JP2022102879A - Display body - Google Patents

Abstract

To provide a display body having a small change in color due to an observation angle while suppressing an uneven structure and peeling of a multilayer film interface.SOLUTION: A display body has an uneven layer having an uneven structure, and a multilayer film layer having a surface shape following the uneven structure and having and made of two or more layers. The multilayer film layer is mutually different in index of refraction between adjacent layers, and the uneven structure is made of a first structure provided with a plurality of concave portions contributing to scattering and a second structure provided with at least one concave portion for suppressing peeling. A pattern that the first concave portion forms includes a pattern composed of a plurality of pattern elements having a length of a side along a first direction of a sub wavelength or shorter and a length of a side along a second direction equal to or more than the length along the first direction. In the plurality of pattern elements, a standard deviation of the length of the side along the second direction is larger than the standard deviation of the length of the side along the first direction, a depth of a second concave portion is larger than the depth of the first concave portion, and at least a portion of a long side constituting the first concave portion intersects with the second concave portion.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a display body.

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

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

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

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

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

Japanese Unexamined Patent Publication No. 2005-153192

By the way, the structural color by the above-mentioned structure can realize a visual effect different from the dye color. For example, in the structure of Patent Document 1, the convex portion of the concave-convex structure has a rectangular shape extending in a common direction in each convex portion when viewed from the direction facing the surface on which the unevenness is formed (for example, the upper side). Moreover, the length of the convex portion in the long side direction is irregular. On the other hand, the length of the convex portion in the short side direction is almost constant. That is, the long side direction of the plurality of convex portions has anisotropy, and as a result, the direction in which the reflected light spreads also has anisotropy. Therefore, it is possible to produce a highly designed display body having a different appearance depending on the observation angle.

The uneven structure of Patent Document 1 has a rectangular shape and has many edge portions. Since a very large shear stress is concentrated on the edge portion, peeling is likely to occur. The uneven structure has a rectangular shape having a long side and a short side, and in particular, when peeling is performed in the long side direction and cracks are formed, the peeling region becomes large. When the uneven structure and the multilayer film are peeled off, the optical path length of the light reflected by the multilayer film changes, and the effect of diffusing the reflected light in multiple directions is reduced, so that it becomes difficult to obtain the desired color on the display body. ..

The present invention has been made in view of such circumstances, and by providing a structure having a long axis in the direction intersecting the long side direction of the concave-convex structure, the peeling region is reduced, and the concave-convex structure and the interface between the multilayer film are provided. The purpose is to improve the adhesion.

In order to solve the above problems, the display body according to one aspect of the present disclosure includes a concavo-convex layer having an concavo-convex structure, a multilayer film layer having a surface shape following the concavo-convex structure and composed of two or more layers. Equipped with
The multilayer film layer has different refractive indices from each other, and the uneven structure has a first structure having a plurality of recesses contributing to scattering and a second structure having at least one recess for suppressing peeling. The pattern formed by the first concave portion constituting the first structure, which is composed of a structure and is viewed from a viewpoint facing the surface of the uneven layer, has a side length along the first direction of sub-wavelength or less. The plurality of figures include a pattern consisting of a set of a plurality of graphic elements in which the length of the side along the second direction intersecting the first direction is equal to or larger than the length of the side along the first direction. In the element, the standard deviation of the length of the side along the second direction is larger than the standard deviation of the length of the side along the first direction, and the depth of the second recess constituting the second structure is large. It is characterized in that the second recess intersects at least a part of the long side constituting the first recess when viewed from a viewpoint facing the surface of the uneven layer, which is deeper than the depth of the first recess.

When viewed from the viewpoint facing the surface of the uneven layer, the pattern formed by the second recess has a side length along the first direction in the first direction of the pattern formed by the first recess. It is longer than the length of the side along the line and is characterized by intersecting the pattern formed by the first recess.

The length of the side of the second recess along the second direction is 1/4 or less of the length of the side of the first recess along the first direction.

The depth of the recess of the second structure is 200 nm or more and 500 nm or less.

When the second structure is viewed from the direction facing the surface, the ratio of the second recess to the region constituting the uneven layer is 10% or more and 30% or less.

The length of the side of the first recess along the first direction is 830 nm or less.

