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

Abstract

A pyrromethene boron complex according to one embodiment of the present invention is a compound that is represented by general formula (1). (In general formula (1), X represents C-R7 or N; R1 and R3 represent aryl groups that are different from each other; R2 and R4 to R9 may be the same as or different from each other, 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 arylthioether group, an aryl group, a heteroaryl group, a halogen, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, and a phosphine oxide group; and meanwhile, one of the pair of R4 and R5 and the pair of R5 and R6 is a ring structure that is expressed by one of general formulae (2A) to (2D).) (In general formulae (2A) to (2D), R101, R102 and R201 to R204 are synonymous with R2 and R4 to R9 in general formula (1); Ar represents a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring; R101 and R102 may form a ring with each other; and * denotes a linking site with a pyrromethene skeleton.)

Description

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

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

[0002] There has been active research into applying color conversion technology to LCDs, organic EL displays, lighting devices, and other devices. Color conversion refers to converting light emitted from a light emitter into light with a longer wavelength. For example, blue light can be converted into green or red light.

[0003] By forming this composition having color conversion function (hereinafter referred to as color conversion composition) 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. A white light source combining such a blue light source with a sheet having color conversion function (hereinafter referred to as color conversion sheet) is used as a light source unit such as a backlight unit, and by combining this light source unit with a liquid crystal driving part and a color filter, it becomes possible to produce a full-color display. Furthermore, a white light source combining a blue light source with a color conversion sheet can also be used directly as a white light source for LED lighting, etc.

[0004] One of the challenges facing display devices such as liquid crystal displays that utilize a color conversion system is improving color reproducibility. To improve color reproducibility, it is effective to narrow the half-widths of the blue, green, and red emission spectra of the light source unit and increase the color purity of each of the blue, green, and red colors. To solve this problem, for example, a technique has been proposed in which a pyrromethene compound is used as a component of a color-converting composition (see, for example, Patent Documents 1 and 2). Furthermore, a compound in which a fused ring structure is introduced into a pyrromethene skeleton is known as a technique for further increasing color purity (see, for example, Patent Document 3).

[0005] JP 2010-61824 A JP 2014-136771 A International Publication No. 2020 / 045242

[0006] However, it has been found that the techniques described in Patent Documents 1 to 3 have a problem in that the fluorescence quantum yield is insufficient.

[0007] The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a pyrromethene boron complex that has excellent color purity and a high fluorescence quantum yield. A second object of the present invention is to provide a color-converting composition, a color-converting sheet, a color-converting substrate, a light source unit, a display device, and a lighting device that use the pyrromethene boron complex.

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

[17] below.

[0009] That is, the pyrromethene boron complex according to the present invention is characterized in that it is a compound represented by the following general formula (1):

[0010] (In the general formula (1), X is C—R 7 Or N. 1 and R 3 are different aryl 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 atom, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, and a phosphine oxide group. 4 and R 5 and R 5 and R 6 One of the two pairs of and is a ring structure represented by any one of the following general formulas (2A) to (2D):

[0011] (In general formulas (2A) to (2D), R 101 , R 102 and R201 ~R 204 represents 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 heterocycle. 101 and R 102 may form a ring. * indicates the linkage with the pyrromethene skeleton.

[0012] The pyrromethene boron complex according to the present invention is characterized in that, in the invention described in [1] above, the compound represented by general formula (1) is a compound represented by any one of general formulas (3A) to (3D) below:

[0013] (In general formulas (3A) to (3D), R 101 and R 102 represents 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 heterocycle. 101 and R 102 may form a ring.)

[0014] The pyrromethene boron complex according to the present invention is [3] the invention described in the above [1] or [2], characterized in that Ar is a substituted or unsubstituted benzene ring.

[0015] The pyrromethene boron complex according to the present invention is, in the invention described in any one of the above items [1] to [3], [4] wherein R in the general formula (1) 1 and R 3 are different substituted or unsubstituted phenyl groups.

[0016] The pyrromethene boron complex according to the present invention is, in the invention described in any one of the above items [1] to [4], wherein R in the general formula (1) 1 is a phenyl group having a substituent at the ortho position.

[0017] The pyrromethene boron complex according to the present invention is, in the invention described in any one of the above items [1] to [5], [6] wherein R in the general formulas (1), (2A) to (2D) is 1 ~R 3 , R 101 , R 102 , R 201 ~R 204 and at least one of Ar is a group containing an electron-withdrawing group.

[0018] The pyrromethene boron complex according to the present invention is, in the invention described in any one of the above items [1] to [6], wherein R in the general formula (1) 1 ~R 3 At least one of the groups is a group containing an electron-withdrawing group.

[0019] The pyrromethene boron complex according to the present invention is [8] the invention according to any one of the above [1] to [7], characterized in that the electron-withdrawing group is fluorine, 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.

[0020] The pyrromethene boron complex according to the present invention is, [9] the invention described in any one of the above [1] to [8], wherein X in the general formula (1) is C—R 7 and R 7 is a group represented by the following general formula (4):

[0021] (In 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 atom, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, and a phosphine oxide group. k is an integer of 1 to 3. When k is 2 or more, each r may be the same or different.)

[0022] The pyrromethene boron complex according to the present invention is characterized in that, in the invention described in any one of the above items [1] to [9], the compound represented by the general formula (1) emits light with a peak wavelength observed in the range of 580 nm to 750 nm when excited with light.

[0023]

[0023] The color-converting composition according to the present invention is

[11] a color-converting composition that converts incident light into light having a longer wavelength than the incident light, and is characterized by comprising the pyrromethene boron complex according to any one of [1] to

[10] above and a binder resin.

[0024]

[12] The color conversion sheet according to the present invention is characterized by comprising a color conversion layer made of the color conversion composition according to

[11] above or a cured product thereof.

[0025] Furthermore, the color conversion substrate according to the present invention is

[13] a color conversion substrate comprising a plurality of color conversion layers on a transparent substrate, wherein the plurality of color conversion layers are layers made of the color conversion composition described in

[11] above or a cured product thereof.

[0026] The light source unit according to the present invention is characterized by comprising:

[14] a light source; and the color conversion sheet according to

[12] above or the color conversion substrate according to

[13] above.

