Photovoltaic module composite film, preparation method thereof and photovoltaic module

Abstract

The invention provides a photovoltaic module composite film, a preparation method thereof and a photovoltaic module. The photovoltaic module composite film comprises a base material and coating layers located on the surfaces of the two sides of the base material, and a bonding layer is arranged on the face, opposite to the base material, of one coating layer. The coating layer is prepared from the following materials: resin, coloring pigment, a dispersing aid, a curing agent and a catalyst; all the coating layers are white coatings or all the coating layers are black coatings; the thickness of the coating layer and the mass percentage content of the coloring pigment in the coating layer are in a negative correlation. The photovoltaic module composite film provided by the invention can be applied to photovoltaic cell assembly of a white or black back plate, is arranged between cell pieces and is used for covering a welding strip, so that the covered whole module looks uniform in color and attractive in appearance, and the requirement of building integrated photovoltaics is better met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic materials, in particular to a photovoltaic module composite film, a preparation method thereof and a photovoltaic module. BACKGROUND

[0002] Since the mass production of PERC cells in 2015, the efficiency has approached the theoretical limit, and IBC, HBC and TBC back contact cells are considered as the next generation direction. At the component end, the effective light receiving area can be improved by reducing the cell spacing. In theory, the smaller the cell arrangement gap, the larger the effective light receiving area, and the component power can be correspondingly improved. However, if the gap is too low, it may lead to a significant increase in the buckling stress of the solder strip, the difference in thermal expansion of the cell, and the risk of cell combination during lamination. The probability of hidden cracks and short circuits increases exponentially. In addition, the solder strip bending and yield strength limit the further compression of the gap.

[0003] At the same time, the building integrated photovoltaic (BIPV) requires the appearance of the component to be consistent with the building materials. The existing copper-based solder strip and its surface tin-based alloy are metal reflective under visible light, and the color difference of the back plate, bus bar and solder joint is obvious, which presents obvious metal luster under natural light and building lighting, and has large color difference with the surrounding building materials, which destroys the overall appearance consistency.

[0004] At present, during the preparation of the component, an insulating strip with a specific width is placed between the cells to cover the solder strip, but the covering force is insufficient, and the visual effect is still affected. SUMMARY

[0005] The main purpose of the present application is to provide a photovoltaic module composite film, a preparation method thereof and a photovoltaic module, so as to solve the problem of insufficient covering capacity of the photovoltaic module composite film in the prior art.

[0006] In order to achieve the above purpose, according to one aspect of the present application, a photovoltaic module composite film is provided, which comprises a substrate and a coating layer located on both sides of the substrate, and an adhesive layer is arranged on the side of one of the coating layers opposite to the substrate; the material of the coating layer comprises resin, coloring pigment, dispersion aid, curing agent and catalyst; the coating layer is all white coating or all black coating; the thickness of the coating layer and the mass percentage content of the coloring pigment in the coating layer are in a negative correlation.

[0007] Further, when the coating layer is a white coating layer, the white pigment has a D90 particle size of D1, in units of μm, 0.1≤D1≤0.8, and D1 satisfies the formula k2=M1×D1; wherein k2 is a constant, and when 0.1≤D1≤0.3, k2 is 2-12, and when 0.3

[0008] Further, when the coating layer is a white coating layer, the white pigment has a D90 particle size of D1, in units of μm, 0.1≤D1≤0.8, and D1 satisfies the formula k2=M1×D1; wherein k2 is a constant, and when 0.1≤D1≤0.3, k2 is 2-12, and when 0.3

[0009] Further, when the coating layer is a white coating layer, the white coating layer has a color value of L1, 85≤L1≤95, and L1 satisfies the formula k3=L1×D1×A / (M1×H1); wherein A is the yellowness value of the substrate, A is 10-30; k3 is a constant, and when 85≤L1<90, k3 is 2.00-2.30, and when 90≤L1≤95, k3 is 2.20-2.50; or when the coating layer is a black coating layer, the black coating layer has a color value of L2, 20≤L2≤25, and L2 satisfies k6=L2×D2×A / (M2×H2), wherein A is the yellowness value of the substrate, A is 10-30; k6 is a constant, and when 20≤L2≤23, k6 is 15-35, and when 23

[0010] Further, M1 is 10-40; and / or, M2 is 10-40.

