Laminates, cards, passports, methods for manufacturing the same, and laser marking methods.

Abstract

A multilayer body which comprises at least two layers, namely a resin layer (A) and a resin layer (B), wherein: the resin layer (A) contains a resin (a) and a dye; the content of the dye in the resin layer (A) is less than 50 parts by mass relative to 100 parts by mass of the resin (a); the content of a color developer in the resin layer (A) is less than 0.5 part by mass relative to 100 parts by mass of the resin (a); the resin layer (B) contains a resin (b) and a color developer; the content of the color developer in the resin layer (B) is less than 50 parts by mass relative to 100 parts by mass of the resin (b); and the content of a dye in the resin layer (B) is less than 0.5 part by mass relative to 100 parts by mass of the resin (b).

Description

[Technical Field]

[0001] The present invention relates to laminates, cards, and passports, and more particularly to laminates usable for various markings such as laser marking, as well as to cards and passports having such laminates. [Background technology]

[0002] Credit cards, cash cards, ID cards, tag cards, and passports can be marked with letters, barcodes, symbols, and marks using laser irradiation. While laser marking is currently used in black and white, color laser marking using leuco dyes and other materials has been explored in recent years. In color laser marking, it is known that various types of information can be marked on resin compositions containing thermoplastic polymers, color-developing components such as leuco dyes, and color developers (see, for example, Patent Document 1), or on recording layers formed by coatings containing resin, leuco dyes, color developers, and photothermal converters (see, for example, Patent Document 2).

[0003] Furthermore, Patent Document 2 describes a recording medium in which multiple recording layers, each formed of paint and having different color tones for each layer, are alternately stacked with an insulating layer, and an attempt has been made to produce multiple colors by having different absorption wavelengths for the photothermal conversion agent in each recording layer. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-302236 [Patent Document 2] International Publication No. 2018 / 235451 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, as described in Patent Documents 1 and 2, when a dye such as a leuco dye and a developer in an amount sufficient to sufficiently develop the dye are included in the same resin layer, it can be difficult to mold the resin layer while maintaining a decolorized state. For example, resin layers containing dyes and developers used in cards and passports are being considered for melt-molding, but when a resin layer is formed by melt-molding, the heat generated during the mixing of the resin can cause the dye and developer to react and develop color.

[0006] Therefore, the object of the present invention is to provide a laminate that prevents color development when forming a resin layer containing a pigment, and that can appropriately develop color when marking by laser irradiation or the like. [Means for solving the problem]

[0007] As a result of diligent research, the inventors have found that the above problems can be solved by providing a resin layer (B) separate from the resin layer (A) containing a pigment, and by incorporating a color developer into the resin layer (B), and further by adjusting the pigment and color developer content of each resin layer (A) and (B), and have completed the present invention as follows. That is, the present invention provides the following [1] to

[36] .

[0008] [1] A laminate having at least two layers, a resin layer (A) and a resin layer (B), The resin layer (A) contains resin (a) and a dye, wherein the dye content in the resin layer (A) is less than 50 parts by mass per 100 parts by mass of resin (a), and the developer content in the resin layer (A) is less than 0.5 parts by mass per 100 parts by mass of resin (a). A laminate in which the resin layer (B) comprises a resin (b) and a color developer, wherein the content of the color developer in the resin layer (B) is less than 50 parts by mass per 100 parts by mass of resin (b), and the content of the dye in the resin layer (B) is less than 0.5 parts by mass per 100 parts by mass of resin (b). [2] The laminate according to [1] above, wherein the thickness of the resin layer (A) is greater than 6 μm. [3] The laminate according to [1] or [2] above, wherein the thickness of the resin layer (B) is more than 6 μm. [4] The laminate according to any one of [1] to [3] above, wherein the content of the pigment in the resin layer (A) is 30 parts by mass or less with respect to 100 parts by mass of the resin (a). [5] The laminate according to any one of [1] to [4] above, wherein the content of the developer in the resin layer (B) is 30 parts by mass or less with respect to 100 parts by mass of the resin (b). [6] The laminate according to any one of [1] to [5] above, wherein the thermal decomposition temperature of the pigment is 200 °C or higher. [7] The laminate according to any one of [1] to [6] above, wherein the thermal decomposition temperature of the developer is 200 °C or higher. [8] The laminate according to any one of [1] to [7] above, wherein the crystal melting temperature of the pigment is 100 °C or higher. [9] The laminate according to any one of [1] to [8] above, wherein the crystal melting temperature of the pigment is 300 °C or lower.

[10] The laminate according to any one of [1] to [9] above, wherein the crystal melting temperature of the developer is 100 °C or higher.

[11] The laminate according to any one of [1] to

[10] above, wherein the crystal melting temperature of the developer is 300 °C or lower.

[12] The laminate according to any one of [1] to

[11] above, wherein both the resin (a) and the resin (b) are thermoplastic resins.

[13] The laminate according to any one of [1] to

[12] above, wherein the resin (a) is at least one selected from the group consisting of a polycarbonate resin, a polyester resin, a polyolefin resin, and an acrylic resin.

[14] The laminate according to any one of [1] to

[13] above, wherein the resin (b) is at least one selected from the group consisting of a polycarbonate resin, a polyester resin, a polyolefin resin, and an acrylic resin.

[15] When the content of the dye with respect to 100 parts by mass of the resin (a) in the resin layer (A) is defined as content (A1), and the content of the dye with respect to 100 parts by mass of the resin (b) in the resin layer (B) is defined as content (B1), the laminate according to any one of [1] to

[14] above, wherein the ratio (B1 / A1) of content (B1) to content (A1) is 0 or more and 0.5 or less.

[16] When the content of the developer with respect to 100 parts by mass of the resin (a) in the resin layer (A) is defined as content (A2), and the content of the developer with respect to 100 parts by mass of the resin (b) in the resin layer (B) is defined as content (B2), the laminate according to any one of [1] to

[15] above, wherein the ratio (A2 / B2) of content (A2) to content (B2) is 0 or more and 0.5 or less.

[17] When the content of the dye with respect to 100 parts by mass of the resin (a) in the resin layer (A) is defined as content (A1), and the content of the developer with respect to 100 parts by mass of the resin (b) in the resin layer (B) is defined as content (B2), the laminate according to any one of [1] to

[16] above, wherein the ratio (A1 / B2) of content (A1) to content (B2) is 0.01 or more and 3 or less.

[18] The laminate according to any one of [1] to

[17] above, wherein the resin layer (B) is directly laminated on at least one surface of the resin layer (A).

[19] The laminate according to any one of [1] to

[17] above, further comprising an intermediate resin layer (C) between the resin layer (A) and the resin layer (B).

[20] An area of 400 cm 2 or less, the laminate according to any one of [1] to

[19] above.

[21] An area of 200 cm 2 or less, the laminate according to any one of [1] to

[20] above.

[22] The laminate according to any one of [1] to

[21] above, which is capable of developing color by laser irradiation.

[23] The laminate according to any one of [1] to

[22] above, used for a card.

[24] The laminate according to any one of [1] to

[22] above, used for a passport.

[25] A card comprising the laminate according to any one of [1] to

[23] above.

[26] A passport comprising the laminate described in any of [1] to

[22] and

[24] above.

[27] A method for producing a laminate according to any one of [1] to

[24] above, comprising the step of melting and kneading at least the resin (a) and the dye.

[28] A method for producing a laminate according to any one of [1] to

[24] above, comprising the step of melting and kneading at least the resin (b) and the color developer.

[29] The method for manufacturing a laminate according to

[27] or

[28] , further comprising the step of laminating at least the resin layer (A) and the resin layer (B).

[30] The method for manufacturing a laminate according to

[29] above, wherein at least the step of laminating the resin layer (A) and the resin layer (B) is carried out by an extrusion method or a lamination method.

[31] A method for producing a laminate, comprising: melt-kneading at least a resin (a) and a dye to produce a resin composition (A); melt-kneading at least a resin (b) and a color developer to produce a resin composition (B); and laminating a resin layer (A) formed from at least a resin composition (A) and a resin layer (B) formed from at least a resin composition (B) by an extrusion or lamination method.

[32] A laser marking method for a laminate produced by the method for manufacturing a laminate described in

[31] above, wherein laser marking is performed by laser irradiation.

[33] A method for manufacturing a card comprising a laminate according to any of [1] to

[23] above, comprising at least the steps of laminating and fusing the laminate with another film, and laser marking by laser irradiation.

[34] A method for manufacturing a passport comprising a laminate as described in any of [1] to

[22] and

[24] above, A method for manufacturing a passport, comprising at least the steps of laminating and fusing the laminate with another film, and laser marking by laser irradiation.

[35] A method of laser marking a laminate described in any of [1] to

[24] above and using it for a card or passport.

[36] Use of the laminate described in any of [1] to

[24] above on a card or passport, wherein the laminate is laser-marked. [Effects of the Invention]

[0009] The present invention provides a laminate that prevents color development when molding a resin layer containing a pigment, while enabling appropriate color development when marking by laser irradiation or the like. [Modes for carrying out the invention]

[0010] The present invention will be described in detail below with reference to embodiments. However, the present invention is not limited to the embodiments described below.

[0011] <Laminate> The laminate of the present invention is a laminate having at least two layers, a resin layer (A) and a resin layer (B), wherein resin layer (A) contains a resin (a) and a dye, and resin layer (B) contains a resin (b) and a color developer. The laminate of the present invention, having the above configuration, allows for the appropriate color development of the laminate when marking by irradiating the laminate with a laser or the like to cause the color developer of the resin layer (B) to react with the dye of the resin layer (A). On the other hand, in this laminate, it is not necessary to include a sufficient amount of color developer in resin layer (A), nor is it necessary to include a sufficient amount of dye in resin layer (B). Therefore, during the molding of each resin layer (A) and (B), it is possible to prevent the dye and color developer from reacting and developing color in each resin layer, and to maintain a colorless state.

[0012] The resin (a) contained in the resin layer (A) may be a thermosetting resin or a thermoplastic resin, but it is preferably a thermoplastic resin. Similarly, the resin (b) contained in resin layer (B) may be a thermosetting resin or a thermoplastic resin, but it is preferable that it be a thermoplastic resin. Therefore, it is preferable that both resin (a) and resin (b) are thermoplastic resins. By using thermoplastic resins for resin (a) and resin (b), the resin layers (A) and (B) can be molded by melt deposition or the like, and the laminate can also be manufactured by co-extrusion or press molding, thereby improving moldability and productivity. Furthermore, by using thermoplastic resins, when the laminate is heated by laser irradiation or the like, the dye and / or developer migrate, making it easier for the developer of resin layer (B) to react with the dye of resin layer (A), thus improving color development. Furthermore, by using thermoplastic resin, the resin layers (A) and (B) do not need to be formed by paint coating, thus preventing the resin layers (A) and (B) from being scraped or peeled off during processing or actual product use. Therefore, it has good shelf life and is suitable for passport and card applications from a security (reliability) standpoint.

[0013] [Thermoplastic resin] The thermoplastic resins preferably used for resin (a) and resin (b) are not particularly limited, but examples include polycarbonate resin, polyester resin, polyolefin resin, acrylic resin, polystyrene resin, polyamide resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl alcohol resin, ethylene-vinyl alcohol resin, polycycloolefin resin, ethylene vinyl acetate copolymer resin, ethylene (meth)acrylate copolymer resin, polyphenylene ether resin, polyacetal resin, acrylonitrile-butadiene-styrene copolymer resin, polyaryl ether ketone resin, polyimide resin, polyphenylene sulfide resin, polyarylate resin, polysulfone resin, polyethersulfone resin, and fluororesins. Among these, it is preferable to use polycarbonate resin, polyester resin, polyolefin resin, and acrylic resin as resin (a). Using these resins makes it easier to obtain a laminate with high transparency. Among these, it is more preferable to use either polycarbonate resin or polyester resin as resin (a), and polycarbonate resin is particularly preferred. Furthermore, from a similar viewpoint, it is preferable to use any of polycarbonate resin, polyester resin, polyolefin resin, and acrylic resin as resin (b), and more preferably polycarbonate resin and polyester resin, with polycarbonate resin being particularly preferred. By using at least one of polycarbonate resin and polyester resin, particularly polycarbonate resin, for resin (a) and resin (b), it becomes easier to ensure a certain level of mechanical strength, making it suitable for use in cards or passports. Furthermore, it becomes easier to prevent discoloration of resin layer (A) during the manufacturing of the laminate. The thermoplastic resins described above may be used individually in each of resins (a) and (b), or two or more may be used in combination.

[0014] In resin (a) and resin (b), it is preferable that polycarbonate resin, polyester resin, polyolefin resin, or acrylic resin be the main component. Specifically, resin layer (A) contains, based on the total amount of resin (a) contained in resin layer (A), preferably 50% to 100% by mass, more preferably 70% to 100% by mass, and even more preferably 90% to 100% by mass of one of the polycarbonate resin, polyester resin, polyolefin resin, or acrylic resin. Similarly, the resin layer (B) contains, based on the total amount of resin (b) contained in the resin layer (B), preferably 50% to 100% by mass, more preferably 70% to 100% by mass, and even more preferably 90% to 100% by mass of any of the following: polycarbonate resin, polyester resin, polyolefin resin, or acrylic resin.

[0015] (Polycarbonate resin) The polycarbonate resin used in one or both of resins (a) and (b) is not particularly limited, but bisphenol polycarbonate can be suitably used. Bisphenol polycarbonate refers to a material in which 50 mol% or more, preferably 70 mol% or more, and more preferably 90 mol% or more of the structural units derived from diols are bisphenol. The bisphenol polycarbonate may be either a homopolymer or a copolymer. Furthermore, the bisphenol polycarbonate may have a branched structure, a linear structure, or a mixture of a resin having a branched structure and a resin having only a linear structure.

[0016] The method for producing the bisphenol-based polycarbonate used in the present invention may be any known method, such as the phosgene method, the transesterification method, or the pyridine method. As an example, a method for producing polycarbonate resin by the transesterification method will be described below. The transesterification process is a manufacturing method that involves molten transesterification polymerization of bisphenol and diester carbonate using a basic catalyst, and further adding an acidic substance to neutralize the basic catalyst.

[0017] A typical example of bisphenol is 2,2-bis(4-hydroxyphenyl)propane, i.e., bisphenol A, which is preferably used, but some or all of bisphenol A may be replaced with other bisphenols.

