JP2002103860A - Magnetic recording media - Google Patents

Abstract

(57) Abstract: In a magnetic recording medium such as a card having a concealing layer or a concealing layer and a decorative layer on a magnetic recording layer, the thickness of the concealing layer or the total thickness of the concealing layer and the decorative layer is increased. Another object of the present invention is to provide a magnetic recording medium that does not cause cracks in embossed characters. SOLUTION: A particle size of 4 is formed on a magnetic recording layer 3 on a base material 2.
It contains spherical or flaky particles of a metal or alloy exhibiting a metal color of μm to 20 μm, and has a thickness of 0.5 μm to 1 μm.
A 5 μm concealing layer 7 is laminated, and a pattern layer 7, a light diffractive structure 8 and the like are laminated thereon.
By making the total thickness of 5 μm to 25 μm etc.
Cracks in embossed characters were prevented. The magnetic recording layer 3 is made of Ba-ferrite having a plate ratio of 1.5 or more and has a coercive force of 5%.
Those having an 80 to 720 Oe and a squareness ratio of 0.85 or more are preferred.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called "concealed magnetic recording medium" in which a magnetic recording layer held by a magnetic recording medium such as a card is concealed by a concealing layer containing particles having high concealing properties. More specifically, when the thickness of the concealing layer or the pattern layer on the concealing layer increases, cracks (hereinafter referred to as “embossed character cracks”) appearing in the embossed characters (hereinafter simply referred to as embossed characters) during embossing. ) Is improved and an improved magnetic recording medium is prevented.

[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). As described above, by covering with a coating film having a high concealing property, there is an advantage that a free design which is not restricted by the magnetic recording layer can be realized.

However, embossed characters are often formed on magnetic recording media. For example, in the case of credit cards and savings cards of financial institutions,
The name of the contractor or depositor, card number, expiration date, etc. are formed by embossed characters, and by applying carbon paper and a pressure roller to this embossed character, the information of the embossed character is transferred on the slip. You. Since embossed characters are used in this way, the size of the characters is usually about 3 to 5 mm, and the height is 0.36 to 0.48 m.
It is formed by performing a very deep embossing process of about m.

Therefore, when an embossed character is to be formed, the embossed character is likely to be cracked on the surface of the magnetic recording medium 1. This tendency is conspicuous when the concealing layer is thick, or a pattern layer is formed on the concealing layer. In this case, when the total thickness of the concealing layer and the pattern layer is increased, it becomes conspicuous. However, the concealing layer requires a certain thickness or more in order to ensure concealing properties, and the pattern layer also increases in thickness if multi-color printing is performed on the printing effect. It was difficult to reduce.

[0006]

According to the present invention, in a magnetic recording medium such as a card having a concealing layer or a concealing layer and a pattern layer on the magnetic recording layer, the thickness of the concealing layer or the thickness of the concealing layer and the pattern layer is reduced. It is an object of the present invention to provide a magnetic recording medium in which cracks in embossed characters do not occur even when the total thickness increases.

[0007]

The object of the present invention is to reduce the thickness of the concealing layer or the total thickness of the concealing layer and the pattern layer in addition to the particle size range of the metal or alloy particles for concealing dispersed in the concealing layer. By providing one or both,
Solved.

According to a first aspect of the present invention, there is provided a laminate having a magnetic recording layer on at least a part of a substrate having embossing suitability, and a concealing layer laminated on a substrate including the magnetic recording layer, The concealing layer has a particle size of 4 μm to
Metal or alloy fine particles exhibiting a metal color of 20 μm are dispersed as a main component and have a thickness of 0.5 μm to 15 μm.
m, wherein an embossed character is formed by embossing in an area of the laminate where the concealing layer is laminated.
The second invention comprises a laminate having a magnetic recording layer on at least a part of a substrate having embossing suitability, and at least a concealing layer and a pattern layer being laminated on a substrate including the magnetic recording layer. The concealing layer is a layer in which fine particles of a metal or alloy exhibiting a metal color having a particle size of 4 μm to 20 μm are dispersed as a main component in a binder resin, and the total thickness of the concealing layer and the pattern layer is 5 μm to 25 μm
Wherein a raised character is formed by embossing in an area of the laminate where the concealing layer and the pattern layer are laminated. A third invention comprises a laminate having a magnetic recording layer on at least a portion of a substrate having embossing suitability, and at least a concealing layer and a pattern layer being laminated on a substrate including the magnetic recording layer. The concealing layer is a layer having a thickness of 0.5 μm to 15 μm in which fine particles of a metal or alloy exhibiting a metal color having a particle size of 4 μm to 20 μm are dispersed as a main component in a binder resin, and the concealing layer is A magnetic recording medium, wherein the total thickness of the pattern layer is 5 μm to 25 μm, and embossed characters are formed in an area of the laminate where the concealing layer and the pattern layer are laminated. It is about.
A fourth invention relates to the magnetic recording medium according to the second or third invention, wherein the pattern layer is a printing layer. A fifth invention relates to the magnetic recording medium according to the second or third invention, wherein the pattern layer has an optical diffraction structure. The sixth invention is
In the second or third invention, the present invention relates to a magnetic recording medium, wherein the pattern layer has a two-layer structure of a printing layer and a light diffraction structure from a lower layer side. Seventh
The present invention relates to the magnetic recording medium according to any one of the first to sixth inventions, wherein the fine particles are in a scale shape. An eighth invention relates to the magnetic recording medium according to any one of the first to sixth inventions, wherein the fine particles are spherical.

