JPH1081056A - Duplication preventing medium and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a duplication preventing medium which has an effect for preventing forgery by a color copying machine and a method for making the medium. SOLUTION: A latent pattern such as an alarm mark is formed on a duplication preventing medium by two or more kinds of light reflection parts A, B, C... which are different in reflectance, and the latent pattern is made evident by a duplicate by a color copying machine. In a method for making the latent pattern, backing layers 12-1, 12-2, 12-3... which are different in surface roughness are formed on a backing 11 according to the latent pattern, and a thin metal film layer 13 is formed on it by the deposition of metal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copy protection medium having a function of discriminating a copy which has been forged or falsified by using a copying machine, and a method for producing the same.

[0002]

2. Description of the Related Art Banknotes, gift certificates, stock certificates, receivables, etc., such as banknotes, gift certificates, stock certificates, bonds, etc., which should have been subjected to advanced counterfeiting measures in recent years due to technological advances in copying machines such as color copiers. , Admission tickets, invitation tickets, commuter passes, and copies of copy-prevention media such as ID cards have come to market and have become a social problem. As a method of suppressing forgery using these copying machines, it has been conventionally known to form a part of information on a copy prevention medium using silver ink made of aluminum powder or the like. Even if the copy prevention medium using the silver ink is forged by a copying machine such as a color copier, the silver color of the glossy silver ink is not reproduced in the copy. Therefore, by looking at the silver color of the silver ink,
Since it is possible to determine whether a copy is a forged copy using a copying machine, silver ink has an effect of preventing forgery. Similarly, a hologram or a diffraction structure of a diffraction grating cannot be reproduced by a copying machine, and is provided on a part of a copy protection medium. Diffraction structures such as holograms and diffraction gratings can change the diffraction light dynamically by changing the observation direction and illumination direction. The authenticity of the copy prevention medium can be determined. Further, in Japanese Patent Application Laid-Open No. 7-309062, two types of halftone dots formed at different screen rulings having different pitches and having the same density are adjacently formed in a pattern so that they cannot be visually discriminated. It has been proposed to provide for copy protection media. When this copy protection medium is copied by a copying machine such as a color copying machine, the low resolution of the copying machine causes
The density balance of the different types of halftone dots has collapsed, and patterns have become apparent.

[0003]

The silver ink is obtained by mixing a flat metal powder made of aluminum or the like with a transparent vehicle, and has a variation in the direction of the flat metal powder. Therefore, from a macro perspective, the reflective surface of the silver ink is a rough surface. On the other hand, a color copier irradiates light from a light source at an angle of 45 degrees with respect to the normal to the surface of the copy object, and a light receiving unit installed at a direction of 0 degrees with respect to the normal to the surface. The scattered light from the surface is received, and the information of the copy object is reproduced according to the received light intensity.
Therefore, the reflection surface of the silver ink scatters and reflects light from the light source of the color copier, and makes a part of the reflected light incident on the light receiving portion of the color copier. Based on the intensity of this incident light, the color copier replaces the silver ink portion of the copy with
The reproduction is reproduced in a light grayish hue without gloss.
However, such a change in which the silver color with a weak shine of silver ink is reproduced in light gray in a copy is lacking in its own impact, so some people do not notice this change and copy the copy. May be mistaken for a genuine copy-prevention medium, and with such a change, there is a problem that counterfeiting by a copying machine cannot be suppressed. Also, when a hologram or a diffraction grating is provided in a part of the copy protection medium, the reproduced image of the hologram or the diffraction grating in the direction of 0 degree by the illuminating light incident from the direction of 45 degrees due to the structure of the color copier described above. Is reproduced on a copy. By the way, in the work of discriminating a copy in a short time at the time of congestion or the work of discriminating a copy in darkness,
A dynamic change in diffracted light due to the diffractive structure cannot be sufficiently confirmed, and there is a problem that a copy is mistaken for a real copy prevention medium. Furthermore, the method proposed in Japanese Patent Application Laid-Open No. 7-309062 relies on the resolution of the copying machine, so that the anti-counterfeiting effect is reduced as the performance of the copying machine, such as the resolution and reproducibility, is improved. There is a problem that is expected. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide a copy prevention medium and a method for preparing the same, which can easily perform the authenticity discrimination work only by visual observation.

