Optical laminate for OLED display device

Abstract

The present invention provides an optical laminate used in an OLED display device that does not use a polarizing plate and is not susceptible to color shift, interference unevenness, and white blur that occur when viewed from an inclined direction. Provided is an optical laminate used in an OLED display device in which only an optical element having a degree of polarization of 95% or less is laminated on the viewing side of an OLED element. The optical element has at least an antireflection layer and an adhesive layer having light scattering properties. In the reflectance spectrum of the OLED display device, the maximum reflectance in the wavelength range of 380 nm to 455 nm is Rp1, the maximum reflectance in the wavelength range of 460 nm to 530 nm is Rp2, the reflectance of the antireflection layer at the wavelength of Rp1 is Rf1, the reflectance of the antireflection layer at the wavelength of Rp2 is Rf2, the reflectance of the antireflection layer at the wavelength of Rp2 is Rf1, and the reflectance of the antireflection layer at the wavelength of Rp2 is Rf2. When the haze value of the adhesive layer having light scattering properties is H%, the value of H / {[Rf1 / Rp1] + [Rf2 / Rp2]} is 200 or more.

Description

Technical Field

[0001] The present invention relates to an optical laminate for an OLED display device, and more particularly to an optical laminate for use in an OLED display device that does not use a polarizing plate. Background Art

[0002] Compared to liquid crystal displays (LCDs), OLED (organic light-emitting diode) displays offer advantages in display performance, including high visual recognition, low viewing angle dependence, and fast response speed. Furthermore, OLED displays lack a backlight, facilitating thinning and enabling flexible, bendable, or foldable devices.

[0003] OLED display devices typically include an OLED element in which an anode, an OLED layer including a light-emitting layer, and a cathode are stacked in this order. Because the electrodes (anode or cathode) of OLED elements are made of transparent conductive materials with high refractive indexes, such as ITO, or metal materials with high reflectivity, external light is reflected by the electrodes, resulting in reduced contrast and reflections caused by internal reflections, which can sometimes degrade the display performance of the OLED display device.

[0004] To suppress the adverse effects of external light reflection, a proposal has been made to place a polarizing plate and a circularly polarizing plate, such as a λ / 4 plate, on the viewing side of an OLED display device (e.g., Patent Document 1). Such a circularly polarizing plate also blocks ultraviolet light contained in external light, preventing degradation of the OLED element caused by ultraviolet rays. Furthermore, by utilizing the mechanical properties of the circularly polarizing plate itself, it also absorbs external impact, preventing damage to the OLED display device.

[0005] However, when using a circular polarizer, the light utilization efficiency (i.e., light collection rate) deteriorates due to absorption by the polarizer, resulting in lower brightness. Increasing the luminous intensity of the OLED element to achieve the desired brightness increases power consumption and shortens the lifespan of the OLED element. Furthermore, when the polarizer includes an adhesive layer for bonding, the thickness can reach approximately 0.15 mm, hindering the thinning of the OLED display device. Furthermore, since circular polarizers are expensive, there is also the problem of increased manufacturing costs.

[0006] As an alternative to circular polarizers, the following method has been proposed: for an OLED element, a color filter is arranged on its visual identification side, and the color filter of the same color as the luminous color of the OLED layer is aligned so as to face the OLED element, thereby preventing external light reflection and improving the luminous intensity of the OLED element (for example, Patent Document 2).

[0007] As one form of OLED display device, an OLED display device having a microcavity (also known as multi-reflection interference, optical resonator, or microresonator) structure is known. According to an OLED display device having a microcavity structure, the spectrum of light extracted to the outside becomes steeper and more intense, thereby improving brightness and color purity (for example, Patent Document 3).

[0008] In OLED display devices, various optical elements such as adhesive layers, substrates such as plastic and thin glass, and hard coat layers are laminated to provide functions such as surface protection and flexibility on the viewing side of the OLED element.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-332068

[0012] Patent Document 2: Japanese Patent Application Publication No. 2018-112715

[0013] Patent Document 3: Japanese Patent Application Laid-Open No. 2015-207377 Summary of the Invention

[0014] Problems to be solved by the invention

[0015] As an alternative to circular polarizing plates, a method is used in which a color filter is arranged on the visual recognition side of an OLED element and aligned so that a color filter of the same color as the luminous color of the OLED layer faces the OLED element, thereby preventing external light reflection while improving the luminous intensity of the OLED element. However, due to the regular two-dimensional structure of the color filter, interference unevenness (interference muria) of the reflected light sometimes occurs, thereby impairing the visual recognition of the OLED display device.

[0016] OLED displays with microcavity structures also suffer from a strong viewing angle dependency (narrow viewing angle). More specifically, OLED displays with microcavity structures can experience a sharp drop in brightness or noticeable shifts in hue depending on viewing angle. As a result, when viewing an image from an oblique angle, a color shift may occur, causing the image to appear different from the intended color.

[0017] In order to suppress the above-mentioned interference unevenness and color shift, laminating a pressure-sensitive adhesive layer having light-scattering properties is effective. However, the pressure-sensitive adhesive layer having light-scattering properties scatters and reflects external light, thereby causing a problem called white blur, in which the displayed image appears whitish.

[0018] Therefore, an object of the present invention is to provide an optical laminate for an OLED display device that is less likely to cause color shift, interference unevenness, and white blurring when the OLED display device is viewed from an oblique direction without using a polarizing plate.

[0019] Means used to solve problems

[0020] The present inventors conducted intensive research to achieve the above-mentioned objectives and found that by stacking a specific optical laminate in an OLED display device that does not use a polarizing plate, it is possible to provide an OLED display device that is less susceptible to color shift, interference unevenness, and white blur when viewed from an oblique direction and has excellent visual recognition, thereby completing the present invention.

[0021] That is, the present invention provides an optical laminate for an OLED display device, the optical laminate for an OLED display device being used for an OLED display device in which only an optical element having a polarization degree of 95% or less is laminated on a visual recognition side of an OLED element, wherein the optical element comprises at least an antireflection layer and an adhesive layer, at least one of the adhesive layers has a light scattering property, and when, in a reflectance spectrum of the OLED display device in a state where the optical laminate for the OLED display device is not laminated, the maximum reflectance within a wavelength range of 380 nm to 455 nm is defined as Rp1, and the maximum reflectance within a wavelength range of 460 nm to 530 nm is defined as Rp2, the reflectance of the antireflection layer at the wavelength of Rp1 is defined as Rf1, and the reflectance of the antireflection layer at the wavelength of Rp2 is defined as Rf2, and the haze value of the adhesive layer having a light scattering property is defined as H%, the value of H / {[Rf1 / Rp1]+[Rf2 / Rp2]} is 200 or greater.

[0022] The water contact angle of the antireflection layer is preferably 100° or greater.

[0023] The water contact angle of the antireflection layer after an eraser test is preferably 90° or greater.

[0024] The antireflection layer is preferably made of an inorganic substance.

[0025] Preferably: the adhesive layer with light scattering properties is arranged on at least one side of the resin layer, and the adhesive layer with light scattering properties contains light scattering particles dispersed in the adhesive layer. When the refractive index of the resin layer is set to n1, the refractive index of the adhesive of the adhesive layer with light scattering properties is set to n2, and the refractive index of the light scattering particles is set to n3, n1>n2>n3 is satisfied.

[0026] The volume average particle size of the light-scattering fine particles is preferably 1 μm to 5 μm.

[0027] The light-scattering fine particles are preferably silicone resin.

[0028] The haze value H of the pressure-sensitive adhesive layer having light scattering properties is preferably 20% to 90%.

[0029] Effects of the Invention

[0030] An OLED display device in which the optical laminate for an OLED display device of the present invention is laminated on the viewing side of an OLED element is less likely to cause color shift, interference unevenness, or white blur and has excellent visibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display panel according to the present invention.

[0032] Figure 2 This is a schematic cross-sectional view showing one embodiment of an OLED display device in which the optical laminate of the present invention is stacked.

[0033] Figure 3 This is a schematic cross-sectional view showing one embodiment of an OLED display device in which the optical laminate of the present invention is stacked.

[0034] Figure 4 This is a schematic cross-sectional view showing one embodiment of an OLED display device in which the optical laminate of the present invention is stacked.

[0035] Figure 5 This is a schematic cross-sectional view showing one embodiment of an OLED display device in which the optical laminate of the present invention is stacked.

[0036] Figure 6 This is a schematic cross-sectional view showing one embodiment of an OLED display device in which the optical laminate of the present invention is stacked.

[0037] Figure 7 This is a schematic cross-sectional view showing one embodiment of an OLED display device in which the optical laminate of the present invention is stacked.

[0038] Figure 8 This is a schematic cross-sectional view showing one embodiment of an OLED display device in which the optical laminate of the present invention is stacked.

[0039] Figure 9 This is a schematic cross-sectional view showing one embodiment of an OLED display device in which the optical laminate of the present invention is stacked.

[0040] Figure 10 This is a schematic cross-sectional view showing one embodiment of an OLED display device in which the optical laminate of the present invention is stacked. DETAILED DESCRIPTION

[0041] The present invention provides an optical laminate for use in an OLED display device (optical laminate for an OLED display device), wherein only an optical element having a polarization degree of 95% or less is laminated on the viewing side of an OLED element. The optical laminate for an OLED display device of the present invention is sometimes referred to as the "optical laminate of the present invention," an OLED display device using the optical laminate of the present invention is sometimes referred to as the "OLED display device of the present invention," and an optical element constituting the optical laminate of the present invention is sometimes referred to as the "optical element of the present invention."

[0042] The OLED display device of the present invention has an essential structure comprising an OLED display panel including an OLED element in which an anode, an OLED layer including a light-emitting layer, and a cathode are stacked in this order, and the optical laminate of the present invention is stacked on the viewing side of the OLED element. The OLED display panel constituting the OLED display device of the present invention is sometimes referred to as the "OLED display panel of the present invention."

[0043] The OLED display device of the present invention is only stacked with optical elements with a polarization degree of 95% or less on the visual recognition side of the OLED element in the OLED display panel. “Only stacked with optical elements with a polarization degree of 95% or less on the visual recognition side of the OLED element” means that the optical elements on the visual recognition side of the OLED element do not include optical elements with a polarization degree greater than 95%. There are no special restrictions on “optical elements with a polarization degree greater than 95%”, including polarizing plates such as linear polarizing plates, 1 / 4 phase difference plates, 1 / 2 phase difference plates, circular polarizing plates, and reflective polarizing plates. That is, the OLED display device of the present invention is an OLED display device that does not include a polarizing plate on the visual recognition side of the OLED element.

[0044] The polarization degree is determined by the following formula based on the parallel transmittance Tp and the cross transmittance Tc measured using an ultraviolet-visible spectrophotometer and corrected for visibility.

[0045] Polarization degree (%) = {(Tp-Tc) / (Tp+Tc)}1 / 2×100

[0046] The OLED display device of the present invention does not include a polarizing plate on the viewing side of the OLED element. This prevents the polarizing plate from absorbing light emitted from the OLED element, thereby increasing light collection efficiency, saving power, and extending the life of the OLED element. Furthermore, by eliminating the polarizing plate, the device can be thinner and reduce manufacturing costs.

[0047] The optical element of the present invention comprises at least an antireflection layer and an adhesive layer. The optical element of the present invention preferably comprises an antireflection layer, which reduces the occurrence of interference unevenness in the OLED display device of the present invention and improves visual recognition. Furthermore, the adhesive layer constituting the optical laminate of the present invention has light scattering properties, thereby suppressing color shift and interference unevenness caused by the OLED display device of the present invention, and improving visual recognition.

[0048] In the optical laminate of the present invention, in the reflectance spectrum of the OLED display device in a state where the optical laminate of the present invention is not laminated, the maximum reflectance within the wavelength range of 380 nm to 455 nm is defined as Rp1, and the maximum reflectance within the wavelength range of 460 nm to 530 nm is defined as Rp2; the reflectance of the antireflection layer at the wavelength (WL1) of Rp1 is defined as Rf1, and the reflectance of the antireflection layer at the wavelength (WL2) of Rp2 is defined as Rf2; and the haze value of the pressure-sensitive adhesive layer having light-scattering properties is defined as H%, the value of H / {[Rf1 / Rp1]+[Rf2 / Rp2]} is 200 or more, preferably 300 or more, and more preferably 400 or more. By having such a configuration, white blurring caused by the OLED display device of the present invention can be suppressed, and excellent visual recognition can be achieved.

[0049] In another embodiment of the OLED display device of the present invention, a color filter is preferably disposed on the visual recognition side of the OLED element, and only the optical element of this embodiment is laminated on the visual recognition side of the color filter. The optical element of this embodiment preferably has at least an adhesive layer, at least one layer of the adhesive layer has light scattering properties, and the distance (d) between the adhesive layer having light scattering properties and the color filter is 700 μm or less. The distance between the adhesive layer having light scattering properties and the color filter is 700 μm or less, which is suitable in the following aspects: even if a light scattering layer is laminated to suppress color shift and interference unevenness caused by the OLED display device of this embodiment, image blur is unlikely to occur, and visual recognition is excellent.

[0050] In another embodiment of the OLED display device of the present invention, the optical element of this embodiment preferably has at least an anti-glare layer. The optical element of this embodiment having an anti-glare layer is suitable for suppressing color shift and interference unevenness caused by the OLED display device of this embodiment, thereby improving visual recognition.

