JP2019159159A - Color structure and method for producing the same, display, color sheet, and molded article - Google Patents

Abstract

To provide a colored structure having a different color on both sides.SOLUTION: A color structure 30 includes a substrate 15, a concave and convex layers having a concavo-convex structure formed on a surface and back surface of a base material 15, and a multilayer film layer 16 having a surface shape that follows the concavo-convex structure of an uneven layer and follows the uneven structure. The convex portion 15a, 15x constituting the uneven structure, have one or more convex shapes, and the convex portion 15a projected onto a virtual plane is a virtual surface having the uneven structure has a pattern of the projected image of 15x constitutes in the thickness direction of the uneven layer. The length along the first direction Dx of the shape element is equal to or less than the sub-wavelength, and the standard deviation of the length along the second direction Dy is greater than the standard deviation of length along the first direction Dx in the plurality of shape elements.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coloring structure that exhibits a structural color and a method for producing the same, a display body and a coloring sheet that include the coloring structure, and a molded body that includes the coloring sheet.

The structural colors that are often observed as the colors of natural creatures such as morpho butterflies are different from the colors that are visible due to electronic transitions in molecules, such as the colors exhibited by pigments, such as light diffraction, interference, and scattering. It is a color visually recognized by the action of an optical phenomenon caused by the fine structure of the object.
For example, the structural color due to multilayer film interference is a structural color caused by interference of light reflected at each interface of the multilayer film in multilayer films having different refractive indexes of adjacent thin films. This is one of the coloring principles of morpho butterfly wings. In the morpho butterfly wing, in addition to the multilayer film interference, light is scattered and diffracted by the fine concavo-convex structure on the surface of the wing, so that a bright blue color is visible at a wide observation angle.

As a structure for artificially reproducing a structural color like a morpho butterfly wing, a structure in which a multilayer film layer is laminated on the surface of a substrate having fine irregularities arranged non-uniformly is proposed in Patent Document 1. ing.
In the multilayer film layer, the wavelength of light enhanced by interference varies depending on the optical path difference generated in each layer of the multilayer film layer, and the optical path difference is determined according to the film thickness and refractive index of each layer. And the outgoing direction of the light strengthened by the interference is limited to a specific direction depending on the incident angle of the incident light. Therefore, in the structure in which the multilayer film layers are laminated on the plane, the wavelength of the reflected light that is visually recognized varies greatly depending on the observation angle, and thus the visually recognized color varies greatly depending on the observation angle.

  On the other hand, in the structure disclosed in Patent Document 1, since the multilayer film layer is laminated on irregular irregularities, the reflected light enhanced by interference spreads in multiple directions. Change will be gradual. As a result, a structure that exhibits a specific color with a wide observation angle like a morpho butterfly wing is realized.

JP 2005-153192 A

By the way, in applications such as packages, there is a demand for structures that exhibit different colors on both sides. However, in the case of the above structure, only the same color appears on the front and back sides, and visibility may be deteriorated due to transmitted light. In order to improve the visibility, for example, when a black layer is overlaid, the color can be visually recognized only from one side by the black color.
Furthermore, when the structure described in Patent Document 1 is bonded to both surfaces using means such as dry lamination, there is an aging process in which wrinkles occur during bonding, the pattern is lost due to pressing pressure and the material of the guide roll. In some cases, additional problems may be required and productivity may be reduced.

When such a concavo-convex structure collapses, the optical path length of the light reflected by the multilayer film changes or the effect of diffusing the reflected light in multiple directions decreases, so that the desired color can be obtained in the structure. It becomes difficult. In addition, since an additional process is required, problems such as an increase in production cost arise.
An object of the present invention is to provide a coloring structure, a display, a coloring sheet, a molded body, and a method for producing the coloring structure that exhibit different colors on both sides.

  The color developing structure according to one embodiment of the present invention includes a base material, a first concave-convex layer having a concave-convex structure formed on the substrate surface or the base, and the first concave-convex layer side of the base material. The second concavo-convex layer having the concavo-convex structure formed on the surface, the concavo-convex structure of the first concavo-convex layer and the concavo-convex structure of the second concavo-convex layer, respectively, and a surface shape following these concavo-convex structures A plurality of layers of the multilayer film layer, the layers adjacent to each other have different refractive indexes, and light in a specific wavelength region of incident light incident on the multilayer film layer Of the first concavo-convex layer and the second concavo-convex layer in the thickness direction of the first concavo-convex layer and the second direction orthogonal to the first direction. The convex portion constituting the concave-convex structure has a convex shape of one or more steps in a direction included in a virtual plane that is a virtual plane onto which the concave-convex structure is projected. The pattern formed by the projected image of the convex portion projected onto the virtual plane is a pattern composed of a set of a plurality of graphic elements whose length along the second direction is equal to or longer than the length along the first direction. The length along the first direction of the graphic element is equal to or less than the sub-wavelength, and the standard deviation of the length along the second direction is the standard deviation of the length along the first direction in the plurality of graphic elements It is gist that it is larger than.

A method for producing a color developing structure according to another aspect of the present invention is a method for producing a color developing structure according to the above aspect, wherein the uneven structure of the first uneven layer and the uneven structure of the second uneven layer are provided. The gist is to produce at least one by the photoimprint method or the thermal imprint method.
The gist of a display body according to another aspect of the present invention is that it includes the color developing structure according to the above aspect.

The gist of a color developing sheet according to another aspect of the present invention is that it includes the color developing structure according to the above aspect.
The gist of a molded body according to another aspect of the present invention is to include the color developing sheet according to the other aspect.

  ADVANTAGE OF THE INVENTION According to this invention, the coloring structure, display body, coloring sheet, and molded object which show a different color on both surfaces can be provided.

It is sectional drawing which shows the cross-section of the coloring structure which has 1st structure about one Embodiment of the coloring structure which concerns on this invention. 1A is a plan view showing a planar structure of a concavo-convex structure viewed from the first concavo-convex layer side in the first structure, and FIG. It is sectional drawing which shows the cross-section of the uneven structure of the 1st uneven | corrugated layer in the structure of 1. FIG. It is sectional drawing which shows the cross-section of the color development structure by the side of the 1st uneven | corrugated layer which has 2nd structure about one Embodiment of the color development structure which concerns on this invention. About one embodiment of the coloring structure concerning the present invention, (a) is a top view showing the plane structure of the concavo-convex structure which consists only of the 2nd convex part element in the 2nd structure, and (b) is the 2nd It is sectional drawing which shows the cross-section of the uneven structure which consists only of the 2nd convex part element in the structure of. 1A is a plan view showing a planar structure of the concavo-convex structure in the second structure, and (b) is a cross-sectional structure of the concavo-convex structure in the second structure, regarding one embodiment of the color forming structure according to the present invention. FIG. It is sectional drawing which shows the cross-section of the coloring structure of a modification about one Embodiment of the coloring structure which concerns on this invention. It is sectional drawing which shows the cross-section of the coloring structure of a modification about one Embodiment of the coloring structure which concerns on this invention. It is a top view which shows the planar structure of a display body about one Embodiment of the display body which concerns on this invention. It is sectional drawing which shows the cross-section of a display body about one Embodiment of the display body which concerns on this invention.

With reference to FIGS. 1-9, one Embodiment of the coloring structure, the display body, the coloring sheet, a molded object, and the manufacturing method of a coloring structure which concern on this invention is described.
[Coloring structure]
The color developing structure of the present embodiment includes a concavo-convex structure having a multilayer film on both the front and back surfaces. As the concavo-convex structure of the concavo-convex structure, both a first structure and a second structure described later can be applied. First, each of these two structures will be described.

  In addition, although the wavelength range of incident light and reflected light with respect to the coloring structure is not particularly limited, in the following description, the coloring structure for light in the visible region will be described as an example. In the present embodiment, light in the wavelength region of 360 nm or more and 830 nm or less is set as light in the visible region.

<First structure>
FIG. 1 shows a coloring structure 30 including a concavo-convex structure 10 having a first structure and a concavo-convex structure 20 having a first structure arranged on the opposite side of the concavo-convex structure 10.
The concavo-convex structures 10 and 20 are made of a material that transmits light in the visible region, and are laminated on the base 15 that is an example of the concavo-convex layer having a concavo-convex structure on the front and back surfaces, and on the front and back surfaces of the base 15. The multilayer film layer 16 is provided. That is, the multilayer film layer 16 covers the surface of the base material 15 where the irregularities are formed. The concavo-convex structure of the base material 15 includes a plurality of convex portions 15a and 15x and concave portions 15b and 15y that are regions between the plurality of convex portions 15a. The convex portions 15a and 15x have irregular lengths. It is comprised from the part extended in substantially strip | belt shape.

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

  The configuration of the multilayer film layer 16, that is, the material, film thickness, and stacking order of the layers constituting the multilayer film layer 16 are the same on the convex portion 15 a and the concave portion 15 b in the base material 15. And the surface which is a surface on the opposite side to the base material 15 in the multilayer film layer 16 is the surface shape which followed the uneven structure of the base material 15, ie, the arrangement | positioning corresponding to arrangement | positioning of the unevenness | corrugation formed in the base material 15. It has irregularities.