[0004]

In order to solve the above-mentioned problems, a copy-protecting medium according to the present invention comprises a first light reflecting portion comprising a first metal thin film layer and a first underlayer, and a second light reflecting portion. A copy-protection medium having a second light reflecting portion composed of a metal thin film layer and a second underlayer, wherein the first underlayer and the second underlayer are different, and the first metal thin layer is Is different from the surface roughness of the second metal thin film layer, so that the reflectance of the first light reflecting portion and the second light reflecting portion can be different.
In addition, if the first metal thin film layer and the second metal thin film layer are made of the same material, the step of forming the metal thin film layer can be performed once, and the first light reflecting portion of the copy prevention medium can be used. The difference between the second light reflection portion and the second light reflection portion is difficult to determine visually.
The fine particles are not contained in the first underlayer, the fine particles are contained in the second underlayer, or the content of the fine particles contained in the first underlayer per predetermined area and the second lower layer per predetermined area are reduced. The content of the fine particles contained in the formation layer is different or the average particle size of the fine particles contained in the first underlayer per a predetermined area, and the average particle size of the fine particles contained in the second underlayer per a predetermined area Or the thickness of the first underlayer and the second
If the thickness of the underlayer is different, the surface roughness of the first metal thin film layer and the surface roughness of the second metal thin film layer can be easily changed. If a latent pattern is formed by the first light reflecting portion and the second light reflecting portion provided adjacent to each other, the reproduction state of the first light reflecting portion and the second light reflecting portion in the copy , A latent pattern appears.
If a camouflage pattern is formed on the first light reflecting portion and the second light reflecting portion, the difference in reflectance between the first light reflecting portion and the second light reflecting portion in the copy preventing medium is determined by camouflage. can do. A first light reflecting portion and a second light reflecting portion;
The individual information may be formed on the light reflection part of. Further, a method for producing a copy prevention medium according to the present invention is a method for producing a copy prevention medium having a first light reflection portion and a second light reflection portion, wherein a step of preparing a base material, To
A step of forming a first underlayer, and a second step in which the presence or absence or content of fine particles per predetermined area or the average particle size of the fine particles, or the film thickness is different from that of the first underlayer on the substrate. Forming an underlayer, forming a metal thin film layer on the first underlayer and the second underlayer, and using the metal thin film layer on the first underlayer as a first light reflecting portion. And the step of using the metal thin film layer on the second underlayer as the second light reflecting portion, so that the surface roughness of the first metal thin film layer and the surface of the second metal thin film layer can be easily adjusted. Roughness can be different.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram for explaining the principle of a copy protection medium according to the present invention. Generally, in a copying machine, as shown in FIG. 1, light is radiated from a light source at an angle of 45 degrees with respect to the normal to the surface of the object to be copied, and the light is reflected and scattered on the surface of the object to be copied. Among the lights, there is adopted a method in which light reflected at an angle of 0 degrees with respect to the normal is received by a light receiving unit provided in that direction, the received light intensity is read, and the received light intensity is reproduced. In the present application, all angles are angles with respect to a normal line.
In addition, many copy-preventing media, which are to be copied, are multi-color printed. In a color copier, for each component of the three primary colors, the reflected light from the surface of the copy received at the light receiving unit is received. The received light intensity is measured, and the density gradation and color tone of the copy are reproduced according to the received light intensity. FIG. 1A is a diagram showing a case in which general white paper is used as a copy object. The illumination light is reflected and scattered on the surface of the copy object, and only the light reflected in the angle direction of 0 degrees reaches the light receiving unit, and the light receiving intensity is measured. Based on the received light intensity, the density gradation and color tone of the copy are reproduced on the copy. For general white paper,
The distribution of the reflected scattered light is substantially uniform, and the reflectance in the 0-degree angle direction is larger than that of silver ink or metallic luster described later, and is reproduced white in a copy by a copying machine. On the other hand, FIG. 1B is a diagram showing a case where a metallic glossy surface such as a mirror surface is used as a copy object. The illuminating light emitted at an angle of 45 degrees is specularly reflected at an angle of -45 degrees on a metallic glossy surface. do not do. Therefore, the metallic glossy surface is reproduced black on the copy by the copying machine. FIG. 1C is a diagram showing a case where the printing surface using silver ink is a copy object. The printing surface with silver ink,
The distribution of the reflected scattered light is more deviated in the regular reflection direction than general white paper, and exhibits an intermediate characteristic between general white paper and a metallic glossy surface. It is an intermediate value. Therefore, the printed surface of the silver ink is reproduced by the copier in a light gray color with no shine on the copy. The shine of the metallic glossy surface or the printing surface by silver ink is such that part of the light emitted from various angles is specularly reflected on the metallic glossy surface or the surface of the metal powder of the silver ink, and this reflected light is Because it comes into my eyes. By the way, a copier such as a color copier cannot receive regular reflection light and cannot reproduce a regular reflection surface due to its structure, and therefore cannot reproduce these glossy surfaces. Here, the ratio of the reflected light in the 0-degree angle direction of the copy to the illumination light from the light source provided in the 45-degree angle direction of the color copier, that is, the 45-degree irradiation and the 0-degree reflectance (Hereinafter, referred to as “reflectance 45-0”) can be expressed by the following equation. Reflectivity 45-0 = 0 reflected light amount at 0 degree / irradiated light amount at 45 degree × 100

The reflectance 45-0 of the light reflecting portion formed on the surface of the copy and the visual sensation, the reflection density and the visual sensation of the light reflection portion reproduced on the copy by the copying machine, and the Table 1 shows the results of examining the evaluation of the difference from the copy.

