Light shielding film and lens unit

Abstract

To prove a light shielding film capable of achieving both low reflectance and workability.SOLUTION: A light shielding film includes a base material having light shielding properties and an anti-glossy layer arranged to be superimposed on the base material. The anti-glossy layer is more transparent than the base material; the optical density value of the light shielding film in a wave length of 380 nm or more and 780 nm or less is 4.0 or more; the glossiness of at least one surface in the surfaces of the anti-glossy layer at an incident angle of 60 degrees is 0.0% or more and 10.0% or less; and the surface resistance value of the light shielding film is 1.0×105 Ω / sq. or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a light-shielding film and a lens unit. [Background technology]

[0002] Light-shielding members are used as shutters, diaphragm members, or gap adjustment members disposed between multiple lenses in optical components provided in smartphones, digital video cameras, etc. Light-shielding members are manufactured using, for example, a light-shielding film that includes a sheet-like substrate and a light-shielding layer disposed on the surface of the substrate. For example, Patent Document 1 discloses a light-shielding film essentially containing an organic resin and a black material, wherein the organic resin contains a cured product of a curable resin or a thermoplastic resin having a glass transition temperature of 150° C. or higher. However, such a light-shielding film has a drawback in that it has a relatively high reflectance.

[0003] On the other hand, Patent Document 2 discloses a light-shielding film that includes a sheet-like substrate having light-shielding properties and an anti-gloss layer that is overlaid on the substrate, has irregularities formed on the surface opposite to the substrate, and is more transparent than the substrate, the anti-gloss layer including a binder resin, filler particles dispersed in the binder resin, and a coloring component dispersed in the binder resin, and has a blackness within a predetermined range. By providing the anti-gloss layer, low reflectance is achieved. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2010-534342 [Patent Document 2] Japanese Patent Application Publication No. 2022-137471 Summary of the Invention [Problem to be solved by the invention]

[0005] The light-shielding film of Patent Document 2 only achieves a predetermined blackness range by providing an anti-gloss layer with a textured surface, and no consideration has been given to the anti-static function of the light-shielding film. After consideration, the inventors have recognized that the light-shielding film of Patent Document 2 has poor anti-static function and sticks to unintended locations due to the effects of static electricity, etc., resulting in poor workability. Workability refers to the property of making it easy to position the light-shielding film in the desired location, for example, when the light-shielding film is used in a shutter for an optical component.

[0006] An object of the present disclosure is to provide a light-shielding film that combines low reflectance with workability, and a lens unit that includes the light-shielding film of the present disclosure. [Means for solving the problem]

[0007] The present disclosure relates to the following: [1] A light-shielding film comprising a substrate having light-shielding properties and an anti-gloss layer disposed on the substrate, the anti-gloss layer is more transparent than the substrate; The optical density of the light-shielding film is 4.0 or more at a wavelength of 380 nm or more and 780 nm or less, the gloss of at least one surface of the antigloss layer at an incident angle of 60 degrees is 0.0% or more and 10.0% or less; The surface resistance of the light-shielding film is 1.0×10 5 A light-blocking film with a resistance of Ω / □ or less. [2] The light-shielding film according to [1], wherein the substrate has antistatic properties. [3] The light-shielding film according to [1] or [2], wherein the substrate contains carbon black. [4] The light-shielding film according to any one of [1] to [3], wherein the antigloss layer contains carbon black, and the content of the carbon black in the antigloss layer is greater than 0% by mass and not more than 5% by mass. [5] The light-shielding film according to any one of [1] to [4], wherein the antigloss layer contains a binder resin and particles dispersed within the binder resin. [6] The light-shielding film according to any one of [1] to [5], wherein the thickness of the light-shielding film is 35 μm or less. [7] The light-shielding film according to any one of [1] to [6], wherein the thickness of the substrate is 2 μm or more and 30 μm or less. [8] The light-shielding film according to any one of [1] to [7], wherein the thickness of the antigloss layer is 1 μm or more and 7 μm or less. [9] The light-shielding film according to any one of [1] to [8], which is a shutter of an optical component, a diaphragm member, or a gap adjusting member disposed between a plurality of lenses.

