JP2002042319A - Magnetic recording medium and transfer sheet for covering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording medium, where output reduction and the like due to an increase of spacing loss hardly generated, even if the thickness of a covering layer, e.g. a masking layer, decorative layer or the like is increased, and writing and reading of information are made possible. SOLUTION: A magnetic recording layer 3 having 580-720 oersted coercive force and squareness ratio of >=0.85 is laminated, on a base material 2 by using Ba-ferrite having a planar ratio of >=1.5 as a magnetic material; and preferably, the covering layer consisting of the masking layer 7, multicolored pattern layers 5a-5c, a light diffractive structure 8, a protective layer 9 and the like and having 8-25 μm total thickness is laminated on the upper surface of the magnetic recording layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium, and it is possible to prevent the presence of a magnetic recording layer provided on or in a base material from being apparent, and to provide an excellent design feeling. The present invention relates to a magnetic recording medium that has a decorative layer to be applied and that can record and read information using a magnetic recording layer without any trouble. Further, the present invention, when manufacturing such a magnetic recording medium, the magnetic recording layer is concealed above the magnetic recording layer with respect to the base having the magnetic recording layer on or in the base. The present invention also relates to a hiding layer and a transfer sheet for coating capable of transferring a layer for decoration or other purposes.

[0002]

2. Description of the Related Art Magnetic recording media having a magnetic recording layer formed by laminating a layer containing a magnetic material on a base material are used in various applications. Specifically, prepaid cards, commuter passes, boarding tickets, entrance tickets, voting tickets such as bicycle races and horse races, gift certificates,
Cards and securities such as stock certificates, certificates, bankbooks or banknotes, or magnetic tags, cards such as bankcards, credit cards, ID cards (for example, ID cards), or membership cards, magnetic tapes, magnetic transfer tapes, or magnetic cards There are labels.

[0003] In these magnetic recording media, writing is performed on the magnetic recording layer using a dedicated writer and reader, and care is taken to prevent the recorded information from being easily read. In recent years, a magnetic recording layer has been coated with a highly concealable coating film to make it hard to see (Japanese Patent Publication No. 5-76701).

However, in practice, there are restrictions when coating with a highly opaque coating film. In particular, in the case of a credit card, it is used overseas, and also in a bank card,
It is used in a wide range, such as used at main branches and other banks.
For this reason, standards are strictly defined in order to ensure compatibility. At present, a magnetic material made of Fe ₂ O ₃ and having a coercive force of 650 Oe is generally used.

However, in the magnetic card having a coercive force of 650 Oersteds, when a concealing layer is formed on the magnetic recording layer, if the concealing layer becomes thicker, the output is reduced due to an increase in spacing loss. For this reason, in order to reliably perform writing and reading using the magnetic recording layer, it is necessary to reduce the thickness of the concealing layer to less than 8 μm. Or, the concealing layer can not be formed in a multicolor pattern,
Therefore, the appearance on the magnetic recording layer tends to be simple.

[0006]

In the present invention, a light diffractive structure is applied to the surface in addition to the concealing layer, and more preferably, a pattern layer is applied together with the light diffractive structure. It is an object of the present invention to provide a magnetic recording medium which is less likely to cause a decrease in output due to an increase in pacing loss and which has an excellent design feeling. Another object of the present invention is to provide a transfer sheet capable of giving an excellent design feeling when manufacturing a magnetic recording medium.

[0007]

The object of the present invention is to provide a magnetic recording medium using Ba-ferrite having a plate ratio of 1.5 or more as a magnetic material, a coercive force of 580 to 720 Oersted, and a squareness ratio of 0.85 or more. This problem was solved by using a magnetic recording layer that is a opaque layer and a light diffractive structure, or a concealing layer, a pattern layer, and a non-diffractive structure in order above the magnetic recording layer provided on the base material. . Further, the above-mentioned problem is to provide a transfer sheet for obtaining a magnetic recording medium, a concealing layer and a light diffraction structure, a pattern layer and a light diffraction structure, or
The problem was solved by providing a structure having a concealing layer, a pattern layer, and a light diffraction structure as a transfer layer.

[0008] The first invention is directed to Ba having a plate-like ratio of 1.5 or more.
Ferrite is dispersed in a binder resin as a magnetic material, a coercive force is 580 to 720 Oersted, and a squareness ratio is 0.85 or more. A concealing layer for concealing the recording layer is laminated, and the light-reflective layer and the light diffraction structure layer are sequentially laminated from the lower layer side above the base material including the concealing layer. The present invention relates to a magnetic recording medium characterized by the following. According to a second aspect of the present invention, in the first aspect, a pattern layer is laminated on a part of the upper portion of the substrate including the concealing layer, and the pattern layer is also laminated on the concealing layer or the pattern layer. The present invention relates to a magnetic recording medium characterized in that a light reflective layer and a light diffraction structure layer are sequentially laminated from above on a substrate. Third
The present invention relates to the magnetic recording medium according to the first or second invention, wherein a protective layer is laminated on the light diffraction structure. The fourth invention is the third invention
The present invention relates to a magnetic recording medium, wherein a peelable layer is laminated on the protective layer. The fifth invention relates to a transfer sheet for coating, wherein a light diffractive structure layer, a light reflective layer, and a concealing layer are sequentially laminated on a release surface of a release support sheet. . The sixth invention relates to a transfer sheet for coating, wherein a light diffractive structure layer, a light reflective layer, and a pattern layer are sequentially laminated on a release surface of a release support sheet. . A seventh invention relates to the transfer sheet for covering according to the fifth invention, wherein a pattern layer is laminated between the light reflective layer and the concealing layer. An eighth invention is characterized in that in any one of the fifth to seventh inventions, a protective layer is laminated between the releasable surface of the releasable support sheet and the light diffraction structure layer. And a transfer sheet for coating. The ninth invention is directed to the fifth to fifth aspects.
In any one of the seventh inventions, the present invention relates to a transfer sheet for coating, wherein a release layer is laminated between the release surface of the release support sheet and the light diffraction structure layer. It is. In a tenth aspect, based on the eighth aspect,
The present invention relates to a transfer sheet for coating, wherein a release layer is laminated between the release surface of the release support sheet and the protective layer. The eleventh invention is the fifth invention.
In any one of the tenth to tenth aspects, the present invention relates to a transfer sheet for coating, wherein an adhesive layer is laminated on the concealing layer.

