Optical laminate and polarizing plate, image display panel, and image display device using optical laminate

Abstract

The present invention provides an optical laminate with excellent antifouling properties, as well as a polarizing plate, an image display panel, and an image display device using the same. The optical laminate has at least one functional layer on a substrate, wherein the optical laminate has a first surface, which is the surface on the functional layer side, and a second surface, which is the surface on the substrate side, the functional layer includes a first functional layer, the surface of the first functional layer on the opposite side from the substrate is the first surface, the first functional layer contains a silicone material, the ratio of fluorine elements to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is 0.5 at% or less, and for the first surface, the average value Fave of the adsorption force measured using an atomic force microscope is 2.0 nN or more, and the coefficient of variation FCV of the adsorption force is 0.50 or less.

Description

Optical laminate, and polarizing plate, image display panel, and image display device using said optical laminate

[0001] The present disclosure relates to an optical laminate, and a polarizing plate, an image display panel, and an image display device using the optical laminate.

[0002] In components such as display devices, such as liquid crystal display devices, organic EL display devices, and micro LED display devices, and showcases, an optical laminate having an anti-reflection layer for improving visibility and a hard coat layer for improving mechanical strength, such as scratch resistance, may be provided. Since the above optical laminate is used by being placed on the outermost surface of each component, the surface of the optical laminate may become stained with dirt such as sebum, food, oil-based marking pens, etc. For this reason, an anti-fouling treatment may be applied to the outermost surface of the optical laminate to improve the ease of wiping off the dirt.

[0003] Patent Documents 1 and 2 disclose that in an antireflection member having a low refractive index layer on a transparent substrate, the surface of the low refractive index layer can be made smoother and furthermore the slipperiness and antifouling properties of the low refractive index layer can be improved by adding a leveling agent as an additive to a resin composition for forming the low refractive index layer located on the outermost surface.

[0004] International Publication No. WO 2020 / 100926 International Publication No. WO 2020 / 145375

[0005] As the leveling agent, fluorine-based leveling agents and silicone-based leveling agents are widely used. Fluorine-based leveling agents are advantageous in that they can impart excellent antifouling properties, but in recent years, there has been a tendency to avoid their use from the viewpoint of reducing the burden on the environment, etc. In consideration of the environmental burden, it is preferable to use silicone-based leveling agents, but there has been a demand for obtaining antifouling properties that are not inferior to those obtained when fluorine-based leveling agents are used.

[0006] An object of the present disclosure is to provide an optical laminate having excellent antifouling properties, and a polarizing plate, an image display panel, and an image display device using the same.

[0007] As a result of research, the inventors have found that the adhesive force measured using an atomic force microscope on the surface of a functional layer containing a silicone-based material (silicone-based leveling agent) is related to the antifouling properties of the functional layer. The adhesive force measured using an atomic force microscope is thought to correlate with the degree of affinity between the surface of the functional layer and the tip of the probe used for measurement. The inventors have also found that when the adhesive force measured using the probe tip is within a predetermined range, the functional layer containing a silicone-based material has excellent antifouling properties, which led to the present invention.

[0008] In order to solve the above problems, the present disclosure provides the following items <1> to <17>: <1> An optical laminate having at least one functional layer on a substrate, the optical laminate having a first surface that is a surface on the functional layer side and a second surface that is a surface on the substrate side, the functional layer including a first functional layer, the surface of the first functional layer opposite to the substrate being the first surface, the first functional layer including a silicone-based material, a ratio of fluorine element to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy being 0.5 at % or less, and an average adsorption force F of the first surface measured using an atomic force microscope under the following measurement conditions: ａｖｅ is 2.0 nN or more, and the coefficient of variation of the adsorptive force F ＣＶ [Measurement conditions] Probe: single crystal Si, probe length 10 μm to 15 μm, curvature radius 8 nm, spring constant 0.2 N / m Measurement mode: force curve Measurement area: 10 μm × 10 μm Number of pixels: 32 × 32 Measurement points: each pixel (1024 points) Scanning speed: 2 Hz <2> Average value F of the suction force ａｖｅ <3> The optical laminate according to <1>, wherein the coefficient of variation F of the adsorptive force is 20.0 nN or less. ＣＶ <4> The optical laminate according to <1> or <2>, wherein the ratio C of silicon element attributable to silicone to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is 0.30 or less. Ｓｉ<5> The optical laminate according to any one of <1> to <3>, wherein the first surface of the first functional layer is rubbed under the following rubbing conditions, and then the average adsorption force F' after rubbing is measured for the first surface after rubbing under the measurement conditions: ａｖｅ is 2.0 nN or more, and the coefficient of variation F' of the adsorptive force after rubbing is ＣＶ <4> The optical laminate according to any one of <1> to <4>, wherein the value of the surface roughness is 4.0 or less. [Rubbing conditions] Scraping material: a cloth soaked in acetone Load: 150 g / cm ２ Number of sliding times: 5 times (one way) <6> The optical laminate according to <5>, wherein a rate of change ΔF of the average value of the adsorptive force represented by the following formula (1) is 25.0% or less. ΔF (%) = (F ａｖｅ -F' ａｖｅ ) / F ａｖｅ × 100 (1) <7> The ratio of silicon element attributable to silicone to all elements obtained by analyzing the first surface of the first functional layer before rubbing by X-ray photoelectron spectroscopy is C Ｓｉ and C' is the ratio of silicon element attributable to silicone to all elements obtained by analyzing the first surface of the first functional layer after rubbing by X-ray photoelectron spectroscopy. Ｓｉ When expressed as: the rate of change ΔC of the silicon atom ratio represented by the following formula (2) Ｓｉ <5> or <6>, wherein ΔC is 25.0% or less. Ｓｉ (%) = (C Ｓｉ -C' Ｓｉ ) / C Ｓｉ ×100 (2) <8> The optical laminate according to any one of <1> to <7>, wherein the silicone-based material is a silicone-based leveling agent. <9> The optical laminate according to any one of <1> to <8>, wherein the first functional layer is a first refractive index layer, and the first refractive index layer contains hollow silica particles and solid silica particles. <10> The optical laminate according to <9>, wherein the functional layer includes a second functional layer between the first functional layer and the substrate, and the second functional layer is a second refractive index layer having a higher refractive index than the first refractive index layer that is the first functional layer.

[0009] <11> An optical laminate having at least one functional layer on a substrate, the optical laminate having a first surface that is the surface on the functional layer side and a second surface that is the surface on the substrate side, the functional layer including a first functional layer, the surface of the first functional layer opposite to the substrate being the first surface, the first functional layer including a silicone-based leveling agent having dimethylpolysiloxane in its main chain and a silicone-based leveling agent having acrylic in its main chain, the ratio of fluorine element to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is 0.5 at% or less. <12> The ratio of silicon element attributable to silicone to all elements obtained by analyzing the first surface of the first functional layer before rubbing by X-ray photoelectron spectroscopy is C Ｓｉ The first surface of the first functional layer is rubbed under the following rubbing conditions, and the ratio of silicon element attributable to silicone to all elements obtained by analyzing the first surface of the first functional layer after rubbing by X-ray photoelectron spectroscopy is represented by C' Ｓｉ When expressed as: the rate of change ΔC of the silicon atom ratio represented by the following formula (2) Ｓｉ <11> The optical layered body according to <11>, wherein ΔC is 25.0% or less. Ｓｉ (%) = (C Ｓｉ -C' Ｓｉ ) / C Ｓｉ × 100 (2) [Rubbing conditions] Rubbing material: acetone-soaked cloth Load: 150 g / cm ２ Number of sliding times: 5 times (one way) <13> The optical laminate according to <11> or <12>, wherein the first functional layer is a first refractive index layer, and the first refractive index layer contains hollow silica particles and solid silica particles. <14> The optical laminate according to <13>, wherein the functional layer includes a second functional layer between the first functional layer and the substrate, and the second functional layer is a second refractive index layer having a higher refractive index than the first refractive index layer that is the first functional layer.

[0010] <15> A polarizing plate having a polarizer, a first transparent protective plate arranged on one side of the polarizer, and a second transparent protective plate arranged on the other side of the polarizer, wherein one of the first transparent protective plate and the second transparent protective plate is the optical laminate according to any one of <1> to <14>, and the surface of the optical laminate facing the first functional layer faces the side opposite to the polarizer. <16> An image display panel having a display element and an optical film arranged on the light emission surface side of the display element, wherein the optical film includes the optical laminate according to any one of <1> to <14>, and the surface of the optical laminate facing the first functional layer faces the side opposite to the display element. <17> An image display device including the image display panel according to <16>.

[0011] According to the present disclosure, an optical laminate having excellent antifouling properties can be obtained. By using the optical laminate of the present disclosure, a polarizing plate, an image display panel, and an image display device having excellent wipeability against stains caused by fingerprints, marking pens, and the like can be obtained.

[0012] 1 is a cross-sectional schematic view of an optical laminate according to an example of a first embodiment of the present disclosure; 2 is a cross-sectional schematic view of an optical laminate according to an example of a first embodiment of the present disclosure; 3 is a cross-sectional schematic view of an optical laminate according to an example of a first embodiment of the present disclosure;

[0013] Hereinafter, embodiments of the present disclosure will be described. [Optical Laminate] 1. First Embodiment An optical laminate according to a first embodiment of the present disclosure is an optical laminate having at least one functional layer on a substrate, the optical laminate having a first surface that is a surface on the functional layer side and a second surface that is a surface on the substrate side, the functional layer including a first functional layer, the surface of the first functional layer opposite to the substrate being the first surface, the first functional layer including a silicone-based material, the ratio of fluorine element to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy being 0.5 at % or less, and an average adsorption force F of the first surface measured using an atomic force microscope under the following measurement conditions: ａｖｅ is 2.0 nN or more, and the coefficient of variation of the adsorptive force F ＣＶis 0.50 or less. [Measurement conditions] Probe: Single crystal Si, probe length 10 μm to 15 μm, curvature radius 8 nm, spring constant 0.2 N / m Measurement mode: Force curve Measurement area: 10 μm × 10 μm Number of pixels: 32 × 32 Measurement location: Each pixel (1024 locations) Scanning speed: 2 Hz

[0014] 1 to 3 are cross-sectional schematic diagrams of an optical laminate according to an example of the first embodiment of the present disclosure. The optical laminate according to the first embodiment has at least one functional layer on a substrate. The optical laminate 10 illustrated in FIG. 1 is an example in which one functional layer 12 is laminated on a substrate 11. In the configuration of FIG. 1, the functional layer 12 corresponds to the first functional layer. The optical laminate 10 has a first surface 12s, which is the surface on the functional layer 12 side, and a second surface 11s, which is the surface on the substrate 11 side. In other words, the surface of the first functional layer, the functional layer 12, opposite the substrate is the first surface 12s. The first functional layer is the layer located on the outermost surface of the optical laminate opposite the substrate. When the optical laminate according to the first embodiment is applied to an image display device or the like, the first functional layer is located on the user side.

