Laminates and Cards

Abstract

A laminate of the present invention comprising: a transfer foil configured with at least a patch substrate, a relief forming layer, a reflecting layer, and an adhesive layer being laminated in said order in the thickness direction thereof; a protective sheet provided on a first side in the thickness direction of the transfer foil; and an information recording sheet provided on a second side of the transfer foil, which is the opposite side from the protective sheet, in the thickness direction.

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a laminate having a relief structure, a card, a method for manufacturing a card, a method for producing a card, an information recording sheet for a card, and a card using the same. This application claims priority based on Japanese Patent Application No. 2020-132592 filed on August 4, 2020, Japanese Patent Application No. 2021-067112 filed on April 12, 2021, and Japanese Patent Application No. 2021-095146 filed on June 7, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] Relief structures that have properties such as diffraction, scattering, and reflection and are included in cards on which authentication information is recorded, such as personal identification cards (ID cards), passports, and driver's licenses, are known. The relief structures are composed of periodic or random uneven structures of micrometer to nanometer size. Such relief structures included in cards are more resistant to chemicals, abrasion, and tampering than structures in which the relief structure is located on the outer surface of the card (see, for example, Patent Document 1).

[0003] A structure in which a relief structure is incorporated into a card can be configured such that an anti-counterfeit transfer foil containing the relief structure is sandwiched between two sheets on the card and is positioned inside the outer edges of each sheet.

[0004] When the relief structure is used as an element for verifying authenticity, the relief structure can enhance the effectiveness of preventing counterfeiting and tampering of identification items or valuable items, and can also indicate the value of the item itself, thereby ensuring the value of the item.

[0005] Conventionally, mass-production methods for continuously replicating a relief structure have been disclosed, including a "pressing method" (see Patent Document 2) and a "casting method" (see Patent Document 3) using thermoplastic resins, and a "photopolymer method" (see Patent Document 4). As disclosed in Patent Document 4, the photopolymer method involves pouring a radiation-curable resin, which is cured by irradiation with broad radiation such as ultraviolet (UV) or electron beam (EB), between a mold for replicating the relief structure and a flat substrate such as a plastic film, curing the resin by irradiation to form a cured film, and then peeling the cured film together with the flat substrate such as a plastic film from the replica mold. The relief structure produced by the photopolymer method has higher mechanical strength, better heat resistance, and chemical resistance than relief structures produced by the pressing method and casting method, and also has good molding precision for the concave-convex shape that constitutes the relief structure.

[0006] Furthermore, a laser engraving method is known as a method for preventing counterfeiting and tampering of ID cards, in which pigments and additives that develop color when irradiated with laser light (YAG, CO2, etc.) are kneaded into the base material, primarily made of polycarbonate, and individual information is laser-engraved for each ID card. Laser engraving is considered more difficult to tamper with than inkjet engraving, because the color develops inside the card base material (Patent Document 5). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent No. 6107137 [Patent Document 2] Japanese Patent No. 4194073 [Patent Document 3] Japanese Utility Model Registration No. 2524092 [Patent Document 4] Japanese Patent No. 4088884 [Patent Document 5] Japanese Patent Application Publication No. 2005-271561 Summary of the Invention [Problem to be solved by the invention]

[0008] However, relief structures produced by a photopolymer method using a radiation-curable resin have excellent strength, but can be removed from the card while maintaining the shape of the relief structure. Transfer foils displaying the same image are often used on cards of the same type. In such cards, if it were possible to remove the entire transfer foil, or at least a laminate including the relief structure with its shape maintained, from a genuine card, the removed transfer foil or laminate could be reused to manufacture a counterfeit card containing altered authentication information. If the authentication of a counterfeit card is determined based on the reused transfer foil, it would be difficult to identify the counterfeit card because the transfer foil itself originates from the genuine card. Therefore, there is a possibility of counterfeiting by altering the authentication information and then returning the relief structure to the medium. Considering these circumstances, there is a demand for cards with measures to prevent counterfeiting and tampering with the relief structure.

[0009] Furthermore, in Patent Document 5, there has been a case of tampering in which the surface of the card substrate is scraped to erase the individual information and then different information is printed. This includes tampering in which a different image is overwritten using a laser engraving device, or in which information is overwritten using gravure printing, inkjet printing, or a laser printer.

[0010] Another known method is to store personal information displayed on an ID card in an IC chip, encrypt the digital data in the IC chip, read it with a reader device, analyze the information itself, and verify it to detect and prevent tampering. However, this method requires a reader device and takes time for processing, so it is laborious to make the determination.

[0011] Furthermore, attaching surface-relief diffraction gratings or hologram foils or stickers with relief structures to items is widely used as an anti-counterfeiting measure. When a surface-relief diffraction grating or hologram is transferred to a card or a transparent substrate inside the card and laminated, the foil exists inside the card, making it difficult to tamper with.

[0012] When light is shone on the relief layer present inside the transparent substrate of this card, the incident light passing through the transparent substrate causes interference due to the unevenness, and image information can be reproduced at a certain angle or within a certain range of angles relative to the incident light.

[0013] These relief-type diffraction grating structures and holograms can be mass-produced by creating a master plate on which image information is recorded as concave and convex shapes and then embossing it. They can also be made into stickers or foils for a variety of uses.

[0014] However, this relief-type diffractive structure or hologram has not yet completely eliminated tampering, such as cutting off the foil or seal portion from the substrate and reusing it.

[0015] In light of the above circumstances, an embodiment of the present invention aims to provide a medium that is difficult to illegally reuse for a relief structure, a laminate that is difficult to illegally reuse for a transfer foil having a relief structure, a card, and a method for manufacturing a card. Furthermore, an embodiment of the present invention provides an information recording sheet that makes it more difficult to peel or separate a security patch made of a relief type or the like by increasing the adhesion between the relief type diffraction grating or hologram structure and the card substrate. [Means for solving the problem]

[0016] According to a first aspect of the present invention, a laminate includes a transfer foil formed by laminating at least a patch substrate, a relief-forming layer, a reflective layer, and an adhesive layer in this order along a thickness direction, a protective sheet provided on a first side of the transfer foil in the thickness direction, and an information recording sheet provided on a second side of the transfer foil opposite to the protective sheet in the thickness direction, wherein the relief-forming layer has a relief structure of an uneven shape consisting of concave and convex portions formed on at least a part of a first surface that contacts the reflective layer, and a second surface of the reflective layer that contacts the first surface is formed in a shape that corresponds to the uneven shape of the relief structure. The relief-forming layer is formed from one or a combination of thermoplastic resin, thermosetting resin, and ultraviolet-curing resin, and when viewed from the thickness direction, the relief structure has a plurality of island regions and sea regions formed in a predetermined pattern on the first surface, and the island regions of the relief-forming layer have one or a combination of functional groups including hydroxyl groups, carboxyl groups, and carbonyl groups and a roughened surface, and the sea regions do not have the functional groups or the roughened surface, or have a lower content of functional groups than the island regions, or the degree and area of ​​the roughened surface are smaller.

[0017] In the above-mentioned laminate, the relief-forming layer may comprise a first relief region having a first relief structure in which the recesses and the protrusions are each formed extending in a first direction along the thickness direction and the recesses and the protrusions are alternately formed in a second direction perpendicular to the first direction, and a second relief region having a second relief structure which, when viewed from a direction perpendicular to a plane formed by the first direction and the second direction, is formed with directionality in a direction that differs by at least 30 degrees from the first direction, or in which the recesses and the protrusions are formed irregularly, and may be arranged so that, when viewed from the thickness direction, the first relief region overlaps with the sea region and the second relief region overlaps with the island region.

[0018] According to a second aspect of the present invention, a laminate includes a transfer foil formed by laminating at least a patch substrate, a relief-forming layer, a reflective layer, and an adhesive layer in this order along a thickness direction, a protective sheet provided on a first side of the transfer foil in the thickness direction, and an information recording sheet provided on a second side of the transfer foil opposite to the protective sheet in the thickness direction, wherein the relief-forming layer has a relief structure of an uneven shape with concave and convex portions formed on at least a part of a first surface that contacts the reflective layer, and a second surface of the reflective layer that contacts the first surface has a relief structure of an uneven shape with concave and convex portions formed on at least a part of the first surface that contacts the reflective layer. The relief structure is formed into a corresponding shape, and the relief structure is formed from one or a combination of thermoplastic resin, thermosetting resin, and ultraviolet-curing resin, and when viewed from the thickness direction, the relief structure has a plurality of island regions and sea regions formed in a predetermined pattern on the first surface, and the contact angle of the coating liquid of the adhesive layer with the reflective layer in the island regions is smaller than the contact angle of the coating liquid of the adhesive layer with the reflective layer in the sea regions, and the breaking strength of the adhesive layer is greater than the interfacial adhesion strength and breaking strength between the patch base and the relief-forming layer.

[0019] In the above-mentioned laminate, the relief-forming layer may comprise a first relief region having a first relief structure in which the recesses and the protrusions are each formed extending in a first direction along the thickness direction and the recesses and the protrusions are alternately formed in a second direction perpendicular to the first direction, and a second relief region having a second relief structure which, when viewed from a direction perpendicular to a plane formed by the first direction and the second direction, is formed with directionality in a direction that differs by at least 30 degrees from the first direction, or in which the recesses and the protrusions are formed irregularly, and may be arranged so that, when viewed from the thickness direction, the first relief region overlaps with the sea region and the second relief region overlaps with the island region.

[0020] In the above-described laminate, the area occupied by the island regions may be 50% or more and 80% or less of the total area of ​​the entire region where the island regions and the sea regions are provided.

[0021] In the above-described laminate, the island regions may have the same shape as one another, be regularly arranged, and have a center-to-center distance of 40 μm or more and 400 μm or less between adjacent island regions.

[0022] According to a third aspect of the present invention, a laminate includes a transfer foil configured by laminating at least a patch substrate, a relief-forming layer, a first reflective layer, a second reflective layer, and an adhesive layer in this order along a thickness direction, a protective sheet provided on a first side of the transfer foil in the thickness direction, and an information recording sheet provided on a second side of the transfer foil opposite to the first side in the thickness direction, wherein at least one of the first reflective layer and the second reflective layer is made of a light-transmitting material having a refractive index higher than that of the relief-forming layer and the adhesive layer, the relief-forming layer has a relief structure with a concave-convex shape consisting of concaves and convex portions formed on at least a part of a first surface that contacts the first reflective layer, and a second surface of the first reflective layer that contacts the first surface is formed into a shape that corresponds to the concave-convex shape of the relief structure, and the first reflective layer and the second reflective layer contact each other, corresponding surface shapes are formed, and when viewed from the thickness direction, the transfer foil has a plurality of first regions and second regions formed in a predetermined pattern, the first reflective layer and the second reflective layer are provided in the first region, and only the first reflective layer is provided in the second region, the interfacial adhesion strength between the first reflective layer and the adhesive layer is different from the interfacial adhesion strength between the second reflective layer and the adhesive layer, and of the first region and the second region, one region in which the interfacial adhesion strength at the interface with the adhesive layer is relatively high is an island region scattered in the other region, and the region in which the interfacial adhesion strength at the interface with the adhesive layer is relatively low is a sea region surrounding the region in which the interfacial adhesion strength at the interface with the adhesive layer is relatively high.

[0023] In the above-mentioned laminate, the interfacial adhesion strength at the interface of each layer of the transfer foil may be smaller than the interfacial adhesion strength between the transfer foil and the protective sheet or the information recording sheet, and the interfacial adhesion strength between the patch base and the relief forming layer and the breaking strength of the relief forming layer may be smaller than the interfacial adhesion strength between the first reflective layer and the second reflective layer and the interfacial adhesion strength between the relief forming layer and the first reflective layer.

[0024] In the above-described laminate, the first reflective layer or the second reflective layer and the adhesive layer may both have hydrophilic or hydrophobic surface properties in the island regions, and may have different surface properties in the sea regions or may have surface properties similar to those of the island regions, and the contact angle of the coating liquid of the adhesive layer with the first reflective layer or the second reflective layer may be smaller in the island regions.

[0025] In the above-described laminate, in the island region, the first reflective layer or the second reflective layer and the adhesive layer may be bonded by at least one chemical interaction of an ionic bond, a covalent bond, or a hydrogen bond, and in the sea region, the first reflective layer or the second reflective layer and the adhesive layer may be bonded by a physical interaction due to an intermolecular force.

[0026] In the laminate described above, the area occupied by the island regions may be 50% or more and 80% or less of the total area of ​​the entire region where the island regions and the sea regions are provided.

[0027] In the above-described laminate, the island regions may have the same shape as one another, be regularly arranged, and have a center-to-center distance of 40 μm or more and 400 μm or less between adjacent island regions.

[0028] According to a fourth aspect of the present invention, the card further comprises the above-mentioned laminate and a support layer provided on the first side of the transfer foil.

[0029] According to a fifth aspect of the present invention, there is provided a method for manufacturing a card comprising: a transfer foil including, in a thickness direction, at least a patch substrate, a relief-forming layer, a first reflective layer, a second reflective layer, and an adhesive layer; a protective sheet and a support layer provided on a first side of the transfer foil in the thickness direction; and an information recording sheet provided on a second side of the transfer foil opposite to the protective sheet in the thickness direction of the transfer foil, the method comprising the steps of: preparing the transfer foil in which the patch substrate, the relief-forming layer, the first reflective layer, the second reflective layer, and the adhesive layer are laminated in this order; transferring the transfer foil to the protective sheet or the information recording sheet; and an adhesion process of laminating the transferred material to the protective sheet and the support layer, and the process of producing the transfer foil comprises a process of forming a relief structure having concave and convex portions on at least a portion of the surface of the relief-forming layer that contacts the first reflective layer, a process of forming the first reflective layer having a concave and convex shape that follows the relief structure, and a process of forming the second reflective layer having a concave and convex shape that corresponds to the surface shape of the first reflective layer, and a process of removing the second reflective layer in a plurality of first and second regions that form a predetermined pattern when the transfer foil is viewed from the thickness direction, so that the first regions comprise the first reflective layer and the second reflective layer, and the second regions comprise only the first reflective layer.

[0030] In the above-mentioned card manufacturing method, the process of producing the transfer foil may include a process of forming the second reflective layer, then providing an etching mask layer in the first area, and a process of removing the second reflective layer in the second area, then further removing the etching mask layer.

[0031] According to a sixth aspect of the present invention, a medium comprises a security patch having an adhesive layer, a tear layer, and a certification layer laminated in that order along the thickness direction, with a relief structure between the tear layer and the certification layer; a protective sheet adhered to the adhesive layer in the thickness direction of the security patch; and an information recording sheet provided on the opposite side of the adhesive layer in the thickness direction of the security patch and adhered to the certification layer of the security patch, wherein the security patch is enclosed by the protective sheet and the information recording sheet, the tear layer has a breaking strength of 15 N / 25 mm or more and less than 45 N / 25 mm in a 90-degree peel adhesion strength test, and the adhesive strength between the security patch and the information recording sheet and the adhesive strength between the security patch and the protective sheet are 5 N / 25 mm or more greater than the breaking strength of the tear layer and are 5 times or less than the breaking strength of the tear layer.

[0032] In the above-described medium, the fracture layer may be composed of an optically transparent resin and a filler formed from particles having an average particle size of 1 μm or less.

[0033] According to a seventh aspect of the invention, a card comprises a medium as described above and another layer of material provided for storing information.

[0034] According to an eighth aspect of the present invention, a method for manufacturing a medium is a method for manufacturing the medium described above, and includes the steps of transferring and adhering the security patch to the surface of one of the information recording sheet and the protective sheet, and applying an external force to the other of the information recording sheet and the protective sheet and the security patch so as to cover the security patch.

[0035] According to a ninth aspect of the present invention, an information recording sheet for a card is an information recording sheet for a card used in the above-mentioned laminate or the above-mentioned medium, and the information recording sheet is made of polycarbonate blended with polyester.

[0036] In the above-mentioned information recording sheet for cards, the polyester may have a glass transition temperature Tg of -20°C to 110°C.

[0037] According to a tenth aspect of the present invention, a card uses the above-mentioned card information recording sheet. [Effects of the Invention]

[0038] According to the above-described aspects, it is possible to provide a laminate, a card, and a method for manufacturing a card that make it difficult to fraudulently reuse a transfer foil with a relief structure. Furthermore, it is possible to provide a medium and a card that make it difficult to fraudulently reuse the relief structure. It is also possible to provide a method for manufacturing such a medium. It is possible to provide a card that is difficult to reuse by tearing off a security patch applied to prevent counterfeiting and alteration, without making the manufacturing process more complicated or cumbersome. [Brief explanation of the drawings]

[0039] [Figure 1] 1 is a plan view schematically illustrating a laminate of the present invention. [Figure 2A] FIG. 2 is a cross-sectional view illustrating the configuration of the laminate taken along line AI-AI in FIG. [Figure 2B] FIG. 2 is a cross-sectional view illustrating the configuration of the laminate taken along line AI-AI in FIG. [Figure 3] FIG. 2 is a plan view for schematically explaining the configuration of a transfer foil. [Figure 4] FIG. 4 is a cross-sectional view illustrating the configuration of the laminate taken along line 1A-1A in FIG. 3. [Figure 5A] 10A and 10B are plan views for schematically explaining examples of the shapes and arrangements of island regions. [Figure 5B] FIG. 10 is a plan view for schematically explaining an example of the shape and arrangement of island regions. [Figure 5C] 10A to 10C are plan views for schematically explaining other examples of the shape and arrangement of island regions. [Figure 5D] 10A to 10C are plan views for schematically explaining other examples of the shape and arrangement of island regions. [Figure 5E] 10A to 10C are plan views for schematically explaining other examples of the shape and arrangement of island regions. [Figure 5F] 10A to 10C are plan views for schematically explaining other examples of the shape and arrangement of island regions. [Figure 6A] 1A and 1B are a plan view and a cross-sectional view schematically illustrating an example of a relief structure. [Figure 6B] 10A and 10B are a plan view and a cross-sectional view schematically showing another example of a relief structure. [Figure 6C] 10A and 10B are a plan view and a cross-sectional view schematically showing another example of a relief structure. [Figure 6D] 10A and 10B are a plan view and a cross-sectional view schematically showing another example of a relief structure. [Figure 6E] 10A and 10B are a plan view and a cross-sectional view schematically showing another example of a relief structure. [Figure 6F] 10A and 10B are a plan view and a cross-sectional view schematically showing another example of a relief structure. [Figure 7A] FIG. 10 is a cross-sectional view for schematically explaining an example of a state in which the stacked body is separated. [Figure 7B] FIG. 10 is a cross-sectional view for schematically explaining another example of a state in which the stacked body is separated. [Figure 8] 1 is a plan view illustrating the configuration of a transfer foil of the present invention. FIG. [Figure 9] 2A is a cross-sectional view illustrating the configuration of the laminate taken along line 2A-2A in FIG. 8. FIG. [Figure 10A] FIG. 1 is a diagram for explaining a contact angle. [Figure 10B] FIG. 1 is a diagram for explaining a contact angle. [Figure 10C] FIG. 1 is a diagram for explaining a contact angle. [Figure 11] 1 is a plan view schematically illustrating a laminate of the present invention. [Figure 12A] FIG. 11 is a cross-sectional view illustrating an example of the configuration of the laminate taken along the line AII-AII in FIG. [Figure 12B] FIG. 10 is a cross-sectional view illustrating another example of the configuration of the laminate. [Figure 13]1 is a plan view illustrating the configuration of a transfer foil of the present invention. FIG. [Figure 14] 14 is a cross-sectional view illustrating an example of the configuration of the laminate taken along line 3A-3A in FIG. 13. FIG. [Figure 15] FIG. 10 is a cross-sectional view illustrating another example of the configuration of the laminate. [Figure 16] FIG. 10 is a plan view illustrating an example of an image display using island regions and sea regions. [Figure 17] FIG. 10 is a plan view illustrating another example of an image display using island regions and sea regions. [Figure 18] 1 is a schematic diagram illustrating an example of a method for observing a laminate of the present invention. [Figure 19] 1 is a plan view illustrating an example of the appearance of a laminate of the present invention. FIG. [Figure 20] FIG. 1 is a plan view illustrating an example of a card provided with a laminate of the present invention. [Figure 21] FIG. 20 is a cross-sectional view illustrating the configuration of the card taken along line BI-BI in FIG. [Figure 22] 1 is a plan view for schematically explaining the configuration of a medium of the present invention. [Figure 23] 23 is a cross-sectional view of the medium according to FIG. 22 taken along line AA. [Figure 24] FIG. 24 is a cross-sectional view illustrating a state in which the security patch has been separated from the protection sheet in the cross section illustrated in FIG. 23. [Figure 25] 1 is a plan view for explaining the configuration of a card according to the present invention. FIG. [Figure 26] FIG. 26 is a cross-sectional view of the card according to FIG. 25 taken along line BB. [Figure 27A] 1A to 1C are diagrams illustrating a method for producing a medium according to the present invention. [Figure 27B] 1A to 1C are diagrams illustrating a method for producing a medium according to the present invention. [Figure 27C] 1A to 1C are diagrams illustrating a method for producing a medium according to the present invention. [Figure 28A] 1 is a cross-sectional photograph illustrating the configuration of a medium according to each embodiment of the present invention. [Figure 28B]1 is a cross-sectional photograph illustrating the configuration of a medium according to each embodiment of the present invention. [Figure 29] 1 is a cross-sectional view of an information recording sheet for cards according to the present invention; [Figure 30] 1 is a cross-sectional view of a card according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0040] The embodiments of the present invention are a group of embodiments based on a single, independent invention from the background. Also, each aspect of the present invention is an aspect of a group of embodiments based on a single invention. Each configuration of the present invention may have each aspect of the present invention. Each feature of the invention can be combined to form each configuration. Therefore, each feature of the present invention, each configuration of the present invention, each aspect of the present invention, and each embodiment of the present invention can be combined, and the combination can have synergistic functions and produce synergistic effects.

