Laminate for forgery prevention, accessory of laminate for forgery prevention, and method for producing same

Abstract

To provide a laminate for forgery prevention having high reading efficiency of reflected light, an accessory of the laminate for forgery prevention, and a method for producing the same.SOLUTION: A laminate for forgery prevention comprises a transparent substrate and a thin line pattern formed on one surface of the transparent substrate, where a reflection angle R99 of 99% or more of reflection light of reflection light corresponding to light perpendicularly incident on the thin line pattern from the other surface of the transparent substrate is 0.30 degrees or less.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a counterfeit prevention laminate, an accessory to the counterfeit prevention laminate, and a method for producing the same. [Background technology]

[0002] As a measure to prevent the distribution of counterfeit goods, a system is known in which a two-dimensional code or an RF (Radio Frequency Identification) tag is attached to a product to determine whether the product is genuine. For example, Patent Document 1 discloses an authenticity determination device that reads identification information of an object with a mobile terminal, and uses the information to determine whether the object is genuine or not, and also enables confirmation of distribution information of the object. Furthermore, for example, Patent Document 2 discloses a determination device that determines the authenticity of a hologram image formed by a diffraction pattern. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-123108 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-307172 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when using RF tags as described above as a means to prevent counterfeiting, a dedicated data read / write device is required to read the IC chip information in the RF tag, and it is not realistic for end customers, especially general consumers, to purchase expensive dedicated data read / write devices.

[0005] Furthermore, two-dimensional codes and hologram images can be easily copied, and information on RF tags can also be easily read and rewritten, making it possible to impersonate or copy products. As such, conventional measures to prevent the distribution of counterfeit goods still have security problems.

[0006] Therefore, the present inventors have developed a new method for determining authenticity, in which a counterfeit-preventive laminate having a fine line pattern is irradiated with light and the authenticity is determined by the reflected light. This method has the advantage of being difficult to counterfeit and is unlikely to impair the design of the product to which it is attached. However, there is room for improvement in the efficiency of reading the reflected light, and reading errors can sometimes require multiple readings, so further improvement is desired.

[0007] The present invention has been made in view of the above-mentioned problems, and has an object to provide an anti-counterfeiting laminate having high efficiency in reading reflected light, as well as accessories to the anti-counterfeiting laminate and a method for manufacturing the same. [Means for solving the problem]

[0008] That is, the present invention is as follows. [1] A transparent substrate; a thin line pattern formed on one surface of the transparent substrate; Of the reflected light corresponding to light that is incident perpendicularly to the thin line pattern from the other surface of the transparent substrate, a reflection angle R of 99% or more of the reflected light 99 is 0.30 degrees or less, Anti-counterfeit laminate. [2] The reflection angle R of 90% or more of the reflected light 90 is less than 0.25 degrees, The counterfeit prevention laminate according to [1]. [3] The reflection angle R 99 The reflection angle R of 80% or more of the reflected light 80 The ratio (R 80 / R 99 ) is 0.27 or more, The counterfeit prevention laminate according to [1] or [2]. [4] The total light transmittance of the transparent substrate is 50% or more. The anti-counterfeit laminate according to any one of [1] to [3]. [5] The thickness of the transparent substrate is 10 to 100 μm. The anti-counterfeit laminate according to any one of [1] to [4]. [6] an adhesive layer covering the thin line pattern on one surface of the transparent substrate; The haze of the adhesive layer is greater than 50%. The counterfeit prevention laminate according to any one of [1] to [5]. [7] an adhesive layer covering the thin line pattern on one surface of the transparent substrate; The haze of the adhesive layer is 50% or less. The counterfeit prevention laminate according to any one of [1] to [6]. [8] An adherend; and the anti-counterfeit laminate according to any one of [1] to [7] attached to the adherend. Anti-counterfeit laminate accessories. [9] The surface of the adherend to which the anti-counterfeit laminate is attached is a surface in which 99% or more of the reflected light corresponding to light incident perpendicularly to the surface has a reflection angle of 0.30 degrees or less. [8] An accessory to the anti-counterfeit laminate.