[0009]

FIG. 1 shows a magnetic recording medium 1 according to the present invention.
FIG. 16 is a plan view showing a credit card, which is an example of an application example of FIG. In the example shown in FIG. 1, the magnetic recording medium 1
A magnetic recording layer 3 is laminated on the card base material 2, and a non-contact type IC module 4 is embedded in a different position from the magnetic recording layer 3. One surface of them is covered with a concealing layer 7, and The transparent hologram 8 is laminated on one surface. Further, the magnetic recording medium 1 is provided with printing 5 (or a pattern layer) for giving a card name or an arbitrary design, and is provided with embossed characters 6 by embossing.

The magnetic recording layer 3 in the magnetic recording medium 1 of FIG. 1 is made of Ba-ferrite having a plate ratio of 1.5 or more dispersed in a binder resin as a magnetic material. Coercive force is 580-720 Oersted,
It is characterized in that the squareness ratio is 0.85 or more. The magnetic recording medium 1 described with reference to FIG. 1 is an example of a card, and the information recording means applied to the base material 2 of the card can be arbitrarily selected from various known ones. .

FIG. 2 and FIG. 3 are cross-sectional views for explaining a typical embodiment of the magnetic recording medium 1 of the present invention. For example, it represents a laminated structure when cut along the line AA.

In the magnetic recording medium 1 shown in FIG. 2, a magnetic recording layer 3 is embedded in a substrate 2 such that the upper surface of the magnetic recording layer 3 and the upper surface of the substrate 2 form a continuous plane. The concealing layer 7, the light reflective layer 8b, and the light diffraction structure layer 8a are sequentially laminated on the substrate 2 having the magnetic recording layer 3 as described above.

The magnetic recording medium 1 shown in FIG. 3 has a concealing layer 7, a pattern layer 5c of each color on a base material 2 having a magnetic recording layer 3 through an adhesive layer 10 as in FIG. 5b,
The pattern layer 5, the light reflective layer 8b, and the light diffraction structure layer 8a are sequentially laminated, and the protective layer 9 is further laminated thereon.

In the example shown in FIGS. 2 and 3, the magnetic recording layer 3 and the substrate 2 are embedded and laminated so that the upper surface of the magnetic recording layer 3 and the upper surface of the substrate 2 form a continuous plane. However, the magnetic recording layer 3 may not necessarily be laminated in this way, and the magnetic recording layer 3 may protrude slightly from the upper surface of the base material 2 or may be more embedded in the base material. Good.

FIG. 4 shows the relationship between the substrate 2 and the magnetic recording layer 3. In both FIGS. 4 (a) and 4 (b), the substrate 2 has two upper and lower core sheets. 2b and 2
b 'comprises a four-layered laminate in which one oversheet 2a and one oversheet 2a' are disposed on the front side and the back side, respectively. A general card has a base material of such a laminate. are doing.

In the case of such a conventional four-sheet construction, the two oversheets 2a and 2a 'are made of the same material and thickness, and the two core sheets 2b and 2b' are made of the same material. And the thickness is usually the same. In the case of such a conventional four-sheet configuration, generally, the two core sheets 2b and 2b ′ are opaque, for example, white sheets, and the two oversheets 2a, And, 2a 'is often a colorless and transparent sheet.

In FIG. 4A, two magnetic recording layers 3 and 3 'are embedded so as to form a continuous plane with the upper surface of the upper and lower oversheets 2a and the lower surface of 2a', respectively. Further, in FIG. 4B, two magnetic recording layers 3 and 3 ′ are respectively formed by upper and lower core sheets 2b.
The upper surface and the lower surface of 2b 'are embedded so as to form a continuous plane, and such a structure can be adopted. However, the thickness of the oversheet may be determined in consideration of the performance of the magnetic recording layer 3.

In FIG. 4A and FIG. 4B, the two magnetic recording layers 3 and 3 'are both stacked at symmetric positions in the thickness direction. The layers may be stacked at positions symmetrical to the thickness direction, such as a layer on the outer surface of the oversheet and the other magnetic recording layer on the outer surface of the core sheet. The number of the magnetic recording layers 3 is not limited to the example illustrated above, and may be three or more.

In each of the above figures, the magnetic recording layer 3 is drawn assuming a magnetic stripe, but the planar shape of the magnetic recording layer 3 is not limited to a stripe shape, but may be another shape. In the above-described drawings, the position for providing is set slightly inside along one side in the longitudinal direction of the base material 2 of the card, but may be another position. The magnetic recording layer may be provided on the entire surface of the base material to increase the recording capacity. When two or more magnetic recording layers are provided, a combination of the entire surface magnetic recording layer and a stripe-shaped magnetic recording layer may be used.

When the magnetic recording medium 1 has two or more magnetic recording layers, one of the magnetic recording layers is made of Ba-ferrite having a plate ratio of 1.5 or more as a magnetic material. The magnetic recording layer has a coercive force of 580 to 720 Oersted and a squareness ratio of 0.85 or more. , May have other magnetic properties.

In the present invention, as the substrate 2, paper, plastic sheet, metal foil or metal plate, etc. can be used alone or in combination. Depending on the application, select the required rigidity, flexibility, processing adhesiveness, printing suitability, if necessary, considering embossing suitability, etc.
use. In the case of a card, a sheet made of vinyl chloride resin is often used at present because of its suitability for processing.
Due to the recent review of plastic materials, it is preferable to use a sheet of a polyolefin resin or an embossable non-crystalline polyester resin which does not cause a problem in incineration at the time of disposal. When a plastic sheet is used, an opaque color sheet such as white or a transparent sheet may be used.

