Photovoltaic frame aluminum alloy profile and preparation method thereof

Abstract

The invention provides a photovoltaic frame aluminum alloy profile and a preparation method thereof, and relates to the technical field of aluminum alloy profile preparation. The preparation method of the photovoltaic frame aluminum alloy profile comprises the following steps that an aluminum alloy base material is provided, the aluminum alloy base material is pretreated, the surface of the pretreated aluminum alloy base material is coated with bottom layer slurry to obtain a prime-coated aluminum alloy base material, and the surface of the prime-coated aluminum alloy base material is coated with surface layer slurry to obtain the photovoltaic frame aluminum alloy profile. The coating layer of the prepared photovoltaic frame aluminum alloy profile has high binding force with the base material, and the weather resistance is excellent.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy profile manufacturing technology, specifically to a photovoltaic frame aluminum alloy profile and its manufacturing method. Background Technology

[0002] Aluminum alloy photovoltaic (PV) frame profiles are made primarily of aluminum through specific processing techniques. With the global emphasis on renewable energy, photovoltaic (PV) power generation technology has developed rapidly. As a crucial component of PV modules, the PV frame's main function is to fix and seal the modules, protect the cells, glass, backsheet, and other materials, enhance the overall strength of the module, and facilitate transportation, installation, and long-term use. Its performance has a vital impact on the module's lifespan and stability. Among various PV frame materials, aluminum alloy frames are currently the most widely used due to their lightweight, high strength, ease of processing, and recyclability.

[0003] Weather resistance is a crucial performance characteristic of aluminum alloy profiles for photovoltaic frames. Ultraviolet rays in sunlight are the main culprit for the aging and fading of these profiles. Applying a weather-resistant coating to the aluminum alloy surface can effectively reflect and absorb ultraviolet rays, thus maintaining vibrant colors for a long period and preventing significant fading, loss of gloss, or discoloration. However, the adhesion between the weather-resistant coating and the aluminum alloy substrate is relatively weak, causing the coating to peel off during use and reducing the weather resistance of the photovoltaic frame aluminum alloy profile. Therefore, providing a photovoltaic frame aluminum alloy profile with excellent weather resistance has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a photovoltaic frame aluminum alloy profile and its preparation method, solving the technical problem of weak adhesion between the coating and the surface of the aluminum alloy substrate.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] On one hand, the present invention provides a method for preparing an aluminum alloy profile for a photovoltaic frame, comprising the following steps:

[0009] An aluminum alloy substrate is provided, the aluminum alloy substrate is pretreated, a base layer slurry is coated on the surface of the pretreated aluminum alloy substrate to obtain a base-coated aluminum alloy substrate, and a top layer slurry is coated on the surface of the base-coated aluminum alloy substrate to obtain a photovoltaic frame aluminum alloy profile.

[0010] Preferably, the underlying slurry includes a leveling agent, a defoamer, and an adhesion promoter;

[0011] The leveling agent is polyether-modified polydimethylsiloxane;

[0012] The defoamer is a polyether-modified siloxane;

[0013] The adhesion promoter is a phosphate ester promoter.

[0014] Preferably, the mass ratio of the leveling agent, defoamer, and adhesion promoter is 0.4-1:0.2-0.5:0.05-0.2.

[0015] Preferably, the underlying slurry further includes hydroxyl acrylic resin, and the mass ratio of the hydroxyl acrylic resin to the leveling agent is 100:0.4-0.6.

[0016] Preferably, the pretreatment is a chromium-free conversion treatment.

[0017] Preferably, the surface slurry is a fluorine-containing material.

[0018] Preferably, the surface layer slurry comprises fluoropolymer resin and acrylic resin, wherein the mass ratio of the fluoropolymer resin to the acrylic resin is 20-30:10-20.

[0019] On the other hand, the present invention provides a photovoltaic frame aluminum alloy profile prepared by the preparation method described in the first aspect, the photovoltaic frame aluminum alloy profile comprising an aluminum alloy substrate, a base coating layer on the surface of the aluminum alloy substrate, and a surface layer on the surface of the base coating layer.

[0020] (III) Beneficial Effects

[0021] This invention provides an aluminum alloy profile for photovoltaic frames and its preparation method. Compared with the prior art, it has the following advantages:

[0022] The preparation method of photovoltaic frame aluminum alloy profiles includes coating a base layer slurry onto the surface of a pretreated aluminum alloy substrate. The base layer slurry includes a leveling agent, a defoamer, and an adhesion promoter, selected from hydroxyl acrylic resin as the main resin. When the mass ratio of the leveling agent, defoamer, and adhesion promoter is 0.4-1:0.2-0.5:0.05-0.2, the defoamer, leveling agent, and adhesion promoter have a synergistic effect in improving the adhesion between the base layer and the surface of the aluminum alloy substrate, thereby improving the adhesion between the coating layer and the substrate of the prepared photovoltaic frame aluminum alloy profile. The surface layer contains polyvinylidene fluoride (PVDF). The fluorocarbon bond (FC) bond energy of PVDF is extremely high, which endows the surface layer coating with chemical inertness and light stability, resisting ultraviolet radiation and chemical corrosion. Therefore, the prepared photovoltaic frame aluminum alloy profiles always have excellent weather resistance during use. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with specific implementation methods.

