JP6801181B2 - Color-developing structure and its manufacturing method - Google Patents

Description

The present invention relates to a color-developing structure that develops color by a structure formed on the surface and a method for producing the same.

Unlike the color-developing phenomenon that involves electron transition due to light absorption such as dyes, the substance itself does not have light absorption, but it causes diffraction, interference, and scattering by periodic structures that are about the same as or smaller than the wavelength of light. Utilizing this, there is a color development phenomenon in which color is developed by reflecting or transmitting only light of a specific wavelength. Hereinafter, in the present specification, this color development phenomenon will be referred to as structural color development.

For example, when the structure is composed of an inorganic dielectric material that is not deteriorated by ultraviolet rays, it does not fade even if it is left in an environment irradiated with ultraviolet rays as long as the structure is maintained.

Further, structural color development using diffraction and interference has a characteristic that the wavelength of light recognized changes depending on the observation angle, so that it is possible to express with high design.

As a color-developing body by such structural color development, a color-developing structure utilizing multilayer film interference in which polymer materials having different refractive indexes have a multilayer structure has been proposed (Patent Document 1).

However, since the color-developing structure proposed in Patent Document 1 has a multi-layer structure of a polymer material, the difference in refractive index between the materials constituting the adjacent layers is small, and the colored structures are laminated in multiple layers in order to obtain strong reflection. It is necessary and the manufacturing cost is high. Further, the influence of the multilayer film interference becomes dominant, the color change depending on the observation angle becomes steep, and it becomes difficult to express a specific color in a wide observation angle.

Therefore, a display device provided with a color-developing structure having a strong reflection and a color-developing characteristic in which the color change is gradual depending on the observation angle, such as the morpho butterfly inhabiting the natural world, has been proposed (Patent Document 2). ).

Further, a SiO ₂ fine particle layer in which silicon dioxide (SiO ₂ ) fine particles are arranged is formed on a base material, a chromium (Cr) layer is formed on the SiO ₂ fine particle layer for light absorption, and a chromium (Cr) layer is formed on the Cr layer. A light reflecting plate in which titanium dioxide (TiO ₂ ) layers and SiO ₂ layers are alternately laminated has also been reported (Non-Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-246829 JP-A-2007-225935

Journal of the Optical Society of The Optical Society A, Volume 30, No. 5, Page 962

The color-developing structure proposed in Patent Document 2 has a non-uniform uneven structure formed on a base material, and a laminated film is formed on the uneven structure, so that the uneven structure is irregular due to interference by the laminated film. It gives the effect of spreading light and realizes a gradual color change depending on the observation angle.

However, when the base material and the uneven structure are made of a material that transmits light in the wavelength band in the visible region, the light transmitted through the laminated film escapes from the back surface of the color former as it is. Therefore, when observing from the front side in an environment where light is irradiated not only from the front side of the color-developing structure but also from the back side, the light transmitted from the back side is also observed, and the color contrast is lowered. ..

In order to prevent a decrease in color contrast, even if a material that absorbs light in the wavelength band in the visible region is formed on the back surface side of the color former, reflection occurs at the interface with the base material. Further, when the base material or the uneven structure is changed to a material that absorbs light in the wavelength band in the visible region such as carbon, when applying the optical nanoimprint method utilizing the resin effect by ultraviolet irradiation in forming the uneven structure, Since it becomes impossible to irradiate ultraviolet rays from the base material side, it becomes difficult to apply a highly productive optical nanoimprint method to the production of a colored structure.

On the other hand, the light reflector reported in Non-Patent Document 1 imparts irregularity to the width and height of the concavo-convex structure by allowing the particle size of the SiO ₂ fine particles to have a width of 200 to 400 nm. Further, the Cr layer formed on the fine particles absorbs the light transmitted through the laminated film composed of the TiO ₂ layer and the SiO ₂ layer formed on the Cr layer, so that a reflector having high color contrast can be obtained.

