JP2022075250A - Color developing sheet, color development article, transfer foil and manufacturing method of transfer foil - Google Patents

Abstract

To provide a color developing sheet capable of preventing a multilayer film layer from being damaged by a tension.SOLUTION: A color developing sheet includes a support medium 11 and a multilayer film layer 13 formed on the support medium 11. The multilayer film layer 13 is configured such that layers 13a, 13b neighboring to each other in the multilayer film layer 13 have refractive indexes different from each other and that a light reflectance ratio at a specific wavelength region in incident light to the multilayer film layer 13 is higher than a light reflectance ratio at another wavelength region. Furthermore, the support medium 11 at least includes a pressure resistance layer 11a and a cushion layer 11b, being two layers having hardness different from each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to a color-developing sheet, a color-developing article, a transfer foil, and a method for producing a transfer foil.

The structural color often observed as the color of natural organisms such as morpho butterflies is the color 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 generated when light is reflected at the interface between thin films adjacent to each other and the reflected light interferes with each other. Multilayer film interference is one of the color-developing principles of the wing of a Morpho butterfly. In the wing of the morpho butterfly, in addition to the multi-layer film interference, light scattering and diffraction occur due to the fine irregularities on the surface of the wing, and as a result, a bright blue color is visually recognized at a wide observation angle.

As a color-developing sheet that artificially reproduces a structural color such as the wing of a morpho butterfly, as described in Patent Document 1, a color-developing sheet in which a multilayer film layer is laminated on a layer having fine irregularities arranged unevenly. Has been proposed. In a color-developing sheet in which a multilayer film layer is laminated on a flat surface, the wavelength of the reflected light that is visually recognized changes greatly depending on the observation angle, so that the color that is visually recognized on the color-developing sheet changes greatly depending on the observation angle. On the other hand, in the color-developing sheet described in Patent Document 1, the reflected light enhanced by the interference spreads in multiple directions due to the irregular unevenness, so that the color change depending on the observation angle becomes gentle. As a result, a specific color is observed at a wide observation angle like the wing of a morpho butterfly.

Japanese Unexamined Patent Publication No. 2018-11732

By the way, an inorganic compound is used for the multilayer film layer of the color-developing sheet described in Patent Document 1. Inorganic compounds are generally brittle and are prone to problems such as cracking and chipping due to external stimuli. Therefore, in the transfer foil formed by forming an adhesive layer on the color-developing sheet described in Patent Document 1, for example, after the transfer foil is attached to the adherend, the transfer foil is adhered to the transfer foil for reattachment. When the user pulls the transfer foil so that it peels off from the body and tensile stress is applied to the transfer foil and the multilayer film layer is deformed, the multilayer film layer is cracked or chipped, and the color-developing sheet has a poor appearance. there's a possibility that.

An object of the present invention is to provide a color-developing sheet, a color-developing article, a transfer foil, and a method for producing a transfer foil, which can prevent the multilayer film layer from being damaged by pulling.

In order to solve the above problems, the color-developing sheet according to one aspect of the present invention includes (a) a support and a multilayer film layer formed on the support, and (b) the multilayer film layer is a multilayer film. The refractive elements of adjacent layers in the layer are different from each other, and the reflectance of light in a specific wavelength range of the incident light to the multilayer film layer is higher than that of light in other wavelength ranges. , (C) The surface of the multilayer film layer on the support side has a first uneven structure having a plurality of recesses, and (d) a pattern formed by the recesses when viewed from the direction along the thickness direction of the multilayer film layer. Is from a set of a plurality of graphic elements whose length along the first direction is less than or equal to the sub-wavelength and whose length along the second direction orthogonal to the first direction is greater than or equal to the length along the first direction. (E) In a plurality of graphic elements, the standard deviation of the length along the second direction is larger than the standard deviation of the length along the first direction, and (f) the support is hard. The gist is that they contain at least two layers that are different from each other.

Further, it is a gist that the color-developing article according to one aspect of the present invention includes the above-mentioned color-developing sheet and an adherend to which the color-developing sheet is attached.

Further, the transfer foil according to one aspect of the present invention is formed on (a) a support, a concavo-convex structure layer formed on the support and having a concavo-convex structure on the surface opposite to the support, and a concavo-convex structure layer. A multilayer film layer having a surface shape that follows the uneven structure, an anchor layer formed on the multilayer film layer, a light absorption layer formed on the anchor layer, and an adhesive layer formed on the light absorption layer. (B) The multilayer film layer has different refractive coefficients of adjacent layers in the multilayer film layer, and the reflectance of light in a specific wavelength range of the incident light to the multilayer film layer is different. The convex portion constituting the concave-convex structure is configured to have a higher reflectance than the light reflectance in the wavelength range of (c), and the pattern formed by the convex portion is along the first direction when viewed from the multilayer film layer side. A plurality of patterns including a set of a plurality of graphic elements having a length equal to or less than a sub-wavelength and a length along a second direction orthogonal to the first direction equal to or greater than a length along the first direction. In the graphic element of, the standard deviation of the length along the second direction is larger than the standard deviation of the length along the first direction, and (d) the support contains at least two layers having different hardnesses. Is the gist.

Further, the method for producing a transfer foil according to one aspect of the present invention includes (a) a step of forming a resin layer having a concavo-convex structure on one surface of a support, and (b) a multilayer film along the concavo-convex structure. Layers that are adjacent to each other in the multilayer film layer have different refractive coefficients, and the reflectance of light in a specific wavelength range of the incident light to the multilayer film layer is the reflectance of light in other wavelength ranges. The step of forming the anchor layer so as to be higher than the above, (c) the step of forming the anchor layer on the surface of the multilayer film layer opposite to the surface of the resin layer side, and (d) the step of forming the anchor layer on the opposite side of the multilayer film layer. The step of forming the light absorbing layer on the surface and the step of forming the adhesive layer on the surface opposite to the anchor layer of the light absorbing layer are included, and in the step of forming the resin layer, the resin layer is formed. When viewed from the position facing the surface, the pattern formed by one or more convex portions constituting the concave-convex structure has a length along the first direction of the sub-wavelength or less and is orthogonal to the first direction. A pattern consisting of a set of a plurality of graphic elements whose length along the first direction is equal to or greater than the length along the first direction is included, and in a plurality of graphic elements, the standard deviation of the length along the second direction is the first. The gist is that the uneven structure is formed so as to be larger than the standard deviation of the length along one direction, and (g) the support includes at least two layers having different hardnesses.

According to one aspect of the present invention, it is possible to provide a color-developing sheet, a color-developing article, a transfer foil, and a method for producing a transfer foil, which can prevent the multilayer film layer from being damaged by pulling.

It is a figure which shows the cross-sectional structure of the transfer foil which concerns on 1st Embodiment. It is a figure which shows the cross-sectional structure of the transfer foil which concerns on a modification. It is a figure which shows the transfer foil, (a) is the figure which shows the planar structure of the 2nd uneven structure of a resin layer, and (b) is the figure which shows the cross-sectional structure of the 2nd uneven structure of a resin layer. It is a figure which shows the transfer method of the color-developing sheet, (a) is a figure which shows the adherend which attached the transfer foil, and (b) is the figure which shows the adherend which the color-developing sheet was transferred. It is a figure which shows the cross-sectional structure of the color-developing sheet after transfer. It is a figure which shows the transfer foil which concerns on 2nd Embodiment, (a) is the figure which shows the plane structure of only the 2nd convex part element of the 2nd uneven structure, (b) is the cross-sectional structure of the 2nd uneven structure. It is a figure which shows. It is a figure which shows the transfer foil, (a) is the figure which shows the planar structure of the 2nd uneven structure of a resin layer, and (b) is the figure which shows the cross-sectional structure of the 2nd uneven structure of a resin layer.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments shown below. In the embodiments shown below, technically preferable limitations are made for carrying out the present invention, but these limitations are not essential requirements of the present invention.

1. 1. First Embodiment 1-1. Overall structure 1-2. Structure of the second uneven structure 1-3. Manufacturing method of transfer foil 1-4. Transfer method of color development sheet 1-5. Effect of the first embodiment 2. 2nd Embodiment 2-1. Structure of the second uneven structure 2-2. Configuration of the second convex element 2-3. Structure of the second uneven structure 2-4. Effect of the second embodiment 3. Examples / Comparative Examples 3-1. Example 3-2. Comparative example 3-3. evaluation

<1. First Embodiment>
[1-1. Overall structure]
FIG. 1 is a cross-sectional view showing the structure of the transfer foil 20 according to the present embodiment.
As shown in FIG. 1, the transfer foil 20 is formed by laminating a light absorption layer 15 and an adhesive layer 16 on a color-developing sheet 10 in this order. As a result, the transfer foil 20 can attach the color-developing sheet 10 to the adherend via the adhesive layer 16 (transfer is possible).
The color-developing sheet 10 is formed by laminating a resin layer 12 (an example of an uneven structure layer), a multilayer film layer 13, and an anchor layer 14 on a support 11 in this order. The light absorption layer 15 and the adhesive layer 16 are laminated on the surface on the anchor layer 14 side of the two surfaces of the color-developing sheet 10.

The support 11 includes at least two layers (pressure resistant layer 11a and cushion layer 11b) having different hardnesses. FIG. 1 illustrates a case where the support 11 is composed of only the pressure resistant layer 11a and the cushion layer 11b. Further, although FIG. 1 illustrates a case where the pressure-resistant layer 11a and the cushion layer 11b are not adhered to each other, the structure may be such that the pressure-resistant layer 11a and the cushion layer 11b are adhered to each other via an adhesive layer or the like.
The pressure-resistant layer 11a is a layer arranged on the resin layer 12 side of the two layers constituting the support 11, and is the layer having the higher hardness. As a result, the pressure-resistant layer 11a can suppress the deformation of the resin layer 12 when forming the second uneven structure 12c (described later) of the resin layer 12, and the second uneven structure 12c patterning corresponds to the shape of the plate (mold). can. The hardness of the pressure-resistant layer 11a is preferably 20 or more in type D of JIS K7215 standard. As the measured value of hardness, for example, an average value measured at five points at substantially equal intervals in the film width direction of the pressure resistant layer 11a can be adopted. The hardness measurement environment is preferably an environment having a temperature of 25 ° C. and a humidity of 50%. Further, the melting point of the pressure resistant layer 11a is preferably 90 ° C. or higher. With such a pressure-resistant layer 11a, abnormal deformation of the resin layer 12 due to plate pressure during transfer can be suppressed. That is, it has the pressure resistance required for transfer. For example, if the pressure-resistant layer 11a is less than 20 in JIS K7215 standard type D, the resin layer 12 may not be able to withstand the printing pressure at the time of transfer of the transfer foil 20, and the resin layer 12 may be abnormally deformed. As the material of the pressure resistant layer 11a, for example, a resin such as a synthetic quartz substrate, polyethylene terephthalate (PET), polyester, vinyl chloride, polypropylene, or polyethylene can be adopted. With such a resin, the flexibility of the transfer foil 20 can be improved. The film thickness of the pressure-resistant layer 11a is preferably 10 μm or more and 100 μm or less from the viewpoint of pressure resistance and workability.

