Quantum dot composition, resin composition, and wavelength conversion material

Abstract

Disclosed is a quantum dot composition which contains quantum dots that emit fluorescence by excitation light, and which is characterized in that each quantum dot is composed of a semiconductor nanoparticle core and a semiconductor nanoparticle shell that do not contain Cd and Pb, and the surface of each quantum dot is covered with a metal oxide. The surface of the quantum dot or the surface of the metal oxide is modified by a phosphonic acid derivative. As a result, provided is a quantum dot composition in which degradation of fluorescence emission efficiency is suppressed even if quantum dots having low toxicity are used.

Description

Technical Field

[0001] This invention relates to quantum dot compositions, resin compositions, and wavelength conversion materials. Background Technology

[0002] Quantum dots, composed of semiconductor particles with nanometer-sized diameters, trap excitons generated by light absorption within a nanometer-sized space, resulting in discrete energy levels for the semiconductor nanoparticles. Furthermore, their band gap is size-dependent. Therefore, quantum dots exhibit high fluorescence efficiency and a sharpened emission spectrum. Additionally, due to the band gap variation caused by particle size, they possess the characteristic of being able to control the emission wavelength, making them promising applications as wavelength conversion materials for solid-state lighting and displays (Patent Document 1).

[0003] Quantum dots exhibiting excellent fluorescence and luminescence properties include those containing Cd and Pb. However, due to the high toxicity of Cd and Pb to humans and the environment, restrictions on their use are being investigated worldwide, spearheaded by the EU's RoHS directive. Therefore, research is underway to develop quantum dots that do not contain these toxic elements.

[0004] In addition, as an installation method using quantum dots as wavelength conversion materials, a method is proposed that quantum dots are dispersed in a resin material and then laminated into a transparent film as a wavelength conversion film in a backlight unit (Patent Document 2).

[0005] However, quantum dots, due to their nanoscale particle size, possess a large specific surface area and high surface energy, making them highly reactive and prone to instability. Therefore, surface defects easily occur due to dangling bonds and oxidation reactions on the quantum dot surface, contributing to the degradation of fluorescence luminescence properties. It is known that currently obtained quantum dots suffer from this stability issue, with their luminescence properties deteriorating due to heat, humidity, and photoexcitation.

[0006] To prevent such degradation, organic ligands, called ligands, are coordinated to the surface of the synthesized quantum dots. Coordination through these ligands improves dispersibility in solvents and resins, and by passivating defects, it can suppress the degradation of fluorescence efficiency.

[0007] However, for quantum dot surfaces, if appropriate ligands are not selected, the ligands will detach from the quantum dot surface due to external influences such as heat and light irradiation, resulting in a deterioration in fluorescence luminescence efficiency.

[0008] The fluorescence efficiency of quantum dots changes over time, which can lead to defects such as uneven color, uneven light emission, and dead pixels when used in displays. Therefore, the stability of quantum dots is an important issue.

[0009] Existing technical documents Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2012-022028 Patent Document 2: Japanese Patent Publication No. 2013-544018 Patent Document 3: Japanese Patent Application Publication No. 2019-215516 Patent Document 4: Japanese Patent No. 5900720 Patent Document 5: Japanese Patent Application Publication No. 2018-109141 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] To address this problem, methods for loading quantum dots onto inorganic oxides have been studied (Patent Document 3), and methods for improving the stability of quantum dots by using gas barrier films with low oxygen and humidity permeability have been studied (Patent Document 4).

[0013] In the method of loading quantum dots onto oxides, oxidation reactions are suppressed by preventing oxygen and water from directly contacting the quantum dot surface, thereby inhibiting the degradation of fluorescence luminescence efficiency.

[0014] However, in conventional sol-gel methods that react metal oxide precursors in a liquid phase at low temperatures, most of the hydroxyl groups remain on the surface of the oxide after the reaction. These surface hydroxyl groups form hydrogen bonds with water molecules in the atmosphere, thus forming a thin, nanoscale layer of adsorbed water, or hydration layer, on the oxide surface.

[0015] The hydroxyl groups on the surface of the oxide are difficult to completely remove by heating. When using a composition of quantum dots loaded with oxides as a wavelength conversion material, the fluorescence efficiency will deteriorate due to prolonged exposure to light and heat. This is because the adsorbed water that permeates from the oxide surface into the interior gradually carries out the oxidation reaction on the surface of the quantum dots.

[0016] In addition, regarding the stabilization of the barrier film, there is also the issue of degradation caused by the diffusion of oxygen and water vapor from the end face of the film.

[0017] Furthermore, in mobile applications such as tablet computers and smartphones, there is a requirement for thinner wavelength conversion films. However, the barrier film is usually about 20 to 200 μm thick. In order to protect both sides of the film, the thickness will be at least 40 μm or more. Therefore, there is a limit to the reduction of the thickness of the wavelength conversion film.

[0018] Furthermore, the proposal includes a method for directly converting blue excitation light into green and red light as a color filter without using quantum dots as a wavelength conversion film (Patent Document 5). When using quantum dots as a color filter, it is not possible to use barrier films as in the aforementioned wavelength conversion films. The degradation of the fluorescence luminescence efficiency of quantum dots due to the curing of the quantum dot composition, subsequent preparation processes, and long-term use becomes a significant problem.

[0019] While research is being conducted on quantum dots that do not contain toxic elements, the degradation of fluorescence luminescence efficiency has become a problem.

[0020] The present invention aims to solve the above-mentioned problems, and its purpose is to provide a quantum dot composition that suppresses the degradation of fluorescence luminescence efficiency even when using quantum dots with low toxicity, a resin composition containing the quantum dot composition, and a wavelength conversion material.

[0021] means of solving technical problems

[0022] The present invention was made to achieve the above-mentioned objective, and provides a quantum dot composition comprising quantum dots that emit fluorescence upon excitation light, characterized in that the quantum dots are composed of a semiconductor nanoparticle core and a semiconductor nanoparticle shell free of Cd and Pb, the surface of the quantum dots is covered with a metal oxide, and the surface of the quantum dots or the surface of the metal oxide is modified with a phosphonic acid derivative.

[0023] If such a quantum dot composition is used, then even if it is composed of quantum dots with low toxicity, the degradation of fluorescence luminescence efficiency is suppressed.

[0024] In this case, the quantum dot is preferably composed of the semiconductor nanoparticle core and one or more semiconductor nanoparticle shells covering the semiconductor nanoparticle core.

[0025] Such a quantum dot composition is preferred in terms of fluorescence luminescence properties and stability.

[0026] At this time, the semiconductor nanoparticle core is preferably a single, multiple, or mixed crystal selected from ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AgGaS2, AgInS2, AgGaSe2, AgInSe2, CuGaS2, CuGaSe2, CuInS2, CuInSe2, ZnSiP2, and ZnGeP2.

[0027] Such a quantum dot composition is preferred in terms of fluorescence luminescence properties and stability.

[0028] At this time, the surface of the semiconductor nanoparticle core is preferably passivated by one or more compounds selected from GaCl3, GaI3, GaBr3, ZnCl2, ZnBr2, ZnI2, InCl3, InBr3, InI3, AgCl, AgBr, AgI, KCl, KBr, KI, NaCl, NaBr, NaI, MgCl2, MgBr2, MgI2, CaCl2, CaBr2, CaI2, MnCl2, MnBr2, MnI2, FeCl2, FeBr2, FeI2, CuCl2, CuBr2, CuI2, ZrCl4, ZrBr4, ZrI4, GeCl4, GeBr4, and GeI4.

[0029] Such a quantum dot composition is preferred in terms of fluorescence luminescence properties and stability.

[0030] At this time, the semiconductor nanoparticle shell is preferably a single, multiple, or mixed crystal selected from ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb.

[0031] Such a quantum dot composition is preferred in terms of improved fluorescence luminescence efficiency and stability.

[0032] At this time, the metal oxide is preferably a compound selected from at least one of TiO2, ZnO, Al2O3, SiO2, ZrO2, Fe2O3, MgO, Y2O3, HfO2, CeO2, In2O3, SnO2, WO3, CrO3, Ta2O3, BaTiO3, V2O5, NiO, NbO, Cu2O, CuO, and MoO3.

[0033] Such a quantum dot composition is preferred in terms of improved fluorescence luminescence efficiency and stability.

[0034] In this case, the phosphonic acid derivative is preferably a compound represented by the following formula (I).

[0035] [Chemical Formula 1]

[0036] (In formula (I), R1 is a monovalent organic group having one or more carbon atoms).

[0037] Such quantum dot compositions suppress the degradation of fluorescence luminescence efficiency and improve stability.

[0038] At this time, the phosphonic acid derivative is preferably from 3-phenyl-2-propenylphosphonic acid, tenofovir, 2-phosphonobutane-1,2,4-tricarboxylic acid, 4-phosphonobenzoic acid, vinylphosphonic acid, n-octylphosphonic acid, (3-bromopropyl)phosphonic acid, (4-bromobutyl)phosphonic acid, (2-bromoethyl)phosphonic acid, (4-bromophenyl)phosphonic acid, 3-phosphonopropionic acid, (4-hydroxyphenyl)phosphonic acid, hexylphosphonic acid, 4-phosphonobutyric acid, propionic acid, (4-aminobenzyl)phosphonic acid, (4-aminophenyl)phosphonic acid, 3-phosphonobenzoic acid, methylphosphonic acid, nonylphosphonic acid, diphenylmethylphosphonic acid, octadecylphosphonic acid, (aminomethyl)phosphonic acid, (2-phenylethyl)phosphonic acid, ethylphosphonic acid, butylphosphonic acid, decylphosphonic acid, dodecylphosphonic acid, (2-chloroethyl)phosphonic acid, 4- The phosphonic acid is selected from one or more of the following: methoxyphenylphosphonic acid, hexadecylphosphonic acid, (4-hydroxybenzyl)phosphonic acid, phenylphosphonic acid, (1H,1H,2H,2H-heptadecyl)phosphonic acid, tetradecylphosphonic acid, (1-aminoethyl)phosphonic acid, undecylphosphonic acid, heptylphosphonic acid, 10-carboxydecylphosphonic acid, 11-aminoundecylphosphonic acid hydrobromide, 11-hydroxyundecylphosphonic acid, 1H,1H,2H,2H-perfluorohexylphosphonic acid, 1H,1H,2H,2H-perfluorooctylphosphonic acid, 1H,1H,2H,2H-perfluorodecylphosphonic acid, 11-{2-[2-(2-methoxyethoxy)ethoxy]ethoxy}undecylphosphonic acid, 12-mercaptodecylphosphonic acid, and [11-(acryloyloxy)undecyl]phosphonic acid.

