Conductive film

Abstract

To provide a conductive film that has excellent antifouling properties without increasing the number of components when used for a solar battery.SOLUTION: A conductive film in which a conductive film is laminated on the other surface of a base material film which is equipped with a hard coat layer at least on the one surface, where when the water contact angle of the base material film is Fa, and the water contact angle of the hard coat layer A formed on the one surface is Ha, the contact angle is Fa<Ha.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a conductive film. [Background technology]

[0002] In recent years, perovskite solar cells using perovskite compounds have rapidly attracted attention. Perovskite solar cells are known to have excellent light energy conversion efficiency and to 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] There is a demand for improved power generation efficiency in perovskite solar cells, and various research efforts are being conducted to improve this efficiency.

[0004] Furthermore, when moisture such as rainwater adheres to the surface of a solar power generation module, the dirt contained in the moisture adheres to the surface of the module as the moisture evaporates, and this dirt blocks sunlight, resulting in a problem of reduced power generation efficiency.For example, Patent Document 2 describes that studies have been conducted to provide a sheet member with good lubricity. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-72327 [Patent Document 2] Japanese Patent Application Publication No. 2023-143607 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, when solar cells are installed and used outdoors, there is a need to prevent the adhesion of dirt caused by rainwater, etc. However, the method of Patent Document 2 increases the number of parts, which causes problems such as an increase in thickness when made into a battery and an increase in cost.

[0007] Therefore, an object of the present invention is to provide a conductive film that has excellent antifouling properties without increasing the number of components when used in a solar cell.

Means for Solving the Problems

[0008] As a result of intensive studies to achieve such an object, the present inventors have found that it is extremely effective to use a substrate film provided with a specific hard coat layer, and have completed the present invention.

[0009] The present invention provides the following. (1) A conductive film in which at least a conductive film is laminated on the other surface of a substrate film provided with a hard coat layer on at least one surface, wherein when the water contact angle of the substrate film is Fa and the water contact angle of the hard coat layer A formed on the one surface is Ha, a conductive film in which Fa < Ha. (2) The conductive film according to (1), wherein the water contact angle Ha is ˚ or more. (3) The conductive film according to (1) or (2), wherein the pencil hardness of the surface of the hard coat layer A is 2B or more. (4) The conductive film according to (1) or (2), wherein the hard coat layer contains a silicone-containing polymer or a fluorine-containing polymer. (5) On the other surface of the substrate film, a hard coat layer B is further provided between the substrate film and the conductive film, and when the surface roughness of the substrate film is Sz1 and the surface roughness of the hard coat layer B is Sz2, the conductive film according to (1) or (2), wherein Sz1 > Sz2. (6) The conductive film according to (1) or (2), wherein when the surface roughness of the substrate film is Sz1 and the surface roughness of the conductive film is Sz3, Sz1 > Sz3. (7) The conductive film according to (1) or (2), wherein the conductive film is one selected from the group consisting of ITO (indium tin oxide), FTO (fluorine-doped tin oxide), and ATO (antimony-doped tin oxide). (8) The conductive film according to (1) or (2), wherein the hard coat layer has a residual rate of 90% or more as measured by the cross-cut method of JIS-K5600-5-6. (9) The conductive film according to (1) or (2), wherein, when the total light transmittance of a hard coat film consisting of the hard coat layer and the substrate film constituting the conductive film is T and the total light transmittance of the substrate film is T0, (T0-T) / T0<10%. (10) The conductive film according to (1) or (2), which is used for a solar cell. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a conductive film that has excellent antifouling properties when used in a solar cell without increasing the number of components. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a conductive film according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

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

[0013] The conductive film of the present invention is a conductive film comprising a substrate film having a hard coat layer on at least one surface thereof and at least a conductive film laminated on the other surface thereof, wherein when the water contact angle of the substrate film is Fa and the water contact angle of the hard coat layer A formed on the one surface thereof is Ha, Fa <Haとなる。

[0014] (Conductive film) FIG. 1 is a cross-sectional view showing a schematic configuration of a conductive film according to an embodiment of the present invention. As shown in FIG. 1, a hard coat layer A6 is formed on one surface of a base film 4 of the conductive film 2. At least a conductive film 8 is laminated on the other surface of the base film 4. In another embodiment of the present invention, the other surface of the base film 4 may further include a hard coat layer B between the base film 4 and the conductive film 8.

