Laminate, certificate, and method for manufacturing laminate

Abstract

To provide a laminate, a certificate, and a method for manufacturing a laminate which make it possible to prevent re-use of a security foil included in the laminate.SOLUTION: A laminate 10 comprises: a recording layer 11; a translucent front side coating layer 12; and a security foil 20 which is laminated by the recording layer 11 and the front side coating layer 12, and encapsulated in the laminate 10. The thickness of the security foil 20 is 1 / 5 or less the thickness of the recording layer 11. The security foil 20 is equipped with a relief layer 21 having a relief surface 21R and a protective layer 22 covering the relief surface 21R, and the protective layer 22 is adhered to the recording layer 11, and the relief layer 21 is adhered to the front side coating layer 12 in a thickness direction. The adhesive strength between the security foil 20 and the recording layer 11 is higher than the adhesive strength between the security foil 20 and the front side coating layer 12.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present disclosure relates to a laminate, a certificate including the laminate, and a method for manufacturing the laminate. [Background technology]

[0002] For certificates on which authentication information is recorded, such as ID cards, passports, and driver's licenses, a structure is known in which a security foil including a relief structure is sandwiched between two layers and located inside the outer edges of each layer. With such certificates, the security foil is less likely to suffer at least one of chemical and physical damage, and is less likely to be separated from other members constituting the certificate, compared to a structure in which the security foil is located on the outer surface of the certificate (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6107137 specification Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, certificates of the same type often use security foils that display the same image. In such certificates, when the security foil is removed from a genuine certificate, the removed security foil can be reused to manufacture a fake certificate that contains altered authentication information. When the authentication of a fake certificate is determined based on the reused security foil, it is difficult to distinguish the fake certificate because the security foil itself is derived from the genuine certificate. Therefore, there is a demand for a certificate whose security foil is difficult to reuse.

[0005] It should be noted that these points are not limited to certificates containing authentication information, but are also common to laminates that contain security foils but also contain information other than authentication information. An object of the present disclosure is to provide a laminate, a certificate, and a method for manufacturing a laminate that make it possible to prevent reuse of a security foil provided in the laminate. [Means for solving the problem]

[0006] A laminate for solving the above problems includes a recording layer, a light-transmitting front-side covering layer, and a security foil laminated with the recording layer and the front-side covering layer, the thickness of which enclosed within the laminate is 1 / 5 or less of the thickness of the recording layer. The security foil includes a relief layer having a relief surface and a protective layer covering the relief surface, and the protective layer is adhered to the recording layer in the thickness direction, and the relief layer is adhered to the front-side covering layer. The adhesive strength between the security foil and the recording layer is higher than the adhesive strength between the security foil and the front-side covering layer.

[0007] A certificate for solving the above problem includes the above laminate and a support layer that supports the laminate. A method for manufacturing a laminate for solving the above problems includes preparing a recording layer and a surface-side covering layer, sealing a security foil having a thickness of 1 / 5 or less of the thickness of the recording layer, the security foil including a relief layer having a relief surface and a protective layer covering the relief surface, with the recording layer and the surface-side covering layer so as to be located inside the outer edge of the recording layer and the outer edge of the surface-side covering layer, and forming a laminate in which the security foil is sealed by the recording layer and the surface-side covering layer by applying heat and pressure to the recording layer, the surface-side covering layer, and the security foil with the security foil disposed between the recording layer and the surface-side covering layer. The adhesive strength between the security foil and the recording layer is higher than the adhesive strength between the security foil and the surface-side covering layer.

[0008] According to the above configuration, when the security foil is removed from the laminate, the recording layer and the front-side covering layer are first separated. At this time, since the adhesive strength between the security foil and the recording layer is higher than that between the security foil and the front-side covering layer, the security foil remains on the recording layer. In order to reuse the security foil, it is necessary to separate the security foil from the recording layer. In a security foil having a thickness of 1 / 5 or less than that of the recording layer, the security foil is more likely to be destroyed when the security foil is peeled off, compared to a structure in which the thickness of the security foil is thicker than 1 / 5 of the thickness of the recording layer, for example, a structure in which the thickness of the security foil is approximately the same as that of the recording layer. Therefore, it is difficult to peel the security foil from the recording layer without destroying the security foil. Therefore, it is difficult to manufacture a fake laminate by reusing the security foil provided in the laminate.

[0009] In the laminate, the recording layer may have an irradiated area in a region covered by the security foil when viewed in a thickness direction of the laminate. With the above configuration, the irradiated area can be visually recognized together with the optical effect of the security foil.

[0010] In the laminate, the recording layer may include polycarbonate, and the protective layer may include a resin having a carbonate bond, a urethane bond, or an ester bond. With the above configuration, it is easy to increase the adhesive strength between the recording layer and the protective layer.

[0011] In the laminate, the recording layer and the surface-side covering layer may contain polycarbonate, the protective layer may contain a first resin having a melting point lower than that of the polycarbonate, and the relief layer may contain a second resin having a melting point higher than that of the polycarbonate. According to the above configuration, it is possible to increase the adhesive strength between the protective layer and the recording layer and to decrease the adhesive strength between the relief layer and the surface-side covering layer.

[0012] In the above laminate, the relief layer may contain at least one of a first group of substances consisting of polymethyl methacrylate, cyclic polyolefin, and melamine, the protective layer may contain at least one of a second group of substances consisting of polyurethane, polymethyl acrylate, polyester, acid-modified polyolefin, and ethylene-vinyl acetate copolymer resin, and each of the recording layer and the surface side coating layer may contain at least one of a third group of substances consisting of polycarbonate, amorphous copolyester, and polyvinyl chloride.

[0013] According to the above configuration, the adhesive strength of each material of the first substance group to each material of the third substance group is relatively high, while the adhesive strength of each material of the second substance group to each material of the third substance group is relatively low. Therefore, by having the relief layer contain at least one substance of the first substance group and the protective layer contain at least one substance of the second substance group, it is easy to realize a configuration in which the adhesive strength between the security foil and the recording layer is higher than the adhesive strength between the security foil and the front side coating layer.

[0014] In the above laminate, the relief surface may have at least one of the following characteristics: a characteristic of diffracting incident light incident on the relief surface; a characteristic of suppressing reflection of the incident light; a characteristic of isotropically reflecting the incident light; a characteristic of anisotropically reflecting the incident light; a characteristic of concentrating the incident light; and a characteristic of reflecting a specific polarization contained in the incident light.

[0015] According to the above-mentioned configuration, since the relief structure has specific optical properties with respect to incident light, it is difficult to counterfeit the security foil, which makes it difficult to counterfeit a laminate including the security foil, and as a result, counterfeiting of the laminate can be suppressed.

[0016] In the laminate, the front cover layer may transmit a part or all of the wavelengths of infrared rays, and the security foil may transmit the part or all of the wavelengths of infrared rays. According to the above configuration, an irradiated area can be formed in the recording layer via the front cover layer and the security foil. That is, an irradiated area can be formed in the area covered by the security foil when viewed from the thickness direction of the recording layer. Effect of the Invention

[0017] According to the present disclosure, the reuse of the security foil provided in the laminate is reduced. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a plan view illustrating a structure of a laminate according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view illustrating the structure of the laminate taken along line II in FIG. [Diagram 3] FIG. 11 is a cross-sectional view illustrating the structure of another laminate. [Figure 4] FIG. 2 is an operational diagram illustrating a state in which the laminated body of FIG. 1 is separated. [Diagram 5] FIG. 2 is a plan view illustrating a structure of a certificate according to an embodiment. [Figure 6] 6 is a cross-sectional view illustrating the structure of the certificate taken along line II-II in FIG. 5. [Figure 7] FIG. 2 is a process diagram illustrating one step included in a method for producing the laminate of FIG. [Figure 8] FIG. 2 is a process diagram illustrating one step included in a method for producing the laminate of FIG. [Figure 9] FIG. 2 is a process diagram illustrating one step included in a method for producing the laminate of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The laminate, the certificate, and the manufacturing method of the laminate will be described with reference to Figures 1 to 9. Below, the structure of the laminate, the function of the laminate, the structure of the certificate, the material of each layer in the certificate, the manufacturing method of the laminate, and the experimental results will be described in order.

[0020] It should be noted that the present embodiment is intended to explain the gist of the invention, and should not be interpreted as limiting the following embodiment. It should be understood that the present embodiment is representative of the present invention. Those skilled in the art can appropriately modify the design of the representative embodiment described below.

