JP5256751B2 - Diffraction structure transfer foil and diffraction structure transfer medium - Google Patents

Description

  The present invention relates to a diffractive structure transfer foil having a function for easily detecting tampering.

  Conventionally, in order to prevent forgery of an article, the article itself has been made difficult to imitate, or with respect to distinguishing between genuine and counterfeit goods, an article that is difficult to imitate is genuine. It has been made to attach to goods as proof of. For example, for securities such as banknotes and stock certificates, printing technology, copiers, scanners, etc. were used by subjecting themselves to fine printing and watermarking, and coloring that makes color reproduction difficult. It has been difficult to forge by duplication.

  However, with the advancement of digital technology, it has now become possible to easily reproduce fine printing processes and color assignments that were difficult to counterfeit by color copying and scanners. For this reason, the printing process as a forgery prevention measure has been further refined, and simple copying and forgery are difficult. On the other hand, as a result of such high miniaturization, there is a problem that it is not easy to determine authenticity at a glance and determine the authenticity of an article.

  For this reason, attaching a diffractive structure in which a diffraction grating pattern, which is easy to determine and handle authenticity, to an article (an anti-counterfeit object) has been widely used as a forgery prevention means. In general, diffractive structures employed as such anti-counterfeiting means generally include a release layer having a releasability on a support, a diffraction structure forming layer having a diffraction grating pattern formed thereon, a reflective layer having a metallic luster, and an adhesive layer. Etc. are sequentially laminated to form a transfer foil (for example, see Patent Document 1).

  Although there are several manufacturing methods for forming the diffraction grating pattern in the diffractive structure, in this specification, only the manufacturing method of the relief type diffractive structure is described as an example, but the present invention is limited to this manufacturing method. Is not to be done.

The relief-type diffractive structure is formed by recording desired image information as a diffraction grating pattern having irregularities on a diffractive structure forming layer. When light is applied to the diffractive structure forming layer, the incident light causes interference by the diffraction grating, and the original image information is reproduced at a certain angle with respect to the incident light or an angular direction within a certain range. This relief type diffractive structure forming layer can be mass-produced by producing an original plate on which image information is recorded as a diffraction grating pattern and embossing a material suitable as the diffractive structure forming layer with this original plate. It is adopted for diffractive structures.
JP-A-61-190369 JP 2004-101647 A JP 2000-218908 A

  However, the relief type diffractive structure has a problem because it includes a reflective layer for observing diffracted light (see FIG. 1). After the diffraction structure portion 2 is transferred to a transfer medium (not shown) such as paper or film via the adhesive layer 17, the reflection layer 15 is irradiated with laser light, heat rays, electron beams, or the like. , The reflective layer, or all of the layers above the reflective layer can be removed. In that case, the relief type diffractive structure that has been deliberately tampered with removed appears to be an error product generated in the manufacturing process by visual observation. Therefore, this error product has a high value as a rare value. It is the fact that it is the object of trading.

  As a conventional anti-counterfeiting measure, a diffractive structure is disclosed in which a wavelength conversion layer for generating visible light by irradiation with excitation light of a specific wavelength is provided between the reflective layer 15 and the adhesive layer 17 ( For example, see Patent Document 2). However, for the act of intentionally falsifying the reflective layer using laser light or heat rays, the appearance does not change before and after the falsification. It was difficult to find falsification because the remaining wavelength conversion layer emits light even in the place where the light is removed and falsified.

  Further, a diffractive structure in which a release layer, a colored layer, a diffractive structure forming layer, a reflective thin film layer, and an adhesive layer are sequentially formed on a support is disclosed (for example, see Patent Document 3). The layer is a layer in which a coloring material is mixed with a resin in order to improve the design of an image expressed by a diffractive structure. In the coloring material such as a dye or pigment described, a laser beam or heat It is not possible to detect tampering of the reflective layer.

  This invention is made | formed in view of this condition, The subject is providing the diffraction structure which can detect the alteration of a reflection layer easily, and its transfer foil, maintaining the forgery prevention effect. In addition, the diffraction structure transfer foil has practically sufficient durability and chemical resistance. Furthermore, the diffractive structure transferred medium itself is a diffractive structure transferred medium transferred to a medium such as paper, film and plastic substrate.

In order to achieve the above-mentioned object in the present invention, the invention of claim 1 is provided on a support, at least a peeling protective layer, a light absorption discoloration layer containing a temperature indicating material , a diffraction structure forming layer, a reflective layer, and an adhesive layer Is a diffractive structure transfer foil characterized by laminating layers in this order.

