Composite heating structure and preparation method and application thereof

Abstract

This invention relates to a composite heating structure, its preparation method, and its application. The composite heating structure includes a support layer and a heating layer stacked sequentially, and a surface layer covering the support layer and the heating layer. The heating layer includes a bottom encapsulation layer, an electrode layer, a heating layer, and a surface encapsulation layer stacked sequentially. By designing the composite heating structure, the heating layer is directly composited onto the interior component skeleton without significantly altering or even modifying existing interior structural components. A thin surface layer is then used for direct encapsulation, achieving rapid surface heating of the interior components, reducing heat conduction paths for energy saving, and meeting industry standards for a thin, seamless, and aesthetically pleasing appearance.

Description

Technical Field

[0001] This invention relates to the field of automotive interior technology, and in particular to a composite heating structure, its preparation method, and its application. Background Technology

[0002] With the rapid iteration and development of intelligent and comfortable technologies in automotive interiors, heated car seat interior components have become a mainstream feature in mid-to-high-end models, and the market demand for heated seat interior products continues to rise. At the same time, consumers and OEMs have placed higher demands on seat interior components, requiring them to not only ensure stable heating performance but also to achieve characteristics such as lightweight design, seamless surface, and a smooth and aesthetically pleasing appearance. Balancing heating functionality, structural form, and aesthetic quality has become a core technical challenge in the current field of heated car seat interiors.

[0003] Currently, most mainstream automotive seat heating structures in the industry adopt traditional encapsulated heating solutions. These primarily involve encapsulating heating elements such as resistance wires, graphene, and graphite sheets in thick non-woven fabric, embedding them into the interior component skeleton, and then covering them with a thick outer skin structure composed of foam layers, leather layers, and mesh layers (such as the durable, non-bulging, soft composite leather cover structure for automotive seats disclosed in CN219634703U) to meet the industry's requirement for seamless finishes. However, traditional heated interior structures have extremely poor adaptability. For different vehicle models' interior exteriors and assembly standards, custom molds are usually required for production, resulting in high mold development costs and poor versatility, significantly increasing product development and mass production costs. Simultaneously, the complex multi-layered composite structure and customized production mode increase the operational processes and production difficulty for interior manufacturers, not only raising overall production costs but also leading to insufficient product structural stability and reliability.

[0004] In addition, traditional thick, multi-layered composite structures have long heat conduction paths and high thermal resistance, resulting in slow heating response and low heating efficiency. In summary, existing automotive seat heating interior structures generally suffer from numerous drawbacks, including complex structures, high production costs, poor appearance quality, low heating efficiency, and weak structural reliability. These shortcomings make it difficult to meet the current standardized, universal, and high-quality production needs of vehicle manufacturers, as well as the user experience requirements of consumers, severely hindering the high-quality development of the automotive seat interior heating industry.

[0005] Therefore, how to provide a thin, seamless, aesthetically pleasing composite structure that does not affect the heating effect has become an urgent problem to be solved. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a composite heating structure, its preparation method, and its application. By designing the composite structure, the heating layer is directly composited onto the interior component skeleton without significantly altering or even modifying existing interior structural components. A thin surface layer is then used for direct encapsulation and covering. This achieves rapid heating of the interior component surface, reduces heat conduction paths to achieve energy-saving effects, and also meets industry standards for a thin, seamless, and aesthetically pleasing appearance.

[0007] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a composite heating structure, the composite heating structure comprising a support layer and a heating layer stacked sequentially, and a surface layer covering the support layer and the heating layer; The heating layer includes a bottom encapsulation layer, an electrode layer, a heating layer, and a surface encapsulation layer stacked in sequence.

[0008] This invention, through structural design of the composite heating structure, incorporates a support layer to provide overall structural support, enhancing the tensile and bending resistance of the composite structure and preventing deformation and damage to the heating layer. The surface layer completely covers both the support and heating layers, forming an outer protective layer that isolates moisture and dust, improving insulation safety while optimizing surface feel and appearance. The heating layer is directly positioned between the support and surface layers, allowing access to the heating function layer without significant alterations to the interior structural components. The heating layer employs a sandwich structure with a bottom encapsulation layer, an electrode layer, a heating layer, and a surface encapsulation layer stacked sequentially. The double encapsulation layers completely encapsulate the electrodes and conductive heating layer, achieving inner layer sealing and insulation. This effectively prevents oxidation of the heating layer, short circuits and leakage of the electrodes, ensuring long-term stable heating power and avoiding the risk of localized overheating. The double encapsulation layers also buffer stress from bending and compression, significantly improving the fatigue resistance of the heating layer and extending its service life.