[0015] The functional layer may be configured by stacking multiple layers. In the optical laminate 20 illustrated in Fig. 2, three functional layers 22 are stacked. The functional layer 22 is configured by, in order from the outermost surface of the optical laminate 20, a first functional layer 22-1, a second functional layer 22-2, and a third functional layer 22-3.

[0016] In the first embodiment, another layer such as a primer layer may be provided between the functional layer and the substrate. The optical laminate 30 illustrated in Fig. 3 has a primer layer 33 provided between the functional layer (first functional layer) 32 and the substrate 31.

[0017] 1 to 3 show schematic cross sections. The scale of each layer constituting the optical laminate is shown in a schematic manner for ease of illustration, and differs from the actual scale.

[0018] In the optical laminate according to the first embodiment, the first functional layer contains a silicone-based material, and the ratio of fluorine to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is required to be 0.5 at% or less. A ratio of fluorine to all elements of 0.5 at% or less means that the first functional layer does not substantially contain a fluorine-based material. In other words, the optical laminate according to the first embodiment achieves the desired antifouling properties by having the first functional layer contain a silicone-based material without using a fluorine-based material.

[0019] <Adsorption force> In the optical laminate according to the first embodiment, the average value F of the adsorption force measured on the first surface using an atomic force microscope under the following measurement conditions is ａｖｅ is 2.0 nN or more, and the coefficient of variation of the adsorptive force F ＣＶ must be 0.50 or less. [Measurement conditions] Probe: Single crystal Si, probe length 10 μm to 15 μm, radius of curvature 8 nm, spring constant 0.2 N / m Measurement mode: Force curve Measurement area: 10 μm x 10 μm Number of pixels: 32 x 32 Measurement points: Each pixel (1024 points) Scanning speed: 2 Hz Furthermore, it is preferable that the probe used in measuring the suction force has the following properties: Cantilever length: 450 μm, Resonance frequency: 13 kHz

[0020] Using an atomic force microscope, it is possible to measure a force curve, which is a function of the force acting between the probe and the functional layer surface. From this force curve, the adhesive force corresponding to the affinity between the probe and the functional layer surface can be obtained. There are various probes used in atomic force microscope observations, each with different materials, tip shapes, dimensions, spring constants, etc. Therefore, the adhesive force value measured varies depending on the type of probe. Furthermore, even when the same probe is used, the adhesive force value will also vary if the surface condition within the measurement surface changes.

[0021] The adsorption force is thought to correlate with the affinity between the surface of the functional layer and the tip of the probe used for measurement. The anti-fouling property is thought to be related to the affinity between the surface of the functional layer and stains such as fingerprints (sebum) and oil-based marking pen ink. As a result of evaluating the relationship between the adsorption force of the surface of the functional layer and the anti-fouling property of the functional layer, the inventors found that a functional layer with excellent anti-fouling properties can be obtained when the adsorption force measured using a specific probe is within a specific range. The average value F of the adsorption force measured under the above conditions ａｖｅ The larger the average adsorption force F, the better the antifouling properties of the functional layer, specifically, the better the wiping properties of fingerprints and marking pen ink. ａｖｅ When the average adsorption force F is 2.0 nN or more, an optical laminate having excellent antifouling properties can be obtained. ａｖｅ If the average adsorption force F is less than 2.0 nN, the ability to wipe off dirt (sebum, ink, etc.) adhering to the surface of the functional layer is insufficient, and the dirt may remain. ａｖｅ If the coefficient of variation F of the adsorptive force is less than 2.0 nN, it is not possible to obtain an optical layered body having excellent antifouling properties. ＣＶ is an index for evaluating the in-plane variation of the adsorptive force on the surface of the functional layer. ＣＶ A small coefficient of variation F of the adsorptive force on the surface of the functional layer means that the variation in the adsorptive force is small. ＣＶ When the coefficient of variation F of the adsorptive force is 0.50 or less, the dirt adhering to the surface can be wiped off by rubbing the surface of the functional layer without leaving any part of the dirt remaining on the surface. ＣＶ When the coefficient of variation F is 0.50 or less, an optical layered body having excellent antifouling properties can be obtained. ＣＶ If the coefficient of variation F exceeds 0.50, there tends to be some areas where the adsorption force is large. ＣＶ If exceeds 0.50, the average value F ａｖｅ Even if the surface resistivity is 2.0 nN or more, there will be areas on the surface of the functional layer that are not sufficiently soil-resistant. As a result, when the surface of the functional layer is rubbed, the attached stains may remain in some areas, and the optical laminate will not have excellent soil-resistant properties.

[0022] In addition, if dirt such as dust is attached to the first surface, the dirt is removed, and then the average value F of the adsorption force is calculated. ａｖｅ and coefficient of variation of the adsorption force F ＣＶ shall be measured.

[0023] Average adsorption force F ａｖｅ The upper limit of the average adsorptive force F is preferably 20.0 nN, more preferably 17.0 nN, and even more preferably 15.0 nN. ａｖｅ The lower limit of the average adsorptive force F is preferably 2.5 nN, more preferably 3.0 nN, and even more preferably 3.5 nN. ａｖｅ is preferably 2.0 nN or more and 20.0 nN or less, more preferably 2.0 nN or more and 17.0 nN or less, more preferably 2.0 nN or more and 15.0 nN or less, more preferably 2.5 nN or more and 20.0 nN or less, more preferably 2.5 nN or more and 17.0 nN or less, more preferably 2.5 nN or more and 15.0 nN or less, more preferably 3.0 nN or more and 20.0 nN or less, more preferably 3.0 nN or more and 17.0 nN or less, more preferably 3.0 nN or more and 15.0 nN or less, more preferably 3.5 nN or more and 20.0 nN or less, more preferably 3.5 nN or more and 17.0 nN or less, more preferably 3.5 nN or more and 15.0 nN or less.

[0024] Coefficient of variation of adsorption force F ＣＶ is preferably 0.30 or less, more preferably 0.28 or less, and even more preferably 0.26 or less. ＣＶ Although the lower limit of is not particularly limited, it is preferably 0.05 or more.

[0025] In the first embodiment, the ratio C of silicon element attributable to silicon to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy Ｓｉ It is preferable that the silicon content of the silicon-containing organic compound is 2.5 at % or more and 15.0 at % or less. The "silicon element belonging to the silicone" can be rephrased as the silicon element belonging to the organosilicon compound.Ｓｉ The fact that C is in the above range means that a certain amount of the silicone-based material is present in the surface region of the first functional layer. Ｓｉ By being in the above range, the average value F of the adsorption force ａｖｅ and coefficient of variation F ＣＶ The above range is easily satisfied. Ｓｉ is more preferably 3.0 at% or more and 12.0 at% or less, even more preferably 3.5 at% or more and 10.0 at% or less, and particularly preferably 4.0 at% or more and 8.0 at% or less. Note that the "surface region" in the present disclosure is within the range of the detection region by X-ray photoelectron spectroscopy, and refers to a region from the first surface in the first functional layer to a depth of 10 nm.

[0026] In the functional layer of the first embodiment, the first surface of the first functional layer is rubbed under the following rubbing conditions, and then the average value F' of the adsorption force after rubbing is measured for the first surface after rubbing under the above measurement conditions. ａｖｅ is 2.0 nN or more, and the coefficient of variation F' of the adsorptive force after rubbing is ＣＶ It is preferable that the value of the surface roughness is 4.0 or less. [Rubbing conditions] Rubbing material: acetone-soaked cloth Load: 150 g / cm ２ Number of slides: 5 times (one way)

[0027] In addition, in the functional layer of the first embodiment, it is preferable that the rate of change ΔF of the average value of the adsorptive force expressed by the following formula (1) is 25.0% or less. ΔF (%)=(F ａｖｅ -F' ａｖｅ ) / F ａｖｅ ×100 (1)

[0028] In the present disclosure, "rubbing" corresponds to, for example, when the optical laminate is applied to an image display device or the like, wiping the surface of the functional layer after it has become soiled with sebum, ink, or the like with a cloth, absorbent cotton, a cotton swab, or the like. ａｖｅ Even if the average adsorption force F' is 2.0 nN or more, the adsorption force after rubbing may decrease. The reason for this is presumed to be that the silicone-based material present on the surface of the functional layer is removed by rubbing or the like. In other words, the average adsorption force F' after rubbing ａｖｅA change in the average adsorptive force ΔF of 2.0 nN or more is preferable because the silicone-based material remains even after wiping off dirt, etc., and sufficient antifouling properties can be maintained. Similarly, a change in the average adsorptive force ΔF of 25.0% or less is preferable because it can be said that the loss of the silicone-based material on the surface of the functional layer due to rubbing is suppressed, and excellent antifouling properties can be maintained even after rubbing.

[0029] Coefficient of variation F' of adsorption force after rubbing ＣＶ is an index for evaluating the in-plane variation of the adsorptive force on the surface of the functional layer after rubbing. ＣＶ is the coefficient of variation of the adsorption force before rubbing F ＣＶ This is presumably because the silicone material on the surface of the functional layer is partially removed by rubbing. ＣＶ It is preferable that the value is 4.0 or less, since it can be said that the antifouling properties can be maintained even after wiping off the stains and the like.

[0030] Average value of adsorption force before rubbing F ａｖｅ The average value F' of the adsorptive force after rubbing is preferably in the range described above. ａｖｅ The upper limit of the average adsorption force F' after rubbing is preferably 20.0 nN, more preferably 17.0 nN, and even more preferably 15.0 nN. ａｖｅ The lower limit of the average adsorptive force F is preferably 2.0 nN, more preferably 2.5 nN, and even more preferably 3.0 nN. ａｖｅis preferably 2.0 nN or more and 20.0 nN or less, more preferably 2.0 nN or more and 17.0 nN or less, more preferably 2.0 nN or more and 15.0 nN or less, more preferably 2.5 nN or more and 20.0 nN or less, more preferably 2.5 nN or more and 17.0 nN or less, more preferably 2.5 nN or more and 15.0 nN or less, more preferably 3.0 nN or more and 20.0 nN or less, more preferably 3.0 nN or more and 17.0 nN or less, more preferably 3.0 nN or more and 15.0 nN or less, more preferably 3.5 nN or more and 20.0 nN or less, more preferably 3.5 nN or more and 17.0 nN or less, more preferably 3.5 nN or more and 15.0 nN or less.

