JP2008049550A - Authenticity judging medium and article having the same, authenticity judging medium label, authenticity judging medium transfer sheet and authenticity judging medium transfer foil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an authenticity judging means, which can easily judge forgery, falsification or the like and, in addition, disables easy forgery. <P>SOLUTION: The authenticity judging medium has: a latent image patterned layer which reverses the rotational direction of an incident light, and at the same time has permeability to visible light; an optical selectively reflecting layer having selectively reflectivities for reflecting either a left-handed circularly polarlized light or a right-handed circularly polarized light in incident light; a holographed layer; and a reflecting patterned layer in this order. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a medium for determining authenticity that can easily determine counterfeiting and falsification, and is difficult to counterfeit, and an article having the medium for determining authenticity. Furthermore, the present invention relates to a true / false determination medium label including the authenticity determination medium, a true / false determination medium transfer sheet, and a true / false determination medium transfer foil.

  For example, credit cards, deposit and saving cards, various types of cash vouchers, identification cards, and the like cause various troubles if they are forged or altered and used illegally. Therefore, in order to prevent damage caused by forgery or tampering, it is desirable to have a function that can identify the authenticity of itself. In addition, for example, luxury products such as wristwatches, leather products, precious metal products, jewelry, especially, what are said to be luxury brand products, audio products, electrical appliances, music software recorded on media, video software, game software, Computer software and the like are also subject to counterfeiting, and similarly, it is desirable to have a function that can identify authenticity.

  Conventionally, latent image patterns and holograms are frequently used for the purpose of enabling authenticity identification of various articles including the above-mentioned articles. The latent image pattern cannot be visually recognized in a normal state but can be visually recognized under specific conditions. Therefore, the latent image pattern can be used for authenticity determination and is also effective for preventing forgery. Further, the hologram has a manufacturing difficulty due to the precision of its structure, and therefore has a great effect of preventing forgery.

In recent years, an authenticity determination body having a cholesteric liquid crystal layer has been proposed as an alternative to a hologram (see Patent Document 1). Further, an authenticity determination medium combining a latent image pattern and a hologram (Patent Document 2) and an authenticity determination medium combining a latent image pattern and a cholesteric liquid crystal layer (see Patent Document 3) have also been proposed.
JP 2000-25373 A JP 2005-91786 A JP 2005-22231 A

  In the authenticity determination body described in Patent Document 1, the determination unit is still formed of an embossed hologram. According to the embossed hologram, although it is possible to form a precise pattern, the contact time between the embossed mold and the material to be embossed is made sufficiently long in order to sufficiently reproduce the unevenness of the hologram engraved in the embossed mold. Therefore, it is difficult to shorten the manufacturing time, and the manufacturing process of the embossing mold itself has a large number of steps, so that it is difficult to change the pattern of the determination unit.

  On the other hand, in the authenticity determination media described in Patent Documents 2 and 3, since the determination unit is formed of a latent image pattern formed of nematic liquid crystal or smectic liquid crystal, pattern formation or pattern change of the determination unit is easy. Furthermore, since the authenticity determination medium can perform both authenticity determination based on the latent image pattern and authenticity determination based on the reflectivity of the liquid crystal layer and the hologram layer in the background, the security is high and the anti-counterfeiting effect is high. Have However, in recent years, forgery means are becoming more sophisticated, and more effective forgery prevention means are required.

  Under such circumstances, it is an object of the present invention to provide a true / false determination means that can easily determine forgery or falsification and that cannot be easily counterfeited.

Means for achieving the object is as follows.
[1] A latent image pattern layer in which the rotation direction of incident light is reversed and has visible light transparency;
A light selective reflection layer having light selective reflectivity for reflecting either left circularly polarized light or right circularly polarized light among incident light;
An authenticity determination medium having a hologram forming layer and a reflective pattern layer in this order.
[2] The medium for authenticity determination according to [1], wherein the light selective reflection layer and / or the hologram forming layer has visible light permeability.
[3] The medium for authenticity determination according to [1] or [2], wherein the light selective reflection layer is a cholesteric liquid crystal layer.
[4] The authenticity determination medium according to any one of [1] to [3], wherein at least a part of the light selective reflection layer has a pattern shape.
[5] The authenticity determination medium according to any one of [1] to [4], wherein the latent image pattern layer is a smectic liquid crystal layer or a nematic liquid crystal layer.
[6] On the surface opposite to the surface having the latent image pattern layer of the authenticity determination medium according to any one of [1] to [5] and the authenticity determination medium of the authenticity determination medium. A medium label for authenticity determination having an adhesive layer on the surface.
[7] A medium transfer sheet for authenticity determination having a substrate having a peelable surface and a medium label for authenticity determination according to [6],
The medium transfer sheet for authenticity determination, wherein the surface opposite to the surface having the adhesive layer of the medium label for authenticity determination and the peelable surface of the base material face each other.
[8] A true / false determination medium transfer foil having a heat-sensitive adhesive layer, the authenticity determination medium according to any one of [1] to [5], and a base film in this order.
[9] An article having the authenticity determination medium according to any one of [1] to [5] in a visible manner.

According to the authenticity determination medium of the present invention, authenticity determination based on the latent image pattern and authenticity determination based on the reflectivity of the background light selective reflection layer and the pattern of the hologram layer can be performed.
In addition, since a sophisticated technique is required to pattern the reflection layer of the hologram, it is effective for preventing forgery to use the reflection layer as a pattern layer.

Hereinafter, the present invention will be described in more detail.

The authenticity determination medium of the present invention includes (1) a latent image pattern layer in which the rotation direction of incident light is reversed and has visible light transparency, and (2) any of left circularly polarized light and right circularly polarized light among incident light. A light selective reflection layer having a light selective reflection property that reflects either of them, (3) a hologram forming layer, and (4) a reflective pattern layer are provided in this order.
In the present invention, the “authentication medium” refers to a medium that can be used to discriminate between genuine products, counterfeit products, and falsified products. Further, in the present invention, “visible light transmission” means that the transmittance of visible light (wavelength 380 nm to 780 nm) is, for example, 50% or more.

