Color conversion composition, color conversion member, and light source unit, display and lighting device that include the same

Abstract

To achieve both improved color reproducibility and reduced thickness in a color conversion member used for a light source, display, or lighting, and in particular, to provide a thin color conversion member capable of achieving both high color purity emission and high-efficiency emission.SOLUTION: A color conversion composition comprises at least one kind of luminescent material and a binder resin, where the at least one kind of organic luminescent material includes a compound having a structure represented by general formula (1), where n represents a natural number equal to or greater than 2, and L represents a direct bond or an n-valent linking group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a color-converting composition, a color-converting member, and a light source unit, a display, and a lighting device each including the same. [Background technology]

[0002] There is active research into applying multi-color technology using color conversion methods to liquid crystal displays, organic EL displays, lighting devices, etc. Color conversion refers to converting light emitted from an illuminant into light with a longer wavelength, such as converting blue light into green or red light.

[0003] By forming this composition with color conversion functionality into a sheet and combining it with, for example, a blue light source, it is possible to obtain the three primary colors of blue, green, and red from the blue light source, i.e., white light. By using a white light source that combines such a blue light source with a sheet with color conversion functionality as a light source unit such as a backlight unit, and combining this light source unit with a liquid crystal driver and a color filter, it is possible to produce a full-color display. Furthermore, a white light source that combines a blue light source with a sheet with color conversion functionality can also be used directly as a white light source for LED lighting, etc.

[0004] Issues facing displays that use a color conversion method include improving color reproducibility and durability. To improve color reproducibility, it is effective to narrow the half-width of the blue, green, and red emission spectra of the light source unit and increase the color purity of each of the blue, green, and red colors. To solve this problem, for example, a color conversion material containing an organic fluorescent material that emits light with high color purity has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-105171 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, displays have become thinner, and there is a demand for even thinner color conversion components. While the technology described in Patent Document 1 certainly makes it possible to obtain color conversion compositions with excellent color reproducibility, there has been a lack of technology to achieve high color conversion properties in a thin film state. In particular, there has been a lack of technology to maintain high light emission efficiency and high dispersibility in a thin film state.

[0007] The problem that the present invention aims to solve is to achieve both improved color reproducibility and thinness in color conversion components used in displays and lighting devices, and in particular, to provide a thin color conversion component that achieves both high color purity and high efficiency light emission. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, the present invention has the configuration described in any one of the following [1] to

[13] . [1] A color-changing composition comprising at least one organic light-emitting material and a binder resin, wherein the at least one organic light-emitting material contains a compound having a structure represented by general formula (1).

[0009] [ka]

[0010] n is a natural number greater than or equal to 2. L represents a direct bond or an n-valent linking group. D is a partial structure represented by general formula (2) or (3), and n Ds may be the same or different.

[0011] [ka]

[0012] In general formula (2) or (3), ring Za, ring Zb, and ring Zc are each independently a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl ring having 4 to 30 ring carbon atoms. 1 and Z 2 are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom. 1 When R is NRa, the substituent R may be bonded to the ring Z or the ring Z to form a ring. 2 When R is NRa, the substituent R may be bonded to the ring Z or the ring Zc to form a ring. In the general formula (2), E is a boron atom, a phosphorus atom, SiR (a silicon atom having a substituent R) or P=O. In the general formula (3), E 1 and E 2 are each independently BRa (a boron atom having a substituent Ra), PRa (a phosphorus atom having a substituent Ra), SiRa2 (a silicon atom having two substituents Ra), P(=O)Ra2 (a phosphine oxide having two substituents Ra) or P(=S)Ra2 (a phosphine sulfide having two substituents Ra), C=O (a carbonyl group), S(=O) or S(=O)2. E 1 When is BRa, PRa, SiRa2, P(=O)Ra2 or P(=S)Ra2, the substituent Ra may be bonded to ring Za or ring Zb to form a ring. 2is BRa, PRa, SiRa2, P(=O)Ra2, or P(=S)Ra2, the substituent Ra may bond with ring Za or ring Zc to form a ring. The substituents Ra are each independently selected from a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, a halogen atom, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, an ester group, a carbamoyl group, an amide group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, an amino group, an imino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, a phosphine oxide group, and a fused ring or an aliphatic ring formed between adjacent substituents. Furthermore, the substituent Ra may be further substituted with a selected substituent as described above, and these substituents may be further substituted with a selected substituent as described above. However, in the general formula (2) or (3), the ring Za, ring Zb, ring Zc, and Z 1 , Z 2 , E 1 , E 2 and the substituents Ra substituted thereon form a bond with L on at least one element forming any one of them. In addition, when at least one of the n partial structures D in the general formula (1) is represented by the general formula (2), at least one of the partial structures D represented by the general formula (2) has Z 1 and Z 2 At least one of them is NRa.) [2] E in the general formula (2) is a boron atom, and E in the general formula (3) 1 and E 2 The color-changing composition according to [1], wherein [3] Z in the general formula (2) 1 and Z 2 The color-changing composition according to [1] or [2], wherein [4] The color-changing composition according to any one of [1] to [3], wherein all of the n Ds are represented by general formula (2). [5] The color-changing composition according to any one of [1] to [4], wherein L represents a direct bond. [6] The color-changing composition according to any one of [1] to [4], wherein L is an n-valent linking group containing an aryl ring having 3 to 30 ring members or a heteroaryl ring having 3 to 30 ring members. [7] The color-changing composition according to any one of [1] to [6], wherein n is 2 or 3. [8] A cured product of the color-changing composition according to any one of [1] to [7]. [9] A color-changing member comprising the color-changing composition according to any one of [1] to [7] or a cured product thereof.

[10] The color conversion member according to [9], which has an oxygen barrier layer.

[11] A light source unit comprising a light source and the color conversion member according to [9] or

[10] .

[12] A display including the light source unit according to

[11] .

[13] A lighting device comprising the light source unit according to

[11] . [Effects of the Invention]

[0013] The color-converting composition of the present invention and the color-converting member using the same can achieve high color reproducibility and high efficiency in a thin film state. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic cross-sectional view showing an example of a color conversion member of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of a color conversion member of the present invention. [Figure 3] FIG. 2 is a schematic cross-sectional view showing an example of a color conversion member of the present invention. [Figure 4] FIG. 2 is a schematic cross-sectional view showing an example of a color conversion member of the present invention. [Figure 5] FIG. 2 is a schematic cross-sectional view showing an example of a color conversion member of the present invention. [Figure 6] FIG. 2 is a schematic cross-sectional view showing an example of a color conversion member of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] The following describes in detail the embodiments of the present invention, but the present invention is not limited to the following embodiments and can be modified in various ways depending on the purpose and application. Furthermore, the matters cited as preferred examples in specific embodiments and embodiments can also be applied to other embodiments and embodiments.

[0016] <Light-emitting materials> The color-changing composition according to the embodiment of the present invention contains at least one luminescent material, which, when irradiated with a certain light, emits light of a wavelength different from that of the light.

[0017] Examples of luminescent materials include inorganic phosphors, fluorescent pigments, fluorescent dyes, quantum dots, etc. Two or more of these may be contained. To achieve highly efficient color conversion, materials exhibiting luminescent properties with high quantum yield are preferred, and quantum dots and organic luminescent materials are preferred. Furthermore, from the viewpoints of uniform dispersion, reduced usage, and reduced environmental impact, it is more preferred to use organic luminescent materials.

