Recording medium and laminate

Abstract

Provided is a recording medium capable of improving peel strength between a recording layer and a resin layer. The recording medium includes two or more recording layers and one or more resin layers. The recording layer contains a first polycarbonate resin. The resin layer is disposed between the two recording layers. The resin layer contains a UV-curable resin and a second polycarbonate resin.

Description

Technical Field

[0001] The present disclosure relates to a recording medium and a laminate including the recording medium. Background Art

[0002] In recent years, recording media including a plurality of recording layers have been developed as recording media replacing printed matter. Patent Document 1 discloses a recording medium including a plurality of recording layers and a plurality of heat-insulating layers (resin layers) each of which is provided between the plurality of recording layers.

[0003] Reference List

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2018 / 092488 Summary of the invention

[0006] Problems to be solved by the present invention

[0007] However, in conventional recording media, the peel strength between the recording layer and the resin layer may be reduced depending on the material constituting the resin layer.

[0008] An object of the present disclosure is to provide a recording medium capable of increasing the peel strength between a recording layer and a resin layer, and a laminate including the recording medium.

[0009] Solution to the problem

[0010] In order to solve the above problems, a first recording medium according to the present disclosure includes:

[0011] two or more recording layers; and

[0012] One or more resin layers, wherein

[0013] Each recording layer comprises a first polycarbonate resin;

[0014] Each resin layer is disposed between two recording layers, and

[0015] Each resin layer contains an ultraviolet curable resin and a second polycarbonate resin.

[0016] A second recording medium according to the present disclosure includes:

[0017] two or more recording layers; and

[0018] One or more resin layers, wherein

[0019] Each recording layer comprises a first thermoplastic resin,

[0020] Each resin layer is disposed between two recording layers, and

[0021] Each resin layer contains an ultraviolet curable resin and a second thermoplastic resin of the same type as the first thermoplastic resin.

[0022] A first laminate according to the present disclosure includes:

[0023] Base material;

[0024] An intermediate layer, disposed on the substrate and having a receiving portion;

[0025] a recording medium disposed in the housing; and

[0026] A cover layer is disposed on the middle layer, wherein

[0027] The receiving portion is arranged in a portion of the plane of the intermediate layer,

[0028] The receiving portion is a through hole penetrating in the thickness direction of the intermediate layer or a recessed portion recessed in the thickness direction of the intermediate layer.

[0029] The base material, the intermediate layer and the cover layer comprise the same kind of resin material,

[0030] The base material and the intermediate layer are bonded to each other by fusion, and the intermediate layer and the cover layer are bonded to each other by fusion, and

[0031] The recording medium is the above-mentioned first recording medium or second recording medium.

[0032] A second laminate according to the present disclosure includes:

[0033] Base material;

[0034] Covering layer;

[0035] an intermediate layer disposed between the substrate and the cover layer and having a receiving portion; and

[0036] The recording medium is arranged in the receiving portion, wherein

[0037] The receiving portion is arranged in a planar portion of the intermediate layer,

[0038] The receiving portion is a through hole penetrating in the thickness direction of the intermediate layer or a recessed portion recessed in the thickness direction of the intermediate layer.

[0039] The substrate, the intermediate layer and the cover layer comprise the same kind of resin material,

[0040] The base material and the intermediate layer are bonded to each other by a thermal adhesive, and the intermediate layer and the cover layer are bonded to each other by a thermal adhesive, and

[0041] The recording medium is a first recording medium or a second recording medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a cross-sectional view showing an example of a configuration of a recording medium according to the first embodiment.

[0043] Figure 2 is a diagram of a test setup for a 90 degree peel test.

[0044] Figure 3 A is a diagram for explaining the preparation steps for the 90 degree peel test. Figure 3 B is a diagram of a test setup for a 90 degree peel test.

[0045] Figure 4 is a cross-sectional view showing an example of a configuration of a recording medium according to the second embodiment.

[0046] Figure 5 A is a plan view showing an example of the appearance of a card according to Application Example 1. Figure 5 B is along Figure 5 A is a cross-sectional view taken along line VB-VB.

[0047] Figure 6 is a cross-sectional view showing an example of a configuration of a card according to Modification 1 of Application Example 1.

[0048] Figure 7 is a cross-sectional view showing an example of a configuration of a card according to Modification 2 of Application Example 1.

[0049] Figure 8 A is a cross-sectional view showing an example of the appearance of a card according to Modification 3 of Application Example 1. Figure 8 B is along Figure 8 A cross-sectional view taken along line VIIIB-VIIIB.

[0050] Fig. 9 is a cross-sectional view showing an example of a configuration of a card according to Application Example 2.

[0051] Fig.10 is a cross-sectional view showing an example of a configuration of a card according to Modification 1 of Application Example 2.

[0052] Fig.11 is a cross-sectional view showing an example of a configuration of a card according to Modification 2 of Application Example 2.

[0053] Fig.12 is a cross-sectional view showing an example of a configuration of a card according to Modification 3 of Application Example 2.

[0054] Fig.13 is a cross-sectional view showing an example of the appearance of a booklet according to Application Example 3.

[0055] Fig.14A is a plan view showing an example of the external appearance on the front side of a smartphone according to Application Example 4. FIG. Fig.14 B is a plan view showing an example of the appearance on the back surface of the smartphone according to Application Example 4.

[0056] Fig.15 is a cross-sectional view showing an example of the appearance of a notebook personal computer according to Application Example 5.

[0057] Fig.16 : is a cross-sectional view showing an example of the appearance of a cosmetic container according to Application Example 6.

[0058] Fig.17 is a graph showing the relationship between the content of the polycarbonate resin and the average peel strength. DETAILED DESCRIPTION

[0059] The embodiments of the present disclosure will be described in the following order with reference to the drawings. In addition, in all the drawings of the following embodiments, the same reference numerals are given to the same or corresponding parts.

[0060] 1 First Embodiment (Example of Recording Medium)

[0061] 2 Second Embodiment (Example of Recording Medium)

[0062] 3 Application Examples

[0063] 3-1 Application Example 1 (Card Implementation)

[0064] 3-2 Application Example 2 (Card Implementation)

[0065] 3-3 Application Example 3 (Implementation Example in Booklet)

[0066] 3-4 Application Example 4 (Smart Phone Implementation)

[0067] 3-5 Application Example 5 (Notebook PC)

[0068] 3-6 Application Example 6 (Example of Cosmetic Container)

[0069] 4. Embodiment

[0070] <1 First Embodiment>

[0071] [Configuration of recording medium]

[0072] Figure 11 is a cross-sectional view showing an example of the configuration of the recording medium 10 according to the first embodiment. The recording medium 10 includes, in order, a substrate 11, a pressure-sensitive adhesive layer 12A, a recording layer 13A, an intermediate layer 14A, a recording layer 13B, an intermediate layer 14B, a recording layer 13C, an intermediate layer 14C, an ultraviolet cutting layer (hereinafter, referred to as "UV cutting layer") 15, a pressure-sensitive adhesive layer 12B, and a cover layer 16. Note that the substrate 11, the pressure-sensitive adhesive layer 12A, the intermediate layer 14C, the UV cutting layer 15, the pressure-sensitive adhesive layer 12B, and the cover layer 16 are provided as needed.

[0073] (Substrate 11)

[0074] The substrate 11 may be a supporting substrate for supporting each layer provided on the substrate 11. The substrate 11 preferably contains a material having excellent heat resistance and excellent dimensional stability in a plane direction. The substrate 11 may have a transmissive property or a non-transmissive property with respect to visible light. In this specification, visible light refers to light within a wavelength range of 360 nm or more and 780 nm or less. The substrate 11 may have a predetermined color such as white. The substrate 11 has, for example, a plate shape or a film shape. Note that in this disclosure, a film is defined as including a sheet.

[0075] The substrate 11 may have, for example, rigidity or flexibility. In the case where the substrate 11 has flexibility, a flexible recording medium 10 may be realized. Examples of the substrate 11 having rigidity include a wafer, a glass substrate, etc. Examples of the substrate 11 having flexibility include flexible glass, a film, paper, etc.

[0076] For example, the substrate 11 includes at least one selected from the group consisting of an inorganic material, a metal material, a polymer material, etc. The inorganic material includes, for example, silicon (Si), silicon oxide (SiO X ), Silicon Nitride (SiN X ), aluminum oxide (AlO X ) and the like. The silicon oxide includes, for example, at least one selected from the group including glass, spin-on glass (SOG), and the like. The metal material includes, for example, at least one selected from the group including aluminum (Al), nickel (Ni), stainless steel, and the like. For example, the polymer material includes at least one selected from the group including polycarbonate (PC) resin, polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, polyetheretherketone (PEEK) resin, polyvinyl chloride (PVC) resin, and the like.

[0077] Note that a reflective layer (not shown) may be provided on at least one of the first surface or the second surface of the substrate 11, or the substrate 11 itself may also function as the reflective layer. The substrate 11 having such a configuration enables clearer color display.

[0078] (Recording layers 13A, 13B, 13C)

[0079] The recording layers 13A, 13B and 13C are configured to be able to change the coloring state by external excitation. The external excitation is, for example, a laser. The recording layers 13A, 13B and 13C in the recording state are in a color development state, and the recording layers 13A, 13B and 13C in the non-recording state are in a non-color state. The recording layers 13A, 13B and 13C can be changed from a non-color state to a color development state by external excitation. The non-coloring state can be a state in which laser and visible light can be transmitted. The change of the coloring state can be a reversible change or an irreversible change. From the viewpoint of improving anti-counterfeiting, the change of the coloring state is preferably an irreversible change. That is, from the viewpoint of improving anti-counterfeiting, the recording medium 10 is preferably a one-time write type that allows only writing of a pattern once, etc.

[0080] The recording layers 13A, 13B, and 13C can respectively display different tones from each other in the color development state. Specifically, the recording layer 13A can present magenta in the color development state. The recording layer 13B can present cyan in the color development state. The recording layer 13C can present yellow in the color development state. Magenta, cyan, and yellow are embodiments of the first primary color, the second primary color, and the third primary color, respectively. The first primary color, the second primary color, and the third primary color can be colors of the three primary colors. The first primary color, the second primary color, and the third primary color can be colors other than magenta, cyan, and yellow. The laser that can change the recording layer 13A into the color development state, the laser that can change the recording layer 13B into the color development state, and the laser that can change the recording layer 13C into the color development state have peak wavelengths that are different from each other.

[0081] The thickness of the recording layers 13A, 13B, and 13C is preferably 1 μm or more and 20 μm or less, and more preferably 2 μm or more and 15 μm or less. With the recording layers 13A, 13B, and 13C having a thickness of 1 μm or more, the color density can be improved. However, with the recording layers 13A, 13B, and 13C having a thickness of 20 μm or less, the heat utilization of the recording layers 13A, 13B, and 13C can be prevented from increasing, and the deterioration of the color development can be prevented.

[0082] The recording layer 13A is configured to be able to perform recording with a first laser having a first peak wavelength λ1. The recording layer 13A contains a first coloring compound having an electron donating property, a first developer having an electron accepting property, and a first photothermal conversion agent. The recording layer 13A preferably further contains a first matrix resin.

[0083] The recording layer 13B is configured to be able to perform recording using a second laser having a second peak wavelength λ2. The recording layer 13B contains a second coloring compound having an electron donating property, a second developer having an electron accepting property, and a second photothermal conversion agent. The recording layer 13B preferably further contains a second matrix resin.

[0084] The recording layer 13C is configured to be able to perform recording using a third laser having a third peak wavelength λ3. The recording layer 13C contains a third coloring compound having an electron donating property, a third developer having an electron accepting property, and a third photothermal conversion agent. The recording layer 13C preferably further contains a third matrix resin.

[0085] The first laser, the second laser and the third laser are preferably near-infrared lasers. The first peak wavelength λ1, the second peak wavelength λ2 and the third peak wavelength λ3 are preferably included in the near-infrared range. The upper limit values ​​of the first peak wavelength λ1, the second peak wavelength λ2 and the third peak wavelength λ3 are, for example, below 2000nm. The lower limit values ​​of the first peak wavelength λ1, the second peak wavelength λ2 and the third peak wavelength λ3 are, for example, above 700nm.

[0086] The first peak wavelength λ1, the second peak wavelength λ2 and the third peak wavelength λ3 are different from each other. Therefore, recording can be performed independently on the recording layer 13A, the recording layer 13B and the recording layer 13C. The first peak wavelength λ1, the second peak wavelength λ2 and the third peak wavelength λ3 preferably satisfy λ3<λ2<λ1.

[0087] (First, second and third coloring compounds)

[0088] The first, second and third coloring compounds can be colored by reacting with the first, second and third developers, respectively. The first, second and third coloring compounds can display different tones from each other in the coloring state. Specifically, the first coloring compound can show magenta in the coloring state. The second coloring compound can show cyan in the coloring state. The third coloring compound can show yellow in the coloring state.

[0089] The first, second and third coloring compounds are, for example, leuco dyes. When the lactone ring in the molecule reacts with an acid to open the ring, the leuco dye develops color. When the open lactone ring reacts with an alkali to close the ring, the leuco dye can be decolorized. The leuco dye can be, for example, an existing dye for thermal paper.

[0090] The first, second and third coloring compounds can be appropriately selected according to the purpose without any limitation. The first coloring compound, the second coloring compound and the third coloring compound include, for example, at least one selected from the group including fluoran compounds, triphenylmethanephthalide compounds, azaphthalide compounds, phenothiazine compounds, colorless gold amine compounds, indolinophthalide compounds, etc. In addition, the first, second and third coloring compounds may contain, for example, at least one selected from the group consisting of 2-anilino-3-methyl-6-diethylaminofluorescein, 2-anilino-3-methyl-6-di(n-butylamino)fluoran, 2-anilino-3-methyl-6-(N-n-propyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-isopropyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-isobutyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-n-pentyl-N-methylamino)fluoran, ) fluoran, 2-anilino-3-methyl-6-(N-sec-butyl-N-methylamino) fluoran, 2-anilino-3-methyl-6-(N-n-pentyl-N-ethylamino) fluoran, 2-anilino-3-methyl-6-(N-isopentyl-N-ethylamino) fluoran, 2-anilino-3-methyl-6-(N-n-propyl-N-isopropylamino) fluoran, 2-anilino-3-methyl-6-(N-cyclohexyl-N-methylamino) fluoran, 2-anilino-3-methyl-6-(N-ethyl-p-tolylamino) fluoran, 2-anilino-3-methyl Methyl-6-(N-methyl-p-toluinyl)fluorocarbon, 2-(m-trichloromethylanilino)-3-methyl-6-diethylaminofluorocarbon, 2-(m-trifluoromethylanilino)-3-methyl-6-diethylaminofluorocarbon, 2-(m-trichloromethylanilino)-3-methyl-6-(N-cyclohexyl-N-methylamino)fluorocarbon, 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluorocarbon, 2-(N-ethyl-p-toluinyl)-3-methyl-6-(N-ethylanilino)fluorocarbon, 2-(N-ethyl-p-toluinyl)-3-methyl-6-(N-ethylanilino)fluorocarbon, 2-(2-chlorophenylamino)-6-diethylaminofluorane, 2-(2-chlorophenylamino)-6-diethylaminofluorane, 2-(2-chlorophenylamino)-6-dibutylaminofluorane, 2-(m-trifluoromethylanilino)-6-diethylaminofluorane, 2,3-dimethyl-6-dimethylaminofluorane, 3-methyl-6-(N-ethyl-2-chlorophenylamino)fluorane, 2-chloro-6-diethylaminofluorane, 2-bromo-6-diethylaminofluorane, 2-chloro-6-dipropylaminofluorane,3-Chloro-6-cyclohexylaminofluorocarbon, 3-bromo-6-cyclohexylaminofluorocarbon, 2-chloro-6-(N-ethyl-N-isopentylamino)fluorocarbon, 2-chloro-3-methyl-6-diethylaminofluorocarbon, 2-anilino-3-chloro-6-diethylaminofluorocarbon, 2-(o-chloroanilino)-3-chloro-6-cyclohexylaminofluorocarbon, 2-(m-trifluoromethylanilino)-3-chloro-6-diethylaminofluorane, 2-(2,3-dichloroanilino)-3-chloro-6-diethylaminofluorane, 1,2-benzo-6-diethylaminofluorane, 3-diethylamino-6-(m-trifluoromethylanilino)fluorane, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylamino)fluorane phthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-7-phthalide, 3-(1-octyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-4-phthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-methyl-4-diethylaminophenyl)-4-phthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-methyl-4-diethylaminophenyl)-4-phthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-methyl-4-diethylaminophenyl)-7-phthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(4-diethylaminophenyl)-4-phthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(4-diethylaminophenyl)-4-phthalide, phthalide, 3-(1-methyl-2-methylindol-3-yl)-3-(4-N-n-pentyl-N-methylaminophenyl)-4-phthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-phthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-7-phthalide, 2-(p-acetylamino)-6-(N-n-pentyl-N-n-butylamino)fluorocarbon, 2-benzylamino-6-(N-ethyl-p-toluidinyl)fluorocarbon, 2-benzylamino-6-(N-methyl-2,4-dimethylanilino)fluorocarbon, 2-benzylamino-6-(N-ethyl-2,4-dimethylphenylamino)fluorocarbon fluorocarbon, 2-benzylamino-6-(N-methyl-p-tolylamino)fluorocarbon, 2-benzylamino-6-(N-ethyl-p-tolylamino)fluorocarbon, 2-(di-p-methylphenylamino)-6-(N-ethyl-p-tolylamino)fluorocarbon, 2-(α-phenylethylamino)-6-(N-ethyl-p-tolylamino)fluorocarbon, 2-methylamino-6-(N-methylanilino)fluorocarbon, 2-methylamino-6-(N-ethylanilino)fluorocarbon, 2-methylamino-6-(N-propylanilino)fluorocarbon, 2-ethylamino-6-(N-methyl-p-tolylino)fluorocarbon, 2-methylamino-6-(N-methyl-2,4-dimethylanilino)fluorocarbon, 2-ethylamino-6-(N-ethyl-2,4-Dimethylanilino)fluorocarbon, 2-dimethylamino-6-(N-methylanilino)fluorocarbon, 2-dimethylamino-6-(N-ethylanilino)fluorocarbon, 2-diethylamino-6-(N-methyl-p-toluidinyl)fluorocarbon, 2-diethylamino-6-(N-ethyl-p-toluidinyl)fluorocarbon, 2-dipropylamino-6-(N-methylanilino)fluorocarbon, 2-dipropylamino-6-(N-ethyl 2-amino-6-(N-methylanilino)fluoride, 2-amino-6-(N-ethylamino)fluoride, 2-amino-6-(N-propylamino)fluoride, 2-amino-6-(N-methyl-p-toluinyl)fluoride, 2-amino-6-(N-ethyl-p-toluinyl)fluoride, 2-amino-6-(N-propyl-p-toluinyl)fluoride, 2-amino-6-(N-methyl-p-toluinyl)fluoride fluorane, 2-amino-6-(N-ethyl-p-ethylaniline)fluorane, 2-amino-6-(N-propyl-p-ethylaniline)fluorane, 2-amino-6-(N-methyl-2,4-dimethylaniline)fluorane, 2-amino-6-(N-ethyl-2,4-dimethylaniline)fluorane, 2-amino-6-(N-propyl-2,4-dimethylaniline)fluorane, 2-amino-6-(N-methyl-p-chloroaniline)fluorane Fluorane, 2-amino-6-(N-ethyl-p-chloroanilino)fluoran, 2-amino-6-(N-propyl-p-chloroanilino)fluoran, 1,2-benzo-6-(N-ethyl-N-isopentylamino)fluoran, 1,2-benzo-6-dibutylaminofluoran, 1,2-benzo-6-(N-methyl-N-cyclohexylamino)fluoran, 1,2-benzo-6-(N-ethyl-N-toluinylamino)fluoran, and the like.

