JP2001331111A - Information recording medium and information recording label - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information recording medium formed by superposing a light diffraction structure, such as a hologram, and a rewritable layer on a base material and to provide a label which enhances the durability of the hologram, etc., makes the recording of the rewritable layer easily visible and allows the easy formation of such structure on the base material. SOLUTION: This information recording medium is formed by successively laminating an adhesive layer 7, a light reflective layer 2, the light diffraction structure 3, the rewritable layer 6 and a protective layer 7 on the base material 1. The label for forming the information recording medium is obtained by successively forming the rewritable layer 6 and the protective layer 7 the top surface of the transparent base material 5 and the light diffraction structure 3, the light reflective layer 2 and the adhesive layer 8 on the under surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rewritable type such as a transparent / opaque type of polymer / organic low molecular weight dispersion or a leuco dye or a liquid crystal on a light diffraction structure such as a hologram. The present invention relates to an information recording medium such as a card having an information recording section in which (= rewritable) color-forming layers are overlapped.

[0002]

2. Description of the Related Art Various information recording media for recording individual information updated each time in a visible state are known.
For example, in the retail business, the number of points and other information are recorded on the surface of a card in order to give points according to the purchase amount of a customer and to give preferential treatment according to the points. Alternatively, the information recorded on the magnetic recording layer or the IC module of the information recording medium is displayed in a visible state.

[0003] The term "card" is a commercial point of view in which global agreements are made between concerned parties.
54mm x 86mm, unified to the size of a business card
Refers to the degree.

[0004] Incidentally, information recorded on an information recording medium has an economic value or other value directly or indirectly, and thus is likely to be an object of forgery or falsification of a person making an illegal attempt. , On the side that issues information recording media,
Various countermeasures against counterfeiting and alteration have been taken.

[0005] One of the typical countermeasures for preventing forgery and alteration is the use of holograms. Holograms were previously replicated by recording light interference fringes on an emulsion layer on a glass dry plate, but recently the interference fringes are recorded as irregularities on the surface of the photosensitive resin layer or as high or low density. As a result, the hologram was copied onto an information recording medium, such as a card, to ensure that the information recording medium was genuine. Have been.

Therefore, in order to ensure the authenticity of an information recording medium that records individual information updated each time in a visible state, application of a hologram has been attempted. For example,
JP-A-8-207444 discloses a base material / a reflective thin film layer / a reversible thermosensitive recording layer / a hologram-forming layer having fine irregularities and a transparent thin film layer having a refractive index different from that of the hologram on the minute irregularities. It describes a recording medium comprising a protective layer, and it is said that the hologram has excellent design and anti-tampering properties.

However, according to the above invention, since the hologram is formed near the surface, the hologram is liable to be stained or damaged during repeated use, so that the visibility of the hologram is liable to decrease, and furthermore, the lower layer of the hologram is formed. Since reversible thermosensitive recording is performed, it is necessary to view through the hologram image covering the recorded characters and the like, and there is a disadvantage that the visibility of the recorded characters and the like is lowered, and conversely,
Considering the visibility of the recorded characters and the like, the hologram image has to be simplified.

[0008]

SUMMARY OF THE INVENTION In the present invention, a hologram or other optical diffraction structure and a rewritable layer are formed on a base material so as to improve the durability of the hologram and to record the rewritable layer. The purpose is to make it easy to see. Another object of the present invention is to provide an information recording label in which such an overlaid structure can be easily formed on a substrate.

[0009]

According to the present invention, an optical diffraction structure such as a hologram is laminated on a side closer to a base material of an information recording medium, and a rewritable layer is laminated thereon via a transparent base material. Conventional problems could be solved.
In addition, by using an information recording label in which a rewritable layer is laminated on the upper surface of a transparent base material and an optical diffraction structure is laminated on the lower surface, the above-mentioned information recording medium can be efficiently produced.

