JP2019109414A - Coloring structure, display body and manufacturing method of coloring structure - Google Patents

Abstract

To provide a coloring structure which allows for the excellent visual recognition of the reflection light in a specific wavelength region.SOLUTION: A coloring structure includes: an uneven layer 20 which transmits light in a visible region and has a first uneven structure; one or more interference layers 40 arranged on the uneven layer 20, having the surface shape following the first uneven structure, and having the reflectivity of the light in the specific wavelength region of the incident light higher than the reflectivity of the light in the other wavelength region; and an anti-reflection layer 30 arranged on the surface on the side opposite to the interference layers 40 of the uneven layer 20 and absorbing at least a portion of the light transmitting the interference layers 40. In the plan view, a region of a protrusion 20a constituting the first uneven structure is constituted by combining a plurality of preset band-like patterns Po. The band-like pattern Po has the width along the first direction in the plan view and the length along the second direction orthogonal to the first direction. The width is shorter than the wavelength of the incident light. The plurality of band-like patterns Po constituting the region of the protrusion 20a have the standard deviation of the length larger than the standard deviation of the width.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a color forming structure exhibiting a structural color, a display including the color forming structure, and a method of producing a color forming structure.

The structural color developed by the fine structure is different from the color perceived by the electronic transition like the metallic gloss and the color exhibited by the pigment, and is caused by the fine structure of the object such as light diffraction, interference or scattering It is a color visually recognized by the action of an optical phenomenon.
For example, the structural color due to multilayer film interference is a structural color generated by interference of light reflected at each interface of the multilayer film in multilayer films having mutually different thin films having different refractive indexes. Multilayer interference is one of the coloring principles of the wing of the morpho butterfly, a natural organism. At the wing of the morpho butterfly, bright blue is visible due to multilayer interference.
As a structure that artificially reproduces such a structural color, for example, Patent Document 1 proposes a structure in which a multilayer film layer is laminated on the surface of a substrate in order to reproduce the color-forming structure of the wing of a morpho butterfly.
Moreover, in patent document 2, the narrow-band reflection peak corresponding to each of red, green, and blue from a part of incident light is formed by forming the several thin film from which a refractive index and a film thickness differ sequentially on the surface of a base material. A structure is proposed that reflects interference light and has an iridescent decorative effect.

JP, 2005-153192, A JP, 2010-201644, A

Here, in the techniques of Patent Document 1 and Patent Document 2, a specific wavelength range of incident wavelengths is reflected by setting the film thickness, the number of layers, and the like of the multilayer film layers stacked on a plane. However, not only the reflected light of the specific wavelength by the multilayer film layer, but also the light transmitted from the back side and the light reflected from other than the multilayer film layer such as the base material are also viewed together, so the observer It also recognizes light outside the wavelength range. That is, there is a problem that the visibility of a specific wavelength range is reduced.
An object of the present invention is to provide a color forming structure, a display, and a method of manufacturing a structure capable of favorably visually recognizing reflected light of a specific wavelength range set in the interference layer.

  In order to achieve the above object, a color forming structure according to an aspect of the present invention includes a concavo-convex layer having a first concavo-convex structure that transmits light in a visible region and is disposed on the concavo-convex layer; One or more interference layers having a surface shape following the structure and having a reflectance of light in a specific wavelength range of incident light higher than a reflectance of light in other wavelength ranges, and the uneven layer And an anti-reflection layer disposed on the side opposite to the interference layer to absorb at least a part of the light transmitted through the interference layer, and the convex constituting the first uneven structure in plan view The area of the part is configured by combining a plurality of band patterns set in advance, and the band pattern has a width along the first direction and a length along the second direction orthogonal to the first direction in a plan view. And the width is shorter than the wavelength of the incident light, and the plurality of Jo pattern, the standard deviation of the length is being greater than the standard deviation of the width.

A display according to another aspect of the present invention is characterized by including a display element including the color forming structure of the above aspect.
Furthermore, a display according to another aspect of the present invention is a display having a display element including the color forming structure according to the above aspect, comprising a plurality of the display elements in a plane, and among the plurality of display elements In a color forming structure forming one display element and a color forming structure forming another display element of the plurality of display elements, a convex portion forming the first uneven structure of the uneven layer It is characterized in that the heights are different or the shapes of the concavo-convex structure of the anti-reflection layer are different.
Furthermore, the method for producing a color forming structure according to another aspect of the present invention is the method for producing a color forming structure according to the above aspect, which is for transfer corresponding to the first uneven structure or the second uneven structure. Using the intaglio plate on which the concavo-convex structure is formed, and transferring the concavo-convex structure for transfer to the resin by nanoimprinting method to form the first concavo-convex structure or the second concavo-convex structure And

  According to one aspect of the present invention, reflected light in an arbitrary wavelength range can be favorably viewed.

It is sectional drawing which shows an example of the coloring structure which concerns on one Embodiment of this invention. It is a schematic block diagram which shows an example of an uneven | corrugated layer, Comprising: (a) is a top view, (b) is sectional drawing. It is explanatory drawing for demonstrating a 2nd strip | belt-shaped shape, Comprising: (a) is a top view, (b) is sectional drawing. It is a schematic block diagram which shows an example of a multistage uneven | corrugated layer, Comprising: (a) is a top view, (b) is sectional drawing. It is a schematic block diagram which shows an example of an interference layer. It is a schematic block diagram which shows the 1st form of a reflection preventing layer. It is a schematic block diagram which shows an example of the uneven structure of the reflection preventing layer shown in FIG. 6, Comprising: (a) is a back view, (b) is sectional drawing. It is an explanatory view for explaining a modification of a coloring structure. It is a schematic block diagram which shows the 2nd form of a reflection prevention layer. It is a schematic block diagram which shows an example of the uneven structure of the reflection preventing layer shown in FIG. 9, Comprising: (a) is a back view, (b) is sectional drawing. It is explanatory drawing required for description of the uneven structure shown in FIG. It is an explanatory view for explaining a modification of a coloring structure. It is sectional drawing which shows the other example of a coloring structure. It is sectional drawing which shows the other example of a coloring structure. It is a top view which shows an example of a display body.

In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present invention. However, it is apparent that other embodiments can be practiced without being limited to such specific specific configurations. In addition, the following embodiments do not limit the invention according to the claims, and include all combinations of characteristic configurations described in the embodiments.
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same parts are denoted by the same reference numerals. However, the drawings are schematic, and the relationship between the thickness and the planar dimension, the ratio of the thickness of each layer, and the like are different from actual ones.

[Coloring structure]
As shown in FIG. 1, the coloring structure 1 is provided on the base 10 and on one side of the base 10, and has an uneven layer 20 having a plurality of uneven structures and transmitting light in the visible region, and an antireflective layer The reflection preventing layer 30 is provided on the surface of the base 10 opposite to the surface on which the concavo-convex layer 20 is provided, and transmits the interference layer 40. Absorb at least part of the light. The interference layer 40 has a surface shape that follows the uneven structure of the uneven layer 20. That is, in cross section, the interference layer 40 is formed on the upper surface of the recess and the upper surface of the protrusion of the uneven layer 20.
As the concavo-convex structure (first concavo-convex structure) which the concavo-convex layer 20 has, any of the first form and the second form to be described later can be applied. In addition, the shape of the uneven structure which the uneven | corrugated layer 20 has is not restricted to this. Moreover, also as the reflection preventing layer 30, any of the first form and the second form described later is applicable. These will be described with reference to specific figures.

In addition, although the wavelength range of the incident light to the coloring structure 1 and a reflected light is not specifically limited, In the following description, the coloring structure 1 which made object the light of a visible region as an example is demonstrated. In the present embodiment, light in a wavelength range of 360 nm to 830 nm is used as light in the visible region.
Here, the width direction of the coloring structure 1 is a first direction, the depth direction is a second direction, and the thickness direction is a third direction. The first direction and the second direction are virtual surfaces projected in the third direction, and the first direction and the second direction, and the first direction and the third direction are orthogonal to each other. In the following description, the interference layer 40 side of the color forming structure 1 may be referred to as the front surface side, and the opposite side of the antireflection layer 30 may be referred to as the back surface side.

<First form of the concavo-convex structure of the concavo-convex layer>
Next, details of the concavo-convex structure of the concavo-convex layer 20 will be described. The concavo-convex layer may be any of or a combination of a thermoplastic resin, a thermosetting resin, and a photo-curing resin, as long as the concavo-convex layer is a resin on which the concavities and convexities are formed. Preferably, when the photo-curing resin is used, the layers from the concavo-convex layer 20 to the antireflection layer 30 can be made of one material. The refractive index of the uneven layer 20 is preferably 1.3 or more and 1.5 or less.
First, as an example of the concavo-convex layer 20, the case where the shape in plan view of the convex portion 20a forming the concavo-convex structure, that is, the pattern is the first band-like shape 201 will be described.
FIG. 2 is a schematic view showing an example of the uneven layer 20 in which the pattern of the convex portions 20 a is the first band-like shape 201. In FIG. 2, the antireflection layer 30 and the interference layer 40 are not shown for simplicity.

  2 (a) is a plan view of the color developing structure 1 shown in FIG. 1 as viewed from the interference layer 40 side, and FIG. 2 (b) is an α-α of the uneven layer 20 shown in FIG. 2 (a). It is sectional drawing which shows the cross-section in a 'cross section. As shown in FIG. 2A, the concavo-convex structure of the concavo-convex layer 20 has a shape in which the plurality of convex portions 20a extend in a strip shape having an irregular length in the second direction. As shown in FIG. 2B, the concavo-convex structure of the concavo-convex layer 20 is composed of a plurality of convex portions 20a and a plurality of concave portions 20b which are regions in which the convex portions 20a are not formed. The protrusion 20a is one step higher than the recess 20b.

The first band-like shape 201 which is a pattern of the convex portions 20a in a plan view has a shape extending in the second direction, and the length d2 in the second direction is equal to or longer than the length d1 in the first direction. . The plurality of first strip shapes 201 are arranged so as not to overlap with each other in any of the first direction and the second direction.
In the plan view shown in FIG. 2A, the first strip shape 201 is configured by combining a plurality of strip patterns Po set in advance.
Here, in the strip pattern Po, the length in the first direction (that is, the width of the strip pattern) d1 is constant, and the strip pattern Po has an arrangement interval of the length d1 in the first direction, that is, a cycle of the length d1. It is arranged by.

  On the other hand, in the strip pattern Po, the length in the second direction (that is, the length of the strip pattern) d2 is irregular, and the strip pattern constituting the first strip shape 201 of the convex portion 20a constituting the uneven layer 20 The length d2 of each Po is a value selected from a population having a predetermined standard deviation. This population preferably follows a normal distribution. The arrangement pattern of the band-like patterns Po constituting the first band-like shape 201 of all the convex portions 20a constituting the concavo-convex layer 20 is, for example, a plurality of band-like patterns Po having a length d2 distributed with a predetermined standard deviation. Temporarily laid out in the area, and the presence or absence of the actual arrangement of each band-shaped pattern Po is determined according to a certain probability, and is determined by setting the area where the band-shaped pattern Po is arranged and the area where the band-shaped pattern Po is not arranged. . In order to efficiently scatter the reflected light from the coloring structure 1, 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 band-like pattern Po is arranged is the area to be the first band-like shape 201, that is, the area where the convex portion 20a is arranged, and when the adjacent band-like patterns Po are in contact with each other One region in which the regions where Po are arranged is combined is one first band-like shape 201, and the convex portion 20a is arranged. In such a configuration, the length in the first direction of the first strip shape 201 is an integral multiple of the length d1 of the strip pattern Po.

