Recording medium, layered body, booklet, card, and security document

Abstract

The present invention provides a layered body with which it is possible to improve drawing speed.　The layered body comprises: at least three recording layers each capable of changing the color state thereof to a different color under near infrared laser light; and a diffuse reflection layer (21) disposed below the at least three recording layers. The total light reflectivity of near infrared light having a wavelength of 1080 nm that arrives at the diffuse reflection layer (21) from the at least three recording layers side is at least 93.0%.

Description

Recording media, laminates, booklets, cards and security documents

[0001] The present disclosure relates to a recording medium, a laminate, and a booklet, a card, and a security document including the same.

[0002] In recent years, as a recording medium to replace printed matter, development has been underway of recording media having multiple recording layers whose color development state can be changed by irradiation with infrared laser light. Patent Document 1 discloses a recording medium in which a first recording layer, a second recording layer, and a third recording layer are laminated, and which can exhibit cyan, magenta, and yellow colors, respectively, by irradiation with infrared laser light.

[0003] International Publication No. 2019 / 124003

[0004] However, since the drawing speed of the recording medium is slow, when the recording medium is used for security documents such as booklets (e.g., passports) or cards (e.g., IC cards), it may take a long time to issue the security document.

[0005] An object of the present disclosure is to provide a recording medium, a laminate, and a booklet, card, and security document including the same, which are capable of improving the drawing speed.

[0006] In order to solve the above-mentioned problems, a laminate according to a first aspect of the present disclosure comprises three or more recording layers each capable of changing its color state to a different color by near-infrared laser light, and a diffuse reflective layer provided below the three or more recording layers, and has a total light reflectance of 93.0% or more for near-infrared light with a wavelength of 1080 nm that is incident on the diffuse reflective layer from the side of the three or more recording layers.

[0007] A laminate according to a second aspect of the present disclosure comprises three or more recording layers each capable of changing its color state to a different color by near-infrared laser light, and a diffuse reflective layer provided below the three or more recording layers, wherein the distance between the recording layer closest to the diffuse reflective layer among the three or more recording layers and the diffuse reflective layer is less than 150 μm.

[0008] A booklet according to the present disclosure includes at least one of the first laminate according to the first aspect of the present disclosure and the laminate according to the second aspect of the present disclosure.

[0009] A card according to the present disclosure comprises at least one of the laminate according to the first aspect of the present disclosure or the laminate according to the second aspect of the present disclosure.

[0010] A security document according to the present disclosure comprises at least one of the laminate according to the first aspect of the present disclosure and the second laminate according to the second aspect of the present disclosure.

[0011] The recording medium according to the present disclosure is a recording medium for security documents that can be written using near-infrared laser light that is diffusely reflected by a diffuse reflective layer, and is provided with a first recording layer, a first intermediate layer, a second recording layer, a second intermediate layer, a third recording layer, a third intermediate layer, a UV-cut layer, an adhesive layer, and a cover layer, in that order, and the first recording layer, the second recording layer, and the third recording layer are configured so that their colored states can be changed to different colors by near-infrared laser light, and the total light reflectance measured by placing the recording medium on the diffuse reflective layer that has a total light reflectance of 99.0% or more for near-infrared light with a wavelength of 1080 nm, and irradiating the near-infrared light with a wavelength of 1080 nm onto the diffuse reflective layer through the recording medium, is 93.0% or more.

[0012] FIG. 1 is a perspective view of a passport according to the first embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is a cross-sectional view of a recording medium. FIG. 4A is a diagram showing an example of the spread of diffusely reflected light when the distance D between the recording layer and the diffuse reflection layer is short. FIG. 4B is a diagram showing an example of the spread of diffusely reflected light when the distance D between the recording layer and the diffuse reflection layer is long. FIG. 5 is a cross-sectional view of a page according to a modified example. FIG. 6 is a cross-sectional view of a page according to a modified example. FIG. 7 is a cross-sectional view of a page according to a modified example. FIG. 8 is a cross-sectional view of a page according to a modified example. FIG. 9 is a cross-sectional view of a page according to a modified example. FIG. 10 is a cross-sectional view of a page according to a modified example. FIG. 11A is a cross-sectional view of a page according to a modified example. FIG. 11B is a cross-sectional view of a page according to a modified example. FIG. 12A is a cross-sectional view of a page according to a modified example. FIG. 12B is a cross-sectional view of a page according to a modified example. FIG. 13 is a cross-sectional view of a recording medium according to a modified example. FIG. 14 is a cross-sectional view of a recording medium according to a modified example. FIG. 15 is a cross-sectional view of a recording medium according to a modified example. FIG. 16 is a cross-sectional view of a recording medium according to a modified example. Fig. 17 is a cross-sectional view of a recording medium according to a modified example. Fig. 18 is a plan view of a card according to a modified example. Fig. 19 is a graph showing the results of measuring the spectral reflectance of an undrawn portion. Fig. 20 is a graph with the distance D between the diffuse reflective substrate and the first recording layer on the horizontal axis and the total light reflectance of an undrawn portion at a wavelength of 1080 nm on the vertical axis. Fig. 21 is a graph showing the results of measuring the spectral reflectance of an drawn portion. Fig. 22 is a graph with the distance D between the diffuse reflective substrate and the first recording layer on the horizontal axis and the total light reflectance of an drawn portion at a wavelength of 1080 nm on the vertical axis. Fig. 23A is a graph with the distance D between the diffuse reflective substrate and the first recording layer on the horizontal axis and the maximum drawing speed on the vertical axis. Fig. 23B is a graph with the distance D between the diffuse reflective substrate and the first recording layer on the horizontal axis and throughput on the vertical axis.

[0013] In the present disclosure, the total light reflectance of the laminate may be the total light reflectance of an undrawn portion of the laminate or the total light reflectance of a drawn portion of the laminate. In the present disclosure, it is sufficient that the total light reflectance of 93.0% or more is satisfied in at least a portion of the laminate.

[0014] In the present disclosure, in the description of "a diffuse reflective layer provided below three or more recording layers," "below three or more recording layers" is an expression indicating the relative positional relationship between the recording layer closest to the diffuse reflective layer among the three or more recording layers and the diffuse reflective layer, and includes not only a state in which the diffuse reflective layer is located directly below the recording layer without any other layer such as a light transmitting layer sandwiched between them, but also a state in which the diffuse reflective layer is located below the recording layer with another layer such as a light transmitting layer sandwiched between them.

[0015] In the present disclosure, near-infrared laser light refers to laser light having a peak wavelength (center wavelength) of 750 nm or more and 2500 nm or less. The peak wavelength of the near-infrared laser light used for recording on three or more recording layers is preferably 750 nm or more and 950 nm or less.

[0016] In this disclosure, visible light refers to light in the wavelength range of 360 nm or more and less than 750 nm, and near-infrared light refers to light in the wavelength range of 750 nm or more and 2500 nm or less.

[0017] In the present disclosure, a security document may be a booklet or a card.

[0018] The embodiments of the present disclosure will be described in the following order. In all the drawings of the following embodiments, the same or corresponding parts are denoted by the same reference numerals. 1. First embodiment (example of passport) 1.1 Passport configuration 1.2 Details of recording medium configuration 1.3 Passport manufacturing method 1.4 Passport drawing method 1.5 Effects 2. Second embodiment (example of passport) 2.1 Passport configuration 2.2 Effects 3. Modified example 4. Example

[0019] 1. First Embodiment [1.1 Passport Configuration] FIG. 1 is a perspective view of a passport 20 according to a first embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1 . The passport 20 is an example of a booklet, which is a security document. The passport 20 includes a cover 201, a back cover 202, and a plurality of pages 20A. The plurality of pages 20A includes a personal information page 20A. The personal information page 20A is an example of a laminate. The pages 20A other than the personal information page 20A may have the same configuration as the personal information page 20A, or may have a different configuration. Note that FIG. 1 shows an example in which a photograph 20P is drawn on the personal information page 20A, but the photograph 20P does not have to be drawn on the personal information page 20A. In other words, the passport 20 may be in a state before the photograph 20P is drawn on it. Furthermore, personal information other than the photograph 20P does not have to be drawn on the personal information page 20A. That is, the passport 20 may be in a state before any personal information other than the photograph 20P is drawn on it.

[0020] The configuration of the personal information page 20A will be described below with reference to FIG. 2 . The personal information page 20A is provided with a protective layer 24, a diffuse reflective layer 21, a light-transmitting layer 22, a recording medium 10, and a protective layer 23, in that order. Note that the protective layers 23 and 24 are provided as needed and are not essential components of the personal information page 20A. When the protective layers 23 and 24 are provided on the page 20A, the page 20A, which is an example of a laminate, can be made more robust. The layers of the laminate consisting of the protective layer 24, the diffuse reflective layer 21, the light-transmitting layer 22, the recording medium 10, and the protective layer 23 may be bonded together by fusion bonding.

[0021] (Diffuse Reflective Layer 21) The diffuse reflective layer 21 preferably has a white color. Here, white includes colors close to white, such as gray. The ISO whiteness of the diffuse reflective layer 21 is preferably 30% or more, more preferably 60% or more. The diffuse reflective layer 21 is capable of diffusively reflecting incident visible light and near-infrared light. The diffuse reflective layer 21 is preferably capable of diffusively reflecting visible light, thereby exhibiting a white color. Furthermore, the diffuse reflective layer 21 is capable of diffusively reflecting near-infrared light, thereby enabling the near-infrared light diffusely reflected by the diffuse reflective layer 21 to be used for drawing on the recording medium 10. The diffuse reflective layer 21 may also serve as a substrate supporting the light-transmitting layer 22 and the recording medium 10. In other words, the diffuse reflective layer 21 may be a diffuse-reflective substrate. Of the two surfaces of the diffuse reflective layer 21, a first surface on which the light-transmitting layer 22 and the recording medium 10 are provided may be printed with a design, picture, photograph, text, or a combination of two or more thereof (hereinafter referred to as a "design, etc."). Of both surfaces of the diffuse reflective layer 21, a design or the like may also be printed on a second surface opposite to the surface on which the light transmitting layer 22 and the recording medium 10 are provided. The diffuse reflective layer 21 itself may have a design or the like. An IC chip may be provided on the first or second surface of the diffuse reflective layer 21. The diffuse reflective layer 21 may include an IC chip therein. The IC chip stores, for example, information on the personal information page 20A (such as the name, nationality, date of birth, passport number, and photograph of the holder of the passport 20).

[0022] The diffuse reflective layer 21 contains, for example, fine particles and a polymer resin. The diffuse reflective layer 21 may contain at least one additive, if necessary. The at least one additive may include, for example, at least one selected from the group consisting of an antioxidant, an ultraviolet absorber, a fluorescent brightening agent, an antistatic agent, a flame retardant, and a surface modifier. In the first embodiment, an example in which the diffuse reflective layer 21 contains fine particles and a polymer resin is described. However, the diffuse reflective layer 21 is not limited to this example as long as it can diffusely reflect incident light. For example, the diffuse reflective layer 21 may contain a large number of voids, and the large number of voids may diffusely reflect incident light. The diffuse reflective layer 21 may also contain both voids and fine particles.

[0023] The fine particles are capable of diffusing and reflecting visible light and near-infrared light. The fine particles preferably contain a white pigment. Examples of the white pigment include at least one selected from the group consisting of titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, barium titanate, barium sulfate, aluminum hydroxide, aluminum oxide, zirconium oxide, silicon oxide, white carbon, clay, and talc. Among these, those with high reflectance for both visible light and near-infrared light are preferred. The shape of the fine particles may be, for example, spherical, ellipsoidal, needle-like, plate-like, scale-like, rod-like, or irregular, but is not limited to these shapes.

[0024] The polymer resin includes at least one selected from the group consisting of, for example, ester resins, amide resins, olefin resins, vinyl resins, acrylic resins, imide resins, styrene resins, urethane resins, engineering plastics, etc. When the diffuse reflective layer 21 includes two or more types of resins, the two or more types of resins may be mixed, copolymerized, or laminated.

[0025] The ester-based resin includes, for example, at least one selected from the group consisting of polyethylene terephthalate (PET)-based resin, polybutylene terephthalate (PBT)-based resin, polyethylene naphthalate (PEN)-based resin, polyethylene terephthalate-isophthalate copolymer-based resin, and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer-based resin. The amide-based resin includes, for example, at least one selected from the group consisting of nylon 6-based resin, nylon 66-based resin, and nylon 610-based resin. The olefin-based resin includes, for example, at least one selected from the group consisting of polyethylene (PE)-based resin, polypropylene (PP)-based resin, and polymethylpentene (PMP)-based resin. The vinyl-based resin includes, for example, polyvinyl chloride (PVC)-based resin.

[0026] The acrylic resin includes, for example, at least one selected from the group consisting of polyacrylate resins, polymethacrylate resins, and polymethyl methacrylate (PMMA) resins. The imide resin includes, for example, at least one selected from the group consisting of polyimide (PI) resins, polyamideimide (PAI) resins, and polyetherimide (PEI) resins. The styrene resin includes, for example, at least one selected from the group consisting of polystyrene (PS) resins, high-impact polystyrene resins, acrylonitrile-styrene resins (AS resins), and acrylonitrile-butadiene-styrene resins (ABS resins). The urethane resin includes, for example, at least one selected from the group of resins containing urethane bonds, such as polyurethane resins and urethane rubber. The engineering plastic includes at least one selected from the group consisting of, for example, polycarbonate (PC)-based resins, polyarylate (PAR)-based resins, polysulfone (PSF)-based resins, polyethersulfone (PES)-based resins, polyphenylene ether (PPE)-based resins, polyphenylene sulfide (PPS)-based resins, polyether ketone (PEK)-based resins, polyether-ether ketone (PEEK)-based resins, polyphenylene oxide (PPO)-based resins, and polyether sulfite-based resins. From the viewpoint of environmental friendliness, the polymer resin preferably includes at least one selected from the group consisting of polycarbonate (PC)-based resins, polyethylene terephthalate (PET)-based resins, and the like, among the above resins.

[0027] (Light-Transmitting Layer 22) The light-transmitting layer 22 is provided between the diffuse reflective layer 21 and the recording medium 10. The light-transmitting layer 22 is configured to be able to transmit visible light and near-infrared light. The light-transmitting layer 22 may be configured as a film. The light-transmitting layer 22 includes a polymer resin. The light-transmitting layer 22 may include at least one additive selected from the group consisting of an antistatic agent, a flame retardant, a surface modifier, etc., as necessary. The light-transmitting layer 22 may have a pattern or the like on at least one of its surface and interior. The light-transmitting layer 22 may also include an IC chip on at least one of its surface and interior. Here, the surface of the light-transmitting layer 22 refers to at least one of the first surface facing the recording medium 10 and the second surface facing the diffuse reflective layer 21.

[0028] The polymer resin includes at least one additive selected from the group consisting of, for example, polycarbonate (PC)-based resins, polyethylene terephthalate (PET)-based resins, triacetyl cellulose (TAC)-based resins, polyester (TPEE)-based resins, polyethylene naphthalate (PEN)-based resins, polyimide (PI)-based resins, polyamide (PA)-based resins, aramid-based resins, polyethylene (PE)-based resins, polyacrylate-based resins, polyethersulfone-based resins, polysulfone-based resins, polypropylene (PP)-based resins, diacetyl cellulose-based resins, polyvinyl chloride-based resins, acrylic (PMMA)-based resins, epoxy-based resins, urea-based resins, urethane-based resins, melamine-based resins, cycloolefin polymer (COP)-based resins, and cycloolefin copolymer-based resins. From the viewpoint of environmental friendliness, the polymer resin preferably includes at least one additive selected from the group consisting of polycarbonate (PC)-based resins, polyethylene terephthalate (PET)-based resins, and the like, among the above resins.

[0029] (Recording Medium 10) The recording medium 10 is a recording medium for security documents that can be imaged using near-infrared laser light that is diffusely reflected by a diffuse reflection layer 21. The recording medium 10 is provided on a light transmission layer 22. The recording medium 10 has a peak wavelength λ １ Laser light L having １ , peak wavelength λ ２ Laser light L having２ and peak wavelength λ ３ Laser light L having ３ A multicolor image can be drawn by the laser light L １ , laser light L ２ and laser light L ３ is near-infrared laser light.