The average value of the lengths of the sides of the first recess along the second direction is 4.15 μm or less, and the standard deviation of the length is 1 μm or less.

When the first structure is viewed from the direction facing the surface of the uneven layer, the first concave portion occupies 40% or more and 60% or less in the region constituting the uneven layer. do.

The first structure is characterized in that it includes display regions in which the structural depths of the first recesses are different, and the difference is 5 nm or more and 200 nm or less.

The first structure is characterized in that the depth of the first recess is constant within each display area.

Of the multilayer film layers, two layers adjacent to each other above and below are characterized in that they transmit light in the same wavelength region and are composed of materials having different refractive indexes in the wavelength region.

The uneven structure is formed on one surface side of the base material, and is formed.
The substrate is characterized by being formed of a material that absorbs light in the visible light wavelength region.

The uneven structure is formed on one surface side of the base material, and is formed.
It is characterized in that the back surface opposite to one surface of the substrate is formed of a material that absorbs light in the visible light wavelength region.

According to the present invention, the long side direction of the first structure is irregularly divided by the second structure, and it is possible to reduce the peeling region. Further, by increasing the depth of the second structure, the surface area can be increased and the adhesion can be improved.

It is sectional drawing which shows typically one structural example of the display body which concerns on 1st Embodiment. It is a top view explaining the surface structure of the display body which concerns on 1st Embodiment. It is a top view explaining the surface structure of the 1st structure which concerns on 1st Embodiment. It is a top view explaining the surface structure of the 2nd structure which concerns on 1st Embodiment. It is sectional drawing which shows the structural example of the display body which concerns on 2nd Embodiment.

An embodiment of the present disclosure will be described with reference to the drawings.
Here, the configuration shown in the drawings is schematic, and the relationship between the thickness and the plane dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Further, the embodiments shown below exemplify a configuration for embodying the technical idea of the present disclosure, and the technical idea of the present disclosure includes the following materials, shapes, structures, etc. of the constituent parts. It is not limited to things. The technical idea of the present disclosure may be modified in various ways within the technical scope specified by the claims described in the claims.

<First Embodiment>
(Structure of display)
The basic configuration of the display body according to the first embodiment of the present disclosure will be described with reference to FIG. FIG. 1 is a cross-sectional view for explaining a configuration example of the display body 10 according to the first embodiment of the present disclosure.
As shown in FIG. 1, the display body 10 according to the embodiment of the present disclosure includes a concavo-convex layer having a concavo-convex structure 13 and a multilayer film layer 14 having a surface shape following the concavo-convex structure 13. Further, the uneven structure 13 has a first structure and a second structure. Hereinafter, each layer will be described in detail.

(Multilayer film layer)
The multilayer film layer 14 is a layer formed on the uneven layer, and is composed of two or more layers. In the multilayer film layer 14, the refractive indexes of adjacent layers are different from each other. The multilayer film layer 14 of the present embodiment has a structure in which the high refractive index layer 12 and the low refractive index layer 11 are alternately laminated. The refractive index of the high refractive index layer 12 is larger than that of the low refractive index layer 11. Further, the multilayer film layer 14 is laminated following the uneven shape of the concave-convex structure 13, and convex portions and concave portions of each display element are formed. The structure of the multilayer film layer 14, that is, the material, the film thickness, and the stacking order of each layer constituting the multilayer film layer 14 are the same on the convex portion and the concave portion in the concave-convex structure 13.

When light is incident on the multilayer film layer 14, the light reflected at each interface between the high refractive index layer 12 and the low refractive index layer 11 in the multilayer film layer 14 causes interference, and the light reflected on the outermost surface of the multilayer film layer 14 is not present. The direction of travel is changed due to regular unevenness. As a result, light in a specific wavelength range is emitted at a wide angle. The specific wavelength range strongly emitted as the reflected light is determined by the material and film thickness of the high refractive index layer 12 and the low refractive index layer 11, and the width, height, and arrangement of the unevenness. Hereinafter, the high refractive index layer 12 and the low refractive index layer 11 will be described.