  In order to suppress the occurrence of iridescent spectroscopy due to the shape of the concavo-convex structure of the concavo-convex layer 20, the length d1 in the first direction of the strip pattern Po is made equal to or less than the wavelength of light in the visible region. In other words, the length d1 of the strip pattern Po has a length equal to or less than the sub-wavelength, that is, equal to or less than 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. Furthermore, it is preferable that the length d1 be smaller than the peak wavelength of the light of the “specific wavelength range” to be reflected. For example, the length d1 is preferably about 300 nm when the blue color is developed in the color forming structure 1, and the length d1 is preferably about 400 nm when the green color is developed in the color forming structure 1. In the case where the color developing structure 1 develops a red color, the length d1 is preferably about 460 nm. Here, the “specific wavelength range” refers to a wavelength range set in advance as a wavelength range of light that the observer wants to visually recognize.

  In order to increase the spread of the reflected light from the color forming structure 1, that is, to enhance the scattering effect of the reflected light, it is preferable that the unevenness of the uneven structure be large, and in plan view, the first band per unit area The ratio of the area occupied by the shape 201 is preferably 40% or more and 60% or less. For example, in plan view, the ratio of the area of the first band shape 201 per unit area, that is, the area of the convex portion 20a, to the area of the region 202 which is not the first band shape 201, that is, the area of the recess 20b is 1: 1. Is preferred.

  As shown in FIG. 2 (b), the height h 1 of the convex portion 20 a is constant, and the height h 1 is a desired color to be colored in the color forming structure 1, that is, a desired color to be reflected from the color forming structure 1. It may be set according to the wavelength range to be used. If the height h1 of the convex portion 20a is larger than the surface roughness of the upper surface of the convex portion 20a and the surface roughness of the upper surface of the concave portion 20b, the scattering effect of the reflected light can be obtained. When the height h1 is different among the plurality of convex portions 20a in the concavo-convex layer 20, although higher scattered light is produced, the reflected light becomes smaller and the contrast of the color to be recognized becomes low, so the height h1 of the convex portion 20a is It is preferable that it is constant.

  However, in order to suppress light interference caused by reflection of the uneven structure on the surface of the convex portion 20a, the height h1 is preferably 1/2 or less of the wavelength of light in the visible region, that is, 415 nm or less Is preferred. Furthermore, in order to suppress the interference of the light resulting from the reflection in the said uneven structure, the height h1 is 1/2 or less of the peak wavelength which the light of the "specific wavelength range" reflected from the interference layer 40 has Is more preferred.

  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 It is preferable that it is the following. For example, in the color forming structure 1 exhibiting a blue color, in order to obtain an effective light spread, the height h1 is preferably about 40 nm or more and 150 nm or less, in order to suppress the scattering effect from becoming too high. The height h1 is preferably 100 nm or less.

  The first band-like shape 201 may be configured to be arranged such that a part of two band-like patterns Po aligned in the first direction overlap with each other. That is, the plurality of strip patterns Po may be arranged at an arrangement interval smaller than the length d1 in the first direction, and the arrangement interval in the first direction of the strip patterns Po may not be constant. When the strip patterns Po overlap, one region in which the regions formed by the overlapping strip patterns Po are combined becomes one first strip shape 201. In this case, the length in the first direction of the first strip shape 201 is a length different from an integral multiple of the length d1 of the strip pattern Po. In addition, the length d1 of the strip patterns Po does not have to be constant, and in each of the strip patterns Po, the length d2 in the second direction is equal to or greater than the length d1 in the first direction. The standard deviation of the length d2 may be larger than the standard deviation of the length d1. Also by such a configuration, the scattering effect of the reflected light can be obtained. The cross section of the strip pattern Po does not have to be rectangular, and may have an oval or circular shape with rounded corners.

<Second form of the concavo-convex structure of the concavo-convex layer>
Next, as a concavo-convex layer, in place of the concavo-convex layer 20, a concavoconvex having a multi-step concavoconvex structure 21a, which forms a pattern including a plurality of first strip shapes 201 and second strip shapes 211. The layer 21 will be described.
In the concavo-convex structure 21c shown in FIG. 3 having the convex portion 21b whose planar view is the second strip shape 211, the planar view shown in FIG. 2 shows the convex portion 21b while maintaining the arrangement position and height thereof. When stacked on the convex portions 20 a to be the first strip shape 201, a pattern formed of the convex portions 21 a having the multi-step uneven structure shown in FIG. 4 is formed. As shown in FIG. 4, the pattern constituted by the concavo-convex structure 21 c constituted by the convex portion 20 a and the convex portion 21 b is different from the first strip shape 201 constituted by the concavo-convex layer 20. That is, the configuration of the uneven structure body is different between the uneven layer 20 and the uneven layer 21.

In the following, the uneven layer 21 will be described focusing on the differences from the above-described uneven layer 20, and the same components as those of the uneven layer 20 will be assigned the same reference numerals and descriptions thereof will be omitted.
According to the concavo-convex layer 20, although the change by the observation angle of the color recognized by the scattering effect of the reflected light becomes gentle, the vividness of the color recognized is reduced by the reduction of the intensity of the reflected light due to the scattering. . Depending on the application of the color forming structure 1 and the like, a structure capable of observing more vivid colors at a wide viewing angle may be required. In the concavo-convex layer 21, the convex portions 21 b constituting the second strip shape 211 are arranged so as to generate diffracted light with high reflection intensity, and the convex portion 20 a with the first strip shape 201 viewed in plan The light scattering effect and the light diffraction effect of the light from the convex portions 21 b having the second strip shape 211 in plan view realize coloring that enables more vivid colors to be observed at a wide observation angle.

The configuration of the second strip shape 211 will be described with reference to FIG. FIG. 3 (a) is a plan view of the concavo-convex structure 21c having the convex portions 21b constituting the second strip shape 211, and FIG. 3 (b) is a sectional view taken along the line β-β ′ of FIG. 3 (a). It is sectional drawing which shows a cross-section.
As shown in the plan view of FIG. 3A, the second strip shape 211 has a strip extending with a constant width along the second direction, and the plurality of second strip shapes 211 have a first direction. Along the line, spaced apart. In other words, in plan view, the pattern formed by the plurality of second strip shapes 211 extends along the second direction, and includes a plurality of strip regions aligned along the first direction. The length d3 of the second strip shape 211 in the first direction may or may not be the same as the length d1 of the first strip shape 201 in the first direction.

  The arrangement interval de of the second strip shape 211 in the first direction, that is, the arrangement interval of the second strip shape 211 in the first direction, is a concavo-convex structure having a convex portion 21 b whose plan view becomes the second strip shape 211 At least a part of the reflected light on the surface of the body 21c is set to be observed as first-order diffracted light. The first-order diffracted light is, in other words, diffracted light whose diffraction order m is 1 or -1. That is, assuming that the incident angle of incident light is θ, the reflection angle of reflected light is φ, and the wavelength of light to be diffracted is λ, the arrangement interval de satisfies de ≧ λ / (sin θ + sin φ). For example, when targeting visible light with λ = 360 nm, the arrangement interval de of the second strip shape 211 may be 180 nm or more, that is, the arrangement interval de is the minimum wavelength in the wavelength range included in incident light It is sufficient if it is 1/2 or more of. The arrangement interval de is a distance along the first direction between the end portions of two adjacent second band-like shapes 211, and is the same side as the second band-like shape 211 in the first direction. The distance between the end portions located at the side, that is, for example, the distance between the sides on the right side in the longitudinal direction of the two adjacent second band-like shapes 211 in FIG. 3A, for example.

  The periodicity of the arrangement pattern of the second strip shape 211 constituted by the convex portions 21 b included in the concavo-convex structure 21 c is the periodicity of the concavo-convex structure of the base material 10, that is, the below-described in the surface of the antireflective layer 30. It is reflected in the periodicity of the uneven structure. In the case where the arrangement interval de of the plurality of second strip shapes 211 is constant, in the case where the antireflective layer 30 includes the metal layer 50 described later, the metal layer 50 is formed by the diffraction phenomenon on the surface of the metal layer 50. From the above, reflected light of "specific wavelength" is emitted at a specific angle. The reflection intensity of light due to this diffraction is very strong compared to the reflection intensity of the reflected light caused by the scattering effect of the light by the first band shape 201 described in the description of the first band shape 201 described above. Although light having a brilliance such as gloss is visible, on the other hand, a spectrum due to diffraction occurs, and the color to be viewed changes according to the change of the observation angle.

  Therefore, for example, even if the structure of the first strip shape 201 is designed so as to obtain the color forming structure 1 exhibiting blue, the arrangement interval de of the second strip shape 211 is set to a constant value of about 400 nm to 5 μm. Then, 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 strip shape 211 is increased to about 50 μm, the range of the angle at which light in the visible region is diffracted becomes narrow, so that color change due to diffraction is less visible However, light with brilliance like metallic luster is only observed at certain viewing angles.

  Therefore, if the arrangement pattern of the plurality of second strip shapes 211 is a pattern in which a plurality of periodic structures having different periods are superimposed, without setting the arrangement interval de to a constant value, the reflected light due to diffraction has a plurality of wavelengths. Because the light is mixed, it is difficult for the dispersed light with high monochromaticity to be viewed. Therefore, bright and vivid colors are observed at a wide viewing angle. In this case, the arrangement interval de is selected, for example, from the range of 360 nm to 5 μm, and the average value of the arrangement intervals de of the plurality of second strip shapes 211 is 1/1 / the minimum wavelength in the wavelength range included in the incident light. It is sufficient if it is 2 or more.

  However, as the standard deviation of the arrangement interval de increases, the arrangement of the second band-like shapes 211 becomes irregular, the scattering effect becomes dominant, and it becomes difficult to obtain strong reflection by diffraction. Therefore, according to the angle at which the light spreads due to the light scattering effect of the first band-shaped shape 201, the reflected light due to diffraction is in the same range as the range in which this light spreads. It is preferable to decide to be emitted. For example, in the case where the blue reflected light is emitted while spreading in a range of ± 40 ° with respect to the incident angle, in the arrangement pattern of the second strip shape 211, the arrangement interval de is an average value of 1 μm to 5 μm. The standard deviation is set to be about 1 .mu.m. As a result, due to the scattering effect of the light of the first band-like shape 201, the reflected light due to diffraction is generated at an angle substantially the same as the angle at which the light spreads.

  Furthermore, in order to generate a longer period diffraction phenomenon, a square area of 10 μm to 100 μm on a side is taken as a unit area, and the arrangement interval of the second strip shape 211 arranged in this area for each unit area The average value of de may be about 1 μm to 5 μm, and the standard deviation may be about 1 μm. Note that, among the plurality of unit regions, a region having a constant value in which the arrangement interval de is included in the range of 1 μm to 5 μm may be included. Even if there is a unit area in which the arrangement interval de is constant, if the arrangement interval de has a variation of about 1 μm in any of the unit areas adjacent to this unit area, the resolution of human eyes Can be expected to have the same effect as the configuration in which the arrangement interval de has variation in all unit regions.