[0091] (First, second and third developers)

[0092] The first, second and third developers can make the first, second and third coloring compounds in a non-colored state develop colors respectively. The types of the first developer, the second developer and the third developer can be the same or different from each other. The first developer, the second developer and the third developer are compounds containing electron accepting groups in the molecules. The electron accepting part of the first, second and third developers reacts with the lactone ring of the first, second and third coloring compounds respectively, and the lactone ring opens, thereby the first, second and third coloring compounds develop colors. For example, the first, second and third developers contain at least one selected from the group including phenol derivatives, salicylic acid derivatives, urea derivatives, etc.

[0093] Specifically, for example, the developer contains a compound represented by the following formula (1):

[0094] [Chemical formula 1]

[0095]

[0096] (Wherein, in formula (1), X 0 is a divalent group including at least one benzene ring; 01 and Y 02 Each is independently a monovalent group; n01 and n02 are each independently any integer from 0 to 5; when n01 is any integer from 2 to 5, Y 01 can be the same as or different from each other; when n02 is any integer from 2 to 5, Y 02 may be the same as or different from each other; and Z 01 and Z 02 are each independently a hydrogen bonding group).

[0097] In X 0 In the case of including at least one benzene ring, 0 Compared with the case where X is an aliphatic hydrocarbon group (e.g., a normal alkyl chain), the melting point can be increased, so that the color retention property during high temperature and high humidity storage (hereinafter, referred to as "high temperature and high humidity storage property") can be improved. From the viewpoint of improving high temperature and high humidity storage property and heat resistance, X 0 It is preferred to include at least two benzene rings. The high temperature and high humidity storage characteristics are, for example, storage characteristics under an environment of 80°C and 60% RH. The increase in heat resistance leads to an improvement in the resistance of the recording medium 10 to severe processes (e.g., hot pressing, integral molding using molten resin, etc.). 0 In the case of including at least two benzene rings, the at least two benzene rings may be fused. For example, naphthalene or anthracene may be used.

[0098] In Z 01 and Z 02 In the case where each is independently a hydrogen bonding group, the developer may be present while aggregating to some extent via hydrogen bonding, thereby improving the stability of the developer in the recording layers 13A, 13B, and 13C. In the present specification, a hydrogen bonding group refers to a functional group including an atom capable of hydrogen bonding with an atom present in another functional group, another compound, or the like.

[0099] The developer preferably contains a compound represented by the following formula (2):

[0100] [Chemical formula 2]

[0101]

[0102] (Wherein, in formula (2), X 1 is a divalent group including at least one benzene ring; 11 , Y 12 , Y 13 and Y 14 are each independently a monovalent group; and Z11 and Z 12 are each independently a hydrogen bonding group).

[0103] In X 1 In the case of including at least one benzene ring, 1 Compared with the case where X is an aliphatic hydrocarbon group (e.g., a normal alkyl chain), the melting point can be increased, so that the high temperature and high humidity storage characteristics can be improved. From the viewpoint of improving the high temperature and high humidity storage characteristics and heat resistance, X 1 Preferably, it comprises at least two benzene rings. 1 In the case of including at least two benzene rings, the at least two benzene rings may be fused. For example, naphthalene or anthracene may be used.

[0104] In Z 11 and Z 12 In the case of each independently being a hydrogen bonding group, the developer may exist while aggregating to some extent via hydrogen bonding, so that the stability of the developer in the recording layers 13A, 13B, and 13C is improved.

[0105] In the case where formula (1) and formula (2) include a hydrocarbon group, the hydrocarbon group is a general term for a group including carbon (C) and hydrogen (H), and may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. A saturated hydrocarbon group is an aliphatic hydrocarbon group having no carbon-carbon multiple bonds, and an unsaturated hydrocarbon group is an aliphatic hydrocarbon group having a carbon-carbon multiple bond (a carbon-carbon double bond or a carbon-carbon triple bond).

[0106] In the case where formula (1) and formula (2) include a hydrocarbon group, the hydrocarbon group may be a chain or may include one or more rings. The chain may be a straight chain or may be a branched chain having one or more side chains.

[0107] (X 0 , X 1 With a benzene ring)

[0108] X in formula (1) 0 and X in formula (2) 1 is, for example, a divalent group containing one benzene ring. The divalent group is represented by, for example, the following formula (3):

[0109] [Chemical formula 3]

[0110]

[0111] (Wherein, in formula (3), X 21 Can be present or absent, and in X 21 In the presence of X 21 is a divalent group; X 22 Can be present or absent, and in X 22 In the presence of X22 is a divalent group; R 21 is a monovalent group; n21 is any integer from 0 to 4; in the case where n21 is any integer from 2 to 4, R 21 may be the same as or different from each other; and * represents a bonding portion).

[0112] In formula (3), X 21 and X 22 The bonding position on the benzene ring is not restricted. 21 and X 22 The bonding position of can be any of the ortho, meta and para positions.

[0113] From the viewpoint of improving high-temperature and high-humidity storage characteristics, the above-mentioned divalent group containing one benzene ring is preferably represented by the following formula (4):

[0114] [Chemical formula 4]

[0115]

[0116] (Wherein, in the formula (4), R 22 is a monovalent group; n22 is any integer from 0 to 4; in the case where n22 is any integer from 2 to 4, R 22 may be the same as or different from each other; and * represents a bonding portion).

[0117] In formula (1), X 0 In the case of a divalent group including one benzene ring, Z on the benzene ring in formula (4) 01 and Z 02 The bonding position of Z is not restricted. 01 and Z 02 The bonding position of may be any of the ortho, meta and para positions.

[0118] In formula (2), X 1 In the case of a divalent group including one benzene ring, Z on the benzene ring in formula (4) 11 and Z 12 The bonding position of Z is not restricted. 11 and Z 12 The bonding position on the benzene ring may be any of the ortho, meta and para positions.

[0119] (X 21 , X 22 )

[0120] X in formula (3) 21 and X 22It is only necessary that each independently is a divalent group without limitation, and its embodiment includes a hydrocarbon group optionally having a substituent. The hydrocarbon group is preferably in a chain form. Through the chain hydrocarbon group, the melting point of the developer can be reduced, so that the developer can be dissolved by laser irradiation, and thus the coloring compound is easy to develop color. From the viewpoint of reducing the melting point of the developer, a normal alkyl chain is particularly preferred in the chain hydrocarbon group.

[0121] The number of carbon atoms of the hydrocarbon group which may have a substituent is, for example, 1 to 15, 1 to 13, 1 to 12, 1 to 10, 1 to 6, or 1 to 3.

[0122] In formula (3), X 21 and X 22 In the case of a normal alkyl group, from the viewpoint of high temperature storage stability, the number of carbon atoms of the normal alkyl group is preferably 8 or less, more preferably 6 or less, more preferably 5 or less, and particularly preferably 3 or less. It is believed that in the case where the number of carbon atoms of the normal alkyl group is 8 or less, due to the short length of the normal alkyl group, thermal disturbance is less likely to occur in the developer during storage at high temperatures, and the site that interacts with a coloring compound such as a leuco dye is less likely to be separated during color development. Therefore, during high temperature storage, a coloring compound such as a leuco dye is less likely to decolorize, thereby improving high temperature storage stability.

[0123] Examples of the substituent that the hydrocarbon group may optionally have include a halogen group (e.g., a fluoro group), an alkyl group having a halogen group (e.g., a fluoro group), etc. The hydrocarbon group optionally having a substituent may be a hydrocarbon group obtained by substituting a part of the carbon atoms of the hydrocarbon group (e.g., a part of the carbon atoms included in the main chain of the hydrocarbon group) with an element such as oxygen.

[0124] (R 21 )

[0125] R in formula (3) 21 It only needs to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent.

[0126] The halogen group is, for example, fluoro (—F), chloro (—Cl), bromo (—Br) or iodo (—I).

[0127] The number of carbon atoms of the hydrocarbon group which may have a substituent is, for example, 1 to 15, 1 to 13, 1 to 12, 1 to 10, 1 to 6, or 1 to 3.

[0128] Examples of the substituent that the hydrocarbon group may optionally have include a halogen group (e.g., a fluoro group), an alkyl group having a halogen group (e.g., a fluoro group), etc. The hydrocarbon group optionally having a substituent may be a hydrocarbon group obtained by substituting a part of the carbon atoms of the hydrocarbon group (e.g., a part of the carbon atoms included in the main chain of the hydrocarbon group) with an element such as oxygen.

[0129] (R 22 )

[0130] R in formula (4) 22 It only needs to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent. The halogen group and the hydrocarbon group optionally having a substituent are similar to R in the above formula (3). 21 substituent.

[0131] (X 0 , X 1 Contains two benzene rings)

[0132] X in formula (1) 0 and X in formula (2) 1 is, for example, a divalent group including two benzene rings. The divalent group is represented by, for example, the following formula (5):

[0133] [Chemical formula 5]

[0134]

[0135] (Wherein, in formula (5), X 31 Can be present or absent, and in X 31 In the presence of X 31 is a divalent group; X 32 Can be present or absent, and in X 32 In the presence of X 32 is a divalent group; X 33 Can be present or absent, and in X 33 In the presence of X 33 is a divalent group; R 31 and R 32 Each is independently a monovalent group; n31 and n32 are each independently any integer from 0 to 4; in the case where n31 is any integer from 2 to 4, R 31 can be the same as or different from each other; when n32 is any integer from 2 to 4, R 32 may be the same as or different from each other; and * represents a bonding portion).

[0136] In formula (5), X 31 and X 32 The bonding position on the benzene ring is not restricted. 31 and X32 The bonding position on the benzene ring can be any one of the ortho, meta and para positions. Similarly, in formula (5), X 32 and X 33 The bonding position on the benzene ring is not restricted. 32 and X 33 The bonding position on the benzene ring may be any of the ortho, meta and para positions.

[0137] From the viewpoint of improving high temperature and high humidity storage characteristics, the above-mentioned divalent group containing two benzene rings is preferably represented by the following formula (6):

[0138] [Chemical formula 6]

[0139]

[0140] (Wherein, in formula (6), X 34 is a divalent group; R 33 and R 34 Each is independently a monovalent group; n33 and n34 are each independently any integer from 0 to 4; when n33 is any integer from 2 to 4, R 33 can be the same as or different from each other; when n34 is any integer from 2 to 4, R 34 may be the same as or different from each other; and * represents a bonding portion).

[0141] In formula (1), X 0 In the case of a divalent group including two benzene rings, Z on the benzene ring in formula (6) 01 and X 34 The bonding position of Z is not restricted. 01 and X 34 The bonding position of Z can be any one of the ortho, meta and para positions. Similarly, in formula (6), Z 02 and X 34 The bonding position on the benzene ring is not restricted. 02 and X 34 The bonding position of can be any of the ortho, meta and para positions.

[0142] In formula (2), X 1 In the case of a divalent group including two benzene rings, Z on the benzene ring in formula (6) 11 and X 34 The bonding position of Z is not restricted. 11 and X 34 The bonding position on the benzene ring can be any one of the ortho, meta and para positions. Similarly, in formula (6), Z 12 and X 34The bonding position on the benzene ring is not restricted. 12 and X 34 The bonding position on the benzene ring may be any of the ortho, meta and para positions.

[0143] (X 31 , X 32 , X 33 )

[0144] X in formula (5) 31 , X 32 and X 33 It is only necessary that each is independently a divalent group without limitation, and examples thereof include a hydrocarbon group optionally having a substituent. The hydrocarbon group is similar to X in the above formula (3). 21 and X 22 of hydrocarbon groups.

[0145] (X 34 )

[0146] X in formula (6) 34 It only needs to be a divalent group without limitation, and examples thereof include a hydrocarbon group optionally having a substituent. The hydrocarbon group is similar to X in the above formula (3). 21 and X 22 of hydrocarbon groups.

[0147] (R 31 , R 32 )

[0148] R in formula (5) 31 and R 32 It only needs to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent. The halogen group and the hydrocarbon group optionally having a substituent are similar to R in the above formula (3). 21 substituent.

[0149] (R 33 , R 34 )

[0150] R in formula (6) 33 and R 34 It only needs to be a monovalent group without limitation, and examples thereof include a halogen group or a hydrocarbon group optionally having a substituent. The halogen group and the hydrocarbon group optionally having a substituent are similar to R in the above formula (3). 21 substituent.

[0151] (Y 01 , Y 02 )

[0152] Y in formula (1) 01 and Y 02Each is independently, for example, a hydrogen group (—H), a hydroxyl group (—OH), a halogen group (—X), a carboxyl group (—COOH), an ester group (—COOR), or a hydrocarbon group which may have a substituent.

[0153] The halogen group is, for example, fluoro (—F), chloro (—Cl), bromo (—Br) or iodo (—I).

[0154] The number of carbon atoms of the hydrocarbon group which may have a substituent is, for example, 1 to 15, 1 to 13, 1 to 12, 1 to 10, 1 to 6, or 1 to 3.

[0155] Examples of the substituent that the hydrocarbon group may optionally have include a halogen group (e.g., a fluoro group), an alkyl group having a halogen group (e.g., a fluoro group), etc. The hydrocarbon group optionally having a substituent may be a hydrocarbon group obtained by substituting a part of the carbon atoms of the hydrocarbon group (e.g., a part of the carbon atoms included in the main chain of the hydrocarbon group) with an element such as oxygen.

[0156] In formula (1), preferably, (Y 01 ) n01 One and / or (Y 02 ) n02 One of them is hydroxyl group (-OH). 01 ) n01 One of and / or (Y 02 ) n02 When one of the groups is a hydroxyl group (-OH), display quality and light resistance can be improved.

[0157] (Y 11 , Y 12 , Y 13 , Y 14 )

[0158] In formula (2), Y 11 and Y 12 The bonding position on the benzene ring is not limited. 11 and Y 12 The bonding position on the benzene ring can be any one of the ortho, meta and para positions. Similarly, in formula (2), Y 13 and Y 14 The bonding position on the benzene ring is also not restricted. 13 and Y 14 The bonding position of can be any one of the ortho, meta and para positions. In formula (2), Y 11 and Y 12 The bonding position on a benzene and Y 13 and Y 14 The bonding position on the other benzene may be the same or different.

[0159] Y in formula (2) 11 , Y 12 , Y 13 and Y 14 Each independently represents, for example, a hydrogen group (-H), a hydroxyl group (-OH), a halogen group, a carboxyl group (-COOH), an ester group (-COOR) or a hydrocarbon group optionally having a substituent. Each of the halogen group and the hydrocarbon group optionally having a substituent is similar to Y in the above formula (1). 01 and Y 02 of halogen groups and hydrocarbon groups.

[0160] In formula (2), Y 11 and / or Y 13 Preferably it is hydroxyl group (-OH). 11 and / or Y 13 In the case of a hydroxyl group (-OH), display quality and light resistance can be improved.

[0161] (Z 01 , Z 02 )

[0162] Z in formula (1) 01 and Z 02 Each independently is, for example, a urea bond (-NHCONH-), an amide bond (-NHCO-, -OCHN-) or a hydrazide bond (-NHCOCONH-). From the viewpoint of improving high temperature and high humidity storage characteristics, Z 01 and Z 02 Preferably, it is a urea bond. 01 In the case of an amide bond, the nitrogen included in the amide bond may be bonded to benzene, or the carbon included in the amide bond may be bonded to benzene. 02 In the case of an amide bond, nitrogen included in the amide bond may be bonded to benzene, or carbon included in the amide bond may be bonded to benzene.

[0163] (Z 11 , Z 12 )

[0164] Z in formula (2) 11 and Z 12 Each independently is, for example, a urea bond (-NHCONH-), an amide bond (-NHCO-, -OCHN-) or a hydrazide bond (-NHCOCONH-). From the viewpoint of improving high temperature and high humidity storage characteristics, Z 11 and Z 12 Preferably, it is a urea bond. 11 In the case of an amide bond, the nitrogen included in the amide bond may be bonded to benzene, or the carbon included in the amide bond may be bonded to benzene. 12In the case of an amide bond, nitrogen included in the amide bond may be bonded to benzene, or carbon included in the amide bond may be bonded to benzene.

[0165] (Specific Examples of Developer)

[0166] Specifically, X in formula (1) 0 and X in formula (2) 1 The developer including one benzene ring contains, for example, at least one selected from the group of compounds represented by the following formulae (7-1) to (7-6).