[0015] In the conductive film 2 of the present invention, when the water contact angle of the base film 4 is Fa and the water contact angle of the hard coat layer A is Ha, the relationship Fa < Ha is satisfied.

[0016] In the conductive film 2 of the present invention, the water contact angle Ha of the hard coat layer A6 is preferably 95° or more, more preferably 97 to 130°, from the viewpoint of preventing dirt in the final product form. The water contact angle can be measured by a contact angle meter.

[0017] In the conductive film 2 of the present invention, the pencil hardness defined in JIS K5600-5-4 on the surface of the hard coat layer A6 is preferably 2B or more, more preferably B to 2H, from the viewpoints of preventing damage in the manufacturing process and preventing damage in the final product form.

[0018] (Base film) In the present invention, the base film to be used is not particularly limited, and examples thereof include polyethylene terephthalate (PET), cycloolefin, polyimide (PI), polyethylene naphthalate, polyethylene, polypropylene, polyether ether ketone (PEEK), acrylic resin, polystyrene, triacetyl cellulose, films and sheets of polyvinyl chloride, and the like. From the viewpoint of transparency, it is preferable to use polyethylene terephthalate (PET), from the viewpoint of heat resistance, polyimide (PI) or polyether ether ketone (PEEK), and among them, polyethylene terephthalate (PET) is more preferable from the viewpoints of processability and cost.

[0019] In the present invention, the thickness of the substrate film is preferably in the range of 10 μm to 1000 μm, more preferably in the range of 20 μm to 300 μm, from the viewpoints of mechanical strength, handleability, and the like.

[0020] In the present invention, the water contact angle Fa of the substrate film is not particularly limited, but is preferably from 70 to 90°, and more preferably from 70 to 80°.

[0021] In the present invention, the surface roughness Sz1 of the substrate film is not particularly limited, but is preferably from 40 to 4000 nm, and more preferably from 40 to 400 nm.

[0022] In the present invention, the total light transmittance T0 of the substrate film is not particularly limited, but is preferably from 80 to 100%, and more preferably from 85 to 100%.

[0023] In the present invention, when the substrate film is used as a conductive film for solar cells, in order to prevent deterioration of the coating film and poor adhesion due to ultraviolet rays, a resin obtained by kneading a resin constituting the substrate film with an ultraviolet absorber may be formed into a film, or a film may be used in which a coating material made by mixing a thermoplastic or thermosetting resin with an ultraviolet absorber is applied to one or both sides of the substrate film.

[0024] (Hard coat layer) In the present invention, the resin contained in the hard coat layer can be any resin that forms a coating, but it is preferable to use an ionizing radiation curable resin, since it can impart surface hardness to the hard coat layer and also allows the degree of crosslinking to be adjusted by the amount of exposure to ultraviolet light, thereby enabling adjustment of the surface hardness of the hard coat layer.

[0025] The ionizing radiation curable resin used to form the hard coat layer is a transparent resin that is cured by irradiation with ultraviolet light (hereinafter abbreviated as "UV") or electron beams (hereinafter abbreviated as "EB"), and preferably contains an acrylic resin, more preferably contains an acrylate resin, even more preferably contains an acrylate resin containing a (meth)acryloyl group, and particularly preferably is a urethane acrylate resin containing a (meth)acryloyl group.

[0026] In addition to the ionizing radiation curable resin, the resin contained in the hard coat layer may include thermoplastic resins such as polyethylene, polypropylene, polystyrene, polycarbonate, polyester, acrylic, styrene-acrylic, and cellulose, and thermosetting resins such as phenolic resin, urea resin, unsaturated polyester, epoxy, and silicone resin, within a range that does not impair the effects of the present invention or the hardness of the hard coat layer.