According to a first aspect of the present invention, a light diffractive structure comprising at least a light reflective layer and a light diffractive structure layer laminated on a substrate, a transparent substrate, and a rewritable layer are sequentially laminated. The present invention relates to a characteristic information recording medium. The second invention relates to the information recording medium according to the first invention, wherein an adhesive layer 8 is interposed between the substrate and the light diffraction structure. A third invention relates to the information recording medium according to the first or second invention, wherein a protective layer is laminated on the rewritable layer. A fourth invention is characterized in that a rewritable layer is laminated on an upper surface of a transparent substrate, and a light diffraction structure including a light diffraction structure layer and a light reflective layer is laminated on a lower surface of the transparent substrate. And an information recording label. A fifth invention relates to the information recording label according to the fourth invention, wherein an adhesive layer 8 is laminated on a lower surface of the light diffraction structure. A sixth invention relates to the information recording label according to the fourth or fifth invention, wherein a protective layer is laminated on an upper surface of the rewritable layer.

[0011]

1 and 2 are sectional views showing the structure of an information recording medium of the present invention, and FIG. 3 is a sectional view of an information recording label for manufacturing the information recording medium. As shown in FIG. 1, an information recording medium 10 of the present invention basically has a light diffraction structure 4 composed of a light reflective layer 2 and a light diffraction structure layer 3 on a substrate 1, a transparent substrate 5, and The rewritable layers 6 are sequentially laminated. The light diffraction structure 4 and the entire rewritable layer 6 are partially buried in the substrate 1, and the upper surface of the rewritable layer 6 is flush with the upper surface of the substrate 1.

In practice, various layers are often added in consideration of production efficiency and product properties. As shown in FIG. And an adhesive layer 8 may be laminated between them, and a protective layer 7 may be laminated on the uppermost layer. In this case, the upper surface of the protective layer 7 is flush with the upper surface of the substrate 1. In the above description given with reference to FIGS. 1 and 2, the light diffraction structure 4 and the rewritable layer 6 are laminated on a part of the substrate 1. Alternatively, the substrate 1 may be laminated not only on one side but also on both sides. Hereinafter, the information recording medium 10 of the present invention will be described in more detail.

As the substrate 1, polyester such as polyvinyl chloride, polyethylene terephthalate or polyethylene naphthalate, polycarbonate, polyamide,
Polyimide, cellulose diacetate, cellulose triacetate, polystyrene, acrylic, polypropylene, polyethylene, ABS and other resin sheets,
Metal such as aluminum and copper, paper, and impregnated paper such as resin or latex or the like, or a composite sheet can be used. When heat resistance is required, a sheet of an amorphous polyester resin or a blend resin of an amorphous polyester resin and a polycarbonate resin can be used as the substrate 1.

The thickness of the substrate 1 varies depending on the material, but is usually in the range of about 10 μm to 5 mm. The information recording medium 10 also serves as a magnetic card, and the base material 1 is
To comply with the standard, the thickness is 0.7
6 mm. When the base material 1 is formed of polyvinyl chloride (hereinafter, PVC), usually, a white PVC sheet having a thickness of 280 μm is used as a core sheet, two of which are stacked, and a transparent PVC sheet having a thickness of 100 μm is provided on both sides thereof. Are stacked as an oversheet, and a four-layered base material (total thickness 0.76 mm) is laminated by hot pressing or the like. In this case, the magnetic recording layer is made of the transparent P
By being provided in advance in the form of a tape or the entire surface on the surface of a VC sheet (oversheet), even when in the form of a tape, it is pressed into the base material 1 during lamination by hot pressing or the like,
It is integrated and laminated with a smooth surface. In addition, printing may be performed on a surface facing the outside of the core sheet, a surface facing the outside of the oversheet, or the like.

The light diffraction structure 4 comprises the light reflective layer 2 and the light diffraction structure layer 3. As a hologram which is a typical example of the light diffraction structure 4, both a plane hologram and a volume hologram can be used. Specific examples include a relief hologram, a Lippmann hologram, a Fresnel hologram,
Fraunhofer hologram, lensless Fourier transform hologram, laser reproduction hologram (image hologram, etc.), white light reproduction hologram (rainbow hologram, etc.), color hologram, computer hologram, hologram display, multiplex hologram, holographic stereogram, holographic diffraction grating And the like.