[0167] [Chemical formula 7]

[0168]

[0169] Specifically, X in formula (1) 0 and X in formula (2) 1 The developer including two benzene rings contains, for example, at least one selected from the group of compounds represented by the following formulae (8-1) to (8-8).

[0170] [Chemical formula 8]

[0171]

[0172] (First, second and third photothermal conversion agents)

[0173] The first, second and third photothermal conversion agents can generate heat by absorbing light in a predetermined wavelength region (such as a near-infrared region). The first, second and third photothermal conversion agents have different absorption wavelength peaks from each other. Specifically, the first photothermal conversion agent is capable of absorbing a first laser having a first peak wavelength λ1 to generate heat. The absorption wavelength peak of the first photothermal conversion agent may be substantially equal to the above-mentioned first peak wavelength λ1. The second photothermal conversion agent may absorb a second laser having a second peak wavelength λ2 to generate heat. The absorption wavelength peak of the second photothermal conversion agent may be substantially equal to the above-mentioned second peak wavelength λ2. The third photothermal conversion agent may absorb a third laser having a third peak wavelength λ3 to generate heat. The absorption wavelength peak of the third photothermal conversion agent may be substantially equal to the above-mentioned third peak wavelength λ3. Wavelengths λ1, λ2 and λ3 are different from each other. The absorption wavelength peak is preferably in the near-infrared region. The near-infrared region is, for example, in a wavelength range of 700nm or more and 2000nm or less. As described above, since the first photothermal converter, the second photothermal converter, and the third photothermal converter have absorption wavelength peaks different from each other, a desired layer among the recording layers 13A, 13B, and 13C can be selectively colored by irradiating with laser light. A near-infrared absorbing dye having almost no absorption in the visible light region is preferably used as the first, second, and third photothermal converters.

[0174] For example, the first, second and third photothermal conversion agents include at least one selected from the group consisting of compounds having a cyanine skeleton (cyanine dye), compounds having a phthalocyanine skeleton (phthalocyanine dye), compounds having a squarylium skeleton (squarylium dye), inorganic compounds, etc. The inorganic compound includes, for example, at least one selected from the group consisting of metal complexes such as disulfide complexes, diimmonium salts, ammonium salts, graphite, carbon black, metal powder particles, metal oxides such as cobalt tetraoxide, iron oxide, chromium oxide, copper oxide, titanium black, and indium tin oxide (ITO), metal nitrides such as niobium nitride, metal carbides such as tantalum carbide, metal sulfides, various magnetic powders, etc.

[0175] The first, second and third photothermal conversion agents preferably have excellent light resistance and heat resistance. In addition, the excellent light resistance mentioned here means that it will not decompose due to light irradiation of fluorescent lamps, etc. under the use environment. Excellent heat resistance means that, for example, the film formed together with the polymer material does not change by 20% or more in the maximum absorption peak of the absorption spectrum after being stored at 150°C for 30 minutes. An embodiment of a compound having a cyanine skeleton having the above-mentioned characteristics includes a compound having at least one of a counter ion of any one of SbF6, PF6, BF4, ClO4, CF3SO3 or (CF3SO3)2N or a 5-membered ring or a 6-membered ring of a second methyl chain in the molecule. Note that although the compound having a cyanine skeleton used for the recording medium 10 in the first embodiment preferably has any one of the above counter ions and a cyclic structure such as a 5-membered ring and a 6-membered ring in the second methyl chain, as long as the compound has at least one of the counter ions or the cyclic structure, sufficient light resistance and heat resistance are ensured.

[0176] (First, second and third matrix resins)

[0177] The first, second and third matrix resins preferably have the function of an adhesive. The first matrix resin is preferably a resin in which the first coloring compound, the first developer and the first photothermal conversion agent may be uniformly dispersed. The second matrix resin is preferably a resin in which the second coloring compound, the second developer and the second photothermal conversion agent may be uniformly dispersed. The third matrix resin is preferably a resin in which the third coloring compound, the third developer and the third photothermal conversion agent may be uniformly dispersed. The types of the first, second and third matrix resins may be the same or different from each other.

[0178] The first, second and third matrix resins include polycarbonate resins (first polycarbonate resins). By using the first, second and third matrix resins including polycarbonate resins, the light resistance of the background of the recording medium 10 can be improved. Here, the polycarbonate resin is a resin having a carbonate group (-O-(C=O)-O-) as a structural unit at least in the main chain. Therefore, in addition to the carbonate group, other structural units may be included in the main chain.

[0179] The first, second and third matrix resins may further include a thermoplastic resin different from the polycarbonate resin. The first, second and third matrix resins may further include a thermosetting resin and a thermoplastic resin. More specifically, for example, the first matrix resin, the second matrix resin and the third matrix resin together with the polycarbonate resin include at least one selected from the group consisting of polyvinyl chloride resin, polyvinyl acetate resin; vinyl chloride-vinyl acetate copolymer resin, ethyl cellulose resin, polystyrene resin, styrene copolymer resin, phenoxy resin resin, polyester resin, aromatic polyester resin, polyurethane resin, polyacrylate resin, polymethacrylate resin, acrylic copolymer resin, maleic acid polymer resin, polyvinyl alcohol resin, modified polyvinyl alcohol resin, hydroxyethyl cellulose resin, carboxymethyl cellulose resin starch, etc.

[0180] (additive)

[0181] If necessary, the recording layers 13A, 13B, and 13C may further contain at least one additive selected from the group consisting of a sensitizer, an ultraviolet absorber, etc. From the viewpoint of preventing background coloring, the recording layers 13A, 13B, and 13C preferably contain an amine compound.

[0182] In the case where the recording layers 13A, 13B, and 13C contain an amine compound, it is preferred that the recording layers 13A, 13B, and 13C contain at least one compound selected from the group consisting of epoxy compounds and carbodiimide compounds and the amine compound. In the case where the recording layers 13A, 13B, and 13C contain an amine compound, there is a possibility that the reliability of the color developing portion during high temperature and high humidity storage deteriorates. However, in the case where the recording layers 13A, 13B, and 13C contain at least one compound selected from the group consisting of epoxy compounds and carbodiimide compounds and the amine compound, the deterioration of the reliability of the color developing portion due to the amine compound during high temperature and high humidity storage can be prevented.

[0183] (Pressure-sensitive adhesive layers 12A, 12B)

[0184] The pressure-sensitive adhesive layer 12A is provided between the substrate 11 and the recording layer 13A. The pressure-sensitive adhesive layer 12A bonds the substrate 11 and the recording layer 13A together. The pressure-sensitive adhesive layer 12A may be transmissive or non-transmissive with respect to laser light and visible light used for drawing on the recording medium 10.

[0185] The pressure-sensitive adhesive layer 12B is provided between the UV cutting layer 15 and the cover layer 16. The pressure-sensitive adhesive layer 12B bonds the UV cutting layer 15 and the cover layer 16 together. The pressure-sensitive adhesive layer 12A is preferably transmissive to laser light and visible light used for drawing on the recording medium 10.

[0186] The pressure-sensitive adhesive layers 12A and 12B are, for example, double-sided adhesive films such as optically clear adhesive (OCA).

[0187] (Middle Layers 14A, 14B, 14C)

[0188] The intermediate layer 14A is provided between the recording layer 13A and the recording layer 13B. The intermediate layer 14A may suppress diffusion of constituent materials between the recording layer 13A and the recording layer 13B. The intermediate layer 14A may be able to insulate heat between the recording layer 13A and the recording layer 13B.

[0189] The intermediate layer 14B is provided between the recording layer 13B and the recording layer 13C. The intermediate layer 14B can suppress diffusion of constituent materials between the recording layer 13B and the recording layer 13C. The intermediate layer 14B can insulate heat between the recording layer 13B and the recording layer 13C.

[0190] The intermediate layer 14C is provided between the recording layer 13C and the UV cutting layer 15. The intermediate layer 14C can suppress diffusion of constituent materials between the recording layer 13C and the UV cutting layer 15. The intermediate layer 14C can insulate heat between the recording layer 13C and the UV cutting layer 15.

[0191] The intermediate layers 14A, 14B, and 14C are preferably transmissive to laser light and visible light used for drawing on the recording medium 10 .

[0192] The thickness of the intermediate layers 14A, 14B and 14C is preferably 3 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less. With the intermediate layers 14A, 14B and 14C having a thickness of 3 μm or more, a sufficient diffusion suppression effect can be obtained, and a sufficient heat insulation effect can be obtained. However, with the intermediate layers 14A, 14B and 14C having a thickness of 50 μm or less, the degradation of translucency can be suppressed. In addition, the reduction in the bending resistance of the recording medium 10 can also be suppressed and defects such as cracks are less likely to occur. The thicknesses of the intermediate layers 14A, 14B and 14C can be the same as or different from each other.

[0193] The intermediate layer 14A includes a resin layer 14A1 and a pressure-sensitive adhesive layer 14A2 on the recording layer 13A in sequence. The resin layer 14A1 can suppress the diffusion of the constituent materials (e.g., the first and second coloring compounds, etc.) between the recording layer 13A and the recording layer 13B. The resin layer 14A1 can be thermally insulated between the recording layer 13A and the recording layer 13B. The pressure-sensitive adhesive layer 14A2 joins the resin layer 14A1 and the recording layer 13B together. The pressure-sensitive adhesive layer 14A2 can be thermally insulated between the recording layer 13A and the recording layer 13B.

[0194] Intermediate layer 14B includes resin layer 14B1 and pressure-sensitive adhesive layer 14B2 on recording layer 13B in sequence. Resin layer 14B1 can suppress the diffusion of constituent materials (e.g., second and third coloring compounds, etc.) between recording layer 13B and recording layer 13C. Resin layer 14B1 can be thermally isolated between recording layer 13B and recording layer 13C. Pressure-sensitive adhesive layer 14B2 joins resin layer 14B1 and recording layer 13C together. Pressure-sensitive adhesive layer 14B2 can be thermally isolated between recording layer 13B and recording layer 13C.

[0195] The intermediate layer 14C includes a resin layer 14C1, a pressure-sensitive adhesive layer 14C2, and a resin layer 14C3 in order on the recording layer 13C. The resin layers 14C1 and 14C3 can suppress diffusion of constituent materials (eg, a third coloring compound, etc.) between the recording layer 13C and the UV cutting layer 15.

[0196] The resin layers 14C1 and 14C3 can insulate heat between the recording layer 13C and the UV cutting layer 15. The pressure-sensitive adhesive layer 14C2 bonds the resin layer 14C1 and the resin layer 14C3 together. The pressure-sensitive adhesive layer 14C2 can insulate heat between the recording layer 13C and the UV cutting layer 15.

[0197] The pressure-sensitive adhesive layers 14A2 , 14B2 , and 14C2 are, for example, double-sided adhesive films such as optically clear adhesive (OCA).

[0198] The resin layer 14A1 preferably has solubility in methyl ethyl ketone. Since the resin layer 14A1 has solubility in methyl ethyl ketone, a first compatible region can be formed between the recording layer 13A and the resin layer 14A1 by applying a first recording layer forming coating containing methyl ethyl ketone on the resin layer 14A1 in the manufacturing step of the recording medium 10. The details of the first compatible region will be described later.

[0199] Whether the resin layer 14A1 has solubility in methyl ethyl ketone can be confirmed as follows. First, the surface of the resin layer 14A1 is exposed by peeling off the pressure-sensitive adhesive layer 14A2 from the surface of the resin layer 14A1 or polishing the recording medium 10 with a slicer or the like, and then a cotton swab impregnated with methyl ethyl ketone is pressed on the exposed surface and reciprocated multiple times (for example, 50 times or more). Thereafter, it is checked whether the lower layer (recording layer 13A) of the resin layer A1 is exposed. In the case where the lower layer is exposed, it is judged that the resin layer 14A1 has solubility in methyl ethyl ketone.

[0200] The resin layer 14B1 preferably has solubility in methyl ethyl ketone. Since the resin layer 14B1 has solubility in methyl ethyl ketone, a second compatible region can be formed between the recording layer 13B and the resin layer 14B1 by applying a second recording layer forming coating containing methyl ethyl ketone to the resin layer 14B1 in the manufacturing step of the recording medium 10. The details of the second compatible region will be described later.

[0201] Whether the resin layer 14B1 is soluble in methyl ethyl ketone can be confirmed by the same procedure as the solubility of the resin layer 14A1 described above.

[0202] The resin layer 14C1 preferably has solubility in methyl ethyl ketone. Since the resin layer 14C1 has solubility in methyl ethyl ketone, a third compatible region can be formed between the recording layer 13C and the resin layer 14C1 by applying a third recording layer forming coating containing methyl ethyl ketone to the resin layer 14C1 in the manufacturing step of the recording medium 10. The details of the third compatible region will be described later.

[0203] Whether the resin layer 14C1 is soluble in methyl ethyl ketone can be confirmed by the same procedure as the solubility of the resin layer 14A1 described above.

[0204] The resin layers 14A1, 14B1, and 14C1 contain an ultraviolet curable resin cured by a polymerization reaction and a polycarbonate resin (a second polycarbonate resin) as a thermoplastic resin. More specifically, for example, the resin layers 14A1, 14B1, and 14C1 contain: a polymer of a polymerizable compound; a substance in which a polymerization initiator generates an active substance by irradiating with external energy (ultraviolet rays) to change the structure; and a polycarbonate resin. Since the resin layers 14A1, 14B1, and 14C1 contain polycarbonate resin, the peel strength at the interface between the recording layer 13A and the resin layer 14A1, the interface between the recording layer 13B and the resin layer 14B1, and the interface between the recording layer 13C and the resin layer 14C1 can be increased compared to the case where the resin layers 14A1, 14B1, and 14C1 contain only ultraviolet curable resin. Therefore, it is possible to make it difficult to illegally separate the recording medium 10 at each of the above interfaces.

[0205] (UV curing resin)

[0206] For example, the ultraviolet curable resin component contains at least one selected from the group consisting of free radical polymerization ultraviolet curable resin components, cationic polymerization ultraviolet curable resin components, etc. If necessary, the ultraviolet curable resin composition may contain at least one selected from the group consisting of a sensitizer, a filler, a stabilizer, a leveling agent, a defoaming agent, a viscosity modifier, etc. From the viewpoint of suppressing diffusion of materials between layers via the resin layers 14A1, 14B1, and 14C1, the ultraviolet curable resin preferably contains an ultraviolet curable resin for a hard coat layer.

[0207] The polymerizable compound includes, for example, at least one of a monofunctional polymerizable compound or a multifunctional polymerizable compound. The lower limit of the number of functional groups of the polymerizable compound is preferably two or more, more preferably three or more, and even more preferably four or more. By making the number of functional groups of the polymerizable compound 2 or more, the crosslinking density of the resin layers 14A1, 14B1, and 14C1 can be increased, and the function of the resin layers 14A1, 14B1, and 14C1 as diffusion suppression layers can be increased. The upper limit of the number of functional groups of the polymerizable compound is, for example, 8 or less, 7 or less, or 6 or less.

[0208] The polymerizable compound may include one polymerizable compound or two or more polymerizable compounds. The ultraviolet curable resin includes a polymerizable compound having at least one ultraviolet reactive group. For example, the ultraviolet curable resin includes at least one selected from a monomer including at least one ultraviolet reactive group, an oligomer including at least one ultraviolet reactive group, and a prepolymer including at least one ultraviolet reactive group as a polymerizable compound. For example, at least one ultraviolet reactive group includes at least one selected from a group including a free radical polymerization reactive group with an ethylenically unsaturated bond, a cationic polymerization reactive group, etc. At least one free radical polymerization reactive group with an ethylenically unsaturated bond includes, for example, at least one selected from a group including acryloyl, methacryloyl, allyl, vinyl, etc. Among them, it is preferably selected from at least one of the groups including acryloyl, methacryloyl and oxetane, and more preferably selected from at least one of the groups including acryloyl and methacryloyl. That is, (meth) acrylate is more preferred. Note that in this specification, (meth) acrylate is a general term for acrylate, methacrylate, and a mixture of these. The at least one cationically polymerizable group includes, for example, an oxetane group.

[0209] Examples of (meth)acrylates include urethane (meth)acrylates, silicone (meth)acrylates, alkyl (meth)acrylates, aryl (meth)acrylates, and the like. (Meth)acrylates may include only monofunctional (meth)acrylates, may include multifunctional (meth)acrylates, or may include a combination of monofunctional (meth)acrylates and multifunctional (meth)acrylates. (Meth)acrylates more preferably include multifunctional (meth)acrylates.

[0210] Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, propyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, isobutyl (meth)acrylate, tert- ... Nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, bornyl (meth)acrylate, tricyclodecyl (meth)acrylate, 1-butyl ... dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxy-2-methylethyl (meth)acrylate, phenoxyethoxyethyl (meth)acrylate, 3-phenoxy-2-hydroxypropyl (meth)acrylate, 2-phenylphenoxyethyl (meth)acrylate, 4-phenylphenoxyethyl (meth)acrylate, 3-(2-phenyl)-2-hydroxypropyl (meth)acrylate, phenyl)-2-hydroxypropyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol (meth)acrylate, ethoxyethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and the like.

[0211] Examples of the multifunctional (meth)acrylate include difunctional (meth)acrylate, trifunctional (meth)acrylate, tetrafunctional (meth)acrylate, and the like. More specifically, embodiments include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol tetra(meth)acrylate, tripentaerythritol penta(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, and the like.

[0212] The lower limit of the content of the ultraviolet curable resin in the resin layer 14A1 is preferably 67% by mass or more, and more preferably 75% by mass or more. When the content of the ultraviolet curable resin in the resin layer 14A1 is 67% by mass or more, the function of the resin layer 14A1 as a diffusion suppression layer can be improved by increasing the crosslinking density of the resin layer 14A1. Therefore, the reduction in drawing characteristics and the change in color gamut can be suppressed.

[0213] The upper limit of the content of the ultraviolet curable resin in the resin layer 14A1 is preferably 85% by mass or less, and more preferably 80% by mass or less. When the content of the ultraviolet curable resin in the resin layer 14A1 is 85% by mass or less, the reduction in the content of the polycarbonate resin in the resin layer 14A1 can be suppressed.

