High-reflection black adhesive film and photovoltaic module

Abstract

The invention provides a high black reflection packaging adhesive film and a photovoltaic module. The high-reflection black packaging adhesive film comprises a color adhesive film layer and an infrared high-reflection adhesive film layer tightly combined with the color adhesive film layer, the color adhesive film layer comprises first matrix resin and metal pigments, and the metal pigments are composed of red metal pigments, yellow metal pigments and blue metal pigments. The infrared high-reflection adhesive film layer comprises second matrix resin and infrared high-reflection filler; and the reflectivity for light in the wavelength range of 400-700 nm is greater than 30%, and the reflectivity for light in the wavelength range of 700-1100 nm is greater than 70%. When the high-reflection black packaging adhesive film is used as a packaging adhesive film on the reverse side of a battery piece, the whole photovoltaic module can be black, and compared with a black high-reflection adhesive film prepared from organic pigment, the high-reflection black adhesive film has better temperature resistance, light resistance and migration resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging adhesive films and photovoltaic modules, and in particular to a highly reflective black packaging adhesive film and a photovoltaic module using the highly reflective black packaging adhesive film. Background Art

[0002] With the customization of photovoltaic modules, especially the use of photovoltaic modules in roofs, exterior walls and other scenes, people have increasingly stringent requirements on the appearance and color of modules, among which black modules are the most in demand. At present, black modules are generally prepared by using black backplane encapsulation, but because there is an encapsulation film between the backplane and the battery, it cannot be fully reflected to the front of the battery, reducing the utilization rate of light. Therefore, more and more people are focusing on the research of encapsulation film.

[0003] Photovoltaic cells mainly absorb and utilize visible light in the range of 400 to 700 nm. Infrared light with a wavelength greater than 1100 nm will not stimulate the photovoltaic effect of the cell. The current high-reflection black film generally uses visually black organic black high-transmittance pigments, superimposed with white films to achieve a high-reflection effect. However, the light resistance, weather resistance, and color migration resistance of organic pigments are far inferior to those of metal fillers. At the same time, the transmittance of organic black high-transmittance pigments in the range of 400 to 700 nm is less than 3%, and the superimposed white film cannot reflect light in the band of 400 to 700 nm. Therefore, it is urgent to develop a high-reflection black film with good light resistance, weather resistance, and migration resistance, and a reflective effect in the band of 400 to 1100 nm. Summary of the invention

[0004] The invention provides a high-reflective black adhesive film, which has good light resistance, weather resistance and migration resistance, and has a reflective effect in the 400-1100nm band. A photovoltaic module using the high-reflective black adhesive film will not change color or fade during long-term operation.

[0005] An object of the present invention is to provide a highly reflective black film, using the following technical solution:

[0006] A high-reflection black film comprises a color film layer and an infrared high-reflection film layer tightly combined with the color film layer, wherein the color film layer comprises a first matrix resin and a metal pigment dispersed in the first matrix resin, wherein the metal pigment is composed of a red metal pigment, a yellow metal pigment and a blue metal pigment, and the infrared high-reflection film layer comprises a second matrix resin and an infrared high-reflection filler dispersed in the second matrix resin, so that the combination of the color film layer and the infrared high-reflection film layer has a reflectivity greater than 30% for light in the wavelength range of 400 to 700 nm, and a reflectivity greater than 70% for light in the wavelength range of 700 to 1100 nm.

[0007] Furthermore, the weight of the metal pigment accounts for 0.3-10 wt % of the weight of the first resin.

[0008] Furthermore, the weight ratio of the red metallic pigment, the yellow metallic pigment and the blue metallic pigment is 1:(1-4):(1-5).

[0009] Furthermore, the red metallic pigment is selected from one or more of iron oxide red, cobalt red, cadmium red, iron red, molybdenum chrome red, and composite titanium red; the yellow metallic pigment is selected from one or more of titanium yellow, titanium nickel yellow, cadmium yellow, iron yellow, vanadium yellow, chrome yellow, and iron oxide yellow; the blue metallic pigment is selected from one or more of cobalt blue, cobalt chrome blue, iron blue, and ultramarine.

