Optical laminate and article

Abstract

The present application provides an optical laminate and an article. In the optical laminate, a transparent substrate, a hard coat layer, and an antireflection layer are sequentially laminated, the antireflection layer is composed of a laminate in which a low-refractive-index material layer and a high-refractive-index material layer are alternately laminated, and a ＊ value and a b ＊ value of reflected light at the time of incidence at an incidence angle of 30° to 40° satisfy a condition A to a condition C and a condition E, the antireflection layer is a sputtering layer, the condition A: one or both of a ＊ value and a b ＊ value is 3 or less in absolute value, the condition B: one or both of a ＊ value and a b ＊ value satisfies a predetermined inequality, the condition C: one or both of a ＊ value and a b ＊ value is in a range of 5 or more and 15 or less in absolute value, the condition E: one or both of a ＊ value and a b ＊ value is in a range of 5 or more and 15 or less in absolute value, the condition E: one or both of a ＊ b ＊ value is in a range of 5 or more and 15 or less in absolute value, the condition E: one or both of a

Description

[0001] This application is a divisional application of the application filed on March 19, 2021, application number 2021800028236, titled "Optical laminate and article". TECHNICAL FIELD

[0002] The present application relates to an optical laminate and an article.

[0003] This application is based on Japanese Patent Application No. 2020-051220 filed on March 23, 2020, and Japanese Patent Application No. 2021-043915 filed on March 17, 2021, and the contents thereof are incorporated herein by reference. BACKGROUND

[0004] Image display devices such as flat panel displays (FPDs) are widely used for portable telephones, smartphones, car navigation devices, and the like.

[0005] In the conventional image display devices, it is required that color unevenness caused by the recognition angle is difficult to recognize. The color unevenness is a phenomenon in which the hue (chroma) looks different due to the recognition angle.

[0006] For example, Patent Literature 1 describes an antireflection film in which the visual sensitivity reflectance when light A of wavelengths of 380 nm to 780 nm emitted by a standard light source D65 is incident at an incident angle of 5° is 0.5% or less, and in the regular reflection light when the incident angle of the light A is changed in the range of 5° to 50°, the ratio of the difference between the maximum value and the minimum value of the b ＊ value in the CIE-Lab color system to the difference between the maximum value and the minimum value of the a ＊ value in the CIE-Lab color system (b ＊ value difference / a ＊ value difference) is 2 or more.

[0007] PRIOR ART DOCUMENTS

[0008] PATENT LITERATURE

[0009] Patent Literature 1: Japanese Patent Application Publication No. 2019-28364 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] The optical laminate such as an antireflection film provided on an image display device is preferably not easily colored with reflected light reflected by the image display device provided with the optical laminate. In addition, as the optical laminate, it is preferable that even if the recognition angle of the image display device provided with the optical laminate is changed, color unevenness is not recognized.

[0012] However, the conventional optical laminate sometimes recognizes color unevenness due to a recognition angle of an image display device in which the optical laminate is provided being different.

[0013] Therefore, in the conventional optical laminate provided on an image display device, it is required that reflected light reflected by the image display device is not easily colored, and color unevenness is hardly recognized even if the recognition angle of the image display device is changed.

[0014] The present application has been achieved in view of the above-described circumstances, and an object thereof is to provide an optical laminate which is provided on an article, reflected light reflected by the article is not easily colored, and color unevenness is hardly recognized even if the recognition angle of the article is changed.

[0015] In addition, an object of the present application is to provide an article which has the optical laminate of the present application, reflected light is not easily colored, and color unevenness is hardly recognized even if the recognition angle is changed.

[0016] Means for solving the problem

[0017] In order to solve the above-described problem, the present application proposes the following means.

[0018] [1] An optical laminate characterized by sequentially laminating a transparent substrate, a hard coat layer, and an antireflection layer,

[0019] The above-described antireflection layer is composed of a laminate in which a low-refractive-index material layer and a high-refractive-index material layer are alternately laminated, the high-refractive-index material layer is composed of a material having a higher refractive index than the low-refractive-index material layer,

[0020] The a ＊ value and the b ＊ value of reflected light when light having a wavelength of 380 nm to 780 nm emitted by a standard light source D65 is made incident satisfy the following (Condition A) to (Condition C).

[0021] (Condition A) The a ＊ value and the b ＊ value of the above-described reflected light when the above-described light is made incident to the surface of the above-described optical laminate at an incident angle of 30° to 40° are each 3 or less in absolute value.

[0022] (Condition B) The a ＊ value and the b ＊ value of the above-described reflected light when the above-described light is made incident to the surface of the above-described optical laminate at an incident angle of 5°, 10°, 20°, and 30° satisfy the following formula (B1).

[0023] {(|a ＊ | / |b ＊ |) of the a ＊| |b ＊ |) of the maximum value - {(|a ＊ | / |b ＊ |) of the minimum value} < 1.0...(B1)

[0024] (Condition C) one or both of the absolute values of the a ＊ value and the b ＊ value of the reflected light when the above light is incident on the surface of the above optical laminate at an incident angle of 5° are 5 or more, and the absolute values of the a ＊ value and the b ＊ value are 15 or less.

[0025] (Condition E) the a ＊ value and the b ＊ value of the reflected light in the CIE-Lab color system when the light is incident at an incident angle of 5° to 25° are in the same quadrant on the a ＊ b ＊ plane.

[0026] [2] The optical laminate according to [1], characterized in that the a ＊ value and the b ＊ value of the reflected light in the CIE-Lab color system when the above light is incident satisfy the following (Condition D).

[0027] (Condition D) the a ＊ value and the b ＊ value of the reflected light when the above light is incident on the surface of the above optical laminate at an incident angle of 5°, 10°, 20°, 30°, 40° satisfy the following formula (D1).

[0028] {(|a ＊ | / |b ＊ |) of the maximum value - {(|a ＊ | / |b ＊ |) of the minimum value} < 1.5...(D1)

[0029] [3] The optical laminate according to [2], in the above (Condition D), the a ＊ value and the b ＊ value of the reflected light when the above light is incident on the surface of the above optical laminate at an incident angle of 5°, 10°, 20°, 30°, 40° satisfy the following formula (D2).

[0030] {(|a ＊ | / |b ＊ |) of the maximum value - {(|a ＊ | / |b ＊ |) of the minimum value} < 1.0...(D2)

[0031] [4] The optical laminate according to [2], in the above (condition D), the a ＊ value and the b ＊ value of the reflected light when the above light is incident on the surface of the optical laminate at an incident angle of 5°, 10°, 20°, 30°, or 40° satisfy the following formula (D3).

[0032] {the maximum value of |a ＊ | / |b ＊ |) - {the minimum value of |a ＊ | / |b ＊ |) < 0.1... (D3)

[0033] [5] The optical laminate according to any one of [1] to [4], wherein the low refractive index material layer contains Si oxide, and the high refractive index material layer is composed of Nb2O5.

[0034] [6] The optical laminate according to [5], wherein the low refractive index material layer and the high refractive index material layer are formed by a sputtering method.

[0035] [7] The optical laminate according to any one of [1] to [6], wherein a stain-proof layer is laminated on the surface of the antireflection layer on the side opposite to the hard coat layer.

[0036] [8] The optical laminate according to [7], wherein the stain-proof layer contains a fluorine-based compound and is formed by an evaporation method or a coating method.

[0037] [9] An article characterized by comprising the optical laminate according to any one of [1] to [8].

[0038]

[10] The article according to [9], wherein the optical laminate is provided on the surface of an image display device.

[0039] Effects of the Invention

[0040] The optical laminate according to the present application, since the a ＊ value and the b ＊ value of the reflected light when the light having a wavelength of 380 nm to 780 nm emitted from the standard light source D65 is incident satisfy the synergistic effect of the above (condition A) to (condition C), it becomes an optical laminate provided on an article, which is not easily colored by the reflected light from the article, and which is difficult to recognize color unevenness even when the recognition angle of the article is changed.

