JP2009107260A - Concealment image laminated body, concealment image sheet body using same, and verification method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concealment image laminated body having a covert function to visualize a latent image, wherein the laminated body is capable of being subject to printing a with a sense of design without being influenced by the concealment image (latent image), the latent image which has appeared (visualized) itself is high in design registrability, and a plurality of verification equipment can be used to verify the existence of the latent image; to provide a concealment image sheet using the laminated body; and to provide a verification method of them. <P>SOLUTION: The concealment image laminated body 10 is structured by stacking at least three layers comprising a base layer 1, a colored ink layer 2, and a latent image layer 3, wherein the three layers are stacked in the order of the base layer, the colored ink layer, and the latent image layer. The latent image layer 3 has a birefringent material patterned in two axes, and the colored ink layer contains colorants that have different spectral reflectivity in a low wavelength region of low visibility. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a concealed image laminated body that visualizes a latent image such as a hidden character or a concealed pattern for performing counterfeit prevention and authenticity determination of a product using a filter, etc., and a concealed image sheet using the concealed image It relates to those verification methods.

  Conventionally, media that are difficult to counterfeit have been affixed to prevent counterfeiting of securities. In recent years, not only securities but also counterfeiting of products has become necessary because counterfeiting of products has increased. Therefore, forgery prevention media has been affixed to products like securities. The authenticity of the product is judged through this medium.

  As a technique used for the anti-counterfeit medium, there are an overt function that can be determined visually and a covert function that cannot be determined visually and determined using a verifier. In particular, the overt function is easily countered. In recent years, attention has been paid to the covert function.

  One of the covert functions is a latent image medium using liquid crystal. An authenticity determination is performed by causing an image to appear by applying a film to a medium that is visually invisible. This is very difficult to counterfeit because very high technology is required (see, for example, Patent Document 1).

The above prior art documents are shown below.
JP 2005-091786 A

  However, since the latent image medium using the liquid crystal interferes with the latent image, it is difficult to print with design on the latent image medium, and the image appears in a place where there is no latent image. However, since the appearing image is black and white, there is a problem that it is difficult to impart design properties. Further, when this latent image medium is used as a product forgery prevention medium, there is a concern that the design by printing the package or the design of the image itself may be impaired in order to attach the latent image medium to a product package or the like. In addition, this latent image medium alone has a problem in that it is not verified with reliability only by verification using a filter.

  The present invention solves the problems of the prior art, and the problem is that in a concealed image laminate having a co-part function, printing having design characteristics without being affected by the concealed image (latent image). A hidden image that is capable of reliable and true / false judgments using multiple verifiers that are capable of image quality, and that the latent image that appears (visualized) itself is rich in design, and that verifies the presence or absence of a latent image. It is an object of the present invention to provide a laminated body, a concealed image sheet using the same, and a verification method thereof.

  In order to achieve the above-described object in the present invention, first, in the invention of claim 1, a concealed image laminate in which at least three layers of a base material layer, a colored ink layer, and a latent image layer are laminated, The hidden image laminate is characterized in that the lamination of the three layers is in the order of a colored ink layer, a base material layer, and a latent image layer.

The invention according to claim 2 is a concealed image laminate in which at least three layers of a base material layer, a colored ink layer and a latent image layer are laminated, and the lamination of the three layers is a base material layer and a colored ink layer. The hidden image layered body is characterized by the order of the latent image layers.

  The invention according to claim 3 is a concealed image laminate in which at least three layers of a base material layer, a colored ink layer, and a latent image layer are laminated, and the lamination of the three layers is a base material layer and a latent image layer. The concealed image layered body is characterized by the order of the colored ink layer.

  According to a fourth aspect of the present invention, the colored ink layer includes colored materials having different spectral reflectances in a wavelength range having low visibility, and the latent image layer is biaxially birefringent. The concealed image laminate according to any one of claims 1 to 3, which is patterned.

  According to a fifth aspect of the present invention, there is provided a concealed image single body using the concealed image laminate according to any one of the first to fourth aspects.

