Laminate

Abstract

To provide a laminate which can achieve reduction in environmental loads and includes an IC module such as a credit card, a cash card and an ID card.SOLUTION: An IC card 1 which is a laminate housing an IC module 7 includes an antenna 8 connected to the IC module 7, a pair of core layers 4 and 5 sandwiching an antenna 8, and a pair of transparent over sheet layers 3 and 6 outside the pair of core layers 4 and 5. The core layers 4 and 5 and the over sheet layers 3 and 6 include a biomass resin layer. At least one of the pair of over sheet layers 3 and 6 is composed of a plurality of layers where the respective biomass resin layers are stacked on both surfaces of a resin layer different from the biomass resin layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a laminate including an IC module for, for example, a credit card, a cash card, an ID card, or the like. [Background technology]

[0002] Conventional IC cards include contact IC cards, which input and output electrical signals through an external connection terminal on the card surface, and contactless IC cards, which input and output electrical signals through an antenna via electromagnetic induction, etc. In addition to these, dual-interface IC cards, which combine the functions of both contact and contactless IC cards with a single IC chip, are also in use. Dual-interface IC cards, in particular, can be used as contact IC cards, which are effective in preventing external leakage of input and output data during financial transactions, and as highly convenient contactless IC cards, which allow data to be exchanged in close proximity when entering and exiting a room or using a ticket gate at a station. For this reason, dual-interface IC cards are becoming increasingly popular in the market.

[0003] The laminate includes an antenna-embedded layer that houses an antenna and a pair of core layers provided on both sides of the antenna-embedded layer, and an IC module is mounted in a recess formed by cutting one of the core layers and the antenna-embedded layer. A conductive plate that electrically connects the IC module and the antenna is placed in the recess of the laminate, and the conductive plate and the IC module are bonded with a conductive adhesive. The laminate thus obtained by mounting the IC module in the recess formed by cutting one of the core layers and the antenna-embedded layer can be a contact type, a non-contact type, or a combined contact / non-contact type laminate.

[0004] In recent years, there has been a demand for reducing fossil fuel consumption and waste plastics in order to reduce the environmental impact. In such cases, if plant-derived biomass resin materials could be used as materials for contact, non-contact, and combined contact / non-contact laminates, it would be advantageous because it would reduce the environmental impact toward carbon neutrality compared to using only petroleum-derived resin materials. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2008-310604 [Patent Document 2] Patent Publication No. 2015-110300 Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure has been made in consideration of these points, and aims to provide a laminate that can reduce the environmental load. [Means for solving the problem]

[0007] The first invention of this embodiment is a laminate having an IC module built in, comprising an antenna connected to the IC module, a pair of core layers sandwiching the antenna, and a pair of transparent over-sheet layers on the outside of the pair of core layers, wherein the core layer and the over-sheet layer comprise a biomass resin layer, and at least one of the pair of over-sheet layers is composed of multiple layers in which the biomass resin layer is laminated on both sides of a resin layer different from the biomass resin layer.

[0008] A second invention according to this embodiment is a laminate according to the first invention, wherein the multiple layers are laminated sheets formed by co-extrusion.

[0009] The third invention according to this embodiment is a laminate according to the first or second invention, further comprising an intermediate layer between either the pair of core layers or the pair of over-sheet layers, the intermediate layer including the multiple layers.

[0010] A fourth invention according to this embodiment is the laminate of any one of the first to third inventions, wherein the different resin layer is a polycarbonate resin layer.

[0011] The fifth invention according to this embodiment is a laminate of any one of the first to fourth inventions, in which the weight percentage of biomass-derived components in the entire laminate including the IC module and the antenna is 10% or more and 45% or less.

[0012] A sixth invention according to this embodiment is the laminate of any one of the first to fifth inventions, wherein the softening temperature of the biomass resin layer is 90°C or higher and 105°C or lower.

[0013] The seventh invention according to this embodiment is a laminate, in any one of the first to sixth inventions, in which a picture printed layer is provided on the surface of at least one of the pair of over-sheet layers facing away from the core layer, via a concealing layer.

[0014] An eighth invention according to this embodiment is a laminate according to any one of the first to seventh inventions, wherein at least one of the pair of over-sheet layers contains a laser beam color developing agent.

[0015] A ninth invention according to this embodiment is a card having the laminate of any one of the first to eighth inventions.

[0016] A tenth aspect of the present invention is a booklet having the laminate of any one of the first to eighth aspects of the present invention. [Effects of the Invention]

[0017] As described above, according to the present disclosure, it is possible to provide a laminate that can reduce the environmental load. [Brief explanation of the drawings]

[0018] [Figure 1] 1A and 1B are a plan view and a cross-sectional view illustrating the structure of a laminate according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view illustrating the structure of an oversheet of the laminate according to the first embodiment. [Figure 3] 1 is a structural formula illustrating a method for producing a biomass resin according to a first embodiment. [Figure 4] 1A and 1B are diagrams illustrating the structure of an IC module. [Figure 5] 3A to 3C are cross-sectional views illustrating a method for manufacturing a laminate according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view illustrating the structure of a laminate according to a second embodiment. [Figure 7] 10A and 10B are a schematic perspective view and a cross-sectional view illustrating the structure of a laminate according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] An example of the laminate of the present disclosure will be described below with reference to the drawings, etc. However, the laminate of the present disclosure is not limited to the embodiments and examples described below.

[0020] The figures shown below are schematic illustrations. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. Furthermore, hatching indicating the cross section of a member is omitted as appropriate in each figure. The numerical values ​​such as dimensions of each member and the names of materials described in this specification are examples of embodiments and are not limited to these, and may be selected and used as appropriate. In this specification, terms specifying shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are intended to include not only their strict meanings but also substantially the same states.

[0021] 1. First embodiment An example of a first embodiment of a laminate according to the present disclosure will be described. FIGS. 1 to 5 are diagrams showing an embodiment of a laminate according to the present disclosure. In this embodiment, a dual interface IC card (hereinafter also referred to as a laminate or an IC card) 1 incorporating an IC module 7 will be described as an example of a laminate. Note that the laminate also includes contactless IC cards and contact IC cards other than dual interface IC cards, and further includes cards in general that do not incorporate an IC module.

[0022] For ease of explanation, an XYZ coordinate system is set for the IC card 1. First, as shown in Figures 1(a) and 1(b), the Z axis is taken as the normal direction to the main surface of the IC card 1. Then, the direction from the main surface on which the external connection terminals 71 of the IC module 7 are not arranged to the main surface on which the external connection terminals 71 are arranged is defined as the +Z direction or upward in the thickness direction, and the opposite direction is defined as the -Z direction or downward in the thickness direction.

[0023] When IC card 1 is viewed from the +Z direction, the line perpendicular to both short sides of dual interface IC card 1 and the Z axis is defined as the X axis. The direction from one short side closer to external connection terminal 71 toward the other short side is defined as the +X direction or rightward, and the opposite direction is defined as the -X direction or leftward. The axis perpendicular to the X and Z axes is defined as the Y axis, and the direction from one long side farther from external connection terminal 71 toward the other long side is defined as the +Y direction or upward, and the opposite direction is defined as the -Y direction or downward.