[0009]

FIG. 1A is a plan view showing a credit card which is an example of an application example of a magnetic recording medium 1 according to the present invention, and FIG. 1B is a diagram showing the positions of patterns and holograms. It is a figure showing a relation. In the example shown in FIG. 1A, the magnetic recording medium 1 has a magnetic recording layer 3 laminated on a card base material 2 and a non-contact IC module 4 embedded at another position. The entire surface including the recording layer and the IC module 4 is covered with a concealing layer 7, and a transparent hologram 8 (a pattern is indicated by a broken line) is laminated on the entire surface. Further, the magnetic recording medium 1 is provided with a card name “ABCD CARD” and a print 5 (or pattern layer) for giving an arbitrary design between the transparent hologram 8 and the concealing layer 7. Are provided with embossed characters (embossed characters by embossing) 6 on a laminated body in which is laminated.

The magnetic recording layer 3 in the magnetic recording medium 1 shown in FIG. 1 may be basically any type, but in a preferred embodiment of the present invention, in addition to the concealing layer, Since the pattern layer 5 or the pattern layer 5 and the optical diffraction structure (for example, hologram) 8 are laminated, it is practically difficult to read recorded information with a magnetic recording layer having a low output. For this reason, as the magnetic recording layer, Ba-ferrite having a plate ratio of 1.5 or more is dispersed in a binder resin as a magnetic material, the coercive force is 580 to 720 Oersted, and the squareness ratio is 0.85 or more. It is preferable to use one.

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 may be any of various known ones. Can be selected.

FIGS. 2 to 4 are cross-sectional views for explaining a typical embodiment of the magnetic recording medium 1 of the present invention, all of which are shown as examples of a card. If
It shows 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 and the pattern layer 5 are sequentially laminated on the substrate 2 having the magnetic recording layer 3 as described above, and the base 2, the concealing layer 7, An embossed character 6 is formed on a laminate composed of the pattern layer 5 and the pattern layer 5. The embossed character 6 has a convex shape on the front side (upper side in the figure) and a concave shape on the back side, that is, irregularities extending over the front and back sides.

The magnetic recording medium 1 shown in FIG. 3 has the same relationship as that of FIG. 1 with the base material 2, the magnetic recording layer 3, and the concealing layer 7, but the optical recording medium The difference is that a light diffraction structure (for example, a hologram) 8 having a laminated structure of a reflective layer 8b and a light diffraction structure layer 8a is laminated. The light diffraction structure layer 8a has fine irregularities of the light diffraction structure on the lower surface of the layer 8a as shown by enlarging a portion surrounded by a circle in the drawing. In the structure shown in FIG. 3, a part of the magnetic recording layer 3 is removed again, and the base material 2, the concealing layer 7, the light reflective layer 8a, and the light diffraction structure 8b are removed.
The embossed character 6 composed of the unevenness extending to the front and back is formed on the laminated body of

The magnetic recording medium 1 shown in FIG. 4 has a structure in which the light diffraction structure 8 in FIG. 3 is laminated on the structure shown in FIG. By removing a portion of the layer 3, an embossed character 6 having irregularities extending over the front and back sides is formed on a laminate including the base material 2, the concealing layer 7, the pattern layer 5, the light reflective layer 8 a, and the light diffraction structure 8 b. It was done. The light reflective layer 8a here is
In order to make the lower pattern layer 5 transparent, a transparent type is desirable.

In the description given with reference to FIGS. 2 to 4, the embossed character 6 is formed by removing a certain portion of the magnetic recording layer 3 because the embossed character 6 is usually formed in a stripe-shaped magnetic recording layer. If embossed characters are formed at three places, projections of several hundreds of μm will occur, resulting in a very large spacing loss.
In the case where the magnetic recording layer 3 is laminated on the entire surface or the like, an embossed character may be formed at a certain position of the magnetic recording layer 3.