[0011] Further, the white pigment is any one or more of titanium white, talc, calcium carbonate, and barium sulfate; and the black pigment is any one or more of carbon black, titanium black, manganese iron black, and copper chromium black.

[0012] Furthermore, the substrate material is any one or more of polyimide, polyethylene terephthalate, and polyethylene naphthalate; and / or, the substrate thickness is 15~35μm; and / or, the adhesive layer material is any one or more of ethylene-vinyl acetate copolymer, polyolefin elastomer, polyethylene, and polyurethane; and / or, the adhesive layer thickness is 40~60μm.

[0013] According to another aspect of the present invention, a method for preparing the above-mentioned photovoltaic module composite film is provided. The method includes: mixing raw materials including a coating layer material and a solvent and then milling them to obtain a coating slurry; applying the coating slurry to both sides of a substrate and drying it to form a coating layer; and providing an adhesive layer on one side of one of the coating layers opposite to the substrate.

[0014] Furthermore, the drying temperature is 150~180℃, and the drying time is 2~10min.

[0015] According to another aspect of the present invention, a photovoltaic module is provided, comprising solar cells, a backsheet, and a composite film disposed between the solar cells, wherein the composite film is the photovoltaic module composite film described above or prepared by the preparation method described above.

[0016] Applying the technical solution of this invention, this application discovers that the thickness of the coating layer and the content of coloring pigments in the coating layer have a significant impact on the color of the coating. When photovoltaic module composite films are applied to photovoltaic cell assemblies with white or black backsheets and placed between the cells to cover solder ribbons, controlling the coating layer thickness and the mass percentage of coloring pigments in the coating layer to be negatively correlated can improve the hiding power of the photovoltaic module composite film. This results in a more uniform color and aesthetically pleasing overall module after covering, thus better meeting the requirements of building-integrated photovoltaics (BIPV). Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A schematic diagram of the structure of a photovoltaic module composite film according to an embodiment of the present invention is shown; and

[0019] The above figures include the following reference numerals: 01, coating layer; 02, substrate; 03, adhesive layer. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] As analyzed in the background section of this application, there is a problem of insufficient shading capacity of photovoltaic module composite films in the prior art. In order to solve this problem, this application provides a photovoltaic module composite film, its preparation method, and a photovoltaic module.

[0022] According to a typical embodiment of this application, a photovoltaic module composite film is provided, such as... Figure 1 As shown, the photovoltaic module composite film includes a substrate 02 and coating layers 01 located on both sides of the substrate 02, and an adhesive layer 03 is provided on one of the coating layers 01 opposite to the substrate 02; wherein, the materials of the coating layer 01 include: resin, coloring pigment, dispersant, curing agent and catalyst; the coating layer 01 is entirely white coating or entirely black coating; the thickness of the coating layer and the mass percentage of coloring pigment in the coating layer are negatively correlated.

[0023] This application discovers that the thickness of coating layer 01 and the content of coloring pigment in coating layer 01 have a significant impact on the color of the coating. When photovoltaic module composite films are used in the assembly of photovoltaic cells on white or black backsheets and placed between the cells to cover the solder ribbons, controlling the thickness of the coating layer and the mass percentage content of coloring pigment in the coating layer are negatively correlated. This can improve the hiding power of the photovoltaic module composite film, making the overall module appear uniform in color and aesthetically pleasing after covering, thereby better meeting the requirements of building-integrated photovoltaics.

[0024] In this application, the negative correlation between the thickness of the coating layer and the mass percentage of the coloring pigment in the coating layer means that as the coating layer thickness increases, the mass percentage of the coloring pigment in the coating layer decreases accordingly, so as to ensure a balance between the hiding power and processing performance of the coating layer. When the coating layer is white, this negative correlation is specifically expressed as k1=M1×H1, where k1 is a constant, and when 1≤H1<10, k1 is 100~250, and when 10≤H1≤20, k1 is 150~400; when the coating layer is black, this negative correlation is specifically expressed as k4=M2×H2, where k4 is a constant, and when 1≤H2<8, k4 is 50~200, and when 8≤H2≤15, k4 is 150~350.

