JP2014104640A - Antifalsifying medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide configuration for complicating falsifying in an antifalsifying medium having a changing effect which is an antifalsifying technique capable of determining whether an object is a real thing or an imitation without using a detection device or a detection medium.SOLUTION: The thin film laminate which shows multipath reflection of light is granulated into fine particles and dispersed in a vehicle to form an ink. The ink is formed on a base material. On the base material, an adhesive layer, a reflection layer which has a dot-like or stripe-like pattern, a hologram or a grating which is a surface relief shape are provided in this order.

Description

  The present invention is used as a counter measure against counterfeiting of banknotes, claims, gift certificates, checks such as cash vouchers, securities, various certificates such as credit cards, ID cards, and official documents, important documents, and even branded goods and luxury goods. In particular, the present invention relates to an anti-counterfeit medium that has a changing effect that cannot be reproduced by a copy or a scanner and that can be determined by visual inspection only.

  As a measure against imitations of printed materials such as securities, various certificates and important documents, branded products and luxury products, a forgery prevention medium is affixed to the product to guarantee or prove its value. For that purpose, it is necessary to apply a high security forgery prevention technology.

  Anti-counterfeiting technology is required that anyone can recognize it as anti-counterfeiting technology and enable authenticity determination, and includes anti-counterfeiting effects such as diffraction structures and multilayer interference films that change color and pattern depending on the viewing angle. In order to further improve the above, these are often combined with each other to produce a product.

  A hologram is a technology that records the direction and intensity of light in the form of interference fringes on a planar material, and is characterized by stereoscopic display with parallax and brightness that is impossible with general printing. Holograms are also fully digitized using precision electronics technology.

  OVD (Optical Variable Device) like multilayer thin film that changes color depending on viewing angle by superimposing holograms and diffraction gratings that can express stereoscopic images and special decorative images using light interference, and thin films with different optical characteristics ) Is continuously increasing. It is still difficult to easily forge a fine image expression, and it is still representative of anti-counterfeiting technology. (Patent Document 1).

  In addition, as a forgery prevention technology that combines the latent image technology using the birefringence of the liquid crystal material and the interference image of light such as holograms, only a holographic image can be visually observed, and the latent image can be seen through a polarizing plate. A latent image medium having an OVD layer that can confirm the above has been proposed (Patent Document 2).

  However, although authenticity can be determined by using a medium such as a polarizing plate or by machine reading, it is not easy to distinguish between genuine products and counterfeit products only by visual observation, which is insufficient as a forgery prevention technique.

  In the conventional hologram, the changing function with the structure as described above is used as a point of authenticity determination, but the two types of images in the changing function are both based on the same principle, and a duplicate of one image If it is possible, the other can be duplicated at the same time.

JP 2004-222877 A JP 2001-63300 A

The present invention has been made in view of the above circumstances, and makes it difficult to counterfeit an anti-counterfeit medium having a changing effect that is an anti-counterfeit technique capable of determining authenticity without using a detection device and a detection medium. It is in providing the structure for.

  As means for solving the above-mentioned problems, the invention according to claim 1 is characterized in that a thin film laminate exhibiting a multiple reflection phenomenon of light is pulverized and ink dispersed in a vehicle is formed on a substrate. The anti-counterfeit medium is characterized in that an adhesive layer, a dot-shaped or stripe-shaped reflective layer, a surface relief type hologram or a diffraction grating are provided in this order.

  According to a second aspect of the present invention, the area of the reflective layer provided in the dot shape or stripe shape is 10% to 80% of the area of the hologram and diffraction grating. Is a forgery prevention medium.

  The invention according to claim 3 is the anti-counterfeit medium according to claim 1 or 2, wherein the dot has a diameter of 5 μm to 500 μm.

  The invention according to claim 4 is the forgery prevention medium according to claim 1 or 2, wherein the stripe has a line width of 5 μm to 500 μm.

  The invention described in claim 5 is characterized in that the thin film laminate exhibiting the multiple reflection phenomenon of light is pulverized and the ink dispersed in the vehicle is pearl ink. The forgery prevention medium according to one item.

  The invention described in claim 6 is characterized in that the thin film laminate exhibiting the multiple reflection phenomenon of light is pulverized and the ink dispersed in the vehicle is OVD ink. The forgery prevention medium according to one item.