[0018] Specific examples of bisphenols include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 1,1-bis(4-hydroxyphenyl)-1-phenylethane (bisphenol AP), 2,2-bis(4-hydroxyphenyl)hexafluoropropane (bisphenol AF), 2,2-bis(4-hydroxyphenyl)butane (bisphenol B), bis(4-hydroxyphenyl)diphenylmethane (bisphenol BP), 2,2-bis(3-methyl-4-hydroxyphenyl)propane (bisphenol C), 1,1-bis(4-hydroxyphenyl)ethane (bisphenol E), bis(4-hydroxyphenyl)methane (bisphenol F), 2,2-bis( Examples include 4-hydroxy-3-isopropylphenyl)propane (bisphenol G), 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene (bisphenol M), bis(4-hydroxyphenyl)sulfone (bisphenol S), 1,4-bis(2-(4-hydroxyphenyl)-2-propyl)benzene (bisphenol P), 5,5'-(1-methylethylidene)-bis[1,1'-(bisphenyl)-2-ol]propane (bisphenol PH), 1,1-bis(4-hydroxyphenyl)3,3,5-trimethylcyclohexane (bisphenol TMC), and 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z).

[0019] On the other hand, typical examples of diester carbonates include diphenyl carbonate, ditrile carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis(biphenyl) carbonate, diethyl carbonate, dimethyl carbonate, dibutyl carbonate, and dicyclohexyl carbonate. Of these, diphenyl carbonate is particularly preferred.

[0020] The mass-average molecular weight of the bisphenol-based polycarbonate used in this invention is typically in the range of 10,000 to 100,000, preferably 30,000 to 80,000, taking into account the balance between mechanical properties and moldability. The mass-average molecular weight can be measured using gel permeation chromatography (GPC) with polystyrene as the standard substance. Furthermore, the viscosity-average molecular weight of bisphenol-based polycarbonates is typically in the range of 12,000 to 40,000, preferably 15,000 to 35,000, more preferably 20,000 to 30,000, and even more preferably 22,000 to 28,000, considering the balance between mechanical properties and moldability. The viscosity-average molecular weight is measured using dichloromethane as the solvent and an Ubbelohde viscometer to determine the intrinsic viscosity ([η]) (unit dl / g) at a temperature of 20°C, using Schnell's viscosity formula: η = 1.23 × 10⁻⁶ -4 M 0.83 It can be calculated from the formula.

[0021] The polycarbonate resin used in one or both of resins (a) and (b) is preferably a polycarbonate resin that contains structural units derived from a dihydroxy compound having a part of its structure represented by the following formula (1). By using such a polycarbonate resin, it is possible to mark clear characters, images, etc. by laser irradiation, and a laminate for laser marking can be provided that has excellent surface hardness, heat resistance, and weather resistance, and uses a plant-derived resin material.

[0022] [ka] However, this excludes cases where the part represented by formula (1) is part of -CH2-OH. That is, the dihydroxy compound refers to one that contains two hydroxyl groups and at least the part represented by formula (1).

[0023] Dihydroxy compounds having a part of their structure represented by formula (1) are not particularly limited as long as they have the structure represented by formula (1) in their molecule, but specifically, examples include dihydroxy compounds represented by the following formula (2) and dihydroxy compounds having a cyclic ether structure, such as the spiroglycol represented by the following formula (3).

[0024] [ka] [ka] In formula (3), R1 to R4 are each independently alkyl groups having 1 to 3 carbon atoms.

[0025] Other examples include compounds having aromatic groups in the side chains, such as 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene and 9,9-bis(4-(2-hydroxyethoxy)substituted phenyl)fluorene (where substituents in the substituted phenyl include linear or branched alkyl groups, cycloalkyl groups, and aryl groups such as phenyl groups, with approximately 1 to 6 carbon atoms), and having an ether group bonded to the aromatic group in the main chain. Among the above, dihydroxy compounds having a cyclic ether structure are preferred, and anhydrous sugar alcohols represented by formula (2) are particularly preferred. More specifically, dihydroxy compounds represented by formula (2) include isosorbide, isomannide, and isoidette, which are stereoisomers of each other. These can be used individually, or two or more can be used in combination.

[0026] When a polycarbonate resin contains structural units derived from a dihydroxy compound having a moiety represented by formula (1) as part of its structure, it may also contain structural units other than those derived from the dihydroxy compound. For example, it is preferable to contain structural units derived from at least one dihydroxy compound selected from aliphatic dihydroxy compounds and alicyclic dihydroxy compounds.

[0027] Examples of aliphatic dihydroxy compounds include those having approximately 2 to 12 carbon atoms, preferably at least one selected from ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. Furthermore, structural units derived from aliphatic dihydroxy compounds, such as those described in International Publication No. 2004 / 111106, can also be used.

[0028] The structural units derived from alicyclic dihydroxy compounds preferably include at least one of a five-membered ring structure or a six-membered ring structure, and in particular the six-membered ring structure may be fixed in a chair-like or boat-like shape by covalent bonds. By including structural units derived from alicyclic dihydroxy compounds of these structures, the heat resistance of the resulting polycarbonate resin can be improved. The number of carbon atoms in the alicyclic dihydroxy compound is, for example, 5 to 70, preferably 6 to 50, and more preferably 8 to 30. Preferably, the alicyclic dihydroxy compound is at least one selected from cyclohexanedimethanol, tricyclodecanedimethanol, adamantanediol, and pentacyclopentadecanedimethanol. From the viewpoint of economy and heat resistance, cyclohexanedimethanol or tricyclodecanedimethanol is more preferred, and cyclohexanedimethanol is even more preferred. Of the cyclohexanedimethanol compounds, 1,4-cyclohexanedimethanol is preferred because it is readily available industrially. Furthermore, structural units derived from alicyclic dihydroxy compounds, as described in International Publication No. 2007 / 148604, can also be used.

[0029] When a polycarbonate resin contains structural units derived from a dihydroxy compound having a moiety represented by formula (1) as part of its structure, it may also contain structural units derived from other dihydroxy compounds in addition to the aliphatic or alicyclic dihydroxy compounds mentioned above. For example, a small amount of 2,2-bis(4-hydroxyphenyl)propane (bisphenol-A) may be copolymerized.

[0030] When a polycarbonate resin contains structural units derived from a dihydroxy compound having a portion represented by formula (1) as part of its structure, the content of such structural units is preferably 20 mol% or more, more preferably 30 mol% or more, even more preferably 40 mol% or more, and even more preferably 50 mol% or more, and also preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less.

[0031] When polycarbonate resin contains structural units derived from a dihydroxy compound having a part of the structure represented by formula (1) above, it can be produced by either the phosgene method or the transesterification method in which it is reacted with a diester carbonate. Among these, the transesterification method is preferred, in which a dihydroxy compound having a part of the structure represented by formula (1) above and other dihydroxy compounds are reacted with a diester carbonate in the presence of a polymerization catalyst. As the diester carbonate, the compounds listed above can be used, with diphenyl carbonate being particularly preferred.

[0032] When a polycarbonate resin contains structural units derived from a dihydroxy compound having a portion represented by the above formula (1) as part of its structure, its molecular weight can be expressed in terms of reduced viscosity. From the viewpoint of imparting mechanical strength, the reduced viscosity is, for example, 0.3 dL / g or more, preferably 0.35 dL / g or more, and from the viewpoint of increasing fluidity during molding and improving productivity and moldability, it is, for example, 1.2 dL / g or less, preferably 1 dL / g or less, and more preferably 0.8 dL / g or less. The reduced viscosity is measured using a Ubbelohde viscometer at a temperature of 20.0°C ± 0.1°C, after precisely preparing the polycarbonate resin concentration to 0.6 g / dL using dichloromethane as the solvent.

[0033] In resin (a) and resin (b), or both, one type of polycarbonate resin may be selected from the above-mentioned types, or two or more types may be used in combination. Furthermore, when polycarbonate resin is used in resin (a) and resin (b), the polycarbonate resins used in resin (a) and resin (b) may be the same or different.

[0034] The glass transition temperature of polycarbonate resin is, for example, 70°C or higher, preferably 80°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher, and also, for example, 200°C or lower, preferably 180°C or lower, more preferably 170°C or lower, and even more preferably 165°C or lower. Polycarbonate resin usually has a single glass transition temperature. By setting the glass transition temperature to or below the above upper limit, it becomes easier to laminate resin layer (A) and resin layer (B) at a relatively low temperature without causing the dye to develop color. Furthermore, by setting it to or above the above lower limit, heat resistance can be ensured, making it suitable for use in passports and cards. When polycarbonate resin is used in a resin layer (A), its glass transition temperature is preferably lower than the crystalline melting temperature of the dye contained in the resin layer (A), and more preferably 5°C or more lower than the crystalline melting temperature of the dye. By setting the glass transition temperature lower than the crystalline melting temperature of the dye, the resin layer (A) can be laminated onto resin layer (B) or the like without melting the dye, making it easier to prevent discoloration during lamination. Furthermore, when polycarbonate resin is used in resin layer (B), the glass transition temperature is preferably lower than the crystal melting temperature of the color developer contained in resin layer (B), and more preferably 5°C or more lower than the crystal melting temperature of the color developer. By lowering the glass transition temperature below the crystal melting temperature of the color developer, the resin layer (B) can be laminated onto resin layer (A) or the like without melting the color developer, making it easier to prevent color development during lamination. The glass transition temperature can be adjusted by appropriately selecting the ratio of each structural unit that makes up the polycarbonate resin. The glass transition temperature of polycarbonate resin can be obtained by measuring the temperature dispersion of dynamic viscoelasticity using a viscoelastic spectrometer. For example, using a viscoelastic spectrometer "DVA-200" (manufactured by IT Measurement Control Co., Ltd.), and referring to JIS K7244-4:1999, a temperature dispersion measurement of dynamic viscoelasticity is performed at a strain of 0.07%, a frequency of 1 Hz, and a heating rate of 3 °C / min, and the temperature at which the peak of the main dispersion of the loss tangent (tanδ) is shown can be taken as the glass transition temperature.

[0035] Commercially available polycarbonate resins can be used. Specifically, bisphenol-based polycarbonates such as the "Yupilon" series and "Novarex" series from Mitsubishi Engineering Plastics, and the "Caliber" series from Sumika Polycarbonate, can be used. In addition, polycarbonate resins containing structural units derived from dihydroxy compounds having the part represented by formula (1), such as the "DURABIO" series from Mitsubishi Chemical Corporation, can be used.

[0036] (Polyester resin) The polyester resin may be a homopolyester or a copolymerized polyester. For homopolyesters, aromatic polyesters obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol are preferred. Examples of aromatic dicarboxylic acids include terephthalic acid and 2,6-naphthalenedicarboxylic acid, while examples of aliphatic glycols include ethylene glycol, diethylene glycol, butanediol, and 1,4-cyclohexanedimethanol. Typical aromatic dicarboxylic acids include terephthalic acid, while typical aliphatic glycols include ethylene glycol and butanediol. Examples of typical homopolyesters include polyethylene terephthalate (PET) and polybutylene terephthalate (PBT).

[0037] On the other hand, examples of dicarboxylic acid components of copolymerized polyesters include one or more types such as isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid, and examples of glycol components include one or more types such as ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol (1,4-CHDM), and neopentyl glycol.

[0038] The polyester may be crystalline or amorphous, but amorphous polyester is preferred. Using amorphous polyester is preferable because it tends to have good adhesion to other resin layers (resin layer (A) or (B)) and the intermediate resin layer (C) described later, and also tends to have good transparency. Furthermore, when used as a card or passport, it also has good adhesion to other components that make up the card or passport, such as the core sheet and protective layer described later. Amorphous polyester can be any polyester that is substantially amorphous. Examples of substantially amorphous polyesters (including those with low crystallinity) include polyesters that do not show a clear crystallization peak when heated using differential scanning calorimeter (DSC), polyesters that have crystalline properties but have a slow crystallization rate and do not become highly crystalline when molded by extrusion or other methods, and crystalline materials in which the heat of fusion (ΔHm) observed when heated using differential scanning calorimeter (DSC) is low, at 10 J / g or less. In other words, amorphous polyester in this invention also includes "crystalline polyester that is in an amorphous state."

[0039] As amorphous polyesters, copolymer polyesters in which terephthalic acid is the main dicarboxylic acid component, and 20 mol% to 80 mol% of 1,4-CHDM and 20 mol% to 80 mol% of ethylene glycol are the main glycol components are preferred because they easily achieve both sufficient heat resistance and low-temperature processability for practical use, and because the raw materials are readily available. Such copolymer polyesters are known as PETG resin (glycol-modified polyethylene terephthalate). Here, the "main component" of the dicarboxylic acid component means that, based on the total amount of the dicarboxylic acid component (100 mol%), it contains terephthalic acid in an amount of 70 mol% or more, preferably 80 mol% or more, and more preferably 98 mol% or more. Furthermore, the "main component" of the diol component means that, based on the total amount of the diol component (100 mol%), it contains a total amount of 1,4-CHDM and ethylene glycol in an amount of 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more. When the amount of 1,4-CHDM in the diol component is above the lower limit, the characteristics of a crystalline resin are suppressed, making it easier to suppress the decrease in transparency associated with crystallization and to achieve good adhesion with other layers. Similarly, when the amount of 1,4-CHDM is below the upper limit, the characteristics of a crystalline resin are suppressed, making it easier to suppress the decrease in transparency associated with crystallization and to achieve good adhesion with other layers, which is preferable.

[0040] Among copolymer polyesters within the aforementioned composition range, it is known that compositions in which 1,4-CHDM constitutes approximately 30 mol% of the diol component exhibit completely amorphous properties, with no crystallization behavior observed even in DSC (differential scanning calorimetry) measurements. Examples of completely amorphous polyesters include PETG resins such as "Easter GN001" manufactured by Eastman Chemical Corporation. However, this is not limited to the above. Copolymerized polyester resins having a structure in which crystallization is inhibited by the introduction of various copolymerization components, such as PET resin copolymerized with diethylene glycol, PET resin copolymerized with isophthalic acid, or PBT resin with low crystallinity, can also be used as substantially amorphous polyesters. Furthermore, among these exemplified polyester resins, polyester resins in which some or all of the terephthalic acid is replaced with naphthalenedicarboxylic acid can also be used if they are amorphous.

[0041] In either or both of resin (a) and resin (b), one type of polyester resin may be selected from those described above, or two or more types may be used in combination. Furthermore, when polyester resin is used in both resin (a) and resin (b), the polyester resins used in resin (a) and resin (b) may be the same or different.

[0042] (Polyolefin resin) Examples of polyolefin resins include polymers or copolymers thereof of various chain-like olefins such as ethylene, propylene, isobutylene, butene, poly(4-methylpentene), and isoprene. Among these, polyethylene resin and polypropylene resin are preferred, with polyethylene resin being more preferred.

