JP5304109B2 - Display body and expression method of optical effect function - Google Patents

Description

  The present invention relates to a display body that causes a change in reflected color in accordance with a change in viewing angle, and in particular, it is easy to determine authenticity by visual observation, makes counterfeiting, tampering, and alteration difficult, and reuse after peeling. The present invention relates to a display body to be prevented and a method for expressing an optical effect function.

  Conventionally, as a means for preventing counterfeiting, it is difficult to imitate the article itself, or a thing that is difficult to imitate is attached to the article as a proof that it is genuine, so that genuine and counterfeit are There is something that can be distinguished. Typical examples of the latter include holograms such as relief holograms, diffraction gratings, and Lippmann holograms that are frequently used in recent years. Among them, for example, a relief hologram is an image in which an image is formed in a fine concavo-convex shape, so that an inherent viewing angle (that is, the angle at which the hologram is supported) depends on the diffraction and interference of light. Since a color shift (color change of reflected light) occurs and the visible color differs depending on the observation position, it can be easily determined whether or not it is genuine by checking the presence or absence of the state. . However, in recent years, since the hologram as described above has a simple hologram principle and configuration such as layers, forgery is becoming easier to counterfeit.

  Therefore, there is a multilayer thin film layer in which thin films such as ceramics and metals with different optical characteristics are laminated on a base material as an effect of color shift (color change of reflected light) according to the viewing angle similar to this hologram. . These utilize the interference effect of light obtained by the optical characteristics and film thickness of the thin film, have reflection / transmission characteristics in a specific wavelength range, and this reflection / transmission characteristics change depending on the observation position, Since the visible colors are different, it is possible to easily determine whether or not the color is genuine by checking the presence or absence of the state.

  Patent Document 1 discloses an optically variable color thin film product having a multilayer interference film on one side of an upper layer having an optical thickness carrying a colorant such as a dye and having two generally transparent front and back surfaces. ing. Patent Document 2 discloses a seal provided on a base material with a functional layer that reflects or transmits light in a specific wavelength region by alternately combining ceramics having a low refractive index and a high refractive index. . In addition, if the base material for forming the multilayer film is a transparent film, the color change may be difficult to understand, and a dark colored layer such as black or a metal reflective film may be added as a base of the multilayer film. In Patent Document 3, in order to increase the anti-counterfeit effect, a laminated layer in which a transparent vapor-deposited layer, a transparent protective layer, and ceramic materials having different refractive indexes are alternately laminated to a specific thickness on a metal-deposited substrate or metal foil The body is disclosed.

  Patent Document 4 discloses a copy-prevented printed matter in which a functional layer and a printing layer in which a plurality of ceramic materials having different refractive indexes are laminated on a base material are sequentially provided. In these color shifts (color changes of reflected light), the color change depending on the viewing angle makes it possible to determine the authenticity of counterfeit products, and in particular, the optical characteristics of those copied illegally by copying machines, color copying machines, etc. Since it is impossible to reproduce the image, forgery / alteration is difficult, and even if forgery / alteration is made, it has the effect of giving up its use.

For example, the anti-counterfeit medium, the seal, or the functional layer in which a plurality of ceramic materials having different refractive indexes are laminated on the base material and the adhesive layer are sequentially formed as disclosed in Patent Document 5, for example. A multilayer thin film layer is held as the provided transfer foil or transfer sheet, and these are attached to an article by adhesion or transfer. Further, it is possible to form a diffractive structure on the multilayer film by embossing, transferring, or pasting. As a further addition of security, in particular, considering the layer structure, it is difficult to peel off the seal, or as disclosed in Patent Document 6, a partially formed release layer having a plurality of different refractive indexes is formed on the substrate. It is configured so that it is difficult to regenerate after peeling, such as a brittle seal with a ceramic material laminated functional layer and adhesive layer in order. Once attached, it is peeled off and part or all of the optical functional layer As a result of the destruction, it is possible to determine at a glance that something has been added to the article, such as tampering, as well as counterfeiting. Furthermore, the multi-layered thin film laminated on the transparent substrate is formed with irregularities that do not generate interference light, so-called embossed parts, and the embossed part and the non-embossed part have different colors when viewed from the front. Proposed.
JP-A-61-105509 Japanese Patent Laid-Open No. 7-146649 JP 7-199812 A JP 7-214960 A JP 7-144500 A Japanese Patent Laid-Open No. 7-146650

  However, a multilayer thin film in which thin films such as ceramics and metals with different optical properties are laminated on a base material is very easy to determine authenticity, and the structure of the multilayer thin film is also difficult to understand, so it has a high anti-counterfeit effect. On the other hand, since only one multilayer thin film is formed uniformly or as a pattern on the surface of the substrate, the color shift must be a single one, and has the disadvantage of poor color and design. As a result, no visible information is given that it is difficult to perform fraud such as forgery, alteration, and alteration. In particular, information that is visible cannot be said to be forgery, tampering, or alteration with a relatively simple configuration, and more advanced security technology is required.