The cushion layer 11b is a layer arranged on the side farther from the pressure-resistant layer 11a among the two layers constituting the support 11, and is the layer having the lower hardness. As a result, the hardness of the cushion layer 11b can be reduced as a whole of the support 11. Therefore, for example, after the transfer foil 20 is attached to the adherend, the user pulls the transfer foil 20 so that the transfer foil 20 is peeled off from the adherend in order to reattach the transfer foil 20. When a tensile stress is applied to 20 and the multilayer film layer 13 is deformed, the support 11 can be deformed according to the deformation. Therefore, for example, as compared with the method of forming the support 11 only with a high hardness layer such as the pressure resistant layer 11a, the deformation of the support 11 can be followed by the deformation of the multilayer film layer 13, and the multilayer film layer 13 and the support 11 can be followed. It is possible to reduce that the multilayer film layer 13 receives an external force due to the difference in the amount of deformation with and, and it is possible to suppress damage to the multilayer film layer 13. That is, it has the tensile resistance required by reattachment. Further, it is possible to suppress damage to the multilayer film layer 13 due to an external stimulus applied to the multilayer film layer 13 when the transfer foil 20 is attached. The hardness of the cushion layer 11b is preferably 95 or less in Type A of JIS K6253-3 standard. For example, if the type A of JIS K6253-3 standard is less than 95, the multilayer film layer 13 may be damaged by an external stimulus applied to the multilayer film layer 13 when the transfer foil 20 is attached.
As the material of the cushion layer 11b, for example, a resin such as polyurethane, polystyrene, polyolefin, or polyamide can be adopted. It is preferable that the thickness of the cushion layer 11b is thicker than that of the pressure resistant layer 11a because it is easy to protect the multilayer film layer 13. For example, from the viewpoint of protecting the multilayer film layer 13 from external stimuli and from the viewpoint of processability, it is preferably 50 μm or more and 300 μm or less.

Further, the cushion layer 11b has a peelability with respect to the resin layer 12. As a result, the support 11 can be peeled off from the resin layer 12. The peelability of the cushion layer 11b is realized, for example, by selecting the material of the cushion layer 11b and the material of the resin layer 12 so that the adhesion between the cushion layer 11b and the resin layer 12 is lowered. For example, at least one of the cushion layer 11b and the resin layer 12 contains a silicone oil or a fluorine compound.
Further, the peelability of the cushion layer 11b may be promoted by a physical external stimulus such as heating or cooling. For example, when the resin layer 12 is made of a thermoplastic resin, the resin layer 12 is softened by heating, so that the support 11 is peeled off from the resin layer 12. Further, the peelability of the cushion layer 11b may be realized by a physical external stimulus such as heating or cooling.
Further, the peelability of the cushion layer 11b may be realized by arranging a release layer containing a release agent between the support 11 and the resin layer 12. As the mold release agent, for example, silicone oil or a fluorine compound can be adopted. When the release layer is arranged, an uneven structure may be formed at the interface between the cushion layer 11b (support 11) and the release layer. By forming such an uneven structure, peeling between the cushion layer 11b (support 11) and the release layer can be suppressed.

Although the support 11 is formed only of the pressure resistant layer 11a and the cushion layer 11b in the first embodiment, other configurations may be adopted. For example, an intermediate layer may be arranged between the pressure resistant layer 11a and the cushion layer 11b. As the intermediate layer, for example, an adhesive layer containing an acrylic adhesive, a urethane adhesive, a silicone adhesive or the like, or a stress relaxation layer containing wax, oil or the like can be adopted.

The resin layer 12 is a layer made of a resin that transmits light in the visible region. That is, it can be said that the layer is made of a resin that is transparent to light in the visible region. As a result, the resin layer 12 can transmit the light incident on the resin layer 12 from the surface on the support 11 side to the multilayer film layer 13. Examples of the light in the visible region include light in the wavelength range of 360 nm or more and 830 nm or less. Further, as the resin transparent to light in the visible region, for example, a photocurable resin, a thermosetting resin, and a thermoplastic resin can be adopted. Further, on the surface of the resin layer 12 on the multilayer film layer 13 side, a concavo-convex structure including a plurality of irregularly arranged convex portions 12a and a plurality of concave portions 12b which is a region between the plurality of convex portions 12a (hereinafter, , Also referred to as "second uneven structure 12c").

The multilayer film layer 13 is a layer in which the refractive indexes of adjacent layers are different from each other. For example, the high refractive index layer 13a and the low refractive index layer 13b having a refractive index smaller than that of the high refractive index layer 13a may be alternately laminated. In FIG. 1, the resin layer 12 is in contact with the high refractive index layer 13a, and the anchor layer 14 is in contact with the low refractive index layer 13b. The high refractive index layer 13a and the low refractive index layer 13b are formed of a material that transmits light in the visible region, that is, a material that is transparent to light in the visible region. As a material that is transparent to light in the visible region, for example, a dielectric thin film can be adopted. As the dielectric thin film, for example, an inorganic material or an organic material can be adopted. Inorganic materials are particularly preferable because they have a high density and tend to have a higher refractive index than organic materials. Further, since the inorganic material has little thermal change, it is easy to form a high-quality multilayer film layer 13 by physically depositing or chemically depositing a thin layer. The material of the high refractive index layer 13a and the material of the low refractive index layer 13b are not limited as long as the refractive index of the high refractive index layer 13a is higher than the refractive index of the low refractive index layer 13b. However, the larger the difference in refractive index between the high refractive index layer 13a and the low refractive index layer 13b, the higher the intensity of reflected light can be obtained with a smaller number of layers. Therefore, for example, when an inorganic material is used as the material of the high refractive index layer 13a and the material of the low refractive index layer 13b, the material of the high refractive index layer 13a is titanium dioxide (TiO ₂ ) and the low refractive index layer 13b is used. The material is preferably silicon dioxide (SiO ₂ ).
Here, the inorganic compound is hard but brittle. Therefore, for example, when an inorganic material is used as the material of the high refractive index layer 13a and the material of the low refractive index layer 13b, the multilayer film layer 13 is more externally stimulated (plate during transfer) than when an organic material is used. The configuration is even more vulnerable to pressure and tensile stress during peeling.

Further, the multilayer film layer 13 has a shape that follows the second uneven structure 12c of the resin layer 12 so as to cover the entire surface of the resin layer 12 on the multilayer film layer 13 side with a constant film thickness. Further, the multilayer film layer 13 is discontinuous at the boundary between the portion on the convex portion 12a and the portion on the concave portion 12b of the resin layer 12, but the portion on the convex portion 12a and the portion on the concave portion 12b of the resin layer 12 The materials, film thicknesses, and stacking orders of the layers constituting the multilayer film layer 13 are the same in each of the above. Specifically, the surface of the multilayer film layer 13 on the resin layer 12 side (that is, the surface on the support 11 side) has an uneven structure in which the unevenness of the second uneven structure 12c of the resin layer 12 is inverted (hereinafter,). , Also referred to as "first uneven structure 13c"). In other words, it can be said that the surface of the resin layer 12 on the multilayer film layer 13 side has a second uneven structure 12c having unevenness in which the unevenness of the first uneven structure 13c is inverted. Further, the surface of the multilayer film layer 13 on the anchor layer 14 side (that is, the surface opposite to the surface on the resin layer 12 side) has a third unevenness having a plurality of concave portions following the second uneven structure 12c of the resin layer 12. It has a structure 13d.

With such a configuration, when the light transmitted through the resin layer 12 is incident, the multilayer film layer 13 reflects and reflects the light at each interface between the high refractive index layer 13a and the low refractive index layer 13b of the multilayer film layer 13. As a result of causing interference with the light and changing the traveling direction due to irregular irregularities on the outermost surface of the multilayer film layer 13, light in a specific wavelength range is emitted at a wide angle. In other words, the multilayer film layer 13 is configured so that the reflectance of the light incident on the multilayer film layer 13 in a specific wavelength range is higher than the reflectance of the light in another wavelength range. I can say. The specific wavelength range is determined by the material and film thickness of the high refractive index layer 13a and the low refractive index layer 13b, and the width, height and arrangement of the unevenness.

As the film thickness of the high refractive index layer 13a and the film thickness of the low refractive index layer 13b, for example, the thickness designed by the transfer matrix method or the like can be adopted according to the desired color to be developed by the color developing sheet 10. For example, when the color-developing sheet 10 exhibits a blue color, the film thickness of the high refractive index layer 13a made of TiO ₂ is preferably about 40 nm, and the film thickness of the low refractive index layer 13b made of SiO ₂ is preferably about 75 nm.

In addition, in FIG. 1, the case where the multilayer film layer 13 is composed of 10 layers in which the high refractive index layer 13a and the low refractive index layer 13b are alternately laminated in this order from the resin layer 12 side is illustrated. However, the number of layers and the order of stacking the layers of the multilayer film layer 13 are not limited to this, and may be designed so that a desired wavelength range is emitted. For example, the low refractive index layer 13b may be arranged so as to be in contact with the resin layer 12, and the high refractive index layer 13a and the low refractive index layer 13b may be alternately laminated on the low refractive index layer 13b. Further, the layer in contact with the anchor layer 14 may be either the high refractive index layer 13a or the low refractive index layer 13b. Further, as long as the low refractive index layers 13b and the high refractive index layers 13a are alternately laminated, the materials of the layer in contact with the resin layer 12 and the layer in contact with the anchor layer 14 may be the same. Further, the multilayer film layer 13 may include three or more types of layers having different refractive indexes from each other. In other words, the multilayer film layer 13 has different refractive indexes of adjacent layers in the multilayer film layer 13, and the reflectance of the light incident on the multilayer film layer 13 in a specific wavelength range is different from that of the multilayer film layer 13. It can be said that the configuration should be higher than the reflectance in the wavelength range.