[0043] The polyethylene resin is not particularly limited, but can be high-density polyethylene (HDPE; density 0.942 g / cm³). 3 (The above) Medium-density polyethylene (MDPE; density 0.930 g / cm³) 3 More than 0.942g / cm 3 (less than), low-density polyethylene (LDPE; density 0.930 g / cm³) 3Any of the following may be used (less than), or linear low-density polyethylene (LLDPE), but linear low-density polyethylene is preferred. Therefore, it is preferable to use polyethylene resin for both resin (a) and resin (b), and more preferably to use linear low-density polyethylene for both resin (a) and resin (b).

[0044] Furthermore, the polypropylene resin may be homopolypropylene, or it may be a random copolymer (random polypropylene) or block copolymer (block polypropylene) of propylene with ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, or 1-decene, or other α-olefins.

[0045] In either or both of resin (a) and resin (b), one type of polyolefin resin may be selected from those described above, or two or more types may be used in combination. Furthermore, when polyolefin resins are used in resin (a) and resin (b), the polyolefin resins used in resin (a) and resin (b) may be the same or different.

[0046] (Acrylic resin) As the acrylic resin, acrylic polymers obtained by polymerizing or copolymerizing various (meth)acrylates can be used. It is preferable to use an acrylic copolymer obtained by polymerizing monomers in which alkyl (meth)acrylate is the main component (for example, 50 mol% or more of the total monomer, preferably 70-100 mol%). For example, alkyl (meth)acrylates with approximately 1 to 18 carbon atoms in the alkyl group are preferable. In either or both of resin (a) and resin (b), one type of acrylic resin may be selected from those described above, or two or more types may be used in combination. Furthermore, when acrylic resin is used in both resin (a) and resin (b), the acrylic resins used in resin (a) and resin (b) may be the same or different.

[0047] Furthermore, the thermoplastic resins used in resin (a) and resin (b) may be of the same type or different types, but it is preferable to use the same type. Therefore, for example, if resin (a) contains polycarbonate resin as its main component, it is preferable that resin (b) contains polycarbonate resin as its main component, and if resin (b) contains polyester resin as its main component, it is preferable that resin (b) also contains polyester resin as its main component. Similarly, if resin (a) contains acrylic resin as its main component, it is sufficient that resin (b) also contains acrylic resin as its main component, and if resin (b) contains polyolefin resin as its main component, it is sufficient that resin (b) also contains polyolefin resin as its main component. Since resin (a) and resin (b) contain the same type of thermoplastic resin as their main component, the manufacturing of the laminate becomes easier. Furthermore, when resin layer (A) and resin layer (B) are laminated directly, their adhesion is enhanced. Moreover, even when resin layer (A) and resin layer (B) are laminated via an intermediate resin layer (C), by appropriately selecting the resin of the intermediate resin layer (C), resin layer (A) and resin layer (B) can be laminated with high adhesive strength via the intermediate resin layer (C).

[0048] Furthermore, when one of resins (a) and (b) contains polyester resin as its main component, it is also preferable that the other of resins (a) and (b) contains polycarbonate resin as its main component. In this case, as described above, it is preferable to use amorphous polyester, particularly PETG resin, as the polyester resin, from the viewpoint of adhesion between resin layer (A) and resin layer (B) and suppression of the decrease in transparency due to crystallization. Furthermore, it is also preferable to use polyester resin and polycarbonate resin in combination as either one or both of resin (a) and resin (b).

[0049] <Pigments and color developers> The resin layer (A) of the present invention contains a resin (a) and a dye. The dye is a dye that can be colored by a color developer described later. Preferably, the amount of dye in the resin layer (A) is less than 50 parts by mass per 100 parts by mass of resin (a) contained in the resin layer (A). Hereinafter, the amount of dye per 100 parts by mass of resin (a) in the resin layer (A) may be referred to as "content (A1)". By limiting the content of (A1) to less than 50 parts by mass, the laminate can achieve color development commensurate with its content. Furthermore, it prevents the resin layer (A) from developing color unintentionally or the mechanical strength of the resin layer (A) from decreasing during resin layer (A) molding or laminate molding. For this reason, it can be suitably used for passports or cards. From these viewpoints, the content of (A1) is more preferably 30 parts by mass or less, even more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less, even more preferably 8 parts by mass or less, particularly preferably 6 parts by mass or less, especially preferably 4 parts by mass or less, and most preferably 2 parts by mass or less.

[0050] Furthermore, the content (A1) is preferably 0.01 parts by mass or more. By setting the content (A1) to 0.01 parts by mass or more, it becomes possible to appropriately colorize the dye by heating such as laser irradiation. From the viewpoint of improving color development, the content (A1) of the dye is more preferably 0.02 parts by mass or more, even more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, particularly preferably 0.5 parts by mass or more, especially preferably 0.7 parts by mass or more, and most preferably 0.9 parts by mass or more.

[0051] Furthermore, while it is preferable that the resin layer (A) does not contain a color developer, it may contain one. In one embodiment of the present invention, the amount of color developer in the resin layer (A) is less than 0.5 parts by mass per 100 parts by mass of resin (a). If the amount of color developer is 0.5 parts by mass or more, there is a risk that the color developer will react with the pigment blended into the resin (a) due to heating during kneading or other factors during the molding of the resin layer (A), causing it to develop color. Hereinafter, the amount of color developer in the resin layer (A) per 100 parts by mass of resin (a) may be referred to as "content (A2)". From the viewpoint of appropriately suppressing color development during molding of the resin layer (A), the content (A2) is preferably 0.35 parts by mass or less, more preferably 0.2 parts by mass or less, even more preferably 0.1 parts by mass or less, even more preferably 0.05 parts by mass or less, and particularly preferably 0.03 parts by mass or less. Furthermore, from the viewpoint of appropriately suppressing color development during molding of the resin layer (A), the less the content (A2) is, the better. Therefore, it may be 0 parts by mass or more, or 0.01 parts by mass or more. In this embodiment, "does not contain a color developer" means substantially does not contain a color developer, and also includes embodiments in which a color developer is intentionally omitted but is present as an unavoidable impurity.

[0052] The resin layer (B) of the present invention contains a resin (b) and a color developer. In the present invention, because the resin layer (B) contains a color developer, when the laminate is heated by laser irradiation or the like, and the dye, color developer, etc. are heated, the dye in the resin layer (A) is colored by the color developer in the resin layer (B). Furthermore, when resin layer (B) is directly laminated onto resin layer (A), the dye in resin layer (A) develops color at the interface between resin layer (A) and resin layer (B), or near the interface when the dye and / or developer are appropriately migrated within the laminate due to heating such as laser irradiation. Furthermore, if an intermediate resin layer (C), described later, is provided, the dye of resin layer (A) and / or the developer of resin layer (B) are heated by laser irradiation or the like and migrate appropriately within the laminate, causing the dye of resin layer (A) to develop color inside the intermediate resin layer (C), or at or near the interface between the intermediate resin layer (C) and resin layer (A) or resin layer (B).

[0053] The amount of color developer in the resin layer (B) is preferably less than 50 parts by mass per 100 parts by mass of resin (b). Hereinafter, the amount of color developer in the resin layer (B) per 100 parts by mass of resin (b) may be referred to as "content (B2)". By limiting the developer content (B2) of the laminate to less than 50 parts by mass, color development commensurate with the content becomes possible. Furthermore, it is possible to prevent the resin layer (B) from developing color unintentionally during resin layer (B) molding or laminate molding. It is also possible to prevent a decrease in the mechanical strength of the resin layer (B). For this reason, it can be suitably used for passports or cards. From these viewpoints, the developer content (B2) in the resin layer (B) is more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less, particularly preferably 8 parts by mass or less, and especially preferably 5 parts by mass or less.

[0054] Furthermore, the content of the color developer (B2) in the resin layer (B) is preferably 0.05 parts by mass or more. By setting the content (B2) to 0.05 parts by mass or more, it becomes possible to appropriately develop the color of the pigment in the resin layer (A) with the color developer blended in the resin layer (B) when marking by laser irradiation or the like. From the viewpoint of improving the color development of the laminate, the content of the color developer (B2) is more preferably 0.2 parts by mass or more, even more preferably 0.5 parts by mass or more, even more preferably 1 part by mass or more, particularly preferably 1.5 parts by mass or more, and especially preferably 2.2 parts by mass or more.

[0055] Furthermore, while it is preferable that the resin layer (B) does not contain a dye, it may contain a dye. In one embodiment of the present invention, the dye content in the resin layer (B) is less than 0.5 parts by mass per 100 parts by mass of resin (b). Hereinafter, the dye content in the resin layer (B) per 100 parts by mass of resin (b) may be referred to as "content (B1)". If the content (B1) is 0.5 parts by mass or more, the dye may react with the color developer during the molding of the resin layer (B) due to heating during resin kneading, etc., and develop color. From the viewpoint of appropriately suppressing color development during molding of the resin layer (B), the pigment content (B1) is preferably 0.1 parts by mass or less, more preferably 0.03 parts by mass or less, even more preferably 0.01 parts by mass or less, and even more preferably 0.005 parts by mass or less. Furthermore, from the viewpoint of appropriately suppressing color development during molding of the resin layer (B), the pigment content (B1) in the resin layer (B) is better the less it is, it may be 0 parts by mass or more, or 0.001 parts by mass or more. In one embodiment of the present invention, "does not contain pigment" means substantially does not contain pigment, and includes embodiments in which pigment is intentionally omitted but contains pigment as an unavoidable impurity.

[0056] It is preferable that the pigment content (B1) in the resin layer (B) is less than the pigment content (A1) in the resin layer (A). By making the pigment content (B1) less than the pigment content (A1), it is possible to more reliably suppress color development during the molding of the resin layer (B), while allowing the laminate to develop appropriate color using the pigment blended in the resin layer (A) when marking by laser irradiation or the like. From the above viewpoint, the ratio of the pigment content (B1) to the pigment content (A1) (B1 / A1) is preferably 0 or more and 0.5 or less, more preferably 0 or more and 0.1 or less, even more preferably 0 or more and 0.01 or less.

[0057] Furthermore, it is preferable that the content of the color developer (B2) in the resin layer (B) is greater than the content of the color developer (A2) in the resin layer (A). By making the content (B2) greater than the content (A2), it is possible to more reliably suppress the color development during molding of the resin layer (A), while at the same time, when marking by laser irradiation or the like, the color developer blended into the resin layer (B) makes it possible to appropriately color the pigment of the resin layer (A). From the above viewpoint, the ratio of the content (A2) to the content (B2) (A2 / B2) is preferably 0 or more and 0.5 or less, more preferably 0 or more and 0.1 or less, even more preferably 0 or more and 0.05 or less, and even more preferably 0 or more and 0.02 or less.

[0058] The ratio (A1 / B2) of the pigment content (A1) in the resin layer (A) to the color developer content (B2) in the resin layer (B) is preferably 0.01 to 3, more preferably 0.05 to 2, even more preferably 0.1 to 1.5, even more preferably 0.2 to 1.3, even more preferably 0.3 to 1.1, even more preferably 0.35 to 1, and even more preferably 0.4 to 0.8. By using such a content ratio, it becomes easier to appropriately color the laminate when marking it by laser irradiation or the like.

[0059] [Pigment] The dyes and color developers used in the present invention will be described in detail below. Examples of dyes used in the present invention include leuco dyes. Leuco dyes are usually basic, and those known in the field of pressure-sensitive or thermal recording paper can be used. The leuco dye may be colorless or pale before color development. It is preferable that the leuco dye is a leuco dye.

[0060] The thermal decomposition temperature of the dye is preferably 200°C or higher. Setting the thermal decomposition temperature of the dye to 200°C or higher allows the dye to develop color appropriately in the laminate without thermal decomposition when the resin layer (A) is molded. From the above viewpoint, the thermal decomposition temperature of the dye is more preferably 220°C or higher, even more preferably 240°C or higher, even more preferably 260°C or higher, particularly preferably 280°C or higher, and especially preferably 300°C or higher. Furthermore, the thermal decomposition temperature of the dye is not particularly limited, but is generally 360°C or lower, and may also be 355°C or lower. The thermal decomposition temperature of the pigment and the color developer described later should be defined as the temperature at which the weight decreases by 5% when thermogravimetric analysis (TGA) is performed under atmospheric pressure while increasing the temperature at a rate of 10°C / min.

[0061] Furthermore, the crystallization temperature of the dye is preferably 100°C or higher. By setting the crystallization temperature of the dye to 100°C or higher, it is possible to prevent the dye from bleeding onto the surface even when exposed to high-temperature environments during resin layer molding or when the laminate is used as a card, passport, etc. From the above viewpoint, the crystallization temperature of the dye is more preferably 120°C or higher, even more preferably 140°C or higher, even more preferably 150°C or higher, and particularly preferably 160°C or higher. The crystallization melting temperature of the dye is preferably 300°C or lower. Setting the crystallization melting temperature to 300°C or lower results in good dispersibility of the dye when molding the resin layer (A), making uneven coloring and deterioration of mechanical properties less likely to occur. From this viewpoint, the crystallization melting temperature of the dye is more preferably 260°C or lower, even more preferably 240°C or lower, even more preferably 220°C or lower, and particularly preferably 200°C or lower. The crystal melting temperatures of the dyes and the color developers described later can be determined by using a differential scanning calorimeter (DSC), heating them under a nitrogen atmosphere at a heating rate of 10°C / min, and measuring the peak top temperature of the melting peak in the detected DSC curve. In the resin layer (A), the dye is not particularly limited, but it is preferable that it is not encapsulated in a capsule or the like, and that, for example, the compound that constitutes the dye, as described later, is dispersed or miscible in the resin (a) that constitutes the resin layer (A).

[0062] Leuco dyes used as pigments are compounds that develop color when heated while bound to a color developer. Leuco dyes, in particular, include colorless or pale compounds that have partial skeletons such as lactones, lactams, saltones, spiropyrans, esters, and amides, and whose partial skeletons rapidly open or cleave when in contact with a color developer and heated.

[0063] Examples of leuco dyes include triphenylmethane-based leuco dyes, fluorane-based leuco dyes, fluorene-based leuco dyes, and divinyl-based leuco dyes. Representative colorless or light-colored dyes (dye precursors) are shown below, but are not limited to these.

[0064] Examples of triphenylmethane-based leuco dyes include 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide (referred to as "crystal violet lactone"), 3,3-bis(4-dimethylaminophenyl)phthalide (referred to as "malachite green lactone"), and 3-(4-dimethylaminophenyl)-3-(4-diethylamino-2-methylphenyl)-6-dimethylaminophthalide.