The high refractive index layer 12 and the low refractive index layer 11 are composed of a material that transmits light in the visible region, that is, a material that is transparent to light in the visible region. As long as the refractive index of the high refractive index layer 12 is higher than the refractive index of the low refractive index layer 11, the material of these layers is not limited, but the refractive index of the high refractive index layer and the low refractive index layer is not limited. The larger the difference, the higher the intensity of reflected light can be obtained with a smaller number of layers. From this point of view, for example, when the high refractive index layer 12 and the low refractive index layer 11 are made of an inorganic material, the high refractive index layer 12 is made of titanium dioxide (TIM ₂ ) and the low refractive index layer 11 is made of silicon dioxide. It is preferably composed of (SiO ₂ ). However, each of the high refractive index layer 12 and the low refractive index layer 11 may be made of an organic material.

The film thickness of each of the high refractive index layer 12 and the low refractive index layer 11 may be designed by using a transfer matrix method or the like according to a desired color to be developed on the display body. For example, in the case of a display body exhibiting blue, the film thickness of the high refractive index layer 12 made of TiO ₂ is preferably about 40 nm, and the film thickness of the low refractive index layer 11 made of SiO ₂ is about 75 nm. Is preferable.

(Concave and convex layer)
The uneven layer has an uneven structure 13 formed on one surface side of the base material. As shown in FIG. 1, the concavo-convex structure 13 may be formed on one surface side of the base material, and the base material constituting the concavo-convex layer may be formed of a material that absorbs light in the visible light wavelength region. At least a part of the light transmitted through the multilayer film layer 14 is absorbed by the uneven layer constituting the absorption layer, and the transmitted light is suppressed from returning to the first surface side (upper surface side in FIG. 1). Therefore, when the display body is observed from the surface having the uneven layer, the light in the wavelength range different from the light reflected from the multilayer film layer 14 is suppressed from being visually recognized, so that the visibility of the color due to the reflected light is deteriorated. It is possible to suppress.
Further, the concave-convex structure 13 may be formed on one surface side of the base material, and the back surface opposite to one surface of the base material may be formed of a material that absorbs light in the visible light wavelength region.

When the concave-convex structure is directly formed on the base material as in the concave-convex structure 13 shown in FIG. 1 (a), known techniques such as electron beam, ultraviolet lithography, and dry etching may be used.

The uneven structure 13 includes a first structure having a plurality of recesses contributing to scattering and a second structure having at least one recess for suppressing peeling. In the present embodiment, the first structure includes the first recess 22. The first recess 22 has a stepped shape of one or more steps from the plane on which the base of the first recess 22 is located. Further, in the present embodiment, the second structure includes the second recess 23. The second recess 23 has a stepped shape of one or more steps from the plane on which the base of the second recess 23 is located.
When viewed from the viewpoint facing the surface of the uneven layer, the second concave portion intersects at least a part of the long side constituting the first concave portion 22.

Here, with reference to FIG. 2, the details of the concavo-convex structure 13 formed in the concavo-convex layer made of the base material will be described. FIG. 2A is a plan view of the base material as viewed from a direction facing the surface (thickness direction), and FIG. 2B is a base material along the line II-II of FIG. 2A. It is a figure which shows the cross-sectional structure of.

As shown in FIG. 2A, the first recess 22 and the second recess 23, which are display patterns, are formed from a plurality of graphic elements S extending in the first direction Dx and a plurality of graphic elements R extending in the second direction Dy. It is composed. The first direction Dx and the second direction Dy are directions included in the plane along the sides of the graphic elements S and R, and the first direction Dx and the second direction Dy intersect with each other. In this embodiment, the first direction Dx and the second direction Dy are orthogonal to each other. By making the first direction Dx and the second direction Dy orthogonal to each other, the peeling region of the first structure can be reduced.

As shown in FIG. 2B, the depth of the first recess 22 constituting the pattern consisting of the set of graphic elements R is h2, and the depth of the second recess 23 forming the pattern consisting of the set of graphic elements S is h2. Let it be h3. At this time, the depth h1 of the overlapping portion 21 of the first recess and the second recess, which is the region where the graphic elements R and S overlap, is the depth h2 of the first recess 22 and the depth h3 of the second recess 23. Is the sum of. Further, the depth h2 of the first recess 22 and the depth h3 of the second recess 23 may be constant.
According to the above configuration, the effect of diffusing the reflected light is obtained by the convex portions constituting the concave-convex structure 13, and the light in a specific wavelength range is observed at a wide angle as the reflected light from the multilayer film layer. Further, the irregularly provided overlapping portion 21 of the first recess and the second recess suppresses peeling in the Dy direction, and the depth h1 of the overlapping portion 21 of the first recess and the second recess is the depth of the first recess 22. The adhesion is further improved by increasing the area of the side wall deeper than the depth h3 of the h2 and the second recess 23.

