Quantum dot complex, method for producing same, quantum dot complex dispersion, molded body, method for producing same, light-emitting device, power generation device, and display body

Abstract

The present invention addresses the problem of providing a quantum dot complex having excellent light stability and comprising quantum dots having a perovskite crystal structure. In order to solve said problem, provided is a quantum dot complex comprising: quantum dots having a perovskite crystal structure; a first ligand serving as a specific zwitterionic bidentate ligand; and a second ligand serving as another zwitterionic bidentate ligand. Also provided are a quantum dot complex dispersion containing the quantum dot complex and an organic solvent, and a quantum dot molded body containing the quantum dot complex and a polymer. Further provided are a light-emitting device, a power generation device, and a display body that each include the quantum dot molded body.

Description

Quantum dot composite and method for manufacturing the same, quantum dot composite dispersion, molded body and method for manufacturing the same, light-emitting device, power-generating device, and display body

[0001] The present invention relates to quantum dot composites and methods for producing the same, as well as quantum dot composite dispersions, molded articles and methods for producing the same, light-emitting devices, power-generating devices, and display elements using the quantum dot composite.

[0002] Quantum dots are nanoscale semiconductor materials that can exhibit quantum effects by confining electrons within them. Such quantum dots are being considered for use in, for example, light-emitting devices, power-generating devices, and displays (Patent Documents 1-4).

[0003] Quantum dots with a perovskite crystal structure, a type of quantum dot, are expected to be used as materials for the aforementioned devices due to their high photoluminescence quantum yield (PLQY). Hereafter, photoluminescence quantum yield (PLQY) may be referred to as "PLQY".

[0004] Japanese Patent Publication No. 2024-031023, International Publication No. 2023 / 163023, Japanese Patent Publication No. 2018-170477, International Publication No. 2018 / 028870 (Corresponding publication: U.S. Patent Application Publication No. 2019 / 153313)

[0005] Quantum dots generally tend to experience a decrease in their luminescence quantum yield (PLQY) over time when illuminated with light. Therefore, for example, when a quantum dot is irradiated with excitation light to cause it to emit light, the excitation light may reduce the PLQY of the quantum dot. Also, for example, when illuminated with ultraviolet and visible light contained in ambient light, the PLQY of the quantum dot may decrease due to these light rays. From the perspective of practical application of devices using quantum dots, it is necessary to suppress this decrease in PLQY and improve photostability.

[0006] The present invention was devised in view of the above problems, and an object of the present invention is to provide: a quantum dot composite containing quantum dots having a perovskite-type crystal structure and having excellent light stability, and a method for producing the same; a quantum dot composite dispersion containing the quantum dot composite; a molded article containing the quantum dot composite and a method for producing the same; and a light-emitting device, a power generating device and a display including the molded article.

[0007] The present inventor conducted intensive studies to solve the above problems. As a result, the present inventor found that a quantum dot composite containing a combination of quantum dots having a perovskite-type crystal structure, a first ligand as a specific zwitterionic bidentate ligand, and a second ligand as another zwitterionic bidentate ligand can solve the above problems, and completed the present invention. That is, the present invention includes the following.

[0008] <1> A quantum dot composite comprising quantum dots having a perovskite-type crystal structure, a first ligand represented by the following formula (1-1), and a second ligand represented by the following formula (2-1). (In formula (1-1), R ａ１ , R ａ２ and R ａ３ each independently represent a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms, R ａ４ represents a divalent aliphatic hydrocarbon group that may have a substituent, and X ａ represents a divalent group.) (In formula (2-1), R ｂ１ represents a monovalent aliphatic hydrocarbon group having 7 or more carbon atoms that may have a substituent, R ｂ２ and R ｂ３ each independently represent a hydrogen atom or a monovalent aliphatic hydrocarbon group that may have a substituent, R ｂ４ represents a divalent aliphatic hydrocarbon group that may have a substituent, X ｂ represents a divalent group.) <2> In formula (1-1), a positively charged nitrogen atom N ＋ and a negatively charged oxygen atom O －The quantum dot composite described in <1>, wherein the number of skeletal atoms connecting and is 3 or more and 6 or less. <3> In equation (1-1), R ａ４ The number of carbon atoms in the divalent aliphatic hydrocarbon group is R ａ１ , R ａ２ and R ａ３ A quantum dot composite as described in <1> or <2>, having a number of carbon atoms greater than the number of carbon atoms in each of the following equations: <4> In equation (2-1), a nitrogen atom N having a positive charge. ＋ And, an oxygen atom O that has a negative charge － A quantum dot composite according to any one of <1> to <3>, wherein the number of skeletal atoms connecting and is 1 or more and 6 or less. <5> In equation (2-1), R ｂ４ The number of carbon atoms in the divalent aliphatic hydrocarbon group is R ｂ１A quantum dot composite according to any one of <1> to <4>, wherein the number of carbon atoms of the monovalent aliphatic hydrocarbon group is smaller than the number of carbon atoms of the monovalent aliphatic hydrocarbon group. <6> A quantum dot composite according to any one of <1> to <5>, wherein the total amount of the first ligand and the second ligand is 0.01 times or more and 5.0 times or less on a molar basis relative to the amount of the quantum dot. <7> A quantum dot composite according to any one of <1> to <6>, wherein the amount of the first ligand is 0.2 times or more and 20.0 times or less on a molar basis relative to the amount of the second ligand. <8> A quantum dot composite according to any one of <1> to <7>, wherein the average particle size of the quantum dot composite is 1 nm or more and 30 nm or less. <9> A quantum dot composite dispersion comprising the quantum dot composite according to any one of <1> to <8> and an organic solvent. <10> A molded article comprising the quantum dot composite according to any one of <1> to <8> and a polymer. <11> The molded article according to <10>, comprising 99% by weight or more of the polymer. <12> The molded article according to <10> or <11>, wherein the polymer comprises a cyclic olefin polymer. <13> The molded article according to <12>, wherein the cyclic olefin polymer comprises a norbornene polymer, and the norbornene polymer comprises at least one selected from the group consisting of a hydride of a ring-opening polymer of a monomer having a norbornene structure, an addition copolymer of a monomer having a norbornene structure and an α-olefin, and its hydride. <14> The molded article according to <12> or <13>, wherein the cyclic olefin polymer comprises a hydrogenated block copolymer [E]; and the hydrogenated block copolymer [E] is a hydrogenated block copolymer obtained by hydrogenating a block copolymer [D] comprising a polymer block [A] mainly composed of repeating units [I] derived from an aromatic vinyl compound, a polymer block [B] mainly composed of repeating units [I] derived from an aromatic vinyl compound and repeating units [II] derived from a chain-like conjugated diene compound, or a polymer block [C] mainly composed of repeating units [II] derived from a chain-like conjugated diene compound. <15> The molded article according to <14>, wherein the cyclic olefin polymer contains an alkoxysilyl group.<16> The molded body according to any one of <10> to <15>, wherein the amount of quantum dots per 100 parts by weight of the molded body is 0.05 parts by weight or more and 50 parts by weight or less. <17> The molded body according to any one of <10> to <16>, wherein the molded body is a film. <18> A light-emitting device comprising a light-converting element, wherein the light-converting element includes the molded body according to any one of <10> to <17>. <19> A power-generating device comprising a power-generating element, wherein the power-generating element includes the molded body according to any one of <10> to <17>. <20> A display body comprising a light-converting element, wherein the light-converting element includes the molded body according to any one of <10> to <17>. <21> A method for producing a quantum dot composite according to any one of <1> to <8>, comprising the steps of: producing a quantum dot having a perovskite crystal structure; and mixing the quantum dot, the first ligand and the second ligand. <22> A method for producing a molded article according to any one of <10> to <17>, comprising the steps of: molding a liquid composition containing a quantum dot composite, a polymer and a solvent; and drying the molded liquid composition. <23> The method for producing a molded article according to <22>, wherein the step of molding the liquid composition comprises coating the liquid composition, and the method of coating the liquid composition is selected from the group consisting of a die coater, a gravure coater, a comma coater, a knife coater and an inkjet method.