[0065] Examples of fluorane-based leuco dyes include 2-methyl-6-(Np-tolyl-N-ethylamino)fluorane, 3-N-ethyl-N-isopentylamino-7,8-benzofluorane, 3-diethylamino-6-methylfluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-(o,p-dimethylanilino)fluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-6-methyl-7-(m-trifluoromethylanilino)fluorane, and 3-diethylamino-6- Methyl-7-(o-chloroanilino)fluorane, 3-diethylamino-6-methyl-7-(p-chloroanilino)fluorane, 3-diethylamino-6-methyl-7-(o-fluoroanilino)fluorane, 3-diethylamino-6-methyl-7-(m-methylanilino)fluorane, 3-diethylamino-6-methyl-7-octylanilinofluorane, 3-diethylamino-6-methyl-7-octylaminofluorane, 3-diethylamino-6-methyl-7-benzylaminofluorane, 3-diethylamino-6-methyl-7-dibenzyl Minofluoran, 3-diethylamino-6-chloro-7-methylfluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-diethylamino-6-chloro-7-p-methylanilinofluoran, 3-diethylamino-6-ethoxyethyl-7-anilinofluoran, 3-diethylamino-7-methylfluoran, 3-diethylamino-7-chlorofluoran, 3-diethylamino-7-(m-trifluoromethylanilino)fluoran, 3-diethylamino-7-( p-chloroanilino)fluorane, 3-diethylamino-7-(o-fluoroanilino)fluorane, 3-diethylamino-benzo[a]fluorane, 3-diethylamino-benzo[c]fluorane, 3-dibutylamino-6-methyl-fluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-7-(o,p-dimethylanilino)fluorane, 3-dibutylamino-6-methyl-7-(o-chloroanilino)fluorane, 3-dibutylamino-6-methyl-7-(p-chloroanilino)fluorane,3-Dibutylamino-6-methyl-7-(o-fluoroanilino)fluorane, 3-Dibutylamino-6-methyl-7-(m-trifluoromethylanilino)fluorane, 3-Dibutylamino-6-methyl-chlorofluorane, 3-Dibutylamino-6-ethoxyethyl-7-anilinofluorane, 3-Dibutylamino-6-chloro-7-anilinofluorane, 3-Dibutylamino-6-methyl-7-p-methylanilinofluorane, 3-Dibutylamino-7-(o-chloroanilino)fluorane, 3-Dibutylamino-7-(o-fluoroani Fluoran, 3-di-pentylamino-6-methyl-7-anilinofluoran, 3-di-pentylamino-6-methyl-7-(p-chloroanilino)fluoran, 3-di-pentylamino-7-(m-trifluoromethylanilino)fluoran, 3-di-pentylamino-6-chloro-7-anilinofluoran, 3-di-pentylamino-7-(p-chloroanilino)fluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, 3-piperidino-6-methyl-7-anilinofluoran, 3-(N-methyl-N-propylamino)- 6-methyl-7-anilinofluorane, 3-(N-methyl-N-cyclohexylamino)-6-methyl-7-anilinofluorane, 3-(N-ethyl-N-cyclohexylamino)-6-methyl-7-anilinofluorane, 3-(N-ethyl-N-xylamino)-6-methyl-7-(p-chloroanilino)fluorane, 3-(N-ethyl-p-toluidino)-6-methyl-7-anilinofluorane, 3-(N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluorane, 3-(N-ethyl-N-isoamylamino)-6-chloro- 7-anilinofluorane, 3-(N-ethyl-N-tetrahydrofurfurylamino)-6-methyl-7-anilinofluorane, 3-(N-ethyl-N-isobutylamino)-6-methyl-7-anilinofluorane, 3-(N-ethyl-N-ethoxypropylamino)-6-methyl-7-anilinofluorane, 3-cyclohexylamino-6-chlorofluorane, 2-(4-oxahexyl)-3-dimethylamino-6-methyl-7-anilinofluorane, 2-(4-oxahexyl)-3-diethylamino-6-methyl-7-anilinofluorane,2-(4-oxahexyl)-3-dipropylamino-6-methyl-7-anilinofluorane, 2-methyl-6-p-(p-dimethylaminophenyl)aminoanilinofluorane, 2-methoxy-6-p-(p-dimethylaminophenyl)aminoanilinofluorane, 2-chloro-3-methyl-6-p-(p-phenylaminophenyl)aminoanilinofluorane, 2-chloro-6-p-(p-dimethylaminophenyl)aminoanilinofluorane, 2-nitro-6-p-(p-diethylaminophenyl)aminoani Linofluoran, 2-amino-6-p-(p-diethylaminophenyl)aminoanilinofluoran, 2-diethylamino-6-p-(p-diethylaminophenyl)aminoanilinofluoran, 2-phenyl-6-methyl-6-p-(p-phenylaminophenyl)aminoanilinofluoran, 2-benzyl-6-p-(p-phenylaminophenyl)aminoanilinofluoran, 2-hydroxy-6-p-(p-phenylaminophenyl)aminoanilinofluoran, 3-methyl-6-p-(p-dimethylamino Phenylaminoanilinofluorane, 3-diethylamino-6-p-(p-diethylaminophenyl)aminoanilinofluorane, 3-diethylamino-6-p-(p-dibutylaminophenyl)aminoanilinofluorane, 2,4-dimethyl-6-[(4-dimethylamino)anilino]fluorane, 3,6-dimethoxyfluorane, 3-dimethylamino-7-methoxyfluorane, 3-diethylamino-6-methoxyfluorane, 3-diethylamino-7-methoxyfluorane, 3-diethylamino-6,7-di Examples include methyl fluorane, 3-N-cyclohexyl-Nn-butylamino-7-methylfluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-octylaminofluorane, 3-diethylamino-7-di-n-hexylaminofluorane, 3-diethylamino-7-anilinofluorane, 3,6-bis(diethylamino)fluorane-γ-(3'-nitro)anilinolactam, and 3,6-bis(diethylamino)fluorane-γ-(4'-nitro)anilinolactam.

[0066] Examples of fluorene-based leuco dyes include 3,6,6'-tris(dimethylamino)spiro[fluorene-9,3'-phthalide] and 3,6,6'-tris(diethylamino)spiro[fluorene-9,3'-phthalide]. Examples of divinyl leuco dyes include 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrabromophthalide; 3,3-bis[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl]-4,5,6,7-tetrachlorophthalide; 3,3-bis[1,1-bis(4-pyrrolidinophenyl)ethylene-2-yl]-4,5,6,7-tetrabromophthalide; and 3,3-bis[1-(4-methoxyphenyl)-1-(4-pyrrolidinophenyl)ethylene-2-yl]-4,5,6,7-tetrachlorophthalide.

[0067] In addition, as leuco dyes, there are 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(4-diethylamino-2-ethoxyphenyl)-3-(1-octyl-2-methylindole-3-yl)-4-azaphthalide, 3-(4-cyclohexylethylamino-2-methoxyphenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, and 3-(2-methyl-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole Lu-3-yl)-4-azaphthalide, 3-(2-n-propoxycarbonylamino-4-di-n-propylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-methylamino-4-di-n-propylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-methyl-4-di-n-hexylaminophenyl)-3-(1-n-octyl-2-methylindole-3-yl)-4,7-diazaphthalide, 3,3-bis(2-ethoxy-4- Diethylaminophenyl)-4-azaphthalide, 3,3-bis(1-n-octyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-octyl-2-methylindole-3-yl)-4 or 7-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4 or Other examples include azaphthalide-based leuco dyes such as 7-azaphthalide, 3-(2-hexyloxy-4-diethylaminophenyl)-3-(1-ethyl-2-methylindole-3-yl)-4 or 7-azaphthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-ethyl-2-phenylindole-3-yl)-4 or 7-azaphthalide, 3-(2-butoxy-4-diethylaminophenyl)-3-(1-ethyl-2-phenylindole-3-yl)-4 or 7-azaphthalide 3-methyl-spiro-dinaphthopyran.

[0068] Also, 3-(4-dimethylaminophenyl)-3-(1,2-dimethylindole-3-yl)phthalide, 3-(4-dimethylaminophenyl)-3-(2-methylindole-3-yl)phthalide, 3,3-bis(1,2-dimethylindole-3-yl)-5-dimethylaminophthalide, 3,3-bis(1,2-dimethylindole-3-yl)-6-dimethylaminophthalide, 3,3-bis(9-ethylcarbazole-3-yl)-6-dimethylaminophthalide, 3,3-bis(2-phenylindole-3-yl)-6-dimethylaminophthalide, 3-(4-dimethylaminophenyl)-3-(1-methylpyrrole-3-yl)-6-dimethylaminophthalide Other examples include 3-[1,1-di(1-ethyl-2-methylindole-3-yl)ethylene-2-yl]-3-(4-diethylaminophenyl)phthalide, 3-[1,1-di(1-ethyl-2-methylindole-3-yl)ethylene-2-yl]-3-(4-N-ethyl-N-phenylaminophenyl)phthalide, 3-(2-ethoxy-4-diethylaminophenyl)-3-(1-n-octyl-2-methylindole-3-yl)phthalide, 3,3-bis(1-n-octyl-2-methylindole-3-yl)phthalide, and 3-(2-methyl-4-diethylaminophenyl)-3-(1-n-octyl-2-methylindole-3-yl)phthalide. Furthermore, 3-ethyl-spiro-dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho-(3-methoxybenzo)spiropyran, 2'-anilino-6'-(N-ethyl-N-isopentyl)amino-3'-methylspiro[isobenzofuran-1(3H),9'-(9H)xanthene-3-one, 2'-anilino-6'-(N-ethyl-N-(4-methylphenyl))amino-3'- Other examples include methylspiro[isobenzofuran-1(3H),9'-(9H)xanthene]-3-one, 3'-N,N-dibenzyloamino-6'-N,N-diethylaminospiro[isobenzofuran-1(3H),9'-(9H)xanthene]-3-one, and 2'-(N-methyl-N-phenyl)amino-6'-(N-ethyl-N-(4-methylphenyl))aminospiro[isobenzofuran-1(3H),9'-(9H)xanthene]-3-one.

[0069] The dye contained in resin layer (A) may be one of the above-mentioned dyes used alone, or two or more dyes may be used in combination. Furthermore, if a dye is contained in resin layer (B), the dye contained in resin layer (B) may be one of the above-mentioned dyes used alone, or two or more dyes may be used in combination. The dye contained in resin layer (B) may be the same compound as the dye contained in resin layer (A), or a different compound. However, it is preferable that the dyes contained in both resin layers (A) and (B) be those that can develop color by reacting with the color developer contained in resin layer (B).

[0070] [Color developer] A color developer should be one that reacts with the above-mentioned dye upon heating, causing the dye to develop color. Color developers are usually electron-accepting, and electron-accepting color developers react with the basic leuco dyes mentioned above.

[0071] The thermal decomposition temperature of the color developer is preferably 200°C or higher. Setting the thermal decomposition temperature of the color developer to 200°C or higher allows the color developer to properly develop the pigment in the laminate without thermal decomposition during the molding of the resin layer (B). From this viewpoint, the thermal decomposition temperature of the color developer is more preferably 220°C or higher, even more preferably 240°C or higher, and particularly preferably 260°C or higher. Furthermore, the thermal decomposition temperature of the color developer is not particularly limited, but is generally 370°C or lower, and may also be 365°C or lower.

[0072] The crystal melting temperature of the color developer is preferably 100°C or higher. By setting the crystal melting temperature of the color developer to 100°C or higher, it becomes easier to prevent the color developer from bleeding onto the surface even when exposed to high-temperature environments during resin layer molding or when the laminate is used as a card, passport, etc. From the above viewpoint, the crystal melting temperature of the color developer is more preferably 120°C or higher, even more preferably 130°C or higher, and particularly preferably 140°C or higher. Furthermore, the crystal melting temperature of the color developer is preferably 300°C or lower. Setting the crystal melting temperature to 300°C or lower improves the dispersibility of the color developer when molding the resin layer (B), making uneven coloring and deterioration of mechanical properties less likely to occur. From the above viewpoint, the crystal melting temperature of the color developer is more preferably 280°C or lower, even more preferably 260°C or lower, even more preferably 240°C or lower, particularly preferably 220°C or lower, and especially preferably 200°C or lower. In the resin layer (B), the color developer is not particularly limited, but it is preferable that the compound constituting the color developer, as described later, is dispersed or miscible in the resin (b), rather than being encapsulated in a capsule or the like.

[0073] Preferred examples of color developers include triazine compounds, bisphenol compounds, urea compounds, novolac-type phenol compounds, and organic halogen compounds. Examples of the triazine compound include, for example, a compound represented by the following formula (4). Note that the compound represented by the following formula (4) generally has tautomers, and the triazine compound is at least one of the compound represented by the following formula (4) and its tautomers.

[0074]

Chemical formula

Chemical formula

[0075] Examples of bisphenol compounds include 4,4'-isopropylidenediphenol, 2,2'-bis(4-hydroxy-3-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 4,4'-dihydroxydiphenyl sulfide, di(4-hydroxy-3-methylphenyl) sulfide, 2,2'-thiobis(3-tert-octylphenol), 2,2'-thiobis(4-tert-octylphenol), 4,4'-dihydroxydiphenylsulfone, and 2,4'-dihydroxydiphenylsulfone. Examples include rufone, 4-hydroxy-4'-n-propoxydiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-4'-allyloxydiphenylsulfone, bis(3-allyl-4-hydroxyphenyl)sulfone, 4-hydroxyphenyl-4'-benzyloxyphenylsulfone, 3,4-dihydroxyphenyl-4'-methylphenylsulfone, 2,4-bis(phenylsulfonyl)phenol, bisphenol sulfone crosslinked compounds described in Japanese Patent No. 3913820, and bisphenol sulfone derivatives described in Japanese Patent No. 4004289.

