JP7792764B2 - resin composition - Google Patents

Description

This disclosure relates to a resin composition.

Resin compositions containing rare earth complexes are being considered for use in a variety of applications, including as luminescent materials (e.g., Patent Documents 1 to 3).

Japanese Patent Application Laid-Open No. 2005-15564 JP 2016-4893 A JP 2017-15894 A

One aspect of the present invention aims to provide a new resin composition that is colored and has fluorescent properties.

One aspect of the present invention relates to a resin composition comprising a rare earth complex and a resin, wherein the rare earth complex comprises one rare earth ion and multiple ligands coordinated to the rare earth ion, at least one of the multiple ligands being a diketone ligand, and at least one of the multiple ligands having a chromophore that gives the rare earth complex a maximum absorption wavelength in the wavelength range of 400 to 600 nm. Because the resin composition of the present invention contains the rare earth complex, it is colored and has fluorescent properties.

The chromophore in the rare earth complex in the resin composition may have a pyrromethene skeleton or a merocyanine skeleton. In this case, the rare earth complex will be colored by visible light in the solid state or in solution, and the fluorescent properties of the rare earth complex will be even better.

At least one of the multiple ligands in the rare earth complex in the resin composition may be a phosphine oxide ligand having a chromophore.

The phosphine oxide ligand having a chromophore may be a ligand represented by the following formula (III): In this case, the rare earth complex is colored in the solid state or in solution under visible light, and the fluorescent property of the rare earth complex is further improved.

[In the formula,
^X11 and ^X12 each independently represent an aromatic group, a heteroaromatic group, a _C1-12 alkyl group, a _C3-12 alkenyl group, a _C3-12 cycloalkyl group, a C3-12 cycloalkenyl group, _{a C3-12 alkynyl} group, an aromatic oxy group, a heteroaromatic oxy group, a _{C1-12 alkyloxy group, a C3-12 alkenyloxy group, a C3-12 cycloalkyloxy} group, a _C3-12 cycloalkenyloxy group, or a _C3-12 alkynyloxy group;
^Z1 represents a group represented by the following formula (I) or (II).

(In formula (I),
n and m represent integers of 0 to 3,
^L1 represents a divalent organic group, an alkylene group, or a phenylene group containing a first bonding group, and the first bonding group is at least one selected from the group consisting of a carbonyl group (-C(=O)-), an ester group (-COO-), an amide group (-NH-C(=O)-), an ether group (-O-), and a thioether group (-S-);
R ¹¹ and R ¹² each independently represent a monovalent organic group containing a second bonding group, an alkyl group, a cyano group, a hydroxy group, a nitro group, a sulfo group, an amino group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group, or a halogen atom, and the second bonding group is at least one selected from the group consisting of a carbonyl group, an ester group, an ether group, and a thioether group;
When m is 2 or more, the multiple R ^11s may be the same or different, and when n is 2 or more, the multiple R ^12s may be the same or different.

(In formula (II),
p represents an integer of 0 to 4;
^R21 represents a monovalent organic group containing a third bonding group, an alkyl group, a cyano group, a hydroxy group, a nitro group, a sulfo group, an amino group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group, or a halogen atom, and the third bonding group is at least one selected from the group consisting of a carbonyl group, an ester group, an ether group, and a thioether group;
R ²² to R ²⁵ each independently represent a C _1-12 alkyl group;
^L3 represents an alkylene group or an arylene group;
When p is 2 or more, the multiple R ^21s may be the same or different.

The rare earth ions in the rare earth complex in the resin composition may be Eu ions or Tb ions. In this case, the fluorescent properties of the rare earth complex will be even better.

One aspect of the present invention provides a new resin composition that is colored and has fluorescent properties.