  Similarly, the structure of the multilayer film layer 16, that is, the material, film thickness, and stacking order of the multilayer film layer 16 are the same on the convex portion 15 x and the concave portion 15 y in the base material 15. And the surface which is a surface on the opposite side to the base material 15 in the multilayer film layer 16 is the surface shape which followed the uneven structure of the base material 15, ie, the arrangement | positioning corresponding to arrangement | positioning of the unevenness | corrugation formed in the base material 15. It has irregularities. The multilayer film layer 16 constitutes an optical functional layer.

  In such a structure, when light is incident on the coloring structure 30 from the side where the concavo-convex structure 10 is located, the light reflected at each interface between the high refractive index layer 16a and the low refractive index layer 16b in the multilayer film layer 16 interferes. As a result, the traveling direction is changed due to irregular irregularities on the surface of the multilayer film layer 16. As a result, light in a specific wavelength region is emitted at a wide angle. The specific wavelength region that is strongly emitted as the reflected light is determined by the material and film thickness of the high refractive index layer 16a and the low refractive index layer 16b, and the width, height, and arrangement of the convex portions 15a.

Similarly, when light is incident on the coloring structure 30 from the side where the concavo-convex structure 20 is located, reflected light in a specific wavelength region is emitted at a wide angle. That is, the coloring structure 30 may be observed from either side of the concavo-convex structure 10 and the concavo-convex structure 20. The uneven structure 10 and the uneven structure 20 may have the same structure or different structures. That is, the widths, heights, and arrangements of the protrusions 15a and 15x may be different.
In FIG. 1, the same multilayer film layer 16 is described in the concavo-convex structure body 10 and the concavo-convex structure body 20 as an example. However, the present invention is not limited to this, and the material and film thickness of the multilayer film layer 16 and the number of layers are not limited. 10 and the concavo-convex structure 20 may be the same or different.

  With reference to FIG. 2, the detail of the uneven structure which the base material 15 which is an uneven | corrugated layer has is demonstrated. FIG. 2A is a plan view of the substrate 15 as viewed from the direction facing the surface, that is, from the first uneven layer side, and FIG. 2B is a line 2-2 in FIG. It is sectional drawing which shows the cross-section of the base material 15 along. In FIG. 2A, the convex portions 15a constituting the concave-convex structure are shown with dots.

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

In the virtual plane, the pattern formed by the projected images of the convex portions 15a and 15x is a pattern composed of a set of a plurality of rectangles R indicated by broken lines. The rectangle R is an example of a graphic element. The rectangle R has a shape extending in the second direction Dy. In the rectangle R, the length d2 in the second direction Dy has a length greater than or equal to the length d1 in the first direction Dx. The plurality of rectangles R are arranged so as not to overlap in either the first direction Dx or the second direction Dy.
In the plurality of rectangles R, the length d1 in the first direction Dx is constant, and the plurality of rectangles R are arranged in the first direction Dx at an arrangement interval of the length d1, that is, a period of the length d1. .

  On the other hand, in the plurality of rectangles R, the length d2 in the second direction Dy is irregular, and the length d2 in each rectangle R is a value selected from a population having a predetermined standard deviation. This population preferably follows a normal distribution. A pattern composed of a plurality of rectangles R, for example, temporarily lays out a plurality of rectangles R having a length d2 distributed with a predetermined standard deviation in a predetermined region, and determines whether or not each rectangle R is actually arranged according to a certain probability. By determining, the region where the rectangle R is arranged and the region where the rectangle R is not arranged are set. In order to efficiently scatter the reflected light from the multilayer film layer 16, the length d2 preferably has a distribution with an average value of 4.15 μm or less and a standard deviation of 1 μm or less.

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

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

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

  Similarly, it is preferable that the ratio of the area occupied by the protrusions 15x per unit area is 40% or more and 60% or less when viewed from the direction facing the back surface of the substrate 15. For example, when viewed from the direction facing the surface of the substrate 15, the ratio of the area of the convex portion 15 x to the concave portion 15 y per unit area is preferably 1: 1.

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

  Similarly, the height of the convex portion 15x is also constant, and may be set according to a desired color to be developed by the color forming structure 30, that is, a wavelength range desired to be reflected from the color forming structure 30. If the height of the convex portion 15x is larger than the surface roughness of the multilayer film layer 16 on the convex portion 15x or the concave portion 15y, the scattered light scattering effect can be obtained. In addition, the height of the convex part 15a and the convex part 15x may correspond, and may differ.

  However, in order to suppress the interference of light caused by reflection on the unevenness of the surface of the multilayer layer 16, the height h1 of the convex portion 15a and the height of the convex portion 15x are ½ of the wavelength of light in the visible region. Or less, that is, 415 nm or less. Furthermore, in order to suppress the light interference, the height h1 is more preferably ½ or less of the peak wavelength of the light in the specific wavelength region reflected from the multilayer film layer 16.

Further, if the height h1 of the convex portion 15a and the height of the convex portion 15x are excessively large, the scattering effect of the reflected light becomes too high and the intensity of the reflected light tends to be low. In this case, the height h1 of the convex portion 15a and the height of the convex portion 15x are preferably 10 nm or more and 200 nm or less. For example, in the color developing structure 30 exhibiting blue, in order to obtain an effective light spread, the height h1 of the convex portion 15a and the height of the convex portion 15x are preferably about 40 nm or more and 150 nm or less, In order to suppress the scattering effect from becoming too high, it is preferable that the height of the convex portion 15a and the height of the convex portion 15x are 100 nm or less.
Note that the rectangle R is arranged so that a part of two rectangles R arranged along the first direction Dx overlap each other, thereby forming a pattern of the convex portion 15a and / or the convex portion 15x in the virtual plane. Also good.

  That is, the plurality of rectangles R may be arranged in the first direction Dx with an arrangement interval smaller than the length d1, and the arrangement intervals of the rectangles R may not be constant. In a portion where the rectangles R overlap, one convex portion 15a and one convex portion 15x are located in one region where the regions where the rectangles R are arranged are combined. In this case, the length of the convex portion 15a and the convex portion 15x in the first direction Dx is different from an integral multiple of the length d1 of the rectangle R. In addition, the length d1 of the rectangle R may not be constant. In each rectangle R, the length d2 is not less than the length d1, and the standard deviation of the length d2 in the plurality of rectangles R is the length d1. It only needs to be larger than the standard deviation. Even with such a configuration, the scattering effect of the reflected light can be obtained.

<Second structure>
FIG. 3 shows a coloring structure 31 including the concavo-convex structure 11 having the second structure.
Compared with the concavo-convex structure 10 having the first structure, the concavo-convex structure 11 having the second structure has a configuration of the concavo-convex structure in the substrate 15, that is, the configuration of the concavo-convex structure on the surface of the multilayer film layer 16. Unlike this, the configuration of the concavo-convex structure is the same as that of the concavo-convex structure 10 having the above-described first structure except for the configuration of the concavo-convex structure.

Hereinafter, the color forming structure 31 will be described with a focus on the differences from the above-described color forming structure 30, and the same components as those of the color forming structure 30 will be denoted by the same reference numerals and description thereof will be omitted. At this time, the second concavo-convex structure may be either the first structure or the second structure. The first concavo-convex structure may be the first structure, and the second concavo-convex structure may be the second structure.
The convex portion 15c constituting the concave-convex structure of the base material 15 in the concave-convex structure 11 includes a first convex element having the same configuration as the convex portion 15a in the first structure and a second convex element extending in a strip shape. The substrate 15 has a structure superimposed in the thickness direction.

  According to the coloring structure 30 having the first structure, although the change due to the observation angle of the color to be visually recognized is moderate due to the scattering effect of the reflected light, it is visually recognized due to the decrease in the intensity of the reflected light due to the scattering. Color vividness decreases. Depending on the use of the color developing structure, a structure capable of observing more vivid colors at a wide viewing angle may be required. In the second structure, the second convex elements are arranged so that incident light is strongly diffracted in a specific direction, and the light scattering effect by the first convex elements and the light by the second convex elements are arranged. Due to the diffraction effect, the color forming structure 31 capable of observing brighter colors at a wide viewing angle is realized.

  With reference to FIG. 4, the structure of a 2nd convex part element is demonstrated. 4A is a plan view of the concavo-convex structure including only the second convex element, and FIG. 4B is a cross-sectional view showing a cross-sectional structure taken along line 4-4 of FIG. 4A. is there. In FIG. 4A, the second convex element is shown with dots.

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

  The arrangement interval de of the second convex element 15Eb in the first direction Dx, that is, the arrangement interval of the band-like regions in the first direction Dx is at least one of the reflected light on the surface of the concavo-convex structure formed by the second convex element 15Eb. The part is set to be observed as first-order diffracted light. In other words, the first-order diffracted light is diffracted light having a diffraction order m of 1 or -1. That is, when the incident angle of incident light is θ, the reflection angle of reflected light is φ, and the wavelength of diffracted light 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 convex elements 15Eb may be 180 nm or more, that is, the arrangement interval de is the minimum wavelength in the wavelength region included in the incident light. It is sufficient if it is 1/2 or more of the above. The arrangement interval de is a distance along the first direction Dx between the ends of two adjacent second convex elements 15Eb, and is the same as the second convex element 15Eb in the first direction Dx. It is the distance between the edge parts located in the side.

