Image display device

Abstract

To provide an image display device which offers superior contrast between black and white and suppresses reduction in white luminance when displaying images in monochrome.SOLUTION: An image display device of the present invention comprises an image display element having a display area and non-display area, and an optical member covering the display area, the optical member exhibiting a refractive index of 1.55 or greater, containing a visible light absorbing material α, and having an internal absorbance A2 in a range of 0.0004 to 0.03 as derived from a test X2 and a parameter X2 in a range of 30 to 3000 m-1.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an image display device. [Background technology]

[0002] Conventionally, touch sensors that detect a so-called touch operation, in which a finger or a stylus pen is brought into contact with or in proximity to a screen, have been used in various electronic devices, including portable information devices such as tablet computers and smartphones. Such touch sensors are usually formed on the surface of a substrate and have detection electrodes that detect the touch operation.

[0003] For example, Patent Document 1 discloses a conductive film having a substrate and conductor wiring provided on at least one surface of the substrate, where the conductor wiring has a metal layer and a visibility suppression layer, and the visibility suppression layer has a transparent layer, a chromium-containing layer, and a transparent layer in this order, as well as a touch panel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-182285 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been an increasing use of image display devices, particularly image display devices having an image display element and a touch sensor, that exhibit high contrast. For example, when performing black-and-white display, in which white and black are simultaneously displayed, there is a demand for an image display device that exhibits excellent contrast between the black and white displays while maintaining the luminance of the white display area. In particular, the present inventors have studied the display performance of an image display device having a touch sensor, with reference to the technology disclosed in Patent Document 1, and have found that, compared to an image display device without a touch sensor, when performing black-and-white display, in which white and black are simultaneously displayed, the luminance of the black display area adjacent to the white display area tends to increase, resulting in a decrease in contrast.

[0006] In view of the above-described circumstances, an object of the present invention is to provide an image display device that, when displaying black and white, has excellent contrast between the black display and the white display and is excellent in the performance of suppressing a decrease in the brightness of the white display. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems and have completed the present invention. That is, they have found that the above problems can be solved by the following configuration. [A1] An image display device having an image display element having a display area and a non-display area, and an optical member covering the display area, wherein the refractive index of the optical member is 1.55 or more, the optical member contains a visible light absorber α, and the optical member has an internal absorbance A2 calculated by a test X2 described later of 0.0004 to 0.03, and a parameter X2 of 30 to 3000 m -1 An image display device. [A2] The image display device according to [A1], wherein the optical member has a thickness D2 of 20 to 200 μm. [A3] The image display device according to [A1] or [A2], wherein the visible light absorbing material α is a black pigment, and the content of the black pigment is 10 to 500 ppm by mass with respect to the total mass of the optical member. [A4] The touch sensor is further provided between the image display element and the optical member, and the touch sensor has a substrate and a detection electrode provided on at least one surface side of the substrate, the substrate includes a visible light absorbing material β, and the substrate has an internal absorbance A1 calculated by a test X described later of 0.0004 to 0.03 and a parameter X of 30 to 3000 m -1 The image display device according to any one of [A1] to [A3], wherein: [A5] The image display device according to [A4], wherein the thickness D1 of the substrate is 110 μm or less. [A6] The image display device according to [A4] or [A5], wherein the visible light absorbing material β is a black pigment, and the content of the black pigment is 10 to 500 ppm by mass with respect to the total mass of the base material. [A7] The image display device according to any one of [A4] to [A6], further comprising an adhesive layer, in which the image display element, the adhesive layer, and the touch sensor are arranged in this order. [A8] The image display device according to any one of [A1] to [A7], wherein the image display element is an organic electroluminescence display element.

[0008] The present inventors have also discovered that, by using the following configuration, it is possible to provide a touch sensor that, when applied to an image display device to display black and white, has excellent contrast between black and white displays and has excellent performance in suppressing a decrease in the brightness of the white display, and an image display device having such a touch sensor. [B1] A touch sensor including a substrate and a detection electrode disposed on at least one surface side of the substrate, wherein the substrate includes a visible light absorbing material β, and the substrate has an internal absorbance A1 calculated by a test X described later of 0.03 or less, and a parameter X of 30 m -1 That's it, the touch sensor. [B2] The touch sensor according to [B1], wherein the thickness D1 of the substrate is 110 μm or less. [B3] The touch sensor according to [B1] or [B2], wherein the visible light absorbing material β is a black pigment, and the content of the black pigment is 10 to 500 ppm by mass with respect to the total mass of the base material. [B4] The touch sensor according to any one of [B1] to [B3], wherein the thickness D1 of the substrate is 110 μm or less, the visible light absorbing material β is a black pigment, and the content of the black pigment is 10 to 500 ppm by mass with respect to the total mass of the substrate. [B5] A touch panel having the touch sensor according to any one of [B1] to [B4]. [B6] An image display device comprising an image display element and the touch sensor according to any one of [B1] to [B4]. [B7] The image display device according to [B6], further comprising an adhesive layer, in which the image display element, the adhesive layer, and the touch sensor are arranged in this order. [B8] The image display device according to [B6] or [B7], wherein the image display element is an organic electroluminescence display element. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an image display device that has excellent contrast between black and white display when black and white display is performed, and also has excellent performance in suppressing a decrease in white display luminance. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a plan view schematically illustrating an example of a touch sensor. [Figure 2] FIG. 1 is a cross-sectional view schematically illustrating an example of an image display device. [Figure 3] FIG. 2 is a plan view illustrating an example of a detection electrode included in the touch sensor. [Figure 4] 1 is a cross-sectional view illustrating an example of an image display device according to an embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view showing another example of an image display device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, the touch sensor and the image display device of the present invention will be described in detail with reference to the drawings. The following description of the components is based on a typical embodiment of the present invention, and the present invention is not limited to such an embodiment. In addition, the drawings are provided for illustrative purposes only, and the scale of each component may be changed from the actual scale to facilitate visibility or explanation. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In this specification, when two or more types of a component are present, the "content" of that component means the total content of those two or more components. Regarding angles, "perpendicular" or "perpendicular" means a range of 90°±5°, and "parallel" means a range of 0°±5°. Similarly, unless otherwise specified, angles expressed as specific numerical values ​​mean that the difference from the exact angle is within 5 degrees. The difference between the above-mentioned perpendicular, perpendicular, and parallel angles and the above-mentioned angles and the exact angle is preferably within 4 degrees, and more preferably within 3 degrees. In this specification, "stacking" means arranging two or more members overlapping in the thickness direction, and "laminate" means a structure in which two or more members are arranged in the thickness direction. In addition, there are no restrictions on the manufacturing method for either "stacking" or "laminate."

[0012] The term "polymer" or "polymer" refers to a compound having a weight-average molecular weight of 2000 or more. Here, the weight-average molecular weight is defined as a polystyrene-equivalent value measured using gel permeation chromatography (GPC) under the following conditions: Equipment: Tosoh Corporation HLC-8320GPC Column: Tosoh TSK-GEL G3000PWXL Column temperature: 35℃ ·Flow rate: 0.5mL / min Calibration curve: Poly sodium acrylate standard manufactured by Sowa Scientific Co., Ltd. Eluent: A mixture of sodium dihydrogen phosphate dodecahydrate / disodium hydrogen phosphate dihydrate (34.5g / 46.2g) diluted to 5000g with purified water.

[0013] The term "main surface" refers to the surface with the largest area in a film-, sheet- or plate-like member. "Visible light" means light in the wavelength range of 380 to 780 nm. The term "transparent" means that the light transmittance in the visible light wavelength range is 40% or more, preferably 60% or more, more preferably 80% or more, and even more preferably 90% or more. The light transmittance is measured using a known transmittance measuring device in accordance with "Plastics - Determination of total light transmittance and total light reflectance" as defined in JIS K 7375:2008.

[0014] In this specification, the term "acrylic resin" is used to mean either or both of a polymer and a copolymer containing units derived from at least one monomer selected from the group consisting of acrylate monomers and methacrylate monomers.

[0015] [First embodiment: touch sensor] A touch sensor according to a first embodiment of the present invention includes a substrate and a detection electrode disposed on at least one surface side of the substrate. The touch sensor of this embodiment will be described in detail below with reference to the drawings.

[0016] FIG. 1 is a plan view schematically illustrating an example of the configuration of a touch sensor according to the present embodiment. The touch sensor 10 includes a substrate 1, a detection electrode 11 arranged on one surface 1a of the substrate 1, and a detection electrode 21 arranged on the other surface 1b of the substrate 1. In the figure, the multiple detection electrodes 11 all extend along the Y direction on the surface 1a of the substrate 1. The multiple detection electrodes 11 are also arranged at intervals from one another in the X direction, which is perpendicular to the Y direction. The surface 1a of the substrate 1 is further provided with multiple electrode connection terminals 12 formed at one end of each of the multiple detection electrodes 11, multiple peripheral wirings 13 electrically connected to each of the multiple electrode connection terminals 12, and multiple external connection terminals 14 electrically connected to each of the multiple peripheral wirings 13. The multiple external connection terminals 14 are used for electrical connection to external devices (not shown). One end of each of the multiple peripheral wirings 13 is connected to a corresponding electrode connection terminal 12, and the other end is connected to the external connection terminal 14. Each of the plurality of detection electrodes 21 extends along the X direction on the surface 1b of the substrate 1. The plurality of detection electrodes 21 are also arranged at intervals in the Y direction. The surface 1b of the substrate 1 is further provided with a plurality of electrode connection terminals 22 electrically connected to one ends of the plurality of detection electrodes 21, a plurality of peripheral wirings 23 electrically connected to the plurality of electrode connection terminals 22, and a plurality of external connection terminals 24 electrically connected to the plurality of peripheral wirings 23. The plurality of external connection terminals 24 are used for electrical connection to external devices (not shown). One end of each of the plurality of peripheral wirings 23 is connected to a corresponding electrode connection terminal 22, and the other end is connected to the external connection terminal 24.

[0017] As will be described later, the detection electrodes 11 and 21 function as sensor electrodes for detecting a so-called touch operation, and are made up of a plurality of thin conductive wires. 1, the detection region R1 is a region surrounding the detection electrodes 11 and 21 arranged on the surface of the substrate 1. The peripheral region R2 is a region outside (on the periphery of) the detection region R1, and peripheral wiring 13 is arranged in the peripheral region R2.

[0018] FIG. 2 is a schematic cross-sectional view showing an example of an image display device having a touch sensor according to this embodiment. The image display device 100 shown in FIG. 2 includes an image display element 30, a touch sensor 10 of this embodiment, and a protective layer 40 arranged in this order in the stacking direction. In the image display device 100, an image (not shown) displayed on the display surface 30a of the image display element 30 is visible through the touch sensor 10 and the protective layer 40. The surface 40a of the protective layer 40 opposite to the touch sensor 10 is the touch surface of the image display device 100 and serves as the operation surface.

[0019] As described above, the touch sensor 10 includes the substrate 1, the detection electrode 11 arranged on one surface 1a of the substrate 1, and the detection electrode 21 arranged on the other surface 1b of the substrate 1. 2 has a multilayer structure made up of a support 2 and undercoat layers 3 disposed on both surfaces of the support 2. The touch sensor 10 also has an adhesive layer 4 disposed on one surface 1a of the base material 1 so as to cover the detection electrode 11, and an adhesive layer 4 disposed on the other surface 1b of the base material 1 so as to cover the detection electrode 21.

[0020] The touch sensor of this embodiment is a touch sensor including a substrate and a detection electrode arranged on at least one surface side of the substrate, wherein the substrate includes a visible light absorbing material β, and the internal absorbance A1 calculated by a test X described later is 0.03 or less, and the parameter X is 30m -1 The present invention is characterized in that:

[0021] The mechanism by which the touch sensor of this embodiment, when applied to an image display device to display black and white, exhibits excellent contrast between black and white displays, as well as excellent performance in suppressing a decrease in white display brightness, is not entirely clear, but the inventors speculate as follows. The inventors have thoroughly investigated the above-mentioned problem of reduced contrast in an image display device having a touch sensor laminated on an image display element, and first found that an increase in luminance in black display is observed even in a dark room where there is no external light, and therefore the increase in luminance in black display and the decrease in contrast are not caused by reflection of external light.Further investigation led them to deduce that the above-mentioned cause may be that part of the light emitted from the white display section is transmitted or propagated through the inside of the substrate laminated on the image display element by scattering or reflection, etc., toward the black display section adjacent to the white display section, and reaches the position where the viewer views it, resulting in an increase in luminance in black display. Based on this assumed mechanism, we found that by adding visible light absorbing material β to the substrate that constitutes the touch sensor and reducing the light that transmits or propagates inside the substrate, it is possible to significantly suppress the increase in brightness of a black display displayed adjacent to a white display, thereby improving the contrast between the black display and the white display. Furthermore, in the touch sensor of this embodiment, the internal absorbance A1 of the substrate measured by a predetermined test method and the parameter X are each set within a predetermined range. This suppresses the reduction in light emitted from the image display element in the white display area and improves contrast without substantially impairing the brightness of the white display, so it is presumed that the touch sensor can achieve display characteristics that are comparable to those of an image display device without a touch sensor.

