JP2001216632A - Magnetic information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic information recording medium which can prevent errors in the case of writing and reading the magnetic information due to static electricity and prevent problems of processing even when the magnetic information recording medium has an OVD(optical variable device) excellent in decorating property. SOLUTION: In the magnetic information recording medium 10 having a magnetic layer 12 in which magnetic information can be recorded, a hiding layer 13, and an OVD layer 14 on a recording substrate 11 having magnetic information, the hiding layer 13 consists of a thin film having no conductivity and a matted surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic information recording medium having magnetic information, such as a credit card or a cash card, which requires a forgery prevention effect. More specifically, an OV is provided to impart a forgery prevention effect to the information recording medium.
The present invention relates to a magnetic information recording medium having an OVD on which a D image is formed.

[0002]

2. Description of the Related Art A hologram, a diffraction grating, and a thin film having different optical characteristics, which can express a three-dimensional image or a special decoration image using light interference, cause a color change (color shift) depending on a viewing angle. OVD like multilayer thin film
(Optical Variable Device) is under development.

[0003] OVDs such as holograms and diffraction gratings are:
It is composed of a diffractive structure such as a fine concavo-convex pattern or a striped pattern having a different refractive index. This allows a unique image to be formed according to the angle viewed by light diffraction and interference (that is, the angle supporting the hologram). Or color change (color shift). On the other hand, a multilayer thin film has a structure in which ceramics and metal materials having different optical properties are stacked in multiple layers. This multi-layer thin film is a display technology that uses the interference of light obtained by the optical characteristics and film thickness of the constituent materials, and has reflection and transmission characteristics in a specific wavelength range. Occurs.

[0004] In the present specification, display technologies utilizing light interference such as holograms, diffraction gratings and multilayer thin films are collectively referred to as OVD.

[0005] These OVDs have an excellent decorative effect because they give unique impressions such as stereoscopic images and color shifts, and are used for general printed materials such as various packaging materials, picture books, catalogs and the like. Further, since this OVD requires advanced manufacturing technology, it is formed and used in credit cards, securities, certificates, etc. as effective counterfeit prevention means. Recently, some media have been formed on the entire surface of a medium by paying attention to the decorative effect of OVD.

On the other hand, cash cards and credit cards, which are information media having a magnetic information recording section, have been attempted to conceal the color of a black or brown-colored magnetic tape and to produce a card having no design restriction. As the method, a method of matching the color of the card itself with the color of the magnetic tape or a method of printing a pattern after applying a concealing ink such as white, black or silver from above. In the former case, there is a problem that the design is limited because the color is limited. In the latter method, the width of the design is widened, but the thickness of the concealment and printing is increased, so that there is a problem that the magnetic output is reduced. In particular, when the pattern printing layer and the above-described OVD are formed, there is a problem that the output is reduced due to an increase in the thickness of the OVD, and a reading error is likely to occur. If a specific example is given, a magnetic card such as a credit card having a magnetic stripe depends on the performance of the magnetic tape, but generally, the gap between the embedded magnetic tape and the surface of the card is limited to about 6 μm. There is a problem that must be.

[0007] Such a magnetic information recording medium provided with OVD having a high anti-counterfeiting effect has been difficult to read. According to JP-A-9-29443, the concealing layer is made of Al
There has been proposed a configuration in which the output is not reduced even if an optical diffraction image (hologram or diffraction grating) is formed by forming a thin film by forming a thin metal film such as Ni or Ni. However, this structure has a structure in which a metal, which is a conductor, and a plastic material, which is an insulator, are laminated on the information medium. Since the structure easily accumulates electric charges, it causes various problems due to static electricity at the time of processing. When writing or reading data, an error is likely to occur due to discharge of electric charge.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is intended to provide a magnetic information recording medium having an OVD which is excellent in decorativeness even when writing magnetic information by static electricity. It is an object of the present invention to provide a magnetic information recording medium capable of preventing a reading error and a trouble at the time of processing.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been made to achieve the above-mentioned object, and in a magnetic information medium having OVD, a magnetic information medium is provided by using a concealing layer having a mat-like surface. A magnetic medium provided in a card shape is visually concealed without interfering with reading and writing of the data, thereby increasing the degree of freedom in design.