Materials for forming the light diffraction structure layer 3 include:
Thermoplastic resins such as polyvinyl chloride, acrylic resin (eg, PMMA), cellulose acetate, nitrocellulose, polystyrene, polycarbonate, unsaturated polyester,
Melamine, epoxy, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth)
Use of thermosetting resins such as acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, and triazine acrylate alone, or a mixture of the above thermoplastic resins and thermosetting resins Further, a thermoformable substance having a radically polymerizable unsaturated group, or a material obtained by adding a radically polymerizable unsaturated monomer to the composition to obtain an ionizing radiation-curable material can be used. other than this,
Photosensitive materials such as silver salts, dichromated gelatin, thermoplastics, diazo photosensitive materials, photoresists, ferroelectrics, photochromic materials, thermochromic materials, and chalcogen glass can also be used.

The light diffractive structure (eg, hologram) can be formed in the light diffractive structure layer 3 using the above-mentioned materials by a conventionally known method. For example, when recording the interference fringes of a diffraction grating or hologram as a relief of surface irregularities, an original plate on which the diffraction gratings or interference fringes are recorded in the form of irregularities is used as a press mold, and a release layer and a protective layer are formed on a sheet. On the protective layer of the laminated sheet in which the layers are sequentially laminated, a coating solution in which the above materials are dissolved or dispersed is gravure coated,
Apply by roll coating, bar coating, etc.
By forming a coating film, stacking an original plate thereon, and applying heat and pressure to both by an appropriate means such as a heating roll, the concavo-convex pattern of the original plate 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 3 as the relief of the surface unevenness is particularly preferable because it has mass productivity and can reduce the cost. The thickness of such a light diffraction structure layer 3 is preferably in the range of 0.1 to 6 μm, and more preferably in the range of 0.1 to 4 μm.

When the interference fringes of a diffraction grating or a hologram are recorded on the surface of the light diffraction structure layer 3 as an uneven relief as described above, the light reflective layer 2 is placed on the relief surface in order to increase the diffraction efficiency. Preferably, it is formed. If a metal thin film of aluminum or the like that reflects light is formed on the relief surface as the light-reflective layer 2, a reflection type light diffraction structure, typically a reflection type hologram, is obtained, and a transparent thin film is formed on the relief surface. If formed, a transparent light diffraction structure, typically a transparent hologram, can be obtained. Whether to use the reflection type or the transparent type can be appropriately selected depending on the purpose. When a non-transparent metal thin film is used as the light-reflective layer 2, the light-reflective layer 2 is
However, in the case of a transparent light-reflective layer 2, the light-reflective layer 2 may be directed to any side. In short, the laminated structure in which the light-reflective layer 2 is laminated on the relief surface of the light-diffractive structure layer 3 may be arranged in such a direction that the light-diffractive structure (typically, a hologram) can be seen from the observation side. When printing is performed on the lower layer of the light diffraction structure layer, it is necessary to have transparency in order to secure the visibility, and it is preferable to use a transparent thin film. In this case, if the lower layer is made of a dark color such as a solid black, the visibility of the light diffraction structure such as a hologram is improved. Further, by selecting the material of the light-reflective layer and using it in combination, the light-reflective layer can be colored to an arbitrary hue.

When the light reflective layer 2 is formed of a metal thin film, Cr, Fe, Co, Ni, Cu, Ag, Au, G
e, Al, Mg, Sb, Pb, Cd, Bi, Sn, S
A metal such as e, In, Ga, or Rb, an oxide thereof, or a nitride thereof is formed alone or in combination. Of these, Al, Cr,
Ni, Ag, Au or the like is particularly preferable. When the light reflective layer 2 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 2, a continuous thin film of a substance having a different refractive index from that of the light diffraction structure layer 3 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 °. Examples of a method for forming a continuous thin film on the relief surface include a thin film forming method such as a vacuum deposition method, a sputtering method, and an ion plating method. The continuous thin film may have a refractive index larger or smaller than that of the light diffraction structure layer, but the difference in the refractive index is preferably 0.3 or more, and the difference is 0.5 or more.
More preferably, it is 1.0 or more.