[0039] Such phosphonic acid derivatives can be used in the quantum dot compositions of the present invention to suppress the deterioration of fluorescence luminescence efficiency and improve stability.

[0040] In this case, the phosphonic acid derivative is preferably a compound represented by the following formula (II).

[0041] [Chemical Formula 2]

[0042] (In formula (II), R2 is a divalent organic group having one or more carbon atoms).

[0043] Such quantum dot compositions suppress the degradation of fluorescence luminescence efficiency and improve stability.

[0044] At this time, the phosphonic acid derivative is preferably selected from one or more of the following: m-xylene diphosphonic acid, o-xylene diphosphonic acid, methylene diphosphonic acid, alendronic acid, 1,4-butadiene diphosphonic acid, glycine-N,N-bis(methylene phosphonic acid), p-xylene diphosphonic acid, zoledronic acid, 1,3-propylidene diphosphonic acid, 1,5-pentylidene diphosphonic acid, 1,4-phenylene diphosphonic acid, 1,2-ethylidene diphosphonic acid, 1,6-hexylidene diphosphonic acid, minophosphonate, and 1-hydroxyethane-1,1-diphosphonic acid.

[0045] Such phosphonic acid derivatives can be used in the quantum dot compositions of the present invention.

[0046] At this time, the phosphonic acid derivative is preferably a compound represented by the following formula (III).

[0047] [Chemical Formula 3]

[0048] (In formula (III), R3 is a trivalent organic group having one or more carbon atoms).

[0049] Such quantum dot compositions suppress the degradation of fluorescence luminescence efficiency and improve stability.

[0050] At this point, the phosphonic acid derivative is preferably trimethylphosphonic acid (PM3)-(methylenephosphonic acid).

[0051] Such phosphonic acid derivatives can be used in the quantum dot compositions of the present invention.

[0052] In this case, the phosphonic acid derivative is preferably a compound represented by the following formula (IV).

[0053] [Chemical Formula 4]

[0054] (In formula (IV), R4 is a divalent organic group having one or more carbon atoms).

[0055] Such quantum dot compositions suppress the degradation of fluorescence luminescence efficiency and improve stability.

[0056] At this point, the phosphonic acid derivative is preferably N,N,N',N'-ethylenediaminetetra(methylenephosphonic acid).

[0057] Such phosphonic acid derivatives can be used in the quantum dot compositions of the present invention.

[0058] In this case, R1 preferably comprises any one of at least one of the following: a straight-chain or branched alkyl group having one or more carbon atoms, a straight-chain or branched alkylene group having one or more carbon atoms, an amino group, a carboxylic acid group, an ethoxy group, a bromo group, a chloro group, a phenolic group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

[0059] Such phosphonic acid derivatives can be used in the quantum dot compositions of the present invention.

[0060] In this case, R2 preferably comprises any one of at least one of the following: a straight-chain or branched alkyl group having one or more carbon atoms, a straight-chain or branched alkylene group having one or more carbon atoms, an amino group, a carboxylic acid group, an ethoxy group, a bromide group, a chloro group, a phenolic group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

[0061] Such phosphonic acid derivatives can be used in the quantum dot compositions of the present invention.

[0062] In this case, R3 preferably comprises any one of at least one of the following: a straight-chain or branched alkyl group having one or more carbon atoms, a straight-chain or branched alkylene group having one or more carbon atoms, an amino group, a carboxylic acid group, an ethoxy group, a bromo group, a chloro group, a phenolic group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

[0063] Such phosphonic acid derivatives can be used in the quantum dot compositions of the present invention.

[0064] In this case, R4 preferably comprises any one of at least one of a straight-chain or branched alkyl group having one or more carbon atoms, a straight-chain or branched alkylene group having one or more carbon atoms, an amino group, a carboxylic acid group, an ethoxy group, a bromide group, a chloro group, a phenolic group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

[0065] Such phosphonic acid derivatives can be used in the quantum dot compositions of the present invention.

[0066] In addition, the present invention provides a resin composition characterized in that the quantum dot composition described above is dispersed in a resin.

[0067] If such a resin composition is used, it becomes a resin composition that suppresses the deterioration of fluorescence luminescence efficiency.

[0068] At this time, the resin is preferably selected from at least one resin selected from epoxy resin, acrylic resin, fluorinated resin, silicone resin, carbonate resin, and glass resin.

[0069] Such resins can be used in the resin compositions of the present invention.

[0070] In addition, the present invention provides a wavelength conversion material comprising a cured product of the resin composition described above.

[0071] If such a wavelength conversion material is used, it can suppress the degradation of fluorescence luminescence efficiency and improve reliability.

[0072] Invention Effects

[0073] As described above, the quantum dot composition, the resin composition comprising the quantum dot composition, and the wavelength conversion material according to the present invention suppress the degradation of fluorescence luminescence efficiency even when using quantum dots with low toxicity. Detailed Implementation

[0074] The present invention will now be described in detail, but it is not limited thereto.

[0075] As mentioned above, there is a requirement for quantum dot compositions that suppress the degradation of fluorescence luminescence efficiency even when using quantum dots with low toxicity.

[0076] The inventors of this invention, through repeated and careful research into the above-mentioned problems, discovered a quantum dot composition that suppresses the degradation of fluorescence luminescence efficiency even when using quantum dots with low toxicity, thus completing this invention. The quantum dot composition is a quantum dot composition containing quantum dots that emit fluorescence upon excitation light. The quantum dots are characterized by being composed of a Cd- and Pb-free semiconductor nanoparticle core and a semiconductor nanoparticle shell, the surface of the quantum dots being covered with a metal oxide, and the surface of the quantum dots or the surface of the metal oxide being modified with a phosphonic acid derivative.

[0077] In addition, as described above, a resin composition is required that contains a quantum dot composition that suppresses the degradation of fluorescence luminescence efficiency even when using quantum dots with low toxicity.

[0078] The inventors of this invention, through repeated and careful research into the above-mentioned problems, discovered a resin composition that suppresses the deterioration of fluorescence luminescence efficiency even when using quantum dots with low toxicity, thus completing this invention. The resin composition is characterized in that the quantum dot composition described above is dispersed in the resin.

[0079] Furthermore, as mentioned above, a wavelength conversion material is required that uses low-toxicity quantum dots to suppress the degradation of fluorescence luminescence efficiency.

[0080] The inventors of this invention, through repeated and careful research into the above-mentioned problems, discovered a wavelength conversion material that suppresses the degradation of fluorescence luminescence efficiency even when using quantum dots with low toxicity, thus completing this invention. The wavelength conversion material is characterized by comprising a cured product containing the resin composition described above.

[0081] The embodiments of the present invention will be described below. However, in the present invention, the composition, type, and preparation method of quantum dots, metal oxides, and phosphonic acid derivatives are not limited to the following forms.

[0082] That is, the present invention is a quantum dot composition comprising quantum dots that emit fluorescence upon excitation light, wherein the quantum dots are composed of a semiconductor nanoparticle core and a semiconductor nanoparticle shell that are free of Cd and Pb, the surface of the quantum dots is covered with a metal oxide, and the surface of the quantum dots or the surface of the metal oxide is modified with a phosphonic acid derivative.

[0083] [Quantum dot] The structure of the quantum dots in this invention is not particularly limited as long as they consist of a semiconductor nanoparticle core and a semiconductor nanoparticle shell. Such quantum dots exhibit excellent fluorescence emission properties and stability. For example, in core / shell semiconductor nanoparticles with a core of nanoscale semiconductor particles and a shell of semiconductor particles with a larger band gap and lower lattice mismatch, the fluorescence emission efficiency is improved because excitons generated by the shell are trapped inside the core particle. Furthermore, the stability is improved because the core surface is covered by the shell.

[0084] Furthermore, the quantum dots are preferably composed of a semiconductor nanoparticle core and one or more semiconductor nanoparticle shells covering the semiconductor nanoparticle core. Such a quantum dot composition more effectively suppresses the degradation of fluorescence luminescence efficiency.

[0085] From a toxicity point of view, there are no particular limitations on the materials used for the core of semiconductor nanoparticles, as long as they do not contain Cd or Pb. For example, materials selected from group II-VI compounds, group III-V compounds, group I-III-VI compounds, group II-IV-V compounds, and alloys or mixed crystals of these can be used.

[0086] Specifically, materials selected as the core of semiconductor nanoparticles include ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AgGaS2, AgInS2, AgGaSe2, AgInSe2, CuGaS2, CuGaSe2, CuInS2, CuInSe2, ZnSiP2, and ZnGeP2, selected as single, multiple, or mixed crystals. Among these materials, ZnSe, ZnTe, and InP are particularly preferred in terms of fluorescence luminescence properties and stability.

[0087] Furthermore, the surface of the core / shell semiconductor nanoparticles is preferably passivated by an inorganic compound. This prevents the activation of defects on the core particle surface, improves fluorescence efficiency, and suppresses the degradation of fluorescence efficiency over time.

[0088] There are no particular limitations on the inorganic compounds used for passivation. For example, metal halides can be cited. From the viewpoint of improving fluorescence efficiency, compounds selected from at least one of GaCl3, GaI3, GaBr3, ZnCl2, ZnBr2, ZnI2, InCl3, InBr3, InI3, AgCl, AgBr, AgI, KCl, KBr, KI, NaCl, NaBr, NaI, MgCl2, MgBr2, MgI2, CaCl2, CaBr2, CaI2, MnCl2, MnBr2, MnI2, FeCl2, FeBr2, FeI2, CuCl2, CuBr2, CuI2, ZrCl4, ZrBr4, ZrI4, GeCl4, GeBr4, and GeI4 are particularly preferred.

[0089] From a toxicity point of view, there are no particular limitations on the material used as the shell of semiconductor nanoparticles, as long as it does not contain Cd or Pb elements. However, it is preferable to use materials with a large band gap and low lattice mismatch relative to the core material. Alloys and mixed crystals selected from group II-VI compounds and group III-V compounds can be used.