[10] An attachment step of attaching the anti-counterfeit laminate according to any one of [1] to [7] to an adherend, The surface of the adherend to which the anti-counterfeit laminate is attached is a surface in which 99% or more of the reflected light corresponding to light incident perpendicularly to the surface has a reflection angle of 0.30 degrees or less. Method for manufacturing anti-counterfeit laminate accessories. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a counterfeit prevention laminate having high efficiency in reading reflected light, as well as accessories to the counterfeit prevention laminate and a method for manufacturing the same. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing an example of how the authenticity determining device of the present embodiment is used; [Figure 2] 1 is a perspective view of the anti-counterfeit laminate of the present embodiment as viewed from the transparent substrate side. [Figure 3] 1 is a cross-sectional view of the anti-counterfeit laminate of the present embodiment attached to an adherend. FIG. [Figure 4] 1 is a diagram for explaining the degree of diffusion of reflected light corresponding to perpendicularly incident light, where A shows an aspect where the reflection angle is narrow, and B shows an aspect where the reflection angle is wide. [Figure 5] 5 is a graph showing the diffusion of the reflected light shown in FIGS. 4A and 4B, with the horizontal axis representing the reflection angle and the vertical axis representing the amount of light. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings as necessary, but the present invention is not limited to this, and various modifications are possible without departing from the spirit of the present invention. In the drawings, the same elements are given the same reference numerals, and redundant explanations will be omitted. Furthermore, positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios of the drawings are not limited to those shown in the drawings.

[0012] 1. Anti-counterfeit laminate The anti-counterfeiting laminate of this embodiment has a transparent substrate and a thin line pattern formed on one surface of the transparent substrate, and has a reflection angle R of 99% or more of reflected light (hereinafter simply referred to as "reflected light") corresponding to light that is incident perpendicularly to the thin line pattern from the other surface of the transparent substrate. 99 is less than 0.30 degrees.

[0013] Before describing the details of the anti-counterfeit laminate, the configuration of the authentication determination method and authenticity determination device in this embodiment will be described first. FIG. 1 shows a perspective view illustrating an example of how the authenticity determination device 200 is used. As shown in FIG. 1, the authenticity determination device 200 includes, for example, an irradiation device 210 that irradiates light onto the fine line pattern 20 of the anti-counterfeit laminate 100, a light receiving device 220 that receives light reflected from the fine line pattern 20, and a determination unit 230 that performs authenticity determination based on the reflected light. In the example shown in FIG. 1, the irradiation device 210 and the light receiving device 220 are located at approximately the same position.

[0014] As shown in Fig. 1, the authentication method of this embodiment performs authentication based on reflected light. Therefore, in order for the authentication unit 230 to output an authentication result with high accuracy, it is preferable that the reflected light obtained by irradiating a predetermined light is consistent and without variation. However, in reality, there is a problem that the reflected light received by the light receiving device 220 is likely to vary due to unintended scattering, etc. occurring in the anti-counterfeit laminate.

[0015] If the reflected light varies, there is a risk that the determination unit 230 may mistakenly determine that the product is counterfeit, even if it receives reflected light from the fine line pattern on the genuine product. Furthermore, even if such an erroneous determination occurs, it is difficult for the user to determine whether the counterfeit determination result is genuine or due to an erroneous determination by the device. Furthermore, if the reflected light varies, there is a concern that the verification process may take a long time, such as requiring repeated light irradiation and light reception operations to obtain the desired reflected light. Therefore, a counterfeit prevention laminate with high reflected light reading efficiency is desired.

[0016] Next, the configuration of the anti-counterfeit laminate of this embodiment will be described. Fig. 2 shows a perspective view of the anti-counterfeit laminate. As shown in Fig. 2, the anti-counterfeit laminate 100 of this embodiment has a transparent substrate 10 and a fine line pattern 20 formed on one surface 10b of the transparent substrate 10, and may further have an adhesive layer 30 on one surface 10b of the transparent substrate 10 to cover the fine line pattern, as necessary.