However, for forming a Cr on a SiO ₂ fine particles, the surface roughness of the Cr layer surface is smaller than the surface roughness of the SiO ₂ particles. As a structure for preventing the reflection of incident light, an aggregate of protrusion structures imitating the eyes of a moth is generally known. When the antireflection effect is obtained by the aggregate of such protrusion structures, it is said that the higher the structure height of the protrusion structure, the higher the antireflection effect. However, in the reflector reported in Non-Patent Document 1, since the surface roughness of the Cr layer surface is defined by the particle size of the SiO ₂ fine particles, it is difficult to control the antireflection effect by the Cr layer.

Further, since the SiO ₂ fine particles are self-organized, the optical characteristics and the like may vary in the production of the light reflector, and the yield may decrease.

Therefore, it is an object of the present invention to provide a color-developing structure having high color contrast and a method for producing the same.

The color-developing structure according to the present invention transmits a base material, a concavo-convex structure composed of a base material surface or an aggregate of a plurality of convex portions formed on the base material, and light of the same wavelength band on the concavo-convex structure. In addition, it has a laminated body composed of two or more layers made of materials having different refractive indexes with respect to light in the wavelength band, and the uneven structure is made of a material that reflects or absorbs light in the wavelength band. The concave-convex structure is composed of an aggregate of protrusion structures that imitate the eyes of a moth. In the concave-convex structure, the deviation of the structural height of the convex portion is 1/3 or less of the average value of the structural height of the convex portion , and overall height of the protrusions is shall to have a irregular distribution.

Alternatively, the color-developing structure according to the present invention has a concavo-convex structure composed of a base material and an aggregate of a plurality of convex portions formed on the surface of the base material or the base material, and light having the same wavelength band on the concavo-convex structure. It has a laminated body composed of two or more layers made of materials that are transmitted and have different refractive indexes with respect to light in the wavelength band, and the concave-convex structure has a flat portion between adjacent convex portions. It is a concavo-convex structure that exists, and has a layer made of a material that reflects or absorbs light in the wavelength band between the concavo-convex structure and the laminate, and in the concavo-convex structure, the deviation of the structural height of the convex portion is 1/3 or less of the average value of the structural height of the convex portion, and the structure height of the convex portion is shall to have a irregular distribution.

Further, the present invention comprises a base material, a concavo-convex structure formed on the surface of the base material or an aggregate of a plurality of convex portions formed on the base material, and a laminated body composed of two or more layers on the concavo-convex structure. The present invention relates to a method for manufacturing a color-developing structure that selectively reflects light of a part of the wavelengths of the irradiated light of a predetermined wavelength band, and in the concave-convex structure, the deviation of the structural height of the convex portion. However, it is less than 1/3 of the average value of the structural height of the convex portion, and the structural height of the convex portion has an irregular distribution, and a plurality of concave portions are arranged in a grid pattern on the substrate. , A mold for optical nanoimprint having a lattice-like structure in which the uneven structure is inverted, in which a flat portion exists between adjacent recesses, and the center of the recess is deviated from the center position determined by the lattice structure of the lattice structure. The process of preparing a mold for optical nanoimprint, which is distributed and the distance between the center of the recess and the center position determined by the structural cycle of the lattice structure is smaller than the pitch of the lattice structure, and the photocurable resin as the base material. And the step of transferring the structure formed in the mold to the photocurable resin layer by the optical nanoimprint method to form the uneven structure, and the process of forming the uneven structure on the base material on which the uneven structure is formed A process of forming a metal layer that reflects light and materials that transmit light in the wavelength band and have different refractive indexes with respect to the light in the wavelength band are alternately laminated on the metal layer to form a laminated body. It is provided with a step of performing.