[0018] Examples of organic light-emitting materials include: Compounds having a fused aryl ring, such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene, and derivatives thereof; Compounds having a heteroaryl ring, such as furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, and pyrrolopyridine, and derivatives thereof; Borane derivatives; stilbene derivatives such as 1,4-distyrylbenzene, 4,4'-bis(2-(4-diphenylaminophenyl)ethenyl)biphenyl, and 4,4'-bis(N-(stilben-4-yl)-N-phenylamino)stilbene; Aromatic acetylene derivatives, tetraphenylbutadiene derivatives, aldazine derivatives, pyrromethene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives; Coumarin derivatives such as Coumarin 6, Coumarin 7, and Coumarin 153; Azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, and triazole, and their metal complexes; cyanine compounds such as indocyanine green; Xanthene and thioxanthene compounds such as fluorescein, eosin, and rhodamine; Polyphenylene compounds, naphthalimide derivatives, phthalocyanine derivatives and their metal complexes, porphyrin derivatives and their metal complexes; oxazine compounds such as Nile Red and Nile Blue; Helicene-based compounds; Aromatic amine derivatives such as N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine; and Organometallic complex compounds such as iridium (Ir), ruthenium (Ru), rhodium (Rh), palladium (Pd), platinum (Pt), osmium (Os), europium (Eu) and rhenium (Re); The following are suitable examples.

[0019] The organic light-emitting material may be a fluorescent material or a phosphorescent material, but in order to achieve high color purity, a fluorescent material is preferred.

[0020] As described above, in order to improve color reproducibility, it is preferable that the half-value width of the emission spectrum of each of the blue, green, and red colors is small. Therefore, the half-value width of the emission spectrum at the emission peak wavelength of the light-emitting material is preferably 60 nm or less, and more preferably 50 nm or less.

[0021] In the color-changing composition according to the embodiment of the present invention, the light-emitting material contains a compound having a structure represented by general formula (1).

[0022] [ka]

[0023] In general formula (1), n ​​is a natural number of 2 or more. Also, in general formula (1), L represents a direct bond or an n-valent linking group. Furthermore, in general formula (1), D represents a partial structure represented by general formula (2) or (3), and the n Ds may be the same or different.

[0024] [ka]

[0025] In general formula (2) and general formula (3), ring Za, ring Zb, and ring Zc are each independently a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl ring having 4 to 30 ring carbon atoms.

[0026] In general formula (2), Z 1 and Z 2 are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom. 1 When R is NRa, the substituent R may be bonded to the ring Z or the ring Z to form a ring. 2 When is NRa, the substituent Ra may be bonded to ring Za or ring Zc to form a ring.

[0027] In the general formula (2), E is a boron atom, a phosphorus atom, SiRa (a silicon atom having a substituent Ra), or P═O.

[0028] In general formula (3), E 1 and E 2are each independently BRa (a boron atom having a substituent Ra), PRa (a phosphorus atom having a substituent Ra), SiRa2 (a silicon atom having two substituents Ra), P(=O)Ra2 (a phosphine oxide having two substituents Ra) or P(=S)Ra2 (a phosphine sulfide having two substituents Ra), C=O (a carbonyl group), S(=O) or S(=O)2. E 1 When is BRa, PRa, SiRa2, P(=O)Ra2 or P(=S)Ra2, the substituent Ra may be bonded to ring Za or ring Zb to form a ring. 2 When is BRa, PRa, SiRa2, P(=O)Ra2 or P(=S)Ra2, the substituent Ra may be bonded to ring Za or ring Zc to form a ring.

[0029] The substituents R are each independently selected from a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an arylthioether group, a halogen atom, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an oxycarbonyl group, an ester group, a carbamoyl group, an amide group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, an amino group, an imino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, a phosphine oxide group, and a fused ring or an aliphatic ring formed between adjacent substituents. The substituents R may be further substituted with selected substituents, and these substituents may be further substituted with selected substituents.

[0030] However, in the general formula (2) or (3), the ring Za, ring Zb, ring Zc, and Z 1 , Z 2 , E 1 , E 2 and the substituents Ra substituted thereon form a bond with L on at least one element forming any one of them.

[0031] In addition, when at least one of the n partial structures D in the general formula (1) is represented by the general formula (2), at least one of the partial structures D represented by the general formula (2) has Z 1 and Z 2 At least one of them is NRa.

[0032] In all of the above groups, hydrogen may be replaced with deuterium. The same applies to the compounds or partial structures thereof described below.

[0033] In the following description, for example, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms means an aryl group having 6 to 40 carbon atoms, including the number of carbon atoms contained in a substituent substituted on the aryl group. The same applies to other substituents that specify the number of carbon atoms.

[0034] The term "unsubstituted" in the context of "substituted or unsubstituted" means that a hydrogen atom or a deuterium atom has been substituted. The same applies to the term "substituted or unsubstituted" in the compounds or partial structures thereof described below.

[0035] In all of the above groups, examples of the substituent when substituted include an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, a halogen atom, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, an ester group, a carbamoyl group, an amide group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, an imino group, an amino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, or a phosphine oxide group. These substituents may be further substituted with the above-mentioned substituents.

[0036] The alkyl group refers to a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group, which may or may not have a substituent. When substituted, the additional substituent is not particularly limited, and examples thereof include an alkyl group, a halogen, an aryl group, and a heteroaryl group, which also applies to the following description. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably in the range of 1 to 20, more preferably 1 to 8, in terms of availability and cost.

[0037] The cycloalkyl group refers to a saturated alicyclic hydrocarbon group, such as a cyclopropyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, or the like, which may or may not have a substituent. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably in the range of 3 to 20.

[0038] The heterocyclic group refers to an aliphatic ring having atoms other than carbon atoms in the ring, such as a pyran ring, a piperidine ring, or a cyclic amide, which may or may not have a substituent. The number of carbon atoms in the heterocyclic group is not particularly limited, but is preferably in the range of 2 to 20.

[0039] The alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as a vinyl group, an allyl group, or a butadienyl group, which may or may not have a substituent. The number of carbon atoms in the alkenyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0040] The cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond, such as a cyclopentenyl group, a cyclopentadienyl group, or a cyclohexenyl group, which may or may not have a substituent. The number of carbon atoms in the cycloalkenyl group is not particularly limited, but is preferably in the range of 3 to 20.

[0041] The alkynyl group refers to an unsaturated aliphatic hydrocarbon group containing a triple bond, such as an ethynyl group, which may or may not have a substituent. The number of carbon atoms in the alkynyl group is not particularly limited, but is preferably in the range of 2 to 20.

[0042] The alkoxy group refers to a functional group in which an aliphatic hydrocarbon group is bonded via an ether bond, such as a methoxy group, an ethoxy group, or a propoxy group, and this aliphatic hydrocarbon group may or may not have a substituent. The number of carbon atoms in the alkoxy group is not particularly limited, but is preferably in the range of 1 to 20.

[0043] An alkylthio group is an alkoxy group in which the oxygen atom of the ether bond is replaced with a sulfur atom. The hydrocarbon group of the alkylthio group may or may not have a substituent. The number of carbon atoms in the alkylthio group is not particularly limited, but is preferably in the range of 1 to 20.

[0044] The aryl ether group refers to a functional group, such as a phenoxy group, to which an aromatic hydrocarbon group is bonded via an ether bond, and the aromatic hydrocarbon group may or may not have a substituent. The number of carbon atoms in the aryl ether group is not particularly limited, but is preferably in the range of 6 to 40.

[0045] An aryl thioether group is an aryl ether group in which the oxygen atom of the ether bond is substituted with a sulfur atom. The aromatic hydrocarbon group in the aryl thioether group may or may not have a substituent. The number of carbon atoms in the aryl thioether group is not particularly limited, but is preferably in the range of 6 to 40.

[0046] The aryl group refers to an aromatic hydrocarbon group such as a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthryl group, an anthracenyl group, a benzophenanthryl group, a benzanthracenyl group, a chrysenyl group, a pyrenyl group, a fluoranthenyl group, a triphenylenyl group, a benzofluoranthenyl group, a dibenzoanthracenyl group, a perylenyl group, or a helicenyl group. Among these, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, an anthracenyl group, a pyrenyl group, a fluoranthenyl group, or a triphenylenyl group is preferred. The aryl group may or may not have a substituent. The number of carbon atoms in the aryl group is not particularly limited, but is preferably in the range of 6 to 40, more preferably 6 to 30.