[0009] According to the present invention, it is possible to provide a quantum dot composite having excellent photostability and containing quantum dots having a perovskite crystal structure, and a method for producing the same; a quantum dot composite dispersion containing the quantum dot composite; a molded article containing the quantum dot composite and a method for producing the same; and a light-emitting device, a power-generating device, and a display body containing the molded article.

[0010] Figure 1 is a graph showing the results of Examples 1 and 5 and Comparative Examples 1, 2 and 5 of the present invention.

[0011] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and can be modified and implemented as appropriate without departing from the scope of the claims and their equivalents. The components of the embodiments shown below can be combined as appropriate.

[0012] In the following description, the expression "may have substituents" for a compound or group includes both cases where some or all of the hydrogen atoms of the compound or group are substituted with substituents, and cases where the hydrogen atoms of the compound or group are not substituted with substituents.

[0013] In the following explanation, the term "(meth)acrylic" includes "acrylic," "methacrylic," and combinations thereof unless otherwise specified. Similarly, the term "(meth)acrylonitrile" includes "acrylonitrile," "methacrylonitrile," and combinations thereof unless otherwise specified.

[0014] In the following explanation, the term "solvent" may, for the sake of clarity, encompass not only the medium in a solution but also the dispersion medium used to disperse solid matter within it.

[0015] In the following description, unless otherwise specified, "plate," "layer," and "film" may refer to rigid members, or they may refer to flexible members such as resin films.

[0016] <Quantum Dot Composite> (Overview of Quantum Dot Composite) A quantum dot composite according to one embodiment of the present invention includes a quantum dot having a perovskite crystal structure, a first ligand represented by the following formula (1-1), and a second ligand represented by the following formula (2-1). The first and second ligands usually function as a zwitterbidentate ligand and coordinate to the quantum dot.

[0017]

[0018] (In equation (1-1), R ａ１ , R ａ２ and R ａ３ Each of these independently represents a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms, Rａ４ represents a divalent aliphatic hydrocarbon group which may have substituents, and X ａ (This represents a divalent group.)

[0019]

[0020] (In equation (2-1), R ｂ１ R represents a monovalent aliphatic hydrocarbon group having 7 or more carbon atoms, which may have substituents. ｂ２ and R ｂ３ R represents a hydrogen atom or a monovalent aliphatic hydrocarbon group which may have substituents. ｂ４ represents a divalent aliphatic hydrocarbon group which may have substituents, and X ｂ (This represents a divalent group.)

[0021] This quantum dot composite exhibits excellent photostability. Specifically, when illuminated with light, the quantum dot composite can suppress the decrease in luminescence quantum yield (PLQY) over time. Therefore, such a quantum dot composite can maintain the high luminescence quantum yield (PLQY) of quantum dots having a perovskite crystal structure over a long period of time.

[0022] Regarding the technical significance of obtaining the excellent effects described above, the inventors of the present invention surmise the following. However, the surmise described below does not limit the scope of the present invention.

[0023] Quantum dots with a perovskite crystal structure generally exhibit luminescence with a wide color gamut and high color purity. Because of these excellent luminescence properties, quantum dots are attracting attention as next-generation luminescent materials. For example, these quantum dots are expected to have applications in display devices. However, conventionally, quantum dots have been prone to degradation due to irradiation with blue light from display devices, resulting in the loss of their excellent luminescence properties.

[0024] Generally, quantum dots can aggregate or disintegrate due to heat or solvents, leading to a decrease in the quantum emission yield (PLQY). Therefore, conventional methods have involved coordinating ligands to the surface of quantum dots to improve this. However, these ligands can detach from the quantum dot surface due to light energy, causing aggregation of quantum dots or the disintegration of the quantum dots themselves. This aggregation and disintegration is considered one of the reasons why the PLQY of conventional quantum dot-containing materials decreased under the influence of light.

[0025] In contrast, the first and second ligands used in the quantum dot composite described above are zwitterbidentate ligands. Therefore, the first and second ligands have the characteristics of possessing both positive and negative charges, having charges at two different positions, and having multiple binding sites. A zwitterbidentate ligand with such characteristics can accommodate all binding modes necessary to fill surface defects in quantum dots with just its molecule. Furthermore, since the zwitterbidentate ligand does not participate in acid-base equilibrium, its adsorption and desorption are suppressed. Moreover, in the first and second ligands, the positively charged binding site and the negatively charged binding site are separated via a hydrocarbon group, thus improving the binding strength due to the chelation effect. Therefore, since the desorption of the first and second ligands from the quantum dot when exposed to light is suppressed, the decrease in the luminescence quantum yield (PLQY) can be suppressed.

[0026] Furthermore, the first ligand has a positive charge (N) near the end of the main chain of the molecule. ＋ ) has a positive charge, and relatively, the positively charged binding site is more likely to coordinate to the quantum dot. On the other hand, the second ligand has a positive charge far from the end of the main chain of the molecule, and relatively, a negative charge (O － ) Binding sites with this characteristic readily coordinate to quantum dots. Furthermore, by introducing a combination of bipolar bidentate ligands with different charge signs (i.e., positive and negative) at these readily binding sites, the coordination mode of the bipolar bidentate ligands becomes stable and robust, effectively suppressing their detachment, thus achieving remarkable photostability.