  Since the latent image pattern layer has visible light transparency, it becomes transparent and becomes a latent image in a normal state, but has the property of reversing the rotation direction of incident light, so that it is visualized by overlapping polarizing plates. . In addition, since the background has a reflective layer (light selective reflection layer and hologram), a clear image appears when the polarizing plates are overlapped. Thereby, authenticity determination can be performed easily. As a polarizing plate for visually recognizing the latent image pattern layer, any of a linear polarizing plate, a left circular polarizing plate, and a right circular polarizing plate may be used. Thus, the reflectivity of the light selective reflection layer can also be observed.

  The authenticity determination medium of the present invention includes a light selective reflection layer in addition to the latent image pattern layer. Since the light selective reflection layer shows different reflectivity when the left circularly polarizing plate is overlapped with when the right circularly polarizing plate is overlapped, the authenticity determination is performed by observing the reflectivity using the circularly polarizing plate. be able to.

  In the authenticity determination medium of the present invention, the reflective layer located below the hologram forming layer has a pattern shape. This makes it easy to see the hologram in the part where the reflective layer is laminated in the lower layer, and the color tone and color change of the light selective reflection layer in the part where the reflective layer is not laminated in the lower layer (effect of changing the color depending on the viewing angle) It is possible to confirm the presence or absence of right circularly polarized light or left circularly polarized light by observing through a right circularly polarizing plate or a left circularly polarizing plate. Moreover, since the part where the hologram is easy to see and the part where the effect of the light selective reflection layer is easy to confirm are divided into patterns and observed, it has a complex appearance and authenticity determination with high authenticity discrimination Media can be provided.

As described above, the authenticity determination medium of the present invention can perform authenticity determination based on a latent image pattern, reflectivity of a light selective reflection layer, color tone and color change, and hologram pattern. In addition, the fact that authenticity can be determined by the latent image pattern and the reflectivity of the light selective reflection layer cannot be easily identified visually, and is effective in preventing forgery.
Moreover, in the authenticity determination medium of the present invention, the material for forming each layer is generally difficult to obtain and the layer formation is not easy, so that the anti-counterfeiting effect is extremely high. Furthermore, having a complicated layer structure as described above is also effective in preventing forgery. In particular, since a high-level technique is required to pattern the reflective layer forming the hologram, and to synchronize the hologram reflective pattern with the hologram reflective pattern, having a reflective pattern layer is extremely useful for preventing counterfeiting. It is valid.
Thus, according to the present invention, it is possible to provide an authenticity determination medium that is easy to determine authenticity and that has an excellent anti-counterfeit effect.
Next, details of each layer included in the authenticity determination medium of the present invention will be described.

Latent image pattern layer the latent image pattern layer has a visible light transmittance, and as long as it has the property of reversing the incident light is not particularly limited, may be formed of a known material. The latent image pattern layer is preferably a smectic liquid crystal layer or a nematic liquid crystal layer. Here, the smectic liquid crystal layer is a layer containing smectic liquid crystal molecules, and the nematic liquid crystal layer is a layer containing nematic liquid crystal molecules, and the liquid crystal molecules are oriented so that incident light is inverted. Can be shown. As the liquid crystal molecules, liquid crystal molecules that can be used in a cholesteric liquid crystal layer to be described later can be used. Since liquid crystal materials are generally difficult to obtain and require a high degree of alignment technology, it is effective for preventing forgery that the latent image pattern layer is a liquid crystal layer.

  The liquid crystal layer can be formed by printing an ink composition containing liquid crystal molecules, preferably an ink composition comprising a solvent solution of these liquid crystal molecules, in a pattern by various printing methods. By applying and drying the ink composition on a substrate having orientation and a light selective reflection layer, a liquid crystal layer in which liquid crystal molecules are aligned in the layer can be obtained. Further, the liquid crystal molecules in the layer can be aligned by applying the ink composition on the alignment film and drying it.

The substrate The latent image pattern layer can be directly formed on the light selective reflection layer, but the pattern layer is formed directly on one surface of the substrate or through an alignment film, and light selective reflection is performed on the other surface. The layer can also be formed directly or through an alignment film. Details of the alignment film will be described later.
As the base material, a plastic base material having visible light permeability and a base material having little retardation are desirable. Specific examples include polyethylene terephthalate (PET), polycarbonate, polyvinyl alcohol, polysulfone, polyethylene, polypropylene, polystyrene, polyarylate, triacetyl cellulose (TAC), diacetyl cellulose, polyethylene-ethyl vinyl alcohol, and the like.