[0041] In this specification, drawings are used to explain the configuration of the present invention. Dimensions shown in each drawing, such as the thickness of each layer and their ratios, may differ from the actual configuration, and the dimensional ratios in the drawings should not be interpreted as being limited to the ratios shown therein. Furthermore, for ease of explanation, similar components in each embodiment are denoted by the same reference numerals and redundant explanations are omitted. Furthermore, the first to seventh embodiments are described separately to clearly explain the embodiments of the present invention, but are not intended to describe separate inventions. Furthermore, physical elements and means such as media, layers, members, structures, and shapes may be named differently for the sake of explanation.

[0042] (First embodiment) A laminate and a card according to an embodiment of the present invention will be described below as a first embodiment with reference to Figures 1 to 7. The embodiment described here is one preferred embodiment of the present invention, and unless otherwise specified in the following description, the embodiments of the present invention are not limited to these forms. Furthermore, those skilled in the art can modify the design of the embodiment described below as appropriate.

[0043] (Laminate) FIG. 1 is a plan view that schematically illustrates the configuration of a laminate 10. As shown in FIG. 1, the laminate 10 is formed in a sheet shape. The contour shape of the laminate 10 is shown as a rectangle with rounded corners, but may be a circle, an ellipse, or other shape besides a rectangle. When viewed from a plan view facing the surface 10S, i.e., when viewed from the thickness direction of the laminate 10, the laminate 10 includes a transfer foil 11 located inside the outer edge of the laminate 10. An image 12 is recorded on the transfer foil 11 as authentication information. In FIG. 1, the contour shape of the transfer foil 11 is shown as a circle, but may be a rectangle, an ellipse, or other shape besides a circle.

[0044] FIG. 2 is a cross-sectional view of the laminate 10 taken along line AI-AI in FIG. 1. The transfer foil 11 is configured by sequentially stacking a patch substrate 13, a relief-forming layer 14, a reflective layer 16, and an adhesive layer 17. A relief structure 15 is formed on the surface of the relief-forming layer 14, and the reflective layer 16 is provided to conform to the relief structure 15's concave-convex shape. The transfer foil 11 includes at least the above layers in the order listed, but may also include other layers. The transfer foil 11 is laminated with a protective sheet 18 and an information recording sheet 19, and is enclosed within the laminate 10 so that the transfer foil 11 is not exposed to the outside. FIGS. 2A and 2B show the reversed layer configuration of the transfer foil 11 incorporated within the laminate 10, but either configuration is acceptable. In the configuration of FIG. 2A, the transfer foil 11 is transferred to the protective sheet 18 via the adhesive layer 17 and then laminated. On the other hand, in the case of the configuration of FIG. 2B, the transfer foil 11 is transferred onto the information recording sheet 19 via the adhesive layer 17 and then laminated. A fracture layer 108, 202 may be present between the adhesive layer and the relief-forming layer 14. This can be provided to adjust the adhesive strength between the transfer foil 11 and the protective sheet 18 and the information recording sheet 106. The security patch 102 described later may be the transfer foil 11. The protective sheet 18 is described as a protective substrate layer 18 in Japanese Patent Application No. 2021-095146. The patch substrate 13 is described as a release layer 13 in Japanese Patent Application No. 2021-095146.

[0045] The optical effect of the relief structure 15 creates an image 12 visible to a viewer of the laminate 10. While the image 12 is depicted as a star in the example of FIG. 1 , it can be a portrait, a landmark motif, a nature motif, calligraphy, a geometric pattern, a letter, a number, a signal, a sign, a symbol, an emblem, a coat of arms, or a code, or a combination thereof. Examples of symbols are flags, shields, swords, spears, crowns, flowers, leaves, plants, birds, fish, arthropods, mammals, reptiles, amphibians, mythical creatures, mythical gods, and mythical goddesses. Examples of nature motifs are living creatures, stars, the moon, the sky, mountains, valleys, and rocks. Examples of biological motifs are flower, leaf, grain, fruit, birds, wings, fish, arthropod, mammal, reptile, and amphibian motifs. The code can be a one-dimensional code or a two-dimensional code. Examples of one-dimensional codes can be bar codes, serial numbers, or a combination of both. An example of a two-dimensional code may be a QR code. An example of a geometric pattern is a guilloche. Examples of mythical creatures are the unicorn, dragon, and phoenix. Examples of symbols are symbols representing countries, regions, states, groups, parliaments, treaties, alliances, unions, and axes.

[0046] (Island area / sea area) The island regions R1, sea regions R2, and relief structure 15 that constitute the laminate 10 will be described below. 3 is a plan view showing the configuration of the transfer foil 11. The transfer foil 11 has island regions R1 and sea regions R2. In the example shown in the figure, the island regions R1 and sea regions R2 extend over the entire surface of the transfer foil, but they may be provided only in a portion of the transfer foil 11.

[0047] FIG. 4 is a partial cross-sectional view taken along line 1A-1A in FIG. 3, showing the relief-forming layer 14 and the relief structure 15 corresponding to the island regions R1 and the sea regions R2. In the island regions R1, the surface of the relief-forming layer 14 on which the relief structure 15 is formed is made of a thermoplastic resin or an ultraviolet-curable resin having at least one of the functional groups hydroxyl (-OH), carboxyl (-COOH), and carbonyl (C=O) in its side chain. Alternatively, the surface of the relief-forming layer 14 is roughened. On the other hand, in the sea regions R2, these functional groups and a roughened surface are not present, or the content of functional groups present on the surface of the relief-forming layer 14 is lower than in the island regions R1, or the degree or area of ​​the roughened surface is smaller.

[0048] Generally, many resins, especially polyolefin-based synthetic resins such as polypropylene and polyethylene, lack polar groups on their surfaces and are hydrophobic, resulting in a lack of affinity for adhesives and inks. Therefore, in secondary processing of resins, surface modification is performed using techniques such as corona treatment and plasma treatment to improve hydrophilicity by introducing polar functional groups to the resin surface. Corona treatment and plasma treatment involve dissociating oxygen molecules in the air through electrical discharge, exciting oxygen atoms and generating plasma containing oxygen ions and free electrons. The electrons, ions, and radicals of the generated plasma sever chemical bonds between molecules on the resin surface, generating hydrophilic functional groups such as hydroxyl, carboxyl, and carbonyl groups, depending on the type of resin. This facilitates bonding with other materials and is expected to improve adhesion. Furthermore, discharge can physically roughen the resin surface, thereby ensuring sufficient surface area and improving adhesion to adhesives and inks. Another benefit of corona treatment and plasma treatment is the removal of organic contaminants from the resin surface. In the transfer foil 11 of the first embodiment, if the resin constituting the relief forming layer 14 does not contain polar functional groups, the adhesion between the relief forming layer 14 and the reflective layer 16 can be improved by generating polar functional groups on the surface through surface modification such as corona treatment or plasma treatment.

[0049] Only the island regions R1 on the surface of the relief-forming layer 14 are provided with functional groups or roughened, while the sea region R2 is not. This allows for a difference in interfacial adhesive strength between the relief-forming layer 14 and the reflective layer 16 between the island regions R1 and the sea region R2. Here, "interfacial adhesive strength" can be defined as the strength of the bond at the interface between the two layers. The present invention aims to prevent the fraudulent reuse of the transfer foil 11. It is anticipated that a counterfeiter may attempt to remove the transfer foil 11 by making a slit in the area of ​​the transfer foil 11 containing the image 12 from the surface of the laminate 10 and peeling it off with cellophane tape or a tool such as tweezers. The 90-degree peel adhesive strength test method specified by JIS K 6854-1 (ISO 8510-1) is a test method that can measure adhesive strength (including interfacial failure and cohesive failure) under conditions similar to those acting on the transfer foil 11. The interfacial adhesive strength can be measured using a method conforming to this method.

[0050] As described above, simply by making the interfacial adhesive strength between the relief-forming layer 14 and the reflective layer 16 different between the island region R1 and the sea region R2, it is possible to prevent separation while maintaining the shape of the relief structure 15 even if an unauthorized attempt is made to remove the transfer foil 11 from the laminate 10. Therefore, the above-mentioned effect can be obtained even if the relief structure 15 has the same shape and arrangement direction in the island region R1 and the sea region R2.

[0051] FIGS. 5A to 5F show examples of the shape and arrangement of island regions R1. More specifically, FIGS. 5A to 5E show an example in which island regions R1 are regularly arranged. FIG. 5F shows an example in which island regions R1 are irregularly arranged. Furthermore, regions in which island regions R1 are irregularly arranged may also be regularly arranged. In FIG. 5A, adjacent island regions R1 are arranged so that the center-to-center distance D1 is in the X direction and the center-to-center distance D2 is in the Y direction. The center-to-center distance D1 and the center-to-center distance D2 of adjacent island regions R1 may be equal or different. FIGS. 5B and 5C show modifications of the configuration shown in FIG. 5A. In FIGS. 5B and 5C, the two axes along which the island regions R1 are regularly arranged are indicated by dashed dotted lines. In FIGS. 5B and 5C, the center-to-center distances D1 and D2 in the two axial directions along which adjacent island regions R1 are arranged are shown. Furthermore, in FIGS. 5B and 5C, the center-to-center distances D1 and D2 are the shortest distances between adjacent island regions R1. In Fig. 5B, the island regions R1 are adjacent to each other via the sea region R2, but in Fig. 5C, the island regions R1 are partially in contact on the two axes. The island regions R1 are dispersed within the sea region R2. The island regions R1 may be separated from each other, or may be partially in contact with each other, or there may be both separated island regions R1 and partially in contact with each other.

[0052] The shape of the island region R1 is shown as a rectangle with rounded corners in Figures 5A to 5C, but is not limited to this and may be an ellipse or circle as shown in Figure 5D, or a polygon as shown in Figure 5E.

[0053] As shown in Figure 5F, the island regions R1 may be arranged randomly. Here, "random arrangement" means an arrangement in which the island regions R1 are not regularly arranged along two axes, as shown in Figures 5A to 5E. Therefore, although Figure 5F shows only two examples of center-to-center distances D1 and D2 between adjacent island regions R1, there may be two or more center-to-center distances between the island regions R1.

[0054] The island regions R1 preferably have center-to-center distances D1 and D2 of 40 μm to 400 μm and a size of 20 μm to 300 μm. Here, "size" is defined as the length between the two most distant sides on the periphery of the island region R1 when the island region R1 has sides in the X and Y directions, and as the length between the most distant two points on the periphery of the island region R1 when the island region R1 has no sides in the X and Y directions. Therefore, as shown in FIG. 5A, if the island region R1 has a rectangular shape with sides in the X and Y directions, the size L is the length of the side in the X direction (or the longer side in the Y direction). As shown in FIG. 5D, if the island region R1 has an elliptical shape with no sides in the X and Y directions, the size L is the length between the most distant two points.

[0055] The average area occupied by the island regions R1 is preferably 50% to 80% of the total area of ​​the entire region including the island regions R1 and the sea regions R2. By setting the area occupied by the island regions R1 in this manner, the separation state of the island regions R1 is reflected in more than half of the surface when the transfer foil 11 is separated from the laminate 10, and if an attempt is made to illegally remove the transfer foil 11, the optical effect derived from the relief structure 15 is lost, thereby enhancing the effect of preventing reuse.

[0056] The area occupied by the island regions R1 is determined by the size L of the island regions R1 and the center-to-center distance of adjacent island regions R1. In addition to these two parameters, the surface condition when the transfer foil 11 is separated is also affected by the area of ​​the sea regions R2 existing between adjacent island regions R1 and whether the island regions R1 are arranged regularly or randomly.

[0057] (relief structure) The relief structure 15 is a plurality of minute concave-convex shapes with a height difference between the bottom surfaces of the concave portions and the top surfaces of the convex portions in the thickness direction of the transfer foil 11 of 0.02 μm to 5 μm, and is configured with intervals of 0.1 μm to 20 μm between each other in the width direction (direction perpendicular to the thickness direction) of the transfer foil 11. Hereinafter, the center-to-center distance between adjacent concave portions and the center-to-center distance between adjacent convex portions will be referred to as the "period."

[0058] As shown in Fig. 4, the first relief structure 15a formed in the first relief region SR1 extends in a first direction (Y direction) shown in Fig. 3 and has a shape in which recesses and protrusions are alternately arranged in a second direction (X direction) perpendicular to the first direction. On the other hand, the second relief structure 15b formed in the second relief region SR2 extends in a third direction different from the first direction and has a shape in which recesses and protrusions are alternately arranged in a fourth direction perpendicular to the third direction. Because Fig. 4 is a cross-sectional view, it is difficult to see how the first relief structure 15a and the second relief structure 15b extend in different directions, but the third direction in which the second relief structure 15b extends differs from the first direction (Y direction) by 30 degrees or more.

[0059] 4, the first relief region SR1 is arranged to correspond to the sea region R2, and the second relief region SR2 is arranged to correspond to the island region R1. That is, the first relief region SR1 can be the sea region R2, and the second relief region SR2 can be the island region R1. If the two do not coincide, a configuration in which the first relief region SR1 is included in the sea region R2 and the second relief region SR2 is included in the island region R1 is preferable, and a configuration in which the sea region R2 is bordered by the first relief region SR1, and the island region R1 is bordered by the second relief region SR2 is particularly preferable. With this configuration, when an attempt is made to remove the transfer foil 11 from the laminate 10 along the first direction, in the island regions R1, the interfacial adhesion strength between the relief-forming layer 14 and the reflective layer 16 is high, and in addition, the second relief structure 15b extending in a direction (third direction) different from the direction in which force is applied (first direction) acts as a resistance force (anchor effect), further increasing the interfacial adhesion strength between the two layers and reducing the possibility of separation at the interface between the two layers. On the other hand, in the sea regions R2, the interfacial adhesion strength between the relief-forming layer 14 and the reflective layer 16 is lower than in the island regions R1, and in addition, the first relief structure 15a extends in the first direction, which is the same as the direction in which force is applied, so the anchor effect of the first relief structure 15a is small, increasing the possibility of separation at the interface between the relief-forming layer 14 and the reflective layer 16. Therefore, when attempting to remove the transfer foil 11 from the laminate 10, the layers that separate or break are different in the island region R1 and the sea region R2, and the shape of the relief structure 15 is not maintained, which impairs the optical effect of the image 12 and makes it difficult to reuse.

[0060] The relief structure 15 does not necessarily have to be formed in all of the island regions R1 and sea regions R2, and a part of each region may be a flat surface without a structure. The region in which the relief structure 15 is formed may be determined depending on the design of the image 12.

[0061] The relief structure 15 provided in the island region R1 and the sea region R2 has been described above with reference to Figure 4, but in the present invention, the relief structure 15 may be formed using one or a combination of multiple optical structures, such as an optical diffraction structure, a non-reflective structure, an isotropic or anisotropic scattering structure, a lens structure, and a polarization-selective reflection structure, and also includes the structures shown in Figures 6A to 6F.

[0062] 6A to 6F are diagrams showing examples of relief structure 15. More specifically, the diagrams are plan views and cross-sectional views, with FIGS. 6A and 6B showing an example of a first relief structure 15a, and FIGS. 6C to 6F showing an example of a second relief structure 15b. In the drawings, the black parts are recesses, and the white parts are protrusions. For convenience, the cross-sectional views show the recesses and protrusions as rectangular or pyramidal, but the shapes are not limited to these and may be wavy, sawtooth, or tapered shapes such as trapezoidal.

[0063] The first relief structure 15a may have any configuration in which the recesses and protrusions extend in the first direction. In the example of FIG. 6A, recesses having a constant width are arranged alternately with protrusions at irregular intervals in the second direction. The width of the recesses does not have to be constant. Furthermore, the recesses and protrusions arranged in the second direction may be arranged alternately at irregular intervals in a specific region, and the region may be arranged at a regular interval. Furthermore, as in the example of FIG. 6B, as long as the structure has directionality in the first direction, rectangular recesses in a plan view may be partially connected to form polygonal recesses. Furthermore, the recesses and protrusions may extend discontinuously (intermittently). It is preferable that the ratio of the length extending in the first direction to the width of the recess is 2 or more.

[0064] The second relief structure 15b does not have to extend in the same first direction as the first relief structure 15a. In the example of Fig. 6C, the recesses and protrusions extend in a third direction different from the first direction. Here, the third direction differs from the first direction by 30 degrees or more. The greater the angle difference from the first direction, the greater the effect of preventing fraudulent use of the transfer foil 11. It is most preferable that the angle difference is 90 degrees (extending in the second direction).

[0065] The second relief structure 15b may have a configuration in which a plurality of recesses are irregularly arranged as shown in FIG. 6D. In the example shown in FIG. 6D, the recesses have a square outer shape in plan view, but the present invention is not limited to this. The recesses may have a rectangular or circular outer shape in plan view. Irregularly arranging the recesses can also suppress diffracted light. The recesses may have the same shape. In addition, the recesses and protrusions aligned in the second direction may alternate at irregular intervals in a specific region, and the region may be arranged at a regular interval.

[0066] The period between adjacent recesses is preferably 0.2 μm or more. The depth of the recesses may be set to a predetermined value within a range of 0.05 μm to 5 μm, or may not be a constant value. The structure shown in FIG. 6D allows for the optical effect, particularly the hue, to be varied depending on the depth of the recesses. A specific color can be displayed when the depth of the recesses is constant in a certain region, while a white color can be displayed when the depth of the recesses is random.

[0067] In the structure shown in Figure 6E, recesses each consisting of one or more squares or rectangles in plan view are randomly arranged. As shown in Figure 6E, the sizes of the squares or rectangles do not have to be uniform, and they may overlap in part. The depth of the recesses can be 0.05 µm to 1 µm, and it is preferable that the variation in depth of all recesses is 0.05 µm or less.

[0068] In the structure shown in FIG. 6F (A), the relief structure 15b is a cross grating in which recesses extending in a first direction intersect with recesses extending in a second direction in a plan view. As shown in the cross-sectional view of FIG. 6F (B) along line 1G-1G, the structure has protrusions formed at regular intervals. While this example shows a cross-sectional view along the second direction, the structure also has a similar shape in the first direction, with protrusions shaped like square pyramids or rounded cones formed at regular intervals. In the example of FIG. 6F, the protrusions have rectangular bases and a conical shape, but this is not limited to this. The bases of the protrusions may be circular or polygonal, and may also be columnar or bell-shaped. The period of the recesses and protrusions can be 0.1 μm to 2 μm, which functions as a moth-eye structure, particularly in the case of sub-wavelengths.

[0069] (Function of laminate) The operation of the laminate 10 will be described below with reference to FIGS. 7A and 7B. FIGS. 7A and 7B are cross-sectional views schematically illustrating a state in which the transfer foil 11 has been separated. If an attempt is made to destroy the laminate 10 and remove the transfer foil 11 by unauthorized means, delamination occurs between layers of the laminate 10 with low interfacial adhesive strength, or cohesive failure occurs within a layer with low rupture strength, resulting in separation of the transfer foil 11. The following explanation is based on the assumption that the interfacial adhesive strength between the patch substrate 13 and the information recording sheet 19 and the interfacial adhesive strength between the adhesive layer 17 and the protective sheet 18 are greater than the interfacial adhesive strength between the protective sheet 18 and the information recording sheet 19. While the example in FIG. 7 shows a configuration in which the adhesive layer 17 and the protective sheet 18, and the patch substrate 13 and the information recording sheet 19 are in contact with each other, the transfer foil 11 may be upside down as shown in FIG. 2.

[0070] When attempting to remove the transfer foil 11 from the laminate 10, the protective sheet 18 and the information recording sheet 19 are first separated. At this time, in the region including the transfer foil 11, separation occurs between or within layers with the lowest interfacial adhesive strength or breaking strength within the transfer foil 11. As described above, in the first embodiment, the island regions R1 and the sea regions R2 have different surface characteristics (presence and degree of functional groups and / or roughness) that contact the reflective layer 16 of the relief-forming layer 14. This results in a difference in adhesion between the relief-forming layer 14 and the reflective layer 16, i.e., interfacial adhesive strength, between the island regions R1 and the sea regions R2. As described above, many resins generally have low surface wettability and poor adhesion to other materials in their original state. Therefore, the interface between the relief-forming layer 14 and the reflective layer 16 in the sea region R2 has the lowest interfacial adhesive strength within the transfer foil 11, making it the most susceptible to separation. On the other hand, as described above, the wettability and anchor effect of the island regions R1 are improved by corona treatment, plasma treatment, or the like, and therefore the adhesion between the relief-forming layer 14 and the reflective layer 16 is strong. Therefore, in the island regions R1, cohesive failure may occur in the adhesive layer 17 as shown in Fig. 7A or in the relief-forming layer 14 as shown in Fig. 7B. The layer that separates may differ depending on the relative magnitudes of the interfacial adhesive strength and rupture strength of each layer, and delamination between the relief-forming layer 14 and the patch substrate 13 or cohesive failure in the patch substrate 13 may occur.