FIG. 1 shows the results of X-ray crystal structure analysis of (Z)-5-(2-((E) -1,3,3-trimethylindolin -2-ylidene)ethylidene)-1-(3-(diphenylphosphoryl)propyl)-4-methyl-2,6-dioxo-1,2,5,6-tetrahydropyridine-3-carbonitrile. FIG. 1 is a diagram showing the results of measuring the absorption wavelength of an Eu complex in an example. FIG. 1 is a diagram showing the measurement results of the excitation wavelength of a Eu complex in an example. FIG. 1 is a diagram showing the measurement results of the fluorescence wavelength of an Eu complex in an example. FIG. 10 is a diagram showing the results of measuring the absorption wavelength of a Eu complex in a comparative example. FIG. 10 is a diagram showing the measurement results of the excitation wavelength of a Eu complex in a comparative example. FIG. 10 is a diagram showing the measurement results of the fluorescence wavelength of a Eu complex in a comparative example. FIG. 2 is a diagram showing the results of measuring the absorption wavelength of a resin composition containing an Eu complex in an example. FIG. 1 is a diagram showing the measurement results of the fluorescence wavelength of a resin composition containing an Eu complex in an example.

Embodiments of the present invention are described below. However, the present invention is not limited to the following embodiments.

[Resin composition]
One embodiment of the present invention is a resin composition comprising a rare earth complex and a resin. The rare earth complex comprises one rare earth ion and a plurality of ligands coordinated to the rare earth ion, at least one of which is a diketone ligand, and at least one of which has a chromophore that gives the rare earth complex a maximum absorption wavelength in the wavelength range of 400 to 600 nm. Due to this characteristic, the rare earth complex is excited by light in the ultraviolet range and exhibits fluorescence in the visible range, and also exhibits a clear color in the visible range that does not include light in the ultraviolet range.

The resin composition according to this embodiment contains the rare earth complex, which is colored in the visible light range and has fluorescent properties. Furthermore, in resin compositions using this rare earth complex as a dye, there is no need to combine two compounds with different solubilities: a rare earth complex that is excited only in the ultraviolet range and an organic dye that absorbs in the visible range. This allows dyeing with a single component, making it easier to impart functionality.

Examples of resins include polymethyl (meth)acrylate, polycarbonate, polystyrene, polyurethane, polycarbonate, polyester, polyether, polyamide, polyvinyl chloride, silicone, epoxy resin, fluorine-based resin, polyethylene, and polypropylene. Resins may also be copolymers combining various monomers or mixtures of multiple resins.

The resin may be in the form of a film, sheet, fiber, fabric, paper, particles, pellets, or liquid.

The rare earth ions in the rare earth complexes are divalent, tetravalent, or trivalent rare earth ions, and may be divalent or trivalent. The rare earth ions may be ions of lanthanides such as La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. From the viewpoint of achieving even better fluorescence, the rare earth ions may be Eu ions or Tb ions.

At least one of the multiple ligands coordinated to the rare earth ion is a diketone ligand (β-diketone ligand). The presence of a diketone ligand allows the rare earth complex to have good fluorescent emission properties. The rare earth ion may also be coordinated with a ligand other than a diketone ligand. The ligand other than a diketone ligand may be, for example, a phosphine oxide ligand.

At least one of the ligands has a chromophore that gives the rare earth complex a maximum absorption wavelength in the wavelength range of 400 to 600 nm. This wavelength range may be, for example, 450 to 550 nm. Whether at least one of the ligands in the rare earth complex has the above-mentioned chromophore can be confirmed by measuring the absorbance of the rare earth complex and determining the maximum absorption wavelength of the rare earth complex. The absorbance of the rare earth complex can be measured under the conditions described in the Examples below.

From the perspective of further improving the fluorescence of the rare earth complex moiety, it is preferable that the chromophore have low absorption in the ultraviolet region with wavelengths less than 400 nm. The reason for this is that the process of fluorescence of a rare earth complex begins with the diketone ligand absorbing light in the ultraviolet region of 300 to 400 nm and becoming excited. From here, energy transfer occurs to the rare earth metal center, resulting in fluorescence of the rare earth complex. Therefore, it is necessary for the ligand containing the chromophore not to affect the fluorescence of the rare earth complex. Therefore, it is preferable that absorption at wavelengths less than 400 nm be as low as possible.

The molar absorption coefficient of the rare earth complex at the maximum absorption wavelength in the wavelength range of 400 to 600 nm may be, for example, 1,000 or more or 5,000 or more, or may be, for example, 200,000 or less.

The ligand having a chromophore may be a compound having a coordinating group that forms a coordinate bond with a rare earth ion and a group that contains a chromophore. The coordinating group of the ligand having a chromophore may be, for example, a phosphine oxide group or a β-diketonato group. The ligand having a chromophore may be a monodentate or bidentate ligand. The number of groups that contain a chromophore in one molecule may be, for example, 1 to 5, or may be 1. When one molecule contains multiple chromophores, the chromophores may be the same or different.

