JPH0895491A - Brittle seal - Google Patents

Abstract

PURPOSE: To provide a brittle seal for preventing optical forgery and alteration which makes layer constitution and constituting material hardly discriminatable, has unique color tone to permit authenticity discrimination and especially, is formed by laminating ceramics. CONSTITUTION: This brittle seal is formed by successively providing the surface of a base material 2 with a function layer 3, a partially formed peeling layer 4 and an adhesive layer 5 and forming this function layer 3 by laminating plural ceramic materials varying in refractive indices. The function layer 3 is provided with the nature to reflect rays of a specific wavelength region or to allow the transmission thereof by alternately combining ceramics of a low-refractive index layer 7 and high-refractive index layer 6. Since the film thicknesses of the function layer 3 are changed by changing viewing angles, the wavelength regions shift and the colors are visible differently. Since the seal remains after peeling, the peeling after once adhering is discriminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brittle seal, and more particularly to a brittle seal which prevents reuse and makes counterfeiting or tampering difficult.

[0002]

2. Description of the Related Art Conventionally, means for preventing forgery has been such that it is difficult to imitate the article itself, or by attaching something difficult to imitate to the article as proof of authenticity, There is something that makes it possible to distinguish between genuine and fake. For example, in the former, fine processing is applied to itself, such as securities such as banknotes, or it is colored in a color that is difficult to imitate. This makes it possible to prevent illegal copying by making it difficult to forge.

Further, due to advances in printing reproduction technology or advances in digital technology such as copying machines, it becomes possible to easily reproduce even if fine processing as described above is performed or colors are hard to imitate. In response to various technologies, processing technology is becoming finer, making it more difficult to copy and forge.

Since the latter is only attached to an article and is easy to handle, it has been widely used. For example, there is a seal on which an image formed of a relief hologram is formed. This has an effect that a hologram image is formed in an uneven shape and can be mass-produced by embossing. In particular, considering the layer structure, it is difficult to peel off the seal, or it is configured to make it difficult to regenerate after peeling, if you stick it on a card, banknote, certificate etc. once as an object of use, peel it off It is possible to tell at a glance that some or all of the hologram has been destroyed and that some kind of alteration such as falsification has been made to the article as well as forgery.

[0005] As such a prior art, Jitsuko Sho-46-
As described in Japanese Patent No. 4432, there is one in which a release layer is partially provided on the back side of a transparent plastic substrate, which has a pattern, and an adhesive layer is provided thereon.
Further, as described in Japanese Utility Model Publication No. 3-7372, there is a transparent film substrate on which a transparent release layer is partially formed, and a print display layer is provided on the transparent release layer. As described in Japanese Utility Model Publication No. 4-17554, a readhesion preventive pressure-sensitive adhesive sheet is disclosed.

Further, in the case of a seal having a forgery prevention function, there are demands such that it can be easily discriminated whether it is a genuine product or a counterfeit product, it is difficult to discriminate the structure of the seal itself, and the forgery prevention function does not change due to the surrounding environment. is there.

[0007]

However, since the true / false discrimination due to the high degree of miniaturization will be overlooked unless a very careful view such as enlarging a fine portion or comparing with a genuine article is observed. In addition, the brightness of the place and the confirmation time must be taken sufficiently, and it is becoming inconsistent with the actual transaction status. Moreover, even if the material is special, it cannot be made to be a peculiar material, and the cost becomes high, which is not realistic. Further, since the hologram as described above has a simple hologram principle and a simple structure such as layers, it is apt to be forged, so that the anti-counterfeit effect due to the hologram is weakened.

Further, the above-mentioned release layer-patterned sheet or readhesion-preventing pressure-sensitive adhesive sheet exerts its function by being peeled off, and in the state where these are stuck to those for preventing forgery. However, it is difficult to determine the sheet itself.

Therefore, the present invention is a brittle seal for preventing forgery and tampering, which has a unique color tone that makes it difficult to discriminate the layer constitution and the constituent materials, and can discriminate between genuine and false, and is formed by laminating ceramics in particular. An object of the present invention is to provide a brittle seal for preventing optical forgery and tampering.

[0010]

The invention according to claim 1 is
The brittle seal is characterized in that a functional layer, a partially formed release layer, and an adhesive layer are sequentially provided on a base material, and the functional layer is formed by laminating a plurality of ceramic materials having different refractive indexes.

The invention according to claim 2 is the brittle seal according to claim 1, wherein the partially formed peeling layer is formed in a pattern.

The invention according to claim 3 is the brittle seal according to any one of claims 1 and 2, characterized in that a colored layer is provided between the functional layer on the surface of the adhesive layer side and the partial molding release layer. .