[0021] In addition, the drawings are illustrative, and the dimensions shown therein may differ from the actual ones, for example, the thickness of each layer and its ratio, and the dimensional ratios in the drawings should not be interpreted as being limited to the ratios shown therein. In addition, unless there is a reason for convenience, the same symbols are used to describe similar configurations in each embodiment, and duplicated descriptions are omitted. The embodiments of the present disclosure are a group of embodiments based on a unique single invention from the background. In addition, each aspect of the present disclosure is an aspect of a group of embodiments based on a single invention. Each configuration of the present disclosure may have each aspect of the present disclosure. Each feature of the present disclosure can be combined to form each configuration. Therefore, each feature of the present disclosure, each configuration of the present disclosure, each aspect of the present disclosure, and each embodiment of the present disclosure can be combined, and the combination has a synergistic function and can exhibit a synergistic effect.

[0022] [Laminate structure] The structure of the laminate will be described with reference to FIGS. As shown in Fig. 1, the laminate 10 is in the form of a sheet. In the configuration of Fig. 1, the contour shape of the laminate 10 is a rectangle with rounded corners, but the outer shape of the laminate 10 may be a circle, an ellipse, or the like other than a rectangle. When the laminate 10 is in the form of a sheet and has a contour shape of a rectangle with rounded corners, the laminate 10 is in the form of a card.

[0023] The laminate 10 includes a security foil 20 located inside the outer edge of the laminate 10 in a plan view facing the surface 10F. The security foil 20 records authentication information. The security foil 20 may have an elliptical outer shape, or may have a rectangular or circular outer shape other than an elliptical outer shape. The security foil 20 has a relief surface, and the relief surface can reflect light incident on the relief surface. The relief surface can record authentication information. The reflected light of the relief surface presents a first image PIC1 as the authentication information. The first image PIC1 is displayed by the reflected light of the relief surface. The security foil 20 displays the first image PIC1 as the authentication information. In FIG. 1, the first image PIC1 is a star shape. The type of the first image PIC1 displayed by the security foil 20 can be a geometric pattern, a letter, a number, a sign, a symbol, an emblem, a coat of arms, or a code, or a combination thereof. Symbols and emblems can include flags, shields, swords, spears, crowns, stars, moons, hearts, logos, ribbons, lines, flowers, leaves, grains, fruits, birds, wings, fish, arthropods, mammals, mythical creatures, reptiles, amphibians. The code can be a one-dimensional code, a two-dimensional code. The one-dimensional code can be a barcode, a serial number or a combination of both. The two-dimensional code can be a QR code. The geometric pattern can be a Guilloche.

[0024] The security foil 20 may transmit a portion of the infrared wavelength band or the entire infrared wavelength band. The transmitted infrared wavelength band may include the wavelengths of an infrared laser. In particular, the transmitted infrared wavelength band may include wavelengths between 900 nm and 1100 nm. This allows the transmission of a YAG laser beam. In this case, an infrared laser beam can be irradiated onto the recording layer (described later) through the security foil 20 to form an irradiated area in the recording layer. The recording layer is the same as the color-developing layer described in the application claiming priority of the present application.

[0025] The laminate 10 can further display a second image PIC2 through the surface 10F. The second image PIC2 can be recorded as an illuminated area formed in a recording layer, which will be described later. The possible types of the second image PIC2 can be the same as the possible types of the first image PIC1. The second image PIC2 can have the same type of shape as the first image PIC1. The second image PIC2 can also surround the security foil 20. The second image PIC2 can have a shape coupled to the first image PIC1. The second image PIC2 can be a collection of multiple segments. In FIG. 1, the second image PIC2 is an ellipse surrounding the first image PIC1.

[0026] Fig. 2 shows a cross-sectional structure of the laminate 10 taken along line II in Fig. 1. In Fig. 2, for the convenience of explaining the structure of the security foil 20, the thickness of each layer included in the security foil 20 is exaggerated.

[0027] As shown in FIG. 2, the laminate 10 includes a recording layer 11, a light-transmitting front-side covering layer 12, and a security foil 20. The security foil 20 is laminated with the recording layer 11 and the front-side covering layer 12, and the security foil 20 is enclosed between the recording layer 11 and the front-side covering layer 12 so that the security foil 20 is not exposed to the outside of the laminate 10. The security foil 20 includes a relief layer 21 having a relief surface 21R. The thickness T20 of the security foil 20 is 1 / 5 or less of the thickness T11 of the recording layer 11. The thickness T20 of the security foil 20 may be 1 / 200 or more of the thickness T11 of the recording layer 11. In the laminate 10, the adhesive strength between the security foil 20 and the recording layer 11 is higher than the adhesive strength between the security foil 20 and the front-side covering layer 12. The adhesive strength can be measured by a method conforming to the 90-degree peel test method specified by JIS K 6854-1 (ISO 8510-1).

[0028] The relief surface 21R may have at least one of the following properties: (a) Diffraction characteristics of incident light on the relief surface 21R (b) The characteristic of suppressing reflection of incident light on the relief surface 21R (c) The characteristic of isotropically reflecting incident light incident on the relief surface 21R (d) The characteristic of anisotropically reflecting incident light incident on the relief surface 21R (e) The characteristic of focusing the incident light on the relief surface 21R (f) The characteristic of reflecting a specific polarized light contained in the incident light incident on the relief surface 21R.

[0029] The relief structure has a concave-convex shape even when it has any of the above-mentioned characteristics. In other words, the relief surface 21R is a concave-convex surface. One relief surface 21R can have at least one of the above-mentioned characteristics by including at least one relief structure having the above-mentioned mutually different characteristics. When a plane parallel to the surface 21F of the relief layer 21 is set as a reference plane, the difference between the maximum value and the minimum value of the height in the relief structure can be 0.1 μm or more and 10 μm or less. In addition, in the relief structure, the interval at which the recesses are located or the interval at which the protrusions are located can be 0.1 μm or more and 20 μm or less. The relief layer 21 may transmit a part or all of the wavelengths of infrared rays. The transmitted infrared ray band can include the wavelength of an infrared laser. In particular, the transmitted infrared ray band can include the wavelength of 900 nm or more and 1100 nm or less. This allows the light beam of a YAG laser to be transmitted. In this case, an infrared laser beam is irradiated onto the recording layer 11 through the security foil 20, thereby forming the irradiated area 11a in the recording layer 11. The laser that irradiates the recording layer 11 with the laser beam to form the irradiated area 11a can be a pulsed laser. The pulsed laser can modulate the pulse interval and the energy of one pulse. This allows the irradiated area 11a to be formed on the recording layer 11 with the laser beam of the pulsed laser in accordance with the material of the recording layer 11. The laser can also be an infrared laser with an infrared wavelength. The infrared pulsed laser can be a YAG laser.

[0030] The security foil 20 further includes a protective layer 22 covering the relief surface 21R. The security foil 20 includes a pair of surfaces facing each other in the thickness direction of the security foil 20. The relief layer 21 has a relief surface 21R and a front surface 21F that is the surface opposite to the relief surface 21R. The protective layer 22 has a back surface 22R that is the surface opposite to the surface in contact with the relief surface 21R. The pair of surfaces includes a first surface and a second surface. The back surface 22R of the protective layer 22 can be the first surface in contact with the recording layer 11. The front surface 21F of the relief layer 21 can be the second surface in contact with the front-side covering layer 12. The protective layer 22 may also transmit a part or all of the wavelengths of infrared rays. The transmitted infrared band can include the wavelength of an infrared laser. In particular, the transmitted infrared band can include wavelengths of 900 nm or more and 1100 nm or less. This allows the light beam of a YAG laser to pass through. In this case, an infrared laser beam can be irradiated onto the recording layer 11 through the security foil 20 to form an irradiated area 11 a on the recording layer 11 .

[0031] The relief layer 21 may include at least one substance from a first group of substances consisting of polymethylmethacrylate, cyclic polyolefins, and melamine. The material of the protective layer 22 may include at least one substance from a second group of substances consisting of polyurethane, polymethylacrylate, polyester, acid-modified polyolefins, and ethylene-vinyl acetate copolymer resins.

[0032] The security foil 20 may further comprise a reflective layer 23. The reflective layer 23 covers the relief surface 21R. The reflective layer 23 may be opaque or translucent. The opaque reflective layer 23 may be a metallic reflective layer. The translucent reflective layer 23 may be a dielectric reflective layer. The refractive index of the dielectric of the reflective layer 23 in visible light may be 2.0 or more. When the refractive index is 2.0 or more, it is easy to obtain a refractive index difference with the relief layer 21. In the security foil 20, the relief structure included in the relief surface 21R comprises the reflective layer 23, so that the reflectance can be improved in at least one of the above-mentioned characteristics (a), (c), (d), (e), and (f). Therefore, the reflected light from the relief surface 21R is easily visible to an observer of the laminate 10. The reflective layer 23 may also transmit a part or all of the wavelengths of infrared light so as to transmit infrared laser light. The band of infrared rays that transmit can include the wavelength of an infrared laser. In particular, the band of infrared rays that transmit can include wavelengths of 900 nm or more and 1100 nm or less. This allows the YAG laser beam to transmit. In this case, an infrared laser beam can be irradiated onto the recording layer 11 through the security foil 20, forming an irradiated area 11a on the recording layer 11.

