JP2021092880A - Copy prevention card - Google Patents

Abstract

To provide a copy prevention card that enables highly accurate reading of code information and makes it difficult for a copying machine to copy the code information.SOLUTION: A copy prevention card 10 is a card formed by stacking an over-sheet 13 on an outer surface side of a core sheet 11. Code information 31 is formed on an outer surface side of the over-sheet 13 by an infrared absorbing ink. On the outer surface side of the core sheet 11, a colored layer 32 colored with a predetermined color is formed at a position where at least a part overlaps with the code information 31, in a surface direction of the card. The colored layer 32 is formed by an infrared transmissive ink.SELECTED DRAWING: Figure 1

Description

The present invention relates to a copy protection card for preventing copying of information formed on a surface.

Conventionally, a card capable of recording information has been known. Such cards are used for membership cards and other identification cards, etc., and are used to prove the legitimacy of the person in possession. There are various modes of recording information on the card, such as those using magnetic tape, those using RFID, and those in which code information is formed on the surface.

Above all, code information such as a one-dimensional code bar code and a two-dimensional code QR code (registered trademark) can be formed by printing on the card surface, so that it can be manufactured at low cost. Yes, it is widely used. However, when the code information is formed by simple printing, it can be duplicated relatively easily, and unauthorized use has become a problem.

In order to prevent duplication of code information, a duplication prevention two-dimensional code in which a part of the two-dimensional code is printed with infrared absorbing ink and the other part is printed by a printer has also been proposed (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-4024

However, in the above-mentioned conventional technique, since printing and printing are performed by different means in different parts of one two-dimensional code, it is necessary to accurately align the two, and when the misalignment is large, it is correct. There is a problem that reading is not performed.

Therefore, it is an object of the present invention to provide a copy prevention card that enables highly accurate reading of code information and makes it difficult for a copying machine to copy the code information.

In order to solve the above problems, in the present invention,
A card formed by stacking oversheets on the outer surface side of the core sheet.
Code information is formed on the outer surface side of the oversheet by infrared absorbing ink.
On the outer surface side of the core sheet, a colored layer colored with a predetermined color is formed at a position where at least a part overlaps with the code information in the surface direction of the card.
Provided is a copy protection card characterized in that the colored layer is formed of an infrared transmissive ink.

Further, the copy protection card according to the present invention is
The infrared transmissive ink is characterized in that it is an ink produced by mixing three colors of inks of yellow, red, and indigo.

Further, the copy protection card according to the present invention is
The code information is a two-dimensional code having a positioning mark, and the colored layer is formed at a position overlapping a part of the positioning mark of the two-dimensional code.

According to the present invention, it is possible to provide a copy prevention card that enables highly accurate reading of code information and makes it difficult for a copying machine to copy the code information.

It is a figure which shows the structure of the copy protection card which concerns on 1st Embodiment of this invention. It is a figure which shows each layer before the press of the copy protection card which concerns on 1st Embodiment. It is a figure which shows the state which is actually seen when viewed from the front surface side (oversheet 13 side) in the copy prevention card 10 of 1st Embodiment. It is a figure which shows the paper surface of the copy paper which copied the front surface side in the copy prevention card 10 of 1st Embodiment. It is a figure which shows the structure of the copy protection card which concerns on 2nd Embodiment of this invention. It is a figure which shows each layer before the press of the copy protection card which concerns on 2nd Embodiment. It is a figure which shows the copy paper which copied the front surface side in the copy prevention card of 2nd Embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
<1. First Embodiment>
<1.1. Copy protection card structure>
FIG. 1 is a diagram showing a structure of a copy protection card according to the first embodiment of the present invention. Of these, FIG. 1A is a plan view of the copy protection card 10 as viewed from the front surface side, and FIG. 1B is a cross-sectional view corresponding to line AA in FIG. 1A. Is.

