Coating type water-oxygen barrier photovoltaic backboard

Abstract

The utility model relates to the technical field of photovoltaic backboards, in particular to a coating type water-oxygen barrier photovoltaic backboard, which comprises a weather-proof layer, a first water-blocking layer, a base material, a second water-blocking layer, an oxygen-blocking layer and a water-absorbing layer which are sequentially stacked. The first waterproof layer and the second waterproof layer are made of a resin matrix and a layered silicate material; the base material is made of one or more of PET (polyethylene terephthalate), PE (polyethylene), BOPP (biaxially-oriented polypropylene) and PI (polyimide); the material of the oxygen barrier layer comprises a resin matrix and modified layered zirconium phosphate; and the water absorption layer is made of a water-absorbent resin matrix and a water absorbent. According to the coating type water-oxygen barrier photovoltaic backboard prepared by the utility model, the insulating flexible organic material and the layered inorganic material are compounded to form the coating, so that on one hand, the photovoltaic backboard has good barrier performance, and on the other hand, the backboard has good insulating performance and flexibility, is not easy to crack and is durable; and the service life of the photovoltaic backboard is greatly prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic back panels, and in particular to a coated water and oxygen barrier photovoltaic back panel. Background Art

[0002] As a green energy source, solar cells are in line with the strategy of sustainable development and have received extensive attention and research. However, direct contact of solar cells with oxygen and water vapor can easily lead to performance degradation, thus affecting the product life. Therefore, it is necessary to set up isolation measures on the surface and back of solar panels to extend the battery life. Generally speaking, solar panels include five layers: photovoltaic glass, EVA, solar cells, EVA and photovoltaic backboard. Photovoltaic backboards are also called solar cell backboard films, solar cell backboards, photovoltaic backboard films, and solar backboards, and are widely used in solar cell (photovoltaic) modules. Photovoltaic backboards are set on the back of solar panels and mainly play the role of protecting and supporting the cells. They must have good insulation, barrier and weather resistance. Photovoltaic backboards with high water and oxygen barrier capabilities are conducive to protecting the cells and extending the product life.

[0003] The existing technology improves the water and oxygen barrier capacity of the backplane by adding a metal layer, evaporating an inorganic oxide layer, and compounding multiple functional materials. For example, the photovoltaic backplane disclosed in patent CN111002663A achieves a barrier effect through a composite aluminum foil layer, but this method will reduce the insulation performance of the backplane. The photovoltaic backplane disclosed in patent CN216250757U improves the barrier effect by evaporating an inorganic layer, but this method is not only costly, but also its coating is an inorganic coating, lacks flexibility, is prone to cracks, and the water vapor barrier ability is easily lost. The water and oxygen barrier photovoltaic backplane obtained by compounding multiple functional materials is prone to delamination after long-term use, affecting the long-term reliability of photovoltaic modules. Utility Model Content

[0004] In order to solve the above problems, based on the existing photovoltaic backsheet, the utility model provides a coated water and oxygen barrier photovoltaic backsheet.

[0005] The utility model solves the problems existing in the prior art through the following technical solutions:

[0006] The utility model provides a coated water-oxygen barrier photovoltaic back sheet, comprising a weather-resistant layer, a first water-blocking layer, a substrate, a second water-blocking layer, an oxygen-blocking layer and a water-absorbing layer which are stacked in sequence; the oxygen-blocking layer is a modified zirconium phosphate coating.

[0007] Furthermore, the modified zirconium phosphate coating is obtained by curing after coating an oxygen-barrier coating liquid containing modified zirconium phosphate, and has a thickness of 1-3 μm; in terms of mass percentage, the oxygen-barrier coating liquid includes the following components: 50%-70% PVA resin, 10-20% modified zirconium phosphate dispersion, and 20%-30% deionized water.

[0008] Furthermore, the first water-blocking layer is a layered silicate coating with a thickness of 2-6 μm; the second water-blocking layer is a layered silicate coating with a thickness of 2-6 μm.

[0009] Furthermore, the layered silicate coating is obtained by curing after coating a water-blocking coating liquid containing layered silicate; the water-blocking coating liquid includes the following components in percentage by mass: 5%-40% acrylate oligomer, 1%-8% acrylic acid monomer, 0.5%-2% photoinitiator, 0.05%-0.5% auxiliary agent, 60%-80% solvent, and 2%-10% layered silicate.

[0010] Furthermore, the material of the weather-resistant layer is fluorocarbon resin, and further, includes FEVE and PVDF, and has a thickness of 1-3 μm.

[0011] Furthermore, the substrate is one or more of PET, PE, BOPP, and PI, and has a thickness of 30-300 μm.

[0012] Furthermore, the water-absorbing layer is a cellulose ether-sodium polyacrylate composite coating with a thickness of 1-3 μm.