The continuous thin film having a higher refractive index than the light diffraction structure layer 3 includes ZnS, TiO ₂ , Al ₂ O ₃ , Sb ₂ S ₃
, SiO, TiO, SiO _{2 and the} like. As a continuous thin film having a lower refractive index than the light diffraction structure layer 3, Li
F, MgF ₂ , AlF _{3 and the} like. When the thickness is 200 ° or less, since the light transmittance is relatively small, it can be used as the light reflective layer 2 while being transparent. Further, a transparent synthetic resin having a different refractive index from the light diffraction structure layer 3, for example, a layer of polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl acetate, polyethylene, polypropylene, or polymethyl methacrylate is replaced with the light reflective layer 2. Can also be used.

The transparent substrate 5 serves as a support for supporting each layer when the information recording medium is manufactured by laminating each layer on the substrate 1. It also blocks the rewritable layer 6 on the upper surface and the light diffraction structure 4 on the lower surface of the transparent substrate 5.

The material of the transparent substrate 5 may be selected from those listed as the substrate 1 of the information recording medium 10, such as polyesters such as polyvinyl chloride, polyethylene terephthalate or polyethylene naphthalate, polycarbonate, polyamide, polyimide, cellulose diacetate. And a resin sheet such as cellulose triacetate, polystyrene, acryl, polypropylene, polyethylene, and ABS. In the information recording medium 10, a transparent sheet is selected and used so that the light diffraction structure 4 in the lower layer can be seen through. As the transparent base material 5, a thin material having a thickness of about 5 to 50 μm may be used so as not to make the thickness of the information recording medium excessive.

The rewritable layer 6 is made of any one of three types of materials: (1) a leuco dye system, (2) a polymer / organic low-molecular dispersion system, and (3) a liquid crystal system.

(1) In the case of a leuco dye system, color development / decoloration is based on a combination of a leuco dye and an acidic compound, and a rewritable layer is formed by a composition in which these compounds are mixed with a polymer binder. There are competitive reaction systems using amphoteric compounds and phase separation systems using long-chain alkyl acidic compounds.

In the competitive reaction system, a phenolamine salt is used as an amphoteric compound, and the coloring reaction is performed by a phenol group.
This utilizes the fact that the decoloration reaction proceeds by an amino group. Here, as the leuco dye, a triarylmethane-based compound (a crystal violet lactone in this range is well known), a diphenylmethane-based compound, a xanthene-based compound, a spiro-based compound, a fluoran-based compound, or the like is used. At this time, since the speed of the coloring reaction is faster than the speed of the decoloring reaction, the color is fixed in a colored state when heated and rapidly cooled, and is fixed in a decolored state when heated and gradually cooled. .

In the phase separation system, the compatible state and the incompatible state of the leuco dye and the long-chain alkyl acid compound are controlled by a difference in cooling rate. When the mixture is heated and gradually cooled in a compatible state, phase separation occurs, the mixture becomes incompatible, and the color is erased. Here, as the long-chain alkyl acidic compound, a phenol compound having a long-chain alkyl group or a phosphonic acid compound having a long-chain alkyl group can be used. The long-chain alkyl group preferably has 11 or more carbon atoms in the former case and 14 or more carbon atoms in the latter case.

In actual use, a thermal head usually uses 1/100 of a specific cooling rather than performing special cooling.
After instantaneously heating and heating in the order of 0 seconds,
By cooling at room temperature, "rapid cooling" can be realized, and the above system can be colored. In addition, as for `` cooling down '', if cooling after heating using a heating means having a large heat capacity such as a heat roller, a hot stamp, a heater bar, etc., `` cooling down '' is realized because a given amount of heat is large, Can be erased. In some cases, erasing with a thermal head is also possible by selecting the heating temperature and conditions. In the case of such a leuco rewritable material,
By appropriately selecting the type of leuco dye, black,
It can be colored in various colors such as blue and red.

(2) In the polymer / organic low-molecular dispersion system, a rewritable layer is formed by a composition in which a low-molecular organic material such as a fatty acid is uniformly dispersed in a transparent synthetic resin binder having a film-forming property. To form The layer is heated by a thermal head or the like to a temperature higher than the melting point of the low-molecular organic compound, and then cooled to a white turbid state.

