Quantum dot composition, resin composition using same, and wavelength conversion material

Abstract

The present invention is a quantum dot composition containing a quantum dot that emits fluorescence by excitation light, characterized in that the quantum dot is composed of a semiconductor nanoparticle core not containing Cd or Pb and a semiconductor nanoparticle shell, and the surface of the quantum dot is modified with a phosphonic acid derivative. As a result, provided are: a quantum dot composition in which the deterioration of fluorescence emission efficiency is suppressed; a resin composition using the quantum dot composition; and a wavelength conversion material.

Description

Technical Field

[0001] The present invention relates to a quantum dot composition, a resin composition using the quantum dot composition, and a wavelength conversion material. Background Art

[0002] Excitons generated by light absorption in quantum dots composed of semiconductor particles with a nanoscale particle size are confined in a nanoscale space. Therefore, the energy levels of the semiconductor nanoparticles are discrete, and in addition, their band gaps depend on the particle size. Therefore, quantum dots have a high fluorescence emission efficiency and a sharp emission spectrum. In addition, due to the characteristic that the band gap changes with the particle size, they have the characteristic of being able to control the emission wavelength, and are expected to be used as wavelength conversion materials for solid-state lighting or displays (Patent Document 1).

[0003] As quantum dots exhibiting excellent fluorescence emission characteristics, quantum dots containing Cd and Pb can be cited. However, Cd and Pb are highly toxic to humans and the environment. Therefore, their use is being discussed for restriction around the world, including the RoHS directive of the European Union. Therefore, research is being conducted on quantum dots that do not contain these toxic elements.

[0004] In addition, as a method for mounting quantum dots as wavelength conversion materials, a method has been proposed in which quantum dots are dispersed in a resin material, and a resin composition containing the quantum dots is laminated with a transparent film, and then assembled in a backlight unit in the form of a wavelength conversion film (Patent Document 2).

[0005] However, since quantum dots have a small particle size in the nanoscale, they have a large specific surface area, high surface energy, and are surface active, and thus are prone to becoming unstable. Therefore, surface defects are likely to occur due to dangling bonds or oxidation reactions on the surface of the quantum dots, which can cause deterioration of the fluorescence emission characteristics. It is known that the currently obtained quantum dots have problems in terms of such stability, and the emission characteristics deteriorate due to heat, humidity, light excitation, etc.

[0006] In order to prevent the above deterioration, organic ligands called ligands are coordinated on the surface of the quantum dots after synthesis. Through the coordination of this ligand, it is possible to improve the dispersibility in a solvent or resin while suppressing the deterioration of the fluorescence emission efficiency by passivating defects.

[0007] However, if an inappropriate ligand is not selected for the surface of the quantum dots, the ligand will detach from the surface of the quantum dots due to external influences such as heat or light irradiation, resulting in deterioration of the fluorescence emission efficiency.

[0008] In the case of being used for a display, temporal changes in the fluorescence emission efficiency of quantum dots can cause defects such as color unevenness, emission unevenness, and dead pixels. Therefore, the stability of quantum dots is an important issue.

[0009] In view of the above problems, methods for covering the surface of quantum dots with polymers or inorganic oxides, etc. (Patent Document 3); methods for improving the stability of quantum dots by using oxygen and a gas barrier film with low moisture permeability (Patent Document 4) were studied.

[0010] However, in the above process of covering the surface of quantum dots for improving stability, it is impossible to maintain the fluorescence emission efficiency of quantum dots, and the problem that characteristic degradation occurs becomes a problem. In addition, for the stabilization achieved by the gas barrier film, there is also a problem that degradation due to the diffusion of oxygen / water vapor from the film end face will occur. Further, in applications such as tablet computers and smartphones, thinning of the wavelength conversion film is required, but generally the gas barrier film has a thickness of about 20 to 200 μm, and in order to protect both sides of the film, the thickness is at least 40 μm or more, so there is a limit to reducing the thickness of the wavelength conversion film.

[0011] Further, a method has also been proposed in which instead of forming a wavelength conversion film from quantum dots, a color filter is formed therefrom to directly convert blue excitation light into green and red (Patent Document 5). When quantum dots are used as a color filter, it is impossible to use a gas barrier film or the like as in the aforementioned wavelength conversion film, and the degradation of the fluorescence emission efficiency of quantum dots due to the curing of the quantum dot composition and its subsequent manufacturing process, as well as long-term use, becomes an important problem.

[0012] Prior Art Documents

[0013] Patent Documents

[0014] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2012-022028

[0015] Patent Document 2: Japanese Patent Application Laid-Open No. 2013-544018

[0016] Patent Document 3: International Publication No. 2011 / 081037

[0017] Patent Document 4: Japanese Patent No. 5900720

[0018] Patent Document 5: Japanese Unexamined Patent Application Publication No. 2018-109141 Summary of the Invention

[0019] (I) Technical Problem to be Solved

[0020] Therefore, an object of the present invention is to provide a quantum dot composition in which degradation of fluorescence emission efficiency is suppressed, a resin composition using the quantum dot composition, and a wavelength conversion material.

[0021] (II) Technical Solution

[0022] In order to solve the above technical problems, the present invention provides a quantum dot composition, which is a quantum dot composition containing quantum dots that emit fluorescence upon excitation by light. The quantum dots are composed of a semiconductor nanoparticle core that does not contain Cd or Pb and a semiconductor nanoparticle shell, and the surface of the quantum dots is modified with a phosphonic acid derivative.

[0023] According to this quantum dot composition, it can be composed of quantum dots with low toxicity, and the deterioration of fluorescence emission efficiency can be inhibited.

[0024] At this time, it is preferred that the quantum dots are composed of the semiconductor nanoparticle core and one or more semiconductor nanoparticle shells that coat the semiconductor nanoparticle core.

[0025] According to this quantum dot composition, the deterioration of fluorescence emission efficiency can be further inhibited.

[0026] At this time, it is preferred that the semiconductor nanoparticle core is one, more than one or a 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] According to this quantum dot composition, it is preferred in terms of fluorescence emission characteristics and stability.

[0028] At this time, it is preferred that the semiconductor nanoparticle shell is one, more than one or a mixed crystal selected from ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs and InSb.

[0029] According to this quantum dot composition, it is preferred in terms of the improvement of fluorescence emission efficiency and stability.

[0030] At this time, it is preferred that the phosphonic acid derivative is represented by the following formula (I).

[0031] [Chemical formula 1]

[0032]

[0033] In formula (I), R1 is a monovalent organic group having one or more carbon atoms.

[0034] According to this quantum dot composition, the deterioration of fluorescence emission efficiency can be inhibited and the stability can be improved.

[0035] At this time, it is preferable that the phosphonic acid derivative is one or more selected from 3-phenyl-2-propenylphosphonic acid, Tenofovir, 2-phosphonobutane-1,2,4-tricarboxylic 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, propylphosphonic 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-methoxyphenylphosphonic acid, hexadecylphosphonic acid, (4-hydroxybenzyl)phosphonic acid, phenylphosphonic acid, (1H,1H,2H,2H-heptadecafluorodecyl)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.