[0076] Examples of urea compounds include 4,4'-bis(3-(phenoxycarbonylamino)methylphenylureido)diphenylsulfone, N-(p-toluenesulfonyl)-N'-(3-p-toluenesulfonyloxyphenyl)urea described in Japanese Patent No. 4601174, 4,4'-bis(3-tosylureido)diphenylmethane described in Japanese Patent Publication No. 2011-105638, and N-[2 -(3-phenylureido)phenyl]benzenesulfonamide, N-[2-(acetoxy)phenyl]-N'-phenylurea, N-[3-(acetoxy)phenyl]-N'-phenylurea, N-[2-(benzoyloxy)phenyl]-N'-phenylurea, N-[3-(benzoyloxy)phenyl]-N'-phenylurea, N-[3-(benzoyloxy)phenyl]-N'-phenylurea, described in International Publication No. 2017 / 047572 Examples include amino acid derivatives such as N-(m-tolylaminocarbonyl)-phenylalanine, N-(p-toluenesulfonyl)-phenylalanine, N-(benzyloxycarbonyl)-valine, N-(m-tolylaminocarbonyl)-methionine, N-(m-tolylaminocarbonyl)-tyrosine, N-(m-tolylaminocarbonyl)-phenylglycine, N-(m-tolylaminocarbonyl)-valine, N-(m-tolylaminocarbonyl)-cysteine-S-benzyl, N-(m-tolylaminocarbonyl)-β-alanine, N-phenylaminothiocarbonyl-glycylglycine, N-(p-toluenesulfonylaminocarbonyl)-phenylalanine-methyl ester, N-(p-toluenesulfonyl)-β-alanine, N-(p-tolylaminocarbonyl)-methionine, and N-(phenylaminocarbonyl)-methionine. Examples of novolac-type phenolic compounds include phenol-formaldehyde condensates described in International Publication No. 02 / 098674.

[0077] Examples of organic halogen compounds include aromatic halogen compounds and aliphatic halogen compounds, with aromatic halogen compounds being preferred. Examples of aromatic halogen compounds include dibromobenzene, hexabromobenzene, pentabromotoluene, pentabromodiphenyl ether, dichlorobenzene, and hexachlorobenzene.

[0078] In addition to the compounds listed above, other colorants include inorganic acidic substances such as activated clay, attapulgite, colloidal silica, and aluminum silicate, hydroquinone monobenzyl ether, benzyl 4-hydroxybenzoate, aminobenzenesulfonamide derivatives described in Japanese Patent Publication No. 8-59603, bis(4-hydroxyphenylthioethoxy)methane, 1,5-di(4-hydroxyphenylthio)-3-oxapentane, bis(p-hydroxyphenyl)butyl acetate, bis(p-hydroxyphenyl)methyl acetate, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,4-bis[α-methyl-α-(4'-hydroxyphenyl)ethyl]benzene, 1,3-bis[α-methyl-α-(4'-hydroxyphenyl)ethyl]benzene, and International Publication No. 02 / 081 Examples include compounds described in Japanese Patent Publication No. 229 and Japanese Patent Application Publication No. 2002-301873, thiourea compounds such as N,N'-di-m-chlorophenylthiourea, p-chlorobenzoic acid, stearyl gallate, bis[4-(octyloxycarbonylamino)zinc salicylate]dihydrate, 4-[2-(p-methoxyphenoxy)ethyloxy]salicylic acid, 4-[3-(p-tolylsulfonyl)propyloxy]salicylic acid, and 5-[p-(2-p-methoxyphenoxyethoxy)cumyl]salicylic acid, as well as salts of these aromatic carboxylic acids with polyvalent metal salts such as zinc, magnesium, aluminum, calcium, titanium, manganese, tin, and nickel, and also antipyrine complexes of zinc thiocyanate and complex zinc salts of terephthalaldehyde and other aromatic carboxylic acids. Examples include metal chelate complexes such as metal double salts of higher fatty acids and polyvalent hydroxyaromatic compounds described in Japanese Patent Publication No. 10-258577.

[0079] In the present invention, the color developer contained in the resin layer (B) may be one of the above-mentioned components used alone, or two or more components may be used in combination. Furthermore, if the color developer is contained in the resin layer (A), the color developer contained in the resin layer (A) may be one of the above-mentioned components used alone, or two or more components may be used in combination. In addition, the color developer contained in the resin layer (A) may be the same compound as the color developer contained in the resin layer (B), or it may be a different compound, but it is preferable that the color developers contained in the resin layers (A) and (B) react with the dye contained in the resin layer (A) to produce color in the dye.

[0080] [Light and heat converter] The laminate of the present invention is preferably capable of developing color by laser irradiation. Specifically, it is preferable to heat at least a portion of the laminate by laser irradiation so that the developer and the dye react due to the heating and the dye develops color. To achieve such a configuration, for example, a photothermal converter may be included in the laminate. The photothermal converter converts the light energy absorbed by laser irradiation into heat, thereby heating at least a portion of the laminate.

[0081] In the present invention, it is preferable that at least one of the resin layer (A) and resin layer (B) contains a photothermal converter. In the laminate, at least one of the resin layer (A) and resin layer (B) contains a photothermal converter, so that when laser irradiation is performed, at least one of the resin layer (A) and resin layer (B) and its surrounding area are heated, and the color developer and dye are also heated. As a result, the heated color developer and dye react and produce color mainly at the interface between the resin layer (A) and the resin layer (B), or in its vicinity (however, if there is an intermediate resin layer (C) described later, the inside of the intermediate resin layer (C), or the interface between at least one of the resin layer (A) and the resin layer (B) and the resin layer (C) and its vicinity). The photothermal converter may be contained in resin layer (A) or in resin layer (B). Furthermore, from the viewpoint of rapidly heating the color developer and dye by laser irradiation to cause the dye to develop color, it is more preferable to contain the photothermal converter in both resin layer (A) and resin layer (B).

[0082] The photothermal conversion agent is not particularly limited, but any agent that absorbs light in the wavelength range of 300 to 3500 nm, preferably 350 to 3000 nm, and generates heat is acceptable. However, from the viewpoint of photothermal conversion efficiency, a near-infrared absorber with a maximum absorption peak in the wavelength range of 400 to 3000 nm is preferred. Organic dyes are preferred as near-infrared absorbers. Examples of organic dyes include cyanine dyes, phthalocyanine dyes, naphthalocyanine dyes, squarylium dyes, quinone dyes, polymethine dyes, diimonium dyes, azo dyes, phenylenediamine dyes, diphenylmethane, triphenylmethane dyes, pyrrolopyrrole dyes, and metal complex dyes. Among these, phthalocyanine dyes, diimonium dyes, and squarylium dyes are preferred in terms of their excellent durability. Furthermore, the maximum value of the absorption peak of the photothermal converter is not particularly limited, but is more preferably 300 to 2500 nm, even more preferably 400 to 2000 nm (relatively high energy), even more preferably 500 to 1500 nm, even more preferably 580 to 1300 nm, and particularly preferably 650 to 1100 nm.

[0083] Commercially available products can also be used as light-to-heat converters. Examples of commercially available light-to-heat converters that can be used include: "ABS-626", "ABS-642", "ABS643", "ABS654", "ABS667", "ABS670T", "ABS-699", "IRA-677", "IRA693N", "IRA735", "IRA800", "IRA850", "IRA868" (manufactured by Exciton); "TAP-15", "IR-706" (manufactured by Yamada Chemical Industry); "PD-320", "YKR-2900", "YKR-3080" (manufactured by Yamamoto Chemical Co., Ltd.); "IR-1", "IR-10A", "IR-12", "IR-14", "TX-EX906B", "TX-EX910B" (manufactured by Nippon Shokubai Co., Ltd.); "Kayasorb IRG-068", "Kayasorb IRG-069", "Kayasorb Examples include "IRG-079" (manufactured by Nippon Kayaku Co., Ltd.), "CIR-1085", "CIR-RL" (manufactured by Nippon Carlit Co., Ltd.), "Lumogen IR765", "Lumogen IR788" (manufactured by BASF). Among these, "IRA-677", "ABS-626", and "ABS-699" are preferred due to their low absorption in the visible light region.

[0084] Furthermore, as a photothermal conversion agent, those known as ultraviolet absorbers, which can be used as other additives as described later, can also be used.

[0085] The photothermal converters contained in each of the resin layers (A) and (B) may be one type alone from the above, or two or more components may be used in combination. When photothermal converters are contained in both resin layers (A) and (B), the photothermal converter contained in resin layer (A) may be the same compound as the dye contained in resin layer (B), or it may be a different compound.

[0086] When the resin layer (A) contains a photothermal converter, the content of the photothermal converter in the resin layer (A) is preferably 0.0005 parts by mass or more and 1 part by mass or less, more preferably 0.001 parts by mass or more and 0.5 parts by mass or less, even more preferably 0.003 parts by mass or more and 0.3 parts by mass or less, and particularly preferably 0.005 parts by mass or more and 0.1 parts by mass or less, per 100 parts by mass of resin (a). When the content of the photothermal converter in the resin layer (A) is 0.0005 parts by mass or more, the resin layer (A) and its surroundings are rapidly heated by laser irradiation, and the dye can be appropriately colored. Furthermore, by setting it to 1 part by mass or less, an effect commensurate with the content can be obtained, and it is easier to ensure the mechanical strength and transparency of the resin layer (A). If the resin layer (B) contains a photothermal converter, the amount of photothermal converter in the resin layer (B) is preferably 0.0005 parts by mass or more and 1 part by mass or less, more preferably 0.001 parts by mass or more and 0.5 parts by mass or less, even more preferably 0.003 parts by mass or more and 0.3 parts by mass or less, and particularly preferably 0.005 parts by mass or more and 0.1 parts by mass or less, per 100 parts by mass of resin (b).

[0087] [Sensitizer] The resin layer (A) may contain a sensitizer. The resin layer (B) may also contain a sensitizer. Either one of the resin layers (A) or (B) may contain a sensitizer, or both may contain a sensitizer. The sensitizer is not particularly limited, but examples include 1,2-di-(3-methylphenoxy)ethane, 2-benzyloxynaphthalene, fatty acid amides with 10 to 21 carbon atoms (e.g., stearic acid amide, palmitic acid amide, etc.), ethylenebisamide, montanic acid wax, polyethylene wax, p-benzylbiphenyl, diphenylsulfone, 4-biphenyl-p-tolyl ether, m-terphenyl, 1,2-diphenoxyethane, dibenzyl oxalate, di(p-chlorobenzyl) oxalate, di(p-methylbenzyl) oxalate, dibenzyl terephthalate, and p-benzyloxyanaphthalene. Benzyl bisphosphonate, di-p-tolyl carbonate, phenyl-α-naphthyl carbonate, 1,4-diethoxynaphthalene, phenyl 1-hydroxy-2-naphthoate, o-xylene-bis-(phenyl ether), 4-(m-methylphenoxymethyl)biphenyl, 4,4'-ethylenedioxy-bis-benzoate dibenzyl ester, dibenzoyloxymethane, 1,2-di(3-methylphenoxy)ethylene, bis[2-(4-methoxyphenoxy)ethyl] ether, p-methyl p-nitrobenzoate, p-toluenesulfonate phenyl, etc. can be used. Among these, 1,2-di-(3-methylphenoxy)ethane, 1,2-diphenoxyethane, fatty acid amides having 10 to 21 carbon atoms (e.g., stearic acid amide, palmitic acid amide, etc.), 2-benzyloxynaphthalene, diphenyl sulfone, p-toluenesulfonamide, and di-p-methylbenzyl oxalate are preferred, with 1,2-di-(3-methylphenoxy)ethane being particularly preferred as it exhibits high color development sensitivity even at low energy levels.

[0088] In each resin layer (A) and (B), only one type of sensitizer may be used, or two or more types may be used in combination. Furthermore, if both resin layers (A) and (B) contain a sensitizer, the sensitizer contained in resin layer (A) may be the same compound as the sensitizer contained in resin layer (B), or it may be a different compound. When the resin layer (A) contains a sensitizer, the amount of sensitizer in the resin layer (A) is preferably 25 parts by mass or more and 250 parts by mass or less, and more preferably 50 to 150 parts by mass, per 100 parts by mass of the dye contained in the resin layer (A). Furthermore, if the resin layer (B) contains a sensitizer, the amount of sensitizer in the resin layer (B) is preferably 25 to 250 parts by mass, and more preferably 50 to 150 parts by mass, per 100 parts by mass of the color developer contained in the resin layer (B).

[0089] [Compound (X)] The resin layer (A) may contain compound (X) having a first acid dissociation constant (pKa) of 9 or higher. Similarly, the resin layer (B) may contain compound (X) having a first acid dissociation constant (pKa) of 9 or higher. One of the resin layers (A) and (B) may contain compound (X), or both may contain compound (X). Having compound (X) in at least one of the resin layers (A) and (B) tends to suppress the bleed-out of dyes and color developers in the resin layer containing compound (X).

[0090] The first acid dissociation constant (pKa) of compound (X) is the value obtained when the solvent is water at 25°C. For example, it can be measured by the method described in The Journal of Physical Chemistry vol.68, number 6, page 1560 (1964), or by using a potentiometric automatic titrator (such as COM-980Win) manufactured by Hiranuma Sangyo Co., Ltd. Alternatively, values ​​from databases such as the acid dissociation index described in the Chemical Handbook of the Chemical Society of Japan (revised 3rd edition, published June 25, 1984 by Maruzen Co., Ltd.) or pKaBASE manufactured by Compudrug can be used. Note that the first acid dissociation constant (pKa) of a multi-step ionization compound refers to the pKa value at the first stage of ionization.

[0091] Specific examples of compound (X) include metal hydroxides such as sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide; organic ammonium salts such as tetramethylammonium hydroxide (TMAH), ammonium acetate, and ammonium formate; organic potassium salts such as potassium acetate and potassium formate; monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-methyl-N,N-diethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N-(β-aminoethyl)ethanolamine, and N-ethylethanolamine. Examples of amines include alkanolamines such as monopropanolamine, dipropanolamine, trippropanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine; primary amines such as methylamine, ethylamine, propylamine, butylamine, pentylamine, and 1,3-propanediamine; secondary amines such as piperidine and piperazine; and various amines such as tertiary amines such as trimethylamine and triethylamine ammonia; as well as potassium iodide, sodium thiosulfate, iron oxide, tin chloride, sodium cyanoborohydride, lithium borohydride, and sodium borohydride. These compounds (X) may be used individually or as a mixture of two or more.

[0092] Among these compounds (X), it is more preferable that at least one is selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonia, ammonium acetate, potassium acetate, ammonium formate, and potassium formate, with potassium acetate being the most preferred. When each resin layer (A) and (B) contains compound (X), the content of compound (X) in each resin layer (A) and (B) is preferably 0.001 parts by mass or more and 10 parts by mass or less, more preferably 0.002 parts by mass or more and 5 parts by mass or less, even more preferably 0.003 parts by mass or more and 3 parts by mass or less, and particularly preferably 0.005 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the resin (resin (a) or resin layer (b)) constituting each resin layer.

[0093] [Other additives] Each resin layer (A) and (B) may contain one or more additives selected from heat stabilizers, antioxidants, ultraviolet absorbers, etc., in addition to those mentioned above. Furthermore, resin layers (A) and (B) may also contain other known additives as appropriate.