[0051] In another embodiment of the OLED display device of the present invention, the optical element of this embodiment preferably includes at least a glass layer and a resin layer, and the glass layer and the resin layer are bonded together via an adhesive layer. In the optical laminate of this embodiment, bonding the glass layer and the resin layer together via the adhesive layer improves the impact resistance of the OLED display device of this embodiment, and is therefore suitable.

[0052] In another embodiment of the OLED display device of the present invention, the optical element of this embodiment preferably comprises at least a transparent polyimide layer and a hard coat layer. The optical element of this embodiment having a transparent polyimide layer and a hard coat layer improves the impact resistance of the OLED display device of this embodiment, and is therefore suitable. Each component is described below.

[0053] (OLED display panel)

[0054] The OLED display panel used in the OLED display device of the present invention includes an OLED element in which an anode, an OLED layer including a light-emitting layer, and a cathode are stacked in this order as an essential component. The optical laminate of the present invention is stacked on the viewing side of the OLED element of the OLED display panel.

[0055] Hereinafter, an embodiment of an OLED display panel constituting the OLED display device of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to this embodiment. Figure 1 FIG. 1 is a schematic cross-sectional view showing an embodiment of an OLED display panel according to the present invention.

[0056] like Figure 1 As shown, the OLED display panel 100 includes: a red OLED element 12R in which a transparent electrode 11a, a red OLED layer 10R that emits red light, and a back electrode 11b are stacked in this order; a green OLED element 12G in which a transparent electrode 11a, a green OLED layer 10G that emits green light, and a back electrode 11b are stacked in this order; and a blue OLED element 12B in which a transparent electrode 11a, a blue OLED layer 10B that emits blue light, and a back electrode 11b are stacked in this order. The OLED elements 12R, 12G, and 12B of various colors are sequentially arranged on a substrate 13. A TFT (thin film transistor) layer 14 is formed on the surface of the substrate 13 where the OLED elements are arranged, and is connected to the back electrodes 11b of the OLED elements 12R, 12G, and 12B of various colors.

[0057] exist Figure 1 In the OLED display panel 100, on the visual recognition side of each of the multiple color OLED elements 12R, 12G, and 12B ( Figure 1A color filter 15 is provided (the upper side is in the center). The color filter 15 includes a red coloring layer 15R, a green coloring layer 15G, and a blue coloring layer 15B, and a black matrix layer 16 is provided between the coloring layers.

[0058] exist Figure 1 In the color filter 15 , the red colored layer 15R, the green colored layer 15G, and the blue colored layer 15B are arranged to face the red OLED element 12R, the green OLED element 12G, and the blue OLED element 12B, respectively.

[0059] The transparent electrode 11a is either a cathode or an anode, but is usually a cathode. Transparent conductive materials such as ITO (indium tin oxide), indium oxide, IZO (indium zinc oxide), SnO2, and ZnO are used as the forming material of the transparent electrode 11a.

[0060] The back electrode 11b functions as a counter electrode for the transparent electrode 11a. The back electrode 11b can be either an anode or a cathode, but is typically provided on the substrate 13 as an anode. Examples of materials for forming the back electrode 11b include metals such as gold, silver, and chromium. Therefore, the back electrode 11b can reflect light.

[0061] A bonding layer 17 is provided between the substrate 13 and the color filter 15. The bonding layer 17 is translucent. The bonding layer 17 can be made of any material commonly used in OLED display devices, such as a photosensitive polyimide resin or a thermosetting resin.

[0062] OLED display panel 100 Figure 1 In addition to the structures shown, the OLED display panel may have structures such as a hole injection layer, a hole transport layer, an electron transport layer, a sealing layer, a touch sensor panel, etc. (not shown).

[0063] Figure 1 The OLED display panel is characterized in that a color filter 15 is disposed on each of the OLED elements 12R, 12G, and 12B in a manner opposite to the colored layers 15R, 15G, and 15B of the same color. Figure 1 As shown, white external light W, for example, passes through the red coloring layer 15R, further passes through the transparent electrode 11a and the red OLED layer 10R that emits red light and is reflected at the back electrode 11b, passes through the red OLED layer 10R, the transparent electrode 11a and the red coloring layer 15R again, and then the reflected light G enters the observer's eyes.

[0064] The external light W is absorbed by the red coloring layer 15R, which absorbs green and blue light, so the light intensity is reduced to 1 / 3. In addition, the reflected light G passes through the red coloring layer 15R and the red OLED layer 10R again, thereby causing attenuation. In addition, the reflected light G is red, so it can enhance the red light emitted from the OLED layer 10R. The same is true when the external light W is incident on the green coloring layer 15G and the blue coloring layer 15B, which can enhance the green light and blue light respectively. Therefore, by using color filters in the OLED display panel, even without using a circular polarizer to prevent reflection, the reflection of external light can be greatly suppressed, and the luminous intensity of the OLED element can be improved.

[0065] However, color filters are generally prone to interference unevenness caused by a regular two-dimensional structure. In addition, color filters are prone to reflection at the interface, which reduces the light collection rate of light emitted from the OLED element. In addition, compared with the case of using a circular polarizing plate, color filters have insufficient ultraviolet absorption function, and OLED elements are prone to deterioration over time due to ultraviolet rays contained in external light (i.e., low weather resistance). In addition, compared with the case of using a circular polarizing plate, color filters have insufficient impact absorption function.

[0066] The OLED display panel 100 of this embodiment also has a microcavity structure. Light generated by the OLED layers 10R, 10G, and 10B is emitted to the outside through the transparent electrode 11a. This emitted light consists of two components: "direct light," which is emitted directly from the OLED layers 10R, 10G, and 10B toward the transparent electrode 11a, and "reflected light," which is emitted from the OLED layers 10R, 10G, and 10B toward the back electrode 11b, reflected by the back electrode 11b, and then emitted toward the transparent electrode 11a. Specifically, a first optical path C1 is formed in which a portion of the light emitted from the OLED layers 10R, 10G, and 10B does not travel toward the back electrode 11b but instead travels toward the transparent electrode 11a and is emitted externally through the transparent electrode 11a. A second optical path C2 is formed in which the remaining portion of the light emitted from the OLED layers 10R, 10G, and 10B travels toward the back electrode 11b, is reflected by the back electrode 11b, and then passes through the OLED layers 10R, 10G, 10B and the transparent electrode 11a and is emitted externally. The thicknesses of the OLED layers 10R, 10G, and 10B differ so that the interference between the direct light and the reflected light enhances the light components corresponding to each color. Specifically, the thicknesses of the OLED layers 10R, 10G, and 10B differ so that the optical path lengths between the back electrode (positive electrode) 11b and the transparent electrode (negative electrode) 11a coincide with the peak wavelengths of the EL spectra for each of the red, green, and blue colors, thereby extracting the strongest light from each color. Specifically, the short-wavelength blue OLED layer 10B is designed to be thin, while the long-wavelength red OLED layer 10R is designed to be thick. When light generated in the OLED layer is repeatedly reflected between the positive and negative electrodes, only light with wavelengths that match the optical path length resonates and intensifies, while light with other wavelengths that do not match the optical path length is weakened. This results in a steeper spectrum of light extracted to the outside, with higher intensity, improving brightness and color purity.

[0067] While OLED display panels with a microcavity structure can achieve excellent results such as improved brightness and color purity, their steep spectrum can also lead to a problem of strong viewing angle dependence (narrow viewing angle). Consequently, when viewing an image from an oblique angle, a color shift may occur, causing the color to appear different from the intended color.

[0068] (Optical element of the present invention)

[0069] The optical element of the present invention is an optical element laminated on the viewing side of an OLED display device, and includes at least one layer selected from the group consisting of an adhesive layer, an adhesive layer, a resin layer, a glass layer, a hard coat layer, an antireflection layer, an antiglare layer, an intermediate layer (a compatibilizing layer), an impact-absorbing layer, and an antistatic layer. However, the optical element of the present invention does not include an optical element having a polarization degree greater than 95%, such as a polarizing plate.

[0070] (Adhesive layer)

[0071] The adhesive layer is a layer having adhesiveness at room temperature and adhering to an adherend with light pressure. Even when the adherend affixed to the adhesive layer is peeled off, the adhesive layer maintains practical adhesive strength.

[0072] From the perspective of effectively reducing color shift and interference unevenness in OLED display devices, the adhesive layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "adhesive layer of the present invention") preferably has light scattering properties (a function of scattering light). When the adhesive layer of the present invention has light scattering properties, it preferably contains light scattering fine particles dispersed in the adhesive layer.

[0073] In the case where the OLED display device of the present invention includes a color filter on the viewing side and the adhesive layer has light-scattering properties, the distance (d) between the light-scattering adhesive layer and the color filter is preferably 700 μm or less from the perspective of reducing color shift and interference unevenness in the OLED display device and suppressing image blurring in the OLED display device caused by light scattering. From the perspective of suppressing image blurring in the OLED display device caused by light scattering, the distance between the light-scattering adhesive layer and the color filter is more preferably 600 μm or less, and even more preferably 500 μm or less. Most preferably, the light-scattering adhesive layer is in direct contact with the color filter.

[0074] The distance between the adhesive layer having light-scattering properties and the color filter represents the distance (μm) between the surface of the adhesive layer in the color filter direction and the surface of the color filter in the adhesive layer direction. When other layers are stacked between the adhesive layer having light-scattering properties and the color filter, it corresponds to the thickness (μm) of the other layers (the total thickness in the case of two or more layers).

[0075] The haze value (H) of the adhesive layer of the present invention is not particularly limited. However, from the perspective of effectively reducing color shift and interference unevenness in OLED displays, it is preferably 20% or greater, more preferably 30% or greater, even more preferably 40% or greater, and particularly preferably 50% or greater. Furthermore, from the perspective of suppressing image blur in OLED displays and displaying high-definition images, the haze value of the adhesive layer of the present invention is preferably 90% or less, more preferably 80% or less, and even more preferably 70% or less.

[0076] The total light transmittance of the adhesive layer of the present invention is not particularly limited. From the perspective of ensuring the brightness of the OLED display device, it is preferably 60% or higher, more preferably 70% or higher, even more preferably 80% or higher, and particularly preferably 90% or higher. Furthermore, the upper limit of the total light transmittance of the adhesive layer of the present invention is not particularly limited and may be less than 100%, or may be 99.9% or lower, or 99% or lower.

[0077] The haze value and total light transmittance of the adhesive layer of the present invention can be measured by the methods specified in JIS K7136 and JIS K7361, respectively, and can be controlled by the type and thickness of the adhesive layer, and the type and amount of light scattering fine particles described below.

[0078] From the viewpoint of effectively reducing color shift and interference unevenness in OLED display devices, the thickness (T) of the adhesive layer of the present invention is preferably 10 μm to 100 μm, more preferably 15 μm to 90 μm, and even more preferably 20 μm to 80 μm.

[0079] The light scattering particles and the adhesive in the adhesive layer have a suitable refractive index difference, giving light scattering properties to the adhesive layer. When the adhesive layer contains light scattering particles, it is preferred to give scattering properties to light. As light scattering particles, inorganic particles, polymer particles, etc. can be listed. The light scattering particles are preferably polymer particles, and particularly particles consisting of silicone resins (such as the Tospearl series manufactured by Maitu Advanced Materials Japan Co., Ltd.) have excellent dispersibility, stability and a suitable refractive index difference with the adhesive layer to the adhesive layer, and can obtain an adhesive layer with excellent scattering properties showing uniform haze in the plane, which is preferred in terms of reducing the color shift of the OLED display device and the uneven interference. The shape of the light scattering particles can be, for example, a true sphere, a flat shape, or an irregular shape. The light scattering particles can be used alone or in combination with two or more.

[0080] From the viewpoint of imparting appropriate light scattering properties to the adhesive layer, the volume average particle size of the light scattering fine particles is preferably 0.1 μm or more, more preferably 0.15 μm or more, further preferably 0.2 μm or more, further preferably 0.25 μm or more, and particularly preferably 1 μm or more. In addition, from the viewpoint of preventing the haze value from becoming too high and displaying a high-definition image, the volume average particle size of the light scattering fine particles is preferably 12 μm or less, more preferably 10 μm or less, further preferably 8 μm or less, and particularly preferably 5 μm or less. The volume average particle size can be measured, for example, using a Coulter counter.

[0081] The refractive index (n3) of the light-scattering fine particles is preferably 1.2 to 5, more preferably 1.25 to 4.5, and may be 1.3 to 4 or 1.35 to 3.

[0082] From the perspective of effectively reducing color shift and interference unevenness in OLED display devices, the absolute value of the refractive index difference between the light-scattering fine particles and the binder in the binder layer (the binder layer excluding the light-scattering fine particles) is preferably 0.001 or greater, more preferably 0.01 or greater, even more preferably 0.02 or greater, particularly preferably 0.03 or greater, and can be 0.04 or greater or 0.05 or greater. Furthermore, from the perspective of preventing excessively high haze values, suppressing image blur, and displaying high-definition images, the absolute value of the refractive index difference between the light-scattering fine particles and the binder is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less.

[0083] The refractive index (n2) of the binder is preferably 1.40 to 1.60, more preferably 1.42 to 1.55, and even more preferably 1.43 to 1.50. The refractive index of the binder can be adjusted by the type and content of the aromatic ring-containing monomer, high-refractive index organic material, and high-refractive index inorganic material described below.