[0036] The quantum dot composition of the present invention can use the above phosphonic acid derivative.

[0037] In addition, at this time, it is preferable that the phosphonic acid derivative is represented by the following formula (II).

[0038] [Chemical formula 2]

[0039]

[0040] In formula (II), R2 is a divalent organic group having one or more carbon atoms.

[0041] According to this quantum dot composition, deterioration of fluorescence emission efficiency can be suppressed and stability can be improved.

[0042] At this time, it is preferable that the phosphonic acid derivative is one or more selected from m-xylene diphosphonic acid, o-xylene diphosphonic acid, methylene diphosphonic acid, 4-phosphonobenzoic acid, alendronic acid, 1,4-butane diphosphonic acid, glycine-N,N-bis(methylenephosphonic acid), p-xylene diphosphonic acid, zoledronic acid, 1,3-propylene diphosphonic acid, 1,5-pentylene diphosphonic acid, 1,4-phenylene diphosphonic acid, 1,2-ethylene diphosphonic acid, 1,6-hexylene diphosphonic acid, minodronic acid, and 1-hydroxyethane-1,1-diphosphonic acid.

[0043] The quantum dot composition of the present invention can use the above phosphonic acid derivative.

[0044] In addition, at this time, it is preferable that the phosphonic acid derivative is represented by the following formula (III).

[0045] [Chemical formula 3]

[0046]

[0047] In formula (III), R3 is a trivalent organic group having one or more carbon atoms.

[0048] According to this quantum dot composition, deterioration of fluorescence emission efficiency can be suppressed and stability can be improved.

[0049] At this time, it is preferable that the phosphonic acid derivative is nitrilotris(methylenephosphonic acid).

[0050] The quantum dot composition of the present invention can use the above phosphonic acid derivative.

[0051] In addition, at this time, it is preferable that the phosphonic acid derivative is represented by the following formula (IV).

[0052] [Chemical formula 4]

[0053]

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

[0055] According to this quantum dot composition, deterioration of fluorescence emission efficiency can be suppressed and stability can be improved.

[0056] At this time, it is preferable that the phosphonic acid derivative is N,N,N’,N’-ethylenediaminetetra(methylenephosphonic acid).

[0057] The quantum dot composition of the present invention can use the above phosphonic acid derivative.

[0058] At this time, it is preferable that R1, R2, R3 and R4 include at least any one or more of a linear or branched alkyl group having one or more carbon atoms, a linear 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 phenol group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group and an oligoethylene glycol group.

[0059] The quantum dot composition of the present invention can use the above phosphonic acid derivative.

[0060] In addition, the present invention provides a resin composition obtained by dispersing the above quantum dot composition in a resin.

[0061] According to the resin composition, a resin composition is obtained in which the deterioration of the fluorescence emission efficiency is suppressed.

[0062] At this time, it is preferable that the resin is at least one selected from epoxy resins, acrylic resins, fluorine resins, silicone resins, carbonate resins, and glass.

[0063] The resin composition of the present invention can use the above resin.

[0064] In addition, the present invention provides a wavelength conversion material using a cured product of the above resin composition.

[0065] According to the wavelength conversion material, the deterioration of the fluorescence emission efficiency is suppressed and the reliability is increased.

[0066] (III) Beneficial Effects

[0067] As described above, according to the present invention, a quantum dot composition, a resin composition using the quantum dot composition, and a wavelength conversion material in which the deterioration of the fluorescence emission efficiency is suppressed can be provided. Detailed Embodiments

[0068] As described above, there is a technical problem of preparing a quantum dot composition in which the deterioration of the fluorescence emission efficiency is suppressed using quantum dots with low toxicity.

[0069] The inventors of the present application repeatedly conducted in-depth research on the above technical problems. As a result, it was found that the deterioration of the fluorescence emission efficiency can be suppressed by a quantum dot composition, and thus the present invention was completed. The quantum dot composition is a composition containing quantum dots that emit fluorescence by excitation light, and is characterized in that the quantum dots are composed of a semiconductor nanoparticle core and a semiconductor nanoparticle shell that do not contain Cd and Pb, and the surface of the quantum dots is modified with a phosphonic acid derivative.

[0070] That is, the present invention is a quantum dot composition, which is a quantum dot composition containing quantum dots that emit fluorescence by excitation light, the quantum dots are composed of a semiconductor nanoparticle core and a semiconductor nanoparticle shell that do not contain Cd or Pb, and the surface of the quantum dots is modified with a phosphonic acid derivative.

[0071] Hereinafter, embodiments of the present invention will be described. However, in the present invention, the composition and type of the quantum dots and the phosphonic acid derivative, and the production method are not limited to the following embodiments.

[0072] [Quantum Dots]

[0073] The structure of the quantum dots in the present invention is not particularly limited as long as it is composed of a semiconductor nanoparticle core and a semiconductor nanoparticle shell. According to such quantum dots, the fluorescence emission characteristics and stability are excellent. For core / shell structured semiconductor nanoparticles in which nanosized semiconductor particles are used as the core and semiconductor particles having a bandgap larger than that of the core and a low lattice mismatch are used as the shell, since the excitons generated by the shell are confined inside the core particles, the fluorescence emission efficiency increases, and since the surface of the core is covered by the shell, the stability increases.

[0074] In addition, it is preferable that the quantum dots are composed of the semiconductor nanoparticle core and one or more semiconductor nanoparticle shells coating the semiconductor nanoparticle core. According to such a quantum dot composition, the deterioration of the fluorescence emission efficiency can be further suppressed.

[0075] As the material of the semiconductor nanoparticle core of the core / shell semiconductor nanoparticles, from the perspective of toxicity, as long as it does not contain elements such as Cd or Pb, there is no particular limitation, and for example, materials selected from the group consisting of II-VI group compounds, III-V group compounds, I-III-VI group compounds, II-IV-V group compounds, and their alloys or mixed crystals can be used. Specifically, those 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, or a mixed crystal thereof can be cited. Among these materials, from the viewpoints of fluorescence emission characteristics and stability, ZnSe, ZnTe, and InP are particularly preferable.

[0076] As the material of the semiconductor nanoparticle shell, from the perspective of toxicity, as long as it does not contain elements such as Cd or Pb, there is no particular limitation, and materials having a larger bandgap and a lower lattice mismatch compared to the core material are preferable, and materials selected from the group consisting of alloys and mixed crystals of II-VI group compounds and III-V group compounds can be used. Specifically, as the shell material, those selected from ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb, or a mixed crystal thereof can be used. Among these materials, from the viewpoints of improvement of fluorescence emission efficiency and stability, ZnSe and ZnS are particularly preferable.

[0077] There are various methods for manufacturing semiconductor nanoparticles, such as the liquid phase method and the gas phase method, but there is no particular limitation in the present invention. From the perspective of exhibiting high fluorescence emission efficiency, semiconductor nanoparticles obtained by using the hot soap method or the hot injection method in which precursor species are reacted at a high temperature in a non-polar solvent with a high boiling point are preferably used.

[0078] In addition, in order to reduce surface defects, it is preferable that organic ligands called ligands are coordinated on the surface of the quantum dots during and after synthesis.

