Gap reflective film joint tape, gap reflective film connection structure, and photovoltaic module

Abstract

A gap reflective film joint tape, a gap reflective film connection structure, and a photovoltaic module provided by the present application. The gap reflective film joint tape includes a glue film layer, a weather-resistant layer, a substrate layer, and an adhesive layer stacked in sequence. The gap reflective film joint tape provided by the present application can better bond two disconnected gap reflective films together, and at the same time has certain tensile strength, elongation, and anti-aging ability, and will not deform or slip when applied to a photovoltaic module, resulting in a gap between the two disconnected gap reflective films.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic technology, and particularly to an interstice reflective film joint tape, an interstice reflective film connection structure, and a photovoltaic module. Background Art

[0002] In recent years, in order to further develop and utilize solar energy and make full use of the effective use area in photovoltaic modules, people have developed an efficiency-enhancing material for photovoltaic modules, namely, a reflective film for photovoltaic modules. The reflective film can be divided into a solder ribbon reflective film and an interstice reflective film according to different uses. The mechanism of the reflective film to enhance efficiency is to make the light reflected to the outside of the photovoltaic module through the solder ribbon or the interstice between the cells in the photovoltaic module undergo total reflection at the glass-air interface of the photovoltaic module through the action of the reflective film, and then return to the cells again, thereby improving the output power of the photovoltaic module.

[0003] When the existing interstice reflective film is applied to a photovoltaic module, due to the limitation of the length of the interstice reflective film, two interstice reflective films need to be spliced and used. At present, the interstice reflective film joint tape used is an ordinary tape. In this way, harmful light, water vapor, etc. will enter the interior of the photovoltaic module through the position of the interstice reflective film joint tape, and the anti-ultraviolet requirement of the photovoltaic module cannot be met. In addition, the interstice reflective film joint tape on the market is generally relatively thick (most of the thickness is greater than 50 microns). After splicing two interstice reflective films, the thickness at the joint is inconsistent, and the appearance shows obvious concavity and convexity, which affects the appearance and increases the risk of cell cracking, etc., and also has a great negative impact on the service life and stable output of the power of the photovoltaic module. Summary of the Invention

[0004] In view of the above, it is necessary to provide an interstice reflective film joint tape capable of improving weather resistance and an interstice reflective film connection structure including the interstice reflective film joint tape.

[0005] In addition, it is also necessary to provide a photovoltaic module having the above interstice reflective film connection structure.

[0006] The present application provides an interstice reflective film joint tape, which includes a glue film layer, a weather-resistant layer, a substrate layer, and an adhesive layer stacked in sequence.

[0007] In some possible embodiments, the glue film layer is one or more of thermosetting polyethylene-vinyl acetate elastomer and polyethylene octene elastomer.

[0008] In some possible embodiments, both the glue film layer and the weather-resistant layer contain additives, and the additives include at least one of an ultraviolet light absorber and a light stabilizer.

[0009] In some possible embodiments, the weather-resistant layer further includes a film-forming resin, and the film-forming resin is selected from at least one of fluorocarbon resins, acrylate resins, polyurea elastomers, polyurethane resins, and epoxy resins.

[0010] In some possible embodiments, the adhesive layer includes any one of acrylic pressure-sensitive adhesives, silicone pressure-sensitive adhesives, and polyurethane pressure-sensitive adhesives.

[0011] In some possible embodiments, the substrate layer includes any one of biaxially oriented polypropylene films, uniaxially oriented polypropylene films, polyethylene films, and polyethylene terephthalate films.