The invention according to claim 4 is the brittle seal according to any one of claims 1 to 3, wherein the functional layer comprises a combination of a high refractive index layer and a low refractive index layer.

The invention according to claim 5 is characterized in that the combination of the high refractive index layer and the low refractive index layer is formed by alternately arranging the combination of the high refractive index layer and the low refractive index layer. The brittle seal according to claim 4.

In the invention according to claim 6, the low refractive index layer is selected from the group consisting of magnesium fluoride, calcium fluoride, cerium fluoride, aluminum fluoride, silicon dioxide, aluminum oxide and magnesium oxide, or Is a mixture, the high refractive index layer is zinc sulfide, zirconium dioxide, titanium dioxide, cerium dioxide, tantalum oxide,
The brittle seal according to claim 5, which is one or a mixture selected from zinc oxide and indium oxide.

[0016]

According to the brittle seal of the present invention, the functional layer is alternately combined with a ceramic having a low refractive index and a ceramic having a high refractive index to reflect or transmit a light beam in a specific wavelength range, and the viewing angle Since the film thickness of the functional layer is changed by changing, the wavelength regions of transmission and reflection are shifted, and the colors appear different, which makes it easy to discriminate.

When the seal is peeled off by the peeling layer,
While the other layer is peeled from the peeling layer, the portion of the other layer not in contact with the peeling layer is destroyed, part of the layer remains on the adherend, and the other is attached to the peeled seal.

Further, by forming a colored layer as a lower layer, the transfer foil can be colored without affecting the change in color of transmitted light or reflected light and the transfer of the functional layer to the transferred substrate, It is easier to see, and the type of color can be selected. Further, by forming the release layer into a pattern, the portion destroyed at the time of release appears as a specific pattern, mark or character having the above optical characteristics.

The present invention will be described in detail below with reference to the drawings. 1 is a cross-sectional view showing the structure of the brittle seal of the present invention, FIG. 2 is a cross-sectional view showing the state before and after peeling of the brittle seal of FIG. 1, and FIG. 3 is a brittle seal of another embodiment of the present invention. 4 is a cross-sectional view showing the structure of FIG. 4, FIG. 4 is a cross-sectional view showing a state before and after peeling of the brittle seal of FIG. 3, and FIG.
FIG. 6 is an explanatory view for explaining a peeled state by the brittle seal of the example in FIG. 6, FIGS. 6 and 7 are graphs showing a visible spectrum of a functional layer by the brittle seal of the present invention, and FIG. 8 is a diagram for the brittle seal of the present invention. It is a graph showing the visible spectrum of the transfer foil as a comparative example.

1 shows a brittle seal according to the present invention, in which a functional layer 3, a partially formed peeling layer 4 and an adhesive layer 5 are sequentially laminated on a base material 2. The functional layer 3 is a ceramic layer including a high refractive index layer 6 and a low refractive index layer 7. Further, the other surface of the base material 2 may be provided with a printing layer 8 such as a picture or a character within a range that does not cause an obstacle, and a protective layer 9 may be provided as necessary to protect this.

Next, FIG. 3 is a sectional view showing the structure of another embodiment of the present invention, in which a functional layer 3, a partially formed release layer 4, a coloring layer 10 and an adhesive layer 5 are sequentially laminated on a base material 2. Has been done. The functional layer 3 is a ceramic layer including a high refractive index layer 6 and a low refractive index layer 7. On the other surface of the base material 2, a print layer such as a picture or a character may be provided in a range that does not cause an obstacle,
A protective layer can be provided as necessary to protect this.

The base material 2 is required to have sufficient transparency so that the functional layer 4 can be seen through it, and it is sufficient that it has a certain degree of rigidity and surface smoothness, and is not particularly limited. Instead, for example, a polymer film such as a polyester film or a polyolefin film can be used. It is also possible to color with a coloring agent within the range where there is no influence.

The functional layer 3 is formed by alternately laminating a plurality of ceramics having different refractive indexes with a specific film thickness.
As the low refractive index layer 7, magnesium oxide (refractive index n =
1.6), silicon dioxide (n = 1.5), and magnesium fluoride (n = 1.4), and titanium dioxide (n = 2.4) and zirconium dioxide as the high refractive index layer 7. (N = 2.0) and zinc sulfide (n = 2.3) and one of them are laminated in a predetermined thickness. The functional layer 3 can also be provided with a plurality of layers made of the above combinations. In the present embodiment, materials other than those listed above can be used as long as they satisfy the laminating conditions of the constituent layers.

The optical path length in the thin film is changed by reflecting or transmitting a light ray in a predetermined wavelength range to the functional layer 3 and changing the viewing angle, and the color of the transmitted light or the reflected light is changed. . As a result, the anti-counterfeit property is exhibited.

