JPH08118857A - Preventing method for forgery and alteration of information recording medium, information recording medium designed so as to prevent forgery and alteration, and transfer sheet - Google Patents

Abstract

PURPOSE: To provide a means for very effectively preventing the forgery of an information recording medium and the alteration of information recorded thereon by providing a light-diffracting structure for preventing forgery on various information recording media of cards such as credit cards, cash cards, etc., of bank notes and of identification cards and important documents. CONSTITUTION: The side of a light-diffracting structure forming layer 4 of a transfer sheet 1 wherein at least the light-diffracting structure forming layer 4 is provided on one face of a base sheet 3 while a back surface slippery layer 2 is provided on the other face thereof is arranged to be opposed to an information-recorded face of an information recording medium. Thereupon, the light-diffracting structure forming layer 4 is transferred onto the information recording medium by heating the transfer sheet from the side of the back surface slippery layer 2 with the aid of a heating medium like a thermal head, whereby a light-diffracting structure is provided on the information recorded on the information recording medium in accordance with the shape and size of the information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tampering prevention method, a forgery / tampering prevention information recording medium, and a transfer sheet.

[0002]

2. Description of the Related Art Conventionally, information recording media such as credit cards, cash cards, etc., cash vouchers, identification cards, important documents, etc. prevent the forgery of these items. Various anti-counterfeiting means are provided for this purpose, and providing an optical diffraction structure such as a diffraction grating or a hologram on the information recording medium as described above is one of the many anti-counterfeiting means.

As described above, a light diffraction structure such as a diffraction grating or a hologram is widely used for the purpose of preventing forgery because it is difficult to duplicate not only the decorative property but also the decorative property. As means for providing the recording medium, for example, a release layer, a resin layer having a light diffractive structure formed thereon, and an adhesive layer as disclosed in JP-A-4-281489 are provided on a base sheet. It is possible to exemplify a means of using a transfer sheet that is sequentially laminated and transferring and forming a light diffraction structure on an information recording medium.

However, in recent years, the technique of manufacturing the light diffraction structure is not so difficult, and the duplication of the light diffraction structure can be performed more easily than ever before. For this reason, the anti-counterfeiting effect of the optical diffraction structure is fading, and it seems that in the near future, simply providing the optical diffraction structure on the information recording medium will not be sufficient to prevent the forgery. .

Therefore, as a result of diligent research conducted by the present applicant in view of the above points, in order to prevent forgery by providing an optical diffraction structure, it is extremely effective to forge an information recording medium and falsify information recorded therein. The inventors have found means that can be prevented and have completed the present invention.

[0006]

That is, the forgery / tampering prevention method for an information recording medium of the present invention is a forgery / tampering prevention method for preventing forgery or alteration of an information recording medium having various information recorded thereon. Then, a transfer sheet having at least a light-diffraction structure forming layer provided on one surface of the base sheet and a back surface slipping layer provided on the other surface is used to form the light-diffraction structure of the transfer sheet. By transferring the optical diffraction structure forming layer to the information recording medium by heating the layer side to the information recording surface of the information recording medium and heating with a heating medium capable of arbitrarily changing the heating site from the back sliding layer side ,
It is characterized in that an optical diffraction structure is provided on each piece of information recorded on the information recording medium according to the shape and size of the information.

Further, the information recording medium of the present invention, which is forged and falsified prevented, is an information recording medium in which various information is written, and at least the light diffraction structure forming layer is formed on one surface of the base material sheet. The backside slipping layer is provided on the other side of the transfer sheet. The light diffractive structure forming layer side of the transfer sheet is made to face the information recording surface and the heating portion is arbitrarily changed from the backside slipping layer side. By heating with a heating medium capable of transferring the above-mentioned optical diffraction structure forming layer, an optical diffraction structure is provided on each information recorded on the information recording medium according to the shape and size of the information. It is characterized by being

In the transfer sheet of the present invention, the back surface slipping layer is provided on one surface of the base material sheet, and the recording information transfer layers are alternately arranged on the other surface.
A transfer layer and a second transfer layer having a light diffraction structure forming layer are provided.

