Exterior materials with solar panels

Abstract

To provide a solar cell mounted exterior material that facilitates the replacement of film-type solar cells after the period of service.SOLUTION: A solar cell-mounted exterior material 1 is provided with: an exterior material substrate 3 made of a metal plate, the outdoor surface of which in the installed state is either bare metal, plated, resin-coated, or film-laminated; and a film-type solar cell 5 attached to be integrated with the outdoor surface of the exterior material substrate 3 in the installed state. The film-type solar cell 5 is bonded to the exterior material substrate 3 so that it can be easily peeled off.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a metal exterior material for a structure, and particularly to an exterior material with a film-type solar cell integrated with an exterior material substrate. The exterior material with a solar cell mounted herein means that, for example, in a state of being arranged as an exterior material of a building structure, a film-type solar cell is mounted on the exterior material substrate, and it only needs to be mounted at the time of completion, regardless of whether it is mounted at the time of shipping of the exterior material or mounted by construction work.

Background Art

[0002] Towards carbon neutrality in 2050, the spread of solar power generation is expected. However, suitable sites for constructing large-scale solar power plants are decreasing, and while installation on buildings etc. is required, there are also technical problems such as that it is not easy to install on existing houses and buildings with a small roof load-bearing capacity, or on the walls of houses and buildings.

[0003] Regarding the installation of solar cells on buildings, first, there are methods such as installing a crystalline solar cell panel on a rooftop by installing a pedestal, or a type in which a solar cell is built into a roofing material. Also, other than on rooftops, film-type solar cells typified by visible light transmissive organic thin film solar cells (hereinafter, OPV) are pasted on glass or sandwiched between glasses and used.

[0004] The schematic configuration of a film-type solar cell is such that a power generation layer is covered with resin-made protective films on the front and back, and some of the front and back films are joined by heat fusion or (after surface modification of the joining surface,) a hot melt adhesive. Whether for new construction or existing construction, when using crystalline solar cells, there is a problem that the weight including the pedestal increases, but film-type solar cells are lightweight and only need to be pasted on an exterior material, and various devices have been made.

[0005] Patent Document 1 discloses a metal vertical roofing material in which a solar cell and a terminal box housing are formed are integrated with elastic adhesive applied at multiple points at predetermined intervals. In this material, the gaps between the elastic adhesives between the solar cell and the metal vertical roofing material are formed to communicate in the direction of the roof's slope. Solar cells are attached to the grooved and sloped sections of the metal vertical roofing material. To reduce costs and improve ease of installation, this material provides metal vertical roofing material with solar cells that does not require mounting frames or brackets.

[0006] Patent Document 2 discloses a back surface protective sheet for solar cell modules, which has heat-sealable resin layers with different melting points on the front and back surfaces of a base resin layer, with the melting point on the back surface being lowered and the module being integrated with a building material. By lowering the melting point on the back surface, the heat-sealable resin layer on the power generation layer side is not melted during the integration process with the building material, thereby joining the heat-sealable resin layer on the back surface to the building material.

[0007] Patent Document 3 discloses a composite structure for an integrated solar cell in which a flexible solar cell and a substrate (building material) are bonded together by an acrylic foam coated with an acrylic adhesive on both sides, i.e., double-sided tape. It also states that the flexible solar cell sheet has a 90-degree peel-off adhesive strength of 15N or more per 10mm of substrate. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2018-199979 [Patent Document 2] Japanese Patent Publication No. 2019-161038 [Patent Document 3] Utility Model Registration No. 3164871 Gazette [Overview of the project] [Problems that the invention aims to solve]

[0009] Although film-type solar cells are firmly fixed by adhesive or other means to prevent them from scattering during use, their durability is currently said to be at most about 10 years, and the gap with the durability of exterior materials, which are becoming increasingly durable, is widening. Therefore, if the film-type solar cells deteriorate and cease to function during the service life of the exterior materials, they may either be left in that state or require replacement. When replacing film-type solar cells, the more firmly they are fixed to the exterior material, the more difficult it becomes to remove them without damaging the exterior material. In some cases, the removal process may damage the exterior material and reduce its durability.

[0010] In this regard, none of the Patent Documents 1 to 3 mention the replacement of solar cells.

[0011] This invention was made to solve the aforementioned problems and aims to provide a solar cell mounting exterior material that allows for easy replacement of film-type solar cells after the end of its service life. [Means for solving the problem]

[0012] (1) The solar cell mounting exterior material according to the present invention comprises an exterior material substrate made of a metal plate, the surface facing the outdoors in the installed state being made of a metal base material, plated, resin coated, or film laminated, and a film-type solar cell attached to the outdoor surface of the exterior material substrate so as to be integrated with the outdoor surface facing the outdoors in the installed state, The film-type solar cell is characterized in that it is bonded to the exterior substrate in a way that allows it to be easily peeled off.