[0094] (Heat stabilizer) The thermal stability of each resin layer can be enhanced by including a heat stabilizer in one or both of the resin layers (A) and (B). Examples of heat stabilizers include phosphorus compounds. Known phosphorus compounds can be used. Specific examples include phosphorus oxoacids such as phosphoric acid, phosphonic acid, phosphinic acid, phosphinic acid, and polyphosphate; acidic pyrophosphate metal salts such as sodium acidic pyrophosphate, potassium acidic pyrophosphate, and calcium acidic pyrophosphate; phosphates of Group 1 or Group 2B metals such as potassium phosphate, sodium phosphate, cesium phosphate, and zinc phosphate; organic phosphite compounds; and organic phosphonite compounds. In addition, metal salts of organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds may also be used.

[0095] Examples of organic phosphite compounds include triphenyl phosphite, tris(mononylphenyl) phosphite, tris(mononyl / dinonylphenyl) phosphite, tris(2,5-di-tert-butylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris[2,4-bis(1,1-dimethylpropyl)phenyl] phosphite, tris(mono / di-tert-butylphenyl) phosphite, monooctyldiphenyl phosphite, dioctylmonophenyl phosphite, monodecyldiphenyl phosphite, and didecylmonophenyl phosphate. Examples of various phosphite esters include tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl)octyl phosphite, 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl-di-tridecyl phosphite), cyclic neopentanetetraylbis(2,6-di-t-butyl-4-methylphenyl phosphite), and 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane. Among these, trialkyl phosphites such as tristearyl phosphite are preferred.

[0096] Furthermore, as the organic phosphite compound, a phosphite ester having at least one oxetane group can also be used. Such an oxetane-containing phosphite ester may have one, two, or three oxetane groups. Examples of oxetane group-containing phosphite esters include tris[(3-ethyloxetane-3-yl)methyl]phosphite, bis[(3-ethyloxetane-3-yl)methyl]phosphite, mono[(3-ethyloxetane-3-yl)methyl]phosphite, tris[(3-pentyloxetane-3-yl)methyl]phosphite, bis[(3-pentyloxetane-3-yl)methyl]phosphite, and tris[(3-hexade] [Syloxetan-3-yl)methyl]phosphite, bis[(3-hexadecyloxetan-3-yl)methyl]phosphite, tris[(3-phenyloxetan-3-yl)methyl]phosphite, bis[(3-phenyloxetan-3-yl)methyl]phosphite, tris[(3-p-tolyloxetan-3-yl)methyl]phosphite, bis[(3-p-tolyloxetan-3-yl)methyl]phosphite, Tris[(3-benzyloxetan-3-yl)methyl]phosphite, bis[(3-benzyloxetan-3-yl)methyl]phosphite, phenylbis[(3-ethyloxetan-3-yl)methyl]phosphite, 2-phenoxyspiro(1,3,2-dioxaphospholinane-5,3'-oxetane), 3,3-bis[spiro(oxetane-3',5”-(1,3,2”-dioxa-2”-phospholinane))- These are oxymethyl]oxetane and P,P'-[(1-methylethylidene)-di-4,1-phenylene]-P,P,P',P'-tetrakis[(3-ethyl-3-oxetanyl)methyl]phosphite. Oxetane group-containing phosphite esters described in U.S. Patent No. 3,209,013 can also be used as appropriate. Using oxetane group-containing phosphite esters makes it easier to increase the color intensity after the dye has developed.

[0097] The organic phosphate compound is preferably an organic phosphate ester compound or a metal salt of an organic phosphate ester compound, and as the metal, at least one metal selected from Ia, IIa, IIb, IIIa, and IIIb of the periodic table is more preferably, among which magnesium, barium, calcium, zinc, and aluminum are even more preferably, and magnesium, calcium, or zinc are particularly preferred. Furthermore, as organic phosphate ester compounds, acidic organic phosphate esters and their metal salts are preferred. Examples of acidic organic phosphate esters include dialkyl acid phosphates, monoalkyl acid phosphates, diaryl acid phosphates, and monoalkyl monoaryl acid phosphates, among which dialkyl acid phosphates and monoalkyl acid phosphates are preferred. The alkyl group in the acidic organic phosphate ester is, for example, an alkyl group having 1 to 30 carbon atoms, but the number of carbon atoms is preferably 2 to 25, more preferably 6 to 23. The number of carbon atoms in the aryl group may be around 6 to 30.

[0098] Preferred examples of organophosphate ester compounds include bis(distearyl acid phosphate) zinc salt, monostearyl acid phosphate zinc salt, tris(distearyl acid phosphate) aluminum salt, a salt of monostearyl acid phosphate and two monostearyl acid phosphate aluminum salts, monostearyl acid phosphate, distearyl acid phosphate, and the like. Among these, bis(distearyl acid phosphate) zinc salt and monostearyl acid phosphate zinc salt are more preferred.

[0099] Examples of organic phosphonite compounds include tetrakis(2,4-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-n-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,4-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, and tetrakis(2,4-di-tert-butylphenyl)-3,3'-biphenylenediphosphona Examples include tetrakis(2,6-di-iso-propylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-n-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,4'-biphenylenediphosphonite, tetrakis(2,6-di-tert-butylphenyl)-4,3'-biphenylenediphosphonite, and tetrakis(2,6-di-tert-butylphenyl)-3,3'-biphenylenediphosphonite.

[0100] Among the phosphorus compounds mentioned above, organic phosphite compounds are preferred from the viewpoint of improving thermal stability and suppressing oxidation. Furthermore, organic phosphite compounds are preferably used in combination with antioxidants, which will be described later, and specifically, combination with phenolic antioxidants is preferred. By using them in combination with phenolic antioxidants, it is possible to effectively suppress molecular weight reduction and yellowing of the resin during extrusion film formation. In addition, it is possible to achieve both stability during extrusion film formation and long-term stability as a molded product (laminated body).

[0101] Furthermore, the above-mentioned phosphorus-based compounds can also be used as transesterification inhibitors that can suppress the transesterification reaction between polyester resin and polycarbonate resin. Therefore, when one of resins (a) and (b) contains polyester resin and the other of resins (a) and (b) contains polycarbonate resin, or when polyester resin and polycarbonate resin are used in combination in one or both of resins (a) and (b), the above-mentioned phosphorus-based compounds can suppress the transesterification reaction and further improve thermal stability. Moreover, when used as passports or cards, it is also possible to suppress transesterification with polyester resin or polycarbonate resin constituting layers adjacent to the laminate, such as the core sheet and protective layer described later. Among the above-mentioned phosphorus-based compounds, organic phosphate compounds are preferred because they can suppress the transesterification reaction.

[0102] In each resin layer (A) and (B), only one type of heat stabilizer may be used, or two or more types may be used in combination. Furthermore, if both resin layers (A) and (B) contain a heat stabilizer, the heat stabilizer contained in resin layer (A) may be the same compound as the heat stabilizer contained in resin layer (B), or it may be a different compound. When each resin layer (A) and (B) contains a heat stabilizer, the amount of heat stabilizer in each resin layer (A) and (B) is preferably 0.001 parts by mass or more and 5 parts by mass or less, more preferably 0.01 parts by mass or more and 1 part by mass or less, even more preferably 0.05 parts by mass or more and 0.7 parts by mass or less, and particularly preferably 0.1 parts by mass or more and 0.5 parts by mass or less, per 100 parts by mass of the resin (resin (a) or resin layer (b)) constituting each resin layer.

[0103] [Antioxidant] As antioxidants, for example, phenolic antioxidants and sulfuric antioxidants can be used. Among these, phenolic antioxidants are preferred. The antioxidant may be contained in either resin layer (A) or resin layer (B), or in both.

[0104] Examples of phenolic antioxidants include α-tocopherol, 4-methoxyphenol, 4-hydroxyphenyl (meth)acrylate, β-tocopherol, 2,6-di-tert-butylphenol, 2,6-di-tert-4-methoxyphenol, 2-tert-butyl-4-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol (dibutylhydroxytoluene, BHT), and stearyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate. Among these, 2,6-di-tert-butyl-4-methylphenol (dibutylhydroxytoluene, BHT) is preferred.

[0105] Examples of sulfur-based antioxidants include thiodipropionic acid, dilauryl thiodipropionate, distearyl thiodipropionate, lauryl stearyl thiodipropionate, dimyristyl thiodipropionate, distearyl-β,β'-thiodibutyrate, thiobis(β-naphthol), thiobis(N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, and nickel dibutyldithiocarbamate.

[0106] In both resin layer (A) and resin layer (B), only one type of antioxidant may be used, or two or more types may be used in combination. Furthermore, if antioxidants are contained in both resin layers (A) and (B), the antioxidant contained in resin layer (A) may be the same compound as the antioxidant contained in resin layer (B), or it may be a different compound. When each resin layer (A) and (B) contains an antioxidant, the antioxidant content in each resin layer (A) and (B) is preferably 0.01 parts by mass or more and 4 parts by mass or less, more preferably 0.03 parts by mass or more and 2 parts by mass or less, even more preferably 0.05 parts by mass or more and 1 part by mass or less, and particularly preferably 0.08 parts by mass or more and 0.5 parts by mass or less, per 100 parts by mass of the resin constituting each resin layer (resin (a) or resin layer (b)).

[0107] [UV absorber] The resin layer (A) may contain a UV absorber. The resin layer (B) may also contain a UV absorber. One of the resin layers (A) and the resin layer (B) may contain a UV absorber, or both may contain a UV absorber. By including a UV absorber in at least one of the resin layers (A) or (B), light resistance and weather resistance can be improved, and light degradation of cards and passports manufactured using this laminate can be suppressed.

[0108] Organic UV absorbers such as benzotriazole-based UV absorbers, hydroxyphenyltriazine-based UV absorbers, and cyclic iminoester-based UV absorbers can be used as UV absorbers. Examples of benzotriazole-based UV absorbers include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-benzotriazole, 2-(2'-hydroxy-3',5'-bis(α,α'-dimethylbenzyl)phenylbenzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole, 2-( Examples of such compounds include 2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2,2'methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazole-2-yl)phenol], and methyl-3-[3-t-butyl-5-(2H-benzotriazole-2-yl)-4-hydroxyphenylpropionate-polyethylene glycol condensates.

[0109] Examples of hydroxyphenyltriazine-based UV absorbers include 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-hexyloxyphenol and 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl)-5-hexyloxyphenol. Examples of cyclic iminoester-based ultraviolet absorbers include 2,2'-p-phenylenebis(3,1-benzoxazine-4-one), 2,2'-m(2)-phenylenebis(3,1-benzoxazine-4-one), and 2,2'-4,4'-diphenylenebis(3,1-benzoxazine-4-one). In addition, other UV absorbers that can be used include organic UV absorbers such as benzophenone-based UV absorbers, salicylate-based UV absorbers, cyanoacrylate compounds, oxanilide-based UV absorbers, and malonic acid ester-based UV absorbers. Furthermore, inorganic UV absorbers such as cerium oxide and zinc oxide can also be used. Furthermore, to improve stability against light, light stabilizers such as hindered amines, nickels, and benzoates can also be used.

[0110] In each resin layer (A) and (B), only one type of UV absorber may be used, or two or more types may be used in combination. Furthermore, if UV absorbers are contained in both resin layers (A) and (B), the UV absorber contained in resin layer (A) may be the same compound as the UV absorber contained in resin layer (B), or it may be a different compound. When each resin layer (A) and (B) contains an ultraviolet absorber, the amount of ultraviolet absorber in each resin layer (A) and (B) is preferably 0.001 parts by mass or more and 5 parts by mass or less, more preferably 0.01 parts by mass or more and 1 part by mass or less, even more preferably 0.05 parts by mass or more and 0.7 parts by mass or less, and particularly preferably 0.1 parts by mass or more and 0.5 parts by mass or less, based on 100 parts by mass of the resin (resin (a) or resin (b)) constituting each resin layer. Light stabilizers can be used in the same way as UV absorbers.

[0111] <Layer configuration> As described above, the laminate of the present invention has a resin layer (A) and a resin layer (B), but in one embodiment, it is preferable that the resin layer (B) is directly laminated on one side of the resin layer (A). When the laminate is heated by laser irradiation or the like, the color developer of the resin layer (B) reacts efficiently with the dye of the resin layer (A) at the interface between the resin layer (B) and the resin layer (A) and in its vicinity, causing the dye of the resin layer (A) to develop color, thus enabling marking with high color development.

[0112] However, an intermediate resin layer (C) may be provided between resin layer (A) and resin layer (B). When an intermediate resin layer (C) is provided, the dye in resin layer (A) and the color developer in resin layer (B) will appropriately migrate through the intermediate resin layer (C) when the laminate is heated by laser irradiation or the like, and will react and produce color inside the intermediate resin layer (C), or at or near the interface between the intermediate resin layer (C) and resin layer (A) or resin layer (B). Furthermore, the provision of an intermediate resin layer (C) prevents the color developer in the resin layer (B) from reacting with the dye in the resin layer (A) during laminate molding, thereby effectively preventing the dye from developing color incorrectly during laminate molding. Multiple resin layers provided in the laminate are formed integrally. Therefore, resin layer (A) and resin layer (B), which are directly laminated as described above, are bonded to each other. Furthermore, if an intermediate resin layer (C) is provided, resin layer (A) and resin layer (B) are preferably bonded via the intermediate resin layer (C).

[0113] The resin (c) used in the intermediate resin layer (C) may be a thermosetting resin or a thermoplastic resin, but it is preferably a thermoplastic resin. That is, it is preferable that all of resins (a), (b), and (c) are thermoplastic resins. By using a thermoplastic resin for the intermediate resin layer (C), mixing and extrusion molding become easier, and the moldability of the intermediate resin layer (C) is improved. Furthermore, by using thermoplastic resins for resins (a), (b), and (c), the resin layer (A), the intermediate resin layer (C), and the resin layer (B) can be easily laminated to produce a laminate. The specific thermoplastic resin used in resin (c) is the same as that used in resins (a) and (b), and the details are as described above.

[0114] Furthermore, the intermediate resin layer (C) may contain small amounts of either a dye or a developer, or both, as long as the effect of providing the intermediate resin layer (C) is appropriately exhibited. However, from the viewpoint of more appropriately preventing the dye from developing color incorrectly during laminate molding, it is preferable that neither the dye nor the developer is included. The dye content in the intermediate resin layer (C) is, for example, less than 0.5 parts by mass, preferably 0.35 parts by mass or less, more preferably 0.2 parts by mass or less, even more preferably 0.1 parts by mass or less, even more preferably 0.05 parts by mass or less, and particularly preferably 0.03 parts by mass or less, per 100 parts by mass of resin (c). Furthermore, the developer content in the intermediate resin layer (C) is, for example, less than 0.5 parts by mass, preferably 0.35 parts by mass or less, more preferably 0.2 parts by mass or less, even more preferably 0.1 parts by mass or less, even more preferably 0.05 parts by mass or less, and particularly preferably 0.03 parts by mass or less, per 100 parts by mass of resin (c). Furthermore, the intermediate resin layer (C) may appropriately contain additives other than dyes and color developers. The additives other than dyes and color developers used in resin (c) are the same as the various additives used in resins (a) and (b), and their details are as described above.