[0041] Further, since the article of the present application comprises the optical laminate of the present application, the reflected light from the article is not easily colored, and it is difficult to recognize color unevenness even when the recognition angle is changed. BRIEF DESCRIPTION OF DRAWINGS

[0042] [ Figure 1 ] Figure 1 is a cross-sectional schematic view showing an example of the optical laminate of the present application.

[0043] [ Figure 2 ] Figure 2 is a graph showing the chromaticity of the reflected light when the optical laminate shown in ＊ a ＊ b ＊ Color space chromaticity diagram for explaining the a Figure 1 value and b ＊ value of the reflected light in the CIE-Lab colorimetric system when the optical laminate shown in ＊ is irradiated with light having wavelengths of 380 nm to 780 nm emitted by the standard light source D65.

[0044] [ Figure 3 ] Figure 3 is a graph showing the chromaticity of the reflected light when the surface of the optical laminate of Example 1 to Example 3, Comparative Example 1 to Comparative Example 3 is irradiated with light at an incident angle of 5°, 10°, 20°, 30°, 40°, and 50°.

[0045] [ Figure 4 ] Figure 4 is a graph showing the central portion of the graph of Figure 3 enlarged.

[0046] [ Figure 5 ] Figure 5 is a photograph of the test body when the surface of each optical laminate is irradiated with light at an incident angle of 5°, 10°, 20°, and 30°. DETAILED DESCRIPTION

[0047] To solve the above problem, the present inventors and others have repeatedly conducted in-depth research as shown below.

[0048] To obtain an optical laminate that is not easily colored by reflected light reflected by an article provided with the optical laminate, and that is difficult to recognize color unevenness even if the recognition angle of the article changes, the present inventors and others have repeatedly conducted in-depth research focusing on the relationship between the recognition angle of the article and the chromaticity (chroma and hue) of the reflected light.

[0049] As a result, it was found that even if the chroma of the reflected light when light is irradiated at a small incident angle of 5° or less to the surface is sufficiently small, if the chroma of the reflected light when light is irradiated at an incident angle of 30° to 40° is large, color unevenness due to a change in the recognition angle of the article is easily recognized. From this, it was learned that in order to suppress color unevenness due to a change in the recognition angle of the article, it is important to reduce the chroma of the reflected light when light having an incident angle of 30° to 40° is irradiated to the surface.

[0050] Further, the present inventors have found that, in terms of the ease of recognition of color unevenness, not only the chroma of the reflected light but also the hue change of the reflected light due to the change in the recognition angle has a large influence. Furthermore, the present inventors have acquired the knowledge that, by sufficiently reducing the chroma of the reflected light when light having an incident angle of 30° to 40° is incident to the surface and reducing the hue change of the reflected light when light in the range of an incident angle of 5° to 30° is incident, it is difficult to recognize color unevenness even when the recognition angle of the article is changed.

[0051] Further, the present inventors have found that, in the case where the chroma of the reflected light when light having an incident angle of 30° to 40° is incident to the surface and the hue change of the reflected light when light in the range of an incident angle of 5° to 30° is incident are sufficiently reduced, the coloring of the reflected light reflected by the article is difficult to recognize even when the chroma of the reflected light when light is incident at an incident angle of 5° is larger than that when light is incident at an incident angle of 30° to 40°.

[0052] Further, the present inventors have conducted repeated studies on the chroma range of the reflected light when light is incident at an incident angle of 30° to 40° and when light is incident at an incident angle of 5° to the surface of the optical laminate and the hue change of the reflected light when light in the range of an incident angle of 5° to 30° is incident to the surface, based on the above knowledge.

[0053] As a result, it has been found that, as long as the reflected light when light having a wavelength of 380 nm to 780 nm emitted from a standard light source D65 is incident satisfies the following (Condition A) to (Condition C) in the a ＊ value and the b ＊ value in the CIE-Lab color system, the optical laminate is acceptable. Thus, it has been conceived that such an optical laminate is less likely to cause the coloring of the reflected light reflected by the article and difficult to recognize color unevenness even when the recognition angle of the article is changed, thereby completing the present application. Further, it has been found that, if the following (Condition E) is satisfied, a more excellent optical laminate can be obtained.

[0054] (Condition A) the absolute values of the a ＊ value and the b ＊ value of the reflected light when the above light is incident at an incident angle of 30° to 40° to the surface of the above optical laminate are each 3 or less.

[0055] (Condition B) the a ＊ value and the b ＊ value of the reflected light when the above light is incident at an incident angle of 5°, 10°, 20°, and 30° to the surface of the above optical laminate satisfy the following formula (B1).

[0056] {(|a ＊ | / |b ＊ |) of the reflected light when the above light is incident at an incident angle of 5° to the surface of the above optical laminate is 0.2 or less.＊ | / |b ＊ The minimum value of |) is < 1.0...(B1)

[0057] (Condition C) When the light is incident on the surface of the optical laminate at an angle of incidence of 5°, the reflected light a ＊ Value and the above b ＊ If one or both of the values ​​are 5 or more in absolute terms, then the above a ＊ Value and the above b ＊ The value is in the range of 15 or less in absolute terms.

[0058] (Condition E) The reflected light when incident at angles of 5° to 25° in the CIE-Lab colorimetric system is a ＊ value and b ＊ Value in a ＊ b ＊ Within the same quadrant on the plane.

[0059] Hereinafter, the optical laminates and articles of the present invention will be described with reference to the accompanying drawings as appropriate. Figure 1 The following is a detailed description. The accompanying drawings used in this description are sometimes enlarged to facilitate understanding of the features of the invention, and the dimensions and proportions of the constituent elements may differ from the actual dimensions. The materials, dimensions, etc., illustrated in the following description are examples only; the invention is not limited to these and can be implemented with appropriate modifications to achieve the desired effect.

[0060] [Optical laminate]

[0061] Figure 1 This is a cross-sectional schematic diagram illustrating an example of the optical laminate of the present invention.

[0062] Figure 1 The optical laminate 1 shown consists of a transparent substrate 2, a hard coating 3, an anti-reflective layer 4 (laminated body), and an anti-fouling layer 5, stacked sequentially.

[0063] Figure 2 The optical laminate 1 shown is disposed on an article (not shown). Examples of articles include those having the optical laminate 1 on the surface of an image display device (not shown).

[0064] Figure 1 It is used to explain the Figure 2 The optical laminate shown is subjected to light with wavelengths of 380nm to 780nm emitted from a standard light source D65. The reflected light in the CIE-Lab colorimetric system is a. ＊ value and b ＊ The value of the graph. Figure 2 In the middle, a ＊ value and b ＊ The value represents chroma; the higher the value, the more chroma it represents.＊ value and b ＊ The coordinate with the larger the absolute value of the color, the greater its saturation. That is, in... Figure 2 In the middle, the more a ＊ value and b ＊ The larger the absolute value of the coordinate, the more vibrant the color; the more vibrant the color, the more likely it is to be a. ＊ value and b ＊ The smaller the absolute value of the coordinate, the closer it is to an achromatic color.

[0065] +a ＊ The coordinates are the hue in the red direction, -a ＊ The coordinates are the hue in the green direction, +b ＊ The coordinates are the hue in the yellow direction, -b ＊ The coordinates are the hue in the blue direction. Figure 1 L ＊ a ＊ b ＊ In the chromaticity diagram, the first quadrant (+a) ＊ +b ＊ ), Quadrant 2 (-a) ＊ +b ＊ ), Quadrant 3 (-a) ＊ -b ＊ Quadrant 4 (+a) ＊ -b ＊ The hues of the reflected light correspond to red to orange to yellow, yellow to yellowish-green to green, green to blue-green to blue, and blue to purple to red, respectively. Therefore, if the hue of the reflected light changes to another quadrant depending on the angle of incidence (quadrant crossing), the color unevenness is easily noticeable due to the significant change in hue. Preferably, the hue of the reflected light should not change quadrant depending on the angle of incidence; in other words, it is preferable that the hue of the reflected light remains within the same quadrant regardless of the angle of incidence.

