JP2005246658A - Secret information medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secret information medium having secret information, in which ordinarily information to be secret is hidden under an unvisually recognizable state and, when the secret information wants to be turned into a visually recognizable state, the hiding properties of a hidden portion are vanished by heating the hidden portion so as to bring the secret information under the hidden portion to a visually recognizable state. <P>SOLUTION: In this secret information medium 1, at least a low melting metal thin film layer 12 having hiding properties is so constituted as to be stacked on one side of a transparent base material 11, on the other side of which an information layer 14 having secret information therein and a hiding layer 15 for visually unrecognizably hiding the information layer 14 are so constituted as to be stacked in the relative order named. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the present invention, information that should normally be kept secret is concealed in an invisible state, but when making secret information visible, the concealed part is heated to conceal it. It is related with the secret information medium which has the secret information which made it possible to visually recognize the secret information recorded under it.

  Confidential information media with confidential information such as member's unique information and personal identification number are, for example, prepaid cards, ID cards that prove their identity, membership cards, cash cards with monetary value, cards such as credit cards, commuter pass It is used as a coupon ticket in many fields, and the number of tickets used is steadily increasing.

  On these cards, value information, identification information, etc. are printed or printed and displayed as pattern or character information, etc., or a magnetic recording unit or optical recording unit provided on the base material, and in some cases as machine reading information on an IC chip It is recorded and can be used for various purposes.

  A prepaid card, which is a kind of the above-described card, pays a certain amount of money in advance so that a service corresponding to the amount can be used, and is widely used as a telephone card, a highway card, or the like.

  On the other hand, a conventional telephone card, which is a kind of prepaid card, has value information, identification information, etc. recorded on the card itself, and anyone can use it to make a call for the amount used. Can be done. For such a conventional telephone card, recently, a random number is printed on the card and the portion is concealed with a concealing material, while value data corresponding to the number is stored on a computer host. A so-called scratch that allows the card user to make a call for the amount used when accessing the host using the number obtained by scraping the concealed part and checking the number afterwards. Off-type telephone cards are in practical use, and the number of cards issued is increasing.

  This type of scratch-off prepaid card has been widely used as a prepaid card for allocating a unique code as secret information to a purchaser, a prepaid card for international calls, etc., but the number (identification information) is divided. Can be used even by a malicious third party, the number is concealed so that the number is not easily stolen, and the concealed number can be confirmed by scraping the concealed part. (For example, refer to Patent Document 1).

However, these concealment parts are provided in a state where they can be peeled off by, for example, silver rubber concealment ink in which aluminum powder is dispersed as a concealment pigment. After that, there is a problem that it is relatively easy to conceal in a state almost the same as before the scraping using the same type of concealing ink as the rubber-based concealing ink so that no trace of fraud is left. .
JP 2002-234286 A

  The present invention has been made paying attention to the above problems, and the secret information recorded is usually concealed in an invisible state, and when the secret information is confirmed, a concealment layer is used. By removing the concealment property of the product by heating, the confidential information underneath can be made visible, and it is difficult to falsify or perform other frauds. The purpose is to provide a secret information medium that facilitates discovery.

  In order to achieve the above problems, the invention according to claim 1 is characterized in that at least one low-melting-point metal thin film layer having a concealing property is laminated on one surface of a substrate having transparency, A secret characterized in that an information layer having secret information and a concealing layer for concealing the information layer in an invisible state are stacked at least in this relative order on the other surface of the substrate. It is an information medium.

  The invention described in claim 2 is characterized in that, in the secret information medium described in claim 1, a protective layer having transparency is further laminated on the low melting point metal thin film layer.

  Furthermore, the invention according to claim 3 is the secret information medium according to claim 1 or 2, wherein the concealing layer has light reflectivity.

  The secret information medium of the present invention can securely conceal the secret information, and when necessary, the secret information that has been concealed can be easily visualized. It is difficult to reconstruct the concealed part after obtaining the information, and it becomes easy to discover whether or not tampering has occurred and to find fraud.

  The present invention will be described below with reference to embodiments shown in the drawings. FIG. 2 is an explanatory diagram showing a planar state in one embodiment of the secret information medium of the present invention, and FIG. 1 is an explanatory diagram showing a schematic cross-sectional configuration along the line XX ′ of the forgery prevention medium shown in FIG. It is. FIG. 3 is an explanatory diagram showing a state when the secret information is visible and visible in the secret information medium of the present invention.

  As shown in FIG. 1, the secret information medium 1 of the present invention includes a transparent low-melting-point metal thin film layer 12, a transparent protective layer 13 and a picture layer 16 on one surface of a transparent substrate 11. Are sequentially provided, and on the other side, an information layer 14 having a secret information and a concealing layer 15 are provided.

  The low-melting-point metal thin film layer 12 is a layer in which the secret information recorded in the information layer 14 located therebelow is normally concealed so that the secret information can be visually recognized when necessary. Unlike conventional concealing layers having a peeling (scratch-off) property composed of concealing ink, for example, it is a layer having concealing properties composed of a thin film of a low melting point metal such as tin, selenium, and indium. Most preferred.

  When the low melting point metal thin film layer 12 made of such a low melting point metal is selectively heated with a thermal head or the like so as to have a temperature equal to or higher than the melting point, the portion melts and the concealability is lost, and the transparent base is lost. The secret information of the information layer 14 can be visually recognized through the material 11.