[0022] In this specification, the expression "the effects of the present invention are excellent" means that when the image display device displays black and white, at least one of the contrast between the black display and the white display and the performance of suppressing a decrease in the brightness of the white display is excellent.

[0023] Hereinafter, each member included in the touch sensor or image display device of this embodiment will be described in detail. The touch sensor of this embodiment is not limited to the embodiment shown in Figures 1 and 2. For example, the detection electrode may be disposed on only one surface of the substrate. The substrate may have a multilayer structure having a support and an undercoat layer formed on only one surface of the support, or may be composed of the substrate alone without the undercoat layer.

[0024] <Base material> The substrate is a member having a function of supporting the detection electrode. The substrate is not particularly limited, but a resin substrate is preferred. Examples of materials that can be used to form the substrate include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, triacetyl cellulose, polystyrene, polyolefins, polyurethane resins, polyvinyl chloride, polyimide resins, and polyamide resins. The substrate may be a single layer of the above resin, or a composite film composed of a plurality of resin layers.

[0025] As the substrate, a film made of polyester resin is preferred because it is easy to manufacture. Examples of polyester resins include linear saturated polyesters synthesized from an aromatic dibasic acid or its ester-forming derivative and a diol or its ester-forming derivative. Specific examples of linear saturated polyesters include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly(1,4-cyclohexylene dimethylene terephthalate), and polyethylene-2,6-naphthalate. Among these, polyethylene terephthalate, polyethylene-2,6-naphthalate, and poly(1,4-cyclohexylene dimethylene terephthalate) are preferred in terms of the balance between mechanical properties and cost. The polyester resin may be a homopolymer or a copolymer, and may also be a mixture of a polyester resin and a small amount of another type of resin, such as polyimide.

[0026] The content of the resin contained in the substrate is preferably 75% by mass or more, and more preferably 90% by mass or more and less than 100% by mass, based on the total mass of the substrate.

[0027] (Visible light absorber β) The visible light absorber β contained in the substrate may be any substance having absorption wavelength characteristics that absorb visible light (wavelength 380 to 780 nm), and for example, a substance having a maximum absorption wavelength of 380 to 780 nm can be used.

[0028] Examples of the visible light absorber β include dyes and pigments, preferably pigments, and more preferably black pigments. Examples of materials constituting the visible light absorber β include carbon materials, organic materials, inorganic oxides, inorganic nitrides, and inorganic oxynitrides. Examples of black pigments include carbon black, graphite, aniline black, cyanine black, black iron oxide, chromium oxide, manganese oxide, titanium nitride, and titanium oxynitride, with titanium nitride or titanium oxynitride being preferred.

[0029] As the pigment, a particulate pigment can be used, and the shape thereof is not particularly limited. To prevent the display function of the display from being impaired by light scattering, the average primary particle size of the pigment is preferably 500 nm or less, more preferably 200 nm or less, and even more preferably 100 nm or less. There is no particular lower limit, but a value of 10 nm or more is preferred. The average primary particle size of a pigment is obtained by measuring the equivalent sphere diameter of 100 objects and calculating the arithmetic mean. The equivalent sphere diameter refers to the diameter of a spherical particle with the same volume. However, when using commercially available pigments, the catalog value is used as the average primary particle size.

[0030] The visible light absorbing material β may be used alone or in combination of two or more. The content of the visible light absorber β (preferably a black pigment) is preferably 5,000 ppm by mass or less, more preferably 500 ppm by mass or less, and even more preferably 100 ppm by mass or less, relative to the total mass of the substrate, from the viewpoint of preventing impairment of the display function due to light scattering. The lower limit is not particularly limited as long as the internal absorbance is at least a predetermined value, but is preferably 5 ppm by mass or more, more preferably 10 ppm by mass or more, relative to the total mass of the substrate.

[0031] As a method for producing a substrate containing the visible light absorbent material β, various known methods can be applied. A representative production method includes a method in which a resin containing the visible light absorbent material β is produced and then a substrate is produced using the resin. Examples of methods for producing a resin containing the visible light absorbing material β include the following methods: Note that all of the following methods are examples in which the substrate is a resin substrate containing a polyester resin. (A) A method in which the visible light absorber β is added before the completion of the transesterification reaction or the esterification reaction during the synthesis of the polyester resin, or before the start of the polycondensation reaction. (B) A method in which a visible light absorber β is added to a synthesized polyester resin and the resulting mixture is melt-kneaded. (C) A method in which a master pellet (also referred to as a master batch (MB)) to which a large amount of visible light absorbent β has been added is produced by the above method (A) or (B), and then the MB and a polyester resin not containing the visible light absorbent β are kneaded to produce a polyester resin containing a predetermined amount of the visible light absorbent β. (D) A method in which the MB in (C) above is used as is.

[0032] A preferred method for producing a resin containing the visible light absorbent β is the masterbatch method (MB method: (C) above) in which a polyester resin and a large amount of the visible light absorbent β are mixed in an extruder in advance to produce MB. In the MB method, a method can also be adopted in which a polyester resin that has not been dried in advance and a visible light absorber β are put into an extruder and MBs are produced while removing moisture, air, etc. In the MB method, it is preferable to produce MBs using a polyester resin that has been dried even slightly in advance, since this prevents an increase in the acid value of the polyester resin. In this case, examples include a method of extruding while degassing, and a method of extruding a sufficiently dried polyester resin without degassing.

[0033] In the MB method, the polyester resin used to prepare MB is preferably dried to reduce its moisture content in advance. Drying conditions include a drying temperature of preferably 100 to 200°C, more preferably 120 to 180°C, and a drying time of preferably 1 hour or more, more preferably 3 hours or more, and even more preferably 6 hours or more. This allows the polyester resin to be sufficiently dried so that its moisture content is preferably 50 mass ppm or less, more preferably 30 mass ppm or less. The method for premixing the polyester resin and the visible light absorber β is not particularly limited, and may be a batch process mixing method or a mixing method using a single-screw or twin-screw or more kneading extruder. When preparing MB while degassing, it is preferable to use a premixer equipped with one or more, preferably two or more, degassing ports, melt the polyester resin at a temperature of 250 to 300°C, preferably 270 to 280°C, and maintain a reduced pressure in the kneader by performing continuous suction degassing at 0.05 MPa or more, more preferably 0.1 MPa or more.

[0034] In addition to the above-mentioned resin and visible light absorber β, the substrate may further contain additives such as a light stabilizer, an antioxidant, an ultraviolet absorber, a flame retardant, a lubricant (fine particles), a nucleating agent (crystallization agent), and a crystallization inhibitor.

[0035] (undercoat layer) The substrate may have an undercoat layer on at least one of its two main surfaces, i.e., the substrate may have a multi-layer structure consisting of a support and an undercoat layer. When the substrate has a multilayer structure consisting of a support and an undercoat layer, the undercoat layer is preferably disposed on the surface of the substrate on which the detection electrode is provided. The undercoat layer may be disposed on both sides of the support. As the support forming a multilayer structure with the undercoat layer, the materials listed above as the base material can be used.

[0036] The undercoat layer may contain a resin (binder resin). The resin functions as a binder for the undercoat layer. The resin contained in the undercoat layer may be used alone or in combination of two or more. The type of resin is not particularly limited, and known resins can be used. Examples of resins include polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, and polythiolpolyene resins, with acrylic resins being preferred. The weight average molecular weight of the resin is, for example, 500 to 500,000, and preferably 1,000 to 100,000. When the undercoat layer contains a resin, the content of the resin is, for example, 80 to 99.5% by mass relative to the total mass of the undercoat layer.

[0037] The undercoat layer may further contain a surfactant. The type of surfactant is not particularly limited, and known surfactants can be used, and at least one surfactant selected from silicone surfactants and fluorine surfactants is preferred. The surfactant is also preferably an oligomer or polymer. When the undercoat layer contains a surfactant, the content of the surfactant is, for example, 0.01 to 5% by mass relative to the total mass of the undercoat layer.

[0038] The undercoat layer may further contain inorganic particles other than the visible light absorbing material β. The type of inorganic particles is not particularly limited, and examples thereof include silica, zirconium oxide, and aluminum oxide. The particle size of the inorganic particles is not particularly limited, but is preferably 5 to 100 nm, more preferably 10 to 80 nm. When the undercoat layer contains inorganic particles, the content of the inorganic particles is, for example, 0.01 to 10% by mass relative to the total mass of the undercoat layer.

[0039] The thickness of the undercoat layer is not particularly limited, but is preferably 0.01 to 1 μm, and more preferably 0.05 to 0.3 μm.

[0040] The method for forming the undercoat layer is not particularly limited, and examples thereof include a method in which an undercoat layer is formed on the main surface of the substrate by contacting the substrate with a composition for forming an undercoat layer containing the components contained in the undercoat layer. Examples of methods for contacting the substrate with the composition for forming an undercoat layer include a method of applying the composition for forming an undercoat layer to the surface of the substrate and a method of immersing the substrate in the composition for forming an undercoat layer. If necessary, after contacting the composition for forming an undercoat layer with the substrate, a drying treatment may be performed to remove the solvent contained in the composition for forming an undercoat layer. Alternatively, a primer layer may be formed on the surface of a temporary support other than the substrate in the same manner as described above, and then the surface of the primer layer formed on the temporary support opposite the temporary support may be bonded to one surface of the substrate, and the temporary support may be peeled off at the interface between the temporary support and the primer layer, thereby placing the primer layer on the surface of the substrate.

[0041] The composition for forming the undercoat layer may contain other components in addition to the above-mentioned resin, surfactant, and inorganic particles. Examples of other components include a solvent. The type of solvent is not particularly limited, and examples thereof include water and organic solvents. Examples of organic solvents include known organic solvents such as alcohol-based solvents, ether-based solvents, ester-based solvents, ketone-based solvents, halogen-based solvents, and hydrocarbon-based solvents. One type of solvent may be used alone, or two or more types may be mixed and used. The undercoat layer-forming composition may contain a resin precursor (monomer, etc.) instead of the above-mentioned resin. In this case, a composition containing the resin precursor may be brought into contact with a substrate to form an undercoat layer precursor layer, and then treatments such as exposure treatment and heat treatment may be performed to form an undercoat layer containing the above-mentioned resin. When exposure treatment is performed, the undercoat layer-forming composition preferably contains a polymerization initiator. The polymerization initiator is appropriately selected depending on the type of resin precursor.

[0042] In order to improve the adhesion between the substrate and the undercoat layer, it is preferable to form the undercoat layer by an in-line coating method. That is, it is preferable to produce a substrate having an undercoat layer by applying a composition for forming an undercoat layer to at least one main surface of an unstretched film or a film stretched in a first in-plane direction, and then stretching the coated film in a second in-plane direction perpendicular to the first direction.

[0043] (Physical properties of the base material, etc.) The substrate included in the touch sensor of this embodiment has an internal absorbance A1 calculated by the following test X of 0.03 or less, and the parameter X is 30 m -1 That's all. Test X: The visible light reflectance ρ of the support white plate is obtained by the method described in JIS R 3106:2019. Similarly, the visible light reflectance ρ is measured by irradiating a measurement light onto the substrate side of a laminate formed by laminating a support white plate and a substrate by the method described in JIS R 3106:2019. x The obtained visible light reflectance ρ0 and visible light reflectance ρ x The internal absorbance A1 of the substrate is calculated from the following formula (1). The parameter X(m -1 ) is calculated. Equation (1) A1= -log 10 {(ρ x / ρ0) 0.5} Equation (2) X = A1 / D1 The supporting white plate can be a commercially available standard white plate (perfect diffuser plate) for measuring total light spectral reflectance. More specifically, for example, a barium sulfate plate or a Spectralon standard reflector plate can be used.

[0044] Here, if the ratio of the optical intensity of outgoing light to the optical intensity of incident light when visible light is incident on the substrate is defined as the internal transmittance T1 of the substrate, the internal absorbance A1 of the substrate is expressed by the following formula (3). Equation (3) A1= -log 10 (T1) In addition, from the measurement method of test X, the internal transmittance T1 of the substrate and the visible light reflectance ρ of the laminate x , and the visible light reflectance ρ0 of the supporting white plate can be considered to satisfy the relationship of the following formula (4). Equation (4) ρ x = T1×ρ0×T1 The above formula (1) is established from the above formulas (3) and (4). In this way, the visible light reflectance ρ of the laminate can be calculated using formula (1). xThe internal absorbance A1 of the substrate can be calculated from the visible light reflectance ρ0 of the supporting white plate.

