Quantum dot, quantum dot-containing sheet and manufacturing method thereof, and backlight device or display device

Abstract

The purpose of the present invention is to provide: a quantum dot capable of obtaining a sheet having a quantum dot layer thickness of 50 [mu] m or less and excellent durability over time from the edge of the sheet; a quantum dot-containing sheet using the quantum dot; and a backlight device or a display device. The quantum dot according to the present invention is characterized in that the quantum dot does not contain a RoHS-limiting substance and has a higher absorption coefficient at 450 nm than that of InP. According to the present invention, the quantum dot preferably comprises a core composed of the I-III-VI type chalcopyrite system. Preferably, the group I contains at least one of Ag and Cu, the group III contains at least one of Ga and In, and the group VI contains at least one of S, Se, and Te. The quantum dot-containing sheet according to the present invention is a quantum dot-containing sheet obtained by curing a quantum dot-containing composition containing the quantum dots according to the present invention, and is characterized in that the quantum dot layer thickness is 50 [mu] m or less. It is preferable that the deterioration from the end of the sheet is 500 [mu] m or less.

Description

Technical Field

[0001] This invention relates to quantum dots, quantum dot sheets, methods for manufacturing the same, and backlighting devices or display devices. Background Technology

[0002] To suppress the deterioration of the ends of sheets containing quantum dots, it largely depends on the structure of the quantum dots or the resin in which the quantum dots are dispersed.

[0003] The patent documents described below focus on resins used in resin compositions containing quantum dots, structures of laminated films, etc., with the aim of improving durability.

[0004] However, quantum dots that can suppress degradation from the ends of the sheet while reducing the sheet thickness have not been specifically disclosed.

[0005] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2016-511709 Patent Document 2: Japanese Patent No. 5940079 Patent Document 3: International Publication No. 2018 / 056469 Patent Document 4: Korean Patent No. 10-1969561 Patent Document 5: Japanese Patent Application Publication No. 2017-032918 Patent Document 6: Japanese Patent Application Publication No. 2019-086555 Patent Document 7: Japanese Patent Application Publication No. 2018-124412 Patent Document 8: Japanese Patent Application Publication No. 2017-214486 Summary of the Invention

[0006] The problem that the invention aims to solve The present invention was made in view of the above-mentioned situation, and its object is to provide a quantum dot that can produce a sheet with a quantum dot layer thickness of less than 50 μm and excellent durability over time from the edge of the sheet, a quantum dot sheet using the quantum dot, a method for manufacturing the same, and a backlight device or display device.

[0007] Methods for solving problems The quantum dots of the present invention are characterized by being free of RoHS-restricted substances and having a higher absorption coefficient at 450 nm compared to InP.

[0008] Invention Effects By using the quantum dots of the present invention, it is possible to obtain a sheet with a quantum dot layer thickness of less than 50 μm and excellent durability over time from the edge of the sheet. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of quantum dots.

[0010] Figure 2 This is a longitudinal sectional view of the content sub-dot sheet according to the first embodiment of the present invention.

[0011] Figure 3 This is a longitudinal sectional view showing the content sub-dot sheet according to the second embodiment of the present invention.

[0012] Figure 4 This is a longitudinal sectional view of the content sub-dot sheet according to the third embodiment of the present invention.

[0013] Figure 5 This is a perspective view of the content-rich dot sheet of this embodiment.

[0014] Figure 6 This is a longitudinal sectional view of a display device using the content sub-dot sheet of this embodiment.

[0015] Figure 7 The content of the sub-dot sheet used in this embodiment is related to... Figure 6 Longitudinal sectional views of different display devices.

[0016] Figure 8 This is a longitudinal sectional view of a liquid crystal display element using the sub-dot sheet of this embodiment.

[0017] Figure 9 This is a cross-sectional view showing an example of the content sub-dot sheet of this embodiment.

[0018] Figure 10 This is a cross-sectional view illustrating an example of the manufacture of the content-rich sub-dot sheet according to this embodiment.

[0019] Figure 11A This is a cross-sectional view of a quantum dot sheet with a substrate film on both sides of the quantum dot layer.

[0020] Figure 11B It is Figure 11A The diagram shows a cross-sectional view of a quantum dot sheet with one side of the substrate film peeled off, and the substrate film content only present on one side of the quantum dot layer.

[0021] Figure 12 This is a schematic diagram showing a manufacturing apparatus for producing the content sub-dot sheet of this embodiment.

[0022] Figure 13A This is a graph showing the relationship between wavelength and absorption coefficient in chalcopyrite quantum dots of the embodiments and InP of the comparative examples.

[0023] Figure 13BThis is a graph showing the relationship between wavelength and absorption coefficient in chalcopyrite quantum dots of the embodiments and InP of the comparative examples.

[0024] Figure 13C The upper section shows the EDX mapping of Ag and Ga, and the lower section is a schematic diagram of a part of it.

[0025] Figure 13D The upper section shows the EDX mapping of Zn and S, and the lower section is a schematic diagram of a part of it.

[0026] Figure 14 It is a graph showing the relationship between wavelength (400nm~700nm) and brightness when using a direct-lit optical element with a partial reflective sheet and a direct-lit optical element without a partial reflective sheet.

[0027] Figure 15 It is a graph showing the relationship between wavelength (400nm~700nm) and brightness using a direct-lit optical element (with DBEF) having a partial reflective sheet and a direct-lit optical element (with DBEF) without a partial reflective sheet.

[0028] Figure 16 It is a graph showing the relationship between wavelength (500nm~700nm) and brightness when using a direct-lit optical element with a partial reflective sheet and a direct-lit optical element without a partial reflective sheet.

[0029] Figure 17 It is a graph showing the relationship between wavelength (500nm~700nm) and brightness using a direct-lit optical element (with DBEF) having a partial reflective sheet and a direct-lit optical element (with DBEF) without a partial reflective sheet.

[0030] Figure 18 It is a graph showing the relationship between wavelength (400nm~700nm) and brightness when using a direct-lit optical element with a partial reflective sheet and a direct-lit optical element without a partial reflective sheet.

[0031] Figure 19 It is a graph showing the relationship between wavelength (400nm~700nm) and brightness when using a direct-lit optical element with a partial reflective sheet and a direct-lit optical element without a partial reflective sheet.

[0032] Figure 20It is a graph showing the relationship between wavelength (500nm~700nm) and brightness when using a direct-lit optical element with a partial reflective sheet and a direct-lit optical element without a partial reflective sheet.

[0033] Figure 21 It is a graph showing the relationship between wavelength (500nm~700nm) and brightness when using a direct-lit optical element with a partial reflective sheet and a direct-lit optical element without a partial reflective sheet.

[0034] Figure 22 This is a schematic diagram of sample 7.

[0035] Figure 23 This is a schematic diagram of sample 8.

[0036] Figure 24 This is a schematic diagram of sample 9.

[0037] Figure 25 This is a schematic diagram of sample 10.

[0038] Figure 26 This is a schematic diagram of sample 11.

[0039] Figure 27 This is a schematic diagram of sample 12.

[0040] Figure 28A It is the emission spectrum of the backlight.

[0041] Figure 28B This is the emission spectrum of Example 1.

[0042] Figure 28C This is the emission spectrum of Example 2.

[0043] Figure 29 These are photographs and schematic diagrams illustrating the degradation mode of this embodiment.

[0044] Figure 30 This is a schematic diagram illustrating an application example of the content-rich sub-dot sheet in this embodiment. Detailed Implementation

[0045] The embodiments of the present invention will be described in detail below. However, the following description is only one example (representative example) of the embodiments described herein, and the present invention is not limited to these contents as long as it does not depart from its spirit. In addition, the expression "~" used below includes both the lower limit and the upper limit.

[0046] <Quantum dot> The quantum dots used in this embodiment are nanoparticles with a particle size of several nm to tens of nm, which are materials that absorb excitation light and emit light efficiently. The peak wavelength of the emitted light can be controlled by the composition or particle size of the nanoparticles. In display materials applications, quantum dots that emit red and green light are preferred. Depending on the situation, quantum dots that emit blue light are sometimes used, and in this embodiment, quantum dots with a suitable wavelength can also be used.

[0047] The quantum dots of this embodiment are characterized by being free of RoHS-restricted substances and having a higher absorption coefficient at 450 nm compared to InP. Thus, the quantum dots do not contain RoHS-restricted substances such as cadmium and lead. Furthermore, the quantum dots of this embodiment have a higher absorption coefficient at 450 nm compared to commercially available cadmium-free InP quantum dots.

[0048] The quantum dot in this embodiment has a core composed of type I-III-VI chalcopyrite.

[0049] That is, the core is Ag-Ga-S2 system, as a group I element, replacing Ag, or it can be Cu, or it can contain both Ag and Cu.

[0050] Alternatively, as a Group III element, In can replace Ga, or it can contain both Ga and In.

[0051] In addition, as a VI element, it can replace S with Se or Te, or it can contain S and Se, S and Te, Se and Te, or S, Se and Te.

[0052] In this embodiment, for example, quantum dots are made of AgIn x Ga 1-x S y Se 1-y System or ZnAgIn x Ga 1-x S y Se 1-y The quantum dots are composed of a series (0≤x<1, 0≤y≤1). In this embodiment, the quantum dots are preferably nanocrystals containing at least silver (Ag), gallium (Ga) and sulfur (S), or silver (Ag), gallium (Ga) and selenium (Se), and free of cadmium (Cd). Alternatively, the quantum dots may also contain Ag, Ga and S, or Ag, Ga and Se, and further contain indium (In) or zinc (Zn).

[0053] Here, "nanocrystals" refers to nanoparticles with a particle size of approximately several nm to tens of nm. In this embodiment, multiple quantum dots can be generated with a substantially uniform particle size.

[0054] The ratio of Ag to Ga in the quantum dot is preferably in the range of Ag / Ga = 0.05 or more and 10 or less. More preferably, the Ag / Ga ratio is in the range of 0.05 or more and 5 or less, and even more preferably, it is in the range of 0.1 or more and 3 or less.

[0055] The Zn to Ga ratio that can be included in the quantum dot is preferably in the range of Zn / Ga = 0.1 or more and 10 or less. More preferably, the Zn / Ga ratio is in the range of 0.1 or more and 5 or less. By controlling this ratio, the emission wavelength can be adjusted.

[0056] According to this embodiment, the fluorescence wavelength can be adjusted to the range from the green wavelength region to the red wavelength region. In particular, according to this embodiment, the fluorescence wavelength can be appropriately adjusted within the range of 400 nm or more and 700 nm or less. According to this embodiment, the fluorescence wavelength can also be adjusted within the range of 500 nm or more and 650 nm or less.

[0057] In this embodiment, the quantum dot forms a shell on the surface of the core, separated by a buffer layer. The buffer layer is a region in which at least some or all of the elements constituting the core are mixed with at least some or all of the elements constituting the shell.

[0058] The shell is preferably ZnS. Furthermore, it is preferable that the surface of the shell has ligands.

[0059] Figure 1 This is a schematic diagram of quantum dots. (Example) Figure 1 As shown, the quantum dot 5 has a core 5a, a shell 5b formed on its surface, and an organic ligand 6 disposed on the surface of the shell 5b.

[0060] In order to suppress the aggregation of quantum dot 5 and obtain excellent optical properties, it is preferable to have multiple organic ligands 6 coordinated on the surface of quantum dot 5.

[0061] The ligand used in this embodiment is not limited to the following ligands, but examples include oleylamine: C 18 H 35 NH2, stearyl (octadecyl)amine: C 18 H 37 NH2, dodecyl (lauryl)amine: C 12 H 25 NH2, decylamine: C 10 H 21 NH2, Octylamine: C8H 17 Aliphatic amine compounds such as NH2; fatty acids, oleic acid: C 17 H 33 COOH, stearic acid: C 17 H 35 COOH, palmitic acid: C15 H 31 COOH, myristic acid: C 13 H 27 COOH, lauryl (dodecanoic acid): C 11 H 23 COOH, Decanoic acid: C9H 19 COOH, Caprylic acid: C7H 15 Fatty acid compounds such as COOH; octadecylthiol: C 18 H 37 SH, hexadecylthiol: C 16 H 33 SH, tetradecylthiol: C 14 H 29 SH, dodecylthiol: C 12 H 25 SH, decanethiol: C 10 H 21 SH, Octanethiol: C8H 17 SH and other thiol compounds; trioctylphosphine: (C8H 17 3P, triphenylphosphine: (C6H5)3P, tributylphosphine: (C4H9)3P; phosphine oxide series, trioctylphosphine oxide: (C8H 17 Phosphine compounds such as 3P=O, triphenylphosphine oxide (C6H5)3P=O, and tributylphosphine oxide (C4H9)3P=O.

