JP6981194B2 - A method for manufacturing a color-developing structure, a display body, a color-developing sheet, a molded body, and a color-developing structure. - Google Patents

Description

The present invention relates to a color-developing structure exhibiting a structural color, a display body and a color-developing sheet including the color-developing structure, a molded body including the color-developing sheet, and a method for manufacturing the color-developing structure.

Structural colors that are often observed as the colors of natural organisms such as morpho butterflies are different from the colors that are visually recognized due to electron transitions in molecules, such as the colors exhibited by dyes, such as light diffraction, interference, and scattering. It is a color that is visually recognized by the action of an optical phenomenon caused by the fine structure of an object.

For example, the structural color due to multi-layer film interference is a structural color caused by the interference of light reflected at each interface of the multi-layer film in the multi-layer film layers having different refractive indices of adjacent thin films, and the multi-layer film interference is , Is one of the coloring principles of the wing of the morpho butterfly. In the wing of the morpho butterfly, in addition to the multi-layer film interference, the fine uneven structure of the wing surface causes light scattering and diffraction, and as a result, a bright blue color is visually recognized at a wide observation angle.

As described in Patent Document 1, as a structure that artificially reproduces a structural color such as the wing of a morpho butterfly, a multilayer film layer is laminated on the surface of a base material having fine irregularities arranged unevenly. Structure has been proposed.

In the multilayer film layer, the wavelength of light enhanced by interference varies depending on the optical path difference generated in each layer of the multilayer film layer, and the optical path difference is determined by the film thickness and the refractive index of each layer. Then, the emission direction of the light enhanced by the interference is limited to a specific direction depending on the incident angle of the incident light. Therefore, in the structure in which the multilayer film layer is laminated on the plane, the wavelength of the reflected light to be visually recognized changes greatly depending on the observation angle, so that the color to be visually recognized changes greatly depending on the observation angle.

On the other hand, in the structure of Patent Document 1, since the multilayer film layer is laminated on the irregular unevenness, the reflected light enhanced by the interference spreads in multiple directions, so that the color changes depending on the observation angle. It becomes gradual. As a result, a structure that exhibits a specific color at a wide observation angle, such as the wing of a morpho butterfly, is realized.

Japanese Unexamined Patent Publication No. 2005-153192

By the way, in the structure described in Patent Document 1, the multilayer film layer has irregularities that follow the irregularities of the base material, and these irregularities constitute the surface of the structure. Therefore, when a physical impact or a chemical impact is applied to the structure from the outside, the uneven structure of the multilayer film layer may be deformed or deteriorated. In addition, the uneven structure may be clogged with dirt or foreign matter. When such a collapse of the uneven structure occurs, the optical path length of the light reflected by the multilayer film changes, and the effect of diffusing the reflected light in multiple directions is reduced, so that desired color development can be obtained in the structure. It becomes difficult.

An object of the present invention is to provide a color-developing structure, a display body, a color-developing sheet, a molded body, and a method for manufacturing a color-developing structure capable of protecting the uneven structure of the multilayer film layer.

The color-developing structure that solves the above-mentioned problems is a concavo-convex layer having a concavo-convex structure on the surface and a multilayer film layer having a surface shape that is located on the concavo-convex structure and follows the concavo-convex structure. The multilayers that are adjacent to each other have different refractive optics, and the reflectance of the incident light incident on the multilayer film layer in a specific wavelength range is higher than the reflectance of light in other wavelength ranges. A first optical functional layer including a film layer, wherein the outermost layer of the optical functional layer opposite to the uneven layer is the optical functional layer having a protective function lower than the outermost layer. The direction and the second direction orthogonal to the first direction are directions included in a virtual plane which is a virtual plane on which the uneven structure is projected in the thickness direction of the uneven layer, and the uneven structure is formed. The constituent convex portions have a shape of one or more steps, and the pattern formed by the projected image of the convex portions in the virtual plane has a length along the second direction equal to or longer than the length along the first direction. Including a pattern consisting of a set of a plurality of graphic elements, the length of the graphic element along the first direction is equal to or less than a sub-wavelength, and the length of the plurality of graphic elements along the second direction. The standard deviation of is larger than the standard deviation of the length along the first direction.

According to the above configuration, since the lower layer is protected by the outermost layer of the optical functional layer, the uneven structure of the multilayer film layer can be protected.
In the color-developing structure, the uneven layer has light transmission to the incident light, and the protective layer covering the surface of the multilayer film layer as the outermost layer transmits the multilayer film layer of the incident light. It may have a light absorption property that absorbs at least a part of light.

According to the above configuration, when the color-developing structure is observed from the side where the concavo-convex layer is located, at least a part of the light transmitted through the multilayer film layer from the concavo-convex layer side is absorbed by the protective layer, and the transmitted light is absorbed by the concavo-convex layer side. It is suppressed that it returns to. Therefore, since the light in the wavelength range different from the light reflected from the multilayer film layer is suppressed from being visually recognized, it is possible to suppress the deterioration of the color visibility due to the reflected light.

In the color-developing structure, the protective layer may contain a black pigment.
According to the above configuration, since the protective layer can absorb light in a wide wavelength range in the visible region, in a configuration in which the incident light is light in the visible region, the wavelength range of transmitted light according to the configuration of the multilayer film layer A protective layer that suitably absorbs transmitted light can be realized regardless of the difference.
The color-developing structure may further include an antireflection layer that covers a surface of the uneven layer opposite to the optical functional layer.
According to the above configuration, when the color-developing structure is observed from the side where the uneven layer is located, the surface reflection of the uneven layer is reduced, so that the visibility of the color due to the reflected light from the multilayer film layer may be lowered. It can be suppressed.

The color-developing structure may further include an adhesive layer that covers a surface of the optical functional layer opposite to the uneven layer.
According to the above configuration, the color-developing structure can be suitably attached to the adherend for decoration or the like. Then, a structure suitable for the purpose of observing the color-developing structure from the side where the uneven layer is located is realized.
In the color-developing structure, the layer constituting the color-developing structure may include a layer containing an ultraviolet absorber.
According to the above configuration, it is possible to prevent the material constituting the color-developing structure from being deteriorated by ultraviolet rays.

In the color-developing structure, the protective layer covering the surface of the multilayer film layer as the outermost layer may be composed of two or more layers.
According to the above configuration, it is possible to increase the number of functions of the protective layer and enhance the functions of the protective layer by combining the functions of the layers constituting the protective layer.
In the color-developing structure, the hardness measured from the outermost surface of the color-developing structure may be 0.03 GPa or more.
According to the above configuration, the scratch resistance of the color-developing structure is enhanced.
In the color-developing structure, the arithmetic mean roughness on the outermost surface of the color-developing structure may be 2 μm or less.

According to the above configuration, since diffused reflection of light on the outermost surface of the color-developing structure can be suppressed, it is possible to suppress deterioration of color visibility due to reflected light from the multilayer film layer.
In the color-developing structure, the water contact angle on the outermost surface of the color-developing structure may be 60 degrees or more.
According to the above configuration, deterioration of the color-developing structure due to the adhesion of water to the outermost surface can be suppressed.

In the color-developing structure, the uneven layer is composed of a base material and a resin layer covering the surface of the base material, and the uneven structure is located on a surface of the resin layer opposite to the base material. May be good.
According to the above configuration, the degree of freedom in selecting the material of the base material is increased as compared with the configuration in which the uneven structure is formed on the base material, and it is suitable for forming the uneven structure and forming fine unevenness. The nanoimprint method can be applied.

In the color-developing structure, the pattern formed by the projected image of the convex portion on the virtual plane is a pattern composed of a set of the plurality of graphic elements, and the height of the convex portion constituting the concave-convex structure is constant. There may be.
According to the above configuration, the effect of diffusing the reflected light is obtained by the convex portions constituting the concave-convex structure, and the light in a specific wavelength range is observed at a wide angle as the reflected light from the multilayer film layer.

In the color-developing structure, the pattern formed by the projected image of the convex portion on the virtual plane extends along the second direction with the first pattern composed of a set of the plurality of graphic elements, and extends in the first direction. It is a pattern in which a second pattern consisting of a plurality of strip-shaped regions arranged along the pattern is superimposed, and the arrangement interval of the strip-shaped regions along the first direction is not constant in the plurality of strip-shaped regions, and the average value thereof is not constant. The convex portion, which is ½ or more of the minimum wavelength in the wavelength range included in the incident light and constitutes the concave-convex structure, is a predetermined element in which the projected image on the virtual plane constitutes the first pattern. It has a multi-stage shape in which a convex element having a height and a convex element having a predetermined height, which is an element whose projected image on the virtual plane constitutes the second pattern, are overlapped in the height direction. You may.

According to the above configuration, the convex portion provides a diffusion effect and a diffraction effect of the reflected light, and the light in a specific wavelength range can be observed as the reflected light from the multilayer film layer 16 at a wide observation angle, and the reflection thereof. By increasing the intensity of light, bright and glossy colors are visually recognized.

In the color-developing structure, in the second pattern, the plurality of strip-shaped regions are arranged along each of the first direction and the second direction, and at least the average value and standard deviation of the arrangement spacing of the strip-shaped regions. On the other hand, the arrangement interval along the first direction and the arrangement interval along the second direction may be different.

According to the above configuration, the convex element constituting the second pattern depends on the difference between the influence of the light scattering effect by the convex element constituting the first pattern on the first direction and the influence on the second direction. The light diffraction effect due to can be adjusted.

In the color-developing structure, in the second pattern, the plurality of strip-shaped regions are arranged along the first direction and the second direction, respectively, and in the plurality of strip-shaped regions, along the first direction. Each of the average value of the arrangement spacing of the strip-shaped region and the average value of the arrangement spacing of the strip-shaped region along the second direction may be 1 μm or more and 100 μm or less.

According to the above configuration, the convex element constituting the second pattern depends on the difference between the influence of the light scattering effect by the convex element constituting the first pattern on the first direction and the influence on the second direction. It is possible to adjust the diffraction effect of the light due to the above, and the diffraction effect of the reflected light can be adjusted within the range in which the diffraction effect of the reflected light is preferably exhibited.
The display body that solves the above-mentioned problems is a display body that includes a plurality of display elements and has a front surface and a back surface, and the display elements are composed of the color-developing structure.
According to the above configuration, a display body in which the uneven structure of the multilayer film layer is protected is realized, and it is easy to preferably obtain a desired color on the display body.

In the display body, the plurality of display elements include a first display element and a second display element, and the display body is the first display element when viewed from a direction facing the surface of the display body. The material and film thickness of each layer including the first display area in which the first display element is located and the second display area in which the second display element is located, and the material and film thickness of each layer constituting the multilayer film layer are the first display element and the second display. The height of the convex portion in the concave-convex layer included in the first display element and the height of the convex portion in the concave-convex layer included in the second display element may be different from each other.

According to the above configuration, the first display element and the second display element exhibit different hue colors, and the first display area and the second display area are visually recognized as having different hue colors. Since the configurations of the multilayer film layers are the same in the first display element and the second display element, it is not necessary to form the multilayer film layer for each display region, and the display regions have different hues from each other. The display body can be formed by a simple manufacturing process.

The color-developing sheet that solves the above-mentioned problems is a color-developing sheet composed of the above-mentioned color-developing structure.
According to the above configuration, a color-developing sheet in which the uneven structure of the multilayer film layer is protected is realized, and it is easy to preferably obtain a desired color on the color-developing sheet.
In the color-developing sheet, the protective layer covering the surface of the multilayer film layer as the outermost layer of the optical functional layer may have thermoplasticity.
According to the above configuration, when the color-developing sheet is fixed to the surface of the adherend by using the laminating decoration method, the ability of the protective layer to follow the uneven structure of the multilayer film layer is preferably obtained. Therefore, a configuration suitable for a color-developing sheet fixed to the surface of the adherend by using the laminating decoration method is realized.

In the color-developing sheet, the adhesive layer may have a heat-sealing property.
According to the above configuration, when the coloring sheet is fixed to the surface of the adherend by using the laminating decoration method, the adhesive layer is brought into contact with the adherend to integrate the coloring sheet and the adherend. Therefore, the color-developing sheet and the adherend are preferably adhered to each other. Therefore, a configuration suitable for a color-developing sheet fixed to the surface of the adherend by using the laminating decoration method is realized.

The molded body that solves the above problems includes the color-developing sheet and an adherend to which the color-developing sheet is fixed.
According to the above configuration, since the molded product includes a color-developing sheet in which the uneven structure of the multilayer film layer is protected, it is easy to preferably obtain a desired color on the color-developing sheet, and the decorativeness of the molded product is enhanced.
In the molded body, the adherend may be located on the side where the protective layer is located with respect to the uneven layer.