[0090] The specific shell material can be selected from ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb as a single, multiple, or mixed crystal material. Among these materials, ZnSe and ZnS are particularly preferred in terms of improved fluorescence efficiency and stability.

[0091] There are various methods for manufacturing semiconductor nanoparticles, such as liquid-phase methods and gas-phase methods, and there are no particular limitations in this invention. However, from the viewpoint of exhibiting high fluorescence luminescence efficiency, it is preferable to use semiconductor nanoparticles that can be obtained by reacting the precursor in a high-boiling-point nonpolar solvent at high temperature and using the hot soap method or hot injection method.

[0092] It should be noted that, in order to reduce surface defects, organic ligands, also known as ligands, are preferably coordinated on the surface of quantum dots during and after synthesis.

[0093] From the viewpoint of suppressing the aggregation of quantum dots, the ligands preferably contain aliphatic hydrocarbons. Examples of such ligands include oleic acid, stearic acid, palmitic acid, myristic acid, lauric acid, decanoic acid, octanoic acid, oleylamine, stearoyl (octadecyl)amine, dodecyl (lauryl)amine, decylamine, octylamine, octadecyl mercaptan, hexadecyl mercaptan, tetradecyl mercaptan, dodecyl mercaptan, decane mercaptan, octane mercaptan, trioctylphosphine, trioctylphosphine oxide, triphenylphosphine, triphenylphosphine oxide, tributylphosphine, and tributylphosphine oxide, etc., which can be used alone or in combination.

[0094] [Based on quantum dot surface coating of metal oxides] Since the quantum dots of the present invention are covered with metal oxides, it is believed that the direct contact between atmospheric oxygen and water with the quantum dot surface is prevented, and the degradation of their fluorescence efficiency is suppressed by inhibiting oxidation reaction.

[0095] In this invention, the "coverage" of the metal oxide on the quantum dot surface refers to a coating that can be partial or complete, provided that the degradation of fluorescence efficiency over time is suppressed. Furthermore, the coating can be a uniform layer such as a core-shell structure, a non-uniform layer, or a structure such as metal oxide coating multiple semiconductor nanoparticles. The film thickness of the metal oxide is not particularly limited, but from the viewpoint of light transmittance, it is preferably 200 nm or less.

[0096] In this invention, the type of oxide coating is not particularly limited, and examples include at least one compound selected from TiO2, ZnO, Al2O3, SiO2, ZrO2, Fe2O3, MgO, Y2O3, HfO2, CeO2, In2O3, SnO2, WO3, CrO3, Ta2O3, BaTiO3, V2O5, NiO, NbO, Cu2O, CuO, and MoO3. From the viewpoint of improving the stability of quantum dots, TiO2, Al2O3, SiO2, and ZrO2 are more preferred.

[0097] There are no particular limitations on the method for forming the metal oxide coating, but from the viewpoint of selectively reacting on the surface of quantum dots, a method of reacting the metal oxide precursor in the liquid phase is preferred.

[0098] In this invention, as an example, a method for forming an oxide coating using microwave treatment can be described. By using microwaves, the metal oxide precursor can be heated directly from the inside, allowing for selective reaction in a shorter time, thereby forming an oxide layer on the surface of the quantum dots.

[0099] The term "microwave" as used here generally refers to electromagnetic waves with a vibration frequency of 300 MHz to 3 THz. Additionally, one method of microwave irradiation is, for example, using the flexi WAVE manufactured by Milestone General, but there are no particular limitations.

[0100] The preferred coating process involves applying a metal oxide coating to the surface of semiconductor nanoparticles by microwave irradiation of the coexisting quantum dots and metal oxide precursor. This efficiently forms a metal oxide coating layer and suppresses the degradation of fluorescence luminescence efficiency.

[0101] At this point, the preferred dispersion medium for quantum dots and metal oxide precursors is one or more of polar solvents, non-polar solvents, and ionic liquids, in which the coating layer is formed.

[0102] Furthermore, the solvent used in this coating process is preferably one or more solvents selected from toluene, hexane, cyclohexane, benzene, and diethyl ether. These non-polar solvents can further improve the dispersibility of semiconductor nanoparticles.

[0103] In addition, when the solvent is a non-polar solvent, a heating element called Weflon, which contains carbon-based PTFE resin and is used in the coating process, can be used as a microwave-absorbing element.

[0104] There are no particular limitations on the precursors used for metal oxides, but it is preferable to use one or more selected from metal alkoxides, metal halides, and metal complexes. From the viewpoint of stability, silanolates, aluminum alkoxides, zirconium alkoxides, and titanium alkoxides are particularly preferred as precursors for metal oxides.

[0105] In this case, a catalyst is preferably used during the coating process to promote the reaction of the metal oxide precursor. In particular, when using metal alkoxides, a catalyst is preferred to promote the sol-gel reaction. Acidic or alkaline aqueous solutions can be cited as catalysts, but from the viewpoint of the coating thickness, an alkaline aqueous solution is particularly preferred.

[0106] Furthermore, from the viewpoint of dispersibility of the metal oxide precursor, a surfactant can be added during the coating process. There are no particular limitations on the surfactant, but examples include quaternary ammonium salts such as hexadecyltrimethylammonium bromide as cationic surfactants, carboxylates and sulfonates as anionic surfactants, and polyvinyl alkyl ethers and hexadecyltrimethylammonium bromide as nonionic surfactants. From the viewpoint of dispersibility of the metal oxide precursor, cationic surfactants are particularly preferred.

[0107] Furthermore, the coating process is preferably performed in the presence of an alcohol. When coating is performed in the presence of an alcohol, the dispersibility of the metal oxide precursor is superior. Additionally, when a surfactant is added, dispersibility can be improved by dissolving it in a polar solvent such as an alcohol.

[0108] At this time, the reaction temperature of microwave irradiation treatment varies depending on the solvent, but from the viewpoint of preventing the deterioration of fluorescence luminescence efficiency, it is preferably 40 to 200°C, and more preferably 50 to 110°C.

[0109] For the oxide coating process, microwave treatment is used as an example of this embodiment, but there are no particular limitations as long as the quantum dot surface is "coated" by an oxide layer.

[0110] [phosphonic acid derivatives] As described above, in this embodiment, by reacting the metal oxide precursor in solution, a metal oxide coating layer is formed on the surface of the quantum dots, thereby preventing water and oxygen in the atmosphere from directly contacting the surface of the quantum dots and suppressing the deterioration of fluorescence luminescence efficiency.

[0111] However, multiple hydroxyl groups remain on the outer surface of the oxide after the oxide coating is formed. When these hydroxyl groups come into contact with water in the atmosphere, they form a thin, nanoscale layer of adsorbed water, or hydration layer, on the oxide surface through hydrogen bonds.

[0112] When a composition with an oxide coating on the surface of quantum dots as described above is used as a wavelength conversion material, the adsorbed water gradually penetrates into the internal surface of the quantum dots due to prolonged exposure to external stimuli caused by light and heat, promoting surface oxidation. This is believed to cause a deterioration in fluorescence efficiency during long-term use. To suppress this deterioration in fluorescence efficiency, it is preferable to remove the hydroxyl groups on the surface of the oxide as much as possible.

[0113] However, it is difficult to completely remove the hydroxyl groups on the surface of the metal oxide by heating. Although it also depends on the composition of the metal oxide, it must be a heating operation above about 500°C. Since heating in this temperature range will cause morphological changes of quantum dots, deterioration of luminescence efficiency and loss of activity, it is difficult to remove the hydroxyl groups by heating alone.

[0114] Therefore, the necessary modifier for removing hydroxyl groups from the oxide surface in this invention is a phosphonic acid derivative. The quantum dot composition in this embodiment is composed of the above-mentioned quantum dots, an oxide covering the surface of the quantum dots, and a phosphonic acid derivative modifying the surface of the quantum dots or the oxide.

[0115] Phosphonic acid derivatives are stable compounds that do not self-polymerize, so they do not precipitate in the whole and selectively attach to and modify oxide or quantum dot surfaces.

[0116] In particular, on the oxide surface, through heating treatment at around tens of degrees, the hydroxyl groups of the metal oxide and the phosphonic acid derivative undergo a dehydration condensation reaction, thereby removing the hydroxyl groups on the oxide surface and modifying the oxide surface with phosphonic acid derivative.

[0117] Furthermore, for the unbonded oxygen sites on the oxide surface, H+ is continuously supplied from the OH groups of the phosphonic acid derivative. +(Proton), therefore, the above dehydration condensation reaction is repeated, and the phosphonic acid derivative is tightly modified on the oxide surface.

[0118] In this embodiment, "modification" refers to the state in which phosphonic acid adheres to the surface of a metal oxide or quantum dot. The adhesion of phosphonic acid derivatives to the surface caused by "modification" can be partial or complete, indicating a state in which at least a portion of the surface is adhered.

[0119] The "attachment" mentioned above can be physical adsorption or chemical bonding, such as broadly referring to covalent bonds, ionic bonds, hydrogen bonds, or combinations thereof.

[0120] In addition, as an example, the quantum dot composition described above, consisting of quantum dots, an oxide coating, and modifications based on phosphonic acid derivatives, may also be in a state where organic ligands and phosphonic acid derivatives coexist on the surface of metal oxides or quantum dots during synthesis.

[0121] There are no particular limitations on the types of phosphonic acid derivatives. For example, the structure of the compound is preferably a compound represented by at least one of the following formulas (I), (II), (III) and (IV).

[0122] [Chemical Formula 5]

[0123] (In formula (I), R1 is a monovalent organic group having one or more carbon atoms).

[0124] [Chemical Formula 6]

[0125] (In formula (II), R2 is a divalent organic group having one or more carbon atoms).

[0126] [Chemical Formula 7]

[0127] (In formula (III), R3 is a trivalent organic group having one or more carbon atoms).

[0128] [Chemical Formula 8]

[0129] (In formula (IV), R4 is a divalent organic group having one or more carbon atoms).

[0130] In a certain embodiment of the compounds of formulas (I) to (IV), R1 to R4 preferably comprise any one of at least one straight-chain or branched alkyl group having one or more carbon atoms, straight-chain or branched alkylene group having one or more carbon atoms, amino group, carboxylic acid group, ethoxy group, bromo group, chloro group, phenolic group, perfluoroalkyl group, hydroxy group, phenyl group, thiol group, acryloyl group, and oligoethylene glycol group.