[0027] (Quantum dots) Quantum dots have a perovskite crystal structure. A "perovskite crystal structure" is a type of crystal structure, and perovskite (CaTiO) ３ This refers to the same crystal structure as ). In a perovskite crystal structure, for example, if we designate the sites of the crystal structure as "A", "B", and "X", ideally it has a cubic unit cell, with A located at each vertex of the cubic crystal, B located at the body center, and X located at the face center of the cubic crystal with B at the center.

[0028] Quantum dots having a perovskite crystal structure preferably have a composition represented by the following formula (A). Among the materials represented by the following formula (A), those in which X represents a halogen ion are sometimes called metal halide perovskites.

[0029] A （ｓ＋ａ） B （ｔ＋ｂ） X （ｕ＋ｃ） (A) (In formula (A) above, A represents a monovalent cation; B represents a divalent metal ion; X represents a monovalent anion; a represents a number such that -0.2 ≤ a ≤ 0.2; b represents a number such that -0.2 ≤ b ≤ 0.2; c represents a number such that -0.5 ≤ c ≤ 0.5; s represents an integer between 1 and 4 (inclusive); t represents 1 or 2; u represents an integer between 3 and 9 (inclusive), satisfying s + (2 × t) = u.)

[0030] In formula (A) above, s represents an integer between 1 and 4, t represents 1 or 2, and u represents an integer between 3 and 9. Also, s, t, and u satisfy "s + (2 × t) = u". Preferably, s, t, and u are such that "s:t:u" is represented by any of the positive integers "1:1:3", "4:1:6", and "2:1:4". Particularly preferably, "s:t:u" is represented by "1:1:3".

[0031] In formula (A) above, a represents a number that satisfies -0.2 ≤ a ≤ 0.2. Preferably, a represents a number that satisfies -0.1 ≤ a ≤ 0.1, and particularly preferably a = 0.

[0032] In equation (A), b represents a number that satisfies -0.2 ≤ b ≤ 0.2. Preferably, b represents a number that satisfies -0.1 ≤ b ≤ 0.1, and particularly preferably b = 0.

[0033] In equation (A), c represents a number that satisfies -0.5 ≤ c ≤ 0.5. Preferably, c represents a number that satisfies -0.3 ≤ c ≤ 0.3, and particularly preferably c = 0.

[0034] In equation (A), the preferred combination of a, b, c, s, t, and u is a=b=c=0, s=1, t=1, and u=3. Therefore, the quantum dot is "ABX ３ It is preferable to have a composition represented by ".

[0035] The A-site material constituting the A-site of the perovskite crystal structure of quantum dots is typically a monovalent cation. In formula (A), A represents this monovalent cation as the A-site material. Examples of monovalent cations include ions of Group 1 of the long-period periodic table (alkali metal ions) and monovalent organic cations. Examples of alkali metals corresponding to alkali metal ions include cesium (Cs), rubidium (Rb), potassium (K), sodium (Na), and lithium (Li). Examples of monovalent organic cations include methylammonium (MA), ethylammonium (EA), formamidinium (FA), and guanidium (GA). The A-site material may be used alone or in combination of two or more types.

[0036] From the viewpoint of the tolerance factor (TF) for perovskite crystal structures, it is preferable that a specific range of sites within the A site of the perovskite crystal structure consists of at least one selected from the group consisting of cesium (Cs), methylammonium (MA), ethylammonium (EA), formamidinium (FA), and guanidium (GA). Therefore, it is preferable that A in formula (A) contains at least one selected from the group consisting of cesium (Cs), methylammonium (MA), ethylammonium (EA), formamidinium (FA), and guanidium (GA) in a specific range of amount. The aforementioned specific range is preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and usually 100 mol% or less. Furthermore, among the above group, organic cations such as methylammonium (MA), ethylammonium (EA), formamidinium (FA), and guanidium (GA) are preferred, methylammonium (MA) and formamidinium (FA) are more preferred, and formamidinium (FA) is even more preferred.

[0037] The B-site material constituting the B-site of the perovskite crystal structure of quantum dots is usually a divalent metal ion. In formula (A), B represents this divalent metal ion as the B-site material. Examples of metals corresponding to the divalent metal ion include Group 14 metals such as lead (Pb), germanium (Ge), tin (Sn), and silicon (Si), with lead (Pb), germanium (Ge), tin (Sn), and silicon (Si) being preferred. The B-site material may be used alone or in combination of two or more types. Furthermore, the B-site material may also contain any metal such as antimony (Sb), bismuth (Bi), copper (Cu), nickel (Ni), cobalt (Co), iron (Fe), manganese (Mn), chromium (Cr), cadmium (Cd), europium (Eu), ytterbium (Yb), and silver (Ag), within an elemental ratio of 5% or less of the Group 14 metals.

[0038] The X-site material constituting the X-site of the perovskite crystal structure of quantum dots is usually a monovalent anion. In formula (A), X represents this monovalent anion as the X-site material. The monovalent anion is preferably a halogen ion. Examples of halogens corresponding to halogen ions include chlorine (Cl), bromine (Br), and iodine (I). The X-site material may be used alone or in combination of two or more types. Furthermore, the X-site material may contain monovalent pseudohalide ions such as cyanides, isothiocyanates, oxocyanates, thiocyanates, selenocyanates, sulfides, fulminate ions, azide ions, borohydride ions, and hexafluorophosphate ions, within a range of 20% or less of the elemental ratio of the X-site.

[0039] The composition of the quantum dot is preferably selected appropriately considering the energy band gap of the quantum dot and the sizes of the A-site material, B-site material, and X-site material. An example of a preferred quantum dot composition is Cs ａ１ MA ａ２ EA ａ３ FA ａ４ GA ａ５ Na ａ６ K ａ７ Rb(p-a1-a2-a3-a4-a5-a6-a7)Pb ｂ１ Sn ｂ２ Ge （ｑ－ｂ１－ｂ２） (Cl （１－ｙ－ｚ） Br ｙ I ｚ ) ｒ Examples include (0≦a1≦p, 0≦a2≦p, 0≦a3≦p, 0≦a4≦p, 0≦a5≦p, 0≦a6≦p, 0≦a7≦p, a1+a2+a3+a4+a5+a6+a7≦p, 0≦b1≦q, 0≦b2≦q, b1+b2≦q, 0≦y≦1, 0≦z≦1, y+z≦1, 1≦p≦4, 1≦q≦2, 3≦r≦9). However, this is not limited to these specific examples.

[0040] ABX is a perovskite-type structure. ３ From the viewpoint of stabilizing the crystal structure, it is preferable that the tolerance factor TF is in the range of 0.70 to 1.10. An example of a quantum dot composition having a tolerance factor TF in the above range is CsPbBr３ (TF=0.86), FAPbBr ３ (TF=1.01), CsPbI ３ (TF = 0.85), and CsSnI ３ (TF = 0.92) is one example.

[0041] Quantum dots may be used individually, each having the same composition, or in combination of two or more types having different compositions.

