Carbon material electrothermal film

Abstract

The utility model discloses a carbon material electrothermal film, comprising a carbon material heating layer which is electrically connected with an external power supply to realize an electrothermal conversion function. The carbon material heating layer controls the width, the length, the thickness and the like of the carbon material mainly through graphical design, namely a winding strip-shaped heating film is formed. The device is connected with an external power supply through an external terminal and a wire. According to the carbon material electrothermal film, the design of the reinforcing layer is added, the reinforcing layer is arranged between the clamping layer and the heating layer, or the reinforcing layer is attached to the surface, not in contact with the carbon material heating layer, of the clamping layer, and the reinforcing layer completely covers the area containing the carbon material heating layer. The effect of protecting the carbon material heating layer can be achieved, and the reliability of the carbon material electrothermal film is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of graphene heating solutions, and particularly relates to a carbon material electric heating film. Background Art

[0002] Graphene is a two-dimensional nanomaterial with many excellent properties, such as high theoretical specific surface area, ultra-high electron mobility, high thermal conductivity, high Young's modulus, and high light transmittance. Based on its excellent properties, graphene plays an important role in many fields.

[0003] In the field of heating solutions, electric heating sheets with graphene and other carbon material films as the heating body have been widely used. Compared with traditional metal foil electric heating films, graphene carbon materials have higher electrothermal radiation conversion efficiency and more uniform heating effects. When the carbon material film is used as the heating body in heating scenarios in direct or indirect contact with the human body, in order to ensure its comfort and tensile strength, a flexible insulating material is used as the clamping layer of the heating body. In theory, the clamping layer can protect the heating body from being broken by external forces and becoming ineffective. In practice, electric heating sheets with graphene and other carbon material films as the heating body have a significant change in resistance or even a direct open circuit after long-term use under external force, posing a risk of failure and being difficult to pass the strict stability simulation tests in some industries. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a carbon material electric heating film that can pass a kneeling pressure test of no less than 5,000 times. It includes: a carbon material heating layer and a clamping layer. The reinforcing layer is arranged between the clamping layer and the heating layer, or the reinforcing layer is attached to the surface of the clamping layer that does not contact the carbon material heating layer, and the reinforcing layer completely covers the area containing the carbon material heating layer. The carbon material heating layer mainly controls the width, length, thickness, etc. of the carbon material through graphic design.

[0005] The clamping layer can be provided with one or two layers. When the clamping layer is provided with two layers, the carbon material heating layer is clamped and fixed between the two clamping layers. At the same time, the side of the clamping layer in contact with the carbon material heating layer has an adhesive, and the adhesive can be selected from acrylic double-sided adhesive, silicone double-sided adhesive, EVA hot melt adhesive, TPU hot melt adhesive, PES hot melt adhesive, PO hot melt adhesive, or PA hot melt adhesive, etc. During preparation, the carbon material heating layer is transferred to the adhesive surface of one of the clamping layers, and the two clamping layers are covered to completely cover the carbon material heating layer and then subjected to hot pressing treatment.

[0006] The reinforcing layer is selected from a polymer film or a metal foil. Further, the reinforcing layer is selected from one of polyester film, glassine paper, nylon film, biaxially oriented polypropylene film, polyvinylidene chloride film, and biaxially oriented polystyrene film; preferably, the reinforcing layer is selected from polyester film.

[0007] In a further technical solution, the reinforcing layer is arranged between the clamping layer and the heating layer. After the carbon material heating layer is transferred to the adhesive surface of one clamping layer, the reinforcing layer is covered on the carbon material heating layer. The reinforcing layer must completely cover the carbon material heating layer and can be cut according to the pattern of the carbon material heating layer. The width and length dimensions of the cut are slightly larger than those of the carbon material heating layer, or it can be cut according to any pattern, but it must completely cover the part of the adhesive surface of the clamping layer where there is a carbon material heating layer.

[0008] In another technical solution, when the reinforcing layer is attached to the surface of the clamping layer that does not contact the carbon material heating layer, after the two clamping layers are covered to completely cover the carbon material heating layer and then hot-pressed to obtain a semi-finished product, the reinforcing layer is attached to any one or both sides of the semi-finished product to completely cover the area containing the carbon material heating layer, and then hot-pressed again. After connecting the terminals and wires, an electrothermal film is obtained.