In FIG. 1, 10 is a copy protection card, 11 and 12 are core sheets, 13 and 14 are oversheets, 31 is code information, and 32 is a colored layer. In the example of FIG. 1A, the copy protection card 10 is shown in a plain state except for the area where the code information 31 and the colored layer 32 are present when viewed from the front surface side. Can print various information such as characters and patterns. The size of the copy protection card 10 can be set as appropriate, but for example, it can be a size generally specified by (ISO / IEC7810) or JIS (JISX6301). Specifically, for example, the length of the long side (horizontal direction in FIG. 1 (a)) may be 85.60 mm, and the length of the short side (vertical direction in FIG. 1 (a)) may be 53.98 mm. it can.

The copy protection card 10 of the present embodiment can be used for cards such as cash cards, point cards, credit cards, and ID cards. The card holder and the like can be identified by the identification information recorded in the code information. Further, the presence of the colored layer 32 makes it difficult to copy the code information 31, which has effects such as forgery prevention and unauthorized copy prevention.

In the cross-sectional view of FIG. 1 (b), for convenience of explanation, the thickness of each layer (vertical direction of FIG. 1 (b)) is drawn larger than the size of the copy protection card 10 (horizontal direction of FIG. 1 (b)). However, since the copy protection card 10 is in the shape of a card or a sheet, in reality, each layer is formed thinner. For example, the width of the copy protection card 10 (horizontal direction in FIG. 1) is several cm to several tens of cm, whereas the thickness of the copy protection card 10 (vertical direction in the drawing in FIG. It is about several tens of μm to several hundreds of μm. In the layer configuration shown in the cross-sectional view of FIG. 1B, there is actually no distinction between upper and lower layers, but for convenience of explanation, the upper layer of the drawing (code information 31 side: front surface side) is the upper layer, and the lower side of the drawing (over). The sheet 14 side: the back surface side) will be expressed as the lower layer. Therefore, in FIG. 1B, the top layer is the code information 31 and the bottom layer is the oversheet 14. Further, in the present specification, the surface having the code information 31 as shown in FIG. 1A will be described as the front surface, and the oversheet 14 side, which is the other surface, will be described as the back surface. May be defined as either the front side and the back side.

As shown in the cross-sectional view of FIG. 1B, the copy protection card 10 has a structure in which two core sheets 11 and 12 are used as a central layer, and oversheets 13 and 14 are laminated on both sides thereof. The core sheet may be a single layer, but if two layers are used for printing on both the front and back surfaces, it may be easier to manufacture. In this embodiment, white core sheets 11 and 12 are used, and transparent oversheets 13 and 14 are used.

A black colored layer 32 is formed on the 11th surface of the core sheet in contact with the oversheet 13. Specifically, the colored layer 32 is formed by silk screen printing using an infrared transmissive ink. In the present embodiment, in order to express black color with the infrared transmissive ink, three colors of yellow (Y: yellow), red (M: magenta), and indigo (C: cyan) are mixed as the infrared transmissive ink. The generated ink is used. The three colors of yellow, red, and indigo ink can form a colored layer 32 that is apparently black and transmits infrared rays.

Code information 31 is formed on the outer surface side (front surface side: upper side in FIG. 1B) of the oversheet 13. Specifically, the code information 31 is formed by offset printing using infrared absorbing ink. The oversheet 13 is sandwiched between the code information 31 and the colored layer 32. In general, printing directly above the ink is poorly fixed, causing problems such as reproducibility of code information. In the copy protection card of the present embodiment, since the oversheet 13 is sandwiched between the code information 31 and the colored layer 32, the code information 31 and the colored layer 32 can be separated. The code information 31 is preferably individual information that differs for each card. The code information 31 is formed at a position where at least a part of the colored layer 32 overlaps. The code information 31 and the colored layer 32 can be formed by a known printing method such as offset printing, gravure printing, screen printing, inkjet printing, and electrophotographic printing.

In this embodiment, a QR code, which is a two-dimensional code, is used as the code information 31. At the three corners of the two-dimensional code, positioning marks are formed in which a black square is surrounded by a black rectangular frame. In the present embodiment, the colored layer 32 is formed at a position overlapping at least a part of the positioning mark. As a result, the colored layer 32 acts so as not to function a part of the positioning mark at the time of copying, which makes it difficult to copy the code information 31.

