JP2000272275A - Magnetic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the security function, and at the same time, improve the durability of the magnetic recording layer by forming a concealed pattern layer on the magnetic recording layer, and laminating a transparent optical diffraction pattern layer on the top of the concealed pattern layer. SOLUTION: On a card base material 10 at one section of the upper surface of which, a magnetic recording layer 2 is laminated, a concealed pattern layer 20 and a transparent optical diffraction layer 30 including an optical refraction layer, are laminated in order, and this magnetic card 1 is prepared. In this case, both of the concealed pattern layer 20 and the transparent optical diffraction pattern layer 30 at least need to be located on the top of the magnetic recording layer 2, but the concealed pattern layer 20 or/and the transparent optical diffraction pattern layer 30 may be laminated on a section without the magnetic recording layer 2. The thickness of the concealed pattern layer 20 is set to be 4-30 μm, and as the magnetic recording layer 2, a layer wherein the strength of a magnetic field is 1.0-2.5 μWb/m is used. Also, a protective layer comprising a hardening compound which is crosslinked and hardened on the transparent optical diffraction pattern layer 30 is provided when required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic card, and more particularly to a magnetic card having an excellent appearance by forming a picture layer and a transparent light diffraction pattern layer on a magnetic recording layer of the magnetic card. Things.

[0002]

2. Description of the Related Art Various cards have been used, including bank cards (or cash cards) used for bank deposits and remittances, and credit cards capable of performing transactions without handling cash based on contracts with credit companies. I have.
Here, the "card" is a size that is almost the size of a business card to be carried, and has ID information and other information by various means, and is used according to each purpose. Refers to something.

[0003] In these cards, when the card is placed horizontally, a magnetic recording layer is provided along the upper side at a position slightly away from the upper side of the card, and the position uses the magnetic recording layer. It is unified so that information can be written and read smoothly. This magnetic recording layer was originally formed by dispersing magnetic iron oxide powder in a paint and applying it directly or by transferring a substance applied to another substrate, and the magnetic iron oxide powder was almost black. Since the magnetic recording layer has a certain color, the appearance of the magnetic recording layer is also black, giving a strong impression on the appearance, which is a constraint on the design design.

Therefore, a color magnetic recording layer having an arbitrary color other than black is formed on the magnetic recording layer, the entire surface of the card including the magnetic recording layer is covered with a colored layer,
A transparent light diffraction pattern layer such as a transparent hologram was formed on a magnetic recording layer. However, in the method of forming a color magnetic recording layer or covering with a colored layer, the colored layer is worn due to friction with a magnetic head when writing / reading information using the magnetic recording layer, and durability is reduced. In addition to being scarce, only adding a colored layer does not make it difficult for a person with a fraudulent intention to forge.
In addition, the method of forming the transparent light diffraction pattern layer on the upper layer gives a specific appearance. On the other hand, although there is an advantage, there is a disadvantage that it is difficult to apply a general design.

[0005]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a magnetic card in which a colored layer is formed with the intention of concealing a magnetic recording layer in the prior art, and the durability of the magnetic card is poor. It is an object of the present invention to solve the problem that the magnetic card in which the transparent light diffraction pattern layer is formed as an upper layer has design restrictions.

[0006]

According to the present invention, a concealed pattern layer is formed on a magnetic recording layer instead of simply forming a colored layer or a transparent light diffraction pattern layer, and further formed thereon. The problem was solved by laminating the transparent light diffraction pattern layers.

According to a first aspect of the present invention, a magnetic recording layer is formed on a part of a card base material, and a concealing pattern layer covering at least the magnetic recording layer and concealing the magnetic recording layer, and a transparent light diffraction pattern layer Are sequentially stacked.

According to a second aspect of the present invention, in the first aspect, the concealment pattern layer has a thickness of 4 to 30 μm, and the magnetic recording layer has a magnetic field strength of 1.0 to 2.5 μWb / m. The present invention relates to a magnetic card characterized by using a magnetic card.

A third aspect of the present invention relates to a magnetic card according to the first aspect, further comprising a protective layer made of a curable compound crosslinked and cured on the transparent light diffraction pattern layer.

