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

Abstract

To achieve both improvement of color reproducibility and improvement of durability in a color conversion composition and a color conversion member used for a light source unit, a display, and a lighting device, and in particular, to achieve both light emission with high color purity and high durability.SOLUTION: A color conversion composition includes at least one organic light-emitting material and a binder resin, and satisfies the following expression (a- 1). Wherein, in the formula (A-1), EF represents an energy at a peak wavelength of a fluorescence emission spectrum of the at least one organic light-emitting material in a dilute toluene solution. EP represents an energy at a peak wavelength of a phosphorescence emission spectrum of the at least one organic light-emitting material in a dilute toluene solution. ) SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

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

[0003] By forming this composition with color conversion 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., white light. By combining such a blue light source with a sheet with color conversion function (hereinafter referred to as color conversion sheet) to form a white light source unit such as a backlight unit, and combining this light source unit with a liquid crystal driver 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 (lighting device) such as an LED light source.

[0004] Issues facing displays that utilize color conversion methods include improving color reproducibility and durability. 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 using quantum dots as a component of a color-converting composition has been proposed (see, for example, Patent Document 1). Color-converting materials containing organic light-emitting materials have also been proposed (see, for example, Patent Documents 2 and 3). Furthermore, examples of techniques for preventing deterioration of organic light-emitting materials and improving their durability have been proposed, such as a technique for adding a light stabilizer (see, for example, Patent Document 4) and a technique for improving durability by using an oxygen barrier (see, for example, Patent Document 5). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-22028 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-61824 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-136771 [Patent Document 4] Japanese Patent Application Publication No. 2019-50381 [Patent Document 5] International Publication No. 2017 / 057287 Summary of the Invention [Problem to be solved by the invention]

[0006] The technology using quantum dots described in Patent Document 1 certainly narrows the half-width of the green and red emission spectra, improving color reproducibility. However, quantum dots are vulnerable to heat, moisture, and oxygen in the air, and have insufficient durability. Furthermore, there are issues such as the inclusion of cadmium.

[0007] Furthermore, in recent years, with the trend toward higher resolutions such as 4K and 8K, high dynamic range (HDR), and higher contrast due to local dimming, the illuminance required of display light source units has increased. This has resulted in higher temperatures in light source units due to drive heat. While the techniques using organic light-emitting materials described in Patent Documents 2 and 3 can certainly improve color reproducibility, they lack durability at high temperatures. Furthermore, existing techniques such as the light stabilizer described in Patent Document 4 and the oxygen barrier described in Patent Document 5 are effective in improving durability, but are insufficient for improving durability at high temperatures. In particular, color conversion materials using organic light-emitting materials have the problem of significantly deteriorating durability at high temperatures, and the above-mentioned existing techniques have yet to fully resolve this issue.

[0008] The problem to be solved by the present invention is to achieve both improved color reproducibility and durability in a color-converting composition or color-converting member (e.g., a color-converting sheet) used in a light source unit, a display, or a lighting device. That is, an object of the present invention is to provide a color-converting composition and a color-converting member that achieve both high color purity and high durability, and that have improved durability, particularly at high temperatures. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems and achieve the object, the present invention has any one of the following configurations.

[0010] That is, the color-changing composition according to the present invention is characterized in that it is a color-changing composition that contains [1] at least one organic light-emitting material and a binder resin, and satisfies the following formula (A-1):

[0011]

number

[0012] The color-changing composition according to the present invention is characterized in that, in the invention described in [2] above [1], it satisfies the following formula (A-2):

[0013]

number

[0014]

number

[0015] The color-changing composition according to the present invention is characterized in that, in the invention described in [3] or [2] above, it satisfies the following formula (A-4):

[0016]

number

[0017] The color-changing composition according to the present invention is characterized in that, in the invention described in any one of the above items [1] to [3], it satisfies the following formula (A-5):

[0018]

number

[0019] The color-converting composition of the present invention is characterized in that, in the invention described in any one of [1] to [4] above, the peak wavelength of the fluorescent emission spectrum of the at least one organic light-emitting material in a dilute toluene solution is in a wavelength range of 500 nm or more.

[0020] The color conversion member of the present invention is characterized in that, in the invention described in any one of [1] to [5] above, it is a color conversion member comprising at least one organic light-emitting material and a binder resin, and satisfies the following formula (A-1):

[0021]

number

[0022] [7] The color conversion member according to the present invention is characterized in that, in the invention described in [6] above, it satisfies the following formula (A-6):

[0023]

number

[0024] [8] The color conversion member according to the present invention is characterized in that, in the invention described in [6] or [7] above, the following formula (A-7) is satisfied.

[0025]

number

[0026]

number

[0027] [9] The color conversion member according to the present invention is characterized in that, in the invention described in any one of the above [6] to [8], the color conversion member satisfies the following formula (A-9):

[0028]

number

[0029]

[10] The color conversion member according to the present invention is characterized in that, in the invention described in any one of the above [6] to [9], the color conversion member satisfies the following formula (A-5):

[0030]

number

[0031] Furthermore, the color conversion member of the present invention is characterized in that, in the invention described in any one of the above [6] to

[10] , the peak wavelength of the fluorescent emission spectrum of the at least one organic light-emitting material in a dilute toluene solution is in a wavelength range of 500 nm or more.

[0032]

[12] The color conversion member according to the present invention is characterized in that, in the invention described in any one of the above [6] to

[11] , it has an oxygen barrier layer.

[0033]

[0023] Also, a light source unit according to the present invention is characterized by comprising:

[13] a light source; and the color conversion member according to any one of [6] to

[12] above.

[0034]

[14] A display according to the present invention is characterized by comprising the light source unit according to

[13] above.

[0035]

[15] The lighting device according to the present invention is characterized by comprising the light source unit according to

[13] above. [Effects of the Invention]

[0036] The color-converting composition of the present invention and the color-converting member using the same can achieve both high color purity and high durability, even at high temperatures, and therefore have the effect of enabling both improved color reproducibility and improved durability to be achieved. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a first example of a color conversion member according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing a second example of a color conversion member according to an embodiment of the present invention. [Figure 3] FIG. 3 is a schematic cross-sectional view showing a third example of a color conversion member according to an embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a fourth example of a color conversion member according to an embodiment of the present invention. [Figure 5] FIG. 5 is a schematic cross-sectional view showing a fifth example of a color conversion member according to an embodiment of the present invention. [Figure 6] FIG. 6 is a schematic cross-sectional view showing a sixth example of a color conversion member according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0038] Hereinafter, preferred embodiments of the color-converting composition, color-converting member, and light source unit, display, and lighting device containing the same according to the present invention will be specifically described, but the present invention is not limited to the following embodiments and can be modified in various ways depending on the purpose and application. Furthermore, matters cited as preferred examples in specific embodiments and implementations can also be applied to other embodiments and implementations.

[0039] <Color-changing composition and color-changing member> A color-converting composition according to an embodiment of the present invention (hereinafter sometimes abbreviated as the color-converting composition of the present invention) contains at least one organic light-emitting material and a binder resin. Also, a color-converting member according to an embodiment of the present invention (hereinafter sometimes abbreviated as the color-converting member of the present invention) contains the color-converting composition of the present invention or a cured product thereof. That is, the color-converting member of the present invention contains at least one organic light-emitting material and a binder resin, similar to the color-converting composition of the present invention.

[0040] <Light-emitting materials> The color-converting composition and color-converting member of the present invention each contain at least one organic light-emitting material. Here, the term "light-emitting material" as used herein refers to a material that, when irradiated with a certain type of light, emits light of a wavelength different from that light. Examples of light-emitting materials include inorganic phosphors, fluorescent pigments, fluorescent dyes, quantum dots, and organic light-emitting materials. Among these, organic light-emitting materials are superior to other light-emitting materials in terms of uniformity of dispersion, reduced usage, and reduced environmental impact.

[0041] In each of the color-converting composition and color-converting member of the present invention, the organic light-emitting material contained therein satisfies the following formula (A-1).

[0042]

number

[0043] In formula (A-1), E FE represents the energy at the peak wavelength of the fluorescence emission spectrum of the at least one organic light-emitting material in a dilute toluene solution. P represents the energy at the peak wavelength of the phosphorescent emission spectrum of the at least one organic light-emitting material in a dilute toluene solution. em [nm] and energy E hv Conversion to [eV] is E hv =1240 / λ em This can be done using the formula:

[0044] In each of the color-converting compositions and color-converting members, when the organic light-emitting material contained therein satisfies formula (A-1), the energy levels of the organic light-emitting material in the singlet excited state and the organic light-emitting material in the triplet excited state are close to each other. Therefore, thermal energy derived from the heat generated by the operation of a device such as a light source unit can cause reverse intersystem crossing from the organic light-emitting material in the triplet excited state to the organic light-emitting material in the singlet excited state. Because organic light-emitting materials in the triplet excited state are highly reactive and have a long lifetime, they are prone to react with surrounding molecules. This is one of the main causes of deterioration (e.g., oxidative deterioration) of organic light-emitting materials. Therefore, the aforementioned reverse intersystem crossing is effective in improving the durability of color-converting compositions and color-converting members containing such organic light-emitting materials. In each of the color-converting compositions and color-converting members of the present invention, the organic light-emitting material contained therein satisfies formula (A-1). Therefore, the aforementioned reverse intersystem crossing can occur more quickly than the organic light-emitting material deteriorates, for example, in a high-temperature environment elevated from room temperature by the aforementioned thermal energy.

[0045] It is preferable that the reverse intersystem crossing occurs faster than the deterioration of the organic light-emitting material. F -E P The smaller the value of E, the better. F -E P The value of E is more preferably 0.020 eV or less, even more preferably 0.015 eV or less, and particularly preferably 0.010 eV or less. F -E PThe value of E can be negative. In this case, the reverse intersystem crossing described above is energetically dominant, and reverse intersystem crossing occurs very quickly, which is preferable. F -E P The lower limit of the value is not particularly limited, but is preferably −0.030 eV or more.

[0046] Furthermore, organic light-emitting materials satisfying formula (A-1) are preferred because they can exhibit highly efficient light emission. Typically, fluorescent light is emitted from a light-emitting material in a singlet excited state, which is generated after the light-emitting material is photoexcited. A light-emitting material in a triplet excited state, generated by intersystem crossing, is thermally deactivated at room temperature. Therefore, fluorescent light is not emitted from the light-emitting material in the triplet excited state. On the other hand, organic light-emitting materials satisfying formula (A-1) quickly convert the triplet excited state into a singlet excited state and then emit fluorescence. Therefore, organic light-emitting materials in a triplet excited state, which cannot contribute to light emission in ordinary fluorescent light-emitting materials, can also contribute to fluorescent light emission. Therefore, highly efficient light emission can be obtained from organic light-emitting materials satisfying formula (A-1).

[0047] The color-changing composition of the present invention preferably further satisfies the following formula (A-2): That is, it is more preferable that the organic light-emitting material contained in the color-changing composition of the present invention satisfies formula (A-2).