[0047] The aryl group is preferably a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, or an anthracenyl group, more preferably a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group, even more preferably a phenyl group, a biphenyl group, or a terphenyl group, and particularly preferably a phenyl group.

[0048] When each of the substituents is further substituted with an aryl group, the aryl group is preferably a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, or an anthracenyl group, more preferably a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group, and particularly preferably a phenyl group.

[0049] Examples of heteroaryl groups include pyridyl, furanyl, thienyl, quinolinyl, isoquinolinyl, pyrazinyl, pyrimidyl, pyridazinyl, triazinyl, naphthyridinyl, cinnolinyl, phthalazinyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothienyl, indolyl, dibenzofuranyl, dibenzothienyl, carbazolyl, and benzocarbazolyl. It refers to a cyclic aromatic group having one or more atoms other than carbon in the ring, such as a carbolinyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a dihydroindenocarbazolyl group, a benzoquinolinyl group, an acridinyl group, a dibenzoacridinyl group, a benzimidazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, or a phenanthrolinyl group. Here, the naphthyridinyl group refers to a 1,5-naphthyridinyl group, a 1,6-naphthyridinyl group, a 1,7-naphthyridinyl group, a 1,8-naphthyridinyl group, a 2,6-naphthyridinyl group, or a 2,7-naphthyridinyl group. The heteroaryl group may or may not have a substituent. The number of carbon atoms in the heteroaryl group is not particularly limited, but is preferably in the range of 2 or more and 40 or less, and more preferably 2 or more and 30 or less.

[0050] As the heteroaryl group, a pyridyl group, a furanyl group, a thienyl group, a quinolinyl group, a pyrimidyl group, a triazinyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a dibenzofuranyl group, a dibenzothienyl group, a carbazolyl group, a benzimidazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, or a phenanthrolinyl group is preferred, and a pyridyl group, a furanyl group, a thienyl group, or a quinolinyl group is more preferred, and a pyridyl group is particularly preferred.

[0051] When each substituent is further substituted with a heteroaryl group, the heteroaryl group is preferably a pyridyl group, a furanyl group, a thienyl group, a quinolinyl group, a pyrimidyl group, a triazinyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a dibenzofuranyl group, a dibenzothienyl group, a carbazolyl group, a benzimidazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, or a phenanthrolinyl group, more preferably a pyridyl group, a furanyl group, a thienyl group, or a quinolinyl group, and particularly preferably a pyridyl group.

[0052] Halogen refers to an atom selected from fluorine, chlorine, bromine and iodine.

[0053] The carbonyl group, carboxy group, oxycarbonyl group, ester group, carbamoyl group, amide group, and imino group may or may not have a substituent. Examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, and a heteroaryl group, and these substituents may be further substituted.

[0054] The sulfonyl group, sulfonate group, and sulfonamide group are each represented by -S(=O)R 10 , -S(=O)2OR 10 , -S(=O)2NR 10 R 11 is a group represented by R 10 , R 11 is hydrogen or selected from the same group as the substituents when substituted as described above.

[0055] The amino group is a substituted or unsubstituted amino group. In the case of substitution, examples of the substituent include an aryl group, a heteroaryl group, a linear alkyl group, and a branched alkyl group. Preferred aryl and heteroaryl groups are a phenyl group, a naphthyl group, a pyridyl group, and a quinolinyl group. These substituents may be further substituted. The number of carbon atoms is not particularly limited, but is preferably in the range of 2 to 50, more preferably 6 to 40, and particularly preferably 6 to 30.

[0056] The silyl group refers to, for example, alkylsilyl groups such as trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, propyldimethylsilyl, and vinyldimethylsilyl, and arylsilyl groups such as phenyldimethylsilyl, tert-butyldiphenylsilyl, triphenylsilyl, and trinaphthylsilyl. The substituent on the silicon atom may be further substituted. The number of carbon atoms in the silyl group is not particularly limited, but is preferably in the range of 1 to 30.

[0057] The siloxanyl group refers to a silicon compound group bonded via an ether bond, such as a trimethylsiloxanyl group, etc. The substituent on the silicon may be further substituted.

[0058] The boryl group is a substituted or unsubstituted boryl group. When substituted, examples of the substituent include an aryl group, a heteroaryl group, a linear alkyl group, a branched alkyl group, an aryl ether group, an alkoxy group, and a hydroxyl group, and among these, an aryl group and an aryl ether group are preferred.

[0059] The phosphine oxide group is -P(=O)R 10 R 11 R is a group represented by 10 and R 11 is a hydrogen atom or is selected from the same group as the substituents when substituted as described above.

[0060] Any two adjacent substituents may be bonded to each other to form a conjugated or non-conjugated fused ring. The fused ring may contain, in addition to carbon, an element selected from nitrogen, oxygen, sulfur, phosphorus, and silicon. The fused ring may further be fused with another ring.

[0061] The compound having the structure represented by general formula (1) exhibits a high fluorescence quantum yield and a narrow half-width of the emission spectrum at the peak emission wavelength, thereby achieving efficient color conversion and high color purity.

[0062] Furthermore, by introducing appropriate substituents into appropriate positions, various properties and physical characteristics of compounds having the structure represented by general formula (1), such as luminous efficiency, color purity, thermal stability, photostability, and dispersibility, can be adjusted. A compound having a structure represented by general formula (1) is a compound having a partial structure represented by general formula (2) or (3), and exhibits luminescence with high color purity due to the interaction between an electron-donating atom and an electron-accepting atom.

[0063] In addition, in the partial structure represented by general formula (2) or (3), the electron donor atom and the electron acceptor atom are positioned close to each other in the molecule, and the HOMO orbital and the LUMO orbital can be separated by the multiple resonance effect, and the energy levels of the singlet excited state and the triplet excited state of the compound having the structure represented by general formula (1) can be brought close to each other.

[0064] In one embodiment of the compound having the structure represented by general formula (1), the compound having the structure represented by general formula (1) is preferably a light-emitting material that emits delayed fluorescence. Light-emitting materials that emit delayed fluorescence are discussed on pages 87-103 of "State-of-the-Art Organic EL" (edited by Adachi Chinaya and Fujimoto Hiroshi, published by CMC Publishing). This document explains that by bringing the energy levels of the singlet and triplet excited states of the light-emitting material closer together, reverse energy transfer from the triplet excited state, which normally has a low transition probability, to the singlet excited state occurs with high efficiency, resulting in the manifestation of thermally activated delayed fluorescence (TADF). Furthermore, Figure 5 in this document explains the mechanism of delayed fluorescence generation. Delayed fluorescence emission can be confirmed by transient photoluminescence (PL) measurements.

[0065] In this specification, a light-emitting material that emits fluorescence by transitioning from a triplet excited state to a singlet excited state with high efficiency, including a light-emitting material that exhibits thermally activated delayed fluorescence, is referred to as a "light-emitting material that emits delayed fluorescence."

[0066] Usually, fluorescent light is emitted from a singlet excited state generated after photoexcitation of a light-emitting material, and the triplet excited state of a light-emitting material generated by intersystem crossing is thermally deactivated in a room temperature environment, and no fluorescence is emitted from the triplet excited state. On the other hand, as described above, a light-emitting material that emits delayed fluorescence emits fluorescence after a triplet excited state is generated, and therefore, the triplet excited state, which cannot contribute to light emission in ordinary fluorescent light-emitting materials, can also contribute to fluorescent light emission. Therefore, highly efficient light emission can be obtained.

[0067] Furthermore, the triplet excited state of the light-emitting material is highly reactive and has a long lifetime, so it easily reacts with surrounding molecules. For example, in the presence of oxygen, oxygen, which is highly reactive and has a large mobility, receives energy from the triplet excited state of the light-emitting material, generating singlet oxygen, which causes oxidative degradation of the light-emitting material. On the other hand, in the absence of oxygen, the molecules surrounding the light-emitting material can receive the energy. In other words, even in the absence of oxygen and no generation of singlet oxygen, if the highly reactive triplet excited state exists for a long time, reactions with surrounding molecules progress, resulting in degradation of the light-emitting material.