[0012] The present application also provides a gap reflective film connection structure, which includes: a first gap reflective film, a second gap reflective film, and a gap reflective film joint tape. The first gap reflective film includes a first base layer and a first adhesive layer disposed on the first base layer, and the first base layer includes a first bonding area extending out of the first adhesive layer; the second gap reflective film includes a second base layer and a second adhesive layer disposed on the second base layer, and the second base layer includes a second bonding area extending out of the second adhesive layer. The edge of the first bonding area facing away from the first adhesive layer contacts the edge of the second bonding area facing away from the second adhesive layer. The side walls of the first adhesive layer, the side walls of the second adhesive layer, the first base layer, and the second base layer enclose an opening; the gap reflective film joint tape is disposed in the opening, and the gap reflective film joint tape is the gap reflective film joint tape as described above. The adhesive layer is disposed close to the first base layer and the second base layer to connect the first base layer and the second base layer, and the thickness of the gap reflective film joint tape is the same as the thicknesses of the first adhesive layer and the second adhesive layer.

[0013] In some possible embodiments, along the extension direction of the first gap reflective film, the size of the gap reflective film joint tape is the same as the size of the opening.

[0014] In some possible embodiments, along the extension direction of the first gap reflective film, the size of the first bonding area is 0.5 - 5 cm, and the size of the second bonding area is 0.5 - 5 cm.

[0015] The present application also provides a photovoltaic module, which includes a front plate and a rear plate stacked, at least two solar cells are disposed between the front plate and the rear plate, a gap is disposed between adjacent two solar cells, and the photovoltaic module further includes the gap reflective film connection structure as described above, and the gap reflective film connection structure is disposed corresponding to the gap.

[0016] Compared with the prior art, the gap reflective film joint tape provided by the present application adopts a multi-layer structure of a glue film layer, a substrate layer and an adhesive layer, and a weather resistance layer is added between the substrate layer and the glue film layer, effectively blocking the adverse effects of light and water vapor entering from the back plate of the photovoltaic module on the gap reflective film, improving the aging performance of the gap reflective film and having a longer service life. Using the above-mentioned gap reflective film joint tape can better bond two disconnected gap reflective films together, and at the same time has a certain tensile strength, elongation rate and anti-aging ability, and will not deform or slip when applied to the photovoltaic module, resulting in a gap between the two disconnected gap reflective films. During the aging process of the gap reflective film connection structure passed by the present application, there will be no abnormalities such as appearance bubbles and gaps, and at the same time, there will be no problems of yellowing and delamination, effectively improving the service life of the gap reflective film connection structure on the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. is a schematic structural diagram of a gap reflective film joint tape according to an embodiment of the present application.

[0018] Figure 2 FIG. is a schematic structural diagram of a gap reflective film connection structure according to an embodiment of the present application.

[0019] Figure 3 is Figure 2 a schematic diagram of the position of the gap reflective film connection structure shown in the photovoltaic module.

[0020] MAIN ELEMENT SYMBOL DESCRIPTION:

[0021]

[0022]

[0023] The following specific embodiments will further illustrate the embodiments of the present application in conjunction with the above drawings. SPECIFIC EMBODIMENTS

[0024] In order to more clearly understand the above-mentioned objects, features and advantages of the embodiments of the present application, the present application will be described in detail below in conjunction with the drawings and specific embodiments. It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0025] Many specific details are set forth in the following description in order to provide a thorough understanding of the embodiments of the present application. The described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments.

[0026] In this text, the "photovoltaic module" refers to a solar cell module formed by sealing a certain number of single solar cells in series and parallel. Since the output voltage of a single solar cell is relatively low, and the electrodes of an unpackaged cell are prone to falling off due to environmental influences, it is necessary to seal a certain number of single solar cells in series and parallel to form a solar cell module to prevent the cell electrodes and interconnections from being corroded. In addition, encapsulation also prevents the cells from breaking and facilitates outdoor installation. The quality of encapsulation determines the service life and reliability of the solar cell module.

[0027] Unless otherwise defined, all technical and scientific terms used in this text have the same meaning as commonly understood by those skilled in the technical field to which the embodiments of this application belong. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of this application.

[0028] Please refer to Figure 1 , this application provides a gap reflective film joint tape 10, which can be applied to connect two disconnected gap reflective films and is thus applied in photovoltaic modules. The gap reflective film joint tape 10 is a multi-layer composite structure, sequentially including an adhesive film layer 1, a weather-resistant layer 2, a substrate layer 3, and an adhesive layer 4.

