JP2007128393A - Ic card and optically variable device transfer foil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein static electricity developed as an IC card is fed through a card reader may damage an IC chip or generate noise to cause abnormal data reading and recording, specifically, static electricity developed owing to friction between rubber rollers used for the feeding and the plastic card may reach and discharge at a voltage of several thousand volts to damage the IC chip. <P>SOLUTION: An IC card having at least an optically variable device (OVD) on a substrate has a conductive layer formed as a part of layers constituting the optically variable device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an IC card and an optically variable device transfer foil used for a credit card, a cash card, etc. that require a forgery preventing effect. More specifically, the present invention relates to an IC card on which an OVD image is formed and an optical variable device transfer foil in order to impart an anti-counterfeit effect to the IC card.

  A multilayer film that can express stereoscopic images and special decorative images using light interference, such as a multilayer film that produces a color change (color shift) depending on the viewing angle, by superimposing holograms, diffraction gratings, and thin films with different optical properties. Development of an optical variable device (OVD (Optically Variable Device)) is underway.

  An OVD such as a hologram or a diffraction grating has a diffractive structure such as a fine concavo-convex pattern or a striped pattern having a different refractive index, thereby supporting the viewing angle by light diffraction and interference (ie, the hologram). Depending on the angle, a unique image or color change (color shift) occurs. On the other hand, the multilayer thin film has a structure in which ceramics and metal materials having different optical properties are laminated in layers. This multi-layered thin film is a display technology that uses the interference effect of light obtained by the optical characteristics and film thickness of the constituent materials, and has reflection / transmission characteristics in a specific wavelength range. A change (color shift) occurs.

  In this specification, a display device using interference of light such as a hologram, a diffraction grating, and a multilayer thin film is generically referred to as an optical variable device (OVD). The optically variable device generally includes an optically variable layer and an adhesive layer. In the case of an optically variable device transfer foil, the optically variable device includes a release layer, an optically variable layer, an adhesive layer, and other layers.

  On the other hand, plastic cards represented by credit cards and cash cards have been widely used for shopping and deposit withdrawals. In the past, information about the card used is stored on a magnetic tape provided on the card, and is authenticated by reading it at the time of transaction, thereby completing the transaction.

  In recent years, IC cards in which information is recorded in IC chips instead of magnetic tape are rapidly spreading. There are a contact IC card in which a terminal for communication is exposed on the surface and contacts the communication terminal of the terminal for communication, and a non-contact IC card for communication through an antenna in the card.

  In order to improve the anti-counterfeiting effect of these plastic cards and to improve the design, proposals have been made to provide the above-mentioned OVD over the entire surface or a part thereof.

The patent literature is as follows.
JP-A-9-300863

  However, the above technique does not cause a problem in a magnetic card without an IC, but causes a problem in a card provided with an IC.

  That is, static electricity is generated when the card is transported by the card reader, and the IC chip is destroyed or noise is generated, causing abnormal data reading and recording. This is due to static electricity generated by the friction between the rubber roll used for conveyance and the plastic card. In some cases, it reaches a voltage of several thousand volts and is discharged, which may destroy the IC chip.

  The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 constitutes an optically variable device in an IC card having at least an optically variable device (OVD) on a substrate. It is an IC card in which a conductive layer having conductivity is formed on a part of the layer.

The invention according to claim 2 is the IC card according to claim 1, wherein the conductive layer is formed with a surface resistivity of 10 ¹¹ Ω or less.

  According to a third aspect of the present invention, there is provided an optical variable device transfer foil characterized by having at least a release layer, an optical variable layer, an adhesive layer, and a conductive layer between any of the layers on a support.

The invention according to claim 4 is the optical variable device transfer foil according to claim 3, wherein the conductive layer is formed with a surface resistivity of 10 ¹¹ Ω or less.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a diagram showing a configuration of an IC card of the present invention, and FIG. 2 is a cross-sectional view showing an embodiment of an OVD transfer foil of the present invention. As shown in the figure, the IC card according to the present invention comprises at least an IC part 10 and an optically variable device on a substrate 11, and this optically variable device has an optically variable layer 4 and a conductive layer 3. It is possible to appropriately select and provide a protective layer 2 as shown, an adhesive layer that promotes adhesion between layers, and an adhesive anchor layer.