[0027] Furthermore, the light source unit according to the present invention is characterized in that, in the invention described in

[14] above, the light source is a light-emitting diode having a maximum light emission in the wavelength range of 430 nm or more and 500 nm or less.

[0028]

[16] A display device according to the present invention is characterized by comprising the color conversion sheet according to the above

[12] or the color conversion substrate according to the above

[13] .

[0029]

[17] A lighting device according to the present invention is characterized by comprising the color conversion sheet according to the above

[12] or the color conversion substrate according to the above

[13] .

[0030] The present invention provides a pyrromethene boron complex that is excellent in color purity and can achieve a high fluorescence quantum yield. This pyrromethene boron complex can provide a color-converting composition, a color-converting sheet, and a color-converting substrate that can achieve a high fluorescence quantum yield and emission of high color purity (e.g., red emission), thereby improving the color reproducibility of light source units, display devices such as liquid crystal displays, and lighting devices.

[0031] Fig. 1 is a schematic cross-sectional view showing a first example of a color conversion sheet according to an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view showing a second example of a color conversion sheet according to an embodiment of the present invention. Fig. 3 is a schematic cross-sectional view showing a third example of a color conversion sheet according to an embodiment of the present invention. Fig. 4 is a schematic cross-sectional view showing a fourth example of a color conversion sheet according to an embodiment of the present invention.

[0032] Preferred embodiments of the pyrromethene boron complex according to the present invention, and the color-converting composition, color-converting sheet, color-converting substrate, light source unit, display device, and lighting device using the same will be specifically described below. However, the present invention is not limited to the following embodiments, and can be practiced with various modifications depending on the purpose and application.

[0033] (Pyrromethene boron complex) The pyrromethene boron complex according to an embodiment of the present invention (hereinafter sometimes abbreviated 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):

[0034]

[0035] In the general formula (1), X is C—R 7 Or N. 1 and R 3 are different aryl 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 atom, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, and a phosphine oxide group. 4 and R 5 and R 5 and R 6 One of the two pairs of groups is a ring structure represented by any one of the following general formulae (2A) to (2D).

[0036]

[0037] In general formulas (2A) to (2D), R 101 , R 102 and R 201 ~R 204 represents R in general formula (1). 2 and R 4 ~R 9 Ar is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocycle. 101 and R 102 may form a ring. The symbol "*" in the general formulae (2A) to (2D) indicates a linking portion to the pyrromethene skeleton.

[0038] In all of the above groups, hydrogen may be deuterium. This also applies to the compounds or partial structures thereof described below. In the following description, for example, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms refers to an aryl group having a total carbon number of 6 to 40, including the carbon atoms contained in the substituents substituted on the aryl group. The same applies to other substituents that specify the number of carbon atoms.

[0039] In addition, in all of the above groups, the substituent when substituted is 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 carboxy group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, or a phosphine oxide group, and more preferably a specific substituent that is preferred in the description of each substituent.In addition, these substituents may be further substituted with the above-mentioned substituent.

[0040] 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.

[0041] Of all the groups mentioned above, the alkyl group refers to a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group, which may or may not have a substituent. When substituted, the additional substituent is not particularly limited, and examples thereof include an alkyl group, a halogen, an aryl group, and a heteroaryl group, and this point is also common to the following description. Furthermore, 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 ease of availability and cost.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] The aryl ether group refers to a functional group to which an aromatic hydrocarbon group, such as a phenoxy 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.

[0050] 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.

[0051] The aryl group refers to an aromatic hydrocarbon group such as a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthryl group, an anthracenyl group, a benzophenanthryl group, a benzanthracenyl group, a chrysenyl group, a pyrenyl group, a fluoranthenyl group, a triphenylenyl group, a benzofluoranthenyl group, a dibenzoanthracenyl group, a perylenyl group, or a helicenyl group. Among these, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, an anthracenyl group, a pyrenyl group, a fluoranthenyl group, or a triphenylenyl group is preferred. The aryl group may or may not have a substituent. The number of carbon atoms in the aryl group is not particularly limited, but is preferably in the range of 6 to 40, more preferably 6 to 30.

[0052] R in general formula (1) 2 and R 4 ~R 9When is a substituted or unsubstituted 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, even more preferably a phenyl group, a biphenyl group, or a terphenyl group, and particularly preferably a phenyl group.

[0053] 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.

[0054] Examples of heteroaryl groups include pyridyl, furanyl, thienyl, quinolinyl, isoquinolinyl, pyrazinyl, pyrimidyl, pyridazinyl, triazinyl, naphthyridinyl, cinnolinyl, phthalazinyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothienyl, indolyl, dibenzofuranyl, dibenzothienyl, carbazolyl, and benzocarbazolyl. It refers to a cyclic aromatic group having one or more atoms other than carbon in the ring, such as a benzoyl group, 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.

[0055] R in general formula (1) 2 and R 4 ~R9 is a substituted or unsubstituted 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.

[0056] 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.

[0057] The term "halogen" refers to an atom selected from fluorine, chlorine, bromine, and iodine. The carbonyl group, carboxy group, oxycarbonyl group, and carbamoyl 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.

[0058] The amino group is a substituted or unsubstituted amino group. The amino group may or may not have a substituent, and in the case of a substitution, examples of the substituent include an aryl group, a heteroaryl group, a linear alkyl group, and a branched alkyl group. Preferred aryl groups and heteroaryl groups are a phenyl group, a naphthyl group, a pyridyl group, and a quinolinyl group. These substituents may be further substituted. The number of carbon atoms is not particularly limited, but is preferably in the range of 2 to 50, more preferably 6 to 40, and particularly preferably 6 to 30.

[0059] The silyl group refers to, for example, alkylsilyl groups such as trimethylsilyl group, triethylsilyl group, tert-butyldimethylsilyl group, propyldimethylsilyl group, and vinyldimethylsilyl group, and arylsilyl groups such as phenyldimethylsilyl group, tert-butyldiphenylsilyl group, triphenylsilyl group, and trinaphthylsilyl group. 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.