[0048]

number

[0049] In formula (A-2), E RISC represents the activation energy of reverse intersystem crossing of the at least one organic light-emitting material contained in a dilute toluene solution in a temperature range of -50°C to 50°C. RISC is a value that can be calculated using the following formula (A-3).

[0050]

number

[0051] In formula (A-3), ln represents the natural logarithm. RISC represents the reverse intersystem crossing rate constant at each temperature of the at least one organic light-emitting material contained in the dilute toluene solution. T represents the temperature [K] of the dilute toluene solution containing the at least one organic light-emitting material. k B represents the Boltzmann constant. E in Equation (A-2) RISC is the reverse intersystem crossing rate constant k at each temperature T RISC After calculating, use equation (A-3) to set the vertical axis to lnk RISC T 0.5 The horizontal axis is 1 / T, and the lnk RISC T 0.5 Plot the values ​​of the plotted lnk RISC T 0.5 lnA can be obtained by looking up the slope of the approximate line based on the value of lnA. lnA can be obtained from the intersection of the approximate line and the vertical axis at 1 / T=0.

[0052] Here, equation (A-3) is derived from equations (A-10) and (A-11) below, with reference to Nature Communications volume 11, 3909 (2020) and the like.

[0053]

number

[0054] In equations (A-10) and (A-11), h represents Planck's constant. SO represents the spin-orbit interaction between the triplet and singlet excited states, and λ represents the reorganization energy.

[0055] When the color-converting composition of the present invention satisfies formula (A-2), the activation energy of reverse intersystem crossing can be exceeded by thermal energy derived from the heat generated by the operation of a device such as a light source unit in the organic light-emitting material contained in the color-converting composition, and reverse intersystem crossing from the organic light-emitting material in the triplet excited state to the organic light-emitting material in the singlet excited state is likely to occur. Therefore, it is more preferable that the color-converting composition of the present invention satisfies formula (A-2). As mentioned above, the triplet excited state of an organic light-emitting material is one of the main causes of deterioration of the organic light-emitting material, and therefore the aforementioned reverse intersystem crossing is effective in improving the durability of a color-converting composition containing such an organic light-emitting material. It is preferable that this reverse intersystem crossing occurs earlier than the deterioration of the organic light-emitting material. That is, in formula (A-2), E RISC The smaller the value of E, the better. RISC The value of E is more preferably 0.028 eV / mol or less, even more preferably 0.026 eV / mol or less, and particularly preferably 0.024 eV / mol or less. RISC The lower limit of the value is not particularly limited, but is preferably 0.000 eV or more.

[0056] The color-changing composition of the present invention preferably further satisfies the following formula (A-4): That is, it is more preferable that the organic light-emitting material contained in the color-changing composition of the present invention satisfies formula (A-4).

[0057]

number

[0058] In formula (A-4), k RISC (30°C) denotes the rate constant of reverse intersystem crossing of the at least one organic light-emitting material in a dilute toluene solution at 30°C.

[0059] When the color-converting composition of the present invention satisfies formula (A-4), reverse intersystem crossing from the triplet excited state to the singlet excited state of the organic light-emitting material contained in the color-converting composition can occur at a sufficiently high speed in the temperature range in which the color-converting composition is actually used (the actual use temperature range). Therefore, it is possible to further suppress the deterioration of the organic light-emitting material in a high-temperature environment. RISC (30℃) is 0.70×10 5 s -1 More preferably, it is 1.0×10 or more. 5 s -1 More preferably, it is 1.2×10 or more. 5 s -1 It is particularly preferable that k is equal to or greater than k. RISC The higher the value of (30°C), the better. The upper limit is not particularly limited, but is preferably 1.0 × 10 10 s -1 It is preferable that:

[0060] The color conversion member of the present invention preferably further satisfies the following formula (A-6): That is, it is more preferable that the organic light-emitting material contained in the color conversion member of the present invention satisfies formula (A-6).

[0061]

number

[0062] In formula (A-6), E' F E' represents the energy at the peak wavelength of the fluorescence emission spectrum of the color conversion member. P represents the energy at the peak wavelength of the phosphorescent emission spectrum of the color conversion member.

[0063] As described above, the color conversion member of the present invention contains at least one organic light-emitting material and a binder resin, and therefore the organic light-emitting material in the color conversion member is in a different environment from the organic light-emitting material in solution. When the color conversion member of the present invention satisfies formula (A-6) in addition to formula (A-1), the organic light-emitting material in the color conversion member can undergo reverse intersystem crossing from a triplet excited state to a singlet excited state at a rate sufficiently faster than the deterioration of the organic light-emitting material. This makes it possible to further suppress the deterioration of the organic light-emitting material in a high-temperature environment. It is preferable that this reverse intersystem crossing occurs more quickly than the deterioration of the organic light-emitting material in the color conversion member (in the binder resin). That is, in formula (A-6), E' F -E' P The smaller the value of E' is, the better. F -E' P The value of E' is more preferably 0.020 eV or less, even more preferably 0.015 eV or less, and particularly preferably 0.010 eV or less. F -E' P The value of E' can be negative. In this case, the reverse intersystem crossing described above is energetically dominant, and reverse intersystem crossing occurs very quickly, which is preferable. F -E' P The lower limit of the value is not particularly limited, but is preferably −0.030 eV or more.

[0064] The color conversion member of the present invention preferably further satisfies the following formula (A-7): That is, it is more preferable that the organic light-emitting material contained in the color conversion member of the present invention satisfies formula (A-7).

[0065]

number

[0066] In formula (A-7), E' RISC represents the activation energy of reverse intersystem crossing of the at least one organic light-emitting material contained in the color conversion member in the temperature range of -50°C to 50°C. RISCis a value that can be calculated using the following formula (A-8).

[0067]

number

[0068] In equation (A-8), ln represents the natural logarithm. RISC represents the rate constant of reverse intersystem crossing at each temperature of at least one organic light-emitting material contained in the color conversion member. T' represents the temperature [K] of the color conversion member containing at least one organic light-emitting material. k B represents the Boltzmann constant. E' in Equation (A-7) RISC is the reverse intersystem crossing rate constant k' at each temperature T' RISC After calculating, use equation (A-8) to set the vertical axis to lnk' RISC T' 0.5 The horizontal axis is 1 / T', and the lnk' at each temperature T' RISC T' 0.5 Plot the values ​​of lnk' RISC T' 0.5 lnA' can be found by looking up the slope of the approximate line based on the value of 1 / T'. lnA' can be found from the intersection of the approximate line and the vertical axis at 1 / T' = 0. Here, equation (A-8) is derived in the same way as equation (A-3) above.

[0069] When the color conversion member of the present invention satisfies formula (A-7), the activation energy of reverse intersystem crossing can be exceeded in the organic light-emitting material contained in the color conversion member by thermal energy derived from the heat generated by the operation of a device such as a light source unit, and reverse intersystem crossing from the organic light-emitting material in the triplet excited state to the organic light-emitting material in the singlet excited state is likely to occur. Therefore, it is more preferable that the color conversion member of the present invention satisfies formula (A-7). As mentioned above, the triplet excited state of an organic light-emitting material is one of the main causes of deterioration of the organic light-emitting material, and therefore the aforementioned reverse intersystem crossing is effective in improving the durability of a color conversion member containing such an organic light-emitting material. It is preferable that this reverse intersystem crossing occurs earlier than the deterioration of the organic light-emitting material. That is, in formula (A-7), E' RISC The smaller the value of E' is, the better. RISC The value of E' is more preferably 0.028 eV / mol or less, even more preferably 0.026 eV / mol or less, and particularly preferably 0.024 eV / mol or less. RISC The lower limit of the value is not particularly limited, but is preferably 0.000 eV or more.

[0070] The color conversion member of the present invention preferably further satisfies the following formula (A-9): That is, it is more preferable that the organic light-emitting material contained in the color conversion member of the present invention satisfies formula (A-9).

[0071]

number

[0072] In formula (A-9), k' RISC (30°C) represents the rate constant of reverse intersystem crossing at 30°C of the at least one organic light-emitting material contained in the color conversion member.

[0073] When the color conversion member of the present invention satisfies formula (A-9), reverse intersystem crossing from the triplet excited state to the singlet excited state of the organic light-emitting material contained in the color conversion member can occur sufficiently fast in the temperature range (actual use temperature range) in which the color conversion member is actually used. Therefore, it is possible to further suppress deterioration of the organic light-emitting material in a high-temperature environment. RISC (30℃) is 0.70×10 5 s -1 More preferably, it is 1.0×10 or more. 5 s -1 More preferably, it is 1.2×10 or more. 5 s -1 It is particularly preferable that k' is equal to or greater than this. RISC The higher the value of (30°C), the better. The upper limit is not particularly limited, but is preferably 1.0 × 10 10 s -1 It is preferable that:

[0074] Each of the color-converting composition and color-converting member of the present invention preferably further satisfies the following formula (A-5): That is, in each of the color-converting composition and color-converting member of the present invention, it is more preferable that the organic light-emitting material contained therein satisfies formula (A-5).

[0075]

number

[0076] In formula (A-5), Δy is the absolute value of the change in chromaticity y from the initial value in the xy coordinates of the color-converted transmitted light when light from a blue LED with a peak wavelength in the range of 450 nm ± 3 nm and an intensity of 8000 nit is continuously irradiated for 200 hours. Δy(75°C) represents Δy when the continuous light irradiation is performed while keeping the temperature at 75°C. Δy(30°C) represents Δy when the continuous light irradiation is performed while keeping the temperature at 30°C.

[0077] When the color-converting composition and color-converting member of the present invention satisfy formula (A-5), reverse intersystem crossing from the triplet excited state to the singlet excited state of the organic light-emitting material can occur sufficiently rapidly in the practical use temperature range. Therefore, the color-converting composition and color-converting member of the present invention can exhibit durability equal to or greater than that at low temperatures, even in high-temperature environments caused by the heat generated by the operation of devices such as light source units. Furthermore, when the color-converting composition or color-converting member is used in light source units, displays, or lighting devices, it is possible to suppress the accelerated deterioration of the organic light-emitting material due to high temperatures. The value of Δy(75°C) / Δy(30°C) is more preferably 0.80 or less, and particularly preferably 0.50 or less.

[0078] <Organic light-emitting materials> Examples of organic light-emitting materials that can be used in the color-converting composition and color-converting member of the present invention include the following: Suitable organic light-emitting materials include compounds having a fused aryl ring, such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene, as well as derivatives thereof. Suitable organic light-emitting materials also include compounds having a heteroaryl ring, such as furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, and pyrrolopyridine, as well as derivatives thereof, and borane derivatives.

[0079] Other suitable organic light-emitting materials include stilbene derivatives such as 1,4-distyrylbenzene, 4,4'-bis(2-(4-diphenylaminophenyl)ethenyl)biphenyl, and 4,4'-bis(N-(stilben-4-yl)-N-phenylamino)stilbene, aromatic acetylene derivatives, tetraphenylbutadiene derivatives, aldazine derivatives, pyrromethene derivatives, and diketopyrrolo[3,4-c]pyrrole derivatives. Other suitable organic light-emitting materials include coumarin derivatives such as coumarin 6, coumarin 7, and coumarin 153; azole derivatives and metal complexes thereof such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, and triazole; cyanine compounds such as indocyanine green; and xanthene and thioxanthene compounds such as fluorescein, eosin, and rhodamine.

