Pyrromethene boron complex, color conversion composition, color conversion member, light source unit, display, and illumination device

Abstract

The present invention achieves both durability and improvement in color reproducibility in a color conversion member for use in a light source unit, a display, and an illumination device. The purpose of the present invention is to provide: a color conversion composition from which it is possible to provide a color conversion member achieving, in particular, both durability and emission of light having a high color purity; and a pyrromethene boron complex contained in said color conversion composition. The present invention pertains to a pyrromethene boron complex represented by specific formula (1).

Description

Pyrromethene boron complex, color-converting composition, color-converting member, light source unit, display, and lighting device

[0001] The present invention relates to a pyrromethene boron complex, a color-changing composition, a color-changing member, a light source unit, a display, and a lighting device.

[0002] There has been 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 a light emitter into light with a longer wavelength, such as converting blue light into green or red light.

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

[0004] Issues facing displays that utilize a color conversion system 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, color conversion materials containing organic fluorescent materials have been proposed (see, for example, Patent Documents 1 and 2). Furthermore, techniques for improving durability have been proposed, such as adding a light stabilizer (see, for example, Patent Document 3) and using an oxygen barrier (see, for example, Patent Document 4).

[0005] JP 2010-61824 A JP 2014-136771 A JP 2019-50381 A WO 2017 / 057287

[0006] Color-converting compositions having excellent color reproducibility and relatively excellent durability can be obtained by the techniques described in Patent Documents 1 to 4. However, in recent years, with the trend toward higher definition such as 4K and 8K, high dynamic range (HDR), and higher contrast due to local dimming, the illuminance required for light source units of displays has increased, and higher durability has also been required for color-converting members.

[0007] The problem to be solved by the present invention is to achieve both improved color reproducibility and durability in color conversion members used in light source units, displays, and lighting devices. In particular, the present invention aims to provide a color conversion composition that enables the provision of a color conversion member that achieves both high color purity light emission and durability, and a pyrromethene boron complex contained therein.

[0008] In order to solve the above-mentioned problems and achieve the object, the present invention has any one of the following configurations: [1] A pyrromethene boron complex represented by the following general formula (1):

[0009]

[0010] (In general formula (1), R １ ~R ６ may be the same or different and are selected from a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, a halogen atom, a cyano group, an aldehyde group, a carboxyl group, an ester group, an amide group, an acyl group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, a nitro group, a silyl group, a siloxanyl group, a boryl group, and a phosphine oxide group. １ and R ２ , R ２ and R ３ One of the two pairs is a ring structure of the following general formula (2): ７ is a group represented by the following general formula (3): ８ and R ９may be the same or different and are selected from an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, a halogen atom, or a cyano group.

[0011]

[0012] (In general formula (2), R １０１ and R １０２ represents R in the general formula (1). １ ~R ６ Ar is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocycle. １０１ and R １０２ may form a ring. * indicates the linkage with the pyrromethene skeleton.

[0013]

[0014] (In general formula (3), L １ and L ２ is a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. x and y are integers of 1 to 5. ２０１ is an electron-withdrawing group.) [2] R in the general formula (3) ２０１ [3] The pyrromethene boron complex according to [1], wherein R in the general formula (1) is a fluorine atom, a fluorine-containing aryl group, a fluorine-containing heteroaryl group, a fluorine-containing alkyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted ester group, a substituted or unsubstituted amide group, a substituted or unsubstituted sulfonyl group, or a cyano group. ４ and R ６ at least one of R in the general formula (3) is a fluorine atom, a fluorine-containing aryl group, a fluorine-containing heteroaryl group, or a fluorine-containing alkyl group; ２０１ [4] The pyrromethene boron complex according to [1] or [2], wherein L in the general formula (3) is an ester group or an acyl group. １[5] The pyrromethene boron complex according to any one of [1] to [3], wherein L in the general formula (3) is a substituted or unsubstituted arylene group. １ and L ２ The pyrromethene boron complex according to [4], characterized in that R in the general formula (1) is a substituted or unsubstituted arylene group. [6] The pyrromethene boron complex according to [5], characterized in that x and y in the general formula (3) are integers of 1 to 3. [7] The pyrromethene boron complex according to any one of [1] to [6], characterized in that Ar in the general formula (2) is a substituted or unsubstituted benzene ring. [8] The pyrromethene boron complex according to any one of [1] to [6], characterized in that R in the general formula (1) is a substituted or unsubstituted benzene ring. ４ ~R ６ [9] The pyrromethene boron complex according to any one of [1] to [7], wherein R in the general formula (1) is a group that does not form a ring structure with an adjacent group. ８ and R ９

[10] The pyrromethene boron complex according to any one of [1] to [8], wherein any one of R in the general formula (1) is a fluorine atom. ８ and R ９

[11] The pyrromethene boron complex according to any one of [1] to [8], wherein any one of the groups is a cyano group.

[11] The pyrromethene boron complex according to any one of [1] to

[10] , wherein, when excited with light, it emits light having a peak wavelength observed in the region of 580 nm or more and less than 750 nm.