[0060] The siloxanyl group refers to a silicon compound group via an ether bond, such as a trimethylsiloxanyl group. The substituent on the silicon may be further substituted. The boryl group refers to a substituted or unsubstituted boryl group. The boryl group may or may not have a substituent, and in the case of substitution, 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, among which an aryl group and an aryl ether group are preferred. The phosphine oxide group refers to a -P(=O)R 10 R 11 The R of the phosphine oxide group is a group represented by the formula: 10 and R 11 represents R in general formula (1). 2 and R 4 ~R 9 is selected from the same group as

[0061] The compound represented by 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 general formula (1) having a pyrromethene boron complex skeleton exhibits a high fluorescence quantum yield. Furthermore, the compound represented by general formula (1) has a small peak half-width of its emission spectrum, so that efficient emission, i.e., improved fluorescence quantum yield and high color purity, can be achieved.

[0062] 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.

[0063] The pyrromethene boron complex of the present invention is a compound represented by general formula (1), which has a pyrromethene boron complex skeleton containing a ring structure represented by any one of the general formulae (2A) to (2D). Each ring structure represented by each of general formulae (2A) to (2D) has a double bond, and the double bond is always chemically bonded to the pyrromethene boron complex skeleton via a carbon atom. This suppresses 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 excellent 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 and improve color reproducibility.

[0064] In the pyrromethene boron complex of the present invention, R 1 and R 3 are different aryl groups. 1 and R 3 are different aryl groups, the dispersibility of the pyrromethene boron complex is improved, and concentration quenching can be suppressed, thereby improving the fluorescence quantum yield.

[0065] In the present invention, the different aryl groups include, for example, aryl groups having different carbon skeletons, such as a phenyl group and a naphthyl group, and aryl groups having the same carbon skeleton but different substituents or different types, such as a phenyl group and a toluyl group, or a t-butylphenyl group and a methoxyphenyl group. Aryl groups having the same carbon skeleton but different substituents are more preferred, as this further improves the dispersibility of the pyrromethene boron complex.

[0066] In addition, in the compound represented by the general formula (1), as described above, R １ and R ３ are different aryl groups, and R 4 and R 5 and R 5 and R 6 One of the two pairs, i.e., pairs of (1) and (2), is a ring structure represented by any one of general formulas (2A) to (2D). This allows for sharp emission while maintaining a certain degree of Stokes shift. This is because a moderate degree of structural relaxation occurs during the process of excitation and emission of light in the compound represented by general formula (1). The Stokes shift is the difference between the maximum absorption wavelength and the maximum fluorescence wavelength.

[0067] 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 of the specific wavelength band and the emission spectrum of the target wavelength band, re-absorption occurs, in which the emitted light is re-absorbed. 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.

[0068] In the case of a pyrromethene boron complex, if the structural relaxation is excessively suppressed, the Stokes shift becomes excessively small, and the luminous efficiency decreases. Therefore, in order to have high color purity and high brightness, it is important that the pyrromethene boron complex undergoes appropriate structural relaxation when excited to emit light. In the compound represented by general formula (1) (pyrromethene boron complex), R4 and R 5 and R 5 and R 6 and one of the two pairs is a ring structure represented by any one of general formulas (2A) to (2D), 1 and R 3 are different aryl groups. As a result, the pyrromethene boron complex undergoes appropriate structural relaxation during the emission process, resulting in a narrow half-width peak in the emission spectrum and high brightness.

[0069] Furthermore, by introducing appropriate substituents into appropriate positions of the compound represented by general formula (1), various characteristics and physical properties such as luminous efficiency, color purity, thermal stability, light stability, and dispersibility can be adjusted.

[0070] For example, the compound represented by general formula (1) is preferably a compound represented by any one of the following general formulae (3A) to (3D).

[0071]

[0072] In the general formulae (3A) to (3D), X represents C—R 7 Or N. 101 and R 102 represents 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 heterocycle. 101 and R 102 may form a ring.

[0073] In each of the compounds represented by general formula (3A), the compounds represented by general formula (3B), the compounds represented by general formula (3C), and the compounds represented by general formula (3D), conjugation is efficiently extended, and therefore light emission with high color purity at a longer wavelength is possible.

[0074] Furthermore, 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. Furthermore, when Ar is a substituted or unsubstituted benzene ring, thermal and electrical stability are improved, so it is particularly preferred.

[0075] In the pyrromethene boron complex of the present invention, R 1 and R 3 are preferably different substituted or unsubstituted phenyl groups, because this configuration allows the compound represented by general formula (1) to exhibit better thermal stability and light stability.

[0076] In the pyrromethene boron complex of the present invention, R 1 is preferably a phenyl group having a substituent at the ortho position. 1 When R is a phenyl group having a substituent at the ortho position, intramolecular rotation in the excited state is suppressed, and an emission spectrum with a narrow half-width can be obtained. 1 is a phenyl group having a substituent at the ortho position, the dispersibility of the pyrromethene boron complex is improved, and therefore the fluorescence quantum yield is improved.

[0077] In particular, in the pyrromethene boron complex of the present invention, R 1 and R 3 are different substituted or unsubstituted phenyl groups, and the R 1 is more preferably a phenyl group having a substituent at the ortho position.

[0078] In the pyrromethene boron complex of the present invention, R 1 ~R 3 , R 101 , R 102 , R 201 ~R 204At least one of R and Ar is preferably a group containing an electron-withdrawing group, because the electron-withdrawing group causes appropriate structural relaxation in the excited state of the compound represented by general formula (1), resulting in a larger Stokes shift and thus a further improvement in luminous efficiency. 1 ~R 3 It is particularly preferred that at least one of the groups contains an electron-withdrawing group, since this leads to greater structural relaxation.

[0079] Electron-withdrawing groups, also called electron-accepting groups, are groups that attract electrons from the substituted atomic group due to the inductive effect or resonance effect in organic electronics. Examples of electron-withdrawing groups include those with a positive value as the Hammett's substituent constant (σp(para)). The Hammett's substituent constant (σp(para)) can be cited from the Basic Chemistry Handbook, 5th Revised Edition (II-380 pages).