[0009]

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

In the information recording medium forgery / falsification preventing method of the present invention, at least the light diffraction structure forming layer 4 is provided on one surface of the base sheet 3, and the back surface slipping layer 2 is provided on the other surface. With the transfer sheet 1 as shown in FIG. 1 provided, the optical diffraction structure forming layer 4 side of the transfer sheet 1 is made to face the information recording surface of the information recording medium 9, and the heating portion is arbitrarily changed. A heat medium such as a thermal head capable of heating is used to heat the back surface slipping layer 2 side to transfer the light diffraction structure forming layer 4 to the information recording medium 9, and the face recorded on the information recording medium 9 as shown in FIG. Photo 1
By providing the light diffraction structure 14 on the information such as 0, the number display 11, the signature 12, and the red stamp 13 according to the shape and size of the information, it is attempted to prevent the information recording medium 9 from being forged or falsified. It is a thing.

Further, in providing the light diffractive structure 14 on the information recorded on the information recording medium 9 in the present invention, the pattern on which the light diffractive structure 14 is provided is not limited to that shown in FIG. For example, when the information is the signature 12, the light diffractive structure 14 may be provided on each character as shown in FIG. 3 (a), and further, as shown in FIG. 3 (b). As described above, the light diffraction structure 14 may be provided so as to form individual letters. 2 and 3, the illustration of the diffraction image by the light diffraction structure 14 is omitted.

On the other hand, the information recording medium 9 of the present invention, which is forgery / tamperproof, is forged / counterfeited by the above-mentioned method.
It is intended to prevent falsification, and is shown in FIG.
Shows an example of the information recording medium 9 of the present invention.

Here, the light diffraction structure in the present invention means a diffraction grating or a hologram, and interference fringes of the diffraction grating or the hologram are recorded in the light diffraction structure forming layer 4 transferred from the transfer sheet to the information recording medium. Has been done.

The diffraction fringes or hologram interference fringes recorded in the optical diffraction structure forming layer 4 are recorded as reliefs of surface irregularities (in the case of a hologram, interference fringes are recorded in this way). Is generally referred to as a "planar hologram"), and is three-dimensionally recorded in the thickness direction (for example, a hologram having interference fringes recorded in this way is referred to as a "volume hologram"). (Generally called), or that is recorded so that diffraction occurs due to a change in the amplitude of light due to a change in transmittance (in the case of a hologram, for example, interference fringes are recorded as (Generally referred to as “amplitude hologram”), and specific examples of the hologram as an optical diffraction structure include a Fresnel hologram and a Fraunhofer hologram. Grams, lensless Fourier transform hologram, a laser such as an image hologram reproducing holograms, Lippmann hologram, Denisyuk holograms, white light reproduction hologram such as a rainbow hologram,
Holographic stereograms utilizing these principles, multiplex holograms, color holograms, computer holograms, hologram displays, holographic diffraction gratings and the like can be mentioned.

Examples of the information recording medium in the present invention include cards such as credit cards and cash cards, cash vouchers, identification cards, important documents, etc., but these are merely examples. However, it includes all that may cause various inconveniences due to counterfeiting or falsification of the information recorded on it, and the information recorded on such an information recording medium is not the one described above. Also, various information including characters, symbols, figures, patterns, images, facial photographs, etc. can be mentioned.

In the present invention, a light diffractive structure 14 is provided on each piece of information recorded on the information recording medium 9 according to the shape and size of the information, and the light diffractive structure 14 covers the information. This is particularly important because it makes it difficult to copy or falsify the information, and can very effectively prevent forgery or falsification of the information recording medium 9.

That is, the information covered by the light diffractive structure 14 cannot be tampered with without modifying the light diffractive structure 14, and the information is recorded without damaging the light diffractive structure 14. Since it is difficult to peel off from the medium 9 or restore the damaged optical diffraction structure 14 to the original state, if an attempt is made to tamper with the information, the trace remains and it is easily known whether the information has been tampered with. It is extremely difficult to falsify the information written on the information recording medium 9, so that it is possible to prevent the information recording medium 9 from being forged or falsified.

The transfer sheet 1 used for providing the light diffractive structure 14 on the information recording medium 9 in the present invention.
As described above, the light-diffraction structure forming layer 4 is provided on one surface of the base sheet 3 and the base sheet 3
Although the back surface slipping layer 2 is provided on the other surface, it is preferable that the total thickness be 5 to 30 μm so as not to hinder the heat conduction from the heating medium during transfer.