[0068] However, in the case of luminescent materials that emit delayed fluorescence, the triplet excited state is quickly converted to the singlet excited state, so deterioration due to reactions between this triplet excited state and surrounding molecules is unlikely to occur, and they can exhibit excellent durability. In other words, to achieve high durability, the faster the reverse intersystem crossing from the triplet excited state to the singlet excited state, the better, and the rate constant of reverse intersystem crossing is 1.0 × 10 2 s -1 The above is preferable.

[0069] Molecular design that brings the energy levels of the singlet excited state and the triplet excited state closer together is effective in linking an electron donor skeleton and an electron acceptor skeleton within the same molecule. This allows the HOMO (highest occupied molecular orbital) orbital and the LUMO (lowest unoccupied molecular orbital) orbital to be separated within the molecule. The electron donor skeleton and the electron acceptor skeleton may be bonded directly or via a linking group. In this case, the linking group is preferably a skeleton containing an aromatic hydrocarbon.

[0070] In compounds having a structure represented by general formula (1), an electron-donating nitrogen atom and an electron-accepting boron atom are located close to each other in the molecule, and the HOMO and LUMO orbitals can be separated by the multiple resonance effect.

[0071] In general formulas (2) and (3), examples of the substituted or unsubstituted aryl rings having 6 to 30 ring carbon atoms in ring Za, ring Zb, and ring Zc include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, a phenanthrene ring, a chrysene ring, an anthracene ring, and a pyrene ring, among which a benzene ring is preferred from the viewpoint of ensuring solubility.Furthermore, examples of the heteroaryl rings having 5 to 30 ring carbon atoms include aromatic heteroaryl ring structures such as a pyridine ring, a quinoline ring, and a phenanthroline ring, among which a pyridine ring is preferred from the viewpoint of ease of raw material availability and difficulty of synthesis.

[0072] In general formula (2) and general formula (3), the substituent Ra is preferably a group having 6 to 40 carbon atoms, including the substituent. The substituent Ra is preferably a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and more preferably a substituted or unsubstituted aryl group. Examples of the substituted or unsubstituted aryl group include a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted naphthyl group, and a substituted or unsubstituted phenanthrenyl group, with a substituted or unsubstituted phenyl group being more preferred.

[0073] The compound having the structure represented by general formula (1) is preferable as a light-emitting material contained in the color conversion material of the present invention because, when its π-conjugated system is expanded, reverse intersystem crossing from the triplet excited state to the singlet excited state occurs more efficiently, thereby further improving durability. 1 and Z 2 is preferably an oxygen atom or NRa, since the π-conjugated system is efficiently expanded. Similarly, in order to efficiently expand the π-conjugated system, E in general formula (2) is preferably a boron atom, and E in general formula (3) is preferably a 1 and E 2 is preferably BRa.

[0074] In addition, in the general formula (2) and the general formula (3), it is preferable that the ring Za, the ring Zb, and the ring Zc are benzene rings, since this allows the π-conjugated system to be efficiently extended.

[0075] In a compound having a structure represented by general formula (1), as described in, for example, the literature Adv. Mater., 2016, 28, 2777-2781, by optimally arranging an electron-donating amine nitrogen atom and an electron-accepting boron atom, it is possible to separate the HOMO orbital and the LUMO orbital by the multiple resonance effect. That is, in general formula (2), E is preferably a boron atom with strong electron-accepting properties, and similarly, Z 1 and Z2 is preferably NRa, which is a group with strong electron donating properties. 1 and E 2 From the viewpoint of clearly separating the HOMO orbital and the LUMO orbital and bringing the singlet excited state and the triplet excited state closer to each other, it is preferable that, in the general formula (2), E is a boron atom having a strong electron accepting property and Z 1 and Z 2 and more preferably, both are NRa, which are groups with strong electron donating properties.

[0076] Furthermore, due to the multiple resonance effect, the compound having the structure represented by general formula (1) has a sharper emission spectrum than a compound having an electron donor skeleton and an electron acceptor skeleton bonded together, and emits light with high color purity. In other words, the compound having the structure represented by general formula (1) is advantageous for improving the color gamut of the display, and is therefore preferred.

[0077] Furthermore, in compounds having a structure represented by general formula (1), rings Za, Zb, and Zc are present around the E atom in general formulas (2) and (3), where the LUMO orbital is primarily localized, and therefore the LUMO orbital can be delocalized from the E atom to each ring. Delocalizing the LUMO orbital efficiently activates the multiple resonance effect, resulting in emission of higher color purity. In particular, the partial structure represented by general formula (2) is preferred because the E atom is directly bonded to all of rings Za, Zb, and Zc, resulting in emission of higher color purity. In particular, when all n partial structures D in a compound having a structure represented by general formula (1) are represented by general formula (2), emission of higher color purity can be obtained, which is preferred.

[0078] Furthermore, a structure in which the substituent Ra in the general formula (2) and the general formula (3) is bonded to at least one of the rings Za, Zb, and Zc is more preferred. This is because the substituent Ra is bonded to at least one of the rings Za, Zb, and Zc, and thus E in the general formula (2) or E in the general formula (3) is bonded to at least one of the rings Za, Zb, and Zc. 1 and E2 This is because it is expected that the steric protection effect of the compound will be further enhanced, and the effect of suppressing a decrease in the fluorescence quantum yield will be further improved.

[0079] In general formula (1), n ​​is not particularly limited as long as it is a natural number of 2 or more, but from the viewpoint of the difficulty of synthesis, it is preferably 10 or less, more preferably 6 or less, and particularly preferably 2 or 3.

[0080] The compound having the structure represented by general formula (1) is a compound having a plurality of partial structures D. By linking the partial structures D, which are highly planar and highly aggregating when used alone, and reducing the planarity through bond angle distortion, the aggregation of the molecule as a whole can be reduced, and the deterioration of color conversion properties when dispersed at high concentrations can be suppressed.

[0081] In general formula (1), when L is a direct bond, direct bonding of partial structures D, which are relatively large polycyclic structures, occurs, resulting in large bond angle distortion, which reduces planarity and improves dispersibility, which is preferable.

[0082] In general formula (1), when L is an n-valent linking group, the overall molecular shape of the compound having the structure represented by general formula (1) becomes closer to an ellipsoid or sphere, which is preferable because it reduces aggregation. In this case, examples of the linking group include alkyl groups, cycloalkyl groups, heterocyclic groups, alkenyl groups, cycloalkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, ether bonds, thioether bonds, aryl ether groups, aryl thioether groups, carbonyl groups, carboxy groups, oxycarbonyl groups, ester groups, carbamoyl groups, amide groups, sulfonyl groups, sulfonate ester groups, sulfonamide groups, amino groups, imino groups, silyl groups, siloxanyl groups, boryl groups, and phosphine oxide groups. Among these, the linking group is preferably an aryl group or a heteroaryl group because it maintains the rigidity of the structure.

[0083] As one aspect of the light-emitting material according to the embodiment of the present invention, in the general formula (1), all of n partial structures D are represented by the general formula (2), E is a boron atom, and Z 1 and Z 2 In this case, the compound having the structure represented by general formula (1) can have high color purity, high durability, and high dispersibility.

[0084] Examples of compounds having a structure represented by general formula (1) are shown below, but the invention is not limited to these.

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] The structures exemplified above are basically unsubstituted, but examples include compounds in which some hydrogen atoms of the above compounds are substituted with a substituted or unsubstituted alkyl group, a substituted or unsubstituted diphenylamino group, a substituted or unsubstituted carbazolyl group, or a substituted or unsubstituted phenyl group. Among these, compounds in which some hydrogen atoms of these partial structures are substituted with a tert-butyl group, a diphenylamino group substituted with an alkyl group, a carbazolyl group substituted with an alkyl group, or a phenyl group substituted with an alkyl group may also be used.