Examples of the non-crystalline polyethylene terephthalate resin include those in which the dicarboxylic acid component is terephthalic acid and the diol component is ethylene glycol and 1,4-cyclohexanedimethanol. As the diol component, the former is about 70% by mass and the latter is about 30% by mass.

In addition, as a plastic sheet,
Polyamide resin (nylon resin), cellulose diacetate resin, cellulose triacetate resin, polystyrene resin, polyethylene resin, polypropylene resin, polyester resin (polyethylene terephthalate resin, etc.),
A sheet of a polyimide resin, a polycarbonate resin, a polyolefin resin, or another resin can also be used.

When heat resistance is required and embossing suitability is required for applications such as cards, it is preferable to use the above-mentioned non-crystalline polyester resin sheet, and higher heat resistance is required. In such a case, a sheet of a blended resin of an amorphous polyester resin and a polycarbonate resin may be used.

The magnetic recording layer 3 is made of B having a plate ratio of 1.5 or more.
a-ferrite is dispersed in a binder resin as a magnetic material, and the coercive force of the magnetic recording layer 3 is 58
It is desirable that the squareness ratio be 0 to 720 Oersted and 0.85 or more.

In the above description, a magnetic material having a plate ratio of 1.5 or more has a smaller rate of change in coercive force with respect to a change in temperature and the like than a magnetic material having a plate ratio of less than 1.5. And the squareness ratio also tends to increase.
The above range of coercivity is currently widely used, Fe
_A material corresponding to a magnetic recording layer having a coercive force of 650 Oersted using ₂ O ₃ as a magnetic material and having a range of ± 70 Oersted (corresponding to about ± 10%) around 650 Oersted, A writing / reading device made on the assumption of a magnetic recording layer of 650 Oersteds does not hinder writing or reading. Further, in the above, when the squareness ratio is 0.85 or more, not only because a higher output can be obtained than when the squareness ratio is less than 0.85, but also the output attenuation due to an increase in spacing loss on the magnetic recording layer. Is also small, which is preferable.

The above-mentioned magnetic substance is composed of a binder resin, a solvent,
The ink composition or coating composition for forming a magnetic recording layer obtained by mixing and dispersing with a diluent or the like is coated on a substrate by a known coating method, for example, a gravure coating method, a roll coating method, or a knife edge method. The magnetic recording layer 3 can be applied directly on the sheet 2 or on the sheet constituting the substrate 2 and cured by drying or the like.

Alternatively, it is applied to a plastic film or the like different from the base material, and the formed product is applied on the base material 2 by means of an adhesive or the like, or is applied to a releasable plastic film. The formed material may be transferred to the base material 2 or a sheet constituting the base material 2 via an adhesive or the like to form the magnetic recording layer 3. Alternatively, the magnetic recording layer can be formed by forming the magnetic material into a thin film by a vacuum evaporation method, sputtering, plating, or the like.

As the binder resin used in the ink composition or the coating composition for forming the magnetic recording layer, polyvinyl butyral resin, vinyl chloride / vinyl acetate copolymer resin, polyurethane resin, polyester resin, cellulose resin, acrylic resin, A styrene / maleic acid copolymer resin or the like can be used, and a rubber-based resin such as a nitrile rubber or a urethane elastomer is added as necessary. In consideration of heat resistance, a resin having a high glass transition point such as polyamide, polyamide resin, polyimide resin, or polyethersulfone may be used, or the glass transition point is increased by a curing reaction with an isocyanate compound or the like. A system can also be used.

To the ink composition or coating composition for forming the magnetic recording layer, a surfactant, a silane coupling agent, a plasticizer, a wax, a silicone oil, carbon, or the like may be added, if necessary. You may have.

When the magnetic recording layer 3 is formed by a coating method, the thickness is preferably about 1 to 100 μm, more preferably about 5 to 20 μm. Also, vacuum deposition method,
When formed by sputtering, plating, or the like, preferably 10 nm to 1 μm, more preferably 50 nm
m to 200 nm. In order to increase the output, it is preferable to increase the thickness of the magnetic recording layer 3. In particular, when the concealing layer 7 is laminated on the magnetic recording layer 3 or other layers are laminated, the thickness of the magnetic recording layer 3 may be increased.

Since the concealing layer 7 is laminated for the purpose of concealing the existence of the magnetic recording layer, it may be laminated only on the magnetic recording layer 3 at a minimum, whereby the magnetic recording layer 3 is concealed. It is. However, since it is known that at least one magnetic recording layer 3 exists in the magnetic recording medium such as the card 1, the position of the magnetic recording layer 3 may be clarified instead. In general, it is preferable to have an area that can cover not only the magnetic recording layer 3 but also the periphery of the magnetic recording layer 3. It is more preferable to cover the entire upper surface, because the position of the magnetic recording layer 3 becomes more unclear.

The concealing layer 7 may be provided in the form of a pattern. Even if the magnetic recording layer 3 is physically visible from the gap between the concealing layers 7, the gap between the magnetic recording layer 3 and the surroundings is located in the gap. , The presence of the magnetic recording layer 3 is not clear.
As described above, even if a part of the magnetic recording layer 3 is visible, but the boundary between the magnetic recording layer 3 and the surroundings is not clear, it is also considered to be in the category of “hiding at least the magnetic recording layer”.

The concealing layer 7 is formed by printing or applying a concealing layer-forming composition containing a pigment having a high concealing property, at least above the magnetic recording layer 3, preferably at least above the magnetic recording layer 3. Is formed on the entire surface of the substrate 2 of the card 1 including the upper part of the card 1. As the composition for forming the concealing layer, a paint composition exhibiting a metal color such as gold or silver or a paint composition containing a pigment having a high concealing property such as titanium dioxide may be used. Alternatively, the formation of the concealing layer 7 may be performed using a transfer sheet having the concealing layer 7 alone or together with other layers as a transfer layer. The concealing layer 7 preferably has a thickness of about 3 to 5 μm, although it depends on the material constituting the concealing layer 7.