The chromophore may have a dye skeleton that exhibits sufficiently low absorption for light with wavelengths of less than 400 nm, for example, at least one skeleton selected from the group consisting of a pyrromethene skeleton (e.g., a boron dipyrromethene skeleton) and a merocyanine skeleton. Chromophores having the above skeletons exhibit sufficiently low absorption for light with wavelengths of less than 400 nm, which is necessary for exciting rare earth complexes. Therefore, rare earth complexes containing the above chromophores exhibit sufficient coloring properties and even superior fluorescent properties. Resin compositions containing such rare earth complexes are sufficiently colored and have even superior fluorescent properties.

The ligand having a chromophore containing a pyrromethene skeleton (boron dipyrromethene skeleton) may contain, for example, a group containing a chromophore represented by the following formula (I): When the chromophore represented by the following formula (I) is contained, the rare earth complex can have coloring properties and superior fluorescent properties.

In formula (I), * represents a bond. n and m each independently represent an integer from 0 to 3. n and m may be 0 to 2, 0 to 1, or 0.

R ¹¹ and R ¹² each independently represent a monovalent organic group containing a second bonding group, an alkyl group, a cyano group (-CN), a hydroxy group (-OH), or a halogen atom. The second bonding group may be at least one selected from the group consisting of a carbonyl group (-C(=O)-), an ester group (-COO-), an ether group (-O-), and a thioether group (-S-). The number of carbon atoms in the alkyl group represented by ^{R 11} and R ¹² may be, for example, 1 to 20, 1 to 15, 1 to 10, or 1 to 6. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. The halogen atom may be, for example, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. When m is 2 or greater, multiple R ^11s may be the same or different, and when n is 2 or greater, multiple R ^12s may be the same or different.

^L1 represents a divalent organic group, alkylene group, or phenylene group containing a first bonding group. The first bonding group may be at least one selected from the group consisting of a carbonyl group (-C(=O)-), an ester group (-COO-), an amide group (-NH-C(=O)-), an ether group (-O-), and a thioether group (-S-). ^L1 may be, for example, an alkylene group containing a first bonding group, an arylene group (e.g., a phenylene group) containing a first bonding group, or a group consisting of a first bonding group, an alkylene group, and an arylene group. The group represented by formula (I) may be bonded to the coordinating group via an ether group (-O-) or a thioether group (-S-).

The group represented by formula (I) may be, for example, a group represented by the following formula (Ia):

In formula (Ia), m, n, R ¹¹ , R ¹² and * are as defined above. o represents an integer of 0 to 4. o may be 0 to 3, 0 to 2, 0 to 1, or 0. R ¹³ represents a monovalent organic group containing a fourth linking group, an alkyl group, a cyano group, a hydroxy group, a nitro group, a sulfo group, an amino group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group, or a halogen atom. The fourth linking group may be at least one selected from the group consisting of a carbonyl group, an ester group, an ether group, and a thioether group. Specific examples of R ¹³ may be the same as those of R ¹¹ and R ¹² above.

^L2 represents an alkylene group or an arylene group. The number of carbon atoms of the alkylene group represented by ^L2 may be, for example, 1 to 12, 1 to 10, or 1 to 6. The alkylene group represented by ^L2 may be, for example, a methylene group ( _-CH2- ), an ethylene group, a propylene group, a butylene group, a pentylene group, or a hexylene group. The arylene group represented by ^L2 may be, for example, a phenylene group ( _-C6H4- ) or a _naphthylene group.

The group represented by formula (I) may be a group represented by the following formula (Ib) in which m, n, and o are 0 and ^L2 is a methylene group.

The ligand having a chromophore containing a merocyanine skeleton may contain, for example, a group containing a chromophore represented by the following formula (II): When the chromophore represented by the following formula (II) is contained, the rare earth complex can have coloring properties and superior fluorescent properties.

In formula (II), p represents an integer of 0 to 4. p may be 0 to 3, 0 to 2, 0 to 1, or 0. * represents a bond.