Further, in the example of FIG. 1A, the parts other than the code information 31 and the portion where the colored layer 32 is formed are in a plain state, and the pattern or the like is omitted. Is visible. Printing for forming the print layer can be performed by a known printing method such as offset printing, gravure printing, screen printing, and inkjet printing.

As shown in FIG. 1 (b), the cross-sectional structure of the copy protection card 10 is composed of oversheets 13 and 14 laminated on both sides of the core sheets 11 and 12, respectively, and is formed on the exposed surface of one of the oversheets 13. The code information 31 is provided. A colored layer 32 is provided on the side of the core sheet 11 facing the oversheet 13. The core sheet of the copy protection card 10 may be a single layer, or may have two or more layers. The core sheets 11, 12, and the oversheets 13 and 14 constituting the copy protection card 10 are preferably plastic sheets, and the resin that can be used for the plastic sheets is not particularly limited as long as it is a thermoplastic resin having rigidity and excellent strength. However, a copolymerized polyester resin such as polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, PET-G, ABS resin and the like can be used. A transparent plastic sheet is used for the oversheets 13 and 14, and a core sheet 11 and 12 colored white or solid-printed (entirely printed) on the white-colored one is usually used. Further, in the case of applications such as cash cards and credit cards, IC chips and magnetic tapes may be provided at predetermined positions.

<1.2. Copy protection card manufacturing method>
Next, a method of manufacturing a copy protection card will be described. First, a black colored layer 32 is formed by silk screen printing on the side of the core sheet 11 that is to be in contact with the oversheet 13. FIG. 2 is a diagram showing each layer of the copy protection card before pressing. After forming the colored layer 32, as shown in FIG. 2, the core sheets 11 and 12 as the central layer and the transparent oversheets 13 and 14 are integrally laminated and inserted into a press machine, sandwiched between mirror plates and heated. And press with pressure. When the core sheet and the oversheet are heat-fused materials such as polyvinyl chloride and PET-G, they are fused without using an adhesive material between the sheets, but in the case of a non-heat-fused sheet material. Is hot-pressed with a hot-melt adhesive or the like.

Next, the code information 31 is formed on the outer surface side (upper layer side) of the oversheet 13 by the infrared absorbing ink. The code information 31 is formed on the outer surface side of the core sheet at a position where at least a part of the colored layer 32 overlaps with the surface direction of the card. As a result, the code information 31 and the colored layer 32 are formed at positions where at least a part of them overlap. When viewed from the colored layer 32, the colored layer 32 is formed at a position where at least a part of the code information 31 overlaps.

In the copy protection card 10 thus obtained, the relationship between the code information 31 and the colored layer 32 is as shown in FIG. 1A when viewed from the front surface side (oversheet 13 side). .. FIG. 3 is a diagram showing a state in which the copy protection card 10 is actually visible when viewed from the front surface side (oversheet 13 side). Although the colored layer 32 is on the back side of the oversheet 13, the code information 31 is hidden by the colored layer 32 as shown in FIG. 3 because the oversheet 13 is transparent and the colored layer 32 is black. appear. Therefore, it is difficult to confirm the code information 31 with the naked eye. Here, the term "transparency" means transparency to the extent that the configuration of the code information 31 in the portion where the code information 31 and the colored layer 32 overlap can not be confirmed with the naked eye. In other words, in the visible light region, it means transparency to the extent that light from the colored layer 32 is transmitted to the extent that the configuration of the code information 31 in the portion where the code information 31 and the colored layer 32 overlap cannot be confirmed.

In this state, consider a case where the copy protection card 10 is read from the front surface side with an infrared wavelength code reader. The code reader is provided with an infrared irradiation unit and an infrared light receiving unit inside. Most of the infrared rays emitted from the code reader to the front surface of the copy protection card 10 are absorbed by the printed portion (the portion represented in black in FIG. 3) of the code information 31, and the non-printed portion (in FIG. 3). Most of it is not absorbed in the part expressed in white). The infrared rays transmitted through the non-printed portion of the code information 31 reach the colored layer 32, but do not absorb the infrared rays because the colored layer 32 is formed of the infrared transmitting ink. Therefore, there is a clear difference between the amount of infrared rays absorbed by the printed portion of the code information 31 and the amount of infrared rays reflected by the non-printed portion of the code information 31. Therefore, the image of the code information formed by infrared rays is clearly received by the infrared light receiving unit in the code reader, and the code information can be read. Therefore, the code information can be easily read from the front surface of the copy protection card 10 according to the present embodiment as shown in FIG.