[0042] Quantum dots are typically included in quantum dot composites in the form of particles. Quantum dots are generally nanometer-sized, and their average particle size is preferably within a range that allows them to function as a light-emitting material. The average particle size range of quantum dots is preferably 1 nm or more, more preferably 2 nm or more, even more preferably 4 nm or more, preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 16 nm or less.

[0043] The average particle size of quantum dots is determined by the maximum wavelength (λ) of photoluminescence (PL) measured by a fluorescence spectrophotometer. ＰＬ This can be determined from the following. Quantum dots, which are light-emitting materials, generally have an energy band gap that changes with particle size, and a maximum wavelength λ ＰＬ For example, quantum dots such as CsPbBr ３ So, the average particle size is 2.6 nm and λ ＰＬ The wavelength is 450 nm, and the average particle size is 6.2 nm. ＰＬ λ is 500 nm, with an average particle size of 15 nm. ＰＬ Its wavelength is 523 nm.

[0044] Quantum dots function as phosphors that can emit fluorescence upon receiving excitation light. Therefore, quantum dots can typically emit light in the visible to near-infrared wavelength range (300 nm to 1000 nm). For this reason, quantum dots can be used as luminescent particles. The emission may be caused by photoexcitation or by electrical excitation. When emission is caused by photoexcitation, the wavelength range of the excitation light is preferably 200 nm or more, more preferably 250 nm or more, even more preferably 300 nm or more, preferably 800 nm or less, more preferably 750 nm or less, and even more preferably 600 nm or less.

[0045] The amount of quantum dots is preferably 1% by weight or more, more preferably 10% by weight or more, even more preferably 50% by weight or more, preferably 95% by weight or less, more preferably 90% by weight or less, and even more preferably 80% by weight or less, based on 100% by weight of the quantum dot composite. When the amount of quantum dots is within the above range, the photostability can be effectively improved.

[0046] (First ligand) The first ligand is represented by the following formula (1-1).

[0047]

[0048] In equation (1-1), R ａ１ , R ａ２ and R ａ３ Each of these independently represents a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms. ａ１ , R ａ２ and R ａ３ The range of carbon atoms in the monovalent aliphatic hydrocarbon group is preferably 1 to 4, more preferably 1 to 3, even more preferably 1 to 2, and particularly preferably 1. The monovalent aliphatic hydrocarbon group may be linear or cyclic. Furthermore, the monovalent aliphatic hydrocarbon group may be an aliphatic saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group. Examples of monovalent aliphatic hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl groups. Among these, R ａ１ , R ａ２ and R ａ３Hydrogen atoms and alkyl groups are preferred, methyl groups and ethyl groups are preferred, and methyl groups are more preferred. ａ１ , R ａ２ and R ａ３ They may be the same or they may be different.

[0049] In equation (1-1), R ａ４ R represents a divalent aliphatic hydrocarbon group which may have substituents. ａ４ The range of carbon atoms in the divalent aliphatic hydrocarbon group in is usually 1 or more, preferably 2 or more, preferably 10 or less, more preferably 6 or less, and even more preferably 4 or less. ａ４ The number of carbon atoms in the divalent aliphatic hydrocarbon group in R is ａ１ , R ａ２ and R ａ３ It is preferable that it is greater than the number of carbon atoms in each. Here, R ａ４ In the calculation of the number of carbon atoms in a divalent aliphatic hydrocarbon group, the number of carbon atoms in the substituents is not included.

[0050] R ａ４ The divalent aliphatic hydrocarbon group in this compound may be linear or cyclic. Furthermore, the divalent aliphatic hydrocarbon group may be an aliphatic saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group. ａ４ Examples of divalent aliphatic hydrocarbon groups in this context include alkylene groups such as methylene, ethylene, propylene, butylene, pentylene, and hexylene.

[0051] R ａ４ Examples of substituents that the divalent aliphatic hydrocarbon group may have include alkoxy groups such as methoxy, ethoxy, and butoxy groups; aryloxy groups; alkylthio groups; oxo groups (=O); and the like. The substituent may be one type or two or more types.

[0052] Among those mentioned above, R ａ４ The group is preferably a divalent aliphatic hydrocarbon group without substituents, more preferably an alkylene group, even more preferably a methylene group, an ethylene group, a propylene group, or a butylene group, and particularly preferably an ethylene group.

[0053] In formula (1-1), X ａ represents a divalent group. X ａ preferably has a large number of atoms from the viewpoint of effectively improving light stability. For example, X ａ the total number of skeleton atoms other than hydrogen atoms contained in is preferably 4 or more, more preferably 7 or more, still more preferably 10 or more, still more preferably 20 or more, still more preferably 30 or more, and preferably 70 or less, more preferably 60 or less, still more preferably 50 or less.

[0054] X ａ has an atom bonded to the oxygen atom at the terminal of formula (1-1) (the negatively charged oxygen atom O － ). Since this atom is the first atom counted from the terminal oxygen atom, it is sometimes referred to as the "first atom" as appropriate. In X ａ , the first atom is preferably bonded to another oxygen atom shown in formula (1-1). That is, X ａ preferably includes the first atom bonded to both of the two oxygen atoms shown in formula (1-1). The first atom of X ａ is preferably selected from Group 15 and Group 16 of the long-form periodic table, more preferably a sulfur atom or a phosphorus atom, and even more preferably a phosphorus atom.

[0055] X ａIt is preferable that the group contains a group bonded to the first atom. This group may be referred to as a "side chain group" below. The number of side chain groups may be one or two or more. It is preferable that the side chain group contains an oxygen atom bonded to the first atom. Examples of side chain groups include optionally substituted hydrocarbon oxy groups such as optionally substituted alkoxy groups, optionally substituted alkenyloxy groups, optionally substituted alkapolienyloxy groups, optionally substituted aryloxy groups, etc.; oxo groups, etc. Optional substituents on hydrocarbon oxy groups include, for example, hydrocarbon oxy groups such as alkoxy groups, alkenyloxy groups, alkapolienyloxy groups, aryloxy groups, etc.; hydrocarbon carbonyloxy groups such as alkylcarbonyloxy groups, alkenylcarbonyloxy groups, alkapolienylcarbonyloxy groups, arylcarbonyloxy groups, etc.; oxo groups, etc. "Alcapolienyloxy group" refers to a group in which an alkapolienyl group is bonded to an oxy group. Furthermore, "alkapolyenyl group" represents an aliphatic unsaturated hydrocarbon group having two or more double bonds. Furthermore, "hydrocarbon oxy group" represents a group in which a hydrocarbon group is bonded to an oxy group. Furthermore, "hydrocarbon carbonyl oxy group" represents a group in which a hydrocarbon group is bonded to the carbonyl group of a carbonyl oxy group. Among these, the side chain group is preferably an alkoxy group and an oxo group which may have substituents, more preferably an alkoxy group and an oxo group which may have a hydrocarbon carbonyl oxy group, and even more preferably an alkoxy group and an oxo group which have a hydrocarbon carbonyl oxy group.