The concealing layer 7 is formed by a binder resin, fine particles of a metal or alloy exhibiting a metallic color such as gold or silver, a concealing agent such as titanium dioxide if necessary, a coloring agent such as a dye or pigment, and other components. Is mixed with a solvent and a diluent, and the ink composition or coating composition for forming a concealing layer obtained by dissolving or dispersing is mixed with a known coating method, for example, a gravure coating method or a roll coating method. It can be performed by applying the solution on the magnetic recording layer 3 on the base material 2 by a knife edge method or the like and curing it by drying or the like. Alternatively, by applying an adhesive applied to an object to be coated, which is different from the substrate, and the like,
It is transferred onto the base material 2 having the magnetic recording layer 3 by pasting it on the base material 2 having the magnetic recording layer 3 or applying it to a releasable coated object with an adhesive or the like. You may.

Examples of the binder resin used in the ink composition or the coating composition for forming the concealing layer include cellulose derivatives such as ethyl cellulose, nitrocellulose, ethyl hydroxycellulose, cellulose acetate propionate or cellulose acetate, polystyrene and poly-α. Styrene resin such as methyl styrene, or styrene copolymer resin, polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate, or acrylic resin such as polybutyl acrylate or methacrylic resin alone or copolymer resin, Rosin, rosin-modified maleic resin, rosin-modified phenol resin, or rosin ester resin such as polymerized rosin, polyvinyl acetate resin, coumarone resin, vinyl toluene resin, polyvinyl chloride resin, vinyl chloride / Vinyl acetate copolymer, polyester resins, polyurethane resins or polyvinyl butyral resin, can be used.

The ink composition or the coating composition for forming the concealing layer may optionally contain fine powders such as titanium dioxide, alumina and microsilica having a magnetic head cleaning effect. As additives,
In addition, plasticizers, stabilizers, waxes, greases, desiccants, drying aids, curing agents, thickeners, dispersants, and the like can be used as necessary.

The pattern layer 5 usually has a pattern such as a character or a pattern formed by a printing method. When the magnetic recording layer 3 is laminated on a part of the substrate, it is laminated on the substrate. In some cases, they may not be formed, but they may be stacked. The pattern layer 5 may be composed of a single layer, but is formed in two layers or in three primary colors of yellow, red, and blue as described with reference numerals 5a, 5b, and 5c in FIG. It may be composed of three layers, or may be composed of more layers. Specifically, in addition to printing, printing of ink jet, or electrophotography, or a method similar to printing once to make a single pattern layer,
By applying the method a plurality of times, a multilayer pattern layer 5 can be obtained. As the ink composition for forming the pattern layer used when forming the pattern layer 5 by printing, the binder resin, the dye or the pigment exemplified as the ink composition for forming the concealing layer or the coating composition described above is used. Prepared by kneading with a coloring agent and a solvent or a diluent.

As a hologram which is a typical example of the light diffraction structure 8, both a plane hologram and a volume hologram can be used. Reproduction holograms (such as image holograms), white light reproduction holograms (such as rainbow holograms), color holograms, computer holograms, hologram displays, multiplex holograms, holographic stereograms, holographic diffraction gratings, and the like.

The light diffraction structure 8 is usually composed of the light diffraction structure layer 8
a is the upper side (= observation side), and the light reflective layer 8
b is laminated.

As materials for forming the light diffraction structure layer 8a, polyvinyl chloride, acrylic resin (eg, PMMA),
Thermoplastic resins such as polystyrene and polycarbonate,
Unsaturated polyester, melamine, epoxy, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate,
Thermosetting resins such as melamine (meth) acrylate and triazine acrylate can be used alone or in combination with the thermoplastic resin and the thermosetting resin. Further, radical polymerizable unsaturated groups can be used. It is possible to use a thermoformable substance having the composition or a substance obtained by adding a radical polymerizable unsaturated monomer to the composition to make the composition curable with ionizing radiation. In addition, silver salts, gelatin dichromate, thermoplastics, diazo photosensitive materials, photoresists,
Photosensitive materials such as ferroelectrics, photochromic materials, thermochromic materials, and chalcogen glass can also be used.

The light diffraction structure layer 8a can be formed by a conventionally known method using the above-mentioned materials. For example, when recording the interference fringes of a diffraction grating or a hologram as a relief of surface irregularities, an original plate on which the diffraction gratings or the interference fringes are recorded in the form of irregularities is used as a press mold, and the release layer On the protective layer of the laminated sheet in which the protective layer is sequentially laminated, the coating solution of the resin for the light diffraction structure layer is applied by means such as a gravure coating method, a roll coating method, and a bar coating method to form a coating film. Then, the original is placed on top of it, and the two are heated and pressed by an appropriate means such as a heating roll, so that the concavo-convex pattern of the original can be duplicated. When a photopolymer is used, a photopolymer can be coated on the protective layer of the laminated sheet in the same manner, and then the original can be overlapped and irradiated with a laser beam to perform replication.

As described above, the method of recording the interference fringes of the diffraction grating or the hologram on the surface of the light diffraction structure layer as the relief of the surface unevenness is particularly preferable because it has mass productivity and can reduce the cost. The thickness of such a light diffraction structure layer is 0.1
The range is preferably from 6 to 6 µm, more preferably from 0.1 to 4 µm.

When interference fringes of a diffraction grating or a hologram are recorded on the surface of the light diffraction structure layer 8a as an uneven relief as described above, the light reflective layer 8b is placed on the relief surface in order to increase the diffraction efficiency. Preferably, it is formed. If a light-reflecting metal thin film of aluminum or the like is formed on the relief surface as the light-reflective layer 8b, a reflection type light diffraction structure, typically a hologram, can be obtained, and if a transparent thin film is formed on the relief surface, A transparent light diffraction structure, typically a hologram, is obtained. Whether the reflective type or the transparent type is used can be appropriately selected depending on the purpose. When the pattern layer 5 is provided below the light diffraction structure 8, the upper surface of the magnetic recording medium 1 is used. In order to ensure the visibility of the pattern layer 5 from the side, it is desirable to use a transparent type.