[12] A color conversion composition that converts incident light into light with a wavelength longer than that of the incident light, the color conversion composition comprising the pyrromethene boron complex according to any one of [1] to

[11] and a binder resin.

[13] A color conversion member comprising a color conversion layer made of the color conversion composition according to

[12] or a cured product thereof.

[14] A light source unit comprising a light source and the color conversion member according to

[13] .

[15] A display comprising the light source unit according to

[14] .

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

[14] .

[0015] The pyrromethene boron complex of the present invention, the color-converting composition using the same, and the color-converting member using the same achieve both high color purity and durability, and therefore it is possible to achieve both color reproducibility and durability.

[0016] Schematic cross-sectional view showing an example of a color conversion member of the present invention. Schematic cross-sectional view showing an example of a color conversion member of the present invention. Schematic cross-sectional view showing an example of a color conversion member of the present invention. Schematic cross-sectional view showing an example of a color conversion member of the present invention. Schematic cross-sectional view showing an example of a color conversion member of the present invention. Schematic cross-sectional view showing an example of a color conversion member of the present invention.

[0017] Hereinafter, embodiments of the present invention will be specifically described, but the present invention is not limited to the following embodiments and can be practiced with various modifications depending on the purpose and application. Furthermore, matters cited as preferred examples in specific embodiments and embodiments can also be applied to other embodiments and embodiments. (Compound) A compound according to an embodiment of the present invention is a pyrromethene boron complex represented by general formula (1).

[0018]

[0019] (In general formula (1), R １ ~R ６ may be the same or different and are selected from a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, a halogen atom, a cyano group, an aldehyde group, a carboxyl group, an ester group, an amide group, an acyl group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, a nitro group, a silyl group, a siloxanyl group, a boryl group, and a phosphine oxide group. １ and R ２ , R ２ and R ３ One of the two pairs is a ring structure of the following general formula (2): ７ is a group represented by the following general formula (3): ８ and R ９may be the same or different and are selected from an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, a halogen atom, or a cyano group.

[0020]

[0021] (In general formula (2), R １０１ and R １０２ represents R in the general formula (1). １ ~R ６ Ar is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocycle. １０１ and R １０２ may form a ring. * indicates the linkage with the pyrromethene skeleton.

[0022]

[0023] (In general formula (3), L １ and L ２ is a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. x and y are integers of 1 to 5. ２０１ is an electron-withdrawing group.) In all of the above groups, hydrogen may be replaced with deuterium. The same applies to the compounds or partial structures thereof described below.

[0024] In the following description, for example, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms means 6 to 40 carbon atoms including the number of carbon atoms contained in substituents substituted on the aryl group, and the same applies to other substituents specifying the number of carbon atoms.

[0025] 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.

[0026] In all of the above groups, the substituent when substituted is 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.

[0027] 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 the alkyl group is substituted, the additional substituent is not particularly limited, and examples thereof include an alkyl group, a halogen atom, an aryl group, and a heteroaryl group, and this point is also applicable 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, from the viewpoints of availability and cost.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The aryl ether group is 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.

[0036] 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.

[0037] 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 6 to 40, more preferably 6 to 30.

[0038] 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.

[0039] 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.

[0040] 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. " 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. However, a 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.

[0041] 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.

[0042] 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.

[0043] Halogen refers to an atom selected from fluorine, chlorine, bromine and iodine.

[0044] 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. The sulfonyl group, sulfonate ester group, and sulfonamide group are each -S(=O) ２ R １０ , -S(=O) ２ OR １０ , -S(=O) ２ NR 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.

[0045] 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. As the aryl group and the heteroaryl group, a phenyl group, a naphthyl group, a pyridyl group, and a quinolinyl group are preferred. 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.

[0046] 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 silicon 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.

[0047] 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.

[0048] 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.

[0049] The phosphine oxide group is —P(═O)R １０ R １１ R is a group represented by the formula: １０ and R １１ is a hydrogen atom or is selected from the same group as the substituents when substituted as described above.

[0050] 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.

[0051] The compound having the structure represented by general formula (1) has a pyrromethene metal complex skeleton, which is strong and highly planar, and therefore 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.

[0052] Generally, when a pyrromethene boron complex is used to emit light in the wavelength region longer than green, the pyrromethene boron complex has a double-bonded group directly bonded to the complex skeleton, thereby extending the conjugation and lengthening the emission wavelength. However, if the double-bonded group is simply bonded to the complex skeleton, the pyrromethene boron complex will change to multiple stable structures in its excited state (this phenomenon is hereinafter referred to as "structural relaxation"), resulting in deactivation accompanied by emission from various energy states. In this case, the emission spectrum will be broadened, the half-width will be large, and the color purity will be reduced. In other words, in order to lengthen the emission wavelength using a pyrromethene boron complex, ingenuity in molecular design is required.

[0053] The pyrromethene boron complex of the present invention is a compound represented by general formula (1), which has a ring structure represented by the above general formula (2) in the pyrromethene boron complex skeleton. Each ring structure of general formula (2) has a double bond, and the double bond is always chemically bonded to the pyrromethene boron complex skeleton via a carbon atom. This makes it possible to suppress excessive structural relaxation in the excited state, thereby sharpening the emission spectrum of the compound represented by general formula (1). When this compound is used as a light-emitting material, it is possible to obtain light emission with good color purity. In other words, when the compound represented by general formula (1) is used in a color-converting composition, it becomes possible to efficiently create a wider color gamut, improving color reproducibility.