[0030] The recording medium 10 is exposed to the laser light L １ As a result, the laser light L transmitted through the recording medium 10 １ The light can be diffusely reflected by the diffuse reflection layer 21 and re-enter the recording layer 13A. Therefore, the light diffusely reflected by the diffuse reflection layer 21 can be used to write on the recording layer 13A located furthest from the light incident surface of the page 20A. This improves the recording sensitivity of the recording layer 13A.

[0031] The recording medium 10 is exposed to the laser light L １ and laser light L ２ It is preferable that the recording medium 10 is configured to be able to transmit the laser light L １ and laser light L ２ are diffusely reflected by the diffuse reflection layer 21 and can be re-entered into the recording layers 13A and 13B. Therefore, the light diffusely reflected by the diffuse reflection layer 21 can be used to draw on the recording layer 13A located furthest from the light incident surface of the page 20A and the recording layer 13B located in front of it. This makes it possible to improve the recording sensitivity of the recording layers 13A and 13B.

[0032] The recording medium 10 is exposed to the laser light L １ , laser light L ２ and laser light L ３ It is more preferable that the recording medium 10 is configured to be able to transmit the laser light L １ , laser light L ２ and laser light L ３are diffusely reflected by the diffuse reflection layer 21 and can be re-entered onto the recording layers 13A, 13B, and 13C. Therefore, the light diffusely reflected by the diffuse reflection layer 21 can be used to draw on the recording layer 13A located at the innermost side from the light incident surface of the page 20A, and the recording layers 13B and 13C located in front of it. This makes it possible to improve the recording sensitivity of the recording layers 13A, 13B, and 13C.

[0033] Laser light L １ The color of the first color-forming portion formed by irradiation with the laser light L ２ The color of the second color-forming portion formed by irradiation and the laser light L ３ The colors of the third color-forming portions formed by the irradiation of the third color-forming portions are different from each other. This makes it possible to print a multicolor image on the recording medium 10.

[0034] In the first embodiment, an example will be described in which the multicolor image is a full-color image. The recording medium 10 is configured so that its color state can be changed by irradiation with laser light (external stimulus). This change in color state makes it possible to draw a full-color image on the recording medium 10. The full-color image may be, for example, a photograph such as a face photo, a design or color pattern, or text such as letters or symbols. The full-color image may be composed of a combination of two or more of the photograph, design, color pattern, and text.

[0035] The change in coloring state may be a reversible change or an irreversible change. That is, the recording medium 10 may be rewritable, which allows images and the like to be rewritten, or may be write-once, which allows images and the like to be written only once. From the viewpoint of preventing tampering, it is preferable that the change in coloring state be an irreversible change.

[0036] 3, the recording medium 10 includes three recording layers 13A, 13B, and 13C. Of the three recording layers 13A, 13B, and 13C, the recording layer 13A is the recording layer closest to the diffuse reflection layer 21. The configuration of the recording medium 10 will be described in detail later.

[0037] (Protective layers 23, 24) The protective layer 23 is provided on the recording medium 10. The protective layer 24 is provided below the diffuse reflective layer 21. The protective layers 23, 24 protect the surface of the recording medium 10. At least one of the surface and interior of the protective layer 23 may have a pattern or the like. Similarly, at least one of the surface and interior of the protective layer 24 may have a pattern or the like. Here, the surface of the protective layer 23 refers to at least one of the first surface facing the recording medium 10 and the second surface facing the recording medium 10. Furthermore, the surface of the protective layer 24 refers to at least one of the first surface facing the diffuse reflective layer 21 and the second surface facing the diffuse reflective layer 21.

[0038] The protective layer 23 is configured to be able to transmit visible light and near-infrared light. The protective layer 24 may or may not be configured to be able to transmit visible light. The protective layers 23 and 24 are, for example, films or coating layers.

[0039] The film contains, for example, a polymer resin. Examples of the polymer resin include the same materials as those of the light-transmitting layer 22. The film may contain additives as needed.

[0040] The coating layer may be an ultraviolet-curable resin layer. The ultraviolet-curable resin may include, for example, at least one selected from the group consisting of radical polymerization type ultraviolet-curable resins and cationic polymerization type ultraviolet-curable resins. The ultraviolet-curable resin may include additives as needed. The additives may include, for example, at least one selected from the group consisting of sensitizers, fillers, stabilizers, leveling agents, ultraviolet absorbers, antistatic agents, antifoaming agents, viscosity modifiers, etc. Specifically, the ultraviolet-curable resin may include, for example, an acrylic ultraviolet-curable resin. Furthermore, a hard coating layer may be used as the coating layer.

[0041] (Total Light Reflectance of Page 20A) The total light reflectance of page 20A for near-infrared light having a wavelength of 1080 nm that is incident on diffuse reflective layer 21 from the recording medium 10 side is 93.0% or more, preferably 93.5% or more, more preferably 94.0% or more, and even more preferably 94.5% or more. Here, the total light reflectance of page 20A may be the total light reflectance of the depicted portion of page 20A or the total light reflectance of the undrawn portion of page 20A. This is because recording layers 13A, 13B, and 13C are substantially non-absorbent for near-infrared light having a wavelength of 1080 nm both before and after drawing, and therefore the total light reflectance of the depicted portion of page 20A and the total light reflectance of the undrawn portion of page 20A are substantially the same value.

[0042] A high total light reflectance can suppress light absorption by the light transmitting layer 22 between the diffuse reflective layer 21 and the recording medium 10, thereby increasing the amount of diffusely reflected light incident on the imaged portion of the recording medium 10 through the light transmitting layer 22. This improves the recording sensitivity of the recording medium 10, particularly the recording sensitivity of the recording layer 13A furthest from the light incident surface of the page 20A, and improves the imaged portion of the passport 20. This shortens the time required to issue the passport 20.

[0043] On the other hand, if the total light reflectance is low, it is not possible to suppress light absorption by the light-transmitting layer 22 between the diffuse reflection layer 21 and the recording medium 10, and the amount of diffusely reflected light incident on the imaged portion decreases. This reduces the recording sensitivity of the recording medium 10, particularly the recording sensitivity of the recording layer 13A furthest from the light incident surface of the page 20A, slowing down the imaged portion. This may result in a longer time required to issue the passport 20.

[0044] The recording layer 13A furthest from the light incident surface (i.e., of the recording layers 13A, 13B, and 13C, the recording layer 13A closest to the diffuse reflection layer 21) is the most susceptible to a decrease in sensitivity, and therefore limiting the range of total light reflectance is particularly effective in improving the recording sensitivity of the recording layer 13A. However, the effect of improving the recording sensitivity by limiting the range of total light reflectance is not limited to the recording layer 13A, and limiting the range of total light reflectance can also improve the recording sensitivity of the recording layers 13B and 13C.

[0045] (Method for Measuring Total Light Reflectance of Unimaged Area of ​​Recording Medium 10) The total light reflectance of the unimaged area of ​​recording medium 10 on page 20A (hereinafter referred to as the "unimaged area") is measured as follows. First, an unimaged area is selected from page 20A, and a measurement sample is prepared by cutting out page 20A to a predetermined size so as to include the unimaged area. Next, a spectrometer equipped with an integrating sphere unit is used to irradiate the measurement sample from the protective layer 23 side with light, and the total light reflectance (the total reflectance of diffusely reflected light and specularly reflected light) of the unimaged area in the wavelength range of 380 to 1100 nm is measured, thereby obtaining a total light reflectance spectrum. The total light reflectance at a wavelength of 1080 nm is extracted from the obtained spectrum. The reason for extracting the total light reflectance at a wavelength of 1080 nm is that recording layers 13A, 13B, and 13C do not have optical absorption properties for near-infrared light at a wavelength of 1080 nm. By selecting a wavelength that does not have light absorption in this way, it is possible to suppress the influence of light absorption by each recording layer 13A, 13B, and 13C on the measurement of total light reflectance. Table 1 shows details of the equipment and measurement conditions used for the measurement.

[0046] (Method for measuring the total light reflectance of the drawn portion of the recording medium 10) First, the drawn portion of the recording medium 10 (hereinafter referred to as the "drawn portion") is selected from the page 20A, and a measurement sample is prepared by cutting out the page 20A to a predetermined size so as to include the drawn portion. Next, a spectroscopic spectrum of the total light reflectance of the drawn portion of the measurement sample is obtained in the same manner as in measuring the total light reflectance of the undrawn portion, and then the total light reflectance at a wavelength of 1080 nm is extracted from the spectroscopic spectrum.

[0047] (Total light reflectance measured by placing the recording medium 10 before incorporation into page 20A on a diffuse reflective layer) The recording medium 10 before incorporation into page 20A is placed on a diffuse reflective layer having a total light reflectance of 99.0% or more for near-infrared light with a wavelength of 1080 nm, and near-infrared light with a wavelength of 1080 nm is incident on the diffuse reflective layer (hereinafter referred to as the "diffuse reflective layer for measurement") through the recording medium 10. The total light reflectance (hereinafter referred to as the "total light reflectance before incorporation") measured by this is 93.0% or more. A total light reflectance of 93.0% or more before incorporation can increase the amount of diffusely reflected light (light diffusely reflected by the diffuse reflective layer 21) incident on the recording medium 10 when the recording medium 10 is incorporation into page 20A. Therefore, when the recording medium 10 is incorporation into page 20A, the recording sensitivity of the recording medium 10, particularly the recording sensitivity of the recording layer 13A furthest from the light incident surface of page 20A, can be improved, thereby improving the drawing speed of the passport 20. Therefore, the time required to issue the passport 20 can be shortened.

[0048] The measurement diffuse reflective layer used to measure the total light reflectance before assembly need only have a total light reflectance of 99.0% or more for near-infrared light with a wavelength of 1080 nm, and may be the same as the diffuse reflective layer 21 provided on page 20A, or may be different from the diffuse reflective layer 21.

[0049] Because the recording medium 10 is imaged after being incorporated into the page 20A, the recording medium 10 before being incorporated into the page 20A is usually in an unimaged state. However, a design or the like may be imaged in advance on a portion of the recording medium 10 before being incorporated into the page 20A. In this case, the total light reflectance before being incorporated may be either the total light reflectance measured using the imaged portion of the recording medium 10 or the total light reflectance measured using the unimaged portion of the recording medium 10. This is because, as described in the explanation of "Total Light Reflectance of Page 20A," the recording layers 13A, 13B, and 13C do not substantially absorb near-infrared light with a wavelength of 1080 nm either before or after imaged, and therefore the total light reflectance measured using the imaged portion of the recording medium 10 and the total light reflectance measured using the unimaged portion of the recording medium 10 are approximately the same value.

[0050] (Method for Measuring Total Light Reflectance of Measurement Diffuse Reflective Layer) The total light reflectance of the measurement diffuse reflective layer used to measure the total light reflectance before assembly is specifically measured as follows. First, the measurement diffuse reflective layer is cut to a predetermined size to prepare a measurement sample. Note that if the measurement diffuse reflective layer is an appropriate size for the measurement sample, cutting out the measurement diffuse reflective layer is not necessary, and the measurement diffuse reflective layer may be used as the measurement sample without cutting out. Next, a spectroscopic spectrum of the total light reflectance of the measurement sample is obtained in the same manner as the method for measuring the total light reflectance of the unimaged portion of the recording medium 10, except that the measurement sample prepared as described above is used. Thereafter, the total light reflectance at a wavelength of 1080 nm is extracted from the spectroscopic spectrum.

[0051] (Method for Measuring Total Light Reflectance Before Assembling) The total light reflectance before assembly is specifically measured as follows. First, a laminate is obtained by thermocompression bonding the recording medium 10 before assembly and a diffuse reflective layer for measurement. Note that if it is difficult to bond the recording medium 10 and the diffuse reflective layer for measurement by thermocompression bonding, a laminate is obtained by bonding the recording medium 10 and the diffuse reflective layer for measurement with an adhesive layer (OCA) having a thickness of 15 μm. Next, the laminate is cut to a predetermined size to prepare a measurement sample. Note that if the laminate is an appropriate size for the measurement sample, cutting out the laminate is not necessary, and the laminate may be used as is as the measurement sample. Next, a spectroscopic spectrum of the total light reflectance of the measurement sample is obtained in the same manner as the method for measuring the total light reflectance of the unimaged portion of the recording medium 10, except that the measurement sample obtained as described above is used. Thereafter, the total light reflectance at a wavelength of 1080 nm is extracted from the spectroscopic spectrum. Note that when measuring the spectroscopic spectrum, light is irradiated onto the surface of the measurement sample facing the recording medium 10.

[0052] [1.2 Details of the Structure of the Recording Medium] The structure of the recording medium 10 will be described in detail below with reference to FIG. 3. The recording medium 10 includes, in order, a substrate 11, an intermediate layer 12A, a recording layer 13A, an intermediate layer 12B, a recording layer 13B, an intermediate layer 12C, a recording layer 13C, an intermediate layer 12D, and a cover layer 14. Note that the substrate 11, the intermediate layer 12A, the intermediate layer 12D, and the cover layer 14 are provided as needed. In this specification, when intermediate layer 12A, intermediate layer 12B, intermediate layer 12C, and intermediate layer 12D are referred to collectively without any particular distinction, they may be referred to as intermediate layer 12. Similarly, when recording layer 13A, recording layer 13B, and recording layer 13C are referred to collectively without any particular distinction, they may be referred to as recording layer 13. In the first embodiment, an example will be described in which the recording medium 10 is disposed between the light transmitting layer 22 and the protective layer 23 so that the substrate 11 faces the light transmitting layer 22 and the cover layer 14 faces the protective layer 23. However, the arrangement of the recording medium 10 is not limited to this example, and the recording medium 10 may be disposed between the light transmitting layer 22 and the protective layer 23 so that the cover layer 14 faces the light transmitting layer 22 and the substrate 11 faces the protective layer 23.

[0053] (Substrate 11) The substrate 11 supports the intermediate layer 12A, the recording layer 13A, the intermediate layer 12B, the recording layer 13B, the intermediate layer 12C, the recording layer 13C, the intermediate layer 12D, and the cover layer 14. The substrate 11 is preferably made of a material that has excellent heat resistance and excellent dimensional stability in the in-plane direction of the substrate 11. The substrate 11 is configured to be able to transmit visible light and near-infrared light. The substrate 11 may be flexible. The substrate 11 is made of, for example, a film. In the present disclosure, the term "film" is defined to include a sheet. The substrate 11 includes, for example, a polymer resin. Examples of the polymer resin include the same materials as those used for the light-transmitting layer 22. The substrate 11 may contain additives as needed.

[0054] (Recording layers 13A, 13B, 13C) Recorded recording layers 13A, 13B, and 13C are in a colored state, while unrecorded recording layers 13A, 13B, and 13C are in a decolored state. Recording layers 13A, 13B, and 13C can be changed from a decolored state to a colored state by irradiation with laser light.

[0055] The recording layers 13A, 13B, and 13C can each exhibit a different hue in the color-developed state. Specifically, the recording layer 13A can exhibit magenta in the color-developed state. The recording layer 13B can exhibit cyan in the color-developed state. The recording layer 13C can exhibit yellow in the color-developed state. The magenta, cyan, and yellow colors are examples of the first, second, and third primary colors, respectively. The first, second, and third primary colors may be the three primary colors. The first, second, and third primary colors may be colors other than magenta, cyan, and yellow. The laser light L capable of changing the recording layer 13A into the color-developed state １ , laser light L capable of changing the recording layer 13B into a colored state. ２ , and laser light L capable of changing the recording layer 13C into a color-developing state. ３ have different peak wavelengths.

[0056] The thicknesses of recording layers 13A, 13B, and 13C are each independently preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 15 μm or less. When recording layers 13A, 13B, and 13C are 1 μm or more in thickness, the color density can be improved. On the other hand, when recording layers 13A, 13B, and 13C are 20 μm or less in thickness, an increase in the amount of heat utilized by recording layers 13A, 13B, and 13C can be suppressed, and deterioration of color development can be suppressed.

[0057] The recording layer 13A has a peak wavelength λ １ Laser light L having １The recording layer 13A is configured to be capable of recording by the above-mentioned method. The recording layer 13A contains a first color former having electron donating properties, a first color developer having electron accepting properties, and a first photothermal conversion agent. The recording layer 13A preferably further contains a first matrix resin.