[0031] The rate of change ΔF of the average value of the adsorptive force is more preferably 20.0% or less, and even more preferably 15.0% or less. There is no particular restriction on the lower limit of the rate of change ΔF of the average value of the adsorptive force, but it is preferably 1.0%.

[0032] Coefficient of variation of the adsorption force before rubbing F ＣＶ The coefficient of variation F' of the adsorptive force after rubbing is preferably in the range described above. ＣＶ is preferably 3.5 or less, more preferably 3.0 or less, and even more preferably 2.5 or less. ＣＶ Although the lower limit of is not particularly limited, it is preferably 0.2.

[0033] In the first embodiment, the ratio of silicon element attributable to silicone to all elements obtained by analyzing the first surface of the first functional layer before rubbing by X-ray photoelectron spectroscopy is C Ｓｉ and C' is the ratio of silicon element attributable to silicone to all elements obtained by analyzing the first surface of the first functional layer after rubbing by X-ray photoelectron spectroscopy. Ｓｉ When expressed as: the rate of change ΔC of the silicon atom ratio represented by the following formula (2) Ｓｉ is preferably 25.0% or less. Ｓｉ (%) = (C Ｓｉ -C' Ｓｉ ) / CＳｉ ×100 (2)

[0034] ΔC Ｓｉ When ΔC satisfies the above range, it means that the silicone-based material remains on the surface region of the first functional layer even after rubbing. Ｓｉ By satisfying the above range, the average value F' of the adsorption force after rubbing ａｖｅ , coefficient of variation F' of adsorption force after rubbing ＣＶ , and the rate of change ΔF of the average value of the adsorptive force tends to fall within the above range. Ｓｉ is more preferably 30.0% or less, and even more preferably 20.0% or less. Ｓｉ There is no particular restriction on the lower limit of the content, but it is preferably 2.0%.

[0035] The arithmetic mean roughness Ra of the functional layer surface, measured in accordance with JIS B0601:2001, is preferably 1.0 nm or more and 15.0 nm or less, more preferably 4.0 nm or more and 12.0 nm or less, and even more preferably 6.0 nm or more and 11.0 nm or less.

[0036] In the first embodiment, the silicone-based material contained in the first functional layer is preferably a silicone-based leveling agent. Examples of the silicone-based leveling agent used in the first embodiment include a type having dimethylpolysiloxane (PDMS) in the main chain (hereinafter referred to as "PDMS main chain type") and a type having acrylic in the main skeleton (hereinafter referred to as "acrylic main chain type"). In the first embodiment, the surface of the functional layer is preferably a surface having an average adsorption force F ａｖｅ and coefficient of variation of the adsorption force F ＣＶ As long as the range of (a) is satisfied, the PDMS main chain type and the acrylic main chain type may be used alone or in combination. In particular, by using the PDMS main chain type and the acrylic main chain type in combination, the average value of the adsorption force F ａｖｅ and coefficient of variation of the adsorption force F ＣＶ Furthermore, the average value F' of the adsorption force after rubbing tends to satisfy the above range. ａｖｅ , coefficient of variation F' of adsorption force after rubbing ＣＶ, and the rate of change ΔF of the average value of the adsorptive force are likely to fall within the above-mentioned ranges.

[0037] In the first embodiment, the surface of the first functional layer has the average adsorption force F ａｖｅ , coefficient of variation of the adsorption force F ＣＶ , the average value F' of the adsorption force after rubbing ａｖｅ , coefficient of variation F' of adsorption force after rubbing ＣＶ The reason why the ranges of the rate of change ΔF of the average adsorption force and the average adsorption force are more likely to be satisfied is presumed to be as follows. As described below, the first functional layer is formed by applying a resin composition containing a binder resin and a silicone-based leveling agent (a silicone-based material). When the resin composition is applied, the silicone-based leveling agent is oriented toward the upper part of the applied film. In other words, a layer containing the silicone-based leveling agent as a main component is formed on a layer containing the binder resin as a main component. The acrylic main chain type is highly compatible with the binder resin, while the PDMS main chain type tends to have poor compatibility with the binder resin. When a resin composition containing a PDMS main chain type and an acrylic main chain type is applied, a layer of the silicone-based leveling agent containing mainly the PDMS main chain type, which has poor compatibility with the binder resin, is formed near the first surface. Meanwhile, near the interface between the silicone-based leveling agent layer and the binder resin layer, some of the acrylic main chain type is compatible with the binder resin. Because the acrylic main chain type is present near the interface, the PDMS main chain type oriented in the upper layer tends to be distributed approximately uniformly. That is, it is thought that the PDMS main chain type and some of the acrylic main chain type are distributed approximately uniformly in the vicinity of the first surface. When crosslinking is performed in this state, the PDMS main chain type is maintained in an approximately uniform distribution state in the vicinity of the first surface. As a result of the PDMS main chain type being distributed approximately uniformly on the first surface of the first functional layer in this way, the average adsorption force F ａｖｅ and coefficient of variation of the adsorption force F ＣＶIt is considered that the above-mentioned range is easily satisfied. Furthermore, near the interface, the acrylic main chain type is in a state where the binder resin is crosslinked, so a functional layer is formed in which the layer of the silicone leveling agent and the layer of the binder resin are firmly bonded. As a result, the silicone leveling agent (silicone material) is not easily lost even when rubbed and remains on the surface of the functional layer, so the average value F' of the adsorption force after rubbed ａｖｅ , coefficient of variation F' of adsorption force after rubbing ＣＶ , and the rate of change ΔF of the average value of the adsorption force are likely to satisfy the above-mentioned range. When the PDMS-based main chain type is used alone, the silicone-based leveling agent is unevenly distributed in the thickness direction near the first surface of the first functional layer, but due to poor compatibility with the binder resin, it may be unevenly distributed in the in-plane direction. In this way, when the PDMS-based main chain type is unevenly distributed in the in-plane direction of the first functional layer, the variation in the adsorption force increases, and the coefficient of variation F of the adsorption force ＣＶ When the acrylic main chain type is used alone, the acrylic main chain type and the binder resin become compatible with each other, and the amount of the silicone-based leveling agent present on the first surface of the first functional layer tends to decrease. As a result, the adsorption force decreases, and the average adsorption force F ａｖｅ It may be difficult to satisfy the above range.

[0038] 2. Second Embodiment An optical laminate according to a second embodiment of the present disclosure is an optical laminate having at least one functional layer on a substrate, wherein the optical laminate has a first surface that is a surface on the functional layer side and a second surface that is a surface on the substrate side, the functional layer includes a first functional layer, the first surface is a surface of the first functional layer opposite to the substrate, the first functional layer includes a silicone-based leveling agent having dimethylpolysiloxane in its main chain and a silicone-based leveling agent having acrylic in its main chain, and a ratio of elemental fluorine to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is 0.5 at % or less.

[0039] The optical laminate according to the second embodiment of the present disclosure has a layer structure similar to the layer structure described in the first embodiment. That is, the cross-sectional schematic diagrams of Figures 1 to 3 are also applicable to the second embodiment.

[0040] In the optical laminate according to the second embodiment, the ratio of fluorine element to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy must be 0.5 at% or less. A ratio of fluorine element to all elements of 0.5 at% or less means that the first functional layer does not substantially contain a fluorine-based material. In other words, the optical laminate according to the second embodiment achieves the desired antifouling properties by including a silicone-based leveling agent in the first functional layer without using a fluorine-based material.

[0041] <Silicone-based leveling agent of the second embodiment> In the second embodiment, the first functional layer is required to contain a silicone-based leveling agent (PDMS main chain type) having dimethylpolysiloxane (PDMS) in the main chain and a silicone-based leveling agent (acrylic main chain type) having acrylic in the main chain. Furthermore, in the optical laminate according to the second embodiment, the ratio of fluorine elements to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is required to be 0.5 at% or less. That is, the optical laminate according to the first embodiment does not use a fluorine-based material, and the first functional layer contains the above-mentioned two types of silicone-based leveling agents, thereby achieving good antifouling properties.

[0042] In the second embodiment, the reason why good antifouling properties are obtained by including two types of silicone-based leveling agents, a PDMS main chain type and an acrylic main chain type, is presumed to be as follows. As described above, by forming the first functional layer by applying a resin composition containing a binder resin and a silicone-based leveling agent, a layer mainly composed of a silicone-based leveling agent is formed on a layer mainly composed of a binder resin. Within the layer mainly composed of a silicone-based leveling agent, the PDMS main chain type and some of the acrylic main chain type are distributed in a substantially uniform mixture near the first surface, and the layer of silicone-based leveling agent and the layer of binder resin are firmly bonded near the interface with the layer mainly composed of a binder resin. The substantially uniform distribution of the PDMS main chain type on the first surface improves the antifouling properties of the functional layer, specifically, the ease of wiping off fingerprints and marking pen ink. Furthermore, by firmly bonding the silicone-based leveling agent layer and the binder resin layer near the interface, the silicone-based leveling agent is less likely to disappear even when the first functional layer is rubbed to wipe off fingerprints or ink, so excellent anti-fouling properties can be maintained even after rubbing. Note that when the first functional layer contains only a PDMS-based main chain type, compatibility with the binder resin is poor, which may result in uneven distribution in the in-plane direction. In this case, it becomes difficult to obtain sufficient anti-fouling properties. Furthermore, there is a concern that the bonding between the silicone-based leveling agent layer and the binder resin layer becomes insufficient, causing the silicone-based leveling agent to disappear upon rubbing, resulting in a decrease in anti-fouling properties. Furthermore, when the first functional layer contains only an acrylic main chain type, the acrylic main chain type and the binder resin are easily compatible, so the amount of silicone-based leveling agent present on the first surface of the first functional layer tends to be reduced. This makes it difficult to obtain sufficient anti-fouling properties.

[0043] Each layer of the optical laminate of the first and second embodiments of the present disclosure will be described in detail below. <Substrate> The substrate serves as a support when forming the functional layer. The substrate is preferably light-transmitting. Specifically, the substrate preferably has a total light transmittance in accordance with JIS K7361-1:1997 of 50% or more, more preferably 80% or more, and even more preferably 90% or more.

[0044] Examples of the material of the substrate include plastic and glass. Glass substrates are harder than plastic substrates, and therefore have the advantage of easily improving the scratch resistance of the functional layer. Examples of glass include alkali-free glass, nitride glass, soda-lime glass, borosilicate glass, and lead glass. Plastic substrates have the advantage that they can reduce the thickness and weight of products to which the optical laminate is applied, such as image display devices. The plastic substrate can be formed from one or more of polyolefin resins such as polyethylene and polypropylene; vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, and ethylene-vinyl alcohol copolymer; polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; acrylic resins such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; styrene resins such as polystyrene; polyamide resins such as nylon 6 or nylon 66; cellulose resins such as triacetyl cellulose; resins such as polycarbonate; polyimide resins; and cycloolefin resins obtained from cycloolefins such as norbornene and dicyclopentadiene.

