Photovoltaic backboard with low water vapor transmittance

Abstract

The invention discloses a photovoltaic backplane with low water vapor transmittance, the photovoltaic backplane with low water vapor transmittance comprises a base material layer, a bonding layer, a water blocking layer and a water absorbing layer, the water blocking layer comprises a first water blocking layer and a second water blocking layer, the first water blocking layer and the second water blocking layer are respectively located at two sides of the base material layer, the inner contact layer is connected with the first waterproof layer through the bonding layer, the second waterproof layer is connected with the base material layer through the bonding layer, and the water absorption layer is connected with the second waterproof layer; the base material layer is any one of PET, PBT and PEN, the first water blocking layer is an inorganic water blocking layer, the second water blocking layer is an organic water blocking layer, the bonding layer is any one of polyurethane, epoxy resin and acrylate, and the water absorption layer comprises water retention resin and a foaming agent. The photovoltaic backboard with low water vapor transmittance provided by the invention has the advantages of good water blocking and heat dissipation effects.

Description

Technical Field

[0001] The invention relates to the technical field of solar cells, and in particular to a photovoltaic back sheet with low water vapor transmission rate. Background Art

[0002] By combining highly weather-resistant polymer materials with metal materials, a photovoltaic backplane with a low water vapor permeability can be produced. However, since this type of photovoltaic backplane is made by stacking different types of polymer materials and metal materials, and the materials of each layer are very different, layer separation is likely to occur during long-term outdoor use. In this way, external water vapor can easily penetrate into the photovoltaic backplane from the side of the layered structure separated from the layers, making it difficult for the photovoltaic backplane to maintain good long-term water-blocking properties, affecting its use. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, an embodiment of the present invention provides a photovoltaic backsheet with low water vapor transmission rate, which has the advantages of good water blocking and heat dissipation effects.

[0004] According to the photovoltaic backsheet with low water vapor permeability of the embodiment of the present invention, the photovoltaic backsheet with low water vapor permeability includes a substrate layer, an adhesive layer, a water-blocking layer and a water-absorbing layer, the water-blocking layer includes a first water-blocking layer and a second water-blocking layer, the first water-blocking layer and the second water-blocking layer are respectively located on both sides of the substrate layer, the inner contact layer is connected to the first water-blocking layer through the adhesive layer, the second water-blocking layer is connected to the substrate layer through the adhesive layer, and the water-absorbing layer is connected to the second water-blocking layer; the substrate layer is any one of PET, PBT, and PEN, the first water-blocking layer is an inorganic water-blocking layer, the second water-blocking layer is an organic water-blocking layer, the adhesive layer is any one of polyurethane, epoxy resin, and acrylate, and the water-absorbing layer includes a water-retaining resin and a foaming agent.

[0005] The photovoltaic back sheet with low water vapor transmission rate according to the embodiment of the present invention has the advantages of good water blocking and heat dissipation effects.

[0006] In some embodiments, the second water-blocking layer includes a water-blocking area and a water-permeable area, the water-blocking area and the water-permeable area are alternately arranged, and the area of ​​the water-blocking area is larger than the area of ​​the water-permeable area.

[0007] In some embodiments, the water-blocking region is any one of PVDF, PE, and PI, and the water-permeable region is any one of MPP, PP, and PTFE.

[0008] In some embodiments, the surface of the water-blocking area is coated with a silane coating, and the water-permeable area is provided with a plurality of water-permeable holes.

[0009] In some embodiments, a weather-resistant layer is disposed between the substrate layer and the second water-blocking layer, and the weather-resistant layer is connected to the substrate layer through the bonding layer.

[0010] In some embodiments, the weather-resistant layer is one of PVDF, PVF, and PCT.

[0011] In some embodiments, the water-retaining resin is any one of polyacrylic acid-acrylamide, polyacrylate, and polyvinyl alcohol.

[0012] In some embodiments, the foaming agent is any one of polyether and polysiloxane.

[0013] In some embodiments, the inner contact layer is any one of PVDF, TPU and PC.

[0014] In some embodiments, the substrate layer is plasma treated after cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the structure of a photovoltaic back sheet with low water vapor transmission rate according to an embodiment of the present invention.

[0016] Figure 2 3 is a schematic diagram of the structure of a second water-blocking layer with low water vapor transmission rate according to an embodiment of the present invention.

[0017] Figure 3 4 is a schematic diagram of the structure of a second water-blocking layer with low water vapor transmission rate according to another embodiment of the present invention.