[0084] From the perspective of imparting appropriate light scattering properties to the adhesive layer, the content of the light scattering fine particles in the adhesive layer is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, further preferably 0.1 parts by weight or more, and particularly preferably 0.15 parts by weight or more, relative to 100 parts by weight of the adhesive constituting the adhesive layer. Furthermore, from the perspective of preventing excessively high haze values, suppressing image blur, and achieving high-definition images, the content of the light scattering fine particles is preferably 80 parts by weight or less, more preferably 70 parts by weight or less, relative to 100 parts by weight of the adhesive constituting the adhesive layer.

[0085] The adhesive layer of the present invention (particularly when a color filter is disposed on the viewing side of the OLED element and the distance (d) between the adhesive layer of the present invention and the color filter is 700 μm or less) is not particularly limited. However, from the perspective of preventing interfacial reflection and improving the light collection efficiency of light emitted from the OLED element, a high refractive index is preferred. From the perspective of preventing interfacial reflection and improving the light collection efficiency of light emitted from the OLED element, the refractive index of the adhesive layer of the present invention is preferably 1.57 or greater, more preferably 1.575 or greater, even more preferably 1.580 or greater, particularly preferably 1.585 or greater, even more preferably 1.590 or greater, and may also be 1.595 or greater.

[0086] The adhesive constituting the adhesive layer of the present invention is not particularly limited, but acrylic adhesives are preferred from the perspectives of transparency, adhesion, weather resistance, cost, and ease of adhesive design. Specifically, the adhesive layer of the present invention is preferably an acrylic adhesive layer composed of an acrylic adhesive. These adhesives may be used alone or in combination of two or more.

[0087] The acrylic adhesive layer contains an acrylic polymer as a base polymer. The acrylic polymer is a polymer containing an acrylic monomer (a monomer having a (meth)acryloyl group in the molecule) as a monomer component of the polymer. The acrylic polymer is preferably a polymer containing an alkyl (meth)acrylate as a monomer component of the polymer. It should be noted that the acrylic polymers may be used alone or in combination of two or more.

[0088] The pressure-sensitive adhesive layer of the present invention is an acrylic pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer, and is preferably formed from an active energy ray-curable acrylic pressure-sensitive adhesive composition.

[0089] As the adhesive composition (acrylic adhesive composition) forming the above-mentioned acrylic adhesive layer, for example, there can be mentioned: an acrylic adhesive composition having an acrylic polymer as an essential component, or an acrylic adhesive composition having a mixture of monomers (monomers) constituting acrylic polymers (sometimes referred to as a "monomer mixture") or a partial polymer thereof as an essential component. As the former, for example, the so-called solvent-based acrylic adhesive composition can be mentioned. In addition, as the latter, for example, the so-called active energy ray-curable acrylic adhesive composition can be mentioned. The above-mentioned "monomer mixture" refers to a mixture containing monomer components constituting a polymer. In addition, the above-mentioned "partial polymer" is sometimes also referred to as a "prepolymer", which refers to a composition formed by partial polymerization of one or more monomer components among the monomer components in the above-mentioned monomer mixture.

[0090] The acrylic polymer is a polymer composed (formed) of an acrylic monomer as an essential monomer component (monomer component). The acrylic polymer is preferably a polymer composed (formed) of an alkyl (meth)acrylate as an essential monomer component. That is, the acrylic polymer preferably contains an alkyl (meth)acrylate as a structural unit. In this specification, "(meth)acrylic acid" means "acrylic acid" and / or "methacrylic acid" (either or both of "acrylic acid" and "methacrylic acid"), and the same applies to others. It should be noted that the acrylic polymer is composed of one or more monomer components.

[0091] As the aforementioned alkyl (meth)acrylate as an essential monomer component, preferably, there can be mentioned alkyl (meth)acrylates having a linear or branched alkyl group.

[0092] The alkyl (meth)acrylate having a linear or branched alkyl group is not particularly limited, and examples thereof include alkyl (meth)acrylates having a linear or branched alkyl group with 1 to 20 carbon atoms. Among these alkyl (meth)acrylates having a linear or branched alkyl group, those having a linear or branched alkyl group with 4 to 18 carbon atoms are preferred. These alkyl (meth)acrylates having a linear or branched alkyl group may be used alone or in combination of two or more.

[0093] The proportion of the alkyl (meth)acrylate in all monomer components (100 wt %) constituting the acrylic polymer is not particularly limited, but is preferably 50 wt % or more (e.g., 50 to 100 wt %), more preferably 53 to 90 wt %, and even more preferably 55 to 85 wt %.

[0094] The acrylic polymer may contain a copolymerizable monomer together with the (meth)acrylate as a monomer component constituting the polymer. That is, the acrylic polymer may contain a copolymerizable monomer as a structural unit. It should be noted that the copolymerizable monomer may be used alone or in combination of two or more.

[0095] The copolymerizable monomer is not particularly limited. From the perspectives of suppressing clouding in high-humidity environments, improving durability, compatibility with various additives such as ultraviolet absorbers, and transparency, preferred examples include monomers containing nitrogen atoms in the molecule and monomers containing hydroxyl groups in the molecule. Specifically, the acrylic polymer preferably contains a monomer containing nitrogen atoms in the molecule as a structural unit. Furthermore, the acrylic polymer preferably contains a monomer containing hydroxyl groups in the molecule as a structural unit.

[0096] The monomer having a nitrogen atom in the molecule is a monomer (monomer) having at least one nitrogen atom in the molecule (one molecule). In this specification, the "monomer having a nitrogen atom in the molecule" is sometimes referred to as a "nitrogen atom-containing monomer." The nitrogen atom-containing monomer is not particularly limited, but preferably includes cyclic nitrogen-containing monomers and (meth)acrylamides. It should be noted that the nitrogen atom-containing monomers can be used alone or in combination of two or more.

[0097] As the nitrogen atom-containing monomer, a cyclic nitrogen-containing monomer is preferred, and N-vinyl cyclic amide is more preferred. More specifically, N-vinyl pyrrolidone (NVP) is particularly preferred.

[0098] The monomer having a hydroxyl group in the above-mentioned molecule is a monomer having at least one hydroxyl group (hydroxyl group) in the molecule (in one molecule), preferably a monomer having a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group and having a hydroxyl group. Among them, the monomer having a hydroxyl group in the molecule does not include the nitrogen atom-containing monomer. That is, in this specification, the monomer having both a nitrogen atom and a hydroxyl group in the molecule is included in the above-mentioned "nitrogen atom-containing monomer". In this specification, the above-mentioned "monomer having a hydroxyl group in the molecule" is sometimes referred to as a "hydroxyl-containing monomer". It should be noted that the hydroxyl-containing monomer can be used alone or in combination of two or more.

[0099] Examples of the hydroxyl-containing monomer include hydroxyl-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate; vinyl alcohol; and allyl alcohol.

[0100] Among them, as the hydroxyl group-containing monomer, hydroxyl group-containing (meth)acrylates are preferred, and 2-hydroxyethyl acrylate (HEA) and 4-hydroxybutyl acrylate (4HBA) are more preferred.

[0101] When the acrylic polymer contains the hydroxyl-containing monomer as a monomer component constituting the polymer, the proportion of the hydroxyl-containing monomer in the total monomer components (100% by weight) constituting the acrylic polymer is not particularly limited. From the perspective of suppressing clouding in high-humidity environments and improving durability, it is preferably 0.5% by weight or more, more preferably 0.8% by weight or more, and even more preferably 1% by weight or more. Furthermore, from the perspective of obtaining an adhesive layer having moderate flexibility and excellent transparency, the upper limit of the proportion of the hydroxyl-containing monomer is preferably 30% by weight or less, more preferably 25% by weight or less, and even more preferably 15% by weight or less.

[0102] The total proportion of the nitrogen-containing monomer and the hydroxyl-containing monomer in the total monomer components (100% by weight) constituting the acrylic polymer is not particularly limited. However, from the perspective of suppressing clouding in high-humidity environments and improving durability, it is preferably 1% by weight or more, more preferably 5% by weight or more, and even more preferably 10% by weight or more. Furthermore, from the perspective of obtaining an adhesive layer having moderate flexibility and excellent transparency, the upper limit of the total of the above proportions is preferably 50% by weight or less, more preferably 40% by weight or less, and even more preferably 35% by weight or less.

[0103] In addition, examples of the copolymerizable monomers include: alicyclic structure-containing monomers, multifunctional monomers, alkoxyalkyl (meth)acrylates, carboxyl group-containing monomers, epoxy group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, (meth)acrylates having an aromatic hydrocarbon group, vinyl esters, aromatic vinyl compounds, olefins or dienes, vinyl ethers, vinyl chloride, etc. Examples of the carboxyl group-containing monomers include: (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. In addition, the carboxyl group-containing monomers also include anhydride group-containing monomers such as maleic anhydride and itaconic anhydride.

[0104] In the case where the adherend of the adhesive layer is a wiring comprising a metal or metal oxide such as a touch panel, from the viewpoint of obtaining an acrylic adhesive layer with excellent corrosion resistance, the acrylic polymer preferably does not contain or substantially does not contain an acidic group-containing monomer as a monomer component constituting the polymer, and particularly preferably does not contain or substantially does not contain a carboxyl group-containing monomer. Examples of acidic group-containing monomers include carboxyl group-containing monomers, sulfonic acid group-containing monomers, and phosphoric acid group-containing monomers. Specifically, the ratio of acidic group-containing monomers in all monomer components (100% by weight) constituting the acrylic polymer is 0.05% by weight or less (preferably 0.01% by weight or less), which can be referred to as substantially free of acidic group-containing monomers.

[0105] The content of the base polymer (especially the acrylic polymer) in the adhesive layer of the present invention is not particularly limited. However, it is preferably 50% by weight or more (e.g., 50% to 100% by weight), more preferably 80% by weight or more (e.g., 80% to 100% by weight), and even more preferably 90% by weight or more (e.g., 90% to 100% by weight), relative to 100% by weight of the total weight of the adhesive layer of the present invention.

[0106] In forming the adhesive layer of the present invention, a crosslinking agent may be used without particular limitation. For example, the acrylic polymer in the acrylic adhesive layer may be crosslinked to control the gel fraction. It should be noted that the crosslinking agent may be used alone or in combination of two or more. Preferred crosslinking agents include isocyanate crosslinking agents and epoxy crosslinking agents, with isocyanate crosslinking agents being more preferred.

[0107] When a crosslinking agent is used to form the adhesive layer of the present invention, the amount of the crosslinking agent used is not particularly limited. However, from the perspective of achieving sufficient adhesive reliability, the amount is preferably 0.001 parts by weight or more, and more preferably 0.01 parts by weight or more, relative to 100 parts by weight of the base polymer. Furthermore, from the perspective of achieving appropriate flexibility and improved adhesive strength in the adhesive layer, the upper limit of the amount used is preferably 10 parts by weight or less, and more preferably 5 parts by weight or less, relative to 100 parts by weight of the base polymer.

[0108] To improve adhesion reliability under humid conditions, particularly to glass, the adhesive layer (particularly an acrylic adhesive layer) of the present invention may contain a silane coupling agent. It should be noted that the silane coupling agent may be used alone or in combination of two or more. The inclusion of a silane coupling agent in the adhesive layer can improve adhesion under humid conditions, particularly to glass.

[0109] The adhesive layer of the present invention may further contain additives such as a crosslinking accelerator, a tackifying resin (such as a rosin derivative, a polyterpene resin, a petroleum resin, or an oil-soluble phenolic resin), an anti-aging agent, a filler, a colorant (such as a pigment or dye), an antioxidant, a chain transfer agent, a plasticizer, a softener, a surfactant, and an antistatic agent, as needed, within a range that does not impair the effects of the present invention. It should be noted that these additives may be used alone or in combination of two or more.

[0110] (Adhesive layer)

[0111] The adhesive layer is a layer capable of bonding substances by being sandwiched between adherends. When the adherends bonded with the adhesive layer are peeled off, the adhesive layer does not have practical adhesive strength.

[0112] Various adhesives can be used as adhesives to form the adhesive layer (hereinafter sometimes referred to as the "adhesive layer of the present invention") constituting the optical element of the present invention, including isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latex adhesives, and water-based polyester adhesives. These adhesives are generally used as adhesives comprising aqueous solutions (water-based adhesives) and contain 0.5% to 60% by weight of solids. Among them, polyvinyl alcohol adhesives are preferred, and polyvinyl alcohol adhesives containing acetoacetyl groups are more preferred.

[0113] Examples of the adhesive include, in addition to the above, active energy ray-curable adhesives such as crosslinking agents, ultraviolet curable adhesives, and electron beam curable adhesives. Examples of the active energy ray-curable adhesive include (meth)acrylate adhesives.

[0114] (Resin layer)

[0115] The resin layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "resin layer of the present invention") is not particularly limited, and examples thereof include plastic films. As raw materials for the above-mentioned plastic films, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) that are excellent in dimensional stability and not prone to shrinkage, cyclic olefin polymers (COP), polycarbonate (PC), polyetheretherketone (PEEK), and transparent polyimide (CPI) are preferred. Polyethylene terephthalate (PET) and transparent polyimide (CPI) are more preferred, and transparent polyimide (CPI) with excellent impact resistance is particularly preferred. It should be noted that these plastic materials can be used alone or in combination of two or more. The release liner that is peeled off when using the optical element of the present invention (when pasting) is not included in the "resin layer".

[0116] (Glass layer)

[0117] The glass layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "glass layer of the present invention") is not particularly limited, and an appropriate glass layer may be employed depending on the intended purpose. The glass preferably contains an alkali metal component (e.g., Na2O, K2O, Li2O) of 15% by weight or less, more preferably 10% by weight or less.

