Aluminum-plastic panel with high heat dissipation performance and preparation method of aluminum-plastic panel

Abstract

The invention provides an aluminum-plastic panel with high heat dissipation performance and a preparation method thereof, and relates to the technical field of aluminum-plastic panels, the aluminum-plastic panel comprises an upper aluminum alloy layer, a middle heat conduction composite layer and a lower aluminum alloy layer which are sequentially stacked; the middle heat-conducting composite layer is prepared from the following raw materials in parts by weight: 100 parts of a macromolecular resin matrix; 30 to 80 parts of flaky graphite powder; 20 to 50 parts of spherical aluminum oxide; 5-20 parts of carbon fiber; 1-5 parts of a coupling agent; 1-3 parts of a dispersant; 5-15 parts of a plasticizer; the high-thermal-conductivity composite material has excellent thermal conductivity, and a three-dimensional thermal conductivity network is formed by adding the flaky graphite powder, the spherical aluminum oxide and the carbon fibers into a high-molecular resin matrix, so that the thermal conductivity of the material is remarkably improved. The flaky graphite powder provides a high-heat-conduction channel in a plane, the spherical aluminum oxide fills gaps among graphite flake layers, and the carbon fibers form a penetrating heat-conduction bridge, so that the heat conductivity coefficient of the material can reach 2-10W / (m.K) and is increased by 5-20 times compared with that of a traditional aluminum-plastic plate under the synergistic effect of the three components, and the heat dissipation performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum-plastic panels, and in particular to an aluminum-plastic panel with high heat dissipation and a preparation method thereof. Background Art

[0002] Aluminum-plastic composite panels (APCPs), due to their lightweight, aesthetically pleasing design, and ease of processing, are widely used in architectural curtain walls, interior decoration, and other fields. Traditional ACPs typically consist of two aluminum sheets, top and bottom, bonded to a plastic core layer using an adhesive. However, the low thermal conductivity of the plastic core (typically in the range of 0.1-0.5 W / (m·K)) results in poor overall heat dissipation performance. In some applications requiring rapid heat dissipation, such as electronic device housings and LED lighting heat sinks, conventional ACPs struggle to meet these requirements, limiting their further application. To improve the thermal conductivity of ACPs, existing technologies primarily employ the following approaches: 1. Adding highly thermally conductive fillers, such as metal powder, graphite, and carbon nanotubes, to the plastic core layer. However, high filler loadings can degrade the mechanical properties of the plastic core layer, and uneven filler dispersion can lead to agglomeration, impairing thermal conductivity. 2. Using metal mesh or metal foil as a composite with the plastic core layer increases the complexity and cost of the manufacturing process. 3. A heat dissipation coating is applied on the surface of the aluminum-plastic panel, but the coating is easy to wear and fall off, and its long-term stability is poor. Summary of the Invention

[0003] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an aluminum-plastic panel with high heat dissipation and a preparation method thereof.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: an aluminum-plastic panel with high heat dissipation performance, comprising an upper aluminum alloy layer, an intermediate heat-conducting composite layer, and a lower aluminum alloy layer stacked in sequence; the intermediate heat-conducting composite layer is made of the following raw materials in parts by weight: 100 parts of polymer resin matrix; 30-80 parts of flaky graphite powder; 20-50 parts of spherical alumina; 5-20 parts of carbon fiber; 1-5 parts of coupling agent; 1-3 parts of dispersant; 5-15 parts of plasticizer; 5-10 parts of flame retardant.

[0005] Furthermore, the polymer resin matrix is ​​one of polyethylene, polypropylene, and polyvinyl chloride.

[0006] Furthermore, the particle size of the flaky graphite powder is 5-50 μm, and the purity is ≥98%; the particle size of the spherical alumina is 1-10 μm, and the purity is ≥99%; the length of the carbon fiber is 0.1-5 mm, and the diameter is 5-15 μm.

[0007] Furthermore, the thickness of the upper aluminum alloy layer and the lower aluminum alloy layer is 0.1-1.0 mm, preferably 0.3-0.7 mm; the thickness of the intermediate heat-conducting composite layer is 1-5 mm, preferably 2-4 mm.

[0008] Furthermore, a micro-nano structure layer is provided on the surface of the upper aluminum alloy layer and the lower aluminum alloy layer. The micro-nano structure layer is formed by an anodic oxidation process, and the surface roughness Ra thereof is 0.5-5 μm.

[0009] A method for preparing an aluminum-plastic panel with high heat dissipation, comprising: step S1: performing surface treatment on an aluminum alloy plate, and then forming a micro-nanostructure layer on the surface of the plate by an anodic oxidation process; S2: Melting the polymer resin matrix at 120-180° C., adding flake graphite powder, spherical alumina, carbon fiber, coupling agent, dispersant, plasticizer, and flame retardant in sequence, and stirring in a high-speed blender at a speed of 1000-3000 rpm for 20-60 minutes to obtain a thermally conductive composite layer raw material; S3: placing the pretreated upper aluminum alloy plate, the thermal conductive composite layer raw material, and the lower aluminum alloy plate into a laminator in sequence, pressing them at a temperature of 150-220°C and a pressure of 5-20 MPa for 10-30 minutes, and demolding them after cooling to obtain a high thermal conductive aluminum-plastic composite plate material; Furthermore, the oxidation time of the anodizing process in S1 is 10-30 minutes, the oxidation voltage is 10-25 V, and the thickness of the formed micro-nanostructure layer 4 is 5-20 μm.