[Table 1] The light reflecting portion of the object to be copied as the sample for the above measurement is an aluminum-deposited surface, and by controlling the surface roughness of the substrate on which aluminum is deposited, light reflecting portions having different reflectivities of 45-0 are obtained. Was. The measurement of the reflectance 45-0 of the light reflection portion of the copy was performed using a visual filter with a Macbeth print contrast meter "PCM-2". Hereinafter, all values of the reflectance 45-0 are measured values by this apparatus. The reflection density of the light reflection portion reproduced in the copy was measured by a Macbeth reflection densitometer RD-918S (visual filter). This reflection densitometer irradiates illumination light from an angle direction of 45 degrees, receives a light amount reflected in an angle direction of 0 degrees, and performs reflection density conversion. Further, the column of visual sensation visually expresses the light reflection portion in the copy, and the reproduced light reflection portion in the copy, and the column of evaluation includes the light reflection portion of the copy and the copy. The light reflection portion reproduced in step (1) was shown to ten humans, and at a glance, it was confirmed whether or not a copy could be discriminated, and the number of discriminated persons was described. From Table 1, if the light reflecting portion of the copy is reproduced in black or dark gray with no shine in the copy, the difference becomes obvious, so that anyone can see the difference and copy the copy. Even a person who is not familiar with the object notices the abnormality of black or dark gray reproduced in the copy, so that the light reflecting portion has a function of authenticity determination. However, in the case where the object to be copied has only a single light reflecting portion, when copying with a copying machine such as a color copying machine, if the copy density is adjusted based on the reproduction color of the light reflecting portion in the copy. For example, in some cases, the light reflecting portion is reproduced in gray, and a person who does not know the copy cannot clearly determine whether or not the copy has been copied. Therefore, in the present invention, by providing two or more types of light reflecting portions having different reflectances on the copy preventing medium, it is difficult to forge by adjusting the copy density and to reproduce the two or more types of light reflecting portions in the copy. Depending on the state, it can be clearly judged visually that the copy is a copy.

FIG. 2 is a plan view showing a copy protection medium according to the present invention. Hereinafter, for the sake of easy understanding, the “first light reflecting portion” has a reflectivity of 45−− more than the “second light reflecting portion”.
Description will be made assuming that 0 is small. As shown in FIG. 2A, the copy protection medium 1 includes an individual information display area K and a latent pattern area S. Individual information display area K
For example, if it is a bank note, it consists of characters such as amount, serial number, name of factory, etc., and figures such as a person image, Bank of Japan seal, Ayamon, etc. Individual information 4 unique to the medium itself is provided by appropriate means such as printing or printing. In the latent pattern region S, two types of light reflecting portions having different reflectivities 45-0, that is, a first light reflecting portion A and a second light reflecting portion B are provided adjacent to each other. A latent pattern 3 is formed by the boundary between the light reflecting portions A and B. Latent pattern 3
May be appropriately selected from warning characters or marks such as "copy", "fake", and "invalid". The light reflecting portions A and B
Is such that the difference between the light reflecting portions A and B in the copy protection medium is visually overlooked, and the difference between the light reflecting portions A and B is 2 so that the difference can be reproduced in a copy by a copying machine such as a color copier. Preferably in the range of 10 to 10 percent,
A range of 3 to 5% is desirable from the balance between the two. Here, the difference between the reflectances 45-0 of the light reflecting portions A and B is
If it exceeds 10%, it is a genuine copy protection medium 1.
However, since the latent pattern 3 that must be difficult to see becomes apparent and can be easily identified by visual inspection, the copy prevention medium may be mistaken for a copy. Further, if the difference between the reflectances 45-0 of the light reflecting portions A and B is less than 2%, even a copy copied by a color copier becomes apparent due to the difference in reflectance between the two light reflecting portions. In some cases, the latent pattern 3 that should be performed does not become apparent, and the copied matter cannot be easily recognized. Further, in order to make the latent pattern 3 of the copy preventing medium 1 more difficult to recognize, the camouflage pattern 5 composed of fine characters, patterns, wavy lines, etc.
Is formed by printing.