That is, according to the first aspect of the present invention, in an information medium having at least a magnetic layer, a concealing layer, and an OVD layer capable of recording magnetic information on a recording medium substrate having magnetic information, A magnetic information recording medium characterized by being a thin film having no conductivity and having the surface of the thin film in a mat shape. By making the surface mat-like, the metallic luster can be suppressed as compared with the case where a metal thin film is simply provided, and light can be scattered to reduce the thickness of the thin film, thereby reducing writing and reading errors. Further, since a color tone close to white can be obtained, design selectivity can be expanded.

The invention according to claim 2 is the magnetic information recording medium according to claim 1, wherein the thin film constituting the concealing layer is a metal thin film having an island structure. Although each island has conductivity in this thin film, since the islands are separated from each other, the film itself has a property of not exhibiting conductivity. For this reason, it is difficult for electric charges to accumulate, and it is difficult for static electricity damage to occur.

The invention according to claim 3 is the magnetic information recording medium according to claim 1, wherein the thin film forming the concealing layer is made of a dielectric thin film such as a metal oxide. Since the dielectric thin film is an insulator, it is difficult for electric charges to accumulate, and it is difficult for static electricity damage to occur as in the case of the second aspect.

[0013] The invention according to claims 4, 5 and 6 provides:
2. The method according to claim 1, wherein, when the concealing layer is provided, the surface to be adhered is formed into a mat shape by an embossing method using heat and pressure, a mat shape by a sand blast method, and a mat shape by using an inorganic filler or a coloring pigment. It is a magnetic information recording medium.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of a magnetic information recording medium according to the present invention. FIG. 1A is a plan view, and FIG. 1B is a sectional view of the magnetic information recording medium of FIG. It is. Hereinafter, a detailed description will be given with reference to these drawings.

The magnetic information recording medium (10) shown in FIG.
Is a magnetic information recording medium substrate (1) having a magnetic layer (12).
The concealing layer (13) and the OVD layer (1)
4), a print layer (15), and a protective layer (16) are provided.
Only the pattern and character of "CARD" and the pattern of "BANK" which is OVD (14) can be confirmed. The magnetic layer is below the hiding layer and cannot be seen.

As the magnetic information recording medium substrate (11) having the magnetic layer (12), polyethylene terephthalate,
Magnetic layer capable of reading and writing magnetic information on a composite of synthetic resin such as polyethylene naphthalate, polyvinyl chloride, polyester, polycarbonate, polymethyl methacrylate, polystyrene, etc., or natural resin, paper, synthetic paper, etc., alone or in combination Is provided on the whole or a part of the magnetic information recording medium base material (11), and on the magnetic information recording medium base material (11), the concealment layer (13), the OVD layer (14), and the printing layer (1) are formed.
5) Since the protective layer (16) is laminated, it is required to have strength enough to withstand the processing, heat resistance and durability according to the method of use. Therefore, it is not limited to the above-mentioned materials, and is appropriately selected according to a processing method. There is no particular limitation on the thickness and shape of the medium depending on the form of the product, but it is necessary to conform to the standard if the medium is a standard such as a cash card or a credit card.

The concealing layer (13) is a layer for concealing the magnetic layer (12) and is a thin film having no conductivity. For example, a metal thin film having an island-like structure or a thin film made of a ceramic material can be used. Hereinafter, these will be described in more detail. The metal thin film having the island structure has a size of 0.
Particles of 02 to 1 μm are thin films formed into isolated islands at intervals of about 0.001 to 0.5 μm. Since the islands are separated from each other, the thin film as a whole does not exhibit conductivity. In addition, since the interval is very small, the film as a whole exhibits a characteristic of reflecting light, and the magnetic layer (12) can be concealed.

This thin film can be directly formed by a thin film forming method such as vacuum deposition, sputtering, ion plating or the like (Japanese Patent Publication No. 6-6783).
-Al alloy, Sn-Si alloy, Ti, Cr, Fe, N
Although i, Co, Si, Ge, etc. are mentioned, a metal with a low melting point or a noble metal is suitable for processing, and Sn, a Sn-Al alloy, and a Sn-Si alloy are preferable.