Any film forming method can be used as long as the thickness of the functional layer 3 can be controlled. Among them, the dry method is superior for the formation of a thin film, and includes a normal vapor deposition method, a physical vapor deposition method such as sputtering, and a CVD method.
Chemical vapor deposition methods such as the method can be used.

The total thickness of the functional layer 3 is preferably 1 μm or less. If the thickness exceeds 1 μm, the flexibility becomes poor and the functional layer 3
This is because cracks may occur in the.

The partially formed peeling layer 4 must be smaller than the adhesive force of the adhesive layer 5 to an object to be adhered, such as paper, plastic, etc., which satisfies this requirement and is close to the refractive index of the base material 2. It may be anything as long as it is. It may be an organic material or an inorganic material. Therefore, the peeled portion (the portion that remains on the adherend)
It is sufficient that the adhesiveness of the adhesive layer is greater than the adhesiveness of the release layer, and the portion remaining on the substrate must have good adhesion of the functional layer to the substrate. Any pattern can be used as long as it can be visually identified.
Characters and the like can be used, and can be arbitrarily selected according to the intended use.

The adhesive layer 5 has a higher adhesiveness than that of the above-mentioned partial-formation peeling layer 4 and may deteriorate the functional layer 3 or
If it is not a problem, a commonly used adhesive can be used. Examples include, but are not limited to, vinyl chloride-vinyl acetate copolymer, acrylic adhesive, and polyester polyamide.

FIG. 2 is a cross-sectional view showing the brittle seal 1 of the present invention before and after peeling, in which a base material 2, a functional layer 3, a partially formed peeling layer 4 formed in a pattern, and an adhesive layer 5 are sequentially laminated. It becomes. By forming the partially formed peeling layer 4 in a pattern, the bonding surface of the brittle seal 1 and the bonding surface of the adherend 12 are bonded to each other as shown in FIG. Only the portion where the partially molded peeling layer 4 is formed remains, and only the broken portion of the functional layer 3 remains in the brittle seal 1, and the forgery prevention pattern 11 appears from these.

Similarly, FIG. 4 is a cross-sectional view showing a state before and after peeling of the brittle seal of another embodiment of the present invention, in which the base material 2, the functional layer 3, the coloring layer 10 and the partially formed peeled pattern are formed. The layer 4 and the adhesive layer 5 are sequentially laminated. By forming the partially formed peeling layer 3 in a pattern, the bonding surface of the brittle seal 1 and the bonding surface of the adherend 12 are bonded to each other as shown in FIG. Only the portion where the partially formed peeling layer 4 is formed remains, and only the broken portion of the colored layer 10 remains in the brittle seal 1, and the forgery prevention pattern 11 appears from these.

As a method for forming the pattern of the partially formed peeling layer 4, conventionally known gravure printing or the like can be used.

[0032]

EXAMPLES The present invention will be described in detail below with reference to examples. The visible spectrum of the brittle seal of the present invention prepared and the brittle seal of the present invention prepared for comparison with each other were measured by an ultraviolet / visible spectrophotometer, and the brittle fracture test was conducted as shown in FIG. A brittle seal having a partially formed peeling layer formed with was prepared and actually bonded to an adherend to evaluate the peeled state.

Example 1 A polyester film having a thickness of 12 μm was used as a substrate. In the functional layer, silicon dioxide was used as the low refractive index layer and titanium dioxide was used as the high refractive index layer, and the number of layers was three. The total film thickness was 0.5 μm. After forming the functional layer on the substrate, the partially formed release layer was formed by printing in a pattern as shown in FIG. 3, for example. After that, an adhesive layer was provided to make a seal.

Table 1 shows the constitution of the brittle seal of this example, the state of the layers, and the evaluation results. The visible spectrum of this seal is shown in FIG. The center wavelength of visible light absorption perpendicular to the film was 580 nm, and when visible light was incident at an angle of 45 degrees, the center wavelength was shifted to the lower wavelength side and a color change occurred. In addition, this seal had a sufficient function as a brittle seal.

Example 2 A 12 μm thick polyester film was used as the substrate, magnesium fluoride was used as the low refractive index layer and zinc sulfide was used as the high refractive index layer for the functional layers, and the number of layers was Has three layers. Total film thickness is 0.5 μm
And After forming the functional layer on the substrate, the partially formed release layer was formed by printing in a pattern. Then, an adhesive layer was provided to make a seal.

Table 1 shows the constitution of the brittle seal of this example, the state of the layers, and the evaluation results. The center wavelength of visible light absorption perpendicular to the film is 580 nm, and when visible light is incident at an angle of 45 degrees, the center wavelength shifts to the lower wavelength side,
A color change occurred. In addition, this seal had a sufficient function as a brittle seal.