[0010] Furthermore, the infrared high-reflective filler is selected from one or more of titanium dioxide, talc, barium sulfate, silicon dioxide, mica, aluminum hydroxide, aluminum oxide, magnesium hydroxide, kaolin, and calcium carbonate.

[0011] Furthermore, the infrared high-reflective filler is selected from one or more of titanium dioxide, talc, barium sulfate, silicon dioxide, mica, aluminum hydroxide, aluminum oxide, magnesium hydroxide, kaolin, and calcium carbonate.

[0012] Furthermore, the first matrix resin and the second matrix resin are selected from one or more of ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethyl methacrylate copolymer, ethylene-butyl acrylate copolymer, silica gel, polyvinyl butyral, and ionomer.

[0013] Furthermore, the pre-crosslinking degree of the color adhesive film layer is 5-50%, and the pre-crosslinking degree of the infrared high-reflection adhesive film layer is 10-60%.

[0014] Furthermore, the thickness of the color adhesive film layer is 80-400 μm, and the thickness of the infrared high-reflection adhesive film layer is 100-500 μm.

[0015] Furthermore, the color adhesive film layer and the infrared high-reflection adhesive film layer independently include one or more of a cross-linking agent, a co-cross-linking agent, a light stabilizer, and a tackifier.

[0016] Another object of the present invention is to provide a photovoltaic module, which adopts the following technical solution:

[0017] A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer comprises a color film layer and an infrared high-reflection film layer tightly combined with the color film layer, the color film layer comprises a first matrix resin and a metallic pigment dispersed in the first matrix resin, the metallic pigment consists of a red metallic pigment, a yellow metallic pigment and a blue metallic pigment, and the infrared high-reflection film layer comprises a second matrix resin and an infrared high-reflection filler dispersed in the second matrix resin.

[0018] Furthermore, the weight of the metal pigment accounts for 0.3-10 wt % of the weight of the first resin.

[0019] Furthermore, the weight ratio of the red metallic pigment, the yellow metallic pigment and the blue metallic pigment is 1:(1-4):(1-5).

[0020] Furthermore, the red metallic pigment is selected from one or more of iron oxide red, cobalt red, cadmium red, iron red, molybdenum chrome red, and composite titanium red; the yellow metallic pigment is selected from one or more of titanium yellow, titanium nickel yellow, cadmium yellow, iron yellow, vanadium yellow, chrome yellow, and iron oxide yellow; the blue metallic pigment is selected from one or more of cobalt blue, cobalt chrome blue, iron blue, and ultramarine.

[0021] Furthermore, the infrared high-reflective filler is selected from one or more of titanium dioxide, talc, barium sulfate, silicon dioxide, mica, aluminum hydroxide, aluminum oxide, magnesium hydroxide, kaolin, and calcium carbonate.

[0022] Furthermore, the infrared high-reflective filler is selected from one or more of titanium dioxide, talc, barium sulfate, silicon dioxide, mica, aluminum hydroxide, aluminum oxide, magnesium hydroxide, kaolin, and calcium carbonate.

[0023] Furthermore, the first matrix resin and the second matrix resin are selected from one or more of ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethyl methacrylate copolymer, ethylene-butyl acrylate copolymer, silica gel, polyvinyl butyral, and ionomer.

[0024] Furthermore, the pre-crosslinking degree of the color adhesive film layer is 5-50%, and the pre-crosslinking degree of the infrared high-reflection adhesive film layer is 10-60%.

[0025] Furthermore, the thickness of the color adhesive film layer is 80-400 μm, and the thickness of the infrared high-reflection adhesive film layer is 100-500 μm.

[0026] Furthermore, the color adhesive film layer and the infrared high-reflection adhesive film layer independently include one or more of a cross-linking agent, a co-cross-linking agent, a light stabilizer, and a tackifier.

