JP4816895B2 - Magnetic transfer sheet and magnetic recording medium - Google Patents

Description

  The present invention relates to a magnetic transfer sheet. By using the magnetic transfer sheet of the present invention to transfer to a card or ticket made of plastic or paper, a magnetic recording medium such as a magnetic card or a magnetic ticket can be manufactured. Magnetic information can be recorded on this magnetic recording medium, and can be used for, for example, credit cards, securities, certificates, admission tickets, and the like.

  The present invention relates to a magnetic transfer sheet having a function of making it possible to visually confirm the authenticity of a magnetic recording medium that is difficult to forge or tamper with simultaneously with the manufacture of the magnetic recording medium. The present invention also relates to a magnetic recording medium manufactured using this magnetic transfer sheet.

  As magnetic recording media for recording secret information magnetically, for example, credit cards, cash cards and the like are widely known. These credit cards, cash cards, and the like are affixed with a hologram or the like so that the card can be visually discriminated. A hologram is an OVD that is a medium with optical changes. It has a characteristic that its color and image pattern change depending on the viewing angle, so it is beautiful and decorative, and its production is complicated and has special equipment. Because it is necessary, it has excellent anti-counterfeiting effects.

Such a magnetic card with a hologram is produced by transferring a hologram of a transfer sheet having a hologram to a part different from the magnetic part on the card in a magnetic card provided with a magnetic part on a card base. Is done. That is, it is manufactured using a transfer sheet in which a release protective layer, a hologram layer, and an adhesive layer are laminated in this order on a transfer sheet support. In addition, there is also a type of magnetic recording medium with a hologram in which a hologram and a magnetic part are integrated by using a magnetic transfer sheet having a hologram on a card not provided with a magnetic recording layer. This is a magnetic recording medium using a transfer sheet in which a hologram and a magnetic tape are integrated by laminating a peeling protective layer, a hologram layer, a magnetic recording layer, and an adhesive layer in this order on a support (for example, patents). Reference 1).
However, in recent years, a forgery of such a hologram has also appeared, and the development of a new forgery prevention technique has been demanded.

  Accordingly, the problem to be solved by the present invention is to provide a magnetic transfer sheet that can solve such problems and a magnetic recording medium manufactured using the magnetic transfer sheet. That is, the magnetic recording medium targeted by the present invention has a higher anti-counterfeit effect and higher decorativeness than conventional magnetic recording media.

According to a first aspect of the present invention, there is provided a magnetic recording medium having a transfer layer including a magnetic recording layer on one side of a support, transferring the transfer layer to a transfer substrate, and peeling and removing the support. A magnetic transfer sheet to be manufactured, and this transfer layer is formed from an ink containing powder coated with reduced titanium dioxide or iron oxide on mica that can be seen in different colors and image patterns depending on the viewing angle. An OVD layer comprising an OVD forming layer and a light reflecting layer that reflects light incident on the OVD forming layer, as seen from the support side, a peeling protective layer, an OVD forming layer, a light reflecting layer, a magnetic recording layer, The magnetic transfer sheet is formed by laminating the adhesive layers in order, and the light reflection layer is provided in an image pattern, and covers a portion between the magnetic recording layer and the OVD formation layer where the light reflection layer does not exist. Block light transmission into the area A magnetic transfer sheet comprising: a蔽層.

  Next, the invention according to claim 2 is characterized in that the light reflecting layer is formed of a metal thin film, and is disposed between the light reflecting layer and the magnetic recording layer, and overlaps the light reflecting layer to form a chemical resistant protective layer. It is provided, It is a magnetic transfer sheet of Claim 1 characterized by the above-mentioned.

  The invention according to claim 4 is the magnetic transfer sheet according to any one of claims 1 to 3, further comprising a printed layer at a position that can be observed after transfer.

  Next, the invention described in claim 5 is a magnetic recording medium with an OVD using the magnetic transfer sheet according to any one of claims 1 to 4 on a substrate such as paper or plastic. The magnetic recording medium is characterized in that the design effect is high while enhancing the prevention effect.

  According to the first aspect of the present invention, since the light reflecting layer is provided not in the whole of the transfer sheet but in a partial image pattern, the light reflecting layer of the magnetic recording medium obtained by transfer is also an image pattern. It becomes a shape. Further, since only a portion of the light reflection layer formed in the image pattern shape can reflect light, for example, when the OVD formation layer is a diffraction grating, the light reflected by the light reflection layer The light reflected from the OVD formation layer interferes with each other to become diffracted light, and the OVD can observe different colors depending on the angle in the form of an image pattern.

  Since the technology for forming the light reflecting layer in such an image pattern is different from the technology for forming OVD, it is extremely difficult to falsify or forge a magnetic recording medium using both of these technologies. .

  According to the invention of claim 2, since the light reflection layer is composed of a metal thin film, the intensity of the reflected light is large, and as a result, bright diffracted light, interference light, etc. can be observed, Its authenticity can be easily determined. Furthermore, since a chemical-resistant protective layer is provided on the light reflecting layer, it is possible to prevent corrosion of the metal thin film and improve durability.