[0025] In some embodiments of this application, when the coating layer is a white coating, the coloring pigment is a white pigment, the thickness of the coating layer is H1 in μm, 1≤H1≤20, and the mass percentage of the coloring pigment in the coating layer is M1 in %. H1 and M1 satisfy the formula k1=M1×H1; where k1 is a constant, and when 1≤H1<10, k1 is 100~250, and when 10≤H1≤20, k1 is 150~400; or, when the coating layer is a black coating, the coloring pigment is a black pigment, the thickness of the coating layer is H2 in μm, 1≤H2≤15, and the mass percentage of the coloring pigment in the coating layer is M2 in %. H2 and M2 satisfy the formula k4=M2×H2; where k4 is a constant, and when 1≤H2<8, k4 is 50~200, and when 8≤H2≤15, k4 is 150~350.

[0026] When coating layer 01 is white, and the thickness of coating layer 01 and the white pigment satisfy the above formula and the corresponding ranges of k1 and H1, the photovoltaic module composite film appears white. This composite film is applied to the photovoltaic cell assembly on a white backsheet, placed between the cells to cover the solder ribbons. After covering, the overall module appears uniform in color and aesthetically pleasing. Similarly, when coating layer 01 is black, the photovoltaic module composite film appears black. When the thickness of coating layer 01 and the black pigment satisfy the above formula and the corresponding ranges of k4 and H2, the black photovoltaic module composite film is applied to the photovoltaic cell assembly on a black backsheet, making the overall module visually uniform in color and aesthetically pleasing after covering.

[0027] Understandably, when coating layer 01 is a white coating, the thickness of coating layer 01 can be 1μm, 3μm, 5μm, 7μm, 9μm, 11μm, 13μm, 15μm, 17μm, 19μm, 20μm, etc. When 1≤H1<10 (e.g., 1, 3, 5, 7, 9, etc.), k1 is any value in the range of 100~250, specifically, the value of k1 can be 100, 120, 150, 170, 200, 220, 250, etc.; when 10≤H1≤20 (e.g., 10, 12, 14, 16, 18, 20, etc.), k1 is any value in the range of 150~400, specifically, the value of k1 can be 150, 170, 200, 220, 250, 270, 300, 320, 350, 370, 400, etc. Preferably, the thickness of coating layer 01 is 10~20μm.

[0028] Understandably, when coating layer 01 is a black coating, the thickness H2μm of coating layer 01 can specifically be 1μm, 3μm, 5μm, 7μm, 9μm, 11μm, 13μm, 15μm, etc. When 1≤H2<8 (e.g., 1, 2, 3, 4, 5, 6, 7, etc.), k4 is any value in the range of 50~200, specifically, the value of k4 can be 50, 80, 100, 120, 150, 170, 200, etc. When 8≤H1≤15 (e.g., 8, 9, 11, 13, 15, etc.), k4 is any value in the range of 150~350, specifically, the value of k4 can be 150, 170, 200, 220, 250, 270, 300, 320, 350, etc. Preferably, the thickness of coating layer 01 is 5~7μm.

[0029] Understandably, the thickness of the two coating layers 01 on both sides of the substrate 02 of the photovoltaic module composite film of this application can satisfy the above formula, and the thickness of the two coating layers 01 is the same.

[0030] In some embodiments of this application, when the coating layer is a white coating, the D90 particle size of the white pigment is D1, in μm, 0.1≤D1≤0.8, and D1 satisfies the formula k2=M1×D1; where k2 is a constant, and when 0.1≤D1≤0.3, k2 is 2~12, and when 0.3<D1≤0.8, k2 is 7~40; or, when the coating layer is a black coating, the D90 particle size of the black pigment is D2, in μm, 1≤D2≤20, and D2 and M2 satisfy the formula k5=M2×D2; where k5 is a constant, and when 1≤D2<10, k5 is 100~300, and when 10≤D2≤20, k5 is 150~500.