[0066] about Figure 1 The optical laminate 1 shown, when incident with light of wavelengths 380nm to 780nm emitted from a standard light source D65, displays the reflected light in the CIE-Lab colorimetric system. ＊ value and b ＊ The value satisfies the above conditions (A) to (C). Each of the above conditions (A) to (C) can be adjusted by appropriately selecting the material and thickness for each layer of the transparent substrate 2, hard coating 3, anti-reflective layer 4 and anti-fouling layer 5 that form the optical laminate 1.

[0067] about Figure 2 The optical laminate 1 shown, when incident light is incident on the surface of the optical laminate 1 at an angle of incidence of 30° to 40°, has the following reflected light a ＊ value and b＊ The values, expressed in absolute terms, are 3 or less. Figure 1 In the region represented by symbol A (condition A). Therefore, regarding the optical laminate 1 of this embodiment, the chroma of the reflected light when incident light is at an incident angle of 30° to 40° is sufficiently small, making it difficult to discern color unevenness caused by changes in the viewing angle of the article. Preferably, the above a ＊ value and b ＊ The values, in absolute terms, are 2.5 or less. In this case, the optically laminated body 1 becomes even more difficult to discern due to color unevenness caused by changes in the viewing angle of the object. If the above a ＊ value and b ＊ If any one or both of these values ​​exceed 3 in absolute terms, the chroma of the reflected light when incident at an angle of 30° to 40° increases, making it easier to identify color unevenness caused by changes in the viewing angle of the object.

[0068] about Figure 2 The optical laminate 1 shown, when light is incident on the surface of the optical laminate 1 at incident angles of 5°, 10°, 20°, and 30°, the reflected light α ＊ value and b ＊ The value satisfies the following equation (B1) (condition B).

[0069] {(|a ＊ | / |b ＊ The maximum value of |)}-{(|a ＊ | / |b ＊ The minimum value of |) is < 1.0...(B1)

[0070] |a ＊ | / |b ＊ | is a numerical value corresponding to the color of the reflected light. |a satisfies the above conditions. ＊ | / |b ＊ The optical laminate 1 of formula (B1), where the difference between the maximum and minimum values ​​of | is less than 1.0, exhibits small hue changes in reflected light when incident light is incident at angles of 5° to 30°. That is, the hues of the reflected light are similar when incident light is incident at angles of 5° to 30°. Therefore, with respect to the optical laminate 1 of this embodiment, the hue change of reflected light caused by changes in the viewing angle of the article is small, making it difficult to detect color unevenness. In contrast, when the optical laminate 1 does not satisfy the above (condition B), the hue change of reflected light caused by changes in the viewing angle of the article is large, making it easy to detect color unevenness. The above |a ＊ | / |b ＊ The difference between the maximum and minimum values ​​of | is preferably 0.5 or less, and more preferably 0.3 or less.

[0071] The optical laminate 1 of this embodiment satisfies conditions (A) and (B) above, thus ensuring that the chroma of the reflected light is sufficiently small when the light is incident at an angle of 30° to 40°. Figure 1 In the region represented by symbol A), the hue change of the reflected light when light is incident at an angle of incidence of 5° to 30° is sufficiently small (satisfying equation (B1)). The chroma (chroma and hue) of the reflected light of the optical laminate 1 changes continuously as the viewing angle of the object changes. Therefore, the optical laminate 1 that satisfies the above (condition A) and (condition B) has, for example, similar hues in the reflected light when light is continuously incident at an angle of incidence of 5° to 30°, and shows a tendency for the chroma to decrease as the angle of incidence increases. Since the chroma of the reflected light of the optical laminate 1 of this embodiment is sufficiently small when light is incident at an angle of incidence of 30° to 40° (condition A), even if the hue of the reflected light at an angle of incidence of 30° to 40° is different from that at an angle of incidence of 5° to 30°, it is difficult to perceive color unevenness. Therefore, the optical laminate 1 of this embodiment is difficult to perceive color unevenness caused by changes in the viewing angle of the object.

[0072] about Figure 2 The optical laminate 1 shown, when light is incident on the surface of the optical laminate 1 at an incident angle of 5°, has a reflected light a ＊ value and b ＊ If one or both of the values ​​are 5 or higher in absolute terms, then a ＊ value and b ＊ The value is in the range of 15 or less in absolute terms (condition C). Figure 2 In the symbol C, a represents a ＊ value and b ＊ The range where the value is between 5 and 15 in absolute terms.

[0073] The optical laminate 1 of this embodiment, due to the above a ＊ value and b ＊ Values ​​below 15 in absolute terms are therefore difficult to discern in terms of the coloration of reflected light from the object. (a) ＊ value and b ＊ The values ​​are preferably 10 or less in absolute terms. In this case, the optical laminate 1 becomes even more difficult to discern in terms of the color of the reflected light reflected by the object.

[0074] The optical laminate 1 of this embodiment satisfies conditions (A) and (B) above, therefore, even when light is incident at an angle of 5°, the chroma of the reflected light is higher than when light is incident at an angle of 30° to 40°. Figure 2 In the middle, the outer side of the area represented by the symbol A (e.g., Figure 1 In the area represented by the symbol C, the coloration of the reflected light from the object is also difficult to discern. However, if the above a ＊ value and b＊ Either or both of the values exceeds 15 in absolute value, the chromaticity of the reflected light at the time of incidence of light at an incident angle of 5° is large, and thus the coloring of the reflected light reflected by the article is easily recognized.

[0075] Further, regarding the optical laminate 1 illustrated in Figure 2 the optical laminate 1, the a ＊ value and the b ＊ value of the reflected light at the time of incidence of light at an incident angle of 5° on the surface of the optical laminate 1 are one or both of 5 or more in absolute value (condition C). Thus, for example, compared to the case where one or both of the a ＊ value and the b ＊ value of the reflected light at the time of incidence of light at an incident angle of 5° on the surface of the optical laminate 1 are less than 3 Figure 1 , the options of the materials and thicknesses of the layers forming the optical laminate 1, the manufacturing method become more, and it is possible to easily and efficiently manufacture. Further, the a ＊ value and the b ＊ value of the reflected light at the time of incidence of light at an incident angle of 5° on the surface of the optical laminate 1 are one or both of 8 or more in absolute value. In this case, the options of the materials and thicknesses of the layers forming the optical laminate 1, the manufacturing method become more, and it is possible to more easily and efficiently manufacture.

[0076] Further, regarding the optical laminate 1 illustrated in Figure 1 the optical laminate 1, the a ＊ value and the b ＊ value of the reflected light at the time of incidence of light at an incident angle of 5° to 25° in the CIE-Lab color system are in the same quadrant on the a ＊ b ＊ plane (La ＊ b ＊ chromaticity diagram) (condition E).

[0077] Thus, for example, in the case where a display device provided with the optical laminate of the present application is provided in the auxiliary panel of an automobile or the like, or in the case where it is provided in the front headliner of the rear seat, the hue change at the time of recognition from the rear seat is small, and it is most suitable as these uses.

[0078] Regarding the optical laminate 1 illustrated in Figure 1 the optical laminate 1, it is preferable that the a ＊ value and the b ＊ value of the reflected light at the time of incidence of light at an incident angle of 5°, 10°, 20°, 30°, 40° on the surface of the optical laminate 1 satisfy the following formula (D1) (condition D).