[0118] (Hard Coating)

[0119] The hard coating layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "hard coating layer of the present invention") can be formed from any suitable resin as long as it has sufficient surface hardness, excellent mechanical strength, and excellent light transmittance. Specific examples of resins include thermosetting resins, thermoplastic resins, ultraviolet curing resins, electron beam curing resins, and two-component mixed resins. Ultraviolet curing resins are preferred. This is because the hard coating layer can be formed with simple operation and high efficiency.

[0120] Specific examples of UV-curable resins include polyesters, acrylics, urethanes, amides, silicones, and epoxies. UV-curable resins include UV-curable monomers, oligomers, and polymers. Preferred UV-curable resins include resin compositions containing acrylic monomers or oligomers having preferably two or more, and more preferably three to six, UV-polymerizable functional groups. Typically, UV-curable resins contain a photopolymerization initiator.

[0121] The thickness of the hard coat layer of the present invention is, for example, 2 μm to 20 μm, preferably 4 μm to 15 μm, and more preferably 4 μm to 10 μm.

[0122] From the viewpoint of antifouling properties, the water contact angle of the hard coat layer of the present invention is preferably 95° or greater, more preferably 100° or greater, and even more preferably 105° or greater.

[0123] The water contact angle of the hard coat layer of the present invention is measured according to JIS R3257 and can be adjusted by the type of resin constituting the hard coat layer, curing conditions, etc. The water contact angle of the hard coat layer of the present invention after the steel wool test described below is preferably within the above range.

[0124] <Steel Wool Test>

[0125] Steel wool "Model #0000" manufactured by TRUSCO was cut into 1 cm squares and rubbed against the surface of the hard coating with 1000 reciprocating strokes under the conditions of a load of 1 kg and a moving speed of 100 mm / sec.

[0126] From the viewpoint of excellent surface hardness and scratch resistance, the Vickers hardness of the hard coating layer of the present invention is preferably 80 or higher, more preferably 90 or higher, and even more preferably 100 or higher.

[0127] The Vickers hardness of the hard coat layer of the present invention is measured in accordance with JIS Z2244 and can be adjusted by the type of resin constituting the hard coat layer, curing conditions, and the like.

[0128] From the viewpoint of antifouling properties, the surface element ratio of carbon in the hard coating layer of the present invention is 50 atomic % or less, preferably 45 atomic % or less, and the surface element ratio of fluorine in the hard coating layer is 30 atomic % or more.

[0129] The nitrogen element ratio in the surface of the hard coat layer is, for example, less than 1.5 atomic %, preferably 1.3 atomic % or less, for example, 0 atomic % or more.

[0130] The surface element ratio of fluorine, carbon, and nitrogen on the surface of the hard coat layer of the present invention can be measured by X-ray photoelectron spectroscopy and can be adjusted by the type of resin constituting the hard coat layer, curing conditions, and the like.

[0131] (Anti-reflection layer)

[0132] The antireflection layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "antireflection layer of the present invention") is preferably composed of an inorganic substance. Examples of the inorganic substance include those exemplified and described as materials constituting the high refractive index layer, low refractive index layer, and medium refractive index layer described below.

[0133] The antireflection layer of the present invention may have any appropriate structure, for example: (i) a single layer having an optical film thickness of 120 nm to 140 nm and a low refractive index layer having a refractive index of 1.35 to 1.55, (ii) a laminate having a medium refractive index layer, a high refractive index layer, and a low refractive index layer in this order, and (iii) a laminate having a plurality of layers alternating high refractive index layers and low refractive index layers.

[0134] Examples of materials that can form the low-refractive-index layer include silicon oxide (SiO 2 ) and magnesium fluoride (MgF 2 ). The refractive index of the low-refractive-index layer is typically about 1.35 to 1.55.

[0135] The material of the low refractive index layer can be a cured product of a curable fluorine-containing resin. The curable fluorine-containing resin, for example, has a structural unit derived from a fluorine-containing monomer and a structural unit derived from a crosslinkable monomer. As specific examples of fluorine-containing monomers, for example, there can be listed: fluoroolefins (vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, etc.), (meth)acrylate derivatives with partially or completely fluorinated alkyl groups (Viscoat 6FM (manufactured by Osaka Organic Chemical Co., Ltd.), M-2020 (manufactured by Daikin Corporation), etc.), completely or partially fluorinated vinyl ethers, etc. As crosslinkable monomers, for example, there can be listed: (meth)acrylate monomers having crosslinkable functional groups in the molecule such as glycidyl methacrylate; (meth)acrylate monomers having functional groups such as carboxyl, hydroxyl, amino, and sulfonic acid groups ((meth)acrylic acid, hydroxymethyl (meth)acrylate, hydroxyalkyl (meth)acrylate, allyl (meth)acrylate, etc.). The fluorine-containing resin may have a structural unit derived from a monomer other than the above-mentioned compounds (for example, an olefin-based monomer, a (meth)acrylate-based monomer, a styrene-based monomer).

[0136] Examples of materials that can form the high refractive index layer include titanium oxide (TiO2), niobium oxide (Nb2O3 or Nb2O5), tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), and ZrO2-TiO2. The refractive index of the high refractive index layer is typically about 1.60 to 2.40.

[0137] Examples of materials capable of forming the medium refractive index layer include titanium oxide (TiO2), a mixture of a material capable of forming a low refractive index layer and a material capable of forming a high refractive index layer (e.g., a mixture of titanium oxide and silicon oxide). The refractive index of the medium refractive index layer is typically about 1.50 to about 1.85. The thicknesses of the low refractive index layer, the medium refractive index layer, and the high refractive index layer can be set to achieve an appropriate optical film thickness corresponding to the layer structure of the antireflection layer, the desired antireflection performance, etc.

[0138] The thickness of the anti-reflection layer of the present invention is, for example, about 20 nm to about 300 nm.

[0139] From the viewpoint of antifouling properties, the water contact angle of the antireflection layer of the present invention is preferably 90° or greater, more preferably 95° or greater, further preferably 100° or greater, and particularly preferably 105° or greater.

[0140] The water contact angle of the antireflection layer of the present invention is measured according to JIS R3257, and can be regulated by the kind of the component that constitutes the antireflection layer etc. In addition, the water contact angle of the antireflection layer of the present invention preferably after the following eraser test is within the above-mentioned range. By laminating the antireflection layer having a water contact angle after the eraser test within these ranges on the visual recognition side, particularly the outermost surface, of the OLED display device, even after the OLED display device is rubbed by a hand or cloth, excellent antifouling properties can be maintained.

[0141] Eraser Test

[0142] An eraser for evaluating wear resistance manufactured by Minoan, Model 4004005007, was cut into 7 mm pieces and rubbed against the surface of the hard coating layer 6000 times in a reciprocating motion under conditions of a load of 1 kg and a moving speed of 32 mm / sec.

[0143] (Anti-glare layer)

[0144] As the antiglare layer constituting the optical element of the present invention (hereinafter sometimes referred to as "the antiglare layer of the present invention"), any known antiglare layer can be employed without limitation. It is generally formed as a layer in which inorganic or organic particles serving as an antiglare agent are dispersed in a resin.

[0145] The anti-glare layer of the present invention is not particularly limited. For example, it can be formed using an anti-glare layer-forming material comprising a resin, particles, and a thixotropy-imparting agent. The particles and thixotropy-imparting agent aggregate to form convex portions on the surface of the anti-glare layer of the present invention. This configuration allows the anti-glare layer to exhibit excellent display properties, achieving both anti-glare properties and preventing white blur. Furthermore, while the anti-glare layer is formed by agglomeration of particles, the formation of protrusions on the surface of the anti-glare layer, which can cause appearance defects, can be prevented, thereby improving the product yield.

[0146] Examples of the resin include thermosetting resins and ionizing radiation curable resins that are cured by ultraviolet rays or light. Commercially available thermosetting resins and ultraviolet curable resins may also be used as the resin.

[0147] As the above-mentioned thermosetting resin and ultraviolet curing resin, for example, a curable compound having at least one of an acrylate group and a methacrylate group that is cured by heat, light (ultraviolet rays, etc.), or electron beams, can be used. Examples thereof include oligomers or prepolymers such as acrylates or methacrylates of polyfunctional compounds such as silicone resins, polyester resins, polyether resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polyols. These can be used alone or in combination of two or more.

[0148] The above-mentioned resin may also use a reactive diluent having at least one of an acrylate group and a methacrylate group. The above-mentioned reactive diluent may be, for example, the reactive diluents described in Japanese Patent Application Laid-Open No. 2008-88309, such as monofunctional acrylates, monofunctional methacrylates, multifunctional acrylates, and multifunctional methacrylates. As the above-mentioned reactive diluent, trifunctional or higher acrylates and trifunctional or higher methacrylates are preferred. This is because they can improve the hardness of the anti-glare layer of the present invention. As the above-mentioned reactive diluent, for example, butanediol glyceryl ether diacrylate, isocyanuric acid acrylates, isocyanuric acid methacrylates, etc. may also be mentioned. These may be used alone or in combination of two or more.

[0149] The resin preferably includes a urethane acrylate resin, and more preferably a copolymer of a curable urethane acrylate resin and a multifunctional acrylate (for example, pentaerythritol triacrylate).

[0150] The primary functions of the particles used to form the anti-glare layer of the present invention are to impart anti-glare properties to the surface of the anti-glare layer to be formed by forming a concavo-convex shape, and to control the haze value of the anti-glare layer. The haze value of the anti-glare layer can be designed by controlling the refractive index difference between the particles and the resin. Examples of the particles include inorganic particles and organic particles.

[0151] The weight average particle size (D) of the above-mentioned particles is preferably in the range of 2.5μm to 10μm. By making the weight average particle size of the particles within the above-mentioned range, for example, the anti-glare property can be made more excellent and white blur can be prevented. The weight average particle size of the above-mentioned particles is more preferably in the range of 3μm to 7μm. It should be noted that the weight average particle size of the above-mentioned particles can be measured by, for example, the Coulter counting method. For example, a particle size distribution measuring device using a pore resistance method (trade name: Coulter counter, manufactured by Beckman Coulter) is used to measure the resistance of the electrolyte equivalent to the volume of the particles when the particles pass through the above-mentioned pores, thereby measuring the number and volume of the above-mentioned particles and calculating the weight average particle size.

[0152] The shape of the above-mentioned particles is not particularly limited. For example, they can be roughly spherical in the form of beads, or they can be irregularly shaped particles such as powder. Preferably, they are roughly spherical particles, more preferably, they are roughly spherical particles with an aspect ratio of less than 1.5, and most preferably, they are spherical particles.

[0153] The proportion of the particles in the anti-glare layer of the present invention is preferably in the range of 0.2 to 12 parts by weight, more preferably in the range of 0.5 to 12 parts by weight, and even more preferably in the range of 1 to 7 parts by weight, relative to 100 parts by weight of the resin. By setting the proportion within the above range, for example, the anti-glare properties are further improved and white blur can be prevented.

[0154] The anti-glare layer of the present invention may contain a thixotropy-imparting agent. By including the thixotropy-imparting agent, the agglomerated state of the particles can be easily controlled. Examples of thixotropy-imparting agents used to form the anti-glare layer of the present invention include organoclays, oxidized polyolefins, and modified ureas. One of the thixotropy-imparting agents may be used alone, or two or more may be used in combination.

[0155] The height of the roughness average line of the anti-glare layer of the present invention from the above-mentioned convex portion is preferably less than 0.4 times the thickness of the anti-glare layer. More preferably, it is in the range of greater than or equal to 0.01 times and less than 0.4 times, and further preferably in the range of greater than or equal to 0.01 times and less than 0.3 times. If it is within this range, it is possible to appropriately prevent protrusions that become appearance defects from being formed on the convex portion. The anti-glare layer of the present invention can be less prone to appearance defects by having a convex portion of such a height. Here, the height from the above-mentioned average line can be measured, for example, by the method described in Japanese Patent Application Laid-Open No. 2017-138620.

[0156] The ratio of the thixotropy-imparting agent in the anti-glare layer of the present invention is preferably in the range of 0.1 to 5 parts by weight, more preferably in the range of 0.2 to 4 parts by weight, relative to 100 parts by weight of the resin.

[0157] The thickness (d') of the anti-glare layer of the present invention is not particularly limited, and is preferably in the range of 2μm to 12μm. By making the thickness (d') of the anti-glare layer within the above range, for example, the optical laminate of the present invention can be prevented from curling, and problems such as poor transportability and reduced productivity can be avoided. In addition, when the thickness (d') is within the above range, as described above, the weight average particle size (D) of the particles is preferably in the range of 2.5μm to 10μm. By combining the thickness (d') of the anti-glare layer of the present invention and the weight average particle size (D) of the particles as described above, the anti-glare property can be made more excellent. The thickness (d') of the anti-glare layer of the present invention is more preferably in the range of 2μm to 10μm, and further preferably in the range of 3μm to 8μm.

[0158] The relationship between the thickness (d') of the anti-glare layer of the present invention and the weight average particle size (D) of the particles is preferably within the range of 0.3 ≤ D / d' ≤ 0.9. This relationship can further improve anti-glare properties, prevent white blur, and produce an anti-glare layer without appearance defects.

[0159] The haze value (H') of the anti-glare layer of the present invention is not particularly limited. From the perspective of effectively reducing color shift and interference unevenness in OLED displays, it is preferably 5% or greater, more preferably 10% or greater, even more preferably 15% or greater, and particularly preferably 20% or greater. Furthermore, from the perspective of suppressing image blur in OLED displays and displaying high-definition images, the haze value of the anti-glare layer of the present invention is preferably 80% or less, more preferably 70% or less, even more preferably 60% or less, and particularly preferably 50% or less.

