Hard coat film

Abstract

The present invention provides a hard coat film that, when used in solar cells, can provide gas barrier and ultraviolet shielding performance without increasing the number of components, and has a sufficiently high total light transmittance. [Solution] A gas barrier layer is provided on one side of a transparent substrate, and a hard coat layer containing an ultraviolet-curable resin is laminated on the other side of the transparent substrate, the light transmittance at a wavelength of 365 nm is less than 10%, the light transmittance at a wavelength of 440 nm is 80% or more, and the total light transmittance is 80% or more.

Description

Technical Field

[0001] The present invention relates to a hard coat film.

Background Art

[0002] In recent years, perovskite solar cells using perovskite compounds have rapidly attracted attention. It is known that perovskite solar cells are excellent in light energy conversion efficiency and can be easily manufactured into thin films by coating and drying a solution, similar to organic solar cells such as dye-sensitized solar cells and organic thin-film solar cells (Patent Document 1).

[0003] Modules of perovskite solar cells are known to be vulnerable to water vapor. Also, generally, elements used in electronic devices such as solar cells are susceptible to the influence of ultraviolet rays. For example, when a film-type solar cell is exposed to ultraviolet rays for a long time, there are problems such as a decrease in photoelectric conversion efficiency. Therefore, in addition to water vapor barrier performance, ultraviolet ray shielding performance is also required for the outermost layer of perovskite solar cell modules. To satisfy these performances, it is conceivable to laminate a film having gas barrier performance and a film having ultraviolet shielding performance. However, when simply laminating films having individual functions, not only does the cost increase, but there is also a problem that the thickness of the entire module increases.

[0004] Patent Document 2 describes a laminate obtained by laminating two transparent gas barrier films with an adhesive and further laminating a transparent resin film having ultraviolet cut-off properties, and then coating this laminate with an ultraviolet curable resin.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] The laminate described in Patent Document 2 has a structure in which films with different functions are bonded together with an adhesive, which raised concerns about increased costs. Furthermore, the total light transmittance was insufficient, and the water vapor barrier performance was not satisfactory.

[0007] Therefore, the present invention aims to provide a hard coat film that, when used in a solar cell, can provide gas barrier performance and ultraviolet shielding performance without increasing the number of components, and has a sufficiently high total light transmittance. [Means for solving the problem]

[0008] As a result of diligent research to achieve this objective, the inventors of the present invention have found that providing a gas barrier layer and a hard coat layer on the substrate and setting the light transmittance of a specific wavelength and the total light transmittance within a specific range is extremely effective, and have completed the present invention.

[0009] The present invention provides the following: (1) A hard coat film characterized by having a gas barrier layer on one side of a transparent substrate, a hard coat layer containing an ultraviolet-curable resin laminated on the other side of the transparent substrate, having a light transmittance of less than 10% at a wavelength of 365 nm, a light transmittance of 80% or more at a wavelength of 440 nm, and a total light transmittance of 80% or more. (2) The hard coat film according to (1), characterized in that the light transmittance at wavelengths of 365 to 380 nm is less than 25%, and the light transmittance at wavelengths of 436 to 440 nm is 75% or more. (3) The hard coat film according to (1) or (2), characterized in that the remaining percentage of the hard coat layer measured by the cross-cut method of JIS-K5600-5-6 is 100% with respect to the hard coat film. (4) A solar cell characterized by comprising the hard coat film described in (1) or (2). (5) The solar cell according to (4), which is a film-type solar cell having a film shape. [Effects of the Invention]

[0010] According to the present invention, when used in solar cells, it is possible to provide gas barrier performance and ultraviolet shielding performance without increasing the number of components, and to provide a hard coat film with sufficiently high total light transmittance. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view showing the schematic configuration of a hard coat film according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view showing the schematic configuration of the gas barrier layer laminated film (gas barrier film) of Comparative Example 2. [Figure 3] This is a cross-sectional view showing the schematic structure of the hard coat film of Comparative Example 3. [Modes for carrying out the invention]

[0012] The present invention will be described in detail below with reference to the drawings. In this invention, "~" includes the endpoints. That is, "X~Y" includes the values ​​X and Y at both ends.

[0013] The hard coat film of the present invention is characterized in that it has a gas barrier layer on one side of a transparent substrate, and a hard coat layer containing an ultraviolet-curable resin laminated on the other side of the transparent substrate, and has a light transmittance of less than 10% at a wavelength of 365 nm, a light transmittance of 80% or more at a wavelength of 440 nm, and a total light transmittance of 80% or more.