[0033] The relief surface 21R may include a diffraction grating as a relief structure, which has the property of diffracting light incident on the relief surface 21R. The security foil 20 forms the above-mentioned first image PIC1 by the diffracted light reflected by the relief surface 21R.

[0034] As described above, the security foil 20 is located inside the outer edge of the recording layer 11 and the outer edge of the front-side covering layer 12 in a plan view facing the front surface 10F. In each of the recording layer 11 and the front-side covering layer 12, the portions protruding outside the security foil 20 in a plan view facing the front surface 10F are bonded to each other. That is, the laminate 10 encapsulates the security foil 20 by the recording layer 11 and the front-side covering layer 12. In addition, the security foil 20 and the recording layer 11 are bonded to each other. The security foil 20 and the front-side covering layer 12 are bonded to each other. More specifically, the relief layer 21 and the front-side covering layer 12 of the security foil 20 are bonded to each other. The protective layer 22 and the front-side covering layer 12 of the security foil 20 are bonded to each other.

[0035] The entire or part of the recording layer 11 is modified by irradiation with a laser beam. The recording layer 11 modified by irradiation with a laser beam becomes an irradiated region 11a. Therefore, by irradiating the recording layer 11 with a laser beam, an irradiated region 11a is formed, and information can be recorded in the recording layer 11. The recording layer 11 can be composed of an irradiated region 11a and an unirradiated region 11b. The irradiated region 11a is a region in which the recording layer 11 is modified by irradiation with a laser beam. The unirradiated region 11b is a region that is not irradiated with a laser beam. The laminate 10 can record information by the irradiated region 11a.

[0036] The information recorded in the laminate 10 may be identification information. The identification information may be individual information that is different for each laminate. The identification information may be personal authentication information that can be used to authenticate an individual. The personal authentication information may include at least one of biometric information and non-biometric information.

[0037] Biometric information is a feature of a living body that is unique to an individual to be authenticated, and is an image or pattern such as a portrait, a fingerprint, veins, and a signature. Biometric information can be identifiable biometric information. Non-biometric information is personal information other than biometric information. Personal information other than biometric information includes name, date of birth, age, blood type, sex, nationality, address, affiliation, and signature. Non-biometric information can be a plurality of letters, a plurality of numbers, a symbol, a figure, or handwriting. Non-biometric information can be digital data. Digital data can be recorded as codes. These can be either encrypted or plain text, or both.

[0038] As shown in FIG. 3, the irradiated area 11a may be formed in the area overlapping the security foil 20 when viewed from the thickness direction of the laminate 10. In this case, the irradiated area 11a overlaps a part of the security foil 20, and the non-irradiated area 11b overlaps another part of the security foil 20. Identification information or identifiable biometric information may be recorded in the irradiated area 11a overlapping the security foil 20. The identifiable biometric information may be personal authentication information including biometric information. By recording the identification information or identifiable biometric information in the irradiated area 11a overlapping the security foil 20, it is possible to prevent tampering with the identification information or identifiable biometric information. The identification information or identifiable biometric information may be configured as a pair of an area overlapping the security foil 20 and an area not overlapping the security foil 20. In other words, it may be configured as a pair of a part of the identification information or identifiable biometric information recorded as the irradiated area 11a overlapping the security foil 20 and a part of the identification information or identifiable biometric information recorded as the irradiated area 11a not overlapping the security foil 20. In this case, a part of the identification information or identifiable biometric information recorded in the irradiated area 11a overlapping with the security foil 20 is complemented by a part of the identification information or identifiable biometric information recorded in the irradiated area 11a not overlapping with the security foil 20. In addition, the adhesive strength between the irradiated area 11a and the security foil 20 may be lower than the adhesive strength between the unirradiated area 11b and the security foil 20.

[0039] When the irradiated region 11a is irradiated with a laser beam, the protective layer 22 is also irradiated with the laser beam at a portion in contact with the irradiated region 11a. As a result, a low adhesion region 22a is formed in the protective layer 22, which is a portion irradiated with the laser beam. The protective layer 22 is formed of the low adhesion region 22a and the high adhesion region 22b that is not irradiated with the laser beam. In the low adhesion region 22a, a part of the protective layer 22 is denatured by the laser beam. The high adhesion region 22b of the protective layer 22 may contain a crystalline resin, and the low adhesion region 22a may be formed by amorphizing the crystalline resin of the protective layer 22. The high adhesion region 22b of the protective layer 22 contains a crystalline resin, while the low adhesion region 22a is formed by amorphizing the crystalline resin of the protective layer 22 by irradiation with a laser beam, so that the adhesive strength of the high adhesion region 22b to the recording layer 11 can be made equal to or greater than the adhesive strength of the low adhesion region 22a. In other words, the adhesive strength of the low adhesive area 22a to the recording layer 11 is lower than that of the high adhesive area 22b. In this manner, the protective layer 22 may contain a crystalline resin. The crystalline resin of the protective layer 22 may be a crystalline polyester.

[0040] Also, the adhesive strength between the irradiated area 11a of the recording layer 11 and the low adhesion area 22a of the security foil 20 may be lower than the adhesive strength between the security foil 20 and the front-side covering layer 12. In this case, when the front-side covering layer 12 is peeled off, the part of the security foil 20 that is in contact with the non-irradiated area 11b remains in the recording layer 11. Also, the irradiated area 11a remains in the front-side covering layer 12, that is, it is peeled off together with the front-side covering layer 12. Therefore, the security foil 20 is destroyed. This makes it possible to prevent the security foil 20 from being reused. Also, the area of ​​the security foil 20 that corresponds to the irradiated area 11a of the recording layer 11 may become an altered part. In this case, the information of the irradiated area 11a is also recorded in the security foil 20, making it possible to prevent the security foil 20 from being diverted.

[0041] The irradiated region 11a is modified. The modification may be carbonization of the irradiated region 11a. The modification may be foaming of the irradiated region 11a. The irradiated region 11a may be colored by the modification. The coloring may be black. The color of the irradiated region 11a may be a color other than black, and the color of the irradiated region 11a may be white and opal. In the recording layer 11, the non-irradiated region 11b may be translucent to transmit visible light. In contrast, the irradiated region 11a may not transmit visible light, or may be capable of transmitting a part of visible light. The irradiated region 11a may be opaque. The transmittance of the non-irradiated region 11b may be higher than that of the irradiated region 11a. The second image PIC2 described above is an image of the irradiated region 11a. The thickness of the recording layer 11 may be 50 μm or more and 800 μm or less.

[0042] The surface-side covering layer 12 can be translucent to transmit visible light. The surface-side covering layer 12 can also transmit light of wavelengths in a part of the infrared ray band or in the entire infrared ray band. The surface of the surface-side covering layer 12 opposite to the surface in contact with the recording layer 11 is the surface 10F of the laminate 10. Due to the translucency of the surface-side covering layer 12, the laminate 10 can display each image through the surface 10F. By transmitting light of wavelengths in a part of the infrared ray band or in the entire infrared ray band through the surface-side covering layer 12, an irradiated region 11a can be formed in the recording layer 11 by an infrared laser beam through the surface-side covering layer 12. The thickness of the surface-side covering layer 12 can be 50 μm or more and 800 μm or less.

[0043] If the front-side covering layer 12 and the security foil 20 are configured to transmit infrared rays, the recording layer 11 can have an irradiated area 11a in the area of ​​the recording layer 11 covered by the security foil 20 when viewed in the thickness direction of the recording layer 11. By covering the irradiated area 11a with the security foil 20, it is possible to prevent tampering with the information recorded in the irradiated area 11a. In other words, if an attempt is made to tamper with the information in the irradiated area 11a by peeling the security foil 20 from the recording layer 11 and re-forming the irradiated area 11a, the security foil 20 will be broken because it is firmly adhered to the recording layer 11. As a result, it is possible to prevent tampering with the laminate 10 by rewriting the irradiated area 11a and re-attaching the security foil 20.