[0009] Preferably, the surface layer comprises a first porous buffer layer and a skin-friendly surface layer stacked sequentially.

[0010] Preferably, the material of the first porous buffer layer includes any one or a combination of at least two of the following: a mesh layer, a sponge, or a foam material.

[0011] Preferably, the skin-friendly surface layer comprises any one or a combination of at least two of genuine leather, synthetic leather, or knitted fabric.

[0012] Preferably, the first porous buffer layer and the skin-friendly surface layer are composited using a first adhesive.

[0013] The present invention does not limit the selection of the first adhesive. Any one or a combination of at least two of water-based polyurethane adhesives, thermosetting polyurethane adhesives, hot-melt polyurethane adhesives, and polyurethane pressure-sensitive adhesives can be selected. Other conventional industrial adhesives can also be selected, as long as they can achieve effective bonding between adjacent substrates.

[0014] Preferably, the surface layer is prepared by the following method: A first adhesive is coated on one side of the first porous buffer layer and then combined with the skin-friendly surface layer to obtain the surface layer.

[0015] In this invention, the amount of the first adhesive applied and the composite parameters in the preparation of the surface layer are adaptively adjusted according to the different first adhesives used, so as to ensure that the bonding interface is firmly bonded, free of bubbles, and free of delamination defects.

[0016] Preferably, the first adhesive is a water-based polyurethane adhesive.

[0017] Preferably, the coating amount of the waterborne polyurethane adhesive is 50-100 g / m². 2 For example, it could be 50 g / m 2 60g / m 2 70 g / m 2 80 g / m 2 90 g / m 2 Or 100 g / m 2 wait.

[0018] Preferably, the waterborne polyurethane adhesive is compounded under a pressure of 0.5-0.7 MPa (e.g., 0.5 MPa, 0.55 MPa, 0.6 MPa, 0.65 MPa, or 0.7 MPa).

[0019] Preferably, the composite temperature of the waterborne polyurethane adhesive is 40-80℃ (e.g., 40℃, 50℃, 60℃, 70℃ or 80℃, etc.), and the time is 10-20 s (e.g., 10 s, 12 s, 14 s, 15 s, 16 s, 18 s or 20 s, etc.).

[0020] Preferably, the thickness of the first porous buffer layer is ≤2 mm, for example, it can be 0.2 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm or 2 mm, etc.

[0021] Preferably, the thickness of the skin-friendly surface layer is 0.3-2 mm, for example, it can be 0.3 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm or 2 mm, etc.

[0022] Preferably, the support layer comprises a skeleton layer and a second porous buffer layer stacked sequentially.

[0023] This invention does not limit the material and thickness of the skeleton layer. ABS, PP, or other various composite materials can be used as conventional skeleton substrates in the automotive interior field, as long as they have structural support performance that supports shaping and resists deformation.

[0024] Preferably, the material of the second porous buffer layer includes any one or a combination of at least two of the following: a mesh layer, a sponge, or a foam material.

[0025] Preferably, the skeleton layer and the second porous buffer layer are composited using a second adhesive.

[0026] The present invention does not limit the selection of the second adhesive. Any one or a combination of at least two of water-based polyurethane adhesives, thermosetting polyurethane adhesives, hot-melt polyurethane adhesives, and polyurethane pressure-sensitive adhesives can be selected. Other conventional industrial adhesives can also be selected, as long as they can achieve effective bonding between adjacent substrates.

[0027] Preferably, the support layer is prepared by the following method: A second adhesive is coated on one side of the second porous buffer layer and then combined with the skeleton layer to obtain the support layer.

[0028] In this invention, the amount of the second adhesive applied and the composite parameters in the preparation of the support layer are adaptively adjusted according to the different second adhesives used, so as to ensure that the bonding interface is firmly bonded, free of bubbles, and free of delamination defects.