[0014] FIG. 1 is a cross-sectional view showing a schematic configuration of a hard coat film according to an embodiment of the present invention. As shown in FIG. 1, the hard coat film 2 has a gas barrier layer 6 on one surface of a transparent base film 4, and a hard coat layer 8 containing an ultraviolet curable resin is laminated on the other surface of the transparent base film 4.

[0015] (Transparent base material) The transparent base material used in the present invention may be formed from a transparent material capable of transmitting light in the visible wavelength range. The material of the transparent base material is not particularly limited. For example, polyethylene terephthalate (PET), cycloolefin, polyimide (PI), polyethylene naphthalate, polyethylene, polypropylene, polyether ether ketone (PEEK), acrylic resin, polystyrene, triacetyl cellulose, polyvinyl chloride, etc. can be mentioned. It is preferable to use films and sheets of the above transparent materials as the transparent base material. Also, from the viewpoint of transparency, it is preferable to use polyethylene terephthalate (PET), from the viewpoint of heat resistance, polyimide (PI), and polyether ether ketone (PEEK). Among them, from the viewpoints of processability and cost, polyethylene terephthalate (PET) is more preferable.

[0016] In the present invention, when the transparent base material is a film, the thickness of the transparent base material is preferably in the range of 10 μm to 1000 μm, and more preferably in the range of 20 μm to 300 μm, from the viewpoints of mechanical strength, handling property, etc.

[0017] In the present invention, the total light transmittance of the transparent base material is not particularly limited as long as the hard coat film within the scope of the present invention can be obtained, but it is preferably 80 to 100%, and more preferably 85 to 100%.

[0018] (Gas barrier layer) The gas barrier layer is preferably one that blocks water vapor and oxygen, and is particularly preferably one that is impermeable to water vapor, i.e., one with excellent water vapor barrier performance. For example, the gas barrier layer can be a layer containing silica or metal. The thickness of the gas barrier layer is not particularly limited, but is preferably in the range of 0.1 to 10 μm, and more preferably in the range of 0.2 to 1 μm. Below 0.1 μm, sufficient gas barrier performance tends not to be obtained, while above 10 μm, it tends to become heavy and loses its characteristics such as flexibility, permeability, and transmittance.

[0019] In this invention, when a gas barrier film is formed by forming a gas barrier layer on a transparent substrate film, the water vapor transmission rate at 40°C and 90% relative humidity is 1 × 10⁻⁶. -3 g / m 2 Preferably less than or equal to / day, 5 × 10 -4 g / m 2 It is more preferable that the value be less than or equal to / day. The water vapor transmission rate can be measured in accordance with ISO 15106.

[0020] The method for forming a gas barrier layer on a transparent substrate is not particularly limited and may be a dry method, a wet method, or a combination of both. Examples of dry methods for forming a gas barrier layer include resistance heating deposition, electron beam deposition, induction heating deposition, and vacuum deposition methods such as plasma or ion beam assistance; sputtering methods such as reactive sputtering, ion beam sputtering, and ECR (electron cyclotron) sputtering; physical vapor deposition (PVD) methods such as ion plating; and chemical vapor deposition (CVD) methods utilizing heat, light, or plasma. Examples of wet methods include coating by wet coating.

[0021] In the present invention, a commercially available gas barrier film having a gas barrier layer on a transparent substrate may be used.

[0022] (Hard coat layer) In this invention, the hard coat layer (hereinafter sometimes abbreviated as "HC layer") contains a UV-curable resin. This imparts surface hardness (pencil hardness, scratch resistance) to the hard coat layer, and also allows for adjustment of the degree of crosslinking by the amount of UV exposure, thereby enabling adjustment of the surface hardness of the hard coat layer.

[0023] The UV-curable resin used to form the hard coat layer is a transparent resin that hardens when irradiated with ultraviolet light (hereinafter sometimes abbreviated as "UV"), and preferably contains an acrylic resin, more preferably contains an acrylate resin, even more preferably contains an acrylate resin containing (meth)acryloyl groups, and particularly preferably is a urethane acrylate resin containing (meth)acryloyl groups.

[0024] Furthermore, in addition to UV-curing resins, thermoplastic resins such as polyethylene, polypropylene, polystyrene, polycarbonate, polyester, acrylic, styrene-acrylic, and cellulose, as well as thermosetting resins such as phenolic resins, urea resins, unsaturated polyesters, epoxy, and silicon resins, may be included in the hard coat layer, within a range that does not impair the effects of the present invention or the hardness of the hard coat layer.