[0115] In the laminate, there may be only one resin layer (A) and one resin layer (B), but at least one of the resin layers (A) and resin layer (B) may be provided in multiple layers. For example, there may be two resin layers (B), with resin layers (B) provided on each side of resin layer (A). Alternatively, there may be two resin layers (A), with resin layers (A) provided on each side of resin layer (B).

[0116] Multiple layers of resin layers (A) and (B) may be provided, and if multiple layers of either are provided, resin layers (A) and resin layers (B) may be provided alternately, for example. In that case, the multiple resin layers (A) may have dyes that produce different colors from each other. Also, for example, if each resin layer (B) contains a photothermal converter, it is preferable that the absorption wavelength (e.g., the wavelength of the maximum value of the absorption peak) of the photothermal converter contained in each resin layer (B) be different from that of each other. If the absorption wavelength of the photothermal converter is different for each resin layer (B), it is possible to control which of the multiple resin layers (A) produces color by changing the wavelength of the laser light irradiated onto the laminate, making it possible to produce a variety of colors. Similarly, for example, if each resin layer (A) contains a photothermal converter, it is preferable that the absorption wavelength (e.g., the wavelength of the maximum value of the absorption peak) of the photothermal converter contained in each resin layer (A) be different from that of each other. Furthermore, if one or both of the resin layer (A) and resin layer (B) are provided in multiple quantities, it is preferable that adjacent resin layers (A) and resin layer (B) are directly laminated without any other layers in between, but an intermediate resin layer (C) may be provided between them as appropriate.

[0117] The thickness of the resin layer (A) is not particularly limited, but is preferably 1 μm or more, more preferably 6 μm or more, even more preferably 10 μm or more, even more preferably 20 μm or more, and particularly preferably 30 μm or more. By making the thickness of the resin layer (A) equal to or greater than the above lower limit, a laminate with sufficient strength can be made. Therefore, it can be suitably used for passports or cards. Furthermore, the thickness of the resin layer (A) is not particularly limited, but is preferably 300 μm or less, more preferably 200 μm or less, even more preferably 170 μm or less, even more preferably 150 μm or less, and particularly preferably 130 μm or less. By keeping the thickness of the resin layer (A) below the above upper limit, good color development can be achieved without making the laminate unnecessarily thick.

[0118] The thickness of the resin layer (B) is not particularly limited, but is preferably 1 μm or more, more preferably more than 6 μm, even more preferably 10 μm or more, even more preferably 20 μm or more, even more preferably 30 μm or more, and particularly preferably more than 30 μm. By making the thickness of the resin layer (B) equal to or greater than the above lower limit, a laminate with sufficient strength can be obtained. Furthermore, the thickness of the resin layer (B) is not particularly limited, but is preferably 300 μm or less, more preferably 200 μm or less, even more preferably 170 μm or less, even more preferably 150 μm or less, and particularly preferably 130 μm or less. By keeping the thickness of the resin layer (B) below the above upper limit, good color development can be achieved without making the laminate unnecessarily thick.

[0119] Furthermore, if an intermediate resin layer (C) is provided, the thickness of the intermediate resin layer (C) is not particularly limited, but is preferably 1 μm or more and 200 μm or less. By setting the thickness of the intermediate resin layer (C) within the above range, it is possible to prevent the dye contained in the resin layer (A) from developing color incorrectly during manufacturing, while allowing at least one of the dye or developer to migrate appropriately through the intermediate resin layer (C) so that it can develop color appropriately when marking. From the above viewpoint, the thickness of the intermediate resin layer (C) is more preferably 5 μm or more and 150 μm or less, even more preferably 10 μm or more and 100 μm or less, and particularly preferably 15 μm or more and 80 μm or less.

[0120] The overall thickness of the laminate is not particularly limited, but from the viewpoint of ensuring the thickness of each resin layer without making it unnecessarily thick, it is preferably 2 μm to 2000 μm, more preferably 10 μm to 1500 μm, even more preferably 30 μm to 1200 μm, even more preferably 50 μm to 1000 μm, particularly preferably 80 μm to 900 μm, and especially preferably 100 μm to 800 μm.

[0121] The size of the laminate varies depending on the application, but for example, when used for passports, the laminate area is 400 cm². 2 Preferably, it is 350cm 2 It is more preferable that the following conditions apply: 300cm 2 It is even more preferable that the following conditions apply: 250 cm 2 It is even more preferable that the following conditions apply: 200 cm 2 It is even more preferable that the following conditions apply: 150cm 2 It is particularly preferable that the following conditions are met, and more preferably, 50 cm. 2 More than 65cm 2 More preferably 80 cm 2 That's all. For example, when used in a passport, the shape is preferably a rectangle or other quadrilateral, with the length of one side preferably being 20 cm or less, more preferably 18 cm or less, even more preferably 16 cm or less, even more preferably 14 cm or less, and also preferably 8 cm or more, more preferably 10 cm or more, and even more preferably 11 cm or more. The length of the other side is preferably 15 cm or less, more preferably 13 cm or less, even more preferably 11 cm or less, even more preferably 10 cm or less, and also preferably 6 cm or more, more preferably 7 cm or more, and even more preferably 8 cm or more. By forming a laminate of such size and shape, it can be suitably used in passports, and even more so in electronic passports, particularly as data pages for these.

[0122] The area of ​​the laminate is, for example, 200 cm² when used for cards. 2 It is also preferable that it be less than 150cm 2 It is more preferable that the following conditions apply: 100 cm 2 It is even more preferable that the following is true: 80cm 2 More preferably, the following is true: 60 cm 2 It is particularly preferable that the following conditions are met, and more preferably, 20 cm. 2 More preferably 30cm 2 That's all. Furthermore, the shape is preferably a rectangle or other quadrilateral, and the length of one side is preferably 17 cm or less, more preferably 15 cm or less, even more preferably 13 cm or less, particularly preferably 11 cm or less, and preferably 6 cm or more, and more preferably 7.5 cm or more. The length of the other side is preferably 14 cm or less, more preferably 12 cm or less, even more preferably 10 cm or less, particularly preferably 8 cm or less, and also preferably 4 cm or more, and more preferably 4.5 cm or more. By creating a laminate of this size and shape, it can be suitably used as a card.

[0123] The laminate is preferably highly transparent, and its total light transmittance according to JIS K7361-1:1997 is preferably 84% or higher, more preferably 86% or higher, even more preferably 88% or higher, particularly preferably 90% or higher, and most preferably 92% or higher. By increasing the transparency of the laminate, it is possible to increase the contrast between the marked area and the other areas.

[0124] <Method for manufacturing laminates> The method for manufacturing the laminate is not particularly limited and can be manufactured by known methods, but the following describes an example in which the resins constituting each resin layer are thermoplastic resins. Specifically, first, the resins (resin(a), resin(b)) that make up each resin layer (for example, resin layer (A) and resin layer (B)) and other components (for example, at least a dye in resin layer (A), and at least a color developer in resin layer (B)) are melt-kneaded in an extruder, plast mill, etc. to obtain a resin composition for forming each resin layer. This resin composition is then made into a film, and the film-like resin layers (for example, resin layer (A) and resin layer (B)) are laminated together to form a laminate. Here, the method for making the resin composition into a film is not particularly limited, and can be press-molded or extruded, but extruded molding is preferred in terms of productivity and cost. Furthermore, by adopting such a manufacturing method, there is an advantage in that the suitability of the laminate for secondary processing such as shaping and bending is improved compared to coating methods using paints, etc.

[0125] Furthermore, the method for laminating multiple film-like resin layers (for example, resin layer (A) and resin layer (B)) is not particularly limited. Multiple pre-made film-like resin layers may be laminated by a known lamination method, or a resin composition for forming another resin layer may be melt-extruded (i.e., by an extrusion method) onto the film-like resin layers. In the lamination method, for example, multiple resin layers may be laminated by passing them between a pair of rolls while being conveyed by a roll-to-roll system, or multiple resin layers may be laminated by pressing them with a press machine or the like. The press may be a pressure press or a vacuum heat press, but a vacuum heat press is preferred. The extrusion method may also be a co-extrusion method. Specifically, a resin composition for forming each resin layer may be obtained in the same manner as described above, and the laminate may be obtained by melt co-extruding the resin composition using a feed block method or a multi-manifold method. Of the above options, it is preferable to manufacture the laminate using molten co-extrusion from the standpoint of productivity and cost. In this manufacturing method, a laminate may be obtained by directly laminating a resin layer (B) onto a resin layer (A), or a laminate having an intermediate resin layer (C) may be obtained by laminating a resin layer (A), an intermediate resin layer (C), and a resin layer (B).

[0126] When kneading each component to obtain a resin composition, the temperature is preferably above the crystalline melting temperature of the pigments and developers used, and below the thermal decomposition temperature, from the viewpoint of improving the dispersibility of the pigments and developers used. The appropriate kneading temperature varies depending on the type of resin (a) and resin (b), but specifically, for example, it is 130°C to 300°C, preferably 150°C to 270°C, and more preferably 175°C to 250°C. Furthermore, the temperature at which the obtained resin composition is formed into a film-like resin layer by extrusion molding or press molding is not particularly limited, but is, for example, 80°C to 300°C, preferably 100°C to 270°C, and more preferably 150°C to 250°C.

[0127] Furthermore, the temperature and pressure used when laminating multiple resin layers should be such that the dye incorporated into resin layer (A) does not react with the developer incorporated into resin layer (B). For example, when laminating by extrusion molding such as co-extrusion, it is best to consider the types of resin, dye, and developer used and perform co-extrusion at an appropriate temperature to obtain the laminate. Similarly, when laminating by lamination, it is best to perform heat bonding within the above temperature range, but if the pressure is too high, even within the above temperature range, the dye in resin layer (A) may react with the developer in resin layer (B) and develop color, so the pressure should be adjusted as appropriate. The temperature at which multiple resin layers (at least resin layer (A) and resin layer (B)) are laminated is not particularly limited, but it is preferably lower than the crystal melting temperature of at least one of the dye contained in resin layer (A) and the developer contained in resin layer (B), and more preferably lower than the crystal melting temperature of both the dye and the developer. It is also preferable to heat to a temperature higher than the glass transition temperature of resin (a) and resin (b). Lamination at a temperature higher than the glass transition temperature of resin layer (A) and resin layer (B), and lower than the crystal melting temperature of the dye or developer, makes it easier to properly laminate resin layer (A) and resin layer (B) while preventing color development. Furthermore, if resin (a) and resin (b) are crystalline resins, it is preferable to heat them to a temperature near the crystalline melting temperature of resin (a) and resin (b), and preferably above the crystalline melting temperature. Lamination is performed at a temperature near the crystalline melting temperature of resin layer (A) and resin layer (B), and above the crystalline melting temperature, and at a temperature lower than the crystalline melting temperature of the dye or developer, which makes it easier to properly laminate resin layer (A) and resin layer (B) while preventing color development. The temperature when laminating resin layer (A) and resin layer (B) is, for example, 95°C to 250°C, preferably 100°C to 200°C, and more preferably 120°C to 170°C.

[0128] <How to use the laminate> The laminate of the present invention can be used as a marking sheet in which marking is performed by the color development of the dye in the resin layer (A). As described above, the laminate of the present invention is preferably capable of developing color by laser irradiation, and therefore is preferably used as a laser marking sheet. The laminate of the present invention may be colored by irradiating it with laser light having a wavelength corresponding to the absorption wavelength of the photothermal converter contained in the laminate. Specifically, for example, it may be colored by irradiating it with laser light having a peak wavelength of 300 to 3500 nm, preferably 400 to 3000 nm, more preferably 500 to 2500 nm, even more preferably 550 to 2000 nm, even more preferably 600 to 1500 nm, even more preferably 620 to 1300 nm, and particularly preferably 650 to 1100 nm. By appropriately selecting the types of dyes, color developers, and photothermal converters used, it is possible to mark the laminate with a desired color. Furthermore, the laminate of the present invention can be used for purposes other than laser marking sheets, such as a thermal recording sheet that changes color upon heating, or a thermal pressure-sensitive recording sheet that changes color upon heating and pressurization.

[0129] The laminate of the present invention can be used in passports, or in various types of cards such as IC cards, magnetic cards, driver's licenses, residence cards, qualification certificates, employee IDs, student IDs, My Number cards, seal registration certificates, vehicle registration certificates, tag cards, prepaid cards, cash cards, bank cards, credit cards, SIM cards, ETC cards, identification cards, information-carrying cards, smart cards, B-CAS cards, and memory cards. In various types of cards and passports, the laminate of the present invention is used as a recording layer on which various types of information are printed. Furthermore, in passports, the laminate of the present invention is used for data pages.

[0130] The laminate is further laminated with other films, for example, and fused together by heat press molding or lamination molding to become a laminate for passports or cards (hereinafter referred to as a secondary molded body). The resulting secondary molded body is then punched out to the desired size to produce a passport data sheet, particularly an electronic passport data sheet or card. Then, by irradiating the secondary molded body, preferably the portion of the secondary molded body made up of the laminate, with laser light to perform laser marking, personal names, symbols, characters, photographs, etc., can be marked, and a passport, electronic passport, or card with printed personal information can be produced. Other films used include, for example, resin films made from polycarbonate resin or polyester resin. Other films include core sheets, resin films for forming protective layers, inlet sheets, and hinge sheets, which will be described later.

[0131] For example, the card may include a core sheet in addition to the laminate of the present invention, with the laminate of the present invention laminated on one or both sides of the core sheet. The card may also include a protective layer, and a protective layer formed from a resin film or the like may be further laminated on the surface of the laminate to protect the laminate. The core sheet is preferably a resin sheet using polycarbonate resin, polyester resin, or the like as the resin material, and it is also preferable that the sheet contains a coloring agent such as a white pigment as appropriate. The thickness of the core sheet is, for example, about 400 to 700 μm.