Alignment film An alignment film may be formed between the latent image pattern layer and the light selective reflection layer. In this case, the alignment film plays a role of aligning the liquid crystal molecules in the pattern layer and the liquid crystal molecules in the light selective reflection layer to impart desired light reflectivity. Further, as described above, an alignment film can be formed on the surface of the substrate. Further, in order to align the liquid crystal molecules in the light selective reflection layer, an alignment film can be formed between the hologram forming layer and the light selective reflection layer.
The alignment film may be any film as long as it can be generally used as an alignment film, but preferably has visible light permeability so as not to affect the visibility of the light selective reflection layer and the hologram. . As the alignment film, for example, polyvinyl alcohol resin (PVA), polyimide resin, or the like can be used. The alignment film can be formed by applying a solvent solution of these resins by an appropriate application method and drying, followed by rubbing with a cloth, a brush, or the like. The alignment film functions as an adhesive layer when a substrate film, a latent image pattern layer, or a light selective reflection layer is selected as the alignment film, while the alignment film functions as an adhesive layer. Functions as a release layer. If the alignment film functions as a release layer, it can be used as a transfer foil. Also, for example, when used as a label in the configuration of latent image pattern layer / base material / alignment film (peeling layer) / light selective reflection layer / hologram forming layer / reflective pattern layer / adhesive layer, after being attached to the object If it is to be peeled off, the top of the peeling layer is peeled off, so that it is difficult to peel off as the whole authenticity determination medium, and the base material is peeled off, so that the label cannot be reattached. Therefore, the function of the alignment film as a release layer is effective for preventing falsification.
However, since the liquid crystal layer can align liquid crystal molecules in the layer without an alignment film depending on the physical properties of the lower layer, the alignment film is not essential. For example, when a substrate made of a stretched film (for example, a PET film) is used, molecules in the liquid crystal layer can be aligned without an alignment layer. In this case, the same effect as described above can be obtained by providing a release layer on at least one surface of the substrate. Moreover, when laminating | stacking a light selective reflection layer and a latent image pattern layer without a base material or an alignment film, a peeling layer can also be provided in the interface of both layers. As this release layer, for example, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polyester resin, polymethacrylate resin, polyvinyl chloride resin, cellulose resin, silicone resin, chlorinated rubber, casein, various surfactants, One or a mixture of two or more of metal oxides can be used. Among these, an acrylic resin having a molecular weight of about 20,000 to 100,000, or an acrylic resin and a vinyl chloride-vinyl acetate copolymer resin having a molecular weight of 8000 to 20000, and a polyester resin having a molecular weight of 1,000 to 5,000 as an additive. It is particularly preferable that the composition comprises ˜5% by weight. In particular, it is preferable that the peeling force between the latent image pattern layer and the light selective reflection layer is 1 to 5 g / inch (90 ° peeling). Moreover, it is preferable that the thickness exists in the range of 0.1 micrometer-2 micrometers from surfaces, such as peeling force and foil cutting.

  Furthermore, the same effect as described above can also be obtained by easily peeling the surface of the substrate facing the light selective reflection layer and / or the surface facing the latent image pattern layer. Some transparent films that can be used as the base material exhibit an adhesive strength that can be laminated with other layers, but usually a treatment for improving the adhesive strength is performed. Therefore, by not using this adhesive strength improving treatment or adjusting the degree thereof, by using a transparent film whose surface adhesive strength is intentionally lowered (easily peeled), The adhesive strength of can be reduced. If such a transparent film is used as a base material, since it peels on the easily peeled surface, the same effect as described above can be obtained.

  Examples of the adhesive strength improving treatment include corona discharge treatment, plasma treatment, flame treatment, primer coating treatment, and saponification treatment. Any processing can be performed using a known apparatus and method. The treatment conditions can be appropriately set so that an adhesive force can be applied to the surface of the base film so that it can be peeled off from the surface when it is peeled off. In addition, when a film having an adhesive strength that can be bonded to other layers even if untreated, such as a polyethylene terephthalate film, is used as a base material, it is peeled off from the base material surface by not performing the adhesive strength improving treatment. be able to.

Further, if the film thickness of the base film is excessively reduced or the components are adjusted and the strength of the base material itself is intentionally reduced, an external force is applied to the article to which the authenticity determination medium of the present invention is applied. If the medium is peeled off, the base material is destroyed, so that the light selective reflection layer and the pattern layer are separated. Also by this, the same effect as described above can be obtained.
As described above, providing a fragile portion (the layer included in the authenticity determination medium and the lowest strength of the interface between the layers) between the light selective reflection layer and the latent image pattern layer is counterfeiting It is effective for prevention.

Light-selective reflection layer The light-selective reflection layer only needs to have a light-selective reflectivity that reflects either left circularly polarized light or right circularly polarized light in incident light, and is preferably a cholesteric liquid crystal layer. Here, the cholesteric liquid crystal layer is a layer containing cholesteric liquid crystal molecules. In general, liquid crystal materials are difficult to obtain, and advanced alignment techniques are required. Therefore, if the light selective reflection layer is a cholesteric liquid crystal layer, a high forgery prevention effect can be obtained.

  The light selective reflection layer preferably has visible light transparency. If the light selective reflection layer is transparent to visible light, the pattern of the lower hologram can be easily visually confirmed.

  When the light selective reflection layer is a cholesteric liquid crystal layer, a liquid crystal material to be used is not particularly limited, and a known material can be used. The cholesteric liquid crystal layer can be formed by dissolving a cholesteric liquid crystal material in an appropriate solvent, applying it by various printing methods, and drying it. At this time, an ultraviolet-polymerizable composition is prepared using a polymerizable cholesteric liquid crystal, and the obtained ultraviolet-polymerizable composition is applied by various printing methods, and after drying, it is polymerized by irradiation with ultraviolet rays. You can also.

  Specifically, as a material for forming the cholesteric liquid crystal layer, a three-dimensionally crosslinkable liquid crystalline polymerizable monomer molecule or polymerizable oligomer molecule can be used. A layer containing cholesteric liquid crystal molecules can be obtained by adding an arbitrary chiral agent to a predetermined polymerizable monomer molecule or polymerizable oligomer molecule.

  Examples of the three-dimensionally crosslinkable monomer molecule include a mixture of a liquid crystal monomer and a chiral compound as disclosed in, for example, JP-A-7-258638 and JP-T-10-508882. As a more specific example, for example, liquid crystalline monomers represented by the following general chemical formulas (1) to (11) can be used. In the case of the liquid crystalline monomer represented by the general chemical formula (11), X is preferably an integer in the range of 2 to 5.

  Moreover, as a chiral agent, a chiral agent as shown, for example by the following general chemical formula (12)-(14) can be used. In the case of the chiral agent represented by the general chemical formulas (12) and (13), X is preferably an integer in the range of 2 to 12, and in the case of the chiral agent represented by the general chemical formula (14), X Is preferably an integer in the range of 2-5.

  When oligomer molecules are used, a cyclic organopolysiloxane compound having a cholesteric phase as disclosed in, for example, JP-A-57-165480 can be used. For example, a cholesteric liquid crystal layer can be obtained by adding about several to 10% of a chiral agent to polymerizable monomer molecules or polymerizable oligomer molecules.