[0214] The lower limit value of the content of the ultraviolet curable resin in the resin layer 14B1 is preferably 67% by mass or more, and more preferably 75% by mass or more. When the content of the ultraviolet curable resin in the resin layer 14B1 is 67% by mass or more, the function of the resin layer 14B1 as a diffusion suppression layer can be improved by increasing the crosslinking density of the resin layer 14B1. Therefore, the reduction in drawing characteristics and the change in color gamut can be suppressed.

[0215] The upper limit of the content of the ultraviolet curable resin in the resin layer 14B1 is preferably 85% by mass or less, and more preferably 80% by mass or less. When the content of the ultraviolet curable resin in the resin layer 14B1 is 85% by mass or less, the reduction in the content of the polycarbonate resin in the resin layer 14B1 can be suppressed.

[0216] The lower limit value of the content of the ultraviolet curable resin in the resin layer 14C1 is preferably 67% by mass or more, and more preferably 75% by mass or more. When the content of the ultraviolet curable resin in the resin layer 14C1 is 67% by mass or more, the function of the resin layer 14C1 as a diffusion suppression layer can be improved by increasing the crosslinking density of the resin layer 14C1. Therefore, the reduction in drawing characteristics and the change in color gamut can be suppressed.

[0217] The upper limit of the content of the ultraviolet curable resin in the resin layer 14C1 is preferably 85% by mass or less, and more preferably 80% by mass or less. When the content of the ultraviolet curable resin in the resin layer 14C1 is 85% by mass or less, the reduction in the content of the polycarbonate resin in the resin layer 14C1 can be suppressed.

[0218] The content of the ultraviolet curable resin in the resin layer 14A1 is determined as follows. First, the surface of the resin layer 14A1 is exposed by peeling the pressure-sensitive adhesive layer 14A2 from the surface of the resin layer 14A1, or by polishing the recording medium 10 with a microtome or the like. Next, the resin layer 14A1 is analyzed by a Fourier transform infrared spectrometer (micro-FTIR) to determine the content of the ultraviolet curable resin in the resin layer 14A1.

[0219] The contents of the ultraviolet curable resin in the resin layers 14B1 and 14C1 are also determined in a procedure similar to the method for measuring the content of the ultraviolet curable resin in the resin layer 14A1 .

[0220] (Polycarbonate resin)

[0221] The polycarbonate resin is a resin having a carbonate group (-O-(C=O)-O-) as a structural unit at least in the main chain. Therefore, the polycarbonate resin may have other structural units in addition to the carbonate group in the main chain. The polycarbonate resin preferably has at least one ultraviolet reactive group. When the polycarbonate resin has at least one ultraviolet reactive group, the polymerizable compound contained in the ultraviolet curable resin can be bonded to the polycarbonate resin. Therefore, the crosslinking density of the resin layers 14A1, 14B1, 14C1 can be increased, and the function of the resin layers 14A1, 14B1, 14C1 as diffusion suppression layers can be improved.

[0222] For example, at least one ultraviolet reactive group includes at least one selected from the group including free radical polymerization reactive groups having ethylenically unsaturated bonds, cation polymerization reactive groups, etc. At least one free radical polymerization reactive group having ethylenically unsaturated bonds includes, for example, at least one selected from the group including acryloyl, methacryloyl, allyl, vinyl, etc. Among them, preferably at least one selected from the group including acryloyl, methacryloyl and vinyl, more preferably at least one selected from the group including acryloyl and methacryloyl. Cationic polymerization reactive groups include, for example, oxetane, etc.

[0223] The lower limit of the content of the polycarbonate resin in the resin layer 14A1 is preferably 15% by mass or more, and more preferably 20% by mass or more. When the content of the polycarbonate resin in the resin layer 14A1 is 15% by mass or more, the solubility of the resin layer 14A1 in the solvent (e.g., methyl ethyl ketone) contained in the first recording layer forming coating material tree increases, and the first compatible area is easily formed. Therefore, peeling at the interface between the recording layer 13A and the resin layer 14A1 becomes difficult. Therefore, it becomes difficult to tamper with the recording medium 10 by illegally separating the recording medium 10 at the interface between the recording layer 13A and the resin layer 14A1. Note that the details of the first compatible area will be described later.

[0224] The upper limit of the content of the polycarbonate resin in the resin layer 14A1 is preferably 33% by mass or less, and more preferably 25% by mass or less. When the content of the polycarbonate resin in the resin layer 14A1 is 33% by mass or less, the reduction in the content of the ultraviolet curable resin in the resin layer 14A1 can be suppressed.

[0225] The lower limit of the content of the polycarbonate resin in the resin layer 14B1 is preferably 15% by mass or more, and more preferably 20% by mass or more. When the content of the polycarbonate resin in the resin layer 14B1 is 15% by mass or more, the solubility of the resin layer 14B1 in the solvent (e.g., methyl ethyl ketone) contained in the second recording layer forming coating tree increases, and the second compatible area is easily formed. Therefore, the peeling at the interface between the recording layer 13B and the resin layer 14B1 becomes difficult. Therefore, by illegally separating the recording medium 10 at the interface between the recording layer 13B and the resin layer 14B1, it becomes difficult to tamper with the recording medium 10. Note that the details of the second compatible area will be described later.

[0226] The upper limit of the content of the polycarbonate resin in the resin layer 14B1 is preferably 33% by mass or less, and more preferably 25% by mass or less. When the content of the polycarbonate resin in the resin layer 14B1 is 33% by mass or less, the reduction in the content of the ultraviolet curable resin in the resin layer 14B1 can be suppressed.

[0227] The lower limit of the content of the polycarbonate resin in the resin layer 14C1 is preferably 15% by mass or more, and more preferably 20% by mass or more. When the content of the polycarbonate resin in the resin layer 14C1 is 15% by mass or more, the solubility of the resin layer 14C1 in the solvent (e.g., methyl ethyl ketone) contained in the third recording layer forming coating tree increases, and the third compatible area is easily formed. Therefore, the peeling at the interface between the recording layer 13C and the resin layer 14C1 becomes difficult. Therefore, it becomes difficult to tamper with the recording medium 10 by illegally separating the recording medium 10 at the interface between the recording layer 13C and the resin layer 14C1. Note that the details of the third compatible area will be described later.

[0228] The upper limit of the content of the polycarbonate resin in the resin layer 14C1 is preferably 33% by mass or less, and more preferably 25% by mass or less. When the content of the polycarbonate resin in the resin layer 14C1 is 33% by mass or less, the reduction in the content of the ultraviolet curable resin in the resin layer 14C1 can be suppressed.

[0229] The content of the polycarbonate resin in the resin layers 14A1 , 14B1 , and 14C1 is determined in a procedure similar to the method for measuring the content of the ultraviolet curing resin in the resin layers 14A1 , 14B1 , and 14C1 .

[0230] (UV cutting layer 15)

[0231] The UV cutting layer 15 is a filter layer having a spectral characteristic of transmitting visible light and shielding ultraviolet rays. The UV cutting layer 15, for example, contains at least one ultraviolet absorber. For example, the at least one ultraviolet absorber includes at least one selected from the group consisting of triazine ultraviolet absorbers, benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, oxybenzophenone ultraviolet absorbers, salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, and the like.

[0232] (cover layer 16)

[0233] The cover layer 16 covers the upper surface (the surface on the side opposite to the substrate 11) of the recording medium 10. The cover layer 16 is preferably transmissive to laser light and visible light used for drawing on the recording medium 10. The cover layer 16 is, for example, a film. As a material of the film, a material similar to the polymer material of the substrate 11 can be exemplified.

[0234] (Compatible Area)

[0235] The recording medium 10 preferably has at least one of the first compatible region, the second compatible region, or the third compatible region, and particularly preferably has all of these regions. The first compatible region is a region between the recording layer 13A and the resin layer 14A1, and is a region where the materials contained in the recording layer 13A and the resin layer 14A1 are mixed. The second compatible region is a region between the recording layer 13B and the resin layer 14B1, and is a region where the materials contained in the recording layer 13B and the resin layer 14B1 are mixed. The third compatible region is a region between the recording layer 13C and the resin layer 14C1, and is a region where the materials contained in the recording layer 13C and the resin layer 14C1 are mixed.

[0236] From the viewpoint of improving the peel strength between the recording layer 13A and the resin layer 14A1, it is preferred that the content of the polycarbonate resin in the first compatible region continuously changes in the thickness direction of the recording medium 10. In the first compatible region, the content of the polycarbonate resin may increase from the recording layer 13A toward the resin layer 14A1, or may increase from the resin layer 14A1 toward the recording layer 13A.

[0237] From the viewpoint of improving the peel strength between the recording layer 13B and the resin layer 14B1, it is preferred that the content of the polycarbonate resin in the second compatible region continuously changes in the thickness direction of the recording medium 10. In the second compatible region, the content of the polycarbonate resin may increase from the recording layer 13B toward the resin layer 14B1, or may increase from the resin layer 14B1 toward the recording layer 13B.

[0238] From the viewpoint of improving the peel strength between the recording layer 13C and the resin layer 14C1, it is preferred that the content of the polycarbonate resin in the third compatible region continuously changes in the thickness direction of the recording medium 10. In the third compatible region, the content of the polycarbonate resin may increase from the recording layer 13C toward the resin layer 14C1, or may increase from the resin layer 14C1 toward the recording layer 13C.

[0239] From the viewpoint of improving the peel strength between the recording layer 13A and the resin layer 14A1, it is preferred that the content of the ultraviolet curable resin in the first compatible region continuously changes in the thickness direction of the recording medium 10. The content of the ultraviolet curable resin in the first compatible region may increase from the recording layer 13A toward the resin layer 14A1.

[0240] From the viewpoint of improving the peel strength between the recording layer 13B and the resin layer 14B1, it is preferred that the content of the ultraviolet curable resin in the second compatible region continuously changes in the thickness direction of the recording medium 10. The content of the ultraviolet curable resin in the second compatible region may increase from the recording layer 13B toward the resin layer 14B1.

[0241] From the viewpoint of improving the peel strength between the recording layer 13C and the resin layer 14C1, it is preferred that the content of the ultraviolet curable resin in the third compatible region continuously changes in the thickness direction of the recording medium 10. The content of the ultraviolet curable resin in the third compatible region may increase from the recording layer 13C toward the resin layer 14C1.

[0242] From the viewpoint of improving the peel strength between the recording layer 13A and the resin layer 14A1, it is preferred that the content of the polymerizable compound in the first compatible region continuously changes in the thickness direction of the recording medium 10. The content of the polymerizable compound in the first compatible region may increase from the recording layer 13A toward the resin layer 14A1.

[0243] From the viewpoint of improving the peel strength between the recording layer 13B and the resin layer 14B1, it is preferred that the content of the polymerizable compound in the second compatible region continuously changes in the thickness direction of the recording medium 10. The content of the polymerizable compound in the second compatible region may increase from the recording layer 13B toward the resin layer 14B1.

[0244] From the viewpoint of improving the peel strength between the recording layer 13C and the resin layer 14C1, it is preferred that the content of the polymerizable compound in the third compatible region continuously changes in the thickness direction of the recording medium 10. The content of the polymerizable compound in the third compatible region may increase from the recording layer 13C toward the resin layer 14C1.

[0245] (Average peel strength)

[0246] The average peel strength at the interface between the recording layer 13A and the resin layer 14A1 is preferably 3.5 N / cm or more, more preferably 4.0 N / cm or more, and even more preferably 5.0 N / cm or more. When the average peel strength at the interface between the recording layer 13A and the resin layer 14A1 is 3.5 N / cm or more, peeling at the interface between the recording layer 13A and the resin layer 14A1 becomes difficult. Therefore, it becomes difficult to tamper with the recording medium 10 by illegally separating the recording medium 10 at the interface between the recording layer 13A and the resin layer 14A1.

[0247] The average peel strength at the interface between the recording layer 13B and the resin layer 14B1 is preferably 3.5 N / cm or more, more preferably 4.0 N / cm or more, and even more preferably 5.0 N / cm or more. When the average peel strength at the interface between the recording layer 13B and the resin layer 14B1 is 3.5 N / cm or more, peeling at the interface between the recording layer 13B and the resin layer 14B1 becomes difficult. Therefore, it becomes difficult to tamper with the recording medium 10 by illegally separating the recording medium 10 at the interface between the recording layer 13B and the resin layer 14B1.

[0248] The average peel strength at the interface between the recording layer 13C and the resin layer 14C1 is preferably 3.5 N / cm or more, more preferably 4.0 N / cm or more, and even more preferably 5.0 N / cm or more. When the average peel strength at the interface between the recording layer 13C and the resin layer 14C1 is 3.5 N / cm or more, peeling at the interface between the recording layer 13C and the resin layer 14C1 becomes difficult. Therefore, it becomes difficult to tamper with the recording medium 10 by illegally separating the recording medium 10 at the interface between the recording layer 13B and the resin layer 14B1.

[0249] The average peel strength at all interfaces between the recording layer 13A and the resin layer 14A1, between the recording layer 13B and the resin layer 14B1, and between the recording layer 13C and the resin layer 14C1 is preferably 3.5 N / cm or more, more preferably 4.0 N / cm or more, and still more preferably 5.0 N / cm or more from the viewpoint of more reliably preventing tampering of the recording medium 10. In this case, the peel strength at each interface between the recording layer 13A and the resin layer 14A1, between the recording layer 13B and the resin layer 14B1, and between the recording layer 13C and the resin layer 14C1 may be different or the same.

[0250] The average peel strength of the interface between the recording layer 13A and the resin layer 14A1 was determined by performing a 90-degree peel test. Figure 2 Describe the 90 degree peel test.

[0251] First, recording medium 10 is cut into the band shape with 10mm width and 100mm length to prepare sample 60, and sample 60 is placed 24 hours or longer under 23±1 ℃ temperature and 50±5% relative humidity in the atmosphere under standard state. Below, in sample 60, the laminate below the interface of recording layer 13A and resin layer 14A1 is called adherend 60A, and the laminate above the interface is called adherend 60B. Then, at one end of the length direction of sample 60, sharp blades such as cutters are utilized to form incisions between adherend 60A and adherend 60B, adherend 60B is peeled off 20mm in the length direction and prepares to grasp the edge, then, the surface of the adherend 60A side of sample 60 is fixed on the test bench 71 utilizing strong pressure-sensitive adhesive. As the pressure-sensitive adhesive, a pressure-sensitive adhesive having sufficiently high pressure-sensitive adhesive force, such as Strong Pressure-Sensitive Adhesive Tape Clear (registered trademark) manufactured by 3M Company, is selected so that the sample 60 does not peel off from the test stand 71 when measuring the peel strength between the recording layer 13A and the resin layer 14A1.

[0252] Next, one end of the tension member 61 is bonded to the surface on the resin layer 14A1 side of the adherend 60B. As the tension member 61, a belt-shaped film having sufficient strength is used, which does not cause elongation or breakage during the measurement of the peel strength. In addition, one end of the tension member 61 is bonded to the adherend 60B with a sufficiently high pressure-sensitive adhesive force so that the tension member 61 does not peel off from the adherend 60A when the peel strength is measured. Figure 2 Although the tension member 61 is shown as an example of a gripping edge, if the stroke of the clamping device (metal plate) 62 is sufficient to clamp the adherend 60B, the adherend 60B may be clamped directly without using the tension member 61 .

[0253] Next, the gripping edge of the tension member 61 is inserted between a set of movable rollers 73A and 73B of the clamp 72, and then the gripping edge is clamped and fixed by more than 10 mm by the clamping device (metal plate) 62 of the tensile compression tester SV-55C2H manufactured by IMADA-SS. In the 90-degree peel test, the movable rollers 73A and 73B are used as fulcrums for peeling. Next, the 90-degree peel test is performed using the tensile compression tester, while the test force [N / cm] and stroke [mm] are monitored in terms of voltage value by a data recorder manufactured by, for example, Keyence Corporation, and the voltage value is converted into force and stored in a memory as CSV output data. In addition, the above-mentioned 90-degree peel test is performed at a tensile speed of 5 mm / second under standard conditions of temperature 23±1°C and relative humidity 50±5%. The stroke is set to be more than 50 mm.

[0254] The above-mentioned 90-degree peel test was performed three times in total, wherein the point where the peel strength was stable (the position where the development of the force became moderate) was taken as the starting point (0 mm), and the CSV output data up to the point at a relative distance of 50 mm from the starting point were arithmetic averaged to calculate the average value. As a result, the average peel strength between the recording layer 13A and the resin layer 14A1 was obtained. However, in the case where there was a point (peak value) where the peel force suddenly decreased in the CSV output data, the point (peak value) was excluded from the CSV output data, and the average peel strength was calculated.

[0255] The peel strength at the interface between the recording layer 13B and the resin layer 14B1 and the peel strength at the interface between the recording layer 13C and the resin layer 14C1 are obtained in the same procedure as the peel strength at the interface between the recording layer 13A and the resin layer 14A1.

[0256] (Average value of minimum peel strength)

[0257] Among the peel strengths between the layers constituting the recording medium 10, the average value of the minimum peel strength is preferably 3.5 N / cm or more, more preferably 4.0 N / cm or more, and still more preferably 5.0 N / cm or more. When the average value of the minimum peel strength is 3.5 N / cm or more as described above, peeling becomes difficult at the interface between the layers constituting the recording medium 10. Therefore, it becomes difficult to tamper with the recording medium 10 by illegally separating the recording medium 10 at the interface between the layers constituting the recording medium 10.

[0258] The average value of the minimum peel strength among the peel strengths between the layers constituting the recording medium 10 is obtained by performing a 90-degree peel test. Figure 3 A and Figure 3 B describes the 90 degree peel test.

[0259] First, the recording medium 10 is cut into a strip having a width of 10 mm and a length of 100 mm to prepare a sample 60, and the sample 60 is placed in an atmosphere under a standard state at a temperature of 23±1° C. and a relative humidity of 50±5% for 24 hours or more. Figure 3 As shown in FIG. 7A, the surface of the sample 60 on the substrate 11 side is fixed to the test table 71 using a strong pressure-sensitive adhesive, and the tension member 61 is bonded to the surface of the sample 60 on the cover layer 16 side. As the tension member 61, a tape-shaped film having sufficient strength that does not cause elongation or breakage during the measurement of the average peel strength is used. In addition, one end of the tension member 61 is bonded to the surface of the sample 60 on the cover layer 16 side with a sufficiently high pressure-sensitive adhesive force so as not to be peeled off from the sample 60 when the average peel strength is measured.