[0045] The thickness of the substrate is not particularly limited. In the case of a plastic substrate, from the viewpoint of handleability, it is preferably 10 μm or more and 500 μm or less, more preferably 20 μm or more and 400 μm or less, and even more preferably 50 μm or more and 300 μm or less. The plastic substrate may be a plate-like substrate having a thickness of more than 500 μm. In the case of glass, from the viewpoint of handleability, strength, and weight reduction, it is preferably 0.03 mm or more and 5.0 mm or less, more preferably 0.1 mm or more and 3.0 mm or less, and even more preferably 0.3 mm or more and 2.0 mm or less. The substrate is not limited to a flat plate-like substrate, but may also be a three-dimensional substrate having a curved surface or the like. The substrate is not limited to being colorless, but may also be colored.

[0046] <Functional Layer> The functional layer is composed of one or more layers selected from a hard coat layer, an antireflection layer, an antiglare layer, a retardation layer, an adhesive layer, a transparent conductive layer, and an antistatic layer. When the functional layer is composed of multiple layers, the first functional layer, which is the functional layer located on the outermost surface of the optical laminate, is preferably a hard coat layer or an antireflection layer.

[0047] When the optical laminate of the present disclosure is applied to an image display device or the like, it is preferable that the optical laminate has an antireflection layer as a functional layer. The antireflection layer may have a single layer configuration, or may have a configuration in which two or more layers are laminated. When the layer on the opposite side of the antireflection layer from the substrate is the first refractive index layer, the first functional layer is the first refractive index layer. For example, in the case of an optical laminate having the configuration of FIG. 2, the first functional layer 22-1 is the first refractive index layer, the second functional layer 22-2 is the second refractive index layer, and the third functional layer 22-3 is a hard coat layer. The layer configuration of the optical laminate is not limited to FIG. 2. Examples of layer configurations of an optical laminate having a first refractive index layer as the first functional layer include the following: (1) A configuration having a first refractive index layer and a substrate in this order. (2) A configuration having a first refractive index layer, a second refractive index layer, and a substrate in this order. (3) A configuration having a first refractive index layer, a hard coat layer, and a substrate in this order. (4) A configuration having a first refractive index layer, a second refractive index layer, a hard coat layer, and a substrate in this order (FIG. 2).

[0048] The first refractive index layer, which is the first functional layer, is preferably a layer with a low refractive index. The first refractive index layer has a refractive index lower than that of the substrate. The refractive index of the first refractive index layer is preferably 1.40 or less, more preferably 1.35 or less. By setting the refractive index of the first refractive index layer to 1.40 or less, an increase in reflectance at the surface (first surface) of the first refractive index layer can be suppressed, making it easier to improve visibility when applied to an image display device. The lower limit of the refractive index of the first refractive index layer is approximately 1.10. The thickness of the first refractive index layer is preferably 50 nm or more and 120 nm or less, more preferably 80 nm or more and 110 nm or less, and even more preferably 90 nm or more and 105 nm or less. In this specification, the refractive index refers to the refractive index at a wavelength of 589.3 nm.

[0049] In the present disclosure, the functional layer preferably includes a second functional layer between the first functional layer and the substrate, and the second functional layer is a second refractive index layer having a higher refractive index than the first refractive index layer, which is the first functional layer. By further including a second refractive index layer in the optical laminate, the reflectance at the surface (first surface) of the first refractive index layer can be further reduced, making it easier to improve visibility when applied to an image display device. The refractive index of the second refractive index layer is preferably 1.55 or more and 1.85 or less, and more preferably 1.56 or more and 1.75 or less. The thickness of the second refractive index layer is preferably 200 nm or less, and more preferably 50 nm or more and 180 nm or less.

[0050] The hard coat layer is a layer that ensures mechanical strength such as scratch resistance when an antireflection layer is provided. The thickness of the hard coat layer is preferably 0.1 μm or more and 100 μm or less, more preferably 0.5 μm or more and 20 μm or less, and even more preferably 1 μm or more and 10 μm or less. By setting the thickness of the hard coat layer within the above range, scratch resistance can be improved while easily suppressing the occurrence of cracks during processing such as cutting. From the viewpoint of reducing the reflectance of the optical laminate due to interference, the refractive index of the hard coat layer is preferably higher than the refractive index of the first refractive index layer and lower than the refractive index of the second refractive index layer. Specifically, it is more preferably 1.50 or more and 1.65 or less, and even more preferably 1.55 or more and 1.60 or less.

[0051] Furthermore, when the optical laminate of the present disclosure is applied to a surface material for an outdoor display, etc., it is preferable that the functional layer located on the outermost surface is a hard coat layer. Examples of the layer configuration of an optical laminate having a hard coat layer as the first functional layer include the following: (1) A configuration having a hard coat layer and a substrate in this order. (2) A configuration having a first hard coat layer, a second hard coat layer, and a substrate in this order.

[0052] Each component contained in the functional layer will be described in detail below. The functional layer is a layer containing a binder resin as a main component. That is, the functional layer is a layer formed from a resin composition containing a binder resin as a main component. In the first embodiment, the first functional layer is a layer made of a resin containing a binder resin as a main component and a silicone-based material. That is, the first functional layer in the first embodiment is a layer formed from a resin composition containing a binder resin and a silicone-based material. In the second embodiment, the first functional layer is a layer made of a resin containing a binder resin as a main component and a silicone-based leveling agent. That is, the first functional layer in the second embodiment is a layer formed from a resin composition containing a binder resin and a silicone-based leveling agent.

[0053] The resin composition may further contain a solvent. The solvent is preferably selected depending on the types of binder resin and silicone-based material, and the type of substrate. Examples of the solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone (MIBK), and cyclohexanone; ethers such as dioxane and tetrahydrofuran; aliphatic hydrocarbons such as hexane; alicyclic hydrocarbons such as cyclohexane; aromatic hydrocarbons such as toluene and xylene; halogenated carbons such as dichloromethane and dichloroethane; esters such as methyl acetate, ethyl acetate, and butyl acetate; alcohols such as isopropanol, butanol, and cyclohexanol; cellosolves such as methyl cellosolve and ethyl cellosolve; glycol ethers such as propylene glycol monomethyl ether acetate; cellosolve acetates; sulfoxides such as dimethyl sulfoxide; amides such as dimethylformamide and dimethylacetamide; and mixtures thereof.

[0054] <Binder Resin> The binder resin is preferably a curable resin composition. Examples of the curable resin composition include a thermosetting resin composition and an ionizing radiation curable resin composition, and from the viewpoint of scratch resistance, an ionizing radiation curable resin composition is preferred. That is, it is optimal for the functional layer to contain a cured product of an ionizing radiation curable resin composition. The specific components of the binder resin can be appropriately selected depending on the performance required for the antireflection layer, the performance required for the hard coat layer, etc.

[0055] A thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that cures when heated. Examples of thermosetting resins include acrylic resins, urethane resins, phenolic resins, urea-melamine resins, epoxy resins, unsaturated polyester resins, and silicone resins. In a thermosetting resin composition, a curing agent is added to the curable resin as needed.

[0056] The ionizing radiation-curable resin composition is a composition containing a compound having an ionizing radiation-curable functional group (hereinafter also referred to as "ionizing radiation-curable compound"). Examples of the ionizing radiation-curable functional group include ethylenically unsaturated bond groups such as (meth)acryloyl groups, vinyl groups, and allyl groups, as well as epoxy groups and oxetanyl groups. The ionizing radiation-curable compound preferably has two or more ionizing radiation-curable functional groups. As the ionizing radiation-curable compound, a compound having an ethylenically unsaturated bond group is preferred. Among these, a (meth)acrylate-based compound having a (meth)acryloyl group is more preferred. Hereinafter, a (meth)acrylate-based compound having four or more ethylenically unsaturated bond groups will be referred to as a "polyfunctional (meth)acrylate-based compound." Furthermore, a (meth)acrylate-based compound having two to three ethylenically unsaturated bond groups will be referred to as a "low-functional (meth)acrylate-based compound."

[0057] As the (meth)acrylate compound, either a monomer or an oligomer can be used. Among the (meth)acrylate compounds, examples of bifunctional (meth)acrylate compounds include polyalkylene glycol di(meth)acrylates such as isocyanuric acid di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol diacrylate, and polybutylene glycol di(meth)acrylate, bisphenol A tetraethoxydiacrylate, bisphenol A tetrapropoxydiacrylate, and 1,6-hexanediol diacrylate. Examples of trifunctional (meth)acrylate compounds include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and isocyanuric acid-modified tri(meth)acrylate. Examples of polyfunctional (meth)acrylate compounds having tetrafunctionality or higher include pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol tetra(meth)acrylate, etc. These (meth)acrylate compounds may be modified as described below.

[0058] Examples of (meth)acrylate oligomers include acrylate polymers such as urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate. Urethane (meth)acrylates can be obtained, for example, by reacting a polyhydric alcohol and an organic diisocyanate with a hydroxy (meth)acrylate. Preferred epoxy (meth)acrylates include (meth)acrylates obtained by reacting a trifunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, or the like with (meth)acrylic acid; (meth)acrylates obtained by reacting a difunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, or the like with a polybasic acid and (meth)acrylic acid; and (meth)acrylates obtained by reacting a difunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, or the like with a phenol and (meth)acrylic acid.

[0059] In order to suppress uneven shrinkage due to crosslinking, the (meth)acrylate compound may have a part of its molecular skeleton modified, for example, with ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, cyclic alkyl, aromatic, bisphenol, or the like.

[0060] <Silicone-Based Leveling Agent> The silicone-based leveling agent orients on the surface of the resin composition after application, thereby imparting antifouling properties to the functional layer surface after the resin composition is cured, and also making the surface of the first functional layer smoother.

[0061] As described above, the silicone-based leveling agent used in the first embodiment includes a PDMS main chain type and an acrylic main chain type. Furthermore, the second embodiment requires the use of both a PDMS main chain type and an acrylic main chain type as the silicone-based leveling agent. The PDMS main chain type is preferably a type having a (meth)acryloyl group in the side chain. The acrylic main chain type is preferably a type having a silicone chain in the side chain. In both the first and second embodiments, the silicone-based leveling agent preferably does not contain fluorine atoms in its skeleton. By not including fluorine atoms in the silicone-based leveling agent, the ratio of fluorine elements to all elements on the first surface of the first functional layer is likely to be 0.5 at% or less.