[0062] They can be used individually or in any combination of two or more.

[0063] Although Figure 1 It is not shown in the diagram, but a buffer layer is formed between the core 5a and the shell 5b. ZnS is preferred for the shell 5b, but ZnSe can also be used instead.

[0064] In this embodiment, the structure is a core / buffer layer (a layer in which the core and shell coexist) / shell. As an example of a buffer layer, it could be AgGaS2, (AgZnGa)S2, AgGaSe2, or (AgZnGa)Se2. Furthermore, in... Figure 1 In the diagram, the boundary between the core 5a and the shell 5b is shown by a dashed line, but this indicates that the boundary between the core 5a and the shell 5b may not be clearly identifiable through analysis. Although not illustrated, a buffer layer is present within the dashed area.

[0065] As the quantum dots used in this embodiment, it is preferable to use quantum dots that exhibit green light emission with a peak wavelength of 520 to 560 nm (hereinafter referred to as green quantum dots) and quantum dots that exhibit red light emission with a peak wavelength of 600 to 680 nm (hereinafter referred to as red quantum dots).

[0066] The quantum dot in this embodiment absorbs 450nm blue light, and its absorption coefficient is higher than that of InP.

[0067] In this embodiment, quantum dots with a fluorescence half-width (FWHM) of 40 nm or less, preferably 35 nm or less, and even more preferably 30 nm or less are preferred.

[0068] The amount of quantum dots contained in the composition described below is preferably 0.03% by mass or more and 2% by mass or less, and more preferably 0.05% by mass or more and 1% by mass or less, relative to 100% by mass of the sum of polyfunctional (meth)acrylate and polyfunctional thiol. When the amount of quantum dots is in the range of 0.03% to 2% by mass, sufficient luminescence intensity from the quantum dots can be obtained.

[0069] <Compositions containing sub-dots> In this embodiment, a composition containing the aforementioned quantum dots is generated. In addition to quantum dots, it further comprises polyfunctional (meth)acrylates, polyfunctional thiols, and a reaction retarder.

[0070] In this embodiment, by adjusting the composition, core-shell structure, and ligands of the quantum dots, and by appropriately adjusting the dispersion resin, thin sheets can be achieved, and edge deterioration of the sheets can be effectively suppressed. The substances contained in the quantum dot-containing composition will be described below.

[0071] (Polyfunctional (meth)acrylates) The polyfunctional (meth)acrylate has two or more (meth)acrylate groups per molecule. In this embodiment, a cured coating can be obtained by free radical polymerization of the polyfunctional (meth)acrylate and the polyfunctional thiol (described later) using a photopolymerization initiator. This cured film can significantly improve the durability of the quantum dots in this embodiment. Furthermore, it also functions as an adhesive for bonding two plastic films together when manufacturing quantum dot sheets.

[0072] The multifunctional monomers used in this embodiment are not limited to the following, but may include, for example, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tetrapropylene glycol diacrylate, polypropylene glycol diacrylate, neopentyl glycol diacrylate, neopentyl glycol PO modified diacrylate, and hydroxyl groups. Neopentyl pivalate diacrylate, caprolactone adduct diacrylate of hydroxypentyl pivalate neopentyl pivalate, 1,6-hexanediol bis(2-hydroxy-3-acryloyloxypropyl) ether, bis(4-acryloyloxypolyethoxyphenyl)propane, 1,9-nonanediol diacrylate, pentaerythritol diacrylate, pentaerythritol diacrylate monostearate, pentaerythritol diacrylate monobenzoate, bisphenol A diacrylate, EO-modified bisphenol A diacrylate, PO-modified bisphenol A diacrylate, bisphenol F-diacrylate, EO-modified bisphenol F-diacrylate, PO-modified bisphenol F-diacrylate, EO-modified tetrabromobisphenol A-diacrylate, tricyclodecane dimethylolpropoxide, isocyanuric acid EO-modified diacrylate, 2-hydroxy-1,3-disacryloyloxypropane and other difunctional acrylate monomers; glycerol PO-modified triacrylate, trimethylolpropane triacrylate, trimethylolpropane EO-modified triacrylate, trimethylolpropane PO-modified triacrylate, isocyanuric acid EO-modified triacrylate Acrylate monomers include trifunctional acrylate monomers such as esters, isocyanate-modified EO-modified ε-caprolactone triacrylates, 1,3,5-triacryloylhexahydro-s-triazine, pentaerythritol triacrylate, and dipentaerythritol triacrylate tripropionate; and acrylate monomers with four or more functions such as pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate monopropionate, dipentaerythritol hexaacrylate, tetramethylolmethane tetraacrylate, low-polyester tetraacrylate, and tri(acryloyloxy)phosphate. These monomers can be used alone or in any combination of two or more.

[0073] In this embodiment, the average number of functional groups per molecule of the polyfunctional (meth)acrylate is preferably 2 or more, more preferably 2.5 or more, and even more preferably 3 or more. With a functional group number of 2 or more, sufficient cross-linking can be obtained as the cured film, resulting in excellent durability.

[0074] (Polyfunctional thiols) The polyfunctional thiols used in this embodiment have two or more thiol groups per molecule. These polyfunctional thiols impart excellent oxygen barrier properties to the cured film, which is then coated with a polyfunctional (meth)acrylate.

[0075] The polyfunctional thiols used in this embodiment are not limited to the following, but may include, for example, ethylene glycol bis(3-mercaptopropionate), diethylene glycol bis(3-mercaptopropionate), tetraethylene glycol bis(3-mercaptopropionate), 1,2-propanediol bis(3-mercaptopropionate), diethylene glycol bis(3-mercaptobutyrate), 1,4-butanediol bis(3-mercaptopropionate), 1,4-butanediol bis(3-mercaptobutyrate), 1,8-octanediol bis(3-mercaptopropionate), 1,8-octanediol bis(3-mercaptobutyrate), hexanediol dimercaptoacetate, trimethylolpropane tri(3-mercaptopropionate), trimethylolpropane tri(3-mercaptobutyrate), trimethylolpropane tri(3-mercaptobutyrate), trimethylolpropane tri(3-mercaptopropionate), and trimethylolpropane tri(3-mercaptopropionate). 3-Mercaptoisobutyrate), trimethylolpropane trimercaptoacetate, tri-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, trimethylolethane tris(3-mercaptobutyrate), pentaerythritol tetra(3-mercaptopropionate), pentaerythritol tetra(3-mercaptobutyrate), pentaerythritol tetra(3-mercaptoisobutyrate), dipentaerythritol hexa(3-mercaptopropionate), dipentaerythritol hexa(3-mercaptobutyrate), dipentaerythritol hexa(3-mercaptoisobutyrate), pentaerythritol tetramercaptoacetate, dipentaerythritol hexamercaptoacetate, etc. These can be used alone or in any combination of two or more.

[0076] In this embodiment, the average number of functional groups per molecule of the polyfunctional thiol is preferably 2 or more, more preferably 2.5 or more, and even more preferably 3 or more. With a functional group number of 2 or more, sufficient cross-linking can be obtained as the cured film, resulting in excellent durability.

[0077] In this embodiment, the molar ratio of (meth)acrylate groups to mercapto groups in the polyfunctional (meth)acrylate (A) to the molar ratio of thiol groups in the polyfunctional thiol (molar number of acrylate groups / molar number of mercapto groups) is preferably in the range of 0.6 or more and 9.0 or less, more preferably in the range of 0.8 or more and 5.5 or less, and even more preferably in the range of 1.0 or more and 2.5 or less. When the molar ratio of mercapto groups to (meth)acrylate groups is in the range of 0.6 to 9.0, preferably in the range of 0.8 to 5.5, a film with high crosslinking density can be formed after the curing reaction, resulting in excellent durability. Alternatively, in this embodiment, the molar ratio of (meth)acrylate groups to mercapto groups in the polyfunctional (meth)acrylate to the molar ratio of thiol groups in the polyfunctional thiol (molar number of acrylate groups / molar number of mercapto groups) is preferably in the range of 1.52 or more and 9.0 or less.

[0078] (Reaction delay agent) The reaction delaying agent used in this embodiment is added to delay the reaction between the (meth)acrylate groups and the mercapto groups when mixing polyfunctional (meth)acrylates and polyfunctional thiols in order to obtain an excellent pot life.

[0079] The reaction delay agent used in this embodiment is not limited to the following, and examples include phenolic compounds, phosphite compounds, and dithiocarbamate compounds. From the viewpoint that an excellent pot life can be obtained with a small amount of formulation, at least one of a phosphite compound and a dithiocarbamate compound is preferred. The phenolic compound is not limited to the following, and examples include 4-methoxyphenol and hydroquinone. The phosphite compound is not limited to the following, and examples include dimethyl phosphite, diethyl phosphite, dibutyl phosphite, diisopropyl phosphite, diisobutyl phosphite, diphenyl phosphite, dibenzyl phosphite, bis(2,2,2-trifluoroethyl) phosphite, trimethyl phosphite, triethyl phosphite, triisopropyl phosphite, tributyl phosphite, trihexyl phosphite, triethylhexyl phosphite, trioctyl phosphite, triisodecyl phosphite, trilauryl phosphite, triphenyl phosphite, and tri-o-toluene phosphite. As dithiocarbamate compounds, they are not limited to the following, for example, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetraisopropylthiuram disulfide, tetrabutylthiuram disulfide, tetramethylthiuram monosulfide, tetrabispentamethylenethiuram tetrasulfide, etc. They can be used alone or in any combination of two or more.

[0080] In this embodiment, dithiocarbamate compounds are more preferably used as reaction delay agents.

[0081] Regarding the amount of the reaction retarder used in this embodiment, relative to 100% by mass of the sum of polyfunctional (meth)acrylate and polyfunctional thiol, the reaction retarder preferably contains 0.0005% by mass or more and 1% by mass or less, more preferably 0.0005% by mass or more and 0.5% by mass or less. When the amount is 0.0005% by mass or more, a sufficient reaction retardation effect can be obtained, resulting in a good pot life. In addition, when the amount is 0.5% by mass or less, curing hindrance can be suppressed during the curing reaction process when manufacturing the sub-dot sheet, resulting in excellent durability.

[0082] (Scattering agent) In this embodiment, a scattering agent may be further included. The scattering agent used in this embodiment enables the excitation light of the quantum dot to scatter, thereby extending the optical path length and effectively improving the luminescence intensity of the quantum dot.

[0083] Examples of scattering agents used in this embodiment include organic scattering agents, inorganic scattering agents, and mixed organic-inorganic scattering agents. The organic scattering agents used in this embodiment are not limited to the following; examples include resin particles such as polystyrene-based particles, polymethyl methacrylate-based particles, polyurethane-based particles, polyethylene-based particles, polypropylene-based particles, melamine-based particles, and benzoguanamine-based particles. These can be used alone or in any combination of two or more. Furthermore, they are typically obtained through heterogeneous polymerization such as suspension polymerization, and can be substances with internal cross-linking of particles or substances with functional groups such as acrylate groups on their surface.

[0084] The inorganic scattering agents used in this embodiment are not limited to the following, and may include silica particles such as colloidal silica, fumed silica, and settled silica; inorganic oxides such as alumina particles, zirconium oxide particles, titanium oxide particles, and zinc oxide particles; talc; mica; kaolin; and clay. These can be used alone or in any combination of two or more. Furthermore, the particle surface may be pretreated with a silane coupling agent or the like.

[0085] The organic-inorganic mixture used in this embodiment is not limited to the following, and examples include resin particles containing silica particles, resin particles containing titanium dioxide particles, and silica-modified resin particles. They can be used alone or in any combination of two or more.

[0086] Regarding the scattering agent used in this embodiment, from the viewpoint that it has high scattering efficiency due to its high refractive index and high quantum yield due to its high transparency, it is preferable to use particles having at least one of the structures of melamine and benzoguanidine.

[0087] Regarding the amount of scattering agent used in this embodiment, it is preferably in the range of 0.05% by mass or more and 10% by mass or less relative to 100% by mass of the sum of polyfunctional (meth)acrylate (A) and polyfunctional thiol, and more preferably in the range of 0.1% by mass or more and 8% by mass or less.