[0029] The gap reflective film joint tape 10 designed in this application has a weather-resistant layer 2 disposed between the substrate layer 3 and the adhesive film layer 1. The weather-resistant layer 2 itself can withstand 200 kWh without yellowing, effectively protecting the substrate layer 3 and the adhesive layer 4 from aging and yellowing and embrittlement due to ultraviolet light irradiation, preventing the adhesive layer 4 from failing and causing the gap reflective film joint tape 10 to fall off. It effectively blocks the light and water vapor entering the substrate layer 3 and the adhesive layer 4 from the back plate of the photovoltaic module, reduces the adverse effects of reflected light and water vapor on the gap reflective film joint tape 10, improves the aging performance of the gap reflective film joint tape 10, avoids the failure and delamination of the gap reflective film joint tape 10, and increases the service life. At the same time, the weather-resistant layer 2 also has a certain light reflection effect, reflecting the light irradiated on the back of the gap reflective film back to the cell area, thereby enhancing the output power of the photovoltaic module.

[0030] In one embodiment, the weather-resistant layer 2 includes a film-forming resin and the light-reflecting material mixed in the film-forming resin. Among them, the film-forming resin is used to block the water vapor passing through the adhesive film layer 1. The film-forming resin is also used to bond the light-reflecting materials together and enable the weather-resistant layer 2 to be bonded to the substrate layer 3. The light-reflecting material is used to reflect the light passing through the adhesive film layer 1, thereby blocking the light passing through the adhesive film layer 1. Among them, the light reflectivity of the weather-resistant layer 2 in the wavelength range of 200 - 1100 nm is 50% - 100%.

[0031] In one embodiment, the film-forming resin may be selected from at least one of fluorocarbon resins, acrylate resins, polyurea elastomers, polyurethane resins, and epoxy resins. Preferably, the fluorocarbon resin may be selected from at least one of polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, perfluoroethylene-propylene copolymer, chlorotrifluoroethylene-vinyl ether resin, chlorotrifluoroethylene-vinyl ester resin, polyvinylidene fluoride resin, and polyvinylidene fluoride-tetrafluoroethylene-hexafluoroisopropylene resin. The polyurethane resin may be selected from at least one of polyether-type polyurethane, polyester-type polyurethane, and polycarbonate-type polyurethane. The epoxy resin refers to an organic compound having at least one epoxy group (ethylene oxide ring), and may be selected from at least one of aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, glycidyl ester-type epoxy resins, glycidyl amine-type epoxy resins, and glycidyl acrylate-type epoxy resins, etc.

[0032] In one embodiment, the light-reflecting material may include at least one of titanium dioxide powder, glass beads, and metal powder. Among them, the metal powder may be aluminum powder or silver powder.

[0033] In one embodiment, the film-forming resin is a fluorocarbon resin, and the light-reflecting material is titanium dioxide powder (i.e., titanium white). Among them, the fluorocarbon resin has a low water vapor absorption rate, which is beneficial to improving the water vapor barrier effect of the film-forming resin. The titanium dioxide powder helps to enhance the diffuse reflection and improve the ability of the weather-resistant layer 2 to receive light. Especially under the use conditions of double glass (i.e., both the front plate and the rear plate of the photovoltaic module are flat glass), the weather-resistant layer 2 has a good reflection effect on the light entering from the rear plate, and the double-sided gain effect of the photovoltaic module is prominent. When the light-reflecting material is titanium dioxide powder, the weather-resistant layer 2 appears white in appearance. According to the different contents of titanium dioxide powder, the weather-resistant layer 2 can have a matte or bright appearance.

