Method for producing rare earth metal complex, rare earth metal complex and light emitting device

Abstract

To provide a method for producing a rare earth metal complex that can enhance light-emitting characteristics, and to provide a rare earth metal complex and a light-emitting device.SOLUTION: A method for producing a rare earth metal complex includes preparing a first solution that contains an aprotic polar solvent in which a first rare earth metal complex containing a Schiff base ligand and a β-diketonate ligand and a rare earth metal atom is dissolved, and a second solution that contains a non-polar solvent in which the first rare earth metal complex does not dissolve, and bringing the first solution and the second solution into contact to precipitate a second rare earth metal complex that contains a Schiff base ligand and a β-diketonate ligand and a rare earth metal atom.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a rare earth metal complex, a rare earth metal complex, and a light emitting device. [Background technology]

[0002] Rare earth metal complexes are used in light-emitting components such as fluorescent probes, laser emitters, bioimaging, sensors, security inks, and lighting. Some rare earth metal complexes can be excited by relatively short-wavelength blue visible light to emit light of long wavelengths, and are expected to be used in light-emitting devices in combination with light-emitting elements such as light-emitting diodes (hereinafter also referred to as "LEDs") and laser diodes (hereinafter also referred to as "LDs").

[0003] It has been reported that rare earth metal complex compositions containing rare earth metal complexes exhibit various luminescence quantum efficiencies. For example, Patent Document 1 discloses a rare earth metal complex having a β-diketonato ligand and a phenanthryl ligand. Patent Document 2 discloses a rare earth metal complex having a Pybox derivative ligand and a Cyclen derivative ligand. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-031348 A [Patent Document 2] JP 2007-238650 A Summary of the Invention [Problem to be solved by the invention]

[0005] There is a demand for further improving the luminescence properties of rare earth metal complexes. An object of one embodiment of the present invention is to provide a method for producing a rare earth metal complex, a rare earth metal complex, and a light emitting device that can improve light emitting characteristics. [Means for solving the problem]

[0006] A first aspect of the present invention is a method for producing a rare earth metal complex, comprising: preparing a first solution containing an aprotic polar solvent dissolving a first rare earth metal complex containing a Schiff base ligand, a β-diketonato ligand, and a rare earth metal atom; and a second solution containing a nonpolar solvent in which the first rare earth metal complex is not dissolved; and contacting the first solution with the second solution to precipitate a second rare earth metal complex containing the Schiff base ligand, the β-diketonato ligand, and a rare earth metal atom.

[0007] A second aspect of the present invention is a rare earth metal complex comprising a Schiff base ligand, a β-diketonato ligand, and a rare earth metal atom, the rare earth metal complex having a median particle size Dm measured by a laser diffraction scattering method in the range of 10 μm or more and 30 μm or less, and an excitation efficiency at 450 nm in the excitation spectrum of the rare earth metal complex of 80% or more.

[0008] A third aspect of the present invention is a light emitting device comprising the rare earth metal complex and an excitation light source. Effect of the Invention

[0009] According to one aspect of the present invention, it is possible to provide a method for producing a rare earth metal complex, a rare earth metal complex, and a light emitting device that can improve light emitting characteristics. [Brief description of the drawings]

[0010] [Figure 1] 1 is a flowchart showing a first example of a method for producing a rare earth metal complex according to a first embodiment. [Diagram 2] 4 is a flowchart showing a second example of the method for producing a rare earth metal complex according to the first embodiment. [Diagram 3] 1 is a schematic cross-sectional view showing a schematic configuration of an example of a light-emitting device. [Figure 4] FIG. 1 is a schematic perspective view showing a schematic configuration of an example of a light emitting device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The method for producing a rare earth metal complex, the rare earth metal complex, and the light emitting device according to the present invention will be described below based on one embodiment. However, the embodiment shown below is an example for realizing the technical idea of ​​the present invention, and the present invention is not limited to the wavelength conversion member and the light emitting device shown below. The relationship between the color name and the chromaticity coordinate, and the relationship between the wavelength range of light and the color name of monochromatic light are in accordance with JIS Z8110.

[0012] Method for producing rare earth metal complex A method for producing a rare earth metal complex includes preparing a first solution containing an aprotic polar solvent dissolving a first rare earth metal complex containing a Schiff base ligand, a β-diketonato ligand, and a rare earth metal atom, and a second solution containing a nonpolar solvent in which the first rare earth metal complex is not dissolved, and contacting the first solution with the second solution to precipitate a second rare earth metal complex containing the Schiff base ligand, the β-diketonato ligand, and a rare earth metal atom.