[0031] This application also found that the particle size and content of the coloring pigment in coating layer 01 have a certain influence on the color of the coating. When coating layer 01 is a white coating, it is preferable that the D90 particle size of the white pigment and the content of the coloring pigment in coating layer 01 satisfy the above formula and the corresponding ranges of k2 and D1. The photovoltaic module composite film appears white, which helps to further improve the coverage and overall performance of the white photovoltaic module composite film. Similarly, when coating layer 01 is a black coating, it is preferable that the D90 particle size of the black pigment and the content of the coloring pigment in coating layer 01 satisfy the above formula and the corresponding ranges of k4 and D1. The photovoltaic module composite film appears black, which helps to further improve the coverage and overall performance of the black photovoltaic module composite film.

[0032] In addition, when the coating layer 01 is a white coating, when 0.1 ≤ D1 ≤ 0.3 (such as 0.1, 0.15, 0.2, 0.25, 0.3, etc.), k2 is any value within the range of 2 to 12, such as k2 is 2, 4, 6, 8, 10, 12, etc. When 0.3 < D1 ≤ 0.8 (such as 0.4, 0.5, 0.6, 0.7, 0.8, etc.), k2 is any value within the range of 7 to 40, such as 7, 10, 15, 20, 25, 30, 35, 40, etc.

[0033] When the coating layer 01 is a black coating, when 1 ≤ D2 < 10 (such as 1, 3, 5, 7, 9, etc.), k5 is any value within the range of 100 to 300, such as k5 is 100, 120, 150, 170, 200, 220, 250, 270, 300, etc. When 10 ≤ D2 ≤ 20 (such as 10, 12, 14, 16, 18, 20, etc.), k5 is any value within the range of 150 to 500, such as 150, 200, 250, 300, 350, 400, 450, 500, etc.

[0034] In some embodiments of the present application, when the coating layer is a white coating, the color value of the white coating is L1, 85 ≤ L1 ≤ 95, and L1 satisfies the formula k3 = L1 × D1 × A / (M1 × H1); where A is the yellowness value of the substrate, A is 10 to 30; k3 is a constant, and when 85 ≤ L1 < 90, k3 is 2.00 to 2.30, when 90 ≤ L1 ≤ 95, k3 is 2.20 to 2.50; or, when the coating layer is a black coating, the color value of the black coating is L2, 20 ≤ L2 ≤ 25, and L2 satisfies k6 = L2 × D2 × A / (M2 × H2), where A is the yellowness value of the substrate, A is 10 to 30; k6 is a constant, and when 20 ≤ L2 ≤ 23, k6 is 15 to 35, when 23 < L2 ≤ 25, k6 is 10 to 30.

[0035] The yellowness of the substrate 02 also affects the color of the photovoltaic module composite film. When the coating layer 01 is a white coating, preferably when L1 satisfies the above formula and the corresponding ranges of A, k3, and L1, it helps to improve the covering effect of the white photovoltaic module composite film and makes the appearance more beautiful. When the coating layer 01 is a black coating, preferably when L2 satisfies the above formula and the corresponding ranges of A, k6, and L2, it helps to improve the covering effect of the black photovoltaic module composite film and makes the appearance more beautiful.

[0036] Furthermore, when coating layer 01 is a white coating, if 85 ≤ L1 < 90 (e.g., 85, 86, 87, 88, etc.), k3 can be any value within the range of 2.00 to 2.30, such as 2.00, 2.10, 2.20, 2.30, etc. If 90 ≤ L1 ≤ 95 (e.g., 90, 92, 94, 95, etc.), k3 can be any value within the range of 2.20 to 2.50, such as 2.20, 2.30, 2.40, 2.50, etc. A can be 10, 12, 15, 17, 20, 22, 25, 27, 30, etc.

[0037] When coating layer 01 is a black coating, and 20 ≤ L2 ≤ 23 (e.g., 20, 21, 22, 23, etc.), k6 can be any value within the range of 15 to 35, such as k6 being 15, 18, 20, 22, 25, 30, 32, 35, etc. When 23 < L2 ≤ 25 (e.g., 24, 25, etc.), k6 can be any value within the range of 10 to 30, such as 10, 12, 15, 17, 20, 22, 25, 27, 30, etc. A can be 10, 12, 15, 17, 20, 22, 25, 27, 30, etc.

[0038] In some embodiments of this application, M1 is 10 to 40; and / or, M2 is 10 to 40.