Next, consider a state in which the front surface of the copy protection card 10 is copied by a copying machine (copier). When the front surface of the copy protection card 10 is copied by a copying machine, the front surface of the copy protection card 10 is irradiated with light from the copying machine. Since the light from the copying machine is light having a wavelength close to the visible light region, it is absorbed by the black colored layer 32, and a black square image is obtained in the light receiving portion of the copying machine. FIG. 4 is a diagram showing a copy paper on which the front side of the copy prevention card 10 is copied. FIG. 4A is a front view of the copying paper, and FIG. 4B is a cross-sectional view corresponding to line BB in FIG. 4A. In FIG. 4, 31'is a code information copying portion, 32' is a colored layer copying portion, and 40 is a copying paper.

As shown in FIG. 4A, the colored layer copying portion 32'is in a state of being painted black, as in the case where the copying prevention card 10 is viewed with the naked eye. In the case of copying, as shown in FIG. 4B, an image is formed on the same layer of the copying paper 40 with the same toner. Therefore, on the paper surface of the copying paper 40, the black portion of the code information copying portion 31'and the black portion of the colored layer copying portion 32' have the same infrared absorption characteristics. Therefore, even if the code reader tries to read the code information from the code information copying portion 31', it cannot be read. Therefore, it becomes difficult to copy the front surface of the copy protection card 10 while maintaining the state in which the code information is functioning.

<2. Second embodiment>
<2.1. Copy protection card structure>
Next, the second embodiment will be described.
FIG. 5 is a diagram showing a structure of a copy protection card according to a second embodiment of the present invention. Of these, FIG. 5A is a plan view of the copy protection card 10A as viewed from the front surface side, and FIG. 5B is a cross-sectional view corresponding to line CC in FIG. 5A. Is. The second embodiment is different from the first embodiment in that the protective layer 22, the printing layer 23, and the adhesive layer 24 are formed on the upper layer side of the oversheet 13.

By forming the print layer 23, the design of the card surface can be enhanced. The print layer 23 can be formed by a known printing method such as offset printing, gravure printing, screen printing, and inkjet printing. The protective layer 22, the printing layer 23, and the adhesive layer 24 are generally formed by a transfer method as described later. Although the protective layer 22 is used as a release layer in the transfer material 20, it functions as a protective layer of the copy protection card 10A which is a transfer target after transfer. In FIG. 5, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In the example of FIG. 5A, when viewed from the front side of the copy protection card 10A, the pattern of the print layer 23 is passed through the transparent protective layer 22 in addition to the code information 31 and the colored layer 32 region. Is visible. The print layer 23 enhances the design of the card surface. The print layer 23 can express various information such as characters and patterns. Also in the cross-sectional view of FIG. 5 (b), as in the cross-sectional view of FIG. 1 (b), for convenience of explanation, the thickness of each layer is higher than the size of the copy protection card 10A (in the left-right direction of FIG. 5 (b)). Although the vertical direction in FIG. 5B is drawn large, each layer is actually formed thinner because the copy protection card 10A has a card shape or a sheet shape. For example, the width of the copy protection card 10A (horizontal direction in FIG. 5) is several cm to several tens of cm, whereas the thickness of the copy protection card 10 (vertical direction in the drawing in FIG. 5B) is It is about several tens of μm to several hundreds of μm. In the layer configuration shown in the cross-sectional view of FIG. 5B, there is actually no distinction between upper and lower layers, but for convenience of explanation, the upper side of the drawing (protective layer 22 side: front surface side) is the upper layer, and the lower side of the drawing (over). The sheet 14 side) is expressed as the lower layer. Therefore, in FIG. 5B, the uppermost layer is the protective layer 22, and the lowermost layer is the oversheet 14. Further, the copy protection card 10A shown in FIG. 5 will also be described with the surface having the protective layer 22 as shown in FIG. 5A as the front surface and the other surface, the oversheet 14 side, as the back surface. However, in reality, either side may be the front side and either side may be the back side.

