Semi-translucent gas barrier film, light-transmissive solar cell module, and light-transmissive display device

Abstract

To provide a semi-translucent gas barrier film that exhibits superior daylighting and dimming functions and is able to impart high durability to a target to which it is attached, as well as a light-transmissive solar cell module and a light-transmissive display device employing the semi-translucent gas barrier film.SOLUTION: A semi-translucent gas barrier film has a gas barrier layer, a metal thin film layer, and a resin film, wherein the metal thin film layer is disposed at any of the following positions (i) to (iii): (i) at the surface side of the gas barrier layer opposite to the side facing the resin film, (ii) between the gas barrier layer and the resin film, or (iii) at the surface side of the resin film opposite to the side facing the gas barrier layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a semi-transparent gas barrier film, and a light-transmitting solar cell module and a light-transmitting display device 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 highly sensitive to water vapor. Therefore, as disclosed in Patent Documents 1 and 2, there is an increasing need for gas barrier films in 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, as the use of solar cells expands, optical functions such as light transmission and dimming are required.

[0005] In view of the above problems, an object of the present invention is to provide a semi-transparent gas barrier film, a light-transmitting solar cell module, and a light-transmitting display device that have excellent light-transmitting and light-controlling properties and can impart high durability to an object to which they are attached. [Means for solving the problem]

[0006] As a result of extensive research into solving the above-mentioned problems, the inventors have found that the above-mentioned problems can be solved by providing a metal thin film layer and a resin film in a predetermined arrangement in addition to a gas barrier layer, and have thus completed the present invention. That is, the present invention provides the following [1] to [8].

[0007] [1] A semi-light-transmitting gas barrier film having a gas barrier layer, a metal thin film layer, and a resin film, wherein the metal thin film layer is disposed in any one of the following positions (i) to (iii): (i) a surface side of the gas barrier layer opposite to the resin film-facing surface; (ii) between the gas barrier layer and the resin film, or (iii) The surface side of the resin film opposite to the surface facing the gas barrier layer. [2] The semi-light-transmitting gas barrier film according to the above [1], which has a reflectance of 20 to 80% for light having a wavelength of 550 nm and a transmittance of 20 to 80% for light having a wavelength of 550 nm. [3] The semi-translucent gas barrier film according to [1] or [2] above, wherein the metal thin film layer has a thickness of 1,000 nm or less. [4] The semi-light-transmitting gas barrier film according to any one of the above [1] to [3], wherein the gas barrier layer contains a silicon-based film containing at least one of oxygen, nitrogen, and carbon. [5] A light-transmitting solar cell module having, in this order, a protective film, a light-transmitting solar cell element, and the semi-light-transmitting gas barrier film according to any one of [1] to [4] above. [6] The light-transmitting solar cell module according to the above [5], which has a light transmittance of 20 to 80% in the wavelength range of 400 to 800 nm. [7] A light-transmitting display device comprising a light-transmitting optical display element and the semi-light-transmitting gas barrier film according to any one of the above [1] to [4]. [8] The light transmission type display device according to the above [7], which has a light transmittance of 20 to 80% in the wavelength range of 400 to 800 nm. [Effects of the Invention]

[0008] According to the present invention, there are provided a semi-transparent gas barrier film that has excellent light-transmitting and light-controlling properties and can impart high durability to an object to which it is attached, as well as a light-transmitting solar cell module and a light-transmitting display device that use the same. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the configuration of a semi-transparent gas barrier film. [Figure 2] FIG. 2 is a cross-sectional view showing another example of the configuration of a semi-transparent gas barrier film. [Figure 3] FIG. 1 is a cross-sectional view showing an example of the configuration of a light-transmitting solar cell module. [Figure 4] FIG. 1 is a schematic diagram showing a state in which a light-transmitting solar cell module is installed on a transparent plate. [Figure 5] FIG. 1 is a cross-sectional view showing an example of the configuration of a light transmission type display device. [Figure 6] FIG. 1 is a cross-sectional view showing an example of the configuration of a light transmission type display device. [Figure 7] FIG. 10 is a cross-sectional view showing another example of the configuration of the light transmission type display device. [Figure 8] FIG. 10 is a cross-sectional view showing another example of the configuration of the light transmission type display device. 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, 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." 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." Hereinafter, a semi-transparent gas barrier film, a light-transmitting solar cell module, and a light-transmitting display device according to an embodiment of the present invention (hereinafter, sometimes referred to as "the present embodiment") will be described.