[0131] Specifically, examples of formula (I) include 3-phenyl-2-propenylphosphonic acid, tenofovir, 2-phosphonobutane-1,2,4-tricarboxylic acid, 4-phosphonobenzoic acid, vinylphosphonic acid, n-octylphosphonic acid, (3-bromopropyl)phosphonic acid, (4-bromobutyl)phosphonic acid, (2-bromoethyl)phosphonic acid, (4-bromophenyl)phosphonic acid, 3-phosphonopropionic acid, (4-hydroxyphenyl)phosphonic acid, hexylphosphonic acid, 4-phosphonobutyric acid, propionic acid, (4-aminobenzyl)phosphonic acid, (4-aminophenyl)phosphonic acid, 3-phosphonobenzoic acid, methylphosphonic acid, nonylphosphonic acid, diphenylmethylphosphonic acid, octadecylphosphonic acid, (aminomethyl)phosphonic acid, (2-phenylethyl)phosphonic acid, ethylphosphonic acid, butylphosphonic acid, decylphosphonic acid, dodecylphosphonic acid, and (2-chloroethyl)phosphonic acid. Acids, 4-methoxyphenylphosphonic acid, hexadecylphosphonic acid, (4-hydroxybenzyl)phosphonic acid, phenylphosphonic acid, (1H,1H,2H,2H-heptadecyl)phosphonic acid, tetradecylphosphonic acid, (1-aminoethyl)phosphonic acid, undecylphosphonic acid, heptylphosphonic acid, 10-carboxydecylphosphonic acid, 11-aminoundecylphosphonic acid·hydrobromide, 11-hydroxyundecylphosphonic acid, 1H,1H,2H,2H-perfluorohexylphosphonic acid, 1H,1H,2H,2H-perfluorooctylphosphonic acid, 1H,1H,2H,2H-perfluorodecylphosphonic acid, 11-{2-[2-(2-methoxyethoxy)ethoxy]ethoxy}undecylphosphonic acid, 12-mercaptodecylphosphonic acid, and [11-(acryloyloxy)undecyl]phosphonic acid.

[0132] Specifically, examples of formula (II) include m-xylene diphosphonic acid, o-xylene diphosphonic acid, methylene diphosphonic acid, alendronic acid, 1,4-butadiene diphosphonic acid, glycine-N,N-bis(methylene diphosphonic acid), p-xylene diphosphonic acid, zoledronic acid, 1,3-propylidene diphosphonic acid, 1,5-pentylidene diphosphonic acid, 1,4-phenylene diphosphonic acid, 1,2-ethylidene diphosphonic acid, 1,6-hexylidene diphosphonic acid, minophosphonate, and 1-hydroxyethane-1,1-diphosphonic acid.

[0133] As an example of formula (III), specifically, nitrotris(methylenephosphonic acid) can be cited.

[0134] As an example of formula (IV), specifically N,N,N',N'-ethylenediaminetetra(methylenephosphonic acid) can be cited.

[0135] The above-mentioned phosphonic acid derivatives can be used alone or in combination of two or more.

[0136] There is no particular limitation on the heating temperature when modifying quantum dot surfaces or metal oxide surfaces with the above-mentioned phosphonic acid derivatives, but for efficient modification, the heating temperature is preferably in the range of 50 to 300°C, and more preferably in the range of 80 to 200°C. Within this range, the quantum dot surfaces can be modified more efficiently.

[0137] Regarding the amount of phosphonic acid derivative added as the above-mentioned surface modifier, there is no particular limitation as long as the phosphonic acid derivative can modify the surface of quantum dots or metal oxides. For example, when it is less than 30 wt%, it can suppress the aggregation of quantum dots and the precipitation of phosphonic acid derivatives. Therefore, it is preferable that when it is more than 0.01 wt%, the effect of modifying the surface of quantum dots or metal oxides is fully utilized. Therefore, the weight of the added surface modifier relative to the solid weight of quantum dots is preferably in the range of 0.01 to 30 wt%, and more preferably in the range of 0.05 to 20 wt%.

[0138] [Quantum dot composition] A quantum dot composition in which the surface of the quantum dots is covered by the aforementioned oxide layer and the surface of the quantum dots or the oxide layer is modified with phosphonic acid can suppress the degradation of fluorescence luminescence efficiency and improve stability by inhibiting the oxidation reaction on the surface of the quantum dots.

[0139] [Resin Composition] Furthermore, the above-mentioned quantum dot composition can be used as a resin composition dispersed in a resin. The resin material is not particularly limited, but preferably a material that does not cause aggregation of the quantum dot composition or deterioration of fluorescence luminescence efficiency. Examples include at least one selected from epoxy resins, acrylic resins, fluoropolymer resins, silicone resins, carbonate resins, and glass resins.

[0140] For these resin compositions to improve fluorescence luminescence efficiency, high light transmittance is preferred, and light transmittance of 80% or more is particularly preferred.

[0141] In addition, there is no particular limitation on the concentration of quantum dots in the resin composition, which can be appropriately adjusted according to the film thickness, the luminous efficiency of the quantum dots, and the characteristics of the target wavelength conversion material.

[0142] In addition, the resin composition may contain substances other than quantum dot compositions, or microparticles of silicon dioxide, zirconium oxide, aluminum oxide, titanium dioxide, etc., as light scatterers, or inorganic phosphors and organic phosphors.

[0143] Examples of inorganic phosphors include YAG, LSN, LYSN, CASN, SCASN, KSF, CSO, β-SIALON, GYAG, LuAG, SBCA, etc. Examples of organic phosphors include perylene derivatives, anthraquinone derivatives, anthracene derivatives, phthalocyanine derivatives, anthocyanin derivatives, dioxazine derivatives, benzoxazinone derivatives, coumarin derivatives, quinophthalone derivatives, benzoxazole derivatives, pyrazoline derivatives, etc.

[0144] [Wavelength conversion materials] Furthermore, this invention provides a wavelength conversion material comprising a cured form of the above-described resin composition. The wavelength conversion material can be used directly or processed. As one example, a wavelength conversion film is provided where a quantum dot composition is dispersed in a resin by processing it into a sheet and then curing it.

[0145] There are no particular limitations on the manufacturing method of wavelength conversion materials. For example, a quantum dot composition can be dispersed in a resin composition, coated onto a transparent film such as PET or polyimide, and cured. The wavelength conversion material can then be obtained by lamination.

[0146] The transparent film can be coated using methods such as spraying, inkjeting, spin coating, rod coating, and doctor blade coating to form a resin layer. Furthermore, there are no particular limitations on the thickness of the resin layer and the transparent film; they can be appropriately selected depending on the application. As long as it is such a wavelength-converting material, the degradation of fluorescence luminescence efficiency is suppressed, and reliability is improved.

[0147] Example

[0148] The present invention will be specifically described below using manufacturing examples, embodiments, and comparative examples, but the present invention is not limited to these.

[0149] (Evaluation of luminescent properties) In the manufacturing examples, embodiments, and comparative examples, as an evaluation of the fluorescence luminescence properties of quantum dots, quantum dot compositions, and wavelength conversion materials, the fluorescence luminescence efficiency (internal quantum efficiency) at an excitation wavelength of 450 nm was measured using a quantum efficiency measurement system (QE-2100) manufactured by Otsuka Electronics Co., Ltd.

[0150] (The manufacture of quantum dots) (Manufacturing Example 1) Add 0.070 g (0.24 mmol) indium acetate, 0.256 g (0.72 mmol) palmitic acid, and 4.0 mL 1-octadecene to a flask. Heat and stir at 100 °C under reduced pressure, and degas for one hour while dissolving.

[0151] After cooling the flask to room temperature, rinse it with nitrogen and add 0.50 mL (0.17 mmol) of a 10 vol% (tri)trimethylsilylphosphine / octadecene solution to the flask. Heat the flask to 300 °C and synthesize InP semiconductor core particles by stirring for 20 minutes.

[0152] Next, the flask was cooled to 200°C, and 0.10 mL (0.02 mmol) of gallium(III) chloride / octadecene solution was added and heated for 30 minutes to passivate the surface of the InP semiconductor nuclei.

[0153] Further, after heating the flask to 240°C, 4.0 mL (1.2 mmol) of 0.30 M zinc stearate / octadecene solution was added and stirred for 30 minutes. Further, 0.60 mL (0.90 mmol) of 1.5 M selenium / trioctylphosphine solution was added to the flask and stirred for 30 minutes.

[0154] Next, after cooling the flask to room temperature, add 0.22 g (1.1 mmol) of zinc acetate, and heat and stir at 100 °C under reduced pressure, degassing for one hour while dissolving. After rinsing the flask with nitrogen, heat to 230 °C, add 0.48 mL (2.0 mmol) of 1-dodecanethiol, and stir for 30 minutes.

[0155] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dots consisting of InP core, ZnSe shell and ZnS shell were precipitated by centrifugation. The supernatant was removed.

[0156] Further, toluene was added to the precipitate and dispersed, ethanol was added again, centrifugation was performed, the supernatant was removed, and the precipitate was redispersed in toluene, thus preparing an InP / ZnSe / ZnS dispersion.

[0157] The obtained InP / ZnSe / ZnS toluene dispersion exhibited a peak fluorescence emission wavelength of 535 nm and an internal quantum efficiency of 84%. Furthermore, the fluorescence efficiency of the InP / ZnSe / ZnS toluene dispersion was measured after irradiation with a blue LED light source (As One, HL-36) at a wavelength of 450 nm in an atmospheric environment for 12 hours; the result showed an internal quantum efficiency of 68%.

[0158] (Manufacturing Example 2) 0.033 g (0.20 mmol) of silver acetate (I), 0.058 g (0.20 mmol) of indium acetate, 0.65 mL (2.7 mmol) of 1-dodecylthiol and 4.0 mL of oleylamine were added to a flask. The mixture was heated and stirred at 100 °C under reduced pressure for one hour to degas. Subsequently, the flask was rinsed with nitrogen, heated to 200 °C, and held for 20 minutes to synthesize AgInS2 semiconductor nuclei.

[0159] Next, 0.014 g (0.1 mmol) of zinc chloride was dissolved in 1.0 ml of trioctylphosphine solution and added to a flask heated to 200 °C to passivate the surface of AgInS2 semiconductor nuclei.