FIG. 2B is a view showing a copy 2 obtained by copying the copy protection medium 1 shown in FIG. 2A by a copying machine such as a color copying machine. The individual information display area K ′ of the copy 2 is reproduced almost in the same manner as the individual information display area K of the copy protection medium 1. On the other hand, in the reproduction area S 'of the latent pattern area of the copy 2 corresponding to the latent pattern area S of the copy protection medium 1, as shown in FIG. 2B, the reproduction area A' of the first light reflection portion A. Due to the difference in the reproduction state of the reproduction area B ′ of the second light reflection portion B, the latent pattern 3 that was difficult to see on the copy prevention medium 1 becomes apparent in the copy 2 and easily becomes a check pattern 3 ′. You will be able to see it visually. The manifestation of this latent pattern 3
Unlike a delicate change in density or color tone of a specific portion of the copy protection medium 1, a pattern that is difficult to see on the copy protection medium 1 appears in a copy, and therefore has an impact. Therefore,
Even if a person who is not familiar with the copy protection medium 1 can see the abnormality just by looking at the copy, the function of judging the copy by this manifestation has a great effect.

Further, as described above, a metallic glossy surface such as an aluminum vapor-deposited surface is reproduced as light gray in a copy when the reflectance 45-0 exceeds 30% and becomes 40 to 50%. The function of determining a copy is reduced. However, by having two types of light reflecting portions as in the copy prevention medium of the present invention, even if the reflectance 45-0 exceeds 30%, the copy does not have a thin fog on the reproduced light reflecting portion. Is generated, but the reproduction areas of the two light reflecting portions having different densities are visible in the state. When the reflectance 45-0 of the light reflection portion exceeds 30%, the light reflection portion becomes slightly glossy, and unnaturalness when the entire copy protection medium is viewed is reduced.

Here, the location of the copy protection medium 1 where the latent pattern 3 is provided is not limited to the example of FIG. 2A, and may be any position on the copy protection medium 1. It is preferable to provide the forged copy in a place where the copy is easily noticeable using a copying machine. Further, the latent pattern display area S and the individual information display area K do not need to be partitioned as shown in FIG. 2A, and may overlap as appropriate, and the individual information display 4 is placed on the light reflecting portions A and B. May be provided.

Next, a method for producing a copy protection medium according to the present invention will be described. Generally, the reflectance 45 of the metal thin film layer
It is known that −0 changes depending on the surface roughness of a layer (underlayer) forming a thin film. Therefore, by controlling the surface roughness of the underlayer, it is possible to form two or more types of light reflecting portions having different reflectivities 45-0.

FIG. 3 is a schematic sectional view for explaining the latent pattern area S of the copy protection medium 1 according to the present invention.
In the embodiment shown in FIG. 3A, a smooth (small surface roughness) base layer 12-1 is provided on a rough (large surface roughness) base material 11-2, so that the surface roughness is small. Are formed, and the exposed portion of the substrate 11-2 is formed as a second underlayer,
The underlayer 12-1 is a first underlayer. By forming the metal thin film layer 13 on the first underlayer and the second underlayer by a vacuum deposition method or the like, two types of light reflecting portions A and B having different reflectances 45-0, that is, A first light reflecting portion and a second light reflecting portion are obtained. The base material 11-2 can be used as long as it has good adhesion to metal and has a rough surface. For example, a plastic sheet such as a rough polyethylene terephthalate sheet containing fine particles such as a pigment can be used.
The underlayer 12-1 may be any as long as it can fill the rough surface of the substrate 11-2 and smooth the rough surface. For example, the underlayer 12-1 is made of a synthetic polyester resin or the like that does not contain fine particles such as pigments. Resin can be used and is formed to a thickness enough to fill the rough surface of the substrate 11-2, for example, a thickness of about 0.1 to 20 μm. As the metal thin film layer 13, a material that reflects metal, for example, a metal such as aluminum can be used, a uniform thin film is formed, and a thickness that provides a metallic luster is provided.
For example, it is formed with a thickness of 200 to 1000 angstroms. The metal thin film layer 13 can be formed by a thin film forming means such as a vacuum evaporation method and a sputtering method. Instead of a simple metal such as aluminum, a transparent metal compound having a high refractive index such as zinc sulfide may be used as the metal thin film layer 13. A metal compound having a high refractive index reflects a part of incident light in a specular reflection direction due to a difference in refractive index at an interface, so that a copy of a portion where a metal compound is formed is compared with a portion where no metal compound is formed. It is reproduced with darkness. A metal compound having a high refractive index does not have a metallic luster in a copy protection medium like a metal simple substance, and the naturalness as a copy protection medium increases.