[0080] Suitable organic light-emitting materials include polyphenylene compounds, naphthalimide derivatives, phthalocyanine derivatives and their metal complexes, porphyrin derivatives and their metal complexes, oxazine compounds such as Nile Red and Nile Blue, helicene compounds, and aromatic amine derivatives such as N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine. Suitable organic light-emitting materials include organometallic complex compounds of iridium (Ir), ruthenium (Ru), rhodium (Rh), palladium (Pd), platinum (Pt), osmium (Os), europium (Eu), and rhenium (Re). However, the organic light-emitting material of the present invention is not limited to the above. The organic light-emitting material of the present invention may be a fluorescent material or a phosphorescent material.

[0081] One embodiment of the organic light-emitting material in the present invention is an organic light-emitting material containing a compound having a partial structure represented by general formula (1).

[0082] [ka]

[0083] In general formula (1), B is a boron atom, N is a nitrogen atom, and C is a carbon atom. n is an integer of 0 to 2. When n is 0, the partial structure represented by general formula (1) is a direct bond structure between B and N.

[0084] Compounds having a partial structure represented by general formula (1) exhibit high color purity due to the interaction between a Lewis acidic boron atom and a Lewis basic nitrogen atom. Furthermore, in compounds having a partial structure represented by general formula (1), the electron-donating nitrogen atom and the electron-accepting boron atom are closely positioned within the molecule. Compounds having such a partial structure are capable of separating the HOMO (highest occupied molecular orbital) orbital and the LUMO (lowest unoccupied molecular orbital) orbital through the multiple resonance effect. Organic light-emitting materials containing such compounds can bring the energy levels of the singlet excited state and the triplet excited state closer together. To clearly separate the HOMO orbital and the LUMO orbital, thereby bringing the energy levels of the singlet excited state and the triplet excited state of the organic light-emitting material closer together, the organic light-emitting material preferably has two or more partial structures represented by general formula (1) within the molecule.

[0085] Another embodiment of the organic light-emitting material in the present invention is an organic light-emitting material containing at least one of a compound represented by general formula (2) and a compound represented by general formula (3).

[0086] [ka]

[0087] In general formula (2) or (3), ring Za, ring Zb, and ring Zc are each independently a substituted or unsubstituted aryl ring having 5 to 30 ring members, or a substituted or unsubstituted heteroaryl ring having 5 to 30 ring members.

[0088] In general formula (2), Z 1 and Z 2 are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom. 1 When R is NRa, the substituent R may be bonded to the ring Z or the ring Z to form a ring. 2 When R is NRa, the substituent R may be bonded to the ring Z or the ring Zc to form a ring. E is a boron atom, a phosphorus atom, SiRa (a silicon atom having a substituent R) or P=O.

[0089] In general formula (3), E 1 and E 2 are each independently BRa (a boron atom having a substituent Ra), PRa (a phosphorus atom having a substituent Ra), SiRa2 (a silicon atom having two substituents Ra), P(=O)Ra2 (a phosphine oxide having two substituents Ra) or P(=S)Ra2 (a phosphine sulfide having two substituents Ra), C=O (a carbonyl group), S(=O) or S(=O)2. E 1 When is BRa, PRa, SiRa2, P(=O)Ra2 or P(=S)Ra2, the substituent Ra may be bonded to ring Za or ring Zb to form a ring. 2 When is BRa, PRa, SiRa2, P(=O)Ra2 or P(=S)Ra2, the substituent Ra may be bonded to ring Za or ring Zc to form a ring.

[0090] The substituents R are each independently 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, an aryl group, a heteroaryl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, a halogen atom, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, an ester group, a carbamoyl group, an amide group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, an amino group, an imino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, a phosphine oxide group, and a fused ring or aliphatic ring formed between adjacent substituents. The substituent R may be further substituted with a substituent selected from these groups. The substituent R may be further substituted with a substituent selected from these groups.

[0091] Still another embodiment of the organic light-emitting material of the present invention is an organic light-emitting material containing a compound represented by general formula (4).

[0092] [ka]

[0093] In general formula (4), ring Zd, ring Ze, ring Zf, ring Zg, ring Zh, and ring Zi are each independently a substituted or unsubstituted aryl ring having 5 to 30 ring members, or a substituted or unsubstituted heteroaryl ring having 5 to 30 ring members.

[0094] In addition, in the general formula (4), Z 3 and Z 4 are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom. 3 When R is NRa, the substituent R may be bonded to the ring Zd or the ring Ze to form a ring. 4is NRa, the substituent Ra may be bonded to the ring Zh or the ring Zi to form a ring, provided that the substituent Ra is the same as the substituent Ra in the above general formula (2) or (3).

[0095] R C is a group selected from a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, a halogen atom, a cyano group, an aldehyde group, a carboxy group, an ester group, an amide group, an acyl group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, a nitro group, a silyl group, a siloxanyl group, a boryl group, and a phosphine oxide group. The selected group may form a ring structure with an adjacent group.

[0096] 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 6 to 40 carbon atoms, including the number of carbon atoms contained in the substituents substituted on the aryl group. The same applies to other substituents that specify the number of carbon atoms.

[0097] 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.

[0098] In addition, in all of the above groups, examples of the substituent when substituted include an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, a halogen atom, a cyano group, an aldehyde group, a carbonyl group, a carboxy group, an oxycarbonyl group, an ester group, a carbamoyl group, an amide group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, an imino group, an amino group, a nitro group, a silyl group, a siloxanyl group, a boryl group, or a phosphine oxide group. In addition, these substituents may be further substituted with the above-mentioned substituents.

[0099] The alkyl group refers to a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group, which may or may not have a substituent. When substituted, the additional substituent is not particularly limited, and examples thereof include an alkyl group, a halogen, an aryl group, and a heteroaryl group, which also applies to the following description. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably in the range of 1 to 20, more preferably 1 to 8, in terms of availability and cost.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] The aryl ether group refers to a functional group in 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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. Heteroaryl groups include cyclic aromatic groups 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, and a phenanthrolinyl group. The naphthyridinyl group refers to a 1,5-naphthyridinyl group, a 1,6-naphthyridinyl group, a 1,7-naphthyridinyl group, a 1,8-naphthyridinyl group, a 2,6-naphthyridinyl group, or a 2,7-naphthyridinyl group. The heteroaryl group may or may not have a substituent. The number of carbon atoms in the heteroaryl group is not particularly limited, but is preferably in the range of 2 or more and 40 or less, and more preferably 2 or more and 30 or less.

[0113] As the heteroaryl group, a pyridyl group, a furanyl group, a thienyl group, a quinolinyl group, a pyrimidyl group, a triazinyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a dibenzofuranyl group, a dibenzothienyl group, a carbazolyl group, a benzimidazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, or a phenanthrolinyl group is preferred, and a pyridyl group, a furanyl group, a thienyl group, or a quinolinyl group is more preferred, and a pyridyl group is particularly preferred.

[0114] 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.

[0115] The term "halogen" refers to an atom selected from fluorine, chlorine, bromine, and iodine. The carbonyl group, carboxy group, oxycarbonyl group, ester group, carbamoyl group, amide group, and imino group may or may not have a substituent. Examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, and a heteroaryl group, and these substituents may be further substituted.

[0116] The sulfonyl group, sulfonate group, and sulfonamide group are each represented by -S(=O)R 10 , -S(=O)2OR 10 , -S(=O)2NR 10 R 11 These R 10 and R 11 are each selected from the same group as the hydrogen atom or the substituents when substituted as described above.

[0117] The amino group is a substituted or unsubstituted amino group. In the case of substitution, examples of the substituent include an aryl group, a heteroaryl group, a linear alkyl group, and a branched alkyl group. Preferred aryl and heteroaryl groups are a phenyl group, a naphthyl group, a pyridyl group, and a quinolinyl group. These substituents may be further substituted. The number of carbon atoms is not particularly limited, but is preferably in the range of 2 to 50, more preferably 6 to 40, and particularly preferably 6 to 30.

[0118] The silyl group refers to, for example, alkylsilyl groups such as trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, propyldimethylsilyl, and vinyldimethylsilyl, and arylsilyl groups such as phenyldimethylsilyl, tert-butyldiphenylsilyl, triphenylsilyl, and trinaphthylsilyl. The substituent on the silicon atom may be further substituted. The number of carbon atoms in the silyl group is not particularly limited, but is preferably in the range of 1 to 30.

[0119] 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. 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 these, an aryl group and an aryl ether group are preferred.

[0120] The phosphine oxide group is -P(=O)R 10 R 11 The R of the phosphine oxide group is 10 and R 11 are each selected from the same group as the hydrogen atom or the substituents when substituted as described above.

[0121] In addition, in each of the compounds having a structure represented by general formula (2), the compounds having a structure represented by general formula (3), and the compounds having a structure represented by general formula (4), any two adjacent substituents may be bonded to each other to form a conjugated or non-conjugated fused ring or aliphatic ring. The constituent elements of such a fused ring or aliphatic ring may include, in addition to carbon, an element selected from nitrogen, oxygen, sulfur, phosphorus, and silicon. Furthermore, the fused ring or aliphatic ring may be further fused with another ring.

[0122] Each of the compound having a structure represented by general formula (2), the compound having a structure represented by general formula (3), and the compound having a structure represented by general formula (4) exhibits light emission with high color purity due to the interaction between the electron donor atom and the electron acceptor atom.

[0123] In addition, in each of the compounds having a structure represented by general formula (2), the compounds having a structure represented by general formula (3), and the compounds having a structure represented by general formula (4), the electron donor atom and the electron acceptor atom are located close to each other in the molecule. Compounds having such partial structures are compounds that can separate the HOMO orbital and the LUMO orbital by the multiple resonance effect. In organic light-emitting materials containing such compounds, the energy levels of the singlet excited state and the triplet excited state can be brought close to each other.

[0124] The compounds represented by general formula (2), general formula (3), and general formula (4) each exhibit high fluorescence quantum yield and have a narrow half-width of the emission spectrum at the peak emission wavelength, and therefore can achieve both efficient color conversion and high color purity.

[0125] Furthermore, various characteristics and physical properties such as luminous efficiency, color purity, thermal stability, light stability, and dispersibility can be adjusted for each of the compounds represented by general formula (2), the compounds represented by general formula (3), and the compounds represented by general formula (4) by introducing appropriate substituents into appropriate positions.

[0126] In each of general formulas (2), (3), and (4), the substituent Ra, including the substituent substituting the substituent Ra, is preferably a group having 6 to 40 carbon atoms. The substituent Ra is preferably a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and more preferably a substituted or unsubstituted aryl group. Examples of the substituted or unsubstituted aryl group include a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted naphthyl group, and a substituted or unsubstituted phenanthrenyl group. Among these, a substituted or unsubstituted phenyl group is more preferred.

