JP2010025974A - Forgery prevention structure and counterfeit prevention medium using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forgery prevention structure that has superior productivity and capability of making any one to discriminate truth or falsehood at a glance with a simple verifying method, to which a specific pattern is attached as the case may be, and that simultaneously holds productivity, discrimination of genuineness with ease, and forgery prevention effect, and also to provide a counterfeit prevention medium using the structure. <P>SOLUTION: On a supporting body, there are superimposed a diffractive structure forming layer, a diffractive structure reflection layer, a spherical particulate resin layer with spherical particulates densely arranged on a resin layer, and a spherical particulate reflection layer. By forming the diffractive structure reflection layer or the spherical particulate reflection layer in an optional pattern, a forgery prevention structure having a novel visual effect is provided. A counterfeit prevention medium uses the structure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an anti-counterfeit structure and an anti-counterfeit medium using the same for securities such as gift certificates and credit cards, or stickers for branded products and luxury products.

  In recent years, so-called OVD has been used as an anti-counterfeiting measure for banknotes, gift certificates, credit cards, and the like, and as proof of authenticity of brand and high-end products. As used herein, OVD is an abbreviation for “Optical (ly) Variable Device”. Note that DOVID is also a synonym for OVD, which is an abbreviation of “Differential Optical (ly) Variable Imaging Device”.

  The manufacture of this OVD requires advanced technology, and since it has a unique visual effect and can determine authenticity at a glance, it is widely used in credit cards, securities, certificates, etc. as an effective counterfeiting measure. It's being used. Recently, in addition to securities, it is affixed to sports equipment, computer parts and other electrical products, software, etc., and as an authentication sticker to prove the authenticity of the product, and affixed to the package of those products. It is also used as a sealed sticker.

  OVD is generally an anti-counterfeiting means that is difficult to elaborate and is easy to check for authenticity, and there are many thermal transfer methods that are not easy to replace when pasting on paper media such as gift certificates, banknotes, passports or stock certificates. The case has been adopted. This is because when an OVD that has been thermally transferred is to be replaced, the optical thin film used in the OVD is physically destroyed, and the original visual effect is impaired, thereby providing an effect of preventing replacement and tampering. That's why.

  However, due to the recent development of embossing technology, OVD using relief-type diffractive structures has become less difficult than before, and multilayer thin film films have begun to be sold as general packaging films. The prevention effect is decreasing.

  On the other hand, the relief type diffractive structure in recent years proposes a complicated design with a finer structure, and an antireflection function by an element (subwavelength structure element) composed of a fine periodic uneven pattern below the wavelength of light, Proposals have been made for articles having a change separation function, a phase difference function, etc., and computer generated holograms.

  An ordinary relief type diffraction grating has a width of about 1.0 μm and an unevenness of a depth of about 0.2 μm. Compared to this, in the case of the sub-wavelength structural element and the computer generated hologram, the Forgery is difficult because of the fine irregularities below the wavelength.

Regarding such a forgery prevention structure, for example, there are the following patent documents.
Japanese Patent Laid-Open No. 2002-40219 JP 2004-205990 A JP 2005-10231 A

  However, in order to form the fine concavo-convex shape, a known technique such as a heat embossing method or a photopolymer method is used, and in any method, a resin is taken into a relief mold at the time of molding, This has led to a decline in the yield rate. In particular, when a finer structure or a structure having a higher aspect ratio is used, the resin taken into this relief type is remarkable. In addition, there is a problem that productivity is poor because processing at high speed is difficult, and novel optical effects cannot be obtained simply by narrowing the period of the diffraction grating.

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is high productivity, and anyone can determine its authenticity at a glance by a simple verification method. An object of the present invention is to provide a forgery prevention structure having both productivity, easiness of authenticity determination and anti-counterfeiting effect, and a forgery prevention medium using the same.

  In order to solve the above-described problems, the present invention provides at least a diffraction structure forming layer, a diffraction structure reflection layer, a spherical fine particle resin layer in which a plurality of spherical fine particles are densely arranged on a resin layer, and a spherical fine particle reflection. The anti-counterfeit structure is formed by laminating layers in this order, and the diffraction structure reflection layer is provided in a pattern.

  Further, the present invention provides the anti-counterfeit structure, wherein a chemical-resistant protective layer is further laminated at least in a portion corresponding to the diffraction structure reflection layer between the diffraction structure reflection layer and the spherical fine particle resin layer. It is characterized by.

  In the present invention, a spherical fine particle resin layer, a spherical fine particle reflective layer, a diffractive structure forming layer, and a diffractive structure reflective layer in which a plurality of spherical fine particles are densely arranged on at least a resin layer are laminated in this order on a support. The anti-counterfeit structure is characterized in that the spherical fine particle reflective layer is provided in a pattern.

  Further, the present invention provides the anti-counterfeit structure, further comprising a chemical protective layer laminated at least in a portion corresponding to the spherical fine particle reflective layer between the spherical fine particle reflective layer and the diffraction structure forming layer. It is characterized by.

  In the forgery prevention structure, the present invention provides the spherical fine particle resin layer having a plurality of spherical fine particles having an average particle size of 2.5 μm or less and a particle size distribution of 0.8 to 1 of the average particle size. The number of particles is 70% or more within the range of 2 times, and the spherical fine particles are embedded and fixed in the resin layer at half or less of the height thereof, and the area filling rate with respect to the surface area of the resin layer is It is characterized by being 30% or more.