  The invention according to claim 6 is the concealed image laminate according to any one of claims 1 to 4 and the concealed image single body verification method according to claim 5, wherein the concealed image laminate is provided. And a hidden image layered body and a hidden image sheet body, wherein a linearly polarizing plate or a circularly polarizing plate is superimposed on the hidden image sheet, and the presence or absence of the latent image in the latent image layer is visually confirmed. It is a method.

  Further, in the invention of claim 7, the concealed image laminate according to any one of claims 1 to 4 and the concealed image single body verification method according to claim 5, wherein the concealed image laminate is provided. And a method for verifying a concealed image laminate and a concealed image sheet, wherein a film that shields a specific wavelength is superimposed on the concealed image sheet, and the presence or absence of a color change in the colored ink layer is visually confirmed. It is a thing.

  Furthermore, in the invention of claim 8, the concealed image laminate according to any one of claims 1 to 4 and the concealed image single wafer verification method according to claim 5, wherein the concealed image laminate is provided. A film that shields a specific wavelength and a linearly polarizing plate or a circularly polarizing plate are sequentially stacked on the body and the concealed image sheet, and the presence or absence of a color change in the colored ink layer and the presence or absence of a latent image in the latent image layer are visually verified. This is a method for verifying a concealed image laminate and a concealed image sheet.

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

  That is, according to the invention according to the above claims, a latent image appears by verification with a polarizer, and a color change can be confirmed by verification with a wavelength cut filter. Thus, by using a plurality of verification methods, verification can be performed. The latent image layer and the colored ink layer constituting the hidden image laminate or the hidden image sheet can contribute to the improvement of forgery prevention. In addition, even if design printing is performed on these layers, the latent image layer and the colored ink layer do not get in the way, and there are also color changes due to the colored ink layer. A concealed image laminate that does not spoil and a concealed image sheet using the concealed image stack. Furthermore, when this concealed image laminate is copied, the colored ink layer portion is copied black, so that counterfeiting is prevented.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  1 to 3 are explanatory views showing one embodiment of the hidden image laminate 10 of the present invention in a side sectional view.

  A transparent substrate is used as the substrate layer 1 in FIGS. For example, a plastic film produced by stretching can be used. There are uniaxially stretched and biaxially stretched films depending on how to stretch. These include cellophane, polycarbonate (PC), polyethylene (PE), polyolefins such as polypropylene (PP), ethylene vinyl alcohol (EVOH), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polyethylene naphthalate (PEN). , Polyethylene terephthalate (PET), nylon, acrylic resin, triacetyl cellulose (TAC) film, and the like.

  The colored ink layer 2 shown in FIGS. 1 to 3 includes yellow (Y), magenta (M), cyan (C), black (Bk), or a color produced by combining them, and a special that cannot be reproduced by multiplying YMCBk. Ink or the like can be used.

  Further, a metameric pair ink can be used for the colored ink layer 2. This is an ink characterized in that it contains colored materials having different spectral reflectances in a wavelength range with low visibility. For example, if the ink has a maximum value of green in the visible region and has a spectral reflectance higher than that of the aforementioned green in the infrared region having a low visibility of 650 nm or more, this is 640 nm or less. When viewed through a filter that cuts off the wavelength range, a phenomenon occurs in which it looks red.

  A liquid crystal material having birefringence can be used for the latent image layer 3 in FIGS. Birefringence means that the refractive index of a substance varies depending on the direction of the optical axis, and therefore the speed of light varies when passing through the substance. Therefore, a phase difference is generated in the light after passing through the substance by the difference in the passing speed.

  As the liquid crystal material, for example, a liquid crystal material that is solid at the use temperature of the concealed image laminate and exhibits a nematic phase or a smectic phase, typically a polymer liquid crystal material can be used. Alternatively, a latent image layer in which the alignment of mesogenic groups of liquid crystal molecules is aligned can be obtained by forming a thin film pattern made of a low molecular weight liquid crystal material in an alignment film and causing polymerization of the liquid crystal material. The alignment film is obtained, for example, by forming a resin layer such as polyimide and performing an alignment treatment such as rubbing on the resin layer. The orientation process is performed in two directions.