  The periodicity of the pattern formed by the second convex element 15Eb is reflected in the periodicity of the uneven structure of the substrate 15, that is, the periodicity of the uneven structure on the surface of the multilayer film layer 16. When the arrangement interval de of the plurality of second convex elements 15Eb is constant, reflected light of a specific wavelength is emitted from the multilayer film layer 16 at a specific angle due to a diffraction phenomenon on the surface of the multilayer film layer 16. . The reflection intensity of the light due to this diffraction is very strong compared to the reflection intensity of the reflected light generated by the light scattering effect by the first convex element described in the first structure described above, so that Light having brightness is visually recognized, but on the other hand, diffraction due to diffraction occurs, and the color visually recognized changes according to the change in the observation angle.

  Therefore, for example, even if the structure of the first convex element is designed so as to obtain the color developing structure 31 exhibiting blue, the arrangement interval de of the second convex elements 15Eb is a constant value of about 400 nm to 5 μm. Depending on the observation angle, light from strong green to red surface reflections due to diffraction is observed. On the other hand, for example, if the arrangement interval de of the second convex elements 15Eb is increased to about 50 μm, the range of angles at which the light in the visible region is diffracted becomes narrow, so that the color change due to diffraction is difficult to be visually recognized. However, light having a brightness like metallic luster is observed only at a specific observation angle.

  Therefore, if the arrangement interval de is not set to a constant value and the pattern of the second convex element 15Eb is a pattern in which a plurality of periodic structures having different periods are overlapped, light of a plurality of wavelengths is mixed with reflected light by diffraction. For this reason, the light having a high spectral monochromaticity is hardly visible. Therefore, vivid colors with a glossy appearance are observed at a wide observation angle. In this case, the arrangement interval de is selected from a range of, for example, 360 nm or more and 5 μm or less, and the average value of the arrangement intervals de of the plurality of second convex element 15Eb is 1 / of the minimum wavelength in the wavelength range included in the incident light. What is necessary is just two or more.

However, as the standard deviation of the arrangement interval de increases, the arrangement of the second convex elements 15Eb becomes irregular and the scattering effect becomes dominant, making it difficult to obtain strong reflection due to diffraction. Therefore, the arrangement interval de of the second convex element 15Eb emits the reflected light by diffraction in a range similar to the range in which the light spreads according to the angle at which the light is spread by the light scattering effect by the first convex element. It is preferable to determine as follows. For example, when blue reflected light is emitted in a range of ± 40 ° with respect to the incident angle, in the pattern of the second convex element 15Eb, the arrangement interval de is an average value of 1 μm or more and 5 μm or less. The standard deviation is set to about 1 μm. Thereby, the reflected light by diffraction arises in the same angle as the angle which light spreads by the light scattering effect of the 1st convex part element.
That is, unlike the structure for diffracting and taking out light in a specific wavelength region, the structure composed of the plurality of second convex elements 15Eb has a predetermined angular range using diffraction due to dispersion of the arrangement interval de. This is a structure for emitting light in various wavelength ranges.

  Further, in order to generate a longer-period diffraction phenomenon, a square region having a side of 10 μm or more and 100 μm or less is used as a unit region, and in the pattern of the second convex element 15Eb for each unit region, The standard deviation may be about 1 μm or more and 5 μm or less, and the standard deviation may be about 1 μm. Note that the plurality of unit regions may include a region having a constant value that is included in the range in which the arrangement interval de is 1 μm or more and 5 μm or less. Even if there is a unit region where the arrangement interval de is constant, if the arrangement interval de has a variation with a standard deviation of about 1 μm in any of the unit regions adjacent to this unit region, the resolution of the human eye In this case, it is possible to expect the same effect as the configuration in which the arrangement interval de varies in all unit regions.

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

  In such a pattern of the second convex element 15Eb, for example, each of the arrangement interval along the first direction Dx and the arrangement interval along the second direction Dy of the band-like region has an average value of 1 μm or more and 100 μm or less. As long as there is variation, it is sufficient. Further, according to the difference between the influence of the light scattering effect by the first convex element on the first direction Dx and the influence on the second direction Dy, the average value of the arrangement interval along the first direction Dx, and the first The average value of the arrangement intervals along the two directions Dy may be different from each other, and the standard deviation of the arrangement intervals along the first direction Dx is different from the standard deviation of the arrangement intervals along the second direction Dy. It may be.

  As shown in FIG. 4B, the height h2 of the second convex element 15Eb only needs to be larger than the surface roughness of the multilayer film layer 16 on the convex part 15c and the concave part 15b. However, as the height h2 is increased, the diffraction effect by the second convex element 15Eb is dominant in the effect of the concavo-convex structure on the reflected light, and the light scattering effect by the first convex element is less likely to be obtained. The height h2 is preferably approximately the same as the height h1 of the first convex element, and the height h2 may coincide with the height h1. For example, the height h1 of the first convex element and the height h2 of the second convex element 15Eb are preferably included in the range of 10 nm or more and 200 nm or less. It is preferable that the height h1 of the first convex element and the height h2 of the second convex element 15Eb are included in the range of 10 nm to 150 nm.

  With reference to FIG. 5, the detail of the uneven structure which the uneven structure 11 of a 2nd structure has is demonstrated. Fig.5 (a) is the top view which looked at the base material 15 from the direction facing the surface, FIG.5 (b) is the cross section of the base material 15 along the 5-5 line | wire of Fig.5 (a). It is sectional drawing which shows a structure. In FIG. 5A, the patterns formed by the first convex elements and the patterns formed by the second convex elements are shown with dots having different densities.

  As shown in FIG. 5A, in the virtual plane, the pattern formed by the projected image of the convex portion 15c is the first pattern that is the pattern formed by the projected image of the first convex portion element 15Ea, and the second pattern. This is a pattern in which a second pattern that is a pattern formed by the projection image of the convex element 15Eb is superimposed. That is, in the region where the convex portion 15c is located, the region S1 composed only of the first convex element 15Ea, the region S2 where the first convex element 15Ea and the second convex element 15Eb overlap, And a region S3 including only the two convex elements 15Eb. In FIG. 5, the first convex element 15Ea and the second convex element 15Eb are overlapped so that the end portions thereof are aligned in the first direction Dx. The end of the element 15Ea and the end of the second convex element 15Eb may be offset.

As shown in FIG. 5B, in the region S1, the height of the convex portion 15c is the height h1 of the first convex portion element 15Ea. In the region S2, the height of the convex portion 15c is the sum of the height h1 of the first convex portion element 15Ea and the height h2 of the second convex portion element 15Eb. In the region S3, the height of the convex portion 15c is the height h2 of the second convex portion element 15Eb. As described above, in the projection 15c, the projection image on the virtual plane forms the first pattern, and the projection image on the virtual plane forms the second pattern with the first projection element 15Ea having the predetermined height h1. And the 2nd convex part element 15Eb which has predetermined | prescribed height h2 has the multistage shape piled up in the height direction. The convex portion 15c can also be regarded as a structure in which the second convex portion element 15Eb is superimposed on the first convex portion element 15Ea, and a structure in which the first convex portion element 15Ea is superimposed on the second convex portion element 15Eb. It is also possible to capture.
In such a structure, the concavo-convex structure on the surface of the multilayer film layer 16 is more complex than the first structure, and thus the concavo-convex structure may be deformed. Therefore, the uneven structure of the multilayer film layer 16 may be protected by a protective layer.

  As described above, according to the coloring structure 31 having the second structure, the light diffusion phenomenon caused by the portion of the convex portion 15c formed by the first convex element 15Ea and the second convex portion element 15Eb are configured. By combining with the diffraction phenomenon of light caused by the part to be reflected, the reflected light in a specific wavelength range can be observed at a wide observation angle, and the intensity of this reflected light is increased, resulting in a vivid color with glossiness. Visible. In other words, in the second structure, the convex portion 15c, which is one structure, has two functions of a light diffusion function and a light diffraction function.

  In the virtual plane, the pattern formed by the first convex element 15Ea and the pattern configured by the second convex element 15Eb do not overlap the first convex element 15Ea and the second convex element 15Eb. May be arranged. Even with such a structure, the light diffusion effect by the first convex element 15Ea and the light diffraction effect by the second convex element 15Eb can be obtained. However, if the first convex element 15Ea and the second convex element 15Eb are arranged so as not to overlap each other, the first convex element 15Ea can be arranged per unit area as compared with the first structure. The area is reduced, and the light diffusion effect is reduced. Therefore, in order to enhance the light diffusion effect and diffraction effect by the convex elements 15Ea and 15Eb, as shown in FIG. 5, the first convex element 15Ea and the second convex element 15Eb are overlapped to form a convex part. It is preferable to make 15c into a multistage shape.

