JP6187611B2 - Colored anti-counterfeit structure and colored anti-counterfeit medium - Google Patents

Description

  The present invention relates to an anti-counterfeit structure and a colored anti-counterfeit medium having high anti-counterfeit and anti-counterfeit effects.

  The forgery prevention structure is used to prevent forgery of securities, brand products, certificates, personal authentication media, and the like, and has a function of proving that it is an authentic product.

  In recent years, since special optical effects can be distinguished at a glance, anti-counterfeit structures using optical elements such as diffraction gratings and holograms have been used for various articles. Many optical elements include fine structures such as diffraction gratings, holograms, and lens arrays. These microstructures are difficult to analyze. In addition, since an optical element including a fine structure is manufactured using an electron beam drawing apparatus or the like, an excellent anti-counterfeit effect can be exhibited.

  However, holograms having a silver metallic luster are on the market for use as packages and games, and security is becoming low. In order to cope with this situation, for example, Patent Document 1 proposes a hologram having a partially reflecting layer as a hologram having a higher anti-counterfeit effect. It is considered difficult to forge a hologram having a reflective layer with a fine pattern.

  On the other hand, a hologram having a metallic luster having a bright color tone other than silver has also been proposed. For example, Patent Document 1 proposes a hologram structure that provides a desired color tone and is excellent in design and / or security. By using this method, it is possible to give some color tone. However, the reflectivity of the high-brightness ink layer is lower than the reflectivity of the aluminum deposited film and tends to scatter. For this reason, there exists a fault that the colored metallic luster, for example, the metallic luster of a vivid color tone like gold | metal | money and copper, cannot be obtained.

  Further, in the method of Patent Document 1, it is difficult to provide a reflective layer partially colored on the hologram. This is because it is difficult to overprint the reflective layer having the same pattern with high positional accuracy with respect to the colored layer after pattern printing of the colored layer.

  Further, a method of forming gold or copper as a colorful reflective layer by a vacuum deposition method or a sputtering method and patterning by etching can be considered. However, providing a noble metal reflective layer having a fine pattern by etching is expensive and low in productivity.

JP 2008-162260 A

  The subject of this invention is providing the forgery prevention structure which is excellent in the designability and / or security property.

According to the first aspect of the present invention, the relief forming layer, the first reflective layer, the functional thin film layer, the second reflective layer and the protective layer are laminated in this order,
The first reflective layer, the functional thin film layer, and the second reflective layer produce an interference color by a three-layer interference film,
The functional thin film layer is an intermediate layer of a three-layer interference film,
One side of the relief forming layer has a relief structure having an effect of diffracting, scattering, absorbing, and polarizing and separating at least a part of a wavelength region of visible light,
The first reflective layer and the functional thin film layer are provided on the entire surface along the unevenness of the relief structure,
The second reflective layer is provided in an arbitrary region covering a part of the unevenness of the relief structure,
The protective layer is provided so as to cover only the region of the second reflective layer, and the three layers of the first reflective layer, the functional thin film layer, and the second reflective layer interfere with at least a partial region of visible light. An anti-counterfeit structure is provided.

According to the second aspect of the present invention, there is provided a forgery prevention structure in which at least a relief forming layer, a first reflective layer, a functional thin film layer, a second reflective layer and a protective layer are laminated in this order,
One side of the relief forming layer has a relief structure having a first relief and a second relief, which has an effect of diffracting, scattering, absorbing, and polarizing and separating at least a part of a wavelength region of visible light,
The first relief surface has a small uneven surface area compared to the second relief surface,
The first reflective layer and the functional thin film layer are provided on the entire surface along the unevenness of the relief structure,
The second reflective layer and the protective layer are provided so as to cover only the surface of the functional thin film layer of the first relief,
An anti-counterfeit structure is provided in which the three layers of the first reflective layer, the functional thin film layer, and the second reflective layer interfere with at least a partial region of visible light.

According to a third aspect of the present invention, in the first or second aspect, the first reflective layer comprises tantalum oxide, niobium oxide, titanium oxide, indium tin oxide, zirconium oxide, cerium oxide, and The anti-counterfeit structure according to the first aspect or the second aspect of the present invention is characterized by including at least one selected from the group of hafnium oxides.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the first reflective layer is formed of a high-intensity transparent reflective paint made of highly refractive fine particles. A prevention structure is provided.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the relief structure includes at least one of a diffractive structure, a hologram, a condenser lens array, a diffusing lens array, and a scattering structure. An anti-counterfeit structure is provided that is partially coplanar.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the anti-counterfeit structure is laminated on at least a support base material, the relief forming layer on the support base material, There is provided a forgery prevention structure having a sticker structure in which a first reflective layer, a functional thin film layer, a second reflective layer, a protective layer, and an adhesive layer are laminated in this order.

  According to a seventh aspect of the present invention, in any one of the first to fifth aspects, at least a support base material is provided, and a relief forming layer, a first reflection layer, and a functional thin film layer are provided on the support base material. The anti-counterfeit structure is characterized in that the second reflective layer, the protective layer, and the adhesive layer are laminated in this order, and the laminate has a transfer foil configuration that can be peeled off from the substrate. .

  In the seventh and eighth side surfaces, a peeling protective layer may be provided between the support base and the relief forming layer as necessary. The peeling protective layer is a layer for peeling off from the supporting substrate smoothly and stably, and a material having good releasability with respect to the supporting substrate may be selected.

  According to the 8th side surface of this invention, the forgery prevention medium which stuck the any one forgery prevention structure body of the said 1st thru | or 7th side surface is provided.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the forgery prevention structure body which is excellent in design property and / or security property.

