JP3193995B2 - Anti-counterfeit films - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a film for preventing forgery or the like .

[0002]

2. Description of the Related Art Heretofore, in cards such as an identification card and a driver's license, a reflection sheet to which light recursion is applied has been used. For example, a sheet having a retroreflective information area and / or a retroreflective background area is disclosed in JP-A-50-12919.
No. 5, Japanese Utility Model Publication No. 1-31513 and the like are known. On the other hand, there is a film shown in FIG. 19 as an application film of a retroreflective sheet in consideration of decorativeness. This is, in order from the surface, a transparent surface film a, a glass ball fixing layer b, and a metal reflection film e.
And an adhesive layer f and a release paper g. The back surface of the glass sphere fixing layer b holds the glass sphere c so that almost half thereof is buried. The metal reflective film e is deposited on the lower half of the glass sphere c, and the light rays entering the glass sphere c from the front side of the sheet, that is, from above, are reflected again on the sheet surface side. In this sheet, when the light beam enters and exits the glass sphere c, a light dispersion phenomenon occurs, and rainbow-colored reflected light is obtained. Although the original reflection performance is not provided to obtain such rainbow-colored reflected light, it can be said that the sheet is highly decorative. Such sheets are known to those skilled in the art.
It is called a rainbow film.

[0003]

However [0006] In the method proposed in the aforementioned JP-A-50-1291 9 No.5 and real fair 1-31513 Patent like, under substantially normal diffusion light, just film However, there is a disadvantage that the information existing in cannot be completely hidden. Further, with respect to the decorativeness of these sheets, they have a drawback such as poor decorativeness because they are substantially transparent under diffused light. On the other hand, with respect to the rainbow sheet having the above-mentioned structure, in the case of using such a structure, the color of the metal appears due to the presence of the metal reflection film e, and the film becomes grayish and loses vividness. On the other hand, if the metal reflective film e is removed, the glass bulb comes into direct contact with the resin, so the relative refractive index decreases,
The incidence of rainbow decreases. Specifically, when the refractive index of the resin is 1.5, there is a drawback that the refractive index 2.2 of the glass sphere is reduced to 1.47. If the rainbow film is applied to a forgery prevention film, if the information layer is formed below the rainbow film to form a forgery prevention film, the metal reflection film e reflects light almost completely. The display of the information layer located thereunder cannot be visually recognized. If an information layer is formed on the metal reflective film e to form a forgery prevention film, light passes through the information layer until it passes through the surface film a and the glass sphere c and exits. In addition, there is a disadvantage that the presence of the information layer is inevitably visually recognized under ordinary diffused light.
As a result , a sheet having high decorativeness and being sufficiently satisfactory as an anti-counterfeit film has been given up by those skilled in the art despite the strong demands of the market. An object of the present invention is to solve such a problem.

[0004]

In order to solve the above problems, the inventor of the present invention has found that, when air is used as a substance that a transparent sphere such as a glass sphere contacts, the relative refractive index becomes the highest and the degree of rainbow generation becomes high. With this in mind, the present invention has been achieved. Application
The anti-counterfeit film according to the first invention includes a plurality of transparent spheres 3.
, A transparent sphere fixing layer 2, a bonding layer 4, and an information layer 6. Each of the transparent spheres 3 is embedded and held so as to be partially exposed on the back surface of the transparent sphere fixing layer 2. The bonding layer 4 is disposed on the back side of the transparent sphere fixing layer 2 in a state where a part thereof is joined to the transparent sphere fixing layer 2 and another portion is appropriately interposed with the gas layer 11. . The information layer 6 is disposed at an appropriate position on the front side or the back side of the bonding layer 4, and receives information from the front side of the transparent sphere fixing layer 2 so that information held by the information layer 6 can be transmitted from the surface of the transparent sphere fixing layer 2. The information layer is displayed outside, and when visible light is incident, the information layer is hidden by a rainbow appearing in the light dispersion.