  In this configuration, if the reflective layer is intentionally irradiated with laser light, heat rays, or electron beams to remove the reflective layer, the light absorbing material contained in the light absorption discoloration layer absorbs the irradiation energy. As a result of the temperature rise, the resin component including the light absorbing material is altered and discolored / colored, so that it can be easily detected visually that the falsification has occurred.

  By adopting a configuration in which a temperature indicating material is added, the coloring effect due to heat generation and heating is enhanced, or a completely different color is exhibited, so that detection becomes easier.

The invention according to claim 2 is the diffractive structure transfer foil, wherein the reflective layer is patterned, and the reflective layer is covered with a chemical-resistant protective layer patterned in the same shape.

  If it is this structure, since a reflective layer can be patterned to a desired shape, the freedom degree of an external appearance and a design will increase, and a durable diffraction structure will be obtained.

The invention of claim 3 is a diffractive structure transfer foil characterized in that it comprises an adhesion auxiliary layer or a printing layer.

With this configuration, in combination with the invention of claim 2 , a diffractive structure having sufficient resistance in a chemical immersion test, a heat test, etc. after being transferred to a medium such as paper or plastic can be obtained.

According to a fourth aspect of the present invention, there is provided a diffractive structure transfer medium characterized in that the diffractive structure transfer foil is bonded to the transfer medium and the supporting substrate is peeled off.

  For diffractive structure transfer media such as gift certificates, banknotes, confidential documents, etc., or cards and certificates transferred to plastic produced by transferring the diffractive structure of the present invention to paper, light or heat rays are used. Since it is possible to easily detect the tampering used, it is possible to intentionally manufacture an error product, and to prevent fraudulent acts that target a tampered product that is false as an error product. In addition, a diffractive structure transfer medium having practically sufficient durability and a high degree of freedom in appearance design can be obtained.

  Hereinafter, the best mode of the structure of the anti-counterfeit paper as an example of the diffraction structure transfer foil and the diffraction structure transfer medium according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 schematically shows a diffractive structure transfer foil 3 (hereinafter simply referred to as a transfer foil) showing the first and second examples of the present invention as a cross-sectional state taken along line AA in FIG. FIG. FIG. 2 shows the transfer foil 3 as viewed from the arrow side in FIG. The transfer foil 3 is obtained by laminating a diffractive structure 2 (hereinafter simply referred to as a transfer layer) on a support 1, and adheres an adhesive layer 17 to a transfer medium (not shown) such as paper or film. After fixing, the support 1 is peeled off and only the transfer layer 2 is transferred to the transfer medium. The transfer foil 3 has a color depending on a peeling protection layer 11 for protecting the transfer layer 2 from scratches caused by friction, various chemicals, etc., a light absorbing material that absorbs light such as laser light and heat rays, and converts the heat into heat. Light-absorbing discoloration layer 12 containing a temperature-indicating material that changes, a diffraction structure forming layer 13 that generates diffracted light by incident light from the side of the peeling protection layer 11, a reflective layer 15 that reflects diffracted light, and a medium to be transferred It has the adhesive layer 17 which has the function to adhere | attach. On one side of the diffractive structure forming layer 13, an embossed shape 14 as a diffraction grating pattern is provided by embossing, and a reflective layer 15 is in occlusal contact with the diffraction grating. This is the basic configuration of the diffractive structure according to the present invention.

  FIG. 2 is a plan view of the transfer foil 3 showing the first and second examples of the present invention, and shows a state in which the transfer layer 2 is viewed from the support 1 side in FIG. In the example of FIG. 2, the light absorption color changing layer 12 is formed in a numerical shape “10000”, and the reflective layer 15 is formed on the entire surface of the transfer layer 2. Further, the hexagonal star shape and the lower case letters of the alphabet indicate the diffracted light image by the embossed surface 14 of the diffractive structure forming layer 13.

  Next, FIG. 3 is a diagram schematically showing a transfer foil 5 showing a third example of the present invention as a cross-sectional state when cut along BB in FIG. The transfer layer 4 in the transfer foil 5 also includes a release protective layer 11, a light absorbing material that absorbs light such as laser light and heat rays and converts it into heat, and a light absorbing discoloration layer that includes a temperature indicating material that changes color depending on temperature. 12, a diffractive structure forming layer 13 that generates diffracted light by incident light from the peeling protection layer 11 side, an embossed surface 14 that is a diffractive structure, a reflective layer 15 that reflects diffracted light, and a reflective layer 15 are partially It has a chemical-resistant protective layer 16 necessary for providing, and an adhesive layer 17 for adhering to a transfer medium.