When a non-transparent metal thin film is used as the light-reflective layer, the light-reflective layer must be directed to the side opposite to the observation side of the light diffraction structure layer. In the case of a reflective layer, the light reflective layer may be directed to any of them.
In short, the laminated structure in which the light-reflective layer is laminated on the relief surface of the light-diffractive structure layer may be arranged in such a direction that the light-diffractive structure (typically, a hologram) can be seen from the observation side. When printing is performed on the lower layer of the light diffraction structure layer, it is necessary to have transparency in the sense of securing these visibility,
The light diffraction structure is preferably a transparent light diffraction structure using a transparent thin film.

When forming the light-reflective layer with a metal thin film,
Cr, Fe, Co, Ni, Cu, Ag, Au, Ge, A
1, Mg, Sb, Pb, Cd, Bi, Sn, Se, I
A metal such as n, Ga, or Rb, an oxide thereof, or a nitride thereof is formed alone or in combination. Among these, Al, Cr, Ni,
Ag or Au is particularly preferred. When the light reflective layer is formed of a metal thin film, a thin film forming method such as a vacuum evaporation method, a sputtering method, and an ion plating method is used.

As a material of the light reflecting layer, a continuous thin film of a substance having a different refractive index from that of the light diffraction structure layer may be used. The thickness of the continuous thin film may be any as long as it is a transparent region of the material forming the thin film, but is usually preferably 100 to 1000 °. As a method of forming a continuous thin film on the relief surface, a vacuum deposition method,
A thin film forming method such as a sputtering method or an ion plating method may be used. The continuous thin film may have a refractive index larger or smaller than that of the light diffraction structure layer, but preferably has a refractive index difference of 0.3 or more, a difference of 0.5 or more, and more preferably 1.0 or more. Is more preferable.

As a continuous thin film having a higher refractive index than the light diffraction structure layer, ZnS, TiO ₂ , Al ₂ O ₃ , Sb ₂ S ₃ ,
SiO, TiO, SiO _{2 and the} like can be mentioned. As a continuous thin film having a lower refractive index than the light diffraction structure layer, LiF, M
gF ₂ , AlF _{3 and the} like. Also, if the thickness is 20
When the angle is 0 ° or less, the light transmittance is relatively small.
It can be used as a light reflective layer while being transparent. Further, a transparent synthetic resin having a different refractive index from the light diffraction structure layer, for example, a layer of polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl acetate, polyethylene, polypropylene, or polymethyl methacrylate is used as the light reflective layer. You can also.

The protective layer 9 protects the surface of the light diffraction structure 8 which is typically a hologram layer, facing the outside, and has transparency, abrasion resistance, abrasion resistance, heat resistance, A resin having durability such as chemical resistance or stain resistance is suitable. Such resins include, for example, ionizing radiation-curable resins, specifically, polyurethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, and the like. To adjust the crosslinking density, a polyfunctional or monofunctional monomer may be added and used, and if necessary, a known photoreaction initiator and sensitizer may be added and used. In addition, polyene / thiol-based ionizing radiation-curable resins and the like also have excellent abrasion resistance and can be preferably used.

The resin for forming the protective layer 9 as described above may further include a surfactant, an antistatic agent,
Additives such as ultraviolet absorbers can also be added. Also, a small amount of wax or the like may be added in order to secure the slipperiness of the surface. The method for providing the protective layer 9 is as follows.
A diluent or a solvent is added to the resin for forming the protective layer, and mixed or dispersed to prepare a coating liquid for forming the protective layer. After applying by a conventionally known roll coating method or gravure coating method, UV ( UV) irradiation,
Alternatively, the protective layer can be formed by curing the resin by EB (electron beam) irradiation or the like. When an organic solvent is added to the coating solution, it is preferable that after application, first, hot-air drying is performed to remove the organic solvent, and then the resin is cured by irradiation with UV or EB.

The protective layer 9 has a thickness of 0.5 to 0.5.
It is preferable that the thickness be in the range of 4.0 μm. When the thickness of the protective layer is less than 0.5 μm, sufficient abrasion resistance and abrasion resistance cannot be obtained. On the other hand, when the thickness exceeds 4.0 μm, the abrasion resistance is already sufficient. However, the thickness of the transfer layer transferred from the hologram seal or the hologram transfer sheet is increased, and the magnetic recording / reading characteristics may be deteriorated.

In the present invention, as the magnetic recording layer 3,
Ba-ferrite having a plate ratio of 1.5 or more is dispersed in a binder resin as a magnetic material, and has a coercive force of 580 to 7
By using a material having a 20 square oersted and a squareness ratio of 0.85 or more, 8 μm to 25 μm was formed on the magnetic recording layer.
Since it is possible to take a thickness of m, various applications as described above can be achieved using this thickness.

The reason why the lower limit is set to 8 μm is as follows.
When the thickness is less than m, the concealing layer 7 needs a thickness in terms of its function, so that only the concealing layer 7 is formed and other layers (pattern layers and light diffraction structures) cannot be laminated, or other than the concealing layer 7. In addition, the number of layers (or the total thickness) that can be laminated becomes extremely small. Further, the upper limit is set to 25 μm because
If the thickness exceeds 25 μm, the output decrease due to the spacing loss becomes too large, and writing and reading at the same level as that of a normal magnetic card or the like become impossible.

The base material 2 and the concealing layer 7 can be directly laminated on the base material 2 by, for example, applying a coating composition for forming a concealing layer. The material and the concealing layer 7 can be laminated.

The adhesive layer 10 is made of a vinyl chloride resin, a vinyl acetate resin, a vinyl chloride-vinyl acetate copolymer resin, an acrylic resin, a polyester resin, a polyurethane resin, a polyamide resin, or a rubber modified product. Appropriate ones can be selected from among them, and they can be used alone or in a mixture of two or more kinds, and if necessary, a hard resin, a plasticizer, and other additives can be added. The adhesive layer 10 may be laminated on a base material, and each layer may be laminated thereon. Alternatively, the adhesive layer 10 may be laminated on a transfer layer to be transferred onto the base material and applied. When one or both of the objects to be bonded are heat-fusible, the adhesive layer can be omitted.

