JP5549059B2 - Anti-counterfeit structure, anti-counterfeit single body using the same, and authenticity determination method thereof - Google Patents

Description

  The present invention relates to an anti-counterfeit structure for use in anti-counterfeiting sheets such as gift certificates, credit cards, and other securities, or stickers such as branded goods and luxury goods, and a method for determining authenticity thereof.

  In recent years, as a measure to prevent counterfeiting of banknotes, gift certificates, credit cards, etc., and as proof of authenticity such as brand products and luxury products, changes in colors and images depending on the viewing angle of holograms, diffraction gratings, multilayer thin films, etc. OVD (Optically Variable Device, which is also abbreviated as “Differential Optically Variable Imaging Device”) is frequently used.

  These OVDs require advanced manufacturing technology, have a unique visual effect, and can be judged at a glance as authenticity, so they can be formed on credit cards, securities, certificates, etc. as part of or on the entire surface as an effective counterfeit measure. Is being used. Recently, in addition to securities, it is affixed to sports equipment, computer parts and other electrical products and software, etc., and authentication stickers that prove the authenticity of the products, and seal stickers that are affixed to the packages of those products Has come to be widely used.

  However, in recent years, with the widespread use of hologram production technology, rudimentary hologram images have been easily forged. On the other hand, the multilayer type OVD has become widely available in the field of packaging materials other than anti-counterfeiting applications, and thus has become easy to obtain, and its anti-counterfeiting effect has been lost.

Therefore, there is a need for a new anti-counterfeiting technology capable of discriminating authenticity from the appearance of holograms and multilayer thin-film OVDs, and the present applicant discloses an example of a technology related to a forgery-preventing structure that can be easily visually discriminated. (For example, refer to Patent Document 1).
Japanese Patent Application No. 2007-272409

  However, the invention disclosed above is obtained when the diffracted light in the regular reflection direction from the forgery prevention structure and the observation point and the light source are arranged on the same side with respect to the forgery prevention structure. This is a method of determining authenticity only by the difference in the color tone of the diffracted light in the retroreflective direction, and there is a problem that it cannot be easily distinguished in practice depending on the difference in light intensity and the color discrimination power of the observer. It was. Therefore, in order to verify reliably, it must be compared with a genuine product.

  The present invention solves the problems of the prior art by the applicant of the present invention, and the problem is that the determination can be made easily by enabling the determination of authenticity without comparing with the genuine product. And anti-counterfeit structure and anti-counterfeit single body using the anti-counterfeit structure that can be discriminated regardless of the difference in light intensity and the color discrimination power of the observer, and its authenticity determination It is to provide a method.

In the first aspect of the present invention, the average particle size is 0.2 to 0.8 μm and the number of particles included in the range of 0.8 to 1.2 times the average particle size is 70% or more of the total number of particles. is monodisperse spherical particles, in the state of the area fill factor is 30% or more monolayers, the monodisperse spherical half height or polymeric resin material polymer resin so as not buried in the particles A diffractive structure part that is fixed in the whole surface or in an arbitrary shape and includes a reflective layer that reflects light below the monodispersed spherical fine particles, and two printed parts so as to exhibit a color tone similar to the diffractive structure part The anti-counterfeiting structure is characterized in that a black ink layer is provided in advance, and pearl ink is printed thereon, and has a printing portion in which the interference color of the pearl pigment is further strengthened.

  By adopting such a configuration, a completely different pattern is observed depending on the viewing angle.

Wherein the invention the monodisperse spherical fine particles according to claim 2, consists of monodispersed fine spherical particles of two or more different average particle diameters, where each monodispersed spherical particles, having a specific single layer area The anti-counterfeit structure according to claim 1 is provided.

  With such a configuration, more various patterns are observed.

  The invention according to claim 3 is the anti-counterfeit structure according to claim 1 or 2, wherein the printing portion contains a pearl pigment having a pearly luster.

  The invention according to claim 4 is a forgery-preventing sheet material comprising the anti-counterfeit structure according to any one of claims 1 to 3 formed on a substrate. It is.

  Invention of Claim 5 is the forgery prevention structure body of Claim 1 in any one of Claim 1 to Claim 3, or the forgery prevention method of the forgery prevention sheet material of Claim 4. The pattern observed in the regular reflection direction when the anti-counterfeit structure is arranged between the observation point of the authenticator and the light source, and the observation point and the light source are the same with respect to the anti-counterfeit structure In the authenticity determination method, the authenticity of the forgery-preventing structure is determined based on the difference in the pattern observed from the recursion direction.

