Luminescent material, paint, printed material, and resin molded article

Abstract

To provide a luminescent material suitable for authenticity discrimination techniques.SOLUTION: A luminescent material comprises three or more rare-earth element ions and a linker ligand forming coordinate bonds with two to four rare-earth element ions, the three or more rare-earth element ions and the linker ligand forming a rare-earth complex. The three or more rare-earth element ions include at least two rare-earth element ions A selected from the group consisting of Yb, Nd, Sm, Eu, Tb, Dy, Ce, Pr, Ho, Er, and Tm, and at least one rare-earth element ion B selected from the group consisting of Y, La, Gd, and Lu. The linker ligand has a linker group, and a substituent bound to the linker group and including a coordination-bond-forming functional group that forms a coordinate bond with a rare-earth element ion, or has a linker group including a coordination-bond-forming functional group that forms a coordinate bond with a rare-earth element ion.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a light-emitting material, a paint, a printed matter, and a resin molded article. [Background technology]

[0002] In recent years, the distribution of counterfeit goods has become a social problem, and the importance of authenticating not only high-value items such as banknotes, brand-name goods, and tickets, but also industrial products such as automobile parts, semiconductor parts, and pharmaceuticals is increasing. Counterfeiting of these products not only causes economic losses, but also leads to a decline in safety and reliability, and may threaten the health and lives of consumers, so there is an urgent need to develop effective authentication technology.

[0003] Authentication methods include those that utilize physical and chemical properties, and technologies related to paints in particular have been widely researched. Some paints emit specific light in response to ultraviolet or infrared light, and applying these to products makes it possible to distinguish them from counterfeits. For example, Patent Document 1 describes an authenticity determination technology that uses an infrared fluorescent emitter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-241750 Summary of the Invention [Problem to be solved by the invention]

[0005] One aspect of the present invention relates to a luminescent material useful in authentication techniques. [Means for solving the problem]

[0006] One aspect of the present invention relates to, for example, the following [1] to

[12] . [1] A compound comprising three or more types of rare earth element ions and linker ligands that form coordinate bonds with two to four of the rare earth element ions; a light-emitting material, wherein the three or more kinds of rare earth element ions and the linker ligand form a rare earth complex; The three or more kinds of rare earth element ions are At least two rare earth element ions A selected from the group consisting of Yb(III), Nd(III), Sm(III), Eu(III), Tb(III), Dy(III), Ce(III), Pr(III), Ho(III), Er(III), and Tm(III); At least one rare earth element ion B selected from the group consisting of Y(III), La(III), Gd(III), and Lu(III); Including, The linker ligand is a linker group and a substituent bonded to the linker group, the substituent comprising a coordinating functional group that forms a coordinate bond with a rare earth element ion; or a linker group containing a coordinate-bonding functional group that forms a coordinate bond with a rare earth element ion; Luminescent material. [2] The light-emitting material according to [1], wherein the linker group is a group containing two or more aromatic rings bonded to each other via a covalent bond, or a fused polycyclic aromatic group. [3] The light-emitting material according to [1] or [2], wherein the coordination functional group is a phosphine oxide group. [4] The light-emitting material according to any one of [1] to [3], further comprising a non-linker ligand that forms a coordinate bond with one rare earth element ion. [5] The light-emitting material according to [4], wherein the non-linker ligand comprises at least one of a diketonato ligand represented by the following general formula (10) and a carboxylate ligand represented by the following general formula (20): [ka] [In formula (10), R 11 and R 12each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted trialkylsilyl group, R 11 or R 12 at least one of is a substituted or unsubstituted alkyl group having 2 or more carbon atoms, a substituted or unsubstituted trialkylsilyl group, or a substituted or unsubstituted aromatic group, R 13 represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic group, R 13 R 11 or R 12 may be bonded to form a cyclic group.] [ka] [In formula (20), R 21 , R 22 , R 23 , R 24 , and R 25 each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted trialkylsilyl group, or a substituted or unsubstituted aromatic group, R 21 , R 22 , R 23 , R 24 , and R 25 At least two of the groups are a halogen atom, a substituted or unsubstituted alkyl group having two or more carbon atoms, a substituted or unsubstituted trialkylsilyl group, or a substituted or unsubstituted aromatic group. [6] The light-emitting material according to any one of [1] to [5], wherein some of the linker ligands in the light-emitting material form rare-earth complexes with two or more rare-earth element ions B. [7] The light-emitting material according to [6], which contains a mixed crystal containing three or more of the rare earth complexes. [8] The luminescent material according to any one of [1] to [7], wherein the content of the rare earth element ion A is 30 mass % or less based on the total mass of the rare earth element ion A and the rare earth element ion B. [9] The at least two kinds of rare earth element ions A include a first rare earth element ion A1 and a second rare earth element ion A2; The light-emitting material according to any one of [1] to [8], wherein the content of the first rare earth element ion A1 is different from the content of the second rare earth element ion A2.