<2.2. Copy protection card manufacturing method>
Next, a method of manufacturing the copy protection card according to the second embodiment will be described. First, a black colored layer 32 is formed by silk screen printing on the side of the core sheet 11 that is to be in contact with the oversheet 13. Next, the code information 31 is formed on the outer surface side (upper layer side) of the oversheet 13 by the infrared absorbing ink. The code information 31 is formed at a position where at least a part of the colored layer 32 overlaps with the colored layer 32 in the surface direction of the card when the code information 31 is overlapped with the core sheet 11. As a result, in the copy protection card 10A, the code information 31 and the colored layer 32 are formed at a position where at least a part thereof overlaps. When viewed from the colored layer 32, the colored layer 32 is formed at a position where at least a part of the code information 31 overlaps.

FIG. 6 is a diagram showing each layer of the copy protection card before pressing. After forming the colored layer 32, as shown in FIG. 6, the core sheets 11 and 12, which are the central layers, the transparent oversheets 13 and 14, and the transfer material 20 of the printing layer 23 are integrally laminated and inserted into the press machine. Then, it is sandwiched between mirror plates and pressed by applying heat and pressure. The transfer material 20 is a material obtained by forming a printing layer 23 on a film base material 21 having excellent flatness such as polyethylene terephthalate (PET) via a protective layer (release layer) 22 and further coating the adhesive layer 24. is there.

This transfer step and the step of integrally heat-sealing the core sheets 11 and 12 and the oversheets 13 and 14 are performed in one heat pressing step. When the core sheet and the oversheet are heat-fused materials such as polyvinyl chloride and PET-G, they are fused without using an adhesive material between the sheets, but in the case of a non-heat-fused sheet material. Is hot-pressed with a hot-melt adhesive or the like.

The transfer material 20 is formed by forming a printing layer 23 on a film base material 21 such as polyethylene terephthalate (“PET”) via a protective layer (release layer) 22. An adhesive layer 24 having a thin layer (thickness of 1 to 2 μm or less) is provided on the contact surface with the oversheet 13. After hot pressing, the film base material 21 of the transfer material 20 is peeled off. The protective layer 22 functions as a release layer during transfer, but also functions as a protective layer by leaving it on the card side after transfer.

In the copy protection card 10A thus obtained, the relationship between the code information 31 and the colored layer 32 is as shown in FIG. 5A when viewed from the front surface side (protective layer 22 side). .. Similar to the copy protection card 10 in the first embodiment, the colored layer 32 is on the back side of the oversheet 13, but since the oversheet 13 is transparent and the colored layer 32 is black, the case shown in FIG. Similarly, the code information 31 appears to be hidden by the colored layer 32. Therefore, it is difficult to confirm the code information 31 with the naked eye.

In this state, when the copy protection card 10A is read from the front surface side with an infrared wavelength code reader, the infrared rays absorbed by the printing unit of the code information 31 are obtained as in the copy protection card 10 in the first embodiment. Since there is a clear difference in the amount of infrared rays reflected by the non-printing portion of the code information 31, the light receiving portion in the code reader clearly receives the image of the code information formed by the infrared rays, and the code information It can be read. Therefore, the code information can be easily read from the front surface of the copy protection card according to the present embodiment as shown in FIG.

Further, when the front surface of the copy protection card 10A is copied by the copying machine, the light from the copying machine is absorbed by the black colored layer 32 as in the copy prevention card 10 in the first embodiment, and the copying machine A black square image is obtained on the light receiving portion. In addition, an image from the print layer 23 can also be obtained. FIG. 7 is a diagram showing a copy paper 40A on which the front side of the copy prevention card 10A is copied. 7 (a) is a front view of the copying paper 40A, and FIG. 7 (b) is a cross-sectional view corresponding to the DD line in FIG. 7 (a). In FIG. 7, 23'is a copy portion of the image of the print layer 23, 31'is a code information copy portion, 32'is a colored layer copy portion, and 40A is a copy paper.

