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

Abstract

A pyrromethene boron complex as one embodiment of the present invention is a compound represented by general formula (1). In the general formula (1), X is C-R7 or N. And R1 and R3 are aryl groups different from each other. R2 and R4-R9 may be the same as or different from each other; and a compound selected from the group consisting of 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 sulfide group, an aryl group, a heteroaryl group, a halogen, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxane group, a boryl group, and a phosphine oxide group. Wherein one of the group of R4 and R5 and the group of R5 and R6 has a ring structure represented by any one of general formulae (2A)-(2D). In general formulae (2A) to (2D), R101, R102, and R201 to R204 are the same as R2 and R4-R9 in general formula (1). Ar represents a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring. In addition, R101 and R102 may form a ring. * represents a linking part to a pyrromethene skeleton. [Chemical Formula 1] # imgabs0 # [Chemical Formula 2] # imgabs1 #

Description

Technical Field

[0001] The present invention relates to a pyrromethene boron complex, a color conversion composition, a color conversion sheet, a color conversion substrate, a light source unit, a display device and a lighting device. Background Art

[0002] The application of multicolorization technology based on color conversion in liquid crystal displays, organic EL displays, lighting devices, etc. is actively studied. Color conversion means converting the light emitted from a light emitter into light with a longer wavelength. For example, as color conversion, blue light emission can be converted into green light emission, red light emission, etc.

[0003] By forming the composition having a color conversion function (hereinafter referred to as the color conversion composition) into a sheet and combining it with, for example, a blue light source, the three primary colors of blue, green, and red can be obtained from the blue light source, that is, white light can be obtained. By using such a white light source composed of a blue light source and a sheet having a color conversion function (hereinafter referred to as a color conversion sheet) as a light source unit such as a backlight unit, and combining the light source unit, a liquid crystal drive unit, and a color filter, a full-color display can be produced. In addition, the white light source combined with the blue light source and the color conversion sheet can also be directly used as a white light source for LED lighting, etc.

[0004] As a subject of display devices such as liquid crystal displays that utilize a color conversion method, the improvement of color reproducibility can be cited. In order to improve color reproducibility, it is effective to narrow the half-value width of each emission spectrum of blue, green, and red of the light source unit to improve the color purity of each color of blue, green, and red. As a means to solve this problem, for example, a technology using a pyrromethene compound as a component of a color conversion composition has been proposed (for example, see patent documents 1 to 2). In addition, as a technology for further improving color purity, a compound formed by introducing a condensed ring structure into a pyrromethene skeleton is known (for example, see patent document 3).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2010-61824

[0008] Patent Document 2: Japanese Patent Application Publication No. 2014-136771

[0009] Patent Document 3: International Publication No. 2020 / 045242 Summary of the invention

[0010] Problems to be solved by the invention

[0011] However, it is known that the techniques described in Patent Documents 1 to 3 have a problem of insufficient fluorescence quantum yield.

[0012] The present invention is made in view of the above situation, and the first object is to provide a pyrromethene boron complex having excellent color purity and capable of obtaining a high fluorescence quantum yield. In addition, the second object of the present invention is to provide a color conversion composition, a color conversion sheet, a color conversion substrate, a light source unit, a display device, and a lighting device using the pyrromethene boron complex.

[0013] Means for solving problems

[0014] In order to solve the above-mentioned problems and achieve the purpose, the present invention adopts the structure described in any one of the following [1] to

[17] .

[0015] That is, the pyrromethene boron complex according to the present invention is characterized in that [1] is a compound represented by the following general formula (1).

[0016] [Chemical formula 1]

[0017]

[0018] (In the general formula (1), X is CR 7 or N. R 1 and R 3 are different aromatic groups. 2 and R 4 ~R 9 may be the same or different, and are selected from the group consisting of 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 group, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxane group, a boron group, and a phosphine oxide group. 4 With R 5 The group, and R 5 With R 6 One of the two groups is a ring structure represented by any one of the following general formulae (2A) to (2D).

[0019] [Chemical formula 2]

[0020]

[0021] (In general formulas (2A) to (2D), R 101 , R 102 and R 201 ~R 204 and R in the above general formula (1) 2 and R 4 ~R9 Ar is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocyclic ring. 101 With R 102 A ring can be formed. * indicates the connection part with the pyrromethene skeleton.)

[0022] The pyrromethene boron complex according to the present invention is characterized in that [2] in the invention according to [1] above, the compound represented by the general formula (1) is a compound represented by any one of the following general formulas (3A) to (3D).

[0023] [Chemical formula 3]

[0024]

[0025] (In general formulas (3A) to (3D), R 101 and R 102 and R in the above general formula (1) 2 and R 4 ~R 9 Ar is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocyclic ring. 101 With R 102 Can form a ring.)

[0026] In addition, the pyrromethene boron complex according to the present invention is characterized in that [3] in the invention described in [1] or [2] above, the Ar is a substituted or unsubstituted benzene ring.

[0027] In addition, the pyrromethene boron complex of the present invention is characterized in that: [4] in the invention described in any one of [1] to [3] above, R in the general formula (1) is 1 and R 3 are different substituted or unsubstituted phenyl groups.

[0028] In addition, the pyrromethene boron complex of the present invention is characterized in that [5] in the invention described in any one of [1] to [4] above, R in the general formula (1) 1 It is a phenyl group having a substituent at the ortho position.

[0029] In addition, the pyrromethene boron complex of the present invention is characterized in that [6] in the invention described in any one of [1] to [5] above, R in the general formulas (1) and (2A) to (2D) is 1 ~R 3 , R 101 , R 102 , R 201 ~R 204At least one of R and Ar is a group including an electron withdrawing group.

[0030] In addition, the pyrromethene boron complex of the present invention is characterized in that: [7] in the invention described in any one of [1] to [6], R in the general formula (1) is 1 ~R 3 At least one of the groups is a group comprising an electron withdrawing group.

[0031] In addition, the pyrromethene boron complex of the present invention is characterized in that, [8] in the invention described in any one of [1] to [7] above, the electron withdrawing group is fluorine, a fluorine-containing aromatic group, a fluorine-containing heteroaromatic 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.

[0032] In addition, the pyrromethene boron complex of the present invention is characterized in that: [9] in the invention described in any one of [1] to [8] above, in the general formula (1), X is CR 7 , R 7 It is a group represented by the following general formula (4).

[0033] [Chemical formula 4]

[0034]

[0035] (In the general formula (4), r is selected from the group consisting of 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, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxane group, a boron group, and a phosphine oxide group. k is an integer of 1 to 3. When k is 2 or more, r may be the same or different.)

[0036] In addition, the pyrromethene boron complex of the present invention is characterized in that,

[10] in any one of the inventions [1] to [9] above, the compound represented by the general formula (1) exhibits luminescence with a peak wavelength observed in the region of 580 nm to 750 nm by using excitation light.

[0037] In addition, the color conversion composition according to the present invention is characterized in that

[11] it is a color conversion composition that converts incident light into light having a wavelength longer than that of the incident light, and comprises the pyrromethene boron complex described in any one of [1] to

[10] above and a binder resin.

[0038] Furthermore, the color conversion sheet according to the present invention is characterized by

[12] comprising a color conversion layer formed of the color conversion composition according to

[11] above or a cured product thereof.

[0039] In addition, the color conversion substrate according to the present invention is characterized in that

[13] it is a color conversion substrate having a plurality of color conversion layers on a transparent substrate, wherein the plurality of color conversion layers are layers formed of the color conversion composition described in

[11] above or a cured product thereof.

[0040] In addition, the light source unit according to the present invention is characterized in that

[14] includes a light source and the color conversion sheet described in

[12] or the color conversion substrate described in

[13] .

[0041] In addition, the light source unit according to the present invention is characterized in that

[15] in the invention described in

[14] above, the light source is a light emitting diode having a maximum light emission within a wavelength range of not less than 430 nm and not more than 500 nm.

[0042] In addition, the display device according to the present invention is characterized in that

[16] includes the color conversion sheet described in

[12] or the color conversion substrate described in

[13] .