The embodiment shown in FIG. 3B is similar to the embodiment shown in FIG.
Contrary to the embodiment, by providing a rough base layer 12-2 on a smooth base material 11-1, two types of surfaces having different surface roughnesses are formed, and the base material 11-1 is exposed. The portion is a first underlayer, and the underlayer 12-2 is a second underlayer. By forming a metal thin film layer 13 on the first and second underlayers by performing metal deposition, two types of light reflecting portions A and B having different reflectivities 45-0, that is, A first light reflecting portion and a second light reflecting portion are obtained. The substrate 11-1 can be used as long as it has good adhesion to metal and has a smooth surface. For example, a plastic sheet of a smooth polyethylene terephthalate sheet containing no fine particles such as pigments can be used. The underlayer 12-2 only needs to be capable of roughening the surface of the base material 11-1, and includes, for example, inorganic pigments such as silicon dioxide, calcium carbonate, and titanium oxide, metal soaps,
Also, a mixture of fine particles such as plastic powder such as polyethylene powder and a synthetic resin such as a polyester resin can be used, and a thickness such that the surface of the base material 11-1 can be roughened, for example, 0.1 to It is formed to a thickness of about 10 μm.

Although the embodiment shown in FIGS. 3A and 3B can be applied to a case where the base material is a material having good adhesion to metal, for example, it has a very rough surface such as high quality paper and has a vacuum degree. However, the following embodiments can be applied to a base material that does not rise and does not have good adhesion to the metal deposition layer. In the embodiment shown in FIG. 3C, two types of surfaces having different surface roughnesses are formed by providing a smooth underlayer 12-1 and a rough underlayer 12-2 on the base material 11. , Smooth underlayer 12
-1 is the first underlayer, and the rough underlayer 12-2 is the second underlayer. By forming a metal thin film layer 13 on the first and second underlayers by performing metal deposition, two types of light reflecting portions A and B having different reflectivities 45-0, that is, A first light reflecting portion and a second light reflecting portion are obtained.
As the base material 11, the above-mentioned high quality paper or the like can be used. The underlayer 12-1 can be the same as that of the embodiment of FIG.
The same one as in the embodiment of (b) can be used.

In the embodiment shown in FIG. 3D, an underlayer 12-1 is formed on the entire surface of the substrate 11, and an underlayer 11-2 is formed on a part of the underlayer 12-1. . As the base material 11, the base material 11-2 of the embodiment of FIG.
Both of the substrates 11-1 of the embodiment (b) can be used. As the underlayer 12-1, the underlayer 12-2, and the metal thin film layer 13, those described above can be used. The embodiment of FIG.
3 (d) is required, whereas in the embodiment of FIG. 3 (d), such printing is required. And can be easily created.

The embodiment shown in FIG. 3E is similar to the embodiment shown in FIG.
In this embodiment, the number of underlayers is increased by one to provide three types of underlayers. As the underlayer 12-3, the underlayer 1
It is possible to use materials that can be used in 2-2. At that time, by changing the particle size of fine particles and the content per unit area,
Different surface roughness can be achieved.

In the embodiment shown in FIG. 3F, two underlayers 12-1 and 12- having different film thicknesses are formed on a rough substrate 11.
2, two types of surfaces having different surface roughnesses are formed, and the thick underlayer is the first underlayer 12-1, and the thin underlayer is the second underlayer 12-2. And By forming the metal thin film layer 13 on the first underlayer 12-1 and the second underlayer 12-2 by a vacuum deposition method or the like, two types of light reflecting portions having different reflectances 45-0 are provided. A and B, that is, a first light reflecting portion and a second light reflecting portion are obtained. Base 11, first underlayer 12-1, second underlayer 12-2,
And, as the metal thin film layer 13, FIG.
The same as in the embodiment can be used.

FIG. 4 is a sectional view showing the completed copy protection medium. The copy prevention medium 1 has an anchor layer 14 of a synthetic resin such as a polyester resin on the same two types of light reflection portions as in the embodiment of FIG.
It is provided with a thickness of 0.1 to 5 μm. A camouflage pattern printing layer 15 is provided on the anchor layer 14.
Is printed by a printing method such as offset printing or silk printing.
Further, an individual information print layer 16 is provided by printing, printing, or the like. Finally, a protective layer 17 made of a polyester resin, an acrylic resin, or the like is provided. In addition, as the protective layer 17, a transparent plastic film may be laminated, or a colored layer in which a dye or a pigment is mixed in a polyester resin or an acrylic resin may be provided.

(Example 1) Center line average roughness (hereinafter referred to as Ra)
The transparent polyester-based resin containing no fine particles with a thickness of 1 μm was partially applied to a substrate made of a white polyethylene terephthalate sheet having a thickness of 0.26 μm and a thickness of 188 μm by silk screen printing, and the “COP
An underlayer having a character pattern of "Y" was formed. Ra of base layer
Was 0.20 μm. Next, aluminum is vacuum-deposited to a thickness of 500 angstroms on the base material and the base layer to provide a metal thin film layer. The layer was used as a second light reflecting portion. Ra of the first light reflection portion was 0.20 μm, and reflectance 45-0 was 18%. Further, Ra of the second light reflection portion was 0.26 μm, and the reflectance 45-0 was 14%. In the copy prevention medium thus created, the latent pattern “COP” consisting of the boundary between the first light reflecting portion and the second light reflecting portion is used.
Y "was difficult to determine visually. When this copy protection medium was copied using a color copier (CLC500, manufactured by Canon), the latent pattern “C
The letters "OPY" became apparent, and it could be easily identified as a copy.