[0045] The visible light reflectance ρ of the above supporting white board and the visible light reflectance ρ of the laminate x is obtained by following the measurement and calculation methods for visible light reflectance described in JIS R 3106:2019. A more specific method for carrying out test X will be described in the Examples below. Below, "visible light reflectance ρ0" and "visible light reflectance ρ x " and "reflectance ρ0" and "reflectance ρ x " is also written.

[0046] The internal absorbance A1 of the substrate represents the degree of attenuation of light inside the substrate, and reflection on both main surfaces of the substrate does not affect the internal absorbance A1 or parameter X. It is presumed that by setting the internal absorbance A1 and parameter X within the above ranges, it is possible to suppress an increase in the luminance of black display due to the transmission and propagation of light inside the substrate while maintaining the luminance of white display transmitted along the stacking direction of the touch sensor, thereby improving the contrast between black display and white display.

[0047] The internal absorbance A1 is preferably from 0.0004 to 0.0300, more preferably from 0.0010 to 0.0050, in that the effects of the present invention are more excellent. The internal absorbance A1 can be adjusted by, for example, the type and content of the visible light absorbing material β added to the substrate, the type of resin constituting the substrate, and the thickness D1 of the substrate.

[0048] The parameter X of the substrate is 40 to 3000 m, which is the range from which the effect of the present invention is more excellent. -1 is preferable, 80 to 1000 m -1 is more preferred. The parameter X can be adjusted by, for example, the type and content of the visible light absorbing material β added to the substrate, the type of resin constituting the substrate, and the thickness D1 of the substrate.

[0049] The thickness D1 of the substrate is, for example, 400 μm or less, and is preferably 150 μm or less, more preferably 110 μm or less, even more preferably 60 μm or less, and particularly preferably 40 μm or less, in that the effects of the present invention are better, and is preferably 10 μm or more in that the strength of the touch sensor is better. When the substrate has the above-mentioned undercoat layer, the thickness D1 of the substrate also includes the thickness of the undercoat layer. The thickness D1 of the substrate can be adjusted, for example, by the amount of resin used in an extruder to melt the resin constituting the substrate and extrude it onto a cast roll in the method of manufacturing the substrate described below, and the film-forming speed (such as the speed of the cooling roll and the stretching speed linked thereto) when forming the substrate into a film. The thickness D1 of the substrate can be measured using a linear gauge (for example, manufactured by Mitutoyo Corporation). The method for measuring the thickness D1 of the substrate will be described in detail in the Examples below.

[0050] (Method of manufacturing the substrate) A method for producing a substrate containing the visible light absorbent β can include, for example, a method comprising the steps of stretching an unstretched polyester film containing a polyester resin and the visible light absorbent β in a first direction (first stretching step), applying a primer layer-forming composition to at least one main surface of the polyester film stretched in the first direction (primer layer forming step), and stretching the polyester film stretched in the first direction in a second direction perpendicular to the first direction (second stretching step). The method for producing the substrate containing the visible light absorber β is not limited to the above method. Hereinafter, in the manufacturing method of the substrate, the mere expression "film" includes all of an unstretched polyester film, a polyester film stretched in a first direction, and a polyester film stretched in both a first direction and a second direction. Furthermore, the mere expression "film" includes both a polyester film alone and a polyester film having a primer layer on the surface thereof.

[0051] -First stretching process- In the first stretching step, the unstretched polyester film is stretched in a first direction. An unstretched polyester film can be obtained, for example, by drying a polyester resin as a raw material, melting it, passing the resulting melt through a gear pump or a filter, and then extruding it through a die onto a cooling roll and allowing it to cool and solidify. The method for producing the unstretched polyester film containing the visible light absorbing material β is as already explained.

[0052] The polyester resin is melted using, for example, an extruder, which may be a single-screw extruder or a twin-screw extruder. The extrusion is preferably carried out under vacuum or in an inert gas atmosphere. The temperature of the extruder is preferably in the range of from the melting point of the polyester resin used to (melting point + 80°C) or less, more preferably in the range of (melting point + 10°C) to (melting point + 70°C), and even more preferably in the range of (melting point + 20°C) to (melting point + 60°C). When the extruder temperature is (melting point + 10°C) or more, the resin is sufficiently melted. On the other hand, when the extruder temperature is (melting point + 70°C) or less, decomposition of the polyester, etc. is suppressed, which is preferable. It is preferable to dry the polyester resin raw material to be charged before melting the polyester resin by extrusion. The water content of the polyester resin raw material is preferably 10 to 300 ppm by mass, more preferably 20 to 150 ppm by mass.

[0053] The extruded melt is passed through components such as a gear pump, a filter, and a multi-layer die and then forced onto a casting drum. As the multi-layer die system, both a multi-manifold die and a feed block die can be suitably used. Examples of the die shape include a T-die, a hanger coat die, and a fishtail die. On the casting drum, the molten resin (melt) can be brought into close contact with the cooling roll using an electrostatic application method. The surface temperature of the casting drum can be approximately 10 to 40°C. The diameter of the casting drum is preferably 0.5 to 5 m, more preferably 1 to 4 m. The driving speed of the casting drum (linear speed of the outermost circle) is preferably 1 to 50 m / min, more preferably 3 to 30 m / min.

[0054] Examples of the first direction in which the unstretched polyester film is stretched include the machine direction (MD) and the transverse direction (TD), with the MD being preferred. MD stretching can be performed, for example, by conveying a film using two pairs of rolls and increasing the peripheral speed of the roll on the outlet side to be faster than the roll on the inlet side while heating the film. MD stretching may be performed in one step or multiple steps.

[0055] In the first stretching step, it is preferable to heat the unstretched polyester film. The temperature range during heating is preferably from the glass temperature (Tg: unit: °C) of the polyester film to (Tg + 60°C), more preferably from (Tg + 3°C) to (Tg + 40°C), and even more preferably from (Tg + 5°C) to (Tg + 30°C). The stretching ratio in the first stretching step is preferably 270 to 500%, more preferably 280 to 480%, and even more preferably 290 to 460%. The stretching ratio is calculated using the following formula. Stretching ratio (%) = 100 × {(length in the stretching direction after stretching) / (length in the stretching direction before stretching)}

[0056] - Undercoat layer formation process - In the undercoat layer forming step, a composition for forming an undercoat layer is applied to at least one main surface of a polyester film stretched in a first direction (hereinafter also referred to as a "uniaxially stretched film"). Forming the undercoat layer by coating is preferred because it is simple and allows for the formation of a thin film with high uniformity. As the coating method, for example, known methods such as a gravure coater or a bar coater can be used. The composition for forming the undercoat layer is as described above. The application of the undercoat layer-forming composition to the uniaxially stretched film is preferably carried out in-line following the first stretching step.

[0057] Before applying the undercoat layer-forming composition, the surface of the uniaxially stretched film is preferably subjected to a surface treatment, such as corona discharge treatment, glow discharge treatment, atmospheric pressure plasma treatment, flame treatment, or UV treatment.

[0058] After applying the undercoat layer-forming composition, it is preferable to provide a step of drying the coating film. The drying step is a step of supplying dry air to the coating film, and the average speed of the dry air is preferably from 5 to 30 m / sec, more preferably from 7 to 25 m / sec, and even more preferably from 9 to 20 m / sec. It is preferable that the drying of the coating film also serves as a heat treatment.

[0059] -Second stretching process- In the second stretching step, the uniaxially stretched film on which the coating film of the composition for forming an undercoat layer has been formed is further stretched in a second direction perpendicular to the first direction within the film plane. By stretching in the second direction, the uniaxially stretched film is stretched together with the composition for forming an undercoat layer, and a polyester film coated with an undercoat layer (in-line coating layer) is formed. The second direction in which the film is stretched in the second stretching step may be any direction perpendicular to the first direction. Examples of the second direction include the machine direction (MD) and the transverse direction (TD), with the TD being preferred.

[0060] TD stretching can be carried out, for example, by a stretching method in which both widthwise ends of the film are held with chucks and the distance between the chucks at both ends is enlarged while heating in an oven using a tenter. The preferred aspects of the stretching temperature, stretching ratio, etc. in the second stretching step are the same as those in the first stretching step.

[0061] The second stretching step is preferably followed by a heat setting step. The conditions for the heat setting step are not particularly limited, but it is preferable to subject the film to heat treatment at 175 to 230° C. for 1 to 60 seconds. The heat setting step is preferably carried out, for example, after the second MD stretching step is carried out by the stretching method using the tenter, with both widthwise ends of the film being held by chucks in the tenter. The distance between the chucks at both ends in the heat setting step may be the same as the distance between the chucks at both ends at the end of the second stretching step, or may be enlarged or reduced. By carrying out the heat setting treatment, microcrystals are formed in the film, which can improve the mechanical properties and durability.

[0062] The heat-setting step is preferably followed by a heat-relaxing step. The heat-relaxing step is a treatment in which heat is applied to the film to relax stress, causing the film to shrink. In the heat-relaxing step, the film is preferably relaxed in at least one of the machine direction (MD) and the transverse direction (TD). The amount of relaxation in the heat-relaxing step (the ratio of the length after the heat-relaxing step to the length after the second stretching step) is preferably 1 to 15% in the relaxed direction. The temperature in the heat-relaxing step is preferably (Tg+50) to (Tg+180)°C.

[0063] Thermal relaxation in the TD can be achieved, for example, by reducing the distance between the chucks holding both ends of the film in the tenter. Thermal relaxation in the MD can be achieved by reducing the distance between adjacent chucks in the tenter. More specifically, this can be achieved by connecting adjacent chucks in a pantograph shape and shortening the pantograph. Heat relaxation in the TD can also be carried out by removing the film from the tenter and then heat treating it while transporting it under low tension.

[0064] The film obtained by carrying out the first stretching step, the undercoat layer forming step, and the second stretching step is then, if necessary, subjected to processes such as trimming both ends of the film that were held by the clips and knurling (embossing) both ends of the film, and then wound up. The TD width of the film thus formed is preferably 0.8 to 10 m, more preferably 1 to 6 m. Through the above steps, a substrate made of a biaxially stretched polyester film having an undercoat layer on the surface and containing the visible light absorbing material β is obtained.

[0065] <Detection electrode> The touch sensor of this embodiment includes a detection electrode disposed on at least one surface side of a substrate. The detection electrode is made up of a plurality of thin conductive wires and functions as a sensor electrode for detecting a touch operation. 1 shows a plurality of detection electrodes 11 extending along the Y direction on the surface 1a of the substrate 1 and a plurality of detection electrodes 21 extending along the X direction on the surface 1b of the substrate 1, but only one detection electrode may be disposed on one surface of the substrate. Also, the detection electrode may be disposed on only one surface of the substrate.

[0066] The detection electrode may have a predetermined pattern formed by conductive thin wires. The pattern to be formed is not particularly limited, and is preferably a geometric figure combining a triangle such as an equilateral triangle, an isosceles triangle, or a right-angled triangle, a quadrangle such as a square, a rectangle, a rhombus, a parallelogram, or a trapezoid, a (regular) n-gon such as a (regular) hexagon or a (regular) octagon, a circle, an ellipse, or a star, or the like, and more preferably a mesh shape (mesh pattern). The mesh shape means a shape including a plurality of openings (grids) formed by intersecting thin conductive wires, as shown in FIG. FIG. 3 is a plan view showing an example of the configuration of the detection electrodes of the touch sensor of the present embodiment. In the detection electrode 11 shown in FIG. 3, the mesh pattern in which the openings 52 are shaped like squares with a side length of L is formed by the conductive thin wires 51.

[0067] The shape of the mesh pattern of the detection electrode is not limited to a square and may be other shapes. Examples of the shape of the mesh pattern of the detection electrode include the above-mentioned geometric shapes. Furthermore, the shape of one side of the opening may be straight, curved, or arc-shaped. When the shape is arc-shaped, for example, two opposing sides may be arc-shaped convex outward, and the other two opposing sides may be arc-shaped convex inward. Furthermore, the shape of each side may be a wavy line consisting of a continuous arc convex outward and an arc convex inward. Of course, the shape of each side may be a sine curve. The mesh pattern is not particularly limited, and may be a random pattern or a regular pattern, or may be a regular mesh pattern in which multiple congruent shapes are repeatedly arranged.

[0068] The mesh pattern of the detection electrode is preferably a regular mesh pattern having openings of the same shape, such as diamond or square. From the viewpoint of visibility, the length L of one side of the opening is preferably 5 to 1500 μm, more preferably 10 to 1000 μm. When the length L of one side of the opening is within the above range, it is possible to maintain good transparency, and when the touch sensor is attached to the display surface of an image display device, the displayed image can be viewed without any sense of incongruity. The aperture ratio of the mesh pattern of the detection electrode is preferably 90% or more, more preferably 95% or more, in terms of visible light transmittance. There is no particular upper limit, but it can be less than 100%. The aperture ratio corresponds to the area ratio of the openings, excluding the conductive thin wires, in the region where the detection electrode is provided, to the entire region where the detection electrode is provided. The mesh pattern of the detection electrode can be observed and measured using an optical microscope.