[0043] In addition, the lighting device according to the present invention is characterized in that

[17] it includes the color conversion sheet described in

[12] or the color conversion substrate described in

[13] .

[0044] Effects of the Invention

[0045] According to the present invention, a pyrromethene boron complex having excellent color purity and high fluorescence quantum yield can be provided. The pyrromethene boron complex can provide a color conversion composition, a color conversion sheet, and a color conversion substrate having high fluorescence quantum yield and high color purity (for example, red light emission), and can improve the color reproducibility of a light source unit, a display device such as a liquid crystal display, and a lighting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] [ Figure 1 ] Figure 1 This is a schematic cross-sectional view showing a first example of a color conversion sheet according to an embodiment of the present invention.

[0047] [ Figure 2 ] Figure 2 This is a schematic cross-sectional view showing a second example of the color conversion sheet according to the embodiment of the present invention.

[0048] [ Figure 3 ] Figure 3 It is a schematic cross-sectional view showing a third example of the color conversion sheet according to the embodiment of the present invention.

[0049] [ Figure 4 ] Figure 4 It is a schematic cross-sectional view showing a fourth example of the color conversion sheet according to the embodiment of the present invention. DETAILED DESCRIPTION

[0050] Hereinafter, preferred embodiments of the pyrromethene boron complex, the color conversion composition using the same, the color conversion sheet, the color conversion substrate, the light source unit, the display device, and the lighting device according to the present invention will be specifically described. However, the present invention is not limited to the following embodiments and can be implemented with various modifications according to the purpose and application.

[0051] (Pyrromethene boron complex)

[0052] The pyrromethene boron complex according to an embodiment of the present invention (hereinafter, sometimes simply referred to as the pyrromethene boron complex of the present invention) will be described in detail. The pyrromethene boron complex of the present invention is a compound represented by the following general formula (1).

[0053] [Chemical formula 5]

[0054]

[0055] In the general formula (1), X is CR 7 or N. R 1 and R 3 are different aromatic groups. 2 and R 4 ~R 9 may be the same or different, and are selected from the group consisting of 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 group, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxane group, a boron group, and a phosphine oxide group. 4 With R 5 The group, and R 5 With R 6 One of the two groups is a ring structure represented by any one of the following general formulae (2A) to (2D).

[0056] [Chemical formula 6]

[0057]

[0058] In the general formulas (2A) to (2D), R 101 , R 102 and R 201 ~R 204 With R in the general formula (1)2 and R 4 ~R 9 Ar is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocyclic ring. 101 With R 102 A ring may be formed. "*" in the general formulae (2A) to (2D) represents a linking portion to the pyrromethene skeleton.

[0059] In all the above groups, hydrogen may be deuterium. This also applies to the compounds described below or their partial structures. In the following description, for example, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms refers to an aryl group having 6 to 40 carbon atoms, including the carbon atoms contained in the substituent substituted in the aryl group. The same applies to other substituents with specified carbon atoms.

[0060] In addition, among all the above-mentioned groups, as the substituent in the case of being substituted, preferably 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, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxane group, a boron group, a phosphine oxide group, and more preferably a specific substituent preferred in the description of each substituent. In addition, these substituents may be further substituted by the above-mentioned substituents.

[0061] The "unsubstituted" in the case of "substituted or unsubstituted" means that a hydrogen atom or a deuterium atom is substituted. In the compounds or partial structures described below, the case of "substituted or unsubstituted" is the same as above.

[0062] The alkyl in the above-mentioned all groups, for example, represents a saturated aliphatic hydrocarbon group such as a methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl group, which may or may not have a substituent. There is no particular restriction on the additional substituent in the case of being substituted, for example, an alkyl, a halogen, an aryl, a heteroaryl, etc. can be cited, and this point is also universal in the following description. In addition, the carbon number of the alkyl is not particularly limited, and from the aspect of the ease of obtaining and the cost, it is preferably in the range of 1 to 20, more preferably in the range of 1 to 8.

[0063] The cycloalkyl group refers to a saturated alicyclic hydrocarbon group such as cyclopropyl, cyclohexyl, norbornyl, adamantyl, etc., which may or may not have a substituent. The number of carbon atoms in the alkyl part is not particularly limited, but is preferably within the range of 3 or more and 20 or less.

[0064] The so-called heterocyclic group refers to an aliphatic ring having atoms other than carbon in the ring, such as a pyran ring, a piperidine ring, a cyclic amide, etc., 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.

[0065] The alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as a vinyl group, an allyl group, and 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 within the range of 2 or more and 20 or less.

[0066] The cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond, such as cyclopentenyl, cyclopentadienyl, and cyclohexenyl, which may or may not have a substituent. The number of carbon atoms in the cycloalkenyl group is not particularly limited, but is preferably within the range of 3 or more and 20 or less.

[0067] 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 within the range of 2 or more and 20 or less.

[0068] The so-called alkoxy group refers to a functional group such as methoxy, ethoxy, propoxy, etc., to which an aliphatic hydrocarbon group is bonded via an ether bond, and the 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.

[0069] The so-called alkylthio group refers to a group in which the oxygen atom of the ether bond of the alkoxy group is replaced by 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.

[0070] 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 within a range of 6 to 40.

[0071] The so-called aryl thioether group refers to a group in which the oxygen atom of the ether bond of the aryl ether group is replaced by 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 or more and 40 or less.

[0072] The aryl group includes, for example, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthryl, anthracenyl, triphenylenyl, benzanthryl, The aromatic hydrocarbon groups such as phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl, anthracenyl, pyrenyl, fluoranthenyl, triphenylene, benzofluoranthenyl, dibenzoanthryl, perylene, spiroenyl are preferred. Among them, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl, anthracenyl, pyrenyl, fluoranthenyl, triphenylene. 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, and more preferably in the range of 6 to 30.

[0073] R in the general formula (1) 2 and R 4 ~R 9 In the case of a substituted or unsubstituted aryl group, the aryl group is preferably phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl, anthracenyl, more preferably phenyl, biphenyl, terphenyl, naphthyl, further preferably phenyl, biphenyl, terphenyl, particularly preferably phenyl.

[0074] When each substituent 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.

[0075] The so-called heteroaryl group refers to a cyclic aromatic group having atoms other than carbon in one or more rings, such as pyridyl, furyl, thienyl, quinolyl, isoquinolyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, naphthyridinyl, cinnolinyl, phthalazinyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothienyl, indolyl, dibenzofuranyl, dibenzothienyl, carbazolyl, benzocarbazolyl, carbolyl, indolecarbazolyl, benzofuranocarbazolyl, benzothiophenocarbazolyl, dihydroindenocarbazolyl, benzoquinolyl, acridinyl, dibenzoacridinyl, benzimidazolyl, imidazopyridinyl, benzoxazolyl, benzothiazolyl, and phenanthrolinyl. Among them, naphthyridinyl represents any one of 1,5-naphthyridinyl, 1,6-naphthyridinyl, 1,7-naphthyridinyl, 1,8-naphthyridinyl, 2,6-naphthyridinyl, and 2,7-naphthyridinyl. 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 to 40, and more preferably in the range of 2 to 30.

[0076] R in the general formula (1) 2 and R 4 ~R 9In the case of a substituted or unsubstituted heteroaryl group, the heteroaryl group is preferably a pyridyl group, a furyl group, a thienyl group, a quinolyl group, a pyrimidinyl group, a triazine 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, a phenanthroline group, more preferably a pyridyl group, a furyl group, a thienyl group, a quinolyl group. A pyridyl group is particularly preferred.

[0077] When each substituent is further substituted by a heteroaryl group, as the heteroaryl group, preferably a pyridyl group, a furyl group, a thienyl group, a quinolyl group, a pyrimidyl group, a triazine 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, a phenanthroline group, more preferably a pyridyl group, a furyl group, a thienyl group, a quinolyl group. Especially preferably, a pyridyl group is used.