[0079] From the perspective of suppressing the aggregation of quantum dots, it is preferable that the ligand contains an aliphatic hydrocarbon. Examples of such ligands include oleic acid, stearic acid, palmitic acid, myristic acid, lauric acid, capric acid, octanoic acid, oleylamine, stearylamine, dodecylamine, decylamine, octylamine, octadecanethiol, hexadecanethiol, tetradecanethiol, dodecanethiol, decanethiol, octanethiol, trioctylphosphine, trioctyloxidephosphine, triphenylphosphine, triphenyloxidephosphine, tributylphosphine, and tributyloxidephosphine. These ligands can be used alone or in combination of multiple kinds.

[0080] Furthermore, the surface of the quantum dots may also have a coating layer of a polymer or an inorganic molecule, and its structure is not limited. In the case of having a coating layer, its thickness can be appropriately selected according to the purpose. The thickness of the coating layer is not particularly limited, but when the particle size of the quantum dots is 100 nm or less, the decrease in dispersibility can be further suppressed, and as a result, the decrease in light transmittance and aggregation can be further suppressed. Therefore, a thickness that makes the particle size of the quantum dots about 100 nm or less is preferable.

[0081] Examples of the coating layer include polymers such as polyvinyl alcohol, polyvinylpyrrolidone, poly(silsesquioxane), poly(methyl methacrylate), polyacrylonitrile, and polyethylene glycol; and inorganic molecules such as silica, alumina, titanium dioxide, zirconium oxide, zinc oxide, gallium oxide, silicon nitride, and gallium nitride.

[0082] [Phosphonic acid derivative]

[0083] The surface modifier of the quantum dots useful in the present invention is a phosphonic acid derivative, and the quantum dot composition in this specification is composed of the above-mentioned quantum dots and a phosphonic acid derivative that modifies the surface of the quantum dots.

[0084] "Modification" in this specification means a state of bonding to the surface by contacting the surface of the quantum dots with a phosphonic acid derivative. The bonding of the phosphonic acid derivative to the surface of the quantum dots achieved by "modification" includes both local and entire surface cases, and it means a state of bonding to at least a part of the surface.

[0085] The "bonding" described above can be physical adsorption or chemical bonding. For example, it broadly represents covalent bonds, ionic bonds, hydrogen bonds, or a combination thereof.

[0086] In addition, as an example, the quantum dot composition can also be in a state where an organic ligand that was attached to the surface of the quantum dots during synthesis coexists with a phosphonic acid derivative.

[0087] The type of the phosphonic acid derivative is not particularly limited. Preferably, in addition to having one or more groups for bonding to the surface of the quantum dots, it also has one or more groups that act on the compatibility with a solvent or a resin or the stability of the quantum dots.

[0088] The chemical structure of the phosphonic acid derivative is not particularly limited. For example, the structure of the compound is preferably a structure represented by the following formulas (I), (II), (III), and (IV).

[0089] [Chemical formula 5]

[0090]

[0091] (In formula (I), R1 is a monovalent organic group having one or more carbon atoms.)

[0092] [Chemical formula 6]

[0093]

[0094] (In formula (II), R2 is a divalent organic group having one or more carbon atoms.)

[0095] [Chemical formula 7]

[0096]

[0097] (In formula (III), R3 is a trivalent organic group having one or more carbon atoms.)

[0098] [Chemical formula 8]

[0099]

[0100] (In formula (IV), R4 is a divalent organic group having one or more carbon atoms.)

[0101] In certain embodiments of the compounds of formulas (I) to (IV), it is preferred that R1 to R4 include at least any one or more of a linear or branched alkyl group having one or more carbon atoms, a linear 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 phenol group, a perfluoroalkyl group, a hydroxy group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

[0102] As formula (I), specifically, 3-phenyl-2-propenylphosphonic acid, tenofovir, 2-phosphonobutane-1,2,4-tricarboxylic 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, propylphosphonic 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-methoxyphenylphosphonic acid, hexadecylphosphonic acid, (4-hydroxybenzyl)phosphonic acid, phenylphosphonic acid, (1H,1H,2H,2H-heptadecafluorodecyl)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 can be enumerated.

[0103] As formula (II), specifically, m-xylenediphosphonic acid, o-xylenediphosphonic acid, methylenediphosphonic acid, 4-phosphonobenzoic acid, alendronic acid, 1,4-butanediphosphonic acid, glycine-N,N-bis(methylenephosphonic acid), p-xylenediphosphonic acid, zoledronic acid, 1,3-propylenediphosphonic acid, 1,5-pentylenediphosphonic acid, 1,4-phenylenediphosphonic acid, 1,2-ethylenediphosphonic acid, 1,6-hexylenediphosphonic acid, minodronic acid, and 1-hydroxyethane-1,1-diphosphonic acid can be enumerated.

[0104] As formula (III), specifically, nitrilotris(methylenephosphonic acid) can be enumerated.

[0105] As formula (IV), specifically, N,N,N',N'-ethylenediaminetetra(methylenephosphonic acid) can be enumerated.

[0106] The above phosphonic acid derivatives can be used alone or in combination of two or more.

[0107] When the above phosphonic acid derivatives are used to modify the surface of quantum dots, the heating temperature is not particularly limited. For efficient modification, the heating temperature is preferably in the range of 50 to 300 °C, more preferably in the range of 80 °C to 240 °C. If within this range, the surface of quantum dots can be modified more efficiently.

[0108] Regarding the addition amount of the phosphonic acid derivative as the above surface modifier, there is no particular limitation as long as it is within the range where the phosphonic acid derivative can modify the surface of the quantum dots. For example, from the perspective that when the surface modifier is at a high concentration, the quantum dots aggregate with each other or the phosphonic acid derivative precipitates, and when it is at a low concentration, the effect on the modification of the quantum dot surface becomes insufficient, for example, relative to the weight of the solid component of the quantum dots, the added weight of the surface modifier is preferably in the range of 0.01 to 30 wt%, more preferably in the range of 0.1 to 15 wt%.

[0109] [Quantum dot composition]

[0110] In the quantum dot composition in which the above phosphonic acid derivative modifies the surface of the quantum dots, the defects on the surface of the quantum dots are passivated, thereby suppressing the deterioration of the fluorescence emission efficiency and improving the stability.

[0111] [Resin composition]

[0112] In addition, it can be used as a resin composition formed by dispersing the above quantum dot composition in a resin. The resin material is not particularly limited, and a resin material that does not cause aggregation of the quantum dot composition and deterioration of the fluorescence emission efficiency is preferred. For example, at least one selected from epoxy resins, acrylic resins, fluorine resins, silicone resins, carbonate resins, and glass can be cited.

[0113] In order to improve the fluorescence emission efficiency, these resin compositions preferably have a high transmittance, and particularly preferably a transmittance of 80% or more.

[0114] In addition, the concentration of the quantum dots contained in the resin composition is not particularly limited and can be appropriately adjusted according to the film thickness, the emission efficiency of the quantum dots, and the characteristics of the target wavelength conversion material.