Adhesive layer 1 formed of the above material
0 can be usually formed by applying the above-mentioned material in the form of a solution in the form of a solution, applying the solution with a roll coater or the like, and drying. The thickness of the adhesive layer 14 is preferably in the range of 0.5 to 5 μm, more preferably in the range of 1.5 to 3 μm.

When forming the magnetic recording medium 1 of the present invention, the concealing layer 7 and the light diffraction structure 8, the concealment layer 7, the pattern layer 5 and the light diffraction structure 8 are applied to the substrate 2 having the magnetic recording layer 3. Are laminated. These may be sequentially and directly laminated by coating or the like, or may be laminated by transfer. However, if each layer is previously laminated on a transfer sheet and can be transferred at once, the production efficiency is further improved. In particular, when a concealing layer and a decorative layer, for example, a pattern layer or a light diffraction structure (for example, a hologram) are formed on a transfer layer of the same transfer sheet, these can be laminated by transfer at a time. become. Note that the embossed characters 6 by embossing may be performed at the time when the lamination of each layer to be laminated is completed.

FIG. 5 is a diagram showing some of such transfer sheets 11. Transfer sheet 11 shown in FIG.
Is provided on the lower surface of the support sheet 12 as necessary, a release layer for imparting a releasability, and a release layer (neither is shown) for facilitating release of the subsequent layers. A transfer layer composed of a protective layer 9, a light diffractive structure layer 8a, a light reflective layer 8b, a concealing layer 7, and an adhesive layer 10 is laminated in order through one or both of the two layers. Things. Each layer can be made of the same material as that already described in the description of each layer of the magnetic recording medium 1.

The release layer is intended to be peeled between the release layer and the transfer layer at the time of transfer. If not, it may not be provided. When a release layer is laminated, it can be formed by a layer in which wax or silicone is mixed with a polyester resin and an isocyanate compound, or a melamine resin layer, and relatively strong adhesion to a support sheet is required.

The release layer has a poor adhesion to the release layer to which the release layer is adhered, or a little to the support sheet when no release layer is involved. Therefore,
Although it depends on the object to be bonded, it is preferable to use a cellulose resin or a polyvinyl butyral resin.

[0061]

EXAMPLES (Example 1) A hologram transfer sheet was prepared as follows. First, a release layer forming composition (1) having the following composition is applied to a corona discharge-treated surface of a biaxially stretched polyethylene terephthalate resin film having a thickness of 25 μm and having one surface subjected to a corona discharge treatment by a gravure reverse coating method. Thus, a release layer having a thickness of 0.5 μm after drying was formed. (Composition for forming release layer (1))-Melamine resin 5 parts by mass-Cellulose acetate resin 1 part by mass-Paratoluenesulfonic acid 0.05 part by mass-Ethyl alcohol 45 parts by mass-Methyl alcohol 25 parts by mass

On the obtained release layer, a protective layer forming composition (2) having the following composition was applied by a gravure reverse coating method, and an ultraviolet irradiation device (two high-pressure mercury lamps having an output of 160 W / cm) was applied. Irradiates 500 mJ of UV light
/ Cm ² to form a protective layer having a thickness of 1 μm after curing. (Composition (2) for forming protective layer)-20 parts by mass of polyurethane acrylate (prepolymer)-100 parts by mass of dipentaerythritol hexaacrylate-5 parts by mass of 2-hydroxyethyl acrylate-1 part by mass of photopolymerization initiator-Sensitization 1 part by mass of agent

On the obtained protective layer, a composition (3) for forming an optical diffraction structure layer having the following composition was applied by a gravure reverse coating method, and after the application, the temperature: 100 ° C., time: 1 minute. After drying by heating, a resin layer having a thickness of 2 μm after drying was formed. (Composition for forming light diffraction structure layer (3)) 40 parts by mass of acrylic resin 10 parts by mass of melamine resin 50 parts by mass of cyclohexanone 25 parts by mass of methyl ethyl ketone

The hologram master is placed on the resin layer obtained as described above so that its mold surface (irregular surface) is in contact with the hologram master, at a temperature of 150 ° C., a pressure of 50 kg / cm ² , and a press time;
After heating and pressurizing under the condition of 1 minute, the hologram master was peeled off, and irregularities of the hologram master were shaped. After shaping, the obtained uneven surface was sputtered to a thickness of 20 n.
A light reflective layer was formed by forming a thin film layer of ZnS m. Further, an adhesive layer forming composition (4) having the following composition was applied on the light reflecting layer by a gravure reverse coating method to form an adhesive layer having a thickness of 2 μm after drying. (Composition for forming adhesive layer (4))-20 parts by mass of vinyl chloride / vinyl acetate copolymer resin-10 parts by mass of acrylic resin-20 parts by mass of ethyl acetate-50 parts by mass of toluene

Subsequently, materials for the card base material and the magnetic recording layer were prepared as follows. First, a magnetic recording layer forming composition (5) having the following composition was applied on the surface of a polyethylene terephthalate resin film having a thickness of 50 μm by a gravure coating method, and the residual magnetic flux density was 1.7 maxwe.
The magnetic recording layer was formed so as to be 11 / cm to obtain a magnetic recording layer transfer sheet. (Composition for forming a magnetic recording layer (5)) Ba ferrite (magnetic powder) (coercive force; 620 Oe, plate ratio: 2.2) 36 parts by mass ・ Urethane resin 12 parts by mass ・ Toluene 18 parts by mass ・ Methyl ethyl ketone 15 parts by mass ・ Methyl isobutyl ketone 15 parts by mass ・ Isocyanate curing agent 4 parts by mass

Using the magnetic recording layer transfer sheet obtained above, heat transfer is performed at a predetermined position on a transparent polyvinyl chloride resin sheet having a thickness of 100 μm for an oversheet of a card, and the magnetic recording layer is laminated on the surface. Got an overseat.