  In order to visualize the latent image of the latent image layer 3, a linearly polarizing plate or a circularly polarizing plate is used as a verifier. The latent image appears in a pattern oriented in two directions when a linearly polarizing plate or a circularly polarizing plate is overlaid. When the linear polarizing plate is rotated, the brightness of the latent image is reversed. Further, even if the right circularly polarizing plate is changed to the left circularly polarizing plate, the contrast of the latent image is reversed.

  In addition, when a pattern is formed on the colored ink layer 2 using a metameric pair ink, the spectral reflectance has a maximum value in a wavelength range with high visibility and a maximum in a wavelength range with low visibility. Since it contains a colorant having a spectral reflectance higher than the value, the part printed with the metameric pair ink changes to red or purple through a filter that blocks the wavelength range with high visibility. That is confirmed.

  In addition, when the colored ink layer 2 is a metameric ink, it is printed black when copied by a color copier. In this way, it is possible to prevent the concealed image laminate from being copied by the color copier, and at the same time to perform authenticity determination.

A concealed image laminate 10 using a metameric pair ink for the colored ink layer 2 is a verifier 15 comprising a filter 4 and a linearly polarizing plate or a circularly polarizing plate 5 for blocking a specific wavelength as shown in FIG.
Can be used to simultaneously confirm the presence and color change of the latent image.

  As described below, the hidden image laminate of the present invention is used as various types of hidden image sheets. As one form, for example, as shown in the side sectional view of FIG. 5, there is an adhesive label 20, which has a structure in which a sheet-like support 22, a hidden image laminate 10, and an adhesive 24 are sequentially laminated. Yes. However, the sheet-like support 22 is desirably a film having no optical anisotropy. For example, when a stretched film is used, it is not preferable because a latent image is difficult to see or reversal of light and darkness cannot be confirmed. Moreover, since the base material layer is included in the concealed image laminate 10, for example, the base material layer 1 may be used as a support as shown in FIGS. 1 and 2, and the adhesive 24 may be provided on the opposite side. .

  For example, the adhesive label 20 is attached to an article whose authenticity is to be confirmed, or is attached to another article such as a tag attached to the article. Therefore, the authenticity of the article can be confirmed by the method described above.

  Such a brittle adhesive label 20 is obtained, for example, by forming a notch or a perforation in the hidden image laminate 10. When the adhesive label is brittle, the hidden image laminate 10 is easily destroyed when the adhesive label 20 attached to the article whose authenticity is to be confirmed is peeled off. Therefore, it is difficult to replace the adhesive label 20.

  In addition, as another example of the concealed image sheet of the present invention, for example, as shown in the side sectional view of FIG. 5, there is a transfer foil 30, which includes at least a sheet-like support 32, The transfer layer 36 composed of the hidden image laminate 10 and the adhesive 34 is sequentially laminated. At least the transfer layer 36 constituted by the hidden image laminate 10 is peeled off from the support 32 and transferred. It can be transferred to a body (not shown).

  Such a transfer foil 30 is transferred to an article whose authenticity is to be confirmed, for example. The article to be transferred includes, for example, an authentication medium such as a cash card, a credit card and a passport, or a paper for a securities medium such as a gift certificate and a stock certificate. Even in such a case, the authenticity of the article can be confirmed by the verification method as described above.

  Hereinafter, specific examples of the present invention will be described.

<Example 1>
As a base material of the base material layer, a polyimide film was formed by a gravure coating method on polarized light scattering PET (manufactured by Teijin Limited) in which divinylbenzene crosslinked fine particles (refractive index of about 1.57) were dispersed as a filler. This was rubbed to obtain an alignment film. A cross-linked liquid crystal monomer was formed on the alignment film obtained here by a gravure coating method, and after heating, the liquid crystal was cured by irradiation with ultraviolet rays in a nitrogen atmosphere.

  Next, printing was performed on the back surface of the surface having the alignment film and the liquid crystal layer with a metameric pair ink. This metameric pair ink has a maximum value of green in the visible light region, and has a spectral reflectance higher than that of green in the infrared region having a low visibility of 650 nm or more. Further, an adhesive layer was formed on the metameric pair ink to obtain an adhesive label.