In the example shown in FIGS. 2 to 4, 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. 5 shows the relationship between the substrate 2 and the magnetic recording layer 3. In both FIGS. 5 (a) and 5 (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 configuration, the two oversheets 2a and 2a 'are made to have 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. 5A, 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. Also, in FIG. 5B, 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.

5 (a) and 5 (b), 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 as already mentioned.
The plane shape of the magnetic recording layer 3 is not limited to the stripe shape, but may be another shape. In the above-described figure, the position of the magnetic recording layer 3 is slightly inside along one side in the longitudinal direction of the base material 2 of the card. However, other positions may be used. 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.

If the magnetic recording medium 1 has two or more magnetic recording layers, any one of the magnetic recording layers may have the above-mentioned Ba- Ferrite is dispersed as a magnetic material in a binder resin, and has a coercive force of 580 to 720 Oe and a squareness ratio of 0.85.
Although the above is desirable, the other magnetic recording layers may have other magnetic characteristics.

In the present invention, as the substrate 2, a material having embossing suitability is selected and used.
Paper, plastic sheet, metal foil or metal plate, etc. can be used alone or in combination.Select according to the required rigidity, flexibility, processing adhesiveness, or printability etc. I do.

If the magnetic recording medium 1 is a card,
Currently, sheets made of vinyl chloride resin are often used because of their suitability for processing.However, recent reviews of plastic materials have made it possible to use polyolefin resins and embossable non-crystalline polyester, which do not cause problems in incineration at the time of disposal. It is preferable to use a sheet of a system resin or the like. 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 has 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. In the above description, it is preferable that the squareness ratio is 0.85 or more, since a higher output can be obtained as compared with a squareness ratio of less than 0.85.

The above magnetic material includes 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 substrate 2 and the formed product is adhered to the substrate 2 via an adhesive or the like, or is applied to a releasable plastic film. The magnetic recording layer 3 may be formed by transferring the formed product onto the base material 2 or a sheet constituting the base material 2 with an adhesive or the like interposed therebetween. Alternatively, a magnetic substance
The magnetic recording layer 3 can be formed as a thin film by a vacuum deposition method, sputtering, plating, or the like.

As the binder resin used in the ink composition or 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 polyether sulfone may be used.
Alternatively, a system in which the glass transition point increases by a curing reaction with an isocyanate compound or the like can also be used.

The ink composition or the coating composition for forming the magnetic recording layer may further contain a surfactant, a silane coupling agent, a plasticizer, a wax, a silicone oil, carbon, or the like, 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 covering and hiding the magnetic recording layer 3, the concealing layer 7 may be laminated only on the magnetic recording layer 3 at a minimum. Be concealed. However, since anyone knows that the magnetic recording medium 1 such as a card has the magnetic recording layer 3, if the concealing layer 7 conforming to the contour of the magnetic recording layer 3 is formed, the position of the magnetic recording layer 3 becomes clear. Will be transformed.

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 preferable to cover the entire surface of the substrate 2 because the position of the magnetic recording layer 3 becomes more unclear. In addition, the magnetic recording layer 3 is derived from the hue of the magnetic material and is generally colored dark, which greatly hinders the design of a small card. It is preferable that the concealing layer 7 is laminated on the entire surface of the substrate.

Although concealment may not be strictly speaking, the concealing layer 7 may be provided in a pattern, and the magnetic recording layer 3 is physically visible from the gap between the concealing layers 7 in the pattern. However, the presence of the magnetic recording layer 3 is not clear unless the boundary between the magnetic recording layer 3 and the surrounding base material is seen through the gap.
Providing the concealing layer in this way is also considered to be in the category of "concealing at least the magnetic recording layer".

The concealing layer 7 is made of a composition in which particles of a metal or an alloy exhibiting a metal color such as gold or silver are dispersed as a main component in a binder resin. It may contain a highly opaque pigment such as titanium. As the material of the metal or alloy particles, in the present invention, the same metal as used when forming the light reflective layer with a metal thin film, that is, Cr, F
e, Co, Ni, Cu, Ag, Au, Ge, Al, M
g, Sb, Pb, Cd, Bi, Sn, Se, In, G
Metals such as a or Rb, or alloys containing these metals as main components can be used.

When the thickness of the concealing layer 7 is in the range of 0.5 μm to 15 μm, even if the total thickness of the concealing layer 7 and the other decorative layers is 5 μm or more, When the particle size was 4 μm or more, it was found that emboss cracking did not occur. Therefore, metal or alloy particles having a particle size of 4 μm or more may be used, but embossing cracks may be good, but as the particle size increases, the degree of filling of the metal or alloy particles in the concealing layer decreases, and The tendency for the property to decrease increases.