[0013] Furthermore, the cellulose ether-sodium polyacrylate composite coating is obtained by coating and curing a cellulose ether-sodium polyacrylate composite coating solution; in terms of mass percentage, the cellulose ether-sodium polyacrylate composite coating solution comprises: 1%-5% cellulose ether, 1%-5% sodium polyacrylate, and 90%-98% deionized water.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] 1. The coated water and oxygen barrier photovoltaic backplane prepared by the utility model adopts an insulating flexible organic material and a layered inorganic material to form a coating. On the one hand, the photovoltaic backplane has good insulation performance and flexibility, is not easy to crack, and is durable, which greatly extends the effective service life of the photovoltaic backplane; on the other hand, at the same time, the layered inorganic material has a large diameter-to-thickness ratio, and the "brick and mud" structure formed in the resin matrix can increase the penetration path of small molecules, thereby improving the water and oxygen barrier ability of the backplane.

[0016] 2. The coated water-oxygen barrier photovoltaic backplane prepared by the utility model has an oxygen barrier layer formed by wet coating of an oxygen barrier coating liquid on a second water barrier layer and curing. Compared with direct coating on a substrate, it has better wettability, better film-forming properties, and better adhesion of the coating after curing. The oxygen barrier capacity of the PVA material decreases in a high humidity environment. The first water barrier layer and the second water barrier layer are arranged outside the oxygen barrier layer containing the PVA material, which can protect the oxygen barrier layer from the influence of the high humidity environment. The water absorption layer is arranged to face the content side, which can not only absorb the original water vapor in the air on the content side, but also absorb the water vapor that penetrates from the external environment, thereby further improving the water vapor barrier capacity of the barrier film and extending the life of the content solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic structural diagram of the coated water and oxygen barrier photovoltaic back sheet of the utility model.

[0019] Among them: 1-substrate, 2-first water-blocking layer, 3-weather-resistant layer, 4-second water-blocking layer, 5-oxygen-blocking layer, 6-water-absorbing layer. DETAILED DESCRIPTION

[0020] The following will be combined with specific embodiments to clearly and completely describe the technical solution of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the utility model.

[0021] Example 1

[0022] This embodiment provides a coated water-oxygen barrier photovoltaic backsheet of the present invention, comprising a weather-resistant layer 3, a first water-blocking layer 2, a substrate 1, a second water-blocking layer 4, an oxygen-blocking layer 5 and a water-absorbing layer 6; the oxygen-blocking layer is a modified zirconium phosphate coating.

[0023] The material of the substrate 1 is one or more of PET, PE, BOPP, and PI. In this embodiment, PET with a polyurethane primer is used, and the film thickness is 30-300 μm (preferably 180 μm). In some preferred embodiments, the substrate 1 can be primed or corona treated.

[0024] The first water-blocking layer 2 and the second water-blocking layer 4 are respectively formed on both sides of the substrate 1, and the film thickness is 2-6 μm (preferably 3 μm). The first water-blocking layer 2 and the second water-blocking layer 4 are formed by curing a water-blocking coating liquid prepared by 5%-40% acrylate oligomer, 1%-8% acrylic acid monomer, 0.5%-2% photoinitiator, 0.05%-0.5% auxiliary agent, 60%-80% solvent, and 2%-10% layered silicate. The acrylate oligomer is selected from any one or more of polyurethane acrylate oligomer, epoxy acrylate oligomer, polyester acrylate oligomer, amino acrylate oligomer, and polyether acrylate oligomer; the acrylic monomer is selected from ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate, dicyclopentenyl acrylate, trimethylolpropane ethoxy triacrylate, tricyclodecane dimethanol diacrylate, dipentaerythritol hexaacrylate, pentaerythritol triacrylate, tri- The invention comprises one or more of propylene glycol diacrylate; the photoinitiator is selected from one or more of 1-hydroxycyclohexyl phenyl ketone, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, 2-isopropylthioxanthone, 2,2-dimethoxy-2-phenylacetophenone and camphorquinone; the auxiliary agent is selected from one or more of polysiloxane, polyether siloxane copolymer, styrene maleic anhydride copolymer and polyacrylate; the solvent is selected from one or more of ethyl acetate, butyl acetate, acetone, ethanol and isopropanol. In this embodiment, the first water-blocking layer 2 and the second water-blocking layer 4 are water-blocking coating liquids prepared from 25% polyurethane acrylate oligomer, 5% ethoxylated trimethylolpropane triacrylate, 1.5% diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, 0.3% styrene maleic anhydride copolymer, 75% ethyl acetate, and 8% natural mica, which are respectively coated on both sides of the substrate 1 with a 25 μm wire rod and cured by irradiating with ultraviolet light with a power of 600 W for 15 seconds. In other embodiments, the materials of the first water-blocking layer 2 and the second water-blocking layer 4 can be completely the same or different, and the thicknesses of the first water-blocking layer 2 and the second water-blocking layer 4 can be the same or different, which can be adjusted according to actual needs.