In order to form the above-mentioned diffraction grating or hologram interference fringes on the light-diffraction structure forming layer 4 provided on the transfer sheet 1, it is possible to form by a conventionally known method. When recording the interference fringes of a hologram as a relief of surface irregularities, an original plate on which diffraction gratings and interference fringes are recorded in the form of irregularities is used as a press mold, and a resin sheet is placed on this original plate and a heating roll or the like is appropriately used. It suffices to heat and press the two with a means to copy the uneven pattern of the original plate, and in this way, the interference fringes of the diffraction grating or the hologram are recorded on the surface of the light diffraction structure forming layer 4 as a relief of the uneven surface. Is preferable in terms of mass productivity and cost.

The material of the light diffraction structure forming layer 4 forming such a light diffraction structure is a thermoplastic resin such as polyvinyl chloride, acryl (eg, MMA), polystyrene, polycarbonate, unsaturated polyester, melamine. ,
Cures thermosetting resins such as epoxy, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, triazine acrylate The above compounds or a mixture of the above-mentioned thermoplastic resin and thermosetting resin can be used, and besides these, a thermoformable substance having a radically polymerizable unsaturated group can also be used. In addition, in these materials, when the light diffraction structure forming layer 4 is transferred from the transfer sheet 1 and the light diffraction structure 14 is provided on the information recording medium 9, the information recorded on the information recording medium 9 is completely hidden. It must be transparent enough not to be destroyed.

Further, when recording interference fringes of a diffraction grating or a hologram as reliefs of unevenness on the surface of the optical diffraction structure forming layer 4, a transparent thin film layer 5 for improving diffraction efficiency is formed on the relief surface 6. The transparent thin film layer 5 is not particularly limited as long as it is light transmissive so that the diffraction efficiency can be increased.
1) a transparent continuous thin film having a refractive index larger than that of the light diffraction structure forming layer 4,
₂ S ₃ , TiO ₂ , ZnS, SiO, TiO, SiO _2, etc., transparent in the visible region, transparent in the infrared or ultraviolet region, 2) having a refractive index higher than that of the light diffraction structure forming layer 4. A large transparent ferroelectric material, 3) a transparent continuous thin film having a refractive index smaller than that of the light diffraction structure forming layer 4, 4) a reflective metal thin film having a thickness of 200 Å or less, 5) a resin having a different refractive index from the light diffraction structure forming layer 4, 6) A layered product obtained by appropriately combining the materials of the above 1) to 5) can be cited.

In the above 1) to 6), the thickness of 4) is 200 Å, but the thicknesses of 1) to 3), 5) and 6) are in the transparent region of the material forming the thin film layer 5. It suffices to have it, and generally, it is 500 to 2000Å. Also, the above 1) to
When the thin film layer 5 is formed by 4), it can be formed by a general thin film forming means such as a vacuum vapor deposition method, a sputtering method, a reactive sputtering method, an ion plating method, and an electroplating method. To form
The thin film layer 5 can be formed by a general coating method. Further, when the thin film layer 5 is formed by the above 6), the thin film layer 5 can be formed by appropriately combining the various means and methods described above.

As the base material sheet 3 of the transfer sheet 1, one having a certain degree of rigidity and heat resistance of about 3 to 25 μm is used. Specifically, various processed papers such as condenser paper or polyester, Examples of the synthetic resin sheet include polystyrene, polypropylene, polysulfone, polyphenylene sulfide, polyethylene terephthalate, polyethylene naphthalate, 1,4-polycyclohexylenedimethyl terephthalate, aramid, polycarbonate, polyvinyl alcohol, and cellophane. Polyethylene terephthalate is particularly preferable in terms of properties, heat resistance, toughness and the like.

On the side of the base sheet 3 on which the light-diffraction structure forming layer 4 is provided, a peeling layer 7 having a thickness of about 0.1 to 1.0 μm is provided, if necessary, in order to improve peeling property and foil cutting property. The thickness can be set, but the material is appropriately selected according to the material of the base sheet 3, and polymethacrylate ester, polyvinyl chloride, cellulose, silicone, waxes containing hydrocarbon as a main component, polystyrene, chloride Examples thereof include rubber, casein, various interfacial lubricants, metal oxides, etc. These may be used alone or in combination of two or more kinds. If the base material sheet 3 itself has releasability, it is not necessary to provide the release layer 7, and in this case, the optical diffraction structure forming layer 4 after transfer is protected at the position where the release layer 7 is provided. A surface protective layer can also be provided.