Further, according to the invention described in claim 1, and a hiding layer for blocking transmission of light in the region covering the nonexistent site of the light-reflecting layer a between the magnetic recording layer and the OVD forming layer As a result, the black and brown portions of the magnetic recording layer can be concealed to improve the decoration. If a multicolor printing ink film is applied as the concealing layer, the design can be further improved. In addition, it is very difficult to forge the alignment between the multicolor printing ink film and the image-patterned light reflecting layer with high accuracy, so that it is further difficult to forge the magnetic recording medium.

  According to the invention described in claim 4, since the printing layer is provided at a position where observation is possible after transfer, it is possible to improve the designability after transfer regardless of the presence or absence of the light reflection layer. It becomes.

  According to the fifth aspect of the present invention, tampering / counterfeiting becomes extremely difficult.

  The magnetic transfer sheet according to the present invention comprises a transfer sheet support and a transfer layer. The transfer layer includes a magnetic recording layer and is transferred to a transfer substrate to form a part of the magnetic recording medium. The support holds the transfer layer until transfer, and is peeled off after transfer.

The transfer layer has an OVD layer in addition to the magnetic recording layer. This OVD layer has the ability to wavelength-disperse the reflected light, and different colors and image patterns can be seen depending on the viewing angle. The OVD layer needs to be arranged at a position where it can be visually observed when the magnetic recording medium is manufactured by transferring the transfer layer. In general, since the magnetic recording layer is an opaque layer colored black or brown, the OVD layer needs to be disposed on the magnetic recording layer on the magnetic recording medium. This is a position closer to the support side than the magnetic recording layer on the transfer sheet.

  Various OVDs that can see different colors and image patterns depending on the viewing angle are known. In the OVD of the present invention, the OVD is composed of an OVD forming layer and a light reflecting layer. As the OVD used in the present invention, on the magnetic recording medium, outside light such as room light or sunlight is reflected by the light reflecting layer, and this reflected light is diffracted by the OVD forming layer, so that it varies depending on the viewing angle. The OVD layer is composed of a multilayer thin film in which materials with different refractive indexes are alternately laminated, and a part of the external light is reflected by each thin film layer, and the remaining incident light is reflected by the light reflecting layer. There is a multilayer thin film in which chromatic dispersion is caused by reflection, and different colors are observed depending on the viewing angle. On the magnetic recording medium, the light reflecting layer and the OVD forming layer need to be laminated in this order from the substrate side. On the transfer sheet, the OVD forming layer and the light reflecting layer are arranged in this order from the support side.

  The light reflecting layer of OVD used for the transfer sheet of the present invention needs to be provided in an image pattern, that is, partially. For this reason, the diffracted light is generated in this image pattern. In addition, at the portion where the light reflecting layer does not exist, the upper and lower layers of the light reflecting layer are in direct contact.

  The transfer sheet of the present invention may have another layer in addition to the OVD forming layer, the light reflecting layer, and the magnetic recording layer in the transfer layer. For example, a peeling protective layer for protecting the OVD layer and the magnetic recording layer from external damage such as rubbing during carrying and chemical damage due to living substances after the transfer while facilitating peeling of the support after transfer. And an adhesive layer for adhering the transfer sheet to the substrate to be transferred.

  In addition, when the light reflecting layer is composed of a metal thin film, the transfer sheet is provided with a chemical-resistant protective layer on top of the light reflecting layer to protect the light reflecting layer from acids and alkalis, improving its durability. You can also make it.

  It is also possible to provide a printed layer that improves the design of the magnetic recording medium. The printed layer may be in a position where it can be observed after transfer, but is, for example, a portion positioned above the OVD layer after transfer. That is, on the transfer sheet, it is located closer to the support than the OVD layer.

(Structure of magnetic transfer sheet)
Next, the structure of the transfer sheet according to the present invention will be described with reference to the drawings.

  FIG. 1A is a cross-sectional view showing a first example of a transfer sheet according to the present invention. This transfer sheet includes a support 1 and a transfer layer 2 laminated on one side of the support 1.

  The transfer layer 2 has a magnetic recording layer 23 in its layer structure.

  Further, the transfer layer 2 has an OVD layer 22 in its layer structure, and this OVD layer 22 is composed of an OVD formation layer 221 and a light reflection layer 222. As shown in the plan view of FIG. 1B, the light reflecting layer 222 is provided in an image pattern formed by a large number of stars and connecting portions connecting these stars. Note that an image pattern of a large number of stars and an image pattern of a connecting portion connecting the stars are formed by different diffraction gratings, and a broken line in FIG. 1B indicates a boundary line.

  In addition to this, the transfer layer includes a peeling protective layer 21 that facilitates peeling from the support after transfer, and protects the OVD layer 22 and the magnetic recording layer 23 from abrasion after transfer, and an adhesive layer 24. Yes.

