Gas barrier film, solar cell device, and window member

Abstract

To provide a gas barrier film capable of effectively blocking water vapor, demonstrating heat-shielding properties in severe summer sunlight, and suppressing temperature drop in winter as much as possible, as well as a solar cell device and a window member employing the gas barrier film.SOLUTION: The present invention provides: a gas barrier film comprising a heat ray reflective layer, a heat ray absorbing layer, and a gas barrier film; and a solar cell device and a window member employing the gas barrier film.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas barrier film, and to a solar cell device and a window member using the same. [Background technology]

[0002] Until now, silicon-based solar cells have dominated the solar cell market, but recently, organic solar cells such as perovskite and dye-sensitized solar cells have been attracting attention due to their various properties, such as not requiring rare metals as raw materials, being able to generate electricity even with weak sunlight, and being flexible. Although such organic solar cells have the excellent properties described above, they have the drawback of being very sensitive to water vapor. Therefore, as shown in Patent Documents 1 and 2, the use of a gas barrier film has become essential in the production of organic solar cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-34875 [Patent Document 2] International Publication No. 2019 / 230534 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, solar cell elements have the characteristic that they cannot fully demonstrate their power generation performance if they become too hot or too cold. That is, in the harsh summer sunshine, the temperature of the solar cell itself becomes too high, and the power generation performance of the solar cell element decreases. On the other hand, in winter, the solar cell itself becomes too cold, and the power generation performance also decreases.

[0005] In view of the above problems, the present invention aims to provide a gas barrier film that sufficiently blocks water vapor, exhibits heat-shielding properties even under harsh summer sunlight, and minimizes temperature drops in winter, as well as a solar cell device and a window member that use the same. [Means for solving the problem]

[0006] As a result of extensive research into solving the above problems, the present inventors discovered that the above problems can be solved by including a heat ray reflective layer and a heat ray absorbing layer, and thus completed the present invention. That is, the present invention provides the following [1] to [5].

[0007] [1] A gas barrier film having a heat ray reflective layer, a heat ray absorbing layer, and a gas barrier layer. [2] The gas barrier film according to [1] above, wherein the heat ray reflective layer, the heat ray absorbing layer, and the gas barrier layer are laminated in this order. [3] The gas barrier film according to the above [1] or [2], further comprising an intervening layer between the heat ray reflective layer and the heat ray absorbing layer. [4] A solar cell device comprising the gas barrier film according to any one of the above [1] to [3] and an organic thin-film solar cell element. [5] A window member comprising the solar cell device according to [4] above and a transparent plate on which the solar cell device is laminated. [Effects of the Invention]

[0008] The present invention provides a gas barrier film that sufficiently blocks water vapor, exhibits heat-shielding properties even under harsh summer sunlight, and minimizes temperature drops in winter, as well as a solar cell device and a window member that use the same. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a gas barrier film. [Figure 2] FIG. 2 is a cross-sectional view showing another example of a gas barrier film. [Figure 3] FIG. 1 is a cross-sectional view showing an example of a solar cell device. [Figure 4] FIG. 3 is a cross-sectional view showing an example of the configuration of a window member. [Figure 5] FIG. 10 is a cross-sectional view showing another example of the configuration of the window member. DETAILED DESCRIPTION OF THE INVENTION

[0010] In this specification, preferred definitions can be selected arbitrarily, and combinations of preferred definitions can be considered more preferred. In this specification, the expression "XX to YY" means "XX or more and YY or less." In this specification, for preferred numerical ranges (e.g., ranges of content, etc.), the lower and upper limits described in stages can be independently combined. For example, the description "preferably 10 to 90, more preferably 30 to 60" can be combined with the "preferable lower limit (10)" and the "more preferable upper limit (60)" to form "10 to 60." In this specification, for example, "(meth)acrylic acid" refers to both "acrylic acid" and "methacrylic acid," and the same applies to other similar terms. In this specification, the property of inhibiting the permeation of water vapor or oxygen is referred to as "gas barrier property," and a film having gas barrier property is referred to as "gas barrier film." In this specification, the term "main component" means that the mass of the target component contained therein is 50 mass % or more relative to the total mass of a specified material or specified member. Although the present invention will be described using drawings in various places to facilitate understanding, the present invention is not limited to those shown in the drawings. Furthermore, each drawing is a schematic view, and for ease of understanding, the dimensions are exaggerated relative to the actual size. Furthermore, unless otherwise specified, the upper surface of each cross-sectional view will be referred to as the "front surface" or "top surface," and the lower surface of each cross-sectional view will be referred to as the "back surface" or "bottom surface." A gas barrier film according to an embodiment of the present invention (hereinafter sometimes referred to as "the present embodiment"), as well as a solar cell device and a window member using the same, will be described below.

[0011] 1. Gas barrier film The gas barrier film according to the embodiment of the present invention has a heat ray reflective layer, a heat ray absorbing layer, and a gas barrier layer. The gas barrier film, which includes a heat ray reflective layer and a heat ray absorbing layer in addition to the gas barrier layer, adequately blocks the intrusion of water vapor. Furthermore, heat rays (i.e., near-infrared rays with wavelengths in the range of 800 to 2,000 nm) incident from the heat ray reflective layer side are reflected by the heat ray reflective layer, preventing them from entering the gas barrier film. Therefore, by applying the gas barrier film to an object, externally incident heat rays are reflected by the heat ray reflective layer, preventing them from entering the object, thereby providing heat insulation even under harsh summer sunlight. Therefore, when the object is a solar cell, excessive temperature rise of the solar cell device due to heat rays, particularly heat rays contained in harsh summer sunlight, is prevented. As a result, a decrease in the power generation efficiency of the solar cell device due to heat rays is suppressed. Furthermore, the radiant heat incident from the surface on the heat ray absorbing layer side is absorbed by the heat ray absorbing layer. Therefore, by attaching the gas barrier film to an object, a decrease in the temperature of the object can be prevented even in winter, when the atmosphere on the heat ray reflecting layer side is low. Therefore, if the object is a solar cell device, its output can be easily maintained even in winter, and power generation efficiency can be stabilized.