[0062] The weight average molecular weight (Mw) of the PDMS main chain type is preferably 1,000 to 40,000, more preferably 5,000 to 35,000, and even more preferably 15,000 to 30,000. The weight average molecular weight (Mw) of the acrylic main chain type is preferably 1,000 to 30,000, more preferably 2,000 to 20,000, and even more preferably 3,000 to 10,000. The weight average molecular weight in this disclosure is the average molecular weight measured by GPC analysis and converted into standard polystyrene.

[0063] Examples of the PDMS main chain type include the product name "KP-420" (manufactured by Shin-Etsu Chemical Co., Ltd.) and the product name "TEGO (registered trademark) Rad2800" (manufactured by Evonik Japan Co., Ltd.). Examples of the acrylic main chain type include the product name "8SS-723" (manufactured by Taisei Fine Chemical Co., Ltd.) and the product name "8SS-2005" (manufactured by Taisei Fine Chemical Co., Ltd.). In the present disclosure, only one type of PDMS main chain type may be used, or multiple types may be used. Similarly, only one type of acrylic main chain type may be used, or multiple types may be used.

[0064] In both the first and second embodiments, the blending ratio of the silicone-based leveling agent (silicone-based material) is preferably 2.0 parts by mass or more relative to 100 parts by mass of the binder resin of the first functional layer. Furthermore, the blending ratio is preferably 18.0 parts by mass or less relative to 100 parts by mass of the binder resin of the first functional layer. By setting the blending ratio of the silicone-based leveling agent within the above range, good antifouling properties can be obtained. Furthermore, the average adsorption force F ａｖｅ and coefficient of variation of the adsorption force F ＣＶThis makes it easier to keep the content within the above-mentioned range. When a PDMS main chain type and an acrylic main chain type are used in combination, the above blending ratio represents the total of the PDMS main chain type and the acrylic main chain type. The blending ratio is more preferably 3.0 parts by mass or more, and even more preferably 4.0 parts by mass or more. Furthermore, the blending ratio is more preferably 15.0 parts by mass or less, and even more preferably 13.0 parts by mass or less. That is, the blending ratio of the silicone-based leveling agent (silicone-based material) is preferably 2.0 parts by mass or more and 18.0 parts by mass or less, more preferably 2.0 parts by mass or more and 15.0 parts by mass or less, more preferably 2.0 parts by mass or more and 13.0 parts by mass or less, more preferably 3.0 parts by mass or more and 18.0 parts by mass or less, more preferably 3.0 parts by mass or more and 15.0 parts by mass or less, more preferably 3.0 parts by mass or more and 13.0 parts by mass or less, more preferably 4.0 parts by mass or more and 18.0 parts by mass or less, more preferably 4.0 parts by mass or more and 15.0 parts by mass or less, and more preferably 4.0 parts by mass or more and 13.0 parts by mass or less.

[0065] When the first functional layer contains both a PDMS main chain type and an acrylic main chain type, the blending ratio of the PDMS main chain type to the acrylic main chain type (PDMS main chain type: acrylic main chain type, mass ratio) is preferably 0.5:4.5 to 4.9:0.1, more preferably 1.0:4.0 to 4.0:1.0, and even more preferably 2.0:3.0 to 2.5:2.5. By setting the blending ratio within the above range, good antifouling properties can be obtained. In addition, the average adsorption force F ａｖｅ and coefficient of variation of the adsorption force F ＣＶ Furthermore, the average value F' of the adsorption force after rubbing can be easily set in the above-mentioned range. ａｖｅ , coefficient of variation F' of adsorption force after rubbing ＣＶ , and the rate of change ΔF of the average value of the adsorptive force can be easily set within the above-mentioned range. Note that the notation AA:BB to CC:DD above indicates a range that includes AA:BB and CC:DD.

[0066] In both the first and second embodiments, the resin composition for forming the first functional layer preferably does not contain a fluorine-based leveling agent, which makes it easier to keep the ratio of fluorine elements to all elements on the first surface of the first functional layer at 0.5 at% or less.

[0067] <Other Components> The functional layer may contain the following components. When the ionizing radiation-curable resin is an ultraviolet-curable resin, the resin composition preferably contains additives such as a photopolymerization initiator and a photopolymerization accelerator. Examples of the photopolymerization initiator include one or more selected from acetophenone, benzophenone, α-hydroxyalkylphenone, Michler's ketone, benzoin, benzyl dimethyl ketal, benzoyl benzoate, α-acyloxime ester, α-aminoalkylphenone, thioxanthones, and the like. The photopolymerization accelerator can reduce polymerization inhibition by air during curing and increase the curing rate, and examples thereof include one or more selected from p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester, and the like.

[0068] When the first functional layer is the above-described first refractive index layer, the resin composition preferably contains hollow silica particles and solid silica particles, i.e., the first refractive index layer contains hollow silica particles and solid silica particles.

[0069] Hollow silica particles refer to particles that have an outer shell layer made of silica, and the interior of the particle surrounded by the outer shell layer is hollow, and the hollow contains air. Hollow silica particles are particles whose refractive index decreases in proportion to the gas occupancy rate compared to the inherent refractive index of silica due to the inclusion of air. Non-hollow silica particles are particles that do not have a hollow interior like hollow silica particles. Non-hollow silica particles are, for example, solid silica particles. The shape of hollow silica particles and non-hollow silica particles is not particularly limited, and may be spherical, spheroidal, or approximately spherical, such as a polyhedral shape that can approximate a sphere. Among these, spherical, spheroidal, or approximately spherical shapes are preferred in terms of scratch resistance.

[0070] Hollow silica particles contain air inside, which serves to lower the refractive index of the entire functional layer. By using hollow silica particles with a large particle size and a high air ratio, the refractive index of the functional layer can be further lowered. On the other hand, hollow silica particles tend to have poor mechanical strength. In particular, when hollow silica particles with a large particle size and a high air ratio are used, the scratch resistance of the functional layer tends to be easily reduced. By being dispersed in a binder resin, non-hollow silica particles serve to improve the scratch resistance of the functional layer.

[0071] Considering optical properties and mechanical strength, the average particle size of hollow silica particles is preferably 50 nm or more and 100 nm or less, more preferably 60 nm or more and 80 nm or less.Furthermore, considering dispersibility while preventing aggregation of non-hollow silica particles, the average particle size of non-hollow silica particles is preferably 5 nm or more and 20 nm or less, more preferably 10 nm or more and 15 nm or less.Furthermore, the ratio of the average particle size of non-hollow silica particles to the average particle size of hollow silica particles is preferably 0.29 or less, more preferably 0.20 or less.The ratio of average particle sizes is preferably 0.05 or more.

[0072] The "average particle size" in the present invention is calculated by the following steps (1) to (3). (1) A cross section of an optical laminate having a functional layer containing particles is imaged using a TEM or STEM. The acceleration voltage of the TEM or STEM is 10 kV to 30 kV, and the magnification is within the range of 50,000 to 300,000 times. (2) Ten particles are randomly selected from the observed image, and the particle size of each particle is calculated. The particle size is measured as the distance between two parallel lines that maximize the distance between the cross section of the particle. (3) The same procedure is performed five times using a separate image of the same sample, and the value obtained from the number average of a total of 50 particles is regarded as the average particle size of the particles.

[0073] The surfaces of the hollow silica particles and non-hollow silica particles are preferably coated with a silane coupling agent. It is more preferable to use a silane coupling agent having a (meth)acryloyl group or an epoxy group. By subjecting the silica particles to surface treatment with a silane coupling agent, the affinity between the silica particles and the binder resin is improved, making the silica particles less likely to aggregate. Therefore, the silica particles are more likely to be dispersed uniformly. The amount of the silane coupling agent used in the surface treatment is sufficiently smaller than the amount of the silicone-based material contained in the first refractive index layer (first functional layer). Specifically, the amount of the silane coupling agent contained in the first refractive index layer (first functional layer) is estimated to be about 0.01 parts by mass per 100 parts by mass of the binder resin of the first refractive index layer (first functional layer). Therefore, the silane coupling agent used in the surface treatment is preferably selected from the group consisting of a silicon atom belonging to silicone and a silicon atom belonging to all elements on the first surface of the first functional layer, as described above. Ｓｉ does not affect the

[0074] Examples of silane coupling agents include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-triethoxysilyl-N-(1,3-di methyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, trifluoropropyltrimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane. In particular, it is preferable to use one or more selected from 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane.

[0075] The higher the content of hollow silica particles, the higher the filling rate of hollow silica particles relative to the binder resin, and the lower the refractive index of the first refractive index layer. On the other hand, if the content of hollow silica particles relative to the binder resin is too high, there will be less binder resin bonding between the particles, and the hollow silica particles will tend to be damaged or easily fall off. For this reason, the content of hollow silica particles is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, relative to 100 parts by mass of binder resin. Furthermore, the content of hollow silica particles is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, relative to 100 parts by mass of binder resin.

[0076] If the content of non-hollow silica particles is low, the presence of non-hollow silica particles on the surface of the low refractive index layer may not affect the increase in mechanical strength.If the content of non-hollow silica particles is too high, the non-hollow silica particles will aggregate, causing uneven shrinkage of the binder resin and increasing surface irregularities.The content of non-hollow silica particles is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, relative to 100 parts by mass of the binder resin.The content of non-hollow silica particles is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, relative to 100 parts by mass of the binder resin.

[0077] Furthermore, when a second refractive index layer is provided, the second refractive index layer preferably contains high-refractive index particles. In this case, the second refractive index layer contains high-refractive index particles. Examples of high-refractive index particles include antimony pentoxide, zinc oxide, titanium oxide, cerium oxide, tin-doped indium oxide, antimony-doped tin oxide, yttrium oxide, and zirconium oxide. The average particle size of the high-refractive index particles is preferably 5 nm or more and 200 nm or less, more preferably 5 nm or more and 100 nm or less, and even more preferably 10 nm or more and 80 nm or less.

[0078] From the viewpoint of achieving a balance between a high refractive index and coating film strength, the content of the high refractive index particles is preferably 30 parts by mass or more and 2,500 parts by mass or less, more preferably 300 parts by mass or more and 2,200 parts by mass or less, and even more preferably 500 parts by mass or more and 2,000 parts by mass or less, relative to 100 parts by mass of the binder resin.

[0079] Furthermore, additives such as ultraviolet absorbers, antistatic agents, antioxidants, surfactants, and dispersants may be added to the resin composition.

[0080] <Primer Layer> The primer layer is a layer provided between the substrate and the functional layer. The primer layer has the effect of increasing the adhesion between the substrate and the functional layer. The primer layer is a layer containing a binder resin. That is, the functional layer is a layer formed from a resin composition containing a binder resin as a main component. The binder resin is preferably a curable resin composition. Examples of the curable resin composition include a thermosetting resin composition and an ionizing radiation curable resin composition. Of these, an ionizing radiation curable resin composition is preferred.