Another method of forming a thin film having an island structure is to use a material such as Al which is difficult to deposit with an island structure after forming a continuous thin film and then forming the island structure. It is also possible to manufacture by removing a thin film partially by etching. Any other method can be used as long as it is a known method capable of forming a thin film having an independent island structure, and is not limited.

On the other hand, the concealing layer using a dielectric material such as a metal oxide or a sulfide is made of, for example, TiO ₂ , Si ₂ O ₃ , Si.
O, SiO ₂ , Fe ₂ O ₃ , ZnS, MgO, Al ₂ O
₃ , a ceramic material of AlF ₃ . These materials vary depending on the color tone and the degree of light transmission.
It is provided by a known thin film forming method such as vacuum deposition, sputtering, or ion plating in the range of {10000}.

[0022] These materials do not exhibit conductivity, and are susceptible to static electricity.
Media that are unlikely to cause problems due to
High lightness and poor concealment. However, TiO_Two, Si
_TwoO _Three, ZnS and other materials have the same refractive index as plastic materials
Therefore, when laminated with plastic materials,
It has the property of reflecting light at boundaries. Use this property
Reflection of light by preliminarily roughening the surface on which the thin film is to be formed
By increasing the area and scattering the reflected light
And a white hiding layer can be obtained.

FIG. 1B is a cross-sectional view showing one embodiment of the magnetic information recording medium of the present invention, and is a cross-sectional view showing an example in which the concealing layer (13) is formed on a rough surface. Light is reflected and scattered on the surface of the concealing layer (13) to conceal the magnetic layer (12).

FIG. 2 shows a concealing layer transfer foil (20) for producing the magnetic information recording medium of the present invention shown in FIG. As shown in the drawing, a release layer (22) is applied to the support (21) of the concealment layer transfer foil with a plastic material which is easy to peel off, and is deposited with the above-mentioned ceramic material to form a concealment layer (matte surface). 23), after providing the adhesive layer (24), the magnetic information recording medium is transferred to a magnetic information recording medium base material to produce the magnetic information recording medium shown in FIG.

Further, by mixing particles such as an inorganic filler and a coloring pigment into the material of the release layer (22), the surface can be roughened and the hiding effect can be improved. The above is one example, and the method is not limited to this, as long as the method forms a thin film on the roughened surface. In addition, this method has the effect of improving the hiding power and whitening or coloring, and is also applicable to the above-mentioned metal thin film having an island structure. Further, it is possible to provide a concealing layer after making the magnetic layer less noticeable by performing concealing printing to enhance the concealing property or matching the color of the base material with the color of the magnetic layer.

The printing layer (15) should be above the OVD layer so as not to be obscured by the OVD layer (14). Therefore, in FIG. 1, the printing layer (15) is provided between the protective layer (16) and the OVD layer (14). However, a print layer may be provided between the OVD layer (14) and the concealing layer (13) as long as the OVD layer is transparent and the pattern, characters, etc. of the print layer can be read.

In the magnetic information recording medium (10) shown in FIG. 1, a portion indicated by printing "IDCARD" or "☆" is a printed layer, and information and background that can be visually confirmed for characters, symbols, characters, and other patterns. Is printed. This printing layer is provided by a known material and printing method.
Since 5) is on the magnetic layer (12), if it is formed thick, it causes a decrease in magnetic output. Note that the printing layer (15) is not an essential component, and may be provided if necessary depending on the application.

Next, the OVD layer (14) will be described in detail. The OVD layer (14) is a layer for forming an OVD image utilizing the above-described light interference, and is a layer for forming a display member which causes a color shift in which a color changes depending on the expression of a stereoscopic image and a viewing angle. Among them, OVDs such as holograms and diffraction gratings include a relief type for recording interference fringes of light on a plane as a fine uneven pattern and a volume type for recording interference fringes in a volume direction.

In general, a relief type master hologram having a fine concavo-convex pattern is produced by an optical photographing method, and a nickel press plate obtained by duplicating the concavo-convex pattern by electroplating is then copied. Mass replication is performed by a well-known method of heating and pressing this press plate on the hologram forming layer. This type of hologram is called a relief hologram.

