JP5477046B2 - Display body and manufacturing method thereof - Google Patents

Description

  The present invention relates to an optical technique that provides, for example, an anti-counterfeit effect, a decorative effect, and / or an aesthetic effect.

  It is desired that counterfeiting is difficult for articles such as securities, certificates, branded products, electronic devices, and personal authentication media. For this reason, such an article may support a display body having an excellent anti-counterfeit effect.

  Many of such displays include fine structures such as diffraction gratings, holograms, and lens arrays. These fine structures cause a color change in accordance with, for example, a change in observation angle. Also, these microstructures are difficult to analyze and forge. Therefore, such a display body can exhibit an excellent anti-counterfeit effect.

  However, with the recent development of embossing technology, the difficulty of producing a fine structure is decreasing. In addition, since the multilayer thin film has begun to be sold as a general packaging film, it is relatively easy to obtain an optical effect similar to the above-mentioned fine structure. Therefore, a display including a normal fine structure may have an insufficient anti-counterfeit effect.

  Therefore, in recent years, various ideas have been made to achieve a higher anti-counterfeit effect.

  For example, Patent Document 1 describes a metal case in which a coating film provided with a concavo-convex pattern by nanoimprint is provided on a metal substrate. Further, Patent Document 2 describes a substrate on which a concavo-convex pattern having a concavo-convex shape in which the width of a groove is modulated along the depth direction is formed on the surface. And in this patent document 2, in order to suppress or avoid the damage of an uneven | corrugated pattern, forming a protective film on the whole uneven | corrugated pattern is described.

  However, with the methods described in these documents, it is impossible or extremely difficult to display multiple structural colors on demand and with high efficiency. For example, it is impossible or extremely difficult to display unique information such as personal information in multiple structural colors.

  Patent Document 3 describes a recording medium in which a printing layer of either pearl printing or transparent fluorescent printing is formed on an information printing layer formed by an inkjet method. This document describes that, by adopting such a configuration, a recording medium having high security can be provided without using an ink ribbon that leaves traces of personal information or the like.

  However, the optical effect described in Patent Document 3 can be imitated relatively easily by forming a pattern using a commercially available fluorescent ink or the like. Therefore, even if the configuration described in Patent Document 3 is adopted, it is difficult to say that the anti-counterfeit effect is sufficient.

JP 2009-122773 A JP 2009-101671 A JP 2009-143192 A

  An object of the present invention is to realize a higher anti-counterfeit effect.

  According to the first aspect of the present invention, a relief structure including a plurality of concave portions arranged uniformly is included in one main surface, and the plurality of concave portions display a structural color when illuminated with white light. And a light transmission layer covering at least a part of a region of the main surface where the plurality of recesses are provided, and the light transmission layer includes a first layer of the region. At least one of the first and second partial regions so that the concave portions have different depths in the first and second partial regions, or the concave portion is completely embedded only in one of the first and second partial regions. And when the surface is illuminated with white light, different structural colors of the relief structure in a first portion corresponding to the first partial region and a second portion corresponding to the second partial region Or Includes a first light transmission layer covering the first partial region of the region, and a second light transmission layer having a refractive index different from that of the first light transmission layer and covering the second partial region of the region. A display body that displays different structural colors on the first portion corresponding to the first partial region and the second portion corresponding to the second partial region of the relief structure when illuminated with the white light. Is provided.

  According to the second aspect of the present invention, a relief structure including a plurality of concave portions arranged uniformly is included in one main surface, and the plurality of concave portions display a structural color when illuminated with white light. Preparing the foundation structure layer provided in such a manner that the recesses have different depths in the first and second partial regions provided with the plurality of recesses in the main surface, or the first And covering at least one of the first and second partial regions with a light-transmitting material so that the recess is completely embedded only in one of the second partial regions, or covering the first and second partial regions. A first portion corresponding to the first partial region of the relief structure when coated with first and second light-transmitting materials having different refractive indexes and illuminated with the white light, and In the second partial area Response to second portion and a manufacturing method different to form a light transmission layer for displaying a structural color including a display body is provided.

  According to the present invention, it is possible to achieve a higher anti-counterfeit effect.

The top view which shows schematically the display body which concerns on 1 aspect of this invention. Sectional drawing along the II-II line of the display body shown in FIG. The top view which shows roughly arrangement | positioning of the several recessed part in the display body shown in FIG.1 and FIG.2. Sectional drawing which shows the modification of the display body shown in FIG.1 and FIG.2. Sectional drawing which shows the other modification of the display body shown in FIG.1 and FIG.2. Sectional drawing which shows the other modification of the display body shown in FIG.1 and FIG.2. Sectional drawing which shows the other modification of the display body shown in FIG.1 and FIG.2. Sectional drawing which shows the other modification of the display body shown in FIG.1 and FIG.2. Sectional drawing which shows the modification of a foundation structure layer. Sectional drawing which shows the other modification of a foundation structure layer. The top view which shows schematically the display body which concerns on the other aspect of this invention. Sectional drawing which shows schematically the adhesion sticker which concerns on 1 aspect of this invention. Sectional drawing which shows schematically the transfer foil which concerns on 1 aspect of this invention. The top view which shows an example of an article | item with a display body roughly.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same referential mark is attached | subjected to the component which exhibits the same or similar function, and the overlapping description is abbreviate | omitted. Here, “visible light” means light having a wavelength in the range of 400 nm to 800 nm.

  FIG. 1 is a plan view schematically showing a display body according to one aspect of the present invention. 2 is a cross-sectional view taken along the line II-II of the display shown in FIG. 1 and 2, directions parallel to the main surface of the display body 100 and orthogonal to each other are defined as an X direction and a Y direction, and a direction perpendicular to the main surface of the display body 100 is defined as a Z direction.

  The display body 100 shown in FIGS. 1 and 2 includes a base structure layer 10, a reflection layer 20, and a light transmission layer 30. Hereinafter, the surface on the light transmitting layer 30 side with respect to the base structure layer 10 is referred to as “front surface”, and the surface on the base structure layer 10 side with respect to the light transmitting layer 30 is referred to as “back surface”.

  The display body 100 shown in FIG.1 and FIG.2 contains 1st display part DP1, 2nd display part DP2, and 3rd display part DP3. The first display portion DP1 includes both a plurality of concave portions RC and a light transmission layer 30 described later. The second display portion DP2 includes a plurality of recesses RC and does not include the light transmission layer 30. The third display portion DP3 does not include any of the plurality of recesses RC and the light transmission layer 30. The display unit DP3 may be omitted.

(Basic structure layer)
The foundation structure layer 10 includes a relief structure including a plurality of recesses RC on at least a part of one main surface. 1 and 2 illustrate a case where a plurality of recesses RC are formed only on a part of the main surface, as an example.

  The plurality of recesses RC are provided so that the relief structure displays a structural color when illuminated with white light. This structural color indication is caused by, for example, light absorption, diffraction and / or scattering. The mechanism will be described in detail later.

  The plurality of recesses RC are uniformly arranged on at least a part of the main surface. That is, in the region composed of the plurality of recesses RC, the shape, depth, average center distance, and arrangement pattern of the recesses RC are constant over the entire region. In addition, as will be described later, the foundation structure layer 10 may further include a region including other recesses that differ from the plurality of recesses RC in at least one of shape, depth, average center distance, and arrangement pattern. Good.

  As will be described later, the plurality of recesses RC may be regularly arranged or irregularly arranged. 1 and 2 illustrate a case where a plurality of recesses RC are regularly arranged as an example.

FIG. 3 is a plan view schematically showing the arrangement of a plurality of recesses in the display body shown in FIGS. 1 and 2.
As shown in FIG. 3, in the display body 100 shown in FIGS. 1 and 2, the plurality of recesses RC are two-dimensionally arranged. More specifically, the arrangement of the plurality of recesses RC forms a square lattice.

  The cross-sectional shape of the plurality of recesses RC is, for example, a tapered shape such as a V shape and a U shape, or a rectangular shape. In FIG. 2, as an example, the case where the cross-sectional shape is V-shaped is illustrated.