[0013] (2) The invention described in (1) above is characterized in that at least one of the protective film surface on the back surface of the film-type solar cell or the outdoor surface of the exterior material substrate is made of a resin layer that is difficult to adhere to.

[0014] (3) Furthermore, in the case described in (1) above, the outdoor surface of the exterior material substrate is made of a difficult-to-adhere resin layer, and the difficult-to-adhere resin layer is formed by a coating film containing fluororesin or a laminate film.

[0015] (4) Furthermore, in the case described in (1) above, the protective film surface on the back surface of the film-type solar cell and the outdoor surface of the exterior material substrate are formed of a difficult-to-adhere resin layer, and the adhesion is improved by surface modification of either the protective film side or the outdoor surface side of the difficult-to-adhere resin layer.

[0016] (5) Furthermore, in the case described in (1) above, the outer circumference of the surface protective film of the film-type solar cell is enlarged compared to the back protective film, and at least the enlarged portion of the surface of the surface protective film facing the exterior material substrate is formed of a difficult-to-adhere resin layer, and the adhesion is enhanced by surface modification.

[0017] (6) In addition, in any of the above (1) to (5), the film-type solar cell and the surface of the exterior material substrate are integrated via an adhesive layer, and the adhesive layer is provided in the outer peripheral area that is at least outside the power generation layer of the protective film of the film-type solar cell.

[0018] (7) In addition, in any of the above (1) to (5), the film-type solar cell and the surface of the exterior material substrate are integrated via an adhesive layer, and the adhesive layer is provided in a triangular shape in the outer peripheral area that is outside the power generation layer of the protective film of the film-type solar cell, and at each corner of the power generation layer of the protective film.

[0019] (8) Further, in the one according to (6) or (7) above, an adhesive layer is provided within the range of the outer peripheral portion of the film-type solar cell, and a defective portion without an adhesive layer is provided at the tip of at least one corner portion of the outer peripheral portion.

[0020] (9) Further, in the one according to any one of (6) to (8) above, the adhesive strength of the adhesive layer with the protective film of the film-type solar cell is higher than the adhesive strength with the exterior material substrate, and when peeling the film-type solar cell from the exterior material substrate, most of the adhesive layer remains on the film-type solar cell side.

[0021] (10) Further, in the one according to any one of (1) to (8) above, the surface of the film-type solar cell and the exterior material substrate are integrated via an adhesive layer, and in order to make there be no remaining adhesive layer on the surface of the exterior material substrate, the adhesive strength of the adhesive layer with the protective film of the film-type solar cell is higher than the adhesive strength with the exterior material substrate, and the adhesive force of the adhesive layer on the exterior material substrate side is less than 20 kN / m 2 and it is characterized in that. [Effect of the Invention]

[0022] In the present invention, since the film-type solar cell is adhesively bonded to the exterior material substrate so as to be easily peeled off, when the film-type solar cell deteriorates, the film-type solar cell can be easily replaced. Thereby, the exterior material can be used until the durability year, which is economical. [Brief Description of the Drawings]

[0023] [Figure 1] It is an external view showing an installation state in which the solar cell-mounted exterior material according to the embodiment is used as a roofing material. [Figure 2] It is a top view of the film-type solar cell. [Figure 3] It is a plan view showing the arrangement of the adhesive layer on the back surface of the film-type solar cell (Part 1). [Figure 4]This is a plan view (part 2) showing the arrangement of the adhesive layer on the back of a film-type solar cell. [Figure 5] This is a plan view (part 3) showing the arrangement of the adhesive layer on the back of a film-type solar cell. [Modes for carrying out the invention]

[0024] As shown in Figure 1, the solar cell mounted exterior material 1 according to this embodiment comprises an exterior material substrate 3 made of a metal plate and a film-type solar cell 5 attached to the outdoor surface of the exterior material substrate 3 so as to be integrated with it. The film-type solar cell 5 is bonded to the exterior substrate 3 in a way that allows for easy peeling. The applications of the solar cell-mounted exterior material 1 include exterior materials for building structures such as roofing and exterior wall materials, as well as exterior materials for structures other than buildings, such as soundproof walls and sound barriers. However, Figure 1 shows the case where it is used as a roofing material. The following describes each component in detail.

[0025] <Exterior material substrate> The exterior substrate 3 is, for example, made of a rectangular metal molded plate, and the surface facing the outdoors when the exterior substrate 3 is installed is made of one of the following: raw metal, plated, resin coated, or film laminated. The durability of the exterior substrate 3 is expected to be 20 years or more.