  The stacking order of these layers is, in order from the support 1 side, the peeling protective layer 21, the OVD forming layer 221, the light reflecting layer 222, the magnetic recording layer 23, and the adhesive layer 24.

  Next, FIG. 2 is a cross-sectional view showing a second example of the transfer sheet, which is provided with a chemical-resistant protective layer 25 having the same shape as that of the light reflection layer 222 on top of the light reflection layer 222. This is the same as the transfer sheet shown in 1A. The chemical resistant protective layer 25 is provided between the light reflecting layer 222 and the magnetic recording layer 23.

  FIG. 3A is a cross-sectional view showing a third example of the transfer sheet. The concealing layer 26 is provided in a region between the OVD forming layer 221 and the magnetic recording layer 23 and covering a portion where the light reflecting layer 222 does not exist. Others are the same as those of the transfer sheet shown in FIG. 1A. The concealing layer 26 can be provided in the same region as the portion where the light reflecting layer 222 does not exist, but may be provided in a wider region. In FIG. 3A, the concealment layer 26 is provided in a region wider than the portion where the light reflection layer 222 does not exist. Therefore, the end of the light reflection layer 222 and the end of the concealment layer 26 overlap each other. The concealing layer 26 is located between the light reflecting layer 222 and the magnetic recording layer 23 in the portion where both are overlapped.

  In FIG. 3A, the concealing layer 26 is composed of two-color ink films 261 and 262, and is provided in a region that covers the portion where the light reflecting layer 222 does not exist by both of the two-color ink films 261 and 262. ing. The two-color printing ink films 261 and 262 form a cross-shaped printed pattern as shown in FIG. 3B, and need to be aligned with the light reflecting layer 222 in the form of an image pattern. It becomes possible to effectively prevent forgery of the medium.

  Next, FIG. 4 is a cross-sectional view showing a fourth example of the transfer sheet, which includes a chemical-resistant protective layer 25 and a concealing layer 26, and is otherwise the same as the transfer paper sheet shown in FIG. 1A.

  FIG. 5A is a cross-sectional view showing a fifth example of the transfer sheet, which includes a printing layer 27, and is otherwise the same as the transfer paper sheet shown in FIG. 1A. By providing the print layer 27 between the peeling protection layer 21 and the OVD formation layer 221, it is necessary to align the image pattern with the light reflection layer 222. Therefore, the print layer 27 is more effectively used for the magnetic recording medium. It becomes possible to prevent forgery. In the illustrated example, the printing layer 27 is provided so as to overlap the light reflecting layer 222 and has a cross-shaped pattern as can be seen from the plan view of FIG. 5B.

  Next, FIG. 6 is a cross-sectional view showing a sixth example of the transfer sheet, which includes a printing layer 27 and a concealing layer 26, and is otherwise the same as the transfer sheet shown in FIG. 1A. The concealing layer 26 is composed of a single color printing ink film 261.

  Next, FIG. 7 is a cross-sectional view showing a seventh example of the transfer sheet, which includes a printing layer 27 and a chemical-resistant protective layer 25, and the others are the same as the transfer sheet shown in FIG. 1A. FIG. 8 is a cross-sectional view showing an eighth example of the transfer sheet, which includes a printing layer 27, a chemical-resistant protective layer 25, and a concealing layer 26, and is otherwise the same as the transfer sheet shown in FIG. 1A.

(Support 1)
The material and forming method of each layer constituting this transfer sheet will be described.

  First, a resin film can be used as the support 1. As the resin film, a polyethylene terephthalate resin film, a polyethylene naphthalate resin film, a polyimide resin film, a polyethylene resin film, a polypropylene resin film, a heat-resistant vinyl chloride film, or the like can be used. Among these resins, since the heat resistance is high and the thickness is stable, a polyethylene terephthalate resin film can be preferably used.

  Moreover, the film which adjusted the peeling strength of the peeling protection layer 21 by providing a peeling layer in these resin films or performing an easily bonding process can also be utilized as the support body 1. FIG. In addition, a film that has been subjected to processing such as antistatic treatment, mat processing, embossing, or the like can also be used.

(Peeling protection layer 21)
As the peeling protective layer 21, a resin added with a lubricant can be used. As the resin, a thermoplastic resin, a thermosetting resin, a moisture curable resin, an ultraviolet curable resin, an electron beam curable resin, or the like can be used. For example, acrylic resin, polyester resin, and polyamideimide resin. As the lubricant, wax such as polyethylene powder or carnauba wax can be used, and it can be added up to 20 parts by weight. These are formed as a peeling protective layer 21 on the support 1 by a known coating method such as a gravure printing method or a micro gravure method.

(OVD layer 22)
The OVD layer 22 includes at least two layers of an OVD formation layer 221 and a light reflection layer 222. As will be described later, the OVD layer 22 may include other layers.

(OVD formation layer 221)
The OVD forming layer 221 includes a relief type diffraction grating, a volume type diffraction grating, etc., a high refractive index thin film having a refractive index of about 2.0 or more, and a thin film of a low refractive index material having a refractive index of about 1.5. A multilayer thin film or the like obtained by appropriately laminating each of them with an optically appropriate film thickness can be used.