The present invention has a base material, a concavo-convex structure composed of an aggregate of a plurality of convex portions formed on the surface of the base material or the base material, and a laminated body composed of two or more layers on the concavo-convex structure. , A method of manufacturing a color-developing structure that selectively reflects light of a part of the irradiated light of a predetermined wavelength band, and in a concave-convex structure, the deviation of the structural height of the convex portion is convex. It is less than 1/3 of the average value of the structural height of the part, and the structural height of the convex part has an irregular distribution, and a plurality of concave parts are arranged in a grid pattern on the substrate, resulting in an uneven structure. It is a mold for thermal nanoimprint having a lattice structure in which the above is inverted, and a flat portion exists between adjacent recesses, and the center of the recess is distributed deviated from the center position determined by the lattice structure of the lattice structure. A process of preparing a mold for thermal nanoimprint in which the distance between the center of the recess and the center position determined by the structural cycle of the lattice structure is smaller than the pitch of the lattice structure, and a thermoplastic resin or thermosetting as the base material. A step of applying a resin, a step of transferring a structure formed in a mold to a thermoplastic resin layer or a thermosetting resin layer by a thermal nanoimprint method to form a concavo-convex structure, and a step of forming a concavo-convex structure on a substrate on which the concavo-convex structure is formed. In addition, a step of forming a metal layer that reflects light in the wavelength band and a material that transmits light in the wavelength band and has a different refractive index to the light in the wavelength band are alternately laminated on the metal layer. It is provided with a step of forming a laminated body.

According to the present invention, since the uneven structure suppresses the reflection of light transmitted through the laminated body of the color-developing structure, it is possible to realize a color-developing structure having high color contrast.

It is sectional drawing of the color-developing structure which concerns on 1st Embodiment of this invention. It is sectional drawing of the color-developing structure which concerns on 2nd Embodiment of this invention. It is sectional drawing of the color-developing structure which concerns on 3rd Embodiment of this invention.

In the present invention, the wavelength band on which the color-developing structure acts is determined by the line width and arrangement pitch of the convex portions (concave portions) constituting the concave-convex structure and the refractive index and film thickness of the laminated body formed on the concave-convex structure. To. In the present invention, the wavelength band targeted by the color-developing structure is not limited, but in the following embodiments, the color-developing structure particularly targeted for light in the visible region will be described with reference to the drawings. In the present embodiment, the visible region refers to light in the wavelength band of 360 nm to 830 nm.

(First Embodiment)
FIG. 1 is a schematic cross-sectional view of the structural color former according to the first embodiment. Materials that reflect light in the wavelength band of the visible region, such as silicon (Si), aluminum (Al), tantalum (Ta), Cr, etc., or materials that absorb light in the wavelength band of the visible region, such as carbon (C), etc. A protrusion structure (moss eye structure) 21 imitating a moth's eye as shown in FIG. 1A is formed on a base material 11 composed of the above by applying known techniques such as lithography and dry etching. .. Due to the protrusion structure 21, the change in the refractive index at the interface between the material constituting the base material 11 and the material adjacent on the protrusion structure 21 becomes gentle, and the reflection of the visible region at the interface on the surface of the protrusion structure can be suppressed.

It is preferable that the plurality of convex portions constituting the protrusion structure 21 are arranged in a grid pattern. When arranged in a grid pattern, a hexagonal close-packed grid pattern is more preferable, but a square grid pattern may also be used. The pitch of the lattice structure (arrangement pitch of adjacent convex portions) is preferably smaller than the wavelength band of the visible region, that is, 360 nm or less so that the light in the visible region is not first diffracted due to the periodicity of the lattice structure. Further, it is preferable that the center of the convex portion constituting the protrusion structure 21 is irregularly distributed deviating from the center position (design position) on the periodic structure of the lattice structure, and the deviation of the distribution is larger than the pitch of the lattice structure. A small value is preferable, and a value of 1/5 or less of the pitch of the lattice structure is more preferable.