[0088] (Photopolymerization initiator) In this embodiment, a photopolymerization initiator is preferably further included. The photopolymerization initiator used in this embodiment is used to efficiently carry out the curing reaction based on the crosslinking of polyfunctional (meth)acrylates and polyfunctional thiols. During the curing reaction, active energy rays such as ultraviolet light or electron beams are preferably used, more preferably ultraviolet light. The wavelength and irradiation dose of the active energy rays can be appropriately set, for example, 100 mJ / cm². 2 ~5000mJ / cm 2Irradiation with ultraviolet light with wavelengths of 280–400 nm. Examples of well-known light sources for generating ultraviolet light include low-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, and xenon lamps. These can be used individually or in any combination of two or more.

[0089] As the photopolymerization initiator used in this embodiment, a known photopolymerization initiator can be used, such as diethoxyacetophenone, 2-hydroxy-1-phenylpropane-1-one, benzyl methyl ketal, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butane Alkane, oligomeric {2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]acetone}, 2-hydroxy-1-{4-(2-hydroxy-2-methylpropanoyl)benzyl}phenyl}-2-methylpropane-1-one and other acetophenones; benzoin, benzoin methyl ether, benzoin ethyl ether and other benzoin derivatives; phosphine derivatives such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; and methyl phenylglyoxylate, etc. They can be used alone or in any combination of two or more.

[0090] The amount of photopolymerization initiator used in this embodiment is preferably 0.05% by mass or more and 5% by mass or less, and more preferably 0.1% by mass or more and 4% by weight or less, relative to 100% by mass of the sum of polyfunctional (meth)acrylate and polyfunctional thiol.

[0091] In this embodiment, to further improve curability, a photosensitizer can be used in conjunction with a photopolymerization initiator. Known photosensitizers can be used, such as unsaturated ketones like chalcone derivatives and dibenzylidene acetone, 1,2-diones like benzoyl and camphorquinone, benzoin derivatives, fluorene derivatives, naphthoquinone derivatives, anthraquinone derivatives, xanthones, thioxanthones, xanthonone derivatives, thioxanthonone derivatives, coumarin derivatives, coumarinone derivatives, anthocyanin derivatives, oxacyanine derivatives, polymethyl pigments such as acridine derivatives, acridine derivatives, thiazide derivatives, and oxazine derivatives. Azide derivatives, indoline derivatives, azulene derivatives, azulonium derivatives, squaric acid lactonium derivatives, porphyrin derivatives, tetrapyrazine-porphyrinazine derivatives, phthalocyanine derivatives, tetraazaporphyrinazine derivatives, tetraquinoxaline-porphyrinazine derivatives, naphthylphthalocyanine derivatives, phthalocyanine derivatives, pyranium derivatives, thiopyranium derivatives, tetrahydronaphthalene derivatives, annulide derivatives, spiropyran derivatives, spiroxazine derivatives, thiospiropyran derivatives, metal aromatic hydrocarbon complexes, organorruthenium complexes, mifepristone derivatives, biimidazole derivatives, etc. These can be used alone or in any combination of two or more.

[0092] Regarding the amount of photosensitizer used in this embodiment, it is preferably in the range of 0.05% by mass or more and 5% by weight or less relative to 100% by mass of the sum of polyfunctional (meth)acrylate and polyfunctional thiol.

[0093] (Dispersion resin) In this embodiment, a dispersion resin is preferably further included. The dispersion resin used in this embodiment is used to improve the compatibility of quantum dots and scattering agents with polyfunctional (meth)acrylates and polyfunctional thiols. By improving compatibility, in-plane deviation of the brightness of the cured film composed of the quantum dot-containing composition can be suppressed, and the decrease in luminescence quantum yield caused by the aggregation of quantum dots can be suppressed.

[0094] The dispersion resin used in this embodiment is not limited to the following, and examples include acrylic resins, polyurethane resins, polyester resins, polyolefin resins, polycarbonate resins, polyethyleneimine resins, epoxy resins, and sulfide resins. In particular, from the viewpoint of excellent compatibility with polyfunctional (meth)acrylates and polyfunctional thiols, at least one selected from acrylic resins, polyurethane resins, polyester resins, and polyethyleneimine resins is preferred.

[0095] The acrylic resin used in this embodiment is obtained by polymerizing monomers having unsaturated groups such as (meth)acrylate, vinyl, and allyl groups using known polymerization methods such as free radical polymerization, living free radical polymerization, anionic polymerization, and cationic polymerization.

[0096] The urethane resin used in this embodiment is obtained by urethane esterification of polyols with polyisocyanates using a known method.

[0097] The polyester resin used in this embodiment can be obtained by esterifying polyacids and polyols using known methods, or by ring-opening polymerization of cyclic ester compounds such as caprolactone and butyrolactone using known methods.

[0098] Polyolefin resins are obtained by polymerizing olefin monomers such as ethylene, propylene, butene, and isobutylene using known polymerization methods such as coordination polymerization.

[0099] Polycarbonate resins are obtained by carbonate reaction of polyols with polyfunctional carbonates such as diethyl carbonate using known methods.

[0100] Polyethyleneimine resins are obtained by ring-opening polymerization of aziridine compounds. Alternatively, polyethyleneimine resins can be grafted onto polyester resins obtained by reacting a cyclic ester compound with an amino group generated after the reaction and then performing ring-opening polymerization.

[0101] Epoxy resins are obtained by ring-opening polymerization of compounds having two or more glycidyl groups using a known method.

[0102] Furthermore, from the viewpoint of effectively obtaining excellent compatibility through adsorption onto quantum dots and scattering agents, the dispersion resin preferably has polar functional groups such as carboxyl, sulfonic acid, phosphate, amino, mercapto, and hydroxyl groups, and more preferably phosphate, amino, and mercapto groups. These not only provide excellent compatibility but also improve the luminescence quantum yield of the quantum dots, making them preferred in this respect.

[0103] Regarding the amount of dispersion resin used in this embodiment, it is preferably in the range of 0.1% by mass or more and 5% by mass or less relative to 100% by mass of the sum of polyfunctional (meth)acrylate and polyfunctional thiol, and more preferably in the range of 0.2% by mass or more and 4% by mass or less.

[0104] In this embodiment, a known organic solvent can be used as a diluent for quantum dots, as a reaction solvent during the synthesis of the dispersion resin, or for viscosity adjustment during the application of the composition containing quantum dots. Furthermore, the known organic solvent is preferably removed in stages during the curing process described later.

[0105] The solvents used in this embodiment are not limited to the following solvents, such as ester solvents like ethyl acetate, propyl acetate, and butyl acetate; ketone solvents like acetone, methyl ethyl ketone, and methyl isobutyl ketone; ether solvents like dioxane and tetrahydrofuran; aliphatic hydrocarbon solvents like n-hexane, cyclohexane, and methylcyclohexane; aromatic hydrocarbon solvents like toluene and xylene; alcohol solvents like methanol, ethanol, and isopropanol; amide solvents like dimethylformamide; and water. These solvents can be used individually or in any combination of two or more.

[0106] The composition containing quantum dots in the above-described embodiment comprises polyfunctional (meth)acrylates, polyfunctional thiols, reaction retarder, and quantum dots, and is more preferably composed of at least one of a scattering agent, a photopolymerization initiator, and a dispersion resin. The proportions of these substances are as described above.

[0107] Furthermore, a preferred embodiment of the composition containing quantum dots is characterized by comprising polyfunctional (meth)acrylates, polyfunctional thiols, a reaction retarder, and quantum dots, wherein the reaction retarder comprises a dithiocarbamate compound. In the dithiocarbamate compound, a good pot life can be obtained by containing tetraethylthiuram disulfide.

[0108] Furthermore, a preferred embodiment of the composition containing quantum dots is characterized by comprising a polyfunctional (meth)acrylate, a polyfunctional thiol, a reaction retarder, a scattering agent, a photopolymerization initiator, and quantum dots, wherein the molar ratio of the (meth)acrylate groups of the polyfunctional (meth)acrylate to the molar ratio of the thiol groups of the polyfunctional thiol is in the range of 0.8 or more and 5.5 or less, or the molar ratio of the (meth)acrylate groups of the polyfunctional (meth)acrylate to the molar ratio of the thiol groups of the polyfunctional thiol is in the range of 1.52 or more and 9.0 or less.

[0109] The composition with the sub-point content used in this embodiment can be further modified by using known additives, within a range that does not impair the effects of this embodiment, depending on the purpose. Examples of known additives include antioxidants, ultraviolet absorbers, antistatic agents, lubricants, surface conditioners, and viscosity modifiers. These can be used alone or in any combination of two or more.

[0110] <Content-content sheet components> like Figure 2 As shown, by curing the quantum dot-containing composition of this embodiment, for example, a quantum dot-containing sheet 1 can be obtained. Here, "sheet" refers to a shape with a thickness thinner than a plane, and can also be called a film.

[0111] In addition, such as Figure 3As shown, for example, by forming a quantum dot layer (ink layer) 3 on a substrate film 2 such as plastic, which is formed by curing a composition containing quantum dots, a laminated quantum dot sheet 1 can be obtained. Furthermore, the quantum dot sheet 1 can have the quantum dot layer 3 formed on one side of the substrate film 2, but in the case of application to the backlight device described later, the quantum dot layer 3 is preferably in the form of a film. From the viewpoint of the excellent durability of quantum dots (D), a film-like structure is preferred. Figure 4 As shown, the quantum dot sheet 1 is a laminated structure in which a substrate film 2 is laminated on both sides of a film-like quantum dot layer 3. Furthermore, when laminating the substrate film 2 and the quantum dot layer 3, known adhesives can be used for lamination, or the quantum dot composition of this embodiment can be used as an adhesive for curing.

[0112] Figure 5 This is an example of a schematic diagram showing the content sub-dot sheet 1 used in this embodiment. Figure 5 In this process, the quantum dot sheet 1 is formed from a thin plate (sheet or film) with a length dimension L, a width dimension W, and a thickness dimension T, and the L, W, and T can be changed to be optimal for the application. Furthermore, the quantum dot sheet 1 can be formed with a constant thickness, or it can be formed with a shape in which the thickness is deformed according to the location, or gradually changes in the length or width direction, or changes in stages.

[0113] Furthermore, the quantum dot sheet 1 used in this embodiment is formed by curing a composition of quantum dots, which, compared to the conventional method, can effectively suppress the degradation and fading of the quantum dot layer near the ends (edges) of the quantum dot sheet 1 over time. The reason for suppressing degradation through this embodiment is believed to be due to the core-shell structure of the quantum dots, the improved durability and dispersibility of the quantum dots themselves due to the ligands, the high crosslinking density of the resulting quantum dot layer through polyfunctional (meth)acrylates and polyfunctional thiols, and the effective suppression of oxygen intrusion by the polyfunctional thiols.

[0114] The substrate film 2 used as the quantum dot sheet 1 in this embodiment is not limited to the following, and can include, for example, polyester, polypropylene, polyethylene, polystyrene, AS resin, ABS resin, acrylic resin, methacrylic resin, polyvinyl chloride, polyacetal, polyamide, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, polysulfone, polyethersulfone, polyphenylene sulfide, polyamide-imide, polymethylpentene, liquid crystal polymer, epoxy resin, phenolic resin, urea resin, melamine resin, epoxy resin, diallyl phthalate resin, unsaturated polyester resin, polyimide, polyurethane, silicone resin, styrene-based thermoplastic elastomer, etc. These can be used individually or in any combination of two or more. From the viewpoint of excellent light transmittance, thermal stability, dimensional stability, and adhesion between the substrate film 2 and the quantum dot layer 3, polyester is preferred, and polyethylene terephthalate is more preferred. In addition, to improve the adhesion between the quantum dot layer 3 and the substrate film 2, pretreatments such as plasma treatment, corona treatment, and ozone treatment can be performed on the substrate surface (the adhesion surface with the quantum dot layer 3). Alternatively, an adhesive layer (primer treatment) can be provided between the quantum dot layer 3 and the substrate film 2.

[0115] In this embodiment, the quantum dot layer thickness can be 50 μm or less, preferably 2 to 30 μm or less. The sheet thickness is measured, for example, using a micrometer, by averaging the sheet thickness values ​​measured at three or more points.

[0116] For the surface (outer surface) of the substrate film of the content dot sheet 1 used in this embodiment, in order to effectively introduce excitation light and extract luminescence, a matting treatment can be performed.

[0117] In this embodiment, the total light transmittance of the sub-dot sheet 1 used is preferably 55% or more, and more preferably 65% ​​or more. Furthermore, the total light transmittance is determined by measurement according to the method in JIS K 7136:2000.