[0056] From the viewpoint of effectively improving photostability, the range of carbon atoms in the side chain group is preferably 7 or more, more preferably 10 or more, even more preferably 20 or more, even more preferably 30 or more, preferably 70 or less, more preferably 60 or less, even more preferably 50 or less, and even more preferably 40 or less.

[0057] X ａ From the viewpoint of effectively improving photostability, it is preferable that it be represented by the following formula (1-2).

[0058]

[0059] In formula (1-2), R ａ５ represents a monovalent hydrocarbon group which may have a substituent. In addition, * represents a binding site.)

[0060] In formula (1-2), R ａ５ represents a monovalent hydrocarbon group which may have a substituent. The monovalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Further, the aliphatic hydrocarbon group may be chain-like or cyclic. The aliphatic hydrocarbon group may be an aliphatic saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group. R ａ５ The number of carbon atoms of the monovalent hydrocarbon group for R ａ５ is generally 1 or more, preferably 2 or more, and preferably 60 or less, more preferably 50 or less, still more preferably 40 or less. The upper limit of the number of carbon atoms of the monovalent hydrocarbon group for R ａ５ may be 12 or less, 8 or less, 6 or less, or 4 or less. Here, the number of carbon atoms of the monovalent hydrocarbon group for R ａ５ does not include the number of carbon atoms of the substituent. Examples of the monovalent hydrocarbon group for R

[0061] include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, and hexyl group; aryl groups such as phenyl group and naphthyl group. Among these, an alkyl group is preferred, and a propyl group is more preferred. R ａ５Examples of substituents that the monovalent hydrocarbon group in the above may have include hydrocarbon oxy groups, hydrocarbon carbonyl oxy groups, and oxo groups. Among these, hydrocarbon carbonyl oxy groups are preferred. The hydrocarbon group contained in the hydrocarbon carbonyl oxy group is preferably an aliphatic hydrocarbon group, and more preferably a chain aliphatic hydrocarbon group. Furthermore, this aliphatic hydrocarbon group may be saturated or unsaturated. Among hydrocarbon carbonyl oxy groups, alkyl carbonyl oxy groups, alkenyl carbonyl oxy groups, and alkapolienyl carbonyl oxy groups are preferred, and alkyl carbonyl oxy groups and alkapolienyl carbonyl oxy groups are more preferred. The range of the number of carbon atoms in this substituent is preferably 1 or more, more preferably 2 or more, even more preferably 7 or more, even more preferably 10 or more, preferably 40 or less, more preferably 30 or less, and even more preferably 20 or less. Also, R ａ５ The number of substituents on the monovalent hydrocarbon group in this compound may be one or two or more.

[0062] R including substituents ａ５ The total number of carbon atoms is preferably 7 or more, more preferably 10 or more, even more preferably 20 or more, even more preferably 30 or more, preferably 60 or less, more preferably 50 or less, and even more preferably 40 or less.

[0063] In equation (1-1), the nitrogen atom N has a positive charge. ＋ And, an oxygen atom O that has a negative charge － The number of skeletal atoms connecting and is preferably within a specific range. Hereinafter, "positively charged nitrogen atoms N ＋ And, an oxygen atom O that has a negative charge － The number of skeletal atoms that connect and is sometimes called the "number of intercharge atoms." This number of intercharge atoms is the number of positively charged nitrogen atoms in equation (1-1) N ＋ And, an oxygen atom O that has a negative charge －This represents the number of skeletal atoms in the shortest molecular skeleton connecting and . Furthermore, "shortest" molecular skeleton means that it contains the fewest number of skeletal atoms. The range of the number of intercharge atoms in formula (1-1) is preferably 3 or more, more preferably 4 or more, preferably 6 or less, and more preferably 4 or less.

[0064] Among those mentioned above, the first ligand is preferably the one represented by formula (1-3).

[0065]

[0066] In equation (1-3), R ａ１ , R ａ２ , R ａ３ , R ａ５ As stated above, in equation (1-3), n ａ１ represents an integer between 1 and 5, preferably between 1 and 3, and more preferably 2.

[0067] A concrete example of the first ligand is the compound represented by the following formula (a1). The compound of formula (a1) may have stereoisomers, and any of these stereoisomers can be used.

[0068]

[0069] The first ligand may be used alone or in combination of two or more types.

[0070] The amount of the first ligand is preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 15% by weight or more, preferably 70% by weight or less, more preferably 50% by weight or less, and even more preferably 40% by weight or less, based on 100% by weight of the quantum dot composite. When the amount of the first ligand is within the above range, the photostability can be effectively improved.

[0071] The amount of the first ligand is preferably 10 parts by weight or more, more preferably 15 parts by weight or more, even more preferably 20 parts by weight or more, preferably 120 parts by weight or less, more preferably 90 parts by weight or less, even more preferably 80 parts by weight or less, and particularly preferably 70 parts by weight or less, per 100 parts by weight of quantum dots. When the amount of the first ligand is within the above range, the photostability can be effectively improved.

[0072] The amount of the first ligand is preferably 0.10 times or more, preferably 0.15 times or more, more preferably 0.20 times or more, preferably 1.0 times or less, more preferably 0.95 times or less, and even more preferably 0.90 times or less, relative to the amount of quantum dots, on a basis of amount of substance. When the amount of the first ligand is within the above range, the photostability can be effectively improved.

[0073] The amount of the first ligand is preferably 0.2 times or more, more preferably 0.4 times or more, even more preferably 0.5 times or more, preferably 20.0 times or less, more preferably 10.0 times or less, and even more preferably 3.0 times or less, relative to the amount of the second ligand, on a molar basis. When the amount of the first ligand is within the above range, photostability can be effectively improved.

[0074] The total amount of the first ligand and the second ligand is preferably 0.01 times or more, more preferably 0.1 times or more, even more preferably 0.2 times or more, preferably 5.0 times or less, more preferably 2.0 times or less, and even more preferably 1.0 times or less, relative to the amount of quantum dots, on a basis of amount of substance. When the total amount of the first ligand and the second ligand is within the above range, the photostability can be effectively improved.

[0075] (Second ligand) The second ligand is represented by the following formula (2-1).

[0076]

[0077] In equation (2-1), R ｂ１ R represents a monovalent aliphatic hydrocarbon group having 7 or more carbon atoms, which may have substituents. ｂ１The range of carbon atoms in the monovalent aliphatic hydrocarbon group is usually 7 or more, preferably 10 or more, more preferably 12 or more, even more preferably 14 or more, preferably 40 or less, more preferably 30 or less, and even more preferably 20 or less. Here, the number of carbon atoms in the monovalent aliphatic hydrocarbon group does not include the number of carbon atoms in substituents.