Also, unlike a relief hologram,
There is a so-called volume hologram that records interference fringes in a volume direction using a recording material such as a photosensitive resin. In this type of hologram, a so-called Lippmann hologram is generally used, in which the refractive index of the photosensitive resin is changed in the volume direction to form a reflection hologram.

Further, unlike a hologram image capable of reproducing the three-dimensional image, a plurality of types of simple diffraction gratings are arranged in a minute area to form pixels, and a diffraction grating image such as a grating image or a pixelgram for expressing an image is also provided. In addition, mass replication is performed in the same way as a relief hologram, while the method is different from holograms and diffraction gratings.
Another example is a multilayer film system in which thin films of ceramics and metal materials having different optical characteristics are stacked and a color change (color shift) occurs depending on a viewing angle. Among these OVDs, in consideration of mass productivity and cost, a relief hologram (diffraction grating) or a multilayer thin film type is preferable. Hereinafter, a magnetic information recording medium using these will be described in detail.

FIGS. 3 and 4 are cross-sectional views illustrating an embodiment of the magnetic information recording medium of the present invention in the form of OVD. FIG. 3 shows a relief type hologram or diffraction grating using an OV.
This is an example where D is used, and on a magnetic information recording medium base material (31) having a magnetic layer (32), a matted concealing layer (33), OVD layer (34), printing layer (35), protection It has a configuration in which a layer (36) is provided. In this case, O
The VD layer (34) includes the OVD forming layer (34a) and the OVD
And an OVD effect layer (34b).
b) is made of a high refractive material thin film or a metal thin film that reflects light so as to obtain more diffraction efficiency.

FIG. 4 is a cross-sectional view of a multi-layer film structure which causes a color shift as OVD. The OVD layer (44) has thin films (44a, 44b, 4) having different optical characteristics.
4c). As described above, the configuration of the OVD layer differs depending on the OVD forming method, and a configuration in which a plurality of materials are stacked depending on the form is adopted. Therefore, the configuration is not limited to FIGS. 3 and 4, but is an embodiment.

As described above, the relief type hologram (diffraction grating) is a system in which a press plate having a fine concavo-convex pattern is heated and pressed against the OVD forming layer (34a) to copy the pattern. Therefore, the OVD formation layer (34)
a) is a material having good moldability by heat, hardly causing press unevenness, and providing a bright reproduced image, and is a thermoplastic resin such as a polycarbonate resin, a polystyrene resin, and a polyvinyl chloride resin, an unsaturated polyester resin, and a melamine resin. Or a thermosetting resin such as an epoxy resin or an ultraviolet or electron beam curable resin having a radically polymerizable unsaturated group, alone or in combination. In addition, any material other than the above can be used as long as it can form an OVD relief pattern.

When a relief type hologram (diffraction grating) is used, a reflection layer (OVD effect layer (34b) having a different refractive index from the polymer material used in the OVD formation layer (34a) is used to increase the diffraction efficiency. )) Is preferable. By providing the OVD effect layer (34b), diffraction efficiency is improved, and a clearer image and color change are brought about. As a material to be used, Ti having a different refractive index is used.
High refractive index materials such as O ₂ , Si ₂ O ₃ , SiO, Fe ₂ O ₃ , ZnS, etc., and island-shaped thin films such as Sn, Al, etc., which have higher reflection effects, may be used alone or by laminating these materials. Can be used. As described above, a material that does not exhibit conductivity is used for these layers, and is not limited thereto. These materials are formed by a known thin film forming technique such as a vacuum evaporation method or a sputtering method or an etching method.
It is formed in about Å.

In addition to the above, as a material constituting the OVD effect layer (34b), the refractive index thereof is a polymer material (refractive index n = 1.3) used in the OVD forming layer (34a).
-1.5), as long as the material does not exhibit conductivity, it can be used even if an inorganic filler is dispersed in an organic material, an organic-inorganic composite, or an organic material other than the above-mentioned inorganic material. It is. These materials are formed by a known coating method such as gravure coating, die coating, screen printing or the like, or a printing method to have a thickness of about 0.1 μm to 10 μm. Further, any material other than the above can be used as long as it has a reflective property.