[0010]

FIG. 1 is a sectional view showing the most basic structure of a magnetic card 1 according to the present invention. The magnetic card 1 has a magnetic recording layer 2 laminated on a part of its upper surface. The concealment pattern layer 20 and the transparent light diffraction pattern layer 30 are sequentially laminated. In the present invention, both the concealing pattern layer 20 and the transparent light diffraction pattern layer 30 need to be at least on the magnetic recording layer 2, but the concealing pattern layer 20 and / or The transparent light diffraction pattern layer 30 may be laminated. FIG. 2 is a cross-sectional view showing a more preferable structure of the card base 10 of the magnetic card 1 of the present invention, and shows an oversheet 11, core sheets 12 and 12 ', and an oversheet 1 from below.
1 'indicates that the layers are sequentially stacked. FIG. 3 is a cross-sectional view showing a more preferable structure of the concealing pattern layer 20 of the magnetic card 1 of the present invention, and shows a state in which the concealing layer 21 and the picture pattern layer 22 are sequentially stacked from below. FIG. 4 is a sectional view showing a more preferable structure of the transparent light diffraction pattern layer 30 of the magnetic card 1 according to the present invention.
A layer 32 having a transparent light diffraction pattern and a protective layer 33 made of a crosslinked curable polymer are sequentially laminated. The materials constituting each layer, the manufacturing method, and the like will be described below with reference to the drawings.

The card base material 10 does not bend or break when it is carried by the card holder, and has strength and strength that does not hinder running inside a machine used for writing and reading on the magnetic recording layer. Those having rigidity are preferred. As a specific material of the card base material 10, a sheet of synthetic resin such as polyvinyl chloride, polyester, polycarbonate, polyamide, polyimide, cellulose diacetate, cellulose triacetate, polystyrene, polyacrylate, polypropylene, or polyethylene; A metal sheet such as copper, aluminum, or tin, or a cardboard, particularly a resin or latex-impregnated paper is used.

The card base material 10 is a single sheet or a composite of the above-mentioned sheets. The thickness of the sheet of the above-mentioned material constituting the card base material 10 is about 10 μm to 5 mm, but the standard of ISO is 0.76 mm. From the viewpoint of providing the card base material 10 with concealing properties,
A sheet of a synthetic resin into which a concealing pigment is kneaded may be used. As a typical example of the thickness, the material, and the layer configuration, two white polyvinyl chloride resin sheets each having a thickness of 0.28 mm are used as core sheets as shown at 12 and 12 ′ in FIG. The colorless and transparent polyvinyl chloride resin sheets are used one by one as oversheets as shown at 11 and 11 'in FIG.
There is a laminated sheet composed of four layers.

The magnetic recording layer 2 is usually in the form of a stripe having a width of about 6 mm, and is provided directly on the surface of the card substrate 10 by using a coating material prepared by adding and kneading a magnetic substance.
Formed by transfer method using a magnetic recording layer transfer sheet that has been applied to a thin plastic sheet or other base material and cut and pasted in a stripe shape, or has been temporarily laminated to a temporary base material so that it can be peeled off. I do. In addition to using a paint prepared by adding and kneading a magnetic substance, a method of forming a thin film of a magnetic substance in a gas phase state by vapor deposition or sputtering of a magnetic substance to form a magnetic recording layer 2 or a stripe It may be cut and pasted in a shape or applied by transfer. As the magnetic recording layer 2, a known magnetic recording layer can be used. However, since the coercive force is determined to be 52 ± 4 KA / m in JIS X6301 for the identification card with the front surface magnetic stripe at present, 48 ~ 5
Preferably, it is 6 KA / m, and as a specific magnetic material therefor, barium ferrite is preferably used. The magnetic recording layer 2 is formed on the oversheet 11 or 11 ′, and then hot-pressed using a heating press to bury the magnetic recording layer 2 on the surface of the card substrate 10 as shown in FIG. The surface of the magnetic recording layer 2 and the surface of the card substrate 10 are on the same plane without any step. The heat pressing may be performed to form the magnetic recording layer 2, but it is more economical to transfer the concealed pattern layer together with the formation of the magnetic recording layer 2 to prevent the deterioration of the material. It is also preferable in the sense. As will be described later, in the present invention, the concealing pattern layer 20 and the transparent light diffraction pattern layer 30 are formed on the magnetic recording layer 2, so that writing and reading using the magnetic recording layer 2 are performed. However, the gap between the magnetic head and the magnetic head tends to be large, and writing and reading errors are likely to occur. Hiding pattern layer 20,
Preferably, the total thickness of the transparent light diffraction pattern layer 30 is as small as possible, for example, 8 μm or less. However, from the viewpoint of sufficiently exhibiting the performance of the concealing pattern layer 20 and the performance of the transparent light diffraction pattern layer 30, the thickness may be required to be more than a certain level, and the total thickness of these layers is 4 to 30 μm. If
It is preferable to use a magnetic recording layer 2 having a magnetic field strength of 1.0 μWb / m or more. The upper limit is 2.
5 μWb / m). If it is less than the lower limit, it is not possible to obtain sufficient output at the time of issuance to read with a terminal in the market, and if it is more than the upper limit, the output reading waveform is saturated, and the peak of the waveform cannot be detected, This is because it becomes difficult to issue and read.