[0260] Next, if Figure 3 B, the gripping edge of tension member 61 is inserted between one group of movable rollers 73A and the 73B of fixture 72, then by the clamping device (metal plate) 63 of the tensile compression tester SV-55C2H made by IMADA-SS company gripping edge clamping and fixing more than 10mm.The following step is identical with the method for the average peel strength between mensuration adherend 60A and adherend 60B.As mentioned above, obtain the mean value of the minimum peel strength in the peel strength between each layer that constitutes recording medium 10.

[0261] [Method of Manufacturing Recording Medium]

[0262] Hereinafter, an example of a method of manufacturing the recording medium 10 according to the first embodiment will be described.

[0263] (Step of forming a first laminate film)

[0264] First, the first matrix resin is dissolved in a solvent. The solvent preferably includes a solvent capable of dissolving the surface of the resin layer 14A1. For example, the solvent preferably includes methyl ethyl ketone (MEK). Then, the first coloring compound, the first developer and the first photothermal conversion agent in an uncolored state are added and dispersed in the solution. As a result, a first recording layer is prepared to form a coating material. Then, a resin layer is prepared by mixing a polycarbonate resin and an ultraviolet curing resin to form a coating. At this point, a solvent can be further mixed as needed. The solvent can include at least one selected from the group including methyl ethyl ketone, ethyl acetate, toluene, etc.

[0265] Next, after applying the resin layer forming coating material on the flat surface, the solvent of the resin layer forming coating material is dried as needed, and the resin layer forming coating material is irradiated with ultraviolet rays and cured to form the resin layer 14A1. Note that the resin layer 14A1 can be formed by applying an ultraviolet curing resin to a film, and then irradiating the resin layer forming coating material with ultraviolet rays to cure the resin layer forming coating material. In this case, the film may be brought into the recording medium 10 or may be removed during the manufacturing step of the recording medium 10.

[0266] Next, the first recording layer forming coating material is applied to the resin layer 14A1, and dried and cured to form the recording layer 13A. At this time, the surface of the resin layer 14A1 is preferably dissolved with a solvent such as methyl ethyl ketone contained in the first recording layer forming coating material. By dissolving the surface of the resin layer 14A1 in this way, a first compatible region is formed between the recording layer 13A and the resin layer 14A1. In this way, a first laminated film including the resin layer 12A1 and the recording layer 13A is obtained.

[0267] (Step of forming a second laminate film)

[0268] The second recording layer forming coating material is prepared using a second matrix resin, a second coloring compound, a second developer, and a second photothermal conversion agent instead of the first matrix resin, the first coloring compound, the first developer, and the first photothermal conversion agent. Except for this, a second laminated film including a resin layer 14B1 and a recording layer 13B is obtained similarly to the step of forming the first laminated film. Also in the step of forming the second laminated film, it is preferred that the surface of the resin layer 14B1 is dissolved by a solvent such as methyl ethyl ketone contained in the second recording layer forming coating material, and a second compatible region is formed between the recording layer 13B and the resin layer 14B1.

[0269] (Step of forming the third laminate film)

[0270] The third recording layer forming coating material is prepared using a third matrix resin, a third coloring compound, a third developer, and a third photothermal conversion agent instead of the first matrix resin, the first coloring compound, the first developer, and the first photothermal conversion agent. Except for this, a third laminated film including a resin layer 14C1 and a recording layer 13C is obtained similarly to the step of forming the first laminated film. In addition, in the step of forming the third laminated film, it is preferred that the surface of the resin layer 14C1 is dissolved by a solvent such as methyl ethyl ketone contained in the third recording layer forming coating material, and a third compatible region is formed between the recording layer 13C and the resin layer 14C1.

[0271] (Lamination Step)

[0272] First, a fourth laminate film having a cover layer 16, a pressure-sensitive adhesive layer 12B, a UV cutting layer 15, a resin layer 14C3, and a pressure-sensitive adhesive layer 14C2 is prepared in this order. Next, after forming the pressure-sensitive adhesive layer 12A on the substrate 11, the first laminate film is bonded to the pressure-sensitive adhesive layer 12A so that the recording layer 13A and the pressure-sensitive adhesive layer 12A are in contact with each other.

[0273] Next, after the pressure-sensitive adhesive layer 14A2 is formed on the resin layer 14A1, a second lamination film is bonded onto the pressure-sensitive adhesive layer 14A2 so that the recording layer 13B and the pressure-sensitive adhesive layer 14A2 are in contact with each other.

[0274] Next, after the pressure-sensitive adhesive layer 14B2 is formed on the resin layer 14B1 , the third laminate film is bonded onto the pressure-sensitive adhesive layer 14B2 so that the recording layer 13C and the pressure-sensitive adhesive layer 14B2 are in contact with each other.

[0275] Next, the fourth laminate film is bonded to the resin layer 14C1 so that the resin layer 14C1 and the pressure-sensitive adhesive layer 14C2 are in contact with each other. Figure 1 The recording medium 10 is shown in FIG.

[0276] [Recording method of recording medium]

[0277] Hereinafter, an example of a recording method of the recording medium 10 according to the first embodiment will be described.

[0278] The recording layer 13A forms a magenta color as follows. When a predetermined position of the recording layer 13A is irradiated with a near-infrared laser having a first peak wavelength λ1, the first photothermal conversion agent contained in the portion irradiated with the laser absorbs the near-infrared laser and generates heat. Due to the heat generation, the first developer melts, a color reaction (color development reaction) occurs between the first developer and the first coloring compound, and the portion irradiated with the laser develops a magenta color.

[0279] The recording layer 13B generates cyan as follows: When a predetermined position of the recording layer 13B is irradiated with near-infrared laser light having the second peak wavelength λ2, the portion irradiated with the laser light forms cyan through a reaction similar to that of the above-described recording layer 13A.

[0280] The recording layer 13C forms yellow as follows: When a predetermined position of the recording layer 13B is irradiated with near-infrared laser light having the third peak wavelength λ3, the portion irradiated with the laser light develops yellow through a reaction similar to that of the above-described recording layer 13A.

[0281] As described above, predetermined positions of the recording layers 13A, 13B, and 13C develop magenta, cyan, and yellow, respectively, thereby drawing a desired full-color image on the recording medium 10 .

[0282] [Operation and Effect]

[0283] In the recording medium 10 according to the first embodiment, the resin layers 14A1, 14B1, and 14C1 contain ultraviolet curing resin and polycarbonate resin. Therefore, in the manufacturing step of the recording medium 10, when the first, second, and third recording layer forming coating materials are applied to the resin layers 14A1, 14B1, and 14C1, respectively, the surfaces of the resin layers 14A1, 14B1, and 14C1 are easily dissolved. As a result, in the manufacturing step of the recording medium 10, the first compatible region, the second compatible region, and the third compatible region can be formed between the recording layer 13A and the resin layer 14A1, between the recording layer 13B and the resin layer 14B1, and between the recording layer 13C and the resin layer 14C1, respectively. Therefore, compared with the case where the resin layers 14A1, 14B1, and 14C1 contain only ultraviolet curing resin, the peel strength at the interface between the recording layer 13A and the resin layer 14A1, the interface between the recording layer 13B and the resin layer 14B1, and the interface between the recording layer 13C and the resin layer 14C1 can be increased. Therefore, it is possible to make it difficult to illegally separate the recording medium 10 at each of the above interfaces. That is, it is possible to make it difficult to tamper with the recording medium 10.

[0284] In addition, the resin layers 14A1, 14B1, and 14C1 contain ultraviolet curing resin, thereby improving the function of the resin layers 14A1, 14B1, and 14C1 as diffusion suppression layers.

[0285] [Modifications]

[0286] (Variant 1)

[0287] In the first embodiment, the resin layer 14A1, the resin layer 14B1, and the resin layer 14C1 each contain an ultraviolet curable resin and a polycarbonate resin, but the present disclosure is not limited to this embodiment. For example, one or two of the resin layer 14A1, the resin layer 14B1, and the resin layer 14C1 may contain an ultraviolet curable resin and a polycarbonate resin, and the remaining layers may contain an ultraviolet curable resin.

[0288] (Variant 2)

[0289] In the first embodiment, an example in which the intermediate layer 14A includes the resin layer 14A1 and the pressure-sensitive adhesive layer 14A2 has been described, but the intermediate layer 14A may include only the resin layer 14A1. Similarly, the intermediate layer 14B may include only the resin layer 14A1, or the intermediate layer 14C may include only the resin layer 14C1. The cover layer 16 and the pressure-sensitive adhesive layer 12B may be omitted, or the substrate 11 and the pressure-sensitive adhesive layer 12A may be omitted.

[0290] (Variant 3)

[0291] In the first embodiment, an embodiment in which the recording medium 10 includes three recording layers 13A, 13B and 13C has been described. However, the recording medium 10 may include one recording layer or may include multiple recording layers other than three (i.e., two recording layers or more than four recording layers). In this case as well, an intermediate layer may be provided between the laminated recording layers. The multiple recording layers can respectively exhibit different hues from each other in the color development state. That is, the coloring compounds respectively included in the multiple recording layers can exhibit different hues from each other in the color development state. The photothermal conversion agents respectively included in the multiple recording layers may have different absorption wavelength peaks from each other.

[0292] (Variant 4)

[0293] In the first embodiment, the recording layers 13A, 13B and 13C include polycarbonate resin, and the resin layers 14A1, 14B1 and 14C1 include an embodiment of polycarbonate resin and ultraviolet curing resin, but the present disclosure is not limited to this embodiment. For example, the recording layers 13A, 13B and 13C may include a first thermoplastic resin instead of a polycarbonate resin, and the resin layers 14A1, 14B1 and 14C1 may include a second thermoplastic resin of the same type as the first thermoplastic resin. Alternatively, the recording layers 13A, 13B and 13C may include a first thermoplastic resin together with a polycarbonate resin, and the resin layers 14A1, 14B1 and 14C1 may include a second thermoplastic resin of the same type as the first thermoplastic resin. The first and second thermoplastic resins preferably have at least one ultraviolet reactive group. A specific embodiment of at least one ultraviolet reactive group includes an ultraviolet reactive group similar to at least one ultraviolet reactive group of the polycarbonate resin included in the resin layers 14A1, 14B1 and 14C1. For example, the first thermoplastic resin and the second thermoplastic resin include at least one selected from the group consisting of polystyrene resin, polyvinyl acetate resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, and the like.

[0294] <2 Second Embodiment>

[0295] [Configuration of recording medium]

[0296] Figure 4 1 is a cross-sectional view showing an example of a configuration of a recording medium 10A according to the second embodiment. The recording medium 10A is different from the recording medium 10 according to the first embodiment in including intermediate layers 17A, 17B, and 17C instead of the intermediate layers 14A, 14B, and 14C.

[0297] (Middle layers 17A, 17B, 17C)

[0298] The intermediate layer 17A is different from the intermediate layer 14A in the first embodiment in that a pressure-sensitive adhesive layer 14A2 and a resin layer 14A1 are provided in this order on the recording layer 13A. In the second embodiment, the pressure-sensitive adhesive layer 14A2 bonds the recording layer 13A and the resin layer 14A1.

[0299] The intermediate layer 17B is different from the intermediate layer 14B in the first embodiment in that a pressure-sensitive adhesive layer 14B2 and a resin layer 14B1 are sequentially provided on the recording layer 13B. In the second embodiment, the pressure-sensitive adhesive layer 14B2 bonds the recording layer 13B and the resin layer 14B1.

[0300] The intermediate layer 17C is different from the intermediate layer 14C in the first embodiment in that a pressure-sensitive adhesive layer 14C2 and a resin layer 14C3 are sequentially provided on the recording layer 13C. In the second embodiment, the pressure-sensitive adhesive layer 14C2 bonds the recording layer 13C and the resin layer 14C3.

[0301] (Compatible Area)

[0302] The recording medium 10A preferably has at least one of the first compatible region or the second compatible region, and particularly preferably has both regions. The first compatible region is a region between the resin layer 14A1 and the recording layer 13B, and is a region where the materials contained in the resin layer 14A1 and the recording layer 13B are mixed. The second compatible region is a region between the resin layer 14B1 and the recording layer 13C, and is a region where the materials contained in the resin layer 14B1 and the recording layer 13C are mixed.

[0303] [Method of Manufacturing Recording Medium]

[0304] Hereinafter, an example of a method of manufacturing the recording medium 10A according to the second embodiment will be described.

[0305] (Step of Forming Recording Layer 13A)

[0306] The first recording layer forming coating material has been prepared similarly to the step of forming the first laminated film in the first embodiment. Next, the first recording layer forming coating is applied to the flat surface by a gravure application method, and dried and cured to obtain the recording layer 13A. Note that the recording layer 13A can be formed by applying the first recording layer forming coating material to the film and drying and curing the first recording layer forming coating material. In this case, the film can be brought into the recording medium 10A or can be removed during the manufacturing step of the recording medium 10A.

[0307] (Step of forming a second laminate film)

[0308] Similar to the step of forming the second laminated film in the first embodiment, a second laminated film including the resin layer 14A1 and the recording layer 13B is obtained.

[0309] (Step of forming the third laminate film)

[0310] Similar to the step of forming the third laminated film in the first embodiment, a third laminated film including the resin layer 14B1 and the recording layer 13C is obtained.

[0311] (Lamination Step)

[0312] First, a fourth laminate film having a cover layer 16, a pressure-sensitive adhesive layer 12B, a UV cutting layer 15, and a resin layer 14C3 is prepared in this order. Next, after forming a pressure-sensitive adhesive layer 14C2 on the resin layer 14C3 of the fourth laminate film, a third laminate film is bonded to the pressure-sensitive adhesive layer 14C2 so that the pressure-sensitive adhesive layer 14C2 and the recording layer 13C are in contact with each other.

[0313] Next, after the pressure-sensitive adhesive layer 14B2 is formed on the resin layer 14B1 , a second laminate film is bonded onto the pressure-sensitive adhesive layer 14B2 so that the pressure-sensitive adhesive layer 14B2 and the recording layer 13B are in contact with each other.

[0314] Next, after the pressure-sensitive adhesive layer 14A2 is formed on the resin layer 14A1, the recording layer 13A is bonded onto the pressure-sensitive adhesive layer 14A2 so that the pressure-sensitive adhesive layer 14A2 and the recording layer 13A are in contact with each other.

[0315] Next, the pressure-sensitive adhesive layer 12A is formed on the recording layer 13A, and then the substrate 11 is bonded to the pressure-sensitive adhesive layer 12A. In this way, a Figure 4 The recording medium 10A shown in FIG.

[0316] [Operation and Effect]

[0317] In the recording medium 10A according to the second embodiment, the resin layers 14A1 and 14B1 contain ultraviolet curing resin and polycarbonate resin. Therefore, in the manufacturing step of the recording medium 10A, when the second and third recording layer forming application resins are applied to the resin layer 14A1 and the resin layer 14B1, respectively, the surfaces of the resin layer 14A1 and the resin layer 14B1 are easily dissolved. As a result, in the manufacturing step of the recording medium 10A, the second compatible area and the third compatible area can be formed between the resin layer 14A1 and the constituent material of the recording layer 13B and between the resin layer 14B1 and the recording layer 13C, respectively. Therefore, compared with the case where the resin layers 14A1 and 14B1 contain only ultraviolet curing resin, the peel strength at the interface between the resin layer 14A1 and the recording layer 13B and the interface between the resin layer 14B1 and the recording layer 13C can be increased. Therefore, it is possible to make it difficult to illegally separate the recording medium 10A at each of the above interfaces. That is, it is possible to make it difficult to tamper with the recording medium 10A.

[0318] In addition, the resin layers 14A1 and 14B1 contain ultraviolet curing resin, thereby improving the function of the resin layers 14A1 and 14B1 as diffusion suppression layers.

[0319] [Modifications]

[0320] (Variant 1)

[0321] In the first embodiment, an example in which both the resin layer 14A1 and the resin layer 14B1 include an ultraviolet curable resin and a polycarbonate resin has been described, but the present disclosure is not limited to this example. For example, one of the resin layer 14A1 and the resin layer 14B1 may include an ultraviolet curable resin and a polycarbonate resin, and the other may include an ultraviolet curable resin.

[0322] (Variant 2)

[0323] A configuration similar to that of Modification 2 in the first embodiment can be applied to the recording medium 10A according to the second embodiment.

[0324] (Variant 3)

[0325] A configuration similar to that of Modification 3 in the first embodiment can be applied to the recording medium 10A according to the second embodiment.

[0326] (Variant 4)

[0327] A configuration similar to that of Modification 4 in the first embodiment can be applied to the recording medium 10A according to the second embodiment.

[0328] (Variant 5)

[0329] The resin layer may be provided between the pressure-sensitive adhesive layer 12A and the recording layer 13A. Similar to the resin layer 14A1 and the resin layer 14B1, the resin layer desirably contains an ultraviolet curable resin and a polycarbonate resin. Examples of the ultraviolet curable resin and the polycarbonate resin include materials similar to those of the resin layer 14A1 and the resin layer 14B1.

[0330] <3 Application Examples>

[0331] The recording medium 10 according to the first embodiment and its variants and the recording medium 10A according to the second embodiment and its variants can be applied to cards, medical items, automotive parts, cars, toys, food, cosmetics, clothes, documents (e.g., passports), external components, or housings of electronic devices, etc. For example, specific embodiments of external components include the interior or exterior of a wall of a building, the exterior of furniture such as a table, etc. Specific embodiments of electronic devices include personal computers (hereinafter referred to as "PCs"), mobile devices, mobile phones (e.g., smart phones), tablet computers, display devices, imaging devices, audio devices, gaming devices, industrial equipment, medical devices, robots, wearable terminals, etc. Specific embodiments of wearable terminals include clothing such as watches (watches), bags, clothes, hats, glasses, and shoes.