[0039] When the coating layer is white, it is preferable to control the mass percentage content M1 of the coloring pigment in the coating layer within the above-mentioned range, which helps to further improve the opacity of the white photovoltaic module composite film, thereby enhancing its appearance. When the coating layer is black, it is preferable to control the mass percentage content M2 of the coloring pigment in the coating layer within the above-mentioned range, which helps to improve the opacity of the black photovoltaic module composite film, thereby enhancing its appearance.

[0040] In some embodiments of this application, the white pigment is any one or more of titanium dioxide, talc, calcium carbonate, and barium sulfate, which not only has good covering effect but also good compatibility with resin, thus improving the weather resistance of photovoltaic module composite film.

[0041] In some embodiments of this application, the black pigment is any one or more of carbon black, titanium black, manganese iron black and copper chromium black, which has a good covering effect and is beneficial to improving the peel strength and other properties of the material.

[0042] The resin in coating layer 01 can be selected from existing technologies. This application does not have any special requirements. For example, the resin is selected from any one or more of fluorocarbon resin, acrylic resin, polyester resin, and epoxy resin.

[0043] The dispersing agents, curing agents, catalysts, and other additives in the coating layer 01 material can be selected from existing technologies, and this application does not impose any limitations. For example, the dispersing agent is selected from any one or more of ionic dispersants, nonionic dispersants, amphoteric dispersants, and polymeric dispersants; the curing agent includes, but is not limited to, any one or more of polyurethane curing agents, isocyanate curing agents, and epoxy curing agents; the catalyst includes, but is not limited to, any one or more of amine catalysts, tin catalysts, bismuth catalysts, zinc catalysts, and zirconium catalysts.

[0044] To further improve the shielding power and overall performance of the photovoltaic module composite film, in some embodiments of this application, the material of the substrate 02 is any one or more of polyimide, polyethylene terephthalate (PET), and polyethylene naphthalate (PEN), preferably, the thickness of the substrate 02 is 15~35μm; and / or, the material of the adhesive layer 03 is any one or more of ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), polyethylene (PE), and polyurethane (PU); and / or, the thickness of the adhesive layer 03 is 40~60μm.

[0045] According to another typical embodiment of this application, a method for preparing the above-mentioned photovoltaic module composite film is provided. The method includes: mixing raw materials including a coating layer 01 and a solvent and then milling them to obtain a coating slurry; applying the coating slurry to both sides of a substrate 02 and drying it to form a coating layer 01; and providing an adhesive layer 03 on one side of the coating layer opposite to the substrate.

[0046] The photovoltaic module composite film prepared by the above preparation method can be white or black by controlling the coating thickness and the proportion of coloring material. When applied to photovoltaic cells with backsheets of corresponding colors, the overall module can be visually uniform in color and have an aesthetically pleasing appearance after being covered.

[0047] In order to better form the coating layer, in some embodiments of this application, the drying temperature is 150~180°C and the drying time is 2~10 min.

[0048] According to another typical embodiment of this application, a photovoltaic module is provided, including solar cells, a backsheet, and a composite film disposed between the solar cells. The composite film is the photovoltaic module composite film described above or prepared by the preparation method described above.

[0049] The photovoltaic module of this application uses the aforementioned photovoltaic module composite film, which can effectively cover the bonding wire metal strips, etc., and its color is close to that of the back sheet, with no obvious color difference to the naked eye, making it more aesthetically pleasing overall.

[0050] In some embodiments of this application, the photovoltaic module includes a front glass layer, a front encapsulating film, solar cells, a rear encapsulating film, and a backsheet arranged sequentially. The photovoltaic module composite film is located between the solar cells, and the adhesive layer of the photovoltaic module composite film can face either the front film or the solar cells. When the adhesive layer of the photovoltaic module composite film faces the front encapsulating film, the adhesive layer adheres to the front encapsulating film with high bonding strength and is not easily delaminated. When the adhesive layer of the photovoltaic module composite film faces the solar cells, the adhesive layer can adhere the composite film to the solar cells and also effectively fix the composite film.