[0017] Fig. 3 shows a cross-sectional view of the anti-counterfeit laminate of this embodiment when attached to an adherend. As shown in Fig. 3, the anti-counterfeit laminate 100 of this embodiment can be used by being attached to the surface of an adherend 300 via an adhesive layer 30. In this case, the fine line pattern 20 is located between the transparent substrate 10 and the surface of the adherend 300. The transparent substrate 10 located on the outermost surface also functions as a protective layer that covers the fine line pattern 20.

[0018] Light irradiated from the irradiation device 210 of the authenticity determination device 200 enters the anti-counterfeit laminate from the transparent substrate 10 side, passes through the transparent substrate 10 from surface 10a to surface 10b, and reaches the fine line pattern 20 and adhesive layer 30. A portion of the incident light is reflected, and the reflected light is affected by the fine line pattern. For example, if the fine line pattern acts like a diffraction grating, the reflected light may be diffracted light.

[0019] Here, as shown in Fig. 3, when perpendicular incident light is irradiated, some reflected light is reflected perpendicularly as is, while other reflected light is scattered and reflected at an arbitrary reflection angle. Fig. 4 is a diagram for explaining the degree of diffusion of reflected light corresponding to perpendicularly incident light. Fig. 4 is a diagram of the field of view when the anti-counterfeit laminate 100 in Fig. 3 is viewed in plan from the side where perpendicular incident light is irradiated, i.e., the transparent substrate side, and is a diagram plotting a simulation of where photons of reflected light are reflected when perpendicular incident light is irradiated at the center point.

[0020] In an ideal state where there is no scattering, when normal incident light is irradiated onto the center point, the reflected light returns to the same center point. However, in reality, scattering occurs due to the influence of scattering from each layer, the interface between each layer, or the fine line pattern. Therefore, as shown in Figures 4A and 4B, the reflected light is reflected toward a certain circle centered on the center point. Figure 4A shows an example with a narrow reflection angle, and Figure 4B shows an example with a wide reflection angle. The wider the reflection angle, the greater the variance in the reflected light. The smaller the reflection angle, the higher the proportion of reflected light returning to the center point and the smaller the variance in the reflected light.

[0021] Furthermore, FIG. 5 shows a graph in which the diffusion of the reflected light shown in FIGS. 4A and 4B is represented by the reflection angle on the horizontal axis and the light amount on the vertical axis. As shown in the graph, the smaller the reflection angle, the more photons return to the center point (reflection angle 0 degrees), and the less the variation in the reflected light. In this embodiment, "a reflection angle R of 99% or more of the reflected light" is defined. 99 "The reflection angle R is 0.30 degrees or less" means that when the total integrated value of the amount of reflected light in this graph is 100%, 99% or more of the integrated value is contained in the range of reflection angle 0 to 0.30 degrees. 99 By narrowly defining the width of the reflection light, the variation in the reflected light is suppressed, and therefore the efficiency of reading the reflected light is increased, and it is possible to suppress erroneous determination. The configuration of the anti-counterfeiting laminate of this embodiment will be described in detail below.

[0022] 1.1.Reflectivity As described above, in order to improve the reading efficiency of reflected light, in this embodiment, the reflection angle R of reflected light is set to 99% or more. 99 is set to a value within a predetermined range. This suppresses diffuse reflection, and most of the reflected light is reflected specularly. As a result, the reflected light more accurately reflects the influence of the thin line pattern, and the information that can be read from such reflected light can improve the efficiency of authenticity determination.

[0023] Specifically, the reflection angle R 99 is 0.30 degrees or less, preferably 0.25 degrees or less, 0.20 degrees or less, 0.15 degrees or less, or 0.10 degrees or less.99 By keeping the reflection angle R at 0.30 degrees or less, the reading efficiency of the reflected light tends to be improved. 99 The lower limit of is not particularly limited, but may be 0.01 degrees or more, 0.02 degrees or more, or 0.03 degrees or more.

[0024] In addition, from the viewpoint of improving the reading efficiency of reflected light, a reflection angle R of 90% or more of reflected light is required. 90 , 80% or more of the reflected light reflection angle R 80 , and the reflection angle R of 50% or more of the reflected light 50 can be similarly defined.