[0012] 1-1. Gas barrier film configuration example An example of a specific configuration of the gas barrier film according to an embodiment of the present invention is shown in FIGS. FIG. 1 is a cross-sectional view showing first to third examples of the gas barrier film. 1(a) is a first gas barrier film 100 in which a heat ray reflective layer 30, a heat ray absorbing layer 20, and a gas barrier layer 10 are laminated in this order. Heat rays incident from the heat ray reflective layer 30 side are reflected by the heat ray reflective layer 30, and radiant heat incident from the heat ray absorbing layer 20 side is absorbed by the heat ray absorbing layer 20.

[0013] The order in which the heat ray reflective layer 30, the heat ray absorbing layer 20, and the gas barrier layer 10 are stacked is not particularly limited, and any order may be used. The second gas barrier film 101 shown in FIG. 1(b) has a heat ray reflective layer 30, a gas barrier layer 10, and a heat ray absorbing layer 20 laminated in this order. The third gas barrier film 102 shown in FIG. 1(c) has a gas barrier layer 10, a heat ray reflective layer 30, and a heat ray absorbing layer 20 laminated in this order. In both the gas barrier films 101 and 102, heat rays incident from the heat ray reflective layer 30 side are reflected by the heat ray reflective layer 30, and radiant heat incident from the heat ray absorbing layer 20 side is absorbed by the heat ray absorbing layer 20.

[0014] When the gas barrier layer 10 of the gas barrier film 100 is attached to an object to be attached, the surface is protected by the heat ray reflecting layer 30 and the heat ray absorbing layer 20, which prevents the gas barrier layer 10 from being damaged by contact with external objects, etc., and makes it easy to prevent a decrease in gas barrier properties. When the gas barrier layer 10 or heat ray absorbing layer 20 of the gas barrier films 100, 101 is attached to an object, the heat ray reflecting layer 30 becomes the outermost layer, making it easier to prevent heat rays from penetrating the gas barrier film and the object. When the heat ray absorbing layer 20 of the gas barrier films 101 and 102 is attached to an object, the heat ray absorbing layer 20 that has absorbed radiant heat comes into direct contact with the object, making it easy to prevent a drop in the temperature of the object.

[0015] The gas barrier film may include layers other than the heat ray reflective layer 30, the heat ray absorbing layer 20, and the gas barrier layer 10. For example, an intervening layer, a hard coat layer, a substrate layer, an ultraviolet blocking layer, etc. may be provided on the upper or lower surface of each of the above layers, or between each of the above layers. 2(a) further includes an intervening layer 40 between the heat ray reflective layer 30 and the heat ray absorbing layer 20. The other configuration of the gas barrier film 103 is the same as that of the gas barrier film 100. In the gas barrier film 103, the presence of the intervening layer 40 suppresses heat transfer from the heat ray absorbing layer 20 that has absorbed radiant heat to the heat ray reflecting layer 30. The intervening layer 40 is formed from, for example, a pressure-sensitive adhesive composition made of a transparent resin composition in which hollow particles are dispersed. 2(b), a fifth gas barrier film 104 further includes a hard coat layer 45 on the gas barrier layer 10. The other configuration of the gas barrier film 104 is the same as that of the gas barrier film 102 described above. In the gas barrier film 104, the hard coat layer 45 prevents the gas barrier layer 10 from being damaged due to contact with an external object.

[0016] The water vapor permeability of the above gas barrier film is 1×10 -3 (g / (m 2 The water vapor transmission rate is preferably 100 s or less. The water vapor transmission rate is measured in detail by the procedure described in the Examples below.

[0017] In the gas barrier film, the light transmittance at wavelengths of 400 to 800 nm when light is incident from the surface closer to the heat ray reflecting layer than the heat ray absorbing layer is preferably 60% or more from the viewpoint of ensuring good transparency. There is no particular upper limit, but from the viewpoint of ease of production, it is, for example, 99%. The light transmittance is measured in detail by the procedure described in the Examples below.

[0018] In the gas barrier film, the light reflectance at wavelengths of 800 to 2,000 nm when light is incident from the surface closer to the heat ray reflective layer than the heat ray absorbing layer is preferably 50% or more from the viewpoint of ensuring high heat ray reflectivity. There is no particular upper limit, but from the viewpoint of ease of production, it is, for example, 95%. The light reflectance is measured in detail by the procedure described in the Examples below.

[0019] In the gas barrier film, when light is incident from the surface closer to the heat ray absorbing layer than the heat ray reflective layer, the light transmittance and light reflectance at wavelengths of 800 to 2,000 nm are preferably both 20% or less. There is no particular lower limit, but from the viewpoint of ease of production, it is, for example, 1%. The light reflectance and light transmittance are measured in detail by the procedures described in the Examples below.

[0020] Next, each layer of the gas barrier film will be described.

[0021] 1-2.Gas barrier layer The gas barrier layer of the gas barrier film according to this embodiment is preferably a gas barrier layer containing silicon and oxygen as main components, from the viewpoint of ensuring high gas barrier properties at low cost. Here, "containing silicon and oxygen as main components" means that the total mass of silicon and oxygen is 50 mass% or more relative to the total mass of the gas barrier layer. The gas barrier layer may be formed from a coating of a composition containing a polysilazane compound and, optionally, a carbon-containing silicon-based polymer compound, as described below. The gas barrier layer preferably has, in the thickness direction thereof, a first region (high-nitrogen-containing region) that contains silicon, oxygen, and nitrogen, and, optionally, carbon, and has a higher nitrogen content than other regions.