[0090] The color-converting composition according to an embodiment of the present invention preferably contains a luminescent material (hereinafter referred to as "luminescent material (a)") that, when excited with light having a wavelength in the range of 400 nm to 500 nm, emits light whose peak wavelength is observed in the range of 500 nm to less than 580 nm. Hereinafter, light whose peak wavelength is observed in the range of 500 nm to less than 580 nm will be referred to as "green light emission." Generally, the greater the energy of the excitation light, the more likely it is that the material will decompose. However, excitation light having a wavelength in the range of 400 nm to 500 nm has a relatively small excitation energy, and therefore, green light with good color purity can be obtained without decomposing the luminescent material in the color-converting composition.

[0091] Furthermore, the color-converting composition according to an embodiment of the present invention preferably comprises (a) a light-emitting material that emits light having a peak wavelength of 500 nm or more and less than 580 nm when excited with excitation light having a wavelength in the range of 400 nm or more and 500 nm or less, and (b) a light-emitting material (hereinafter referred to as "light-emitting material (b)") that emits light having a peak wavelength observed in the range of 580 nm or more and 750 nm or less when excited with either or both of excitation light having a wavelength in the range of 400 nm or more and 500 nm or less and the emission from light-emitting material (a). Hereinafter, the light emission having a peak wavelength observed in the range of 580 nm or more and 750 nm or less will be referred to as "red light emission."

[0092] Because a portion of the excitation light in the wavelength range of 400 nm to 500 nm is partially transmitted through the color-converting composition or member of the present invention, when a blue LED with a sharp emission peak is used, it exhibits a sharply shaped emission spectrum in each of the blue, green, and red colors, resulting in white light with excellent color purity. As a result, a wider color gamut with more vivid colors can be efficiently produced, particularly in displays. Furthermore, in lighting applications, the emission characteristics, particularly in the green and red regions, are improved compared to white LEDs that combine a blue LED with a yellow phosphor, which is currently the mainstream, resulting in improved color rendering and making it a desirable white light source.

[0093] Examples of the light-emitting material (a) include coumarin derivatives such as coumarin 6, coumarin 7, and coumarin 153; cyanine derivatives such as indocyanine green; fluorescein derivatives such as fluorescein, fluorescein isothiocyanate, and carboxyfluorescein diacetate; phthalocyanine derivatives such as phthalocyanine green; perylene derivatives such as diisobutyl-4,10-dicyanoperylene-3,9-dicarboxylate; pyrromethene derivatives; stilbene derivatives; oxazine derivatives; naphthalimide derivatives; pyrazine derivatives; benzimidazole derivatives; benzoxazole derivatives; benzothiazole derivatives; imidazopyridine derivatives; azole derivatives; compounds having fused aryl rings such as anthracene and their derivatives; aromatic amine derivatives; and organometallic complex compounds. Compounds having a partial structure represented by the general formula (1) are also suitable because they exhibit high color purity. Two or more of these compounds may be used.

[0094] Examples of the light-emitting material (b) include cyanine derivatives such as 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran; rhodamine derivatives such as rhodamine B, rhodamine 6G, rhodamine 101, and sulforhodamine 101; pyridine derivatives such as 1-ethyl-2-(4-(p-dimethylaminophenyl)-1,3-butadienyl)-pyridinium perchlorate; perylene derivatives such as N,N'-bis(2,6-diisopropylphenyl)-1,6,7,12-tetraphenoxyperylene-3,4:9,10-bisdicarboimide; porphyrin derivatives; pyrromethene derivatives; oxazine derivatives; pyrazine derivatives; compounds having fused aryl rings such as naphthacene and dibenzodiindenoperylene; and organometallic complex compounds. Compounds having a partial structure represented by the general formula (1) are also suitable because they exhibit high color purity. Two or more of these may be contained.

[0095] In one aspect of the color-converting composition according to the present invention, the compound having the partial structure represented by general formula (1) is a light-emitting material that emits light with a peak wavelength of 500 nm or more and less than 580 nm, which is preferable because it provides green light emission with high color purity and improves color reproducibility in the green region.

[0096] In another aspect of the color-changing composition according to the present invention, the compound having the partial structure represented by general formula (1) is a light-emitting material that emits light with a peak wavelength of 580 nm or more and less than 750 nm, which is preferable because it provides red light emission with high color purity and improves color reproducibility in the red region.

[0097] As mentioned above, in order to improve color reproducibility, it is preferable that the half-width of the emission spectrum of each of blue, green, and red is small, and in particular, it is effective to have a small half-width of the emission spectrum of green light and red light. For example, the half-width of the emission spectrum of the luminescent material (a) is preferably 50 nm or less, more preferably 40 nm or less, even more preferably 35 nm or less, and particularly preferably 30 nm or less. The half-width of the emission spectrum of the luminescent material (b) is preferably 60 nm or less, more preferably 50 nm or less, even more preferably 45 nm or less, and particularly preferably 40 nm or less.

[0098] The content of the luminescent material in the color-changing composition according to the embodiment of the present invention can be selected depending on the molar absorption coefficient of the compound, the fluorescence quantum yield, the absorption intensity at the excitation wavelength, and the thickness and transmittance of the film to be produced. Here, the content of the luminescent material refers to the total content when two or more luminescent materials are contained. The content of the luminescent material is 1.0 × 10 per 100 parts by weight of the binder resin. -2 Parts by weight to 5 parts by weight are preferred.

[0099] Furthermore, when the color-changing composition contains both a luminescent material (a) that emits green light and a luminescent material (b) that emits red light, part of the green light is converted into red light, so the content w of the luminescent material (a) a and the content of the luminescent material (b) w b But, w a ≧w b The relationship between the content ratio of each material is preferably a :w b is preferably 200:1 to 3:1. a and w b is the weight percent relative to the weight of the binder resin.

[0100] The color-converting composition according to the embodiment of the present invention may contain, as the light-emitting material, other compounds as needed in addition to the compounds exemplified above. For example, an assist dopant may be contained to improve the efficiency of energy transfer from the excitation light to the light-emitting material. Furthermore, if it is desired to add a light-emitting color, the color-converting composition may further contain the above-mentioned organic light-emitting material or a known light-emitting material such as an inorganic phosphor, a fluorescent pigment, a fluorescent dye, or quantum dots.

[0101] Examples of organic light-emitting materials other than the compound represented by general formula (1) are shown below, but the present invention is not particularly limited to these.

[0102] [ka]

[0103] <Binder resin> The color-changing composition according to the embodiment of the present invention contains a binder resin in addition to at least one light-emitting material described above. Materials with excellent moldability, transparency, heat resistance, and the like are preferably used as the binder resin. Examples of binder resins include known materials such as photocurable resist materials having reactive vinyl groups, such as acrylic acid-based, methacrylic acid-based, polyvinyl cinnamate-based, and cyclic rubber-based materials, epoxy resins, silicone resins (including organopolysiloxane cured products (crosslinked products) such as silicone rubber and silicone gel), urea resins, fluororesins, polycarbonate resins, acrylic resins, urethane resins, melamine resins, polyvinyl resins, polyamide resins, phenolic resins, polyvinyl alcohol resins, cellulose resins, aliphatic ester resins, aromatic ester resins, aliphatic polyolefin resins, and aromatic polyolefin resins. Furthermore, mixtures or copolymers of these resins may also be used as the binder resin. By appropriately designing these resins, binder resins useful for the color-changing material according to the embodiment of the present invention can be obtained.

[0104] Among these resins, from the viewpoints of transparency and dispersibility of the light-emitting material, any of acrylic resins, copolymer resins containing an acrylic acid ester or methacrylic acid ester moiety, polyester resins, cycloolefin resins, epoxy resins, and silicone resins is preferable. Also, from the viewpoint of heat resistance, hydrogenated styrene-based resins, resins having a fluorene skeleton, and copolymer resins containing these resins can be suitably used.