[0025] Reflection angle R of 90% or more of reflected light 90 is preferably 0.25 degrees or less, 0.20 degrees or less, 0.15 degrees or less, 0.10 degrees or less, or 0.05 degrees or less. 90 When the reflection angle R is 0.25 degrees or less, the reading efficiency of the reflected light tends to be improved. 90 The lower limit of is not particularly limited, but may be 0.01 degrees or more, and may be 0.02 degrees or more.

[0026] Reflection angle R of 80% or more of reflected light 80 is preferably 0.20 degrees or less, 0.15 degrees or less, 0.10 degrees or less, or 0.05 degrees or less. 80 When the reflection angle R is 0.25 degrees or less, the reading efficiency of the reflected light tends to be improved. 80 The lower limit of is not particularly limited, but may be 0.01 degrees or more, and may be 0.02 degrees or more.

[0027] Reflection angle R of 50% or more of reflected light 50 is preferably 0.15 degrees or less, 0.10 degrees or less, or 0.05 degrees or less. 50 When the reflection angle R is 0.25 degrees or less, the reading efficiency of the reflected light tends to be improved. 50 The lower limit is not particularly limited, but may be 0.01 degrees or more.

[0028] Reflection angle R 90 The reflection angle R 80 The ratio (R 80 / R 99 ) is preferably 0.27 or more, 0.30 to 0.90, 0.35 to 0.80, or 0.40 to 0.70. 80 / R 99 ) is 0.27 or more, the reflection angle R 90 and the reflection angle R 80 The values ​​are relatively close, and the dispersion of the reflected light is narrower. Therefore, the reading efficiency of the reflected light tends to be improved.

[0029] Reflection angle R 90 The reflection angle R 50 The ratio (R 50 / R 99 ) is preferably 0.17 or more, 0.18 to 0.60, 0.19 to 0.50, or 0.20 to 0.40. 50 / R 99 ) is 0.27 or more, the reflection angle R 90 and the reflection angle R 50 The values ​​are relatively close, and the dispersion of the reflected light is narrower. Therefore, the reading efficiency of the reflected light tends to be improved.

[0030] The above-mentioned reflection angles can be adjusted by the composition and thickness of the transparent substrate, the thickness and pattern of the fine lines constituting the fine line pattern, and the composition and surface roughness of the adhesive layer, if used. In addition, the composition can be adjusted by, for example, adding fine particles (metal oxides such as TiO2, ZnO, and ZrO2) with a refractive index different from that of the base material to the transparent substrate or adhesive layer and varying their particle size and content. The reflection angles can also be adjusted by a sandblasting method in which fine particles are bombarded at high speed onto the substrate surface to create surface irregularities, or by coating the substrate surface with a transparent resin. The methods described in the examples can be used to measure the reflected light.

[0031] 1.1.Transparent base material In this embodiment, a transparent substrate is used as the substrate onto which incident light is incident, as shown in Figure 1. Note that "transparent" means that the total light transmittance is 50% or more.

[0032] The material for the transparent substrate is not particularly limited, but examples thereof include transparent inorganic substrates such as glass; and transparent organic substrates such as acrylic acid esters, methacrylic acid esters, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, nylon, aromatic polyamide, polyether ether ketone, polysulfone, polyethersulfone, polyimide, and polyetherimide.

[0033] Among these, polyethylene terephthalate, polyimide, or polyethylene naphthalate is preferred. The use of polyethylene terephthalate tends to improve the productivity and cost reduction effect for producing the anti-counterfeit laminate, and also tends to further improve the adhesion between the transparent substrate and the thin wire. In addition, the use of polyimide tends to further improve the heat resistance of the anti-counterfeit laminate. Furthermore, the use of polyethylene naphthalate tends to further improve the adhesion between the transparent substrate and the thin wire.

[0034] The transparent substrate may be made of one material or may be a laminate of two or more materials. When the transparent substrate is a multilayer body made of two or more materials, the transparent substrate may be a laminate of organic or inorganic substrates, or a laminate of an organic substrate and an inorganic substrate.