  In the anti-counterfeit structure according to the present invention, the spherical fine particle resin layer is composed of two or more regions, and the spherical fine particles constituting the first region and the spherical fine particles constituting the second region are Having a different average particle diameter, and in each region, the number of particles is 70% or more within a range of 0.8 to 1.2 times the average particle diameter. Less than half of the height is buried and fixed in the resin layer, and the area filling rate with respect to the surface area of the forgery prevention structure is 30% or more.

  Further, the present invention is characterized in that in the anti-counterfeit structure, an adhesive layer is further laminated on the surface opposite to the support side.

  Further, the present invention is the forgery prevention structure characterized in that in the forgery prevention structure, an adhesive layer is laminated on a surface opposite to the support side, and a peeling protective layer is further provided on the support. .

  The present invention is also a forgery prevention medium obtained by attaching the forgery prevention structure or the forgery prevention transfer foil to a substrate.

  Since this invention is the above structure, there exist the following effects.

  That is, according to the present invention, a conventional general diffraction structure forming layer having a diffraction structure composed of a hologram, a diffraction grating, or the like, a corresponding diffraction structure reflection layer, and a plurality of spherical fine particles are densely arranged in the resin layer. By laminating the spherical fine particle resin layer and the corresponding spherical fine particle reflective layer, and providing the reflective layer on the viewing side of the diffraction structure reflective layer and the spherical fine particle reflective layer in a pattern, both optical effects are obtained. It is possible to provide an anti-counterfeit structure, an anti-counterfeit transfer foil, and an anti-counterfeit medium using the same, which are observed in a pattern and have an unprecedented visual effect.

  Further, the spherical fine particle resin layer is divided into two or more regions, and by changing the average particle size of the spherical fine particles constituting the first region and the spherical fine particles constituting the second region, Reflected light or diffracted light is visually recognized in the form of a pattern, and it is possible to impart a further advanced visual effect and anti-counterfeit effect.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an anti-counterfeit structure according to the present invention and anti-counterfeit media using them will be described in detail below with reference to the drawings.

  FIG. 1 is a cross-sectional view showing an embodiment of a forgery prevention structure according to the present invention. The anti-counterfeit structure (1) includes a diffraction structure forming layer (12), a diffraction structure reflection layer (13), a spherical fine particle resin layer (14), a spherical fine particle reflection layer (15), and a support (11). The adhesive layer (16) is laminated in this order. The diffractive structure reflective layer is provided in a pattern. The spherical fine particle resin layer (14) has a resin layer (141) and spherical fine particles (142), and has a configuration in which a plurality of spherical fine particles are densely arranged on the resin layer. The height embedded in the resin layer of the spherical fine particles is adjusted to be less than half of the particle size of the spherical fine particles and arranged without overlapping each other, and the area filling rate with respect to the surface area of the resin layer is 30% or more. It is formed to be.

  The anti-counterfeit structure shown in FIG. 1 is provided with a diffraction structure reflection layer in a pattern, so that in the portion where the diffraction structure reflection layer is formed, the diffracted light by the diffraction structure formed by the diffraction structure formation layer is formed. Is visible. Further, in the portion where the diffractive structure reflective layer is not formed, the following optical effect is obtained by the spherical fine particle resin layer positioned below the diffractive structure reflective layer.

  The optical effect observed from the spherical fine particle resin layer is due to the light shade of gray such as a grayish white that is milky white due to scattered light including diffracted light in the range of 0 ° to 60 ° with respect to the vertical direction of the spherical fine particle resin layer. An optical change is observed, and it can be confirmed that the color changes from milky gray to a vivid color tone such as blue-green at an angle close to the horizontal of 60 ° or more with respect to the vertical direction.

  FIG. 2 shows a forgery prevention structure (1) shown in FIG. 1 in which a chemical-resistant protective layer (17) is further laminated between the diffraction structure reflection layer (13) and the spherical fine particle resin layer (14). It is sectional drawing of a prevention structure. The chemical-resistant protective layer is formed in a shape corresponding to the patterned diffractive structure reflective layer.

  FIG. 3 shows an anti-counterfeit structure in which a peeling protective layer (18) is laminated between the support (11) and the diffraction structure forming layer (12) of the anti-counterfeit structure (1) shown in FIG. It is sectional drawing of 3). The anti-counterfeiting layer is a layer for peeling off and removing the support after the anti-counterfeit transfer foil has been applied to the substrate to be transferred by heat, pressure, etc. This anti-counterfeit structure can be used as an anti-counterfeit transfer foil It is.

  FIG. 4 is a cross-sectional view showing another embodiment of the forgery prevention structure according to the present application. The anti-counterfeit structure (4) includes a spherical fine particle resin layer (14), a spherical fine particle reflective layer (15), a diffractive structure forming layer (12), a diffractive structure reflective layer (13), on a support (11). The adhesive layer (16) is laminated in this order. The spherical fine particle reflective layer (15) is provided in a pattern.

  In the anti-counterfeit structure (4) shown in FIG. 4, the spherical fine particle reflective layer (15) is provided in a pattern, so that the spherical fine particle reflective layer is not formed in the portion where the spherical fine particle reflective layer (15) is not formed. The optical effect by the diffraction structure forming layer (12) located in the lower part of (15) is visually recognized. Further, in the portion where the spherical fine particle reflective layer (15) is formed, the optical effect by the spherical fine particle resin layer (14) as described above is obtained. However, since the layer structure is different, the luminance of the diffraction structure forming layer (12) and the color change due to the spherical fine particle resin layer (14) are different from those of the forgery prevention structure (1).