[0079] {the maximum value of |a ＊ | / |b ＊ |) - {the maximum value of |a ＊ | / |b ＊The minimum value of |) is < 1.5...(D1)

[0080] Satisfying the above |a ＊ | / |b ＊ The optical laminate 1 of formula (D1), where the difference between the maximum and minimum values ​​of | is less than 1.5, exhibits minimal hue variation in reflected light when incident at angles of 5° to 40°. That is, the hues of reflected light are similar when incident at angles of 5° to 40°. Therefore, with respect to the optical laminate 1 of this embodiment, the hue variation of reflected light caused by changes in the viewing angle of the article is small, further making it difficult to detect color unevenness.

[0081] a) of the reflected light when incident on the surface of optical laminate 1 at incident angles of 5°, 10°, 20°, 30°, and 40° ＊ value and b ＊ The value preferably satisfies the following formula (D2), and more preferably satisfies the following formula (D3). When the optical laminate 1 satisfies formula (D2) or formula (D3), the hue change of the reflected light caused by the change of the viewing angle of the article becomes smaller, and the optical laminate 1 becomes even more difficult to discern due to the uneven color caused by the change of the viewing angle of the article.

[0082] {(|a ＊ | / |b ＊ The maximum value of |)}-{(|a ＊ | / |b ＊ The minimum value of |) is < 1.0 (D2)

[0083] {(|a ＊ | / |b ＊ The maximum value of |)}-{(|a ＊ | / |b ＊ The minimum value of |) is < 0.1 (D3)

[0084] (Transparent substrate)

[0085] As formed Figure 1 The transparent substrate 2 of the optical laminate 1 shown can be a known transparent substrate.

[0086] The transparent substrate 2 is made of a transparent material that can transmit light in the visible light region. In this embodiment, "transparent material" refers to a material with a light transmittance of 80% or more in the visible light region.

[0087] As the transparent substrate 2, for example, a plastic film can be used. As the material of the plastic film, polyester-based resins, acetate-based resins, polyether sulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyolefin-based resins, (meth)acrylic-based resins, polyvinyl chloride-based resins, polyvinylidene chloride-based resins, polystyrene-based resins, polyvinyl alcohol-based resins, polyarylate-based resins, polyphenylene sulfide-based resins, and the like can be exemplified. Among them, as the material of the plastic film, it is preferable to use any one or two or more selected from the group consisting of polyester-based resins, acetate-based resins, polycarbonate-based resins, polyolefin-based resins, and particularly preferable to use triacetyl cellulose (TAC).

[0088] In addition, the transparent substrate 2 can also contain a reinforcing material within the limit of not impairing the optical properties. As the reinforcing material, for example, cellulose nanofiber, nanosilica, and the like can be exemplified.

[0089] In addition, as the transparent substrate 2, an inorganic material such as a glass film can also be used.

[0090] As the transparent substrate 2, a film imparted with an optical function and / or a physical function can also be used as needed. As the film having an optical function and / or a physical function, for example, a polarizing plate film, a phase difference compensation film, a heat ray blocking film, a conductive film, a brightness enhancement film, and the like can be exemplified. Further, as the transparent substrate 2, a transparent substrate imparted with a function such as an antistatic function and the like to a film having an optical function and / or a physical function can also be used.

[0091] The thickness of the transparent substrate 2 is, for example, preferably 25 μm or more, and more preferably 40 μm or more. If the thickness of the transparent substrate 2 is 25 μm or more, wrinkles are less likely to occur even if stress is applied to the optical laminate 1, and thus it is preferable. In addition, if the thickness of the transparent substrate 2 is 25 μm or more, even if a hard coat layer 3 is formed on the transparent substrate 2 when the optical laminate 1 is manufactured, wrinkles are less likely to occur on the transparent substrate 2, and thus the product can be manufactured with a high yield. In addition, if the thickness of the transparent substrate 2 is 25 μm or more, the optical laminate 1 during the manufacturing process is less likely to be curled, and thus it is easy to mount, and thus it is preferable.

[0092] The thickness of the transparent substrate 2 is, for example, preferably 300 μm or less, and more preferably 250 μm or less. If the thickness of the transparent substrate 2 is 300 μm or less, it is possible to prevent the thickness of the transparent substrate 2 from being too thick to hinder the thinning and the lightening of the optical laminate 1. In addition, if the thickness of the transparent substrate 2 is 300 μm or less, it is possible to efficiently manufacture the optical laminate 1 using the transparent substrate 2 wound in a roll shape. In addition, if the thickness of the transparent substrate 2 is 300 μm or less, when the hard coat layer 3 is formed on the transparent substrate 2, water and organic substances are less likely to be generated from the transparent substrate 2, and thus the product can be manufactured with a high yield.

[0093] The method of manufacturing the transparent substrate 2 is not particularly limited, and the transparent substrate 2 can be manufactured by a publicly known manufacturing method.

[0094] As the transparent substrate 2, a transparent substrate subjected to surface treatment can also be used. As the surface treatment method, for example, sputtering, corona discharge, ultraviolet irradiation, electron beam irradiation, chemical conversion, etching treatment such as oxidation, primer treatment, and the like can be exemplified. By subjecting the transparent substrate 2 to surface treatment using any one or two or more of these surface treatment methods, a transparent substrate 2 having good adhesion to the hard coat layer 3 can be obtained.

[0095] In addition, the transparent substrate 2 can also be surface-cleaned as needed before the hard coat layer 3 is formed on the transparent substrate 2. As the surface cleaning method for the transparent substrate 2, for example, solvent cleaning, ultrasonic cleaning, and the like can be exemplified. By performing cleaning of the transparent substrate 2, the surface of the transparent substrate 2 can be dusted and cleaned, and thus is preferable.

[0096] (Hard Coat Layer)

[0097] As the hard coat layer 3, a publicly known hard coat layer can be used, and for example, a hard coat layer containing a binder resin and a filler can be exemplified. The hard coat layer 3 can also contain a publicly known material such as a leveling agent, as needed, in addition to the binder resin and the filler.

[0098] As the binder resin contained in the hard coat layer 3, a transparent material is preferable. As the binder resin, for example, an ionizing radiation-curable resin, a thermoplastic resin, a thermosetting resin, and the like can be used. The binder resin can be used alone or two or more kinds can be mixed and used.

[0099] As the ionizing radiation-curable resin, for example, ethyl (meth)acrylate, ethylhexyl (meth)acrylate, styrene, methylstyrene, N-vinylpyrrolidone, urethane acrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), and pentaerythritol tetraacrylate (PETTA), and the like can be exemplified. As the ionizing radiation-curable resin, a substance obtained by modifying the above compounds with PO (propylene oxide), EO (ethylene oxide), CL (caprolactone), and the like can also be used.

[0100] In the present embodiment, "(meth)acrylate" means methacrylate and / or acrylate.

[0101] In the case where an ionizing radiation-curable resin is included as the adhesive resin, the hard coat layer 3 can also include a publicly known ionizing radiation-curable initiator. For example, in the case where an ultraviolet-curable resin such as a (meth)acrylate is included as the ionizing radiation-curable resin, an ultraviolet-curable initiator such as a hydroxy-cyclohexyl-phenyl-ketone is preferably included.

[0102] As the thermoplastic resin, for example, a styrene resin, a (meth)acrylic resin, a vinyl acetate resin, a vinyl ether resin, a halogen-containing resin, an alicyclic olefin resin, a polycarbonate resin, a polyester resin, a polyamide resin, a cellulose derivative, a silicone resin, or the like can be exemplified.

[0103] As the thermosetting resin, for example, a phenol resin, a urea resin, a diallyl phthalate resin, a melamine resin, a guanamine resin, an unsaturated polyester resin, a polyurethane resin, an epoxy resin, an amino alkyd resin, a melamine-urea co-condensation resin, a silicon resin, a polysiloxane resin (including so-called silsesquioxane and the like having a cage shape, ladder shape, or the like), or the like can be exemplified.