[0051] In some embodiments of this application, the backsheet is white, and the coating layer 01 of the composite film is a white coating. The Lab values ​​of the white coating and the white backsheet satisfy the following limitations: ΔL1 is the absolute value of the difference between the color value of the white coating and the color value of the white backsheet, ΔL1 being 0~6; Δa1 is the absolute value of the difference between the a value of the white coating and the a value of the white backsheet, Δa1 being 0.5~3.5; Δb1 is the absolute value of the difference between the b value of the white coating and the b value of the white backsheet, Δb1 being 2~6. Since the color of the composite film is mainly determined by the color of the coating layer 01, when a white backsheet is used, if the Lab values ​​of the white coating and the backsheet of the composite film meet the above requirements, the photovoltaic module will appear uniform in color and more aesthetically pleasing. Preferably, the color difference ΔE1 between the white coating and the white backsheet is 2.06~9.18.

[0052] In some embodiments of this application, the backsheet is black, and the coating layer 01 of the composite film is a black coating. The Lab values ​​of the black coating and the white backsheet satisfy the following limitations: ΔL2 is the absolute value of the difference between the color value of the black coating and the color value of the black backsheet, where ΔL2 is 2~6; Δa2 is the absolute value of the difference between the a value of the black coating and the a value of the black backsheet, where Δa2 is 0~4; Δb2 is the absolute value of the difference between the b value of the black coating and the b value of the black backsheet, where Δb2 is 0~4. When a black backsheet is used, if the Lab values ​​of the black coating and the backsheet of the composite film meet the above requirements, the photovoltaic module appears uniformly colored and is more aesthetically pleasing. Preferably, the color difference ΔE2 between the black coating and the black backsheet is 1.41~8.25.

[0053] In some embodiments of this application, △L3 is the absolute value of the difference between the color value of the black coating and the color value of the solar cell, and △L3 is 1~9; △a3 is the absolute value of the difference between the a value of the black coating and the a value of the solar cell, and △a3 is 0~4; △b3 is the absolute value of the difference between the b value of the black coating and the b value of the solar cell, and △b3 is 0~4, making the photovoltaic module more aesthetically pleasing overall. More preferably, the color difference △E3 between the black coating and the solar cell is 1~10.63.

[0054] Understandably, the color of the composite film coating layer 01 can be adjusted by adjusting the particle size and content of the coloring pigments in the composite film, or the thickness of the coating layer 01 and the yellowness of the substrate 02, so that the color of the composite film is coordinated with the color of the backsheet or solar cells in the photovoltaic module.

[0055] The technical effects that this technical solution can achieve will be further described below with reference to the embodiments and comparative examples.

[0056] Example 1

[0057] 1) A white coating is prepared by sand milling 35 parts by weight of resin JF-3X, 30 parts by weight of pigment (titanium dioxide R105, D90 particle size of 0.3μm), 0.5 parts by weight of dispersant BYK-111, 5 parts by weight of curing agent (Desmodur® N 3900), 0.01 parts by weight of catalyst stannous octoate solution and 30 parts by weight of solvent propylene glycol methyl ether acetate (PMA).

[0058] 2) Apply white coating to both surfaces of substrate 02 (polyimide film, 25μm thick, yellowness value A: 15), bake at 175℃ for 3 minutes to form coating layer 01, which is 8μm thick. Apply EVA film to one side of the coating layer opposite the substrate to form adhesive layer 03, which is 50μm thick. Cut into 5mm strips and roll up to obtain a white photovoltaic module composite film, with the structure as shown. Figure 1 As shown.

[0059] Example 2

[0060] 1) Prepare a black coating by sand milling 35 parts by weight of resin JF-3X, 10 parts by weight of pigment (carbon black, D90 particle size of 15μm), 0.5 parts by weight of dispersant Afcona4320, 4.3 parts by weight of curing agent (Wannate® HT-100), 0.01 parts by weight of catalyst stannous octoate solution and 30 parts by weight of solvent PMA.

[0061] 2) Apply black coating to both sides of substrate 02 (polyimide film, 25 μm thick, yellowness value A: 15), bake at 175°C for 3 minutes to form coating layer 01, which is 5 μm thick. Apply EVA film to one side of the coating layer opposite the substrate to form adhesive layer 03, which is 50 μm thick. Cut into 5 mm strips and roll up to obtain a black photovoltaic module composite film, with the structure as shown. Figure 1 As shown.