[0024] Fig. 1(a) is a plan view of the IC card 1 as seen from the +Z direction, and Fig. 1(b) is a cross-sectional view of the IC card 1 of Fig. 1(a) cut along line AA parallel to the X axis as seen from the -Y direction. Fig. 2 is a cross-sectional view showing the details of the configuration of the over-sheet layers 3 and 6.

[0025] As shown in FIG. 1(a), IC card 1 has the form of a thin, generally rectangular plate with rounded corners in a plan view from the +Z direction. Furthermore, on the surface of the IC card on the +Z direction side, an IC module 7 including an external connection terminal 71 can be seen slightly to the upper left of the center, i.e., toward the -X direction and toward the +Y direction from the center. As shown in FIG. 1(b), IC module 7 is embedded in a recess 9 formed in card base 2, and is positioned so that the surface of external connection terminal 71 on the +Z direction side is generally flush with the surface of card base 2 on the +Z direction side. This form of dual interface IC card 1 complies with ISO / IEC 7816, the international IC card standard.

[0026] As shown in FIG. 1(b), the card base 2 constituting the card body of the dual interface IC card 1 is formed by laminating an over-sheet layer 6, a core layer 5, a core layer 4, and an over-sheet layer 3 in this order from the -Z direction side. Typically, the over-sheet layers 3 and 6 are made of a transparent base material, and the core layers 4 and 5 are made of a white base material, but this is not limited thereto. An antenna 8 is disposed between the core layers 4 and 5 so as to be sandwiched between them. A printed layer 110 is provided on the outer side of the over-sheet layer 3 of the IC card 1, i.e., on the surface facing the +Z direction, and a printed layer 120 is provided on the surface of the core layer 5 of the IC card 1 facing the over-sheet layer 6.

[0027] Rectangular metal conductive plates 100 are welded to both ends of the antenna wire that constitutes the antenna 8. The recess 9 is formed with three depth levels. Specifically, the first recess 9a, which is the shallowest, accommodates the substrate 72 of the IC module 7, with the lower surface of the substrate 72 abutting the upper surface of the first recess 9a. The second recess 9b, which is the deepest, forms a space to accommodate the IC chip body 74 of the IC module 7 that protrudes downward. The third recess 9c, which is located between the depths of the first recess 9a and the second recess 9b, exposes a pair of conductive plates 100 that are electrically connected to the antenna 8 toward the opening of the recess 9. The third recess 9c can be filled with a conductive adhesive layer 10 containing, for example, conductive particles, to electrically connect the electrical contacts of the IC module 7 and the conductive plates 100. As a result, the IC module 7 and the antenna 8 form a contactless communication circuit.

[0028] Thus, IC card 1, which is a laminate, has an IC module 7 built in, an antenna 8 connected to IC module 7, and a pair of core layers 4 and 5 that sandwich antenna 8 from both sides. Furthermore, IC card 1 has a pair of transparent over-sheet layers 3 and 6 on the outside of the pair of core layers 4 and 5. Here, core layers 4 and 5 and over-sheet layers 3 and 6 have biomass resin layers as described below. The biomass resin layers are bio-engineering plastics whose main raw material is plant-derived isosorbide.

[0029] Furthermore, at least one of the pair of over-sheet layers 3 and 6 is composed of multiple layers, with the biomass resin layer laminated on both sides of a different resin layer. For example, it can have a three-layer structure consisting of a biomass resin layer, a polycarbonate resin layer, and another biomass resin layer. This structure allows IC card 1 to have a higher plant-derived biomass resin content than cards primarily composed of typical card substrates such as polyvinyl chloride, PET-G, or polycarbonate, thereby reducing the environmental impact.

[0030] Furthermore, the process of laminating the core layers 4 and 5 and the over-sheet layers 3 and 6 and integrating them by heat fusion can be performed within the same temperature range as for ordinary card substrates, allowing existing manufacturing equipment to be used as is. Furthermore, in the over-sheet layers 3 and 6 of the IC card 1, which are located near the outermost surface, a different resin layer is sandwiched between the biomass resin layers. This allows the physical properties and appearance quality of the card to be adjusted as needed, resulting in a high-quality IC card. Because the card has the same physical properties and strength as ordinary cards, it can be used as a card that fully satisfies the standards required for IC cards, such as ISO / IEC 7810 and ISO / IEC 7816.

[0031] The configuration of the IC card 1 of this embodiment and the manufacturing method thereof will be described in detail below.

[0032] (a) Card base The card base 2 refers to the card body, excluding the IC module 7, that constitutes the IC card 1, which is a dual-interface IC card. As described above, the card base 2 typically has a configuration in which an over-sheet layer 6, a core layer 5, a core layer 4, and an over-sheet layer 3 are laminated in this order from one end in the -Z direction in the thickness direction. Between the core layers 4 and 5, an antenna 8 is disposed, wound in a loop shape and made of a coated conductor wire or the like. The card base 2 may refer to both the card before the recess 9 is formed and the card after the recess 9 is formed, and may refer to both the card with and without the antenna 8. Conductive plates 100 are welded to the start and end points of the antenna 8.

[0033] However, the layer structure of the card base 2 is not limited to this, and may be a three-layer structure of an over-sheet layer, a core layer, and an over-sheet layer, or a six-layer structure of an over-sheet layer, an intermediate layer, a core layer, a core layer, an intermediate layer, and an over-sheet layer. Multiple intermediate layers may be provided as appropriate. Printing or an embedded magnetic stripe may be provided on the surface of the over-sheet layer 3 or 6 of the card base 2 opposite the core layer 4 or 5, or printing may be provided on the surface of the core layer 4 or 5 adjacent to the over-sheet layer 3 or 6. In this embodiment, as shown in FIGS. 1( a) and 1(b), a printing layer 110 is provided as a concealing printing layer on the outer surface of the over-sheet layer 3, i.e., the surface on the +Z direction side, and a printing layer 120 is provided on the surface of the core layer 5 facing the over-sheet layer 6.

[0034] The printing layer 110, which is a concealing printing layer, is often used to conceal a magnetic stripe or the like (not shown) provided on the outside of the over-sheet layer 3, thereby preventing a loss of design. Such a printing layer 110 is composed of a concealing layer facing the center of the card base 2 and a picture printing layer facing the outside of the card base 2 relative to the concealing layer. The printing layer 110 can be formed on the over-sheet layer 3 by first providing it on a transfer sheet substrate (not shown), such as a PET film, via a release layer. The printing layer 110 on the transfer sheet substrate, together with the release layer, is then thermally transferred to the over-sheet layer 3 on the surface side. The concealing layer may include, for example, silver, black, gold, or red, and the silver concealing layer may include aluminum. The picture printing layer can also be obtained by applying inks of various colors to form a picture print. The concealing layer or picture printing layer of the printing layer 110 may be solid printed over the entire layer area, or may be solid printed or dot printed in partial areas. The printed layer 120 may have the same configuration as the printed layer 110, or may be configured with only the above-mentioned concealing layer or only the above-mentioned picture printed layer, which are formed with ink using a pigment. The printed layer 120 may be formed by solid printing on the entire layer area, or by solid printing or halftone printing on partial areas. The printed layer 120 may also include letters or symbols.