  Therefore, the present invention has a unique color tone and color that makes it difficult to forge / modify using a specific pattern and easily determine whether it is true or false while utilizing the color shift effect of the multilayer thin film. It is an object of the present invention to provide a display that gives information that is difficult to perform fraud such as tampering and can easily determine the fact of fraud such as forgery and alteration with the naked eye. Another object of the present invention is to provide a display body applicable to a forgery prevention seal, a forgery prevention transfer foil, and the like.

The invention according to claim 1 of the present invention comprises a first laminate having an optical thin film layer provided on a first substrate with two layers of TiO ₂ having a thickness of 20 nm and SiO ₂ having a thickness of 300 nm , A second laminated body having an optical thin film layer in which TiO ₂ is provided with a thickness of 20 nm is provided on the second substrate, and the optical thin film layers of the first laminated body and the second laminated body are bonded to each other. The display body is characterized in that an optical effect function is exhibited by overlapping , and the first base material and / or the second base material transmits visible light .

The invention according to claim 2 of the present invention is the display body according to claim 1 , wherein a pattern layer is provided between layers of the first laminated body or the second laminated body.

The invention according to claim 3 of the present invention is the display body according to claim 2 , wherein the pattern layer is colorless and transparent.

The invention according to claim 4 of the present invention is the display body according to claim 2 , wherein the pattern layer is colored ink.

The invention according to claim 5 of the present invention is characterized in that an adhesive layer is provided on a surface opposite to the surface on which the optical thin film layers of the first laminated body or the second laminated body are laminated. It is a display body given in any 1 paragraph of Claims 1-4 .

  Since the present invention is configured as described above, the following effects can be obtained. That is, according to the display body of the present invention, each of the two laminates is almost colorless and transparent alone, and the color changes depending on the viewing angle only when the optical thin film layers of the two laminates are overlapped with each other. In other words, it exhibits an optical effect function in which the reflected color changes according to the change in viewing angle. In addition, an optical effect is not expressed in each laminated body simple substance.

  In addition, even if the display body of the present invention on which a character pattern is printed is copied using, for example, a color copying machine, the interference color obtained by superimposing the two laminates is that the multilayer thin film layer portion overlapping the pattern has light interference. Since the action does not occur, the reflected color does not change depending on the viewing angle, making it easy to find frauds and making such frauds difficult. Furthermore, it can be widely used in fields that require anti-counterfeiting measures such as not impairing the design of gift certificates to be affixed.

  The display body of the present invention will be described in detail below based on one embodiment.

  FIG. 1 is a plan view showing an embodiment of the display body of the present invention, and FIG. 2 is a view taken along line XX of one laminate of the display body of FIG. 1 and line YY of the other laminate. FIG. 3 is a cross-sectional view, FIG. 3 is a cross-sectional view showing an embodiment of a counterfeit prevention seal of one laminated body to which the display body of the present invention is applied, and FIGS. 4, a and b are applications of the display body of the present invention. It is a figure which shows the other Example of a forgery prevention seal.

  As shown in the cross-sectional view of FIG. 2, the laminates 1 and 2 constituting the display body of the present invention in FIG. 1 are formed by sequentially laminating substrates 11 and 12 and multilayer thin film layers 13 and 14. A pattern layer 15 is provided on the lower surface. As for the external appearance of the laminate 1 alone, visible information of characters by the pattern layer 15 is only visually observed as a normal printed matter, and at the same time, the appearance of the laminate 2 alone is a transparent film. When the laminated body 1 is stacked so that the thin film layer of the laminated body 2 is in contact with the laminated body 1, the laminated body 1 viewed through the laminated body 2 develops an interference color of light. In particular, the character information of the pattern layer 15 has a clear interference color. . The reflection / transmission characteristics change depending on the position of observation at the same time, and the effect of color shift (color change of reflected light) that appears differently appears.