  The relief type diffraction grating has a diffraction grating recorded in the form of a fine uneven pattern on the surface thereof.

  Such a concavo-convex pattern is obtained by, for example, irradiating the surface of the photosensitive resin with two coherent light beams using the two-beam interference method to generate an interference pattern on the surface of the photosensitive resin. Can be formed by recording in a photosensitive resin in the form of irregularities. The interference fringes formed by the two-beam interferometry are called holograms, and any three-dimensional image can be recorded by selecting the two light beams. It is also possible to record so that different images (hereinafter referred to as changing images) can be seen depending on the viewing angle.

  The uneven pattern of the relief type diffraction grating can also be formed by irradiating the surface of the electron beam curable resin with an electron beam and exposing it to stripes constituting the diffraction grating. In this case, since the interference fringes can be controlled for each line, any three-dimensional image or changing image can be recorded in the same manner as the hologram. It is also possible to divide the image into dot-like pixel areas, record different diffraction gratings for each pixel area, and express the entire image with a set of these ancestors. The pixel may be a circular dot or a star-shaped dot.

It is also possible to form the concavo-convex pattern by an induced surface relief forming method. That is, by irradiating an amorphous thin film of a polymer having azobenzene on the chain side with a relatively weak light of about several tens mW / cm ² having a certain wavelength ranging from blue to green, several μm scale As a result, movement of polymer molecules can be caused, and as a result, relief by unevenness can be formed on the surface of the thin film.

  Then, by forming a metal film on the surface of the relief-type master plate having the uneven pattern formed in this way by electroplating, the uneven pattern of the relief-type master plate is duplicated and used as a press plate. Then, the press plate is thermocompression bonded to the resin layer applied on the peeling protection layer 21, and a fine uneven pattern is transferred onto the surface of the resin layer, whereby the OVD forming layer 221 can be obtained.

  As the resin applied to the OVD forming layer 221 using the relief type diffraction grating, a thermoplastic resin, a thermosetting resin, an ultraviolet ray, an electron beam curable resin, or the like can be used. For example, acrylic resins include acrylic resins, epoxy resins, cellulose resins, vinyl resins, and the like. In addition, urethane resins, melamine resins, phenol resins, and the like obtained by adding polyisocyanate as a crosslinking agent to an acrylic polyol or polyester polyol having a reactive hydroxyl group and crosslinking can be used. Further, as the ultraviolet ray or electron beam curable resin, epoxy (meth) acryl, urethane (meth) acrylate, or the like can be used.

  Further, as the OVD formation 221, an optical multilayer interference film that is a multilayer thin film, a layer of cholesteric liquid crystal, an ink containing powder that can see different colors depending on an observation angle, and the like can be used.

  The optical multilayer interference film may be a metal thin film, a ceramic thin film, or a composite thin film formed by combining them with an appropriate number of layers stacked depending on the relationship between the optical characteristics of each layer and the layer combination. For example, when thin films having different refractive indexes are stacked, a high refractive index thin film and a low refractive index thin film may be combined, or a specific combination may be stacked alternately. An optical multilayer interference thin film that exhibits a desired optical effect (here, a structural color) can be obtained by an appropriate combination that satisfies the optical conditions of these layers.

  Examples of materials used for such an optical multilayer interference film are given below. In addition, the numerical value in the parenthesis following the chemical formula indicates each refractive index n.

First, as ceramics, Sb ₂ O ₃ (3.0), Fe ₂ O ₃ (2.7), TiO ₂ (2.6), CdS (2.6), CeO ₂ (2.3), ZnS (2.3), PbCl ₂ (2.3), CdO (2.2), Sb ₂ O ₃ (2.0), WO ₃ (2.0), SiO (2.0), Si ₂ O ₃ (2.5), In ₂ O ₃ (2.0), PbO (2.6), Ta ₂ O ₃ (2.4), ZnO (2.1), ZrO ₂ (2.0), MgO ( 1.6), Si ₂ O ₂ (1.5), MgF ₂ (1.4), CeF ₃ (1.6), CaF ₂ (1.3 to 1.4), AlF ₃ (1.6) , Al ₂ O ₃ (1.6), GaO (1.7), and the like, and metal-based materials include Al, Fe, Mg, Zn, Au, Ag, Cr, Ni, Cu, Si Examples of simple metals or alloys such as That.

  Moreover, as a low refractive index material, for example, among organic polymers, polyethylene (1.51), polypropylene (1.49), polytetrafluoroethylene (1.35), polymethyl methacrylate (1.49), Polystyrene (1.60) and the like. However, the numerical value in parenthesis shows each refractive index n here.

  At least one kind is selected from these high refractive index materials or metal thin films having a light transmittance of 20 to 70%, and at least one kind is selected from low refractive index materials. Only a specific wavelength is absorbed or reflected.