[0071] 7A and 7B, part of the separated transfer foil 11 remains on the protective sheet 18 side, and part on the information recording sheet 19 side. One method for fraudulently reusing the transfer foil 11 is to remove the transfer foil 11 together with the protective sheet 18 and embed it in a counterfeit card. Therefore, it is most undesirable for the separated transfer foil 11 to remain on the protective sheet 18 side while maintaining the shape of the relief structure 15; it is preferable for the shape of the relief structure 15 to be at least partially damaged, as shown in FIG. 7A.

[0072] As shown in FIG. 7B , the transfer foil 11 remaining on the protective sheet 18 maintains the shape of the reflective layer 16, which is equivalent to the shape of the relief structure 15, throughout the island regions R1 and sea regions R2. Therefore, it is theoretically possible to reproduce the optical effect of the relief structure 15 by applying a resin to the surface. However, as described above, the island regions R1 are regions with sides or diameters of 20 μm to 300 μm, and are provided along with the sea regions R2 over a wide area of ​​the transfer foil 11, as shown in FIG. 3 . Therefore, in practice, many uneven surfaces are formed by the separation or fracture surfaces of the island regions R1 and sea regions R2, as shown in FIG. 7B . When a resin is applied to such a surface with fine unevenness measuring tens to hundreds of μm, the resin may not completely penetrate the fine parts at the bottom, or air bubbles may be trapped. As a result, the optical effect cannot be reproduced due to the unfilled resin parts, and light incident on the transfer foil 11 is scattered, and even if it is reused, the optical effect of the transfer foil 11 as a whole is significantly reduced, making it easy to identify it as a fake.

[0073] By providing minute island regions R1 and sea regions R2, the interfacial adhesive strength between specific layers (between the relief-forming layer 14 and the reflective layer 16 in the first embodiment) can be changed. Therefore, when attempting to separate the transfer foil 11, different forces act on the island regions R1 and the sea regions R2 in specific layers (the relief-forming layer 14 and the reflective layer 16 in the first embodiment), and adjacent regions are influenced by each other, resulting in uneven separation or rupture forces within each region. As a result, in Figures 7A and 7B, in the sea region R2, localized spots where the relief-forming layer 14 is located on the protective sheet 18 side and spots where the reflective layer 16 is located on the information recording sheet 19 side alternate. Therefore, the separated surface of the transfer foil 11 becomes rough, and the same optical effect as before separation cannot be obtained.

[0074] (Second embodiment) Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a plan view schematically illustrating a laminate 10 according to the second embodiment. The configuration of the laminate 10 is the same as that of the first embodiment. The first and second embodiments are the same in terms of layer configuration and the fact that the interfacial adhesive strength is different between the island region R1 and the sea region R2, but the layers with different interfacial adhesive strengths are different. While the first embodiment focuses on the interfacial adhesive strength between the relief-forming layer 14 and the reflective layer 16, the second embodiment focuses on the interfacial adhesive strength between the reflective layer 16 and the adhesive layer 17.

[0075] There are three known mechanisms by which adhesives and adherends (materials to be bonded) adhere to each other: mechanical adhesion, chemical adhesion, and physical adhesion. The characteristics of each of the three adhesion mechanisms are explained below.

[0076] Mechanical adhesion occurs when an adhesive is applied to an adherend that has many small pores on its surface, and the adhesive penetrates the pores and hardens, forming a bond that prevents it from coming out. This is also known as the anchoring effect, fastener effect, etc. Porous materials can be paper, wood, or fibers, but they can also be etched or chemically treated metal surfaces.

[0077] Chemical adhesion occurs when functional groups on the surface of the adherend bond with functional groups on the adhesive through chemical bonds. These chemical bonds are known as primary bonds, and include covalent bonds and ionic bonds, which are expected to have the strongest bonding strength.

[0078] Physical adhesion occurs when polar molecules electrically attract each other, creating intermolecular forces. This physical bond is also known as a secondary bond, and the stronger the polarity, the stronger the bond. Examples of intermolecular forces include hydrogen bonds and van der Waals forces. Hydrogen bonds are the force by which highly electronegative atoms attract highly polar hydrogen atoms and are generally stronger than van der Waals forces. On the other hand, there are three types of van der Waals forces: orientation forces (forces resulting from charge imbalances between polar molecules), induction forces (forces resulting from polar molecules inducing dipoles in nonpolar molecules), and dispersion forces (forces resulting from momentary charge imbalances between all molecules). These forces only work when the molecules on the adherend surface and the adhesive molecules are very close to each other; it is said that a distance of 3-5 Å or less is required to achieve strong intermolecular forces. Ordinary adhesives have a high viscosity, and simply applying them does not allow the adhesive to penetrate into the fine irregularities on the surface of the adherend material, so measures are taken such as applying pressure or heat when applying, or diluting the adhesive with a solvent and applying it as a primer to make the irregularities shallower.In addition, it is possible to make intermolecular forces act by increasing the affinity, or wettability, between the two materials.

[0079] It is known that the actual mechanism of adhesion is not just one of the three adhesion mechanisms mentioned above, but a combination of these adhesion mechanisms. Among these, the influence of physical adhesion is particularly large.

[0080] The strength of physical adhesion between the island region R1 and the sea region R2 according to the second embodiment will be described below.

[0081] (Island area / sea area) FIG. 9 is a partial cross-sectional view taken along line 2A-2A in FIG. 8, showing the reflective layer 16 and adhesive layer 17 corresponding to the island region R1 and sea region R2. The wettability between the reflective layer 16 and adhesive layer 17 differs between the island region R1 and sea region R2. In FIG. 9, this is schematically shown by the presence or absence of a dashed line at the interface between the two. As described above, wettability is a property that contributes to intermolecular forces, so differences in wettability result in differences in adhesive force. In the second embodiment, the wettability between the reflective layer 16 and adhesive layer 17 in the island region R1 is higher than that in the sea region R2. Factors that determine wettability between a solid and a liquid are described below.

[0082] 10A to 10C are cross-sectional views that schematically illustrate the shape of a liquid dropped onto a solid surface. As shown in FIG. 10A, when a solid surface is in contact with a liquid and a gas, the surface tensions γS and γL of the solid and liquid, respectively (the former is called the "surface free energy"), and the interfacial tension γLS between the solid and liquid act at the boundary where these three phases meet. Wettability is determined by the balance between these, and this relationship is known as Young's equation, shown below.

number

[0083] Here, θ is the angle formed between the solid surface and the surface of the liquid dropped on the solid surface, which is called the contact angle. Generally, it is said that the smaller the surface tension γL and the larger the surface free energy γS, the higher the wettability. However, as the above formula shows, it is not only the wettability of the liquid and solid alone that is affected, but also by the compatibility between the liquid and solid, that is, the interfacial tension γLS between them.

[0084] Surface tension and surface free energy are composed of the sum of four components of intermolecular forces: dispersion, orientation, inductive, and hydrogen bonding forces: dispersion, polar, inductive, and hydrogen bonding. Of these, the inductive component is so weak that it can be ignored, and the hydrogen bonding component is often lumped together with the polar component. The closer the ratio of dispersion and polar components of the solid and liquid, the lower the interfacial tension γLS between the solid and liquid (the higher the affinity).

[0085] The wettability of a solid and a liquid can be quantitatively determined by the contact angle θ shown in Figures 10A to 10C. Figures 10A to 10C show three examples of different contact angles θ. Within the range of 0 to 180°, the closer the contact angle θ is to 0°, the higher the wettability, and the closer it is to 180°, the lower the wettability. In other words, the example shown in Figure 10A shows the highest wettability, with the droplet wetting and spreading on the solid. On the other hand, the example shown in Figure 10C shows the lowest wettability, with the droplet not spreading on the solid and maintaining its original shape. In the example shown in Figure 10B, the degree to which the droplet wets and spreads on the solid is intermediate between the examples shown in Figures 10A and 10C. If a solid surface is easily wetted by water, the solid is said to be hydrophilic. Conversely, if it repels water, the solid is said to be water-repellent. Hydrophilicity can be defined as a contact angle θ<90°, and water repellency can be defined as a contact angle θ≧90°. Furthermore, a contact angle θ<10° can be defined as superhydrophilicity, and a contact angle θ≧150° can be defined as superhydrophobicity. For example, glass and metal oxide-based materials have a contact angle θ<90°, carbon and silica-based materials have a contact angle θ=90°, and Teflon (registered trademark) and fluorine-based materials have a contact angle θ>90°.

[0086] Now, if we transform Equation 1, we get Equation 2.

number

[0087] From the above equation (2), the method for increasing wettability, i.e., for bringing the contact angle θ closer to 0°, can be either a method for reducing the surface tension γ_L of the liquid or a method for increasing the surface free energy γS of the solid. One method for reducing the surface tension of the liquid is to add a surfactant to the liquid. One method for increasing the surface free energy γS of the solid is to chemically or physically modify the solid surface to increase wettability. In the second embodiment, local surface modification of the reflective layer 16 will be described as an example.

[0088] Physical modification of a solid surface specifically means roughening the surface, a process that is necessary in conjunction with chemical hydrophilization to achieve superhydrophilicity and superhydrophobicity. The Wenzel model and the Cassie-Baxter model are known as models that describe the relationship between microscopic surface irregularities and wettability. The former assumes that droplets penetrate into the concave parts of the irregularities and wet the entire solid surface, and is based on the idea that the surface area of ​​the interface between the solid and the droplet increases r times due to the irregularities, and is expressed as the following equation (3): where θw is the apparent contact angle on the irregular surface.

[0089]

number

[0090] In this equation (3), since r>1, a hydrophilic surface becomes more hydrophilic, and a water-repellent surface becomes more water-repellent due to surface roughening.

[0091] In contrast, the Cassie-Baxter model assumes that the droplets do not penetrate into the concave portions of the unevenness, but that air instead fills in. Although we will not go into detail here, the theory is that the presence of unevenness on a solid surface reduces the actual contact area between the droplet and the solid surface, resulting in a larger contact angle with the droplet compared to a case where there is no unevenness, and is thought to be effective in creating water-repellent solid surfaces.

[0092] Which of the above models applies depends on the size of the droplet, the uneven shape of the solid surface, and the wettability of the material. However, it has been reported that the Wenzel model prevails when the size or weight of the droplet is increased, thereby increasing the pressure to penetrate into the depression.

[0093] As mentioned above, hydrophilicity and water repellency are evaluated using contact angle, which can be measured using either static or dynamic contact angle measurements. Static contact angle measurements are used to determine only the contact angle, and include the commonly used sessile drop method, as well as other methods such as the Vr method for measuring large sample surfaces and the extremely small drop method using an extremely small contact angle meter. Dynamic contact angle measurements are used to determine the droplet's speed and adhesive force, and include the sliding method, expansion / contraction method, and Wilhelmy method. With advances in software-based image analysis technology, the Young's method and ellipse method, which provide more accurate measurements, are now common.

[0094] A method for increasing the wettability of the island regions R1 on the surface of the reflective layer 16 compared to the sea region R2 is described below. As mentioned previously, methods for changing the wettability of solid surfaces include chemical or physical modification. As an example of chemical modification, consider the case where the reflective layer 16 is made of silicon oxide. Silicon oxide has silanol groups (≡Si-OH) covered with hydroxyl groups on its surface, making it hydrophilic. The hydroxyl groups form hydrogen bonds, the strongest intermolecular force, with the hydroxyl groups (-OH) of the adhesive, water (HOH), oxygen (O), nitrogen (N), carboxyl groups (-COOH), and carbonyl groups (C=O), resulting in strong bonds. The hydroxyl groups on the hydrophilic silica surface can be hydrophobized by substituting them with methylsilane or other agents. Examples of surface treatment agents for hydrophobization include polydimethylsiloxane, methylchlorosilane, and hexamethyldisilazane. By selectively subjecting the sea region R2 to hydrophobic treatment while maintaining the hydrophilicity of the island region R1, the wettability (contact angle) of the two regions can be changed.

[0095] The reflective layer 16 may also be made of titanium dioxide (TiO2). Titanium dioxide is easily wetted by oil (oleophilic) but not easily wetted by water (hydrophobic). However, titanium dioxide is known to become hydrophilic when irradiated with UV light in the presence of oxygen, and is therefore used as a photocatalyst in various fields. The mechanism is thought to be that holes generated by UV irradiation on the titanium dioxide surface break the chemical bond between titanium and oxygen atoms (Ti-O-Ti), which then reacts with water to form hydroxyl groups. The titanium dioxide surface becomes superhydrophilic immediately after light irradiation, but when UV irradiation is stopped and the surface is left in a dark place, it gradually returns to its original surface state and loses its hydrophilicity. When the reflective layer 16 is made of titanium dioxide, after forming the reflective layer 16, UV irradiation can be performed on only the island regions R1 while physically covering the sea regions R2, making the island regions R1 hydrophilic and the sea regions R2 hydrophobic. In this case, it is necessary to apply the adhesive layer 17 before the hydrophilicity is lost as described above.

[0096] Furthermore, when the reflective layer 16 is made of aluminum, the metal surface is covered with an oxide layer, onto which water and other contaminants are adsorbed. Therefore, sufficient adhesion cannot be achieved in its current state, so surface treatment is preferable. Surface treatments include (1) removing contaminants using organic solvents or ultraviolet light, (2) forming an oxide film suitable for adhesion using acid or alkali treatment, and (3) applying a silane coupling agent. By performing such surface treatments only on the island regions R1 described in the first embodiment, it is possible to increase the wettability of the island regions R1 compared to the sea regions R2.

[0097] (relief structure) The relief structure 15 will now be described. 6A to 6F, the relief structure is the same as that of the first embodiment described with reference to Figures 6A to 6F, and therefore will not be described again. However, the second embodiment differs from the first embodiment in that the first relief region SR1 overlaps the island region R1, and the second relief region SR2 overlaps the sea region R2.

[0098] If an attempt is made to destroy the laminate 10 and remove the transfer foil 11 by fraudulent means, delamination will occur between layers with low interfacial adhesive strength in the laminate 10, or cohesive failure will occur within a layer with low breaking strength, resulting in separation of the transfer foil 11. The following explanation will be given on the assumption that the interfacial adhesive strength between the patch substrate 13 and the information recording sheet 19 and the interfacial adhesive strength between the adhesive layer 17 and the protective sheet 18 are greater than the interfacial adhesive strength between the protective sheet 18 and the information recording sheet 19.

[0099] As explained above, the fine irregularities contribute to wettability and, ultimately, adhesive strength, and the relief structure 15 in the second embodiment also has this effect. However, if the chemical bonding state between adjacent layers is the same, it is expected that the force resisting peeling will be different between a structure that is parallel to the direction in which a peel force is applied and a structure that is not. This can also be expressed as a difference in the anchoring effect of the relief structure 15.

[0100] In the second embodiment, linear first relief structures 15a aligned in one direction are arranged in the island regions R1, where the reflective layer 16 and the adhesive layer 17 have higher wettability and higher interfacial adhesive strength than the sea regions R2. Therefore, when attempting to peel the transfer foil 11 from the laminate 10 particularly along the first direction, separation is likely to occur at the interface between the relief-forming layer 14 and the reflective layer 16, where the adhesive strength of the first relief structures 15a, i.e., the anchor effect, is weak. On the other hand, in the sea regions R2, the anchor effect of the second relief structures 15b increases the interfacial adhesive strength between the relief-forming layer 14 and the reflective layer 16 compared to the case of the first relief structure 15a, and separation is likely to occur between the reflective layer 16 and the adhesive layer 17, where the interfacial adhesive strength is weak.

[0101] When separated, if the adhesive layer 17 and the protective sheet 18 are in contact with each other (see FIG. 2A), the relief-forming layer 14 remains on the information recording sheet 19 side. If the adhesive layer 17 and the information recording sheet 19 are in contact with each other (see FIG. 2B), the relief-forming layer 14 remains on the protective sheet 18 side. In the former case, to illegally reuse the separated transfer foil 11, it is necessary to separate the relief-forming layer 14 from the information recording sheet 19. However, since the relief-forming layer 14 and the patch substrate 13 combined are significantly thinner, only a few micrometers thick compared to the information recording sheet 19 (thickness: 50 μm to 800 μm), it is difficult to separate the relief-forming layer 14 from the information recording sheet 19 without destroying the relief structure 15, making reuse difficult. On the other hand, in the latter case, the relief structure 15 remains on the protective sheet 18 side, and therefore, depending on its surface condition, it may be illegally reused. Specifically, if the island region R1 and the sea region R2 are peeled cleanly at the interface between the relief forming layer 14 and the reflective layer 16, and at the interface between the reflective layer 16 and the adhesive layer 17, respectively, the shape of the relief structure 15 will be maintained on the separated surface, although the presence or absence of the reflective layer 16 will differ, and therefore it may be possible to reuse it.

[0102] As described in the first embodiment, the island regions R1 are minute regions with sides or diameters of 20 μm to 300 μm, and are provided scattered throughout the sea region R2 over a wide area of ​​the transfer foil 11, as shown in FIG. 8 . When attempting to separate the transfer foil 11, the forces acting on the island regions R1 and sea regions R2 in specific layers (the reflective layer 16 and adhesive layer 17 in the second embodiment) are different, and adjacent regions are significantly influenced by each other, resulting in uneven separation or rupture forces within each region. As a result, the reflective layer 16 may be locally removed to the protective sheet 18, or the adhesive layer 17 may be locally removed to the information recording sheet 19, resulting in a rough surface on the separated transfer foil 11, and the same optical effect as before separation may not be achieved.

[0103] Even if the relief structure 15 is neatly maintained on the separated surface, the presence or absence of the reflective layer 16 is different. Therefore, if the separated transfer foil 11 and the protective sheet 18 are used as is on a counterfeit card, the optical effect of the island region R1 where the reflective layer 16 is lost will not be exhibited, making it easy to identify the counterfeit from its appearance. Furthermore, even if an attempt is made to reproduce the optical effect of the island region R1 by adding a reflective layer to the relief structure 15 side of the separated transfer foil 11, the difference in the thickness of the reflective layer between the island region R1 without the reflective layer 16 and the sea region R2 where the reflective layer 16 remains will result in unevenness in the optical effect, reduced brightness, and other problems, making it difficult to perfectly reproduce the original state. In particular, if the reflective layer 16 is made of a light-transmitting material, if the refractive index of the original material and the material of the newly added reflective layer do not have the same refractive index, two reflective layers will essentially be formed in the sea region R2, resulting in multilayer film interference and producing an optical effect different from that of the island region R1. This can result in changes such as a different color than in a single layer or reduced brightness.

[0104] In the second embodiment, by making the interfacial adhesive strength between the reflective layer 16 and the adhesive layer 17 different in the island region R1 and the sea region R2, even if an attempt is made to remove the transfer foil 11 from the laminate 10 and reuse it illegally, the original optical effect cannot be reproduced, thereby acting as a deterrent to such acts, or even if it is reused, it can be easily identified as a fake.

[0105] (Third embodiment) (Laminate) Hereinafter, a third embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a plan view schematically illustrating a laminate 10 according to a third embodiment. Similar to the first and second embodiments, the laminate 10 includes a transfer foil 11 displaying an image 12. FIG. 12 is a cross-sectional view taken along line AII-AII in FIG. 11. The laminate 10 includes a patch substrate 13, a relief-forming layer 14, a first reflective layer 161, a second reflective layer 162, and an adhesive layer 17 laminated in this order. A relief structure 15 is formed on the surface of the relief-forming layer 14. The first reflective layer 161 is provided in a concave-convex shape conforming to the relief structure 15, and the second reflective layer 162 is provided in a concave-convex shape conforming to the first reflective layer 161. The transfer foil 11 includes at least the above layers in the order listed, but may include other layers. The transfer foil 11 is laminated between a protective sheet 18 and an information recording sheet 19, which are enclosed within the laminate 10 to prevent the transfer foil 11 from being exposed to the outside. 12A and 12B show the layer configuration of the transfer foil 11 placed inside the laminate 10 reversed, but either configuration is acceptable. In the configuration of Fig. 12A, the transfer foil 11 is transferred to the protective sheet 18 via the adhesive layer 17 and then laminated. On the other hand, in the configuration of Fig. 12B, the transfer foil 11 is transferred to the information recording sheet 19 via the adhesive layer 17 and then laminated.

[0106] (Island area / sea area) The following describes the first region S1, the second region S2, and the relief structure 15 that make up the laminate 10. Fig. 13 is a plan view showing the configuration of the transfer foil 11. The transfer foil 11 has a first region S1 and a second region S2. In the example shown in the figure, the first region S1 and the second region S2 extend over the entire surface of the transfer foil, but they may also be provided in a part of the transfer foil 11.