3 (a) and 3 (b) are a plurality of the uneven structures shown in FIGS. 2 (a) and 2 (b) when the base material is viewed from the direction facing the surface (thickness direction). It is a figure which showed only the 1st pattern 30 which consists of the set of the graphic element R of. FIG. 3A is a plan view of the first structure and the base material as viewed from a direction facing the surface (thickness direction), and FIG. 3B is a line III-III of FIG. 3A. It is a figure which shows the 1st structure and the cross-sectional structure of a base material along with. The length d1 of the side of the plurality of graphic elements R along the first direction Dx is constant. When reflecting light in the visible region, d1 is preferably 830 nm or less, and for example, when it is a blue display element, it is preferably about 300 nm.

On the other hand, in the plurality of graphic elements R, the standard deviation of the length d2 along the second direction Dy is preferably larger than the standard deviation of the length of the sides along the first direction. The reason is that the variation in the length of the side along the first direction or the length of the straight line passing through the center and along the first direction becomes large, so that the reflected light is scattered in all directions in two dimensions and the reflectance is increased. This is to prevent a decrease. In order to efficiently scatter the reflected light from the multilayer film layer 14, the length d2 of the sides of the plurality of graphic elements R along the second direction Dy has an average value of 4.15 μm or less and a standard deviation of 4.15 μm or less. It preferably has a distribution of 1 μm or less. When the average value of the length d2 is 4.15 μm or less, the reflected light from the multilayer film layer 14 can be efficiently scattered. When the standard deviation of the length d2 is 1 μm or less, it becomes easy to develop a specific color by suppressing the variation of the length d2.

The depth h2 of the first recess 22 may be designed to an appropriate height according to the wavelength of the light reflected on the surface of the display body. If the value of the depth h2 of the first recess 22 is higher than the surface roughness of the multilayer film layer described later, a diffraction effect can be obtained. However, if the depth h1 of the overlapping portion 21 of the first recess and the second recess is excessively increased, the scattering effect is strengthened and the saturation of the light reflected from the surface of the multilayer film is impaired, so that the target wavelength band is visible. In the case of the display body of the region, the value of the depth h2 of the first recess 22 is preferably 415 nm or less. The value of the depth h2 of the first recess 22 is more preferably in the range of 10 nm or more and 200 nm or less.
For example, in a blue display body, the value of the depth h2 of the first recess 22 is preferably 40 nm or more and 150 nm or less in order to obtain an effective light spread. In order to control the scattering effect of the reflected light, it is more preferable that the depth h2 of the first recess 22 is 100 nm or less in the blue display body.

Further, the depth h2 of the first recess 22 may be constant in each display area, and may be different for each display area. When the structural depths of the first recesses 22 of the pattern composed of the plurality of graphic elements R are different in each display region, the difference is preferably 5 nm or more. The upper limit is 200 nm or less. When the difference in the structural depth of the first recess 22 is 5 nm or more, it becomes easy to recognize the color of each display area. If the structural depth becomes excessively large, the scattering effect of the reflected light becomes too high and the intensity of the reflected light becomes weak.

Further, it is preferable that the ratio of the first concave portion 22 constituting the pattern composed of a set of a plurality of graphic elements R in the region constituting the concave-convex layer is 40% or more and 60% or less. More preferably, the ratio of the first recess 22 in the region constituting the uneven layer is preferably 50%. In order to increase the spread of the reflected light from the multilayer film layer, that is, to enhance the scattering effect of the reflected light, it is preferable that the unevenness is 40% or more. Further, when the ratio occupied by the first recess 22 is 60% or less, the visibility is improved.