[0010] Furthermore, the coupling agent is a silane coupling agent or a titanate coupling agent, the dispersant is zinc stearate or polyethylene wax, the plasticizer is dioctyl phthalate or epoxy soybean oil, and the flame retardant is aluminum hydroxide or melamine.

[0011] Compared with the prior art, the advantages and positive effects of the present invention are: 1. Excellent thermal conductivity. This invention significantly improves the material's thermal conductivity by adding flaky graphite powder, spherical alumina, and carbon fibers to a polymer resin matrix to form a three-dimensional thermal network. The flaky graphite powder provides highly conductive in-plane channels, the spherical alumina fills the interlayer gaps between graphite flakes, and the carbon fibers form penetrating thermal bridges. The synergistic effect of these three factors results in a thermal conductivity of 2-10 W / (m·K), a 5-20 times improvement over traditional aluminum-plastic panels, thereby enhancing heat dissipation performance.

[0012] 2. Excellent mechanical properties. The flaky structure of the flaky graphite powder and the reinforcement of the carbon fibers effectively improve the material's mechanical properties, resulting in both high strength and toughness. Compared to a pure plastic core layer, the intermediate thermally conductive composite layer of this invention boasts a 30-50% increase in tensile strength and a 40-60% increase in flexural strength.

[0013] 3. Strong interface bonding strength. The micro-nano structure layer on the surface of the aluminum alloy plate increases the contact area with the intermediate thermal conductive composite layer. At the same time, the use of coupling agent further enhances the interface bonding strength, making the interlayer peeling strength of the material reach 1.5-3.0N / mm, which is 50-100% higher than that of traditional aluminum-plastic panels.

[0014] 4. Simple process and low cost. The present invention adopts a one-step lamination process, which does not require complex equipment and multiple steps. It has high production efficiency and low cost and is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention proposes a schematic structural diagram of an aluminum-plastic panel with high heat dissipation and a method for preparing the same; Reference numerals: 1, upper aluminum alloy layer; 2, middle heat-conducting composite layer; 3, lower aluminum alloy layer; 4, micro-nanostructure layer. DETAILED DESCRIPTION

[0016] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0017] In the description of the present invention, it should be understood that the terms "length," "width," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and the like, indicating positions or location relationships, are based on the positions or location relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, in the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

[0018] Example 1 See also Figure 1 The present invention provides an aluminum-plastic panel with high heat dissipation performance, comprising an upper aluminum alloy layer, an intermediate heat-conducting composite layer, and a lower aluminum alloy layer stacked in sequence. The intermediate heat-conducting composite layer is made of the following raw materials in parts by weight: 100 parts of polymer resin matrix; 50 parts of flaky graphite powder (particle size 20 μm); 30 parts of spherical alumina (particle size 5 μm); 10 parts of carbon fiber (3 mm in length, 7 μm in diameter); Silane coupling agent KH550 3 parts; 2 parts of zinc stearate dispersant; 10 parts of dioctyl phthalate plasticizer; 8 parts of aluminum hydroxide flame retardant; The upper and lower aluminum alloy layers are both made of 3003 aluminum alloy, with a thickness of 0.5 mm. The surface micro-nanostructure layer has a roughness Ra of 2 μm. The thickness of the middle thermal conductive composite layer is 3 mm.

[0019] The preparation method is as follows: S1: Aluminum alloy plate pretreatment: The 3003 aluminum alloy plate is sequentially subjected to degreasing, alkali washing and pickling treatment; Anodic oxidation was performed in a sulfuric acid electrolyte at an oxidation voltage of 18 V for 20 minutes to form a micro-nanostructure layer with a thickness of about 10 μm. S2: Preparation of raw materials for thermal conductive composite layer: Melt polypropylene at 170°C; Add flaky graphite powder, spherical alumina, carbon fiber, silane coupling agent KH550, zinc stearate dispersant, dioctyl phthalate plasticizer and aluminum hydroxide flame retardant in sequence, and stir in a high-speed mixer at a speed of 2000 rpm for 40 minutes; S3:Lamination composite molding: The pretreated upper aluminum alloy plate, the heat conductive composite layer raw material and the lower aluminum alloy plate are sequentially placed into a laminating machine; Press at a temperature of 190°C and a pressure of 15 MPa for 20 minutes; After cooling to room temperature, the mold is removed to obtain a high thermal conductivity aluminum-plastic composite board material.