[0127] In each of the compounds represented by general formula (2), general formula (3), and general formula (4), when the π-conjugated system thereof is expanded, reverse intersystem crossing from the triplet excited state to the singlet excited state occurs more efficiently, and durability can be further improved, so that the compounds are preferable as the light-emitting material contained in the color conversion material of the present invention. 1 and Z 2 is preferably an oxygen atom or NRa, since the π-conjugated system is efficiently expanded. Similarly, E in general formula (2) is preferably a boron atom, and E in general formula (3) is preferably a fluorine atom, since the π-conjugated system is efficiently expanded. 1 and E 2 is preferably BRa. Similarly, in order to efficiently extend the π-conjugated system, in general formula (4), Z 3 and Z 4 is preferably an oxygen atom or NRa.

[0128] In addition, in general formula (2) and general formula (3), it is preferable that ring Za, ring Zb, and ring Zc are benzene rings, because the π-conjugated system expands efficiently. Similarly, in general formula (4), it is preferable that ring Zd, ring Ze, ring Zf, ring Zg, ring Zh, and ring Zi are benzene rings, because the π-conjugated system expands efficiently. In addition, in general formula (4), it is also preferable that at least one of ring Ze and ring Zh has an aryl group, because the π-conjugated system expands efficiently. In particular, it is preferable that in general formula (4), ring Ze and ring Zh are both benzene rings substituted with substituted or unsubstituted aryl groups.

[0129] In each of the compounds having a structure represented by general formula (2), the compounds having a structure represented by general formula (3), and the compounds having a structure represented by general formula (4), the electron-donating amine nitrogen atom and the electron-accepting boron atom are optimally positioned, as described in, for example, the literature Adv. Mater., 2016, 28, 2777-2781, and it is possible to separate the HOMO orbital and the LUMO orbital by the multiple resonance effect. From the viewpoint of clearly separating the HOMO orbital and bringing the energy levels of the singlet excited state and the triplet excited state closer together, in general formula (2), E is a boron atom with strong electron-accepting properties, and Z 1 and Z 2 and are preferably both NRa, which are groups with strong electron donating properties. 3 and Z 4 and are preferably NRa, which are groups with strong electron donating properties.

[0130] Furthermore, due to the multiple resonance effect, the emission spectra of the compounds having a structure represented by general formula (2), the compounds having a structure represented by general formula (3), and the compounds having a structure represented by general formula (4) are sharper than those of compounds having an electron donor skeleton and an electron acceptor skeleton combined. Therefore, when the light-emitting material contained in the color-converting composition of the present invention is a compound represented by any one of general formulas (2), (3), and (4), light emission with high color purity can be obtained. In other words, the compounds having a structure represented by general formula (2), the compounds having a structure represented by general formula (3), and the compounds having a structure represented by general formula (4) are advantageous for improving the color gamut of displays and are therefore preferred as the light-emitting material.

[0131] Furthermore, in compounds having a structure represented by general formula (2) or general formula (3), rings Za, Zb, and Zc are present around the E atom in general formula (2) or general formula (3) where the LUMO orbital is mainly localized, and therefore the LUMO orbital can be delocalized from the E atom to each ring. By delocalizing the LUMO orbital, the multiple resonance effect works efficiently, resulting in emission of higher color purity. Note that the E atom is the E atom in general formula (2) and the E atom in general formula (3). 1 and E 2 Similarly, in compounds with the structure represented by general formula (4), the LUMO orbital can be delocalized from the boron atom to each ring because rings Zd, Ze, Zf, Zg, Zh, and Zi are present around the boron atom where the LUMO orbital is mainly localized. By delocalizing the LUMO orbital, the multiple resonance effect works efficiently, resulting in emission of higher color purity.

[0132] Furthermore, in general formula (2) and general formula (3), it is more preferable that the substituent Ra forms a structure bonded to at least one of rings Za, ring Zb, and ring Zc, because the substituent Ra forms a structure bonded to at least one of rings Za, ring Zb, and ring Zc, which is similar to E in general formula (2) or E in general formula (3). 1 and E 2Similarly, in general formula (4), it is also preferable that the substituent Ra is bonded to at least one of rings Zd, Ze, Zf, Zg, Zh, and Zi, because this is expected to further enhance the steric protection effect of the boron atom in general formula (4) and further enhance the effect of suppressing a decrease in the fluorescence quantum yield.

[0133] The color-converting composition of the present invention preferably contains the following luminescent material (a). The luminescent material (a) is a luminescent material that, when excited with excitation light having a wavelength in the range of 400 nm to 500 nm, emits light with a peak wavelength observed in the range of 500 nm to less than 580 nm. Hereinafter, the light emitted with a peak wavelength in the range of 500 nm to less than 580 nm will be referred to as "green light" as necessary. Generally, the greater the energy of excitation light, the more likely it is to cause material decomposition. However, excitation light having a wavelength in the range of 400 nm to 500 nm has a relatively small excitation energy. Therefore, green light with good color purity can be obtained without causing decomposition of the luminescent material (a) in the color-converting composition.

[0134] Furthermore, the color-converting composition of the present invention preferably contains the above-mentioned luminescent material (a) and the following luminescent material (b). As described above, the luminescent material (a) is a luminescent material that emits light having a peak wavelength of 500 nm or more and less than 580 nm when excited with excitation light having a wavelength of 400 nm or more and 500 nm or less. The luminescent material (b) is a luminescent material that emits light having a peak wavelength observed in the range of 580 nm or more and 750 nm or less when excited with at least one of excitation light having a wavelength of 400 nm or more and 500 nm or less and the emission from the luminescent material (a). Hereinafter, the emission observed in the peak wavelength range of 580 nm or more and 750 nm or less will be referred to as "red emission" as necessary.

[0135] Because a portion of excitation light in the wavelength range of 400 nm to 500 nm is partially transmitted through the color conversion composition or color conversion member (a member containing the color conversion composition or a cured product thereof) of the present invention, when a blue LED with a sharp emission peak is used, a sharply shaped emission spectrum is exhibited in each of the blue, green, and red colors, resulting in white light with excellent color purity. As a result, a wider color gamut with more vivid colors can be efficiently produced, particularly in displays. Furthermore, in lighting applications, the emission characteristics, particularly in the green and red regions, are improved compared to white LEDs that combine a blue LED with a yellow phosphor, which is currently the mainstream, resulting in a desirable white light source with improved color rendering.

[0136] Examples of the luminescent material (a) include coumarin derivatives such as coumarin 6, coumarin 7, and coumarin 153; cyanine derivatives such as indocyanine green; fluorescein derivatives such as fluorescein, fluorescein isothiocyanate, and carboxyfluorescein diacetate; phthalocyanine derivatives such as phthalocyanine green; perylene derivatives such as diisobutyl-4,10-dicyanoperylene-3,9-dicarboxylate; pyrromethene derivatives, stilbene derivatives, oxazine derivatives, naphthalimide derivatives, pyrazine derivatives, benzimidazole derivatives, benzoxazole derivatives, benzothiazole derivatives, imidazopyridine derivatives, azole derivatives; compounds having a condensed aryl ring such as anthracene and derivatives thereof; aromatic amine derivatives; and organometallic complex compounds. Furthermore, compounds having a partial structure represented by the above-mentioned general formula (1), compounds having a structure represented by general formula (2), compounds having a structure represented by general formula (3), and compounds having a structure represented by general formula (4) also exhibit luminescence with high color purity and are therefore suitable as light-emitting materials contained in the color-converting composition of the present invention. The color-converting composition of the present invention may contain two or more of these as the at least one organic light-emitting material.

[0137] Examples of the luminescent material (b) include cyanine derivatives such as 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostillyl)-4H-pyran, rhodamine derivatives such as rhodamine B, rhodamine 6G, rhodamine 101, and sulforhodamine 101, pyridine derivatives such as 1-ethyl-2-(4-(p-dimethylaminophenyl)-1,3-butadienyl)-pyridinium-perchlorate, perylene derivatives such as N,N'-bis(2,6-diisopropylphenyl)-1,6,7,12-tetraphenoxyperylene-3,4:9,10-bisdicarboimide, porphyrin derivatives, pyrromethene derivatives, oxazine derivatives, pyrazine derivatives, compounds having a fused aryl ring such as naphthacene and dibenzodiindenoperylene, and derivatives thereof, and organometallic complex compounds. Furthermore, compounds having a partial structure represented by the above-mentioned general formula (1), compounds having a structure represented by general formula (2), compounds having a structure represented by general formula (3), and compounds having a structure represented by general formula (4) also exhibit luminescence with high color purity and are therefore suitable as light-emitting materials contained in the color-converting composition of the present invention. The color-converting composition of the present invention may contain two or more of these as the at least one organic light-emitting material.

[0138] In one embodiment of the color-converting composition or color-converting member of the present invention, the peak wavelength of the fluorescent emission spectrum of at least one organic light-emitting material contained in the color-converting composition or color-converting member in a dilute toluene solution is in a wavelength range of 500 nm or more. In this case, the long-term maintenance rate of emission in the green or red region is improved. Therefore, it is preferable that the peak wavelength in the color-converting composition or color-converting member of the present invention is in a wavelength range of 500 nm or more.

[0139] In another embodiment of the color-converting composition or color-converting member of the present invention, the peak wavelength of the fluorescent emission spectrum of at least one organic light-emitting material contained in the color-converting composition or color-converting member in a dilute toluene solution is in the wavelength range of 500 nm or more and less than 580 nm. In this case, the long-term maintenance rate of emission in the green region is improved. Therefore, in the color-converting composition or color-converting member of the present invention, it is preferable that the peak wavelength is in the wavelength range of 500 nm or more and less than 580 nm.

[0140] In yet another embodiment of the color-converting composition or color-converting member of the present invention, the peak wavelength of the fluorescent emission spectrum of at least one organic light-emitting material contained in the color-converting composition or color-converting member in a dilute toluene solution is in the wavelength range of 580 nm or more and less than 750 nm. In this case, the long-term maintenance rate of light emission in the red region is improved. Therefore, in the color-converting composition or color-converting member of the present invention, it is preferable that the peak wavelength is in the wavelength range of 580 nm or more and less than 750 nm.

[0141] As mentioned above, in order to improve color reproducibility, it is preferable that the half-width of the emission spectrum of each of blue, green, and red is small, and in particular, it is effective to improve color reproducibility if the half-width of the emission spectrum of green light and red light is small. For example, the half-width of the emission spectrum of the above-mentioned luminescent material (a) is preferably 50 nm or less, more preferably 40 nm or less, even more preferably 35 nm or less, and particularly preferably 30 nm or less. The half-width of the emission spectrum of the above-mentioned luminescent material (b) is preferably 60 nm or less, more preferably 50 nm or less, even more preferably 45 nm or less, and particularly preferably 40 nm or less.