[0035] The release layer is obtained from an ink composed of a transparent material, and the ink that forms this release layer can be a mixture of components with the following composition: Resin 1 (acrylic resin) content 20-30%, Resin 2 (vinyl chloride-vinyl acetate resin) content 5% or less, and Resin 3 (polyester resin) content 1% or less. The content of ultraviolet absorber is also 2% or less, methyl ethyl ketone content 30-40%, toluene (300) content 34.0-36.0%, and polyethylene wax content 1% or less.

[0036] From the viewpoint of conforming to standards such as ISO / IEC 7810, the thickness of the card base 2 is preferably 0.76 mm or more and 0.84 mm or less, but may be outside this range.

[0037] (i) Core layer The core layers 4 and 5 can be biomass resin layers made of white or colored biomass resin. The biomass resin layer used in the present disclosure is made primarily from plant-derived isosorbide and has properties similar to those of polycarbonate resin, but does not contain bisphenol A, the main ingredient of ordinary polycarbonate resin. Furthermore, because the biomass resin layer is not a biodegradable polymer, it has excellent heat resistance, moisture resistance, and durability. Furthermore, because its softening temperature is within the same range as ordinary engineering plastic resins, existing manufacturing equipment such as heat presses can be used as is.

[0038] A method for producing an ISP sheet containing isosorbide polymer (ISP), which is a biomass resin layer having such properties, is described, for example, in Japanese Patent No. 4868083 and Japanese Patent No. 4868084, and is summarized as follows: Figure 3 is a structural formula illustrating the method for producing an ISP sheet containing the isosorbide polymer (ISP) of the present disclosure.

[0039] The biomass resin layer of the present disclosure is a sheet-shaped resin similar to polycarbonate resin, which is produced by polycondensation in multiple stages through transesterification in multiple reactors using a catalyst and a diester carbonate and a dihydroxy compound as raw material monomers. The dihydroxy compound is, for example, isosorbide, which is a stereoisomeric compound. Furthermore, as a raw material monomer, at least one compound selected from the group consisting of aliphatic dihydroxy compounds and alicyclic dihydroxy compounds is used to improve the color of the polycarbonate resin. For example, 1,4-cyclohexanedimethanol, an alicyclic dihydroxy compound, is preferably used. Furthermore, diphenyl carbonate is preferably used as the diester carbonate.

[0040] To rephrase the manufacturing method of this biomass resin layer, first, glucose (grape sugar) is reduced and the aldehyde group is converted to a hydroxy group to obtain sorbitol. This is then dehydrated and cyclized to produce isosorbide monomer. Next, the isosorbide monomer and diphenyl carbonate (DPC) are reacted by a melting method (melt transesterification) to produce the resin ISP. Next, the ISP and 1,4-cyclohexanedimethanol (hereinafter also referred to as "CHDM") are reacted to produce an ISP sheet containing ISP and CHDM.

[0041] In such a biomass resin layer, the ratio of isosorbide in the isosorbide and 1,4-cyclohexanedimethanol in the isosorbide polymer sheet is preferably 40 mol % or more and 70 mol % or less, because this range allows the required physical properties and durability of an IC card to be comparable to those of typical card resins such as polyvinyl chloride, PET-G, and polycarbonate.

[0042] The thickness of the core layer sheet can be selected appropriately taking into consideration the overall thickness of the card, but can be, for example, about 0.10 mm or more and 0.38 mm or less. As will be described later, antenna 8 must be placed on the surface of one of the opposing core layers 4 and 5 by applying heat and pressure so that it is sandwiched between the two layers.

[0043] For example, an antenna 8 is formed on one surface of the core layer 5, and conductive plates 100 are welded to both ends of the antenna wire that constitutes the antenna 8. The formation of the antenna 8 on the core layer 5 is performed by applying a predetermined heat and pressure to the antenna wire to embed it in the core layer 5. The intermediate product in which the antenna 8 is embedded in the core layer 5 is sometimes referred to as an antenna sheet 12. The antenna sheet 12 can be distributed on the market by itself as a component for manufacturing an IC card 1 that is a dual interface IC card. Furthermore, there may be a commercial form in which a sheet material such as the core layer 5 is supplied to a processor, who processes it into an antenna sheet 12 and delivers it to the supplier.

[0044] The method for forming the antenna sheet 12 will be described in detail later, but can be summarized as follows. First, a coated conductor coated with an insulating material is embedded in the surface of the core layer 5, starting from one end and ending at the other, using a winding former. That is, while applying a predetermined heat and pressure to the core layer 5, an antenna supply head is drawn into a loop shape as shown in FIG. 1(a), and the antenna wire supplied from the antenna supply head is sequentially embedded in the core layer 5. In addition, either before or after embedding the antenna wire, a pair of conductive plates 100 is attached to predetermined positions on the core layer 5 with an adhesive or the like.

[0045] Here, both ends of the antenna wire are welded to the conductive plate 100 for electrical connection. Then, the winding machine cuts the antenna wire at the start and end points of the antenna 8. In this way, the antenna sheet 12 is completed.

[0046] (ii) Oversheet layer As shown in FIG. 2(a), either or both of the oversheet layers 3 and 6 have a three-layer laminate structure. Taking the oversheet layer 3 as an example, the oversheet layer 3 has a first layer 31 on the surface where the external connection terminal 71 of the IC card 1 is exposed, and a second layer 32 and a third layer 33 laminated in this order below it, i.e., toward the -Z direction. The first layer 31 and the third layer 33 are biomass resin layers with the same structure as described above, and the second layer 32 is, for example, a polycarbonate resin layer. The second layer 32 can also be a plastic resin layer commonly used as a card substrate, such as a polyvinyl chloride layer or a PET-G layer. The oversheet layers 3 and 6 may have a multi-layer structure with more than three layers, such as four or five layers.

[0047] By using a polycarbonate resin layer for the second layer 32, which has a relatively higher softening point and harder properties than the biomass resin layer, it is expected that the physical properties, bending strength, and durability of the IC card 1 will be improved, as described below. For example, a card made only of a white core layer composed only of biomass resin layers and a card made only of a transparent over-sheet layer with a three-layer structure in which a polycarbonate resin layer is sandwiched between biomass resin layers were subjected to a dynamic bending force test of 5.8 of JIS X6305-1 (2010) for five cards of each type. The card thicknesses were within the standard range of 0.76 mm to 0.78 mm. As a result, the former card began to develop microcracks between 40,000 and 45,000 cycles, while the latter card began to develop microcracks between 95,000 and 100,000 cycles. As is clear from these results, the latter card has higher bending strength and bending durability than the former card. In addition, the unevenness of the antenna 8 placed inside the IC card 1 is prevented from becoming apparent on the surface of the over-sheet layers 3 and 6 through the core layers 4 and 5, which are relatively flexible materials, and it is expected that the front and back surfaces of the IC card 1 can be made relatively smooth.

[0048] On the other hand, by making the second layer 32 a polyvinyl chloride resin layer that has a softening point relatively lower and more flexible than the biomass resin layer, it is possible to expect, for example, to improve the embossing suitability of the IC card 1, absorb protrusions of the magnetic stripe embedded in the over-sheet layer 3, and smooth the front and back surfaces. Also, if the second layer 32 is a PET-G resin layer that has a softening point and flexibility roughly equivalent to those of the biomass resin layer, it is possible to expect an intermediate effect between the polycarbonate resin layer and the polyvinyl chloride resin layer described above.