[0013] A first solution containing an aprotic polar solvent in which a first rare earth metal complex is dissolved and a second solution containing a non-polar solvent in which the first rare earth metal complex is not dissolved are prepared, and the first solution is brought into contact with the second solution, and the second rare earth metal complex is precipitated due to the difference in solubility between the first solution and the second solution. The second rare earth metal complex obtained by precipitating the second rare earth metal complex has a central particle size Dm of 10 μm or more as measured by a laser diffraction scattering method. In addition, the obtained second rare earth metal complex has an excitation efficiency of 80% or more at 450 nm in the excitation spectrum of the second rare earth metal complex, and has higher brightness and quantum efficiency than the first rare earth metal complex.

[0014] The first rare earth metal complex The first rare earth metal complex is a complex in which a Schiff base ligand and a β-diketonato ligand are both coordinated to the first rare earth metal atom. The rare earth metal atom Ln contained in the first rare earth metal complex is preferably at least one selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. The rare earth metal atom Ln contained in the first rare earth metal complex is more preferably at least one selected from the group consisting of Eu, Sm, Dy, Tb and Tm, more preferably at least one selected from the group consisting of Eu, Sm, Dy and Tm, and particularly preferably Eu. These rare earth metal atoms Ln may be used alone or in combination of two or more.

[0015] The first rare earth metal complexes: Schiff base ligands The Schiff base ligand contained in the first rare earth metal complex is preferably a ligand having two pairs of azomethine groups represented by the following chemical formula (II). [ka] [In the chemical formula (II), A 1 represents an OH group, an SH group, or an OD group, A 2 indicates a methyl group, A 3 represents a bonding group selected from C2 to C6 alkylene groups.]

[0016] The Schiff base ligand represented by the chemical formula (I) described below is a rare earth metal (Eu III The Schiff base ligand represented by formula (II) is composed of two pairs of A 1 One of the A 1 Only the rare earth metal atom may form a coordinate bond with the A 1 and may form coordinate bonds with the same rare earth metal atom or with different rare earth metal atoms.

[0017] The Schiff base ligand contained in the first rare earth metal complex is more preferably a ligand having two pairs of hydroxyl groups and an azomethine group, as represented by the following chemical formula (III): The Schiff base ligand represented by chemical formula (III) may form a coordinate bond with a rare earth metal atom with only one of the two pairs of hydroxyl groups, or may form coordinate bonds with the same rare earth metal atom or different rare earth metal atoms with both hydroxyl groups. [ka]

[0018] The first rare earth metal complexes: β-diketonato ligands The β-diketonato ligand contained in the first rare earth metal complex is preferably a β-diketonato ligand represented by the following chemical formula (IV). [ka] [In the chemical formula (IV), X may be the same or different; aromatic group; Perhalogenated aromatic groups; Heteroaromatic groups containing at least one heteroatom in the ring; A linear or branched C1 to C30 alkyl group, and one or more substituents selected from linear or branched C1 to C30 perhalogenated alkyl groups; Z represents a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a methyl group, an ethyl group, a phenyl group, a hydrogen atom, or a deuterium atom.

[0019] The β-diketonato ligand is a monovalent anion that can coordinate to a rare earth metal atom through two oxygen atoms (O). The β-diketonato ligand can form two coordinate bonds with the rare earth metal atom.

[0020] The β-diketonato ligand contained in the first rare earth metal complex is more preferably a β-diketonato ligand represented by the following chemical formula (V). [ka]

[0021] The first rare earth metal complex is preferably any one of a rare earth metal complex represented by the following chemical formula (VI), a rare earth metal complex having a chain structure represented by the following chemical formula (VI'), and a rare earth metal complex having a cyclic structure represented by the following chemical formula (VI"). The first rare earth metal complex preferably has a coordination structure represented by any one of the following chemical formulas (VI), (VI') and (VI"). The first rare earth metal complex is preferably at least one of the rare earth metal complexes represented by the following chemical formulas (VI), (VI') and (VI"), and may include two or more of the rare earth metal complexes represented by the following chemical formulas (VI), (VI') and (VI"), or may include three of the rare earth metal complexes represented by the following chemical formulas (VI), (VI') and (VI").

[0022] [ka] [ka] [ka] [In the chemical formulas (VI), (VI') and (VI"), Ln is at least one rare earth metal atom selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu; A 1 , A 2 and A 3 is the same as that of formula (II), X and Z are as defined in formula (IV); n1 represents 2 or 3; n2 represents an integer from 1 to 3; n3 represents an integer of 2 or more.