[0080] Examples of the electron-withdrawing group include -F (σp: +0.06), -Cl (σp: +0.23), -Br (σp: +0.23), -I (σp: +0.18), and -COR. 12 (σp:R 12 is an ethyl group, -CONH2 (σp: +0.45), -COR 12 (σp:R 12 is a methyl group, -CF3 (σp: +0.49), -SO2R 12 (σp:R 12 is a methyl group), -NO2 (σp: +0.69), etc. 12 each 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.

[0081] Preferred electron-withdrawing groups include fluorine, 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, and a cyano group, because they are difficult to chemically decompose.

[0082] In the pyrromethene boron complex of the present invention, X in the general formula (1) is C—R 7 and the R 7 is preferably a group represented by the following general formula (4), because it can impart bulkiness to the compound represented by general formula (1) and improve the luminous efficiency.

[0083]

[0084] In 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 atom, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, and a phosphine oxide group. k is an integer of 1 to 3. When k is 2 or more, each r may be the same or different.

[0085] In general formula (4), r is preferably a substituted or unsubstituted aryl group. Among the aryl groups, particularly preferred examples include a phenyl group and a naphthyl group. When r is an aryl group, k in general formula (4) is preferably 1 or 2, and more preferably 2. Furthermore, at least one of the r's is preferably substituted with an alkyl group or an aryl group. In this case, particularly preferred examples of the alkyl group include a methyl group, an ethyl group, and a tert-butyl group. Furthermore, when r is an aryl group, the aryl group is preferably a phenyl group or a naphthyl group. These aryl groups may be further substituted with 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 atom, a cyano group, a carboxy group, an ester group, an oxycarbonyl group, or an alkoxy group.

[0086] Furthermore, from the viewpoint of controlling the fluorescence wavelength or absorption wavelength and increasing compatibility with the solvent, r in general formula (4) is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a halogen. Among these, a methyl group, an ethyl group, a tert-butyl group, or a methoxy group is more preferable. From the viewpoint of dispersibility, a tert-butyl group or a methoxy group is particularly preferable as r. This can prevent quenching due to aggregation of molecules.

[0087] Examples of the compound represented by general formula (1) are shown below, but the pyrromethene boron complex of the present invention is not limited to these.

[0088]

[0089]

[0090]

[0091] 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 compound represented by general formula (5) below and a compound represented by general formula (6) are heated in 1,2-dichloroethane in the presence of phosphorus oxychloride, and then a compound represented by general formula (7) below 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 ~R 9 is the same as described above. J represents a halogen.

[0092]

[0093] 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.

[0094] The pyrromethene boron complex of the present invention preferably exhibits emission observed in a peak wavelength range of 580 nm to 750 nm when excited with excitation light. Hereinafter, emission observed in a peak wavelength 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.

[0095] (Color-Converting Composition) The color-converting composition according to an embodiment of the present invention (hereinafter, sometimes abbreviated as the color-converting composition of the present invention) will be described in detail. The color-converting composition of the present invention converts incident light from a light-emitting body such as a light source into light with a longer wavelength than the incident light, and preferably contains the pyrromethene boron complex of the present invention described above and a binder resin described below.

[0096] The color-changing composition of the present invention may contain other compounds as needed in addition to the pyrromethene boron complex of the present invention described above. For example, in order to further increase the efficiency of energy transfer from excitation light to the pyrromethene boron complex of the present invention, the color-changing composition of the present invention may contain an assist dopant such as rubrene. Furthermore, if it is desired to add an emission color other than the emission color of the pyrromethene boron complex of the present invention, a desired organic light-emitting material, for example, an organic light-emitting material such as a coumarin derivative or a rhodamine derivative, can be added. In addition to organic light-emitting materials, known light-emitting materials such as inorganic phosphors, fluorescent pigments, fluorescent dyes, and quantum dots can also be added in combination. Examples of organic light-emitting materials other than the pyrromethene boron complex of the present invention are shown below, but the present invention is not particularly limited thereto.

[0097]

[0098] In the present invention, the color-converting composition preferably emits light with a peak wavelength in the range of 500 nm to less than 580 nm (green light) when excited by excitation light, and preferably emits light with a peak wavelength in the range of 580 nm to 750 nm (red light) when excited by excitation light.

[0099] That is, the color-converting 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, when excited by excitation light, emits light having a peak wavelength observed in the region of 500 nm or more and less than 580 nm. The luminescent material (b) is a luminescent material that, when excited by at least one of excitation light and the emission from the luminescent material (a), emits light having a peak wavelength observed in the region of 580 nm or more and 750 nm or less. At least one of the luminescent materials (a) and (b) is preferably the pyrromethene boron complex of the present invention, and it is more preferable that the luminescent material (b) is the pyrromethene boron complex of the present invention. That is, it is more preferable that the compound represented by the above-mentioned general formula (1) emits light having a peak wavelength observed in the region of 580 nm or more and 750 nm or less when excited by excitation light. It is also more preferable that the excitation light used has a wavelength in the range of 430 nm or more and 500 nm or less.

[0100] Because a portion of excitation light in the wavelength range of 430 nm to 500 nm is partially transmitted through the color conversion sheet according to an embodiment of the present invention, when a blue LED with a sharp emission peak is used, white light having a sharply shaped emission spectrum in each of the blue, green, and red colors can be obtained. As a result, a larger color gamut with more vivid colors can be efficiently produced, particularly in display devices such as monitors. In other words, a display device with excellent color reproduction can be obtained. 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, and therefore a desirable white light source with improved color rendering can be obtained.

[0101] Known materials can be used as the luminescent material (a) and the luminescent material (b). For example, pyrromethene derivatives are particularly suitable compounds because they provide a high luminescence quantum yield and exhibit luminescence with high color purity. Among pyrromethene derivatives, the pyrromethene boron complex of the present invention is preferred because it significantly improves durability.

[0102] Furthermore, when both the luminescent material (a) and the luminescent material (b) are the pyrromethene boron complex of the present invention, it is possible to achieve both highly efficient luminescence, high color purity, and high durability, which is preferable. The color-converting composition of the present invention preferably emits luminescence with a peak wavelength observed in the range of 580 nm to 750 nm when using excitation light.