[0035] The total light transmittance of the transparent substrate is preferably 50% or more, 60% or more, 70% or more, 80% or more, or 85% or more. A total light transmittance of 50% or more tends to further improve the reflected light intensity and improve the readability of the reflected light. In addition, the thickness when attached to the adherend is thin, and the design of the adherend is less likely to be impaired. The upper limit of the total light transmittance of the transparent substrate is not particularly limited, but may be 100% or less, or 99% or less. The total light transmittance can be measured in accordance with JIS K 7361-1:1997.

[0036] The thickness of the transparent substrate is preferably 5 to 500 μm, 7.5 to 250 μm, 10 to 100 μm, or 15 to 75 μm. When the thickness of the transparent substrate is 5 μm or more, the rigidity of the anti-counterfeit laminate is further improved, and minute deformation due to external factors such as lamination or expansion and contraction over time, as well as the accompanying scattering of light, are easily suppressed, which tends to further improve reading efficiency. Furthermore, when the thickness of the transparent substrate is 500 μm or less, light absorption and scattering by the transparent substrate are more easily suppressed, which tends to further improve reading efficiency. Furthermore, the thickness when laminated to an adherend is thin, which is less likely to impair the design of the adherend.

[0037] 1.2. Thin line pattern The thin line pattern is any pattern composed of thin lines, and may be a grid pattern (mesh pattern) of triangles, squares, hexagons, etc., or a line pattern. The thin lines are not limited to straight lines, but may be curved or wavy lines. The thin line pattern is preferably formed as a periodic pattern of thin lines. This allows the thin line pattern to form a diffraction grating, and by irradiating light, a diffraction image reflecting the fine structure can be obtained.

[0038] When a predetermined light is irradiated onto such a thin line pattern from an irradiation device, the thin line pattern reflects a predetermined reflected light. Here, the thin line pattern may act like a diffraction grating, and the reflected light may be diffracted light. For example, if the thin line pattern includes multiple thin lines with a line width of 5 μm or less, arranged at equal intervals with a periodic pitch of approximately several hundred μm, a diffraction image is observed in the reflected light, and the optical image includes such a diffraction image. In this case, the generated diffraction image may include a diffraction spot image or a diffraction stripe pattern.

[0039] Furthermore, if the fine line pattern is composed of multiple fine lines with a line width of 5 μm or less and arranged at equal intervals with a pitch of about several hundred μm, the individual fine lines are invisible and the fine line pattern is transparent, so that even if the anti-counterfeit laminate is attached to an adherend, the design and posted information are not impaired.

[0040] The thin wires may be made of a material having a total light transmittance of less than 50%. The thin wires may contain non-metallic materials, but are preferably thin wires containing metals. Examples of metals include, but are not limited to, gold, silver, copper, and aluminum. Among these, silver or copper is preferred, and copper is more preferred. Furthermore, the thin wires do not need to be electrically conductive, and the thin wire pattern does not need to ensure electrical conductivity at any two points on the pattern.

[0041] From the above viewpoints, it is preferable that the thin lines are difficult to see with the naked eye due to their thinness. For example, the line width of the thin lines is preferably 5.0 μm or less, 0.1 to 5.0 μm, or 0.3 to 5.0 μm. A line width of 5.0 μm or less reduces the visibility of the thin lines. This allows a thin line pattern to be applied without compromising the design of the adherend. Furthermore, such thin lines with low visibility are difficult to manufacture, and this also contributes to ensuring that they are difficult to replicate. Here, the line width in this embodiment refers to the line width of the thin lines when projected onto the surface of the transparent substrate from the side of the transparent substrate on which the thin lines are arranged.

[0042] The pitch between the fine lines in a predetermined direction is preferably 1.0 to 1000 μm, 5.0 to 500 μm, 50 to 250 μm, or 100 to 250 μm. When the pitch is 1.0 μm or more, the visibility of the fine lines decreases. This allows the fine line pattern to be applied without impairing the design of the adherend. Furthermore, when the pitch is 1000 μm or less, the influence of the fine line pattern is more easily reflected in the reflected light, which tends to further improve reading efficiency.