(Embodiment 2) Ra is 0.05 μm, thickness is 1
An ink obtained by mixing 5 parts by weight of microsilica as fine particles with respect to 100 parts by weight of a vinyl chloride-vinyl acetate copolymer-based resin by gravure printing on a substrate made of a transparent polyethylene terephthalate sheet having a thickness of 88 μm.
To form a base layer of a character pattern of "COPY". Ra of the underlayer was 0.10 μm. Next, on the base material and the underlayer, 5
A metal thin film layer was provided by vacuum evaporation to a thickness of 00 Å, and the metal thin film layer on the base material was used as a first light reflecting portion, and the metal thin film layer on the base was used as a second light reflecting portion. Ra of the first light reflecting portion was 0.05 μm, and Ra of the second light reflecting portion was 0.10 μm. Further, a polyester resin was printed at a thickness of 1 μm on the metal thin film layer by gravure printing to form an anchor layer. A camouflage pattern printing layer was formed on the anchor layer by gravure printing using an ink containing a blue dye. The individual information display was performed by gravure printing to form an individual information print layer. The reflectance of the first light reflecting portion 45−
0 was 6%, and the reflectance 45-0 of the second light reflecting portion was 10%. In the copy prevention medium thus prepared, the first light reflection portion and the second light reflection portion are further increased by the camouflage pattern printing layer.
Latent pattern “COP” consisting of the boundary line with the light reflection part
Y "was difficult to determine visually. When this copy protection medium was copied using a color copier (CLC500, manufactured by Canon), the latent pattern “C
The letters "OPY" became apparent, and it could be easily identified as a copy.

(Example 3) A transparent polyester resin containing no fine particles was partially applied to a base material made of high-quality paper at a thickness of 20 μm to form a first character pattern “COPY”.
Was formed. Next, as a background of the character pattern of “COPY”, an ink obtained by mixing 10 parts by weight of calcium stearate as fine particles with respect to 100 parts by weight of a polyester-based resin was subjected to hair removal printing at a thickness of 1 μm.
Was formed. Ra of the first underlayer is 0.30
μm, and Ra of the second underlayer was 0.37 μm. Next, aluminum is vacuum-deposited on the first underlayer and the second underlayer to a thickness of 500 angstroms to provide a metal thin film layer. The reflection portion, the metal thin film layer on the second underlayer
Light reflection part. Ra of the first light reflecting portion is 0.30
μm, and Ra of the second light reflecting portion is 0.37
μm. The reflectance 45-0 of the first light reflecting portion is 2
0%, and the reflectance of the second light reflecting portion is 4%.
5-0 was 24 percent. In the copy prevention medium thus created, the latent pattern “COPY” composed of the boundary between the first light reflecting portion and the second light reflecting portion.
Was difficult to determine visually. When this copy protection medium was copied using a color copier (CLC500, manufactured by Canon), the latent pattern “COP
The letter "Y" became apparent, and it could be easily identified as a copy.

(Example 4) A transparent polyester resin containing no fine particles was applied to the entire surface of a base material made of high-quality paper in a thickness of 20 µm to form a first underlayer. Next, a white acrylic resin obtained by mixing 10 parts by weight of micro silica as fine particles with respect to 100 parts by weight of the vinyl chloride-vinyl acetate copolymer-based resin was printed in a character pattern of "COPY" with a thickness of 1 [mu] m. Was formed. Ra of the first underlayer was 0.24 μm, and Ra of the second underlayer was 0.29 μm. Next, aluminum is vacuum-deposited on the first underlayer and the second underlayer to a thickness of 500 angstroms to provide a metal thin film layer. The reflecting portion and the metal thin film layer on the second underlayer were used as a second light reflecting portion. Ra of the first light reflecting portion was 0.24 μm, and Ra of the second light reflecting portion was 0.29 μm. The reflectance 45-0 of the first light reflecting portion is 15%, and
The reflectance 45-0 of the second light reflecting portion was 19%. In the copy protection medium thus created,
The latent pattern “COPY” composed of the boundary between the first light reflecting portion and the second light reflecting portion was difficult to visually discriminate. When the copy preventing medium was copied with a color copying machine (CLC500, manufactured by Canon), the character "COPY" as a latent pattern became apparent, and it could be easily identified as a copy.