[0022] As will be described later, the first region is formed by a modification process and has a relatively higher nitrogen content than the second region, which is a region other than the first region. Therefore, in the following description, the first region may also be referred to as a "modified region" or a "high-nitrogen-content region." The second region may also be referred to as a "non-modified region" or a "low-nitrogen-content region." The "high-nitrogen-content region" refers to a region that is stable over time and whose thickness does not decrease over time.

[0023] The gas barrier layer preferably has a first region in its thickness direction that contains silicon, oxygen, and nitrogen, and optionally further contains carbon, and satisfies the following requirements (1) and (2). Requirement (1): The composition of the first region is SiO x C y N z It is expressed as: x:0.20~0.50 y:0~0.30 z: 0.20~0.70 Requirement (2): The thickness d of the first region M is 10 nm or more.

[0024] The first region satisfying the above requirement (1) is thought to reflect a hard structure in which silicon and nitrogen are bonded, which is advantageous for achieving high gas barrier performance and high light transmittance. Furthermore, in the following requirement (1-1), the presence of a predetermined proportion of carbon is thought to impart appropriate flexibility to the gas barrier layer. Furthermore, as specified in the above requirement (2), it is believed that by making the thickness of the first region 10 nm or more, a region with high gas barrier properties is sufficiently ensured. In the above requirement (1), from the viewpoint of easily increasing light transmittance, it is more preferable that x, y, and z are in the following ranges (requirement (1-1)). x:0.25~0.45 y: 0.03~0.20 z: 0.20~0.65

[0025] The above thickness d M From the viewpoint of enhancing the gas barrier property, the thickness is preferably 12 nm or more, more preferably 30 nm or more, and from the viewpoint of increasing the strength of the gas barrier layer, it is even more preferably 50 nm or more, and even more preferably 60 nm or more. There is no particular upper limit, but from the viewpoint of ease of production, it is preferably 300 nm or less, more preferably 150 nm or less, and particularly preferably 90 nm or less.

[0026] The high nitrogen content region may be located on the outermost surface of the gas barrier layer or inside the gas barrier layer, but is preferably located on the outermost surface of the gas barrier layer from the viewpoints of exhibiting good gas barrier properties and ease of production.

[0027] In the gas barrier film, a plurality of high nitrogen content regions may be present in the depth direction. When a plurality of high nitrogen content regions are included, the total thickness of the high nitrogen content regions may be 10 nm or more. From the viewpoint of preventing water vapor permeation from the edges, it is preferable that one of the plurality of high nitrogen content regions is located on the outermost surface of the gas barrier film. A gas barrier layer having a plurality of high nitrogen content regions in the depth direction can be obtained, for example, by repeating the formation of a gas barrier precursor layer for forming the gas barrier layer and the modification treatment described below.

[0028] In the gas barrier film, the element ratio of nitrogen atoms in the depth direction of the gas barrier layer can be made to gradually and continuously change from the outermost surface by forming a high-nitrogen content region through a modification treatment, as described below. Typically, in the change in the element ratio of each element in silicon, oxygen, and nitrogen (and optionally, carbon) in the thickness direction of the gas barrier layer, there is a region where the element ratio of nitrogen is higher than in the deeper layer.

[0029] The thickness of the gas barrier film can be appropriately determined depending on the intended use, etc. From the viewpoint of handleability, the thickness of the gas barrier film is preferably 1 to 1,000 μm, more preferably 5 to 200 μm, and even more preferably 15 to 100 μm.

[0030] The water vapor transmission rate of the gas barrier film under an atmosphere of 40°C and a relative humidity of 90% is preferably 9.0 × 10 -3 g / m 2 / day or less, preferably 6.0 × 10 -3 g / m 2 / day or less, more preferably 9.0 × 10 -4 g / m 2 / day or less. The water vapor permeability of the gas barrier film can be set within the above numerical range by obtaining a gas barrier film that satisfies the above-mentioned requirements (1) and (2) according to the gas barrier film manufacturing method described below. The water vapor transmission rate is measured by a known method.

[0031] In the gas barrier film, from the viewpoint of easily ensuring high gas barrier properties and light transmittance, and good flexibility, and from the viewpoint of ease of production, the thickness d of the gas barrier layer is G and the thickness d of the first region M However, 1.00 ≥ d M / d G ≧0.01, and 0.80≧d M / d G It is more preferable that the relationship of 0.60 ≧ d M / d G It is more preferable that the relationship is ≧0.03.

[0032] Gas barrier layer thickness d G From the viewpoint of easily ensuring gas barrier properties, light transparency, and flexibility, as well as from the viewpoint of ease of production, the thickness is preferably 30 to 1,500 nm, and more preferably 100 to 400 nm. Gas barrier layer thickness d G Even if the nitrogen content is on the order of nanometers, by providing a high nitrogen content region, a gas barrier film having sufficient gas barrier properties can be obtained.

[0033] Each of the above thicknesses d G , d M can be set within the above numerical range by producing a gas barrier film according to the gas barrier film producing method described below and adjusting the composition of the coating solution and the conditions of the modification treatment during the production.

[0034] The gas barrier layer is formed from a gas barrier precursor layer, and is preferably formed from a layer obtained by drying a coating film of a coating liquid (hereinafter also referred to as "gas barrier precursor layer coating liquid") containing a polysilazane compound and, if desired, a carbon-containing silicon-based polymer compound. The high nitrogen content region can be formed by a modification treatment described below.

[0043] By providing a high nitrogen content region obtained by subjecting the gas barrier precursor layer, which is a layer obtained by drying a coating of the above-mentioned gas barrier precursor layer coating liquid, to a modification treatment described below, a gas barrier layer with excellent gas barrier properties can be efficiently formed. In particular, when the above-mentioned modification treatment is carried out by plasma irradiation in the presence of helium gas, it becomes easier to form a high nitrogen-containing region with a sufficient thickness.