[0332] Hereinafter, specific embodiments in which the recording medium 10 or 10A is applied to a card, a booklet, a smartphone, a notebook personal computer, and a cosmetic container will be described.

[0333] <3-1 Application Example 1>

[0334] In Application Example 1, an example of a card provided with the recording medium 10 according to the first embodiment will be described.

[0335] [Card Configuration]

[0336] In the following, reference will be made to Figure 5 A and Figure 5 B describes an example of a configuration of a card 30 according to Application Example 1. The card 30 includes a base material (card base material) 31 , an adhesive layer 32 , an intermediate layer 33 , an adhesive layer 34 , and a cover layer 35 in this order. The intermediate layer 33 includes the recording medium 10 .

[0337] The card 30 is an embodiment of a laminate. The card 30 is an ID card (e.g., an employee ID card, a membership card, a student ID card, etc.). The ID card is an embodiment of a card type identification. In Application Example 1, an embodiment in which the card 30 is an ID card will be described, but the type of card provided with the recording medium 10 is not limited thereto. The card provided with the recording medium 10 may be, for example, a card such as a security card, a financial payment card (e.g., a credit card, a cash card, etc.), a driver's license, a health insurance card, a basic resident registration card, a personal number card (personal number card), or a personal transaction card (e.g., a prepaid card, a points card, etc.). The card 30 may be a contactless IC card.

[0338] (Substrate 31)

[0339] The substrate 31 may be a support member supporting the intermediate layer 33. The substrate 31 has, for example, a rectangular thin plate shape. The substrate 31 has a first surface (front surface) on which an adhesive layer 32, an intermediate layer 33, an adhesive layer 34, and a cover layer 35 are laminated, and a second surface (rear surface) opposite to the first surface. The substrate 31 may have a color such as white. Patterns, pictures, photos, characters, combinations of two or more thereof, etc. (hereinafter, referred to as "patterns, etc.") may be printed on the first surface of the substrate 31. The substrate 31 may include an integrated circuit (IC) chip, an antenna coil, etc. on the first surface.

[0340] The base material 31 includes, for example, plastic. The base material 31 may include at least one selected from the group consisting of a colorant, an antistatic agent, a flame retardant, a surface modifier, and the like, as necessary.

[0341] For example, the plastic includes at least one selected from the group consisting of ester resins, amide resins, olefin resins, vinyl resins, acrylic resins, imide resins, styrene resins, engineering plastics, etc. In the case where the base material 31 includes two or more resins, the two or more resins may be mixed, copolymerized, or laminated.

[0342] For example, the ester resin includes at least one selected from the group including polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polyethylene naphthalate (PEN) resin, polyethylene terephthalate-isophthalate copolymer resin, terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer resin, etc. For example, the amide resin includes at least one selected from the group including nylon 6 resin, nylon 66 resin, nylon 610 resin, etc. For example, the olefin resin includes at least one selected from the group including polyethylene (PE) resin, polypropylene (PP) resin, polymethylpentene (PMP) resin, etc. The vinyl resin includes, for example, polyvinyl chloride (PVC) resin.

[0343] For example, the acrylic resin includes at least one selected from the group including polyacrylate resin, polymethacrylate resin, polymethyl methacrylate (PMMA) resin, etc. For example, the imide resin includes at least one selected from the group including polyimide (PI) resin, polyamideimide (PAI) resin, polyetherimide (PEI) resin, etc. The styrene resin includes, for example, at least one selected from the group including polystyrene (PS) resin, high impact polystyrene resin, acrylonitrile-styrene resin (AS resin), acrylonitrile-butadiene-styrene resin (ABS resin), etc. The engineering plastic includes, for example, at least one selected from the group including polycarbonate (PC) resin, polyarylate (PAR) resin, polysulfone (PSF) resin, polyethersulfone (PES) resin, polyphenylene ether (PPE) resin, polyphenylene sulfide (PPS) resin, polyetherketone (PEK) resin, polyetheretherketone (PEEK) resin, polyphenylene ether (PPO) resin, polyethersulfite resin, etc.

[0344] (Middle layer 33)

[0345] The intermediate layer 33 is provided between the substrate 31 and the cover layer 35. More specifically, the intermediate layer 33 is provided on the first surface of the substrate 31, and the adhesive layer 32 is sandwiched between the substrate 31 and the intermediate layer 33. The intermediate layer 33 includes a housing portion 33A for housing the recording medium 10. The housing portion 33A is provided in a portion of the plane of the intermediate layer 33. The housing portion 33A may be a through hole penetrating in the thickness direction of the intermediate layer 33. The intermediate layer 33 is used to control the height difference formed by the recording medium 10 when the recording medium 10 is sandwiched between the substrate 31 and the cover layer 35. The intermediate layer 33 has substantially the same thickness as the recording medium 10, and covers the first surface of the substrate 31, rather than the region where the recording medium 10 is provided.

[0346] The intermediate layer 33 has a film shape. The intermediate layer 33 may be transmissive with respect to visible light. The intermediate layer 33 includes plastic. As the plastic, a material similar to that of the substrate 31 can be exemplified.

[0347] (cover layer 35)

[0348] The cover layer 35 is disposed on the intermediate layer 33 and the recording medium 10, and covers the intermediate layer 33 and the recording medium 10. The adhesive layer 34 is sandwiched between the intermediate layer 33 and the recording medium 10 and the cover layer 35. The cover layer 35 protects the internal components of the card 30 (i.e., the recording medium 10 and the intermediate layer 33) and maintains the mechanical reliability of the card 30.

[0349] The cover layer 35 has a film shape. The cover layer 35 is transmissive to visible light. The cover layer 35 contains plastic. As the plastic, a material similar to that of the base material 31 can be exemplified. A pattern or the like can be printed on at least one surface of the cover layer 35.

[0350] (Adhesive layers 32, 34)

[0351] The adhesive layer 32 is provided between the substrate 31 and the intermediate layer 33, and makes the substrate 31 and the intermediate layer 33 adhere to each other. The adhesive layer 34 is provided between the intermediate layer 33 and the cover layer 35, and makes the intermediate layer 33 and the cover layer 35 adhere to each other. The adhesive layers 32 and 34 have transparency. The adhesive layers 32 and 34 preferably contain a thermosetting adhesive. The thermosetting adhesive contains, for example, a thermosetting resin. The thermosetting resin includes, for example, at least one selected from the group including epoxy resin, polyurethane resin, etc. From the viewpoint of reducing damage to the recording medium 10, the curing temperature of the thermal adhesive is preferably in a temperature range of 100° C. or more and 120° C. or less.

[0352] (Combination of Materials of Base Material 31, Intermediate Layer 33 and Covering Layer 35)

[0353] From the viewpoint of improving adhesion, it is preferred that the substrate 31, the intermediate layer 33 and the covering layer 35 contain the same type of resin material. The resin material may be a thermoplastic resin. From the viewpoint of environmental considerations, it is preferred that the substrate 31, the intermediate layer 33 and the covering layer 35 contain polycarbonate (PC) resin or polyethylene terephthalate (PET) resin. From the viewpoint of improving durability, it is preferred that the substrate 31, the intermediate layer 33 and the covering layer 35 contain polycarbonate (PC) resin or polyvinyl chloride (PVC) resin. From the viewpoint of improving adhesion, environmental considerations and durability, the substrate 31, the intermediate layer 33 and the covering layer 35 preferably contain polycarbonate (PC) resin.

[0354] For example, it can be confirmed as follows: the base material 31, the intermediate layer 33, and the cover layer 35 contain the same type of resin material. First, the base material 31, the intermediate layer 33, and the cover layer 35 are taken out from the card 30. Next, the IR spectra of the base material 31, the intermediate layer 33, and the cover layer 35 are obtained by infrared absorption spectroscopy (IR). Next, by comparing the obtained IR spectra of each layer, it is confirmed that the same type of resin material is contained in the base material 31, the intermediate layer 33, and the cover layer 35.

[0355] Furthermore, the type of the resin material contained in each of the base material 31 , the intermediate layer 33 , and the cover layer 35 can be confirmed using the obtained IR spectrum of each layer.

[0356] (Recording Medium 10)

[0357] The recording medium 10 is disposed between the base material 31 and the cover layer 35. The recording medium 10 is accommodated in the accommodation portion 33A in such a manner that the base material 11 of the recording medium 10 faces the base material 31. A facial photo or the like may be drawn on the recording medium 10. However, the information drawn on the recording medium 10 is not limited to the facial photo, and may be ID information for security or the like.

[0358] The recording medium 10 has a first surface facing the cover layer 35 and a second surface facing the substrate 31. From the viewpoint of improving adhesion, it is preferred that the first surface and / or the second surface of the recording medium 10 be subjected to an easy adhesion treatment such as a plasma treatment. In this specification, the term "and / or" means "at least one", and for example, in the case where the term is used in the phrase "X and / or Y", the phrase means three cases of "only X", "only Y", and "X and Y".

[0359] [Card manufacturing method]

[0360] Hereinafter, an embodiment of a method of manufacturing the card 30 according to Application Example 1 will be described.

[0361] First, a thermosetting resin as a thermosetting adhesive is applied to the first surface of the substrate 31 to form the adhesive layer 32. Next, after the intermediate layer 33 is placed on the adhesive layer 32, the recording medium 10 is installed in the housing portion 33A of the intermediate layer 33. It should be noted that the intermediate layer 33 in which the recording medium 10 is pre-assembled in the housing portion 33A may be placed on the adhesive layer 32. Conversely, the adhesive layer 32 may be formed by applying a thermosetting resin to the intermediate layer 33 in which the recording medium 10 is pre-assembled in the housing portion 33A, and then placing the intermediate layer 33 on the first surface of the substrate 31 so as to sandwich the coating layer between the intermediate layer 33 and the intermediate layer 33. Alternatively, the adhesive layer 32 may be formed by bonding a sheet formed by pre-applying a thermosetting resin to a diaphragm or the like to the first surface of the substrate 31 or the intermediate layer 33 by means such as thermal lamination, the recording medium 10 being pre-assembled in the housing portion 33A.

[0362] Next, a thermosetting resin as a thermosetting adhesive is applied to the intermediate layer 33 to form an adhesive layer 34, and then a cover layer 35 is placed on the adhesive layer 34. Next, the obtained laminate is sandwiched between metal plates, and pressurized while heating, so that the adhesive layer 32 and the adhesive layer 34 are thermally cured. From the viewpoint of reducing damage to the recording medium 10, the temperature applied to the laminate during thermal curing is preferably 100° C. or more and 120° C. or less. Thus, the target card 30 is obtained. The adhesive layer 34 can be formed by applying a thermosetting resin to the cover layer 35 and then placing the cover layer 35 on the intermediate layer 33 to sandwich the coating layer between the cover layer 35 and the intermediate layer 33. In addition, the adhesive layer 34 can be formed by bonding a sheet formed by applying a thermosetting resin in advance to a diaphragm or the like to the cover layer 35 or the intermediate layer 33 using thermal lamination or the like.

[0363] [Operation and Effect]

[0364] As described above, in the card 30 according to Application Example 1, the base material 31 and the intermediate layer 33 are preferably bonded together by the adhesive layer 32 containing a thermosetting adhesive, and the intermediate layer 33 and the cover layer 35 are preferably bonded together by the adhesive layer 32 containing a thermosetting adhesive. With this configuration, the base material 31 and the intermediate layer 33, and the intermediate layer 33 and the cover layer 35 can be firmly adhered to each other. Therefore, tampering can be more reliably prevented.

[0365] Since the recording medium 10 is fitted in the accommodation portion 33A of the intermediate layer 33, it is possible to make it difficult to visually recognize the boundary between the recording medium 10 and the intermediate layer 33 in the in-plane direction of the card 30. Thus, it is difficult to recognize the portion where the recording medium 10 is provided in the plane of the card 30. Therefore, tampering can be prevented more reliably.

[0366] Since the recording medium 10 is sealed inside the card 30 , the influence of moisture on the recording medium 10 can be reduced.

[0367] [Modifications]

[0368] (Variant 1)

[0369] In Application Example 1, an embodiment has been described in which the accommodation portion 33A is a through hole penetrating in the thickness direction of the intermediate layer 33, but the accommodation portion 33A may be a bottomed groove recessed in the thickness direction of the intermediate layer 33, such as Figure 6 In this case, among the two main surfaces of the intermediate layer 33 , the recessed portion may be provided on the main surface facing the cover layer 35 or on the main surface facing the base material 31 .

[0370] (Variant 2)

[0371] In Application Example 1, an embodiment has been described in which the card 30 includes the recording medium 10 in a partial area of ​​the first surface of the substrate 31. Figure 7 As shown, the card 30 may include the recording medium 10 in substantially the entire area of ​​the first surface of the substrate 31. Specifically, the card 30 may include the recording medium 10 having substantially the same size as the substrate 31 between the adhesive layer 32 and the adhesive layer 34.

[0372] (Variant 3)

[0373] In Application Example 1, an embodiment in which the card 30 includes the intermediate layer 33 has been described, but Figure 8 A and Figure 8 As shown in FIG. 1B , the card 30 may include an intermediate layer 36 instead of the intermediate layer 33. The intermediate layer 36 may protect the side surface of the recording medium 10. The intermediate layer 36 surrounds the peripheral edge portion of one main surface of the substrate 31. The intermediate layer 36 has a frame shape in a plan view. In this specification, the peripheral portion of the one main surface refers to an area having a predetermined width from the peripheral edge of the one main surface toward the inside. In addition, in this specification, a plan view refers to a plan view when an object is observed from a direction perpendicular to one main surface of the substrate 31.

[0374] The intermediate layer 36 includes a housing portion 36A. The recording medium 10 is housed in the housing portion 36A. The housing portion 36A is a through hole that penetrates in the thickness direction of the recording medium 10. The intermediate layer 36 and the recording medium 10 preferably have substantially the same thickness. Therefore, in a state where the recording medium 10 is subjected to the housing portion 36A, a difference in level at the boundary between the intermediate layer 36 and the recording medium 10 can be suppressed.

[0375] The intermediate layer 36 has a film shape. The intermediate layer 36 may have transparency. The intermediate layer 36 contains plastic. As the plastic, a material similar to that of the substrate 31 can be exemplified.

[0376] (Variant 4)

[0377] In Application Example 1, an example has been described in which the card 30 includes the recording medium 10 according to the first embodiment. However, the card 30 may include the recording medium 10 according to any one of Modifications 1 to 4 of the first embodiment, or may include the recording medium 10A according to the second embodiment or the recording medium 10A according to any one of Modifications 1 to 4 of the second embodiment.

[0378] <3-2 Application Example 2>

[0379] In Application Example 2, an embodiment of a card having a configuration different from that of Application Example 1 will be described.

[0380] [Card Configuration]

[0381] In the following, reference will be made to Fig. 9 An example of a configuration of a card 30A according to Application Example 2 is described. Card 30A is different from card 30 according to Application Example 1 in that card 30A does not include adhesive layer 32 and adhesive layer 34, and in that base material 31 and intermediate layer 33, and intermediate layer 33 and cover layer 35 are bonded by fusion.

[0382] In Application Example 2, it is preferred that the base material 31, the intermediate layer 33, and the cover layer 35 contain a thermoplastic resin as the plastic. With the base material 31, the intermediate layer 33, and the cover layer 35 containing a thermoplastic resin, the interlayer adhesion strength by fusion can be improved. From the viewpoint of reducing damage to the recording medium 10, the thermoplastic resin is preferably capable of thermally fusing the layers of the card 30A together within a temperature range of 130° C. or higher and 200° C. or lower.

[0383] The substrate 31, the intermediate layer 33, and the cover layer 35 may contain the same type of thermoplastic resin, but the substrate 31, the intermediate layer 33, and the cover layer 35 do not necessarily need to contain the same type of thermoplastic resin. In the case where the substrate 31, the intermediate layer 33, and the cover layer 35 do not contain the same type of thermoplastic resin, one of the substrate 31, the intermediate layer 33, and the cover layer 35 may contain a thermoplastic resin of a different type from the other two layers, and the substrate 31, the intermediate layer 33, and the cover layer 35 may contain thermoplastic resins of different types from each other.

[0384] In the case where the base material 31, the intermediate layer 33 and the cover layer 35 contain the same type of thermoplastic resin, from the viewpoint of improving interlayer adhesive strength by fusion, it is preferred that the base material 31, the intermediate layer 33 and the cover layer 35 contain at least one selected from the group consisting of semi-crystalline thermoplastic resins and amorphous thermoplastic resins.

[0385] For example, the semi-crystalline thermoplastic resin includes at least one selected from the group consisting of polypropylene (PP) resin, polyethylene (PE) resin, polyacetal (POM) resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polyphenylene sulfide (PPS) resin, polyetheretherketone (PEEK) resin, etc.

[0386] For example, the amorphous thermoplastic resin includes at least one selected from the group consisting of ABS resin, polycarbonate (PC) resin, polymer alloy of ABS resin and PC resin (hereinafter, referred to as "ABS / PC polymer alloy"), AS resin, polystyrene (PS) resin, polymethyl methacrylate (PMMA) resin, polyphenylene ether (PPO) resin, polysulfone (PSU) resin, polyvinyl chloride (PVC) resin, polyetherimide (PEI) resin, polyethersulfone (PES) resin, etc.

[0387] In the case where the base material 31 , the intermediate layer 33 , and the cover layer 35 do not contain the same type of thermoplastic resin, it is preferred that the base material 31 , the intermediate layer 33 , and the cover layer 35 contain a non-crystalline thermoplastic resin from the viewpoint of improving interlayer adhesive strength by fusion.

[0388] The combination of non-crystalline thermoplastic resins separately contained in two adjacent layers of the card 30A is preferably as follows: In the case where one of the two adjacent layers of the card 30A contains ABS resin, the other layer preferably contains at least one selected from the group consisting of ABS / PC polymer alloy resin, polycarbonate (PC) resin, AS resin, polystyrene (PS) resin, polymethyl methacrylate (PMMA) resin, and polyvinyl chloride (PVC) resin.