[0026] To allow the film-type solar cell 5 to be easily peeled off and bonded, the outdoor surface of the exterior substrate 3, i.e., the surface to which the film-type solar cell 5 is attached, may be made of a difficult-to-bond resin layer. This difficult-to-bond resin layer may be formed, for example, by a coating containing fluororesin or a laminate film. By forming a difficult-to-adhere resin layer using a coating film or laminate film containing fluororesin, it is possible to achieve both improved durability and resistance to adhesion.

[0027] <Film-type solar cells> The film-type solar cell 5 is integrated with the outdoor surface of the exterior substrate 3, which is the outdoor side when installed, and is attached in a way that allows for easy removal. The film-type solar cell 5 is an organic thin-film solar cell (OPV), a thin-film crystalline silicon solar cell, or a perovskite solar cell, and as shown in Figure 2, the front and back of the power generation layer 7 are covered with a protective film 9.

[0028] In order to easily peel off and adhere the film-type solar cell 5 from the exterior substrate 3, the surface of the protective film 9 on the back of the film-type solar cell 5 may be made of a resin layer that is difficult to adhere to. For example, a fluororesin or polyimide resin can be used as the difficult-to-adhere resin layer. These can be used as a single layer, or as a multi-layer structure in which a fluororesin or polyimide resin is used on the exterior substrate 3 side and a resin such as PET resin is used on the inner surface side. In short, the difficult-to-adhere resin layer such as fluororesin or polyimide resin should be placed closest to the exterior substrate 3, and the resin layer on the inner surface is not particularly limited. The film-type solar cell 5 is expected to have a lifespan of approximately 10 years.

[0029] <An embodiment that allows for easy peeling and adhesion> Possible bonding methods include forming an adhesive layer using double-sided tape, heat fusion, or the use of adhesives such as hot melt adhesives. Furthermore, as an embodiment for easily peelable adhesion, as described above, the surface of the exterior material substrate 3 or the protective film 9 of the film-type solar cell 5 may be made of a resin layer that is difficult to adhere to. The difficult-to-adhere resin layer may be made from either the back surface of the film-type solar cell 5 or the outdoor surface of the exterior material substrate 3, or both. If one side has a difficult-to-adhere resin layer and the other side has not undergone such processing, the side with the difficult-to-adhere resin layer will be easier to peel off. In this case, it is preferable to make the exterior substrate 3 easily peelable. This ensures that no adhesive layer or other residue remains on the exterior substrate 3 when the film-type solar cell 5 is replaced, thus reducing the effort required to service the exterior substrate 3.

[0030] Furthermore, if both the exterior substrate 3 and the protective film 9 are made of a resin layer that is difficult to adhere to, the adhesion can be improved by surface-modifying either the exterior substrate 3 or the protective film 9. Here again, it is preferable to surface-modify the protective film 9 side of the film-type solar cell 5 in order to facilitate peeling from the exterior material side. Alternatively, instead of modifying the surface of the protective film 9, the surface of the protective film 9 on the exterior material substrate 3 side may be made a fluororesin layer to facilitate peeling, and the surface of the protective film 9 on the power generation layer 7 side may be made a PET resin layer to improve adhesion.

[0031] Furthermore, the protective films 9 on the front and back of the film-type solar cell 5 may be the same size, or the outer circumference of the protective film 9 on the front side may be larger than that of the protective film 9 on the back side. In this case, the surface of the protective film 9 on the front side facing the exterior material substrate 3 may be modified to improve adhesion, at least in that area. This method makes it possible to avoid thermal effects on the power generation layer 7 when it is desired to increase the adhesive strength of the double-sided tape or when heat fusion or hot melt adhesive is used on site.

[0032] Regarding adhesion, we will now explain in more detail the method of forming an adhesive layer using double-sided tape. In this case, to allow the film-type solar cell 5 to be easily peeled off the exterior substrate 3, a difference in adhesive strength may be provided between the front and back sides of the double-sided tape. Furthermore, it is best to apply the double-sided tape to the side with higher adhesive strength first, and more preferably, the adhesive strength should increase after some time has passed since application, making it easier to reapply to the exterior material. Also, the double-sided tape may consist only of an adhesive layer or may include a base material, but the base material must be stronger than the adhesive layer.

[0033] When the film-type solar cell 5 and the exterior substrate 3 are integrated via an adhesive layer, as shown in Figure 3, the adhesive layer 11 is provided in the outer peripheral area of ​​the protective film 9, which is at least outside the power generation layer 7. From the standpoint of preventing rainwater from entering the back surface of the film-type solar cell 5 and reducing the adhesive strength due to condensation, the entire back surface may be covered, but it is preferable to form an adhesive layer 11 without any breaks around the outer edge to prevent rainwater from entering the back surface of the film-type solar cell 5.