[0023] The first rare earth metal complex is preferably any one of a rare earth metal complex represented by the following chemical formula (I), a rare earth metal complex having a chain structure represented by the following chemical formula (I'), and a rare earth metal complex having a cyclic structure represented by the following chemical formula (I"). The first rare earth metal complex preferably has a coordination structure represented by any one of the following chemical formulas (I), (I') and (I"). The first rare earth metal complex is preferably at least one of the rare earth metal complexes represented by the following chemical formulas (I), (I') and (I"), and may contain two or more of the rare earth metal complexes represented by the following chemical formulas (I), (I') and (I"), or may contain three of the rare earth metal complexes represented by the following chemical formulas (I), (I') and (I"). The first rare earth metal complex is [HO-CH6H4-C(CH3)=N-(CH2)4-N=C(CH3)-C6H4-OH]-Eu III -(CF3-CO-CH2-CO-C6H 5)3 The rare earth metal complex may be represented by the formula: 50 H 42 EU III F9N2O6, Schiff base ligands are coordinated to β-diketonato ligands. III ) and may form a crystal structure, and the Schiff base ligand is a rare earth metal (Eu) with a hydroxyl group (OH). III ) in a chain or ring form. [ka] [ka] [ka] [In chemical formulas (I), (I') and (I"), n represents an integer of 1 to 3.]

[0024] In the chemical formulas (I) to (VI), A 1 or a dotted line extending from a hydroxyl group (OH), A 1 and Ln or rare earth metals (Eu III ), the dotted line between O and Ln or rare earth metal (EuIII Each dotted line between the atoms indicates one coordinate bond.

[0025] Preparing a first solution and a second solution The first solution contains an aprotic polar solvent having the first rare earth metal complex dissolved therein, and the second solution contains a non-polar solvent in which the first rare earth metal complex is not soluble.

[0026] Aprotic Polar Solvents The aprotic polar solvent in which the first rare earth metal complex is dissolved to form the first solution is preferably at least one selected from the group consisting of tetrahydrofuran and dichloromethane. If the aprotic polar solvent is at least one selected from the group consisting of tetrahydrofuran and dichloromethane, it can be used as a good solvent for dissolving the first rare earth metal complex, and the central particle size Dm measured by the laser diffraction scattering method becomes 10 μm or more, and the excitation efficiency at 450 nm in the excitation spectrum becomes 80% or more, and a second rare earth metal complex having higher luminescence characteristics than the first rare earth metal complex can be obtained. The aprotic solvent is preferably one having a relative dielectric constant of 5 or more so that the solubility of the first rare earth metal complex is high. The relative dielectric constant of tetrahydrofuran is 7.5, and the relative dielectric constant of dichloromethane is 8.9.

[0027] Non-polar solvents The non-polar solvent in which the first rare earth metal complex does not dissolve is preferably at least one selected from the group consisting of hexane, toluene, and methylcyclohexane. The second solution containing at least one non-polar solvent selected from the group consisting of hexane, toluene, and methylcyclohexane as a non-polar solvent can be used as a poor solvent in which the first rare earth metal complex does not dissolve. Due to the difference in solubility of the first rare earth metal complex between the first solution and the second solution, the median particle size Dm measured by the laser diffraction scattering method becomes larger than 10 μm, and the excitation efficiency at 450 nm in the excitation spectrum of the rare earth metal complex becomes 80% or more, and a second rare earth metal complex having higher luminescence characteristics than the first rare earth metal complex can be obtained.

[0028] Step 1 of precipitating a second rare earth metal complex In the step of precipitating the second rare earth metal complex, the first solution may be continuously dropped into the second solution while continuously stirring the second solution to precipitate the second rare earth metal complex. In the step of precipitating the second rare earth metal complex, the method of continuously dropping the first solution into the second solution while continuously stirring the second solution to precipitate the second rare earth metal complex is also called a reprecipitation method. FIG. 1 is a flow chart showing a first example of a method for producing a rare earth metal complex of the first embodiment. The first example of the method for producing a rare earth metal complex of the first embodiment includes a step S101 of preparing a first solution and a second solution, and a step S102 of precipitating the second rare earth metal complex. The step S102 of precipitating the second rare earth metal complex may include a step S102-1 of dropping the first solution into the second solution. In the step S102-1 of dropping the first solution into the second solution, it is preferable to continuously drop the first solution while continuously stirring the second solution.