[10] A lens unit including the light-shielding film according to [9]. [Effects of the Invention]

[0008] According to the present disclosure, a light-shielding film that achieves both low reflectance and workability is provided, and a lens unit including the light-shielding film of the present disclosure is also provided. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a light-shielding film according to one embodiment of the present disclosure. [Figure 2] 1 is a cross-sectional view of a light-shielding film according to one embodiment of the present disclosure. [Figure 3] FIG. 2 is an exploded view of a lens unit according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present disclosure will be described below based on specific embodiments. In this specification, when a numerical range is described with a lower limit and an upper limit separately, the numerical range can be a combination of any of the lower limit and any of the upper limit. In this disclosure, a numerical range expressed using "A to B" means a numerical range that includes the lower and upper limits, which are the endpoints. In the present disclosure, the unit of surface resistance, Ω / □, indicates Ω / square.

[0011] The light-shielding film of the present disclosure is a light-shielding film including a substrate having light-shielding properties and an anti-gloss layer disposed on the substrate. The anti-gloss layer is more transparent than the substrate. Furthermore, the light-shielding film has an optical density value of 4.0 or more at a wavelength of 380 nm or more and 780 nm or less. Furthermore, at least one surface of the anti-gloss layer has a glossiness of 0.0% or more and 10.0% or less at an incident angle of 60 degrees. In addition, the surface resistance of the light-shielding film is 1.0 × 10 5 It is Ω / □ or less.

[0012] As described above, the substrate has light-blocking properties, and the anti-gloss layer is more transparent than the substrate. This allows the light-blocking properties of the substrate to be displayed externally through the anti-gloss layer. As a result, the light-blocking film has low brightness and excellent light-blocking properties. Furthermore, an optical density value of 4.0 or higher at a wavelength of 380 nm or more and 780 nm or less indicates high blackness and that the light-blocking film is jet black, indicating that the light-blocking film has excellent light-blocking properties. Furthermore, the glossiness of at least one surface of the antigloss layer at an incident angle of 60 degrees is 0.0% or more and 10.0% or less, which indicates that the antigloss layer has excellent antigloss properties, which tends to reduce the reflectance of the light-shielding film. And the surface resistance of the light-shielding film is 1.0 × 10 5 A resistance of Ω / □ or less indicates that the light-shielding film has high antistatic properties, which makes it easier to produce a light-shielding film with excellent workability. The light-shielding film of the present disclosure can be used as a shutter in an optical component, a diaphragm member, or a gap adjustment member disposed between multiple lenses.

[0013] Fig. 1 is a cross-sectional view of a light-shielding film 100 according to one embodiment of the present disclosure. The light-shielding film 100 includes a substrate 101 having light-shielding properties and an antigloss layer 102 disposed on the substrate. In Fig. 1, a first antigloss layer and a second antigloss layer are laminated on both sides of the substrate 101, but the antigloss layer may be laminated on only one side of the substrate 101 having light-shielding properties. Each layer that may constitute the light-shielding film will now be described.

[0014] (base material) The substrate supports the anti-gloss layer. The substrate may be a single layer or may have multiple layers. When the substrate is a single layer, the material used for the substrate is not particularly limited, but it preferably contains a resin and a colorant. The resin is not particularly limited, but one or more resins selected from the group consisting of polyethylene terephthalate (PET), polyimide (PI), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), polycarbonate (PC), and ethylene-methacrylic acid copolymer (EMAA) are preferred, with PET being more preferred.

[0015] When the substrate is a single layer and contains a resin, the content of the resin in the substrate is not particularly limited, but is preferably 50% by mass or more and 100% by mass or less, and more preferably 60% by mass or more and 100% by mass or less.

[0016] The colorant is not particularly limited, but examples thereof include carbon black. The carbon black is not particularly limited, and examples thereof include furnace black, thermal black, lamp black, and conductive carbon black such as acetylene black and ketjen black. From the viewpoint of adjusting the surface resistance of the substrate, conductive particles such as conductive carbon black are preferred as the colorant, and conductive carbon black is more preferred. Specific examples of conductive carbon black include Denka Black (registered trademark) (manufactured by Denka Co., Ltd.), Ketjen Black EC (manufactured by Lion Specialty Chemicals Co., Ltd.), and Ketjen Black EC-600D (manufactured by Lion Specialty Chemicals Co., Ltd.). Alternatively, a dispersion of conductive carbon black may be used, such as MHI Black #273 (manufactured by Mikuni Color Co., Ltd.).