^R21 represents a monovalent organic group containing a third bonding group, an alkyl group, a cyano group, a hydroxy group, a nitro group, a sulfo group, an amino group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group, or a halogen atom. The third bonding group may be at least one selected from the group consisting of a carbonyl group, an ester group, an ether group, and a thioether group. When p is 2 or more, multiple ^R21s may be the same or different. The details of the substituent represented by ^R21 may be the same as those of the substituents represented by ^R11 and ^R12 .

R ²² to R ²⁵ each independently represent a C _1-12 alkyl group. The C _1-12 alkyl group represented by ^{R 22} to R ²⁵ is an alkyl group having 1 to 12 carbon atoms. R ²² to R ²⁵ may be, for example, a C _1-12 alkyl group having 1 to 12 carbon atoms, a C _1-6 alkyl group having 1 to 10 carbon atoms, or a C _1-6 alkyl group having 1 to 6 carbon atoms. The C _1-12 alkyl group may be, for example, a methyl group, ethyl group, propyl group, butyl group, pentyl group, or hexyl group.

^L3 represents an alkylene group or an arylene group. The details of the alkylene group and arylene group represented by ^L3 may be as described above.

The group represented by formula (II) may be a group represented by the following formula (IIa) in which p is 0, R ²² to R ²⁵ are methyl groups, and L ³ is an n-propylene group (—CH ₂ —CH ₂ —CH ₂ —). In this case, the rare earth complex can have coloring properties and superior fluorescent properties.

At least one of the plurality of ligands may be a phosphine oxide ligand having the above-mentioned chromophore. That is, at least one of the plurality of ligands in the rare earth complex may be a phosphine oxide ligand having a chromophore represented by the following formula (III). In this case, the rare earth complex can have coloring properties and superior fluorescent properties.

^Z1 represents a group containing the above chromophore, for example, a group represented by formula (I) or (II).

^X11 and ^X12 each independently represent an aromatic group, a heteroaromatic group, a _C1-12 alkyl group, a _C3-12 alkenyl group, a _C3-12 cycloalkyl group, a C3-12 cycloalkenyl group, _{a C3-12 alkynyl} group, an aromatic oxy group, a heteroaromatic oxy group, a _{C1-12 alkyloxy group, a C3-12 alkenyloxy group, a C3-12 cycloalkyloxy} group, a _C3-12 cycloalkenyloxy group, or a _C3-12 alkynyloxy group.

The aromatic group may be a phenyl group, naphthyl group, biphenyl group, etc. The heteroaromatic group may be a pyrrolyl group, furalyl group, indolyl group, thienyl group, etc. At least a portion of the hydrogen atoms bonded to these groups may be substituted with other groups, such as at least one substituent selected from the group consisting of a hydroxy group, a nitro group, an amino group, a sulfo group, a cyano group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group, and a halogen atom.

The C _1-12 alkyl group is an alkyl group having 1 to 12 carbon atoms. The C _1-12 alkyl group (C _n H _2n+1 : n = 1 to 12) may be linear or branched. At least one hydrogen atom of the _{C 1-12} alkyl group may be substituted with another group, or may be unsubstituted. The substituted C _1-12 alkyl group may be, for example, a linear or branched C 1-12 perhalogenated alkyl group such as a perfluoroalkyl group (C _n F _2n+1 : n = 1 to 12) or a perchloroalkyl group (C _n Cl _2n+1 : n = 1 to ₁₂ ). Examples of the substituted alkyl group include aralkyl groups such as a benzyl group and a phenethyl group, and perhalogenated aralkyl groups such as a perfluorobenzyl group.

The _C3-12 alkenyl group is an alkenyl group having 3 to 12 carbon atoms. The _C3-12 alkenyl group may be linear or branched. Examples of the _C3-12 alkenyl group include an allyl group and a butenyl group. At least one hydrogen atom of the _C3-12 alkenyl group may be substituted with another group, or may be unsubstituted. Examples of the substituted _C3-12 alkenyl group include linear or branched _C3-12 perhalogenated alkenyl groups, such as perfluoroalkenyl groups such as perfluorovinyl groups, perfluoroallyl groups, and perfluorobutenyl groups, and perchloroalkenyl groups.