  The second band-like shape 211 shown in FIG. 3 has periodicity due to the arrangement interval de only in the first direction. The scattering effect of light by the first strip shape 201 mainly acts on the reflected light in the direction along the first direction, but may partially affect the reflected light in the direction along the second direction. Therefore, the second strip shape 211 may have periodicity in the second direction. That is, the arrangement pattern of the second strip shape 211 may be a pattern in which a plurality of strip regions extending in the second direction are arranged along each of the first direction and the second direction.

  In the arrangement pattern of the second strip shape 211, for example, each of the arrangement interval along the first direction and the arrangement interval along the second direction of the second strip shape 211 has an average value of 1 μm or more. It is sufficient that the variation is made to be 100 μm or less. Also, according to the difference between the influence of the first band shape 201 in the first direction and the influence of the light scattering effect in the second direction, the average value of the arrangement interval along the first direction, and the second direction The average value of the arrangement intervals along the first direction may be different from each other, and the standard deviation of the arrangement intervals along the first direction may be different from the standard deviation of the arrangement intervals along the second direction.

  A plurality of second strip shapes 211 are arranged along each of the first direction and the second direction, and at least one of the average value and the standard deviation of the arrangement intervals of the second strip shapes 211 is along the first direction By making the arrangement interval different from the arrangement interval along the second direction, the first band-like shape 201 is periodically arranged only in the first direction, and the light scattering effect of the first embodiment It is preferable because the light diffraction effect of the second strip shape 211 can be adjusted according to the difference between the influence in one direction and the influence in the second direction.

  As shown in FIG. 3 (b), the height h2 of the convex portion 21b which is the second strip shape 211 in plan view is formed on the convex portion 21b and on the region where the convex portion 21b is not formed. It may be larger than the surface roughness of the interference layer 40. However, as the height h2 increases, the diffraction effect of the convex portion 21b in which the plan view becomes the second strip shape 211 becomes dominant in the effect of the concavo-convex structure on the reflected light, and the plan view is the first strip shape Since it is difficult to obtain the light scattering effect of the convex portion 20a to be 201, the height h2 of the convex portion 21b is preferably about the same as the height h1 of the convex portion 20a, and the height h2 is the height h1 It may match. For example, the height h1 of the convex portion 20a and the height h2 of the convex portion 21b are preferably included in the range of 10 nm to 200 nm, and the height h1 of the convex portion 20a in the color forming structure exhibiting blue color The height h2 of the projection 21b and the height h2 of the projection 21b are preferably in the range of 10 nm to 150 nm.

The details of the uneven layer 21 will be described with reference to FIG. FIG. 4A is a plan view of the concavo-convex layer 21 as viewed from the side of the interference layer 40, and FIG. 4B is a cross-sectional view showing a cross-sectional structure in the γ-γ ′ cross section of FIG. .
In the plan view shown in FIG. 4A, the pattern formed by the first strip shape 201 and the second strip shape 211 constituting the uneven layer 21 is the first strip shape 201 shown in FIG. It becomes a pattern in which the second strip shape 211 shown in FIG. 3 is superimposed. That is, in the concavo-convex layer 21, the region where the convex portion 21 a is located is the region 213 constituted only by the first strip shape 201, the region 214 constituted only by the second strip shape 211, and the first strip shape And an area 215 where the second band shape 211 overlaps the second band shape. The other area 216 is an area where the convex portion 21 a is not formed.
In addition, in FIG. 4, although the 1st strip shape 201 and the 2nd strip shape 211 overlap so that the edge part may align in a 1st direction, it does not restrict to such a structure, The 1st strip shape The end of the shape 201 and the end of the second strip shape 211 may be offset in the first direction.

  As shown in FIG. 4B, the height of the portion corresponding to the region 213 in the convex portion 21a corresponds to the first strip shape 201 based on the region 216 in which the convex portion 21a is not formed. Height h1 of the protruding portion 20a. Further, the height of the portion corresponding to the area 214 in the convex portion 21 a is the height h 2 of the convex portion 21 b corresponding to the second strip shape 211. Similarly, the height of the portion corresponding to the region 215 is the sum of the height h 1 of the convex portion 20 a corresponding to the first strip shape 201 and the height h 2 of the convex portion 21 b corresponding to the second strip shape 211. (= H3). That is, in the uneven layer 21, the convex portion 20 a of the first strip shape 201 having the predetermined height h 1 and the convex portion 21 b of the second strip shape 211 having the predetermined height h 2 are in the height direction. It has an overlapping multi-stage shape.

  As described above, according to the coloring structure 1 having the concavo-convex layer 21, the light diffusion phenomenon caused by the convex portion 20 a having the first band-like shape 201 and the convex portion 21 b having the second band-like shape 211 Due to the synergy with the diffraction phenomenon of the resulting light, it is possible to observe the reflected light in the “specific wavelength range” at a wide observation angle, and the intensity of this reflected light is enhanced to make the bright color with a glossy feeling visible Be done. In other words, in the concavo-convex layer 21, since the concavo-convex structure is a multi-stage structure while being a single structure, it has two functions of the light diffusion function and the light diffraction function.

  The first strip shape 201 and the second strip shape 211 may be arranged so as not to overlap in plan view. Also with such a structure, it is possible to obtain the diffusion effect of light by the first strip shape 201 and the diffraction effect of light by the second strip shape 211. However, if the first band-shaped shape 201 and the second band-shaped shape 211 are arranged so as not to overlap with each other, the locatable area of the first band-shaped shape 201 per unit area becomes small, and light diffusion The effect is reduced. Therefore, in order to enhance the light diffusion effect and the diffraction effect by the first band shape 201 and the second band shape 211, as shown in FIG. 4, the first band shape 201 and the second band shape are provided. It is preferable to make the convex part 21a into a multistage shape so that 211 and may overlap. The same effect can be obtained even if the first strip shape 201 is disposed on the second strip shape 211.

<Interference layer>
Next, the interference layer 40 will be described with reference to FIG. Here, as shown in FIG. 5, a case will be described in which the multi-step uneven layer 21 in which the plan view shown in FIG. 4 has a pattern including the first strip shape 201 and the second strip shape 211 is provided. However, in place of the uneven layer 21, the same applies to the case where the uneven layer 20 having only the convex portions 20 a in which the planar view shown in FIG.
The interference layer 40 has a surface shape that follows the uneven structure of the uneven layer 21. That is, in cross section, the interference layer 40 is formed on the upper surface of the recess and the upper surface of the protrusion of the uneven layer 21. When the interference layer 40 is a single layer, thin film interference occurs, and the phase is reversed under the following conditions. Therefore, when the refractive index n and the optical path difference l, the image becomes bright under the condition of 2nl = (m + 1/2). Also, when the interference layer 40 is composed of two or more layers, multilayer film interference occurs.

  When the interference layer 40 has a multilayer configuration of two or more layers, the interference layer 40 has a structure in which high refractive index layers 40 a and low refractive index layers 40 b are alternately stacked. The refractive index of the high refractive index layer 40a is larger than the refractive index of the low refractive index layer 40b. If the difference in refractive index between the high refractive index layer 40a and the low refractive index layer 40b is about 0.6 or more and 2.2 or less, the "specific wavelength region" with a small number of layers in order to increase interference light with a small number of layers. Is preferable because the reflection of the The interference layer 40 in FIG. 5 is stacked on the concavo-convex layer 21 along the concavo-convex structure of the concavo-convex layer 21 and has a concavo-convex structure in which concavities and convexities are repeated along the concavo-convex structure of the concavo-convex layer 21. And the low refractive index layers 40b are alternately stacked, and has a total of 10 layers, but is not particularly limited thereto.

  When light is incident on the interference layer 40 configured in this way, the light reflected at each interface between the high refractive index layer 40 a and the low refractive index layer 40 b in the interference layer 40 causes interference, and the light on the surface of the interference layer 40 As a result of changing the traveling direction due to the irregular asperity, light of “specific wavelength range” is emitted at a wide angle. The "specific wavelength range" strongly emitted as the reflected light is the refractive index and extinction coefficient of the material constituting the high refractive index layer 40a and the low refractive index layer 40b, the film thickness, the width of the convex portion, the height and It depends on the arrangement.

The material constituting the interference layer 40 is not particularly limited to the following materials, but when one or more compounds of a fluorine-based compound, a silicon-based compound, a titanium-based compound, and a niobium-based compound are included, color development occurs. Since it also functions as a protective layer for protecting the structure 1, the scratch resistance is improved. When the interference layer 40 has a multilayer film structure, a protective layer may be provided on the multilayer film on the side opposite to the substrate 10, that is, on the surface side of the color forming structure 1.
Since the film thickness is thin as the film thickness of the interference layer 40 is 5 nm or more and 2000 nm or less, it can be inexpensively produced. The interference effect is higher as 5 nm or more and 1000 nm or less is preferable.

<First Form of Antireflection Layer>
Next, the first embodiment of the antireflective layer 30 will be described with reference to FIGS. 6 and 7. Here, as shown in FIG. 6, a case is described in which the uneven layer 20 includes the uneven layer 20 having only the convex portions 20 a in which the plan view shown in FIG. Alternatively, the same applies to the case where the multi-step uneven layer 21 having a pattern including the first strip shape 201 and the second strip shape 211 in plan view is provided.
FIG. 6 is a cross-sectional view of the case where the antireflection layer 30 a of the first embodiment is used as the antireflection layer 30 of the coloring structure 1. Fig.7 (a) is the figure which looked at the coloring structure 1 shown in FIG. 6 from the back surface side. FIG.7 (b) is sectional drawing which shows the cross-section in the (beta)-(beta) 'cross section of Fig.7 (a). In addition, in FIG. 6, illustration of the interference layer 40 is abbreviate | omitted for simplification, and in FIG. 7, illustration of the uneven | corrugated layer 20 and the interference layer 40 is abbreviate | omitted.

  The antireflective layer 30 a has a concavo-convex structure (second concavo-convex structure) 31 in which a plurality of convex portions are arranged on the opposite side to the base material 10. The vertical cross-sectional shape of the convex portion of the concavo-convex structure 31 may be a bell shape, a conical shape, an inverted funnel shape, a rectangular shape, a triangular prism, a polygonal prism, a cylinder, or any other shape. With such a shape, the refractive index in the third direction can be changed stepwise. As a result, it is possible to reduce that light transmitted without being reflected by the interference layer 40 and light incident from the back surface side of the color forming structure 1 are emitted again to the front surface side. That is, since it becomes difficult to visually recognize unnecessary light on the surface side of the coloring structure 1, the reflected light of the "specific wavelength range" reflected by the interference layer 40 can be visually recognized well.

  As shown in FIG. 7B, the concavo-convex structure 31 preferably has a height j1 in the film thickness direction of 10 nm or more and 500 nm or less. In addition, it is preferable that the structural period, that is, the arrangement period of the convex portions be a period of 10 nm or more and 1000 nm or less. The structural period is more preferably a sub-wavelength period which is equal to or less than the wavelength in the visible region. The uneven structure 31 may be formed by combining a plurality of different cycles, and in this case, the wavelength may be equal to or longer than the wavelength of the visible region. When each value is in this range, reflection at the interface can be effectively suppressed.

The structure period of the concavo-convex structure 31 is such that the ratio of the width of the period of the convex part to the width between the convex parts of the concavo-convex structure 31, ie, the width of the concave part, that is, the ratio of the width of the concave part to the convex part of the concavo-convex structure 31 is 0 It is easy to incline the refractive index in the cross-sectional direction as it is not less than 25 and not more than 0.75, which is preferable.
The arrangement pattern of the plurality of convex portions of the concavo-convex structure 31 may be a non-ordered arrangement, or may be a square arrangement or a hexagonal arrangement. Moreover, you may arrange in the island-like arrangement | sequence which combined these arrangement | sequences. It is preferable to design the projections of the concavo-convex structure 31 irregularly so as to change the size and height or to arrange them aperiodically. Thereby, reflection of incident light including various wavelength ranges can be effectively suppressed.