[0160] Next, the flask was heated to 230°C, and a 1.25M sulfur / trioctylphosphine solution was prepared. 1.0 mL of this solution was added to the reaction mixture and stirred for one hour. Finally, a zinc precursor solution containing 0.099 g (0.54 mmol) zinc acetate dissolved in 0.24 mL (0.76 mmol) oleic acid and 0.15 mL oleylamine was added to the flask, and the mixture was heated and stirred at 230°C for one hour.

[0161] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dots were precipitated by centrifugation. The supernatant was removed. Toluene was added and dispersed, ethanol was added again and centrifuged to remove the supernatant, thus redispersing the precipitate in toluene, thereby preparing an AgInS2 / ZnS dispersion.

[0162] The obtained AgInS2 / ZnS toluene dispersion exhibited a peak fluorescence emission wavelength of 599 nm and an internal quantum efficiency of 68%. Furthermore, the fluorescence efficiency of the AgInS2 / ZnS dispersion was measured after irradiation with a blue LED light source (As One, HL-36) at 450 nm wavelength in an atmospheric environment for 12 hours; the result showed an internal quantum efficiency of 49%.

[0163] (Formation of metal oxide capping layer) (Manufacturing Example 3) A toluene solution of 10g of 1.0wt% InP / ZnSe / ZnS quantum dots (semiconductor nanoparticles) obtained in Manufacturing Example 1, 110μL of tetraethyl orthosilicate, 50μL of 25% ammonia solution, and 0.010g / 100μL of cetyltrimethylammonium bromide / ethanol solution were mixed and placed in a high-pressure reaction vessel.

[0164] Subsequently, using a microwave synthesis apparatus (Milestone General, flexi WAVE), a SiO2 coating was formed on the InP / ZnSe / ZnS surface by heating at 2450 MHz for 60°C for 5 minutes. After adding ethanol to the obtained nanoparticles, they were centrifuged to allow them to settle, the supernatant was removed, and toluene or octadecene was added, followed by ultrasonic irradiation to redisperse them.

[0165] The internal quantum efficiency of the obtained InP / ZnSe / ZnS / SiO2 toluene dispersion was 81%. Furthermore, the fluorescence efficiency of the InP / ZnSe / ZnS / SiO2 toluene dispersion was measured after irradiation with a blue LED light source (As One, HL-36) at a wavelength of 450 nm in an atmospheric environment for 12 hours; the result showed an internal quantum efficiency of 71%.

[0166] (Manufacturing Example 4) A toluene solution of 10g of 1.0wt% InP / ZnSe / ZnS quantum dots (semiconductor nanoparticles) obtained in Manufacturing Example 1, 0.10g of aluminum isopropoxide, 50μL of 25% ammonia solution, and 0.010g / 100μL of cetyltrimethylammonium bromide / ethanol solution were mixed and placed in a high-pressure reaction vessel.

[0167] Subsequently, using a microwave synthesis apparatus (Milestone General, flexi WAVE), an Al2O3 coating was formed on the InP / ZnSe / ZnS surface by heating at 2450 MHz for 60 °C for 5 minutes. Ethanol was added to the obtained nanoparticles, and they were centrifuged to allow them to settle. The supernatant was removed, and toluene or octadecene was added, followed by ultrasonic irradiation to redisperse them.

[0168] The internal quantum efficiency of the obtained InP / ZnSe / ZnS / Al2O3 toluene dispersion was 83%. Furthermore, the fluorescence efficiency of the InP / ZnSe / ZnS / Al2O3 toluene dispersion was measured after irradiation with a blue LED light source (As One, HL-36) at a wavelength of 450 nm in an atmospheric atmosphere for 12 hours; the result showed an internal quantum efficiency of 72%.

[0169] (Manufacturing Example 5) A toluene solution of 10g of 1.0wt% InP / ZnSe / ZnS quantum dots (semiconductor nanoparticles) obtained in Manufacturing Example 1, 0.16g of zirconium isopropoxide (IV), 50μL of 25% ammonia solution, and 0.010g / 100μL of cetyltrimethylammonium bromide / ethanol solution were mixed and placed in a high-pressure reaction vessel.

[0170] Subsequently, using a microwave synthesis apparatus (Milestone General, flexi WAVE), a ZrO2 coating was formed on the InP / ZnSe / ZnS surface by heating at 2450 MHz for 60°C for 5 minutes. Ethanol was added to the obtained nanoparticles, and they were centrifuged to allow them to settle. The supernatant was removed, and toluene or octadecene was added, followed by ultrasonic irradiation to redisperse them.

[0171] The internal quantum efficiency of the obtained InP / ZnSe / ZnS / ZrO2 toluene dispersion was 83%. Furthermore, the fluorescence efficiency of the InP / ZnSe / ZnS / ZrO2 toluene dispersion was measured after irradiation with a blue LED light source (As One, HL-36) at a wavelength of 450 nm in an atmospheric environment for 12 hours; the result showed an internal quantum efficiency of 73%.

[0172] (Manufacturing Example 6) A toluene solution of 10g of 1.0wt% InP / ZnSe / ZnS quantum dots (semiconductor nanoparticles) obtained in Manufacturing Example 1, 0.14g of tetraisopropoxy titanium, 50μL of 25% ammonia solution, and 0.010g / 100μL of cetyltrimethylammonium bromide / ethanol solution were mixed and placed in a high-pressure reaction vessel.

[0173] Subsequently, using a microwave synthesis reactor (manufactured by Milestone General, flexi WAVE), a TiO2 coating was formed on the InP / ZnSe / ZnS surface by heating at 2450 MHz for 60°C for 5 minutes.

[0174] Ethanol was added to the obtained nanoparticles, and the particles were centrifuged to allow them to settle. The supernatant was removed, and toluene or octadecene was added. The particles were then subjected to ultrasonic irradiation to redisperse them.

[0175] The internal quantum efficiency of the obtained InP / ZnSe / ZnS / TiO2 toluene dispersion was 78%. Furthermore, the fluorescence efficiency of the InP / ZnSe / ZnS / TiO2 toluene dispersion was measured after irradiation with a blue LED light source (As One, HL-36) at a wavelength of 450 nm in an atmospheric environment for 12 hours; the result showed an internal quantum efficiency of 70%.

[0176] (Manufacturing Example 7) A toluene solution of 10g of 1.0wt% AgInS2 / ZnS quantum dots (semiconductor nanoparticles) obtained in Manufacturing Example 2, 0.10g of aluminum isopropoxide, 50μL of 25% ammonia solution, and 0.010g / 100μL of cetyltrimethylammonium bromide / ethanol solution were mixed and placed in a high-pressure reaction vessel.

[0177] Subsequently, using a microwave synthesis apparatus (Milestone General, flexi WAVE), an Al2O3 coating was formed on the AgInS2 / ZnS surface by heating at 2450 MHz for 60 °C for 5 minutes. Ethanol was added to the obtained nanoparticles, and they were precipitated by centrifugation. The supernatant was removed, and toluene or octadecene was added, followed by ultrasonic irradiation to redisperse the nanoparticles.

[0178] The internal quantum efficiency of the obtained AgInS2 / ZnS / Al2O3 toluene dispersion was 64%. Furthermore, the fluorescence efficiency of the AgInS2 / ZnS / Al2O3 toluene dispersion was measured after irradiation with a blue LED light source (As One, HL-36) at a wavelength of 450 nm in an atmospheric atmosphere for 12 hours; the result showed an internal quantum efficiency of 54%.

[0179] (Manufacturing Example 8) A toluene solution of 10g of 1.0wt% AgInS2 / ZnS quantum dots (semiconductor nanoparticles) obtained in Manufacturing Example 2, 0.16g of zirconium isopropoxide (IV), 50μL of 25% ammonia solution, and 0.010g / 100μL of cetyltrimethylammonium bromide / ethanol solution were mixed and placed in a high-pressure reaction vessel.

[0180] Subsequently, using a microwave synthesis apparatus (Milestone General, flexi WAVE), a ZrO2 coating was formed on the AgInS2 / ZnS surface by heating at 2450 MHz for 60°C for 5 minutes. Ethanol was added to the obtained nanoparticles, and they were precipitated by centrifugation. The supernatant was removed, and toluene or octadecene was added, followed by ultrasonic irradiation to redisperse the nanoparticles.

[0181] The internal quantum efficiency of the obtained AgInS2 / ZnS / ZrO2 toluene dispersion was 63%. Furthermore, the fluorescence efficiency of the AgInS2 / ZnS / ZrO2 toluene dispersion was measured after irradiation with a blue LED light source (As One, HL-36) at a wavelength of 450 nm in an atmospheric environment for 12 hours; the result showed an internal quantum efficiency of 53%.

[0182] (Based on surface modification of phosphonic acid derivatives) (Example 1) In a nitrogen atmosphere, 31 mg of hexadecylphosphonic acid (HDPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a hexadecylphosphonic acid solution.

[0183] Furthermore, in a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS / SiO2 octadecene dispersion obtained in Manufacturing Example 3 and 6 ml of hexadecylphosphonic acid solution were added to a three-necked flask.

[0184] Next, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas. Then, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with HDPA on InP / ZnSe / ZnS / SiO2. The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation, removing the supernatant.

[0185] Furthermore, a toluene dispersion of the quantum dot composition was prepared by adding toluene to the precipitate to disperse it, adding ethanol again and centrifuging to remove the supernatant and redispersing it in toluene.

[0186] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 81%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36), and the result was an internal quantum efficiency of 76%.

[0187] (Example 2) In a nitrogen atmosphere, 31 mg of hexadecylphosphonic acid (HDPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a hexadecylphosphonic acid solution.

[0188] Furthermore, under a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS / Al2O3 octadecene dispersion obtained in Manufacturing Example 4 and 6 ml of hexadecylphosphonic acid solution were added to a three-necked flask.

[0189] Next, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas. Then, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with HDPA on InP / ZnSe / ZnS / Al2O3.

[0190] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0191] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 82%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36), and the result showed an internal quantum efficiency of 80%.

[0192] (Example 3) In a nitrogen atmosphere, 31 mg of hexadecylphosphonic acid (HDPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a hexadecylphosphonic acid solution.

[0193] Further, under a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS / ZrO2 octadecene dispersion obtained in Manufacturing Example 5 and 6 ml of hexadecylphosphonic acid solution were added to a three-necked flask. Then, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas.