[0027] Furthermore, the photopolymerization initiator for the ionizing radiation curable resin contained in the hard coat layer is not particularly limited and may be a commercially available acetophenone such as IRGACURE 651 or IRGACURE 184 (both trade names: manufactured by BASF) or a benzophenone such as IRGACURE 500 (trade name: manufactured by BASF), but it is preferable to use an organic peroxide such as a diacyl peroxide in order to further improve adhesion.

[0028] In the present invention, it is also possible to control the water contact angle on the surface of the hard coat layer 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, acrylic-containing polymers, etc., and from the viewpoint of the water contact angle, it is preferable to use those containing silicone-containing polymers or fluorine-containing polymers.

[0029] Other additives that may be added to the hard coat layer include, if necessary, antifoaming agents, antioxidants, antistatic agents, ultraviolet absorbers, light stabilizers, and the like, within the scope of not impairing the effects of the present invention.

[0030] The hard coat layer is formed by coating the substrate film with a coating material prepared by dissolving or dispersing the ionizing radiation-curable resin, a polymerization initiator, a surface modifier (if necessary), and other additives in a suitable solvent, followed by drying. The solvent can be appropriately selected depending on the solubility of the resin to be blended, as long as it can uniformly dissolve or disperse at least the solid components (resin, polymerization initiator, and other additives). Examples of such solvents include known organic solvents, such as aromatic solvents (toluene, xylene, n-heptane, etc.); aliphatic solvents (cyclohexane, methylcyclohexane, ethylcyclohexane, etc.); ester solvents (methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl lactate, etc.); ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.); and alcohol solvents (methanol, ethanol, isopropyl alcohol, n-propyl alcohol, etc.). These solvents can be used alone or in combination.

[0031] The coating method for the hard coat layer is not particularly limited, but examples thereof include a method in which the hard coat layer is applied by a known coating method such as gravure coating, microgravure coating, fountain bar coating, slide die coating, slot die coating, screen printing, or spray coating, and then dried at a temperature of typically about 50 to 120°C.

[0032] The coating thickness of the hard coat layer is not particularly limited, but is preferably in the range of 1.0 μm to 20.0 μm. If the coating thickness is less than 1.0 μm, it becomes difficult to obtain the required surface hardness. If the coating thickness exceeds 20.0 μm, the adhesion of the coating film decreases, which is not preferable. The coating thickness of the hard coat layer can be measured by actual measurement using a micrometer.

[0033] In the present invention, for example, a hard coat layer coating material containing the above-mentioned ionizing radiation curable resin is applied to a substrate film, dried, and then irradiated with UV or EB to cause photopolymerization, thereby obtaining a hard coat film in which a coating film (hard coat layer) is formed on the substrate film, and this hard coat film can be used.

[0034] (Hard coat film) In the hard coat film that can be used in the present invention, from the viewpoint of preventing scratches during the manufacturing process and in the final product form, the pencil hardness of the hard coat layer, particularly the hard coat layer A described below, as specified in JIS K5600-5-4 is preferably 2B or more, and more preferably B to 2H.

[0035] In order to prevent loss of the functionality imparted by the coating film, the hard coat film that can be used in the present invention preferably has a hard coat layer retention rate of 90% or more, more preferably 95% or more, as measured by the cross-cut method of JIS-K5600-5-6.

[0036] From the viewpoint of power generation efficiency, the hard coat film that can be used in the present invention preferably satisfies (T0-T) / T0<10%, and more preferably (T0-T) / T0<5%, where T is the total light transmittance of the hard coat film and T0 is the total light transmittance of the base film.

[0037] The total light transmittance T of the hard coat film that can be used in the present invention is preferably 80% or more, more preferably 85 to 100%, from the viewpoint of power generation efficiency.