FIG. 4 is a plan view of the transfer foil 5 showing a third example of the present invention, and shows a case where the transfer layer 4 is viewed from the support 1 side in the cross-sectional view of FIG. In the example of FIG. 4, the reflective layer 15 having the same shape as the chemical-resistant protective layer 16 has a portion having a horizontally long shape at both ends and a small character shape of “Security”. A hexagonal star-shaped diffracted light image can be observed, and a diffracted light image of the same shape can be observed for the letters “Security”. On the other hand, since the diffracted light generated on the embossed surface 14 is not reflected at the other portions where the reflective layer 15 is not present, the observer cannot see the diffracted light image. Patterning of the reflective layer 15 is performed by etching the chemical-resistant protective layer 16 into a desired shape, and using this as a mask to remove the reflective layer in the opening. As a result, the anti-counterfeiting effect is further improved.

  Next, FIG. 5 shows a counterfeit produced by transferring the transfer layer 2 of the transfer foil 3 of the present invention shown in FIGS. 1 and 2 to paper as a transfer medium 6 and then peeling the support 1. FIG. 7 is a cross-sectional view schematically illustrating an example of a result of falsification of the prevention paper 7 by removing a part of the reflective layer 15, and corresponds to a CC section in FIG. 6. FIG. 6 is a plan view when FIG. 5 is observed from the side of the peeling protection layer 11. In the example of FIG. 6, after the transfer layer 2 of the transfer foil 3 according to the present invention is transferred to a gift certificate in a band shape. This shows an example of tampering to remove the reflective layer 15. It was easily confirmed that the reflective layer 15 was falsified because it was observed that the white light-absorbing discoloration layer 12 having the number shape of “10000” was colored black only in the irradiated portion. We were able to.

  On the other hand, FIG. 7 shows the forgery prevention produced by transferring the transfer layer 4 of the transfer foil 5 according to the present invention shown in FIGS. 3 and 4 onto the paper as the transfer medium 6 and peeling the support 1. FIG. 7 is a plan view showing a result of falsification that removes a part of the reflection layer 15 that is partially formed on the paper 8 (gift certificate), and FIG. 7 corresponds to the DD section of FIG. It is a part to do. When the removal portion 21 of the reflection layer was observed, a white light absorption discoloration layer 12 having a numeral shape of “10000”, and a discoloration portion 22 in which a part of the removed portion was changed to black was observed. This indicates that the reflective layer 15 was not removed by mistake during the manufacture of the transfer foil, but a part of the reflective layer 15 was removed after the transfer layer 4 was transferred to the gift certificate. This suggests that the paper is a forgery-preventing paper that can easily detect tampering.

  Hereinafter, the materials and forming methods of the layers constituting the anti-counterfeit paper which is an example of the diffraction structure transfer foil of the present invention and the diffraction structure transfer medium using the same will be described.

(Support)
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 processed antistatic treatment, mat processing, embossing, printing of a character and a pattern, laser marking etc. can also be used for these resin films.

(Peeling protection layer)
As the peeling protection layer 11, 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 the peeling protective layer 11 on the support 1 by a known coating method such as a gravure printing method or a micro gravure method.

(Light absorption discoloration layer)
As the light absorption discoloration layer 12, one obtained by adding a light absorbing material to a resin or one obtained by adding both a light absorbing material and a temperature indicating material to a resin 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, polyamideimide resin, urethane resin, epoxy resin, and the like. In addition, an infrared absorber or an ultraviolet absorber can be used as the light absorbing material, and the blending ratio of the light absorbing agent is set to 0. 0 parts by weight with respect to 100 parts by weight of the composition comprising the resin constituting the light absorbing discoloration layer 12. It is preferable to add 1 to 20 parts by weight, but it is not limited to this as long as the adhesion and durability are not affected. In addition, as a temperature indicating material used in combination with the resin and the light absorbing material, when the tampering is performed to remove the reflective layer 15 without changing the color at the temperature at which the transfer foil is processed or the environment temperature at which it is normally used. Therefore, it is desirable to use a temperature indicating material having a color change temperature of 200 ° C. or higher, such as a bismuth compound. These light absorbers and temperature indicating materials can be used alone or in combination of two or more. The light-absorbing discoloration layer 12 is formed on a part of the peeling protection layer 11 in any shape such as characters and images by a known coating method such as a gravure printing method or a micro gravure method.