Further, in order to easily break these layers into an arbitrary shape, fine powder such as micro silica may be added in an amount of 10% or less. Of course, since transparency is required, the particle size is limited to 1 μm or less.

Further, the heat-sensitive adhesive layer 8 may be provided as necessary in consideration of the adhesiveness to the material to be transferred, that is, the information recording medium 9, and as the resin constituting the heat-sensitive adhesive layer 8, , Polyacrylic acid ester, polyvinyl chloride, chlorinated polypropylene, polyester, polyurethane, rosin or rosin-modified maleic acid, vinyl chloride-vinyl acetate copolymer and the like.

Fine powder such as microsilica may be added to the adhesive layer in order to easily break it into an arbitrary shape, and 1 to 200% may be added depending on the purpose. Further, fine particles having a size of 1 μm or less are favorable because they have little influence on the reflective thin film layer, such as generating irregularities in the layer during transfer.

In the back surface slip layer 2 of the transfer sheet 1, a phosphoric acid ester-based surfactant and / or a fixed lubricant as a liquid lubricant for imparting lubricity to the back surface slip layer 2. Particles having a Mohs hardness of less than 3 are contained, and as the above-mentioned phosphate ester-based surfactant, a saturated or unsaturated higher alcohol having 6 to 20 carbon atoms, preferably 12 to 18 carbon atoms (for example, cetyl alcohol). , Stearyl alcohol, oleyl alcohol, etc.) long-chain alkyl phosphates such as monophosphates or diphosphates, phosphates such as polyoxyalkylene alkyl ethers or polyoxyalkylene alkylaryl ethers, or higher alcohols as described above, Alkylpheno having at least 1 to 2 alkyl groups having 8 to 12 carbon atoms (For example, nonylphenol, dodecylphenol, etc.) or nonionic or anionic phosphorus such as alkylnaphthol or alkylene oxide adduct of diphenylphenol (usually, the number of moles added is 1 to 8) such as monophosphate ester salt or diphosphate ester salt. The acid ester surfactant is used, and as the particles having a Mohs hardness of less than 3, inorganic particles such as talc, kaolin, sekiboku, salt stone, gypsum, and blues stone, acrylic resin, Teflon resin, silicone resin, lauroyl resin, and phenol are used. Synthetic resin particles made of resin, cross-linked polyacetal resin or the like are used.

The particles having a Mohs hardness of less than 3 preferably have a particle size of about 0.01 to 10 μm,
Those in the range of 30 to 400% of the thickness of the back surface slipping layer 2 are preferable. Furthermore, the closer the particle shape is to the spherical shape, the more excellent the lubricity can be imparted to the back surface slipping layer 2. When using natural inorganic particles, the content of impurities is 5
If it is less than%, it can be used in the present invention without any trouble.

If the back surface slippery layer 2 can be provided on the substrate sheet 3 with sufficient film strength, the above-mentioned phosphate ester type surfactant and / or Mohs hardness is 3
Although it may be composed of only particles of less than 5 parts, the back surface slipping layer 2 is prepared by blending a phosphoric acid ester surfactant or particles having a Mohs hardness of less than 3 with a resin binder in order to obtain sufficient film strength. Is preferably configured. The resin binder used in this case may be any of a thermoplastic resin, a thermosetting resin, or an ionizing radiation curable resin, but from the viewpoint of flexibility and head followability, the thermoplastic resin or a crosslinked product thereof. Is preferred.

Examples of such thermoplastic resin include polyester resin, polyacrylic ester resin, polyvinyl acetate resin, styrene acrylate resin, polyurethane resin, polyolefin resin, polystyrene resin, polyvinyl chloride resin. Resin, polyether-based resin, polyamide-based resin, polycarbonate-based resin, polyacrylate-based resin, polyacrylamide-based resin, polyvinyl chloride-based resin and the like can be used, but in the present invention, reactive hydroxyl groups such as polyvinyl butyral and polyvinyl acetal. It is preferable to use a resin having

When a phosphate ester type surfactant and / or particles having a Mohs hardness of less than 3 are blended with the above resin binder, the phosphate ester type surfactant contains 100 parts by weight of the resin binder including an alkaline substance described later. 5 to 500 parts by weight is preferable, and particles having a Mohs hardness of less than 3 are preferably added in a ratio of 5 to 40 parts by weight with respect to 100 parts by weight of the resin binder. When the amount of the phosphate ester-based surfactant or the particles having a Mohs hardness of less than 3 is small with respect to the resin binder, sufficient lubricity cannot be obtained in the back surface slipping layer 2, and when the amount is too large. Reduces the flexibility and coating strength of the back surface slipping layer 2.