[0034] In one embodiment, the weather-resistant layer 2 further includes an additive mixed in the film-forming resin, and the additive includes at least one of an ultraviolet light absorber and a light stabilizer. Among them, the ultraviolet light absorber has the function of absorbing ultraviolet light, and the light stabilizer also has the function of shielding or absorbing ultraviolet light. Therefore, it can reduce the incident amount and intensity of ultraviolet light entering the substrate layer 3 and the adhesive layer 4 from the rear plate of the photovoltaic module, improve the problems of yellowing and embrittlement of the substrate layer 3 and the adhesive layer 4 under the long-term action of ultraviolet light, help to enhance the gain, and ensure the effectiveness of the gap reflective film joint tape 10.

[0035] In one embodiment, the thickness of the weather-resistant layer 2 is 1 micron to 20 microns. Among them, the thickness of the weather-resistant layer 2 should not be too large or too small. When the thickness of the weather-resistant layer 2 is too small, the weather-resistant layer 2 cannot play the role of blocking water vapor and light; when the thickness of the weather-resistant layer 2 is too large, it affects the uniformity of the weather-resistant layer 2 and increases the material cost of the product.

[0036] The adhesive layer 4 is used to bond different gap reflective films together. The main adhesives of the adhesive layer 4 are acrylic, silicone, and polyurethane pressure-sensitive adhesives. It has high bonding strength and excellent weather resistance, and can improve the bonding strength between different gap reflective films.

[0037] In one embodiment, an auxiliary agent is added to the main adhesive of the adhesive layer 4. The auxiliary agent includes at least one of an ultraviolet light absorber and a light stabilizer. Specifically, it is an ultraviolet light absorber. The ultraviolet light absorber has the function of absorbing ultraviolet light, and the light stabilizer also has the function of shielding or absorbing ultraviolet light. Therefore, it can improve the problem of yellowing and embrittlement of the adhesive layer 4 under the long-term action of ultraviolet light, help to improve the bonding strength of the adhesive layer 4, avoid aging and loss of adhesion of the adhesive layer 4, and delamination, and ensure the effectiveness of the gap reflective film joint tape 10.

[0038] The adhesive film layer 1 is used to bond the gap reflective film joint tape 10 to the back plate of the photovoltaic module. The material of the adhesive film layer 1 is a polymer material with good bonding performance, such as one or several of thermosetting ethylene-vinyl acetate (EVA) elastomer, polyethylene octene (POE) elastomer, etc.

[0039] In one embodiment, an auxiliary agent is also added to the adhesive film layer 1. The auxiliary agent includes at least one of an ultraviolet absorber and a light stabilizer. The addition amount of the ultraviolet absorber is less than or equal to 2.0% of the total mass of the adhesive film layer 1. The incorporation of the ultraviolet absorber into the adhesive film layer 1 enables the adhesive film layer 1 to absorb ultraviolet light, which can reduce the amount and intensity of light incident on the weather-resistant layer 2 from the back plate, and helps to improve the gain.

[0040] The substrate layer 3 is made of a polymer material and mainly plays a supporting role. In one embodiment, the substrate layer 3 is prepared from any one of biaxially oriented polypropylene film (BOPP), uniaxially oriented polypropylene (OPP) film, polyethylene (PE) film, and polyethylene terephthalate material (PET).

[0041] In one embodiment, the surface of the adhesive layer 4 is protected by a release film 5. Specifically, the thickness of the release film 5 is 70 - 120 microns. The release agent is coated on the surface layer of environmentally friendly materials such as PET, PE, and OPP films. The release film 5 is used to protect the adhesive layer 4 and at the same time plays a supporting role.