[Method for producing colored structure]
The material of each layer constituting the coloring structures 30 and 31 and the method for manufacturing the coloring structures 30 and 31 will be described.
The base material 15 is made of a material that is transparent to light in the visible region, that is, a material that is transparent to light in the visible region. For example, as the base material 15, a synthetic quartz substrate or a film made of a resin such as polyethylene terephthalate (PET) is used. The concavo-convex structure on the surface of the substrate 15 is formed by using a known fine processing technique such as lithography or dry etching that irradiates light or charged particle beams.

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

  The high-refractive index layer 16a and the low-refractive index layer 16b constituting the multilayer film layer 16 are made of a material that is transparent to light in the visible region, that is, a material that is transparent to light in the visible region. The The material of these layers is not limited as long as the refractive index of the high refractive index layer 16a is higher than the refractive index of the low refractive index layer 16b, but the refraction of the high refractive index layer 16a and the low refractive index layer 16b is not limited. The greater the difference in the ratio, the higher the intensity of the reflected light with the smaller number of layers.

From such a viewpoint, for example, when the high refractive index layer 16a and the low refractive index layer 16b are made of an inorganic material, the high refractive index layer 16a is made of titanium dioxide (TiO ₂ ), and the low refractive index layer 16b is made of silicon dioxide. Preferably, it is composed of (SiO ₂ ). Each of the high refractive index layer 16a and the low refractive index layer 16b made of such an inorganic material is formed 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 16a and the low refractive index layer 16b may be made of an organic material. In this case, the formation of the high refractive index layer 16a and the low refractive index layer 16b is a well-known method such as self-organization. This technique may be used.

The film thickness of each of the high refractive index layer 16a and the low refractive index layer 16b may be designed using a transfer matrix method or the like according to a desired color to be developed by the color forming structures 30 and 31. For example, when forming the color developing structures 30 and 31 exhibiting blue, the film thickness of the high refractive index layer 16a made of TiO ₂ is preferably about 40 nm, and the film thickness of the low refractive index layer 16b made of SiO _2. Is preferably about 75 nm.

  1 and 3, as the multilayer film layer 16, a multilayer film layer 16 composed of 10 layers in which a high refractive index layer 16a and a low refractive index layer 16b are alternately stacked in this order from a position close to the base material 15. However, the number of layers and the order of lamination of the multilayer film layer 16 are not limited to this, and the high refractive index layer 16a and the low refractive index layer 16b are designed so that reflected light in a desired wavelength region can be obtained. It only has to be. For example, the low refractive index layer 16b may be in contact with the surface of the substrate 15, and the high refractive index layer 16a and the low refractive index layer 16b may be alternately stacked thereon.

Further, the layer constituting the outermost surface which is the surface opposite to the base material 15 in the multilayer film layer 16 may be either the high refractive index layer 16a or the low refractive index layer 16b. Furthermore, if the low-refractive index layers 16b and the high-refractive index layers 16a are alternately laminated, the material constituting the layer that contacts the surface of the substrate 15 and the layer that constitutes the outermost surface are the same. Also good. Furthermore, the multilayer film layer 16 may be configured by a combination of three or more layers having different refractive indexes.
In short, the multilayer film layer 16 has mutually different refractive indexes of adjacent layers, and the reflectance of light in a specific wavelength region of the incident light incident on the multilayer film layer 16 is reflected in other wavelength regions. What is necessary is just to be comprised so that it may be higher than a rate.

  Here, when the concavo-convex structures 10, 11, and 20 are formed of a material that is transparent to light in the visible region, the specific structure reflected by the multilayer film layer 16 in the wavelength range included in the incident light. Part of light in a wavelength region other than the wavelength region is transmitted through the multilayer film layer 16 and the concavo-convex structures 10, 11, and 20. Therefore, when the concavo-convex structure 10, 11, 20 is observed from one side of the front and back, there is a structure that repels transmitted light, such as a light source or a white plate, on the other side of the concavo-convex structure 10, 11, 20 On the one side, the transmitted light transmitted through the multilayer film layer 16 from the other side is visually recognized together with the reflected light in a specific wavelength range from the multilayer film layer 16. As described above, the wavelength range of the transmitted light is different from the wavelength range of the reflected light, and the color of the transmitted light is mainly a complementary color of the color of the reflected light. For this reason, when such transmitted light is visually recognized, the color visibility by reflected light is lowered.

  Therefore, light transmitted from the first optical functional layer composed of the first uneven layer and the multilayer film layer thereon, and the second optical functional layer composed of the second uneven layer and the multilayer film layer thereon. The color difference Δab from the reflected light is preferably 25 or less. Or, the light transmitted from the second concavo-convex layer and the second optical functional layer made of the multilayer film thereon, and the first optical functional layer made of the first concavo-convex layer and the multilayer film layer thereon. The total color difference Δab of the reflected light is preferably 25 or less.

  In this case, the reflected light from the surface to be observed and the transmitted light from the other side of the surface to be observed have similar colors, and the decrease in visibility due to the transmitted light is suppressed, and the transmitted light from the other side overlaps. Thus, a desired color development can be suitably obtained on both sides of the color forming structures 30 and 31. In addition, the color of these transmitted light and reflected light is the value measured with the spectrophotometer UV-3600 (made by Shimadzu Corporation). The color difference Δab is the sum of the square of the difference between the a values of the transmitted light and the reflected light and the square of the difference between the b values of the transmitted light and the reflected light.

It is also preferable that the base material 15 is made of a material that absorbs transmitted light that has passed through the multilayer film layer 16 of incident light. In this case, the transmitted light from the other side can be suppressed. According to such a configuration, since the light transmitted through the multilayer film layer 16 is absorbed by the base material 15, the transmitted light from the side opposite to the observation surface, that is, the other side can be suppressed. It is suppressed that the light of the wavelength range different from the reflected light from 16 is visually recognized. Therefore, regardless of the difference in the wavelength range of the transmitted light according to the configuration of the multilayer film 16, it is possible to suppress a decrease in the color visibility due to the transmitted light, and the desired color development can be achieved on both sides in the color forming structures 30 and 31. Preferably obtained.
For example, the base material 15 should just be a layer containing the material which absorbs light of visible region, such as a light absorber and a black pigment. Specifically, the base material 15 is preferably a layer in which a black inorganic pigment such as carbon black, titanium black, black iron oxide, or black composite oxide is mixed with a resin.

  The base material 15 has such a light absorptivity as long as it has a light absorptivity that absorbs at least part of the light transmitted through the multilayer film layer 16 without absorbing all the light in the visible region. Compared to a configuration in which no layer is provided, an effect of suppressing a decrease in color visibility due to reflected light can be obtained. Therefore, the base material 15 may be a layer containing a pigment having a color corresponding to the wavelength range of light transmitted through the multilayer film layer 16. However, if the base material 15 is a black layer containing a black pigment, it is not necessary to adjust the color of the base material 15 according to the wavelength range of transmitted light on the front and back sides, and the base material 15 has a wide wavelength range. Since light is absorbed, a decrease in color visibility due to reflected light can be suppressed easily and suitably.

The multilayer film layer 16 may be covered with a protective layer that protects the surface of the multilayer film layer 16. When the surface of the multilayer film layer 16 is covered with a protective layer, the concavo-convex structure of the multilayer film layer 16 collapses, specifically, deformation of the concavo-convex structure and clogging of the concavo-convex structure with dirt and foreign matter can be suppressed. .
The protective layer is preferably composed of a material that is transparent to light in the visible region, that is, a material that is transparent to light in the visible region. Examples of such materials include acrylic, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene and polyethylene, resins such as polyvinyl chloride, polycarbonate, polyvinyl alcohol, polystyrene, and polyamide.

Moreover, the protective layer may contain the ultraviolet absorber. As the UV absorber, known UV absorbers such as benzophenone, benzotriazole, benzoate, salicylate, triazine, and cyanoacrylate can be used.
If the protective layer includes an ultraviolet absorber, the protective layer absorbs ultraviolet rays when the color developing structures 30 and 31 are used for a long time exposure to ultraviolet rays caused by direct sunlight or the like. It is suppressed that the material which comprises the structures 30 and 31 deteriorates with an ultraviolet-ray.

  The protective layer is formed on the surface of the multilayer film 16 using a known coating method such as an inkjet method, a spray method, a bar coating method, a roll coating method, a slit coating method, or a gravure coating method. Although the film thickness of a protective layer is not specifically limited, For example, it is preferable that it is a grade of 1 micrometer or more and 100 micrometers or less.

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

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

[Modified example of coloring structure]
The coloring structure may have the configuration shown in FIG. The concavo-convex structure 12 and the concavo-convex structure 21 provided in the color forming structure 32 shown in FIG. 6 include a base material 15, a resin layer 17 covering the surface of the base material 15, and a multilayer film layer 16 laminated on the resin layer 17. Is provided. The surface of the base material 15 is flat, and the resin layer 17 has irregularities on the surface. In the form shown in FIG. 6, the laminated body of the base material 15 and the resin layer 17 is an uneven | corrugated layer. As the concavo-convex structure on the surface of the resin layer 17, both the concavo-convex structure of the first structure and the concavo-convex structure of the second structure described above can be applied.