[0160] The haze value of the anti-glare layer of the present invention can be measured by the method specified in JIS K7136 and can be designed by controlling the type and thickness of the anti-glare layer and the refractive index difference between the particles and the resin.

[0161] The anti-glare layer of the present invention forms convex portions on the surface of the anti-glare layer of the present invention by agglomerating the particles and the thixotropy-imparting agent. Within the agglomerated portions forming the convex portions, the particles are present in a plurality of aggregates in the direction of the surface of the anti-glare layer of the present invention. As a result, the convex portions have a flat shape. The anti-glare layer of the present invention, having convex portions of such a shape, can prevent white blur while maintaining anti-glare properties and is less susceptible to appearance defects.

[0162] The surface shape of the anti-glare layer of the present invention can be arbitrarily designed by controlling the condensed state of the particles contained in the anti-glare layer forming material. The condensed state of the particles can be controlled, for example, by the material of the particles (for example, the chemical modification state of the particle surface, the affinity for the solvent or resin, etc.), the type and combination of the resin (binder) or solvent. Here, the condensed state of the particles can be controlled by the thixotropy imparting agent contained in the anti-glare layer forming material of the present invention. As a result, the condensed state of the particles can be made as described above, and the convex portion can be made into a gentle shape.

[0163] In the anti-glare layer of the present invention, it is preferred that the number of appearance defects with a maximum diameter of 200 μm or more is less per 1 m 2 More preferably, there is no such appearance defect.

[0164] In the concavo-convex shape of the anti-glare layer surface of the present invention, the average tilt angle θa (°) is preferably in the range of 0.1 to 5.0, more preferably in the range of 0.3 to 4.5, further preferably in the range of 1.0 to 4.0, and particularly preferably in the range of 1.6 to 4.0. Here, the average tilt angle θa is a value defined by the following mathematical formula (1). The above-mentioned average tilt angle θa is, for example, a value measured by the method described in Japanese Patent Application Laid-Open No. 2017-138620.

[0165] Average tilt angle θa = tan -1 Δa (1)

[0166] In the above mathematical formula (1), Δa is the value obtained by dividing the sum of the differences (height h) between the apex of adjacent peaks and the lowest point of valleys (h1+h2+h3...+hn) by the reference length L of the roughness curve specified in JIS B0601 (1994 edition), as shown in the following mathematical formula (2). The above roughness curve is a curve obtained by removing surface fluctuation components longer than a specified wavelength from a cross-sectional curve using a phase difference compensation high-frequency filter. The cross-sectional curve refers to the profile that appears at the cut when the target surface is cut along a plane perpendicular to the target surface.

[0167] Δa=(h1+h2+h3···+hn) / L (2)

[0168] When θa is within the above range, the anti-glare property is more excellent and white blurring can be prevented.

[0169] When forming the anti-glare layer of the present invention, the prepared anti-glare layer-forming material (coating solution) preferably exhibits thixotropy, and the Ti value specified below is preferably in the range of 1.3 to 3.5, more preferably in the range of 1.3 to 2.8.

[0170] Ti value = β1 / β2

[0171] Here, β1 is the viscosity measured using Rheo stress 6000 manufactured by HAAKE at a shear rate of 20 (1 / s), and β2 is the viscosity measured using Rheo stress 6000 manufactured by HAAKE at a shear rate of 200 (1 / s).

[0172] When the Ti value is less than 1.3, appearance defects are likely to occur, and the anti-glare properties and white blur properties are deteriorated. On the other hand, when the Ti value is greater than 3.5, the particles are less likely to aggregate and tend to be dispersed.

[0173] The hardness of the anti-glare layer of the present invention is also affected by the thickness of the layer in terms of pencil hardness, but preferably has a hardness of 2H or higher. The anti-glare layer of the present invention may have a multilayer structure in which two or more layers are stacked.

[0174] The anti-glare layer of the present invention may be disposed on the anti-glare layer. For example, one of the main reasons for reduced visual recognition of OLED displays is light reflection at the interface between air and the anti-glare layer. The anti-reflection layer reduces surface reflection. It should be noted that the anti-glare layer and the anti-reflection layer of the present invention may each be a multilayer structure formed by stacking two or more layers.

[0175] (Shock absorbing layer)

[0176] The impact-absorbing layer constituting the optical element of the present invention (hereinafter sometimes referred to as the "impact-absorbing layer of the present invention") can be formed from any suitable resin layer capable of achieving the desired impact absorption rate. The resin layer can be composed of a resin film or an adhesive. The impact-absorbing layer typically comprises an epoxy resin, a urethane resin, or an acrylic resin. These resins can be used alone or in combination.

[0177] (Antistatic layer)

[0178] The antistatic layer constituting the optical element of the present invention (hereinafter sometimes referred to as "the antistatic layer of the present invention") is not particularly limited, and may be formed by coating a conductive coating liquid containing a conductive polymer, for example.

[0179] (Optical laminate)

[0180] In the optical layered body of the present invention, [Rf1 / Rp1] is preferably 0.3 or less, more preferably 0.25 or less, further preferably 0.2 or less, further preferably 0.15 or less, and particularly preferably 0.1 or less. The smaller [Rf1 / Rp1] is, the more interference unevenness can be suppressed.

[0181] In the optical layered body of the present invention, [Rf2 / Rp2] is preferably 0.12 or less, more preferably 0.1 or less, further preferably 0.05 or less, further preferably 0.03 or less, and particularly preferably 0.01 or less. The smaller [Rf2 / Rp2] is, the more interference unevenness can be suppressed.

[0182] In the optical layered body of the present invention, the value of (d×H)×{[Rf1 / Rp1]+[Rf2 / Rp2]} is preferably 20,000 or less, more preferably 15,000 or less, and even more preferably 10,000 or less. This configuration can suppress white blur and image blur caused by the OLED display device of the present invention, resulting in excellent visual recognition.

[0183] The sum of [Rf1 / Rp1] and [Rf2 / Rp2] is preferably 0.42 or less, more preferably 0.4 or less, further preferably 0.3 or less, further preferably 0.2 or less, and particularly preferably 0.1 or less. The smaller the sum, the more interference unevenness can be suppressed.

[0184] In this specification, wavelength WL1 is, for example, 430 nm or 440 nm, and wavelength WL2 is, for example, 500 nm or 510 nm. Furthermore, Rp1 and Rp2 are each, for example, 7% or more (e.g., 7% to 20%), preferably 10% or more (e.g., 10% to 18%).

[0185] The optical laminate of the present invention preferably has a structure comprising a hard coating layer of the present invention, a substrate layer, and an adhesive layer of the present invention (particularly an adhesive layer having light scattering properties) on the side opposite to the visual recognition side of the anti-reflection layer of the present invention, and more preferably has a structure comprising these layers in this order. The above-mentioned substrate layer can use the resin layer of the present invention or the glass layer of the present invention.

[0186] The optical layered body of the present invention preferably has a structure in which the adhesive layer of the present invention (particularly an adhesive layer having light scattering properties) is provided on at least one side of the resin layer of the present invention. When the refractive index of the resin layer of the present invention is n1, the refractive index of the adhesive in the adhesive layer of the present invention is n2, and the refractive index of the light scattering fine particles of the present invention is n3, it is preferred that n1>n2>n3 be satisfied. In this case, white blurring is further suppressed.

[0187] In the optical layered body of the present invention, the refractive index (n1) of the resin layer of the present invention is preferably 1.50 to 1.80, more preferably 1.55 to 1.75, and even more preferably 1.60 to 1.70. The refractive index of the resin layer can be adjusted by the type and content of the resin constituting the resin layer.

[0188] The optical layered body of the present invention preferably has a structure in which the adhesive layer of the present invention (particularly an adhesive layer having light scattering properties) is provided on one surface of the resin layer of the present invention, and the hard coating layer of the present invention is provided on the other surface of the resin layer of the present invention. In particular, in this embodiment, it is preferred that n1>n2>n3 be satisfied.

[0189] In one embodiment of the optical layered body of the present invention (for example, Figures 5 to 7 In the optical laminate in the OLED display device of the present invention shown in FIG, a color filter is arranged on the visual recognition side of the OLED element, and when the distance (d) between the adhesive layer of the present invention and the above-mentioned color filter is 700 μm or less, the distance between the adhesive layer of the present invention (especially the adhesive layer having light scattering properties) and the above-mentioned color filter is set to d [μm], and the haze value of the adhesive layer of the present invention (especially the adhesive layer having light scattering properties) is set to H [%], the value of d×H is preferably 70,000 or less, more preferably 60,000 or less, and further preferably 50,000 or less. When the value of d×H is 700,000 or less, image blurring is less likely to occur. The value of d×H is, for example, 100 or more, and may be 1000 or more, 10,000 or more, or 20,000 or more. In this case, H is preferably 20 or more.

[0190] In one embodiment of the optical layered body of the present invention (for example, Figures 5 to 7 In the optical laminate in the OLED display device of the present invention shown in FIG, when the thickness of the adhesive layer of the present invention (particularly the adhesive layer having light scattering properties) is denoted as T [μm] and the haze value of the adhesive layer of the present invention (particularly the adhesive layer having light scattering properties) is denoted as H [%], the value of T×H is preferably 400 or greater, more preferably 600 or greater, even more preferably 800 or greater, even more preferably 1000 or greater, and particularly preferably 1500 or greater. When the value of T×H is 400 or less, image blurring is less likely to occur. The value of T×H is, for example, 10,000 or less, but may also be 8,000 or less, 6,000 or less, or 4,000 or less.

[0191] In one embodiment of the optical layered body of the present invention (for example, Figure 8In the optical laminate for the OLED display device of the present invention (shown as an optical laminate for the OLED display device of the present invention), when the scattering efficiency of the anti-glare layer of the present invention at a wavelength WL1 showing a maximum reflectance within the wavelength range of 380 nm to 455 nm in the reflectance spectrum of the OLED display device without the optical laminate is defined as S1, S1 is preferably 15% or more, more preferably 20% or more, even more preferably 30% or more, even more preferably 40% or more, and particularly preferably 50% or more. The larger S1 is, the more interference unevenness can be suppressed.

[0192] In one embodiment of the optical layered body of the present invention (for example, Figure 8 In the optical laminate for the OLED display device of the present invention (shown as an optical laminate for the OLED display device of the present invention), when the scattering efficiency of the anti-glare layer of the present invention at a wavelength WL2 showing a maximum reflectance within a wavelength range of 460 nm to 530 nm in the reflectance spectrum of the OLED display device without the optical laminate is defined as S2, S2 is preferably 15% or more, more preferably 20% or more, even more preferably 30% or more, even more preferably 40% or more, and particularly preferably 50% or more. The larger S2 is, the more interference unevenness can be suppressed.

[0193] When the transmittance at a specified wavelength measured in a state where the optical laminate having the anti-glare layer of the present invention is in contact with an integrating sphere is set as Tn1, and the transmittance at the above-mentioned specified wavelength measured in a state where the optical laminate having the anti-glare layer is set at a position 145 mm away from the integrating sphere is set as Tn2, the above-mentioned scattering efficiencies S1 and S2 are calculated as Tn1-Tn2.

[0194] The total of S1 and S2 is preferably 30% or more, more preferably 40% or more, further preferably 60% or more, further preferably 80% or more, and particularly preferably 100% or more. The greater the total, the more interference unevenness can be suppressed.

[0195] In one embodiment of the optical layered body of the present invention (for example, Figure 8 In the optical laminate in the OLED display device of the present invention shown in FIG, it is preferred that the substrate layer and the adhesive layer of the present invention be provided on the side of the anti-glare layer of the present invention opposite to the visual recognition side, and more preferably, the substrate layer has these layers in this order. The resin layer of the present invention or the glass layer of the present invention can be used as the substrate layer.

[0196] In one embodiment of the optical layered body of the present invention (for example, Figure 9In the optical laminate in the OLED display device of the present invention shown in FIG, as the optical element of the present invention, it is preferred that the optical laminate further comprises the adhesive layer of the present invention, the substrate layer, and the hard coating layer of the present invention on the visual recognition side of the glass layer of the present invention, and more preferably comprises these layers in this order. The substrate layer may be the resin layer of the present invention or the glass layer of the present invention.

[0197] In one embodiment of the optical layered body of the present invention (for example, Figure 9 In the optical laminate in the OLED display device of the present invention shown in FIG, when the indentation modulus of the adhesive layer of the present invention is denoted as Ea and the tensile storage modulus of the resin layer of the present invention is denoted as Er, the absolute value of Ea-Er is preferably 1 GPa or less, more preferably 0.9 GPa or less, further preferably 0.7 GPa or less, and particularly preferably 0.5 GPa or less. When the absolute value is 1 GPa or less, the impact resistance is further improved.

[0198] In one embodiment of the optical layered body of the present invention (for example, Figure 9 In the optical laminate in the OLED display device of the present invention shown in FIG, the tensile storage modulus Er of the resin layer of the present invention is preferably 4 GPa or more, more preferably 4.3 GPa or more, and further preferably 4.6 GPa or more. When the tensile storage modulus Er is 4 GPa or more, the impact resistance is further improved. The tensile storage modulus Er is, for example, 50 GPa or less, and may be 30 GPa or less, or 10 GPa or less. The tensile storage modulus Er can be measured according to JIS K7161.