Further, the resin binder has heat resistance of the back surface slipping layer 2, adhesion to the base sheet 3, and back surface slipping layer 2
In order to improve the coatability when forming a coating, it is preferable to add polyisocyanate as a crosslinking agent,
As such a polyisocyanate, any of those conventionally known for synthesizing paints, adhesives, polyurethanes and the like may be used, and examples thereof include "Takenate" manufactured by Takeda Pharmaceutical Co., Ltd. and "Dainippon Ink Chemical Co., Ltd.
"Burnock", "Nippon Polyurethane Co., Ltd .; Coronate", "Asahi Kasei Co., Ltd .; Duranate",
A commercially available product such as "Bayer Co., Ltd .; Dismodule" can be used.

When polyisocyanate is used as a crosslinking agent for the resin binder, the polyisocyanate is added in a proportion of 5 to 200 parts by weight with respect to 100 parts by weight of the resin binder, and the NCO / OH ratio is 0.8 to 2.0. If the amount of polyisocyanate added at this time is small, the crosslinking density will be low and the heat resistance will be insufficient, and if the amount of polyisocyanate added is too large, a coating formed. It becomes difficult to control the shrinkage of the film, the curing time becomes long, and the unreacted NCO groups remaining in the back surface slipping layer 2 react with the moisture in the air. Inconvenience will occur.

It is sufficient that the back surface slipping layer 2 of the transfer sheet 1 contains both or one of the above-described phosphate ester type surfactant and particles having a Mohs hardness of less than 3. When a phosphate ester type interfacial lubricant is contained in the back surface slip layer 2, when a heat is applied to the back surface slip layer 2 from a heating medium such as a thermal head, a phosphate ester surface active agent or Neutralize the acid radicals generated from the decomposition products,
It is preferable to add an alkaline substance so as to prevent the heating medium from being corroded.

Examples of such an alkaline substance include alkaline inorganic compounds such as hydrotalcite, aluminum hydroxide, aluminum silicate, magnesium silicate, magnesium carbonate, alumina hydroxide / magnesium aluminum glycinate, magnesium hydroxide and magnesium oxide, Methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, tripropylamine, butylamine, dibutylamine, tributylamine, pentylamine, dipentylamine, tripentylamine, trihexylamine, trioctylamine ,
Decylamine, dodecylamine, didodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, eicosylamine, docosylamine,
Examples of amines include ethanolamine, diethanolamine, triethanolamine, propanolamine, dipropanolamine, isopropanolamine, N-methyl-nonylamine, N-methyl-decylamine, and N-ethyl-palmitylamine. These may be used alone or in combination. In addition, when an alkaline inorganic compound is added, the Mohs hardness is 3
It is preferred to add less than less than. The amine is preferably non-volatile at room temperature and has a boiling point of 200 ° C. or higher.

The above-mentioned alkaline substance is preferably added in a proportion of about 0.1 to 10 mol per mol of the phosphate ester-based interfacial lubricant, and the amount of the alkaline substance added to the phosphate ester-based interfacial lubricant is. If the amount is too small, the acid radicals generated from the phosphate ester type surfactant or its decomposition product cannot be completely neutralized, and even if the amount added is increased more than necessary, the effect obtained cannot be improved.

Furthermore, in addition to the phosphate ester type surfactant and / or particles having a Mohs hardness of less than 3, the back surface slippery layer 2 includes wax, silicone oil, higher fatty acid amide, ester and phosphate ester type interface. If necessary, a lubricant such as a surfactant other than the activator, an antistatic agent such as a quaternary ammonium salt, a phosphoric acid ester, or the like can be added.