[0029] Preferably, the second adhesive is a water-based polyurethane adhesive.

[0030] Preferably, the coating amount of the waterborne polyurethane adhesive is 50-100 g / m². 2 For example, it could be 50 g / m 2 60g / m 2 70 g / m 2 80 g / m 2 90 g / m 2 Or 100 g / m 2 wait.

[0031] Preferably, the waterborne polyurethane adhesive is compounded under a pressure of 0.5-0.7 MPa (e.g., 0.5 MPa, 0.55 MPa, 0.6 MPa, 0.65 MPa, or 0.7 MPa).

[0032] Preferably, the composite temperature of the waterborne polyurethane adhesive is 40-80℃ (e.g., 40℃, 50℃, 60℃, 70℃ or 80℃, etc.), and the time is 10-20 s (e.g., 10 s, 12 s, 14 s, 15 s, 16 s, 18 s or 20 s, etc.).

[0033] Preferably, the thickness of the second porous buffer layer is ≤8 mm, for example, it can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm or 8 mm, etc.

[0034] Preferably, the materials of the bottom encapsulation layer and the top encapsulation layer each independently include any one or a combination of at least two of non-woven fabric, fleece, woven fabric or air cotton.

[0035] Preferably, the thickness of the bottom encapsulation layer is 0.1-0.5 mm, for example, it can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm.

[0036] Preferably, the thickness of the surface encapsulation layer is 0.1-1.5 mm, for example, it can be 0.1 mm, 0.2 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm or 1.5 mm, etc.

[0037] This invention does not limit the selection of the electrode layer. The electrode layer can be made of various conductive materials such as copper foil, aluminum foil, copper strip, silver paste circuit, conductive paste circuit, FCCL, FPC, etc., as long as it can achieve the function of conducting electricity.

[0038] Preferably, the thickness of the electrode layer is 0.01-0.5 mm, for example, it can be 0.01 mm, 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm, etc.

[0039] Preferably, the material of the heating layer includes any one or a combination of at least two of the following: carbon nanotube film, graphene, graphite, or ultrafine resistance wire.

[0040] Preferably, the thickness of the heating layer is 0.005-0.15 mm, for example, it can be 0.005 mm, 0.01 mm, 0.05 mm, 0.1 mm or 0.15 mm.

[0041] Preferably, the electrode layer is electrically connected to the heating layer.

[0042] Preferably, the support layer, heating layer, and surface layer are composited using a third adhesive.

[0043] The present invention does not limit the selection of the third adhesive. Any one or a combination of at least two of water-based polyurethane adhesives, thermosetting polyurethane adhesives, hot-melt polyurethane adhesives, and polyurethane pressure-sensitive adhesives can be selected. Other conventional industrial adhesives can also be selected, as long as they can achieve effective bonding between adjacent substrates.

[0044] In this invention, the overall thickness of the heating layer is ≤3 mm and it has excellent flexibility. Combined with the first porous buffer layer with a thickness of ≤2 mm in the surface layer, it can effectively shorten the heat transmission path while meeting the appearance standard requirements, thus achieving the effect of rapid heating of the skin.

[0045] In a second aspect, the present invention provides a method for preparing the composite heating structure as described in the first aspect, the method comprising the following steps: (1) The support layer and the heating layer are stacked sequentially to obtain a support layer-heating layer structure; (2) The surface layer is covered with the support layer-heating layer structure and then cured to obtain the composite heating structure.

[0046] Preferably, in step (1), the heating layer is coated with a third adhesive on both sides, on the side where the support layer and the heating layer are combined, and on the side where the surface layer covers the support layer-heating layer structure.

[0047] In this invention, the coating amount of the third adhesive and the composite parameters in the preparation of the composite heating structure are adaptively adjusted according to the different third adhesives used, ensuring that the bonding interface is firm, free of bubbles, and free of delamination defects. If a water-based adhesive is used, the side where the support layer and the heating layer are composited is coated with the third adhesive and then dried, and the side where the surface layer covers the support layer is coated with the third adhesive and then dried. This avoids adhesion problems caused by water-based adhesive overflow, improves process operability, and reduces the difficulty of process operation.

[0048] Preferably, the third adhesive comprises an aqueous polyurethane adhesive.

