Antistatic solar cell front sheet and method for manufacturing the same

Abstract

This invention discloses an antistatic solar cell front panel, comprising at least a base film (10), which is bonded to a fluorocarbon resin protective film (30) by an adhesive (20). The base film (10) comprises at least one substrate layer (11) and two conductive layers (12). The conductive layers (12) are formed on both sides of the substrate layer (11) by vapor deposition or vacuum sputtering of a metallic conductive material. At least a portion of the edges of the base film (10) and the conductive layers (12) on its surface extend beyond the coverage of the adhesive (20) and the fluorocarbon resin protective film (30), so that the conductive layers (12) are in contact with the conductive support of the solar cell. By providing conductive layers on both sides of the substrate layer of the base film, the antistatic solar cell front panel of this invention can transfer interlayer static electricity of the front panel to the conductive support and finally conduct it away by exposing it outside the coverage of the adhesive and the fluorocarbon resin protective film, thereby avoiding the adverse effects of interlayer static electricity.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, and in particular to a front panel of a solar cell made of polymer composite materials, especially an antistatic solar cell front panel and its preparation method. Background Technology

[0002] Most solar cell front panels are made of glass, which has high strength and good light transmittance.

[0003] CN 103627227 B discloses a self-cleaning antireflective coating for solar glass and its production method. This prior art self-cleaning antireflective coating for solar glass uses polymeric silica as the main antireflective component, low-reflection titanium dioxide as an auxiliary antireflective component and photocatalyst, and antimony-doped tin dioxide, titanium phosphate, silicon phosphate, phosphoric acid, and antimony tin phosphate as self-cleaning synergists, antistatic agents, and antireflective film strengthening agents, using deionized water as the solvent. This prior art coats anatase titanium dioxide photocatalyst, antimony-doped tin dioxide antistatic agent, and other synergistic components onto a loose silica core generated by the hydrolysis of tetraethyl orthosilicate, in order to reduce the static electricity on the glass surface and the adsorption of dust.

[0004] Traditional glass front panels are prone to static electricity buildup due to friction and other factors, attracting dust particles and other contaminants. This accumulated static electricity cannot dissipate on the glass surface, potentially damaging solar cell modules due to improper handling and posing a fire hazard in outdoor environments. Furthermore, glass front panels are heavy and cannot withstand significant bending. Therefore, polymer materials are gaining increasing attention as alternatives to glass for front panels. Existing polymer composite front panels are generally transparent, made by combining fluorocarbon resin and a PET base film. Typically, to eliminate static electricity on the surface of these composite front panels, the approach is similar to that used for glass front panels: coating the fluorocarbon resin surface with a coating containing an antistatic agent.

[0005] However, the polymer composite front panel is a structure made of multiple layers of plastic films bonded together. The expansion rates of each layer differ, resulting in displacement and friction between the layers throughout the day during use. Therefore, unlike glass front panels where static electricity accumulates only on the surface, static electricity also accumulates between the layers of the composite front panel. Applying an antistatic coating to the surface of the composite front panel cannot eliminate this interlayer static electricity. Summary of the Invention

[0006] The technical problem to be solved by this application is to provide an antistatic solar cell front panel and a method for preparing the same, so as to reduce or avoid the problems mentioned above.

[0007] To address the aforementioned technical problems, this application proposes an antistatic solar cell front panel, comprising at least a base film, which is bonded to a fluorocarbon resin protective film using an adhesive. The base film comprises at least one substrate layer and two conductive layers, wherein the conductive layers are formed on both sides of the substrate layer by vapor deposition or vacuum sputtering of a metallic conductive material. At least a portion of the edges of the base film and its conductive layers extend beyond the coverage of the adhesive and the fluorocarbon resin protective film, thereby allowing the conductive layers to contact the conductive support of the solar cell.

[0008] Preferably, the substrate layer is composed of a polyester film containing or not containing an antistatic agent.

[0009] Preferably, the conductive layer partially covers the surface of the substrate layer.

[0010] Preferably, the conductive layer is formed on the surface of the substrate layer in the form of a mesh structure with holes.

[0011] Preferably, the grid lines of the grid structure are arranged along the gaps between the solar panels.