[0049] In other words, the over-sheet layer 3 has a three-layer structure, with a biomass resin layer and a different resin layer sandwiched between them on both the top and bottom sides along the thickness direction. For example, the three-layer over-sheet layer 3 can be formed as a single sheet by co-extrusion, or the three layers can be prepared as separate sheets and laminated together by hot pressing. The thickness of the over-sheet layers 3 and 6 can be, for example, 0.05 mm or more and 0.10 mm or less.

[0050] The over-sheet layers 3 and 6 may be composed of four or more layers, and may be formed by co-extrusion. Alternatively, each layer may be prepared as a separate sheet. When the over-sheet layers 3 and 6 have a laminated structure of four or more layers, it is preferable that at least the front and back surfaces of the laminated structure are biomass resin layers. The over-sheet layers 3 and 6 formed by co-extrusion have a different degree of fusion between the three layers than when the three layers are prepared as separate layers and then laminated and integrated by heat pressing. That is, when formed by co-extrusion, the layers are heated at a temperature above their melting points, so the layers are relatively strongly fused together, making interlayer separation difficult. On the other hand, when the layers are laminated as separate layers and integrated by heat pressing, the layers are fused together at a heating temperature slightly above their glass transition points (Tg) during heat pressing, so the layers are relatively weakly fused together, making interlayer separation more likely. Therefore, by preparing both samples and conducting comparative tests of interlayer separation at room temperature, after heating to near Tg, or after immersion in some kind of chemical, it is possible to determine whether the oversheet layers of cards on the market are formed by co-extrusion or whether they are laminated as separate layers and integrated by heat pressing.The interlayer separation test may be conducted in accordance with, for example, 5.3 Peel Strength of JISX6305-1(2010), or any other test method.

[0051] Furthermore, the outermost surfaces of the biomass resin layers of the oversheet layers 3 and 6 that make up the front and back surfaces of the IC card 1 are preferably subjected to surface treatment to improve suitability for various prints, thermal transfer of coloring materials from ink ribbons, and thermal transfer of holograms, sign panels, etc. This can be achieved, for example, by coating with ink containing a vinyl chloride-vinyl acetate (vinyl chloride-vinyl acetate) copolymer resin. In this case, the presence or absence of vinyl chloride-vinyl acetate ink can be determined by the appearance of a chlorine component peak when infrared spectroscopy (IR) is used to obtain a spectrum of the front or back surface of the IC card 1.

[0052] Whether the over-sheet layers 3 and 6 have a single-layer structure of a biomass resin layer or the above-mentioned three-layer structure, they are preferably transparent enough to allow the design of the printed layer or the like formed on the surface of the core layers 4 and 5 located in the center of the card base 2 to be visible. By making the over-sheet layers 3 and 6 transparent, the characters and designs printed or the like on the surface of the core layers 4 and 5 can be clearly seen, and this printing or the like can be protected, thereby improving the design and added value of the IC card 1.

[0053] The over-sheet layers 3 and 6 may be transparent if, for example, they have a transmittance of 30% or more when visible light having a wavelength of 380 nm or more and 780 nm or less is incident along the thickness direction. However, a transmittance of 50% or more is more preferable, and a transmittance of 70% or more is even more preferable. This is because the higher the transmittance, the more the design of the IC card 1 can be improved. In the case of a three-layer structure, the transmittance can be the transmittance of all three layers. It goes without saying that the over-sheet layers 3 and 6 are not limited to being colorless, but may also have some color.

[0054] When the IC card 1 is used as a magnetic card, a magnetic stripe may be embedded in advance in one or both of the over-sheet layers 3 and 6 on the main surface opposite the core layers 4 and 5 by thermal transfer or the like.

[0055] As another variation, at least one of the over-sheet layers 3 and 6 may be a laser-coloring layer, in which at least one of the three layers contains a laser-coloring agent that changes color upon laser irradiation. Examples of such over-sheet layers 3a and 6a are shown in Figures 2(b) and 2(c). In the over-sheet layers 3a and 6a, the second layer 32a is the laser-coloring layer. For example, as shown in Figure 2(c), when laser light L of a predetermined wavelength is irradiated onto the over-sheet layer 3a or 6a, the laser light L is transmitted through the first layer 31 and the third layer 33, but is absorbed by the second layer 32a, resulting in the marking of a predetermined coloring portion 130. As a result, for example, predetermined characters or patterns corresponding to the marking area can be visually recognized.

[0056] The laser coloring layer containing a laser light coloring agent is a layer that develops a predetermined color when irradiated with infrared laser light, for example, with a wavelength of 700 nm or more and 1200 nm or less, and can be created by adding the desired additive to the base material of a normal second layer.

[0057] The additive that absorbs laser light and develops color may be, for example, at least one selected from the group consisting of carbon black, titanium black, metal oxides, metal sulfides, and metal nitrides. When the laser light energy absorber is carbon black, the average particle size is preferably 150 nm or less, more preferably 100 nm or less, and even more preferably 90 nm or less.

[0058] Titanium black and metal oxides preferably have an average particle size of 10 μm or less, since this maintains laser color development and print clarity. Metals that form oxides include zinc, magnesium, aluminum, iron, titanium, silicon, antimony, tin, copper, manganese, cobalt, bismuth, vanadium, niobium, molybdenum, ruthenium, tungsten, palladium, silver, and platinum. Composite metal oxides include ITO, ATO, and AZO. Metal sulfides include zinc sulfide and cadmium sulfide. Metal nitrides include titanium nitride. Leuco dyes and color developers, such as fluoran-based, phenothiazine-based, spiropyran-based, triphenylmethaphthalide-based, and rhodamine lactam-based dyes, may also be used.

[0059] These materials can be added to the ordinary resin that constitutes the second layer to form a film, resulting in the second layer 32a, which is the laser coloring layer. These materials can be selected based on factors such as the wavelength range of the laser light used, and the amount added can be determined based on factors such as energy absorption efficiency, printability on the laser coloring layer, transferability, and physical properties. The above explanation assumes that the second layer 32a contains an additive that absorbs laser light of a specific wavelength and develops color. However, the laser coloring layer is not limited to this method. Other methods that produce color include foaming of the resin in the second layer 32a due to heat generated by laser irradiation, or carbonizing the surrounding resin by absorbing laser light and generating heat from the additive, resulting in color development.

[0060] In this way, the oversheet layers 3a and 6a have a three-layer structure, and the second layer 32a, which is made of a resin used in ordinary card substrates, is given the laser coloring function. In other words, instead of directly coloring the biomass resin layer with laser light, the oversheet layers 3a and 6a are configured to color an ordinary card substrate that has already proven itself as a laser coloring substrate. Therefore, there is no need to develop or evaluate a new substrate for the laser coloring layer, and coloring can be easily achieved using a structure similar to that of conventional coloring layers.

[0061] It is preferable that the weight percentage of the biomass-derived components in the entire laminate including the IC module 7 and the antenna 8 is 10% or more and 45% or less. By having the weight percentage of the biomass-derived components in this range, the biomass-derived components are contained at a certain weight ratio or more of the IC card 1, which improves the effect of reducing the environmental burden. Furthermore, by having the weight percentage of the biomass-derived components be below a certain level, it is possible to ensure the standards required for the IC card 1, as well as the durability and physical properties in actual use, and the reliability of the IC card 1. Details regarding the definition of biomass-derived components are provided, for example, by the Japan Bioplastics Association.