[0043] The aperture ratio, which is the ratio of the area of ​​the portion of the fine line pattern having no fine lines formed therein, of a predetermined area is preferably 80 to 99.9 area%, 85 to 99.8 area%, 90 to 99.6 area%, or 95 to 99.5 area%. The aperture ratio OR can also be expressed as transmittance. This prevents the fine line pattern from impairing the design of the adherend or the information displayed. When the fine line pattern has a mesh pattern shape, a fine line pattern with a line width of 1 μm and a pitch of 200 μm can achieve an aperture ratio of 99%.

[0044] The total light transmittance of the entire thin line pattern, including areas where thin lines are not formed, is preferably 75 to 99%, 80 to 98%, or 85 to 98%. The total light transmittance can be measured in accordance with JIS K 7361-1:1997.

[0045] 1.3. Adhesive layer The adhesive layer is used to attach the anti-counterfeit laminate to an adherend, and may be formed on one side of the transparent substrate so as to cover the fine line pattern. The adhesive layer is not particularly limited, but is preferably transparent and exhibits good adhesion to the conductive sheet or substrate. The adhesive layer may be a single layer or may have multiple layers.

[0046] The adhesive resin constituting such an adhesive layer is not particularly limited, but examples thereof include acrylic resins, urethane resins, polyisobutylene resins, olefin resins, acrylic urethane resins, and polyester resins.

[0047] The thickness of the adhesive layer is preferably 1.0 to 500 μm, 10 μm to 250 μm, or 25 to 150 μm. When the thickness of the adhesive layer is 5 μm or more, adhesion to the adherend tends to be further improved. Furthermore, when the thickness of the adhesive layer is 500 μm or less, light absorption and scattering by the transparent substrate is more easily suppressed, so reading efficiency tends to be further improved. Furthermore, the thickness when attached to the adherend is thin, so the design of the adherend is less likely to be impaired.

[0048] The haze of the adhesive layer is preferably greater than 50%, between 60 and 100%, and between 70 and 90%. When the haze of the adhesive layer is high, scattered light from the adherend is dispersed over a wide angle, reducing the effect of scattered light, which normally interferes with authentication as noise. Meanwhile, a portion of the diffraction image used for authenticity determination is reflected between the substrate and the metal mesh layer, allowing it to be used for authenticity determination without being affected by scattering from the high-haze layer. As a result, the intensity of noise light is relatively reduced, resulting in a clearer optical image (diffraction image), which tends to improve reading efficiency. Methods for improving haze include, but are not limited to, including light-scattering particles as components of the adhesive layer.

[0049] The haze of the adhesive layer is 50% or less, 0 to 40%, or 10 to 30%. The lower the haze of the adhesive layer, the less scattering there is in the adhesive layer, and the more the reading efficiency tends to improve. The haze of the adhesive layer can be measured in accordance with JISK7136.

[0050] 2. Manufacturing method of anti-counterfeit laminate The method for manufacturing the anti-counterfeit laminate of this embodiment includes a pattern formation step of forming a fine line pattern on a transparent substrate, and may also include an adhesive layer formation step of forming an adhesive layer on the substrate so as to cover the fine line pattern, as necessary.

[0051] The method for forming the fine line pattern in the pattern formation step is not particularly limited, and for example, the fine line pattern may be formed on the transparent substrate by various printing methods. More specifically, an ink containing metal particles may be printed on the transparent substrate by letterpress printing, gravure printing, bar coating printing, spray coating, spin coating, reverse transfer printing, or the like, and then baked to form the fine line pattern containing metal.

[0052] Furthermore, in the adhesive layer formation process, although not particularly limited, for example, an adhesive layer may be formed by applying a resin composition so as to cover the fine line pattern, or an adhesive layer may be formed by attaching double-sided tape so as to cover the fine line pattern.

[0053] 3. Anti-counterfeit laminate accessories The anti-counterfeit laminate accessory of this embodiment comprises an adherend and the above-mentioned anti-counterfeit laminate attached to the adherend. The adherend may be the product itself or the product packaging.