[0194] Next, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with HDPA on InP / ZnSe / ZnS / ZrO2.

[0195] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0196] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 82%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36), and the result was an internal quantum efficiency of 79%.

[0197] (Example 4) In a nitrogen atmosphere, 31 mg of hexadecylphosphonic acid (HDPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a hexadecylphosphonic acid solution.

[0198] Further, under a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS / TiO2 octadecene dispersion obtained in Manufacturing Example 6 and 6 ml of hexadecylphosphonic acid solution were added to a three-necked flask.

[0199] Next, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas. Then, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with HDPA on InP / ZnSe / ZnS / TiO2.

[0200] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0201] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 78%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36), and the result was an internal quantum efficiency of 77%.

[0202] (Example 5) In a nitrogen atmosphere, 31 mg of hexadecylphosphonic acid (HDPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a hexadecylphosphonic acid solution.

[0203] Furthermore, under a nitrogen atmosphere, 10 g of the 1.0 wt% AgInS2 / ZnS / Al2O3 octadecene dispersion obtained in Manufacturing Example 7 and 6 ml of hexadecylphosphonic acid solution were added to a three-necked flask.

[0204] Next, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas. Then, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with HDPA on AgInS2 / ZnS / Al2O3.

[0205] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0206] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 63%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36); the result showed an internal quantum efficiency of 61%.

[0207] (Example 6) In a nitrogen atmosphere, 31 mg of hexadecylphosphonic acid (HDPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a hexadecylphosphonic acid solution.

[0208] Furthermore, under a nitrogen atmosphere, 10 g of the 1.0 wt% AgInS2 / ZnS / ZrO2 octadecene dispersion obtained in Manufacturing Example 8 and 6 ml of hexadecylphosphonic acid solution were added to a three-necked flask.

[0209] Next, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas. Then, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with HDPA on AgInS2 / ZnS / ZrO2.

[0210] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0211] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 65%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36); the result showed an internal quantum efficiency of 62%.

[0212] (Example 7) In a nitrogen atmosphere, 25 mg of dodecylphosphonic acid (DDPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a dodecylphosphonic acid solution.

[0213] Furthermore, under a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS / Al2O3 octadecene dispersion obtained in Manufacturing Example 4 and 6 ml of dodecylphosphonic acid solution were added to a three-necked flask.

[0214] Next, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas. Then, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with DDPA on InP / ZnSe / ZnS / Al2O3.

[0215] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0216] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 82%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36), and the result was an internal quantum efficiency of 79%.

[0217] (Example 8) In a nitrogen atmosphere, 22 mg of (4-bromobutyl)phosphonic acid (BBPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a (4-bromobutyl)phosphonic acid solution.

[0218] Further, under a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS / Al2O3 octadecene dispersion obtained in Manufacturing Example 4 and 6 ml of (4-bromobutyl)phosphonic acid solution were added to a three-necked flask.

[0219] Next, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas. Then, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with BBPA on InP / ZnSe / ZnS / Al2O3.

[0220] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0221] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 81%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light in an atmospheric environment for 12 hours using a blue LED light source (manufactured by As One, HL-36), and the result was an internal quantum efficiency of 78%.

[0222] (Example 9) In a nitrogen atmosphere, 16 mg of phenylphosphonic acid (PhPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a phenylphosphonic acid (PhPA) solution.

[0223] Further, under a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS / Al2O3 octadecene dispersion obtained in Manufacturing Example 4 and 6 ml of phenylphosphonic acid solution were added to a three-necked flask. Then, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas.

[0224] Next, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with PhPA on InP / ZnSe / ZnS / Al2O3.

[0225] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0226] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 82%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36), and the result was an internal quantum efficiency of 78%.

[0227] (Example 10) In a nitrogen atmosphere, 25 mg of dodecylphosphonic acid (DDPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a dodecylphosphonic acid solution.

[0228] Furthermore, under a nitrogen atmosphere, 10 g of the 1.0 wt% AgInS2 / ZnS / Al2O3 octadecene dispersion obtained in Manufacturing Example 7 and 6 ml of dodecylphosphonic acid solution were added to a three-necked flask.

[0229] Next, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas. Then, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with DDPA on AgInS2 / ZnS / Al2O3.

[0230] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0231] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 63%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36). The result showed an internal quantum efficiency of 60%.

[0232] (Example 11) In a nitrogen atmosphere, 22 mg of (4-bromobutyl)phosphonic acid (BBPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a (4-bromobutyl)phosphonic acid solution.

[0233] Further, under a nitrogen atmosphere, 10 g of the 1.0 wt% AgInS2 / ZnS / Al2O3 octadecene dispersion obtained in Manufacturing Example 7 and 6 ml of (4-bromobutyl)phosphonic acid solution were added to a three-necked flask.

[0234] Next, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas. Then, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with BBPA on AgInS2 / ZnS / Al2O3.

[0235] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0236] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 61%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36); the result showed an internal quantum efficiency of 59%.

[0237] (Example 12) In a nitrogen atmosphere, 22 mg of phenylphosphonic acid (PhPA) was weighed into a 20 ml vial, and 5 ml of toluene and 1 ml of ethanol were added and stirred to prepare a phenylphosphonic acid solution.

[0238] Furthermore, under a nitrogen atmosphere, 10 g of the 1.0 wt% AgInS2 / ZnS / Al2O3 octadecene dispersion obtained in Manufacturing Example 7 and 6 ml of phenylphosphonic acid solution were added to a three-necked flask.

[0239] Next, under reduced pressure, the flask was heated and stirred at 50°C for 10 minutes to degas. Then, the flask was rinsed with nitrogen, heated to 150°C, and stirred for 3 hours to obtain a quantum dot composition modified with PhPA on AgInS2 / ZnS / Al2O3.

[0240] The obtained solution was cooled to room temperature, ethanol was added, and the quantum dot composition was precipitated by centrifugation. The supernatant was then removed. Further, toluene was added to the precipitate to disperse it, ethanol was added again, and centrifugation was performed to remove the supernatant and redisperse it in toluene, thereby preparing a toluene dispersion of the quantum dot composition.

[0241] The internal quantum efficiency of the toluene dispersion of the obtained quantum dot composition was 63%. Furthermore, the fluorescence efficiency of the toluene dispersion of the obtained quantum dot composition was measured after irradiation with 450 nm blue light at atmospheric pressure for 12 hours using a blue LED light source (As One, HL-36). The result showed an internal quantum efficiency of 60%.

[0242] The results above are shown in Table 1.

[0243] [Table 1]

[0244] Regarding the toluene dispersion of quantum dots in Example 1, the toluene dispersion of quantum dots coated with metal oxides in Examples 3-6, and the toluene dispersion of quantum dot compositions coated with oxides and treated with phosphonic acid in Examples 1-4 and 7-9, when comparing the values ​​of internal quantum yield after blue light irradiation, it is shown that one of the quantum dot compositions in Examples 1-4 and 7-9 maintains a high value of internal quantum yield.

[0245] Furthermore, regarding the toluene dispersion of quantum dots in Manufacturing Example 2, the toluene dispersion of quantum dots coated with metal oxides in Manufacturing Examples 7 and 8, and the toluene dispersion of quantum dot compositions coated with oxides and treated with phosphonic acid in Examples 5, 6, 10 to 12, when comparing the values ​​of internal quantum yield after blue light irradiation, one of the quantum dot compositions in Examples 5, 6, 10 to 12 maintained a high value of internal quantum yield.

[0246] The results confirm that quantum dots formed by metal oxide layers and modified with phosphonic acid derivatives suppress the reduction in internal quantum yield caused by blue light irradiation and improve photostability.

[0247] (Preparation of resin composition and wavelength conversion material) (Example 13) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 1. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0248] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0249] The thickness of the obtained wavelength conversion material is 97 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 44%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH (Relative Humidity) for 500 hours was measured, and the internal quantum efficiency was found to be 41%.

[0250] (Example 14) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 2. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0251] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0252] The thickness of the obtained wavelength conversion material is 99 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 47%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 46%.

[0253] (Example 15) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 3. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0254] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0255] The thickness of the obtained wavelength conversion material is 99 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 45%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 44%.

[0256] (Example 16) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 4. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0257] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0258] The thickness of the obtained wavelength conversion material is 99 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 43%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 41%.

[0259] (Example 17) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 5. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0260] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0261] The thickness of the obtained wavelength conversion material is 98 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 33%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 32%.

[0262] (Example 18) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 6. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0263] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0264] The thickness of the obtained wavelength conversion material is 100 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 32%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85 °C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 31%.

[0265] (Example 19) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 7. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0266] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0267] The thickness of the obtained wavelength conversion material is 99 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 47%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 45%.

[0268] (Example 20) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 8. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0269] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0270] The thickness of the obtained wavelength conversion material is 99 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 45%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 43%.

[0271] (Example 21) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 9. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0272] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0273] The thickness of the obtained wavelength conversion material is 98 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 46%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 45%.

[0274] (Example 22) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 10. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0275] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0276] The thickness of the obtained wavelength conversion material is 96 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 33%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 31%.

[0277] (Example 23) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 11. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0278] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0279] The thickness of the obtained wavelength conversion material is 99 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 32%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 30%.

[0280] (Example 24) Wavelength conversion materials were prepared using the quantum dot composition obtained in Example 12. 2.5 g of the above quantum dot composition was mixed with a 20 wt% toluene solution and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA), and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0281] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0282] The thickness of the obtained wavelength conversion material is 99 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 33%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 30%.

[0283] (Comparative Example 1) Wavelength conversion materials were prepared using the quantum dots obtained in Manufacturing Example 1. 2.5 g of a 20 wt% toluene solution of the aforementioned quantum dots and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA) were mixed, and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0284] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0285] The thickness of the obtained wavelength conversion material is 96 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 48%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 27%.

[0286] (Comparative Example 2) Wavelength conversion materials were prepared using the quantum dots obtained in Manufacturing Example 2. 2.5 g of a 20 wt% toluene solution of the aforementioned quantum dots and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA) were mixed, and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0287] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0288] The thickness of the obtained wavelength conversion material is 98 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 34%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 20%.