[0104] The filler included in the hard coat layer 3 can be selected from various fillers depending on the use of the optical laminate 1 from the viewpoints of anti-glare property, adhesion to the antireflection layer 4 described later, and blocking resistance. Specifically, for example, publicly known particles such as silica (oxide of Si) particles, alumina (aluminum oxide) particles, and organic fine particles can be used.

[0105] From the viewpoint of improving the anti-glare property of the optical laminate 1, as the filler, organic fine particles composed of an acrylic resin or the like are preferably used. The particle diameter of the organic fine particles is preferably 10 μm or less, further preferably 5 μm or less, and particularly preferably 3 μm or less.

[0106] From the viewpoint of improving the adhesion to the antireflection layer 4, as the filler, silica particles are preferably used. The particle diameter of the silica particles is preferably 800 nm or less, and particularly preferably 100 nm or less.

[0107] The thickness of the hard coat layer 3 is, for example, preferably 0.5 μm or more, and more preferably 1 μm or more. The thickness of the hard coat layer 3 is preferably 100 μm or less.

[0108] The hard coat layer 3 can be composed of a single layer, or can be laminated by a plurality of layers.

[0109] The manufacturing method of the hard coating 3 is not particularly limited and can be manufactured by known methods. For example, the hard coating 3 can be manufactured by a coating method. Examples of coating methods include applying a coating liquid to a transparent substrate 2 using known methods and then curing it. This coating liquid is obtained by dissolving and / or dispersing the material forming the hard coating 3 in a solvent. Known solvents can be used, and the appropriate solvent can be selected depending on the material forming the hard coating 3.

[0110] (Anti-reflective layer)

[0111] The anti-reflective layer 4 is composed of a laminate made by alternately stacking low-refractive-index material layers 4a and 4c and a high-refractive-index material layer 4b, wherein the high-refractive-index material layer 4b is made of a material with a refractive index higher than that of the low-refractive-index material layers 4a and 4c. The anti-reflective layer 4 diffuses light incident on the optical laminate 1 from the anti-fouling layer 5 side. Thus, the optical laminate 1 functions as an anti-reflective film to prevent light incident on the optical laminate 1 from the anti-fouling layer 5 side from being reflected and emitted in one direction.

[0112] In the low-refractive-index material layers 4a and 4c that form the anti-reflective layer 4, the low-refractive-index material layer 4a, which is disposed in contact with the hard coating layer 3, functions as an adhesive layer that seals the anti-reflective layer 4 with the hard coating layer 3. Furthermore, in Figure 1 In the optical laminate 1 shown, a low refractive index material layer 4c is disposed on the surface of the antireflective layer 4 opposite to the hard coating layer 3 and in contact with the antifouling layer 5.

[0113] In this embodiment, such as Figure 1 As shown, the example given is a case where the antireflective layer 4 is composed of five layers stacked sequentially from the hard coating layer 3 side: a low-refractive-index material layer 4a, a high-refractive-index material layer 4b, a low-refractive-index material layer 4c, a high-refractive-index material layer 4b, and a low-refractive-index material layer 4c. The number of layers forming the antireflective layer 4 (low-refractive-index material layers 4a, 4c, and high-refractive-index material layer 4b) is not limited to five; it can be less than or more than five layers, depending on the required optical properties of the antireflective layer 4.

[0114] When the laminate forming the antireflective layer 4 contains two or more low-refractive-index material layers 4a and 4c, the multiple low-refractive-index material layers 4a and 4c can all have the same refractive index, or some or all of them can have different refractive indices.

[0115] When the laminate forming the antireflective layer 4 contains two or more high refractive index material layers 4b, the multiple high refractive index material layers 4b can all have the same refractive index, or some or all of them can have different refractive indices.

[0116] The low refractive index material layer 4a, 4c preferably has a refractive index of 1.20 to 1.60, more preferably 1.30 to 1.50.

[0117] The low refractive index material layer 4a, 4c preferably has SiO2(Si oxide) as a main component. The low refractive index material layer 4a, 4c can be composed of only Si oxide, or can contain other elements in a range of 50 mass% or less, preferably 10 mass% or less, in addition to Si oxide. As the other elements, Na can be contained in order to improve the durability of the low refractive index material layer 4a, 4c, and one or two or more elements selected from Zr, Al, and N can be contained in order to improve the hardness of the low refractive index material layer 4a, 4c.

[0118] The high refractive index material layer 4b preferably has a refractive index of 2.00 to 2.60, more preferably 2.10 to 2.45.

[0119] As the high refractive index material layer 4b, for example, a material layer composed of niobium pentoxide (Nb2O5, refractive index 2.33), titanium oxide (TiO2, refractive index 2.33 to 2.55), tungsten oxide (WO3, refractive index 2.2), cerium oxide (CeO2, refractive index 2.2), tantalum pentoxide (Ta2O5, refractive index 2.16), zinc oxide (ZnO, refractive index 2.1), indium tin oxide (ITO, refractive index 2.06), or the like, preferably a material layer composed of niobium pentoxide.

[0120] The film thickness of the low refractive index material layer 4a, 4c and the high refractive index material layer 4b constituting the antireflection layer 4 can be appropriately determined in accordance with the optical characteristics required of the antireflection layer 4. The film thickness of the low refractive index material layer 4a, 4c and the high refractive index material layer 4b can be the same throughout, or can be different for some or all of them.

[0121] The film thickness of the low refractive index material layer 4a, 4c can be, for example, 1 nm or more and 200 nm or less. In the case where the antireflection layer 4 contains two or more low refractive index material layers 4a, 4c, the plurality of low refractive index material layers 4a, 4c can all have the same film thickness, or the film thickness can be different for some or all of them.

[0122] The film thickness of the high refractive index material layer 4b can be, for example, 1 nm or more and 200 nm or less. In the case where the antireflection layer 4 contains two or more high refractive index material layers 4b, the plurality of high refractive index material layers 4b can all have the same film thickness, or the film thickness can be different for some or all of them.

[0123] The film thickness of the low refractive index material layers 4a, 4c and the high refractive index material layers 4b can be, for example, 30 to 120 nm of the low refractive index material layer 4a, 10 to 50 nm of the high refractive index material layer 4b, 30 to 120 nm of the low refractive index material layer 4c, 50 to 200 nm of the high refractive index material layer 4b, and 50 to 200 nm of the low refractive index material layer 4c, in this order from the hard coat layer 3 side.

[0124] The method for producing the antireflection layer 4 is not particularly limited and can be produced by a publicly known production method. The antireflection layer 4 can be produced, for example, by a method in which the low refractive index material layer 4a, the high refractive index material layer 4b, the low refractive index material layer 4c, the high refractive index material layer 4b, and the low refractive index material layer 4c are sequentially formed on the hard coat layer 3 by a sputtering method.

[0125] In the case where the low refractive index material layers 4a, 4c and the high refractive index material layers 4b are formed by a sputtering method, they become denser than in the case where a vacuum evaporation method or a coating method is generally used. As a result, the optical laminate 1 having a water vapor permeability of 1.0 g / m 2 / day or less and excellent durability is obtained.

[0126] (Antifouling layer)

[0127] The antifouling layer 5 can be provided on the side of the antireflection layer 4 opposite to the hard coat layer 3 as needed. The antifouling layer 5 prevents fouling of the optical laminate 1 and suppresses the deterioration of the antireflection layer 4.

[0128] The antifouling layer 5 preferably contains a fluorine-based compound. As the fluorine-based compound, for example, a compound composed of a reactive silyl group of a fluorine-modified organic group and an alkoxysilane or the like is preferably used. As such a compound, perfluorodecyltriethoxysilane (FDTS) or the like can be exemplified.