  Hereinafter, the configuration of the IC card of the present invention in FIG. 1 will be described in detail.

  The protective layer 2 is formed on the outermost surface of the card on the IC card, and has a function of protecting the card from rubbing and chemicals. As a material, a conventionally known resin can be used, and an acrylic resin, a polyester resin In addition, known polymer materials such as an ultraviolet curable resin and a thermosetting resin can be used as well as thermoplastic resins such as urethane resin, vinyl chloride-vinyl acetate copolymer resin, and epoxy resin.

  The composition of the protective layer 2 needs to be a material having sufficient adhesion in consideration of compatibility with the upper conductive layer 3 when foil is formed. The protective layer 2 is preferably a material having high mechanical strength, friction resistance, and chemical resistance. Furthermore, it is also possible to add waxes or metal soaps as a lubricant component for improving the friction resistance.

The conductive layer 3 is a layer that plays an important role in the present invention, and is a layer that functions as a conductive layer for releasing generated static electricity. As the conductive material, conventionally known inorganic conductive materials and organic conductive materials can be used. Particularly preferred is a conductive material with weak coloring power. For example, inorganic materials such as tin oxide, antimony-added tin oxide, indium-added tin oxide, zinc antimonate, and antimony pentoxide can be used. Organic polymer materials such as polythiazyl series, polyacetylene series, polyvinylol series, polyaniline series, polythiophene series, polyphenylene vinylene series, quaternary ammonium salt copolymer acrylic series can be used.

  In addition, a conductive material having a strong coloring power can be used as long as it does not affect the printed pattern that comes to the base. For example, a conductive material such as carbon black, copper sulfide, or zinc oxide can be used.

  The conductive material may be used alone, but is preferably added to or mixed with an appropriate resin material. As this resin material, conventionally known acrylic resins, polyester resins, urethane resins, vinyl chloride-vinyl acetate copolymer resins, epoxy resins and other thermoplastic resins, ultraviolet curable resins, thermosetting resins and the like are known. The polymer material can be used.

  The mixing ratio of the above-described conductive material and resin material is arbitrary, and it is desirable to set it appropriately in consideration of required conductivity, processability, mechanical strength, adhesion strength, chemical resistance, storage stability, and the like.

  As a method for providing the conductive layer 3, conventionally known printing methods and coating methods can be used. For example, a gravure printing method, a screen printing method, an offset printing method, a flexographic printing method, a roll coating method, a micro gravure coating method, A die coating method, a curtain coating method, a spin coating method, or the like can be used.

The thickness of the conductive layer 3 is arbitrary, and any thickness can be used as long as the required conductivity is obtained. The required conductivity is that the surface resistivity is 10 ¹¹ Ω or less, and if it is within this range, electrostatic failure can be prevented when transferred onto an IC card.

  Next, the optical variable layer 4 will be described.

  An optical variable device (OVD) having an optical variable effect by the optical variable layer is an image using interference of light, and is a display body that generates a color shift in which the color changes depending on the representation of a stereoscopic image and the viewing angle. Among them, examples of the optical variable device (OVD) such as a hologram and a diffraction grating include a relief type that records light interference fringes as a fine uneven pattern on a plane and a volume type that records interference fringes in a volume direction. On the other hand, a multilayer film system in which a thin film made of ceramics or a metal material having different optical characteristics and a method different from that of a hologram or a diffraction grating is laminated to cause a color change (color shift) depending on the viewing angle is an example.

  Among these optically variable devices (OVD), when considering mass productivity and cost, a relief type hologram (diffraction grating) or a multilayer thin film type is preferable. Generally, these optically variable devices (OVD) are widely used. ing.

  Relief-type holograms (diffraction gratings) are produced by producing a relief-type master plate consisting of fine concavo-convex patterns by an optical photographing method, and mass-producing them on nickel press plates in which the patterns are duplicated by electroplating. That is, this press plate is heated and pressed against the optical variable device (OVD) forming layer 4a (FIG. 2) to replicate the uneven pattern.