  FIG. 5 shows a region (143) in which the spherical fine particle resin layer (14) of the anti-counterfeit structure (1) shown in FIG. 1 is composed of spherical fine particles having a small average particle diameter and spherical fine particles having a large average particle diameter. It is sectional drawing of the example of an embodiment in the case of having a structure composed of a plurality of regions combined with a region (144). In this configuration, by using spherical fine particles having different average particle sizes, the region (143) and the region (144) each have a color that changes optically and an angular range in which the color can be observed. Each is different.

  FIG. 6 is a cross-sectional view showing an embodiment of the forgery prevention medium according to the present invention. This anti-counterfeit medium (6) has a structure in which the anti-counterfeit structure (1) shown in FIG. 1 is attached to a transfer substrate (21).

  FIG. 7 is a cross-sectional view showing another embodiment of the forgery prevention medium according to the present invention. This anti-counterfeit medium (7) is produced by transferring the anti-counterfeit structure (3) shown in FIG. 3 to a substrate (21) to be transferred and peeling the support (11).

  FIG. 8 is a cross-sectional view showing still another embodiment of the forgery prevention medium according to the present invention. This anti-counterfeit medium (8) is produced by sticking the anti-counterfeit structure (4) shown in FIG. 4 to a substrate (21) to be transferred.

  Hereinafter, the constituent elements of the present invention will be described in more detail.

  A resin film or the like can be used as the support. As the resin film, a polyethylene terephthalate resin film, a polyethylene naphthalate resin film, a polyimide resin film, a polyethylene resin film, a polypropylene resin film, a heat-resistant vinyl chloride film, or the like can be used. In particular, a polyethylene terephthalate resin film is preferable because of its high heat resistance and stable thickness. In addition, films obtained by subjecting these resin films to processing such as antistatic treatment, mat processing, embossing, printing of characters and patterns, laser marking, and the like can also be used.

  The diffraction structure forming layer records a diffraction grating by forming a fine concavo-convex pattern on the layer surface, and a diffraction structure such as a relief type diffraction grating or a volume type diffraction grating can be used.

  The relief type diffraction grating uses, for example, two-beam interferometry to irradiate the surface of the photosensitive resin with two coherent light beams to generate interference fringes, and the interference fringes are photosensitive in the form of irregularities. It can be formed by recording on a resin. It is possible to record an arbitrary three-dimensional image as a diffraction grating pattern by selecting two light beams, and it is also possible to record a different image (changing image) according to an observation angle. In addition to the two-beam interference method, the method of recording an image pattern on the diffractive structure layer can be manufactured by a conventionally known hologram manufacturing method such as an image hologram, a Lippmann hologram, a rainbow hologram, or an integral hologram. Is possible.

  As another method, it is also possible to form an uneven pattern of a relief type diffraction grating by irradiating the surface of the electron beam curable resin with an electron beam and exposing it to a striped pattern to be a diffraction grating. In this case, since an interference fringe can be controlled for each line, it is possible to record an arbitrary stereoscopic image or changing image. It is also possible to divide an image into dot-like pixel areas, record different diffraction gratings for each pixel area, and express the entire image by a set of these pixels. The pixel may be a circular dot or a star-shaped dot.

It is also possible to form a concavo-convex pattern by an induced surface relief forming method. That is, by irradiating a polymer amorphous thin film having azobenzene on the chain side with a relatively weak light of several tens mW / cm ² having a wavelength in the range of blue to green, a polymer molecule on a scale of several μm. It is possible to form an uneven pattern on the surface of the thin film.

  As the resin applied to the diffraction structure forming layer, a thermoplastic resin, a thermosetting resin, an ultraviolet ray, an electron beam curable resin, or the like can be used. Examples of the thermoplastic resin include acrylic resins, epoxy resins, cellulose resins, and vinyl resins. In addition, urethane resins, melamine resins, phenol resins, and the like obtained by adding polyisocyanate as a crosslinking agent to an acrylic polyol or polyester polyol having a reactive hydroxyl group and crosslinking can be used. Moreover, epoxy (meth) acryl, urethane (meth) acrylate, or the like can be used as the ultraviolet or electron beam curable resin.

  The diffractive structure reflecting layer does not need to be provided in direct contact with the diffractive structure forming layer, but when the diffractive structure forming layer is a relief type diffraction grating, it is necessary to provide the diffractive structure reflecting layer in direct contact with the concavo-convex pattern. There is. In this case, the light reflected by the diffractive structure reflective layer is diffracted light.

  Moreover, as a material for the diffractive structure reflective layer, a metal thin film can be preferably used in terms of high reflection luminance. Examples of the metal include Al, Sn, Cr, Ni, Cu, Au, and brass. And this metal thin film can be formed using a vacuum film-forming method. As the vacuum film formation method, a vacuum deposition method, a sputtering method, or the like can be applied, and the thickness may be controlled to about 5 to 1000 nm.

  It is also possible to form a diffractive structure reflective layer on the entire surface or in any shape by applying and drying ink with metallic luster by a known printing method such as gravure printing or screen printing. is there.