(Diffraction structure forming layer)
The diffraction structure forming layer 13 can be a diffraction structure such as a relief type diffraction grating or a volume type diffraction grating, and is recorded as a diffraction grating by forming a fine uneven pattern 14 on the surface thereof.

  The relief type diffraction grating, for example, uses the two-beam interference method to irradiate the surface of the photosensitive resin with two coherent light beams to generate interference fringes on the surface of the photosensitive resin. Can be formed on the photosensitive resin in the form of irregularities. The interference fringes formed by the two-beam interferometry are also diffraction gratings, and any three-dimensional image can be recorded as a diffraction grating pattern 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.

  Regarding the method of recording an image pattern by the diffraction grating structure used in the present invention, in addition to the two-beam interference method, conventionally known holograms such as an image hologram, a Lippmann hologram, a rainbow hologram, and an integral hologram are used. It can be manufactured by a manufacturing method.

  In addition, the concave / convex pattern of the relief type diffraction grating can form a diffraction structure by irradiating the surface of the electron beam curable resin with an electron beam and exposing it to a striped pattern to be a diffraction grating. In this case, since the interference fringes can be controlled for each line, an arbitrary 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 pixels. 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 in a range from blue to green, several μm scale As a result, movement of polymer molecules is caused, and as a result, a relief due to 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 laminated on the support 1, and the fine concavo-convex pattern 14 is transferred to the surface of the resin layer, whereby the diffraction structure forming layer 13 can be obtained.

As the resin applied to the diffraction structure formation 13 by 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, in a thermoplastic resin, an acrylic resin, an epoxy resin, a cellulose resin, a vinyl resin, etc. are mentioned. 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 the like 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.

(Reflective layer)
The reflection layer 15 does not need to be provided in direct contact with the diffraction structure forming layer 13, but when the diffraction structure formation layer 13 is a relief type diffraction grating, the reflection layer 15 is provided in direct contact with the concavo-convex pattern 14. Need to be done. In this case, the light reflected by the reflective layer 15 is diffracted light.

  Moreover, as the reflective layer 15, 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, the reflective layer 15 can be formed into an image pattern or a character pattern having the same shape as the chemical resistant protective layer 16 by processing in the following manner.

  First, the first method is to form a reflective layer 15 uniformly on the entire surface, and provide a chemical resistant resin layer colored with a colorant on the reflective layer 15 as a chemical resistant protective layer 16 in an image pattern. In this method, the reflective layer 15 is formed by dissolving and removing the exposed reflective layer by applying an alkaline or acidic etching solution. In the present invention, the chemical-resistant protective layer is used as a protective layer for leaving the chemical-resistant protective layer as it is to provide chemical resistance.

  In the second method, a photosensitive resin layer is formed as a chemical-resistant protective layer 16 on the reflective layer 15 formed uniformly on the entire surface, exposed and developed into an image pattern, and then subjected to alkaline or acidic etching. This is a method of dissolving and removing the exposed reflective layer by applying a liquid.

  Note that the image pattern of the reflective layer 15 and the chemical-resistant protective layer 16 may be a random pattern having no clear meaning. However, recognizable information such as a pattern, a figure, a pattern, a character, a number, a symbol, etc. is given. Is also possible.

(Chemical-resistant protective layer)
As the chemical-resistant protective layer 17, it is desirable that the coating film does not change even when an etching method immersed in an aqueous sodium hydroxide solution is used. As a specific example of the etching method, the chemical-resistant protective layer 16 is formed on the reflective layer 15 formed uniformly on the entire surface, and the sodium hydroxide aqueous solution is kept at 40 to 50 ° C. to 1.5 N. The reflective layer 14 can be processed into an image pattern by using the solution as an etchant and immersing in this etchant for 5 to 30 seconds.
The chemical resistant protective layer 17 is preferably 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 acid and alkali, but also to protect the deformation of the reflective layer 15 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 colorant, etc. can be added up to 40 parts by weight with respect to 100 parts by weight of these resins. When added in excess of 40 parts 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 it dries on the plate, so that the printability deteriorates, and those additives in the coating liquid settle or aggregate during storage or coating. Sometimes.

(Adhesive layer)
Any adhesive layer 17 may be used as long as it adheres to the transfer medium by heat and pressure, and a known heat-sensitive adhesive material can be used.

(Other layers)
As other layers, in order to strengthen the adhesion between each layer, to provide an anchor layer, to print characters and designs, to partially improve concealment and visible light opacity A printing layer can be added, and these inks can also use well-known adhesion improvers, adhesives, and printing inks, respectively.