It is assumed that the concealing pattern layer 20 has a polka dot appearance. In this case, if the polka dot portion A and the portion other than the polka dot are formed using inks having different hues and all having high concealing properties, the concealing pattern layer 20 can be formed by one layer. When forming the concealed pattern layer 20 by the printing method, it is necessary to consider the printing registration deviation, and therefore, the portion A of the polka dot is slightly enlarged, or
It is good to make the missing portion corresponding to the polka dot portion of the portion B without polka dots smaller.

In the above system, since the design of the pattern is limited, a system in which a concealing layer 21 is formed as a lower layer and a picture pattern layer 22 is laminated thereon is preferable as a system having a higher degree of freedom in design. Using high-performance ink,
First, the concealing layer 21 is formed by uniform printing (= solid printing) or coating over the entire surface, and the picture pattern layer 22 is laminated thereon. As the ink having a high concealing property, an ink containing a pigment having a high concealing property such as titanium dioxide or aluminum powder and, if necessary, other coloring agents can be used. This ink having a high concealing property is common to the case where the concealing pattern layer 20 is formed by one layer.

In both cases where the concealing pattern layer 20 is formed by one layer and the concealing layer 21 is formed,
In terms of reliably realizing the concealment property, it is advantageous that the concealment pattern layer 20 and the concealment layer 21 have a large thickness, and it is advantageous to form a layer that needs to be formed by a screen printing method, a gravure printing method, or the like. It is. If the printing method is different, a different printing machine must be used.
1 may be directly laminated on the card base material 10, and the picture pattern layer may be formed separately. A pattern layer 22 on the concealing layer 21
When the pattern pattern layer 22 is formed by an offset printing method, a gravure printing method, a letterpress printing method or the like other than the silk screen printing method, the gradation of the formed pattern is rich, The thickness of the pattern layer 22 can be reduced. Since the picture pattern layer 22 is formed by a so-called ordinary printing method,
The lower layer can be seen through in low-density areas or in areas without ink. Therefore, the hue of the concealing layer 21 is set to white using titanium dioxide or a background color determined from the necessity in design.