  It is preferable that the material of the uneven structure 31 has any of an ultraviolet ray curable resin, a thermosetting resin, and a thermoplastic resin as a main component. The plurality of convex portions of the concavo-convex structure 31 functions as the anti-reflection layer 30a. The antireflection layer 30a including the concavo-convex structure 31 may have a different layer configuration from the concavo-convex layer 20 via the base 10 as shown in FIG. 6, and the antireflection layer 30a and the concavo-convex layer 20 are integrated. May be In other words, the antireflective layer 30a may be formed using the same resin material as the uneven layer 20, or a different resin may be used. 1.1 or more and 2.0 or less are preferable, and, as for the refractive index of the material of the reflection preventing layer 30a, 1.4 or more and 1.6 or less are more preferable.

  Moreover, after forming the uneven | corrugated layer 20, you may form the reflection prevention layer 30a, and may form the uneven | corrugated layer 20 after forming the reflection prevention layer 30a. If the uneven layer 20 and the antireflective layer 30a can be formed simultaneously, the manufacturing cost can be reduced and the production capacity can be improved, which is preferable. Furthermore, in other words, the substrate 10 may or may not be present. That is, as shown in FIG. 8, a member having a concavo-convex structure having a convex portion 20 a having a first band-like shape 201 in a plan view on one surface, and a concavo-convex structure 31 on the other surface The interference layer 40 may be formed on the concavo-convex structure having the convex portion 20a.

Second Embodiment of Antireflection Layer
Next, a second embodiment of the antireflection layer 30 will be described with reference to FIGS. 9 to 12. Here, as shown in FIG. 9, the case where the concavo-convex layer 20 having the first strip shape 201 shown in FIG. 2 is provided as the concavo-convex layer will be described. The same applies to the case where the multi-step uneven layer 21 which is a pattern including the second strip shape 211 and the second strip shape 211 is provided.
FIG. 9 is a cross-sectional view of the color forming structure 1 when the reflection preventing layer 30 b of the second embodiment is used as the reflection preventing layer 30 of the color forming structure 1.
The anti-reflection layer 30 b has a concavo-convex structure 32 composed of a plurality of concavo-convex structures on the opposite side to the base 10 as shown in FIG. 9. Furthermore, a metal layer 50 having a surface shape that follows the unevenness of the uneven structure 32 is provided. The metal layer 50 is formed on the upper surface of the concave portion and the upper surface of the convex portion of the concavo-convex structure 32 in a cross sectional view.

FIG. 10A is a view of the coloring structure 1 shown in FIG. 9 as viewed from the side of the antireflection layer 30. FIG. 10B is a cross-sectional view showing a cross-sectional structure in the β-β ′ cross section of FIG. The interference layer 40 is omitted in FIG. 9 for the sake of simplicity. Moreover, in FIG. 10, illustration of the uneven | corrugated layer 20, the interference layer 40, and the metal layer 50 is abbreviate | omitted. That is, as shown in FIG. 11, FIG. 10 shows the concavo-convex structure 32 in the state where the metal layer 50 is not formed in the coloring structure 1 (FIG. 9).
The structural period P1 of the convex portion of the concavo-convex structure 32 is preferably a sub-wavelength period equal to or less than the wavelength of the visible region. The height j2 of the convex portion of the concavo-convex structure 31 preferably has a thickness of 10 nm or more and 200 nm or less. Plasmon resonance is easily expressed when each value is in this range.

The concavo-convex structure 32 may be a non-ordered array, or may be a square array or a hexagonal array. Moreover, you may arrange in the island-like arrangement | sequence which combined these arrangement | sequences. A non-ordered arrangement is preferred because it is easier to reduce interference fringes.
Also in this case, the concavo-convex layer 20 and the antireflective layer 30 may be integrated. The antireflective layer 30 may be formed after the uneven layer 20 is formed, and conversely, the uneven layer 20 may be formed after the antireflective layer 30 is formed. If the uneven layer 20 and the antireflective layer 30 can be formed simultaneously, the manufacturing cost can be reduced and the production capacity can be improved, which is preferable. That is, the base 10, the concavo-convex layer 20, and the anti-reflection layer 30 may be continuous configurations of the same material, or may be composed of different materials. Furthermore, in other words, the substrate 10 may or may not be present.

In addition, as shown in FIG. 12, it has a concavo-convex structure having a convex portion 21 a on one surface, which is a pattern including a first strip shape 201 and a second strip shape 211 in plan view, and the other surface. The color forming structure 1 is formed by forming the interference layer 40 on the concavo-convex structure having the convex portion 21 a and the metal layer 50 on the concavo-convex structure 32. May be configured. In FIG. 12, the interference layer 40 and the metal layer 50 are omitted for the sake of simplicity.
The shape of the concave portion and the convex portion of the plurality of concavo-convex structures 32 is not limited to a rectangle, and may be rounded, or may be a triangular prism, a cylinder, or the like.
The structure cycle of the concavo-convex structure 32 can efficiently cause plasmon resonance when the ratio of the widths of the concavo-convex structure 32 is 0.25 or more and 0.75 or less, and can exhibit a color with high lightness.

<Metal layer>
As shown in FIG. 9, the metal layer 50 has a structure in which a metal is disposed on the top surface of the uneven structure 32. When light is irradiated from the surface side of the color forming structure 1, light passes through the uneven layer 20, the base 10, the uneven structure 32 of the antireflective layer 30b, and the metal layer 50 in this order. When the metal layer is provided on the antireflective layer not having the concavo-convex structure, the wavelength of light and the vibration direction of the free electron of the metal are different, so strong reflected light is generated at the interface between the metal layer and the antireflective layer. Even if the interference layer 40 is formed, it will be white light. When the metal layer 50 is provided on the upper surface of the convex part of the concavo-convex structure 32 and the upper surface of the concave part, plasmon absorption occurs at the interface between the concavo-convex structure 32 and the metal layer 50 to reflect a specific wavelength region and not only regular reflection but also anisotropy. Light with sexual scattering is reflected.

The light passing through the concavo-convex structure 32 and the metal layer 50 causes the plasmon abnormal transmission phenomenon and is emitted. Therefore, three lights of light reflected from the interference layer 40, light reflected from the metal layer 50, and transmitted light Is different. Therefore, it is preferably used, for example, for a display that is difficult to forge and has high security.
In addition, when the color forming structure 1 is attached to or adhered to another display, the specific surface area is increased by the uneven structure 32 and the metal layer 50, and good adhesion is exhibited.
It is preferable that the metal layer 50 includes one or more types of metal or metal alloy having a refractive index of 0.2 or more and 6.0 or less, because the intensity of light reflected by the metal layer 50 is increased.
In addition, when the extinction coefficient of the metal layer 50 in the visible light region is 2.0 or more and 6.0 or less, the light to be absorbed becomes small and the light is efficiently emitted as the reflected light, which is preferable.

<Third form of antireflective layer>
Next, the third embodiment of the antireflective layer 30 will be described. The antireflection layer 30 in the third embodiment may be used in combination with the antireflection layer 30a in the first embodiment and the antireflection layer 30b in the second embodiment.
The antireflective layer 30 in the third embodiment has a configuration in which a black pigment is contained in a resin. According to this configuration, since the antireflective layer 30 can absorb light in a wide wavelength range in the visible region, the difference in the wavelength range of transmitted light according to the configuration of the interference layer 40 in the configuration where incident light is light in the visible region The transmitted light can be suitably absorbed regardless of
A resin layer containing a black pigment may be provided separately from the substrate 10, or the substrate 10 may contain a black pigment to form the antireflective layer 30. Moreover, a black pigment may be contained in the uneven structure 31 or 32, and these effects may be used together.

In the configuration including the black pigment and the resin, a thermoplastic resin may be used as the resin. As a thermoplastic resin, the thermoplastic resin illustrated as a material of the below-mentioned uneven layer 20 and the base material 10 is mentioned, for example.
In addition, black pigments include black inorganic pigments such as carbon black, titanium black, black iron oxide, black complex oxides and the like. Furthermore, other light absorbers made of materials that absorb light in the visible region may be included.
In the case of using the multi-step uneven layer 21 as the uneven layer in the color forming structure 1 including the first to third antireflective layers of the first to third embodiments as the anti-reflective layer 30, as shown in FIG. As shown in FIG. 14 (in the case of including the antireflective layer 30b), the interference layer 40 may have a multilayer structure in which high refractive index layers 40a and low refractive index layers 40b are alternately stacked. Alternatively, a single layer structure may be used.

[Method for producing colored structure]
Next, the material of each layer which comprises the coloring structure 1, and the manufacturing method of the coloring structure 1 are demonstrated.
The concavo-convex layer 20 having the concavo-convex structure is made of a material having optical transparency to light in the visible region, that is, a material transparent to light in the visible region. Although not particularly limited thereto, it is preferable to use a photocurable resin, a thermoplastic resin, a thermosetting resin or the like. The thermoplastic resins that can be used include, but are not limited to, acrylic resins, polyester resins, cellulose resins, and vinyl resins. Thermosetting resins that can be used include, but are not limited to, urethane resins obtained by the reaction of acrylic polyols or polyester polyols having reactive hydroxyl groups with polyisocyanates, melamine resins, epoxy resins, phenol resins, etc. It is not a thing.

The substrate 10 is preferably a material having optical transparency to light in the visible region. For example, as the substrate 10, a film made of a resin such as polyethylene terephthalate, polycarbonate, polyethylene naphthalate, polyethylene, polypropylene and cycloolefin copolymer is used. In addition, inorganic substances such as glass, quartz, quartz, silicon wafer, and metals can be used as the base material.
The concavo-convex structure of the relatively hard substrate surface such as synthetic quartz or silicon wafer is formed, for example, using known micro processing technology such as lithography for irradiating light or charged particle beam or dry etching.

When the concavo-convex layer 20 is formed on the base material 10, functions such as mechanical strength such as tensile strength and moldability can be given, so it has flexibility and high utilization. For example, it is possible to apply a manufacturing method suitable for mass production such as roll-to-roll method.
As a method of forming the concavo-convex layers 20 and 21 and the concavo-convex structures 31 and 32 of the anti-reflection layer 30, a nanoimprinting method or the like is used. For example, in the case of forming the concavo-convex structure of the concavo-convex layer 21 by the photo nanoimprinting method, first, a mold which is an intaglio having inverted concavities and convexities of the concavities and convexities to be formed is required.

  As a method of forming the concavo-convex structures 20 and 21 and the concavo-convex structures 31 and 32 of the anti-reflection layer 30, the substrate 10 is superimposed on the surface of the coating layer made of a photocurable resin, and the coating layer and the mold are mutually pressed. Light is emitted from the substrate 10 side or the mold side in the state as it is. Subsequently, the mold is released from the cured photocurable resin and the substrate 10. Thereby, the unevenness of the mold is transferred to the photocurable resin, and the unevenness layers 20 and 21 having the unevenness on the surface are formed. Next, on the surface of the substrate 10 opposite to the surface on which the concavo-convex layers 20 and 21 are formed, the substrate 10 is superimposed on the surface of the coating layer made of a photocurable resin, and the coating layer and the mold The light is irradiated from the substrate 10 side or the mold side in a state where the two are pressed to each other. Subsequently, the mold is released from the cured photocurable resin and the substrate 10. As a result, the anti-reflection layer 30 including the concavo-convex layers 20 and 21 on one surface of the base 10 and the concavo-convex structures 31 and 32 on the other surface is formed. The photocurable resin may be applied to the surface of the substrate 10, and light irradiation may be performed in a state where the mold is pressed against the coating layer on the substrate 10.