In the above description, when the thickness of the concealing layer 7 is less than 0.5 μm, there is a great possibility that the thickness may become uneven during the formation of the layer and the concealing property may not be ensured.
If it exceeds 15 μm, even if the metal or alloy particles exhibiting a metallic color are made large, the tendency to easily cause embossing cracks cannot be avoided. When a pattern layer or an optical diffraction structure is laminated on the concealing layer, the total thickness affects whether or not embossing cracks occur. When the thickness is 0.5 μm or more, embossing cracks do not occur even if the total thickness of the concealing layer and the decorative layer is 5 μm or more. The reason why the concealing layer is thinner than the value of the particle size is that the thickness of only the coating portion ignoring the particles is measured as the thickness of the concealing layer. Here, the particle size of the metal or alloy particles exhibiting a metal color refers to an average particle size, and specifically, a laser diffraction type particle size distribution analyzer (manufactured by Shimadzu Corporation, sold-20).
00J) by the laser diffraction / scattering method.

As the metal or alloy particles, various shapes can be used. Practical ones are spherical or scale-like. Here, the term "spherical" includes an almost spherical one in addition to a true spherical one. Further, the flake shape is also called a flake shape, and refers to a flake having a sufficiently large diameter with respect to the thickness of the flake. The external shape of the scaly particles is not limited to a circular shape, but is generally indefinite, and the diameter / plate thickness ratio (= aspect ratio) is 10 or more, and more preferably 20 or more.
From the viewpoint described in the next paragraph, this aspect ratio is preferably as large as possible. However, when the aspect ratio is extremely large, the ink composition or the coating composition for forming a concealment layer, which will be described later, is liable to be broken when preparing the concealment layer. In this case, the aspect ratio may be 200 or less, more preferably 100 or less. In the examples described later, the one having an aspect ratio of 50 is used.

Since the spherical particles have higher mechanical strength than the scaly particles, they can be sufficiently kneaded when preparing the ink composition or the coating composition for forming the concealing layer. There is an advantage that a composition having excellent properties such as coating suitability can be obtained. The flaky particles are randomly oriented in the ink composition or coating composition for forming a concealing layer described below, but the thickness of the coating film obtained by actually applying these compositions is comparable to the diameter of the flakes. Otherwise, the diameter direction of the scale becomes parallel to the application direction of the coating film. Therefore, compared to the case of using spherical particles, even if the amount of particles used is small,
There is an advantage that a sufficient concealing property can be obtained. Also, using flaky particles, compared to using spherical particles,
There is an advantage that even if the thickness of the coating film is much thinner, the same degree of concealment can be obtained.

Regarding the concealing property, from a practical point of view, a concealing layer in which the particle size of metal or alloy or the thickness of the layer is changed is formed on an oversheet for a card so that white paper and black paper are in contact with each other. It was judged whether there was no concealing property or not by judging whether the boundary between the white paper and the black paper was visible or not. As a result of repeating such a test, it was found that under the above-mentioned conditions, if the particle size was 20 μm or less, the concealability was practically satisfied.

The concealing layer 7 is formed by adjusting the binder resin, fine particles of metal or alloy exhibiting a metal color such as gold or silver, a concealing agent such as titanium dioxide if necessary, and adjusting the hue of the appearance of the concealing layer. A coloring agent such as a dye or a pigment, and other additives are mixed with a solvent and a diluent, and dissolved or dispersed, using a known ink composition or a coating composition for forming a concealing layer, using a known coating method. The method can be performed by applying the composition onto the magnetic recording layer 3 on the base material 2 by a coating method, for example, a gravure coating method, a roll coating method, a knife edge method, and the like, and curing by drying or the like. Alternatively, the magnetic recording layer 3 may be coated on an object to be coated other than the base material and then formed with an adhesive or the like.
May be 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 an adhesive formed on a peelable object to be coated.

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, polyes Le resins, polyurethane resins or polyvinyl butyral resin, can be used.

Further, the ink composition or the coating composition for forming the concealing layer may be added with a fine powder such as titanium dioxide, alumina, or microsilica having a magnetic head cleaning effect, if necessary. 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 is usually a layer having a pattern such as a character or a pattern formed by a printing method, or a colored solid layer (= solid layer). From the forming method, the pattern layer 5 can be said to be a printing layer. When the magnetic recording layer 3 is laminated on a part of the base material, the pattern layer 5 may not be laminated above the magnetic recording layer 3, but may be laminated. The pattern layer 5 may be composed of a single layer, but may be composed of two layers or four layers including three primary colors of yellow, red, and blue or black as described with reference numerals 5a, 5b, and 5c in FIG. It may be composed of three or four layers formed of colors. Further, in order to secure the adhesiveness, it may be laminated on the base material 2 or the magnetic recording layer 3 via a primer layer.
In addition, the pattern layer 5 may have a cut-out shape although the dots and small shapes are formed in a separated shape or connected.