[0034] When estimating the area of ​​the adhesive layer 11 to be attached, the required area should be determined by considering the external forces (acting wind pressure) in the construction area, the decrease in adhesive strength due to temperature (heat) and ultraviolet rays during use, and the deterioration of adhesive strength over time due to the reduction in adhesive area caused by the intrusion of rainwater, etc. For example, a computational fluid dynamics analysis of a large warehouse constructed in an area with a standard wind speed of 34 m / s as defined by the Building Standards Act showed that the maximum vertical upward wind pressure was 3.2 kN / m 2 That was the case. Based on a 180° peel test of double-sided tape compliant with JIS Z0237, the adhesive strength was 20 kN / m². 2 Assuming a 3% decrease in adhesive strength per year due to aging and reduction in adhesive area, the remaining adhesive strength after 10 years of use will be approximately 60%. Therefore, for an OPV with outer dimensions of 300mm x 1000mm, the required adhesive area is 0.08m². 2 Therefore, you should apply tape with a width of 33mm or more to the outer perimeter.

[0035] The film-type solar cell 5 is exposed to wind and rain, and in particular, the corners are prone to a decrease in adhesive strength due to water attempting to penetrate from two directions, which poses a risk of delamination during use. Therefore, as shown in Figure 4, if the adhesive layer 11 is provided not only in the outer peripheral area of ​​the protective film 9 that is outside the power generation layer 7, but also at each corner of the power generation layer 7 of the protective film 9 in a triangular shape (see dashed lines in Figure 4), it is effective in suppressing peeling and scattering during use. On the other hand, when replacing the film-type solar cell 5, it is preferable to provide a starting point for peeling. For example, as shown in Figure 5, it is preferable to provide a missing portion 13 without the adhesive layer 11 at the tip of at least one edge corner of the outer periphery, thereby forming a tab.

[0036] Furthermore, the adhesive layer 11 has a higher adhesive strength with the protective film 9 than with the exterior substrate 3, and it is desirable that when peeling the film-type solar cell 5 from the exterior substrate 3, the majority of the adhesive layer 11 remains on the film-type solar cell 5 side. To reduce the amount of adhesive layer 11 remaining on the exterior substrate 3, and to reduce maintenance work such as peeling off the adhesive layer from the exterior substrate 3, it is preferable to design the exterior substrate 3 so that no adhesive residue remains on the exterior substrate 3 side. For this purpose, the adhesive strength of the adhesive layer 11 on the exterior substrate 3 side should be 20 kN / m 2 It's best to use "less than".

[0037] As described above, with the solar cell mounted exterior material 1 of this embodiment, the film-type solar cell 5 will not be blown away by wind and rain during its service life. Furthermore, after the film-type solar cell 5 has been put into service, when peeling the film-type solar cell 5 from the exterior material, the adhesive layer 11 and other components remain on the film-type solar cell 5 side, or in other words, they do not remain on the exterior material side when peeling. As a result, the exterior material is not damaged, durability is maintained, and the labor required to clean the surface of the exterior material is reduced, thus reducing the labor required for replacement work. [Explanation of Symbols]

[0038] 1. Exterior material with solar panels 3. Exterior material substrate 5. Film-type solar cells 7 Power generation layer 9 Protective film 11 Adhesive layer 13. Defective area

Claims

1. An exterior material comprising an exterior material substrate made of a metal plate, the surface facing the outdoors when installed being made of a metal base material, plated, resin coated, or film laminate, and a film-type solar cell attached to the outdoor surface of the exterior material substrate so as to be integrated with the outdoor surface when installed, The film-type solar cell is integrated with the exterior material substrate via an adhesive layer so that it can be easily peeled off. In order to prevent any adhesive residue from remaining on the surface of the exterior substrate, the adhesive layer has a higher adhesive strength to the protective film of the film-type solar cell than to the exterior substrate, and the adhesive strength of the adhesive layer on the exterior substrate side is 20 kN / m ２ The adhesive layer is set to be less than the film-type solar cell, so that when the film-type solar cell is peeled off from the exterior material substrate, no adhesive layer remains on the exterior material substrate. The adhesive layer is formed seamlessly on the outer periphery of the protective film, and is provided in a triangular shape in the outer periphery area that is outside the power generation layer of the protective film of the film-type solar cell, and at each edge corner of the power generation layer of the protective film. The adhesive layer is formed by double-sided tape, heat fusion, or hot melt adhesive. A solar cell mounting exterior material characterized in that the surface of the exterior material substrate is covered with a resin layer that is difficult to adhere to.

2. The solar cell mounting exterior material according to claim 1, characterized in that at least one edge corner tip of the outer periphery of the film-type solar cell is provided with a defect without an adhesive layer.

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