On the other hand, the OVD layer (44) formed by the multilayer thin film method shown in FIG. 4 is composed of the multilayer thin films (44a, 44b, 44c) having different optical characteristics as described above, It is formed by laminating as a ceramic thin film or a composite thin film formed by attaching them. For example, when thin films having different refractive indices are stacked, a thin film having a high refractive index and a thin film having a low refractive index may be combined, or a specific combination may be alternately stacked. A desired multilayer thin film can be obtained by a combination thereof.

The multilayer thin film layer is made of a material such as ceramics or metal, and is formed by laminating approximately two or more high refractive index materials and a low refractive index material having a refractive index of about 1.5 with a predetermined thickness. is there. Examples of materials used below are given. First, as ceramics, Sb ₂ O ₃ (3.0
= Refractive index n: the same applies hereinafter), Fe ₂ O ₃ (2.7), Ti
O ₂ (2.6), CdS (2.6), CeO ₂ (2.
3), ZnS (2.3), PbCl ₂ (2.3), Cd
_{O (2.2), Sb 2 O} 3 (2.0), WO 3 (2.
0), SiO (2.0), Si ₂ O ₃ (2.5), In
₂ O ₃ (2.0), PbO (2.6), Ta ₂ O
₃ (2.4), ZnO (2.1), ZrO ₂ (2.
0), MgO (1.6), SiO ₂ (1.5), MgF
₂ (1.4), CeF ₃ (1.6), CaF ₂ (1.3
_{~1.4), AlF 3 (1.6)} , Al 2 O 3 (1.
6), GaO (1.7) and the like, and examples of the metal material include a thin film having an island structure of a simple metal or an alloy, for example, Al, Sn, Sn—Al and the like.

Further, low refractive index organic polymers such as polyethylene (1.51) and polypropylene (1.4)
9), polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49), polystyrene (1.60) and the like can be used. By selecting at least one of these high refractive index materials or metal thin films having an island-like structure having a transmittance of 30% to 60% and at least one of low refractive index materials and alternately stacking them at a predetermined thickness, a specific thickness is obtained. It indicates absorption or reflection of visible wavelength light. In the thin film made of metal, the optical characteristics such as the refractive index change depending on the state of the constituent materials and the forming conditions. Therefore, in the embodiments of the present invention, values under certain conditions are used.

The above materials are appropriately selected on the basis of optical characteristics such as refractive index, reflectance and transmittance, weather resistance, chemical resistance, interlayer adhesion, etc., and are laminated as thin films to form a multilayer thin film. As a forming method, a known method can be used, and the film thickness, the film forming speed, the number of layers, or the optical film thickness (= n · d,
An ordinary physical vapor deposition method such as a vacuum deposition method or a sputtering method or a chemical vapor deposition method such as a CVD method, which can control (n: refractive index, d: film thickness) and the like, can be used.

As a method for forming a low refractive index organic polymer, known printing methods such as gravure printing, offset printing and screen printing, and coating methods such as bar coating, gravure and roll coating are known. Etc. can be used. In the present invention, only ceramics / metals are disclosed, but any material having a refractive index and a reflectance similar or similar to ceramics / metals can be used.

To give a specific example of this multilayer thin film layer, the layer thickness is in the range of 50 to 20000 °, and the layer structure of the thin film is a thin film made of the above-mentioned high refractive index material or metal material, for example, ZnS , TiO ₂ , ZrO ₂ ,
In ₂ O ₃ , SnO, ITO, CeO ₂ , ZnO, Ta
Thin films made of the above materials having a low refractive index such as ₂ O ₃ , Al, Sn, etc., for example, MgF ₂ , SiO ₂ , CaF ₂ , M
gO, Al ₂ O _3, etc., which are alternately laminated, and the number of laminated layers is 2 or more, preferably 2 to 9 layers. Note that the optical characteristics of the multilayer film vary depending on the materials and combinations used, and the present invention is not limited to this.

The protective layer (16, 36, 46, 56) is made of O
It has a role to protect the VD layer and the printing layer from damage,
It is formed as needed. As the resin used, for example, acrylic resin, urethane resin, vinyl chloride resin-vinyl acetate copolymer resin, polyester resin, melamine resin, epoxy resin, polystyrene resin, conventionally known resin such as polyimide resin A thermoplastic resin, a thermosetting resin, an ultraviolet or electron beam curable resin is used alone or as a mixture.