As shown in FIG. 7A, the colored layer copying portion 32'is in a state of being painted black as in the case where the copying prevention card 10A is viewed with the naked eye. In the case of copying, as shown in FIG. 7B, an image is formed on the same layer of the copying paper 40A with the same toner. Therefore, on the paper surface of the copying paper 40A, the black portion of the code information copying portion 31'and the black portion of the colored layer copying portion 32' have the same infrared absorption characteristics. Therefore, even if the code reader tries to read the code information from the code information copying portion 31', it cannot be read. Therefore, it is difficult to copy the front surface of the copy protection card 10A while maintaining the state in which the code information is functioning.

<3. Structure of each layer>
Each layer constituting the copy protection card shown in the first embodiment and the second embodiment will be described. The core sheets 11 and 12 are sheets that serve as a central layer of the copy protection card. As the core sheets 11 and 12, a wide variety of white or colored plastic sheets can be used, and the following single films or composite films thereof can be used. Polyethylene terephthalate (PET), PET-G (terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer), polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polycarbonate, polyamide, polyimide, cellulose diacetate, cellulose triacetate, Polystyrene-based, ABS, polyacrylic acid ester, polypropylene, polyurethane and the like. The film thicknesses of the core sheets 11 and 12 are appropriately selected in consideration of the overall thickness of the copy protection card.

The oversheets 13 and 14 are sheets laminated on both sides of the two core sheets 11 and 12, which are the central layers. As the oversheets 13 and 14, a single film similar to the core sheet or a composite film thereof can be used. If possible, it is preferable to use a material of the same quality as the core sheet. Generally, a transparent material having a thickness of about 0.05 to 0.1 mm is often used.

As the film base material 21 of the transfer material 20, a wide variety of materials such as a plastic film and a paper base material can be used. As the plastic film, the above-mentioned various materials can be used as in the case of the core sheet. As the paper base material, the following can be used. Woodfree paper, coated paper, kraft paper, glassin paper, synthetic paper, latex and melamine impregnated paper.

As the material of the release agent for forming the protective layer 22 that also functions as the release layer, acrylic resin, polyester resin, polyvinyl chloride resin, cellulose resin, rubber resin, polyurethane resin, polyvinyl acetate In addition to based resins, copolymers such as vinyl chloride-vinyl acetate copolymer resin and ethylene-vinyl acetate copolymer resin can be used. When the protective layer 22 needs to be hard, a photocurable resin such as an ultraviolet curable resin, a radiation curable resin such as an electron beam curable resin, or the like can also be used.

The infrared absorbing ink used to form the code information 31 is composed of an infrared absorbing material and a vehicle, and if necessary, a filler, a plasticizer, a dispersant, a lubricant, an antistatic agent, an antioxidant, and a fungicide. Additives such as, may be added, and it may be colorless or colored. These compositions may be dispersed and kneaded, and if necessary, the solid content and viscosity may be adjusted with a solvent to obtain an ink composition. The color may be any color such as cyan, magenta, yellow, red, green, blue, and black, and there is no limitation on the color tone under visible light.

The infrared absorbing material is a substance that absorbs infrared rays, and can be roughly classified into an infrared absorbing pigment and an infrared absorbing dye. It can be roughly divided into a colorless infrared absorbing pigment that absorbs little or no visible light and a colored infrared absorbing pigment having a certain absorption band in the visible region, but the colorless one is expensive and in the present embodiment. Is also applicable to colored pigments, so colored infrared absorbent pigments can also be used for the purpose of reducing manufacturing costs. Typically, carbon black can be used.

As the infrared absorbing pigment, transition metal compounds and complexes such as iron, copper, chromium, cobalt and nickel can be used. For example, a Millory blue pigment, which is an iron complex (iron ferricyanide complex), is preferably used. In addition to using the above compounds alone, two or more of them can be mixed and used. Further, as the infrared absorbing dye, dyes such as polymethine-based (cyanine-based), phthalocyanine-based, naphthoquinone-based, anthraquinone-based, dithiol-based, and triphenylmethane-based dyes can be used.