[0049] Preferably, the coating amount of the third adhesive on both sides of the heating layer is independently 50-100 g / m. 2 For example, it could be 50 g / m 2 60 g / m 2 70 g / m 2 80 g / m 2 90 g / m 2Or 100 g / m 2 wait.

[0050] Preferably, the third adhesive is applied at a rate of 50-100 g / m² on the side where the support layer and the heating layer are combined. 2 For example, it could be 50 g / m 2 60 g / m 2 70 g / m 2 80 g / m 2 90 g / m 2 Or 100 g / m 2 wait.

[0051] Preferably, the amount of the third adhesive applied to the side of the surface layer covering the support layer-heating layer structure is 50-100 g / m². 2 For example, it could be 50 g / m 2 60 g / m 2 70 g / m 2 80 g / m 2 90 g / m 2 Or 100 g / m 2 wait.

[0052] Preferably, the heating layer is coated with a third adhesive on both sides and then dried. The drying temperature is 75-90℃ (e.g., 75℃, 80℃, 85℃ or 90℃) and the time is 10-30 min (e.g., 10 min, 15 min, 20 min, 25 min or 30 min).

[0053] Preferably, the side of the support layer and the heating layer that is composite is coated with a third adhesive and then dried. The drying temperature is 75-90℃ (e.g., 75℃, 80℃, 85℃ or 90℃) and the time is 10-30 min (e.g., 10 min, 15 min, 20 min, 25 min or 30 min).

[0054] Preferably, the surface layer is coated with a third adhesive on one side of the support layer and then dried. The drying temperature is 75-90℃ (e.g., 75℃, 80℃, 85℃ or 90℃) and the time is 10-30 min (e.g., 10 min, 15 min, 20 min, 25 min or 30 min).

[0055] Preferably, the curing in step (2) is carried out under a negative pressure of -0.085 to -0.095 MPa (for example, it can be -0.085 MPa, -0.09 MPa or -0.095 MPa, etc.).

[0056] Preferably, the ripening temperature in step (2) is 80-130℃ and the time is 10-50 s.

[0057] Thirdly, the present invention provides an application of the composite heating structure as described in the first aspect in automotive interiors.

[0058] Compared with the prior art, the present invention has at least the following beneficial effects: (1) By designing the composite heating structure, the present invention directly composites the heating layer onto the interior component skeleton without significantly modifying or even modifying the existing interior structural components, and directly encapsulates and covers it with a thin surface layer. This not only achieves rapid heating of the interior component surface and reduces the heat conduction path to achieve energy saving, but also meets the industry's standards for a thin, seamless, and aesthetically pleasing appearance. It solves the industry pain point that in existing composite structures, due to the heating layer being embedded in the interior component skeleton, a thicker heating layer and panel covering must be used, and a special skeleton mold must be opened to meet the goal of seamlessness.

[0059] (2) The composite heating structure preparation method provided by the present invention is simple, and there is no need to embed the heating layer into the interior part skeleton and use a multi-layer thick skin structure for encapsulation, which reduces the processing cost and improves the operational stability. Attached Figure Description

[0060] Figure 1 This is a schematic cross-sectional view of the composite heating structure provided by the present invention; Wherein, 1-the surface layer covering the support layer and the heating layer, 101-the skin-friendly surface layer, 102-the first porous buffer layer; 2-Heating layer, 201-Surface encapsulation layer, 202-Heating layer, 203-Electrode layer, 204-Bottom encapsulation layer; 3-Support layer, 301-Second porous buffer layer, 302-Skeleton layer. Detailed Implementation

[0061] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0062] The waterborne polyurethane adhesives used in the following examples and comparative examples comprise a waterborne polyurethane adhesive obtained by mixing a base adhesive (Swifttak 6888, purchased from Fuller Adhesive) and a curing agent (Swifthardener 9338B, purchased from Fuller Adhesive) in a mass ratio of 100:5.