The value of the structural height of the plurality of convex portions constituting the protrusion structure 21 is appropriately designed according to the reflection suppression effect and the reflection optical characteristics of the surface of the structural color former. The structural height of the convex portion may be constant, but it is preferable that the convex portion has an irregular distribution in order to impart a scattering effect. However, if the scattering effect is promoted, the monochromaticity of the light reflected from the surface of the structural color former may be impaired, so that the deviation of the structural height is 1/3 or less of the average value of the structural height. Is more preferable. The protrusion structure 21 having a distribution in the structural height can be formed collectively by, for example, designing the etching mask line width to have a distribution and performing dry etching until the mask completely disappears. In that case, the deviation of the distribution of the mask line width is preferably 1/3 or less of the average value of the mask line width. Further, it is more preferable that the protrusion structure 21 does not have a flat portion on the bottom surface, but a flat portion may be present. The deviation of the bottom area of the convex portion is more preferably 1/3 or less of the design value. The reason is the same as for the structural height. When the convex parts are arranged in a lattice pattern, the design value can be calculated from the periodicity of the lattice structure. The bottom area referred to here is the area of the area surrounded by the virtual line partitioned by the side surface or the bottom surface of the other convex portion adjacent to the side surface of the convex portion, as viewed vertically from above the structural color former. Is. The upper direction corresponds to the direction perpendicular to the lower part of the structural color-developing body in FIG. Even if the convex portion is tilted with respect to the bottom surface of the structural color-developing body, the bottom area is calculated by the value viewed from the direction perpendicular to the bottom surface.

Next, as shown in FIG. 1 (b), a known material having a refractive index different from that of light in the wavelength band in the visible region is applied to the surface of the protrusion structure 21 by a sputtering method, a vapor deposition method, self-assembly, or the like. The technique of the above is applied and laminated to form a laminated film 31. In FIG. 1B, three pairs of two types of layers, a high refractive index layer 41 and a low refractive index layer 51, are sequentially formed on the surface of the protrusion structure 21, and the number of these layers, the material type, and the number thereof are formed. , Film thickness, and stacking order are appropriately designed according to the required optical characteristics. As a material constituting the laminated film, for example, by applying a material having a large refractive index difference such as titanium dioxide (TiO ₂ ) as a high refractive index material and SiO ₂ as a low refractive index material, high reflection is achieved even with a small number of layers. Although the rate can be obtained, reflection occurs at the interface even if the refractive index is slightly different. Therefore, for example, a polymer material can be applied by appropriately designing the number of layers.

When the structural color-developing body obtained as described above is irradiated with white light from the surface side of the base material 11, the light interfered by the laminated body 31 is extracted as reflected light from the surface of the structural color-developing body. On the other hand, light in other wavelength bands is transmitted through the laminated body 31, but is hardly extracted from the surface of the structural color-developing body because the projection structure 21 suppresses the reflection at the interface. As a result, only the light interfered by the laminated body 31 is observed with high contrast. Further, the laminated body 31 is formed on the surface of the protrusion structure 21. In the process of forming each layer, a film is formed while following the surface shape of the adjacent lower layer. Therefore, the laminated body 31 has irregularities in the height direction, and further, by arranging the protrusion structures 21 in a grid pattern, a diffraction effect can be imparted. Therefore, in the structural color-developing body, since the light spreading effect is given to the interference by the laminated body 31, it is possible to realize a gradual color change depending on the observation angle.

(Second Embodiment)
FIG. 2 is a schematic cross-sectional view of the structural color former according to the second embodiment. First, as shown in FIG. 2A, a concavo-convex structure 61 in which a flat portion exists between convex portions adjacent to the surface of the base material 12 is formed. As the material constituting the base material 12, a material that can be processed by applying a known technique such as lithography or dry etching such as Si, SiO ₂ , Cr, and Ta is preferable.

The shape of the convex portion of the concave-convex structure 61 is more preferably a needle shape having no flat portion on the upper surface, but as shown in FIG. 2A, a shape having a flat portion on the upper surface may be used, and the side wall angle may be set. It may be vertical. The concave-convex structure 61 is preferably arranged in a grid pattern. When arranged in a grid pattern, a hexagonal close-packed grid pattern is more preferable, but a square grid pattern may also be used. The pitch of the lattice structure is preferably smaller than the wavelength band of the visible region, that is, 360 nm or less so that the light in the visible region is not first diffracted due to the periodicity of the lattice structure. Further, it is preferable that the center of the convex portion has an irregular distribution with respect to the center of the lattice structure, the deviation of the distribution is preferably a value smaller than the pitch of the lattice structure, and 1/1 of the pitch of the lattice structure. A value of 5 or less is more preferable.