[0115] In addition, substances other than the quantum dot composition may also be contained in the resin composition. Fine particles such as silica, zirconia, alumina, and titanium dioxide as light scatterers may be contained, and inorganic phosphors and organic phosphors may be contained. As inorganic phosphors, YAG, LSN, LYSN, CASN, SCASN, KSF, CSO, β-SIALON, GYAG, LuAG, SBCA, etc. can be exemplified, and as organic phosphors, perylene derivatives, anthraquinone derivatives, anthracene derivatives, phthalocyanine derivatives, cyanine derivatives, dioxane derivatives, benzoxazine ketone derivatives, coumarin derivatives, quinophthalone derivatives, benzoxazole derivatives, pyrazoline derivatives, etc. can be exemplified.

[0116] [Wavelength conversion material]

[0117] In addition, the present invention provides a wavelength conversion material using a cured product of the above resin composition. The wavelength conversion material can be used directly or processed. As one embodiment, a wavelength conversion film in which a quantum dot composition is dispersed in a resin by curing after being processed into a sheet can be cited.

[0118] The manufacturing method of the wavelength conversion material is not particularly limited. For example, a wavelength conversion material can be obtained by coating a resin composition in which a quantum dot composition is dispersed in a resin on a transparent film such as PET or polyimide, curing it, and performing lamination processing.

[0119] Coating of the transparent film can be carried out by a spraying method such as spraying or inkjet; spin coating, bar coater, or blade coating method, and a resin layer is formed by coating. In addition, the thickness of the resin layer and the transparent film is not particularly limited and can be appropriately selected according to the use. For such a wavelength conversion material, deterioration of the fluorescence emission efficiency is suppressed and the reliability is increased.

[0120] Examples

[0121] Hereinafter, the present invention will be specifically described with reference to production examples, examples, and comparative examples, but the present invention is not limited thereto.

[0122] (Evaluation of Luminescence Characteristics)

[0123] In the production examples, examples, and comparative examples, for the evaluation of the fluorescence emission characteristics of the quantum dots, quantum dot composition, and wavelength conversion material, a quantum efficiency measurement system (QE-2100) manufactured by Otsuka Electronics Co., Ltd. was used to measure the fluorescence emission efficiency (internal quantum efficiency) at an excitation wavelength of 450 nm.

[0124] (Manufacture of Quantum Dots)

[0125] (Production Example 1)

[0126] 0.070 g (0.24 mmol) of indium acetate, 0.256 g (0.72 mmol) of palmitic acid, and 4.0 mL of 1-octadecene were added to a flask, and while heating and stirring under reduced pressure at 100 °C to dissolve them, degassing was carried out for 1 hour. After cooling the flask to room temperature, nitrogen gas was purged, and 0.50 mL (0.17 mmol) of a 10 vol% tris(trimethylsilyl)phosphine / octadecene solution was added to the flask. By heating the flask to 300 °C and stirring for 20 minutes, InP semiconductor core particles were synthesized. Then, after cooling the flask to 200 °C, 4.0 mL (1.2 mmol) of a 0.30 M zinc stearate / octadecene solution was added and stirred for 30 minutes. Then, 0.60 mL (0.90 mmol) of a 1.5 M trioctylphosphine selenide solution was added to the flask and stirred for 30 minutes. Next, after cooling the flask to room temperature, 0.22 g (1.1 mmol) of zinc acetate was added, and while heating and stirring under reduced pressure at 100 °C to dissolve it, degassing was carried out for 1 hour. After purging nitrogen gas in the flask, it was heated to 230 °C, 0.48 mL (2.0 mmol) of 1-dodecanethiol was added and stirred for 30 minutes. The resulting solution was cooled to room temperature, ethanol was added, and centrifugation was carried out to precipitate quantum dots composed of an InP core, a ZnSe shell, and a ZnS shell and remove the supernatant. Then, to the precipitate, toluene was added and dispersed, ethanol was added again, and centrifugation was carried out to remove the supernatant and redisperse it in toluene or octadecene, thereby preparing an InP / ZnSe / ZnS dispersion. The peak wavelength of the fluorescence emission of the obtained InP / ZnSe / ZnS toluene dispersion was 534 nm, and the internal quantum efficiency was 76%. In addition, after irradiating the InP / ZnSe / ZnS toluene dispersion with blue light having a wavelength of 450 nm for 12 hours using a blue LED light source (manufactured by AS ONE Corporation., HL-36) in an atmospheric atmosphere, the fluorescence emission efficiency was measured, and the internal quantum efficiency was 62%.

[0127] (Production Example 2)

[0128] Add 0.033 g (0.20 mmol) of silver(I) acetate, 0.058 g (0.20 mmol) of indium acetate, 0.65 mL (2.7 mmol) of 1-dodecanethiol, and 4.0 mL of oleylamine into a flask, heat and stir under reduced pressure at 100 °C for 1 hour for degassing. Then, purge nitrogen gas into the flask, heat to 200 °C, and hold for 20 minutes. Next, after heating the flask to 230 °C, prepare a 1.25 M sulfur / trioctylphosphine solution, add 1.0 mL of this sulfur / trioctylphosphine solution to the reaction solution, and stir for 1 hour. Finally, add 0.066 g (0.36 mmol) of zinc acetate, 0.24 mL (0.76 mmol) of oleic acid, and 0.15 mL of oleylamine into the flask, and heat and stir at 230 °C for 1 hour. Cool the obtained solution to room temperature, add ethanol, and perform centrifugation to precipitate the quantum dots and remove the supernatant. Then add toluene and disperse it, add ethanol again for centrifugation and remove the supernatant, and disperse it again in toluene or octadecene to prepare an AgInS2 / ZnS dispersion. The peak fluorescence emission wavelength of the obtained AgInS2 / ZnS toluene dispersion is 597 nm, and the internal quantum efficiency is 56%. In addition, after irradiating the obtained AgInS2 / ZnS toluene dispersion with blue light of wavelength 450 nm for 12 hours using a blue LED light source (manufactured by AS ONE Corporation., HL-36) in an atmospheric atmosphere, the fluorescence emission efficiency was measured, and the internal quantum efficiency was 38%.

[0129] (Surface modification based on phosphonic acid derivatives)

[0130] (Example 1)

[0131] Under a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS octadecene dispersion obtained in Production Example 1 and 31 mg of cetylphosphonic acid were added into a three-necked flask. Subsequently, while heating and stirring the flask at 120 °C under reduced pressure to dissolve them, degassing was carried out for 30 minutes. Nitrogen was purged into the flask, heated to 230 °C and stirred for 30 minutes, thereby obtaining a quantum dot composition in which the surface of the quantum dots was modified with cetylphosphonic acid. The obtained solution was cooled to room temperature, ethanol was added, and centrifugation was carried out, thereby precipitating the quantum dot composition and removing the supernatant. Then, to the precipitate, toluene was added and dispersed, ethanol was added again and centrifugation was carried out, the supernatant was removed and dispersed again in toluene, thereby preparing a toluene dispersion of the quantum dot composition. The internal quantum efficiency of the obtained quantum dot composition was 74%. After irradiating the toluene dispersion of the quantum dot composition with blue light having a wavelength of 450 nm for 12 hours using a blue LED light source (manufactured by ASONE Corporation., HL-36) under an atmospheric atmosphere, the fluorescence emission efficiency was measured, and as a result, the internal quantum efficiency was 71%.