[0289] (Comparative Example 3) Wavelength conversion materials were prepared using the oxide-coated quantum dots obtained in Manufacturing Example 3. 2.5 g of a 20 wt% toluene solution of the aforementioned quantum dots and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA) were mixed, and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0290] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0291] The thickness of the obtained wavelength conversion material is 97 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 44%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 33%.

[0292] (Comparative Example 4) Wavelength conversion materials were prepared using the oxide-coated quantum dots obtained in Manufacturing Example 4. 2.5 g of a 20 wt% toluene solution of the aforementioned quantum dots and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA) were mixed, and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0293] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0294] The thickness of the obtained wavelength conversion material is 99 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 47%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 36%.

[0295] (Comparative Example 5) Wavelength conversion materials were prepared using the oxide-coated quantum dots obtained in Manufacturing Example 5. 2.5 g of a 20 wt% toluene solution of the aforementioned quantum dots and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA) were mixed, and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0296] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0297] The thickness of the obtained wavelength conversion material is 97 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 46%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 36%.

[0298] (Comparative Example 6) Wavelength conversion materials were prepared using the oxide-coated quantum dots obtained in Manufacturing Example 6. 2.5 g of a 20 wt% toluene solution of the aforementioned quantum dots and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA) were mixed, and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0299] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0300] The thickness of the obtained wavelength conversion material is 99 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 42%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 34%.

[0301] (Comparative Example 7) Wavelength conversion materials were prepared using the oxide-coated quantum dots obtained in Manufacturing Example 7. 2.5 g of a 20 wt% toluene solution of the aforementioned quantum dots and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA) were mixed, and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0302] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0303] The thickness of the obtained wavelength conversion material is 100 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 33%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 23%.

[0304] (Comparative Example 8) Wavelength conversion materials were prepared using the oxide-coated quantum dots obtained in Manufacturing Example 8. 2.5 g of a 20 wt% toluene solution of the aforementioned quantum dots and 5.0 g of acrylic resin (manufactured by DIC: Acrydic BL-616-BA) were mixed, and the solvent was removed under reduced pressure while heating at 60°C with stirring.

[0305] Subsequently, vacuum degassing was performed, and the resin composition layer was coated onto a 50 μm thick polyethylene terephthalate (PET) film using a rod coater. Further, a PET film was laminated onto this resin composition layer. The film was then heated at 60°C for 2 hours and then at 150°C for 4 hours to cure the resin composition layer, thus preparing the wavelength conversion material.

[0306] The thickness of the obtained wavelength conversion material is 98 μm. Furthermore, the internal quantum efficiency of the obtained wavelength conversion material is 32%. Additionally, the fluorescence efficiency of the obtained wavelength conversion material after treatment at 85°C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 24%.

[0307] The results above are shown in Table 2.

[0308] [Table 2]

[0309] In Examples 13 and Comparative Examples 1, 3; Examples 14, 19-21 and Comparative Examples 1, 4; Examples 15 and Comparative Examples 1, 5; Examples 16 and Comparative Examples 1, 6; Examples 17, 22-24 and Comparative Examples 2, 7; Examples 18 and Comparative Examples 2, 8, the internal quantum efficiency values ​​of the wavelength conversion materials prepared for each example were compared after being treated at 85°C and 85%RH for 500 hours. The results confirmed that the wavelength conversion materials of Examples 13-24 using the quantum dot compositions of the present invention formed by a metal oxide layer and surface modified according to phosphonic acid derivatives showed higher internal quantum efficiency values ​​than quantum dots and quantum dots that only form metal oxide layers.

[0310] As described above, the quantum dot composition manufactured in this invention, the resin composition using the quantum dot composition, and the wavelength conversion material used to cure it have been shown to suppress the degradation of fluorescence luminescence efficiency under high temperature and high humidity conditions, even when using quantum dots with low toxicity, and to have high reliability.

[0311] This instruction manual includes the following methods.

[0312] [1]: A quantum dot composition comprising quantum dots that fluoresce upon excitation light, characterized in that the quantum dots are composed of a semiconductor nanoparticle core and a semiconductor nanoparticle shell free of Cd and Pb, the surface of the quantum dots is covered with a metal oxide, and the surface of the quantum dots or the surface of the metal oxide is modified with a phosphonic acid derivative.

[0313] [2]: The quantum dot composition according to [1] above is characterized in that the quantum dot is composed of the semiconductor nanoparticle core and one or more semiconductor nanoparticle shells covering the semiconductor nanoparticle core.

[0314] [3]: The quantum dot composition according to [1] or [2] above is characterized in that the semiconductor nanoparticle core is a single, multiple or mixed crystal selected from ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AgGaS2, AgInS2, AgGaSe2, AgInSe2, CuGaS2, CuGaSe2, CuInS2, CuInSe2, ZnSiP2 and ZnGeP2.

[0315] [4]: The quantum dot composition according to any one of [1] to [3] above is characterized in that the core surface of the semiconductor nanoparticles is passivated by one or more compounds selected from GaCl3, GaI3, GaBr3, ZnCl2, ZnBr2, ZnI2, InCl3, InBr3, InI3, AgCl, AgBr, AgI, KCl, KBr, KI, NaCl, NaBr, NaI, MgCl2, MgBr2, MgI2, CaCl2, CaBr2, CaI2, MnCl2, MnBr2, MnI2, FeCl2, FeBr2, FeI2, CuCl2, CuBr2, CuI2, ZrCl4, ZrBr4, ZrI4, GeCl4, GeBr4, GeI4.

[0316] [5]: The quantum dot composition according to any one of [1] to [4] above, characterized in that the semiconductor nanoparticle shell is a single, multiple or mixed crystal selected from ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs and InSb.

[0317] [6]: The quantum dot composition according to any one of [1] to [5] above is characterized in that the metal oxide is a compound selected from at least one of TiO2, ZnO, Al2O3, SiO2, ZrO2, Fe2O3, MgO, Y2O3, HfO2, CeO2, In2O3, SnO2, WO3, CrO3, Ta2O3, BaTiO3, V2O5, NiO, NbO, Cu2O, CuO, and MoO3.

[0318] [7]: The quantum dot composition according to any one of [1] to [6] above is characterized in that the phosphonic acid derivative is a compound represented by the following formula (I).

[0319] [Chemical Formula 9]

[0320] (In formula (I), R1 is a monovalent organic group having one or more carbon atoms).

[0321] [8]: The quantum dot composition according to [7] above is characterized in that the phosphonic acid derivative is derived from 3-phenyl-2-propenylphosphonic acid, tenofovir, 2-phosphonobutane-1,2,4-tricarboxylic acid, 4-phosphonic benzoic acid, vinylphosphonic acid, n-octylphosphonic acid, (3-bromopropyl)phosphonic acid, (4-bromobutyl)phosphonic acid, (2-bromoethyl)phosphonic acid, (4-bromophenyl)phosphonic acid, 3-phosphonic propionic acid, (4-hydroxyphenyl)phosphonic acid, hexylphosphonic acid, 4-phosphonic butyric acid, propionic acid, (4-aminobenzyl)phosphonic acid, (4-aminophenyl)phosphonic acid, 3-phosphonic benzoic acid, methylphosphonic acid, nonylphosphonic acid, diphenylmethylphosphonic acid, octadecylphosphonic acid, (aminomethyl)phosphonic acid, (2-phenylethyl)phosphonic acid, ethylphosphonic acid, butylphosphonic acid, decylphosphonic acid, dodecylphosphonic acid, ( The selected one or more of the following: 2-chloroethyl)phosphonic acid, 4-methoxyphenylphosphonic acid, hexadecylphosphonic acid, (4-hydroxybenzyl)phosphonic acid, phenylphosphonic acid, (1H,1H,2H,2H-heptadecyl)phosphonic acid, tetradecylphosphonic acid, (1-aminoethyl)phosphonic acid, undecylphosphonic acid, heptylphosphonic acid, 10-carboxydecylphosphonic acid, 11-aminoundecylphosphonic acid·hydrobromide, 11-hydroxyundecylphosphonic acid, 1H,1H,2H,2H-perfluorohexylphosphonic acid, 1H,1H,2H,2H-perfluorooctylphosphonic acid, 1H,1H,2H,2H-perfluorodecylphosphonic acid, 11-{2-[2-(2-methoxyethoxy)ethoxy]ethoxy}undecylphosphonic acid, 12-mercaptodecylphosphonic acid, and [11-(acryloyloxy)undecyl]phosphonic acid.

[0322] [9]: The quantum dot composition according to any one of [1] to [6] above is characterized in that the phosphonic acid derivative is a compound represented by the following formula (II).

[0323] [Chemical Formula 10]

[0324] (In formula (II), R2 is a divalent organic group having one or more carbon atoms).

[0325]

[10] : The quantum dot composition according to [9] above is characterized in that the phosphonic acid derivative is selected from one or more of the following: m-xylene diphosphonic acid, o-xylene diphosphonic acid, methylene diphosphonic acid, alendronic acid, 1,4-butadiene diphosphonic acid, glycine-N,N-bis(methylene phosphonic acid), p-xylene diphosphonic acid, zoledronic acid, 1,3-propylidene diphosphonic acid, 1,5-pentylidene diphosphonic acid, 1,4-phenylene diphosphonic acid, 1,2-ethylidene diphosphonic acid, 1,6-hexylidene diphosphonic acid, minophosphonate, and 1-hydroxyethane-1,1-diphosphonic acid.

[0326]

[11] : The quantum dot composition according to any one of [1] to [6] above is characterized in that the phosphonic acid derivative is a compound represented by the following formula (III).

[0327] [Chemical Formula 11]

[0328] (In formula (III), R3 is a trivalent organic group having one or more carbon atoms).

[0329]

[12] : The quantum dot composition according to

[11] above is characterized in that the phosphonic acid derivative is nitrilotri(methylenephosphonic acid).

[0330]

[13] : The quantum dot composition according to any one of [1] to [6] above is characterized in that the phosphonic acid derivative is a compound represented by the following formula (IV).

[0331] [Chemical Formula 12]

[0332] (In formula (IV), R4 is a divalent organic group having one or more carbon atoms).

[0333]

[14] : The quantum dot composition according to

[13] above is characterized in that the phosphonic acid derivative is N,N,N',N'-ethylenediaminetetra(methylenephosphonic acid).