[0118] From the perspective of effectively utilizing the excitation light, the haze value of the sub-dot sheet 1 in this embodiment is preferably 85% or more, more preferably 90% or more, and even more preferably 95% or more. Furthermore, the haze value is determined by measurement according to the method in JIS K7136:2000.

[0119] In this embodiment, the content sub-dot sheet 1 can, for example, be assembled into... Figure 6 The backlight device 55 shown. Figure 6 In this embodiment, the backlight device 55 comprises a plurality of light-emitting elements 20 (LEDs) and a sub-dot sheet 1 opposite to the light-emitting elements 20. Figure 6As shown, each light-emitting element 20 is supported on the surface of the support body 52. Figure 6 In this display device 50, a backlight device 55 is disposed on the back side of a display unit 54 such as a liquid crystal display.

[0120] In addition, although Figure 6 Although not shown in the figure, in addition to the quantum dot sheet 1, there may be a diffuser plate for diffusing light and other sheets between the light-emitting element 20 and the display unit 54.

[0121] in addition, Figure 6 The content sub-dot sheet 1 shown is formed from a single sheet, but multiple content sub-dot sheets 1 can also be joined together in a manner that is specified in a certain size. Hereinafter, the structure formed by joining multiple content sub-dot sheets 1 together by splicing will be referred to as a composite content sub-dot sheet.

[0122] Here, the replacement of composite content sub-dot sheets is discussed. Figure 6 The display device 50 is configured with a quantum dot sheet 1 and a diffuser plate is disposed between the light-emitting element 20 and the composite quantum dot sheet, i.e., the configuration of light-emitting element 20 / diffuser plate / composite quantum dot sheet / display section 54. In this configuration, light emitted from the light-emitting element 20 and diffused by the diffuser plate is incident on the composite quantum dot sheet. Since the light diffused by the diffuser plate is incident on the composite quantum dot sheet, the intensity distribution of light caused by the distance from the light-emitting element 20 can be suppressed. In addition, compared with the case without a diffuser plate, the distance between the light-emitting element 20 and the composite quantum dot sheet is greater, so the heat emitted by the light-emitting element 20 has less impact on the quantum dots contained in the composite sheet.

[0123] In contrast, such as Figure 7 As shown, the arrangement can also be in the order of light-emitting element 20 / quantum dot sheet 21 / diffuser plate 22 / display unit 54. Therefore, even if uneven color emission occurs due to diffuse reflection at the seams of the quantum dot sheets 1 or due to quantum dot degradation caused by water vapor entering from the seams, color unevenness in the display unit 54 can be appropriately suppressed. That is, the light emitted from the quantum dot sheet 21 is diffused by the diffuser plate 22 before entering the display unit 54, thus suppressing color unevenness in the display unit 54.

[0124] Furthermore, when using the content-rich dot sheet 21, regardless of whether it is applied to... Figure 7 The display devices shown are preferably used with a diffuser plate disposed on the light emitting side of the quantum dot sheet 21.

[0125] like Figure 8As shown, the quantum dot sheet 1 of this embodiment can be assembled into a liquid crystal display element 60. The liquid crystal display element 60, from bottom to top as shown, comprises, for example, a direct-lit LED sheet 80, a partially reflective sheet (partial reflective layer) 81, a prism sheet 63, a diffuser sheet 64, a polarizer 65, a retardation film 66, a liquid crystal cell 67 composed of a glass substrate / liquid crystal / color filter, a retardation film 68, and a polarizer 69. The partially reflective sheet can use a dichroic filter (e.g., a "BLT" manufactured by 3M). The quantum dot sheet 1 is disposed on the surface of the partially reflective sheet 81. The quantum dot sheet 1 can be a sheet coated on the surface of the partially reflective sheet 81, or it can be a sheet material that is adhered to the surface of the partially reflective sheet 81; either approach is acceptable.

[0126] Figure 8 It is a direct type that arranges multiple LEDs vertically. Direct type is used for applications such as large displays.

[0127] The LED emits blue light. Therefore, a portion of the blue light passes through the partially reflective sheet 81 and is converted into red and / or green light in the dot matrix sheet 1. The converted red and green light is emitted upwards by the partially reflective sheet 81, not downwards.

[0128] Here, when using blue LEDs, in a configuration without a partially reflective sheet 81, blue light sometimes exhibits uneven color and brightness (halo phenomenon) due to diffusion and diffuse reflection during wavelength conversion in the sub-dot sheet 1. Therefore, by providing a partially reflective sheet 81 as in this embodiment, the halo phenomenon can be suppressed. In particular, as in this embodiment... Figure 8 As shown, increasing the number of LEDs in a direct-lit type is effective. Furthermore, by utilizing the partially reflective sheet 81 to reduce the transmission of blue light, the amount of blue light that can be reused can be increased, thereby improving brightness (luminous intensity). Therefore, high brightness can be achieved even if the quantum dots do not contain the limiting heavy metals represented by Cd and Pb.

[0129] Compared with conventional materials, the content dot sheet 1 used in this embodiment can effectively suppress the time-dependent changes in luminous intensity. Therefore, the wavelength conversion characteristics of the content dot sheet 1 used in this embodiment can be stabilized when used in backlight devices 55, liquid crystal display elements, etc., thereby achieving a longer lifespan for backlight devices 55 and liquid crystal display elements.

[0130] The content sub-dot sheet 1 used in this embodiment can be a flexible sheet. Therefore, the content sub-dot sheet 1 can be appropriately placed on a curved surface, etc.

[0131] The sub-dot sheet 1 used in this embodiment can, for example, ensure a standardized illuminance of 0.6 or higher after 1000 hours of durability testing. Preferably, it can ensure a standardized illuminance of 0.75 or higher, more preferably, it can ensure a standardized illuminance of 0.85 or higher, and even more preferably, it can ensure a standardized illuminance of 0.9 or higher.

[0132] In addition, such as Figure 9 As shown, the quantum dot sheet 1 of this embodiment can be configured with the following structure: a substrate film 2 is provided only on one side of the quantum dot layer 3, and the optical component 70 abuts against the side of the quantum dot layer 3 opposite to the substrate film 2. Thus, one side of the quantum dot layer 3 is protected by the substrate film 2, and the optical component 70 can be tightly fitted to the side of the quantum dot layer 3 opposite to the substrate film 2. A light guide plate or a diffuser plate is preferably used as the optical component 70. This quantum dot sheet 1 can be applied to backlight devices, display devices, and lighting devices.

[0133] also, Figure 9 The quantum dot sheet 1 shown can be formed into a laminated structure of optical component / quantum dot layer / substrate film by directly coating the quantum dot composition of this embodiment onto the surface of the optical component 70, then overlapping the substrate film 2 and thermally curing it.

[0134] For example, such as Figure 10 As shown, the side of the quantum dot sheet 71 without the substrate film 2, which has a substrate film 2 on only one side of the quantum dot layer 3, is positioned opposite the optical component 70, so that the quantum dot sheet 71 and the optical component 70 are tightly bonded. At this time, the quantum dot sheet 71 and the optical component 70 can be bonded together via an adhesive layer, or the surface of the quantum dot sheet 71 and the surface of the optical component 70 can be directly bonded together.

[0135] like Figure 11A As shown, the quantum dot sheet 71 has, for example, a first substrate film 73 bonded via a primer layer 72 on one side of the quantum dot layer 3, and a second substrate film 74 directly bonded to the side of the quantum dot layer 3 opposite to the first substrate film 73. Thus, both sides of the quantum dot layer 3 can be protected using the substrate films 73 and 74. As an example, the substrate films 73 and 74 can be formed from PET film. Alternatively, the first substrate film 73 can be a PET film, and the second substrate film 74 can be a PE film. Or, a PEN (polyethylene naphthalate) film can be used instead of a PET or PE film.

[0136] In the quantum dot sheet 71, the adhesion between the first substrate film 73 and the quantum dot layer 3 is stronger than the adhesion between the second substrate film 74 and the quantum dot layer 3. Then, as... Figure 10As shown, in the stage of attaching the quantum dot sheet 71 to the surface of the optical component 70, by going through the steps of peeling off the second substrate film 74 of the quantum dot sheet 71 and attaching the exposed quantum dot layer 3 to the surface of the optical component 70, it is possible to obtain... Figure 9 The content of the sub-dot sheet 1 is shown.

[0137] exist Figure 12 The diagram shows a manufacturing apparatus for manufacturing the content sub-dot sheet 1 of this embodiment. Figure 12 China disclosed that through Figure 4 An example of a method for manufacturing a quantum dot sheet 1 by coating a quantum dot composition onto a substrate film 2 and curing it to form a quantum dot layer 3.

[0138] like Figure 12 As shown, the structure includes a first blank roll 30a that feeds out a resin film 10a that will become a substrate film 2, a second blank roll 30b that feeds out a resin film 10b that will become a substrate film 2, a take-up roller 32, a joint 35 consisting of a pair of clamping rollers 33 and 34, a coating mechanism 36, a drying section 38, and a curing reaction section 41.

[0139] like Figure 12 As shown, a resin film 10a is fed from a first preform roll 30a, and a composition 37 containing quantum dots is coated on the surface of the resin film 10a using a coating mechanism 36. Examples of coating methods for the composition 37 containing quantum dots include coating methods using known coating machines or dip coating machines. Examples include gravure coating machines, curtain coating machines, dip coating machines, comma knife coating machines, die coating machines, and roller coating machines.

[0140] like Figure 12 As shown, a resin film 10a with a composition 37 containing sub-dots coated on its surface is heated by a drying section 38 equipped with a heater, a hot air oven, or other heating device, causing the solvent contained therein to evaporate. Alternatively, if the composition 37 containing sub-dots does not contain solvent, the drying section 38 may not be used.

[0141] Next, at the joint 35, the composition 37 containing quantum dots coated on the resin film 10a is bonded to the interface of the resin film 10b fed from the second blank roll 30b using a pressing device. Temperature may also be applied as needed during bonding. Furthermore, the above bonding operation is not required if the structure does not involve a quantum dot layer 3 sandwiched between the resin film 10a and the resin film 10b.

[0142] Next, a quantum dot layer 3 (see reference) is formed by passing through a curing reaction section 40 equipped with active energy ray irradiation devices such as ultraviolet irradiation devices and electron beam irradiation devices, which is irradiated by active energy rays. Figure 4Additionally, the active energy ray irradiation can be performed before or after the joining process at the joint 35.

[0143] Then, a sheet-like quantum dot sheet 39, composed of resin film 10a / quantum dot layer 3 / resin film 10b, is wound up by winding roller 32. By cutting the wound quantum dot sheet 39 into a specified size, it is possible to obtain... Figure 4 The sub-dot sheet 1 of the specified shape is shown. The sub-dot composition 37 of this embodiment has an excellent pot life and can be mass-produced into sub-dot sheets 39.

[0144] Furthermore, for the content-rich sub-dot sheet 1 of this embodiment, in order to ensure complete curing reaction, it can be aged for an appropriate time at a suitable aging temperature. The suitable aging temperature is not limited to the following, but is preferably in the range of 20 to 60°C, and more preferably in the range of 30 to 50°C. The suitable aging time is preferably in the range of 6 to 48 hours, and more preferably in the range of 10 to 24 hours.

[0145] The average thickness of the quantum dot layer 3 in the quantum dot sheet 1 of this embodiment is not limited to the following, but is preferably in the range of 70 μm, preferably 50 μm or less, and more preferably 2 to 30 μm. The average thickness of the quantum dot layer 3 in the quantum dot sheet 1 is calculated, for example, by subtracting the average thickness of the portion of the substrate film 2 used from the average thickness obtained by measuring the thickness of the quantum dot sheet 1 at 3 or more points using a micrometer.

[0146] Additionally, using Figure 12 The manufacturing apparatus shown, such as Figure 11A As shown, by providing a primer layer 72 only on one side of the quantum dot layer 3, it is possible to manufacture a quantum dot sheet 71 with different content, resulting in different adhesion between the quantum dot layer 3 and the substrate film 73.

[0147] Additionally, using Figure 12 The manufacturing apparatus shown is capable of manufacturing quantum dot film components in which a substrate film is provided on only one side of the quantum dot layer. In this case, the second blank roll 30b and the clamping rollers 33 and 34 are not required.

[0148] Example The effects of the present invention will be described below through embodiments and comparative examples. Furthermore, the present invention is not limited to the following embodiments.

[0149] <Experiments with Quantum Dots> In this embodiment, type I-III-VI chalcopyrite quantum dots free of RoHS-restricted substances were fabricated as cadmium-free quantum dots. Specifically, Ag-Ga-S quantum dots were fabricated. As a comparative example, commercially available InP was used.