[0025] Furthermore, while commercially available acetophenones such as IRGACURE 651 and IRGACURE 184 (both trade names: manufactured by BASF) and benzophenones such as IRGACURE 500 (trade name: manufactured by BASF) can be used as photopolymerization initiators for the UV-curable resin contained in the hard coat layer, there are no particular restrictions on the type of initiator used. However, it is preferable to use organic peroxides such as diacyl peroxides to further improve adhesion.

[0026] In the present invention, the hard coat layer preferably contains an ultraviolet absorber and / or a dye from the viewpoint of durability.

[0027] As for UV absorbers that can be included in the hard coat layer, UV absorbers having a maximum absorption wavelength (λmax) in the range of 275 to 415 nm, preferably 350 to 415 nm, are preferred. In the present invention, as organic UV absorbers, it is preferable to use, for example, benzotriazole-based UV absorbers and hydroxyphenyltriazine-based UV absorbers, and it is particularly preferable to use these benzotriazole-based UV absorbers and hydroxyphenyltriazine-based UV absorbers in combination. Furthermore, as inorganic UV absorbers, examples include inorganic particles such as titanium dioxide and cesium oxide.

[0028] The dyes that can be included in the hard coat layer are preferably those with a maximum absorption wavelength (λmax) in the range of 275 to 415 nm, more preferably 350 to 415 nm. In the present invention, for example, it is preferable to use cyanine dyes as such dyes.

[0029] In the present invention, when the above-mentioned ultraviolet absorber is included, the amount blended is preferably 1 to 30 parts by weight per 100 parts by weight of the ultraviolet-curable resin of the hard coat layer. If the amount of ultraviolet absorber is less than 1 part by weight, there is a risk of deterioration in durability. On the other hand, if the amount blended exceeds 30 parts by weight, the transmittance will decrease and the hardness and adhesion of the hard coat layer will be insufficient, making it unsuitable.

[0030] Furthermore, when the present invention includes the above-mentioned dye, the amount blended is preferably 0.1 to 10 parts by weight per 100 parts by weight of the UV-curable resin of the hard coat layer. If the amount of UV absorber is less than 0.1 parts by weight, there is a risk of deterioration in durability. On the other hand, if the amount blended exceeds 10 parts by weight, the transmittance will decrease, and the hardness and adhesion of the hard coat layer will be insufficient, making it unsuitable.

[0031] In the present invention, the water contact angle on the surface of the hard coat layer may be controlled by incorporating a surface modifier into the hard coat layer. Examples of surface modifiers used to increase the water contact angle on the surface of the hard coat layer include those containing silicone-containing polymers, fluorine-containing polymers, and acrylic-containing polymers, and from the viewpoint of water contact angle, it is preferable to use those containing silicone-containing polymers or fluorine-containing polymers. The amount of surface modifier to be blended can be appropriately determined, for example, according to the desired surface properties.

[0032] Other additives to be added to the hard coat layer may include, as needed, defoaming agents, antioxidants, antistatic agents, light stabilizers, etc., to the extent that they do not impair the effects of the present invention.

[0033] The hard coat layer described above is formed by dissolving and dispersing the aforementioned UV-curable resin, polymerization initiator, UV absorber (if necessary), dye, surface modifier, and other additives in a suitable solvent, applying the coating to the side of the transparent substrate opposite to the side where the gas barrier layer is formed, followed by drying and curing by UV irradiation. The solvent can be appropriately selected according to the solubility of the resin being blended, and should be a solvent that can uniformly dissolve or disperse at least the solid components (resin, polymerization initiator, UV absorber, dye, and other additives). Such solvents may include, for example, known organic solvents such as aromatic solvents like toluene, xylene, and n-heptane; aliphatic solvents like cyclohexane, methylcyclohexane, and ethylcyclohexane; ester solvents like methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and methyl lactate; ketone solvents like acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohol solvents like methanol, ethanol, isopropyl alcohol, and n-propyl alcohol; ether solvents like propylene glycol monomethyl ether; and amide solvents like dimethylformamide and diethylformamide, which can be used individually or in combination of several types as appropriate.

[0034] There are no particular limitations on the coating method for the hard coat layer described above, but examples include coating using known coating methods such as gravure coating, microgravure coating, fountain bar coating, slide die coating, slot die coating, screen printing, and spray coating, followed by drying at a temperature of approximately 50 to 120°C.