[0058] The recording layer 13B has a peak wavelength λ ２ Laser light L having ２ The recording layer 13B is configured to be capable of recording by the above-mentioned method. The recording layer 13B contains a second color former having electron donating properties, a second color developer having electron accepting properties, and a second photothermal conversion agent. The recording layer 13B preferably further contains a second matrix resin.

[0059] The recording layer 13C has a peak wavelength λ ３ Laser light L having ３ The recording layer 13C is configured to be capable of recording by the above. The recording layer 13C contains a third color former having electron donating properties, a third color developer having electron accepting properties, and a third photothermal conversion agent. The recording layer 13C preferably further contains a third matrix resin.

[0060] Laser light L １ , laser light L ２ and laser light L ３ is preferably a near-infrared laser beam. １ , peak wavelength λ ２ and peak wavelength λ ３ is preferably included in the near infrared region. １ , peak wavelength λ ２ and peak wavelength λ ３ is preferably selected from the range of 750 nm to 950 nm.

[0061] Peak wavelength λ １ , peak wavelength λ ２ and peak wavelength λ ３ are different from one another, thereby allowing the recording layers 13A, 13B, and 13C to develop colors independently.

[0062] (First color former, second color former, third color former) The first color former, second color former, and third color former are capable of developing colors by reacting with the first color former, second color former, and third color former, respectively. The first color former, second color former, and third color former are capable of developing different hues in a colored state. Specifically, the first color former is capable of developing magenta in a colored state. The second color former is capable of developing cyan in a colored state. The third color former is capable of developing yellow in a colored state.

[0063] The first color former, the second color former, and the third color former are, for example, leuco dyes. When a lactone ring in the leuco dye molecule reacts with an acid, the lactone ring opens and develops color. When the open lactone ring in the leuco dye reacts with a base, it may close and disappear. The leuco dye may be, for example, an existing dye for thermal paper.

[0064] The first color former, the second color former, and the third color former are not particularly limited and can be appropriately selected depending on the purpose. The first color former, the second color former, and the third color former each independently include at least one compound selected from the group consisting of, for example, fluoran-based compounds, triphenylmethanephthalide-based compounds, azaphthalide-based compounds, phenothiazine-based compounds, leucoauramine-based compounds, and indolinophthalide-based compounds. In addition, the first color former, the second color former and the third color former each independently include, for example, 2-anilino-3-methyl-6-diethylaminofluoran, 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-amyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-sec-butyl-N-methylamino)fluoran, 2-anilino-3-methyl-6-(N-n-amyl-N-ethylamino)fluoran, Fluoran, 2-anilino-3-methyl-6-(N-iso-amyl-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-toluidino)fluoran, 2-anilino-3-methyl-6-(N-methyl-p-toluidino)fluoran, 2-(m-trichloromethylanilino)-3-methyl-6-diethylaminofluoran, 2-(m-trifluoromethylanilino)-3-methyl-6-diethylaminofluoran, 2-(m-trichloromethylanilino)-3-methyl-6-(N-cyclohexyl-N-methylamino)fluoran, 2-(2,4-dimethylanilino)-3-methyl-6-diethylaminofluoran, 2-(N-ethyl-p-toluidino)-3-methyl-6-(N-ethylanilino)fluoran, 2-(N-ethyl-p-toluidino)-3-methyl-6-(N-propyl-p-toluidino)fluoran, 2-anilino-6-(N-n-hexyl-N-ethylamino)fluoran, 2-(o-chloroanilino)-6-diethylaminofluoran, 2-(o-chloroanilino)-6-dibutylaminofluoran, 2-(m-trifluoromethylanilino)-6-diethylaminofluoran, 2,3-dimethyl-6-dimethylaminofluoran, 3-methyl-6-(N-ethyl-p-toluidino)fluoran, 2-chloro-6 -diethylaminofluoran, 2-bromo-6-diethylaminofluoran, 2-chloro-6-dipropylaminofluoran, 3-chloro-6-cyclohexylaminofluoran, 3-bromo-6-cyclohexylaminofluoran, 2-chloro-6-(N-ethyl-N-isoamylamino)fluoran, 2-chloro-3-methyl-6-diethylaminofluoran, 2-anilino-3-chloro-6-diethylaminofluoran, 2-(o-chloroanilino)-3-chloro-6-cyclohexylaminofluoran, 2-(m-trifluoromethylanilino)-3-chloro-6-diethylaminofluoran, 2-(2,3-dichloroanilino)-3-chloro-6-diethylaminofluoran, 1,2-benzo-6-diethylaminofluoran, 3-diethylamino-6-(m-trifluoromethylanilino)fluoran, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-7-azaphthalide, 3-(1-octyl- 2-methylindol-3-yl)-3-(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-methyl-4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-methyl-4-diethylaminophenyl)-7-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(2-methyl-4-diethylaminophenyl)-7-azaphthalide 3-(1-ethyl-2-methylindol-3-yl)-3-(4-diethylaminophenyl)-4-azaphthalide, 3-(1-ethyl-2-methylindol-3-yl)-3-(4-N-n-amyl-N-methylaminophenyl)-4-azaphthalide, 3-(1-methyl-2-methylindol-3-yl)-3-(2-hexyloxy-4-diethylaminophenyl)-4-azaphthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-4-azaphthalide nyl)-4-azaphthalide, 3,3-bis(2-ethoxy-4-diethylaminophenyl)-7-azaphthalide, 2-(p-acetylanilino)-6-(N-n-amyl-N-n-butylamino)fluoran, 2-benzylamino-6-(N-ethyl-p-toluidino)fluoran, 2-benzylamino-6-(N-methyl-2,4-dimethylanilino)fluoran, 2-benzylamino-6-(N-ethyl-2,4-dimethylanilino)fluoran, 2-benzylamino-6-(N-methyl-p-toluidino)fluoran, 2-benzylamino-6-(N-ethyl-p-toluidino)fluoran, 2-(di-p-methylbenzylamino)-6-(N-ethyl-p-toluidino)fluoran, 2-(α-phenylethylamino)-6-(N-ethyl-p-toluidino)fluoran, 2-methylamino-6-(N-methylanilino)fluoran, 2-methylamino-6-(N-ethylanilino)fluoran, 2-methylamino-6-(N-propylanilino)fluoran , 2-ethylamino-6-(N-methyl-p-toluidino)fluoran, 2-methylamino-6-(N-methyl-2,4-dimethylanilino)fluoran, 2-ethylamino-6-(N-ethyl-2,4-dimethylanilino)fluoran, 2-dimethylamino-6-(N-methylanilino)fluoran, 2-dimethylamino-6-(N-ethylanilino)fluoran, 2-diethylamino-6-(N-methyl-p-toluidino)fluoran, 2-diethylamino-6-(N-ethyl-p-toluidino)fluoran, 2-dipropylamino-6-(N-methyl p-toluidino)fluoran, 2-dipropylamino-6-(N-ethylanilino)fluoran, 2-amino-6-(N-methylanilino)fluoran, 2-amino-6-(N-ethylanilino)fluoran, 2-amino-6-(N-propylanilino)fluoran, 2-amino-6-(N-methyl-p-toluidino)fluoran, 2-amino-6-(N-ethyl-p-toluidino)fluoran, 2-amino-6-(N-propyl-p-toluidino)fluoran, 2-amino-6-(N-methyl-p-ethylanilino)fluoran, 2-amino-6-(N-ethylanilino)fluoran 2-amino-6-(N-propyl-p-ethylanilino)fluoran, 2-amino-6-(N-methyl-2,4-dimethylanilino)fluoran, 2-amino-6-(N-ethyl-2,4-dimethylanilino)fluoran, 2-amino-6-(N-propyl-2,4-dimethylanilino)fluoran, 2-amino-6-(N-methyl-p-chloroanilino)fluoran, 2-amino-6-(N-ethyl-p-chloroanilino)fluoran, 2-amino-6-(N-propyl-p-chloroanilino)fluoran, 1,It may contain at least one selected from the group consisting of 2-benzo-6-(N-ethyl-N-isoamylamino)fluoran, 1,2-benzo-6-dibutylaminofluoran, 1,2-benzo-6-(N-methyl-N-cyclohexylamino)fluoran, and 1,2-benzo-6-(N-ethyl-N-toluidino)fluoran.

[0065] (First color developer, second color developer, third color developer) The first color developer, second color developer, and third color developer are capable of causing the first color former compound, second color former compound, and third color former compound in a decolorized state to develop color, respectively. The first color developer, second color developer, and third color developer may be the same type, or the first color developer, second color developer, and third color developer may be different types. The first color developer, second color developer, and third color developer are compounds containing an electron-accepting group in the molecule. The electron-accepting moiety of the first color developer, second color developer, and third color developer reacts with the lactone ring of the first color former compound, second color former compound, and third color former compound, respectively, opening the lactone ring, causing the first color former compound, second color former compound, and third color former compound to develop color. The first color developer, the second color developer, and the third color developer each independently contain at least one selected from the group consisting of, for example, phenol derivatives, salicylic acid derivatives, urea derivatives, etc. In the following description, when the first color developer, the second color developer, and the third color developer are referred to collectively without any particular distinction, they may be simply referred to as color developers.

[0066] Specifically, for example, the color developer contains a compound represented by the following formula (1). (However, in formula (1), X 0 is a divalent group containing at least one benzene ring. 01 , Y 02 are each independently a monovalent group. n01 and n02 are each independently an integer of 0 to 5. When n01 is an integer of 2 to 5, Y 01 may be the same or different. When n02 is an integer of 2 to 5, Y 02 may be the same or different. 01 , Z 02are each independently a hydrogen-bonding group.

[0067] X 0 contains at least one benzene ring, 0 Since the melting point can be made higher than when X is an aliphatic hydrocarbon group (for example, a normal alkyl chain), the color retention properties during storage at high temperature and high humidity (hereinafter referred to as "high temperature and high humidity storage properties") can be improved. 0 Preferably, the compound has at least two benzene rings. The high-temperature, high-humidity storage characteristics are, for example, storage characteristics under an environment of 80°C and 60% RH. Improved heat resistance improves the resistance of the recording medium 10 to harsh processes (for example, hot pressing or integral molding using molten resin, etc.). 0 When contains at least two benzene rings, the at least two benzene rings may be condensed, for example, naphthalene or anthracene.

[0068] Z 01 , Z 02 are each independently a hydrogen-bonding group, the color developers tend to exist in a state of being aggregated together to some extent via hydrogen bonds, thereby improving the stability of the color developer in the recording layer 13. In this specification, the hydrogen-bonding group means a functional group containing an atom that can form a hydrogen bond with another functional group or an atom present in another compound, etc.

[0069] The color developer preferably contains a compound represented by the following formula (2): (However, in formula (2), X 1 is a divalent group containing at least one benzene ring. 11 , Y 12 , Y 13 , Y 14 are each independently a monovalent group. 11 , Z 12 are each independently a hydrogen-bonding group.

[0070] X 1 contains at least one benzene ring, 1In comparison with the case where X is an aliphatic hydrocarbon group (for example, a normal alkyl chain), the melting point can be made higher, and therefore the high-temperature, high-humidity storage properties can be improved. 1 Preferably, X contains at least two benzene rings. 1 When contains at least two benzene rings, the at least two benzene rings may be condensed, for example, naphthalene or anthracene.

[0071] Z 11 , Z 12 are each independently a hydrogen-bonding group, the color developer tends to exist in a state of being solidified to some extent via hydrogen bonds, and the stability of the color developer in the recording layer 13 is improved.

[0072] When formula (1) and formula (2) contain a hydrocarbon group, the hydrocarbon group is a general term for a group composed of 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 that does not have a carbon-carbon multiple bond, and an unsaturated hydrocarbon group is an aliphatic hydrocarbon group that has a carbon-carbon multiple bond (a carbon-carbon double bond or a carbon-carbon triple bond).

[0073] When formula (1) and formula (2) contain a hydrocarbon group, the hydrocarbon group may be a chain or may contain one or more rings. The chain may be a straight chain or a branched chain having one or more side chains.

[0074] (X containing one benzene ring 0 , X １ ) 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, for example, represented by the following formula (3): (However, in formula (3), X 21 It doesn't matter if it's there or not, X 21 If there is X 21 is a divalent group. 22 It doesn't matter if it's there or not, X 22 If there is X 22is a divalent group. 21 is a monovalent group. n21 is an integer of 0 to 4. When n21 is an integer of 2 to 4, R 21 may be the same or different. * indicates a bond.)

[0075] In formula (3), X to the benzene ring 21 and X 22 The bonding position of X to the benzene ring is not limited. 21 and X 22 The bonding position may be any of the ortho, meta and para positions.

[0076] The divalent group containing one benzene ring is preferably represented by the following formula (4) from the viewpoint of improving high-temperature, high-humidity storage properties. (However, in formula (4), R 22 is a monovalent group. n22 is an integer of 0 to 4. When n22 is an integer of 2 to 4, R 22 may be the same or different. * indicates a bond.)

[0077] X in formula (1) 0 is a divalent group containing one benzene ring, in formula (4), Z 01 and Z 02 The bonding position of Z to the benzene ring is not limited. 01 and Z 02 The bonding position may be any of the ortho, meta and para positions.

[0078] X in formula (2) 1 is a divalent group containing one benzene ring, in formula (4), Z 11 and Z 12 The bonding position of Z to the benzene ring is not limited. 11 and Z 12 The bonding position may be any of the ortho, meta and para positions.

[0079] (X 21 , X 22) X in formula (3) 21 , X 22 are each independently a divalent group and are not particularly limited, but an example is a hydrocarbon group which may have a substituent. The hydrocarbon group is preferably chain-like. When the hydrocarbon group is chain-like, the melting point of the color developer can be lowered, so that the color developer melts upon irradiation with laser light, making it easier for the color former to develop color. From the viewpoint of lowering the melting point of the color developer, a normal alkyl chain is particularly preferred among chain-like hydrocarbon groups.

[0080] The hydrocarbon group which may have a substituent has, for example, 1 to 15 carbon atoms, 1 to 13 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 3 carbon atoms.

[0081] X in formula (3) 21 , X 22 When is a normal alkyl group, the number of carbon atoms in the normal alkyl group is preferably 8 or less, more preferably 6 or less, even more preferably 5 or less, and particularly preferably 3 or less, from the viewpoint of high-temperature storage stability. When the normal alkyl group has 8 or less carbon atoms, the normal alkyl group is short in length, so that thermal disturbance is unlikely to occur in the color developer during high-temperature storage, and it is thought that the site that interacted with the color former such as a leuco dye during color development is unlikely to be dissociated. Therefore, the color former such as a leuco dye is unlikely to fade during high-temperature storage, improving high-temperature storage stability.

[0082] Examples of the substituent that the hydrocarbon group may have include a halogen group (e.g., a fluorine group) or an alkyl group having a halogen group (e.g., a fluorine group), etc. The hydrocarbon group that may have a substituent may be one in which some of the carbon atoms of the hydrocarbon group (e.g., some of the carbon atoms contained in the main chain of the hydrocarbon group) are substituted with an element such as oxygen.

[0083] (R 21 ) R in formula (3) 21 is not particularly limited as long as it is a monovalent group, but examples thereof include a halogen group or a hydrocarbon group which may have a substituent.

[0084] The halogen group is, for example, a fluorine group (--F), a chlorine group (--Cl), a bromine group (--Br), or an iodine group (--I).

[0085] The hydrocarbon group which may have a substituent has, for example, 1 to 15 carbon atoms, 1 to 13 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 3 carbon atoms.

[0086] Examples of the substituent that the hydrocarbon group may have include a halogen group (e.g., a fluorine group) or an alkyl group having a halogen group (e.g., a fluorine group), etc. The hydrocarbon group that may have a substituent may be one in which some of the carbon atoms of the hydrocarbon group (e.g., some of the carbon atoms contained in the main chain of the hydrocarbon group) are substituted with an element such as oxygen.