[0150] Figure 13A The graph shown represents the experimental results from the green quantum dots; the horizontal axis represents wavelength, and the vertical axis represents absorption coefficient. Figure 13A As shown, the chalcopyrite quantum dots of this embodiment exhibit a higher absorption coefficient at 450 nm compared to InP. Regarding the absorption coefficient at 450 nm, this embodiment is approximately 5 times or more, preferably approximately 6 times or more, and more preferably approximately 7 times or more (in experiments, it was approximately 6 times or more, preferably approximately 7 times or more).

[0151] Figure 13B The graph shown represents the experimental results from the red quantum dot; the horizontal axis represents wavelength, and the vertical axis represents the absorption coefficient. Figure 14 As shown, the chalcopyrite-based quantum dots of this embodiment exhibit a higher absorption coefficient at 450 nm compared to InP. Regarding the absorption coefficient at 450 nm, this embodiment is approximately 1.5 times or more than the comparative example, and preferably approximately 2 times or more.

[0152] Figure 13C The upper section shown is the EDX mapping of Ag and Ga in the quantum dot of this embodiment, and the lower section is a schematic diagram showing a part of it.

[0153] The more Ag and Ga are detected, the stronger the blue color becomes. This indicates that Ag and Ga are primarily found in the nucleus of the quantum dot.

[0154] Figure 13D The upper section shown is the EDX mapping of Zn and S in the quantum dot of this embodiment, and the lower section is a schematic diagram showing a part of it.

[0155] The more Zn and S detected, the stronger the yellow color became. This indicates that Zn and S are primarily found within the shell of the quantum dot.

[0156] Next, the following composition with the following content sub-points is formed. First, the methods for determining various physical properties are explained.

[0157] <Determination of Number-Average Molecular Weight> Number average molecular weight was determined using gel permeation chromatography (GPC) with the dispersion resin as the sample. For samples soluble in tetrahydrofuran, tetrahydrofuran was used as the eluent. The determination was performed using a Tosoh HLC-8220 GPC system connected to two TSKgelsuperHZM-N columns, with the column temperature set at 40°C and the flow rate at 0.35 ml / min. The sample was prepared by dissolving 2 mg of the sample in 5 ml of the above eluent. The number average molecular weight was calculated using standard polystyrene. Furthermore, the number average molecular weight was not calculated for samples insoluble in the eluent or those that could not be determined by adsorption onto the column.

[0158] <Determination of Quantum Yield> Quantum dots and quantum dot sheets were used as samples, and the luminescence quantum yield was measured using an absolute PL quantum yield measuring apparatus (Hamamatsu Photonics, Quantaurus-QY C11347-01) with the excitation wavelength set to 450 nm. Furthermore, for quantum dots, quantum dots obtained by preparing a toluene solution with an absorbance of 1 at 450 nm using a 1 cm cuvette were used as samples.

[0159] <Determination of peak emission wavelength and half-width> Quantum dots were used as samples, and a spectrophotometer (Japan Spectrophotometer, FP-8500) was used to measure the peak wavelength and half-width of the emitted light using an excitation wavelength of 450 nm. Furthermore, quantum dots prepared by preparing a toluene solution with an absorbance of 1 at 450 nm using a 1 cm cuvette were also used as samples.

[0160] <Viscosity Measurement> The composition with the content sub-points described later was used as a sample, and the viscosity was measured at 25°C using a Type B viscometer (Toki Sangyo Co., Ltd., TVB-10M).

[0161] <Film Thickness Measurement> For the content sub-dot sheet obtained later, the thickness is determined by using a micrometer (Mitutoyo, high-precision digital micrometer MDH-25MB) from the average of the thickness values ​​measured at more than 3 points.

[0162] <Determination of Total Light Transmittance and Haze> For the sub-dot sheet obtained later, a sheet cut to a width of 50 mm and a length of 50 mm was used as a sample. Using a spectrophotometer (Nippon Denshoku Kogyo Co., Ltd., SH7000), the total light transmittance and haze value were measured three times according to the determination method in JIS K 7136:2000. The average of the three measurements was then taken as the total light transmittance and haze value.

[0163] <Quantum dot> In the experiment, powders containing quantum dots with a peak emission wavelength of 530 nm (green), a half-width of 30 nm, and a quantum yield of 90% in toluene solution (hereinafter referred to as green quantum dots) and powders containing quantum dots with a peak emission wavelength of 630 nm (red), a half-width of 30 nm, and a quantum yield of 90% in toluene solution (hereinafter referred to as red quantum dots) were used. Both are of type I-III-VI chalcopyrite series, and have a higher absorption coefficient at 450 nm compared to InP.

[0164] <Manufacturing of Dispersion Resins> Dispersion resins (G-1) to (G-6) are manufactured according to the methods shown below. Table 1 shows the raw materials and formulation amounts used in the manufacture, as well as the properties of the resulting dispersion resins.

[0165] <Manufacturing Example (1)> Nitrogen gas was introduced into a reaction vessel equipped with a stirrer, thermometer, reflux cooler, dropper, and nitrogen inlet tube. Simultaneously, 25.8 parts of toluene, 56.6 parts of n-butyl methacrylate (manufactured by Tokyo Chemical Co., Ltd.), and 3.5 parts of pentaerythritol tetra(3-mercaptopropionate) (manufactured by Tokyo Chemical Co., Ltd.) were added, and the mixture was stirred at room temperature for 30 minutes. Next, the temperature was raised to 90°C, and a solution containing 0.02 parts of 2,2'-azobis(isobutyronitrile) dissolved in 2.5 parts of toluene was added dropwise over 6 hours. The mixture was then stirred at 90°C for another 3 hours to carry out the polymerization reaction. After cooling to room temperature, the reaction solution was removed, and the solvent was removed by vacuum drying, thus obtaining a solid dispersion resin (G-1). Note that "parts" refers to "parts by mass." The same applies to the following experiments.

[0166] The resulting dispersion resin (G-1) is an acrylic resin with mercapto groups and a number average molecular weight of 2500.

[0167] <Manufacturing Example (2)> Nitrogen gas was purged into a reaction vessel equipped with a stirrer, thermometer, reflux cooler, dropper, and nitrogen inlet tube. Simultaneously, 25.7 parts of toluene, 28.9 parts of n-butyl methacrylate (manufactured by Tokyo Chemical Co., Ltd.), 28.9 parts of 2-ethylhexyl methacrylate, and 2.1 parts of pentaerythritol tetra(3-mercaptopropionate) (manufactured by Tokyo Chemical Co., Ltd.) were added, and the mixture was stirred at room temperature for 30 minutes. Next, the temperature was raised to 90°C, and a solution containing 0.02 parts of 2,2'-azobis(isobutyronitrile) dissolved in 2.5 parts of toluene was added dropwise over 6 hours. The mixture was then stirred at 90°C for another 3 hours to carry out the polymerization reaction. After cooling to room temperature, the reaction solution was removed, and the solvent was removed by vacuum drying, yielding a viscous liquid dispersion of resin (G-2).

[0168] The resulting dispersion resin (G-2) is an acrylic resin with mercapto groups and a number-average molecular weight of 3300.

[0169] <Manufacturing Example (3)> In a reaction vessel equipped with a stirrer, thermometer, reflux cooler, nitrogen inlet pipe, and vacuum piping, 86.9 parts of pentaerythritol tetra(3-mercaptopropionate) (manufactured by Tokyo Chemical Co., Ltd.) were added. The pressure inside the reaction vessel was reduced using a vacuum pump while stirring, and maintained for 30 minutes. Then, while stirring, 13.0 parts of tris(2-acryloyloxyethyl) isocyanurate (manufactured by Tokyo Chemical Co., Ltd.) heated to 60°C were added. After stirring until homogeneous, 0.1 parts of triethylamine were added, and the reaction was carried out with stirring for 3 hours, thereby obtaining a viscous liquid dispersion resin (G-3).

[0170] The resulting dispersion resin (G-3) is a thioether resin with mercapto groups and a number average molecular weight of 2100.

[0171] <Manufacturing Example (4)> As the dispersion resin (G-4), SOLSPERSE (registered trademark) 24000GR (manufactured by Lubrizol Corporation of Japan, a polyethyleneimine resin with amino groups) was used.

[0172] <Manufacturing Example (5)> As the dispersion resin (G-5), AJISPER (registered trademark) PB821 (manufactured by Ajinomoto Fine-Techno Co., Ltd., a polyester resin with amino groups) was used.

[0173] <Manufacturing Example (6)> As the dispersion resin (G-6), DISPERBYK (registered trademark)-111 (BYK-Chemie Japan Co., Ltd., a polyester resin with phosphate groups) is used.

[0174] <Preparation of compositions containing sub-dots> Compositions (X-1) to (X-21) containing sub-points were manufactured according to the method shown below. Tables 2 and 3 show the proportions of raw materials used in the manufacture and the results of the following pot life evaluation.

[0175] <Experimental Example 1> The mixture consisted of 60 parts of A-DCP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., dihydroxymethyl-tricyclodecane diacrylate, (meth)acrylate content 6.58 mmol / g) as a polyfunctional (meth)acrylate (A), 40 parts of EGMP-4 (manufactured by SC Organic Chemical Co., Ltd., tetraethylene glycol bis(3-mercaptopropionate), mercapto content 5.38 mmol / g) as a polyfunctional thiol (B), 1 part of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction delay agent (C), and quantum dots. (D) 0.4 parts green quantum dots, 0.07 parts red quantum dots, (E) 5 parts EPOSTAR (registered trademark) MS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as scattering agent, (F) 0.3 parts Irgacure (registered trademark) 184 (manufactured by BASF) as photopolymerization initiator, and (G) 1.37 parts dispersion resin (G-1) as dispersion resin, were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-1) containing quantum dots had a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 1.84.

[0176] <Experimental Example 2> The mixture includes 50 parts of A-TMPT (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate, 10.0 mmol / g of (meth)acrylate) as a multifunctional (meth)acrylate (A), 5 parts of UV-7650B (Nippon Synthetic, urethane acrylate resin, 0.0004 parts of acrylate) as a multifunctional thiol (B), 45 parts of TMMP (manufactured by SC Organic Chemical Co., Ltd., trimethylolpropane tri(3-mercaptopropionate), 7.53 mmol / g of mercapto groups) as a multifunctional thiol (B), 0.5 parts of triphenyl phosphite (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 5 parts of EPOSTAR MS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as a scattering agent (E), and Irgacure as a photopolymerization initiator (F). 0.6 parts of 184 (manufactured by BASF) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-2) had a molar ratio of (meth)acrylate groups of polyfunctional (meth)acrylate (A) to mercapto groups of polyfunctional thiol (B) of 1.48.

[0177] <Experimental Example 3> The reaction mixture consisted of 20 parts of A-TMPT (trimethylolpropane triacrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 10.0 mmol / g of methacrylate groups) as a polyfunctional (meth)acrylate (A), 30 parts of AD-TMP (bis(trimethylolpropane tetraacrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 8.51 mmol / g of methacrylate groups) as a polyfunctional thiol (B), 50 parts of PEMP (pentaerythritol tetra(3-mercaptopropionate, manufactured by SC Organic Chemical Co., Ltd., 8.19 mmol / g of mercapto groups) as a polyfunctional thiol (B), and disulfide as a reaction delaying agent (C). The composition (X-3) containing tetraethylthiuram (manufactured by Tokyo Chemical Industry Co., Ltd.) consists of 0.002 parts, green quantum dots (D) of 0.4 parts, red quantum dots of 0.07 parts, Techpolymer (registered trademark) MBX-5 (manufactured by Sekisui Chemicals Co., Ltd., crosslinked polymethyl methacrylate particles) of 0.5 parts, Irgacure 184 (manufactured by BASF) of 0.2 parts, and dispersion resin (G-4) of 1.37 parts. The mixture is gently shaken by hand and then stirred using a homogenizer until homogeneous. The resulting composition (X-3) has a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 1.12.