[0017] When the substrate is a single layer and contains a colorant, the content of the colorant in the substrate is not particularly limited, but is preferably more than 0% by mass and not more than 50% by mass, and more preferably 1% by mass or more and not more than 40% by mass. Within this range, the light-blocking properties of the substrate are favorable.

[0018] When the substrate is a single layer and contains a colorant, and the colorant is carbon black, the content of carbon black in the substrate is not particularly limited, but is preferably more than 0% by mass and not more than 50% by mass, more preferably 1% by mass or more and not more than 40% by mass, even more preferably 10% by mass or more and not more than 40% by mass, and particularly preferably 25% by mass or more and not more than 40% by mass. Within the above range, the conductivity of the substrate becomes more favorable, and the surface resistance value of the light-shielding film tends to fall within the range described below.

[0019] As described above, the substrate has a light-shielding property. , indicates that the optical density value described below is 2.0 or more. Furthermore, the optical density value of the substrate is preferably 3.0 or more, more preferably 4.0 or more. The upper limit is not particularly limited, but may be 3.0 or more and 10.0 or less, or 4.0 or more and 10.0 or less. A substrate having light-blocking properties can be obtained by using a material having light-blocking properties as the material for the substrate. For example, a metal foil such as aluminum foil or a substrate containing a colorant can be a substrate having light-blocking properties. The substrate may also have a plurality of layers, one or more of which may have light-blocking properties, thereby forming a substrate having light-blocking properties. An embodiment of a substrate having a plurality of layers will be described later.

[0020] The substrate may contain conductive particles other than conductive carbon black. Such conductive particles are not particularly limited, but examples thereof include particles of metals such as gold, silver, copper, and nickel. By containing the conductive particles in the substrate, the surface resistance of the substrate can be easily adjusted to the range described below. The content of conductive particles other than conductive carbon black in the substrate is not particularly limited, but is preferably greater than 0% by mass and less than 50% by mass, more preferably from 1% to 40% by mass, even more preferably from 10% to 40% by mass, and particularly preferably from 25% to 40% by mass. Within the above range, the conductivity of the substrate becomes more favorable, and the surface resistance of the light-shielding film tends to fall within the range described below.

[0021] The substrate may contain other materials, and may also contain various additives such as antioxidants, ultraviolet absorbers, heat stabilizers, plasticizers, lubricants, and flame retardants. The shape of the substrate is not particularly limited, but is preferably a film, for example. The thickness of the substrate is not particularly limited, but may be, for example, 2 μm to 30 μm, 2 μm to 20 μm, or 5 μm to 15 μm.

[0022] The substrate preferably has antistatic properties. When the substrate has antistatic properties, workability is likely to be improved. The substrate has antistatic properties when the surface resistance value of the substrate is 1.0 × 10 11 Indicates that the resistance is Ω / □ or less. The surface resistance of the substrate is 1.0 x 10 10 It is more preferable that it is Ω / □ or less, and 1.0×10 9 It is more preferable that the resistance is Ω / □ or less, and 1.0×10 7 It is particularly preferable that the resistance is Ω / □ or less, and 1.0×10 6 It is particularly preferable that the surface resistance of the light-shielding film is Ω / □ or less. Within this range, it is easy to adjust the surface resistance of the light-shielding film to the range described below. The lower limit is not particularly limited, but is preferably 1.0 × 10 -3 ~1.0×10 11 Ω / □, 1.0×10 -2 ~1.0×10 10 Ω / □, 1.0×10 -1 ~1.0×10 9 Ω / □, 1.0×10 0 ~1.0×10 7 Ω / □, 1.0×10 1 ~1.0×10 6 It may be Ω / □. The surface resistance of the substrate can be adjusted by changing the type and content of the material used in the substrate. For example, if the substrate contains conductive particles, the surface resistance of the substrate can be easily adjusted to the above range. Furthermore, when the substrate having light-shielding properties contains conductive particles, the surface resistance can be reduced by increasing the content of conductive particles in the substrate or using conductive particles with high conductivity, and the surface resistance can be increased by decreasing the content of conductive particles or using conductive particles with low conductivity. The method for measuring the surface resistance of the substrate will be described later.