  The average distance between the centers of the plurality of recesses RC is, for example, in the range of 180 nm to 5000 nm, and typically in the range of 180 nm to 415 nm. The depth of the plurality of recesses RC is, for example, in the range of 180 nm to 5000 nm, and typically in the range of 180 nm to 415 nm. In addition, the average value of the ratio of the depth to the width of the openings of the plurality of recesses RC (hereinafter also referred to as aspect ratio) is within the range of 0.01 to 1.0, for example. If the aspect ratio is excessively small, there is a high possibility that the structural color displayed by the relief structure is changed or lost due to deformation due to external factors such as heat and pressure. If this aspect ratio is excessively large, it may be difficult to cause a structural color change due to the formation of a light transmission layer 30 described later. Moreover, when this aspect ratio is excessively large, the productivity of the foundation structure layer 10 may be reduced.

  The base structure layer 10 typically includes a base material and a resin layer formed thereon. As this base material, a film base material is typically used. As the film substrate, for example, a plastic film such as a polyethylene terephthalate (PET) film, a polyethylene naphthalate (PEN) film, or a polypropylene (PP) film is used. Alternatively, paper, synthetic paper, plastic multilayer paper, or resin-impregnated paper may be used as the substrate. The base material may be omitted.

  The resin layer includes a relief structure including a plurality of recesses RC on at least a part of one main surface. This resin layer is formed by the method mentioned later, for example.

  The thickness of the resin layer is, for example, in the range of 0.1 μm to 10 μm. If this thickness is excessively large, resin protrusion and / or wrinkle formation is likely to occur due to pressure during processing. If this thickness is excessively small, it may be difficult to form the desired recess RC. Further, the thickness of the resin layer is made equal to or greater than the depth of the recess RC to be provided on the main surface. This thickness is, for example, in the range of 1 to 10 times the depth of the recess RC, and typically in the range of 3 to 5 times thereof.

  The base structure layer 10 can be manufactured, for example, by pressing an original plate provided with fine convex portions against a thermosetting or radiation curable resin and curing the resin in this state. Alternatively, the basic structure layer 10 can be manufactured by pressing the original plate against a heated thermoplastic resin and cooling the resin in this state. At this time, the shape of these convex portions is a shape corresponding to the shape of the plurality of concave portions RC provided on one main surface of the foundation structure layer 10. In addition, when the roll-shaped original plate is used, continuous forming of the foundation structure layer 10 becomes easy.

  The original plate used for manufacturing the base structure layer 10 is manufactured using, for example, an electron beam drawing apparatus. If it carries out like this, the some recessed part RC mentioned above can be manufactured with high precision. Usually, a reverse plate is manufactured by transferring the concavo-convex structure of the original plate, and a duplicate plate is manufactured by transferring the concavo-convex structure of the reverse plate. Then, if necessary, a reversal plate is manufactured using the copy plate as an original plate, and the concavo-convex structure of the reverse plate is transferred to further manufacture a copy plate. In actual production, a copy obtained in this way is usually used.

  The foundation structure layer 10 can be manufactured using, for example, a “press method” disclosed in a document such as Japanese Patent No. 4194073. That is, the basic structure layer 10 can be manufactured by, for example, a method in which the above-described original plate is pressed onto a base material coated with a thermoplastic resin while applying heat. In this case, as the thermoplastic resin, for example, an acrylic resin, an epoxy resin, a cellulose resin, a vinyl resin, a mixture thereof, or a copolymer of monomers corresponding to each of them is used. To do.

  Alternatively, the foundation structure layer 10 may be manufactured by using a “casting method” disclosed in documents such as Utility Model Registration No. 2524092. That is, the basic structure layer 10 may be manufactured by, for example, a method in which a thermosetting resin is applied on a substrate, heat is applied while pressing the original plate on the substrate, and then the original plate is removed. In this case, as the thermosetting resin, for example, a urethane resin, a melamine resin, an epoxy resin, a phenol resin, a mixture thereof, or a copolymer of monomers corresponding to each of them is used. In addition, this urethane resin is obtained, for example, by adding polyisocyanate as a crosslinking agent to acrylic polyol and polyester polyol having a reactive hydroxyl group and crosslinking them.

  Alternatively, the basic structure layer 10 may be manufactured using a “photopolymer method” disclosed in a document such as Japanese Patent Application Laid-Open No. 2007-118563. The photopolymer method is a method in which a material of a radiation curable resin is poured between a flat substrate and the above original plate, and the material is cured by irradiating with radiation such as ultraviolet rays, and then the original plate is removed. This method has a higher forming accuracy of the recess RC than the pressing method or the casting method. Further, according to this method, the basic structure layer 10 that is superior in heat resistance and chemical resistance can be obtained.

  The basic structure layer 10 may be manufactured by applying a radiation curable resin material on a substrate, irradiating the material while pressing the original plate to cure the material, and then removing the original plate. Good.

The material of the radiation curable resin typically includes a polymerizable compound and an initiator.
As the polymerizable compound, for example, a compound capable of photo radical polymerization is used. As a compound capable of radical photopolymerization, for example, a monomer, oligomer or polymer having an ethylenically unsaturated bond or an ethylenically unsaturated group is used. Alternatively, as a compound capable of photo radical polymerization, 1,6-hexanediol, neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol pentaacrylate and dipentaerythritol hexaacrylate Monomers such as epoxy acrylate, urethane acrylate and polyester acrylate, or polymers such as urethane-modified acrylic resin and epoxy-modified acrylic resin may be used.

  When a compound capable of photoradical polymerization is used as the polymerizable compound, a photoradical polymerization initiator is used as the initiator. Examples of the photo radical polymerization initiator include benzoin compounds such as benzoin, benzoin methyl ether and benzoin ethyl ether, anthraquinone compounds such as anthraquinone and methylanthraquinone, acetophenone, diethoxyacetophenone, benzophenone, hydroxyacetophenone, 1-hydroxy Phenyl ketone compounds such as cyclohexyl phenyl ketone, α-aminoacetophenone and 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, benzyl dimethyl ketal, thioxanthone, acylphosphine oxide, or Michler's ketone Is used.

  Alternatively, a compound capable of photocationic polymerization may be used as the polymerizable compound. As the compound capable of photocationic polymerization, for example, a monomer, oligomer or polymer having an epoxy group, an oxetane skeleton-containing compound, or vinyl ethers are used.

  When a compound capable of photocationic polymerization is used as the polymerizable compound, a photocationic polymerization initiator is used as the initiator. As this photocationic polymerization initiator, for example, an aromatic diazonium salt, an aromatic iodonium salt, an aromatic sulfonium salt, an aromatic sulfonium salt, an aromatic phosphonium salt, or a mixed ligand metal salt is used.

  Alternatively, a mixture of a compound capable of photoradical polymerization and a compound capable of photocationic polymerization may be used as the polymerizable compound. In this case, as the initiator, for example, a mixture of a radical photopolymerization initiator and a cationic photopolymerization initiator is used. Alternatively, in this case, a polymerization initiator that can function as an initiator for both photoradical polymerization and photocationic polymerization may be used. As such an initiator, for example, an aromatic iodonium salt or an aromatic sulfonium salt is used.

  The ratio of the initiator to the radiation curable resin is, for example, in the range of 0.1 to 15% by mass.

  Radiation curable resins are release agents, sensitizing dyes, dyes, pigments, polymerization inhibitors, leveling agents, antifoaming agents, anti-sagging agents, adhesion improvers, coating surface modifiers, plasticizers, nitrogen-containing compounds, epoxies It may further contain a crosslinking agent such as a resin, or a combination thereof. The radiation curable resin may further contain a non-reactive resin in order to improve its moldability. As this non-reactive resin, for example, a thermoplastic resin and / or a thermosetting resin described later can be used.

  The basic structure layer 10 may be manufactured by forming a single layer particle film in which fine particles are two-dimensionally arranged on a base material. When the basic structure layer 10 is manufactured by forming a single layer particle film on a base material, it is possible to form a plurality of concave portions RC more stably and with higher productivity as compared with other cases. Become.

  This single-layer particle film is formed, for example, by immersing the base material in a solution containing fine particles and then gradually pulling up the base material at a constant speed. Alternatively, this single-layer particle film may be formed by applying an ink containing fine particles and a binder resin on a substrate while strictly controlling the application amount.