[0178] <Experimental Example 4> The mixture consisted of 45 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane)tetraacrylate, (meth)acrylate content 8.51 mmol / g) as a polyfunctional (meth)acrylate (A), 40 parts of PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate, mercapto content 8.19 mmol / g) as a polyfunctional thiol (B), and DPMP (manufactured by SC Organic Chemical Co., Ltd., dipentaerythritol hexa(3-mercaptopropionate, mercapto content 7.66 mmol / g). The following ingredients were added: 15 parts of triphenyl phosphite (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C); 0.3 parts of green quantum dots (D) and red quantum dots (D); 0.07 parts of rutile titanium dioxide (manufactured by Sakai Chemical Industry Co., Ltd.) as a scattering agent (E); 4 parts of OPTBEADS 2000M (manufactured by Nissan Chemical Co., Ltd., melamine resin-silica composite particles) as a dispersion resin (G); 0.3 parts of Irgacure TPO (manufactured by BASF) as a photopolymerization initiator (F); and 1.37 parts of dispersion resin (G-6) as a dispersion resin (G). The mixture was gently shaken by hand and then stirred using a homogenizer until homogeneous. The resulting composition (X-4) containing quantum dots had a molar ratio of acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 0.87.

[0179] <Experimental Example 5> The mixture includes 80 parts of A-TMPT (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate, (meth)acrylate content 10.0 mmol / g) as a polyfunctional (meth)acrylate (A), 20 parts of TMMP (manufactured by SC Organic Chemical Co., Ltd., trimethylolpropane tri(3-mercaptopropionate), mercapto content 7.53 mmol / g) as a polyfunctional thiol (B), 0.001 parts of tetraethyl thiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 0.2 parts of D-918 (manufactured by Sakai Chemical Industry Co., Ltd., R-type titanium dioxide) as a scattering agent (E), 6 parts of OPTBEADS 2000M (manufactured by Nissan Chemical Co., Ltd., melamine resin-silica composite particles), and Irgacure as a photopolymerization initiator (F). 0.8 parts of TPO (manufactured by BASF) and 1.37 parts of dispersion resin (G-6) as dispersion resin (G) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-5) had a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 5.31.

[0180] <Experimental Example 6> The mixture included 50 parts of A-TMPT (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate, 10.0 mmol / g of methacrylate) as a polyfunctional (meth)acrylate (A), 5 parts of A-DPH (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., dipentaerythritol hexaacrylate, 0.010 mmol / g of methacrylate) as a polyfunctional thiol (B), 35 parts of PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate), 8.19 mmol / g of mercapto), 10 parts of DPMP (manufactured by SC Organic Chemical Co., Ltd., dipentaerythritol hexa(3-mercaptopropionate), 7.66 mmol / g of mercapto), 0.3 parts of triphenyl phosphite (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction delay agent (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots, and EPOSTAR as a scattering agent (E). 7 parts of MS (Benzoguanidine-formaldehyde condensate particles manufactured by Nippon Shokubai Co., Ltd.), 0.8 parts of Irgacure 184 (manufactured by BASF) as photopolymerization initiator (F), and 1.37 parts of dispersion resin (G-3) as dispersion resin (G) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-6) with a content of sub-dots had a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 1.52.

[0181] <Experimental Example 7> The mixture includes 50 parts of A-TMPT (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate, 10.0 mmol / g of methacrylate) as a polyfunctional (meth)acrylate (A), 15 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate, 10.0 mmol / g of methacrylate), 35 parts of PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate, 8.19 mmol / g of mercapto) as a polyfunctional thiol (B), 0.002 parts of tetraethylthiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 1.0 part of D-918 (manufactured by Sakai Chemical Industry Co., Ltd., rutile titanium dioxide) as a scattering agent (E), and Irgacure as a photopolymerization initiator (F). 0.4 parts of BASF-manufactured 184, 1.0 part of dispersion resin (G-1) as dispersion resin (G), and 1.37 parts of dispersion resin (G-6) were gently shaken by hand and then stirred using a homogenizer until the mixture became homogeneous. The resulting composition (X-7) with the desired concentration had a molar ratio of (meth)acrylate groups in polyfunctional (meth)acrylate (A) to mercapto groups in polyfunctional thiol (B) of 2.19.

[0182] <Experimental Example 8> The mixture consisted of 40 parts of A-TMPT (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate, methacrylate content 10.0 mmol / g) as a polyfunctional (meth)acrylate (A), 15 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane tetraacrylate, meth)acrylate content 8.51 mmol / g) as a polyfunctional thiol (B), 45 parts of Karenz (registered trademark) MT PE1 (manufactured by Showa Denko Co., Ltd., pentaerythritol tetra(3-mercaptobutyrate), mercapto content 7.34 mmol / g) as a polyfunctional thiol (B), 0.002 parts of tetraethylthiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction delay agent (C), 0.4 parts of green quantum dots as quantum dots (D), 0.07 parts of red quantum dots as quantum dots (D), and EPOSTAR as a scattering agent (E). Five parts of MS (benzoguanamine-formaldehyde condensate particles manufactured by Nippon Shokubai Co., Ltd.), 0.3 parts of Irgacure 184 (manufactured by BASF) as photopolymerization initiator (F), and 1.37 parts of dispersion resin (G-2) as dispersion resin (G) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-8) had a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 1.60.

[0183] <Experiment Example 9> The mixture includes 50 parts of A-TMPT (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate, 10.0 mmol / g of methacrylate) as a polyfunctional (meth)acrylate (A), 10 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane tetraacrylate, 8.51 mmol / g of methacrylate) as a polyfunctional thiol (B), 40 parts of PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate), 8.19 mmol / g of mercapto) as a polyfunctional thiol (B), 0.003 parts of tetraethylthiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction delay agent (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 0.2 parts of D-918 (manufactured by Sakai Chemical Industry Co., Ltd., rutile titanium dioxide) as a scattering agent (E), and OPTBEADS. 4.5 parts of 2000M (melamine resin-silica composite particles manufactured by Nissan Chemical Co., Ltd.), 0.2 parts of Irgacure 184 (manufactured by BASF) as photopolymerization initiator (F), 0.1 parts of Irgacure TPO, and 1.37 parts of dispersion resin (G-4) as dispersion resin (G) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-9) had a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 1.79.

[0184] <Experimental Example 10> The mixture includes 50 parts of A-TMPT (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate, 10.0 mmol / g of methacrylate) as a polyfunctional (meth)acrylate (A), 10 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane tetraacrylate, 8.51 mmol / g of methacrylate) as a polyfunctional thiol (B), 40 parts of PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate), 8.19 mmol / g of mercapto) as a polyfunctional thiol (B), 0.003 parts of tetraethylthiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction delay agent (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 0.2 parts of D-918 (manufactured by Sakai Chemical Industry Co., Ltd., rutile titanium dioxide) as a scattering agent (E), and OPTBEADS. 4.5 parts of 2000M (Made by Nissan Chemical Co., Ltd., melamine resin-silica composite particles), 0.2 parts of Irgacure 184 (Made by BASF) as photopolymerization initiator (F), 0.1 parts of Irgacure TPO, and 1.37 parts of dispersion resin (G-5) as dispersion resin (G) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-10) had a molar ratio of acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 1.79.

[0185] <Experimental Example 11> The mixture consisted of 50 parts of A-TMPT (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate, (meth)acrylate content 10.0 mmol / g) as a polyfunctional (meth)acrylate (A), 10 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane tetraacrylate, (meth)acrylate content 8.51 mmol / g)) as a polyfunctional thiol (B), and PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate), mercapto content 8. 30 parts of DPMP (19 mmol / g), 10 parts of DPMP (manufactured by SC Organic Chemicals Co., Ltd., dipentaerythritol hexa(3-mercaptopropionate), mercapto content 7.66 mmol / g), 0.003 parts of tetraethylthiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 0.2 parts of D-918 (manufactured by Sakai Chemical Industry Co., Ltd., rutile titanium dioxide) as scattering agent (E), and OPTBEADS 4.5 parts of 2000M (melamine resin-silica composite particles manufactured by Nissan Chemical Co., Ltd.), 0.2 parts of Irgacure 184 (manufactured by BASF) as photopolymerization initiator (F), 0.1 parts of Irgacure TPO, and 1.37 parts of dispersion resin (G-6) as dispersion resin (G) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-11) had a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 1.82.

[0186] <Experimental Example 12> 100 parts of A-TMPT (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trimethylolpropane triacrylate, (meth)acrylate base content 10.0 mmol / g) as a multifunctional (meth)acrylate (A), 0.002 parts of tetraethyl thiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 5 parts of EPOSTAR MS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as a scattering agent (E), 0.4 parts of Irgacure 184 (manufactured by BASF) as a photopolymerization initiator (F), and 1.37 parts of dispersion resin (G-6) as a dispersion resin (G) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The ratio of the number of moles of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to the number of moles of mercapto groups in the polyfunctional thiol (B) in the resulting composition (X-12) is 1 / 0 (which is infinitely large due to division by zero).

[0187] <Experimental Example 13> 100 parts of TMMP (manufactured by SC Organic Chemicals Co., Ltd., trimethylolpropane tris(3-mercaptopropionate), mercapto content 7.53 mmol / g) as a polyfunctional thiol (B), 0.002 parts of tetraethyl thiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 5 parts of EPOSTAR MS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as a scattering agent (E), 0.4 parts of Irgacure 184 (manufactured by BASF) as a photopolymerization initiator (F), and 1.37 parts of dispersion resin (G-6) as a dispersion resin (G) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-13) has a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 0.

[0188] <Experimental Example 14> 50 parts of PEMP (manufactured by SC Organic Chemicals Co., Ltd., pentaerythritol tetra(3-mercaptopropionate), mercapto content 8.19 mmol / g) as a polyfunctional thiol (B), 50 parts of isobornyl methacrylate (manufactured by Tokyo Chemical Co., Ltd., (meth)acrylate content 4.50 mmol / g) as other compounds, 0.002 parts of tetraethyl thiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots, 5 parts of EPOSTAR MS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as a scattering agent (E), 0.4 parts of Irgacure 184 (manufactured by BASF) as a photopolymerization initiator (F), and 1.37 parts of dispersion resin (G-6) as a dispersion resin (G) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-14) has a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 0.

[0189] <Experimental Example 15> 50 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane)tetraacrylate, acrylate content 8.51 mmol / g) as a multifunctional (meth)acrylate (A), 50 parts of octyl mercaptoacetate (manufactured by Tokyo Chemical Industry Co., Ltd., mercapto content 4.89 mmol / g) as other compounds, 0.5 parts of triphenyl phosphite (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots, 5 parts of EPOSTAR MS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as a scattering agent (E), 0.4 parts of Irgacure 184 (manufactured by BASF) as a photopolymerization initiator (F), and 1.37 parts of dispersion resin (G-6) as a dispersion resin (G) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-15) has a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 0.43 / 0 (which becomes infinitely large due to division by zero).

[0190] <Experimental Example 16> The mixture was prepared by hand with 20 parts of triallyl isocyanurate (manufactured by Tokyo Chemical Industry Co., Ltd., allyl content 12.0 mmol / g), 25 parts of isobornyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., (meth)acrylate content 4.50 mmol / g), 0.4 parts of green quantum dots (D) and 0.07 parts of red quantum dots, 5 parts of EPOSTARMS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as scattering agent (E), 1 part of IrgacureTPO-L (manufactured by BASF) as photopolymerization initiator (F), and 54 parts of dispersion resin (G-3) as dispersion resin (G). The mixture was gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-16) has a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 0 / 0 (which is infinitely large due to division by zero).

[0191] <Experimental Example 17> The mixture was prepared by hand with 60 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane)tetraacrylate, (meth)acrylate content 8.51 mmol / g) as a polyfunctional (meth)acrylate (A), 40 parts of PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate) mercapto content 8.19 mmol / g) as a polyfunctional thiol (B), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 5 parts of EPOSTAR MS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as a scattering agent (E), 0.4 parts of Irgacure 184 (manufactured by BASF) as a photopolymerization initiator (F), and 1.37 parts of dispersion resin (G-2) as a dispersion resin (G). The mixture was gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-17) has a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 1.56.

[0192] <Experimental Example 18> The mixture was prepared by hand with 60 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane)tetraacrylate, (meth)acrylate content 8.51 mmol / g) as a polyfunctional (meth)acrylate (A), 40 parts of PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate), mercapto content 8.19 mmol / g) as a polyfunctional thiol (B), 0.5 parts of triphenyl phosphite (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 0.4 parts of Irgacure 184 (manufactured by BASF) as a photopolymerization initiator (F), and 1.37 parts of dispersion resin (G-2) as a dispersion resin (G). The mixture was gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-18) has a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 1.56.