More specifically, in addition to printing, printing such as ink jet or electrophotography, or a printing-like technique once to form a single pattern layer, a multilayer technique is obtained by applying the technique a plurality of times. The pattern layer 5 can be used. 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.
The thickness of the pattern layer is 0.5 μm to 2 μm if it is a single layer.
In general, the thickness is about 1 to 2 μm per printing color. The number of layers varies depending on the number of printing colors, the number of special colors, and the like. Although it is possible to make the pattern layer thicker, it is not necessary to make the pattern layer thicker if the concealing layer is an underlying layer for the purpose of concealment. Therefore, the thickness is about 0.5 μm to 10 μm or less, usually 5 μm or less. The pattern layer 5 itself is more easily deformed than the concealing layer 7 and inherently less likely to cause embossing cracks. However, if the lower concealing layer 7 is broken, the pattern layer 5 is not formed in other parts than the cracks. Is well adhered to the concealing layer 7, and as a result, the pattern layer 5 tends to be stretched at the portion where the lower concealing layer 7 is cracked, so that the pattern layer 5 is easily broken.

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.

Since such an optical diffraction structure also has a pattern in appearance, it can be said that it is one of the pattern layers 5. The light diffraction structure 8 is usually such that the light diffraction structure layer 8a is on the upper side (= observer side) and the light reflective layer 8b is laminated on the lower surface.

As a material 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 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 a release layer is formed on the support sheet. 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 since it has mass productivity and can reduce the cost. The thickness of such a light diffraction structure layer 8a is preferably in the range of 0.1 to 6 μm, and more preferably in the range of 0.1 to 4 μm. The light diffractive structure 8 is composed of the light diffractive structure layer 8a and the very thin light reflective layer 8b, so that the light diffractive structure 8 is easily deformed and inherently hard to cause embossing cracks, but if the underlying concealing layer 7 is broken. Since the light diffractive structure 8 is well adhered to the concealing layer 7 (in some cases, via the pattern layer 5) in portions other than the cracks, as a result, the light diffractive structure 8 is Tends to be stretched at the cracked portion, making it easier to crack.

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 opposite side of the light diffraction structure layer from the observation side. 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 diffractive structure layer, the light diffractive structure 8 needs to have transparency in order to secure the visibility thereof, and the light diffractive structure 8 is made of a transparent thin film. It is preferable to use a transparent type.

When forming a 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 the 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.

In the magnetic recording medium 1 of the present invention, it is preferable to improve the durability of the surface by laminating a protective layer on the outermost surface. As a protective layer, it has transparency, scratch resistance,
A resin having durability such as abrasion resistance, heat resistance, chemical resistance, or stain resistance is suitable. For example, it can be formed using an ionizing radiation-curable resin.

Specific examples of the ionizing radiation curable resin include:
Polyurethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, and the like, which may be used by adding a polyfunctional or monofunctional monomer to adjust the viscosity or crosslink density to each prepolymer, Further, if necessary, a known photoreaction initiator and sensitizer may be added for use. In addition, polyene / thiol-based ionizing radiation curable resins and the like also have excellent abrasion resistance and can be preferably used.

If necessary, additives such as a surfactant, an antistatic agent, and an ultraviolet absorber may be added to the ionizing radiation-curable resin. Also, a small amount of wax or the like may be added in order to secure the slipperiness of the surface. Further, the protective layer is prepared by adding a diluent or a solvent to the resin for forming the protective layer, mixing or dispersing to prepare a coating liquid for forming the protective layer, and using a conventionally known various roll coating method or gravure coating method. After application, the resin can be formed by curing the resin by UV (ultraviolet) irradiation, 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 thickness of such a protective layer is 0.5-4.
It is preferable to set the range to 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, it is not preferable because the thickness of the entire magnetic recording medium increases, and the magnetic recording / reading characteristics may decrease.

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 Oersted and a squareness ratio of 0.85 or more, it is possible to obtain a thickness of 8 μm to 25 μm on the magnetic recording layer, which was difficult to realize conventionally. Thus, various applications as described above can be achieved. If the upper limit of 25 μm is exceeded, the output decrease due to spacing loss becomes too large, and writing and reading become virtually 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. It can also be laminated.

The adhesive layer is made of vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, acrylic resin, polyester resin, polyurethane resin,
Appropriately selected from a polyamide resin or a rubber modified product, etc., and formed alone or in a mixed system of two or more types, further adding a hard resin, a plasticizer, and other additives as necessary. can do. The adhesive layer
The layers may be laminated on a base material and the respective layers may be laminated thereon. Alternatively, the layers 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.