[0012] This application also proposes a method for preparing the above-mentioned antistatic solar cell front panel, comprising the following steps: providing a substrate layer, forming conductive layers on both sides of the substrate layer by vapor deposition or vacuum sputtering to obtain a base film; providing a fluorocarbon resin protective film, coating an adhesive on one side of the fluorocarbon resin protective film; covering one side of the fluorocarbon resin protective film with the adhesive coating onto one side of the base film, and ensuring that at least a portion of the edge of the base film and its conductive layer extends beyond the coverage area of ​​the adhesive and the fluorocarbon resin protective film; thereby preparing the antistatic solar cell front panel.

[0013] Preferably, the preparation method further includes the following step: partially masking the surface of the substrate layer to form a conductive layer that partially covers the surface of the substrate layer.

[0014] Preferably, the preparation method further includes the following steps: attaching a masking film corresponding to the shape of the conductive layer to the surface of the substrate layer, and forming a conductive layer in the gaps of the masking film by vapor deposition or vacuum sputtering.

[0015] The antistatic solar cell front panel of this application has conductive layers on both sides of the substrate layer of the base film. By exposing the area outside the adhesive and fluorocarbon resin protective film, the interlayer static electricity of the front panel can be transferred to the conductive support and finally discharged, thereby avoiding the adverse effects of interlayer static electricity. Attached Figure Description

[0016] The accompanying drawings are intended only to illustrate and explain this application and do not limit the scope of this application.

[0017] Figure 1 The diagram shown is a cross-sectional schematic of the front panel of an antistatic solar cell according to a specific embodiment of this application.

[0018] Figure 2 The diagram shown is an exploded perspective view of the front panel of an antistatic solar cell according to a specific embodiment of this application. Detailed Implementation

[0019] To provide a clearer understanding of the technical features, objectives, and effects of this application, specific embodiments are now described with reference to the accompanying drawings. Identical components are denoted by the same reference numerals.

[0020] Figure 1 A schematic diagram of an antistatic solar cell front panel is shown, comprising at least a base film 10, which is bonded to a fluorocarbon resin protective film 30 by an adhesive 20. The fluorocarbon resin protective film 30 faces the sun and provides excellent barrier properties and weather resistance. The base film 10 provides the supporting framework for the entire front panel. A weather-resistant coating or a protective layer (not shown) may be further applied to the inner side of the base film 10. The fluorocarbon resin includes, but is not limited to, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (FEVE), and / or polyvinyl fluoride (PVF). The adhesive 20 can be EVA adhesive commonly used in the photovoltaic field, or other thermosetting or UV-curable adhesives.

[0021] Furthermore, such as Figure 1 As shown, the base film 10 of this application includes at least one substrate layer 11 and two conductive layers 12. The conductive layers 12 are formed on both sides of the substrate layer 11 by vapor deposition or vacuum sputtering of a metallic conductive material. The substrate layer 11 is composed of a polyester film with or without an antistatic agent.

[0022] Since the conductive layers 12 disposed on both sides of the substrate layer 11 are a dense conductive structure formed by metallic conductive materials such as copper, aluminum, silver, and gold, their resistivity is much lower than that of the substrate layer 11 with added antistatic agent (when the substrate layer 11 contains antistatic agent). Therefore, even if the conductivity of the substrate layer 11 is uneven, the locally accumulated static electricity can be easily conducted away by the conductive layer 12, which has a resistivity of almost zero. Thus, the problem of uneven dispersion of the antistatic agent in the substrate layer 11 can be solved. Of course, even if the substrate layer 11 does not contain antistatic agent, the static electricity accumulated between the interlayer structures on its surface can also be easily conducted away by the conductive layer 12.

[0023] Furthermore, in Figure 1In another specific embodiment shown, at least a portion of the edge of the base film 10 and the conductive layer 12 on its surface extends beyond the coverage of the adhesive 20 and the fluorocarbon resin protective film 30, so that the conductive layer 12 can contact the conductive support of the solar cell (not shown in the figure). In the event of interlayer static electricity, it can be transmitted through the conductive layer 12 to the conductive support and finally conducted away, so as to avoid the adverse effects of interlayer static electricity.

[0024] In one specific embodiment of this application, the thickness of the substrate layer 11 is preferably 20-250 μm, and the thickness of the conductive layer 12 is preferably 10-100 nm. In a preferred embodiment, the conductive layer 12 is preferably formed by sputtering a transparent metal at a nanometer thickness, for example, by sputtering metallic silver or aluminum.