[0334]

[15] : The quantum dot composition according to [7] above is characterized in that R1 comprises any one of at least one straight-chain or branched alkyl group having one or more carbon atoms, straight-chain or branched alkylene group having one or more carbon atoms, amino group, carboxylic acid group, ethoxy group, bromo group, chloro group, phenolic group, perfluoroalkyl group, hydroxy group, phenyl group, thiol group, acryloyl group, and oligoethylene glycol group.

[0335]

[16] : The quantum dot composition according to [9] above is characterized in that R2 comprises any one of at least one straight-chain or branched alkyl group having one or more carbon atoms, straight-chain or branched alkylene group having one or more carbon atoms, amino group, carboxylic acid group, ethoxy group, bromo group, chloro group, phenolic group, perfluoroalkyl group, hydroxy group, phenyl group, thiol group, acryloyl group, and oligoethylene glycol group.

[0336]

[17] : The quantum dot composition according to

[11] above is characterized in that the R3 comprises any one of at least one straight-chain or branched alkyl group having one or more carbon atoms, straight-chain or branched alkylene group having one or more carbon atoms, amino group, carboxylic acid group, ethoxy group, bromo group, chloro group, phenolic group, perfluoroalkyl group, hydroxy group, phenyl group, thiol group, acryloyl group, and oligoethylene glycol group.

[0337]

[18] : The quantum dot composition according to

[13] above is characterized in that the R4 comprises any one of at least one straight-chain or branched alkyl group having one or more carbon atoms, straight-chain or branched alkylene group having one or more carbon atoms, amino group, carboxylic acid group, ethoxy group, bromo group, chloro group, phenolic group, perfluoroalkyl group, hydroxy group, phenyl group, thiol group, acryloyl group, and oligoethylene glycol group.

[0338]

[19] : A resin composition, characterized in that it is a composition formed by dispersing the quantum dot composition according to any one of [1] to

[18] in a resin.

[0339]

[20] : The resin composition according to

[19] above is characterized in that the resin is selected from at least one resin selected from epoxy resin, acrylic resin, fluorinated resin, silicone resin, carbonate resin and glass resin.

[0340]

[21] : A wavelength conversion material, characterized in that it comprises a cured product of the resin composition according to

[20] above.

[0341] It should be noted that the present invention is not limited to the above embodiments. The above embodiments are illustrative examples, and technical solutions that have the same structure and perform the same effect as those described in the claims of the present invention are all included within the technical scope of the present invention.

Claims

1. A quantum dot composition comprising quantum dots that emit fluorescence upon excitation light, characterized in that, The quantum dot is composed of a semiconductor nanoparticle core and a semiconductor nanoparticle shell that do not contain Cd or Pb. The surface of the quantum dot is covered with a metal oxide, and the surface of the quantum dot or the surface of the metal oxide is modified with a phosphonic acid derivative.

2. The quantum dot composition according to claim 1, characterized in that, The quantum dot is composed of a semiconductor nanoparticle core and one or more semiconductor nanoparticle shells covering the semiconductor nanoparticle core.

3. The quantum dot composition according to claim 1, characterized in that, The semiconductor nanoparticle core is a single, multiple, or mixed crystal selected from ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AgGaS2, AgInS2, AgGaSe2, AgInSe2, CuGaS2, CuGaSe2, CuInS2, CuInSe2, ZnSiP2, and ZnGeP2.

4. The quantum dot composition according to claim 1, characterized in that, The surface of the semiconductor nanoparticle core is passivated by one or more compounds selected from GaCl3, GaI3, GaBr3, ZnCl2, ZnBr2, ZnI2, InCl3, InBr3, InI3, AgCl, AgBr, AgI, KCl, KBr, KI, NaCl, NaBr, NaI, MgCl2, MgBr2, MgI2, CaCl2, CaBr2, CaI2, MnCl2, MnBr2, MnI2, FeCl2, FeBr2, FeI2, CuCl2, CuBr2, CuI2, ZrCl4, ZrBr4, ZrI4, GeCl4, GeBr4, and GeI4.

5. The quantum dot composition according to claim 1, characterized in that, The semiconductor nanoparticle shell is a single, multiple, or mixed crystal selected from ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb.

6. The quantum dot composition according to claim 1, characterized in that, The metal oxide is a compound selected from at least one of TiO2, ZnO, Al2O3, SiO2, ZrO2, Fe2O3, MgO, Y2O3, HfO2, CeO2, In2O3, SnO2, WO3, CrO3, Ta2O3, BaTiO3, V2O5, NiO, NbO, Cu2O, CuO, and MoO3.

7. The quantum dot composition according to claim 1, characterized in that, The phosphonic acid derivative is a compound represented by the following formula (I); [Compound 1] ； In formula (I), R1 is a monovalent organic group having one or more carbon atoms.

8. The quantum dot composition according to claim 7, characterized in that, The phosphonic acid derivatives are derived from 3-phenyl-2-propenylphosphonic acid, tenofovir, 2-phosphonobutane-1,2,4-tricarboxylic acid, 4-phosphonobenzoic acid, vinylphosphonic acid, n-octylphosphonic acid, (3-bromopropyl)phosphonic acid, (4-bromobutyl)phosphonic acid, (2-bromoethyl)phosphonic acid, (4-bromophenyl)phosphonic acid, 3-phosphonopropionic acid, (4-hydroxyphenyl)phosphonic acid, hexylphosphonic acid, 4-phosphonobutyric acid, propionic acid, (4-aminobenzyl)phosphonic acid, (4-aminophenyl)phosphonic acid, 3-phosphonobenzoic acid, methylphosphonic acid, nonylphosphonic acid, diphenylmethylphosphonic acid, octadecylphosphonic acid, (aminomethyl)phosphonic acid, (2-phenylethyl)phosphonic acid, ethylphosphonic acid, butylphosphonic acid, decylphosphonic acid, dodecylphosphonic acid, (2-chloroethyl)phosphonic acid, and 4-methoxyphosphonic acid. The phenylphosphonic acid, hexadecylphosphonic acid, (4-hydroxybenzyl)phosphonic acid, phenylphosphonic acid, (1H,1H,2H,2H-heptadecyl)phosphonic acid, tetradecylphosphonic acid, (1-aminoethyl)phosphonic acid, undecylphosphonic acid, heptylphosphonic acid, 10-carboxydecylphosphonic acid, 11-aminoundecylphosphonic acid·hydrobromide, 11-hydroxyundecylphosphonic acid, 1H,1H,2H,2H-perfluoron-hexylphosphonic acid, 1H,1H,2H,2H-perfluorooctylphosphonic acid, 1H,1H,2H,2H-perfluoron-decylphosphonic acid, 11-{2-[2-(2-methoxyethoxy)ethoxy]ethoxy}undecylphosphonic acid, 12-mercaptodecylphosphonic acid, and [11-(acryloyloxy)undecyl]phosphonic acid are selected from one or more of these.

9. The quantum dot composition according to claim 1, characterized in that, The phosphonic acid derivative is a compound represented by the following formula (II); [Compound 2] ； In formula (II), R2 is a divalent organic group having one or more carbon atoms.

10. The quantum dot composition according to claim 9, characterized in that, The phosphonic acid derivative is selected from one or more of the following: m-xylene diphosphonic acid, o-xylene diphosphonic acid, methylene diphosphonic acid, alendronic acid, 1,4-butadiene diphosphonic acid, glycine-N,N-bis(methylene diphosphonic acid), p-xylene diphosphonic acid, zoledronic acid, 1,3-propylidene diphosphonic acid, 1,5-pentylidene diphosphonic acid, 1,4-phenylene diphosphonic acid, 1,2-ethylidene diphosphonic acid, 1,6-hexylidene diphosphonic acid, minophosphonate, and 1-hydroxyethane-1,1-diphosphonic acid.

11. The quantum dot composition according to claim 1, characterized in that, The phosphonic acid derivative is a compound represented by the following formula (III); [Chemical Formula 3] ； In formula (III), R3 is a trivalent organic group having one or more carbon atoms.

12. The quantum dot composition according to claim 11, characterized in that, The phosphonic acid derivative is tris(methylenephosphonic acid).

13. The quantum dot composition according to claim 1, characterized in that, The phosphonic acid derivative is a compound represented by the following formula (IV); [Chemical Formula 4] ； In formula (IV), R4 is a divalent organic group having one or more carbon atoms.

14. The quantum dot composition according to claim 13, characterized in that, The phosphonic acid derivative is N,N,N',N'-ethylenediaminetetra(methylenephosphonic acid).

15. The quantum dot composition according to claim 7, characterized in that, R1 comprises any one of the following: a straight-chain or branched alkyl group having one or more carbon atoms, a straight-chain or branched alkylene group having one or more carbon atoms, an amino group, a carboxylic acid group, an ethoxy group, a bromide group, a chloro group, a phenolic group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

16. The quantum dot composition according to claim 9, characterized in that, The R2 comprises any one of the following: a straight-chain or branched alkyl group having one or more carbon atoms, a straight-chain or branched alkylene group having one or more carbon atoms, an amino group, a carboxylic acid group, an ethoxy group, a bromo group, a chloro group, a phenolic group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

17. The quantum dot composition according to claim 11, characterized in that, The R3 comprises any one of the following: a straight-chain or branched alkyl group having one or more carbon atoms; a straight-chain or branched alkylene group having one or more carbon atoms; an amino group; a carboxylic acid group; an ethoxy group; a bromo group; a chloro group; a phenolic group; a perfluoroalkyl group; a hydroxyl group; a phenyl group; a thiol group; an acryloyl group; and an oligoethylene glycol group.

18. The quantum dot composition according to claim 13, characterized in that, The R4 comprises any one of the following: a straight-chain or branched alkyl group having one or more carbon atoms; a straight-chain or branched alkylene group having one or more carbon atoms; an amino group; a carboxylic acid group; an ethoxy group; a bromo group; a chloro group; a phenolic group; a perfluoroalkyl group; a hydroxyl group; a phenyl group; a thiol group; an acryloyl group; and a polyethylene glycol group.

19. A resin composition, characterized in that, It is a composition formed by dispersing the quantum dot composition according to any one of claims 1 to 18 in a resin.

20. The resin composition according to claim 19, characterized in that, The resin is selected from at least one resin selected from epoxy resin, acrylic resin, fluorinated resin, silicone resin, carbonate resin, and glass resin.

21. A wavelength conversion material, characterized in that, A cured product comprising the resin composition according to claim 20.

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