  Here, the base materials 11 and 12 are preferably PET (polyethylene terephthalate), and other than that, synthetic resins such as polyvinyl chloride, polyester, polycarbonate, polymethyl methacrylate, and polystyrene, or cellulose, etc. A material such as natural resin or glass can be used as a single layer or a composite, as long as it has a certain degree of rigidity and surface smoothness. Furthermore, since the base material 12 needs to be a transparent base material that can transmit light, and the optical characteristics may be limited depending on the layer structure, depending on the use of the multilayer thin film layer to be laminated or the display body of the present invention. Are appropriately selected.

  The thin film layers 13 and 14 are formed by combining thin films having different optical characteristics, and function as a metal thin film, a ceramic thin film, or a composite thin film formed by combining them. For example, when using thin films having different refractive indexes, a thin film having a high refractive index and a thin film having a low refractive index may be combined, or a specific combination may be alternately laminated. A desired effect can be obtained by a combination thereof.

Specifically, for example, a material in which a high refractive index material having a refractive index of about 2 or more and a low refractive index material having a refractive index of about 1.5 are stacked with a predetermined film thickness. Specific ceramics include Sb ₂ O ₃ (refractive index: n = 3.0), Fe ₂ O ₃ (n = 2.7), TiO ₂ (n = 2.6), CdS (n = 2. 6), CeO ₂ (n = 2.3), ZnS (n = 2.3), PbCl ₂ (n = 2.3), CdO (n = 2.2), Sb ₂ O ₃ (n = 2. 0), WO ₃ (n = 2.0), SiO (n = 2.0), Si ₂ O ₃ (n = 2.5), In ₂ O ₃ (n = 2.0), PbO (n = 2.6), Ta ₂ O ₃ (n = 2.4), ZnO (n = 2.1), ZrO ₂ (n = 2.0), SnO (n = 2.0), ITO (n = 2) 0.0), MgO (n = 1.6), SiO ₂ (n = 1.5), MgF ₂ (n = 1.4), CeF ₃ (n = 1.6), CaF ₂ (n = 1. _{3~1.4), AlF 3 (n =} 1.6), Al 2 O 3 (n = 1.6), There is such aO (n = 1.7).

  Examples of the metal thin film or the alloy thin film include Al, Fe, Mg, Zn, Au, Ag, Cr, Ni, Ti, Cu, and Si. By selecting at least one selected from the above-described high refractive index materials or 30-60% transparent metal thin films and at least one selected from low refractive index materials, and laminating them alternately at a predetermined thickness, a specific It shows absorption or reflection of visible light at a wavelength. In addition, since the optical characteristics such as the refractive index of the thin film made of metal vary depending on the state of the constituent material and the formation conditions, values in certain conditions are used in the embodiments of the present invention.

  The thin film layer is appropriately selected from the various materials described above based on optical characteristics such as refractive index, reflectance, and transmittance, weather resistance, chemical resistance, interlayer adhesion, and the like. A known method can be used as the formation method, and it is possible to control the film thickness, film formation speed, number of layers, or optical film thickness (= n · d, n: refractive index, d: film thickness), etc. It is possible to use a physical vapor deposition method such as a vacuum deposition method or a sputtering method, or a chemical vapor deposition method such as a CVD method. Note that although only ceramics and metals are disclosed in the present invention, other materials can be used as long as they have a refractive index and reflectance equivalent to or similar to those of ceramics and metals.

As a specific example of the thin film layers 13 and 14, the thickness of each thin film is in the range of 50 to 2000 nm, and the thin film layer structure is a thin film made of the above-described high refractive index material, such as ZnS, TiO ₂ , ZrO ₂ , In ₂ O ₃ , SnO, ITO, CeO ₂ , ZnO, Ta ₂ O _{3 and the} like, and thin films made of the above-described low refractive index materials, for example, MgF ₂ , SiO ₂ , CaF ₂ , MgO, Al ₂ O A combination of ₃ and the like, which are alternately stacked, and the number of stacked layers is 2 or more, preferably 2 to 9 layers. Note that the optical characteristics of the multilayer film differ depending on the materials and combinations used, and the present invention is not limited to this. The thin film is formed on each of the thin films 13 and 14, but the thin film is separated by one layer when the optical effect is obtained with two layers.
Moreover, when the effect is obtained with three or more layers, they can be appropriately separated.