[0029] In the case of a reprecipitation method in which the first solution is continuously dropped into the second solution, the concentration of the first rare earth metal complex in the first solution is preferably in the range of 0.01 mol / L to 0.027 mol / L, may be in the range of 0.011 mol / L to 0.026 mol / L, or may be in the range of 0.012 mol / L to 0.025 mol / L. When the first solution is continuously dropped into the second solution, if the concentration of the first rare earth metal complex in the first solution is in the range of 0.01 mol / L to 0.027 mol / L, the median particle size Dm measured by the laser diffraction scattering method becomes 10 μm or more, the excitation efficiency at 450 nm in the excitation spectrum of the rare earth metal complex becomes 80% or more, and a second rare earth metal complex having higher luminescence characteristics than the first rare earth metal complex can be obtained.

[0030] In the step of precipitating the second rare earth metal complex, when a reprecipitation method is used in which the first solution is continuously dropped into the second solution, it is preferable that the volume ratio of the first solution to the second solution (first solution / second solution) is 1 to 5, and the stirring speed of the second solution is in the range of 200 rpm to 400 rpm. When the first solution is continuously dropped into the second solution, the volume ratio of the first solution to the second solution (first solution / second solution) may be 1 to 4, 1 to 3, 1 to 2, or 1:1. When the first solution is continuously dropped into the second solution, it is more preferable that the stirring speed of the second solution is in the range of 210 rpm to 380 rpm, and even more preferably in the range of 220 rpm to 370 rpm. When the first solution is continuously dropped into the second solution, if the volume ratio of the first solution to the second solution is 1 to 5 and the stirring speed of the second solution is within the range of 200 rpm or more and 400 rpm or less, the median particle size Dm measured by laser diffraction scattering method becomes 10 μm or more, the excitation efficiency at 450 nm in the excitation spectrum of the rare earth metal complex becomes 80% or more, and a second rare earth metal complex having better luminescence properties than the first rare earth metal complex can be obtained.

[0031] In the step of precipitating the second rare earth metal complex, when the reprecipitation method is used in which the first solution is continuously dropped into the second solution, the dropping speed of the first solution is preferably in the range of 1 mL / min to 5 mL / min, and may be in the range of 2 mL / min to 4 mL / min. When the first solution is continuously dropped into the second solution, if the dropping speed of the first solution is in the range of 1 mL / min to 5 mL / min, the median particle size Dm measured by the laser diffraction scattering method becomes 10 μm or more, and the excitation efficiency at 450 nm in the excitation spectrum of the rare earth metal complex becomes 80% or more, and a second rare earth metal complex having higher luminescence characteristics than the first rare earth metal complex can be obtained.

[0032] Step 2 of precipitating a second rare earth metal complex In the step of precipitating the second rare earth metal complex, the second solution may be dropped into the first solution to precipitate the second rare earth metal complex. In the step of precipitating the second rare earth metal complex, the method of dropping the second solution into the first solution to precipitate the second rare earth metal complex is also called a recrystallization method. FIG. 2 is a flow chart showing a second example of the method for producing a rare earth metal complex of the first embodiment. The second example of the method for producing a rare earth metal complex of the first embodiment includes a step S101 of preparing a first solution and a second solution, and a step S102 of precipitating the second rare earth metal complex. The step S102 of precipitating the second rare earth metal complex may include a step S102-2 of dropping the second solution into the first solution. In the step S102-2 of dropping the second solution into the first solution, it is preferable that the first solution is not stirred.

[0033] In the case of a recrystallization method in which the second solution is dropped into the first solution, the concentration of the first rare earth metal complex in the first solution is preferably in the range of 0.01 mol / L to 0.023 mol / L, may be in the range of 0.011 mol / L to 0.022 mol / L, or may be in the range of 0.012 mol / L to 0.021 mol / L. When the second solution is dropped into the first solution, if the concentration of the first rare earth metal complex in the first solution is in the range of 0.01 mol / L to 0.023 mol / L, the central particle size Dm measured by the laser diffraction scattering method becomes 10 μm or more, and the excitation efficiency at 450 nm in the excitation spectrum of the rare earth metal complex becomes 80% or more, and a second rare earth metal complex having higher luminescence characteristics than the first rare earth metal complex can be obtained.

[0034] In the step of precipitating the second rare earth metal complex, when a recrystallization method is used in which the second solution is dropped into the first solution, the volume ratio of the first solution to the second solution (first solution / second solution) is preferably 1 to 5, and may be 1 to 4, 1 to 3, 1 to 2, or 1:1. When the second solution is dropped into the first solution, if the volume ratio of the first solution to the second solution is 1 to 5, the median particle size Dm measured by a laser diffraction scattering method becomes 10 μm or more, and the excitation efficiency at 450 nm in the excitation spectrum of the rare earth metal complex becomes 80% or more, and a second rare earth metal complex having higher luminescence properties than the first rare earth metal complex can be obtained.