  Typically, spherical fine particles are used as the fine particles. This makes it easy to regularly arrange the fine particles on the substrate. Alternatively, as the above fine particles, amorphous particles having a small variation in particle diameter may be used. In this way, since the single-layer particle film has a periodic structure that depends on the arrangement of the particles, the light corresponding to the structural color and the scattered light due to the irregular particle shape can be emitted to the plurality of recesses RC. .

  The plurality of recesses RC may be formed by forming recesses as a precursor structure of these recesses RC and then deforming these recesses with heat and / or pressure. For example, these recesses RC may be formed by first forming deeper recesses and then crushing these recesses. When such a method is employed, for example, it is possible to relatively easily adjust the aspect ratio of the plurality of recesses RC on demand.

(Reflective layer)
The reflective layer 20 covers at least a part of the region where the plurality of recesses RC are provided in the main surface of the foundation structure layer 10. The reflective layer 20 has a refractive index different from that of the light transmitting layer 30 described later.

  Typically, a material having a refractive index difference of 0.2 or more as a material of the reflective layer 20 (hereinafter also referred to as a reflective material) and a material of the light transmissive layer 30 (hereinafter also referred to as a light transmissive material). use. If this difference is excessively small, reflection at the interface between the reflective layer 20 and the light transmitting layer 30 may be difficult to occur.

  A metal material is typically used as the reflective material. Examples of the metal material include at least one selected from the group consisting of Al, Sn, Cr, Ni, Cu, Au, Ag, and alloys thereof.

  As a reflective material having relatively high transparency (hereinafter also referred to as a transparent reflective material), ceramic materials or organic polymer materials listed below may be used. In addition, the numerical value in the parenthesis described after the following chemical formula or compound name means the refractive index of each material.

That is, as a ceramic material, for example, Sb ₂ O ₃ (3.0), Fe ₂ O ₃ (2.7), TiO ₂ (2.6), CdS (2.6), CeO ₂ (2.3 ), ZnS (2.3), PbCl ₂ (2.3), CdO (2.2), Sb ₂ O ₃ (5), WO ₃ (5), SiO (5), Si ₂ O ₃ (2. 5), In ₂ O ₃ (2.0), PbO (2.6), Ta ₂ O ₃ (2.4), ZnO (2.1), ZrO ₂ (5), MgO (1), SiO ₂ (1.45), Si ₂ O ₂ (10), MgF ₂ (4), CeF ₃ (1), CaF ₂ (1.3 to 1.4), AlF ₃ (1), Al ₂ O ₃ (1 ) Or GaO (2) can be used. For example, polyethylene (1.51), polypropylene (1.49), polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49) or polystyrene (1.60) is used as the organic polymer material. be able to.

  When a transparent reflective material is used, the total light transmittance for light in the visible range of the reflective layer 20 is typically 50% or more. In this way, it is possible to record print information such as a face photograph, characters and patterns on the back side of the reflective layer 20 and make the information visible. The “total light transmittance” is a measured value based on Japanese Industrial Standard JIS K7361-1.

  As the reflective material, a material having durability suitable for practical use can be appropriately selected from the materials listed above. Alternatively, the materials mentioned above may be mixed and used, or layers made of the respective materials may be stacked.

  The reflective layer 20 is formed by, for example, a dry coating method. Examples of the dry coating method include a vacuum deposition method, a sputtering method, and a CVD (Chemical Vapor Deposition) method. When the dry coating method is employed, a thin film having high thickness uniformity can be formed relatively easily.

  The reflective layer 20 may be formed by a wet coating method. In this case, first, an ink containing fine particles of the above-described reflective material, a solvent, and a binder is prepared. Then, this ink is applied onto the base structure layer 10 by a printing method such as an ink jet method, a gravure method, a micro gravure method, a roll coating method, and a dip coating method. In this way, the reflective layer 20 is formed. The ink containing the fine particles of the reflective material may not contain a binder.

  When the reflective layer 20 is formed using an ink containing fine particles of a reflective material, the average particle diameter of the fine particles is typically not more than one fifth of the average distance between the centers of the plurality of recesses RC and the depth. And If the average particle size is excessively large, the desired reflectance may not be obtained, or the plurality of concave portions RC may disappear due to the reflective layer 20 and it may be difficult to display the structural color. Here, the “average particle diameter” is an average particle diameter measured by a dynamic scattering method.

  The reflective layer 20 may have a multilayer configuration. For example, the reflective layer 20 may be a multilayer interference film composed of a plurality of layers having different refractive indexes.

  The thickness of the reflective layer 20 is made smaller than the depths of the plurality of recesses RC, and is typically less than or equal to one half of this depth. If this thickness is excessively large, the optical effect resulting from the formation of the light transmission layer 30 described later may be insufficient.

  The reflective layer 20 may be omitted. However, when the reflective layer 20 is provided, an image with better visibility can be displayed on the display body 100. Further, when the reflective layer 20 is provided, it is possible to make it difficult for the plurality of recesses RC to be damaged. When the reflective layer 20 is omitted, the refractive index of the basic structure layer 10 and the light transmission layer 30 described later are made different from each other.

  In addition, when the reflective layer 20 is abbreviate | omitted or the reflective layer 20 is formed using a transparent reflective material, it becomes possible to provide the layer which recorded printing information in the back side of the light transmissive layer 30 mentioned later. Therefore, in this case, the display body 100 can be applied to an anti-counterfeit oversheet that can be used for an ID (Identification) card, a passport, and the like.

(Light transmission layer)
The light transmission layer 30 faces at least a part of a region where the plurality of recesses RC are provided on the main surface of the foundation structure layer 10 with the reflection layer 20 interposed therebetween. Alternatively, the light transmission layer 30 covers at least a part of the region. In FIGS. 1 and 2, as an example, a case where the light transmission layer 30 faces only a part of the region with the reflective layer 20 interposed therebetween is illustrated. In the display body 100 shown in FIGS. 1 and 2, a portion of the region facing the light transmission layer 30 is referred to as a first partial region PR1, and a portion of the region other than the first partial region PR1 is a second partial region. Called PR2. The partial areas PR1 and PR2 correspond to the display parts DP1 and DP2, respectively.

  In the display body 100 shown in FIGS. 1 and 2, the thickness of the light transmission layer 30 at the position corresponding to the bottom of the plurality of recesses RC is compared with the depth of the plurality of recesses RC when the light transmission layer 30 is not present. Smaller than. Further, the thickness of the light transmission layer 30 at a position corresponding to the bottom of the plurality of recesses RC is larger than the thickness of the light transmission layer 30 at a position between the plurality of recesses RC adjacent to each other.

  The light transmission layer 30 has transparency to visible light. The total light transmittance for light in the visible range of the light transmission layer 30 is, for example, 30% or more, typically 50% or more, and particularly preferably 80% or more. If this transmittance is excessively small, there is a possibility that an optical effect described later due to the light transmission layer 30 is difficult to visually recognize. The “total light transmittance” is a measured value based on Japanese Industrial Standard JIS K7361-1.

  The light transmission layer 30 has a refractive index different from that of the reflection layer 20, and also has a refractive index different from that of an external region adjacent to the reflection layer 20 with the light transmission layer interposed therebetween. The light transmission layer 30 is made of a light transmission material and includes, for example, an organic material, an inorganic material, an organic-inorganic composite material, or a mixture thereof.

  Examples of the organic material include an acrylic resin, a polyester resin, a urethane resin, an epoxy resin, a melamine resin, a mixture thereof, and a monomer copolymer or a two-component cured product corresponding to each of these.

  Examples of the inorganic material include metal alkoxides such as ethyl silicate, propyl silicate, and butyl silicate.

  As an organic inorganic composite material, the copolymer of the monomer corresponding to the said organic material and the monomer corresponding to the said inorganic material is mentioned, for example.

Fine particles may be dispersed in the light transmission layer 30. In this way, for example, the refractive index of the light transmission layer 30 can be adjusted to a desired value.
For example, fine particles made of an organic material are used as the fine particles. Examples of the organic material include acrylic resin, urethane resin, melamine resin, epoxy resin, vinyl chloride resin, and vinyl acetate resin.