According to the above configuration, the color-developing sheet is observed from the side where the uneven layer is located, and at least a part of the light transmitted through the multilayer film layer is absorbed by the protective layer, so that the desired color development can be preferably obtained in the color-developing sheet. Cheap. That is, since the color-developing sheet is used in such a manner that the color-developing property can be suitably exhibited, the decorativeness of the molded product is enhanced.

The method for manufacturing a color-developing structure that solves the above problems includes a step of forming an uneven layer having an uneven structure on the surface by transferring the unevenness of the concave plate to a resin by using a nanoimprint method, and a method of forming the uneven layer on the uneven structure. The optical functional layers including the multilayer film layer have different refractive coefficients from each other in the layers adjacent to each other in the multilayer film layer, and the reflectance of the incident light incident on the multilayer film layer in a specific wavelength range is high. A step of forming the outermost layer of the optical functional layer opposite to the uneven layer so as to have a protective function of a lower layer than the outermost layer while having a higher light reflectance in other wavelength regions. , And the second direction orthogonal to the first direction is a direction included in a virtual plane which is a virtual surface on which the uneven structure is projected in the thickness direction of the uneven layer. In the step of forming the concavo-convex layer, the pattern formed by the projection image of one or more convex portions constituting the concavo-convex structure in the virtual plane has a length along the second direction in the first direction. The concave-convex structure is formed so as to include a pattern consisting of a set of a plurality of graphic elements having a length equal to or longer than that of the graphic element, and the length of the graphic element along the first direction is equal to or less than a sub-wavelength. In the graphic element of, the standard deviation of the length along the second direction is larger than the standard deviation of the length along the first direction.

According to the above manufacturing method, when the color-developing structure including the optical functional layer having a protective function is manufactured, the uneven structure of the uneven layer is formed by using the nanoimprint method, so that the fine uneven structure is suitable and convenient. Can be formed.
In the above-mentioned production method, the nanoimprint method may be an optical nanoimprint method or a thermal nanoimprint method.
According to the above manufacturing method, the formation of the uneven structure by the nanoimprint method is preferably and easily realized.

According to the present invention, it is possible to protect the uneven structure of the multilayer film layer included in the color-developing structure.

A cross-sectional view showing a cross-sectional structure of a color-developing structure having a first structure for one embodiment of the color-developing structure. Regarding one embodiment of the color-developing structure, (a) is a plan view showing a plan structure of a concavo-convex structure in a first structure, and (b) is a cross-sectional view showing a cross-sectional structure of a concavo-convex structure in a first structure. A cross-sectional view showing a cross-sectional structure of a color-developing structure having a second structure for one embodiment of the color-developing structure. Regarding one embodiment of the color-developing structure, (a) is a plan view showing a plan structure of a concavo-convex structure consisting of only a second convex element in the second structure, and (b) is a second convex in the second structure. The cross-sectional view which shows the cross-sectional structure of the concavo-convex structure consisting only of a part element. Regarding one embodiment of the color-developing structure, (a) is a plan view showing a plan structure of a concavo-convex structure in a second structure, and (b) is a cross-sectional view showing a cross-sectional structure of a concavo-convex structure in a second structure. A cross-sectional view showing a cross-sectional structure of a color-developing structure of a modified example for one embodiment of the color-developing structure. A plan view showing a planar structure of a display body according to an embodiment of the display body. A cross-sectional view showing a cross-sectional structure of a display body according to an embodiment of the display body. A cross-sectional view showing a cross-sectional structure of a color-developing sheet for one embodiment of the color-developing sheet. A cross-sectional view showing a cross-sectional structure of a molded product according to an embodiment of the molded product.

With reference to FIGS. 1 to 10, embodiments of a color-developing structure, a display body, a color-developing sheet, a molded body, and a method for manufacturing the color-developing structure will be described.

[Coloring structure]
The color-developing structure of the present embodiment includes a concavo-convex structure having a multi-layered film layer and a protective layer covering the surface of the multi-layered film layer in the concavo-convex structure. As the uneven structure of the concave-convex structure, both the first structure and the second structure can be applied, and first, each of these two structures will be described.

The wavelength range of the incident light and the reflected light with respect to the color-developing structure is not particularly limited, but in the following description, the color-developing structure for light in the visible region will be described as an example. In the present embodiment, light in the wavelength range of 360 nm or more and 830 nm or less is defined as light in the visible region.

<First structure>
FIG. 1 shows a color-developing structure 30 including a concavo-convex structure 10 having a first structure and a protective layer 20.
The concavo-convex structure 10 is formed of a material that transmits light in the visible region, and is an example of a concavo-convex layer having a concavo-convex structure on its surface, a base material 15 and a multilayer film layer 16 laminated on the surface of the base material 15. And have. That is, the multilayer film layer 16 covers the surface of the base material 15 on which the unevenness is formed. The uneven structure of the base material 15 is composed of a plurality of convex portions 15a and concave portions 15b which are regions between the plurality of convex portions 15a, and the convex portions 15a have an irregular length and are substantially strip-shaped. It consists of a part that extends to.

The multilayer film layer 16 has a structure in which high refractive index layers 16a and low refractive index layers 16b are alternately laminated. The refractive index of the high refractive index layer 16a is larger than that of the low refractive index layer 16b. For example, the high-refractive index layer 16a is in contact with the surface of the base material 15, and the low-refractive index layer 16b constitutes the surface of the multilayer film layer 16 opposite to the base material 15.

The structure of the multilayer film layer 16 is the same on the convex portion 15a and the concave portion 15b of the base material 15, that is, the material, the film thickness, and the stacking order of each layer constituting the multilayer film layer 16 are the same. The surface of the multilayer film layer 16 opposite to the base material 15 has a surface shape that follows the uneven structure of the base material 15, that is, an arrangement that corresponds to the arrangement of the unevenness formed on the base material 15. It has irregularities. The protective layer 20 covers the surface of the multilayer film layer 16. The optical functional layer is composed of the protective layer 20 and the multilayer film layer 16.

In such a structure, when light is incident on the color-developing structure 30 from the side where the protective layer 20 is located, the light reflected at each interface between the high refractive index layer 16a and the low refractive index layer 16b in the multilayer film layer 16 interferes. As a result of raising and changing the traveling direction due to irregular irregularities on the surface of the multilayer film layer 16, light in a specific wavelength range is emitted at a wide angle. The specific wavelength range strongly emitted as this reflected light is determined by the material and film thickness of the high refractive index layer 16a and the low refractive index layer 16b, and the width, height and arrangement of the convex portions 15a.

Since the surface of the multilayer film layer 16 is covered with the protective layer 20, the uneven structure of the multilayer film layer 16 may be deformed, specifically, the uneven structure may be deformed or the uneven structure may be clogged with dirt or foreign matter. It can be suppressed.

Since the surface of the multilayer film layer 16 in contact with the base material 15 also has the same unevenness as the surface of the multilayer film layer 16, even when light is incident on the color-developing structure 30 from the side where the base material 15 is located. Similarly, reflected light in a specific wavelength range is emitted at a wide angle. That is, the color-developing structure 30 may be observed from either side of the protective layer 20 and the base material 15.

With reference to FIG. 2, the details of the uneven structure of the base material 15 which is the uneven layer will be described. FIG. 2A is a plan view of the base material 15 as viewed from a direction facing the surface thereof, and FIG. 2B is a cross section of the base material 15 along line 2-2 of FIG. 2A. It is sectional drawing which shows the structure. In FIG. 2A, dots are added to the convex portions 15a constituting the concave-convex structure.

As shown in FIG. 2A, the first direction Dx and the second direction Dy are directions included in a virtual plane which is a virtual surface on which the uneven structure is projected in the thickness direction of the base material 15. , The first direction Dx and the second direction Dy are orthogonal to each other. The virtual plane is a surface along the spreading direction of the base material 15 and is a plane orthogonal to the thickness direction of the base material 15.

In the virtual plane, the pattern formed by the projected image of the convex portion 15a is a pattern composed of a set of a plurality of rectangles R indicated by broken lines. The rectangle R is an example of a graphic element. The rectangle R has a shape extending in the second direction Dy, and in the rectangle R, the length d2 of the second direction Dy has a size equal to or larger than the length d1 of the first direction Dx. The plurality of rectangles R are arranged so as not to overlap in either the first direction Dx and the second direction Dy.

In the plurality of rectangles R, the length d1 of the first direction Dx is constant, and the plurality of rectangles R are arranged in the first direction Dx at the arrangement interval of the length d1, that is, the period of the length d1. ..

On the other hand, in the plurality of rectangles R, the length d2 in the second direction Dy is irregular, and the length d2 in each rectangle R is a value selected from the population having a predetermined standard deviation. This population preferably follows a normal distribution. In the pattern consisting of a plurality of rectangles R, for example, a plurality of rectangles R having a length d2 distributed with a predetermined standard deviation are tentatively spread in a predetermined area, and the presence or absence of the actual arrangement of each rectangle R is determined according to a certain probability. By determining, it is formed by setting the area where the rectangle R is arranged and the area where the rectangle R is not arranged. In order to efficiently scatter the reflected light from the multilayer film layer 16, it is preferable that the length d2 has a distribution having an average value of 4.15 μm or less and a standard deviation of 1 μm or less.

The area where the rectangle R is arranged is the area where the convex portion 15a is arranged, and when the adjacent rectangles R are in contact with each other, the area where the rectangle R is arranged is combined into one area of 1. Two convex portions 15a are arranged. In such a configuration, the length of the convex portion 15a in the first direction Dx is an integral multiple of the length d1 of the rectangle R.

In order to suppress the occurrence of iridescent spectroscopy due to the unevenness, the length d1 of the first direction Dx in the rectangle R is set to be equal to or less than the wavelength of light in the visible region. In other words, the length d1 has a length of less than or equal to the sub-wavelength, that is, less than or equal to the wavelength range of the incident light. That is, the length d1 is preferably 830 nm or less, and more preferably 700 nm or less. Further, the length d1 is preferably smaller than the peak wavelength of the light in the specific wavelength range reflected from the multilayer film layer 16. For example, when the color-developing structure 30 develops a blue color, the length d1 is preferably about 300 nm, and when the color-developing structure 30 develops a green color, the length d1 is about 400 nm. Preferably, when the color-developing structure 30 develops a red color, the length d1 is preferably about 460 nm.

In order to increase the spread of the reflected light from the multilayer film layer 16, that is, to enhance the scattering effect of the reflected light, it is preferable that the uneven structure has a lot of undulations, and it is viewed from the direction facing the surface of the base material 15. The ratio of the area occupied by the convex portion 15a per unit area is preferably 40% or more and 60% or less. For example, when viewed from the direction facing the surface of the base material 15, the ratio of the area of the convex portion 15a to the area of the concave portion 15b per unit area is preferably 1: 1.

As shown in FIG. 2B, the height h1 of the convex portion 15a is constant, and the desired color to be developed by the coloring structure 30, that is, the wavelength range desired to be reflected from the coloring structure 30. It may be set accordingly. If the height h1 of the convex portion 15a is larger than the surface roughness of the multilayer film layer 16 on the convex portion 15a or the concave portion 15b, the scattering effect of the reflected light can be obtained.

However, in order to suppress light interference caused by reflection on the surface unevenness of the multilayer film layer 16, the height h1 is preferably 1/2 or less of the wavelength of light in the visible region, that is, at 415 nm or less. It is preferable to have. Further, in order to suppress the interference of the light, the height h1 is more preferably 1/2 or less of the peak wavelength of the light in the specific wavelength range reflected from the multilayer film layer 16.

Further, if the height h1 is excessively large, the scattering effect of the reflected light becomes too high and the intensity of the reflected light tends to be low. Therefore, when the reflected light is light in the visible region, the height h1 is 10 nm or more and 200 nm. The following is preferable. For example, in the color-developing structure 30 exhibiting blue color, the height h1 is preferably about 40 nm or more and 150 nm or less in order to obtain an effective spread of light, and in order to suppress the scattering effect from becoming too high. The height h1 is preferably 100 nm or less.

The rectangles R may form a pattern of the convex portions 15a in the virtual plane by arranging the two rectangles R arranged along the first direction Dx so as to overlap each other. That is, the plurality of rectangles R may be arranged in the first direction Dx with an arrangement interval smaller than the length d1, and the arrangement intervals of the rectangles R may not be constant. In the portion where the rectangles R overlap, one convex portion 15a is located in one area where the areas where the rectangles R are arranged are combined. In this case, the length of the convex portion 15a in the first direction Dx is different from the integral multiple of the length d1 of the rectangle R. Further, the length d1 of the rectangle R does not have to be constant, and in each rectangle R, the length d2 is the length d1 or more, and the standard deviation of the length d2 in the plurality of rectangles R is the length d1. It should be larger than the standard deviation. Even with such a configuration, the scattering effect of the reflected light can be obtained.