The structural height of the convex portion of the concave-convex structure 61 may be constant, but may have an irregular distribution in order to impart a scattering effect. However, if the scattering effect is promoted, the monochromaticity of the light reflected from the surface of the structural color former may be impaired, so the deviation of the structural height should be 1/3 or less of the average value of the structural height. Is preferable. The protrusion structure 21 having a distribution in the structural height can be formed collectively by, for example, designing the etching mask line width to have a distribution and performing dry etching until the mask completely disappears. In that case, the deviation of the distribution of the mask line width is preferably 1/3 or less of the average value of the mask line width.

Next, as shown in FIG. 2B, a material that reflects light in the wavelength band in the visible region or light in the wavelength band in the visible region is absorbed on the base material 12 on which the concave-film structure 61 is formed on the surface. A material to be formed is formed into a film by applying a known technique such as a sputtering method or a thin film deposition method to form a curved layer 71, and a protrusion structure 22 imitating a moth's eye is obtained. The film thickness of the curved layer 71 is preferably such that the light transmittance in the wavelength band in the visible region is 20% or less when the film is formed on a flat surface. The curved layer 71 is more preferably formed with a film thickness such that the flat portion between the convex portions disappears, but since the reflection suppressing effect can be obtained even if the flat portion between the convex portions is present, the flat portion between the convex portions is formed. It may be formed thinner than the film thickness to the extent that the flat portion disappears.

Next, as shown in FIG. 2C, a material having a refractive index different from that of light in the wavelength band in the visible region is applied to the surface of the protrusion structure 22 on the surface by a sputtering method, a vapor deposition method, self-assembly, or the like. A laminated film 32 is formed by laminating by applying a known technique. In FIG. 2C, three pairs of two types of layers, a high refractive index layer 42 and a low refractive index layer 52, are sequentially formed on the surface of the protrusion structure 22, and the number of these layers, the material type, and the number thereof are shown. The film thickness and the stacking order are appropriately designed according to the required optical characteristics. As the material constituting the laminated film, for example, by applying a material having a large refractive index difference such as TiO _{2 as} a high refractive index material and SiO ₂ as a low refractive index material, high reflectance can be obtained even with a small number of layers. However, since reflection occurs at the interface even if the refractive index is slightly different, it is possible to apply, for example, a polymer material by appropriately designing the number of layers.

When the structural color-developing body obtained as described above is irradiated with white light from the surface side of the base material 12, the light interfered by the laminated body 32 is taken out as reflected light from the surface of the structural color-developing body. On the other hand, light in other wavelength bands is transmitted through the laminated body 32, but is hardly extracted from the surface of the structural color-developing body because the projection structure 22 suppresses the reflection at the interface. As a result, only the light interfered by the laminated body 32 is observed with high contrast. Further, the laminated body 32 is formed on the surface of the protrusion structure 22. In the process of forming each layer, a film is formed while following the surface shape of the adjacent lower layer. Therefore, the laminated body 32 has irregularities in the height direction, and further, by arranging the protrusion structures 22 in a grid pattern, a diffraction effect can be imparted. Therefore, in the structural color-developing body, since the light spreading effect is given to the interference by the laminated body 32, a gradual color change depending on the observation angle can be realized.

(Third Embodiment)
FIG. 3 is a schematic cross-sectional view of the structural color former according to the third embodiment. In the third embodiment, the base material and the uneven structure, or a part forming the uneven structure, are made of different materials. First, as shown in FIG. 3A, a structural layer 81 is formed on the surface of the base material 13 in which a concave-convex structure 62 having a flat portion between adjacent convex portions is formed. In FIG. 3A, the flat surface between the convex portions of the concave-convex structure 62 exists above the surface of the base material 13, but the flat surface between the convex portions of the concave-convex structure 62 is the same surface as the surface of the base material 13. Alternatively, it may be present below the surface of the base material 13. The uneven structure 62 conforms to the uneven structure 61 described in the second embodiment.