[10] A coating material comprising the luminescent material according to any one of [1] to [9] and a dispersion medium in which the luminescent material is dispersed.

[11] A printed matter comprising the luminescent material according to any one of [1] to [9] and a substrate to which the luminescent material is attached.

[12] A resin molded product, which is a cured product of a mixture containing the light-emitting material according to any one of [1] to [9] and a resin. [Effects of the Invention]

[0007] According to one aspect of the present invention, there is provided a luminescent material useful for authentication techniques. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic diagram illustrating an example of a light-emitting material. DETAILED DESCRIPTION OF THE INVENTION

[0009] The invention is not limited to the examples described below.

[0010] An example of a light-emitting material includes three or more types of rare earth element ions and a linker ligand that forms coordinate bonds with two to four of the rare earth element ions, and the three or more types of rare earth element ions and the linker ligand form a rare earth complex in the light-emitting material.

[0011] The three or more types of rare earth element ions include at least two types of rare earth element ions A selected from the group consisting of Yb(III), Nd(III), Sm(III), Eu(III), Tb(III), Dy(III), Ce(III), Pr(III), Ho(III), Er(III), and Tm(III), and at least one type of rare earth element ion B selected from the group consisting of Y(III), La(III), Gd(III), and Lu(III).

[0012] The rare earth ions A can form a luminescent complex. Hereinafter, among the two or more types of rare earth ions A, one type of rare earth ion A is referred to as the first rare earth ion A1, and the other type of rare earth ion A is referred to as the second rare earth ion A2. That is, the at least two types of rare earth ions A include the first rare earth ion A1 and the second rare earth ion A2. The rare earth ions B can form a non-luminescent complex. The three or more types of rare earth ions may include three or more types of rare earth ions A and / or two or more types of rare earth ions B, or may include rare earth ions other than the rare earth ions A and B.

[0013] FIG. 1 is a schematic diagram showing an example of a light-emitting material. In FIG. 1, dashed lines indicate energy transfer. Light-emitting material 1 shown in FIG. 1 includes a non-light-emitting complex BB, which is a rare earth complex formed by two rare earth ions B and a linker ligand; a light-emitting complex A1B, which is a rare earth complex formed by one first rare earth ion A1, one rare earth ion B, and a linker ligand; and a light-emitting complex A2B, which is a rare earth complex formed by one second rare earth ion A2, one rare earth ion B, and a linker ligand. Light-emitting material 1 may be a mixed crystal containing complex BB, complex A1B, and complex A2B. The light-emitting material may also include a light-emitting complex AA, which is a rare earth complex formed by two rare earth ions A and a linker ligand. Complex AA may be at least one selected from the group consisting of complex A1A1, complex A2A2, and complex A1A2.

[0014] In one complex BB, the excited ligand transitions from the S1 level to the T1 level due to intersystem crossing upon irradiation with light. Energy transfer occurs between the T1 levels of multiple complexes BB, and complexes A1B and A2B, which receive the energy, emit light. This relatively slow energy transfer results in delayed luminescence, and because the type of rare earth element ion A is different, complexes A1B and A2B emit light of different colors. Furthermore, because the time required for energy transfer to complex A1B differs from the time required for energy transfer to complex A2B, the difference in energy transfer time results in luminescence whose color changes over time (timechromic luminescence). This timechromic luminescence changes the emitted color over time, allowing for advanced authentication based on the change in emitted color.

[0015] The combination of rare earth element ions A can be appropriately determined depending on the application of the luminescent material. The combination of rare earth element ions A may be one that allows for visual detection of time-chromic luminescence by humans, or one that is difficult to detect visually by humans. If the combination of rare earth element ions A allows for difficult visual detection of time-chromic luminescence by humans, the time-chromic luminescence may be detected using a measuring device or the like. Examples of combinations of rare earth element ions A include a combination of Eu(III) and Tb(III), a combination of Sm(III) and Dy(III), a combination of Yb(III) and Nd(III), and a combination of Er(III) and Tm(III).

[0016] The linker ligand has either (1) a linker group and a substituent bonded to the linker group, the substituent containing a coordinating functional group that forms a coordinate bond with a rare earth element ion (the linker group and the coordinating functional group are each independently present), or (2) a linker group containing a coordinating functional group that forms a coordinate bond with a rare earth element ion (the coordinating functional group is included in the chemical structure of the linker group (e.g., an aromatic heterocycle)).