Infrared-absorbing pigments are superior to infrared-absorbing dyes in terms of light resistance (fading to infrared rays) and the like, and it is preferable to use an inorganic substance such as the above-mentioned metal pigment. In addition, since dyes are generally easily transferred, when an infrared absorbing dye is used, the infrared absorbing material is transferred quickly and the amount is large, so that the function is rapidly deteriorated.

The infrared transmissive ink used for forming the colored layer 32 is a normal yellow (Y: yellow), red (M: magenta), indigo (C: cyan) ink having no absorption in the near infrared region, or a mixed ink thereof. Copper oxide (divalent), manganese oxide (tetravalent), cobalt oxide (trivalent), chromium oxide (trivalent and hexavalent), iron oxide with a bandgap of 0.5 to 1.26 eV with semiconducting properties. Inks in which fine particles such as lead (divalent), lead sulfide, nickel sulfide, and bismuth sulfide are mixed with resins such as acrylic, silicon, and urethane, or inks in which ordinary process Y, M, and C inks are mixed are available. Can be mentioned.

The infrared transmissive ink needs to be colored in the visible light region. The color may be any color such as cyan, magenta, yellow, red, green, and blue as long as it is colored, but it is preferable that the color is the same as or similar to the color in the visible light region of the infrared absorbing ink. When the infrared transmitting ink and the infrared absorbing ink are the same color or similar colors, it is difficult to visually distinguish the infrared transmitting ink from the infrared absorbing ink even if the density of the infrared transmitting ink is a little low, and it is difficult to copy the code information by the copying machine. can do.

As long as the density of the infrared absorbing ink is high to some extent, any color may be used as long as it is colored. Further, when the infrared absorbing ink is black or a color close to black, the density may be relatively low. In any of these cases, it is difficult to visually distinguish the code information from the infrared absorbing ink, so that it is possible to make it difficult to copy the code information by the copying machine.

Preferred infrared transmissive inks include black inks produced by mixing three primary color inks of yellow, magenta, and cyan without using carbon black pigments.

Further, as the infrared transmissive ink, a normal ultraviolet curable process ink or the like containing an infrared transmissive dye such as olazole black or olazole 2RG can be adopted. This ink is also a black ink in appearance.

Further, as a black ink having good resistance to transmitting infrared rays, an ink containing a black pigment as a main component, which is a metal compound, can be used.

The vehicles of the infrared absorbing ink used for forming the code information 31 and the infrared transmitting ink used for forming the colored layer 32 may be the same. Generally, an oxidation polymerization type ink and an ultraviolet curable ink can be applied to the offset printing ink or the silk screen printing ink, but the ultraviolet curable ink is preferable.

Oxidative polymerization type inks are called oil-based inks, which form a film by solidification and insolubilization of vehicles by oxidative polymerization, and dry oil varnish, dry alkyd, etc. fall into this category. Cobalt and manganese are added as oxidation accelerators. Further, if necessary, auxiliary agents such as various reactants for improving drying, viscosity, dispersibility, and durability such as abrasion resistance of the ink surface after printing can be appropriately added.

As the resin forming material of the ultraviolet curable ink, the prepolymer or oligomer is a polyol acrylate type, an epoxy acrylate type, a urethane acrylate type, a polyester acrylate type, an alkyd acrylate type, a polyether acrylate type, etc., and the monomer is a monoacrylate type. , Diacrylate-based, triacrylate-based, and the like.

<4. Example>
<4.1. Example 1>
First, a black colored layer 32 was formed by silk screen printing on the side of the core sheet 11 that was to be in contact with the oversheet 13. The colored layer 32 was formed by silk screen printing using a black ink produced by mixing the three primary color inks of yellow, magenta, and cyan without using a carbon black pigment. Next, a transparent oversheet (thickness 50 μm) made of a homogeneous material is used as a central layer of white core sheets (thickness 360 μm) 11 and 12 made of a non-crystalline polyester resin (trade name “PET-G”). ) 13 and 14 were laminated, introduced into the mirror plate of the press machine, and hot-pressure pressed under the conditions of ^{150 ° C., 25 kg / cm 2, and 15 minutes.}

Next, the code information 31 was formed on the outer surface side (upper layer side) of the oversheet 13 with infrared absorbing ink. The code information 31 was formed by offset printing a black ink containing a carbon black pigment. As a result, the copy protection card 10 having the appearance of the front surface as shown in FIG. 3 was obtained.