(Anti-counterfeit paper and anti-counterfeit media)
After the transfer foil according to the present invention is stacked on the transfer medium 6 and bonded by thermocompression bonding, the support 1 is peeled and removed, whereby the transfer layers 2 and 4 are transferred to produce anti-counterfeit papers 7 and 8. Can do. For the transfer medium 6, a desired material such as paper, plastic, or synthetic paper can be used.

  Next, the present invention will be described by way of examples.

Example 1
First, the transfer foil 3 as the first example will be described. As the support 1, a transparent polyethylene terephthalate (commonly known as PET) film having a thickness of 25 μm was used.

  On one side of this support 1, an ink comprising the following composition was applied and dried to form a release protective layer 11 having a thickness of 2 μm.

  Next, an ink composed of the following composition was applied to a part of the protective layer 11 in a numerical shape and dried to form a light absorption discoloration layer 12 having a thickness of 1.5 μm.

  Next, an ink comprising the following composition is applied and dried to form a layer having a thickness of 1 μm, and then a press plate for forming a diffraction grating is hot-pressed by a roll embossing method to generate a diffraction grating on the surface. An embossed shape 14 was formed to form a diffraction structure forming layer 13.

  In addition, an aluminum vapor deposition film was uniformly formed with a film thickness of 50 nm on the entire surface of the diffractive structure forming layer 13 by a vacuum vapor deposition method to form a reflective layer 15.

  Finally, ink composed of the following composition was applied and dried to form an adhesive layer 17 having a thickness of 3 μm, and the transfer foil 3 of the first example of the present invention was manufactured.

"Peeling protective layer ink composition"
Polyamideimide resin (Tg. 250 ° C.) 19.2 parts by weight Polyethylene powder 0.8 part by weight Dimethylacetamide 45.0 parts by weight Toluene 35.0 parts by weight “Light Absorption Discoloration Layer Ink Composition”
Urethane resin 20.0 parts by weight Infrared absorbing material (cupric-containing phosphate-based composition) 1.0 part by weight Thermosensitive material (bismuth compound) 2.5 parts by weight Methyl ethyl ketone 50.0 parts by weight Ethyl acetate 30.0 Weight part "Diffraction structure 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 “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 The support 1 is peeled and removed immediately after being thermally transferred to the paper medium 6 using a circular heat roll type transfer machine heated to a temperature of 120 ° C. The anti-counterfeit paper 7 was manufactured.

(Example 2)
Next, the transfer foil 5 as the third example will be described. As the support 1, a transparent polyethylene terephthalate (commonly known as PET) film having a thickness of 25 μm was used.

  On one side of this support 1, an ink comprising the following composition was applied and dried to form a release protective layer 11 having a thickness of 2 μm.

  Next, an ink composed of the following composition was applied to a part of the protective layer 11 in a numerical shape and dried to form a light absorption discoloration layer 12 having a thickness of 1.5 μm. In addition, since the reflective layer 15 is partially formed in the transfer foil 5, it is necessary to form the light absorption discoloration layer 12 so that the whole or a part of the light absorption discoloration layer 12 always overlaps with the reflection layer 15. In this embodiment, the light absorption layer The discoloration layer 12 has the shape of the number “10000” and is arranged so as to overlap the elliptical reflection layer 15 as shown in FIG.

  Next, an ink comprising the following composition is applied and dried to form a layer having a thickness of 1 μm, and then a press plate for forming a diffraction grating is hot-pressed by a roll embossing method to generate a diffraction grating on the surface. An embossed shape 14 was formed to form a diffractive structure forming layer 13.

  Next, an aluminum vapor deposition film is uniformly formed with a film thickness of 50 nm on the entire surface of the diffractive structure forming layer 13 by a vacuum vapor deposition method, and the chemical-resistant protective layer 16 having a thickness of 1 μm is further formed on the aluminum vapor deposition film. It formed so that the position might overlap with the light absorption discoloration layer 12. Then, it is immersed for 10 seconds in a bath containing 1.5N sodium hydroxide aqueous solution kept at 50 ° C., and the chemical-resistant protective layer 16 becomes a mask, and the aluminum deposited film is exposed without the chemical-resistant protective layer 16 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. Thus, the reflective layer 15 composed of an aluminum vapor deposition film in an independent image pattern, and the chemical-resistant protective layer 16 which is superimposed on the reflective layer 15 and has the same shape as the reflective layer 15 were formed.