[0018] Figure numerals: 1, water blocking area; 2, water permeable area. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0020] According to the photovoltaic backsheet with low water vapor permeability of the embodiment of the present invention, the photovoltaic backsheet with low water vapor permeability includes a substrate layer, an adhesive layer, a water-blocking layer and a water-absorbing layer, the water-blocking layer includes a first water-blocking layer and a second water-blocking layer, the first water-blocking layer and the second water-blocking layer are respectively located on both sides of the substrate layer, the inner contact layer is connected to the first water-blocking layer through the adhesive layer, the second water-blocking layer is connected to the substrate layer through the adhesive layer, and the water-absorbing layer is connected to the second water-blocking layer; the substrate layer is any one of PET, PBT, and PEN, the first water-blocking layer is an inorganic water-blocking layer, the second water-blocking layer is an organic water-blocking layer, the adhesive layer is any one of polyurethane, epoxy resin, and acrylate, and the water-absorbing layer includes a water-retaining resin and a foaming agent. Two water-blocking layers are arranged on both sides of the substrate layer to provide water-blocking protection for the substrate layer and reduce the entry of water vapor. The inner contact layer is used to contact the photovoltaic back panel with the packaging film. The inner contact layer has good compatibility with the packaging film and high bonding strength. The water-absorbing layer cooperates with the second water-blocking layer. The water-absorbing layer absorbs water vapor at the second water-blocking layer and retains it through the water-retaining resin. The photovoltaic back panel can be cooled with the help of moisture. The foaming agent is used to form more abundant cavities in the water-absorbing layer, thereby reducing damage to the water-absorbing layer caused by the morphological transformation between dry and wet states and extending the service life.

[0021] The photovoltaic back sheet with low water vapor transmission rate according to the embodiment of the present invention has the advantages of good water blocking and heat dissipation effects.

[0022] In some embodiments, the second water-blocking layer includes a water-blocking area 1 and a water-permeable area 2 , the water-blocking area 1 and the water-permeable area 2 are arranged alternately, and the area of ​​the water-blocking area 1 is larger than the area of ​​the water-permeable area 2 .

[0023] Specifically, the water-blocking area 1 uses a material with high water-blocking properties to ensure that most areas can effectively block water vapor. The water-permeable area 2 uses a material with a certain water permeability to allow a certain amount of water vapor to pass through, so as to facilitate the discharge of internal water vapor. This structure can allow water vapor inside the back sheet to escape through the water-permeable area 2 while maintaining an overall low water vapor permeability, thereby reducing internal moisture accumulation and improving the long-term stability of the photovoltaic module.

[0024] In some embodiments, the water-blocking region 1 is any one of PVDF, PE, and PI, and the water-permeable region 2 is any one of MPP, PP, and PTFE.

[0025] Specifically, PVDF has good water resistance and weather resistance, which can reduce the impact of water vapor in the water permeable area 2 on the water blocking area 1. PE selects HDPE to achieve good water blocking effect. PI has good water resistance and heat resistance, which can meet the high working temperature of photovoltaics. The MPP and PTFE in the water permeable area 2 both form a microporous structure to increase the permeability of water vapor and improve the vapor permeability efficiency. The good water permeability of PP can also be used to improve the vapor permeability efficiency. When in use, the water blocking area 1 is located on one side adjacent to the substrate layer as a whole, and the water permeable area 2 can be a number of strips arranged on the material of the water blocking area 1 to increase the water vapor permeability efficiency of a specific area.

[0026] In some embodiments, the surface of the water-blocking area 1 is coated with a silane coating, and the water-permeable area 2 is provided with a plurality of water-permeable holes.

[0027] Specifically, the silane coating enhances the water-blocking performance and has good stability. Therefore, the same material can be used for the water-blocking area 1 and the water-permeable area 2. The silane coating is applied to the water-blocking area 1 to achieve high water-blocking performance. A number of tiny water-permeable holes are set in the water-permeable area 2 to increase the water vapor permeability and ensure the discharge of water vapor. Selecting the same material to make the second water-blocking layer can reduce the total thickness of the photovoltaic backsheet and simplify the processing technology.

[0028] In some embodiments, a weather-resistant layer is disposed between the substrate layer and the second water-blocking layer, and the weather-resistant layer is connected to the substrate layer via an adhesive layer.

[0029] Specifically, the weather-resistant layer can protect the substrate layer and reduce the damage to the substrate layer caused by factors such as ultraviolet rays and water vapor in the external environment.