[0017] When the linker ligand has a linker group and a substituent bonded to the linker group and containing a coordinating functional group that forms a coordinate bond with a rare earth element ion, the linker ligand may be, for example, a ligand compound represented by the following general formula (1): [ka] In formula (1), X represents a divalent to tetravalent linker group, Z represents a group containing a coordinate bond functional group, multiple Zs in the same molecule may be the same or different, and p is an integer of 1 to 3.

[0018] X in formula (1) may be an arylene group (e.g., a phenylene group), an alkylene group having 1 to 9 carbon atoms, an oxy group, a sulfide group, an amino group, an amido group, a sulfonyl group, an aryltriyl group, or an alkanetriyl group having 1 to 9 carbon atoms. The arylene group and the aryltriyl group may be a group containing two or more aromatic rings bonded to each other via a covalent bond, or may be a fused polycyclic aromatic group. The linker groups exemplified above may have a substituent or may be unsubstituted.

[0019] The linker group may be a group containing two or more aromatic rings or a fused polycyclic aromatic group, from the viewpoint of extending the light-emitting duration of the light-emitting material. Examples of the group containing two or more aromatic rings or the fused polycyclic aromatic group as the linker group include groups in which 2 to 4 hydrogen atoms of the compounds represented by the following formulae are substituted with Z. The following compounds may have a substituent or may be unsubstituted. In these formulae, R represents a hydrogen atom, an alkyl group, or an aromatic group, and R 1 and R 2 each independently represents a hydrogen atom, an alkyl group or an aromatic group. [ka]

[0020] At least one Z in formula (1) may be a substituent containing a phosphine oxide group as a coordinating functional group, and in that case, the linker ligand may be a phosphine oxide compound represented by the following formula (2): 1 and Ar 2 each independently represents a substituted or unsubstituted cycloalkyl group (for example, a cyclohexyl group) or a substituted or unsubstituted monovalent aromatic group, and X, Z, and p are as defined above. [ka]

[0021] The phosphine oxide compound represented by formula (2) can be synthesized, for example, by using a halogenated cycloalkyl compound or a halogenated aromatic compound as a starting material and combining ordinary reactions known to those skilled in the art.

[0022] Ar in formula (2) 1 and Ar 2 may be an unsubstituted cycloalkyl group from the viewpoint of extending the light-emitting duration of the light-emitting material. Furthermore, the linker ligand may be one represented by the following formula (2A) from the viewpoint of extending the light-emitting duration of the light-emitting material. [ka]

[0023] In one embodiment, the light-emitting material comprises two or more rare earth ions and a linker ligand that forms coordinate bonds with two to four of the rare earth ions, the two or more rare earth ions and the linker ligand forming a rare earth complex, the two or more rare earth ions comprising at least one rare earth ion A selected from the group consisting of Yb(III), Nd(III), Sm(III), Eu(III), Tb(III), Dy(III), Ce(III), Pr(III), Ho(III), Er(III), and Tm(III), and at least one rare earth ion B selected from the group consisting of Y(III), La(III), Gd(III), and Lu(III), and the linker ligand is represented by Formula (2A). That is, another aspect of the present invention relates to such a light-emitting material. Such a luminescent material can achieve delayed luminescence and can be used for sensing oxygen concentration, authenticity determination, and the like.

[0024] When the linker ligand has a linker group containing a coordinate-bonding functional group that forms a coordinate bond with a rare earth element ion, the linker ligand may be, for example, a ligand compound represented by the following general formula (3). [ka] In formula (3), A 1 represents a group of atoms forming a substituted or unsubstituted aromatic group together with the nitrogen atom forming a coordinate bond with the rare earth element ion, and Y represents A 1 and q is 1 or 2.

[0025] Specific examples of the ligand compound (bidentate ligand) of formula (3) when q is 1 and Y is a direct bond include the following compounds: These compounds may have a substituent. [ka]

[0026] Specific examples of the ligand compound (bidentate ligand) of formula (3) when q is 1 and Y is a divalent linking group include the following compounds. In the formula, Ar represents an aryl group. These compounds may have a substituent. [ka]

[0027] Specific examples of the ligand compound (tridentate ligand) represented by formula (3) when q is 2 and Y is a trivalent linking group include the following compounds. These compounds may have a substituent. [ka]

[0028] A in equation (3) 1 and the aromatic group formed by the nitrogen atom may contain two or more nitrogen atoms that form coordinate bonds with the rare earth element ion. 1 Specific examples of the ligand compound (tridentate ligand) represented by formula (3) when the aromatic group formed by the and nitrogen atoms contains two nitrogen atoms include the following compounds. This compound may have a substituent. [ka]

[0029] The light-emitting material may further include a non-linker ligand that forms a coordinate bond with one rare earth element ion. The non-linker ligand may have a relatively bulky substituent. The introduction of a non-linker ligand having a relatively bulky substituent tends to cause the linker ligands to be separated from each other in the light-emitting material (or mixed crystal). The larger the distance between the linker ligands, the slower the energy transfer between the linker ligands. As a result, the light-emitting time of the light-emitting material can be extended.