[0025] Example 1

[0026] This embodiment provides a method for preparing an aluminum alloy profile for a photovoltaic frame, including the following steps:

[0027] S1. Al ingots are added to a melting furnace and heated to 720℃ to melt. Al-Si, Al-Mn, Al-Cr, Al-Fe, Al-Ti, and Al-Zn master alloys, as well as Cu and Mg ingots, are then added to the furnace and melted to obtain an aluminum alloy melt. After rapid sampling and analysis of the aluminum alloy melt, metal elements are added to adjust the chemical composition of the target aluminum alloy profile to Si 0.82%, Mn 0.04%, Cr 0.03%, Fe 0.3%, Ti 0.04%, Zn 0.01%, Cu 0.05%, Mg 0.9%, and Al as the balance. After slag removal and heating, the aluminum alloy liquid is obtained. Nitrogen is used for refining in a settling furnace, with the refining temperature controlled at 725℃ and the refining time at 0.4 hours. The aluminum alloy liquid is then cast, and after casting, it undergoes homogenization treatment. The casting speed is 110 mm / min, and the cooling water flow rate is 100 m³ / min. 3 The homogenization process is as follows: first, the temperature is raised from 40℃ / h to 450℃ and held for 2 hours; then, the temperature is raised to 550℃ at 220℃ / h and held for 1.5 hours; then, it is cooled to 220℃ by strong air cooling; finally, it is cooled to room temperature by cooling water spray to obtain an aluminum alloy billet. This billet is then sent to an aging furnace for aging treatment: the temperature is raised to 185℃ at a rate of 100℃ / h and held for 5 hours. After removal, it is cooled to below 40℃ by strong air cooling at a rate of 120℃ / h, and then anodized to obtain the aluminum alloy substrate.

[0028] S2. Immerse the aluminum alloy substrate in Henkel Bonderite C-AK metal cleaner at 45°C for 10 minutes, then rinse with tap water. Next, add deionized water to a clean tank, and under stirring, add Kemet's chromium-free conversion treatment concentrate (volume ratio of chromium-free conversion treatment concentrate to deionized water: 5:100). After stirring evenly, adjust the pH to 4.2 with sodium hydroxide solution, immerse the aluminum alloy substrate at 35°C for 2 minutes, remove and rinse with deionized water, then dry at 80°C for 10 minutes to obtain the pretreated aluminum alloy substrate.

[0029] S3. Mix 100 parts of hydroxyl acrylic resin (Asahi Kasei Arakyd® 5061), 0.5 parts of leveling agent polyether modified polydimethylsiloxane BYK-306, 0.3 parts of defoamer polyether modified siloxane BYK-077, 0.1 parts of adhesion promoter phosphate ester BYK-P104, and 30 parts of solvent ethyl acetate evenly. Slowly add 10 parts of isophorone diisocyanate while stirring continuously. Add diluent butyl acetate and adjust the viscosity to 25 seconds (25°C) as measured by a Fork-4 cup. Let stand for 10 minutes to obtain the primer solution. The primer solution was sprayed onto the pretreated aluminum alloy substrate surface in a "cross" pattern under the conditions of spraying air pressure of 0.4MPa, gun distance of 15cm, and gun speed of 30cm / s. Two coats were sprayed, and the substrate was allowed to level naturally for 15 minutes. It was then dried at 140℃ for 15 minutes and allowed to cool naturally to room temperature to obtain the aluminum alloy substrate with primer coating. The dry film thickness of the primer coating was 25μm.

[0030] S4. Disperse 0.3 parts of acrylate leveling agent BYK-358N and dispersant BYK-163 into 20 parts of propylene glycol methyl ether acetate, then add 25 parts of polyvinylidene fluoride resin, 10 parts of acrylic resin, 10 parts of rutile titanium dioxide, and 30 parts of diacetone alcohol. Mix well, add diacetone alcohol as a diluent, and adjust the viscosity to 18 seconds (25℃) measured by a Forecast-4 cup. After filtering through a 150-mesh filter, let stand for 10 minutes, and then perform electrostatic spraying under 60kV (negative) high voltage electrostatic conditions. The forming air flow rate is 200L / min, the paint flow rate is 200mL / min, the spray gun distance is 20cm, and the spray gun moving speed is 0.5m / s. Apply two coats to the aluminum alloy substrate surface after the primer using a "cross" spraying method. Allow it to level naturally for 15 minutes, dry at 250℃ for 15 minutes, and then cool naturally to room temperature to obtain the photovoltaic frame aluminum alloy profile. The dry film thickness of this layer is 35μm.