[0078] The so-called halogen refers to an atom selected from fluorine, chlorine, bromine and iodine. In addition, the carbonyl group, carboxyl group, oxycarbonyl group and carbamoyl group may or may not have a substituent. Here, as the substituent, for example, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group and the like can be cited, and these substituents may be further substituted.

[0079] The amino group refers to a substituted or unsubstituted amino group. The amino group may or may not have a substituent. For example, an aryl group, a heteroaryl group, a straight-chain alkyl group, and a branched-chain alkyl group may be used as the substituent. As the aryl group and the heteroaryl group, a phenyl group, a naphthyl group, a pyridyl group, and a quinolyl 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 in the range of 6 to 40, and particularly preferably in the range of 6 to 30.

[0080] The so-called silyl group refers to, for example, alkyl silyl groups such as trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, propyldimethylsilyl, and vinyldimethylsilyl, and aryl silyl 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.

[0081] The so-called siloxane group refers to a silicon compound group formed via an ether bond, such as a trimethylsiloxane group. The substituent on silicon may be further substituted. In addition, the so-called boron group refers to a substituted or unsubstituted boron group. The boron group may have a substituent or may not have a substituent. As the substituent in the case of substitution, for example, an aryl group, a heteroaryl group, a straight-chain alkyl group, a branched alkyl group, an aryl ether group, an alkoxy group, and a hydroxyl group can be cited, among which an aryl group and an aryl ether group are preferred. In addition, a phosphine oxide group refers to -P(=O)R 10 R 11 The group shown. R of the phosphine oxide group 10 and R 11 is selected from R in the general formula (1) 2 and R 4 ~R 9 Same group.

[0082] The compound represented by the general formula (1) has a pyrromethene boron complex skeleton. The pyrromethene boron complex skeleton is a strong and highly planar skeleton. Therefore, the compound represented by the general formula (1) having a pyrromethene boron complex skeleton shows a high fluorescence quantum yield. In addition, for the compound represented by the general formula (1), the peak half-value width of the luminescence spectrum is small, so it is possible to achieve efficient luminescence, that is, an increase in fluorescence quantum yield and high color purity.

[0083] Usually, when using pyrromethene boron complex to make the light emitting in longer wavelength region than green, pyrromethene boron complex is directly bonded to pyrromethene boron complex skeleton by making the group with double bond be bonded to pyrromethene boron complex skeleton, so that conjugation is extended and the luminescent wavelength is lengthened. However, if only the group with double bond is simply bonded to pyrromethene boron complex skeleton, pyrromethene boron complex can be converted into a variety of stable structures (hereinafter, this phenomenon is referred to as "structural relaxation") in its excited state, so it is accompanied by luminescence from various energy states and deactivation. In this case, the luminescent spectrum is broadened, the half-value width becomes larger, and the color purity decreases. That is, in order to realize long wavelength using pyrromethene boron complex, it is necessary to study on molecular design.

[0084] The pyrromethene boron complex of the present invention is a compound represented by the general formula (1), and has a ring structure represented by any one of the general formulas (2A) to (2D) on the pyrromethene boron complex skeleton. Each ring structure represented by the general formulas (2A) to (2D) has a double bond, and the double bond must be fixed to the pyrromethene boron complex skeleton in the form of a chemical bond through a carbon atom. As a result, excessive structural relaxation in the excited state can be suppressed, so the luminescence spectrum of the compound represented by the general formula (1) becomes sharp. When the compound is used in a luminescent material, luminescence with good color purity can be obtained. That is, when the compound represented by the general formula (1) is used in a color conversion composition, a larger color gamut can be efficiently constructed, and color reproducibility is improved.

[0085] In the pyrromethene boron complex of the present invention, R in the general formula (1) 1 and R 3 are different aromatic groups. 1 and R 3 The aryl groups are different from each other, and the dispersibility of the pyrromethene boron complex is improved, and concentration quenching can be suppressed. Therefore, the fluorescence quantum yield is improved.

[0086] In the present invention, the so-called different aryl groups include, for example, phenyl and naphthyl groups having different carbon skeletons; phenyl and tolyl groups, or tert-butylphenyl and methoxyphenyl groups having the same carbon skeleton but different substituents or different types. In the case where the carbon skeletons of the aryl groups are the same but the substituents are different, the dispersibility of the pyrromethene boron complex is further improved, which is more preferred.

[0087] In the compound represented by the general formula (1), except for R 1 and R 3 Except for being different aromatic groups, R 4 With R 5 The group, and R 5 With R 6 One of the two groups is a ring structure represented by any one of the general formulae (2A) to (2D). Thus, sharp luminescence is obtained while maintaining a certain degree of Stokes shift. The reason is that the compound represented by the general formula (1) undergoes moderate structural relaxation during the process of being excited and emitting light. The so-called Stokes shift refers to the difference between the maximum absorption wavelength and the maximum fluorescence wavelength.

[0088] In a color conversion sheet that converts wavelength by absorbing light in a specific wavelength band (e.g., excitation light, etc.) and emitting light in a target wavelength band, if the absorption spectrum of the specific wavelength band overlaps the emission spectrum of the target wavelength band, reabsorption occurs, in which the emitted light is absorbed again. As a result, the luminous efficiency of the color conversion sheet decreases. Therefore, from the viewpoint of luminous efficiency, it is preferred that the Stokes shift is large and the overlap between the absorption spectrum and the emission spectrum is small.

[0089] In the pyrromethene boron complex, if the structural relaxation is excessively suppressed, the Stokes shift will be excessively reduced, so the luminous efficiency will decrease. Therefore, in order to have high color purity and high brightness, it is important to allow the pyrromethene boron complex to undergo appropriate structural relaxation when it is excited to emit light. In the compound represented by the general formula (1) (pyrromethene boron complex), R 4 With R 5 The group and R 5 With R 6 One of the two groups is a ring structure represented by any one of the general formulae (2A) to (2D), R 1 and R 3 Therefore, the pyrromethene boron complex undergoes moderate structural relaxation during the luminescence process, so the peak half-value width of the luminescence spectrum is small and has high brightness.

[0090] Furthermore, the compound represented by the general formula (1) can adjust various characteristics and properties such as luminous efficiency, color purity, thermal stability, light stability and dispersibility by introducing appropriate substituents at appropriate positions.

[0091] For example, the compound represented by the general formula (1) is preferably a compound represented by any one of the following general formulae (3A) to (3D).

[0092] [Chemical formula 7]

[0093]

[0094] In the general formulas (3A) to (3D), X is CR 7 or N. R 101 and R 102 In the above general formula (1), R 2 and R 4 ~R 9 Ar is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocyclic ring. 101 With R 102 A ring can be formed.

[0095] In each of the compound represented by general formula (3A), the compound represented by general formula (3B), the compound represented by general formula (3C), and the compound represented by general formula (3D), conjugation is efficiently extended, and thus light emission with a longer wavelength and high color purity can be achieved.

[0096] In general formula (1) (specifically, general formula (2D)) and general formulas (3A) to (3D), 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. In addition, when Ar is a substituted or unsubstituted benzene ring, thermal stability and electrical stability are improved, so it is particularly preferred.

[0097] In the pyrromethene boron complex of the present invention, R in the general formula (1) 1 and R 3 The phenyl groups are preferably different from each other in terms of substituted or unsubstituted phenyl groups. This is because, with this structure, the compound represented by the general formula (1) exhibits better thermal stability and light stability.

[0098] In the pyrromethene boron complex of the present invention, R in the general formula (1) 1 The phenyl group having a substituent at the ortho position is preferred. 1 The phenyl group has a substituent at the ortho position, so that the intramolecular rotation in the excited state is suppressed, and a light emission spectrum with a small half-value width can be obtained. 1 The phenyl group having a substituent at the ortho position improves the dispersibility of the pyrromethene boron complex, thereby improving the fluorescence quantum yield.

[0099] In particular, in the pyrromethene boron complex of the present invention, R in the general formula (1) 1 and R 3 are different substituted or unsubstituted phenyl groups, and the R 1 A phenyl group having a substituent at the ortho position is more preferred.