[0063] Example 1 This embodiment provides a composite heating structure and its preparation method, wherein the composite heating structure is as follows: Figure 1 As shown, it includes a support layer 3 and a heating layer 2 stacked in sequence, and a surface layer 1 covering the support layer and the heating layer; The surface layer 1 includes a first porous buffer layer (mesh layer, purchased from Changzhou Aiket Textile Technology, with a thickness of 1 mm) 102 and a skin-friendly surface layer (Nappa, purchased from Suzhou Ruigao New Materials Co., Ltd., with a thickness of 1 mm) 101, which are stacked together. The heating layer 2 comprises, in sequence, a bottom encapsulation layer (non-woven fabric, purchased from Kunshan Huayang Fabric Technology, with a thickness of 0.3 mm) 204, an electrode layer (copper material 3S101020E WD, purchased from Shenzhen Huasheng Huiteng Technology, with a thickness of 0.3 mm) 203, a heating layer (carbon nanotubes, purchased from Suzhou Jiedi Nanotechnology, with a thickness of 0.01 mm) 202, and a surface encapsulation layer (non-woven fabric, purchased from Kunshan Huayang Fabric Technology, with a thickness of 0.1 mm) 201; The support layer 3 includes a stacked skeleton layer (PP / ABS composite material, purchased from Changshu Automotive Trim) 302 and a second porous buffer layer (EPDM, purchased from Changzhou Aike Textile Technology, with a thickness of 3 mm) 301. The preparation method includes: (1) A water-based polyurethane adhesive is coated on one side of the first porous buffer layer, with a coating amount of 70 g / m. 2 Then, it is compounded with the skin-friendly surface layer at 0.6 MPa and 60℃ for 15 s to obtain the surface layer; A water-based polyurethane adhesive is coated on one side of the second porous buffer layer at a coating amount of 70 g / m². 2 Then, it is combined with the skeleton layer at 0.6 MPa and 60℃ for 15 s to obtain the support layer; (2) Apply water-based polyurethane adhesive to both sides of the heating layer, with a coating amount of 70 g / m. 2 The side where the support layer and heating layer are composite is coated with a water-based polyurethane adhesive at a coating amount of 70 g / m². 2 One side of the surface layer covering the support layer-heating layer structure is coated with a water-based polyurethane adhesive at a coating amount of 70 g / m². 2 They were then dried at 85℃ for 20 min. (3) The support layer and heating layer coated with water-based polyurethane adhesive are dried at 80°C for 20 min. The dried support layer and heating layer are stacked to obtain the support layer-heating layer structure. Then, the surface layer is wrapped around the support layer-heating layer structure. After vacuum curing at 110°C and -0.09 MPa for 30 s, the composite heating structure is obtained.

[0064] Example 2 This embodiment provides a composite heating structure and its preparation method, wherein the composite heating structure is as follows: Figure 1 As shown, it includes a support layer 3 and a heating layer 2 stacked in sequence, and a surface layer 1 covering the support layer and the heating layer; The surface layer 1 includes a first porous buffer layer (mesh layer, purchased from Changzhou Aike Textile Technology, with a thickness of 0.3 mm) 102 and a skin-friendly surface layer (Nappa, purchased from Suzhou Ruigao New Materials Co., Ltd., with a thickness of 0.3 mm) 101, which are stacked together. The heating layer 2 comprises, in sequence, a bottom encapsulation layer (non-woven fabric, purchased from Kunshan Huayang Fabric Technology, with a thickness of 0.1 mm) 204, an electrode layer (copper material 3S101020E WD, purchased from Shenzhen Huasheng Huiteng Technology, with a thickness of 0.01 mm) 203, a heating layer (CNT, purchased from Suzhou Jiedi Nanotechnology, with a thickness of 0.005 mm) 202, and a surface encapsulation layer (non-woven fabric, purchased from Kunshan Huayang Fabric Technology, with a thickness of 0.1 mm) 201; The support layer 3 includes a stacked skeleton layer (PP / ABS composite material, purchased from Changshu Automotive Trim) 302 and a second porous buffer layer (EPDM, purchased from Changzhou Aike Textile Technology, with a thickness of 3 mm) 301. The preparation method includes: (1) A water-based polyurethane adhesive is coated on one side of the first porous buffer layer, with a coating amount of 70 g / m. 2 Then, it is compounded with the skin-friendly surface layer at 0.5 MPa and 40°C for 10 s to obtain the surface layer; A water-based polyurethane adhesive is coated on one side of the second porous buffer layer at a coating amount of 50 g / m². 2 Then, it is combined with the skeleton layer at 0.5 MPa and 40℃ for 10 s to obtain the support layer; (2) Apply water-based polyurethane adhesive to both sides of the heating layer, with a coating amount of 50 g / m. 2 The side where the support layer and heating layer are composite is coated with a water-based polyurethane adhesive at a coating amount of 50 g / m². 2 One side of the surface layer covering the support layer-heating layer structure is coated with a water-based polyurethane adhesive at a coating amount of 50 g / m². 2 They were then dried at 75℃ for 10 min. (3) The support layer and heating layer coated with water-based polyurethane adhesive are dried at 75°C for 10 min. The dried support layer and heating layer are stacked to obtain the support layer-heating layer structure. Then, the surface layer is wrapped around the support layer-heating layer structure. After vacuum curing at 80°C and -0.085 MPa for 10 s, the composite heating structure is obtained.