[0035] In the step of precipitating the second rare earth metal complex, when a recrystallization method is used in which the second solution is dropped into the first solution, the dropping speed is not particularly limited, and when the volume ratio of the first solution to the second solution is 1 to 5, the second solution may be added to the first solution all at once, and the dropping speed of the second solution may be within the range of 2 mL / min to 20 mL / min, may be within the range of 2 mL / min to 15 mL / min, or may be within the range of 2 mL / min to 10 mL / min.

[0036] Secondary rare earth metal complexes The second rare earth metal complex is preferably represented by the same chemical formula as the first rare earth metal complex, and is preferably at least one of the rare earth metal complexes represented by the chemical formulae (VI), (VI') and (VI"), and may contain two or more of the rare earth metal complexes represented by the chemical formulae (VI), (VI') and (VI"), or may contain three of the rare earth metal complexes represented by the chemical formulae (VI), (VI') and (VI"). The second rare earth metal complex is preferably at least one of the rare earth metal complexes represented by the chemical formulae (I), (I') and (I"), and may contain two or more of the rare earth metal complexes represented by the chemical formulae (I), (I') and (I"), or may contain three of the rare earth metal complexes represented by the chemical formulae (I), (I') and (I").

[0037] Rare Earth Metal Complexes The rare earth metal complex of the second embodiment is a rare earth metal complex containing a Schiff base ligand, a β-diketonato ligand, and a rare earth metal atom, and has a central particle size Dm measured by a laser diffraction scattering method within the range of 10 μm to 30 μm, and an excitation efficiency at 450 nm of 80% or more in the excitation spectrum of the rare earth metal complex. When the rare earth metal complex has a central particle size Dm measured by a laser diffraction scattering method within the range of 10 μm to 30 μm, it can absorb light from an excitation light source well, convert the wavelength, and emit light with high brightness. In addition, when the rare earth metal complex has an excitation efficiency of 80% or more at 450 nm in the excitation spectrum, it becomes easy to absorb the excitation light of LED and LD semiconductor light emitting element having an emission peak wavelength within the range of 380 nm to 450 nm, more specifically, light having an emission peak wavelength at 450 nm, and easily emits light with high brightness. The rare earth metal complex is preferably manufactured by the above-mentioned manufacturing method. The median particle size Dm of the rare earth metal complex may be in the range of 11 μm to 28 μm, or in the range of 12 μm to 25 μm. The laser diffraction scattering method is a method for measuring particle size without distinguishing between primary particles and secondary particles by using scattered light of a laser beam irradiated onto particles of a rare earth metal complex. The median particle size Dm measured by the laser diffraction scattering method is the median particle size (median diameter: Dm) at which the volume cumulative frequency from the small diameter side reaches 50% in the volume-based particle size distribution measured by the laser diffraction scattering method. The median particle size measured by the laser diffraction scattering method can be measured, for example, using a laser diffraction scattering type particle size distribution measuring device (MASTER SIZER 3000, manufactured by MALVERN).

[0038] The rare earth metal complex is preferably one represented by the same chemical formula as the first rare earth metal complex and the second rare earth metal complex described above, more preferably at least one of the rare earth metal complexes represented by the chemical formulas (VI), (VI') and (VI"), and further preferably at least one of the rare earth metal complexes represented by the chemical formulas (I), (I') and (I").

[0039] Light-emitting device The light emitting device of the third aspect is a light emitting device including the rare earth metal complex and an excitation light source. The rare earth metal complex may be contained in a wavelength conversion member of the light emitting device. The excitation light source of the light emitting device is preferably a semiconductor light emitting element made of an LED chip or an LD chip. The semiconductor light emitting element is preferably a nitride semiconductor (In X Al Y Ga 1-X-Y N, 0≦X, 0≦Y, X+Y≦1) can be used. By using a semiconductor light-emitting element as the excitation light source, it is possible to obtain a light-emitting device that is highly efficient, has high output linearity with respect to input, and is stable and resistant to mechanical shock.

[0040] The wavelength conversion member containing a rare earth metal complex may contain a resin or an inorganic phosphor in addition to the rare earth metal complex. Examples of the resin include silicone resin, epoxy resin, acrylic resin, and modified resins thereof. Examples of the inorganic phosphor include fluoride phosphors containing Mn. The wavelength conversion member may include a wavelength conversion sheet containing a rare earth metal complex and a light-transmitting member. Examples of the light-transmitting member include a plate-shaped body made of a light-transmitting material such as glass or resin.