[0100] In the pyrromethene boron complex of the present invention, it is preferred that R 1 ~R 3 , R 101 , R 102 , R 201 ~R 204 At least one of R and Ar is a group containing an electron-withdrawing group. The reason is that the electron-withdrawing group moderately causes structural relaxation of the compound represented by the general formula (1) in an excited state, and the Stokes shift becomes larger, thereby further improving the luminous efficiency. 1 ~R3 When at least one of the groups is a group containing an electron withdrawing group, structural relaxation becomes greater, which is particularly preferred.

[0101] The so-called electron withdrawing group, also known as an electron accepting group, is an atomic group that attracts electrons from a substituted atomic group by an inductive effect or a resonance effect in organic electronic theory. Examples of electron withdrawing groups include electron withdrawing groups whose substituent constant (σp (para)) according to Hammett's rule takes a positive value. The substituent constant (σp (para)) according to Hammett's rule can be cited from the fifth revised edition of the Chemistry Handbook (page II-380).

[0102] Examples of electron withdrawing groups include -F (σp: +0.06), -Cl (σp: +0.23), -Br (σp: +0.23), -I (σp: +0.18), -CO2R 12 (σp:R 12 When it is ethyl, +0.45), -CONH2 (σp: +0.38), -COR 12 (σp:R 12 When it is methyl, +0.49), -CF3 (σp: +0.50), -SO2R 12 (σp:R 12 When it is methyl, +0.69), -NO2 (σp: +0.81), etc. 12 Each independently represents a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring-forming 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 described above.

[0103] Preferred electron-withdrawing groups include fluorine, fluorine-containing aryl groups, fluorine-containing heteroaryl groups, fluorine-containing alkyl groups, substituted or unsubstituted acyl groups, substituted or unsubstituted ester groups, substituted or unsubstituted amide groups, substituted or unsubstituted sulfonyl groups, or cyano groups, because they are not easily chemically decomposed.

[0104] In the pyrromethene boron complex of the present invention, X in the general formula (1) is CR 7 , and the R 7 The group represented by the following general formula (4) is preferred because it can provide bulk to the compound represented by the general formula (1) and improve the luminous efficiency.

[0105] [Chemical formula 8]

[0106]

[0107] In the general formula (4), r is selected from the group consisting of 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, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxane group, a boron group, and a phosphine oxide group. k is an integer of 1 to 3. When k is 2 or more, r may be the same or different.

[0108] In the general formula (4), r is preferably a substituted or unsubstituted aryl group. Among the aryl groups, phenyl and naphthyl can be mentioned as preferred examples. When r is an aryl group, k in the general formula (4) is preferably 1 or 2, and more preferably 2. It is further preferred that at least one of the r is substituted by an alkyl group or an aryl group. As the alkyl group in this case, methyl, ethyl and tert-butyl can be mentioned as particularly preferred examples. In addition, when r is an aryl group, phenyl and naphthyl are preferably used as the aryl group. These aryl groups can be further substituted by an alkyl group, a heterocyclic group, an alkenyl group, a hydroxyl group, an alkoxy group, an aryl ether group, an aryl group, a heteroaryl group, a halogen group, a cyano group, a carboxyl group, an ester group, an oxycarbonyl group, and an alkoxy group.

[0109] In addition, from the viewpoint of controlling the fluorescence wavelength, the absorption wavelength, or improving the compatibility with the solvent, the r in the general formula (4) is preferably a substituted or unsubstituted alkyl, a substituted or unsubstituted alkoxy or a halogen. Among these, a methyl, an ethyl, a tert-butyl, or a methoxy group is more preferred. From the viewpoint of dispersibility, the r is particularly preferably a tert-butyl or a methoxy group. Thus, the quenching caused by the aggregation of molecules can be prevented.

[0110] An example of the compound represented by the general formula (1) is shown below, but the pyrromethene boron complex of the present invention is not limited to these.

[0111] [Chemical formula 9]

[0112]

[0113] [Chemical formula 10]

[0114]

[0115] [Chemical formula 11]

[0116]

[0117] Regarding the synthesis of the pyrromethene boron complex of the present invention, the compound represented by the general formula (1) can be synthesized with reference to the methods described in J. Org. Chem., Vol. 64, No. 21, pp7813-7819 (1999), Angew. Chem., Int. Ed. Engl., vol. 36, pp1333-1335 (1997), etc. For example, the following method can be cited: after heating the compound represented by the following general formula (5) and the compound represented by the general formula (6) in 1,2-dichloroethane in the presence of phosphorus oxychloride, the compound represented by the following general formula (7) is reacted in 1,2-dichloroethane in the presence of triethylamine, thereby obtaining the compound represented by the general formula (1). However, the pyrromethene boron complex of the present invention is not limited thereto. Here, R 1 ~R 9 The same as the above description. J represents a halogen.

[0118] [Chemical formula 12]

[0119]

[0120] In addition, when introducing an aryl group or heteroaryl group, a method of generating a carbon-carbon bond by a coupling reaction of a halogenated derivative with a boric acid or borate ester derivative can be cited, but the pyrromethene boron complex of the present invention is not limited thereto. Similarly, when introducing an amino group or a carbazole group, for example, a method of generating a carbon-nitrogen bond by a coupling reaction of a halogenated derivative with ammonia or a carbazole derivative under a metal catalyst such as palladium can be cited, but the pyrromethene boron complex of the present invention is not limited thereto.

[0121] The pyrromethene boron complex of the present invention preferably uses excitation light to exhibit luminescence with a peak wavelength observed in a region of 580 nm or more and 750 nm or less. Hereinafter, luminescence with a peak wavelength observed in a region of 580 nm or more and 750 nm or less is sometimes referred to as "red luminescence". Generally, with respect to the excitation light, the higher its energy, the easier it is to cause the decomposition of the luminescent material. However, the excitation light in the range of a wavelength of 430 nm or more and 500 nm or less is light with a smaller excitation energy. Therefore, it is possible to obtain red luminescence with good color purity without causing the decomposition of the luminescent material. As a method for measuring the fluorescence spectrum, a method of dissolving a compound in an organic solvent such as toluene, exciting the compound using an excitation light with a wavelength in the range of 430 nm or more and 500 nm or less, and measuring the fluorescence spectrum at this time, etc. can be cited.

[0122] (Color conversion composition)

[0123] The color conversion composition according to an embodiment of the present invention (hereinafter, sometimes referred to as the color conversion composition of the present invention) is described in detail. The color conversion composition of the present invention converts incident light from a light source or other luminous body into light having a longer wavelength than the incident light, and preferably comprises the above-mentioned pyrromethene boron complex of the present invention and a binder resin described below.

[0124] In addition to the above-mentioned pyrromethene boron complex of the present invention, the color conversion composition of the present invention may also contain other compounds as needed. For example, in order to further improve the energy transfer efficiency from the excitation light to the pyrromethene boron complex of the present invention, the color conversion composition of the present invention may contain auxiliary dopants such as rubrene. In addition, in the case of wanting to increase the luminescent color other than the luminescent color based on the pyrromethene boron complex of the present invention, the desired organic luminescent material may be added, such as organic luminescent materials such as coumarin derivatives and rhodamine derivatives. In addition, known luminescent materials such as inorganic phosphors, fluorescent pigments, fluorescent dyes, and quantum dots may also be added in combination with organic luminescent materials other than organic luminescent materials. An example of an organic luminescent material other than the pyrromethene boron complex of the present invention is shown below, but the present invention is not particularly limited to these.

[0125] [Chemical formula 13]

[0126]

[0127] In the present invention, the color conversion composition preferably emits light having a peak wavelength observed in a region of 500 nm to less than 580 nm by using excitation light (green light emission). In addition, the color conversion composition preferably emits light having a peak wavelength observed in a region of 580 nm to 750 nm by using excitation light (red light emission).