When forming the concealing pattern layer 20, layers other than the concealing pattern layer 21 and the concealing layer 22 can be added as necessary. When these layers are formed directly on the card base material 10, if necessary, an anchor agent layer may be formed on the card base material 10 in order to improve the adhesiveness. Anchor agent layer is made of polyvinyl chloride resin,
It is preferable to use a polyvinyl acetate resin, a vinyl chloride-vinyl acetate copolymer resin, an acrylic resin, a polyester resin, a polyurethane resin, a polyamide resin, a modified rubber, or the like. A method in which the concealment pattern layer 20 is once formed on another temporary base material sheet and then transferred, and the influence of the solvent in the ink on the card base material is reduced,
Printing itself can be performed on a printing medium that is easy to print. In this case, when the concealing pattern layer 20 is composed of a single layer on the temporary base sheet, the concealing pattern layer 20 is formed alone and divided into the concealing pattern layer 20 and the concealing layer 21. In some cases, the concealing pattern layer 20 is formed first, and then the concealing layer 21 is formed.
To form The separation between the temporary base sheet and the concealing pattern layer 20 (or the concealing pattern layer 20) is ensured, and on the transfer sheet, the necessary strength is maintained until the transfer, so that the separation layer is provided between them. Should be formed. As the release layer, both a layer that adheres to the temporary base material sheet and peels off at the time of peeling and a layer that adheres to the concealing pattern layer 20 and peels off can be prepared. However, in the latter case, an anchor agent layer may be formed between the release layer and the concealment pattern layer 20 in order to secure the adhesiveness. The material of the anchor agent is the same as that described above. The concealing layer 21 may be directly formed on the card base material 10 in advance by silk screen printing or the like, and the pattern layer 22 may be formed by another printing method or by a transfer method. In this case, an anchor agent layer (= adhesive layer, the material is the same as that described above) is formed on the outermost surface of the transfer sheet in order to secure adhesion to the concealing layer 21 to be transferred. You may keep it. According to the latter method of transferring after silk screen printing,
Since the concealing layer 21 can be formed thickly and the picture pattern layer and the like can be formed on a printing medium that is easy to print, there is an advantage that the concealing effect and the precision of the picture pattern are both excellent.

In the magnetic card of the present invention, when the transparent light diffraction pattern layer 30 is a diffraction grating or a hologram among diffraction gratings, the minimum structure for visualizing the hologram is as follows: 31 is a laminated structure of a transparent light diffraction pattern layer 32, and preferably, a protective layer 33 is further laminated.

The transparent light diffraction pattern layer 32 has a transparent light diffraction pattern on one surface of a transparent synthetic resin, usually on the lower surface in order to prevent contamination or damage, or has an internal structure in the case of a volume hologram. Have a hologram diffraction grating. The former having irregularities is more suitable for mass production by a method such as hot pressing. As the light diffraction pattern, any of a plane hologram and a volume hologram can be used. Relief hologram, Limpman hologram, Fresnel hologram, Fraunhofer hologram, lensless Fourier transform hologram, laser reproduction hologram (image hologram, etc.), white light Reproduction holograms (rainbow holograms), color holograms, computer holograms, hologram displays, macplex holograms, holographic stereograms, holographic diffraction gratings, and mechanically formed diffraction gratings such as electron beam direct drawing.

The transparent light diffraction pattern layer 32 may be made of a thermoplastic resin or a curable resin capable of reproducing the unevenness of the light diffraction pattern by casting or embossing, or a cured portion in accordance with the light diffraction pattern information. A photosensitive resin composition capable of forming an uncured portion can be used. In particular,
For example, thermoplastic resins such as polyvinyl chloride, acrylic (polymethyl methacrylate), polystyrene, or polycarbonate, unsaturated polyester, melamine, epoxy, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, poly It is a thermosetting resin such as ether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, or triazine acrylate, and is used alone, thermoplastic resins, or a mixture of thermosetting resins, or A mixture of a thermoplastic resin and a thermosetting resin may be used. A resin having a radical polymerizable unsaturated group and having thermoformability, and an ionizing radiation curable resin composition to which a radical polymerizable unsaturated monomer is added can also be used. The thickness of the transparent light diffraction pattern layer 32 is 1 to
It is preferably about 2 μm.

Since the transparent light diffraction pattern layer 32 alone has no or very low visibility, an aluminum reflective film is usually provided. However, in the magnetic card of the present invention, the lower part of the light diffraction pattern layer is provided. In order to make the pattern layer visible, there is no problem with a mere reflection layer. In this sense, the transparent light diffraction pattern layer 32 is formed of a light refraction layer 31 made of a transparent thin film of a substance having a different refractive index of light to cause refraction and to provide visibility of a light diffraction pattern such as a hologram. . The light refraction layer 31 may be referred to as a reflective layer having transparency. Specifically, there are a thin film having a higher refractive index of light and a thin film having a lower refractive index of light than the transparent light diffraction pattern layer 32. Examples of the former include ZnS,
There are TiO ₂ , Al ₂ O ₃ , Sb ₂ S ₃ , SiO ₂ and the like, and examples of the latter include LiF, MgF ₂ , and AlF ₃ . A general light-reflective metal thin film such as aluminum also becomes transparent when its thickness is 200 ° or less, so that a transparent material made of a material having a different refractive index from the transparent light diffraction pattern layer 32 as described above is used. Since it has the same effect as a thin film, it can be used. Further, the transparent light diffraction pattern layer 32
A transparent synthetic resin having a different refractive index from light may be used.