[0107] 14 is a partial cross-sectional view taken along line 3A-3A in FIG. 13 and shows the relief-forming layer 14, first reflective layer 161, second reflective layer 162, and adhesive layer 17 corresponding to the first region S1 and the second region S2. The first region S1 has a configuration in which two layers, the first reflective layer 161 and the second reflective layer 162, are stacked, while the second region S2 has only the first reflective layer 161. In addition, at least one of the first reflective layer 161 and the second reflective layer 162 is made of an optically transparent material having a higher refractive index than the relief-forming layer 14 and the adhesive layer 17 at a typical wavelength in the visible light range, for example, 532 nm. This provides a higher reflection effect than when the refractive indexes of the first reflective layer 161 and the second reflective layer 162 are both lower than the relief-forming layer 14 and the adhesive layer 17, making it easier for a viewer to view the image 12 displayed as an optical effect in both the first region S1 and the second region S2.

[0108] 14 , when the interfacial adhesive strength between the first reflective layer 161 and the adhesive layer 17 is T1 and the interfacial adhesive strength between the second reflective layer 162 and the adhesive layer 17 is T2, T1 and T2 are different. More specifically, when T1 is greater than T2, the second region S2 corresponds to the island region R1, and the first region S1 corresponds to the sea region R2. On the other hand, when T1 is smaller than T2, the first region S1 corresponds to the island region R1, and the second region S2 corresponds to the sea region R2. While FIGS. 13 and 14 show an example in which T1 is smaller than T2, the first region S1 corresponds to the island region R1, and the second region S2 corresponds to the sea region R2, as described above, the correspondence between the first region S1 and the second region S2 and the island region R1 and the sea region R2 may change depending on the relationship between the interfacial adhesive strengths T1 and T2.

[0109] The configuration of the transfer foil 11 is not limited to that shown in FIG. 14 and may be an embodiment as shown in FIG. 15. In the example of FIG. 15, the first region S1 is configured by laminating a first reflective layer 161 and a second reflective layer 162, while the second region S2 is different from the example shown in FIG. 14 in that only the second reflective layer 162 is provided. In this case, in both the first region S1 and the second region S2, the second reflective layer 162 contacts the adhesive layer 17, but the layer in contact with the relief-forming layer 14 is different. More specifically, in the first region S1, the first reflective layer 161 contacts the relief-forming layer 14, and in the second region S2, the second reflective layer 162 contacts the relief-forming layer 14. The first reflective layer 161 does not have to be made of a light-transmitting material and may be made of a metal material. Examples of metal materials include aluminum and silver.

[0110] 15, when the interfacial adhesive strength between the first reflective layer 161 and the relief forming layer 14 is T1 and the interfacial adhesive strength between the second reflective layer 162 and the relief forming layer 14 is T2, T1 and T2 are different. When T1 is larger than T2, the second region S2 corresponds to the island region R1, and the first region S1 corresponds to the sea region R2. On the other hand, when T1 is smaller than T2, the first region S1 corresponds to the island region R1, and the second region S2 corresponds to the sea region R2.

[0111] 14 and 15, the interfaces where the difference in interfacial adhesive strength occurs are different between the first region S1 and the second region S2. However, in the island region R1 and the sea region R2, the difference in interfacial adhesive strength that occurs between the reflective layers 161, 162 and the adhesive layer 17 or between the reflective layers 161, 162 and the adhesive layer 17 or the relief forming layer 14 is caused by the materials of the first reflective layer 161 and the second reflective layer 162. This will be explained below.

[0112] (reflective layer) Three examples of methods for creating a difference in interfacial adhesive strength between the island regions R1 and the sea regions R2 as described above, i.e., the characteristics of the first reflective layer 161 and the second reflective layer 162, are shown below. Note that the methods are not limited to the three listed below, and any mechanism can be used as long as the reflective layers 161 and 162 are capable of creating a difference in interfacial adhesive strength. In the following explanation, the interfacial adhesive strength between the reflective layers 161 and 162 and the adhesive layer 17 will be described using the configuration of FIG. 14 as an example, but in the case of the configuration of FIG. 15, the "adhesive layer 17" can be replaced with the "relief-forming layer 14."

[0113] As an example, a configuration will be described in which the first region S1 corresponds to the sea region R2 and the second region S2 corresponds to the island region R1. In the first region S1, the second reflective layer 162 (first reflective layer 161 in the configuration of Figure 15) is made of a water- or oil-repellent inorganic compound. If the surface of the adhesive layer 17 in contact with the second reflective layer 162 is hydrophilic, a water-repellent material should be selected; if it is oil-repellent, an oil-repellent material should be selected. Alternatively, a material with both properties may be used. Furthermore, if the adhesive layer 17 has both hydrophilic and oil-repellent properties, either a water-repellent or oil-repellent material may be used, but it is preferable to select the material that results in the lowest interfacial adhesive strength between the second reflective layer 162 and the adhesive layer 17. The water- and oil-repellent material can be a fluorine-based compound. An example of a fluorine-based compound is magnesium fluoride (MgF2). By using a water-repellent / oil-repellent material for the second reflective layer 162, the adhesion between the second reflective layer 162 and the adhesive layer 17, i.e., the interfacial adhesive strength, is reduced in the first region S1 (sea region R2). On the other hand, in the second region S2, which includes a material that has a high affinity with the adhesive layer 17, the interfacial adhesive strength between the first reflective layer 162 and the adhesive layer 17 is greater than in the first region S1 (island region R1). As shown in FIG. 14, when the first reflective layer 161 and the second reflective layer 162 are formed on the relief forming layer 14, there is a concern that the second reflective layer 162 may not adhere sufficiently to the first reflective layer 161, resulting in the layer not being formed. However, this problem can be solved by forming the first reflective layer 161 and the second reflective layer 162 by successive vapor deposition in a vacuum environment.

[0114] As another example, the first region S1 will be described as an island region R1, and the second region S2 as a sea region R2. In this example, the surface of the second reflective layer 162 that contacts the adhesive layer 17 is surface-modified. This can increase the interfacial adhesion strength between the second reflective layer 162 and the adhesive layer 17. Surface modification can include, as described in the first and second embodiments, 1) improving hydrophilicity or removing organic matter or oxide film from the object surface using corona treatment or plasma treatment, 2) adding functional groups that enable bonding with the adhesive layer 17, and 3) roughening to enhance the anchoring effect. Meanwhile, the first reflective layer 161 is an inorganic compound that has a lower interfacial adhesion strength with the adhesive layer 17 than the second reflective layer 162 after surface modification. The lower interfacial adhesion strength may be due to the properties of the material itself, such as wettability with the adhesive layer 17 or differences in intermolecular forces with the adhesive layer 17, or an oxide film that naturally forms on the surface.

[0115] For convenience of explanation, an example will be described below in which the first region S1 corresponds to the island region R1 and the second region S2 corresponds to the sea region R2. However, the first region S1 may correspond to the sea region R2 and the second region S2 may correspond to the island region R1. In this example, the difference in interfacial adhesion strength between the reflective layers 161, 162 and the adhesive layer 17 is caused by the difference in the bonding force between each reflective layer and the adhesive layer 17. Of the bonding mechanisms described in the second embodiment, attention is particularly focused on physical and chemical bonding, and it is assumed that the first reflective layer 161 and the second reflective layer 162 differ in wettability (or contact angle) with respect to the adhesive layer 17 and the presence or magnitude of bonding forces (intermolecular forces, ionic bonding forces, covalent bonds, hydrogen bonds) acting between the two layers. When the adhesive layer 17 is made of an oleophilic material, by making the first reflective layer 161 an oleophobic material and the second reflective layer 162 an oleophilic material, it is possible to create a difference in the interfacial adhesive strength between the reflective layers 161, 162 and the adhesive layer 17 in the first region S1 and the second region S2. Furthermore, the above characteristics can also be achieved by using materials that bond the first reflective layer 161 and the adhesive layer 17 by ionic bonding and the second reflective layer 162 and the adhesive layer 17 by intermolecular forces.

[0116] The above-described method makes it possible to make the interfacial adhesive strength between the reflective layers 161 and 162 and the adhesive layer 17 different between the first region S1 and the second region S2. This configuration makes it possible to predict that, in the event of an unauthorized attempt to remove the transfer foil 11 from the laminate 10, in the island region R1, where the interfacial adhesive strength between the layers is high, separation will occur between the patch substrate 13 or the relief-forming layer 14, or cohesive failure will occur between these two or within the adhesive layer 17. On the other hand, in the sea region R2, where the interfacial adhesive strength is low, separation will likely occur between the reflective layer (161 or 162) and the adhesive layer 17. As a result, the layers that separate or break are different between the island region R1 and the sea region R2. Therefore, the relief structure 15 will not appear on one of the separated surfaces of the two separated transfer foils 11, with its shape completely maintained. This makes it possible to prevent reuse.

[0117] (image) The configuration of the image 12 will be described below. The configuration of the image 12 can be applied to any of the first to third embodiments described above. In the transfer foil 11, the image 12 displayed as an optical effect of the relief structure 15 may be one type of motif, or two types of motifs observable at different angles. FIG. 16 shows how, when light from a light source is incident on the transfer foil 11, the relief structure 15 formed in the island region R1 and the sea region R2 reflects light at a specific angle to form a first motif 121. As long as the relief structure 15 forms the first motif 121 at a specific angle, it may have a uniform design with the same period, height, shape, orientation, etc. throughout the entire area, regardless of the island region R1 or the sea region R2. Alternatively, one or more of these design features may be locally different within the first motif 121. In the latter case, the design may be different between the island region R1 and the sea region R2. In the case of a configuration such as that shown in Figure 16, in an embodiment of the present invention, if an attempt is made to illegally remove the transfer foil 11 from the laminate 10, separation will occur in different layers between the island region R1 and the sea region R2 as described in the first to third embodiments, or destruction will occur within the layer, and the relief structure 15 will not be fully maintained in the separated transfer foil 11, the optical effect (e.g., brightness and color) of the first motif 121 will be weakened, and the original visual effect will not be obtained even if the transfer foil 11 is reused.

[0118] FIG. 17 shows how, when light from a light source is incident on the transfer foil 11, the first relief structure 15a formed in the island region R1 reflects the light at a specific angle α to form a first motif 121, and the second relief structure 15b formed in the sea region R2 reflects the light at a specific angle β different from α to form a second motif 122. The first relief structure 15a and the second relief structure 15b do not necessarily have to be limited to the island region R1 and the sea region R2, respectively. However, this configuration is preferable because it significantly weakens the optical effect of either the first motif 121 or the second motif 122 when attempting to remove the transfer foil 11 from the laminate 10. This makes it easy to identify a counterfeit product even if the separated transfer foil 11 is reused. The first relief structure 15a and the second relief structure 15b may be selected from the structures described in FIG. 6, or any structure may be used as long as the angle of reflected light α ≠ β is satisfied.

[0119] The first relief structure 15a and the second relief structure 15b can be subwavelength gratings, with the former being a subwavelength grating and the latter being a directional scattering structure. In this configuration, the first motif 121 can be a chromatic image, and the second motif 122 can be an achromatic image. The chromatic colors produced by the subwavelength grating are generated when the reflective layer 16 has a higher refractive index than the relief-forming layer 14 and the adhesive layer 17. The grating period, orientation, and refractive index of the reflective layer 16 can display colors in the direction of specular reflection. Examples of directional scattering structures include those shown in Figure 6C. When the grating direction is uniform, an achromatic image with a specific gradation is displayed. When the grating direction changes locally according to the shading of the motif, a three-dimensional achromatic image with shading, like a painting, is displayed.

[0120] The correspondence between the island regions R1 and the sea regions R2 and the first relief structure 15a and the second relief structure 15b may be different from the correspondence described above. However, when a subwavelength grating is used for the first relief structure 15a, it is preferable that the shape of the subwavelength grating is not maintained on the surface of the transfer foil 11 remaining on the protective sheet 18 side when attempting to remove the transfer foil 11 from the laminate 10, because this will result in a loss of chromatic color development due to the subwavelength grating, thereby providing a greater deterrent effect against unauthorized reuse.

[0121] 16 , the use of a subwavelength grating in the relief structure 15 reduces the color of the first motif 121 when the transfer foil 11 is removed, thereby effectively preventing unauthorized use of the transfer foil 11.

[0122] 18 and 19 are schematic diagrams illustrating the appearance of a card 20 having the laminate shown in FIGS. 16 and 17 when observed by an observer, and the visual appearance at that time. As shown in FIG. 18, the observer observes card 20 at an angle that allows the observer to capture light that is incident on card 20 from a light source and reflected from card 20. In the configuration of FIG. 16, first motif 121 is observed in state A, where card 20 is tilted at angle θ1 with respect to horizontal plane Ph1. On the other hand, in the configuration of FIG. 17, first motif 121 is observed in state A, and second motif 122 is observed in state B, where card 20 is further tilted at angle θ2 from horizontal plane Ph1. Note that, in the latter case, with card 20 in which states A and B can be observed, the example of FIG. 18 illustrates the action of tilting card 20 back and forth relative to the observer, but the action is not limited to this. Depending on the reflection direction of the first and second relief structures (15a, 15b) forming the first motif 121 and the second motif 122 and the direction in which the desired optical effect appears, states A and B may be observed by another operation, such as rotating the medium by 90 degrees from state A. Also, in the example of Fig. 18, card 20 is observed under the condition that light from the light source is incident perpendicularly to horizontal plane Ph1, but the light source does not necessarily have to be in this positional relationship, and card 20 may be observed under the condition that light is incident obliquely to horizontal plane Ph1.

[0123] (card) FIG. 20 shows an example of a card 20 incorporating the transfer foil 11 described in the first to third embodiments. The card 20 is described in Japanese Patent Application No. 2021-095146 as a medium or personal information medium 20. A schematic diagram of the card 20 is shown. The card 20 may be an identification card, ID card, driver's license, or the like. The card 20 may also be a data page of a passport or visa with a similar configuration. The card 20 may also be a tag or gift card. Identification information is recorded on these cards. The identification information is described as personal information in Japanese Patent Application No. 2020-132592, Japanese Patent Application No. 2021-067112, and Japanese Patent Application No. 2021-095146. The identification information may be biometric information, a hash value of a biometric feature, a name, an ID number, a code, or the like. Examples of biometric information include a facial image and a signature. The hash value of a biometric feature may be a hash value of data on features of a face, fingerprint, iris, or vein. The code can be a barcode or a two-dimensional code. The code may be a cryptographic code. The code may include an error correction code. An example of a two-dimensional code is QR Code (registered trademark). By attaching a transfer foil 11 having a relief structure so that it overlaps at least a portion of the personal information, it is possible to prevent tampering with the individual information.

[0124] Figure 21 shows a cross-sectional view taken along line BI-BI in Figure 20. As shown in Figure 21, card 20 has a structure in which a support layer 21 that reinforces laminate 10 is laminated on the side of laminate 10 that contacts information recording sheet 19. The above-mentioned identification information can be recorded on information recording sheet 19 with a laser beam as a modified zone 22. Support layer 21 can be white. Part or all of support layer 21 may be a color other than white.

[0125] In the card 20, the support layer 21 may have a printed body 23 on the surface that contacts the information recording sheet 19. The printed body 23 can be formed by printing ink. In the example shown in the figure, the card 20 has a front surface 20a and a back surface 20b, and has a modified zone 22 and some information indicated by the printed body 23. In the case of a card that has information only on the front surface 20a, some or all of the layers shown on the back surface 20b can be omitted.

[0126] (Laminate material) The materials for each layer are described below. The protective sheet 18 must be transparent to the visible light wavelength range or the wavelength of observation light. This allows the optical effect of the transfer foil 11 and the identification information recorded on the information recording sheet 19 to be viewed or photographed from the protective sheet 18 side. The material of the protective sheet 18 can be a thermoplastic plastic. The thermoplastic plastic is preferably one with a base material of polycarbonate or amorphous copolyester.

[0127] The thickness of protective sheet 18 is preferably 50 μm or more and 800 μm or less. If protective sheet 18 is thinner than 50 μm, the physical strength is insufficient and handling becomes difficult. On the other hand, if protective sheet 18 is thicker than 800 μm, the effects of thickness variation and deflection become greater when processing protective sheet 18, making processing difficult.

[0128] When irradiated with a laser beam having a specific wavelength, the information recording sheet 19 absorbs the laser beam, causing the material to change. This change can be foaming, carbonization, discoloration, or a combination of these phenomena. Information can be recorded on the information recording sheet 19 by changing the material's properties when irradiated with a laser beam whose intensity and irradiation spot size are adjusted within a certain range. The laser that records the information can be a solid-state laser. An example of a solid-state laser is a semiconductor laser. The laser can be a pulsed laser. The wavelength of the laser beam can be single wavelength or multi-wavelength. The information recorded on the information recording sheet 19 can be identification information. Identification information can be personal information or attribute information. Examples of personal information include the owner's name, owner's date of birth, owner's signature, and owner's portrait. Examples of attribute information include gender, nationality, and affiliation. The material of the information recording sheet 19 can be polycarbonate to which an energy absorber that absorbs the laser beam that records the information has been added. In this type of information recording sheet 19, the polycarbonate is modified by the heat generated by absorbing the laser beam. This modification can be carbonization or foaming. A specific example of the information recording sheet 19 is SD8B94, part of the LEXAN series (registered trademark) from SABIC.

[0129] In addition to the polycarbonate, polyvinyl chloride and amorphous copolyester may also be used as the material for the information recording sheet 19. Among these, polycarbonate is more likely to improve the durability of the information recording sheet 19 and the contrast when the color is developed compared to when other materials are used.

[0130] The thickness of the information recording sheet 19 is preferably 50 μm or more and 800 μm or less. If the thickness of the information recording sheet 19 is thinner than 50 μm, the insufficient thickness results in insufficient color development, resulting in poor contrast between the colored and uncolored areas. On the other hand, if the thickness of the information recording sheet 19 is thicker than 800 μm, transparency is impaired, resulting in a strong black appearance and poor contrast between the modified and unmodified areas.

[0131] The relief-forming layer 14 can be made of a thermoplastic resin, a thermosetting resin, or a photocurable resin. These synthetic resins include polyester, polyurethane, polyacrylate, acid-modified polyolefin, ethylene-vinyl acetate copolymer resin, polyimide, polyethylene, polypropylene, polymethyl methacrylate, polystyrene, polycarbonate, polyamide, polyamideimide, cyclic polyolefin, melamine, inorganic particles, epoxy resin, and cellulose resin, as well as mixtures, composites, and copolymers of these materials. Among the above materials, polymethyl methacrylate, acid-modified polyolefin, and melamine have excellent formability. The relief-forming layer 14 is not limited to a single layer; multilayer structures are also possible. The multilayer relief-forming layer 14 can be a laminate of a thermosetting resin and a thermoplastic resin. The thermoplastic resin can be a resin containing polymethyl methacrylate or acid-modified polyolefin. Alternatively, the multilayer relief-forming layer 14 can include layers of thermoplastic resins with different physical properties. Alternatively, the relief-forming layer 14 may contain inorganic powder or polymer powder. The inclusion of the powder makes it possible to adjust the interfacial adhesion strength between the relief-forming layer 14 and the patch substrate 13. Therefore, the relief structure 15 side of the relief-forming layer 14 may be a layer of a curable resin, and the opposite side may be a layer of a thermoplastic resin containing an inorganic powder or a polymer powder. In the laminate 10, the relief-forming layer 14 may contain a resin having a higher melting point than polycarbonate.

[0132] The material of the protective sheet 18 can include at least one substance from a second group of substances consisting of polyurethane, polymethyl acrylate, polyester, acid-modified polyolefin, and ethylene-vinyl acetate copolymer resin.

[0133] The material of the reflective layer 16 can be a metal or a dielectric; in the former case, it can be a masking reflective layer, and in the latter case, it can be a light-transmitting reflective layer. Examples of metals include aluminum and silver. The dielectric can be a metal compound or silicon oxide. The metal compound can be a metal oxide, a metal sulfide, or a metal fluoride. Examples of metal compounds are zinc oxide, titanium oxide, niobium oxide (NbO2), and zinc sulfide. When the reflective layer 16 is composed of two layers, a first reflective layer 161 and a second reflective layer 162, as in the third embodiment, two of the above materials can be selected; for example, the first reflective layer 161 can be silicon dioxide and the second reflective layer 162 can be titanium dioxide.

[0134] When the refractive index of the dielectric for visible light is 2.0 or more, it is easy to obtain a refractive index difference with the relief-forming layer 14, and the reflectance of reflected light generated according to the shape of the relief structure 15 is improved, making it easier for the viewer to view the image 12. The reflective layer 16 can be formed by a deposition method. The deposition method can be either a physical deposition method or a chemical deposition method, or both. The physical deposition method can be a vacuum deposition method or a sputtering method. The reflective layer 16 is preferably formed to a film thickness of 10 nm or more and 200 nm or less.