[0005]

As shown in FIG. 1, in the case of visible light X, the information existing under the transparent sphere 3 (glass sphere) is hidden by a rainbow appearing due to the dispersion of light and cannot be visually recognized. To elaborate, the location
The visible light X incident on the surface film 1 from A is red.
The light is separated from light to blue-violet light S. For example, with red light R
When the blue light S is considered, the bottom of the transparent sphere 3 is the air layer 11.
The red light R is totally reflected at the position B at the bottom of the transparent sphere 3 and the blue light S is totally reflected at the position B 'at the bottom of the transparent sphere 3 due to the interface with the transparent sphere 3. Thereafter, the red light R passes through the position C on the surface of the transparent sphere 3 and is emitted from the position D to the outside of the film. Further, the blue light S passes through a position C ′ on the surface of the transparent sphere 3,
It is ejected from the position D 'to the outside of the film. UV (ul
(traviolette rays: hereinafter referred to as UV rays)
In the case of Y, the information layer 6 emits colored visible light Z by irradiation, and hidden information that cannot be visually recognized by the visible light X (FIG. 3) can be visually recognized (FIG. 4).

The higher the relative (relational) refractive index of the glass sphere, the smaller the critical angle and the higher the total reflection efficiency. Therefore, the occurrence of rainbow is high. As shown in FIG. 2, a refractive index of 2.2
The critical angle (α) for a transparent sphere 3 (glass sphere) of 0 is about 27 °. The critical angle (β) for a bead (water droplet) having a refractive index of 1.33 is about 48 °. Therefore, in the case where the reflective surface of the transparent sphere 3, that is, the substance in contact with the lower hemisphere, is the gas layer 11 such as air, the relative refractive index is the highest and the occurrence of rainbow is improved.

The optimum configuration of the film according to the present invention is as follows:
In order from the surface, a transparent surface film 1, a transparent sphere fixing layer 2 holding transparent spheres 3, a gas layer 11, a bonding layer 4,
The information layer 6 includes an adhesive 7 and a release paper 8.
Is provided, the information layer 6 is disposed below the gas layer 11. Then, in order to form the gas layer 11 and fix the bonding layer 4 and the transparent sphere fixing layer 2, embossing described later is performed. This embossing can be carried out from the front side of the film or from the back side of the film to obtain the film intended by the present invention. FIG. 5, FIG. 6, and FIG. 7 show the films embossed from the surface of the film. First, the one shown in FIG. 5 is of a type not having the information layer 6, and has an emboss M applied from the surface film 1 side. In this case, only one bonding layer 4 is shown. Next, a film having the information layer 6 will be described with reference to FIGS. In particular, the one shown in FIG. 6 has one bonding layer 4 and FIG.
1 has two tie layers, a first tie layer 40 and a second tie layer 5. What is shown in FIG.
The information layer 6 is arranged at an appropriate position on the surface of the bonding layer 4 in contact with the gas layer 11. In such a configuration, the information layer 6
Since the bonding layer 4 is lower than the bonding layer 4, the bonding layer 4 does not need to be transparent. In particular, in this case, if the coupling layer 4 is made white, it is effective in increasing the luminance. FIG. 7 shows an information layer 6 between the first bonding layer 40 and the second bonding layer 5.
Is provided. In this case, the first bonding layer 40 located above the information layer 6 needs to be transparent. In this case, if the second coupling layer 5 is made white, it is effective in increasing the luminance.

