JP2006293729A - Medium for authentication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium for authentication with high performance for assuring authenticity having a simple layer structure wherein authentication information is camouflaged. <P>SOLUTION: The medium has a lamination structure in which a light selective reflection pattern layer 3 composed of a cholesteric liquid crystal layer and an authentication pattern layer 4 are stacked on a transparent substrate 2. Hologram layers may be interposed between the light selective reflection pattern layer 3 and the authentication pattern layer 4, or an adhesive layer may be prepared at the lowermost layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention preferably relates to an authentication medium having individual authentication information and having a high ability to guarantee authenticity.

  Cards, labels, tags (tags), etc. are used when attempting to check the authenticity of individuals or the authenticity of goods, and authentication information such as letters or numbers according to the subject is given. There are many.

  However, if the authentication information is simply printed on a card, a label, a tag (tag), or the like, the authentication information is not concealed, so that the authentication information may be read and misused. Therefore, an attempt was made to conceal the authentication information by sticking an adhesive sheet on the printed authentication information or by laminating a scratch layer that can be scraped off with a coin or the like, but in the former case, the adhesive sheet may be peeled off. It is easy, and in the latter case, removal of the scratch layer is not so difficult, so it is not perfect, and it is troublesome to peel off the adhesive sheet or scrape off the scratch layer when viewed by a person with a legitimate authority It is.

On the other hand, instead of applying authentication information, there is an attempt to cover with a layer having other visual effects and camouflage the presence of the authentication information. For example, a background pattern printing layer is covered with a cholesteric liquid crystal layer and complicated. A transfer foil for authenticity determination that provides an appearance has been proposed. (Patent Document 1).
JP 2004-50596 A

  However, in the invention described in Patent Document 1, at least two layers of a tint block printing layer and a cholesteric liquid crystal layer are required in order to camouflage authentication information and give a complicated appearance. It has been difficult to camouflage information and give a complex appearance.

  Therefore, in the present invention, in the above prior art, at least two layers of the tint block print layer and the cholesteric liquid crystal layer are required to camouflage the authentication information to give a complicated appearance. It is an object to give a medium.

  By inventor's investigation, in order to camouflage authentication information and give a complicated appearance, by using a cholesteric liquid crystal pattern layer patterned with a cholesteric liquid crystal layer, it is possible to use both a tint block print layer and a cholesteric liquid crystal layer. It was found that the problem could be solved.

  According to a first aspect of the present invention, there is provided at least two of an authentication pattern layer and a light selective reflection pattern layer made of a layer of a material having light selective reflectivity that reflects either left circularly polarized light or right circularly polarized light in incident light. The present invention relates to an authentication medium having a laminated structure in which layers are laminated.

  A second invention relates to the authentication medium according to the first invention, wherein the light selective reflection pattern layer is laminated on at least one surface of a transparent substrate.

  A third invention relates to an authentication medium according to the first or second invention, wherein the light selective reflection pattern layer is made of a cholesteric liquid crystal.

  A fourth invention relates to the authentication medium according to any one of the first to third inventions, wherein the pattern of the authentication pattern layer has the same color as the light selective reflection pattern layer or an approximate color. Is.

  5th invention is either 1st-4th invention, the said authentication pattern layer side or the said light selective reflection pattern layer of the laminated structure by which the said authentication pattern layer and the said light selective reflection pattern layer were laminated | stacked The present invention relates to an authentication medium characterized in that a hologram layer is laminated on the side.

  According to a sixth invention, in any one of the first to fifth inventions, an adhesive layer is laminated on either the front or back of the laminated structure in which the authentication pattern layer, the light selective reflection pattern layer, and the hologram layer are laminated. It is related with the medium for authentication characterized by being characterized.

  According to the first aspect of the present invention, it is possible to provide an authentication medium in which the pattern of the authentication pattern layer is camouflaged by superimposing only the light selective reflection pattern layer on the authentication pattern layer as compared with the conventional technique.

  According to the second invention, in addition to the effects of the first invention, since the light selective reflection pattern layer is laminated on the transparent substrate, the authentication medium is easy to manufacture and easy to apply to the object. Can be provided.

  According to the third aspect of the invention, it is possible to provide an authentication medium in which the light selective reflection pattern layer is formed using a specific easy-to-use material.

  According to the fourth invention, in addition to the effects of any one of the first to third inventions, the color of the pattern of the authentication pattern layer is the same as or similar to the color of the light selective reflection pattern layer. It is possible to provide an authentication medium having a higher effect of camouflaging the authentication pattern layer.

  According to the fifth invention, in addition to the effects of any one of the first to third inventions, the three-dimensional image and interference color provided by the hologram layer are added, so the effect of camouflaging the pattern of the authentication pattern pattern layer Can be provided.

