Color conversion sheet, light source unit, display and lighting device containing the same

Abstract

The present invention provides a color conversion sheet having high in-plane uniformity and durability in a color conversion sheet for a display or a lighting device, etc., a light source unit, a display, and a lighting device including the same. The color conversion sheet is a color conversion sheet that converts incident light into light having a wavelength different from that of the incident light. The color conversion sheet contains at least a color conversion layer (A), a color conversion layer (B), a resin layer, and a substrate. The color conversion layer (A) contains a luminescent material (a) that emits light having a peak wavelength observed in a region of 500 nm or more and less than 580 nm. The color conversion layer (B) contains a luminescent material (b) that emits light having a peak wavelength observed in a region of 580 nm or more and 750 nm or less. The haze value of the color conversion sheet is 20% or more and 90% or less. When the refractive index of the color conversion layer (A) is set to n A1 , the refractive index of the color conversion layer (B) is set to n A2 , and the refractive index of the resin layer is set to n B , n A1 > n B and n A2 > n B .

Description

Technical Field

[0001] The invention relates to a color conversion sheet and a light source unit, a display and a lighting device containing the same. Background Art

[0002] Active research is being conducted on the application of multicolor technology using color conversion to liquid crystal displays or organic electroluminescence (EL) displays, lighting, etc. Color conversion means converting the light emitted from a light source into light with a longer wavelength, such as converting blue light into green or red light.

[0003] By making the composition with the color conversion function into a sheet and combining it with a blue light source, the three primary colors of blue, green and red can be extracted from the blue light source, thereby obtaining white light. The white light source formed by combining the blue light source with the sheet with the color conversion function (hereinafter referred to as the "color conversion sheet") is used as a light source unit and combined with a liquid crystal drive part and a color filter, thereby making a full-color display. In addition, the white light source can also be directly applied to light emitting diode (LED) lighting, etc.

[0004] As a problem of liquid crystal displays using a color conversion method, there is a deviation in the color sense emitted from the light source in the light-emitting area of ​​the backlight device. As a method for solving the above problem, a technology for increasing the content of color conversion material per unit area in the portion of the color conversion sheet located at the peripheral portion of the display has also been proposed (for example, see Patent Document 1).

[0005] In addition, in order to prevent the degradation of organic light-emitting materials and improve durability, a technology of adding a light stabilizer is also disclosed (for example, see Patent Document 2).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Laid-Open No. 2018-195583

[0009] Patent Document 2: Japanese Patent Application Publication No. 2011-241160 Summary of the invention

[0010] Problems to be solved by the invention

[0011] However, in Patent Document 1, the brightness decreases due to the aggregation of the phosphor due to the increase in the content of the color conversion material, and the technology for maintaining sufficient durability is insufficient. In addition, in Patent Document 2, sufficient in-plane uniformity cannot be ensured, and the balance between in-plane uniformity and durability is insufficient.

[0012] An object of the present invention is to provide a color conversion sheet used in a display, a lighting device, etc., which has high in-plane uniformity and durability.

[0013] Technical means of solving problems

[0014] In order to solve the above-mentioned problems and achieve the purpose, the color conversion sheet of the present invention is a color conversion sheet that converts incident light into light with a wavelength different from that of the incident light, the color conversion sheet at least comprising a color conversion layer (A), a color conversion layer (B), a resin layer and a substrate, the color conversion layer (A) comprising a luminescent material (a) exhibiting luminescence with a peak wavelength observed in a region of 500 nm or more and less than 580 nm, the color conversion layer (B) comprising a luminescent material (b) exhibiting luminescence with a peak wavelength observed in a region of 580 nm or more and 750 nm or less, the haze value of the color conversion sheet being 20% ​​or more and 90% or less, and when the refractive index of the color conversion layer (A) is set to n A1 , let the refractive index of the color conversion layer (B) be n A2 , and the refractive index of the resin layer is set to n B When n A1 、n A2 and n B Satisfies the following relationship (1) or (2):

[0015] (1)n A1 >n B And n A2 >n B

[0016] (2)n A1 <n B And n A2 <n B .

[0017] In addition, another embodiment of the present invention is a color conversion sheet, which is a color conversion sheet that converts incident light into light with a wavelength different from that of the incident light, and the color conversion sheet at least includes a color conversion layer (A), a color conversion layer (B), a resin layer and a substrate.

[0018] The color conversion layer (A) contains a luminescent material (a) that emits light with a peak wavelength observed in a region of 500 nm to less than 580 nm, the color conversion layer (B) contains a luminescent material (b) that emits light with a peak wavelength observed in a region of 580 nm to 750 nm, the color conversion sheet has a haze value of 20% to 90%, one or both of the color conversion layer (A) and the color conversion layer (B) contain scattering particles, and when the haze value of the color conversion layer (A) is set to H A The haze of the color conversion layer (B) is set to H B When |H A -H B |≥20%.

[0019] In addition, another embodiment of the present invention is a color conversion sheet, which is a color conversion sheet that converts incident light into light with a wavelength different from that of the incident light, and the color conversion sheet at least includes a color conversion layer, a resin layer and a substrate in this order.

[0020] The color conversion layer contains a luminescent material (a) that emits light with a peak wavelength observed in a region of 500 nm to less than 580 nm and a luminescent material (b) that emits light with a peak wavelength observed in a region of 580 nm to less than 750 nm, and the color conversion sheet has a haze value of 20% to 90%.

[0021] When the refractive index of the color conversion layer is set to n A , the refractive index of the resin layer is set to n B , and the refractive index of the substrate is set to n C When n A >n B And n B <n C .

[0022] Effects of the Invention

[0023] The color conversion sheet of the present invention has the effect of high in-plane uniformity and durability. The light source unit, display and lighting device of the present invention use such a color conversion sheet, and thus have the effect of high in-plane uniformity and durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic cross-sectional view showing an example of the color conversion sheet of the present invention.

[0025] Figure 2 This is a schematic cross-sectional view showing an example of the color conversion sheet of the present invention.

[0026] Figure 3This is a schematic cross-sectional view showing an example of the color conversion sheet of the present invention.

[0027] Figure 4 This is a schematic cross-sectional view showing an example of the color conversion sheet of the present invention.

[0028] Figure 5 This is a schematic cross-sectional view showing an example of the light source unit of the present invention.

[0029] Explanation of symbols

[0030] 1: Base material layer

[0031] 2: Color transformation layer (B)

[0032] 3: Resin layer

[0033] 4: Color transformation layer (A)

[0034] 5: Color changing film

[0035] 6: Barrier layer

[0036] 7: Color transformation layer

[0037] 8: Substrate

[0038] 9: Reflection layer

[0039] 10: Light source

[0040] 11: Diffuser plate

[0041] 12: Prism

[0042] 13: Polarized reflective film

[0043] 14: Light source unit DETAILED DESCRIPTION

[0044] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments and can be implemented with various modifications depending on the purpose and application.

[0045] The color conversion sheet of the present invention is a color conversion sheet that converts incident light from a light source or the like into light having a wavelength different from that of the incident light, and the color conversion sheet comprises at least a color conversion layer (A), a color conversion layer (B), a resin layer, and a substrate. The color conversion layer (A) is a layer containing a luminescent material (a) that emits light with a peak wavelength observed in a region of 500 nm to less than 580 nm, and the color conversion layer (B) is a layer containing a luminescent material (b) that emits light with a peak wavelength observed in a region of 580 nm to less than 750 nm.

[0046] The peak wavelength of the luminescence of the luminescent material (e.g., the luminescent material (a) and the luminescent material (b)) can be confirmed by fluorescence spectrometry of its solution. The solvent used for the fluorescence spectrometry is not particularly limited, and preferably, toluene, dichloromethane, tetrahydrofuran or the like can be used. As long as there is no problem with the solubility of the luminescent material, it is more preferred to use toluene as the solvent.

[0047] Hereinafter, light emission with a peak wavelength observed in a region of 500 nm to less than 580 nm is referred to as “green light emission”, and light emission with a peak wavelength observed in a region of 580 nm to 750 nm is referred to as “red light emission”.

[0048] In order to make the luminescent material emit light, the light irradiated to the luminescent material is called excitation light. Generally speaking, the greater the energy of the excitation light, the easier it is to cause the decomposition of the material. The energy of the excitation light in the range of wavelengths above 400nm and below 500nm is small, and does not cause the decomposition of the luminescent material in the color conversion composition, so that luminescence with good color purity can be obtained. As the incident light from a light source or the like that can be incident on the color conversion sheet, the excitation light can be used.

[0049] A portion of the excitation light (hereinafter referred to as "blue light") in the range of wavelengths of 400 nm to 500 nm is transmitted through the color conversion sheet without being converted into light of a different wavelength, so that it can be used as blue light emission itself. In addition, the color conversion sheet of the present invention contains a luminescent material (a) that emits green light and a luminescent material (b) that emits red light. Therefore, when a blue LED light source with a sharp shape of the luminescent peak is combined with the color conversion sheet of the present invention to form a white light source, a white light having a sharp-shaped luminescent spectrum and good color purity in each of the blue, green, and red colors can be obtained. As a result, a display using the white light source can efficiently form a color gamut with brighter colors and a larger color range. In addition, in the lighting device, compared with the white LED that is a combination of a blue LED and a yellow phosphor, which has become the current mainstream, the luminescent characteristics in the green region and the red region are improved, so a preferred white light source with improved color can be obtained.

[0050] In order to expand the color gamut of a display and improve color reproducibility, it is preferable that the overlap of the emission spectra of the respective colors of blue, green, and red is small.

[0051] For example, when blue light with a wavelength of 400 nm or more and 500 nm or less is used as excitation light, by using a luminescent material (a) that emits light with a peak wavelength observed in a region above 500 nm and converting the blue light into green light, the overlap of the luminescent spectrum of the excitation light and the green light becomes smaller, and the color reproducibility is improved. On the basis of further increasing the above effect, the lower limit of the peak wavelength of the luminescent material (a) is more preferably 510 nm or more, further preferably 515 nm or more, and particularly preferably 520 nm or more.

[0052] In addition, in order to reduce the overlap of the emission spectra of green light and red light, it is preferred to use a luminescent material (a) that emits light with a peak wavelength observed in a region below 580 nm. On the basis of further increasing the above effect, the upper limit of the peak wavelength of the luminescent material (a) is more preferably below 550 nm, further preferably below 540 nm, and particularly preferably below 535 nm.

[0053] Furthermore, by using a luminescent material (a) that exhibits a peak wavelength observed in a region of 500 nm or more and less than 580 nm in green luminescence, and using a luminescent material (b) that exhibits a peak wavelength observed in a region of 580 nm or more in red luminescence, the overlap of the luminescence spectra of green light and red light becomes smaller, and color reproducibility is improved. On the basis of further increasing the above effect, the lower limit of the peak wavelength of the luminescent material (b) is more preferably 610 nm or more, further preferably 620 nm or more, and particularly preferably 630 nm or more.

[0054] The upper limit of the peak wavelength of the luminescent material (b) can be near the upper limit of the visible light range, that is, 750 nm or less. When it is 700 nm or less, visual acuity increases, which is more preferred. In order to further increase the above effect, the upper limit of the peak wavelength of the luminescent material (b) is preferably 680 nm or less, and particularly preferably 660 nm or less.

[0055] That is, when blue light with a wavelength of 400 nm to 500 nm is used as excitation light, the peak wavelength of the luminescent material (a) is preferably observed in a region of 500 nm to less than 580 nm, more preferably 510 nm to 550 nm, further preferably 515 nm to 540 nm, and particularly preferably 520 nm to 535 nm. In addition, the peak wavelength of the luminescent material (b) is preferably observed in a region of 580 nm to 750 nm, more preferably 610 nm to 700 nm, further preferably 620 nm to 680 nm, and particularly preferably 630 nm to 660 nm.

[0056] In order to reduce the overlap of the emission spectrum and improve the color purity and color reproducibility, it is preferred that the half-value width of the emission spectrum of each color of blue, green, and red is small. In particular, a small half-value width of the emission spectrum of green light and red light is effective for improving color purity or color reproducibility.

[0057] As described above, the color conversion sheet of the present invention has at least two color conversion layers, a color conversion layer (A) containing a luminescent material (a) and a color conversion layer (B) containing a luminescent material (b). By containing the luminescent material (a) and the luminescent material (b) in different layers, the interaction between the materials is suppressed, and compared with the case where the luminescent material (a) and the luminescent material (b) are dispersed in the same layer, it can show luminescence with higher color purity, so it is preferred. In addition, the luminescent material (a) and the luminescent material (b) emit light independently in each layer, so it becomes easy to adjust the peak wavelength or luminescent intensity of green and red light emission.

[0058] Typical structural examples of the color conversion sheet of the present invention include: Figure 1 . Figure 1 This is a schematic cross-sectional view showing an example of the color conversion sheet of the present invention. Figure 1 The color conversion sheet 5 shown includes a base layer 1, and the base layer 1 contains a color conversion layer (B) 2, a resin layer 3, and a color conversion layer (A) 4 in this order. Figure 2 Another example of the color conversion sheet of the present invention is shown in FIG. Figure 2 In the color conversion sheet shown, the base material layer 1 is further arranged on the color conversion layer (A) 4 , and the color conversion layer (B) 2 , the resin layer 3 , and the color conversion layer (A) 4 are sandwiched by the base material layer 1 .

[0059] The above-described configuration examples are merely illustrative, and the specific configuration of the color conversion sheet of the present embodiment is not limited thereto. Configurations obtained by appropriately adding changes to matters derived from the following description are also included in the scope of the present invention.

[0060] <Haze value of color conversion sheet>

[0061] In the present invention, the haze value of the color conversion sheet is 20% or more and 90% or less. By being within the above range, the scattering of light in the color conversion layer increases, so the light conversion efficiency of the luminescent material is improved, and the in-plane uniformity and durability of the color conversion sheet can be taken into account. The haze value is more preferably 50% or more and 75% or less. The haze value can be measured according to American Society for Testing Material (ASTM) D 1003 (2013).