The obtained oversheet having the magnetic recording layer laminated thereon is placed so that the magnetic recording layer is on the upper side, and two 280 μm-thick translucent polyvinyl chloride resin sheets are placed under the oversheet. A transparent polyvinyl chloride resin sheet for oversheet having a thickness of 100 μm on which no magnetic recording layer is laminated is placed at the bottom, and the above four sheets are stacked at a temperature of 150 ° C., a pressure of 25 Kg / cm. ^2. Hot pressing was performed under the condition of pressing time: 15 minutes to obtain a laminate in which four sheets were laminated and the upper surface of the magnetic recording layer formed a continuous plane with the upper surface of the uppermost oversheet.

Using the composition (6) for forming a concealing layer having the following composition, the entire surface of the obtained laminate was applied by a silk screen printing method and dried to form a concealing layer having a thickness of 5 μm after drying. Formed. (Hidden layer forming composition (6))-Acrylic resin 10 parts by mass-Vinyl acetate resin 20 parts by mass-Aluminum powder 50 parts by mass-Pigment 4 parts by mass-Solvent (toluene / cyclohexanone = 1/1) 50 parts by mass Department

Thereafter, a pattern layer composed of characters and pictures was formed by printing on the entire surface of the concealing layer except the magnetic recording layer by ordinary offset printing. Here, the reason why printing was not performed on the magnetic recording layer was to reduce the effect of an increase in spacing loss on writing and reading of information using the magnetic recording layer. Since the thickness of the pattern layer, including color printing and anchor printing therefor, may be about 5 μm, writing and reading of information using the magnetic recording layer is sufficiently possible even if the pattern layer is formed on the magnetic recording layer. is there. The same applies to the following embodiments.

Subsequently, the hologram was transferred to the entire surface including the printing surface using the hologram transfer sheet prepared previously. As described above, on the magnetic recording layer, after obtaining a laminate in which the concealing layer and the hologram were laminated to a thickness of about 10 μm in total, punching was performed at a predetermined position of the laminate to obtain about 86 mm × 54 mm. Got a magnetic card.

(Example 2) The hologram transfer sheet and the light-reflective layer in Example 1 were made in common, and thereafter, instead of forming an adhesive layer, a pattern consisting of characters and pictures was formed by ordinary offset printing. A layer is formed by printing, and thereafter, using the same concealing layer forming composition (6) as used in Example 1, the whole surface of the pattern layer is applied by silk screen printing, dried, and dried. A concealing layer having a thickness of 7 μm was formed to obtain a transfer sheet.

As the card base material, the laminate using the four sheets prepared in Example 1 was previously used without forming a concealing layer, and the transfer using the above transfer sheet was performed. After the transfer, punching was performed in the same manner as in Example 1 to obtain a magnetic card.

(Example 3) The magnetic powder in the magnetic recording layer forming composition (5) used in Example 1 was the same as the magnetic powder in the same mass part of Ba.
Ferrite (coercive force; 620 Oersted, plate ratio;
A magnetic card was obtained in the same manner as in Example 1 except that 3.0) was used.

Example 4 As the magnetic powder in the magnetic recording layer forming composition (1) used in Example 1, the same mass parts of Ba were used.
Ferrite (coercive force; 620 Oersted, plate ratio;
A magnetic card was obtained in the same manner as in Example 1 except that 1.5) was used.

(Comparative Example 1) The magnetic powder in the magnetic recording layer forming composition (1) used in Example 1 was the same as the magnetic powder in the same mass part of Ba.
Ferrite (coercive force; 620 Oersted, plate ratio;
A magnetic card was obtained in the same manner as in Example 1, except that 1.4) was used.

With respect to the magnetic cards of Examples 1 to 4 and Comparative Example 1 obtained above, the squareness ratio was measured using a vibration sample type magnetization characteristic measuring apparatus (model BHV-30, manufactured by Riken Denshi Co., Ltd.). The results of the measurement are shown in Table 1 below. From this result, if the plate ratio is 1.5 or more, the squareness ratio is 0.8
It was confirmed that good magnetization characteristics of 5 or more were obtained.

[0077]

[Table 1]

Example 5 The thickness of the magnetic shielding layer was set to 20 μm.
A magnetic card was obtained in the same manner as in Example 1 except that the above conditions were satisfied.

Example 6 A magnetic card was obtained in the same manner as in Example 1, except that the thickness of the magnetic shielding layer was 3 μm.

(Example 7) A magnetic card was obtained in the same manner as in Example 4, except that the thickness of the magnetic shielding layer in Example 3 was changed to 20 µm.

Comparative Example 2 A magnetic card was obtained in the same manner as in Example 1 except that the thickness of the magnetic shielding layer was changed to 2 μm.

Comparative Example 3 The thickness of the magnetic shielding layer was 21 μm.
A magnetic card was obtained in the same manner as in Example 1 except that the above conditions were satisfied.

With respect to the magnetic cards of Examples 1 to 7 and Comparative Examples 1 to 3 obtained above, a recording method: a frequency modulation method (F2F method), a write current: 100 mA Write density; 210b
it / inch, card transfer speed; 300 mm / sec
The result of reading the written magnetic information with three types of devices A, B, and C having different specifications is shown in Table 2 below.

In the devices A, B, and C, the read magnetic head specifications are common, and the card transport speed (unit: mm / sec) and the maximum readable voltage value (unit: V) of each device are used. Is 300 for device A.
mm / sec, 5 V, 400 mm / sec for device B,
3 V, 300 mm / sec and 4 V in the device C.

From these results, it can be seen that if the plate ratio of the magnetic powder is 1.5 or more and the squareness ratio is 0.85 or more, if the thickness on the magnetic recording layer is 8 μm to 25 μm, good magnetic information can be obtained. It was confirmed that write / read performance was obtained.

On the other hand, in the case of Comparative Example 1, since the squareness ratio was low, the output difference (resolution) between the "0" signal and the "1" signal was large, and as a result, the analog signal read by the device was Information could not be read because peak detection became difficult. In Comparative Example 2, the thickness of the concealing layer was small (the total thickness of the layers on the magnetic recording layer was 8
(less than μm), the magnetic output was too high, the analog signal was saturated, accurate conversion to a digital signal could not be performed, and the device B could not read information. Further, Comparative Example 3
Since the thickness of the concealing layer is large (the total thickness of the layers on the magnetic recording layer exceeds 25 μm), the spacing loss becomes large, sufficient magnetic output cannot be obtained, and information is read. I couldn't do that.