The anchor layer 14 is a layer for improving the adhesion between the light absorption layer 15 and the multilayer film layer 13. Therefore, when the multilayer film layer 13 and the light absorption layer 15 are in direct contact with each other, the anchor layer 14 is not always necessary and can be omitted. As the material of the anchor layer 14, for example, a resin that develops adhesiveness by heating and a resin that has adhesiveness at room temperature can be adopted.

The glass transition point of the anchor layer 14 is preferably higher than the glass transition point of the adhesive layer 16. For example, 25 ° C. or higher can be adopted. As a result, the anchor layer 14 becomes glassy when attached to the adherend, and can realize an appropriate hardness. As the material of the anchor layer 14, for example, a thermoplastic resin such as a polyethylene resin, a polyvinyl acetate resin, an acrylic resin, a polyamide resin, a polyester resin, a polypropylene resin, or a polyurethane resin can be adopted. In particular, polyester resin is preferable because it has high anchoring properties and can easily obtain appropriate hardness. Further, the thermoplastic resin is preferably a copolymer. By using the copolymer, it is easy to achieve both hardness and anchoring property (adhesiveness), which is suitable for protecting the multilayer film layer 13.

The light absorption layer 15 is a layer for absorbing incident light transmitted through the resin layer 12 and the multilayer film layer 13. The light absorption layer 15 contains a pigment and a binder resin. As the pigment, for example, carbon black, carbon nanotube, titanium black, black iron oxide, and black composite oxide can be adopted. Further, as the binder resin, for example, an acrylic resin, a polyester resin, a polypropylene resin, or a polyurethane resin can be adopted. In particular, polyester resin is preferable because the pigment is easily dispersed. Further, for example, when the anchor layer 14 is a polyester resin, by using the polyester resin as the binder resin of the light absorption layer 15, it is possible to suppress poor peeling between the anchor layer 14 and the light absorption layer 15 at the time of transfer, and further. , Reflection of incident light at the interface between the anchor layer 14 and the light absorbing layer 15 can be suppressed. Further, for example, by using a resin having a hydroxyl group for both the anchor layer 14 and the binder resin of the light absorption layer 15, poor peeling between the anchor layer 14 and the light absorption layer 15 during transfer due to hydrogen bonding of the hydroxyl group is performed. Can be suppressed.

The glass transition point of the light absorption layer 15 is preferably higher than the glass transition point of the adhesive layer 16. For example, 25 ° C. or higher can be adopted. As a result, the light absorption layer 15 becomes glassy when attached to the adherend, and can realize an appropriate hardness. Further, the difference between the glass transition point of the anchor layer 14 and the glass transition point of the light absorption layer 15 is preferably 0 degrees or more and 70 degrees or less. Further, 30 degrees or less is more preferable. If the difference between the glass transition points between the anchor layer 14 and the light absorption layer 15 is too large, peeling defects are likely to occur during transfer, but peeling defects can be suppressed by setting the temperature to 70 degrees or less, and further to 30 degrees or less. Therefore, the distortion of the light absorption layer 15 can also be suppressed.

The adhesive layer 16 is a layer for attaching the transfer foil 20 to the adherend. For example, a layer having a rubber-like property can be adopted when it is attached to an adherend. As the material of the adhesive layer 16, for example, a resin having tackiness at room temperature and a resin having no tackiness at room temperature but exhibiting tackiness by pressurization or heating can be adopted. The tackiness is a sticky property on the surface of the adhesive layer 16. As the resin of the adhesive layer 16, for example, a thermoplastic resin such as a polyethylene resin, a polyvinyl acetate resin, an acrylic resin, a polyamide resin, a polyester resin, a polypropylene resin, or a polyurethane resin can be adopted. Further, the resin of the adhesive layer 16 may be cured by cross-linking or the like.

The glass transition point of the adhesive layer 16 is preferably lower than the glass transition point of the anchor layer 14 and the glass transition point of the light absorption layer 15. For example, a temperature lower than 25 ° C. can be adopted. As a result, the adhesive layer 16 can exhibit appropriate tackiness when attached to the adherend.

Further, the adhesive layer 16 has not only adhesion to the multilayer film layer 13 but also absorption of incident light on the multilayer film layer 13, that is, absorption of light transmitted through the resin layer 12 and the multilayer film layer 13. It may be configured. The degree of light absorption of the adhesive layer 16 can be evaluated by the light transmittance in the visible region of the adhesive layer 16. As the light transmittance of the adhesive layer 16, for example, 50% or less can be adopted. The light transmittance of the adhesive layer 16 is preferably 40% or less, more preferably 20% or less. As the light transmittance, for example, the total light transmittance defined in JIS K7361 is measured in accordance with JIS K7361. Further, when measuring the light transmittance, the adhesive layer 16 is separated from the color-developing sheet 10 and the measurement is performed on a single adhesive layer 16.

When the adhesive layer 16 has a structure having adhesiveness and light absorption, the light absorbing material may be, for example, black such as carbon black, carbon nanotube, titanium black, black iron oxide, and black composite oxide. Inorganic pigments can be used. That is, the adhesive layer 16 is preferably a black layer containing a black inorganic pigment. In this case, the color of the adhesive layer 16 may be visually recognized as black. Further, in the color of the adhesive layer 16, the L * value specified in the L * a * b * color system specified in JIS Z 8781 is preferably a small value. Specifically, the L * value is preferably 27 or less. As a result, the light transmitted through the multilayer film layer 13 can be accurately absorbed by the adhesive layer 16. Further, the content of the resin in the adhesive layer 16 is preferably 2% by mass or more with respect to the total mass of the adhesive layer 16. When the resin content is 2% by mass or more, the light transmittance of the adhesive layer 16 can be easily adjusted to 50% or less.

Further, as shown in FIG. 2, the adhesive layer 16 has a strong adhesive layer 16a, a base material 16b, and a weak adhesive layer 16c having a weaker adhesive force than the strong adhesive layer 16a in this order from the light absorption layer 15 side. It may be a laminated three-layer structure. As a result, for example, when the user pulls the transfer foil 20, the adhesive layer 16 causes peeling between the weak adhesive layer 16c and the adherend, so that the strong adhesive layer 16a and the light absorbing layer 15 are peeled off. It can be suppressed and the transfer foil 20 can be reattached. As the adhesive layer 16 having a three-layer structure, for example, double-sided tape can be adopted. Further, as the material of the strong adhesive layer 16a and the weak adhesive layer 16c, for example, a thermoplastic resin such as a polyethylene resin, a polyvinyl acetate resin, an acrylic resin, a polyamide resin, a polyester resin, a polypropylene resin, or a polyurethane resin can be adopted. Further, as the base material 16b, for example, a resin such as a polyurethane resin, a polystyrene resin, a polyolefin resin, or a polyamide resin can be adopted.

Further, when the adhesive layer 16 has a three-layer structure, it is preferable that each of the glass transition point of the strong adhesive layer 16a and the glass transition point of the base material 16b is higher than the glass transition point of the weak adhesive layer 16c. For example, 25 ° C. or higher can be adopted. As a result, the strong adhesive layer 16a and the base material 16b become glassy when attached to the adherend, and can realize an appropriate hardness. Further, as the glass transition point of the weak adhesive layer 16c, for example, less than 25 ° C. can be adopted. As a result, the weak adhesive layer 16c can exhibit appropriate tackiness when attached to the adherend.

In addition to the above-mentioned layers, the transfer foil 20 may have a protective film (hereinafter, also referred to as “separator”) that covers the surface of the adhesive layer 16 opposite to the surface of the multilayer film layer 13 side. As a result, the separator can suppress a decrease in the adhesiveness of the adhesive layer 16 when the transfer foil 20 is stored. As the separator, for example, a stretched film or a non-stretched film can be adopted. In particular, a stretched film is preferable because it is easy to form a thin and tough film and a thin separator can be realized. As the material of the separator, for example, a thermoplastic polymer can be adopted. By adopting a thermoplastic polymer, a tough thin film can be easily produced. As the thermoplastic polymer, for example, polyester, polyethylene, polypropylene can be adopted. These thermoplastic polymers have appropriate adhesiveness and peelability to the adhesive layer 16 and can also protect the adhesive layer 16. Further, the separator may be peeled off on one side or both sides. By the peeling treatment, the peeling force from the adhesive layer 16 can be adjusted, and the peeling defect of the multilayer film layer 13 due to the peeling force when peeling the separator can be reduced.

[1-2. Structure of the second uneven structure]
Next, the configuration of the second uneven structure 12c of the resin layer 12 will be described.
FIG. 3A is a plan view of the resin layer 12 when viewed from the multilayer film layer 13 side. Further, FIG. 3 (b) is a cross-sectional view of the resin layer 12 when the resin layer 12 is broken along the line I-I of FIG. 3 (a). In FIG. 3A, dots are added to the convex portions 12a constituting the second concave-convex structure.

As shown in FIG. 3A, when viewed from the multilayer film layer 13 side, the convex portion 12a of the second concave-convex structure 12c constitutes a pattern composed of a set of a plurality of graphic elements. As a pattern consisting of a set of a plurality of graphic elements, for example, a pattern consisting of a set of a plurality of rectangles R shown by a broken line in the figure can be adopted. The rectangle R has a shape extending along the second direction Dy, and the length d2 along the second direction Dy is equal to or greater than the length d1 along the first direction Dx. As the first direction Dx and the second direction Dy, for example, two directions orthogonal to each other, which exist in a plane orthogonal to the thickness direction of the resin layer 12, can be adopted. In FIG. 3A, each of the plurality of rectangles R is arranged so that neither the first direction Dx nor the second direction Dy overlaps with each other.