[0023] (anti-gloss layer) The antigloss layer 102 is more transparent than the substrate 101. Whether the antigloss layer 102 is more transparent than the substrate 101 can be confirmed by measuring the total light transmittance of the antigloss layer 102 and the substrate 101. In other words, when the total light transmittance of the antigloss layer 102 is higher than the total light transmittance of the substrate 101, it can be said that the antigloss layer 102 is more transparent than the substrate 101. The total light transmittance refers to the transmittance measured by a method in accordance with JIS K 7375:2008. The total light transmittance of the substrate and the anti-gloss layer can be varied by changing the type and content of the materials used. For example, when the content of the colorant that can be contained in the antigloss layer is made smaller than the content of the colorant that can be contained in the substrate, the total light transmittance of the antigloss layer tends to be higher than that of the substrate.

[0024] The anti-gloss layer 102 is disposed on the substrate 101. The anti-gloss layer 102 is a layer that scatters light incident on the light-shielding film 100 to prevent the light-shielding film 100 from becoming glossy. The anti-gloss layer 102 is not particularly limited as long as it can prevent the light-shielding film from becoming glossy, but it is preferable that the anti-gloss layer 102 has an uneven surface formed on the surface opposite to the substrate 101. When such uneven surface is formed, it is easier to prevent the light-shielding film from becoming glossy. The method for forming the irregularities is not particularly limited, and known means can be used, such as a method of incorporating particles described below into the antigloss layer, a method of transferring an irregularity pattern to the antigloss layer, or a method of incorporating multiple binder resins into the antigloss layer to form a phase-separated structure. Here, the phase-separated structure can be formed, for example, by spinodal decomposition (wet spinodal decomposition) from the liquid phase of the coating liquid for forming the antigloss layer. For details of the phase-separated structure, see, for example, Japanese Patent No. 6190581.

[0025] The material of the antigloss layer is not particularly limited, but preferably contains a binder resin and a colorant. The binder resin is not particularly limited, but examples thereof include one or more resins selected from the group consisting of thermoplastic resins, thermosetting resins, and photocurable resins. When the antigloss layer contains a binder resin, the content of the binder resin in the antigloss layer is not particularly limited, but is preferably 40% by mass or more and 100% by mass or less, and more preferably 50% by mass or more and 90% by mass or less.

[0026] Examples of thermoplastic resins include polyolefins, styrene resins, acrylic resins, vinyl chloride resins, polyvinyl alcohol resins, polyacetal resins, saturated polyester resins, polycarbonate resins, polyamide resins, polyimide resins, polysulfone resins, polyphenylene ether resins, polyphenylene sulfide resins, fluororesins, cellulose derivatives, and thermoplastic polyurethane resins.

[0027] Examples of thermosetting resins include phenolic resins, melamine resins, urea resins, benzoguanamine resins, silicone resins, epoxy resins, unsaturated polyester resins, vinyl ester resins, and thermosetting polyurethane resins. Examples of thermosetting polyurethane resins include urethane resins and urethane acrylic resins. Among these, urethane acrylic resins are preferred.

[0028] Examples of photocurable resins include photocurable polyester resins, photocurable acrylic resins, photocurable epoxy (meth)acrylate resins, photocurable urethane (meth)acrylate resins, etc. Here, "photocurable" refers to the property of a monomer being polymerized and hardened by light of a specific wavelength.

[0029] The colorant is not particularly limited, and examples thereof include carbon black. As the carbon black, those described in the description of the substrate can be used, and from the viewpoint of adjusting the surface resistance value of the light-shielding film, conductive particles such as conductive carbon black are preferred, and conductive carbon black is more preferred. When the antigloss layer contains carbon black, the content of carbon black in the antigloss layer is not particularly limited, but is preferably more than 0% by mass and not more than 5% by mass, and more preferably 2% by mass or more and not more than 5% by mass. Within this range, the optical density value of the light-shielding film tends to fall within the range described below.

[0030] The anti-gloss layer contains a binder resin and particles dispersed in the binder resin. It is preferable that the anti-gloss layer has a thickness of 1000 nm or less. This makes it easier to form irregularities on the surface of the anti-gloss layer, making it easier to prevent the gloss of the light-shielding film. The particles are not particularly limited, but examples include particles of the above-mentioned colorants, inorganic particles such as silica particles and particles of the above-mentioned metals, and organic particles such as resin particles. Silica particles are preferable as inorganic particles. The particles may also include the above-mentioned conductive particles other than carbon black. The content of particles in the antigloss layer is not particularly limited, but is preferably from 5% to 50% by mass, and more preferably from 10% to 40% by mass.