[0065] Example 3 This embodiment provides a composite heating structure and its preparation method, wherein the composite heating structure is as follows: Figure 1 As shown, it includes a support layer 3 and a heating layer 2 stacked in sequence, and a surface layer 1 covering the support layer and the heating layer; The surface layer 1 includes a first porous buffer layer (mesh layer, purchased from Changzhou Aike Textile Technology, with a thickness of 2 mm) 102 and a skin-friendly surface layer (Nappa, purchased from Suzhou Ruigao New Materials Co., Ltd., with a thickness of 2 mm) 101, which are stacked together. The heating layer 2 comprises, in sequence, a bottom encapsulation layer (non-woven fabric, purchased from Kunshan Huayang Fabric Technology, with a thickness of 0.5 mm) 204, an electrode layer (copper material 3S101020E WD, purchased from Shenzhen Huasheng Huiteng Technology, with a thickness of 0.5 mm) 203, a heating layer (CNT, purchased from Suzhou Jiedi Nanotechnology, with a thickness of 0.15 mm) 202, and a surface encapsulation layer (non-woven fabric, purchased from Kunshan Huayang Fabric Technology, with a thickness of 1.5 mm) 201; The support layer 3 includes a stacked skeleton layer (PP / ABS composite material, purchased from Changshu Automotive Trim) 302 and a second porous buffer layer (EPDM, purchased from Changzhou Aike Textile Technology, with a thickness of 3 mm) 301. The preparation method includes: (1) A water-based polyurethane adhesive is coated on one side of the first porous buffer layer, with a coating amount of 100 g / m. 2 Then, it is compounded with the skin-friendly surface layer at 0.7 MPa and 80℃ for 20 s to obtain the surface layer; A water-based polyurethane adhesive is coated on one side of the second porous buffer layer at a coating amount of 100 g / m². 2 Then, it is combined with the skeleton layer at 0.7 MPa and 80℃ for 20 s to obtain the support layer; (2) Apply water-based polyurethane adhesive to both sides of the heating layer, with a coating amount of 100 g / m. 2 The side where the support layer and heating layer are composite is coated with a water-based polyurethane adhesive at a coating amount of 100 g / m². 2 One side of the surface layer covering the support layer-heating layer structure is coated with a water-based polyurethane adhesive at a coating amount of 100 g / m². 2 They were then dried at 90℃ for 30 min. (3) The support layer and heating layer coated with the third adhesive are dried at 90°C for 30 min. The dried support layer and heating layer are stacked to obtain the support layer-heating layer structure. Then, the surface layer is wrapped around the support layer-heating layer structure and vacuum cured at 130°C and -0.095 MPa for 50 s to obtain the composite heating structure.

[0066] Test methods The composite heating structure provided in the embodiments was subjected to the following performance tests: (1) Appearance: The composite heating structure shall be tested in accordance with QC / T 950-2019 4.1.3 and shall be free from defects such as contamination, damage, cracking, and wrinkles. (2) Peel strength between layers: The peel strength between the support layer and the heating layer, and between the support layer-heating layer structure and the surface layer were tested according to FZ / T 60011-2016 "Test Method for Peel Strength of Composite Fabrics". (3) Electrothermal performance test: Refer to QC / T 950-2019 5.9 to test the temperature rise rate; (4) Reliability test: Refer to GB / T 2423.1-2008 Low temperature test, GB / T 2423.2-2008 High temperature test, GB / T 2423.3-2016 Constant damp heat test, GB / T 2423.22-2012 Thermal shock (two-chamber shock) test and refer to QC / T 950-2019 4.1.3 for appearance test. For the composite heating structures provided in each of the 20 examples, the appearance surface is smooth without protrusions and dents, and the composite heating structure can work normally and stably after GB / T 2423 series test is qualified. The yield rate is the reliability.

