acetate fabric substrate layer 1 is preferably 0.2 - 0.5 mm, which further enhances the binding force between the acetate fabric substrate layer 1 and the graphene conductive layer 2.

[0028] The heating working principle of this graphene - acetate fabric heating sheet is as follows: First, the heating sheet is powered on. After power - on, the current enters the graphene conductive layer 2 through the electrodes 4. Due to the optimized design of the gradient conductive grid structure 5, the current distribution is uniform, and the overall temperature of the heating sheet is consistent; moreover, the nanoscale adhesive layer 6 used in this graphene - acetate fabric heating sheet ensures no delamination during long - term use, and the insulating encapsulation layer 3 provides good flexibility and protection, so that there is no risk of electric shock when used by the human body.

[0029] As a specific embodiment (Embodiment 1): The graphene conductive layer 2 is fixed on the acetate cloth substrate layer 1 with a thickness of 0.2 mm and a micro-scale rough structure 9 formed on its surface through plasma treatment by a hot pressing composite process. There is a nano-scale adhesive layer 6 with a thickness of 10 nanometers and a carbon nanotube content of 5% between the two. A gradient conductive grid structure 5 is provided in the edge area of the graphene conductive layer 2. The grid density of this structure gradually decreases from the center to the edge, and the grid line width gradually increases from the center to the edge. The grid line width in the central area is 0.1 mm, and the grid line width in the edge area is 0.5 mm. The insulation encapsulation layer 3 is a polyimide film with a thickness of 0.05 mm, and a groove structure 7 matching the shape of the graphene conductive layer 2 is provided on its inner side. The electrode 4 is a silver paste electrode, symmetrically arranged at both ends of the graphene conductive layer 2 and achieving electrical connection. The surface of the electrode 4 is covered with an antioxidant layer 8 of gold nano-coating.

[0030] Test method for this embodiment: Connect the heating sheet to the power supply, use an infrared thermal imager to measure the surface temperature distribution, and at the same time use a multimeter to measure the resistance value at the electrode 4, and record the time required for the heating sheet to reach stable heating from being powered on.

[0031] Test results: In the powered-on state, the heating sheet reaches a stable heating state in a relatively short time (about 15 seconds), the surface temperature distribution is relatively uniform, and the temperature difference between the central area and the edge area does not exceed 5 °C. The resistance value is stable within a reasonable range, indicating good electrical conductivity. The nano-scale adhesive layer 6 ensures the tight bonding between the acetate cloth substrate layer 1 and the graphene conductive layer 2, and the micro-scale rough structure 9 enhances the bonding effect. The design of the gradient conductive grid structure 5 enables a reasonable current distribution, avoiding local overheating. The polyimide film insulation encapsulation layer 3 effectively prevents electric leakage, and the antioxidant layer 8 of gold nano-coating protects the electrode 4 from oxidation, extending the service life of the heating sheet.

[0032] Embodiment 2:

[0033] Another specific embodiment: Similar to the previous embodiment, the differences are as follows: The thickness of the acetate cloth substrate layer 1 is 0.5 mm, and its surface is also treated by plasma to form a micro-scale rough structure 9. The thickness of the nano-scale adhesive layer 6 is 50 nanometers, and the carbon nanotube content is 15%. The grid line width in the central area of the gradient conductive grid structure 5 at the edge of the graphene conductive layer 2 is 0.3 mm, and the grid line width in the edge area is 1.0 mm. The insulation encapsulation layer 3 is a polyimide film with a thickness of 0.2 mm, and a groove structure 7 is provided on its inner side. The electrode 4 is a silver paste electrode, and the surface is covered with an antioxidant layer 8 of platinum nano-coating.

[0034] Test method for this embodiment: The same as the previous embodiment, measure the surface temperature distribution, resistance value, and heating stabilization time.

[0035] Test effect: After being powered on, the heating sheet reaches a stable heating state in about 20 seconds, the surface temperature distribution is uniform, and the temperature difference between the center and the edge area does not exceed 3°C. The resistance value is stable and the electrical conductivity is excellent. The overall effect of this heating sheet is similar to that of the previous embodiment; the main difference is that the performance does not decay after being bent 1000 times. After analysis, it is related to the fact that the data values of the material sizes for making the graphene acetate fabric heating sheet in this embodiment are larger than those in the previous embodiment.

[0036] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A graphene acetic acid cloth heating sheet, characterized in that: It includes an acetate fabric substrate layer (1), a graphene conductive layer (2), an insulating encapsulation layer (3) and electrodes (4); the graphene conductive layer (2) is fixed on the acetate fabric substrate layer (1) through a hot pressing and compounding process, a gradient conductive grid structure (5) is provided in the edge area of the graphene conductive layer (2), and the grid density of the gradient conductive grid structure (5) gradually decreases from the center to the edge; the insulating encapsulation layer (3) covers the outside of the graphene conductive layer (2); the electrodes (4) are symmetrically arranged at both ends of the graphene conductive layer (2) and are electrically connected to the graphene conductive layer (2); a nano-scale adhesive layer (6) is further provided between the acetate fabric substrate layer (1) and the graphene conductive layer (2), and the nano-scale adhesive layer (6) is made of a mixture of polyurethane and carbon nanotubes.

2. The graphene acetic acid cloth heating sheet according to claim 1, wherein: The grid line width of the gradient conductive grid structure (5) gradually increases from the center to the edge.

3. The graphene acetic acid fabric heating sheet according to claim 2, wherein: The grid line width in the central area of the gradient conductive grid structure (5) is 0.1 - 0.3 mm, and the grid line width in the edge area is 0.5 - 1.0 mm.

4. The graphene acetate fabric heating sheet according to claim 1, wherein: The thickness of the nano-scale adhesive layer (6) is 10 - 50 nanometers, and the content of carbon nanotubes is 5% - 15%.

5. A graphene acetic acid cloth heating sheet according to claim 1, characterized in that: The insulating encapsulation layer (3) is a polyimide film, the thickness of the polyimide film is 0.05 - 0.2 mm, and a groove structure (7) matching the shape of the graphene conductive layer (2) is provided on the inner side of the insulating encapsulation layer (3).

6. The graphene acetic acid cloth heating sheet according to claim 1, wherein: The electrodes (4) are silver paste electrodes, and an antioxidant layer (8) is covered on their surfaces, and the antioxidant layer (8) is a nano-coating of gold or platinum.

7. A graphene acetate fabric heating sheet according to claim 1, characterized in that: The thickness of the acetate fabric substrate layer (1) is 0.2 - 0.5 mm, and its surface is treated by plasma to form a micro-scale rough structure (9).

Images