[0009] In a further technical solution, the reinforcing layer is selected from a polymer film or a metal foil. Further, the reinforcing layer is selected from one of a polyester film, glassine paper, nylon film, biaxially oriented polypropylene film, polyvinylidene chloride film, and biaxially oriented polystyrene film.

[0010] In a further technical solution, the clamping layer is made of a flexible textile material. The electrothermal film disclosed in this solution is used in scenarios where it is in direct or indirect contact with the human body, such as the cockpit and seat cushion of a moving vehicle. The flexible textile material can meet the requirements of comfort.

[0011] In a further technical solution, the flexible textile material selected for the clamping layer has different tensile properties in the warp, weft, and diagonal directions.

[0012] In a further technical solution, the clamping layer is made of polyester fiber; specifically, the clamping layer is made of any one or a combination of two of pure polyester fabric, polyester blended fabric, microporous polyester fabric, polyester memory fabric, peach skin, spring sub-fabric, polyester taffeta, and polyester Oxford cloth. Polyester fiber has good wrinkle resistance and shape retention, and has good elasticity in aspects such as stretching, compression, and bending. It is suitable for scenarios where it is in direct or indirect contact with the human body and can still maintain a neat appearance and a stable shape even after frequent stress.

[0013] In a further technical solution, the carbon material heating layer is selected from an artificial graphite heat conduction film, a natural graphite heat conduction film, and a graphene film. Preferably, the carbon material heating layer is made of a graphene film. The carbon material heating layer has a higher electrothermal conversion efficiency compared to traditional metal material heating components. At the same time, the carbon material heating layer is softer and will not cause a foreign body sensation when in contact with the human body, providing a better user experience.

[0014] In a further technical solution, the carbon material heating layer is arranged as a meandering strip with non-connected head and tail, and terminals connected thereto are arranged at both the head and tail ends. The terminals penetrate through the clamping layer and the strengthening layer by means of riveting, and are electrically connected to the head end and the tail end of the carbon material heating layer respectively, and the wire is electrically connected to the terminals. The design of the meandering strip can cover a larger area, resulting in a larger heating area and improving the user experience.

[0015] Beneficial effects: In the carbon material electrothermal film of the present utility model, the design of the strengthening layer is added. The strengthening layer is arranged between the clamping layer and the heating layer, or the strengthening layer is attached to the surface of the clamping layer that does not contact the carbon material heating layer. The strengthening layer completely covers the area containing the carbon material heating layer, which can protect the carbon material heating layer and improve the reliability of the carbon material electrothermal film. Description of the Drawings

[0016] Figure 1 is the force-deformation curve diagram of Embodiment 1 and Embodiment 4 of the present utility model and a single functional layer.

[0017] Figure 2 is the force-deformation curve diagram of the carbon material electrothermal film of the present utility model and various composite splines.

[0018] Figure 3 In [the figure], A is the state where the clamping layer is stretched in the warp and weft directions with a tensile force of 20 N, and B is the state where the clamping layer is stretched along the 45° direction with a tensile force of 20 N.

[0019] Figure 4 is the schematic plan view of the present utility model.

[0020] Figure 5 Schematic cross-sectional view of Embodiment 1 of the present utility model.

[0021] Figure 6 is the schematic cross-sectional view of Embodiment 4 of the present utility model.

[0022] Figure 7 is the schematic cross-sectional view of Embodiment 5 of the present utility model.

[0023] Figure 8 is the schematic cross-sectional view of Embodiment 6 of the present utility model. Detailed Embodiments

[0024] The content of the present utility model will be further described below in conjunction with specific embodiments, but it should not be construed as a limitation to the present utility model. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present utility model are conventional reagents, methods, and equipment in the technical field, and there is no specific limitation on their sources, and they can be purchased in the market or prepared according to the conventional methods well known to those skilled in the art.

[0025] Unless otherwise clearly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "having" etc. will be understood to include the stated elements or components, without excluding other elements or other components.