It is sectional drawing which shows the forgery prevention structure which concerns on 1st Embodiment. It is sectional drawing which shows the manufacturing process of the forgery prevention structure which concerns on 1st Embodiment. It is sectional drawing which shows another aspect of the forgery prevention structure which concerns on 1st Embodiment. It is sectional drawing which shows another aspect of the forgery prevention structure which concerns on 1st Embodiment. It is sectional drawing which shows the forgery prevention structure which concerns on 2nd Embodiment. It is sectional drawing which shows 1 process at the time of manufacture of the forgery prevention structure which concerns on 2nd Embodiment. It is sectional drawing which shows 1 process at the time of manufacture of the forgery prevention structure of the comparative example 1.

(First embodiment)
Hereinafter, a forgery prevention structure according to a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of the forgery prevention structure according to the first embodiment.

  In the anti-counterfeit structure 1, a relief forming layer 2, a first reflective layer 3, a functional thin film layer 4, a second reflective layer 5 and a protective layer 6 are laminated in this order. One side of the relief forming layer 2 has a relief structure 7 having a fine uneven pattern. The relief structure 7 has an effect of diffracting, scattering, absorbing, and polarization-separating at least part of the wavelength region of visible light. The first reflective layer 3 and the functional thin film layer 4 are provided on the entire surface along the unevenness of the relief structure 7. The second reflective layer 5 is provided so as to cover a part of the unevenness of the relief structure 7 in an arbitrary region (first region) 8 of the relief structure 7. The protective layer 6 is provided so as to cover only the second reflective layer 5.

  The first region 8 is a region where the first reflective layer 3, the functional thin film layer 4, the second reflective layer 5 and the protective layer 6 are laminated in this order on the uneven surface of the relief forming layer 2. A colored reflective layer is obtained in which at least a partial region of visible light interferes with the three layers including the functional thin film layer 4 and the second reflective layer 5. The three layers can also obtain a reflective layer whose color tone changes depending on the observation angle, and a relief structure having a colorful reflective layer can be designed.

  The colored reflective layer exists only in the first region 8 portion, and only the patterned second reflective layer 5 is colored. In the first region 8, the patterned second reflective layer 5 itself is colored. As a result, since the second reflective layer 5 itself is a colored pattern, the colored ink is patterned and printed, and the reflective layer is formed so as to match the colored pattern. It is possible to avoid misalignment.

  The second region 9 is a region composed of the first reflective layer 3 and the functional thin film layer 4 without the second reflective layer 5 and the protective layer 6. For this reason, also in the second region 9, it is possible to obtain an achromatic optical effect due to the relief structure.

  A typical theory of the three-layer interference film is described in Japanese Patent Application Laid-Open No. 2010-175812. This patent publication describes a multilayer interference film having three or more layers. In contrast, the anti-counterfeit structure according to the first embodiment is limited to a three-layer interference film. That is, as the total number of reflective layers is increased, there is an advantage that reflection of interference colors can be increased. However, in this case, there is a problem that not only the first region but also the second region where the uppermost reflective layer does not exist is colored due to interference because there are at least two reflective layers. That is, in a multilayer film of five or more layers, a similar interference color occurs in a portion where the uppermost high refractive reflective layer is present (first region) and a portion where it is absent (second region). For this reason, when a multilayer film of five or more layers is applied to the forgery prevention structure according to the first embodiment, the first region 8 and the second region 9 have similar color tendencies.

  The anti-counterfeit structure according to the first embodiment is limited to a three-layer interference film, whereby a portion where the second reflective layer 5 is present (first region 8) is colored by interference, and a portion where the second reflective layer 5 is not present. In the (second region 9), there is no interference and an achromatic color is obtained, and a sufficient tone difference can be developed between the first region 8 and the second region 9.

  Accordingly, the anti-counterfeit structure 1 according to the first embodiment provides a precise and complicated optical effect due to the colored reflection relief structure in the first region 8 and the achromatic reflection relief in the second region 9, so that high forgery is achieved. Preventive effect can be expressed.

  Next, the manufacturing method of the forgery prevention structure according to the first embodiment will be described with reference to FIGS.

1) 1st process As shown to (a) of FIG. 2, the relief forming layer 2 is formed in the whole surface on the support base material 11. FIG. The relief forming layer 2 can be formed on the support substrate 11 by coating, for example, wet coating. The relief forming layer may be the support substrate itself.

  Next, a relief original plate made of a metal or resin having an uneven shape is prepared, and the uneven shape of this original plate is transferred onto the surface of the relief forming layer 2 to form a relief structure 7 having an uneven surface in the relief forming layer 2 ( FIG. 2 (a) is shown.

  The shape transfer method may be a known method such as a press method, a casting method, or a photopolymer method, which will be described later, or a hybrid method combining these methods.

(Second step)
As shown in FIG. 2B, the first reflective layer 3, the functional thin film layer 4, and the second reflective layer thin film layer 12 are formed in this order on the surface of the relief structure 7 of the relief forming layer 2.

  The first reflective layer 3 and the functional thin film layer 4 can be formed by known wet coating or dry coating. The thin film layer 12 for the second reflective layer is preferably formed by dry coating.

(Third step)
A protective film 6 that functions as an etching mask is formed on the second reflective layer thin film layer 12. Subsequently, the second reflective layer 5 is formed by selectively removing the second reflective layer thin film layer 12 with an etching treatment agent using the protective film 6 as a mask. That is, the second reflective layer thin film layer 12 is left in the region below the protective film 6 (first region 8) to form the second reflective film 5, and the second reflective layer thin film in other regions (second region 9). Layer 12 is removed. Here, it is necessary not to remove the first reflective layer 3 by etching.

  Specifically, after the second reflective layer thin film layer 12 is formed on the entire surface of the functional thin film layer 4, the protective layer 6 is formed on the second reflective layer thin film layer 12 by a known wet printing method. Then, the patterned second reflective layer 5 is formed by selectively etching the second reflective thin film layer 12 using the protective layer 6 as an etching mask.