[0142] The content of the luminescent material in the color-converting composition of the present invention can be selected depending on the molar absorption coefficient, fluorescence quantum yield, and absorption intensity at the excitation wavelength of the compound, as well as the thickness and transmittance of the color-converting member (color-converting sheet, etc.) to be produced. Here, the content of the luminescent material refers to the total content when the color-converting composition of the present invention contains two or more luminescent materials. The content of the luminescent material is 1.0 × 10 per 100 parts by weight of the binder resin contained in the color-converting composition of the present invention. -2 It is preferably from 1 part by weight to 5 parts by weight.

[0143] Furthermore, when the color-changing composition of the present invention contains both a luminescent material (a) that emits green light and a luminescent material (b) that emits red light, part of the green light is converted into red light, so the content w of the luminescent material (a) can be adjusted to 1 / 200 of the red light. a and the content of the luminescent material (b) w b That is, w a ≧w b In addition, the content ratio w of these light-emitting materials (a) and (b) is preferably a :w b The content w is preferably 200:1 to 3:1. a and content w b is the weight percent relative to the weight of the binder resin contained in the color converting composition of the present invention.

[0144] The color conversion composition or color conversion member of the present invention may contain other compounds as needed in addition to the organic light-emitting material satisfying the above-mentioned formula (A-1). For example, in order to increase the efficiency of energy transfer from the excitation light to the light-emitting material, the color conversion composition or color conversion member of the present invention may contain an assist dopant. Furthermore, if it is desired to add a different light-emitting color, the color conversion composition or color conversion member of the present invention may further contain the above-mentioned organic light-emitting material or a known light-emitting material such as an inorganic phosphor, a fluorescent pigment, a fluorescent dye, or a quantum dot.

[0145] <Binder resin> The color-changing composition and color-changing member of the present invention each contain a binder resin in addition to at least one organic light-emitting material described above. Materials with excellent moldability, transparency, heat resistance, and other properties are preferably used as the binder resin. Examples of binder resins include known materials such as photocurable resist materials having reactive vinyl groups, such as acrylic acid-based, methacrylic acid-based, polyvinyl cinnamate-based, and cyclic rubber-based materials, epoxy resins, silicone resins (including organopolysiloxane cured products (crosslinked products) such as silicone rubber and silicone gel), urea resins, fluororesins, polycarbonate resins, acrylic resins, urethane resins, melamine resins, polyvinyl resins, polyamide resins, phenolic resins, polyvinyl alcohol resins, cellulose resins, aliphatic ester resins, aromatic ester resins, aliphatic polyolefin resins, and aromatic polyolefin resins. Furthermore, mixtures or copolymers of these resins may also be used as the binder resin. By appropriately designing these resins, binder resins useful for the color-changing composition and color-changing material of the present invention can be obtained.

[0146] Among these resins, from the viewpoints of transparency and dispersibility of the light-emitting material, any of acrylic resins, copolymer resins containing an acrylic acid ester or methacrylic acid ester moiety, polyester resins, cycloolefin resins, epoxy resins, and silicone resins is preferable. Also, from the viewpoint of heat resistance, hydrogenated styrene-based resins, resins having a fluorene skeleton, and copolymer resins containing these resins can be suitably used.

[0147] Examples of binder resins include thermosetting resins, photocurable resins, and thermoplastic resins. Thermoplastic resins have few reactive functional groups and contain few reactive impurities such as polymerization initiators and crosslinking agents, and therefore are less likely to inhibit the luminescence of the luminescent material, making them suitable for use as binder resins. From the viewpoint of heat resistance, thermosetting resins and photocurable resins are suitable for use as binder resins.

[0148] When the binder resin is a thermoplastic resin, the glass transition temperature (Tg) of the binder resin is not particularly limited, but is preferably 30°C or higher and 180°C or lower. When the Tg of the binder resin is 30°C or higher, molecular motion of the binder resin due to heat from incident light from a light source or heat from operating the device is suppressed, thereby suppressing changes in the dispersion state of the luminescent material in the binder resin, thereby preventing deterioration of the durability of the color-converting composition and color-converting member of the present invention. Furthermore, when the Tg of the binder resin is 180°C or lower, the flexibility of the binder resin can be ensured when molded into a sheet or the like. The Tg of the binder resin is more preferably 50°C or higher and 170°C or lower, even more preferably 70°C or higher and 160°C or lower, and particularly preferably 90°C or higher and 150°C or lower. The glass transition temperature of the thermoplastic resin can be measured using a commercially available measuring device (for example, a differential scanning calorimeter manufactured by Seiko Instruments Inc. (trade name DSC6220, temperature rise rate 0.5°C / min)).

[0149] In one embodiment of the present invention, the binder resin is preferably a polymer or hydrogenation product of at least one monomer selected from the group consisting of acrylic acid esters, methacrylic acid esters, and styrene, and has a Tg of 100°C or higher. In this case, the Tg is more preferably 110°C or higher, and particularly preferably 120°C or higher. These resins can be obtained by known methods, such as copolymerizing the raw material monomers in the presence of a polymerization initiator, or by polymerizing and then converting the structure through a chemical reaction such as an addition reaction, a substitution reaction, or a redox reaction. Commercially available binder resins can also be used.

[0150] <Additives> Each of the color-converting compositions and color-converting members of the present invention may contain, as necessary, other components (e.g., additives) in addition to the at least one organic light-emitting material and binder resin described above. Examples of additives include fillers, light stabilizers, antioxidants, processing and heat stabilizers, light resistance stabilizers such as UV absorbers, dispersants and leveling agents for stabilizing coated films, scattering agents, plasticizers, crosslinking agents such as epoxy compounds, curing agents such as amines, acid anhydrides, and imidazoles, pigments, and adhesion promoters such as silane coupling agents as film surface modifiers.

[0151] Examples of fillers include fine particles such as fumed silica, glass powder, and quartz powder, as well as fine particles of titanium oxide, zirconia oxide, barium titanate, zinc oxide, and silicone. The color-changing composition and color-changing member of the present invention may each contain two or more of these fillers.

[0152] Examples of light stabilizers include, but are not limited to, tertiary amines, catechol derivatives, complexes containing at least one transition metal selected from the group consisting of nickel (Ni), scandium (Sc), vanadium (V), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), yttrium (Y), zirconium (Zr), molybdenum (Mo), silver (Ag), and lanthanoids, and salts with organic acids. These light stabilizers may be used alone or in combination.

[0153] Examples of the antioxidant include, but are not limited to, phenolic antioxidants such as 2,6-di-tert-butyl-p-cresol and 2,6-di-tert-butyl-4-ethylphenol. These antioxidants may be used alone or in combination.

[0154] Examples of processing and heat stabilizers include, but are not limited to, phosphorus-based stabilizers such as tributyl phosphite, tricyclohexyl phosphite, triethyl phosphine, and diphenylbutyl phosphine. These stabilizers may be used alone or in combination.

[0155] Examples of the light resistance stabilizer include, but are not limited to, benzotriazoles such as 2-(5-methyl-2-hydroxyphenyl)benzotriazole and 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole. These light resistance stabilizers may be used alone or in combination.

[0156] The scattering particles are preferably inorganic particles having a refractive index of 1.7 to 2.8, such as titania, zirconia, alumina, ceria, tin oxide, indium oxide, iron oxide, zinc oxide, aluminum nitride, aluminum, tin, titanium or zirconium sulfide, and titanium or zirconium hydroxide.

[0157] In the color-changing 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, as well as the size, thickness, and transmittance of the color-changing member to be produced. The content (lower limit) of these additives is 1.0 × 10 per 100 parts by weight of the binder resin. -3 It is preferable that the amount is 1.0×10 parts by weight or more. -2 It is more preferable that the amount is 1.0×10 parts by weight or more. -1 The content (upper limit) of these additives is preferably 30 parts by weight or less, more preferably 15 parts by weight or less, and particularly preferably 10 parts by weight or less, relative to 100 parts by weight of the binder resin.

[0158] <Solvent> The color-converting composition and color-converting member of the present invention may further contain a solvent in addition to the at least one organic light-emitting material and binder resin described above. A solvent that can adjust the viscosity of the resin in a fluid state and does not excessively affect the light emission and durability of the light-emitting substance is preferred. Examples of such solvents include water, 2-propanol, ethanol, toluene, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, hexane, cyclohexane, tetrahydrofuran, acetone, terpineol, Texanol, 1,2-dimethoxyethane, methyl cellosolve, ethyl cellosolve, butyl carbitol, butyl carbitol acetate, 1-methoxy-2-propanol, and propylene glycol monomethyl ether acetate. The color-converting composition and color-converting member of the present invention may each contain one of these solvents, or two or more of these solvents may be mixed together. Among these solvents, toluene, methyl ethyl ketone, methyl acetate, ethyl acetate, and tetrahydrofuran are preferably used because they leave little residual solvent after drying.

[0159] In the color conversion member of the present invention, the amount of solvent remaining in the color conversion layer of the color conversion member (the amount of solvent remaining in the color conversion layer after drying) is preferably 3.0 mass % or less, more preferably 1.0 mass % or less, and particularly preferably 0.5 mass % or less, from the viewpoint of further improving the durability of the color conversion member. The amount of solvent remaining in the color conversion layer can be measured by gas chromatography.

[0160] <Method of manufacturing color-changing composition and color-changing member> An example of a method for producing a color-changing composition according to an embodiment of the present invention is described below. In this method, the organic light-emitting material, binder resin, and, if necessary, other additives and solvents are mixed to a predetermined composition, and then the mixture is homogeneously mixed or kneaded using a stirrer / kneader to obtain a color-changing composition. 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 under vacuum or reduced pressure conditions is also preferably performed. It is also possible to premix certain components or to perform aging or other treatments. The desired solids concentration can also be achieved by removing the solvent using an evaporator.

[0161] The color conversion member of the present invention comprises the color conversion composition or a cured product thereof. The shape of the color conversion member is not particularly limited. For example, the shape of the color conversion member may be layered, particulate, fibrous, or the like. One embodiment of the color conversion member of the present invention is a color conversion sheet. The color conversion sheet has a color conversion layer that contains the color conversion composition of the present invention or a layer that contains a cured product formed by curing the color conversion composition.

[0162] The color conversion member of the present invention may have a single color conversion layer or may have multiple color conversion layers. When the color conversion member has multiple color conversion layers, the color conversion layers may be laminated directly or via an intermediate layer such as an adhesive layer. Furthermore, the color conversion member of the present invention may have a substrate layer or a barrier layer as necessary, and may have two or more of these layers.

[0163] The substrate layer of the color conversion member of the present invention is not particularly limited, and layers made of known substrates such as metals, films, glass, ceramics, and paper can be used. Among these, glass and resin films are preferably used. Resin films are preferably made of resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide, polycarbonate, polypropylene, polyimide, aramid, and silicone. To facilitate easy peeling of the sheet, the surface of the substrate layer may be previously subjected to a release treatment. Similarly, to improve adhesion between layers, the surface of the substrate layer may be previously subjected to an easy-adhesion treatment.

[0164] When the substrate layer is a film-like layer, the thickness of the substrate layer is not particularly limited, but the lower limit is preferably 12 μm or more, more preferably 38 μm or more, and the upper limit is preferably 5000 μm or less, more preferably 3000 μm or less.