Since the present invention has the above configuration, the pattern observed in the regular reflection direction obtained when the anti-counterfeit structure is arranged between the observation point where the authenticator is present and the light source, and the anti-counterfeit The pattern observed when the observation point and the light source are arranged on the same side of the structure can be clearly identified, and the light intensity and the color discrimination power of the observer It does not depend on the difference.
Therefore, the authenticity can be easily and quickly determined based on whether or not the identified patterns are different.

  First, the outline of the present invention will be described with reference to the drawings.

  1 and 2 are plan views of a forgery-preventing structure sheet according to the present invention, which has a diffractive structure portion 2 and a same color printing portion 3 on a base material 11. In FIG. 1, regions where the diffractive structure portion 2 and the same color printing portion 3 are provided have similar color tones, and both are observed in the observation from the regular reflection direction with respect to the light source (FIG. 6). A “●” in the same color printing unit 3 as the letter “T” consisting of On the other hand, when observed from the same direction as the light source (FIG. 7), only the diffracted light from the diffractive structure 2 is observed, so that only the letter “T” is clearly recognized.

  Similarly, in FIG. 2, the letter “TOP” is observed in the regular reflection direction (FIG. 6), but only the letter “O” is clearly observed when observed from the same direction as the light source (FIG. 7). In this way, it is possible to easily find a change in the pattern, and it is possible to ensure authenticity determination.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a forgery-preventing structure single wafer according to the present invention will be described in detail with reference to the drawings.

  FIG. 3 is a cross-sectional view of the forgery-preventing structure single-wafer of the present invention, and shows a cross-section of a broken line portion A of the plan view shown in FIG. A diffractive structure 2 formed by laminating a reflective layer 13, spherical fine particles 15 and a resin layer 16 fixing the fine particles on an adhesive layer 12 on a base material 11, and the same color printed using printing ink A printing unit 3 is provided.

First, the diffractive structure 2 of the present invention will be described.
The spherical fine particles 15 are layers that diffract light in observation from a specific direction. Specifically, diffracted light is not observed in the observation from the regular reflection direction with respect to the light source (FIG. 6), and only black, dark colors, or colors in a specific narrow wavelength range can be visually recognized. On the other hand, the observation from the recursion direction (FIG. 7) has a function of generating diffracted light having a wavelength in the vivid visible light region.

  As the spherical fine particles, monodispersed spherical fine particles are suitable. Examples of the material include organic materials such as acrylic and polystyrene, and inorganic particles such as silica and titanium oxide, but are not limited thereto. Any dispersed spherical fine particles can be used. Here, the degree of monodispersity is preferably in a narrower range. This is because, by narrowing the particle size distribution, variations in diffraction angle are reduced, so that vivid color tone changes can be obtained. The spherical fine particles in the present invention are spherical fine particles having a narrow particle size distribution having a particle number of 70% or more of the total number of particles in the range of 0.8 times or more and 1.2 times or less of the average particle diameter. More preferably, it is a spherical fine particle having a particle number of 90% or more in the range of 0.9 times or more and 1.1 times or less of the average particle diameter. By using spherical particles having such a sharp particle size distribution, a more vivid color tone change can be obtained.

  On the other hand, the particle diameter is preferably selected from the range of 0.2 to 0.8 μm according to the desired diffraction wavelength. When using diffraction in the visible light region, since the diffracted light in the second or higher order visible light region is generated when the particle diameter is 0.8 μm or more, the color tone observed from the same direction as the color tone observed from the regular reflection direction Changes will be smaller. Furthermore, since the diffraction efficiency is small, it is difficult to identify the difference. On the other hand, when the thickness is 0.2 μm or less, visible diffracted light cannot be obtained (refer to Patent Document 1 for details).