[0054] In the pyrromethene boron complex of the present invention, R ７ has a group represented by the above general formula (3). The group structure of general formula (3) is an electron-withdrawing group R ２０１ The color-changing composition of this embodiment converts light color by exciting the contained pyrromethene boron complex with excitation light and emitting light of a wavelength different from that of the excitation light. By introducing an electron-withdrawing group into the pyrromethene boron complex skeleton, the electron density of the pyrromethene boron complex skeleton can be reduced. This improves the stability of the compound represented by general formula (1) against oxygen, thereby improving durability.

[0055] In the compound represented by general formula (1), R １ and R ２ and R ２ and R ３ One of the two pairs of R ７ is the group structure represented by general formula (3), the pyrromethene boron complex has high color reproducibility and high durability.

[0056] From the viewpoint of thermal stability and light stability, the ring structure represented by general formula (2) is preferably R １ and R ２ In the case of a pair with ３ But, R ２ and R ３ In the case of a pair with １ is preferably a substituted or unsubstituted alkyl group or aryl group.

[0057] The group structure of general formula (3) is L １ and L ２ is a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. x and y are integers of 1 to 5.

[0058] L in general formula (3) １ is preferably a substituted or unsubstituted arylene group, because it can impart bulkiness to the compound represented by general formula (1) and improve the luminous efficiency. ７ By having a certain degree of bulkiness, the compounds in the composition aggregate with each other over time, which results in preventing a decrease in luminescence intensity due to concentration quenching, and further improving luminescence efficiency and durability. In addition, structural changes in the excited state can be suppressed, further improving durability.

[0059] From this viewpoint, L in general formula (3) １ and L ２ is preferably a substituted or unsubstituted arylene group. １ and L ２is preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, or a substituted or unsubstituted naphthyl group, more preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, or a substituted or unsubstituted terphenyl group, and particularly preferably a substituted or unsubstituted phenyl group.

[0060] Furthermore, x and y in the general formula (3) are preferably integers of 1 to 3. In this case, R ７ Durability can be further improved by appropriately suppressing the twist of the carbon-carbon bond in the pyrromethene skeleton. If the twist is too large, the reactivity to excitation light increases, and photostability decreases.

[0061] The electron-withdrawing group is also called an electron-accepting group, and in organic electronics theory, is an atomic group that attracts electrons from the substituted atomic group due to the inductive effect or resonance effect. Examples of electron-withdrawing groups include those whose Hammett's rule substituent constant (σp(para)) takes a positive value. The Hammett's rule substituent constant (σp(para)) can be cited from the Revised 5th Edition of the Basic Chemistry Handbook (page II-380).

[0062] Examples of the electron-withdrawing group include -F (σp: +0.06), -Cl (σp: +0.23), -Br (σp: +0.23), -I (σp: +0.18), and -CO ２ R １２ (σp:R １２ is an ethyl group, +0.45), -CONH ２ (σp: +0.38), -COR １２ (σp:R １２ is a methyl group, +0.49), -CF ３ (σp: +0.50), -SO ２ R １２ (σp:R １２ is a methyl group, +0.69), -NO ２ (σp: +0.81) and the like. １２each independently represents a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 1 to 30 carbon atoms. Specific examples of each of these groups include the same examples as above.

[0063] R in general formula (3) ２０１ is preferably a fluorine atom, a fluorine-containing aryl group, a fluorine-containing heteroaryl group, a fluorine-containing alkyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted ester group, a substituted or unsubstituted amide group, a substituted or unsubstituted sulfonyl group, or a cyano group.

[0064] In addition, from the viewpoint of controlling the fluorescence wavelength and absorption wavelength and increasing the compatibility with the solvent, R ２０１ is more preferably a substituted or unsubstituted ester group or a halogen.

[0065] In the general formula (2), Ar is preferably a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted phenanthrene ring, a substituted or unsubstituted pyridine ring, a substituted or unsubstituted pyrimidine ring, or a substituted or unsubstituted pyrazine ring. Furthermore, if Ar is a substituted or unsubstituted benzene ring, the thermal and electrical stability is improved, so it is particularly preferred. That is, in the general formula (2), Ar is preferably a substituted or unsubstituted benzene ring.

[0066] R in general formula (1) ４ ~R ６ is preferably a group that does not form a ring structure with an adjacent group. ４ ~R ６When a ring structure is formed between adjacent groups, the Stokes shift becomes excessively small, resulting in a decrease in luminous efficiency. The Stokes shift is the difference between the maximum absorption wavelength and the maximum fluorescence wavelength. In a color conversion sheet that converts wavelengths by absorbing light in a specific wavelength band (e.g., excitation light) and emitting light in a target wavelength band, if there is a large overlap between the absorption spectrum in the specific wavelength band and the emission spectrum in the target wavelength band, re-absorption occurs, in which the emitted light is absorbed again. This reduces the luminous efficiency of the color conversion sheet. Therefore, from the perspective of luminous efficiency, it is preferable that the Stokes shift is large and the overlap between the absorption spectrum and the emission spectrum is small.