[0199] In one embodiment of the optical layered body of the present invention (for example, Figure 10 In the optical laminate in the OLED display device of the present invention shown in FIG, it is preferable to have a structure in which an intermediate layer (compatible layer) is formed between the transparent polyimide layer and the hard coating layer of the present invention. By forming the intermediate layer, the adhesion between the transparent polyimide layer and the hard coating layer of the present invention is improved. The intermediate layer is a layer formed by the composition (coating agent) for forming the hard coating layer of the present invention penetrating into the transparent polyimide layer. That is, the intermediate layer is a portion of the transparent polyimide layer where the hard coating component of the present invention is present.

[0200] The ratio (P1) of the shear strength of the intermediate layer to the shear strength of the hard coat layer of the present invention is preferably 0.25 or less, more preferably 0.23, and even more preferably 0.21 or less. The ratio (P1) is, for example, 0.02 or more, and may be 0.05 or more, or 0.08 or more.

[0201] In one embodiment of the optical layered body of the present invention (for example, Figure 10 In the optical laminate in the OLED display device of the present invention shown in FIG, the ratio (P2) of the shear fracture strength of the transparent polyimide layer to the shear fracture strength of the hard coat layer of the present invention is preferably 0.65 or greater, more preferably 0.70 or greater, further preferably 0.80 or greater, and particularly preferably 0.90 or greater. The ratio (P2) is, for example, 1.50 or less, and may be 1.30 or less, or 1.10 or less.

[0202] The difference (P2-P1) between the ratio (P1) and the ratio (P2) is preferably 0.6 or more, more preferably 0.70 or more, and may be 0.80 or more. The difference (P2-P1) is, for example, 1.5 or less, 1.2 or less, or 0.9 or less.

[0203] In one embodiment of the optical layered body of the present invention (for example, Figure 10 In the optical laminate in the OLED display device of the present invention shown in FIG, it is preferred that the transparent polyimide layer further has an adhesive layer on the side opposite to the hard coat layer of the present invention.

[0204] (Method for producing an optical laminate)

[0205] The method for manufacturing the optical laminate of the present invention is not particularly limited, and can be manufactured by sequentially stacking the adhesive layer, adhesive layer, resin layer, glass layer, hard coating layer, anti-reflection layer, anti-glare layer, intermediate layer (compatible layer), impact absorbing layer, etc., which constitute the optical element of the present invention on the visual recognition side of the OLED display panel of the present invention. In addition, it can be manufactured by pre-making a laminate constituting the optical laminate of the present invention and laminating it on the visual recognition side of the OLED display panel of the present invention. In the case of pre-making a laminate constituting the optical laminate of the present invention, it can be a laminate constituting the entirety of the optical laminate of the present invention, or a laminate constituting a part of the optical laminate of the present invention can be separately laminated on the visual recognition side of the OLED display panel of the present invention.

[0206] The layers constituting the optical element of the present invention or the laminate thereof may be protected with a release liner or a surface protective film until use.

[0207] (Release liner)

[0208] When the optical element of the present invention includes an adhesive layer, a release liner can be provided on the surface (adhesive surface) of the adhesive layer before use. The release liner is used as a protective material for the adhesive layer and is peeled off when the adhesive is attached to an adherend. It should be noted that the release liner does not constitute the optical element of the present invention and does not need to be provided. As the above-mentioned release liner, conventional release paper etc. can be used, without particular limitation, and for example, a substrate with a peeling treatment layer, a low-adhesive substrate comprising a fluorine-containing polymer, a low-adhesive substrate comprising a non-polar polymer, etc. can be cited.

[0209] (Surface protection film)

[0210] The outermost surface (the outermost surface on the visual recognition side) of the optical layered body of the present invention can be protected by a surface protective film. The surface protective film can be applied by the consumer. It should be noted that the surface protective film does not constitute the optical element of the present invention and does not need to be provided.

[0211] (OLED display device of the present invention)

[0212] Hereinafter, one embodiment of an OLED display device in which the optical laminate of the present invention is laminated on the viewing side of an OLED display panel will be described with reference to the drawings. However, the present invention is not limited to this embodiment. Figure 2 This is a schematic cross-sectional view showing one embodiment of the basic configuration of an OLED display device in which the optical laminate of the present invention is laminated.

[0213] like Figure 2 As shown, the OLED display device 200 is on the visual recognition side ( Figure 2 The OLED display panel 100 is not particularly limited, and may be, for example, Figure 1 The OLED display panel 100 has the same structure as described in .

[0214] exist Figure 2 In the OLED display device 200, 21 to 29 are layers constituting the optical laminate 20, 21 represents an adhesive layer or a bonding agent layer, 22 represents a resin layer, a glass layer or an impact-absorbing layer, 23 represents a hard coating layer or an anti-glare layer, 24 represents an adhesive layer or an adhesive layer, 25 represents a resin layer, a glass layer or an impact-absorbing layer, 26 represents an adhesive layer or an adhesive layer, 27 represents a resin layer, a glass layer or an impact-absorbing layer, 28 represents a hard coating layer or an anti-glare layer, and 29 represents an anti-reflection layer. Figure 2 The stacked structure of the optical stack 20 shown is not limited to this embodiment, and may be Figure 2 The optical layered structure of the optical layered body 20 shown may include other layers constituting the optical element of the present invention inserted between any of the layers, or may not exist. Figure 2Any layer of the stacked structure of the optical stack 20 shown.

[0215] As a preferred embodiment of the present invention, Figure 2 In the embodiment, 24 is an adhesive layer or a gluing layer, 25 is a glass layer, 26 is an adhesive layer or a gluing layer, 27 is a resin layer, 28 is a hard coating layer, 29 is an anti-reflection layer, and 21 to 23 are not present. At least one of the adhesive layers 24 and 26 is an adhesive layer having light scattering properties. Figure 3 FIG shows an OLED display device 300A of this embodiment. Figure 3 In the figure, 34A to 39A are layers constituting the optical laminate 30A. 34A is an adhesive layer, 35A is a glass layer, 36A is an adhesive layer having light scattering properties, 37A is a resin layer, 38A is a hard coat layer, and 39A is an antireflection layer. The presence of the antireflection layer 39A in the optical laminate 30A suppresses interference unevenness and white blurring caused by the OLED display panel 100, resulting in excellent visual recognition of the OLED display device 300A.

[0216] exist Figure 3 In the OLED display device 300A shown, 38A may also be an anti-glare layer, or an anti-glare layer may be stacked between the hard coat layer 38A and the anti-reflection layer 39A. In this embodiment, by stacking the anti-glare layer 38A and the anti-reflection layer 39A, the anti-reflection function is further enhanced.

[0217] As a preferred embodiment of the present invention, Figure 2 In the figure, 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coating layer, 24 is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 is a resin layer, 28 is a hard coating layer, and 29 is an anti-reflection layer. At least one of the adhesive layers 21, 24, and 26 is an adhesive layer having light scattering properties. Figure 4 FIG shows an OLED display device 300B of this embodiment. Figure 4 In the figure, 31B to 39B are layers constituting the optical laminate 30B. 31B is an adhesive layer, 32B is a resin layer, 33B is a hard coat layer, 34B is an adhesive layer, 35B is a glass layer, 36B is an adhesive layer with light scattering properties, 37B is a resin layer, 38B is a hard coat layer, and 39B is an antireflection layer. The presence of the antireflection layer 39B in the optical laminate 30B suppresses interference unevenness and white blurring caused by the OLED display panel 100, resulting in excellent visual recognition of the OLED display device 300B.

[0218] exist Figure 4In the OLED display device 300B shown, 38B may also be an anti-glare layer, or an anti-glare layer may be stacked between the hard coating layer 38B and the anti-reflection layer 39B. In this embodiment, by stacking the anti-glare layer 38B and the anti-reflection layer 39B, the anti-reflection function is further improved ( Figure 8 ).

[0219] As another preferred embodiment of the present invention, Figure 2 In the OLED display panel 100, a color filter is configured on the visual recognition side, 26 is an adhesive layer with light scattering properties, 27 is a resin layer, 28 is a hard coating layer, 29 is an anti-reflection layer, and 21 to 25 do not exist. The distance d (μm) between the adhesive layer 26 with light scattering properties and the color filter is 700 μm or less. By setting the distance d between the adhesive layer with light scattering properties and the color filter to be 700 μm or less, even if a light scattering layer is stacked to suppress color shift and interference unevenness caused by the OLED display device 200, image blur is not easily generated, and visual recognition is excellent. From the viewpoint of more effectively reducing the image blur of the OLED display device caused by the stacked light scattering layer, the distance between the adhesive layer with light scattering properties and the color filter is more preferably less than 600 μm, further preferably less than 500 μm, and most preferably the adhesive layer with light scattering properties is in direct contact with the color filter. In Figure 5 FIG shows an OLED display device 400A of this embodiment. Figure 5 46A to 49A are layers constituting the optical laminate 40A, 46A is an adhesive layer having light scattering properties, 47A is a resin layer, 48A is a hard coating layer, and 49A is an anti-reflection layer. 15A is configured on the visual recognition side of the OLED display panel 400A (on the Figure 5 The light-scattering adhesive layer 46A is in direct contact with the color filter 15A. That is, the distance between the light-scattering adhesive layer 46A and the color filter 15A is 0 μm. This effectively suppresses color shift and interference unevenness caused by the OLED display device 400A.

[0220] It should be noted that in Figure 5 In the OLED display device 400A shown, 48A may also be an anti-glare layer, or an anti-glare layer may be present between the hard coating layer 48A and the anti-reflection layer 49A.

[0221] As another preferred embodiment of the present invention, Figure 2In the figure, the OLED display panel 100 is provided with a color filter on the visual recognition side, 24 is an adhesive layer with light scattering properties, 25 is a glass layer, 26 is an adhesive layer or an adhesive layer, 27 is a resin layer, 28 is a hard coating layer, 29 is an anti-reflection layer, and 21 to 23 do not exist. The distance d (μm) between the adhesive layer 24 with light scattering properties and the color filter is 700 μm or less. By setting the distance d between the adhesive layer with light scattering properties and the color filter to be 700 μm or less, even if a light scattering layer is stacked to suppress color shift and interference unevenness caused by the OLED display device 200, image blur is not easily generated, and visual recognition is excellent. From the viewpoint of more effectively reducing the image blur of the OLED display device caused by the stacked light scattering layer, the distance between the adhesive layer with light scattering properties and the color filter is more preferably less than 600 μm, further preferably less than 500 μm, and most preferably the adhesive layer with light scattering properties is in direct contact with the color filter. In the figure, Figure 6 FIG shows an OLED display device 400B of this embodiment. Figure 6 In the figure, 44B to 49B are layers constituting the optical laminate 40B, 44B is an adhesive layer having light scattering properties, 45B is a glass layer, 46B is an adhesive layer or a glue layer, 47B is a resin layer, 48B is a hard coating layer, and 49B is an anti-reflection layer. 15B is configured on the visual recognition side of the OLED display panel 400B (on the Figure 6 The light-scattering adhesive layer 46B is in direct contact with the color filter 15B. That is, the distance between the light-scattering adhesive layer 46B and the color filter 15B is 0 μm. This effectively suppresses color shift and interference unevenness caused by the OLED display device 400B.

[0222] It should be noted that in Figure 6 In the OLED display device 400B shown, 48B may also be an anti-glare layer, or an anti-glare layer may exist between the hard coating layer 48B and the anti-reflection layer 49B.

[0223] As another preferred embodiment of the present invention, Figure 2In the OLED display panel 100, a color filter is configured on the visual recognition side. 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coating layer, 24 is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 is a resin layer, 28 is a hard coating layer, and 29 is an anti-reflection layer. At least one of the adhesive layers 21, 24, and 26 is an adhesive layer having light scattering properties, and the distance d (μm) between the light scattering adhesive layer and the color filter is 700 μm or less. Because the distance d between the light scattering adhesive layer and the color filter is 700 μm or less, even if a light scattering layer is laminated to suppress color shift and interference unevenness caused by the OLED display device 300, image blur is unlikely to occur, and visual recognition is excellent. From the perspective of more effectively reducing image blur in OLED display devices caused by stacking a light scattering layer, the distance between the adhesive layer having light scattering properties and the color filter is more preferably 600 μm or less, further preferably 500 μm or less, and most preferably the adhesive layer having light scattering properties is in direct contact with the color filter. Figure 7 (a) and Figure 7 (b) shows OLED display devices 400C and 400D of this embodiment. Figure 7 In (a), 41C to 49C are layers constituting the optical laminate 40C, 41C is an adhesive layer, 42C is a resin layer, 43C is a hard coating layer, 44C is an adhesive layer, 45C is a glass layer, 46C is an adhesive layer having light scattering properties, 47C is a resin layer, 48C is a hard coating layer, and 49C is an anti-reflection layer. 15C is disposed on the visual recognition side (on the Figure 7 In the color filter (upper side in (a), the distance d (μm) between the adhesive layer 46C having light scattering properties and the color filter 15C is 700 μm or less. Figure 7 In (b), 41D to 49D are layers constituting the optical laminate 40D, 41D is an adhesive layer having light scattering properties, 42D is a resin layer, 43D is a hard coating layer, 44D is an adhesive layer, 45D is a glass layer, 46D is an adhesive layer, 47D is a resin layer, 48D is a hard coating layer, and 49D is an anti-reflection layer. 15D is disposed on the visual recognition side of the OLED display panel 40D (on the Figure 7 (b) shows the upper side of the color filter. The light-scattering adhesive layer 41D is in direct contact with the color filter 15D. That is, the distance between the light-scattering adhesive layer 41D and the color filter 15D is 0 μm. This effectively suppresses color shift and interference unevenness caused by the OLED display device 400D.