(Example 5) A transparent polyester resin containing no fine particles was partially applied with a thickness of 10 µm to a base material made of high-quality paper to form a first underlayer. Next, a vinyl chloride-vinyl acetate copolymer resin 1 was added to the remaining part.
A second underlayer is formed by printing an ink obtained by mixing 5 parts by weight of microsilica (average particle size: 2 μm) as fine particles with a thickness of 1 μm with respect to 00 parts by weight to form a second underlayer. White acrylic resin mixed with 10 parts by weight of microsilica (average particle size: 5 μm) as fine particles with respect to 100 parts by weight of the acrylic resin was lint-printed to a thickness of 1 μm to form a third underlayer. Ra of first underlayer
Is 0.22 μm, and Ra of the second underlayer is 0.2 μm.
25 μm, and Ra of the third underlayer is 0.30 μm
Met. Next, the first underlayer, the second underlayer, and the third
Aluminum is vacuum-deposited to a thickness of 500 angstroms on the underlayer, a metal thin film layer is provided, and the metal thin film layer on the first underlayer is formed into a first light reflecting portion and a metal on the second underlayer. The thin film layer was used as a second light reflecting portion, and the metal thin film layer on the third underlayer was used as a third light reflecting portion. Ra of the first light reflecting portion
Is 0.22 μm, and Ra of the second light reflection part is 0.2 μm.
25 μm, and Ra of the second light reflecting portion is 0.30 μm.
m. The reflectance 45-0 of the first light reflecting portion is 12
%, And the reflectance of the second light reflecting portion is 45-0.
Was 14%, and the reflectance 45-0 of the second light reflecting portion was 18%. In the copy prevention medium thus produced, the first light reflecting portion, the second light reflecting portion, and the third light reflecting portion were difficult to visually discriminate. When this copy protection medium was copied using a color copying machine (CLC500, manufactured by Canon Inc.), each light reflection portion became apparent, and it was easy to identify a copy.

(Embodiment 6) Ra is 0.23 μm, thickness is 1
On a substrate made of a 88 μm white polyethylene terephthalate sheet, 5 μm of a vinyl chloride-vinyl acetate copolymer-based resin containing no fine particles was printed by silk screen printing.
And a first underlayer was formed in the character pattern portion of "COPY". Then, "COP
The second underlayer was formed by forming the same material as the first underlayer to a thickness of 1 μm on the background portion of the character pattern “Y”. Ra of the first underlayer is 0.11 μm,
Ra of the second underlayer was 0.18 μm. next,
Aluminum is vacuum-deposited on both underlayers to a thickness of 500 angstroms to provide a metal thin film layer, and the metal thin film layer on the first underlayer is used as the first light reflecting portion and the metal on the second underlayer. The thin film layer was a metal thin film layer as a second light reflecting portion. Ra of the first light reflecting portion is 0.11 μm and the reflectance is 4
5-0 was 7 percent. Further, Ra of the second light reflecting portion is 0.18 μm, and the reflectance 45-0 is
13 percent. In the copy prevention medium thus created, the latent pattern “COPY” formed by the boundary between the first light reflecting portion and the second light reflecting portion was difficult to visually discriminate. When the copy preventing medium was copied with a color copying machine (CLC500, manufactured by Canon), the character "COPY" as a latent pattern became apparent, and it could be easily identified as a copy.

[0025]