  The two types of changing effects in the present invention are anti-counterfeit technologies that can determine authenticity without using a detection device, and are devices that have two types of changing effects that are completely different in principle. In this case, it is necessary not only to copy one changing image, but also to copy images having two different principles at the same time, which raises the forgery hurdle and consequently makes it difficult to reproduce the changing effect.

It is the conceptual diagram which showed the changing effect which the forgery prevention medium of this invention has. It is the conceptual diagram which showed the process of providing a reflective layer in the shape of a dot or stripe on the relief surface of a hologram or a diffraction grating so that special ink may be observed in the forgery prevention medium of this invention. It is the conceptual diagram which showed the changing effect of a hologram. It is the conceptual diagram which showed the changing effect of special ink.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 shows the structure and changing effect of an anti-counterfeit medium according to the present invention. The anti-counterfeit medium is printed on a base material 4 using special ink 1, and a surface relief type hologram or diffraction grating is formed thereon. The formed embossed layer 3 is provided, and the reflective layer (aluminum) 2 is further provided in a dot shape or a stripe shape.

  Holograms and diffraction gratings can generate diffracted light at an arbitrary angle by controlling the spatial frequency and the grating angle.

  The special ink 1 that emits reflected light only at a specific angle includes a pearl ink that shines lightly at a viewing angle and changes its color, and an OVD ink that changes its color depending on the angle. The pearl luster of the pearl pigment is caused by the multiple reflection phenomenon of light in the thin film laminate, and is an optical interference thin film in which mica is used as a core and titanium oxide is coated on the surface layer of mica. Pearl ink made by dispersing pearl pigments in a vehicle has a soft pearly hue and pearly shine, and gives a silky soft pearly luster that is very difficult to reproduce by color copy etc. It is done.

  In addition, OVD (Optical Variable Device) expresses a stereoscopic image or a special decoration image using light interference, and changes in color depending on the viewing angle like a multilayer thin film in which thin films having different optical characteristics are stacked ( Color shift), an optical interference thin film in which an aluminum dielectric layer is used as a core, an electromagnetic dielectric layer (transparent ceramic) is provided on the front and back, and a metal layer of a half mirror is provided thereon.

  A special ink 1 such as a pearl ink or an OVD ink that generates reflected light at an arbitrary angle is provided on the substrate 4. On top of that, a surface relief type hologram and an emboss layer 3 to be a diffraction grating designed to generate diffracted light at an angle different from the angle at which the reflected light of the special ink 1 is generated are provided.

  Furthermore, as the reflective layer 2, for example, a metal layer made of a metal material such as aluminum, silver, gold, and alloys thereof can be used. Alternatively, a dielectric layer having a refractive index different from that of the embossed layer may be used as the reflective layer. Alternatively, a laminated body of dielectric layers having different refractive indexes between adjacent ones, that is, a dielectric multilayer film may be used as the reflective layer. Of the dielectric layers included in the dielectric multilayer film, the refractive index of those in contact with the embossed layer is preferably different from the refractive index of the embossed layer. The reflective layer can be formed by, for example, a vapor deposition method such as a vacuum evaporation method or a sputtering method. As a specific embodiment of the present invention, an aluminum thin film is provided in the reflective layer by vacuum forming. Thereafter, the reflective layer 2 made of an aluminum vapor deposition film is partially removed. The removal shape is, for example, a dot shape or a stripe shape, and the area to be removed is selected based on the balance between the intensity of the reflected light and the diffracted light of the ink. Since the diffracted light of the hologram is stronger than the reflected light of the special ink 1, for example, the aluminum vapor deposition film is 10% to 80% of the whole.

  The diameter of the dot and the line width of the stripe affect the appearance of the underlying special ink, but there are also workability problems, and the dot diameter is preferably 5 μm to 500 μm and the stripe line width is preferably 5 μm to 500 μm.

  In addition to the method of sequentially laminating a surface relief type hologram and diffraction grating consisting of an adhesive layer, a reflective layer and an embossed layer on the special ink 1, a hologram foil and a diffraction grating foil are prepared in advance, It can also be provided.

  FIG. 2 shows a process of forming the reflective layer 2 in the form of dots or stripes provided on the special ink, the surface relief type hologram or the diffraction grating, which is a process for producing a forgery prevention medium according to the present invention. The special ink 1 is laminated on the substrate 4. At this time, the special ink 1 is provided in a pattern by a printing method.