  The optical variable device (OVD) forming layer 4a is required to be capable of being molded by a press plate, and the material thereof may be any of a thermoplastic resin, a thermosetting resin, an ultraviolet ray, or an electron beam curable resin. good. For example, thermoplastic resins such as acrylic resins, epoxy resins, cellulose resins, and vinyl resins, thermosetting resins, ultraviolet rays, or electron beam curable resins may be used alone or in combination. Other than the above materials, any known material capable of forming an optically variable device (OVD) image can be used.

  Examples of these image technologies include 3D holograms that reproduce a three-dimensional image, and imaging technologies such as a grating image that expresses a diffractive grating with fine dots and gives high brightness. Recently, a method of forming minute dots of a diffraction grating with a specific shape such as a star shape, a method of drawing fine characters that cannot be seen with the naked eye, called micro characters, and a faithful reproduction of the color of a subject like a photograph Have been developed, a technique called changing that expresses a plurality of images that are completely different depending on the viewing angle, a technique of forming a saw blade shape called a blazed grating with high light diffraction efficiency, etc. Not only the expression method but also any known image expression method can be used.

  The optical variable effect layer 4b is made of a material having a refractive index different from that of the polymer material constituting the relief surface in order to increase the diffraction efficiency of the optical variable device (OVD) image. In addition, the anti-counterfeit medium of the present invention is a medium that emits specific light and observes light emission at the time of verification. Therefore, it is necessary to provide a light-transmitting material or a structure that partially transmits light. is there.

As a material to be used, a high refractive index material such as TiO ₂ , Si ₂ O ₃ , SiO, Fe ₂ O ₃ , ZnS, which is different in refractive index from the optical variable device (OVD) forming layer 2 a and transparent, and more reflective is used. Examples thereof include metal materials such as Al, Sn, Cr, Ni, Cu, and Au, which are highly effective. When these metal materials are used, the conductive layer 3 can also be used.

  Furthermore, although the optical variable effect layer 4b may be provided on one side, it is formed with a pattern having information such as pictures, numbers, characters, etc., improving design and making processing more complicated, and higher forgery prevention An effect can be imparted.

  As the method, 1) a method in which a soluble resin is formed in a pattern on an optical variable device (OVD) formation layer, a metal thin film is provided, and then the soluble resin and the metal thin film layer in that portion are washed and removed; 2) A method of etching a metal thin film with an acid or alkali after printing a pattern on the metal thin film layer using an acid-resistant or alkali-resistant resin, and 3) a resin that dissolves or becomes difficult to dissolve when exposed to light. After applying the material, exposing it through a mask with the desired pattern, and then removing unnecessary parts by cleaning or etching. 4) Partially printing the atomized optical variable device (OVD) forming layer material using various printing techniques. And the like. The above is an example, and the present invention is not limited to these. Any known technique for partially forming a metal thin film can be used as appropriate.

  On the other hand, when the multilayer thin film method is used, as described above, the optical variable layer is composed of a large number of thin film layers having different optical suitability, and is formed as a metal thin film, a ceramic thin film, or a composite thin film formed by combining them. For example, when thin films having different refractive indexes are stacked, a high refractive index thin film and a low refractive index thin film may be combined, or a specific combination may be stacked alternately. The material is appropriately selected on the basis of optical properties such as refractive index, reflectance, and transmittance, weather resistance, interlayer adhesion, and the like, and a desired multilayer thin film can be obtained by a combination thereof. As a forming means, a normal vacuum deposition method or sputtering method capable of controlling the film thickness, film forming speed, number of layers, or optical film thickness (= n · d, n: refractive index, d: film thickness), etc. However, any known means can be used as appropriate, and the method is not limited thereto. Even in the multilayer thin film method, as described in the example of the hologram and diffraction grating above, by forming a part with an information pattern such as an arbitrary pattern, figure, letter, number, etc. It is also possible to provide an information pattern.

  Next, the transfer foil that makes it possible to easily manufacture the anti-counterfeit medium of the present invention shown in FIG. 2 will be described. As shown in the figure, the transfer foil of the present invention is obtained by sequentially laminating a peeling protective layer 5, a conductive layer 3, an optical variable layer 4, and an adhesive layer 6 on a support 11.