The adhesive layer formed of the above-mentioned material can be usually formed by applying the above-mentioned material as a solution coating solution, applying the solution with a roll coater or the like, and drying. The thickness of the adhesive layer 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, after forming the concealing layer 7 on the base material 2 having the magnetic recording layer 3, the pattern layer 5, the light diffraction structure 8 or the pattern layer 5 is formed. Then, the light diffraction structure 8 is laminated. If necessary, a protective layer is further laminated. Each of these layers is successively directly applied by coating or the like.
Alternatively, the layers may be laminated by transfer. However, if the layers are previously laminated on a transfer sheet and can be transferred at once, the production efficiency is further improved. In particular, if the concealing layer and the decorative layer, for example, one or both of the pattern layer and the light diffraction structure (for example, hologram) are formed as the transfer layer of the same transfer sheet, these layers can be formed at once. Transfer enables lamination.

The embossed characters 6 are formed at the end of the lamination of each layer to be laminated, and the obtained laminate is brought into contact with an embossed mold of a required character or pattern, heated by a hot press, and It is formed by pressing. Although the embossed character in the present invention is not considered to be limited in any way, it is preferable that the embossed character has a size and an embossed height which are already used in this field due to regulations and customs.

The size of the embossed character is 2 to 4 m in width.
m, vertical; about 3-5 mm, line width 0.3-
It is about 0.5 mm. Such an embossed character is used, for example, by using an embossing machine for a credit card (manufactured by Data Card Co., Ltd., DC9000) and using JIS X6.
The embossing height specified by 301 is 0.40-0.
It is formed by hot-pressing while setting conditions so as to obtain 48 mm. Note that coloring may be performed on the tops of the protrusions of the embossed character, and so-called tipping may be performed to make the embossed character more visible.

[0072]

EXAMPLES (Production Procedure A) A card base material and a magnetic recording layer transfer sheet were prepared as follows. First, the thickness 50
A composition (1) for forming a magnetic recording layer having the following composition was applied to the surface of a polyethylene terephthalate resin film having a thickness of μm by a gravure coating method, and the residual magnetic flux density was 1.7 m.
A magnetic recording layer was formed so as to have an axwell / cm, and a magnetic recording layer transfer sheet was obtained. (Composition for forming magnetic recording layer (1)) 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, a 100 μm thick
m was transferred to a predetermined position on a transparent polyvinyl chloride resin sheet to obtain an oversheet having a magnetic recording layer laminated on the surface.

The obtained oversheet on which the magnetic recording layer is laminated 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. Pressing time: hot pressing under the condition of 15 minutes, four sheets are laminated, and the upper surface of the magnetic recording layer forms a continuous surface with the upper surface of the oversheet on the uppermost surface. I got a body.

Using the composition (2) for forming a concealing layer having the following composition by a silk screen printing method, and drying the whole of the surface of the obtained laminate on the side where the magnetic recording layer is provided, and drying.
A hidden layer having a thickness of 5 μm after drying was formed. The composition for forming a concealing layer to be used hereinafter uses the composition of the following composition for forming a concealing layer (2) as it is, or mixes 50 parts by mass of aluminum powder (particle size: 10 μm). At a certain point, the composition has a composition in which the material of the metal powder to be used, the shape of the particles constituting the powder, or the particle size is changed while maintaining the compounding mass part. (Hiding layer forming composition (2)) Acrylic resin 10 parts by mass Vinyl acetate resin 10 parts by mass Aluminum powder (particle size: 10 μm) 50 parts by mass Pigment 4 parts by mass Solvent (toluene / cyclohexanone = 1/1) 50 parts by mass

Thereafter, a colored layer having a thickness of 1 μm is further formed on the entire surface of the concealing layer except for the magnetic recording layer by offset printing using a normal offset ink.
Punched at a predetermined position on the laminate, about 86 mm x 54 mm
Got a magnetic card.

According to the above-mentioned production procedure A, the material of the metal particles in the concealing layer, the shape and particle size of the particles, the thickness of the concealing layer, the thickness of the decorative layer (here, the colored layer) were changed, and A magnetic card of a comparative example was manufactured, and the magnetic card thus obtained was added to an embossing machine (product number;
DC9000) to form embossed characters.

(Manufacturing procedure B) Example 1 described later
1. In Comparative Examples 11 and 12, Example 34, Comparative Examples 26 and 27, the following hologram transfer sheet was prepared, and the magnetic properties of the laminated body for a card substrate were prepared in the same manner as in Production Procedure A. A magnetic concealing layer and a colored layer (1 μm) are laminated on a recording layer, and a transfer layer of a hologram transfer sheet, that is, an adhesive layer, a light reflection layer, a hologram forming layer, a protective layer, and a release resin The layer stack was transferred to form the embossed characters. Therefore, the first embodiment described above
1, In Comparative Examples 11 and 12, Example 34, and Comparative Examples 26 and 27, the decorative layer refers to a combination of the colored layer and the transfer layer of the hologram transfer sheet. However,
In each of the examples and comparative examples, magnetic cards were manufactured by changing the shape and the particle size of the metal particles in the concealing layer.