[0031] The thickness of the antigloss layer is not particularly limited, but may be, for example, from 1 μm to 10 μm, or from 1 μm to 7 μm.

[0032] As described above, the substrate may have multiple layers. For example, Fig. 2 is a cross-sectional view of a light-shielding film 100 according to one embodiment of the present disclosure. In Fig. 2, the substrate having light-shielding properties includes a base layer 103 and a light-shielding layer 104 disposed on top of the base layer 103. The light-shielding film 100 includes a substrate having light-shielding properties and an anti-gloss layer 102 disposed on top of the substrate. In Fig. 2, a first light-shielding layer and a second light-shielding layer are laminated on both sides of the base layer 103, but a light-shielding layer may be laminated on only one side of the base layer 103.

[0033] The material of the base layer is not particularly limited, but preferably contains a resin. That is, the base layer is preferably a resin layer. The resins described in the column for substrate can be used as the resin. When the base layer contains a resin, the content of the resin in the base layer is not particularly limited, but is preferably 80% by mass or more and 100% by mass or less, and more preferably 90% by mass or more and 100% by mass or less. The base layer may contain other materials, and may contain various additives such as antioxidants, ultraviolet absorbers, heat stabilizers, plasticizers, lubricants, and flame retardants. The thickness of the base layer is not particularly limited, but may be, for example, 1 μm or more and 10 μm or less, or 1 μm or more and 7 μm or less.

[0034] The material of the light-shielding layer is not particularly limited, but preferably contains a binder resin and a colorant. As the binder resin, the binder resins described in the section on antigloss layer can be used. Furthermore, as the colorant, the colorants described in the section on substrate and antigloss layer can be used. From the viewpoint of adjusting the surface resistance value of the substrate, conductive particles such as conductive carbon black are preferred, and conductive carbon black is more preferred. The light-shielding layer may contain the above-mentioned conductive particles other than conductive carbon black.

[0035] From the viewpoint of improving the compatibility between the substrate and the antigloss layer, when the light-shielding layer and the antigloss layer contain a binder resin, it is preferable that the binder resin contained in the light-shielding layer and the binder resin contained in the antigloss layer are the same type. For example, it is preferable that the binder resin contained in the light-shielding layer is a urethane acrylic resin, and the binder resin contained in the antigloss layer is also a urethane acrylic resin. It is more preferable that the binder resin contained in the light-shielding layer and the binder resin contained in the antigloss layer are the same.

[0036] From the viewpoint of improving the compatibility between the substrate and the antigloss layer, when the light-shielding layer and the antigloss layer contain colorants, it is preferable that the colorant contained in the light-shielding layer and the colorant contained in the antigloss layer are the same type. For example, it is preferable that the colorant contained in the light-shielding layer is carbon black, and the colorant contained in the antigloss layer is also carbon black. It is also more preferable that the colorant contained in the light-shielding layer and the colorant contained in the antigloss layer are the same.

[0037] When the light-shielding layer contains a binder resin, the content of the binder resin in the light-shielding layer is not particularly limited, but is preferably 50% by mass or more and 100% by mass or less, and more preferably 60% by mass or less. It is more preferable that the content is not less than 90% by mass. When the light-shielding layer contains carbon black, the content of carbon black in the light-shielding layer is not particularly limited, but is preferably greater than 0% by mass and less than 50% by mass, more preferably 10% by mass or more and 40% by mass or less, and even more preferably 15% by mass or more and 40% by mass or less. The thickness of the light-shielding layer is not particularly limited, but may be, for example, from 1 μm to 10 μm, or from 1 μm to 5 μm.

[0038] As described above, the optical density of the light-shielding film at a wavelength of 380 nm or more and 780 nm or less is 4.0 or more. The optical density is preferably 5.0 or more, and more preferably 6.0 or more. Within the above range, the light-shielding film tends to have excellent light-shielding properties. The upper limit is not particularly limited, but may be 4.0 or more and 10.0 or less, 5.0 or more and 10.0 or less, or 6.0 or more and 10.0 or less. The optical density value can be adjusted by changing the type and content of the material used in the light-shielding substrate and the antigloss layer. Specifically, by providing a light-shielding substrate and an antigloss layer in a light-shielding film, the optical density value is more likely to fall within the above range. Furthermore, when the light-shielding substrate contains a colorant, the optical density value can be increased by increasing the content of the colorant in the substrate, and the optical density value can be decreased by decreasing the content of the colorant. Similarly, when the antigloss layer contains a colorant, the optical density value can be increased by increasing the content of the colorant in the antigloss layer, and the optical density value can be decreased by decreasing the content of the colorant. The method for measuring the optical density value will be described later.