  Further, fine particles made of an inorganic material may be used as the fine particles. Examples of the inorganic material include aluminum oxide, titanium oxide, cerium oxide, yttrium oxide, zinc oxide, silicon oxide, tin oxide, copper oxide, iron oxide, manganese oxide, holmium oxide, bismuth oxide, cobalt oxide, and ITO (Indium). And oxides such as Tin Oxide), metals such as gold, silver, copper, nickel, cobalt, titanium, iron, aluminum, magnesium, chromium, and tin and alloys thereof, and lanthanoids and compounds thereof.

  Alternatively, fine particles made of an organic-inorganic composite material may be used as the fine particles. Examples of such fine particles include fine particles made of a mixture containing an organic material and an inorganic material, and fine particles containing an organic material and an inorganic material and having a core-shell structure.

  Furthermore, hollow particles containing air or other gas inside may be used as the fine particles. The hollow particles may be obtained by dispersing air or gas as bubbles in the light transmission layer 30.

  When fine particles are dispersed in the light transmission layer 30, the average particle size of these fine particles is, for example, 400 nm or less, and typically 100 nm or less. If this average particle size is excessively large, it is difficult to visually recognize the optical effect described later due to the light transmission layer 30 due to excessive light scattering caused by these fine particles. Here, the “average particle diameter” is an average particle diameter measured by a dynamic scattering method.

  The light transmission layer 30 is typically colorless. When such a configuration is adopted, an optical effect described later due to the light transmission layer 30 becomes particularly remarkable. In addition, this makes it relatively difficult to recognize the presence of the light transmission layer 30, and can further improve the forgery prevention effect of the display body 100.

  The light transmission layer 30 may be colored. By adopting such a configuration, it is possible to express an image with a more complex color tone by combining the color of the light transmission layer 30 and the structural color. For example, the light transmission layer 30 may further include a color material. Examples of the color material include pigments and dyes. This coloring material may be an extender pigment.

  As apparent from FIGS. 1 and 2, the light transmission layer 30 can be the outermost layer of the display body 100. Therefore, it is preferable that the light transmission layer 30 has a high surface hardness and is excellent in wear and scratching properties. Examples of the material of the light transmission layer 30 having such characteristics include, for example, a thermoplastic resin, an ionizing radiation curable resin, a two-component curable resin, a thermosetting resin, and a hard coat material containing a silicone resin and a fluororesin. Is mentioned. These materials may further contain a wax and / or a lubricant.

  The light transmission layer 30 is formed, for example, by printing a light transmission material. Examples of this printing method include inkjet printing, gravure printing, microgravure printing, roll coat printing, and flexographic printing. These printings are performed by, for example, applying an ink or a dispersion containing the material of the light transmission layer 30 on the base structure layer 10 or the reflective layer 20 and then drying them.

  The light transmission layer 30 may be formed by a method other than the printing method. For example, the light transmission layer 30 may be formed by a transfer method or a lamination method. In the case where personal information or the like is displayed by forming the light transmissive layer 30, the light transmissive layer 30 may be formed by a method that does not use an ink ribbon or the like that may leave a trace of the information, for example, an ink jet printing method. desirable.

(Optical effect)
Hereinafter, optical effects that can be exhibited by the display body 100 will be described.
First, as the premise, the optical effect resulting from only the basic structure layer 10 or the laminated structure of the basic structure layer 10 and the reflective layer 20 will be described. Hereinafter, for simplicity, the case where the reflective layer 20 is omitted will be described.

  As described above, a relief structure including a plurality of concave portions RC arranged uniformly is provided on one main surface of the foundation structure layer 10. The plurality of recesses RC are provided so that the relief structure displays a structural color when illuminated with white light.

  The structural color displayed by the relief structure is, for example, a structural color based on light absorption. Such a structural color is absorbed, for example, by selective absorption of light, that is, in a plurality of recesses RC with higher efficiency than light in a specific wavelength region among light in the visible region compared to light in other wavelength regions. Can be displayed. That is, when the relief structure is illuminated with white light, light in a specific wavelength region is absorbed in the plurality of recesses RC, and all or part of light in other wavelength regions is reflected, diffracted, or reflected from the plurality of recesses RC. It is scattered and emitted. Thereby, a specific structural color can be displayed on the relief structure.

  In order to display a structural color based on light absorption in the relief structure, for example, the following configuration is adopted. That is, each of the plurality of recesses RC has a shape tapered toward the bottom. When such a configuration is adopted, the light incident on the recesses RC may be reflected several times in each recess RC. Then, a part or all of the reflected light is gradually attenuated by repeated reflection without being emitted to the outside of the recess RC.

  For example, when the plurality of recesses RC are designed so that all or very much of the illumination light does not return to the front of the plurality of recesses RC when the relief structure is illuminated with white light, Of these, a black structural color can be displayed in the region where the recess RC is provided. Alternatively, when the plurality of recesses RC are designed such that when the relief structure is illuminated with white light, only light in a part of the wavelength region of the visible light returns to the front of the recesses RC, the basic structure layer 10 The structural color corresponding to the wavelength region can be displayed in the region where the recess RC is provided in the main surface.

  When a structural color based on light absorption is displayed on the relief structure, this structural color can be changed as appropriate by adjusting the average center-to-center distance and / or aspect ratio of the plurality of recesses RC, for example. For example, a structural color closer to black can be displayed by increasing the aspect ratio of the recess RC. Further, by reducing the aspect ratio of the plurality of recesses RC, a desired structural color other than black can be displayed. For example, when the average distance between the centers of the plurality of recesses RC is 400 nm or less and the aspect ratio is greater than 0.5, a structural color close to black can be displayed on the relief structure.

  The structural color displayed by the relief structure may be a structural color based on diffraction by the plurality of concave portions RC. This structural color can be displayed, for example, by arranging these concave portions RC regularly so that these concave portions RC form a diffraction grating. In particular, if the average distance between the centers of the plurality of recesses RC is in the range of 180 nm to 830 nm, the structural color resulting from low-order diffracted light such as first-order diffracted light can be viewed with high visibility and a wide range of viewing angles. .

  The structural color displayed by the relief structure may be a structural color based on scattering by the plurality of recesses RC. This structural color can be displayed, for example, by irregularly arranging the concave portions RC. Examples of the scattering mechanism include Rayleigh scattering, Mie scattering, and diffraction scattering.

  Next, the optical effect resulting from the formation of the light transmission layer 30 will be described. Hereinafter, for the sake of simplicity, the case where the display body 100 includes only the basic structure layer 10 and the light transmission layer 30 will be described.

  In the display body 100 described with reference to FIGS. 1 to 3, the light transmission layer 30 partially covers a region of the main surface of the base structure layer 10 where the plurality of recesses RC are provided. That is, the light transmission layer 30 covers only the first partial region PR1 in the previous region. The light transmission layer 30 has a refractive index different from that of the external region adjacent thereto.

  Therefore, by providing the light transmission layer 30, the optical distance (product of the refractive index and the actual distance) in the recess RC can be changed in the first partial region PR1. That is, by providing the light transmission layer 30, for example, the effective shape, depth, opening width, and the like of the plurality of recesses RC can be changed.

  In addition, when the relief structure provided in the base structure layer 10 displays a structural color due to light absorption based on repeated reflections, the light transmissive layer 30 is provided so that light incident on the plurality of recesses RC can be converted into light. The light can be refracted at the interface between the transmission layer 30 and the external region. Therefore, in this way, it is possible to change the optical path in the concave portion RC of the repeatedly reflected light corresponding to the incident light.

  Therefore, when the light transmission layer 30 is provided, it is possible to display a structural color different from the structural color displayed only by the basic structure layer 10 on the first display portion DP1 corresponding to the first partial region PR1.

  On the other hand, in the display body 100 described with reference to FIGS. 1 to 3, the light transmission layer 30 does not cover the second partial region PR2. Therefore, the second display portion DP2 corresponding to the second partial region PR2 displays the same structural color as the structural color displayed by the basic structure layer 10.

  As described above, the light transmission layer 30 can display different structural colors on the first display portion DP1 and the second display portion DP2.

  The structural color displayed on the first display part DP1 can be freely adjusted by changing the thickness and refractive index of the light transmission layer 30 formed on the first partial region PR1. Further, the shape of the first display portion DP1 can be freely adjusted by controlling the position where the light transmission layer 30 is formed. That is, by forming the light transmission layer 30, a desired pattern can be recorded on demand.