  In addition, when the base materials 11 and 12 on which the multilayer thin film layers 13 and 14 are formed are organic polymers having a low refractive index, it is desirable that the next layer in contact with the base materials 11 and 12 has a high refractive index. . In general, the spectral characteristics vary according to the number of layers. Further, although not shown in the figure, by providing a colored layer (not shown) with colored transparent ink or the like so as to be positioned on the base material 11 or the thin film layer 12, the color change becomes more diverse and easy to see. The prevention effect can be improved.

  The total thickness of the thin film layers 13 and 14 is preferably 1 μm or less. This is because if the thickness exceeds 1 μm, the flexibility is poor and cracks may occur in the thin film layers 13 and 14.

  The pattern layer 15 forms visible information such as letters, numbers, designs such as marks and pictures, and the like below the thin film layer 13. Furthermore, when there are a plurality of thin films, they may be disposed between the layers. Furthermore, visible information may be formed between two or more layers, or the visible information between the layers may be combined.

  The pattern layer 15 constituting the visible information is formed of a generally used polymer material that dissolves in water or an organic solvent, or an ink-like material in which an appropriate amount of pigment or dye is mixed. Specific examples of the polymer material include polyvinyl alcohol, methyl cellulose, ethyl cellulose, cellulose acetate, polystyrene, polyvinyl chloride, linear saturated polyester, polymethyl methacrylate, polymethyl methacrylate, and other methacrylic resins alone or copolymerized. Resin, acrylic resin, styrene resin, silicon resin, polyisobutyl resin or the like can be used. For example, the pattern layer 15 is a printing method such as a gravure printing method, an offset printing method, a screen printing method, etc., using a colorless transparent ink in which no pigment or dye is added to the polymer material, or a black ink in which a black pigment or dye is added. Or a known forming method such as a coating method such as a bar coating method, a gravure method, a roll coating method, or an ink jet method.

  The pattern layer 15 may have a color other than the colorless transparent ink and the black ink, and may include a material having absorption or reflection other than the visible light region. It can be appropriately selected depending on the use of the above.

  Next, FIG. 3 is a cross-sectional view showing an embodiment of the anti-counterfeit seal 3 of one laminated body to which the display body of the present invention is applied. The thin film layer 13 on the base material 11 and the base material 11 An adhesive layer 16 is laminated on the back surface. The laminate 2 to be combined is the same as described above. The anti-counterfeit seal 3 is bonded and fixed to an adherend through an adhesive layer 16.

  Here, the adhesive layer 16 can use a general adhesive / pressure-sensitive adhesive material. For example, vinyl chloride-vinyl acetate copolymer, polyester-based, polyamide-based, acrylic-based, butyl rubber-based, natural rubber-based, silicone-based, polyisobutyl-based adhesive materials alone, or alkyl methacrylate, vinyl ester, acrylonitrile, styrene Additives such as coagulation components such as vinyl monomers, unsaturated carboxylic acids, hydroxy group-containing monomers, acrylonitrile, and other reforming components, polymerization initiators, plasticizers, curing agents, curing accelerators, and antioxidants What was added as needed can be used. The adhesive layer 16 can be formed by a known gravure printing method, offset printing method, screen printing method, or other coating method, or a bar coating method, gravure method, roll coating method, or the like.

Next, FIG. 4 shows an application example of the laminate 2 constituting the display body of the present invention and the anti-counterfeit seal 3 which is the other laminate. As shown in FIG. 4 a, the forgery prevention seal 3 described above is attached to the surface of the individual packaging box, and the outside thereof is packaged with the laminate 2. The character pattern 15 exhibits a color shift effect according to the viewing angle by overlapping two stacked bodies. However, as shown in FIG. 4B, the color shift effect of the character pattern 15 is lost when the laminate 2 is peeled off.

  As described above, in the display body of the present invention, each of the two laminated bodies is almost colorless and transparent, and a function of changing the color depending on the viewing angle is exhibited by superimposing the two laminated bodies. Even if the display body on which the character pattern is printed is copied using, for example, a color copying machine, the interference color obtained by superimposing the two laminates is such that the interference effect of light does not occur in the multilayer thin film layer portion overlapping the pattern. In addition, the color does not change depending on the viewing angle, making it easy to find fraudulent activities and making such fraudulent activities difficult. Furthermore, it can be widely used in fields that require anti-counterfeiting measures such as not detracting from the design of gift certificates to be attached.