  In the authenticity determination medium of the present invention, it is preferable that the hologram forming layer located under the light selective reflection layer has visible light transmittance. If the hologram forming layer has visible light transmission, especially in the part where the reflective pattern layer is not laminated in the lower layer, it is not hindered by the reflected light from the hologram, and the authenticity determination by the color change of the light selective reflection layer There is also an advantage that the color tone of the light selective reflection layer can be utilized. In particular, the liquid crystal layer can express a variety of colors by adjusting the type of liquid crystal molecules used, the amount of chiral agent added, etc., but liquid crystal materials are generally difficult to obtain, and advanced manufacturing techniques are required. Since it is required, it is difficult to reproduce the color of the liquid crystal layer. Therefore, as described above, making the hologram forming layer visible light transmissive and making use of the color of the light selective reflection layer is effective in preventing forgery. The cholesteric liquid crystal layer can be formed as a layer having a substantially uniform thickness, but can also be a pattern layer in which a pattern is formed depending on the presence or absence of the layer or a difference in thickness. The pattern layer can be formed using various printing methods. If at least a part of the light selective reflection layer has a pattern shape, an effect of changing the color depending on the viewing angle can be obtained according to the pattern, which is effective in preventing forgery.

  The authenticity determination medium of the present invention can also have two or more light selective reflection layers. In this case, two or more light selective reflection layers can be directly laminated, and a substrate can be disposed between the two light selective reflection layers. When the two light selective reflection layers are laminated via the base material, it is possible to provide a true / false determination medium having a more complicated effect of changing the color depending on the viewing angle. Further, it is possible to avoid that the solvent in the coating liquid for forming the light selective reflection layer adversely affects the light selective reflection layer previously laminated, as compared with the case where two or more light selective reflection layers are directly laminated. There is also an advantage. Also, a part of the light selective reflection layer provided in two or more layers can be a pattern layer.

  The light selective reflection layer may be formed of two or more layers having different light reflectivities. For example, the light reflectivity can be changed by changing the thickness of a plurality of cholesteric liquid crystal layers or forming each layer using liquid crystal materials having different spiral pitches. When a cholesteric liquid crystal layer is formed from an ultraviolet polymerizable composition using a polymerizable cholesteric liquid crystal as described above, a polymerizable nematic liquid crystal and a chiral agent are used in combination, and at this time, the polymerizable nematic liquid crystal and the chiral agent are used. Cholesteric liquid crystal layers having different helical pitches can be formed by preparing and using ultraviolet polymerizable compositions having different blending ratios with the agent.

Hologram Formation Layer As the hologram formation layer, a known hologram formation layer can be used, but in order to take advantage of the color tone change of the light selective reflection layer as described above, a layer having visible light permeability is preferable. For example, the hologram forming layer can be produced by forming fine irregularities of a relief hologram on one side of a layer made of a transparent resin material. Various resin materials such as various thermosetting resins, thermoplastic resins, and ionizing radiation curable resins can be selected as the transparent resin material for constituting the hologram forming layer. Examples of the thermosetting resin include unsaturated polyester resins, acrylic urethane resins, epoxy-modified acrylic resins, epoxy-modified unsaturated polyester resins, alkyd resins, and phenol resins. Examples of the thermoplastic resin include acrylate resin, acrylamide resin, nitrocellulose resin, and polystyrene resin. These resins can be used alone or as two or more types of copolymers. These resins may be used alone or in combination with two or more kinds of isocyanate resins, metal soaps such as cobalt naphthenate and zinc naphthenate, peroxides such as benzoyl peroxide and methyl ethyl ketone peroxide, benzophenone, acetophenone, anthraquinone, naphthoquinone, A heat or ultraviolet curing agent such as azobisisobutyronitrile or diphenyl sulfide may be blended. Examples of the ionizing radiation curable resin include epoxy acrylate, urethane acrylate, and acrylic-modified polyester. Other monofunctional or polyfunctional monomers, oligomers and the like can be conjugated to such ionizing radiation curable resins for the purpose of adjusting the cross-linking structure and viscosity.

  The hologram forming layer can be directly formed by developing the photosensitive resin material by performing interference exposure of the hologram. However, a relief hologram prepared in advance or a duplicate thereof, or a plating mold thereof is duplicated. Molding can also be performed by using it as a mold and pressing the mold surface against the resin material. When a thermosetting resin or ionizing radiation curable resin is used, it is cured by heating or irradiation with ionizing radiation while the uncured resin is kept in close contact with the mold surface, and the cured transparent film is peeled off after curing. The fine irregularities of the relief hologram can be formed on one side of the layer made of the resin material. In the present invention, a diffraction grating forming layer having a diffraction grating formed in a pattern by a similar method is also included in the hologram forming layer. A combination of the hologram forming layer and the diffraction grating forming layer is referred to as an optical diffraction structure layer.

Reflective pattern layer In the authenticity determination medium of the present invention, the reflective layer forming the hologram is in a pattern. As a result, it is easy to see the hologram image in the portion where the reflective pattern layer is laminated in the lower layer, and it is easy to check the color tone and color change of the light selective reflection layer in the portion where the reflective pattern layer is not laminated in the lower layer. By observing through a right circularly polarizing plate or a left circularly polarizing plate, it is possible to confirm the presence or absence of right circularly polarized light or left circularly polarized light.

  When the reflective pattern layer is formed from a material such as a metal that reflects light, an opaque type hologram can be obtained, and when formed from a material having visible light transparency, a transparent type hologram can be obtained.