[0038] (Hard Coat Layer A) In the present invention, the hard coat layer formed on the surface of the substrate film opposite to the surface on which the conductive film is laminated is referred to as hard coat layer A. The hard coat layer A preferably contains the above-mentioned surface modifier from the viewpoints of increasing the water contact angle, preventing adhesion of rainwater and dirt, and suppressing a decrease in power generation efficiency when used in a solar cell. In this specification, the hard coat layer A may be referred to as a "water-sliding layer."

[0039] When the hard coat layer A contains a surface modifier, it is preferable to blend it in an amount of 0.1 to 1.0 mass % relative to the solid content of the resin contained in the hard coat paint, and more preferably 0.25 to 0.5 mass %, from the viewpoint of coating film adhesion and contact angle.

[0040] (Hard Coat Layer B) In the present invention, a hard coat layer may be provided between the substrate film and the conductive film. In this specification, the hard coat layer formed between the substrate film and the conductive film is referred to as hard coat layer B. From the viewpoint of smoothing the surface roughness on which the conductive film is laminated and improving the power generation efficiency when used in a solar cell, the surface roughness Sz2 of the hard coat layer B formed on the substrate film is preferably smaller than the surface roughness Sz1 of the substrate film, i.e., Sz1>Sz2, and more preferably 40 to 400 nm. In this specification, the hard coat layer B may be referred to as a "roughness control layer."

[0041] (Conductive film) The material for the conductive film is not particularly limited as long as it can form a conductive layer. Materials capable of forming a transparent layer are preferred. Examples of suitable materials include metal oxides such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), tin dioxide (SnO), and zinc oxide (ZnO). Other suitable materials include at least one metal selected from the group consisting of gold, silver, copper, aluminum, tungsten, nickel, and chromium, as well as carbon materials, conductive polymer materials, and semiconductor materials that can be formed by the sol-gel method. From the viewpoints of transparency and conductivity, it is preferable to use indium tin oxide (ITO), fluorine-doped tin oxide (FTO), or antimony-doped tin oxide (ATO). The conductive film may be made of one or more materials. The thickness of the conductive film is not particularly limited, and is preferably, for example, 100 nm to 500 nm.

[0042] In the present invention, the surface roughness Sz3 of the conductive film is preferably smaller than the surface roughness Sz1 of the substrate film, i.e., Sz1>Sz3, and more preferably 40 to 400 nm, from the viewpoint that poor flatness can cause a problem of reduced efficiency.

[0043] (Conductive film manufacturing method) The method for producing the conductive film of the present invention is not particularly limited. For example, a hard coat layer A is provided on one surface (side A) of a substrate film, and then a hard coat layer B is provided on the other surface (side B) of the substrate film as needed, and then a conductive film material such as ITO is sputtered onto the side B of the substrate film to obtain a conductive film.

[0044] The conductive film of the present invention has a hard coat layer A formed on one surface of a substrate film, and the water contact angle of the hard coat layer A is larger than the water contact angle of the substrate film. When used in a solar cell, the hard coat layer A can prevent adhesion of rainwater and dirt and suppress a decrease in power generation efficiency.

[0045] (Application) The conductive film of the present invention has the effect of suppressing a decrease in power generation efficiency as described above, and is therefore suitable as a member for solar cells. Examples of solar cells include, but are not limited to, organic thin-film solar cells, dye-sensitized solar cells, and perovskite solar cells, and from the viewpoint of high energy conversion efficiency, perovskite solar cells are preferred.

[0046] When the conductive film of the present invention is used in a perovskite solar cell, for example, an electron transport layer, a perovskite layer, a hole transport layer, and another conductive film can be provided on the conductive film of the conductive film to produce a solar cell (photoelectric conversion element). [Example]

[0047] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In addition, unless the method for measuring / calculating each value in each example is specifically stated, it was measured / calculated by the method described in the specification.