[0062] Example 3

[0063] The difference from Example 1 is that in step 1), the pigment has 10 parts by weight; and in step 2), the thickness of the white coating is 15 μm.

[0064] Example 4

[0065] The difference from Example 2 is that in step 1), the weight of the pigment is 20 parts; and in step 2), the thickness of the black coating is 10 μm.

[0066] Example 5

[0067] The difference from Example 1 is that in step 1), the particle size of the pigment is 0.5 μm; and in step 2), the thickness of the white coating is 10 μm.

[0068] Example 6

[0069] The difference from Example 1 is that in step 1), the particle size of the pigment is 1.5 μm.

[0070] Example 7

[0071] The difference from Example 2 is that in step 1), the particle size of the pigment is 8 μm.

[0072] Example 8

[0073] The difference from Example 2 is that in step 1), the particle size of the pigment is 30 μm.

[0074] Example 9

[0075] The difference from Example 1 is that the color value L1 of the white coating is 90, and in step 2), the substrate 02 is a transparent PET film with a yellowness value A of 13, and the thickness of the white coating is 10 μm.

[0076] Example 10

[0077] The difference from Example 1 is that the color value L1 of the white coating is 75, and in step 2), the substrate 02 is a PI film with a thickness of 25 μm, a yellowness value A of 35, and a thickness of 10 μm.

[0078] Example 11

[0079] The difference from Example 2 is that the color value L2 of the black coating is 20, and in step 2), the substrate 02 is a white PET film with a yellowness value A of 10, and the thickness of the black coating is 5μm.

[0080] Example 12

[0081] The difference from Example 2 is that the color value L2 of the black coating is 25, and in step 2), the substrate 02 is a PI film with a yellowness value A of 35.

[0082] Comparative Example 1

[0083] The difference from Example 1 is that in step 1), the weight of the pigment is 30 parts; and in step 2), the thickness of the white coating is 30 μm.

[0084] Comparative Example 2

[0085] The difference from Example 2 is that in step 1), the weight of the pigment is 5 parts; and in step 2), the thickness of the black coating is 6 μm.

[0086] The photovoltaic module composite films of Examples 1, 3, 5, 6, 9, 10 and Comparative Example 1 are white coatings, and their color-related indicators are summarized in Table 1 below.

[0087] Table 1

[0088]

[0089] The photovoltaic module composite films of Examples 2, 4, 7, 8, 11, 12 and Comparative Example 2 are black coatings, and their color-related indicators are summarized in Table 2 below.

[0090] Table 2

[0091]

[0092] The color difference values ​​of the photovoltaic module composite films of the above embodiments and comparative examples were obtained by colorimeter testing. The color difference data between the white photovoltaic module composite film and the white backsheet are shown in Table 3, the color difference data between the black photovoltaic module composite film and the black backsheet are shown in Table 4, and the color difference value between the black photovoltaic module composite film and the solar cell is shown in Table 5.

[0093] Table 3

[0094]

[0095] Table 4

[0096]

[0097] Table 5

[0098]

[0099] Among them, the pigment mass content and coating thickness of Comparative Examples 1 and 2 are positively correlated, resulting in a large color difference between the photovoltaic module composite film and the backsheet and battery cells, which leads to poor hiding power.

[0100] As can be seen from the above description, this application has discovered that the thickness of the coating layer and the content of coloring pigments in the coating layer have a significant impact on the color of the coating. When photovoltaic module composite films are applied to photovoltaic cell assemblies with white or black backsheets and placed between the cells to cover the solder ribbons, controlling the coating layer thickness and the mass percentage of coloring pigments in the coating layer to be negatively correlated can improve the hiding power of the photovoltaic module composite film, making the overall module appear uniform in color and aesthetically pleasing after covering, thereby better meeting the requirements of building-integrated photovoltaics.

[0101] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A photovoltaic module composite film, characterized in that, The photovoltaic module composite film includes a substrate and coating layers on both surface sides of the substrate, and an adhesive layer is provided on one side of one of the coating layers opposite to the substrate; The materials of the coating layer include: resin, coloring pigment, dispersion aid, curing agent and catalyst; The coating layer is entirely a white coating or entirely a black coating; The thickness of the coating layer is negatively correlated with the mass percentage content of the coloring pigment in the coating layer.