Further, in order to prevent print marks during image formation with a thermal head or the like, a curing agent for crosslinking the resin, waxes such as polyethylene washes, carnauba wax, silicon wax, or calcium carbonate, zinc stearate, silica, etc. , Pigments such as alumina and talc, silicone
Fats and oils such as oils and fats can be added as long as the transparency is not impaired. The resin used for the release protection layer is applied by a known coating means such as a gravure printing method, a screen printing method or a nozzle coater method, and a printing means such as an offset printing method or a flexographic printing method.

A configuration in which the magnetic layer / matte concealing layer / OVD layer / printing layer / protective layer is laminated as the above-described magnetic information recording medium is merely an example, and it depends on the form of the product or the manufacturing method. It is possible to appropriately provide an adhesive layer or a printing layer on each layer. The order in which the layers are stacked is not limited to the order described above. For example, a configuration having a printing layer on the concealing layer or a configuration in which the OVD effect layer also functions as the concealing layer may be employed. On the other hand, it is also possible to add a configuration in which a latent image is provided with a fluorescent coloring ink, an infrared ink, a liquid crystal polymer or the like in order to improve forgery prevention.

When manufacturing such a magnetic information recording medium, the OVD transfer foil (50) shown in FIG. 5 may be used to transfer the magnetic information recording medium to a magnetic information recording medium substrate via an adhesive layer (52). The OVD transfer foil comprises a protective layer (56) having releasability, a printing layer (55), and an OVD transfer foil on an OVD transfer foil support (51).
It has a configuration in which a VD layer (54), a matte concealing layer (53), and an adhesive layer (52) are laminated. These materials and methods of preparation can utilize those described above. If this OVD transfer foil is transferred to a magnetic information recording medium substrate via an adhesive layer, the above-mentioned magnetic information recording medium can be easily manufactured.

The matting surface of the concealing layer may be provided on one or both of the front and back surfaces in consideration of the layer structure.

[0048]

EXAMPLES The present invention will be described in detail with reference to specific examples.

Embodiment 1 An embodiment of the magnetic information recording medium of the present invention shown in FIG. 3 will be described. First, the thickness of 760μ
magnetic information recording medium base material made of vinyl chloride (m)
A prototype was manufactured using a magnetic tape-containing card in which a 650 Oe magnetic tape was embedded as a magnetic layer (32) by heat and pressure. Sn on the surface of the magnetic information recording medium substrate (31)
After forming an OVD forming layer (34a) having the following composition by gravure method at 1 μm, and forming an OVD effect layer (34b) by TiO ₂ by vacuum evaporation at 500 °, the surface is made matte by depositing 500 ° in an island structure. A rainbow hologram pattern was formed by pressing a relief rainbow hologram stamper heated to 140 ° C. using a roll embossing method. Further, a pattern was printed at about 1 μm. Thereafter, an ultraviolet curable material having the following composition was applied as a protective layer (36) to a thickness of 2 μm, and cured by irradiating ultraviolet rays.

<OVD forming layer composition> Polyester 20 parts HMDI (hexamethylene diisocyanate) 5 parts MEK (methyl ethyl ketone) 50 parts Toluene 25 parts <Protective layer composition> Urethane acrylate 50 parts Acrylic monomer 45 parts Photopolymerization initiator 5 parts

In the magnetic card thus obtained, no magnetic layer was observed in appearance, and the magnetic card could be concealed by only 500 ° Sn vapor deposition. Also, a good magnetic output was obtained because the distance between the magnetic tape and the card surface was about 5.0 μm. In addition, since there is no accumulation of electric charge in the stacked state and no sudden discharge of electricity,
Work was easy, and no error occurred even when writing and reading magnetic information several tens of times.

Embodiment 2 An embodiment of the magnetic information recording medium of the present invention shown in FIG. 4 will be described. A magnetic card of Example 2 was obtained in the same manner as in Example except that the OVD layer (44) was a multilayer thin film.

As this multilayer foil thin film, ZnS-950
Å, SiO ₂ -5800Å, and ZnS-950 順 に were sequentially formed to form an OVD layer (44).