  The forgery prevention structure according to the first embodiment is manufactured through the first to third steps described above, but is not limited thereto. Next, the material of each layer constituting the forgery prevention structure according to the first embodiment, necessary characteristics, and a detailed manufacturing method will be described in more detail.

(Supporting substrate)
The support substrate used in the above-described production method is preferably a film substrate. As the film base material, it is desirable to use a material that is hardly deformed or deteriorated by heat, pressure, or electromagnetic waves applied at the time of forming a fine uneven pattern (relief structure). As the film substrate, for example, a plastic film such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PP (polypropylene) can be used. If necessary, paper, synthetic paper, plastic multilayer paper, resin-impregnated paper, or the like may be used as the supporting substrate.

(Relief forming layer)
The relief forming layer preferably replicates a relief structure having a fine uneven pattern on one side continuously and in large quantities. Representative techniques include “pressing method” described in Japanese Patent No. 4194073, “casting method” described in Utility Model Registration No. 2524092, “photopolymer method” described in Japanese Patent No. 4088884, and the like. Shape transfer is adopted.

  Among them, the “photopolymer method” (2P method, photosensitive resin method) is a radiation that casts a radiation curable resin between a relief mold (recovery mold for fine uneven patterns) and a flat substrate (plastic film, etc.). Then, the cured film is peeled off from the replica mold together with the substrate. By this method, a relief structure having a high-definition fine concavo-convex pattern can be obtained. The relief structure obtained by such a method has higher molding accuracy of the fine concavo-convex pattern and is excellent in heat resistance and chemical resistance than the “press method” and “cast method” using a thermoplastic resin.

  In addition, as a method for producing a relief forming layer having a new relief structure, there are a method of molding using a photocurable resin that is solid or highly viscous at room temperature, and a method of adding a release material.

  Materials used for the relief forming layer include, for example, thermoplastic resins such as acrylic resins, epoxy resins, cellulose resins, and vinyl resins; acrylic polyols and polyester polyols having reactive hydroxyl groups, and polyisocyanates as cross-linking agents. Addition and cross-linked urethane resin; a thermosetting resin such as a melamine resin, an epoxy resin, or a phenol resin can be used alone or in combination. Any material other than those described above can be used as long as the material can form a fine uneven pattern.

As the material of the relief forming layer applied to the photopolymer method, for example, a monomer, oligomer, polymer or the like having an ethylenically unsaturated bond or an ethylenically unsaturated group can be used.
As the monomer, for example, 1,6-hexanediol, neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, or the like can be used. Examples of the oligomer include epoxy acrylate, urethane acrylate, and polyester acrylate. As the polymer, for example, urethane-modified acrylic resin and epoxy-modified acrylic resin can be used.

  As a material for the relief forming layer utilizing photocationic polymerization, for example, a monomer, oligomer, polymer, oxetane skeleton-containing compound or vinyl ether having an epoxy group can be used. When the ionizing radiation curable resin is cured by light such as ultraviolet rays, a photopolymerization initiator can be added. Depending on the resin, a radical photopolymerization initiator, a cationic photopolymerization initiator, or a combination thereof (hybrid type) can be selected.

  In addition, it is possible to use a mixture of monomers, oligomers, polymers, etc. having an ethylenically unsaturated bond or an ethylenically unsaturated group, preliminarily provide a reactive group, isocyanate compound, silane coupling agent, organic titanate crosslinking material, Crosslinking each other with an organic zirconium crosslinking agent, organic aluminate, etc., providing a reactive group in advance, isocyanate resin, silane coupling agent, organic titanate crosslinking material, organic zirconium crosslinking agent, organic aluminate, etc., and other resins It is also possible to crosslink with the skeleton. According to such a method, in the use of a polymer having an ethylenically unsaturated bond or an ethylenically unsaturated group, a polymer that exists in a solid state at room temperature and has good moldability due to less tack and has little original plate contamination. It is also possible to obtain.

  Examples of the radical photopolymerization 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, and 1-hydroxycyclohexylphenyl. Phenyl ketone compounds such as ketone, α-aminoacetophenone, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, benzyldimethyl ketal, thioxanthone, acylphosphine oxide, Michler's ketone, etc. can be used. .

  As the photocationic polymerization initiator when using the photocationically polymerizable compound, for example, an aromatic diazonium salt, an aromatic iodonium salt, an aromatic sulfonium salt, an aromatic phosphonium salt, a mixed ligand metal salt, or the like can be used. . In the case of a so-called hybrid type material using both radical photopolymerization and cationic photopolymerization, respective polymerization initiators can be mixed and used. In addition, an aromatic iodonium salt, an aromatic sulfonium salt or the like having a function of initiating polymerization of both by one kind of initiator can be used.

  In a resin composition containing a radiation curable resin and a photopolymerization initiator, the blending ratio of the photopolymerization initiator may be appropriately selected depending on the material, but is generally 0.1 to 15% by mass. The resin composition may further use a sensitizing dye in combination with a photopolymerization initiator. Resin compositions include dyes, pigments, various additives as necessary (polymerization inhibitors, leveling agents, antifoaming agents, sagging inhibitors, adhesion improvers, coating surface modifiers, plasticizers, nitrogen-containing compounds, etc.) In addition, a cross-linking agent (for example, an epoxy resin) may be included. Further, a non-reactive resin (including the above-described thermoplastic resin and thermosetting resin) may be added to improve moldability.

  In the manufacturing method described above, the material of the relief forming layer should be selected considering that it has a certain degree of fluidity that can be molded and that the molded coating film has the desired heat resistance and chemical resistance. Good.

  A coating method may be used in the step of forming the relief forming layer. In that case, the material for the relief forming layer may be coated on the support substrate. In particular, wet coating can be formed at low cost. Alternatively, the thickness of the relief forming layer may be adjusted by applying a solution diluted with a solvent and drying.