<Second structure>
FIG. 3 shows a color-developing structure 31 including an uneven structure 11 having a second structure and a protective layer 20.
The concavo-convex structure 11 having the second structure has a concavo-convex structure on the base material 15, that is, a concavo-convex structure on the surface of the multilayer film layer 16, as compared with the concavo-convex structure 10 having the first structure. Differently, it has the same configuration as the concave-convex structure 10 having the first structure described above, except for the configuration of the concave-convex structure. In the following, the color-developing structure 31 will be described mainly on the differences from the color-developing structure 30 described above, and the same components as those of the color-developing structure 30 will be designated by the same reference numerals and the description thereof will be omitted.

The convex portion 15c constituting the concave-convex structure of the base material 15 in the concave-convex structure 11 includes a first convex portion element having the same structure as the convex portion 15a in the first structure and a second convex portion element extending in a band shape. , Has a structure superimposed in the thickness direction of the base material 15.

According to the color-developing structure 30 of the first structure, the change due to the observation angle of the visually recognized color becomes gradual due to the scattering effect of the reflected light, but it is visually recognized due to the decrease in the intensity of the reflected light due to the scattering. Color vividness is reduced. Depending on the application of the color-developing structure, a structure capable of observing more vivid colors from a wide observation angle may be required. In the second structure, the second convex element is arranged so that the incident light is strongly diffracted in a specific direction, and the light scattering effect by the first convex element and the light by the second convex element are arranged. Due to the diffraction effect, a color-developing structure 31 capable of observing more vivid colors at a wide observation angle is realized.

The configuration of the second convex portion element will be described with reference to FIG. 4. FIG. 4 (a) is a plan view of an uneven structure composed of only the second convex portion element, and FIG. 4 (b) is a cross-sectional view showing a cross-sectional structure along line 4-4 of FIG. 4 (a). be. In FIG. 4A, a dot is added to the second convex portion element.

As shown in FIG. 4A, in a plan view, that is, in the virtual plane, the second convex element 15Eb has a band shape extending with a constant width along the second direction Dy, and a plurality of second convex elements. The convex elements 15Eb are arranged at intervals along the first direction Dx. In other words, the pattern formed by the projected image of the second convex element 15Eb in the virtual plane is a pattern consisting of a plurality of band-shaped regions extending along the second direction Dy and lining up along the first direction Dx. The length d3 of the first direction Dx in the second convex portion element 15Eb may be the same as or different from the length d1 of the rectangle R that determines the pattern of the first convex portion element.

The arrangement spacing de of the second convex element 15Eb in the first direction Dx, that is, the arrangement spacing of the band-shaped region in the first direction Dx is at least one of the reflected light on the surface of the uneven structure formed by the second convex element 15Eb. The unit is set to be observed as primary diffracted light. The primary diffracted light is, in other words, diffracted light having a diffraction order m of 1 or -1. That is, when the incident angle of the incident light is θ, the reflection angle of the reflected light is φ, and the wavelength of the diffracted light is λ, the arrangement interval de satisfies de ≧ λ / (sinθ + sinφ). For example, when targeting visible light having λ = 360 nm, the arrangement spacing de of the second convex element 15Eb may be 180 nm or more, that is, the arrangement spacing de is the minimum wavelength in the wavelength range included in the incident light. It may be ½ or more of. The arrangement interval de is a distance along the first direction Dx between the ends of the two second convex element 15Eb adjacent to each other, and is the same as the second convex element 15Eb in the first direction Dx. The distance between the ends located on the side of.

The periodicity of the pattern formed by the second convex portion element 15Eb is reflected in the periodicity of the uneven structure of the base material 15, that is, the periodicity of the uneven structure on the surface of the multilayer film layer 16. When the arrangement spacing de of the plurality of second convex element 15Ebs is constant, the reflected light of a specific wavelength is emitted from the multilayer film layer 16 at a specific angle due to the diffraction phenomenon on the surface of the multilayer film layer 16. .. The light reflection intensity due to this diffraction is very strong as compared with the reflection intensity of the reflected light generated by the light scattering effect by the first convex element described in the first structure described above, so that it has a metallic luster. Light with brilliance is visually recognized, but on the other hand, spectroscopy occurs due to diffraction, and the visually recognized color changes according to a change in the observation angle.

Therefore, for example, even if the structure of the first convex portion element is designed so that the color-developing structure 31 exhibiting blue color is obtained, if the arrangement spacing de of the second convex portion element 15Eb is set to a constant value of about 400 nm to 5 μm. Depending on the observation angle, light due to strong green to red surface reflection due to diffraction is observed. On the other hand, for example, when the arrangement interval de of the second convex element 15Eb is increased to about 50 μm, the range of the angle at which the light in the visible region is diffracted becomes narrow, so that the color change due to the diffraction is difficult to visually recognize. However, light with a brilliance such as metallic luster is observed only at a specific viewing angle.

Therefore, if the arrangement interval de is not set to a constant value and the pattern of the second convex element 15Eb is a pattern in which a plurality of periodic structures having different periods are superimposed, light of a plurality of wavelengths is mixed with the reflected light due to diffraction. Because of the matching, it becomes difficult to visually recognize the dispersed light having high monochromaticity. Therefore, glossy and vivid colors are observed at a wide observation angle. In this case, the arrangement spacing de is selected from, for example, a range of 360 nm or more and 5 μm or less, and the average value of the arrangement spacing de of the plurality of second convex element 15Ebs is 1 / of the minimum wavelength in the wavelength range included in the incident light. It may be 2 or more.

However, as the standard deviation of the arrangement spacing de increases, the arrangement of the second convex element 15Eb becomes irregular and the scattering effect becomes dominant, making it difficult to obtain strong reflection due to diffraction. Therefore, the arrangement spacing de of the second convex element 15Eb is such that the reflected light due to diffraction is emitted in a range similar to the range in which the light spreads, depending on the angle at which the light spreads due to the light scattering effect of the first convex element. It is preferable to determine so as to be. For example, when the reflected light of blue is emitted in a range of ± 40 ° with respect to the incident angle, the array spacing de is set to an average value of 1 μm or more and 5 μm or less in the pattern of the second convex element 15Eb. The standard deviation is set to about 1 μm. As a result, the reflected light due to diffraction is generated at an angle similar to the angle at which the light spreads due to the light scattering effect of the first convex element.

That is, unlike the structure for diffracting and extracting light in a specific wavelength range, the structure composed of a plurality of second convex element elements 15Eb uses diffraction to obtain a predetermined angle range by dispersing the arrangement interval de. It is a structure for emitting light in various wavelength ranges.

Further, in order to cause a diffraction phenomenon having a longer period, a square region having a side of 10 μm or more and 100 μm or less is set as a unit region, and in the pattern of the second convex element 15Eb for each unit region, the array spacing de is set to the average value. The degree may be 1 μm or more and 5 μm or less, and the standard deviation may be about 1 μm. It should be noted that the plurality of unit regions may include regions in which the sequence spacing de is a constant value included in the range of 1 μm or more and 5 μm or less. Even if there is a unit region in which the sequence spacing de is constant, if the sequence spacing de has a variation of about 1 μm in the standard deviation in any of the unit regions adjacent to this unit region, the resolution of the human eye. In, the same effect as the configuration in which the arrangement spacing de varies in all unit regions can be expected.

The second convex element 15Eb shown in FIG. 4 has periodicity due to the arrangement interval de only in the first direction Dx. The light scattering effect of the first convex element mainly acts on the reflected light in the direction along the first direction Dx when viewed from the direction facing the surface of the base material 15, but the second direction Dy. It can also partially affect the reflected light in the direction along. Therefore, the second convex element 15Eb may also have periodicity in the second direction Dy. That is, the pattern of the second convex portion element 15Eb may be a pattern in which a plurality of strip-shaped regions extending in the second direction Dy are arranged along each of the first direction Dx and the second direction Dy.

In such a pattern of the second convex element 15Eb, for example, the average value of each of the arrangement interval along the first direction Dx and the arrangement interval along the second direction Dy of the band-shaped region is 1 μm or more and 100 μm or less. It suffices to have some variation. Further, depending on the difference between the influence of the light scattering effect by the first convex element on the first direction Dx and the influence on the second direction Dy, the average value of the array spacing along the first direction Dx and the first. The average value of the sequence spacing along the two-way Dy may be different from each other, and the standard deviation of the sequence spacing along the first direction Dx and the standard deviation of the sequence spacing along the second direction Dy are different from each other. May be.

As shown in FIG. 4B, the height h2 of the second convex portion element 15Eb may be larger than the surface roughness of the multilayer film layer 16 on the convex portion 15c and the concave portion 15b. However, as the height h2 becomes larger, the diffraction effect by the second convex portion element 15Eb becomes dominant in the effect of the uneven structure on the reflected light, and it becomes difficult to obtain the light scattering effect by the first convex portion element. The height h2 is preferably about the same as the height h1 of the first convex element, and the height h2 may be the same as the height h1. For example, the height h1 of the first convex portion element and the height h2 of the second convex portion element 15Eb are preferably included in the range of 10 nm or more and 200 nm or less, and in the color-developing structure 31 exhibiting a blue color, the first It is preferable that the height h1 of the 1-convex element and the height h2 of the 2nd convex element 15Eb are included in the range of 10 nm or more and 150 nm or less.

With reference to FIG. 5, the details of the concavo-convex structure of the concavo-convex structure 11 of the second structure will be described. 5 (a) is a plan view of the base material 15 as viewed from a direction facing the surface thereof, and FIG. 5 (b) is a cross section of the base material 15 along line 5-5 of FIG. 5 (a). It is sectional drawing which shows the structure. In FIG. 5A, dots having different densities are attached to the pattern formed by the first convex portion element and the pattern formed by the second convex portion element.

As shown in FIG. 5A, in the virtual plane, the patterns formed by the projected image of the convex portion 15c are the first pattern, which is the pattern formed by the projected image of the first convex portion element 15Ea, and the second pattern. It is a pattern in which the second pattern, which is a pattern formed by the projected image of the convex element 15Eb, is superimposed. That is, in the region where the convex portion 15c is located, a region S1 composed of only the first convex portion element 15Ea, a region S2 in which the first convex portion element 15Ea and the second convex portion element 15Eb overlap, and a second region. A region S3 composed of only the two convex element 15Eb is included. In FIG. 5, the first convex element 15Ea and the second convex element 15Eb are overlapped so that their ends are aligned in the first direction Dx, but the first convex element is not limited to such a configuration. The end portion of the portion element 15Ea and the end portion of the second convex portion element 15Eb may be separated from each other.

As shown in FIG. 5B, in the region S1, the height of the convex portion 15c is the height h1 of the first convex portion element 15Ea. Further, in the region S2, the height of the convex portion 15c is the sum of the height h1 of the first convex portion element 15Ea and the height h2 of the second convex portion element 15Eb. Further, in the region S3, the height of the convex portion 15c is the height h2 of the second convex portion element 15Eb. As described above, in the convex portion 15c, the projected image on the virtual plane constitutes the first pattern, the first convex portion element 15Ea having a predetermined height h1 and the projected image on the virtual plane form the second pattern. The second convex element 15Eb having a predetermined height h2 has a multi-stage shape overlapped in the height direction. The convex portion 15c can be regarded as a structure in which the second convex portion element 15Eb is superposed on the first convex portion element 15Ea, and the convex portion 15c has a structure in which the first convex portion element 15Ea is superposed on the second convex portion element 15Eb. It is also possible to capture.

In such a structure, the uneven structure on the surface of the multilayer film layer 16 is more complicated than that of the first structure, so that the uneven structure is easily deformed. Therefore, it is highly useful to protect the uneven structure of the multilayer film layer 16 by the protective layer 20.

As described above, according to the color-developing structure 31 having the second structure, the light diffusion phenomenon caused by the portion of the convex portion 15c formed by the first convex portion element 15Ea and the second convex portion element 15Eb are formed. Due to the synergistic effect with the diffraction phenomenon of light caused by the part where the light is diffracted, the reflected light in a specific wavelength range can be observed at a wide observation angle, and the intensity of this reflected light is increased to produce a glossy and vivid color. It is visually recognized. In other words, in the second structure, the convex portion 15c, which is one structure, has two functions of a light diffusing function and a light diffracting function.

In the virtual plane, the pattern formed by the first convex portion element 15Ea and the pattern formed by the second convex portion element 15Eb do not overlap the first convex portion element 15Ea and the second convex portion element 15Eb. May be placed in. Even with such a structure, the light diffusion effect of the first convex element 15Ea and the light diffraction effect of the second convex element 15Eb can be obtained. However, if the first convex element 15Ea and the second convex element 15Eb are arranged so as not to overlap each other, the first convex element 15Ea can be arranged per unit area as compared with the first structure. Area becomes smaller and the light diffusion effect is reduced. Therefore, in order to enhance the light diffusion effect and the diffraction effect of the convex element 15Ea and 15Eb, as shown in FIG. 5, the convex element 15Ea and the second convex element 15Eb are overlapped with each other. It is preferable that 15c has a multi-stage shape.