  Further, both the front and back surfaces of the base material 15 may be flat as shown in FIG. 6, but this is not a limitation, and only one surface of the base material 15 is flat and the resin layer 17 and the multilayer film layer are only on the flat surface. 16 may be provided. In this case, the other surface has a concavo-convex structure directly on the base material 15 as in FIGS.

  As a method for forming the concavo-convex structure of the resin layer 17, for example, a nanoimprint method is used. If the nanoimprint method is used, formation of the concavo-convex structure is realized suitably and simply. For example, when the concavo-convex structure of the resin layer 17 is formed by the optical nanoimprint method, first, the resin constituting the resin layer 17 is formed on the surface on which the concavo-convex shape of the intaglio having the concavo-convex inversion of the formation target is formed. As a photocurable resin is applied. The coating method of the photocurable 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.

  Next, the substrate 15 is overlaid on the surface of the coating layer made of a photocurable resin, and light is irradiated from the substrate 15 side or the mold side in a state where the coating layer and the mold are pressed against each other. Subsequently, the mold is released from the cured photocurable resin and the base material 15. Thereby, the unevenness of the mold is transferred to the photocurable resin, and the resin layer 17 having the unevenness on the surface is formed. The mold is made of, for example, synthetic quartz or silicon, and is formed using a well-known fine processing technique such as lithography or dry etching that irradiates light or charged particle beams.

The photocurable resin may be applied to the surface of the base material 15 and irradiated with light in a state where the mold is pressed against the coating layer on the base material 15.
Further, instead of the optical nanoimprint method, a thermal nanoimprint method may be used. In this case, as the resin of the resin layer 17, a resin according to the manufacturing method such as a thermoplastic resin or a thermosetting resin is used. .

  Further, as shown in FIG. 7, an aluminum thin film layer having a thickness of 1 nm or more and 7 nm or less may be arranged between the base material 15 and the concavo-convex structure formed on the base material 15. By providing the aluminum thin film layer, the aluminum thin film layer can prevent water vapor from being transmitted, and thus the water vapor transmission rate can be lowered. When the thickness of the aluminum thin film layer is 8 nm or more, a metallic luster is generated, and thus visibility is lowered due to the metallic luster. On the other hand, in the case of less than 1 nm, the effect of lowering the water vapor transmission rate by the aluminum thin film layer is not seen. By using an aluminum thin film layer of 1 to 7 nm, it is possible to reduce the water vapor transmission rate while preventing a reduction in visibility. The method for producing the aluminum thin film layer is not particularly limited, and can be produced by a conventionally known method such as sputtering or vacuum deposition. This aluminum thin film layer may be provided on both sides of the substrate, or may be provided only on one side.

  The uneven structure formed on the base material 15 may include a light-absorbing material that absorbs at least part of the light transmitted through the multilayer film layer 16. That is, the resin layer 17 may contain a light-absorbing material. In this case, the transmitted light from the other side can be suppressed. According to such a configuration, since the light transmitted through the multilayer film layer 16 is absorbed by the concavo-convex structure, the transmitted light from the side opposite to the observation surface, that is, the other side can be suppressed, so that the multilayer film layer 16 on the observation side is suppressed. It is suppressed that the light of the wavelength range different from the reflected light from is visually recognized. Therefore, regardless of the difference in the wavelength range of the transmitted light according to the configuration of the multilayer film 16, it is possible to suppress a decrease in the color visibility due to the transmitted light, and the desired color development can be achieved on both sides in the color forming structures 30 and 31. Preferably obtained. The light-absorbing material that absorbs at least part of the transmitted light may be included in the concavo-convex structure on both sides of the base material 15 or may be included only on one side.

[Example of application of coloring structure]
A specific application example of the above-described coloring structure will be described. For the application example described below, any of the coloring structure 30 having the first structure, the coloring structure 31 having the second structure, and the coloring structure 32 described in the above-described modification can be applied. It is.

<Display body>
A first application example of the coloring structure is a form in which the coloring structure is used as a display. The display body may be used for the purpose of increasing the difficulty of counterfeiting the article, may be used for the purpose of improving the design of the article, or may be used for these purposes. For the purpose of increasing the difficulty of counterfeiting goods, for example, the display body is used for authentication documents such as passports and licenses, securities such as gift certificates and checks, cards such as credit cards and cash cards, and banknotes. It is pasted. In addition, for the purpose of improving the design of the article, the display body is, for example, a decorative article worn by the user, an article carried by the user, an article placed like a furniture or a household appliance, a wall or a door. It can be attached to structures, automobile interiors and exteriors.

  As shown in FIG. 8, the display body 40 has a front surface 40F and a back surface 40R that is a surface opposite to the front surface 40F, and the display body 40 has a first surface when viewed from the direction facing the front surface 40F. A display area 41A and a second display area 41B are included. The first display area 41A is an area where a plurality of first pixels 42A are arranged, and the second display area 41B is an area where a plurality of second pixels 42B are arranged. In other words, the first display area 41A is configured by a set of a plurality of first pixels 42A, and the second display area 41B is configured by a set of a plurality of second pixels 42B. Each of the first pixel 42A and the second pixel 42B has a color forming structure, and the first pixel 42A and the second pixel 42B exhibit colors having different hues. That is, when viewed from the direction facing the surface 40F of the display body 40, colors of different hues are visually recognized in the first display area 41A and the second display area 41B.

  Each of the first display area 41A and the second display area 41B represents a character, a symbol, a figure, a pattern, a pattern, a background thereof, or the like by using only these areas or a combination of two or more of these areas. . As an example, in the configuration shown in FIG. 8, a circular graphic is expressed by the first display area 41A, and a triangular graphic is expressed by the second display area 41B.

In addition, the display body 40 is a region having a configuration different from the configuration of the color forming structure around the display regions 41A and 41B, for example, a region having a structure in which a multilayer film layer is laminated on a base material having a flat surface. Or you may have the area | region etc. which have the structure where the metal thin film was laminated | stacked on the base material.
FIG. 9 is a diagram illustrating a cross-sectional structure of the first pixel 42A and the second pixel 42B. FIG. 9 shows an example in which the coloring structure 33 constituting the pixels 42A and 42B and the concavo-convex structure 20 is a coloring structure having the first structure.

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

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

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

  In the above configuration, the height of the uneven structure on the surface of the multilayer film layer 16 is different between the first display area 41A and the second display area 41B, and the display body 40 has a higher height than when the height is constant. Since the uneven structure in the whole is complicated, the uneven structure may be deformed. Therefore, the uneven structure of the multilayer film layer 16 may be protected by a protective layer.

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

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

  When manufacturing the pixels 42A and 42B, for example, after forming convex portions according to a pattern composed of a plurality of rectangles R in a large area, the convex portions are cut so as to divide the pattern. The concavo-convex structure of each pixel 42A, 42B may be formed by dividing by, for example. Such a manufacturing method is preferable because the manufacturing process becomes easy.

  Here, due to the division of the convex portion, the length d2 in the second direction Dy is greater than the length d1 in the first direction Dx at the ends of the pixels 42A and 42B in some of the plurality of pixels 42A and 42B. The convex part which comprises the small rectangle R may be formed. However, even if such a rectangle R is included in the pattern of the convex portions 15a, if the ratio is sufficiently small, the optical influence by the rectangle R is so small that it can be ignored.

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

The multilayer film layer 16 is simultaneously formed in the same process for the portion corresponding to the first display region 41A and the portion corresponding to the second display region 41B. Similarly, a protective layer is formed at the same time for the portions corresponding to the display areas 41A and 41B, and an antireflection layer is also formed at the same time. The antireflection layer is formed, for example, by sputtering or vacuum deposition before or after the formation of the multilayer film layer 16.
When the first display area 41A and the second display area 41B are in contact, each of the multilayer layers 16 is continuous between the first pixel 42A and the second pixel 42B.

  Note that the hues of the first pixel 42A and the second pixel 42B are different from each other because the first pixel 42A and the second pixel 42B have different configurations such as the material and film thickness of the layers constituting the multilayer film layer 16. It is possible by making them different. However, if the structure of the multilayer film layer 16 is different for each of the display regions 41A and 41B, masking of the region and film formation of the high refractive index layer 16a and the low refractive index layer 16b may be repeated for each display region 41A and 41B. This is necessary and 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 structure of the display body 40, it is possible to simultaneously form the multilayer film layer 16 on the portion corresponding to the first display region 41A and the portion corresponding to the second display region 41B. Therefore, the load required for manufacturing the display body 40 is reduced. Further, since it is easy to make the height h1 of the convex portion 15a different for each minute area as compared with the masking to the minute area, the display areas 41A and 41B are made smaller to form a finer image. You can also

  In order to make the first pixel 42A and the second pixel 42B have the same configuration of the multilayer film layer 16 and to change the hue by changing the height h1 of the convex portion 15a, the multilayer film layer 16 is formed as follows. It is preferable to configure as described above. That is, when the multilayer film layer 16 is laminated on a flat surface, the peak wavelength of the reflected light from the multilayer film layer 16 causes the wavelength of the light of the color to be developed in the first pixel 42A and the color in the second pixel 42B. The multilayer film layer 16 is preferably configured so as to be positioned between the hue light wavelength.