[0069] The width of the conductive thin wire constituting the detection electrode is preferably 10 μm or less, more preferably 5 μm or less, from the viewpoint of superior visibility. There is no particular lower limit, but the width is preferably 0.1 μm or more, more preferably 0.5 μm or more, from the viewpoint of superior conductive properties of the conductive thin wire. The height of the conductive thin wires is not particularly limited, but is, for example, 0.1 to 10 μm, and preferably 0.3 to 5 μm. The line width and height of the conductive thin wire are obtained by using a scanning electron microscope to select any five locations on the conductive thin wire and calculating the arithmetic mean of the values ​​corresponding to the measured line width and height.

[0070] The conductive thin wires preferably contain a metal. As the metal, silver (metallic silver), copper (metallic copper), gold (metallic gold), nickel (metallic nickel), palladium (metallic palladium), or a mixture of two or more of these is preferred because of its superior conductivity, with silver, copper, or a mixture thereof being more preferred, and silver being even more preferred. The conductive thin wire may contain only silver as the metal, and it is preferred that the metal be composed entirely of silver. By using silver as the metal, the occurrence of breakage failures in the conductive thin wire is reduced. The form of the metal in the conductive thin wire is not limited, and examples include a particulate form and a form in which the metal is dispersed in layers within the conductive thin wire.

[0071] The conductive thin wire may be a conductive thin wire containing metallic silver and a polymer binder such as gelatin and acrylic-styrene latex, which is suitable for forming a mesh pattern. When the conductive thin wire contains a polymer binder, the metal particles may be present in a dispersed state in the polymer, or the metal particles may be aggregated in the polymer and present as aggregates. The type of polymer is not particularly limited, and known polymers can be used. The conductive thin wires may be thin metal wires made of aluminum, copper, silver, molybdenum, titanium, or alloys thereof, or may have a laminated structure of these metals, such as molybdenum / copper / molybdenum or molybdenum / aluminum / molybdenum. The conductive thin wires may include metal oxide particles, metal pastes such as silver paste and copper paste, and metal nanowire particles such as silver nanowires and copper nanowires.

[0072] (Other parts) On the surface of the substrate, other members than the detection electrode may be disposed. Examples of other members include electrode connection terminals 12 and 22, peripheral wiring 13 and 23, and external connection terminals 14 and 24 shown in FIG. These members have the function of transmitting the electrical signal detected by the detection electrode to an external device. The touch sensor may have a dummy electrode as another member.

[0073] The touch sensor may be used in the form of a laminate including the touch sensor and other components such as an adhesive sheet and a release sheet during handling and transportation. The release sheet functions as a protective sheet to prevent scratches on the conductive member during transportation of the laminate. The touch sensor may also be handled in the form of a composite including, for example, the touch sensor, the adhesive sheet, and the protective layer in this order.

[0074] <Touch sensor manufacturing method> The method for manufacturing the touch sensor is not particularly limited as long as it is a method that can form the above-mentioned detection electrode on the surface of the substrate manufactured by the above-mentioned method. Examples of methods that can be used to form the detection electrode include sputtering, plating, silver halide coating, and printing.

[0075] A method for forming a detection electrode by sputtering will be described. First, a copper foil layer is formed by sputtering, and then copper wiring is formed from the copper foil layer by photolithography, thereby forming the detection electrode. Instead of sputtering, the copper foil layer can also be formed by so-called vapor deposition. The copper foil layer can be formed using sputtered copper foil, vapor-deposited copper foil, or electrolytic copper foil. More specifically, the process for forming copper wiring described in JP 2014-029614 A can be used.

[0076] A method for forming a detection electrode by plating is described below. For example, a metal plating film is formed on an electroless plating base layer by electroless plating. This metal plating film can be used as the detection electrode. In this case, the detection electrode is formed by forming a pattern of a catalyst ink containing at least metal fine particles on a substrate, and then immersing the substrate in an electroless plating bath to form a metal plating film. More specifically, the method for manufacturing a metal-coated substrate described in JP 2014-159620 A can be used.

[0077] The detection electrode is formed by forming a pattern of a resin composition having functional groups capable of interacting with at least a metal catalyst precursor on a substrate, applying a catalyst or catalyst precursor, and immersing the substrate in an electroless plating bath to form a metal plating film. More specifically, the method for producing a metal-coated substrate described in JP 2012-144761 A can be applied.

[0078] A method for forming a detection electrode using a silver salt method will be described. First, a silver salt emulsion layer containing silver halide is exposed to light using an exposure pattern corresponding to the pattern of the detection electrode, and then developed to form the detection electrode. More specifically, the methods for manufacturing thin metal wires described in JP 2012-006377 A, JP 2014-112512 A, JP 2014-209332 A, JP 2015-022397 A, JP 2016-192200 A, and WO 2016 / 157585 A can be used.

[0079] A method for forming the detection electrode by printing will be described. First, a conductive paste containing conductive powder is applied to a substrate in the same pattern as the detection electrode, and then the substrate is subjected to a heat treatment to form the detection electrode. The pattern formation using the conductive paste is performed by, for example, an inkjet method or a screen printing method. More specifically, the conductive paste described in JP 2011-028985 A can be used as the conductive paste.

[0080] [Touch panel] The touch panel of this embodiment includes the touch sensor of this embodiment, and can be suitably used as a capacitive touch panel. The configuration of the touch panel of this embodiment is not particularly limited except that it includes the touch sensor of this embodiment, and reference can be made to the configuration described in "New Touch Panel Practical Lectures, Special Edition of Monthly Display" edited by Yuji Mitani and Yoshio Itakura (Techno Times Co., Ltd., 2011). Furthermore, the touch panel of this embodiment can be configured as disclosed in "Latest Touch Panel Technology" (Techno Times Co., Ltd., July 6, 2009), "Touch Panel Technology and Development" edited by Yuji Mitani (CMC Publishing Co., Ltd., December 2004), FPD International 2009 Forum T-11 Lecture Textbook, and Cypress Semiconductor Corporation Application Note AN2292. The touch panel may be either an external type or a display-integrated type. An example of an external type is a film sensor. Examples of a display-integrated type include an on-cell type (e.g., FIG. 19 in JP 2013-168125 A) and other configurations (e.g., FIG. 6 in JP 2013-164871 A). The use of the touch panel of this embodiment is not particularly limited, but it is preferable to combine it with an image display element to form an image display device.

[0081] [Image display device] The image display device of this embodiment includes an image display element and the touch sensor of this embodiment. The image display device can be used as a touch panel (capacitive touch panel) by the image display element and the touch sensor. An example of the configuration of the image display device of this embodiment is an image display device 100 shown in Figure 2, which has an image display element 30, an adhesive layer 4, a touch sensor 10 of this embodiment, an adhesive layer 4, and a protective layer 40 in this order.

[0082] The image display element can be an element having a display surface for displaying images, etc., and examples thereof include a liquid crystal display element, an organic electroluminescent display element (OLED), a cathode ray tube (CRT) image display device, a vacuum fluorescent display (VFD), a plasma display panel (PDP), a surface-emitting diode (SED), a field emission display (FED), and electronic paper. As the image display element, an image display element having a form appropriate for the intended use is used as appropriate. In terms of enabling the image display device to be made thinner, an image display element having a panel form such as a liquid crystal display panel or an organic electroluminescence display panel is preferred.

[0083] As shown in FIG. 2, the image display device may further have a protective layer on the viewing side of the touch sensor (the side opposite to the image display element). In this case, the surface on the viewing side of the protective layer is the touch surface and the operation surface of the image display device. That is, the surface on the viewing side of the protective layer serves as the operation surface for input operation. The touch surface means a surface that detects contact with a finger, a stylus pen, or the like. The surface on the viewing side of the protective layer is the viewing surface for an image displayed on the display surface of the image display element. Since the surface of the protective layer is the touch surface, a hard coat layer may be provided on the surface as needed. In addition, it is preferable to subject the surface of the protective layer to treatments that impart various functions, such as anti-scratch treatment, anti-glare treatment, anti-fouling treatment, anti-fogging treatment, and anti-reflection treatment.

[0084] The configuration of the protective layer is not particularly limited, but is preferably transparent so that the image displayed on the display surface of the image display element can be seen. Examples of the protective layer include a plastic film, a plastic plate, and a glass plate. The thickness of the protective layer is preferably selected appropriately depending on the intended use. A protective layer made of glass is called a cover glass. Examples of raw materials for the above-mentioned plastic films and plastic plates include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefins such as polyethylene (PE), polypropylene (PP), polystyrene and EVA (polyethylene vinyl acetate copolymer), vinyl resins, polycarbonate (PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC), cycloolefin resin (COP), polyvinylidene fluoride (PVDF), polyarylate (PAR), polyethersulfone (PES), polymeric acrylic resin, fluorene derivatives, and polymers such as crystalline COP. Furthermore, a polarizing plate, a circular polarizing plate, or the like may be used as the protective layer.

[0085] In terms of weight reduction and contrast improvement, the protective layer is preferably thin. Specifically, the thickness of the protective layer is preferably 1 mm or less, more preferably 0.5 mm or less, and even more preferably 0.3 mm or less. The lower limit is not particularly limited, and may be, for example, 0.1 mm or more. The refractive index of the protective layer is preferably 1.40 to 1.70, and the difference in refractive index between the protective layer and other members is preferably 0.1 or less.

[0086] The image display device may further include an adhesive layer disposed between the substrate and other members such as the image display element and the protective layer. An image display device in which an image display element, an adhesive layer, and the touch sensor of this embodiment are arranged in this order is one of the preferred aspects of this embodiment. The pressure-sensitive adhesive layer is not particularly limited in its configuration, as long as it is transparent, electrically insulating, and has the function of fixing the substrate to other members. The adhesive layer may be made of, for example, an optically clear adhesive (OCA) or an optically clear resin (OCR) such as a UV (Ultra Violet) curable resin. The adhesive layer may further contain a visible light absorbing material β. The thickness of the pressure-sensitive adhesive layer is preferably 0.5 mm or less, more preferably 0.25 mm or less, and even more preferably 0.15 mm or less. There is no particular lower limit, and the thickness may be, for example, 10 μm or more.

[0087] [Second embodiment: image display device] The image display device according to the second embodiment of the present invention includes an image display element having a display region and a non-display region, and an optical member. The image display device of this embodiment will be described in detail below with reference to the drawings.

[0088] FIG. 4 is a schematic cross-sectional view showing an example of the image display device of this embodiment. The image display device 110 shown in FIG. 4 includes an image display element 120, a pressure-sensitive adhesive layer 130, and an optical member 140 arranged in this order in the stacking direction (thickness direction). In the image display device 110, an image (not shown) is displayed on the entire surface of the display surface 120a, which is the surface of the image display element 120 facing the optical member 140. The image displayed on the display surface 120a is visible through the adhesive layer 130 and the optical member 140. That is, the display surface 120a is the display area of ​​the image display element 120, and the optical member 140 is disposed so as to cover the display surface 120a (display area). In addition, the surface of the image display element 120 facing the optical member 140 also has a non-display area (not shown) where no image is displayed.

[0089] FIG. 5 is a schematic cross-sectional view showing another example of the image display device of this embodiment. The image display device 200 shown in FIG. 5 includes an image display element 220, an adhesive layer 230, a touch sensor 210, an adhesive layer 230, and an optical member 240 stacked in this order in the stacking direction. In the image display device 200, an image (not shown) is displayed on the entire surface of the display surface 220a, which is the surface of the image display element 220 facing the optical member 240. The image displayed on the display surface 220a is visible through the two pressure-sensitive adhesive layers 230, the touch sensor 210, and the optical member 240. That is, the display surface 220a is the display area of ​​the image display element 220, and the optical member 240 is disposed so as to cover the display surface 220a (display area). In addition, the surface of the image display element 220 facing the optical member 240 also has a non-display area (not shown) where no image is displayed.

[0090] The touch sensor 210 has a substrate 201, a detection electrode 211 arranged on one surface 201a of the substrate 201, and a detection electrode 221 arranged on the other surface 201b of the substrate 201. The substrate 201 has a multi-layer structure consisting of a support 202 and undercoat layers 203 arranged on both surfaces of the support 202. The image display device 200 can be used as a touch panel (capacitive touch panel) by the image display element 220 and the touch sensor 210. A surface 240a of the optical member 240 opposite to the touch sensor 210 is the touch surface of the image display device 200 and serves as the operation surface.