A multilayer thin film that generates optical wavelength interference is formed by laminating as a thin film by selecting from the above materials based on optical properties such as refractive index, reflectance, and transmittance, weather resistance, and interlayer adhesion. To do. As a forming method, a known method capable of controlling the film thickness, the film forming speed, the number of stacked layers, the optical film thickness, or the like can be used. For example, a vacuum deposition method, a sputtering method, a CVD method, or the like. The optical film thickness is an amount given by n · d, where n is the refractive index and d is the film thickness.

  In addition, the cholesteric liquid crystal layer has a helical structure in which the constituent molecules are optically active and nematically uniaxially oriented in the thin layer, but are twisted at a certain angle in a certain direction between adjacent layers. is doing. The pitch is distributed from several hundred nm to infinity. Due to this helical structure, the cholesteric liquid crystal selectively reflects light having a wavelength corresponding to the helical pitch and has a brilliant color from blue to red.

  Next, examples of the powder capable of seeing different colors depending on the observation angle include layered substances such as mica. A powder obtained by coating this mica with reduced titanium dioxide or iron oxide can be used. These exhibit chromatic dispersion performance by the so-called flip-flop effect. By forming these powders into ink and using a known printing method or coating method, a layer having wavelength dispersion performance can be formed.

(Light reflection layer 222)
The light reflecting layer 222 does not need to be provided in direct contact with the OVD forming layer 221, but when the OVD forming layer 221 is a relief type diffraction grating, the light reflecting layer 222 is provided in direct contact with the concavo-convex pattern. There is a need. In this case, the light reflected by the light reflecting layer 222 becomes diffracted light as it is.

  As the light reflection layer 222, a metal thin film can be preferably used in terms of high reflection luminance. Examples of the metal include Al, Sn, Cr, Ni, Cu, Au, and brass. And this metal thin film can be formed using a vacuum film-forming method. As the vacuum film forming method, a vacuum deposition method, a sputtering method, or the like can be applied, and the thickness may be controlled to about 5 to 1000 nm.

  Further, a transparent thin film having a high refractive index can be used as the light reflecting layer 222. The transparent thin film preferably has a refractive index greater than 0.2 by the refractive index of the OVD formation layer 221. For example, the transparent thin film is a thin film made of a transparent material having a refractive index of 2.0 or more.

Examples of such a transparent material include Sb ₂ O ₃ (refractive index n = 3.0), Fe ₂ O ₃ (n = 2.7), TiO ₂ (n = 2.6), Cds (n = 2.6), CeO ₂ (n = 2.3), ZnS (n = 2.3), PbCl ₂ (n = 2.3), CdO (n = 2.2), Sb ₂ O ₃ (n = 2.0), WO ₃ (n = 2.0), SiO (n = 2.0), Si ₂ O ₃ (n = 2.5), In ₂ O ₃ (n = 2.0), PbO ( n = 2.6), Ta ₂ O ₃ (n = 2.4), ZnO (n = 2.1), ZrO ₂ (n = 2.0), and the like. Then, the thin film can be formed using a vacuum film forming method. The thickness of the thin film may be about 5 to 1000 nm.

  Alternatively, a thin film may be formed by printing ink containing metal powder or transparent material powder. In this case, the powder preferably has a particle diameter of 500 nm or less. The thickness of the thin film is preferably 0.1 to 20 μm, and a known printing method such as a gravure printing method, a flexographic printing method, or a screen printing method can be used as a printing method.

  The light reflecting layer 222 can be processed into an image pattern by the following method.

That is, the first method is a method using the above-described printing method. In the second method, the light reflecting layer 2 is formed by overlaying a mask having an image pattern-shaped opening on the OVD forming layer 221.
In this method, the light reflection layer 222 is formed into an image pattern by vacuum forming the film 22.

  In the third method, first, a solvent-soluble resin layer is provided in a negative pattern, and the light-reflective layer 222 is uniformly formed on the entire surface by covering the solvent-soluble resin layer. The solvent-soluble resin layer is dissolved and removed, and at the same time, the remaining light-reflective layer 222 is formed into an image pattern by removing the light-reflective layer 222 superimposed on the solvent-soluble resin layer. It is.

  In the fourth method, first, a resin layer that is easily peeled off from the OVD formation layer 221 is provided on the OVD formation layer 221 in a negative pattern, and the light reflection layer is uniformly coated over the resin layer. After forming 222, it is removed by transferring it to an adhesive roll or adhesive paper in a negative pattern by pressing it against an adhesive roll or adhesive paper. As a result, the light reflecting layer 222 remains in an image pattern. is there.

  In the fifth method, the light reflecting layer 222 is uniformly formed on the entire surface, a chemical-resistant resin layer is provided on the light reflecting layer 222 in an image pattern, and an alkaline or acidic etching solution is applied. In this method, the exposed light reflection layer 222 is dissolved and removed. In this case, after processing the light reflecting layer 222 into an image pattern, the chemical-resistant resin layer may be removed, but it can be left as it is and used as the chemical-resistant protective layer 25.