[0048] Example 1 (Preparation of Coating Solution for Forming Hard Coat Layer) A hard coat layer-forming coating solution 1 (hereinafter also referred to as "hard coat coating material 1") containing an acrylate-based ultraviolet-curable resin coating material (TOMAX, manufactured by Nippon Kako Toryo Co., Ltd.) as the main component was prepared.

[0049] (Preparation of hard coat film) The hard coat paint 1 was applied to one side (side A) of a 125 μm thick polyethylene terephthalate film (hereinafter also referred to as "PET film") (Cosmoshine A4360; manufactured by Toyobo Co., Ltd.) as a substrate film using a bar coater, and the hard coat paint 1 was dried with hot air in a drying oven at 80°C for 1 minute to form a coating layer with a coating thickness of 3.0 μm. This was then exposed to UV irradiation at a dose of 300 mJ / cm using a UV irradiation device set at a height of 60 mm from the coated surface. 2 The resulting hard coat film was cured by irradiation with ultraviolet light of 1000 kJ / cm 2 , thereby producing a hard coat film in which a hard coat layer A (hereinafter also referred to as "HC layer A") was formed on the A side of the substrate film.

[0050] (Preparation of conductive film) ITO (Indium Tin Oxide) was sputtered onto the backside (side B) of the hard-coated film prepared above using a sputtering device (MSP-40T, Vacuum Devices Co., Ltd.) to prepare a conductive film laminated with ITO to a thickness of 200 nm.

[0051] Example 2 A surface modifier containing a fluorine-containing polymer (Megafac RS-75-A; manufactured by DIC Corporation) was added to the hard coat coating material 1 described in Example 1 in an amount of 0.25% based on solids to prepare a hard coat layer-forming coating solution 2 (hereinafter also referred to as "hard coat coating material 2"). A hard coat film having a hard coat layer A formed on side A of a substrate film was produced in the same manner as in the hard coat film production method described in Example 1, except that hard coat coating material 2 was used instead of hard coat coating material 1. ITO was sputtered onto side B of the obtained hard coat film in accordance with the method for producing the conductive film in Example 1, thereby producing a conductive film.

[0052] Example 3 A surface modifier containing a silicone-containing polymer (GL-02R; manufactured by Kyoeisha Chemical Co., Ltd.) was added to the hard coat coating material 1 described in Example 1 in an amount of 0.50% based on solids to prepare a hard coat layer-forming coating solution 3 (hereinafter also referred to as "hard coat coating material 3"). A hard coat film having a hard coat layer A formed on side A of a substrate film was produced in the same manner as in the hard coat film production method described in Example 1, except that hard coat coating material 3 was used instead of hard coat coating material 1. ITO was sputtered onto side B of the obtained hard coat film in accordance with the method for producing the conductive film in Example 1, thereby producing a conductive film.

[0053] Example 4 For the hard coat film described in Example 1, hard coat paint 1 was applied to the side (side B) opposite to the side on which hard coat layer A was provided (side A) in accordance with the preparation method described in Example 1, thereby producing a double-sided hard coat film in which hard coat layer B (hereinafter also referred to as "HC layer B") was formed on side B of the base film. ITO was sputtered onto side B of the obtained double-sided hard coat film in accordance with the preparation method for the conductive film of Example 1, thereby producing a conductive film.

[0054] Example 5 For the hard coat film described in Example 2, hard coat paint 1 was applied to the side (side B) opposite to the side on which hard coat layer A was provided (side A) in accordance with the preparation method described in Example 1, thereby producing a double-sided hard coat film in which hard coat layer B was formed on side B of the base film. ITO was sputtered onto side B of the obtained double-sided hard coat film in accordance with the preparation method for the conductive film of Example 1, thereby producing a conductive film.

[0055] Example 6 For the hard coat film described in Example 3, hard coat paint 1 was applied to the side (side B) opposite to the side on which hard coat layer A was provided (side A) in accordance with the preparation method described in Example 1, thereby producing a double-sided hard coat film in which hard coat layer B was formed on side B of the base film. ITO was sputtered onto side B of the obtained double-sided hard coat film in accordance with the preparation method for the conductive film of Example 1, thereby producing a conductive film.