[0044] Each of the recording layer 11 and the front side covering layer 12 can contain at least one substance from a third substance group consisting of polycarbonate, amorphous copolyester, and polyvinyl chloride. The adhesive strength of each material from the first substance group to each material from the third substance group is relatively high, while the adhesive strength of each material from the second substance group to each material from the third substance group is relatively low. Therefore, by the relief layer 21 containing at least one substance from the first substance group and the protective layer 22 containing at least one substance from the second substance group, it is easy to realize a structure in which the adhesive strength between the security foil 20 and the recording layer 11 is higher than the adhesive strength between the security foil 20 and the front side covering layer 12.

[0045] As described above, the thickness of the security foil 20 is ⅕ or less of the thickness of the recording layer 11. Since the security foil 20 is very thin compared to the recording layer 11, the area where the side surface of the security foil 20 contacts the recording layer 11 is negligibly small compared to the area where the back surface 22R of the protective layer 22 contacts the recording layer 11. Therefore, the surface of the security foil 20 that contacts the recording layer 11 may be considered to be only the back surface 22R of the protective layer 22. Note that these matters can also be applied to the relationship between the front surface 21F of the relief layer 21 and the front-side covering layer 12.

[0046] [Function of laminate] The state in which the laminate is separated will be described with reference to FIG. As shown in FIG. 4, when the security foil 20 is removed from the laminate 10, the recording layer 11 and the front-side covering layer 12 are first separated. At this time, if the adhesive strength between the security foil 20 and the recording layer 11 is higher than the adhesive strength between the security foil 20 and the front-side covering layer 12, the security foil 20 remains on the recording layer 11 side. In order to reuse the security foil 20, it is necessary to separate the security foil 20 from the recording layer 11. However, since the thickness T20 of the security foil 20 is 1 / 5 or less of the thickness T11 of the recording layer 11, it is difficult to peel the security foil 20 from the recording layer 11 without destroying the security foil 20, compared to a configuration in which the thickness T20 of the security foil 20 is approximately the same as the thickness T11 of the recording layer 11. Therefore, it is difficult to reuse the security foil 20 provided in the laminate 10. Therefore, it is difficult to manufacture a fake laminate using the security foil 20. Furthermore, by making the thickness T20 of the security foil 20 1 / 5 or less of the thickness T11 of the recording layer 11, the laser beam can easily pass through the security foil 20, while the laser beam can easily be absorbed by the recording layer 11. Also, by making the thickness T20 of the security foil 20 1 / 200 or more of the thickness T11 of the recording layer 11, processability is improved. Also, when the thickness of the recording layer 11 is thinner than five times the thickness of the security foil 20, the recording layer 11 can be scraped off and the security foil 20 can be easily removed.

[0047] The thickness of the recording layer 11 can be 50 μm or more and 800 μm or less. In addition, the difference between the maximum value and the minimum value of the height in the relief structure can be 0.1 μm or more and 10 μm or less, and the interval at which the concave portions are located or the interval at which the convex portions are located can be 0.1 μm or more and 20 μm or less. By making the thickness of the security foil 20 1 / 5 or less of the thickness of the recording layer 11, it becomes difficult to peel the security foil 20 from the recording layer 11 without destroying the relief surface 21R included in the security foil 20. Therefore, it is possible to increase the probability that the peeled security foil 20 includes a relief surface 21R having optical properties different from that of the genuine security foil 20. As a result, a fake laminate using the peeled security foil 20 is easily identified as a fake of the genuine laminate 10.

[0048] [Certificate structure] The structure of a certificate including the above-mentioned laminate 10 will be described with reference to Fig. 5 and Fig. 6. An example in which the certificate is embodied as an identification card will be described below. In Fig. 6, the thickness of each layer of the certificate is exaggerated for the convenience of explaining the configuration of the certificate. The certificate may be an identification card, an ID card, a passport, a visa, or the like.

[0049] As shown in Fig. 5, certificate 30 includes a front surface 30F. In a plan view facing front surface 30F, certificate 30 has a card-like shape. In Fig. 5, information on a first image PIC1, information on a third image PIC3, information on a fourth image PIC4, and information on a fifth image PIC5 are recorded on certificate 30. Certificate 30 can display first image PIC1, third image PIC3, fourth image PIC4, and fifth image PIC5 through front surface 30F. In other words, first image PIC1, third image PIC3, and fourth image PIC4 can be visible images.

[0050] The third image PIC3 forms a text indicating the type of the certificate 30. The fourth image PIC4 forms a portrait of the owner of the certificate 30. The fourth image PIC4 can be identifiable biometric information. The identifiable biometric information may be personal authentication information that can be used to authenticate an individual. The fifth image PIC5 forms types of identification information PIC5a used for identification and identification information PIC5b of the owner corresponding to each type PIC5a. The fourth image PIC4 can be recorded with a laser beam. The fourth image PIC4 can be an image of the illuminated area 11a. The type of identification information PIC5a can be printed or recorded with a laser beam. The type of identification information PIC5a can be printed or recorded with an image of the illuminated area 11a. The identification information PIC5b can be recorded with a laser beam. The identification information PIC5b can be an image of the illuminated area 11a. The identification information PIC5b may be non-biometric information. The certificate 30 can record its type, a portrait of the owner, and the identification information of the owner. A portrait of the owner, or identification information of the owner, may be recorded in the form of illuminated area 11a on certificate 30. Certificate 30 may also include other information that may be used to authenticate the owner of certificate 30.

[0051] FIG. 6 shows a cross-sectional structure of the certificate 30 taken along the line II-II in FIG. As shown in FIG. 6, the certificate 30 includes a support layer 31 in addition to the laminate 10. The support layer 31 can reinforce the laminate 10. The support layer 31 may have a single-layer structure or a multi-layer structure. The support layer 31 has a multi-layer structure and can be composed of a back cover layer 31a and a white layer 31b. In the certificate 30, the back cover layer 31a, the white layer 31b, and the laminate 10 are laminated in this order. In the laminate 10, the recording layer 11 is in contact with the white layer 31b.

[0052] The back surface covering layer 31a can have the same configuration as the front surface covering layer 12 included in the laminate 10. In other words, the back surface covering layer 31a can have light-transmitting properties. The back surface covering layer 31a does not have to have light-transmitting properties. The support layer 31 may also have a colored layer colored in a color other than white, instead of the white layer 31b. In this case, the color of the colored layer can be a color different from the color of the irradiated region 11a included in the laminate 10. This makes it easier to view the image of the irradiated region 11a due to the contrast with the color of the colored layer.

[0053] The surface 31bF of the white layer 31b opposite to the surface in contact with the back side covering layer 31a is the surface 31bF. A printed body 32 may be provided on the surface 31bF of the white layer 31b. The printed body 32 may be formed by printing ink. The printed body 32 may be formed by printing visible ink, invisible ink, or both. Visible printing may be formed by printing visible ink. Invisible printing may be formed by printing invisible ink. The printed body 32 may be provided in an area that overlaps with the security foil 20 when viewed in the thickness direction of the laminate 10.

[0054] The printed body 32 can be a security print. Also, when viewed from the thickness direction of the laminate 10, the irradiated area 11a may be formed in an area overlapping the security print. Identification information or identifiable biometric information may be recorded in the irradiated area 11a overlapping the printed body 32. The irradiated area 11a in which identification information or identifiable biometric information is recorded can be sandwiched between the security foil 20 and the security print. By recording identification information or identifiable biometric information in the irradiated area 11a overlapping the security print, tampering of the identification information or identifiable biometric information can be prevented. In particular, tampering in which different identification information or identifiable biometric information is recorded by scraping the recording layer 11 from the white layer 31b side can be prevented.

[0055] Security printing can also be Guilloche, micro-text, invisible printing, or optically variable printing. Visible ink can be a medium with a pigment dispersed therein or a mixture of pigments and dyes. Visible ink can be optically variable ink by using pearl ink or magnetic ink as the pigment. Printing using optically variable ink can be optically variable printing. Invisible ink can be fluorescent ink or infrared absorbing ink. Fluorescent ink can be ultraviolet-excited fluorescent ink, visible light-excited ink, or infrared-excited ink. Optically variable ink and invisible ink can be used as anti-counterfeiting technology.

[0056] The printing can be gravure printing, offset printing, or screen printing. As shown in Fig. 6, the print 32 is composed of a print part displaying the third image PIC3, a print part displaying the background of the portrait in the fourth image PIC4, and a print part displaying the type PIC5a in the fifth image PIC5. The color of the print 32 may be the same as or different from the color of the irradiated area 11a.

[0057] In the laminate 10 included in the certificate 30, the irradiated area 11a can be opaque, while the unirradiated area 11b can be translucent. Therefore, the print 32 is visible to an observer through the surface 30F of the certificate 30 due to the translucency of the unirradiated area 11b and the surface-side covering layer 12. Note that, in the surface-side covering layer 12, the surface opposite to the surface in contact with the recording layer 11 is the surface 30F of the certificate 30.