  The order of formation of the antireflection layer 30 provided with the concavo-convex layers 20 and 21 and the concavo-convex structures 31 and 32 is not limited to the above, and may be replaced. Moreover, the anti-reflection layer 30 provided with the uneven | corrugated layers 20 and 21 and the uneven | corrugated structures 31 and 32 may be formed simultaneously. It is possible to simultaneously form the antireflection layer 30 having the concavo-convex layers 20 and 21 on one surface of the layer made of a photocurable resin, a thermosetting resin and a thermoplastic resin and the concavo-convex structures 31 and 32 on the other surface. Thus, the cost can be reduced in terms of materials and equipment, and an inexpensive display can be provided.

The coating method of the curable resin is not particularly limited, and 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 may be used.
The mold is made of, for example, synthetic quartz or silicon, and is formed using a known fine processing technique such as lithography for irradiating light or charged particle beam or dry etching.
Further, instead of the photo nanoimprinting method, a thermal nanoimprinting method or a normal temperature nanoimprinting method may be used. In this case, as a resin used for the antireflective layer 30 including the concavo-convex layers 20 and 21 and the concavo-convex structures 31 and 32, Resins according to the manufacturing method, such as thermoplastic resins and thermosetting resins, are used.

  When the step of forming the concavo-convex layers 20 and 21 and the antireflection layer 30 is a first step, a second step of forming the interference layer 40 on the concavo-convex layers 20 and 21 after the first step The third step of forming the metal layer 50 on the uneven structure 32 is performed. The interference layer 40 is formed to interfere in the “specific wavelength range” of the reflected light in the interference layer 40. The metal layer 50 is formed such that plasmon resonance is induced in a “specific wavelength range” of incident incident light.

The compounds used for the interference layer 40 include Nb ₂ O ₅ , Ta ₂ O ₅ , Al ₂ O ₃ , Fe ₂ O ₃ , HfO ₂ , MgO, ZrO, SnO ₂ , Sb ₂ O ₃ , CeO ₃ , WO ₃ Inorganic dielectric materials such as PbO, In ₂ O ₃ , CdO, BaTiO ₃ , ITO, LiF, BaF ₂ , CaF ₂ , MgF ₂ , AlF ₃ , CeF ₃ , ZnS, PbCl ₂ , acrylic resins, phenolic resins Inorganic-organic hybrid materials in which an inorganic material is dispersed in an organic resin material such as epoxy resin may be used.
More preferably, the high refractive index layer is provided with TiO ₂ and the low refractive index layer is provided with SiO ₂ .

When the interference layer 40 is a multilayer film, multilayer interference is achieved by alternately laminating the high refractive index layer 40 a and the low refractive index layer 40 b. The order may be reversed, and it is also possible to reduce the number of stacked layers if desired color development can be obtained. Each of the high refractive index layer 40 a and the low refractive index layer 40 b is made of a material having optical transparency to light in the visible region, ie, a material transparent to light in the visible region.
The material of these layers is not limited as long as the refractive index of the high refractive index layer 40a is higher than the refractive index of the low refractive index layer 40b, but the refractive index of the high refractive index layer 40a and the low refractive index layer 40b As the difference in rate is 0.6 or more and 2.2 or less, high-intensity reflected light can be obtained with a small number of laminations.

Each layer of the high refractive index layer 40a and the low refractive index layer 40b made of such an inorganic material is formed using a known thin film forming technique such as sputtering, vacuum evaporation, or atomic layer deposition. In addition, each of the high refractive index layer 40a and the low refractive index layer 40b may be made of an organic material, and in this case, the formation of the high refractive index layer 40a and the low refractive index layer 40b is known The technology of the above may be used.
The film thickness of each of the high refractive index layer 40 a and the low refractive index layer 40 b may be designed using a transfer matrix method or the like according to a desired color to be colored by the color forming structure 1. The film thickness of the high refractive index layer and the low refractive index layer is preferably about 30 nm or more and 300 nm or less.
The number of layers in the interference layer 40 in FIG. 5 and the order of stacking are not limited to this. In the interference layer 40, the refractive indexes of layers adjacent to each other are different from each other, and the reflectance of light in a specific wavelength range among incident light incident on the interference layer 40 is higher than the reflectance in other wavelength ranges. It should just be comprised.

  Although the material which comprises the metal layer 50 will not be specifically limited if it is a compound which reflects incident light, Preferably it is a metal or a metal alloy. If necessary, the metal or metal alloy or composite constituting the metal layer 50 may be stacked. Even if light is incident on the concavo-convex structure 32, strong regular reflected light and scattered light can be obtained, so a metal or metal alloy having a refractive index of 0.2 or more and 6.0 or less is preferable. An extinction coefficient of 2.0 or more and 6.0 or less is preferable because light absorption can be reduced. Specifically, when one or more of Au, Ag, Cu, Al, Zn, Ni, Cr, Ge, Mo, Ga, Ta, W, In, Sn, or any metal or alloy or composite thereof is provided. The light incident on the concavo-convex structure 32 is preferable because plasmon resonance occurs. More preferably, it is Ag and Al.

The metal layer 50 is formed using a known thin film forming technique such as sputtering, vacuum evaporation, or atomic layer deposition. The metal layer 50 may be configured to contain an organic material, and a known technique such as self-assembly may be used.
In order to cause plasmon resonance in the metal layer 50, the film thickness of the metal layer 50 is preferably about 5 nm or more and 500 nm or less. Further, the film thickness is more preferably 5 nm or more and 200 nm or less because the transmittance can be maintained while maintaining an arbitrary reflectance.

[Example of application of coloring structure]
A specific application example of the coloring structure 1 described above will be described. In the application example described below, the coloring structure 1 having the concavo-convex layer 20 constituting the first strip shape 201, the concavo-convex layer 21 constituting the pattern including the first strip shape 201 and the second strip shape 211. The interference layer 40 is formed on the color forming structure 1 having concavo-convex layers 20 or 21 and on the concavo-convex structure 32 of the color forming structure 1 on which the antireflection layer 30 a or 30 b is formed. Any of the color forming structures 1 in which the metal layer 50 is formed is applicable.

<Display body>
An application example of the color forming structure 1 is a form in which the color forming structure 1 is used for a display. The display body may be used for the purpose of enhancing the difficulty of counterfeiting the article, may be used for the purpose of enhancing the design of the article, or may be used for these purposes.
For the purpose of enhancing the difficulty of counterfeiting goods, the display body may be, for example, authentication documents such as passports and licenses, securities such as gift certificates and checks, cards such as credit cards and cash cards, bills, etc. It is pasted. Also, for the purpose of enhancing the design of the article, the display body may be, for example, an accessory worn by a watch, an article carried by a user such as a cell phone or a mobile, or an article placed like furniture or household appliances. , Walls and doors, signs, and structures such as interiors and exteriors of automobiles.

In addition to surface reflectance, back surface reflection, and transmission, when a display including a plurality of display elements and configured from the coloring structure 1 according to one aspect is used as a highly security application such as a credit card, a cash card, or a bill. A multicolored display of three colors can be provided, and it is possible to provide a display body that is not easily forged.
When a display body comprising a plurality of display elements and configured from the color forming structure 1 according to one aspect is used as a display board for a watch, it can be used more than a natural product made of pearl, white butterfly clam, or abalone. In addition to reflectance and transmittance, patterns and film thicknesses can be made uniform and in-plane on a lot basis, so high-quality patterns and color tones can be expressed in various ways, and display panels with high designability can be provided. .

In addition, the display body using the color forming structure 1 according to an aspect of the present invention is preferably transparent because it also has high transmittance while maintaining high reflectance of a display body.
More preferably, it is a display board for a watch provided with a self-power generation function such as a solar cell, and since it can secure arbitrary transmittance to solar radiation while concealing the crosshairs of the insulating band, it is charged It becomes possible. The display using the color forming structure according to one embodiment does not require an absorption layer, but the black / dark blue solar cell functions as an absorption layer to increase scattered light and provide a high-grade display panel. .

  When a display comprising a plurality of display elements and configured from the coloring structure 1 of one embodiment is used for parts such as outdoor / internal installations, moving objects, vehicles, etc. where weather resistance is required, paints and inks It is preferable because it is hardly discolored by sunlight. More preferably, it is suitably used for automobile parts in general, such as the interior of automobile parts from the viewpoint that fingerprints and the like are less noticeable, and the exterior of car parts from the viewpoint that the self-cleaning action when raining works.

  As shown in FIG. 15, the display 70 has a front surface 70F and a back surface 70R which is a surface opposite to the front surface 70F. The display 70 includes a first display area 71 and a second display area 72, and the display content can be viewed on both the front surface 70F and the back surface 70R. The first display area 71 is an area in which the plurality of first pixels 71A are disposed, and the second display area 72 is an area in which the plurality of second pixels 72B are disposed. In other words, the first display area 71 is composed of a set of a plurality of first pixels 71A, and the second display area 72 is composed of a set of a plurality of second pixels 72B.

  The configuration of the coloring structure 1 is applied to each of the first pixel 71A and the second pixel 72B, and the first pixel 71A and the second pixel 72B exhibit colors with different hues. That is, as viewed from the direction facing the surface 70F of the display 70, colors of different hues are visually recognized in the first display area 71 and the second display area 72. Further, as viewed from the direction opposite to the back surface 70R, colors of different hues in the first display area 71 and the second display area 72 are visually recognized. Furthermore, the color of a different hue is visually recognized by the light passing through each of the first display area 71 and the second display area 72.

Each of the first display area 71 and the second display area 72 represents a character, a symbol, a figure, a pattern, a pattern, a background thereof, etc. by these areas alone or by a combination of two or more of these areas. .
In the display 70, an interference layer is laminated around the first and second display areas 71, 72, etc., in an area having a configuration different from that of the color forming structure 1, for example, a base having a flat surface. It may have a region having the above structure, a region having a structure in which a metal layer is stacked on a base material, and the like.

  In the first pixel 71A and the second pixel 72B, the heights h1 of the convex portions 20a constituting the first strip shape 201 included in the uneven layer 20 or 21 of the coloring structure 1 are different from each other. On the other hand, in the first pixel 71A and the second pixel 72B, the configuration of the interference layer 40 is common, that is, for example, the material and thickness of the high refractive index layer 40a, the material and thickness of the low refractive index layer 40b, And the number of layers of these layers is common. The first pixel 71A and the second pixel 72B have different hue colors because the height h1 of the convex portion 20a constituting the first strip shape 201 is different between the first pixel 71A and the second pixel 72B. Take on. The height h1 of the convex portion 20a constituting the first strip shape 201 in the first pixel 71A and the second pixel 72B may be set according to the desired hue of each pixel 71A, 72B.