[0132] (Example 2)

[0133] Under a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS octadecene dispersion obtained in Production Example 1 and 27 mg of 10-carboxydecylphosphonic acid were added into a three-necked flask. Subsequently, while heating and stirring the flask at 120 °C under reduced pressure to dissolve them, degassing was carried out for 30 minutes. Nitrogen was purged into the flask, heated to 230 °C and stirred for 30 minutes, thereby obtaining a quantum dot composition in which the surface of the quantum dots was modified with 10-carboxydecylphosphonic acid. The obtained solution was cooled to room temperature, ethanol was added, and centrifugation was carried out, thereby precipitating the quantum dot composition and removing the supernatant. Then, to the precipitate, toluene was added and dispersed, ethanol was added again and centrifugation was carried out, the supernatant was removed and dispersed again in toluene, thereby preparing a toluene dispersion of the quantum dot composition. The internal quantum efficiency of the obtained quantum dot composition was 72%. After irradiating the toluene dispersion of the quantum dot composition with blue light having a wavelength of 450 nm for 12 hours using a blue LED light source (manufactured by AS ONE Corporation., HL-36) under an atmospheric atmosphere, the fluorescence emission efficiency was measured, and as a result, the internal quantum efficiency was 70%.

[0134] (Example 3)

[0135] Under a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS octadecene dispersion obtained in Production Example 1, 31 mg of cetylphosphonic acid, and 22 mg of (4-bromobutyl)phosphonic acid were added into a three-necked flask. Subsequently, while heating and stirring the flask under reduced pressure at 120 °C to dissolve them, degassing was carried out for 30 minutes. Nitrogen was purged into the flask, heated to 230 °C and stirred for 30 minutes, thereby obtaining a quantum dot composition in which the surface of the quantum dots was modified with cetylphosphonic acid and (4-bromobutyl)phosphonic acid. The obtained solution was cooled to room temperature, ethanol was added, and centrifugation was carried out to precipitate the quantum dot composition and remove the supernatant. Then, to the precipitate, toluene was added and dispersed, ethanol was added again and centrifugation was carried out, the supernatant was removed and dispersed again in toluene, thereby preparing a toluene dispersion of the quantum dot composition. The internal quantum efficiency of the obtained quantum dot composition was 76%. After irradiating the toluene dispersion of the quantum dot composition with blue light having a wavelength of 450 nm for 12 hours using a blue LED light source (manufactured by AS ONE Corporation., HL-36) under an atmospheric atmosphere, the fluorescence emission efficiency was measured, and as a result, the internal quantum efficiency was 74%.

[0136] (Example 4)

[0137] Under a nitrogen atmosphere, 10 g of the 1.0 wt% InP / ZnSe / ZnS octadecene dispersion obtained in Production Example 1 and 43 mg of 1H,1H,2H,2H-perfluorooctylphosphonic acid were added into a three-necked flask. Subsequently, while heating and stirring the flask under reduced pressure at 120 °C to dissolve them, degassing was carried out for 30 minutes. Nitrogen was purged into the flask, heated to 230 °C and stirred for 30 minutes, thereby obtaining a quantum dot composition in which the surface of the quantum dots was modified with 1H,1H,2H,2H-perfluorooctylphosphonic acid. The obtained solution was cooled to room temperature, ethanol was added, and centrifugation was carried out to precipitate the quantum dot composition and remove the supernatant. Then, to the precipitate, toluene was added and dispersed, ethanol was added again and centrifugation was carried out, the supernatant was removed and dispersed again in toluene, thereby preparing a toluene dispersion of the quantum dot composition. The internal quantum efficiency of the obtained quantum dot composition was 71%. After irradiating the toluene dispersion of the quantum dot composition with blue light having a wavelength of 450 nm for 12 hours using a blue LED light source (manufactured by AS ONE Corporation., HL-36) under an atmospheric atmosphere, the fluorescence emission efficiency was measured, and as a result, the internal quantum efficiency was 68%.

[0138] (Example 5)

[0139] Under a nitrogen atmosphere, 10 g of the 1.0 wt% AgInS2 / ZnS octadecene dispersion obtained in Production Example 2 and 31 mg of cetylphosphonic acid were added into a three-necked flask. Subsequently, while heating and stirring the flask under reduced pressure at 120 °C to dissolve it, degassing was carried out for 30 minutes. Nitrogen was purged into the flask, heated to 230 °C and stirred for 30 minutes, thereby obtaining a quantum dot composition in which the surface of the quantum dots was modified with cetylphosphonic acid. The obtained solution was cooled to room temperature, ethanol was added, and centrifugation was carried out, thereby precipitating the quantum dot composition and removing the supernatant. Then, to the precipitate, toluene was added and dispersed, ethanol was added again and centrifugation was carried out, the supernatant was removed and dispersed again in toluene, thereby preparing a toluene dispersion of the quantum dot composition. The internal quantum efficiency of the obtained quantum dot composition was 56%. After irradiating the toluene dispersion of the quantum dot composition with blue light having a wavelength of 450 nm for 12 hours using a blue LED light source (manufactured by AS ONE Corporation, HL-36) under an atmospheric atmosphere, the fluorescence emission efficiency was measured, and as a result, the internal quantum efficiency was 48%.

[0140] (Example 6)

[0141] Under a nitrogen atmosphere, 10 g of the 1.0 wt% AgInS2 / ZnS octadecene dispersion obtained in Production Example 2 and 43 mg of 1H,1H,2H,2H-perfluorooctylphosphonic acid were added into a three-necked flask. Subsequently, while heating and stirring the flask under reduced pressure at 120 °C to dissolve it, degassing was carried out for 30 minutes. Nitrogen was purged into the flask, heated to 230 °C and stirred for 30 minutes, thereby obtaining a quantum dot composition in which the surface of the quantum dots was modified with 1H,1H,2H,2H-perfluorooctylphosphonic acid. The obtained solution was cooled to room temperature, ethanol was added, and centrifugation was carried out, thereby precipitating the quantum dot composition and removing the supernatant. Then, to the precipitate, toluene was added and dispersed, ethanol was added again and centrifugation was carried out, the supernatant was removed and dispersed again in toluene, thereby preparing a toluene dispersion of the quantum dot composition. The internal quantum efficiency of the obtained quantum dot composition was 50%. After irradiating the toluene dispersion of the quantum dot composition with blue light having a wavelength of 450 nm for 12 hours using a blue LED light source (manufactured by AS ONE Corporation, HL-36) under an atmospheric atmosphere, the fluorescence emission efficiency was measured, and as a result, the internal quantum efficiency was 44%.

[0142] Regarding the toluene dispersion of the quantum dots of Production Example 1, the toluene dispersions of the quantum dot compositions of Examples 1 to 4, the toluene dispersion of the quantum dots of Production Example 2, and the toluene dispersions of the quantum dot compositions of Examples 5 and 6, by comparing the values of the internal quantum yield after blue light irradiation, it can be seen that the quantum dot compositions of Examples 1 to 4 and Examples 5 and 6 maintained higher values of the internal quantum yield. From this result, it was confirmed that by modifying the surface of the quantum dots with a phosphonic acid derivative, the reduction of the internal quantum yield due to light irradiation can be suppressed, and the photostability is improved.