[0027] In summary, the present invention has the following beneficial effects:

[0028] 1. The pigments used in the present invention are all metallic pigments, which have better light resistance, weather resistance, and migration resistance than organic pigments, and have a reflective effect in the 400-1100nm band.

[0029] 2. The metallic pigment used in the present invention is composed of a red metallic pigment, a yellow metallic pigment and a blue metallic pigment, so that the metallic pigment presents a pure black color, avoiding the impure color of a single black pigment, such as greenish or reddish.

[0030] 3. Photovoltaic modules using this highly reflective black film will not change color or fade during long-term operation. DETAILED DESCRIPTION

[0031] The detailed description of the present invention and its embodiments are described one by one in the following detailed description in a non-limiting manner; wherein, the described parts are merely embodiments of the present invention and have no direct impact on the scope of the present invention, so the following description should not be interpreted in a limiting manner.

[0032] One object of the present invention is to provide a high-reflection black film, comprising a color film layer and an infrared high-reflection film tightly combined with the color film layer; the color film layer comprises a first matrix resin and a metal pigment dispersed in the first matrix resin; the metal pigment is composed of a red metal pigment, a yellow metal pigment and a blue metal pigment; the infrared high-reflection film layer comprises a second matrix resin and an infrared high-reflection filler dispersed in the second matrix resin, so that the combination of the color film layer and the infrared high-reflection film has a reflectivity greater than 30% for light in the wavelength range of 400 to 700 nm and a reflectivity greater than 70% for light in the wavelength range of 700 to 1100 nm.

[0033] In some embodiments, the weight of the metallic pigment accounts for 0.3-10wt% of the weight of the first resin, and further, the weight ratio of the red metallic pigment, the yellow metallic pigment, and the blue metallic pigment is 1: (1-4): (1-5). The amount of metallic pigment added needs to be controlled within a certain range to prevent excessive addition of metallic pigments, which affects the bonding performance of the color film layer, and too little addition of metallic pigments, resulting in no obvious black or too low reflectivity. The metallic pigment has the advantages of good weather resistance and long-lasting color, so that the color of the high-reflective black film using metallic pigments will not change with time, and the metallic pigment is not easy to migrate in the high-reflective black film, and will not occur similar to the phenomenon of migration and agglomeration of organic pigments in the film, resulting in uneven color distribution of the film and different depths. Further, the red metallic pigment is selected from one or more of iron oxide red, cobalt red, cadmium red, iron red, molybdenum chrome red, and composite titanium red, the yellow metallic pigment is selected from one or more of titanium yellow, titanium nickel yellow, cadmium yellow, iron yellow, vanadium yellow, chrome yellow, and iron oxide yellow, and the blue metallic pigment is selected from one or more of cobalt blue, cobalt chrome blue, iron blue, and ultramarine.

[0034] In some embodiments, the first matrix resin and the second matrix resin are selected from one or more of ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethyl methacrylate copolymer, ethylene-butyl acrylate copolymer, silica gel, polyvinyl butyral, and ionomer.

[0035] In certain embodiments, the infrared high reflective filler is selected from one or more of titanium dioxide, talc, barium sulfate, silica, mica, aluminum hydroxide, aluminum oxide, magnesium hydroxide, kaolin, and calcium carbonate.

[0036] In some embodiments, the pre-crosslinking degree of the color film layer is 5-50%, and the pre-crosslinking degree of the infrared high-reflection film layer is 10-60%. In this way, the problem that the uncrosslinked color film layer flows to the front of the battery cell in a molten state during application, especially during lamination, causing shielding and affecting the output power of the battery cell can be avoided; at the same time, the uncrosslinked color film layer and the infrared high-reflection film layer can be avoided from flowing to each other's area in a molten state and mixing together, causing the color of the color film layer to be inconsistent.