[0026] The technical solutions of the present utility model are illustrated below through specific embodiments. It should be understood that one or more steps mentioned in the present utility model do not exclude the existence of other methods and steps before and after the combined steps, or other methods and steps can be inserted between these clearly mentioned steps. It should also be understood that these examples are only used to illustrate the present utility model and not to limit the scope of the present utility model. Unless otherwise specified, the numbers of the method steps are only for the purpose of identifying the method steps, rather than restricting the arrangement order of each method or limiting the scope of implementation of the present utility model. The change or adjustment of their relative relationship, under the condition of no substantial change in technical content, can also be regarded as the scope in which the present utility model can be implemented.

[0027] The foregoing description of the specific exemplary embodiments of the present utility model is for the purpose of illustration and exemplification. These descriptions are not intended to limit the present utility model to the precise form disclosed, and obviously, many changes and variations can be made according to the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present utility model and its practical applications, so that those skilled in the art can implement and utilize various different exemplary embodiments of the present utility model, as well as various different selections and changes. The scope of the present utility model is intended to be defined by the claims and their equivalents. Embodiment 1

[0028] As Figure 4 and Figure 5 shown, a carbon material electrothermal film includes: a carbon material heating layer 1, a clamping layer 2, a reinforcing layer 3, terminals 4, and a wire 5. The carbon material heating layer 1 is made of graphene heat-conducting film with a thickness of 40 ± 4 μm; the clamping layer 2 is made of polyurethane fiber, specifically, spring sub-fabric is selected; the reinforcing layer 3 is made of a polymer film - polyester film, specifically, PET film is selected. The reinforcing layer 3 completely covers the carbon material heating layer 1, and the reinforcing layer 3 is disposed between the clamping layer 2 and the heating layer. The carbon material heating layer 1 is arranged as a meandering strip.

[0029] Lay the clamping layer 2 with the adhesive backing 21 facing upward, transfer the carbon material heating layer 1 that has been pre-die-cut according to the designed circuit to the adhesive backing 21 surface of the clamping layer 2, and then cover the surface of the carbon material heating layer 1 with the reinforcement layer 3, and ensure that the reinforcement layer 3 completely covers the heating material layer. Lay another clamping layer 2 with the adhesive backing 21 facing downward to the bottom clamping layer 2, seal the carbon material heating layer 1 and the reinforcement layer 3, clamp them and fix them, and send them to a hot press for hot pressing. The temperature of the hot press needs to reach the bonding temperature of the hot melt adhesive. After cooling after the hot pressing, the terminal 4 penetrates the clamping layer 2 and the reinforcement layer 3 by riveting, and is electrically connected to the head and tail ends of the carbon material heating layer 1 respectively, and the wire 5 is electrically connected to the terminal 4. Example 2

[0030] In this embodiment, the carbon material heating layer 1 is made of artificial graphite film, the clamping layer 2 is made of polyurethane fiber, specifically, pure polyester fabric; the reinforcing layer 3 is made of polyester film, specifically, PET film. Other structures and processing steps are the same as those in embodiment 1. Example 3

[0031] In this embodiment, the carbon material heating layer 1 is made of natural graphite heat-conducting film, the clamping layer 2 is made of polyurethane fiber, specifically, polyester blended fabric; the reinforcing layer 3 is made of polyester film, specifically, PET film. Other structures and processing steps are the same as those in embodiment 1. Example 4

[0032] like Figure 6 As shown, a carbon material electric heating film includes: a carbon material heating layer 1, a clamping layer 2 and a reinforcing layer 3. The carbon material heating layer 1 is made of a graphene thermal conductive film with a thickness of 40±4μm; the clamping layer 2 is made of polyurethane fiber, specifically, polyester pongee; the reinforcing layer 3 is made of a polyester film, specifically, a PET film. The reinforcing layer 3 is attached to the surface of the clamping layer 2 that is not in contact with the carbon material heating layer 1, and the reinforcing layer 3 completely covers the area containing the carbon material heating layer 1.