[0091] The image display device of this embodiment is an image display device having an image display element having a display area and a non-display area, and an optical member covering the display area, wherein the refractive index of the optical member is 1.55 or more, the optical member contains a visible light absorber α, the internal absorbance A2 of the optical member calculated by test X2 described later is 0.0004 to 0.03, and the parameter X2 is 30 to 3000 m -1 It is characterized in that:

[0092] The mechanism by which the image display device of this embodiment exhibits excellent contrast between black and white display and excellent performance in suppressing a decrease in white display luminance when displaying black and white is not entirely clear, but the inventors speculate as follows. The inventors of the present invention have conducted extensive research into improving the contrast of image display devices, and have concluded that when a black display portion and a white display portion are simultaneously displayed in an image display device, a portion of the light emitted from the white display portion is transmitted or propagated through the interior of an optical member laminated on an image display element by scattering or reflection, etc., toward the black display portion adjacent to the white display portion, and reaches the position where the viewer views the image, possibly resulting in an increase in the luminance of the black display. In particular, when the refractive index of an optical member is 1.55 or higher, reflection with adjacent members is likely to occur, and therefore the light is propagated within the optical member, and the luminance of the black display tends to increase. Based on this assumed mechanism, we found that by adding a visible light absorbing material to an optical component and reducing the light that passes through or propagates inside the optical component, it is possible to significantly suppress the increase in brightness of a black display displayed adjacent to a white display, thereby improving the contrast between the black display and the white display. Furthermore, in the image display device of this embodiment, the internal absorbance A2 and parameter X2 of the optical member measured by a predetermined test method are each specified within a predetermined range. This suppresses the reduction in light emitted from the image display element in the white display area, hardly impairs the luminance of the white display, and even if the refractive index of the optical member is 1.55 or more, suppresses the increase in luminance of the black display, and improves contrast, so it is presumed that significantly excellent display characteristics can be realized.

[0093] Hereinafter, each member included in the image display device of this embodiment will be described in detail. The image display device of this embodiment is not limited to the aspects shown in Figures 4 and 5. For example, an intermediate layer other than the pressure-sensitive adhesive layer and the touch sensor may be disposed between the optical member and the image display element. In addition, in the touch sensor of the image display device, the detection electrode may be disposed on only one surface of the substrate. In addition, the substrate of the touch sensor may have a multilayer structure having a support and an undercoat layer formed on only one surface of the support, or may be composed of the substrate alone without the undercoat layer.

[0094] <Image display element> As the image display element, an element having a display area for displaying an image or the like and a non-display area for not displaying an image or the like can be used. Details of the image display element, including preferred aspects, are as already described in Embodiment 1. As the image display element, it is preferable to use an organic electroluminescence display element (OLED). As shown in Figure 5, when an image display device has a touch sensor, a detection electrode is often arranged in the area of ​​the main surface of the touch sensor that overlaps with the display area when viewed from the stacking direction, and peripheral wiring is often arranged in the area that overlaps with the non-display area when viewed from the stacking direction.

[0095] <Optical components> The image display device has an optical member that covers the display area of ​​the image display element. The surface of the optical member on the viewing side becomes the viewing surface for the image displayed on the display surface of the image display element.

[0096] The optical member is not particularly limited as long as it contains the visible light absorbing material α and the refractive index, internal absorbance A2, and parameter X2 fall within predetermined ranges, and for example, a resin substrate such as a resin film or resin plate is used. Examples of materials that can be used to form optical components include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefins such as polyethylene (PE), polypropylene (PP), polystyrene, and EVA (polyethylene vinyl acetate copolymer), vinyl resins, polycarbonate (PC) resins, polyamide resins, polyimide resins, acrylic resins, triacetyl cellulose (TAC), cycloolefin resins (COP), polyvinylidene fluoride (PVDF), polyarylate (PAR), polyethersulfone (PES), polymeric acrylic resins, fluorene derivatives, crystalline COP, diacetate resins, triacetate resins, polystyrene resins, polyurethane resins, and polyvinyl chloride. The optical member may be a single layer of the above resin, or may be a composite film composed of a plurality of resin layers.

[0097] As the optical member, a film made of polyester resin is preferred because it is easy to manufacture. Examples of polyester resins include linear saturated polyesters synthesized from an aromatic dibasic acid or its ester-forming derivative and a diol or its ester-forming derivative. Specific examples of linear saturated polyesters include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly(1,4-cyclohexylene dimethylene terephthalate), and polyethylene-2,6-naphthalate. Among these, polyethylene terephthalate, polyethylene-2,6-naphthalate, and poly(1,4-cyclohexylene dimethylene terephthalate) are preferred in terms of the balance between mechanical properties and cost. The polyester resin may be a homopolymer or a copolymer, and may also be a mixture of a polyester resin and a small amount of another type of resin, such as polyimide.

[0098] The content of the resin contained in the optical member is preferably 75% by mass or more, and more preferably 90% by mass or more but less than 100% by mass, based on the total mass of the optical member.

[0099] (Visible light absorber α) The visible light absorbing material α contained in the optical member may be any substance having an absorption wavelength characteristic of absorbing visible light (wavelength 380 to 780 nm), and for example, a substance having a maximum absorption wavelength of 380 to 780 nm can be used. Details of the visible light absorbent material α, including preferred embodiments, are the same as those described in the first embodiment as the explanation of the visible light absorbent material β.

[0100] The visible light absorbing material α may be used alone or in combination of two or more. From the viewpoint of preventing impairment of the display function of the display due to light scattering, the content of the visible light absorber α (preferably a black pigment) is preferably 5000 ppm by mass or less, more preferably 500 ppm by mass or less, even more preferably 200 ppm by mass or less, and particularly preferably 100 ppm by mass or less, relative to the total mass of the optical component. The lower limit is not particularly limited as long as the internal absorbance can be made equal to or greater than a predetermined value, but is preferably 5 ppm by mass or more, more preferably 10 ppm by mass or more, relative to the total mass of the optical component.

[0101] Various known methods can be applied to the method for producing an optical member containing the visible light absorbent material α. A typical example of the method is a method in which a resin containing the visible light absorbent material α is produced and then an optical member is produced using the resin. The details of the method for producing a resin containing the visible light absorbent material α and the method for producing an optical component using a resin containing the visible light absorbent material α, including preferred aspects, are as already described in the first embodiment.

[0102] In addition to the resin and visible light absorber α, the optical component may further contain additives such as a light stabilizer, an antioxidant, an ultraviolet absorber, a flame retardant, a lubricant (fine particles), a nucleating agent (crystallization agent), and a crystallization inhibitor.

[0103] The optical member may have an undercoat layer on at least one of its two main surfaces, i.e., the optical member may have a multi-layer structure consisting of a support and an undercoat layer. When the optical member has a multilayer structure of a support and an undercoat layer, the undercoat layer is preferably disposed on the main surface of the support facing the touch sensor. Undercoat layers may be disposed on both surfaces of the support. As the support having a multilayer structure with the undercoat layer, the members listed above as optical members can be used. The undercoat layer and the method for forming the undercoat layer, including preferred aspects, are as described in the first embodiment regarding the undercoat layer of the substrate and the method for forming the undercoat layer on the main surface of the substrate.

[0104] (Physical properties of optical components, etc.) The optical member of the image display device of this embodiment has an internal absorbance A2 calculated by the following test X2 of 0.0004 to 0.03, and a parameter X2 of 30 to 3000 m -1 is. Test X2: The visible light reflectance ρ0 of the supporting white plate is obtained using the method described in JIS R 3106:2019. Similarly, using the method described in JIS R 3106:2019, a measurement light is incident on the optical member side of a laminate formed by laminating a supporting white plate and an optical member to obtain a visible light reflectance ρ2. From the obtained visible light reflectance ρ0 and visible light reflectance ρ2, the internal absorbance A2 of the optical member is calculated using the following formula (2-1). From the calculated internal absorbance A2 and the thickness D2 (m) of the optical member, the parameter X2 (m) is calculated using the following formula (2-2). -1 ) is calculated. Equation (2-1) A2= -log 10 {(ρ2 / ρ0) 0.5} Formula (2-2) X2= A2 / D2 The supporting white plate can be a commercially available standard white plate (perfect diffuser plate) for measuring total light spectral reflectance. More specifically, for example, a barium sulfate plate or a Spectralon standard reflector plate can be used.

[0105] As already explained in the first embodiment, the internal absorbance A2 of the optical member can be calculated from the visible light reflectance ρ2 of the laminate and the visible light reflectance ρ0 of the supporting white plate using formula (2-1). The visible light reflectance ρ0 of the supporting white plate and the visible light reflectance ρ2 of the laminate are obtained according to the measurement method and calculation method for visible light reflectance described in JIS R 3106:2019. A more specific method for carrying out test X2 will be described in the Examples below. Hereinafter, the "visible light reflectance ρ0" and the "visible light reflectance ρ2" will also be referred to as "reflectance ρ0" and "reflectance ρ2", respectively.

[0106] The internal absorbance A2 of the optical member represents the degree of attenuation of light inside the optical member, and reflection on both main surfaces of the optical member does not affect the internal absorbance A2 or parameter X2. It is presumed that by setting the internal absorbance A2 and parameter X2 within the above ranges, it is possible to suppress an increase in the brightness of the black display due to the transmission and propagation of light inside the optical member while maintaining the brightness of the white display transmitted along the stacking direction of the touch sensor, thereby improving the contrast between the black display and the white display.

[0107] The internal absorbance A2 is preferably 0.0010 to 0.0050 in terms of achieving better effects of the present invention. The internal absorbance A1 can be adjusted by, for example, the type and content of the visible light absorbing material α added to the optical member, the type of resin constituting the optical member, and the thickness D2 of the optical member.

[0108] The parameter X of the optical member is 40 to 3000 m, which is the range where the effect of the present invention is more excellent. -1 is preferable, 80 to 1000 m -1 is more preferred. The parameter X can be adjusted by, for example, the type and content of the visible light absorbing material α added to the optical member, the type of resin constituting the optical member, and the thickness D2 of the optical member.

[0109] The refractive index of the optical member included in the image display device of this embodiment is 1.55 or more, and preferably 1.55 to 1.70. In the image display device, the difference in refractive index between the optical member and other members is preferably 0.1 or less.

[0110] The thickness D2 of the optical element is, for example, 400 μm or less, and is preferably 200 μm or less, more preferably 110 μm or less, even more preferably 70 μm or less, and particularly preferably 50 μm or less, in that the effects of the present invention are better; and is preferably 10 μm or more, more preferably 20 μm or more, in that the strength of the touch sensor is better. When the optical member has the above-mentioned undercoat layer, the thickness D2 of the optical member also includes the thickness of the undercoat layer. The thickness D2 of the optical component can be adjusted, for example, by the amount of resin used in an extruder to melt the resin constituting the optical component and extrude it onto a cast roll during the production of the optical component, and the film-forming speed (such as the speed of the cooling roll and the stretching speed associated with this) during the film-forming of the optical component. The method for measuring the thickness D2 of the optical member is the same as that described for the method for measuring the thickness D1 of the substrate in the first embodiment.

[0111] When the image display device has a touch sensor, the surface of the optical member on the viewing side serves as a touch surface, and therefore a hard coat layer may be provided on the surface of the optical member on the viewing side. Furthermore, it is preferable to subject the surface of the optical member on the viewing side to treatments that impart various functions, such as anti-scratch treatment, anti-glare treatment, anti-fouling treatment, anti-fogging treatment, and anti-reflection treatment, as necessary.

[0112] A method for producing an optical member containing a visible light absorbent α may include, for example, a method including a step of stretching an unstretched polyester film containing a polyester resin, a visible light absorbent α, etc. in a first direction (first stretching step), and a step of stretching the polyester film stretched in the first direction in a second direction perpendicular to the first direction (second stretching step). Details of the method for producing an optical member including the first stretching step and the second stretching step, including preferred aspects, are as described for the method for producing a substrate in the first embodiment. The method for producing an optical member containing the visible light absorbing material α is not limited to the above method.

[0113] <Adhesive layer> The image display device may have a pressure-sensitive adhesive layer, which is disposed, for example, between the optical member and the image display element. Furthermore, when a touch sensor is arranged between the optical element and the image display element, it is preferable that the image display element, the adhesive layer, and the touch sensor are arranged in this order, and it is also preferable that the touch sensor, the adhesive layer, and the optical element are arranged in this order, and it is more preferable that the image display element, the adhesive layer, the touch sensor, the adhesive layer, and the optical element are arranged in this order, as shown in Figure 5.

[0114] The pressure-sensitive adhesive layer is not particularly limited in its configuration, as long as it is transparent, electrically insulating, and has the function of fixing two members together. The adhesive layer may be made of, for example, an optically clear adhesive (OCA) or an optically clear resin (OCR) such as a UV (Ultra Violet) curable resin. The adhesive layer may further contain a visible light absorbing material α. The thickness of the pressure-sensitive adhesive layer is preferably 0.5 mm or less, more preferably 0.25 mm or less, and even more preferably 0.15 mm or less. There is no particular lower limit, and the thickness may be, for example, 10 μm or more.

[0115] <Touch sensor> The image display device may further include a touch sensor disposed between the optical member and the image display element. The touch sensor included in the image display device of this embodiment is not particularly limited, and any known touch sensor can be used. As a touch sensor, the touch sensor of the first embodiment is preferred in that it improves the contrast between black and white displays when black and white displays are displayed, and the touch sensor described as a preferred embodiment in the first embodiment is more preferred.