2. The photovoltaic module composite film according to claim 1, characterized in that, When the coating layer is a white coating, the coloring pigment is a white pigment, the thickness of the coating layer is H1, with the unit of μm, 1≤H1≤20, the numerical value of the mass percentage content of the coloring pigment in the coating layer is M1, with the unit of %, and the H1 and the M1 satisfy the formula k1 = M1×H1; where k1 is a constant, and when 1≤H1<10, k1 is 100~250, when 10≤H1≤20, k1 is 150~400; Or, when the coating layer is a black coating, the coloring pigment is a black pigment, the thickness of the coating layer is H2, with the unit of μm, 1≤H2≤15, the numerical value of the mass percentage content of the coloring pigment in the coating layer is M2, with the unit of %, and the H2 and the M2 satisfy the formula k4 = M2×H2; where k4 is a constant, and when 1≤H2<8, k4 is 50~200, when 8≤H2≤15, k4 is 150~350.

3. The photovoltaic module composite film according to claim 2, characterized in that, When the coating layer is a white coating, the D90 particle size of the white pigment is D1, with the unit of μm, 0.1≤D1≤0.8, and the D1 satisfies the formula k2 = M1×D1; where k2 is a constant, and when 0.1≤D1≤0.3, k2 is 2~12, when 0.3<D1≤0.8, k2 is 7~40; Or, when the coating layer is a black coating, the D90 particle size of the black pigment is D2, with the unit of μm, 1≤D2≤20, and the D2 and the M2 satisfy the formula k5 = M2×D2; where k5 is a constant, and when 1≤D2<10, k5 is 100~300, when 10≤D2≤20, k5 is 150~500.

4. The photovoltaic module composite film according to claim 3, characterized in that, When the coating layer is a white coating, the color value of the white coating is L1, 85≤L1≤95, and the L1 satisfies the formula k3 = L1×D1×A / (M1×H1); where A is the yellowness value of the substrate, A is 10~30; k3 is a constant, and when 85≤L1<90, k3 is 2.00~2.30, when 90≤L1≤95, k3 is 2.20~2.50; Or, when the coating layer is a black coating, the color value of the black coating is L2, 20≤L2≤25, and L2 satisfies k6 = L2×D2×A / (M2×H2), where A is the yellowness value of the substrate, A is 10~30; k6 is a constant, and when 20≤L2≤23, k6 is 15~35, when 23<L2≤25, k6 is 10~30.

5. The photovoltaic module composite film according to any one of claims 2 to 4, characterized in that, The M1 is 10~40; and / or, the M2 is 10~40.

6. The photovoltaic module composite film according to claim 2, characterized in that, The white pigment is any one or more of titanium dioxide, talc, calcium carbonate, and barium sulfate; The black pigment is any one or more of carbon black, titanium black, manganese iron black, and copper chromium black.

7. The photovoltaic module composite film according to any one of claims 1 to 4, characterized in that, The material of the substrate is any one or more of polyimide, polyethylene terephthalate, and polyethylene naphthalate; and / or, the thickness of the substrate is 15~35μm; And / or, the material of the adhesive layer is any one or more of ethylene-vinyl acetate copolymer, polyolefin elastomer, polyethylene and polyurethane; and / or, the thickness of the adhesive layer is 40~60μm.

8. A method for preparing a photovoltaic module composite film according to any one of claims 1 to 7, characterized in that, The preparation method includes: The raw materials, including the coating material and solvent, are mixed and milled to obtain a coating slurry; the coating slurry is applied to both sides of the substrate and dried to form a coating layer; An adhesive layer is provided on the side of one of the coating layers opposite to the substrate.

9. The preparation method according to claim 8, characterized in that, The drying temperature is 150~180℃, and the drying time is 2~10min.

10. A photovoltaic module, comprising solar cells, a backsheet, and a composite film disposed between the solar cells, characterized in that, The composite film is the photovoltaic module composite film according to any one of claims 1 to 7 or is prepared by the preparation method according to claim 8 or 9.

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