[0062] Specifically, in this embodiment, the weight percentage (percentage) of biomass-derived components in each layer constituting the card base 2 is approximately 34% for the core layers 4 and 5, and approximately 14% for the over-sheet layers 3 and 6. Looking at the card base 2 as a whole, it is approximately 27%. Furthermore, the specific gravity of the biomass resin layer differs from that of other resin layers in typical card substrates. That is, in this embodiment, the specific gravity of the biomass resin layer is 1.42 for the white core layers 4 and 5, and 1.27 for the transparent over-sheet layers 3 and 6. In contrast, the specific gravity of polycarbonate resin, which has a similar composition, is 1.30 for the white layers and 1.20 for the transparent layers. Furthermore, the specific gravity of PET-G resin is 1.40 for the white layers and 1.25 for the transparent layers. These differences in specific gravity also make it possible to identify the materials used to some extent.

[0063] (iii) Antenna The antenna 8 formed on the core layer 5 has a pair of conductive plates 100 at its end electrically connected to terminals 73a and 73b of the IC module 7, respectively, so that the IC chip of the IC module 7 and the antenna 8 form a communication circuit for contactless communication. The communication circuit may be one that performs close-proximity communication using, for example, the 13.56 MHz HF frequency band specified in ISO / IEC 144443 or the like. Alternatively, it may be one that performs communication using other frequency bands, such as the 920 MHz UHF frequency band, the 125 kHz LF frequency band, or the 2.45 GHz microwave frequency band.

[0064] When IC card 1 is held over an external device such as a reader / writer, a current is generated in the communication circuit due to the magnetic field generated by the reader / writer, and power is supplied to the IC chip. This enables the IC chip to be driven, enabling contactless transmission and reception of information with the reader / writer, and reading and rewriting of information from and to the memory.

[0065] The antenna wire constituting the antenna 8 is typically formed of a coated conductor wire, which is a copper wire coated with an insulating material. Alternatively, copper alloy wires such as Cu-Ni, Cu-Cr, Cu-Zn, Cu-Sn, and Cu-Be, or various metal wires and metal alloy wires such as iron, stainless steel, and aluminum can also be selected. By using a coated conductor wire, the IC card 1 can be manufactured more inexpensively than, for example, a copper foil etching method.

[0066] The diameter of the antenna wire is not particularly limited as long as it can ensure the characteristics required for a contactless communication circuit, but it can be, for example, 0.03 mm to 0.30 mm, and preferably 0.05 mm to 0.15 mm. By setting the diameter in the latter range, durability against heat and pressure during embedding and external forces due to cutting can be improved, ensuring good communication characteristics.

[0067] In the present embodiment, a pair of conductive plates 100 are welded to both ends of the antenna wire of the antenna 8, and the conductive plates 100 are electrically connected to the terminals 73a and 73b of the IC module 7 via the conductive adhesive layers 10, respectively. However, the configuration of the antenna 8 of the IC card 1 of the present disclosure is not limited to this. For example, both ends of the antenna 8 may not have conductive plates, and each end of the antenna wire may form a zigzag-shaped or bellows-shaped portion, so that the portion performs the same function as a conductive plate.

[0068] The IC module 7 may also have a small first coupling coil antenna electrically connected to the IC chip formed on the surface of the substrate 72 opposite the external connection terminal 71. In this case, the antenna 8 disposed inside the card base 2 includes a loop antenna along the outer periphery of the card base 2 and a second coupling coil formed opposite the first coupling coil of the IC module 7. The loop antenna and the second coupling coil are electrically connected, forming a closed loop. That is, the antenna 8 is not physically connected to the IC module 7. With this configuration, the IC module 7 transmits power and signals received by the loop antenna to the second coupling coil, and then transmits the power and signals to the IC module 7 by magnetically coupling the second coupling coil and the first coupling coil. That is, the IC card 1 can also operate using this booster antenna system.

[0069] (b) IC module Next, each of the main components of the IC module 7 will be described mainly with reference to Figures 1(b) and 4. Figure 4(a) is a view of the external connection terminals 71 of the IC module 7 viewed from the +Z direction, similar to Figure 1(a). Figure 4(b) is a view of the IC module 7 viewed from the -Z direction, opposite to Figure 4(a). Most of the molded portion 74b of the IC chip body 74 has been omitted here to allow a see-through view of the interior.

[0070] The IC module 7 is embedded in a recess 9 formed in the card base 2, and terminals 73a and 73b of the IC module 7 are electrically connected to a pair of conductive plates 100 at both ends of the antenna 8, thereby forming a communication circuit for contactless communication. Furthermore, contact communication with a contact-type reader / writer or the like can be performed through an external connection terminal 71 provided on the IC module 7.

[0071] Substrate 72 is formed by bonding copper foil to the front and back of a flexible insulating resin film, such as glass epoxy resin or polyimide resin, with an adhesive, and leaving the copper foil on the front and back of the resin film so as to form a predetermined pattern. Specifically, a photosensitive material is applied, a film plate with a predetermined pattern is placed, exposed, and the non-photosensitive portion is etched away to form external connection terminal 71 on one copper foil surface of the resin film and terminals 73a and 73b on the other copper foil surface. This process sequentially forms substrate 72, with copper foil remaining in the predetermined pattern on the front and back of the resin film. Substrate 72 also has a plurality of bonding holes 76, which are through-holes for wire bonding to external connection terminal 71, pre-formed in the substrate.

[0072] There is no particular limit to the thickness of the substrate 72, but taking into consideration that it can follow the bending of the card base 2 to some extent, it can be, for example, 0.03 mm or more and 0.50 mm or less, and preferably 0.07 mm or more and 0.20 mm or less.

[0073] As shown in Fig. 4(a), the external connection terminal 71 has sections defined for the external terminal as defined by the ISO / IEC 7816-2 standard. As shown in Fig. 4(b), these sections are connected to the IC chip 74a by wires 75 such as gold wires through the bonding holes 76 provided in the substrate 72. Similarly, the terminals 73a and 73b are connected to the IC chip 74a by wires 75. These bonding holes 76 and wires 75 are covered and protected by the molded portion 74b.

[0074] An IC chip body 74 is disposed on the surface of the substrate 72 opposite to the surface on which the external connection terminals 71 are formed. The IC chip body 74 is composed of an IC chip 74a adhered and fixed to the substrate 72 with an adhesive, bonding wires 75 for connection, and a molded portion 74b made of sealing resin for protecting these. The IC chip 74a includes a CPU for controlling both contact and contactless communication operations, and storage devices such as RAM, ROM, EEPROM, and flash memory. The IC chip 74a also includes various circuits, such as an interface circuit for decoding input signals and generating output signals for contact and contactless communication, and a power generation circuit. Note that these various circuits may be provided as elements separate from the IC chip 74a.

[0075] The molded portion 74b is provided as a protruding portion that covers the IC chip 74a and the wires 75 to protect them from external force loads and environmental loads. An insulating ultraviolet curable resin, a thermosetting resin, or the like is used for the molded portion 74b.

[0076] The thickness of the IC chip body 74 may be, for example, 0.45 mm to 0.75 mm, depending on the thickness of the IC chip 74a provided therein and the shape of the bonded wires. The total thickness of the IC module 7 may be, for example, 0.35 mm to 1.0 mm, and preferably 0.40 mm to 0.65 mm. The latter range allows the depth of the second recess 9b to be 0.7 mm or less, thereby keeping the total thickness of the dual interface IC card 1 to 0.84 mm or less, as defined by the ISO / IEC 7810 standard.