[0116] It should be noted that the touch sensor of the image display device of this embodiment may be a touch sensor other than the touch sensor of the first embodiment (for example, a touch sensor having a base material that does not contain a visible light absorbing material, a touch sensor having a parameter X of 30 m -1Even in the case of a touch sensor having a substrate of less than 1000 nm, in this embodiment, the display performance of an image display device having a touch sensor can be improved by suppressing an increase in the brightness of the black display area when displaying black and white, thereby suppressing a decrease in contrast.

[0117] The image display device may include other functional layers in addition to those described above, such as an anti-reflection layer and a protective layer.

[0118] The method for manufacturing the image display device is not particularly limited, and may include, for example, a step of bonding together the optical member, the image display element, and optionally, members such as a touch sensor and other functional layers via an adhesive layer. Also, for example, it may include a step of transferring a member provided on a temporary substrate to another member. Each step can be carried out according to a known method.

[0119] The present invention is basically configured as described above. The present invention is not limited to the above-described embodiment, and various improvements and modifications may be made without departing from the spirit and scope of the present invention. [Example]

[0120] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

[0121] [Example 1] [Preparation of substrate] -Preparation of polyester-containing pellets- A mixed slurry of 100 kg of high-purity terephthalic acid (manufactured by Mitsui Chemicals, Inc.) and 45 kg of ethylene glycol (manufactured by Nippon Shokubai Co., Ltd.) was prepared in a reactor containing approximately 123 kg of bis(hydroxyethyl) terephthalate, at a temperature of 250°C and a pressure of 1.2 x 10 5The materials were sequentially supplied to the esterification reaction tank maintained at Pa over a period of 4 hours, and the esterification reaction was continued for another hour after the supply was completed. Thereafter, 123 kg of the obtained esterification reaction product was transferred to the polycondensation reaction tank. Next, ethylene glycol was added to the polycondensation reactor to which the esterification reaction product was transferred, at a concentration of 0.3% by mass relative to the resulting polymer. After stirring for 5 minutes, an ethylene glycol solution of magnesium acetate tetrahydrate was added to the resulting polymer at 70 ppm by mass. After stirring for another 5 minutes, a 2% by mass ethylene glycol solution of a titanium alkoxide compound was added to the resulting polymer at 10 ppm by mass. Five minutes later, a 10% by mass ethylene glycol solution of trimethyl phosphate was added to the resulting polymer at 60 ppm by mass. The mixture containing the oligomer was then stirred at 30 rpm while the reaction system was gradually heated from 250°C to 27.5°C, and the pressure was reduced to 40 Pa. The time required to reach the final temperature and pressure was 60 minutes. When the predetermined stirring torque was reached, the reaction system was purged with nitrogen and returned to atmospheric pressure (101.325 kPa) to terminate the polycondensation reaction. The polymer obtained by the polycondensation reaction was extruded into cold water in the form of strands and immediately cut into polymer pellets (approximately 3 mm in diameter and 7 mm in length). The time from the start of pressure reduction until the predetermined stirring torque was reached was 3 hours. Here, the titanium alkoxide compound used was a titanium alkoxide compound (Ti content=4.44 mass %) synthesized according to the synthesis method described in Example 1 of paragraph

[0083] of JP-A No. 2005-340616.

[0122] -Making master pellets- Titanium oxynitride was added as a visible light absorber β to a portion of the pellets and kneaded to prepare master pellets. The amount of titanium oxynitride added was such that the content of titanium oxynitride relative to the total mass of the master pellets was 0.5% by mass. Here, UF-8 (trade name; average primary particle size=20 nm) manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd. was used as the titanium oxynitride.

[0123] -Preparation of substrate- The pellets and master pellets were mixed to obtain a mixture A. The mixing ratio of the pellets and master pellets was adjusted so that the titanium oxynitride content was 50 ppm by mass relative to the total mass of mixture A (total amount of the pellets and master pellets). The obtained mixture A was melted at 280°C and cast onto a metal drum to produce an unstretched polyethylene terephthalate (PET) film with a thickness of approximately 0.5 mm. Then, the unstretched PET film was stretched 3.5 times in the machine direction (MD) at 90°C. Next, a composition for forming an undercoat layer having the following composition was applied to both sides of the stretched uniaxially stretched PET film in an amount of 5.4 mL / m2 per surface area of ​​the film. 2 The coating was carried out by an in-line coating method so that the

[0124] (Composition of the undercoat layer-forming composition) Water 76.9% by mass (water other than the water contained in the chemicals listed below) Surfactant 0.3% by mass Snowtex ST-ZL (Nissan Chemical Co., Ltd.) 0.3% by mass Carbodilite V-02 (manufactured by Nisshinbo Chemical Inc.) 2.5% by mass 20% by mass of a polymer latex containing a polymer (hereinafter also referred to as "Polymer 1") represented by the following formula (P-1), a dispersant consisting of dialkylphenyl PEO (Polyethylene oxide) sulfate ester, and water (the ratio of the mass of the dispersant to the mass of Polymer 1 (mass of dispersant / mass of Polymer 1, unit: g / g) is 0.02, and the solid content is 25% by mass).

[0125] [ka]

[0126] Polymer 1 was synthesized with reference to Japanese Patent Nos. 3305459 and 3754745.

[0127] The PET film coated on both sides with the undercoat layer-forming composition was stretched in the transverse direction (TD) at a temperature of 140° C. and a stretch ratio of 4. The PET film with the undercoat layer formed thereon was subjected to heat setting treatment at 240°C for 5 seconds on the film surface, and then heat relaxation treatment in the MD and TD directions at 200°C with an MD relaxation rate of 5% and a TD relaxation rate of 5%, to obtain a biaxially stretched PET film (hereinafter also referred to as "substrate 1") having a 0.05 μm thick undercoat layer on both main surfaces, a thickness D1 of 40 μm, and containing a visible light absorber β.

[0128] [Fabrication of Touch Sensor] Conductive patterns were formed on both sides of the substrate 1 by the following method to obtain a touch sensor.

[0129] - Preparation of silver halide emulsion - To the following solution 1, maintained at a temperature of 28°C and a pH of 4.5, 90% of each of the following solutions 2 and 3 were added simultaneously over 20 minutes while stirring the solution 1, forming 0.08 μm core grains. Next, the following solutions 4 and 5 were added to the resulting mixture over 8 minutes, and then the remaining 10% of the following solutions 2 and 3 were added over 2 minutes, growing the core grains to 0.10 μm. Furthermore, 0.15 g of potassium iodide was added to the resulting mixture, and the mixture was aged for 5 minutes to complete grain formation.

[0130] 1 liquid: 750mL water 8.6g gelatin 3g potassium bromide 1,3-dimethylimidazolidine-2-thione 20mg Sodium benzenethiosulfonate 10mg Citric acid 0.7g 2 liquid: 300mL water Silver nitrate 150g 3 liquid: 300mL water 38g sodium chloride 32g potassium bromide Potassium hexachloroiridate(III) (0.005%KCl 20% aqueous solution) 5mL Ammonium hexachlororhodate (0.001%NaCl 20% aqueous solution) 7mL 4 liquid: 100mL water Silver nitrate 50g 5 liquid: 100mL water Sodium chloride 13g Potassium bromide 11g Yellow prussic acid 5mg

[0131] The particles were then washed with water by a conventional flocculation method. Specifically, the temperature of the above-mentioned mixed solution was lowered to 35°C, and the pH of the mixed solution was lowered using sulfuric acid until the silver halide particles precipitated (pH was in the range of 3.6 ± 0.2). Next, approximately 3 liters of the supernatant liquid was removed from the mixed solution (first water wash). Next, 3 liters of distilled water was added to the mixed solution from which the supernatant liquid had been removed, and then sulfuric acid was added until the silver halide particles precipitated. Again, 3 liters of the supernatant liquid was removed from the mixed solution (second water wash). The same operation as the second water wash was repeated once more (third water wash), completing the washing and desalting process. After washing and desalting, the pH of the emulsion was adjusted to 6.4 and the pAg to 7.5, and then 2.5 g of gelatin, 10 mg of sodium benzenethiosulfonate, 3 mg of sodium benzenethiosulfinate, 15 mg of sodium thiosulfate, and 10 mg of chloroauric acid were added to the emulsion, followed by chemical sensitization at 55°C to obtain the optimum sensitivity. Subsequently, 100 mg of 1,3,3a,7-tetraazaindene as a stabilizer and 100 mg of Proxel (trade name, manufactured by ICI Co., Ltd.) as a preservative were added to the emulsion. The finally obtained emulsion was a silver chlorobromide cubic grain emulsion containing 0.08 mol % of silver iodide, with a silver chlorobromide ratio of 70 mol % of silver chloride and 30 mol % of silver bromide, an average grain diameter (equivalent to a sphere) of 100 nm, and a coefficient of variation of 9%.

[0132] -Preparation of composition for forming photosensitive layer- The above emulsion was treated with 1,3,3a,7-tetraazaindene (1.2 × 10 -4 mol / mol Ag), hydroquinone (1.2 × 10 -2 mol / mol Ag), citric acid (3.0 × 10 -4 The composition was then adjusted to a pH of 5.6 with citric acid. A polymer latex containing polymer 1, a dispersant consisting of dialkylphenyl PEO sulfate, and water (the ratio of the mass of dispersant to the mass of polymer 1 (mass of dispersant / mass of polymer 1, unit: g / g) was 0.02, and the solid content was 22 mass%) was added to the above composition so that the ratio of the mass of polymer 1 to the total mass of gelatin in the composition (mass of polymer 1 / mass of gelatin, unit: g / g) was 0.25 / 1, thereby obtaining a polymer latex-containing composition. Here, in the polymer latex-containing composition, the ratio of the mass of gelatin to the mass of silver derived from silver halide (mass of gelatin / mass of silver derived from silver halide, unit: g / g) was 0.11. Furthermore, EPOXY RESIN DY 022 (trade name: manufactured by Nagase ChemteX Corporation) was added as a crosslinking agent. The amount of the crosslinking agent added was determined so that the amount of the crosslinking agent in the silver halide-containing photosensitive layer described below was 0.09 g / m 2 It was adjusted so that In this manner, a composition for forming a photosensitive layer was prepared.

[0133] (Process H, Process A, Process I) Next, a composition for forming a silver halide-free layer, which was a mixture of the above-mentioned polymer latex and gelatin, a composition for forming a photosensitive layer, and a composition for forming a protective layer, which was a mixture of the above-mentioned polymer latex and gelatin, were simultaneously coated in multiple layers on the undercoat layer on one side of the above-mentioned substrate 1, thereby forming a silver halide-free layer, a silver halide-containing photosensitive layer, and a protective layer on the undercoat layer. The thickness of the silver halide-free layer was 2.0 μm, the mixture mass ratio of polymer 1 to gelatin in the silver halide-free layer (polymer 1 / gelatin) was 2 / 1, and the content of polymer 1 was 1.3 g / m 2 It was. The thickness of the silver halide-containing photosensitive layer was 2.5 μm, the mixture mass ratio of polymer 1 to gelatin in the silver halide-containing photosensitive layer (polymer 1 / gelatin) was 0.25 / 1, and the content of polymer 1 was 0.19 g / m 2 It was. The thickness of the protective layer was 0.15 μm, the mixture mass ratio of polymer 1 to gelatin in the protective layer (polymer 1 / gelatin) was 0.1 / 1, and the content of polymer 1 was 0.015 g / m 2 It was. Furthermore, in the same manner as above, a silver halide-free layer, a silver halide-containing photosensitive layer, and a protective layer were formed on the undercoat layer on the other surface of the substrate 1. Hereinafter, the obtained photosensitive layer-containing laminate will also be referred to as "photosensitive member A."

[0134] (Process B) The photosensitive layer of the photosensitive member A thus fabricated was exposed to parallel light from a high-pressure mercury lamp as a light source through a photomask having a pattern corresponding to the mesh pattern shown in FIG. 3. A pattern-forming mask was used as the photomask. The photosensitive layer was exposed while the photomask was in contact with the photosensitive member A. The shape of the photomask and the exposure conditions were set so that a unit square lattice having openings with a side length L of 400 μm was formed in the detection electrode of the touch sensor 1 obtained in step G, which will be described later, and the line width w of the thin metal wires was 1.8 μm.

[0135] After exposure, the obtained sample was developed with a developer described below, and further developed with a fixer (product name: N3X-R for CN16X: manufactured by Fujifilm Corporation). Thereafter, it was rinsed with pure water at 25°C and dried to obtain a sample having a silver-containing layer containing metallic silver formed in a mesh pattern.