[0035]

[0023] Examples of polysilazane compounds include inorganic polysilazanes and organic polysilazanes. Examples of inorganic polysilazanes include perhydropolysilazane, and examples of organic polysilazanes include compounds in which part or all of the hydrogen atoms in perhydropolysilazane have been substituted with organic groups such as alkyl groups. Among these, inorganic polysilazanes are more preferred from the viewpoints of availability and the ability to form a gas barrier layer with excellent gas barrier properties. Furthermore, as the polysilazane compound, commercially available products available as glass coating materials and the like can also be used as they are. The polysilazane compounds can be used singly or in combination of two or more.

[0036] Examples of the carbon-containing silicon-based polymer compound include polycarbosilane-based compounds, polysilane-based compounds, and mixtures thereof.

[0037] Examples of methods for forming a layer obtained by applying and drying a coating liquid for a gas barrier precursor layer include a method in which a coating liquid for a gas barrier precursor layer containing a polysilazane compound, and optionally a carbon-containing silicon-based polymer compound, other components, a solvent, and the like is applied onto a substrate film by a known method, and the resulting coating film is then appropriately dried to form the layer. Since the coating liquid for the gas barrier precursor layer contains the polysilazane compound described above, a conversion reaction of the polysilazane occurs when the coating liquid is heated after coating, resulting in a coating film (gas barrier precursor layer) with gas barrier properties.

[0038] The thickness of the gas barrier precursor layer is preferably 30 to 1,500 nm, and more preferably 100 to 400 nm. Even if the thickness of the gas barrier precursor layer is on the order of nanometers, a gas barrier film having sufficient gas barrier properties can be obtained by subsequently subjecting the layer to a modification treatment.

[0039] Examples of the modification treatment include ion implantation, vacuum ultraviolet light irradiation (irradiation with an excimer laser, etc.), etc. Among these, ion implantation is preferred because it can provide high gas barrier performance.

[0040] The ions to be implanted include ions of rare gases such as argon, helium, neon, krypton, and xenon, and ions of fluorocarbons, hydrogen, nitrogen, oxygen, carbon dioxide, chlorine, fluorine, and sulfur. These ions may be used alone or in combination of two or more.

[0041] The method of injecting ions is not particularly limited, but examples include a method of irradiating ions accelerated by an electric field (ion beam), a method of injecting ions in plasma, etc. Among these, the latter method of injecting plasma ions is preferred because it allows a gas barrier film to be easily obtained.

[0042] The ion species to be implanted by plasma ion implantation include the same ions as those exemplified above as the ions to be implanted.

[0043] 1-3.Other examples of gas barrier film configurations The gas barrier film according to the embodiment of the present invention is not limited to that shown in FIG. 1 or FIG. 2, and may include one or more other layers on the base film, between the base film and the gas barrier layer, or on the gas barrier layer, as long as the object of the present invention is not impaired. Examples of the other layers include other gas barrier layers, protective layers, etc. The positions of the other layers are not limited to those described above.

[0044] The gas barrier film may also be a long film. In this case, the gas barrier film may be in the form of a roll wound around a core material.

[0045] 1-4. Heat ray reflective layer The heat ray reflective layer of the gas barrier film of this embodiment is a layer that has the property of reflecting heat rays (that is, near-infrared light with a wavelength of 800 to 2,000 nm) and transmitting visible light (light with a wavelength of 380 to 800 nm). The heat ray reflective layer preferably has a configuration in which a metal-containing layer is laminated on at least one surface of a substrate such as a transparent resin film. Examples of the heat ray reflective layer include (i) a layer containing at least one metal layer of 0.1 nm or more and less than 30 nm, which is made of silver or an alloy thereof; (ii) a layer consisting of at least one metal layer and at least one high refractive index ceramic layer; and (iii) a Fabry-Perot interference filter consisting of a first oxide layer, a first metal layer, a second oxide layer, a second metal layer, and a third oxide layer.

[0046] In the case of (i) above, metallic silver is preferred as it has almost no absorption of visible light. The thickness of the metal layer is preferably within the range of 5 to 1,000 nm. The metal layer is preferably formed by vapor deposition, more preferably by vacuum deposition, sputtering or plasma CVD.

[0047] In the case of (ii) above, the high-refractive-index ceramic layer is preferably a layer consisting of at least one layer whose main component is an oxide, oxynitride, or nitride containing at least zinc, titanium, tin, indium, niobium, silicon, or aluminum, and has a sandwich structure in which high-refractive-index ceramic layers are provided on both sides of a metal layer. In this case, it is more preferable to have a laminate structure of 3 to 10 layers in which multiple metal layers and multiple high-refractive-index ceramic layers are alternately stacked.

[0048] The high-refractive-index ceramic layer preferably has a refractive index of 1.8 or more and less than 2.4. The thickness of the high-refractive-index ceramic layer is preferably set in combination with the metal layer to be laminated so as to satisfy the optical properties of the heat ray reflective layer. The thickness of each high refractive index ceramic layer is preferably in the range of 2 to 1,000 nm. The high refractive index ceramic layer is preferably formed by vapor deposition, more preferably by vacuum deposition, sputtering, ion plating, Cat-CVD, or plasma CVD. It may also be formed by atmospheric pressure plasma CVD.

[0049] In the case of (iii) above, the metal layer in the Fabry-Perot interference filter is primarily silver, with less than 50% gold or copper alloy or cladding layer to provide chemical and optical durability. The oxide layer is preferably indium oxide, but other oxides such as zinc oxide, tin oxide, titanium oxide, and niobium oxide may also be used in the case of transparent dielectric layers with a refractive index of 1.8 or greater and a visible light absorption level of less than 10%. Nitrides and fluorides can also be used as long as they are transparent and have a refractive index greater than 1.8. Details of Fabry-Perot filters are described in U.S. Pat. No. 4,799,745.