From these, 0.3 mj / dot
Furthermore, even if an applied energy of 0.8 mj / dot or more is applied, a desired transfer suitability can be obtained. In particular, the light diffractive structure cannot be satisfactorily transferred at a low energy (0.1 to 0.3 mj / dot) like a thermal transfer ribbon due to the film strength and the thickness of the transferred portion, so that the back surface slipperiness is improved. The layer is required to have higher heat resistance and heat sliding property. In addition, the light diffraction structure forming layer,
When it is made of a curable resin or is formed of a hard thin film such as an inorganic thin film, the bleeding component from the back surface slipping layer tends to remain attached to the cured film,
If the amount of the adhering component increases, interfacial peeling may occur, and the phenomenon of peeling may occur at the interface during printing or after printing. Therefore, in that case, it is desirable to use a solid lubricant or to increase the ratio of the solid lubricant to form a back surface slipping layer having a low adhesive property.

Such a back surface slip layer 2 is prepared by appropriately selecting the above-mentioned composition components constituting the back surface slip layer 2 and dissolving or dispersing it in a suitable solvent such as acetone, methyl ethyl ketone, toluene or xylene. The coating liquid can be formed by coating with a gravure coater, a roll coater, a wire bar, or the like.
5.0 g / m ^{2 on a} solids basis so that the hardness is about 2H
Below, it is preferable to form it to a thickness of preferably 0.1 to 1.0 g / m ² . When isocyanate is added as a cross-linking agent for the resin binder, unreacted isocyanate groups often remain, so it is preferable to perform sufficient aging treatment after coating and forming the back surface slipping layer 2. .

Further, since the transfer layer has a multi-layer structure and the total thickness is large, in order to increase the resolution of the light diffraction structure,
It is necessary to prevent heat diffusion in the surface direction on the back slipping layer. For that purpose, the thermal conductivity of the back surface slipping layer is 1.0 × 1.
0 ^-4 kcal / ms. ℃ or less, preferably 0.2 × 10
^-4 kcal / ms. It must be below ℃.

In providing the optical diffraction structure 14 on the information recording medium 9 in the present invention, the back slipping layer 2 as described above is the surface of the base sheet 3 opposite to the side on which the optical diffraction structure forming layer 4 is provided. That is, by using the transfer sheet 1 provided on the surface that comes into contact with the heating medium at the time of transfer, when the optical diffraction structure forming layer 4 is transferred to the information recording medium 9, air may enter and transfer to the transfer layer. A heating medium, such as a thermal head, which moves while being strongly pressed against the transfer sheet 1 so that the heat conduction is not insufficient, moves smoothly with respect to the transfer sheet 1 and causes no sticking phenomenon to occur in the optical diffraction structure forming layer 4. Good transfer can be performed, and when the contact surface with the heating medium is scraped to generate dust, this may burn with the heat of the heating medium and damage the heating medium. That there is no such debris occurs. Therefore, if such a transfer sheet 1 is used, the light diffractive structure 14 can be formed into an arbitrary pattern by a heating medium such as a thermal head capable of freely changing a heat generating portion according to a desired transfer pattern without any inconvenience. Can be provided and the effect of the present invention can be achieved.

That is, in order to transfer and form an optical diffraction structure on a material to be transferred using the transfer sheet proposed in Japanese Patent Laid-Open No. 4-281489 as described above on the information recording medium 9 as the material to be transferred, Conventionally, heat transfer by hot stamping has been generally performed, but transfer by hot stamping is limited to a fixed transfer pattern, and in order to change the transfer pattern of the optical diffraction structure, hot stamping is required each time. Since heat transfer by hot stamping is suitable when a large number of optical diffraction structures are transferred and formed in the same pattern because of the problem that the mold must be replaced, the optical diffraction structure has its purpose and application. It is unsuitable for individual transfer formation with various different patterns according to the above, and the optical diffraction structure of the transfer sheet is used as it is. When heat transfer with a heating medium such as a thermal head is performed from the back surface that is not provided, a sticking phenomenon occurs and the transfer sheet becomes inoperable, or in extreme cases, the transfer sheet is broken from that part. It is possible to solve the problem that the conventional technique has and to provide the light diffractive structure 14 in an arbitrary pattern according to individual information.