[0136] (Developer composition) The following compounds are contained in 1 liter (L) of developer: Hydroquinone 0.037 mol / L N-methylaminophenol 0.016 mol / L Sodium metaborate 0.140 mol / L Sodium hydroxide 0.360 mol / L Sodium bromide 0.031 mol / L Potassium metabisulfite 0.187 mol / L

[0137] The obtained sample was immersed in warm water at 50° C. for 180 seconds, then the water was removed with an air shower and the sample was allowed to dry naturally.

[0138] (Process C) The sample obtained in step B was placed in a superheated steam treatment tank at 110°C and left to stand for 30 seconds to undergo superheated steam treatment. The steam flow rate at this time was 100 kg / h.

[0139] (Process D) The sample obtained in step C was immersed in an aqueous protease solution (40°C) for 30 seconds. The sample was removed from the aqueous protease solution and washed by immersing it in warm water (liquid temperature: 50°C) for 120 seconds. Thereafter, the water was removed with an air shower and the sample was allowed to dry naturally. The aqueous protease solution used was prepared according to the following procedure. Triethanolamine and sulfuric acid were added to an aqueous solution of a protease (Biophrase 30L, manufactured by Nagase ChemteX Corporation) (protease concentration: 0.5% by mass) to adjust the pH to 8.5.

[0140] (Process E) The sample obtained in step D was immersed in a 1% by mass, pH 2.7 aqueous glutaric acid solution (74°C) for 30 seconds. The sample was removed from the aqueous glutaric acid solution and washed by immersing it in water at 30°C for 5 seconds. Glutaric acid manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. was used.

[0141] (Process F) The sample obtained in step E was immersed for 5 minutes in plating solution A (30°C) having the following composition: The sample was removed from plating solution A and washed by immersing it in water (liquid temperature: 20°C) for 120 seconds. The composition of plating solution A (total volume 1200 mL) was as follows. The pH of plating solution A was 9.9, which was adjusted by adding a predetermined amount of potassium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). All of the following components used were manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. No change in line width was observed before and after the plating process.

[0142] (Composition of plating solution A) 2.1g AgNO3 Sodium sulfite 86g Sodium thiosulfate pentahydrate 60g Aron T-50 (manufactured by Toagosei Co., Ltd., solid content 40%) 36g Methylhydroquinone 13g Potassium carbonate (prescribed amount) water remainder

[0143] (Process G) The sample obtained in step F was placed in a superheated steam treatment tank at 110°C and left to stand for 30 seconds to undergo superheated steam treatment. The steam flow rate was 100 kg / h. This resulted in the production of touch sensor 1 of Example 1.

[0144] [Example 2] In producing the substrate of Example 1, the mixing ratio of the above pellets and master pellets was adjusted to prepare mixture B in which the titanium oxynitride content relative to the total mass of the mixture was 32 mass ppm, and the obtained mixture B was used to produce an unstretched PET film with a thickness of approximately 0.2 mm.In the same manner as in Example 1, a biaxially stretched PET film (substrate 2) having an undercoat layer on both main surfaces, a thickness D1 of 20 μm, and containing visible light absorber β, and a touch sensor 2 of Example 2 having substrate 2 were produced.

[0145] [Example 3] In producing the substrate of Example 1, the mixing ratio of the above pellets and master pellets was adjusted to prepare mixture C in which the titanium oxynitride content relative to the total mass of the mixture was 20 mass ppm, and the obtained mixture C was used to produce an unstretched PET film with a thickness of approximately 0.4 mm. Except for this, a biaxially stretched PET film (substrate 3) having an undercoat layer on both main surfaces, a thickness D1 of 40 μm, and containing visible light absorber β, and a touch sensor 3 of Example 3 having substrate 3 were produced in the same manner as in Example 1.

[0146] [Example 4] In producing the substrate of Example 1, the mixing ratio of the above pellets and master pellets was adjusted to prepare mixture D in which the titanium oxynitride content relative to the total mass of the mixture was 500 mass ppm, and the obtained mixture D was used to produce an unstretched PET film with a thickness of approximately 0.4 mm. Except for this, a biaxially stretched PET film (substrate 4) having an undercoat layer on both main surfaces, a thickness D1 of 40 μm, and containing visible light absorber β, and a touch sensor 4 of Example 4 having substrate 4 were produced in the same manner as in Example 1.

[0147] [Example 5] In the preparation of the substrate described in Example 1, the mixing ratio of the above pellets and master pellets was adjusted to prepare a mixture E in which the titanium oxide content relative to the total mass of the mixture was 66 mass ppm, and the obtained mixture E was used to prepare an unstretched PET film with a thickness of approximately 1.4 mm. In the same manner as in Example 1, a biaxially stretched PET film (substrate 5) having an undercoat layer on both main surfaces, a thickness D1 of 110 μm, and containing a visible light absorber β, and a touch sensor 5 of Example 5 having substrate 5 were obtained.

[0148] [Example 6] In producing the substrate of Example 1, the mixing ratio of the above pellets and master pellets was adjusted to prepare mixture F in which the titanium oxynitride content relative to the total mass of the mixture was 180 mass ppm, and the obtained mixture F was used to produce an unstretched PET film with a thickness of approximately 1.4 mm. Except for this, a biaxially stretched PET film (substrate 6) having an undercoat layer on both main surfaces, a thickness D1 of 110 μm, and containing visible light absorber β, and a touch sensor 6 of Example 6 having substrate 6 were produced in the same manner as in Example 1.

[0149] [Example 7] A biaxially stretched PET film (substrate 7) having an undercoat layer on both main surfaces, a thickness D1 of 300 μm, and containing visible light absorber β, and a touch sensor 7 of Example 7 having substrate 7 were prepared in the same manner as in Example 5, except that in preparing the substrate of Example 5, mixture E was melted at 280°C and cast onto a metal drum to prepare an unstretched PET film having a thickness of approximately 3.0 mm.

[0150] [Comparative Example 1] In preparing the substrate of Example 1, a biaxially stretched PET film (substrate C1) having a thickness D1 of 40 μm and an undercoat layer on both main surfaces, and a touch sensor C1 of Comparative Example 1 having the substrate C1 were obtained in the same manner as in Example 1, except that in place of mixture A, polyester-containing pellets not containing the visible light absorber β (titanium oxynitride) prepared in Example 1 were used to prepare an unstretched PET film having a thickness of approximately 0.4 mm.

[0151] Comparative Example 2 A biaxially stretched PET film (substrate C2) having undercoat layers on both main surfaces, a thickness D1 of 40 μm, and containing visible light absorber β, and a touch sensor C2 of Comparative Example 2 having the substrate C2 were produced in the same manner as in Example 1, except that in producing the substrate of Example 1, the mixing ratio of the above pellets and master pellets was adjusted to prepare a mixture X in which the content of titanium oxynitride relative to the total mass of the mixture was 2 ppm by mass, and the obtained mixture X was used to produce an unstretched PET film with a thickness of approximately 0.4 mm.

[0152] Comparative Example 3 In producing the substrate of Example 1, the mixing ratio of the above pellets and master pellets was adjusted to prepare a mixture Y in which the titanium oxynitride content relative to the total mass of the mixture was 700 mass ppm, and the obtained mixture Y was used to produce an unstretched PET film with a thickness of approximately 0.4 mm. Except for this, a biaxially stretched PET film (substrate C3) having an undercoat layer on both main surfaces, a thickness D1 of 40 μm, and containing a visible light absorber β, and a touch sensor C3 of Comparative Example 3 having the substrate C3 were produced in the same manner as in Example 1.

[0153] Comparative Example 4 In producing the substrate of Example 1, the mixing ratio of the above pellets and master pellets was adjusted to prepare a mixture Z in which the titanium oxynitride content relative to the total mass of the mixture was 250 mass ppm, and the obtained mixture Z was used to produce an unstretched PET film with a thickness of approximately 1.4 mm. Except for this, a biaxially stretched PET film (substrate C4) having an undercoat layer on both main surfaces, a thickness D1 of 110 μm, and containing a visible light absorber β, and a touch sensor C4 of Comparative Example 3 having substrate C4 were produced in the same manner as in Example 1.

[0154] Comparative Example 5 In the preparation of the substrate of Example 1, the mixing ratio of the above pellets and master pellets was adjusted to prepare a mixture C in which the titanium oxynitride content relative to the total mass of the mixture was 20 mass ppm, and the obtained mixture C was used to prepare an unstretched PET film with a thickness of approximately 3.0 mm. Except for this, a biaxially stretched PET film (substrate C5) having an undercoat layer on both main surfaces, a thickness D1 of 300 μm, and containing a visible light absorber β, and a touch sensor C5 of Comparative Example 5 having substrate C5 were prepared in the same manner as in Example 1.

[0155] [Measurement of substrate thickness] The thickness of the substrate obtained in each example was measured using a linear gauge (Mitutoyo Corporation, separate type gauge head high precision linear gauge "LGH-1010C-B-EH" and linear gauge counter "EH-10S") according to the following procedure. For the substrate of each example, the thickness was measured at nine arbitrarily selected points, and the arithmetic mean value of the measurements at the nine points was taken as the thickness D1 of the substrate.

[0156] [Measurement and evaluation of the optical performance of the substrate] The optical performance of the substrate obtained in each example was measured using a spectrophotometer with an integrating sphere unit (manufactured by JASCO Corporation, ultraviolet-visible spectrophotometer "V-660", integrating sphere unit "ISV-722") according to the following procedure.

[0157] <1> Baseline measurements A Spectralon standard reflector (JASCO Corporation, case-attached standard white plate 6916-H422A) was placed as a support white plate in the reflectance measurement sample holder of the integrating sphere unit, and the visible light reflectance ρ of the support white plate was obtained according to the method described in JIS R 3106:2019.

[0158] <2> Measurement of sample substrate A laminate was prepared by laminating the substrate of each example and the supporting white board for measuring the visible light reflectance ρ0. The prepared laminate was placed in the reflectance measurement sample holder of the integrating sphere unit so that the measurement light was incident on the substrate, and the visible light reflectance ρ0 of the laminate was measured in the same manner as above. x obtained.

[0159] The visible light reflectance ρ0 of the obtained support white board and the visible light reflectance ρ of the laminate x From the calculated internal absorbance A1 and the thickness D1 (m) of the substrate, the parameter X (m -1 ) was calculated. Equation (1) A1= -log 10 {(ρ x / ρ0) 0.5} Equation (2) X = A1 / D1 Table 1 below shows the internal absorbance A1 and parameter X of each substrate.

[0160] [Touch sensor evaluation] (Fabrication of evaluation touch panel) In order to eliminate the influence of individual differences between display elements and to strictly compare samples, a simulated touch panel was fabricated by the following method.

[0161] - Fabrication of composite materials - The following members including the touch sensors obtained in each of the Examples and Comparative Examples were bonded together to prepare composite members in which the members were arranged in the following order. Glass substrate (thickness 0.4 mm) Transparent adhesive layer (3M Japan 8146-3, thickness 75 μm) Touch sensor Transparent adhesive layer (3M Japan Ltd. 8146-6, thickness 150 μm) Triacetylcellulose (TAC) film (Fujifilm Corporation, thickness 40 μm)

[0162] -Creating a mock panel- A simulated panel was prepared by dropping 0.7 mL of matching oil (Newton's ring prevention agent "HM-30" manufactured by Koyo Chemical Industry Co., Ltd.) onto the display surface of a 14-inch organic EL panel (manufactured by Samsung Display Co., Ltd., model number "ATNA40CU03"), and then placing the composite member for evaluation on top of it so that the TAC film faced the organic EL panel and so that no air was trapped inside. Furthermore, after confirming that the evaluation values ​​for the simulated panel roughly match those for actual touch panel products (for example, a touch panel having a component configuration with glass, transparent adhesive, touch sensor, transparent adhesive, and organic EL panel in that order), and that there is no difference in the evaluation hierarchy, the above evaluation method was adopted as an evaluation method for the implemented form.

[0163] (Measurement of black display luminance) A simulated panel was placed in a windowless darkroom with the display surface facing vertically upward. An 80mm x 80mm square image of black ((R, G, B) = (0, 0, 0)) was displayed in the center of the screen of the simulated panel, and a white image ((R, G, B) = (255, 255, 255)) was displayed all around the black image. A cylinder (60mm diameter, 350mm length) made by rolling up black cardboard was placed vertically in the center of the screen of the simulated panel so that the center of the black image on the simulated panel and the central axis of the cylinder were approximately aligned. A spectroradiometer (CS-3000HDR, manufactured by Konica Minolta, Inc.) was attached to the end of the cylinder, and the luminance of the image displayed by the simulated panel was measured under the following measurement conditions. This was taken as the black display luminance. - Luminance meter measurement conditions - Speed ​​mode: FAST Dark Setting: Standard Aperture angle: 1deg

[0164] (Measurement of white display luminance) The brightness was measured in the same manner as for measuring the black display brightness, except that the image displayed on the simulated panel was an entirely white image ((R, G, B) = (255, 255, 255)), and this was taken as the white display brightness. In addition, when the brightness was measured in the same manner as above, except that an image in which the black and white of the image displayed in the measurement of the black display brightness was inverted, the brightness value obtained was the same as the white display brightness measured when a white image was displayed on the entire screen.