  An example of the pattern of the reflective pattern layer is shown in FIG. As shown in FIG. 1 (a), the pattern has a reflection layer in which squares that are narrow in the left-right direction and long in the vertical direction are arranged at equal intervals, for example, the length (ie, width) of the quadrangle in the left-right direction. Or a stripe pattern formed by arranging them at equal intervals, or as shown in FIG. 1 (b), the reflective layer has a geometric shape (rectangular shape and star shape). May be. Moreover, when a specific pattern as described above is used as a positive pattern, the pattern may be a negative pattern thereof. Note that these patterns are merely examples, and the patterns can be freely determined mainly from the viewpoint of design, and may be characters or symbols other than geometric shapes, or arbitrary shapes. Further, the pattern may be synchronized with the hologram of the hologram forming layer. Here, “synchronization” means that the hologram pattern and the pattern of the reflective pattern layer are integrated to form one continuous pattern, while “unsynchronized” means that the pattern of the hologram pattern and the reflective pattern layer is formed. Means that they do not match. As an out-of-tune mode, there are a pattern in which the reflective pattern layer has a continuous pattern, and a pattern in which the hologram pattern has a continuous pattern. As described above, since an advanced technique is required to synchronize the pattern of the reflective pattern layer with the pattern of the hologram, the anti-counterfeiting effect of the authenticity determination medium formed using this technique is extremely high.

  The size of the pattern is not limited as long as it can be resolved with the naked eye. However, when observing that the color changes depending on the viewing angle of the light selective reflection layer, for example, if the shape is a rectangle, the height and width are 1 mm × It can be 1 mm or more, preferably 3 mm × 3 mm or more, and more preferably 5 mm × 5 mm or more. In the case of a geometric shape, if it is circular, the diameter can be 1 mm or more, preferably 3 mm or more, more preferably 5 mm or more, and in the case of other shapes, an inscribed circle The diameter can be, for example, 1 mm or more, preferably 3 mm or more, more preferably 5 mm or more.

As shown in FIGS. 1C and 1D, the reflective pattern layer may be laminated in a fine pattern. In this case, as shown in FIG. 1C, the pattern (fine pattern) has a reflective layer composed of a finite-width line extending from the left side toward the upper side toward the right side toward the upper side. The line pattern may be a fine pattern arranged at a pitch of about twice, or as shown in FIG. 1 (d), a circular or square reflective layer may be formed. It may be arranged at an equal pitch.
These fine patterns are merely examples, and the patterns constituting the fine patterns can be freely determined. Therefore, geometric patterns other than line patterns and halftone dots, and shapes such as letters or symbols are used. There may be. The size of the pattern constituting the fine pattern is preferably a fine one that is difficult to observe or cannot be observed by normal observation. In the case of a line pattern, the line width is set to 0.3 mm, for example. Hereinafter, it can be preferably 0.1 mm or less. The pattern can be made small as long as it can be formed, but is preferably about 0.01 mm or more in practice. When the halftone dot is circular, the diameter can be, for example, 0.3 mm or less, preferably 0.1 mm or less, and preferably about 0.01 mm or more. In addition, when the halftone dots are rectangular, the length and width can be set to, for example, 0.3 mm × 0.3 mm or less, preferably 0.1 mm × 0.1 mm or less, and about 0.01 mm × 0.01 mm or more. It is preferable that In the case of other shapes, the diameter of the inscribed circle can be, for example, 0.3 mm or less, preferably 0.1 mm or less, and preferably about 0.01 mm or more.

  When the pattern is a fine pattern, an outer shape pattern (in the case of FIG. 1 (c) or (d), an outer shape square) can be arbitrarily set. The pattern may be synchronized with the hologram pattern on the hologram forming layer.

  When the reflective pattern layer forms a fine pattern, the area ratio of the reflective pattern layer is, for example, 20% to 80%, and preferably 30% to 60%. When the reflective pattern layer is formed in a fine pattern, the pattern of the hologram can be confirmed in the area where the fine pattern exists, that is, in the external pattern, and the color of the light selective reflection layer changes depending on the viewing angle. You can also confirm that you want to.

  Examples of metal materials for forming the reflective pattern layer include Al, Cr, Ti, Fe, Co, Ni, Cu, Ag, Au, Ge, Mg, Sb, Pb, Cd, Bi, Sn, Se, In, A metal such as Ga or Rb, or an oxide or nitride of the metal can be used, and one or more of these can be used in combination. 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 for forming the reflective pattern layer having visible light transmittance, a transparent material having a refractive index different from that of the material forming the hologram forming layer can be used. The light refractive index of the transparent material may be larger or smaller than the light refractive index of the material forming the hologram layer, but the difference in the light refractive index from the hologram forming layer is 0.1 or more. It is preferable that it is preferably 0.5 or more, and particularly preferably 1.0 or more. Specific examples of the material preferably used include titanium oxide (TiO ₂ ), zinc sulfide (ZnS), Cu · Al composite metal oxide, and the like. 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 light refractive index different from that of the hologram layer.

  Various methods are mentioned as a method of forming a reflective pattern layer. For example, a method of forming a thin film by a vacuum deposition method, a sputtering method, an ion plating method, or the like through a pattern mask, a printing method, or the like can be used. Alternatively, a method of removing unnecessary portions after forming the reflective layer over the entire surface can be used.

Below, based on FIG. 2 and 3, an example of the method of forming a reflective pattern layer by forming a reflective layer in the whole surface, and removing an unnecessary part is demonstrated.
FIG. 2 is an explanatory diagram of a method for patterning a reflective layer using a water-soluble resin pattern. In FIG. 2 and FIG. 3 quoted in the following description, layers other than the hologram forming layer, such as a light selective reflection layer and a latent image pattern layer, are omitted.

As shown in FIG. 2 (a), first, a hologram forming layer having hologram fine irregularities on its lower surface is produced.
Next, as shown in FIG.2 (b), a water-soluble resin pattern is formed in the part where the reflective metal layer of the surface in which the fine unevenness | corrugation of the hologram formation layer was formed is unnecessary. The water-soluble resin pattern can be formed by printing using a water-soluble resin composition in which a water-soluble resin or a water-swellable resin is dissolved or dispersed, so-called water-soluble ink.
Then, as shown in FIG.2 (c), a reflective layer is formed in one surface in which the water-soluble resin pattern was formed. Then, the surface on which the reflective layer is formed is contacted with water or an acidic or alkaline aqueous solution to remove the water-soluble resin pattern, and the portion of the reflective layer on which the water-soluble resin pattern is laminated is removed. As a result, as shown in FIG. 2D, the portion of the reflective layer where the water-soluble resin pattern was not laminated remains, and the reflective layer is formed in a pattern.