[0025] The weather-resistant layer 3 is formed on the other surface of the first water-blocking layer 2, and the film thickness is 1-3μm (preferably 2μm), and it is made of fluorocarbon resin. Specifically, PVDF resin can be coated on the other surface of the first water-blocking layer 2 with a 25μm wire rod, and the weather-resistant layer 3 can be obtained after thermal curing.

[0026] The oxygen barrier layer 5 is formed on the other surface of the second water barrier layer 4, and the film thickness is 1-3μm (preferably 2μm), which is formed by curing the oxygen barrier coating liquid containing modified zirconium phosphate. Specifically, PVA powder can be dispersed in deionized water, stirred at room temperature for 10 minutes, heated to 95°C and stirred for 1 hour, and cooled to room temperature to obtain PVA resin; α-zirconium phosphate and tromethamine are dispersed in deionized water, and high-speed stirring or ultrasonication is performed for 10-20 minutes to obtain a modified zirconium phosphate dispersion; 60% PVA resin, 25% deionized water, and 15% modified zirconium phosphate dispersion (mass concentration is 5%) are mixed to obtain an oxygen barrier coating liquid; the oxygen barrier coating liquid is applied to the other surface of the second water barrier layer 4 with a 25μm wire rod, and dried at 60°C for 15 minutes to obtain the oxygen barrier layer 5.

[0027] The water-absorbing layer 6 is formed on the other surface of the oxygen barrier layer 5, and the film thickness is 1-3 μm (preferably 2 μm). Specifically, a cellulose ether-sodium polyacrylate composite coating liquid obtained by mixing 3% cellulose ether, 3% sodium polyacrylate, and 94% deionized water can be evenly dispersed to obtain a water-absorbing coating liquid; the water-absorbing coating liquid is coated on the surface of the oxygen barrier layer 5 with a 25 μm wire rod, and cured in a 60° C. oven for 10-20 minutes to obtain the water-absorbing layer 6.

[0028] The coated water-oxygen barrier photovoltaic backplane prepared by the utility model adopts an insulating flexible organic material as a coating, which, on the one hand, makes the photovoltaic backplane have good insulation performance, and on the other hand, the organic material adopted has good flexibility, is not easy to crack, and is durable, which greatly extends the effective service life of the photovoltaic backplane. The coated water-oxygen barrier photovoltaic backplane prepared by the utility model, the oxygen barrier layer 5 is formed by the oxygen barrier coating liquid being wet-coated on the second water barrier layer 4 and solidified, and has better coating liquid wettability and film-forming ability than when it is directly coated on the substrate 1, and the adhesion of the coating after curing is better; the oxygen barrier ability of the PVA material decreases in a high humidity environment, and the first water barrier layer 2 and the second water barrier layer 4 are arranged outside the oxygen barrier layer 5 containing the PVA material, which can protect the oxygen barrier layer 5 from being affected by the high humidity environment; the water absorption layer 6 is arranged to face the content side, which can not only absorb the original water vapor in the air on the content side, but also absorb the water vapor that penetrates from the external environment, further improving the water vapor barrier ability of the barrier film and extending the life of the content. The coated water-oxygen barrier photovoltaic back sheet prepared by the utility model has good weather resistance and is applied to the packaging of solar cells to reduce the contact of photovoltaic modules with water vapor and oxygen, thereby extending the product life of solar cells.

[0029] The utility model is further described above with the help of specific embodiments, but it should be understood that the specific description here should not be construed as a limitation on the essence and scope of the utility model. Various modifications made to the above embodiments by ordinary technicians in this field after reading this specification are all within the scope of protection of the utility model.

Claims

1. A coated water and oxygen barrier photovoltaic backsheet, characterized in that: It comprises a weather-resistant layer, a first water-blocking layer, a substrate, a second water-blocking layer, an oxygen-blocking layer and a water-absorbing layer which are stacked in sequence; The oxygen barrier layer is a modified zirconium phosphate coating with a thickness of 1-3 μm; The first water-blocking layer is a layered silicate coating with a thickness of 2-6 μm; The second water-blocking layer is a layered silicate coating with a thickness of 2-6 μm.

2. The coated water and oxygen barrier photovoltaic backsheet according to claim 1, characterized in that: The weather-resistant layer is made of fluorocarbon resin and has a thickness of 1-3 μm.

3. The coated water and oxygen barrier photovoltaic backsheet according to claim 1, characterized in that: The substrate is one of PET, PE, BOPP and PI, and has a thickness of 30-300 μm.

4. The coated water and oxygen barrier photovoltaic backsheet according to claim 1, characterized in that: The water-absorbing layer is a cellulose ether-sodium polyacrylate composite coating with a thickness of 1-3 μm.

Images