[Manufacturing method of colored structure]
The materials of the layers constituting the color-developing structures 30 and 31 and the method for manufacturing the color-developing structures 30 and 31 will be described.
The base material 15 is composed of a material having light transmission to light in the visible region, that is, a material transparent to light in the visible region. For example, as the base material 15, a synthetic quartz substrate or a film made of a resin such as polyethylene terephthalate (PET) is used. The uneven structure on the surface of the base material 15 is formed by using a known microfabrication technique such as lithography or dry etching for irradiating light or charged particle beams.

The uneven structure of the second structure is formed, for example, by sequentially performing etching using the resist pattern of the first pattern and etching using the resist pattern of the second pattern. At this time, either the etching of the first pattern or the etching of the second pattern may be performed first. That is, either the first convex portion element 15Ea or the second convex portion element 15Eb may be formed first.

The high-refractive index layer 16a and the low-refractive index layer 16b constituting the multilayer film layer 16 are composed of a material having light transmission to light in the visible region, that is, a material transparent to light in the visible region. To. As long as the refractive index of the high refractive index layer 16a is higher than the refractive index of the low refractive index layer 16b, the material of these layers is not limited, but the refraction of the high refractive index layer 16a and the low refractive index layer 16b. The larger the difference in rate, the higher the intensity of reflected light can be obtained with a smaller number of layers. From this point of view, for example, when the high refractive index layer 16a and the low refractive index layer 16b are made of an inorganic material, the high refractive index layer 16a is made of titanium dioxide (TiO ₂ ) and the low refractive index layer 16b is made of silicon dioxide. It is preferably composed of (SiO _2). Each of the high refractive index layer 16a and the low refractive index layer 16b made of such an inorganic material is formed by using a known thin film forming technique such as sputtering, vacuum deposition, or an atomic layer deposition method. Further, each of the high refractive index layer 16a and the low refractive index layer 16b may be made of an organic material, and in this case, self-assembly or the like is known for forming the high refractive index layer 16a and the low refractive index layer 16b. It suffices if the technique of is used.

The film thickness of each of the high-refractive index layer 16a and the low-refractive index layer 16b may be designed by using a transfer matrix method or the like according to the desired color to be developed by the color-developing structures 30 and 31. For example, when forming the blue-coloring structures 30 and 31, the thickness of the high-refractive index layer 16a made of _{TiO 2} is preferably about 40 nm, and the thickness of the low-refractive index layer 16b made of _{SiO 2 is preferable.} Is preferably about 75 nm.

In addition, in FIGS. 1 and 3, as the multilayer film layer 16, the multilayer film layer 16 is composed of 10 layers in which the high refractive index layer 16a and the low refractive index layer 16b are alternately laminated in this order from a position close to the base material 15. However, the number of layers and the order of stacking of the multilayer film layer 16 are not limited to this, and the high refractive index layer 16a and the low refractive index layer 16b are designed so that reflected light in a desired wavelength range can be obtained. You just have to. For example, the low refractive index layer 16b may be in contact with the surface of the base material 15, and the high refractive index layer 16a and the low refractive index layer 16b may be alternately laminated on the low refractive index layer 16b. Further, the layer constituting the outermost surface of the multilayer film layer 16 opposite to the base material 15 may be either the high refractive index layer 16a or the low refractive index layer 16b. Further, if the low refractive index layer 16b and the high refractive index layer 16a are alternately laminated, the material constituting the layer in contact with the surface of the base material 15 and the layer constituting the outermost surface is the same. May be good. Further, the multilayer film layer 16 may be composed of a combination of three or more layers having different refractive indexes.

In short, the multilayer film layer 16 has different refractive indexes of adjacent layers, and the reflectance of the incident light incident on the multilayer film layer 16 in a specific wavelength range is reflected in another wavelength range. It suffices if it is configured to be higher than the rate.

When the color-developing structures 30 and 31 are observed from the side where the protective layer 20 is located, the protective layer 20 is a material having light transmission to light in the visible region, that is, to light in the visible region. Consists of transparent material. As such a material, for example, polyesters such as acrylic, polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene and polyethylene, and resins such as polyvinyl chloride, polycarbonate, polyvinyl alcohol, polystyrene and polyamide are used.

Here, since the concave-convex structures 10 and 11 are formed of a material transparent to light in the visible region, a specific wavelength region reflected by the multilayer film layer 16 among the wavelength regions included in the incident light. A part of the light in the wavelength range other than the above passes through the multilayer film layer 16 and further, the uneven structures 10 and 11. Therefore, when observing the concavo-convex structures 10 and 11 from one side of the front and back surfaces, if there is a structure that repels transmitted light such as a light source or a white plate on the other side of the concavo-convex structures 10 and 11, the above one side Then, along with the reflected light in a specific wavelength range from the multilayer film layer 16, the transmitted light transmitted through the multilayer film layer 16 is visually recognized from the other side. As described above, the wavelength range of the transmitted light is different from the wavelength range of the reflected light, and the color of the transmitted light is mainly a complementary color of the color of the reflected light. Therefore, when such transmitted light is visually recognized, the visibility of the color due to the reflected light is lowered.

Therefore, it is preferable that the protective layer 20 is made of a material that absorbs the transmitted light transmitted through the multilayer film layer 16. In this case, the color-developing structures 30 and 31 are used in a manner observed from the side where the base material 15 is located. According to such a configuration, the light transmitted from the base material 15 side through the multilayer film layer 16 is absorbed by the protective layer 20, and the transmitted light is suppressed from returning to the base material 15 side, so that the color is developed from the base material 15 side. When the structures 30 and 31 are observed, it is possible to prevent the light in a wavelength range different from the light reflected from the multilayer film layer 16 from being visually recognized. Therefore, the deterioration of the visibility of the color due to the reflected light is suppressed, and the desired color development can be preferably obtained in the color development structures 30 and 31.

For example, the protective layer 20 may be a layer containing a material that absorbs light in the visible region, such as a light absorber or a black pigment. Specifically, the protective layer 20 is preferably a layer in which a black inorganic pigment such as carbon black, titanium black, black iron oxide, and a black composite oxide is mixed with the resin.

The protective layer 20 has such a light absorption property as long as it has a light absorption property that absorbs at least a part of the light transmitted through the multilayer film layer 16 without absorbing all the light in the visible region. Compared with the configuration in which the layer is not provided, the effect of suppressing the deterioration of the color visibility due to the reflected light can be obtained. Therefore, the protective layer 20 may be a layer containing a pigment having a color corresponding to the wavelength range of the light transmitted through the multilayer film layer 16. However, if the protective layer 20 is a black layer containing a black pigment, it is not necessary to adjust the color of the protective layer 20 according to the wavelength range of transmitted light, and the protective layer 20 emits light in a wide wavelength range. Since it is absorbed, the deterioration of color visibility due to reflected light can be easily and preferably suppressed.

Further, the protective layer 20 may contain an ultraviolet absorber. As the ultraviolet absorber, known ultraviolet absorbers such as benzophenone type, benzotriazole type, benzoate type, salicylate type, triazine type and cyanoacrylic rate type can be used.

If the protective layer 20 is configured to contain an ultraviolet absorber, the protective layer 20 absorbs ultraviolet rays when the color-developing structures 30 and 31 are used for long-term exposure to ultraviolet rays due to direct sunlight or the like. It is possible to prevent the materials constituting the color-developing structures 30 and 31 from being deteriorated by ultraviolet rays. Such an effect is used when the color-developing structures 30 and 31 are observed from the side where the protective layer 20 is located, that is, when incident light enters the color-developing structures 30 and 31 from the side where the protective layer 20 is located. In some cases, it is especially expensive.

The protective layer 20 is formed on the surface of the multilayer film layer 16 by using a known coating method such as an inkjet method, a spray method, a bar coating method, a roll coating method, a slit coating method, or a gravure coating method. The film thickness of the protective layer 20 is not particularly limited, but is preferably about 1 μm or more and 100 μm or less, for example.

If necessary, a solvent may be mixed with the ink which is the coating liquid for forming the protective layer 20. As the solvent, a solvent compatible with the resin constituting the protective layer 20 may be selected. For example, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether, toluene, xylene, methylcyclohexane, ethylcyclohexane, acetone, methyl ethyl ketone, etc. Examples thereof include methyl isobutyl ketone and diisobutyl ketone.

The protective layer 20 may be composed of a plurality of layers. For example, if the protective layer 20 includes a plurality of layers having different resistances to physical or chemical stimuli, the protective layer 20 having a plurality of resistances can be realized. Further, for example, if the protective layer 20 is configured to include a plurality of layers having similar resistance, the resistance common to the plurality of layers can be enhanced by the protective layer 20. Examples of such resistance include scratch resistance and water resistance.

[Characteristics of protective layer]
A preferable form of the characteristics of the protective layer 20 will be described. In the following form, the protective layer 20 is exposed to the outside air on the outermost surface of the color-developing structures 30 and 31, such as when the color-developing structures 30 and 31 are observed from the side where the protective layer 20 is located. It is particularly effective when used. In the following, the surface of the protective layer 20 is a surface opposite to the surface of the protective layer 20 in contact with the multilayer film layer 16, and is a surface constituting the outermost surfaces of the color-developing structures 30 and 31.

In the color-developing structures 30 and 31, the hardness measured from the surface of the protective layer 20 is preferably 0.03 GPa or more. This hardness is the indentation hardness, which is a hardness measured when the indentation depth is 100 nm by using the nanoindentation method. This hardness can be measured using, for example, a nano indenter manufactured by MTS. When the hardness is 0.03 GPa or more, the protective layer 20 is sufficiently hard, so that the scratch resistance of the color-developing structures 30 and 31 is enhanced.

In the color-developing structures 30 and 31, the surface roughness Ra on the surface of the protective layer 20 is preferably 2 μm or less. The surface roughness Ra is an arithmetic mean roughness and is calculated according to JIS B 0601: 2013. The surface roughness Ra can be measured using, for example, a non-contact type surface roughness meter (non-contact type surface / layer cross-section measurement system) manufactured by Ryoka System Co., Ltd. When the surface roughness Ra is 2 μm or less, the surface of the protective layer 20 is sufficiently smooth, so that diffuse reflection of light on the surface of the protective layer 20 can be suppressed. As a result, it is possible to suppress the deterioration of color visibility due to the reflected light from the multilayer film layer 16.

In the color-developing structures 30 and 31, the water contact angle on the surface of the protective layer 20 is preferably 60 degrees or more. This water contact angle is a contact angle measured 5 seconds after the water droplets have landed on the surface of the protective layer 20. The contact angle can be measured by a known procedure using a contact angle meter. When the water contact angle is 60 degrees or more, the affinity between the protective layer 20 and water is suppressed to a low level, so that when the color-developing structures 30 and 31 get wet, the protective layer 20 absorbs water. Deterioration is suppressed.

When the color-developing structures 30 and 31 are used in such a manner that the outermost surface of the outermost layer located on the opposite side of the protective layer 20 is exposed to the outside air, such as when the color-developing structures 30 and 31 are observed from the side where the base material 15 is located. The hardness is 0.03 GPa or more, the surface roughness Ra is 2 μm or less, and the surface roughness Ra is 2 μm or less on the outermost surface of the outermost layer, for example, the surface of the base material 15 opposite to the multilayer film layer 16. The water contact angle is preferably 60 degrees or more.

[Modification example of color development structure]
The color-developing structure may have the configuration shown in FIG. The concave-convex structure 12 included in the color-developing structure 32 shown in FIG. 6 includes a base material 15, a resin layer 17 covering the surface of the base material 15, and a multilayer film layer 16 laminated on the resin layer 17. The surface of the base material 15 is flat, and the resin layer 17 has irregularities on the surface. In the form shown in FIG. 6, the laminated body of the base material 15 and the resin layer 17 is an uneven layer. As the uneven structure on the surface of the resin layer 17, any of the above-mentioned uneven structure of the first structure and the uneven structure of the second structure can be applied.

As a method for forming the uneven structure of the resin layer 17, for example, a nanoimprint method is used. For example, when the uneven structure of the resin layer 17 is formed by the optical nanoimprint method, first, the resin constituting the resin layer 17 is formed on the surface of the mold, which is a concave plate having the inverted unevenness of the unevenness to be formed. As a result, a photocurable resin is applied. The coating method of the photocurable resin is not particularly limited, and known coating methods such as an inkjet method, a spray method, a bar coating method, a roll coating method, a slit coating method, and a gravure coating method may be used.