[0011] 1. Semi-transparent gas barrier film The semi-light-transmitting gas barrier film according to an embodiment of the present invention comprises a gas barrier layer, a metal thin film layer, and a resin film, and the metal thin film layer is disposed in any one of the following positions (i) to (iii). (i) a surface side of the gas barrier layer opposite to the resin film-facing surface; (ii) between the gas barrier layer and the resin film, or (iii) The surface side of the resin film opposite to the surface facing the gas barrier layer.

[0012] In the semi-transparent gas barrier film, the metal thin film layer functions as a half mirror, reflecting a predetermined amount of incident light while capturing external light to an extent that does not affect visibility. This provides excellent light-transmitting and light-controlling properties. Furthermore, the presence of the gas barrier layer and the reduction in moisture permeability of the metal thin film layer by a certain percentage also provide high durability to the object to which it is attached.

[0013] If the object to be attached is a light-transmitting solar cell element, the semi-transmitting gas barrier film imparts high durability to the light-transmitting solar cell element while maintaining light-transmitting and light-controlling properties. In particular, in the case of organic solar cell elements such as perovskite solar cell elements, organic thin-film solar cell elements, and dye-sensitized solar cell elements, an extremely low level of moisture contact is required, and the high gas barrier properties provided by the semi-transmitting gas barrier film prevent moisture-induced deterioration of the solar cell element. Furthermore, if the object to be attached is a light-transmitting solar cell element, the semi-transmitting gas barrier film reflects a predetermined amount of sunlight toward the solar cell element, thereby increasing power generation efficiency.

[0014] If the object to be affixed is a light-transmitting display element, the film provides high durability to the light-transmitting display element while maintaining light-transmitting and light-controlling properties. When the light-transmitting display element is not displaying, the metal thin film layer of the semi-transparent gas barrier film reflects part of the external light, so that, for example, the film has a mirror-like appearance when viewed from the outside, while allowing the outside to be seen from the inside.

[0015] The term "semi-transparent" refers to the property of transmitting a predetermined percentage of incident light. The semi-transparent gas barrier film preferably has a reflectance of 20 to 80% for light with a wavelength of 550 nm and a transmittance of 20 to 80% for light with a wavelength of 550 nm. When the reflectance and transmittance of the semi-transparent gas barrier film are within the above ranges, when the object to which the film is attached is a light-transmitting display element, it becomes easier to ensure image display properties and a mirror-like appearance in the non-display state. Furthermore, when the object to which the film is attached is a light-transmitting solar cell element, it becomes easier to ensure light transmission properties and a mirror-like appearance when viewed from the outside, and it becomes easier to improve the power generation efficiency of the light-transmitting solar cell element by reflecting external light. The reflectance and transmittance are measured using an ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-3600").

[0016] As will be described later, the metal thin film layer and the gas barrier layer can be made extremely thin, on the order of several hundred nanometers. Therefore, the semi-transparent gas barrier film according to this embodiment is thin and lightweight, yet possesses excellent optical properties (light transmittance and dimming properties) and gas barrier properties. Therefore, even when attached to a large-area object (e.g., a solar cell element attached to a windowpane) or an object requiring portability (e.g., a display element mounted on a portable electronic device), operability and portability are not impaired, and the film can be used for a variety of applications.

[0017] 1-1. Example of semi-transparent gas barrier film configuration FIG. 1 shows a specific example of the configuration of a semi-transparent gas barrier film according to an embodiment of the present invention. 1(a) to 1(f) are cross-sectional views showing first to sixth examples of semi-light-transmitting gas barrier films. 1(a), a first semi-transparent gas barrier film 100 is formed by laminating a resin film 30, a metal thin film layer 20, and a gas barrier layer 10 in this order from the side to be attached to an object. That is, the surface of the resin film 30 (the surface opposite to the surface facing the metal thin film layer 20) becomes the surface (external light incident surface) S1 of the semi-transparent gas barrier film, and the back surface of the gas barrier layer 10 (the surface opposite to the surface facing the metal thin film layer 20) becomes the back surface S2 of the semi-transparent gas barrier film. In this case, the surface S1 of the semi-transparent gas barrier film is the surface to be attached to an object. The structure of the first semi-light-transmitting gas barrier film 100 can be briefly shown as follows. First semi-transparent gas barrier film 100: Surface S1 / resin film 30 / metal thin film layer 20 / gas barrier layer 10 / back surface S2