[0129] As a commercially available product suitable as the material of the antifouling layer 5, OPTOOL DSX (manufactured by Daikin Industries, Ltd.), KY-1203 (manufactured by Shin-Etsu Chemical Co., Ltd.), and the like can be exemplified.

[0130] The antifouling layer 5 can also contain, as needed, an additive such as a light stabilizer, an ultraviolet absorber, a colorant, an antistatic agent, a lubricant, a leveling agent, an antifoaming agent, an antioxidant, a flame retardant, an infrared absorber, a surfactant, and the like.

[0131] The thickness of the antifouling layer 5 can be, for example, 1 to 20 nm, and is preferably 3 to 10 nm.

[0132] The method of producing the stain-proof layer 5 is not particularly limited, and can be produced by a publicly known production method, and is appropriately selected in consideration of the required durability and cost. Specifically, the stain-proof layer 5 can be produced by a coating method or a vapor deposition method. As the coating method, for example, a method of applying a coating liquid obtained by dissolving a material forming the stain-proof layer 5 in a solvent to the antireflection layer 4 and drying, and the like can be exemplified. In addition, in the case where the stain-proof layer 5 is formed by a vapor deposition method, for example, compared to the stain-proof layer formed using a coating method, the stain-proof layer becomes dense and has excellent adhesion to the antireflection layer 4. Therefore, the stain-proof layer 5 formed by a vapor deposition method has high abrasion resistance.

[0133] In the optical laminate 1 of the present embodiment, one or more layers can be provided on the surface of the transparent substrate 2 on the side opposite to the antireflection layer 4 as needed. For example, an adhesive layer for bonding the optical laminate 1 to the surface of an image display device or other member can be provided on the surface of the transparent substrate 2 on the side opposite to the antireflection layer 4, and an adhesive layer and other optical film can be sequentially stacked. As the other optical film, for example, a polarizing film, a phase difference compensation film, a 1 / 2 wavelength plate, a 1 / 4 wavelength plate, and the like can be exemplified. In addition, the above other optical film can be formed in contact with the surface of the transparent substrate 2 on the side opposite to the antireflection layer 4.

[0134] The optical laminate 1 of the present embodiment sequentially stacks the transparent substrate 2, the hard coat layer 3, and the antireflection layer 4, and the antireflection layer 4 is composed of a laminate in which the low refractive index material layers 4a, 4c and the high refractive index material layer 4b are alternately stacked, and the high refractive index material layer 4b is composed of a material having a higher refractive index than the low refractive index material layers 4a, 4c. Furthermore, regarding the optical laminate 1 of the present embodiment, the a ＊ value and the b ＊ value of the reflected light when light having a wavelength of 380 nm to 780 nm emitted by a standard light source D65 is incident satisfy the above (Condition A) to (Condition C). According to the optical laminate 1 of the present embodiment, due to the synergistic effect of satisfying the above (Condition A) to (Condition C), it becomes an optical laminate provided on an article, which is less likely to color the reflected light reflected by the article, and it is difficult to recognize color unevenness even if the recognition angle of the article is changed.

[0135] [Article]

[0136] The article of the present embodiment is provided with the optical laminate 1 of the present embodiment. The article of the present embodiment can be an article in which the optical laminate 1 is provided on the surface of an image display device. As the image display device, for example, a liquid crystal display panel, an organic electroluminescence (EL) display panel, and the like flat panel display (FPD) can be exemplified.

[0137] As the surface of an image display device to which the optical laminate 1 of the present embodiment is attached, for example, a screen of a mobile phone, a screen of a smartphone, a screen of a tablet terminal, a display of a personal computer, a screen of a navigation system, a screen of an information input terminal such as an operation screen of a game machine, an operation screen of a running support device such as an airplane or an electric train, an electronic display board, and the like can be exemplified. Among these, the image display device to which the optical laminate 1 is attached is preferably an image display device that can be recognized at various recognition angles at the time of use, and particularly preferably a screen of a navigation system, a screen of a mobile phone, a screen of a smartphone.

[0138] The article of the present embodiment is not limited to an article in which the optical laminate 1 is provided to the surface of an image display device. For example, a window glass, a goggle, a light-receiving surface of a solar cell, a glass workbench surface, an instrument panel, a surface of an optical sensor, a visor of a safety helmet, a mirror, a head-mounted display, and the like having a surface provided with the optical laminate 1 of the present embodiment can be exemplified. The surface of the article of the present embodiment provided with the optical laminate 1 can be a flat plate shape or a curved surface shape.

[0139] The article of the present embodiment, since the optical laminate 1 of the present embodiment is provided, reflected light from the article is less likely to be colored, and color unevenness is difficult to recognize even if the recognition angle changes.

[0140] The article of the present embodiment, in a case where the optical laminate 1 is provided to the surface of an image display device, reflected light from the image display device is less likely to be colored, and color unevenness is difficult to recognize even if the recognition angle changes, and thus is preferable.

[0141] Example

[0142] (Example 1 to Example 3, Comparative Example 1, Comparative Example 3)

[0143] The optical laminate 1 shown below was produced by the following method. Figure 3 The optical laminate 1 shown below was produced by the following method.

[0144] First, as the transparent substrate 2, a film composed of triacetyl cellulose (TAC) having a thickness of 80 μm was prepared. Then, a hard coat layer 3 composed of a material shown in Table 1 having a thickness of 5 μm was formed on the transparent substrate 2.

[0145] [Table 1]

[0146]

[0147] "CHC" shown in Table 1 was formed by a method of applying a coating liquid having a composition shown in Table 2 to the transparent substrate 2 using a bar coater, and curing it by irradiation of ultraviolet rays.

[0148] [Table 2]

[0149]

[0150] In addition, "AG-HC" shown in Table 1 is formed by a method of applying a coating liquid having the composition shown in Table 3 to the transparent substrate 2 using a bar coater and curing it by photopolymerization by irradiation of ultraviolet rays.

[0151] [Table 3]

[0152]

[0153] Next, the antireflection layer 4 (laminate) was formed on the hard coat layer 3 by a reactive sputtering method using a Si target and a Nb target as sputtering targets and using a mixed gas of Ar gas and O2 gas. That is, a low refractive index material layer 4a (1st layer) having the film thickness shown in Table 1 and composed of Si oxide in which oxygen defects can exist, a high refractive index material layer 4b (2nd layer) composed of Nb2O5 having the film thickness shown in Table 1, a low refractive index material layer 4c (3rd layer) composed of SiO2 having the film thickness shown in Table 1, a high refractive index material layer 4b (4th layer) composed of Nb2O5 having the film thickness shown in Table 1, and a low refractive index material layer 4c (5th layer) composed of SiO2 having the film thickness shown in Table 1 were sequentially and repeatedly formed on the hard coat layer 3.

[0154] Next, the antifouling layer 5 having a film thickness of 10 nm was formed by a method of applying a coating liquid on the antireflection layer 4 using a wire bar (product name: No. 579, bar No. 9, made by Yasuda Seiki Mfg. Co., Ltd.) in such a manner that the film thickness of the applied film becomes 10 μm, and drying it at 80°C for 2 minutes. As the coating liquid, a solution containing 0.1 mass% of an alkoxysilane compound having a perfluoropolyether group (trade name: OPTOOL DSX, made by Daikin Industries, Ltd.) in a fluorine solvent (trade name: Fluorinert FC-3283, made by 3M Japan Limited) was used.

[0155] By the above procedures, the optical laminates of Examples 1 to 3, Comparative Example 1, and Comparative Example 3 were produced.

[0156] (Comparative Example 2)

[0157] The optical laminate of Comparative Example 2 was produced by performing the procedures up to the formation of the antireflection layer 4, similarly to Examples 1 to 3, Comparative Example 1, and Comparative Example 3.