A _C3-12 cycloalkyl group is a cycloalkyl group having 3 to 12 carbon atoms. A _C3-12 alkenyl group may be linear or branched. At least one hydrogen atom of a _C3-12 cycloalkyl group may be substituted with another group, or may be unsubstituted. Examples of substituted _C3-12 cycloalkyl groups include C3-12 perhalogenated cycloalkyl groups such as perfluorocycloalkyl groups ( _{CnF2n -1} : n = 3 to 12) and perchlorocycloalkyl groups ( _{CnCl2n -1} : n = 3 to ₁₂ ).

The _C3-12 cycloalkenyl group is a cycloalkenyl group having 3 to 12 carbon atoms. Examples of the _C3-12 cycloalkenyl group include a cyclopentenyl group and a cyclohexenyl group. At least one hydrogen atom of the _C3-12 cycloalkenyl group may be substituted with another group, or may be unsubstituted. The _C3-12 cycloalkenyl group having a substituent may be, for example, a _C3-12 perhalogenated cycloalkenyl group such as a perfluorocycloalkenyl group or a perchlorocycloalkenyl group.

A _C3-12 alkynyl group is an alkynyl group having a carbon number of 3 to 12. At least one hydrogen atom of the _C3-12 alkynyl group may be substituted with another group, or may be unsubstituted.

An aromatic oxy group is a group formed by bonding an oxy group (—O—) to the above aromatic group. A heteroaromatic oxy group is a group formed by bonding an oxy group to the above heteroaromatic group. _{A C1-12} alkyloxy group is a group formed by bonding an oxy group to the above _C1-12 alkyl group. A _C3-12 alkenyloxy group is a group formed by bonding an oxy group to the above _C3-12 alkenyl group. A _C3-12 cycloalkyloxy group is a group formed by bonding an oxy group to the above _C3-12 cycloalkyl group. A _C3-12 cycloalkenyloxy group is a group formed by bonding an oxy group to the above _C3-12 cycloalkenyl group. A _C3-12 alkynyloxy group is a group formed by bonding an oxy group to the above _C3-12 alkynyl group.

The above groups represented by X ¹¹ and X ¹² may have one or more —COO— and —CO— inserted between the C—C single bonds at any position.

X ¹¹ and X ¹² may each independently represent an aromatic group or a phenyl group.

Specifically, the ligand having a chromophore may be a compound represented by the following formula (A-1) or (A-2): In this case, the rare earth complex can have coloring properties and superior fluorescent properties.

The rare earth complex according to this embodiment may be, for example, a complex represented by the following formula (IV).

In the formula, Ln represents a rare earth element, n1 represents an integer from 2 to 4, n2 represents an integer from 2 to 4, and n3 represents an integer from 0 to 2.

X ²¹ , X ²² and X ²³ each independently represent an aromatic group, a heteroaromatic group, a C _1-12 alkyl group, a C _3-12 alkenyl group, a C _3-12 cycloalkyl group, a C _3-12 cycloalkenyl group, a C _3-12 alkynyl group, an aromatic oxy group, a heteroaromatic oxy group, a C _1-12 alkyloxy group, a C _3-12 alkenyloxy group, a C _{3-12 cycloalkyloxy group, a C 3-12 cycloalkenyloxy} group, a C _3-12 alkynyloxy group, or a group containing a chromophore.

^Y1 and ^Y2 each independently represent an aromatic group, a heteroaromatic group, a _C1-12 alkyl group, a _C3-12 alkenyl group, a _C3-12 cycloalkyl group, a _C3-12 cycloalkenyl group, a _C3-12 alkynyl group, or a group containing a chromophore. Examples of heteroaromatic groups include a thiophenyl group.

In the _C1-12 alkyl group, _C3-12 alkenyl group, _C3-12 cycloalkyl group, and _C3-12 cycloalkenyl group represented by ^X21 , ^X22 , ^X23 , ^Y1 , and ^Y2 , some or all of the hydrogen atoms may be substituted with halogen atoms, for example, fluorine atoms or chlorine atoms.

Specific examples of the substituents represented by X ²¹ , X ²² , X ²³ , Y ¹ and Y ² may be as described above.

^Y3 represents a hydrogen atom or a deuterium atom.

When n3 is 0, at least one of ^Y1 and ^Y2 is a group containing a chromophore. When n3 is 1 or 2, at least one of ^X21 , ^X22 , ^X23 , ^Y1 and ^Y2 is a group containing a chromophore.