[0103] The content of the pyrromethene boron complex (compound represented by general formula (1)) contained in the color-converting composition of the present invention depends 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-converting sheet to be produced, but is usually 1.0 × 10 relative to 100 parts by mass of the binder resin. -4 The content of the pyrromethene boron complex is 1.0 × 10 to 30 parts by mass relative to 100 parts by mass of the binder resin. -3 It is more preferable that the content is 1.0×10 to 10 parts by mass. -2 Particularly preferably, the amount is from 1 part to 5 parts by weight.

[0104] (Binder Resin) The color-changing composition of the present invention preferably contains a binder resin in addition to the pyrromethene boron complex of the present invention described above. The binder resin is preferably a material that forms a continuous phase and has excellent moldability, transparency, heat resistance, and the like. Examples of such binder resins include photocurable resist materials having reactive vinyl groups, such as acrylic, methacrylic, polyvinyl cinnamate, polyimide, and cyclic rubber, epoxy resins, silicone resins (including organopolysiloxane cured products (crosslinked products) such as silicone rubber and silicone 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 the repeating unit, and copolymers thereof. The color-changing composition of the present invention may contain two or more of these as binder resins.

[0105] 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.

[0106] These resins can be obtained, for example, by copolymerizing the respective raw material monomers in the presence of a polymerization initiator, etc. Commercially available binder resins can also be used.

[0107] Among the binder resins described above, for example, the silicone resin may be either a thermosetting silicone resin or a thermoplastic silicone resin. Thermosetting silicone resins cure at room temperature or at temperatures of 50 to 200°C and have excellent transparency, heat resistance, and adhesiveness. As the thermosetting silicone resin, commercially available products, such as silicone encapsulants for general LED applications, can also be used. Specific examples include OE-6630A / B and OE-6336A / B manufactured by DuPont-Toray Specialty Materials, and SCR-1012A / B and SCR-1016A / B manufactured by Shin-Etsu Chemical Co., Ltd. As the thermoplastic silicone resin, commercially available products, such as the RSN series, including RSN-0805 and RSN-0217 manufactured by DuPont-Toray Specialty Materials, can be used.

[0108] (Other Components) The color-changing composition of the present invention may contain, in addition to the compound represented by the general formula (1) and the binder resin described above, 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.

[0109] Examples of light stabilizers include tertiary amines, catechol derivatives, lanthanoid compounds, etc. The color-changing composition of the present invention may contain two or more of these light stabilizers.

[0110] Examples of antioxidants include phenolic antioxidants such as 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-4-ethylphenol, etc. The color-changing composition of the present invention may contain two or more of these antioxidants.

[0111] Examples of processing and heat stabilizers include phosphorus-based stabilizers such as tributyl phosphite, tricyclohexyl phosphite, triethyl phosphine, diphenylbutyl phosphine, etc. The color-changing composition of the present invention may contain two or more of these processing and heat stabilizers.

[0112] Examples of light resistance stabilizers 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-changing composition of the present invention may contain two or more of these light resistance stabilizers.

[0113] In the color-converting composition of the present invention, the content of these additives can be set depending on the molar absorption coefficient, fluorescence quantum yield, and absorption intensity at the excitation wavelength of the compound represented by general formula (1), as well as the thickness and transmittance of the color-converting sheet to be produced. The content of these additives is 1.0 × 10 relative to 100 parts by weight of the binder resin. -3 It is preferable that the amount is 1.0×10 -2 It is more preferable that the amount is 1.0×10 parts by weight or more and 15 parts by weight or less. -1 It is particularly preferable that the amount is from 1 part by weight to 10 parts by weight.

[0114] (Solvent) The color-changing composition of the present invention may further contain a solvent in addition to the compound represented by general formula (1) and the binder resin described above. The solvent is preferably one that can adjust the viscosity of the resin in a fluid state and does not excessively affect the luminescence and durability of the luminescent material. Examples of such solvents include toluene, methyl ethyl ketone, methyl isobutyl ketone, hexane, acetone, terpineol, Texanol, methyl cellosolve, butyl carbitol, butyl carbitol acetate, and propylene glycol monomethyl ether acetate. The color-changing composition of the present invention may contain two or more of these solvents. Among these solvents, toluene is particularly preferred because it does not affect the deterioration of the compound represented by general formula (1) and leaves little residual solvent after drying.

[0115] (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. In this method, predetermined amounts of the compound represented by the general formula (1), a binder resin, and, if necessary, additives and solvents are mixed together. These components are mixed to a predetermined composition, and then homogeneously mixed or kneaded using a stirrer / kneader to obtain the color-converting composition of the present invention. 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.

[0116] (Color conversion sheet) A color conversion sheet according to an embodiment of the present invention (hereinafter sometimes abbreviated as the color conversion sheet of the present invention) comprises a color conversion layer made of the above-described color conversion composition of the present invention or a cured product thereof. In the present invention, the color conversion sheet is not limited in its configuration as long as it comprises the above-described color conversion layer. For example, in addition to the above-described color conversion layer, the color conversion sheet may also have a substrate layer or a barrier film as necessary, and may have two or more of these layers.

[0117] 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 Method A, a mechanical scanning thickness measurement method, in JIS K7130 (1999) Plastics - Films and Sheets - Thickness Measurement Methods. By making the film thickness (thickness) of the color conversion sheet 50 μm or more, the toughness of the color conversion sheet can be improved. Furthermore, by making the film thickness of the color conversion sheet 200 μm or less, cracking of the color conversion sheet can be suppressed.

[0118] Representative structural examples of the color conversion sheet of the present invention include the following four: Fig. 1 is a schematic cross-sectional view showing a first example of a color conversion sheet according to an embodiment of the present invention. As shown in Fig. 1, the color conversion sheet 1A of this first example is a single-layer sheet composed of a color conversion layer 11. The color conversion layer 11 is a layer made of a cured product of the color conversion composition described above.

[0119] 2 is a schematic cross-sectional view showing a second example of a color conversion sheet according to an embodiment of the present invention. As shown in FIG. 2, this second example of a color conversion sheet 1B is a laminate of a base layer 10 and a color conversion layer 11. In this structural example of color conversion sheet 1B, the color conversion layer 11 is laminated on the base layer 10.