[0128] That is, the color conversion composition of the present invention preferably contains the following luminescent material (a) and luminescent material (b). The luminescent material (a) is a luminescent material that exhibits luminescence with a peak wavelength observed in a region of 500 nm or more and less than 580 nm by using excitation light. The luminescent material (b) is a luminescent material that exhibits luminescence with a peak wavelength observed in a region of 580 nm or more and 750 nm or less by being excited by at least one of the excitation light or the luminescence from the luminescent material (a). Preferably, at least one of these luminescent materials (a) and luminescent materials (b) is the pyrromethene boron complex of the present invention, and more preferably, the luminescent material (b) is the pyrromethene boron complex of the present invention. That is, the compound represented by the above-mentioned general formula (1) more preferably exhibits luminescence with a peak wavelength observed in a region of 580 nm or more and 750 nm or less by using excitation light. In addition, as the above-mentioned excitation light, it is more preferable to use excitation light with a wavelength in the range of 430 nm or more and 500 nm or less.

[0129] A portion of the excitation light in the wavelength range of 430 nm to 500 nm partially transmits the color conversion sheet according to the embodiment of the present invention, so when a blue LED with a sharp emission peak is used, white light having an emission spectrum showing a sharp shape in each of the blue, green, and red colors can be obtained. As a result, a more vivid and wider color gamut can be efficiently formed, especially in display devices such as displays. That is, a display device with excellent color reproduction can be obtained. In addition, in lighting applications, compared with the white LED that is currently a combination of a blue LED and a yellow phosphor, the emission characteristics in the green and red regions are improved, so a preferred white light source with improved color rendering can be obtained.

[0130] As the luminescent material (a) and the luminescent material (b), known substances can be used respectively. For example, from the perspective of providing high luminescent quantum yield and showing luminescence with high color purity, pyrromethene derivatives are particularly preferred compounds. Among the pyrromethene derivatives, the durability of the pyrromethene boron complex of the present invention is greatly improved, so it is preferred.

[0131] In addition, when both the luminescent material (a) and the luminescent material (b) are the pyrromethene boron complex of the present invention, high-efficiency luminescence, high color purity, and high durability can be achieved simultaneously, which is preferred. The color conversion composition of the present invention preferably emits luminescence with a peak wavelength observed in the region of 580 nm to 750 nm by using excitation light.

[0132] The content of the pyrromethene boron complex (the compound represented by the general formula (1)) contained in the color conversion composition of the present invention varies depending on the molar absorption coefficient, luminescence quantum yield and absorption intensity at the excitation wavelength of the pyrromethene boron complex, as well as the thickness and transmittance of the color conversion sheet to be produced. Generally, it is 1.0×10 -4 The content of the pyrromethene boron complex is more preferably 1.0×10 -3 Parts by mass to 10 parts by mass, particularly preferably 1.0×10 -2 Parts by mass to 5 parts by mass.

[0133] (Binder resin)

[0134] The color conversion composition of the present invention preferably contains a binder resin in addition to the pyrromethene boron complex of the present invention. The binder resin is a resin that forms a continuous phase and is preferably a material excellent in molding processability, transparency, heat resistance, etc. Examples of such binder resins include photocurable resist materials having reactive vinyl groups such as acrylic, methacrylic, polyvinyl cinnamate, polyimide, and cyclorubber resins, epoxy resins, silicone resins (including cured (crosslinked) organic polysiloxanes such as silicone rubber and silica gel), urea resins, fluororesins, polycarbonate resins, acrylic resins, methacrylic resins, polyimide resins, cyclic olefin resins, polyethylene terephthalate resins, polypropylene resins, polystyrene 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, aromatic polyolefin resins, hydrogenated styrene resins, resins having a fluorene skeleton in a repeating unit, and copolymers thereof. The color conversion composition of the present invention may contain two or more of these as binder resins.

[0135] Among these resins, epoxy resins, silicone resins, acrylic resins, and ester resins are preferably used from the viewpoint of transparency, and acrylic resins and ester resins are more preferably used from the viewpoint of heat resistance.

[0136] These resins can be obtained, for example, by copolymerizing the raw material monomers in the presence of a polymerization initiator. In addition, commercially available products can also be used as the binder resin.

[0137] Among the above-mentioned binder resins, for example, the silicone resin may be any of a thermosetting silicone resin and a thermoplastic silicone resin. Thermosetting silicone resins cure at room temperature or at a temperature of 50 to 200°C, and have excellent transparency, heat resistance, and adhesion. As a thermosetting silicone resin, commercially available thermosetting silicone resins may also be used, for example, silicone sealing materials for conventional LED applications. Specific examples thereof include OE-6630A / B, OE-6336A / B manufactured by DuPont Toray Specialty Materials KK, SCR-1012A / B, SCR-1016A / B manufactured by Shin-Etsu Chemical Co., Ltd., and the like. As a thermoplastic silicone resin, commercially available thermoplastic silicone resins may be cited, for example, RSN series such as RSN-0805 and RSN-0217 manufactured by DuPont Toray Specialty Materials KK.

[0138] (Other ingredients)

[0139] The color conversion composition of the present invention may contain other components (additives) such as a light stabilizer, an antioxidant, a processing and heat stabilizer, a light resistance stabilizer such as an ultraviolet absorber, silicone fine particles and a silane coupling agent, in addition to the compound represented by the general formula (1) and a binder resin.

[0140] Examples of the light stabilizer include tertiary amines, catechol derivatives, and lanthanide compounds. The color conversion composition of the present invention may contain two or more of these as the light stabilizer.

[0141] Examples of the antioxidant include phenolic antioxidants such as 2,6-di-tert-butyl-p-cresol and 2,6-di-tert-butyl-4-ethylphenol. The color conversion composition of the present invention may contain two or more of these antioxidants.

[0142] Examples of the processing and heat stabilizers include phosphorus stabilizers such as tributyl phosphite, tricyclohexyl phosphite, triethylphosphine, and diphenylbutylphosphine. The color conversion composition of the present invention may contain two or more of these as processing and heat stabilizers.

[0143] Examples of the light resistance stabilizer include benzotriazoles such as 2-(5-methyl-2-hydroxyphenyl)benzotriazole and 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole. The color conversion composition of the present invention may contain two or more of these as light resistance stabilizers.

[0144] In the color conversion composition 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 represented by general formula (1), and the thickness and transmittance of the color conversion sheet to be produced. The content of these additives is preferably 1.0×10 -3 Parts by weight or more and 30 parts by weight or less, more preferably 1.0×10 -2 Parts by weight or more and 15 parts by weight or less, particularly preferably 1.0×10 -1 More than 10 parts by weight and less than 10 parts by weight.

[0145] (Solvent)

[0146] The color conversion composition of the present invention may contain a solvent in addition to the compound represented by the general formula (1) and a binder resin. As the solvent, preferably, a solvent that can adjust the viscosity of the resin in a flowing state and does not excessively affect the luminescence and durability of the luminescent material is used. As such a solvent, for example, toluene, methyl ethyl ketone, methyl isobutyl ketone, hexane, acetone, terpineol, Texanol, methyl cellosolve, butyl carbitol, butyl carbitol acetate, propylene glycol monomethyl ether acetate, etc. can be cited. The color conversion composition of the present invention may contain two or more of them as solvents. Among these solvents, toluene can be preferably used from the perspective of not affecting the deterioration of the compound represented by the general formula (1) and having a small amount of residual solvent after drying.

[0147] (Method for producing color conversion composition)

[0148] An example of a method for producing a color conversion composition according to an embodiment of the present invention is described below. In this production method, a compound represented by the above-mentioned general formula (1), a binder resin, additives added as needed, a solvent, etc. are mixed in a predetermined amount. After these components are mixed in a manner to form a predetermined composition, they are mixed or kneaded uniformly using a stirring and kneading machine, thereby obtaining the color conversion composition of the present invention. As stirring and kneading machines, for example, homogenizers, rotation-revolution-type stirrers, three-roll mills, ball mills, planetary ball mills, bead mills, etc. can be cited. After mixing or dispersing, or during mixing or dispersing, it is also preferred to perform a degassing step under vacuum or reduced pressure conditions. In addition, certain specific components may be mixed in advance, or subjected to aging or other treatments. The solvent may also be removed using an evaporator to obtain a desired solid content concentration.