[0062] The method for making the haze value of the color conversion sheet of the present invention fall within the above range is not particularly limited, and examples thereof include a method of making the color conversion layer contain scattering particles, a method of providing a light scattering layer separately from the color conversion layer, and a method of increasing the surface roughness of the substrate constituting the color conversion sheet. Among them, a method of making the color conversion layer contain scattering particles is more preferred.

[0063] In an embodiment of the color conversion sheet of the present invention, when scattering particles are contained in one or both of the color conversion layer (A) and the color conversion layer (B), the haze of the color conversion layer (A) is set to H A The haze of the color conversion layer (B) is set to H B When |H A -H B |≥20%. The absolute value of the haze difference between the color conversion layer (A) and the color conversion layer (B) has a great influence on the color gamut and brightness of the resulting display. A and H B When the difference is within the above range, a color conversion sheet with a high color gamut and high brightness described later can be obtained.

[0064] <Scattering Particles>

[0065] Examples of the scattering particles for controlling the haze include particles of organic matter and / or inorganic matter.

[0066] Specifically, particles including glass, titanium dioxide, silicon dioxide, aluminum oxide, silicone resin, zirconium oxide, cerium oxide, aluminum nitride, silicon carbide, silicon nitride, barium titanate, acrylic resin, etc. can be cited. These can be used alone or in combination of two or more. From the perspective of easy availability, particles selected from silica particles, aluminum oxide particles, titanium dioxide particles, zirconium oxide particles, acrylic resin particles, silicone resin particles, etc. are preferred. From the perspective of dispersibility in the binder resin in the color conversion layer, titanium dioxide particles are more preferred.

[0067] In addition, from the viewpoint of improving brightness, the scattering particles preferably contain particles selected from alumina particles, silica particles, and silicone resin particles. When the refractive index of the scattering particles contained in the color conversion layer (A) is n A1 , and the refractive index of the color conversion layer (B) is set to n A2 , the refractive index of the scattering particles contained in the color conversion layer (A) is set to n D1 , and the refractive index of the scattering particles contained in the color conversion layer (B) is set to n D2 When n A1 、n A2 、n D1 and n D2 Satisfy 0.03≤|nA1 -n D1 |≤0.3 and / or 0.03≤|n A2 -n D2 |≤0.3. By making n A1 and n D1 The difference and / or n A2 and n D2 When the difference is within the above range, both high haze and high transmittance can be achieved. Furthermore, when both the color conversion layer (A) and the color conversion layer (B) contain scattering particles, it is preferred to satisfy 0.03≤|n A1 -n D1 |≤0.3 and 0.03≤|n A2 -n D2 |≤0.3.

[0068] The average particle size of the scattering particles is not particularly limited as long as the haze value is within the above range, but is preferably 100 nm to 5000 nm, and more preferably 100 nm to 500 nm. By using scattering particles with an average particle size within the above range, the dispersibility in the binder resin becomes good, and the light scattering efficiency of the luminescent material is improved.

[0069] In addition, in the present invention, it is preferred that either or both of the color conversion layer (A) and the color conversion layer (B) contain scattering particles. The scattering particles are preferably contained in a state shifted to either the color conversion layer (A) or the color conversion layer (B). By the color conversion layer (A) containing scattering particles, the luminous efficiency of the (A) layer is improved, the peak wavelength is shortened, and a color conversion sheet with a larger color gamut can be obtained. In addition, by the color conversion layer (B) containing scattering particles, the color conversion efficiency of the (B) layer is improved, self-absorption is suppressed, and the peak wavelength is shortened. After the peak wavelength of the color conversion layer (B) is shortened, it can be closer to the visual acuity peak, and a color conversion sheet with higher brightness can be obtained. Therefore, from the viewpoint of a high color gamut, it is preferred that the content of scattering particles in the color conversion layer (A) is greater than the content of scattering particles in the color conversion layer (B), and it is most preferred that only the color conversion layer (A) contains scattering particles. On the other hand, from the viewpoint of high brightness, the content of the scattering particles in the color conversion layer (B) is preferably greater than that in the color conversion layer (A), and most preferably, only the color conversion layer (B) contains scattering particles.

[0070] When the pyrromethene derivatives described later or compounds with a small Stokes shift represented by general formula (6) or general formula (7) are used as the luminescent material contained in the color conversion layer, the self-absorption becomes stronger, so the effect of high brightness and high color gamut caused by the offset of scattering particles is significantly manifested.

[0071] <Resin Layer>

[0072] The color conversion sheet of the present invention has a resin layer. The resin layer is preferably present between the color conversion layer (A) and the color conversion layer (B). When the refractive index of the color conversion layer (A) is set to n A1 , let the refractive index of the color conversion layer (B) be n A2 , and the refractive index of the resin layer is set to n B When n A1 、n A2 and n B Satisfies the following relationship (1) or (2):

[0073] (1)n A1 >n B And n A2 >n B

[0074] (2)n A1 <n B And n A2 <n B .

[0075] The resin layer satisfying the relationship (1) is called a low refractive layer, and the resin layer satisfying the relationship (2) is called a high refractive layer. Since the resin layer has a refractive index different from that of the color conversion layer, light is reflected at the interface between each color conversion layer and the resin layer, thereby improving the color conversion efficiency. In addition, when the resin layer has a lower refractive index than the color conversion layer, more light can be reflected compared to the case where the resin layer is a high refractive layer, so that light leakage to the outside can be suppressed, which is more preferable.

[0076] <Low refractive layer>

[0077] As described above, one embodiment of the color conversion sheet of the present invention is a color conversion sheet having a low refractive layer as a resin layer. The low refractive layer is preferably present between the color conversion layer (A) and the color conversion layer (B). When the refractive index of the color conversion layer (A) is set to n A1 , let the refractive index of the color conversion layer (B) be n A2 , and the refractive index of the low refractive layer is set to n B When n A1 >n B And n A2 >n B By having a low refractive layer, light is reflected at the interface between each color conversion layer and the low refractive layer, so that light leakage outside each layer can be suppressed, thereby further improving the color conversion efficiency and obtaining good durability. C When n B <n CIn order to obtain stable color conversion efficiency, the difference in refractive index between the color conversion layer and the low refractive layer is more preferably such that 0.15 ≥ n A1 -n B ≥0.05 and 0.15≥n A2 -n B The relationship is ≥0.05.

[0078] As the material of the low refractive layer, if the refractive index satisfies n A1 >n B And n A2 >n B The resin is not particularly limited. Specifically, there can be cited photocurable resist materials having reactive vinyl groups, such as acrylic acid, methacrylic acid, polyvinyl cinnamate, and cyclorubber; epoxy resins, silicone resins (including organic polysiloxane cured products (crosslinked products) such as silicone rubber and silicone gel), urea resins, fluororesins, polycarbonate resins, acrylic resins, urethane resins, melamine resins, polyethylene resins, polyamide resins, phenolic resins, polyvinyl alcohol resins, polyvinyl butyral resins, cellulose resins, aliphatic ester resins, aromatic ester resins, aliphatic polyolefin resins, aromatic polyolefin resins, and other known materials. Among them, silicone resins or fluororesins, which are resins with a small refractive index, are preferred, and silicone resins are more preferred from the viewpoint of improving the durability of the color conversion sheet. By using a silicone resin as the resin for the resin layer, it is possible to prevent the luminescent material (a) and the luminescent material (b) from diffusing into the resin layer, and a color conversion sheet with a small change in chromaticity can be obtained even when used for a long time. Examples of the silicone resin include KR-114B manufactured by Shin-Etsu Chemical Co., Ltd., but the silicone resin is not limited thereto.

[0079] In addition, the low refractive layer is preferably directly adjacent to the color conversion layer (A), the low refractive layer, and the color conversion layer (B) in this order. When the layers are directly adjacent to each other, the color conversion efficiency of the color conversion layer (A) and the color conversion layer (B) can be greatly improved.

[0080] <High refractive layer>

[0081] As described above, one embodiment of the color conversion sheet of the present invention is a color conversion sheet having a high refractive layer as a resin layer. The high refractive layer is preferably present between the color conversion layer (A) and the color conversion layer (B). When the refractive index of the color conversion layer (A) is set to n A1 , let the refractive index of the color conversion layer (B) be n A2 , and the refractive index of the high refractive layer is set to n B When n A1 <n B And n A2 <n BBy having a high refractive layer, light is reflected at the interface between each color conversion layer and the high refractive layer, so that light leakage to the outside of each layer can be suppressed as in the case of having a low refractive layer, so the color conversion efficiency can be further improved, and good durability can be obtained. In addition, in order to obtain stable color conversion efficiency, the difference in refractive index between the color conversion layer and the high refractive layer is more preferably satisfied 0.15 ≥ n B -n A1 ≥0.05 and 0.15≥n B -n A2 The relationship is ≥0.05.

[0082] As the material of the high refractive layer, if the refractive index satisfies n A1 <n B And n A2 <n B The resin of the low refractive layer is not particularly limited, and the same material as that of the low refractive layer can be used. Among them, ester resins can be preferably used from the viewpoint of heat resistance or durability. As an example of ester resins, "Vylon" (registered trademark) 270 manufactured by Toyobo Co., Ltd. can be cited.

[0083] In addition, the high refractive layer is preferably directly adjacent to the color conversion layer (A), the high refractive layer, and the color conversion layer (B) in this order. When the layers are directly adjacent to each other, the color conversion efficiency of the color conversion layer (A) and the color conversion layer (B) can be greatly improved.

[0084] <Luminescent Materials>

[0085] The color conversion sheet of the present invention contains a luminescent material. The luminescent material in the present invention refers to a material that emits light of a wavelength different from that of the excitation light when irradiated with the excitation light. The color conversion layer (A) and the color conversion layer (B) may each contain one luminescent material or two or more luminescent materials.

[0086] The color conversion layer (A) and the color conversion layer (B) may each contain a plurality of layers in the color conversion sheet of the present invention. In such a case, the composition or morphology of each of the plurality of color conversion layers (A) may be the same or different. Similarly, the composition or morphology of each of the plurality of color conversion layers (B) may be the same or different.

[0087] In order to achieve efficient color conversion, it is preferred that the color conversion layer contain a material showing a luminescent property with a high quantum yield. As the luminescent material, known luminescent materials such as inorganic phosphors, fluorescent pigments, fluorescent dyes, and quantum dots can be cited. Furthermore, from the viewpoint of high luminescent properties, it is preferred that at least one of the color conversion layer (A) and the color conversion layer (B) contain an organic luminescent material.

[0088] Since organic light-emitting materials can absorb light emitted by a light source efficiently, they can achieve high efficiency when used in a color conversion layer. Examples of organic light-emitting materials include naphthalene, anthracene, phenanthrene, pyrene, Compounds having condensed aromatic rings such as tetracene, triphenylene, perylene, fluoranthene, fluorene, indene, or their derivatives;

[0089] Furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine and other compounds or their derivatives;

[0090] Borane derivatives;

[0091] Stilbene derivatives such as 1,4-distyrylbenzene, 4,4′-bis(2-(4-diphenylaminophenyl)vinyl)biphenyl, and 4,4′-bis(N-(stilbene-4-yl)-N-phenylamino)stilbene;

[0092] Aromatic acetylene derivatives, tetraphenylbutadiene derivatives, aldazine derivatives, pyrrole methylene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives;

[0093] Coumarin derivatives such as coumarin 6, coumarin 7, and coumarin 153;

[0094] Imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, triazole and other azole derivatives and their metal complexes;

[0095] Cyanine compounds such as indocyanine green;

[0096] Fluorescein eosin rhodamine and other xanthene compounds or thioanthene compounds;

[0097] Polyphenylene compounds, naphthalimide derivatives, phthalocyanine derivatives and metal complexes thereof, porphyrin derivatives and metal complexes thereof;

[0098] Oxazine compounds such as Nile red or Nile blue;

[0099] Helicene compounds;

[0100] Aromatic amine derivatives such as N,N′-diphenyl-N,N′-di(3-methylphenyl)-4,4′-diphenyl-1,1′-diamine; and

[0101] Organometallic complex compounds of iridium (Ir), ruthenium (Ru), rhodium (Rh), palladium (Pd), platinum (Pt), osmium (Os) and rhenium (Re);

[0102] etc. are preferred as organic light-emitting materials, but are not limited to them.

[0103] The organic light-emitting material may be a fluorescent light-emitting material or a phosphorescent light-emitting material. In order to achieve high color purity, a fluorescent light-emitting material is preferred.

[0104] Among these, a compound having a condensed aryl ring or a derivative thereof is preferably used in terms of high thermal stability and photostability.

[0105] In addition, compounds having a coordination bond are preferred from the viewpoint of solubility and diversity of molecular structure. Compounds containing boron such as a fluorinated boron complex are preferred from the viewpoint of having a small half-value width and being able to emit light with high efficiency.

[0106] Among them, pyrromethene derivatives are preferably used in terms of providing high fluorescence quantum yield and good durability. More preferred are compounds represented by the general formula (1).

[0107] [Chemistry 1]

[0108]

[0109] X is CR 7 or N. R 1 ~R 9 Each of the substituents may be the same or different and is selected from hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, a halogen group, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an ester group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxane group, a boryl group, a sulfone group, a phosphine oxide group, and a condensed ring formed with an adjacent substituent and an aliphatic ring.

[0110] In all the above groups, hydrogen may be deuterium. The above situation is also the same in the compounds or partial structures described below. In addition, in the following description, for example, the so-called substituted or unsubstituted aryl group with 6 to 40 carbon atoms refers to all aryl groups with 6 to 40 carbon atoms, including the carbon atoms contained in the substituents substituted in the aryl group. The same applies to other substituents with specified carbon atoms.

[0111] In addition, among all the above groups, as a substituent in the case of being substituted, it is preferably a group selected from an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an aryl thioether group, an aryl group, a heteroaryl group, a halogen, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an ester group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxane group, a boron group, a sulfonic group, and a phosphine oxide group, and more preferably a specific substituent considered as preferred in the description of each substituent. In addition, these substituents may be further substituted by the above substituents.