[0081] The binder resin is not particularly limited, and preferred examples include urethane resin, acrylic polyol resin, acrylic resin, polyester resin, alkyd resin, amide resin, butyral resin, styrene resin, urethane-acrylic copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-acrylic copolymer, nitrocellulose (nitrocellulose), cellulose acetate, and other resins. Furthermore, curable resins such as two-component curing urethane resins containing polyol as a main component and isocyanate as a curing agent may also be used. These may be used alone or in combination.

[0082] The primer layer may contain inorganic particles such as silica or zirconia particles to adjust the refractive index.

[0083] The resin composition for forming the primer layer may further contain a solvent. The solvent used in the resin composition for forming the primer layer can be selected from the solvents exemplified as the resin composition for forming the functional layer.

[0084] [Polarizing Plate] The polarizing plate of the present disclosure is a polarizing plate having a polarizer, a first transparent protective plate arranged on one side of the polarizer, and a second transparent protective plate arranged on the other side of the polarizer, wherein one of the first transparent protective plate and the second transparent protective plate is the optical laminate of the first embodiment or the second embodiment described above, and the surface on the first surface side of the optical laminate is arranged so as to face away from the polarizer.

[0085] The polarizing plate is used to impart anti-reflection properties, for example, in combination with a λ / 4 retardation plate. In this case, the λ / 4 retardation plate is disposed on the display element of the image display device, and the polarizing plate is disposed closer to the viewer than the λ / 4 retardation plate.

[0086] In liquid crystal display devices, polarizing plates are used to impart the function of a liquid crystal shutter. In this case, the liquid crystal display device is arranged in the order of a lower polarizing plate, a liquid crystal display element, and an upper polarizing plate from the backlight side, with the absorption axis of the polarizer of the lower polarizing plate and the absorption axis of the polarizer of the upper polarizing plate being orthogonal to each other. In the configuration of a liquid crystal display device, polarizing plates of the present disclosure can be used as the upper polarizing plate and the lower polarizing plate, and it is preferable to use a polarizing plate of the present disclosure as the upper polarizing plate. In the upper polarizing plate, it is preferable to use an optical laminate of the present disclosure as a transparent protective plate on the light exit surface side of the polarizer. In the lower polarizing plate, it is preferable to use an optical laminate of the present disclosure as a transparent protective plate on the light incident surface side of the polarizer.

[0087] <Transparent Protective Plate> The polarizing plate of the present disclosure includes the optical laminate of the present disclosure as one of the first transparent protective plate and the second transparent protective plate. When one of the first transparent protective plate and the second transparent protective plate includes the optical laminate of the first embodiment or the second embodiment, the other transparent protective plate is preferably an optically isotropic transparent protective plate. In this specification, optically isotropic refers to an in-plane retardation of 20 nm or less, preferably 10 nm or less, and more preferably 5 nm or less. Acrylic films and triacetyl cellulose (TAC) films are easily imparted with optical isotropy.

[0088] When one of the first transparent protective plate and the second transparent protective plate includes the optical laminate of the present disclosure described above, it is preferable that the transparent protective plate on the light emission side includes the optical laminate of the present disclosure described above.

[0089] <Polarizer> Examples of polarizers include sheet-type polarizers such as polyvinyl alcohol films, polyvinyl formal films, polyvinyl acetal films, and saponified ethylene-vinyl acetate copolymer films that are dyed with iodine or the like and stretched; wire-grid polarizers made of a large number of metal wires arranged in parallel; coating-type polarizers coated with a lyotropic liquid crystal or a dichroic guest-host material; and multilayer thin-film polarizers. These polarizers may be reflective polarizers that have the function of reflecting polarized components that are not transmitted.

[0090] [Image Display Panel] The image display panel of the present disclosure is an image display panel having a display element and an optical film arranged on the light emission surface side of the display element, and includes the optical laminate of the first embodiment or the second embodiment described above as the optical film, and is arranged so that the surface on the first surface side of the optical laminate faces away from the display element.

[0091] Examples of the display element include a liquid crystal display element, an EL display element such as an organic EL display element or an inorganic EL display element, a plasma display element, etc., and further includes an LED display element such as a micro LED display element. These display elements may have a touch panel function inside the display element.

[0092] Examples of the liquid crystal display system of the liquid crystal display element include the IPS system, VA system, multi-domain system, OCB system, STN system, and TSTN system. The image display panel of the present disclosure may be an image display panel with a touch panel. In this case, the optical laminate may be used as a component constituting the touch panel. The size of the image display panel is not particularly limited, but the maximum diameter is approximately 2 inches or more and 500 inches or less. The maximum diameter means the maximum length when connecting any two points on the surface of the image display panel.

[0093] [Image Display Device] The image display device of the present disclosure includes the image display panel of the present disclosure. Preferably, the image display device of the present disclosure further includes a drive control unit electrically connected to the image display panel, and a housing that houses the image display panel, the drive control unit, etc.

[0094] When the display element is a liquid crystal display element, the image display device of the present disclosure requires a backlight. The backlight is disposed on the side opposite to the light-emitting surface side of the liquid crystal display element. The size of the image display device is not particularly limited, but the maximum diameter of the effective display area is approximately 2 inches to 500 inches.

[0095] The effective display area of ​​an image display device is the area in which an image can be displayed. For example, if the image display device has a housing that surrounds the display element, the area inside the housing is the effective display area. The maximum diameter of the effective display area refers to the maximum length when any two points within the effective display area are connected. For example, if the effective display area is rectangular, the diagonal of the rectangle is the maximum diameter. If the effective display area is circular, the diameter of the circle is the maximum diameter.

[0096] Next, the present disclosure will be described in more detail using examples, but the present disclosure is not limited to these examples. 1. Measurement and Evaluation Measurement and evaluation of the optical laminate of each test example were performed as follows. The atmosphere during each measurement and evaluation was a temperature of 23±5°C and a relative humidity of 40% to 65%. Before starting each measurement and evaluation, the target sample was exposed to the atmosphere for 30 minutes to 60 minutes, and then measurement and evaluation were performed. The sample used for each measurement and evaluation can be prepared by cutting the optical laminate of each test example. The cutting location was selected from random locations after visually confirming that there were no abnormalities such as dust or scratches.

[0097] 1-1. Adhesion Force Measurement (1) Adhesion Force A scanning probe microscope (Shimadzu Corporation, SPM-9600) was used to measure the adhesion force. The cantilever to be used (described below) was immersed in 30 cc of acetone for 30 seconds. After immersion, the cantilever was dried and then attached to the atomic force microscope. Before measuring the sample, the sensitivity of the cantilever was measured. For the sensitivity measurement, a glass plate (ASONE: Azlabo slide glass (soda), model number: 1-9646-11, 5 mm x 5 mm square, washed with acetone before measurement) was used. The glass plate was placed on the stage and left in this state for 10 minutes. After leaving it to stand, measurements were performed using the On-Line (measurement) mode of the SPM Manager software under the measurement conditions described below, and a force curve was obtained. Then, in the Off-Line (analysis mode) of the software, the slope of the line in the region where the cantilever is subjected to a repulsive force and warps upward was calculated in the force curve corresponding to the process of the cantilever coming into contact with the sample and being pressed against it. Force curves were measured and the slopes were calculated for five arbitrary points on the surface of the sample.

[0098] After the sensitivity measurement, the sample was placed on the stage with the low refractive index layer (functional layer) facing the cantilever. It was left to stand in this state for 10 minutes. After standing, the adhesive force of the surface of the low refractive index layer (functional layer) at each measurement point was measured under the following measurement conditions in the On-Line (measurement) mode of the software: SPM Manager. The average value, standard deviation, and coefficient of variation were calculated from the obtained adhesive force, and the average adhesive force F ａｖｅ and coefficient of variation of the adsorption force F ＣＶ <Measurement conditions> Cantilever: CONTR manufactured by Nanoworld AG (single crystal Si (resistivity 0.01 cm to 0.025 Ω cm), probe shape: Pointprobe (registered trademark), probe length: 10 μm to 15 μm, radius of curvature: 8 nm, cantilever length: 450 μm, spring constant 0.2 N / m, resonance frequency 13 kHz) Cantilever sensitivity: Value obtained by the above method Measurement mode: Force curve Measurement area: 10 μm × 10 μm Number of pixels: 32 × 32 Measurement locations: Each pixel (1024 locations) Scanning speed: 2 Hz

[0099] (2) Adsorption force after rubbing Next, the substrate side of the sample of each test example after measuring the adsorption force according to the procedure described above was attached to the base of a Gakushin abrasion tester (manufactured by Tester Sangyo Co., Ltd., product name "AB-301"). An abrasive was attached to the friction element of the tester, and the surface of the low refractive index layer (functional layer) was rubbed under the following rubbing conditions. [Rubbing conditions] Abrasive: Acetone-soaked cloth Load: 150 g / cm ２ Number of times of sliding: 5 times (one way) Then, by the same method as in (1) above, the adhesive force of the surface of the low refractive index layer (functional layer) of each test example sample was measured at the measurement points (1024 points) of each sample. From the obtained adhesive forces, the average value, standard deviation, and coefficient of variation were calculated, and the average adhesive force F' after rubbing was calculated. ａｖｅ , coefficient of variation F' of adsorption force after rubbing ＣＶ The rate of change ΔF of the average value of the adsorptive force was calculated using the following formula (1): ΔF (%) = (F ａｖｅ -F' ａｖｅ ) / F ａｖｅ ×100 (1)

[0100] 1-2. XPS Analysis Using an X-ray photoelectron spectrometer, the X-ray photoelectron spectrum of the surface of the low refractive index layer of each test example sample was measured under the conditions described below. For each detected element, peak separation of the spectrum of a predetermined orbital was performed. The ratio of F element to all elements (C Ｆ ), and the ratio of Si element belonging to silicone (organosilicon compound) (C Ｓｉ ) was determined. Measurements were made at 14 locations for each sample, and further analysis was performed on two samples (n = 2). The average of these was used as the element ratio for each test example. <Measurement> Apparatus: AXIS-NOVA manufactured by Kratos X-ray source: AlKα X-ray output: 150 W Emission current: 10 mA Acceleration voltage: 15 kV Measurement area: 300 × 700 μm

[0101] Next, samples of other test examples were prepared, and the surface of the low refractive index layer was rubbed with a rubber by the method described in 1-1. XPS analysis was performed on the samples of each test example after rubbing by the same method as above, and the ratio of Si element attributable to silicone to all elements after rubbing (C' Ｓｉ) was calculated. Then, the rate of change in the ratio of silicon atoms, ΔC Ｓｉ was calculated. Ｓｉ (%) = (C Ｓｉ -C' Ｓｉ ) / C Ｓｉ ×100 (2)

[0102] 1-3. Fingerprint Wiping Ease A fingerprint was left with the index finger on the surface of the low refractive index layer side of each test example sample. The area to be left with the fingerprint was 1 cm long x 1 cm wide. A wiping tool was prepared by fixing a clean room wiper (product name "Proplea LW" by AS ONE Corporation) to the entire surface of a 1 kg weight. The size of the jig was a rectangle with a diagonal of 6 inches. The jig was placed on the fingerprinted area so that the surface with the wiper attached was in contact with the fingerprinted area. The jig was manually moved back and forth over the area, and the number of times it was moved back and forth until the fingerprint was wiped off was counted. Whether the fingerprint was wiped off was visually evaluated by a healthy person in their 30s. Fingerprint wiping ease was evaluated according to the number of times it was wiped off, based on the following criteria. Grades A to C were judged to be "pass". A: The fingerprint was wiped off in 2 or fewer strokes. B: The fingerprint was wiped off in 3 to 5 strokes. C: Fingerprints were wiped off after 6 to 10 strokes. D: Fingerprints were wiped off after 11 to 20 strokes. E: Fingerprints could not be wiped off even after 20 strokes.