Further, the present invention can be applied to a product having the same shape but many sizes such as a manufacturer's symbol mark without any problem. Moreover, if a transparent thin film is used,
Even if the information is transferred onto the base material on which the information is already recorded, the information can be seen, and the designability and security are further increased.

Furthermore, in order to prevent the information recording medium 9 from being forged or tampered more effectively, the information recording medium 9 on which the information is recorded is subjected to a method of preventing forgery or tampering. In order to prevent the information already written from being tampered with, it is preferable to write the information on the information recording medium 9 and at the same time to provide the light diffraction structure 14 on the information recording medium 9 so that the information is written on the information recording medium 9. In addition to the description, as a transfer sheet on which the light diffraction structure 14 can be provided, the present applicant has provided the invention in addition to the forgery / tampering prevention method of the information recording medium and the information recording medium in which the forgery / tampering prevention is achieved. A transfer sheet to be obtained is also provided.

In the transfer sheet 1'of the present invention, as shown in FIG. 4, the back surface slip layer 2 is provided on one surface of the base material sheet 3, and the other surface is alternately arranged at appropriate intervals. A first transfer layer 15 having the recorded information transfer layer and a second transfer layer 16 having the light diffraction structure forming layer 4 are provided. The back surface slipping layer 2 and the light diffraction structure forming layer 4 are as described above.

The recording information transfer layer of the first transfer layer 15 is
It is provided to record various information on the information recording medium 9. Specifically, it is a sublimation transfer material capable of forming a face photograph or the like, a wax-based transfer material of a melting type, a magnetic material,
Optical recording materials, thermal recording materials, thin film recording materials, and various other recording materials can be used. Of course, it may be a hologram material. In addition, the contents of information written by transferring the recording information transfer layer are various contents such as a facial photograph, fingerprint, seal, other trademark, one-dimensional bar code, two-dimensional bar code, special pattern, magnetic bar code, etc. Can be However, since the second transfer layer is transferred onto the information layer after transfer, it is necessary to impart heat resistance and pressure resistance to the recorded information transfer layer so that the previously transferred information layer does not collapse at this time.

When the transfer sheet 1'of the present invention having such a structure is used, various information is written on the information recording medium 9 with the same heating medium, and the second information is alternately placed on the information.
The light diffractive structure forming layer 4 of the transfer layer 16 can be transferred to provide the light diffractive structure 14, and there is no risk of falsification of information before the light diffractive structure 14 covers the information.

Next, the present invention will be described in more detail with reference to specific examples.

[Example 1] A polyethylene terephthalate sheet having a thickness of 12 µm was used as a substrate sheet, and one surface of the sheet was coated with a backside slip layer by a coating solution having the following composition so that the thickness after drying was 1 µm. Formed.

[Backside slipping layer] ・ Polyvinyl butyral (S-REC BX-1) 8 parts ・ Polyisocyanate curing agent (Bernock D750) 18 parts ・ Phosphate ester (Prysurf A208S) 5 parts ・ Talc 1.5 parts ・ Methyl ethyl ketone (a) ) + Toluene (b) (a: b = 1: 1) 130 parts

On the other surface of the substrate sheet, a protective layer (1 μm) and a light-diffraction structure forming layer (3 μm) having the following composition were applied so that the thickness after drying would be a value in parentheses (). After sequentially forming by coating, the light-diffraction structure forming layer was formed as a relief hologram, and then a metal thin film layer was formed on the light-diffraction structure forming layer with TiO _x to a film thickness of 500 Å.

[Protective layer] -Cellulose acetate resin 5 parts-Methanol 25 parts-Methyl ethyl ketone 45 parts-Toluene 25 parts-Methylolated melamine resin 5 parts-Particulate microsilica (particle size 0.1 μm) 3 parts-Paratoluene sulfonic acid 0.05 part [Light diffraction structure forming layer] -Acrylic resin 40 parts-Melamine resin 10 parts-Cyclohexanone 50 parts-Methyl ethyl ketone 50 parts

Next, a heat-sensitive adhesive having the following composition was formed on the metal thin film layer so as to have a thickness of 3 μm after being dried to obtain a transfer sheet.

[Heat-sensitive adhesive layer] -Vinyl chloride-vinyl acetate copolymer 30 parts-Acrylic resin 10 parts-Particulate microsilica (particle size 0.1 μm) 10 parts

By using the obtained transfer sheet, by detecting the position of each character of the signature information and transferring the light diffraction structure so as to cover only the character portion, the forgery prevention property can be improved. did it.