[0112] The term "unsubstituted" in the case of "substituted or unsubstituted" means that the substituent is a hydrogen atom or a deuterium atom. The same also applies to the case of "substituted or unsubstituted" in the compounds or partial structures described below.

[0113] In all the above-mentioned groups, the so-called alkyl group, for example, represents a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a sec-butyl group, a tert-butyl group, etc., which may or may not have a substituent. The additional substituent group in the case of substitution is not particularly limited, and for example, an alkyl group, a halogen group, an aryl group, a heteroaryl group, etc. can be cited, and the above aspects are also common in the following descriptions. In addition, the carbon number of the alkyl group is not particularly limited, and in terms of the ease of acquisition or the cost, it is preferably in the range of more than 1 and less than 20, and more preferably in the range of more than 1 and less than 8.

[0114] The cycloalkyl group refers to a saturated alicyclic hydrocarbon group such as cyclopropyl, cyclohexyl, norbornyl, adamantyl, etc., which may or may not have a substituent. The number of carbon atoms in the alkyl part is not particularly limited, but is preferably within a range of 3 or more and 20 or less.

[0115] The heterocyclic group refers to an aliphatic ring having atoms other than carbon in the ring, such as a pyran ring, a piperidine ring, and a cyclic amide, and 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 or more and 20 or less.

[0116] The alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as a vinyl group, an allyl group, and a butadienyl group, and 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 or more and 20 or less.

[0117] The cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond, such as a cyclopentenyl group, a cyclopentadienyl group, and a cyclohexenyl group, and may or may not have a substituent.

[0118] The alkynyl group refers to an unsaturated aliphatic hydrocarbon group containing a triple bond, such as an ethynyl group, and 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 or more and 20 or less.

[0119] The so-called alkoxy group refers to a functional group such as methoxy, ethoxy, propoxy, etc., which is bonded to an aliphatic hydrocarbon group through an ether bond, and the aliphatic hydrocarbon group may or may not have a substituent. The carbon number of the alkoxy group is not particularly limited, but is preferably in the range of 1 or more and 20 or less.

[0120] The so-called alkylthio group is an alkylthio group in which the oxygen atom of the ether bond of the alkoxy group is substituted with a sulfur atom. The hydrocarbon group of the alkylthio group may or may not have a substituent. The carbon number of the alkylthio group is not particularly limited, but is preferably in the range of 1 or more and 20 or less.

[0121] The aryl ether group refers to a functional group such as a phenoxy group bonded with an aromatic hydrocarbon group through 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 or more and 40 or less.

[0122] The so-called aryl thioether group is an aryl thioether group in which the oxygen atom of the ether bond of the aryl thioether group is substituted with a sulfur atom. The aromatic hydrocarbon group in the aryl thioether group may or may not have a substituent. The carbon number of the aryl thioether group is not particularly limited, but is preferably in the range of 6 or more and 40 or less.

[0123] The aryl group includes, for example, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthryl, anthracenyl, triphenylenyl, benzanthryl, The aromatic hydrocarbon groups include phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl, anthracenyl, pyrenyl, fluorenyl and triphenylene groups. The aromatic hydrocarbon groups include phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl, anthracenyl, pyrenyl, fluorenyl and triphenylene groups. The aromatic hydrocarbon groups include phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl, anthracenyl, pyrenyl, fluorenyl and triphenylene groups. The aromatic hydrocarbon groups include aryl, fluorenyl, fluorenyl, triphenylenyl, benzopropene, dibenzoanthryl, peryl and helicenyl groups. Among them, the aromatic hydrocarbon groups include phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl, anthracenyl, pyrenyl, fluorenyl and triphenylene groups. The aromatic hydrocarbon groups may or may not have substituents. The number of carbon atoms in the aromatic hydrocarbon group is not particularly limited, but is preferably 6 or more and 40 or less, and more preferably 6 or more and 30 or less.

[0124] In R 1 ~R 9 In the case of a substituted or unsubstituted aryl group, the aryl group is preferably a group selected from phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl and anthracenyl, more preferably a group selected from phenyl, biphenyl, terphenyl and naphthyl, further preferably a group selected from phenyl, biphenyl and terphenyl, particularly preferably a phenyl.

[0125] When each substituent is further substituted with an aryl group, the aryl group is preferably a group selected from phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthryl and anthracenyl, more preferably a group selected from phenyl, biphenyl, terphenyl and naphthyl, and particularly preferably a phenyl group.

[0126] The so-called heteroaryl group refers to, for example, a cyclic aromatic group having atoms other than carbon in one or more rings, such as pyridyl, furyl, thienyl, quinolyl, isoquinolyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, naphthyridinyl, cinnolinyl, phthalazinyl, quinoxalinyl, quinazolinyl, benzofuranyl, benzothienyl, indolyl, dibenzofuranyl, dibenzothienyl, carbazolyl, benzocarbazolyl, carbolinyl group, indolecarbazolyl, benzofuranocarbazolyl, benzothienocarbazolyl, dihydroindenocarbazolyl, benzoquinolyl, acridinyl, dibenzoacridinyl, benzimidazolyl, imidazopyridinyl, benzoxazolyl, benzothiazolyl, and phenanthrolinyl. The so-called naphthyridinyl group refers to any one of 1,5-naphthyridinyl, 1,6-naphthyridinyl, 1,7-naphthyridinyl, 1,8-naphthyridinyl, 2,6-naphthyridinyl and 2,7-naphthyridinyl. The heteroaryl group may or may not have a substituent. The number of carbon atoms in the heteroaryl group is not particularly limited, but is preferably 2 or more and 40 or less, and more preferably 2 or more and 30 or less.

[0127] In R 1 ~R 9 In the case of a substituted or unsubstituted heteroaryl group, the heteroaryl group is preferably a group selected from pyridyl, furyl, thienyl, quinolyl, pyrimidinyl, triazine, benzofuranyl, benzothienyl, indolyl, dibenzofuranyl, dibenzothienyl, carbazolyl, benzimidazolyl, imidazopyridyl, benzoxazolyl, benzothiazolyl and phenanthroline, more preferably a group selected from pyridyl, furyl, thienyl and quinolyl. Pyridyl is particularly preferred.

[0128] When each substituent is further substituted with a heteroaryl group, the heteroaryl group is preferably a group selected from pyridyl, furyl, thienyl, quinolyl, pyrimidinyl, triazine, benzofuranyl, benzothienyl, indolyl, dibenzofuranyl, dibenzothienyl, carbazolyl, benzimidazolyl, imidazopyridyl, benzoxazolyl, benzothiazolyl and phenanthroline, more preferably a group selected from pyridyl, furyl, thienyl and quinolyl. Pyridyl is particularly preferred.

[0129] The halogen refers to an atom selected from fluorine, chlorine, bromine and iodine. In addition, the carbonyl group, carboxyl group, ester group and carbamoyl group may or may not have a substituent. Here, as the substituent, for example, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group and the like can be cited, and these substituents may be further substituted.

[0130] The amino group is a substituted or unsubstituted amino group. As a substituent in the case of substitution, for example, aryl, heteroaryl, straight-chain alkyl, branched alkyl, etc. can be cited. As aryl and heteroaryl, a group selected from phenyl, naphthyl, pyridyl and quinolyl is preferred. These substituents may be further substituted. The carbon number is not particularly limited, preferably 2 or more and 50 or less, more preferably 6 or more and 40 or less, and particularly preferably 6 or more and 30 or less.

[0131] The so-called silyl group refers to, for example, an alkylsilyl group such as trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, propyldimethylsilyl, vinyldimethylsilyl, or an arylsilyl group such as phenyldimethylsilyl, tert-butyldiphenylsilyl, triphenylsilyl, trinaphthylsilyl. The substituent on silicon may be further substituted. The carbon number of the silyl group is not particularly limited, but is preferably in the range of 1 or more and 30 or less.

[0132] The so-called siloxane group refers to, for example, a silicon compound group such as trimethylsiloxane group with an ether bond therebetween. The substituent on silicon may be further substituted. In addition, the so-called boron group refers to a substituted or unsubstituted boron group. As a substituent in the case of substitution, for example, an aryl group, a heteroaryl group, a straight-chain alkyl group, a branched alkyl group, an aryl ether group, an alkoxy group, a hydroxyl group, etc. may be cited. Among them, a group selected from an aryl group and an aryl ether group is preferred. In addition, the so-called sulfo group refers to a substituted or unsubstituted sulfo group. As a substituent in the case of substitution, for example, an aryl group, a heteroaryl group, a straight-chain alkyl group, a branched alkyl group, an aryl ether group, an alkoxy group, etc. may be cited. Among them, a straight-chain alkyl group or an aryl group is preferred.

[0133] The phosphine oxide group refers to -P(=O)R 10 R 11 The base represented by R 10 R 11 Selected from R 1 ~R 9 in the same group.

[0134] The condensed ring and aliphatic ring formed with adjacent substituents refer to any two adjacent substituents (e.g., R 1 With R 2) are bonded to each other to form a conjugated or non-conjugated cyclic skeleton. As the constituent elements of such condensed rings and aliphatic rings, in addition to carbon, elements selected from nitrogen, oxygen, sulfur, phosphorus and silicon may also be contained. In addition, these condensed rings and aliphatic rings may be further condensed with other rings.

[0135] The compound represented by the general formula (1) exhibits a high luminescence quantum yield and a small half-value width of the luminescence spectrum, and thus can achieve both efficient color conversion and high color purity. Furthermore, the compound represented by the general formula (1) can adjust various characteristics or properties such as luminescence efficiency, color purity, thermal stability, light stability and dispersibility by introducing appropriate substituents into appropriate positions. For example, 1 , R 3 , R 4 and R 6 Compared with the case where all hydrogen is present, R 1 , R 3 , R 4 and R 6 When at least one of the groups is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, better thermal stability and photostability are exhibited.

[0136] In R 1 , R 3 , R 4 and R 6 When at least one of the alkyl groups is a substituted or unsubstituted alkyl group, the alkyl group is preferably an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, etc. Furthermore, as the alkyl group, from the viewpoint of excellent thermal stability, it is preferably a group selected from a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group. In addition, from the viewpoint of preventing concentration extinction and improving the quantum yield of luminescence, as the alkyl group, a tert-butyl group with a large steric volume is more preferred. On the other hand, from the viewpoint of ease of synthesis and ease of obtaining raw materials, a methyl group can also be preferably used as the alkyl group.

[0137] In R 1 , R 3 , R 4 and R 6 When at least one of is a substituted or unsubstituted aryl group, the aryl group is preferably a group selected from a phenyl group, a biphenyl group, a terphenyl group and a naphthyl group, more preferably a phenyl group and a biphenyl group, and particularly preferably a phenyl group.

[0138] In R 1 , R 3 , R 4 and R 6When at least one of is a substituted or unsubstituted heteroaryl group, the heteroaryl group is preferably a group selected from pyridyl, quinolyl and thienyl, more preferably pyridyl or quinolyl, and particularly preferably pyridyl.

[0139] In R 1 , R 3 , R 4 and R 6 All of them may be the same or different, and when they are substituted or unsubstituted alkyl groups, they are preferred because they have good solubility in the binder resin or solvent. In such a case, the alkyl group is preferably a methyl group from the viewpoint of ease of synthesis and ease of obtaining raw materials.

[0140] In R 1 , R 3 , R 4 and R 6 In the case where they are the same or different, and are substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, they show better thermal stability and light stability, and thus are preferred. In such a case, more preferably R 1 , R 3 , R 4 and R 6 Each of them may be the same as or different from each other and is a substituted or unsubstituted aryl group.

[0141] Although there are substituents that improve multiple properties, there are limited substituents that show sufficient performance in all properties. It is particularly difficult to achieve both high luminous efficiency and high color purity. Therefore, a compound that has achieved a balance in terms of luminous properties or color purity can be obtained by introducing a variety of substituents into the compound represented by general formula (1).

[0142] Especially in R 1 , R 3 , R 4 and R 6 In the case where they are the same or different and are substituted or unsubstituted aryl groups, for example, R 1 ≠R 4 , R 3 ≠R 6 , R 1 ≠R 3 or R 4 ≠R 6 Here, “≠” indicates different structures. For example, R 1 ≠R 4 Represents R 1 With R 4By introducing a plurality of substituents as described above, an aromatic group that affects color purity and an aromatic group that affects luminous efficiency can be simultaneously introduced, thereby enabling fine adjustment.

[0143] Among them, from the viewpoint of improving the luminous efficiency and color purity in a well-balanced manner, R 1 ≠R 3 or R 4 ≠R 6 In the above case, relative to the compound represented by the general formula (1), one or more aryl groups that affect color purity can be introduced into the pyrrole rings on both sides, and aryl groups that affect luminous efficiency can be introduced into other positions, thereby maximizing the properties of the above two groups. 1 ≠R 3 or R 4 ≠R 6 In the case of R 1 =R 6 and R 3 =R 4 .

[0144] As the aryl group that affects the color purity, it is preferably an aryl group substituted with an electron-donating group. The so-called electron-donating group, in organic electronics theory, refers to an atomic group that supplies electrons to the substituted atomic group by an inductive effect or a resonance effect. As an electron-donating group, a base that takes a negative value as the substituent constant (σp (pairs)) of the Hammett equation can be cited. The substituent constant (σp (pairs)) of the Hammett equation can be cited from the revised 5th edition (page II-380) of the Chemistry Handbook Basics.