[0031] Examples 2 and 3

[0032] The difference between Examples 2 and 3 and Example 1 is that the amount of each raw material used in S3 is different, as detailed in Table 1. The rest is the same as in Example 1.

[0033] Comparative Example 1

[0034] The difference between this comparative example and Example 1 is that S3 does not include defoamer. Other specific dosages are shown in Table 1, and the rest is the same as in Example 1.

[0035] Comparative Example 2

[0036] The difference between this comparative example and Example 1 is that leveling agent is not included in S3. Other specific dosages are shown in Table 1, and the rest is the same as in Example 1.

[0037] Comparative Example 3

[0038] The difference between this comparative example and Example 1 is that S3 does not include an adhesion promoter. Other specific dosages are shown in Table 1, and the rest is the same as in Example 1.

[0039] Table 1. Amounts of each raw material used in step S3 of the examples and comparative examples.

[0040]

[0041] II. Testing Methods

[0042] Coating adhesion: The adhesion between the coating and the aluminum alloy substrate was tested according to the ASTM D3359 cross-cut test.

[0043] III. Test Results

[0044] The bonding strength test results between the surface coating layer and the substrate of the photovoltaic frame aluminum alloy profiles prepared in Examples 1-3 and Comparative Examples 1-3 are detailed in Table 2.

[0045] Table 2. Performance test results of the photovoltaic frame aluminum alloy profiles prepared in the examples and comparative examples.

[0046]

[0047] As shown in Table 2, the surface coating of the photovoltaic frame aluminum alloy profiles prepared in Examples 1-3 achieved a 5B level of adhesion to the substrate, with completely smooth cut edges and no peeling of the grid-like coating. However, the surface coating of the photovoltaic frame aluminum alloy profiles prepared in Comparative Examples 1-3, lacking any of the defoamer, leveling agent, or adhesion promoter, only achieved a 2B-3B level of adhesion to the substrate. This is because the synergistic effect of the defoamer, leveling agent, and adhesion promoter improved the adhesion between the base coating and the aluminum alloy substrate surface, thereby enhancing the adhesion between the coating and the substrate of the prepared photovoltaic frame aluminum alloy profile. Therefore, the prepared photovoltaic frame aluminum alloy profiles exhibit excellent weather resistance during use.

[0048] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0050] The present invention has been illustrated with the above embodiments to describe the detailed process flow of the present invention. However, the present invention is not limited to the above detailed process flow, that is, it does not mean that the present invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing an aluminum alloy profile for photovoltaic frames, characterized in that, Includes the following steps: An aluminum alloy substrate is provided, the aluminum alloy substrate is pretreated, a base layer slurry is coated on the surface of the pretreated aluminum alloy substrate to obtain a base-coated aluminum alloy substrate, and a top layer slurry is coated on the surface of the base-coated aluminum alloy substrate to obtain a photovoltaic frame aluminum alloy profile.

2. The method for preparing the photovoltaic frame aluminum alloy profile as described in claim 1, characterized in that, The underlying slurry includes leveling agent, defoamer, and adhesion promoter; The leveling agent is polyether-modified polydimethylsiloxane; The defoamer is a polyether-modified siloxane; The adhesion promoter is a phosphate ester promoter.

3. The method for preparing the photovoltaic frame aluminum alloy profile as described in claim 2, characterized in that, The mass ratio of the leveling agent, defoamer, and adhesion promoter is 0.4-1:0.2-0.5:0.05-0.

2.

4. The method for preparing the photovoltaic frame aluminum alloy profile as described in claim 2, characterized in that, The underlying slurry also includes hydroxyl acrylic resin, and the mass ratio of the hydroxyl acrylic resin to the leveling agent is 100:0.4-0.

6.

5. The method for preparing the photovoltaic frame aluminum alloy profile as described in claim 1, characterized in that, The pretreatment is a chromium-free conversion treatment.

6. The method for preparing the photovoltaic frame aluminum alloy profile as described in claim 1, characterized in that, The surface layer slurry is a fluorine-containing material.

7. The method for preparing the photovoltaic frame aluminum alloy profile as described in claim 1, characterized in that, The surface layer slurry includes fluoropolymer resin and acrylic resin, and the mass ratio of the fluoropolymer resin to the acrylic resin is 20-30:10-20.

8. A photovoltaic frame aluminum alloy profile prepared by the preparation method according to any one of claims 1-7, characterized in that, The photovoltaic frame aluminum alloy profile includes an aluminum alloy substrate, a base coating layer on the surface of the aluminum alloy substrate, and a surface layer on the surface of the base coating layer.

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