  By forming a chemical-resistant protective layer on the diffractive structure reflective layer, it is possible to improve the chemical resistance of the diffractive structure reflective layer. Examples of the material for the chemical protection layer include polyvinyl alcohol resin, vinyl chloride resin, epoxy resin, polyurethane resin, polyethylene resin, polymethyl methacrylate resin, ABS (acrylonitrile-butadiene-styrene) resin, polyamide resin, polycarbonate resin, Polyarylate resin, polysulfone resin, polyethersulfone resin, polyetherimide resin, cyclic polyolefin copolymer, modified norbornene resin, polyamideimide resin, polyimide resin, etc. it can. In addition, a thermosetting resin, a moisture curable resin, an ultraviolet curable resin, or an electron beam curable resin may be used. In addition, a filler, a filler, a colorant, etc. can be added up to 40% by weight when the specific gravity of these resins is 1. When added over 40% by weight, the dispersibility is deteriorated, the coating film strength is lowered, and the heat resistance may be inferior. In addition, the fluidity of the coating liquid becomes low and the printability deteriorates due to drying on the plate, and those additives in the coating liquid settle or aggregate during storage or coating. Etc.

  When the diffractive structure reflective layer is provided in a pattern such as an arbitrary image pattern or character pattern, the chemical-resistant protective layer can be applied to any image pattern or character pattern of the diffractive structure reflective layer by the following method. It can be formed in the shape.

  First, a diffractive structure reflecting layer is uniformly formed on the entire surface, and a resin having chemical resistance is provided in a pattern as a chemical resistant protective layer on the diffractive structure reflecting layer and exposed by applying an alkaline or acidic etching solution. And a method of dissolving and removing the reflecting structure reflecting layer. In addition, a touristic resin is formed as a chemical-resistant protective layer on the diffractive structure reflective layer that is uniformly formed on the entire surface, and after exposure and development in a pattern, an alkaline or acidic etching solution is applied to expose the exposed diffraction. Although there is a method of dissolving and removing the structural reflection layer, the method is not limited to these methods as long as the diffraction structure reflection layer and the chemical-resistant protective layer can be formed into corresponding shapes.

  The pattern formed by the diffractive structure reflective layer and the chemical-resistant protective layer may be a random pattern having no clear meaning, but can be recognized as a pattern such as a pattern, figure, pattern, letter, number, symbol, etc. It is also possible to give information.

  As the spherical fine particles used as the spherical fine particle resin layer, those having an average particle size of 2.5 μm or less are used. The spherical fine particle resin layer is characterized in that uniform spherical fine particles are accumulated to efficiently obtain light diffraction by the fine particles. In particular, in order to obtain a vivid color tone change due to a high color developability and an observation angle, the shape, particle size distribution, and integrated shape of the spherical fine particles are important, and details will be described below.

  The shape of the spherical fine particles used in the spherical fine particle resin layer is preferably as true as possible. This is because, when the fine particles are made into a spherical shape, the direction dependency of the particle diameter is reduced, the variation in diffraction angle is reduced, and a vivid color tone change can be obtained. Specifically, it is desirable that the ratio between the maximum diameter and the minimum diameter of each fine particle is in the range of 1.0 to 1.2.

  Since the wavelength region diffracted by the spherical fine particles covers all of the ultraviolet light region, visible light region, and infrared light region (wavelength 2500 nm or less), the particle size of the spherical fine particles used is preferably 2.5 μm or less. This is because if the thickness is 2.5 μm or less, all diffracted light of 2500 nm or less can be obtained.

  The particle size distribution of the spherical fine particles is preferably in a narrow range with little variation in particle size. This is because by narrowing the particle size distribution, the variation in diffraction angle is reduced and a more vivid color tone change can be obtained. Specifically, the number of particles is preferably 70% or more within a range of 0.8 to 1.2 times the average particle size. Furthermore, by using spherical particles with a sharp particle size distribution such that the number of particles is 90% or more within the range of 0.9 to 1.1 times the average particle size, a more vivid color tone change can be obtained. Is also possible.

  It is preferable that a larger amount of spherical fine particles be arranged on the resin layer in a single plane state. When particles are stacked randomly more than double, the light intensity of each wavelength diffracted at the first is scattered in a random direction at the second and subsequent times, resulting in a decrease in color intensity and a further observation angle. The vivid color change due to can not be obtained. In addition, when arranged on an uneven surface instead of a flat state, the color intensity in the situation where the incident light or the observation angle is shallow is reduced with respect to the uneven fine particles, and as a result, the bright color depending on the observation angle is reduced. Color change cannot be obtained.

  Here, the average particle size and the particle size distribution can be confirmed by SEM (scanning electron microscope) or TEM (transmission electron microscope). Moreover, confirmation of the ratio between the maximum diameter and the minimum diameter of each particle can also be performed by observation with SEM or TEM. For this reason, in measuring the particle size, it is necessary to collect data by unifying either the maximum diameter or the minimum diameter of one particle. In the present invention, data is collected by unifying the maximum diameter.

In addition, the area filling rate of the spherical fine particles with respect to the surface area of the forgery prevention structure is preferably 30% or more, and more preferably 60% or more. This is because if it is less than 30%, the color intensity is lowered, and vivid color tone change depending on the observation angle cannot be obtained. This area filling rate is the particle area per unit area when observed with SEM or TEM from the direction perpendicular to the plane of the anti-counterfeit structure (the particle area of one particle is the area of a circle with an average particle diameter) The area range to be calculated and measured is preferably 400 μm ² or more. In the present invention, the range of 2500 μm ² is arbitrarily selected at five locations, and the number of particles in the range is calculated to calculate the area of the particles. The filling rate was calculated.