  If this transfer foil is used, it becomes possible to form the forgery prevention body of this invention in arbitrary shapes using a hot stamp or a heat roll. That is, after bonding the base material and the adhesive layer with heat and pressure, the unnecessary support 11 is peeled off and formed. Therefore, the peeling protection layer 5 is a layer that is peeled off from the support 11, and also serves to protect the optical variable layer thereafter. The adhesive layer 6 has a function of adhering to the substrate 1 with heat and pressure. These support 11, release protective layer 5, and adhesive layer 6 can be used by appropriately selecting materials and methods used for manufacturing known transfer foils.

  As an example, a manufacturing method using the optical variable device (OVD) transfer foil of FIG. 2 will be described in detail.

  As the substrate 11, a transparent polyethylene terephthalate film (Lumirror 25F65 manufactured by Toray Industries, Inc.) having a thickness of 25 μm was used. On this, the ink in the composition of the following peeling layer protective layer (5) ink was provided with a thickness of 1 μm by the gravure method.

<Ink for peeling protective layer>
-15 parts by weight of acrylic resin-2 parts by weight of wax dispersion-40 parts by weight of toluene-43 parts by weight of methyl ethyl ketone Next, on this, the ink for the conductive layer (3) in the composition described below is formed in a thickness of 1 μm by the gravure method. Provided. The surface resistivity of this conductive resin was 10 ⁹ Ω.

<Ink for conductive layer>
-Conductive resin Jurimer SP-50TF (manufactured by Nippon Pure Chemicals Co., Ltd.) 100 parts by weight Further, an optical variable device (OVD) forming layer (4a) having the following composition is 1 μm by the gravure method, optical variable effect layer (4b) ) ₂ was formed by vacuum deposition, and then a rainbow hologram pattern was formed by pressing a relief rainbow hologram stamper heated to 140 ° C. using a roll embossing method.

<OVD formation layer>
Polyester 20 parts by weight HMDI (hexamethylene diisocyanate) 5 parts by weight MEK (methyl ethyl ketone) 50 parts by weight Further, an ink for an adhesive layer (6) having the following composition was provided thereon with a thickness of 1 μm by a gravure method.

<Ink for adhesive layer>
・ Acrylic resin 10 parts by weight ・ Vinyl chloride resin 5 parts by weight ・ Toluene 40 parts by weight ・ Methyl ethyl ketone 45 parts by weight The thickness of the optical variable device (OVD) transfer foil obtained as described above was subjected to pattern printing in advance. A card on which an optically variable device (OVD) is formed by overlapping a 76 mm vinyl chloride card and heating it at 120 ° C. at a rate of 10 m / min after peeling off the support (11) from the surface. Obtained. Thereafter, a hole corresponding to the shape of the IC module (10) was formed on the surface provided with the optically variable device (OVD) of the vinyl chloride sheet, and the module was fixed with an adhesive to obtain an IC card.

<Comparative Example 1>
As a comparative example, a card without a conductive layer was created. The materials other than the conductive layer were the same as in the examples. Table 1 shows the evaluation results of Examples and Comparative Examples.

  An object of the present invention is to provide a latent image keeping display method such as visualization, a true / false determination method, and an information transmission method used in the authentication field of securities media and product packages.

  As can be seen from Table 1, the comparative example having no conductive layer on the IC card has no antistatic property, and communication is not possible during the conveyance test.

  On the other hand, such a problem does not occur in the embodiment. Therefore, it can be seen that the IC card according to the present invention is superior to the prior art.

It is sectional drawing which shows the structure of the IC card of this invention. It is sectional drawing which shows one Example of the optical variable device (OVD) transfer foil of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Protective layer 3 Conductive layer 4 Optical variable layer 4a Optical variable device (OVD) formation layer 4b Optical variable effect layer 10 IC module 11 Support body 5 Peeling protective layer 6 Adhesive layer

Claims (4)

  An IC card having at least an optically variable device (OVD) on a substrate, wherein an electrically conductive layer is formed on a part of a layer constituting the optically variable device. 2. The IC card according to claim 1, wherein the conductive layer is formed with a surface resistivity of 10 < ¹¹ > [Omega] or less.   1. An optical variable device transfer foil comprising a support having at least a release layer, an optical variable layer, an adhesive layer, and a conductive layer between any of the layers. 4. The optical variable device transfer foil according to claim 3, wherein the conductive layer is formed with a surface resistivity of 10 < ¹¹ > [Omega] or less.

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