[0020] Example 2 The present invention provides an aluminum-plastic panel with high heat dissipation performance, comprising an upper aluminum alloy layer, an intermediate heat-conducting composite layer, and a lower aluminum alloy layer stacked in sequence. The intermediate heat-conducting composite layer is made of the following raw materials in parts by weight: Polyethylene (PE) 100 parts; 60 parts of flaky graphite powder (particle size 30 μm); 25 parts of spherical alumina (particle size 3 μm); 15 parts of carbon fiber (length 1 mm, diameter 10 μm); 4 parts of titanate coupling agent NDZ-201; 2 parts of polyethylene wax dispersant; 12 parts of epoxy soybean oil plasticizer; 7 parts of melamine flame retardant; The upper and lower aluminum alloy layers are both made of 5052 aluminum alloy, with a thickness of 0.4 mm. The surface micro-nanostructure layer has a roughness Ra of 3 μm. The thickness of the middle thermal conductive composite layer is 2.5 mm. The preparation method is similar to that of Example 1, except that: The anodic oxidation voltage was 22 V and the oxidation time was 15 minutes; The lamination temperature was 180°C, the pressure was 12 MPa, and the pressing time was 25 min; Comparative Example A conventional aluminum-plastic composite panel was used as a comparative example, wherein the middle core layer was pure polyethylene, and the thickness of the upper and lower aluminum alloy layers was the same as that of Example 1; Performance Testing The performance tests of the aluminum-plastic composite panels of Example 1, Example 2 and the comparative example were carried out respectively, and the test results are shown in the following table:

[0021] It can be seen from the test results that the aluminum-plastic panel with high heat dissipation of the present invention is significantly superior to the traditional aluminum-plastic composite panel in terms of thermal conductivity, mechanical properties and interlayer bonding strength.

[0022] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other form. Any person skilled in the art may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes for application in other fields. However, any simple modification, equivalent change and modification of the above embodiments made in accordance with the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. An aluminum-plastic panel with high heat dissipation, characterized by: The invention comprises an upper aluminum alloy layer (1), an intermediate heat-conducting composite layer (2), and a lower aluminum alloy layer (3) which are stacked in sequence; the intermediate heat-conducting composite layer (2) is made of the following raw materials in parts by weight: 100 parts of polymer resin matrix; 30-80 parts of flaky graphite powder; 20-50 parts of spherical alumina; 5-20 parts of carbon fiber; 1-5 parts of coupling agent; 1-3 parts of dispersant; 5-15 parts of plasticizer; 5-10 parts of flame retardant.

2. The aluminum-plastic panel with high heat dissipation according to claim 1, characterized in that: The polymer resin matrix is ​​one of polyethylene, polypropylene and polyvinyl chloride.

3. The aluminum-plastic panel with high heat dissipation according to claim 1, characterized in that: The particle size of the flaky graphite powder is 5-50 μm, and the purity is ≥98%; the particle size of the spherical alumina is 1-10 μm, and the purity is ≥99%; the length of the carbon fiber is 0.1-5 mm, and the diameter is 5-15 μm.

4. The aluminum-plastic panel with high heat dissipation according to claim 1, characterized in that: The thickness of the upper aluminum alloy layer (1) and the lower aluminum alloy layer (3) is 0.1-1.0 mm, preferably 0.3-0.7 mm; the thickness of the intermediate heat-conducting composite layer (2) is 1-5 mm, preferably 2-4 mm.

5. The aluminum-plastic panel with high heat dissipation according to claim 1, characterized in that: The surfaces of the upper aluminum alloy layer (1) and the lower aluminum alloy layer (3) are both provided with a micro-nano structure layer (4), and the micro-nano structure layer (4) is formed by an anodic oxidation process, and its surface roughness Ra is 0.5-5 μm.

6. A method for preparing an aluminum-plastic panel with high heat dissipation according to claims 1 to 5, characterized in that: S1: After the aluminum alloy plate is subjected to surface treatment, a micro-nanostructure layer (4) is formed on the surface of the aluminum alloy plate through an anodic oxidation process; S2: Melting the polymer resin matrix at 120-180° C., adding flake graphite powder, spherical alumina, carbon fiber, coupling agent, dispersant, plasticizer, and flame retardant in sequence, and stirring in a high-speed blender at a speed of 1000-3000 rpm for 20-60 minutes to obtain a thermally conductive composite layer raw material; S3: The pretreated upper aluminum alloy plate (1), the heat-conducting composite layer raw material and the lower aluminum alloy plate (3) are sequentially placed in a laminating machine, pressed at a temperature of 150-220° C. and a pressure of 5-20 MPa for 10-30 minutes, and demolded after cooling to obtain a high-thermal-conductivity aluminum-plastic composite plate material.

7. The method for preparing an aluminum-plastic panel with high heat dissipation according to claim 6, wherein: The oxidation time of the anodizing process in S1 is 10-30 minutes, the oxidation voltage is 10-25V, and the thickness of the formed micro-nanostructure layer (4) is 5-20 μm.

8. The method for preparing an aluminum-plastic panel with high heat dissipation according to claim 6, wherein: The coupling agent is a silane coupling agent or a titanate coupling agent, the dispersant is zinc stearate or polyethylene wax, the plasticizer is dioctyl phthalate or epoxy soybean oil, and the flame retardant is aluminum hydroxide or melamine.

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