[0058] As shown in FIG. 6, the irradiated area 11a can be composed of an area displaying a portrait of the fourth image PIC4 and an area displaying identification information PIC5b of the fifth image PIC5. The portrait of the fourth image PIC4 and the identification information PIC5b of the fifth image PIC5 are different images for each owner of the certificate 30. The owner can be identified by the identification information PIC5b of the fifth image PIC5. By displaying such an image in the irradiated area 11a, it is possible to produce certificates 30 on which information corresponding to each person is recorded, simply by changing the pattern of the laser beam irradiated to the recording layer 11 before the irradiated area 11a is formed among a plurality of certificates 30.

[0059] The information recorded in the irradiated area 11a or the non-irradiated area 11b may be identification information. The identification information may be unique information. The identification information may be personal authentication information that can be used to authenticate an individual. The personal authentication information may include at least one of biometric information and non-biometric information.

[0060] In this way, the certificate 30 has information unique to the owner recorded in the recording layer 11. Therefore, in order to tamper with the certificate 30, it is necessary to replace the tampered recording layer and then attach the security foil 20 to these recording layers, in other words, to reuse the security foil 20. However, as described above, it is difficult to peel off the security foil 20 from the recording layer 11, so tampering with the certificate 30 can be suppressed. Note that if the identification information of the certificate 30 is tampered with, the person to be certified of the certificate 30 can be impersonated.

[0061] On the other hand, the front covering layer 12 separated from the security foil 20 does not contain authentication information, unlike the security foil 20. Therefore, even if the front covering layer 12 is separated from the security foil 20, there is no risk that the certificate 30 will be counterfeited using the front covering layer 12.

[0062] [Materials of each layer of the certificate] The materials used to form each layer of the certificate 30 will now be described. [Each coating layer 12, 31a] The covering layers 12 and 31a may be made of the same material. Of these covering layers 12 and 31a, the front covering layer 12 in particular must be transparent to the wavelength of visible light or the wavelength of observation light so that the first image PIC1 displayed by the security foil 20 can be displayed externally through the front surface 30F of the certificate 30. The covering layers 12 and 31a may be made of polycarbonate, amorphous copolyester, or polyvinyl chloride.

[0063] The thickness of each coating layer 12, 31a can be 50 μm or more and 800 μm or less. Each coating layer 12, 31a with a thickness of 50 μm or more has increased physical strength. The increased physical strength helps prevent defects such as wrinkles in each coating layer 12, 31a. Each coating layer 12, 31a with a thickness of 800 μm or less can reduce thickness variation and bending in each coating layer 12, 31a. The reduced thickness variation and bending of the coating layers 12, 31a helps prevent defects such as warping during lamination.

[0064] [Recording layer 11] When the recording layer 11 is irradiated with a laser beam having a specific wavelength, the laser beam is absorbed, and the material of the recording layer 11 is altered. The altered material of the recording layer 11 can have a predetermined color. The alteration of the material of the recording layer 11 can be carbonized. By carbonizing the material, the material of the recording layer 11 can be black. The reflectance of this black color can be 20% or less. The reflectance can be the ratio of the brightness of the incident light to the brightness of the reflected light. The material of the recording layer 11 may also be a mixture that develops a color when irradiated with a laser beam. Such a mixture can be a mixture containing thermally responsive microcapsules. The recording layer 11 mixed with thermally responsive microcapsules is altered and develops a color due to the reaction of the thermally responsive microcapsules with the laser beam. Therefore, information can be recorded in the recording layer 11 by irradiating the recording layer 11 with a laser beam in a specific pattern.

[0065] The material for forming the recording layer 11 can be a material in which an energy absorber that absorbs a laser beam having a specific wavelength is added to polycarbonate, or a material having an energy absorbing molecular structure. In such a material, the polycarbonate is chemically changed by heat generated when the energy absorber or the energy absorbing molecular structure absorbs the laser beam, and as a result, the recording layer 11 has a predetermined color. An example of this material is LEXAN SD8B94 (manufactured by SABIC) (LEXAN is a registered trademark). In addition to polycarbonate, the material for forming the recording layer 11 can be polyvinyl chloride, amorphous copolyester, etc.

[0066] Furthermore, among polycarbonate, polyvinyl chloride, and amorphous copolyester, the use of polycarbonate as the material for forming recording layer 11 can improve the durability of recording layer 11 and the contrast when color is developed, compared to the use of other materials.

[0067] The thickness of the recording layer 11 can be 50 μm or more and 800 μm or less as described above. By making the thickness of the recording layer 11 50 μm or more, the color development of the irradiated region 11a due to insufficient thickness of the recording layer 11 is suppressed. This suppresses insufficient contrast between the irradiated region 11a and the unirradiated region 11b. On the other hand, by making the thickness of the recording layer 11 800 μm or less, the light transmittance of the unirradiated region 11b is reduced, and the contrast between the irradiated region 11a and the unirradiated region 11b is suppressed to be insufficient. With regard to the adhesive strength in each of the recording layer 11 and the covering layer 12, the thicker the thickness of each layer, the easier it is to disperse stress during peeling, and to achieve high adhesive strength. Therefore, by making the thickness of the recording layer 11 larger than the thickness of the covering layer 12, it is possible to adjust the adhesive strength so as to satisfy the conditions of the present disclosure.

[0068] [White layer 31b] The white layer 31b can be white. When the white layer 31b is white, the printed body 32 and the irradiated area 11a can be easily seen due to the difference in color between the white layer 31b and the printed body 32 and the difference in color between the white layer 31b and the irradiated area 11a. The total light reflectance of the white layer 31b in visible light can be 70% or more and 99% or less. The total light reflectance can be the ratio of the luminance of incident light to the luminance of reflected light. By setting the reflectance in visible light to 70% or more and 99% or less, the visibility of the printed body 32 and the irradiated area 11a can be improved.

[0069] Moreover, the white layer 31b can be concealing. This allows the circuit included in the certificate 30 to be concealed from the observer of the certificate 30. In particular, by covering the entire circuit included in the certificate 30 with the white layer 31b, the circuit can be completely concealed from the observer of the certificate 30. Such circuits can include chips, antennas, resistors, wiring, capacitors, etc. The optical transmission density of the concealing white layer 31b can be 1.0 or more. Also, the optical transmission density of the white layer 31b can be 1.5 or less. Identification information can be recorded on a chip of the circuit included in the certificate 30. The recorded identification information can include identification information recorded on the certificate 30 by a laser beam. The recorded identification information can be encrypted.

[0070] The material for forming the white layer 31b can be polyvinyl chloride, amorphous copolyester, and polycarbonate containing a white material such as titanium oxide. The thickness of the white layer 31b can be 200 μm or more and 800 μm or less. When the thickness of the white layer 31b is 200 μm or more, hiding properties can be easily obtained. When the thickness of the white layer 31b is 800 μm or less, the variation in thickness and bending of the white layer 31b can be reduced. Reducing the variation in thickness and bending of the white layer 31b helps prevent defects such as warping during lamination.

[0071] [Relief layer 21] The material forming the relief layer 21 may be polyester, polyurethane, polyacrylic ester, acid-modified polyolefin, ethylene-vinyl acetate copolymer resin material, polymethyl methacrylate, cyclic polyolefin, melamine, inorganic particles, epoxy resin, cellulose resin, or a mixture, composite, or copolymer of these materials. The material forming the relief layer 21 may be a curable resin. The curable resin is a cured curable precursor. The curable resin may be cured by ultraviolet light, heat, or electron beam. The curable precursor may be thermoplastic.

[0072] The curable precursor for forming the relief layer 21 may be an ultraviolet curable resin, such as a monomer, oligomer, or polymer containing an ethylenically unsaturated bond or group. The monomer may be 1,6-hexanediol, neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate. The oligomer may be epoxy acrylate, urethane acrylate, and polyester acrylate. The curable precursor for forming the relief layer 21 may be a material other than those mentioned above.

[0073] As described above, the material for forming the relief layer 21 may include at least one of polymethylmethacrylate, acid-modified polyolefin, and melamine. These materials have excellent moldability. The relief layer 21 is not limited to a single layer, and may be multi-layered. The multi-layer relief layer 21 may be a laminate of a curable resin and a thermoplastic resin. The relief surface 21R side of the relief layer 21 may be a layer of a curable resin, and the opposite side may be a layer of a thermoplastic resin. The thermoplastic resin may be a resin containing polymethylmethacrylate and acid-modified polyolefin. Alternatively, the multi-layer relief layer 21 may include layers of thermoplastic resins having different physical properties. Alternatively, the relief layer 21 may contain inorganic powder or polymer powder. By containing powder, the adhesive strength between the relief layer 21 and the surface-side coating layer 12 can be adjusted. Therefore, the relief surface 21R side of the relief layer 21 may be a layer of a curable resin, and the opposite side may be a layer of a thermoplastic resin containing inorganic powder or polymer powder.