[0067] From the viewpoint of thermal stability and light stability, R ４ and R ６ is more preferably an aryl group or a heteroaryl group. From the viewpoint of improving durability by reducing the electron density of the pyrromethene skeleton, R ４ and R ６ An aryl group having an electron-withdrawing group is particularly preferred. The electron-withdrawing group is preferably a substituent containing fluorine. Furthermore, from the viewpoint of suppressing free rotation and improving luminous efficiency, an aryl group having a substituent at the ortho position is preferred.

[0068] As mentioned above, from the viewpoint of photostability, R is closer to the pyrromethene skeleton. ４ and R ６ Since it is preferable to lower the electron density of R ４ and R ６ In view of compatibility with the solvent, it is preferable that at least one of R ２０１ From the viewpoint of compatibility with resins, R in general formula (3) is preferably an ester group or an acyl group. ２０１ is particularly preferably an ester group. The ester group and the acyl group are each represented by —C(═O)OR １０ , -C(=O)R １０ is a group represented by R １０is selected from the same group as the substituents when hydrogen or the above-mentioned substituents are substituted. １０ is preferably an aryl group or a heteroaryl group. From the viewpoint that durability is improved by reducing the electron density of the pyrromethene skeleton, R １０ is particularly preferably an aryl group having an electron-withdrawing group.

[0069] In general formula (1), R ８ and R ９ Preferably, any one of R in the general formula (1) is a fluorine atom or a cyano group. ８ and R ９ It is preferable that any one of R in the general formula (1) is a fluorine atom. ８ and R ９ Preferably, any one of the groups is a cyano group, which can reduce the electron density of the pyrromethene boron complex skeleton.

[0070] Furthermore, in the general formula (1), R ８ and R ９ At least one of R is preferably a cyano group. ８ and R ９ are more preferably cyano groups. In this case, by introducing two cyano groups onto the boron atom of the pyrromethene skeleton, the electron density of the pyrromethene skeleton can be further reduced. This further improves the stability of the compound represented by general formula (1) against oxygen, and as a result, the durability of the compound can be significantly improved.

[0071] As described above, the compound represented by general formula (1) can achieve both high color purity and high durability by having the above general formulas (2) and (3) in the pyrromethene boron complex skeleton. Furthermore, the compound represented by general formula (1) exhibits a high luminescence quantum yield and a narrow half-width peak of the emission spectrum, thereby achieving efficient color conversion and high color purity.

[0072] Furthermore, by introducing appropriate substituents into appropriate positions of the compound having the structure represented by general formula (1), various characteristics and physical properties such as luminous efficiency, color purity, thermal stability, photostability, and dispersibility can be adjusted.

[0073] Examples of the structure represented by general formula (1) are shown below, but the invention is not limited to these.

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] Examples of the compound include compounds in which some of the hydrogen atoms in these structures 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 of the hydrogen atoms in these 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 be used.

[0080] The pyrromethene boron complex of the present invention can be synthesized by referring to the methods described in J. Org. Chem., Vol. 64, No. 21, pp. 7813-7819 (1999), Angew. Chem., Int. Ed. Engl., Vol. 36, pp. 1333-1335 (1997), etc., to synthesize the compound represented by general formula (1). For example, a method can be used in which a compound represented by the following general formula (4) and a compound represented by the following general formula (5) are heated in 1,2-dichloroethane in the presence of phosphorus oxychloride, and then a compound represented by the following general formula (6) is reacted in 1,2-dichloroethane in the presence of triethylamine to obtain the compound represented by general formula (1). However, the pyrromethene boron complex of the present invention is not limited to this method. Here, R １ ~R９ is the same as described above. J represents a halogen.

[0081]

[0082] Furthermore, when introducing an aryl group or a heteroaryl group, a method of forming a carbon-carbon bond using a coupling reaction between a halogenated derivative and a boronic acid or a boronate ester derivative can be used, but the pyrromethene boron complex of the present invention is not limited to this. Similarly, when introducing an amino group or a carbazolyl group, a method of forming a carbon-nitrogen bond using a coupling reaction between a halogenated derivative and an amine or a carbazole derivative in the presence of a metal catalyst such as palladium can be used, but the pyrromethene boron complex of the present invention is not limited to this.

[0083] The pyrromethene boron complex of the present invention preferably exhibits emission observed with peak wavelengths in the range of 580 nm to 750 nm when excited with excitation light. Hereinafter, emission observed with peak wavelengths in the range of 580 nm to 750 nm may be referred to as "red emission." Generally, the higher the energy of excitation light, the more likely it is to cause decomposition of the luminescent material. However, excitation light in the wavelength range of 430 nm to 500 nm has relatively low excitation energy. Therefore, red emission with good color purity can be obtained without causing decomposition of the luminescent material. Examples of methods for measuring the fluorescence spectrum include dissolving the compound in an organic solvent such as toluene and exciting the compound with excitation light in the wavelength range of 430 nm to 500 nm, and measuring the fluorescence spectrum.