Here, the difference between the height h1 of the convex portion 20a constituting the first strip shape 201 of the first pixel 71A and the height h1 of the convex portion 20a constituting the first strip shape 201 of the second pixel 72B. Is larger, the difference between the hue exhibited by the first pixel 71A and the hue exhibited by the second pixel 72B is increased, and the difference in the hue is more easily recognized by human eyes.
For example, in the case where the peak wavelength of the reflected light from the interference layer 40 in the case where the interference layer 40 is stacked on a flat surface is 500 nm and it is desired to cause the first pixel 71A and the second pixel 72B to make green color, It is preferable to set the height h1 of the convex portion 20a constituting the strip shape 201 to about 100 nm, and when it is desired to develop red color by the first pixel 71A and the second pixel 72B, the first strip shape 201 is configured. It is preferable to set the height h1 of the convex portion 20a to about 200 nm.
Further, as shown in FIG. 4, also in the color forming structure 1 having the multi-level concavo-convex layer 21, the first pixel 71 A, by adjusting the height h 1 of the convex portion 20 a constituting the first strip shape 201. The hue of the second pixel 72B can be adjusted.

  The pattern of the first strip shape 201, that is, the length in the first direction and the second direction of the first strip shape 201 is set, for example, for each of the first pixels 71A and for each of the second pixels 72B. That is, the average value and the standard deviation of the lengths d1 and d2 of the first direction and the second direction of the strip pattern Po constituting the first strip shape 201 are set for each of the first pixel 71A and the second pixel 72B. . The pattern of the first strip shape 201 may be different for each of the first pixels 71A and the second pixels 72B, or may match each other. The sizes of the first pixel 71A and the second pixel 72B may be set in accordance with the desired resolution of the images displayed in the first and second display areas 71, 72. In order to display an image with higher accuracy, it is preferable that one side of the first pixel 71A and the second pixel 72B be 10 μm or more.

In the display using the color forming structure 1 in FIG. 14, the colors viewed are different when observed from the interference layer 40 side and when observed from the metal layer 50 side, so various expressions are made in the display 70. Can.
In the display body 70, the base material 10 is continuous between the first pixel 71A and the second pixel 72B, that is, the first pixel 71A and the second pixel 72B are one common base material 10 have.
The concavo-convex structure in the base material 10 corresponds to, for example, each of a portion corresponding to the first display region 71 in which the first pixel 71A is positioned and a portion corresponding to the second display region 72 in which the second pixel 72B is positioned. , And lithography or dry etching. In order to change the height h1 of the first strip shape 201, the etching time may be changed.

When the first display area 71 and the second display area 72 are in contact with each other, the interference layer 40 and the metal layer 50 are continuously formed between the first pixel 71A and the second pixel 72B. That is, the interference layer 40 is manufactured in the same process for the first pixel 71A and the second pixel 72B, and similarly, the metal layer 50 is manufactured in the same process.
Note that making the first pixel 71A and the second pixel 72B different in hue means that the first pixel 71A and the second pixel 72B have different materials such as the material and thickness of the layer that constitutes the interference layer 40. It is also possible by However, if the configuration of the interference layer 40 is different for each of the display areas 71 and 72, it is necessary to repeat the masking of the area and the film formation of the high refractive index layer 40a and the low refractive index layer 40b for each of the display areas 71 and 72. This complicates the manufacturing process. As a result, an increase in manufacturing cost and a decrease in yield are caused. In addition, since it is difficult to mask a minute area, there is a limit to the formation of a fine image.

  On the other hand, with the configuration of the display 70 described above, it is possible to simultaneously form the interference layer 40 for the part corresponding to the first display area 71 and the part corresponding to the second display area 72. The load required to manufacture the display 70 is reduced. In addition, since it is easy to make the height h1 of the convex portion 20a constituting the first strip shape 201 different for every minute area as compared with the masking to the minute area, the display areas 71 and 72 are used. It can also be made smaller to produce a finer image.

  As another method of making the hue different, the hue can be made different by changing the arrangement of the concavo-convex layer 21 with the same configuration of the metal layer 50 between the first pixel 71A and the second pixel 72B. That is, the uneven layer of the color forming structure 1 in the first pixel 71A, for example, the extending direction of the convex part 21a of the uneven layer 21, and the uneven layer of the coloring structure 1 in the second pixel 72B, for example, the convex 21a of the uneven layer 21 The first pixel 71A and the second pixel 71B are arranged such that the extending direction is different from the extending direction. For example, as shown in FIG. 15, in the display area 71, the convex portion 21a is arranged to extend along the second direction in the color forming structure 1 in each first pixel 71A, and in the display area 72, in each second pixel 72B. In the coloring structure 1, the convex portion 21a is arranged to extend along the first direction.

As a result, the directions of scattered light are different, so that the brightness is different from that of the adjacent pixels, and as a result, they appear as different hues.
The direction in which the convex portion 21a extends is not limited to the first direction or the second direction, and can be arranged to extend in any direction. For example, in FIG. 15, the convex portion 21a may be arranged such that the angle formed by the extending direction of the convex portion 21a of the color forming structure 1 and the second direction in the first pixel 71A is, for example, 45 °. As described above, the convex portion 21a is extended by arranging the convex portion 21a such that the angle between the extending direction of the convex portion 21a and the first direction or the second direction is 0 ° to 90 °. Since expression different from that in the case where the direction is the first direction or the second direction can be performed, more colorful expression can be performed.

  Further, by making the configuration of the metal layer 50 the same between the first pixel 71A and the second pixel 72B and making the heights j1 or j2 of the convex portions of the concavo-convex structure 31 or 32 of the anti-reflection layer 30 different, reflection is made. In addition, it is possible to make the transmission hues different. Further, in the concavo-convex structure 31 or 32 of the anti-reflection layer 30, the hues of reflection and transmission may be different by changing the ratio of the width of the period of the convex to the width of the concave and the ratio of the width of the metal layer to the concave. It is possible to

  When the coloring structure 1 having the concavo-convex layer 20 stacked on the substrate 10 is applied to the configuration of the first pixel 71A and the second pixel 72B, the concavo-convex structure of the concavo-convex layer 20 is, for example, Formed as. That is, a mold in which the height of the unevenness is changed between the portion corresponding to the first display region 71 and the portion corresponding to the second display region 72 using the nanoimprint method is used. The concavo-convex structure of the concavo-convex layer 20 of 72 B is simultaneously formed.

  Such a mold may be formed by performing lithography or dry etching for each portion corresponding to the first display area 71 and the second display area 72. For example, according to the following method, formation of a mold is possible more simply. That is, the dose of the charged particle beam to be irradiated to the resist used in charged particle beam lithography is changed for each of the first display area 71 and the second display area 72, and the unevenness of the desired height is obtained for each display area 71, 72. The development time is adjusted to form a resist pattern. After a metal layer of, for example, nickel is formed by electroforming on the surface of the resist pattern, the resist is dissolved to obtain a nickel mold.

  The number of display areas included in the display body 70, that is, the number of display areas in which pixels composed of the color forming structure 1 are arranged and exhibit colors of different hues is not particularly limited, and the number of display areas is There may be one, or three or more. Furthermore, the display area may include a display element formed of the coloring structure 1, and the display element is not limited to the pixel which is the minimum unit of repetition for forming a raster image, and forms a vector image. It may be a region connecting anchors for

When the display 70 comprising a plurality of display elements and configured from the coloring structure 1 is used for the dial of a watch, it has high designability and can be arbitrarily transmitted to lamps such as LEDs and to solar radiation. Since it is possible to ensure brightness and to display brightly in the dark and to store emitted light by the solar cell, it is preferable.
When a display 70 comprising a plurality of display elements and configured from the color forming structure 1 is used for an automobile part, it may be used as an exterior and interior part having high designability and high weather resistance and antifouling properties. It is more preferable because it can be done.

When the coloring structure 1 includes the concavo-convex layer 20, a diffusion effect of the reflected light is obtained by the convex portion 20a constituting the first strip shape 201, and light of a specific wavelength range as the reflected light from the interference layer 40. Is observed at a wide angle.
When the coloring structure 1 includes the uneven layer 21 in multiple stages, the diffusion effect and the diffraction effect of the reflected light are obtained by the convex portions 21 a of the uneven layer 21, and the reflected light from the interference layer 40 has a specific wavelength range. The light can be observed at a wide viewing angle, and by increasing the intensity of the reflected light, a bright and glossy color can be recognized.

  When the coloring structure 1 includes the multi-step concavo-convex layer 21, the plurality of second strip shapes 211 are arranged to extend in the second direction and are arranged along the first direction and the second direction. , At least one of the average value and the standard deviation of the arrangement intervals of the second strip shape 211 is different by the arrangement interval along the first direction and the arrangement interval along the second direction, The convex corresponding to the second strip shape 211 according to the difference between the influence of the height h1 of the convex portion 20a corresponding to the strip shape 201 in the first direction and the influence in the second direction of the scattering effect of the reflected light. The diffraction effect of the reflected light can be adjusted by the height h2 of the portion 21b. In the configuration in which each of the average value of the arrangement interval in the first direction and the average value of the arrangement interval in the second direction in the second strip shape 211 is 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 described above.

  In the display body 70 which is configured of the color forming structure 1 and in which the color forming structure 1 includes the reflection preventing layer 30 b including the metal layer 50, the metal layer 50 is configured of the first pixel 71A and the second pixel 72B. In the configuration in which the material and the film thickness are the same and the heights of the convex portions in the concavo-convex layers 20 and 21 are different, colors of different hues are visually recognized in the area where the first pixel 71A is located and the area where the second pixel 72B is located. Be done. Then, since the configuration of the metal layer 50 is the same in the first pixel 71A and the second pixel 72B, there is no need to perform the step of forming the metal layer 50 for each region where each pixel 71A, 72B is located. The display 70 having the pixels 71A and 72B exhibiting different hues can be formed by a simple manufacturing process.

  According to the manufacturing method in which the concavo-convex structure of the concavo-convex layers 20 and 21 is formed using the nanoimprinting method, a fine concavo-convex structure can be suitably and easily formed. And if it is a manufacturing method in which an optical nanoimprinting method or a thermal nanoimprinting method is used as a nanoimprinting method, formation of the concavo-convex structure by the nanoimprinting method is suitably and easily realized.

  The pixels included in the display body 70 include pixels in which the extending direction of the concavo-convex structure in the concavo-convex layers 20 and 21 in a plan view, that is, the extending directions of the first band shape 201 and the second band shape 211 are different. Good. Specifically, the first strip shape 201 in any pixel, the second direction which is the extension direction of the second strip shape 211, and the first strip shape 201 in a pixel different from this pixel, a second direction The second direction which is a direction in which the strip shape 211 extends is a different direction, and for example, the directions may be orthogonal to each other. According to such a configuration, it is possible to change the direction in which the reflected light from the interference layer 40 is diffused by the pixel, and it is possible to represent a more versatile image.

  In addition, since the interference layer 40 is formed somewhat on the side surfaces of the projections in the concavo-convex layers 20 and 21, the width of the projections of the concavo-convex structure in the interference layer 40 is more Also spread slightly. In the portions where pixels with mutually different directions of extension of the concavo-convex structure are adjacent to each other, the above-described spread portions in the interference layer 40 are connected between the convex portions with different extension directions, and the concavo-convex structure in the interference layer 40 is broken If it occurs, it is difficult to obtain desired color development from each pixel in the desired direction. Therefore, it is preferable that the area | region in which the unevenness | corrugation is not formed in the uneven | corrugated layers 20 and 21 is provided between the pixels from which the extending direction of uneven structure differs mutually. That is, between the first band-like shapes 201 and between the convex portions formed of the first band-like shape 201 and the second band-like shape 211 superimposed thereon, the first band-like shape 201 and the first band-like shape 201 It is preferable that a region where neither of the two strip shapes 211 is formed be provided, and when the interference layer 40 is formed on the concavo-convex layers 20 and 21, a gap is formed between the interference layers 40, It is preferable that the interference layer 40 be provided with a region capable of forming a concavo-convex structure similar to the concavo-convex structure of the concavo-convex layers 20 and 21.