[0087] (R 22 ) R in formula (4) 22 is not particularly limited as long as it is a monovalent group, but examples thereof include a halogen group and a hydrocarbon group which may have a substituent. The halogen group and the hydrocarbon group which may have a substituent are respectively represented by R 21 is the same as:

[0088] (X containing two benzene rings 0 , X 1 ) X in formula (1) 0 and X in formula (2) 1 is, for example, a divalent group containing two benzene rings. The divalent group is, for example, represented by the following formula (5): (However, in formula (5), X 31 It doesn't matter if it's there or not, X 31 If there is X 31 is a divalent group. 32 It doesn't matter if it's there or not, X 32 If there is X 32 is a divalent group. 33 It doesn't matter if it's there or not, X 33 If there is X 33 is a divalent group. 31 , R 32are each independently a monovalent group. n31 and n32 are each independently an integer of 0 to 4. When n31 is an integer of 2 to 4, R 31 may be the same or different. When n32 is an integer of 2 to 4, R 32 may be the same or different. * indicates a bond.)

[0089] In formula (5), X to the benzene ring 31 and X 32 The bonding position of X to the benzene ring is not limited. 31 and X 32 The bonding position of X to the benzene ring in formula (5) may be any of the ortho, meta and para positions. 32 and X 33 The bonding position of X to the benzene ring is not limited. 32 and X 33 The bonding position may be any of the ortho, meta and para positions.

[0090] The divalent group containing two benzene rings is preferably represented by the following formula (6) from the viewpoint of improving high-temperature, high-humidity storage properties. (However, in formula (6), X 34 is a divalent group. 33 , R 34 are each independently a monovalent group. n33 and n34 are each independently an integer of 0 to 4. When n33 is an integer of 2 to 4, R 33 may be the same or different. When n34 is an integer of 2 to 4, R 34 may be the same or different. * indicates a bond.)

[0091] X in formula (1) 0 is a divalent group containing two benzene rings, Z 01 and X 34 The bonding position of Z to the benzene ring is not limited. 01and X 34 The bonding position of may be any of the ortho, meta and para positions. 02 and X 34 The bonding position of Z to the benzene ring is not limited. 02 and X 34 The bonding position may be any of the ortho, meta and para positions.

[0092] X in formula (2) 1 is a divalent group containing two benzene rings, Z 11 and X 34 The bonding position of Z to the benzene ring is not limited. 11 and X 34 The bonding position of may be any of the ortho, meta and para positions. 12 and X 34 The bonding position of Z to the benzene ring is not limited. 12 and X 34 The bonding position may be any of the ortho, meta and para positions.

[0093] (X 31 , X 32 , X 33 ) X in formula (5) 31 , X 32 , X 33 are each independently a divalent group, and are not particularly limited, but an example thereof is a hydrocarbon group which may have a substituent. 21 , X 22 is the same as:

[0094] (X 34 ) X in formula (6) 34 is not particularly limited as long as it is a divalent group, but an example thereof is a hydrocarbon group which may have a substituent. The hydrocarbon group is the X in the above formula (3). 21 , X 22 is the same as:

[0095] (R31 , R 32 ) R in formula (5) 31 , R 32 is not particularly limited as long as it is a monovalent group, but examples thereof include a halogen group and a hydrocarbon group which may have a substituent. The halogen group and the hydrocarbon group which may have a substituent are each represented by R in the above formula (3). 21 is the same as:

[0096] (R 33 , R 34 ) R in formula (6) 33 , R 34 is not particularly limited as long as it is a monovalent group, but examples thereof include a halogen group and a hydrocarbon group which may have a substituent. The halogen group and the hydrocarbon group which may have a substituent are each represented by R in the above formula (3). 21 is the same as:

[0097] (Y 01 , Y 02 ) Y in formula (1) 01 , Y 02 are each independently, for example, a hydrogen group (-H), a hydroxy group (-OH), a halogen group (-X), a carboxy group (-COOH), an ester group (-COOR), or a hydrocarbon group which may have a substituent.

[0098] The halogen group is, for example, a fluorine group (--F), a chlorine group (--Cl), a bromine group (--Br), or an iodine group (--I).

[0099] The hydrocarbon group which may have a substituent has, for example, 1 to 15 carbon atoms, 1 to 13 carbon atoms, 1 to 12 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 3 carbon atoms.

[0100] Examples of the substituent that the hydrocarbon group may have include a halogen group (e.g., a fluorine group) or an alkyl group having a halogen group (e.g., a fluorine group), etc. The hydrocarbon group that may have a substituent may be one in which some of the carbon atoms of the hydrocarbon group (e.g., some of the carbon atoms contained in the main chain of the hydrocarbon group) are substituted with an element such as oxygen.

[0101] In formula (1), (Y01 ) n01 and / or (Y 02 ) n02 It is preferred that one of the groups Y is a hydroxy group (—OH). 01 ) n01 and / or (Y 02 ) n02 When one of the groups is a hydroxy group (—OH), the display quality and light resistance can be improved.

[0102] (Y 11 , Y 12 , Y 13 , Y 14 In formula (2), Y relative to the benzene ring 11 and Y 12 The bonding position of Y to the benzene ring is not limited. 11 and Y 12 The bonding position of Y may be any of the ortho, meta and para positions. 13 and Y 14 The bonding position of Y to the benzene ring is not limited. 13 and Y 14 The bonding position of Y to one benzene may be any of the ortho, meta and para positions. 11 and Y 12 and the bonding position of Y to the other benzene 13 and Y 14 may be the same as or different from the binding position of

[0103] Y in formula (2) 11 , Y 12 , Y 13 , Y 14 are each independently, for example, a hydrogen group (-H), a hydroxy group (-OH), a halogen group, a carboxy group (-COOH), an ester group (-COOR), or a hydrocarbon group which may have a substituent. The halogen group and the hydrocarbon group which may have a substituent are each represented by Y 01 , Y 02 is the same as:

[0104] In formula (2), Y 11 and / or Y 13 is preferably a hydroxy group (—OH). 11 and / or Y 13 When the group is a hydroxy group (—OH), the display quality and light resistance can be improved.

[0105] (Z 01 , Z 02 ) Z in formula (1) 01 , Z 02 are each independently, for example, a urea bond (-NHCONH-), an amide bond (-NHCO-, -OCHN-) or a hydrazide bond (-NHCOCONH-). 01 , Z 02 is preferably a urea bond. 01 When Z is an amide bond, the nitrogen contained in the amide bond may be bonded to benzene, or the carbon contained in the amide bond may be bonded to benzene. 02 is an amide bond, the nitrogen contained in the amide bond may be bonded to benzene, or the carbon contained in the amide bond may be bonded to benzene.

[0106] (Z 11 , Z 12 ) Z in formula (2) 11 , Z 12 are each independently, for example, a urea bond (-NHCONH-), an amide bond (-NHCO-, -OCHN-) or a hydrazide bond (-NHCOCONH-). 11 , Z 12 is preferably a urea bond. 11 When Z is an amide bond, the nitrogen contained in the amide bond may be bonded to benzene, or the carbon contained in the amide bond may be bonded to benzene. 12 is an amide bond, the nitrogen contained in the amide bond may be bonded to benzene, or the carbon contained in the amide bond may be bonded to benzene.

[0107] (Specific examples of color developers) X in formula (1) 0 and X in formula (2) 1 Specifically, the color developer containing one benzene ring includes at least one selected from the group consisting of compounds represented by the following formulas (7-1) to (7-6).

[0108] X in formula (1) 0 and X in formula (2) 1 Specifically, the color developer containing two benzene rings includes at least one selected from the group consisting of compounds represented by the following formulas (8-1) to (8-8).

[0109] (First photothermal conversion agent, second photothermal conversion agent, third photothermal conversion agent) The first photothermal conversion agent, second photothermal conversion agent, and third photothermal conversion agent are capable of absorbing light in a predetermined wavelength range, such as the near-infrared region, and generating heat. The first photothermal conversion agent, second photothermal conversion agent, and third photothermal conversion agent have different absorption wavelength peaks. Specifically, the first photothermal conversion agent has an absorption wavelength peak at approximately λ １ The second photothermal conversion agent has an absorption wavelength peak at about wavelength λ ２ The third photothermal conversion agent has an absorption wavelength peak at about wavelength λ ３ It has an absorption wavelength peak at wavelength λ １ , λ ２ , λ ３are different from each other. The absorption wavelength peak is preferably in the near-infrared region. The near-infrared region is, for example, a wavelength range of 750 nm or more and 2000 nm or less. As described above, the first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent have different absorption wavelength peaks, so that a desired layer among the recording layers 13A, 13B, and 13C can be selectively colored by irradiation with laser light. It is preferable to use a near-infrared light-absorbing dye that has almost no absorption in the visible region as the first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent. Furthermore, it is preferable that the first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent have excellent light resistance and heat resistance. Note that excellent light resistance here means that the agent will not decompose under the usage environment, for example, when irradiated with light from a fluorescent lamp. Excellent heat resistance means that, for example, when the film is formed together with a polymer material and stored at 150° C. for 30 minutes, the maximum absorption peak value of the absorption spectrum does not change by 20% or more.

[0110] The first photothermal conversion agent, the second photothermal conversion agent, and the third photothermal conversion agent each independently include at least one selected from the group consisting of, for example, compounds having a phthalocyanine skeleton (phthalocyanine dyes), compounds having a squarylium skeleton (squarylium dyes), and inorganic compounds.

[0111] The inorganic compound includes at least one selected from the group consisting of, for example, metal complexes such as dithio complexes, diimonium salts, aminium salts, graphite, carbon black, metal powder particles, metal oxides such as tricobalt tetroxide, iron oxide, chromium oxide, copper oxide, titanium black, and ITO (indium tin oxide), metal nitrides such as niobium nitride, metal carbides such as tantalum carbide, metal sulfides, and various magnetic powders. In addition, the inorganic compound may include a compound (cyanine dye) having a cyanine skeleton with excellent light resistance and heat resistance. Examples of such compounds having a cyanine skeleton include, for example, SbF ６ , P.F. ６ , B.F. ４ , ClO ４ , C.F. ３ SO ３ and (CF３ SO ３ ) ２ Examples of suitable compounds include those having at least one of a counter ion of N and a methine chain containing a five-membered ring or a six-membered ring. In the first embodiment, the compound having a cyanine skeleton used in the recording medium 10 preferably has both one of the counter ions and a cyclic structure such as a five-membered ring or a six-membered ring in the methine chain, but sufficient light resistance and heat resistance are ensured if it has at least one of them. Among these, phthalocyanine dyes are preferred as near-infrared absorbing dyes that combine particularly excellent light resistance and heat resistance and have almost no absorption in the visible region. Because phthalocyanine dyes have a skeleton with little risk of decomposition and a steep absorption peak, they can impart the desired characteristics to the recording layer 13 at a minimum concentration.

[0112] (First matrix resin, second matrix resin, third matrix resin) The first matrix resin, second matrix resin, and third matrix resin preferably function as a binder. The first matrix resin is preferably one in which the first color former, first color developer, and first photothermal conversion agent are easily and homogeneously dispersed. The second matrix resin is preferably one in which the second color former, second color developer, and second photothermal conversion agent are easily and homogeneously dispersed. The third matrix resin is preferably one in which the third color former, third color developer, and third photothermal conversion agent are easily and homogeneously dispersed. The first matrix resin, second matrix resin, and third matrix resin may be of the same type, or may be of different types.

[0113] The first matrix resin, the second matrix resin, and the third matrix resin each independently contain at least one resin selected from the group consisting of, for example, thermosetting resins and thermoplastic resins. The first matrix resin, the second matrix resin, and the third matrix resin preferably contain a polycarbonate-based resin. By including the first matrix resin, the second matrix resin, and the third matrix resin in the polycarbonate-based resin, the light resistance of the background of the recording medium 10 can be improved. Here, a polycarbonate-based resin is a resin having at least a carbonate group (—O—(C═O)—O—) as a structural unit in the main chain. Therefore, the main chain may contain other structural units in addition to the carbonate group.

[0114] The first matrix resin, the second matrix resin, and the third matrix resin may each independently contain, instead of or together with the polycarbonate-based resin, at least one selected from the group consisting of polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethyl cellulose, polystyrene, styrene-based copolymer, phenoxy resin, polyester, aromatic polyester, polyurethane, polyacrylic acid ester, polymethacrylic acid ester, acrylic acid-based copolymer, maleic acid-based polymer, polyvinyl alcohol, modified polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, starch, and the like.

[0115] (Additives) The recording layers 13A, 13B, and 13C may further contain, as necessary, at least one additive selected from the group consisting of a sensitizer, an ultraviolet absorber, etc. From the viewpoint of suppressing coloration of the background, the recording layers 13A, 13B, and 13C preferably contain an amine compound.

[0116] When the recording layers 13A, 13B, and 13C contain an amine compound, it is preferable that the recording layers 13A, 13B, and 13C contain, together with the amine compound, at least one compound selected from the group consisting of epoxy compounds and carbodiimide compounds. If the recording layers 13A, 13B, and 13C contain an amine compound, there is a risk that the reliability of the color-forming portion will decrease during storage at high temperature and high humidity. However, if the recording layers 13A, 13B, and 13C contain, together with the amine compound, at least one compound selected from the group consisting of epoxy compounds and carbodiimide compounds, it is possible to suppress the decrease in reliability of the color-forming portion during storage at high temperature and high humidity caused by the amine compound.

[0117] (Intermediate layer 12A, intermediate layer 12B, intermediate layer 12C, intermediate layer 12D) The intermediate layer 12A is provided between the substrate 11 and the recording layer 13A. The intermediate layer 12A can provide heat insulation between the substrate 11 and the recording layer 13A and can suppress diffusion of the constituent materials between the substrate 11 and the recording layer 13A. The intermediate layer 12B is provided between the recording layer 13A and the recording layer 13B. The intermediate layer 12B can provide heat insulation between the recording layer 13A and the recording layer 13B and can suppress diffusion of the constituent materials between the recording layer 13A and the recording layer 13B. The intermediate layer 12C is provided between the recording layer 13B and the recording layer 13C. The intermediate layer 12C can provide heat insulation between the recording layer 13B and the recording layer 13C and can suppress diffusion of the constituent materials between the recording layer 13B and the recording layer 13C. The intermediate layer 12D is provided between the recording layer 13C and the cover layer 14. The intermediate layer 12D can provide heat insulation between the recording layer 13C and the cover layer 14, and can also suppress diffusion of the constituent materials between the recording layer 13C and the cover layer 14.

[0118] The intermediate layers 12A, 12B, 12C, and 12D are configured to transmit visible light and near-infrared light. The thicknesses of the intermediate layers 12A, 12B, 12C, and 12D are each independently preferably 3 μm to 100 μm, more preferably 5 μm to 50 μm. When the thicknesses of the intermediate layers 12A, 12B, 12C, and 12D are 3 μm or greater, sufficient heat insulating effects and sufficient diffusion suppression effects can be achieved. On the other hand, when the thicknesses of the intermediate layers 12A, 12B, 12C, and 12D are 100 μm or less, the transmittance of visible light and near-infrared light can be improved. Furthermore, the bending resistance of the recording medium 10 can be suppressed from decreasing, making defects such as cracks less likely to occur. The thicknesses of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D may be the same or different from each other.

[0119] The intermediate layer 12A is an adhesive layer 12A. １ and the ultraviolet curing resin layer 12A. ２ and the adhesive layer 12A are provided in this order on the substrate 11. １ The substrate 11 and the ultraviolet curable resin layer 12A ２ The adhesive layer 12A is adhered to the substrate. １ The ultraviolet curing resin layer 12A may be capable of insulating the space between the substrate 11 and the recording layer 13A. ２ The adhesive layer 12A can insulate the space between the substrate 11 and the recording layer 13A and can suppress the diffusion of constituent materials (for example, the first color former and the like) between the substrate 11 and the recording layer 13A. １ and the ultraviolet curing resin layer 12A ２ The order of lamination of these layers is not limited to the above example, and the order of lamination of these layers may be reversed from the above order of lamination.

[0120] The intermediate layer 12B is an adhesive layer 12B １ and the ultraviolet curing resin layer 12B. ２ The adhesive layer 12B is provided on the recording layer 13A in this order. １ The recording layer 13A and the ultraviolet curing resin layer 12B ２ Adhesive layer 12B １The ultraviolet curing resin layer 12B may be capable of insulating the space between the recording layer 13A and the recording layer 13B. ２ The adhesive layer 12B can insulate the space between the recording layers 13A and 13B and can suppress the diffusion of constituent materials (e.g., the first color former, the second color former, etc.) between the recording layers 13A and 13B. １ and the ultraviolet curing resin layer 12B ２ The order of lamination of these layers is not limited to the above example, and the order of lamination of these layers may be reversed from the above order of lamination.