As the binder of the synthetic resin, a resin which is transparent, has a film-forming property, and can uniformly disperse and hold a low-molecular organic substance is preferable. For example, polyvinyl chloride, vinyl chloride-vinyl acetate Examples include vinyl chloride resins such as copolymers, vinylidene chloride resins, acrylic resins, and other polyester resins. As the organic low molecular weight substance, various fatty acids and derivatives thereof can be used. Among them, saturated linear fatty acids having 1 carbon atom are preferable.
Those having a melting point in the range of 0 to 30 and a melting point of 30 to 160 ° C. are preferred, and one or two or more kinds can be used. The use of a low-molecular organic substance having a different melting point, for example, monocarboxylic acid and dicarboxylic acid has an advantage that the temperature range for the transparency can be widened.

(3) In the liquid crystal system, a liquid crystal is prepared by dispersing a smectic liquid crystal in a polymer matrix.
A polymer composite film is formed and used. In this liquid crystal system, the liquid crystal molecules are brought into a random alignment state or an alignment state by using heat and an electric field, and in these states, the properties of light scattering and light transmission are used, respectively. Further, a dichroic dye can be added for the purpose of improving the contrast and coloring, and a rewritable layer having excellent visibility can be obtained.

Any of the above (1) to (3) can be used according to the application. Among them, the leuco dye system of (1) and the liquid crystal system of (3) can perform color display, so that visibility is high. Is better in terms of

In order to efficiently laminate the light diffraction structure 4 and the rewritable layer 6 on the information recording medium 10 or to use the product as a product for a long time after lamination without using the light diffraction structure 4 and the rewritable layer 6, The following layer should be added to. First, an adhesive layer 8 may be interposed between the substrate 1 and the light diffraction structure 4 in order to facilitate adhesion therebetween. The rewritable layer 6 has a recording / repetition
Since the erasing is performed, the protective layer 7 is preferably laminated in order to improve the durability of the surface, particularly the abrasion resistance.

The material forming the adhesive layer 8 is preferably a material having good adhesion to the light diffraction structure 4 and capable of firmly bonding to the substrate 1. Specifically, vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, acrylic resins, polyester resins, polyurethane resins, polyamide resins, rubber modified products, and the like. Suitable ones can be selected from among them, and these can be used alone or in a mixed system of two or more kinds, and can be used by further adding a hard resin, a plasticizer, and other additives as necessary. it can.

The protective layer 7 protects the exposed surface of the rewritable layer, and is preferably made of a resin having transparency, abrasion resistance, abrasion resistance, heat resistance, chemical resistance, contamination resistance and the like. I have. As a resin forming the protective layer 7, in addition to a thermoplastic resin such as an acrylic resin, a polyurethane resin,
A thermosetting resin such as an epoxy resin and a melamine resin, and further, an ionizing radiation-curable resin can be used. Specific examples of the ionizing radiation-curable resin include polyurethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, and the like. These are polyfunctional or polyfunctional in order to adjust the viscosity or crosslink density of each prepolymer. A monofunctional monomer may be added and used, and if necessary, a known photoreaction initiator and sensitizer may be added and used. In addition, polyene / thiol-based ionizing radiation-curable resins and the like also have excellent abrasion resistance and can be preferably used.

If necessary, additives such as a surfactant, an antistatic agent and an ultraviolet absorber may be added to the resin for forming the protective layer 7. Also, a small amount of wax or the like may be added in order to secure the slipperiness of the surface. The protective layer 7 is formed by adding a diluent or a solvent to the protective layer forming resin and mixing or dispersing the diluent or solvent to prepare a protective layer forming coating solution. After applying by the method, UV (ultraviolet) irradiation or E
The protective layer can be formed by curing the resin by B (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 the protective layer 7 is preferably in the range of 0.5 to 4.0 μm. The thickness of the protective layer is 0.5 μm
If less, sufficient scratch resistance and abrasion resistance cannot be obtained,
Further, a thickness exceeding 4.0 μm is not necessary because the wear resistance is already sufficient.