  Further, even between the pixels having the concavo-convex structure in which the concavo-convex structure extends in the same direction, a region in which the concavities and convexities are not formed may be provided in the concavo-convex layers 20 and 21. The collapse of the concavo-convex structure due to the spread is suppressed at the edge of the pixel, and desired color development can be easily obtained from the whole of each pixel. The width of the region provided between the pixels and in which the unevenness is not formed is preferably, for example, 1/2 or more of the film thickness of the interference layer 40.

  The convex part which comprises the uneven structure of the uneven layers 20 and 21 may have the structure to which the width | variety of a 1st direction becomes small gradually toward a top part from a base. According to such a configuration, the interference layer 40 is easily formed on the convex portion. In this case, the first direction length d1 of the first strip shape 201 and the length d3 of the second strip shape 211 are the first strip shape 201 or the first strip shape 201 and the second strip shape It is specified by the pattern which the bottom of the convex part which is formed to overlap with the surface of the convex part 211 forms.

  As described above, the color forming structure 1 according to the embodiment of the present invention has a surface shape following the concavo-convex structure of the concavo-convex layer 20 on the concavo-convex layer 20 which transmits light in the visible region and has the concavo-convex structure. An interference layer 40 is provided, and further, an antireflective layer 30 that absorbs at least a part of light transmitted through the interference layer 40 is provided on the opposite side of the uneven layer 20 from the interference layer 40. Furthermore, a plurality of first band-like shapes 201 forming convex portions are provided in the uneven layer 20, and the shape of the first band-like shapes 201 is a shape combining one or more band-like patterns Po. The width of the strip pattern Po along the first direction is smaller than the wavelength of the incident light, and the standard deviation of the length along the direction orthogonal to the first direction is calculated from the standard deviation of the width of the strip pattern Po Also try to get bigger.

Therefore, thin film interference or multilayer interference occurs due to the interference layer 40, and the effect of reversing the phase of the emitted light is exhibited. The light of the specific wavelength reflected by the interference layer 40 having a surface shape following the uneven structure of the uneven layer 20 generates not only regular reflected light but also anisotropic scattered light. As a result, it is possible to recognize light in the same wavelength range at a wide angle, that is, as the same color. In the case where the multilayer film layer is formed on a flat surface as in the prior art, the intensity of the specularly reflected light is very large, and the color changes depending on the angle to be observed. According to the above, it is possible to widen the viewing angle.
In the case where the reflection preventing layer 30 is not provided, the light not reflected by the interference layer 40 and transmitted through the side opposite to the interference layer 40 (the back side) is used for the specific wavelength range of the interference layer 40. Although the visibility of the color due to the reflected light is lowered, in the color forming structure 1 according to the embodiment of the present invention, since the anti-reflection layer 30 is provided, unnecessary light can be absorbed, and as a result, Reflected light in the wavelength range can be visually recognized well.

  At this time, the antireflection layer 30 is provided on the opposite side to the concavo-convex layer 20 across the substrate 10, and the height in the film thickness direction of the concavo-convex structure 31 or 32 included in the antireflection layer 30 is 10 nm to 500 nm. Forming the uneven structure 31 or 32 into an array having no order or any one of the square arrangement and the hexagonal arrangement or a combination thereof, and further, the structure period of the uneven structure 31 or 32 is 10 nm or more and 1000 nm or less The ratio of the width of the period of the unevenness to the recess of the uneven structure 31 or 32 may be 0.25 or more and 0.75 or less.

  By forming the anti-reflection layer 30 in a concavo-convex structure having a plurality of convex portions having a height of 10 nm to 500 nm as described above, a low reflection effect can be obtained by a so-called moth-eye structure. As a result, unnecessary light can be suppressed, and the reflected light in the specific wavelength range reflected by the interference layer 40 can be favorably viewed. Further, when the antireflective layer 30 side of the color forming structure 1 is bonded or adhered to another display body, the surface area to be in contact is increased and the adhesiveness is improved since the plurality of uneven structures 31 or 32 are provided. .

  In addition, a concavo-convex structure 31 or 32 is provided on the surface opposite to the concavo-convex layer 20 or 21, and the height of the concavo-convex structure 31 or 32 in the film thickness direction is 10 nm or more and 200 nm or less. Forming an irregular array or a square array, an hexagonal array, or an island array combining these, and further providing a metal layer 50 on the upper surface of the concave and convex portions of the concave and convex structures 31 and 32; Assuming that the structural period of the metal layer 50 and the metal layer 50 is a sub-wavelength period equal to or less than the wavelength of the visible region, the ratio of the width of the period of the unevenness to the recess of the uneven structure 31, 32 and the width of the metal layer to the recess of the metal layer 50 The ratio may be 0.25 or more and 0.75 or less.

With such a configuration, a plasmon resonance phenomenon occurs, that is, light transmitted through the interference layer 40 is transmitted through the antireflective layer 30 by the plasmon resonance phenomenon, and thus unnecessary light is reflected to the interference layer 40 side. Can be reduced. As a result, the reflected light of the specific wavelength range reflected by the interference layer 40 can be visually recognized well. Furthermore, when the coloring structure 1 is observed from the anti-reflection layer 30 side which is the back surface side, a wavelength range different from the interference layer 40 side which is the front surface side can be observed by the plasmon resonance phenomenon. Therefore, it is possible to realize the color forming structure 1 that exhibits three colors in the front surface reflected light, the back surface reflected light, and the transmitted light.
In addition, when the antireflective layer 30 side of the color forming structure 1 is bonded or adhered to another display 70, since the uneven structure having a plurality of convex portions is provided, the surface area to be in contact is increased, and the adhesion is improved. Improve.

Further, in the color forming structure 1, the material forming the metal layer 50 is a metal, a metal alloy, and a metal composite material having a refractive index of 0.2 to 6.0 in the visible light region, and a extinction in the visible light region. It may be one or more selected from metals, metal alloys, and metal composite materials having an extinction coefficient of 2.0 or more and 6.0 or less.
By doing this, the absorptivity of light incident when observed from the back surface side is reduced, and efficient reflection can be performed.
Further, in the color forming structure 1, the antireflective layer 30 may contain a black pigment.
By doing so, it is possible to reduce the reflection of unnecessary light to the interference layer 40 side. As a result, the reflected light of the specific wavelength range reflected by the interference layer 40 can be visually recognized well.

Further, in the color forming structure 1, the uneven layer 21 has a multistage shape in which a second band-like shape 211 composed of a plurality of convex portions is stacked on the first band-like shape 201, A plurality of strip shapes 211 are provided in plan view, and the second strip shape 211 has a width along the first direction and a length along the second direction, and the second strip shape 211 The arrangement interval in one direction is not constant, and the average value of the arrangement intervals is made to be 1/2 or more of the minimum wavelength in the wavelength range of the incident light.
Therefore, the convex portion of the concavo-convex structure consisting of the first strip shape 201 and the second strip shape 211 obtains the diffusion effect and the diffraction effect of the reflected light, and the reflected light in a wide wavelength range from the color forming structure 1 Since the light is emitted and the scattered light is emitted in a wide angle range, a bright and glossy color can be visually recognized. In addition, even if the observation angle is changed, it is recognized as the same color, and the viewing angle can be expanded.

Further, in the color forming structure 1, one of the materials constituting the interference layer 40 is one selected from among inorganic compounds having a refractive index of 1.3 or more and 4.0 or less, or compounds composed of inorganic composite materials. The above may be included.
Thus, when the interference layer 40 has a layer made of a compound having a refractive index of 1.3 or more and 4.0 or less as a layer on the interface side with air, the phase of light incident from the air to the interference layer 40 is reversed. This is preferable because the interference effect with the light emitted from the interference layer 40 is enhanced.

Moreover, in the color forming structure 1, the interference layer 40 has a multilayer film configuration including a high refractive index compound and a low refractive index compound, and the refractive index difference between the high refractive index compound and the low refractive index compound is 0.6 or more. 2.2 or less.
Thus, by setting the refractive index difference between the high refractive index compound and the low refractive index compound to 0.6 or more and 2.2 or less, the light reflectance in a specific wavelength range is reflected in another wavelength range. The rate can be higher and the visibility of light in a particular wavelength range can be improved.

In addition, by forming the display 70 having the display element configured by the color forming structure 1, it is possible to configure a display having good visibility of light in a specific wavelength range.
At this time, as the display body 70, two coloring structures having a plurality of display elements in a plane and constituting the first display element and the second display element included in the plurality of display elements are made of the same material and thickness. Although the layer configuration is provided, the heights of the convex portions of the concavo-convex structure of the anti-reflection layer 30 may be different.

  With such a configuration, the first display element and the second display element exhibit colors of different hues, and the first display area where the first display element is located and the second display where the second display element is located In the area, colors of different hues are visually recognized. And since the configurations of the color forming structures are identical in the first display element and the second display element, it is not necessary to form a color forming structure layer for each display area, and display areas exhibiting different hues are provided. The display can be formed by a simple manufacturing process.

  At this time, it is a display body which has a display element comprised by the color development structure using the plasmon resonance phenomenon among the color development structures, and this display has a plurality of the display elements in a plane, and a plurality of the display The two color forming structures constituting the first display element and the second display element included in the element have the same layer structure of the same material and film thickness, but the height or unevenness structure 31 of the projections of the unevenness layer 20, 21 , 32 asperities may be arranged in different forms.

With such a configuration, the first display element and the second display element exhibit colors of different hues on the interference layer side (surface side), and the first display area and the second display area in which the first display element is located In the second display area in which the two display elements are located, colors with different hues are visually recognized. Further, also on the back surface side, since the concavo-convex portions of the concavo-convex structures 31 and 32 are different from each other, the absorption wavelength range by the plasmon resonance phenomenon can be changed. As a result, it is possible to visually recognize colors of different hues in each of the display areas on the front and back sides.
As a method of manufacturing the color forming structure 1, a method including a step of forming the concavo-convex structures 31 and 32 by transferring the concavities and convexities of the intaglio to a resin by a nanoimprinting method may be mentioned. By adopting this method, since the concavo-convex structure is formed at once in an arbitrary area by the nanoimprinting method, the formation of the fine concavo-convex structure can be suitably and easily produced.

A method of producing the display body 70 including the color forming structure 1 and the color forming structure described above will be described using specific examples.
Example 1
Example 1 is a display 70 provided with the color forming structure 1. The display body 70 in Example 1 is disposed on the uneven layer 21 provided with a multi-step uneven structure on one surface of the substrate 10 and the uneven layer 21 and repeats unevenness along the uneven structure of the uneven layer 21. The color developing structure 1 is provided with an interference layer 40 having a concavo-convex structure, and an anti-reflection layer 30 a having a concavo-convex structure 31 as an anti-reflection layer 30 on the other surface of the base material 10.