[0030] In some embodiments, the weather-resistant layer is one of PVDF, PVF, and PCT.

[0031] Specifically, PVDF is resistant to UV rays, heat, and has good mechanical properties; PVF is resistant to UV rays, has good adhesion, is resistant to changes in temperature and humidity, and is not easy to age; PCT has good heat resistance, good processing properties, and poor hygroscopicity. All three materials have good resistance to the environment and can protect the substrate layer.

[0032] In some embodiments, the water-retaining resin is any one of polyacrylic acid-acrylamide, polyacrylate, and polyvinyl alcohol.

[0033] Specifically, polyacrylic acid-acrylamide is a copolymer with strong water absorption and water retention properties and can absorb and release water repeatedly. Polyacrylate is a transparent polymer with good water absorption and water retention properties. Polyvinyl alcohol is a transparent polymer with good water absorption and water retention properties.

[0034] In some embodiments, the foaming agent is any one of polyether and polysiloxane.

[0035] Specifically, polyether as a foaming agent can form a colorless internal cavity, and polysiloxane as a foaming agent can form a colorless internal cavity, thereby increasing the water absorption capacity of the water absorption layer and improving the water absorption effect.

[0036] In some embodiments, the inner contact layer is any one of PVDF, TPU and PC.

[0037] Specifically, when PVDF is used as the inner contact layer, it has good bonding properties and can be firmly bonded to the packaging film. TPU has good flexibility, good bonding properties and weather resistance and can meet the bonding requirements of the packaging film. PC is a material with good transparency and can reduce light blocking.

[0038] In some embodiments, the substrate layer is plasma treated after cleaning.

[0039] Specifically, plasma treatment of the substrate layer can improve the adhesion between the substrate layer and the adhesive layer and reduce the occurrence of interlayer separation.

[0040] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0042] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0044] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0045] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A photovoltaic backsheet with low water vapor transmission rate, characterized in that: include: A substrate layer, an adhesive layer, a water-blocking layer and a water-absorbing layer, wherein the water-blocking layer comprises a first water-blocking layer and a second water-blocking layer, wherein the first water-blocking layer and the second water-blocking layer are respectively located on both sides of the substrate layer, the inner contact layer is connected to the first water-blocking layer through the adhesive layer, the second water-blocking layer is connected to the substrate layer through the adhesive layer, and the water-absorbing layer is connected to the second water-blocking layer; The substrate layer is any one of PET, PBT, and PEN, the first water-blocking layer is an inorganic water-blocking layer, the second water-blocking layer is an organic water-blocking layer, the bonding layer is any one of polyurethane, epoxy resin, and acrylate, and the water-absorbing layer includes a water-retaining resin and a foaming agent.

2. The photovoltaic backsheet with low water vapor transmission rate according to claim 1, characterized in that: The second water-blocking layer comprises a water-blocking area and a water-permeable area, the water-blocking area and the water-permeable area are arranged alternately, and the area of ​​the water-blocking area is larger than the area of ​​the water-permeable area.

3. The photovoltaic backsheet with low water vapor transmission rate according to claim 2, characterized in that: The water blocking area is any one of PVDF, PE, and PI, and the water permeable area is any one of MPP, PP, and PTFE.

4. The photovoltaic backsheet with low water vapor transmission rate according to claim 2, characterized in that: The surface of the water blocking area is coated with a silane coating, and the water permeable area is provided with a plurality of water permeable holes.

5. The photovoltaic backsheet with low water vapor transmission rate according to claim 2, characterized in that: A weather-resistant layer is disposed between the substrate layer and the second water-blocking layer, and the weather-resistant layer is connected to the substrate layer through the bonding layer.

6. The photovoltaic back sheet with low water vapor transmission rate according to claim 5, characterized in that: The weather-resistant layer is one of PVDF, PVF and PCT.

7. The photovoltaic backsheet with low water vapor transmission rate according to claim 1, characterized in that: The water-retaining resin is any one of polyacrylic acid-acrylamide, polyacrylate, and polyvinyl alcohol.

8. The photovoltaic backsheet with low water vapor transmission rate according to claim 1, characterized in that: The foaming agent is any one of polyether and polysiloxane.

9. The photovoltaic backsheet with low water vapor transmission rate according to claim 1, characterized in that: The inner contact layer is any one of PVDF, TPU and PC.

10. The photovoltaic back sheet with low water vapor transmission rate according to claim 1, characterized in that: The substrate layer is then plasma treated after cleaning.

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