[0074] [Protective layer 22] The material for forming the protective layer 22 can be the material for forming the relief layer 21. In particular, the material for forming the protective layer 22 can include at least one of polymethyl methacrylate, polyester, cyclic polyolefin, melamine, and ethylene-vinyl acetate copolymer resin. These materials can easily obtain sufficient adhesive strength between the protective layer 22 and a layer containing polycarbonate in contact with the protective layer 22. In addition, the material for forming the protective layer 22 can be a resin having a carbonate bond (-O-CO-O-), a urethane bond (-NH-CO-), or an ester bond (-O-CO-). In adhesion to polycarbonate, there is a tendency for the adhesive strength between polycarbonate and a resin having an ester bond or a urethane bond having a structure similar to that of a carbonate bond to be high. Therefore, by including a resin having these bonds in the protective layer 22, it is easy to increase the adhesive strength between the protective layer 22 and a layer containing polycarbonate in contact with the protective layer 22. The material for forming the protective layer 22 may include a crystalline resin. The crystalline resin may be crystalline polyester or the like. The material forming the protective layer 22 may be a thermoplastic resin. The material forming the protective layer 22 may be a composite of two or more resins with different melting points. The adhesiveness of the crystalline resin can be changed by laser irradiation. This makes it possible to leave a trace when the security foil 20 is peeled off.

[0075] In the laminate 10, the protective layer 22 can include a resin having a lower melting point than polycarbonate, and the relief layer 21 can include a resin having a higher melting point than polycarbonate.

[0076] In particular, in materials such as polycarbonate, which are mainly bonded to other materials by direct melting adhesion using heat and pressure, whether or not the two materials that contact each other, i.e., the materials that form the interface, melt when bonded, has a large effect on the strength of the bond between the two materials. If the two materials that form the interface melt with each other, the bond between them becomes strong. In contrast, if one or both of the two materials are not melted when bonding the two materials, the bond between them becomes weak. Therefore, the protective layer 22 contains a resin having a lower melting point than polycarbonate, and the relief layer 21 contains a resin having a higher melting point than polycarbonate, so that the adhesive strength between the layer containing polycarbonate can be adjusted.

[0077] [Reflection layer 23] The reflective layer 23 may be opaque or translucent. The opaque reflective layer 23 may be a metallic reflective layer. The metal forming the reflective layer 23 may be aluminum or silver. On the other hand, the translucent reflective layer 23 may be a dielectric reflective layer. The dielectric of the reflective layer 23 may be a metal compound or silicon oxide. The metal compound may be a metal sulfide or a metal oxide. The metal sulfide may be zinc sulfide. The metal oxide may be titanium dioxide. The thickness of the reflective layer 23 may be 10 nm or more and 20 nm or less. The reflective layer 23 may be formed by deposition. For the deposition, physical deposition (PVD) or chemical vapor deposition (CVD) may be applied. For the physical deposition, a vacuum deposition method, a sputtering method, or the like may be applied. The reflective layer 23 may be a single layer or a multilayer. The multilayer reflective layer 23 may be formed by performing deposition multiple times.

[0078] The reflective layer 23 may be located on the entire relief surface 21R, or may be located only on a part of the relief surface 21R. When the reflective layer 23 is located only on a part of the relief surface 21R, the reflective layer 23 may be composed of a plurality of areas, and the outer shape of each area may be a geometric pattern, symbol, emblem, coat of arms, or a combination thereof. The symbols and emblems may include flags, shields, swords, spears, crowns, stars, moons, hearts, logos, ribbons, lines, flowers, leaves, grains, fruits, birds, wings, fish, arthropods, mammals, mythical creatures, reptiles, and amphibians. The geometric pattern may be a colored crest (Guilloche). In addition, a part of one reflective layer 23 may be concealing, and the remaining part may be translucent. According to these configurations, in addition to enhancing the design of the certificate 30, the processing for forming the reflective layer 23 becomes more complicated, making it more difficult to counterfeit the certificate 30.

[0079] The method of forming the reflective layer 23 on a part of the relief surface 21R can be the following methods. In the first method, a soluble resin is applied to a part of the relief surface 21R, and then a thin film is formed from a material for forming the reflective layer 23, and the soluble resin is removed by washing together with the thin film formed on the soluble resin. In the second method, a thin film is first formed from a material for forming the reflective layer 23 on the entire relief surface 21R, and then a mask is formed on the thin film using an acid-resistant or alkali-resistant resin. Then, the thin film is etched using the mask. In the third method, a thin film is first formed from a material for forming the reflective layer 23 on the entire relief surface 21R, and then a mask is formed on the thin film using a photosensitive resin. Then, the thin film is etched using the mask. Note that, if it is possible to form the reflective layer 23 only on a part of the relief surface 21R, a method other than these may be used.

[0080] [Print 32] The printed body 32 can have any color. The printed body 32 can be located on the entire surface 31bF of the white layer 31b or on only a part of the surface 31bF. The printed body 32 can be printed with a geometric pattern, a background, a landscape, a pattern, a letter, a number, a sign, a symbol, an emblem, a coat of arms, or a code, or a combination thereof. The symbols and emblems can include flags, shields, swords, spears, crowns, stars, moons, hearts, logos, ribbons, lines, flowers, leaves, grains, fruits, birds, wings, fish, arthropods, mammals, mythical creatures, reptiles, and amphibians. The code can be a one-dimensional code or a two-dimensional code. The one-dimensional code can be a barcode, a serial number, or a combination of both. The two-dimensional code can be a QR code. The geometric pattern can be a Guilloche.

[0081] Ink can be used as a material for forming the printed body 32. Depending on the printing method, the ink can be offset ink, letterpress ink, gravure ink, or the like. Depending on the composition, the ink can be resin ink, oil-based ink, water-based ink, or the like. Depending on the drying method, the ink can be oxidation polymerization type ink, penetration drying type ink, evaporation drying type ink, ultraviolet curing type ink, or the like.

[0082] In addition, the ink may be a functional ink, which changes color depending on the angle of light irradiated onto the certificate 30 or the angle at which the certificate 30 is observed. Examples of such functional inks include optical variable ink, color shift ink, and pearl ink.

[0083] The print 32 may be formed by electrophotography using toner. In this case, toner is prepared by adhering color particles such as graphite and pigment to electrically charged plastic particles. The toner is then transferred to a print medium using static electricity generated by charging, and the toner transferred to the print medium is then heated and fixed to form the print 32.

[0084] [Method of manufacturing laminate] The manufacturing method of the laminate 10 includes preparing the recording layer 11 and the surface-side covering layer 12. The manufacturing method also includes laminating the security foil 20, which includes the relief layer 21 including the relief surface 21R and has a thickness of 1 / 5 or less of the thickness of the recording layer 11, with the recording layer 11 and the surface-side covering layer 12 so as to be located inside the outer edge of the recording layer 11 and the outer edge of the surface-side covering layer 12. The manufacturing method also includes forming a laminate in which the security foil 20 is enclosed by the recording layer 11 and the surface-side covering layer 12 by applying heat and pressure to the recording layer 11, the surface-side covering layer 12, and the security foil 20 in a state in which the security foil 20 is disposed between the recording layer 11 and the surface-side covering layer 12. In the laminate 10 manufactured by such a manufacturing method, the adhesive strength between the security foil 20 and the recording layer 11 is higher than the adhesive strength between the security foil 20 and the surface-side covering layer 12. Hereinafter, the manufacturing method of the laminate 10 will be described with reference to Figs. 7 to 9.

[0085] 7, when manufacturing the laminate 10, first, the security foil 20 is transferred onto the surface of the recording layer 11. Heat and pressure are applied to the security foil 20 on the carrier 41 via the carrier 41, thereby bonding the protective layer 22 and the recording layer 11. Then, the relative position of the carrier 41 with respect to the security foil 20 changes, causing the security foil 20 to peel off from the carrier 41. Note that the security foil 20 may be transferred onto not only the recording layer 11, but also the front-side covering layer 12.