[0056] Example 7 A hard coat film was prepared in the same manner as in Example 2, except that a 50 μm thick polyimide film (Kapton; manufactured by Toray DuPont) was used as the substrate film, and a conductive film was prepared using this hard coat film.

[0057] Example 8 A hard coat film was prepared in the same manner as in Example 3, except that a 50 μm thick polyimide film (Kapton; manufactured by Toray DuPont) was used as the substrate film, and a conductive film was prepared using this hard coat film.

[0058] Example 9 A hard coat film was prepared in the same manner as in Example 5, except that a 50 μm thick polyimide film (Kapton; manufactured by Toray DuPont) was used as the substrate film, and a conductive film was prepared using this hard coat film.

[0059] Example 10 A hard coat film was prepared in the same manner as in Example 6, except that a 50 μm thick polyimide film (Kapton; manufactured by Toray DuPont) was used as the substrate film, and a conductive film was prepared using this hard coat film.

[0060] Example 11 A hard coat film was prepared in the same manner as in Example 2, except that a 200 μm thick polyether ether ketone film (manufactured by Polypla-Evonik Co., Ltd.) was used as the substrate film, and a conductive film was prepared using this hard coat film.

[0061] Example 12 A hard coat film was prepared in the same manner as in Example 3, except that a 200 μm thick polyether ether ketone film (manufactured by Polypla-Evonik Co., Ltd.) was used as the substrate film, and a conductive film was prepared using this hard coat film.

[0062] Example 13 A hard coat film was prepared in the same manner as in Example 5, except that a 200 μm thick polyether ether ketone film (manufactured by Polypla-Evonik Co., Ltd.) was used as the substrate film, and a conductive film was prepared using this hard coat film.

[0063] Example 14 A hard coat film was prepared in the same manner as in Example 6, except that a 200 μm thick polyether ether ketone film (manufactured by Polypla-Evonik Co., Ltd.) was used as the substrate film, and a conductive film was prepared using this hard coat film.

[0064] (Comparative Example 1) A conductive film with a 200-nm-thick ITO layer was fabricated by sputtering ITO (indium tin oxide) onto one side (side B) of a 125-μm-thick PET film (Cosmoshine A4360; manufactured by Toyobo Co., Ltd.) using a sputtering device (MSP-40T, Vacuum Devices Co., Ltd.).

[0065] (Comparative Example 2) A conductive film with a 200 nm thick ITO layer was fabricated by sputtering ITO (indium tin oxide) onto one side (side B) of a 50 μm thick polyimide film (Kapton; manufactured by Toray DuPont) using a sputtering system (MSP-40T, Vacuum Devices Co., Ltd.).

[0066] (Comparative Example 3) A conductive film with a 200-nm-thick ITO layer was fabricated by sputtering ITO (indium tin oxide) onto one side (side B) of a 200-μm-thick polyether ether ketone film (Polypla-Evonik Co., Ltd.) using a sputtering system (MSP-40T, Vacuum Device Co., Ltd.).

[0067] <Evaluation> The conductive films or hard coat films of the Examples and Comparative Examples prepared as described above were evaluated for the following items, and the results are shown in Tables 1 and 2.

[0068] <Water contact angle measurement> 2 μL of water (pure water) was dropped onto surface A of the conductive film, and the contact angle was measured after 1 second using a fully automatic contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd.). The contact angle of the substrate film was also measured in the same manner. The water contact angle of the substrate film was designated Fa, and the water contact angle of the hard coat layer A was designated Ha.

[0069] <Pencil hardness measurement> The pencil hardness of side A of the conductive film was measured using a test method in accordance with JIS-K-5600-5-4. The hardness at which no scratches were generated on the surface was recorded as the result. Note that ">6B" means that scratches were generated even when using the softest 6B pencil.