[0165] Furthermore, as the substrate constituting the substrate layer, for example, members such as a barrier film, a light guide plate, a diffusion plate, a diffusion film, a prism sheet, a reflective polarizing film, a wavelength-selective reflection film, a wavelength-selective transmission film, and a wavelength-selective absorption film can be used.

[0166] The barrier layer of the color conversion member of the present invention is preferably one that suppresses the penetration of oxygen, moisture, heat, etc. into the color conversion layer. The color conversion member of the present invention may have two or more such barrier layers. For example, the color conversion member of the present invention may have a barrier layer on both sides of the color conversion layer, or may have a barrier layer on one side of the color conversion layer.

[0167] In one embodiment of the color conversion member of the present invention, the color conversion member has an oxygen barrier layer. The color conversion member of the present invention preferably has an oxygen barrier layer because it can suppress oxidative degradation of the light-emitting material in the color conversion layer due to singlet oxygen generated by a dye-sensitization mechanism or the like. Furthermore, organic light-emitting materials satisfying the above formula (A-1) exhibit significantly superior durability compared to conventional organic light-emitting materials in the absence of oxygen, making them preferable as organic light-emitting materials to be contained in the color conversion layer of the color conversion member. The reason for such superior durability is that organic light-emitting materials satisfying the above formula (A-1) have a long lifetime and can rapidly convert a triplet excited state, which is prone to react with surrounding molecules, to a singlet excited state, thereby reducing the degradation of the organic light-emitting material due to reactions between the triplet excited state and surrounding molecules.

[0168] Examples of oxygen barrier layers include layers formed of inorganic oxides such as silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, tin oxide, indium oxide, yttrium oxide, and magnesium oxide, inorganic nitrides such as silicon nitride, aluminum nitride, titanium nitride, and silicon carbonitride, metal oxide thin films or metal nitride thin films obtained by adding other elements to these, or films containing various resins such as polyvinylidene chloride, acrylic resins, silicone resins, melamine resins, urethane resins, fluorine resins, and polyvinyl alcohol resins such as saponified vinyl acetate. The oxygen barrier layer may contain two or more of these.

[0169] Representative structural examples of the color conversion member of the present invention include the structures of color conversion sheets of the first to sixth examples shown below. Note that the color conversion member of the present invention is not limited to the structural examples of the color conversion sheet shown below.

[0170] Fig. 1 is a schematic cross-sectional view showing a first example of a color conversion member according to an embodiment of the present invention. As shown in Fig. 1, the first example color conversion member 1A is a color conversion sheet having a laminated structure of a substrate layer 10 and a color conversion layer 11. This color conversion layer 11 is a layer containing the color conversion composition of the present invention and is obtained, for example, by curing the color conversion composition of the present invention. In this structural example of color conversion member 1A, color conversion layer 11 is laminated on substrate layer 10.

[0171] Fig. 2 is a schematic cross-sectional view showing a second example of a color conversion member according to an embodiment of the present invention. As shown in Fig. 2, the second example color conversion member 1B is a color conversion sheet having a laminated structure of multiple base material layers 10A, 10B and a color conversion layer 11. In this structural example of color conversion member 1B, color conversion layer 11 is sandwiched between multiple base material layers 10A, 10B.

[0172] FIG. 3 is a schematic cross-sectional view showing a third example of a color conversion member according to an embodiment of the present invention. As shown in FIG. 3, the third example of color conversion member 1C is a color conversion sheet having a laminated structure of multiple base layers 10A and 10B, a color conversion layer 11, and multiple barrier layers 12A and 12B. In this structural example of color conversion member 1C, color conversion layer 11 is sandwiched between multiple barrier layers 12A and 12B, and the laminate of color conversion layer 11 and multiple barrier layers 12A and 12B is further sandwiched between multiple base layers 10A and 10B. Each of these multiple barrier layers 12A and 12B is an oxygen barrier layer that prevents deterioration of color conversion layer 11 due to oxygen in color conversion member 1C. Note that each of these multiple barrier layers 12A and 12B is not limited to being an oxygen barrier layer and may be a layer that prevents deterioration of color conversion layer 11 due to moisture or heat.

[0173] FIG. 4 is a schematic cross-sectional view showing a fourth example of a color conversion member according to an embodiment of the present invention. As shown in FIG. 4, the fourth example color conversion member 1D is a color conversion sheet having a laminated structure in which multiple color conversion layers 11A, 11B are sandwiched between multiple base layers 10A, 10B. In this structural example of color conversion member 1D, a laminate of multiple color conversion layers 11A, 11B is formed by stacking color conversion layer 11A and color conversion layer 11B in this order on base layer 10A, and then stacking another base layer 10B on top of color conversion layer 11B. In other words, color conversion member 1D includes multiple base layers 10A, 10B and multiple color conversion layers 11A, 11B, and the multiple color conversion layers 11A, 11B are sandwiched between the multiple base layers 10A, 10B.

[0174] Fig. 5 is a schematic cross-sectional view showing a fifth example of a color conversion member according to an embodiment of the present invention. As shown in Fig. 5, the fifth example of color conversion member 1E is a color conversion sheet having a laminated structure in which an intermediate layer 13 is sandwiched between multiple color conversion layers 11A, 11B, and the laminate of these multiple color conversion layers 11A, 11B and intermediate layer 13 is sandwiched between multiple base layers 10A, 10B. In this structural example of color conversion member 1E, the laminate of multiple color conversion layers 11A, 11B and intermediate layer 13 is laminated on base layer 10A in the order color conversion layer 11A, intermediate layer 13, and color conversion layer 11B, and another base layer 10B is laminated on color conversion layer 11B. That is, the color conversion member 1E comprises a plurality of base layers 10A, 10B, a plurality of color conversion layers 11A, 11B, and an intermediate layer 13, and is sandwiched between these plurality of base layers 10A, 10B, and contains a laminated structure of color conversion layer 11B / intermediate layer 13 / color conversion layer 11A.

[0175] FIG. 6 is a schematic cross-sectional view showing a sixth example of a color conversion member according to an embodiment of the present invention. As shown in FIG. 6, the sixth example of a color conversion member 1F is a color conversion sheet having a laminated structure in which an intermediate layer 13 is sandwiched between multiple color conversion layers 11A, 11B, a laminate of these multiple color conversion layers 11A, 11B and the intermediate layer 13 is sandwiched between multiple barrier layers 12A, 12B, and a laminate of these multiple color conversion layers 11A, 11B, the intermediate layer 13, and the multiple barrier layers 12A, 12B is sandwiched between multiple base layers 10A, 10B. These multiple barrier layers 12A, 12B are formed so as to sandwich the laminate of the multiple color conversion layers 11A, 11B with the intermediate layer 13 interposed between them on both sides in the stacking direction. In this structural example of color conversion member 1F, a barrier layer 12A, a color conversion layer 11A, an intermediate layer 13, a color conversion layer 11B, and a barrier layer 12B are laminated in this order on a base layer 10A. As a result, a laminate having a layered structure of barrier layer 12B / color conversion layer 11B / intermediate layer 13 / color conversion layer 11A / barrier layer 12A is formed on this base material layer 10A. Furthermore, as shown in Figure 6, base material layer 10B is laminated on top of barrier layer 12B, which is at the top of this laminate in the stacking direction.

[0176] In each of the color conversion members 1A, 1B, 1C, 1D, 1E, and 1F shown in Figures 1 to 6, the layers of the laminated structure may be in direct contact with each other or may be laminated via an adhesive layer (not shown).

[0177] Another embodiment of the color conversion member of the present invention (an embodiment different from the color conversion sheet described above) is a color conversion substrate. The color conversion substrate, for example, comprises a plurality of color conversion layers on a substrate. Although not shown, partition walls may be formed on the color conversion substrate, and the color conversion layers may be disposed between the partition walls (in recesses) in the color conversion substrate.

[0178] Depending on the required functions, the color conversion member of the present invention may further have an auxiliary layer having a light diffusion layer, an adhesive layer, an anti-reflection function, an anti-glare function, an anti-reflection and anti-glare function, a hard coat function (abrasion resistance function), an anti-static function, an anti-fouling function, an electromagnetic wave shielding function, an infrared ray blocking function, an ultraviolet ray blocking function, a polarizing function, or a color-tuning function.

[0179] The method for producing a color conversion member according to an embodiment of the present invention is not particularly limited as long as it can mold the color conversion composition of the present invention into a desired shape. For example, a method can be used in which the color conversion composition of the present invention is applied to a substrate and dried to form a color conversion layer in the color conversion member of the present invention. When the binder resin contained in the color conversion composition of the present invention is a thermosetting resin, the color conversion layer can be formed by applying the color conversion composition to a base such as a substrate and then heat-curing the color conversion composition. When the binder resin contained in the color conversion composition of the present invention is a photocurable resin, the color conversion layer can be formed by applying the color conversion composition to a base such as a substrate and then photo-curing the color conversion composition. Other examples include a method in which the color conversion composition of the present invention is kneaded while heating and then molded using an extruder, or a method in which the color conversion composition of the present invention is placed in a mold and molded by heating, cooling, drying, or the like.

[0180] In the above-described method for producing a color conversion member, the color conversion composition can be applied using a reverse roll coater, blade coater, comma coater, slit die coater, direct gravure coater, offset gravure coater, kiss coater, natural roll coater, air knife coater, roll blade coater, two-stream coater, rod coater, wire bar coater, applicator, dip coater, curtain coater, spin coater, knife coater, etc. However, the application of the color conversion composition is not limited to these.

[0181] <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 above-described color conversion composition or color conversion member. When the light source unit of the present invention includes a color conversion composition, the arrangement of the light source and the color conversion composition is not particularly limited. The color conversion composition may be applied directly to the light source, or the color conversion composition may be applied to a substrate, such as a film or glass, that is separated from the light source. When the light source unit of the present invention includes a color conversion member, the arrangement of the light source and the color conversion member is not particularly limited. The light source and the color conversion member may be closely attached to each other, or a remote phosphor type in which the light source and the color conversion member are separated from each other may be used. The light source unit of the present invention may further include a color filter to enhance color purity, and may include an optical member, such as a prism sheet, a reflective polarizing film, or a diffusion film, to improve brightness and uniformity of the emitted light.

[0182] One embodiment of the light source unit of the present invention includes a color conversion member (color conversion sheet) having the configuration illustrated in Fig. 5, with the light source located below the plane of Fig. 5 (below base layer 10A) and a prism sheet and a reflective polarizing film laminated above the plane of Fig. 5 (above base layer 10B). A diffuser plate may be provided between the light source and the color conversion member shown in Fig. 5, and a reflector plate may be provided below the light source.

[0183] Another embodiment of the light source unit of the present invention is a configuration including a light source and a light guide plate, and a color conversion layer formed by directly applying the color conversion composition of the present invention to the light output side of the light guide plate. In a light source unit having this configuration, a light diffusion layer and a wavelength selective transmission layer may be further formed on the color conversion layer.