Example 3 A polyester film having a thickness of 12 μm was used as the substrate, silicon dioxide was used as the low refractive index layer and titanium dioxide was used as the high refractive index layer for the functional layer, and the number of layers was There were three layers. The total film thickness was 0.5 μm. After forming the functional layer on the substrate, a colored layer was provided, and the partially formed release layer was formed by printing in a pattern as shown in FIG. 3, for example. Then, an adhesive layer was provided to make a seal.

Table 1 shows the constitution of the brittle seal of this example, the state of the layers, and the evaluation results. The center wavelength of visible light absorption perpendicular to the film is 580 nm, and when visible light is incident at an angle of 45 degrees, the center wavelength shifts to the lower wavelength side,
A color change occurred. In addition, this seal had a sufficient function as a brittle seal.

[0039]

[Table 1]

Although the present invention has been described with reference to the examples having typical configurations, the present invention is not limited to these examples and may be freely modified within the technical scope described in the claims. , A functional layer can be configured.

[0041]

According to the brittle seal of the present invention, a functional layer, a partially formed release layer, and an adhesive layer are sequentially provided on a base material, and the functional layer is laminated with a plurality of ceramic materials having different refractive indexes to a specific thickness. This shows the property of reflecting or transmitting light rays in a specific wavelength range, and the film thickness of the functional layer changes depending on the viewing angle, so the optical path length in the thin film changes, and the color of transmitted light or reflected light changes. It looks strange. As a result, the colors look different, so that it is easy to distinguish and the anti-counterfeit property is exhibited.

When the seal is peeled off by the peeling layer,
While the other layer peels from the peeling layer, the part of the other layer that is not in contact with the peeling layer is destroyed, part of it remains on the adherend, and the other becomes attached to the peeled seal and is once bonded. After that, it can be seen that it was peeled off.

By forming a colored layer in the lower layer,
The seal can be colored without being adversely affected by the color change of the transmitted light or the reflected light, which is easier to see and the color type can be selected.

Further, by forming the release layer into a pattern such as a specific pattern, mark or character, a specific pattern having the characteristics of the functional layer can be formed.

As described above, the anti-counterfeiting effect is extremely high,
It has an excellent effect that the conventional brittle seal does not have.

[0046]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a brittle seal of the present invention.

FIG. 2 is a cross-sectional view showing a state before and after peeling the brittle seal of FIG.

FIG. 3 is a cross-sectional view showing the structure of a brittle seal according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a state before and after peeling of the brittle seal of FIG.

FIG. 5 is an explanatory diagram illustrating a peeled state by the brittle seal of the embodiment in FIGS. 2 and 4.

FIG. 6 is a graph showing a visible spectrum of a functional layer formed by the brittle seal of the present invention in Example 1.

FIG. 7 is a graph showing a visible spectrum of a functional layer according to the brittle seal of the present invention in Example 3.

FIG. 8 is a graph showing a visible spectrum of a transfer foil as a comparative example.

[Explanation of symbols]

1 ... Brittle seal 2 ... Substrate 3 ... Functional layer 4 ... Partial release layer 5 ... Adhesive layer 6 ... Low refractive index layer 7 ... High refractive index layer 8 ... Printing layer 9 ... Protective layer 10 ... Colored layer 11 ... Forgery prevention Pattern 12 ... Object to be bonded

Claims (6)

[Claims] 1. A brittle seal characterized in that a functional layer, a partially formed release layer and an adhesive layer are sequentially provided on a base material, and the functional layer is formed by laminating a plurality of ceramic materials having different refractive indexes. . 2. The brittle seal according to claim 1, wherein the partially formed release layer is formed in a pattern. 3. The brittle seal according to claim 1, wherein a colored layer is provided between the functional layer on the side of the adhesive layer and the partially molded release layer. 4. The brittle seal according to claim 1, wherein the functional layer comprises a combination of a high refractive index layer and a low refractive index layer. 5. The brittleness according to claim 4, wherein the combination of the high refractive index layer and the low refractive index layer is formed by alternately arranging the combination of the high refractive index layer and the low refractive index layer. sticker. 6. The low refractive index layer is one or a mixture selected from the group consisting of magnesium fluoride, calcium fluoride, cerium fluoride, aluminum fluoride, silicon dioxide, aluminum oxide and magnesium oxide, and has a high refractive index. The brittle seal according to claim 5, wherein the refractive index layer is one or a mixture selected from zinc sulfide, zirconium dioxide, titanium dioxide, cerium dioxide, tantalum oxide, zinc oxide and indium oxide.