  The thickness of the relief forming layer is preferably in the range of 0.1 to 10 μm, for example. Although it depends on the method for producing the relief forming layer described above, if it is too thick, the resin protrudes due to pressurization during processing for transferring the relief structure, which causes wrinkles. On the other hand, if the thickness is too thin, the fluidity at the time of transfer of the relief structure becomes poor, and there is a possibility that sufficient molding cannot be performed. Moreover, although the transferability of a fine uneven | corrugated pattern changes with the shapes, it is desirable that the thickness of a relief formation layer is 1 to 10 times the desired uneven | corrugated depth, More preferably, it is 3 to 5 times.

  After the relief forming layer is brought into contact with a relief original plate having a desired relief structure, the shape of the relief original plate is transferred to one side of the relief forming layer using heat, pressure, and electromagnetic waves if necessary. The relief forming layer may form a relief structure on both sides, that is, on the front and back sides as well as on one side.

  As a method for producing the relief original plate to be used, a known method may be used, and continuous forming is possible if it is a roll-shaped original plate.

(First reflective layer)
The first reflective layer has a function of reflecting electromagnetic waves. When reflecting the light which permeate | transmitted the support base material and the relief forming layer which has a relief structure with a fine uneven | corrugated pattern, the high refractive index material higher than the refractive index of a support base material or a relief forming layer is used. In this case, the difference in refractive index between the first reflective layer and the relief forming layer is preferably 0.2 or more. By setting the difference in refractive index to 0.2 or more, refraction and reflection occur at the interface between the relief forming layer and the first reflective layer. In addition, the 1st reflection layer which covers a relief structure can also emphasize the optical effect by the fine concavo-convex structure.

  As the material for the first reflective layer, for example, a single metal material such as Al, Sn, Cr, Ni, Cu, Au, or Ag, or a compound thereof can be used.

  The first reflective layer preferably has a transmittance of 40% or less. Since an interference color is generated by the three-layer interference film of the first reflection layer, the functional thin film layer, and the second reflection layer, the first reflection layer has transparency, and the relief forming layer and the functional thin film layer It is preferable to have a refractive index difference of 0.2 or more and to cause reflection at both interfaces.

  The first reflective layer having such transparency can be realized by forming it from a thin film of the above-mentioned metal material or a compound.

Examples of materials that can be used as the first reflective layer having transparency other than the metal and the compound are listed below. The numerical value in parentheses indicates the refractive index n. Ceramics are, 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 (5.0), WO ₃ (5.0), SiO (5.0), 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 (5.0), MgO (1. 0), SiO ₂ (1.45), Si ₂ O ₂ (10), MgF ₂ (4.0), CeF ₃ (1.0), CaF ₂ (1.3 to 1.4), AlF ₃ ( 1.0), Al ₂ O ₃ (1.0), GaO (2.0), etc. can be used. As the organic polymer, for example, polyethylene (1.51), polypropylene (1.49), polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49), polystyrene (1.60) and the like can be used.

  The first reflective layer needs to be resistant to the etching treatment agent used when patterning the second reflective layer in the manufacturing method described above. For example, since the reflectance of the first reflective layer in the second region does not change due to dissolution, corrosion, alteration, peeling, or the like with respect to the etching treatment agent, it is necessary to be stable, and thus the material is appropriately selected from the above materials. That's fine. In some cases, a plurality of materials may be used.

  In addition, you may strengthen the tolerance with respect to the etching processing agent of the 1st reflective layer in a 2nd area | region by the functional thin film layer arrange | positioned so that a 1st reflective layer may be covered. That is, even if the first reflective layer has low resistance to the etching treatment agent, the first reflective layer is protected from the etching treatment agent by forming a multilayer with the functional thin film layer, whereby the first reflective layer in the second region is protected. Decrease in reflection function can be prevented.

  The first reflective layer preferably employs a dry coating method, such as a vacuum deposition method, a sputtering method, or a CVD method, in order to form a thin film with a uniform thickness on the fine uneven surface of the relief forming layer in the manufacturing method described above. .

  The first reflective layer is a high-brightness light-reflecting ink obtained by dispersing the metal, ceramics, or organic polymer fine powder, sol, or metal nanoparticles in an organic polymer resin, or organic polymer or organic polymer fine particles. Can also be used. The first reflective layer can be formed by a known printing method such as a gravure printing method, a flexographic printing method, or a screen printing method. When the first reflective layer is provided by such a printing method, the thickness after drying may be adjusted to be about 0.001 to 10 μm.

(Functional thin film layer)
The functional thin film layer has a function of transmitting the light transmitted through the support base, the relief forming layer having a relief structure having a fine uneven pattern, and the first reflective layer. In addition, since the interference color is generated by the three-layer interference film of the first reflection layer, the functional thin film layer, and the second reflection layer, the functional thin film layer is an intermediate layer of the three-layer interference film. In general, a three-layer interference film is composed of a laminate of a high refractive layer, a low refractive layer, and a high refractive layer, so that the functional thin film of the intermediate layer is compared with the refractive index of the first reflective layer and the second reflective layer. The refractive index is preferably 0.2 or more. By setting the difference in refractive index to 0.2 or more, it becomes possible to cause refraction and reflection at the interface between the relief forming layer and the first reflective layer.

  In the second region, an interference color cannot be obtained because it is a laminate of two layers, the first reflective layer and the functional thin film layer.

  Since the functional thin film layer is an intermediate layer of the three-layer interference film of the first reflective layer, the functional thin film layer, and the second reflective layer, it is preferably a highly transparent low refractive film. Specifically, the functional thin film layer has the same or lower refractive index as the first reflective layer, and can cause reflection at both interfaces.