[0054] The surface of the adherend to which the anti-counterfeit laminate is attached may be a surface such that 99% or more of the reflected light corresponding to light incident perpendicularly to the surface has a reflection angle of 0.30 degrees or less. This tends to further improve the reading efficiency of the reflected light. The reflection angle is preferably 0.25 degrees or less, 0.20 degrees or less, 0.15 degrees or less, or 0.10 degrees or less. The lower limit of the reflection angle is not particularly limited, but may be 0.01 degrees or more, 0.02 degrees or more, or 0.03 degrees or more.

[0055] 4. Manufacturing method of anti-counterfeit laminate accessory The method for producing an anti-counterfeit laminate accessory of this embodiment includes a step of attaching the anti-counterfeit laminate to an adherend. In this case, it is preferable that the surface of the adherend to which the anti-counterfeit laminate is attached is a surface such that, of the reflected light corresponding to light perpendicularly incident on the surface, 99% or more of the reflected light has a reflection angle of 0.30 degrees or less.

[0056] The method of attachment in the attachment step is not particularly limited, but examples include a method in which the anti-counterfeit laminate is attached to the adherend via an adhesive layer of the anti-counterfeit laminate. [Example]

[0057] The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0058] Example 1 20 parts by mass of cuprous oxide nanoparticles with a primary particle size of 21 nm, 4 parts by mass of a dispersant (manufactured by BYK-Chemie, product name: Disperbyk-145), 1 part by mass of a surfactant (manufactured by AGC Seimi Chemical Co., Ltd., product name: S-611), and 75 parts by mass of ethanol were mixed to prepare an ink containing 20% ​​by mass of cuprous oxide nanoparticles.

[0059] Cosmoshine (manufactured by Toyobo Co., Ltd., product name: A4160, single-sided easy-adhesion type, thickness: 50 μm, total light transmittance: 89.3%) was used as a transparent substrate, and the ink prepared as described above was printed in the desired fine line pattern on its easy-adhesion surface. Specifically, the ink was first applied to the surface of a blanket, and then the ink-coated blanket surface was brought into contact with a plate having grooves for the fine line pattern, transferring some of the ink on the blanket surface to the raised surfaces of the plate. Thereafter, the blanket surface coated with the remaining ink was brought into contact with the substrate, and the ink in the fine line pattern was transferred onto the substrate. Note that the line width of the fine line pattern was 3 μm and the pitch was 60 μm.

[0060] Plasma was generated from the fine line pattern ink obtained as described above using microwaves generated at an output of 0.9 kW in an atmosphere under reduced pressure with a water molecule partial pressure of 100 Pa, and the plasma was reacted with the ink for 180 seconds to form a fine line pattern consisting of fine metal lines.

[0061] One release film of a substrateless adhesive tape 1 (manufactured by Lintec Corporation, product name: MO-T015, thickness 25 μm, total light transmittance 99% or more, haze 0.4%) was peeled off and the adhesive surface was attached facing the fine line pattern formed as described above at 20°C, and a roller was moved back and forth twice from above with a pressure of 2 N to form an adhesive layer, thereby obtaining an anti-counterfeiting laminate.

[0062] Comparative Example 1 An anti-counterfeit laminate was obtained in the same manner as in Example 1, except that adhesive tape 2 (manufactured by Lintec Corporation, product name: Non-Carrier PET38 PAT1 8K, thickness 20 μm) was used instead of adhesive tape 1.

[0063] [Reflection angle measurement] Using a scanning laser microscope (LEXT OLS-4500, manufactured by Olympus Corporation), the surface shape of the transparent substrate side of the adherend was obtained for each of the anti-counterfeit laminates obtained as described above, and the reflection angle was determined from there. In the case where the anti-counterfeit laminate had no adherend, the release film of the adhesive layer of the anti-counterfeit laminate was peeled off, and the anti-counterfeit laminate was placed with the adhesive layer facing upward, and the surface shape of the adhesive layer side was obtained.

[0064] In order to detect the shape of the adhesive surface more accurately, a thin Au film was deposited on the adhesive surface using a sputtering device (DII-29010SCTR Smart Coater). The size of the sample surface observed with the laser microscope was approximately 2.6 mm square, and the surface shape was obtained as xyz coordinate data by dividing the observation range into 1024 x 1024.