[0037] In some embodiments, the thickness of the color film layer is 80-400 μm, and the thickness of the infrared high-reflection film layer is 100-500 μm.

[0038] In some embodiments, the color adhesive film layer and the infrared high-reflection adhesive film layer independently include one or more of a cross-linking agent, a co-cross-linking agent, a light stabilizer, and a tackifier.

[0039] Another object of the present invention is to provide a photovoltaic module, comprising a front transparent glass packaging layer, a first packaging film layer, a battery cell array, a second packaging film layer and a back packaging layer, the second packaging film layer comprising a color film layer and an infrared high-reflection film tightly combined with the color film layer; the color film layer comprises a first base resin and a metallic pigment; the metallic pigment is composed of a red metallic pigment, a yellow metallic pigment and a blue metallic pigment; the infrared high-reflection film layer comprises a second base resin and an infrared high-reflection filler; and the reflectivity of the high-reflection black film to light in the wavelength range of 400 to 700 nm is greater than 30%, and the reflectivity to light in the wavelength range of 700 to 1100 nm is greater than 70%.

[0040] In some embodiments, the weight of the metallic pigment accounts for 0.3-10wt% of the weight of the first resin, and further, the weight ratio of red metallic pigment: yellow metallic pigment: blue metallic pigment is 1: (1-4): (1-5). The amount of metallic pigment added needs to be controlled within a certain range to prevent excessive addition of metallic pigment, which affects the bonding performance of the color film layer, and too little metallic pigment, which results in no obvious black color or too low reflectivity. Metallic pigments have the advantages of good weather resistance and long-lasting color, so the color of the high-reflective black film using metallic pigments will not change over time, and the metallic pigment is not easy to migrate in the high-reflective black film, and will not occur similar to the phenomenon of organic pigments migrating and agglomerating in the film, resulting in uneven color distribution and different shades of the film. Furthermore, the red metallic pigment is selected from one or more of iron oxide red, cobalt red, cadmium red, iron red, molybdenum chrome red, and composite titanium red; the yellow metallic pigment is selected from one or more of titanium yellow, titanium nickel yellow, cadmium yellow, iron yellow, vanadium yellow, chrome yellow, and iron oxide yellow; and the blue metallic pigment is selected from one or more of cobalt blue, cobalt chrome blue, iron blue, and ultramarine.

[0041] In certain embodiments, the infrared high reflective filler is selected from one or more of titanium dioxide, talc, barium sulfate, silica, mica, aluminum hydroxide, aluminum oxide, magnesium hydroxide, kaolin, and calcium carbonate.

[0042] In some embodiments, the first matrix resin and the second matrix resin are selected from one or more of ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethyl methacrylate copolymer, ethylene-butyl acrylate copolymer, silica gel, polyvinyl butyral, and ionomer.

[0043] In some embodiments, the pre-crosslinking degree of the color film layer is 5-50%, and the pre-crosslinking degree of the infrared high-reflection film layer is 10-60%. In this way, the problem that the uncrosslinked color film layer flows to the front of the battery cell in a molten state during application, especially during lamination, causing shielding and affecting the output power of the battery cell can be avoided; at the same time, the uncrosslinked color film layer and the infrared high-reflection film layer can be avoided from flowing to each other's area in a molten state and mixing together, causing the color of the color film layer to be inconsistent.

[0044] In some embodiments, the thickness of the color film layer is 80-400 μm, and the thickness of the infrared high-reflection film layer is 100-500 μm.

[0045] In some embodiments, the color adhesive film layer and the infrared high-reflection adhesive film layer independently include one or more of a cross-linking agent, a co-cross-linking agent, a light stabilizer, and a tackifier.

[0046] Example

[0047] An object of the present invention is to provide a high-reflective black adhesive film, and the high-reflective black adhesive film is further described through embodiments and comparative examples.