[0121] The intermediate layer 12C is an adhesive layer 12C. １ and the ultraviolet curing resin layer 12C. ２ and the adhesive layer 12C are provided on the recording layer 13B in this order. １ The recording layer 13B and the ultraviolet curing resin layer 12C ２ Adhesive layer 12C １ The ultraviolet curing resin layer 12C may be capable of insulating the space between the recording layer 13B and the recording layer 13C. ２ The adhesive layer 12C can insulate the space between the recording layer 13B and the recording layer 13C and can suppress the diffusion of the constituent materials (for example, the second and third color formers) between the recording layer 13B and the recording layer 13C. １ and the ultraviolet curing resin layer 12C ２ The order of lamination of these layers is not limited to the above example, and the order of lamination of these layers may be reversed from the above order of lamination.

[0122] The intermediate layer 12D is an adhesive layer 12D １ and the ultraviolet curing resin layer 12D. ２ and an adhesive layer 12D are provided on the recording layer 13C in this order. １ The recording layer 13C and the ultraviolet curing resin layer 12D ２ Adhesive layer 12D １ The ultraviolet curing resin layer 12D may be capable of insulating the space between the recording layer 13C and the cover layer 14. ２ The adhesive layer 12D can insulate the space between the recording layer 13C and the cover layer 14 and can suppress the diffusion of constituent materials (for example, the third color former, etc.) between the recording layer 13C and the cover layer 14. １and the ultraviolet curing resin layer 12D ２ The order of lamination of these layers is not limited to the above example, and the order of lamination of these layers may be reversed from the above order of lamination.

[0123] Adhesive layer 12A １ , adhesive layer 12B １ , adhesive layer 12C １ and adhesive layer 12D １ is, for example, a double-sided adhesive film such as OCA (Optical Clear Adhesive).

[0124] Ultraviolet curing resin layer 12A ２ , ultraviolet curing resin layer 12B ２ , ultraviolet curing resin layer 12C ２ and the ultraviolet curing resin layer 12D ２ The ultraviolet curable resin layer 12A includes a polymerized and solidified ultraviolet curable resin. ２ , ultraviolet curing resin layer 12B ２ , ultraviolet curing resin layer 12C ２ and the ultraviolet curing resin layer 12D ２ The ultraviolet-curable resin layer 12A includes a polymer of a polymerizable compound and a polymer that has undergone a structural change due to the generation of active species by a polymerization initiator upon irradiation with external energy (ultraviolet rays). The ultraviolet-curable resin composition includes, for example, at least one selected from the group consisting of radical polymerization type ultraviolet-curable resin compositions and cationic polymerization type ultraviolet-curable resin compositions. The ultraviolet-curable resin composition may optionally include at least one selected from the group consisting of a sensitizer, a filler, a stabilizer, a leveling agent, an antifoaming agent, a viscosity adjuster, and the like. ２ , ultraviolet curing resin layer 12B ２ , ultraviolet curing resin layer 12C ２ and the ultraviolet curing resin layer 12D ２ The ultraviolet curing resin layer 12D is provided as needed and does not have to be provided. ２ may have a function of blocking ultraviolet light caused by thermal curing.

[0125] (Cover layer 14) The cover layer 14 covers the upper surface of the recording medium 10 (the surface opposite to the substrate 11). The cover layer 14 is configured to be able to transmit visible light and near-infrared light. The cover layer 14 is, for example, a film. The cover layer 14 includes, for example, a polymer resin. Examples of the polymer resin include the same materials as those used for the light transmission layer 22. The cover layer 14 may include additives as needed.

[0126] [1.3 Method for Manufacturing Passport] Next, an example of a method for manufacturing the passport 20 according to the first embodiment of the present disclosure will be described.

[0127] First, the recording medium 10 is fabricated by laminating the substrate 11, intermediate layer 12A, recording layer 13A, intermediate layer 12B, recording layer 13B, intermediate layer 12C, recording layer 13C, intermediate layer 12D, and cover layer 14. Next, the protective layer 24, diffuse reflective layer 21, light-transmitting layer 22, recording medium 10, and protective layer 23 are laminated to form a laminate. Next, the laminate is sandwiched between metal plates and heated and pressurized to heat-seal the layers of the laminate. This results in a personal information page 20A. The temperature applied to the laminate during heat-sealing is preferably 130°C or higher and 200°C or lower. A temperature of 130°C or higher can achieve sufficient fusion strength. On the other hand, a temperature of 200°C or lower can reduce damage to the recording medium 10. Next, the personal information page 20A and other pages 20A obtained as described above are sandwiched between the front cover 201 and the back cover 202 and bound. In this way, the desired passport 20 is obtained.

[0128] From the viewpoint of improving the total light reflectance of the imaged and unimaged areas, it is preferable that each layer provided above the diffuse reflective layer 21 has a high transmittance to near-infrared light with a wavelength of 1080 nm and does not whiten during thermocompression bonding. To ensure adhesion between the diffuse reflective layer 21 and the layer adjacent to the diffuse reflective layer 21 (for example, the light transmitting layer 22, the substrate 11, or the recording layer 13A), it is preferable to select materials that are highly compatible with each other or that have the same or the same type of base material.

[0129] [1.4 Passport Drawing Method] In the passport 20 having the above configuration, for example, personal information such as a photograph 20P can be recorded on the personal information page 20A as follows. Here, an example will be described in which the recording layers 13A, 13B, and 13C are magenta, cyan, and yellow, respectively.

[0130] The recording layer 13A is colored magenta as follows: When a peak wavelength λ is applied to a predetermined position on the recording layer 13A, １ When the near-infrared laser beam is irradiated, the first photothermal conversion agent contained in the irradiated area absorbs the near-infrared laser beam and generates heat. This heat melts the first color developer, causing a color reaction (color-forming reaction) between the first color developer and the first color former, causing the irradiated area to develop a magenta color.

[0131] The recording layer 13B is colored cyan as follows: When a peak wavelength λ is applied to a predetermined position on the recording layer 13B, ２ When the near-infrared laser beam is irradiated, the portion irradiated with the laser beam develops a cyan color due to the same reaction as that of the recording layer 13A.

[0132] The recording layer 13C is colored yellow as follows: When a peak wavelength λ is applied to a predetermined position of the recording layer 13B, ３ When the near-infrared laser beam is irradiated, the portion irradiated with the laser beam develops yellow color due to the same reaction as that of the recording layer 13A.

[0133] As described above, predetermined positions of the recording layers 13A, 13B, and 13C are colored magenta, cyan, and yellow, respectively, so that a desired full-color image is drawn on the recording medium 10.

[0134] [1.5 Effects] As described above, the passport 20 according to the first embodiment includes a diffuse reflective layer 21 below the recording medium 10. This allows near-infrared light diffusely reflected by the diffuse reflective layer 21 to be used for drawing on the recording medium 10. Furthermore, the total light reflectance of the page 20A (the total light reflectance of the drawn and undrawn portions of the page 20A) for near-infrared light with a wavelength of 1080 nm incident on the diffuse reflective layer 21 from the recording medium 10 side is 93.0% or higher. This suppresses light absorption in the light-transmitting layer 22 between the diffuse reflective layer 21 and the recording medium 10, thereby increasing the amount of diffusely reflected light incident on the drawn portion of the recording medium 10 via the light-transmitting layer 22, etc. This improves the recording sensitivity of the recording medium 10, particularly the recording sensitivity of the recording layer 13A furthest from the light incident surface of the page 20A, thereby improving the drawing speed of the passport 20. This shortens the time required to issue a passport 20. For example, a passport issuance speed of 120 passes per hour can be achieved.

[0135] By providing the recording medium 10 with the diffuse reflective layer 21 and the light-transmitting layer 22, at least one of members and components can be included in the diffuse reflective layer 21 and the light-transmitting layer 22. At least one of members and components can also be provided between the diffuse reflective layer 21 and the light-transmitting layer 22. The member may have an optical function other than diffuse reflection and light transmission, or may have a function other than the optical function. The component may be an electronic component such as an IC chip.

[0136] By providing the recording medium 10 with the protective layer 23, at least one of members, parts, etc. can be contained within the protective layer 23. Also, at least one of members, parts, etc. can be provided between the recording medium 10 and the protective layer 23.

[0137] By providing the recording medium 10 with the protective layer 24, at least one of the members, parts, etc. can be contained in the protective layer 24. Also, at least one of the members, parts, etc. can be provided between the diffuse reflection layer 21 and the protective layer 24.

[0138] 2 Second Embodiment [2.1 Configuration of Passport] In the first embodiment, an example was described in which the recording sensitivity of the recording medium 10 is improved and the drawing speed is improved by limiting the numerical range of the total light reflectance. In contrast, in the second embodiment, an example is described in which the recording sensitivity of the recording medium 10 is improved and the drawing speed is improved by limiting the distance between the recording layer 13A and the diffuse reflective layer 21, instead of limiting the numerical range of the total light reflectance. Note that, from the perspective of improving the recording sensitivity of the recording medium 10, it is preferable to limit both the numerical range of the total light reflectance and the distance between the recording layer 13A and the diffuse reflective layer 21.

[0139] (Distance between the recording layer 13A and the diffuse reflective layer 21) The distance D between the recording layer 13A, which is the closest of the three recording layers 13A, 13B, and 13C to the diffuse reflective layer 21, and the diffuse reflective layer 21 is less than 150 μm, preferably 100 μm or less, more preferably 50 μm, and even more preferably 0 μm. Note that FIGS. 2, 4A, and 4B show an example in which the recording layer 13A and the light transmitting layer 22 are adjacent to each other, and the distance D between the recording layer 13A and the diffuse reflective layer 21 is the same as the thickness of the light transmitting layer 22. As shown in FIG. 3, when a substrate 11 and an intermediate layer 12A are provided between the recording layer 13A and the light transmitting layer 22, the distance D between the recording layer 13A and the diffuse reflective layer 21 is the same as the sum of the thickness of the light transmitting layer 22, the thickness of the substrate 11, and the thickness of the intermediate layer 12A.

[0140] 4A, when the distance D between the diffuse reflection layer 21 and the recording layer 13A is short, the diffusely reflected light by the diffuse reflection layer 21 is prevented from diffusing beyond the imaged portion of the recording layer 13A, thereby increasing the amount of diffusely reflected light L incident on the imaged portion. This improves the recording sensitivity of the recording layer 13A, particularly the recording sensitivity of the recording layer 13A furthest from the light incident surface of the page 20A, thereby improving the imaged portion speed of the passport 20. This shortens the time required to issue the passport 20.

[0141] 4B, if the distance D between the diffuse reflection layer 21 and the recording layer 13A is large, the diffusely reflected light from the diffuse reflection layer 21 spreads to areas other than the imaged portion of the recording layer 13A, reducing the amount of diffusely reflected light L incident on the imaged portion. This reduces the recording sensitivity of the recording medium 10, particularly the recording sensitivity of the recording layer 13A furthest from the light incident surface of the page 20A, slowing down the imaged portion and increasing the time required to issue the passport 20.

[0142] In the above explanation, an example has been described in which the recording sensitivity is improved and the writing speed is improved by taking as an example the recording layer 13A, which is the layer that is most likely to lose its recording sensitivity among the recording layers 13A, 13B, and 13C. However, the effect of improving the recording sensitivity by limiting the range of the distance D is not limited to the recording layer 13A, and it is also possible to improve the recording sensitivity of the recording layers 13B and 13C by limiting the range of the distance D.

[0143] The distance D can be determined as follows: The cross section of the recording medium 10 is exposed by polishing the page 20A with a microtome or the like. Next, the exposed cross section is observed with an optical microscope equipped with a dimension measurement function to measure the distance D between the recording layer 13A closest to the diffuse reflective layer 21 and the diffuse reflective layer 21. The measurement may be performed on either an unprinted portion or a printed portion of the recording medium 10, but observing the printed portion makes it easier to identify the recording layer 13A, and thus the distance D can be easily measured. If it is not easy to measure the distance D with an optical microscope, it is also possible to observe the cross section of the recording medium 10 with the optical microscope, locate the recording layer 13A and the diffuse reflective layer 21, and then measure the distance D with a scanning electron microscope.

[0144] (Distance between recording layer 13B and diffuse reflective layer 21) The distance between the recording layer 13B, which is the second closest to the diffuse reflective layer 21 among the three recording layers 13A, 13B, and 13C, and the diffuse reflective layer 21 is preferably less than 123 μm, more preferably 73 μm or less, and even more preferably 23 μm or less. The distance between the recording layer 13B and the diffuse reflective layer 21 is determined in the same manner as the distance D between the recording layer 13A and the diffuse reflective layer 21.

[0145] (Distance between recording layer 13C and diffuse reflective layer 21) The distance between the recording layer 13C, which is the third closest to the diffuse reflective layer 21 among the three recording layers 13A, 13B, and 13C, and the diffuse reflective layer 21 is preferably less than 146 μm, more preferably 96 μm or less, and even more preferably 46 μm or less. The distance between the recording layer 13C and the diffuse reflective layer 21 is determined in the same manner as the distance D between the recording layer 13A and the diffuse reflective layer 21.

[0146] [2.2 Effects] As described above, the passport 20 according to the second embodiment includes a diffuse reflective layer 21 below the recording medium 10. This allows near-infrared light diffusely reflected by the diffuse reflective layer 21 to be used for drawing on the recording medium 10. Furthermore, the distance D between the recording layer 13A, which is closest to the diffuse reflective layer 21 among the three recording layers 13A, 13B, and 13C, and the diffuse reflective layer 21 is less than 150 μm. This prevents the diffusely reflected light from the diffuse reflective layer 21 from spreading beyond the drawing area of ​​the recording layer 13A, thereby increasing the amount of diffusely reflected light L incident on the drawing area. This improves the recording sensitivity of the recording medium 10, particularly the recording sensitivity of the recording layer 13A furthest from the light incident surface of the page 20A, thereby improving the drawing speed of the passport 20. This shortens the time required to issue a passport 20. For example, a passport issuance speed of 120 passes per hour can be achieved.

[0147] <3 Modifications> [Modification 1] As shown in Fig. 5, page 20A may include, instead of recording medium 10 (see Fig. 2), a storage layer 25 including recording medium 10 between light transmitting layer 22 and protective layer 23. Light transmitting layer 22 and storage layer 25 may be bonded together by fusion or adhesive. Storage layer 25 and protective layer 23 may be bonded together by fusion or adhesive.

[0148] The accommodation layer 25 has an accommodation portion 25A for accommodating the recording medium 10. The accommodation portion 25A is provided in a portion of the surface of the accommodation layer 25. This portion may be a location corresponding to the photograph 20P. The accommodation portion 25A may be a through-hole that penetrates the accommodation layer 25 in the thickness direction. The accommodation layer 25 is intended to suppress a step formed by the recording medium 10 when the recording medium 10 is sandwiched between the diffuse reflection layer 21 and the protective layer 23. The accommodation layer 25 has approximately the same thickness as the recording medium 10, and covers one surface of the light transmission layer 22 except for the area where the recording medium 10 is provided.

[0149] The encasing layer 25 has a film shape. The encasing layer 25 may be configured to be transparent to visible light, or may be configured to be transparent to both visible light and near-infrared light. The encasing layer 25 includes, for example, a polymer resin. Examples of the polymer resin include the same materials as those of the light-transmitting layer 22.

[0150] [Variation 2] In Variation 1, an example has been described in which the accommodation portion 25A is a through-hole that penetrates the accommodation layer 25 in the thickness direction. However, the configuration of the accommodation portion 25A is not limited to this example, and for example, as shown in Fig. 6, the accommodation portion 25A may be a recess with a bottom that is recessed in the thickness direction of the accommodation layer 25. In this case, the recess may be provided on one of both surfaces of the accommodation layer 25 that faces the protective layer 23, or on the other surface that faces the light-transmitting layer 22.

[0151] [Variation 3] As shown in Fig. 7, the page 20A may include a frame 26 that covers the side surface of the recording medium 10. The frame 26 can protect the side surface of the recording medium 10. The frame 26 is provided between the peripheral edge of one surface of the light-transmitting layer 22 and the peripheral edge of one surface of the protective layer 23. The light-transmitting layer 22 and the frame 26 may be bonded together by fusion or adhesive. The frame 26 and the protective layer 23 may be bonded together by fusion or adhesive.