Since the information recording medium 10 of the present invention is obtained by laminating each layer as described above, it can also be manufactured by sequentially laminating each layer on the base material 2. It is preferable to create an information recording label 20 in which the information recording labels are laminated, and to laminate the information recording labels.

FIG. 3 shows a practical structure of the information recording label 20. A rewritable layer 6 and a protective layer 7 are laminated on the upper surface of the transparent substrate 5 from the transparent substrate 5 side. On the lower surface of the transparent substrate 5, a light diffraction structure 4 composed of a light diffraction structure layer 3 and a light reflective layer 2, and an adhesive layer 8 are sequentially laminated from the transparent substrate 4 side. However,
The minimum components of the information recording label 20 include a rewritable layer 6 and a transparent substrate 5 on the upper surface of the transparent substrate 5.
It is sufficient that the light diffraction structure 4 composed of the light diffraction structure layer 3 and the light reflection layer 2 is laminated on the lower surface of the protective layer 7.
The adhesive layer 8 may be added as needed.

The adhesive layer 8 need not be provided on the information recording label 20 depending on how the information recording label 20 is used. For example, the base material 1 and the lowermost layer of the information recording label
This is not necessary when they have thermal adhesiveness to each other, or they can be laminated while applying an adhesive to one or both of the lowermost layer of the base material 1 and the information recording label. However, it is troublesome to prepare and apply the adhesive every time the lamination is performed.
It is better to form

Each layer of the information recording label 20 is made of a transparent substrate 5
It can be manufactured by sequentially laminating the respective layers on the upper surface or the lower surface. On the upper surface of the transparent substrate 5, the rewritable layer 6 and, if necessary, each layer of the protective layer 7, and on the lower surface of the transparent substrate 5, the light diffraction structure layer 3, the light reflective layer 2, and the The paint or ink necessary for forming each layer of the adhesive layer 8 is sequentially applied and formed, and if necessary, heated and dried, irradiated with ionizing radiation, and the like, and then cured to be laminated. However, the light diffraction structure layer 3 is provided with irregularities using a mold after coating. The light-reflective layer 2 is laminated by a method such as vacuum evaporation or sputtering, depending on the material.

To laminate the information recording label 20 on the substrate 1, the information recording medium 20 cut into a predetermined shape on the substrate 1 is laminated with the light diffraction structure 4 or the adhesive layer 8. In some cases, this is performed by arranging the adhesive layer 8 so as to face the substrate 1 and applying heat and pressure. Thereafter, if necessary, when the heating press is performed again, the laminated layers are partially embedded in the base material 1 so that the laminated portion and the surrounding portion form the same plane.

When the rewritable layer 5 or the protective layer 7 of the information recording label 20 is involved, the protective layer 7 is adhered to another sheet-like substrate with a relatively weak adhesive force. It is convenient to laminate the base material 1 by punching out only the part with a predetermined shape at a predetermined pitch or the like. In this case, the sheet-like substrate preferably has mechanical strength, is hardly stretched by heating, and is smooth. Usually, polyethylene terephthalate (= PE
T) A resin film is often used, but other resin films, metal foils, papers and the like may be used. At the time of transfer, a release layer or the like may be formed on the sheet-like base material so that the information recording label 20 can be peeled off smoothly.

Although not described in the description of the information recording medium 10 and the information recording label 20, in each case, a corona treatment or a chemical treatment may be performed in order to improve or stabilize the adhesion between the respective layers. A primer layer may be interposed between the layers. The information recording medium 1 of the present invention basically has the above configuration, and is preferably manufactured using the information recording label 20. However, the information recording medium 1 may include other information recording means described above.

For example, in the case of a card, as a character and a picture,
(1) The name of the card issuer, the name of the card, or the name of the association if it is to be distributed to the member, such as the tint block, the character, and (2) the arrow to indicate the direction of insertion of the card into the reader / writer. Mark, and (3) general precautionary notes on use may be formed on the front surface or the back surface. Known information recording means include (4) a magnetic recording layer,
(5) an IC module, (6) a writable layer made of a writable material for the card holder to sign, (7)
An optical recording layer recordable by a laser beam, (8) an image formed by sublimation transfer or photo pasting, or an area where these can be formed. Depending on the use of the information recording medium, other information recording means may be provided.