Each of the plurality of rectangles R has a constant length d1 in the first direction Dx, and is arranged in the first direction Dx at an arrangement interval of the length d1. That is, they are arranged in a cycle of length d1. Further, each of the plurality of rectangles R has an irregular length d2 in the second direction Dy, and the length d2 of each rectangle R is a value selected from a population having a predetermined standard deviation. As the population, for example, a normal distribution is preferable. As a method of forming a pattern composed of a plurality of rectangles R, for example, a plurality of rectangles R (rectangles R having a length d2 distributed with a predetermined standard deviation) are tentatively spread in a predetermined region, and each rectangle R tentatively spread is spread. By determining the presence or absence of the actual arrangement of the rectangle R according to a certain probability, a method of determining the area where the rectangle R is arranged and the area where the rectangle R is not arranged can be adopted. In order to efficiently scatter the reflected light from the multilayer film layer 13, it is preferable that the length d2 has a distribution having an average value of 4.15 μm or less and a standard deviation of 1 μm or less.

The convex portion 12a is arranged in the area where the rectangle R is arranged. Further, when there are rectangles R adjacent to each other, one convex portion 12a is arranged in one region in which the regions in which the adjacent rectangles R are arranged are combined. As a result, the length of the convex portion 12a in the first direction Dx is an integral multiple of the length d1 of the rectangle R. Further, the length d1 of the first direction Dx in the rectangle R is preferably equal to or less than the wavelength of light in the visible region so that iridescent spectroscopy does not occur due to the unevenness of the multilayer film layer 13. That is, the length d1 along the first direction Dx of the rectangle R is set to be equal to or less than the sub-wavelength (or less than the wavelength range of the incident light). For example, the length d1 is preferably 830 nm or less, more preferably 700 nm or less. Further, it is more preferable that the length d1 is smaller than the peak wavelength of the light in the above-mentioned specific wavelength range reflected from the multilayer film layer 13. For example, when the color-developing sheet 10 is used to develop a blue color, the length d1 is preferably about 300 nm, and when the color-developing sheet 10 is used to develop a green color, the length d1 is preferably about 400 nm. When the color-developing sheet 10 is used to develop a red color, the length d1 is preferably about 460 nm.

Here, in order to increase the spread of the reflected light from the multilayer film layer 13, that is, to enhance the scattering effect of the reflected light, it is preferable that the uneven structure has many undulations. For example, when viewed from a position facing the surface of the resin layer 12, the ratio of the area occupied by the convex portion 12a per unit area is preferably 40% or more and 60% or less. For example, the ratio of the area occupied by the convex portion 12a per unit area is more preferably 50% when viewed from the position facing the surface of the resin layer 12. As a result, the ratio of the area of the convex portion 12a to the area of the concave portion 12b becomes 1: 1.

As shown in FIG. 3B, the height h1 of each of the plurality of convex portions 12a is constant, and the convex portions 12a have a stepped shape from the plane on which the base of the convex portions 12a is located. As the height h1 of the convex portion 12a, a desired color to be developed by the coloring sheet 10, that is, a height set according to the wavelength range of light desired to be reflected by the coloring sheet 10 can be adopted. For example, if the height h1 of the convex portion 12a is larger than the surface roughness of the multilayer film layer 13, the effect of scattering the reflected light can be obtained.

However, if the height h1 is excessively large, the scattering effect of the reflected light in the multilayer film layer 13 becomes too high, and the intensity of the reflected light tends to be low. Therefore, for example, when the reflected light is light in the visible region, the height h1 is preferably 10 nm or more and 200 nm or less. Further, for example, in the color-developing sheet 10 exhibiting blue color, the height h1 is preferably about 40 nm or more and 150 nm or less in order to obtain an effective spread of light. Further, for example, in order to prevent the scattering effect from becoming too high, the height h1 is preferably 100 nm or less.

Further, in order to suppress the interference of light caused by the reflection on the unevenness of the multilayer film layer 13, the height h1 is preferably ½ or less of the wavelength of the light in the visible region. That is, it is preferably 415 nm or less. Further, in order to suppress the interference of the light, the height h1 is more preferably 1/2 or less of the peak wavelength of the light in the specific wavelength range reflected from the multilayer film layer 13.

The rectangles R may form the pattern of the convex portions 12a by arranging the rectangles R so that a part of the two rectangles R arranged along the first direction Dx overlap each other. That is, the plurality of rectangles R may be arranged in the first direction Dx at an arrangement interval smaller than the length d1. Further, the arrangement spacing of the rectangles R does not have to be constant. In the overlapping rectangles R, one convex portion 12a is located in one region in which the regions in which the respective rectangles R are arranged are combined. In this case, the length of the convex portion 12a in the first direction Dx is different from the integral multiple of the length d1 of the rectangle R. Further, the length d1 of the rectangle R does not have to be constant. That is, in each rectangle R, the length d1 along the first direction Dx is equal to or less than the sub-wavelength, and the length d2 along the second direction Dy is equal to or greater than the length d1 along the first direction Dx. It suffices to satisfy the condition that the standard deviation of the length d2 along the second direction Dy of the plurality of rectangles R is larger than the standard deviation of the length d1 along the first direction Dx. By satisfying such conditions, the scattering effect of the reflected light in the multilayer film layer 13 can be obtained, and the light in a specific wavelength range can be observed as the reflected light from the multilayer film layer 13 at a wide angle.

As described above, the first uneven structure 13c possessed by the surface of the multilayer film layer 13 on the resin layer 12 side has unevenness in which the unevenness of the second uneven structure 12c of the resin layer 12 is inverted. Therefore, when viewed from the direction along the thickness direction of the multilayer film layer 13, the pattern formed by the recesses of the first concave-convex structure 13c is also a pattern composed of a set of a plurality of rectangles R, and the width distribution of the rectangles R is distributed. And the arrangement of the rectangle R has the same characteristics as the pattern formed by the convex portion 12a of the resin layer 12. Further, the depth of the concave portion coincides with the height h1 of the convex portion 12a and becomes constant. In other words, in the pattern formed by the recesses of the first concave-convex structure 13c, the length d1 along the first direction Dx is equal to or less than the sub-wavelength when viewed from the direction along the thickness direction of the multilayer film layer 13. A pattern including a set of a plurality of graphic elements (rectangular R) having a length d2 along the second direction Dy orthogonal to the one direction Dx equal to or longer than the length along the first direction Dx is included, and a plurality of graphic elements ( In the rectangle R), it can be said that the standard deviation of the length d2 along the second direction Dy is larger than the standard deviation of the length along the first direction Dx. Further, it can be said that the recess of the multilayer film layer 13 has a shape of being recessed by one step from the plane on which the recess opens.

[1-3. Transfer foil manufacturing method]
Next, a method for manufacturing the transfer foil 20 will be described.
First, a support 11 including at least two layers having different hardness (a pressure-resistant layer 11a and a cushion layer 11b having a hardness lower than that of the pressure-resistant layer 11a) is prepared. Subsequently, the resin layer 12 is formed on the pressure resistant layer 11a side of the support 11. As a method for forming the second uneven structure 12c of the resin layer 12, for example, a nanoimprint method can be adopted. For example, when the optical nanoimprint method is used, first, a mold which is an intaglio having the unevenness of the object to be formed is inverted, and a coating liquid containing the material of the resin layer 12 is applied to the uneven surface of the mold. As the mold material, for example, synthetic quartz or silicon can be adopted. Further, as a method for forming the unevenness of the mold, for example, known microfabrication techniques such as lithography and dry etching can be adopted. Further, as the material of the resin layer 12, for example, a photocurable resin can be adopted. Further, as a coating method of the coating liquid, for example, 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 can be adopted.

Subsequently, the support 11 is superposed on the surface of the layer made of the coating liquid, and the support 11 and the mold are pressed against each other, and light is irradiated from the side where the support 11 is located or the side where the mold is located. do. Subsequently, the layer made of the cured resin and the support 11 are released from the mold. As a result, the unevenness of the mold is transferred to the resin to form the resin layer 12 having the second unevenness structure 12c, and the laminated body composed of the support 11 and the resin layer 12 is formed.

Further, for example, the coating liquid may be applied to the surface of the support 11, the mold may be pressed against the layer made of the coating liquid formed on the support 11, and the light may be irradiated in the pressed state. Further, the thermal nanoimprint method may be used instead of the optical nanoimprint method. In this case, as the material of the resin layer 12, for example, a thermoplastic resin or a thermosetting resin can be adopted.

Subsequently, thin film layers (high refractive index layer 13a, low refractive index layer 13b) for forming the multilayer film layer 13 are alternately laminated on the surface of the resin layer 12 opposite to the support 11. Examples of the method for forming the high refractive index layer 13a and the low refractive index layer 13b include sputtering, vacuum vapor deposition, and atomic layer deposition when the high refractive index layer 13a and the low refractive index layer 13b are formed from an inorganic material. A known thin film forming technique such as the above can be adopted. Further, for example, when the high refractive index layer 13a and the low refractive index layer 13b are formed from an organic material, known techniques such as self-assembly can be adopted.

Subsequently, the anchor layer 14 is formed on the surface of the multilayer film layer 13 opposite to the resin layer 12. As a method for forming the anchor layer 14, for example, 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 can be adopted. In addition to the material of the anchor layer 14, a solvent may be mixed with the coating liquid for forming the anchor layer 14, if necessary. As the solvent, a solvent compatible with the resin of the material of the anchor layer 14 can be adopted. For example, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether, toluene, xylene, methylcyclohexane, ethylcyclohexane, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone and the like can be mentioned.

Subsequently, the light absorption layer 15 is formed on the surface of the anchor layer 14 opposite to the multilayer film layer 13. As a method for forming the light absorption layer 15, for example, 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 can be adopted. In addition to the material of the light absorption layer 15, a solvent may be mixed with the coating liquid for forming the light absorption layer 15, if necessary. As the solvent, a solvent compatible with the resin of the material of the anchor layer 14 can be adopted. For example, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether, toluene, xylene, methylcyclohexane, ethylcyclohexane, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone and the like can be mentioned.

Subsequently, the adhesive layer 16 is formed on the surface of the light absorption layer 15 opposite to the anchor layer 14. As a method for forming the adhesive layer 16, for example, 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 can be adopted. In addition to the material of the adhesive layer 16, a solvent may be mixed with the coating liquid for forming the adhesive layer 16, if necessary. As the solvent, a solvent compatible with the resin of the material of the anchor layer 14 can be adopted. For example, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether, toluene, xylene, methylcyclohexane, ethylcyclohexane, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone and the like can be mentioned. Further, for example, it is also possible to adopt a method in which the adhesive layer 16 is formed by using a film-like thermoplastic resin, that is, a hot melt film or the like, and heated by a heating type laminator to be used for adhesion.