FIG. 8, FIG. 9, and FIG. 10 show the films embossed from the back surface of the film. First, the one shown in FIG. 8 does not have the information layer 6, and the emboss M is applied from the back side of the coupling layer 4. After the embossing M is applied, a release paper 8 is disposed on the back side of the bonding layer 4 via an adhesive 7. Next, a film having the information layer 6 will be described with reference to FIGS. In particular, the one shown in FIG. 9 has one bonding layer 4 and
The one denoted by 0 has two tie layers, a first tie layer 40 and a second tie layer 5. In this case, after embossing M is applied from the back side of the bonding layer 4, the release paper 8 is disposed on the back side of the bonding layer 4 via the adhesive 7. In the configuration shown in FIG. 9, the information layer 6 is disposed at an appropriate position on the surface of the bonding layer 4 in contact with the gas layer 11. In the case of adopting such a configuration, the information layer 6 is formed in the same manner as in the case of the surface embossing described above.
Since the bonding layer 4 is lower than the bonding layer 4, the bonding layer 4 does not need to be transparent. In particular, in this case, if the coupling layer 4 is made white, it is effective in increasing the luminance. In FIG. 10, the information layer 6 is provided between the first coupling layer 40 and the second coupling layer 5. Also in this case, the first bonding layer 40 located above the information layer needs to be transparent.
Also in this case, if the second coupling layer 5 is made white, it is effective in increasing the luminance.

The gas layer 11 is usually an air layer, but may be a layer of another gas such as an inert gas.

The transparent sphere 3 is suitably a glass sphere, but may also be implemented in place of another transparent material such as plastic.

The composition of the information layer 6 is not particularly limited as long as it is a substance that emits light by UV light, and it is possible to employ a fluorescent brightener, an organic fluorescent pigment, an oxide pigment, a sulfide pigment, or the like. In particular, a phosphor pigment having a luminescent color and an achromatic body color and containing sulfide or oxide as a main component that is stable to light, water, heat, and the like is useful. In particular, a phosphor pigment containing an oxide as a main component and having a white body color and excellent weather resistance is useful. A series of special phosphors and phosphors for identification made by Nemoto Special Chemical Co., Ltd. correspond to this phosphor pigment,
One example is the compound Y ₂ O ₃ : Eu. These compounds can be mixed into a resin having excellent transparency to prepare an ink, and the information layer 6 can be prepared by a known technique such as silk screen printing, offset printing, gravure printing, letterpress printing, or the like. In particular, when the information layer 6 is located on the surface side of the bonding layer 4, if the bonding layer 4 is white, high-luminance emission under UV light can be obtained. When the information layer 6 is located on the back side of the bonding layer 4, the bonding layer 4 is formed of a transparent material in order to secure light transmission.

The composition of the bonding layer will be described. When the film adopts the configuration shown in FIGS. 5, 6, 8 and 9, it is appropriate to make the bonding layer 4 white using a coloring agent such as titanium oxide. The applied resin is polyester resin, polyacryl resin, polyurethane resin, polyvinyl chloride resin, polycarbonate resin, fluorine resin, AS
Resin, EVA resin, polyacetal resin, cellulose resin,
Polyvinyl acetate resins, polyethylene resins, thermoplastic resins such as Po Ripuropire <br/> down resins are preferred. Also, the film
In the case of the type having the information layer 6 between the first bonding layer 40 and the second bonding layer 5, that is, those shown in FIGS. 7 and 10, both the first bonding layers 40 are transparent, and the second bonding layer 5 is titanium oxide. White by using a coloring agent such as Resin polyester resin to be applied to the first bonding layer 40, a polyacrylic resin, polyurethane resin, polyvinyl chloride resin, polycarbonate resin, fluorine resin, AS resin, EVA resin, polyacetal resin, fiber-containing resin, polyvinyl acetate resin Thermoplastic resins such as polyethylene resin and polypropylene resin are preferable, and resins having excellent transparency are more preferable.
It is more preferable that the second bonding layer 5 imparts solvent resistance by introducing a functional group into the thermoplastic resin and reacting with a curing agent and / or a curing catalyst that reacts with the reactive functional group. The first bonding layer 40 and the second bonding layer 5 can be implemented by a known technique such as a calendering method and an extrusion method other than the solvent casting method.