[0145] Specific examples of electron-donating groups include alkyl groups (σp of methyl group: -0.17) or alkoxy groups (σp of methoxy group: -0.27), amino groups (σp of -NH2: -0.66), etc. In particular, alkyl groups having 1 to 8 carbon atoms or alkoxy groups having 1 to 8 carbon atoms are preferred, and groups selected from methyl groups, ethyl groups, tert-butyl groups, and methoxy groups are more preferred. From the viewpoint of dispersibility, tert-butyl groups or methoxy groups are particularly preferred. When these are used as the electron-donating groups, extinction caused by aggregation of molecules can be prevented in the compound represented by the general formula (1). The substitution position of the substituent is not particularly limited, but in order to improve the photostability of the compound represented by the general formula (1), it is necessary to suppress the bending of the bond, and therefore it is preferred to bond to the meta-position or para-position relative to the bonding position to the pyrromethene skeleton. On the other hand, as the aryl group that mainly affects the luminous efficiency, an aryl group having a bulky substituent such as a tert-butyl group, an adamantyl group, a methoxy group, etc. is preferred.

[0146] In R 1 , R 3 , R 4 and R 6 In the case where they may be the same or different and are substituted or unsubstituted aryl groups, R 1 , R 3 , R 4 and R 6 They may be the same or different and are substituted or unsubstituted phenyl. 1 , R 3 , R 4 and R 6 More preferably, they are selected from the following Ar-1 to Ar-6. In such a case, R 1 , R 3 , R 4 and R 6 There is no particular limitation on the combination.

[0147] [Chemistry 2]

[0148]

[0149] R 2 and R 5 Any of hydrogen, alkyl, carbonyl, ester and aryl is preferred. Among them, hydrogen or alkyl is preferred from the viewpoint of thermal stability, and hydrogen is more preferred from the viewpoint of easily obtaining a narrow half-value width in the emission spectrum.

[0150] R 8 and R 9 It is preferably a group selected from an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, an aryl ether group, fluorine, a fluorine-containing alkyl group, a fluorine-containing heteroaryl group or a fluorine-containing aryl group, a fluorine-containing alkoxy group, a fluorine-containing aryl ether group and a cyano group. In terms of stability to excitation light and obtaining a higher fluorescence quantum yield, it is more preferably a fluorine group, a cyano group or a fluorine-containing aryl group. In terms of ease of synthesis, it is more preferably a fluorine group or a cyano group. Furthermore, R 8 or R 9 Any one of them is preferably a cyano group. By introducing a cyano group, durability is improved.

[0151] Here, the fluorine-containing aryl group refers to an aryl group containing fluorine, for example, fluorophenyl, trifluoromethylphenyl, and pentafluorophenyl. The fluorine-containing heteroaryl group refers to a heteroaryl group containing fluorine, for example, fluoropyridyl, trifluoromethylpyridyl, and trifluoropyridyl. The fluorine-containing alkyl group refers to an alkyl group containing fluorine, for example, trifluoromethyl, pentafluoroethyl, etc.

[0152] In general formula (1), from the viewpoint of photostability, X is preferably CR 7 . In X is CR 7When the substituent R 7 The durability of the compound represented by the general formula (1) is greatly affected, that is, the luminescence intensity of the compound decreases over time. 7 When R is hydrogen, the reactivity of the site is high, so the site is easy to react with moisture or oxygen in the air. This will cause the decomposition of the compound represented by general formula (1). 7 In the case of a substituent having a large degree of freedom of movement of the molecular chain such as an alkyl group, the reactivity is indeed reduced, but the compounds aggregate with each other over time in the color conversion layer, resulting in a decrease in the luminescence intensity due to concentration extinction. 7 It is preferably a group that is rigid and has a small degree of freedom of movement and is unlikely to cause aggregation, and specifically, it is preferably a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group.

[0153] In terms of providing a higher fluorescence quantum yield and being less susceptible to thermal decomposition, and in terms of photostability, it is preferred that X is CR 7 And R 7 The aryl group is preferably a group selected from a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, and an anthracenyl group from the viewpoint of not impairing the emission wavelength.

[0154] Furthermore, in order to improve the photostability of the compound represented by the general formula (1), it is necessary to appropriately suppress R 7 The reason is that if the bending is too large, the reactivity to the excitation light becomes high, and the photostability decreases. From this point of view, as R 7 , preferably substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, more preferably substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl. Particularly preferably substituted or unsubstituted phenyl.

[0155] In addition, R 7 A substituent that is moderately bulky is preferred. 7 Having a certain degree of bulkiness can prevent the aggregation of molecules, and as a result, the luminous efficiency and durability of the compound represented by the general formula (1) are further improved.

[0156] As further preferred examples of such bulky substituents, R represented by the following general formula (2) can be mentioned: 7 structure.

[0157] [Chemistry 3]

[0158]

[0159] In the general formula (2), r is selected from the group consisting of hydrogen, alkyl, cycloalkyl, heterocyclic, alkenyl, cycloalkenyl, alkynyl, hydroxyl, thiol, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, halogen, cyano, aldehyde, carbonyl, carboxyl, ester, carbamoyl, amino, nitro, silyl, siloxane, boron, sulfonyl, and phosphine oxide. k is an integer of 1 to 3. When k is 2 or more, r may be the same or different.

[0160] From the viewpoint of providing a higher luminescence quantum yield, r is preferably a substituted or unsubstituted aryl group. Among the aryl groups, phenyl or naphthyl can be cited as preferred examples. When r is an aryl group, k in the general formula (2) is preferably 1 or 2, and more preferably 2 from the viewpoint of further preventing the aggregation of molecules. Furthermore, when k is 2 or more, at least one of r is preferably substituted with an alkyl group. As the alkyl group in the above case, from the viewpoint of thermal stability, a group selected from a methyl group, an ethyl group and a tert-butyl group can be cited as a particularly preferred example.

[0161] In addition, from the viewpoint of controlling the fluorescence wavelength or absorption wavelength, or improving the compatibility with the solvent, r is preferably a substituted or unsubstituted alkyl, a substituted or unsubstituted alkoxy or a halogen, and more preferably a group selected from a methyl group, an ethyl group, a tert-butyl group and a methoxy group. From the viewpoint of dispersibility, a tert-butyl group or a methoxy group is particularly preferred. From the viewpoint of preventing extinction caused by agglomeration of molecules, it is more effective when r is a tert-butyl group or a methoxy group.

[0162] In addition, as another aspect of the compound represented by the general formula (1), preferably R 1 ~R 7 At least one of them is an electron withdrawing group. Particularly preferably, (1) R 1 ~R 6 At least one of them is an electron-withdrawing group; (2) R 7 is an electron-withdrawing group; or (3) R 1 ~R 6 At least one of them is an electron-withdrawing group and R 7 By introducing an electron-withdrawing group into the pyrromethene skeleton of the compound as described above, the electron density of the pyrromethene skeleton can be greatly reduced. As a result, the stability of the compound with respect to oxygen is further improved, and as a result, the durability of the compound can be further improved.

[0163] The so-called electron withdrawing group, also known as an electron-withdrawing group, is an atomic group that attracts electrons from a substituted atomic group by an inductive effect or a resonance effect in organic electronic theory. As an electron withdrawing group, a group that takes a positive value as the substituent constant (σp (para)) of Hammett's rule can be cited. The substituent constant (σp (para)) of Hammett's rule can be cited from the revised 5th edition (page II-380) of the Basic Compendium of Chemistry. Furthermore, although the phenyl group also has an example of taking a positive value as described above, in the present invention, the phenyl group is not included in the electron withdrawing group.

[0164] Examples of electron withdrawing groups include -F (σp: +0.06), -Cl (σp: +0.23), -Br (σp: +0.23), -I (σp: +0.18), -CO2R 12 (σp:R 12 +0.45 for ethyl), -CONH2 (σp: +0.38), -COR 12 (σp:R 12 +0.49 for methyl), -CF3 (σp: +0.50), -SO2R 12 (σp:R 12 When it is a methyl group, it is +0.69), -NO2 (σp: +0.81), etc. 12 Each independently represents a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 1 to 30 carbon atoms. Specific examples of these groups include the same examples as described above.

[0165] In the general formula (1), R 2 and R 5 At least one of them is preferably an electron withdrawing group. The reason is that R 2 and R 5 The substitution position has a great influence on the electron density of the pyrromethene skeleton. 2 and R 5 The introduction of an electron-withdrawing group can effectively reduce the electron density of the pyrromethene skeleton, further improve the stability to oxygen, and thus further improve the durability.

[0166] Furthermore, in the general formula (1), R 2 and R 5 An electron withdrawing group is more preferred because the stability of the compound represented by the general formula (1) to oxygen is further improved, and the durability can be greatly improved.

[0167] The electron withdrawing group is preferably a group containing a fluorine atom. By using a group containing a fluorine atom, the electron density of the pyrromethene skeleton can be further reduced, and the stability of the compound represented by the general formula (1) to oxygen can be improved, thereby improving the durability.

[0168] Preferred electron withdrawing groups include fluorine, fluorine-containing aryl groups, fluorine-containing heteroaryl groups, fluorine-containing alkyl groups, substituted or unsubstituted acyl groups, substituted or unsubstituted ester groups, substituted or unsubstituted amide groups, substituted or unsubstituted sulfonyl groups, substituted or unsubstituted sulfonate groups, substituted or unsubstituted sulfonamide groups, or cyano groups. This is because these groups are difficult to chemically decompose.

[0169] More preferred electron withdrawing groups include fluorinated alkyl groups, substituted or unsubstituted acyl groups, substituted or unsubstituted ester groups, substituted or unsubstituted amide groups, substituted or unsubstituted sulfonyl groups, substituted or unsubstituted sulfonate groups, substituted or unsubstituted sulfonamide groups, or cyano groups. This is because these groups can prevent concentration extinction and improve the luminescence quantum yield. A particularly preferred electron withdrawing group is a substituted or unsubstituted ester group.

[0170] As further preferred electron withdrawing groups, there can be cited: fluorine-containing acyl groups, fluorine-containing ester groups, fluorine-containing amide groups, fluorine-containing sulfonyl groups, fluorine-containing sulfonate groups, and fluorine-containing sulfonamide groups. These groups can effectively reduce the electron density of the pyrromethene boron complex skeleton. As a result, the stability of the compound represented by general formula (1) to oxygen is improved, and as a result, the durability can be further improved.

[0171] Among them, R is preferred because it can improve durability without reducing color purity. 2 and R 5 At least one of them may be the same or different and is a substituted or unsubstituted ester group. In particular, from the viewpoint of improving durability, R 2 and R 5 Each of them may be the same as or different from each other and is a substituted or unsubstituted ester group.

[0172] As a preferred example of the compound represented by the general formula (1), the following can be mentioned: 1 , R 3 , R 4 and R 6 are the same or different and are substituted or unsubstituted alkyl, and X is CR 7 And R 7 is a group represented by the general formula (2). In the above case, R 7 In the above, r is particularly preferably a substituted or unsubstituted phenyl group.

[0173] Another preferred example of the compound represented by the general formula (1) includes the following: 1 , R 3 , R 4 and R 6 They may be the same or different and are selected from Ar-1 to Ar-6, and X is CR 7 And R 7 is a group represented by the general formula (2). In the above case, R 7 Among them, r is more preferably tert-butyl or methoxy, and particularly preferably r is methoxy.

[0174] Another preferred example of the compound represented by the general formula (1) includes the following: 1 , R 3 , R 4 and R 6 are the same or different and are substituted or unsubstituted alkyl, and R 2 and R 5 are the same or different and are substituted or unsubstituted ester groups, and X is CR 7 And R 7 is a group represented by the general formula (2). In the above case, R 7 In the above, r is particularly preferably a substituted or unsubstituted phenyl group.

[0175] Another preferred example of the compound represented by the general formula (1) includes the following: 1 , R 3 , R 4 and R 6 They may be the same or different and are selected from Ar-1 to Ar-6, and R 2 and R 5 are the same or different and are substituted or unsubstituted ester groups, and X is CR 7 And R 7 is a group represented by the general formula (2). In the above case, R 7 Among them, r is more preferably tert-butyl or methoxy, and particularly preferably r is methoxy.

[0176] Examples of the compound represented by the general formula (1) are shown below, but the compound is not limited to these.

[0177] [Chemistry 4]

[0178]

[0179] [Chemistry 5]

[0180]

[0181] [Chemistry 6]

[0182]

[0183] [Chemistry 7]

[0184]

[0185] [Chemistry 8]

[0186]

[0187] [Chemistry 9]

[0188]

[0189] [Chemistry 10]

[0190]

[0191] [Chemistry 11]

[0192]

[0193] [Chemistry 12]

[0194]

[0195] [Chemistry 13]

[0196]

[0197] The compound represented by the general formula (1) can be synthesized by the method described in, for example, Japanese Patent Publication No. 8-509471 or Japanese Patent Application Laid-Open No. 2000-208262. That is, the target pyrromethene metal complex can be obtained by reacting a pyrromethene compound with a metal salt in the presence of a base.

[0198] In addition, regarding the synthesis of pyrromethene-boron fluoride complexes, reference may be made to the methods described in "Journal of Organic Chemistry (J.Org.Chem.)", vol.64, No.21, pp.7813-7819 (1999), "Angew.Chem., Int.Ed.Engl.", vol.36, pp.1333-1335 (1997), etc., to synthesize the compound represented by the general formula (1). For example, the following method can be cited: a compound represented by the following general formula (3) and a compound represented by the following general formula (4) are heated in 1,2-dichloroethane in the presence of phosphorus oxychloride, and then reacted with a compound represented by the following general formula (5) in 1,2-dichloroethane in the presence of triethylamine, thereby obtaining a compound represented by the general formula (1). However, the present invention is not limited thereto. Here, R 1 ~R 9 Same as the above description. J represents a halogen.

[0199] [Chemistry 14]

[0200]

[0201] Furthermore, when an aryl group or heteroaryl group is introduced, a method of generating a carbon-carbon bond by a coupling reaction of a halogenated derivative with a boric acid or borate ester derivative can be cited, but the present invention is not limited thereto. Similarly, when an amino group or a carbazole group is introduced, a method of generating a carbon-nitrogen bond by a coupling reaction of a halogenated derivative with an amine or carbazole derivative under a metal catalyst such as palladium can also be cited, but the present invention is not limited thereto.