As a method for forming the concave-convex structure 62 on the structural layer 81, the application of the optical nanoimprint method or the thermal nanoimprint method is particularly preferable. In this case, the material constituting the structural layer 81 is a photocurable resin when the optical nanoimprint method is applied, a thermoplastic resin or a thermosetting resin when the thermal nanoimprint method is applied. The material constituting the base material 13 may be a photocurable resin, a thermoplastic resin, or a material having high adhesion to the thermosetting resin. For example, a polyethylene terephthalate film subjected to an easy-adhesion treatment. Etc. are applicable.

For the optical nanoimprint mold or the thermal nanoimprint mold, for example, a master mold obtained by processing a concave-convex reversal structure of the concave-convex structure 62 by using a known technique such as lithography or dry etching on a SiO ₂ or Si substrate is applied, or a master mold is applied. It is possible to manufacture and apply a replica mold by processing the same structure as the concave-convex structure 62. Further, anodization may be applied to the production of the master mold.

If it is necessary to trim the shape of the obtained uneven structure by applying the optical nanoimprint method or the thermal nanoimprint method, for example, the structure height and line width, plasma treatment is performed after the optical nanoimprint or the thermal nanoimprint. You may do it.

Next, as shown in FIG. 2B, a material that reflects light in the wavelength band of the visible region or a material that absorbs light in the wavelength band of the visual region is subjected to a sputtering method or a vapor deposition method on the structural layer 81. A film is formed by applying a known technique such as, to form a curved layer 72, and a protrusion structure 23 imitating a moth's eye is obtained. The film thickness of the curved layer 71 is preferably such that the light transmittance in the wavelength band in the visible region is 20% or less when the film is formed on a flat surface. The curved layer 72 is more preferably formed with a film thickness such that the flat portions between the convex portions disappear, but since the reflection suppressing effect can be obtained even if the flat portions between the convex portions are present, the reflection suppressing effect can be obtained. It may be formed thinner than the film thickness to the extent that the flat portion disappears.

Next, as shown in FIG. 2C, a material having a refractive index different from that of light in the wavelength band in the visible region is applied to the surface of the protrusion structure 23 on the surface by a sputtering method, a vapor deposition method, self-assembly, or the like. A laminated film 33 is formed by laminating by applying a known technique. In FIG. 2C, two types of layers, a high refractive index layer 43 and a low refractive index layer 53, are sequentially formed on the surface of the protrusion structure 23, and the number of these layers, the material type, and the number thereof are formed. , Film thickness, and stacking order are appropriately designed according to the required optical characteristics. As the material constituting the laminated film, for example, by applying a material having a large refractive index difference such as TiO _{2 as} a high refractive index material and SiO ₂ as a low refractive index material, high reflectance can be obtained even with a small number of layers. However, since reflection occurs at the interface even if the refractive index is slightly different, it is possible to apply, for example, a polymer material by appropriately designing the number of layers.

When the structural color-developing body obtained as described above is irradiated with white light from the surface side of the base material 13, the light interfered by the laminated body 33 is extracted as reflected light from the surface of the structural color-developing body. On the other hand, light in other wavelength bands passes through the laminated body 33, but is hardly extracted from the surface of the structural color-developing body because the projection structure 23 suppresses the reflection at the interface. As a result, only the light interfered by the laminated body 33 is observed with high contrast. Further, the laminated body 33 is formed on the surface of the protrusion structure 23. In the process of forming each layer, a film is formed while following the surface shape of the adjacent lower layer. Therefore, the laminated body 33 has irregularities in the height direction, and further, by arranging the protrusion structures 23 in a grid pattern, a diffraction effect can be imparted. Therefore, in the structural color-developing body, since the light spreading effect is given to the interference by the laminated body 33, a gradual color change depending on the observation angle can be realized.

It should be noted that, as in the first to third embodiments described above, the color-developing structure is manufactured by designing the convex portion so that at least one of the center position, the structural height, and the bottom area is irregular. Even when variations (manufacturing errors) occur between batches at the time, variations in optical characteristics can be suppressed and yield can be improved.