[0078] R ｂ１ The monovalent aliphatic hydrocarbon group in this expression may be linear or cyclic. Furthermore, the monovalent aliphatic hydrocarbon group may be an aliphatic saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group. Examples of monovalent aliphatic hydrocarbon groups include alkyl groups such as heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl groups.

[0079] R ｂ１ Examples of substituents that a monovalent aliphatic hydrocarbon group may have include R ａ４ Examples of substituents that may be present on a divalent aliphatic hydrocarbon group are the same. There may be one type of substituent or two or more types.

[0080] Among those mentioned above, R ｂ１ The group is preferably a monovalent aliphatic hydrocarbon group having 7 or more carbon atoms without substituents, more preferably a monovalent aliphatic saturated hydrocarbon group having 7 or more carbon atoms without substituents, even more preferably a monovalent linear aliphatic saturated hydrocarbon group having 7 or more carbon atoms without substituents, even more preferably an alkyl group having 7 or more carbon atoms, even more preferably a dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, or octadecyl group, and particularly preferably a hexadecyl group.

[0081] In equation (2-1), R ｂ２ and R ｂ３ Each of these independently represents a hydrogen atom or a monovalent aliphatic hydrocarbon group which may have substituents. ｂ２ and Ｒｂ３The range of carbon atoms in the monovalent aliphatic hydrocarbon group is usually 1 or more, preferably 40 or less, more preferably 30 or less, even more preferably 20 or less, even more preferably 10 or less, and particularly preferably 6 or less. The monovalent aliphatic hydrocarbon group may be linear or cyclic. Furthermore, the monovalent aliphatic hydrocarbon group may be an aliphatic saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group. Examples of monovalent aliphatic hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl groups.

[0082] R ｂ２ and R ｂ３ In this context, an example of a substituent that a monovalent aliphatic hydrocarbon group may have is R ａ４ Examples of substituents that may be present on a divalent aliphatic hydrocarbon group are the same. There may be one type of substituent or two or more types.

[0083] Among those mentioned above, R ｂ２ and R ｂ３ The hydrogen atom and the substituent-free monovalent aliphatic hydrocarbon group are preferred, the hydrogen atom and alkyl group are more preferred, alkyl group is even more preferred, methyl group, ethyl group, propyl group, butyl group, pentyl group and hexyl group are even more preferred, and the methyl group is particularly preferred. ｂ２ and R ｂ３ They may be the same or they may be different.

[0084] In equation (2-1), R ｂ４ R represents a divalent aliphatic hydrocarbon group which may have substituents. ｂ４ The range of carbon atoms in the divalent aliphatic hydrocarbon group in is usually 1 or more, preferably 2 or more, preferably 6 or less, more preferably 4 or less, and even more preferably 3 or less. Also, R ｂ４ The number of carbon atoms in the divalent aliphatic hydrocarbon group in R is ｂ１ It is preferable that R is smaller than the number of carbon atoms in the monovalent aliphatic hydrocarbon group. ｂ４ The number of carbon atoms in the divalent aliphatic hydrocarbon group, and R ｂ１ In this context, the number of carbon atoms in a monovalent aliphatic hydrocarbon group does not include the number of carbon atoms in substituents.

[0085] R ｂ４ The divalent aliphatic hydrocarbon group in this compound may be linear or cyclic. Furthermore, the divalent aliphatic hydrocarbon group may be an aliphatic saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group. ｂ４ An example of a divalent aliphatic hydrocarbon group in R is ａ４ The same example as the divalent aliphatic hydrocarbon group in [the relevant context] can be cited.

[0086] R ｂ４ Examples of substituents that a divalent aliphatic hydrocarbon group may have include R ａ４ Examples of substituents that may be present on a divalent aliphatic hydrocarbon group are the same. There may be one type of substituent or two or more types.

[0087] Among those mentioned above, R ｂ４ The group is preferably an unsubstituted divalent aliphatic hydrocarbon group, more preferably an unsubstituted divalent aliphatic saturated hydrocarbon group, even more preferably an alkylene group, even more preferably a methylene group, an ethylene group, a propylene group, and a butylene group, even more preferably an ethylene group and a propylene group, and particularly preferably a propylene group.

[0088] In equation (2-1), X ｂ X represents a divalent group. ｂ From the viewpoint of effectively improving photostability, it is preferable that the number of atoms contained is small. For example, X ｂ The total number of skeletal atoms other than hydrogen atoms contained in is usually 1 or more, preferably 2 or more, preferably 6 or less, more preferably 4 or less, and even more preferably 3 or less.

[0089] X ｂ This is the oxygen atom at the end of equation (2-1) (a negatively charged oxygen atom O － It has a first atom bonded to it. ｂ In this, the first atom is R ｂ４ It is preferable that it is bonded to X. ｂ These are the oxygen atom and R shown in formula (2-1). ｂ４ It is preferable to include a first atom bonded to both sides. ｂThe first atom is preferably selected from the group consisting of carbon atoms, sulfur atoms, and phosphorus atoms, and more preferably carbon atoms and sulfur atoms.

[0090] X ｂ In this arrangement, it is preferable that a heteroatom is bonded to the first atom, more preferably an oxygen atom or a sulfur atom, and even more preferably an oxygen atom. Among these, it is particularly preferable that an oxo group is bonded to the first atom. ｂ Preferred examples include carbonyl groups and sulfonyl groups.

[0091] In equation (2-1), the nitrogen atom N has a positive charge. ＋ And, an oxygen atom O that has a negative charge － The number of skeletal atoms connecting and (i.e., the number of intercharge atoms) is preferably within a specific range. Specifically, the range of the number of intercharge atoms in formula (2-1) is preferably 2 or more, more preferably 3 or more, preferably 6 or less, more preferably 5 or less, and even more preferably 4 or less.

[0092] Among those mentioned above, the second ligand is preferably one represented by formula (2-2) or formula (2-3).

[0093]

[0094] In equations (2-2) and (2-3), R ｂ１ , R ｂ２ and R ｂ３ As stated above, n ｂ１ and n ｂ２ Each of these independently represents an integer between 1 and 5, preferably between 2 and 4, and more preferably between 2 and 3.

[0095] Specific examples of the second ligand include compounds represented by the following formulas (b1) to (b5).

[0096]

[0097] The second ligand may be used alone or in combination of two or more types.

[0098] The amount of the second ligand is preferably 0.2% by weight or more, more preferably 0.5% by weight or more, even more preferably 1.0% by weight or more, preferably 50% by weight or less, more preferably 30% by weight or less, and even more preferably 20% by weight or less, based on 100% by weight of the quantum dot composite. When the amount of the second ligand is within the above range, the photostability can be effectively improved.