As the embossing layer 3 provided on the special ink 1, a thermoplastic resin, a thermosetting resin, an ultraviolet ray, an electron beam curable resin, or the like can be used. For example, acrylic resins include acrylic resins, epoxy resins, cellulose resins, vinyl resins, and the like. 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. Further, as the ultraviolet ray or electron beam curable resin, epoxy (meth) acryl, urethane (meth) acrylate, or the like can be used.

  A surface relief type hologram or diffraction grating is embossed on the embossed layer 3. In order to form a surface relief type hologram or diffraction grating on the surface of the embossed layer 3, the embossed plate is superimposed on the embossed layer 3, heated and pressurized under the conditions of 90 to 150 ° C., and then cooled. To form. At this time, the surface relief type hologram or the diffracted light of the diffraction grating is generated at an angle different from the angle at which the reflected light of the special ink 1 is generated.

  Subsequently, an aluminum layer is provided as the reflective layer 2 by vacuum vapor deposition, and a resist ink having corrosion resistance is printed so as to form a dot shape or a stripe shape, soaked in an alkaline solution, and a non-resist portion is partially covered. To remove. The part from which the aluminum has been removed becomes transparent, and the substrate can be confirmed.

  A surface relief hologram or diffraction grating is produced by the above-described process, and a foil is preferably provided by thermal transfer or the like.

  As special ink 1, a pearl ink produced by dispersing a pearl pigment (manufactured by Merck) (having a characteristic of generating reflected light at an angle of 30 degrees with respect to incident light from the front) in a vehicle was printed on a substrate. .

  The aluminum in the hologram foil takes a halftone dot, a stripe, or an arbitrary shape. However, in order to make both the hologram image and the ink image in the lower layer visible, it is desirable that the ratio of the aluminum vapor deposition portion is in the range of 10% to 80%, and the area to be removed is the reflected light and diffracted light of the ink. Although it selects from balance of each intensity | strength, since the diffraction light of a hologram is stronger than the reflected light of an ink, the aluminum vapor deposition part was 30% of the whole.

  As a result, the diffraction light of the diffraction grating on the aluminum vapor deposition layer can be confirmed at an angle of 60 degrees, and the reflected light of the ink can be confirmed through the part where the aluminum on the film is removed and becomes transparent at an angle of 30 degrees. did it. By the above means, the changing effect by two kinds of images having different principles can be realized.

  As the special ink 1, an OVD ink prepared by dispersing a OVD pigment manufactured by Flex Co., Ltd. in a vehicle was printed on a substrate, and the subsequent steps were the same as those in Example 1.

  By providing two regions that generate diffracted light at different angles in the same plane, it was possible to obtain a changing effect in which the image changes when the viewing angle is changed.

  Using a device that emits diffracted light or reflected light at an arbitrary angle, both the diffraction grating structure of the hologram and the principle of special ink were different, and an image changing effect was obtained.

1 ... Special ink 2 ... Reflective layer (aluminum)
3 ... Embossed layer 4 ... Base material 5 ... Resist layer 6 ... Adhesive layer

Claims (6)

  A thin film laminate that exhibits multiple reflection of light is pulverized, and ink dispersed in a vehicle is formed on a substrate, on which an adhesive layer, dot-like or stripe-like reflective layer, surface relief hologram or diffraction An anti-counterfeit medium characterized by sequentially providing a lattice.   The forgery prevention medium according to claim 1, wherein an area of the reflective layer provided in the dot shape or the stripe shape is 10% to 80% of the area of the hologram and the diffraction grating.   The forgery prevention medium according to claim 1 or 2, wherein the diameter of the dot is 5 m to 500 m.   The forgery prevention medium according to claim 1, wherein the stripe has a line width of 5 μm to 500 μm.   The forgery prevention medium according to any one of claims 1 to 4, wherein the thin film laminate exhibiting the multiple reflection phenomenon of light is pulverized and the ink dispersed in the vehicle is a pearl ink.   The forgery prevention medium according to any one of claims 1 to 4, wherein the thin film laminate exhibiting the multiple reflection phenomenon of light is pulverized and the ink dispersed in the vehicle is OVD ink.