[0389] In the case where one of the two adjacent layers of the card 30A includes an ABS / PC polymer alloy, the other layer preferably includes at least one selected from the group consisting of ABS resin, polycarbonate (PC) resin, and polymethyl methacrylate (PMMA) resin. In the case where one of the two adjacent layers of the card 30A includes a polycarbonate (PC) resin, the other layer preferably includes at least one selected from the group consisting of ABS resin, ABS / PC polymer alloy resin, and polymethyl methacrylate (PMMA) resin.

[0390] When one of the two adjacent layers of the card 30A contains AS resin, the other preferably contains at least one selected from ABS resin, polystyrene (PS) resin, polymethyl methacrylate (PMMA) resin, and polyphenylene ether (PPO) resin. When one of the two adjacent layers of the card 30A contains polystyrene (PS) resin, the other preferably contains at least one layer selected from the group consisting of AS resin and polyphenylene ether (PPO) resin.

[0391] In the case where one of the two adjacent layers of the card 30A contains polymethyl methacrylate (PMMA) resin, the other layer preferably contains at least one selected from the group consisting of ABS resin, ABS / PC polymer alloy resin, AS resin, and polyphenylene oxide (PPO) resin. In the case where one of the two adjacent layers of the card 30A contains polyphenylene oxide (PPO) resin, the other layer preferably contains at least one selected from the group consisting of polycarbonate (PC) resin, AS resin, polystyrene (PS) resin, and polymethyl methacrylate (PMMA) resin.

[0392] In the case where one of the two adjacent layers of the card 30A contains polysulfone (PSU) resin, the other layer preferably contains polycarbonate (PC) resin. In the case where one of the two adjacent layers of the card 30A contains polyvinyl chloride (PVC) resin, the other layer preferably contains ABS resin.

[0393] [Card manufacturing method]

[0394] Hereinafter, an embodiment of a method of manufacturing the card 30A according to Application Example 2 will be described.

[0395] First, after placing the intermediate layer 33 on the first surface of the substrate 31, the recording medium 10 is installed in the accommodating portion 33A of the intermediate layer 33. It should be noted that the intermediate layer 33 in which the recording medium 10 is pre-assembled in the accommodating portion 33A may be placed on the first surface of the substrate 31. Next, the cover layer 35 is placed on the intermediate layer 33. Next, the obtained laminate is sandwiched between metal plates and pressurized while heating, so that the substrate 31 and the intermediate layer 33 are thermally fused together, and the intermediate layer 33 and the cover layer 35 are thermally fused together. From the viewpoint of reducing damage to the recording medium 10 and the viewpoint of showing sufficient melting strength, the temperature applied to the laminate at the time of thermal fusion is preferably 110° C. or more and 200° C. or less. Thus, the target card 30A is obtained.

[0396] [Operation and Effect]

[0397] As described above, in the card 30A according to Application Example 2, the base material 31 and the intermediate layer 33, and the intermediate layer 33 and the cover layer 35 are fused. With this configuration, the base material 31 and the intermediate layer 33, and the intermediate layer 33 and the cover layer 35 can be firmly bonded. Therefore, tampering can be more reliably prevented.

[0398] [Modifications]

[0399] (Variant 1)

[0400] In Application Example 2, an embodiment has been described in which the accommodation portion 33A is a through hole penetrating in the thickness direction of the intermediate layer 33, but the accommodation portion 33A may be a bottomed groove recessed in the thickness direction of the intermediate layer 33, such as Fig.10 In this case, among the two main surfaces of the intermediate layer 33 , the recessed portion may be provided on the main surface facing the cover layer 35 or on the main surface facing the substrate 31 .

[0401] (Variant 2)

[0402] In Application Example 2, an embodiment has been described in which the card 30A includes the recording medium 10 in a partial area of ​​the first surface of the substrate 31. Fig.11 As shown, the card 30A may include the recording medium 10 in substantially the entire area of ​​the first surface of the substrate 31. Specifically, the card 30A may include the recording medium 10 having substantially the same size as the substrate 31 between the substrate 31 and the cover layer 35.

[0403] (Variant 3)

[0404] In Application Example 2, an embodiment in which the card 30A includes the intermediate layer 33 has been described, but Fig.12 As shown in FIG. 1 , the card 30A may include an intermediate layer 36 instead of the intermediate layer 13. The intermediate layer 36 is as described in the modification example 3 of the application example 1.

[0405] (Variant 4)

[0406] In Application Example 2, an example has been described in which the card 30A includes the recording medium 10 according to the first embodiment. However, the card 30 may include the recording medium 10 according to any one of Modifications 1 to 4 of the first embodiment, or may include the recording medium 10A according to the second embodiment or the recording medium 10A according to any one of Modifications 1 to 4 of the second embodiment.

[0407] <3-3 Application Example 3>

[0408] In Application Example 3, an example of a booklet provided with the recording medium 10 according to the first embodiment will be described.

[0409] [Booklet Configuration]

[0410] Fig.13 : is a cross-sectional view showing an embodiment of the configuration of a booklet 40 according to Application Example 3. The booklet 40 is a passport. The passport is an embodiment of a booklet type identification. The booklet 40 includes a plurality of sheets 41. The plurality of sheets 41 are saddle-stitched. The recording medium 10 is provided on a portion of one surface or both surfaces of the sheet 41. A facial photograph or the like is drawn on the recording medium 10. The sheet 41 may have a layer configuration similar to that of the card 30 according to Application Example 1 or the card 30A of Application Example 2. In this case, the base material 31 may be paper or the like.

[0411] [Modifications]

[0412] (Variant 1)

[0413] In Application Example 3, an embodiment has been described in which the booklet 40 includes the recording medium 10 in a partial area of ​​one surface or both surfaces of the sheet 41, but the booklet 40 may include the recording medium 10 in substantially the entire area of ​​one surface or both surfaces of the sheet 41. Specifically, the booklet 40 may include the recording medium 10 having substantially the same size as the sheet 41 on one surface or both surfaces.

[0414] (Variant 2)

[0415] In Application Example 3, an example has been described in which the booklet 40 includes the recording medium 10 according to the first embodiment. However, the booklet 40 may include the recording medium 10 according to any one of Modifications 1 to 4 of the first embodiment, or may include the recording medium 10A according to the second embodiment or the recording medium 10A according to any one of Modifications 1 to 4 of the second embodiment.

[0416] <3-4 Application Example 4>

[0417] In Application Example 4, an example of a smartphone provided with the recording medium 10 according to the first embodiment will be described.

[0418] [Smartphone configuration]

[0419] Fig.14 A is a plan view showing an example of the external appearance on the front side of a smartphone according to Application Example 4. FIG. Fig.14B is a plan view of the appearance on the back of the smartphone according to Application Example 4. For example, the smartphone 100 includes a display unit 111 and a housing 112. The recording medium 10 is provided on the back of the housing 112. The housing 112 is formed of a laminate. The laminate may have a layer configuration similar to that of the card 30 according to Application Example 1 or the card 30A according to Application Example 2, except that the base material has the housing shape of the smartphone 100. In this case, the anti-counterfeiting of the smartphone 100 can be improved, etc.

[0420] [Modifications]

[0421] In Application Example 4, an example has been described in which the smartphone 100 includes the recording medium 10 according to the first embodiment. However, the smartphone 100 may include the recording medium 10 according to any one of Modifications 1 to 4 of the first embodiment, or may include the recording medium 10A according to the second embodiment or the recording medium 10A according to any one of Modifications 1 to 4 of the second embodiment.

[0422] <3-5 Application Example 5>

[0423] In Application Example 5, an example of a notebook PC provided with the recording medium 10 according to the first embodiment will be described.

[0424] [Notebook PC configuration]

[0425] Fig.15 2 is a cross-sectional view showing an embodiment of the appearance of a notebook personal computer according to Application Example 5. The notebook PC 200 includes a computer body 210 and a display 220. The computer body 210 includes a housing 211, a keyboard 212, a wheel / pad operation unit 213, and click buttons 214 and 215. The recording medium 10 is set in the housing 112. The housing 211 is formed of a laminate. In addition to the base material having the outer shell shape of the notebook PC 200, the laminate may have a layer configuration similar to that of the card 30 according to Application Example 1 or the card 30A according to Application Example 2. In this case, the anti-counterfeiting and the like of the notebook PC 200 can be improved.

[0426] [Modifications]

[0427] In Application Example 5, an example has been described in which the notebook PC 200 includes the recording medium 10 according to the first embodiment. However, the notebook PC 200 may include the recording medium 10 according to any one of Modifications 1 to 4 of the first embodiment, or may include the recording medium 10A according to the second embodiment or the recording medium 10A according to any one of Modifications 1 to 4 of the second embodiment.

[0428] <3-6 Application Example 6>

[0429] In Application Example 6, an example of a cosmetic container provided with the recording medium 10 according to the first embodiment will be described.

[0430] [Configuration of cosmetic containers]

[0431] Fig.16 3 is a cross-sectional view showing an embodiment of the appearance of a cosmetic container according to Application Example 6. The cosmetic container 300 includes a housing portion 311 and a cover 312 covering the housing portion 311. The recording medium 10 is disposed in the cover 312. The cover 312 is formed of a laminate. The laminate may have a layer configuration similar to that of the card 30 according to Application Example 1 or the card 30A according to Application Example 2, except that the base material has a shape corresponding to the cover 312. In this case, anti-counterfeiting and the like of the cosmetic container 300 can be improved.

[0432] [Modifications]

[0433] In Application Example 6, an example in which the cosmetic container 300 includes the recording medium 10 of the first embodiment is described. However, the cosmetic container 300 may include the recording medium 10 according to any one of Modifications 1 to 4 of the first embodiment, or may include the recording medium 10A according to the second embodiment or the recording medium 10A according to any one of Modifications 1 to 4 of the second embodiment.

[0434] The embodiments of the present disclosure and the modifications thereof have been specifically described above, but the present disclosure is not limited to the above-mentioned embodiments and the modifications thereof, and various modifications based on the technical idea of ​​the present disclosure are possible.

[0435] For example, the configurations, methods, processes, shapes, materials, numerical values, etc. described in the above-mentioned embodiments and modified examples are merely examples, and different configurations, methods, processes, shapes, materials, numerical values, etc. may be used as needed. The configurations, methods, steps, shapes, materials, numerical values, etc. of the above-mentioned embodiments and modified examples may be combined with each other without departing from the gist of the present disclosure.

[0436] In the numerical ranges described in the stages in the above embodiments and modifications, the upper limit or lower limit of the numerical range of a certain stage can be replaced by the upper limit or lower limit of the numerical range of another stage. The materials exemplified in the above embodiments and modifications can be used alone or in combination of two or more, unless otherwise specified.

[0437] Furthermore, the present disclosure may also adopt the following configurations. (1)

[0439] A recording medium comprising:

[0440] two or more recording layers; and

[0441] One or more resin layers, wherein

[0442] Each recording layer comprises a first polycarbonate resin;

[0443] Each resin layer is disposed between two recording layers, and

[0444] Each resin layer contains an ultraviolet curable resin and a second polycarbonate resin. (2)

[0446] The recording medium according to (1), wherein

[0447] Each recording layer contains a coloring compound having an electron donating property and a developer having an electron accepting property. (3)

[0449] The recording medium according to (1) or (2), wherein:

[0450] Each recording layer is capable of changing its coloration state by external stimulation. (4)

[0452] The recording medium according to (3), wherein

[0453] The external excitation is a laser. (5)

[0455] The recording medium according to (3) or (4), wherein:

[0456] The change of coloring state is irreversible. (6)

[0458] The recording medium according to any one of (1) to (5), wherein

[0459] The content of the second polycarbonate resin in each resin layer is 15% by mass or more and 33% by mass or less. (7)

[0461] The recording medium according to any one of (1) to (5), wherein

[0462] The content of the second polycarbonate resin in each resin layer is 20% by mass or more and 25% by mass or less. (8)

[0464] The recording medium according to any one of (1) to (7), wherein

[0465] The content of the ultraviolet curable resin in each resin layer is 60% by mass or more and 80% by mass or less. (9)

[0467] The recording medium according to any one of (1) to (8), wherein

[0468] The second polycarbonate resin has at least one ultraviolet reactive group. (10)

[0470] The recording medium according to any one of (1) to (8), wherein

[0471] The second polycarbonate resin has at least one group including an ethylenically unsaturated bond. (11)

[0473] The recording medium according to (10), wherein

[0474] The at least one group including an ethylenically unsaturated bond includes at least one selected from the group consisting of a vinyl group, an acryloyl group, and a methacryloyl group. (12)

[0476] The recording medium according to any one of (1) to (11), wherein

[0477] Each resin layer has solubility in methyl ethyl ketone. (13)

[0479] The recording medium according to any one of (1) to (12), further comprising:

[0480] One or more pressure-sensitive adhesive layers, wherein

[0481] Each pressure-sensitive adhesive layer is provided between two recording layers together with each resin layer. (14)

[0483] The recording medium according to any one of (1) to (13), wherein

[0484] Each resin layer is adjacent to at least one of the two recording layers, and

[0485] The average peel strength between the resin layer and the recording layer adjacent to the resin layer is 3.5 N / cm or more; (15)

[0487] A laminate comprising:

[0488] Base material;

[0489] An intermediate layer, disposed on the substrate and having a receiving portion;

[0490] a recording medium disposed in the housing; and

[0491] A cover layer is disposed on the middle layer, wherein

[0492] The receiving portion is arranged in a planar portion of the intermediate layer,

[0493] The receiving portion is a through hole penetrating in the thickness direction of the intermediate layer or a recessed portion recessed in the thickness direction of the intermediate layer.

[0494] The substrate, the intermediate layer and the cover layer comprise the same kind of resin material,

[0495] The base material and the intermediate layer are bonded to each other by fusion, and the intermediate layer and the cover layer are bonded to each other by fusion, and

[0496] The recording medium is the recording medium according to any one of (1) to (14). (16)

[0498] A laminate comprising:

[0499] Base material;

[0500] Covering layer;

[0501] an intermediate layer disposed between the substrate and the cover layer and having a receiving portion; and

[0502] The recording medium is arranged in the receiving portion, wherein

[0503] The receiving portion is arranged in a planar portion of the intermediate layer,

[0504] The receiving portion is a through hole penetrating in the thickness direction of the intermediate layer or a recessed portion recessed in the thickness direction of the intermediate layer.

[0505] The substrate, the intermediate layer and the cover layer comprise the same kind of resin material,

[0506] The base material and the intermediate layer are bonded to each other by a thermal adhesive, and the intermediate layer and the cover layer are bonded to each other by a thermal adhesive, and

[0507] The recording medium is the recording medium according to any one of (1) to (14). (17)

[0509] The laminate according to (15) or (16), wherein

[0510] The resin material includes a thermoplastic resin. (18)

[0512] The laminate according to (15) or (16), wherein

[0513] The resin material includes polycarbonate resin or polyethylene terephthalate resin. (19)

[0515] A recording medium comprising:

[0516] two or more recording layers; and

[0517] One or more resin layers, wherein

[0518] Each recording layer comprises a first thermoplastic resin,

[0519] Each resin layer is disposed between two recording layers, and

[0520] Each resin layer contains an ultraviolet curable resin and a second thermoplastic resin of the same type as the first thermoplastic resin. (20)

[0522] The recording medium according to (19), wherein

[0523] Each recording layer contains a coloring compound having an electron donating property and a developer having an electron accepting property.

[0524] <4 Embodiment>

[0525] Hereinafter, the present disclosure will be described in detail with reference to Examples, but the present disclosure is not limited to these Examples.

[0526] [Examples 1 to 6]

[0527] The configurations of the recording media of Examples 1 to 6 are as follows. Note that the order of description of the layers below corresponds to the lamination order of the layers.

[0528] Cover layer: PC film, thickness 25μm

[0529] Fifth pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0530] UV cutting layer: thickness 10μm

[0531] Fourth resin layer: UV curable resin layer (hard coat layer (hereinafter, referred to as "HC layer")), thickness 3 μm

[0532] Fourth pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0533] Third resin layer: a resin layer containing ultraviolet curable resin and polycarbonate, with a thickness of 3 μm

[0534] The third recording layer: a yellow recording layer in the color development state, with a thickness of 5 μm

[0535] Third pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0536] Second resin layer: A resin layer containing ultraviolet curable resin and polycarbonate, with a thickness of 3 μm

[0537] Second recording layer: a recording layer that appears cyan in the color development state, with a thickness of 5 μm

[0538] Second pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0539] First resin layer: A resin layer containing ultraviolet curing resin and polycarbonate, with a thickness of 3 μm

[0540] First recording layer: a recording layer that appears magenta in the color development state, with a thickness of 5 μm

[0541] First pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0542] Base film: PC film, thickness 25μm

[0543] A recording medium having the above-mentioned layer configuration was prepared as follows.

[0544] (Step of forming a first laminate film)

[0545] First, polycarbonate (PC) as a matrix resin is dissolved in methyl ethyl ketone (MEK), a developer is further added, and dispersed using a shaker. As a developer, a bis(hydroxybenzoic acid) compound is used. Next, a colorless dye that exhibits a magenta color in a color-developed state is added, and the ratio (mass ratio) of the colorless dye, the developer, and the polycarbonate is prepared to finally obtain 1:2:4. In addition, a photothermal conversion agent having an absorption wavelength peak at a wavelength λ1 and having a phthalocyanine skeleton is added to prepare a first recording layer forming coating material.

[0546] Next, polycarbonate and an ultraviolet curable acrylic resin for forming an HC layer are mixed to prepare a first resin layer forming coating. As polycarbonate, a polycarbonate having a methacryloyl group is used. As shown in Table 1, for each of Examples 1 to 6, the mixing ratio of polycarbonate and the ultraviolet curable acrylic resin is adjusted to a different value. Subsequently, the first resin layer forming coating is applied to a flat surface, and then the first resin layer forming coating is irradiated with ultraviolet rays and cured to form a first resin layer. Next, the first recording layer forming coating is applied to the first resin layer by a gravure application method, and dried and cured to form a first recording layer. In this way, a first laminated film including a first resin layer and a first recording layer is obtained.