[0165] The measurement results of the black display luminance and white display luminance of the touch sensors fabricated in each of the examples and comparative examples are shown in Table 1 below. When measuring the OLED panel alone without laminating the composite material, the black display luminance is 0.2 mCd / m 2 , White display brightness = 415 Cd / m 2 The contrast ratio (ratio of white display brightness to black display brightness) was 2.06 million.

[0166] (Contrast evaluation) From the measurement results of the black display luminance and the white display luminance obtained above, the contrast between the black display and the white display when black and white display was performed was evaluated. Specifically, the ratio of the measured value of the white display luminance to the measured value of the black display luminance was calculated as the contrast ratio, and the contrast of each touch sensor was evaluated from the obtained contrast ratio based on the following criteria.

[0167] -Contrast evaluation criteria- "A": Contrast ratio of 1.5 million or more. "B": Contrast ratio is between 1 million and 1.5 million. "C": Contrast ratio is between 500,000 and 1,000,000. "D": Contrast ratio is less than 500,000.

[0168] (Evaluation of white display luminance reduction suppression performance) From the measurement results of the white display luminance obtained above, the performance of the touch sensor in suppressing a decrease in the white display luminance was evaluated. Specifically, the loss rate of white display luminance due to the touch sensor was calculated using the formula below from the measurement results of the white display luminance of each simulated panel and the measurement results of the white display luminance when the organic EL panel was used alone, and the performance of each touch sensor in suppressing the decrease in white display luminance was evaluated from the obtained loss rate based on the following criteria. White display brightness loss rate (%) = (1 - simulated panel white display brightness / OLED panel white display brightness) x 100

[0169] -Evaluation criteria for suppressing the decrease in white display brightness- "A": White display brightness loss rate is 2% or less. "B": White display brightness loss rate is more than 2% and less than 4%. "C": White display brightness loss rate is over 4% and 6% or less. "D": White display brightness loss rate exceeds 6%.

[0170] The table below shows the performance of the substrate of each touch sensor, the measurement results, and the evaluation results. The criteria for determining whether a touch sensor can achieve a high-brightness, high-contrast touch panel are as follows: if all ratings are A to C, it is at an acceptable level; if all ratings are A or B, it is at a good level; and if all ratings are A, it is at an excellent level.

[0171] [Table 1]

[0172] [Table 2]

[0173] From the results in Tables 1 and 2, it was confirmed that the touch sensors of Examples 1 to 7 have excellent contrast between black and white displays when applied to a display device to display black and white, and also have excellent performance in suppressing a decrease in brightness of the white display. On the other hand, if the parameter X is 30m -1 The touch sensors of Comparative Examples 1, 2, and 5, which had a brightness of less than 100 s, maintained high white display brightness, but the improvement in contrast was insufficient. Furthermore, the touch sensors of Comparative Examples 3 and 4, which had an internal absorbance A1 of more than 0.03, had a large loss in white display luminance and were insufficient in terms of performance in suppressing a decrease in luminance.

[0174] From a comparison of Examples 1, 2 and 5, it was confirmed that even if the parameter X was the same, the thinner the substrate, the better the contrast between black and white display when black and white display was performed. Furthermore, a comparison of Examples 4, 6, and 7 confirmed that even if the internal absorbance A1 was the same, the thinner the substrate, the better the contrast between the black display and the white display when black and white display was performed. From these comparisons, it was confirmed that when the thickness of the substrate is less than 110 μm, the loss of the white display remains small and the contrast between the black display and the white display is excellent when black and white display is performed.

[0175] [Example 8] According to the method for producing the substrate 1 described in Example 1, a biaxially stretched PET film having an undercoat layer on both main surfaces, a thickness D2 of 40 μm, and containing titanium oxynitride as the visible light absorbing material α was produced, and named as the optical member 1. The refractive index of the optical member 1 was 1.58.

[0176] Next, the following members including the optical member 1 were bonded together to prepare a composite member 8 in which the members were arranged in the following order: Optical component 1 Transparent adhesive layer (3M Japan 8146-3, thickness 75 μm) Triacetylcellulose (TAC) film (Fujifilm Corporation, thickness 40 μm)

[0177] 0.7 mL of matching oil (Newton's ring prevention agent "HM-30" manufactured by Koyo Chemical Industry Co., Ltd.) was dropped onto the display surface of a 14-inch organic EL panel (manufactured by Samsung Display Co., Ltd., model number "ATNA40CU03"), and composite member 8 was placed on top of it so that the TAC film faced the organic EL panel and so as to prevent air from entering, thereby producing image display device 8 of Example 8.

[0178] [Examples 9 to 16, Comparative Example 7] Optical members 2 to 9 and C2 of Examples 9 to 16 and Comparative Example 7 were produced in accordance with the production method for substrate 1 described in Example 1, except that the mixing ratio of the pellets and master pellets was adjusted so that the content of visible light absorber α would be the amount shown in Table 3 described later, and / or the thickness of the unstretched PET film was adjusted so that the thickness D2 of the optical member would be the thickness shown in Table 3 described later. In addition, a biaxially stretched PET film was prepared according to the method for preparing the substrate 1 described in Comparative Example 1, and used as the optical member C1 of Comparative Example 6.

[0179] Composite members 9 to 16 and C6 to C7 were prepared in the same manner as in Example 8, except that optical members 2 to 9 and C1 to C2 were used instead of optical member 1. Image display devices 9 to 16 and C6 to C7 were prepared using the prepared composite members 9 to 16 and C6 to C7.

[0180] The thickness D2 of each optical member was measured in the same manner as in [Measurement of thickness of substrate] above. In addition, the internal absorbance A2 and parameter X2 of each optical member were measured using the same method as in the above [Measurement and evaluation of optical performance of substrate]. The refractive index of the optical member was measured by the Abbe method using a precision refractometer KPR-30A (manufactured by Shimadzu Corporation). Table 3, which will be described later, shows the content of the visible light absorbing material α, the thickness D2, the refractive index, the internal absorbance A2, and the parameter X2 for each optical member.

[0181] [Evaluation of image display devices] Except for using one of image display devices 8 to 16 and C6 to C7 instead of the simulated panel, the black display luminance and white display luminance were measured for each image display device in the same manner as in [Evaluation of touch sensor] above, and the contrast between the black display and the white display when black and white display was performed, and the ability of the optical components to suppress a decrease in white display luminance were evaluated.

[0182] The following table shows the performance of each optical member, the measurement results of each luminance, and the evaluation results for each image display device. The criteria for determining whether an image display device has high brightness and high contrast are as follows: if all ratings are A to C, it is at an acceptable level; if all ratings are A or B, it is at a good level; and if all ratings are A, it is at an excellent level.

[0183] [Table 3]

[0184] As shown in the above table, it was confirmed that the image display devices of Examples 8 to 16 of the present invention have excellent contrast between black and white display when black and white display is performed, and also have excellent performance in suppressing a decrease in white display brightness. On the other hand, parameter X2 is 30m -1 The image display device of Comparative Example 6, which has a brightness of less than 1000 saturations, maintained a high white display brightness, but the improvement in contrast was insufficient. Furthermore, the image display device of Comparative Example 7, which had an internal absorbance A2 of more than 0.03, had a large loss in white display luminance and was insufficient in terms of performance in suppressing a decrease in luminance.

[0185] From a comparison with Examples 8 to 11, the internal absorbance A2 is 0.003 to 0.010, and the parameter X2 is 80 to 250 m -1 Furthermore, it was confirmed that when the thickness D2 of the substrate is 40 to 60 μm, the performance of suppressing the decrease in the contrast between black and white displays / white display brightness during black and white display is more excellent.

[0186] [Example 17] The touch sensor 1 produced in Example 1 and the following components including the optical member 1 produced in Example 8 were bonded together to produce a composite member 17 in which the components were arranged in the following order: Optical component 1 Transparent adhesive layer (3M Japan 8146-3, thickness 75 μm) Touch sensor 1 Transparent adhesive layer (3M Japan Ltd. 8146-6, thickness 150 μm) Triacetylcellulose (TAC) film (Fujifilm Corporation, thickness 40 μm)

[0187] An image display device 17 of Example 17 was produced in the same manner as in Example 8, except that a composite member 17 was used instead of the composite member 8.

[0188] [Examples 18 to 25] Composite members 18 to 25 were prepared in the same manner as in Example 17, except that optical members 2 to 9 were used instead of optical member 1, and image display devices 18 to 25 were prepared using the prepared composite members 18 to 25.

[0189] Except for using one of image display devices 17 to 25 instead of the simulated panel, the black display luminance and white display luminance were measured for each image display device in the same manner as in [Evaluation of Touch Sensor] above, and the contrast between the black display and the white display when black and white display was performed, and the ability of the optical components to suppress a decrease in white display luminance were evaluated.

[0190] The following table shows the measurement results of each luminance and the evaluation results for each image display device. The criteria for determining whether an image display device has high brightness and high contrast are as follows: if all ratings are A to C, it is at an acceptable level; if all ratings are A or B, it is at a good level; and if all ratings are A, it is at an excellent level.

[0191] [Table 4]

[0192] As shown in the above table, it was confirmed that the image display devices of Examples 17 to 25 of the present invention have excellent contrast between black and white display when black and white display is performed, and also have excellent performance in suppressing a decrease in white display luminance. [Explanation of symbols]

[0193] 1,201 Base material 1a,1b,40a,201a,201b,240a Surface 2,202 Support 3,203 primer layer 4,130,230 Adhesive layer 10,210 Touch Sensor 11,21,211,221 Detection electrode 12,22 Electrode connection terminal 13,23 Peripheral wiring 14,24 External connection terminal 30,120,220 image display element 30a,120a,220a Display surface 40 protective layer 51 Conductive thin wire 52 Opening 100,110,200 Image display device 120a Display surface 140,240 Optical components R1 detection area R2 surrounding area

Claims

1. An image display device having an image display element having a display area and a non-display area, and an optical member covering the display area, The refractive index of the optical member is 1.55 or more, the optical member includes a visible light absorbing material α, The optical member is tested according to the following test X. ２ The internal absorbance A calculated from ２ is 0.0004 to 0.03, and the parameter X ２ 30 to 3000m －１ An image display device. Test X ２ : Visible light reflectance ρ of the supporting white plate according to the method described in JIS R 3106:2019 ０ According to the method described in JIS R 3106:2019, a measurement light is incident on the optical member side of a laminate obtained by laminating the supporting white plate and the optical member, and a visible light reflectance ρ ２ get. The visible light reflectance ρ ０ and the visible light reflectance ρ ２ From the following formula (2-1), the internal absorbance A of the optical member is calculated. ２ The calculated internal absorbance A ２ and the thickness D of the optical member ２ From (m), the parameter X is calculated using the following equation (2-2): ２ (m －１ ) is calculated. Formula (2-1) A ２ = -log １０ {(ρ ｘ / ρ ０ ) ０．５} Formula (2-2) X ２ = A ２ / D ２

2. The thickness D of the optical member ２ 2. The image display device according to claim 1, wherein the thickness is 20 to 200 μm.

3. the visible light absorber α is a black pigment, 3. The image display device according to claim 1, wherein the content of the black pigment is 10 to 500 ppm by mass with respect to the total mass of the optical member.

4. a touch sensor disposed between the image display element and the optical member; The touch sensor has a substrate and a detection electrode disposed on at least one surface side of the substrate, the substrate comprises a visible light absorbing material β, The substrate has an internal absorbance A calculated by the following test X. １ is 0.0004 to 0.03, and the parameter X is 30 to 3000 m －１ 3. The image display device according to claim 1, wherein: Test X: Visible light reflectance ρ of the supporting white plate measured by the method described in JIS R 3106:2019 ０ According to the method described in JIS R 3106:2019, a measurement light is incident on the substrate side of the laminate formed by laminating the support white plate and the substrate, and the visible light reflectance ρ ｘ get. The visible light reflectance ρ ０ and the visible light reflectance ρ ｘ From the following formula (1), the internal absorbance A of the substrate is calculated. １ The calculated internal absorbance A １ and the thickness D of the substrate １ (m) to obtain the parameter X(m －１ ) is calculated. formula (1) A １ = -log １０ {(r) ｘ / r ０ ) ０．５ } Formula (2) X = A １ / D １

5. The thickness D of the substrate １ 5. The image display device according to claim 4, wherein the thickness is 10 to 110 μm.

6. the visible light absorber β is a black pigment, 5. The image display device according to claim 4, wherein the content of the black pigment is 10 to 500 ppm by mass with respect to the total mass of the substrate.

7. Further having a pressure-sensitive adhesive layer, The image display device according to claim 4 , wherein the image display element, the adhesive layer, and the touch sensor are arranged in this order.

8. 3. The image display device according to claim 1, wherein the image display element is an organic electroluminescence display element.

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