[0065] A low-pass filter was applied to the obtained xyz coordinate data as a preprocessing step to remove measurement noise. The low-pass filter was applied in the frequency domain, with the cutoff frequency set to 0.15 times the maximum frequency. After applying the filter, the gradient of the xyz coordinate data was calculated from the difference with adjacent points, and a normal vector of magnitude 1 relative to the surface at each point was obtained.

[0066] The average value of the x and y components of the normal vector of each point was set as the center of the distribution, and the distance between the x and y components of the normal vector of each point and the center of the distribution was calculated. This distance distribution was converted into an angle using an arc sine function, and the angle range in which the proportion of reflected light relative to perpendicular incident light was 50%, 80%, 90%, and 99% was determined as the reflection angle R. xx (xx is the proportion of contained reflected light) The results are shown in Table 1.

[0067] [Reading efficiency] When attempting to obtain diffracted light from each of the anti-counterfeit laminates produced in the Examples and Comparative Examples, if the diffracted light obtained was blurred or otherwise unreadable three or more times out of ten, it was marked with an X, and if the diffracted light obtained was unreadable two or less times out of ten, it was marked with an O.

[0068] [Table 1]

[0069] Furthermore, the anti-counterfeit laminate of Example 1 and the anti-counterfeit laminate of Comparative Example 1 were bonded to cast paper and coated cardboard, respectively, and the reading efficiency test was carried out. As a result, when the anti-counterfeit laminate of Example 1 was used, better results were obtained when it was bonded to either adherend, compared to when the anti-counterfeit laminate of Comparative Example 1 was used. This shows that when the surface state of the adherend is evaluated under the same conditions, the anti-counterfeit laminate of Example 1 produces superior results. [Industrial Applicability]

[0070] The present invention has industrial applicability as a counterfeit prevention laminate that can be attached to an adherend and used as a seal, tag, or the like to prevent counterfeiting. [Explanation of symbols]

[0071] 10...transparent substrate, 10a...surface, 10b...surface, 20...thin line pattern, 30...adhesive layer, 100...counterfeit prevention laminate, 200...authenticity determination device, 210...irradiation device, 220...light receiving device, 230...determination unit, 300...adherend

Claims

1. A transparent substrate; a thin line pattern formed on one surface of the transparent substrate; Of the reflected light corresponding to light that is incident perpendicularly to the thin line pattern from the other surface of the transparent substrate, a reflection angle R of 99% or more of the reflected light 99 is 0.30 degrees or less, Anti-counterfeit laminate.

2. The reflection angle R of 90% or more of the reflected light 90 is 0.25 degrees or less, The counterfeit prevention laminate according to claim 1.

3. The reflection angle R 99 The reflection angle R of 80% or more of the reflected light 80 The ratio (R 80 / R 99 ) is 0.27 or more; The counterfeit prevention laminate according to claim 1.

4. The total light transmittance of the transparent substrate is 50% or more. The counterfeit prevention laminate according to claim 1.

5. The thickness of the transparent substrate is 10 to 100 μm. The counterfeit prevention laminate according to claim 1.

6. an adhesive layer covering the thin line pattern on one surface of the transparent substrate; The haze of the adhesive layer is greater than 50%. The counterfeit prevention laminate according to claim 1.

7. an adhesive layer covering the thin line pattern on one surface of the transparent substrate; The haze of the adhesive layer is 50% or less. The counterfeit prevention laminate according to claim 1.

8. An adherend; The anti-counterfeit laminate according to any one of claims 1 to 7 attached to the adherend, Anti-counterfeit laminate accessories.

9. the surface of the adherend to which the anti-counterfeit laminate is attached is a surface in which 99% or more of the reflected light corresponding to light incident perpendicularly to the surface has a reflection angle of 0.30 degrees or less; The anti-counterfeit laminate accessory according to claim 8.

10. An adhesion step of adhering the counterfeit prevention laminate according to any one of claims 1 to 7 to an adherend, the surface of the adherend to which the anti-counterfeit laminate is attached is a surface in which 99% or more of the reflected light corresponding to light incident perpendicularly to the surface has a reflection angle of 0.30 degrees or less; Method for manufacturing anti-counterfeit laminate accessories.

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