[0048] The base resin used in the following examples and comparative examples is ethylene-vinyl acetate copolymer (UE2825 Sailbon) or ethylene-α-olefin copolymer (Mitsui Chemicals A-20070S);

[0049] The crosslinking agent is tert-butyl peroxy 2-ethylhexyl carbonate;

[0050] The auxiliary cross-linking agent is triallyl isocyanurate;

[0051] The light stabilizer is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate;

[0052] The adhesion promoter is vinyltrioxysilane.

[0053] Embodiment 1: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly combined with the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 0.1 parts of iron red, 0.4 parts of titanium nickel yellow, 0.5 parts of cobalt blue, 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 250 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 5 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 250 microns; the pre-crosslinking degree is 25%.

[0054] Embodiment 2: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly bonded to the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 0.2 parts of iron red, 0.8 parts of titanium nickel yellow, 1 part of cobalt blue, 0.7 parts of a crosslinking agent, 0.8 parts of a co-crosslinking agent, 0.3 parts of a light stabilizer, and 0.3 parts of a tackifier; the thickness is 250 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 5 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of a crosslinking agent, 0.8 parts of a co-crosslinking agent, 0.3 parts of a light stabilizer, and 0.3 parts of a tackifier; the thickness is 250 microns; the pre-crosslinking degree is 25%.

[0055] Embodiment 3: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly bonded to the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 1 part of iron red, 4 parts of titanium nickel yellow, 5 parts of cobalt blue, 0.7 parts of a crosslinking agent, 0.8 parts of a co-crosslinking agent, 0.3 parts of a light stabilizer, and 0.3 parts of a tackifier; the thickness is 250 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 5 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of a crosslinking agent, 0.8 parts of a co-crosslinking agent, 0.3 parts of a light stabilizer, and 0.3 parts of a tackifier; the thickness is 250 microns; the pre-crosslinking degree is 25%.

[0056] Embodiment 4: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly combined with the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 0.1 parts of molybdenum red, 0.4 parts of titanium yellow, 0.5 parts of iron blue, 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 250 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 5 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 250 microns; the pre-crosslinking degree is 25%.

[0057] Embodiment 5: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly bonded to the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 0.1 parts of iron red, 0.4 parts of titanium nickel yellow, 0.5 parts of cobalt blue, 0.7 parts of a crosslinking agent, 0.8 parts of a co-crosslinking agent, 0.3 parts of a light stabilizer, and 0.3 parts of a tackifier; the thickness is 250 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 3 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of a crosslinking agent, 0.8 parts of a co-crosslinking agent, 0.3 parts of a light stabilizer, and 0.3 parts of a tackifier; the thickness is 250 microns; the pre-crosslinking degree is 25%.

[0058] Embodiment 6: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly bonded to the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 0.1 parts of iron red, 0.4 parts of titanium nickel yellow, 0.5 parts of cobalt blue, 0.7 parts of a crosslinking agent, 0.8 parts of a co-crosslinking agent, 0.3 parts of a light stabilizer, and 0.3 parts of a tackifier; the thickness is 250 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 8 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of a crosslinking agent, 0.8 parts of a co-crosslinking agent, 0.3 parts of a light stabilizer, and 0.3 parts of a tackifier; the thickness is 250 microns; the pre-crosslinking degree is 25%.

[0059] Embodiment 7: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly combined with the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 0.1 parts of iron red, 0.4 parts of titanium nickel yellow, 0.5 parts of cobalt blue, 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 250 microns; the pre-crosslinking degree is 30%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 5 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 250 microns; the pre-crosslinking degree is 50%.

[0060] Embodiment 8: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly bonded to the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 0.1 parts of iron red, 0.4 parts of titanium nickel yellow, 0.5 parts of cobalt blue, 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 100 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 5 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 400 microns; the pre-crosslinking degree is 25%.

[0061] Embodiment 9: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly bonded to the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 0.1 parts of iron red, 0.4 parts of titanium nickel yellow, 0.5 parts of cobalt blue, 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 400 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 5 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 100 microns; the pre-crosslinking degree is 25%.