Rare earth complexes can be incorporated into resin compositions using a variety of methods, including: immersing a film, fiber, or particle-like object in a solution containing the rare earth complex and drying it; dissolving the rare earth complex and resin in an organic solvent and applying it to a substrate using various coating techniques; dyeing by adding a dye solution to a resin dispersion; or directly adding the rare earth complex when melting and kneading resin pellets.

The content of the rare earth complex in the resin composition is selected appropriately depending on the purpose of the resin composition. For example, the content of the rare earth complex in the resin composition may be 0.001 parts by mass or more, or 0.01 parts by mass or more, and may be 0.5 parts by mass or less, or 0.4 parts by mass or less, per 1 part by mass of resin.

The resin content may be adjusted appropriately depending on the application, required properties, etc. of the resin composition. The resin content in the resin composition may be 50% by mass or more, or 60% by mass or more, and may be 99.9% by mass or less, or 99% by mass or less, based on the total mass of the resin composition.

The resin composition may contain inorganic materials within and/or within the resin. Examples of inorganic materials include ceramic fillers such as silica, alumina, silicon nitride, and boron nitride, as well as metal particles such as iron, nickel, and cobalt.

The resin composition may further contain other components. Examples of other components include additives such as antioxidants, UV absorbers, light stabilizers, flame retardants, lubricants, plasticizers, antistatic agents, thixotropic agents, surfactants, thickeners, inorganic fillers, and pigments.

The resin composition can be used, for example, for dyeing plastic raw materials, coating materials such as paints, printing inks, and paint materials, writing implements such as paints and pens, toys, resins for 3D printers, agricultural films, display plates for safety, disaster prevention, and crime prevention products, fluorescent labeling agents for biomolecules such as proteins and nucleic acids, and labeling agents for immunoassay methods.

[Method for producing resin composition]
The resin composition can be produced by a method including a step of mixing a resin and a rare earth complex.

Rare earth complexes can be produced by a method including the step of reacting a complex precursor containing a rare earth ion with a ligand having a chromophore to coordinate the ligand having a chromophore to the rare earth ion. The reaction may be carried out under heating. Specific examples of reaction conditions may be as described in the examples below.

Ligands having chromophores can be prepared according to conventional synthetic methods. Examples of methods for synthesizing ligands having chromophores are shown in the examples below.

For example, a ligand compound having a chromophore (compound B) represented by formula (B) can be synthesized according to the following reaction scheme.

Compound B can be obtained, for example, by a method including the steps of reacting a compound represented by formula (1) (compound 1), ethyl cyanoacetate, a compound represented by formula (2) (compound 2), and a base to obtain a compound represented by formula (3) (compound 3), and reacting compound 3, a compound represented by formula (4) (compound 4), and acetic anhydride to obtain compound B.

In the formula, ^X31 and ^X32 have the same meaning as ^X21 and ^X22 in formula (IV). q has the same meaning as p in formula (II). ^R31 to ^R35 have the same meaning as ^R21 to ^R25 in formula (II). ^R36 represents a hydrocarbon group such as an alkyl group. ^R31 may be, for example, a methyl group or an ethyl group.

Compound 1 can be produced according to conventional synthesis methods. Examples of synthesis methods for Compound 1 are described in the Examples below.

The reaction to obtain compound 3 is usually carried out in the presence of a base. The base may be, for example, piperidine, pyridine, triethylamine, and/or hexamethyleneimine. The reaction to obtain compound 3 may be carried out in the presence of a solvent. Examples of solvents include ethanol, dichloromethane, tetrachloroethane, carbon tetrachloride, diethyl ether, tetrahydrofuran, benzene, and toluene. The reaction to obtain compound 3 may be carried out with heating. After completion of the reaction, post-treatment may be carried out using a conventional method. Specific reaction conditions are as described in the Examples below.

Compound 3 is useful as a precursor compound of compound B. Another embodiment of the present invention is a compound represented by formula (3). In the compound represented by formula (3), R ³⁵ may be a C _1-10 alkyl group, a C _1-6 alkyl group, or a methyl group. L ⁴ may be an alkylene group, for example, an n-propylene group. The compound represented by formula (3) may specifically be a compound represented by the following formula (3-1).