[0152] It is preferable that the thickness of the frame 26 and the recording medium 10 are approximately the same. This makes it possible to prevent a step from occurring at the boundary between the frame 26 and the recording medium 10 when the side surface of the recording medium 10 is covered with the frame 26.

[0153] The frame 26 may be configured to be able to transmit visible light. The frame 26 includes, for example, a polymer resin. Examples of the polymer resin include the same materials as those of the light-transmitting layer 22.

[0154] [Variation 4] In the first embodiment, an example has been described in which the page 20A includes the light-transmitting layer 22 between the diffuse reflective layer 21 and the recording medium 10 (see FIG. 2). However, the configuration of the page 20A, which is a laminate, is not limited to this example. For example, as shown in FIG. 8, the page 20A may not include the light-transmitting layer 22 between the diffuse reflective layer 21 and the recording medium 10, and the diffuse reflective layer 21 and the recording medium 10 may be adjacent to each other. In this case, the diffuse reflective layer 21 and the recording medium 10 may be bonded together by fusion or adhesive.

[0155] When the diffuse reflective layer 21 and the recording medium 10 are adjacent to each other, the substrate 11 and the intermediate layer 12A may be provided between the recording layer 13A, which is the closest of the three recording layers 13A, 13B, and 13C to the diffuse reflective layer 21, and the diffuse reflective layer 21. When the substrate 11 and the intermediate layer 12A are provided between the recording layer 13A and the diffuse reflective layer 21, the distance D between the recording layer 13A and the diffuse reflective layer 21 is the sum of the thickness of the substrate 11 and the thickness of the intermediate layer 12A.

[0156] [Variation 5] In the first embodiment, an example was described in which the light-transmitting layer 22 and the recording medium 10 are bonded together by fusion, and the recording medium 10 and the protective layer 23 are bonded together by fusion. However, the configuration of the laminated page 20A is not limited to this example. For example, as shown in FIG. 9 , an attachment layer 27 may be provided between the light-transmitting layer 22 and the recording medium 10, and the light-transmitting layer 22 and the recording medium 10 may be bonded together by the attachment layer 27. Alternatively, an attachment layer 28 may be provided between the recording medium 10 and the protective layer 23, and the recording medium 10 and the protective layer 23 may be bonded together by the attachment layer 28. Note that either the light-transmitting layer 22 and the recording medium 10 or the recording medium 10 and the protective layer 23 may be bonded together by an attachment layer. The attachment layer 28 is configured to transmit visible light and near-infrared light. The attachment layer 28 is, for example, an adhesive layer or a sticky layer.

[0157] [Variation 6] The light transmitting layer 22 may have a single layer structure or a multi-layer structure of two or more layers. The light transmitting layer 22 having a single layer structure may be a coating layer or an adhesive layer in addition to the film described in the first embodiment. The coating layer is, for example, an ultraviolet-curable resin layer. A hard coating layer may also be used as the coating layer. The adhesive layer is, for example, an adhesive layer or a pressure-sensitive adhesive layer.

[0158] The light transmitting layer 22 having a multilayer structure includes, for example, a film 221 and an attachment layer 222, as shown in Fig. 10. Fig. 10 shows an example in which the attachment layer 222 is provided between the film 221 and the recording medium 10, but the attachment layer 222 may also be provided between the diffuse reflection layer 21 and the film 221. The attachment layer 222 is, for example, an adhesive layer or a bonding layer.

[0159] [Variation 7] As shown in FIG. 11A, a page 20A has a hole 20H below the recording medium 10. １ The hole 20H may have the following structure. １ The hole 20H may penetrate the protective layer 24, the diffuse reflection layer 21, and the light transmission layer 22. １ Inside, filler 20I １ Filler 20I may be filled. １ is the hole 20H １ The filling material 20I may be fitted to the １ The filler 20I includes, for example, at least one of a polymer resin and an inorganic material. １ When the inorganic material contains both a polymer resin and an inorganic material, the inorganic material may be dispersed in the polymer resin, or a first layer containing the polymer resin and a second layer containing the inorganic material may be laminated. The inorganic material includes, for example, a metal.

[0160] Filling 20I １ The filler 20I may be configured to be able to transmit visible light, or may not be configured to be able to transmit visible light. １ The filler 20I may be configured to be able to transmit both visible light and near-infrared light, or may not be configured to be able to transmit both visible light and near-infrared light. １Therefore, even if there is a portion under the recording medium 10 where the diffuse reflection layer 21 is not present, it is possible to draw on the recording medium 10. １ may have a pattern or the like on at least one of its surface and inside.

[0161] [Modification 8] In Modification 7, the hole 20H １ The above description is directed to an example in which the hole 20H penetrates the protective layer 24, the diffuse reflection layer 21, and the light transmission layer 22. However, １ The configuration of the hole 20H is not limited to this example. １ the upper end side and the hole 20H １ 11B, one or both of the lower ends of the hole 20H may be closed. １ The upper end side of the hole 20H is closed by the light transmitting layer 22. １ The lower end of the filler 20I may be closed by a protective layer 24. １ may be, for example, a transparent substrate that is transparent to visible light.

[0162] [Modification 9] As shown in FIG. 12A, the page 20A has a hole 20H at a location different from the location where the recording medium 10 is provided in a plan view. ２ The hole 20H may have the following structure. ２ The hole 20H may penetrate the recording medium 10. ２ The hole 20H may penetrate the protective layer 24, the diffuse reflection layer 21, the light transmission layer 22, the accommodating layer 25, and the protective layer 23. ２ Inside, filler 20I ２ Filler 20I may be filled. ２ is the hole 20H ２ The filling material 20I may be fitted to the ２ The filler 20I includes, for example, at least one of a polymer resin and an inorganic material. ２ When the inorganic material contains both a polymer resin and an inorganic material, the inorganic material may be dispersed in the polymer resin, or a first layer containing the polymer resin and a second layer containing the inorganic material may be laminated. The inorganic material includes, for example, a metal.

[0163] Filling 20I ２ The filler 20I may be configured to be able to transmit visible light, or may not be configured to be able to transmit visible light. ２ The filler 20I may be configured to be able to transmit both visible light and near-infrared light, or may not be configured to be able to transmit both visible light and near-infrared light. ２ As shown in FIG. 12B, the filler 20I may have a layer structure different from that of the recording medium 10 (for example, a single layer structure), or may have the same layer structure as that of the recording medium 10, as shown in FIG. 12B. ２ may have a pattern or the like on at least one of its surface and inside.

[0164] [Modification 10] In the first embodiment, an example has been described in which the intermediate layers 12A, 12B, 12C, and 12D each include an adhesive layer and an ultraviolet-curable resin layer. However, the configurations of the intermediate layers 12A, 12B, 12C, and 12D are not limited to this, and may be, for example, the configurations described below.

[0165] 13 is a cross-sectional view of a first modified example of the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D. ２ and the recording layer 13A. ３ In this case, adhesiveness is imparted to both sides of the intermediate layer 12A, so that the adhesion between the substrate 11 and the recording layer 13A can be improved. ２ and the adhesive layer 12B between the recording layer 13B. ３ In this case, adhesiveness is imparted to both sides of the intermediate layer 12B, so that the adhesion between the recording layer 13A and the recording layer 13B can be improved. ２ and the recording layer 13C. ３ In this case, adhesiveness is imparted to both sides of the intermediate layer 12C, so that the adhesion between the recording layer 13B and the recording layer 13C can be improved. ２and the cover layer 14. ３ In this case, adhesiveness is imparted to both sides of the intermediate layer 12D, so that the adhesion between the recording layer 13C and the cover layer 14 can be improved. ３ , adhesive layer 12B ３ , adhesive layer 12C ３ and adhesive layer 12D ３ 1, the recording medium 10 has an adhesive layer 12A. ３ , adhesive layer 12B ３ , adhesive layer 12C ３ and adhesive layer 12D ３ The substrate 11 and the intermediate layer 12A may be omitted as necessary.

[0166] In the page 20A of the passport 20 according to the modification 10, the intermediate layer 12A, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are each an ultraviolet curable resin layer 12A. ２ , ultraviolet curing resin layer 12B ２ , ultraviolet curing resin layer 12C ２ and the ultraviolet curing resin layer 12D ２ This makes it possible to suppress component diffusion between layers via intermediate layer 12A, intermediate layer 12B, intermediate layer 12C, and intermediate layer 12D, thereby suppressing degradation in display quality of page 20A.

[0167] [Variation 11] Figure 14 is a cross-sectional view of a second variation of intermediate layers 12A, 12B, 12C, and 12D. Intermediate layers 12A, 12B, 12C, and 12D may each be formed as an adhesive layer. The adhesive layer may be a thermal adhesive layer. The thermal adhesive layer contains a thermal adhesive resin that softens or melts at a predetermined temperature to bond the layers together. The other components contained in the thermal adhesive layer are not particularly limited. The thermal adhesive resin may be a thermoplastic resin that softens when heated to its softening or melting point. The thermoplastic resin is not particularly limited, but may include at least one selected from the group consisting of polyamide-based resins, polycarbonate-based resins, polyester-based resins, polyethylene-based resins, ethylene-vinyl acetate copolymer (EVA)-based resins, polyurethane-based resins, and acrylic-based resins. The predetermined temperature varies depending on the type of thermoplastic resin used in the thermal adhesive resin. The substrate 11 and intermediate layer 12A may be omitted if necessary.

[0168] In page 20A of passport 20 relating to variant example 11, the substrate 11 and recording layer 13A, the recording layer 13A and recording layer 13B, the recording layer 13B and recording layer 13C, and the recording layer 13C and cover layer 14 are each bonded together by an adhesive layer, thereby improving the adhesion between each of these layers.

[0169] Furthermore, the number of layers constituting the page 20A of the passport 20 according to the modification 11 can be reduced, thereby reducing the material costs and process costs of the passport 20.

[0170] The adhesive layer is not limited to a thermal adhesive layer, but may be, for example, a pressure-sensitive adhesive layer that can be bonded at room temperature. In this case, the layers that make up page 20A can be bonded together at room temperature without using a heat press.

[0171] 14 shows an example in which all of intermediate layers 12A, 12B, 12C, and 12D are formed of adhesive layers, but at least one of intermediate layers 12A, 12B, 12C, and 12D may be formed of an adhesive layer. When all of intermediate layers 12A, 12B, 12C, and 12D are formed of thermal adhesive layers, the layers of recording medium 10 can be bonded together with the thermal adhesive layers.

[0172] [Variation 12] In the first embodiment, an example was described in which the recording medium 10 has three layers: recording layer 13A, recording layer 13B, and recording layer 13C (see FIG. 3 ). However, the layer configuration of the recording medium 10 is not limited to this, and the recording medium 10 may have one, two, or four or more recording layers. When the recording medium 10 has one recording layer, the recording layer may be any one of recording layer 13A, recording layer 13B, and recording layer 13C, or may be a recording layer that can exhibit a color different from these recording layers 13A, 13B, and 13C in a color-developed state, for example, a recording layer that can exhibit black in a color-developed state. When the recording medium 10 has two or four or more recording layers, the color-developed states of the two or four or more recording layers may be different from each other.

[0173] [Variation 13] In the first embodiment, an example was described in which the light-transmitting layer 22, the substrate 11, and the intermediate layer 12A were provided between the recording layer 13A, which is the closest of the three recording layers 13A, 13B, and 13C to the diffuse reflective layer 21, and the diffuse reflective layer 21 (see FIG. 3). However, the configuration of the laminated page 20 is not limited to this example. As shown in FIG. 15, the light-transmitting layer 22, the substrate 11, and the intermediate layer 12A may not be provided between the recording layer 13A and the diffuse reflective layer 21, and the recording layer 13A and the diffuse reflective layer 21 may be adjacent to each other. That is, the recording medium 10 may include the recording layer 13A as the bottom layer, and the recording layer 13A may be adjacent to the diffuse reflective layer 21. In this case, the distance D between the recording layer 13A and the diffuse reflective layer 21 is 0 μm. In Variation 13, as in the first embodiment, the intermediate layer 12D and the cover layer 14 may be adjacent to each other.

[0174] [Variation 14] Variation 13 describes an example in which the recording medium 10 includes a recording layer 13A as the bottom layer. However, the configuration of the recording medium 10 is not limited to this example, and the recording medium 10 may include either an intermediate layer 12A or a substrate 11 below the recording layer 13A. The intermediate layer 12A may be a resin layer containing an ultraviolet-curable resin and polycarbonate. When either the intermediate layer 12A or the substrate 11 is included below the recording layer 13A, the distance D between the recording layer 13A and the diffuse reflective layer 21 is the thickness of either the intermediate layer 12A or the substrate 11. Note that an example in which the recording medium 10 includes both the substrate 11 and the intermediate layer 12A below the recording layer 13A is described in Variation 4.

[0175] Although the example in which the light transmitting layer 22 is not provided has been described in the example in the modification 14, the light transmitting layer 22 may be provided. In this case, the distance D between the recording layer 13A and the diffuse reflective layer 21 is the sum of the thickness of either the intermediate layer 12A or the substrate 11 and the thickness of the light transmitting layer 22.

[0176] [Modification 16] In Modification 13, an example was described in which the intermediate layer 12D and the cover layer 14 are adjacent to each other. However, the configuration of the recording medium 10 is not limited to this example, and as shown in Fig. 16, the recording medium 10 may include a UV protection layer 15 and an adhesive layer 16 between the intermediate layer 12D and the cover layer 14 in order to improve ultraviolet resistance. The UV protection layer 15 may be provided on the intermediate layer 12D side, and the adhesive layer 16 may be provided on the cover layer 14 side.

[0177] The page 20A of the passport 20 having the above-described structure is produced, for example, as follows: First, the UV-cut layer 15 and the ultraviolet-curable resin layer 12D are ２ The first laminated film, the recording layer 13C, and the ultraviolet curable resin layer 12C ２ a second laminated film, a recording layer 13B, and an ultraviolet curable resin layer 12B ２ Next, the adhesive layer 16, the first laminated film, and the adhesive layer 12D are formed on the cover layer 14 as a substrate. １ , second laminated film, adhesive layer 12C １, third laminated film, adhesive layer 12B １ and recording layer 13A are laminated in this order to form recording medium 10. In this process, the first laminate film is arranged so that UV-cut layer 15 faces cover layer 14, the second laminate film is arranged so that recording layer 13C faces the first laminate film, and the third laminate film is arranged so that recording layer 13B faces the second laminate film. A diffuse reflective layer 21 is then placed on recording layer 13A of recording medium 10, and recording medium 10 and diffuse reflective layer 21 are thermocompression-bonded together. Next, if necessary, protective layer 23 and protective layer 24 are thermocompression-bonded to the first and second surfaces of the laminate of recording medium 10 and diffuse reflective layer 21, respectively. In the process of thermocompression-bonding recording medium 10 and diffuse reflective layer 21, protective layer 23 and protective layer 24 may also be thermocompression-bonded to recording medium 10 and diffuse reflective layer 21, respectively.

[0178] In page 20A of passport 20 according to modification 16, the distance D between recording layer 13A and diffuse reflective layer 21 is 0 μm, which makes it possible to prevent diffusely reflected light from diffusely reflecting layer 21 from spreading beyond the imaged portion of recording layer 13A, compared to page 20A of passport 20 according to the second embodiment. This further increases the amount of diffusely reflected light L incident on the imaged portion. This further improves the recording sensitivity of recording medium 10, particularly the recording sensitivity of recording layer 13A furthest from the light incident surface of page 20A, and further improves the imaged portion of passport 20.

[0179] In the page 20A of the passport 20 according to the modification 16, the intermediate layer 12B, the intermediate layer 12C, and the intermediate layer 12D are each an ultraviolet curable resin layer 12B. ２ , ultraviolet curing resin layer 12C ２ and the ultraviolet curing resin layer 12D ２ Therefore, it is possible to suppress the diffusion of components between the layers via the intermediate layers 12B, 12C, and 12D, and therefore it is possible to suppress the deterioration of the display quality of the passport 20.

[0180] In page 20A of passport 20 according to variation 16, diffuse reflective layer 21 and recording layer 13A are fused together, recording layer 13A and recording layer 13B are bonded together by intermediate layer 12B, recording layer 13B and recording layer 13C are bonded together by intermediate layer 12C, recording layer 13C and UV-cut layer 15 are bonded together by intermediate layer 12D, and UV-cut layer 15 and cover layer 14 are bonded together by adhesive layer 16. This ensures adhesion between the layers that make up page 20A.