First, a mold for optical nanoimprint was prepared. Specifically, since the wavelength of the light irradiated in the optical nanoimprint was 365 nm, synthetic quartz that transmits light of this wavelength was used as the molding material. Cr was formed on the surface of the synthetic quartz substrate by sputtering, and an electron beam resist pattern was formed on the electron beam resist coated on the Cr film by electron beam lithography. The electron beam resist used was a positive type, and the film thickness was 150 nm. In the XY coordinate system, the pattern drawn by the electron beam has a square with a side of 150 nm in a square area with a side of 3 cm, and the center coordinate of a square lattice array with a period of 300 nm for both the X and Y coordinates as the center value, and the standard deviation is 15 nm. It is a pattern arranged at the coordinates selected from the normal distribution of, and the area where the electron beam is drawn is the inner area of the square. Cr in the exposed surface region was etched and removed by plasma generated by applying a high frequency to a mixed gas of chlorine and oxygen. Subsequently, the quartz in the region where the surface was exposed was etched by the plasma generated by applying a high frequency to the hexafluorinated ethane gas. The quartz depth etched by this step was 150 nm. The remaining resist and Cr film were removed, and Optool HD-1100 (manufactured by Daikin Industries, Ltd.) was applied as a release agent to obtain a mold for optical nanoimprint.

Next, a photocurable resin of 100 nm was applied onto the synthetic quartz wafer, and the synthetic quartz wafer was irradiated with 10 J / m ² of light at 365 nm while pressing the optical nanon print mold against the synthetic quartz wafer at a pressure of 50 kN. Subsequently, the mold for optical nanon printing was released from the synthetic quartz wafer to obtain a synthetic quartz substrate on which a photocurable resin pattern was formed.

Next, the synthetic quartz substrate on which the photocurable resin pattern was formed was exposed to plasma generated by applying a high frequency to oxygen gas, and the residual film generated in the optical nanoimprinting step was removed. Subsequently, the quartz in the region where the surface was exposed was etched by the plasma generated by applying a high frequency to the hexafluorinated ethane gas. The quartz depth etched by this step was 120 nm. The removal of the remaining resist synthetic quartz substrate surface, an Al film having a thickness of 300nm by evaporation, at followed by SiO ₂ having a thickness of 55nm of TiO ₂ and a thickness of 76nm alternately 5 to evaporation A film was formed to obtain a structural color developer.

When the reflected spectroscopic measurement was performed on the obtained structural color-developing body from the vertical direction, a spectroscopic spectrum having a peak intensity of about 60% at the maximum at about 460 nm was obtained in the region where the structure was formed. Although there are sharp wells at about 500 nm in the structure-unformed region, a spectroscopic spectrum showing a reflectance of 80% or more was obtained in other wavelength regions. It should be noted that, under white light irradiation, the color of the structure-forming region hardly changes when the obtained structural color-developing body is observed at an angle in the ± 50 ° region.

The color-developing structure of the present invention can be used for a display object having a high degree of design. In particular, it is expected to be suitably used in the field of surface decoration.

11, 12, 13 ... Base materials 21, 22, 23 ... Projection structures 31, 32, 33 ... Laminates 41, 42, 43 ... High refractive index layers 51, 52, 53 ... Low refractive index layers 61, 62 ... Concavo-convex structure 71, 72 ... Curved layer 81 ... Structural layer

Claims (8)