[0193] <Experimental Example 19> The mixture was prepared by hand with 60 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane)tetraacrylate, (meth)acrylate content 8.51 mmol / g) as a polyfunctional (meth)acrylate (A), 40 parts of PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate), mercapto content 8.19 mmol / g) as a polyfunctional thiol (B), 0.004 parts of tetraethyl thiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction delay agent (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots, 5 parts of EPOSTAR MS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as a scattering agent (E), and 1.37 parts of dispersion resin (G-2) as a dispersion resin (G). The mixture was gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-19) has a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 1.56.

[0194] <Experimental Example 20> The mixture consisted of 35 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane)tetraacrylate, (meth)acrylate content 8.51 mmol / g) as a polyfunctional (meth)acrylate (A), 65 parts of PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate), mercapto content 8.19 mmol / g) as a polyfunctional thiol (B), 0.004 parts of tetraethyl thiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 5 parts of EPOSTAR MS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as a scattering agent (E), and Irgacure as a photopolymerization initiator (F). 0.4 parts of BASF-manufactured 184 and 1.37 parts of dispersion resin (G-2) were gently shaken by hand and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-20) had a molar ratio of (meth)acrylate groups in the polyfunctional (meth)acrylate (A) to mercapto groups in the polyfunctional thiol (B) of 0.56.

[0195] <Experimental Example 21> The mixture consisted of 90 parts of AD-TMP (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., bis(trimethylolpropane)tetraacrylate, (meth)acrylate content 8.51 mmol / g) as a polyfunctional (meth)acrylate (A), 10 parts of PEMP (manufactured by SC Organic Chemical Co., Ltd., pentaerythritol tetra(3-mercaptopropionate), mercapto content 8.19 mmol / g) as a polyfunctional thiol (B), 0.004 parts of tetraethylthiuram disulfide (manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction retarder (C), 0.4 parts of green quantum dots (D), 0.07 parts of red quantum dots (D), 5 parts of EPOSTAR MS (manufactured by Nippon Shokubai Co., Ltd., benzoguanamine-formaldehyde condensate particles) as a scattering agent (E), and Irgacure as a photopolymerization initiator (F). 0.4 parts of BASF-manufactured 184 and 1.37 parts of dispersion resin (G-2) were mixed, gently shaken by hand, and then stirred with a homogenizer until the mixture became homogeneous. The resulting composition (X-21) had a molar ratio of (meth)acrylate groups of polyfunctional (meth)acrylate (A) to mercapto groups of polyfunctional thiol (B) of 9.36.

[0196] <Evaluation of the pot life of composition (X) with sub-dot content> For the compositions (X-1) to (X-21) with the obtained content sub-points, the viscosity of the compositions immediately after preparation was measured. Then, the compositions were transferred to capped sample tubes and stirred with a roller stirrer for 24 hours at 25°C while allowing to stand. The viscosity of the compositions was measured again. The viscosity immediately after preparation and the rate of increase in viscosity after 24 hours were calculated using the following formula to evaluate the pot life of the compositions with each content sub-point.

[0197] Viscosity increase rate (%) = (Viscosity after 24 hours / Viscosity immediately after preparation) × 100 Viscosity (cps) after 24 hours Viscosity (cps) immediately after preparation In addition, the evaluation criteria are as follows.

[0198] ◎: Increase rate less than 120%. Good.

[0199] 〇: Increase rate of 120% or more but less than 150%. Practical.

[0200] △: Increase rate of 150% or more but less than 200%. Practical lower limit.

[0201] ×: Increase rate exceeds 200% or gelation occurs. Not suitable for practical use.

[0202] The meanings of the abbreviations in Tables 2 and 3 are as follows.

[0203] A-DCP: Manufactured by Shin-Nakamura Chemical Industry Co., Ltd., A-DCP (dihydroxymethyl-tricyclodecane diacrylate). A-TMPT: Manufactured by Shin-Nakamura Chemical Industry Co., Ltd., A-TMPT (trimethylolpropane triacrylate). AD-TMP: Manufactured by Shin-Nakamura Chemical Industry Co., Ltd., AD-TMP (bis(trimethylolpropane)tetraacrylate). A-DPH: Manufactured by Shin-Nakamura Chemical Industry Co., Ltd., A-DPH (dipentaerythritol hexaacrylate). UV-7650B: Manufactured by Japan Synthetic Chemical Industry Co., Ltd., UV-7650B (urethane acrylate). EGMP-4: Manufactured by SC Organic Chemicals, EGMP-4 (Tetraethylene glycol bis(3-mercaptopropionate)) TMMP: Manufactured by SC Organic Chemicals, TMMP (trimethylolpropane tris(3-mercaptopropionate)). PEMP: Manufactured by SC Organic Chemicals, PEMP (Pentaerythritol tetra(3-mercaptopropionate)) MT PE1: Manufactured by Showa Denko Corporation, Karenz MT PE1 (Pentaerythritol tetra(3-mercaptobutyrate)) DPMP: Manufactured by SC Organic Chemicals, DPMP (dipentaerythritol hexa(3-mercaptopropionate)) D-918: Manufactured by Sakai Chemical Industry Co., Ltd., D-918 (rutile titanium dioxide) MBX-5: Manufactured by Sekisui Chemicals Industrial Co., Ltd., Techpolymer MBX-5 (cross-linked polymethyl methacrylate particles). MS: EPOSTAR MS (benzoguanamine-formaldehyde condensate particles) manufactured by Nippon Shokubai Co., Ltd. 2000M: OPTBEADS 2000M (melamine resin-silica composite particles) manufactured by Nissan Chemical Co., Ltd. Irg184: Manufactured by BASF, Irgacure 184 (alkyl phenyl ketone photopolymerization initiator) TPO: Manufactured by BASF, Irgacure TPO (acylphosphine oxide photopolymerization initiator) TPO-L: Manufactured by BASF, Irgacure TPO-L (acylphosphine oxide photopolymerization initiator) <Manufacturing of Electron Dot Sheets> Using the compositions (X-1) to (X-21) with the content of sub-dots in Experimental Examples 1 to 21, laminated sheet components (Y-1) to (Y-21) were obtained according to the method shown below. Tables 4 and 5 show the compositions with the content of sub-dots used in the manufacture, the properties of the sheet components, and the results of the following performance tests.

[0204] On the primer-treated side of a 125 μm thick PET film (one side is treated with a matte finish and the opposite side is treated with a primer, without a barrier layer), a quantum dot composition (X-1) to (X-21) is applied using a roller coater to a quantum dot layer thickness of approximately 50 μm or less (preferably 2 to 30 μm). A 125 μm thick PET film of the same composition is then laminated with the primer-treated side facing out as the ink-coated side. Then, an ultraviolet irradiation device (120 W / cm²) is used. 2 High-pressure mercury lamps), with a cumulative luminous flux of 1000 mJ / cm². 2 The material is cured by ultraviolet irradiation. Then, to complete the curing reaction, it is left to stand at 40°C for 12 hours. This yields sheet components (Y-1) to (Y-21) with a thickness of approximately 350 μm.

[0205] (Performance Test) <Evaluation of Haze Value and Total Light Transmittance> The haze value and total light transmittance of the sheet components (Y-1) to (Y-21) were determined using the above method.

[0206] Evaluation of the luminescent quantum yield of sheet components The luminescence quantum yields of the sheet components (Y-1) to (Y-21) were determined using the method described above. The evaluation criteria are shown below.

[0207] ◎: Quantum yield is above 85%. Good.

[0208] 〇: Quantum yield is above 75% and less than 85%. Practical.

[0209] △: Quantum yield is above 65% and less than 75%. Practical lower limit.

[0210] ×: Quantum yield is less than 65%. Not practical.

[0211] <Evaluation of Fit> Using a 100mm x 100mm die manufactured by Dumbbell, cut 10 sheets each from (Y-1) to (Y-21). Visually evaluate the ends of the sheets for any lifting or peeling. The evaluation criteria are as follows.

[0212] ◎: 0 floats / peeled. Good.

[0213] ○: Float / peel off as 1. Practical.

[0214] △: Floating and peeling are counted as 2. Practical lower limit.

[0215] ×: More than 3 instances of floating or peeling are found. This is unacceptable.

[0216] <Evaluation of Durability over Time> Cut three 50mm×50mm sheets from the sheet components (Y-1) to (Y-21) respectively, and store them for 1000 hours under the following three levels of conditions. Calculate the retention rate of the peak intensity of green and red light before and after storage using the following formula.

[0217] Retention rate of luminous peak intensity (%) = (Luminous peak intensity after 1000 hours of storage / Luminous peak intensity before storage) × 100 In addition, the following storage conditions apply over time.

[0218] Condition 1: 60℃, 90%RH, with blue LED light on. Condition 2: 65℃, 95%RH, no blue LED light. Condition 3: 85℃, no blue LED light. The evaluation criteria for durability over time are as follows.

[0219] ◎: Maintenance rate above 90%. Good.

[0220] 〇: Maintenance rate is above 75% and below 90%. Practical. △: Maintenance rate is above 60% and below 75%. Practical lower limit. ×: Maintenance rate less than 60%. Not practical. <Evaluation of the end fading properties of sheet components> For the sheet parts (Y-1) to (Y-21) that were stored for 1000 hours under condition 1 in the above evaluation of durability over time, the length of the portion that faded from the end was measured at three points using a digital microscope (Keyence, VHS-5000). The fading performance was evaluated based on the average length. The evaluation criteria are as follows.

[0221] ◎: The fading area is less than 100μm. Good.

[0222] ○: The fading area is between 100μm and 200μm. It is usable.

[0223] △: The fading area is between 200μm and 500μm. Practical lower limit.

[0224] ×: The fading area is greater than 500μm. Not suitable for practical use.

[0225] As shown in Tables 4 and 5, Experimental Example 33 did not use polyfunctional thiols (B), resulting in insufficient oxygen barrier properties in the cured film, and significantly deteriorated durability and end fading.

[0226] In Experiment 34, because polyfunctional (meth)acrylate (A) was not used, the composition containing the sub-dots did not cure, resulting in insufficient bond strength and oxygen barrier properties, and significantly deteriorated adhesion, durability, and end fading.

[0227] In Experiment 35, because monofunctional (meth)acrylate was used instead of polyfunctional (meth)acrylate (A), the crosslinking density of the cured film was insufficient, the oxygen barrier properties were not adequately obtained, and the durability and end fading properties were significantly deteriorated.

[0228] In Experiment 36, because monofunctional thiols were used instead of polyfunctional thiols (B), the crosslinking density of the cured film was insufficient, and adequate oxygen barrier properties were not obtained, resulting in a significant deterioration in durability and end-coloring.

[0229] In Experiment 37, since monofunctional (meth)acrylates and low-reactivity polyfunctional aromatic esters were used instead of polyfunctional (meth)acrylates (A), a relatively good pot life was obtained even without the use of a reaction delay agent (C). However, the degree of crosslinking of the cured film was insufficient, and adequate oxygen barrier properties were not obtained. The durability and end fading properties were significantly deteriorated.

[0230] In Experiment 38, since no reaction delay agent (C) was used, significant thickening occurred after uniform stirring for about 10 minutes, making coating impossible. Therefore, various performance evaluations of the laminate could not be performed.

[0231] Experimental Example 39 is an example without the use of a scattering agent (E). It can be seen that although the results are excellent in terms of durability and end fading, it is difficult to select a sufficient optical path length because the excitation light is not converted by the wavelength of the quantum dot (D).

[0232] Experimental Example 40 is an example without the use of a photopolymerization initiator (F). In this example, almost no crosslinking reaction occurred upon UV irradiation, resulting in delamination, and various performance evaluations of the laminate could not be performed. Therefore, it is necessary to use a photopolymerization initiator (F) or an additive that replaces the photopolymerization initiator (F).

[0233] In Experiments 41 and 42, the ratio of the molar number of (meth)acrylate groups in the polyfunctional (meth)acrylate to the molar number of mercapto groups in the polyfunctional thiol was too small or too large, resulting in insufficient crosslinking density and inadequate oxygen barrier properties. Consequently, durability and end-coloring properties were prone to deterioration.

[0234] On the other hand, Examples 22-32 are sheet components made using a composition containing polyfunctional (meth)acrylate (A), polyfunctional thiol (B), reaction retarder (C), scattering agent (D), photopolymerization initiator (E) and quantum dot luminescent material (F) in a preferred range, which well balances the haze value, total light transmittance, luminescent quantum yield of the laminate, adhesion, durability and end fading.

[0235] In the above experimental examples, examples 29-32 showed excellent performance.