As the synthetic resin constituting the transparent light diffraction pattern layer 32, it is desirable to select and use a hard resin having excellent abrasion resistance and contamination resistance. Since the first property is selected, the protection layer 33 is formed as a separate layer in the sense of further strengthening.
Are preferably laminated. As the resin forming the protective layer 33, a thermoplastic resin may be used, but a thermosetting resin composition using a thermosetting resin, or an ionizing radiation-curable resin composition cured by irradiation with ultraviolet rays or electron beams By using a curable compound such as above and heating after coating or by irradiating with ionizing radiation for cross-linking and curing, various physical and chemical properties can be further improved. The thickness of the protective layer 33 is preferably about 2 μm from the viewpoint of strengthening the protective function and reducing the thickness. The ionizing radiation-curable resin composition is obtained by appropriately mixing a prepolymer, an oligomer, and / or a monomer having a polymerizable unsaturated bond or an epoxy group in a molecule. Ionizing radiation refers to electromagnetic waves or charged particle beams having energy quanta that can polymerize or crosslink molecules, and usually use ultraviolet rays or electron beams.

Examples of prepolymers and oligomers in the ionizing radiation-curable resin composition include unsaturated polyesters such as condensates of unsaturated dicarboxylic acids and polyhydric alcohols, polyester methacrylates, polyether methacrylates, polyol methacrylates, melamines. Methacrylates such as methacrylate, polyester acrylate,
Examples include acrylates such as epoxy acrylate, urethane acrylate, polyether acrylate, polyol acrylate, and melamine acrylate, and cationic polymerization type epoxy compounds. To these prepolymers and oligomers, a polyfunctional monomer or a monofunctional monomer may be used by mixing one or more as necessary.
In order to provide the ionizing radiation-curable resin composition with normal coating suitability, the prepolymer or oligomer is added in an amount of 5% by weight.
As described above, the monomer and / or polythiol compound
It is preferably at most 5% by weight.

When flexibility is required when the ionizing radiation-curable resin composition is applied and cured, the amount of the monomer may be reduced, or an acrylate monomer having one or two functional groups may be used. . When abrasion resistance, heat resistance, and solvent resistance when applying and curing an ionizing radiation-curable resin composition are required, use ionizing radiation such as using an acrylate monomer having three or more functional groups. It is possible to design a curable resin composition. Here, the functional group is 1
Examples thereof include 2-hydroxyacrylate, 2-hexyl acrylate, and phenoxyethyl acrylate. Examples of those having two functional groups include ethylene glycol diacrylate and 1,6-hexanediol diacrylate. Examples of the compound having three or more functional groups include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

When curing after application of the ionizing radiation-curable resin composition is carried out by ultraviolet irradiation, a photopolymerization initiator or a photopolymerization accelerator is added. As the photopolymerization initiator, in the case of a resin system having a radically polymerizable unsaturated group, acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether or the like is used alone or as a mixture. In the case of a resin system having a cationically polymerizable functional group, an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metaceron compound, a benzoin sulfonic acid ester, or the like is used alone or as a mixture as a photopolymerization initiator. . The addition amount of the photopolymerization initiator,
0.1 parts by weight based on 100 parts by weight of the ionizing radiation-curable resin composition.
It is 1 to 10 parts by weight.

Similarly to the case where the concealing pattern layer 20 may be formed on the card substrate 10 using a transfer sheet, the transparent light diffraction pattern layer 30 is formed on a temporary substrate sheet so as to be peelable. Concealment pattern layer 2 previously formed on card substrate 10
0 may be transferred. When the concealing pattern layer is transferred, this is the second transfer. In a preferred embodiment, a protective layer 33, a transparent light diffraction pattern layer 32, and a light refraction layer 31 are sequentially laminated on a temporary base sheet, and further, in the sense of imparting adhesiveness to the concealing pattern layer 20, It is preferable to laminate an adhesive layer. When the light refraction layer 31 is made of a material having low adhesiveness, it is preferable to laminate an adhesive layer on the light refraction layer 31 via an anchor layer. The thickness of the adhesive layer and the anchor layer is preferably about 1 μm.