[0067] The test results are shown in Table 1: Table 1 The test results show that: As demonstrated in Examples 1 to 3, this invention optimizes the design of the composite heating structure, requiring no significant modifications and even allowing for the direct reuse of existing interior structural components. The heating layer is directly laminated to the surface of the interior component's frame, and a thin surface layer is used to achieve overall encapsulation. This solution not only enables rapid heating of the interior component's surface, shortening the heat conduction path to achieve energy savings, but also meets industry requirements for thin, seamless, and aesthetically pleasing products. It solves the industry problem in existing technologies where embedding the heating layer into the interior component's frame requires a thicker heating layer and covering panel, and necessitates the creation of a dedicated frame mold to achieve a seamless appearance. This effectively simplifies the processing flow and significantly reduces production costs.

[0068] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A composite heating structure, characterized in that, The composite heating structure includes a support layer and a heating layer stacked sequentially, and a surface layer covering the support layer and the heating layer; The heating layer includes a bottom encapsulation layer, an electrode layer, a heating layer, and a surface encapsulation layer stacked in sequence.

2. The composite heating structure according to claim 1, characterized in that, The surface layer includes a first porous buffer layer and a skin-friendly surface layer stacked sequentially. Preferably, the material of the first porous buffer layer includes any one or a combination of at least two of the following: a mesh layer, a sponge, or a foam material; Preferably, the skin-friendly surface layer comprises any one or a combination of at least two of genuine leather, synthetic leather, or knitted fabric; Preferably, the first porous buffer layer and the skin-friendly surface layer are composited using a first adhesive.

3. The composite heating structure according to claim 2, characterized in that, The thickness of the first porous buffer layer is ≤2mm; Preferably, the thickness of the skin-friendly surface layer is 0.3-2 mm.

4. The composite heating structure according to any one of claims 1-3, characterized in that, The support layer includes a skeleton layer and a second porous buffer layer stacked in sequence; Preferably, the material of the second porous buffer layer includes any one or a combination of at least two of the following: a mesh layer, a sponge, or a foam material; Preferably, the skeleton layer and the second porous buffer layer are composited using a second adhesive.

5. The composite heating structure according to claim 4, characterized in that, The thickness of the second porous buffer layer is ≤8mm.

6. The composite heating structure according to any one of claims 1-4, characterized in that, The materials of the bottom encapsulation layer and the top encapsulation layer each independently include any one or a combination of at least two of the following: non-woven fabric, fleece, woven fabric, or air cotton. Preferably, the thickness of the bottom encapsulation layer is 0.1-0.5 mm; Preferably, the thickness of the surface encapsulation layer is 0.1-1.5 mm; Preferably, the thickness of the electrode layer is 0.01-0.5 mm; Preferably, the material of the heating layer includes any one or a combination of at least two of the following: carbon nanotube film, graphene, graphite, or ultrafine resistance wire; Preferably, the thickness of the heating layer is 0.005-0.15 mm; Preferably, the electrode layer is electrically connected to the heating layer.

7. The composite heating structure according to any one of claims 1-6, characterized in that, The support layer, heating layer, and surface layer are composited using a third adhesive.

8. A method for preparing a composite heating structure as described in any one of claims 1-7, characterized in that, The preparation method includes the following steps: (1) The support layer and the heating layer are stacked sequentially to obtain a support layer-heating layer structure; (2) The surface layer is covered with the support layer-heating layer structure and then cured to obtain the composite heating structure.

9. The method for preparing the composite heating structure according to claim 8, characterized in that, In step (1), the heating layer on both sides, the side where the support layer and the heating layer are combined, and the side where the surface layer covers the support layer-heating layer structure are all coated with a third adhesive.

10. The application of a composite heating structure as described in any one of claims 1-7 in automotive interiors.

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