[0018] The second to sixth semi-light-transmitting gas barrier films 101 to 105 shown in FIGS. 1(b) to 1(f) have the following configurations, when expressed in imitation of the first semi-light-transmitting gas barrier film 100. Second semi-transparent gas barrier film 101: Surface S1 / resin film 30 / gas barrier layer 10 / metal thin film layer 20 / back surface S2 Third semi-transparent gas barrier film 102: Surface S1 / metal thin film layer 20 / resin film 30 / gas barrier layer 10 / back surface S2 Fourth semi-transparent gas barrier film 103: Surface S1 / gas barrier layer 10 / resin film 30 / metal thin film layer 20 / back surface S2 Fifth semi-transparent gas barrier film 104: Surface S1 / Metal thin film layer 20 / Gas barrier layer 10 / Resin film 30 / Back surface S2 Sixth semi-transparent gas barrier film 105: Surface S1 / gas barrier layer 10 / metal thin film layer 20 / resin film 30 / back surface S2

[0019] The positions of the metal thin film layer 20 of the second semi-light-transmitting gas barrier film 101 and the fifth semi-light-transmitting gas barrier film 104 correspond to the above (i). The positions of the metal thin film layers 20 of the first semi-light-transmitting gas barrier film 100 and the sixth semi-light-transmitting gas barrier film 105 correspond to the above (ii). The positions of the metal thin film layers 20 of the third semi-light-transmitting gas barrier film 102 and the fourth semi-light-transmitting gas barrier film 103 correspond to the above (iii).

[0020] When the surface S1 is the surface to be attached to an object to be attached, of the first to sixth semi-light-transmitting gas barrier films 100 to 105, the first semi-light-transmitting gas barrier film 100, the third semi-light-transmitting gas barrier film 102, and the fifth semi-light-transmitting gas barrier film 104, in which the metal thin film layer 20 is located closer to the object to be attached (on the attachment surface side) than the gas barrier layer, are preferred from the viewpoint of suppressing deterioration of the metal thin film layer 20. Furthermore, the fifth semi-light-transmitting gas barrier film 104 is particularly preferred in that it is easy to protect the gas barrier layer and the metal thin film layer, both of which are thin films, from external stress.

[0021] The semi-light-transmitting gas barrier film may include layers other than the gas barrier layer 10, the metal thin film layer 20, and the resin film 30. For example, an intervening layer, a hard coat layer, a heat-shielding layer, an ultraviolet-shielding layer, etc. may be provided on the upper or lower surface of each of the above layers, or between each of the above layers.

[0022] FIG. 2 is a cross-sectional view showing another example of the configuration of a semi-light-transmitting gas barrier film. The seventh to tenth semi-transparent gas barrier films 106 to 109 shown in Figures 2(a) to 2(d) have a configuration in which a hard coat layer 90 is added to the lower surface of the first to fourth semi-transparent gas barrier films 100 to 103 shown in Figures 1(a) to 1(d), respectively. In the seventh semi-transparent gas barrier film 106 and the ninth semi-transparent gas barrier film 108, the hard coat layer 90 provided on the back surface of the gas barrier layer 10 prevents the gas barrier layer 10 from being damaged by contact with external objects. Furthermore, in the eighth semi-transparent gas barrier film 107 and the tenth semi-transparent gas barrier film 109, the hard coat layer 90 provided on the back surface of the metal thin film layer 20 prevents the metal thin film layer 20 from being damaged by contact with external objects.

[0023] The thickness of the semi-transparent gas barrier film can be appropriately determined depending on the intended use, etc. From the viewpoint of handleability, the thickness of the semi-transparent gas barrier film is preferably 1 to 1,000 μm, more preferably 5 to 200 μm, and even more preferably 15 to 100 μm.