[0030] Examples of non-linker ligands having relatively bulky substituents include diketonato ligands represented by the following general formula (10) and carboxylate ligands represented by the following general formula (20). The light-emitting material may contain at least one of these ligands. [ka] In formula (10), R 11 and R 12 each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted trialkylsilyl group; R 11 or R 12 at least one of R is a substituted or unsubstituted alkyl group having 2 or more carbon atoms, a substituted or unsubstituted trialkylsilyl group, or a substituted or unsubstituted aromatic group; 13 represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic group. 13 R 11 or R 12 The substituted or unsubstituted alkyl group having two or more carbon atoms, the substituted or unsubstituted trialkylsilyl group, and the substituted or unsubstituted aromatic group are relatively bulky substituents. [ka] In formula (20), R 21 , R 22 , R 23 , R 24 , and R 25 each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted trialkylsilyl group, or a substituted or unsubstituted aromatic group; R 21 , R 22 , R 23 , R 24 , and R 25 At least two of R are halogen atoms, substituted or unsubstituted alkyl groups having two or more carbon atoms, substituted or unsubstituted trialkylsilyl groups, or substituted or unsubstituted aromatic groups.21 , R 22 , R 23 , R 24 , and R 25 The phenyl group to which is attached is a relatively bulky substituent.

[0031] When the non-linker ligand is a diketonato ligand represented by formula (10), R 11 or R 12 At least one of R may be a substituted or unsubstituted alkyl group having two or more carbon atoms, a substituted or unsubstituted trialkylsilyl group, a thiophene group, a furan group, a phenyl group, a naphthyl group, or a phenanthryl group. 11 or R 12 At least one of the groups may be a substituted or unsubstituted alkyl group having two or more carbon atoms, or a substituted or unsubstituted trialkylsilyl group. Examples of the substituted alkyl group include a perfluoroalkyl group.

[0032] Specific examples of diketone compounds that form diketonato ligands include 2,2,6,6-tetramethylheptane-3,5-dione (tmh), acetylacetone (acac), 1,1,1-trifluoroacetone (TFA), and 1,1,5,5,5-hexafluoroacetylacetone (HFA). Among these, 2,2,6,6-tetramethylheptane-3,5-dione (tmh) is particularly preferred from the viewpoint of luminous brightness, etc.

[0033] When the non-linker ligand is a carboxylate ligand represented by formula (20), R 21 , R 22 , R 23 , R 24 , and R 25 Two or more of R may be a halogen atom, a substituted or unsubstituted alkyl group having two or more carbon atoms, a substituted or unsubstituted trialkylsilyl group, a thiophene group, a furan group, a phenyl group, a naphthyl group, or a phenanthryl group. 21 , R 22 , R 23 , R24 , and R 25 At least two of these may be halogen atoms, substituted or unsubstituted alkyl groups having two or more carbon atoms, or substituted or unsubstituted trialkylsilyl groups. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. Examples of substituted alkyl groups include perfluoroalkyl groups.

[0034] When the linker ligand has a phosphine oxide group and the non-linker ligand is a diketonato ligand, the rare earth complex may have, for example, one linker ligand having a phosphine oxide group coordinated to the rare earth element ion Ln and three diketonato ligands coordinated to the rare earth element ion Ln, as represented by the following general formula (30): 11 , R 12 , R 13 , Ar 1 , Ar 2 , X, and Z have the same meanings as above. [ka]

[0035] When the linker ligand has a phosphine oxide group and the non-linker ligand is a diketonato ligand, the rare earth complex may form a coordination polymer in which two linker ligands having phosphine oxide groups are coordinated to a rare earth element ion Ln, and two diketonato ligands are coordinated to a rare earth element ion Ln, and the rare earth element ions Ln are linked together via the rare earth element ion Ln, as represented by the following general formula (40): 11 , R 12 , R 13 , Ar 1 , Ar 2 , X, and Z have the same meanings as above. [ka]

[0036] The rare earth complex can be synthesized, for example, by a method including the steps of: reacting a rare earth compound as a raw material with a diketone compound that derives a diketonato ligand of formula (10) or a carboxylate compound that derives a carboxylate ligand of formula (20) to produce an intermediate complex containing a rare earth element ion; and reacting the intermediate complex with a linker ligand of formula (1) to produce the target rare earth complex. These reactions can be carried out by stirring in an appropriate solvent, optionally in the presence of a catalyst. Examples of solvents that can be used include methanol, dichloromethane, and mixtures thereof.