[0202] In addition to the compound represented by the general formula (1), the color conversion layer of the embodiment of the present invention may contain other compounds as needed. For example, in order to further improve the energy transfer efficiency from the excitation light to the compound represented by the general formula (1), an auxiliary dopant such as rubrene may also be contained. In addition, in the case of adding a luminescent color other than the luminescent color of the compound represented by the general formula (1), a desired organic luminescent material may be added, for example: organic luminescent materials such as coumarin-based pigments and rhodamine-based pigments. In addition, in addition to these organic luminescent materials, known luminescent materials such as inorganic phosphors, fluorescent pigments, fluorescent dyes, quantum dots, and compounds emitting delayed fluorescence may also be added in combination.

[0203] Examples of organic light-emitting materials other than the compound represented by the general formula (1) are shown below, but the present invention is not particularly limited to these.

[0204] [Chemistry 15]

[0205]

[0206] Examples of inorganic phosphors include SrAl2O4:Eu, Y2SiO5:Ce, Tb, MgAl 11 O 19 :Ce, Tb, Sr7Al 12 O 25 :Eu, MgGa2S4:Eu, CaGa2S4:Eu, SrGa2S4:Eu, BaGa2S4:Eu and other green phosphors; or Sr5(PO4)3Cl:Eu, (SrCaBa)5(PO4)3Cl:Eu, (BaCa)5(PO4)3Cl:Eu, B5O9Cl:Eu,Mn, Mg(PO4)6Cl2:Eu,Mn, Ca(PO4)6Cl2:Eu,Mn, Sr(PO4)6Cl2:Eu,Mn, Ba(PO4)6Cl2:Eu,Mn and other blue phosphors; or red phosphors such as Y2O2S:Eu, La2O2S:Eu, Y2O3:Eu, Gd2O2S:Eu, K2SiF6:Mn and the like. In addition, Y3(Al,Ga)5O 12 :Ce,(Y,Gd)3Al5O 12 :Ce,Lu3Al5O 12 :Ce,Y3Al5O 12 :Ce and other YAG phosphors, Tb3Al5O 12 :Ce and other TAG phosphors, (Ba, Sr)2SiO4:Eu phosphors or Ca3Sc2Si3O 12 :Ce-based phosphors, (Sr, Ba, Mg)2SiO4:Eu and other silicate-based phosphors, (Ca, Sr)2Si5N8:Eu, (Ca, Sr)AlSiN3:Eu, CaSiAlN3:Eu and other nitride-based phosphors, Cax(Si, Al) 12 (O, N) 16 : Eu and other nitrogen oxide phosphors, and (Ba, Sr, Ca)Si2O2N2: Eu phosphors, Ca8MgSi4O 16 Cl2:Eu-based phosphor, SrAl2O4:Eu, Sr4Al 14 O 25 : Phosphors such as Eu.

[0207] Quantum dots are phosphors with excellent quantum efficiency. They have discrete energy levels by enclosing electrons, holes or excitons in all directions in three-dimensional space in semiconductor crystals of nanometer size (e.g., diameter of about 2nm to 10nm). By changing the size of the dots, the peak wavelength (luminescent color) of the luminescent light can be freely selected. As materials used in quantum dots, materials such as Zn, Cd, Pb, etc. that can become divalent cations and O, S, Se, Te, etc. that can become divalent anions (e.g., cadmium selenide (CdSe), zinc sulfide (ZnS), etc.), materials such as Ga, In, etc. that can become trivalent cations and P, As, Sb, etc. that can become trivalent anions (e.g., indium phosphide (InP), gallium arsenide (GaAs), etc.), and chalcopyrite compounds (CuInSe2, etc.) can be listed. As a preferred example of the material of the quantum dot phosphor, CdSe can be listed.

[0208] Compounds that emit delayed fluorescence are explained in "The Most Advanced Organic EL" (edited by Chiba Ya Andachi and Hiroshi Fujimoto, published by CMC Publishing) pages 87 to 103. The document explains that by making the energy levels of the singlet excited state and triplet excited state of the luminescent material close, reverse energy transfer from the triplet excited state to the singlet excited state with a low migration probability is usually generated with high efficiency, thereby showing the generation mechanism of thermally activated delayed fluorescence (TADF) and delayed fluorescence. The luminescence of delayed fluorescence can be confirmed by transition photoluminescence (PL) measurement.

[0209] In this specification, a compound that efficiently transitions from a triplet excited state to a singlet excited state and emits fluorescence, including a compound that exhibits thermally activated delayed fluorescence, is referred to as a “compound that emits delayed fluorescence”.

[0210] Usually, fluorescence is emitted from a singlet excited state generated after the luminescent material is excited by light. The triplet excited state of the luminescent material generated by intersystem crossing is thermally inactivated at room temperature and does not emit fluorescence. On the other hand, as described above, even if the compound emitting delayed fluorescence generates a triplet excited state, it will quickly transform into a singlet excited state and then emit fluorescence, so the triplet excited state that does not contribute to luminescence in a common fluorescent material can also contribute to fluorescence. Therefore, if a compound that exhibits thermally activated delayed fluorescence is used, high-efficiency luminescence can be obtained.

[0211] In addition, the triplet excited state of the compound emitting delayed fluorescence can be quickly converted to a singlet excited state, so it has the characteristic of not easily generating singlet oxygen. It is believed that singlet oxygen will cause degradation due to oxidation of the luminescent material because it has a strong oxidizing power. It is believed that singlet oxygen is generated by the exchange of electrons and energy between the triplet excited state of the luminescent material and the triplet oxygen molecules in the ground state. As described above, the compound emitting delayed fluorescence has the property that the triplet excited state is quickly converted to the singlet excited state, that is, the life span of the triplet excited state is short. Therefore, the probability of direct collision between the triplet excited state of the luminescent material and the triplet oxygen in the ground state becomes smaller, and singlet oxygen is not easily generated. Moreover, according to the above characteristics, it is found that if a compound showing thermally activated delayed fluorescence is used, the degradation of the luminescent material is suppressed, the change of chromaticity over time is suppressed, and the durability of the luminescent material can be improved.

[0212] As a molecular design that makes the energy level of the singlet excited state close to the energy level of the triplet excited state, it is effective to bond the electron donor skeleton to the electron acceptor skeleton in the same molecule. In this way, the HOMO (highest occupied molecular orbital) orbit and the LUMO (lowest unoccupied molecular orbital) orbit can be separated in the molecule. The electron donor skeleton and the electron acceptor skeleton can be bonded directly or via a linking group. As the linking group in the above case, a skeleton containing aromatic hydrocarbons is preferred.

[0213] The so-called electron donor skeleton, for example, can be cited a skeleton having an amine nitrogen atom. Among them, preferably a skeleton containing diarylamine or triarylamine, a skeleton containing carbazole, a skeleton containing benzocarbazole, a skeleton containing indolecarbazole, a skeleton containing phenoxazine, and a skeleton containing phenothiazine. Among these, more preferably a skeleton containing carbazole, a skeleton containing benzocarbazole, a skeleton containing indolecarbazole, and a skeleton containing phenoxazine, and more preferably a skeleton containing carbazole and a skeleton containing phenoxazine.

[0214] On the other hand, electron acceptor skeletons generally include skeletons containing substituents with electron withdrawing properties. The so-called electron withdrawing group, also known as an electron withdrawing group, refers to an atomic group that attracts electrons from a substituted atomic group through an inductive effect or a resonance effect in organic electronics theory. As an electron withdrawing group, an electron withdrawing group that takes a positive value as the substituent constant (σp (para)) of Hammett's rule can be cited. The substituent constant (σp (para)) of Hammett's rule can be cited from the revised 5th edition of the Basic Compendium of Chemistry (page II-380).

[0215] In addition, although there are examples where the phenyl group also takes a positive value, the phenyl group is not included in the electron withdrawing group of the present application.

[0216] Examples of electron withdrawing groups include -F (σp: +0.20), -Cl (σp: +0.28), -Br (σp: +0.30), -I (σp: +0.30), -CO2R 12 (σp:R 12 +0.45 for ethyl), -CONH2 (σp: +0.38), -COR 12 (σp:R 12 +0.49 for methyl), -CF3 (σp: +0.51), -SO2R 12 (σp:R 12 When it is a methyl group, it is +0.69), -NO2 (σp: +0.81), etc. 12 Each independently represents a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 1 to 30 carbon atoms. Specific examples of the above groups include the same ones as described above.

[0217] Among them, preferred are a skeleton containing a heteroaryl group having a partial structure formed by double bonds between a carbon atom and a nitrogen atom, a skeleton containing a fluorinated substituent, a skeleton containing a cyano group, a skeleton containing a carbonyl group, a skeleton containing a sulfoxide or disulfoxide, and a skeleton containing a phosphine oxide group, etc. Among these, from the viewpoint of the stability of the compound, a skeleton containing a heteroaryl group having a partial structure formed by double bonds between a carbon atom and a nitrogen atom, a skeleton containing a fluorinated substituent, and a skeleton containing a cyano group are further preferred.

[0218] Among the skeletons of heteroaryl groups containing a partial structure formed by double bonds between carbon atoms and nitrogen atoms, specifically, preferred are skeletons containing pyridine, pyrimidine, pyrazine, triazine, quinoline, quinoxaline, quinazoline or phenanthroline, among which skeletons containing pyrimidine, triazine, quinoxaline or quinazoline are more preferred, and skeletons containing triazine are further preferred.

[0219] In the skeleton containing a fluorinated substituent, a skeleton containing a fluorinated aryl or a fluoroalkyl group is more preferred. As the skeleton containing a fluorinated aryl group, a fluorinated benzene ring is preferably used, and specifically, a skeleton containing fluorobenzene, difluorobenzene, trifluorobenzene, tetrafluorobenzene or pentafluorobenzene is more preferred. As the skeleton containing a fluoroalkyl group, a skeleton containing a benzene ring substituted with a trifluoromethyl group is preferably used, and among these, a skeleton containing a mono(trifluoromethyl)benzene or a bis(trifluoromethyl)benzene is also more preferred.

[0220] Among the skeletons having a cyano group, a skeleton containing cyanobenzene, dicyanobenzene, or tricyanobenzene is more preferred.

[0221] An example of a compound in which an electron donor skeleton and an electron acceptor skeleton as described above are bonded is shown below, but the present invention is not particularly limited to these. It is known from prior literature that the compound shown here emits delayed fluorescence.

[0222] [Chemistry 16]

[0223]

[0224] In addition, as the compound emitting delayed fluorescence, in addition to the compound in which an electron donor skeleton and an electron acceptor skeleton are bonded to each other, a compound represented by the general formula (6) or the general formula (7) is preferred.

[0225] [Chemistry 17]

[0226]

[0227] In general formula (6) and general formula (7), ring Za, ring Zb and ring Zc are each independently a substituted or unsubstituted ring-forming aryl ring having 6 to 30 carbon atoms, or a substituted or unsubstituted ring-forming heteroaryl ring having 5 to 30 carbon atoms. As the unsubstituted ring-forming aryl ring having 6 to 30 carbon atoms, aromatic hydrocarbon rings such as benzene ring, naphthalene ring, phenanthrene ring, glycerol ring, anthracene ring, pyrene ring, etc. can be cited. Among these, benzene ring is also preferred from the viewpoint of ensuring solubility. In addition, as the heteroaryl ring having 5 to 30 carbon atoms, aromatic heteroaryl ring structures such as pyridine ring, quinoline ring, phenanthroline ring, etc. can be cited. From the viewpoint of ease of obtaining raw materials or ease of synthesis, pyridine ring is preferred. Ring Za, ring Zb and ring Zc are preferably benzene rings. This is because the π-conjugated system of the compound represented by the general formula (6) or (7) is efficiently expanded, and inverse intersystem crossing occurs more efficiently from the triplet excited state to the singlet excited state, thereby further improving durability.

[0228] In the above description and the following description, for example, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms means that the number of carbon atoms in the substituent substituted in the aryl group is 6 to 40, and the same applies to other substituents having a specified number of carbon atoms.

[0229] The term "unsubstituted" in the case of "substituted or unsubstituted" means that a hydrogen atom or a deuterium atom is substituted. The same also applies to the case of "substituted or unsubstituted" in the compounds or partial structures described below.

[0230] In the general formula (6), Z 1 and Z 2 are independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra) or a sulfur atom. 1 When Ra is NRa, Ra may be bonded to ring Za or ring Zb to form a ring. 2 In the case of NRa, Ra may be bonded to ring Za or ring Zc to form a ring.

[0231] E is a boron atom, a phosphorus atom, SiRa (silicon atom having a substituent Ra), or P═O.

[0232] In the general formula (7), E 1 and E 2 Each of them is independently BRa (boron atom with substituent Ra), PRa (phosphorus atom with substituent Ra), SiRa2 (silicon atom with two substituent Ra), P(=O)Ra2 (phosphine oxide with two substituent Ra) or P(=S)Ra2 (phosphine sulfide with two substituent Ra), S(=O) or S(=O)2. 1 When Ra is BRa, PRa, SiRa2, P(=O)Ra2 or P(=S)Ra2, Ra may be bonded to ring Za or ring Zb to form a ring. 2 In the case of BRa, PRa, SiRa2, P(=O)Ra2 or P(=S)Ra2, Ra may be bonded to ring Za or ring Zc to form a ring.

[0233] Ra are each independently substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, or substituted or unsubstituted alkyl.

[0234] Ra is preferably a group having 6 to 40 carbon atoms including substituents. Ra is more preferably a substituted or unsubstituted aryl group. Examples of the substituted or unsubstituted aryl group include substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl, etc., and more preferably a substituted or unsubstituted phenyl group.

[0235] Z 1 and Z 2 An oxygen atom or NRa is preferred. This is because the π-conjugated system of the compound represented by the general formula (6) is efficiently expanded, and reverse intersystem crossing from the triplet excited state to the singlet excited state occurs more efficiently, thereby further improving durability.