[0099] The amount of the second ligand is preferably 0.5 parts by weight or more, more preferably 1.0 part by weight or more, even more preferably 2.0 parts by weight or more, preferably 70 parts by weight or less, more preferably 50 parts by weight or less, and even more preferably 30 parts by weight or less, per 100 parts by weight of quantum dots. When the amount of the second ligand is within the above range, the photostability can be effectively improved.

[0100] The amount of the second ligand is preferably 0.01 times or more, preferably 0.02 times or more, more preferably 0.10 times or more, preferably 0.50 times or less, more preferably 0.45 times or less, and even more preferably 0.40 times or less, relative to the amount of quantum dots, on a basis of amount of substance. When the amount of the second ligand is within the above range, the photostability can be effectively improved.

[0101] (Average particle size of quantum dot composites) Quantum dot composites are typically manufactured and used as particles containing quantum dots, a first ligand, and a second ligand. The average particle size range of these quantum dot composites is preferably 1 nm or more, more preferably 2 nm or more, even more preferably 4 nm or more, preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 16 nm or less. When the average particle size of the quantum dot composite is within the above range, high solvent dispersibility can be imparted. Good solvent dispersibility allows for good processing into molded articles. The average particle size of the quantum dot composite can be measured by the same method as the average particle size of quantum dots.

[0102] (Luminescence capability of quantum dot composites) Quantum dot composites typically possess the same luminescence capability as quantum dots, and can emit light in the visible to near-infrared wavelength range (300 nm to 1000 nm). Therefore, for example, when a quantum dot composite is made to emit light by photoexcitation, the wavelength range of the excitation light can be the same as the wavelength range of the excitation light for quantum dots.

[0103] Generally, quantum dots tend to experience a decrease in luminescence quantum yield (PLQY) over time when illuminated with light. In contrast, the quantum dot composite described above exhibits a small decrease in luminescence quantum yield (PLQY) due to light illumination. Therefore, the quantum dot composite can achieve excellent photostability. Preferably, the quantum dot composite is exposed to, for example, 100 mW / cm². ２ It can exhibit excellent stability against high-intensity light.

[0104] The degree of decrease in the aforementioned quantum luminescence yield (PLQY) can be evaluated, for example, by a photoresistance test. Specifically, first, excitation light is irradiated onto the quantum dot composite, and the luminescence intensity "PLQY" of the light emitted by the quantum dot composite is evaluated. ｂｅｆ The following is measured: Then, the quantum dot composite is irradiated with light of a wavelength of 450 nm at an intensity of 100 mW / cm². ２ A light endurance test will be conducted by irradiating the quantum dot composite with light for 5 hours. After that, under the same conditions as the measurement before the light endurance test, the quantum dot composite will be irradiated with excitation light, and the emission intensity of the light emitted by the quantum dot composite, "PL ａｆｔ The luminescence intensity PL before the light durability test is measured. ｂｅｆ and the luminescence intensity PL after the light durability test ａｆｔ Using the following formula (M1), the maintenance rate of luminescence intensity ΔPL is calculated. The maintenance rate of luminescence intensity ΔPL of the above-mentioned quantum dot composite is preferably 0.6 or higher, more preferably 0.7 or higher, and even more preferably 0.8 or higher. ΔPL = PL ａｆｔ / PL ｂｅｆ (M1)

[0105] (Method for manufacturing quantum dot composites) A ​​quantum dot composite can be manufactured by a method comprising: (I) a step of manufacturing quantum dots; and (II) a step of mixing quantum dots, a first ligand, and a second ligand.

[0106] There are no restrictions on the method used to produce quantum dots in step (I). For example, quantum dots can be produced by a method that includes preparing a precursor solution containing the raw materials for quantum dots and a polar solvent, and then mixing the precursor solution with a nonpolar solvent to obtain quantum dots.

[0107] Typically, the raw materials for quantum dots include compounds containing the A-site material, compounds containing the B-site material, and compounds containing the X-site material, as described above. For example, compounds containing the A-site material and the X-site material, as well as compounds containing the B-site material and the X-site material, may be used.

[0108] Examples of compounds containing A-site material and X-site material include the halide (AX) of the A-site material. Examples of the halide (AX) of the A-site material include a monovalent cation A ＋ And, monovalent halide ion X － A compound consisting of the above is an example. ＋ Alkali metal ions such as cesium ions, rubidium ions, potassium ions, sodium ions, and lithium ions, and X － Examples include compounds consisting of chloride ions, bromide ions, and halide ions such as iodide ions. Another specific example is A ＋Examples of compounds include those comprising an organic cation and the aforementioned halide ion. Examples of compounds containing an A-site material comprising an organic cation and a halide ion include methylamine hydrohalide (MAX), ethylamine hydrohalide (EAX), formamidine hydrohalide (FAX), and guanidine hydrohalide (GAX). Among these, cesium chloride, cesium bromide, cesium iodide, methylammonium chloride, methylammonium bromide, methylammonium iodide, ethylammonium chloride, ethylammonium bromide, ethylammonium iodide, formamidine hydrochloride, formamidine hydrobromide, formamidine hydroiodide, guanidine hydrochloride, guanidine hydrobromide, and guanidine hydroiodide are preferred. These compounds may be used individually or in combination of two or more.

[0109] Examples of compounds containing B-site material and X-site material include the halide of the B-site material (BX ２ ) are examples. B-site material halides (BX ２ For example, divalent metal ions B ２＋ And, monovalent halide ion X － A compound consisting of the above is B. ２＋ Examples include compounds consisting of divalent metal ions such as lead ions, germanium ions, and tin ions, and the aforementioned halide ions. Among these, lead(II) bromide (PbBr) is a good example. ２ ), lead(II) iodide (PbI ２ ), lead(II) chloride (PbCl ２ ), tin(II) bromide (SnBr ２ ), tin(II) iodide (SnI ２ ), tin(II) chloride (SnCl ２ ), germanium(II) bromide (GeBr ２ ), germanium(II) iodide (GeI ２ ) and germanium(II) chloride (GeCl ２ ) is preferred. These compounds may be used individually or in combination of two or more.

[0110] Halides from site A (AX) and halides from site B (BX) ２ ) Mixing ratio (AX:BX ２ The molar ratio is typically 1:10 to 10:1, preferably 1:3 to 3:1, and more preferably 1:1.5 to 1.5:1. When the mixing ratio is within the above range, the valence of the metal elements in the perovskite crystal structure of the quantum dots can be made uniform, thereby effectively suppressing the decrease in luminescence quantum yield (PLQY) due to illumination with light.