FIG. 3 is an explanatory diagram of a method for patterning a reflective layer using a resist pattern.
First, as shown in FIG. 3A, a hologram forming layer having hologram fine irregularities on its lower surface is formed.
Next, as shown in FIG. 3B, a reflective layer is formed on one surface of the hologram forming layer on which fine irregularities are formed.
Thereafter, as shown in FIG. 3C, a resist pattern is formed on the lower surface of the reflective layer where the reflective layer is required. Thereafter, an etching solution is applied to the surface on which the resist pattern is formed, and the reflective layer in a portion other than the portion covered with the resist pattern is etched and removed. As a result, as shown in FIG. 3D, the portion of the reflective layer covered with the resist pattern remains, and the reflective layer is formed in a pattern. Note that the resist pattern remaining on the reflective layer formed in a pattern may be left as it is, but if it is desired to be removed, the remaining resist pattern may be dissolved.

The above method using a water-soluble resin pattern or a resist pattern is suitable for mass-producing authenticity determination media having the same pattern. In addition to the various methods described above, the reflective layer may be patterned by partially heating the reflective layer and melting the heated portion of the reflective layer by heating with a thermal head or laser light irradiation. Alternatively, there is a method of removing by evaporation. This method can be performed even after each layer is laminated, and if anything, it is suitable for patterning based on individual information.
The various methods for patterning the reflective layer described above can be used in any combination.

  Furthermore, in the present invention, a visible light transmissive reflective layer can be further laminated on the reflective pattern layer. Thereby, since the reflectivity of the background of the latent image pattern becomes higher, there is an advantage that a clear image appears when the polarizing plates are overlapped, and authenticity determination becomes easier.

Underlayer It is also possible to provide an underlayer on the surface of the reflective pattern layer opposite to the surface having the hologram forming layer. As described above, when the hologram forming layer has visible light transparency, the color of the base layer can be visually recognized without being blocked by the hologram. The medium for authenticity determination of various colors can be obtained by combining with the above. Moreover, the visibility of a light selective reflection layer and a hologram can also be improved by providing a colored layer as a base layer. In addition, it is also possible to attach a design such as characters and figures to the underlayer. The underlayer can be formed from a material constituting an adhesive layer described later. In any case, the base layer having a desired color tone can be obtained by adding an appropriate amount of pigment, dye or the like. As pigments to be added, inorganic pigments such as Gunjo, Cadmium Yellow, Bengala, Chrome Yellow, Lead White, Titanium White, Carbon Black, and other organic pigments such as azo, triphenylmethane, quinoline, anthraquinone, phthalocyanine, etc. As dyes, azo dyes, anthraquinone dyes, indigoid dyes, sulfur dyes, triphenylmethane dyes, xanthene dyes, xanthene dyes, alizarin dyes, acridine dyes, quinoneimine dyes (azine dyes, oxazine dyes, thiazine dyes) , Thiazole dyes, methine dyes, nitro dyes, nitroso dyes, and the like. The density | concentration of the dye and pigment to add can be adjusted according to a desired color tone.

  The authenticity determination medium of the present invention may have a layer other than the above-mentioned layers at an arbitrary position, if necessary. For example, it can also have a well-known protective layer and various functional layers.

  In the authenticity determination medium of the present invention, the thickness of each layer is appropriately set and is not particularly limited. For example, the thickness of the latent image pattern layer is 0.1 to 20 μm, and light selection is performed. The reflective layer has a thickness of 0.1 to 30 μm, and the hologram forming layer has a thickness of 0.1 to 20 μm. Moreover, when providing a base material, an alignment film, and a base layer, the thickness of a base material is 3-250 micrometers, for example, the thickness of an alignment film is 0.05-20 micrometers, for example, and the thickness of a base layer is 0. It can be 1-50 micrometers.

[Authentication media label, authenticity media transfer sheet]
Further, the present invention provides a true / false determination medium according to the present invention and a true / false having an adhesive layer on a surface of the authenticity determination medium opposite to the surface having the latent image pattern layer of the authenticity determination medium. The present invention relates to a determination medium label. The authenticity determination medium label can be produced by laminating an adhesive layer on the authenticity determination medium of the present invention. The pressure-sensitive adhesive layer is not particularly limited, and can be formed using a known adhesive such as an acrylic adhesive, a natural rubber adhesive, a synthetic rubber adhesive, or a silicone rubber adhesive. The pressure-sensitive adhesive layer is preferably a heat-sensitive adhesive layer or a pressure-sensitive adhesive layer. The thickness of the adhesive layer can be, for example, about 0.1 to 40 μm. The pressure-sensitive adhesive layer can also function as the above-described underlayer, but an adhesive layer can be provided separately from the above-described underlayer.

  Further, the medium label for authenticity determination may be provided with a release paper on the adhesive layer in order to protect the adhesive layer until use. As the release paper, for example, a material obtained by coating a base material such as paper or film with a silicon-based resin, wax, paraffin, or the like can be used. The medium label for authenticity determination can be used after being cut into an appropriate size by die cutting or the like.

  Furthermore, the present invention relates to a true / false determination medium transfer sheet having a substrate having a peelable surface and the true / false determination medium label of the present invention. In the authenticity determination medium transfer sheet, the surface opposite to the surface having the adhesive layer of the authenticity determination medium label and the peelable surface of the base material face each other. A well-known thing can be used as a base material which has a peelable surface.

  The medium label for authenticity determination and the medium transfer sheet for authenticity determination of the present invention can be applied to various articles. The label is applied by sticking the pressure-sensitive adhesive layer toward the article serving as the adherend, and the transfer sheet is bonded to the article side serving as the adherend. It can be applied by peeling the material.