[0077] (c) Conductive adhesive layer After forming a recess 9 for embedding an IC module 7 in the card base 2 by cutting or the like using an end mill, the conductive adhesive layer 10 is embedded and fixed in the recess 9, and electrically and mechanically connected to the IC module 7. As shown in FIG. 1(b), the conductive adhesive layer 10 is disposed so as to be sandwiched between the core layer 4 in the portion where the surface of the conductive plate 100 is exposed in the third recess 9c of the recess 9, and the terminals 73a and 73b formed on the substrate 72 of the IC module 7 embedded and disposed above it. The conductive adhesive layer 10 is a liquid or tape-like member.

[0078] The conductive adhesive layer 10 may be applied or filled into the third recess 9c after cutting the recess 9 in the card base 2. Furthermore, if the conductive adhesive layer 10 is in the form of a tape, it may be laminated in advance on the surface of the substrate 72 of the IC module 7 opposite to the external connection terminal 71.

[0079] The conductive adhesive layer 10, which is liquid and heat-cured, can be a so-called conductive paste, which is made by dispersing silver particles as a filler in an epoxy resin. Alternatively, an anisotropic conductive paste (ACP), which is made by dispersing conductive particles with a metal film formed around spherical resin or metal spheres in an adhesive, which is a binder containing an insulating adhesive component, or solder can be used.

[0080] On the other hand, as a tape-shaped adhesive for the conductive adhesive layer 10, a tape-shaped anisotropic conductive film (ACF) containing components equivalent to those of the above-mentioned ACP can be used.

[0081] When the above-described conductive paste is used as the conductive adhesive layer 10, after filling the third recess 9c with the conductive adhesive layer 10, the conductive adhesive layer 10 can be thermally cured by applying heat and pressure from the external connection terminal 71 side of the IC module 7. As a result, the IC chip 74a and the antenna 8 are electrically connected.

[0082] (d) Recess The recess 9 formed in the card base 2 for embedding the IC module 7 has a first recess 9a formed along the outer periphery. The recess 9 also has a second recess 9b deeper than the first recess 9a on the central side surrounded by the first recess 9a. The recess 9 further has a third recess 9c deeper than the first recess 9a but shallower than the second recess 9b, located outside the outer periphery of the second recess 9b and in part of the area surrounded by the first recess 9a.

[0083] The first recess 9a is provided to accommodate the flat substrate 72 of the IC module 7, and the second recess 9b is provided to accommodate the protruding portion of the IC chip body 74. The third recess 9c is provided as an area to be filled with the conductive adhesive layer 10 for electrically connecting the IC module 7 and the antenna 8, as described above.

[0084] (e) IC card manufacturing method Next, an example of a method for manufacturing IC card 1, which is a dual interface IC card, using card base 2 having core layers 4 and 5, oversheet layers 3 and 6, IC module 7, and conductive adhesive layer 10 will be described.

[0085] First, the necessary components for constructing the card base 2 and IC card 1 are prepared, including core layers 4 and 5 containing a biomass resin layer, three-layer over-sheet layers 3 and 6 also containing a biomass resin layer, and IC module 7. In this embodiment, the core layers 4 and 5 and the over-sheet layers 3 and 6 have the same configuration. The over-sheet layers 3 and 6 are laminated sheets that are co-extruded to have a three-layer configuration, with the second layer 32 being polycarbonate.

[0086] Next, a pair of conductive plates 100 are attached in advance to predetermined positions on the surface of the core layer 5 facing the core layer 4, using an adhesive or the like. Next, a coated conductor wire coated with an insulating material is embedded as an antenna wire using a winding former, starting from the position of one conductive plate 100 and ending at the position of the other conductive plate 100. Specifically, for example, while applying a predetermined heat and pressure to the core layer 5, an antenna supply head is drawn into a loop shape as shown in FIG. 1(a), and the antenna wire supplied from the antenna supply head is sequentially embedded in the core layer 5. Thereafter, both ends of the antenna wire are welded to the pair of conductive plates 100, and the remaining excess portion of the antenna wire is cut off.

[0087] Next, using the core layer 5, which is the antenna sheet 12 on which the conductive plate 100 and the antenna 8 are formed, the over-sheet layer 6, core layer 5, core layer 4, and over-sheet layer 3 are stacked in this order from the bottom in the thickness direction, as shown in Figure 1(b). After that, the stacked unit of the large sheet on which the cards are arranged in multiple faces lengthwise and widthwise is sandwiched between stainless steel plates from above and below in the thickness direction, and heat and pressure are applied to the stacked intermediate product via the stainless steel plates.

[0088] By undergoing this heat pressing process, a large-sized sheet-unit card base can be obtained in which the layers of the laminated intermediate product are integrated. Furthermore, if either the oversheet layers 3, 6 or the core layers 4, 5 are heat-resistant and do not heat-seal at a predetermined temperature, the following method can be used. Specifically, an adhesive sheet that heat-seals at a predetermined temperature is sandwiched between the layers, or an adhesive is applied, and then these are subjected to a heat pressing process to obtain an integrated large-sized sheet-unit card base. This is shown in Figure 5(a) as card base 2, which is a card unit.

[0089] Here, the surfaces of the core layer 4 and the core layer 5, the core layer 5 and the over-sheet layer 6, and the core layer 4 and the over-sheet layer 3 that face each other during heat pressing are all identical biomass resin layers. While the exact reasons are unclear, it is known that the biomass resin layer of the present disclosure is relatively easy to heat-seal with a polycarbonate resin layer that has a high softening temperature, but relatively difficult to heat-seal with a PET-G resin sheet that has a lower softening temperature. Furthermore, it goes without saying that heat-sealing between identical biomass resin layers is also easy. The softening temperature of the biomass resin layer is between 90°C and 105°C.

[0090] Therefore, in this embodiment, adjacent surface portions become the same biomass resin layer during lamination, making fusion failure during the heat-pressing process less likely to occur. This does not pose any particular manufacturing difficulties compared to heat-fusing polycarbonate resin layers, which are commonly used as base materials for cards, such as vinyl chloride resin sheets and PET-G resin sheets. Therefore, production is possible without any significant changes to manufacturing equipment conditions, as with conventional products. Furthermore, in this embodiment, a polycarbonate resin layer is used as the second layer 32 of the over-sheet layers 3 and 6. However, the over-sheet layers 3 and 6 are pre-formed into a three-layer structure by co-extrusion molding. Therefore, when laminating and heat-pressing the core layers 4 and 5 of the card base 2 and the over-sheet layers 3 and 6, lamination and integration can be easily achieved by simply heating them above the softening temperature of the biomass resin layer, which is a relatively low temperature. As a result, there is no need to significantly increase the heating temperature, thereby saving energy and processing time during processing.