[0087]

[Table 2]

[0088]

According to the first aspect of the present invention, a Ba-ferrite magnetic material having a specific plate ratio, coercive force, and squareness ratio is used. A magnetic recording medium capable of performing writing and reading without any trouble can be provided as well as a structure having a light diffraction structure composed of a layer and a light diffraction structure layer, as in the case of using a normal magnetic material. According to the second aspect of the present invention, there is provided a magnetic recording medium in which writing and reading can be performed without any trouble even in a structure in which a pattern layer is further laminated on a magnetic recording layer, as in the case of using a normal magnetic material. it can. According to the third aspect of the invention, in addition to the effects of the first or second aspect of the invention, it is possible to provide a magnetic recording medium having improved durability due to the lamination of the protective layer. According to the invention of claim 4, in addition to the effect of the invention of claim 3, since the peelable layer has a structure laminated on the protective layer,
A magnetic recording medium having a structure suitable for smoothly transferring an optical diffraction structure having a protective layer can be provided. According to the fifth aspect of the present invention, since the light diffusing structure layer, the light reflecting layer, and the concealing layer are sequentially provided, the light is transferred onto the magnetic recording layer of the magnetic recording medium having a high output and hardly causing a spacing loss. Thus, it is possible to provide a transfer sheet for coating suitable for producing a magnetic recording medium having a high decoration effect by concealing the magnetic recording layer and the light diffraction structure. According to the sixth aspect of the present invention, since the light diffractive structure layer, the light reflective layer, and the pattern layer are sequentially provided, the light is transferred onto the magnetic recording layer of the magnetic recording medium having a high output and hardly causing a spacing loss. Accordingly, it is possible to provide a coating transfer sheet suitable for producing a magnetic recording medium having a high effect of hiding the magnetic recording layer and decorating with the pattern layer. According to the seventh aspect of the present invention, since the light diffractive structure layer, the light reflective layer, the pattern layer, and the concealing layer are sequentially provided, the output is high and the spacing loss is hardly generated on the magnetic recording layer of the magnetic recording medium. It is possible to provide a transfer sheet for coating which is suitable for producing a magnetic recording medium having a high effect of transferring and concealing a magnetic recording layer, and a decorative effect by an optical diffraction structure and a pattern layer. According to the invention of claim 8,
In addition to the effects of any one of claims 5 to 7, since the protective layer is laminated, a transfer sheet for coating that can transfer a transfer layer with improved durability can be provided. Claim 9 or 10
According to the invention, since the transfer layer is accompanied by the peelable layer, it is possible to provide a transfer sheet for coating in which the transfer layer can be smoothly peeled. According to the invention of claim 11, claims 5 to 1 are provided.
In addition to the effects of any of the inventions, there is no need to separately prepare and laminate an adhesive to adhere the transfer layer to the adherend, and it is possible to provide a transfer sheet for coating that can be adhered as it is.

[Brief description of the drawings]

FIG. 1 is a plan view when a magnetic recording medium is a card.

FIG. 2 is a cross-sectional view of a magnetic recording medium to which a shielding layer and an optical diffraction structure are applied.

FIG. 3 is a sectional view of a magnetic recording medium to which a pattern layer is further applied.

FIG. 4 is a sectional view illustrating a laminated structure of a card base material.

FIG. 5 is a cross-sectional view of a transfer sheet for transferring a concealing layer, a pattern layer, a light diffraction structure, and the like.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic recording medium (card) 2 Base material 3 Magnetic recording layer 4 IC module 5 Printing (or pattern layer) 6 Embossed character 7 Concealment layer 8 Light diffraction structure (example: hologram) 9 Protective layer 10 Adhesive layer 11 Transfer sheet 12 Support sheet

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2C005 HA06 HB01 HB04 HB09 HB10 JA02 JA03 KA06 KA08 KA12 5B035 AA00 BA05 BB02 5D006 AA05 AA06 BA06 BA08 BA19 CB01 DA01 FA09

Claims (11)

[Claims] 1. Ba-ferrite having a plate ratio of 1.5 or more is dispersed in a binder resin as a magnetic material, and a coercive force of 5% is obtained.
80 to 720 Oersted, and a concealing layer for concealing at least the magnetic recording layer is laminated on a base material having at least a part of the magnetic recording layer having a squareness ratio of 0.85 or more, and A magnetic recording medium, comprising: a light-reflective layer and a light-diffraction structure layer sequentially stacked from above on the base including the cover layer. 2. A pattern layer is laminated on a part of the substrate including the concealing layer, and a lower layer is formed on the substrate including the concealing layer or the pattern layer. 2. The magnetic recording medium according to claim 1, wherein a light reflective layer and a light diffraction structure layer are sequentially laminated from the side. 3. The magnetic recording medium according to claim 1, wherein a protective layer is laminated on the light diffraction structure. 4. The magnetic recording medium according to claim 3, wherein a peelable layer is laminated on the protective layer. 5. A transfer sheet for coating, wherein a light diffractive structure layer, a light reflective layer, and a concealing layer are sequentially laminated on a release surface of a release support sheet. 6. A transfer sheet for coating, wherein a light diffractive structure layer, a light reflective layer, and a pattern layer are sequentially laminated on a release surface of a release support sheet. 7. A method according to claim 1, wherein the light-reflective layer and the concealing layer are
The transfer sheet for coating according to claim 5, wherein a pattern layer is laminated. 8. The coating according to claim 5, wherein a protective layer is laminated between the release surface of the release support sheet and the light diffraction structure layer. Transfer sheet. 9. The releasable layer is laminated between the releasable surface of the releasable support sheet and the light diffraction structure layer. Transfer sheet for coating. 10. The transfer sheet for coating according to claim 8, wherein a release layer is laminated between the release surface of the release support sheet and the protective layer. 11. The transfer sheet for coating according to claim 5, wherein an adhesive layer is laminated on the concealing layer.