(Preparation of Hologram Transfer Sheet) The release layer forming composition (3) having the following composition was gravure reverse-coated on the corona discharge-treated surface of a 25 μm-thick biaxially stretched polyethylene terephthalate resin film subjected to a one-sided corona discharge treatment. It was applied by a coating method to form a release layer having a thickness of 0.5 μm after drying. (Composition (3) for forming a release layer)-5 parts by mass of melamine resin-1 part by mass of cellulose acetate resin-0.05 parts by mass of paratoluenesulfonic acid-25 parts by mass of methyl alcohol-45 parts by mass of ethyl alcohol

Next, a protective layer forming composition (4) having the following composition was applied onto the release layer by a gravure reverse coating method, and was applied with an ultraviolet irradiation device (two high pressure mercury lamps having an output of 160 W / cm). UV irradiation 500mJ / c
Irradiation was performed under the condition of m ² to form a protective layer having a thickness of 1 μm after curing. (Composition for forming protective layer (4))-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-1 part by mass of sensitizer Parts by mass

Further, a hologram layer forming composition (5) having the following composition was applied on the protective layer by a gravure reverse coating method to form a hologram forming layer having a thickness of 2 μm after drying. (Composition for forming hologram layer (5)) ・ Acrylic resin 40 parts by mass ・ Melamine resin 10 parts by mass ・ Cyclohexanone 50 parts by mass ・ Methyl ethyl ketone 25 parts by mass

Using a hologram master having hologram irregularities on the surface of the hologram-forming layer,
50 ° C., pressure; 50 kg / cm ² , and press time;
The irregularities of the hologram master were shaped under a condition of 1 minute to form a hologram layer. A ZnS thin film layer having a thickness of 20 nm was formed on the uneven surface of the obtained hologram layer by a sputtering method to obtain a light reflective layer.

Finally, an adhesive layer forming composition (6) having the following composition was applied on the light reflective layer by a gravure reverse coating method to form an adhesive layer having a thickness of 2 μm after drying. Thus, a hologram transfer sheet was obtained. (Composition for forming adhesive layer (6))-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

Using the hologram transfer sheet obtained above, the hologram transfer sheet was transferred onto the colored layer having the laminated structure of the card base material / concealing layer / colored layer obtained in Example 1, and punched into a predetermined size. Then, a magnetic card having a hologram in which a base material / concealing layer / coloring layer / adhesive layer / light reflecting layer / hologram layer / protective layer were sequentially laminated was obtained. The thickness of each layer on the substrate is
Concealing layer: 5 μm, coloring layer: 1 μm, adhesive layer: 2 μm,
Light reflective layer; 20 nm, hologram layer; 2 μm, and protective layer; 1 μm, for a total of about 11.5 μm.

The following Tables 1 to 3 show each of the examples,
7 shows the results of visually evaluating the concealability of the concealing layer and the cracks of embossed characters in the magnetic cards obtained in Comparative Examples. In Tables 1 to 3, に お け る in the evaluation of “cracked embossed characters” means that there is no cracked embossed character, and × means that there is cracked embossed character. In the evaluation of “concealing property”, ○ indicates that the concealing property by the concealing layer was good and the position of the magnetic recording layer could not be determined, and × indicates that the concealing property by the concealing layer was insufficient and the position of the magnetic recording layer was insufficient. Means that can be determined.

[0086]

[Table 1]

[0087]

[Table 2]

[0088]

[Table 3]

[0089]