[0143] (Production of Resin Composition and Wavelength Conversion Material)

[0144] (Example 7)

[0145] A wavelength conversion material was produced using the quantum dot composition obtained in Example 1. 2.5 g of a 20 wt% toluene solution of the above quantum dot composition was mixed and stirred with 5.0 g of an acrylic resin (manufactured by DIC CORPORATION: ACRYDIC BL-616-BA), and directly heated at 60 °C while removing the solvent under reduced pressure. Then, vacuum degassing was performed, and it was coated on a 50-μm-thick polyethylene terephthalate (PET) film, and a resin composition layer was formed using a bar coater. Then, the PET film was laminated on the resin composition layer. The film was heated at 60 °C for 2 hours and at 150 °C for 4 hours to cure the resin composition layer, and a wavelength conversion material was produced. The thickness of the obtained wavelength conversion material was 96 μm. In addition, the internal quantum efficiency of the obtained wavelength conversion material was 43%. In addition, the fluorescence emission efficiency of the obtained wavelength conversion material after being treated at 85 °C and 85% RH for 500 hours was measured, and as a result, the internal quantum efficiency was 41%.

[0146] (Example 8)

[0147] A wavelength conversion material was fabricated using the quantum dot composition obtained in Example 2. 2.5 g of a 20 wt% toluene solution of the above-mentioned quantum dot composition was mixed and stirred with 5.0 g of an acrylic resin (manufactured by DIC CORPORATION: ACRYDIC BL-616-BA), and directly heated at 60 °C while removing the solvent under reduced pressure. Then, vacuum degassing was performed, and it was coated on a 50-μm-thick polyethylene terephthalate (PET) film, and a resin composition layer was formed using a bar coater. Then, the PET film was laminated on the resin composition layer. The film was heated at 60 °C for 2 hours and at 150 °C for 4 hours to cure the resin composition layer, thereby fabricating a wavelength conversion material. The thickness of the obtained wavelength conversion material was 92 μm. In addition, the internal quantum efficiency of the obtained wavelength conversion material was 42%. Further, the fluorescence emission efficiency of the obtained wavelength conversion material after being treated at 85 °C and 85% RH for 500 hours was measured, and as a result, the internal quantum efficiency was 40%.

[0148] (Example 9)

[0149] A wavelength conversion material was fabricated using the quantum dot composition obtained in Example 3. 2.5 g of a 20 wt% toluene solution of the above-mentioned quantum dot composition was mixed and stirred with 5.0 g of an acrylic resin (manufactured by DIC CORPORATION: ACRYDIC BL-616-BA), and directly heated at 60 °C while removing the solvent under reduced pressure. Then, vacuum degassing was performed, and it was coated on a 50-μm-thick polyethylene terephthalate (PET) film, and a resin composition layer was formed using a bar coater. Then, the PET film was laminated on the resin composition layer. The film was heated at 60 °C for 2 hours and at 150 °C for 4 hours to cure the resin composition layer, thereby fabricating a wavelength conversion material. The thickness of the obtained wavelength conversion material was 95 μm. In addition, the internal quantum efficiency of the obtained wavelength conversion material was 45%. Further, the fluorescence emission efficiency of the obtained wavelength conversion material after being treated at 85 °C and 85% RH for 500 hours was measured, and as a result, the internal quantum efficiency was 43%.

[0150] (Example 10)

[0151] A wavelength conversion material was fabricated using the quantum dot composition obtained in Example 4. 2.5 g of a 20 wt% toluene solution of the above quantum dot composition was mixed and stirred with 5.0 g of a 40% xylene solution of a fluororesin, fluorinated ethylene-vinyl ether copolymer (LUMIFLON LF200 manufactured by AGC), and directly heated at 60 °C while removing the solvent under reduced pressure. Then, vacuum degassing was carried out and it was coated on a 50-μm thick polyethylene terephthalate (PET) film, and a resin composition layer was formed using a bar coater. Then, the PET film was laminated on the resin composition layer. The film was heated at 80 °C for 2 hours and at 100 °C for 2 hours to cure the resin composition layer, thereby fabricating the wavelength conversion material. The thickness of the obtained wavelength conversion material was 96 μm. In addition, the internal quantum efficiency of the obtained wavelength conversion material was 38%. Further, the fluorescence emission efficiency of the obtained wavelength conversion material after being treated at 85 °C and 85% RH for 500 hours was measured, and as a result, the internal quantum efficiency was 37%.

[0152] (Example 11)

[0153] A wavelength conversion material was fabricated using the quantum dot composition obtained in Example 5. 2.5 g of a 20 wt% toluene solution of the above quantum dot composition was mixed and stirred with 5.0 g of an acrylic resin (ACRYDIC BL-616-BA manufactured by DIC CORPORATION), and directly heated at 60 °C while removing the solvent under reduced pressure. Then, vacuum degassing was carried out and it was coated on a 50-μm thick polyethylene terephthalate (PET) film, and a resin composition layer was formed using a bar coater. Then, the PET film was laminated on the resin composition layer. The film was heated at 60 °C for 2 hours and at 150 °C for 4 hours to cure the resin composition layer, thereby fabricating the wavelength conversion material. The thickness of the obtained wavelength conversion material was 98 μm. In addition, the internal quantum efficiency of the obtained wavelength conversion material was 29%. Further, the fluorescence emission efficiency of the obtained wavelength conversion material after being treated at 85 °C and 85% RH for 500 hours was measured, and as a result, the internal quantum efficiency was 27%.

[0154] (Example 12)

[0155] A wavelength conversion material was fabricated using the quantum dot composition obtained in Example 6. 2.5 g of a 20 wt% toluene solution of the above quantum dot composition was mixed and stirred with 5.0 g of a 40% xylene solution of a fluorinated resin, vinylidene fluoride-vinyl ether copolymer (LUMIFLON LF200 manufactured by AGC), and directly heated at 60 °C while removing the solvent under reduced pressure. Then, vacuum degassing was performed, and it was coated on a 50-μm-thick polyethylene terephthalate (PET) film, and a resin composition layer was formed using a bar coater. Then, the PET film was laminated on the resin composition layer. The film was heated at 80 °C for 2 hours and at 100 °C for 2 hours to cure the resin composition layer, thereby fabricating the wavelength conversion material. The thickness of the obtained wavelength conversion material was 96 μm. In addition, the internal quantum efficiency of the obtained wavelength conversion material was 24%. Further, the fluorescence emission efficiency of the obtained wavelength conversion material after being treated at 85 °C and 85% RH for 500 hours was measured, and as a result, the internal quantum efficiency was 22%.