[0062] Embodiment 10: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly bonded to the color film layer. The color film layer comprises 100 parts of ethylene-α-olefin copolymer, 0.1 parts of iron red, 0.4 parts of titanium nickel yellow, 0.5 parts of cobalt blue, 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 250 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 5 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 250 microns; the pre-crosslinking degree is 25%.

[0063] Comparative Example 1: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly bonded to the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 1 part of carbon black, 0.7 parts of a crosslinking agent, 0.8 parts of a co-crosslinking agent, 0.3 parts of a light stabilizer, and 0.3 parts of a tackifier; the thickness is 400 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 5 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of a crosslinking agent, 0.8 parts of a co-crosslinking agent, 0.3 parts of a light stabilizer, and 0.3 parts of a tackifier; the thickness is 100 microns; the pre-crosslinking degree is 25%.

[0064] Comparative Example 2: A highly reflective black film, comprising a color film layer and an infrared highly reflective film layer tightly bonded to the color film layer. The color film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 1 part of organic pigment (perylene black L0086), 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 400 microns; the pre-crosslinking degree is 15%. The infrared highly reflective film layer comprises 100 parts of ethylene-vinyl acetate copolymer, 5 parts of titanium dioxide (particle size 0.5 microns), 0.7 parts of crosslinking agent, 0.8 parts of auxiliary crosslinking agent, 0.3 parts of light stabilizer and 0.3 parts of tackifier; the thickness is 100 microns; the pre-crosslinking degree is 25%.

[0065] Performance testing

[0066] The high-reflective black adhesive films described in the above embodiments and comparative examples were tested for their performance by referring to the following method, and the test results were recorded in Table 1.

[0067] 1. Reflectivity: Take a piece of high-reflective black film with a size of 50mmX50 mm, and stack the board material, non-stick film, high-reflective black film, non-stick film, and backboard material from bottom to top. Put the front board into the vacuum laminator with the front board facing down, and perform curing and cross-linking according to the curing temperature and time required by the product. Then take it out and put it into the dryer to cool to room temperature for use. The sample removed from the non-stick film requires the upper and lower surfaces to be flat, the thickness to be uniform, and the cross-linking degree to reach more than 75%. Test the sample according to the spectrophotometer method of ASTM E 424-71 (2015). The wavelength range of the spectrophotometer is set to 400nm~1100nm. Take the average value of the test results of 400nm~700nm and 700nm~1100nm respectively.

[0068] 2. Ultraviolet high temperature and high humidity aging test: Take a highly reflective black film with a size of 300mmX300 mm, sandwich it between the ultra-white embossed tempered glass and the back panel with a size of 300mmX300 mm, and the color film layer faces the glass. Curing and cross-linking are carried out according to the curing temperature and time required by the product to obtain a laminated sample. Prepare 3 laminated samples. The test process is as follows: Place the glass surface of the sample facing the light source and place it in the effective irradiation area of ​​the ultraviolet high temperature and high humidity aging test chamber. Test conditions: a) Ultraviolet spectrum distribution: 280nm~400nm (UVB280nm~320nm, UVA320nm~400nm); radiation intensity: 120W / m~250W / m%, UVB accounts for 3%~10% of UV (A+B) energy; while irradiating with ultraviolet light, the surface temperature of the sample in the test chamber is maintained at 85℃±2℃, and the relative humidity is maintained at 85%±5%; irradiation power accumulation: accumulate according to the actual irradiation amount received by the sample surface. b) Test time: 300h based on high temperature and high humidity operation time. c) After the test, take out the sample and restore it in an open environment at 23℃ and relative humidity less than 75% for 2h~4h, and then check the appearance to see if the color distribution is uniform. d) Measure the color value of the laminated sample before and after the test according to ASTM E313-2010, and calculate the color difference.