[0033] Lay the clamping layer 2 with the side having the adhesive 21 facing upward, transfer the carbon material heating layer 1 pre-molded according to the designed circuit to the adhesive 21 side of the clamping layer 2, attach another clamping layer 2 with the adhesive 21 facing downward to the bottommost clamping layer 2, seal and clamp the carbon material heating layer 1. Send it to a hot press for hot pressing treatment, and the temperature of the hot press needs to reach the bonding temperature of the hot melt adhesive. Then attach the reinforcing layer 3 to the surface of any one clamping layer 2, and ensure that the reinforcing layer 3 completely covers the area with the heating material layer. Adjust the temperature of the hot press and perform hot pressing treatment again. After the hot pressing is completed, cool it, and obtain the carbon material electrothermal film after connecting the terminals 4 and the wires 5. Example 5

[0034] As Figure 7 shown, in this embodiment, there are two layers of the reinforcing layer 3, and the reinforcing layer 3 attaches to both the front and back sides of the carbon material heating layer 1. Other structures are the same as those in Example 1.

[0035] During the preparation process, the carbon material heating layer 1 (graphene heat conduction film) placed on the carrier tape is die-cut according to a preset pattern. The material of the carrier tape is the same as that of the reinforcing layer 3, and then the carbon material heating layer 1 attached to the carrier tape is completely covered with a layer of the reinforcing layer 3. After ensuring that the reinforcing layer 3 completely covers the area with the heating material layer, perform hot pressing treatment. Transfer the carbon material heating layer 1 with the reinforcing layer 3 covering both sides after hot pressing treatment to the adhesive 21 side of the clamping layer 2, and the clamping layer 2 is pre-laid with the side having the adhesive 21 facing upward. Another clamping layer 2 is attached to the bottommost clamping layer 2 with the adhesive 21 facing downward, and the carbon material heating layer 1 and the reinforcing layer 3 are sealed and clamped together. Send it to a hot press for hot pressing treatment, and the temperature of the hot press needs to reach the bonding temperature of the hot melt adhesive. After the hot pressing is completed, cool it, and obtain the carbon material electrothermal film after connecting the terminals 4 and the wires 5. Example 6

[0036] As Figure 8 shown, in this embodiment, there is one layer of the reinforcing layer 3 and one layer of the clamping layer 2 respectively. The carbon material heating layer 1 is arranged on the side of the clamping layer 2 having the adhesive 21, and the reinforcing layer 3 completely covers the area of the clamping layer 2 containing the carbon material heating layer 1.

[0037] During the preparation process, lay the clamping layer 2 with the side having the adhesive 21 facing upward, transfer the carbon material heating layer 1 pre-molded according to the designed circuit to the adhesive 21 side of the clamping layer 2, attach the reinforcing layer 3 and the bottommost clamping layer 2, ensure that the reinforcing layer 3 completely covers the area of the clamping layer 2 containing the carbon material heating layer 1, transfer it to a hot press for pressing, and the temperature of the hot press needs to reach the bonding temperature of the hot melt adhesive. After the hot pressing is completed, cool it, and obtain the carbon material electrothermal film after connecting the terminals 4 and the wires 5.

[0038] Comparative Example 1

[0039] In Comparative Example 1, there is no reinforcing layer, and other structures are the same as those in Example 1. During the preparation process, the carbon material heating layer was directly transferred to the side of the clamping layer with adhesive, and then adhered to it with another clamping layer to clamp and fix the carbon material heating layer. It was transferred to a hot press for pressing, and the temperature of the hot press needed to reach the bonding temperature of the hot melt adhesive. After cooling, terminals and wires were connected to obtain the carbon material electrothermal film.

[0040] Comparative Example 2

[0041] In Comparative Example 2, the carbon material electrothermal film includes a carbon material heating layer, a clamping layer, and a reinforcing layer. The carbon material heating layer is a graphene heat conduction film, and the reinforcing layer partially covers the area of the clamping layer where the carbon material heating layer is located.