[0184] The light source unit of the present invention is useful for various light sources such as spatial illumination, backlighting, etc. Specifically, the light source unit of the present invention can be used for applications such as displays, lighting devices, interiors, signs, and billboards, and is particularly suitable for use in displays and lighting devices.

[0185] <Light source> The light source unit of the present invention can be equipped with any type of light source, as long as it emits light in a wavelength range that can be absorbed by the light-emitting material used in the color-converting composition or color-converting member of the present invention. In principle, any excitation light source can be used, such as a hot cathode tube, a cold cathode tube, a fluorescent light source such as inorganic electroluminescence (EL), an organic EL element light source, a light-emitting diode (LED) light source, an incandescent light source, or sunlight. Among these, from the viewpoint of color purity, an LED or an organic EL element is preferred as the light source, and an LED is more preferred.

[0186] For example, in display and lighting applications, from the viewpoint of enhancing the color purity of blue light, LEDs or organic EL elements having a maximum emission wavelength in the range of 400 nm to 500 nm are preferred light sources. Furthermore, as the light source, blue LEDs having a maximum emission wavelength in the range of 430 nm to 480 nm are more preferred, and blue LEDs having a maximum emission wavelength in the range of 445 nm to 470 nm are particularly preferred.

[0187] The light source may have one emission peak or two or more emission peaks, but in order to improve color purity, it is preferable to have one emission peak. It is also possible to use a combination of multiple light sources with different emission peaks.

[0188] <Displays, lighting equipment> A display according to an embodiment of the present invention includes at least a light source unit having a light source and a color-converting composition or a color-converting member as described above. For example, in a display such as a liquid crystal display, the light source unit described above is used as a backlight unit.

[0189] Furthermore, an illumination device according to an embodiment of the present invention includes at least a light source unit having a light source and a color conversion composition or a color conversion member as described above. For example, this illumination device is configured to emit white light by combining a blue LED light source as the light source unit with a color conversion composition or a color conversion member that converts blue light from the blue LED light source into light with a longer wavelength. [Example]

[0190] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples. First, the evaluation methods and materials such as light-emitting materials in the examples and comparative examples will be described.

[0191] <Measurement of Emission Spectrum> In measuring the emission spectra, the fluorescent emission spectrum and phosphorescent emission spectrum of the luminescent material dissolved in a solution (hereinafter referred to as the luminescent material in a solution state), and the fluorescent emission spectrum and phosphorescent emission spectrum of the luminescent material in the binder resin contained in the color conversion member (hereinafter referred to as the luminescent material in the color conversion member) were measured.

[0192] Specifically, when measuring the fluorescence emission spectrum and phosphorescence emission spectrum of a light-emitting material in a solution state, the compound that is the target organic light-emitting material is dissolved in toluene at 1 × 10 -5The compound was dissolved at a concentration of 1000 mol / L to prepare a sample of the compound contained in a dilute toluene solution (hereinafter referred to as a solution sample). After nitrogen bubbling through the prepared solution sample, the fluorescence emission spectrum and phosphorescence emission spectrum of the solution sample were measured using a fluorescence spectrophotometer (Fluoromax4, manufactured by Horiba, Ltd.). Furthermore, when measuring the fluorescence emission spectrum and phosphorescence emission spectrum of the light-emitting material in the color conversion member, a color conversion composition containing the target organic light-emitting material compound was molded into a film to prepare a small sample. The fluorescence emission spectrum and phosphorescence emission spectrum of the small sample were measured using a fluorescence spectrophotometer (Fluoromax4, manufactured by Horiba, Ltd.). The fluorescence emission spectrum was measured at room temperature (300 K), and the phosphorescence emission spectrum was measured at 77 K.

[0193] <Measurement of luminescence quantum yield> In the measurement of the luminescence quantum yield, the luminescence quantum yield of the luminescent material in a solution state and the luminescence quantum yield of the luminescent material in the color conversion member were measured.

[0194] Specifically, when measuring the luminescence quantum yield of a luminescent material in a solution state, the compound that is the target organic luminescent material is dissolved in toluene at 1 × 10 -5 A solution sample was prepared by dissolving the compound at a concentration of 1000 mol / L, and after nitrogen bubbling through the prepared solution sample, the luminescence quantum yield of the solution sample was measured using an absolute PL quantum yield measurement device (Quantaurus-QY, manufactured by Hamamatsu Photonics) when excited with excitation light having a wavelength of 460 nm. In addition, when measuring the luminescence quantum yield of the luminescent material in the color conversion member, a color conversion composition containing a compound that is the target organic luminescent material was formed into a film to prepare a small piece sample, and the luminescence quantum yield of the small piece sample was measured using an absolute PL quantum yield measurement device (Quantaurus-QY, manufactured by Hamamatsu Photonics) when excited with excitation light having a wavelength of 460 nm.

[0195] <Fluorescence lifetime measurement method and calculation method of reverse intersystem crossing rate constant> In the fluorescence lifetime measurement, the fluorescence lifetime of the luminescent material in the solution state and the fluorescence lifetime of the luminescent material in the color conversion member were measured, and in the calculation of the reverse intersystem crossing rate constant, the reverse intersystem crossing rate constants of the luminescent material in the solution state and the luminescent material in the color conversion member were calculated.

[0196] In detail, when measuring the fluorescence lifetime of a light-emitting material in a solution state, the compound that is the target organic light-emitting material is dissolved in toluene at 1 × 10 -5 A solution sample was prepared by dissolving the compound at a concentration of 1000 mol / L. After bubbling nitrogen through the prepared solution sample, the fluorescence lifetime of the solution sample was measured using a compact fluorescence lifetime measurement device (Quantaurus-Tau, manufactured by Hamamatsu Photonics). The fast and slow components of the fluorescence lifetime of the solution sample were observed at the maximum emission wavelength measured at an excitation wavelength of 470 nm, and the reverse intersystem crossing rate constant k in the solution sample was calculated based on the method described in Angew. Chem. Int. Ed. 2020, 59.17442. RISC was calculated. In addition, when measuring the fluorescence lifetime of the light-emitting material in the color conversion member, a color conversion composition containing a compound that is the target organic light-emitting material was formed into a film to prepare a small sample, and the fluorescence lifetime of the small sample was measured using a small fluorescence lifetime measurement device (Quantaurus-Tau, manufactured by Hamamatsu Photonics KK). The fast and slow components of the fluorescence lifetime of the small sample were observed at the maximum emission wavelength measured at an excitation wavelength of 470 nm, and the reverse intersystem crossing rate constant k' in the small sample was calculated based on the same method as above. RISC was calculated.

[0197] <Calculation method for the activation energy of reverse intersystem crossing> In calculating the activation energy of reverse intersystem crossing, the activation energy E RISC and the activation energy E' of reverse intersystem crossing in the luminescent material in the color conversion member. RISC and was calculated.

[0198] In detail, the activation energy E of reverse intersystem crossing in the luminescent material in solution RISCWhen calculating the reverse intersystem crossing rate constant k at three or more temperatures (e.g., -50°C, 0°C, 50°C) in the temperature range of -50°C to 50°C, the method described above is used. RISC After calculating, using the above-mentioned formula (A-3), lnk in formula (A-3) RISC T 0.5 With 1 / T as the horizontal axis and 1 / T as the vertical axis, the lnk RISC T 0.5 The values ​​of were plotted. Then, the slope of the approximate line based on these plotted values ​​was referenced, and the activation energy E of the desired reverse intersystem crossing was calculated. RISC In the formula (A-3), lnA is the value determined from the intersection of the approximation line and the vertical axis at 1 / T=0, as described above.

[0199]

number

[0200] Similarly, the activation energy E' of reverse intersystem crossing in the luminescent material in the color conversion member RISC When calculating the reverse intersystem crossing rate constant k' at three or more temperatures (e.g., -50°C, 0°C, 50°C) in the temperature range of -50°C to 50°C, the method described above is used. RISC After calculating, using the above-mentioned formula (A-8), lnk' in formula (A-8) RISC T' 0.5 With 1 / T' as the vertical axis and 1 / T' as the horizontal axis, lnk' at each temperature T' RISC T' 0.5 The values ​​of , and , were plotted. Then, the slope of the approximate line based on these plotted values ​​was referenced, and the activation energy E' of the desired reverse intersystem crossing was calculated. RISC In equation (A-8), lnA' is the value determined from the intersection of the approximation line and the vertical axis at 1 / T'=0, as described above.

[0201]

number

[0202] <Measurement of chromaticity change> To measure the chromaticity change, a light-emitting device equipped with a blue LED (USHIO EPITEX; model number SMBB450H-1100, peak emission wavelength: 450 nm) was first turned on so that the intensity of the emitted blue light was 8000 nits. The intensity of the blue light was measured using a spectroradiometer (Konica Minolta CS-1000).

[0203] Next, the color conversion member prepared in each of the Examples and Comparative Examples described below was placed between the blue LED of the light-emitting device and the spectroradiometer, and the blue light from the blue LED was color-converted by the color conversion member. The initial chromaticity y value of the color-converted transmitted light in the xy coordinate system was measured using the spectroradiometer. The distance between the color conversion member and the blue LED was 3 cm.

[0204] Thereafter, blue light was irradiated from the blue LED onto the color conversion member for 200 hours, and the blue light irradiated successively and continuously for 200 hours was color converted by the color conversion member kept at 75°C or 30°C. The chromaticity y of the transmitted light after this 200-hour continuous color conversion was measured using the spectroradiometer, and the absolute value of the change in chromaticity y from the initial value (Δy(75°C), Δy(30°C)) was calculated.

[0205] <Light durability evaluation> In the light durability evaluation, for each of the examples and comparative examples described below, a light-emitting device equipped with the prepared color conversion member and a blue LED (manufactured by USHIO EPITEX; model number SMBB450H-1100, peak emission wavelength: 450 nm) was run through it. A current of 500 mA was passed through the device to lighten the blue LED, and the initial peak emission intensity was measured using a spectroradiometer (CS-1000, manufactured by Konica Minolta). The distance between the color conversion member and the blue LED in this light-emitting device was 3 cm. The color conversion member was then continuously irradiated with light from the blue LED in an environment of 75°C, and the time until the peak emission intensity decreased by 5% was observed to evaluate the light durability of the color conversion member.

[0206] <Organic light-emitting materials> In the following examples and comparative examples, compounds D-1 to D-3 were used as the organic light-emitting material contained in the color conversion member. Compounds D-1 to D-3 are the compounds shown below.

[0207] [ka]

[0208] <Scattering agent> In the following examples and comparative examples, titanium dioxide particles "JR-301" (manufactured by Teika Co., Ltd.) were used as the scattering agent.

[0209] Example 1 In Example 1, PMMA resin "BR-85" (manufactured by Mitsubishi Chemical Corporation) was used as the binder resin. 100 parts by weight of this binder resin were mixed with 0.10 parts by weight of Compound D-1 as the luminescent material, 3 parts by weight of JR-301 as the scattering agent, and 300 parts by weight of ethyl acetate as the solvent. The mixture was then stirred and degassed at 1000 rpm for 20 minutes using a planetary stirring and degassing device "Mazerustar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.). This yielded a resin composition for producing a color conversion layer (the color conversion composition of Example 1).