[0149] (Color conversion film)

[0150] The color conversion sheet according to an embodiment of the present invention (hereinafter, sometimes referred to as the color conversion sheet of the present invention) comprises a color conversion layer formed of the color conversion composition of the present invention or a cured product thereof. In the present invention, the color conversion sheet only needs to comprise the color conversion layer, and is not limited to this configuration. For example, the color conversion sheet may further comprise a substrate layer and a barrier film in addition to the color conversion layer, or may comprise two or more of these layers as required.

[0151] From the viewpoint of improving the heat resistance of the color conversion sheet, the film thickness of the color conversion sheet of the present invention is preferably 200 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. The film thickness of the color conversion sheet of the present invention refers to the film thickness (average film thickness) measured based on the method A of the thickness measurement method based on mechanical scanning in JIS K7130 (1999) Plastics-Films and Sheets-Thickness Measurement Method. By setting the film thickness (thickness) of the color conversion sheet to 50 μm or more, the toughness of the color conversion sheet can be improved. In addition, by setting the film thickness of the color conversion sheet to 200 μm or less, cracks of the color conversion sheet can be suppressed.

[0152] As representative structural examples of the color conversion sheet of the present invention, for example, the following four types can be cited. Figure 1 2 is a schematic cross-sectional view showing a first example of a color conversion sheet according to an embodiment of the present invention. Figure 1 As shown, the color conversion sheet 1A of the first example is a single-layer sheet composed of a color conversion layer 11. The color conversion layer 11 is a layer formed of a cured product of the above-mentioned color conversion composition.

[0153] Figure 2 2 is a schematic cross-sectional view showing a second example of a color conversion sheet according to an embodiment of the present invention. Figure 2 As shown in FIG. 1 , the color conversion sheet 1B of the second example is a laminate of a base layer 10 and a color conversion layer 11. In the structural example of the color conversion sheet 1B, the color conversion layer 11 is laminated on the base layer 10.

[0154] Figure 3 2 is a schematic cross-sectional view showing a third example of a color conversion sheet according to an embodiment of the present invention. Figure 3 As shown, the color conversion sheet 1C of the third example is a laminate of multiple base material layers 10 and color conversion layers 11. In the structural example of the color conversion sheet 1C, the color conversion layer 11 is sandwiched between the multiple base material layers 10.

[0155] Figure 4 2 is a schematic cross-sectional view showing a fourth example of a color conversion sheet according to an embodiment of the present invention. Figure 4 As shown in FIG. 1 , the color conversion sheet 1D of the fourth example is a laminate of multiple base material layers 10, a color conversion layer 11, and multiple barrier films 12. In the structural example of the color conversion sheet 1D, the color conversion layer 11 is sandwiched by multiple barrier films 12, and further, the laminate of the color conversion layer 11 and the multiple barrier films 12 is sandwiched by multiple base material layers 10. That is, in order to prevent the color conversion layer 11 from being deteriorated by oxygen, moisture, and heat, the color conversion sheet 1D may be as follows: Figure 4 A barrier film 12 is shown.

[0156] (Base material layer)

[0157] As a constituent substrate layer (for example Figures 2 to 4 The material of the substrate layer 10 shown in the figure may be glass, resin film, etc. As the resin film, for example, a film of plastic such as polyethylene terephthalate (PET), polyphenylene sulfide, polycarbonate, polypropylene, polyimide, etc. is preferred. As for the substrate layer, from the aspect of the ease of film peeling, the surface may be subjected to a demolding treatment in advance.

[0158] The lower limit of the thickness of the substrate layer is preferably 25 μm or more, and more preferably 38 μm or more. The upper limit of the thickness of the substrate layer is preferably 5000 μm or less, and more preferably 3000 μm or less.

[0159] (Color conversion layer)

[0160] Color conversion layers (such as Figures 1 to 4 The color conversion layer 11) shown is a layer formed by the aforementioned color conversion composition or its cured product. When the color conversion sheet of the present invention has multiple color conversion layers, these multiple color conversion layers can be formed by directly stacking each other, or by stacking each color conversion layer through an adhesive layer. The thickness of the color conversion layer is preferably 30 to 100 μm.

[0161] (Barrier Film)

[0162] As a barrier film (e.g. Figure 4 The barrier film 12 shown in the figure is preferably a barrier film that inhibits the intrusion of oxygen, moisture, heat, etc. into the color conversion layer. The color conversion sheet of the present invention may have two or more layers of such barrier films. In addition, the color conversion sheet of the present invention may be as follows Figure 4 Although the barrier films are provided on both sides of the color conversion layer as shown in the example, the barrier film may be provided on only one side of the color conversion layer.

[0163] In addition, the color conversion sheet of the present invention may also have an auxiliary layer with anti-reflection function, anti-glare function, anti-reflection and anti-glare function, hard coating function (friction resistance function), anti-static function, anti-fouling function, electromagnetic wave shielding function, infrared interception function, ultraviolet interception function, polarization function, and color adjustment function according to the required function.

[0164] (Method for manufacturing color conversion sheet)

[0165] Next, an example of a method for manufacturing a color conversion sheet according to an embodiment of the present invention is described. In the method for manufacturing the color conversion sheet, the color conversion composition prepared by the above method is applied to a substrate such as a base material layer or a barrier film and dried. Thus, a color conversion layer is formed. In the case where the binder resin contained in the color conversion composition is a thermosetting resin, the color conversion composition can be applied to the substrate and then heat-cured to form a color conversion layer. In the case where the binder resin contained in the color conversion composition is a photocurable resin, the color conversion composition can be applied to the substrate and then photocured to form a color conversion layer.

[0166] The color conversion composition can be applied by reverse roll coater, knife coater, slot die coater, direct gravure coater, indirect gravure coater, kiss coater, natural roll coater, air knife coater, roll blade coater, reverse roll blade coater, twin-flow coater, rod coater, wire bar coater, coater, dip coater, curtain coater, spin coater, knife coater, etc. Among these, in order to obtain uniform film thickness of the color conversion layer, it is preferable to apply by slot die coater.

[0167] The color conversion layer 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° C. to 200° C., and the heating time is preferably 2 minutes to 4 hours. Alternatively, the color conversion layer may be cured by heat in stages by a method such as step curing.

[0168] When the color conversion layer is formed by heat curing, a heating device may be a hot air oven or the like. The heating conditions may be selected according to the binder resin in the color conversion composition. For example, the heating temperature is preferably 100° C. to 300° C., and the heating time is preferably 1 minute to 2 hours.

[0169] When the color conversion layer is formed by photocuring, it is preferred that the color conversion layer be irradiated with high energy light such as ultraviolet rays. The light irradiation conditions can be selected according to the binder resin in the color conversion composition. For example, the wavelength of the irradiated light is preferably 200 nm to 500 nm, and the irradiation amount of the light is preferably 10 mJ / cm 2 ~10J / cm 2 .

[0170] After the color conversion layer is formed, the base material layer may be changed as needed. In this case, simple methods include, for example, a method of laminating using a hot plate, a method of using a vacuum laminator, or a dry film laminator.

[0171] In addition, as a method for evaluating the fluorescence quantum yield of the color conversion sheet, for example, the following method can be cited: the produced color conversion sheet is cut into 8 mm squares, and an absolute fluorescence quantum yield measuring device is used to irradiate the color conversion sheet with excitation light to excite the luminescent material in the color conversion layer of the color conversion sheet, thereby measuring it.

[0172] (Color conversion substrate)

[0173] The color conversion substrate according to the embodiment of the present invention (hereinafter, sometimes referred to as the color conversion substrate of the present invention) is a substrate having a plurality of color conversion layers on a transparent substrate. In the color conversion substrate, each of the plurality of color conversion layers is a layer formed of the color conversion composition of the present invention or a cured product thereof. That is, each of the plurality of color conversion layers is a color conversion layer containing at least the pyrromethene boron complex of the present invention.