The information recording medium 10 of the present invention can be used, for example, as a magnetic card, a contact-type or non-contact compatible IC card, an optical card (= optically recordable card), or an arbitrary composite card thereof. It can be used for pass tickets, boarding tickets, boarding passes, prepaid cards, admission tickets, play tickets, point cards, cash cards, credit cards, ID cards, employee ID cards, membership cards, etc. Widely available.

[0048]

EXAMPLES (Example 1) First, an information recording label was prepared as follows. As a transparent base material, a 25 μm-thick polyethylene terephthalate (= PET) resin film was used, and a reversible recording layer forming composition and a protective layer forming composition having the following compositions were used. A reversible recording layer having a thickness of 1 μm and a protective layer were formed. (Composition for forming reversible recording layer) 15 parts by mass of vinyl chloride / vinyl acetate copolymer resin 5 parts by mass of behenic acid 80 parts by mass of tetrahydrofuran (composition for forming protective layer) Cellulose acetate resin 5 Mass part ・ Methanol 25 mass parts ・ Methyl ethyl ketone 45 mass parts ・ Toluene 25 mass parts ・ Methylolated melamine resin 0.5 mass parts ・ Paratoluenesulfonic acid 0.05 mass parts

A composition for forming a hologram layer having the following composition was applied to the lower surface of the polyethylene terephthalate resin film having the reversible recording layer and the protective layer laminated on the upper surface by a gravure coating method to form a 2 μm thick hologram. A resin film was formed. (Hologram layer forming composition) ・ Acrylic resin 40 parts by mass ・ Melamine resin 10 parts by mass ・ Cyclohexanone 50 parts by mass ・ Methyl ethyl ketone 50 parts by mass ・ Aryl alkyl ketone 3 parts by mass

The hologram-forming resin film was embossed using a metal plate in which hologram interference fringes were formed in an uneven shape, and the unevenness of the hologram was imparted to form a hologram layer. Thereafter, aluminum was vapor-deposited on the resin surface having the irregularities to a thickness of 300 ° to form a light-reflective layer. Finally, a composition for forming a heat seal layer having the following composition was applied to the aluminum-deposited surface by a gravure coating method to form a heat seal layer having a thickness of 2 μm. (Composition for forming heat seal layer)-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

As described above, the protective layer / reversible recording layer / PE
An information recording label having a structure of T film / hologram layer / light reflective layer / heat seal layer was obtained. Note that the symbol “/” means that components before and after this symbol are stacked on each other.

The following were prepared as targets for lamination using the above information recording labels. Two sheets of white vinyl chloride resin sheet (= core sheet) having a thickness of 280 μm are stacked, and a transparent vinyl chloride resin sheet (= over sheet) having a thickness of 100 μm is stacked on and under each of them,
A total of four sheets were temporarily bonded to form a card base material having a thickness of 760 μm. On the surface of the obtained card base material,
The information recording label obtained above is placed so that the heat seal layer side faces the card base material, and 5 cm × 2
using a mold having a size of cm, temperature of the mold; 140 ° C., pressure;
Lamination was performed under the conditions of 20 kg / cm ² .

The protective layer / reversible recording layer / PET film / hologram layer / light reflection laminated on the card substrate to improve the adhesive strength between the respective sheets of the temporarily pasted card substrate. Temperature: 120 ° C. to embed the laminate comprising each layer of the heat-resistant layer / heat-sealing layer
As a result of hot pressing under the condition of a pressure of 20 kg / cm ² , a card having a surface of the protective layer flush with the surrounding card base material was obtained.

With respect to the reversible recording layer of the obtained card,
When printing was performed under the condition of 0.5 mJ / dot, the recorded state was good and the printed information was easily read. In this state, the hologram of the background could be visually recognized from the portion other than the color developed by printing. When the printed information was erased under the condition of 0.2 mJ / dot, it was completely erased, and there was no problem in the visibility of the lower layer hologram in the erased state.