[0158] (Comparative Example 4)

[0159] In the production of the optical laminate of Comparative Example 4, as the transparent substrate 2, a film composed of triacetyl cellulose (TAC) having a thickness of 80 μm was prepared, and a high refractive index layer and a low refractive index layer were formed on the substrate using a coating method.

[0160] (Modification of coating liquid for high refractive index layer)

[0161] A dipentaerythritol hexaacrylate, an EO-modified isocyanuric acid diacrylate, and dimethylol tricyclodecane diacrylate, antimony trioxide, and an initiator (1-hydroxy-cyclohexyl-phenyl-ketone) were dissolved in isopropyl alcohol as a solvent so that the solid content became 40% by weight, and a coating liquid for a high refractive index layer was prepared. Note that the solid content refers to substances other than the solvent in the coating liquid, and here refers to the photopolymerizable prepolymer such as dipentaerythritol hexaacrylate, antimony trioxide, and the initiator.

[0162] The coating liquid for the high refractive index layer was applied to the surface of a triacetyl cellulose film (film thickness: 80 μm) as a transparent substrate by a gravure method so that the dry film thickness became 4 μm, and after drying in an oven at 80°C for 1 minute and 30 seconds, light from a 160W high-pressure mercury lamp was irradiated for 3 seconds from a distance of 18 cm, and the coating liquid was cured, and a high refractive index layer was formed. The high refractive index layer also functions as a hard coat layer.

[0163] (Modification of coating liquid for low refractive index layer)

[0164] In order to form a low refractive index layer, the following coating liquid was prepared.

[0165] A 4% by weight polyester acrylate oligomer, 18% by weight pentaerythritol tetraacrylate, 28.5% by weight polyethylene glycol diacrylate at a blending ratio, 40% by weight hollow silica particles with an average particle diameter of 60 nm, 8% by weight α-hydroxy ketone-based initiator, and 1.5% by weight modified organosilicon compound (functional group equivalent weight: 3900 g / mol) were added, and a low refractive index coating agent (polymerizable composition) was prepared.

[0166] The low refractive index coating agent was dissolved and dispersed in n-butanol as a solvent, and a coating liquid for a low refractive index layer was prepared so that the solid content (low refractive index coating agent) was 3.0% by weight.

[0167] The coating liquid for the low refractive index layer was applied to the surface of the high refractive index layer using a gravure method so that the dry film thickness became 100 nm, and a coating layer was formed, and after drying in an oven at 80°C for 1 minute and 30 seconds, light from a 160W high-pressure mercury lamp was irradiated for 3 seconds from a distance of 18 cm in a nitrogen atmosphere (oxygen concentration: 1000 ppm), and the coating layer was cured, and a low refractive index layer was formed, and a antireflection film of Comparative Example 4 was obtained.

[0168] (Comparative Example 5)

[0169] An optical layer stack of Comparative Example 5 was obtained by the production method described in Japanese Patent Application Publication No. 2019-70756.

[0170] "Measurement of color of reflected light"

[0171] The surface of the optical laminate of Example 1 to Example 3, Comparative Example 1 to Comparative Example 5 on the side of the transparent substrate 2 thus obtained was attached to the surface of a black acrylic plate using an acrylic transparent adhesive, respectively, to produce a test body from which the back reflection could be removed. Then, from the surface of each optical laminate on the side opposite to the transparent substrate 2, the color of the reflected light was calculated from the reflection spectrum using a calculation formula, using a spectrophotometer V-550 manufactured by Japan Spectroscopic Co., Ltd., with light of wavelengths of 380 nm to 780 nm emitted from a standard light source D65 being incident on the surface of the optical laminate at an incident angle of 5°. As the color, the a* value and the b* value in the CIE-Lab color system were calculated. The results are shown in Table 1. In addition, for Example 1 to Example 3, Comparative Example 1 to Comparative Example 3, they are also shown in Figure 4 and Figure 3 .

[0172] In addition, for each test body of the optical laminate, the color of the reflected light was calculated in the same manner as when the above light was incident on the surface of the optical laminate at an incident angle of 5°, with the light being incident at incident angles of 10°, 20°, 25°, 30°, 40°, 50°, respectively. The results are shown in Table 1. In addition, for Example 1 to Example 3, Comparative Example 1 to Comparative Example 3, they are also shown in Figure 4 and Figure 3 .

[0173] Figure 4 is a graph showing the color of the reflected light when the light was incident on the surface of the optical laminate of Example 1 to Example 3, Comparative Example 1 to Comparative Example 3 at incident angles of 5°, 10°, 20°, 30°, 40°, 50°. Figure 3 is a graph showing the center part of the graph of Figure 4 . Figure 5 In , the numbers written near the points on the coordinates are the incident angles (°) corresponding to the points on the coordinates.

[0174] In addition, for the optical laminate of Example 1 to Example 3, Comparative Example 1 to Comparative Example 5, the absolute values of the differences between the maximum value and the minimum value of |a ＊ | / |b ＊ | at incident angles of 5°, 10°, 20°, 25°, 30°, and the absolute values of the differences between the maximum value and the minimum value of |a ＊ | / |b ＊ | at incident angles of 5°, 10°, 20°, 25°, 30°, 40° were calculated, respectively. The results are shown in Table 1. ＊ ＊

[0175] ​In addition, it was confirmed whether or not the reflected light at the time of incidence at an incidence angle of 5° to 25° changed in the a ＊ value and the b ＊ value in the CIE-Lab color system changed to other quadrants, in other words, whether or not it remained within the same quadrant, and evaluation was performed in accordance with the following criteria. The case of "O" indicates that the hue changed little, and the case of "X" indicates that the hue changed greatly in comparison thereto.

[0176] "Criteria"

[0177] O: Remained within the same quadrant.

[0178] X: Did not remain within the same quadrant.

[0179] "Evaluation of the hue of the reflected light"

[0180] For the test pieces of the optical laminate of Example 1, Comparative Example 2, and Comparative Example 3 used in the measurement of the color of the reflected light, the color of each test piece was photographed when the surface of the optical laminate was irradiated with the above light at an incidence angle of 5°, 10°, 20°, 30°, and 40°.

[0181] Figure 3 is a photograph of each test piece when the surface of the optical laminate of Example 1, Comparative Example 2, and Comparative Example 3 was irradiated with light at an incidence angle of 5°, 10°, 20°, 30°, and 40°.

[0182] In addition, for the test pieces of the optical laminate of Example 1 to Example 3 and Comparative Example 1 to Comparative Example 3 used in the measurement of the color of the reflected light, the angle of recognition was changed from the side of each optical laminate opposite the transparent substrate 2 and was recognized by visual observation, and evaluation was performed in accordance with the following criteria.

[0183] "Criteria"

[0184] O: The change in the hue (the tendency of the hue) could not be recognized.

[0185] X: The change in the hue (the tendency of the hue) could be certainly recognized.

[0186] "Measurement of the Martens hardness"

[0187] The Martens hardness at the time of indentation load of 0.1 mN was measured using a Vickers indenter manufactured by Fisher as PICODENTOR HM-500. Then, evaluation was performed in accordance with the following criteria.

[0188] "Criteria"

[0189] O: 1000 (N / mm 2 ) or more.

[0190] X: Less than 1000 (N / mm 2 ).

[0191] "Steel wool sliding property test"

[0192] Using a friction tester I according to JIS L0849, a friction body was moved horizontally to and fro along the surface of the optical laminate (test piece) of Example 1, Comparative Example 2, and the test piece was obtained.

[0193] As the friction body, steel wool (#0000 manufactured by Bonsai Co., Ltd.) was used. The test was set to a load of 1000 g / cm 2 , a stroke of 75 mm, and a speed of 150 mm / s, and whether or not damage was caused when the test steel wool (SW) was moved to and fro 10 times was examined. Then, evaluation was performed according to the following criteria.

[0194] O: a case where no damage was caused.