[0037] Some of the linker ligands in the light-emitting material according to one embodiment may form a complex BB with two or more rare earth element ions B. The complex BB may be, for example, a rare earth complex represented by the following formula (50): Ln B indicates the rare earth element ion B, and R 11 , R 12 , R 13 , Ar 1 , Ar 2 , and X have the same meanings as above. [ka]

[0038] A part of the linker ligands in the light-emitting material may form a complex A1B with the first rare earth element ion A1 and the rare earth element ion B. The complex A1B may be, for example, a rare earth complex represented by the following formula (60). Ln in formula (60) A1 represents the first rare earth element ion A1, and R 11 , R 12 , R 13 , Ar 1 , Ar 2 , Ln B and X have the same meanings as above. [ka]

[0039] A part of the linker ligands in the light-emitting material may form a complex A2B with the second rare earth element ion A2 and the rare earth element ion B. The complex A2B may be, for example, a rare earth complex represented by the following formula (70). Ln in formula (70) A2 denotes the second rare earth element ion A2, and R 11 , R 12 , R 13 , Ar 1 , Ar 2 , Ln B and X have the same meanings as above. The second rare earth element ion A2 is a rare earth element ion different from the first rare earth element ion A1. [ka]

[0040] Some of the linker ligands in the light-emitting material may form a complex AA with two or more rare earth element ions A. The two or more rare earth element ions A may be a first rare earth element ion A1 or a second rare earth element ion A2. The complex AA may be, for example, a rare earth complex represented by the following formula (80). Ln in formula (80) A represents the first rare earth element ion A1 or the second rare earth element ion A2, and R 11 , R 12 , R 13 , Ar 1 , Ar 2 and X have the same meanings as above. [ka]

[0041] The luminescent material may include a mixed crystal containing three or more rare earth complexes. For example, the luminescent material may include a mixed crystal containing complexes A1B, A2B, and BB. According to the findings of the present inventors, when the luminescent material includes a mixed crystal containing complexes A1B, A2B, and BB, delayed luminescence based on slow energy transfer between the rare earth complexes in the mixed crystal can be realized, and authenticity can be determined based on the color change of the chronochromic luminescence. This phenomenon will be described in detail in the Examples below.

[0042] The content of rare earth element ion A in the mixed crystal may be 30% by mass or less, based on the total mass of rare earth element ion A and rare earth element ion B. By containing rare earth element ion A, which is a luminescent rare earth, in a small amount compared to other rare earth element ions, delayed luminescence based on slow energy transfer between rare earth complexes can be more effectively achieved. The content of rare earth element ion A in the mixed crystal may be 20% by mass or less, 10% by mass or less, 3% by mass or less, 1.5% by mass or less, or 1% by mass or less, based on the total mass of rare earth element ion A and rare earth element ion B, or may be 0.01% by mass or more, or 0.05% by mass or more.

[0043] The content of the first rare earth ion A1 may be the same as the content of the second rare earth ion A2, or may be different from the content of the second rare earth ion A2 in order to make the timechromic luminescence easier to detect. The content of the first rare earth ion A1 may be more than 50 mass%, 55 mass% or more, 60 mass% or more, or 65 mass% or more based on the total mass of the first rare earth ion A1 and the second rare earth ion A2 in order to make the timechromic luminescence easier to detect, and may be 90 mass% or less, 85 mass% or less, 80 mass% or less, 75 mass% or less, or 70 mass% or less in order to extend the luminescence duration.

[0044] Another aspect of the present invention is a coating material containing the above-described luminescent material and a dispersion medium in which the luminescent material is dispersed. Examples of the dispersion medium include methanol, ethanol, water, acetone, hexane, chloroform, dichloromethane, diethyl ether, ethyl acetate, benzene, toluene, and combinations thereof. The coating liquid may contain styrene, acrylic acid, methacrylic acid, an acrylic acid derivative, a methacrylic acid derivative (e.g., methyl methacrylate, ethyl methacrylate), or a polymer (e.g., polystyrene, polymethyl methacrylate).

[0045] Another aspect of the present invention is a printed matter comprising the above-described luminescent material and a substrate to which the luminescent material is attached. Examples of materials for the substrate include paper; resins such as PET, acrylic, polyethylene, polypropylene, and nylon; glass; and metals such as iron, copper, and aluminum.

[0046] Another aspect of the present invention is a resin molded article that is a cured product of a mixture containing the above-mentioned light-emitting material and a resin. The resin may be, for example, a thermosetting resin, more specifically, an epoxy resin, a phenolic resin, an unsaturated imide resin, a cyanate resin, an isocyanate resin, a benzoxazine resin, an oxetane resin, an amino resin, an unsaturated polyester resin, an allyl resin, a dicyclopentadiene resin, a silicone resin, a triazine resin, or a melamine resin. The mixture may contain a curing agent. [Example]

[0047] The present invention is not limited to the following examples.