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

  Further, when the configuration of the coloring structure 32, that is, the configuration in which the resin layer 17 laminated on the base material 15 has an uneven structure is applied to the configuration of the pixels 42A and 42B, the uneven structure is, for example, It is formed as follows. That is, using the nanoimprint method, a mold in which the height of the unevenness is changed in the portion corresponding to each display region 41A, 41B is used, and the uneven structure of the resin layer 17 of each pixel 42A, 42B is simultaneously formed.

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

  In addition, the number of display areas included in the display body 40, that is, the number of display areas in which pixels composed of the coloring structure are arranged and exhibit colors of different hues is not particularly limited, and the number of display areas is One may be sufficient and three or more may be sufficient. Furthermore, the display area only needs to include a display element composed of a color developing structure, and the display element is not limited to a pixel that is a minimum unit for forming a raster image, but to form a vector image. It may be a region where the anchors are tied.

At this time, the back surface 40R of the display body 40 may be composed of the same color developing structure or different from the front surface 40F as shown in FIG. The rear surface 40R may change the structure with the same regularity as the front surface 40F, or may be independent of the front surface 40F.
The number of display areas in which pixels composed of the coloring structure on the back surface 40R are arranged and exhibit colors of different hues may be one, or may be three or more. Furthermore, the display area only needs to include a display element composed of a color developing structure, and the display element is not limited to a pixel that is a minimum unit for forming a raster image, but to form a vector image. It may be a region where the anchors are tied.
In addition, as the configuration of the display element, any configuration can be applied as long as it is the configuration of the color developing structure described above.

<Coloring sheet and molded body>
A second application example of the coloring structure is a form in which the coloring structure is used for a coloring sheet. The coloring sheet is a sheet composed of a coloring structure, and is fixed to an adherend for decoration or the like. A molded body is composed of the coloring sheet and the adherend. These color-developing sheets and molded articles can also be used for applications utilizing the characteristics of transmitting light other than specific light, such as optical filters and decorations.

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

The film insert method is a method in which an adherend and a color developing sheet are integrated by performing injection molding in a state where a color developing sheet formed by thermal vacuum forming is placed in a mold. The in-mold lamination method is a method in which the production of a coloring sheet by thermal vacuum forming, the formation of an adherend by injection molding, and integration with the coloring sheet are all performed in the same mold. The three-dimensional overlay lamination method is a method in which an adherend and a color developing sheet are integrated using a pressure difference in an airtight space separated from each other by a color developing sheet.
In such a laminate decoration method, a heat treatment, a pressure treatment, or a vacuum treatment is performed, so that a physical or chemical load related to the coloring structure is generated. Therefore, it is preferable that the uneven structure of the multilayer film layer 16 is protected by the protective layer.

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

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

  When the protective layer is laminated, a protective layer having the ability to absorb transmitted light from the multilayer film layer 16 is used. When the coloring sheet is fixed to the resin-made adherend using the laminate decorating method, the protective layer is applied to the concavo-convex structure of the multilayer film layer 16 at the time of heating for integration with the adherend. The followability is preferably high, and from this viewpoint, the protective layer preferably has thermoplasticity. Specifically, if the protective layer has a thermoplastic property at a temperature of 100 ° C. or higher and 160 ° C. or lower, the multilayer film layer 16 can follow the concavo-convex structure when heated in the laminate decoration method. Is preferably obtained. As a thermoplastic resin, the thermoplastic resin illustrated as a material of the above-mentioned base material 15, acrylic resin, urethane, etc. are mentioned, for example.

  The color developing sheet may be provided with an adhesive layer that exhibits an adhesive function instead of the protective layer, and the adhesive layer may be laminated on the protective layer. These protective layers and adhesive layers may be provided on both front and back surfaces, or may be provided on one side. The same layer configuration may be used for the front and back, and different layer configurations may be used.

  When the coloring sheet is fixed to the resin-made adherend using the laminate decoration method, the adhesive layer is developed so that the adhesive layer exhibits an adhesive function when heated for integration with the adherend. Preferably has heat sealability. Examples of the heat sealing agent constituting such an adhesive layer include thermoplastic resins such as polyethylene, polyvinyl acetate, acrylic resin, polyamide, polyester, polypropylene, and polyurethane.

  The adhesive layer is formed using a known coating method such as an inkjet method, a spray method, a bar coating method, a roll coating method, a slit coating method, or a gravure coating method. Although the film thickness of an adhesive layer is not specifically limited, For example, it is preferable that it is a grade of 2 micrometers or more and 200 micrometers or less.

As described above, according to the above embodiment, the following six effects can be obtained.
(1) Since the color developing structure is provided on both sides, different colors can be exhibited on both sides. It is also possible to improve the design by giving different colors to both sides. Furthermore, the light transmitted from the first optical functional layer comprising the first uneven layer and the multilayer film layer thereon, and the second optical function comprising the second uneven layer and the multilayer film layer thereon. The color difference Δab from the reflected light on the layer side, the light transmitted from the second optical functional layer side composed of the second concavo-convex layer and the multilayer film layer thereon, and the first concavo-convex layer and above By setting at least one color difference Δab of the color difference Δab to the reflected light on the first optical functional layer side consisting of the multilayer film layer to 25 or less, the reflected light on the surface to be observed and the other side of the surface to be observed In addition to the fact that the transmitted light from the light has a similar color and the visibility is suppressed from being lowered, the transmitted light from the other side overlaps, so that a desired color can be suitably obtained on both sides.

  (2) By forming the base material 15 from a material that absorbs the transmitted light that has passed through the multilayer film layer 16, the transmitted light from the other side can be suppressed. According to such a configuration, since the light transmitted through the multilayer film layer 16 is absorbed by the base material 15, the transmitted light from the side opposite to the observation surface, that is, the other side can be suppressed. It is suppressed that the light of the wavelength range different from the reflected light from 16 is visually recognized. Accordingly, it is possible to suppress a decrease in the visibility of the color due to the transmitted light, and a desired color development can be suitably obtained on both sides.

(3) In a configuration in which an aluminum thin film layer having a thickness of 1 to 7 nm is included between the concavo-convex structures formed on the substrate, the water vapor transmission rate can be lowered by providing the aluminum thin film layer.
(4) When the concavo-convex structure formed on the base material 15 includes a light-absorbing material that absorbs at least part of the light transmitted through the multilayer film layer 16, the transmitted light from the other side is suppressed. Can do. According to such a configuration, since the light transmitted through the multilayer film layer 16 is absorbed by the concavo-convex structure, the transmitted light from the side opposite to the observation surface, that is, the other side can be suppressed, so that the multilayer film layer 16 on the observation side is suppressed. It is suppressed that the light of the wavelength range different from the reflected light from is visually recognized. Accordingly, it is possible to suppress a decrease in the visibility of the color due to the transmitted light, and a desired color development can be suitably obtained on both sides.

  (5) If there is a protective layer on the first or second multilayer structure, the surface of the multilayer film layer 16 is covered with the protective layer, so that deformation of the concavo-convex structure in the multilayer film layer 16 or clogging of the concavo-convex structure is prevented. Can be suppressed. Therefore, it is possible to suppress the change in the optical path length of the light reflected by the multilayer film layer 16 and the decrease in the diffusion effect and diffraction effect of the reflected light due to the concavo-convex structure. Is obtained. Further, since the protective layer is directly laminated on the multilayer film layer 16, the manufacturing process is simplified, and the manufacturing cost is increased and the yield is reduced as compared with the configuration in which the protective layer is provided via an adhesive layer or the like. Is suppressed.

  (6) According to the manufacturing method in which the concavo-convex structure of the concavo-convex layer is formed using the nanoimprint method, a fine concavo-convex structure can be suitably and simply formed. If the nanoimprint method is a manufacturing method in which an optical nanoimprint method or a thermal nanoimprint method is used, formation of a concavo-convex structure by the nanoimprint method can be realized suitably and simply.

[Modification]
The above embodiment can be implemented with the following modifications.
In the color forming structure, a layer having a light absorption property that absorbs at least a part of the light transmitted through the multilayer film layer 16 among the incident light may be laminated on the base material 15. By constituting the material that absorbs the transmitted light transmitted through the multilayer film layer 16, the transmitted light from the other side can be suppressed. According to such a configuration, since the light transmitted through the multilayer film 16 is absorbed by the absorption layer, the transmitted light from the side opposite to the observation surface, that is, the other side can be suppressed. It is suppressed that the light of the wavelength range different from the reflected light from 16 is visually recognized. Accordingly, it is possible to suppress a decrease in the visibility of the color due to the transmitted light, and a desired color development can be suitably obtained on both sides. However, since the coating process is increased as compared with the case where the substrate 15 and the concavo-convex structure have light absorption, there is a concern that the cost may increase.