[0195] X: a case where damage was caused.

[0196] As shown in Table 1, Figure 4 and Figure 3 the optical laminates of Example 1 to Example 3 satisfying the above (Condition A) to (Condition D) had a small change in the hue of reflected light when light was incident at an incident angle of 5° to 40°. In addition, according to Table 1, Figure 4 and Figure 3 it was confirmed that the optical laminates of Example 1 to Example 3 had reflected light having similar hues when light at an incident angle of 5° to 40° was continuously incident, and showed a tendency that the chroma decreased as the incident angle increased. In addition, as shown in Table 1, the optical laminates of Example 1 to Example 3 had a result of "O" in the visual evaluation.

[0197] Further, Example 1 to 3 satisfied (Condition E) in addition to (Condition A) to (Condition D). That is, in Example 1 to 3, the reflected light at an incident angle of 5° to 25° did not change to other quadrants but remained within the same quadrant in terms of the a ＊ value and the b ＊ value in the CIE-Lab color system. This indicates that in a case where a display device provided with the optical laminate of Example 1 to 3 is provided in a sub-instrument panel of an automobile or the like, or in a case where it is provided in a front headliner of a rear seat, the change in the color tone when recognized from the rear seat is small, and it is suitable for such use.

[0198] On the contrary, in the optical laminates of Comparative Example 1 to Comparative Example 3 not satisfying any one or more of the above (Condition A) to (Condition C), as shown in Table 1, Figure 4 and Figure 5As shown, compared with the optical laminates of Examples 1 to 3, the hue change of the reflected light is greater when incident light is incident at angles of 5° to 40°. Furthermore, as shown in Table 1, the visual evaluation results of the optical laminates of Comparative Examples 1 to 3 are “×”.

[0199] In addition, for Comparative Examples 2 and 5, condition E is not met. When the display device with the optical laminate of Comparative Examples 2 and 5 is installed in the sub-dashboard of a car or in the front roof of the rear seat, the color change when viewed from the rear seat is large. Compared with the optical laminate of Examples 1 to 3, it is not suitable for such applications.

[0200] like Figure 5 As shown, in the optical laminate of Example 1, although the blue hue can be identified when the recognition angle is changed from an incident angle of 5° to 20°, the chroma decreases as the incident angle increases. Moreover, in the optical laminate of Example 1, it becomes essentially colorless at incident angles of 30° and 40°.

[0201] In contrast, such as ​ As shown, in the optical laminate of Comparative Example 2, a purple hue can be discerned at incident angles of 5° and 10°, a yellowish-green hue can be discerned at incident angles of 20° and 30°, and a green hue can be discerned at an incident angle of 40°. That is, in the optical laminate of Comparative Example 2, the hues of the colors discerned at incident angles of 5° and 10° are different from those at incident angles of 20°, 30°, and 40°.

[0202] Furthermore, in the optical laminate of Comparative Example 3, a blue hue can be discerned at incident angles of 5° and 10°, a purple hue can be discerned at an incident angle of 20°, and a magenta hue can be discerned at incident angles of 30° and 40°. That is, in the optical laminate of Comparative Example 3, the hues of the colors discerned at incident angles of 5° and 10° are different from those at incident angles of 20° and 30° and 40°.

[0203] The results of the Martens hardness test show that, in Comparative Examples 4 and 5, which obtained optical laminates by coating to create an anti-reflective layer, the hardness was significantly reduced compared to Examples 1-3 and Comparative Examples 1-3, which obtained optical laminates by sputtering to create an anti-reflective layer and forming an anti-fouling layer thereon.

[0204] This is because: since inorganic thin films are formed by sputtering, a denser and harder film is formed compared to coating methods.

[0205] The results of the steel wool sliding performance test show that, compared with Examples 1-3 and Comparative Examples 1-3, the steel wool sliding performance of Comparative Examples 4 and 5 is reduced.

[0206] Symbol Explanation

[0207] 1: optical laminate; 2: transparent substrate; 3: hard coat layer; 4: anti-reflection layer; 4a, 4c: low refractive index material layer; 4b: high refractive index material layer; 5: anti-fouling layer.

Claims

1. An optical laminate, characterized by, a transparent substrate, a hard coat layer, and an antireflection layer are sequentially stacked, the antireflection layer is composed of a laminate of a low refractive index material layer and a high refractive index material layer, the high refractive index material layer is composed of a material having a higher refractive index than the low refractive index material layer, The reflected light from light with wavelengths of 380nm to 780nm emitted by a standard light source D65, as shown in the CIE-Lab colorimetric system, is a ＊ value and b ＊ If the value satisfies conditions A to C below, the anti-reflective layer is a sputtering layer. Condition A: the absolute values of the a value and the b value of the reflected light when the surface of the optical laminate is irradiated with the light at an incident angle of 30 to 40 degrees are each 3 or less ＊ ＊ or less​ Condition B: the a value and the b value of the reflected light when the surface of the optical laminate is irradiated with the light at an incident angle of 5°, 10°, 20°, or 30° satisfy the following formula (B1) ＊ ＊ (B1) 0.90 ≤ a / b ≤ 1.10​ {(|a ＊ | / |b ＊ |) - {(|a ＊ | / |b ＊ |) < 1.0... (Bl) Condition C: one or both of the a ＊ value and the b ＊ value of the reflected light when the surface of the optical laminate is irradiated with the light at an incident angle of 5° is 5 or more in absolute value. The a ＊ value and the b ＊ value is in a range of 15 or less in absolute value.

2. The optical laminate according to claim 1, characterized by the a value and the b value in the CIE-Lab color system of reflected light at the time of incidence of the light ＊ value and b ＊ value satisfy the following condition D, Condition D: the a value and the b value of the reflected light when the surface of the optical laminate is irradiated with the light at an incident angle of 5°, 10°, 20°, 30°, or 40° satisfy the following formula (D1) ＊ ＊ value of the reflected light when the surface of the optical laminate is irradiated with the light at an incident angle of 5°, 10°, 20°, 30°, or 40° satisfy the following formula (D1)​ {(|a ＊ | / |b ＊ |) - {(|a ＊ | / |b ＊ |) < 1.5... (D1).

3. The optical laminate according to claim 2, in the condition D, the a value and the b value of the reflected light when the surface of the optical laminate is irradiated with the light at an incident angle of 5°, 10°, 20°, 30°, 40° satisfy the following formula (D2), ＊ ＊ (D2) 0.95 < a < 1.05, 0.95 < b < 1.05.​ {(|a ＊ | / |b ＊ |) of the maximum value of {(|a ＊ | / |b ＊ |) of the minimum value of {(|a (D2).

4. The optical laminate according to claim 2, in the condition D, the a value and the b value of the reflected light when the surface of the optical laminate is irradiated with the light at an incident angle of 5°, 10°, 20°, 30°, 40° satisfy the following formula (D3), ＊ ＊ (D3) 0.95 < a < 1.05, 0.95 < b < 1.05.​ {(|a ＊ | / |b ＊ |) of the maximum value of {(|a ＊ | / |b ＊ |) of the minimum value of {(|a (D3).

5. The optical laminate according to any one of claims 1 to 4, the low refractive index material layer contains Si oxide, and the high refractive index material layer is composed of Nb2O5.

6. The optical laminate according to claim 5, the low refractive index material layer and the high refractive index material layer are sputtered layers.

7. The optical laminate according to any one of claims 1 to 4, an antifouling layer is stacked on a surface of the antireflection layer opposite to the hard coat layer.

8. The optical laminate according to claim 7, the antifouling layer is an evaporation film or a coating film containing a fluorine-based compound.

9. An article provided with an optical laminate, characterized by comprising: The optical laminate is the optical laminate according to any one of claims 1 to 8.

10. The article provided with an optical laminate according to claim 9, the optical laminate is provided on a surface of an image display device.

Images