The transfer foil 20 can be manufactured by such a procedure. According to this manufacturing method, a transfer foil 20 capable of absorbing light transmitted through the multilayer film layer 13 and having good adhesion between layers can be obtained. Further, since the second uneven structure 12c of the resin layer 12 is formed by using the nanoimprint method, a fine uneven structure is suitable and can be easily formed.

[1-4. Transfer method of color development sheet]
Next, a method of transferring the color-developing sheet 10 from the transfer foil 20 to the adherend will be described.
First, as shown in FIG. 4A, the transfer foil 20 is attached to the adherend 61 so that the adhesive layer 16 is in contact with the adherend 61. The transfer foil 20 is attached to the adherend 61, and the support 11 is directed outward. The adherend 61 is not particularly limited as long as it has a surface to which the adhesive layer 16 can be adhered. Examples of the adherend 61 include resin molded products such as cards and three-dimensional objects, and paper. Subsequently, as shown in FIG. 4B, after the transfer foil 20 is attached to the adherend 61, the support 11 is peeled off from the transfer foil 20. For example, the support 11 is peeled off by applying a pulling force to the support 11 on the opposite side of the adherend 61. At that time, by heating, pressurizing, or irradiating the transfer foil 20 with ultraviolet rays, the adhesion of the adhesive layer 16 to the adherend 61 is promoted, and the peeling of the support 11 from the color-developing sheet 10 is promoted. You may do it.

By such a procedure, the color-developing sheet 10 is transferred from the transfer foil 20 to the adherend 61, and the color-developing sheet 10 is fixed to the surface of the adherend 61. Then, a color-developing article 60 composed of the color-developing sheet 10 and the adherend 61 is obtained. By transferring the color-developing sheet 10, the design of the adherend 61 can be enhanced, and the difficulty of forgery of the adherend 61 can be enhanced.

As shown in FIG. 5, in the color-developing sheet 10 after being transferred to the adherend 61, the resin layer 12 constitutes the outermost surface exposed to the outside air, and the anchor layer 14 constitutes the adherend via the adhesive layer 16. It constitutes the outermost surface in contact with 61. The structural color exhibited by the color-developing sheet 10 is observed from the resin layer 12 side.

[1-5. Effect of the first embodiment]
Next, the effect of the first embodiment will be described.
In the first embodiment, the support 11 includes at least two layers (pressure resistant layer 11a and cushion layer 11b) having different hardnesses from each other. Therefore, by including the pressure-resistant layer 11a having a high hardness, it is possible to suppress abnormal deformation of the resin layer 12 due to printing pressure when patterning the resin layer 12 that is in direct contact with the pressure-resistant layer 11a, and it becomes easy to form a desired pattern. .. In particular, when the pressure resistant layer 11a is 20 or more in JIS K7215 standard type D, abnormal deformation of the resin layer 12 due to printing pressure can be suppressed more appropriately. On the other hand, for example, when the support 11 is composed of the cushion layer 11b alone, the resin layer 12 may be abnormally deformed when the resin layer 12 is patterned.

Further, by including the cushion layer 11b having a low hardness, the hardness of the support 11 as a whole can be reduced. Therefore, for example, after the transfer foil 20 is attached to the adherend, it is possible to prevent the multilayer film layer 13 from being damaged when the transfer foil 20 is pulled due to the transfer foil 20 being reattached. When the transfer foil 20 is attached, damage to the multilayer film layer 13 due to an external stimulus applied to the multilayer film layer 13 can be suppressed. In particular, when the cushion layer 11b is JIS K6253-3 standard type A and 95 or less, it has sufficient flexibility when the transfer foil 20 is attached to the adherend 61, so that an external stimulus applied to the multilayer film layer 13 is applied. Can be absorbed, and damage to the multilayer film layer 13 can be suppressed more appropriately.

Therefore, by forming the support 11 into a layer structure including at least a pressure-resistant layer 11a and a cushion layer 11b having different hardnesses, the resin layer 12 can be normally patterned and the impact of an external stimulus applied to the multilayer film layer 13 can be applied. Can be suppressed. That is, the resin layer 12 can be formed into a desired shape, and cracks and chips in the multilayer film layer 13 and eventually poor appearance of the color-developing sheet 10 can be suppressed.

Further, in the first embodiment, after the support 11 is peeled off, the first uneven structure 13c of the multilayer film layer 13 is covered with the resin layer 12. Further, the third uneven structure 13d of the multilayer film layer 13 is covered with the anchor layer 14, the light absorption layer 15, and the adhesive layer 16. Therefore, when the color-developing sheet 10 is transferred, the support 11 is peeled off while the multilayer film layer 13 is protected, so that the defect of the color-developing sheet 10 can be suppressed and the thickness of the color-developing sheet 10 can be reduced.

Further, in the first embodiment, the glass transition point of the anchor layer 14 sequentially laminated on the multilayer film layer 13 and the glass transition point of the light absorption layer 15 are set to 25 ° C. or higher, respectively, and then the adhesive layer 16 to be laminated. The glass transition point was set to 25 ° C. or lower. Therefore, the anchor layer 14 and the light absorption layer 15 having high hardness can protect from defects due to physical damage of the multilayer film layer 13 due to scratches and the like, and are in direct contact with the adherend 61 and have low altitude and flexibility. The adhesive layer 16 can suppress damage due to external stimuli due to bending or bending, and eventually poor appearance of the color-developing sheet 10.

Further, in the first embodiment, the cushion layer 11b is configured to have a peelability with respect to the resin layer 12. Therefore, since the support 11, that is, the support 11 which is the base material at the time of manufacturing can be peeled off after the transfer of the color-developing sheet 10, the flexibility of the color-developing sheet 10 can be improved. Therefore, even when the surface of the adherend is curved, it is easy for the color-developing sheet 10 to follow the surface of the adherend. As a result, the load applied to the color-developing sheet 10 at the time of pasting can be reduced, and the peeling of the color-developing sheet 10 after pasting can be suppressed. Further, the thickness of the color-developing sheet 10 can be reduced as compared with the case where the color-developing sheet 10 has a base material at the time of manufacture, and the portion of the color-developing article to which the color-developing sheet 10 is attached rises. Can be suppressed. Therefore, for example, when the coloring sheet 10 is used for decoration, the decorativeness can be enhanced.

Further, in the first embodiment, in the color-developing sheet 10 after transfer, the second uneven structure 12c of the multilayer film layer 13 is covered with the resin layer 12. Further, the third uneven structure 13d of the multilayer film layer 13 is covered with the anchor layer 14, the light absorption layer 15, and the adhesive layer 16. Therefore, since the first concavo-convex structure 13c and the third concavo-convex structure 13d of the multilayer film layer 13 are protected, the first concavo-convex structure 13c and the third concavo-convex structure 13d are optically compared with the case where they are exposed to the outside. Deformation and damage of the first concavo-convex structure 13c and the third concavo-convex structure 13d of the multilayer film layer 13 having a function can be suppressed.

<2. Second Embodiment>
[2-1. Structure of the second uneven structure]
Next, a second embodiment of the method for manufacturing a color-developing sheet, a color-developing article, a transfer foil, and a transfer foil will be described with reference to FIGS. 6 and 7. Hereinafter, the differences between the second embodiment and the first embodiment will be mainly described, and the same reference numerals will be given to the same configurations as those of the first embodiment, and the description thereof will be omitted.

FIG. 6A is a plan view showing only the second convex portion element of the concave-convex structure when viewed from the multilayer film layer 13 side. Further, FIG. 6 (b) is a cross-sectional view of the concave-convex structure when broken along the line II-II of FIG. 6 (a). In FIG. 6A, a dot is added to the second convex portion element. Further, FIG. 7A is a plan view of the resin layer 12 when viewed from the multilayer film layer 13 side. Further, FIG. 7 (b) is a cross-sectional view of the resin layer 12 when the resin layer 12 is broken along the line III-III of FIG. 7 (a). In FIG. 7A, dots having different densities are attached to the first convex portion element and the second convex portion element.
In the second embodiment, as shown in FIGS. 6 and 7, the structure of the second uneven structure 12c of the resin layer 12 is different from that of the first embodiment. The transfer foil 20 and the color-developing sheet 10 of the second embodiment have the same configurations as those of the first embodiment except for the configuration of the second uneven structure 12c. Specifically, the convex portion 12a of the second concave-convex structure 12c of the resin layer 12 has the same structure as the convex portion 12a of the first embodiment, and the first convex portion element 12Ea shown in FIG. 7 (a). The second convex element 12Eb extending in a band shape shown in FIG. 6B has a structure superposed on the resin layer 12 in the thickness direction.

Here, in the color-developing sheet 10 of the first embodiment, the change due to the observation angle of the color visually recognized by the scattering effect of the reflected light becomes gradual, but the color visually recognized due to the decrease in the intensity of the reflected light due to the scattering. The vividness of is likely to decrease. Depending on the application of the color-developing sheet 10, a sheet capable of observing more vivid colors at a wide observation angle may be required. On the other hand, in the color-developing sheet 10 of the second embodiment, the second convex element is arranged so that the incident light is strongly diffracted in a specific direction, and the light is scattered based on the first convex element 12Ea. Due to the effect and the light diffraction effect based on the second convex element, more vivid colors can be observed from a wide observation angle.

[2-2. Configuration of the second convex element]
Next, the configuration of the second convex portion element 12Eb included in the second concave-convex structure 12c will be described.
As shown in FIG. 6A, when viewed from the multilayer film layer 13 side, the second convex portion element 12Eb has a band shape having a constant width extending along the second direction Dy, and has a band shape having a constant width and is in the first direction. They are lined up at Dx at intervals. In other words, it can be said that the pattern formed by the second convex element 12Eb is a pattern consisting of a plurality of strip-shaped regions extending along the second direction Dy and lining up along the first direction Dx. The length d3 of the first direction Dx in the second convex element 12Eb may be the same as or different from the length d1 of the rectangle R (see FIG. 3A) that determines the pattern of the first convex element 12Ea. You may.