  The color developing structure may include a layer having ultraviolet absorptivity as a layer different from the protective layer. For example, the color forming structure may include a base material 15 and a layer containing an ultraviolet absorber on the base material 15. With such a configuration, it is possible to obtain a high effect of suppressing deterioration of the material constituting the color forming structure by ultraviolet rays.

  The pixels included in the display body 40 may include pixels in which the extending direction of the uneven structure in the uneven layer is different from each other on the virtual plane. Specifically, the second direction Dy, which is the direction in which the convex portion extends in any pixel, and the second direction Dy, which is the direction in which the convex portion extends in a pixel different from this pixel, are different directions. For example, a configuration in which these directions are orthogonal to each other may be used. According to such a configuration, the direction in which the reflected light from the multilayer film 16 is diffused can be changed depending on the pixel, and various images can be expressed.

  In addition, since the multilayer film layer 16 is also formed on the side surface of the convex portion in the concave-convex layer, the width of the convex portion of the concave-convex structure in the multilayer film layer 16 is slightly wider than the width of the convex portion in the concave-convex layer. In the portion where the pixels having different concavo-convex structure extending directions are adjacent to each other, the expanded portions of the multilayer film layer 16 as described above are connected between the convex portions having different extension directions, and the concavo-convex structure in the multilayer film layer 16 collapses. When this occurs, it is difficult to obtain a desired color from each pixel in a desired direction. For this reason, it is preferable that a region where the unevenness is not formed is provided between the pixels in which the extending direction of the uneven structure is different from each other. Further, even between pixels having the same concavo-convex structure in the extending direction, a region in which the concavo-convex layer is not formed may be provided in the concavo-convex layer. The collapse of the structure is suppressed at the end of the pixel, and a desired color can be easily obtained from the entire pixel. The width of the region where the unevenness provided between the pixels is not formed is preferably, for example, 1/2 or more of the film thickness of the multilayer film layer 16.

  -The convex part which comprises the uneven structure of an uneven | corrugated layer may have a structure where the width | variety of the 1st direction Dx becomes small gradually toward a top part from a base. According to such a configuration, the multilayer film layer 16 is easily formed on the convex portion. In this case, the length d1 and the length d3 in the first direction Dx are defined by a pattern formed by the bottom surface of the convex portion.

  A pattern formed by the projection image of the projections 15a and / or projections 15x is formed by the first structure of the projection / depression structure in the projection / depression layer, and a projection image of the first projection element 15Ea is formed by the second structure. The figure constituting the pattern is not limited to a rectangle. The figure constituting these patterns may be an ellipse or the like. In short, the figure may be a graphic element having a shape whose length along the second direction Dy is equal to or greater than the length along the first direction Dx. That's fine. The length d1 in the first direction Dx and the length d2 in the second direction Dy of the graphic element only need to satisfy the various conditions described in the description of the first structure.

  The outermost layer in the multilayer film layer 16, that is, the layer constituting the outermost surface on the opposite side to the uneven layer in the multilayer film layer 16 may function as a protective layer. In this case, the multilayer film layer 16 is an optical functional layer. The layer functioning as the protective layer only needs to be able to suppress, in at least one aspect, changes that make it difficult to obtain a desired color in the color forming structure, such as deformation or alteration of the uneven structure in the lower layer than the protective layer. .

  Specifically, the outermost layer in the multilayer film layer 16 functions as a protective layer by having characteristics different from those of the multilayer film layer 16 other than the outermost layer. Such characteristics may be structural characteristics, chemical characteristics, or physical characteristics, such as hardness, thickness, uneven height, water repellency, and the like. For example, if the outermost layer is harder than the other layers, or if the outermost layer is thicker than the other layers, the outermost layer is more resistant to impact than the other layers. The concavo-convex structure in the lower layer is protected. Further, if the height of the unevenness in the outermost layer is smaller than that of the other layers, that is, if the flatness in the outermost layer is higher than that of the other layers, the height of the unevenness on the surface of the multilayer film layer 16 is reduced. As a result, it becomes difficult for the impact to cause deformation of the unevenness, so that the uneven structure below the outermost layer is protected.

  Even if the outermost layer in the multilayer film layer 16 has different characteristics from the layers other than the outermost layer, the entire multilayer film layer 16 has a surface shape that follows the concavo-convex structure of the concavo-convex layer, that is, the concavo-convex structure. The multilayer film layer 16 has projections and depressions corresponding to the arrangement of the projections and depressions in the layer depression and projection structure, and the reflectance of light in a specific wavelength region of incident light incident on the multilayer film layer 16 has other wavelengths. It is configured to be higher than the reflectance of light in the region.

[Example]
The color developing structure and the manufacturing method thereof will be described using specific examples.
<Example 1>
Example 1 is a coloring sheet to which the coloring structure is applied, and a molded body using the coloring sheet. The color developing sheet of Example 1 has a color structure in which a concavo-convex structure of the first structure is formed on the resin layer on the front surface of the substrate exhibiting light absorption and a concavo-convex structure of the second structure is formed on the resin layer on the back surface. Consists of structures.

  First, a mold 1 which is an intaglio used in the optical nanoimprint method was prepared. Specifically, since light having a wavelength of 365 nm was used as light to be irradiated in the optical nanoimprint method, synthetic quartz that transmits light having this wavelength was used as a mold material. In forming the mold, first, a film made of chromium (Cr) was formed on the surface of the synthetic quartz substrate by sputtering, and an electron beam resist pattern was formed on the Cr film by electron beam lithography. The formed pattern is a pattern composed of a set of a plurality of rectangles shown in FIG.

  The pixel region is a square having a side of 130 mm, the length of the rectangle in the first direction is 380 nm, and the length of the rectangle in the second direction is a normal value having an average value of 2400 nm and a standard deviation of 580 nm. The length selected from the distribution. In the pattern, the plurality of rectangles are arranged so as not to overlap in the first direction. The resist used was a positive type, and the film thickness was 200 nm.

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

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

Subsequently, the synthetic quartz wafer was etched by plasma using O ₂ gas to remove the photocurable resin remaining in the concave portion of the concave-convex structure. In this step, 40 sccm of O ₂ gas was introduced to cause plasma discharge. Next, etching using plasma using a mixed gas of octafluorocyclobutane (C ₄ F ₈ ) and argon (Ar) was performed, and the uneven structure of the resin layer was transferred to a synthetic quartz wafer. In this step, 40 sccm of C ₄ F ₈ gas and 60 sccm of Ar gas were introduced, the pressure in the plasma chamber was set to 5 mTorr, and then plasma discharge was performed by applying RIE power 75 W and ICP power 400 W. The height of the convex part in the concavo-convex structure formed on the synthetic quartz wafer was 100 nm.

  Next, organic cleaning using a mixed solution of dimethyl sulfoxide: monoethanolamine = 7: 3 (ST-105, manufactured by Kanto Chemical), and a mixed aqueous solution (SH-303) containing sulfuric acid and hydrogen peroxide as basic components , Manufactured by Kanto Chemical Co., Ltd.) to obtain a mold 1 which is a base material having an uneven structure as the first structure.

  Next, a mold 2 which is an intaglio used in the optical nanoimprint method was prepared. Specifically, since light having a wavelength of 365 nm was used as light to be irradiated in the optical nanoimprint method, synthetic quartz that transmits light having this wavelength was used as a mold material. In forming the mold, first, a film made of chromium (Cr) was formed on the surface of the synthetic quartz substrate by sputtering, and an electron beam resist pattern was formed on the Cr film by electron beam lithography. The formed pattern is a pattern composed of a set of a plurality of rectangles shown in FIG. The length of the rectangle in the first direction is 300 nm, and the length of the rectangle in the second direction is a length selected from a normal distribution having an average value of 2000 nm and a standard deviation of 500 nm. In the pattern, the plurality of rectangles are arranged so as not to overlap in the first direction. The resist used was a positive type, and the film thickness was 200 nm.

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

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

Subsequently, the Cr film in the region exposed from the resist was etched by plasma generated by applying a high frequency to a mixed gas of chlorine (Cl ₂ ) and oxygen (O ₂ ). Subsequently, the synthetic quartz substrate in the region exposed from the resist and the Cr film was etched by plasma generated by applying a high frequency to hexafluoroethane gas. The depth of the etched synthetic quartz substrate was 65 nm. After removing the remaining resist and Cr film, OPTOOL HD-1100 (manufactured by Daikin Industries) was applied as a mold release agent to the surface of the synthetic quartz substrate. Thereby, the mold 2 in which the uneven structure corresponding to the second structure was formed was obtained.

  Next, corona treatment is applied to both sides of the black polyester film (Lumirror X30, manufactured by Toray Industries, Inc.), and a photocurable resin (PAK-02, manufactured by Toyo Gosei Co., Ltd.) is applied to one surface of the black polyester film. The surface on which is formed was pressed and irradiated with 365 nm light from the back side of the mold. After curing the photocurable resin by this light irradiation, the polyester film and the resin layer were peeled from the mold. Thereby, the polyester film which is a base material with which the resin layer which has the uneven structure of the 1st structure was laminated | stacked was obtained.