[0025] Wherein, if the substrate layer 11 contains an antistatic agent, the antistatic agent contained in the substrate layer 11 may be any one or more applicable antistatic agents in the prior art, including but not limited to nano-metal particles, metal wires, conductive graphite, carbon nanotubes, monoglycerides, sorbitan esters, ethoxyamines, polythiophene-type antistatic agents, polystyrene sulfonates, mixtures of compounds containing alkylene oxides and metal salts, etc.

[0026] The polyester constituting the substrate layer 11 of this application may be formed by polycondensation of a dicarboxylic acid and a diol, for example. For example, the dicarboxylic acid components include, but are not limited to, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 3,4'-diphenyl ether dicarboxylic acid, hexahydrophthalic acid, 2,7-naphthalenedicarboxylic acid, phthalic acid, 4,4'-methylenebisbenzoic acid, oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, 3-methyl adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, 1,11-undecanedicarboxylic acid, 1,10-decanedicarboxylic acid, undecanediic acid, 1,12-dodecanedicarboxylic acid, hexadecanediic acid, docosanodiic acid, tetradecanediic acid, dimer acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,1-cyclohexanediacetic acid, fumaric acid, maleic acid, and hexahydrophthalic acid. Furthermore, it can be used alone or in combination with two or more other acids. For example, the diol components include, but are not limited to, ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, glycol, diethylene glycol, triethylene glycol, poly(ethylene ether) glycol, and poly(butylene ether) glycol. Alcohols, branched diols, hexanediol or combinations thereof or their derivatives, 1,4-cyclohexanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-2,4-pentanediol, neopentanediol, 2-methyl-1,4-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,5-ethyl-1,3-hexanediol, 2,2-diethyl-1,3-propanediol, 1,3-hexanediol. Alternatively, they can be used alone or in combination of two or more.

[0027] The polyester constituting the substrate layer 11 of this application may also be formed from hydroxycarboxylic acids and their esterifying derivatives, or it may be formed from cyclic esters. For example, the hydroxycarboxylic acid components include, but are not limited to: lactic acid, citric acid, malic acid, tartaric acid, glycolic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, 4-hydroxycyclohexanecarboxylic acid, etc. The esterifying derivatives of the hydroxycarboxylic acids include, but are not limited to: dimethyl terephthalate, dimethyl isophthalate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl 3,4'-diphenyl ether dicarboxylate, dimethyl hexahydrophthalate, dimethyl 2,7-naphthalenedicarboxylate, dimethyl phthalate, dimethyl 4,4'-methylenebisbenzoate, dimethyl oxalate, dimethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, dimethyl azelaate, dimethyl 1,3-cyclohexanedicarboxylate, and dimethyl 5-sulfoisophthalate. Furthermore, they can be used alone or in combination. For example, the cyclic esters include, but are not limited to: ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide, lactide, etc. Furthermore, they can be used alone or in combination.

[0028] The polyester constituting the substrate layer 11 of this application is preferably polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, poly(1,4-cyclohexanediol) terephthalate, polyethylene naphthalate, polybutylene naphthalate, polypropylene naphthalate and copolymers thereof, particularly preferably polyethylene terephthalate (PET) and copolymers thereof.