[0050] The heat ray reflective layer may have a low refractive index layer in addition to the high refractive index layer in order to obtain high durability. In this case, the refractive index of the low refractive index layer is preferably 1.3 or more and less than 1.8. By setting the refractive index of the low refractive index layer within this range, durability and handleability can be improved without substantially affecting the visible light transmittance and infrared reflectance, and the denseness of the film can be ensured, resulting in good durability.

[0051] The heat ray reflective layer may be a commercially available transparent heat ray reflective film, such as "Reftel (registered trademark)" manufactured by Teijin Frontier Co., Ltd.

[0052] 1-5.Heat absorbing layer The heat ray absorbing layer of the gas barrier film of this embodiment is a layer that has the property of transmitting visible light (light with a wavelength of 380 to 800 nm) and absorbing heat rays (near-infrared light with a wavelength of 800 to 2,000 nm). The heat ray absorbing layer mainly contains a heat ray absorbing material and a matrix resin. The content of the heat ray absorbing material in the heat ray absorbing layer is preferably 0.01 to less than 20 parts by mass, more preferably 0.1 to 10 parts by mass, relative to 100 parts by mass of the matrix resin. By setting the content of the heat ray absorbing material within the above range, the dispersion of the heat ray absorbing material in the matrix resin is improved, an increase in haze (cloudiness) of the heat ray absorbing layer can be suppressed, and sufficient heat ray absorption ability can be obtained. The thickness of the heat ray absorbing layer is not particularly limited, but is preferably in the range of 0.2 μm to 400 μm, and more preferably in the range of 1 μm to 10 μm. If the thickness of the heat ray absorbing layer is within the above range, it is not necessary to excessively increase the content of the heat ray absorbing material in order to exhibit practical heat ray absorption properties, and as a result, it is possible to prevent a decrease in the mechanical strength of the heat ray absorbing layer. Furthermore, if the thickness of the heat ray absorbing layer is within the above range, it is possible to improve processability and handleability.

[0053] The heat ray absorbing layer is formed by preparing a resin composition in which the above heat ray absorbing material is dispersed in a resin material that will serve as a matrix resin, applying the resin composition to another layer or a support to be laminated, drying it, and curing the resin material as necessary.

[0054] Examples of heat ray absorbing materials include heat ray absorbing particles such as ATO (antimony-containing tin oxide), ITO (tin-containing indium oxide), tungsten oxide, composite tungsten oxide, and hexaboride particles.

[0055] The matrix resin constituting the heat ray absorbing layer is not particularly limited as long as it is a resin having transparency, and may be a cured product of an energy ray curable resin composition, a cured product of a thermosetting resin composition, a thermoplastic resin, etc. From the viewpoint of heat resistance, a cured product of an energy ray curable resin composition and a cured product of a thermosetting resin composition are preferred, and a cured product of an energy ray curable resin composition is more preferred.

[0056] 2. Gas barrier film manufacturing method The method for producing a gas barrier film according to an embodiment of the present invention includes the following steps. Step 1: Prepare a heat reflective layer. Step 2: Forming a heat absorbing layer. Step 3: Forming a gas barrier layer.

[0057] 2-1. Process 1 (heat ray reflective layer preparation process) The heat ray reflective layer is prepared by the procedure described in the above section "1-4. Heat ray reflective layer," or, as described above, a commercially available transparent heat ray reflective film is prepared as the heat ray reflective layer.

[0058] 2-2. Step 2 (heat ray absorbing layer formation step) The heat ray absorbing layer is formed on the heat ray reflecting layer by the procedure described in the above section "1-5. Heat ray absorbing layer."

[0059] 2-3. Step 3 (Gas barrier layer formation step) In step 3, a gas barrier layer is formed on the heat ray absorbing layer according to the procedure described in the above section "1-2. Gas barrier layer."

[0060] In the case of the gas barrier film 101 shown in Figure 1(b), the steps 1, 3, and 2 are carried out in this order, and after forming the gas barrier layer on the heat ray reflective layer, the heat ray absorbing layer is formed. In the case of the gas barrier film 102 shown in Figure 1(c), the steps are carried out in the order of step 1, step 3, and step 2 above, to form a gas barrier layer on one side of the heat ray reflective layer, and then a heat ray absorbing layer is formed on the other side of the heat ray reflective layer; alternatively, the steps are carried out in the order of step 1, step 2, and step 3 above, to form a heat ray absorbing layer on one side of the heat ray reflective layer, and then a gas barrier layer is formed on the other side of the heat ray reflective layer.

[0061] 2.Solar cell device A solar cell device according to an embodiment of the present invention includes any of the gas barrier films described above and an organic thin-film solar cell element. FIG. 3 is a cross-sectional view showing an example of a solar cell device according to an embodiment of the present invention. 3 includes an organic thin-film solar cell element 70, and a gas barrier layer 10, a heat ray absorbing layer 20, and a heat ray reflecting layer 30 derived from the gas barrier film 100 described above. The organic thin-film solar cell element 70 is provided on a back sheet 50, and its upper and side surfaces are covered with a sealing layer 60, and the organic thin-film solar cell element 70 is sealed by the back sheet 50 and the sealing layer 60. The gas barrier layer 10 is in contact with the upper surface of the sealing layer 60, and the heat ray absorbing layer 20 and the heat ray reflecting layer 30 are laminated in this order on the upper surface of the gas barrier layer 10.