[0547] (Step of forming a second laminate film)

[0548] A leuco dye that exhibits cyan in a color-developed state is used as a leuco dye, and a photothermal conversion agent having an absorption wavelength peak at wavelength λ2 and having a phthalocyanine skeleton is used as a photothermal conversion agent. In addition to the above, similar to the steps of forming the first laminated film (except these), a second laminated film including a second resin layer and a second recording layer is obtained.

[0549] (Step of forming the third laminate film)

[0550] A leuco dye that exhibits yellow in a color-developed state is used as a leuco dye, and a photothermal conversion agent having an absorption wavelength peak at wavelength λ3 and having a phthalocyanine skeleton is used as a photothermal conversion agent. In addition to the above, similar to the steps of forming the first laminated film (except these), a third laminated film including a third resin layer and a third recording layer is obtained. Note that the wavelengths λ1, λ2, and λ3 are selected to have different values.

[0551] (Step of forming the fourth laminate film)

[0552] The cover layer (PC film), the fifth pressure-sensitive adhesive layer (OCA), the UV cutting layer, and the fourth resin layer (HC layer) were laminated in this order to obtain a fourth laminated film.

[0553] (Lamination Step)

[0554] The fourth laminating film, the fourth pressure-sensitive adhesive layer (OCA), the third laminating film, the third pressure-sensitive adhesive layer (OCA), the second laminating film, the second pressure-sensitive adhesive layer (OCA), the first laminating film, the first pressure-sensitive adhesive layer (OCA) and the substrate film (PC film) are laminated in sequence. As a result, the target recording medium is obtained.

[0555] [Example 7]

[0556] The configuration of the recording medium of Example 7 is as follows. Note that the order of description of the layers below corresponds to the lamination order of the layers.

[0557] Cover layer: PC film, thickness 25μm

[0558] Fourth pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0559] UV cutting layer: thickness 10μm

[0560] Third resin layer: UV curable resin layer (HC layer), thickness 3 μm

[0561] Third pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0562] The third recording layer: a yellow recording layer in the color development state, with a thickness of 5 μm

[0563] Second resin layer: A resin layer containing ultraviolet curable resin and polycarbonate, with a thickness of 3 μm

[0564] Second pressure-sensitive adhesive layer: OCA, thickness 15 μm

[0565] Second recording layer: a recording layer that appears cyan in the color development state, with a thickness of 5 μm

[0566] First resin layer: A resin layer containing ultraviolet curing resin and polycarbonate, with a thickness of 3 μm

[0567] First pressure-sensitive adhesive layer: OCA, thickness 15 μm

[0568] First recording layer: a recording layer that appears magenta in the color development state, with a thickness of 5 μm

[0569] A recording medium having the above-mentioned layer configuration was prepared as follows.

[0570] (Step of Forming First Recording Layer)

[0571] The first recording layer forming coating material was prepared similarly to the preparation steps of the first recording layer forming coating material in Example 1. Next, the first recording layer forming coating material was applied onto a flat surface by a gravure application method, and dried and cured to form a first recording layer.

[0572] (Step of forming a first laminate film)

[0573] Similar to the step of forming the second laminated film in Example 5, a first laminated film including the first resin layer and the second recording layer was obtained.

[0574] (Step of forming a second laminate film)

[0575] Similar to the step of forming the third laminated film in Example 5, a second laminated film including the second resin layer and the third recording layer was obtained.

[0576] (Step of forming the third laminate film)

[0577] A third laminate film was obtained similarly to the step of forming the fourth laminate film in Example 1.

[0578] (Lamination Step)

[0579] The third laminating film, the third pressure-sensitive adhesive layer (OCA), the second laminating film, the second pressure-sensitive adhesive layer (OCA), the first laminating film, the first pressure-sensitive adhesive layer (OCA), and the first recording layer are laminated in this order. As a result, a target recording medium is obtained.

[0580] [Comparative Example 1]

[0581] The configuration of the recording medium of Comparative Example 1 is as follows. Note that the order of description of the layers below corresponds to the lamination order of the layers.

[0582] Cover layer: PC film, thickness 25μm

[0583] Fifth pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0584] UV cutting layer: thickness 10μm

[0585] Fourth resin layer: UV curing resin layer (HC layer), thickness 3μm

[0586] Fourth pressure-sensitive adhesive layer: OCA, 6 μm

[0587] Third resin layer: UV curable resin layer (HC layer), thickness 3 μm

[0588] The third recording layer: a yellow recording layer in the color development state, with a thickness of 5 μm

[0589] Third pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0590] Second resin layer: UV curable resin layer (HC layer), thickness 3 μm

[0591] Second recording layer: a recording layer that appears cyan in the color development state, with a thickness of 5 μm

[0592] Second pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0593] First resin layer: UV curable resin layer (HC layer), thickness 3 μm

[0594] First recording layer: a recording layer that appears magenta in the color development state, with a thickness of 5 μm

[0595] First pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0596] Base film: PC film, thickness 25μm

[0597] A recording medium having the above-mentioned layer configuration was prepared as follows. Without mixing polycarbonate, only the ultraviolet curable acrylic resin for forming the HC layer was used as the first resin layer forming coating. Similarly, only the ultraviolet curable acrylic resin for forming the HC layer was used as the second resin layer forming coating, and only the ultraviolet curable acrylic resin for forming the HC layer was used as the third resin layer forming coating. Except for the above, a recording medium was obtained similarly to Example 1.

[0598] [Comparative Example 2]

[0599] The configuration of the recording medium of Comparative Example 2 is as follows. Note that the order of description of the layers below corresponds to the lamination order of the layers.

[0600] Cover layer: PC film, thickness 25μm

[0601] Fifth pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0602] UV cutting layer: thickness 10μm

[0603] Resin layer: UV curing resin layer (HC layer), thickness 3μm

[0604] Fourth pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0605] The third recording layer: a yellow recording layer in the color development state, with a thickness of 5 μm

[0606] Third pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0607] Second recording layer: a recording layer that appears cyan in the color development state, with a thickness of 5 μm

[0608] Second pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0609] First recording layer: a recording layer that appears magenta in the color development state, with a thickness of 5 μm

[0610] First pressure-sensitive adhesive layer: OCA, thickness 6 μm

[0611] Base film: PC film, thickness 25μm

[0612] A recording medium having the above-mentioned layer configuration was prepared as follows.

[0613] (Step of Forming First Recording Layer)

[0614] The first recording layer forming coating material was prepared similarly to the preparation steps of the first recording layer forming coating material in Example 1. Next, the first recording layer forming coating material was applied onto a flat surface by a gravure application method, and dried and cured to form a first recording layer.

[0615] (Step of forming the second recording layer)

[0616] The second recording layer forming coating material was prepared similarly to the preparation steps of the second recording layer forming coating material in Example 1. Next, the second recording layer forming coating material was applied onto a flat surface by a gravure application method, and dried and cured to form a second recording layer.

[0617] (Step of Forming Third Recording Layer)

[0618] The third recording layer forming coating material was prepared similarly to the preparation steps of the third recording layer forming coating material in Example 1. Next, the third recording layer forming coating material was applied onto a flat surface by a gravure application method, and dried and cured to form a third recording layer.

[0619] (Step of forming a first laminate film)

[0620] Similar to the step of forming the fourth laminate film in Example 1, a first laminate film was obtained.

[0621] (Lamination Step)

[0622] The first laminating film, the fourth pressure-sensitive adhesive layer (OCA), the third recording layer, the third pressure-sensitive adhesive layer (OCA), the second recording layer, the second pressure-sensitive adhesive layer (OCA), the first recording layer, the first pressure-sensitive adhesive layer (OCA) and the base film (PC film) are sequentially laminated. As a result, the target recording medium is obtained.

[0623] [Evaluation of recording media]

[0624] The recording medium obtained as described above was evaluated as follows.

[0625] (Attachment)

[0626] First, the average peel strength between the layers of the laminate was measured. The average peel strength was measured by the method for measuring the average peel strength of the laminate described in the first embodiment. Next, the measured average peel strength was evaluated according to the following criteria. Among the average peel strengths between the layers of the laminate, the lowest average peel strength is shown in Table 1. In addition, Fig.17 The relationship between the content of the polycarbonate resin and the average peel strength is shown in FIG.

[0627] ◯: The lowest average peel strength among the average peel strengths between the layers of the laminate is larger than the lowest average peel strength among the average peel strengths between the layers of the laminate of Comparative Example 1.

[0628] ⊙: The average peel strength between the layers is 3.5 N / cm or more.

[0629] When the average peel strength between the layers is 3.5 N / cm or more, it becomes difficult to disassemble the recording medium, and it becomes difficult to tamper with the recording medium.

[0630] (Maximum color rendering OD)

[0631] First, the maximum color development OD of the recording medium was measured using a spectral densitometer (eXact manufactured by X-Rite, Incorporated). Next, the color development property was evaluated according to the following criteria.

[0632] ⊙: The maximum color rendering OD of CMY is above 1.10.

[0633] ◯: The maximum color development ODs of all CMY are 1.00 or more, but at least one of the maximum color development ODs of CMY is less than 1.10.

[0634] ×: At least one of the maximum color development ODs of CMY is less than 1.00.

[0635] An OD value of 1.00, which allows identification of a person when drawing a person, is used as a reference for evaluating ○ and X. When the OD value is less than 1.00, it is difficult to identify a person when drawing a person.

[0636] (Color gamut maintained after heating)

[0637] First, the a of each of the developed part and the undeveloped part in the recording medium before and after heating was measured by using a densitometer (eXact manufactured by X-Rite, Incorporated). * b * , calculate the color gamut. Determine the color gamut retention rate after heating based on the color gamuts before and after heating. Next, evaluate the color gamut retention rate after heating based on the following criteria.

[0638] ×: The color gamut retention rate after heating is 70% or more.

[0639] ○: The color gamut retention rate after heating is less than 70%.

[0640] Note that in the case where the color gamut preservation rate is 70% or more, when drawing a person, the color representation of the person is favorable.

[0641] (Evaluation of Solubility of Resin Layer)

[0642] First, the first resin layer-forming coating material used in Example 4 was applied to a substrate, and then the first resin layer-forming coating material was irradiated with ultraviolet rays and cured to form a first resin layer having a thickness of 3 μm. As a result, Evaluation Sample 1 was obtained.

[0643] Next, Evaluation Samples 2 to 4 were obtained in a similar manner to the preparation method of Evaluation Sample 1, except that the first resin layer-forming coating material used in Examples 5 to 7 was used. Next, Evaluation Sample 5 was obtained in a similar manner to the preparation method of Evaluation Sample 1, except that the first resin layer-forming coating material used in Comparative Example 1 was used.

[0644] Next, a cotton swab impregnated with methyl ethyl ketone was pressed against the surface of the first resin layer of the evaluation samples 1 to 5, and the cotton swab was reciprocated 50 times. Thereafter, the surfaces of the evaluation samples 1 and 2 were visually observed, and the solubility of the first resin layer was evaluated according to the following criteria. The evaluation results are shown in the evaluation result column of Example 5 and Comparative Example 1.

[0645] ○: The substrate surface is exposed.

[0646] ×: The substrate surface is not exposed.

[0647] [Evaluation results]

[0648] [Table 1]

[0649]

[0650] In the evaluation of adhesion, in the recording medium of Comparative Example 1, the interface between the first recording layer and the first resin layer or between the second recording layer and the second resin layer was most easily peeled.

[0651] However, in the recording media of Examples 1 to 6, the interfaces other than the interface between the first recording layer and the first resin layer, the interface between the second recording layer and the second resin layer, and the interface between the third recording layer and the third resin layer are most easily peeled. In addition, in the recording medium of Example 7, the interfaces other than the interface between the first resin layer and the second recording layer and the interface between the second resin layer and the third recording layer are most easily peeled.

[0652] From Table 1 and Fig.17 You can see the following.

[0653] The peel strength of the recording medium (Examples 1 to 7) in which the resin layer adjacent to the recording layer contains polycarbonate and ultraviolet curing resin is higher than the peel strength of the recording medium (Comparative Example 1) in which the resin layer adjacent to the recording layer contains only ultraviolet curing resin. This is believed to be due to the following reasons. That is, the resin layer containing only ultraviolet curing resin has low solubility with methyl ethyl ketone, and does not form a compatible region between the resin layer and the recording layer. On the other hand, the resin layer containing polycarbonate and ultraviolet curing resin has solubility with methyl ethyl ketone, and forms a compatible region between the resin layer and the recording layer.

[0654] In the recording medium (Comparative Example 2) in which only the pressure-sensitive adhesive layer is arranged between the recording layers, the peel strength is high, but the color space retention rate after heating is less than 70%. In the recording medium (Examples 1 to 7) in which the resin layer and the pressure-sensitive adhesive layer are arranged between the recording layers, the peel strength is high, and the color space retention rate after heating is more than 70%. This is considered to be because the diffusion suppression function of the pressure-sensitive adhesive layer is deteriorated by heating in the recording medium (Comparative Example 2) in which only the pressure-sensitive adhesive layer is arranged between the recording layers, while in the recording medium (Examples 1 to 7) in which the resin layer and the pressure-sensitive adhesive layer are arranged between the recording layers, the diffusion suppression function of the resin layer will not deteriorate even after heating.

[0655] From the viewpoint of improving the peel strength, the content of the polycarbonate in the resin layer adjacent to the recording layer is preferably 15% by mass or more, and more preferably 20% by mass or more.

[0656] From the viewpoint of drawing characteristics of humans and the like and color gamut retention after heating, the content of the ultraviolet curable resin in the resin layer adjacent to the recording layer is preferably 60% by mass or more.

[0657] Reference Symbols List

[0658] 10, 10A recording medium

[0659] 11 Base material

[0660] 12A, 12B pressure-sensitive adhesive layer

[0661] 14A, 14B, 14C, 17A, 17B, 17C middle layer

[0662] 14A1, 14B1, 14C1, 14C3 resin layer

[0663] 14A2, 14B2, 14C2 pressure-sensitive adhesive layer

[0664] 13A, 13B, 13C recording layer

[0665] 15UV cutting layer

[0666] 16 Overlay

[0667] 30,30A card

[0668] 32, 34 adhesive layer

[0669] 33,36 middle layer

[0670] 33A, 36A accommodation part

[0671] 35 Overlay

[0672] 40 Booklets

[0673] 41 Sheet

[0674] 100 Smartphone

[0675] 200 Notebook PC

[0676] 300 cosmetic containers.

Claims

1. A recording medium, comprising: two or more recording layers; as well as One or more resin layers, wherein Each of the recording layers comprises a first polycarbonate resin; Each of the resin layers is disposed between two of the recording layers, and Each of the resin layers includes an ultraviolet curable resin and a second polycarbonate resin.

2. The recording medium according to claim 1, wherein Each of the recording layers contains a coloring compound having an electron donating property and a developer having an electron accepting property.

3. The recording medium according to claim 1, wherein Each of the recording layers is capable of changing its coloration state by external stimulation.

4. The recording medium according to claim 3, wherein The external excitation is laser.

5. The recording medium according to claim 3, wherein The change in coloration state is an irreversible change.

6. The recording medium according to claim 1, wherein The content of the second polycarbonate resin in each of the resin layers is 15% by mass or more and 33% by mass or less.

7. The recording medium according to claim 1, wherein The content of the second polycarbonate resin in each of the resin layers is 20% by mass or more and 25% by mass or less.

8. The recording medium according to claim 1, wherein The content of the ultraviolet curable resin in each of the resin layers is 67% by mass or more and 85% by mass or less.

9. The recording medium according to claim 1, wherein The second polycarbonate resin has at least one ultraviolet reactive group.

10. The recording medium according to claim 1, wherein The second polycarbonate resin has at least one group including an ethylenically unsaturated bond.

11. The recording medium according to claim 10, wherein The at least one group including an ethylenically unsaturated bond includes at least one selected from the group consisting of a vinyl group, an acryloyl group, and a methacryloyl group.

12. The recording medium according to claim 1, wherein Each of the resin layers has solubility in methyl ethyl ketone.

13. The recording medium according to claim 1, further comprising: One or more pressure-sensitive adhesive layers, wherein Each of the pressure-sensitive adhesive layers is provided between two of the recording layers together with each of the resin layers.

14. The recording medium according to claim 1, wherein Each of the resin layers is adjacent to at least one of the two recording layers, and An average peel strength between the resin layer and the recording layer adjacent to the resin layer is 3.5 N / cm or more.

15. A laminate comprising: Base material; an intermediate layer, disposed on the substrate and having a receiving portion; a recording medium, disposed in the housing; as well as A covering layer is disposed on the intermediate layer, wherein The receiving portion is arranged in a planar portion of the intermediate layer, The accommodation portion is a through hole penetrating in the thickness direction of the intermediate layer or a recessed portion recessed in the thickness direction of the intermediate layer. The substrate, the intermediate layer and the cover layer include the same kind of resin material, The base material and the intermediate layer are bonded to each other by fusion, and the intermediate layer and the cover layer are bonded to each other by fusion, and The recording medium is the recording medium according to claim 1.

16. A laminate comprising: Base material; Covering layer; An intermediate layer, disposed between the substrate and the cover layer and having a receiving portion; as well as A recording medium is disposed in the housing, wherein: The receiving portion is arranged in a planar portion of the intermediate layer, The accommodation portion is a through hole penetrating in the thickness direction of the intermediate layer or a recessed portion recessed in the thickness direction of the intermediate layer. The base material, the intermediate layer, and the cover layer contain the same kind of resin material, the base material and the intermediate layer are bonded to each other by a thermosetting adhesive, and the intermediate layer and the cover layer are bonded to each other by a thermosetting adhesive, and The recording medium is the recording medium according to claim 1.

17. The laminate according to claim 15, wherein The resin material includes a thermoplastic resin.

18. The laminate according to claim 15, wherein The resin material includes polycarbonate resin or polyethylene terephthalate resin.

19. A recording medium comprising: two or more recording layers; as well as One or more resin layers, wherein Each of said recording layers comprises a first thermoplastic resin, Each of the resin layers is disposed between two recording layers, and Each of the resin layers contains an ultraviolet curable resin and a second thermoplastic resin of the same type as the first thermoplastic resin.

20. The recording medium according to claim 19, wherein Each of the recording layers contains a coloring compound having an electron donating property and a developer having an electron accepting property.

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