The arrangement spacing de of the second convex element 12Eb in the first direction Dx, that is, the arrangement spacing of the band-shaped region in the first direction Dx is at least a part of the reflected light on the surface of the uneven structure formed by the second convex element 12Eb. Is set to be observed as primary diffracted light. The primary diffracted light is diffracted light having a diffraction order m of 1 or -1. That is, when the incident angle of the incident light is θ, the reflection angle of the reflected light is φ, and the wavelength of the diffracted light is λ, the arrangement interval de is set so as to satisfy de ≧ λ / (sin θ + sin φ). For example, when targeting visible light with λ = 360 nm, the arrangement spacing de of the second convex element 12Eb may be 180 nm or more. That is, the array spacing de may be ½ or more of the minimum wavelength in the wavelength range included in the incident light. The arrangement spacing de is along the first direction Dx between the ends located on the same side (right side in FIG. 7A) of the ends of the two second convex elements 12Eb adjacent to each other. The distance.

Further, the periodicity of the pattern formed by the second convex portion element 12Eb is reflected in the periodicity of the second uneven structure 12c of the resin layer 12, and is reflected in the periodicity of the first uneven structure 13c on the outermost surface of the multilayer film layer 13. It will be reflected. Therefore, when the arrangement spacing de of the plurality of second convex element 12Ebs is constant, the reflected light having a predetermined wavelength is predetermined from the multilayer film layer 13 by diffraction on the outermost surface of the multilayer film layer 13. It is emitted at the angle of. Because the light reflection intensity due to diffraction is very strong as compared with the reflection intensity of the reflected light generated by the light scattering effect based on the convex portion 12a of the first embodiment (the first convex portion element 12Ea of the second embodiment). Light having a brilliance such as metallic luster is visually recognized, but on the other hand, spectroscopy occurs due to diffraction, and the visually recognized color changes according to a change in the observation angle.

Therefore, for example, even if the structure of the first convex portion element 12Ea is designed so that the color-developing sheet 10 exhibiting blue color is obtained, if the arrangement spacing de of the second convex portion element 12Eb is set to a constant value of about 400 nm to 5 μm, Depending on the observation angle, light due to strong green to red surface reflection due to diffraction is observed. Further, for example, when the arrangement interval de of the second convex element 12Eb is increased to about 50 μm, the range of the angle at which the light in the visible region is diffracted becomes narrow, so that the color change due to the diffraction becomes difficult to visually recognize. Light with a brilliance such as metallic luster is observed only at a specific viewing angle. On the other hand, for example, the arrangement interval de is not set to a constant value, and the pattern of the second convex element 12Eb is a pattern in which a plurality of periodic structures having different periods are superimposed, so that the reflected light due to diffraction has a plurality of patterns. Since the light of the wavelength is mixed, it is difficult to visually recognize the dispersed light having high monochromaticity. Therefore, bright and glossy colors are observed at a wide observation angle. When the sequence spacing de is not constant, for example, the sequence spacing de is selected from the range of 360 nm or more and 5 μm or less, and the average value of the sequence spacing de of the plurality of second convex element 12Eb is the wavelength included in the incident light. It may be set to 1/2 or more of the minimum wavelength in the region.

However, as the standard deviation of the arrangement spacing de increases, the arrangement of the second convex element 12Eb becomes irregular and the scattering effect becomes dominant, making it difficult to obtain strong reflection due to diffraction. Therefore, the arrangement spacing de of the second convex portion element 12Eb is such that the reflected light due to diffraction is in the same range as the range in which the light spreads, depending on the angle at which the light spreads due to the light scattering effect based on the first convex portion element 12Ea. It is preferable to determine that it is emitted. For example, when the reflected blue light is emitted in a range of ± 40 ° with respect to the incident angle, the average value of the array spacing de is 1 μm or more and 5 μm or less in the pattern of the second convex element 12Eb. Set so that the standard deviation is about 1 μm. By setting the arrangement interval de as such, it is possible to emit the reflected light by diffraction at an angle similar to the angle at which the light spreads due to the light scattering effect based on the first convex portion element 12Ea.

That is, the concavo-convex structure based on the second convex portion element 12Eb is different from the second concavo-convex structure 12c of the first embodiment in which light in a specific wavelength range is diffracted and extracted, and the unevenness is used by dispersing the arrangement interval de. It can be said that it is a structure for emitting light in various wavelength ranges into a predetermined angle range.

Further, in order to cause a diffraction phenomenon having a longer period, a square region having a side of 10 μm or more and 100 μm or less is set as a unit region, and in the pattern of the second convex element 12Eb for each unit region, the array spacing de is the average value thereof. May be 1 μm or more and 5 μm or less, and the standard deviation may be about 1 μm. It should be noted that the plurality of unit regions may include regions in which the sequence spacing de is a constant value included in the range of 1 μm or more and 5 μm or less. Even if there is a unit region in which the sequence spacing de is constant, if the sequence spacing de has a variation of about 1 μm in the standard deviation in any of the unit regions adjacent to this unit region, the resolution of the human eye. In, the same effect as the configuration in which the arrangement spacing de varies in all unit regions can be expected.

Note that FIG. 6A shows a case where the second convex element 12Eb has periodicity due to the arrangement interval de only in the first direction Dx. However, the light scattering effect based on the first convex element 12Ea mainly acts on the reflected light in the direction along the first direction Dx when viewed from the position facing the surface of the multilayer film layer 13. , It may also affect a part of the reflected light in the direction along the second direction Dy. Therefore, the second convex element 12Eb may also have periodicity in the second direction Dy. That is, the pattern of the second convex portion element 12Eb may be a pattern in which a plurality of strip-shaped regions extending in the second direction Dy are arranged along each of the first direction Dx and the second direction Dy.

In such a pattern of the second convex element 12Eb, for example, the average value of each of the arrangement interval de along the first direction Dx and the arrangement interval along the second direction Dy of the band-shaped region is 1 μm or more. It suffices to have a variation such that it is 100 μm or less. Further, the average value of the array spacing de along the first direction Dx depends on the difference between the influence of the light scattering effect based on the first convex element 12Ea on the first direction Dx and the influence on the second direction Dy. And the mean value of the sequence spacing along the second direction Dy may be different from each other, and further, the standard deviation of the sequence spacing de along the first direction Dx and the standard deviation of the sequence spacing along the second direction Dy. The deviations may be different from each other.

The height h2 of the second convex portion element 12Eb may be larger than the surface roughness of the multilayer film layer 13 on the convex portion 12a and the concave portion 12b. However, as the height h2 becomes larger, the diffraction effect based on the second convex portion element 12Eb becomes dominant in the effect of the uneven structure on the reflected light, and the light scattering effect based on the first convex portion element 12Ea is obtained. It becomes difficult to be damaged. Therefore, the height h2 is preferably about the same as the height h1 of the first convex element 12Ea, and the height h2 may be the same as the height h1. For example, the height h1 of the first convex element 12Ea and the height h2 of the second convex element 12Eb are each preferably 10 nm or more and 200 nm or less, and in the blue color-developing sheet 10, they are 10 nm or more and 150 nm or less. It is preferable to have.

[2-3. Structure of the second convex part structure]
Next, the configuration of the second uneven structure 12c of the resin layer 12 will be described.
As shown in FIG. 7A, when viewed from the multilayer film layer 13 side, the patterns formed by the convex portion 12a are the first pattern, which is the pattern formed by the first convex portion element 12Ea, and the second convex portion. It is a pattern in which the second pattern, which is a pattern formed by the part element 12Eb, is superimposed. That is, in the region where the convex portion 12a is located, the region S1 composed of only the first convex portion element 12Ea, the region S2 in which the first convex portion element 12Ea and the second convex portion element 12Eb overlap, and the second A region S3 composed of only the two convex element 12Eb is included. In FIG. 7A, the first convex portion element 12Ea and the second convex portion element 12Eb are overlapped so that their ends are aligned in the first direction Dx, but the present invention is not limited to this. , The end of the first convex element 12Ea and the end of the second convex element 12Eb may be staggered and overlapped.

As shown in FIG. 7B, in the region S1, the height of the convex portion 12a is the height h1 of the first convex portion element 12Ea. Further, in the region S2, the height of the convex portion 12a is the total value of the height h1 of the first convex portion element 12Ea and the height h2 of the second convex portion element 12Eb. Further, in the region S3, the height of the convex portion 12a is the height h2 of the second convex portion element 12Eb. As described above, the convex portion 12a includes the first convex portion element 12Ea having a predetermined height h1 in which the projected image of the resin layer 12 in the thickness direction constitutes the first pattern, and the projected image in the thickness direction. Has a multi-stage shape in which the second convex element 12Eb having a predetermined height h2 constituting the second pattern is overlapped in the height direction.

The pattern formed by the first convex portion element 12Ea and the pattern formed by the second convex portion element 12Eb may be arranged so that the first convex portion element 12Ea and the second convex portion element 12Eb do not overlap. .. Even with such an arrangement, the light scattering effect based on the first convex element 12Ea and the light diffraction effect based on the second convex element 12Eb can be obtained. However, if the first convex element 12Ea and the second convex element 12Eb are arranged so as not to overlap each other, the area in which the first convex element 12Ea can be arranged per unit area becomes small, and light is scattered. The effect may be reduced. Therefore, in order to enhance the light scattering effect and the diffraction effect based on the first and second convex element elements 12Ea and 12Eb, as shown in FIG. 7B, the first convex element 12Ea and the second convex element 12Ea and the second convex. It is preferable that the convex portion 12a is formed into a multi-stage shape by overlapping the partial element 12Eb.

As described above, according to the color-developing sheet 10 of the second embodiment, the light diffusion phenomenon caused by the first convex portion element 12Ea and the light diffraction phenomenon caused by the second convex portion element 12Eb occur. Therefore, due to these synergies, the reflected light in a specific wavelength range can be observed at a wide observation angle, and the intensity of the reflected light is increased to visually recognize a glossy and vivid color.