  As the material of the spherical fine particles, organic material-based or inorganic material-based monodispersed spherical fine particles are preferable. Monodisperse spherical fine particles of organic materials include acrylic, polystyrene, polyester, polyimide, polyolefin, poly (meth) acrylate methyl, polyethylene, polypropylene, polyether sulfone, polyamide, nylon, polyurethane, polyvinyl chloride, polychlorinated Examples thereof include resins such as vinylidene and acrylamide, and copolymer resins composed of two or more of these resins. Inorganic material-based monodisperse spherical fine particles include calcium carbonate, barium carbonate, magnesium carbonate, calcium silicate, barium silicate, magnesium silicate, calcium phosphate, barium phosphate, magnesium phosphate, silica, titanium oxide, and iron oxide. Cobalt, zinc oxide, nickel oxide, manganese oxide, aluminum oxide, iron hydroxide, nickel hydroxide, aluminum hydroxide, calcium hydroxide, chromium hydroxide, zinc silicate, aluminum silicate, zinc carbonate, basic copper carbonate, zinc sulfide , Glass, various metal particles, and the like. Further, surface-modified fine particles, core-shell particles, laminated spherical particles, bead-shaped spherical particles, and the like using two or more of these organic materials and inorganic materials are also included. Further, hollow spherical particles using these organic materials and inorganic materials, spherical aggregates of fine particles, porous spherical particles, thermally expandable spherical particles, and the like can be cited as examples, but the spherical fine particles of the present invention are limited to this. It is not a thing.

  Furthermore, by combining multiple diffraction effects by spherical fine particles, collecting spherical fine particles with different particle diameters in each region, multilayering the spherical fine particle diffraction structure, and further verifying diffraction in multiple wavelengths and wavelength regions By using it as light, it becomes possible to obtain more complicated optical effects.

  The resin layer is a layer for fixing the spherical fine particles. For example, when the resin layer is provided by coating, a known coating (printing) resin, adhesive resin, thermal adhesive resin, thermoplastic resin It is possible to use resins such as thermosetting resin, ultraviolet curable resin, ionizing radiation curable resin, etc., good adhesion with spherical fine particles, and required physical properties from among resins that can fix spherical fine particles The solvent may be appropriately selected depending on the solvent, and the solvent may be aqueous or solvent-based.

  Further, the resin layer may be a crosslinking agent itself or a resin obtained by adding a crosslinking agent to the resin. Examples of the crosslinking agent include isocyanate group-containing compounds, epoxy group-containing compounds, carbodiimide group-containing compounds, oxazoline group-containing compounds, silanol group-containing compounds, and the like. With these cross-linking agents, cross-linking within the resin layer, cross-linking between the spherical fine particles, or the resin layer and the spherical fine particles may be cross-linked. Moreover, you may provide the reactive group required for bridge | crosslinking with a resin layer and spherical fine particles, or may add the catalyst for raising a crosslinking density. Moreover, you may use the self-crosslinking type resin which has a functional group required for the said bridge | crosslinking in a polymer.

  As a method for forming the spherical fine particle resin layer, for example, a liquefied material of the resin layer, or a component obtained by diluting a component constituting the resin layer with a solvent is applied by a known printing method, and the resin layer is coated on the resin layer. After sprinkling the spherical fine particles, the fine particles are fixed on the resin layer by chemical reaction such as crosslinking reaction, thermosetting reaction, photopolymerization reaction, etc. or solvent drying of the resin, and the excess is not fixed by the resin layer. The spherical fine particles can be formed by physically removing them by a process such as suction, air blowing, and solvent washing, but may be formed by other methods as long as desired conditions are satisfied.

  The spherical fine particle reflective layer is an optical thin film provided so as to be in contact with the spherical fine particle resin layer, and has a function of reflecting light transmitted through the spherical fine particle resin layer. Examples of the material for the spherical fine particle reflective layer include a simple substance of a metal material such as Al, Sn, Cr, Ni, Cu, Au, Ag, or brass, or a compound thereof, as in the diffraction structure reflective layer. A vacuum film-forming method such as a vacuum deposition method or a sputtering method can be used, and the thickness may be controlled to about 5 to 1000 nm. Moreover, you may form with the ink with metallic luster.

  As in the case of the diffractive structure reflective layer, a chemical-resistant protective layer may be formed on the spherical fine particle reflective layer, and when the spherical fine particle reflective layer is provided in a pattern such as an arbitrary image pattern or character pattern, Similarly to the case of the diffractive structure reflective layer, the chemical-resistant protective layer may be formed in a shape corresponding to the pattern of the spherical fine particle reflective layer.

  When the anti-counterfeit structure of the present invention has a transfer foil structure, a peeling protective layer is provided. The peel protection layer can be peeled off from the support after being transferred by hot pressure, and also functions as a protection layer for the forgery prevention structure after the transfer. As a material for the release protective layer, a resin added with a lubricant can be used. As the resin, a thermoplastic resin, a thermosetting resin, a moisture curable resin, an ultraviolet curable resin, an electron beam curable resin, and the like can be used, and examples thereof include an acrylic resin, a polyester resin, and a polyamideimide resin. As the lubricant, wax such as polyethylene powder or carnauba wax can be used, and it can be added up to 20 parts by weight. The release protective layer is formed on the support by a known coating method such as a gravure printing method or a micro gravure method using these materials.