[0120] 3 is a schematic cross-sectional view showing a third example of a color conversion sheet according to an embodiment of the present invention. As shown in FIG. 3, this third example of a color conversion sheet 1C is a laminate of multiple base material layers 10 and a color conversion layer 11. In this structural example of color conversion sheet 1C, the color conversion layer 11 is sandwiched between multiple base material layers 10.

[0121] 4 is a schematic cross-sectional view showing a fourth example of a color conversion sheet according to an embodiment of the present invention. As shown in FIG. 4, this fourth example color conversion sheet 1D is a laminate of multiple base layers 10, a color conversion layer 11, and multiple barrier films 12. In this structural example of color conversion sheet 1D, the color conversion layer 11 is sandwiched between multiple barrier films 12, and this laminate of the color conversion layer 11 and the multiple barrier films 12 is further sandwiched between multiple base layers 10. That is, color conversion sheet 1D may have a barrier film 12 as shown in FIG. 4 to prevent deterioration of the color conversion layer 11 due to oxygen, moisture, or heat.

[0122] (Substrate Layer) Examples of materials constituting the substrate layer (for example, the substrate layer 10 shown in FIGS. 2 to 4) include glass and resin films. Preferred resin films include plastic films such as polyethylene terephthalate (PET), polyphenylene sulfide, polycarbonate, polypropylene, and polyimide. To facilitate peeling of the film, the surface of the substrate layer may be subjected to a release treatment in advance.

[0123] The lower limit of the thickness of the substrate layer is preferably 25 μm or more, more preferably 38 μm or more, and the upper limit of the thickness of the substrate layer is preferably 5000 μm or less, more preferably 3000 μm or less.

[0124] (Color conversion layer) The color conversion layer (for example, color conversion layer 11 shown in Figures 1 to 4) is a layer made of the above-mentioned color conversion composition or a cured product thereof. When the color conversion sheet of the present invention has multiple color conversion layers, these multiple color conversion layers may be laminated directly on each other, or may be laminated via an adhesive layer. The thickness of the color conversion layer is preferably 30 to 100 µm.

[0125] (Barrier Film) The barrier film (for example, barrier film 12 shown in FIG. 4) is preferably one that suppresses the penetration 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. Furthermore, the color conversion sheet of the present invention may have barrier films on both sides of the color conversion layer as exemplified in FIG. 4, or may have a barrier film on only one side of the color conversion layer.

[0126] Furthermore, the color conversion sheet of the present invention may further include an auxiliary layer having 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 functions.

[0127] (Manufacturing method of color conversion sheet) Next, an example of a manufacturing method of a color conversion sheet according to an embodiment of the present invention will be described. In this manufacturing method of a color conversion sheet, the color conversion composition prepared by the above-described method is applied to a substrate such as a base layer or a barrier film, and then dried. This forms a color conversion layer. When the binder resin contained in the color conversion composition is a thermosetting resin, the color conversion composition may be applied to a substrate and then heat-cured to form a color conversion layer. When the binder resin contained in the color conversion composition is a photocurable resin, the color conversion composition may be applied to a substrate and then photocured to form a color conversion layer.

[0128] The color conversion composition can be applied using a reverse roll coater, blade coater, slit die coater, direct gravure coater, offset gravure coater, kiss coater, natural roll coater, air knife coater, roll blade coater, reverse roll blade coater, two-stream coater, rod coater, wire bar coater, applicator, dip coater, curtain coater, spin coater, knife coater, etc. Of these, application using a slit die coater is preferred in order to obtain a uniform film thickness of the color conversion layer.

[0129] 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. It is also possible to heat and cure the color conversion layer in stages using a method such as step curing.

[0130] When the color conversion layer is formed by heat curing, a hot air oven or the like can be used as a heating device. The heating conditions can be selected depending on 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.

[0131] When forming a color conversion layer by photocuring, it is preferable to irradiate the color conversion layer with high-energy light such as ultraviolet light. The light irradiation conditions can be selected depending on 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 dose of the light is preferably 10 mJ / cm. 2 ~10 J / cm 2 is preferred.

[0132] After the color conversion layer is formed, the base material layer can be changed as needed. In this case, simple methods include, for example, a method of replacing the base material layer using a hot plate, or a method using a vacuum laminator or a dry film laminator.

[0133] Furthermore, examples of methods for evaluating the fluorescence quantum yield of a color conversion sheet include a method in which the prepared color conversion sheet is cut into 8 mm squares, and an absolute fluorescence quantum yield measurement 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 the fluorescence quantum yield.

[0134] (Color conversion substrate) The color conversion substrate according to an embodiment of the present invention (hereinafter sometimes abbreviated as the color conversion substrate of the present invention) is a substrate comprising a plurality of color conversion layers on a transparent substrate. In this color conversion substrate, each of these plurality of color conversion layers is a layer made of the above-described color conversion composition of the present invention or a cured product thereof. That is, each of these plurality of color conversion layers is a color conversion layer containing at least the above-described pyrromethene boron complex of the present invention.

[0135] 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 phosphor material that absorbs at least blue light and emits red light. The green conversion layer is formed of a phosphor material that absorbs at least blue light and emits green light. The color conversion substrate of the present invention may also be formed with partition walls. Each of the plurality of color conversion layers is preferably disposed between the partition walls (in a recess).

[0136] The color conversion substrate of the present invention can be used by irradiating excitation light from the transparent substrate side and visually observing the emitted light from the side opposite the transparent substrate, or by irradiating excitation light from the color conversion layer side and visually observing the emitted light from the transparent substrate side.

[0137] 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, when blue light having a peak wavelength of 440 nm or more and 460 nm or less is irradiated onto the color conversion substrate.

[0138] (Excitation Light) Any type of excitation light can be used as long as it emits light in a wavelength range that can be absorbed by the luminescent substance of the present invention, such as the pyrromethene boron complex. In principle, excitation light from any light source can be used, such as a hot cathode tube, a cold cathode tube, a fluorescent light source such as an inorganic electroluminescence (EL), an organic EL element light source, an LED light source, an incandescent light source, or sunlight. Light from an LED light source is particularly preferred. In display devices and lighting devices, light from a blue LED light source having excitation light in a wavelength range of 430 nm to 500 nm is even more preferred, from the viewpoint of enhancing the color purity of blue light.