Examples of materials that can be used as a functional thin film layer having transparency are listed below. The numerical value in parentheses indicates the refractive index n. Ceramics are, 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 (5.0), WO ₃ (5.0), SiO (5.0), 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 (5.0), MgO (1. 0), SiO ₂ (1.45), Si ₂ O ₂ (10), MgF ₂ (4.0), CeF ₃ (1.0), CaF ₂ (1.3 to 1.4), AlF ₃ ( 1.0), Al ₂ O ₃ (1.0), GaO ₂ (2.0), or the like can be used. As the organic polymer, for example, polyethylene (1.51), polypropylene (1.49), polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49), polystyrene (1.60) and the like can be used. .

  The functional thin film layer is an intermediate layer of the three-layer interference film, and functions as an optical path difference adjusting layer for controlling the interference color, so that a thin film is formed with a uniform thickness along the fine uneven surface of the relief forming layer. Is preferred. For this reason, it is preferable to employ a vapor phase method (dry coating method), for example, a vacuum deposition method, a sputtering method, a CVD method, or the like, in forming the functional thin film layer.

(Second reflection layer)
The second reflective layer is provided along the relief structure, and reflects light transmitted through the relief forming layer, the first reflective layer, and the functional thin film layer. For the second reflective layer, a material having a refractive index higher than that of the functional thin film is used. In this case, the difference in refractive index between the two layers is preferably 0.2 or more.
By setting the difference in refractive index to 0.2 or more, it is possible to cause refraction and reflection at the interface between the functional thin film layer and the second reflective layer.

  As the material of the second reflective layer, for example, a single metal material such as Al, Sn, Cr, Ni, Cu, Au, or Ag, or a compound of these metals can be used.

Examples of other materials that can be used as the second reflective layer having transparency in addition to the metal and the compound are listed below. The numerical value in parentheses indicates the refractive index n. Ceramics are, 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 (5.0), WO ₃ (5.0), SiO (5.0), 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 (5.0), MgO (1. 0), SiO ₂ (1.45), Si ₂ O ₂ (10), MgF ₂ (4.0), CeF ₃ (1.0), CaF ₂ (1.3 to 1.4), AlF ₃ ( 1.0), Al ₂ O ₃ (1.0), GaO (2.0) can be used. For example, polyethylene (1.51), polypropylene (1.49), polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49), and polystyrene (1.60) can be used as the organic polymer. .

  The second reflective layer may be appropriately selected from the above materials in consideration of patterning by changing the reflectance or transparency by dissolution, corrosion, or alteration by, for example, an etching treatment agent in the manufacturing method described above. Good. In some cases, a plurality of materials may be used. In addition, when patterning a 2nd reflective layer, it is preferable to select suitably the material and process which do not reduce the reflective effect of a 1st reflective layer.

As a method for changing the reflectance or transmittance by dissolving the second reflective layer, the above-described method of subjecting the second reflective layer made of metal or metal oxide to wet etching can be employed. As the treating agent used for etching, known acids and alkalis, organic solvents, oxidizing agents, reducing agents and the like can be used. Depending on the material of the second reflective layer, a dry etching method may be used.
Also in such a patterning process of the second reflective layer, it is preferable that only the second reflective layer is patterned and the first reflective layer is not changed.

  The method of changing the reflectance or transmittance of the second reflective layer by alteration is, for example, a second reflective layer made of aluminum in which the second reflective layer made of copper is oxidized with an oxidizing agent to change to cuprous oxide. It is possible to employ a method such as oxidizing boehmite with an oxidizing agent. Also in such a patterning process of the second reflective layer, it is preferable that only the second reflective layer is patterned and the first reflective layer is not changed.

  In addition to the method of changing the dissolution and alteration characteristics of the second reflective layer, it is also possible to change optical properties such as refractive index, reflectance, and transmittance, and practical durability such as weather resistance and interlayer adhesion. is there.

  The second reflective layer preferably employs a dry coating method such as a vacuum deposition method, a sputtering method, or a CVD method in order to form a thin film with a uniform thickness on the fine uneven surface of the relief forming layer in the manufacturing method described above. .

(Protective layer)
The protective layer has optical transparency and functions as a mask layer when patterning the second reflective layer.

  The material used for the protective layer may be a material having resistance to an etching treatment agent when the second reflective layer is etched, and may be provided with a film thickness that can secure the resistance. For example, when the protective layer is formed by wet coating such as printing, for example, a thermoplastic resin, a thermosetting resin, a moisture curable resin, an ultraviolet curable resin, an electron beam curable resin, or the like can be used. Specific examples include acrylic resins, polyester resins, and polyamideimide resins. Further, a lubricant such as a wax such as polyethylene powder or carnauba wax may be added. The lubricant can be added in an amount up to 20 parts by weight so as not to become cloudy. Such a resin is applied to the wet coating to an appropriate viscosity by diluting with a solvent. On the other hand, when the protective layer is formed by dry coating, a transparent inorganic material such as silica or alumina is used. Photosensitive resin can be used as the material for the protective layer other than these.

  The protective layer of the anti-counterfeit structure shown in FIG. 1 is preferably formed by the wet coating.

  As the pattern formation method of the second reflective layer using the protective layer, a method of forming a pattern by changing the reflectance or transparency of the second reflective layer by dissolution, corrosion, or alteration as described above can be adopted.

  Typically, wet etching or dry etching is assumed, and in such a pattern formation method of the second reflective layer, a protective layer may be formed on the remaining second reflective layer pattern portion.

  As described above, each layer constituting the forgery prevention structure according to the first embodiment has been described in detail. However, a surface protective film is provided on the outermost surface to prevent scratches, and a reflective film is provided on the outermost surface to improve optical characteristics. It is also possible to provide. A known coating method can be used for the surface protective film or the reflective film.

  In order to improve adhesion between layers, corona treatment, flame treatment, plasma treatment, primer coating can be applied, and antireflection treatment can be applied to the outermost layer in order to improve optical characteristics.