  In order to bond the anti-counterfeit structure to a transfer target substrate to form an anti-counterfeit medium, it is necessary to provide an adhesive layer as the outermost layer. Any adhesive layer may be used as long as it adheres to the substrate to be transferred by heat and pressure, and an appropriate material is selected from known adhesive materials in consideration of the material and surface shape of the substrate to be transferred. I can do things. Examples of the substrate to be transferred include paper, plastic, and synthetic paper, but are not limited thereto.

  In addition, in order to improve the design, it is possible to color each of the above-mentioned layers and spherical fine particles, or to print on the surface or between layers, and to make the step of the layer formed in a pattern form inconspicuous May be applied. In view of the adhesiveness of each layer, an adhesion anchor layer may be provided between the layers, or various easy adhesion treatments such as corona discharge treatment, plasma treatment, and frame treatment may be performed.

  Furthermore, for the purpose of removing light other than the diffracted light of the spherical fine particles, a black layer (light absorption layer) or a colored layer (specific wavelength absorption layer) is provided on the entire surface or in an arbitrary pattern below the forgery prevention structure. It is also possible to additionally provide a reflection layer or a scattering layer for reflecting and scattering light other than the diffracted light of the spherical fine particles in the regular reflection direction.

Example 1
A transparent polyethylene terephthalate (PET) film having a thickness of 25 μm was used as the support (11), and an ink comprising the following composition was applied to one side of the support (11) by a bar coating method at 100 ° C. After drying for 1 minute to form a layer with a thickness of 1 μm, the embossed shape is used to generate a diffraction grating on the surface at a processing speed of 5 m / min by heating the press plate for forming the diffraction grating to 160 ° C. by roll embossing. To form a diffraction structure forming layer (12).

  Next, an evaporation mask for forming the diffractive structure reflecting layer (13) in an arbitrary shape is disposed on the diffractive structure forming layer (12), and an aluminum evaporated film is formed at a film thickness of 50 nm by vacuum evaporation. After uniform formation, the vapor deposition mask was removed, and a diffraction structure reflection layer (13) having an arbitrary pattern shape was formed.

  Next, an ink composed of the following composition as a resin required for the resin layer (141) was applied by a bar coating method and dried at 120 ° C. for 3 minutes to form a layer having a thickness of 0.2 μm. 142) 3500B (styrene particles manufactured by Moritex Co., Ltd .: particle size 500 nm, containing 90% or more of particles in the range of 0.8 to 1.2 times the average particle size) is sprayed on the resin layer. Then, after drying again at 120 ° C. for 3 minutes, the fine particles not fixed by the suction machine were removed by suction to obtain a spherical fine particle resin layer (14). Here, it was confirmed by SEM that the particles were arranged in a single plane with an area filling rate of 70% or more.

  Next, on this spherical fine particle resin layer (14), the aluminum vapor deposition film was uniformly formed with a film thickness of 50 nm by the vacuum vapor deposition method, and it was set as the spherical fine particle reflective layer (15).

  Next, an ink composed of a writing composition was applied by a bar coating method and dried at 120 ° C. for 3 minutes to form an adhesive layer (16) having a thickness of 8 μm, thereby producing a forgery prevention structure (1) sticker. .

"Diffraction structure forming layer ink composition"
Urethane resin 20.0 parts by weight Methyl ethyl ketone 50.0 parts by weight Ethyl acetate 30.0 parts by weight

"Resin layer ink composition"
Acrylic resin (adhesive) 35.0 parts by weight Methyl ethyl ketone 35.0 parts by weight Toluene 30.0 parts by weight

"Adhesive layer ink composition"
Acrylic resin (adhesive) 40.0 parts by weight Methyl ethyl ketone 30.0 parts by weight Toluene 30.0 parts by weight

  Since the anti-counterfeit structure (1) thus obtained is a sticker whose adhesive layer (16) is an adhesive, the anti-counterfeit medium (3) is directly pasted on a paper on which a desired print such as a character or a pattern has been printed in advance. Was made.

  When this anti-counterfeit medium (1) is observed from near the front under a normal light source, a clear image of the diffracted light from the diffraction structure forming layer can be observed in the portion where the diffraction structure reflection layer is formed. It was. In addition, in the part where the diffractive structure reflecting layer is not formed, when observed from the front, the diffracted light from the diffractive structure forming layer is not observed, but the diffracted light from the spherical fine particle resin layer is observed. When observed from an angle of 30 ° or less with respect to the horizontal direction of the medium, a change in color from milky dark gray to blue-green was observed, and it was confirmed that there was an optical change that has not existed before. .

(Example 2)
A transparent PET film having a thickness of 25 μm was used as the support (11). On one side of this support (11), an ink comprising the following composition was applied by a bar coating method and dried at 100 ° C. for 1 minute to form a release protective layer (18) having a thickness of 2 μm.

  Next, an ink comprising the following composition was applied by a bar coating method, dried at 100 ° C. for 30 seconds to form a layer having a thickness of 1 μm, and then a press plate for forming a diffraction grating was formed at 160 ° C. by a roll embossing method. And an embossed shape for generating a diffraction grating on the surface was formed at a processing speed of 5 m / min to obtain a diffraction structure forming layer (12).