The present invention will be described in more detail below based on examples, but the present invention is not limited to the following examples. In the following description, "TTA" is an abbreviation for thenoyltrifluoroacetone, and "TOPO" is an abbreviation for trioctylphosphine oxide.

<Ligand synthesis 1>
Synthesis Example 1-1: Synthesis of (3-aminopropyl)diphenylphosphine oxide

To 3.8 mol of 3-chloropropylamine hydrochloride, 10 mL of dried benzene and 5 mL of chloroform were added. Then, 8.3 mmol of triethylamine solution (dissolved in 3.3 mL of dried benzene and 1.7 mL of chloroform) was added. After stirring for 20 minutes, the mixture was cooled to 2-4°C, and 3.8 mmol of diphenylchlorophosphine oxide solution (dissolved in 6.6 mL of dried benzene and 3.4 mL of chloroform) was added. After stirring for 1 hour, the mixture was heated to reflux and stirred for an additional 1 hour. The mixture was cooled to room temperature, and the solvent was distilled off. The residue was dissolved in 50 mL of chloroform and extracted with 100 mL of distilled water. The organic layer was removed, and aqueous sodium hydroxide solution was added until the pH reached 10, followed by extraction with 100 mL of chloroform. The chloroform was distilled off, yielding the target compound represented by formula (1-1). The yield was 75%.

Synthesis Example 1-2: Synthesis of 1-(3- ( diphenylphosphoryl)propyl)-6-hydroxy-4-methyl-2-oxo-1,2-dihydropyridine-3-carbonitrile

1 mmol of the compound represented by formula (1-1) above was added with 1 mmol of ethyl cyanoacetate and 5 mL of ethanol, and the mixture was stirred at room temperature for 6 hours. Then, 1.1 mmmol of ethyl acetoacetate and 0.1 mL of piperidine were added, and the mixture was stirred at 110°C. After cooling to room temperature, the solvent was distilled off, and 10 mL of 10% hydrochloric acid was added. The resulting precipitate was collected by filtration, washed with distilled water and hexane, and dried to obtain the compound represented by formula (1-2) above as the target product. The yield was 65%.

Synthesis Example 1-3: Synthesis of (Z)-5-(2-((E) -1,3,3-trimethylindolin -2-ylidene)ethylidene)-1-(3-(diphenylphosphoryl)propyl)-4-methyl-2,6-dioxo-1,2,5,6-tetrahydropyridine-3-carbonitrile

To 1 mmol of the compound represented by formula (1-2) above, 1.05 mmol of 2-(1,3,3-trimethylindolin-2-ylidene)acetaldehyde and 3 mL of acetic anhydride were added, and the mixture was refluxed for 15 minutes. The resulting precipitate was collected by filtration, washed with hexane, and dried to obtain the compound represented by formula (1-3) above. The yield was 82%.
^P -NMR: 32.4 ppm (solvent: chloroform)

The fact that the compound represented by formula (1-3) above was obtained was confirmed by X-ray crystal structure analysis. The results of the X-ray crystal structure analysis are shown in Figure 1. Measurements were performed using a D8 VENTURE, and analysis was performed using a VESTA.

<Synthesis of Rare Earth Complexes in Examples>
Synthesis Example 1-4: Synthesis of Eu complex of the example

To 1 mmol of the compound represented by the above formula (1-3), ₁ mmol of Eu(TTA) 3.2H ₂ O and 10 mL of isopropanol were added, and the mixture was refluxed at 80° C. for 4 hours. The solvent was distilled off to obtain the target Eu complex of this example. The yield was 87%.
³¹ P-NMR: -93.1 ppm (solvent: chloroform), nanoESI-MS: 1414.1064 (C ₅₉ H ₄₆ O ₉ N ₃ F ₉ PS ₃ Eu+Na ⁺ , theoretical value: 1414.1095)

<Ligand synthesis 2>
Synthesis Example 2-1: Synthesis of 4-(5,5-difluoro-5H-414,514-dipyrrolo[1,2-c:2′,1′-f][1,3,2]diazaborin-10-yl)benzyl diphenylphosphinate

1.5 mmol of (4-(5,5-difluoro-5H-414,514-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborinine-10-yl)phenyl)methanol was dissolved in 30 mL of dichloromethane, and 1.0 mmol of chlorodiphenylphosphine oxide and 3.0 mmol of pyridine were added, followed by stirring at 40°C for 8 hours. The solvent was distilled off, and the residue was purified by column chromatography to obtain the target product. The yield was 63%.