  Furthermore, in order to improve the designability, it is good also as a multilayer interference film by coloring a layer and making a reflection layer into a multilayer structure.

  Next, another aspect of the forgery prevention structure according to the first embodiment will be described with reference to FIGS. 3 and 4. In addition, the same member as FIG. 1 mentioned above attaches | subjects a same sign, and abbreviate | omits description.

  FIG. 3 is a cross-sectional view showing a forgery prevention sticker. The anti-counterfeit sticker 21 has a structure in which a support base 22, a relief forming layer 2, a first reflective layer 3, a functional thin film layer 4, a second reflective layer 5, a protective layer 6, and an adhesive layer 23 are laminated in this order. It is.

  The anti-counterfeit sticker 21 having the above structure is used for transferring the relief forming layer 2, the first reflective layer 3, the functional thin film layer 4, the second reflective layer 5, and the protective layer 6 to another substrate (transfer object). Used, the adhesive layer 23 is used to adhere to another substrate. After the transfer, the support substrate 21 can be peeled off.

  By using such a forgery prevention sticker 21, it becomes possible to obtain a forgery prevention medium having a forgery prevention structure attached thereto.

  FIG. 4 is a cross-sectional view showing a forgery prevention transfer foil. The anti-counterfeit transfer foil 31 includes a peelable support base 32, a relief forming layer 2, a first reflective layer 3, a functional thin film layer 4, a second reflective layer 5, a protective layer 6, and an adhesive layer 33 laminated in this order. Has the structure.

  The anti-counterfeit transfer foil 31 is formed by pressing a heating medium such as a heat roll or a hot plate against the support base material 32 and heating the transfer medium to a transfer temperature to press the adhesive layer onto another base material to be transferred and a support base. The support base material 32 is peeled off at the interface between the material 32 and the relief forming layer 2.

  By using such an anti-counterfeit transfer foil 31, it becomes possible to obtain an anti-counterfeit medium in which an anti-counterfeit structure is attached to a transfer target.

  In the anti-counterfeit structure of FIGS. 3 and 4 described above, a peeling protective layer may be provided between the support base and the relief forming layer as necessary. A peeling protective layer is a layer for peeling off from a support base material smoothly and stably. For this reason, the release protective layer is made of a material having a good releasability with respect to the support substrate.

  In addition, as above-mentioned, the support base material used for a forgery prevention sticker and a forgery prevention transfer foil has a preferable film base material. As the film base material, it is desirable to use a material that is hardly deformed or deteriorated by heat, pressure, or electromagnetic waves applied at the time of forming a fine uneven pattern (relief structure). As the film substrate, for example, a plastic film such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PP (polypropylene) can be used. If necessary, paper, synthetic paper, plastic multilayer paper, resin-impregnated paper, or the like may be used as the supporting substrate.

(Second Embodiment)
FIG. 5 is a cross-sectional view showing a forgery prevention structure according to the second embodiment.

  The forgery prevention structure 41 has a structure in which a relief forming layer 42, a first reflective layer 43, a functional thin film layer 44, a second reflective layer 45, and a protective layer 46 are laminated in this order. One side of the relief forming layer 42 has a relief structure having a first relief 47 and a second relief 48 having a fine concavo-convex pattern that has an effect of diffracting, scattering, absorbing, and separating polarized light in at least a part of the wavelength region of visible light. . The surface of the first relief 47 has a smaller uneven surface area than the surface of the second relief 48. That is, the first relief 47 has a gentle shape with the concave and convex portions, and the interval between the concave and convex portions is wide. On the other hand, the second relief 48 has a concave portion and a convex portion that are steeper than the first relief 47, and the interval between the concave and convex portions is narrower than that of the first relief 47.

  The first reflective layer 43 and the functional thin film layer 44 are provided on the entire surface along the fine uneven surface of the relief structure (first and second reliefs 47 and 48). The second reflective layer 45 and the protective layer 46 are provided so as to cover only the surface of the functional thin film layer 44 of the first relief 47.

  That is, the first region 49 is a region in which the first reflective layer 43, the functional thin film layer 44, the second reflective layer 45, and the protective layer 46 are laminated in this order on the uneven surface of the first relief 47 of the relief forming layer 42. Thus, a colored reflective layer is obtained in which at least a partial region of visible light interferes with three layers including the first reflective layer 43, the functional thin film layer 44, and the second reflective layer 45. The three layers can also obtain a reflective layer whose color tone changes depending on the observation angle, and a relief structure having a colorful reflective layer can be designed.

  The colored reflective layer exists only in the first region 49, and only the patterned second reflective layer 45 is colored. In the first region 49, the patterned second reflective layer 45 itself is colored. As a result, since the second reflective layer 45 itself is a colored pattern, the colored ink is patterned and printed, and the reflective layer is formed so as to match the colored pattern. It is possible to avoid misalignment.

  The second region 50 is a region where only the first reflective layer 43 and the functional thin film layer 44 are laminated on the fine uneven surface of the second relief 48 of the relief forming layer 42, and the second reflective layer 45 and the protective layer 46 are not present. It is. For this reason, also in the 2nd field 50, it is possible to acquire the achromatic optical effect by a relief structure.

  The first region 49 and the second region 50 have different relief structures (first region 49: first relief 47, second region 50: second relief 48, uneven surface area: first relief 47 surface <second relief 48. It is possible to obtain different optical effects. For example, both structures are reliefs of diffraction gratings, and have different uneven surface areas, resulting in regions of different color change effects.

  Furthermore, since the forgery prevention structure 41 is a boundary of a relief structure in which the boundary between the first region 49 and the second region 50 is different, the pattern of the second reflective layer 45, the colored pattern, and the relief structure of the first region 49 There is no misalignment with the pattern (first relief 47).