  In the sixth method, a photosensitive resin layer is formed on the light reflecting layer 222 formed uniformly on the entire surface, exposed and developed in an image pattern, and then an alkaline or acidic etching solution is applied. In this method, the exposed light reflecting layer 222 is dissolved and removed. Also in this case, the remaining photosensitive resin layer can be left as it is and used as the chemical-resistant protective layer 25.

  The seventh method is a method in which the remaining light reflection layer 222 is formed into an image pattern by irradiating the light reflection layer 222 formed uniformly on the entire surface with laser light.

  This image pattern may be a random pattern with no clear meaning, but it is also possible to give recognizable information to this image pattern as a pattern such as a picture, figure, pattern, letter, number, symbol, etc. is there.

(Magnetic recording layer 23)
As the magnetic recording layer 23, the same magnetic recording layer used in a normal magnetic card, magnetic tape or the like can be used. For example, a magnetic coating prepared by dispersing magnetic powder such as γ-Fe ₂ O ₃ , cobalt-coated γ-Fe ₂ O ₃ , and barium ferrite in a binder is uniformly applied by a known method. Can do.

(Adhesive layer 24)
Any adhesive layer 24 may be used as long as it adheres to the substrate to be transferred by heat and pressure, and a known heat-sensitive adhesive material can be used.

(Chemical-resistant protective layer 25)
As the chemical-resistant protective layer 25, it is desirable to immerse it in a 1.5N sodium hydroxide aqueous solution at 40 to 50 ° C. for 60 seconds so that the coating film does not change. In this case, the chemical-resistant protective layer 25 is formed on the light reflection layer 222 formed uniformly on the entire surface, and the aqueous sodium hydroxide solution is used as an etching solution, and is immersed in this etching solution for 5 to 30 seconds. The light reflecting layer 222 can be processed into an image pattern.
The chemical resistant protective layer 25 is desirably made of a resin having a glass transition temperature of 150 ° C. or higher. In this case, it is possible not only to protect from acids and alkalis, but also to protect the deformation of the light reflecting layer 222 from high temperatures. Such chemical and heat resistant resins include polycarbonate resin (Tg. 140-150 ° C.), polyarylate resin (Tg. 193 ° C.), polysulfone resin (Tg. 190 ° C.), polyether sulfone resin (Tg .225 ° C.), polyetherimide resin (Tg. 200 ° C. or higher), cyclic polyolefin copolymer (Tg. 171 ° C.), modified norbornene resin (Tg. 171 ° C.), polyamideimide resin (Tg. 200 ° C. or higher) And polyimide resin (Tg. 250 ° C. or higher). In addition, a thermosetting resin, a moisture curable resin, an ultraviolet curable resin, or an electron beam curable resin may be used.
In addition, a filler, a filler, a coloring agent, etc. can be added up to 40% by weight when the specific gravity of these resins is 1. When added over 40% by weight, the dispersibility is deteriorated, the coating film strength is lowered, and the heat resistance may be inferior. In addition, the fluidity of the coating liquid becomes low and the printability deteriorates due to drying on the plate, and those additives in the coating liquid settle or aggregate during storage or coating. Etc.

(Other layers)
As the concealing layer 26, an opaque printing ink that prevents light transmission can be used. Such printing inks are well known.

  The printing layer 27 can also use a well-known printing ink, but it is not limited to an opaque ink, and a transparent ink may be used.

(Magnetic recording medium)
After the magnetic transfer sheet according to the present invention is stacked on a transfer substrate and bonded by thermocompression bonding, the support 1 is peeled and removed, whereby the transfer layer can be transferred to produce a magnetic recording medium. Any material can be used as the substrate to be transferred, and examples thereof include a plastic card substrate made of a polyvinyl chloride resin, a polyester resin, or a polyethylene terephthalate resin. Moreover, paper, synthetic paper, etc. can be used as a base material.

  The magnetic recording medium thus manufactured has a magnetic recording layer on a substrate. The magnetic recording medium also has an OVD layer and a magnetic recording layer that can be seen in different colors depending on the viewing angle. The OVD layer is composed of an OVD forming layer and a light reflecting layer. , The light reflecting layer and the OVD forming layer are laminated in this order.

  FIG. 9 is a cross-sectional view of a magnetic recording medium manufactured using the first example (see FIG. 1) of the magnetic transfer sheet according to the present invention. That is, the adhesive layer 24, the magnetic recording layer 23, the light reflecting layer 222, the OVD forming layer 221, and the peeling protective layer 21 are laminated in this order on the substrate 3, and the light reflecting layer 222 is configured in an image pattern. Yes.

  FIG. 10 is a cross-sectional view of a magnetic recording medium manufactured using the second example (see FIG. 2) of the magnetic transfer sheet according to the present invention. In this example, a chemical resistant protective layer 25 having the same shape and shape as the light reflecting layer 222 is provided between the light reflecting layer 222 and the magnetic recording layer 23 so as to overlap the light reflecting layer. This is the same as the magnetic recording medium shown.