  On the other hand, it is preferable that the accumulated shape of the spherical fine particles is arranged so that the fine particles overlap each other and are packed more densely in a planar direction in a single particle film shape. When particles are stacked randomly in two or more layers, light of each wavelength diffracted by the first layer of the lowermost layer is scattered in random directions in the second and subsequent layers, resulting in a decrease in color intensity and an observation angle. It is impossible to obtain a vivid color change due to. In addition, when placed on an uneven surface instead of a flat surface, the color intensity of the fine particles on the uneven surface decreases when incident light or the observation angle is shallow, resulting in a vivid color tone change depending on the observation angle. It becomes impossible. The degree of filling is preferably such that the area occupied by the particles relative to the area of the planar region where the particles are present, that is, the area filling rate is 30% or more, more preferably 60% or more. When the area filling rate is less than 30%, the intensity of color development due to diffraction decreases, and a vivid color tone change depending on the observation angle cannot be obtained.

  These spherical fine particles 15 are fixed by the resin layer 16. As the resin material, it is necessary to adhere to the spherical fine particles 15, hardly flow at room temperature, and to be transparent, and examples thereof include organic polymer materials such as acrylic and polyester. It is not limited to these. However, as a feature of the present invention, since the diffraction phenomenon cannot be obtained if the entire spherical particle is covered with the resin layer 15, the film thickness is adjusted to be about half the diameter of the particle.

  Next, the reflective layer 13 is made of a reflective material provided so as to cover the spherical fine particles 15, and reflects the light transmitted through the spherical fine particles 15. Examples of the material for the reflective layer 13 include simple substances such as Al, Sn, Cr, Ni, Cu, Au, and Ag, or compounds thereof. Ink or metal that deposits a metal material by vapor deposition or heat is used. Any method for providing a reflective film, such as a method for providing ink in which fine particles are dispersed by printing, can be used.

  The adhesive layer 12 is a layer for adhering and fixing the diffractive structure portion 2 of the present invention to the base material 11, and examples thereof include organic polymer resin materials such as acrylic and polyester, but are not limited thereto. Any material that can be used for fixing may be used.

Next, the same color printing unit 3 will be described in detail.
The same color printing unit 3 is provided using printing ink having a color similar to the color tone obtained when the diffractive structure unit 2 is observed from the regular reflection direction (FIG. 6). The diffractive structure 2 of the present invention exhibits a black or dark color or a color in a specific narrow wavelength range in the observation from the regular reflection direction (FIG. 6), and color inks similar to these are prepared. Print. It is difficult to prevent the diffracted light from being included at all in the color exhibited by the diffractive structure portion 2, and weak diffracted light is always included. Therefore, by using the interference color of the pearl pigment in the same color printing portion 3 It is possible to reproduce close colors. At this time, in order to further enhance the interference color of the pearl pigment, the printing unit 3 can be divided into two layers, a black ink layer is provided in advance, and the pearl ink can be printed thereon.

  As described above, the forgery prevention structure of the present invention has been described. However, it is also possible to partially provide the same color printing part 3 on the diffraction structure part 2 or to provide the diffraction structure part 2 on a part of the same color printing part 3. The same effect can be exhibited. In addition, an anchor layer can be provided between each layer for improving adhesion, and each layer can be colored for improving design.

  Further, when the forgery prevention structure of the present invention is formed on a material that is difficult to directly form, it can be easily formed by using the transfer foil or sticker shown in FIGS.

  Next, these will be briefly described.

The transfer foil shown in FIG. 4 has a transfer foil base 41, a release layer 42 made of an organic polymer resin that easily peels from the transfer foil base 41, the resin layer 16, the fine particles 15, and the reflective layer 13 described above in order. It is configured by laminating and further providing a heat-sensitive adhesive layer 43.
Heat and pressure are applied from the substrate 41 side of the transfer foil, the heat-sensitive adhesive layer 43 is melted and bonded to the substrate 11, and then the transfer foil substrate 41 is peeled off. Is easily provided.

On the other hand, the sticker shown in FIG. 5 has a portion formed by sequentially laminating the resin layer 16, the fine particles 15, and the reflective layer 13 described above on the sticker substrate 51, and a portion provided with the printing unit 3 described above. Further, the pressure-sensitive adhesive layer 52 is laminated on the entire surface.
If this sticker is used, it is possible to easily adhere the forgery prevention structure 1 of the present invention to a three-dimensional object such as a box that is difficult to be directly printed or transferred.