[0084] A color-converting composition according to an embodiment of the present invention converts incident light into light with a wavelength longer than that of the incident light, and includes the pyrromethene boron complex of the present invention and a binder resin. The color-converting composition of the present invention preferably includes (a) a light-emitting material (hereinafter referred to as "light-emitting material (a)") that emits light with a peak wavelength of 500 nm or more and less than 580 nm when using excitation light with a wavelength range of 400 nm or more and 500 nm or less, or a light-emitting material (hereinafter referred to as "light-emitting material (b)") that emits light with a peak wavelength observed in the range of 580 nm or more and less than 750 nm when using excitation light with a wavelength range of 400 nm or more and 500 nm or less. Hereinafter, light emission with a peak wavelength observed in the range of 580 nm or more and less than 750 nm is referred to as "red light emission." Generally, the higher the energy of excitation light, the more likely it is that material decomposition will occur. However, excitation light with a wavelength range of 400 nm or more and 500 nm or less has a relatively low excitation energy, and therefore green light with good color purity can be obtained without decomposing the light-emitting material in the color-converting composition.

[0085] Furthermore, the color-converting composition according to an embodiment of the present invention preferably comprises (a) a light-emitting material that, when excited by excitation light having a wavelength in the range of 400 nm to 500 nm, emits light having a peak wavelength of 500 nm to less than 580 nm, and (b) a light-emitting material that, when excited by either or both of excitation light having a wavelength in the range of 400 nm to 500 nm or the emission from light-emitting material (a), emits light having a peak wavelength observed in the range of 580 nm to 750 nm. Hereinafter, the light emission having a peak wavelength observed in the range of 500 nm to 580 nm will be referred to as "green light emission."

[0086] Because a portion of excitation light in the wavelength range of 400 nm to 500 nm is partially transmitted through the color conversion composition or color conversion member of the present invention, when a blue LED with a sharp emission peak is used, a sharply shaped emission spectrum is exhibited 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 and a yellow phosphor, which are currently mainstream, resulting in improved color rendering and making this a desirable white light source.

[0087] 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 derivatives thereof; aromatic amine derivatives; and organometallic complex compounds. Among these compounds, pyrromethene derivatives are particularly preferred because they provide a high fluorescence quantum yield and exhibit emission with high color purity. Two or more of these compounds may be contained.

[0088] Examples of the light-emitting material (b) include cyanine derivatives such as 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostillyl)-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 a fused aryl ring such as naphthacene and dibenzodiindenoperylene; and organic metal complex compounds. Compounds having a structure represented by the above general formula (1) are also suitable because they exhibit high color purity. Among these compounds, pyrromethene derivatives are particularly preferred because they provide high fluorescence quantum yields and exhibit luminescence with high color purity, and among these, compounds having a structure represented by the above-mentioned general formula (1) are preferred because they dramatically improve durability. Two or more of these may be contained.

[0089] In one aspect of the color-converting composition according to the present invention, the compound having the structure represented by general formula (1) is a light-emitting material that emits light having a peak wavelength of 500 nm or more and less than 580 nm. In this case, green light emission with high color purity is obtained, and color reproducibility in the green region is improved, which is preferable.

[0090] In another aspect of the color-converting composition according to the present invention, the compound having the structure represented by general formula (1) is a light-emitting material that emits light having 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.

[0091] As described 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 improve color reproducibility if the half width of the emission spectrum of green light and red light is small. 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. The half width of the emission spectrum of the luminescent material (b) is more preferably 35 nm or less.

[0092] 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, fluorescence quantum yield, and absorption intensity at the excitation wavelength of the compound, as well as 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.

[0093] 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, a part of the green light is converted into red light, so the content w of the luminescent material (a) ａ and the content w of the luminescent material (b). ｂ But, lol 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.

[0094] The color-converting composition according to the embodiment of the present invention may contain other compounds as needed in addition to the compound represented by general formula (1). 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 different color to the emitted light, the color-converting composition may further contain the aforementioned organic light-emitting material or a known light-emitting material such as an inorganic phosphor, a fluorescent pigment, a fluorescent dye, or quantum dots.

[0095] 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.

[0096]

[0097] <Binder Resin> The color-changing composition according to the embodiment of the present invention contains a binder resin in addition to the compound represented by the general formula (1) 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.

[0098] 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.

[0099] Among these, from the viewpoint of achieving both dispersibility and heat resistance of the light-emitting material, a polymer or hydrogenated product of at least one monomer selected from the group consisting of acrylic acid esters, methacrylic acid esters, and styrene is preferred. However, in the present invention, "hydrogenated product" refers to a compound having a structure obtained by a hydrogenation reaction, i.e., a reaction in which hydrogen atoms are added to multiple bond sites using hydrogen gas or the like as a reducing agent. For example, a hydrogenated product of an acrylic-styrene copolymer resin refers to a resin having a structure in which some or all of the benzene rings derived from the styrene in the acrylic-styrene copolymer resin are replaced with cyclohexane rings. The hydrogenation rate is not particularly limited. These resins can be obtained, for example, by copolymerizing the respective raw material monomers in the presence of a polymerization initiator. Commercially available products can also be used.