4 (a) and 4 (b) are views of the concave-convex structure 13 shown in FIGS. 2 (a) and 2 (b) when the base material is viewed from the direction facing the surface (thickness direction). It is a figure which showed only the 2nd pattern which consists of the set of a plurality of graphic elements S. 4 (a) is a plan view of the second structure and the base material as viewed from the direction facing the surface (thickness direction), and FIG. 4 (b) is the IV-IV line of FIG. 4 (a). It is a figure which shows the 2nd structure and the cross-sectional structure of a base material along with. The plurality of graphic elements S are in a positional relationship intersecting with the plurality of graphic elements R. In the present embodiment, the plurality of graphic elements S are orthogonal to the plurality of graphic elements R. Thereby, the peeling region of the first structure can be reduced.

The length d3 of the side of the plurality of graphic elements S along the Dx direction is longer than the length d1 of the side of the plurality of graphic elements R along the Dx direction. The second pattern composed of the plurality of graphic elements S intersects with the first pattern, and irregularly divides the side length d2 of the plurality of graphic elements R along the Dy direction to form the graphic elements. It is possible to release the shear stress along the Dy direction of R and reduce the peeling.

The length d4 of the side of the plurality of graphic elements S along the second direction Dy is 1/4 or less of the length d1 of the plurality of graphic elements R along the Dx direction. When the length d4 is 1/4 or less of the length d1, the scattering effect of the reflected light can be controlled and the visibility can be improved. The length d1 is preferably 830 nm or less, and for example, about 300 nm is preferable when the blue display element is used. Therefore, the length of d4 is preferably 207 nm or less, and is preferably about 75 nm when the blue display element is used. The second pattern composed of the plurality of graphic elements S needs to be produced in a size that does not interfere with the light scattering effect of the first pattern composed of the plurality of graphic elements R, and visible light is produced. It is preferably smaller than the plurality of graphic elements R to be scattered and has a wavelength in the ultraviolet region.

The depth h3 of the second recess 23 is preferably 200 nm or more and 500 nm or less. When the depth h3 of the second recess 23 is 200 nm or more, it is possible to suppress peeling by increasing the surface area of the side wall of the second recess 23 and improving the adhesion. Further, when the depth h3 of the second recess 23 is 500 nm or less, in addition to being easy to form the second structure, it is possible to control the scattering effect of the reflected light and improve the visibility. The depth h3 of the second recess 23 is preferably deeper than the depth h2 of the first recess 22.

Further, in order to further improve the adhesion, the concavo-convex structure 13 may be subjected to corona treatment or the like before the multilayer film layer 14 is formed to increase the surface area of the concavo-convex structure 13.

When the second structure is viewed from the direction facing the surface, the proportion of the second recess 23 in the region constituting the uneven layer is preferably 10% or more and 30% or less. When the area of the second recess 23 is excessively small, the area where peeling can be reduced is limited to a very small part. On the other hand, if the area of the second recess 23 is excessively large, the scattering effect of the first structure is hindered, and the desired color development as a display body cannot be obtained.

According to the display body according to the present embodiment, the long side direction of the first structure is irregularly divided by the second structure, and the shear stress along the Dy direction of the first structure is released to release the peeling. It is possible to reduce the area. Further, by increasing the depth of the second concave portion constituting the second structure, the surface area can be increased and the adhesion can be improved. As a result, it is possible to obtain a display body in which peeling is suppressed without interfering with the light scattering effect of the first structure.

<Effect of the first embodiment>
The display body 10 according to the present embodiment has the following effects.
(1) The concave-convex structure 13 of the display body 10 of the present embodiment includes a first structure having a plurality of recesses contributing to scattering and a second structure having at least one recess for suppressing peeling.
According to this configuration, the adhesion between the uneven structure 13 and the multilayer film layer 14 is improved.
(2) In the plurality of graphic elements R of the display body 10 of the present embodiment, the standard deviation of the side length d2 along the second direction Dy is the standard deviation of the side length d1 along the first direction Dx. Greater than.
According to this configuration, it is possible to suppress a decrease in the reflectance of the display body 10.
(3) The depth h3 of the second recess 23 of the display body 10 of the present embodiment is larger than the depth h2 of the first recess 22.
According to this configuration, the adhesion of the entire display body 10 can be improved.
(4) In the display body 10 of the present embodiment, the second recess intersects at least a part of the long side constituting the first recess when viewed from the viewpoint facing the surface of the uneven layer.
According to this configuration, the adhesion between the uneven structure 13 and the multilayer film layer 14 is improved.