  As described above, the light transmission layer 30 can be formed easily and with high efficiency by a printing method or the like. That is, when the configuration as described above is adopted, a desired pattern can be recorded easily and with high efficiency.

  In the display body 100 described with reference to FIGS. 1 to 3, the thickness of the light transmission layer 30 at the position corresponding to the bottom of the recess RC is compared with the depth of the recess RC when the light transmission layer 30 is not present. Smaller than. That is, the light transmission layer 30 partially fills each of the plurality of recesses RC included in the first partial region PR1. In this case, the amount of material used for the light transmission layer 30 can be reduced as compared with the case where the light transmission layer 30 completely fills each of the recesses RC. In addition, in this case, the thickness of the display body 100 can be suppressed.

  Further, in the display body 100 described with reference to FIGS. 1 to 3, the thickness of the light transmission layer 30 at the position corresponding to the bottoms of the plurality of recesses RC is the light transmission layer at the position between the adjacent recesses RC. Greater than 30 thickness. When the light transmission layer 30 is formed in this way, the effective depth of the plurality of concave portions RC can be made different between the first display portion DP1 and the second display portion DP2. In other words, this makes it possible to make the difference in the structural colors displayed by the display portions DP1 and DP2 more prominent.

  In the above, the structural color displayed by the relief structure may change depending on the illumination angle of the illumination light, the observation angle of the observer, and the like. That is, this relief structure may cause a change in color and / or brightness depending on the viewing conditions. Such a color change can be visually recognized by an observer without using a verification device, so that the effect of preventing forgery of the display body 100 can be further improved.

(Modification)
Various modifications can be made to the display body 100 described above.
FIG. 4 is a cross-sectional view showing a modification of the display body shown in FIGS. 1 and 2.
A display body 100 shown in FIG. 4 is described with reference to FIGS. 1 to 3 except that the light transmission layer 30 completely fills each of the plurality of recesses RC included in the first partial region PR1. It has the same configuration as the described display body.

  Even when such a configuration is adopted, by providing the light transmission layer 30, the optical distance along the optical path in the recess RC can be changed in the first partial region PR1. Thereby, the effective depth of several recessed part RC can be changed.

  Therefore, also in the display body 100 shown in FIG. 4, the light transmission layer 30 can display different structural colors on the first display portion DP1 and the second display portion DP2. In addition, when the light transmission layer 30 completely fills the plurality of recesses RC included in the first partial region PR1, damage to the recesses RC in the display part DP1 is relatively difficult to occur. In this case, the presence of the recess RC is relatively difficult to realize.

FIG. 5 is a sectional view showing another modification of the display body shown in FIGS. 1 and 2.
5 except that the light transmission layer 30 includes the first light transmission layer 30A and the second light transmission layer 30B formed so that the concave portions RC have different depths. The display body has the same configuration as that described with reference to FIGS.

  In the display body 100 shown in FIG. 5, the region where the plurality of recesses RC are provided in the main surface of the base structure layer 10 includes the first partial region PR1 corresponding to the first light transmission layer 30A and the second light transmission layer. The second partial region PR2 corresponding to 30B and the third partial region PR3 corresponding to the position where the light transmission layer 30 is not provided are included. Of these, the third partial region PR3 may be omitted.

  And the display body 100 shown in FIG. 5 contains 1st display part DP1, 2nd display part DP2, and 3rd display part DP3 which each respond | corresponded to partial region PR1 thru | or PR3. The display body 100 further includes a fourth display portion DP4 that does not include the recess RC. Of these, the display portions DP3 and DP4 may be omitted.

  In the display body 100 shown in FIG. 5, the light transmission layer 30 covers both the partial regions PR1 and PR2 so that the concave portions RC have different depths in the first partial region PR1 and the second partial region PR2. Yes. That is, the light transmission layer 30 includes a first light transmission layer 30A that covers the first partial region PR1, and a second light transmission layer 30B that covers the second partial region PR2.

  The materials of the light transmission layers 30A and 30B may be the same as each other or different from each other. However, in order to make the optical distances different between the light transmission layers 30A and 30B, it is preferable that the product of the refractive index and the maximum value of the thickness is different from each other. As the material of the light transmission layers 30A and 30B, for example, the same material as the light transmission material described with reference to FIGS. 1 to 3 can be used.

  When the configuration shown in FIG. 5 is adopted, different structural colors can be displayed on the display portions DP1 and DP2. Both of these structural colors are typically different from the structural colors resulting from the foundation structure layer 10 alone. Therefore, by adopting such a configuration, a more complicated optical effect can be achieved.

  In the display body 100 shown in FIG. 5, the thickness of the light transmission layers 30A and 30B at the position corresponding to the bottom of the recess RC is compared with the depth of the plurality of recesses RC when the light transmission layers 30A and 30B are not present, respectively. And smaller. In this case, the amount of the material used for the light transmitting layer 30A or 30B can be reduced as compared with the case where one or both of the light transmitting layers 30A and 30B completely fill each of the plurality of recesses RC. In this case, the thickness of the display body 100 can be suppressed.

  In the display body 100 shown in FIG. 5, the thickness of the light transmission layers 30A and 30B at the positions corresponding to the bottoms of the plurality of recesses RC is the same as the light transmission layer 30A at the position between the plurality of recesses RC adjacent to each other. And larger than 30B thickness. When the light transmission layers 30A and 30B are formed in this way, the effective depths of the plurality of recesses RC can be made different between the display portions DP1 and DP2 and the display portion DP3. In other words, this makes it possible to make the difference between the structural color displayed by the display units DP1 and DP2 and the structural color displayed by the display unit DP3 more prominent.

  The light transmissive layers 30A and 30B can be formed by the same method as described for the light transmissive layer 30 described with reference to FIGS. Therefore, also in the display body 100 shown in FIG. 5, it is possible to record a desired pattern easily, efficiently, and on demand.

FIG. 6 is a sectional view showing another modification of the display body shown in FIGS. 1 and 2.
The display body 100 shown in FIG. 6 has been described with reference to FIG. 5 except that the first light transmission layer 30A completely fills each of the plurality of recesses RC included in the first partial region PR1. It has the same configuration as the display body.

  Even when such a configuration is employed, different structural colors can be displayed on the display portions DP1 and DP2. In addition, both of these structural colors are typically different from the structural colors caused only by the base structure layer 10. Therefore, by adopting such a configuration, a more complicated optical effect can be achieved.

  In the display body 100 shown in FIG. 6, the first light transmission layer 30A completely fills each of the plurality of recesses RC included in the first partial region PR1. Therefore, the recess RC in the display portion DP1 is relatively difficult to be damaged. In this case, it is relatively difficult to realize the existence of the plurality of recesses RC included in the first partial region PR1.

  On the other hand, in the display body 100 shown in FIG. 6, the second light transmission layer 30B partially fills each of the plurality of recesses RC included in the second partial region PR2. Therefore, the amount of material used for the second light transmission layer 30B can be reduced as compared with the case where the second light transmission layer 30B completely fills each of the plurality of recesses RC. In this case, the thickness of the display body 100 can be suppressed.

FIG. 7 is a cross-sectional view illustrating another modification of the display body illustrated in FIGS. 1 and 2.
In the display body 100 shown in FIG. 7, the light transmission layers 30A and 30B are formed such that the concave portions RC included in the corresponding regions have the same depth, and the refractive indexes of these layers are different from each other. The display has the same configuration as the display described with reference to FIG.

  In the display body 100 shown in FIG. 7, the light transmission layer 30 covers both the partial regions PR1 and PR2 so that the concave portion RC has the same depth in the first partial region PR1 and the second partial region PR2. ing. That is, the light transmission layer 30 includes a first light transmission layer 30A covering the first partial region PR1, and a second light transmission layer covering the second partial region PR2 and having the same thickness as the first light transmission layer 30A. Layer 30B.

  These light transmission layers 30A and 30B have different refractive indexes. Therefore, by providing these light transmission layers 30A and 30B, the optical distance along the optical path in the recess RC can be changed in each of the partial regions PR1 and PR2. Thereby, the effective depth of the plurality of recesses RC in each of the partial regions PR1 and PR2 can be changed.