[0103] 1-4. Ink Wiping Property Ink from a black oil-based marking pen (YYTS5-BK, manufactured by Zebra Corporation) was applied to the surface of the low refractive index layer side of the sample of each test example. The application area was an area of ​​1 cm length x 1 cm width. A 1 kg weight and a 500 g weight were prepared. A clean room wiper (Proplea LW, product name, manufactured by AS ONE Corporation) was fixed to the entire surface of the weight to prepare a wiping jig. The size of the jig was a rectangle with a diagonal length of 6 inches. After impregnating the wiper with ethanol, the jig was placed on the area where the marking pen ink had been applied so that the surface where the wiper was attached was in contact with the area. The jig was manually moved back and forth over the area without applying a manual load, and the number of times it was moved back and forth until the ink was wiped off was counted. If the ink could not be wiped off after five strokes, the jig was pressed firmly against the area (while applying a manual load) and manually moved back and forth to count the number of strokes until the marker was wiped off. The above measurements were performed using a 1 kg weight and a 500 g weight. Whether the ink was wiped off was visually evaluated by a healthy person in their 30s. Depending on the number of strokes and the method of applying the load, the ink wiping ability was evaluated when a 1 kg and 500 g load was applied according to the following criteria. Evaluations A to C were judged to be "pass". A: The ink was wiped off in one stroke. B: The ink was wiped off in two or three strokes. C: The ink was wiped off in four or five strokes. D: The ink was not wiped off even after five strokes, but it was wiped off when the jig was pressed back and forth while being pressed firmly. E: The ink could not be wiped off even after five reciprocating movements, and the ink could not be wiped off even when the jig was pressed firmly against the surface and moved back and forth.

[0104] 2. Preparation of Optical Laminate [Test Example 1] A coating solution for a hard coat layer having the following formulation was applied to a triacetyl cellulose (TAC) film having a thickness of 60 μm, and then dried at 70° C. for 1 minute to volatilize the solvent. Subsequently, the film was irradiated with an integrated light intensity of 100 mJ / cm in a nitrogen atmosphere having an oxygen concentration of 200 ppm or less. ２A hard coat layer having a dry thickness of 10.0 μm was formed by irradiating the hard coat layer with ultraviolet light at a rate of 100 mJ / cm in a nitrogen atmosphere having an oxygen concentration of 200 ppm or less. ２ A high refractive index layer having a dry thickness of 140 nm was formed by irradiating the high refractive index layer with ultraviolet light at a rate of 100 mJ / cm2. Next, a coating solution for a low refractive index layer having the following formulation was applied onto the high refractive index layer, and then dried at 40°C for 60 seconds (drying air speed: 20 m / s) to volatilize the solvent. Subsequently, the coating solution was irradiated with ultraviolet light at a rate of 100 mJ / cm2 in a nitrogen atmosphere having an oxygen concentration of 200 ppm or less. ２ A low refractive index layer (functional layer) having a dry thickness of 100 nm was formed by irradiating the coated layer with ultraviolet light at 1000 .mu.m., thereby obtaining an optical laminate of Test Example 1.

[0105] <Coating liquid for hard coat layer> - UV-curable acrylate-containing composition 1 (manufactured by Toagosei Co., Ltd., trade name "Aronix M-450", solid content 100%) 22 parts by mass - UV-curable acrylate-containing composition 2 (manufactured by Daiichi Kogyo Co., Ltd., trade name "New Frontier R-1403MB", solid content 80%) 17 parts by mass - Silicone-based leveling agent (manufactured by Kyoeisha Chemical Co., Ltd., trade name "LE-304") 1 part by mass - Photopolymerization initiator (manufactured by IGM Resins, trade name "Omnirad 184") 1 part by mass - Methyl isobutyl ketone 15 parts by mass - Methyl ethyl ketone 44 parts by mass <Coating liquid for forming high refractive index layer> - UV-curable resin (manufactured by Arakawa Chemical Co., Ltd., trade name "Beamset 577") 1.25 parts by mass Zirconium oxide (manufactured by Sumitomo Osaka Cement Co., Ltd., trade name "MZ-230X", solid content 32.5% by mass, average particle size 15 to 50 nm) 6 parts by mass Leveling agent (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., trade name "Seikabeam 10-28 (MB)") 0.05 parts by mass Polymerization initiator (manufactured by BASF, Irgacure 127) 0.1 parts by mass Solvent (methyl isobutyl ketone / cyclohexanone / methyl ethyl ketone = 4 / 2 / 4) 92.6 parts by mass The coating liquid for forming a high refractive index layer was prepared by the following procedure. First, a polymerization initiator was added to a dilution solvent and stirred until no residue remained. To the stirred solution, an ultraviolet-curable resin was added and further stirred until no residue remained. Thereafter, zirconium oxide and a leveling agent were added to the solution and stirred, thereby obtaining a coating liquid for forming a high refractive index layer.

[0106] <Coating liquid for low refractive index layer> (1) Binder resin - UV-curable resin (manufactured by Arakawa Chemical Industries, Ltd., trade name "Beamset 577") 100 parts by mass (2) Silicone-based leveling agent - Silicone-based leveling agent 1 (SL1): manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KP-420" (PDMS main chain type) 1.0 part by mass (1.0% by mass based on binder resin) - Silicone-based leveling agent 2 (SL2): manufactured by Taisei Fine Chemical Co., Ltd., trade name "8SS-2005" (acrylic main chain type) 4.0 parts by mass (4.0% by mass based on binder resin) - Blending ratio SL1:SL2 = 20:80 (mass ratio) (3) Hollow silica particles 60 parts by mass of hollow silica particles having an average particle diameter of 100 nm and surface-treated with a silane coupling agent having a methacryloyl group (4) Solid silica particles (5) Photopolymerization initiator: IGM Resins, trade name "Omnirad 127" 25 parts by mass (6) Solvent: Methyl ethyl ketone 20 parts by mass; Methyl isobutyl ketone 50 parts by mass; Propylene glycol monomethyl ether acetate 30 parts by mass

[0107] [Test Example 2] An optical laminate of Test Example 2 was obtained in the same process as Test Example 1, except that the blending amounts of the silicone leveling agents were changed as follows: Silicone leveling agent 1 (SL1) 2.0 parts by mass (2.0% by mass relative to the binder resin) Silicone leveling agent 2 (SL2) 3.0 parts by mass (3.0% by mass relative to the binder resin) Blending ratio SL1:SL2 = 40:60 (mass ratio)

[0108] [Test Example 3] An optical laminate of Test Example 3 was obtained in the same process as Test Example 1, except that the blending amounts of the silicone leveling agents were changed as follows: Silicone leveling agent 1 (SL1) 2.5 parts by mass (2.5% by mass relative to the binder resin) Silicone leveling agent 2 (SL2) 2.5 parts by mass (2.5% by mass relative to the binder resin) Blending ratio SL1 / SL2 = 50 / 50 (mass ratio)

[0109] Test Example 4 An optical laminate of Test Example 4 was obtained in the same manner as Test Example 1, except that the blending amounts of the silicone leveling agents were changed as follows: Silicone leveling agent 1 (SL1) 3.0 parts by mass (3.0% by mass relative to the binder resin) Silicone leveling agent 2 (SL2) 2.0 parts by mass (2.0% by mass relative to the binder resin) Blending ratio SL1:SL2 = 60:40 (mass ratio)

[0110] [Test Example 5] An optical laminate of Test Example 5 was obtained in the same process as Test Example 1, except that the blending amounts of the silicone leveling agents were changed as follows: Silicone leveling agent 1 (SL1) 4.0 parts by mass (4.0% by mass relative to the binder resin) Silicone leveling agent 2 (SL2) 1.0 part by mass (1.0% by mass relative to the binder resin) Blending ratio SL1:SL2 = 80:20 (mass ratio)

[0111] Test Example 6 An optical laminate of Test Example 6 was obtained in the same steps as Test Example 1, except that the following silicone-based leveling agents were used: Silicone-based leveling agent 1 (SL1) 2.5 parts by mass (2.5% by mass relative to the binder resin) Silicone-based leveling agent 3 (SL3): 2.5 parts by mass (2.5% by mass relative to the binder resin) trade name "8SS-723" (acrylic main chain type), manufactured by Taisei Fine Chemical Co., Ltd. Blending ratio SL1:SL3 = 50:50 (mass ratio)

[0112] Test Example 7 An optical laminate of Test Example 7 was obtained in the same steps as Test Example 1, except that the following silicone-based leveling agents were used: Silicone-based leveling agent 1 (SL1): 10 parts by mass (10.0% by mass based on the binder resin) of trade name "KP-420" (PDMS main chain type) manufactured by Shin-Etsu Chemical Co., Ltd. Silicone-based leveling agent 2 (SL2): 2.5 parts by mass (2.5% by mass based on the binder resin) of trade name "8SS-2005" (acrylic main chain type) manufactured by Taisei Fine Chemical Co., Ltd. Blending ratio SL1:SL2 = 20:80 (mass ratio)

[0113] Test Example 8 An optical laminate of Test Example 8 was obtained in the same steps as Test Example 1, except that the following silicone-based leveling agents were used: Silicone-based leveling agent 4 (SL4): 2.5 parts by mass (2.5% by mass based on the binder resin) of trade name "TEGO (registered trademark) Rad2800" (PDMS main chain type) manufactured by Evonik Japan Co., Ltd. Silicone-based leveling agent 2 (SL2): 2.5 parts by mass (2.5% by mass based on the binder resin) of trade name "8SS-2005" (acrylic main chain type) manufactured by Taisei Fine Chemical Co., Ltd. Blending ratio SL4:SL2 = 50:50 (mass ratio)

[0114] Test Example 9 An optical layered body of Test Example 9 was obtained in the same manner as in Test Example 1, except that the following silicone-based leveling agent was used: Silicone-based leveling agent 2 (SL2) 5.0 parts by mass (5.0% by mass based on the binder resin)

[0115] Test Example 10 An optical laminate of Test Example 10 was obtained in the same manner as in Test Example 1, except that the following silicone-based leveling agent was used: Silicone-based leveling agent 3 (SL3) 2.5 parts by mass (2.5% by mass relative to the binder resin)

[0116] Test Example 11 An optical layered body of Test Example 11 was obtained in the same manner as in Test Example 1, except that the following silicone-based leveling agent was used: Silicone-based leveling agent 4 (SL4) 5.0 parts by mass (5.0% by mass relative to the binder resin)

[0117] Reference Example 1 An optical layered body of Reference Example 1 was obtained in the same manner as in Test Example 1, except that the silicone-based leveling agent was not used, and the following fluorine-based leveling agent was used: Fluorine-based leveling agent: 5.0 parts by mass of trade name "Megafac RS-58" manufactured by DIC Corporation

[0118] 3. Results The evaluation results of each test example and reference example are shown in Table 1. In Table 1, the average adsorption force F ａｖｅ , coefficient of variation of the adsorption force F ＣＶ , F element ratio C Ｆ , and the ratio C of Si element belonging to silicone Ｓｉ The above was described as "before rubbing."