[0132] The passport (passport data page), especially in the case of an electronic passport, may include, in addition to the laminate described above, a hinge sheet and core sheets provided on both sides of the hinge sheet, with the laminate of the present invention laminated on the surface of the core sheets. The passport may also have a sheet, so-called inlet sheet, on which various information is stored in a storage medium such as an IC chip. The inlet sheet may be provided, for example, between the hinge sheet and the core sheet. The hinge sheet is a sheet that holds the recording layer, core sheet, inlet sheet, etc., and plays a role in securely binding the passport cover together with other visa sheets, etc. Therefore, it is preferable that the hinge sheet has strong heat-sealing properties, appropriate flexibility, and heat resistance during the heat-sealing process. The hinge sheet can be any known material, and may be a resin sheet made of thermoplastic resin or thermoplastic elastomer, or it may be made of woven fabric, knitted fabric or nonwoven fabric, or it may be a composite material of woven fabric, knitted fabric or nonwoven fabric and thermoplastic resin or thermoplastic elastomer. The core sheet in the passport is the same as described above, except that it is preferably 50 to 200 μm thick. [Examples]

[0133] Examples and comparative examples are shown below, but these do not limit the present invention in any way.

[0134] The raw materials used in the examples and comparative examples are as follows: PE: Prime Polymer's "ULTZEX2021L", LLDPE PC-1: Mitsubishi Engineering Plastics Co., Ltd. "Yupilon H-3000" (glass transition temperature: 158℃), bisphenol A type polycarbonate resin PC-2: A polycarbonate resin obtained by melt polymerization using isosorbide and 1,4-cyclohexanedimethanol as dihydroxy compounds, such that the ratio of structural units derived from isosorbide to those derived from 1,4-cyclohexanedimethanol is 50:50 (mol%) (glass transition temperature: 108°C). Leuco dye: "RED520" manufactured by Yamada Chemical Industries, Ltd., 2-methyl-6-(Np-tolyl-N-ethylamino)fluorane, thermal decomposition temperature 330℃, crystal melting temperature 169℃ Chromogenator: "TOMILAC KN" manufactured by Mitsubishi Chemical Corporation, 4-hydroxy-4'-n-propoxydiphenylsulfone, thermal decomposition temperature 290°C, crystal melting temperature 156°C Photothermal conversion agent: "YKR-3080" manufactured by Yamamoto Kasei Co., Ltd., heterocyclic porphyrazine vanadium compound, maximum absorption peak 1005.5 nm, decomposition temperature 270°C or higher.

[0135] [Example 1] Raw materials were added in the predetermined proportions as shown in Tables 1 and 2 to a Toyo Seiki Seisakusho Co., Ltd. Laboplast Mill "4C150," and the mixture was melt-kneaded at 200°C, 60 rpm, and for 5 minutes. The resulting resin composition was press-molded at 200°C to produce resin layer (A) and resin layer (B) films (A-2) and (B-1). Each film had a thickness of approximately 70 μm. The obtained films (A-2) and (B-1) were stacked and then hot-pressed at 100°C, 20 MPa for 10 seconds to produce a laminate consisting of a two-layer structure of resin layer (A) and resin layer (B).

[0136] [Examples 2-6, Comparative Examples 1 and 2] As shown in Tables 1 and 2, a laminate consisting of two layers was prepared in the same manner as in Example 1, except that the raw materials to be mixed and their proportions were changed, and the films for resin layer (A) and resin layer (B) were changed as shown in Table 3.

[0137] [Example 7] A laminate consisting of three layers was fabricated in the same manner as in Example 1, except that an intermediate resin layer (C-2) was placed between the obtained films (A-2) and (B-1) and stacked.

[0138] [Example 8] Raw materials were added in the predetermined proportions as shown in Tables 1 and 2 to a Toyo Seiki Seisakusho Co., Ltd. Laboplast Mill "4C150," and melt-kneaded at 230°C, 60 rpm, and for 5 minutes. The resulting resin composition was press-molded at 200°C using an Imoto Seisakusho Co., Ltd. heating press "IMC-18DA type" to produce resin layer (A) and resin layer (B) films (A-6) and (B-4). The thickness of each film was approximately 250 μm. The obtained films (A-6) and (B-4) were stacked and then hot-pressed at 150°C, 20 MPa for 10 seconds to produce a laminate consisting of a two-layer structure of resin layer (A) and resin layer (B).

[0139] [Example 9] Raw materials were fed into a co-rotating twin-screw extruder (φ25mm) in the predetermined proportions shown in Tables 1 and 2. The materials were melt-kneaded and extruded at 230°C and 120 rpm to produce resin layer (A) and resin layer (B) films (A-7) and (B-5). Each film had a thickness of 40 μm. The obtained films (A-7) and (B-5) were stacked and then vacuum-heat-pressed at 140°C and 100 kPa for 2 minutes using a Nisshinbo Mechatronics vacuum heat press molding machine "LAMINATOR0505S" to produce a laminate consisting of a two-layer structure of resin layer (A) and resin layer (B). No color development was observed in the laminate after press molding.

[0140] [Example 10] As shown in Tables 1 and 2, a laminate consisting of two layers was prepared in the same manner as in Example 9, except that the raw materials to be mixed and their proportions were changed, and the films for resin layer (A) and resin layer (B) were changed as shown in Table 3. No color development was observed in the laminate after press molding.

[0141] [Comparative Examples 3-6] As shown in Tables 1 and 2, films for resin layer (A) or resin layer (B) were prepared by changing the raw materials to be mixed and their proportions.

[0142] [Evaluation Method] (Color development during resin layer molding) In each example and comparative example, the obtained resin layer (A) and the film for resin layer (B) were visually observed and evaluated according to the following evaluation criteria. A: None of the films produced any color. B: One of the films shows color.

[0143] (Secondary heating color development) The laminates obtained by press molding were visually inspected, and their color development was checked after press molding at 100°C or 150°C and 20 MPa for 10 seconds. The following evaluation criteria were used to assess the results. A: Coloration occurs in the laminate after press molding. B: No color development in the laminate after press molding.

[0144] (Laser color development) Using a KEYENCE MD-U1000C 3-Axis UV laser marker, laser printing was performed on a 10mm x 10mm square under the following conditions: wavelength 355nm, power 0.5W, scanning speed 1000mm / s, frequency 40kHz, hunting pitch 40μm, scanning direction crossover (0° / 90°), and heat energy 2.64J / pcs. The color development after laser printing was confirmed and evaluated according to the following evaluation criteria. A: Color appears in the laser-irradiated area after laser printing. B: No color development in the laser-irradiated area after laser printing.

[0145] [Table 1]

[0146] [Table 2]

[0147] [Table 3]

[0148] [Table 4]

[0149] In Examples 1 to 8 described above, in laminates consisting of a two-layer structure of resin layer (A) and resin layer (B), or a three-layer structure of resin layer (A), an intermediate resin layer (C), and resin layer (B), color development was confirmed by press molding by including predetermined amounts of dye in resin layer (A) and a color developer in resin layer (B). The press molding in Examples 1 to 8 was performed under heating and high pressure, and it was confirmed whether or not color development was possible by simulating laser irradiation. In each example, it is expected that the desired color will be developed by laser irradiation as well, for example by including a photothermal converter in the laminate. Furthermore, in each example, by not including more than the specified amount of color developer and dye in resin layer (A) and resin layer (B), no color development occurred in the films for resin layer (A) and resin layer (B), preventing the dye and color developer from reacting and developing color due to heating during the molding of each resin layer. Example 8 had a higher content of dye and developer than the other examples. Although the laminate was slightly harder and less easy to handle compared to the other examples, it was still at a level that did not pose a problem for practical use. Furthermore, while sufficient transparency was ensured, a slight yellowish tint was observed compared to the other examples, but the color was also at a level that did not pose a problem for practical use. In contrast, in Comparative Examples 1 and 2, although two resin layers were provided, resin layer (A) did not contain a dye, or resin layer (B) did not contain a color developer, so color development by press molding could not be confirmed. Therefore, it was expected that no color would develop even with laser irradiation, and it was not possible to provide a laminate that would develop color appropriately with laser irradiation.

[0150] Furthermore, in Examples 9 and 10, in laminates having resin layer (A) and resin layer (B), color development by laser printing was confirmed by including predetermined amounts of dye in resin layer (A) and a color developer in resin layer (B). Moreover, in Examples 9 and 10, no color development was confirmed during the film manufacturing for resin layer (A) and resin layer (B), or during the lamination of each layer, thus demonstrating that the laminate of the present invention can be manufactured without color development. On the other hand, in Comparative Examples 3 to 6, the resin sheets had a single-layer structure with only one of either resin layer (A) or resin layer (B), so color development by laser printing could not be confirmed.

Claims

1. A laminate having at least two layers, resin layer (A) and resin layer (B), The resin layer (A) contains resin (a) and a dye, wherein the dye content in the resin layer (A) is less than 50 parts by mass per 100 parts by mass of resin (a), and the developer content in the resin layer (A) is less than 0.5 parts by mass per 100 parts by mass of resin (a). The resin layer (B) comprises a resin (b) and a color developer, wherein the content of the color developer in the resin layer (B) is less than 50 parts by mass per 100 parts by mass of resin (b), and the content of the dye in the resin layer (B) is less than 0.5 parts by mass per 100 parts by mass of resin (b). A laminate in which the resin layer (B) is directly laminated on at least one surface of the resin layer (A).

2. The laminate according to claim 1, wherein the thickness of the resin layer (A) is greater than 6 μm.

3. The laminate according to claim 1 or 2, wherein the thickness of the resin layer (B) is greater than 6 μm.

4. The laminate according to any one of claims 1 to 3, wherein the content of the dye in the resin layer (A) is 30 parts by mass or less per 100 parts by mass of the resin (a).

5. The laminate according to any one of claims 1 to 4, wherein the content of the color developer in the resin layer (B) is 30 parts by mass or less per 100 parts by mass of the resin (b).

6. The laminate according to any one of claims 1 to 5, wherein the thermal decomposition temperature of the dye is 200°C or higher.

7. The laminate according to any one of claims 1 to 6, wherein the thermal decomposition temperature of the color developer is 200°C or higher.

8. The laminate according to any one of claims 1 to 7, wherein the crystal melting temperature of the dye is 100°C or higher.

9. The laminate according to any one of claims 1 to 8, wherein the crystal melting temperature of the dye is 300°C or less.

10. The laminate according to any one of claims 1 to 9, wherein the crystal melting temperature of the color developer is 100°C or higher.

11. The laminate according to any one of claims 1 to 10, wherein the crystal melting temperature of the color developer is 300°C or less.

12. The laminate according to any one of claims 1 to 11, wherein both resin (a) and resin (b) are thermoplastic resins.

13. The laminate according to any one of claims 1 to 12, wherein the resin (a) is at least one selected from the group consisting of polycarbonate resin, polyester resin, polyolefin resin, and acrylic resin.

14. The laminate according to any one of claims 1 to 13, wherein the resin (b) is at least one selected from the group consisting of polycarbonate resin, polyester resin, polyolefin resin, and acrylic resin.

15. The laminate according to any one of claims 1 to 14, wherein the content (A1) is the amount of dye per 100 parts by mass of resin (a) in the resin layer (A), and the content (B1) is the amount of dye per 100 parts by mass of resin (b) in the resin layer (B), and the ratio (B1 / A1) of content (B1) to content (A1) is 0 or more and 0.5 or less.

16. The laminate according to any one of claims 1 to 15, wherein the content (A2) is the amount of color developer per 100 parts by mass of resin (a) in resin layer (A), and the content (B2) is the amount of color developer per 100 parts by mass of resin (b) in resin layer (B), and the ratio (A2 / B2) of content (A2) to content (B2) is 0 or more and 0.5 or less.

17. The laminate according to any one of claims 1 to 16, wherein the content (A1) is the amount of dye per 100 parts by mass of resin (a) in the resin layer (A), and the content (B2) is the amount of color developer per 100 parts by mass of resin (b) in the resin layer (B), and the ratio (A1 / B2) of content (A1) to content (B2) is 0.01 or more and 3 or less.

18. Area is 400 cm² ２ The laminate according to any one of claims 1 to 17, which is as follows:

19. Area is 200 cm² ２ The laminate according to any one of claims 1 to 18, which is as follows:

20. A laminate according to any one of claims 1 to 19, which is capable of producing color by laser irradiation.

21. A laminate according to any one of claims 1 to 20, for use in a card.

22. A laminate according to any one of claims 1 to 20, for use in a passport.

23. A card comprising a laminate according to any one of claims 1 to 21.

24. A passport comprising a laminate according to any one of claims 1 to 20 and 22.

25. A method for manufacturing a laminate having at least two layers, a resin layer (A) and a resin layer (B), The resin layer (A) contains resin (a) and a dye, wherein the dye content in the resin layer (A) is less than 50 parts by mass per 100 parts by mass of resin (a), and the developer content in the resin layer (A) is less than 0.5 parts by mass per 100 parts by mass of resin (a). The resin layer (B) comprises a resin (b) and a color developer, wherein the content of the color developer in the resin layer (B) is less than 50 parts by mass per 100 parts by mass of resin (b), and the content of the dye in the resin layer (B) is less than 0.5 parts by mass per 100 parts by mass of resin (b). A method for manufacturing a laminate, comprising the steps of melting and kneading at least the resin (a) and the dye, or melting and kneading at least the resin (b) and the color developer.

26. Furthermore, the method for manufacturing a laminate according to claim 25, further comprising the step of laminating at least the resin layer (A) and the resin layer (B).

27. The method for manufacturing a laminate according to claim 26, wherein at least the step of laminating the resin layer (A) and the resin layer (B) is performed by an extrusion method or a lamination method.

28. A method for producing a laminate, comprising: preparing a resin composition (A) by melt-kneading at least a resin (a) and a dye; preparing a resin composition (B) by melt-kneading at least a resin (b) and a color developer; and producing a laminate by laminating a resin layer (A) formed from at least a resin composition (A) and a resin layer (B) formed from at least a resin composition (B) by an extrusion or lamination method.

29. A laser marking method for laser marking a laminate produced by the method for manufacturing a laminate according to claim 28 by laser irradiation.

30. A method for manufacturing a card comprising a laminate according to any one of claims 1 to 21, A method for manufacturing a card, comprising at least the steps of laminating and fusing the laminate with another film, and laser marking by laser irradiation.

31. A method for manufacturing a passport comprising a laminate according to any one of claims 1 to 20 and 22, A method for manufacturing a passport, comprising at least the steps of laminating and fusing the laminate with another film, and laser marking by laser irradiation.

32. A method for using a laminate according to any one of claims 1 to 22 by laser marking it for use in a card or passport.

33. Use of a laminate according to any one of claims 1 to 22 on a card or passport, wherein laser marking is applied to the laminate.

Images