A base material, a concavo-convex structure composed of an aggregate of a plurality of convex portions formed on the surface of the base material or the base material, and a light of the same wavelength band transmitted on the concavo-convex structure, and the wavelength band In a color-developing structure having a laminated body composed of two or more layers made of materials having different refractive indexes with respect to the light of
The uneven structure is composed of a material that reflects or absorbs light in the wavelength band.
The uneven structure is composed of an aggregate of protrusion structures that imitate the eyes of a moth.
In the uneven structure, the deviation of the structural height of the convex portion is 1/3 or less of the average value of the structural height of the convex portion, and the structural height of the convex portion has an irregular distribution. A color-developing structure characterized by. A base material, a concavo-convex structure composed of an aggregate of a plurality of convex portions formed on the surface of the base material or the base material, and a light of the same wavelength band transmitted on the concavo-convex structure, and the wavelength band In a color-developing structure having a laminated body composed of two or more layers made of materials having different refractive indexes with respect to the light of
The uneven structure is a concave-convex structure in which a flat portion exists between the adjacent convex portions.
A layer made of a material that reflects or absorbs light in the wavelength band is provided between the uneven structure and the laminated body.
In the uneven structure, the deviation of the structural height of the convex portion is 1/3 or less of the average value of the structural height of the convex portion, and the structural height of the convex portion has an irregular distribution. A color-developing structure characterized by. The first or second aspect of the present invention, wherein the uneven structure formed on the surface of the base material or the base material is a grid-like structure in which a plurality of the convex portions are arranged in a grid pattern. Coloring structure. The center of the convex portion of the concavo-convex structure is distributed deviating from the center position determined by the structural period of the lattice-like structure, and the center of the convex portion of the concavo-convex structure and the structural period of the lattice-like structure The color-developing structure according to claim 3, wherein the distance from the determined center position is smaller than the pitch of the grid-like structure. 4. The distance between the center of the convex portion of the concave-convex structure and the center position determined by the structural period of the lattice-like structure is 1/5 or less of the pitch of the lattice-like structure. The colored structure described. The color-developing structure according to any one of claims 3 to 5, wherein the pitch of the lattice-like structure is smaller than the wavelength band of light transmitted through the material constituting the laminate. It has a base material, a concavo-convex structure formed on the surface of the base material or an aggregate of a plurality of convex portions formed on the base material, and a laminated body composed of two or more layers on the concavo-convex structure. A method for producing a color-developing structure that selectively reflects light of a part of the irradiated light of a predetermined wavelength band.
In the uneven structure, the deviation of the structural height of the convex portion is 1/3 or less of the average value of the structural height of the convex portion, and the structural height of the convex portion has an irregular distribution. ,
An optical nanoimprint mold having a grid-like structure in which a plurality of recesses are arranged in a grid pattern on a substrate, and the concave-convex structure is inverted. A flat portion exists between the adjacent recesses, and the recesses Is distributed deviating from the center position determined by the structural cycle of the lattice structure, and the distance between the center of the recess and the center position determined by the structural cycle of the lattice structure is the lattice structure. The process of preparing a mold for optical nanoimprint that is smaller than the pitch of
The step of applying a photocurable resin to the base material and
A step of transferring the structure formed in the mold to the photocurable resin layer by the optical nanoimprint method to form the uneven structure.
A step of forming a metal layer that reflects light in the wavelength band on a base material on which the uneven structure is formed, and
The metal layer is provided with a step of alternately laminating materials that transmit light in the wavelength band and have different refractive indexes with respect to the light in the wavelength band to form the laminated body. A method for manufacturing a colored structure, which comprises. It has a base material, a concavo-convex structure formed on the surface of the base material or an aggregate of a plurality of convex portions formed on the base material, and a laminated body composed of two or more layers on the concavo-convex structure. A method for producing a color-developing structure that selectively reflects light of a part of the irradiated light of a predetermined wavelength band.
In the uneven structure, the deviation of the structural height of the convex portion is 1/3 or less of the average value of the structural height of the convex portion, and the structural height of the convex portion has an irregular distribution. ,
A mold for thermal nanoimprint having a grid-like structure in which a plurality of recesses are arranged in a grid pattern on a substrate, and the concave-convex structure is inverted. A flat portion exists between the adjacent recesses, and the recesses Is distributed deviating from the center position determined by the structural cycle of the lattice structure, and the distance between the center of the recess and the center position determined by the structural cycle of the lattice structure is the lattice structure. The process of preparing a mold for thermal nanoimprint that is smaller than the pitch of
The step of applying a thermoplastic resin or a thermosetting resin to the base material, and
A step of transferring the structure formed in the mold to the thermoplastic resin layer or the thermosetting resin layer by the thermal nanoimprint method to form the uneven structure.
A step of forming a metal layer that reflects light in the wavelength band on a base material on which the uneven structure is formed, and
The metal layer is provided with a step of alternately laminating materials that transmit light in the wavelength band and have different refractive indexes with respect to the light in the wavelength band to form the laminated body. A method for manufacturing a colored structure, which comprises.