  Specific examples of the present invention will be described below.

<Example 1>
-Laminate 1
Using a transparent polyethylene terephthalate (PET) resin sheet with a thickness of 25 μm as a base material, and using a polyester gravure ink (trade name: NEW LP Super Toyo Ink Co., Ltd.) of yellow, cyan, magenta, and black colors on the base material. A pattern layer made of letters and the like was formed to a thickness of 1 μm by a gravure printing method. Subsequently, the thin film layer which consists of the following [Thin film layer composition 1] was formed to two layers by the vacuum evaporation method, and the laminated body 1 was obtained.
[Composition 1 of thin film layer]
Metal thin film layer (high refractive index side) TiO ₂ 20nm
Ceramic thin film layer (low refractive index side) SiO ₂ 300 nm
The base material / metal thin film layer / ceramic thin film layer / metal thin film layer / ceramic thin film layer were provided in this order.
・ Laminate 2
Using a 25 μm thick transparent polyethylene terephthalate (PET) resin sheet as a base material, a thin film layer composed of the following [thin film layer composition 2] was formed on the base material by a vacuum deposition method.
[Composition 2 of thin film layer]
Metal thin film layer TiO ₂ 20nm
When the laminated body 2 was stacked on the laminated body 1 so that the thin film layers face each other, it was confirmed that the color change of the portion on the thin film, particularly the pattern layer portion, changed from blue to reddish purple. However, the duplicates of the duplicates copied with a color copier could easily detect counterfeiting because the pattern layer portion was simply black.

<Example 2>
・ Anti-counterfeit seal 3
Using the laminate 1 produced in Example 1 described above, an adhesive layer made of an acrylic adhesive material is formed on the surface opposite to the thin film layer to a thickness of 10 μm by the gravure method, and combined with the silicon release paper. A forgery prevention seal 3 was obtained.

  The anti-counterfeit seal 3 was attached to the surface of the individual packaging box, and then the individual packaging box was packaged using the laminate 2 produced in Example 1. The entire packaged box, particularly the pattern layer portion, exhibited a color change from blue to reddish purple. However, when the laminate 2 was peeled off, the color change was lost and the product became colorless and transparent. In particular, the printed color was clearly confirmed in the pattern layer portion, and the color shift effect was almost lost. Further, even when the anti-counterfeit seal 3 was peeled off from the individual packaging box and copied with a color copying machine, the interference color was not obtained even when the copied product and the laminate 2 were overlapped. Further, when the laminate 2 was copied with a color copier and was stacked on the anti-counterfeit seal 3, no interference color was obtained.

  As described above, according to the display body of the present invention, an improper act created by copying with a color copier or the like by separating and generating a thin film designed to obtain an interference color into a plurality of base materials It has become possible to provide a counterfeit-preventing display body that counters this.

The top view which shows one Embodiment of the display body of this invention. Sectional drawing in the XX line of one laminated body of the display body of FIG. 1, and the YY line of the other laminated body. Sectional drawing which shows one Example of the forgery prevention seal of one laminated body to which the display body of this invention is applied. The figure which shows the other Example of the forgery prevention seal to which the display body of this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laminate 1 2 ... Laminate 2 3 ... Anti-counterfeit seal 11, 12 ... Base material 13, 14 ... Thin film layer 15 ... Pattern layer 16 ... Adhesive layer

Claims (5)

Two layers of TiO ₂ with a thickness of 20 nm and SiO ₂ of 300 nm are provided on the first substrate, and the first laminate having an optical thin film layer is provided. TiO ₂ is formed on the second substrate. comprises a second laminate having an optical thin film layer provided in a thickness of 20 nm, of expressing optical effect function by superimposing the optical thin film layers to each other in said first laminate and the second laminate, further The display body , wherein the first base material and / or the second base material transmits visible light . The display body according to claim 1 , further comprising a pattern layer between layers of the first stacked body or the second stacked body. The display body according to claim 2 , wherein the pattern layer is colorless and transparent. The display body according to claim 2 , wherein the pattern layer is colored ink. The adhesive layer is provided in the surface on the opposite side to the surface where the optical thin film layer of said 1st laminated body or a 2nd laminated body is laminated | stacked, The any one of Claims 1-4 characterized by the above-mentioned. Display body to be described.