  According to the sixth invention, in addition to the effects of any one of the first to fifth inventions, an authentication medium that can be easily applied to a target article is provided by further applying an adhesive layer. can do.

  FIG. 1 is a diagram showing a basic laminated structure of an authentication medium of the present invention, and FIG. 2 is a preferred embodiment of the authentication medium of the present invention. It is a figure which shows the state laminated | stacked. In any figure, it is assumed to observe from the upper side of the figure.

  As shown to Fig.1 (a), the authentication medium 1 of this invention is laminated | stacked on the one side of the transparent base material 2, for example, the light selective reflection pattern layer 3 and the authentication pattern layer 4 in order of description. . In the example of FIG. 1 (b), the authentication medium 1 of the present invention has a light selective reflection pattern layer 3 laminated on the upper side of the transparent substrate 2, and a light selective reflection pattern layer 3 of the transparent substrate 2 laminated. The authentication pattern layer 4 is laminated on the opposite side to that formed.

  In the example shown in FIGS. 1 (a) and 1 (b), the transparent substrate 2 is preferably present in forming the light selective reflection pattern layer 2 and the authentication pattern layer 3, but one pattern is present. Alternatively, since both patterns can be peeled off after forming both patterns, the authentication medium 1 may not be accompanied by the transparent substrate 2.

  In the example shown in FIGS. 1A and 1B, the light selective reflection pattern layer 2 and the authentication pattern layer 3 may be formed by connecting patterns constituting each pattern layer. A group of points that are separated from each other can be used. In either case, it will be called a “layer” for convenience.

  As the transparent substrate 2 described above, it is possible to reduce the thickness, and it is preferable to have a solvent resistance and a heat resistance that can withstand mechanical strength and processing when the authentication medium 1 is manufactured. Since it depends on the purpose of use, it is not necessarily limited, but a film-like or sheet-like plastic is preferable. For example, various plastic films such as polyethylene terephthalate (PET), polycarbonate, polyvinyl alcohol, polysulfone, polyethylene, polypropylene, polystyrene, polyarylate, triacetyl cellulose (TAC), diacetyl cellulose, and polyethylene / vinyl alcohol can be exemplified. .

  The light selective reflection pattern layer 3 is composed of a cholesteric liquid crystal layer. The cholesteric liquid crystal layer in the aligned state has a property of reflecting only one of left circularly polarized light and right circularly polarized light in incident light. The light selective reflection pattern layer 4 can be formed by applying a solvent solution of cholesteric liquid crystal in a pattern and drying it. Alternatively, at this time, an ultraviolet polymerizable composition is prepared using a polymerizable cholesteric liquid crystal. It can be used as a pattern, and after drying, it can be formed by irradiating with ultraviolet rays for polymerization.

  In order to form the light selective reflection pattern layer 4 in a pattern, it is preferable to use various printing methods. When two or more light selective reflection pattern layers 4 are provided, at least one of them is uniform. In order to form a uniform layer, it is preferable to use various coating methods.

  The light selective reflection pattern layer 3 may basically have any pattern. Since it is preferable that the pattern of the authentication pattern layer 4 on the lower layer side can be camouflaged, from this point of view, the pattern, size, pattern shape, pattern arrangement pitch, etc. of the authentication pattern layer 4 are similar. Are preferred.

  In order to bring the cholesteric liquid crystal layer of the light selective reflection pattern layer 3 into an oriented state, it is preferable that the surface of the transparent substrate 2 on the side where the light selective reflection pattern layer 3 is laminated has orientation. When the stretched plastic sheet is used as the transparent base material 2, the surface of the transparent base material 2 originally has orientation and may be left as it is. In the case where there is no orientation on the surface of the transparent substrate 2, it is preferable to laminate an orientation film for imparting orientation.

  The alignment film can be composed of any material as long as it can be generally used as an alignment film, such as polyvinyl alcohol resin (PVA) or polyimide resin. The alignment film is prepared by applying a solvent solution of these resins to the surface of the transparent substrate 2 on the side where the light selective reflection pattern layer 3 is laminated by an appropriate application method and drying, and then applying a cloth, a brush, or the like. It is formed by rubbing using it. When two or more light selective reflection pattern layers 3 are provided, an alignment film provided as necessary between the light selective reflection pattern layers 3 can be formed in the same manner.

  The authentication pattern layer 4 is formed by using means and materials that are usually used when applying characters, figures, etc. to an object. Examples of the material include a colorant composed of a dye or a pigment, And a binder resin or the like.