[0156] (Comparative Example 1)

[0157] A wavelength conversion material was fabricated using the quantum dots obtained in Production Example 1. 2.5 g of a 20 wt% toluene solution of the above quantum dots was mixed and stirred with 5.0 g of an acrylic resin (ACRYDIC BL-616-BA manufactured by DIC CORPORATION), and directly heated at 60 °C while removing the solvent under reduced pressure. Then, vacuum degassing was performed, and it was coated on a 50-μm-thick polyethylene terephthalate (PET) film, and a resin composition layer was formed using a bar coater. Then, the PET film was laminated on the resin composition layer. The film was heated at 60 °C for 2 hours and at 150 °C for 4 hours to cure the resin composition layer, thereby fabricating the wavelength conversion material. The thickness of the obtained wavelength conversion material was 96 μm. In addition, the internal quantum efficiency of the obtained wavelength conversion material was 37%. Further, the fluorescence emission efficiency of the obtained wavelength conversion material after being treated at 85 °C and 85% RH for 500 hours was measured, and as a result, the internal quantum efficiency was 19%.

[0158] (Comparative Example 2)

[0159] A wavelength conversion material was fabricated using the quantum dots obtained in Production Example 1. 2.5 g of a 20 wt% toluene solution of the above quantum dots was mixed and stirred with 5.0 g of a 40% xylene solution of a fluororesin, fluorovinyl-vinyl ether copolymer (LUMIFLON LF200 manufactured by AGC). The mixture was directly heated at 60 °C while removing the solvent under reduced pressure. Then, vacuum degassing was performed, and the resulting mixture was coated on a 50-μm thick polyethylene terephthalate (PET) film, and a resin composition layer was formed using a bar coater. Then, the PET film was laminated on the resin composition layer. The film was heated at 80 °C for 2 hours and then at 100 °C for 2 hours to cure the resin composition layer, thereby fabricating the wavelength conversion material. The thickness of the obtained wavelength conversion material was 98 μm. In addition, the internal quantum efficiency of the obtained wavelength conversion material was 26%. Further, the fluorescence emission efficiency of the obtained wavelength conversion material after being treated at 85 °C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 7%.

[0160] (Comparative Example 3)

[0161] A wavelength conversion material was fabricated using the quantum dots obtained in Production Example 2. 2.5 g of a 20 wt% toluene solution of the above quantum dots was mixed and stirred with 5.0 g of an acrylic resin (ACRYDIC BL-616-BA manufactured by DIC CORPORATION). The mixture was directly heated at 60 °C while removing the solvent under reduced pressure. Then, vacuum degassing was performed, and the resulting mixture was coated on a 50-μm thick polyethylene terephthalate (PET) film, and a resin composition layer was formed using a bar coater. Then, the PET film was laminated on the resin composition layer. The film was heated at 60 °C for 2 hours and then at 150 °C for 4 hours to cure the resin composition layer, thereby fabricating the wavelength conversion material. The thickness of the obtained wavelength conversion material was 98 μm. In addition, the internal quantum efficiency of the obtained wavelength conversion material was 26%. Further, the fluorescence emission efficiency of the obtained wavelength conversion material after being treated at 85 °C and 85% RH for 500 hours was measured, and the internal quantum efficiency was found to be 12%.

[0162] (Comparative Example 4)

[0163] A wavelength conversion material was fabricated using the quantum dots obtained in Production Example 2. A 20 wt% toluene solution of 2.5 g of the above-mentioned quantum dots was mixed and stirred with a 40% xylene solution of 5.0 g of a fluorine-containing resin, vinylidene fluoride-vinyl ether copolymer (LUMIFLON LF200 manufactured by AGC), and directly heated at 60 °C while removing the solvent under reduced pressure. Then, vacuum degassing was performed, and it was coated on a 50-μm thick polyethylene terephthalate (PET) film, and a resin composition layer was formed using a bar coater. Then, the PET film was laminated on the resin composition layer. The film was heated at 80 °C for 2 hours and then at 100 °C for 2 hours to cure the resin composition layer, thereby fabricating the wavelength conversion material. The thickness of the obtained wavelength conversion material was 97 μm. In addition, the internal quantum efficiency of the obtained wavelength conversion material was 14%. Further, the fluorescence emission efficiency of the obtained wavelength conversion material after being treated at 85 °C and 85% RH for 500 hours was measured, and as a result, the internal quantum efficiency was 4%.

[0164] For the wavelength conversion materials of Comparative Example 1 and Examples 7 to 9, Comparative Example 2 and Example 10, Comparative Example 3 and Example 11, and Comparative Example 4 and Example 12, the internal quantum efficiencies after being treated at 85 °C and 85% RH for 500 hours were compared. As a result, it was confirmed that the wavelength conversion materials using the quantum dot compositions of the present invention modified with phosphonic acid derivatives showed higher internal quantum efficiency values compared to the wavelength conversion materials using quantum dots not modified with phosphonic acid derivatives.

[0165] Based on the above, it was confirmed that the deterioration of the fluorescence emission efficiency due to light irradiation of the quantum dot compositions manufactured in the present invention was suppressed, and the stability was further improved. It was also confirmed that the resin compositions using the quantum dot compositions and the wavelength conversion materials obtained by curing them could suppress the deterioration of the fluorescence emission efficiency under high-temperature and high-humidity conditions and had high reliability.

[0166] This specification includes the following aspects.

[0167] [1]: A quantum dot composition, which is a quantum dot composition containing quantum dots that emit fluorescence upon excitation with light, characterized in that the quantum dots are composed of a semiconductor nanoparticle core containing no Cd or Pb and a semiconductor nanoparticle shell, and the surface of the quantum dots is modified with a phosphonic acid derivative.

[0168] [2]: The quantum dot composition according to the above [1], characterized in that the quantum dots are composed of the semiconductor nanoparticle core and one or more semiconductor nanoparticle shells that coat the semiconductor nanoparticle core.

[0169] [3]: The quantum dot composition according to [1] or [2] above, characterized in that the semiconductor nanoparticle core is one, more than one, or a 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.

[0170] [4]: The quantum dot composition according to any one of [1] to [3] above, characterized in that the semiconductor nanoparticle shell is one, more than one, or a mixed crystal selected from ZnS, ZnSe, ZnTe, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb.

[0171] [5]: The quantum dot composition according to any one of [1] to [4] above, characterized in that the phosphonic acid derivative is represented by the following formula (I).

[0172] [Chemical formula 9]

[0173]

[0174] (In formula (I), R1 is a monovalent organic group having one or more carbon atoms.)

[0175] [6]: The quantum dot composition according to [5] above, characterized in that the phosphonic acid derivative is selected from 3-phenyl-2-propenylphosphonic acid, tenofovir, 2-phosphonobutane-1,2,4-tricarboxylic 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, propylphosphonic 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-methoxyphenylphosphonic acid, hexadecylphosphonic acid, (4-hydroxybenzyl)phosphonic acid, phenylphosphonic acid, (1H,1H,2H,2H-heptadecafluorodecyl)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-mercapto decylphosphonic acid, and [11-(acryloyloxy)undecyl]phosphonic acid, etc.

[0176] [7]: The quantum dot composition according to any one of [1] to [4] above, characterized in that the phosphonic acid derivative is represented by the following formula (II).

[0177] [Chemical formula 10]

[0178]

[0179] (In formula (II), R2 is a divalent organic group having one or more carbon atoms.)