[Media transfer foil for authenticity determination]
Furthermore, this invention relates to the medium transfer foil for authenticity determination which has a heat sensitive adhesive layer, the authenticity determination medium of this invention, and a base film in this order. The transfer foil can be produced by providing a heat-sensitive adhesive layer on one surface of the authenticity determination medium of the present invention and providing a base film on the other. In the transfer foil, it is preferable that the heat-sensitive adhesive layer is provided on the reflective pattern layer and the base film is provided on the latent image pattern layer. The transfer foil may adhere the medium for authenticity determination and the adherend of the present invention by bringing the heat-sensitive adhesive layer and the adherend into contact with each other and applying heat from the base film side. it can.

  The base film is not particularly limited as long as it has resistance to heat and pressure applied during thermal transfer. For example, polyethylene film, polypropylene film, polyethylene fluoride film, polyvinylidene fluoride film, polyvinyl chloride film, polyvinylidene chloride film, ethylene-vinyl alcohol copolymer film, polyvinyl alcohol film, polymethyl methacrylate film, polyether sulfone film Polyether ether ketone film, polyamide film, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer film, polyester film such as polyethylene terephthalate film, and transparent resin film such as polyimide film can be used.

  The heat-sensitive adhesive layer can be formed using a known thermocompression adhesive. Examples of such an adhesive include ethylene-vinyl acetate copolymer resin (EVA), polyamide resin, polyester resin, polyethylene resin, ethylene-isobutyl acrylate copolymer resin, butyral resin, polyvinyl acetate and its copolymer resin, Cellulosic resin, polymethyl methacrylate resin, polyvinyl ether resin, polyurethane resin, polycarbonate resin, polypropylene resin, epoxy resin, phenol resin, styrene butadiene styrene block copolymer (SBS), styrene isoprene styrene block copolymer (SIS) Further, thermoplastic resins such as styrene ethylene butylene styrene block copolymer (SEBS) and styrene ethylene propylene styrene block copolymer (SEPS) can be used. Among these, a layer that can be heat-sealed at a temperature of 180 ° C. or lower is preferable, and an ethylene-vinyl acetate copolymer resin (EVA) having an acetic acid content of 25% or more is preferably used.

  The said transfer foil can also have a peeling layer between a base film and the medium for authenticity determination of this invention. Thereby, it becomes possible to remove a base film after thermocompression bonding. As the release layer, for example, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polyester resin, polymethacrylate resin, polyvinyl chloride resin, cellulose resin, silicone resin, chlorinated rubber, casein, various surfactants, metal From an oxide or the like, one or a mixture of two or more can be used. Among them, an acrylic resin having a molecular weight of about 20,000 to 100,000, or an acrylic resin and a vinyl chloride-vinyl acetate copolymer resin having a molecular weight of 8,000 to 20,000, and a polyester resin having a molecular weight of 1,000 to 5,000 as an additive is used. It is particularly preferable that the composition comprises ˜5% by weight. Moreover, it is preferable that the said peeling layer is a thing from which the peeling force between the said base film and a reflection layer will be 1-5 g / inch (90 degree peeling). Moreover, it is preferable that the thickness exists in the range of 0.1 micrometer-2 micrometers from surfaces, such as peeling force and foil cutting.

  The authenticity determination medium of the present invention can be applied to various articles in the form of the label, sheet, transfer foil and the like as described above. The article to which the authenticity determination medium of the present invention is applied can be various articles that are required to prevent forgery and tampering. Specifically, cash certificates such as gift certificates, securities, stock certificates, tickets, various cards such as credit cards, prepaid cards, ID cards, tickets, banknotes, passports, identification cards, public competition voting tickets, video software, personal computers Authenticity determination seals used in software, etc., threaded paper such as thread paper.

  The authenticity determination medium of the present invention can be applied to an article that is an authenticity determination target so as to be visible. Here, “visually visible” means that the existence of the authenticity determination medium can be recognized from the outside. FIG. 4 shows a specific example of an article having the authenticity determination medium of the present invention so as to be visible.

  FIG. 4 (a) is an information recording body capable of authenticity determination, having the authenticity determination medium of the present invention on a part of the surface. The information recording medium is a sheet-like material made of paper or plastic sheet as a base material. For example, as shown in FIG. Information such as a pattern is formed and recorded by means such as printing.

  In FIG. 4B, the medium for authenticity determination according to the present invention is built in a sheet-like material in advance so as to be visible, and a concave opening that does not become a through-hole in paper or a plastic sheet. And a medium for determining authenticity can be seen from the opening. In order to facilitate the application of the authenticity determination medium, for example, it is cut into a very narrow width of about 0.5 mm to 5 mm (vertically long thread shape in FIG. 4B). Can be applied by providing an opening in the layer constituting the surface layer and sandwiching a thread-like authenticity determination medium between the layers of the sheet-like material. In the thread-like authenticity determination medium, if necessary, the surface of the base material is colored with a dark color or the like for the purpose of improving the visibility when irradiated with circularly polarized light, and is incorporated in a sheet-like material. In order to ensure adhesion between the thread-like authenticity determination medium and the sheet-like material in the state, an adhesive layer, preferably a heat-sensitive adhesive layer, is preferably laminated on one side or both sides. Such a sheet-like material to which a medium for authenticity determination is applied is suitable for use in an information recording medium, particularly a printed matter having a cash voucher or other economic value.

  Hereinafter, the present invention will be described with reference to examples. However, this invention is not limited to the aspect shown in the Example.

[Example 1]
(1) Formation of Latent Image Pattern Layer A PET film is prepared, and gravure printing is performed on the surface using a polymerizable nematic liquid crystal ink, dried, and then irradiated with ultraviolet rays to form characters and designs. A latent image pattern layer having a thickness of 2 μm was obtained.

(2) Formation of light selective reflection layer (cholesteric liquid crystal layer) Cholesteric liquid crystal ink is applied to the entire surface of the PET film opposite to the surface on which the latent image pattern layer is formed, and dried to express a cholesteric liquid crystal phase. Then, ultraviolet rays were irradiated to form a cholesteric liquid crystal layer having a thickness of 2 μm that reflects only the right circularly polarized light.