As described above, the first uneven structure 13c possessed by the surface of the multilayer film layer 13 on the resin layer 12 side has unevenness in which the unevenness of the second uneven structure 12c of the resin layer 12 is inverted. Therefore, when viewed from the direction along the thickness direction of the multilayer film layer 13, the pattern formed by the concave portion of the first concave-convex structure 13c is composed of the first concave portion element in which the first convex portion element 12Ea is inverted. The pattern is a superposition of the pattern and the pattern formed by the second concave element in which the second convex element 12Eb is inverted. Further, the pattern formed by the first concave element, that is, the pattern formed by the projected image of the first concave element in the thickness direction of the multilayer film layer 13, is a resin regarding the distribution of the width of the rectangle R and the arrangement of the rectangle R. It has the same characteristics as the first pattern configured by the first convex element 12Ea of the layer 12. Further, the pattern formed by the second concave element, that is, the pattern formed by the projected image of the second concave element in the thickness direction of the multilayer film layer 13, is the second pattern of the resin layer 12 with respect to the width and arrangement of the band-shaped region. It has the same characteristics as the second pattern configured by the convex element 12Eb.

The recess on the surface of the multilayer film layer 13 on the resin layer 12 side has a multi-stage shape in which the first recess element and the second recess element are arranged in the depth direction. In the region composed of only the first concave element, the depth of the concave coincides with the height h1 of the first convex element 12Ea. Further, in the region where the first concave portion element and the second concave element overlap, the depth of the concave portion is the total value of the height h1 of the first convex portion element 12Ea and the height h2 of the second convex portion element 12Eb. Matches with. Further, in the region composed of only the second concave portion element, the depth of the concave portion coincides with the height h2 of the second convex portion element 12Eb.

In other words, the patterns formed by the concave portions of the first concave-convex structure 13c are a first pattern composed of a set of a plurality of graphic elements (rectangular R) and a plurality of patterns extending along the second direction and lining up along the first direction Dx. It is a pattern in which the second pattern consisting of the band-shaped region is superimposed, and the arrangement spacing of the band-shaped region along the first direction Dx is not constant, and the average value thereof is the minimum wavelength in the wavelength region included in the incident light. The recesses of the first concavo-convex structure 13c, which are 1/2 or more, are elements in which the projected image of the multilayer film layer 13 in the thickness direction constitutes the first pattern and has a predetermined depth h1. It can be said that the projected image of the multilayer film layer 13 in the thickness direction is an element constituting the second pattern and has a multi-stage shape in which concave elements having a predetermined depth h2 are arranged in the depth direction. ..

The transfer of the color-developing sheet 10 from the transfer foil 20 of the second embodiment to the adherend is performed in the same manner as in the first embodiment. That is, as shown in FIG. 4A, after the transfer foil 20 is attached to the adherend 61 so that the adhesive layer 16 is in contact with the adherend 61, as shown in FIG. 4B. The support 11 is peeled off from the transfer foil 20. As a result, the color-developing sheet 10 is transferred from the transfer foil 20 to the adherend 61, and a color-developing article 60 composed of the color-developing sheet 10 and the adherend 61 is obtained.

In the color-developing sheet 10 after being transferred to the adherend, the resin layer 12 constitutes the outermost surface exposed to the outside air, and the anchor layer 14 constitutes the adherend via the adhesive layer 16 as in the first embodiment. It constitutes the outermost surface in contact with 61. The structural color exhibited by the color-developing sheet 10 is observed from the resin layer 12 side.

Further, also in the second embodiment, as in the first embodiment, the support 11 includes at least two layers (pressure resistant layer 11a and cushion layer 11b) having different hardnesses from each other. Therefore, for example, when patterning the resin layer 12 that is in direct contact with the high-hardness pressure-resistant layer 11a, it is possible to suppress abnormal deformation of the resin layer 12 due to printing pressure. Further, for example, when the transfer foil 20 is attached to the adherend 61, the impact of an external stimulus applied to the multilayer film layer 13 can be suppressed by the cushion layer 11b having a low hardness. Further, for example, it is possible to prevent the multilayer film layer 13 from being damaged when the transfer foil 20 is pulled due to the transfer foil 20 being reattached after the transfer foil 20 is attached to the adherend. Therefore, it is possible to suppress cracking or chipping of the multilayer film layer 13 and, by extension, poor appearance of the color-developing sheet 10.

<3. Example / Comparative Example>
Next, the above-mentioned color-developing sheet, color-developing article, transfer foil, and method for producing the transfer foil will be described with reference to specific examples and comparative examples.
[3-1. Example]
First, a mold, which is an intaglio plate used in the optical nanoimprint method, was prepared. Specifically, since light having a wavelength of 365 nm is used in the optical nanoimprint method, synthetic quartz that transmits light having this wavelength was used as the material for the mold. In forming the mold, first, a film made of chromium (Cr) was formed on the surface of the synthetic quartz substrate by sputtering, and an electron beam resist pattern was formed on the Cr film by electron beam lithography. The pattern was a pattern consisting of a set of a plurality of rectangles R. The length of the rectangle R in the first direction Dx was 300 nm, and the length of the rectangle R in the second direction Dy was a length selected from a normal distribution having an average of 2000 nm and a standard deviation of 500 nm. In the above pattern, the plurality of rectangles R are arranged so as not to overlap in the first direction. A positive type electron beam resist was used, and the film thickness was 200 nm.

Subsequently, the Cr film in the region exposed from the resist was etched by plasma generated by applying a high frequency to a mixed gas of chlorine (Cl ₂ ) and oxygen (O ₂ ). Subsequently, the synthetic quartz substrate in the region exposed from the resist and the Cr film was etched by the plasma generated by applying a high frequency to the hexafluorinated ethane gas. The etching depth of the synthetic quartz substrate was 70 nm. Subsequently, the remaining resist and Cr film were removed from the surface of the synthetic quartz substrate to obtain a synthetic quartz substrate having a concavo-convex structure corresponding to the first convex element 12Ea.

Subsequently, 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 pattern was a pattern consisting of a plurality of strip-shaped regions. The length of the band-shaped region in the first direction Dx was 200 nm, and the length of the band-shaped region in the second direction Dy was 94 μm. For each rectangular region where the length of the first direction Dx is 40 μm and the length of the second direction Dy is 94 μm, the arrangement spacing in the first direction Dx is strip-shaped with an average value of 1.5 μm and a standard deviation of 0.5 μm. The regions were arranged. A positive type electron beam resist was used, and the film thickness was 200 nm.

Subsequently, the Cr film in the region exposed from the resist was etched by plasma generated by applying a high frequency to a mixed gas of chlorine (Cl ₂ ) and oxygen (O ₂ ). Subsequently, the synthetic quartz substrate in the region exposed from the resist and the Cr film was etched by the plasma generated by applying a high frequency to the hexafluorinated ethane gas. The etching depth of the synthetic quartz substrate was 65 nm. Subsequently, after removing the remaining resist and Cr film from the surface of the synthetic quartz substrate, Optool HD-1100 (manufactured by Daikin Industries, Ltd.) was applied to the surface of the synthetic quartz substrate as a mold release agent. As a result, a concavo-convex structure corresponding to the second convex portion element 12Eb was formed, and a mold having a concavo-convex structure corresponding to the second concavo-convex structure 12 of the resin layer 12 of the second embodiment was obtained.

Subsequently, a photocurable resin (PAK-02, Toyo Gosei) was placed on the polyester film (pressure resistant layer 11a) surface of the support 11 having a two-layer structure consisting of a polyester film (pressure resistant layer 11a) and a polyurethane film (cushion layer 11b). Made) was applied. Subsequently, the surface on which the unevenness of the mold was formed was pressed against the applied photocurable resin, and light of 365 nm was irradiated from the back surface side of the mold. Subsequently, the photocurable resin was cured by irradiation with light to form the resin layer 12, and then the resin layer 12 and the support 11 were peeled off from the mold. As a result, a laminated body of the resin layer 12 having an uneven structure and the support 11 having a two-layer structure of a polyester film (pressure resistant layer 11a) and a polyurethane film (cushion layer 11b) was obtained.

Subsequently, a TiO ₂ film as a high-refractive index layer 13a having a film thickness of 40 nm and a SiO ₂ film as a low-refractive index layer 13b having a film thickness of 75 nm are formed on the uneven surface of the laminated body by vacuum deposition. The film was alternately formed to form 5 pairs of the high refractive index layer 13a and the low refractive index layer 13b, that is, the multilayer film layer 13 having 10 layers. Subsequently, a coating solution of a copolymerized polyester having a glass transition point of 60 ° C. was applied to the upper surface of the multilayer film layer 13 by a bar coating method, and the formed coating film was dried at 80 ° C. for 10 minutes to anchor. The layer 14 was formed. The film thickness of the anchor layer 14 was about 5 μm. Subsequently, a black pigment having a glass transition point of 200 ° C. was applied onto the anchor layer 14 by a bar coating method, and the formed coating film was dried at 100 ° C. for 20 minutes to form a light absorption layer 15. The film thickness of the light absorption layer 15 was about 10 μm. Subsequently, a polyurethane-based coating liquid having a glass transition point of 20 ° C. was applied onto the light absorption layer 15 by a bar coating method, and the formed coating film was dried at 80 ° C. for 1 minute to form an adhesive layer 16. .. The film thickness of the adhesive layer 16 was about 5 μm.
By such a procedure, the transfer foil 20 of the example was produced.

Subsequently, the transfer foil 20 was attached to a polypropylene adherend using a three-dimensional overlay lamination method, and then the support 11 was peeled off to obtain the colored article 60 of the example. Specifically, the adhesive layer 16 of the transfer foil 20 was placed in the molding machine toward the adherend, and the inside of the molding machine was evacuated and then heated to 160 ° C. to bring the transfer foil 20 and the adherend into contact with each other. .. In this state, the transfer foil 20 and the adherend were integrated by applying pressure from the position side of the transfer foil 20 to the atmospheric pressure. Subsequently, the support 11 was peeled off from the adherend. Then, an unnecessary part of the color-developing sheet 10 was cut off to produce a color-developing article decorated with the color-developing sheet 10.

[3-2. Comparative example]
(Comparative Example 1)
In Comparative Example 1, the support 11 made of only the polyester film (pressure resistant layer 11a) was adopted, and the transfer foil 20 of Comparative Example 1 was produced by the same process as in Example. Subsequently, the colored article of Comparative Example 1 was produced from the transfer foil 20 of Comparative Example 1 by the same method as in Example.

(Comparative Example 2)
In Comparative Example 2, the support 11 made of only the polyurethane film (cushion layer 11b) was adopted, and the transfer foil 20 of Comparative Example 1 was produced by the same process as in Example. Subsequently, the colored article of Comparative Example 1 was produced from the transfer foil 20 of Comparative Example 2 by the same method as in Example.