[0139] The excitation light may have one emission peak or two or more emission peaks, but in order to improve color purity, it is preferable to use one emission peak. It is also possible to use any combination of multiple excitation light sources with different emission peaks.

[0140] (Light Source Unit) A light source unit according to an embodiment of the present invention (hereinafter sometimes abbreviated 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 described above. The light source is, for example, a source of the excitation light described above. The arrangement of the light source and the color conversion sheet or color conversion substrate is not particularly limited, and the light source and the color conversion sheet or color conversion substrate may be closely attached to each other, or a remote phosphor type in which the light source and the color conversion sheet or color conversion substrate are separated from each other may be used. Furthermore, the light source unit of the present invention may be configured to further include a color filter for the purpose of increasing color purity.

[0141] As described above, excitation light in the wavelength range of 430 nm to 500 nm has relatively low excitation energy and can prevent decomposition of luminescent substances 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 emission wavelength in the range of 430 nm to 500 nm. Furthermore, this light source preferably has a maximum emission wavelength in the range of 440 nm to 470 nm.

[0142] (Display device, lighting device) A display device according to an embodiment of the present invention includes the color conversion sheet or color conversion substrate of the present invention described above. For example, a display device such as a liquid crystal display uses a light source unit having the above-described light source, color conversion sheet, color conversion substrate, etc. as a backlight unit. Furthermore, a lighting device according to an embodiment of the present invention includes the above-described color conversion sheet or color conversion substrate of the present invention. For example, this lighting device is configured to emit white light by combining a blue LED light source as a light source unit with a color conversion sheet or color conversion substrate that converts blue light from this blue LED light source into light with a longer wavelength.

[0143] 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.

[0144]

[0145]

[0146]

[0147] The measurement and evaluation methods used in the examples and comparative examples are as follows.

[0148] ( 1 H-NMR measurement) 1 H-NMR was measured using a superconducting FTNMR EX-270 (manufactured by JEOL Ltd.) in a deuterated chloroform solution.

[0149] (Measurement of UV-Visible Absorption Spectrum of Compound) The UV-Visible absorption spectrum of a compound was measured using a U-3010 UV spectrophotometer (manufactured by Hitachi, Ltd.) by dissolving the compound in toluene at 1×10 -6The compound was dissolved at a concentration of 1000 mol / L, and its ultraviolet-visible absorption spectrum was measured at wavelengths of 300 nm to 800 nm to determine the peak wavelength of the ultraviolet-visible absorption spectrum (hereinafter, sometimes referred to as the absorption peak wavelength). The results for the absorption peak wavelength are shown in Table 1 below. The obtained absorption peak wavelength was used as one of the indices for evaluating the half-width and color purity of the emission spectrum of the compound.

[0150] (Measurement of Fluorescence Spectrum of Compound) The fluorescence spectrum of the compound was measured using a Fluoromax-4P fluorescent phosphorescence spectrophotometer (manufactured by Horiba, Ltd.) by dissolving the compound in toluene at 1 × 10 -6 The compound was dissolved at a concentration of 1000 mol / L and excited at a wavelength of 540 nm to measure its fluorescence spectrum, and the peak wavelength of this fluorescence spectrum (hereinafter sometimes referred to as the emission peak wavelength) was determined. The emission peak wavelength results are shown in Table 1. The obtained emission peak wavelength was used as one of the indices for evaluating the half-width and color purity of the emission spectrum of the compound.

[0151] (Calculation of Stokes Shift of Compound) The Stokes shift of a compound was calculated from the difference in peak wavelength between the ultraviolet-visible absorption spectrum and the fluorescence spectrum obtained for the compound as described above, i.e., the difference between the absorption peak wavelength and the emission peak wavelength. The results of this Stokes shift are shown in Table 1.

[0152] (Measurement of Fluorescence Quantum Yield of Color Conversion Sheet Using Color Conversion Composition) In measuring the fluorescence quantum yield, in each Example and Comparative Example, the color conversion sheet prepared using the color conversion composition was cut into 8 mm squares to prepare a color conversion sheet sample. The prepared sample was excited with excitation light of a wavelength of 540 nm using an absolute fluorescence quantum yield measurement device Quantaurus-QY manufactured by Hamamatsu Photonics K.K., and the fluorescence quantum yield at this time was measured.

[0153] Synthesis Example 1 In Synthesis Example 1, a synthesis method for compound R-1 will be 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 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-(2-methoxybenzoyl)-3-(o-tolyl)-5-phenylpyrrole (2.48 g).

[0154] Next, a mixed solution of the obtained 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) was heated at 125°C for 7 hours under a nitrogen stream. After cooling this mixed solution to room temperature, water (32 mL) was poured into it, 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, followed by filtration. The solvent was removed from the obtained filtrate using an evaporator, yielding a pyrromethene derivative as a residue. Next, diisopropylethylamine (1.62 mL) and boron trifluoride diethyl ether complex (2.39 mL) were added to a mixed solution of the obtained pyrromethene compound and toluene (32 mL) under a nitrogen stream, and the mixture was stirred at 80°C for 1 hour. Subsequently, water (32 mL) was poured 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) and 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 in vacuo to obtain a reddish-purple powder (1.48 g).

[0155] The resulting reddish purple powder １ The results of H-NMR analysis are as follows, and it was confirmed that the reddish purple powder obtained above was compound R-1. Spirofluorene indenopyrrole was synthesized with reference to known methods described in Org. Lett., Vol. 12, pp. 296 (2010), etc. 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)

[0156]

[0157] Compounds other than those mentioned above can also be easily synthesized by changing various raw materials such as pyrrole and benzoyl chloride.

[0158] Example 1 In Example 1, polymethyl methacrylate resin "BR-88" (manufactured by Mitsubishi Chemical Corporation) was used as the binder resin, and 1.1 parts by weight of compound R-1 as the luminescent material and 200 parts by weight of ethyl acetate as the solvent (dissolving agent) were mixed with 100 parts by weight of this polymethyl methacrylate resin. Thereafter, this mixture was stirred and degassed for 20 minutes at 1000 rpm using a planetary stirring and degassing device "Mazerustar KK-400" (manufactured by Kurabo Industries, Ltd.). This resulted in a color-changing composition (red color-changing composition) as a resin liquid for sheet production.