  The pattern of the authentication pattern layer 4 is composed of letters, numbers, figures or symbols, or any combination thereof. The pattern of the authentication pattern layer 4 may be visually identifiable, but may be machine-readable, and may be machine-readable such as a barcode or QR code (two-dimensional barcode). There may be.

  In order to sufficiently camouflage the pattern of the authentication pattern layer 4 with the pattern of the light selective reflection pattern layer 3, it is preferable that the patterns of both pattern layers are the same or have similar colors. Although the hue of the light selective reflection pattern layer 3 varies depending on the viewing angle, it basically depends on the helical pitch of the cholesteric liquid crystal layer constituting the light selective reflection pattern layer 3 and the thickness of the layer. Therefore, the composition and thickness of the cholesteric liquid crystal may be determined, and the hue of the pattern of the authentication pattern layer 4 may be determined using an ink or toner that gives a hue corresponding to the composition and thickness.

When the authentication medium 1 of the present invention having the above configuration is arranged and observed so that the light selective reflection pattern layer 3 is closer to the observation side than the authentication pattern layer 4, the light selective reflection layer 3 is temporarily formed in a right circle. In the case of reflecting only polarized light, the pattern of the light selective reflection layer 3 appears to change color depending on the viewing angle or by entering the right circularly polarized light, and the pattern of the lower authentication pattern layer 4 is changed. Camouflaged and difficult to see. On the other hand, when the pattern of the authentication pattern layer 4 is composed of normal ink or toner, if the viewing angle is selected so that the pattern of the light selective reflection pattern layer 3 is most difficult to see, the authentication pattern layer 4 The pattern of the pattern layer 3 can be easily observed.
Alternatively, the pattern of the authentication pattern layer 4 may be configured as a magnetic pattern instead of a visual or optical pattern. In this case, depending on how the light selective reflection pattern layer 3 is viewed. Regardless, magnetic reading can be enabled.

The authentication medium 1 of the present invention preferably takes a form suitable for application to the target article, depending on the target article. In the case of the card mentioned in the description of the background art, it is preferable that the card has a size and a thickness suitable for a deposit and saving card used in a financial institution. In the case of a label, it is preferable that an adhesive layer, preferably a pressure-sensitive adhesive layer, is applied in advance to the surface on the target article side so that it can be easily attached to the target article. In the case of a tag (hanging tag) or the like, it is preferable that a hanging string, a wire, or the like is attached using a hole opened in the authentication medium 1.
The case where the authentication medium 1 of the present invention is used as a label, including preferable elements that can be added, will be described with reference to the following paragraph.

  In the example shown in FIG. 2, from the upper side of the figure, for authentication, the transparent substrate 2, the light selective reflection pattern layer 3, the hologram forming layer 5A, the hologram reflection layer 5B, the authentication pattern layer 4, and the adhesive layer 6 are used. The medium 1 is shown in a state where the medium 1 is stuck on the adherend 7 so that the adhesive layer 6 side is in contact with the adherend 7. Among the layers, the transparent substrate 2, the light selective reflection pattern layer 3, and the authentication pattern layer 4 are cited with reference to FIG. 1 except that the authentication pattern layer 4 is in contact with the hologram reflection layer 5B. Same as described.

  The hologram forming layer 5A has a relief hologram with fine irregularities formed on the lower surface side in the figure, and the layer itself is made of a transparent resin. The hologram reflection layer 5B is for increasing the visibility of the hologram. The laminated structure of the hologram forming layer 5A and the hologram reflecting layer 5B is also referred to as a hologram layer.

  Examples of the transparent resin for constituting the hologram forming layer 5A include various thermoplastic resins, thermosetting resins, and ionizing radiation curable resins. Thermoplastic resins include acrylic ester resins, acrylamide resins, nitrocellulose resins, or polystyrene resins. Thermosetting resins include unsaturated polyester resins, acrylic urethane resins, epoxy-modified acrylic resins, and epoxy-modified unsaturated resins. A polyester resin, an alkyd resin, a phenol resin, etc. are mentioned. These thermoplastic resins and thermosetting resins can be used alone or in combination of two or more. One or more of these resins may be cross-linked using various isocyanate resins, or various curing catalysts, for example, metal soap such as cobalt naphthenate or zinc naphthenate may be blended. Or peroxide such as benzoyl peroxide and methyl ethyl ketone peroxide for initiating polymerization with heat or ultraviolet light, benzophenone, acetophenone, anthraquinone, naphthoquinone, azobisisobutyronitrile, or diphenyl sulfide good. Examples of the ionizing radiation curable resin include epoxy acrylate, urethane acrylate, acrylic-modified polyester, etc., for the purpose of introducing a crosslinked structure into such an ionizing radiation curable resin or adjusting the viscosity, A monofunctional monomer, a polyfunctional monomer, or an oligomer may be blended and used.