Next, the base material 15 is superposed on the surface of the coating layer made of a photocurable resin, and light is irradiated from the base material 15 side or the mold side in a state where the coating layer and the mold are pressed against each other. Subsequently, the mold is released from the cured photocurable resin and the base material 15. As a result, the unevenness of the mold is transferred to the photocurable resin, and the resin layer 17 having the unevenness on the surface is formed. The mold is composed of, for example, synthetic quartz or silicon, and is formed by using known microfabrication techniques such as lithography and dry etching for irradiating light or charged particle beams.
The photocurable resin may be applied to the surface of the base material 15 and irradiated with light in a state where the mold is pressed against the coating layer on the base material 15.

Further, the thermal nanoimprint method may be used instead of the optical nanoimprint method. In this case, as the resin of the resin layer 17, a resin corresponding to the production method such as a thermoplastic resin or a thermosetting resin is used. ..

[Application example of color development structure]
A specific application example of the above-mentioned color-developing structure will be described. Any of the color-developing structure 30 having the first structure, the color-developing structure 31 having the second structure, and the color-developing structure 32 described in the above-described modification can be applied to the application examples described below. Is.

<Display body>
The first application example of the color-developing structure is a form in which the color-developing structure is used as a display body. The display body may be used for the purpose of increasing the difficulty of forgery of the article, may be used for the purpose of enhancing the design of the article, or may be used for these purposes in combination. For the purpose of increasing the difficulty of forgery of goods, the display body is, for example, authentication documents such as passports and driver's licenses, securities such as gift certificates and checks, cards such as credit cards and cash cards, banknotes, etc. It will be pasted. Further, for the purpose of enhancing the design of the article, the display body is, for example, a decorative object to be worn, an article carried by a user, an article to be stationary such as furniture or a home appliance, a wall, a door, or the like. It can be attached to structures, interiors and exteriors of automobiles, etc.

As shown in FIG. 7, the display body 40 has a front surface 40F and a back surface 40R which is a surface opposite to the front surface 40F, and the display body 40 is the first display body 40 when viewed from a direction facing the front surface 40F. The display area 41A and the second display area 41B are included. The first display area 41A is an area in which a plurality of first pixels 42A are arranged, and the second display area 41B is an area in which a plurality of second pixels 42B are arranged. In other words, the first display area 41A is composed of a set of a plurality of first pixels 42A, and the second display area 41B is composed of a set of a plurality of second pixels 42B. A color-developing structure configuration is applied to each of the first pixel 42A and the second pixel 42B, and the first pixel 42A and the second pixel 42B exhibit colors having different hues from each other. That is, when viewed from the direction facing the surface 40F of the display body 40, colors having different hues are visually recognized in the first display area 41A and the second display area 41B.

Each of the first display area 41A and the second display area 41B expresses characters, symbols, figures, patterns, patterns, their backgrounds, etc. by these areas alone or by a combination of two or more of these areas. .. As an example, in the configuration shown in FIG. 7, a circular figure is represented by the first display area 41A, and a triangular figure is represented by the second display area 41B.

The display body 40 has a structure different from that of the color-developing structure around the display areas 41A and 41B, for example, a area having a structure in which a multilayer film layer is laminated on a base material having a flat surface. Alternatively, it may have a region having a structure in which a metal thin film is laminated on the base material.

FIG. 8 is a diagram showing a cross-sectional structure of the first pixel 42A and the second pixel 42B. FIG. 8 shows an example in which the color-developing structure 33 constituting these pixels 42A and 42B is a color-developing structure having a first structure.

The height h1 of the convex portion 15a is different between the first pixel 42A and the second pixel 42B. On the other hand, the configuration of the multilayer film layer 16 is common between the first pixel 42A and the second pixel 42B, that is, the material and film thickness of the high refractive index layer 16a, the material and film thickness of the low refractive index layer 16b, and so on. And, the number of layers of these layers is common. Since the height h1 of the convex portion 15a is different between the first pixel 42A and the second pixel 42B, the first pixel 42A and the second pixel 42B exhibit different hue colors. The height h1 of the convex portion 15a in each pixel 42A, 42B may be set according to the desired hue of each pixel 42A, 42B.

Here, the larger the difference between the height h1a of the convex portion 15a of the first pixel 42A and the height h1b of the convex portion 15a of the second pixel 42B, the larger the hue exhibited by the first pixel 42A and the presentness of the second pixel 42B. The difference from the hue becomes large, and the difference in hue becomes easily recognized by the human eye. For example, the difference between the height h1a and the height h1b is preferably 5 nm or more, and 1% or more of the peak wavelength of the reflected light from the multilayer film layer 16 when the multilayer film layer 16 is laminated on a flat surface. Is preferable.

For example, when the multilayer film layer 16 is laminated on a flat surface and the peak wavelength of the reflected light from the multilayer film layer 16 is 500 nm, and it is desired to develop a green color by the pixels, the height h1 of the convex portion 15a is set. It is preferably about 100 nm, and when it is desired to develop a red color depending on the pixel, the height h1 of the convex portion 15a is preferably about 200 nm.

In the above configuration, the height of the uneven structure on the surface of the multilayer film layer 16 is different between the first display region 41A and the second display region 41B, and the display body 40 is compared with the case where such height is constant. Since the uneven structure as a whole is complicated, the uneven structure is easily deformed. Therefore, it is highly useful to protect the uneven structure of the multilayer film layer 16 by the protective layer 20.

When the color-developing structure applied to the pixels 42A and 42B is a color-developing structure having a second structure, the first convex element 15Ea is formed in the pattern formed by the projected image of the convex portion 15c on the virtual plane. In a configuration in which the ratio occupied by the second convex element 15Eb is smaller than the ratio occupied by the second convex element 15Eb, the influence of the height h2 of the second convex element 15Eb on the hues of the pixels 42A and 42B is small. Therefore, even in the color-developing structure having the second structure, the hue exhibited by the pixels 42A and 42B can be adjusted by adjusting the height h1 of the first convex portion element 15Ea corresponding to the convex portion 15a of the first structure. Is.

The pattern of the convex portion 15a is set for each first pixel 42A and each second pixel 42B, for example. That is, the average value and standard deviation of the length d1 and the length d2 in the plurality of rectangles R constituting the pattern of the projected image of the convex portion 15a are set for each of the pixels 42A and 42B. The pattern of the convex portion 15a may be different for each of the pixels 42A and 42B, or may be the same. The size of the pixels 42A and 42B may be set according to the desired resolution of the image formed by the display areas 41A and 41B. In order to display a more accurate image, it is preferable that one side of the pixels 42A and 42B is 10 μm or more.

When manufacturing the pixels 42A and 42B, for example, after forming convex portions according to a pattern consisting of a plurality of rectangles R in a large area, the convex portions are cut so as to divide the pattern. The concave-convex structure of each pixel 42A and 42B may be formed by dividing the pixels by such means, and such a manufacturing method is preferable because the manufacturing process becomes easy. Here, due to the division of the convex portion, the length d2 of the second direction Dy is larger than the length d1 of the first direction Dx at the end of the pixels 42A and 42B in a part of the plurality of pixels 42A and 42B. Convex portions forming a small rectangle R may be formed. However, even if the pattern of the convex portion 15a includes such a rectangle R, if the ratio thereof is sufficiently small, the optical effect of the rectangle R is negligibly small.

As the protective layer 20, a protective layer 20 having absorption of transmitted light of the multilayer film layer 16 is used. Further, the color-developing structure 33 constituting the pixels 42A and 42B includes an antireflection layer 21. The antireflection layer 21 covers the surface of the base material 15 opposite to the multilayer film layer 16, that is, the surface of the uneven layer opposite to the multilayer film layer 16.

The pixels 42A and 42B are arranged so that the side of the antireflection layer 21 with respect to the protective layer 20 is the side of the front surface 40F with respect to the back surface 40R of the display body 40. That is, the protective layer 20 constitutes the back surface 40R of the display body 40, and the antireflection layer 21 constitutes the front surface 40F. Then, the display body 40 is observed from the surface 40F side, that is, the side where the antireflection layer 21 is located.

The antireflection layer 21 has a function of reducing surface reflection on the surface of the base material 15 opposite to the surface having irregularities. That is, the film thickness of the antireflection layer 21 is not less than the wavelength of light in the visible region, and the film thickness of the antireflection layer 21 is preferably 200 nm or less in order to enhance the function of suppressing surface reflection. Examples of the material constituting the antireflection layer 21 include magnesium fluoride (MgF ₂ ) and silicon dioxide (SiO ₂ ). In order to enhance the function of suppressing the surface reflection of the base material 15, the refractive index of the antireflection layer 21 is preferably equal to or lower than the refractive index of the base material 15. The antireflection layer 21 may be a layer made of a multilayer film in which high refractive index layers and low refractive index layers are alternately laminated.

When the display body 40 is observed from the surface 40F side, if the surface reflection of the base material 15 is large, the color visibility due to the reflected light in a specific wavelength range from the multilayer film layer 16 becomes low. On the other hand, since the surface reflection of the base material 15 is reduced by providing the antireflection layer 21, it is possible to suppress the deterioration of the color visibility due to the reflected light from the multilayer film layer 16 and display the display. The desired color development is suitably obtained in the body 40.
The base material 15 is continuous between the first pixel 42A and the second pixel 42B, that is, these pixels 42A and 42B have one common base material 15.

The uneven structure of the base material 15 is, for example, for each of the portion corresponding to the first display region 41A where the first pixel 42A is located and the portion corresponding to the second display region 41B where the second pixel 42B is located. , Formed by lithography and dry etching. In order to change the height h1 of the convex portion 15a, the etching time may be changed.

The multilayer film layer 16 is simultaneously formed by the same process with respect to the portion corresponding to the first display region 41A and the portion corresponding to the second display region 41B. Similarly, the protective layer 20 is formed simultaneously with respect to the portions corresponding to the respective display areas 41A and 41B, and the antireflection layer 21 is also formed at the same time. The antireflection layer 21 is formed, for example, by sputtering or vacuum vapor deposition before or after the formation of the multilayer film layer 16.

When the first display area 41A and the second display area 41B are in contact with each other, each of the multilayer film layer 16, the protective layer 20, and the antireflection layer 21 is located between the first pixel 42A and the second pixel 42B. It is continuous.

It should be noted that, in order to make the hues of the first pixel 42A and the second pixel 42B different from each other, the material, the film thickness, and the like of the layer constituting the multilayer film layer 16 are configured between the first pixel 42A and the second pixel 42B. It is also possible by making them different. However, if the configuration of the multilayer film layer 16 is different for each of the display regions 41A and 41B, masking of the region and film formation of the high refractive index layer 16a and the low refractive index layer 16b may be repeated for each of the display regions 41A and 41B. It is necessary and complicates the manufacturing process. As a result, manufacturing costs increase and yields decrease. Moreover, since it is difficult to mask a minute region, there is a limit to the formation of a fine image.

On the other hand, in the case of the configuration of the display body 40, it is possible to simultaneously form the multilayer film layer 16 on the portion corresponding to the first display region 41A and the portion corresponding to the second display region 41B. Therefore, the load required for manufacturing the display body 40 is reduced. Further, since it is easier to make the height h1 of the convex portion 15a different for each minute region as compared with masking to a minute region, the display regions 41A and 41B are made smaller to form a finer image. You can also do it.

In order to make the configuration of the multilayer film layer 16 the same for the first pixel 42A and the second pixel 42B and to change the hue h1 of the convex portion 15a, the multilayer film layer 16 is divided into the following. It is preferable to configure it as follows. That is, the peak wavelength of the reflected light from the multilayer film layer 16 when the multilayer film layer 16 is laminated on the flat surface is the wavelength of the hue of light developed by the first pixel 42A and the color developed by the second pixel 42B. It is preferable to configure the multilayer film layer 16 so as to be located between the wavelength of the light of the hue.

By changing the height h1 of the convex portion 15a, the shape of each layer constituting the multilayer film layer 16 may change to change the optical path length, or the wavelength range of light efficiently scattered by the uneven structure may change. It is considered that the hue visually recognized in the color-developing structure changes due to such a phenomenon.

Further, when the configuration of the color-developing structure 32, that is, the configuration in which the resin layer 17 laminated on the base material 15 has an uneven structure is applied to the configurations of the pixels 42A and 42B, the concave-convex structure is, for example, , Is formed as follows. That is, using the nanoimprint method, a mold in which the height of the unevenness is changed in the portion corresponding to each display area 41A and 41B is used, and the uneven structure of the resin layer 17 of each pixel 42A and 42B is formed at the same time.

Such a mold may be formed by performing lithography or dry etching for each portion corresponding to the display areas 41A and 41B. Further, for example, according to the following method, the mold can be formed more easily. That is, the dose of the charged particle beam irradiated to the resist used for the charged particle beam lithography is changed for each of the display areas 41A and 41B, and the development is performed so that unevenness of a desired height is formed in each of the display areas 41A and 41B. Adjust the time to form a resist pattern. A nickel mold is obtained by forming a metal layer such as nickel on the surface of the resist pattern by electroforming and then melting the resist.