  Next, an evaporation mask for forming the diffractive structure reflecting layer (13) in an arbitrary shape is disposed on the diffractive structure forming layer (12), and an aluminum evaporated film is formed at a film thickness of 50 nm by vacuum evaporation. After uniform formation, the vapor deposition mask was removed, and a diffraction structure reflection layer (13) having an arbitrary shape was formed.

  Next, as a resin for the resin layer (141), an ink composed of the following composition was applied by a bar coating method and dried at 120 ° C. for 3 minutes to form a layer having a thickness of 0.2 μm. 142) 3500B (Mortex Co., Ltd. styrene particles: particle size 500 nm, containing 90% or more particles in the range of 0.8 to 1.2 times the average particle size) is sprayed on the resin layer. Then, after drying again at 120 ° C. for 3 minutes, the fine particles not fixed by the suction machine were removed by suction to obtain a spherical fine particle resin layer (14). Here, it was confirmed by SEM that the particles were arranged in a single plane with an area filling rate of 70% or more.

  Next, on this spherical fine particle resin layer (14), the aluminum vapor deposition film was uniformly formed with a film thickness of 50 nm by the vacuum vapor deposition method, and it was set as the spherical fine particle reflective layer (15).

  Next, an ink comprising the following composition was applied by a bar coating method and dried at 120 ° C. for 1 minute to form an adhesive layer (16) having a thickness of 3 μm, thereby producing a forgery prevention structure (3).

"Peeling protective layer ink composition"
Polyamideimide resin (Tg. 250 ° C.) 19.2 parts by weight Polyethylene powder 0.8 parts by weight Dimethylacetamide 45.0 parts by weight Toluene 35.0 parts by weight

"Diffraction structure forming layer ink composition"
Urethane resin 20.0 parts by weight Methyl ethyl ketone 50.0 parts by weight Ethyl acetate 30.0 parts by weight

"Resin layer ink composition"
Acrylic resin (adhesive) 35.0 parts by weight Methyl ethyl ketone 35.0 parts by weight Toluene 30.0 parts by weight

"Adhesive layer ink composition"
Vinyl chloride vinyl acetate copolymer resin 15.0 parts by weight Acrylic resin (Tg. 20 ° C.) 10.0 parts by weight Silica 1.0 part by weight Methyl ethyl ketone 44.0 parts by weight Toluene 30.0 parts by weight

  This anti-counterfeit structure (3) is overlaid on a plastic card that has been printed in advance, such as letters and pictures, and is thermally transferred to the plastic card using a circular hot roll type transfer machine heated to a temperature of 140 ° C. Immediately after, the support (11) was peeled and removed to produce an anti-counterfeit medium (7).

  When this anti-counterfeit medium (7) is also observed from the front near a normal light source, a clear image of the diffracted light from the diffractive structure forming layer can be observed in the portion where the diffractive structure reflective layer is formed. It was. In addition, in the part where the diffraction structure reflecting layer is not formed, when observed from near the front, diffracted light by the diffractive structure forming layer is not observed, but diffracted light by the spherical fine particle resin layer is observed, and forgery prevention When observed from an angle of 30 ° or less with respect to the horizontal direction of the medium, a change in color from milky dark gray to blue-green was observed, and it was confirmed that there was an optical change that has not existed before. .

(Example 3)
As the support (11), a transparent PET film having a thickness of 25 μm was used. On the one side of the support (11), an ink comprising the following composition was applied by a bar coating method and dried at 120 ° C. for 3 minutes. After forming a resin layer with a film thickness of 0.2 μm, as spherical fine particles (142), 3500B (Mortex Co., Ltd. styrene particles: particle size 500 nm, range of 0.8 to 1.2 times the average particle size) Sprayed on the resin layer and dried again at 120 ° C. for 3 minutes, and then the fine particles not fixed by suction were removed by suction, and the spherical fine particle resin layer ( 14). Here, it was confirmed by SEM that the spherical fine particles were arranged in a single plane with an area filling rate of 70% or more.

  Next, a vapor deposition mask for forming a spherical fine particle reflective layer (15) having an arbitrary shape is disposed on the spherical fine particle resin layer (14), and an aluminum vapor deposited film is formed to a thickness of 50 nm by vacuum vapor deposition. After uniform formation, the vapor deposition mask was removed, and a spherical fine particle reflective layer (15) having an arbitrary shape was formed.

  Next, an ink comprising the following composition was applied by a bar coating method, dried at 100 ° C. for 1 minute to form a layer having a thickness of 1 μm, and then a press plate for forming a diffraction grating was formed at 160 ° C. by a roll embossing method. And an embossed shape for generating a diffraction grating on the surface was formed at a processing speed of 5 m / min to obtain a diffraction structure forming layer (12).

  Next, an aluminum vapor deposition film was uniformly formed with a film thickness of 50 nm on the diffraction structure forming layer (12) by a vacuum vapor deposition method to form a diffraction structure reflection layer (13).

  Next, an ink composed of the following composition is applied by a bar coating method and dried at 120 ° C. for 3 minutes to form an adhesive layer (16) having a thickness of 8 μm, thereby producing a forgery prevention structure (4) sticker. did.