[0069] Table 1 Performance test results of high reflective black film

[0070]

[0071]

[0072] It can be seen from the data in Table 1 that the reflectivity of Examples 1-10 using metallic pigments to light in the wavelength range of 400-700nm is greater than 30%, while the reflectivity of Comparative Example 1 using carbon black and Comparative Example 2 using organic pigments to light in the wavelength range of 400-700nm is 5%, indicating that the black film using metallic pigments in the present invention has a better reflectivity to light in the wavelength range of 400-700nm than the black film using carbon black or organic pigments in the prior art, which is improved by more than 6 times, thus solving the problem of low reflectivity of black film using prior art to light in the wavelength range of 400-700nm.

[0073] The reflectivity of Examples 1-10 using metallic pigments to light in the wavelength range of 700-1100nm is greater than 75%, while the reflectivity of Comparative Example 1 using carbon black to light in the wavelength range of 700-1100nm is 4%, and the reflectivity of Comparative Example 2 using organic pigments to light in the wavelength range of 700-1100nm is 65%, indicating that the black film using metallic pigments of the present invention has better reflectivity to light in the wavelength range of 400-700nm than the black film using carbon black or organic pigments in the prior art, which is more than 17 times higher than the black film using carbon black and 5% higher than the black film using organic pigments, which helps to improve the reflectivity of the black film to light in the wavelength range of 700-1100nm.

[0074] It can also be seen from the data in Table 1 that after the ultraviolet high temperature and high humidity aging test, the color difference of Examples 1-10 using metal pigments is the smallest, and the color difference of Comparative Example 2 using organic pigments is the largest and is several times the color difference of Examples 1-10, indicating that the black film using metal pigments has excellent temperature resistance and light resistance in color retention, while the black film using organic pigments is much inferior in color retention. After the ultraviolet high temperature and high humidity aging test, the color of Examples 1-10 using metal pigments is still uniform, while the color of the black film using organic pigments is different in depth and color difference, indicating that the black film using metal pigments has excellent migration resistance in color retention.

[0075] Another object of the present invention is to provide a photovoltaic module, which is further described through embodiments and comparative examples.

[0076] The front transparent glass encapsulation layer and the back encapsulation layer used in the following embodiments and comparative examples are ultra-white patterned glass; the first encapsulation film layer is an EPE film; and the battery cell is a TOPCon battery.

[0077] Embodiment 11: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Embodiment 1.

[0078] Embodiment 12: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Embodiment 2.

[0079] Example 13: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Example 3.

[0080] Embodiment 14: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Embodiment 4.

[0081] Example 15: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Example 5.

[0082] Example 16: A photovoltaic module, comprising a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Example 6.

[0083] Embodiment 17: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Embodiment 7.

[0084] Embodiment 18: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Embodiment 8.

[0085] Embodiment 19: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Embodiment 9.

[0086] Embodiment 20: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Embodiment 10.

[0087] Comparative Example 3: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Comparative Example 1.

[0088] Comparative Example 4: A photovoltaic module comprises a front transparent glass encapsulation layer, a first encapsulation film layer, a battery cell array, a second encapsulation film layer and a back encapsulation layer, wherein the second encapsulation film layer is the highly reflective black film described in Comparative Example 2.

[0089] Performance testing

[0090] The photovoltaic modules described in the above embodiments and comparative examples were tested for performance using the following method, and the test results are recorded in Table 2.

[0091] 1. PID (Potential Induced Degradation) Test: Place the PV module in an environmental chamber with a relative humidity of 85% and a temperature of 85°C for 192 hours, and simultaneously apply a voltage of 1500V; test the power of the PV module before and after being placed in the environmental chamber, calculate the power change ratio and record its absolute value, the power change ratio = (power after test - power before test) / power before test.