[0086] The security foil 20 can be transferred using a stamper made of metal or resin. In this transfer process, the conditions for transferring the security foil 20 are set as follows: the temperature is set to 80°C or higher and 150°C or lower, the time during which the security foil 20 is in contact with the transfer target by the stamper is set to 0.1 seconds or higher and 3 seconds or lower, and the transfer pressure is set to 100 kg / cm. 2 More than 500kg / cm 2 The temperature, contact time, and transfer pressure can be set to the following values. By setting each of the temperature, contact time, and transfer pressure to below their respective upper limits, it is possible to prevent an excessive amount of heat from transferring the peripheral portion of the security foil 20 to the transferee and to prevent an excessive amount of heat from deforming the surface of the transferee. Also, by setting each of the temperature, contact time, and transfer pressure to above their respective lower limits, it is possible to prevent a portion of the security foil 20 from not being transferred to the transferee due to insufficient adhesion of the security foil 20 to the transferee.

[0087] As shown in FIG. 8, the recording layer 11 to which the security foil 20 has been transferred is covered with the surface-side covering layer 12. Then, by applying heat and pressure to the security foil 20, the recording layer 11, and the surface-side covering layer 12, the recording layer 11 and the surface-side covering layer 12 are bonded together, and the security foil 20 is enclosed by the recording layer 11 and the surface-side covering layer 12. In this bonding process, the recording layer 11 and the surface-side covering layer 12 can be given an amount of heat that softens and deforms the recording layer 11 and the surface-side covering layer 12. This increases the reliability of the bonding between the recording layer 11 and the surface-side covering layer 12. When the recording layer 11 and the surface-side covering layer 12 contain polycarbonate, the temperature of the heat source that gives heat to them can be set to 170° C. or more and 200° C. or less, and the time that the heat source is in contact with them can be set to 1 minute or more and 30 minutes or less. This allows the recording layer 11 and the surface-side covering layer 12, which contain polycarbonate, to be bonded together reliably.

[0088] When the security foil 20 is transferred to the front cover layer 12 in the transfer step, the front cover layer 12 to which the security foil 20 has been transferred may be covered with the recording layer 11 in the adhesion step.

[0089] 9, a laser beam L is irradiated onto a part of the recording layer 11 through the front-side covering layer 12. This irradiation step can form an irradiated area 11a in the recording layer 11. This makes it possible to obtain a laminate 10 having an irradiated area 11a. The laminate 10 having an irradiated area 11a can be used as a certificate.

[0090] The carrier 41 supporting the security foil 20 may be a film. The film may be a plastic film such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polypropylene (PP). The film used for the carrier 41 may be a film that is unlikely to deform or deteriorate due to heat or pressure applied to the carrier 41 when the security foil 20 is transferred. The carrier 41 may be made of paper, synthetic paper, plastic laminated paper, or resin-impregnated paper. The thickness of the carrier 41 may be 4 μm or more. It may also be 12 μm or more and 50 μm or less. By making the thickness of the carrier 41 4 μm or more, it is possible to prevent the carrier 41 from being difficult to handle due to insufficient physical strength of the carrier 41.

[0091] The carrier 41 is not limited to a single-layer structure, and may be a multi-layer structure. When the carrier 41 has a multi-layer structure, it may be configured to include a core layer that provides physical strength to the carrier 41, such as the above-mentioned plastic film, and an intermediate layer located between the core layer and the security foil 20. For such an intermediate layer, a layer that adjusts the ease of peeling of the security foil 20 can be used.

[0092] When manufacturing the above-mentioned certificate 30, the recording layer 11 is covered with the front covering layer 12 in the process previously described with reference to Fig. 7. Then, with the recording layer 11, white layer 31b, and back covering layer 31a laminated in this order, heat and pressure are applied to the security foil 20, recording layer 11, front covering layer 12, white layer 31b, and back covering layer 31a. This makes it possible to form a precursor of the certificate 30. The certificate 30 is obtained by recording identification information and identifiable biometric information in the recording layer 11 of this precursor.

[0093] [Experimental Results] The experimental results and comparison results of the certificate will be explained below. [Experimental result 1] Prior to the manufacture of the certificate, a security foil was formed on a carrier by the following method. First, a 25 μm thick PET film (Lumirror 25T60, manufactured by Toray Industries, Inc.) (Lumirror is a registered trademark) was prepared as a carrier, and resin A for the relief layer was applied to one surface of the PET film by gravure printing. At this time, resin A was applied to the PET film so that the thickness of the coating film after removal by volatilization of the solvent contained in resin A would be 3 μm. Then, a roll forming process was performed by pressing a metal cylindrical plate against the coating film after the solvent was removed. In this way, a relief layer including a relief surface was obtained. At this time, the pressing pressure was set to 2 kgf / cm. 2 The press temperature was set to 240° C., and the press speed was set to 10 m / min.

[0094] Then, a reflective layer made of zinc sulfide (ZnS) was formed on the relief surface with a thickness of 600 Å using a vacuum deposition method. Next, resin B for the protective layer was applied onto the reflective layer by a gravure printing method. At this time, resin B was applied to the reflective layer so that the thickness of the protective layer, which is the layer removed by volatilizing the solvent contained in resin B, was 4 μm. In this way, a security foil formed on a carrier was obtained. The thickness of the security foil was confirmed to be 7.06 μm.

[0095] [Resin A for relief layer] Polymethyl methacrylate 20 parts by weight Polyester 10 parts by weight Methyl ethyl ketone 80 parts by mass

[0096] [Resin B for protective layer] Polyacrylic ester 20 parts by weight Polyester 10 parts by weight Methyl ethyl ketone 50 parts by mass Toluene 50 parts by weight

[0097] Next, a recording layer (LEXAN SD8B94, manufactured by SABIC) having a thickness of 100 μm was prepared, and the security foil was transferred onto the recording layer using a hot stamp transfer machine. At this time, the transfer temperature was set to 140° C., and the pressure was set to 200 kg / cm 2 and the transfer time was set to 1 second.

[0098] Each coating layer (LEXAN SD8B14, manufactured by SABIC) with a thickness of 100 μm and a white layer (LEXAN SD8B24, manufactured by SABIC) with a thickness of 400 μm and on which a print was formed were prepared. Then, the back side coating layer, the white layer, the recording layer, and the front side coating layer were arranged in this order along the thickness direction, and these layers were laminated so that the security foil was enclosed in the recording layer and the front side coating layer. After that, heat and pressure were applied to the laminate of these layers using a heat source to bond the back side coating layer, the white layer, the recording layer, and the front side coating layer. At this time, the temperature of the heat source was set to 190° C., and the pressure was set to 80 N / cm 2 and the time the heat source was in contact with the laminate was set to 15 minutes.

[0099] Next, the obtained laminate was punched into a card shape. Then, a laser printer was used to irradiate a part of the recording layer with a laser beam to form an irradiated area. At this time, a printer that outputs a laser beam with a wavelength of 1064 nm was used as the laser printer. By forming the irradiated area, individual information linked to the owner of the certificate was recorded in the recording layer. In this way, a certificate was obtained.

[0100] [Comparison result 1] The certificate of comparative result 1 was obtained by the same method as experimental result 1, except that the resin for the relief layer was changed from resin A to resin C and the resin for the protective layer was changed from resin B to resin D.

[0101] [Resin C for relief layer] Polyacrylic ester 20 parts by weight Polyester 10 parts by weight Methyl ethyl ketone 50 parts by mass Toluene 50 parts by weight

[0102] [Resin D for protective layer] Polymethyl methacrylate 20 parts by weight Polyester 10 parts by weight Methyl ethyl ketone 80 parts by mass

[0103] [evaluation] For each of the certificates of Experimental Result 1 and Comparative Result 1, the adhesive strength between the security foil and the recording layer, and the adhesive strength between the security foil and the front side coating layer were measured. The adhesive strength was measured using a method conforming to the 90-degree peel test method specified by JIS K 6854-1 (ISO 8510-1). The measurement results for Experimental Result 1 and Comparative Result 1 are shown in Table 1 below. As described above, the thickness of the security foil was 7.06 μm and the thickness of the recording layer was 100 μm, so in both Experimental Result 1 and Comparative Result 1, it was recognized that the thickness of the security foil was approximately 1 / 12.5 of the thickness of the recording layer.

[0104] [Table 1]

[0105] As shown in Table 1, in the certificate of Experimental Result 1, the adhesive strength between the security foil and the front-side coating layer was 5.1 N / 15 mm width, and it was confirmed that separation at the interface between the security foil and the front-side coating layer was possible. In contrast, it was confirmed that the adhesive strength between the security foil and the recording layer was 20 N / 15 mm width or more. It was also confirmed that separation at the interface between the security foil and the recording layer was difficult, and that when an attempt was made to peel the security foil from the recording layer, the security foil was destroyed near the interface between the security foil and the recording layer, and in turn, the relief layer was destroyed. Therefore, it was confirmed that it would be difficult to reuse the security foil included in the certificate of Experimental Result 1.