Hereinafter, a production example of the present invention will be described. Taking the case of manufacturing a film of the type shown in FIG. 10 as an example, the steps will be described. First, as a pre-process, a resin composition for the transparent ball fixing layer 2 having a thickness of about 10 to 90% of the sphere diameter of the transparent sphere 3 is formed on a polyester film constituting the surface film 1 separately prepared as shown in FIG. After coating to a dry film thickness and drying at room temperature to evaporate the solvent, the transparent spheres 3 are embedded and further dried at about 140 ° C. for about 5 minutes (FIG. 12). The transparent sphere 3 has a refractive index of about 2.0 to 2.40 and a particle diameter of about 5 to 300 μm containing titanium oxide as a main component.
m high refractive glass spheres are suitable. Particularly preferred as the transparent sphere 3 are those having a refractive index of about 2.10 to 2.30 (particularly preferred are 2.15 to 2.25) and a particle diameter of about 10 to 150 μm (particularly preferred). Thing is 30-10
0 μm). When the particle diameter is less than 5 μm, it is difficult to control the embedding into the transparent sphere fixing layer 2.
It is difficult to maintain the adhesion to the substrate. Refractive index is 2.0
If it is less than 3, the generation of iris color due to the dispersion of light is too low, and it is difficult to sufficiently hide the information layer 6. 2.4
In the case of producing glass spheres having a refractive index of more than 0.1, it is extremely difficult to industrially produce transparent glass spheres accurately while preventing crystallization. Then, as shown in FIG. 13, a second bonding layer 5 was formed on a separately prepared polyester film 9 by a casting method using a resin composition containing an acrylic copolymer resin as a main component. The drying temperature at this time is suitably about 150 ° C. for about 5 to 20 minutes, and the thickness is adjusted to 5 to 200 μm, preferably 10 to 200 μm.
It is adjusted to 150 μm, more preferably 15 to 100 μm. When the thickness is less than 5 μm, the hiding power is low even when whitening is performed using titanium oxide or the like.
This is not preferable because it is insufficient to increase the brightness of the information layer 6 during light irradiation. When the thickness is more than 200 μm, the bonding portion between the bonding layer and the transparent sphere fixing layer at the time of hot embossing becomes too wide, and the generation of iris color is unfavorably reduced, and the cost is high. It is not appropriate. Subsequently, as shown in FIG. 14, an information layer 6 was formed on the surface side of the second bonding layer 5 by silk screen printing using an ink containing an oxide pigment, an acrylic copolymer resin and a solvent as main components. The screen used at this time is 10
It is appropriate to use a mesh of about 0-250 mesh and about 1 after printing.
Suitably drying at 50 ° C. for about 3 minutes. Next, as shown in FIG. 15, on the information layer 6, a resin composition containing a basic composition of an ester-based urethane resin, methyl ethyl ketone, and N, N-dimethylformamide was cast on a caster and heated at about 70 ° C. 10 minutes followed by about 10
Hot air drying was performed at 0 ° C. for about 20 minutes to form the first bonding layer 40. At this time, the thickness of the first bonding layer 40 is 10 to 200.
μm, preferably 20 to 150 μm, more preferably 3 μm.
0 to 100 μm. When the thickness is less than 10 μm, the adhesion to the transparent sphere fixing layer during hot embossing is insufficient, and
When it exceeds, the joint portion between the bonding layer and the transparent sphere fixing layer at the time of hot embossing becomes too wide similarly to the second bonding layer described above,
The generation of iris color is undesirably reduced. Further, it is more preferable to adjust the total film thickness of the second coupling layer 5 and the first coupling layer 40 to 210 μm or less. Subsequently, as shown in FIG. 16, the first bonding layer 40 side of the intermediate product shown in FIG. 15 manufactured as described above is opposed to the transparent sphere 3 of the intermediate product shown in FIG. 12 manufactured as described above. Then, it was heated and pressed by the embossing roll 10 with a handle. The temperature of the embossing roll 10 at this time is suitably about 210 ° C. Next, FIG.
As shown in (2), the polyester film 9 on the side on which the heat embossing of the film produced above was performed is peeled off. Subsequently, an acrylic pressure-sensitive adhesive forming the pressure-sensitive adhesive 7 is applied on the release paper 8 so as to have a dry film thickness of 30 μm, and is dried with hot air at about 100 ° C. for about 5 minutes to be bonded to the film to cover the film. An iris-colored bead film with information was completed.
The pressure-sensitive adhesive 7 can be implemented even if it is an adhesive.