  Therefore, even when the configuration as shown in FIG. 7 is adopted, different structural colors can be displayed on the display portions DP1 and DP2. Both of these structural colors are typically different from the structural colors resulting from the foundation structure layer 10 alone. Therefore, by adopting such a configuration, a more complicated optical effect can be achieved.

  In the display body 100 shown in FIG. 7, the light transmission layers 30A and 30B have the same thickness. Therefore, the display body 100 has little thickness unevenness in the direction parallel to the main surface. Therefore, when such a configuration is adopted, it is possible to manufacture a display body 100 with particularly high quality.

FIG. 8 is a cross-sectional view illustrating another modification of the display body illustrated in FIGS. 1 and 2.
The display body 100 shown in FIG. 8 has the same configuration as the display body described with reference to FIG. 7 except that both of the light transmission layers 30A and 30B completely fill each of the recesses RC. doing.

  In the display body 100 shown in FIG. 8, the light transmissive layer 30 includes a first light transmissive layer 30A covering the first partial region PR1, and a second light transmissive layer 30B covering the second partial region PR2. . These light transmission layers 30A and 30B completely fill each of the recesses RC in both the partial regions PR1 and PR2.

  These light transmission layers 30A and 30B have different refractive indexes. Therefore, by providing these light transmission layers 30A and 30B, the optical distance along the optical path in the recess RC can be changed in each of the partial regions PR1 and PR2. Thereby, the effective depth of the plurality of recesses RC in each of the partial regions PR1 and PR2 can be changed.

  Therefore, even when the configuration as shown in FIG. 8 is adopted, different structural colors can be displayed on the display portions DP1 and DP2. Both of these structural colors are typically different from the structural colors resulting from the foundation structure layer 10 alone. Therefore, by adopting such a configuration, a more complicated optical effect can be achieved.

  Further, in the display body 100 shown in FIG. 8, the light transmission layers 30A and 30B completely fill the recesses RC. In this case, it is unlikely that the images displayed on the display portions DP1 and DP2 will change significantly due to slight differences or changes in the thicknesses of the light transmission layers 30A and 30B. Therefore, a relatively stable image can be displayed on the display body 100.

  Although the case where the cross-sectional shape of the recessed part RC is V-shaped was demonstrated above, the shape of the recessed part RC is not restricted to this. For example, the cross-sectional shape may be another tapered shape such as a U-shape. Alternatively, the cross-sectional shape may be a rectangular shape.

FIG. 9 is a cross-sectional view showing a modification of the foundation structure layer.
On one main surface of the foundation structure layer 10 shown in FIG. 9, a plurality of recesses RC located between hemispherical protrusions are provided. Each of these recesses RC has a shape that tapers toward the bottom, like the recess described with reference to FIGS. 1 to 8.

  When the concave portion RC having such a tapered shape is employed, a structural color based on light absorption can be displayed on the relief structure as described above. The structural color based on light absorption is more natural than the color based on the diffraction or scattering of light, so the color tone is easy to understand, and a constant structural color can be obtained under a wide range of observation conditions. It is possible to display.

  Further, the concave portion RC having the tapered shape is easier to manufacture using the original plate or the like than the rectangular concave portion RC. Therefore, in this case, the productivity of the foundation structure layer 10 and the display body 100 can be further improved.

FIG. 10 is a cross-sectional view showing another modification of the foundation structure layer.
The basic structure layer 10 shown in FIG. 10 has the same configuration as the basic structure layer described with reference to FIG. 9 except that the cross-sectional shape of the recess RC is rectangular.

  When the cross-sectional shape of the recess RC is rectangular, damage to the surface of the recess RC is relatively difficult to occur. That is, when such a configuration is employed, the durability of the foundation structure layer 10 and the display body 100 can be further improved.

  Although FIG. 1 to FIG. 8 describe the case where the arrangement of the plurality of recesses RC forms a square lattice, the arrangement of the recesses RC is not limited to this.

  For example, the arrangement of the recesses RC may form a rectangular lattice or a triangular lattice. When such a configuration is employed, for example, different structural colors can be displayed depending on the viewing direction. In this way, a more complicated forgery prevention effect can be achieved.

  In addition, when the array of the concave portions RC forms a square lattice, a certain structural color can be displayed under a wider viewing condition than when the array forms a rectangular lattice or a triangular lattice. It becomes possible.

  The concave portions RC may be arranged irregularly. For example, the arrangement of the plurality of recesses RC may have a variation in the distance between the centers. If the plurality of recesses RC are irregularly arranged, a certain structural color can be displayed under a wider range of observation conditions.

  When the concave portions RC are irregularly arranged, the standard deviation of the center-to-center distance is set within a range of, for example, 5% to 30% on the basis of the average center-to-center distance. If this standard deviation is too small, the effect of adopting an irregular arrangement may be insufficient. If the standard deviation is excessively large, it may be relatively difficult to form the recess RC.

  In the above description, the concave portions RC are two-dimensionally arranged. However, the concave portions RC may be arranged one-dimensionally. That is, each of the recesses RC may be a linear or curved groove.

  As described above, the foundation structure layer 10 may further include one or more regions including other recesses that differ from the recesses RC in at least one of shape, depth, average center distance, and arrangement pattern. . At least a part of this region may be covered with the reflection layer 20 and the light transmission layer 30 described above. When such a configuration is employed, a more complicated image can be displayed on the display body 100.

  For example, the region having the other concave portion may be formed separately from the region having the concave portion RC. That is, the region having the other concave portion may be formed using a different original plate from the region having the concave portion RC.

  Alternatively, after forming a plurality of recesses using a single original plate, these regions are deformed by applying heat and / or pressure to a part of the surface where these recesses are formed, or the previous surface It may be formed by applying heat and / or pressure to a part of the surface and the other part in different sizes to deform the recess. By adopting such a method, it is possible to more easily form the plurality of regions.

  The depth of the recess RC provided in the foundation structure layer 10 may be gradually changed along the arrangement of the recess RC. That is, the recesses RC may be formed so that the depth of the recesses RC gradually increases or decreases along the above-described arrangement. Further, the thickness of the light transmission layer 30 may be gradually changed along the above arrangement. That is, the light transmission layer 30 may be formed so that the thickness of the light transmission layer 30 at the position corresponding to the bottom of each recess RC gradually increases or decreases along the above-described arrangement. When at least one of these configurations is employed, a more complicated visual effect such as gradation display can be imparted to the display body 100.

The display body 100 described with reference to FIGS. 1 to 8 may further include a layer other than the base structure layer 10, the reflection layer 20, and the light transmission layer 30.
For example, the display body 100 may further include a protective layer on at least a part of the front surface. In this way, it is possible to further suppress damage to the display surface of the display body 100. Alternatively, the display body 100 may further include an antireflection layer on at least a part of the front surface. In this way, the optical characteristics of the display body 100 can be further improved. These protective layer and / or antireflection layer can be formed by, for example, a known coating method.

  Moreover, in order to improve the adhesiveness between the above layers, corona treatment, flame treatment, plasma treatment, and the like may be performed. Alternatively, an adhesive anchor layer may be interposed between these layers.

  Alternatively, at least one of the above layers may be colored. For example, the basic structure layer 10 may be a colored layer. In this way, more complex optical effects can be achieved. Moreover, the designability of the display body 100 improves.

  In addition, the display body 100 may have the structure which combined 2 or more of the various modifications illustrated above. In this way, for example, a more complex image can be displayed on the display body 100, and the forgery prevention effect can be further improved.

(Display by pixel group)
The image displayed on the display body 100 may be composed of a plurality of pixels arranged two-dimensionally.
FIG. 11 is a plan view schematically showing a display body according to another aspect of the present invention.

  The display body 100 shown in FIG. 11 has the same configuration as that described with reference to FIGS. 1 to 10 except that it includes a plurality of pixels PE.

  These pixels PE are arranged in the X and Y directions intersecting each other. That is, these pixels PE are adjacent to each other along the X and Y directions. These pixels PE may be adjacent to each other or may be separated from each other. FIG. 11 illustrates a case where these pixels PE are adjacent to each other along the X and Y directions as an example. Here, as an example, it is assumed that the X and Y directions are orthogonal.