  Finally, an ink composed of the following composition was applied and dried to form an adhesive layer 17 having a thickness of 3 μm, and the transfer foil 5 of the third example of the present invention was manufactured.

"Peeling protective layer ink composition"
Polyamideimide resin (Tg. 250 ° C.) 19.2 parts by weight Polyethylene powder 0.8 part by weight Dimethylacetamide 45.0 parts by weight Toluene 35.0 parts by weight “Light Absorption Discoloration Layer Ink Composition”
Urethane resin 20.0 parts by weight Infrared absorbing material (cupric-containing phosphate-based composition) 1.0 part by weight Thermosensitive material (bismuth compound) 2.5 parts by weight Methyl ethyl ketone 50.0 parts by weight Ethyl acetate 30.0 Weight part "Diffraction structure 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 Precipitating 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 “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 transfer foil 5 Is placed on a paper medium 6 on which a desired print such as a character or a pattern has been printed in advance, and the substrate 1 is immediately transferred to the medium 6 using a circular hot roll type transfer machine heated to a temperature of 120 ° C. The anti-counterfeit paper 8 was manufactured by peeling off.

  When the transfer layers 2 and 4 transferred in stripes on the anti-counterfeit papers 7 and 8 manufactured in this way are observed, different colors and images are generated by the diffracted light depending on the observation angle, and the reflection layer 15 is also generated. When the paper is not altered or tampered with, the numeral “10000” appears white, indicating that the paper has the same anti-counterfeit effect as before.

  Further, when a part of the reflection layer 15 in the transfer layers 2 and 4 of the anti-counterfeit papers 7 and 8 manufactured by the method according to the present invention was removed by laser light having an output of 2 W and a wavelength of 1064 nm, both were irradiated with laser light. The reflection layer of the portion (tampered portion 21) is removed, and only the portion irradiated with the laser light is discolored black in the light absorption discoloration layer 12, so that it is possible to easily determine the tampering. I understood.

Sectional drawing (AA cross section of FIG. 2) of the diffraction structure transfer foil which shows the 1st example which concerns on this invention. The top view of the diffraction structure transfer foil which shows the 1st example which concerns on this invention Sectional drawing of the diffraction structure transfer foil which shows the 3rd example which concerns on this invention (BB cross section of FIG. 4) Top view of diffraction structure transfer foil showing a third example of the present invention Sectional drawing which shows that a part of reflection layer of the forgery prevention paper produced using the diffraction structure transfer foil which shows the 1st example which concerns on this invention was removed by falsification (CC cross section of FIG. 6) The top view which shows having removed a part of reflection layer of the forgery prevention paper produced using the diffraction structure transfer foil which shows the 1st example which concerns on this invention by tampering Sectional drawing which shows that a part of reflection layer of the anti-counterfeit paper produced using the diffraction structure transfer foil which shows the 3rd example which concerns on this invention was removed by tampering (DD section of FIG. 8) The top view which shows having removed a part of reflection layer of the forgery prevention paper produced using the diffraction structure transfer foil which shows the 3rd example which concerns on this invention by tampering

Explanation of symbols

1 ··· Supports 2 and 4 ··· Diffraction structure (or simply transfer layer)
3, 5... Diffraction structure transfer foil (or simply transfer foil)
6 ... Media to be transferred 7, 8 ... Anti-counterfeit paper 10 ... Observation direction (arrow)
DESCRIPTION OF SYMBOLS 11 ... Detachment protective layer 12 ... Light absorption discoloration layer 13 ... Diffraction structure formation layer 14 ... Embossed shape part (concavo-convex part)
15 ····· Reflecting layer
16 ··· Chemical-resistant protective layer 17 ··· Adhesive layer 21 ··· Tampered portion (where the reflective layer has been removed illegally)
22 ··· Color change part (location changed by tampering)

Claims (4)

1. A diffractive structure transfer foil, wherein at least a peeling protective layer, a light absorption discoloration layer containing a temperature indicating material , a diffractive structure forming layer, a reflective layer, and an adhesive layer are laminated in this order on a support. The diffractive structure transfer foil according to claim 1, wherein the reflective layer is patterned, and the reflective layer is covered with a chemical-resistant protective layer patterned in the same shape. Diffraction structure transfer foil according to claim 1 or claim 2, characterized in that it comprises an adhesion auxiliary layer or printing layer. A diffraction structure transfer medium, wherein the diffraction structure transfer foil according to any one of claims 1 to 3 is adhered to a transfer medium, and the support is peeled off.