[0035] The amount of ultraviolet (UV) radiation applied after the formation of the hard coat layer should be sufficient to give the hard coat layer adequate hardness, and can be set appropriately depending on the type of UV-curable resin, etc.

[0036] The thickness of the hard coat layer described above is not particularly restricted, but it is preferably in the range of 1.0 μm to 20.0 μm. If the thickness is less than 1.0 μm, it becomes difficult to obtain the required surface hardness. Also, if the thickness exceeds 20.0 μm, the adhesion of the coating film decreases, which is undesirable. The thickness of the hard coat layer can be measured by actually measuring it with a micrometer.

[0037] (Method of manufacturing hard coat film) In the present invention, for example, a hard coat film can be manufactured by forming a gas barrier layer on one side of a transparent substrate film, applying a hard coat coating containing the above-mentioned UV-curable resin to the other side of the transparent substrate film, drying it, and then irradiating it with ultraviolet light, thereby causing photopolymerization and forming a coating film (hard coat layer) on the gas barrier film. Alternatively, a hard coat film can also be manufactured by applying a hard coat coating containing the above-mentioned UV-curable resin to the side of a commercially available gas barrier film (a transparent film with a gas barrier layer laminated on it) opposite to the side where the gas barrier layer is formed, drying it, and then irradiating it with ultraviolet light.

[0038] (Hard coat film) (Light transmittance) The hard coat film of the present invention has, from the viewpoint of durability, a light transmittance of less than 10% at a wavelength of 365 nm and a light transmittance of 80% or more at a wavelength of 440 nm, and from the viewpoint of power generation efficiency, a total light transmittance of 80% or more. Furthermore, the hard coat film of the present invention preferably has a light transmittance of less than 10% at a wavelength of 365 nm, more preferably less than 5%, even more preferably less than 3%, and particularly preferably less than 2%. Furthermore, the hard coat film of the present invention preferably has a total light transmittance of 85% or more, and even more preferably 90% or more. If the light transmittance at a wavelength of 365 nm is too high compared to the above upper limit, there is a risk of reduced durability, and if the light transmittance at a wavelength of 440 nm is too low compared to the above lower limit, there is a risk of reduced power generation efficiency. Furthermore, if the total light transmittance is too low compared to the above lower limit, there is a risk of reduced power generation efficiency.

[0039] From the viewpoint of durability, the hard coat film of the present invention preferably has a light transmittance of less than 25% at wavelengths of 365 to 380 nm, and more preferably less than 23%. In addition, the light transmittance at wavelengths of 436 to 440 nm is preferably 75% or more, and more preferably 79% or more. If the light transmittance at wavelengths of 365 to 380 nm is too high compared to the above upper limit, there is a risk of reduced durability. A lower light transmittance at wavelengths of 380 to 410 nm is even more preferable for improved durability. The light transmittance at wavelengths of 380 to 410 nm is preferably less than 25%, more preferably less than 15%, and even more preferably less than 10%. Furthermore, if the light transmittance at wavelengths of 436 to 440 nm is too low compared to the above lower limit, there is a risk of reduced power generation efficiency.

[0040] Regarding the hard coat film of the present invention, methods for adjusting the light transmittance at each wavelength include changing the type and amount of ultraviolet absorber and / or dye contained in the hard coat layer.

[0041] In the hard coat film of the present invention, from the viewpoint of preventing loss of functionality provided by the hard coat layer, it is preferable that the remaining percentage of the hard coat layer, as measured by the cross-cut method of JIS-K5600-5-6, is 75% or more, and more preferably 100%.

[0042] The hard coat film of the present invention may also include a configuration in which a hard coat layer containing an ultraviolet-curable resin is laminated on one side of a gas barrier film having gas barrier layers on both sides of a transparent substrate, as long as the optical properties (light transmittance and total light transmittance at each wavelength) of the present invention are within the range. Direct lamination of the hard coat layer on the gas barrier layer is undesirable because it may impair the adhesion of the hard coat layer.

[0043] The hard coat film of the present invention may further have a transparent electrode layer, as long as it satisfies the range of optical properties of the present invention.