(Comparative Example 3)
In Comparative Example 3, the adhesive layer 16 was formed by applying a coating liquid of an acrylic resin having a glass transition point of 100 ° C. by a bar coating method and drying the formed coating film at 120 ° C. for 1 minute. For the other depths, the same process as in Example was adopted to prepare the transfer foil 20 of Comparative Example 3. Subsequently, the colored article of Comparative Example 3 was produced from the transfer foil 20 of Comparative Example 1 by the same method as in Example.

[3-3. Evaluation item]
Hereinafter, the evaluation items of Examples and Comparative Examples 1 to 3 will be described.
(First appearance observation)
The appearances of the colored articles of Examples and Comparative Examples 1 to 3 were observed, and the presence or absence of poor appearance was determined.
(Second appearance observation)
After the transfer foils 20 of Examples and Comparative Examples 1 to 3 are attached to the adherend, the transfer foil 20 is peeled off from the adherend, and the peeled transfer foil 20 is reattached to the adherend to prepare a colored article. bottom. Then, the appearance of the produced colored article was observed, and the presence or absence of poor appearance was determined.

[3-4. Evaluation results]
Table 1 is a table showing the evaluation results of Examples and Comparative Examples 1 to 3.

According to Table 1, the evaluation result of the "first appearance observation" of the example was "○". When the colored article of the example was observed, a glossy blue color was observed on the colored sheet 10, and the colored sheet 10 had no cracks or chipped appearance. On the other hand, the evaluation result of "first appearance observation" of Comparative Example 1 and Comparative Example 3 was "Δ". When the color-developed article of Comparative Example 1 was observed, a color other than blue was observed on the color-developing sheet 10, and the color-developing sheet 10 had cracks and chipped appearance defects. Further, when the colored article of Comparative Example 3 was observed, blue color was observed on the color-developing sheet 10, but cracks and chips were found to be poor in appearance on the color-developing sheet 10. In addition, the evaluation result of "first appearance observation" of Comparative Example 2 was "x". When the colored article of Comparative Example 2 was observed, a color other than blue was observed on the coloring sheet 10. As a result of observation with a scanning electron microscope (SEM), the resin layer 12 was abnormally deformed. This is because only the polyurethane film was used for the support 11, so that the support 11 could not support the resin and the resin was deformed by the printing pressure.

Further, according to Table 1, the evaluation result of the "second appearance observation" of the example was "○". When the colored article of the example was observed, a glossy blue color was observed on the color-developing sheet 10 as in the case of "first appearance observation", and there was no crack or chipped appearance defect on the color-developing sheet 10. On the other hand, the evaluation result of "second appearance observation" of Comparative Examples 1 and 2 was "x". When the colored article of Comparative Example 1 was observed, cracks and chips of the colored sheet 10 were widened, and the poor appearance was exacerbated. Since the colored article of Comparative Example 2 had already failed the "x" at the "first appearance observation", it was also "x" at the "second appearance observation". In addition, the evaluation result of "second appearance observation" of Comparative Example 3 was "Δ". When the colored article of Comparative Example 3 was observed, the cracks and chips of the colored sheet 10 were hardly spread, so that the same evaluation result as in the "first appearance observation" was obtained.

As a result, when the support 11 is configured to include at least two layers having different hardnesses (pressure resistant layer 11a and cushion layer 11b), the transfer foil 20 is pulled to reattach the transfer foil 20. It was confirmed that the multilayer film layer 13 could be prevented from being damaged.

10 ... Coloring sheet, 11 ... Support, 11a ... Pressure resistant layer, 11b ... Cushion layer, 12 ... Resin layer, 12Ea ... First convex element, 12Eb ... Second convex element, 12a ... Convex, 12b ... Concave, 12c ... Second uneven structure, 13 ... Multilayer film layer, 13a ... High refractive index layer, 13b ... Low refractive index layer, 13c ... First uneven structure, 13d ... Third uneven structure, 14 ... Anchor layer, 15 ... Light absorption Layer, 16 ... Adhesive layer, 16a ... Strong adhesive layer, 16b ... Base material, 16c ... Weak adhesive layer, 20 ... Transfer foil, 60 ... Color-developing article, 61 ... Adhesive

Claims (15)

A support and a multilayer film layer formed on the support are provided.
In the multilayer film layer, the refractive indexes of the layers adjacent to each other in the multilayer film layer are different from each other, and the light reflectance in a specific wavelength range of the incident light to the multilayer film layer is in another wavelength range. Constructed higher than the light reflectivity of
The surface of the multilayer film layer on the support side has a first uneven structure having a plurality of recesses.
When viewed from the direction along the thickness direction of the multilayer film layer, the pattern formed by the recess has a length along the first direction of the sub-wavelength or less and is in the second direction orthogonal to the first direction. A pattern consisting of a set of a plurality of graphic elements whose length along the first direction is equal to or greater than the length along the first direction is included.
In the plurality of graphic elements, the standard deviation of the length along the second direction is larger than the standard deviation of the length along the first direction.
The support is a color-developing sheet containing at least two layers having different hardnesses. Of the two layers having different hardness, the one with the lower hardness has a hardness of 95 or less in JIS K6253-3 standard type A, and the one with the higher hardness has the hardness of JIS K7215 standard. The color-developing sheet according to claim 1, wherein the type D is 20 or more. The color-developing sheet according to claim 1 or 2, wherein the layer having a higher hardness among the two layers having different hardnesses is arranged on the support side of the layer having a lower hardness. A resin layer disposed between the support and the multilayer film layer is further provided.
The surface of the resin layer on the multilayer film layer side has a second uneven structure having irregularities in which the irregularities of the first concave-convex structure of the multilayer film layer are inverted.
The surface of the multilayer film layer opposite to the surface on the resin layer side has a third concavo-convex structure having a plurality of recesses following the second concavo-convex structure of the resin layer.
The coloring sheet according to claim 3. The color-developing sheet according to any one of claims 1 to 4, wherein the depth of each of the plurality of concave portions of the first uneven structure is constant. The pattern formed by the concave portion of the first uneven structure is composed of a first pattern composed of a set of the plurality of graphic elements and a plurality of strip-shaped regions extending along the second direction and arranging along the first direction. It is a pattern in which the second pattern is superimposed.
The arrangement spacing of the band-shaped regions along the first direction is not constant, and the average value thereof is ½ or more of the minimum wavelength in the wavelength region included in the incident light.
The concave portion of the first uneven structure is an element in which the projected image of the multilayer film layer in the thickness direction constitutes the first pattern and has a predetermined depth, and the thickness of the multilayer film layer. The invention according to any one of claims 1 to 5, wherein the projected image in the direction is an element constituting the second pattern and has a multi-stage shape in which concave elements having a predetermined depth are arranged in the depth direction. Color development sheet. The color-developing sheet according to any one of claims 1 to 5.
A color-developing article comprising an adherend to which the color-developing sheet is attached. A support, a concavo-convex structure layer formed on the support and having a concavo-convex structure on a surface opposite to the support, and a multilayer having a surface shape formed on the concavo-convex structure layer and following the concavo-convex structure. A film layer, an anchor layer formed on the multilayer film layer, a light absorbing layer formed on the anchor layer, and an adhesive layer formed on the light absorbing layer are provided.
In the multilayer film layer, the refractive indexes of the layers adjacent to each other in the multilayer film layer are different from each other, and the light reflectance in a specific wavelength range of the incident light to the multilayer film layer is in another wavelength range. It is configured to be higher than the light reflectivity of
When the convex portion constituting the uneven structure is viewed from the multilayer film layer side, the pattern formed by the convex portion has a length along the first direction of a sub-wavelength or less and is orthogonal to the first direction. Includes a pattern consisting of a set of a plurality of graphic elements whose length along the second direction is equal to or greater than the length along the first direction, and the length of the plurality of graphic elements along the second direction. The standard deviation of is larger than the standard deviation of the length along the first direction.
The support is a transfer foil containing at least two layers having different hardnesses. The transfer foil according to claim 8, wherein the support is configured to be peelable from the uneven structure layer. The transfer foil according to claim 8 or 9, wherein each of the glass transition point of the anchor layer and the glass transition point of the light absorption layer is higher than the glass transition point of the adhesive layer. Each of the glass transition point of the anchor layer and the glass transition point of the light absorption layer is 25 ° C. or higher.
The transfer foil according to claim 10, wherein the glass transition point of the adhesive layer is less than 25 ° C. Claim 8 or 9 is formed by laminating a strong adhesive layer, a base material, and a weak adhesive layer having a weaker adhesive force than the strong adhesive layer in this order from the light absorption layer side. The transfer foil described in. The transfer foil according to claim 12, wherein each of the glass transition point of the strong adhesive layer and the glass transition point of the base material is higher than the glass transition point of the weak adhesive layer. Each of the glass transition point of the strong adhesive layer and the glass transition point of the base material is 25 ° C. or higher.
The transfer foil according to claim 13, wherein the glass transition point of the weak adhesive layer is less than 25 ° C. A step of forming a resin layer having a concavo-convex structure on one surface of a support,
Along the uneven structure, the multilayer film layer has different refractive indexes of the layers adjacent to each other in the multilayer film layer, and the light reflectance in a specific wavelength range of the incident light to the multilayer film layer. And the process of forming the light so that it has a higher refractive index than that of light in other wavelength regions.
A step of forming an anchor layer on a surface of the multilayer film layer opposite to the surface on the resin layer side, and
A step of forming a light absorption layer on the surface of the anchor layer opposite to the multilayer film layer,
A step of forming an adhesive layer on the surface of the light absorption layer opposite to the anchor layer is included.
In the step of forming the resin layer, the pattern formed by one or more convex portions constituting the uneven structure is sub-length along the first direction when viewed from a position facing the surface of the resin layer. The plurality of figures include a pattern consisting of a set of a plurality of graphic elements having a length equal to or less than a wavelength and having a length along a second direction orthogonal to the first direction equal to or larger than a length along the first direction. In the element, the uneven structure is formed so that the standard deviation of the length along the second direction is larger than the standard deviation of the length along the first direction.
The support is a method for producing a transfer foil containing at least two layers having different hardnesses.

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