[0091] Furthermore, in this embodiment, the second layer 32 of the over-sheet layer 3 or 6 is made of a polycarbonate resin, which is a relatively hard material with a high softening temperature. This reduces the likelihood that the irregularities of the antenna 8 will be apparent as irregularities on the surface of the over-sheet layer 3 or 6 through the core layer 4 or 5, which is made of a relatively flexible material. As a result, the surfaces of the over-sheet layer 3 or 6 become relatively smooth, improving the design and appearance quality of the IC card 1. Specifically, if the surface of the IC card 1 becomes wavy, or if printing is performed on the surface, cracks in the ink coating due to the influence of surface irregularities (pattern cracking) can be suppressed. Furthermore, the reinforcing effect of the second layer 32 is expected to improve the bending durability of the IC card 1.

[0092] The large-sized card substrate obtained as described above, as shown in FIG. 5(a), on which cards are arranged in a multi-faced array, is punched out by a punching machine into card substrate 2 that meets the ISO / IEC 7810 card size. In addition, recesses 9 for embedding IC modules 7 are formed in the card substrate 2 by cutting using an end mill. This results in the cut card substrate 2 shown in FIG. 5(b). As described above, the recesses 9 have three depth levels: first recess 9a, second recess 9b, and third recess 9c.

[0093] Thereafter, a liquid conductive paste, which is the conductive adhesive layer 10, is applied to and filled into the third recess 9c of the recess 9 on the card base 2 in which the recess 9 has been formed. Then, the IC module 7 is embedded thereon, and a predetermined heat block is pressed against the external connection terminal 71, and a predetermined heat pressure is applied toward the card base 2 for a predetermined time. This thermally hardens the conductive adhesive layer 10, establishing electrical connection between the terminals 73a and 73b of the IC module 7 and the conductive plates 100 on both ends of the antenna 8. This completes the IC card 1.

[0094] (f) Regarding the IC card of the first embodiment To summarize the above, IC card 1, which is a dual interface IC card of the first embodiment, is a laminated body with a built-in IC module 7. IC card 1 includes antenna 8 connected to IC module 7, a pair of core layers 4 and 5 that sandwich antenna 8, and a pair of transparent over-sheet layers 3 and 6 on the outside of the pair of core layers 4 and 5. The core layers 4 and 5 and the over-sheet layers 3 and 6 include biomass resin layers. At least one of the pair of over-sheet layers 3 and 6 is composed of multiple layers, with the biomass resin layer laminated on both sides of a resin layer that is different from the biomass resin layer in question.

[0095] As a result, the IC card 1 contains a certain amount of biomass resin components, which are plant-derived materials, thereby reducing the environmental impact. Furthermore, the over-sheet layers 3 and 6 have a three-layer structure with a different resin layer sandwiched between two biomass resin layers. Therefore, compared to cards composed solely of biomass resin layers, it is possible to adjust the physical properties, strength, and quality of the IC card 1 by appropriately selecting the components of the different resin layers. Even with this structure, when the over-sheet layers 3 and 6 are formed into sheets by co-extrusion molding of a three-layer structure, the following can be said about the process of laminating the core layers 4 and 5 and the over-sheet layers 3 and 6 and integrating them by applying heat and pressure. In other words, in this process, the opposing surfaces become the same biomass resin layer, making it relatively easy to laminate and integrate them by heat fusion.

[0096] 2. Second embodiment Next, an IC card 1a that is a laminate according to a second embodiment of the present disclosure will be described.

[0097] FIG. 6(a) is a cross-sectional view corresponding to FIG. 1(b) of an IC card 1a, which is a dual-interface IC card of a second embodiment. The IC card 1a is also an example of a laminate of the present disclosure. The IC card 1a of the second embodiment differs from the IC card 1 of the first embodiment in that a first intermediate layer 42 and a second intermediate layer 43 are laminated between a core layer 41 corresponding to the core layer 4 and an over-sheet layer 3. The IC card 1a also differs in that a first intermediate layer 52 and a second intermediate layer 53 are laminated between a core layer 51 corresponding to the core layer 5 and an over-sheet layer 6. Furthermore, at least one of the first intermediate layers 42 and 52 has the same structure as the over-sheet layers 3 and 6, i.e., a three-layer structure in which a different resin layer is sandwiched between two biomass resin layers.

[0098] In this embodiment, the over-sheet layers 3 and 6 have the same three-layer structure, and the first intermediate layers 42 and 52 also have a similar three-layer structure. Figure 6(b) is a cross-sectional view corresponding to Figure 2(a) that explains the layer structure of the first intermediate layers 42 and 52 in addition to the over-sheet layers 3 and 6 of the IC card 1a. That is, in this embodiment, the first intermediate layers 42 and 52 also have the same three-layer structure of a first layer 31, a second layer 32, and a third layer 33 as the over-sheet layers 3 and 6.

[0099] Furthermore, the second intermediate layers 43 and 53 have the same configuration as the core layers 41 and 51, except for their thickness. However, the IC card 1a is not limited to this configuration; only one of the over-sheet layers 3 and 6 may have a three-layer configuration, and only one of the first intermediate layers 42 and 52 may have a similar three-layer configuration. Furthermore, the second intermediate layers 43 and 53 may have a different configuration from the core layers 41 and 51. This is because the effects expected of this embodiment can be similarly achieved with such a configuration.

[0100] The configuration of the over-sheet layers 3, 6 and first intermediate layers 42, 52 of a typical IC card 1a is as shown in Fig. 6(b). That is, the first layer 31 and the third layer 33 are the biomass resin layers described above, and the second layer 32 is, for example, a polycarbonate resin layer. As in the first embodiment, the second layer 32 can also be a plastic resin layer used as a general card substrate, such as a polyvinyl chloride layer or a PET-G layer.

[0101] By using a polycarbonate resin layer with a softening point relatively higher and harder than that of the biomass resin layer for the second layer 32, it is possible to arrange two different resin layers different from the biomass resin layer in two locations in the section from the center of the thickness direction of the IC card 1a to the outermost surface. This is expected to improve the physical properties, bending strength, and durability of the IC card 1a, and also allows the polycarbonate resin layer to be arranged at a point relatively close to the center and close to the antenna 8 in the thickness direction. This allows unevenness caused by the antenna 8 to be suppressed just outside the core layers 41, 51, which are relatively flexible members, further improving the unevenness suppression effect provided by the polycarbonate resin layers contained in the over-sheet layers 3, 6.

[0102] On the other hand, by using a polyvinyl chloride resin layer for the second layer 32, which has a softening point relatively lower than that of the biomass resin layer and is more flexible, the following effects can be expected. For example, it is possible to improve the embossing suitability of the IC card 1a, absorb protrusions of the magnetic stripe embedded in the over-sheet layer, and further smooth the front and back surfaces. Furthermore, even if the second layer 32 is a PET-G resin layer, which has a softening point and flexibility roughly equivalent to that of the biomass resin layer, it is possible to further expect the intermediate effects of the polycarbonate resin layer and the polyvinyl chloride resin layer described above.

[0103] As described above, this embodiment has the same configuration and manufacturing method as the first embodiment, except for the addition of the first intermediate layers 42, 52 and second intermediate layers 43, 53, and therefore detailed description thereof will be omitted.