[0135] The adhesive layer 17 can be made of the same material as that used to form the relief-forming layer 14. Among these, it can contain at least one of polymethyl methacrylate, polyester, cyclic polyolefin, melamine, and ethylene-vinyl acetate copolymer resin. These materials tend to provide sufficient interfacial adhesion strength between the adhesive layer 17 and a layer containing polycarbonate that is in contact with the adhesive layer 17. Furthermore, resins having a carbonate bond (-O-CO-O-), a urethane bond (-NH-CO-), or an ester bond (-O-CO-) can be used as the material for forming the adhesive layer 17. When adhering to polycarbonate, the interfacial adhesion strength tends to be high between polycarbonate and resins having an ester bond or urethane bond, which have a structure similar to that of a carbonate bond. Furthermore, when the laminate 10 has the configuration described in the second and third embodiments, the material of the adhesive layer 17 may be selected according to the material properties of the reflective layer 16 or the properties after surface modification so that the interfacial adhesive strength between the reflective layer 16 and the adhesive layer 17 is increased by the mechanism described in the second and third embodiments. In the laminate 10, the adhesive layer 17 may contain a resin having a lower melting point than polycarbonate.

[0136] Materials for forming the support layer 21 can be polyvinyl chloride, amorphous copolyester, and polycarbonate containing a white material such as titanium oxide. The thickness of support layer 21 can be 200 μm or more and 800 μm or less. A thickness of 200 μm or more allows the chip, antenna, wiring, and other circuits included in card 20 to be hidden from an observer. Identification information may be recorded as digital data on the circuit chip included in card 20. The recorded digital data may include personal information recorded on information recording sheet 19 as identification information. The recorded digital data may be encrypted. Furthermore, a thickness of support layer 21 of 800 μm or less allows for a reduction in thickness variation and deflection of support layer 21, which helps prevent defects such as warping during lamination.

[0137] The printed body 23 can be colored. The printed body 23 may also be monochrome. Furthermore, the printed body 23 may be black. The printed body 23 may be positioned over the entire surface of the support layer 21, or letters, pictures, geometric patterns, numbers, symbols, codes, etc. may be positioned locally. The material for forming the printed body 23 can be ink. The inks described in the above-mentioned embodiments can be used as the ink. The printed body 23 may use functional ink that changes color depending on the illumination angle or observation angle of light. The inks described in the above-mentioned embodiments can be used as such functional ink. The printed body 23 formed using functional ink can improve the anti-counterfeiting resistance of the card 20.

[0138] The print 23 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, and the toner is transferred to a print substrate using static electricity generated by the charge, which is then heated and fixed to form the print 23.

[0139] In this embodiment, each layer constituting the transfer foil 11 and the protective sheet 18 may transmit a portion or all of the wavelength band of infrared light so as to transmit an infrared laser beam. The transmitted infrared light band may include the wavelength of an infrared laser. In particular, the transmitted infrared light band may include wavelengths 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 can be irradiated onto the information recording sheet 19 through the transfer foil 11, forming an altered zone 22 in the information recording sheet 19.

[0140] (Card manufacturing method) A method for manufacturing a transfer foil 11 and a card 20 equipped with the transfer foil 11 will be described using Figure 21. The transfer foil 11 is produced by laminating, in this order, a patch substrate 13, a relief-forming layer 14, a reflective layer 16 (a first reflective layer 161 and a second reflective layer 162 when the reflective layer has a two-layer structure as in the third embodiment), and an adhesive layer 17 on a carrier 24 (not shown). The reflective layer 16 can be formed by a deposition method, as described above. The deposition method can be either a physical deposition method or a chemical deposition method, or both. The physical deposition method can be a vacuum deposition method or a sputtering method. The other layers can be formed by applying a coating liquid and drying it in an oven.

[0141] In this embodiment, a relief structure 15 is formed in the relief-forming layer 14. The relief structure 15 can be obtained by applying a coating film containing a synthetic resin for forming the relief-forming layer 14, and then transferring the concave-convex shape of a stamper (embossing plate) on which the relief structure 15 is formed to the coating film.

[0142] An embossing plate for transferring the relief structure 15 to the relief-forming layer 14 can be obtained by the following method. First, a photosensitive resist is applied to one surface of a flat substrate, and then a beam is irradiated onto the photosensitive resist to expose a portion of the photosensitive resist. The photosensitive resist is then developed, thereby obtaining a master plate by photolithography. A metal stamper is then manufactured from the master plate by electroplating or the like. This metal stamper is the embossing plate, and serves as a matrix for replicating the relief structure 15 in the relief-forming layer 14. Note that metal stampers can also be obtained by cutting a metal substrate using lathe technology, but when the relief structure 15 has a complex shape or an extremely fine structure on the order of subwavelength, cutting is difficult and the stamper is therefore manufactured by the above-mentioned photolithography.

[0143] When an appropriate external force (heat, pressure, etc.) is applied from the carrier 24 side to the transfer foil 11 including the carrier 24, the adhesive layer 17 is adhered to the information recording sheet 19, and at the same time the patch substrate 13 and the carrier 24 are separated, and the transfer foil 11 consisting of the patch substrate 13 and the layers below it is transferred to the information recording sheet 19. Note that, as shown in Figures 2A and 2B, the transfer foil 11 may be transferred onto the surface of the protective sheet 18 instead of the surface of the information recording sheet 19, in which case the positional relationship of the layers is reversed.

[0144] The carrier 24 is a layer provided to hold the transfer foil 11 before transfer, and is preferably a plastic film. Specifically, it may be formed using a plastic film such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PP (polypropylene). However, the carrier 24 is preferably formed from a material that is less likely to deform or deteriorate due to external forces such as heat and pressure applied when the transfer foil 11 is supported by the carrier 24. According to this embodiment, the thickness of the carrier 24 is preferably 4 μm or more. More preferably, the thickness of the carrier 24 is 12 μm or more and 50 μm or less. If the thickness of the carrier 24 is less than 4 μm, it will be difficult to handle due to insufficient physical strength.

[0145] The transfer process uses a metal or resin stamper, with the stamper surface temperature at approximately 80°C to 150°C, the stamper contact time at 0.1 to 3 seconds, and the transfer pressure at 100 to 500 kg / cm. 2 The transfer can be performed under the following transfer conditions. By setting the temperature, contact time, and transfer pressure below their respective upper limits, it is possible to prevent excessive heat from transferring the peripheral portion of the transfer foil 11 to the transfer recipient, and to prevent excessive heat from deforming the surface of the transfer recipient. Furthermore, by setting the temperature, contact time, and transfer pressure above their respective lower limits, it is possible to prevent a portion of the transfer foil 11 from not being transferred to the transfer recipient due to insufficient adhesion of the transfer foil 11 to the transfer recipient.

[0146] The information recording sheet 19 onto which the transfer foil 11 is transferred has a support layer 21 bearing at least a printed material 23 on the surface opposite the transfer foil 11. The top and bottom surfaces of this laminate are covered with protective sheets 18, and heat and pressure are applied to the entire structure to bond all layers together, embedding the transfer foil 11 between the information recording sheet 19 and the protective sheet 18. In this bonding process, if the information recording sheet 19 and the protective sheet 18 contain polycarbonate, the temperature of the heat source that heats them can be set to 170°C or higher and 200°C or lower, and the time the heat source is in contact with them can be set to 1 minute or higher and 30 minutes or lower. This ensures reliable bonding of the information recording sheet 19 and the protective sheet 18, including polycarbonate. The layers constituting the card 20 differ depending on whether the card 20 has only a front surface 20a or also a back surface 20b, and whether each of the front surface 20a and the back surface 20b has an altered zone 22 and a printed material 23. Therefore, it is not necessary for the card 20 to include all of the layers shown in FIG. 21 .

[0147] If the transfer foil 11 is transferred to the protective sheet 18 in the transfer step, the protective sheet 18 to which the transfer foil 11 has been transferred may be covered with the information recording sheet 19 in the adhesion step.

[0148] Once the bonding process is complete, a card is formed in which all layers are integrated. A laser beam is irradiated onto the surface of this card, i.e., onto any location on the information recording sheet 19 via the protective sheet 18. This irradiation process allows for the formation of a modified zone 22 on the information recording sheet 19. The area to be irradiated is determined by the information to be displayed in the modified zone 22, and may be letters and numbers indicating personal information such as a name, date of birth, or personal identification number, or an image such as a facial image or two-dimensional code. Through the above processes, a card 20 is formed.

[0149] Hereinafter, a method for forming the island regions R1 and the sea regions R2 in the process of producing the transfer foil 11 in the first to third embodiments will be described.

[0150] One method for locally modifying the surface of the relief-forming layer 14, i.e., providing island regions R1 and sea regions R2, is to physically cover the surface of the relief-forming layer 14 with a mesh mask and then perform the surface treatment. This is the simplest manufacturing process. Alternatively, the surface treatment may be performed with a resin mask layer formed on the surface of the relief-forming layer 14, after which the mask layer is removed. If the resin used for the mask layer is water-soluble, it can be removed by washing with water. If the resin has low acid / alkali resistance, it can be removed by washing with an acid / alkali solution. However, if the latter method is used, the relief-forming layer 14 and the patch substrate 13 must be resistant to the acid / alkali solution used.

[0151] As a method for locally modifying the surface of the reflective layer 16, i.e., providing island regions R1 and sea regions R2, a surface treatment can be performed while the surface of the reflective layer 16 is physically covered with a mesh mask.

[0152] As shown in Figure 14, there are three methods for locally forming or locally removing the second reflective layer 162. The first method utilizes the orientation of the relief structure 15 and the material properties of the first reflective layer 161 and the second reflective layer 162. This method may refer to a method described in the following known document: According to Japanese Patent Application No. 2017-521701, a laminate includes a first region having a concave-convex structure extending in a first direction or in directions up to 10 degrees to the left or right of the first direction, and a second region having a concave-convex structure extending in a second direction perpendicular to the first direction or in directions up to 65 degrees to the left or right of the second direction. Two types of reflective layers, made of a first material and a second material, are deposited in this order on the surface including the concave-convex structure while being transported by a roll-to-roll method. In this patent, the first material is a material with low resistance to alkaline solutions, such as aluminum, and the second material is a material with high resistance to alkaline solutions and capable of forming columnar or void structures by oblique evaporation, such as silicon dioxide (SiOx). The first material and the second material are vapor-deposited in this order, with the film transport direction aligned with the first direction. In the first region parallel to the film transport direction, the second material forms columnar or void structures, while in the second region perpendicular to or not parallel to the film transport direction, the second material is deposited along the uneven structure with almost no voids. Due to this difference in deposition state, when a laminate consisting of the first and second materials is etched with an alkaline solution, the first and second materials are removed in the first region, while the first and second materials remain in the second region.

[0153] Using the above mechanism, the relief structure 15 may be formed by providing a grating structure (e.g., a subwavelength grating) extending in a first direction in the second region S2 and a grating structure extending in a second direction perpendicular to the first direction in the first region S1. A first reflective layer 161 is provided over the entire surface of the relief-forming layer 14 on which the relief structure 15 is formed, and then a second reflective layer 162 is provided over the entire surface of the first reflective layer 161 opposite the relief-forming layer 14. By using a material (e.g., titanium dioxide) that is more resistant to acidic and alkaline solutions than silicon oxide for the first reflective layer 161 and silicon oxide for the second reflective layer 162, when the transfer foil 11 on which the second reflective layer 162 is formed is immersed in an acidic or alkaline etching solution, the second reflective layer 162 can be removed more quickly in the second region S2, which has a larger surface area that comes into contact with the etching solution, than in the first region S1. The speed of removal and the balance between the amount of the second reflective layer 162 removed in the first region S1 and the second region S2 can be adjusted by the concentration of the etching solution, the temperature, the etching processing time, etc. This method allows the etching area to be controlled by the orientation of the relief structure 15, so etching can be performed with higher resolution and accuracy (the deviation between the etching position and the second region S2 is smaller) than the following two methods.

[0154] As a second method, after forming the first reflective layer 161 and the second reflective layer 162, a mask layer resistant to the etching solution may be provided in the first region S1, and the transfer foil 11 may be immersed in the etching solution to remove the second reflective layer 162 only in the second region S2. In this case, the etching solution may be a solution that is resistant to the first reflective layer 161 and the mask layer but not to the second reflective layer 162, or the etching process may be controlled by stopping when the second reflective layer 162 in the second region S2 is removed, regardless of the characteristics of the first reflective layer 161. After etching, the mask layer is removed to form the configuration of FIG. 14.

[0155] As a third method, after forming the first reflective layer 161 and the second reflective layer 162, a laser beam may be irradiated in a pattern to remove the second reflective layer 162 only in the second region S2. However, this method is effective only when the second reflective layer 162 is made of a material that melts, evaporates, or sublimes when irradiated with a laser beam, and is not suitable for optically transparent dielectrics that transmit laser beams. For this reason, a transfer foil 11 in which a dielectric and metal reflective layer is formed in the first region S1 and a dielectric reflective layer is formed in the second region S2, for example, by using titanium dioxide for the first reflective layer 161 and aluminum for the second reflective layer 162, is suitable, in which a partial metallic reflection is visible when observed.

[0156] 15, there are two methods for locally forming or locally removing the first reflective layer 161. In the first method, after the first reflective layer 161 is provided on the surface of the relief forming layer 14, a mask layer that is resistant to an etching solution is provided in the first region S1, the first reflective layer 161 in the second region S2 is removed, and after the mask layer is further removed, the second reflective layer 162 is provided.

[0157] As a second method, after providing the first reflective layer 161 on the surface of the relief forming layer 14, only the second region S2 may be irradiated with a laser beam to remove the first reflective layer 161, and then the second reflective layer 162 may be provided. This method is effective when the first reflective layer 161 is made of a material that reacts to a laser beam. For this reason, it is suitable for a configuration in which the first reflective layer 161 is made of a metal material such as aluminum or silver, and the second reflective layer 162 is made of a light-transmitting dielectric material.

[0158] When it is desired to remove the first reflective layer 161 with higher precision and accuracy than the above two methods, the method using the relief structure 15 described in the configuration of FIG. 14 is effective. When it is desired to use transparent reflective layers for both the first reflective layer 161 and the second reflective layer 162, a relief structure 15 extending in a direction parallel to the film transport direction when the reflective layers 161 and 162 are formed by vapor deposition is formed in the second region S2, and a relief structure 15 extending in a direction perpendicular to the transport direction is formed in the first region S1. Silicon oxide is formed as the first reflective layer 161, and then etched to remove the reflective layer in the second region S2. The configuration of FIG. 15 can be realized by subsequently forming the second reflective layer 162.

[0159] If a metal material is desired in the reflective layer, the first reflective layer can be made of aluminum and the second reflective layer of silicon oxide, as described in Japanese Patent Application No. 2017-521701. After removing the first and second reflective layers in the second region S2, a light-transmitting dielectric material can be further vapor-deposited to form a third reflective layer. This results in a first region S1 with a three-layer reflective layer consisting of one metal layer and two dielectric layers, and a second region S2 with a single dielectric layer (not shown). In this case, a higher refractive index of the third reflective layer enhances the optical effect in the second region S2, thereby improving the visibility of the displayed image 12. Furthermore, by controlling the difference in refractive index between the second and third reflective layers, the optical effect (e.g., color value and brightness) in the first region S1 can be changed.

[0160] (Fourth embodiment) Hereinafter, a fourth embodiment of the present invention will be described with reference to Figs. 22 to 24. Fig. 22 is a plan view schematically illustrating the configuration of a laminate (medium) 101 according to the fourth embodiment of the present invention. Fig. 23 is a cross-sectional view of the laminate 101 taken along line AA in Fig. 22. Fig. 24 is a cross-sectional view schematically illustrating a state in which the security patch 102 has been separated from the protective sheet 105 in the cross section of the laminate 101 illustrated in Fig. 23. The transfer foil 11 described above may be the security patch 102.

[0161] 22 and 23, the laminate 101 of the fourth embodiment is configured to include a protective sheet 105, an information recording sheet 106, a security patch 102, a star-shaped surface relief 104, and a laser engraving 113. As illustrated in FIG. 23, the protective sheet 105 and the information recording sheet 106 are adhered to each other at their respective boundaries. Therefore, the security patch 102 in the laminate 101 is configured to be sandwiched between the protective sheet 105 and the information recording sheet 106. In other words, the security patch 102 is enclosed within the protective sheet 105 and the information recording sheet 106 so as not to be exposed to the atmosphere outside the laminate 101. The laser engraving layer 19 described above may be the information recording sheet 106.

[0162] The protective sheet 105 is transparent in the visible light wavelength range, allowing the security patch 102 and the surface relief 104 to be directly observed from the protective sheet 105 side. The protective sheet 105 is provided to protect the enclosed security patch 102 and information recording sheet 106. The protective sheet 105 can be configured as a thermoplastic plastic layer. The thermoplastic plastic is preferably configured using a polyvinyl chloride material, an amorphous copolyester material, or a polycarbonate material as a base material.

[0163] The thickness of protective sheet 105 is preferably 50 μm or more and 800 μm or less. If protective sheet 105 is thinner than 50 μm, the physical strength is insufficient and handling becomes difficult. On the other hand, if protective sheet 105 is thicker than 800 μm, the effects of thickness variation and deflection become greater when processing protective sheet 105, making processing difficult.

[0164] The information recording sheet 106 is made of a material that changes when it absorbs the wavelength of a laser used to record information. The change can be foaming, carbonization, discoloration, or a combination of these phenomena. Information can be recorded on the information recording sheet 106 by changing the material's properties when irradiated with a laser whose intensity and irradiation spot size are adjusted to a predetermined value. The laser used to record information can be a solid-state laser. The laser can be a pulsed laser. The laser wavelength can be a single wavelength or multiple wavelengths. The information recorded on the information recording sheet 106 can be, for example, identification information. The information recording sheet 106 can be made of polycarbonate to which an energy absorber that absorbs the information-recording laser has been added. Such an information recording sheet 106 changes due to a chemical reaction in the polycarbonate caused by the heat generated by absorbing the laser. An example of the information recording sheet 106 is SD8B94, a product of SABIC's LEXAN series (registered trademark). The material used for the information recording sheet 106 may be polyvinyl chloride or amorphous copolyester in addition to the polycarbonate material.

[0165] The information recording sheet 106 preferably has a thickness of 50 μm or more and 800 μm or less. If the information recording sheet 106 is thinner than 50 μm, the insufficient thickness results in insufficient color development, resulting in poor contrast between the altered zone and the unaltered area. On the other hand, if the information recording sheet 106 is thicker than 800 μm, transparency is lost, resulting in a strong black appearance and poor contrast between the altered and unaltered areas.

[0166] As illustrated in FIG. 23 , the security patch 102 is configured by sequentially stacking an adhesive layer 109, a fracture layer 108, and a certification layer 107 in the direction from the protective sheet 105 to the information recording sheet 106, i.e., along the thickness direction of the laminate 101, and has a relief structure 103 between the fracture layer 108 and the certification layer 107. The relief structure 103 is referred to as the relief structure layer 103 in Japanese Patent Application No. 2020-132592. Therefore, the relief structure 103 can be referred to as the relief structure layer 103. In the security patch 102, the fracture layer 108 and the adhesive layer 109 are formed in contact with the protective sheet 105. The certification layer 107 is formed in contact with the information recording sheet 106. The relief structure 103 is composed of a surface relief 104 and a reflective layer 110. As illustrated in FIG. 23 , the relief structure 103 is formed at the boundary between the fracture layer 108 and the certification layer 107. According to the fourth embodiment, the protective sheet 105 is adhered to the adhesive layer 109 of the security patch 102 in the thickness direction of the laminate 101. The information recording sheet 106 is adhered to the certification layer 107 formed on the opposite side of the adhesive layer 109 of the security patch 102 in the thickness direction of the laminate 101. In other words, the laminate 101 has a structure in which the protective sheet 105, the adhesive layer 109 of the security patch 102, the fracture layer 108, the relief structure 103, the certification layer 107, and the information recording sheet 106 are formed in this order in the thickness direction. The certification layer 107 may be the laminate of the relief-forming layer 14 and the patch base 13 described above. The information recording sheet described above may also be the information recording sheet 107.

[0167] As illustrated in FIG. 23 , the relief structure 103 is composed of a surface relief 104 and a reflective layer 110. The surface relief 104 is composed of multiple fine concave-convex shapes with a height difference of 0.1 μm to 10 μm in the thickness direction of the laminate 101, spaced apart from each other at intervals of 0.1 μm to 20 μm in the width direction (direction perpendicular to the thickness direction) of the laminate 101. The surface relief 104 is formed using one or a combination of multiple optical structures, such as an optical diffraction structure, a non-reflective structure, an isotropic or anisotropic scattering structure, a lens structure, and a polarization-selective reflection structure. By having the above-described structure, the surface relief 104 can detect forgery or tampering of information recorded on the information recording sheet 106 by visual inspection or by a detection device. By having the above-described structure, the surface relief 104 provides decorativeness to the laminate 101. The surface relief 104 can form motifs and motif images according to the arrangement of the above-described structures. The observer can observe the form in which the motif is displayed. That is, the motif is visualized by the observer. Information such as authentication information may be recorded in the motif. Examples of motifs include portraits, landmark motifs, art, natural motifs, calligraphy, text, marks, symbols, signals, signs, codes, and geometric patterns. Codes can be barcodes and two-dimensional codes. An example of a geometric pattern is a colored pattern. An example of text is microtext. Examples of calligraphy are Western calligraphy, Islamic calligraphy, Georgian calligraphy, Chinese calligraphy, Japanese calligraphy, Korean calligraphy, Filipino Suyat, Thai calligraphy, Indian Oriya, and Nepalese calligraphy.