[0105] Examples of binder resins include thermosetting resins, photocurable resins, and thermoplastic resins. Thermoplastic resins have few reactive functional groups and contain few reactive impurities such as polymerization initiators and crosslinking agents, so they are less likely to inhibit the luminescence of the luminescent material and are therefore suitable for use. From the viewpoint of heat resistance, thermosetting resins and photocurable resins are suitable for use.

[0106] When the binder resin is a thermoplastic resin, the glass transition temperature (Tg) of the resin is not particularly limited, but is preferably 30°C or higher and 180°C or lower. A Tg of 30°C or higher suppresses molecular motion of the binder resin due to heat from incident light from a light source or heat generated by the device's operation, thereby suppressing changes in the dispersion state of the luminescent material and preventing deterioration of durability. Furthermore, a Tg of 180°C or lower ensures flexibility when molded into a sheet or the like. The Tg of the binder resin is more preferably 50°C or higher and 170°C or lower, even more preferably 70°C or higher and 160°C or lower, and particularly preferably 90°C or higher and 150°C or lower. The glass transition temperature of the thermoplastic resin can be measured using a commercially available measuring instrument (e.g., a differential scanning calorimeter manufactured by Seiko Electronics Industries Co., Ltd. (trade name: DSC6220, heating rate: 0.5°C / min)).

[0107] In one aspect of the color conversion member according to the present invention, the binder resin is a polymer or hydrogenation product of at least one monomer selected from the group consisting of acrylic acid esters, methacrylic acid esters, and styrene, and preferably has a Tg of 100°C or higher. In this case, a Tg of 110°C or higher is more preferable, and a Tg of 120°C or higher is particularly preferable. These resins can be obtained by known methods, such as copolymerizing the raw material monomers in the presence of a polymerization initiator, or by polymerizing and then converting the structure through a chemical reaction such as an addition reaction, a substitution reaction, or a redox reaction. Commercially available products can also be used.

[0108] <Additives> In addition to the light-emitting material and binder resin, the color-converting composition according to the embodiment of the present invention may contain other components (additives) as necessary, such as fillers, light stabilizers, antioxidants, processing and heat stabilizers, light resistance stabilizers such as UV absorbers, dispersants and leveling agents for stabilizing the coating film, scattering agents, plasticizers, crosslinking agents such as epoxy compounds, curing agents such as amines, acid anhydrides, and imidazoles, pigments, and adhesion aids such as silane coupling agents as film surface modifiers.

[0109] Examples of fillers include fine particles of fumed silica, glass powder, quartz powder, titanium oxide, zirconia oxide, barium titanate, zinc oxide, and silicone fine particles. Two or more of these may be contained.

[0110] Examples of light stabilizers include, but are not limited to, tertiary amines, catechol derivatives, complexes containing at least one transition metal selected from the group consisting of nickel (Ni), scandium (Sc), vanadium (V), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), yttrium (Y), zirconium (Zr), molybdenum (Mo), silver (Ag), and lanthanoids, and salts with organic acids. These light stabilizers may be used alone or in combination.

[0111] Examples of the antioxidant include, but are not limited to, phenolic antioxidants such as 2,6-di-tert-butyl-p-cresol and 2,6-di-tert-butyl-4-ethylphenol. These antioxidants may be used alone or in combination.

[0112] Examples of processing and heat stabilizers include, but are not limited to, phosphorus-based stabilizers such as tributyl phosphite, tricyclohexyl phosphite, triethyl phosphine, and diphenylbutyl phosphine. These stabilizers may be used alone or in combination.

[0113] Examples of the light resistance stabilizer include, but are not limited to, benzotriazoles such as 2-(5-methyl-2-hydroxyphenyl)benzotriazole and 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole. These light resistance stabilizers may be used alone or in combination.

[0114] As the scattering particles, inorganic particles having a refractive index of 1.7 to 2.8 are preferred, and examples thereof include titania, zirconia, alumina, ceria, tin oxide, indium oxide, iron oxide, zinc oxide, aluminum nitride, aluminum, tin, titanium or zirconium sulfide, and titanium or zirconium hydroxide.

[0115] In the color-changing composition according to the embodiment of the present invention, the content of these additives can be set according to the molar absorption coefficient, fluorescence quantum yield, and absorption intensity at the excitation wavelength of the compound, as well as the size, thickness, and transmittance of the color-changing member to be produced. The content of the additives is 1.0 × 10 per 100 parts by weight of the binder resin. -3 It is preferable that the amount is 1.0×10 parts by weight or more. -2 It is more preferable that the amount is 1.0×10 parts by weight or more. -1 The content of these additives is preferably 30 parts by weight or less, more preferably 15 parts by weight or less, and even more preferably 10 parts by weight or less, relative to 100 parts by weight of the binder resin.

[0116] <Solvent> The color-changing composition according to the present invention may further contain a solvent. A solvent that can adjust the viscosity of the resin in a fluid state and that does not excessively affect the luminescence and durability of the luminescent material is preferred. Examples of solvents include water, 2-propanol, ethanol, toluene, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, hexane, cyclohexane, tetrahydrofuran, acetone, terpineol, Texanol, 1,2-dimethoxyethane, methyl cellosolve, ethyl cellosolve, butyl carbitol, butyl carbitol acetate, 1-methoxy-2-propanol, and propylene glycol monomethyl ether acetate. Two or more of these solvents can also be mixed and used. Among these solvents, toluene, methyl ethyl ketone, methyl acetate, ethyl acetate, and tetrahydrofuran are preferred because they leave little residual solvent after drying.

[0117] From the viewpoint of further improving the durability of the color conversion member, the amount of solvent remaining in the color conversion layer after drying is preferably 3.0% by mass or less, more preferably 1.0% by mass or less, and even more preferably 0.5% by mass or less. The amount of solvent remaining in the color conversion layer can be measured by gas chromatography.

[0118] <Method of manufacturing color-changing composition> An example of a method for producing a color-changing composition according to an embodiment of the present invention is described below. The luminescent material, binder resin, and, if necessary, other additives and solvents are mixed to a predetermined composition, and then the color-changing composition is obtained by homogeneously mixing or kneading the mixture using a stirrer / kneader. Examples of stirrers / kneaders include homogenizers, planetary stirrers, three-roller stirrers, ball mills, planetary ball mills, and bead mills. After mixing or dispersing, or during the mixing or dispersing process, degassing is preferably performed under vacuum or reduced pressure conditions. It is also possible to premix certain components or to perform aging or other treatments. The desired solids concentration can also be achieved by removing the solvent using an evaporator.

[0119] <Color conversion material> The color conversion member according to the embodiment of the present invention includes the color conversion composition described above or a cured product thereof. The shape of the color conversion member is not particularly limited, and examples thereof include layer, particle, and fiber shapes. One aspect of the color conversion member according to the embodiment of the present invention is a color conversion sheet including the color conversion composition or a color conversion layer formed by curing the color conversion composition.

[0120] When the color conversion member according to the embodiment of the present invention has a plurality of color conversion layers, the color conversion layers may be stacked directly or via an intermediate layer such as an adhesive layer.

[0121] The color conversion member according to the embodiment of the present invention may have a substrate or a barrier layer as needed, and may have two or more of these layers.

[0122] The substrate is not particularly limited, and known metals, films, glass, ceramics, paper, etc. can be used. Among these, glass and resin films are preferably used. As the resin film, films made of resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide, polycarbonate, polypropylene, polyimide, aramid, and silicone are preferred. To facilitate peeling of the sheet, the surface of the substrate layer may be previously subjected to a release treatment. Similarly, to improve adhesion between layers, the surface of the substrate layer may be previously subjected to an easy-adhesion treatment.

[0123] When the substrate is in the form of a film, its thickness is not particularly limited, but the lower limit is preferably 12 μm or more, more preferably 38 μm or more, and the upper limit is preferably 5000 μm or less, more preferably 3000 μm or less.

[0124] Furthermore, members such as a barrier film, a light guide plate, a diffusion plate, a diffusion film, a prism sheet, a reflective polarizing film, a wavelength-selective reflection film, a wavelength-selective transmission film, and a wavelength-selective absorption film can also be used as the substrate.