[0048] 1. Mixed crystal synthesis Example 1 [(EU 0.0033 Tb 0.0034 Lu 1.9933 Synthesis of )(tmh)6dcph] dcph (50.7 mg, 0.084 mmol), Eu(tmh)3, Tb(tmh)3, and Lu(tmh)3 were dissolved in methanol, and the solution was heated to reflux at 70 °C and stirred for 6 hours. The weights of Eu(tmh)3, Tb(tmh)3, and Lu(tmh)3 were 0.82 mg (0.0012 mmol), 120.9 mg (0.17 mmol), and 120.9 mg (0.17 mmol). The solution was filtered and recrystallized in methanol to give (Eu 0.0033 Tb 0.0034 Lu 1.9933 )(tmh)6dcph (yield 63%, yield 107.8 mg) was obtained. ICP-AES:Eu / (Eu+Tb+Lu)=0.17%, Tb / (Eu+Tb+Lu)=0.17% Elemental analysis result: Elemental analysis calcd. (%) for C 104 H 166 O 14 P2Eu 0.0033 Tb 0.0034 Lu 1.9933 ,C60.87, H 8.15; found: C 60.83, H 8.19. [ka]

[0049] Example 2 [(EU 0.0039 Tb 0.0064 Lu 1.9897 Synthesis of )(tmh)6dcph] dcph (50.2 mg, 0.083 mmol), Eu(tmh)3, Tb(tmh)3, and Lu(tmh)3 were dissolved in methanol, and the solution was heated to reflux at 70 °C and stirred for 6 hours. The weights of Eu(tmh)3, Tb(tmh)3, and Lu(tmh)3 were 0.81 mg (0.0012 mmol), 0.51 mg (0.00072 mmol), and 119.49 mg (0.16 mmol). The solution was filtered and recrystallized in methanol to give (Eu 0.0039 Tb 0.0064 Lu 1.9897)(tmh)6dcph (yield 49%, yield 83.7 mg) was obtained. ICP-AES:Eu / (Eu+Tb+Lu)=0.19%, Tb / (Eu+Tb+Lu)=0.32% Elemental analysis result: Elemental analysis calcd. (%) for C 104 H 166 O 14 P2Eu 0.0039 Tb 0.0064 Lu 1.9897 ,C60.87, H 8.15; found: C 60.82, H 8.18.

[0050] Example 3 [(EU 0.0077 Tb 0.0045 Lu 1.9878 Synthesis of )(tmh)6dcph] dcph (50.0 mg, 0.083 mmol), Eu(tmh)3, Tb(tmh)3, and Lu(tmh)3 were dissolved in methanol, and the solution was heated to reflux at 70 °C and stirred for 6 hours. The weights of Eu(tmh)3, Tb(tmh)3, and Lu(tmh)3 were 0.93 mg (0.0013 mmol), 0.23 mg (0.00033 mmol), and 118.91 mg (0.16 mmol). The solution was filtered and recrystallized in methanol to give (Eu 0.0077 Tb 0.0045 Lu 1.9878 )(tmh)6dcph (yield 47%, yield 81 mg) was obtained. ICP-AES:Eu / (Eu+Tb+Lu)=0.39%, Tb / (Eu+Tb+Lu)=0.22% Elemental analysis result: Elemental analysis calcd. (%) for C 104 H 166 O 14 P2Eu 0.0077 Tb 0.0045 Lu 1.9878 ,C60.87, H 8.15; found: C 60.80, H 8.17.

[0051] Example 4 [(EU 0.0097 Tb 0.0062 Lu 1.9841 Synthesis of )(tmh)6dcph] dcph (50.3 mg, 0.083 mmol), Eu(tmh)3, Tb(tmh)3, and Lu(tmh)3 were dissolved in methanol, and the solution was heated to reflux at 70 °C and stirred for 6 hours. The weights of Eu(tmh)3, Tb(tmh)3, and Lu(tmh)3 were 0.99 mg (0.0014 mmol), 0.18 mg (0.00025 mmol), and 119.78 mg (0.17 mmol). The solution was filtered and recrystallized in methanol to give (Eu 0.0097 Tb 0.0062 Lu 1.9841 )(tmh)6dcph (yield 29%, yield 48.8 mg) was obtained. ICP-AES:Eu / (Eu+Tb+Lu)=0.49%, Tb / (Eu+Tb+Lu)=0.31% Elemental analysis result: Elemental analysis calcd. (%) for C 104 H 166 O 14 P2Eu 0.0097 Tb 0.0062 Lu 1.9841 ,C60.87, H 8.15; found: C 60.70, H 8.16.