[0168] The relief structure 103 can be provided with a reflective layer 110, which allows the motif of the surface relief 104 to be easily observed. The reflective layer 110 improves the visibility of the relief structure 103. The reflective layer 110 allows complex visual effects to be realized by utilizing the optical properties of the relief structure 103. The reflective layer 110 can be made using a material that is easy to handle and inexpensive, and can be used to produce a high-gloss, opaque film. The reflective layer 110 can be formed from aluminum or compounds such as zinc sulfide or titanium dioxide, which have a high refractive index in visible light and are easy to process. The reflective layer 110 can be formed by a deposition method. The deposition method can be either a physical deposition method, a chemical deposition method, or both. The physical deposition method can be a vacuum evaporation method or a sputtering method. The reflective layer 110 is preferably formed to a thickness of 10 nm or more and 200 nm or less.

[0169] The reflective layer 110 can be made of a metal or a compound. The compound can be a metal compound or silicon oxide. When the reflective layer 110 is made of a metal, it has opacity. When the reflective layer 110 is made of a compound, it can be formed as a light-transmitting reflective layer. The reflective layer 110 can be formed as a single layer or a multilayer. When the reflective layer 110 is formed as a multilayer, it can be formed by stacking multiple metal layers and compound dielectric layers. When the reflective layer 110 is formed as a multilayer, a metal layer can be formed to partially cover the surface relief 104, while a compound dielectric layer can be formed to completely cover the surface relief 104. When the reflective layer 110 is formed as a multilayer, a metal layer can be formed to partially cover the surface relief 104, and a compound dielectric layer can be formed to partially cover the surface relief 104. In other words, when the reflective layer 110 is formed as a multilayer, the metal layer and the compound dielectric layer can be formed to completely cover the surface relief 104, or can be formed to partially cover the surface relief 104. When the reflective layer 110 is formed such that either the metal layer or the compound dielectric layer, or both, partially cover the surface relief 104, a difference in peel strength occurs between the portion where the metal layer and the compound dielectric layer are formed and the portion where the metal layer and the compound dielectric layer are not formed. Therefore, when the laminate 101 is destroyed by fraudulent means, the manner of fracture in the fracture layer 108 becomes more complex, making it more difficult to improperly remove the security patch 102 and reattach it to another item. The outline of the partially formed metal layer and / or compound dielectric layer in the reflective layer 110 can form a motif. Information may be recorded in the motif. The information recorded in the motif may be either authentication information or identification information, or a combination thereof.

[0170] The information on the reflective layer 110 can be recorded by a laser beam. The laser used for the laser beam can be a solid-state laser. The solid-state laser can be a semiconductor laser. The laser can be a pulsed laser. The laser wavelength can be single wavelength or multiple wavelengths. Recording information on the reflective layer 110 can be performed using the same process as recording information on the information recording sheet 106. The identification information recorded as the outline of the metal layer and / or compound dielectric layer may include part or all of the identification information recorded by the alteration of the information recording sheet 106. Furthermore, the identification information recorded as the outline of the metal layer and / or compound dielectric layer may be information obtained by encrypting part or all of the identification information recorded by the alteration of the information recording sheet 106. By recording information on the information recording sheet 106 as the outline of the metal layer and / or compound dielectric layer with a laser beam, tampering with the information recording sheet 106 or tampering due to medium replacement can be detected. The fracture shape of the fracture layer 108 leaves a trace of the outline of the metal layer and / or compound dielectric layer, allowing tampering to be detected.

[0171] The above-mentioned information is, for example, text, marks, symbols, signals, signs, codes, geometric patterns, and calligraphy. Examples of symbols are flags, shields, swords, spears, crowns, stars, moons, flowers, leaves, plants, birds, wings, fish, arthropods, mammals, reptiles, amphibians, legendary creatures, mythical gods, and mythical goddesses. Codes are, for example, barcodes and two-dimensional codes. Examples of geometric patterns are monk motifs. Text can be microtext. Examples of calligraphy are Western calligraphy, Islamic calligraphy, Georgian calligraphy, Chinese calligraphy, Japanese calligraphy, Korean calligraphy, Filipino Suyat, Thai calligraphy, Indian Oriya, and Nepalese calligraphy.

[0172] The mixed-type reflective layer 110 formed by laminating a metal layer and a compound dielectric layer can be formed by the following three methods. The first method involves forming a soluble resin only in the desired area, then forming a metal layer, a dielectric layer, or both, and then removing the soluble resin, metal layer, and dielectric layer by washing. The soluble resin can be applied partially by printing, which allows for the partial formation of a dielectric layer. The second method involves applying an acid- or alkali-resistant resin partially on the metal layer, and then etching the metal layer with acid or alkali. The acid- or alkali-resistant resin can be applied partially by printing. This method is highly productive and produces a sharp contour shape for the partially formed metal layer. The third method involves applying a resin material that is soluble or insoluble upon exposure, exposing it through a mask with the desired pattern, and then removing the unnecessary portions by washing or etching. This method allows for the partially formed metal layer to have a high-resolution contour shape. The above-mentioned methods are examples of methods for forming a mixed-type reflective layer 110 in which a metal layer and a compound dielectric layer are stacked, and the embodiments of the present invention are not limited to these. Various known techniques can be used as appropriate as long as they can form a mixed-type reflective layer 110 in which a metal layer and a compound dielectric layer are stacked.

[0173] 23, the certification layer 107 contacts the fracture layer 108 in the thickness direction of the laminate 101, either directly or via the reflective layer 110, and contacts the information recording sheet 106. In the fourth embodiment, the certification layer 107 of the security patch 102 is preferably bonded to the information recording sheet 106 and the protective sheet 105 with high adhesive strength. The adhesive strength between the security patch 102 and the information recording sheet 106 and the adhesive strength between the security patch 102 and the protective sheet 105 are preferably greater than 50 N / 25 mm.

[0174] In the fourth embodiment, if the adhesion strength between the security patch 102 and the information recording sheet 106 is greater than 50 N / 25 mm width, peeling between the security patch 102 and the information recording sheet 106 is easily prevented when the relief structure 103 is removed by fraudulent means, and the possibility of tampering with the relief structure 103 and reusing it is easily reduced.

[0175] In the fourth embodiment, in the security patch 102, the rupture layer 108 in contact with the protective sheet 105 and the certification layer 107 in contact with the information recording sheet 106 form the surface relief 104, which can protect the surface relief 104. In the fourth embodiment, the certification layer 107, the rupture layer 108, and the adhesive layer 109 are provided to adjust the adhesive strength between the security patch 102 and the protective sheet 105 and the information recording sheet 106.

[0176] Materials that can be used to form these structures include polyester, polyurethane, polyacrylate, acid-modified polyolefin, ethylene-vinyl acetate copolymer resin, polymethyl methacrylate, cyclic polyolefin, melamine, inorganic particles, epoxy resin, and cellulose resin. UV-curable resins, whose precursors are monomers, oligomers, or polymers containing ethylenically unsaturated bonds or groups, can also be used to form these structures. Examples of monomers include 1,6-hexanediol, neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate. Examples of oligomers include epoxy acrylate, urethane acrylate, and polyester acrylate.

[0177] In the fourth embodiment, the rupture layer 108 has a breaking strength of 15 N / 25 mm or more and less than 45 N / 25 mm in a 90-degree peel adhesion strength test, and it is preferable that the adhesive strength between the security patch 102 and the information recording sheet 106 and the adhesive strength between the security patch 102 and the protective sheet 105 are at least 5 N / 25 mm greater than the breaking strength of the rupture layer 108. As a result, if an attempt is made to remove the security patch 102 fraudulently, a break will occur in the rupture layer 108 or near the surface relief 104, preventing fraudulent use of the security patch 102. The adhesion between the reflective layer 110 formed on the surface relief 104 and the resin of the fracture layer 108 is low, and the unevenness of the surface relief 104 and the variations in the surface condition of the reflective layer 110 tend to make the adhesion uneven. Therefore, stress is likely to concentrate near the surface relief 104 at the time of fracture, and fracture can occur near the surface relief 104 as well as in the fracture layer 108. Note that the fractured portion in this case does not have to be in the fracture layer 108, and may be in the proof layer 107 as long as it is near the surface relief 104. It is also preferable that the fractured portion include both the fractured portion in the fracture layer 108 and the fractured portion in the proof layer 107. This ensures that the surface relief 104 is destroyed. If the breaking strength of the rupture layer 108 is 45 N / 25 mm or more, and the adhesive strength between the security patch 102 and the information recording sheet 106 and the adhesive strength between the security patch 102 and the protective sheet 105 are 5 N / 25 mm or more greater than the breaking strength of the rupture layer 108, the rupture will not occur near the surface relief 104, but will likely occur in the adhesive layer 109 and the certification layer 107. If the rupture occurs in the adhesive layer 109, the remaining adhesive layer 109 may be used to replicate the shape of the surface relief 104. If the rupture occurs in the certification layer 107, the certification layer 107 may be fraudulently removed along with the protective sheet 105 and may be used together with the protective sheet 105 to create a card or the like with a tampered certification layer 107. On the other hand, if the breaking strength of the rupture layer 108 is less than 15 N / 25 mm, the process of forming the security patch 102 on the surface of the protective sheet 105 by transfer, described below, will not be carried out properly, and transfer failures will likely occur.In the fourth embodiment, it is preferable that the adhesive strength of the security patch 102 and the information recording sheet 106 and the adhesive strength of the security patch 102 protective sheet 105 are at least 5 N / 25 mm greater than the breaking strength of the rupture layer 108, and are not more than 5 times the breaking strength of the rupture layer 108 by 5 N / 25 mm.

[0178] In the fourth embodiment, the rupture layer 108 is formed from a transparent resin and a filler having an average particle size of 1 μm or less. If the average particle size of the filler in the rupture layer 108 is greater than 1 μm, the filler may scatter light irradiating the laminate 101, potentially hindering the reading of information stored in the relief structure 103. The average particle size of the filler may be 10 nm or more. If the average particle size of the filler is 10 nm or more, defects due to filler aggregation are less likely to occur.

[0179] As will be described later, the filler in the rupture layer 108 is provided to prevent the certification layer 107 from being removed and reused if the laminate 101 is destroyed by fraudulent means. Furthermore, by including a filler in the rupture layer 108, the rupture strength of the rupture layer 108 can be controlled. The filler content in the rupture layer 108 may be in the range of 10% or more and 50% or less. If the filler content in the rupture layer 108 is in this range, the rupture strength can be easily controlled.

[0180] In a fourth embodiment, the filler material may be silica filler. When forming the security patch 102 using a resin containing silica filler, the silica filler may be unevenly distributed within the fracture layer 108 during the coating process. As shown in the scanning electron microscope (SEM) photograph in FIG. 28A , uneven distribution of the silica filler within the fracture layer 108 causes irregular cohesive failure in the fracture layer 108, resulting in an irregular fracture surface in the fracture layer 108, when the authentication layer 107 is removed by unauthorized means. More specifically, in the state shown in the SEM photograph in FIG. 28A , the adhesive layer 109 is formed such that a portion (adhesive layer 1 in FIG. 28A ) contains a large amount of silica filler, while the other portion (adhesive layer 2 in FIG. 28A ) contains little or no silica filler. This configuration prevents the information stored in the relief structure 103 from being read due to the irregular fracture surface formed when the fracture layer 108 is broken. Furthermore, the authentication layer 107 cannot be reused illegally. On the other hand, as shown in the SEM photograph of FIG. 28B, when the adhesive layer 109 does not contain silica filler, the irregular fracture surface formed in the fracture layer 108 cannot be observed. The shape of the silica filler may be regular, which is a fixed shape, or irregular. The shape of the regular filler can be spherical, acicular, or flat.

[0181] In the security patch 102, the adhesive layer 109 in contact with the protective sheet 105 and the certification layer 107 in contact with the information recording sheet 106 may each use a filler different from the filler used in the rupture layer 108. By incorporating a filler into each component of the security patch 102, peeling of areas other than the desired area and the generation of burrs can be prevented in the process of forming the security patch 102 on the surface of the protective sheet 105 by transfer, as described below. Furthermore, the material and shape of the filler contained in the adhesive layer 109 and the certification layer 107 may be different from the material and shape of the filler contained in the rupture layer 108. By creating a difference between the properties of the filler contained in the adhesive layer 109 and the certification layer 107 and the properties of the filler contained in the rupture layer 108, rupture can be more reliably generated in the rupture layer 108.

[0182] In the fourth embodiment, silica filler was described as an example of the filler contained in the rupture layer 108, but the filler contained in the rupture layer 108 is not limited to this. The filler may be formed of either an organic filler or an inorganic filler, or a mixture of these. The filler may be formed as a mixture of particles with different average particle sizes or may contain particles of different shapes. The filler may be formed of an organic material such as polyethylene powder and acrylonitrile-based fine particles. The filler contained in the adhesive layer 109 and the illumination layer 107, like the filler contained in the rupture layer 108, may be either an organic filler or an inorganic filler, or a mixture of these.

[0183] In the security patch 102, the adhesive layer 109, the breaking layer 108, and the authentication layer 107 do not necessarily have to be single layers, but may be multi-layered with an intermediate layer or the like provided therebetween.

[0184] 24 is a cross-sectional view that schematically illustrates a state in which the security patch 102 has been separated from the protective sheet 105 in the cross section illustrated in FIG. 23. As illustrated in FIG. 24, if an attempt is made to destroy the laminate 101 of the fourth embodiment and remove the certification layer 107 contained in the security patch 102 by fraudulent means, cohesive failure occurs near the fracture layer 108, which has a low fracture strength (a strength of 15 N / 25 mm or more and less than 45 N / 25 mm), and the surface relief 104. At this time, the fractured portion of the fracture layer 108, the certification layer 107, and the relief structure 103 contained within the fractured portion of the fracture layer 108 and the certification layer 107 remain integrally attached to the information recording sheet 106. In the fourth embodiment, the security patch 102 is significantly thinner than the information recording sheet 106, and therefore it is difficult to separate the security patch 102 from the information recording sheet 106, which has a thickness of 50 μm to 800 μm, without destroying the relief structure 103 of the security patch 102. Therefore, as illustrated in FIG. 24 , even if the laminate 101 is destroyed by fraudulent means, it is possible to prevent the certification layer 107, on which information is recorded, from being separated from the security patch 102 and the information recording sheet 106 and reused.

[0185] Conventionally, when fraudulently tampering with personal information on a card with a relief structure storing personal information, the method used is to completely separate and remove the authentication layer 107 from the personal information display area of ​​the genuine card and then reattach it over the altered personal information. One possible solution to prevent this method is to create a structure in which the laser-colorable material on which the personal information is written and the relief structure are firmly bonded together, making them inseparable. Generally, when the authentication layer 107 is removed from the card by fraudulent means, the security patch containing the relief structure peels off at an interface with weak adhesive strength or breaks at a location with weak breaking strength.

[0186] According to the laminate 101 of the fourth embodiment, the breaking strength of the rupture layer 108 is equal to or greater than 15 N / 25 mm and less than 45 N / 25 mm. Therefore, as described above, when the laminate 101 is broken, cohesive failure occurs in the vicinity of the rupture layer 108 or the surface relief 104. Furthermore, according to the laminate 101 of the fourth embodiment, the adhesive strength between the security patch 102 and the information recording sheet 106 and the adhesive strength between the security patch 102 and the protective sheet 105 are preferably 5 N / 25 mm or more greater than the breaking strength of the rupture layer 108, and are preferably no greater than five times the breaking strength of the rupture layer 108 (5 N / 25 mm). As a result, when an attempt is made to remove the security patch 102 from the laminate 101, the security patch 102 can be broken near the rupture layer 108 or the surface relief 104. Furthermore, the fracture layer 108 of the laminate 101 described as the fourth embodiment is formed from a transparent resin and a filler having an average particle size of 1 μm or less. Therefore, even if the fracture layer 108 is broken, it is difficult to extract the information stored in the relief structure 103 of the security patch 102 from the fracture surface. In other words, the laminate 101 of the fourth embodiment can eliminate the possibility of the adhesive structure being broken at the interface between the security patch and the protective sheet (protective material) and the adhesive structure being broken at the interface between the security patch and the information recording sheet (laser-colorable material), as in the conventional case.

[0187] (Fifth embodiment) Hereinafter, a card will be described in detail as a fifth embodiment of the present invention with reference to Figures 25 and 26. Figure 25 is a plan view for schematically explaining the configuration of card 111. Card 111 can be a data page of a passport or visa with a similar configuration. Figure 26 is a cross-sectional view of card 111 shown in Figure 25 taken along line BB.

[0188] As illustrated in FIG. 26 , the card 111 described in the fifth embodiment is configured with a card-shaped protective sheet 105, an information recording sheet 106, a white material layer 114, and a protective sheet 105, in this order, along the thickness direction of the card 111. Compared to the laminate 101 described in the fourth embodiment, the card 111 of the fifth embodiment further includes a white material layer 114 and a protective sheet 105, formed in this order, behind the information recording sheet 106, along the thickness direction of the card 111. Similarly to the laminate 101 described in the fourth embodiment, the security patch 102 is configured with a fracture layer 108, an adhesive layer 109, and a certification layer 107, laminated in this order from the protective sheet 105 to the information recording sheet 106, i.e., along the thickness direction of the card 111, and has a relief structure 103 between the adhesive layer 109 and the certification layer 107. Because the configuration of the security patch 102 is similar to that of the fourth embodiment, a detailed description thereof will be omitted.

[0189] In addition to the relief structure 103 of the security patch 102, the card 111 also has a printing layer 112 and a laser engraving 113 formed for recording information. As illustrated in FIG. 26 , the security patch 102 and the laser engraving 113 are formed at the boundary formed by bonding the protective sheet 105 and the information recording sheet 106. Meanwhile, the printing layer 112 is formed at the boundary formed by bonding the information recording sheet 106 and the white material layer 114. That is, in the card 111 of the fifth embodiment, the security patch 102 and the laser engraving 113 are configured to be enclosed by the protective sheet 105 and the information recording sheet 106. Meanwhile, the printing layer 112 is configured to be enclosed by the information recording sheet 106 and the white material layer 114. 25, in the card 111 of the fifth embodiment, the protection sheet 105 and the information recording sheet 106 are optically transparent to at least visible light so that the laser engraving 113 and the printing layer 112 can be visually or machine-recognized. The information recording sheet 106 may also be translucent.

[0190] In the card 111, the printed layer 112 is a layer that is provided in any desired color, either entirely or in a pattern such as letters or pictures, to convey the information to be conveyed. The printed layer 112 can be formed using ink. Printing on the printed layer 112 can affect the fracture state of the fracture layer 108. The ink used here can be offset ink, letterpress ink, gravure ink, or the like, depending on the printing method. Depending on the composition, the ink can be resin ink, oil-based ink, or water-based ink. Furthermore, depending on the drying method, the ink can be oxidative polymerization ink, penetration drying ink, evaporation drying ink, or ultraviolet curing ink. The printed layer 112 may use a functional ink that changes color depending on the illumination angle or observation angle of light. Such functional inks can be optically variable ink, color-shifting ink, or pearl ink. The printed layer 112 formed using each of the above functional inks can improve the anti-counterfeiting resistance of the card 111.

[0191] The print layer 112 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, and the toner is transferred to a print substrate using static electricity generated by the charge, and then heated and fixed to form the print layer 112.

[0192] The white material layer 114 is formed to impart white opacity to the card 111. The white opacity allows the printing layer 112 and the laser engraving 113 to be easily observed, while hiding information storage components such as an IC chip. The white material layer 114 is preferably made of a polyvinyl chloride material, amorphous copolyester material, or polycarbonate material containing a white material such as titanium oxide.

[0193] The thickness of the white material layer 114 is preferably 200 μm or more and 800 μm or less. If the thickness of the white material layer 114 is less than 200 μm, the white opacity will be insufficient, making it difficult to achieve the desired performance. On the other hand, if the thickness of the white material layer 114 is greater than 800 μm, the effects of thickness variations and deflection of the white material layer 114 during processing will become greater, making processing difficult, which is undesirable.

[0194] When the card 111 according to the present invention is destroyed by fraudulent means and the security patch 102 including the relief structure 103 is removed, cohesive failure occurs in the fracture layer 108, which has low fracture strength, and in the vicinity of the surface relief 104. As a result, the relief structure 103 remains attached to the information recording sheet 106. According to the card 111 of the fifth embodiment, the printing layer 112 on which information is recorded and the laser engraving 113 are also formed on the information recording sheet 106. Therefore, if the information recorded on the card 111 is altered and the card is used fraudulently, the security patch 102 and the information recording sheet 106 must be separated. However, as with the laminate 101 according to the fourth embodiment, it is extremely difficult to separate the security patch 102 from the thick information recording sheet 106 while maintaining the relief structure 103 within the thin security patch 102. However, since the protective sheet 105 separated from the security patch 102 contains no information or only incomplete information, there is no risk of the security patch 102 being misused.