[0042] Please refer to Figure 2The present application provides a gap reflective film connection structure 100, the gap reflective film connection structure 100 includes a first gap reflective film 20, a second gap reflective film 30 and the gap reflective film joint tape 10 as described above. The first gap reflective film 20 includes a first base layer 21 and a first adhesive layer 22 disposed on the first base layer 21, the first base layer 21 includes a first adhesive area 23 extending out of the first adhesive layer 22. The second gap reflective film 30 includes a second base layer 31 and a second adhesive layer 32 disposed on the second base layer 31, the second base layer 31 includes a second adhesive area 33 extending out of the second adhesive layer 32, the edge of the first adhesive area 23 away from the first adhesive layer 22 is in contact with the edge of the second adhesive area 33 away from the second adhesive layer 32, and the side wall of the first adhesive layer 22, the side wall of the second adhesive layer 32, the first base layer 21 and the second base layer 31 are surrounded by an opening 40. The gap reflective film joint tape 10 is arranged in the opening 40, the adhesive layer 4 is arranged close to the first base layer 21 and the second base layer 31 to connect the first base layer 21 and the second base layer 31, and the thickness of the gap reflective film joint tape 10 is consistent with the thickness of the first adhesive layer 22 and the second adhesive layer 32.

[0043] Along the extension direction of the first gap reflective film 20, the size of the gap reflective film joint tape 10 is consistent with the size of the opening 40. Filling the opening 40 with the gap reflective film joint tape 10 can improve the tensile strength of the joint between the first gap reflective film 20 and the second gap reflective film 30 to be greater than 40MPa, the elongation at break ≥60%, and the anti-ultraviolet aging ability to be ultraviolet 90kWh, the yellowing less than 2, and no deformation or slippage will occur when applied to the photovoltaic module to cause a gap at the joint.

[0044] In one embodiment, along the extension direction of the first gap reflective film 20, the size of the first adhesive area 23 is 0.5-5 cm, and the size of the second adhesive area 33 is 0.5-5 cm. Therefore, the length of the gap reflective film joint tape 10 is approximately 1-10 cm.

[0045] In one embodiment, along the extension direction of the first gap reflective film 20, the size of the first adhesive area 23 is 1-1.5 cm, and the size of the second adhesive area 33 is 1-1.5 cm. Therefore, the length of the gap reflective film joint tape 10 is approximately 2-3 cm.

[0046] By controlling the thickness of the gap reflective film joint tape 10, the thickness of the gap reflective film connection structure 100 after connection can be ensured to be uniform, especially there will be no bumps at the joint, thereby improving the appearance and use effect of the overall gap reflective film connection structure 100.

[0047] Please refer to Figure 3 Figure 3 , an embodiment of the present application also provides a photovoltaic module 200, which includes a front plate 201 and a rear plate 202 arranged in a stacked manner. There are more than two solar cells 203 provided between the front plate 201 and the rear plate 202. A gap 206 is provided between two adjacent solar cells 203. A front encapsulation adhesive material 204 is provided between the solar cell 203 and the front plate 201, and a rear encapsulation adhesive material 205 is provided between the solar cell 203 and the rear plate 202. A gap reflective film connection structure 100 is provided between the rear encapsulation adhesive material 205 and the rear plate 202, and the gap reflective film connection structure 100 is arranged corresponding to the gap 206 between two adjacent solar cells 203.

[0048] In one embodiment, the width and length of the gap reflective film connection structure 100 are greater than or equal to the width and length of the gap 206.

[0049] In one embodiment, the front plate 201 is a planar glass, and the rear plate 202 can be a planar glass, that is, the photovoltaic module 200 is a double-glass module.

[0050] In one embodiment, the solar cells 203 between the front plate 201 and the rear plate 202 can be one layer or multiple layers, and the multiple solar cells 203 are encapsulated with an encapsulation adhesive material. Correspondingly, the gap reflective film connection structure 100 can be correspondingly arranged to correspond to the gap between a certain layer of solar cells 203.

[0051] In one embodiment, the bonding strengths of the first adhesive layer 22, the second adhesive layer 32 and the adhesive film layer 1 are substantially the same. The adhesive film layer 1 and the first adhesive layer 22, the second adhesive layer 32 can use the same main adhesive.

[0052] In one embodiment, the first adhesive layer 22 and the second adhesive layer 32 also contain a light-reflecting material to improve the light-reflecting effect of the gap reflective film connection structure 100, thereby improving the output power of the photovoltaic module.