[0062] Since the organic thin-film solar cell element 70 itself is transparent, the entire solar cell device 200 can be made transparent by using transparent backsheet 50 and sealing layer 60. Furthermore, since heat rays incident from the heat ray reflective layer 30 side are reflected by the heat ray reflective layer 30, an excessive temperature rise inside the solar cell device 200 is prevented, and a decrease in the power generation efficiency of the organic thin-film solar cell element 70 is suppressed. On the other hand, since the radiant heat incident from the back sheet 50 side is absorbed by the heat ray absorbing layer 20, even if the temperature of the atmosphere (i.e., the outside air) on the front side of the heat ray reflecting layer 30 is low, if radiant heat is radiated from the back side of the back sheet 50, the heat ray absorbing layer 20 absorbs the radiant heat, suppressing a drop in temperature inside the solar cell device 200 and suppressing a decrease in the power generation efficiency of the organic thin-film solar cell element 70.

[0063] Examples of the sealing material used to form the sealing layer include rubber-based resins, acrylic-based resins, olefin-based resins, ester-based resins, epoxy-based resins, styrene-based resins, silicone-based resins, etc. From the viewpoint of improving sealing properties, it is preferable to use a curable resin that is cured by heat or light among the above resins.

[0064] The thickness of the sealing layer is not particularly limited as long as it can seal the object to which it is attached, but from the viewpoint of sealing properties and transparency, it is preferably 50 to 3,000 μm, more preferably 300 to 1,500 μm.

[0065] The back sheet is a light-transmitting sheet, and examples thereof include glass, acrylic resin, polycarbonate, polyester, and fluorine-containing resin. The thickness of the back sheet is preferably 25 to 1,000 μm, more preferably 50 to 500 μm, from the viewpoints of transparency and sealing property.

[0066] The solar cell device 200 is fabricated, for example, by the following procedure. First, the organic thin-film solar cell element 70 is placed on the back sheet 50, and then the sealing composition is applied so as to cover the top and side surfaces of the organic thin-film solar cell element 70 and to make the surface flat, and then dried. Thereafter, a gas barrier film 100 is laminated on the upper surface of the layer made of the sealing composition, and the sealing composition is heat-cured to form a sealing layer 60, and the gas barrier film 100 is adhered by the sealing layer 60, thereby obtaining a solar cell device 200. As another method, the layer made of the sealing composition after application is heat-cured to form the sealing layer 60, and then the gas barrier film 100 is attached via an adhesive layer to obtain the solar cell device 200.

[0067] When the gas barrier film 101 shown in FIG. 1(b) is used, or when the gas barrier film 102 shown in FIG. 1(c) is used, the solar cell device is produced in the same manner as described above, except that the gas barrier film 101 or 102 is arranged so that the lower surface of the heat ray absorbing layer 20 is in contact with the sealing layer.

[0068] 3. Window materials The window member according to this embodiment includes the solar cell device described above and a transparent plate on which the solar cell device is laminated. FIG. 4 is a cross-sectional view showing an example of the configuration of a window member according to an embodiment of the present invention. 4 includes a transparent plate 90 and a solar cell device 200 attached to the transparent plate 90 with an adhesive layer 80. The solar cell device 200 has the same configuration as that shown in FIG. 4, the back surface of the backsheet 50 of the solar cell device 200 is fixed to a transparent plate 90 by an adhesive layer 80. Here, the transparent plate 90 is a transparent plate such as a glass plate or an acrylic plate. The adhesive layer 80 has the property of transmitting visible light and heat rays.

[0069] The window member 300 is installed in a window frame so that the solar cell device 200 faces outdoors. Visible light VL from outdoors passes through the gas barrier film portion of the solar cell device 200 to reach the organic thin-film solar cell element 70, and is used for power generation by the organic thin-film solar cell element 70. Note that, because the organic thin-film solar cell element 70 is optically transparent, some visible light passes through the organic thin-film solar cell element 70 and the transparent plate 90 to reach the indoors. Therefore, it is possible to check the outdoor conditions through the window member 300 from indoors.

[0070] On the other hand, heat rays R1 from the outdoors are reflected by the heat ray reflecting layer 30 of the solar cell device 200. This makes it possible to prevent the temperature of the solar cell device 200 from rising excessively.

[0071] Furthermore, radiant heat R2 from indoors passes through the transparent plate 90, the adhesive layer 80, the back sheet 50, and the organic thin-film solar cell element 70 to reach the heat ray absorbing layer 20. The heat ray absorbing layer 20 absorbs the radiant heat R2, thereby preventing the temperature of the solar cell device 200 from decreasing, even when the outside air temperature is low, particularly in winter, and ensuring a predetermined power generation efficiency.

[0072] FIG. 5 is a cross-sectional view showing another example of the configuration of the window member according to the embodiment of the present invention. The window member 301 shown in Figure 5 has a transparent plate 90 and a solar cell device 200, similar to the window member 301 in Figure 4, but unlike the window member 301, the gas barrier film portion of the solar cell device 200 is attached to the transparent plate 90 via an adhesive layer 80.

[0073] The window member 301 is installed in a window frame so that the solar cell device 200 faces indoors. Visible light VL from outdoors passes through the transparent plate 90 and the gas barrier film portion of the solar cell device 200 to reach the organic thin-film solar cell element 70, some of which is used to generate electricity in the organic thin-film solar cell element 70, and the other part passes through the organic thin-film solar cell element 70 and the back sheet 50 to reach indoors.

[0074] Heat rays R1 from the outdoors pass through the transparent plate 90 but are reflected by the heat ray reflecting layer 30 of the solar cell device 200. This makes it possible to prevent the temperature of the solar cell device 200 from rising excessively.