[0119]

[0120] In all of Test Examples 1 to 11, a silicone-based leveling agent was used as the silicone-based material in the coating liquid for the low refractive index layer, and a resin that does not contain fluorine atoms was used as the binder resin, so no fluorine atoms were detected on the surface of the low refractive index layer (functional layer). ａｖｅ is 2.0 nN or more, and the coefficient of variation of the adsorptive force F ＣＶ The fingerprint wiping property and ink wiping property in Test Examples 1 to 9 were both equivalent to those in Reference Example 1, or were slightly inferior in evaluation but were still wiping-able. Thus, it can be said that Test Examples 1 to 9 achieved antifouling properties sufficient for practical use.

[0121] Comparing Test Examples 1 to 5, in which the compounding ratio of the PDMS main chain type to the acrylic main chain type was changed as the silicone-based leveling agent, it was found that the fingerprint wiping property and ink wiping property tended to improve as the compounding ratio approached 50:50 (mass ratio). As described above, the higher the proportion of the PDMS-based main chain type, the more a layer in which the PDMS main chain type is mainly present near the surface of the low refractive index layer is formed, and therefore the average value F ａｖｅ On the other hand, as the proportion of the acrylic main chain type increases, the PDMS main chain type and the acrylic main chain type become almost uniformly distributed on the surface, and the coefficient of variation F ＣＶ It is believed that as the blending ratio approaches 50:50 (mass ratio), the balance between the effects of the PDMS-based main chain and the effects of the acrylic main chain becomes better, resulting in better fingerprint wiping properties and ink wiping properties.

[0122] In contrast, in Test Example 10, the average value of the adsorption force F ａｖｅ is low, and the coefficient of variation of the adsorption force F ＣＶ Therefore, it is considered that sufficient fingerprint wiping ability and ink wiping ability were not obtained. ａｖｅ Although the coefficient of variation of the adsorption force F ＣＶ It is believed that this is the reason why sufficient fingerprint and ink wiping properties were not obtained.

[0123] Furthermore, in Test Examples 1 to 9, the average value F' of the adsorption force after rubbing ａｖｅ The change rate ΔF in the Si element attributed to silicone in the XPS analysis was higher in Test Examples 1 to 9 than in Test Examples 10 and 11. Ｓｉ This result indicates that the silicone leveling agent is not easily removed by rubbing (an action equivalent to wiping). In other words, since the silicone leveling agent remains on the surface of the low refractive index layer (functional layer) even after wiping, it can be said that sufficient antifouling properties can be maintained.

[0124] Furthermore, Test Examples 1 to 8 are examples in which the low refractive index layer (functional layer) contains two types of silicone-based leveling agents, one predominantly PDMS type and one predominantly acrylic type. In Test Examples 1 to 8, at least one of the fingerprint wiping properties and the ink wiping properties was rated B or higher. On the other hand, Test Example 9 is an example in which the low refractive index layer (functional layer) contains only an acrylic-based silicone-based leveling agent, but both the fingerprint wiping properties and the ink wiping properties were rated C. Furthermore, Test Examples 10 and 11, in which the low refractive index layer (functional layer) contains only a PDMS-based or only an acrylic-based low refractive index layer, had poor evaluation results for the fingerprint wiping properties and the ink wiping properties. Thus, it can be said that by including two types of silicone-based leveling agents, one predominantly PDMS type and one predominantly acrylic type, in the low refractive index layer (functional layer), good fingerprint wiping properties and ink wiping properties can be obtained.

[0125] 10, 20, 30 Optical laminate 11, 21, 31 Substrate 12, 22, 32 Functional layer 33 Primer layer

Claims

1. An optical laminate having at least one functional layer on a substrate, wherein the optical laminate has a first surface that is a surface on the functional layer side and a second surface that is a surface on the substrate side, the functional layer includes a first functional layer, and the first surface is a surface of the first functional layer opposite to the substrate, the first functional layer includes a silicone-based material, and the ratio of fluorine element to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is 0.5 at% or less, and the average adsorption force F of the first surface measured using an atomic force microscope under the following measurement conditions: ａｖｅ is 2.0 nN or more, and the coefficient of variation of the adsorptive force F ＣＶ An optical laminate having a refractive index of 0.50 or less. [Measurement conditions] Probe: single crystal Si, probe length 10 μm to 15 μm, radius of curvature 8 nm, spring constant 0.2 N / m Measurement mode: force curve Measurement area: 10 μm × 10 μm Number of pixels: 32 × 32 Measurement points: each pixel (1024 points) Scanning speed: 2 Hz 2. Average value of the adsorption force F ａｖｅ The optical laminate of claim 1, wherein the surface roughness is 20.0 nN or less.

3. Coefficient of variation of the adsorption force F ＣＶ The optical laminate according to claim 1, wherein the refractive index is 0.30 or less.

4. The ratio C of silicon element attributable to silicon to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy Ｓｉ The optical laminate according to claim 1, wherein the content of the SiO 2 is 2.5 at % or more and 15.0 at % or less.

5. After rubbing the first surface of the first functional layer under the following rubbing conditions, the average value F' of the post-rubbing adsorption force is measured for the first surface under the above measurement conditions. ａｖｅ is 2.0 nN or more, and the coefficient of variation F' of the adsorptive force after rubbing is ＣＶ 3. The optical laminate according to claim 1, wherein the surface roughness is 4.0 or less. [Rubbing conditions] Scraping material: a cloth soaked in acetone Load: 150 g / cm ２ Number of strokes: 5 (one way) 6. The optical laminate according to claim 5, wherein the rate of change ΔF of the average adsorption force, expressed by the following formula (1), is 25.0% or less. ΔF (%) = (F ａｖｅ -F' ａｖｅ ) / F ａｖｅ ×100 (1) 7. The ratio of silicon element attributable to silicone to all elements obtained by analyzing the first surface of the first functional layer before rubbing by X-ray photoelectron spectroscopy is C Ｓｉ and C' is the ratio of silicon element attributable to silicone to all elements obtained by analyzing the first surface of the first functional layer after rubbing by X-ray photoelectron spectroscopy. Ｓｉ When expressed as: the rate of change ΔC of the silicon atom ratio represented by the following formula (2) Ｓｉ The optical laminate according to claim 5, wherein ΔC is 25.0% or less. Ｓｉ (%) = (C Ｓｉ -C' Ｓｉ ) / C Ｓｉ ×100 (2) 8. The optical laminate according to claim 1, wherein the silicone-based material is a silicone-based leveling agent.

9. The optical laminate according to claim 1, wherein the first functional layer is a first refractive index layer, and the first refractive index layer contains hollow silica particles and solid silica particles.

10. The optical laminate according to claim 9, wherein the functional layer includes a second functional layer between the first functional layer and the substrate, and the second functional layer is a second refractive index layer having a higher refractive index than the first refractive index layer, which is the first functional layer.

11. An optical laminate having at least one functional layer on a substrate, wherein the optical laminate has a first surface that is the surface on the functional layer side and a second surface that is the surface on the substrate side, the functional layer includes a first functional layer, and the first surface is the surface of the first functional layer opposite the substrate, the first functional layer includes a silicone-based leveling agent having dimethylpolysiloxane in its main chain and a silicone-based leveling agent having acrylic in its main chain, and the ratio of fluorine element to all elements obtained by analyzing the first surface by X-ray photoelectron spectroscopy is 0.5 at% or less.

12. The ratio of silicon element attributable to silicone to all elements obtained by analyzing the first surface of the first functional layer before rubbing by X-ray photoelectron spectroscopy is C Ｓｉ The first surface of the first functional layer is rubbed under the following rubbing conditions, and the ratio of silicon element attributable to silicone to all elements obtained by analyzing the first surface of the first functional layer after rubbing by X-ray photoelectron spectroscopy is represented by C' Ｓｉ When expressed as: the rate of change ΔC of the silicon atom ratio represented by the following formula (2) Ｓｉ The optical laminate according to claim 11, wherein ΔC is 25.0% or less. Ｓｉ (%) = (C Ｓｉ -C' Ｓｉ ) / C Ｓｉ × 100 (2) [Rubbing conditions] Rubbing material: acetone-soaked cloth Load: 150 g / cm ２ Number of strokes: 5 (one way) 13. The optical laminate according to claim 11, wherein the first functional layer is a first refractive index layer, and the first refractive index layer contains hollow silica particles and solid silica particles.

14. The optical laminate according to claim 13, wherein the functional layer includes a second functional layer between the first functional layer and the substrate, and the second functional layer is a second refractive index layer having a higher refractive index than the first refractive index layer which is the first functional layer.

15. A polarizing plate having a polarizer, a first transparent protective plate arranged on one side of the polarizer, and a second transparent protective plate arranged on the other side of the polarizer, wherein one of the first transparent protective plate and the second transparent protective plate is an optical laminate described in claim 1 or claim 11, and the surface of the optical laminate facing the first functional layer faces away from the polarizer.

16. An image display panel having a display element and an optical film arranged on the light emission surface side of the display element, wherein the optical film comprises the optical laminate described in claim 1 or claim 11, and the surface of the optical laminate on the first functional layer side is arranged to face away from the display element.

17. An image display device comprising the image display panel according to claim 16.

Images