A TiO ₂ film as a high refractive index layer having a film thickness of 205 nm and a low refractive index layer having a film thickness of 100 nm are formed on the uneven surface of the laminate of the base material and the resin layer by vacuum deposition. SiO ₂ films were alternately formed to form a multi-layer film having 5 sets of high refractive index layers and low refractive index layers, that is, 10 layers.

  Next, a photo-curing resin (PAK-02, manufactured by Toyo Gosei Co., Ltd.) is applied to a surface different from the surface subjected to the first structure, and the surface on which the unevenness of the mold 2 is formed is pressed on this resin. Then, 365 nm light was irradiated from the back side of the mold. After curing the photocurable resin by this light irradiation, the polyester film and the resin layer were peeled from the mold. Thereby, the polyester film which is a base material with which the resin layer which has the uneven structure of a 2nd structure was laminated | stacked was obtained.

Next, a TiO ₂ film as a high refractive index layer having a film thickness of 40 nm and a low film thickness of 75 nm are formed by vacuum deposition on the uneven surface of the laminate of the obtained base material and resin layer. The SiO ₂ films as the refractive index layers were alternately formed to form five sets of high refractive index layers and low refractive index layers, that is, a multilayer film having 10 layers.
As a result, when observed from the side having the concavo-convex structure of the first structure, green was confirmed with good visibility. When observed from the side having the concavo-convex structure of the second structure, a glossy blue color was confirmed with good visibility.

<Example 2>
Example 2 is a coloring sheet to which the coloring structure is applied, and a molded body using the coloring sheet. The color developing sheet of Example 2 is a color developing structure in which the color difference Δab between the light transmitted from one surface and the reflected light from the other surface is 25 or less.

  First, a mold 3 which is an intaglio used in the optical nanoimprint method was prepared. Specifically, since light having a wavelength of 365 nm was used as light to be irradiated in the optical nanoimprint method, synthetic quartz that transmits light having this wavelength was used as a mold material. In forming the mold, first, a film made of chromium (Cr) was formed on the surface of the synthetic quartz substrate by sputtering, and an electron beam resist pattern was formed on the Cr film by electron beam lithography. The formed pattern is a pattern composed of a set of a plurality of rectangles shown in FIG.

  The area to be a pixel is a square having a side of 130 mm, the length of the rectangle in the first direction is 460 nm, and the length of the rectangle in the second direction is a normal value having an average value of 2400 nm and a standard deviation of 580 nm. The length selected from the distribution. In the pattern, the plurality of rectangles are arranged so as not to overlap in the first direction. The resist used was a positive type, and the film thickness was 200 nm.

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

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

Subsequently, the synthetic quartz wafer was etched by plasma using O ₂ gas to remove the photocurable resin remaining in the concave portion of the concave-convex structure. In this step, 40 sccm of O ₂ gas was introduced to cause plasma discharge. Next, etching using plasma using a mixed gas of octafluorocyclobutane (C ₄ F ₈ ) and argon (Ar) was performed, and the uneven structure of the resin layer was transferred to a synthetic quartz wafer. In this step, 40 sccm of C ₄ F ₈ gas and 60 sccm of Ar gas were introduced, the pressure in the plasma chamber was set to 5 mTorr, and then plasma discharge was performed by applying RIE power 75 W and ICP power 400 W. The height of the convex part in the concavo-convex structure formed on the synthetic quartz wafer was 200 nm.

  Next, organic cleaning using a mixed solution of dimethyl sulfoxide: monoethanolamine = 7: 3 (ST-105, manufactured by Kanto Chemical), and a mixed aqueous solution (SH-303) containing sulfuric acid and hydrogen peroxide as basic components. , Manufactured by Kanto Chemical Co., Ltd.) to obtain a mold 3 which is a base material having an uneven structure as the first structure.

  Next, a photocurable resin (PAK-02, manufactured by Toyo Gosei Co., Ltd.) is applied to the surface of the polyester film (Cosmo Shine A4300, manufactured by Toyobo Co., Ltd.) subjected to easy adhesion treatment on both sides, The surface of the mold 3 on which the unevenness was formed was pressed against this resin and irradiated with 365 nm light from the back side of the mold. After curing the photocurable resin by this light irradiation, the polyester film and the resin layer were peeled from the mold. Thereby, the polyester film which is a base material with which the resin layer which has the uneven structure of the 1st structure was laminated | stacked was obtained.

A TiO ₂ film as a high refractive index layer having a film thickness of 80 nm and a low refractive index layer having a film thickness of 110 nm are formed on the uneven surface of the laminate of the base material and the resin layer by vacuum deposition. SiO ₂ films were alternately formed to form a multilayer film layer having 6 sets of high refractive index layers and low refractive index layers, that is, 12 layers.

  Next, a photo-curing resin (PAK-02, manufactured by Toyo Gosei Co., Ltd.) is applied to a surface different from the surface subjected to the first structure, and the surface on which the unevenness of the mold 2 is formed is pressed on this resin. Then, 365 nm light was irradiated from the back side of the mold. After curing the photocurable resin by this light irradiation, the polyester film and the resin layer were peeled from the mold. Thereby, the polyester film which is a base material with which the resin layer which has the uneven structure of a 2nd structure was laminated | stacked was obtained.

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

  As a result, when observed from the side having the concavo-convex structure of the first structure, red was confirmed with good visibility. When observed from the side having the concavo-convex structure of the second structure, a glossy blue color was confirmed with good visibility. At this time, the color difference Δab between the light transmitted from the side where red is visually recognized and the reflected light of the surface where blue is visible is 25.

  Dx ... first direction, Dy ... second direction, 10, 11, 12, 20, 21 ... concavo-convex structure, 15 ... base material, 15a, 15c, 15x ... convex part, 15b, 15y ... concave, 15Ea ... first convex element, 15Eb ... second convex element, 16 ... multilayer film layer, 16a ... high refractive index layer, 16b ... low Refractive index layer, 17 ... resin layer, 18 ... aluminum thin film layer, 30, 31, 32, 33, 34 ... coloring structure, 40 ... display body, 40F ... surface, 40R. ..Back side, 41A, 41B ... display area, 42A, 42B ... pixel

Claims (10)

A substrate, a first uneven layer having a concavo-convex structure formed on the substrate surface or the substrate, and a concavo-convex structure formed on a surface of the substrate opposite to the first concavo-convex layer. A second concavo-convex layer, and a multilayer film layer disposed on the concavo-convex structure of the first concavo-convex layer and the concavo-convex structure of the second concavo-convex layer, and having a surface shape following these concavo-convex structures, Prepared,
Among the plurality of layers of the multilayer film layer, the refractive indexes of mutually adjacent layers are different from each other, and the reflectance of light in a specific wavelength region of incident light incident on the multilayer film layer is other wavelength region. Higher than the reflectance of light at
A virtual plane that is a virtual plane on which the concavo-convex structure is projected in the thickness direction of the first concavo-convex layer and the second concavo-convex layer, with the first direction and the second direction orthogonal to the first direction. The direction included in the plane,
The convex portion constituting the concavo-convex structure has a convex shape of one or more steps, and the pattern formed by the projected image of the convex portion projected onto the virtual plane has a length along the second direction. Including a pattern composed of a set of a plurality of graphic elements having a length equal to or longer than one direction,
The length along the first direction of the graphic element is equal to or less than the sub-wavelength, and the standard deviation of the length along the second direction in the plurality of graphic elements is the length along the first direction. Color development structure larger than the standard deviation of.   Light transmitted from the side of the first optical functional layer composed of the first concavo-convex layer and the multilayer film layer thereon, and the second optical function composed of the second concavo-convex layer and the multilayer film layer thereon. The color difference Δab from the reflected light on the layer side, the light transmitted from the second optical functional layer comprising the second uneven layer and the multilayer film thereon, the first uneven layer, 2. The color developing structure according to claim 1, wherein at least one color difference Δab of the color difference Δab with respect to the reflected light on the side of the first optical functional layer made of the multilayer film thereon is 25 or less.   3. The color developing structure according to claim 1, wherein the base material has a light absorptivity that absorbs at least a part of the light transmitted through the multilayer film layer in the incident light.   The aluminum thin film layer with a thickness of 1 nm or more and 7 nm or less is disposed between at least one of the first uneven layer and the second uneven layer and the base material. Coloring structure.   5. The method according to claim 1, wherein at least one of the first uneven layer and the second uneven layer contains a light-absorbing material that absorbs at least part of light transmitted through the multilayer film layer. The color developing structure according to one item.   The color developing structure according to claim 1, further comprising a protective layer on the multilayer film layer.   It is a method of manufacturing the coloring structure according to any one of claims 1 to 6, wherein at least one of the uneven structure of the first uneven layer and the uneven structure of the second uneven layer is optically imprinted. Method for producing a coloring structure produced by a method or a thermal imprint method.   A display body comprising the color developing structure according to claim 1.   A coloring sheet provided with the coloring structure according to claim 1.   A molded body comprising the color developing sheet according to claim 9.

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