  FIG. 11 is a cross-sectional view of a magnetic recording medium manufactured using the third example (see FIG. 3) of the magnetic transfer sheet according to the present invention. In this example, a concealing layer 26 is provided in a region covering a portion where the light reflecting layer 222 does not exist between the OVD forming layer 221 and the magnetic recording layer 23, and the rest is the same as the magnetic recording medium shown in FIG. .

FIG. 12 is a cross-sectional view of a magnetic recording medium manufactured using the fourth example (see FIG. 4) of the magnetic transfer sheet according to the present invention. In this example, a chemical-resistant protective layer 25 and a concealing layer are provided. The rest is the same as the magnetic recording medium shown in FIG.

  FIG. 13 is a cross-sectional view of a magnetic recording medium manufactured using a fifth example (see FIG. 5) of the magnetic transfer sheet according to the present invention. In this example, a printing layer 27 is provided between the peeling protection layer 21 and the OVD formation layer 221. The rest is the same as the magnetic recording medium shown in FIG.

  FIG. 14 is a cross-sectional view of a magnetic recording medium manufactured using the sixth example (see FIG. 6) of the magnetic transfer sheet according to the present invention. In this example, the printing layer 27 and the concealing layer 26 are provided, and the others are the same as those of the magnetic recording medium shown in FIG.

  FIG. 15 is a cross-sectional view of a magnetic recording medium manufactured using the seventh example (see FIG. 7) of the magnetic transfer sheet according to the present invention. In this example, the printing layer 27 and the chemical-resistant protective layer 25 are provided, and the others are the same as those of the magnetic recording medium shown in FIG.

  FIG. 16 is a cross-sectional view of a magnetic recording medium manufactured using the eighth example (see FIG. 8) of the magnetic transfer sheet according to the present invention. In this example, the printing layer 27, the chemical-resistant protective layer 25, and the concealing layer 26 are provided, and the others are the same as those of the magnetic recording medium shown in FIG.

Next, the present invention will be described by way of examples. The magnetic transfer sheet of this example is the fourth example described above. First, a transparent polyethylene terephthalate (commonly called PET) film having a thickness of 25 μm was used as the support 1.

  On one side of this support 1, an ink comprising the following composition was applied and dried to form a release protective layer 21 having a thickness of 2 μm.

  Next, after applying and drying ink composed of the following composition to form a layer having a thickness of 1 μm, a press plate for forming a diffraction grating is hot-pressed by a roll embossing method to generate a diffraction grating on the surface. Unevenness was formed to form an OVD formation layer 221.

  Next, an aluminum vapor deposition film is uniformly formed with a film thickness of 50 nm on the entire surface of the OVD formation layer 221 by a vacuum vapor deposition method, and further, an ink composed of the following composition is printed in an image pattern shape to obtain aluminum. A chemical-resistant protective layer 25 having a thickness of 1 μm was formed on the deposited film. Then, it is immersed for 10 seconds in a bath containing a 1.5N sodium hydroxide aqueous solution kept at 50 ° C., and the chemical-resistant protective layer 25 serves as a mask, and the aluminum deposited film is exposed without the chemical-resistant protective layer 25 being present. The part which has been removed was removed by etching. Furthermore, it was immersed in a 0.1N hydrochloric acid aqueous solution for neutralization treatment, then washed with water and dried. In this way, the light reflection layer 222 formed of an aluminum vapor deposition film in an image pattern and the chemical-resistant protective layer 25 overlapped with the light reflection layer 222 and having the same shape as the light reflection layer were formed.

  Next, a star shape is printed at a thickness of 1.5 μm by a screen printing method on the portion where the light reflecting layer 222 does not exist to form a concealing layer 262, and then the entire portion where the light reflecting layer 222 does not exist is printed. The area to be covered was printed with a thickness of 1.5 μm by a screen printing method to form a concealing layer 261.

  Next, a magnetic ink composed of the following composition is applied to the entire surface and dried to form a magnetic recording layer 23 having a thickness of 8 μm. Finally, an ink composed of the following composition is applied and dried to adhere to a thickness of 3 μm. Layer 24 was formed to produce the desired magnetic transfer sheet.

"Peeling protective layer ink composition"
Polyamideimide resin (Tg. 250 ° C.) 19.2 parts by weight Polyethylene powder 0.8 parts by weight Dimethylacetamide 45.0 parts by weight Toluene 35.0 parts by weight “OVD forming layer ink composition”
Urethane resin 20.0 parts by weight Methyl ethyl ketone 50.0 parts by weight Ethyl acetate 30.0 parts by weight “Chemical-resistant protective layer ink composition”
Modified norbornene resin (Tg. 171 ° C.) 20.0 parts by weight Precipitated barium sulfate (specific gravity 5.5) 10.0 parts by weight Methyl ethyl ketone 40.0 parts by weight Toluene 30.0 parts by weight “Magnetic recording layer ink composition”
γFe2 O3 magnetic powder 30.0 parts by weight Vinyl acetate copolymer 3.0 parts by weight Polyurethane elastomer 20.0 parts by weight Methyl ethyl ketone 15.0 parts by weight Toluene 15.0 parts by weight “Adhesive layer ink composition”
Vinyl chloride vinyl acetate copolymer resin 15.0 parts by weight Acrylic resin (Tg. 20 ° C.) 10.0 parts by weight Silica 1.0 part by weight Methyl ethyl ketone 44.0 parts by weight Toluene 30.0 parts by weight Next, this magnetic transfer sheet Was cut into the shape of a magnetic tape, stacked on a plastic card substrate, transferred with a hot roll transfer machine having a plate surface temperature of 120 ° C., and then the support 1 was peeled off to produce a magnetic card.