  Therefore, the anti-counterfeit structure 41 according to the second embodiment includes a colored reflection relief structure in the first region 49 and an achromatic reflection relief in the second region 50, or different colors between the first and second regions 49 and 50. The change effect can provide a more precise and complicated optical effect, and thus can exhibit a higher anti-counterfeit effect.

  Next, a method for manufacturing a forgery prevention structure according to the second embodiment will be described.

1) 1st process A relief formation layer is formed in the whole surface on a support base material. The relief forming layer can be formed by coating, for example, wet coating, on the support substrate. The relief forming layer may be the support substrate itself.

  Next, a relief original plate made of metal or resin having an uneven shape is prepared, and the uneven shape of this original plate is transferred onto the surface of the relief forming layer to form a relief structure having a first relief and an uneven relief having the unevenness. Form into layers. Here, the uneven surface area of the first relief surface is smaller than that of the second relief surface. That is, the first relief has a wider interval between the irregularities than the interval between the irregularities of the second relief.

  The shape transfer method may be a known method such as the pressing method, casting method, or photopolymer method described in the first embodiment, or a hybrid method combining these methods.

(Second step)
The first reflective layer, the functional thin film layer, and the second reflective layer thin film layer are formed in this order on the relief structure surface of the relief forming layer.

  The first reflective layer and the functional thin film layer can be formed by a known wet coating or dry coating. The thin film layer for the second reflective layer is preferably formed by dry coating.

(Third step)
A protective film functioning as an etching mask is formed on the second reflective layer thin film layer. Subsequently, the second reflective layer is formed by selectively removing the second reflective thin film layer with an etching treatment agent using the protective film as a mask. That is, the second reflective film is formed leaving the second reflective layer thin film in the region below the protective film (first region 49), and the second reflective layer thin film layer in the other region (second region 50). Remove. Here, it is necessary not to remove the first reflective layer by etching.

  The forgery prevention structure according to the second embodiment is manufactured through the first to third steps described above, but is not limited thereto. The protective film and the second reflective film can be patterned by another method as described below. This will be described with reference to FIG. After the second reflective layer thin film layer 51 is formed on the entire surface of the functional thin film layer 44 by a vapor deposition method such as vacuum deposition or sputtering, the protective film 46 is formed by a vapor deposition method such as vacuum deposition or sputtering. Form on the entire surface. At this time, as shown in FIG. 6, the relief structure of the relief forming layer 42 includes the first relief 47 and the second relief 48 having a concave and convex interval narrower than the relief 47, so the second reflective layer thin film layer 51 and the protective layer 46 is formed with a sufficient thickness in the first region 49 where the first relief 47 is located, and is thinly formed only at the tip of the concavo-convex convex portion in the second region 50 where the second relief 48 is located. For this reason, when the subsequent entire surface etching process is performed, the protective layer 46 and the thin film layer 51 for the second reflective layer that are thinly formed only at the tips of the convex portions of the second region 50 are preferentially etched and removed. Only in one region 49, the second reflective layer thin film layer 51 (functioning as the second reflective layer 45) and the protective layer 46 remain and are patterned.

  The protective layer 46 is made of a transparent inorganic material such as silica or alumina.

  According to such a method, the second reflective layer 45 (and the protective layer 46) can be formed on the first relief (first region) in a self-aligned manner in accordance with the shapes of the first and second reliefs 47 and 48 set in advance. For this reason, it is possible to color only the first region, and it is possible to obtain the optical effect of the relief in which the first region and the second region are different.

  In addition, the material of each layer which comprises the forgery prevention structure which concerns on 2nd Embodiment, and a required characteristic are the same as that of having demonstrated in 1st Embodiment.

  Further, the anti-counterfeit structure according to the second embodiment may be another mode as shown in FIG. 3 (anti-counterfeit sticker) and FIG. 4 (anti-counterfeit transfer foil). By using such an anti-counterfeit sticker and an anti-counterfeit transfer foil, an anti-counterfeit medium having an anti-counterfeit structure attached thereto can be obtained.

Examples of the present invention will be described below (Example 1).
In the first embodiment, the configuration in FIG. 3 will be described as a representative example. The relief forming layer 2 was formed by applying and drying an ink composed of the following composition on a support 11 composed of a transparent polyethylene terephthalate (PET) film having a thickness of 25 μm and drying it so that the film thickness after drying was 2 μm. Subsequently, a relief pattern of a diffraction grating was formed on the surface of the relief forming layer 2 by a roll embossing method. Titanium oxide (TiO ₂ ) is vacuum-deposited on the relief forming layer 2 to form a first reflective layer 3 having a thickness of 50 nm along the relief pattern, and silica (SiO ₂ ) is vacuum-deposited on the first reflective layer 3. Thus, a functional thin film layer 4 having a thickness of 130 nm was formed. Subsequently, aluminum was vacuum deposited on the functional thin film layer 4 to form an aluminum layer having a thickness of 50 nm. Subsequently, the ink which consists of the following composition was printed on the aluminum layer with the gravure printing method, and the protective layer 6 of the star-shaped pattern was formed. The thickness of the protective layer 6 was 1 μm as a dry film thickness. Thereafter, the exposed aluminum layer portion was etched by performing an alkali etching process using the protective layer 6 as an etching mask to form a second reflective layer 5 having a star pattern. Then, the ink which consists of the following composition was printed on the functional thin film layer 4 containing the protective layer 6 by the gravure printing method, and it dried and formed the contact bonding layer 23 with a film thickness of 3 micrometers, and the forgery prevention sticker 21 was obtained.