[0024] The water vapor transmission rate of the semi-transparent 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 semi-transparent gas barrier film can be set to the above-mentioned numerical range by obtaining a semi-transparent gas barrier film that satisfies the above-mentioned requirements (1) and (2) according to the manufacturing method of the semi-transparent gas barrier film described below. The water vapor transmission rate is measured by a known method.

[0025] 1-2.Gas barrier layer In the above-mentioned semi-transparent gas barrier film, from the viewpoint of easily ensuring good gas barrier properties, the gas barrier layer preferably contains a silicon-based film containing at least one of oxygen, nitrogen, and carbon. Furthermore, from the viewpoint of ensuring high gas barrier properties at low cost, the gas barrier layer preferably is a gas barrier layer containing silicon and oxygen. Here, the content of silicon and oxygen in the gas barrier layer is preferably 50 at% or more, more preferably 60 at% or more, and even more preferably 70 at% or more, of the atoms constituting the gas barrier layer. There is no particular upper limit, but it is, for example, 99 at%. Here, "at%" represents the atomic ratio. The gas barrier layer is preferably 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.

[0026] 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.

[0027] The gas barrier layer preferably has a first region containing silicon, oxygen, carbon, and nitrogen in its thickness direction, 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.

[0028] 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

[0029] 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.

[0030] 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.

[0031] A plurality of high nitrogen content regions may be present in the depth direction. When a plurality of high nitrogen content regions are present, the total thickness of the regions may be 10 nm or more. From the viewpoint of preventing water vapor permeation from the edge, it is preferable that one of the plurality of high nitrogen content regions is located on the outermost surface of the semi-transparent 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.

[0032] In the depth direction of the gas barrier layer, the element ratio of nitrogen atoms can be made to gradually and continuously change from the outermost surface by forming a high nitrogen content region through a modification treatment, as will be described later. 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.

[0033] In the semi-translucent 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 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.

[0034] 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, it is possible to obtain a semi-transparent gas barrier film having sufficient gas barrier properties.

[0035] Each of the above thicknesses d G , d M can be set within the above numerical range by adjusting the composition of the coating liquid and the conditions of the modification treatment when producing a semi-transparent gas barrier film according to the method for producing a semi-transparent gas barrier film described below.

[0036] 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.

[0037]

[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.

[0038] Examples of the carbon-containing silicon-based polymer compound include polycarbosilane-based compounds, polysilane-based compounds, and mixtures thereof.

[0039] 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.

[0040] 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 semi-transparent gas barrier film having sufficient gas barrier properties can be obtained by subsequently subjecting the gas barrier precursor layer to a modification treatment.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] The ion species to be implanted by plasma ion implantation include the same ions as those exemplified above as the ions to be implanted.

[0045] 1-3. Other examples of semi-transparent gas barrier films The semi-light-transmitting 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 contain one or more other layers between the resin film and the gas barrier layer, between the resin film and the metal thin film layer, or between the metal film and the gas barrier layer, or on the resin film, on the gas barrier layer, or on the resin film, etc., within the scope of the object of the present invention.

[0046] The semi-transparent gas barrier film may be a long film, in which case the semi-transparent gas barrier film may be in the form of a roll wound around a core material.

[0047] 1-4.Metal thin film layer The metal thin film layer of the semi-light-transmitting gas barrier film according to this embodiment may be a vapor-deposited film of metal such as silver, aluminum, tin, or stainless steel. In the semi-transparent gas barrier film, from the viewpoint of light transmittance, the thickness of the metal thin film layer is preferably 1,000 nm or less, more preferably 500 nm or less, even more preferably 200 nm or less, even more preferably 100 nm or less, and particularly preferably 80 nm or less. There is no particular lower limit, but from the viewpoint of easily ensuring semi-transparent properties, it is, for example, 20 nm.

[0048] The metal thin film layer is formed on the resin film or the gas barrier layer by, for example, vacuum deposition, ion plating, sputtering, chemical vapor deposition (CVD), or atomic layer deposition (ALD).