[0125] The barrier layer is preferably one that prevents oxygen, moisture, heat, etc. from penetrating into the color conversion layer, and two or more barrier layers may be provided. A barrier layer may be provided on both sides or one side of the light conversion layer.

[0126] In one aspect of the color conversion member according to the embodiment of the present invention, the color conversion member preferably has an oxygen barrier layer. This is preferable because it can prevent the oxidative degradation of the light-emitting material due to singlet oxygen generated by a dye-sensitization mechanism or the like. Furthermore, when the compound represented by general formula (1) is a light-emitting material that emits delayed fluorescence, it exhibits significantly better durability than conventional organic light-emitting materials in the absence of oxygen, so it is more preferable for the color conversion member to have an oxygen barrier layer. This is because light-emitting materials that emit delayed fluorescence have a long life and can quickly convert a triplet excited state, which is prone to react with surrounding molecules, to a singlet excited state, making them less susceptible to degradation due to reactions between this triplet excited state and surrounding molecules.

[0127] Examples of oxygen barrier layers include inorganic oxides such as silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, tin oxide, indium oxide, yttrium oxide, and magnesium oxide, inorganic nitrides such as silicon nitride, aluminum nitride, titanium nitride, and silicon carbonitride, metal oxide thin films or metal nitride thin films obtained by adding other elements to these, and films containing various resins such as polyvinylidene chloride, acrylic resins, silicone resins, melamine resins, urethane resins, fluorine resins, and polyvinyl alcohol resins such as saponified vinyl acetate. Two or more of these may be used.

[0128] As a representative structural example of a color conversion member, Figs. 1 to 6 show schematic cross-sectional views of an example of a color conversion sheet according to an embodiment of the present invention. The color conversion sheet shown in Fig. 1 has a laminated structure of a base layer 10 and a color conversion layer 11. The color conversion sheet shown in Fig. 2 has a laminated structure in which a color conversion layer 11 is sandwiched between multiple base layers 10A and 10B. The color conversion sheet shown in Fig. 3 has a laminated structure in which a color conversion layer 11 is sandwiched between multiple barrier films 12A and 12B and base layers 10A and 10B. The color conversion sheet shown in Fig. 4 has a laminated structure in which multiple color conversion layers 11A and 11B are sandwiched between multiple base layers 10A and 10B. The color conversion sheet shown in Fig. 5 has a laminated structure in which an intermediate layer 13 is included between multiple color conversion layers 11A and 11B, and is sandwiched between multiple base layers 10A and 10B. The color conversion sheet shown in Fig. 6 has a laminated structure in which an intermediate layer 13 is placed between multiple color conversion layers 11A, 11B, and is sandwiched between multiple barrier films 12A, 12B and multiple base layers 10A, 10B. However, the layers in the laminated structures shown in Figs. 1 to 6 may be in direct contact with each other or may be laminated via an adhesive layer.

[0129] Another example of a color conversion member according to an embodiment of the present invention is a color conversion substrate having a plurality of color conversion layers on a substrate. The color conversion layers on the color conversion substrate can be disposed between the partition walls (in recesses).

[0130] The color conversion member according to the embodiment of the present invention may further include an auxiliary layer having a light diffusion layer, an adhesive layer, an anti-reflection function, an anti-glare function, an anti-reflection and anti-glare function, a hard coat function (abrasion resistance function), an anti-static function, an anti-fouling function, an electromagnetic wave shielding function, an infrared blocking function, an ultraviolet blocking function, a polarizing function, or a color-tuning function, depending on the required function.

[0131] <Method of manufacturing color conversion member> The method for producing the color conversion member according to the embodiment of the present invention is not particularly limited as long as it can mold the color conversion composition according to the embodiment of the present invention into a desired shape. For example, a method can be used in which the color conversion composition is applied to a substrate and dried to form a color conversion layer. When the binder resin is a thermosetting resin, the color conversion composition can be applied to a base such as a substrate and then heat-cured to form a color conversion layer. When the binder resin is a photocurable resin, the color conversion composition can be applied to a substrate and then photocured to form a color conversion layer. Other examples include a method in which the color conversion composition is kneaded while heating and then molded using an extruder, or a method in which the color conversion composition is placed in a mold and molded by heating, cooling, drying, etc.

[0132] The application can be carried out using a reverse roll coater, blade coater, comma coater, slit die coater, direct gravure coater, offset gravure coater, kiss coater, natural roll coater, air knife coater, roll blade coater, two-stream coater, rod coater, wire bar coater, applicator, dip coater, curtain coater, spin coater, knife coater, etc., but is not limited to these.

[0133] The color conversion member can be dried using a common heating device such as a hot air dryer or an infrared dryer. In this case, the heating temperature is preferably 60 to 200°C, and the heating time is preferably 2 minutes to 4 hours. It is also possible to heat and cure the material in stages using a method such as step curing.

[0134] When the color conversion layer is formed by heat curing, a hot air oven or the like can be used as the heating device. The heating conditions can be selected depending on the binder resin. For example, the heating temperature is preferably 100°C to 300°C, and the heating time is preferably 1 minute to 2 hours.

[0135] When forming a color conversion layer by photocuring, it is preferable to irradiate with high-energy light such as ultraviolet light. The light irradiation conditions can be selected depending on the binder resin. For example, the wavelength of the irradiated light is preferably 200 nm to 500 nm, and the irradiation dose is 10 mJ / cm. 2 ~10J / cm 2 is preferred.

[0136] After the color conversion layer is produced, the substrate can be changed as needed. In this case, simple methods include a method of replacing the substrate using a hot plate, or a method using a vacuum laminator or a dry film laminator.

[0137] <Light source unit> A light source unit according to an embodiment of the present invention includes at least a light source and the color conversion composition or color conversion member described above. When the light source unit of the present invention includes a color conversion composition, the arrangement of the light source and the color conversion composition is not particularly limited. The color conversion composition may be applied directly to the light source, or the color conversion composition may be applied to a film or glass separated from the light source. When the light source unit of the present invention includes a color conversion member, the arrangement of the light source and the color conversion member is not particularly limited. The light source and the color conversion member may be closely attached to each other, or a remote phosphor type in which the light source and the color conversion member are separated from each other may be used. Furthermore, a color filter may be further included to increase color purity, and an optical member such as a prism sheet, a reflective polarizing film, or a diffusion film may be included to improve brightness and uniformity of emitted light.

[0138] One aspect of the light source unit according to the embodiment of the present invention is a configuration including a color conversion sheet having the configuration shown in Fig. 5, with a light source located below Fig. 5 and a prism sheet and a reflective polarizing film stacked above Fig. 5. A diffusion plate may be provided between the light source and Fig. 5, or a reflector may be provided below the light source.

[0139] Another aspect of the light source unit according to the embodiment of the present invention is a configuration in which a light source and a light guide plate are provided, and a color conversion layer formed by directly applying a color conversion composition is laminated on the light output side of the light guide plate. A light diffusion layer or a wavelength selective transmission layer may be further formed on the color conversion layer.

[0140] The light source unit of the present invention is useful for various light sources such as spatial lighting and backlighting, and specifically can be used for applications such as displays, lighting, interiors, signs, and billboards, but is particularly suitable for use in displays and lighting.

[0141] <Light source> Any light source can be used as long as it emits light in a wavelength range that can be absorbed by the light-emitting material used in the present invention. For example, any light source can in principle be used, such as a hot cathode tube, a cold cathode tube, a fluorescent light source such as an inorganic EL, an organic electroluminescence element light source, an LED light source, an incandescent light source, or sunlight. Among these, an LED or an organic electroluminescence element is preferred in terms of color purity, and an LED is more preferred.

[0142] For display and lighting applications, a light source having a maximum emission wavelength in the range of 400 to 500 nm is preferred because it can enhance the color purity of blue light. Furthermore, a blue LED having a maximum emission wavelength in the range of 430 to 480 nm is more preferred, and a blue LED having a maximum emission wavelength in the range of 445 to 470 nm is even more preferred.