<Second Embodiment>
FIG. 5 is a cross-sectional view showing a configuration example of a pixel element of a display body manufactured by the manufacturing method according to the present embodiment. This corresponds to FIG. 1 in the first embodiment.
In FIG. 5, the same parts as those described in the first embodiment are designated by the same reference numerals, and the following description avoids duplicate explanations and describes points different from those in the first embodiment.
That is, the display body manufactured by the manufacturing method according to the present embodiment has irregularities on the resin layer 53 formed between the multilayer film layer 14 and the base material 55, as illustrated in FIG. The point that the structure is formed is different from the display body according to the first embodiment.

That is, instead of the base material 55 itself forming the uneven layer, the resin layer 53 provided on the base material 55 constitutes the uneven layer. According to this configuration, the degree of freedom in selecting the material of the base material is increased as compared with the uneven structure 13 in which the uneven structure is formed on the base material.
The resin layer 53 is composed of a photocurable resin applied to the surface of the base material 55, for example, when the concave-convex structure 13 is formed by the optical nanoimprint method.
In the method for manufacturing a display body according to the present embodiment, the upper surface of the resin layer 53 made of the photocurable resin is processed to form the uneven structure 13. In this case, it is necessary to prepare a mold for optical imprinting.

In order to produce the imprint mold, known techniques such as electron beam, ultraviolet lithography and dry etching may be used as described in the first embodiment. Alternatively, in order to more easily produce an imprint mold, a metal such as nickel (Ni) is formed on the formed resist pattern, electroformed, and the resist is melted to form an imprint. A method for producing a printing mold may be applied.
Even with such a manufacturing method, it is possible to manufacture the display body 10 as described in the first embodiment.

<Effect of the second embodiment>
The display body 50 according to the present embodiment has the following effects in addition to the effects of the first embodiment.
(5) In the display body 50 of the present embodiment, an uneven structure is formed on the resin layer 53 formed between the multilayer film layer 14 and the base material 55.
According to this configuration, the degree of freedom in selecting the material of the base material is increased, and the nanoimprint method suitable for the formation of fine unevenness can be applied to the formation of the uneven structure.

Hereinafter, the present disclosure will be described in more detail with reference to Examples, but the present disclosure is not limited to any examples.
<Example 1>

The display body and the manufacturing method thereof in Example 1 will be described. In the display body of this embodiment, a concavo-convex structure layer containing an ultraviolet curable resin and a multilayer film layer in which five layers of TiO ₂ thin films and five layers of SiO ₂ thin films are alternately laminated on a substrate containing polyethylene terephthalate are formed. It has a formed structure. Further, the display element of the display body of the first embodiment is composed of a display element having an uneven structure formed on the base material, as shown in FIG.
First, a plate for forming an uneven structure was prepared by using an optical imprint method. In this embodiment, the plate is formed by using the optical imprint method, but the plate may be formed by using the thermal print method. The unevenness of the object to be formed on the uneven structure layer was formed on the resist film on the synthetic quartz substrate by electron beam drawing and development. In the electron beam drawing step, the first structure having a light scattering effect was drawn first, and then the second structure for suppressing peeling was drawn. Subsequently, a Ni thin film to be a seed layer was deposited on the resist film by a vacuum vapor deposition method at 20 nm. Then, it was immersed in a mixed solution of amide sulfuric acid and boric acid to perform electroforming. Finally, the Ni plate was peeled off by dissolving the resist film on the synthetic quartz to obtain a Ni plate in which the unevenness of the object to be formed was inverted.

Next, a photocurable resin is applied onto a PET film that has been easily adhered to one side, and the surface on which the unevenness of the Ni plate is formed is pressed against this resin to irradiate it with light having a wavelength of 365 nm. The resin was cured. Then, the cured resin and PET film were peeled off from the mold. As a result, a laminate of a resin layer having an uneven structure and a PET film as a base material was obtained.