[0195] (Sixth embodiment) 27A to 27C, a method for producing the laminate 101 according to the fourth embodiment and the card 111 according to the fifth embodiment will be described. Figures 27A to 27C are cross-sectional views that schematically illustrate a method for producing the laminate 101 according to the fourth embodiment of the present invention.

[0196] 27A shows a process in which security patch 102 is formed on the surface of protective sheet 105 by transfer. More specifically, when an appropriate external force (heat, pressure, etc.) 115 is applied from the carrier 116 to security patch 102 held by carrier 116, adhesive layer 109 of security patch 102 is adhered to protective sheet 105, and a portion of security patch 102 is separated from carrier 116 and transferred to the surface side of protective sheet 105. While FIG. 27A shows the process in which security patch 102 is transferred to the surface of protective sheet 105, in the sixth embodiment, security patch 102 may be transferred to the surface of information recording sheet 106.

[0197] In the process of transferring the security patch 102 to the surface of the protective sheet 105, a metal or resin stamper is used, the stamper surface temperature is about 80°C to 150°C, the stamper contact time is 0.1 seconds to 3 seconds, and the transfer pressure is 100 to 500 kg / cm. 2 It is preferable to perform the transfer under the above conditions. If the temperature is higher, the time is longer, or the pressure is excessive, the excessive heat may induce the transfer of unintended portions of the security patch 102. Furthermore, the excessive heat may cause unintended thermal deformation of the surface of the protective sheet 105, which is the transfer target. On the other hand, if the temperature is lower, the time is shorter, or the pressure is insufficient, the security patch 102 may not be properly adhered and transferred to the protective sheet 105. For this reason, it is necessary to select appropriate transfer conditions at the appropriate time in order to prevent partial or overall transfer defects during the transfer process. The security patch 102 according to each of the above-described embodiments of the present invention can be successfully transferred to the surface of the protective sheet 105 under the above-described transfer conditions.

[0198] The carrier 116 is configured to hold the security patch 102 before transfer. The carrier 116 is preferably a plastic film. More specifically, the carrier 116 may be a plastic film such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PP (polypropylene). However, the carrier 116 is preferably formed from a material that is less likely to deform or deteriorate due to external forces 115 such as heat and pressure applied when the security patch 102 is supported by the carrier 116. Depending on the application and purpose, the carrier 116 may be formed using paper, synthetic paper, plastic multilayer paper, resin-impregnated paper, or the like. According to the sixth embodiment, the thickness of the carrier 116 is preferably 4 μm or more. More preferably, the thickness of the carrier 116 is 12 μm or more and 50 μm or less. If the thickness of the carrier 116 is less than 4 μm, the physical strength is insufficient and handling is difficult.

[0199] 27A to 27C, the security patch 102 and the carrier 116 do not need to be in direct contact with each other, and an intermediate layer may be further provided between the carrier 116 and the security patch 102. In this case, it is possible to adjust the strength of the force required to peel the security patch 102 from the carrier 116 depending on conditions such as the thickness and material of the intermediate layer.

[0200] 27B shows a process of applying an appropriate external force 115 to adhere the structure in which the security patch 102 produced in the process shown in FIG. 27A is transferred to the protective sheet 105 to the information recording sheet 106. As illustrated in FIG. 27B, the protective sheet 105, the security patch 102, and the information recording sheet 106 are adhered together so that the security patch 102 is sandwiched between the protective sheet 105 and the information recording sheet 106.

[0201] In the process illustrated in FIG. 27B, in order to sufficiently bond the protective sheet 105, security patch 102, and information recording sheet 106, at least an amount of heat sufficient to soften and deform these components is required. In the bonding process illustrated in FIG. 27B, the amount of heat applied to bond the protective sheet 105, security patch 102, and information recording sheet 106 is significantly greater than the amount of heat applied in the transfer process illustrated in FIG. 27A. More specifically, when these components are made of a material containing polycarbonate, a time of approximately 1 to 30 minutes and a heat source temperature of 170°C to 200°C are required for the polycarbonate to soften and deform. The laminate 101 according to each embodiment of the present invention does not break under the conditions of the bonding process and functions well even after the bonding process.

[0202] In the sixth embodiment, FIG. 27B shows a configuration including only the security patch 102, the protective sheet 105, and the information recording sheet 106. On the other hand, when producing the card 111 according to the fifth embodiment of the present invention illustrated in FIGS. 25 and 26, a method is possible in which a white material layer 114 provided with a printing layer 112 is further laminated on the information recording sheet 106 side, and then external force 115 is applied to adhere the components. Furthermore, according to the sixth embodiment, when the security patch 102 is transferred to the information recording sheet 106, external force 115 can also be applied to the protective sheet 105 so as to sandwich the security patch 102 against the information recording sheet 106 to which the security patch 102 has been transferred. When the adhering process illustrated in FIG. 27B is completed, an integrated configuration is formed in which the security patch 102 is enclosed within the protective sheet 105 and the information recording sheet 106, as illustrated in FIG. 27C.

[0203] 27C, laser engraving 113 is formed by irradiating information recording sheet 106 with laser beam 117. In this manner, laminate 101 according to the fourth embodiment of the present invention can be formed. Although not shown, card 111 according to the fifth embodiment of the present invention can also be formed using the same method.

[0204] According to the sixth embodiment, the adhesive strength between the security patch 102, the protective sheet 105, and the information recording sheet 106 may be adjusted to be greater than 50 N / 25 mm. Therefore, when only the relief structure 103 is removed by unauthorized means, the security patch 102 having the relief structure 103 is difficult to reuse by tampering with the relief structure 103 by unauthorized means due to cohesive failure that occurs in the fracture layer 108 or near the surface relief 104.

[0205] (Seventh embodiment) Hereinafter, an information recording sheet for a card and a card using the same will be described as a seventh embodiment of the present invention with reference to FIGS. 29 is a cross-sectional schematic diagram of an information recording sheet 201 for a card of the present invention. A protective sheet 206 is laminated on an information recording sheet 207, and a security patch 205 is enclosed between the information recording sheet 207 and the protective sheet 206. The laser engraving layer 19 described above may be the information recording sheet 206. The relief structure layer 103 described later may be the relief forming layer 14. The protective sheet 206 described later may be the protective base layer 18. The information recording sheets 106 and 207 described later may be the information recording sheet 19.

[0206] The information recording sheet 207 is made of a material that changes its properties when it absorbs a laser beam with a specific wavelength for recording information. This change can occur directly due to the laser beam or indirectly due to the heat generated by absorbing the laser beam, and can result in phenomena such as foaming, carbonization, or discoloration of the material, or a combination of these. When the information recording sheet 207 is irradiated with laser beams whose intensity and irradiation spot size are adjusted to predetermined values, the material changes color and information can be recorded as a changed zone 208.

[0207] The laser used to record information can be a solid-state laser. The laser can be a pulsed laser or a continuous laser. The laser wavelength can be a single wavelength or multiple wavelengths. Examples include an Nd-YAG wavelength conversion ultraviolet laser (wavelength 380 nm), a fiber laser (wavelength 1064 nm), and a YAG laser (wavelength 1064 nm).

[0208] The information recorded on the information recording sheet 207 can be identification information. The laser recording material can be a polycarbonate material to which an energy absorber that absorbs the laser beam used to record information has been added. Such a material is altered by absorbing the laser beam and generating heat that causes a chemical change in the polycarbonate. A specific example of a laser recording material is SD8B94 from SABIC's LEXAN series (registered trademark).

[0209] The information recording sheet 207 is composed of a matrix phase made of polycarbonate, a heat-resistant base material, and a dispersed phase made of polyester resin, which softens more easily than polycarbonate. By adding an energy absorber that absorbs the laser used to record information to the polycarbonate, the polycarbonate itself undergoes a chemical change due to the heat generated by absorbing the laser, resulting in discoloration. The polyester resin can be an amorphous polyester resin with a glass transition temperature Tg of -20°C to 110°C, which ensures adhesion to the matrix phase. Furthermore, the use of an amorphous polyester resin also improves adhesion to the security patch.

[0210] The proportion of the dispersed phase made of the polyester resin is preferably 5 wt% or more and 30 wt% or less. If it is 5 wt% or less, no substantial effect can be obtained, and if it is 30 wt% or more, peeling occurs when stress such as bending occurs. Furthermore, the average particle size of the dispersed phase domains is preferably 0.1 μm or more and 10 μm or less.

[0211] When the polycarbonate resin in the matrix phase is altered by laser irradiation, its adhesiveness with the polyester resin in the dispersed phase decreases. As a result, if the laser engraving layer is peeled off for the purpose of tampering, the information recording sheet itself is destroyed, making tampering impossible. On the other hand, the area where the security patch 205 is located is not irradiated with laser, so the adhesiveness with the information recording sheet does not change, making peeling difficult.

[0212] The information recording sheet 207 preferably has a thickness of 50 μm or more and 800 μm or less. If it is thinner than 50 μm, the color of the laser engraving will not be developed sufficiently, resulting in poor contrast between the altered zone and the unaltered area. On the other hand, if it is thicker than 800 μm, transparency will be impaired, resulting in a strong black appearance and poor contrast between the altered zone and the unaltered area.

[0213] The protective sheet 206 only needs to be transparent in the visible light wavelength range so that the underlying security patch 205 and modified zone 208 can be seen with the naked eye. A transparent thermoplastic plastic such as a polycarbonate sheet can be used. The thickness of the protective sheet 206 is preferably 50 μm or more and 800 μm or less. If it is less than 50 μm, the physical strength will be insufficient, and if it is thicker than 800 μm, the effects of thickness variation and deflection will be significant when processing the protective sheet 206, making processing difficult.

[0214] The security patch 205 can be configured as a laminated body, for example, of a patch substrate 204, a relief-forming layer 203, and a rupture layer 202. The relief-forming layer 203, which is made of a diffraction grating or a hologram, is disposed on the patch substrate 204, and the rupture layer 202 is then laminated on top of it. A metal thin film or a high-refractive-index oxide thin film may be laminated on the relief-forming layer 203 to improve the visibility of the relief. The rupture layer 202 can be made of, for example, an adhesive, and can be formed as long as it has the ability to destroy the relief-forming layer 203 in the event of tampering, such as removing the security patch.

[0215] The relief forming layer 203 can be made of a thermoplastic resin, a thermosetting resin, or a photocurable resin. The synthetic resin forming the relief forming layer 203 can be the same as the synthetic resin forming the relief forming layer 14 according to the above-described embodiment. The relief forming layer 203 is not limited to a single layer, but may be multilayered. In the case of a multilayered structure, it can be a laminate of a curable resin and a thermoplastic resin. The thermoplastic resin can be a resin containing polymethyl methacrylate or acid-modified polyolefin. Alternatively, in the case of a multilayered structure, it can include layers of thermoplastic resins with different physical properties. Alternatively, the relief forming layer 203 can contain inorganic powder or polymer powder. The inclusion of powder can adjust the interfacial adhesion strength between the relief forming layer 203 and the patch substrate 204. Therefore, the side of the relief forming layer 203 on which the relief structure is formed can be a curable resin layer, and the opposite side can be a thermoplastic resin layer containing inorganic powder or polymer powder. The relief forming layer 203 can contain a resin with a higher melting point than the protective sheet.

[0216] The relief-forming layer 203 has concave or convex portions, or both concave and convex portions, and as a laminated optical structure, it has optical properties such as diffraction, light reflection suppression, isotropic or anisotropic light scattering, refraction, polarization- and wavelength-selective reflection, transmission, and light reflection suppression. For example, by providing a lacquer layer and providing a diffraction grating structure region in it with a pitch of 0.5 μm to 2 μm and a depth of 0.05 μm to 0.5 μm, the relief structure has the property of diffracting light. By providing a moth-eye structure or a deep grating structure in the relief-forming layer 203 with a pitch of 0.1 μm to 0.5 μm and a depth of 0.25 μm to 0.75 μm, the relief-forming layer 203 has the property of light reflection suppression, polarization- and wavelength-selective reflection, transmission, and light reflection suppression. The relief structure has the property of emitting isotropically or anisotropically scattered light by providing an area with a non-periodic linear or dot-like repeating structure at an average pitch of 0.5 μm to 3 μm and a depth of 0.05 μm to 0.5 μm in the relief-forming layer 203. The relief-forming layer 203 has a refractive index different from that of adjacent layers by providing an area with a structure at an average pitch of more than 3 μm and a depth of more than 0.5 μm in the relief-forming layer 203.

[0217] The optical properties of the relief-forming layer 203 can be perceived and detected by visual inspection or machine detection, thereby improving the anti-counterfeiting and anti-falsification properties and the design. The optical effect of the relief structure displays an image that can be seen by an observer. Examples of the image can be portraits, landmark motifs, natural motifs, calligraphy, geometric patterns, letters, numbers, signals, signs, symbols, emblems, coats of arms, or codes, or combinations thereof. Examples of the symbol can be any of the above-mentioned embodiments.

[0218] The material of the rupture layer 202 can include at least one material from a second group of materials consisting of polyurethane, polymethyl acrylate, polyester, acid-modified polyolefin, and ethylene-vinyl acetate copolymer resin.

[0219] The relief-forming layer 203 may also have a reflective layer between it and the fracture layer 202. The reflective layer may be made of a metal or a dielectric material; in the former case, it may be a concealing reflective layer, and in the latter case, it may be a light-transmitting reflective layer. Examples of metals include aluminum and silver. The dielectric may be a metal compound or silicon oxide. The metal compound may be a metal oxide, a metal sulfide, or a metal fluoride. Examples of metal compounds include zinc oxide, titanium oxide, niobium oxide (NbO2), and zinc sulfide. When the reflective layer is composed of two layers, a first reflective layer and a second reflective layer, two of the above materials are selected; for example, the first reflective layer may be silicon dioxide and the second reflective layer may be titanium dioxide.

[0220] When the refractive index of the dielectric for visible light is 2.0 or more, it is easy to obtain a difference in refractive index with the relief-forming layer 203, and the reflectance of reflected light generated according to the shape of the relief structure is improved, making it easier for the observer to view the image. The reflective layer can be formed by a deposition method. The deposition method can be either a physical deposition method or a chemical deposition method, or both. The physical deposition method can be a vacuum deposition method or a sputtering method. The reflective layer is preferably formed to a film thickness of 10 nm or more and 200 nm or less.

[0221] The material for the patch substrate 204 can be the same as that for forming the relief-forming layer 203. Among these, it can contain at least one of polymethyl methacrylate, polyester, cyclic polyolefin, melamine, and ethylene-vinyl acetate copolymer resin. These materials form an adhesive layer on the patch substrate, and tend to provide sufficient interfacial adhesion strength between the adhesive layer and the adjacent polycarbonate-containing layer. Furthermore, resins having a carbonate bond (-O-CO-O-), a urethane bond (-NH-CO-), or an ester bond (-O-CO-) can be used as the material for forming the adhesive layer. When adhering to polycarbonate, the interfacial adhesion strength tends to be high between polycarbonate and resins having ester bonds or urethane bonds, which have structures similar to carbonate bonds.

[0222] 30 is a cross-sectional view of an example of a card 212 using a card sheet according to the present invention. A white material layer 209 provided with a printed portion 211 and a back surface protective sheet 210 are laminated on a card sheet 201.

[0223] White material layer 209 is formed to impart white opacity to card 212. White opacity is a property that allows the printed portion 211 and laser engraving 208 to be easily observed, while hiding components that store information, such as an IC chip. White material layer 209 is preferably made of a material that contains an appropriate amount of a white material, such as titanium oxide, added to, for example, polyvinyl chloride material, amorphous copolyester material, or polycarbonate material.

[0224] The white material layer 209 preferably has a thickness of 200 μm or more and 800 μm or less. If the thickness of the white material layer 209 is less than 200 μm, the white opacity will be insufficient and it will be difficult to achieve the desired performance. On the other hand, if the thickness is more than 800 μm, the influence of thickness variation and deflection during processing will increase, which is undesirable.

[0225] The printed portion 211 can be any color. The printed portion 211 may be printed over the entire surface, or may include letters, pictures, geometric patterns, numbers, symbols, codes, etc., which are printed locally. Ink can be used as a material for forming the printed portion 211. Depending on the printing method, inks such as offset ink, letterpress ink, and gravure ink can be used. Depending on the composition, inks can be resin ink, oil-based ink, and water-based ink. Furthermore, depending on the drying method, inks can be oxidative polymerization ink, penetration drying ink, evaporation drying ink, and ultraviolet curing ink. The printed portion 211 may also use functional inks whose color changes depending on the illumination angle or observation angle of light. Examples of such functional inks include optical variable ink, color shift ink, and pearl ink. The functional ink may also be magnetic. The printed portion 211 formed using the above-mentioned functional inks can improve the anti-counterfeiting resistance of the card 212.

[0226] The back surface protective sheet 210 can be the same as the protective sheet 206 . 29 can be applied to the first to sixth embodiments described above. The information recording sheet 106 described above can be used instead of the information recording sheet 207, and the protective sheet 105 described above can be used instead of the protective sheet 206. In this case, the material constituting the information recording sheet 207 can be used for the information recording sheet 106. Furthermore, the information recording sheet 207 can be replaced with the information recording sheet 19, and the protective sheet 206 can be replaced with the protective sheet 18. In this case, the material constituting the information recording sheet 207 can be used for the information recording sheet 19.

[0227] (Manufacturing method) The security patch 205 is made from a transfer foil in which a patch substrate 204, a relief-forming layer 203, a reflective layer, and a fracture layer 202 are laminated in this order on a carrier film. As described above, the reflective layer can be formed by a deposition method. The deposition method can be either a physical deposition method, a chemical deposition method, or both. The physical deposition method can be a vacuum deposition method or a sputtering method. The other layers can be formed by applying a coating liquid and drying it in an oven.

[0228] In this embodiment, unevenness is formed in the relief forming layer 203. The unevenness can be obtained by applying a coating film containing a synthetic resin for forming the relief forming layer 203, and then transferring the uneven shape of a stamper (embossing plate) on which unevenness is formed to the coating film.

[0229] An embossing plate for transferring the recesses and projections to the relief-forming layer 203 can be obtained by the following method. First, a photosensitive resist is applied to one surface of a flat substrate, and then a beam is irradiated onto the photosensitive resist to expose a portion of the photosensitive resist. The photosensitive resist is then developed, thereby obtaining a master plate through photolithography. A metal stamper is then manufactured from the master plate by electroplating or other methods. This metal stamper is the embossing plate, and serves as a matrix for replicating the relief. Metal stampers can also be obtained by cutting a metal substrate using lathe technology, but when the relief has a complex shape or an extremely fine structure on the sub-wavelength order, cutting is difficult and so the stamper is produced by the aforementioned photolithography method.

[0230] When an appropriate external force (heat, pressure, etc.) is applied from the carrier side to the transfer foil on which the security patch is formed, the fracture layer is adhered to the protective sheet, and at the same time, the patch base 204 and the carrier are separated, and the security patch consisting of the layers below the patch base 204 is transferred to the protective sheet.

[0231] The carrier is a film provided to hold the security patch before transfer, and is preferably a plastic film. Specifically, it may be formed using a plastic film such as PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PP (polypropylene). The carrier preferably has a thickness of 4 μm or more. More preferably, the carrier has a thickness of 12 μm or more and 50 μm or less. If the carrier thickness is less than 4 μm, it is difficult to handle due to insufficient physical strength.

[0232] The transfer process uses a metal or resin stamper, with the stamper surface temperature at approximately 80°C to 150°C, the stamper contact time at 0.1 to 3 seconds, and the transfer pressure at 100 to 500 kg / cm. 2 The transfer can be performed under the following transfer conditions. By setting the temperature, contact time, and transfer pressure to below their respective upper limits, it is possible to prevent excessive heat from transferring the peripheral portion of the transfer foil to the transferee, and to prevent excessive heat from deforming the surface of the transferee. Furthermore, by setting the temperature, contact time, and transfer pressure to above their respective lower limits, it is possible to prevent part of the transfer foil from not being transferred to the transferee due to insufficient adhesion of the transfer foil to the transferee.

[0233] The information recording sheet 207, onto which the security patch 205 made of transfer foil has been transferred, has a supporting white material layer 209 having at least a printed portion 211 on the surface opposite the security patch 205. The top and bottom surfaces of this laminate are covered with a protective sheet 206 and a back protective sheet 210, and heat and pressure are applied to the entire structure, thereby bonding all layers together and embedding the security patch 205 between the information recording sheet 207 and the protective sheet 206. In this bonding process, the temperature of the heat source that heats them can be set to between 170°C and 200°C, and the time that the heat source is in contact with them can be set to between 1 minute and 30 minutes. This ensures reliable bonding of the information recording sheet 207 and the protective sheet 206, both of which contain polycarbonate.