The magnetic card of the present invention may have various other means used in this field.
For example, printing layers such as necessary characters and descriptions, embossed characters,
Writable layer, optically recordable optical recording layer, IC or LSI
Etc. may be arbitrarily selected and formed into an appropriate one.

The method for forming each layer of the magnetic card of the present invention has been described each time. However, the preferred embodiments will be summarized as follows. First, the card base material 10, the magnetic tape serving as the magnetic recording layer 2, and at least the concealment pattern A transfer sheet A for transferring a layer 22 and an adhesive layer, preferably a release layer,
At least the light refraction layer 31 and the transparent light diffraction pattern layer 3
2. Preferably, a transfer sheet B for transferring the protective layer 33 is prepared. Next, a magnetic tape is temporarily placed on the card base material 10, and the transfer sheet A is further superimposed on the entire surface of the card base material 10 including the top on which the magnetic tape is temporarily placed, and heated and pressed by a hot press. And transfer of the concealment pattern layer 22 and the adhesive layer, preferably the release layer. Subsequently, the transfer sheet B is transferred to the concealing pattern layer 22.
And an adhesive layer, preferably further overlaid on the surface to which the release layer has been transferred, and again heated and pressed by a hot press to transfer the light refraction layer 31 and the transparent light diffraction pattern layer 32, preferably further the protection layer 33. Do. Before and after these transfer steps, if necessary, printing layers for necessary characters and explanations, embossed characters, writable layers, optically recordable optical recording layers, ICs
Alternatively, an LSI or the like is formed. Thereafter, if necessary, the product is cut to a specified size, and the product is formed.

[0029]

According to the first aspect of the present invention, since the two layers of the concealment pattern layer and the transparent light diffraction pattern layer are laminated on the magnetic recording layer, the transparent light diffraction pattern layer is laminated. Since a magnetic card having a high security function can be provided and at least two layers are laminated on the magnetic recording layer, it takes a long time before the magnetic recording layer starts to be worn.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the magnetic recording layer has a magnetic field intensity of 1.0 to 1.0.
Since at least 2.5 μWb / m was used, at least two layers of the concealment pattern layer and the transparent hologram layer were laminated, and even if the cap with the magnetic head became large, there was no problem in writing / reading to / from the magnetic recording layer. Absent.

According to the third aspect of the present invention, in addition to the effects of the first aspect of the present invention, the transparent light diffraction pattern layer has a protective layer made of a curable compound crosslinked and cured on the uppermost layer. The degree of protection is increased, the durability is increased, and the durability of the print is increased.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a basic configuration of a magnetic card.

FIG. 2 is a cross-sectional view illustrating a structural example of a card base material.

FIG. 3 is a cross-sectional view illustrating a structural example of a concealing pattern layer.

FIG. 4 is a cross-sectional view showing a structural example of a transparent hologram layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic card 2 Magnetic recording layer 10 Card base material 11 Oversheet 12 Core sheet 20 Concealment pattern layer 21 Concealment layer 22 Picture pattern layer 30 Transparent light diffraction pattern layer 31 Light refraction layer 32 Hologram layer 33 Protective layer

Continued on front page (72) Inventor Wakana Ishizaka 1-1-1 Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. (reference) 2C005 HA02 HA06 HB09 JA02 JA18 KA02 KA06 KA07 KA15 KA52 LA11 LA18 LA19

Claims (3)

[Claims] 1. A magnetic recording layer is formed on a part of a card base material, and a concealing pattern layer for covering at least the magnetic recording layer and concealing the magnetic recording layer, and a transparent light diffraction pattern layer are sequentially laminated. A magnetic card, characterized in that: 2. The concealing pattern layer has a thickness of 4 to 30 μm, and the magnetic recording layer has a magnetic field strength of 1.0 to 30 μm.
2. The magnetic card according to claim 1, wherein the magnetic card has a capacity of 2.5 [mu] Wb / m. 3. The magnetic card according to claim 1, further comprising a protective layer made of a curable compound crosslinked and cured on the transparent light diffraction pattern layer.