[0041] 3 and 4 show an example of the light emitting device of the third embodiment, and Fig. 3 is a schematic cross-sectional view showing the light emitting device 100. Fig. 4 is a schematic perspective view of the light emitting device 100.

[0042] The light emitting device 100 shown in FIGS. 3 and 4 is of a side light emitting type (also called a "side view type"), but it can also be of an upper light emitting type (also called a "top view type").

[0043] The light emitting device 100 includes a light emitting element 10 serving as an excitation light source, and a wavelength conversion member 50. The wavelength conversion member 50 includes a wavelength conversion sheet 20 including a rare earth metal complex, a resin, and an inorganic phosphor as required, a light-transmitting gas barrier film 30 as required, and a light-transmitting member 40. The light emitting element 10 may be flip-chip mounted on wiring 91 of a substrate 90 via a conductive adhesive 60. The substrate 90 includes wiring 91 and a base 92 that holds the wiring 91. The wavelength conversion member 50 is bonded such that the light incident surface 20a of the wavelength conversion sheet 20 is bonded to one surface of the light emitting element 10 via a light guide member 80. The covering member 70 is formed on the substrate 90, covers the side surfaces of the wavelength conversion member 50 including the conductive adhesive 60, the light emitting element 10, the light guide member 80, the wavelength conversion sheet 20, the gas barrier film 30, and the light-transmitting member 40, and surrounds the entire periphery of the conductive adhesive 60, the light emitting element 10, the light guide member 80, and the wavelength conversion member 50. The front surface of the wavelength conversion member 50 and the front surface of the covering member 70 form substantially the same surface. EXAMPLES

[0044] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to these examples.

[0045] Rare Earth Metal Complexes The following raw materials were used:

[0046] Schiff base (ligand having a hydroxyl group and an azomethine group) (a) (a1) N,N'-bis(p-hydroxyphenylacetylidene)1,4-butylenediamine (H21,4-acebn) [HO-CH6H4-C(CH3)=N-(CH2)4-N=C(CH3)-C6H4-OH] (Both benzene rings are ortho-substituted.)

[0047] [ka]

[0048] β-diketonate ligand (b) (b1) Benzoyltrifluoroacetone (btfa) [CF3-CO-CH2-CO-C6H5] The monovalent anionic β-diketonato ligand is called "btfa - "It is also called.

[0049] [ka]

[0050] Metal salts containing rare earth metal atoms (c) (c1) Europium chloride [EuCl3(H2O)6]

[0051] Rare earth metal complexes: H21,4-acebn and btfa - Synthesis of europium-containing complexes with co-coordinated cations. (c1) Europium chloride [EuCl3(H2O)6: 2.2 g] was dissolved in 30 mL of ethanol. (b1) Benzoyltrifluoroacetone (btfa) [CF3-CO-CH2-CO-C6H5: 3.9 g] was added, and the pH was adjusted to 7 with an aqueous ammonia solution, followed by stirring at room temperature for 4 hours. After stirring, the mixture was added to 300 mL of pure water, stirred for 12 hours, and the precipitated solid was filtered. The distilled water was removed by vacuum distillation to obtain a white product. 1.67 g of the obtained white product was dissolved in 30 mL of dichloromethane. (a1) 0.65 g of H21,4-aceben (both benzene rings are ortho-substituted) was added and stirred at room temperature for 24 hours. The precipitated solid was filtered. Dichloromethane was removed by distillation under reduced pressure to obtain a yellow product, a rare earth metal complex represented by the following chemical formulae (I), (I') and (I"). The rare earth metal complex was presumed to be a mixture of the rare earth metal complexes represented by the following chemical formulae (I), (I') and (I"). It is very difficult to individually separate the rare earth metal complexes represented by the following chemical formulae (I), (I') and (I").

[0052] [ka] [ka] [ka] In formulas (I), (I') and (I"), n represents an integer from 1 to 3, and more specifically, n represents 2 or 3.

[0053] Example 1 The rare earth metal complexes represented by the chemical formulas (I), (I') and (I") were used as the first rare earth metal complex. Reprecipitation method 1 3 g of rare earth metal complexes represented by chemical formulas (I), (I') and (I") were dissolved in 100 mL of tetrahydrofuran to prepare the first solution. As the second solution, 500 mL of hexane (5 times the volume) was placed in a 1 L beaker and stirred with a stirrer. While continuously stirring the second solution, the first solution was continuously added dropwise at a rate of 6.6 mL / min using a tube pump. After 20 hours, the precipitate was filtered and dried. The recovery rate of the second rare earth metal complex was 95%.