According to the first aspect of the present invention, fine particles of a metal or alloy exhibiting a metal color having a particle size of 4 to 20 μm are dispersed as a main component in a binder resin, and the thickness is 0.5 to 15 μm. Since it has a concealing layer of
It is possible to provide a magnetic recording medium in which the lower magnetic recording layer is concealed and the embossed character portion is free from cracks in the embossed character. According to the invention of claim 2, a concealing layer in which fine particles of a metal or alloy having a metal color having a particle size of 4 μm to 20 μm are dispersed as a main component in a binder resin,
And a total thickness of the concealing layer and the pattern layer is 5 μm to 25 μm, so that the lower magnetic recording layer is concealed and the embossed character portion has no cracked embossed character. Can be provided. According to the invention of claim 3, the particle diameter in the binder resin is 4 μm to 20 μm.
0.5 μm to 15 μm in which fine particles of a metal or alloy exhibiting a metal color of μm are dispersed as a main component.
Since the total thickness of the concealing layer and the pattern layer is 5 μm to 25 μm, the lower magnetic recording layer is securely concealed by the concealing layer, and the embossed portion in the embossed character portion is provided. A magnetic recording medium without character breakage can be provided. According to the invention of claim 4, in addition to the effect of the invention of claim 2 or 3, since the pattern layer is a printing layer,
It is possible to provide a magnetic recording medium capable of providing a printed layer with an excellent appearance consisting of an intended color and / or pattern, or both. According to the fifth aspect of the invention, in addition to the effects of the second or third aspect, since the pattern layer has a light diffraction structure, the pattern layer has an excellent appearance due to the hue and pattern peculiar to the light diffraction structure, and has an excellent light appearance. It is possible to provide a magnetic recording medium having a forgery prevention effect peculiar to the diffraction structure.
According to the invention of claim 6, in addition to the effect of the invention of claim 2 or 3, since the pattern layer has a two-layer structure of a printing layer and a light diffraction structure from the lower side, it is based on the presence of the printing layer. The printed layer can provide an excellent appearance consisting of the intended color or pattern, or both, and also has an excellent appearance due to the hue and pattern specific to the light diffraction structure, and A magnetic recording medium having an anti-counterfeiting effect unique to an optical diffraction structure can be provided.
According to the invention of claim 7, in addition to the effect of any one of claims 1 to 6, in addition to the use of scale-like particles as fine particles, while having sufficient hiding properties, the amount of particles used It is possible to provide a magnetic recording medium having a small number or a thin coating film of the concealing layer. According to the invention of claim 8, in addition to the effects of any one of claims 1 to 6, in addition to the use of spherical fine particles, the ink composition for forming a concealing layer has high mechanical strength of the particles. Or when preparing the coating composition,
Since sufficient kneading can be performed, a uniform coating film can be obtained, and thus a magnetic recording medium having a concealing layer with uniform performance can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram when a magnetic recording medium is a card.

FIG. 2 is a cross-sectional view of a card having a pattern layer on a hiding layer.

FIG. 3 is a cross-sectional view of a card having a light diffraction structure on a concealing layer.

FIG. 4 is a cross-sectional view of a card having a pattern layer and a light diffraction structure on a hiding layer.

FIG. 5 is a sectional view showing a base material of the card.

[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

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C005 HA01 JA02 JA08 JA18 JA19 JA26 KA02 KA06 KA09 KA16 KA37 KA40 KA48 KA51 LA03 LA11 LA27 LA28 LA29 2K008 AA13 EE04 FF11 FF17 GG05 5D006 AA04 AA05 AA06 DA01

Claims (8)

[Claims] 1. A laminate having a magnetic recording layer on at least a portion of a substrate having embossing suitability, and a concealing layer laminated on a substrate including the magnetic recording layer, wherein the concealing layer is A layer having a thickness of 0.5 μm to 15 μm in which fine particles of a metal or alloy exhibiting a metal color having a particle size of 4 μm to 20 μm are dispersed as a main component in the binder resin, and the concealment layer of the laminate is laminated. A magnetic recording medium characterized in that an embossed character is formed in a defined area. 2. A laminate comprising a magnetic recording layer on at least a part of a substrate having embossing suitability, and at least a concealing layer and a pattern layer laminated on a substrate including the magnetic recording layer, The concealing layer is a layer in which fine particles of a metal or alloy exhibiting a metal color having a particle size of 4 μm to 20 μm are dispersed as a main component in a binder resin, and the total thickness of the concealing layer and the pattern layer is 5 μm. ~ 25 μm
A magnetic recording medium, wherein an embossed character is formed in an area of the laminate where the concealing layer and the pattern layer are laminated. 3. A laminate comprising a magnetic recording layer on at least a part of a substrate having embossing suitability, and at least a concealing layer and a pattern layer laminated on the substrate including the magnetic recording layer, The concealing layer has a thickness of 0.5 μm in which fine particles of a metal or alloy exhibiting a metal color having a particle size of 4 μm to 20 μm are dispersed in a binder resin as a main component.
m to 15 μm, wherein the total thickness of the concealing layer and the pattern layer is 5 μm to 25 μm, and embossed characters are formed in an area of the laminate where the concealing layer and the pattern layer are laminated. A magnetic recording medium. 4. The magnetic recording medium according to claim 2, wherein the pattern layer is a printing layer. 5. The magnetic recording medium according to claim 2, wherein the pattern layer has an optical diffraction structure. 6. The magnetic recording medium according to claim 2, wherein the pattern layer has a two-layer structure of a printing layer and an optical diffraction structure from the lower layer side. 7. The magnetic recording medium according to claim 1, wherein the fine particles have a scale shape. 8. The magnetic recording medium according to claim 1, wherein the fine particles are spherical.