[0181] As described above, page 20A of passport 20 according to variation 16 is produced by laminating each layer on cover layer 14 as a base material to form recording medium 10, and then thermocompressing recording layer 13A and diffuse reflective layer 21 of recording medium 10. Therefore, it is not necessary to provide intermediate layer 12A or the like (see FIG. 3 ) between recording layer 13A and diffuse reflective layer 21, and page 20A can be made thinner.

[0182] The configuration of the above-described modified example 16 may be applied to the passport 20 according to the first embodiment and the passport 20 according to the second embodiment, etc.

[0183] [Variation 17] From the viewpoint of ease of handling of the recording medium 10, the recording medium 10 may be provided with a release layer 17 on both sides of the recording medium 10 before being incorporated into the page 20A of the passport 20, as shown in FIG. 17 . Hereinafter, a recording medium 10 provided with a release layer 17 on both sides is referred to as a recording medium 10A with a release layer. However, the side on which the release layer 17 is provided is not limited to both sides of the recording medium 10, and may be one side of the recording medium 10. In the case of one side, the release layer 17 is preferably provided on the side of the recording medium 10 facing the recording layer 13A from the viewpoint of protecting the recording layer 13A. The recording medium 10A with a release layer may be a film-like original web wound into a roll. The release layer 17 may also be a film-like original web. The release layer 17 may be peeled off from both sides of the recording medium 10 when the recording medium 10 is incorporated into a laminate such as the page 20A.

[0184] The release layer 17 provided on the recording layer 13A side is configured to be peelable from the recording layer 13A. The release layer 17 provided on the recording layer 13A side can protect the recording layer 13. Specifically, for example, the release layer 17 provided on the recording layer 13A side can suppress the occurrence of scratches, cracks, etc. on the recording layer 13, and the adhesion of dirt, etc. to the recording layer 13.

[0185] The release layer 17 provided on the cover layer 14 side is configured to be peelable from the cover layer 14. The release layer 17 provided on the cover layer 14 side can protect the cover layer 14. Specifically, for example, the release layer 17 provided on the cover layer 14 side can suppress the occurrence of scratches, cracks, etc. on the cover layer 14, and the adhesion of dirt, etc. to the cover layer 14.

[0186] An example of a method for manufacturing a passport 20 using the original roll of the recording medium 10A with a release layer will be described below. First, the film-like recording medium 10A with a release layer is unwound from the original roll and punched into a predetermined size and shape, and then the release layer 17 is peeled off from both sides of the recording medium 10. Next, a passport 20 is obtained in the same manner as in the method for manufacturing a passport 20 according to the first embodiment, except that the recording medium 10 from which the release layer 17 has been peeled off in this manner is used.

[0187] In Modification 17, an example in which the release layer 17 is provided on the recording medium 10 in Modification 16 has been described, but the recording medium 10 on which the release layer 17 is provided is not limited to this example. For example, the release layer 17 may be provided on the recording medium 10 in the first embodiment, the recording medium 10 in the second embodiment, and the recording medium 10 in modifications other than Modification 16.

[0188] [Modification 18] The light transmitting layer 22 or the protective layer 23 may be a recording medium. In this case, the recording medium 10 is the first recording medium, and the recording medium is the second recording medium. Note that a part of the light transmitting layer 22 or the protective layer 23 may be the second recording medium. The second recording medium has a peak wavelength λ ４ Laser light L having ４The laser may be configured to be capable of drawing a monochromatic image (a monochrome image) by the laser. The monochromatic image may be visible under visible light and may be captured by an imaging device under infrared light. The color of the drawn portion of the monochromatic image (the portion irradiated with the laser) may be, for example, black or brown, but is not limited to these colors. Peak wavelength λ ４ The lower limit of the peak wavelength λ is, for example, 1000 nm or more. ４ The upper limit of the peak wavelength λ is, for example, 11 μm or less. ４ Specifically, for example, is about 1064 nm.

[0189] The second recording medium may be in the form of a film. The second recording medium may be transmissive to visible light and near-infrared light in its initial state before recording. The second recording medium may become absorbent in the visible light range upon irradiation with laser light, or may be absorbent in the visible light range from the beginning even without irradiation with laser light. The second recording medium is preferably a laser marking layer. The laser marking layer may be a known laser marking sheet. Many known laser marking sheets become absorbent in the visible light range upon irradiation with laser light, or are initially absorbent in the visible light range even without irradiation with laser light. The laser marking layer is configured to be laser markable by, for example, at least one of the following methods (1) to (5). However, the laser marking layer may also be configured to be laser markable by a method other than the following methods (1) to (5). (1) A method of foaming a resin material to develop color. (2) A method of adding an additive that absorbs laser light to a resin material, causing the additive itself to develop color. (3) A method of adding an additive that absorbs laser light to a resin material, causing the additive to heat up and carbonize the surrounding resin material, resulting in color development. (4) A method of etching the surface of a resin layer by irradiating it with a laser, utilizing changes in the surface condition. (5) A method of marking by irradiating a black or dark colored resin material with laser light, causing the colorant (carbon black) to sublimate (decompose) and decolorize (exposing the base color of the resin material).

[0190] Specifically, the laser marking layer includes, for example, a light-to-heat conversion agent and a resin material. The light-to-heat conversion agent includes, for example, carbon. The resin material includes, for example, a polycarbonate resin.

[0191] Peak wavelength λ １ , peak wavelength λ ２ , peak wavelength λ ３ and peak wavelength λ ４ is λ ３ <λ ２ <λ １ <λ ４ It is preferable that the following relationship be satisfied: This allows the first recording medium and the second recording medium to be imaged independently.

[0192] [Modification 19] In the first embodiment, an example has been described in which the laminate is used as a page 20A of a passport 20 (see FIGS. 1 and 2). However, the laminate is not limited to this example, and may be used as a card 30 as shown in FIG. 18. In this case, the thickness and hardness of the laminate are adjusted depending on the use of the card 30.

[0193] The card 30 is an example of a security document, and may be a security card, a financial payment card (e.g., a credit card, a cash card, etc.), an ID card (e.g., an employee ID card, a membership card, a student ID card, a driver's license, an identity card, etc.), or a personal transaction card (e.g., a prepaid card, a point card, etc.).

[0194] The laminate may be used as a housing for an electronic device or the like, in addition to the passport 20 or the card 30. In this case, the thickness and hardness of the laminate are adjusted depending on the application of the housing.

[0195] The configuration of the second embodiment may be applied to the card 30. Furthermore, the configurations of the first to eighteenth modifications may be applied to the card 30.

[0196] [Modification 20] The configurations of Modification 1 to Modification 19 may be applied to the passport 20 according to the second embodiment.

[0197] (Other Modifications) The first embodiment, the second embodiment, and modifications 1 to 20 of the present disclosure (hereinafter referred to as "first embodiment, etc.") have been specifically described above, but the present disclosure is not limited to the above-described first embodiment, etc., and various modifications based on the technical ideas of the present disclosure are possible.

[0198] For example, the configurations, methods, processes, shapes, materials, and numerical values, etc., described in the first embodiment and the like are merely examples, and different configurations, methods, processes, shapes, materials, and numerical values, etc., may be used as necessary.

[0199] The configurations, methods, steps, shapes, materials, numerical values, etc. of the first embodiment and the like described above can be combined with one another without departing from the spirit of the present disclosure.

[0200] In the numerical ranges described in stages in the first embodiment and the like, the upper or lower limit of a numerical range of a certain stage may be replaced with the upper or lower limit of a numerical range of another stage.

[0201] Unless otherwise specified, the materials exemplified in the first embodiment and the like can be used singly or in combination of two or more.

[0202] The present disclosure can also employ the following configurations. (1) A laminate comprising three or more recording layers each capable of changing its color state to a different color by near-infrared laser light, and a diffuse reflective layer provided below the three or more recording layers, wherein the total light reflectance for near-infrared light having a wavelength of 1080 nm incident on the diffuse reflective layer from the side of the three or more recording layers is 93.0% or more. (2) The laminate according to (1), wherein the distance between the diffuse reflective layer and the recording layer closest to the diffuse reflective layer among the three or more recording layers is less than 150 μm. (3) The laminate according to (1), wherein the diffuse reflective layer and the recording layer closest to the diffuse reflective layer among the three or more recording layers are adjacent to each other. (4) The laminate according to (1), further comprising a first intermediate layer, a second intermediate layer, a third intermediate layer, a UV-cut layer, an adhesive layer, and a cover layer, wherein the three or more recording layers include a first recording layer, a second recording layer, and a third recording layer, and the first recording layer, the first intermediate layer, the second recording layer, the second intermediate layer, the third recording layer, the third intermediate layer, the UV-cut layer, the adhesive layer, and the cover layer are laminated in this order on the diffuse reflective layer. (5) The laminate according to any one of (1) to (3), further comprising a light-transmitting layer capable of transmitting visible light and near-infrared light between the three or more recording layers and the diffuse reflective layer. (6) The laminate according to (5), wherein the light-transmitting layer contains a polycarbonate-based resin. (7) The laminate according to any one of (1) to (6), wherein the diffuse reflective layer is capable of diffusively reflecting visible light and near-infrared light. (8) The laminate according to any one of (1) to (6), wherein the diffuse reflective layer contains particles capable of diffusing and reflecting visible light and near-infrared light. (9) The laminate according to (8), wherein the particles contain a white pigment. (10) The laminate according to any one of (1) to (9), wherein the diffuse reflective layer contains a polycarbonate-based resin. (11) The laminate according to any one of (1) to (10), wherein the change in the colored state of the three or more recording layers is an irreversible change.(12) The laminate according to any one of (1) to (11), wherein each of the three or more recording layers contains a color former having electron donating properties, a developer having electron accepting properties, and a matrix resin. (13) The laminate according to any one of (1) to (12), wherein the peak wavelength of the near-infrared laser light is 750 nm or more and 950 nm or less. (14) The laminate according to any one of (1) to (4), further comprising: an encasing layer provided on the diffuse reflective layer and encasing the three or more recording layers; and a protective layer provided on the encasing layer, wherein the diffuse reflective layer and the encasing layer are bonded together by fusion or an adhesive, and the encasing layer and the protective layer are bonded together by fusion or an adhesive. (15) The laminate according to (5) or (6), further comprising: an encasing layer provided on the light-transmitting layer and encasing the three or more recording layers; and a protective layer provided on the encasing layer, wherein the light-transmitting layer and the encasing layer are bonded together by fusion or an adhesive, and the encasing layer and the protective layer are bonded together by fusion or an adhesive. (16) A laminate comprising: three or more recording layers each capable of changing its color state to a different color when exposed to near-infrared laser light; and a diffuse reflective layer provided below the three or more recording layers, wherein the distance between the diffuse reflective layer and the recording layer closest to the diffuse reflective layer among the three or more recording layers is less than 150 μm. (17) A booklet comprising the laminate according to any one of (1) to (16). (18) A card comprising the laminate according to any one of (1) to (16). (19) A security document comprising the laminate according to any one of (1) to (16).(20) A recording medium for a security document that can be written using near-infrared laser light diffusely reflected by a diffuse reflection layer, the recording medium comprising a first recording layer, a first intermediate layer, a second recording layer, a second intermediate layer, a third recording layer, a third intermediate layer, a UV cut layer, an adhesive layer, and a cover layer in that order, the first recording layer, the second recording layer, and the third recording layer are configured so that their colored states can be changed to different colors by near-infrared laser light, and the recording medium is placed on a diffuse reflection layer that has a total light reflectance of 99.0% or more for near-infrared light with a wavelength of 1080 nm, and the total light reflectance measured by irradiating near-infrared light with a wavelength of 1080 nm onto the diffuse reflection layer through the recording medium is 93.0% or more.

[0203] (21) A laminate comprising: a recording medium including three or more recording layers, each of which is configured to be able to change its color state to a different color by near-infrared laser light; and a diffuse reflective layer provided below the recording medium, wherein the laminate has a total light reflectance of 93.0% or more for near-infrared light of a wavelength of 1080 nm incident on the diffuse reflective layer from the recording medium side. (22) A laminate comprising: a recording medium including three or more recording layers, each of which is configured to be able to change its color state to a different color by near-infrared laser light; and a diffuse reflective layer provided below the recording medium, wherein the distance between the diffuse reflective layer and the recording layer of the three or more recording layers that is closest to the diffuse reflective layer is less than 150 μm. (23) A recording medium with a release layer, comprising: a recording medium that is transmissive to near-infrared laser light; and a release layer provided on one or both sides of the recording medium, wherein the recording medium includes three or more recording layers that are each able to change their color state to a different color by near-infrared laser light. (24) The recording medium with a peelable layer according to (23), wherein the recording medium is for a security document. (25) The recording medium with a peelable layer according to (23) or (24), wherein each of the three or more recording layers contains a color former having electron donating properties, a color developer having electron accepting properties, and a matrix resin. (26) The recording medium with a peelable layer according to any one of (23) to (25), wherein one of the three or more recording layers is the bottommost layer of the recording medium. (27) The recording medium with a peelable layer according to (23) or (24), wherein each of the three or more recording layers contains a color former having electron donating properties, a color developer having electron accepting properties, and a matrix resin, wherein one of the three or more recording layers is the bottommost layer of the recording medium, and the matrix resin contained in the bottommost recording layer of the recording medium contains a polycarbonate-based resin.(28) The recording medium with a release layer according to any one of (23) to (27), wherein the recording medium further includes a first intermediate layer, a second intermediate layer, a third intermediate layer, a UV protection layer, an adhesive layer, and a cover layer, and the three or more recording layers include the first recording layer, the second recording layer, and the third recording layer, and the first recording layer, the first intermediate layer, the second recording layer, the second intermediate layer, the third recording layer, the third intermediate layer, the UV protection layer, the adhesive layer, and the cover layer are laminated in this order on the diffuse reflective layer. (29) A method for producing a laminate, comprising: producing a recording medium; and producing a laminate including the recording medium and a diffuse reflective layer, wherein the recording medium includes three or more recording layers whose coloring states can be changed to different colors by near-infrared laser light, and the total light reflectance for near-infrared light having a wavelength of 1080 nm incident on the diffuse reflective layer from the recording medium side is 93.0% or more. (30) A method for manufacturing a laminate, comprising: preparing a recording medium; and preparing a laminate including the recording medium and a diffuse reflective layer, wherein the recording medium includes three or more recording layers each capable of changing its color state to a different color by near-infrared laser light, and the distance between the diffuse reflective layer and a recording layer of the three or more recording layers that is closest to the diffuse reflective layer is less than 150 μm. (31) The method for manufacturing a laminate according to (29) or (30), further comprising, after preparing the recording medium and before preparing the laminate, peeling off a release layer from one or both sides of the recording medium. (32) The method for manufacturing a laminate according to any one of (29) to (31), wherein preparing the laminate includes fusing the recording medium and the diffuse reflective layer.

[0204] <4. Examples> Hereinafter, the present disclosure will be specifically described with reference to examples, but the present disclosure is not limited to these examples.

[0205] In the following examples and comparative examples, the distance D between the first recording layer, which is the closest of the three recording layers to the diffuse reflective substrate (diffuse reflective layer), and the diffuse reflective substrate (diffuse reflective layer) is a value determined by the measurement method described above in the first embodiment. Also, the total light reflectance of the diffuse reflective substrate (diffuse reflective layer) for near-infrared light with a wavelength of 1080 nm is a value determined by the measurement method described above in the first embodiment.

[0206] In the following examples and comparative examples, a film-like recording medium using a leuco dye as the color former in the first, second and third recording layers is referred to as a leuco film.

[0207] In the following examples and comparative examples, the term "transparent" means transparent to light in the visible and near-infrared ranges, unless otherwise specified.

[0208] Example 1 A diffuse reflective substrate, a recording medium, and a protective layer were stacked in this order, and the layers were bonded together by heat fusion to obtain a laminate.

[0209] The following materials were used as the diffuse reflective substrate (diffuse reflective layer) and protective layer: Protective layer: 50 μm thick, transparent polycarbonate film (hereinafter referred to as "PC film") Diffuse reflective substrate: 600 μm thick, white PC film with a total light reflectance of 99.9% for near-infrared light with a wavelength of 1080 nm.