(3) Formation of hologram forming layer A transparent ultraviolet curable resin composition is applied onto the cholesteric liquid crystal layer, and the ultraviolet ray is irradiated while keeping the surface of the relief hologram replication mold in contact with the transparent ultraviolet curable resin. A relief hologram was formed by curing the resin composition.

(4) Formation of reflective pattern layer On the surface where the relief hologram was shaped, printing was performed on a portion other than the portion where the reflective pattern layer was to be formed by a gravure printer using a water-soluble gravure ink. Then, when Al was vapor-deposited on the entire printed surface and washed with water, the Al vapor-deposited layer on the water-soluble ink layer was removed together with the water-soluble ink layer. As a result, a reflective pattern layer having a thickness of 400 nm was formed.

[Example 2]
A medium for authenticity determination was produced in the same manner as in Example 1 except that the method for forming the reflective pattern layer was changed as follows.
On the surface where the relief hologram was formed, printing was performed on a portion other than the portion where the reflective pattern layer was to be formed by using a water-soluble silk ink by a silk printing machine so as to synchronize with the pattern of the original fabric. Then, when Al was vapor-deposited on the entire printed surface and washed with water, the Al vapor-deposited layer on the water-soluble ink layer was removed together with the water-soluble ink layer. As a result, a reflective pattern layer having a thickness of 400 nm was formed.

[Example 3]
A medium for authenticity determination was produced in the same manner as in Example 1 except that the method for forming the reflective pattern layer was changed as follows.
After performing Al vapor deposition on the entire surface of the relief hologram, printing was performed on the Al vapor deposition surface using an etching resist ink so as to synchronize with the pattern of the original fabric. The printed sheet was alkali etched with a 1% aqueous sodium hydroxide solution. Thereby, Al vapor deposition remained in the part in which the resist ink layer exists, Al vapor deposition of the other part was removed, and the reflective pattern layer with a thickness of 400 nm was formed.

When the authenticity determination media obtained in Examples 1 to 3 were observed from the latent image pattern layer printing surface, the latent image could hardly be observed, but the color change of the cholesteric liquid crystal layer was visible. . Moreover, the pattern of the hologram was also confirmed.
Further, when the right circularly polarizing plate was superimposed on the obtained authenticity determination medium, the background portion of the latent image pattern layer became a bright state colored based on the helical pitch of the cholesteric liquid crystal layer, and the latent image pattern layer was formed. The area became dark and the latent image could be recognized. Further, when the left circularly polarizing plate was overlapped, the background portion of the latent image pattern layer looked dark because no reflection occurred, but the portion where the latent image pattern layer was formed became bright and the latent image could be recognized.
In addition, regardless of the right and left circularly polarizing plates, the brightness (black and white) of the latent image pattern changed depending on the viewing angle, and the latent image pattern could be confirmed in the portion where the reflective pattern layer was present in the lower layer. Further, when the linear circularly polarizing plate was overlapped and the polarizing plate was rotated, light and dark (whether the latent image pattern was bright and the background was dark or the latent image pattern was dark and the background was bright) changed.
Since it is not easy to form a true / false determination medium showing a complicated appearance in this way, it is effective in preventing forgery.

[Example 4]
A medium for authenticity determination was obtained in the same manner as in Example 2 except that another cholesteric liquid crystal was pattern-printed on the cholesteric liquid crystal layer and information such as patterns and characters was added.
Since the authenticity determination medium obtained in Example 4 has a patterned cholesteric liquid crystal layer, the effect of changing the color depending on the viewing angle could be obtained according to the pattern.

[Example 5]
An adhesive layer (transparent or colored) was provided by an adhesive process on the reflective pattern layer of the authenticity determination medium obtained in Example 1, and a punching process was performed to obtain an authenticity determination medium label.

[Example 6]
A heat seal was applied on the reflective pattern layer of the authenticity determination medium obtained in Example 1, and transferred to paper or a plastic card.

[Example 7]
The authenticity determination medium obtained in Example 1 was rolled into a paper so that the latent image pattern layer was positioned on the surface side to obtain a thread paper.

[Example 8]
After providing a colored layer on the reflective pattern layer of the medium for authenticity determination obtained in Example 1, the paper was rubbed into the paper so that the latent image pattern layer was positioned on the surface side to obtain a thread paper.

An example of the pattern of a reflective pattern layer is shown. It is explanatory drawing of patterning of a reflective layer. It is explanatory drawing of patterning of a reflective layer. The specific example of the article | item which has the authenticity determination medium of this invention visibly is shown.

Claims (9)

A latent image pattern layer in which the rotation direction of incident light is reversed and has visible light transparency;
A light selective reflection layer having light selective reflectivity for reflecting either left circularly polarized light or right circularly polarized light among incident light;
An authenticity determination medium having a hologram forming layer and a reflective pattern layer in this order. The medium for authenticity determination according to claim 1, wherein the light selective reflection layer and / or the hologram forming layer has visible light permeability. The authenticity determination medium according to claim 1, wherein the light selective reflection layer is a cholesteric liquid crystal layer. The medium for true / false determination according to claim 1, wherein at least a part of the light selective reflection layer has a pattern shape. The medium for authenticity determination according to any one of claims 1 to 4, wherein the latent image pattern layer is a smectic liquid crystal layer or a nematic liquid crystal layer. 6. The adhesive layer on a surface opposite to the surface having the latent image pattern layer of the authenticity determination medium according to claim 1 and the authenticity determination medium of the authenticity determination medium. A medium label for authenticity determination. A medium transfer sheet for authenticity determination having a base material having a peelable surface and a medium label for authenticity determination according to claim 6,
The medium transfer sheet for authenticity determination, wherein the surface opposite to the surface having the adhesive layer of the medium label for authenticity determination and the peelable surface of the base material face each other. A medium transfer foil for authenticity determination having a heat-sensitive adhesive layer, the medium for authenticity determination according to any one of claims 1 to 5, and a base film in this order. An article having the authenticity determination medium according to any one of claims 1 to 5 in a visible manner.

Images