In the process shown in FIG. 11 among the above processes, the following configuration can be adopted. A re-peelable acrylic pressure-sensitive adhesive for temporary application is applied on a polyester film serving as a supporting film so as to have a dry film thickness of about 15 μm, and dried with hot air at about 100 ° C. for about 5 minutes. It is bonded to the untreated side of the corona discharge treated fluorine film. The following are the fluorine-based films used for this. Polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-
Hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene-perfluoroalkylvinyl ether copolymer, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, chlorotrifluoroethylene-ethylene copolymer,
Polyvinylidene fluoride, polyvinyl fluoride and the like are listed. Particularly, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polyvinylidene fluoride, and polyvinyl fluoride are particularly useful from the viewpoint of price, processability, and the like. Next, the resin composition for the transparent sphere fixing layer 2 used in the step shown in FIG. 11 is similarly processed on one side subjected to the corona discharge treatment. The following steps are the same as the above-described production steps, except that a step of peeling off the re-peelable pressure-sensitive adhesive polyester film bonded to the fluorine film is added as a final step.

In the above-described steps shown in FIG. 12, the following configuration can be adopted. That is, as shown in FIG. 18, a surface film 12 is formed on a polyester film, and a transparent ball fixing layer 2 is formed thereon. Except that the polyester film is finally peeled off from the surface film 12, it is the same as that described in the description of the above-mentioned manufacturing process. Examples of the resin composition for the surface film 12 and the transparent sphere fixing layer 2 include polyester resin, polyacryl resin, polyalkyd resin, polyurethane resin, polyvinyl chloride resin, polycarbonate resin, fluorine resin, acrylic silicone resin and the like. A resin having good properties is used.
If necessary, three-dimensional curing can be performed by introducing a functional group into the resin composition, which can be a main component of the film composition, and reacting with a curing agent and / or a curing catalyst that reacts with the reactive functional group. .

[0016]

Embodiments of the present invention will be described below. First, as a pre-process, as shown in FIG. 11, on a separately prepared polyester film 1, a resin composition for a glass bead fixing layer, which is a transparent sphere fixing layer 2, having the following composition is used. %, And dried at room temperature to evaporate the solvent. Then, the glass spheres were embedded, and further dried at 140 ° C. for 5 minutes. As the glass sphere, a high refractive glass sphere mainly composed of titanium oxide and having a refractive index of 2.23 and a particle diameter of about 67 to 73 μm was used. Basic formulation Oil-free alkyd resin 100 (solid content: 50%, solvent: xylene) Butylated melamine resin 10 (solid content: 60%, solvent: xylene, butanol) Curing accelerator 0.5 (acid value; 400) A second bonding layer 5 having a thickness of 20 μm was formed on a separately prepared polyester film 9 by a casting method using a resin composition having the following basic composition. The drying temperature at this time was 150 ° C. for 5 minutes. Basic composition Hydroxyl-containing acrylic copolymer resin 70 (solid content; 50%, solvent: toluene, butyl acetate) Methylated melamine resin 12 (solid content: 60%, solvent: xylene, butanol, methanol) Polyester plasticizer 2 rutile titanium 16 Subsequently, the information layer 6 was formed on the surface side of the second bonding layer 5 by silk screen printing using an ink having the following composition. The screen used at this time was 250 mesh and dried at 150 ° C. for 3 minutes after printing. Basic composition Oxide pigment 50 (Y2O3: Eu) Acrylic copolymer resin 30 (solid content: 50%, solvent: toluene, butyl acetate) Auxiliary agent 3 Solvent 17 (cyclohexanone, Solvesso 100) The resin composition consisting of the basic composition was cast on a caster and dried with hot air at 70 ° C. for 10 minutes and then at 100 ° C. for 20 minutes to a thickness of 60 μm.
Was prepared and used as the first bonding layer 40. Basic composition Ester urethane resin 50 Methyl ethyl ketone 20 N, N-dimethylformamide 30 100% modulus of the urethane resin is 70 kg
/ Cm 2, tensile strength is 580 kg / cm 2, and elongation is 700%. Then the intermediate product of the transparent sphere 3 serving as the bulb of Figure 12, which is prepared as described above, heat and pressure molding the bonding layer 40 of the intermediate product of Figure 15 made with counter arranged so Pattern with embossing roll did. The temperature of the embossing roll at that time was 210 ° C. Next, the polyester film on the side on which the heat embossing was performed was peeled off. Then, the dry film thickness is 3 on the release paper.
Acrylic pressure-sensitive adhesive is applied to a thickness of
It was dried with hot air at 5 ° C. for 5 minutes and bonded to the film.