[0053] The first adhesive layer 22 and the second adhesive layer 32 further include at least one of an ultraviolet absorber and a light stabilizer. The ultraviolet absorber has the function of absorbing ultraviolet light, and the light stabilizer also has the function of shielding or absorbing ultraviolet light. Therefore, it can improve the problems of yellowing and embrittlement of the gap reflective film connection structure 100 under the long-term action of ultraviolet light, avoid aging and loss of adhesion, delamination, and ensure the effectiveness of the gap reflective film connection structure 100.

[0054] In the photovoltaic module 200, by adding the gap reflective film connection structure 100, the service life of the photovoltaic module in the double-glass module can be effectively improved, the output power of the photovoltaic module 200 can be increased, and at the same time, the light irradiated on the back of the gap reflective film connection structure 100 is reflected back to the cell area again, thereby increasing the output power of the photovoltaic module 200.

[0055] The above embodiments are only used to illustrate the technical solutions of the embodiments of the present application and not to limit them. Although the embodiments of the present application have been described in detail with reference to the above preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the embodiments of the present application can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A gap reflective film connection structure, It is characterized in that include: The first gap reflective film comprises a first base layer and a first adhesive layer disposed on the first base layer, wherein the first base layer comprises a first adhesive region extending out of the first adhesive layer; The second gap reflective film comprises a second base layer and a second adhesive layer disposed on the second base layer, the second base layer comprises a second adhesive region extending out of the second adhesive layer, an edge of the first adhesive region away from the first adhesive layer contacts an edge of the second adhesive region away from the second adhesive layer, and a side wall of the first adhesive layer, a side wall of the second adhesive layer, the first base layer and the second base layer surround an opening; The gap reflective film joint tape is arranged in the opening, and the gap reflective film joint tape includes a film layer, a weather-resistant layer, a base material layer and an adhesive layer stacked in sequence. The adhesive layer is arranged close to the first base layer and the second base layer to connect the first base layer and the second base layer. The thickness of the gap reflective film joint tape is consistent with the thickness of the first adhesive layer and the second adhesive layer.

2. The gap reflective film connection structure according to claim 1, It is characterized in that The adhesive film layer is one or more of thermosetting polyethylene-vinyl acetate elastomer and polyethylene octene elastomer.

3. The gap reflective film connection structure according to claim 1, It is characterized in that The adhesive film layer and the weather-resistant layer both contain auxiliary agents, and the auxiliary agents include at least one of an ultraviolet light absorber and a light stabilizer.

4. The gap reflective film connection structure according to claim 3, It is characterized in that The weather-resistant layer further comprises a film-forming resin, and the film-forming resin is selected from at least one of fluorocarbon resin, acrylic resin, polyurea elastomer, polyurethane resin and epoxy resin.

5. The gap reflective film connection structure according to claim 1, It is characterized in that The adhesive layer includes any one of acrylic pressure-sensitive adhesive, silicone pressure-sensitive adhesive and polyurethane pressure-sensitive adhesive.

6. The gap reflective film connection structure according to claim 1, It is characterized in that The substrate layer includes any one of a biaxially oriented polypropylene film, a uniaxially oriented polypropylene film, a polyethylene film and a polyethylene terephthalate film.

7. The gap reflective film connection structure according to claim 1, It is characterized in that Along the extension direction of the first gap reflective film, the size of the gap reflective film joint tape is consistent with the size of the opening.

8. The gap reflective film connection structure according to claim 7, It is characterized in that Along the extension direction of the first gap reflective film, the size of the first bonding area is 0.5-5 cm, and the size of the second bonding area is 0.5-5 cm.

9. A photovoltaic module, comprising a front plate and a rear plate stacked in layers, at least two solar cells are arranged between the front plate and the rear plate, and a gap is arranged between two adjacent solar cells. It is characterized in that The photovoltaic assembly further comprises a gap reflective film connection structure as described in any one of claims 1 to 8, and the gap reflective film connection structure is arranged corresponding to the gap.

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