In the magnetic card thus obtained, no magnetic layer was observed in appearance, and the magnetic card could be concealed by only 500 ° Sn vapor deposition. Also, a good magnetic output was obtained because the distance between the magnetic tape and the card surface was about 5.0 μm. In addition, since there is no accumulation of electric charge in the stacked state and no sudden discharge of electricity,
Work was easy, and no error occurred even when writing and reading magnetic information several tens of times. On the other hand, in this embodiment, since a multi-layer thin-film OVD layer was formed, a highly decorative card whose color changed depending on the viewing angle was obtained.

[0055]

As described above, in the magnetic information recording medium of the present invention, the OVD is formed by concealing the magnetic layer with the matted thin film having no conductivity. It is possible to provide a medium that can provide a sufficient magnetic output and that does not cause a problem during handling or an error when writing or reading magnetic information. That is, the magnetic layer is not apparent in appearance, can be concealed, does not accumulate charges in a stacked state, and does not rapidly discharge static electricity. This is a magnetic information recording medium free from errors.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a magnetic information recording medium of the present invention,
(A) is a plan view, and (B) is a cross-sectional view taken along a line XX.

FIG. 2 is a cross-sectional view of the configuration of a concealing layer transfer foil for producing a matted concealing layer shown in FIG. 1 (B).

FIG. 3 is an embodiment of the magnetic information recording medium of the present invention,
FIG. 4 is a cross-sectional view of a configuration when a relief type OVD is used.

FIG. 4 is an embodiment of the magnetic information recording medium of the present invention,
FIG. 3 is a cross-sectional view of a configuration when a multilayer thin film type OVD is used.

FIG. 5 is a configuration sectional view of an OVD transfer foil.

FIG. 6 is a conceptual diagram illustrating an island structure of a concealing layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Magnetic information recording medium 11 ... Magnetic information recording medium base material 12 ... Magnetic layer 13 ... Concealment layer 14 ... OVD layer 15 ... Printing layer 16 ... Protective layer 20 ... Concealment layer transfer foil 21 ... Concealment layer transfer foil support 22 ... Release layer 23 ... Hiding layer 24 ... Adhesive layer 30 ... Magnetic information recording medium 31 ... Magnetic information recording medium base material 32 ... Magnetic layer 33 ... Hiding layer 34 ... OVD layer 34a ... OVD forming layer 34b ... OVD effect layer 35 ... Printing layer 36 Protective layer 40 Magnetic information recording medium 41 Magnetic information recording medium base 42 Magnetic layer 43 Concealing layer 44 OVD layer 44a, 44b, 44c Thin film layer 45 Printing layer 46 Protective layer 50 OVD transfer Foil 51 ... OVD transfer foil support 52 ... Adhesive layer 53 ... Hiding layer 54 ... OVD layer 55 ... Printing layer 56 ... Exfoliation protection layer 60 ... Hiding layer 61 ... Metal thin film (island)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C005 HA10 HA26 HB09 JA02 JB08 JB09 JB12 JB14 KA08 KA09 KA10 KA15 KA37 KA40 LA11 LA30 LB09 5D006 AA02 AA05 AA06 DA01 5D112 AA09 BD03 GA09

Claims (6)

[Claims] 1. An information medium having at least a magnetic layer capable of recording magnetic information, a concealing layer, and an OVD layer on a recording substrate having magnetic information, wherein the concealing layer is a thin film having no conductivity. A magnetic information recording medium, characterized in that the surface of the magnetic information recording medium has a mat shape. 2. The magnetic information recording medium according to claim 1, wherein the thin film forming the concealing layer is a metal thin film having an island structure. 3. The magnetic information recording medium according to claim 1, wherein the thin film forming the concealing layer comprises a dielectric thin film such as a metal oxide. 4. The magnetic information recording medium according to claim 1, wherein when the concealing layer is provided, a surface to be adhered is formed in a mat shape by an embossing method using heat and pressure. 5. The magnetic information recording medium according to claim 1, wherein when the concealing layer is provided, a surface to be adhered is formed in a mat shape by a sandblast method. 6. The magnetic information recording medium according to claim 1, wherein when the concealing layer is provided, the surface to be adhered is made mat-like with an inorganic filler or a coloring pigment.