[0100] 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.

[0101] 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. When the Tg is 30°C or higher, molecular motion of the binder resin due to heat from incident light from a light source or heat from operating the device is suppressed, and changes in the dispersion state of the luminescent material are suppressed, thereby preventing deterioration of durability. Furthermore, when the Tg is 180°C or lower, flexibility can be ensured 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. Here, the glass transition temperature of the thermoplastic resin can be measured using a commercially available measuring instrument (for example, a differential scanning calorimeter (trade name DSC6220, heating rate 0.5°C / min) manufactured by Seiko Electronics Co., Ltd.).

[0102] The binder resin is preferably a polymer or hydrogenated product of at least one monomer selected from the group consisting of acrylic acid esters, methacrylic acid esters, and styrene, and has a Tg of 100°C or higher. In this case, the Tg is more preferably 110°C or higher, and particularly preferably 120°C or higher. These resins can be obtained, for example, by copolymerizing the raw material monomers in the presence of a polymerization initiator. Commercially available products can also be used. Examples of commercially available resins include the DIANAL (trademark) series (e.g., BR-80, BR-83, BR-85, BR-88) manufactured by Mitsubishi Chemical Corporation, the Optimas (trademark) series (e.g., Optimas 6500, Optimas 7500) manufactured by Mitsubishi Gas Chemical Co., Ltd., the Estyrene (registered trademark) MS series (e.g., MS-200) manufactured by Nippon Steel Chemical & Material Co., Ltd., the Cevian MAS series (e.g., MAS30F) manufactured by Daicel Miraize Co., Ltd., and the Denka TX Polymer series (e.g., TX-100S) manufactured by Denka Co., Ltd., but are not limited thereto.

[0103] <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 needed, such as fillers, light stabilizers, antioxidants, processing and heat stabilizers, light resistance stabilizers such as ultraviolet absorbers, dispersants and leveling agents for stabilizing the coated 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] <Solvent> The color-changing composition according to the embodiment of 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.

[0112] 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.

[0113] <Method for Producing Color-Converting Composition> An example of a method for producing a color-converting composition according to an embodiment of the present invention is described below. The above-described luminescent material, binder resin, and, if necessary, other additives and solvents are mixed to a predetermined composition, and then the color-converting 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 treatments such as aging. It is also possible to remove the solvent using an evaporator to achieve a desired solids concentration.

[0114] <Color conversion member> The color conversion member according to an embodiment of the present invention comprises a color conversion layer made of the color conversion composition of the present invention 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. The color conversion layer made of the color conversion composition of the present invention or a cured product thereof may itself be a color conversion member. One aspect of the color conversion member according to an 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.

[0115] 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.

[0116] The color conversion member according to the embodiment of the present invention may have a substrate and a barrier layer as needed, and may have two or more of these layers.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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 of the light conversion layer, or on one side.

[0121] 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. In this case, oxidation degradation of the light-emitting material due to singlet oxygen generated by a dye sensitization mechanism or the like can be suppressed, which is preferable. Furthermore, R １ ~R ６ In the case where the light-emitting material does not have a group containing a fluorine atom, in the absence of oxygen, R １ ~R ６ Since R in general formula (1) exhibits significantly better durability than light-emitting materials containing fluorine atoms, it is more preferable that the color conversion member has an oxygen barrier layer. １ ~R ６ is preferably not a group containing a fluorine atom. A light-emitting material without a group containing a fluorine atom has a high triplet excited level that easily reacts with surrounding molecules because the electron density of the pyrromethene skeleton is not low, and the probability of transition to the triplet excited state is low. Therefore, deterioration due to reaction between the triplet excited state and surrounding molecules is unlikely to occur.

[0122] Examples of the oxygen barrier layer 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. The oxygen barrier layer may contain two or more of these.

[0123] 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 the 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 the 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.

[0124] Another aspect of the color conversion member according to the 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 the recesses).

[0125] 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 ray blocking function, an ultraviolet ray blocking function, a polarizing function, or a color-tuning function, depending on the required function.

[0126] <Method for Manufacturing Color Conversion Member> The method for manufacturing 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 being heated and then molded using an extruder, and a method in which the color conversion composition is placed in a mold and molded by heating, cooling, drying, etc.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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 preferably 10 mJ / cm.２ ~10 J / cm ２ is preferred.

[0131] 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.

[0132] <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 member of the present invention. 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 in close contact with each other, or may be a remote phosphor type in which the light source and the color conversion member are separated from each other. Furthermore, a color filter may be further included to enhance 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 homogenize the emitted light. When the color conversion layer made of the color conversion composition of the present invention or a cured product thereof is itself the color conversion member, the arrangement of the light source and the color conversion layer made of the color conversion composition of the present invention or a cured product thereof is not particularly limited. The color conversion composition may be directly applied to the light source, or the color conversion composition may be applied to a film, glass, or the like separated from the light source.

[0133] One aspect of the light source unit according to the embodiment of the present invention includes 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, and a reflector may be provided below the light source.

[0134] 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.

[0135] 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.

[0136] <Light Source> Any light source can be used as long as it emits light in a wavelength region that can be absorbed by the light-emitting material used in the present invention. For example, any light source can be used in principle, 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.