[0159] Next, the red color-converting composition obtained above was applied to a polyester film "Lumirror" (registered trademark) U48 (manufactured by Toray Industries, Inc., thickness 50 μm) using a slit die coater, and then heated and dried at 140°C for 20 minutes. This resulted in a red color-converting sheet having an average film thickness of 18 μm. The fluorescence quantum yield of this red color-converting sheet was measured and found to be 90%. The evaluation results of Example 1 are summarized in Table 1, along with the measurement results of the spectrum of Compound R-1, etc.

[0160] (Examples 2 to 13 and Comparative Examples 1 to 4) In each of Examples 2 to 13 and Comparative Examples 1 to 4, a color conversion sheet was produced and evaluated in the same manner as in Example 1, except that the compounds shown in Table 1 were used as the luminescent material. 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, etc.

[0161]

[0162] A comparison of Examples 1 to 13 with Comparative Example 1 shows that the introduction of a fused ring structure into the pyrromethene skeleton reduces the half-width and enables emission of light with high color purity. Furthermore, a comparison of Examples 1 to 13 with Comparative Example 2 shows that the introduction of a fused ring structure into the pyrromethene skeleton on one side results in a larger Stokes shift than when the fused ring structure is on both sides. Furthermore, a comparison of Examples 1 to 13 with Comparative Examples 3 and 4 shows that the R 1 and R 3 are different aryl groups, the fluorescence quantum yield of the color conversion sheet is improved.

[0163] In addition, when comparing Examples 1 to 13, the above R 1 and R 3 are different phenyl groups, the fluorescence quantum yield is higher, and 1 When R is a phenyl group having a substituent at the ortho position, the fluorescence quantum yield is higher. 1 Among phenyl groups having a substituent at the ortho position, those in which the substituent is an electron-withdrawing group have a larger Stokes shift.

[0164] As described above, the pyrromethene boron complex, color-converting composition, color-converting sheet, color-converting 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.

[0165] 1A, 1B, 1C, 1D Color conversion sheet 10 Base layer 11 Color conversion layer 12 Barrier film

Claims

1. The compound is represented by the following general formula (1), In the above general formula (1) or the following general formulas (2A) to (2D), at least one of R1 to R3, R101, R102, R201 to R204 and Ar includes an electron-withdrawing group. The electron-withdrawing group is a fluorine-containing aryl group, a fluorine-containing heteroaryl group, a fluorine-containing alkyl group, or a substituted or unsubstituted sulfonyl group. A pyrometenboron complex characterized by the following: 【Chemistry 1】 (In general formula (1), X is C-R 7 or N. R 1 and R 3 are aryl groups different from each other. R 2 and R 4 to R 9 may be the same or different at each occurrence, 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, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, and a phosphine oxide group; provided that one of the two pairs of the pair of R 4 and R 5 , and the pair of R 5 and R 6 is a ring structure represented by any one of the following general formulas (2A) to (2D).) 【Chemistry 2】 (In general formulas (2A) to (2D), R 101 , R 102 and R 201 ~R 204 R in the general formula (1) is 2 and R 4 ~R 9 This is synonymous with Ar, which is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocycle. 101 and R 102 This may form a ring. (* indicates the connection point with the pyromethene skeleton.)

2. The compound represented by the general formula (1) is a compound represented by any one of the following general formulas (3A) to (3D): The pyrometenboron complex according to feature 1. 【Transformation 3】 (In general formulas (3A) to (3D), R 101 and R 102 R in the general formula (1) is 2 and R 4 ~R 9 This is synonymous with Ar, which is a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocycle. 101 and R 102 (These may form a ring.)

3. The Ar is a substituted or unsubstituted benzene ring. The pyrometenboron complex according to feature 1.

4. R in the general formula (1) 1 and R 3 However, they are phenyl groups that are differently substituted or unsubstituted from each other. The pyrometenboron complex according to feature 1.

5. R in the general formula (1) 1 However, it is a phenyl group having a substituent in the ortho position. The pyrometenboron complex according to feature 1.

6. R in the general formula (1) 1 ~R 3 At least one of them is a group containing an electron-withdrawing group. The pyrometenboron complex according to feature 1.

7. In the general formula (1), X is CR 7 And R 7 However, the group is represented by the following general formula (4), The pyrometenboron complex according to feature 1. 【Chemistry 4】 (In general formula (4), r is selected from the group consisting of hydrogen atom, alkyl group, cycloalkyl group, heterocyclic group, alkenyl group, cycloalkenyl group, alkynyl group, hydroxyl group, thiol group, alkoxy group, alkylthio group, aryl ether group, arylthioether group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, boryl group, and phosphine oxide group. k is an integer from 1 to 3. If k is 2 or greater, r may be the same or different.)

8. The compound represented by the general formula (1) exhibits emission observed in the region of peak wavelength between 580 nm and 750 nm when excitation light is used. The pyrometenboron complex according to feature 1.

9. A color conversion composition that converts incident light into light with a longer wavelength than the incident light, The pyrometenboron complex according to claim 1, Binder resin and A color conversion composition characterized by containing the following:

10. A color conversion layer comprising the color conversion composition or cured product thereof as described in claim 9, A color conversion sheet characterized by the following features.

11. A color conversion substrate comprising multiple color conversion layers on a transparent substrate, The plurality of color conversion layers are layers made of the color conversion composition or a cured product thereof according to claim 9. A color conversion substrate characterized by the following features.

12. Light source and A color conversion sheet according to claim 10 or a color conversion substrate according to claim 11, A light source unit characterized by comprising the following features.

13. The light source is a light-emitting diode that has maximum emission in the wavelength range of 430 nm to 500 nm. The light source unit according to claim 12, characterized by the features described above.

14. A color conversion sheet according to claim 10 or a color conversion substrate according to claim 11 is provided. A display device characterized by the following features.

15. A color conversion sheet according to claim 10 or a color conversion substrate according to claim 11 is provided. A lighting device characterized by the following features.

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