[0075] Furthermore, radiant heat R2 from indoors passes through the back sheet 50 and the organic thin-film solar cell element 70, reaches the heat ray absorbing layer 20, and is absorbed by the heat ray absorbing layer 20. Therefore, in the window member 301, in addition to the solar cell device 200 being installed indoors, radiant heat from indoors is absorbed into the solar cell device 200, which also suppresses a drop in temperature of the solar cell device 200 even when the outside air temperature is low, making it easier to ensure a predetermined power generation efficiency.

[0076] The window member is produced by providing an adhesive layer on at least one of the transparent plate and the solar cell device, and then adhesively bonding the two together with the adhesive layer. The pressure-sensitive adhesive layer can be formed from a conventionally used pressure-sensitive or heat-sensitive adhesive. Examples of suitable pressure-sensitive adhesives include those primarily composed of resins such as natural rubber, acrylic resins, ethylene-vinyl acetate copolymers, polyurethane, polyester, silicone rubber, fluorine-containing rubber, and polyvinyl butyral. Among these pressure-sensitive adhesives, those primarily composed of acrylic resins are preferred in terms of heat resistance, transparency, durability, and weather resistance, and acrylic pressure-sensitive adhesives primarily composed of acrylic alkyl esters are particularly preferred. Acrylic pressure-sensitive adhesives primarily composed of such alkyl acrylate esters have low initial adhesive strength, excellent removability and repositionability, and are easy to reposition and handle. Furthermore, after application, the adhesive strength improves over time, eliminating the risk of lifting, peeling, or the like. The adhesive strength of the pressure-sensitive adhesive is preferably 1 N / 25 mm or more, and more preferably 10 N / 25 mm or more.

[0077] In addition to the adhesive, the adhesive layer may contain, as needed, a tackifier, a softener, an antioxidant, a stabilizer, an ultraviolet absorber, and the like. The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably about 5 to 100 μm, and more preferably about 20 to 50 μm. When the thickness of the pressure-sensitive adhesive layer is in the above range, the necessary adhesive strength can be ensured, and good flexibility and handleability can be achieved. [Example]

[0078] Next, specific examples of the present invention will be described, but the present invention is not limited to these examples in any way. The water vapor barrier properties, light transmittance, heat shielding properties, and heat absorption properties of the gas barrier films produced in the examples and comparative examples described below were measured, calculated, and evaluated according to the following procedures. In all cases, "G" was considered pass, and "NG" was considered fail.

[0079] [Water vapor barrier properties] The gas barrier films obtained in the examples and comparative examples were placed on a 50 cm 2 The sample was cut into a circular shape to prepare a measurement sample, and the water vapor transmission rate was measured using a water vapor transmission rate measuring device (AQUATRAN-2, manufactured by MOCON) under conditions of 40°C, 90% RH, and a gas flow rate of 20 sccm. Water vapor permeability is 1×10 -3 (g / (m 2 ·day)) The following cases are "G", 1 × 10 -3 (g / (m 2 Cases exceeding 10 days were evaluated as "NG".

[0080] [Light transmittance] The light transmittance (%) of the gas barrier films obtained in the examples and comparative examples was measured using an ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrophotometer (Shimadzu Corporation, product name "UV-3600"), and the light transmittance of each gas barrier film was evaluated according to the following criteria. (i) When light is incident from the opposite side of the gas barrier layer, a light transmittance of 60% or more in the wavelength range of 380 to 800 nm is always rated as "G", and a light transmittance of less than 60% is rated as "NG". (ii) When light is incident from the opposite side of the gas barrier layer, if the film always has a light reflectance of 50% or more in the wavelength range of 800 to 2,000 nm, it is rated as "G", and if the light reflectance is less than 50%, it is rated as "NG". (iii) When light is incident from the gas barrier layer side, if the light reflectance and light transmittance are both 20% or less in the wavelength range of 800 to 2,000 nm, the rating is "G." If at least one of the light reflectance and light transmittance exceeds 20%, the rating is "NG."

[0081] [Heat insulation] The evaluation cell prepared below was left outdoors and exposed to sunlight from the side opposite the gas barrier layer. The temperature of the evaluation cell was checked with an infrared monitor. If the temperature of the evaluation cell was below 40°C, it was rated as "G", and if it was 40°C or higher, it was rated as "NG". <Preparation of evaluation cell> An evaluation cell was produced by bonding the surface of the gas barrier layer of the gas barrier film obtained in the Examples and Comparative Examples described below to a quartz glass sheet with a thickness of 0.20 mm with an ultraviolet-curable resin (manufactured by Nagase ChemteX Corporation) interposed between the film and the quartz glass sheet, and curing the ultraviolet-curable resin by irradiating it with ultraviolet light.

[0082] [Endothermic] The temperature of the evaluation cell was checked with an infrared monitor when an infrared lamp was irradiated from the gas barrier layer side (quartz glass side) of the same evaluation cell as above. If the temperature of the evaluation cell was 30°C or higher, it was evaluated as "G", and if it was less than 30°C, it was evaluated as "NG".

[0083] [Example 1] A mixture of 100 parts by mass (solids equivalent, hereinafter) of urethane hard coating agent "UVTKA-520" (Tokushiki Corporation) and 5 parts by mass of heat absorbing material cesium-doped tungsten oxide (Sumitomo Metal Mining Co., Ltd., trade name "YMF-02A") was applied by spin coating to the heat reflective layer side of a heat reflective substrate "Reftel ZA05T" (Teijin Frontier Co., Ltd.). The mixture was dried at 100°C for 1 minute and then cured by ultraviolet irradiation to form a 1.5 μm thick heat absorbing layer. Note that the "solids" refers to the components other than the solvent in the coating solution. This also applies to the following comparative examples. Perhydropolysilazane (AZNL110A-20, manufactured by AZ Electronic Materials) was applied onto the heat ray absorbing layer by spin coating and heated at 120°C for 2 minutes to form a perhydropolysilazane layer (thickness 150 nm). Subsequently, a plasma ion implantation device was used to implant argon (Ar) plasma ions into the surface of the perhydropolysilazane-containing layer to perform a modification treatment, thereby producing the gas barrier film of Example 1. The plasma ion implantation device and plasma ion implantation conditions used in the modification treatment were as follows: <Plasma ion implantation equipment> RF power supply: Model number "RF" 56000, manufactured by JEOL Ltd. High-voltage pulse power supply: "PV-3-HSHV-0835", manufactured by Kurita Manufacturing Co., Ltd. <Plasma ion implantation conditions> Plasma generating gas: Argon (Ar) Gas flow rate: 100sccm ·Duty ratio: 0.5% Repetition rate: 1,000Hz Applied voltage: -10kV ·RF power supply: Frequency 13.56MHz, applied power 1,000W Chamber pressure: 0.2 Pa Pulse width: 5μsec Processing time (ion implantation time): 300 seconds