[0029] The polyester constituting the substrate layer 11 of this application, taking PET as an example, is preferably manufactured as diethyl terephthalate through esterification or transesterification of terephthalic acid or dimethyl terephthalate and ethylene glycol, or industrially manufactured through polycondensation using a catalyst under high temperature and vacuum. In one specific embodiment, esterification can be performed using terephthalic acid, ethylene glycol, cyclohexanediol, a catalyst, and a heat stabilizer as raw materials; or esterification can be performed using terephthalic acid, ethylene glycol, isophthalic acid, a catalyst, and a heat stabilizer as raw materials. In another specific embodiment, the catalyst is any one of Ti / Si-based non-heavy metal catalysts and antimony trioxide, and its addition amount is 0.01% to 0.09% of the polyester mass. In another specific embodiment, the heat stabilizer is a phosphoric acid compound, and its addition amount is 0.0003% to 0.030% of the polyester mass; the phosphoric acid compound includes any one of phosphoric acid, phosphorous acid, polyphosphoric acid, trimethyl phosphate, triphenyl phosphate, and triethyl phosphate. Another specific embodiment of the polyester preparation method is as follows: 5.0 kg of terephthalic acid, 2.2 kg of ethylene glycol, and 1.10 g of germanium dioxide are added to a 20 L general-purpose polymerization reactor. An esterification reaction is carried out at 230–265 °C and 0.2–0.3 MPa (gauge pressure). When the water output reaches 1200 ml, the pressure is released to atmospheric pressure, and 1.025 g of triethyl phosphate is added. The mixture is stirred at atmospheric pressure for 10 minutes, then the temperature and pressure are raised and lowered to below 280 °C and 100 Pa. After the reaction is completed in 1–3 hours, the mixture is extruded, pelletized, and dried to obtain the polyester suitable for use as the substrate layer 11. Antistatic agents can be added at different stages of polyester preparation, such as the esterification stage or the polycondensation stage, to obtain a polyester with antistatic properties. The prepared polyester can be used to prepare a polyester film containing antistatic agents through melt extrusion and biaxial stretching processes, which can be used as the substrate layer 11 of this application. Alternatively, a polyester film suitable for use as the substrate layer 11 of this application can also be prepared directly from polyester without added antistatic agents.

[0030] Furthermore, because the conductive layer 12 formed on the surface of the substrate layer 11 is relatively dense, its surface adhesion is reduced, resulting in insufficient adhesion between the adhesive 20 and the conductive layer 12. To avoid reduced surface adhesion due to the conductive layer 12, the conductive layer 12 in this application is designed to partially cover the surface of the substrate layer 11, such as... Figure 2 As shown. Among them, in Figure 2 In the specific embodiment shown, the conductive layer 12 is formed on the surface of the substrate layer 11 in a mesh structure with holes 121. By partially covering the substrate layer 11, a portion of the surface is bonded to the adhesive 20, thereby avoiding the problem of reduced adhesion caused by the conductive layer 12, and improving antistatic properties while avoiding the defect of insufficient adhesive adhesion.

[0031] Furthermore, although the total area covered by the conductive layer 12 of the mesh structure is not large, it still has a certain impact on the light transmittance of the area covered by the mesh lines, reducing the overall power generation efficiency of the solar cell. To avoid this defect, it is preferable to arrange the mesh lines of the mesh structure along the gaps between the solar cell panels (not shown in the figure). These gaps are not originally used for power generation, so placing the mesh lines precisely at this position can eliminate the adverse effect of the mesh structure on power generation efficiency. Of course, the so-called arrangement along the gaps of the panels is a design based on the determined size and layout of the panels. When assembling the solar cell, aligning the prepared front panel according to the reference will ensure that the mesh lines of the conductive layer 12 are aligned and arranged in the gaps of the panels.

[0032] Furthermore, based on the structure of the antistatic solar cell front panel proposed in this application, this application also proposes a method for preparing the aforementioned antistatic solar cell front panel. Specifically, the preparation method of this application includes the following steps: providing a substrate layer 11, forming conductive layers 12 on both sides of the substrate layer 11 by vapor deposition or vacuum sputtering, and preparing a base film 10. The substrate layer 11 provided may or may not contain an antistatic agent.

[0033] Furthermore, the preparation method of this application may further include the following steps: providing a fluorocarbon resin protective film 30, coating one side surface of the fluorocarbon resin protective film 30 with an adhesive 20; covering one side surface of the base film 10 with the adhesive-coated side of the fluorocarbon resin protective film 30, and ensuring that at least a portion of the edge of the base film 10 and the conductive layer 12 on its surface extends outside the coverage area of ​​the adhesive 20 and the fluorocarbon resin protective film 30; thereby preparing the antistatic solar cell front panel of this application.

[0034] Furthermore, the preparation method of this application may further include the following steps: partially masking the surface of the substrate layer 11 to form a conductive layer 12 that partially covers the surface of the substrate layer 11. During evaporation or vacuum sputtering, metal vapor adheres to the entire surface of the substrate layer 11. In order to obtain... Figure 2 The structure of the conductive layer 12 shown requires the use of baffles or other structures to shield the parts where the conductive layer 12 does not need to be formed, so that the conductive layer 12 can be formed to partially cover the surface of the substrate layer 11.