[0049] 1-5.Resin film The resin film included in the semi-translucent gas barrier film according to this embodiment serves as a support for the thin gas barrier layer and the metal thin film layer. Examples of the resin film include polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT) film, polylactic acid (PLA) film, polycarbonate film, cycloolefin-based film, and cellulose-based film. These resin films are inexpensive and readily available with good optical transparency. The resin film may have various layers on its surface, such as a layer (anchor layer) for increasing adhesion to a layer formed on the resin film, an oligomer precipitation prevention layer, a lubricating layer, an antistatic layer, or a hard coat layer. The resin film may also be treated to increase adhesion by corona treatment, flame treatment, or the like. The resin film may not have been subjected to a heat-resistant treatment such as annealing, or may have been subjected to a heat-resistant treatment.

[0050] 1-6. Manufacturing method of semi-transparent gas barrier film The semi-light-transmitting gas barrier film according to this embodiment is produced, for example, by any one of the following procedures (a) to (c). (a) A gas barrier layer is formed on one surface of a resin film, and a metal thin film layer is formed on the other surface of the resin film. (b) A gas barrier layer is formed on one surface of a resin film, and a metal thin film layer is formed on the formed gas barrier layer. (c) A metal thin film layer is formed on one surface of a resin film, and a gas barrier layer is formed on the formed metal thin film layer.

[0051] In the above steps (a) to (c), the gas barrier layer is formed according to the procedure described in the above section "1-2. Gas barrier layer," and the metal thin film layer is formed according to the procedure described in the above section "1-4. Metal thin film layer." Furthermore, if necessary, other layers may be formed before, during, or after steps (a) to (c). For example, an anchor layer may be formed on the resin film before forming a gas barrier layer or a metal thin film layer on the resin film, or a hard coat layer may be formed on the formed gas barrier layer or metal thin film layer.

[0052] 2. Light-transmitting solar cell module The light-transmitting solar cell module according to this embodiment includes, in order, a protective film, a light-transmitting solar cell element, and a semi-light-transmitting gas barrier film having any of the above-described configurations. By using a semi-transparent gas barrier film having any of the above-described structures and a light-transmitting solar cell element, the entire solar cell module can be made light-transmitting.

[0053] FIG. 3 shows a specific example of the configuration of a light-transmitting solar cell module according to an embodiment of the present invention. The light-transmitting solar cell module 200 shown in FIG. 3 has a configuration in which a protective film 50, a light-transmitting solar cell element 40, and any one of the above-mentioned semi-transmitting gas barrier films 100 to 109 are laminated in this order from the external light incident surface S1 side. An adhesive layer 71 is disposed between the light-transmitting solar cell element 40 and any one of the semi-transparent gas barrier films 100 to 109, adhesively fixing them together. The light-transmitting solar cell element 40 has a pair of transparent electrodes 41, 43 and an active layer 42 sandwiched between them. The active layer 42 has a hole transport layer, a power generation layer, and an electron transport layer. The protective film 50 has a resin film 52 and a gas barrier layer 51 laminated in this order from the external light incident surface S1 side.

[0054] The gas barrier layer 51 may be the same as that described in the section "1-2. Gas barrier layer." The resin film 52 may be the same as that described in the section "1-5. Resin film."

[0055] The type of adhesive constituting the adhesive layer 71 is not particularly limited, and examples thereof include acrylic adhesives, urethane adhesives, silicone adhesives, and rubber adhesives. The thickness of the adhesive layer 71 is not particularly limited and may be appropriately selected, and is usually 0.5 to 100 μm, preferably 1 to 60 μm, and more preferably 3 to 40 μm.

[0056] Examples of the light-transmitting solar cell element include a perovskite solar cell element, an organic thin-film solar cell element, and a dye-sensitized solar cell element.

[0057] The light-transmitting solar cell module preferably has a light transmittance of 20 to 80% at wavelengths of 400 to 800 nm. When the light transmittance of the light-transmitting solar cell module is in this range, part of the incident light is reflected by the light-transmitting solar cell module and the other part is transmitted. As a result, it is difficult to see the back side of the light-transmitting solar cell module from the light-incident side, but from the light-exiting side, the outside can be seen through the light-transmitting solar cell module, and a certain amount of light can be obtained. The light transmittance is measured using an ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-3600"). The same applies to the light transmittance of a light-transmitting display device described later.