As a result, depending on the visible light, the information layer 6
Was completely invisible, and at the same time, a highly decorative film having a high luminance iris color was obtained. And UV
At the time of light irradiation, hidden information of the information layer 6 was visually recognized.

[0018]

According to the first invention of the present application, for a film such as a forgery prevention film that presents internal information by irradiating UV light, the information is hidden by visible light and is not visible due to the rainbow that appears due to the dispersion of light. By irradiating with ultraviolet rays (UV rays), the information layer emits colored visible rays, and hidden information that cannot be seen with visible rays can be visually recognized. Further, it has become possible to provide high decorativeness having a high luminance iris color.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the operation of a film according to the present invention.

FIG. 2 is a diagram illustrating a refractive index of a transparent sphere 3;

FIG. 3 is a plan view showing one embodiment of a film according to the present invention.

FIG. 4 is a plan view showing the above embodiment of the film according to the present invention.

FIG. 5 is a schematic sectional view showing one embodiment of a film according to the present invention.

FIG. 6 is a schematic sectional view showing another embodiment of the film according to the present invention.

FIG. 7 is a schematic sectional view showing still another embodiment of the film according to the present invention.

FIG. 8 is a schematic sectional view showing still another embodiment of the film according to the present invention.

FIG. 9 is a schematic sectional view showing another embodiment of the film according to the present invention.

FIG. 10 is a schematic sectional view showing still another embodiment of the film according to the present invention.

FIG. 11 is an explanatory diagram of a film production process according to the present invention.

FIG. 12 is an explanatory diagram of a film production process according to the present invention.

FIG. 13 is an explanatory diagram of a film production process according to the present invention.

FIG. 14 is an explanatory diagram of a film production process according to the present invention.

FIG. 15 is an explanatory diagram of a film production process according to the present invention.

FIG. 16 is an explanatory diagram of a film production process according to the present invention.

FIG. 17 is an explanatory diagram of a film production process according to the present invention.

FIG. 18 is an explanatory diagram of a production process of another embodiment of the film according to the present invention.

FIG. 19 is a schematic sectional view of a conventional rainbow film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface film 2 Transparent sphere fixing layer 3 Transparent sphere 6 Information layer 40 1st joining layer 5 2nd joining layer

Claims (1)

(57) [Claims] 1. A transparent sphere comprising a plurality of transparent spheres, a transparent sphere fixing layer, a bonding layer, a gas layer, and an information layer, wherein each of the transparent spheres is partially exposed on the back surface of the transparent sphere fixing layer. The bonding layer is partially bonded to the transparent sphere fixing layer, and the other portion is provided on the back side of the transparent sphere fixing layer with an appropriate gas layer interposed therebetween. The information layer is disposed at an appropriate position on the front side or the back side of the bonding layer, and receives the ultraviolet light from the transparent sphere fixing layer surface side, thereby fixing the information held by the transparent sphere fixing layer. An anti-counterfeiting film, which is displayed from the surface of the layer to the outside and, when visible light is incident, the information layer is hidden by a rainbow that appears due to the dispersion of light.