[0210]

[0049] A leuco film having the following laminated structure was used as the recording medium: Cover layer: transparent PC film, thickness 25 μm Fourth adhesive layer: OCA, thickness 15 μm UV cut layer: thickness 10 μm Third resin layer: ultraviolet curable resin layer, thickness 3 μm Third adhesive layer: OCA, thickness 6 μm Third recording layer: recording layer that exhibits yellow color in a color-developed state, thickness 5 μm Second resin layer: resin layer containing ultraviolet curable resin and polycarbonate, thickness 3 μm Second adhesive layer: OCA, thickness 15 μm Second recording layer: recording layer that exhibits cyan color in a color-developed state, thickness 5 μm First resin layer: resin layer containing ultraviolet curable resin and polycarbonate, thickness 3 μm First adhesive layer: OCA, thickness 15 μm First recording layer: recording layer that exhibits magenta color in a color-developed state, thickness 5 μm In Example 1, the distance between the diffuse reflection layer and the first recording layer was set to 0 μm. In order to improve the total light reflectance of the drawn and undrawn areas, the layers provided above the diffuse reflective layer were made of materials that had high transmittance for near-infrared light with a wavelength of 1080 nm and that did not whiten during heat fusion.

[0211] The recording medium (leuco film) having the above layer structure was prepared as follows.

[0212] (Process for forming first recording layer) First, polycarbonate (PC) was dissolved as a matrix resin in a ketone solvent, and a color developer was added and dispersed using a rocking mill. The color developer was the compound of formula (1) above. Next, a leuco dye that exhibits a magenta color in the color-developed state was added, and the final ratio (mass ratio) of leuco dye:color developer:polycarbonate was adjusted to 1:2:4. Furthermore, at a wavelength λ １ A light-to-heat conversion agent having an absorption wavelength peak at 1000 nm and having a phthalocyanine skeleton was added to the mixture to prepare a coating material for forming a first recording layer.

[0213] Next, the paint for forming the first recording layer was applied to the flat surface by gravure coating, and dried and cured to form the first recording layer.

[0214] (Step of Forming First Laminated Film) First, a leuco dye that exhibits a cyan color in a color-developed state is used as a leuco dye, and a leuco dye that exhibits a cyan color in a color-developed state is used as a photothermal conversion agent. ２ A second recording layer-forming paint was prepared in the same manner as the first recording layer-forming paint, except that a photothermal conversion agent having an absorption wavelength peak at 1000 nm and a phthalocyanine skeleton was used. Next, a first resin layer-forming paint was prepared by mixing polycarbonate and an ultraviolet-curable acrylic resin. The polycarbonate used had a methacryloyl group. The first resin layer-forming paint was then applied to a flat surface, and the first resin layer-forming paint was then irradiated with ultraviolet light to harden, thereby forming a first resin layer. Next, a second recording layer-forming paint was applied to the first resin layer by gravure coating, and dried and hardened to form a second recording layer. This resulted in a first laminate film comprising a first resin layer and a second recording layer.

[0215] (Step of forming second laminated film) A leuco dye that exhibits yellow color in a color-developed state is used as the leuco dye, and a leuco dye that exhibits yellow color in a color-developed state is used as the light-to-heat conversion agent. ３ A photothermal conversion agent having an absorption wavelength peak at wavelength λ and having a phthalocyanine skeleton was used. Except for these, the process for forming the first laminate film was performed in the same manner as in the first laminate film formation process to obtain a second laminate film including a second resin layer and a third recording layer. １ , λ ２ , λ ３ were chosen to be different values.

[0216] (Step of Forming Third Laminated Film) A cover layer (PC film), a fourth adhesive layer (OCA), a UV-cut layer, and a third resin layer were laminated in this order to obtain a third laminated film.

[0217] (Lamination step) The third laminate film, the third adhesive layer (OCA), the second laminate film, the second adhesive layer (OCA), the first laminate film, the first adhesive layer (OCA), and the first recording layer were laminated in this order, thereby obtaining the desired recording medium.

[0218] [Example 2] A diffuse reflective substrate, a light-transmitting layer, a recording medium, and a protective layer were stacked in this order, and the layers were bonded together by heat fusion to obtain a laminate. The diffuse reflective substrate, the recording medium, and the protective layer were the same as those used in Example 1. A single transparent PC film with a thickness of 50 μm was used as the light-transmitting layer. In Example 2, the distance between the diffuse reflective substrate and the first recording layer was set to 50 μm.

[0219] [Example 3] A diffuse reflective substrate, a light-transmitting layer, a recording medium, and a protective layer were stacked in this order, and the layers were bonded together by heat fusion to obtain a laminate. The diffuse reflective substrate, the recording medium, and the protective layer were the same as those used in Example 1. A single transparent PC film with a thickness of 100 μm was used as the light-transmitting layer. In Example 3, the distance between the diffuse reflective substrate and the first recording layer was set to 100 μm.

[0220] [Comparative Example 1] A laminate was obtained in the same manner as in Example 2, except that a white PC film with a thickness of 400 μm was used as the diffuse reflective substrate and a transparent PC film with a thickness of 150 μm was used as the light transmitting layer. In Comparative Example 1, the distance between the diffuse reflective substrate and the first recording layer was set to 150 μm.

[0221] [Comparative Example 2] A laminate was obtained in the same manner as in Example 2, except that a white PC film with a thickness of 300 μm was used as the diffuse reflective substrate and a transparent PC film with a thickness of 250 μm was used as the light transmitting layer. In Comparative Example 2, the distance between the diffuse reflective substrate and the first recording layer was set to 250 μm.

[0222] [Comparative Example 3] A laminate was obtained in the same manner as in Example 2, except that a white PC film having a thickness of 100 μm was used as the diffuse reflective substrate and a transparent PC film having a thickness of 450 μm was used as the light transmitting layer. In Comparative Example 3, the distance between the diffuse reflective substrate and the first recording layer was set to 450 μm.

[0223] [Evaluation] The laminates of Examples 1 to 3 and Comparative Examples 1 to 3 obtained as described above were evaluated as follows.

[0224] (Total Light Reflectance of Undrawn Area) First, a measurement sample was prepared by cutting the laminate to a predetermined size. Next, the total light reflectance spectrum of the undrawn area of ​​the measurement sample was measured in the same manner as in the measurement of the total light reflectance of the undrawn area described in the first embodiment, and then the total light reflectance at a wavelength of 1080 nm was extracted from the spectrum. Figure 19 shows the measurement results of the total light reflectance spectrum of the undrawn area. Figure 20 shows a graph in which the horizontal axis represents the distance D between the diffuse reflective substrate and the first recording layer and the vertical axis represents the total light reflectance of the undrawn area at a wavelength of 1080 nm.

[0225] (Total Light Reflectance of Imaged Portion) First, the first recording layer, the second recording layer, and the third recording layer of the laminate were irradiated with the first near-infrared laser beam, the second near-infrared laser beam, and the third near-infrared laser beam, respectively, to image the recording medium (leuco film). At this time, the peak wavelengths of the first near-infrared laser beam, the second near-infrared laser beam, and the third near-infrared laser beam were each wavelength λ １ , wavelength λ ２ and wavelength λ ３ The laminate was then cut to a predetermined size to prepare a measurement sample. Next, the spectral spectrum of the total light reflectance of the drawn portion of the measurement sample was measured in the same manner as in the measurement of the total light reflectance of the undrawn portion described in the first embodiment, and the total light reflectance at a wavelength of 1080 nm was then extracted from the spectral spectrum. FIG. 21 shows the measurement results of the spectral spectrum of the total light reflectance of the drawn portion. FIG. 22 shows a graph in which the horizontal axis represents the distance D between the diffuse reflective substrate and the first recording layer and the vertical axis represents the total light reflectance of the drawn portion at a wavelength of 1080 nm.

[0226] (Maximum Drawing Speed) First, four laminates each of Examples 1 to 3 and Comparative Examples 1 to 3 were prepared, and each laminate was drawn at a drawing speed (sweep speed) of 1.5 m / s, 1.7 m / s, 1.9 m / s, and 2.1 m / s. Drawing was performed on each of the four laminates by irradiating the first recording layer, the second recording layer, and the third recording layer with a first near-infrared laser beam, a second near-infrared laser beam, and a third near-infrared laser beam, respectively. Next, measurement samples were prepared by cutting each laminate to a predetermined size. Next, the maximum color development OD (Optical Density) of the measurement samples was measured for each of the CMY colors using a spectrophotometer / densitometer (eXact, manufactured by X-Rite). Next, color development was evaluated according to the following criteria: A: All of the CMY maximum color development ODs were 1.0 or greater. B: At least one of the CMY maximum color development ODs was less than 1.00. For good full-color drawing (for example, good full-color drawing of a person), a maximum OD value of 1.0 or more is required for each of the CMY colors. For this reason, an OD value of 1.0 was used as the standard for determining whether a measurement sample is good or bad.

[0227] Next, the fastest drawing speed among the above drawing speeds at which the evaluation result "A" could be maintained was defined as the maximum drawing speed. Fig. 23A shows a graph in which the horizontal axis represents the distance D between the diffuse reflective substrate and the first recording layer, and the vertical axis represents the maximum drawing speed.

[0228] (Throughput) First, the drawing time [s] required to draw one passport photograph on the laminate was calculated. Next, the value obtained by dividing 3600 seconds by the drawing time [s] was used as the number of passports drawn per hour, i.e., the throughput [passports / h]. Fig. 23B shows a graph in which the horizontal axis represents the distance D between the diffuse reflective substrate and the first recording layer and the vertical axis represents the throughput.

[0229] Conventional printing machines for printing passports use a black-and-white laser engraving method. Such manufacturing equipment achieves a throughput of 120 copies / hour or more. Therefore, in this example, in order to achieve a throughput comparable to that of inkjet passport printing, the throughput of the laminates of Examples 1 to 3 and Comparative Examples 1 to 3, which utilize leuco printing, was evaluated using 120 copies / hour as the standard.

[0230]

[0231]

[0232] The above evaluation results reveal the following. The laminates of Examples 1 to 3, in which the total light reflectance of the unimaged and imaged portions is 93.0% or higher, can achieve a maximum image writing speed of 1.6 m / s or higher. Therefore, a throughput of 120 books / h or higher can be achieved. On the other hand, the laminates of Comparative Examples 1 to 3, in which the total light reflectance of the unimaged and imaged portions is less than 93.0%, cannot achieve a maximum image writing speed of 1.6 m / s or higher. Therefore, a throughput of 120 books / h or higher cannot be achieved. This is because a total light reflectance of 93.0% or higher can suppress light absorption in the light transmitting layer between the diffuse reflective substrate and the first recording layer, thereby improving the recording sensitivity of the recording medium, particularly the recording sensitivity of the first recording layer furthest from the light incident surface of the laminate.

[0233] In the laminates of Examples 1 to 3, in which the distance between the diffuse reflective substrate and the first recording layer is less than 150 μm, a maximum drawing speed of 1.6 m / s or more can be achieved. Therefore, a throughput of 120 books / h or more can be achieved. On the other hand, in the laminates of Comparative Examples 1 to 3, in which the distance between the reflective layer and the first recording layer is 150 μm or more, a maximum drawing speed of 1.6 m / s or more cannot be achieved. Therefore, a throughput of 120 books / h or more cannot be achieved. This is because when the distance between the diffuse reflective substrate and the first recording layer is less than 150 μm, the diffusely reflected light due to the light diffusion of the diffuse reflective substrate can be prevented from spreading beyond the drawing area of ​​the recording medium, thereby improving the recording sensitivity of the recording medium, particularly the recording sensitivity of the first recording layer furthest from the light incident surface of the laminate.

[0234] 10 Recording medium 11 Base material 12A, 12B, 12C, 12D Intermediate layer 12A １ , 12B １ , 12C １ , 12D １ Adhesive layer 12A ２ , 12B ２ , 12C ２, 12D ２ UV-curable resin layer 13A, 13B, 13C recording layer 14 cover layer 15 UV-cut layer 16 adhesive layer 17 peeling layer 20 passport (booklet) 20A page (laminate) 20P photograph 201 cover 202 back cover 21 diffuse reflection layer 22 light-transmitting layer 221 film 222 bonding layer 23, 24 protective layer 25 storage layer 25A storage section 26 frame 27, 28 bonding layer 30 card

Claims

1. A laminate comprising three or more recording layers each capable of changing its color state to a different color when exposed to near-infrared laser light, and a diffuse reflective layer provided below said three or more recording layers, wherein the total light reflectance for near-infrared light with a wavelength of 1080 nm incident on said diffuse reflective layer from the side of said three or more recording layers is 93.0% or more.

2. The laminate according to claim 1, wherein the distance between the diffuse reflective layer and the recording layer closest to the diffuse reflective layer among the three or more recording layers is less than 150 μm.

3. The laminate according to claim 1, wherein the diffuse reflective layer is adjacent to the recording layer that is closest to the diffuse reflective layer among the three or more recording layers.

4. The laminate according to claim 1, further comprising a first intermediate layer, a second intermediate layer, a third intermediate layer, a UV-cut layer, an adhesive layer, and a cover layer, wherein the three or more recording layers include a first recording layer, a second recording layer, and a third recording layer, and the first recording layer, the first intermediate layer, the second recording layer, the second intermediate layer, the third recording layer, the third intermediate layer, the UV-cut layer, the adhesive layer, and the cover layer are laminated in this order on the diffuse reflection layer.

5. The laminate according to claim 1, further comprising a light-transmitting layer capable of transmitting visible light and near-infrared light between the three or more recording layers and the diffuse reflection layer.

6. The laminate according to claim 5, wherein the light-transmitting layer contains a polycarbonate-based resin.

7. The laminate according to claim 1, wherein the diffuse reflective layer is capable of diffusively reflecting visible light and near-infrared light.

8. The laminate according to claim 1, wherein the diffuse reflective layer contains particles capable of diffusively reflecting visible light and near-infrared light.

9. The laminate according to claim 8, wherein the particles include a white pigment.

10. The laminate according to claim 1, wherein the diffuse reflective layer contains a polycarbonate-based resin.

11. The laminate according to claim 1, wherein the change in the colored state of the three or more recording layers is an irreversible change.

12. The laminate according to claim 1, wherein each of the three or more recording layers contains a color former having electron donating properties, a color developer having electron accepting properties, and a matrix resin.

13. The laminate according to claim 1, wherein the peak wavelength of the near-infrared laser light is 750 nm or more and 950 nm or less.

14. The laminate according to claim 1, further comprising: an accommodation layer provided on the diffuse reflection layer and accommodating the three or more recording layers; and a protective layer provided on the accommodation layer, wherein the diffuse reflection layer and the accommodation layer are bonded together by fusion or an adhesive, and the accommodation layer and the protective layer are bonded together by fusion or an adhesive.

15. The laminate according to claim 5, further comprising: an accommodation layer provided on the light-transmitting layer and accommodating the three or more recording layers; and a protective layer provided on the accommodation layer, wherein the light-transmitting layer and the accommodation layer are bonded together by fusion or an adhesive, and the accommodation layer and the protective layer are bonded together by fusion or an adhesive.

16. A laminate comprising: three or more recording layers each capable of changing its color state to a different color when exposed to near-infrared laser light; and a diffuse reflective layer provided below said three or more recording layers, wherein the distance between said diffuse reflective layer and the recording layer of said three or more recording layers that is closest to said diffuse reflective layer is less than 150 μm.

17. A booklet comprising the laminate of claim 1.

18. A card comprising the laminate of claim 1.

19. A security document comprising the laminate of claim 1.

20. A recording medium for security documents that can be written using near-infrared laser light diffusely reflected by a diffuse reflection layer, comprising, in order, a first recording layer, a first intermediate layer, a second recording layer, a second intermediate layer, a third recording layer, a third intermediate layer, a UV-cut layer, an adhesive layer, and a cover layer, wherein the first recording layer, the second recording layer, and the third recording layer are configured so that their coloring states can be changed to different colors by near-infrared laser light, and the recording medium is placed on a diffuse reflection layer that has a total light reflectance of 99.0% or more for near-infrared light with a wavelength of 1080 nm, and the total light reflectance measured by irradiating near-infrared light with a wavelength of 1080 nm onto the diffuse reflection layer through the recording medium is 93.0% or more.

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