The number of display areas included in the display body 40, that is, the number of display areas in which pixels composed of color-developing structures are arranged and exhibit colors having different hues from each other is not particularly limited, and the number of display areas is limited. It may be one or three or more. Further, the display area may include a display element composed of a color-developing structure, and the display element is not limited to a pixel, which is the minimum unit of repetition for forming a raster image, to form a vector image. It may be an area connecting the anchors of.

Further, as the configuration of the display element, any configuration can be applied as long as it is the configuration of the color-developing structure described above. For example, the protective layer 20 has the absorption of the transmitted light of the multilayer film layer 16. Instead, it may have only the function of protecting the uneven structure in the multilayer film layer 16, or may have the function of absorbing ultraviolet rays due to the inclusion of the ultraviolet absorber. In these cases, the protective layer 20 constitutes the front surface 40F of the display body 40, the antireflection layer 21 constitutes the back surface 40R, and the display body 40 is observed from the front surface 40F side, that is, the side where the protective layer 20 is located. Is preferable. Further, the antireflection layer 21 may not be provided.

<Coloring sheet and molded product>
The second application example of the color-developing structure is a form in which the color-developing structure is used as a color-developing sheet. The color-developing sheet is a sheet composed of a color-developing structure, and is fixed to an adherend for decoration or the like. A molded body is composed of a color-developing sheet and an adherend.

The shape and material of the adherend are not particularly limited, but for example, when the color-developing sheet is attached to the resin-made adherend, the color-developing sheet is, for example, a film insert method, an in-mold lamination method, or a three-dimensional overlay lamination method ( It is fixed to the surface of the adherend by using a laminating decoration method such as TOM).

The film insert method is a method of integrating an adherend and a color-developing sheet by performing injection molding in a state where a color-developing sheet formed by thermal vacuum forming is placed on a mold. The in-mold lamination method is a method in which the process from thermal vacuum forming of a color-developing sheet to the formation of an adherend by injection molding and integration with the color-developing sheet are all performed in the same mold. The three-dimensional overlay lamination method is a method of integrating the adherend and the color-developing sheet by utilizing the pressure difference in the airtight space vertically separated by the color-developing sheet.

In such a laminating decoration method, heat treatment, pressure treatment, and vacuum treatment are performed, so that the physical or chemical load on the color-developing structure is large. Therefore, it is highly beneficial that the protective layer 20 protects the uneven structure of the multilayer film layer 16.

As the color-developing structure constituting the color-developing sheet, any of the above-described color-developing structures can be applied. However, since the color-developing sheet is used so as to be arranged along the surface of the adherend, it is preferable that the color-developing structure has a property of easily deforming into a shape that follows the surface of the adherend. From this point of view, the structure of the color-developing structure 32, that is, the structure in which the resin layer 17 laminated on the base material 15 has an uneven structure has a high degree of freedom regarding the material that can be used as the base material 15. Therefore, it is preferable.

When the color-developing sheet is fixed to the resin adherend using the laminating decoration method, the base material 15 is deformed following the adherend during heating for integration with the adherend. As described above, the base material 15 is made of a thermoplastic resin. Examples of the thermoplastic resin include polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene copolymer (ABS resin), polymethyl methacrylate (PMMA), polyethylene (PE), polypropylene (PP), polycarbonate (PC), and the like. Nylon (PA) and the like can be mentioned. The film thickness of the base material 15 is preferably as thin as possible from the viewpoint that the color-developing sheet easily follows the adherend, and is preferably, for example, about 20 μm or more and 300 μm or less.

As the protective layer 20, a protective layer 20 having absorption of transmitted light of the multilayer film layer 16 is used. When the color-developing sheet is fixed to the resin adherend using the laminating decoration method, the protective layer 20 has an uneven structure of the multilayer film layer 16 during heating for integration with the adherend. It is preferable that the protective layer 20 has a high degree of followability, and from this viewpoint, the protective layer 20 is preferably thermoplastic. Specifically, if the protective layer 20 has a structure having thermoplasticity at a temperature of 100 ° C. or higher and 160 ° C. or lower, the uneven structure of the multilayer film layer 16 is formed during heating in the laminating decoration method. Followability is suitably obtained. In order to realize such a configuration, a thermoplastic resin may be used as the resin in the configuration in which the protective layer 20 contains the black pigment and the resin. Examples of the thermoplastic resin include the thermoplastic resin exemplified as the material of the above-mentioned base material 15.

As shown in FIG. 9, the color-developing structure 34 constituting the color-developing sheet 50 preferably includes an adhesive layer 22 that covers the surface of the protective layer 20 opposite to the multilayer film layer 16. The adhesive layer 22 has a function of adhering the color-developing sheet 50 and the adherend. In FIG. 9, as the color-developing structure 34 constituting the color-developing sheet 50, a color-developing structure having a resin layer 17 laminated on the base material 15 having a concavo-convex structure of a second structure is applied. An example is shown.

When the color-developing sheet is fixed to a resin adherend using a laminating decoration method, the adhesive layer 22 is adhered so as to exhibit an adhesive function during heating for integration with the adherend. The layer 22 preferably has a heat-sealing property. Examples of the heat sealant constituting such an adhesive layer 22 include thermoplastic resins such as polyethylene, polyvinyl acetate, acrylic resin, polyamide, polyester, polypropylene, and polyurethane.

The adhesive layer 22 is formed by using a known coating method such as an inkjet method, a spray method, a bar coating method, a roll coating method, a slit coating method, and a gravure coating method. The film thickness of the adhesive layer 22 is not particularly limited, but is preferably about 2 μm or more and 200 μm or less, for example.

As shown in FIG. 10, the color-developing sheet 50 having the above configuration is fixed to the adherend 61 so that the adhesive layer 22 is in contact with the adherend 61. That is, in the molded body 60 in which the color-developing sheet 50 is fixed to the adherend 61, the base material 15 is directed outward, and the adherend 61 is located on the side where the protective layer 20 is located with respect to the base material 15. .. Then, the color-developing sheet 50 is observed from the base material 15 side.

The color-developing structure 34 constituting the color-developing sheet 50 may be provided with the same antireflection layer as the display body 40 described above. Further, as the structure of the color-developing sheet, any structure can be applied as long as it is the structure of the color-developing structure described above. For example, the protective layer 20 has absorption of transmitted light of the multilayer film layer 16. Instead, it may have only the function of protecting the uneven structure in the multilayer film layer 16, or may have the function of absorbing ultraviolet rays due to the inclusion of the ultraviolet absorber. In these cases, the color-developing sheet is oriented so that the protective layer 20 is directed outward to form the outermost surface of the color-developing sheet, and the adherend 61 is located on the side where the base material 15 is located with respect to the protective layer 20. It is preferable that the color-developing sheet fixed to the adherend 61 is observed from the protective layer 20 side.

As described above, according to the above embodiment, the following effects can be obtained.
(1) In the color-developing structure, since the surface of the multilayer film layer 16 is covered with the protective layer 20, deformation of the uneven structure in the multilayer film layer 16 and clogging of the concave-convex structure can be suppressed. Therefore, it is possible to suppress the change in the optical path length of the light reflected by the multilayer film layer 16 and the decrease in the diffusion effect and the diffraction effect of the reflected light due to the uneven structure, so that the desired color development is preferable in the color-developing structure. Obtained in. Further, since the protective layer 20 is directly laminated on the multilayer film layer 16, the manufacturing process is simplified as compared with the configuration in which the protective layer is provided via the adhesive layer or the like, and the manufacturing cost is increased and the yield is increased. The decrease is suppressed. Then, in the case of the display body 40 having pixels composed of such a color-developing structure and the color-developing sheet 50 composed of such a color-developing structure, the display body 40 and the color-developing sheet 50 in which desired color development can be suitably obtained are realized. Will be done. Further, in the molded body provided with such a color-developing sheet 50, the decorativeness is enhanced.

(2) If the protective layer 20 has a structure that absorbs the transmitted light of the multilayer film layer 16, when the color-developing structure is observed from the side where the uneven layer is located, the multilayer film layer 16 is formed from the uneven layer side. The transmitted light is absorbed by the protective layer 20, and the transmitted light is suppressed from returning to the uneven layer side. Therefore, since the light in the wavelength range different from the light reflected from the multilayer film layer 16 is suppressed from being visually recognized, it is possible to suppress the deterioration of the color visibility due to the reflected light, and the desired color development in the color-developing structure is obtained. It is suitably obtained.

If the protective layer 20 is configured to contain a black pigment, the protective layer 20 can absorb light in a wide wavelength range in the visible region, so that the protective layer 20 can absorb light in a wide wavelength range, regardless of the wavelength range of the light transmitted through the multilayer film layer 16. The protective layer 20 that absorbs transmitted light can be suitably realized.

(3) According to the configuration in which the antireflection layer 21 is provided on the surface of the uneven layer opposite to the multilayer film layer 16, when the color-developing structure is observed from the side where the uneven layer is located, the uneven layer is formed. Since the surface reflection is reduced, the visibility of the color due to the reflected light from the multilayer film layer 16 is suppressed from being lowered, and the desired color development can be preferably obtained in the color-developing structure.

(4) In the configuration in which the adhesive layer 22 is provided on the surface of the protective layer 20 opposite to the multilayer film layer 16, the color-developing structure can be suitably attached to the adherend for decoration or the like. Then, a structure suitable for the purpose of observing the color-developing structure from the side where the uneven layer is located is realized.

(5) If the protective layer 20 is configured to contain an ultraviolet absorber, the protective layer 20 absorbs ultraviolet rays, so that the materials constituting the color-developing structures 30 and 31 are suppressed from being deteriorated by the ultraviolet rays.

(6) If the protective layer 20 is composed of two or more layers, it is possible to increase the functionality of the protective layer 20 and enhance the functions of the protective layer 20 by combining the functions of these layers.
(7) When the hardness measured from the outermost surface of the color-developing structure is 0.03 GPa or more, the scratch resistance of the color-developing structure is enhanced.

(8) When the arithmetic mean roughness on the outermost surface of the color-developing structure is 2 μm or less, diffuse reflection of light on the outermost surface of the color-developing structure can be suppressed. As a result, it is possible to suppress the deterioration of color visibility due to the reflected light from the multilayer film layer 16.
(9) When the water contact angle on the outermost surface of the color-developing structure is 60 degrees or more, deterioration of the color-developing structure due to adhesion of water to the outermost surface can be suppressed.

(10) If the color-developing structure has a concavo-convex structure of the first structure, the effect of diffusing the reflected light can be obtained by the convex portion, and the light in a specific wavelength range is wide as the reflected light from the multilayer film layer 16. Observed at an angle.

(11) If the color-developing structure has a concavo-convex structure having a second structure, the convex portion provides a diffusion effect and a diffraction effect of the reflected light, and a specific wavelength range is obtained as the reflected light from the multilayer film layer 16. The light can be observed at a wide observation angle, and the intensity of the reflected light is increased so that a vivid color with a glossy feeling can be visually recognized.

(12) In the configuration in which the color-developing structure has the uneven structure of the second structure, in the second pattern formed by the projected image of the second convex portion element 15Eb, a plurality of strip-shaped regions are in the first direction Dx and the second direction. It is arranged along each of the Dy, and at least one of the average value and the standard deviation of the sequence spacing of the band-shaped region is different between the sequence spacing along the first direction Dx and the sequence spacing along the second direction Dy. For example, the diffraction effect of the reflected light by the second convex element 15Eb is determined according to the difference between the influence of the scattering effect of the reflected light by the first convex element 15Ea on the first direction Dx and the influence on the second direction Dy. Can be adjusted. Further, in a configuration in which the average value of the array spacing of the first direction Dx and the average value of the array spacing of the second direction Dy in the band-shaped region are each 1 μm or more and 100 μm or less, the diffraction effect of the reflected light is suitably exhibited. The diffraction effect of the reflected light can be adjusted within the range.

(13) In the display body 40 having pixels composed of a color-developing structure, the materials and film thicknesses of the layers constituting the multilayer film layer 16 are the same in the first pixel 42A and the second pixel 42B, and the uneven layer. In the configuration in which the heights of the convex portions are different, colors having different hues are visually recognized in the region where the first pixel 42A is located and the region where the second pixel 42B is located. Since the configurations of the multilayer film layer 16 are the same in the first pixel 42A and the second pixel 42B, it is not necessary to form the multilayer film layer 16 in each region where the pixels 42A and 42B are located, and the multilayer film layer 16 does not need to be formed. The display body 40 having pixels 42A and 42B exhibiting different hues can be formed by a simple manufacturing process.

(14) In the color-developing sheet 50 composed of the color-developing structure, if the protective layer 20 has a thermoplastic structure, the color-developing sheet 50 is fixed to the surface of the adherend 61 by using a laminating decoration method. When this is done, the protective layer 20 can preferably follow the uneven structure of the multilayer film layer 16. Therefore, a suitable configuration is realized as the color-developing sheet 50 fixed to the surface of the adherend by using the laminating decoration method.