[0070] <Cross-cut method test> The test was carried out on side A of the hard coat film in accordance with the cross-cut method described in JIS-K5600-5-6. 2 One hundred cross-cuts of the above were prepared, and adhesive tape No. 252 manufactured by Sekisui Chemical Co., Ltd. was attached thereon and pressed evenly using a spatula. The adhesive tape was then peeled off in a 60-degree direction, and the remaining rate of the hard coat layer A (the ratio of the number of remaining cross-cuts) was measured.

[0071] <Surface roughness measurement> The maximum height Sz was measured using a nano 3D optical interferometry system VS1800 manufactured by Hitachi High-Tech Science Corp. The surface roughness Sz1 of each substrate film was used as the reference, and the surface roughness Sz2 of the hard coat layer B (roughness control layer) and the surface roughness Sz3 of the conductive film were expressed as a ratio to Sz1.

[0072] <Total light transmittance> The total light transmittance of each hard coat film and substrate film was measured using a haze meter (HM-150N, manufactured by Murakami Color Research Laboratory Co., Ltd.). The measurement was carried out in accordance with the JIS-K7361 standard. The total light transmittance of the hard coat film was T and the total light transmittance of the substrate film was T, and the ratio (T0-T) / T0 was calculated.

[0073] <Outdoor Exposure Test> The sample was placed outdoors without obstacles at a south-facing angle of 45° (with the A side of the conductive film facing upward), and it was judged based on the presence or absence of dust adhesion that would damage the appearance after two weeks. (〇: No dust adhesion that damages the appearance, ×: Dust adhesion that damages the appearance)

[0074]

Table 1

[0075]

Table 2

[0076] As can be seen from Tables 1 and 2, for the conductive film having a hard coat layer A (water-slipping layer) on one side of the base film and at least a conductive film laminated on the other side, when the water contact angle of the base film is Fa and the water contact angle of the hard coat layer A is Ha, the conductive films of Examples 1 to 14 where Fa < Ha used base films of the same material and had better appearance after the outdoor exposure test compared to the conductive films of the comparative examples without the hard coat layer A. [[ID=二十五]]

Explanation of Reference Signs

[0077] 2…Conductive film, 4…Base film, 6…Hard coat layer A, 8…Conductive film

Claims

1. A conductive film comprising a substrate film having a hard coat layer on at least one surface thereof and at least a conductive film laminated on the other surface thereof, A conductive film in which Fa<Ha is satisfied when Fa is the water contact angle of the substrate film and Ha is the water contact angle of the hard coat layer A formed on one surface of the substrate film.

2. The conductive film according to claim 1 , wherein the water contact angle Ha is 95° or more.

3. 3. The conductive film according to claim 1, wherein the surface of said hard coat layer A has a pencil hardness of 2B or more.

4. The conductive film according to claim 1 or 2, wherein the hard coat layer comprises a silicone-containing polymer or a fluorine-containing polymer.

5. a hard coat layer B is further provided between the substrate film and the conductive film on the other surface of the substrate film, 3. The conductive film according to claim 1, wherein when the surface roughness of the substrate film is Sz1 and the surface roughness of the hard coat layer B is Sz2, Sz1>Sz2.

6. 3. The conductive film according to claim 1, wherein when the surface roughness of the substrate film is Sz1 and the surface roughness of the conductive film is Sz3, Sz1>Sz3.

7. 3. The conductive film according to claim 1, wherein the conductive film is one selected from the group consisting of ITO (indium tin oxide), FTO (fluorine-doped tin oxide), and ATO (antimony-doped tin oxide).

8. 3. The conductive film according to claim 1, wherein the hard coat layer has a residual rate of 90% or more as measured by the cross-cut method of JIS-K5600-5-6.

9. 3. The conductive film according to claim 1, wherein, when a total light transmittance of a hard coat film consisting of the hard coat layer and the base film constituting the conductive film is T and a total light transmittance of the base film is T0, (T0-T) / T0<10%.

10. The conductive film according to claim 1 or 2, which is used for a solar cell.

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