[0224] It should be noted that in Figure 7 (a) and Figure 7In the OLED display devices 400C and 400D shown in (b), 48C and 48D may also be anti-glare layers, or an anti-glare layer may be present between the hard coating layer 48C and the anti-reflection layer 49C, or between the hard coating layer 48D and the anti-reflection layer 49D.

[0225] As another preferred embodiment of the present invention, Figure 2 In the figure, 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coating layer, 24 is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 is a resin layer, 28 is an anti-glare layer, and 29 is an anti-reflection layer. At least one of the adhesive layers 21, 24, and 26 has light scattering properties. Figure 8 FIG shows an OLED display device 500 of this embodiment. Figure 8 In the figure, 51 to 59 are layers constituting the optical laminate 50: 51 is an adhesive layer, 52 is a resin layer, 53 is a hard coat layer, 54 is an adhesive layer, 55 is a glass layer, 56 is an adhesive layer, 57 is a resin layer, 58 is an anti-glare layer, and 59 is an anti-reflection layer. At least one of the adhesive layers 51, 54, and 56 has light-scattering properties. The optical laminate 50 having the anti-glare layer 58 suppresses color shift and interference unevenness caused by the OLED display panel 100, resulting in excellent visual recognition of the OLED display device 500.

[0226] As another preferred embodiment of the present invention, Figure 2 In the figure, 21 is an adhesive layer, 22 is a resin layer, 23 is absent, 24 is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 is a resin layer, 28 is a hard coating layer, and 29 is an anti-reflection layer. Alternatively, Figure 2 In the figure, 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coating layer, 24 is an adhesive layer, 25 is a glass layer, 26 is an adhesive layer, 27 is a resin layer, 28 is a hard coating layer, and 29 is an anti-reflection layer. At least one of the adhesive layers 21, 24, and 26 is an adhesive layer having light scattering properties. Figure 9 (a) and Figure 9 (b) shows OLED display devices 600A and 600B of this embodiment. Figure 9 In (a), 61A, 62A, 64A to 69A are layers constituting the optical laminate 60A, 61A is an adhesive layer, 62A is a resin layer, 64A is an adhesive layer, 65A is a glass layer, 66A is an adhesive layer, 67A is a resin layer, 68A is a hard coat layer, and 69A is an anti-reflection layer. At least one of the adhesive layers 61A, 64A, and 66A is an adhesive layer having light scattering properties. In addition, Figure 9In (b), 61B to 69B are layers constituting the optical laminate 60B, 61B is an adhesive layer, 62B is a resin layer, 63B is a hard coating layer, 64B is an adhesive layer, 65B is a glass layer, 66B is an adhesive layer, 67B is a resin layer, 68B is a hard coating layer, and 69B is an anti-reflection layer. At least one of the adhesive layers 61B, 64B, and 66B is an adhesive layer having light scattering properties. Figure 9 In (a), the resin layer 62A and the glass layer 65A are bonded together by the adhesive layer 64A, or Figure 9 In (b), the glass layer 65B and the resin layer 67B are bonded together by an adhesive layer 66B, thereby imparting excellent impact resistance to each of the optical laminates 60A and 60B, even when the optical laminates 60A and 60B do not include a polarizing plate. While the glass layer has excellent impact resistance, it is a raw material that is easily broken and has low bendability. By bonding the glass layer and the resin layer together with an adhesive layer, flexibility and bendability are improved, enabling the OLED display devices 600A and 600B to be used in flexible and foldable devices.

[0227] It should be noted that in Figure 9 (a) and Figure 9 In the OLED display devices 600A and 600B shown in (b), an anti-glare layer may be provided between the hard coat layer 68A and the anti-reflection layer 69A, and between the hard coat layer 48B and the anti-reflection layer 69B.

[0228] As another preferred embodiment of the present invention, Figure 2 In the figure, 21 is an adhesive layer, 22 is a resin layer, 23 is a hard coating layer, 24 is an adhesive layer, 25 and 26 are not present, 27 is a resin layer, 28 is a hard coating layer, and 29 is an anti-reflection layer. One or both of the resin layers 22 and 27 are transparent polyimide layers. At least one of the adhesive layers 21 and 24 is an adhesive layer having light scattering properties. Figure 10 FIG shows an OLED display device 700 of this embodiment. Figure 10 In FIG, 71 to 74 and 77 to 79 are layers constituting the optical laminate 70, 71 is an adhesive layer, 72 is a transparent polyimide layer, 73 is a hard coating layer, 74 is an adhesive layer, 77 is a resin layer, 78 is a hard coating layer, and 79 is an anti-reflection layer. At least one of the adhesive layers 71 and 74 is an adhesive layer having light scattering properties. Figure 10In this case, the optical laminate 70 has a transparent polyimide layer 72 and a hard coat layer 73, whereby excellent impact resistance is imparted even when the optical laminate 70 does not have a polarizing plate. Further, in the present embodiment, the optical laminate 70 does not have a glass layer. The glass layer is a raw material showing high hardness and excellent impact resistance, but has poor workability and is difficult to be used for large displays used in PCs, tablet computers, etc. By laminating the transparent polyimide layer and the hard coat layer, high hardness equivalent to that of the glass layer can be achieved and the workability is also excellent, and thus it can be applied to large displays used in PCs, tablet computers, etc.

[0229] In Figure 10 In the embodiment shown, it is preferable to form an intermediate layer (compatibilizing layer) (not shown) between the transparent polyimide layer 72 and the hard coat layer 73. By forming an intermediate layer (compatibilizing layer) between the transparent polyimide layer 72 and the hard coat layer 73, the adhesion between the transparent polyimide layer 72 and the hard coat layer 73 is improved. In this case, the shear fracture strength between the transparent polyimide layer 72 and the hard coat layer 73 is preferably 20 MPa or more.

[0230] Examples

[0231] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited by any of these examples.

[0232] Example 1

[0233] <OLED display device>

[0234] An OLED display device was prepared by peeling off the optical film laminated on the visual recognition side of a 4K OLED display (model: EPS 269Q 015A) manufactured by JOLED, Inc.

[0235] <Formation of hard coat layer>

[0236] A UV-curable multifunctional acrylic resin composition (trade name "Z-850-50H-D", manufactured by Aica Industries, Ltd., solid content concentration: 44% by weight), 4 parts by weight of a photopolymerization initiator (trade name "Omnirad 2959", manufactured by IGM Resins Itaila Srl), and 0.05 parts by weight of a leveling agent (trade name "LE-303", manufactured by Kyoeisha Chemical Co., Ltd.) were mixed to obtain a mixed solution. Methyl isobutyl ketone was then added to the obtained mixed solution to obtain a hard coat layer-forming composition having a solid content concentration of 40% by weight. The hard coat layer-forming composition was then applied to one surface of a polyethylene terephthalate film (product name "DIAFOILS100", manufactured by Mitsubishi Chemical Co., Ltd., refractive index: 1.65) serving as a transparent film substrate to form a coating film. Next, the coating was dried by heating at 80°C for 60 seconds and then cured by ultraviolet irradiation. During the ultraviolet irradiation, a high-pressure mercury lamp was used as the light source, ultraviolet rays with a wavelength of 365 nm were used, and the cumulative light intensity was set to 300 mJ / cm 2 Thus, a hard coating layer with a thickness of 3 μm was formed on the PET film.

[0237] <Surface treatment of hard coating>

[0238] Next, a roll-to-roll plasma treatment apparatus was used to plasma-treat the surface of the hard-coated PET film while conveying it under a vacuum atmosphere of 1.0 Pa. During the plasma treatment, argon was used as the inert gas, and the discharge power was set to 150 W. This produced an optical film comprising a PET film and a plasma-treated hard-coated layer.

[0239] <Formation of Primer Layer>

[0240] Next, the heated optical film was introduced into a roll-to-roll sputtering film forming apparatus, and the pressure in the film forming chamber was reduced to 1×10 -4 Pa. Subsequently, while conveying the optical film, argon and oxygen were introduced at a volume ratio of 100:10, and the surface temperature of the film-forming roller was set to -8°C. A 1.5nm-thick ITO layer (undercoat) was formed on the hard coat layer by sputtering. For the formation of the undercoat layer, an ITO target containing indium oxide and tin oxide at a weight ratio of 90:10 was used as the target material. Furthermore, during sputtering, the power supply was set to an MFAC power supply, the discharge power was set to 2.5kW, and the pressure in the film-forming chamber was set to 0.2Pa.

[0241] <Formation of Antireflection Layer>

[0242] After forming the primer layer, a roll-to-roll sputtering system was used to deposit the optical film onto the primer layer. A first layer of 12nm thick Nb2O5 (refractive index: 2.32), a second layer of 29nm thick SiO2 (refractive index: 1.46), a third layer of 107nm thick Nb2O5, and a fourth layer of 81nm thick SiO2 were sequentially deposited on the primer layer. This resulted in a four-layer antireflection layer (first, second, third, and fourth layers) formed on the primer layer. During the deposition of each of the first, second, third, and fourth layers, the deposition roll surface temperature was set to -8°C, the power supply was set to an MFAC power source, and the pressure within the deposition chamber was set to 0.7 Pa. For the deposition of the first layer, a Nb target was used, argon and oxygen were introduced at a volume ratio of 100:5, and the discharge power was set to 10.5kW. For the second layer, a Si target was used, argon and oxygen were introduced at a volume ratio of 100:30, and the discharge power was set to 14 kW. For the third layer, a Nb target was used, argon and oxygen were introduced at a volume ratio of 100:13, and the discharge power was set to 22 kW. For the fourth layer, a Si target was used, argon and oxygen were introduced at a volume ratio of 100:30, and the discharge power was set to 12 kW.

[0243] <Formation of Antifouling Layer>

[0244] A 12 nm thick antifouling layer was formed on the antireflection layer by vacuum deposition using a dried and solidified alkoxysilane compound containing a perfluoropolyether skeleton (trade name "SHIN-ETSU SUBELYN KY1903-1," manufactured by Shin-Etsu Chemical Co., Ltd.) as a vapor deposition source. The heating temperature of the vapor deposition source was set to 260°C. This resulted in an optical laminate with an antifouling layer comprising a PET film, a hard coat layer, a primer layer, an antireflection layer, and an antifouling layer.

[0245] <Preparation of Acrylic Polymer Solution>

[0246] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser, 94.9 parts by weight of butyl acrylate (BA), 5 parts by weight of acrylic acid (AA), 0.1 parts by weight of 4-hydroxybutyl acrylate (4-HBA), and 0.1 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator (monomer concentration 50% by weight) were added together with 100 parts by weight of ethyl acetate. Nitrogen was introduced while slowly stirring for nitrogen replacement. The liquid temperature in the flask was then maintained at approximately 55°C and a polymerization reaction was carried out for 8 hours, thereby preparing a solution of an acrylic polymer having a weight-average molecular weight (Mw) of 2.02 million and an Mw / Mn ratio of 3.2.

[0247] <Preparation of Adhesive Composition>

[0248] To 100 parts by weight of the solid content of the acrylic polymer solution, 0.6 parts by weight of an isocyanate crosslinking agent (trade name "CORONATEL", Tosoh Corporation) and 29 parts by weight of silicone resin fine particles (trade name "Tospearl 145", manufactured by Momentive Advanced Materials Japan Co., Ltd., refractive index 1.43, volume average particle size 4 μm) as light scattering fine particles were added to prepare an adhesive composition (solid content 13.2% by weight).

[0249] <Production of Optical Laminated Body>

[0250] The pressure-sensitive adhesive composition was applied to the surface of the antifouling layer-free substrate film to form a pressure-sensitive adhesive layer to a thickness of 23 μm after drying, thereby producing an optical laminate.

[0251] <Production of OLED Display Device with Optical Laminate>

[0252] The optical laminate was laminated on the OLED display device via an acrylic pressure-sensitive adhesive layer so that the antifouling layer of the optical laminate faced the viewing side, thereby producing an OLED display device with an optical laminate.

[0253] Example 2

[0254] An optical layered body and an OLED display device with the optical layered body were produced in the same manner as in Example 1, except that the thickness of the third layer in the antireflection layer formation step was changed to 90 nm.

[0255] Example 3

[0256] An optical layered body and an OLED display device with the optical layered body were produced in the same manner as in Example 1, except that the thickness of the third layer in the antireflection layer formation step was changed to 70 nm.

[0257] Example 4

[0258] An optical layered body and an OLED display device with the optical layered body were produced in the same manner as in Example 1, except that the thickness of the third layer in the antireflection layer formation step was changed to 50 nm.

[0259] Example 5

[0260] Polystyrene microparticles (trade name "Techpolymer SSX-302 ABE", manufactured by Sekisui Chemicals Co., Ltd., with a volume average particle size of 2 μm and a refractive index of 1.59) were used as light-scattering microparticles in the adhesive composition. The amount of polystyrene microparticles was set to 7.3 parts by weight to form an adhesive layer. Otherwise, an optical laminate and an OLED display device with the optical laminate were prepared in the same manner as in Example 1.

[0261] Example 6

[0262] An optical laminate and an OLED display device with an optical laminate were prepared in the same manner as in Example 4, except that polystyrene microparticles (trade name "Techpolymer SSX-302 ABE", manufactured by Sekisui Chemicals Co., Ltd., with a volume average particle size of 2 μm and a refractive index of 1.59) were used as light-scattering microparticles in the adhesive composition, and their content was set to 7.3 parts by weight to form an adhesive layer.