The low melting point metal thin film layer 12 may be provided directly on one surface of the substrate 11 by a vapor deposition method, or may be provided by a vapor deposition method after providing a primer layer. If it is thin enough to be melted to visualize the secret information, it is difficult to completely hide the information layer 14. Therefore, as shown in the figure, in the secret information medium 1 of the present invention, a transparent base material 11 is interposed between the information layer 14 to be concealed and the low-melting-point metal thin film layer 12 so as to form a gap. And the information layer 14 below the low melting point metal thin film layer 12 is made invisible. In order to secure the desired gap and ensure the concealment property, the thickness of the substrate 11 may be set to about 10 μm to 100 μm.

  The protective layer 13 on the low-melting-point metal thin film layer 12 is provided to improve friction resistance, weather resistance, etc., and to improve heat resistance against the thermal head when taking in and out of the machine. Acrylic resin, vinyl chloride resin, What is necessary is just to form by printing methods, such as an appropriate coating method, a screen printing method, and a gravure printing method, with thin film forming materials, such as a coating liquid which melt | dissolved resin, such as polyester resin and nitrocellulose, in solvents, such as toluene and xylene.

  On the other hand, the information layer 14 is a layer provided with at least secret information for providing only to an appropriate holder of a secret information medium for the purpose of providing a service or the like. It is provided on the surface opposite to the surface on which the low melting point metal thin film layer 12 is formed.

  The information layer 14 may be provided directly on the surface of the substrate 11 as an information pattern such as letters, symbols, numbers, and figures using ink. An information sheet may be provided, and an information sheet provided with a concealing layer to be described later may be provided on the other surface by laminating the information pattern formation surface in contact with the surface of the substrate 11.

  On the other hand, the concealment layer 15 is a layer provided so that the contents of the information layer 14 provided on one surface side of the base material 11 cannot be visually recognized, and is formed of a highly concealing printing ink or thin film forming material. The This layer has a concealing property, and it is sufficient that the lower information layer 14 is concealed in an invisible state. In order to make the concealing property more reliable, an aluminum paste is used. It is preferable to make it the layer comprised with the silver ink etc. which contain. Even if the concealing layer has good concealment properties, an atmosphere that seems to have an information pattern at the bottom is often felt, but there is no problem if the thickness is increased. Further, when silver ink containing aluminum paste is used, it can be concealed without increasing the thickness so much.

  In the secret information medium having such a configuration, the heated portion of the low melting point metal thin film layer 12 is melted, and the covering state by the thin film disappears in the portion, so that the concealing property is lost, as shown in FIG. The exposed portion 21 is formed at that portion, and the information layer 14 concealed at the bottom appears, and the contents of the secret information can be visually recognized.

  However, if the shape of the exposed portion is only a simple shape such as a square or a triangle, the low melting point metal thin film layer 12 is scraped off with a template and a cutter, etc., and the secret information is illegally obtained. There is a possibility that fraud and tampering may occur due to restoration by imitating. Therefore, it is more preferable to set the shape of the low-melting-point metal thin film layer to a complicated shape so that subsequent repair is difficult even if an illegal operation by scraping is performed. Examples of the present invention will be described below.

  After using a transparent polyethylene terephthalate film substrate having a thickness of 188 μm as a substrate having transparency, and providing an adhesive anchor layer (polyester resin) with a thickness of 3 μm on one surface by a gravure coating method, A low melting point metal thin film layer made of Sn (melting point: 230 ° C.) was formed thereon with a thickness of 100 nm by vapor deposition.

Further thereon, a protective layer having a thickness of 3 μm made of an acrylic resin (containing a wax-based active agent) was provided by a gravure coating method, and a pattern layer made of an offset ink was provided by an offset printing method.

  Next, an ink-jet image receiving layer having a thickness of 15 μm is provided on the opposite side of the transparent substrate by a gravure printing method, and then pre-programmed game information is inverted by an ink-jet printer (mirror surface). The information layer was formed by printing.

  Finally, a solid layer made of silver ink (“SS6K + aluminum paste” manufactured by Toyo Ink Co., Ltd.) is printed on the information layer by a screen printing method to form a light-reflective concealing layer (the film thickness after drying is 10 μm). ), A secret information medium capable of opening the concealment information irreversibly by heating was obtained.

  When the obtained confidential information medium was inserted into a heating device with a built-in thermal printer and a predetermined portion on the protective layer forming surface side was heated, the portion of the low melting point metal thin film layer corresponding to the heated portion was melted, and the square An exposed part of the shape appeared, and the information layer concealed in the lower part can be visually confirmed.

It is explanatory drawing which shows the general | schematic cross-section structure of the secret information medium of this invention. It is explanatory drawing which shows the state of the rough plane of the secret information medium of this invention. It is explanatory drawing which shows a state when the secret information of the secret information medium of this invention is visible.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Secret information medium 11 ... Base material 12 ... Low melting-point metal thin film layer 13 ... Protective layer 14 ... Information layer 15 ... Concealing layer 16 ... Pattern layer 21 ... Exposed part

Claims (3)

  A transparent low-melting-point metal thin film layer is laminated on at least one surface of the transparent substrate, and an information layer having secret information and the information layer are visually recognized on the other surface of the substrate. A secret information medium characterized in that a concealing layer for concealing in an impossible state is laminated at least in this relative order.   The secret information medium according to claim 1, wherein a protective layer having transparency is further laminated on the low melting point metal thin film layer.   The secret information medium according to claim 1, wherein the concealing layer has light reflectivity.

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