<Synthesis of Rare Earth Complex of Comparative Example>
Comparative Synthesis Example: Synthesis of Eu(TTA) ₃ ·(TOPO) ₂

1 mmol of Eu(TTA) ₃ ·2H ₂ O and 2 mmol of TOPO (trioctylphosphine oxide) were added to 10 mL of ethanol and stirred at room temperature. The solvent was distilled off to obtain the target product. The product was recrystallized using ethanol and distilled water for purification. This resulted in the Eu complex (Eu(TTA) ₃ ·(TOPO) ₂ ) of the comparative example. The yield was 78%.
³¹ P-NMR: -49.8 ppm (solvent: chloroform), nanoESI-MS: 1611.6082 (C ₇₂ H ₁₁₄ O ₈ F ₉ P ₂ S ₃ Eu + Na ⁺ , theoretical value: 1611.6117)

Evaluation 0.35 mmol of the Eu complex was dissolved in 10 mL of chloroform, and the solution was diluted 1000 times to prepare a measurement sample.

Absorption wavelength measurements were performed using a Jasco V-650 spectrophotometer, and absorbance was measured. Excitation and fluorescence wavelength measurements were performed using a Hitachi High-Tech F-7000 with a long-pass filter: LPF-39, and photoluminescence intensity (PL intensity) was measured. A square cell (10 mm square, quartz) was used for measurements. The monitor wavelength for excitation wavelength measurements was set to 615 nm. The excitation wavelength for fluorescence wavelength measurements was set to 350 nm.

The measurement results for the absorption wavelength, excitation wavelength, and fluorescence wavelength of the Eu complex of the example (Eu complex represented by formula (1-4) above) are shown in Figures 2 to 4. The measurement results for the absorption wavelength, excitation wavelength, and fluorescence wavelength of the Eu complex of the comparative example are shown in Figures 5 to 7.

<Preparation and Evaluation of Colored Resin Compositions>
A resin solution was prepared by dissolving 2.0 g of general-purpose polystyrene resin and 0.050 g of the compound represented by formula (1-4) in 8.0 g of chloroform. The resin solution was applied to a glass plate using a bar coater, and the solvent was air-dried to create a 10 μm-thick colored resin film. Absorption wavelength and fluorescence wavelength measurements were performed on this film. A Jasco V-650 spectrophotometer was used for absorption wavelength measurements. An Otsuka Electronics MCPD9800 was used for fluorescence wavelength measurements, with an excitation wavelength of 365 nm. The results of the absorption wavelength measurements and fluorescence wavelength measurements are shown in Figures 8 and 9, respectively.

Claims (2)

A resin composition comprising a rare earth complex and a resin,
the rare earth complex includes one rare earth ion and a plurality of ligands coordinated to the rare earth ion;
at least one of the plurality of ligands is a diketone ligand;
at least one of the plurality of ligands is a phosphine oxide ligand having a chromophore that gives the rare earth complex a maximum absorption wavelength in a wavelength region of 400 to 600 nm;
A resin composition, wherein the phosphine oxide ligand having a chromophore is a ligand represented by the following formula (III):

[In the formula,
^X11 and ^X12 each independently represent an aromatic group, a heteroaromatic group, a _C1-12 alkyl group, a _C3-12 alkenyl group, a _C3-12 cycloalkyl group, a C3-12 cycloalkenyl group, _{a C3-12 alkynyl} group, an aromatic oxy group (aromatic group -O-) , a heteroaromatic oxy group (heteroaromatic group -O-) , a _{C1-12 alkyloxy group, a C3-12 alkenyloxy} group, a _{C3-12 cycloalkyloxy group, a C3-12 cycloalkenyloxy} group, or a _C3-12 alkynyloxy group;
^Z1 represents a group represented by the following formula (Ib) or (IIa), in which * represents a bond to the phosphorus atom.

The resin composition according to claim 1, wherein the rare earth ions are Eu ions or Tb ions.