Example 2 A transfer sheet was obtained in the same manner as in Example 1 except that the back surface slip layer was formed by coating with a coating solution having the following composition.

[Backside slipping layer] ・ Polyvinyl butyral (S-REC BX-1) 8 parts ・ Polyisocyanate curing agent (Bernock D750) 18 parts ・ Micro silica 5 parts ・ talc 1.5 parts ・ Methyl ethyl ketone (a) + toluene (b) (A: b = 1: 1) 130 copies

Using the obtained transfer sheet, a product having improved anti-counterfeiting property and designing property is issued by transferring the light diffraction structure on the face photograph in a trademark shape of the publisher by a thermal printer. We were able to.

[0060]

As described above, according to the present invention, a light diffraction structure is provided on each piece of information recorded on an information recording medium according to the shape and size of the information, and the light diffraction structure is used. Since the information is covered, duplication or tampering of the information is made difficult, and forgery or tampering of the information recording medium can be very effectively prevented.

In the present invention, when a light diffractive structure is provided on the information recording medium, the back surface slipping layer is provided on the surface of the base sheet opposite to the side on which the light diffractive structure forming layer is provided. By using a sheet, the light diffractive structure can be provided in an arbitrary pattern by a heating medium such as a thermal head that can freely change the heat generation site according to a desired transfer pattern without causing any inconvenience. The invention can be put into effect.

Further, when the transfer sheet of the present invention is used, various information is written on the information recording medium with the same heating medium, and the optical diffraction structure forming layer of the second transfer layer is alternately placed on the information. The light diffractive structure can be provided by transfer, and there is no risk that the information will be tampered with before the information is covered with the light diffractive structure.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of a transfer sheet used in the present invention.

FIG. 2 is a schematic plan view showing an example of an information recording medium protected from forgery / falsification of the present invention.

FIG. 3 is an explanatory diagram showing an example of a pattern in which an optical diffraction structure is provided on information recorded on an information recording medium in the present invention.

FIG. 4 is a vertical sectional view showing an example of the transfer sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 and 1'transfer sheet 2 back surface slipping layer 3 base material sheet 4 optical diffraction structure forming layer 9 information recording medium 15 first transfer layer 16 second transfer layer

Claims (5)

[Claims] 1. A forgery / falsification preventing method for preventing counterfeiting or falsification of an information recording medium on which various information is recorded, wherein at least a light diffraction structure forming layer is provided on one surface of a base material sheet. And a back surface slipping layer is provided on the other surface, and the optical diffraction structure forming layer side of the transfer sheet is made to face the information recording surface of the information recording medium and the back surface slipping layer side is formed. The shape of the information is recorded on the individual information recorded on the information recording medium by heating the information on the information recording medium by heating with a heating medium whose heating portion can be arbitrarily changed. A method for preventing forgery / falsification of an information recording medium, which comprises providing a light diffraction structure according to the size. 2. The forgery of the information recording medium according to claim 1, wherein the back surface slipping layer is composed of a resin having a reactive hydroxyl group and polyisocyanate, and a liquid lubricant and / or a solid lubricant is added thereto.・ Falsification prevention method. 3. An information recording medium on which various information is recorded, wherein at least a light-diffraction structure forming layer is provided on one surface of a base sheet, and a back surface slipping layer is provided on the other surface. The optical diffraction structure forming layer side of the transfer sheet provided with is opposed to the information recording surface, and the above optical diffraction structure forming layer is heated by a heating medium capable of arbitrarily changing the heating site from the back sliding layer side. Information that has been counterfeited or tampered with by being transferred, and an optical diffraction structure is provided on each piece of information recorded on the information recording medium according to the shape and size of the information. recoding media. 4. The counterfeiting / tampering prevention according to claim 1, wherein the back surface slipping layer comprises a resin having a reactive hydroxyl group and polyisocyanate, and a liquid lubricant and / or a solid lubricant is added thereto. The designed information recording medium. 5. A back surface slipping layer is provided on one surface of a substrate sheet, and first transfer layers having recording information transfer layers alternately arranged on the other surface, and a light diffraction structure. A transfer sheet having a second transfer layer having a forming layer.