  Looking at the magnetic tape of the obtained magnetic card, the light reflecting layer 222 is formed in a complicated shape such as stripes, stars, letters, etc., thereby making it more than a conventional magnetic recording medium having a light reflecting layer on the entire surface. I found it difficult to counterfeit.

  In addition, a print image of the concealment layer 262 is applied to a portion where the light reflection layer 222 does not exist, which is not only beautiful, but also because the positions of the light reflection layer 222 and the concealment layer 262 are combined with high accuracy. Furthermore, counterfeiting was difficult.

  In addition, since it has a chemical-resistant protective layer 25, it can be confirmed that it has excellent resistance even when immersed in a 20% aqueous acetic acid solution or a 5% aqueous sodium hydroxide solution for 1 hour in the durability test, and the appearance is not significantly changed. It was.

FIG. 1A is a cross-sectional view showing a first example of a magnetic transfer sheet according to the present invention. FIG. 1B is a plan view thereof. Sectional drawing which shows the 2nd example of the magnetic transfer sheet which concerns on this invention. FIG. 3A is a cross-sectional view showing a third example of the magnetic transfer sheet according to the present invention. FIG. 3B is a plan view thereof. Sectional drawing which shows the 4th example of the magnetic transfer sheet which concerns on this invention. FIG. 5A is a sectional view showing a fifth example of the magnetic transfer sheet according to the present invention. FIG. 5B is a plan view thereof. Sectional drawing which shows the 6th example of the magnetic transfer sheet which concerns on this invention. Sectional drawing which shows the 7th example of the magnetic transfer sheet which concerns on this invention. Sectional drawing which shows the 8th example of the magnetic transfer sheet which concerns on this invention. Sectional drawing of the magnetic-recording medium manufactured using the 1st example of a magnetic transfer sheet. Sectional drawing of the magnetic-recording medium manufactured using the 2nd example of a magnetic transfer sheet. Sectional drawing of the magnetic-recording medium manufactured using the 3rd example of a magnetic transfer sheet. Sectional drawing of the magnetic-recording medium manufactured using the 4th example of a magnetic transfer sheet. Sectional drawing of the magnetic-recording medium manufactured using the 5th example of a magnetic transfer sheet. Sectional drawing of the magnetic-recording medium manufactured using the 6th example of a magnetic transfer sheet. Sectional drawing of the magnetic-recording medium manufactured using the 7th example of a magnetic transfer sheet. Sectional drawing of the magnetic-recording medium manufactured using the 8th example of a magnetic transfer sheet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transfer material support 2 ... Transfer layer 21 ... Detach protection layer 221 ... OVD formation layer 222 ... Light reflection layer 23 ... Magnetic recording layer 24 ··· Adhesive layer 25 ··· Chemical resistant protective layer 26 ··· Concealment layer 261 ··· Concealment layer 262 ··· Concealment layer 27 ··· Print layer 3 ··· Base material

Claims (4)

A magnetic transfer sheet for producing a magnetic recording medium having a transfer layer including a magnetic recording layer on one side of a support, transferring the transfer layer to a transfer substrate, and peeling and removing the support. In the transfer layer, an OVD formation layer formed from an ink containing powder obtained by coating mica with reduced titanium dioxide or iron oxide, which can see different colors and image patterns depending on the observation angle, and the OVD formation A magnetic layer having an OVD layer made up of a light reflecting layer that reflects light incident on the layer, and laminated in the order of a peeling protective layer, an OVD forming layer, a light reflecting layer, a magnetic recording layer, and an adhesive layer as seen from the support In the transfer sheet, the light reflection layer is provided in an image pattern , and the transmission of light is blocked between the magnetic recording layer and the OVD forming layer and covering the region where the light reflection layer does not exist. and characterized in that it comprises a masking layer Magnetic transfer sheet that.   2. The magnetism according to claim 1, wherein the light reflecting layer is formed of a metal thin film, and further includes a chemical-resistant protective layer between the light reflecting layer and the magnetic recording layer and overlapping the light reflecting layer. Transfer sheet. Magnetic transfer sheet according to claim 1 or 2, characterized in that comprises a print layer on observable position after the transfer. A magnetic recording medium, wherein the magnetic transfer sheet according to any one of claims 1 to 3 is transferred to paper, a film, a card or the like.

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