[0035] In another specific embodiment of this application, the preparation method may further include the following steps: attaching a masking film (not shown in the figure) corresponding to the shape of the conductive layer 12 to the surface of the substrate layer 11; forming the conductive layer 12 in the gaps of the masking film by vapor deposition or vacuum sputtering; and forming the conductive layer 12 on the surface of the substrate layer 11 after removing the masking film. Figure 2The conductive layer 12 has a grid structure as shown. Compared with the baffle solution, the shielding film solution used in this embodiment can achieve continuous evaporation or sputtering of the entire substrate layer 11, which can greatly improve production efficiency. In contrast, the baffle solution can only form a part of the conductive layer 12 before proceeding to the next part of the production.

[0036] The masking film can be a structure composed of multiple block-shaped adhesive layers formed on a release film by die-cutting. In use, the masking film is placed on the surface of the substrate layer 11, and then the release film is peeled off, leaving the block-shaped adhesive layers on the surface of the substrate layer 11. After vapor deposition or sputtering, the adhesive layers are then removed from the surface of the substrate layer 11 with adhesive tape, leaving a conductive layer 12 with a mesh structure formed between the adhesive layers.

[0037] Figure 2 For clarity of display, the conductive layer 12 on the upper surface of the substrate layer 11 is not shown in dissection; only the conductive layer 12 on the lower surface of the substrate layer 11 is shown in dissection. Those skilled in the art should understand that the conductive layers 12 on both sides of the substrate layer 11 are actually identical and are tightly integrated with the substrate layer 11.

[0038] Those skilled in the art should understand that although this application is described by way of multiple embodiments, not every embodiment contains only one independent technical solution. This description is merely for clarity, and those skilled in the art should understand the specification as a whole and consider the technical solutions involved in each embodiment as being able to be combined with each other to form different embodiments to understand the scope of protection of this application.

[0039] The above description is merely an illustrative embodiment of this application and is not intended to limit the scope of this application. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of this application shall fall within the scope of protection of this application.

Claims

1. An antistatic solar cell front panel, comprising at least a base film (10), wherein the base film (10) is bonded integrally with a fluorocarbon resin protective film (30) by an adhesive (20); characterized in that, The base film (10) includes at least one substrate layer (11) and two conductive layers (12). The conductive layers (12) are formed on both sides of the substrate layer (11) by vapor deposition or vacuum sputtering of a metallic conductive material. At least a portion of the edges of the base film (10) and the conductive layers (12) on its surface extend beyond the coverage of the adhesive (20) and the fluorocarbon resin protective film (30) so that the conductive layers (12) are in contact with the conductive support of the solar cell.

2. The antistatic solar cell front panel as described in claim 1, characterized in that, The substrate layer (11) is composed of a polyester film with or without an antistatic agent.

3. The antistatic solar cell front panel as described in claim 2, characterized in that, The conductive layer (12) partially covers the surface of the substrate layer (11).

4. The antistatic solar cell front panel as described in claim 3, characterized in that, The conductive layer (12) is formed on the surface of the substrate layer (11) in a mesh structure with holes (121).

5. The antistatic solar cell front panel as described in claim 4, characterized in that, The grid lines of the grid structure are arranged along the gaps between the solar cell panels.

6. A method for preparing an antistatic solar cell front panel as described in any one of claims 1-5, comprising the following steps: providing a substrate layer (11), forming conductive layers (12) on both sides of the substrate layer (11) by vapor deposition or vacuum sputtering to obtain a base film (10); providing a fluorocarbon resin protective film (30), coating one side of the fluorocarbon resin protective film (30) with an adhesive (20); covering one side of the fluorocarbon resin protective film (30) with the adhesive coating on one side of the base film (10), and ensuring that at least a portion of the edges of the base film (10) and the conductive layer (12) on its surface extend beyond the coverage area of ​​the adhesive (20) and the fluorocarbon resin protective film (30); thereby preparing the antistatic solar cell front panel.

7. The preparation method according to claim 6, characterized in that, The preparation method further includes the following steps: partially masking the surface of the substrate layer (11) to form a conductive layer (12) that partially covers the surface of the substrate layer (11).

8. The preparation method according to claim 7, characterized in that, The preparation method further includes the following steps: attaching a masking film corresponding to the shape of the conductive layer (12) to the surface of the substrate layer (11), and forming the conductive layer (12) in the gaps of the masking film by vapor deposition or vacuum sputtering.

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