[0236] E is preferably a boron atom, 1 and E 2BRa is preferred. This is because the π-conjugated system of the compound represented by the general formula (6) is efficiently expanded, and reverse intersystem crossing from the triplet excited state to the singlet excited state occurs more efficiently, thereby further improving durability.

[0237] In all the above groups, hydrogen may be replaced by deuterium. The same applies to the compounds described below or their partial structures.

[0238] Among all the above groups, the substituents in the case of substitution are alkyl, cycloalkyl, heterocyclic, alkenyl, cycloalkenyl, alkynyl, aryl, heteroaryl, hydroxyl, thiol, alkoxy, alkylthio, aryl ether, aryl thioether, halogen, cyano, aldehyde, carbonyl, carboxyl, oxycarbonyl, amide, sulfonyl, sulfonate, sulfonamide, amino, nitro, silanyl, siloxane, boron or phosphine oxide. In addition, these substituents may be further substituted by the substituents described above.

[0239] The compound represented by the general formula (6) or the general formula (7) is a molecule that can separate the HOMO orbital from the LUMO orbital by the multiple resonance effect by preferably configuring the electron-donating amine nitrogen atom and the electron-accepting boron atom as described in the document "Adv. Mater., 2016, 28, 2777-2781. From the viewpoint of clearly separating the HOMO orbital from the LUMO orbital and bringing the singlet excited state and the triplet excited state closer to each other so as to easily emit delayed fluorescence, it is preferred that E is a boron atom with strong electron accepting properties and Z is 1 and Z 2 They are all groups with strong electron donating properties, namely, NRa.

[0240] In addition, the compound represented by the general formula (6) or the general formula (7) has a luminescence spectrum that is sharper than that formed by bonding the electron donor skeleton to the electron acceptor skeleton due to the multiple resonance effect, and luminescence with high color purity can be obtained. That is, the compound represented by the general formula (6) or the general formula (7) is conducive to improving the color gamut of the display, so it is preferred. In addition, with respect to the compound represented by the general formula (6) or the general formula (7), since ring Za, ring Zb, and ring Zc are mainly present around the E atom in the general formula (6) or the general formula (7) where the LUMO orbit is locally present, the LUMO orbit can be non-localized from the E atom to each ring. By making the LUMO orbit non-localized, the multiple resonance effect works efficiently, so luminescence with higher color purity can be obtained.

[0241] Furthermore, a structure in which Ra of the general formula (6) or the general formula (7) is bonded to at least one of the rings Za, Zb, and Zc is more preferred. This is because Ra is bonded to at least one of the rings Za, Zb, and Zc, so that E in the general formula (6) or E in the general formula (7)1 and E 2 The steric protection effect is further enhanced, and the effect of suppressing the decrease in fluorescence quantum yield can be expected to be further enhanced.

[0242] Examples of the compounds represented by the general formula (6) or (7) are shown below, but the compounds are not particularly limited thereto.

[0243] [Chemistry 18]

[0244]

[0245] <Binder Resin in Color Conversion Layer (A) and Color Conversion Layer (B)>

[0246] In the color conversion sheet of the present invention, the color conversion layer (A) and the color conversion layer (B) preferably contain a binder resin in addition to the luminescent material. As the binder resin, a material having excellent molding processability, transparency, heat resistance, etc. can be preferably used. Examples of binder resins include: acrylic acid series, methacrylic acid series, polyvinyl cinnamate series, cyclorubber series and other photocurable resist materials with reactive vinyl groups, epoxy resins, silicone resins (including organic polysiloxane hardeners (crosslinked products) such as silicone rubber and silicone gel), urea resins, fluororesins, polycarbonate resins, acrylic resins, urethane resins, melamine resins, polyethylene resins, polyamide resins, phenolic resins, polyvinyl alcohol resins, polyvinyl butyral resins, cellulose resins, aliphatic ester resins, aromatic ester resins, aliphatic polyolefin resins, aromatic polyolefin resins and other known binder resins. In addition, as the binder resin, a mixture or copolymer of these resins can also be used. For example, copolymers of methyl methacrylate and aliphatic polyolefin resins can be listed. By appropriately designing these resins, a binder resin useful for the color conversion sheet according to the embodiment of the present invention can be obtained.

[0247] Among these resins, any of a binder resin, an acrylic resin, a copolymer resin containing an acrylate or methacrylate moiety, a polyester resin, an aliphatic polyolefin resin, and copolymers thereof is preferred from the viewpoint of transparency and dispersibility of the organic light-emitting material.

[0248] <Other additives>

[0249] The color-changing sheet of the present invention may be added with fillers, antioxidants, processing and heat stabilizers, ultraviolet light absorbers and other light-resistant stabilizers, dispersants or leveling agents for stabilizing the coating film, plasticizers, cross-linking agents such as epoxy compounds, hardeners such as amine-anhydride-imidazole, pigments, and adhesion aids such as silane coupling agents as sheet surface modifiers, in addition to binder resins and luminescent materials.

[0250] As fillers, there can be cited fine particles such as fumed silica, glass powder, quartz powder, etc.; titanium oxide, zirconium oxide, barium titanate, zinc oxide, silicone fine particles, but there is no particular limitation. In addition, these fillers can be used alone or in combination of multiple types.

[0251] Examples of the antioxidant include phenolic antioxidants such as 2,6-di-tert-butyl-p-cresol and 2,6-di-tert-butyl-4-ethylphenol, but are not particularly limited. These antioxidants may be used alone or in combination of two or more.

[0252] As the processing and heat stabilizer, there can be cited phosphorus stabilizers such as tributyl phosphite, tricyclohexyl phosphite, triethylphosphine, diphenylbutylphosphine, etc., but there is no particular limitation. In addition, these stabilizers can be used alone or in combination of two or more.

[0253] Examples of the light resistance stabilizer include benzotriazoles such as 2-(5-methyl-2-hydroxyphenyl)benzotriazole and 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, but are not particularly limited. These light resistance stabilizers may be used alone or in combination of two or more.

[0254] The content of these additives in the color conversion sheet of the present invention also depends on the molar absorption coefficient, fluorescence quantum yield and absorption intensity at the excitation wavelength of the compound, as well as the thickness or transmittance of the prepared sheet, and is usually 1.0×10 -3 parts by mass or more and 30 parts by mass or less, more preferably 1.0×10 -2 Parts by mass or more and 15 parts by mass or less, particularly preferably 1.0×10 -1 Parts by mass or more and 10 parts by mass or less.

[0255] <solvent>

[0256] The color change sheet of the present invention may also contain a solvent. The solvent is not particularly limited as long as it can adjust the viscosity of the resin in a flowing state and does not excessively affect the luminescence and durability of the luminescent material. For example, water, 2-propanol, ethanol, toluene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, hexane, heptane, acetone, methyl acetate, ethyl acetate, butyl acetate, propyl acetate, isopropyl acetate, terpineol, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (Texanol), methyl cellosolve, ethyl cellosolve, butyl carbitol, butyl carbitol acetate, 1-methoxy-2-propanol, propylene glycol monomethyl ether acetate, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, etc., and these solvents can also be mixed and used in combination of two or more. Among these solvents, toluene and ethyl acetate are preferably used because they do not affect the deterioration of the compound represented by the general formula (1) and a small amount of residual solvent remains after drying.

[0257] <Method for producing color change sheet>

[0258] An example of a method for producing a color conversion sheet of the present invention is described below. In the method for producing a color conversion sheet, a composition for producing a color conversion layer is first produced as follows.

[0259] The luminescent material, binder resin, solvent, etc. are mixed in a prescribed amount. After the components are mixed in a prescribed composition, they are homogeneously mixed and dispersed using a homogenizer, a rotary-revolutionary mixer, a three-roll mill, a ball mill, a planetary ball mill, a bead mill, or other stirring / mixing machine to obtain a color-changing composition. After or during the mixing and dispersion, a degassing operation under vacuum or reduced pressure conditions may be preferably performed. In addition, a specific component may be mixed in advance or aging treatment may be performed. The solvent may also be removed by an evaporator to obtain a desired solid content concentration.

[0260] In the present invention, as a representative structural example of the color conversion sheet, the following can be cited: Figure 1 Furthermore, in order to prevent the color conversion layer from being degraded by oxygen, moisture or heat, it is also possible to Figure 3 As shown, a barrier layer 6 is further provided.

[0261] The thickness of the color change sheet is not particularly limited, but is preferably 1 μm to 5000 μm in total of all layers. A thickness of 1 μm or more can ensure sufficient film strength, and problems such as film breakage are less likely to occur. A sheet with excellent operability can be obtained by a thickness of 5000 μm or less. The thickness is more preferably 10 μm to 1000 μm, more preferably 15 μm to 500 μm, and particularly preferably 30 μm to 300 μm.

[0262] The film thickness of the color conversion sheet of the present invention refers to the film thickness (average film thickness) measured according to the thickness measurement method A method using mechanical scanning in Japanese Industrial Standards (JIS) K7130 (1999) Plastics - Films and sheets - Thickness measurement method.

[0263] <Base material layer>

[0264] As the substrate layer, known metals, films, glass, ceramics, paper, etc. can be used without particular limitation. Specifically, metal plates or foils of aluminum (including aluminum alloys), zinc, copper, iron, etc. can be listed; cellulose acetate, polyethylene terephthalate (PET), polyethylene, polyester, polyamide, polyimide, polyphenylene sulfide, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, polyaramid, silicone, polyolefin, thermoplastic fluororesin, copolymer of tetrafluoroethylene and ethylene (ethylene-tetrafluoroethylene, ETFE); plastic films including α-polyolefin resin, polycaprolactone resin, acrylic resin, silicone resin, and copolymerized resins of these resins and ethylene; paper laminated with the above plastic film, or paper coated with the above plastic, paper laminated or vapor-deposited with the above metal, plastic film laminated or vapor-deposited with the above metal, etc. In addition, when the substrate is a metal plate, the surface may be subjected to chromium-based or nickel-based plating treatment or ceramic treatment.

[0265] Among these, glass or resin films can be preferably used in terms of the ease of making the color change sheet or the ease of forming the color change sheet. In addition, a film with high strength is preferred so that there is no worry about breakage when handling the film-like substrate. In terms of these required characteristics or economy, a resin film is preferred. Among these, in terms of economy and operability, a plastic film selected from the group consisting of PET, polyphenylene sulfide, polycarbonate, and polypropylene is preferred. In addition, when the color change sheet is dried or the color change sheet is crimped and formed by an extruder at a high temperature of more than 200°C, a polyimide film is preferred in terms of heat resistance. In terms of the ease of peeling the sheet, the surface of the substrate layer may also be pre-treated for demolding.

[0266] The thickness of the substrate layer is not particularly limited, but the lower limit is preferably 5 μm or more, more preferably 25 μm or more, and further preferably 38 μm or more, and the upper limit is preferably 5000 μm or less, and more preferably 3000 μm or less.

[0267] <Color Transformation Layer>

[0268] Next, an example of a method for producing the color conversion layer included in the color conversion sheet of the present invention is described. The color conversion composition produced by the above method is applied to a substrate and dried. The coating can be performed by a reverse roll coater, a blade coater, a slot die coater, a direct gravure coater, an offset gravure coater, a kiss coater, a natural roll coater, an air knife coater, a roll blade coater, a two-stream coater, a rod coater, a wire bar coater, an applicator, a dip coater, a curtain coater, a spin coater, a knife coater, etc. In order to obtain uniform film thickness of the color conversion layer, it is preferred to perform coating by a slot die coater or a dip coater.

[0269] The color conversion layer can be dried using a general heating device such as a hot air dryer or an infrared dryer. In this case, the heating conditions are usually 40°C to 250°C for 1 minute to 5 hours, preferably 60°C to 200°C for 2 minutes to 4 hours. In addition, step-curing or other step-by-step heat curing can also be performed.

[0270] After the color change sheet is made, the substrate may be changed as needed. In this case, simple methods include a method of re-laminating using a hot plate, or a method of using a vacuum laminator or a dry film laminator, but are not limited to these methods.

[0271] The thickness of the color conversion layer is not particularly limited, but is preferably 1 μm to 1000 μm, and more preferably 10 μm to 1000 μm. A thickness of 1 μm or more can ensure sufficient film strength, and problems such as film breakage are less likely to occur. A thickness of 5000 μm or less can provide a sheet with excellent operability. The thickness is more preferably 10 μm to 100 μm, further preferably 15 μm to 100 μm, and particularly preferably 30 μm to 100 μm.

[0272] <Barrier layer>

[0273] The barrier layer can be used appropriately when the color conversion layer is given a gas barrier property. As the barrier layer, specifically, inorganic oxides such as silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, tin oxide, indium oxide, yttrium oxide, and magnesium oxide, or inorganic nitrides such as silicon nitride, aluminum nitride, titanium nitride, and silicon carbonitride, or mixtures thereof or metal oxide films or metal nitride films to which other elements are added to these substances; or films containing various resins such as polyvinylidene chloride, acrylic resin, silicone resin, melamine resin, urethane resin, fluorine resin, and polyvinyl alcohol resins such as saponified products of vinyl acetate. In addition, as a film having a barrier function against moisture, for example, films containing various resins such as polyethylene, polypropylene, nylon, polyvinylidene chloride, copolymers of vinyl chloride and vinyl chloride, copolymers of vinyl chloride and acrylonitrile, fluorine resins, and polyvinyl alcohol resins such as saponified products of vinyl acetate can be listed.

[0274] The barrier layer may be provided on both sides of the color conversion layer, or may be provided on only one side.

[0275] In addition, according to the functions required by the color change sheet, an auxiliary layer with functions such as light extraction function, anti-reflection function, anti-glare function, anti-reflection and anti-glare function, hard coating function (friction resistance function), anti-static function, anti-fouling function, electromagnetic wave shielding function, infrared cutting function, ultraviolet cutting function, polarization function, and color adjustment function can be further provided.