[0042] Tensile test

[0043] Tensile tests were carried out on Example 1, Example 4, the carbon material heating layer, the reinforcing layer, the clamping layer (warp and weft directions), and the clamping layer (45° diagonal) in accordance with the standard "GB / T 1040 Plastics - Determination of tensile properties". The above test groups were cut into specimens with a width of 10 mm and a length of 100 mm. During the test, the gauge length was set to 50 mm, and the test speed was 10 mm / min. The carbon material heating layer was a graphene heat conduction film, the reinforcing layer was a PET film, and the clamping layer was a polyester pongee. The test results are as Figure 1 and Table 1 shows.

[0044] Table 1: Tensile test data of Example 1 and Example 4 of the present utility model and individual functional layers.

[0045]

[0046] Figure 1The curves of Plot1 and Plot2 are the force-deformation curves of the carbon material heating layer. When the deformation is about 2 mm, the carbon material heating layer reaches the yield point, and the maximum force is 14.9 - 18 N. The curves of Plot3 and Plot4 are the force-deformation curves of the reinforcement layer. When the deformation is about 2 mm, a yield also occurs. The force at the first yield point is about 45 N. It completely fractures when the deformation is 42 - 44 mm, and the maximum force is 96.5 - 98.9 N. The curves of Plot5 and Plot6 are the force-deformation curves of the clamping layer (tensile along the warp and weft directions). Before the deformation is 2 mm, the change between the deformation and the force of the clamping layer is similar to that of the carbon material heating layer, and no yield occurs during the process. It fractures when the deformation is about 12 mm, and the maximum force is 63.9 - 65.9 N. The curves of Plot7 and Plot8 are the force-deformation curves of the clamping layer (tensile along the 45° diagonal). When the deformation reaches 2 mm, its tensile force is below 5 N. It yields when the deformation is between 26 - 30 mm, and the maximum force is 74.9 N.

[0047] Theoretically, the elongation at break of the carbon material heating layer is relatively low, and the elongation at break of the clamping layer is much greater than that of the carbon material heating layer. The clamping layer will have a protective effect on the carbon material heating layer during the stretching process. However, during actual testing, the carbon material electrothermal film with only the clamping layer for protection still has situations where the resistance change exceeds the preset value or it directly opens the circuit. From the curves of Plot1 and Plot2, when the deformation of the carbon material heating layer is about 2 mm, it will reach the yield point and fracture. When it reaches near the yield point, a significant change in resistance will occur, that is, there is a risk of failure. The curves of Plot5 and Plot6 are the force-deformation curves of the clamping layer tensile along the warp and weft. Before the deformation is 2 mm, the change in its tensile force almost coincides with that of the carbon material heating layer. Theoretically, after lamination, it can have a reinforcing effect to a certain extent and protect the carbon material heating layer. But combining with the curves of Plot7 and Plot8 (clamping tensile along the 45° diagonal), it is found that the relationship between the force and the deformation change is very different from that of tensile along the warp and weft directions. The actual deformation is as Figure 3 shown. Before the deformation is 2 mm, the force required for the clamping layer to deform the same length is much less than that of the carbon material heating layer.

[0048] Based on the above tensile test data, it is preliminarily judged that when an external force is applied obliquely to the carbon material heating layer along the clamping layer, in the absence of a reinforcement layer, the carbon material heating layer deforms first under the force, and the clamping layer loses its protective effect on the carbon material heating layer.

[0049] Figure 2Plot 9 in it is the force-deformation curve of the carbon material electrothermal film in Example 1, that is, the composite spline 1 with the clamping layer - reinforcing layer - carbon material heating layer - clamping layer stacked in sequence. The first yield point of the composite spline 1 is also around 2 mm, but the force when reaching the first yield point is close to 40 N, and before the deformation amount reaches 2 mm, the tensile force required for the composite spline 1 to stretch the same deformation amount is greater than that of the carbon material heating layer. Plot 11 is the part cut from Example 1 without the carbon material heating layer, that is, the composite spline 2 with the clamping layer - reinforcing layer - clamping layer stacked in sequence. The first yield point of the composite spline 2 is at the position where the deformation amount is 4 mm. Before the deformation amount reaches 2 mm, the tensile force required for the composite spline 2 to stretch the same deformation amount is greater than that of the carbon material heating layer. Plot 12 is the force-deformation curve of the carbon material electrothermal film in Example 4, that is, the composite spline 3 with the reinforcing layer - clamping layer - carbon material heating layer - clamping layer stacked in sequence. The first yield point of the composite spline 3 is at the deformation amount of 2 mm. At the same time, the composite spline 3 also satisfies the rule that the tensile force required to stretch the same deformation amount is greater than that of the carbon material heating layer. Plot 10 is the part cut from Example 4 without the carbon material heating layer, that is, the composite spline 4 with the reinforcing layer - clamping layer - clamping layer stacked in sequence. The force-deformation curve of the composite spline 4 is similar to Plot 11. The first yield point is at the position where the deformation amount is 4 mm, and before the deformation amount reaches 2 mm, the tensile force required for the composite spline 4 to stretch the same deformation amount is greater than that of the carbon material heating layer; the specific test data is shown in Table 2.