[0044] (Application) The hard coat film of the present invention has a gas barrier layer and therefore exhibits excellent gas barrier performance against water vapor and other gases. Its optical properties (light transmittance at wavelengths of 365 nm and 440 nm, and total light transmittance) satisfy the scope of the present invention. Because it has low light transmittance in the ultraviolet wavelength range and high light transmittance and total light transmittance in the visible light wavelength range, it can be expected to achieve high power generation efficiency while suppressing degradation of the element due to ultraviolet light. Therefore, it is suitable as a component for solar cells, and especially as a protective film to be placed on the outermost layer of a solar cell module. Examples of solar cells are not limited to organic thin-film solar cells, dye-sensitized solar cells, perovskite solar cells, etc., and perovskite solar cells are preferred from the viewpoint of high energy conversion efficiency.

[0045] When the hard coat film of the present invention is used in a perovskite solar cell, for example, a solar cell can be manufactured by providing an electron transport layer, a perovskite layer, a hole transport layer, and an anode on a transparent electrode (cathode), and then laminating the hard coat film of the present invention on top of these. This solar cell may be a film-type solar cell having a film shape. [Examples]

[0046] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. Unless otherwise specified, the measurement / calculation methods for each numerical value in each example are as described in the specification. In the following description, "parts" refers to parts by weight unless otherwise specified, and "%" refers to percentage by weight unless otherwise specified.

[0047] (Example 1) (Preparation of coating liquid for hard coat layer formation) A coating solution for forming a hard coat layer (hereinafter referred to as "hard coat coating 1") was prepared by mixing 99.8 parts of an acrylate-based UV-curing resin coating containing an organic UV absorber (maximum absorption wavelength 350 nm) as the main component with 0.2 parts of a surface modifier (KP-106; manufactured by Shin-Etsu Chemical Co., Ltd.), and diluting it with methyl ethyl ketone / propylene glycol monomethyl ether = 88 / 12 (parts by weight) to a final solids content of 26%.

[0048] (Preparation of hard coat film) PET film with a gas barrier layer on one side (substrate thickness: 50 μm, water vapor transmission rate as gas barrier film: 5.0 × 10) -4 g / m 2 On the side opposite the gas barrier layer ( / day), the hard coat paint 1 described above was applied using a bar coater, and then dried with hot air in an 80°C drying oven for 1 minute to form a coating layer with a thickness of 2.0 μm. This was then subjected to UV irradiation at a UV irradiation dose of 150 mJ / cm² using a UV irradiation device set at a height of 60 mm above the coated surface. 2 The hard coat film of Example 1 was prepared by curing it with ultraviolet irradiation (see Figure 1).

[0049] (Example 2) (Preparation of coating liquid for hard coat layer formation) A coating solution for forming a hard coat layer (hereinafter referred to as "hard coat coating 2") was prepared by mixing 94.8 parts of an acrylate-based UV-curing resin coating containing an organic UV absorber (maximum absorption wavelength 350 nm) as the main component, adding 0.2 parts of a surface modifier (KP-106; manufactured by Shin-Etsu Chemical Co., Ltd.) and 5.0 parts of a cyanine dye (maximum absorption wavelength 395 nm), and diluting it with methyl ethyl ketone / propylene glycol monomethyl ether = 85 / 15 (parts by weight) to a final solids content of 26%.

[0050] (Preparation of hard coat film) The hard coat film of Example 2 was prepared in the same manner as in Example 1, except that hard coat coating 2 was used (see Figure 1).

[0051] (Example 3) (Preparation of coating liquid for hard coat layer formation) A coating solution for forming a hard coat layer (hereinafter referred to as "hard coat coating 3") was prepared by mixing 94.8 parts of an acrylate-based UV-curing resin coating containing an organic UV absorber (maximum absorption wavelength 350 nm) as the main component, 0.2 parts of a surface modifier (KP-106; manufactured by Shin-Etsu Chemical Co., Ltd.), and 5.0 parts of a cyanine dye (maximum absorption wavelength 405 nm) with n-propyl alcohol / dimethylformamide = 85 / 15 (parts by weight), and diluting it with n-propyl alcohol / dimethylformamide to a final solids content of 26%.

[0052] (Preparation of hard coat film) The hard coat film of Example 3 was prepared in the same manner as in Example 1, except that hard coat coating 3 was used (see Figure 1).

[0053] (Comparative Example 1) (Preparation of coating liquid for hard coat layer formation) A coating solution for forming a hard coat layer (hereinafter referred to as "hard coat coating 4") was prepared by mixing 99.8 parts of an acrylate-based UV-curing resin coating that does not contain UV absorbers as the main component, adding 0.2 parts of a surface modifier (KP-106; manufactured by Shin-Etsu Chemical Co., Ltd.), and diluting it with methyl ethyl ketone / propylene glycol monomethyl ether = 62 / 38 (parts by weight) to a final solids content of 26%.