[0236] In Experimental Examples 29-32, since the average number of functional groups per molecule of polyfunctional (meth)acrylate (A) and polyfunctional thiol (B) is 2.5 or more, a sufficient crosslinking density of the cured film can be obtained compared with Experimental Example 1, which is outside this range, resulting in excellent durability and end-fading properties.

[0237] Experiments 29-32, due to the use of dispersant (G), achieved superior luminescence quantum yields compared to Experiment 23, which did not use dispersant (G).

[0238] Experimental Examples 29-32 achieved superior luminescence quantum yields compared to Experimental Examples 24 and 28, which did not use melamine and / or benzoguanamine structures, by using microparticles with melamine and / or benzoguanamine structures as scattering agents.

[0239] In Examples 29-32, since the ratio of the molar number of (meth)acrylate groups of the polyfunctional (meth)acrylate to the molar number of mercapto groups of the polyfunctional thiol is a more preferred range of 1.0 to 2.5, compared with Examples 25 and 26 which are outside this range, sufficient crosslinking density of the cured film can be obtained, resulting in excellent durability and end fading resistance.

[0240] In Examples 29-32, since the dispersant (G) was selected from at least one of acrylic resins, polyurethane resins, polyester resins, and polyethyleneimine resins, the compatibility of the quantum dots (D) was improved compared to Example 27, which used a sulfide resin, resulting in excellent luminescence quantum yield.

[0241] In this embodiment, the degradation from the end of the sheet is suppressed to below 500 μm, preferably to below 250 μm, more preferably to below 150 μm, and most preferably to below 50 μm.

[0242] <Brightness Experiment with or without Partially Reflective Sheets (Dichroic Filters)> The following samples were used in the experiment.

[0243] (Sample 1) Direct-to-bottom BL (blue light) + QD sheet + prism (Sample 2) Direct-lit BL (blue light) + QD-coated dichroic filter + prism (Sample 3) Direct-lit blue light (BL) + dichroic filter + QD sheet + prism (Sample 4) Direct-to-bottom BL (blue light) + QD sheet + prism + DBEF (Sample 5) Direct-down BL (blue light) + QD-coated dichroic filter + prism + DBEF (Sample 6) Direct-lit BL (blue light) + dichroic filter + QD sheet + prism + DBEF QD sheets contain quantum dots that emit red and green light. A QD-coated dichroic filter is a structure formed by coating the surface of a dichroic filter with a QD liquid containing quantum dots that emit red and green light, thus creating a QD layer. DBEF is a reflective polarizing film (Dual Brightness Enhancement Film) manufactured by 3M.

[0244] In the experiment, samples were divided into groups 1-3 and 4-6, and the relationship between wavelength and brightness (luminescence intensity) was measured. The luminescence intensity was measured using a spectrophotometer (FP-8500, manufactured by Japan Spectrophotometer Co., Ltd.).

[0245] Figure 14 It is a graph showing the relationship between wavelengths of 400nm to 700nm and luminescence intensity in samples 1 to 3. Figure 15 It is a graph showing the relationship between wavelengths of 400nm to 700nm and luminescence intensity in samples 4 to 6. Figure 16 It is a graph showing the relationship between wavelengths of 500nm to 700nm and luminescence intensity in samples 1 to 3. Figure 17 It is a graph showing the relationship between wavelengths of 500nm to 700nm and luminescence intensity in samples 4 to 6.

[0246] like Figure 14 , Figure 15 As shown, in samples 1 and 4, which do not have partially reflective sheets, the blue emission intensity is increased. In contrast, in samples 2, 3, 5, and 6, which have partially reflective sheets, the blue emission intensity is suppressed. In this embodiment, in particular, the I-III-VI type chalcopyrite system, which has a higher absorption coefficient of 450 nm compared to InP, was used as the quantum dot, thus more effectively reducing the blue emission intensity.

[0247] In addition, such as Figure 16 , Figure 17 As shown, in samples 1 and 4 without partially reflective sheets, the red and green luminescence intensities decreased. In contrast, in samples 2, 3, 5, and 6 with partially reflective sheets, the red and green luminescence intensities increased.

[0248] (Sample 7: Reference) Figure 22 ) Direct-to-bottom BL (blue light) + QD sheet + prism (Sample 8: Reference) Figure 23 ) Direct-lit BL (blue light) + dichroic filter + QD sheet + prism + DBEF (Sample 9: Reference) Figure 24 ) Direct-lit BL (blue light) + (dichroic filter + QD sheet) composite sheet + prism + DBEF (Sample 10: Reference) Figure 25 ) Direct-to-bottom BL (blue light) + QD sheet + prism + DBEF (Sample 11: Reference) Figure 26 ) Direct-lit BL (blue light) + (dichroic filter + QD sheet + prism) composite sheet + DBEF (Sample 12: Reference) Figure 27 ) Direct-lit BL (blue light) + (dichroic filter + QD sheet + prism + DBEF) composite sheet Figure 18 It is a graph showing the relationship between wavelengths of 400nm to 700nm and luminescence intensity in samples 7 to 9. Figure 19 It is a graph showing the relationship between wavelengths of 400nm to 700nm and luminescence intensity in samples 7 to 9. Figure 20 It is a graph showing the relationship between wavelengths of 500nm to 700nm and luminescence intensity in samples 7 to 9. Figure 21 This is a graph showing the relationship between wavelengths of 500nm to 700nm and luminescence intensity in samples 10 to 12. Furthermore, in Figure 20 , Figure 21 In, with Figure 18 , Figure 19 In comparison, the range of luminous intensity along the vertical axis is expanded.

[0249] like Figure 18 , Figure 19As shown, in samples 7 and 10 without partially reflective sheets, the blue emission intensity is higher, while in samples 8, 9, 11, and 12 with partially reflective sheets, the blue emission intensity is suppressed.

[0250] In addition, such as Figure 20 , Figure 21 As shown, in samples 7 and 10 without partially reflective sheets, the red and green luminescence intensities decreased. In contrast, in samples 8, 9, 11, and 12 with partially reflective sheets, the red and green luminescence intensities increased.

[0251] As can be seen from the above, by using a partially reflective sheet, it is possible to suppress the intensity of blue light emission and increase the intensity of red and green light emission, thereby increasing the brightness of white light emitted by wavelength conversion of light from blue LEDs and suppressing brightness unevenness.

[0252] In this embodiment, in particular, the I-III-VI type chalcopyrite system, which has a higher absorption coefficient of 450m compared to InP, was used as the quantum dot, thus more effectively reducing the blue emission intensity and increasing the OD (Optical Density) value.

[0253] <Experimental Results of Sheet Thickness> In the experiment, a sheet containing 40% green quantum dots, 15% dispersant, and the remainder being transparent resin was formed with a sheet thickness of 10 μm and placed under a blue backlight (Example 1).

[0254] In addition, a quantum dot sheet containing 30% red quantum dots, 5% dispersant, and the remainder being transparent resin was formed with a sheet thickness of 10 μm and placed in a blue backlight (Example 2).

[0255] Figure 28A This indicates the emission spectrum of the backlight. Figure 28B The emission spectrum of Example 1 is shown. Figure 28C The emission spectrum of Example 2 is shown.

[0256] In Example 1, the ratio of the luminous intensity of the blue wavelength to the peak intensity of the backlight is 1.2%, and in Example 2, the ratio of the luminous intensity of the blue wavelength to the peak intensity of the backlight is 10.3%. Thus, leakage of blue light is preferably suppressed in both Examples 1 and 2, and this effect is particularly significant in Example 1, which contains green quantum dot sheets.

[0257] in addition, Figure 28B The peak intensity of Example 1 shown is relative to Figure 28A The ratio of peak backlight intensity to actual backlight intensity is approximately 246.3%. Figure 28CThe peak intensity of Example 2 shown is relative to Figure 28A The peak intensity ratio of the backlight is about 61.4%, and color conversion is performed efficiently, especially in Example 1 with green quantum dot sheet.

[0258] <Experiments related to deterioration at the ends of the sheet> Figure 29 This represents the experimental results of the degradation mode from 0 hours to 1000 hours confirmed in the RA lighting test at a temperature of 60% and a humidity of 90% using the sub-dot sheet of Example 1. Figure 29 The upper part represents a photo. Figure 29 The lower section shows its schematic diagram. It can be seen that after about 1000 hours, the end turns slightly black, and a degradation of about 150μm is observed, but the degradation can be suppressed to below 500μm.

[0259] The QD sheet of this embodiment can be effectively applied to display methods, for example, it can be preferably applied to... Figure 30 The Mini LED shown in this embodiment has a high absorption coefficient for the QD sheet. Figure 30 The QD OLED and μLED shown are also effective.

[0260] In the comparative example of InP, to obtain the same absorption coefficient as in this embodiment, the sheet thickness must be increased. Especially... Figure 13A In the case of the green quantum dots shown, in InP, to ensure the same absorption coefficient and obtain high luminous intensity as in this embodiment, the sheet thickness must be set to approximately 6 times or more. Therefore, InP cannot be applied to QD OLEDs and μLEDs that particularly require thin-film processing. However, in this embodiment, even if the sheet thickness is 50 μm or less, preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less, high luminous intensity can be obtained (see reference). Figure 13A , Figure 13B , Figure 28B , Figure 28C (Experimental results).

[0261] Industrial availability According to the present invention, it is possible to provide quantum dots that can produce a sheet with a quantum dot layer thickness of 50 μm or less and excellent durability over time from the edge of the sheet, as well as a quantum dot sheet using the quantum dots, and a backlight device or display device. It is possible to use the quantum dot sheet of the present invention to realize a backlight device, display device, liquid crystal display element, etc. with stable wavelength conversion characteristics.

[0262] This application is based on Japan Patent Application No. 2023-170553, filed on September 29, 2023. Its entire contents are contained herein.

Claims

1. A quantum dot, characterized in that, It contains no RoHS-restricted substances and has a higher absorption coefficient at 450 nm compared to InP.

2. The quantum dot according to claim 1, characterized in that, The quantum dot contains a core composed of type I-III-VI chalcopyrite.

3. The quantum dot according to claim 2, characterized in that, Group I includes at least one of Ag or Cu, Group III includes at least one of Ga or In, and Group VI includes at least one of S, Se, or Te.

4. The quantum dot according to claim 1, characterized in that, It contains Ga and Zn, and the ratio of Zn to Ga is greater than or equal to 0.1 and less than or equal to 10.

5. The quantum dot according to claim 1, characterized in that, The quantum dot comprises a core, a shell formed on the surface of the core separated by a buffer layer, and ligands formed on the surface of the shell, wherein the shell is formed of ZnS.

6. A type of sheet material containing quantified particles, characterized in that, It is a quantum dot sheet formed by curing a composition containing quantum dots as described in claim 1, wherein the thickness of the quantum dot layer is less than 50 μm.

7. The content-rich sub-dot sheet according to claim 6, characterized in that, The degradation from the end of the sheet is less than 500 μm.

8. The content-rich sub-dot sheet according to claim 6, characterized in that, The sheet is an integral sheet with a dichroic filter or a prism sheet.

9. A backlight device or display device, characterized in that, It has the content sub-dot sheet as described in claim 6, and is composed of a narrow frame.

10. A display device, characterized in that, The content-rich sub-dot sheet is used for QD OLED or μLED.

11. The method for manufacturing the content-rich sub-dot sheet according to claim 6, characterized in that, The process includes a step of generating a composition containing said quantum dots, and a step of curing said quantum dot composition to obtain said quantum dot sheet. The composition containing quantum dots includes the quantum dots, polyfunctional (meth)acrylates, polyfunctional thiols, and a reaction retarder.

12. The method for manufacturing the content-rich dot sheet according to claim 11, characterized in that, The reaction delay agent is selected from at least one of phosphite compounds and dithiocarbamate compounds.

13. The method for manufacturing the content-rich dot sheet according to claim 11, characterized in that, The reaction delayer is selected from dithiocarbamate compounds.

14. The method for manufacturing the content-rich sub-dot sheet according to claim 11, characterized in that, It further includes a scattering agent, wherein the scattering agent is selected from at least one of the structures of melamine and benzoguanamine.

15. The method for manufacturing the sub-dot sheet according to claim 11, characterized in that, It further comprises a dispersion resin, wherein the dispersion resin is selected from at least one of acrylic resins, polyurethane resins, polyester resins and polyethyleneimine resins.

16. The method for manufacturing the content-rich dot sheet according to claim 11, characterized in that, The average number of functional groups per molecule of the polyfunctional (meth)acrylate and the polyfunctional thiol is 2.5 or more.

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