Example 2 An information recording medium was prepared in the same manner as in Example 1 except that the light-reflective layer in the information recording label in Example 1 was formed by evaporating TiO ₂ to a thickness of 300 °. did. Hereinafter, in the same manner as in Example 1, lamination was performed on the card base material, and the evaluation was performed. Since the light-reflective layer was transparent, the only difference was that the base could be seen through. Similar results were obtained.

[0056]

According to the first aspect of the present invention, since the rewritable layer is located on the upper layer, the rewritable layer has better recording visibility than the conventional case where the rewritable layer is located on the lower layer. An information recording medium that has an advantage that damage and contamination of the light diffraction structure are extremely small because the light diffraction structure becomes a lower side and is under the transparent substrate, compared with the case where the light diffraction structure is conventionally exposed on the surface. Can be provided. According to the invention of claim 2, in addition to the effect of the invention of claim 1, since an adhesive layer is interposed between the base material and the light diffraction structure, each of them does not have heat fusion property. Also, it is possible to provide an information recording medium in which mutual adhesion is ensured. According to the invention of claim 3,
In addition to the effects of the invention of claim 1 or claim 2,
Since the protective layer is laminated on the rewritable layer, it is possible to provide an information recording medium which is less likely to be stained or damaged even if writing / erasing to the rewritable layer is repeated. According to the invention of claim 4, the rewritable layer is laminated on the upper surface of the transparent substrate, and the light diffraction structure is laminated on the lower surface. An information recording label suitable for manufacturing an information recording medium can be provided. According to the fifth aspect of the present invention, in addition to the effect of the fourth aspect of the present invention, the adhesive layer 8 is laminated on the surface of the information recording label facing the adherend side. It is possible to provide an information recording label which can be laminated by adhesiveness with an adhesive without coating. According to the invention of claim 6, in addition to the effect of the invention of claim 4 or 5, the information recording medium has a protective layer which is the uppermost layer of the information recording label, so that the information recording medium having excellent surface properties by lamination. Can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of an information recording medium according to an embodiment of the present invention.

FIG. 2 is a sectional view of an information recording medium according to another embodiment of the present invention.

FIG. 3 is a sectional view of an information recording label.

[Explanation of symbols]

 Reference Signs List 1 base material 2 light reflective layer 3 light diffraction structure layer 4 light diffraction structure 5 transparent base material 6 rewritable layer 7 protective layer 8 adhesive layer 10 information recording medium 20 information recording label

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B42D 15/10 501 G09F 9/30 370 G06K 19/10 B41M 5/18 B G09F 3/10 F 9/30 370 E 101A 5/26 102 G06K 19/00 R (72) Inventor Masayuki Ishikawa 1-1-1 Ichigaya-Kagacho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. 2C005 HA17 HB14 JA18 JB04 JB08 JC02 KA07 KA49 LA19 LB08 LB26 2H026 AA07 AA09 BB02 BB24 EE05 FF01 FF11 FF13 FF29 GG01 GG10 2H111 HA07 HA23 HA35 5B035 AA07 BA01 BA05 BB03 BB05 BB11 BC00 5C094 AA01 BA41 CA19 DA13ED

Claims (6)

[Claims] An information characterized in that a light diffraction structure, a transparent base material, and a rewritable layer comprising at least a light reflective layer and a light diffraction structure layer are laminated on a substrate in this order. recoding media. 2. The information recording medium according to claim 1, wherein an adhesive layer is interposed between the substrate and the light diffraction structure. 3. The information recording medium according to claim 1, wherein a protective layer is laminated on the rewritable layer. 4. A rewritable layer is laminated on an upper surface of a transparent substrate, and a light diffraction structure including a light diffraction structure layer and a light reflective layer is laminated on a lower surface of the transparent substrate. Information record label to be used. 5. The information recording label according to claim 4, wherein an adhesive layer is laminated on a lower surface of the light diffraction structure. 6. The information recording label according to claim 4, wherein a protective layer is laminated on an upper surface of the rewritable layer.