[0263] Example 7

[0264] An optical laminate and an OLED display device with the optical laminate were produced in the same manner as in Example 1, except that the amount of silicone resin fine particles in the adhesive composition was changed to 7.9 parts by weight and the adhesive layer was formed.

[0265] Comparative Example 1

[0266] An optical laminate and an OLED display device with the optical laminate were produced in the same manner as in Example 1 except that the surface treatment of the hard coat layer, the formation of the primer layer, the formation of the antireflection layer, and the formation of the antifouling layer were not performed.

[0267] Comparative Example 2

[0268] An optical laminate and an OLED display device with the optical laminate were produced in the same manner as in Example 1, except that the light-scattering fine particles were not added to the adhesive composition to form the adhesive layer.

[0269] Comparative Example 3

[0270] An optical laminate and an OLED display device with the optical laminate were produced in the same manner as in Comparative Example 1, except that the light-scattering fine particles were not added to the adhesive composition to form the adhesive layer.

[0271] <Evaluation>

[0272] The following evaluations were performed on the OLED display devices with optical laminates produced in Examples and Comparative Examples. The results are shown in Table 1.

[0273] (1) Haze value

[0274] The pressure-sensitive adhesive layers produced in Examples and Comparative Examples were measured using a haze meter (trade name "HN-150", manufactured by Murakami Color Science Laboratory Co., Ltd.) according to the method specified in JIS K7136.

[0275] (2) Rf1, Rf2, Rp1, Rp2

[0276] The reflectivity of the optical laminate at wavelengths from 380 nm to 780 nm was measured using a spectrophotometer manufactured by Hitachi High-Technologies Corporation. Next, the reflectivity of the surface of the OLED display device from which the optical film was removed, after the optical film laminated on the viewing side of a 4K OLED display manufactured by JOLED Corporation (model number: EPS 269Q 015A) was removed, was measured using a spectrophotometer "CM-2600d" manufactured by Konica Minolta Co., Ltd., at wavelengths from 380 nm to 780 nm. The first peak wavelength WL1 (nm) and the second peak wavelength WL2 (nm) were calculated. The first peak is the maximum value within the wavelength range of 380 nm to 455 nm, and the second peak is the maximum value within the wavelength range of 460 nm to 530 nm. The reflectances of the OLED display at the first peak wavelength WL1 (nm) and the second peak wavelength WL2 (nm) were denoted as Rp1 and Rp2, respectively. The reflectances of the optical laminate at the first peak wavelength WL1 (nm) and the second peak wavelength WL2 (nm) were calculated as Rf1 and Rf2, respectively. It should be noted that the reflectances of the optical laminates in Examples 1 to 7 and Comparative Example 2 correspond to the reflectances of the antireflection layer.

[0277] (3) Color shift

[0278] The OLED display devices with optical laminates obtained in Examples and Comparative Examples were made to display a white screen, and the chromaticity x and y at azimuth angles of 0° to 360° were measured at 1° intervals under the condition of a polar angle of 70° using a luminance meter (trade name "Conoscope", manufactured by AURONIC-MELCHERS). The chromaticity at each angle was defined as x. deg 、y deg When the chromaticity change parameter at each angle is calculated to be Δx=(0.32-x deg ),Δy=(0.34-y deg ). In addition, when the sum of the chromaticity parameters Δx and Δy at the polar angle of 70° and the azimuth angle of 0° to 360° are respectively set to SUMΔx and SUMΔy, {(SUMΔx) 2 +(SUMΔy) 2} (1 / 2) As a color shift.

[0279] (4) Uneven interference

[0280] The OLED display device with an optical laminate obtained in the examples and comparative examples was set to a non-lit state. When a three-wavelength fluorescent lamp was lit at a distance of 30 cm from the OLED display device with the optical laminate, the interference unevenness on the surface of the OLED display device with the optical laminate was visually observed and judged according to the following criteria.

[0281] ◎: No interference unevenness can be visually detected

[0282] ○: Interference unevenness is barely perceptible

[0283] ×: Interference unevenness can be clearly visually recognized

[0284] (5) White blur

[0285] The OLED display device with an optical laminate obtained in the examples and comparative examples was set to a non-lit state. When a three-wavelength fluorescent lamp was lit at a distance of 30 cm from the OLED display device with the optical laminate, the white blur on the surface of the OLED display device with the optical laminate was visually observed and judged according to the following criteria.

[0286] ◎: No white blur can be seen

[0287] ○: White blur is barely perceptible

[0288] △: White blur can be slightly seen

[0289] ×: White blur can be clearly visually recognized

[0290]

[0291] Hereinafter, modifications of the present invention will be described.

[0292] [Supplementary Note 1] An optical laminate for an OLED display device, the optical laminate for an OLED display device being used for an OLED display device in which only an optical element having a polarization degree of 95% or less is laminated on a visual recognition side of the OLED element, wherein the optical element comprises at least an antireflection layer and an adhesive layer, at least one of the adhesive layers having light scattering properties, and wherein, in a reflectance spectrum of the OLED display device in a state where the optical laminate for the OLED display device is not laminated, the maximum reflectance within a wavelength range of 380 nm to 455 nm is defined as Rp1, and the maximum reflectance within a wavelength range of 460 nm to 530 nm is defined as Rp2, the reflectance of the antireflection layer at the wavelength of Rp1 is defined as Rf1, and the reflectance of the antireflection layer at the wavelength of Rp2 is defined as Rf2, and the haze value of the adhesive layer having light scattering properties is defined as H%, the value of H / {[Rf1 / Rp1]+[Rf2 / Rp2]} is 200 or greater.

[0293] [Supplementary Note 2] The optical laminate for an OLED display device according to Supplementary Note 1, wherein the antireflection layer has a water contact angle of 100° or greater.

[0294] [Supplementary Note 3] The optical laminate for an OLED display device according to Supplementary Note 1 or 2, wherein the antireflection layer has a water contact angle of 90° or greater after an eraser test.

[0295] [Supplementary Note 4] The optical laminate for an OLED display device according to any one of Supplementary Notes 1 to 3, wherein the antireflection layer is composed of an inorganic substance.

[0296] [Note 5] The optical laminate for an OLED display device according to any one of Notes 1 to 4, wherein the adhesive layer with light scattering properties is arranged on at least one side of the resin layer, and the adhesive layer with light scattering properties contains light scattering particles dispersed in the adhesive layer, and when the refractive index of the resin layer is set to n1, the refractive index of the adhesive of the adhesive layer with light scattering properties is set to n2, and the refractive index of the light scattering particles is set to n3, n1>n2>n3 is satisfied.

[0297] [Supplementary Note 6] The optical laminate for an OLED display device according to Supplementary Note 5, wherein the volume average particle size of the light scattering fine particles is 1 μm to 5 μm.

[0298] [Supplementary Note 7] The optical laminate for an OLED display device according to Supplementary Note 5 or 6, wherein the light-scattering fine particles are silicone resin.

[0299] [Supplementary Note 8] The optical laminate for an OLED display device according to any one of Supplementary Notes 1 to 7, wherein the pressure-sensitive adhesive layer having light scattering properties has a haze value H of 20% to 90%.

[0300] Description of labels

[0301] 100 OLED display panels

[0302] 10R red OLED layer

[0303] 10G green OLED layer

[0304] 10B blue OLED layer

[0305] 11a Transparent electrode (cathode)

[0306] 11b back electrode (anode)

[0307] 12R red OLED element

[0308] 12G green OLED component

[0309] 12B blue OLED element

[0310] 13 substrates

[0311] 14 TFT layer

[0312] 15 color filters

[0313] 15R red coloring layer

[0314] 15G green coloring layer

[0315] 15B blue coloring layer

[0316] 16 black matrix layers

[0317] W external light

[0318] G reflected light

[0319] C1 first light path (direct light)

[0320] C2 second optical path (reflected light)

[0321] 17 bonding layer

[0322] 200, 300A, 300B, 400A, 400B, 400C, 400D, 500, 600A, 600B, 700 OLED display devices

[0323] 20, 30A, 30B, 40A, 40B, 40C, 40D, 50, 60A, 60B, 70 optical laminates

[0324] 21 Adhesive layer or adhesive layer

[0325] 22 resin layer, glass layer or impact absorbing layer

[0326] 23Hard coating or anti-glare layer

[0327] 24 adhesive layer or adhesive layer

[0328] 25 resin layer, glass layer or impact absorbing layer

[0329] 26 Adhesive layer or adhesive layer

[0330] 27 resin layer, glass layer or impact absorbing layer

[0331] 28Hard coating or anti-glare layer

[0332] 29 Anti-reflection layer

[0333] 34A adhesive layer

[0334] 35A glass layer

[0335] 36A Adhesive layer with light scattering properties

[0336] 37A resin layer

[0337] 38A hard coating

[0338] 39A anti-reflection layer

[0339] 31B adhesive layer

[0340] 32B resin layer

[0341] 33B hard coating

[0342] 34B adhesive layer

[0343] 35B glass layer

[0344] 36B Adhesive layer with light scattering properties

[0345] 37B resin layer

[0346] 38B hard coating

[0347] 39B anti-reflection layer

[0348] 46A Adhesive layer with light scattering properties

[0349] 47A resin layer

[0350] 48A hard coating

[0351] 49A anti-reflection layer

[0352] 15A color filter

[0353] 44B Adhesive layer with light scattering properties

[0354] 45B glass layer

[0355] 46B adhesive layer or adhesive layer

[0356] 47B resin layer

[0357] 48B hard coating

[0358] 49B anti-reflection layer

[0359] 15B color filter

[0360] 41C adhesive layer

[0361] 42C resin layer

[0362] 43C hard coating

[0363] 44C adhesive layer

[0364] 45C glass layer

[0365] 46C Adhesive layer with light scattering properties

[0366] 47C resin layer

[0367] 48C hard coating

[0368] 49C anti-reflection layer

[0369] 15C color filter

[0370] 41D Adhesive layer with light scattering properties

[0371] 42D resin layer

[0372] 43D hard coating

[0373] 44D adhesive layer

[0374] 45D glass layer

[0375] 46D adhesive layer

[0376] 47D resin layer

[0377] 48D hard coating

[0378] 49D anti-reflection layer

[0379] 15D color filter

[0380] 51 adhesive layer

[0381] 52 resin layer

[0382] 53 hard coating

[0383] 54 adhesive layer

[0384] 55 glass layers

[0385] 56 adhesive layer

[0386] 57 resin layer

[0387] 58 anti-glare layer

[0388] 59 anti-reflection layer

[0389] 61A adhesive layer

[0390] 62A resin layer

[0391] 64A adhesive layer

[0392] 65A glass layer

[0393] 66A adhesive layer

[0394] 67A resin layer

[0395] 68A hard coating

[0396] 69A anti-reflection layer

[0397] 61B adhesive layer

[0398] 62B resin layer

[0399] 63B hard coating

[0400] 64B adhesive layer

[0401] 65B glass layer

[0402] 66B adhesive layer

[0403] 67B resin layer

[0404] 68B hard coating

[0405] 69B anti-reflection layer

[0406] 71 adhesive layer

[0407] 72 transparent polyimide layer

[0408] 73 hard coating

[0409] 74 adhesive layer

[0410] 77 resin layer

[0411] 78 hard coating

[0412] 79 anti-reflection layer

Claims

1. An optical laminate for an OLED display device, wherein the optical laminate is used for an OLED display device in which only an optical element having a polarization degree of 95% or less is laminated on a visual recognition side of an OLED element, wherein: The optical element comprises at least an anti-reflection layer and an adhesive layer, At least one of the adhesive layers has light scattering properties, In the reflectance spectrum of the OLED display device in a state where the optical laminate for an OLED display device is not laminated, the maximum reflectance in the wavelength range of 380 nm to 455 nm is denoted as Rp1, the maximum reflectance in the wavelength range of 460 nm to 530 nm is denoted as Rp2, the reflectance of the antireflection layer at the wavelength of Rp1 is denoted as Rf1, the reflectance of the antireflection layer at the wavelength of Rp2 is denoted as Rf2, and the haze value of the adhesive layer having light scattering properties is denoted as H%, The value of H / {[Rf1 / Rp1]+[Rf2 / Rp2]} is 200 or more.

2. The optical laminate for an OLED display device according to claim 1, wherein The water contact angle of the anti-reflection layer is greater than 100°.

3. The optical laminate for an OLED display device according to claim 1 or 2, wherein: The water contact angle of the anti-reflection layer after an eraser test is greater than 90°.

4. The optical laminate for an OLED display device according to claim 1 or 2, wherein: The anti-reflection layer is made of inorganic matter.

5. The optical laminate for an OLED display device according to claim 1 or 2, wherein: The adhesive layer having light scattering properties is provided on at least one side of the resin layer. The adhesive layer having light scattering properties comprises light scattering fine particles dispersed in the adhesive layer. When the refractive index of the resin layer is n1, the refractive index of the binder of the binder layer having light scattering properties is n2, and the refractive index of the light scattering fine particles is n3, n1>n2>n3 is satisfied.

6. The optical laminate for an OLED display device according to claim 5, wherein: The volume average particle size of the light scattering fine particles is 1 μm to 5 μm.

7. The optical laminate for an OLED display device according to claim 5, wherein: The light scattering particles are silicone resin.

8. The optical laminate for an OLED display device according to claim 1 or 2, wherein: The adhesive layer having light scattering properties has a haze value H of 20% to 90%.

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