  The pixels PE typically have the same shape and dimensions. The pixels PE have small dimensions and typically cannot be distinguished from each other when viewed with the naked eye. For example, the dimension of each pixel PE in the X direction is about 50 μm.

  In at least two of these pixels PE, for example, the thickness, refractive index, total light transmittance with respect to light in the visible range, and the area of the portion where the light transmissive layer 30 is formed with respect to the area of the pixel PE are set. Make them different from each other. Thus, different structural colors can be displayed on these pixels PE when illuminated with white light. In addition, when such a configuration is adopted, a desired pattern can be recorded on the display body 100 more precisely. In addition, this makes it easier to display a multicolor image on the display body 100.

(Usage of display body)
The display body 100 described above may be used as, for example, an adhesive sticker, a transfer foil, or a part of a thread. Or you may use this display body 100 as a part of tear tape.

  FIG. 12 is a cross-sectional view schematically showing an adhesive sticker according to one embodiment of the present invention. An adhesive sticker 200 shown in FIG. 12 includes the display body 100 shown in FIGS. 1 and 2 and an adhesive layer 40 provided on the back surface of the display body 100.

  The adhesive layer 40 is provided on the back surface of the foundation structure layer 10. The adhesive layer 40 faces the light transmission layer 30 with the foundation structure layer 10 interposed therebetween.

  As a material for the pressure-sensitive adhesive layer 40, a pressure-sensitive adhesive is typically used. Examples of the material for the adhesive layer 40 include vinyl chloride-vinyl acetate copolymer, polyester polyamide, and acrylic, butyl rubber, natural rubber, silicon, or polyisobutyl. The pressure-sensitive adhesive layer may further contain an aggregating component, a modifying component, and an additive as necessary. Examples of the aggregating component include alkyl methacrylate, vinyl ester, acrylonitrile, styrene, and vinyl monomer. Examples of the modifying component include unsaturated carboxylic acid, hydroxy group-containing polymer, and acrylonitrile. Examples of the additive include a polymerization initiator, a plasticizer, a curing agent, a curing accelerator, and an antioxidant. Alternatively, as the pressure-sensitive adhesive layer 40, an adhesive whose both surfaces are constituted by film separators may be used.

  The adhesive layer 40 is formed by, for example, a printing method such as a gravure printing method, an offset printing method, or a screen printing method, or a coating method such as a bar coating method, a gravure method, or a roll coating method. The thickness of the adhesive layer 40 is, for example, in the range of 1 μm to 10 μm.

  This adhesive sticker 200 is affixed, for example, to an article to be verified or to another article such as a tag substrate to be attached to such article. Thereby, the forgery prevention effect can be provided to the said article | item. The adhesive sticker 200 is attached by, for example, a roll laminating method.

  The adhesive sticker 200 shown in FIG. 12 may be manufactured by providing the adhesive layer 40 on the back surface of the display body 100, and the adhesive layer on the back surface of the blank medium corresponding to a portion other than the light transmission layer 30 in the display body 100. After providing 40, the light transmitting layer 30 may be formed.

  FIG. 13 is a cross-sectional view schematically illustrating a transfer foil according to an aspect of the present invention. A transfer foil 300 shown in FIG. 13 includes the display body 100 shown in FIGS. 1 and 2 and a support layer 50 that supports the display body 100 in a peelable manner. In FIG. 13, as an example, a case where a peeling layer 52 is provided between the front surface of the display body 100 and the support layer 50 and an adhesive layer 54 is provided on the back surface of the display body 100 is illustrated. Yes.

  The support layer 50 is, for example, a film or sheet made of a resin. As a material of the support layer 50, for example, polyethylene terephthalate resin, polyethylene naphthalate resin, polyimide resin, polyethylene resin, polypropylene resin, or vinyl chloride resin is used.

  The peeling layer 52 plays a role of facilitating peeling of the support layer 50 when transferring the transfer foil 300 to the transfer target. As a material of the release layer 52, for example, a resin is used. The release layer 92 may further contain additives such as paraffin wax, carnauba wax, polyethylene wax, and silicone. Note that the thickness of the release layer 52 is, for example, in the range of 0.5 μm to 5 μm.

  As a material for the adhesive layer 54, for example, an adhesive such as a reactive curable adhesive, a solvent-evaporating adhesive, a hot melt adhesive, an electron beam curable adhesive, and a heat sensitive adhesive is used.

  As the reaction curable adhesive, for example, polyurethane resins such as polyester urethane, polyether urethane, and acrylic urethane, or epoxy resins are used.

  Solvent volatilization type adhesives include, for example, aqueous emulsion adhesives including vinyl acetate resin, acrylate copolymer resin, ethylene-vinyl acetate copolymer resin, ionomer resin and urethane resin, natural rubber, styrene-butadiene A latex adhesive containing a copolymer resin and an acrylonitrile-butadiene copolymer resin is used.

  As the hot melt adhesive, for example, an adhesive containing ethylene-vinyl acetate copolymer resin, ethylene-ethyl acrylate copolymer resin, polyester resin, polycarbonate resin, polyvinyl ether resin, polyurethane resin, or the like as a base resin is used.

  As the electron beam curable adhesive, for example, an adhesive mainly containing an oligomer having one or more vinyl functional groups such as acryloyl group, allyl group and vinyl group is used. For example, as an electron beam curable adhesive, a mixture of polyester acrylate, polyester methacrylate, epoxy acrylate, epoxy methacrylate, urethane acrylate, urethane methacrylate, polyether acrylate or polyether methacrylate and an adhesion-imparting agent can be used. As the adhesion-imparting agent, for example, an acrylate containing phosphorus or a derivative thereof, or an acrylate containing a carboxy group or a derivative thereof is used.

  As the heat-sensitive adhesive, for example, polyester resin, acrylic resin, vinyl chloride resin, polyamide resin, polyvinyl acetate resin, rubber resin, ethylene-vinyl acetate copolymer resin, or vinyl chloride-vinyl acetate copolymer resin is used.

  The adhesive layer 54 is obtained by, for example, applying the above-described resin on the back surface of the display body 100 using a coater such as a gravure coater, a micro gravure coater, and a roll coater.

  The transfer foil 300 is transferred to a transfer target by, for example, a roll transfer machine or a hot stamp. At this time, peeling occurs in the peeling layer 52, and the display body 100 is attached to the transfer object via the adhesive layer 54.

  In addition, the transfer foil 300 shown in FIG. 13 is manufactured as follows, for example. That is, first, the display body 100 is formed on the first support. In addition, you may manufacture this structure by providing the light transmissive layer 30, after forming the blank medium which consists of the base structure layer 10 and the reflection layer 20 on a 1st support body. Next, the laminated body of the first support body and the display body 100 is transferred onto the second support body as the support body layer 50 via the brittle layer 52, and at the same time, the first support body is peeled off. Subsequently, an adhesive layer 54 is formed on the back side of the obtained configuration. The transfer foil 300 is obtained as described above.

  As described above, the display body 100 has an excellent anti-counterfeit effect. Therefore, when the display body 100 is supported by an article, it is difficult to counterfeit the genuine article with the display body. In addition, since the display body 100 has the above-described visual effect, it is easy to determine an article whose authenticity is unknown between genuine and non-authentic.

  FIG. 14 is a plan view schematically showing an example of an article with a display body. FIG. 14 illustrates a card 400 as an example of an article with a display body. The card 400 is an ID card and includes a card body 401.

  The card body 401 includes a base material 402. The base material 402 is made of plastic, for example. A printed layer 403 is formed on the substrate 402. The display body 100 described above is fixed to the surface of the substrate 402 on which the printing layer 403 is formed. The display body 100 is fixed to the base material 402, for example, by being attached via an adhesive layer or an adhesive layer.

  Since the printed matter 400 includes the display body 100, it is difficult to forge it. In addition, since the printed matter 400 includes the display body 100, it is easy to discriminate between an authentic product and a non-authentic product for an article whose authenticity is unknown.

  The display body 100 may be supported on a base material made of paper or paper. In this way, for example, securities, paper, passports and the like having a high anti-counterfeiting effect can be manufactured.

  The article with a display body may not be a printed matter. That is, the display body 100 may be supported on an article that does not include a printed layer.