[0054] Example 2 The rare earth metal complexes represented by the chemical formulas (I), (I') and (I") were used as the first rare earth metal complex. Reprecipitation method 2 3 g of rare earth metal complexes represented by chemical formulas (I), (I') and (I") were dissolved in 100 mL of tetrahydrofuran to prepare the first solution. As the second solution, 400 mL of hexane (four times the amount) was placed in a 1 L beaker and stirred with a stirrer. While continuously stirring the second solution, the first solution was continuously added dropwise at a rate of 12.5 mL / min using a tube pump. After 20 hours, the precipitate was filtered and dried. The recovery rate of the second rare earth metal complex was 89%.

[0055] Example 3 The rare earth metal complexes represented by the chemical formulas (I), (I') and (I") were used as the first rare earth metal complex. Recrystallization Method 1 4 g of rare earth metal complexes represented by chemical formulas (I), (I') and (I") were dissolved in 150 mL of tetrahydrofuran to prepare the first solution, which was placed in a 1 L beaker. As the second solution, 500 mL of dichloromethane, which was 3.3 times the amount of the first solution, was slowly poured into the first solution. This was done because the second solution could not be dropped into the first solution using a tube pump. The first solution into which the second solution had been poured was covered with aluminum foil, and after 2 days, the precipitate was filtered off and dried. The recovery rate of the second rare earth metal complex was 55%.

[0056] Comparative Example 1 The rare earth metal complexes represented by the chemical formulae (I), (I') and (I"), each having a median particle size Dm of 19.0 μm as measured by a laser diffraction scattering method, were used as the rare earth metal complexes of Comparative Example 1.

[0057] Evaluation method Median particle size Dm and standard deviation by laser diffraction scattering method For each of the rare earth metal complexes in the Examples and Comparative Examples, the median particle size Dm at which the volume cumulative frequency from the small diameter side reaches 50% in the volume-based particle size distribution was measured by a laser diffraction scattering method using a laser diffraction scattering type particle size distribution measuring device (MASTER SIZER3000, manufactured by MALVERN) and the standard deviation (σlog).

[0058] Relative luminance (%), chromaticity coordinates (x, y), energy efficiency (%) For each rare earth metal complex of the examples and comparative examples, an excitation light having an emission peak wavelength of 450 nm was irradiated using a quantum efficiency measurement system (QE-2100, manufactured by Otsuka Electronics Co., Ltd.), and an emission spectrum from 500 nm to 830 nm was measured, and from the emission spectrum, the emission luminance, the chromaticity coordinates (x, y) in the chromaticity coordinate system of the CIE (Commission Internationale de l'Eclairage) 1931 chromaticity diagram, and the energy efficiency were measured. The relative emission luminance was expressed as the emission luminance of the rare earth metal complex of Comparative Example 1 as 100%, and the emission luminance of the rare earth metal complexes of Examples 1 to 3 was expressed as the relative emission luminance (%).

[0059] Excitation efficiency (%) Using a spectrofluorometer (F-4500, Hitachi High-Technologies Corporation), the excitation spectrum was measured at excitation wavelengths in the range of 220 nm to 570 nm. The highest intensity was set as 100%, and the intensity at 450 nm was measured as the excitation efficiency relative to 100%.

[0060] [Table 1]

[0061] The rare earth metal complexes according to Examples 1 to 3 had a median particle size Dm measured by a laser diffraction scattering method within a range of 10 μm to 30 μm. The rare earth metal complexes according to Examples 1 to 3 had a standard deviation of 1.2 or less, and had small particle size variations. Furthermore, the rare earth metal complexes according to Examples 1 to 3 had higher relative luminance and better luminescence characteristics than Comparative Example 1. Furthermore, the rare earth metal complexes according to Examples 1 to 3 had an excitation efficiency of 80% or more at 450 nm in the excitation spectrum. [Industrial Applicability]

[0062] The embodiments of the present disclosure are useful for various lighting light sources, in-vehicle light sources, display light sources, etc. In particular, they can be advantageously applied to backlight units for liquid crystal display devices. The light-emitting device according to the embodiments of the present disclosure is also advantageous for backlights for display devices of mobile devices. They can be used as light-emitting devices for general lighting and light-emitting devices for vehicles. [Explanation of symbols]

[0063] 10: light emitting element, 20: wavelength conversion sheet, 30: gas barrier film, 40: light transmissive member, 50: wavelength conversion member, 60: conductive adhesive, 70: covering member, 80: light guiding member, 90: substrate, 100: light emitting device.