"Resin layer ink composition"
Acrylic resin (adhesive) 35.0 parts by weight Methyl ethyl ketone 35.0 parts by weight Toluene 30.0 parts by weight

"Diffraction structure forming layer ink composition"
Urethane resin 20.0 parts by weight Methyl ethyl ketone 50.0 parts by weight Ethyl acetate 30.0 parts by weight

"Adhesive layer ink composition"
Acrylic resin (adhesive) 40.0 parts by weight Methyl ethyl ketone 30.0 parts by weight Toluene 30.0 parts by weight

  Since the anti-counterfeit structure (4) thus obtained is a sticker whose adhesive layer (16) is an adhesive, the anti-counterfeit medium (8) is pasted as it is on a paper on which desired printing such as letters and patterns has been performed in advance. Was made.

  When the anti-counterfeit medium (8) is observed from the vicinity of the front surface under a normal light source, diffracted light from the spherical fine particle resin layer is observed in the portion where the spherical fine particle reflective layer (15) is formed, and further anti-counterfeiting is achieved. When observed from an angle of 30 ° or less with respect to the horizontal direction of the medium, it is possible to observe a change in color from milky white to dark blue. In addition, in the part where the spherical fine particle reflective layer (15) is not formed, a clear image of the diffracted light by the diffractive structure forming layer can be observed, and it has been confirmed that there is an optical change that has not existed before. did it.

It is sectional drawing which shows the example of embodiment of the forgery prevention structure which concerns on this invention. It is sectional drawing which shows the forgery prevention structure body which provided the chemical-resistant protective layer in the forgery prevention structure body of FIG. It is sectional drawing which shows the forgery prevention structure body which provided the peeling protection layer in the forgery prevention structure body of FIG. It is sectional drawing which shows another example of embodiment of the forgery prevention structure which concerns on this invention. It is sectional drawing which shows the application example of the forgery prevention structure of FIG. It is sectional drawing which shows the forgery prevention medium formed by sticking the forgery prevention structure of FIG. 1 to a base material. It is sectional drawing which shows the forgery prevention medium formed by transferring the forgery prevention structure of FIG. 3 to a base material. FIG. 5 is a cross-sectional view showing an anti-counterfeit medium formed by attaching the anti-counterfeit structure of FIG.

Explanation of symbols

1, 2, 3, 4, 5 Anti-counterfeit structure 6, 7, 8 Anti-counterfeit medium 11 Support 12 Diffraction structure forming layer 13 Diffraction structure reflection layer 14 Spherical fine particle resin layer 141 Resin layer 142 Spherical fine particles 143 Average particle size Area composed of small spherical fine particles 144 Area composed of spherical fine particles having a large average particle diameter 15 Spherical fine particle reflective layer 16 Adhesive layer 17 Chemical-resistant protective layer 18 Peeling protective layer 21 Transfer target substrate

Claims (9)

  An anti-counterfeit structure in which at least a diffraction structure forming layer, a diffraction structure reflection layer, a spherical fine particle resin layer in which a plurality of spherical fine particles are densely arranged on a resin layer, and a spherical fine particle reflection layer are laminated in this order on a support. An anti-counterfeit structure characterized in that the diffraction structure reflective layer is provided in a pattern.   The counterfeit according to claim 1, wherein a chemical-resistant protective layer is further laminated on at least a portion corresponding to the diffraction structure reflection layer between the diffraction structure reflection layer and the spherical fine particle resin layer. Prevention structure.   An anti-counterfeit structure in which a spherical fine particle resin layer, a spherical fine particle reflective layer, a diffractive structure forming layer, and a diffractive structure reflective layer, in which a plurality of spherical fine particles are densely arranged on at least a resin layer, are laminated in this order on a support. A forgery-preventing structure, wherein the spherical fine particle reflective layer is provided in a pattern.   The counterfeit according to claim 3, wherein a chemical-resistant protective layer is further laminated at least in a portion corresponding to the spherical fine particle reflective layer between the spherical fine particle reflective layer and the diffraction structure forming layer. Prevention structure.   A plurality of spherical fine particles constituting the spherical fine particle resin layer have an average particle size of 2.5 μm or less and a particle size distribution of 0.8% to 1.2 times the average particle size and the number of particles of 70% or more. Furthermore, the spherical fine particles are embedded in and fixed to the resin layer at half or less of the height thereof, and the area filling rate with respect to the surface area of the forgery prevention structure is 30% or more. Item 5. The forgery prevention structure according to any one of Items 1 to 4.   The spherical fine particle resin layer is composed of two or more regions, and the spherical fine particles constituting the first region and the spherical fine particles constituting the second region have different average particle diameters. The number of particles is 70% or more within the range of 0.8 to 1.2 times the average particle diameter, and the spherical fine particles are embedded and fixed in the resin layer at half or less of their height. The forgery prevention structure according to any one of claims 1 to 4, wherein an area filling rate with respect to a surface area of the forgery prevention structure is 30% or more.   The forgery prevention structure according to any one of claims 1 to 6, wherein an adhesive layer is laminated on a surface opposite to the support side.   The forgery prevention structure according to any one of claims 1 to 6, wherein an adhesive layer is laminated on a surface opposite to the support, and a peeling protective layer is further provided on the support.   An anti-counterfeit medium comprising the anti-counterfeit structure according to claim 7 or the anti-counterfeit transfer foil according to claim 8 attached to a substrate to be transferred.

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