  In the above, instead of supporting the display body 100 itself on the article, an intermediate product that includes the basic structure layer 10 and does not include the light transmission layer 30 may be supported on the article. Then, the display body 100 may be manufactured by forming the light transmission layer 30 on the intermediate product. Such an embodiment is particularly useful for an article that requires on-demand image recording, such as a passport.

  The display body 100 may be used as a pigment component of the anti-counterfeit ink. In this case, the display body 100 is used after being appropriately pulverized.

  The display body 100 may be used for purposes other than forgery prevention. For example, the display body 100 can be used as a toy, a learning material, or a decoration.

(Example 1)
The display body 100 was manufactured as follows.
First, an ink composition (ultraviolet curable resin) having the following composition was prepared.

-Urethane (meth) acrylate: 50.0 parts by mass-Methyl ethyl ketone: 30.0 parts by mass-Ethyl acetate: 20.0 parts by mass-Photoinitiator: 1.5 parts by mass As the above urethane (meth) acrylate, UN-952 manufactured by Negami Kogyo Co., Ltd. was used. In addition, this urethane (meth) acrylate was polyfunctional and the weight average molecular weight was 6500. As a photoinitiator, Irgacure 184 manufactured by Ciba Specialty was used.

  Next, on the base material which consists of a transparent PET film whose thickness is 23 micrometers, said composition was apply | coated by the gravure printing method so that the film thickness after drying might be set to 1 micrometer.

Then, the cylindrical original plate provided with the fine concavo-convex structure corresponding to the shape of the several recessed part RC mentioned later was pressed against the application surface, and the embossing was performed. This embossing was performed at a press pressure of 2 kgf / cm ² , a press temperature of 80 ° C., and a press speed of 10 m / min. Simultaneously with this processing, ultraviolet exposure was performed from the side of the substrate made of a transparent PET film with an exposure amount of 300 mJ / cm ² using a high-pressure mercury lamp. Thereby, said composition was hardened and the basic structure layer 10 was obtained.

  This foundation structure layer 10 was provided with a convex portion on one main surface that was closely packed with a hemisphere having a diameter of 400 nm in a triangular lattice shape. That is, this foundation structure layer 10 was provided with a plurality of recesses RC corresponding to the space between these protrusions on one main surface. The average distance between the centers of the plurality of recesses RC was 400 nm, and the depth was 200 nm.

  Subsequently, Al was vacuum-deposited over the whole main surface in which the recessed part RC of the basic structure layer 10 was provided so that the thickness on a smooth surface might be set to 50 nm. Thus, the reflective layer 20 made of Al was formed. As described above, an intermediate product composed of the base structure layer 10 and the reflective layer 20 was obtained.

  Thereafter, a copolymer resin (vinyl chloride resin) of vinyl chloride and vinyl acetate was applied on a part of the reflective layer 20 by an ink jet method and dried. In this way, a light transmission layer 30 was obtained. The light transmission layer 30 was colorless and transparent. Moreover, the light transmission layer 30 was formed so that the thickness at a position corresponding to the bottom of the plurality of recesses RC would be 100 nm. The display body 100 was obtained as described above.

(Example 2)
An intermediate product and a display body 100 were obtained in the same manner as in Example 1 except that the thickness of the light transmission layer 30 at the position corresponding to the bottom of the plurality of recesses RC was 240 nm instead of 100 nm.

(Example 3)
A monolayer particle film was formed on a substrate using monodispersed silica nanoparticles having an average particle diameter of 400 nm measured by a dynamic scattering method. Thus, the foundation structure layer 10 provided with the some recessed part RC was obtained. Thereafter, an intermediate product and a display body 100 were obtained in the same manner as in Example 1 except that this basic structure layer 10 was used.

(Example 4)
A display body 100 was obtained in the same manner as in Example 1 except that the light transmission layer 30 was colored with an isoindolinone-based yellow pigment. In this display body 100, the total light transmittance with respect to light in the visible range of the light transmission layer 30 was 80%.

(Example 5)
A display body 100 was obtained in the same manner as in Example 4 except that the content of the isoindolinone yellow pigment in the light transmission layer 30 was increased. In this display body 100, the total light transmittance of the light transmission layer 30 with respect to light in the visible range was 30%.

(Evaluation)
The display bodies 100 according to Examples 1 to 5 were observed from a plurality of observation angles under a multicolor light source. More specifically, these display bodies 100 were observed under two or more fluorescent lamps in the room from two directions of 0 ° and 60 ° with respect to the normal direction of the display surface. And the structural color which each of 1st display part DP1 and 2nd display part DP2 displays evaluated with the naked eye. The results are shown in Table 1 below.

  As is clear from Table 1, the display body 100 according to Examples 1 to 5 displayed different structural colors on the display units DP1 and DP2 at any observation angle. Moreover, in the display body 100 according to Examples 1 to 4, the structural color changed according to the observation angle in the display unit DP1.

  DESCRIPTION OF SYMBOLS 10 ... Base structure layer, 20 ... Reflection layer, 30 ... Light transmission layer, 30A ... 1st light transmission layer, 30B ... 2nd light transmission layer, 40 ... Adhesion layer, 50 ... Support layer, 52 ... Release layer, 54 DESCRIPTION OF SYMBOLS ... Adhesive layer, 100 ... Display body, 200 ... Adhesive sticker, 300 ... Transfer foil, 400 ... Card, 401 ... Card main body, 402 ... Base material, 403 ... Print layer, DP1 ... Display part, DP2 ... Display part, DP3 ... Display unit, DP4 ... display unit, PE ... pixel, PR1 ... partial region, PR2 ... partial region, RC ... concave portion.

Claims (10)

A basic structure layer including a relief structure composed of a plurality of recesses arranged uniformly on one main surface, wherein the plurality of recesses are provided so that the relief structure displays a structural color when illuminated with white light When,
A light transmissive layer covering at least a part of a region of the main surface provided with the plurality of recesses, the light transmissive layer,
The first and second portions so that the recesses have different depths in the first and second partial regions of the region, or the recesses are completely embedded only in one of the first and second partial regions. A first portion corresponding to the first partial region and a second portion corresponding to the second partial region of the relief structure when covering at least one of the regions and illuminated with the white light; Display a different structural color, or
A first light transmission layer covering a first partial region of the region, and a second light transmission layer having a refractive index different from that of the first light transmission layer and covering a second partial region of the region, A display body that displays different structural colors on a first portion corresponding to the first partial region and a second portion corresponding to the second partial region in the relief structure when illuminated with white light.   The display body according to claim 1, further comprising a reflective layer interposed between the base structure layer and the light transmission layer.   In at least one of the first and second partial regions, the thickness of the light transmission layer at a position corresponding to the bottom of the plurality of recesses is compared with the depth of the plurality of recesses when the light transmission layer is not present. The display body according to claim 1 or 2, wherein the display body is smaller.   In at least one of the first and second partial regions, the thickness of the light transmission layer at a position corresponding to the bottom of the plurality of recesses is such that the thickness of the light transmission layer at a position between the plurality of recesses adjacent to each other. The display body according to claim 1, wherein the display body is larger than the thickness.   The display body according to claim 1, wherein the light transmission layer has a total light transmittance of 50% or more with respect to light in a visible range.   The display body according to claim 1, wherein the light transmission layer is colorless.   The display body according to claim 1, wherein an average center distance between the plurality of concave portions is in a range of 180 nm to 830 nm.   The display body according to claim 1, wherein the plurality of recesses are regularly arranged. The display body according to any one of claims 1 to 8, wherein each of the plurality of concave portions is tapered toward a bottom portion thereof. A basic structure layer including a relief structure composed of a plurality of recesses arranged uniformly on one main surface, wherein the plurality of recesses are provided so that the relief structure displays a structural color when illuminated with white light Preparing and
The recesses are completely embedded only in one of the first and second partial regions so that the recesses have different depths in the first and second partial regions provided with the plurality of recesses in the main surface. As described above, at least one of the first and second partial regions is covered with a light transmissive material, or the first and second partial regions have different refractive indexes, respectively. A structural color different between a first portion corresponding to the first partial region and a second portion corresponding to the second partial region of the relief structure when coated with a material and illuminated with the white light Forming a light-transmitting layer for displaying the display.

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