[0092] Table 2 Performance test results of photovoltaic modules

[0093] project Anti-PID project Anti-PID project Anti-PID Embodiment 11 1.25％ Embodiment 15 1.29％ Embodiment 19 1.38％ Example 12 1.35％ Example 16 1.08％ Embodiment 20 0.5％ Embodiment 13 1.18％ Embodiment 17 1.11％ Comparative Example 3 2.08％ Embodiment 14 1.34％ Embodiment 18 0.98％ Comparative Example 4 1.98％

[0094] The smaller the absolute value of the power change ratio, the smaller the power change amplitude, indicating that the anti-PID performance is better. From the data in Table 2, it can be seen that the anti-PID performance of photovoltaic modules using black films with added metal pigments is better than that of photovoltaic modules using black films with added carbon black or organic pigments; among them, the anti-PID performance of photovoltaic modules using black films with ethylene-α-olefin copolymer as the matrix resin is significantly better.

[0095] In this specification, the present invention has been described with reference to specific embodiments thereof. However, it is apparent that various modifications and variations may be made without departing from the spirit and scope of the present invention. Therefore, the description should be regarded as illustrative rather than restrictive.

Claims

1. A highly reflective black film, characterized in that: It includes a color film layer and an infrared high-reflection film layer tightly combined with the color film layer, the color film layer includes a first matrix resin and a metal pigment dispersed in the first matrix resin, the metal pigment consists of a red metal pigment, a yellow metal pigment and a blue metal pigment, the infrared high-reflection film layer includes a second matrix resin and an infrared high-reflection filler dispersed in the second matrix resin, so that the combination of the color film layer and the infrared high-reflection film layer has a reflectivity greater than 30% for light in the wavelength range of 400 to 700 nm, and a reflectivity greater than 70% for light in the wavelength range of 700 to 1100 nm.

2. The highly reflective black film according to claim 1, characterized in that: The weight of the metal pigment accounts for 0.3-10 wt % of the weight of the first resin.

3. The high-reflective black film according to claim 2, characterized in that: The weight ratio of the red metallic pigment, the yellow metallic pigment and the blue metallic pigment is 1:(1-4):(1-5).

4. The high-reflective black film according to any one of claims 1 to 3, characterized in that: The red metallic pigment is selected from one or more of iron oxide red, cobalt red, cadmium red, iron red, molybdenum chrome red, and composite titanium red; the yellow metallic pigment is selected from one or more of titanium yellow, titanium nickel yellow, cadmium yellow, iron yellow, vanadium yellow, chrome yellow, and iron oxide yellow; the blue metallic pigment is selected from one or more of cobalt blue, cobalt chrome blue, iron blue, and ultramarine.

5. The high-reflective black film according to any one of claims 1 to 3, characterized in that: The infrared high-reflective filler is selected from one or more of titanium dioxide, talc, barium sulfate, silicon dioxide, mica, aluminum hydroxide, aluminum oxide, magnesium hydroxide, kaolin, and calcium carbonate.

6. The high-reflective black film according to any one of claims 4, characterized in that: The infrared high-reflective filler is selected from one or more of titanium dioxide, talc, barium sulfate, silicon dioxide, mica, aluminum hydroxide, aluminum oxide, magnesium hydroxide, kaolin, and calcium carbonate.

7. The high-reflective black film according to claim 6, characterized in that: The first matrix resin and the second matrix resin are selected from one or more of ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethyl methacrylate copolymer, ethylene-butyl acrylate copolymer, silica gel, polyvinyl butyral, and ionomer.

8. The high-reflective black film according to claim 7, characterized in that: The pre-crosslinking degree of the color adhesive film layer is 5-50%, and the pre-crosslinking degree of the infrared high-reflection adhesive film layer is 10-60%.

9. The high-reflective black film according to claim 8, characterized in that: The thickness of the color adhesive film layer is 80-400 μm, and the thickness of the infrared high-reflection adhesive film layer is 100-500 μm.

10. A photovoltaic module, comprising a front transparent glass encapsulation layer, a first encapsulation film layer, a battery array, a second encapsulation film layer and a back encapsulation layer, characterized in that: The second packaging film layer is the high-reflection black film according to any one of claims 1 to 9.

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