"Relief forming layer ink composition"
Acrylic resin 20.0 parts by weight Methyl ethyl ketone 50.0 parts by weight Ethyl acetate 30.0 parts by weight “Protective layer ink composition”
Polyamide resin 20.0 parts by weight Ethanol 50.0 parts by weight Toluene 30.0 parts by weight “Adhesive layer ink composition”
Acrylic adhesive 50 parts by weight Silica 10 parts by weight Methyl ethyl ketone 40 parts by weight (Comparative Example 1)
As shown in (a) of FIG. 7, an ink composed of the following composition was printed on the support substrate 101 by a gravure printing method to form a colored layer 102 having a star pattern. Subsequently, a relief forming layer 103 was formed on the base material 101 including the colored layer 102 by the same method as in Example 1, and a relief structure 104 having fine irregularities on one side of the relief forming layer 103 was formed. Subsequently, aluminum was vacuum-deposited on the relief forming layer 103 to form an aluminum layer (not shown) having a thickness of 50 nm. Subsequently, the protective layer ink composition similar to Example 1 was printed on the aluminum layer by the gravure printing method, and the protective layer 105 of the star pattern was formed. The thickness of the protective layer 105 was 1 μm in terms of dry film thickness. Next, the exposed aluminum layer portion was etched by performing an alkali etching process using the protective layer 105 as an etching mask to form a reflective layer 106 (shown in FIG. 7B). Thereafter, although not shown, the same adhesive layer ink composition as in Example 1 is printed on the concavo-convex surface of the relief forming layer including the protective layer in the same manner as in Example 1 by the gravure printing method, and dried to form an adhesive layer having a thickness of 3 μm. Formed a forgery prevention sticker.

  In addition, the coloring layer of the star pattern and the protective layer of the star pattern were aligned as much as possible by overprinting (overlapping register printing) of a gravure printing machine.

"Pattern colored layer ink composition"
Urethane printing ink / yellow 50.0 parts by weight Methyl ethyl ketone 25.0 parts by weight Ethyl acetate 25.0 parts by weight The anti-counterfeiting stickers of Example 1 and Comparative Example 1 thus obtained were evaluated for anti-counterfeiting.

[Evaluation of anti-counterfeiting]
After taking a magnified picture with a microscope, the "colored reflective layer area" and "reflective layer area (Example 1 is the second reflective layer area, Comparative Example 1 is the reflective layer area)" of the star pattern by photographic image analysis software Area ratio (colored reflective layer area mm ² / reflective layer area mm ² (Example 1 is the second reflective layer area, Comparative Example 1 is the reflective layer area)). Further, after taking an enlarged photograph with a microscope, photographic image analysis was performed, and a positional deviation width (mm) between the “colored reflective layer area” and the “second reflective layer area” was measured.

As for the area ratio (mmm ² / mmm ² ) and the positional deviation width (mm), 20 points were measured, and the average value and the maximum value were obtained.

The results are shown in Table 1 below.

  As is clear from Table 1, the forgery prevention structure of Example 1 is good when the area ratio is 1.00 and the positional deviation is 0.00 mm (less than 0.01 mm below the measurement limit). The anti-counterfeit structure 1 has an area ratio of 1.02 and a positional deviation of 1.00 mm at the maximum.

  Moreover, also in visual observation of the forgery prevention structure of Comparative Example 1, it was possible to confirm the displacement of the colored layer with respect to the reflective layer.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the anti-counterfeit structure with a desired color tone and an anti-counterfeit which is excellent in design property and / or security property regarding the anti-counterfeit structure having high design property and high security property. Since the structure can be provided, it can be used for securities, branded products, certificates, personal authentication media, and the like.

  DESCRIPTION OF SYMBOLS 1,41 ... Anti-counterfeit structure, 2,42 ... Relief formation layer, 3,43 ... 1st reflective layer, 4,44 ... Functional thin film layer, 5,45 ... 2nd reflective layer, 6,46 ... Protective layer 8, 49 ... 1st region, 9, 50 ... 2nd region, 47 ... 1st relief, 48 ... 2nd relief, 11, 22, 32 ... support base material.

Claims (6)

Relief forming layer, the first reflective layer, laminated functional thin film layer, a second reflective layer and a protective layer in this order,
The first reflective layer, the functional thin film layer, and the second reflective layer produce an interference color by a three-layer interference film,
The functional thin film layer is an intermediate layer of a three-layer interference film,
The functional thin film layer is a ceramic,
One side of the relief forming layer has a relief structure having a fine uneven pattern,
The first reflective layer and the functional thin film layer are provided on the entire surface along the unevenness of the relief structure,
The second reflective layer is provided in an arbitrary region covering a part of the unevenness of the relief structure,
The protective layer is provided so as to cover only the region of the second reflective layer,
Between the relief forming layer and the second reflective layer, only the first reflective layer and the functional thin film layer exist,
A forgery prevention structure characterized in that the three layers of the first reflective layer, the functional thin film layer, and the second reflective layer interfere with at least a partial region of visible light.   The first reflective layer includes at least one selected from the group consisting of tantalum oxide, niobium oxide, titanium oxide, indium tin oxide, zirconium oxide, cerium oxide, and hafnium oxide. Item 14. An anti-counterfeit structure according to Item 1.   The forgery prevention structure according to claim 1, wherein the relief structure has at least one of a diffraction structure, a hologram, a condensing lens array, a diffusing lens array, and a scattering structure at least partially in the same plane. body.   An anti-counterfeit structure laminated on at least a support substrate, wherein a relief forming layer, a first reflection layer, a functional thin film layer, a second reflection layer, a protective layer and an adhesive layer are arranged in this order on the support substrate. The anti-counterfeit structure according to any one of claims 1 to 3, wherein the structure is a laminated sticker structure.   Having at least a supporting substrate, and laminating a relief forming layer, a first reflective layer, a functional thin film layer, a second reflecting layer, a protective layer and an adhesive layer in this order on the supporting substrate, The forgery prevention structure according to any one of claims 1 to 3, which has a transfer foil configuration that can be peeled off from the substrate. An anti-counterfeit medium having at least the anti-counterfeit structure according to claim 1 attached thereto.

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