[0137] 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.

[0138] 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 have one emission peak. It is also possible to use a combination of multiple light sources with different emission peaks.

[0139] <Display, Lighting Device> The display of the present invention includes at least the light source unit of the present invention. For example, a display such as a liquid crystal display uses the above-described light source unit as a backlight unit.

[0140] The lighting device of the present invention includes at least the light source unit of the present invention. For example, the lighting 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 into light with a longer wavelength.

[0141] 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.

[0142] < １ H-NMR Measurement of Compound １ H-NMR was measured using a superconducting FTNMR EX-270 (manufactured by JEOL Ltd.) in a deuterated chloroform solution.

[0143] <Measurement of Fluorescence Spectrum> The fluorescence spectrum of a compound was measured using an F-2500 spectrofluorometer (manufactured by Hitachi, Ltd.) by dissolving a luminescent material in toluene at 1 × 10 －６ The fluorescent spectrum was measured when the solution was dissolved at a concentration of 1000 mol / L and excited at a wavelength of 540 nm. The peak wavelength and half-width were determined from the obtained fluorescent spectrum. The results are shown in Table 1. The half-width of the spectrum was used as an index for evaluating color purity. A smaller half-width of the spectrum is preferable because it indicates higher color purity.

[0144] <Evaluation of Light Durability> A light-emitting device equipped with the color conversion member and blue LED (manufactured by USHIO EPITEX Corporation; model number SMBB450H-1100, emission peak wavelength: 450 nm) prepared in each example and comparative example was passed a current of 800 mA to light up the blue LED, and the initial emission peak intensity was measured using a spectroradiometer (CS-1000, manufactured by Konica Minolta). The distance between the color conversion member and the blue LED element was 3 cm. Thereafter, the color conversion member was continuously irradiated with light from the blue LED element in an environment of 50°C, and the light durability of the color conversion member was evaluated by observing the time until the emission peak intensity decreased by 5%.

[0145] (Synthesis Example 1) Method for synthesizing compound R-1 A mixed solution of 2-phenyl-4-(o-tolyl)pyrrole (2.33 g), 3,5-dichlorobenzoyl chloride (3.14 g), and o-xylene (5 mL) was heated and stirred under reflux under a nitrogen stream for 6 hours. Next, after cooling this mixed solution to room temperature, methanol was added, and the precipitated solid was filtered and dried under vacuum. This yielded 2-(3,5-dichlorobenzoyl)-3-(o-tolyl)-5-phenylpyrrole (3.80 g).

[0146] A mixed solution of 2-(3,5-dichlorobenzoyl)-3-(o-tolyl)-5-phenylpyrrole (3.60 g), spirofluorene indenopyrrole (3.00 g), methanesulfonic anhydride (5.08 g), and degassed toluene (45 mL) was heated at 50°C for 7 hours under a nitrogen stream. Next, diisopropylethylamine (3.50 mL) and boron trifluoride diethyl ether complex (7.68 mL) were added, and the mixture was stirred at 50°C for 1 hour. Subsequently, water (32 mL) was poured into the stirred mixed solution, and the organic layer was extracted. The obtained organic layer was washed twice with water (20 mL), dried over magnesium sulfate, and the solvent was removed from the organic layer using an evaporator. The residue was purified by silica gel column chromatography and dried under vacuum to obtain a dichloropyrromethene compound (4.00 g).

[0147] Dichloropyrromethene (0.75 g), 4-(methoxycarbonyl)phenylboronic acid (0.54 g), DabaPhos (0.02 g), and cesium fluoride (0.91 g) were placed in a flask, and THF (10 mL) and Pd(OAc) ２ (0.01 g) was added and stirred at 80°C for 4 hours under a nitrogen atmosphere. After completion of the reaction, water (20 mL) was added and stirred, and the organic layer was separated. This organic layer was dried over magnesium sulfate and filtered, and the solvent was distilled off. The resulting reaction product was purified by silica gel chromatography to obtain 0.85 g of compound R-1 (yield 90%).

[0148] １ H-NMR (CDCl3, ppm): δ1.93 (s, 3H), 3.14 (s, 6H), 5.96 (s, 1H), 6.13 (d, 1H), 6.20 (d, 1H), 6.50-6.58 (m, 3H), 6.63 (t, 1H), 6.84-7.00 (m, 5H), 7.09-7.20 (m, 3H), 7.29-7.40 (m, 3H), 7.49-7.58 (m, 3H), 7.62 (d, 4H), 7.75 (t, 2H), 7.70 (s, 2H), 8.02 (s, 1H), 8.12 (d, 4H).

[0149] ​Compounds other than those mentioned above can also be easily synthesized by changing various raw materials such as pyrrole raw material and benzoyl chloride raw material.

[0150] <Light-emitting materials> In the following examples and comparative examples, compounds R-1 to R-16 and R-101 to R-104 are the compounds shown below.

[0151]

[0152]

[0153]

[0154]

[0155] <Scattering Material> Titanium dioxide particles JR-301 (manufactured by Teika Co., Ltd.) were used as the scattering material.