[0039] As described above, the glossiness of at least one surface of the antigloss layer at an incident angle of 60 degrees is 0.0% or more and 10.0% or less. The glossiness is preferably 0.0% or more and 5.0% or less, and more preferably 0.0% or more and 1.0% or less. Within the above range, the antigloss properties of the antigloss layer are more excellent. This makes it easier to reduce the reflectance of the light-shielding film. The gloss level can be adjusted by, for example, adjusting the type and content of the particles that can be contained in the antigloss layer. Specifically, when inorganic particles such as silica particles are used as the particles, the gloss level can be easily adjusted to the above range. The method for measuring the glossiness will be described later.

[0040] As mentioned above, the surface resistance of the light-shielding film is 1.0 x 10 5 The surface resistance of the light-shielding film is 5.0×10 4 It is preferable that the resistance is Ω / □ or less, and 1.0×10 4 The lower limit is preferably 1.0×10 Ω / □ or less. -3 Ω / □ or more, and 1.0×10 -2 Ω / □ or more, and 1.0×10 -1That is, the surface resistance of the light-shielding film may be, for example, 1.0×10 -3 ~1.0×10 5 Ω / □, 1.0×10 -2 ~5.0×10 4 Ω / □, 1.0×10 -1 ~1.0×10 4 Within the above range, the antistatic function of the light-shielding film is more excellent, which makes it easier to obtain a light-shielding film with excellent workability. The surface resistance of the light-shielding film can be adjusted by changing the surface resistance of the substrate using the method described in the description of the substrate. In addition, by improving the compatibility between the substrate and the antigloss layer, the surface resistance of the light-shielding film tends to fall within the above range. The method for measuring the surface resistance of the light-shielding film will be described later.

[0041] The thickness of the light-shielding film is not particularly limited, but may be, for example, 35 μm or less, or 30 μm or less. If the thickness of the light-shielding film is in this range, the workability of the light-shielding film is likely to be reduced, but the light-shielding film of the present disclosure can provide excellent workability. The lower limit of the thickness of the light-shielding film is not particularly limited, but may be 3 μm or more and 35 μm or less, 3 μm or more and 30 μm or less, or 8 μm or more and 20 μm or less.

[0042] <Lens unit> The lens unit includes the light-shielding film of the present disclosure. For example, the lens unit includes a light-shielding film and a lens. Fig. 3 is an exploded view of lens unit 40. In Fig. 3, lens unit 40 includes a plurality of light-blocking members F1 to F6, a plurality of optical members (lenses L1 to L6 in this example), and a housing (lens barrel) 41 that houses the light-blocking members F1 to F6 and the optical members. In Fig. 3, light-blocking members F1 to F6 are arranged between adjacent optical members so as to surround the optical axis R of the optical members. There are no limitations on the number of light-blocking members and the number of optical members included in lens unit 40.

[0043] The light-shielding members F1 to F6 have the same cross-sectional structure as the light-shielding film. That is, the light-shielding members F1 to F6 include a substrate having light-shielding properties and an antigloss layer disposed on the substrate. The substrate having light-shielding properties may be one described above in the description of the substrate, and the antigloss layer may be one described above in the description of the antigloss layer. The lens unit of the present disclosure can impart anti-glare properties to the light-shielding members F1 to F6, which scatter external incident light with the anti-gloss layer. Furthermore, reflection of incident light entering the anti-gloss layer can be suppressed. This effectively reduces the brightness of the surface of the anti-gloss layer. As described above, the antigloss layer is more transparent than the substrate. Therefore, the light-blocking properties of the substrate can be displayed to the outside through the antigloss layer. As a result, light-blocking members F1 to F6 with low brightness and excellent light-blocking properties can be realized.

[0044] Hereinafter, methods for measuring the physical properties of the light-shielding film of the present disclosure will be described.