[0104] The IC card 1a of the second embodiment has the above-described configuration, which allows the IC card 1a to contain a certain amount of biomass resin components, which are plant-derived materials, thereby reducing environmental impact. Furthermore, by having a similar three-layer configuration for the over-sheet layers 3 and 6 as well as the first intermediate layers 42 and 52, resin layers different from the biomass resin layer can be positioned not only near the outermost surface of the IC card 1a but also near the center in the thickness direction. As a result, even if the IC card 1a has a multi-layer configuration, the over-sheet layers 3 and 6 and the first intermediate layers 42 and 52, which are part of the IC card's configuration, can have a common, compatible configuration. This reduces the number of material types and simplifies purchasing and inventory management. In particular, while the first intermediate layers 42 and 52 do not need to be transparent for functional reasons, making them transparent allows them to be compatible with the over-sheet layers 3 and 6.

[0105] This makes it easier to adjust the physical properties, strength, and quality of the IC card 1a by appropriately selecting the components of the different resin layers, compared to cards composed only of biomass resin layers or cards in which a different resin layer is disposed only in the over-sheet layer. Even with this configuration, if the over-sheet layers 3, 6 and the first intermediate layers 42, 52 are all formed into a sheet by co-extrusion molding into a three-layer structure, the following occurs. That is, in the process of laminating the core layers 41, 51 and the first intermediate layers 42, 52 and integrating them by applying heat and pressure, at least the surfaces facing each other become the same biomass resin layer. This allows for relatively easy lamination and integration by heat fusion.

[0106] Furthermore, when the second intermediate layers 43, 53 are biomass resin layers similar to the core layers 41, 51, the mutually facing surfaces of the first intermediate layers 42, 52 and the second intermediate layers 43, 53, and the second intermediate layers 43, 53 and the over-sheet layers 3, 6 are also the same biomass resin layers. Therefore, in this case, during the heat pressing process, all mutually facing surfaces become the same biomass resin layers, making it even easier to laminate and integrate them by heat fusion.

[0107] It goes without saying that in this embodiment too, at least one of the over-sheet layers 3 and 6 may be provided with a laser coloring layer containing a laser light coloring agent as shown in Figures 2(b) and 2(c), which was described as a variation of the first embodiment.

[0108] 3. Third embodiment Next, a booklet 200, which is a laminate according to a third embodiment of the present disclosure, will be described.

[0109] Fig. 7(a) is a schematic perspective view illustrating a booklet 200 according to a third embodiment. Fig. 7(b) is a cross-sectional view of a data page 210 included in the booklet 200 of Fig. 7(a), taken along line BB along the Y axis parallel to the main surface of the data page 210, as viewed from the +X direction.

[0110] The booklet 200 refers to a booklet-like object formed by binding one edge of multiple pages together, such as a passport or a savings passbook. In this embodiment, the booklet 200 is a passport. The booklet 200 has a substantially rectangular front cover 220 and back cover 230, and one or more pages are sandwiched and bound between the front cover 220 and the back cover 230, and is configured to prevent each page from being removed fraudulently or carelessly.

[0111] The configuration of the data page 210 is substantially similar to that of the IC card 1 of the first embodiment. That is, the data page 210 corresponding to the card base 2 of the IC card 1 is formed by laminating an over-sheet layer 216, a core layer 215, a core layer 214, and an over-sheet layer 213, stacked together in this order from the -Z direction. Typically, the over-sheet layers 213 and 216 are made of transparent substrates, and the core layers 214 and 215 are made of white substrates, but this is not limiting. Furthermore, an antenna 240 and an IC module 250 are sandwiched between the core layers 214 and 215. Unlike the IC card 1, the data page 210 does not have anything equivalent to the external connection terminal 71 of the IC module 7; instead, the entire IC module 250 is embedded within the data page 210. Furthermore, both ends of the antenna 240 are directly welded to the electrical contacts of the IC module 250.

[0112] In this embodiment, the over-sheet layers 213 and 216 correspond to the over-sheet layers 3 and 6 of the IC card 1, and the core layers 214 and 215 correspond to the core layers 4 and 5. That is, the core layers 214 and 215 include a biomass resin layer, and at least one of the over-sheet layers 213 and 216 has a three-layer structure consisting of a first layer 31, a second layer 32, and a third layer 33, as shown in FIG. 2(a). The first layer 31 and the third layer 33 are the biomass resin layers described above, and the second layer 32 is a different resin layer, such as a polycarbonate resin layer. The booklet 200 of this embodiment also has the same layer structure as the IC card 1 of the first embodiment, and therefore the same effects can be achieved. Furthermore, the booklet 200 is not limited to this, and may have a layer structure similar to that of the second embodiment. Similarly, either the over-sheet layers 213 and 216 may have a laser coloring layer containing a laser light coloring agent.

[0113] In the first and second embodiments, the IC cards 1 and 1a exemplified as the laminate have both been described as dual-interface IC cards. However, the present disclosure is not limited to this, and the IC cards 1 and 1a may be contact IC cards that do not have an antenna 8 and have an IC module equipped with an external connection terminal and an IC chip embedded in the card base. Furthermore, as described in the third embodiment, the IC cards 1 and 1a may be contactless IC cards that do not have an external connection terminal and have the entire IC module embedded inside the card base. Furthermore, the laminate refers not only to IC cards but also to cards in general, including magnetic cards and ID cards that do not have an IC module. [Explanation of symbols]

[0114] 1, 1a IC card 2, 2a Card base 3, 3a, 6, 6a Oversheet layer 4, 5 Core layer 7 IC modules 8 Antennas 9 Recess 9a First recess 9b Second recess 9c Third recess 10 Conductive adhesive layer 12 Antenna sheet 31 1st layer 32, 32a 2nd layer 33 3rd layer 41, 51 Core layer 42, 52 First Middle Class 43, 53 Second middle class 70 IC modules 71 External connection terminal 72 PCB 73a, 73b terminal 74 IC chip body 74a IC chip 74b molded part 74p Pad 75 wire 76 Bonding Hole 100 Conductive Plate 110, 120 printing layer 130 Coloring section 200 booklet 210 data pages 213, 216 Oversheet layer 214, 215 Core layer 220 Cover 230 Back cover 240 Antenna 250 IC modules

Claims

1. In a laminate with an IC module built in, an antenna connected to the IC module; a pair of core layers sandwiching the antenna; a pair of transparent over-sheet layers on the outside of the pair of core layers; the core layer and the over-sheet layer each comprise a biomass resin layer; At least one of the pair of over-sheet layers is a laminate composed of multiple layers in which the biomass resin layer is laminated on both sides of a resin layer different from the biomass resin layer.

2. The laminate of claim 1 , wherein the multiple layers are coextruded laminate sheets.

3. an intermediate layer is further provided between either one of the pair of core layers or the pair of over-sheet layers; The laminate of claim 1 , wherein the intermediate layer comprises the plurality of layers.

4. The laminate according to claim 1 , wherein the different resin layer is a polycarbonate resin layer.

5. 4. The laminate according to claim 1, wherein the weight percentage of the biomass-derived component in the entire laminate including the IC module and the antenna is 10% or more and 45% or less.

6. The laminate according to claim 1 , wherein the softening temperature of the biomass resin layer is 90° C. or higher and 105° C. or lower.

7. The laminate according to any one of claims 1 to 3, wherein a picture printed layer is provided on a surface of at least one of the pair of over-sheet layers facing away from the core layer via a concealing layer.

8. The laminate according to claim 1 , wherein at least one of the pair of over-sheet layers contains a laser beam color-forming agent.

9. A card comprising a laminate according to any one of claims 1 to 3.

10. A booklet comprising the laminate according to any one of claims 1 to 3.

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