[0276] <Excitation light>

[0277] Any type of light source for the excitation light can be used as long as it is a light source that emits light in a wavelength region that can be absorbed by the luminescent material. For example, any light source such as a hot cathode tube or a cold cathode tube, an inorganic EL or other fluorescent light source, an organic electroluminescent element light source, an LED light source, an incandescent light source, etc. can be used in principle, among which LED is a preferred light source. In a display or lighting device, a blue LED having an excitation light in the wavelength range of 400nm to 500nm is a further preferred light source in terms of improving the color purity of blue light. If the wavelength range of the excitation light is located on the longer wavelength side than that, blue light is lacking, so white light cannot be formed. In addition, if the wavelength range of the excitation light is located on the shorter wavelength side than that, organic compounds such as luminescent materials or resins are prone to photodegradation, so it is not preferred.

[0278] The excitation light may have one luminescence peak or two or more luminescence peaks. In order to improve color purity, it is preferably one luminescence peak. In addition, multiple excitation light sources with different types of luminescence peaks may be used in any combination.

[0279] A color conversion sheet according to another embodiment of the present invention is a color conversion sheet, wherein the color conversion sheet is a color conversion sheet that converts incident light into light of a wavelength different from that of the incident light, wherein the color conversion sheet at least sequentially comprises a color conversion layer, a resin layer, and a substrate, wherein the color conversion layer comprises a luminescent material (a) that emits light with a peak wavelength observed in a region of 500 nm or more and less than 580 nm, and a luminescent material (b) that emits light with a peak wavelength observed in a region of 580 nm or more and less than 750 nm, and wherein the haze value of the color conversion sheet is 20% or more and 90% or less, and when the refractive index of the color conversion layer is set to n A , the refractive index of the resin layer is set to n B , and the refractive index of the substrate is set to n C When n A >n B And n B <n C . will be n A >n B And n B <n C The resin layer is also called a low-refractive layer.

[0280] The structure of the color conversion sheet of the above embodiment is shown in FIG. Figure 4 The color conversion sheet 5 includes a substrate layer 1, on which a color conversion layer 7 and a resin layer 3 are stacked. The color conversion sheet 5 may also have a structure in which the substrate layer 1 is further arranged on the resin layer 3 and the color conversion layer 7 and the resin layer 3 are sandwiched by the substrate layer 1. The resin layer 3 is preferably arranged at a position opposite to the light source side when viewed from the color conversion layer 7. Furthermore, when the refractive index of the color conversion layer is set to n A , the refractive index of the resin layer is set to n B , let the refractive index of the substrate be n C When h A >n B And n B <n C By having a resin layer at the above position, light emitted from the light source side is reflected at the interface between the color conversion layer and the resin layer, so that light leakage outside each layer can be suppressed, thereby further improving the color conversion efficiency and achieving good durability.

[0281] The color conversion layer 7 of the embodiment contains both a luminescent material (a) that emits light with a peak wavelength observed in a region of 500 nm or more and less than 580 nm and a luminescent material (b) that emits light with a peak wavelength observed in a region of 580 nm or more and 750 nm or less. The color conversion layer 7 preferably contains a binder resin in addition to the luminescent material. In addition, the color conversion layer 7 may also contain scattering particles in order to control the haze value.

[0282] The haze value, scattering particles, resin layer, luminescent material, binder resin, base material layer, barrier layer, and manufacturing method of the color conversion sheet are the same as those in the above-described embodiment.

[0283] <Light source unit>

[0284] The light source unit of the present invention contains at least a light source and a color conversion sheet. In the light source unit of the present invention, it is preferably arranged in the order of light source, color conversion layer (B), resin layer, and color conversion layer (A). In addition to the light source and the color conversion sheet, the light source unit may also contain other optical sheets. Examples of optical sheets include prism sheets, polarized reflective films, and diffusers. Representative examples include the following structures: Figure 5 As shown in the figure, the substrate 8, the reflective layer 9, and the light source 10 are stacked, and the color conversion sheet 5 of the present invention is arranged between the diffuser 11 and the prism sheet 12, and the polarized reflective film 13 is arranged on the surface of the prism sheet 12 opposite to the light source. From the viewpoint of thin filmization, productivity, and light durability, the optical sheet contained above the color conversion sheet of the present invention is preferably two or less. Here, the so-called "above the color conversion sheet" refers to the side opposite to the light source relative to the color conversion sheet. By having two or less optical sheets, the reflection of light can be suppressed, so the number of excitations of the luminescent material can be reduced, thereby preventing the decrease in durability. Figure 5 The light source is a so-called direct-down type structure, but the configuration of the light source is not particularly limited. In the case where the light source unit contains a color conversion sheet, there is no particular limitation on the configuration method of the light source and the color conversion sheet, except for the structure in the above order. A structure that makes the light source and the color conversion sheet close to each other can be adopted, or a remote phosphor that separates the light source and the color conversion sheet can be adopted. In addition, in order to improve the color purity, a structure that also contains a color filter can also be adopted.

[0285] As described above, the excitation light in the range of 400nm to 500nm has relatively small excitation energy and can prevent the decomposition of the light-emitting material. Therefore, the light source is preferably a light-emitting diode having a maximum emission in the range of 400nm to 500nm.

[0286] The light source unit of the present invention can be used for displays, lighting devices, interior decoration, signs, billboards, etc. In particular, it can be preferably used for displays or lighting devices.

[0287] Example

[0288] Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.

[0289] <Measurement of Haze and Total Light Transmittance>

[0290] The haze and total light transmittance of the color conversion sheets, color conversion layers (A), and color conversion layers (B) prepared in Examples and Comparative Examples were measured using NDH7000 (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with ASTM D1003 (2013). The number of measurements was set to once each.

[0291] <Measurement of Refractive Index>

[0292] The refractive index of each layer (n A1 、n A2 、n B 、n C 、n D1 、n D2 ) is obtained by measuring the refractive index of the resin film formed by coating each layer of the composition for making on the PET film. On "Lumirror" U48 (manufactured by Toray Co., Ltd., thickness 50μm), the composition for making each layer is coated with a Baker type applicator in such a way that the average film thickness becomes 2μm, and the resin film for measurement is formed by heating at 100°C for 20 minutes and drying. The refractive index of the formed resin film to light of wavelength 589.3nm is measured using a reflection spectrometer FE-3000 (manufactured by Otsuka Electronics Co., Ltd.).

[0293] <Measurement of Color Conversion Characteristics>

[0294] On a light-emitting device equipped with a blue LED (manufactured by USHIO EPITEX; model SMBB450H-1100, peak emission wavelength: 450nm), each color conversion sheet to be evaluated was set in the order of light source, color conversion layer (B), resin layer, and color conversion layer (A). A current of 100mA was passed through the light-emitting device to light the blue LED, and the emission spectrum, emission intensity at the peak wavelength, and chromaticity were measured using a spectroradiometer (CS-1000, manufactured by Konica Minolta). The distance between each color conversion sheet and the blue LED element was set to 3cm.

[0295] <Evaluation of In-Plane Uniformity>

[0296] The liquid crystal monitor (SW2700PT) manufactured by BenQ was disassembled, and the color conversion sheet produced in the following embodiments and comparative examples was inserted to replace the built-in color conversion sheet, and then assembled in the original state. The structure of the backlight unit at this time was "reflection film / light guide plate / diffusion sheet / color conversion sheet / prism sheet / polarized reflection film". The color coordinates u' and v' of 9 points were measured using a spectroradiometer (CS-1000, manufactured by Konica Minolta), and the in-plane deviation Δu'v' was calculated by the following formula.

[0297] Δu′=u′(max)-u′(min.)

[0298] Δv′=v′(max)-v′(min.)

[0299] Δu′v′={(Δu′) 2 +(Δv′) 2} 1 / 2

[0300] When Δu′v′ is 0.02 or less, the value is good, and when it is 0.015 or less, the value is extremely good.

[0301] <Light durability test>

[0302] On a light-emitting device equipped with a blue LED (manufactured by USHIO EPITEX; model SMBB450H-1100, peak emission wavelength: 450nm), each color conversion sheet to be evaluated was set in the order of light source, color conversion layer (B), resin layer, and color conversion layer (A). A current of 100mA was passed through the light-emitting device to light the blue LED, and the peak intensity at the wavelength of the color-converted emission was measured using a spectroradiometer (CS-1000, manufactured by Konica Minolta). In addition, the distance between each color conversion sheet and the blue LED element was set to 3cm. Thereafter, the light from the blue LED element was continuously irradiated in an environment of 50°C and 80%RH, and the time until the emission intensity of the phosphor decreased by 10% from the initial value was observed to evaluate the durability of the color conversion sheet. If the time until the emission intensity of the phosphor decreased by 10% from the initial value was 200 hours or more, it was good, and if it was 400 hours or more, it was extremely good.

[0303] <Luminescent Materials>

[0304] In the following Examples and Comparative Examples, Compound G-1, Compound G-3 and Compound R-1 are the compounds shown below.

[0305] [Chemistry 19]

[0306]

[0307] [Chemistry 20]

[0308]

[0309] Compound G-1 (peak emission wavelength: 515 nm) and compound G-3 (peak emission wavelength: 527 nm) were synthesized by a known method.

[0310] G-2: Quantum dots manufactured by SIGMA-ALDRICH (Product No. 776793) (peak emission wavelength: 560 nm) were used.

[0311] Compound R-1 (emission peak wavelength: 629.5 nm) was synthesized by a known method.

[0312] The scattering particles S-1, S-2, S-3, and S-4 are made of the following materials.

[0313] S-1: JR-301 (titanium dioxide particles manufactured by Tayca Co., Ltd., average particle size 300 nm)

[0314] S-2: AA-07 (alumina particles manufactured by Sumitomo Chemical Co., Ltd., average particle size 830 nm)

[0315] S-3: SO-E6 (silicon dioxide particles manufactured by Admatechs, Inc., average particle size 2000 μm)

[0316] S-4: KMP-706 (silicone resin particles manufactured by Shin-Etsu Chemical Co., Ltd., average particle size 2000 nm)

[0317] (Example 1)

[0318] After mixing 100 parts by weight of Olycox KC-7000, an acrylic resin manufactured by Kyoeisha Chemical Co., Ltd. as a resin, 0.4 parts by weight of G-1 as a luminescent material, 0.3 parts by weight of S-1 as scattering particles, and 300 parts by weight of toluene as a solvent, a planetary stirring / degassing device "Mazerustar" (registered trademark) KK-400 (manufactured by Kurabo Co., Ltd.) was used to stir / degas at 1000 rpm for 20 minutes to obtain a resin composition for preparing a color conversion layer (A).

[0319] Similarly, a silicone resin (KR-114B manufactured by Shin-Etsu Chemical Co., Ltd.) was used as a resin. After mixing 200 parts by weight of heptane as a solvent with respect to 100 parts by weight of the resin, a planetary stirring / degassing device "Mazerustar" (registered trademark) KK-400 (manufactured by Kurabo Co., Ltd.) was used to stir / degas at 300 rpm for 20 minutes to obtain a resin composition for making a resin layer.

[0320] Similarly, 100 parts by weight of the same resin as the resin liquid for preparing the color conversion layer (A), 0.08 parts by weight of compound R-1 as a luminescent material, 0.3 parts by weight of S-1 as scattering particles, and 200 parts by weight of toluene as a solvent were mixed, and then stirred / degassed at 300 rpm for 20 minutes using a planetary stirring / degassing device "Mazemstar" (registered trademark) KK-400 (manufactured by Kurabo Co., Ltd.) to obtain a resin composition for preparing the color conversion layer (B).

[0321] Next, the resin composition for preparing the color conversion layer (A) was applied onto a substrate of "Lumirror" (registered trademark) U48 (manufactured by Toray Industries, Ltd., thickness 50 μm) using a slot die coater, and heated at 120° C. for 20 minutes and dried to form a color conversion layer (A) having an average film thickness of 18 μm.

[0322] Similarly, the resin composition for forming a resin layer was applied onto the color conversion layer (A) using a slot die coater, and dried by heating at 120° C. for 20 minutes to form a resin layer having an average film thickness of 10 μm.

[0323] Similarly, a resin composition for preparing a color conversion layer (B) was applied onto a substrate of "Lumirror" (registered trademark) U48 (manufactured by Toray Industries, Ltd., thickness 50 μm) using a slot die coater, and heated at 120° C. for 20 minutes and dried to form a color conversion layer (B) having an average film thickness of 18 μm.

[0324] Next, the two units are laminated under heat so that the resin layer and the color conversion layer (B) are in direct contact with each other, thereby producing a color conversion sheet having a structure of "substrate / color conversion layer (A) / resin layer / color conversion layer (B) / substrate".

[0325] The refractive index of each layer was measured by the above-mentioned method using the produced color conversion sheet.

[0326] (Example 2 to Example 8, Example 17, Example 18, Comparative Example 1 to Comparative Example 3)

[0327] A color change sheet was prepared and evaluated by the same operation as in Example 1 except that the composition was changed as shown in Tables 1 and 2. In Example 17, the resin of the resin layer was changed to polyester "Vylon" (registered trademark) 270 manufactured by Toyobo Co., Ltd. In Comparative Example 3, the resin of the resin layer was changed to acrylic resin Olycox KC-7000 manufactured by Kyoeisha Chemical Co., Ltd. The results are shown in Tables 1 and 2.

[0328] According to the comparison between Example 1 and Comparative Example 1, the in-plane uniformity of Example 1 having a haze value of 20% or more is much better than that of Comparative Example 1 having a haze value of less than 20%.

[0329] In addition, from the comparison of Examples 1 to 5, it can be seen that the larger the haze value, the better the in-plane uniformity becomes. Among them, as shown in Comparative Example 2, when the haze value exceeds 90%, it can be seen that although the in-plane uniformity is good, the light durability is greatly reduced. Examples 3, 4, and 8 are particularly good in both in-plane uniformity and durability.

[0330] From the comparison between Example 7 and Example 4, it can be seen that as the light-emitting material of the color conversion layer (A), G-1 has better light durability than G-2.

[0331] From the comparison between Example 18 and Example 4, it can be seen that G-1 and G-3 have the same light durability as the light-emitting materials of the color conversion layer (A).