[0084] [Comparative Example 1] Perhydropolysilazane (AZNL110A-20, manufactured by AZ Electronic Materials) was applied by spin coating to the heat ray reflective layer side of "Reftel ZA05T" (manufactured by Teijin Frontier Co., Ltd.) as a heat ray reflective substrate, and heated at 120°C for 2 minutes to form a perhydropolysilazane layer (thickness 150 nm). Then, under the same conditions as in Example 1, a plasma ion implantation device was used to implant argon (Ar) plasma ions into the surface of the perhydropolysilazane-containing layer to perform a modification treatment, thereby producing a gas barrier film of Comparative Example 1.

[0085] Comparative Example 2 A mixture of 100 parts by mass of a urethane-based hard coating agent "UVTKA-520" (manufactured by Tokushiki Corporation) and 5 parts by mass of cesium-containing tungsten oxide (manufactured by Sumitomo Metal Mining Co., Ltd., product name "YMF-02A") as a heat ray absorbing material was applied onto a PET film using a spin coating method, dried at 100°C for 1 minute, and then cured by irradiating with ultraviolet light to form a heat ray absorbing layer 1.5 μm thick. Perhydropolysilazane (AZNL110A-20, manufactured by AZ Electronic Materials) was applied onto the heat ray absorbing layer by spin coating and heated at 120°C for 2 minutes to form a perhydropolysilazane layer (thickness 150 nm). Thereafter, under the same conditions as in Example 1, a plasma ion implantation device was used to implant argon (Ar) plasma ions into the surface of the perhydropolysilazane-containing layer to perform a modification treatment, thereby producing a gas barrier film of Comparative Example 2.

[0086] Comparative Example 3 Perhydropolysilazane (AZNL110A-20, manufactured by AZ Electronic Materials) was applied to a PET film by spin coating and heated at 120°C for 2 minutes to form a perhydropolysilazane layer (thickness 150 nm). Thereafter, under the same conditions as in Example 1, a plasma ion implantation device was used to implant argon (Ar) plasma ions into the surface of the perhydropolysilazane-containing layer to perform a modification treatment, thereby producing a gas barrier film of Comparative Example 3.

[0087] Table 1 shows the results of the measurements and evaluations of the gas barrier films of the examples and comparative examples.

[0088] [Table 1]

[0089] As is clear from the results in Table 1, the gas barrier film of Example 1, which had a heat ray reflective layer and a heat ray absorbing layer, was evaluated to be good in terms of light transmittance, water vapor barrier property, heat shielding property, and heat absorption property. Therefore, it can be seen that by attaching the gas barrier film of Example 1 to an organic thin-film solar cell element sealed with a sealing layer, it is possible to block the incidence of heat rays from outside and to suppress a temperature drop due to the absorption of radiant heat by the heat ray absorbing layer.

[0090] On the other hand, the gas barrier film of Comparative Example 1, which had a heat ray reflective layer but no heat ray absorbing layer, was evaluated as having good light transmittance for light from the side opposite the gas barrier film, water vapor barrier property, and heat shielding property, but was evaluated as having poorer light transmittance for light from the gas barrier layer side and heat absorption property than Example 1. Furthermore, the gas barrier film of Comparative Example 2, which had a heat ray absorbing layer but no heat ray reflecting layer, was evaluated as having good light transmittance from 380 to 800 nm for light from the opposite side to the gas barrier film, good light transmittance for light from the gas barrier layer side, water vapor barrier property, and heat absorption property, but was inferior to Example 1 in light transmittance from 800 to 2,000 nm for light from the opposite side to the gas barrier film and good heat shielding property. Furthermore, the gas barrier film of Comparative Example 3, which did not have a heat ray reflective layer or a heat ray absorbing layer, did not meet the standards for light transmittance, water vapor barrier property, heat shielding property, and heat absorption property, and was inferior to the Examples. [Explanation of symbols]

[0091] 10: Gas barrier layer 20: Heat ray absorbing layer 30: Heat ray reflective layer 40: Intervening layer 45: Hard coat layer 50: Back seat 60: Sealing layer 70: Organic thin-film solar cell element 80: Adhesive layer 90: Transparent plate 100: Gas barrier film 200: Solar cell device 300, 301: window member R1: Heat rays from outdoors R2: Radiant heat from indoors VL: Visible light

Claims

1. A gas barrier film having a heat ray reflective layer, a heat ray absorbing layer, and a gas barrier layer.

2. The gas barrier film according to claim 1 , wherein the heat ray reflective layer, the heat ray absorbing layer, and the gas barrier layer are laminated in this order.

3. The gas barrier film according to claim 1 or 2, further comprising an intervening layer between the heat ray reflective layer and the heat ray absorbing layer.

4. A solar cell device comprising the gas barrier film according to claim 1 or 2 and an organic thin-film solar cell element.

5. A window member comprising: the solar cell device according to claim 4; and a transparent plate on which the solar cell device is laminated.

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