[0234] Once the bonding process is complete, a card is formed in which all layers are integrated. A laser beam is irradiated onto the surface of this card, i.e., onto any location on the information recording sheet 207 via the protective sheet. This irradiation process allows a modified zone 208 to be formed on the information recording sheet 207. The area to be irradiated is determined by the information to be displayed in the modified zone 208, and may be, for example, letters and numbers indicating personal information such as a name, date of birth, or personal identification number, or an image such as a facial image or two-dimensional code. Through the above process, a card 212 is formed.

[0235] Furthermore, by applying the material constituting the information recording sheet 207 to the information recording sheet 106 described above, the same effects as those of the seventh embodiment can be obtained even in a structure including the information recording sheet 106. Furthermore, by applying the material constituting the information recording sheet 207 to the information recording sheet 19 described above, the same effects as those of the seventh embodiment can be obtained even in a structure including the information recording sheet 19. [Example]

[0236] The laminate 101 according to the fourth embodiment of the present invention and the card 111 according to the fifth embodiment of the present invention will be further described below with reference to examples and comparative examples. The present invention is not limited solely to the specific content of the examples described below. In the following description, unless otherwise specified, "parts" means parts by mass and "ratio" means mass ratio.

[0237] Example 1 The card 111 according to the fifth embodiment shown in FIGS. 25 and 26 was fabricated according to the steps illustrated in FIGS. 27A to 27C. (Laminate with carrier) A method for producing a laminate with a carrier will be described below. A 25 μm thick PET film was used as the carrier 116. One side of the carrier 116 was coated by gravure printing with ink A, which was prepared by dissolving the proof layer 107, which was in contact with the information recording sheet 106, in a solvent. The solvent contained in ink A was volatilized and removed so that the thickness of the proof layer 107 became 3 μm. Next, a metal cylindrical plate having a relief structure consisting of concave and convex shapes with a predetermined height and pitch was used to press the proof layer 107 at a pressure of 2 kgf / cm. 2 The roll forming process was carried out by pressing at a press temperature of 240°C and a press speed of 10 m / min.

[0238] Next, a reflective layer 110 was laminated by vacuum deposition on one side of the surface relief 104 molded on the proof layer 107. After that, ink B, in which the fracture layer 108 had been dissolved in a solvent, was coated by gravure printing. The solvent contained in ink B was volatilized and removed to a thickness of 4 μm. Next, ink C, in which the adhesive layer 109 had been dissolved in a solvent, was coated by gravure printing. By making the thickness after volatilizing and removing the solvent contained in the ink 109 to 1 μm, a security patch 102 with a carrier 116 was produced.

[0239] (Career 116) Lumirror 25T60 (manufactured by Toray Industries, Inc.) (Ink A in which the proof layer 107 in contact with the information recording sheet 106 is dissolved in a solvent) 20 parts acrylic resin 20 parts cellulose acetate 60 parts methyl ethyl ketone (Reflection layer 110) Sulfur sulfide (ZnS) thickness 600Å (Ink B in which the fracture layer 108 is dissolved in a solvent) Polyacrylic ester 20 parts 10 parts polyester Silica filler (average particle size 20 nm) 30 parts 50 parts methyl ethyl ketone 50 parts toluene (Ink C in which adhesive layer 109 is dissolved in a solvent) Polyacrylic ester 20 parts 10 parts polyester 50 parts methyl ethyl ketone 50 parts toluene

[0240] As illustrated in FIG. 27A, the security patch 102 with the carrier 116 thus prepared was transferred onto a protective sheet 105 (LEXAN SD8B14, 100 μm thick, melting point approximately 190° C. (manufactured by SABIC Corporation)) using a hot stamp transfer machine, and the carrier 116 was then removed. The transfer conditions were a transfer temperature of 140° C. and a pressure of 200 kg / cm. 2 , and the transfer time was 1 second.

[0241] Next, an information recording sheet 106 (LEXAN SD8B94, 100 μm thick, melting point approximately 190° C. (SABIC Corporation)) and a white material layer 114 (LEXAN SD8B24, 400 μm thick, melting point approximately 190° C. (SABIC Corporation)) with laser engraving 113 were bonded to the protection sheet 105 on which the security patch 102 had been transferred, so as to form the laminated structure illustrated in Fig. 26. The bonding conditions were heat at a temperature of 190° C. and pressure of 80 N / cm. 2 The pressure was applied for 15 minutes. This bonded the protective sheet 105, the information recording sheet 106, and the white material layer 114 together. Then, a card die was punched, and a laser engraving 113 was applied using a laser engraving machine (fiber laser type, emission wavelength 1064 nm) to produce a card 111.

[0242] Example 2 The security patch 102 and card 111 were produced using the same configuration and process as in Example 1, except that the ink in which the rupture layer 108 was dissolved in a solvent was changed to ink D below when producing the security patch 102. (Ink D in which the fracture layer 108 is dissolved in a solvent) Polyacrylic ester 20 parts 10 parts polyester Silica filler (average particle size 100 nm) 10 parts 50 parts methyl ethyl ketone 50 parts toluene

[0243] (Comparative Example 1) When producing security patch 102, the ink used to dissolve fracture layer 108 in a solvent was changed to ink E below, and the ink used to dissolve adhesive layer 109 in a solvent was changed to ink F below, except that security patch 102 and card 111 were produced using the same configuration and process as in Example 2. (Ink E in which the fracture layer 108 is dissolved in a solvent) Polyacrylic ester 20 parts 10 parts polyester Silica filler (average particle size 20 nm) 30 parts 50 parts methyl ethyl ketone 50 parts toluene (Ink F in which adhesive layer 109 is dissolved in a solvent) Melamine (melting point 345°C) 20 parts Cellulose acetate (melting point 200°C) 10 parts Polyester (melting point 70°C) 30 parts 80 parts methyl ethyl ketone

[0244] The cards 111 produced in the above-described Examples 1 and 2 and Comparative Example 1 were evaluated for the following items. For these cards, the 90° peel adhesive strength of the adhesive layer 109 and the protective sheet 105, the 90° peel adhesive strength of the security patch 102 and the information recording sheet 106, and the 90° peel adhesive strength of the adhesive layer 109 and the rupture layer 108 were measured. In addition, the difficulty of fraudulent reuse of the card 111 was evaluated by evaluating whether each interface could be separated without breaking. Furthermore, the presence or absence of changes in the visual effect due to the optical properties of the relief structure 103 in the card 111 was confirmed. The results are explained with reference to Table 1.

[0245] [Table 1]

[0246] As shown in Table 1, in Example 1, the adhesive strength between adhesive layer 109 and protective sheet 105 and the adhesive strength between security patch 102 and information recording sheet 106 were 5 N / 25 mm width greater than the breaking strength of rupture layer 108, making separation at the interface impossible. The breaking strength of rupture layer 108 was 17 N / 25 mm width, causing cohesive failure. From these results, in Example 1, it was difficult to separate security patch 102 from card 111, making unauthorized reuse difficult (shown as "o" in Table 1). Furthermore, no change in visual effect was observed with card 111 of Example 1 (shown as "o" in Table 1).

[0247] In the case of Example 2, the adhesive strength between adhesive layer 109 and protective sheet 105 and the adhesive strength between security patch 102 and information recording sheet 106 were 5 N / 25 mm width greater than the breaking strength of rupture layer 108, making separation at the interface impossible. The rupture layer 108 underwent cohesive failure at a breaking strength of 42 N / 25 mm width. From these results, it was determined that it was difficult to separate security patch 102 from card 111, making unauthorized reuse difficult (indicated by the symbol "o" in Table 1). Furthermore, no change in visual effect was observed with card 111 of Example 2 (indicated by the symbol "o" in Table 1).

[0248] In Comparative Example 1, the adhesive strength of adhesive layer 109 and protective sheet 105 was 5 N / 25 mm width greater than the breaking strength of rupture layer 108, making separation at the interface impossible. Meanwhile, the adhesive strength between security patch 102 and information recording sheet 106 was 4.6 N / 25 mm width, making separation at their interface possible. The breaking strength of rupture layer 108 was 42 N / 25 mm width, causing cohesive failure. Based on these results, it was determined that security patch 102 was easy to separate from card 111, making it susceptible to fraudulent reuse (indicated by the symbol "x" in Table 1). Furthermore, no visual changes were observed in card 111 of Comparative Example 1 (indicated by the symbol "o" in Table 1).

[0249] When evaluating the cards 111 of Examples 1 and 2 and Comparative Example 1 described above, a comprehensive evaluation was conducted based on two indicators: the difficulty of unauthorized reuse and the change in visual effect due to the optical properties of the relief structure. That is, for these cards 111, only if both of these indicators were met (indicated by the symbol "◯" in Table 1), was the card 111 evaluated as overall acceptable. On the other hand, if unauthorized reuse was possible or a change in visual effect was observed, the card 111 was evaluated as overall unacceptable. For this reason, each of the cards 111 of Examples 1 and 2 was evaluated as overall acceptable. On the other hand, the card 111 of Comparative Example 1 was evaluated as overall unacceptable.

[0250] The evaluation results of the card 111 of Examples 1 and 2 and Comparative Example 1 described above will be considered. With the laminate 101 according to the fourth embodiment of the present invention and the card 111 according to the fifth embodiment, if the adhesive strength between the security patch 102 and the protective sheet 105 and the adhesive strength between the security patch 102 and the information recording sheet 106 are greater than 50 N / 25 mm and the rupture strength of the rupture layer 108 is equal to or greater than 15 N / 25 mm and less than 45 N / 25 mm, cohesive failure occurs in the rupture layer 108, making it difficult to separate the security patch 102, including the relief structure 103 on which information is recorded, from the card 111. For this reason, the cards 111 of Examples 1 and 2 were difficult to reuse fraudulently.

[0251] On the other hand, in the card 111 of Comparative Example 1, the adhesive strength between the security patch 102 and the information recording sheet 106 was 4.6 N / 25 mm width, and it was possible for the security patch 102 and the information recording sheet 106 to separate at this boundary. Therefore, there was a possibility that the card 111 of Comparative Example 1 could be fraudulently reused. For this reason, the card 111 of Comparative Example 1 was deemed to have failed overall, as the possibility of fraudulent reuse could not be ruled out.

[0252] Next, the card sheet according to the seventh embodiment of the present invention will be further described with reference to Example 3 and Comparative Example 2. In the following description, unless otherwise specified, "wt parts" means parts by mass.

[0253] Example 3 As a protective sheet for the card sheet according to the present invention, a polycarbonate sheet LEXAN SD8B14 (manufactured by SABIC), 100 μm thick, was used.

[0254] The following information recording sheets were prepared.

[0255] The polycarbonate resin has a Tg of 140° C., and an example of such a polycarbonate resin is Iupilon (manufactured by Mitsubishi Gas Chemical Co., Inc.) The amount of such a polycarbonate resin was 80 parts by weight. The polyester resin is a highly heat-resistant amorphous polyester resin, such as Vylon GK-360 (manufactured by Toyobo Co., Ltd.) (number average molecular weight 16,000, glass transition temperature 56°C, amorphous). The amount of such polyester resin was 10 parts by weight. A composite oxide pigment (for example, Tomatec Color, manufactured by Tomatec Co., Ltd.) was used as the laser light absorbing additive, laser light absorbing pigment. The amount of such a composite oxide pigment was 1 part by weight. As the refractive index-modulating additive, an eposter-based additive (for example, manufactured by Nippon Shokubai Co., Ltd.) was used. The amount of such a refractive index-modulating additive was 1 part by weight. The above materials were dry-blended and then kneaded at a temperature of 180°C and a speed of 10 m / min to obtain a blended pellet resin, which was then extruded at 180°C to obtain a 100 μm thick sheet.

[0256] A polycarbonate sheet (thickness: 400 μm) containing 5 wt % of titanium oxide, which is a white pigment, was used as the white material layer.

[0257] The security patch used was a hologram transfer foil consisting of a patch substrate (Lumirror 50 μm, T60T PET film) and a fracture layer (Dianal BR grade).

[0258] After transferring the security patch from the transfer foil to the information recording sheet prepared above, the protection sheet, information recording sheet, white material layer, and protection sheet are layered on top of each other, and the sheet is then heated at 190°C and 2 kgf / cm 2 The laminate was then heated for 1 minute and 5 minutes to obtain a card.

[0259] Next, laser engraving was carried out from the protective sheet side of the card under the following conditions.

[0260] Nd-YAG wavelength conversion type ultraviolet laser (wavelength 380nm) Output: 0.05W Scan interval: 40 μm Fiber laser (wavelength 1064 nm) and YAG laser (wavelength 1064 nm) can also be used.

[0261] (Comparative Example 2) A card was produced in the same manner as in Example 3, except that the information recording sheet was made of the same material as in Example 3 and had a composition of 98% polycarbonate, 1% laser light absorbing additive, and 1% refractive index modulating additive.

[0262] When a cutter was used to remove the security patch from the laser-engraved card, the security patch was destroyed in Example 3 due to the high adhesion between the security patch and the information recording sheet, but could be peeled cleanly in Comparative Example 2 due to the low adhesion. Furthermore, when the protective sheet and the information recording sheet were peeled away, the information recording sheet in the modified zone was destroyed in Example 3, whereas the modified zone could be peeled away without being destroyed in Comparative Example 2.

[0263] The above describes each embodiment and several examples of the present invention, but the technical scope of the present invention is not limited to the above-mentioned embodiments, and various changes and deletions can be made to or from each component, or the embodiments can be combined with configurations of conventional technology, without departing from the spirit of the present invention. [Explanation of symbols]

[0264] 10, 101... Laminate 10S...Surface 11 Transfer foil 12···Images 121···First motif 122...Second motif 13. Patch base 14, 203···Relief cambium 15. Relief structure 15a...First relief structure 15b...Second relief structure 16, 110...Reflection layer 161...1st reflective layer 162...Second reflective layer 17, 109...adhesive layer 18. Protective sheet 19. Information Recording Sheet 20 cards 20a...Surface 20b...Back side 21...Support layer 22. Altered Zone 23 Printed form 24. Career 102 Security Patch 103···Relief structure layer 104···Surface relief 105, 206 Protective sheet 106, 207...Information recording sheet 107. Proof Layer 108, 202... Fracture layer 111···Card 112...printing layer 113 Laser Engraving 114, 209...white material layer 115...external force 116···Career 117...Laser beam 201···Card sheet 204 Patch base 205 Security Patch 208... Denatured Zone 210 Back protection sheet 211...Printing Department 212···Card R1...Island area R2...Sea area SR1: First relief area SR2: Second relief area S1...1st area S2...Second area T1,T2...Interfacial adhesion strength

Claims

1. a transfer foil configured by laminating at least a patch substrate, a relief-forming layer, a reflective layer, and an adhesive layer in this order along the thickness direction; a protective sheet provided on a first side in the thickness direction of the transfer foil; an information recording sheet provided on a second side of the transfer foil opposite the protective sheet in the thickness direction; Equipped with the relief-forming layer has a relief structure having an uneven shape with concave and convex portions formed on at least a part of a first surface that is in contact with the reflective layer, a second surface of the reflective layer in contact with the first surface is formed into a shape corresponding to the concave-convex shape of the relief structure; the relief-forming layer is formed from one or a combination of a thermoplastic resin, a thermosetting resin, and an ultraviolet-curing resin; When viewed from the thickness direction, the relief structure has a plurality of island regions and sea regions formed in a predetermined pattern on the first surface, the island regions of the relief-forming layer are provided with one or more combinations of functional groups including a hydroxyl group, a carboxyl group, and a carbonyl group, and a roughened surface; The sea region does not have the functional group or the rough surface, or the content of the functional group is smaller than that of the island region, or the degree and area of ​​the rough surface are smaller. Laminate.

2. The relief-forming layer is a first relief region having a first relief structure in which the recesses and the protrusions are formed to extend in a first direction along the thickness direction, and the recesses and the protrusions are formed alternately in a second direction perpendicular to the first direction; a second relief region having a second relief structure which is formed with directivity in a direction different from the first direction by at least 30 degrees or more when viewed from a direction perpendicular to a plane defined by the first direction and the second direction, or in which the recesses and protrusions are formed irregularly; Equipped with When viewed from the thickness direction, the first relief region is arranged to overlap the sea region, and the second relief region is arranged to overlap the island region. The laminate according to claim 1 .

3. a transfer foil configured by laminating at least a patch substrate, a relief-forming layer, a reflective layer, and an adhesive layer in this order along the thickness direction; a protective sheet provided on a first side in the thickness direction of the transfer foil; an information recording sheet provided on a second side of the transfer foil opposite the protective sheet in the thickness direction; Equipped with the relief-forming layer has a relief structure having an uneven shape with concave and convex portions formed on at least a part of a first surface that is in contact with the reflective layer, a second surface of the reflective layer in contact with the first surface is formed into a shape corresponding to the concave-convex shape of the relief structure; the relief structure is formed from one or a combination of a thermoplastic resin, a thermosetting resin, and an ultraviolet curing resin; When viewed from the thickness direction, the relief structure has a plurality of island regions and sea regions formed in a predetermined pattern on the first surface, a contact angle of the coating liquid of the adhesive layer with respect to the reflective layer in the island regions is smaller than the contact angle of the coating liquid of the adhesive layer with respect to the reflective layer in the sea regions; the adhesive layer has a breaking strength greater than the interfacial adhesive strength and breaking strength between the patch substrate and the relief-forming layer; The relief-forming layer is a first relief region having a first relief structure in which the recesses and the protrusions are formed to extend in a first direction along the thickness direction, and the recesses and the protrusions are formed alternately in a second direction perpendicular to the first direction; a second relief region having a second relief structure which is formed with directivity in a direction different from the first direction by at least 30 degrees or more when viewed from a direction perpendicular to a plane defined by the first direction and the second direction, or in which the recesses and protrusions are formed irregularly; Equipped with When viewed from the thickness direction, the first relief region is arranged to overlap the sea region, and the second relief region is arranged to overlap the island region. Laminate.

4. the area occupied by the island region is 50% or more and 80% or less of the total area of ​​the entire region including the island region and the sea region; The laminate according to any one of claims 1 to 3.

5. the island regions have similar shapes and are regularly arranged, and the center-to-center distance between adjacent island regions is 40 μm or more and 400 μm or less; The laminate according to any one of claims 1 to 4.

6. a transfer foil configured by laminating at least a patch substrate, a relief-forming layer, a first reflective layer, a second reflective layer, and an adhesive layer in this order along the thickness direction; a protective sheet provided on a first side in the thickness direction of the transfer foil; an information recording sheet provided on a second side of the transfer foil opposite to the first side in the thickness direction; Equipped with at least one of the first reflective layer and the second reflective layer is made of a light-transmitting material having a refractive index higher than that of the relief-forming layer and the adhesive layer; the relief-forming layer has a relief structure having an uneven shape with concave and convex portions formed on at least a part of a first surface that is in contact with the first reflective layer, a second surface of the first reflective layer in contact with the first surface is formed in a shape corresponding to the concave-convex shape of the relief structure; a surface shape corresponding to the first reflective layer and the second reflective layer is formed at an interface where the first reflective layer and the second reflective layer are in contact with each other; When viewed from the thickness direction, the transfer foil has a plurality of first regions and second regions formed in a predetermined pattern, the first reflective layer and the second reflective layer are provided in the first region; In the second region, only the first reflective layer is provided, an interfacial adhesive strength between the first reflective layer and the adhesive layer is different from an interfacial adhesive strength between the second reflective layer and the adhesive layer; one of the first region and the second region, in which the interfacial adhesive strength at the interface with the adhesive layer is relatively high, is an island region scattered in the other region, and the other region, in which the interfacial adhesive strength at the interface with the adhesive layer is relatively low, is a sea region surrounding the region in which the interfacial adhesive strength at the interface with the adhesive layer is relatively high; the interfacial adhesive strength at the interface of each layer of the transfer foil is smaller than the interfacial adhesive strength between the transfer foil and the protective sheet or the information recording sheet, an interfacial adhesion strength between the patch substrate and the relief-forming layer and a breaking strength of the relief-forming layer are smaller than an interfacial adhesion strength between the first reflective layer and the second reflective layer and an interfacial adhesion strength between the relief-forming layer and the first reflective layer; Laminate.

7. the first reflective layer or the second reflective layer and the adhesive layer both have hydrophilic or hydrophobic surface properties in the island regions, and have surface properties different from each other or similar to the surface properties of the island regions in the sea regions, and a contact angle of a coating liquid of the adhesive layer with the first reflective layer or the second reflective layer is smaller in the island regions; The laminate according to claim 6.

8. In the island region, the first reflective layer or the second reflective layer is bonded to the adhesive layer by at least one chemical interaction selected from an ionic bond, a covalent bond, and a hydrogen bond; In the sea region, the first reflective layer or the second reflective layer is bonded to the adhesive layer by physical interaction due to intermolecular forces. The laminate according to claim 6 or claim 7.

9. the area occupied by the island region is 50% or more and 80% or less of the total area of ​​the entire region including the island region and the sea region; The laminate according to any one of claims 6 to 8.

10. the island regions have similar shapes and are regularly arranged, and the center-to-center distance between adjacent island regions is 40 μm or more and 400 μm or less; The laminate according to any one of claims 6 to 9.

11. The laminate according to any one of claims 6 to 10, further comprising a support layer provided on a first side of the transfer foil. card.

Images