[0054] (Preparation of hard coat film) A hard coat film of Comparative Example 1 was prepared in the same manner as in Example 1, except that hard coat coating 4 was used (see Figure 1).

[0055] (Comparative Example 2) The PET film (gas barrier film) with a gas barrier layer on one side used in Example 1 was used as the film for Comparative Example 2. Figure 2 shows the schematic configuration of the gas barrier layer laminated film (gas barrier film) 10 of Comparative Example 2. As shown in Figure 2, the gas barrier layer laminated film 10 has a gas barrier layer 6 laminated on one side of a transparent substrate film 4.

[0056] (Comparative Example 3) A hard coat film of Comparative Example 3 was prepared in the same manner as in Example 1, except that the hard coat coating 1 used in Example 1 was applied to the gas barrier layer surface of a PET film having a gas barrier layer on one side, also used in Example 1. Figure 3 shows the schematic configuration of the hard coat film 12 of Comparative Example 3. As shown in Figure 3, the hard coat film 12 has a gas barrier layer 6 and a hard coat layer 8 laminated on one side of a transparent substrate film 4.

[0057] <Rating> The films prepared in the examples and comparative examples described above were evaluated for the following items, and the results are shown in Table 1.

[0058] <Adhesion (Cross-cut method test conditions)> The hard coat layer of the film was laminated and tested in accordance with the cross-cut method described in JIS-K5600-5-6. A cross-cut peel test fixture was used, measuring 1 mm. 2 One hundred cross-cuts were prepared, and adhesive tape No. 252 manufactured by Sekisui Chemical Co., Ltd. was applied to them. After pressing evenly with a spatula, the adhesive tape was peeled off at a 60-degree angle, and the remaining rate of the hard coat layer (ratio of the number of remaining cross-cuts) was measured. The remaining rate was evaluated according to the following criteria. Note that this test was not performed on the film of Comparative Example 2 because it did not have a hard coat layer. ○: 100% retention rate of the hard coat layer (excellent adhesion of the hard coat layer) ×: Hard coat layer retention rate is less than 100% (poor adhesion of the hard coat layer)

[0059] <Total light transmittance> The total light transmittance of the films in each example and comparative example was measured using a haze meter (HM-150N, manufactured by Murakami Color Technology Laboratory Co., Ltd.). The measurements were performed in accordance with the JIS-K7361 standard.

[0060] <Light transmittance at each wavelength> The light transmittance of the films in each example and comparative example at each wavelength was measured using a Hitachi High-Technologies Corporation UH-4150 spectrophotometer. Measurements were performed in the wavelength range of 300 nm to 800 nm with a scan speed of 750 nm / min, and the light transmittance at each wavelength was detected.

[0061] [Table 1]

[0062] As can be seen from Table 1, the hard coat films of Examples 1 to 3, which have a gas barrier layer on one side of a transparent substrate and a hard coat layer containing an ultraviolet-curable resin laminated on the other side of the substrate, with a light transmittance of less than 10% at a wavelength of 365 nm and a light transmittance of 80% or more at a wavelength of 440 nm, and a total light transmittance of 80% or more, not only have excellent gas barrier properties but also excellent adhesion of the hard coat layer, and can be expected to maintain their ultraviolet shielding performance. [Explanation of symbols]

[0063] 2, 12…Hard coat film, 4…Transparent substrate film, 6…Gas barrier layer, 8…Hard coat layer, 10…Gas barrier layer laminated film (gas barrier film)

Claims

1. A hard coat film characterized by having a gas barrier layer on one side of a transparent substrate, a hard coat layer containing an ultraviolet-curable resin laminated on the other side of the transparent substrate, having a light transmittance of less than 10% at a wavelength of 365 nm, a light transmittance of 80% or more at a wavelength of 440 nm, and a total light transmittance of 80% or more.

2. The hard coat film according to claim 1, characterized in that the light transmittance at a wavelength of 365 to 380 nm is less than 25%, and the light transmittance at a wavelength of 436 to 440 nm is 75% or more.

3. The hard coat film according to claim 1 or 2, characterized in that the remaining percentage of the hard coat layer, as measured by the cross-cut method of JIS-K5600-5-6, is 100% with respect to the hard coat film.

4. A solar cell characterized by comprising the hard coat film described in claim 1 or 2.

5. The solar cell according to claim 4, which is a film-type solar cell having a film shape.

Images