<Example 1>
First, the transfer foil for producing the diffractive structure shown in FIG. 4 was produced.
The following layers were sequentially laminated on a 25 μm PET film serving as the transfer foil substrate 41 to obtain a transfer foil.
1) 5 μm of the release layer 42 was applied. (The blending ratio is shown below.)
2) 0.3 to 0.5 μm of ink composed of the resin layer 16 and the fine particles 15 (mixing ratio is shown below)
3) An Al vapor deposition layer of 50 nm was provided as a reflective layer.
4) 3 μm of heat-sensitive adhesive layer 43 was applied. (The blending ratio is shown below.)
(Peeling layer ink)
Acrylic 20 parts ethyl acetate 60 parts butyl acetate 20 parts (resin layer 16 ink in which particles 15 are dispersed)
Polyvinyl alcohol 1 part Monodispersed styrene fine particles (0.3 μm diameter) 20 parts Water 79 parts (adhesive layer ink)
Polyester 20 parts Silica filler 1 part Ethyl acetate 49 parts Butyl acetate 30 parts

The transfer foil obtained as described above was transferred to a vinyl chloride card having a thickness of 0.8 mm as the base material 1 to produce a diffractive structure 2. The shape is a “T” shape as shown in FIG.
Since the letter “T” exhibits a dark green color when observed in the specular direction, the same color printing unit 3 was printed using a dark green pearl pigment ink so as to exhibit a similar color tone.

  Next, the card thus obtained was verified.

[Observation from regular reflection direction (Fig. 6)]
The dark green “T” character and the same color printing unit 3 showing a similar color tone were observed, and the overall shape of the recognized shape was the shape of “●”.

[Observation from the same direction (Fig. 7)]
Only the letter portion “T” emitted bright blue-green diffracted light, and the letter T could be clearly observed. On the other hand, there was no color development from the portion of the same color printing portion 3 showing a similar color tone, and the shape was not observed and could not be identified. Eventually, the only recognized shape was the letter “T”.

  That is, since the shape observed from the same direction and the shape observed from the regular reflection direction are clearly different, it is possible to facilitate the authenticity determination.

The top view which shows one Example of the forgery prevention structure of this invention The top view which shows one Example of the forgery prevention structure of this invention Sectional drawing which shows one Example of the forgery prevention structure of this invention Cross-sectional view of transfer foil with diffractive structure Sectional drawing which shows the forgery prevention structure sticker of this invention The figure which shows the relationship of the observation position at the time of observing the forgery prevention structure of this invention (regular reflection direction) The figure which shows the relationship of the observation position at the time of observing the forgery prevention structure of this invention (same direction)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Anti-counterfeit structure 2 ... Diffraction structure part 3 ... Same color printing part 4 ... Spherical fine particle 11 ... Base material 12 ... Adhesive layer 13 ... Reflective layer 15 ... Fine particles 16 ... Resin layer 41 ... Transfer foil base material 43 ... Heat sensitive adhesive layer 51 ... Sticker base material 52 ... Adhesive layer 60 ... light source 61 ... observation point 62 ... light to be observed

Claims (5)

Monodisperse Spherical microparticles number of particles having an average particle diameter contained and to 0.8 to 1.2 times the range of the average particle diameter 0.2~0.8μm is 70% or more of the total number of particles, In the state of a single layer with an area filling rate of 30% or more, it is fixed to the polymer resin in the whole surface or in an arbitrary shape so that more than half of the height of the monodispersed spherical fine particles is not buried in the polymer resin material. The diffractive structure having a reflective layer that reflects light below the monodispersed spherical fine particles, and the printing part is divided into two layers so as to exhibit a color tone similar to the diffractive structure, and a black ink layer is provided in advance. And an anti-counterfeit structure characterized by having a printed part on which pearl ink is printed and the interference color of the pearl pigment is further strengthened. The monodisperse spherical fine particles, is composed of a monodisperse spherical fine particles of two or more different average particle sizes, each of the monodisperse spherical fine particles, according to claim 1, characterized in that it has a unique single-layer region Anti-counterfeit structure.   The forgery prevention structure according to claim 1 or 2, wherein the printing part contains a pearl pigment having a pearly luster.   A forgery-preventing sheet material comprising the anti-counterfeit structure according to any one of claims 1 to 3 formed on a substrate.   A method for determining the authenticity of a forgery-preventing structure according to any one of claims 1 to 3, or an anti-counterfeit structure according to claim 4, comprising: When the anti-counterfeit structure is arranged between the light source and the pattern observed in the specular reflection direction, the observation point and the light source are arranged on the same side with respect to the anti-counterfeit structure A true / false determination method, wherein the authenticity of the forgery-preventing structure is determined based on a pattern difference observed from the recursion direction.