First, a mold, which is an intaglio plate used in the optical nanoimprinting method, was prepared. Specifically, since light of a wavelength of 365 nm was used as light to be irradiated in the photo nanoimprinting method, synthetic quartz which transmits light of this wavelength was used as a material of the mold.
In forming the mold, first, a film made of chromium (Cr) was formed by sputtering on the surface of a synthetic quartz substrate, 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 set of the plurality of first band-like shapes 201 shown in FIG. The length d1 of the first strip shape 201 in the first direction is 300 nm, and the length d2 of the first strip shape 201 in the second direction is selected from a normal distribution having an average value of 2000 nm and a standard deviation of 500 nm Length. In the pattern, the plurality of first strip shapes 201 are arranged so as not to overlap in the first direction. The resist used was positive 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 plasma generated by applying a high frequency to ethane hexafluoride gas. The depth of the etched synthetic quartz substrate was 70 nm. By removing the remaining resist and the Cr film, a synthetic quartz substrate having a concavo-convex structure corresponding to the arrangement pattern of the first strip shape 201 was obtained.

  Next, a film made of Cr was formed by sputtering on the surface of the synthetic quartz substrate having the above-mentioned concavo-convex structure 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 band-like regions shown in FIG. The length of the band-like region in the first direction is 200 nm, and the arrangement interval of the band-like regions in the first direction has an average value of 2000 nm and a standard deviation of 500 nm. 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 plasma generated by applying a high frequency to ethane hexafluoride gas. The depth of the etched synthetic quartz substrate was 65 nm. After removing the remaining resist and Cr film, OPTOOL HD-1100 (registered trademark, manufactured by Daikin Industries, Ltd.) was applied as a release agent to the surface of the synthetic quartz substrate. Thereby, the mold in which the uneven structure corresponding to the uneven structure of the uneven | corrugated layer 21 of multiple stages was formed was obtained. By the same manufacturing method, a mold for forming the anti-reflection layer 30 in which a concavo-convex structure corresponding to the concavo-convex structure 31 was formed was obtained.

  Next, a photocurable resin (PAK-02, manufactured by Toyo Gosei Co., Ltd.) is formed on the side of the polyester film (Cosmo Shine A4100 (registered trademark), made by Toyobo Co., Ltd.) which has been subjected to the easy adhesion processing on both sides. The surface of the mold on which the concavo-convex structure was formed was pressed against this resin, and light of 365 nm was irradiated from the back side of the mold. After curing of the photocurable resin by this light irradiation, the polyester film and the uneven layer 20 were peeled off from the mold. Thereby, the polyester film which is the base material 10 on which the concavo-convex layer 21 which consists of the 1st strip shape 201 and the 2nd strip shape 211 was laminated was obtained.

Next, a mold for producing a concavo-convex structure 31 having a bell shape in cross section, a cycle of 400 nm, a height of 200 nm, and an aspect ratio of 2.0 was prepared by the same method as the concavo-convex layer 21. Then, a photocurable resin (PAK-02, manufactured by Toyo Gosei Co., Ltd.) is applied to the surface opposite to the surface on which the concavo-convex layer 21 of the substrate 10 is formed, and the concavo-convex structure of the mold is formed on this resin. Was pressed and irradiated with 365 nm light from the back side of the mold. After the photocurable resin was cured by this light irradiation, the polyester film and the concavo-convex structure 31 were peeled off from the mold. Thereby, the polyester film which is substrate 10 in which antireflection layer 30 which has concavo-convex structure 31 was formed was obtained.
Next, a TiO ₂ film as a high refractive index layer with a film thickness of 80 nm and SiO _{2 as} a low refractive index layer with a film thickness of 70 nm and a film thickness of 150 nm The TiO ₂ film as a high refractive index layer was sequentially formed, and the interference layer 40 was formed on the concavo-convex layer 21 to obtain a color forming structure 1. Thus, a display 70 provided with the color forming structure 1 was obtained.

Example 2
In the second embodiment, an interference layer 20 having an unevenness structure on one surface of a substrate 10 and an interference layer formed on the unevenness layer 20 and having an unevenness structure repeating unevenness along the unevenness structure of the unevenness layer 20 40 is a color forming structure 1 in which an antireflective layer 30 b having a concavo-convex structure 32 as an antireflective layer 30 is formed on the other surface of the base material 10.
Specifically, in the same procedure as the concavo-convex structure 31 of Example 1, the rectangle having a rectangular cross-sectional shape, a film thickness of 150 nm, a short side length of 180 nm, and a long side length of 3 cm A mold for forming the concavo-convex structure 32 was formed, which was a pattern arranged at a period of 396 nm. Then, a photocurable resin (PAK-02, manufactured by Toyo Gosei Co., Ltd.) is applied to the surface of the substrate 10 opposite to the surface on which the uneven layer 20 is formed, and the surface on which the uneven structure of the mold is formed Was pressed and irradiated with 365 nm light from the back side of the mold. After curing the photocurable resin by the irradiation of this light, the polyester film and the concavo-convex structure were peeled off from the mold. Thereby, the polyester film which is the base material 10 on which antireflection layer 30b containing concavo-convex structure 32 was laminated was obtained.
Next, an Al film as a metal layer having a thickness of 50 nm is formed on the surface having the concavo-convex structure 32 by vacuum evaporation, and the metal layer 50 is formed on the upper surface of the convex portion and the upper surface of the concave portion of the concavo-convex structure 32 , And a colored structure 1 was obtained. Thus, a display 70 provided with the color forming structure 1 was obtained.

Comparative Example
A display of Comparative Example was obtained in the same manner as in Example 1 except that the antireflection layer 30 was not formed in Example 1. That is, in the comparative example, the concavo-convex layer 20 having the concavo-convex structure is disposed on the substrate 10, and the interference layer 40 having the concavo-convex structure repeating the concavo-convex structure is formed along the concavo-convex structure of the concavo-convex layer 20. A colored structure.

<Evaluation of Display>
When the display 70 of Example 1 and Example 2 was observed, blue with glossiness was confirmed with high visibility. In addition, when reflection spectroscopy measurement on the back surface side was performed in Example 2, a reflection spectrum having a center wavelength at about 620 nm was observed. On the other hand, in the comparative example, it was confirmed from the result of the example that the visibility of blue is lowered.
As mentioned above, although the embodiment of the present invention was described, the above-mentioned embodiment illustrates the device and the method for embodying the technical idea of the present invention, and the technical idea of the present invention is a component Does not specify the material, shape, structure, arrangement, etc. of The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

DESCRIPTION OF SYMBOLS 1 color development structure 10 base 20, 21 uneven layer 30 anti-reflective layer 31, 32 uneven structure 40 interference layer 41 a high refractive index layer 41 b low refractive index layer 50 metal layer 70 display 71 first display area 72 second display area 71A first pixel 72B second pixel

Claims (13)

A concavo-convex layer having a first concavo-convex structure that transmits light in the visible region;
It has a surface shape disposed on the concavo-convex layer and follows the first concavo-convex structure, and the reflectance of light in a specific wavelength range of incident light is higher than the reflectance of light in other wavelength ranges Higher one or more interference layers,
An anti-reflection layer disposed on a surface of the uneven layer opposite to the interference layer and absorbing at least a part of light transmitted through the interference layer;
In plan view, the region of the convex portion constituting the first concavo-convex structure is configured by combining a plurality of band-shaped patterns set in advance,
The strip pattern has a width along a first direction and a length along a second direction orthogonal to the first direction in plan view,
The color developing structure is characterized in that the width is shorter than the wavelength of the incident light, and the plurality of strip patterns forming the region of the convex portion have a standard deviation of the length larger than a standard deviation of the width. .   The color development according to claim 1, wherein the plurality of strip patterns are arranged to be parallel to one another in the first direction or to be collinear on the second direction. Structure. The antireflective layer has a second uneven structure on a surface opposite to the uneven layer.
The height in the film thickness direction of the second uneven structure is 10 nm or more and 500 nm or less,
The convex portions constituting the second concavo-convex structure are arranged in an island-like array in which any one or more of the non-ordered array, the square array and the hexagonal array are combined,
The structure period of the second uneven structure is 10 nm or more and 1000 nm or less,
The ratio of the width of the structural period of the second concavo-convex structure to the width of the recess constituting the second concavo-convex structure is 0.25 or more and 0.75 or less. The coloring structure as described in. The antireflective layer has a second uneven structure on the side opposite to the uneven layer,
The height in the film thickness direction of the second uneven structure is 10 nm or more and 200 nm or less,
The convex portions constituting the second concavo-convex structure are arranged in an island-like array in which any one or more of the non-ordered array, the square array and the hexagonal array are combined,
Further, the antireflective layer comprises a metal layer having a surface shape following the second uneven structure,
The structural period of the second uneven structure and the metal layer is a sub-wavelength period which is equal to or less than the wavelength of the visible region,
The ratio of the width of the structural period of the second concavo-convex structure to the width of the concave part of the second concavo-convex structure, and the ratio of the width of the convex part of the concavo-convex structure of the metal layer to the width of the concave part of the concavo-convex structure of the metal layer Is 0.25 or more and 0.75 or less, The coloring structure according to claim 1 or 2 characterized by the above-mentioned.   The metal layer has a metal, metal alloy and metal composite material having a refractive index of 0.2 to 6.0 in the visible light region, and an extinction coefficient of 2.0 to 6.0 in the visible light region. The coloring structure according to claim 4, comprising one or more of a metal, a metal alloy and a metal composite material.   The coloring structure according to any one of claims 1 to 5, wherein the antireflective layer contains a black pigment. The convex part which comprises the said 1st uneven structure of the said uneven | corrugated layer has a multistage shape in which the convex part which comprises the said 1st uneven structure, and a some strip | belt-shaped convex part overlap by at least one part,
The strip-like convex portion has a width along the first direction and a length along the second direction, and the plurality of strip-like convex portions are parallel to the second direction in the first direction. 7. The device according to any one of claims 1 to 6, wherein the arrangement intervals of the plurality of strip-like convex portions which are arranged at unequal intervals are such that the average value is 1/2 of the minimum wavelength in the wavelength range of the incident light. The coloring structure according to any one of the preceding claims.   The said interference layer contains one or more of the compounds which consist of an inorganic substance or an inorganic composite material whose refractive index is 1.3 or more and 4.0 or less. The coloring structure as described in a term.   The interference layer has a multilayer film configuration in which a high refractive index compound and a low refractive index compound are alternately stacked, and the refractive index difference between the high refractive index compound and the low refractive index compound is 0.6 or more and 2.2 or less. The coloring structure according to any one of claims 1 to 8, which is characterized in that   A display comprising the display element comprising the color forming structure according to any one of claims 1 to 9. Having a plurality of said display elements in a plane,
In the color forming structure forming one display element of the plurality of display elements and the color forming structure forming the other display element of the plurality of display elements, the uneven layer is formed of the first uneven layer The display body according to claim 10, wherein heights of convex portions forming the concavo-convex structure are different. A display having a display element comprising the color forming structure according to claim 4,
Having a plurality of said display elements in a plane,
In the color forming structure forming one display element of the plurality of display elements and the color forming structure forming another display element of the plurality of display elements, the first unevenness of the uneven layer A display body characterized in that heights of convex portions forming a structure are different, or shapes of the second uneven structure of the antireflection layer are different. A method for producing a color forming structure according to any one of claims 3 to 5, wherein
The concavo-convex structure for transfer is transferred to a resin by a nanoimprint method using an intaglio formed with a concavo-convex structure for transfer corresponding to the first concavo-convex structure or the second concavo-convex structure, to obtain the first A method of producing a color forming structure, comprising the step of forming a concavo-convex structure or the second concavo-convex structure.

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