The front surface of the obtained copy protection card 10 was copied by a copying machine. As a result, the copying paper 40 as shown in FIG. 4 was obtained.

<4.2. Example 2>
A biaxially stretched PET film having a thickness of 100 μm is gravure-printed as a film base material 21 with a protective layer (peeling layer) 22 of a polyester resin-based thin layer (1 to 2 μm), and a printing layer 23 by silk screen printing is printed on the surface thereof. The provided material was prepared as the transfer material 20. The print layer 23 also serves as an adhesive layer 24.

Then, a black colored layer 32 was formed by silk screen printing on the side of the core sheet 11 that was to be in contact with the oversheet 13. The colored layer 32 was formed by silk screen printing using a black ink produced by mixing the three primary color inks of yellow, magenta, and cyan without using a carbon black pigment. Next, the code information 31 was formed on the outer surface side (upper layer side) of the oversheet 13 with infrared absorbing ink. The code information 31 was formed by offset printing a black ink containing a carbon black pigment.

Next, a transparent oversheet (thickness 50 μm) made of a homogeneous material is used as a central layer of white core sheets (thickness 360 μm) 11 and 12 made of a non-crystalline polyester resin (trade name “PET-G”). ) 13, 14 were laminated, and the transfer material 20 was further laminated, introduced into the mirror plate of the press machine, and hot-pressed under the conditions of ^{150 ° C., 25 kg / cm 2, and 15 minutes.} Then, the film base material 21 was peeled off and the protective layer 22, the printing layer 23, and the adhesive layer 24 were transferred to the card side. As a result, the copy protection card 10A having the appearance of the front surface as shown in FIG. 3 was obtained.

The front surface of the obtained copy protection card 10A was copied by a copying machine. As a result, a copy paper 40A having a paper surface as shown in FIG. 7 was obtained.

The code information 31 formed on the front surface side of the copy protection card 10 obtained in Example 1 and the copy protection card 10A obtained in Example 2 is read and tested by a code reader that receives and emits infrared rays. went. As a result of the reading test, it was possible to satisfactorily read the code information 31 which is partially difficult to see with the naked eye from the front surface side of the copy protection card 10.

Further, the code information printed on the copy paper 40 and the copy paper 40A from the copy protection card 10 obtained in Example 1 and the copy protection card 10A obtained in Example 2 respectively receives and emits infrared rays. A reading test was performed with a code reader. As a result of the reading test, the code information printed on the copy paper, which was partially difficult to see, could not be read.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified in various ways. For example, in the above embodiment, an example in which a QR code which is a two-dimensional code is used as the code information formed by the infrared absorbing ink has been described, but a bar code which is a one-dimensional code and other information can be recorded. Code information may be used.

10, 10A ... Copy protection card 11, 12 ... Core sheet 13, 14 ... Oversheet 20 ... Transfer material 21 ... Film base material 22 ... Protective layer (release layer)
23 ... Printing layer 24 ... Adhesive layer 31 ... Code information 32 ... Colored layer 40, 40A ... Copy paper

Claims (3)

A card formed by stacking oversheets on the outer surface side of the core sheet.
Code information is formed on the outer surface side of the oversheet by infrared absorbing ink.
On the outer surface side of the core sheet, a colored layer colored with a predetermined color is formed at a position where at least a part overlaps with the code information in the surface direction of the card.
A copy protection card characterized in that the colored layer is formed of an infrared transmissive ink. The copy protection card according to claim 1, wherein the infrared transmissive ink is an ink produced by mixing three color inks of yellow, red, and indigo. The code information is a two-dimensional code having a positioning mark, and the colored layer is formed at a position overlapping a part of the positioning mark of the two-dimensional code. The copy protection card according to 1 or 2.

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