[0174] In the color conversion substrate of the present invention, the plurality of color conversion layers preferably include a red conversion layer and a green conversion layer. The red conversion layer is formed of a fluorescent material that absorbs at least blue light and emits red light. The green conversion layer is formed of a fluorescent material that absorbs at least blue light and emits green light. In addition, a partition wall may be formed in the color conversion substrate of the present invention. It is preferred that each of these plurality of color conversion layers is arranged between the partition walls (recessed portion).

[0175] The color conversion substrate of the present invention can be used by causing excitation light to enter from the transparent substrate side and visually recognizing the light emission from the side opposite to the transparent substrate, or by causing excitation light to enter from the color conversion layer side and visually recognizing the light emission from the transparent substrate side.

[0176] When the color conversion substrate is irradiated with blue light having a peak wavelength of 440 nm to 460 nm, the quantum yield of the color conversion layer is usually 0.5 or more, preferably 0.7 or more, more preferably 0.8 or more, and particularly preferably 0.9 or more.

[0177] (Excitation light)

[0178] As for the type of excitation light, any excitation light can be used as long as it shows luminescence in the wavelength region that the luminescent material such as the pyrromethene boron complex of the present invention can absorb. For example, the excitation light of any light source such as a fluorescent light source such as a hot cathode tube, a cold cathode tube, an inorganic electroluminescence (EL), an organic EL element light source, an LED light source, an incandescent light source, or sunlight can also be used in principle. In particular, the light from the LED light source is a suitable excitation light. In display devices and lighting devices, from the viewpoint of improving the color purity of blue light, the light from a blue LED light source having an excitation light in a wavelength range of more than 430nm and less than 500nm is a more suitable excitation light.

[0179] The excitation light may have one luminescence peak or two or more luminescence peaks. In order to improve the color purity, it is preferred to have one luminescence peak. In addition, a plurality of excitation light sources having different luminescence peaks may be used in any combination.

[0180] (Light source unit)

[0181] The light source unit according to the embodiment of the present invention (hereinafter, sometimes referred to as the light source unit of the present invention) is configured to include at least a light source and the color conversion sheet or color conversion substrate of the present invention. The light source is, for example, a source of the excitation light. There is no particular limitation on the configuration method of these light sources and the color conversion sheet or color conversion substrate. The light source and the color conversion sheet or color conversion substrate may be closely attached to each other, or may be a remote phosphor that separates the light source from the color conversion sheet or color conversion substrate. In addition, for the purpose of improving color purity, the light source unit of the present invention may be configured to include a color filter.

[0182] As mentioned above, the excitation light in the wavelength range of 430 nm to 500 nm has a small excitation energy, which can prevent the decomposition of the luminescent material such as the pyrromethene boron complex of the present invention. Therefore, the light source used in the light source unit of the present invention is preferably a light emitting diode having a maximum luminescence in the wavelength range of 430 nm to 500 nm. Furthermore, the light source preferably has a maximum luminescence in the wavelength range of 440 nm to 470 nm.

[0183] (Display device, lighting device)

[0184] A display device according to an embodiment of the present invention includes the color conversion sheet or color conversion substrate of the present invention. For example, in a display device such as a liquid crystal display, a light source unit including the light source, the color conversion sheet, and the color conversion substrate is used as a backlight unit. In addition, a lighting device according to an embodiment of the present invention includes the color conversion sheet or color conversion substrate of the present invention. For example, the lighting device is configured in such a way that a blue LED light source as a light source unit is combined with a color conversion sheet or color conversion substrate that converts blue light from the blue LED light source into light with a longer wavelength than the blue LED light source, thereby emitting white light.

[0185] Example

[0186] The present invention will be described below with reference to Examples, but the present invention is not limited to the following Examples. In the following Examples and Comparative Examples, Compounds R-1 to R-13 and Compounds R-101 to R-104 are the compounds shown below.

[0187] [Chemical formula 14]

[0188]

[0189] [Chemical formula 15]

[0190]

[0191] [Chemical formula 16]

[0192]

[0193] In addition, the measuring methods and evaluation methods in Examples and Comparative Examples are as follows.

[0194] ( 1 H-NMR measurement)

[0195] Compound 1 H-NMR was measured in a deuterated chloroform solution using superconducting FTNMR EX-270 (manufactured by JEOL Ltd.).

[0196] (Determination of UV-Visible Absorption Spectra of Compounds)

[0197] The ultraviolet-visible absorption spectra of the compounds were measured using a U-3010 UV spectrophotometer (manufactured by Hitachi, Ltd.). -6 mol / L concentration was dissolved in toluene, and the UV-visible absorption spectrum at a wavelength of 300nm to 800nm ​​was measured to obtain the peak wavelength of the UV-visible absorption spectrum (hereinafter, sometimes referred to as the absorption peak wavelength). The results of the absorption peak wavelength are shown in Table 1 described later. In addition, the obtained absorption peak wavelength is used as one of the indicators for evaluating the half-value width and color purity of the luminescence spectrum of the compound.

[0198] (Measurement of Fluorescence Spectra of Compounds)

[0199] The fluorescence spectra of the compounds were measured using a Fluoromax-4P fluorescence phosphorescence spectrophotometer (manufactured by Horiba, Ltd.). -6 The compound was dissolved in toluene at a concentration of 100 mol / L, and the fluorescence spectrum was measured at a wavelength of 540 nm to obtain the peak wavelength of the fluorescence spectrum (hereinafter, sometimes referred to as the luminescence peak wavelength). The results of the luminescence peak wavelength are shown in Table 1. In addition, the obtained luminescence peak wavelength is used as one of the indicators for evaluating the half-value width and color purity of the luminescence spectrum of the compound.

[0200] (Calculation of Stokes shift of a compound)

[0201] The Stokes shift of the compound was calculated from the difference between the peak wavelengths of the ultraviolet-visible absorption spectrum and the fluorescence spectrum obtained for the compound as described above, that is, the difference between the absorption peak wavelength and the emission peak wavelength.

[0202] (Measurement of Fluorescence Quantum Yield of Color Conversion Sheet Using Color Conversion Composition)

[0203] For the measurement of fluorescence quantum yield, in each example and each comparative example, the color conversion sheet produced using the color conversion composition was cut into 8 mm squares to produce a sample of the color conversion sheet. The sample was excited with excitation light of a wavelength of 540 nm using an absolute fluorescence quantum yield measuring device Quantaurus-QY manufactured by Hamamatsu Photonics, and the fluorescence quantum yield at that time was measured.

[0204] (Synthesis example 1)

[0205] In Synthesis Example 1, the synthesis method of compound R-1 is described. In this synthesis method, a mixed solution of 2-phenyl-4-(o-tolyl) pyrrole (2.00 g), 2-methoxybenzoyl chloride (1.05 g), and o-xylene (30 mL) was heated under reflux and stirred for 6 hours under a nitrogen stream. Then, after the mixed solution was cooled to room temperature, methanol was added, the precipitated solid was filtered, and vacuum dried. Thus, 2-(2-methoxybenzoyl)-3-(o-tolyl)-5-phenylpyrrole (2.48 g) was obtained.

[0206] Next, a mixed solution of 2-(2-methoxybenzoyl)-3-(o-tolyl)-5-phenylpyrrole (2.48 g), spirofluorene indenopyrrole (0.96 g), methanesulfonic anhydride (1.10 g), and degassed toluene (32 mL) obtained above was heated at 125° C. for 7 hours under a nitrogen stream. After the mixed solution was cooled to room temperature, water (32 mL) was injected, and the organic layer was extracted with toluene (32 mL). The obtained organic layer was washed twice with water (20 mL), and magnesium sulfate was added to the washed organic layer, and filtered. The solvent was removed from the obtained filtrate using an evaporator to obtain a pyrromethene body as a residue. Next, diisopropylethylamine (1.62 mL) and boron trifluoride diethyl ether complex (2.39 mL) were added to the obtained mixed solution of pyrromethene body and toluene (32 mL) under a nitrogen stream, and stirred at 80° C. for 1 hour. Next, water (32 mL) was injected into the stirred mixed solution, and the organic layer was extracted with dichloromethane (32 mL). The obtained organic layer was washed twice with water (20 mL), dried with magnesium sulfate, and then the solvent was removed from the organic layer using an evaporator. The residue at this time was purified by silica gel column chromatography and vacuum dried to obtain a reddish purple powder (1.48 g).