[0058] FIG. 4 is a diagram showing an example of how to use the light-transmitting solar cell module, and is a schematic diagram showing the state in which the light-transmitting solar cell module 200 shown in FIG. 3 is installed on a transparent plate 300 such as window glass. As shown in Fig. 4, the upper surface of the light-transmitting solar cell module 200 is adhesively fixed to one surface of the transparent plate 300 by an adhesive layer 72. As a result, in Fig. 4, the upper surface of the transparent plate 300 becomes the external light incident surface S1, and external light L1 to L3 enter from the upper surface of the transparent plate 300 as shown in Fig. 4. A portion of the external light L1 passes through the transparent plate 300 and the light-transmitting solar cell module 200 and exits from the back surface (external light exit surface) S2 of the light-transmitting solar cell module 200. Meanwhile, another portion of the external light L2 passes through the transparent plate 300, enters the light-transmitting solar cell module 200, is reflected by a metal thin film layer of any of the semi-transmitting gas barrier films 100 to 109, and exits from the upper surface of the transparent plate 300. Still another portion of the external light L3 is reflected by a metal thin film layer of any of the semi-transmitting gas barrier films 100 to 109 and is then absorbed by the active layer 42 of the light-transmitting solar cell element 40. Therefore, the area of ​​the transparent plate 300 to which the light-transmitting solar cell module 200 is attached has a certain degree of light transmission, although the area is less lit than other areas. Furthermore, the outside of the transparent plate 300 can be seen through this area. Furthermore, the external light incident surface S1 side has a mirror-like appearance, making it easier to ensure privacy. Furthermore, by using any of the above semi-transparent gas barrier films 100 to 109, a predetermined amount of external light L3 is reflected toward the light-transmitting solar cell element 40 and absorbed by the active layer 42, thereby increasing the power generation efficiency of the light-transmitting solar cell element 40. The material and thickness of the adhesive layer 72 can be the same as those of the adhesive layer 71 described above.

[0059] 3.Light transmission type display device A light-transmitting display device according to an embodiment of the present invention includes a light-transmitting optical display element and a semi-light-transmitting gas barrier film having any of the above-described configurations. The above-mentioned light-transmitting display device uses a semi-light-transmitting gas barrier film having any of the above-mentioned configurations, and by using a light-transmitting optical display element, the entire display device becomes light-transmitting.

[0060] Examples of the light-transmitting display element include a light-transmitting organic electroluminescent display element and a light-transmitting electrochromic display element.

[0061] 5 to 8 show specific configuration examples of the light transmission type display element according to the embodiment of the present invention. 5 and 6 includes a self-luminous light-transmitting display element 60 having transparent electrodes 61 and 63 and a light-emitting layer 62 sandwiched therebetween. The display device 400 has a structure in which, from the external light incident surface S1 side, a protective film 50, the light-transmitting display element 60, an adhesive layer 71, and one of the semi-transparent gas barrier films 100 to 109 are laminated. The structures and materials of the protective film 50 and the adhesive layer 71 are the same as those described for the light-transmitting solar cell module.

[0062] 5, when the light-transmitting display element 60 is in a non-display state, external light L1 and L2 enter the light-transmitting display device 400 from the upper surface of the light-transmitting display device 400. Part of the external light L1 passes through the protective film 50, the light-transmitting display element 60, the adhesive layer 71, and any one of the semi-transparent gas barrier films 100 to 109, and is emitted from the lower surface of the light-transmitting display device 400. On the other hand, another portion of the external light L2 passes through the protective film 50, the light-transmitting display element 60, and the adhesive layer 71, and is then reflected by the metal thin film layer of any of the semi-transparent gas barrier films 100 to 109, and is emitted from the top surface of the light-transmitting display device 400. Therefore, when the light-transmitting display element 60 is in a non-display state, the light-transmitting display device 400 has a mirror-like appearance when viewed from the external light incident surface S1 side.

[0063] Furthermore, when the light-transmitting display element 60 is in a display state, as shown in FIG. 6, a portion of external light L1 incident from the upper surface S1 is emitted from the lower surface S2, just as in the non-display state. However, radiant light E1 selectively emitted from the light-emitting layer 62 passes through the protective film 50, and is observed as an image when viewed from the top side of FIG. 6.