According to the copy protection medium of the present invention, since the surface roughness of the first metal thin film layer is different from the surface roughness of the second metal thin film layer, the first light reflecting portion and the second light reflecting portion are different. Since the reflectivity of the first light reflecting portion and the second light reflecting portion in the copy is different, a difference in the reflectance between the first light reflecting portion and the second light reflecting portion occurs in the copy, making it difficult to forge by adjusting the density of the copying machine. In addition, it is possible to clearly determine visually that the copy is a copy, and it is possible to suppress forgery of the copy protection medium by the copying machine and to prevent use of the copy. In addition, if the first metal thin film layer and the second metal thin film layer are made of the same material, the step of forming the metal thin film layer can be performed once, and the first light reflecting portion of the copy prevention medium can be used. It is difficult to visually discriminate the difference between the copy protection medium and the second light reflection portion, and the difference between the genuine copy protection medium and the copy forged by the copying machine becomes clear. The fine particles are not contained in the first underlayer, the fine particles are contained in the second underlayer, or the content of the fine particles contained in the first underlayer per predetermined area and the second lower layer per predetermined area are reduced. The content of the fine particles contained in the formation layer may be different, or the average particle size of the fine particles contained in the first underlayer per predetermined area may be different from the second particle per predetermined area.
The average particle size of the fine particles contained in the underlayer of
If the thickness of the first underlayer is different from the thickness of the second underlayer, the surface roughness of the first metal thin film layer can easily be made different from the surface roughness of the second metal thin film layer. Can, so,
The reflectance of the first light reflecting portion may be different from the reflectance of the second light reflecting portion. If the latent pattern is formed, the latent pattern appears due to the difference in the reproduction state between the first light reflecting portion and the second light reflecting portion in the copy, and therefore, a person who does not know the genuine copy prevention medium. However, it is possible to easily determine the copy. If the camouflage pattern is formed, it is possible to camouflage the difference in reflectance between the first light reflecting portion and the second light reflecting portion in the copy prevention medium. The difference between the reflection portions can be hardly distinguished visually. Further, a method for producing a copy prevention medium according to the present invention is a method for producing a copy prevention medium having a first light reflection portion and a second light reflection portion, wherein a step of preparing a base material, To
The step of forming a first underlayer, the presence or absence or content of fine powder per predetermined area on the substrate, or the average particle size of the fine powder, or the film thickness is different from that of the first underlayer. Forming a metal thin film layer on the first and second base layers, and forming the metal thin film layer on the first base layer into a first light reflecting portion. And the step of using the metal thin film layer on the second underlayer as the second light reflecting portion, so that the surface roughness of the first metal thin film layer and the second metal thin film layer can be easily adjusted. Of the first light reflecting portion and the second light reflecting portion, so that the first light reflecting portion and the second light reflecting portion of the copy can be different. There is a difference in the reproduction state with the light reflection part, making it difficult to forge by adjusting the density of the copying machine. It can clearly judge by visual observation in which is copied, it is possible to suppress the forgery by a copying machine of a copying prevention medium can be created copy protection medium that can prevent the use of copied material.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the principle of a copy protection medium according to the present invention.

FIG. 2 is a plan view showing a copy protection medium according to the present invention.

FIG. 3 is a schematic cross-sectional view for explaining a latent pattern area S of the copy protection medium according to the present invention.

FIG. 4 is a sectional view showing a completed copy prevention medium.

[Description of Signs] 1 Copy prevention medium 2 Copy 3 Latent pattern 3 'Check pattern 4 Individual information 5 Camouflage pattern 11, 11-1, 11-2 Base material 12-1, 12-2, 12-3 Underlayer 13 Metal thin film layer 14 Anchor layer 15 Camouflage pattern printing layer 16 Individual information printing layer 17 Protective layer A First light reflecting part B Second light reflecting part C Third light reflecting part A 'Reproduction of first light reflecting part Area B 'Reproduction area of second light reflection section C' Reproduction area of third light reflection section K Individual information display area K 'Reproduction area of individual information display area S Latent pattern area S' Reproduction area of latent pattern area

Claims (10)

[Claims] A first light reflecting portion including a first metal thin film layer and a first underlayer; a second light reflecting portion including a second metal thin film layer and a second underlayer. Wherein the first underlayer and the second underlayer are different, and the surface roughness of the first metal thin film layer is different from the surface roughness of the second metal thin film layer. A copy-protecting medium characterized by the above-mentioned. 2. The copy protection medium according to claim 1, wherein said first metal thin film layer and said second metal thin film layer are made of the same material. 3. The method according to claim 1, wherein the first underlayer does not contain fine particles,
3. The copy protection medium according to claim 1, wherein the second underlayer contains fine particles. 4. The content of fine particles contained in the first underlayer per predetermined area is different from the content of fine particles contained in the second underlayer per predetermined area. A copy-protecting medium as described. 5. An average particle diameter of fine particles included in the first underlayer per predetermined area is different from an average particle diameter of fine particles included in the second underlayer per predetermined area. 5. The copy protection medium according to any one of items 1 to 4, 6. The copy protection medium according to claim 1, wherein the thickness of the first underlayer is different from the thickness of the second underlayer. 7. The copy prevention medium according to claim 1, wherein a latent pattern is formed by the first light reflection portion and the second light reflection portion provided adjacent to each other. . 8. The copy prevention medium according to claim 1, wherein a camouflage pattern is formed on the first light reflecting portion and the second light reflecting portion. 9. The copy protection medium according to claim 1, wherein individual information is formed on the first light reflecting portion and the second light reflecting portion. 10. A method for producing a copy prevention medium having a first light reflecting portion and a second light reflecting portion, comprising: preparing a base material; and forming a first underlayer on the base material. Forming a second underlayer on the base material, the presence or absence or content of fine particles per predetermined area or the average particle size of the fine particles, or the film thickness is different from the first underlayer. Forming; forming a metal thin film layer on the first underlayer and the second underlayer; forming a first light reflecting portion on the metal thin film layer on the first underlayer. And a step of using the metal thin film layer on the second underlayer as a second light reflecting portion.