[0332] According to the comparison between Example 17 and Example 4, it can be seen that B Less than the refractive index n of the color conversion layer (A) A1 and the refractive index n of the color conversion layer (B) A2 Compared with the case of B Greater than the refractive index n of the color conversion layer (A) A1 and the refractive index n of the color conversion layer (B) A2 In this case, the light durability decreases.

[0333] According to the comparison between Example 17 and Comparative Example 3, it can be seen that the refractive index n of the resin layer B Greater than the refractive index n of the color conversion layer (A) A1 and the refractive index n of the color conversion layer (B) A2 Compared with the case of B The refractive index n of the color conversion layer (A) A1 and the refractive index n of the color conversion layer (B) A2 In the same case, light durability decreases.

[0334]

[0335] [Table 2]

[0336]

[0337] <Calculation of Color Gamut Area Ratio>

[0338] The liquid crystal monitor (SW2700PT) manufactured by BenQ was disassembled, and the color conversion sheet produced in the embodiment described later was inserted to replace the built-in color conversion sheet, and then assembled according to the original state. The structure of the backlight unit at this time is "reflection film / light guide plate / diffusion sheet / color conversion sheet / prism sheet / polarized reflection film". The color coordinates of each color in the (X, Y) color space when the blue, green, and red monochrome are displayed in the obtained monitor are measured using a spectroradiometer (CS-1000, manufactured by Konica Minolta). The area of ​​the color gamut is calculated based on the color coordinates of the three points obtained, and the area ratio of the DCI-P3 specification to the color gamut area is calculated. If the area ratio is 100% or more, it is good, and if it is 105% or more, it is extremely good.

[0339] <Relative brightness>

[0340] The brightness of the white light after the color conversion of Example 3 was set as 100, and the brightness of the Examples described below was compared. The relative brightness (%) is the relative brightness based on Example 3.

[0341] (Example 9)

[0342] A color conversion sheet was prepared by the same operation as in Example 3, except that the scattering particles in the color conversion layer (A) were 1.3 parts by weight and no scattering particles were added to the color conversion layer (B). The color conversion sheet was used to measure the color characteristics by the method described above. The result was that the green emission peak was 527nm and the red emission peak was 637nm. The color gamut area ratio was calculated by the method described above and the result was 105%. In addition, the relative brightness was calculated by the method described above and the result was 97%. The haze value and the refractive index of each layer were measured by the method described above. The results are shown in Table 3.

[0343] (Example 10)

[0344] A color conversion sheet was prepared by the same operation as in Example 3, except that the scattering particles in the color conversion layer (A) were 2 parts by weight and no scattering particles were added to the color conversion layer (B). The color conversion sheet was used to measure the color characteristics by the method described above. The result was that the green emission peak was 525 nm and the red emission peak was 639 nm. The color gamut area ratio was calculated by the method described above, and the result was 108%. In addition, the relative brightness was calculated by the method described above, and the result was 93%. The haze value and the refractive index of each layer were measured by the method described above. The results are shown in Table 3.

[0345] (Example 11)

[0346] A color conversion sheet was prepared by the same operation as in Example 3, except that no scattering particles were added to the color conversion layer (A) and the scattering particles in the color conversion layer (B) were set to 1.3 parts by weight. The color conversion sheet prepared was used to measure the color characteristics by the method described above. As a result, the green emission peak was 532nm, and the red emission peak was 634nm. The color gamut area ratio was calculated by the method described above, and the result was 98%. In addition, the relative brightness was calculated by the method described above, and the result was 108%. The haze value and the refractive index of each layer were measured by the method described above. The results are shown in Table 3.

[0347] (Example 12)

[0348] A color conversion sheet was prepared by the same operation as in Example 3, except that no scattering particles were added to the color conversion layer (A) and the scattering particles in the color conversion layer (B) were set to 2 parts by weight. The color conversion sheet prepared was used to measure the color characteristics by the method described above. As a result, the green emission peak was 534nm, and the red emission peak was 632nm. The color gamut area ratio was calculated by the method described above, and the result was 95%. In addition, the relative brightness was calculated by the method described above, and the result was 110%. The haze value and the refractive index of each layer were measured by the method described above. The results are shown in Table 3.

[0349] Comparison between Examples 9 and 10 and Examples 11 and 12 shows that the color gamut area is improved compared to the case where only the color conversion layer (A) contains scattering particles or the case where only the color conversion layer (B) contains scattering particles.

[0350] In addition, according to the comparison between Examples 11 and 12 and Examples 3, 9 and 10, it can be seen that the brightness is improved compared with the case where only the color conversion layer (B) contains scattering particles, the case where both the color conversion layer (A) and the color conversion layer (B) contain scattering particles, or the case where only the color conversion layer (A) contains scattering particles.

[0351] (Comparative Example 7)

[0352] A color conversion sheet was prepared by the same operation as in Example 3, except that the scattering particles in the color conversion layer (A) were 8 parts by weight and no scattering particles were added to the color conversion layer (B). The color conversion sheet was used to measure the color characteristics by the method described above. The result was that the green emission peak was 523 nm and the red emission peak was 641 nm. The color gamut area ratio was calculated by the method described above and the result was 108%. In addition, the relative brightness was calculated by the method described above and the result was 85%. The haze value and the refractive index of each layer were measured by the method described above. The results are shown in Table 3.

[0353] (Comparative Example 8)

[0354] A color conversion sheet was prepared by the same operation as in Example 3, except that no scattering particles were added to the color conversion layer (A) and the scattering particles in the color conversion layer (B) were set to 8 parts by weight. The color conversion sheet prepared was used to measure the color characteristics by the method described above. The result was that the green luminescence peak was 536nm and the red luminescence peak was 630nm. The color gamut area ratio was calculated by the method described above, and the result was 94%. In addition, the relative brightness was calculated by the method described above, and the result was 100%. The haze value and the refractive index of each layer were measured by the method described above. The results are shown in Table 3.

[0355] According to the comparison between Examples 9 and 10 and Comparative Example 7, and the comparison between Examples 11 and 12 and Comparative Example 8, it can be seen that when the content of particles is too high and the haze exceeds 90%, the brightness decreases significantly.

[0356] [Table 3]

[0357]

[0358] (Example 13)

[0359] 100 parts by weight of Olycox KC-7000, an acrylic resin manufactured by Kyoeisha Chemical Co., Ltd. as a resin, 0.4 parts by weight of G-1 as a luminescent material (a), 0.01 parts by weight of R-1 as a luminescent material (b), 0.6 parts by weight of S-1 as scattering particles, and 300 parts by weight of toluene as a solvent were mixed, and then stirred / degassed at 1000 rpm for 20 minutes using a planetary stirring / degassing device "Mazerustar" (registered trademark) KK-400 (manufactured by Kurabo Co., Ltd.) to obtain a resin composition for preparing a color conversion layer.

[0360] In the same manner as in Example 1, a resin liquid composition for forming a resin layer was obtained.

[0361] Next, the resin composition for preparing the color conversion layer was applied onto a substrate of "Lumirror" (registered trademark) U48 (manufactured by Toray Industries, Ltd., thickness 50 μm) using a slot die coater, and heated at 120° C. for 20 minutes and dried to form a color conversion layer with an average film thickness of 18 μm.

[0362] In the same manner as in Example 1, a resin layer having an average film thickness of 10 μm was formed on the color conversion layer.

[0363] Next, a color conversion sheet having a structure of "substrate / color conversion layer / resin layer / substrate" was prepared by laminating "Lumirror" (registered trademark) U48 (manufactured by Toray Industries, Ltd., thickness 50 μm) on the resin layer under heating.

[0364] The refractive index of each layer was measured by the above-mentioned method using the produced color conversion sheet. The results are shown in Table 4.

[0365] (Example 14 to Example 16, Comparative Example 4 to Comparative Example 6)

[0366] A color change sheet was prepared and evaluated by the same operation as in Example 13 except that the composition was changed as shown in Table 4. In Comparative Example 6, the resin of the resin layer was changed to polyester "Vylon" (registered trademark) 270 manufactured by Toyobo Co., Ltd. The results are shown in Table 4.

[0367] According to the comparison between Example 13 and Comparative Example 4, the in-plane uniformity of Example 13 having a haze value of 20% or more is significantly improved compared with Comparative Example 4 having a haze value of less than 20%.

[0368] In addition, from the comparison of Examples 13 to 16, it can be seen that the larger the haze value, the better the in-plane uniformity becomes. Among them, as shown in Comparative Example 5, when the haze value exceeds 90%, it can be seen that although the in-plane uniformity is good, the light durability is greatly reduced. Examples 14 and 15 are particularly good in both in-plane uniformity and durability.

[0369] According to the comparison between Comparative Example 6 and Example 15, it can be seen that the refractive index n of the resin layer B The refractive index n of the color conversion layer A and the refractive index n of the substrate layer C When the optical durability is the same or larger than them, the optical durability is greatly reduced.

[0370]

[0371] (Example 19 to Example 21)

[0372] A color conversion sheet was prepared and evaluated by the same operation as in Example 11 except that the composition was changed as shown in Table 5. The scattering particles in Examples 19, 20, and 21 were changed to S-2, S-3, and S-4, respectively. The results are shown in Table 5.

[0373] According to the comparison between Example 11 and Examples 19 to 21, it can be seen that the refractive index n of the color conversion layer is A2 and the refractive index n of the scattering particles D2 When the absolute value of the difference is within the above range, the total light transmittance is improved, and a color conversion sheet with higher brightness can be obtained.

[0374] [Table 5]

[0375]

Claims

1. A color conversion sheet that converts incident light into light with a wavelength different from that of the incident light, The color conversion sheet at least comprises a color conversion layer A, a color conversion layer B, a resin layer and a substrate. The color change sheets are directly adjacent to each other in the order of color change layer A, resin layer, and color change layer B. The color conversion layer A contains a luminescent material a which emits light with a peak wavelength observed in a region of 500 nm to less than 580 nm. The color conversion layer B contains a luminescent material b that emits light with a peak wavelength observed in a region of 580 nm to 750 nm. The color change sheet has a haze value of 20% or more and 90% or less, When the refractive index of the color conversion layer A is set to n A1 , set the refractive index of the color conversion layer B to n A2 , and the refractive index of the resin layer is set to n B When n A1 、n A2 and n B Satisfies the following relationship (1) or (2): (1)n A1 >n B And n A2 >n B (2)n A1 <n B And n A2 <n B .

2. The color conversion sheet according to claim 1, wherein the n A1 、n A2 and n B The relationship (1) is satisfied.

3. The color conversion sheet according to claim 1 or 2, wherein the n A1 、n A2 and n B Satisfy 0.15≧n A1 -n B ≧0.05 and 0.15≧n A2 -n B The relationship is ≧0.

05.

4. The color conversion sheet according to claim 1, wherein the n A1 、n A2 and n B Satisfy 0.15≧n B -n A1 ≧0.05 and 0.15≧n B -n A2 The relationship is ≧0.

05. 5 . The color conversion sheet according to claim 1 , wherein a haze value of the color conversion sheet is 50% or more and 75% or less. 6 . The color conversion sheet according to claim 1 , wherein either or both of the light-emitting material a and the light-emitting material b are organic light-emitting materials.

7. The color conversion sheet according to claim 6, wherein the organic light emitting material contains a compound represented by the general formula (1); X is CR 7 or N; R 1 ~R 9 They may be the same or different and are selected from hydrogen, alkyl, cycloalkyl, heterocyclic, alkenyl, cycloalkenyl, alkynyl, hydroxyl, thiol, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, halogen, cyano, aldehyde, carbonyl, carboxyl, oxycarbonyl, carbamoyl, amino, nitro, silanyl, siloxane, boronyl, phosphine oxide, and condensed rings and aliphatic rings formed with adjacent substituents.

8. The color conversion sheet according to claim 1, wherein one or both of the color conversion layer A and the color conversion layer B contain scattering particles, and when the haze of the color conversion layer A is set to H A The haze of the color conversion layer B is set to H B hour, |H A -H B |≧20%。 9 . The color conversion sheet according to claim 1 , wherein scattering particles are contained in either or both of the color conversion layer A and the color conversion layer B. 10 . The color conversion sheet according to claim 9 , wherein a content of scattering particles in the color conversion layer A is greater than a content of scattering particles in the color conversion layer B. 11 . The color conversion sheet according to claim 9 , wherein the content of the scattering particles in the color conversion layer B is greater than the content of the scattering particles in the color conversion layer A.

12. The color conversion sheet according to claim 9 or 10, wherein the scattering particles contain titanium dioxide.

13. The color conversion sheet according to claim 9 or 10, wherein the average particle diameter of the scattering particles is 100 nm to 500 nm.

14. The color conversion sheet according to claim 9 or 10, wherein the scattering particles include particles selected from alumina particles, silica particles and silicone resin particles, and when the refractive index of the color conversion layer A is set to n A1 , set the refractive index of the color conversion layer B to n A2 , the refractive index of the scattering particles contained in the color conversion layer A is set to n D1 , and the refractive index of the scattering particles contained in the color conversion layer B is set to n D2 When n A1 、n A2 、n D1 and n D2 Satisfy 0.03≦|n A1 -n D1 |≦0.3 and / or 0.03≦|n A2 -n D2 |≦0.

3.

15. The color conversion sheet according to any one of claims 1, 2, 4, 9 and 10, wherein the resin layer contains a silicone resin.

16. A light source unit comprising a light source and the color conversion sheet according to any one of claims 1 to 15. 17 . The light source unit according to claim 16 , wherein the light source is a light emitting diode having a maximum light emission in a range of 400 nm to 500 nm.

18. The light source unit according to claim 16 or 17, further comprising an optical sheet other than the color conversion sheet. 19 . The light source unit according to claim 18 , wherein the number of optical sheets included above the color conversion sheet is two or less.

20. A display comprising the light source unit according to any one of claims 16 to 19.

21. A lighting device comprising the light source unit according to any one of claims 16 to 19.

Images