[0143] The light source may have one emission peak or two or more emission peaks, but in order to improve color purity, it is preferable to use a light source having one emission peak. It is also possible to use a combination of multiple light sources with different emission peaks. <Displays, lighting equipment> A display according to an embodiment of the present invention includes at least a light source unit including a light source and a color conversion material composition or a color conversion member as described above. For example, in a display such as a liquid crystal display, the above-described light source unit is used as a backlight unit.

[0144] Furthermore, an illumination device according to an embodiment of the present invention includes at least a light source unit including a light source and a color conversion material composition or a color conversion member as described above. For example, this illumination device is configured to emit white light by combining a blue LED light source as the light source unit with a color conversion material composition or a color conversion member that converts blue light from the blue LED light source to light with a longer wavelength. [Example]

[0145] The present invention will be described below with reference to examples, but the present invention is not limited to these examples. First, the evaluation methods used in the examples will be described.

[0146] <Evaluation of color conversion characteristics> A current of 30 mA was passed through a light-emitting device equipped with the color conversion member prepared in each example and comparative example and a blue LED (manufactured by USHIO EPITEX; model number SMBB450H-1100, emission peak wavelength: 450 nm) to light up the blue LED, and the peak intensity of the color-converted light was measured using a spectroradiometer (CS-1000, manufactured by Konica Minolta).

[0147] <Light-emitting materials> In the following examples and comparative examples, compounds D-1 and D-2 are the compounds shown below.

[0148] [ka]

[0149] Example 1 PMMA resin BR-85 (manufactured by Mitsubishi Chemical Corporation) was used as the binder resin. 100 parts by weight of the binder resin were mixed with 0.2 parts by weight of compound D-1 as the luminescent material, 3 parts by weight of titanium dioxide particles JR-301 (manufactured by Teika Corporation) as the scattering material, and 400 parts by weight of toluene as the solvent. The mixture was then stirred and degassed at 1000 rpm for 20 minutes using a planetary stirring and degassing device "Mazerustar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.) to obtain a resin composition for producing a color conversion layer.

[0150] Next, the resin liquid for preparing the color conversion layer was applied to a polyethylene terephthalate film "Lumirror" (registered trademark) U34 (manufactured by Toray Industries, Inc., thickness 75 μm) using a film applicator, and heated and dried at 120°C for 20 minutes to form a color conversion layer with an average thickness of 8 μm, thereby producing a sheet-like color conversion member.

[0151] When blue LED light was color-converted using this sheet-like color-converting material, high-color-purity blue-green light was obtained, with a peak wavelength of 490 nm and a half-width of the emission spectrum at the peak wavelength of 25 nm. The peak intensity of the color-converted light in Example 1 was set to 100, and the results are compared with those in Example 2, Comparative Example 1, and Comparative Example 2 (described later) in Table 1.

[0152] Example 2 A sheet-like color conversion member was produced in the same manner as in Example 1, except that the amount of the luminescent material mixed was changed to 0.1 parts by weight per 100 parts by weight of the binder resin and the thickness of the color conversion layer was changed to 16 μm. The results are shown in Table 1.

[0153] Comparative Example 1 A sheet-like color converting member was produced in the same manner as in Example 1, except that the luminescent material was changed to D-2 and the amount of the luminescent material mixed was adjusted to be the same as that of D-1 in Example 1. The results are shown in Table 1.

[0154] Comparative Example 2 A sheet-like color converting member was produced in the same manner as in Example 2, except that the luminescent material was changed to D-2 and the amount of the luminescent material mixed was adjusted to be the same as that of D-1 in Example 2. The results are shown in Table 1.

[0155] [Table 1]

[0156] In Comparative Examples 1 and 2, a significant decrease in the emission peak intensity was observed as the amount of the luminescent material mixed increased. On the other hand, in Examples 1 and 2, the decrease in the emission peak intensity as the amount of the luminescent material mixed increased was small. In other words, by using the color-converting composition of the present invention, it is possible to suppress the decrease in luminescent efficiency when forming a thin film without changing the number of moles of organic luminescent material per unit volume, and it is possible to achieve both high color purity and high efficiency luminescence. [Explanation of symbols]

[0157] 1 Color conversion sheet 10, 10A, 10B base material layer 11, 11A, 11B color conversion layer 12, 12A, 12B Barrier Film 13 Middle class

Claims

1. A color-changing composition comprising at least one organic light-emitting material and a binder resin, wherein the at least one organic light-emitting material contains a compound having a structure represented by general formula (1): 【Chemical 1】 n is a natural number of 2 or more. L represents a direct bond or an n-valent linking group. D is a partial structure represented by general formula (2) or (3), and the n Ds may be the same or different. 【Chemistry 2】 (In general formula (2) and general formula (3), ring Za, ring Zb, and ring Zc are each independently a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl ring having 4 to 30 ring carbon atoms. In general formula (2), Z 1 and Z 2 are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom. 1 When R is NRa, the substituent R may be bonded to the ring Za or the ring Zb to form a ring. 2 When R is NRa, the substituent R may be bonded to the ring Z or the ring Zc to form a ring. In the general formula (2), E is a boron atom, a phosphorus atom, SiR (a silicon atom having a substituent R) or P=O. In the general formula (3), E 1 and E 2 each independently represents BRa (a boron atom having a substituent Ra), PRa (a phosphorus atom having a substituent Ra), SiRa 2 (a silicon atom having two substituents Ra), P(=O)Ra 2 (phosphine oxide having two substituents Ra) or P(=S)Ra 2 (phosphine sulfide having two substituents Ra), C═O (carbonyl group), S(═O) or S(═O) 2 It is. 1 is BRa, PRa, SiRa 2 , P(=O)Ra 2 or P(=S)Ra 2 In the case where R a is a substituted or unsubstituted aryl, R a may be bonded to R a or R b to form a ring. 2 is BRa, PRa, SiRa 2 , P(=O)Ra 2 or P(=S)Ra 2 In this case, the substituent Ra may be bonded to the ring Za or the ring Zc to form a ring. Each of the substituents Ra is independently selected from a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, a halogen atom, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, an ester group, a carbamoyl group, an amide group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, an amino group, an imino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, a phosphine oxide group, and a fused ring or an aliphatic ring formed between adjacent substituents. The substituent Ra may be further substituted with a selected substituent, and these substituents may be further substituted with a selected substituent. However, in the general formula (2) or (3), the ring Za, ring Zb, ring Zc, and Z 1 , Z 2 , E 1 , E 2 and a substituent Ra substituted thereon, forms a bond with L on at least one element forming any one of them. In addition, when at least one of the n partial structures D in the general formula (1) is represented by the general formula (2), at least one of the partial structures D represented by the general formula (2) has Z 1 and Z 2 At least one of these is NRa.

2. E in the general formula (2) is a boron atom, and E in the general formula (3) is 1 and E 2 The color converting composition of claim 1 wherein is BRa.

3. Z in the general formula (2) 1 and Z 2 The color converting composition of claim 1 wherein is NRa.

4. 2. The color-changing composition according to claim 1, wherein all n D's are represented by general formula (2).

5. The color converting composition of claim 1 wherein L represents a direct bond.

6. 2. The color-changing composition according to claim 1, wherein L is an n-valent linking group that includes an aryl ring having 3 to 30 ring members or a heteroaryl ring having 3 to 30 ring members.

7. 2. The color converting composition of claim 1, wherein n is 2 or 3.

8. A cured product of the color-changing composition according to any one of claims 1 to 7.

9. A color-changing member comprising the color-changing composition according to any one of claims 1 to 7 or a cured product thereof.

10. The color conversion member according to claim 9 , which has an oxygen barrier layer.

11. A light source unit comprising a light source and the color conversion member according to claim 9.

12. A display comprising the light source unit according to claim 11.

13. A lighting device comprising the light source unit according to claim 11.

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