[0050] Table 2: Tensile test data of the carbon material electrothermal film of the present utility model

[0051]

[0052] Through the above tensile test results, it can be found that after adding the reinforcing layer, before reaching the yield point of the carbon material during the tensile test, the tensile forces of the composite splines 1 - 4 all satisfy the rule that the tensile force required to stretch the same deformation amount is greater than that of the carbon material heating layer. Therefore, the introduction of the reinforcing layer plays a protective role for the carbon material heating layer. For the clamping layer, it can share part of the external force when stretched along the warp and weft directions, and can also play an effect of protecting the carbon material heating layer. However, the clamping layer is a textile material and shows anisotropy. Therefore, when stretched along the oblique direction, the carbon material heating layer is the first to bear the force. In actual use, the force may come from various directions, and the reliability of the carbon material electrothermal film protected only by the clamping layer cannot be guaranteed. When the reinforcing layer is added and satisfies the rule that the tensile force required to stretch the same deformation amount is greater than that of the carbon material heating layer, the reliability of the carbon material electrothermal film can be enhanced.

[0053] To prove that this can also be effective in actual applications, a kneeling pressure test is further carried out.

[0054] Kneeling pressure test

[0055] According to the industry standard "QC / T 950 - 2019", the carbon material electrothermal films obtained from Examples 1 - 6 and Comparative Examples were installed in the seat for kneeling pressure test. The position of the measured point was located on the seat cushion cover, and a hard hemispherical body with a diameter of 100 mm and a ballast load of 750 N ± 20 N was used to apply pressure to the measured point. After the test started, the hemispherical body was vertically pressed downward at a load speed of 750 N ± 20 N. When the hemispherical body sank into the seat surface, it stayed for 6 s, and then vertically retreated upward to the initial position. This was taken as one test cycle, and it was repeated 5,000 times, with a test frequency of 4.5 times / min. When the test at the first test position was completed, the tests were carried out on other test positions in turn. During the test process, the heating pad used a time controller and worked in a cycle of 3 minutes of power on and 4 minutes of power off. Finally, the results were inspected and recorded. If the resistance deviation value exceeded ±10% of the standard value, it was unqualified. The test results are shown in Tables 3 and 4. After the tests, the resistances of the 4 test sites in Example 1 all changed, but the changes in resistivity did not exceed 2%. The structure where the reinforcing layer is arranged in the clamping layer and encapsulated together stretches the carbon material electrothermal film when subjected to external force, and the reinforcing layer plays a protective role for the carbon material heating layer. Before the carbon material electrothermal film reaches the yield point, it is the reinforcing layer that is subjected to external force and stretched and deformed.

[0056] Table 3: Data table of kneeling pressure test at Site 1# and Site 2# of each embodiment and comparative example of the present utility model

[0057]

[0058] Table 4: Data table of kneeling pressure test at Site 3# and Site 4# of each embodiment and comparative example of the present utility model

[0059]

[0060] In Examples 2 and 3, the materials of the reinforcing layer and the clamping layer were changed, but the material properties still satisfied the rule: before the carbon material heating layer reached the yield point, under the condition of the same deformation amount, the pulling force F1 required for the reinforcing layer was greater than the pulling force F2 required for the carbon material heating layer. Although the resistance change was slightly larger compared to Example 1, after the tests, Examples 2 and 3 both met the requirements for resistivity change, with the change controlled within 5%. No obvious hot spots were found by observing with an infrared thermal imager.