[0156] Example 1 PMMA resin BR-85 (manufactured by Mitsubishi Chemical Corporation) was used as the binder resin. 0.03 parts by weight of compound R-1 as the luminescent material, 3 parts by weight of JR-301 as the scattering material, and 300 parts by weight of ethyl acetate as the solvent were mixed with 100 parts by weight of the binder resin. The mixture was then stirred and degassed at 1000 rpm for 20 minutes using a planetary stirring and degassing apparatus "MAZELSTAR" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.) to obtain a resin composition for producing a color conversion layer.

[0157] Next, the color-changing composition was applied to a substrate layer of "Lumirror" (registered trademark) U48 (manufactured by Toray Industries, Inc., thickness 50 μm) using a slit die coater, and heated and dried at 100°C for 20 minutes to form a color-changing layer with an average thickness of 16 μm.

[0158] When blue LED light was color-converted using this sheet-like color conversion member, high-color-purity red light was obtained with a peak wavelength of 628 nm and a half-width of the emission spectrum at the peak wavelength of 31 nm, when only the red light emission region was extracted. Furthermore, when light from a blue LED element was continuously irradiated in an environment of 50°C, the time until the emission peak intensity decreased by 5% was 620 hours, which was approximately 4.1 times longer than Comparative Example 1 described below.

[0159] Examples 2 to 16 Sheet-like color converting members were produced in the same manner as in Example 1, except that the luminescent material was changed to one shown in Table 1 and the amount of luminescent material mixed was adjusted to be the same as that of R-1 in Example 1. The results are shown in Table 1.

[0160] Comparative Examples 1 to 4 Sheet-shaped color converting members were produced in the same manner as in Example 1, except that the luminescent material was changed to one shown in Table 1 and the amount of the luminescent material mixed was adjusted to be the same as that of R-1 in Example 1. The results are shown in Table 1.

[0161]

[0162] REFERENCE SIGNS LIST 1 color conversion sheet 10, 10A, 10B base layer 11, 11A, 11B color conversion layer 12, 12A, 12B barrier film 13 intermediate layer

Claims

1. A pyrromethene boron complex represented by the following general formula (1): (In general formula (1), R １ ~R ６ may be the same or different and are selected from a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, a halogen atom, a cyano group, an aldehyde group, a carboxyl group, an ester group, an amide group, an acyl group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, a nitro group, a silyl group, a siloxanyl group, a boryl group, and a phosphine oxide group. １ and R ２ , R ２ and R ３ One of the two pairs is a ring structure of the following general formula (2): ７ is a group represented by the following general formula (3): ８ and R ９ may be the same or different and are selected from an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, a halogen atom, or a cyano group. (In general formula (2), R １０１ and R １０２ represents R in the general formula (1). １ ~R ６ Ar is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocycle. １０１ and R １０２ may form a ring. * indicates the linkage with the pyrromethene skeleton. (In general formula (3), L １ and L ２ is a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group. x and y are integers of 1 to 5. ２０１ is an electron-withdrawing group.) 2. R in the general formula (3) ２０１ is a fluorine atom, a fluorine-containing aryl group, a fluorine-containing heteroaryl group, a fluorine-containing alkyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted ester group, a substituted or unsubstituted amide group, a substituted or unsubstituted sulfonyl group, or a cyano group.

3. R ​​in the general formula (1) ４ and R ６ at least one of R in the general formula (3) is a fluorine atom, a fluorine-containing aryl group, a fluorine-containing heteroaryl group, or a fluorine-containing alkyl group; ２０１ The pyrromethene boron complex according to claim 1, wherein is an ester group or an acyl group.

4. In the general formula (3), L １ The pyrromethene boron complex according to claim 1, wherein is a substituted or unsubstituted arylene group.

5. In the general formula (3), L １ and L ２ The pyrromethene boron complex according to claim 4, wherein is a substituted or unsubstituted arylene group.

6. The pyrromethene boron complex according to claim 5, wherein x and y in the general formula (3) are integers of 1 to 3.

7. The pyrromethene boron complex according to claim 1, wherein Ar in the general formula (2) is a substituted or unsubstituted benzene ring.

8. R in the general formula (1) ４ ~R ６ The pyrromethene boron complex according to claim 1, wherein is a group that does not form a ring structure with an adjacent group.

9. R in the general formula (1) ８ and R ９ 2. The pyrromethene boron complex according to claim 1, wherein any one of the above is a fluorine atom.

10. R in the general formula (1) ８ and R ９ 2. The pyrromethene boron complex according to claim 1, wherein any one of the above is a cyano group.

11. The pyrromethene boron complex according to claim 1, which exhibits luminescence with a peak wavelength observed in the region of 580 nm or more and less than 750 nm when excited with light.

12. A color-changing composition that converts incident light into light having a longer wavelength than the incident light, comprising the pyrromethene boron complex according to any one of claims 1 to 11 and a binder resin.

13. A color-changing member comprising a color-changing layer made of the color-changing composition according to claim 12 or a cured product thereof.

14. A light source unit comprising a light source and the color conversion member according to claim 13.

15. A display comprising the light source unit according to claim 14.

16. A lighting device comprising the light source unit according to claim 14.

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