  In order to form the hologram forming layer 5A using the above resin, it can be directly formed by developing the photosensitive resin material by performing interference exposure of the hologram. It is preferable to perform molding by using a product or a plating mold thereof as a replication mold and pressing the mold surface against the layer of the resin material. When thermosetting resin or ionizing radiation curable resin is used, curing is performed by heating or ionizing radiation irradiation while keeping the uncured resin in close contact with the mold surface, and then cured by peeling after curing. The fine irregularities of the relief hologram can be formed on one side of the layer made of a transparent resin material. A diffraction grating forming layer having a diffraction grating formed in a pattern by a similar method can also be used as the optical diffraction structure.

  The hologram reflection layer 5B may be a reflective metal thin film or a transparent layer having a different refractive index of light from the hologram forming layer 5A. When the former is used, an opaque hologram is used, and the latter is used. When used, a transparent hologram can be obtained, and in any case, a reflection hologram with improved visibility when viewed by illumination from the viewer side is obtained.

  The materials constituting the reflective metal thin film include Al, Cr, Ti, Fe, Co, Ni, Cu, Ag, Au, Ge, Mg, Sb, Pb, Cd, Bi, Sn, Se, In, Ga, Alternatively, metals such as Rb, or oxides or nitrides of these metals can be used, and a reflective metal thin film can be formed by combining one or more of these metals. Among these, Al, Cr, Ni, Ag, Au, or the like is particularly preferable, and the film thickness is preferably 1 nm to 10,000 nm, more preferably 2 nm to 200 nm.

As a material constituting the transparent layer having a light refractive index different from that of the hologram forming layer 5A, there is a resin material of the hologram forming layer and a transparent material having a different light refractive index. The light refractive index of the transparent material may be larger or smaller than the light refractive index of the resin of the hologram forming layer, but the difference in the light refractive index from the hologram forming layer 6 is 0.1 or more. Preferably, it is 0.5 or more, and particularly preferably 1.0 or more. Specific examples of suitable materials include titanium oxide (TiO ₂ ), zinc sulfide (ZnS), and Cu • Al composite metal oxide. In addition, since a metal thin film having a thickness of 20 nm or less also has transparency, it can be used as a material constituting a transparent layer having a refractive index different from that of the hologram forming layer 5A.

  Whichever material is used, the hologram reflection layer 5A can be formed by a known method such as sublimation, vacuum deposition, sputtering, reactive sputtering, ion plating, or electroplating.

  The adhesive layer 6 is for affixing the authentication medium 1 to the adherend 7, and the adhesive constituting the adhesive layer 6 can be selected from various known ones and used. In addition, it is preferable to use a pressure-sensitive adhesive, so-called pressure-sensitive adhesive, in that adhesion is possible only by pressurization without heating.

  In the example described with reference to FIG. 2, in addition to the presence of the light selective reflection pattern layer 3, since it has a hologram layer, a three-dimensional image and interference colors brought about by the hologram layer are added. It is possible to obtain the authentication medium 2 that has an even higher effect of camouflaging the pattern of the authentication pattern layer 4.

It is a figure which shows the example of the laminated structure of the authentication medium of this invention. It is a figure which shows the state which affixed the authentication medium of the Example of this invention on the to-be-adhered body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Authentication medium 2 ... Transparent base material 3 ... Light selective reflection pattern layer 4 ... Authentication pattern layer 5 ... Hologram layer (5A: Hologram reflective layer, 5B: Hologram reflection layer)
6 …… Adhesive layer 7 …… Adherent

Claims (6)

  A laminate in which at least two layers of an authentication pattern layer and a light selective reflection pattern layer made of a material having a light selective reflection property that reflects either left circularly polarized light or right circularly polarized light of incident light are laminated. An authentication medium having a structure.   2. The authentication medium according to claim 1, wherein the light selective reflection pattern layer is laminated on at least one surface of a transparent substrate.   3. The authentication medium according to claim 1, wherein the light selective reflection pattern layer is made of cholesteric liquid crystal.   The authentication medium according to any one of claims 1 to 3, wherein the pattern of the authentication pattern layer has the same color as the light selective reflection pattern layer or an approximate color.   2. A hologram layer is laminated on the authentication pattern layer side or the light selective reflection pattern layer side of the laminated structure in which the authentication pattern layer and the light selective reflection pattern layer are laminated. The authentication medium according to claim 4. The adhesive layer is laminated on either the front or back of the laminated structure in which the authentication pattern layer, the light selective reflection pattern layer, and the hologram layer are laminated. The authentication medium described.

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