[0210] Next, the resin composition for producing the color conversion layer obtained above was applied onto "Cerapeel" BLK (manufactured by Toray Advanced Film Co., Ltd.) using a film applicator, and then heated and dried at 120°C for 20 minutes, thereby forming a color conversion layer with an average film thickness of 20 μm.

[0211] Next, a hydrochloric acid solution prepared by mixing 0.1N hydrochloric acid (4g) and water (5g) was slowly added dropwise to a mixture of tetraethyl orthosilicate (1.2g), 2-propanol (0.5g), and methanol (0.5g). Then, a polyvinyl alcohol resin (0.4g) with a saponification degree of 98 mol% or more was mixed into the mixture and stirred. This produced a resin solution for producing an oxygen barrier layer.

[0212] This resin liquid for producing an oxygen barrier layer was applied by bar coating onto an alumina-deposited polyethylene terephthalate film "Barrierox" (registered trademark) 1011HG (manufactured by Toray Industries, Inc., thickness 12 μm), and then dried at 150°C for 1 minute. This formed a coating layer of the resin liquid. Furthermore, a coating layer with an average thickness of approximately 1 μm was formed on this coating layer, thereby producing an oxygen barrier laminate film, an example of a barrier layer. In Example 1, two sheets of this oxygen barrier laminate film were prepared.

[0213] Next, a thermosetting adhesive layer was formed by coating on the polyvinyl alcohol resin layer of one of the oxygen barrier laminate films, and the color conversion layer was laminated on top of that.The "Cerapeel" BLK was then peeled off from the color conversion layer.

[0214] Finally, a thermosetting adhesive layer was formed by coating on the polyvinyl alcohol resin layer of another oxygen barrier laminate film, and the resulting thermosetting adhesive layer was laminated on the color conversion layer after peeling off the "Cerapeel" BLK. This produced a sheet-like color conversion member (e.g., the color conversion sheet illustrated in Figure 3). The average film thickness of all thermosetting adhesive layers included in this color conversion member was 0.50 μm. Note that the thermosetting adhesive layer is not shown in Figure 3.

[0215] The compound D-1, which is the luminescent material of Example 1, was evaluated and showed high color purity green fluorescent light in a dilute toluene solution, with a peak wavelength of 518 nm and a half-width of 17 nm. Furthermore, the compound D-1 in a dilute toluene solution (a luminescent material in a solution state) was evaluated and found to have a peak wavelength of 518 nm and a half-width of 17 nm. F -E P The value of E is 0.018 eV. RISC The value of k is 0.018 eV / mol. RISC (30℃) is 0.70×10 -5 It was.

[0216] In Example 1, as described above, a sheet-like color conversion member containing compound D-1 as a light-emitting material was prepared and evaluated. As a result, compound D-1 exhibited high color purity green fluorescent light emission in the prepared sheet-like color conversion member, with a peak wavelength of 518 nm and a half-value width of 23 nm. Furthermore, as a result of evaluating compound D-1 in the color conversion member, E' F -E' P The value of E' is 0.018 eV. RISC The value of k' is 0.018 eV / mol. RISC (30℃) is 1.3×10 -5 Furthermore, using the color conversion member of Example 1, the color conversion was performed for 200 hours continuously by irradiating blue light as described above in an environment maintained at 30°C, and the Δy(30°C) was measured when the color conversion was performed for 200 hours continuously by irradiating blue light as described above in an environment maintained at 70°C. As a result, the value of Δy(75°C) / Δy(30°C) was 0.60.

[0217] Furthermore, when the color conversion member of Example 1 was continuously irradiated with light from a blue LED in an environment of 50°C, the time until the emission peak intensity decreased by 5% (light durability) was approximately 500 hours. Example 1 showed approximately twice the improvement in light durability compared to Comparative Example 1 described below. The luminescent material and evaluation results of Example 1 are as shown in Table 1 described below. In Table 1, the "Dilute Solution" column shows the evaluation results of the luminescent material in solution state. The "Film" column shows the evaluation results of the luminescent material in the color conversion member.

[0218] Comparative Example 1 In Comparative Example 1, the luminescent material was changed to Compound D-2, and the amount of the luminescent material mixed was adjusted to be the same as that of Compound D-1 in Example 1, except that a sheet-like color conversion member was produced and evaluated in the same manner as in Example 1. The luminescent material and evaluation results of Comparative Example 1 are shown in Table 1.

[0219] Comparative Example 2 In Comparative Example 2, the luminescent material was changed to Compound D-3, and the amount of the luminescent material mixed was adjusted to be the same as that of Compound D-1 in Example 1. A sheet-like color conversion member was produced and evaluated in the same manner as in Example 1. The evaluation results showed that Compound D-3 in Comparative Example 2 did not exhibit phosphorescence either in solution or in the color conversion member. The luminescent material and evaluation results for Comparative Example 2 are shown in Table 1.

[0220] [Table 1] [Industrial Applicability]

[0221] As described above, the color-converting composition, color-converting member, and light source unit, display, and lighting device each including the color-converting composition, color-converting member, according to the present invention are suitable for achieving both high color purity and high durability. [Explanation of symbols]

[0222] 1A, 1B, 1C, 1D, 1E, 1F Color conversion material 10, 10A, 10B base material layer 11, 11A, 11B color conversion layer 12A, 12B Barrier layer 13 Middle class

Claims

1. A color-converting composition comprising at least one organic light-emitting material and a binder resin, Satisfies the following formula (A-1): A color-changing composition comprising: [Equation 1] (In formula (A-1), E F represents the energy at the peak wavelength of the fluorescence emission spectrum of the at least one organic light-emitting material in a dilute toluene solution. P represents the energy at the peak wavelength of the phosphorescent emission spectrum of the at least one organic light-emitting material in a dilute toluene solution.

2. Satisfies the following formula (A-2):

2. The color-changing composition of claim 1. [Equation 2] (In formula (A-2), E RISC represents the activation energy of reverse intersystem crossing of the at least one organic light-emitting material contained in a dilute toluene solution in the temperature range of −50° C. to 50° C. RISC is a value that can be calculated using the following formula (A-3): [Equation 3] (In formula (A-3), ln represents the natural logarithm. k RISC represents the reverse intersystem crossing rate constant of the at least one organic light-emitting material contained in a dilute toluene solution at each temperature. T represents the temperature [K] of the dilute toluene solution. Ｂ represents the Boltzmann constant. RISC is the reverse intersystem crossing rate constant k at each temperature T RISC After calculating, use equation (A-3) and change the vertical axis to lnk RISC T 0.5 The horizontal axis is 1 / T, and the lnk RISC T 0.5 The values ​​of the plotted lnk RISC T 0.5 lnA can be determined by looking up the slope of an approximate line based on the values ​​of 1 / T. lnA can be determined from the intersection of the approximate line and the vertical axis at 1 / T=0.

3. Satisfies the following formula (A-4):

2. The color-changing composition of claim 1. [Equation 4] (In formula (A-4), k RISC (30°C) represents the rate constant of reverse intersystem crossing of the at least one organic light-emitting material in a dilute toluene solution at 30°C.

4. Satisfies the following formula (A-5):

2. The color-changing composition of claim 1. [Equation 5] (In formula (A-5), Δy is the absolute value of the amount of change in chromaticity y from the initial value in the xy coordinates of the color-converted transmitted light when continuous light irradiation is performed for 200 hours using light from a blue LED having a peak wavelength in the range of 450 nm±3 nm and an intensity of 8000 nits. Δy(75°C) represents the Δy when the continuous light irradiation is performed while keeping the temperature at 75°C. Δy(30°C) represents the Δy when the continuous light irradiation is performed while keeping the temperature at 30°C.)

5. the peak wavelength of the fluorescence emission spectrum of the at least one organic light-emitting material in a dilute toluene solution is in a wavelength range of 500 nm or more; 2. The color-changing composition of claim 1.

6. A color conversion member comprising at least one organic light-emitting material and a binder resin, Satisfies the following formula (A-1): A color conversion member characterized by: [Equation 6] (In formula (A-1), E F represents the energy at the peak wavelength of the fluorescence emission spectrum of the at least one organic light-emitting material in a dilute toluene solution. P represents the energy at the peak wavelength of the phosphorescent emission spectrum of the at least one organic light-emitting material in a dilute toluene solution.

7. Satisfies the following formula (A-6): The color conversion member according to claim 6 . [Equation 7] (In formula (A-6), E' F E' represents the energy at the peak wavelength of the fluorescence emission spectrum of the color conversion member. P indicates the energy at the peak wavelength of the phosphorescent emission spectrum of the color conversion member.

8. Satisfies the following formula (A-7): The color conversion member according to claim 6 . [Equation 8] (In formula (A-7), E' RISC represents the activation energy of reverse intersystem crossing of the at least one organic light-emitting material contained in the color conversion member in the temperature range of −50° C. to 50° C. RISC is a value that can be calculated using the following formula (A-8): [Equation 9] (In formula (A-8), ln represents the natural logarithm. k' RISC represents the rate constant of reverse intersystem crossing of the at least one organic light-emitting material contained in the color conversion member at each temperature. T' represents the temperature [K] of the color conversion member. k Ｂ represents the Boltzmann constant. RISC is the reverse intersystem crossing rate constant k' at each temperature T' RISC After calculating, use equation (A-8) to set the vertical axis to lnk' RISC T' 0.5 The horizontal axis is 1 / T', and the lnk' at each temperature T' is RISC T' 0.5 The values ​​of the plotted lnk' are plotted. RISC T' 0.5 lnA' can be found by looking up the slope of an approximate line based on the values ​​of 1 / T'. lnA' can be found from the intersection of the approximate line and the vertical axis at 1 / T' = 0.

9. Satisfies the following formula (A-9): The color conversion member according to claim 6 . [Equation 10] (In formula (A-9), k' RISC (30°C) represents the rate constant of reverse intersystem crossing of the at least one organic light-emitting material contained in the color conversion member at 30°C.

10. Satisfies the following formula (A-5): The color conversion member according to claim 6 . [0011] (In formula (A-5), Δy is the absolute value of the amount of change in chromaticity y from the initial value in the xy coordinates of the color-converted transmitted light when continuous light irradiation is performed for 200 hours using light from a blue LED having a peak wavelength in the range of 450 nm±3 nm and an intensity of 8000 nits. Δy(75°C) represents the Δy when the continuous light irradiation is performed while keeping the temperature at 75°C. Δy(30°C) represents the Δy when the continuous light irradiation is performed while keeping the temperature at 30°C.)

11. the peak wavelength of the fluorescence emission spectrum of the at least one organic light-emitting material in a dilute toluene solution is in a wavelength range of 500 nm or more; The color conversion member according to claim 6 .

12. having an oxygen barrier layer, The color conversion member according to claim 6 .

13. A light source and The color conversion member according to claim 6 ; A light source unit comprising:

14. A light source unit according to claim 13, A display characterized by:

15. A light source unit according to claim 13, A lighting device characterized by:

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