Claims

1. preparing a first solution containing an aprotic polar solvent in which a first rare earth metal complex containing a Schiff base ligand, a β-diketonato ligand, and a rare earth metal atom is dissolved, and a second solution containing a nonpolar solvent in which the first rare earth metal complex is not dissolved; contacting the first solution with the second solution to precipitate a second rare earth metal complex comprising a Schiff base ligand, a β-diketonato ligand, and a rare earth metal atom to obtain a composition comprising the second rare earth metal complex; The second rare earth metal complex includes at least one rare earth metal complex represented by the following chemical formulas (I), (I'), and (I''): A method for producing a composition containing a rare earth metal complex, wherein the composition containing the second rare earth metal complex has a median particle size Dm in the range of 10 μm or more and 30 μm or less, as measured by a laser diffraction scattering method, and an excitation efficiency at 450 nm in an excitation spectrum of the composition containing the second rare earth metal complex is 80% or more. 【Chemistry 16】 【Chemistry 17】 【Chemistry 18】 [In chemical formulas (I') and (I''), n represents an integer of 2 or 3.]

2. 2. The method for producing a composition containing a rare earth metal complex according to claim 1, wherein in the step of precipitating the second rare earth metal complex to obtain a composition containing the second rare earth metal complex, the first solution is continuously dropped into the second solution while continuously stirring the second solution to precipitate the second rare earth metal complex.

3. 3. The method for producing a composition containing a rare earth metal complex according to claim 1 or 2, wherein in the step of precipitating the second rare earth metal complex to obtain a composition containing the second rare earth metal complex, a concentration of the first rare earth metal complex in the first solution is within a range of 0.01 mol / L or more and 0.027 mol / L or less.

4. 4. The method for producing a composition containing a rare earth metal complex according to claim 2 or 3, wherein in the step of precipitating the second rare earth metal complex to obtain a composition containing the second rare earth metal complex, a volume ratio of the first solution to the second solution (first solution / second solution) is from 1 to 5, and a stirring speed of the second solution is within a range of 200 rpm or more and 400 rpm or less.

5. 5. The method for producing a composition containing a rare earth metal complex according to claim 2, wherein in the step of precipitating the second rare earth metal complex to obtain a composition containing the second rare earth metal complex, a dropwise rate of the first solution is within a range of 1 mL / min to 5 mL / min.

6. 2. The method for producing a composition containing a rare earth metal complex according to claim 1, wherein in the step of precipitating the second rare earth metal complex to obtain a composition containing the second rare earth metal complex, the second solution is dropped into the first solution to precipitate the second rare earth metal complex.

7. 7. The method for producing a composition containing a rare earth metal complex according to claim 6, wherein in the step of precipitating the second rare earth metal complex to obtain a composition containing the second rare earth metal complex, a concentration of the first rare earth metal complex in the first solution is within a range of 0.01 mol / L or more and 0.023 mol / L or less.

8. 8. The method for producing a composition containing a rare earth metal complex according to claim 6 or 7, wherein in the step of precipitating the second rare earth metal complex to obtain a composition containing the second rare earth metal complex, a volume ratio of the first solution to the second solution (first solution / second solution) is 1 to 5.

9. 9. The method for producing a composition containing a rare earth metal complex according to claim 1, wherein in the step of preparing the first solution and the second solution, the aprotic polar solvent is at least one selected from the group consisting of tetrahydrofuran and dichloromethane.

10. 10. The method for producing a composition containing a rare earth metal complex according to claim 1, wherein in the step of preparing the first solution and the second solution, the non-polar solvent is at least one selected from the group consisting of hexane, toluene, and methylcyclohexane.

11. A composition comprising a rare earth metal complex, the composition comprising at least one rare earth metal complex represented by the following chemical formulas (I), (I′) and (I″), which comprises a Schiff base ligand, a β-diketonato ligand and a rare earth metal atom: A composition containing a rare earth metal complex, wherein the composition has a median particle size Dm of 10 μm or more and 30 μm or less as measured by a laser diffraction scattering method, and the composition has an excitation efficiency of 80% or more at 450 nm in an excitation spectrum. 【Chemistry 19】 【Chemistry 20】 【Chemistry 21】 [In chemical formulas (I') and (I''), n represents an integer of 2 or 3.]

12. A light emitting device comprising a composition containing the rare earth metal complex of claim 11 and an excitation light source.

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