[0064] The light-transmitting display device 401 shown in Figures 7 and 8 has the same configuration as the light-transmitting display device 400 shown in Figures 5 and 6, except that a reflective light-transmitting display element 80 having transparent electrodes 81 and 83 and a color-emitting layer 82 sandwiched between them is used as the light-transmitting display element.

[0065] 7, when the light-transmitting display element 80 is in a non-display state, external light L1 and L2 enter the light-transmitting display device 401 from the upper surface of the light-transmitting display device 401. Part of the external light L1 passes through the protective film 50, the light-transmitting display element 80, the adhesive layer 71, and any one of the semi-transparent gas barrier films 100 to 109, and is emitted from the lower surface of the light-transmitting display device 401. On the other hand, another portion of the external light L2 passes through the protective film 50, the light-transmitting display element 80, and the adhesive layer 71, and is then reflected by the metal thin film layer of any of the semi-transparent gas barrier films 100 to 109, and is emitted from the top surface of the light-transmitting display device 401. Therefore, when the light-transmitting display element 80 is in a non-display state, the light-transmitting display device 401 has a mirror-like appearance when viewed from the external light incident surface S1 side.

[0066] Furthermore, when the light-transmitting display element 80 is in a display state, as shown in FIG. 8, a portion of external light L1 incident from the upper surface S1 is emitted from the lower surface S2, just as in the non-display state. However, a portion of the incident light is selectively reflected by the color-producing layer 82 to become reflected light R1, and this reflected light R1 passes through the protective film 50, so that it is observed as an image when viewed from the top side of FIG. 8.

[0067] In the above-mentioned light-transmitting display device, the light transmittance at wavelengths of 400 to 800 nm is preferably 20 to 80%. When the light transmittance of the light-transmitting display element is in the above range, the light-transmitting display device can easily have a mirror-like appearance when in a non-display state, and can prevent the image from becoming difficult to view when in a display state. [Explanation of symbols]

[0068] 10: Gas barrier layer 20: Metal thin film layer 30: Resin film 40: Light-transmitting solar cell element 41, 43: Transparent electrode 42:Active layer 50: Protective film 51: Gas barrier layer 52: Resin film 60: Self-luminous light-transmitting display element 61, 63: Transparent electrode 62: Light-emitting layer 71, 72: adhesive layer 80: Reflective light-transmitting display element 81, 83: Transparent electrode 82: Coloring layer 90: Hard coat layer 100-109: Semi-transparent gas barrier film 200: Light-transmitting solar cell module 300: Transparent plate 400, 401: Light transmission type display device S1: External light incident surface S2: External light exit surface L1, L2, L3: External light E1, E2: Synchrotron radiation R1, R2: Reflected light

Claims

1. A semi-light-transmitting gas barrier film comprising a gas barrier layer, a metal thin film layer, and a resin film, wherein the metal thin film layer is disposed in any one of the following positions (i) to (iii): (i) the surface side of the gas barrier layer opposite to the surface facing the resin film; (ii) between the gas barrier layer and the resin film, or (iii) The surface side of the resin film opposite to the surface facing the gas barrier layer.

2. 2. The semi-light-transmitting gas barrier film according to claim 1, which has a reflectance of 20 to 80% for light having a wavelength of 550 nm and a transmittance of 20 to 80% for light having a wavelength of 550 nm.

3. 3. The semi-light-transmitting gas barrier film according to claim 1, wherein the metal thin film layer has a thickness of 1,000 nm or less.

4. 3. The semi-light-transmitting gas barrier film according to claim 1, wherein the gas barrier layer comprises a silicon-based film containing at least one of oxygen, nitrogen, and carbon.

5. A light-transmitting solar cell module comprising, in order, a protective film, a light-transmitting solar cell element, and the semi-light-transmitting gas barrier film according to claim 1 or 2.

6. 6. The light-transmitting solar cell module according to claim 5, wherein the light transmittance at wavelengths of 400 to 800 nm is 20 to 80%.

7. A light-transmitting display device comprising a light-transmitting optical display element and the semi-light-transmitting gas barrier film according to claim 1 or 2.

8. 8. The light transmission type display device according to claim 7, wherein the light transmittance in the wavelength range of 400 to 800 nm is 20 to 80%.

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