[0052] Example 5 [(EU 0.0032 Tb 0.0046 Lu 1.9922 Synthesis of )(tmh)6dpph] dpph (41.4 mg, 0.072 mmol), Eu(tmh)3, Tb(tmh)3, and Lu(tmh)3 were dissolved in methanol, and the solution was heated to reflux at 64 °C and stirred for 16 hours. Eu(tmh)3 weighed out at 0.49 mg (0.0007 mmol), Tb(tmh)3 weighed out at 0.50 mg (0.00071 mmol), and Lu(tmh)3 weighed out at 140.55 mg (0.194 mmol). The solution was filtered and recrystallized in methanol to give (Eu 0.0032 Tb 0.0046 Lu 1.9922)(tmh)6dcph (yield 81%, yield 115.4 mg) was obtained. ICP-AES:Eu / (Eu+Tb+Lu)=0.16%, Tb / (Eu+Tb+Lu)=0.23% Elemental analysis result: Elemental analysis calcd. (%) for C 104 H 142 O 14 P2Eu 0.0032 Tb 0.0046 Lu 1.9922 ,C61.59, H 7.06; found: C 61.10, H 7.10. [ka]

[0053] Example 6 [(EU 0.014 Tb 0.012 Gd 1.974 Synthesis of )(tmh)6dcph] dcph (72.7 mg, 0.12 mmol), Eu(tmh)3, Tb(tmh)3, and Gd(tmh)3 were dissolved in methanol, and the solution was heated to reflux at 70 °C and stirred for 4 hours. Eu(tmh)3 weighed out at 1.70 mg (0.0024 mmol), Tb(tmh)3 weighed out at 0.80 mg (0.0011 mmol), and Gd(tmh)3 weighed out at 162.65 mg (0.23 mmol). The solution was filtered and recrystallized in methanol to give (Eu 0.014 Tb 0.012 Gd 1.974 )(tmh)6dcph (yield 57%, yield 139.3 mg) was obtained. Eu / (Eu+Tb+Gd)=0.69%, Tb / (Eu+Tb+Gd)=0.62% Elemental analysis result: Elemental analysis calcd. (%) for C 104 H 166 O 14 P2Eu 0.0138 Tb 0.0124 Gd 1.9738, C 61.93, H 8.30; found: C 61.32, H 8.36.

[0054] Example 7 [(EU 0.020 Tb 0.012 Gd 1.968 Synthesis of )(tmh)6dcph] dcph (70.5 mg, 0.117 mmol), Eu(tmh)3, Tb(tmh)3, and Gd(tmh)3 were dissolved in methanol, and the solution was heated to reflux at 70 °C and stirred for 4 hours. Eu(tmh)3 weighed out at 1.66 mg (0.0024 mmol), Tb(tmh)3 weighed out at 0.85 mg (0.0012 mmol), and Gd(tmh)3 weighed out at 162.4 mg (0.23 mmol). The solution was filtered and recrystallized in methanol to give (Eu 0.020 Tb 0.012 Gd 1.968 )(tmh)6dcph (yield 53%, yield 126.2 mg) was obtained. Eu / (Eu+Tb+Gd)=1.03%, Tb / (Eu+Tb+Gd)=0.64% Elemental analysis result: Elemental analysis calcd. (%) for C 104 H 166 O 14 P2Eu 0.0206 Tb 0.0128 Gd 1.9666 , C 61.97, H 8.30; found: C 61.67, H 8.27.

[0055] 2. Optical properties Example 1 When irradiated with ultraviolet light at room temperature, the material emitted yellow light. When the irradiation was stopped and the ultraviolet light excitation was extinguished, an afterglow was observed, and the afterglow color changed from yellow to green over a period of approximately 1.2 seconds.

[0056] When irradiated with ultraviolet light at 250 K, the material emitted yellow light. When the ultraviolet light irradiation was stopped and the ultraviolet light excitation was extinguished, an afterglow was observed, and the afterglow color changed from yellow to green over a period of approximately 5 seconds, confirming time-chromic luminescence.

[0057] Example 2 When irradiated with ultraviolet light at room temperature, the material emitted a yellow-green light. When the ultraviolet light irradiation was stopped and the ultraviolet light excitation was extinguished, an afterglow was observed, and the afterglow color changed from yellow-green to green over a period of approximately 1.2 seconds, confirming time-chromic luminescence.

[0058] Example 3 When irradiated with ultraviolet light at room temperature, the material emitted a yellowish-white light. When the ultraviolet light irradiation was stopped and the ultraviolet light excitation was extinguished, an afterglow was observed, and the afterglow color changed from yellowish-white to yellow over a period of approximately 1.2 seconds, confirming time-chromic luminescence.