[0207] The obtained red-purple powder 1 The results of H-NMR analysis are shown below, and it was confirmed that the reddish purple powder obtained above was compound R-1. It should be noted that spirofluorenyl indenopyrrole was synthesized according to a known method described in Org. Lett., Vol. 12, pp. 296 (2010) and the like.

[0208] Compound R-1: 1 H-NMR (CDCl3 (d=ppm)) δ1.97 (s, 3H), 3.39 (s, 3H), 5.96 (s, 1H), 6.13 (d, 1H), 6.20 (d, 1H), 6.50-6.58 (m, 3H), 6.63 (t, 1H), 6. 70 (d, 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), 7.75 (t, 2H), 8.06 (t, 2H), 8.30 (d, 1H)

[0209] [Chemical formula 17]

[0210]

[0211] Compounds other than the above compounds can be easily synthesized by changing various raw materials such as pyrrole and benzoyl chloride.

[0212] (Example 1)

[0213] In Example 1, polymethyl methacrylate resin "BR-88" (manufactured by Mitsubishi Chemical Corporation) was used as a binder resin, and 1.1 parts by weight of compound R-1 as a light-emitting material and 200 parts by weight of ethyl acetate as a solvent were mixed with 100 parts by weight of the polymethyl methacrylate resin. Then, the mixture was stirred and degassed at 1000 rpm for 20 minutes using a planetary stirring and degassing device "MAZERUSTAR KK-400" (manufactured by KURABO Corporation). Thus, a color conversion composition (red color conversion composition) as a resin liquid for sheet production was obtained.

[0214] Next, the red color conversion composition obtained above was applied to a polyester film "Lumirror" (registered trademark) U48 (manufactured by Toray Industries, Ltd., thickness 50 μm) using a slot die coater, and heated and dried at 140°C for 20 minutes. Thus, a red color conversion sheet with an average film thickness of 18 μm was formed. The fluorescence quantum yield of the red color conversion sheet was measured and found to be 90%. The evaluation results of Example 1 are summarized in Table 1 together with the measurement results of the spectrum of Compound R-1.

[0215] (Examples 2 to 13 and Comparative Examples 1 to 4)

[0216] In each of Examples 2 to 13 and Comparative Examples 1 to 4, color conversion sheets were prepared and evaluated in the same manner as in Example 1, except that the compounds listed in Table 1 were used as the luminescent materials. The evaluation results of Examples 2 to 13 and Comparative Examples 1 to 4 are summarized in Table 1 together with the measurement results of the spectra of the compounds.

[0217] [Table 1]

[0218]

[0219] Comparing Examples 1 to 13 with Comparative Example 1, it can be seen that by introducing a fused ring structure into the pyrromethene skeleton, the half-value width becomes smaller, and light emission with high color purity is obtained. In addition, by comparing Examples 1 to 13 with Comparative Example 2, it can be seen that by making the fused ring structure on the pyrromethene skeleton a single-sided fused ring, the Stokes shift becomes larger than that of a double-sided fused ring. In addition, by comparing Examples 1 to 13 with Comparative Examples 3 and 4, it can be seen that by making R in the pyrromethene boron complex as the luminescent material 1 and R 3 The aromatic groups are different from each other, and the fluorescence quantum yield of the color conversion sheet is improved.

[0220] In addition, when comparing Examples 1 to 13, in the above R 1 and R 3In the case of different phenyl groups, the fluorescence quantum yield is higher. 1 In the case of a phenyl group having a substituent at the ortho position, the fluorescence quantum yield is higher. 1 In the case of a phenyl group having a substituent at the ortho position, when the substituent is an electron withdrawing group, the Stokes shift is larger.

[0221] Industrial Applicability

[0222] As described above, the pyrromethene boron complex, color conversion composition, color conversion sheet, color conversion substrate, light source unit, display device, and lighting device according to the present invention are suitable for achieving both high color purity and high fluorescence quantum yield.

[0223] Description of Reference Numerals

[0224] 1A, 1B, 1C, 1D color conversion film

[0225] 10. Base material layer

[0226] 11 Color conversion layers

[0227] 12 Barrier film

Claims

1. A pyrromethene boron complex, characterized in that is a compound represented by the following general formula (1), [Chemical formula 1] In the general formula (1), X is CR 7 or N; R 1 and R 3 are different aromatic groups; R 2 and R 4 ~R 9 may be the same or different, and are selected from the group consisting of 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 group, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxane group, a boron group, and a phosphine oxide group; wherein R 4 With R 5 The group and R 5 With R 6 One of the two groups is a ring structure represented by any one of the following general formulae (2A) to (2D); [Chemical formula 2] In the general formulas (2A) to (2D), R 101 , R 102 and R 201 ~R 204 and R in the general formula (1) 2 and R 4 ~R 9 Ar is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocyclic ring; In addition, R 101 With R 102 A ring can be formed; * indicates a connection portion with the pyrromethene skeleton.

2. The pyrromethene boron complex according to claim 1, characterized in that The compound represented by the general formula (1) is a compound represented by any one of the following general formulas (3A) to (3D), [Chemical formula 3] In the general formulas (3A) to (3D), R 101 and R 102 and R in the general formula (1) 2 and R 4 ~R 9 Ar is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocyclic ring; In addition, R 101 With R 102 A ring can be formed.

3. The pyrromethene boron complex according to claim 1, characterized in that The Ar is a substituted or unsubstituted benzene ring.

4. The pyrromethene boron complex according to claim 1, characterized in that In the general formula (1), R 1 and R 3 are different substituted or unsubstituted phenyl groups.

5. The pyrromethene boron complex according to claim 1, characterized in that In the general formula (1), R 1 It is a phenyl group having a substituent at the ortho position.

6. The pyrromethene boron complex according to claim 1, characterized in that In the general formulas (1), (2A) to (2D), R 1 ~R 3 , R 101 , R 102 , R 201 ~R 204 At least one of R and Ar is a group including an electron withdrawing group.

7. The pyrromethene boron complex according to claim 1, characterized in that In the general formula (1), R 1 ~R 3 At least one of the groups is a group comprising an electron withdrawing group.

8. The pyrromethene boron complex according to claim 6, characterized in that The electron withdrawing group is fluorine, a fluorine-containing aromatic group, a fluorine-containing heteroaromatic 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.

9. The pyrromethene boron complex according to claim 1, characterized in that In the general formula (1), X is CR 7 , R 7 is a group represented by the following general formula (4), [Chemical formula 4] In the general formula (4), r is selected from the group consisting of 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 group, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxane group, a boron group, and a phosphine oxide group; k is an integer from 1 to 3; when k is 2 or more, r may be the same or different.

10. The pyrromethene boron complex according to claim 1, characterized in that The compound represented by the general formula (1) emits light having a peak wavelength observed in the range of 580 nm to 750 nm by using excitation light.

11. A color conversion composition, characterized in that A color conversion composition that converts incident light into light with a longer wavelength than the incident light, comprising: The pyrromethene boron complex according to claim 1; and Binder resin.

12. A color conversion sheet, characterized in that: A color conversion layer is provided which is formed of the color conversion composition according to claim 11 or a cured product thereof.

13. A color conversion substrate, characterized in that It is a color conversion substrate with multiple color conversion layers on a transparent substrate. The plurality of color conversion layers are layers formed of the color conversion composition according to claim 11 or a cured product thereof.

14. A light source unit, characterized in that have: light source; and The color conversion sheet according to claim 12 or the color conversion substrate according to claim 13.

15. The light source unit according to claim 14, wherein: The light source is a light emitting diode having a maximum light emission within a wavelength range of 430 nm to 500 nm.

16. A display device, characterized in that A color conversion sheet according to claim 12 or a color conversion substrate according to claim 13 is provided.

17. A lighting device, characterized in that A color conversion sheet according to claim 12 or a color conversion substrate according to claim 13 is provided.

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