Subsequently, on the surface of the obtained laminated body of the resin layer and the base material having unevenness, and then on the uneven structure layer, a TiO ₂ thin film having a thickness of 60 nm and a thickness of 80 nm were used by a vacuum vapor deposition method. The SiO ₂ thin films were alternately laminated to form a multilayer film layer. The TiO ₂ thin film is a high refractive index layer, and the SiO ₂ thin film is a low refractive index layer. As a result, the display body of the example was obtained.

The display body of Example 1 was compared with a display body in which only the first structure was prepared and a multilayer film was formed. As a result, the display body of Example 1 had better adhesion, and in particular, peeling along the Dy direction was suppressed. In addition, no deterioration in visibility was observed due to the second structure, and desired color development was obtained.

The display body of the present invention can be used for a display object having a high design. In particular, it is expected to be suitably used for surface decoration on curved surfaces, security fields, and outdoor display and decoration due to the improved adhesion between the uneven structure and the interface of the multilayer film.

10, 50 ... Display 11 ... Low refractive index layer 12 ... High refractive index layer 13 ... Concavo-convex structure (base material)
14 ... Multilayer film layer 20 ... Display element 21 ... Overlapping portion of first recess and second recess 22 ... First recess 23 ... Second recess 30 ... First pattern 40 ... Second pattern 53 ... Resin layer 55 ... Base material Dx ... First direction Dy ... Second direction R, S ... Graphic element

Claims (13)

An uneven layer with an uneven structure and
It has a surface shape that follows the uneven structure, and is provided with a multilayer film layer composed of two or more layers.
In the multilayer film layer, the refractive indexes of adjacent layers are different from each other.
The uneven structure comprises a first structure having a plurality of recesses contributing to scattering and a second structure having at least one recess for suppressing peeling.
Seen from the viewpoint facing the surface of the uneven layer
The pattern formed by the first concave portion constituting the first structure is that the length of the side along the first direction is equal to or less than the sub-wavelength, and the side along the second direction intersecting with the first direction. A pattern consisting of a set of a plurality of graphic elements whose length is equal to or longer than the length of a side along the first direction is included, and the standard deviation of the length of the side along the second direction in the plurality of graphic elements. Is greater than the standard deviation of the length of the sides along the first direction.
The depth of the second recess constituting the second structure is deeper than the depth of the first recess.
A display body characterized in that the second recess intersects at least a part of a long side constituting the first recess when viewed from a viewpoint facing the surface of the uneven layer. Seen from the viewpoint facing the surface of the uneven layer
In the pattern formed by the second recess, the length of the side along the first direction is longer than the length of the side along the first direction of the pattern formed by the first recess, and the first recess is formed. The display body according to claim 1, wherein the display body intersects with a constituent pattern. Claim 1 or 2 characterized in that the length of the side of the second recess along the second direction is 1/4 or less of the length of the side of the first recess along the first direction. Display body described in. The display body according to any one of claims 1 to 3, wherein the depth of the recess of the second structure is 200 nm or more and 500 nm or less. Claim 1 is characterized in that, when the second structure is viewed from a direction facing the surface, the ratio of the second recess to the region constituting the uneven layer is 10% or more and 30% or less. The display body according to any one of 4 to 4. The display body according to any one of claims 1 to 5, wherein the length of the side of the first recess along the first direction is 830 nm or less. Any of claims 1 to 6, wherein the average value of the lengths of the sides of the first recess along the second direction is 4.15 μm or less, and the standard deviation of the length is 1 μm or less. The display body described in item 1. When the first structure is viewed from the direction facing the surface of the uneven layer, the first concave portion occupies 40% or more and 60% or less in the region constituting the uneven layer. The display body according to any one of claims 1 to 7. The display according to any one of claims 1 to 8, wherein in the first structure, display regions having different structural depths of the first recess are included, and the difference is 5 nm or more and 200 nm or less. body. The display body according to any one of claims 1 to 9, wherein in the first structure, the depth of the first recess is constant in each display area. 2. The display body described in any one of them. The uneven structure is formed on one surface side of the base material, and is formed.
The display body according to any one of claims 1 to 11, wherein the base material is formed of a material that absorbs light in the visible light wavelength region. The uneven structure is formed on one surface side of the base material, and the uneven structure is formed.
The display body according to any one of claims 1 to 12, wherein the back surface opposite to one surface of the substrate is formed of a material that absorbs light in the visible light wavelength region.

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