[0059] Example 4 When irradiated with ultraviolet light at room temperature, the material emitted a pink light. When the irradiation was stopped and the ultraviolet light excitation was extinguished, an afterglow was observed, which turned orange, and time-chromic luminescence was confirmed, lasting for approximately 1.2 seconds. Example 5 When the material was cooled with liquid nitrogen and exposed to ultraviolet light, it emitted a green light. When the ultraviolet light irradiation was stopped and the ultraviolet light excitation was extinguished, it exhibited an afterglow, and this afterglow color was confirmed to be time-chromic, lasting for approximately 0.2 seconds.

[0060] Example 6 When irradiated with ultraviolet light under conditions cooled with liquid nitrogen, the material emitted yellow light. When the irradiation of the ultraviolet light was stopped and the ultraviolet light excitation was extinguished, an afterglow was observed, and the afterglow color changed from yellow-green to green over a period of approximately 3.0 seconds, confirming time-chromic luminescence.

[0061] Example 7 When irradiated with ultraviolet light at room temperature, the material emitted yellow light. When the irradiation was stopped and the ultraviolet light excitation was extinguished, an afterglow was observed, and the afterglow color changed from yellow to green over a period of approximately 3.0 seconds, confirming time-chromic luminescence.

[0062] Time-chromic luminescence was confirmed after irradiation with ultraviolet light for the luminescent materials obtained in Examples 1 to 7. Such luminescent materials are useful in authentication technology. [Explanation of symbols]

[0063] 1...Luminescent material.

Claims

1. three or more kinds of rare earth element ions and a linker ligand that forms a coordinate bond with two to four of the rare earth element ions; a light-emitting material, wherein the three or more kinds of rare earth element ions and the linker ligand form a rare earth complex; The three or more kinds of rare earth element ions are at least two rare earth element ions A selected from the group consisting of Yb(III), Nd(III), Sm(III), Eu(III), Tb(III), Dy(III), Ce(III), Pr(III), Ho(III), Er(III), and Tm(III); at least one rare earth element ion B selected from the group consisting of Y(III), La(III), Gd(III), and Lu(III); Including, The linker ligand is a linker group and a substituent bonded to the linker group, the substituent comprising a coordinating functional group that forms a coordinate bond with a rare earth element ion; or a linker group containing a coordinate-bonding functional group that forms a coordinate bond with a rare earth element ion; Luminescent material.

2. 2. The light-emitting material of claim 1, wherein the linker group is a group comprising two or more aromatic rings bonded together via a covalent bond, or a fused polycyclic aromatic group.

3. The light-emitting material of claim 1 , wherein the coordinating functional group is a phosphine oxide group.

4. 10. The light-emitting material of claim 1, further comprising a non-linker ligand that forms a coordinate bond with one of the rare earth ions.

5. The light-emitting material according to claim 4 , wherein the non-linker ligand comprises at least one of a diketonato ligand represented by the following general formula (10) or a carboxylato ligand represented by the following general formula (20): 【Chemical 1】 [In formula (10), R １１ and R １２ each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted trialkylsilyl group, R １１ or R １２ at least one of is a substituted or unsubstituted alkyl group having 2 or more carbon atoms, a substituted or unsubstituted trialkylsilyl group, or a substituted or unsubstituted aromatic group, R １３ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic group, R １３ is R １１ or R １２ may be bonded to form a cyclic group.] 【Chemistry 2】 [In formula (20), R ２１ , R ２２ , R ２３ , R ２４ , and R ２５ each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted trialkylsilyl group, or a substituted or unsubstituted aromatic group, R ２１ , R ２２ , R ２３ , R ２４ , and R ２５ At least two of the groups are a halogen atom, a substituted or unsubstituted alkyl group having two or more carbon atoms, a substituted or unsubstituted trialkylsilyl group, or a substituted or unsubstituted aromatic group.

6. 2. The luminescent material according to claim 1, wherein some of the linker ligands in the luminescent material form rare earth complexes with two or more rare earth element ions B.

7. The luminescent material according to claim 6 , comprising a mixed crystal containing three or more of the rare earth complexes.

8. 2. The luminescent material according to claim 1, wherein the content of the rare earth element ion A is 30 mass % or less based on the total mass of the rare earth element ion A and the rare earth element ion B.

9. the at least two rare earth ions A include a first rare earth ion A1 and a second rare earth ion A2; 2. The luminescent material of claim 1, wherein the content of the first rare earth element ion A1 is different from the content of the second rare earth element ion A2.

10. A coating material comprising the luminescent material according to any one of claims 1 to 9 and a dispersion medium in which the luminescent material is dispersed.

11. A printed matter comprising the luminescent material according to any one of claims 1 to 9 and a substrate to which the luminescent material is attached.

12. A resin molded article which is a cured product of a mixture containing the light-emitting material according to any one of claims 1 to 9 and a resin.

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