(15) In the color-developing sheet 50 composed of the color-developing structure, if the adhesive layer 22 has a heat-sealing property, the color-developing sheet 50 is applied to the surface of the adherend 61 by using the laminating decoration method. When the adhesive layer 22 is brought into contact with the adherend 61 to integrate the color-developing sheet 50 and the adherend 61, the color-developing sheet 50 and the adherend 61 are suitably bonded to each other. Therefore, a suitable configuration is realized as the color-developing sheet 50 fixed to the surface of the adherend 61 by using the laminating decoration method. Further, when the surface of the color-developing sheet 50 on the base material 15 side is fixed to the adherend 61, the base material 15 supports the multilayer film layer 16 and the protective layer 20 on the surface of the adherend 61. High heat resistance is required so that the strength of the base material 15 does not decrease due to the heat applied in the manufacturing process. On the other hand, if the surface on the protective layer 20 side is fixed to the adherend 61, the degree of freedom in selecting the material of the base material 15 is increased.

(16) In the molded body 60 provided with the color-developing sheet 50, the protective layer 20 has absorption of the transmitted light of the multilayer film layer 16, and the adherend 61 is located on the side where the protective layer 20 is located with respect to the uneven layer. In the case of the positional configuration, the color-developing sheet 50 is observed from the side where the uneven layer is located, and the light transmitted through the multilayer film layer 16 is absorbed by the protective layer 20, so that the desired color development can be preferably obtained in the color-developing sheet 50. Be done. That is, since the color-developing sheet 50 is used in such a manner that the color-developing property can be suitably exhibited, the decorativeness of the molded product is enhanced.

(17) If the resin layer 17 covering the surface of the base material 15 has an uneven structure, the degree of freedom in selecting the material of the base material 15 is increased, and the formation of the uneven structure is fine. It is possible to apply a nanoimprint method suitable for forming irregularities.

(18) According to the manufacturing method in which the concavo-convex structure of the concavo-convex layer is formed by using the nanoimprint method, the fine concavo-convex structure can be preferably and easily formed. If the manufacturing method uses an optical nanoimprint method or a thermal nanoimprint method as the nanoimprint method, the formation of an uneven structure by the nanoimprint method is suitable and easily realized.

[Modification example]
The above embodiment can be modified and implemented as follows.
A layer having absorption of transmitted light of the multilayer film layer 16 may be provided on the side opposite to the protective layer 20 with respect to the multilayer film layer 16. For example, such a configuration can be realized by making the base material 15 or the resin layer 17 a black layer, or by arranging the black layer on the surface of the base material 15 opposite to the multilayer film layer 16. In this case, the protective layer 20 is made of a material that is transparent to light in the visible region, and the color-developing structure is observed from the side where the protective layer 20 is located. Further, the antireflection layer 21 may be provided on the protective layer 20, and the adhesive layer 22 may be provided so as to form the outermost surface of the color-developing structure on the base material 15 side.

However, for example, if an attempt is made to form a concavo-convex structure using the optical nanoimprint method, it is necessary to use a photocurable black resin as the resin layer 17, and a black base material 15 or a black resin layer 17 is used. That is, there are many restrictions on the material. Further, the layer that absorbs transmitted light is in direct contact with the multilayer film layer 16 rather than the structure in which the transparent layer such as the base material 15 is sandwiched between the multilayer film layer 16 and the layer that absorbs transmitted light. In this structure, the transmitted light from the multilayer film layer 16 is more efficiently absorbed by this layer, so that the deterioration of the color visibility due to the reflected light is preferably suppressed.

-The color-developing structure may include a layer having ultraviolet absorption as a layer separate from the protective layer 20. For example, the color-developing structure may include a layer containing an ultraviolet absorber on the side opposite to the multilayer film layer 16 with respect to the base material 15. With such a configuration, particularly when the color-developing structure is observed from the side where the base material 15 is located, that is, when the incident light enters the color-developing structure from the side where the base material 15 is located. , The effect of suppressing deterioration of the material constituting the color-developing structure due to ultraviolet rays can be highly obtained.

The pixels included in the display body 40 may include pixels in which the directions of extending the uneven structure in the concave-convex layer in the virtual plane are different from each other. Specifically, the second direction Dy, which is the direction in which the convex portion extends in an arbitrary pixel, and the second direction Dy, which is the direction in which the convex portion extends in a pixel different from this pixel, are different directions. For example, the configuration may be such that these directions are orthogonal to each other. According to such a configuration, it is possible to change the direction in which the reflected light from the multilayer film layer 16 is diffused by the pixels, and it is possible to express a variety of images.

Since the multilayer film layer 16 is also formed on the side surface of the convex portion in the concave-convex layer, the width of the convex portion of the concave-convex structure in the multilayer film layer 16 is slightly wider than the width of the convex portion in the concave-convex layer. In the portion where the pixels having different extending directions of the uneven structure are adjacent to each other, the expanded portions of the multilayer film layer 16 as described above are connected between the convex portions having different extending directions, and the concave-convex structure in the multilayer film layer 16 collapses. When this occurs, it becomes difficult to obtain a desired color from each pixel in a desired direction. Therefore, it is preferable that a region in which the unevenness layer is not formed is provided between the pixels in which the unevenness structure extends in different directions. Further, even between pixels having a concavo-convex structure having the same extending direction, a region in which the concavo-convex layer is not formed may be provided. The collapse of the structure is suppressed at the end of the pixel, and it becomes easy to obtain the desired color from the entire pixel. The width of the region where the unevenness is not formed between the pixels is preferably, for example, ½ or more of the film thickness of the multilayer film layer 16.

The convex portion constituting the concave-convex structure of the concave-convex layer may have a structure in which the width of the first direction Dx gradually decreases from the base portion to the top portion. According to such a configuration, the multilayer film layer 16 is easily formed on the convex portion. In this case, the length d1 and the length d3 of the first direction Dx are defined by the pattern formed by the bottom surface of the convex portion.

The figure constituting the pattern formed by the projected image of the convex portion 15a in the first structure of the concave-convex structure in the concave-convex layer and the pattern formed by the projected image of the first convex portion element 15Ea in the second structure are , Not limited to rectangles. The figure constituting these patterns may be an oval or the like, and in short, it may be a graphic element having a shape in which the length along the second direction Dy is equal to or greater than the length along the first direction Dx. Just do it. Then, it is sufficient that the length d1 of the first direction Dx and the length d2 of the second direction Dy in the graphic element satisfy various conditions described in the description of the first structure.

The outermost layer of the multilayer film layer 16, that is, the layer constituting the outermost surface of the multilayer film layer 16 opposite to the uneven layer may function as a protective layer. In this case, the multilayer film layer 16 is an optical functional layer. The layer that functions as the protective layer may be able to suppress changes that make it difficult to obtain the desired color in the color-developing structure, such as deformation and alteration of the uneven structure in the layer below the protective layer, from at least one viewpoint. ..

Specifically, the outermost layer in the multilayer film layer 16 functions as a protective layer by having different characteristics from the layers other than the outermost layer in the multilayer film layer 16. These properties may be structural properties, chemical properties, or physical properties, such as hardness, thickness, height of unevenness, and water repellency. For example, if the outermost layer has a higher hardness than the other layers or the outermost layer has a larger thickness than the other layers, the outermost layer is more resistant to impact than the other layers, so that the outermost layer is the outermost layer. The uneven structure of the lower layer is protected. Further, if the height of the unevenness in the outermost layer is smaller than that of the other layers, that is, if the flatness of the outermost layer is higher than that of the other layers, the height of the unevenness on the surface of the multilayer film layer 16 becomes smaller. As a result, the impact is less likely to cause deformation of the unevenness, so that the uneven structure of the lower layer than the outermost layer is protected.

Even when the outermost layer of the multilayer film layer 16 has different characteristics from the layers other than the outermost layer, the multilayer film layer 16 as a whole has a surface shape that follows the uneven structure of the uneven layer, that is, the uneven layer. The multilayer film layer 16 has irregularities in an arrangement corresponding to the arrangement of the irregularities in the concave-convex structure, and the reflectance of the light in a specific wavelength range of the incident light incident on the multilayer film layer 16 is in another wavelength range. It is configured to be higher than the reflectance of light.

[Example]
The above-mentioned color-developing structure and a method for producing the same will be described with reference to specific examples.
<Example 1>
The first embodiment is a display body in which a color-developing structure is applied to pixels. The pixel of the display body of the first embodiment is composed of a color-developing structure in which a concave-convex structure of the first structure is formed on a base material.

First, a mold, which is an intaglio plate used in the optical nanoimprint method, was prepared. Specifically, since light having a wavelength of 365 nm was used as the light to be irradiated in the optical nanoimprint method, synthetic quartz that transmits light having this wavelength was used as the material for the mold. In forming the mold, first, a film made of chromium (Cr) was formed on the surface of the synthetic quartz substrate by sputtering, and an electron beam resist pattern was formed on the Cr film by electron beam lithography. The formed pattern is a pattern consisting of a set of a plurality of rectangles shown in FIG. The area to be a pixel is a square with a side of 130 mm, the length of the rectangle in the first direction is 380 nm, and the length of the rectangle in the second direction is normal with an average value of 2400 nm and a standard deviation of 580 nm. The length selected from the distribution. In the above pattern, the plurality of rectangles are arranged so as not to overlap in the first direction. The resist used was a positive type, and the film thickness was 200 nm.

Next, the Cr film in the region exposed from the resist was etched by plasma generated by applying a high frequency to a mixed gas of chlorine (Cl ₂ ) and oxygen (O _2). Subsequently, the synthetic quartz substrate in the region exposed from the resist and the Cr film was etched by the plasma generated by applying a high frequency to the hexafluorinated ethane gas. The depth of the synthetic quartz substrate etched by this was 70 nm. By removing the remaining resist and Cr film, a mold having an uneven structure was obtained.

Subsequently, Optool HD-1100 (manufactured by Daikin Industries, Ltd.) was applied as a mold release agent to the surface of the mold. Then, a photocurable resin (PAK-02, manufactured by Toyo Synthetic) is applied to the surface of the synthetic quartz wafer used as a base material, and the surface on which the unevenness of the mold is formed is pressed against this resin to press the back surface of the mold. Light of 365 nm was irradiated from the side. After the photocurable resin was cured by irradiation with this light, the synthetic quartz wafer and the resin layer were peeled off from the mold. As a result, a synthetic quartz wafer in which a resin layer having a concavo-convex structure was laminated was obtained.

Subsequently, the synthetic quartz wafer _{was etched by plasma using O 2} gas to remove the photocurable resin remaining in the concave portion of the concave-convex structure. In this step, _{40 sccm of O 2} gas was introduced and plasma was discharged. Next, an etching by plasma using a mixed gas of octafluorocyclobutane and (C 4 _{F 8)} and argon (Ar), to transfer the uneven structure having a resin layer on the synthetic quartz wafer. In this _step, C 4 to _{F 8} gas 40 sccm, Ar gas was introduced 60 sccm, after setting the pressure within the plasma chamber 5 mTorr, RIE power 75W, by applying ICP power 400W, it was plasma discharge. The height of the convex portion in the uneven structure formed on the synthetic quartz wafer was set to 100 nm.

Next, organic cleaning using a mixed solution of dimethylsulfoxide: monoethanolamine = 7: 3 (ST-105, manufactured by Kanto Chemical Co., Inc.), and a mixed aqueous solution (SH-303) containing sulfuric acid and hydrogen peroxide as basic components. , Kanto Chemical Co., Inc.) was used for acid cleaning to obtain a synthetic quartz wafer as a base material having a concavo-convex structure, which is the first structure.

Next, on the uneven surface of the synthetic quartz wafer, a TiO _{2 film as a high-refractive index layer having a film thickness of 205 nm and a SiO 2} film as a low-refractive index layer having a film thickness of 100 nm are formed by vacuum vapor deposition. The film was formed alternately to form a multilayer film layer having 5 sets of a high refractive index layer and a low refractive index layer, that is, 10 layers.
_{Next, a SiO 2} film having a film thickness of 100 nm was formed as an antireflection layer on the surface of the synthetic quartz wafer opposite to the surface on which the multilayer layers were laminated by vacuum vapor deposition.

Further, about 4% by mass of carbon nanotube powder is mixed with the acrylic UV curable resin to prepare a black ink, and the black ink is applied to the surface of the multilayer film layer by using the bar coat method, and the coated layer is dried. The protective layer was formed. As a result, the display body of Example 1 was obtained.
When the display body of Example 1 was observed from the side where the antireflection layer was located, green color was confirmed with good visibility in the region where the pixels were located.

<Example 2>
Example 2 is a color-developing sheet to which a color-developing structure is applied, and a molded product using the color-developing sheet. The color-developing sheet of Example 2 is composed of a color-developing structure in which an uneven structure having a second structure is formed on a resin layer on a base material.