[0045] <Method for measuring the optical density of light-shielding film> Using a transmission densitometer (Xrite's "341C type (transmission densitometer)"), the optical density of the light-shielding film is measured at wavelengths of 380 nm or more and 780 nm or less.

[0046] <Method for measuring glossiness of anti-gloss layer> The gloss of the surface of the antigloss layer is measured at an incident angle of 60 degrees using a gloss meter (manufactured by TQC, "RDK-12 / KT-GL0030 type").

[0047] <Method for measuring surface resistance> The surface of the light-shielding substrate and the surface of the anti-gloss layer are measured using a Loresta (Mitsubishi Chemical Corporation, Model MCP-T610) to obtain the surface resistance value. If the measurement limit of the Loresta is exceeded, the surface resistance value is obtained by measuring using an ultra-high resistance / microcurrent meter (Advantest Corporation, Model R8340). Here, the result of measuring the surface of the anti-gloss layer is taken as the surface resistance value of the light-shielding film.

[0048] The configurations and combinations thereof in each embodiment are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible as appropriate within the scope of the gist of the present disclosure. The present disclosure is not limited by the embodiments, but is limited only by the scope of the claims. [Example]

[0049] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to the aspects of the following examples.

[0050] [Example 1] A 6 μm-thick PET film (PET film manufactured by Toray Industries, Inc.) was used as the base layer. 32 parts by weight of a urethane acrylic resin (KDC-01 base resin manufactured by Koshin Chemical Co., Ltd.) as a binder resin was mixed with 3 parts by weight of an ink containing carbon black and urethane acrylic resin (E039 PET AKSB 92T manufactured by Toyochem Co., Ltd.), 55 parts by weight of a carbon black dispersion (MHI Black #273 manufactured by Mikuni Shikiso Co., Ltd.), and 10 parts by weight of a curing agent (Takenate A-3 manufactured by Mitsubishi Chemical Corporation) to obtain a coating solution. The resulting coating solution was applied to both sides of the base layer and thermally cured to form a pair of light-shielding layers, each 1.5 μm thick after drying, to obtain a light-shielding substrate. Furthermore, 54 parts by weight of a urethane acrylic resin (KDC-01 base resin, manufactured by Koshin Chemical Co., Ltd.) as a binder resin was mixed with 6 parts by weight of an ink containing carbon black and urethane acrylic resin (E039 PET AKSB 92T, manufactured by Toyochem Co., Ltd.), 12.5 parts by weight of a curing agent (Takenate A-3, manufactured by Mitsubishi Chemical Corporation), 7.5 parts by weight of silica particles (Silo Hobic 100, manufactured by Fuji Silysia Co., Ltd.), 15 parts by weight of a carbon black dispersion (MHI Black #273, manufactured by Mikuni Color Co., Ltd.), and the remainder was mixed with a solvent (methyl ethyl ketone) to obtain a coating solution. The resulting coating solution was applied to both sides of a light-shielding substrate and thermally cured to form a pair of anti-gloss layers, each 3.5 μm thick after drying, to obtain a light-shielding film. The resulting light-shielding film was measured using the methods described above. The measurement results are shown in Table 1.

[0051] [Example 2] A light-shielding film was obtained in the same manner as in Example 1, except that the amount of carbon black dispersion ("MHI Black #273" manufactured by Mikuni Shikiso Co., Ltd.) used when forming the light-shielding layer was changed to 30 parts by mass. The obtained light-shielding film was measured in the same manner as in Example 1. The measurement results are shown in Table 1.

[0052] [Comparative Example 1] A light-shielding film was obtained in the same manner as in Example 1, except that the amount of urethane acrylic resin as the binder resin when forming the light-shielding layer was 38 parts by mass, the amount of ink was 52 parts by mass, and no carbon black dispersion was used. The obtained light-shielding film was measured in the same manner as in Example 1. The measurement results are shown in Table 1.

[0053] Comparative Example 2 A light-shielding film was obtained in the same manner as in Example 1, except that a 12 μm thick black film containing carbon black (manufactured by Nanya Plastics Co., Ltd.) was used as the light-shielding substrate and the thickness of each anti-gloss layer after drying was set to 5 μm. The obtained light-shielding film was measured in the same manner as in Example 1. The measurement results are shown in Table 1.