[0106] On the other hand, in the certificate of comparative result 1, the adhesive strength between the security foil and the front-side covering layer was found to be 20N / 15mm width or more. In addition, when an attempt was made to peel off the security foil from the front-side covering layer, the security foil was destroyed near the interface between the security foil and the front-side covering layer, and the relief layer was also found to be destroyed. In contrast, the adhesive strength between the security foil and the recording layer was found to be 4.6N / 15mm width, and separation at the interface between the security foil and the recording layer was found to be possible. In other words, in comparative result 1, since the security foil was separated from the recording layer together with the front-side covering layer that does not contain individual information, it was found possible to reuse the security foil together with the front-side covering layer, and thus to manufacture a fake certificate by combining the forged recording layer and security foil. In other words, it was found that the security foil included in the certificate of comparative result 1 can be easily reused.

[0107] As described above, according to one embodiment of the laminate, the certificate, and the method for manufacturing the laminate, the following effects can be obtained. (1) Since the thickness of the security foil 20 is 1 / 5 or less of the thickness of the recording layer 11, it is difficult to peel the security foil 20 from the recording layer 11 without destroying it, compared to a configuration in which the thickness of the security foil 20 is approximately the same as that of the recording layer 11. Therefore, it is difficult to manufacture a counterfeit laminate by reusing the security foil 20 provided in the laminate 10.

[0108] (2) By covering the illuminated area 11a with the security foil 20, it is possible to prevent tampering with the information recorded in the illuminated area 11a. (3) When the recording layer 11 contains polycarbonate and the protective layer 22 contains a carbonate bond, a urethane bond, or an ester bond, it is easy to increase the adhesive strength between the recording layer 11 and the protective layer 22.

[0109] (4) The recording layer 11 and the surface side covering layer 12 may contain polycarbonate, the protective layer 22 may contain a resin having a lower melting point than polycarbonate, and the relief layer 21 may contain a resin having a higher melting point than polycarbonate. This makes it possible to increase the adhesive strength between the protective layer 22 and the recording layer 11, and to decrease the adhesive strength between the relief layer 21 and the surface side covering layer 12.

[0110] (5) Since the relief layer 21 contains at least one substance from the first group of substances and the protective layer 22 contains at least one substance from the second group of substances, it is easy to realize a configuration in which the adhesive strength between the security foil 20 and the recording layer 11 is higher than the adhesive strength between the security foil 20 and the front-side coating layer 12.

[0111] (6) Since the relief structure has specific optical properties for incident light, it is difficult to counterfeit the security foil 20. This makes it difficult to counterfeit the laminate 10 including the security foil 20, and as a result, counterfeiting of the laminate 10 can be suppressed.

[0112] (7) The front-side covering layer 12 transmits a part or all of the infrared wavelengths, and the security foil 20 can transmit a part or all of the infrared wavelengths. This makes it possible to form an irradiated area 11a in the recording layer 11 via the front-side covering layer 12 and the security foil 20. That is, when viewed from the thickness direction of the recording layer 11, the irradiated area 11a can be formed in the area covered by the security foil 20.

[0113] The above-described embodiment can be modified as follows. The refractive index of the reflective layer 23 for visible light may be less than 2.0. Even in this configuration, as long as the refractive index of the reflective layer 23 is higher than the refractive index of the relief layer 21, the laminate 10 including the reflective layer 23 can provide at least some of the above-mentioned effects of the reflective layer 23.

[0114] The scope of the present disclosure is not limited to the embodiments shown and described, but includes all embodiments that achieve equivalent effects to those of the present invention. Moreover, the scope of the present disclosure is not limited to the features of the invention defined by the claims, but includes each and every disclosed feature and any combination of features thereof.

[0115] The terms "part," "element," "pixel," "cell," "segment," "unit," "display," and "article" used in this disclosure are physical entities. A physical entity can refer to a material form or a spatial form surrounded by a material. A physical entity can be a structure. A structure can have a specific function. A combination of structures having specific functions can produce a synergistic effect by combining the functions of each structure.

[0116] Terms used in this disclosure and particularly in the appended claims (e.g., the body of the appended claims) are generally intended as "open" terms (e.g., the term "including," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including but not limited to," etc.).

[0117] In addition, when interpreting terms, configurations, features, aspects, and embodiments, drawings should be referred to as necessary. Matters that can be directly and unambiguously derived from the drawings should be the basis for amendment in the same manner as the text.

[0118] Furthermore, where a particular number of introduced claim recitations is intended, such intent is expressly stated in the claim, and in the absence of such recitation, such intent does not exist. For example, to aid in understanding, the following appended claims include the use of the introductory phrases "at least one" and "one or more" to introduce the enumeration of claims. However, the use of such phrases should not be construed as meaning that the introduction of a claim recitation with the indefinite article "a" or "an" limits a particular claim that includes such a claim to an embodiment that includes only one such recitation. The opening phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and / or "an") should be construed to mean at least "at least" ("one" or "one or more"). The same applies to the use of clear articles used to introduce claim recitations.

[0119] In addition, the entire contents of Japanese Patent Application No. 2018-001297 (filed January 9, 2018), from which this application claims priority, are incorporated by reference into this disclosure. [Explanation of symbols]

[0120] 10...laminated body, 10F, 21F, 30F, 31bF...surface, 11...recording layer, 11a...irradiated area, 11b...unirradiated area, 12...surface side coating layer, 20...security foil, 21...relief layer, 21R...relief surface, 22...protective layer, 22R...reverse side, 23...reflective layer, 30...certificate, 31...support layer, 31a...reverse side coating layer, 31b...white layer, 32...printed body, 41...carrier, L...laser beam, PIC1...first image, PIC2...second image, PIC3...third image, PIC4...fourth image, PIC5...fifth image, PIC5a...type of identification information, PIC5b...identification information.

Claims

1. A recording layer; A light-transmitting front-side coating layer; a security foil laminated with the recording layer and the front cover layer and enclosed within the laminate with a thickness of 1 / 5 or less of the thickness of the recording layer; the security foil comprises a relief layer having a relief surface and a protective layer covering the relief surface, the protective layer being in contact with the recording layer and the relief layer being in contact with the front-side covering layer in a thickness direction, the adhesive strength between the security foil and the recording layer is higher than the adhesive strength between the security foil and the front-side covering layer, the relief layer comprises polymethylmethacrylate; The protective layer includes a crystalline resin that is amorphized by irradiation with a laser beam, so that the adhesive strength between the recording layer and the portion of the protective layer irradiated with the laser beam is lower than the adhesive strength between the recording layer and the portion of the protective layer not irradiated with the laser beam. Laminate.

2. The recording layer has an irradiated area in a region covered by the security foil when viewed in the thickness direction of the laminate. The laminate according to claim 1 .

3. the recording layer comprises polycarbonate; The protective layer contains a resin having a carbonate bond, a urethane bond, or an ester bond. The laminate according to claim 1 or 2.

4. The relief surface has at least one of a characteristic of diffracting incident light incident on the relief surface, a characteristic of suppressing reflection of the incident light, a characteristic of isotropically reflecting the incident light, a characteristic of anisotropically reflecting the incident light, a characteristic of converging the incident light, and a characteristic of reflecting a specific polarized light included in the incident light. The laminate according to any one of claims 1 to 3.

5. the front-side coating layer transmits a part or the entire wavelength range of infrared rays; The security foil is transparent to the partial or entire infrared wavelength range. The laminate according to any one of claims 1 to 4.

6. A laminate according to any one of claims 1 to 5; A support layer that reinforces the laminate. Certificate.

7. providing a recording layer and a surface side coating layer; a security foil having a thickness of 1 / 5 or less of the recording layer, the security foil being provided with a relief layer having a relief surface and a protective layer covering the relief surface, the security foil being enclosed by the recording layer and the surface-side covering layer so as to be positioned inside the outer edge of the recording layer and the outer edge of the surface-side covering layer; applying heat and pressure to the recording layer, the surface-side covering layer, and the security foil in a state in which the security foil is disposed between the recording layer and the surface-side covering layer, thereby forming a laminate in which the security foil is enclosed by the recording layer and the surface-side covering layer, the protective layer is in contact with the recording layer, and the relief layer is in contact with the surface-side covering layer; the adhesive strength between the security foil and the recording layer is higher than the adhesive strength between the security foil and the front-side covering layer, the relief layer comprises polymethylmethacrylate; The protective layer includes a crystalline resin that is amorphized by irradiation with a laser beam, so that the adhesive strength between the recording layer and the portion of the protective layer irradiated with the laser beam is lower than the adhesive strength between the recording layer and the portion of the protective layer not irradiated with the laser beam. A method for manufacturing a laminate.

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