[0180] [8]: The quantum dot composition according to [7] above, characterized in that the phosphonic acid derivative is selected from m-xylene diphosphonic acid, o-xylene diphosphonic acid, methylene diphosphonic acid, 4-phosphonobenzoic acid, alendronic acid, 1,4-butane diphosphonic acid, glycine-N,N-bis(methylene phosphonic acid), p-xylene diphosphonic acid, zoledronic acid, 1,3-propylene diphosphonic acid, 1,5-pentylene diphosphonic acid, 1,4-phenylene diphosphonic acid, 1,2-ethylene diphosphonic acid, 1,6-hexylene diphosphonic acid, minodronic acid, and 1-hydroxyethane-1,1-diphosphonic acid, etc.

[0181] [9]: According to any one of the above [1] to [4] quantum dot compositions, it is characterized in that the phosphonic acid derivative is represented by the following formula (III).

[0182] [Chemical formula 11]

[0183]

[0184] (In formula (III), R3 is a trivalent organic group having one or more carbon atoms.)

[0185]

[10] : According to the quantum dot composition of the above [9], it is characterized in that the phosphonic acid derivative is nitrilotris(methylenephosphonic acid).

[0186]

[11] : According to any one of the above [1] to [4] quantum dot compositions, it is characterized in that the phosphonic acid derivative is represented by the following formula (IV).

[0187] [Chemical formula 12]

[0188]

[0189] (In formula (IV), R4 is a divalent organic group having one or more carbon atoms.)

[0190]

[12] : According to the quantum dot composition of the above

[11] , it is characterized in that the phosphonic acid derivative is N,N,N’,N’-ethylenediaminetetra(methylenephosphonic acid).

[0191]

[13] : According to the quantum dot composition of the above [5], it is characterized in that the R1 includes at least any one or more of a linear or branched alkyl group having one or more carbon atoms, a linear 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 phenol group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

[0192]

[14] : According to the quantum dot composition of the above [7], it is characterized in that the R2 includes at least any one or more of a linear or branched alkyl group having one or more carbon atoms, a linear 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 phenol group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

[0193]

[15] : The quantum dot composition according to [9] above, characterized in that the R3 contains at least any one or more of a linear or branched alkyl group having one or more carbon atoms, a linear 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 phenol group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

[0194]

[16] : The quantum dot composition according to

[11] above, characterized in that the R4 contains at least any one or more of a linear or branched alkyl group having one or more carbon atoms, a linear 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 phenol group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

[0195]

[17] : A resin composition, characterized in that it is a resin composition obtained by dispersing any one of the quantum dot compositions in [1] to

[16] above in a resin.

[0196]

[18] : The resin composition according to

[17] above, characterized in that the resin is at least one or more selected from epoxy resins, acrylic resins, fluororesins, silicone resins, carbonate resins, and glass.

[0197]

[19] : A wavelength conversion material, characterized in that it uses a cured product of the resin composition in

[17] or

[18] above.

[0198] In addition, the present invention is not limited to the above embodiments. The above embodiments are examples, and all solutions having a composition substantially the same as the technical concept described in the claims of the present invention and exhibiting the same technical effects are included within the technical scope of the present invention.

Claims

1. A quantum dot composition, which is a quantum dot composition containing quantum dots that emit fluorescence upon excitation by light, and is characterized in that, The quantum dots are composed of a semiconductor nanoparticle core that does not contain Cd or Pb and a semiconductor nanoparticle shell, and the surfaces of the quantum dots are modified with phosphonic acid derivatives.

2. The quantum dot composition according to claim 1, wherein The quantum dots are composed of the semiconductor nanoparticle core and one or more semiconductor nanoparticle shells that coat the semiconductor nanoparticle core.

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

5. The quantum dot composition according to claim 1, wherein The phosphonic acid derivative is represented by the following formula (I): [Chemical formula 1] In formula (I), R1 is a monovalent organic group having one or more carbon atoms.

6. The quantum dot composition according to claim 5, wherein The phosphonic acid derivative is one or more selected from 3-phenyl-2-propenylphosphonic acid, tenofovir, 2-phosphonobutane-1,2,4-tricarboxylic 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, propylphosphonic 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-methoxyphenylphosphonic acid, hexadecylphosphonic acid, (4-hydroxybenzyl)phosphonic acid, phenylphosphonic acid, (1H,1H,2H,2H-heptadecafluorodecyl)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-mercapto-decylphosphonic acid, and [11-(acryloyloxy)undecyl]phosphonic acid.

7. The quantum dot composition according to claim 1, wherein The phosphonic acid derivative is represented by the following formula (II): [Chemical formula 2] In formula (II), R2 is a divalent organic group having one or more carbon atoms.

8. The quantum dot composition according to claim 7, wherein, The phosphonic acid derivative is one or more selected from m-xylene diphosphonic acid, o-xylene diphosphonic acid, methylene diphosphonic acid, 4-phosphonobenzoic acid, alendronic acid, 1,4-butane diphosphonic acid, glycine-N,N-bis(methylenephosphonic acid), p-xylene diphosphonic acid, zoledronic acid, 1,3-propylene diphosphonic acid, 1,5-pentylene diphosphonic acid, 1,4-phenylene diphosphonic acid, 1,2-ethylene diphosphonic acid, 1,6-hexylene diphosphonic acid, minodronic acid, and 1-hydroxyethane-1,1-diphosphonic acid.

9. The quantum dot composition according to claim 1, wherein The phosphonic acid derivative is represented by the following formula (III): [Chemical formula 3] In formula (III), R3 is a trivalent organic group having one or more carbon atoms.

10. The quantum dot composition according to claim 9, wherein The phosphonic acid derivative is nitrilotri(methylenephosphonic acid).

11. The quantum dot composition according to claim 1, wherein The phosphonic acid derivative is represented by the following formula (IV): [Chemical formula 4] In formula (IV), R4 is a divalent 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 N,N,N’,N’-ethylenediaminetetra(methylenephosphonic acid).

13. The quantum dot composition according to claim 5, characterized in that, The R1 includes at least any one or more of a linear or branched alkyl group having one or more carbon atoms, a linear 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 phenol group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

14. The quantum dot composition according to claim 7, characterized in that, The R2 includes at least any one or more of a linear or branched alkyl group having one or more carbon atoms, a linear 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 phenol group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

15. The quantum dot composition according to claim 9, characterized in that, The R3 includes at least any one or more of a linear or branched alkyl group having one or more carbon atoms, a linear 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 phenol 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 11, characterized in that, The R4 includes at least any one or more of a linear or branched alkyl group having one or more carbon atoms, a linear 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 phenol group, a perfluoroalkyl group, a hydroxyl group, a phenyl group, a thiol group, an acryloyl group, and an oligoethylene glycol group.

17. A resin composition, characterized in that, It is a resin composition obtained by dispersing the quantum dot composition according to any one of claims 1 to 16 in a resin.

18. The resin composition according to claim 17, wherein The resin is at least one or more selected from epoxy resins, acrylic resins, fluororesins, silicone resins, carbonate resins, and glass.

19. A wavelength conversion material, characterized in that, It uses a cured product of the resin composition according to claim 17.

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