[0061] Example 4 changed the position of the reinforcement layer compared to Example 1. The reinforcement layer is attached to the surface of any clamping layer without adhesive, and it is ensured that all areas containing the carbon material heating layer are covered. The site with the largest resistivity change in Example 4 is about 2%, and its reliability is second only to that of Example 1. It is verified that changing the position of the reinforcement layer can still play a protective role. On the basis of Example 1, Example 5 added an additional reinforcement layer to protect both sides of the carbon material heating layer. The resistance changes at the 4 test points in Example 5 can be controlled within 1%. Example 6 can pass the test, but the resistance change rate at each test point is about 3%. There may be a risk of failure if the number of tests is increased.

[0062] Comparative Example 1 is an encapsulation method of the prior art. The resistivity changes at Test Site 1 and Test Site 2 both exceeded 20%, indicating that the carbon material heating layer at these two sites had started to break during the test, and the resistance increased. Test Site 3 and Test Site 4 are points closer to the pressure center, and the resistance change rate exceeded 100%. From this, it can be judged that some sites have broken, so the resistance has increased by more than double. To further verify the conclusion, Comparative Example 2 was tested using a partial coverage method. Sites 1, 2, and 4 were covered by the reinforcement layer, so the resistance change rate was within the acceptable range and did not increase significantly. Test Site 3 was not covered by the reinforcement layer, and the resistivity increased by more than 100% after the test, and this site had broken and failed.

[0063] Combined with the tensile test and the kneeling pressure test, we concluded that in the carbon material heating layer, adding a reinforcement layer, the reinforcement layer can meet the rule: before the carbon material heating layer reaches the deformation amount at the yield point, the tensile force required for the reinforcement layer to stretch the same deformation amount is greater than that of the carbon material heating layer, which can enhance the reliability of the carbon material heating layer, and the resistance can still remain stable after thousands of pressure tests without failure.

[0064] In the above embodiments, the descriptions of each embodiment have their own focuses. For parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0065] The above is the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A carbon material electrothermal film, comprising: A carbon material heating layer and a clamping layer, characterized in that: it further includes a reinforcing layer, the reinforcing layer is disposed between the clamping layer and the heating layer, or the reinforcing layer is attached to the surface of the clamping layer that does not contact the carbon material heating layer, and the reinforcing layer completely covers the area containing the carbon material heating layer.

2. The carbon material electrothermal film according to claim 1, wherein: The reinforcing layer is selected from a polymer film or a metal foil.

3. The electrothermal film made of carbon material according to claim 1, characterized in that, The reinforcing layer is selected from one of a polyester film, glassine paper, nylon film, biaxially oriented polypropylene film, polyvinylidene chloride film, and biaxially oriented polystyrene film.

4. The carbon material electrothermal film according to claim 3, wherein The reinforcing layer is selected from a polyester film.

5. A carbon material electrothermal film according to claim 1, characterized in that, The clamping layer is made of a flexible textile material.

6. The electrothermal film made of carbon material according to claim 5, characterized in that, The clamping layer is made of polyester fiber.

7. The electrothermal film made of carbon material according to claim 1, wherein, The carbon material heating layer is selected from an artificial graphite heat conduction film, a natural graphite heat conduction film, and a graphene film.

8. A carbon material electrothermal film according to claim 7, characterized in that, The carbon material heating layer is selected from a graphene film.

9. The electrothermal film made of carbon material according to claim 1, wherein A back glue is further provided on the surface of the clamping layer that contacts the carbon material heating layer.

10. A carbon material electrothermal film according to claim 1, characterized in that: The carbon material heating layer is arranged as a meandering strip with its head and tail not connected.

11. A carbon material electrothermal film according to claim 10, characterized in that: It further includes a terminal and a wire. The terminal penetrates through the clamping layer and the reinforcing layer by means of riveting, and is electrically connected to the head end and the tail end of the carbon material heating layer respectively. The wire is electrically connected to the terminal.

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