First, a mold, which is an intaglio plate used in the optical nanoimprint method, was prepared. Specifically, since light having a wavelength of 365 nm was used as the light to be irradiated in the optical nanoimprint method, synthetic quartz that transmits light having this wavelength was used as the material for the mold. In forming the mold, first, a film made of chromium (Cr) was formed on the surface of the synthetic quartz substrate by sputtering, and an electron beam resist pattern was formed on the Cr film by electron beam lithography. The formed pattern is a pattern consisting of a set of a plurality of rectangles shown in FIG. The length of the rectangle in the first direction is 300 nm, and the length of the rectangle in the second direction is a length selected from a normal distribution with an average value of 2000 nm and a standard deviation of 500 nm. In the above pattern, the plurality of rectangles are arranged so as not to overlap in the first direction. The resist used was a positive type, and the film thickness was 200 nm.

Subsequently, the Cr film in the region exposed from the resist was etched by plasma generated by applying a high frequency to a mixed gas of chlorine (Cl ₂ ) and oxygen (O _2). Subsequently, the synthetic quartz substrate in the region exposed from the resist and the Cr film was etched by the plasma generated by applying a high frequency to the hexafluorinated ethane gas. The depth of the synthetic quartz substrate etched by this was 70 nm. By removing the remaining resist and Cr film, a synthetic quartz substrate having a concavo-convex structure corresponding to the first structure was obtained.

Next, a film made of Cr was formed by sputtering on the surface of the synthetic quartz substrate on which the uneven structure was formed, and an electron beam resist pattern was formed on the Cr film by electron beam lithography. The formed pattern is a pattern composed of a plurality of strip-shaped regions shown in FIG. The length of the band-shaped region in the first direction is 200 nm, the length of the band-shaped region in the second direction is 94 μm, the length of the first direction is 40 μm, and the length of the second direction is 94 μm. The band-shaped regions are arranged for each region, with the arrangement spacing in the first direction set to an average value of 1.5 μm and a standard deviation of 0.5 μm. The electron beam resist used was a positive type, and the film thickness was 200 nm.

Subsequently, the Cr film in the region exposed from the resist was etched by plasma generated by applying a high frequency to a mixed gas of chlorine (Cl ₂ ) and oxygen (O _2). Subsequently, the synthetic quartz substrate in the region exposed from the resist and the Cr film was etched by the plasma generated by applying a high frequency to the hexafluorinated ethane gas. The depth of the synthetic quartz substrate etched by this was 65 nm. After removing the remaining resist and Cr film, Optool HD-1100 (manufactured by Daikin Industries, Ltd.) was applied as a mold release agent to the surface of the synthetic quartz substrate. As a result, a mold having an uneven structure corresponding to the second structure was obtained.

Next, a photocurable resin (PAK-02, manufactured by Toyobo) was applied to the surface of the polyester film (Cosmo Shine A4100, manufactured by Toyobo) that had been easily bonded on one side. The surface on which the unevenness of the mold was formed was pressed against this resin, and light of 365 nm was irradiated from the back surface side of the mold. After the photocurable resin was cured by this light irradiation, the polyester film and the resin layer were peeled off from the mold. As a result, a polyester film as a base material on which a resin layer having a concavo-convex structure having a second structure was laminated was obtained.

_{Next, a TiO 2} film as a high-refractive index layer having a film thickness of 40 nm and a low film thickness of 75 nm were formed on the uneven surface of the obtained laminate of the base material and the resin layer by vacuum deposition. _{The SiO 2} film as the refractive index layer was alternately formed to form 5 sets of the high refractive index layer and the low refractive index layer, that is, a multilayer film layer having 10 layers.

Next, about 4% by mass of carbon nanotube powder was mixed with the acrylic UV curable resin to prepare a black ink, and the black ink was applied to the surface of the multilayer film layer by using the bar coat method. The coated layer was dried at 80 ° C. for 2 minutes and then irradiated with light at 365 nm to form a protective layer having a film thickness of 10 μm.

Subsequently, an acrylic resin was applied to the surface of the protective layer using a bar coating method, and the coated layer was dried at 80 ° C. for 2 minutes to form an adhesive layer having a film thickness of about 50 μm. As a result, the color-developing sheet of Example 2 was obtained.

The molded product of Example 2 was obtained by integrating the color-developing sheet of Example 2 with an adherend made of polycarbonate by using a three-dimensional overlay lamination method. Specifically, the adhesive layer of the color-developing sheet was placed in the molding machine toward the adherend, and the inside of the molding machine was evacuated and then heated to 160 ° C. to bring the color-developing sheet and the adherend into contact with each other. In this state, the coloring sheet and the adherend were integrated by applying pressure from the coloring sheet side to the atmospheric pressure. Then, by cutting off an unnecessary portion of the color-developing sheet, a molded product of Example 2 decorated with the color-developing sheet was obtained.
When the molded product of Example 2 was observed, a glossy blue color was confirmed with good visibility in the portion where the color-developing sheet was located.

Dx ... 1st direction, Dy ... 2nd direction, 10,11,12 ... Concavo-convex structure, 15 ... Substrate, 15a, 15c ... Convex, 15b ... Concave, 15Ea ... First convex element, 15Eb ... Second Convex element, 16 ... Multilayer film layer, 16a ... High refractive index layer, 16b ... Low refractive index layer, 17 ... Resin layer, 20 ... Protective layer, 21 ... Antireflection layer, 22 ... Adhesive layer, 30, 31, 32 , 33, 34 ... Color development structure, 40 ... Display body, 40F ... Front surface, 40R ... Back surface, 41A, 41B ... Display area, 42A, 42B ... Pixels, 50 ... Color development sheet, 60 ... Molded body, 61 ... Adhesive body ..

Claims (24)

An uneven layer with an uneven structure on the surface and
A multilayer film layer having a surface shape that is located on the uneven structure and has a surface shape that follows the concave-convex structure. An optical functional layer including the multilayer film layer in which the reflectance of light in a specific wavelength region of light is higher than the reflectance of light in other wavelength regions, and the uneven layer in the optical functional layer. The outermost layer on the opposite side comprises the optical functional layer having a protective function lower than the outermost layer.
The first direction and the second direction orthogonal to the first direction are directions included in a virtual plane which is a virtual surface on which the uneven structure is projected in the thickness direction of the uneven layer.
The convex portion constituting the uneven structure has a shape of one or more steps, and the pattern formed by the projected image of the convex portion in the virtual plane has a length along the second direction along the first direction. Contains a pattern consisting of a set of multiple graphic elements that are longer than the length
The length of the graphic element along the first direction is less than or equal to the sub-wavelength, and in the plurality of graphic elements, the standard deviation of the length along the second direction is the length along the first direction. Greater than the standard deviation of
A color-developing structure in which the height of the convex portion constituting the pattern composed of the set of the plurality of graphic elements is ½ or less of the peak wavelength of the light in the specific wavelength range reflected from the multilayer film layer. The uneven layer has light transmission to the incident light and has a light transmittance.
The color-developing structure according to claim 1, wherein the protective layer covering the surface of the multilayer film layer as the outermost layer has a light absorption property of absorbing at least a part of the incident light transmitted through the multilayer film layer. .. The color-developing structure according to claim 2, wherein the protective layer contains a black pigment. The color-developing structure according to any one of claims 1 to 3, further comprising an antireflection layer covering a surface of the uneven layer opposite to the optical functional layer. The color-developing structure according to any one of claims 1 to 4, further comprising an adhesive layer covering a surface of the optical functional layer opposite to the uneven layer. The color-developing structure according to any one of claims 1 to 5, wherein the layer constituting the color-developing structure includes a layer containing an ultraviolet absorber. The color-developing structure according to any one of claims 1 to 6, wherein the protective layer covering the surface of the multilayer film layer as the outermost layer is composed of two or more layers. The color-developing structure according to any one of claims 1 to 7, wherein the hardness measured from the outermost surface of the color-developing structure is 0.03 GPa or more. The color-developing structure according to any one of claims 1 to 8, wherein the arithmetic average roughness on the outermost surface of the color-developing structure is 2 μm or less. The color-developing structure according to any one of claims 1 to 9, wherein the water contact angle on the outermost surface of the color-developing structure is 60 degrees or more. The uneven layer is composed of a base material and a resin layer covering the surface of the base material, and any of claims 1 to 10 in which the uneven structure is located on a surface of the resin layer opposite to the base material. The color-developing structure described in item 1. The pattern formed by the projected image of the convex portion in the virtual plane is a pattern composed of a set of the plurality of graphic elements.
The color-developing structure according to any one of claims 1 to 11, wherein the height of the convex portion constituting the uneven structure is constant. The pattern formed by the projected image of the convex portion in the virtual plane is a first pattern composed of a set of the plurality of graphic elements and a plurality of strips extending along the second direction and lining up along the first direction. It is a pattern in which a second pattern consisting of regions is superimposed.
The arrangement spacing of the strip-shaped regions along the first direction is not constant in the plurality of strip-shaped regions, and the average value thereof is ½ or more of the minimum wavelength in the wavelength region included in the incident light.
The convex portion constituting the uneven structure includes a convex portion element in which the projected image on the virtual plane constitutes the first pattern and has a predetermined height, and the projected image on the virtual plane is the second element. The color-developing structure according to any one of claims 1 to 11, which has a multi-stage shape in which convex elements having a predetermined height and elements constituting the pattern are overlapped in the height direction. In the second pattern, the plurality of strip-shaped regions are arranged along each of the first direction and the second direction.
The color-developing structure according to claim 13, wherein at least one of the average value and the standard deviation of the arrangement spacing of the strip-shaped region differs between the arrangement spacing along the first direction and the arrangement spacing along the second direction. In the second pattern, the plurality of strip-shaped regions are arranged along each of the first direction and the second direction.
In the plurality of strip-shaped regions, the average value of the arrangement spacing of the strip-shaped regions along the first direction and the average value of the arrangement spacing of the strip-shaped regions along the second direction are 1 μm or more and 100 μm or less. The color-developing structure according to claim 13 or 14. A display body having a plurality of display elements and having a front surface and a back surface.
A display body in which the display element is composed of the color-developing structure according to any one of claims 1 to 15. The plurality of display elements include a first display element and a second display element.
When viewed from a direction facing the surface of the display body, the display body includes a first display area in which the first display element is located and a second display area in which the second display element is located.
The material and film thickness of each layer constituting the multilayer film layer are the same in the first display element and the second display element.
The display body according to claim 16, wherein the height of the convex portion in the concave-convex layer included in the first display element and the height of the convex portion in the concave-convex layer included in the second display element are different from each other. A color-developing sheet composed of the color-developing structure according to any one of claims 1 to 15. The color-developing sheet according to claim 18, wherein the protective layer covering the surface of the multilayer film layer as the outermost layer of the optical functional layer has thermoplasticity. A color-developing sheet composed of the color-developing structure according to claim 5.
The adhesive layer is a color-developing sheet having heat-sealing properties. The color-developing sheet according to any one of claims 18 to 20 and
A molded body comprising an adherend to which the color-developing sheet is fixed. A color-developing sheet composed of the color-developing structure according to claim 2 or 3.
With an adherend to which the color-developing sheet is fixed,
A molded body in which the adherend is located on the side where the protective layer is located with respect to the uneven layer. A process of forming an uneven layer having an uneven structure on the surface by transferring the unevenness of the intaglio to a resin using a nanoimprint method.
On the uneven structure, the optical functional layer including the multilayer film layer has different refractive indexes of the layers adjacent to each other in the multilayer film layer, and in a specific wavelength range of the incident light incident on the multilayer film layer. The reflectance of light in the above is higher than the reflectance of light in other wavelength ranges, and the outermost layer of the optical functional layer opposite to the uneven layer has a protective function of a layer lower than the outermost layer. Including the process of forming,
The first direction and the second direction orthogonal to the first direction are directions included in a virtual plane which is a virtual surface on which the uneven structure is projected in the thickness direction of the uneven layer.
In the step of forming the concavo-convex layer, the pattern formed by the projection image of one or more convex portions constituting the concavo-convex structure in the virtual plane has a length along the second direction along the first direction. saw including a composed pattern from a set of a plurality of graphic elements is greater than or equal to the length, the height of the convex portion constituting a pattern of the set of the plurality of graphic elements in the relief structure, reflected from the multilayer film The uneven structure is formed so as to be 1/2 or less of the peak wavelength of the light in the specific wavelength range.
The length of the graphic element along the first direction is less than or equal to the sub-wavelength, and in the plurality of graphic elements, the standard deviation of the length along the second direction is the length along the first direction. A method of manufacturing a color-developing structure that is larger than the standard deviation of. The method for producing a color-developing structure according to claim 23, wherein the nanoimprint method is an optical nanoimprint method or a thermal nanoimprint method.

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