[0054] Comparative Example 3 A light-shielding film was obtained in the same manner as in Example 1, except that an antigloss layer was not formed. That is, a substrate having light-shielding properties was obtained in the same manner as in Example 1, and the obtained substrate was used as a light-shielding film. The obtained light-shielding film was measured in the same manner as in Example 1. The measurement results are shown in Table 1.

[0055] Comparative Example 4 A light-shielding film was obtained in the same manner as in Example 1, except that an 8.5 μm thick aluminum foil (Nippaku Foil manufactured by Mitsubishi Aluminum Co., Ltd.) was used as the light-shielding substrate and the thickness of the antigloss layer after drying was 2.25 μm. The obtained light-shielding film was measured in the same manner as in Example 1. The measurement results are shown in Table 1.

[0056] Comparative Example 5 A light-shielding film was obtained in the same manner as in Example 1, except that the thickness of the base layer was 4.5 μm, the materials used to form the light-shielding layer were a urethane binder resin ("Byron 40SS" manufactured by Toyobo Co., Ltd.) and a carbon black dispersion ("MHI Black #273" manufactured by Mikuni Shikiso Co., Ltd.), the mass ratio of carbon black to the light-shielding layer was 12 mass%, the materials used to form the anti-gloss layer were a thermosetting binder resin ("KDC-03" manufactured by Koshin Chemical Co., Ltd.), silica particles ("Sylysia 420" manufactured by Fuji Silysia Co., Ltd.), and a carbon black dispersion ("MHI Black #273" manufactured by Mikuni Shikiso Co., Ltd.), the mass ratio of carbon black to the anti-gloss layer was 4 mass%, and the thickness of the anti-gloss layer was 4.0 μm. The obtained light-shielding film was measured using the methods described above. The measurement results are shown in Table 1. [Table 1] In the table, the OD value indicates the optical density value.

[0057] In Examples 1 and 2, the surface resistance of the light-shielding film was 1.0 × 10 5 It became less than Ω / □. On the other hand, in Comparative Examples 1, 2, 4, and 5, the surface resistance of the light-shielding film was 1.0 × 10 5 The anti-static properties were insufficient, and workability was poor. When the light-shielding film did not have an anti-gloss layer as in Comparative Example 3, the 60-degree gloss was very high and a low reflectance could not be achieved. [Industrial Applicability]

[0058] According to the present disclosure, it is possible to provide a light-shielding film that achieves both low reflectance and workability. Furthermore, the light-shielding film of the present disclosure can be used in a lens unit. [Explanation of symbols]

[0059] 40 lens unit, 41 housing, 100 light-shielding film, 101 substrate having light-shielding properties, 102 anti-gloss layer, 103 base layer, 104 light-shielding layer, F1 to F6 light-shielding members, L1 to L6 lenses, R optical axis

Claims

1. A light-shielding film comprising a substrate having light-shielding properties and an anti-gloss layer disposed on the substrate, the anti-gloss layer is more transparent than the substrate; The optical density of the light-shielding film is 4.0 or more at a wavelength of 380 nm or more and 780 nm or less, the glossiness of at least one surface of the antigloss layer at an incident angle of 60 degrees is 0.0% or more and 10.0% or less; The surface resistance of the light-shielding film is 1.0×10 ５ A light-blocking film having a resistance of Ω / □ or less.

2. The light-shielding film according to claim 1 , wherein the substrate has antistatic properties.

3. The light-shielding film according to claim 1 , wherein the substrate contains carbon black.

4. 2. The light-shielding film according to claim 1, wherein the antigloss layer contains carbon black, and the content of the carbon black in the antigloss layer is greater than 0% by mass and not more than 5% by mass.

5. The light-shielding film according to claim 1 , wherein the antigloss layer contains a binder resin and particles dispersed within the binder resin.

6. The light-shielding film according to claim 1, wherein the thickness of the light-shielding film is 35 μm or less.

7. The light-shielding film according to claim 1, wherein the thickness of the substrate is 2 μm or more and 30 μm or less.

8. The light-shielding film according to claim 1, wherein the thickness of the antigloss layer is from 1 μm to 7 μm.

9. The light-shielding film according to any one of claims 1 to 8, which is a shutter of an optical component, a diaphragm member, or a gap adjustment member disposed between a plurality of lenses.

10. A lens unit comprising the light-shielding film according to claim 9.

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