  Next, this adhesive label was affixed on the base material. This was observed through a right circularly polarizing plate. As a result, a bright and dark image appeared. Moreover, when observed through the left circularly polarizing plate, the brightness of the black and white image that appeared earlier was reversed. In addition, when visually observed through a filter that cuts off a wavelength region of 640 nm or less, the portion printed with the metameric pair ink turned red.

  Next, the adhesive label was visually observed through the filter which piled up the filter which interrupts | blocks a circularly-polarizing plate and the wavelength range below 640 nm. As a result, the latent image and the metameric pair ink were visually confirmed in red.

  When this adhesive label was copied with a color copier, the green portion printed with the metameric pair ink was copied to black.

It is explanatory drawing which represented one Embodiment of the concealment image laminated body of this invention with the side cross section. It is explanatory drawing which represented other embodiment of the concealment image laminated body of this invention by the side cross section. It is explanatory drawing which represented other embodiment of the concealment image laminated body of this invention by the side cross section. It is a schematic diagram which shows an example of the verification device which verifies the concealment image laminated body of this invention. It is explanatory drawing which represented the example of the concealment image piece body of this invention with the side cross section. It is explanatory drawing which represented another example of the concealment image piece body of this invention in the side cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base material layer 2 ... Colored ink layer 3 ... Latent image layer 4 ... Film which shields specific wavelength 5 ... Linear polarizing plate or circularly polarizing plate 15 ... Verifier 20 ... Adhesive label 22 ... ... Sheet-like support 24 ... Adhesive 30 ... Transfer foil 32 ... Sheet-like support 34 ... Adhesive 36 ... Transfer layer

Claims (8)

  It is a concealed image laminate in which at least three layers of a substrate layer, a colored ink layer, and a latent image layer are laminated, and the lamination of the three layers is in the order of the colored ink layer, the substrate layer, and the latent image layer. A hidden image laminate characterized by the above.   It is a concealed image laminate in which at least three layers of a substrate layer, a colored ink layer, and a latent image layer are laminated, and the lamination of the three layers is in the order of the substrate layer, the colored ink layer, and the latent image layer. A hidden image laminate characterized by the above.   A concealed image laminate in which at least three layers of a base material layer, a colored ink layer, and a latent image layer are laminated, and the lamination of the three layers is in the order of the base material layer, the latent image layer, and the colored ink layer. A hidden image laminate characterized by the above.   The colored ink layer includes colored materials having different spectral reflectances in a wavelength range having low visibility, and the latent image layer is patterned biaxially with a birefringent material. The concealed image laminate according to any one of claims 1 to 3.   A concealed image single-piece body using the concealed image laminate according to any one of claims 1 to 4.   The method for verifying a concealed image laminate according to any one of claims 1 to 4 and the concealed image single piece according to claim 5, wherein linearly polarized light is applied to the concealed image laminate and the concealed image single piece. A method for verifying a concealed image laminate and a concealed image sheet, comprising: stacking a plate or a circularly polarizing plate and visually verifying whether or not a latent image appears in a latent image layer.   The method for verifying a concealed image laminate according to any one of claims 1 to 4 and the concealed image single piece according to claim 5, wherein the concealed image laminate and the concealed image single piece are specified for the concealed image laminate and the concealed image single piece. A method for verifying a concealed image laminate and a concealed image sheet, comprising: overlapping a film that shields wavelengths; and visually verifying whether or not a colored ink layer has a color change.   The method for verifying a concealed image laminate according to any one of claims 1 to 4 and the concealed image single piece according to claim 5, wherein the concealed image laminate and the concealed image single piece are specified for the concealed image laminate and the concealed image single piece. A concealed image laminate comprising: a film that shields a wavelength; and a linearly polarizing plate or a circularly polarizing plate that are sequentially overlapped, and the presence or absence of a color change in a colored ink layer and the presence or absence of a latent image in a latent image layer are visually verified. A method for verifying a hidden image piece.

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