[0111] There is no limit to the amount of quantum dot raw material used, as long as quantum dots can be obtained. In one example, the lower limit of the concentration of the quantum dot raw material in the precursor solution is preferably 0.02 mol / L or higher, more preferably 0.05 mol / L or higher, and even more preferably 0.10 mol / L or higher. The upper limit of the concentration of the quantum dot raw material in the precursor solution is preferably 10.0 mol / L or lower, more preferably 3.0 mol / L or lower, and even more preferably 1.0 mol / L or lower. The above concentrations are usually adjusted to be below the solubility of the quantum dot raw material so that the raw material is completely dissolved.

[0112] As the polar solvent, a solvent capable of dissolving the quantum dot precursor is usually used. Furthermore, it is preferable that this polar solvent is miscible with the non-polar solvent mixed with the precursor solution. A non-protic organic solvent is preferred as this polar solvent. This polar solvent preferably has a liquid dielectric constant of 20 μS / cm or higher, and more preferably 30 μS / cm or higher. The upper limit of the liquid dielectric constant can be, for example, 90 μS / cm or less. The liquid dielectric constant can be measured using a liquid dielectric meter (for example, "Model 871" manufactured by Sanyo Trading Co., Ltd.) at a frequency of 10 kHz and 23°C. Examples of polar solvents include N,N-dimethylformamide (DMF, 38 μS / cm), N-methylpyrrolidone (NMP, 32 μS / cm), 4-butanolide (GBL, 43 μS / cm), dimethyl sulfoxide (DMSO, 47 μS / cm), propylene carbonate (PC, 64 μS / cm), and acetonitrile (37 μS / cm). Polar solvents may be used individually or in combination of two or more.

[0113] The precursor solution may contain any organic ligand in combination with the quantum dot raw materials and polar solvent. Any organic ligand is a coordinating organic compound that can contribute to uniform particle size and the filling of surface defects during the production of quantum dots. When the precursor solution contains any organic ligand, a polar solvent capable of dissolving the organic ligand is typically used.

[0114] Examples of arbitrary organic ligands include organic acid ligands that can form coordinate bonds with cations that form quantum dots. Here, the "cation that forms quantum dots" is defined by formula ABX ３ This corresponds to the A-site and B-site materials of the perovskite-type crystal structure represented by [formula]. Examples of these optional organic ligands include organic acid compounds.

[0115] Examples of organic acid ligands include organic carboxylic acids, organic sulfonic acids, organic sulfinic acids, and phosphorus oxoacid compounds (organophosphonic acids, organic phosphonates, organic phosphinic acids, etc.). Specific examples include organic carboxylic acids such as oleic acid, stearic acid, palmitic acid, glutaric acid, sebacic acid, benzoic acid, and 3,4,5-tri(2-propenoxy)benzoic acid; organic sulfinic acids such as benzenesulfinic acid; organic phosphonic acids such as octylphosphonic acid, tetradecylphosphonic acid, and tri-n-octylphosphine oxide; and organic phosphinic acids such as di-tert-octylphosphine and diisooxylphosphine.

[0116] Examples of arbitrary organic ligands include organic base ligands that can form coordinate bonds with anions that form quantum dots. Here, "anions that form quantum dots" refers to those of formula ABX ３ This corresponds to an X-site material of a perovskite-type crystal structure represented by ABX. Furthermore, an example of an arbitrary organic ligand is an organic base ligand that forms a coordinate bond by substituting the cation portion of the organic base ligand for the monovalent cation that forms the quantum dot. Here, "the monovalent cation that forms the quantum dot" refers to the organic base ligand represented by formula ABX. ３ This corresponds to the A-site material of the perovskite-type crystal structure represented by [formula].

[0117] Examples of organic base ligands include aliphatic amines, aromatic amines, and quaternary ammonium salts. Specific examples include aliphatic amines with 3 to 16 carbon atoms such as oleylamine, propylamine, butylamine, pentylamine, octylamine, hexadecylamine, and octadecylamine; aromatic amines with 6 to 34 carbon atoms such as aniline, benzylamine, phenethylamine, 3-phenyl-2-propene-1-amine, phenylmethylamine, 2,2'-iminodibenzoic acid, 3-phenylpropylamine, 4-phenylbutylamine, naphthylamine, 4-aminobiphenyl, and 3,4,5-tris(propa-2-en-1-yloxy)benzylamine; and aliphatic tetraammonium salts such as didecyldimethylammonium salt, benzyltrimethylammonium bromide, 3-(N,N-dimethyloctadecylammonium)propanesulfonate salt, and stearyltrimethylammonium salt.

[0118] Any organic ligand may be used alone or in combination of two or more types. Furthermore, there is no limit to the amount of any organic ligand, and it may be appropriately adjusted within a range that allows for uniformity of quantum dot particle size and compensation of surface defects.

[0119] Step (I) typically involves mixing the raw materials for the quantum dots and a polar solvent, along with any organic ligands as needed, to obtain a precursor solution. Subsequently, step (I) involves mixing the precursor solution with a nonpolar solvent to obtain quantum dots.

[0120] As the nonpolar solvent to be mixed with the precursor solution, a solvent that is miscible with the polar solvents mentioned above is usually used. Furthermore, the nonpolar solvent is preferably an organic solvent with a liquid dielectric constant of 10 μS / cm or less. Preferred nonpolar solvents include, for example, pentane (1.84 μS / cm), hexane (1.88 μS / cm), cyclohexane (2.02 μS / cm), octane (2.00 μS / cm), decalin (2.43 μS / cm), methylcyclohexane (2.02 μS / cm), xylene (2.58 μS / cm), ethyl methyl carbonate (EMC, 2.92 μS / cm), dimethyl carbonate (DMC, 3.03 μS / cm), diethyl carbonate (DEC, 2.82 μS / cm), and propylene glycol monomethyl ether acetate (PMA, 8. Examples include 0.3 μS / cm), ethyl acetate (6.02 μS / cm), methyl acetate (6.65 μS / cm), chloroform (4.92 μS / cm), chlorobenzene (5.65 μS / cm), toluene (2.38 μS / cm), benzene (2.28 μS / cm (25°C)), dichloromethane (8.90 μS / cm), diethyl ether (4.10 μS / cm), dibutyl ether (3.06 μS / cm)), cyclopentyl methyl ether (CPME, 4.28 μS / cm), and tetrachloromethane (2.24 μS / cm). Nonpolar solvents may be used individually or in combination of two or more. When two or more nonpolar solvents are used, it is preferable that the mixed solvent obtained after mixing them has a liquid dielectric constant of 10 μS / cm or less. Furthermore, the nonpolar solvent may contain any of the above-mentioned organic ligands.

[0121] The mixing of the precursor solution and the nonpolar solvent is preferably carried out at a specific range of liquid temperatures. Specifically, this range of liquid temperatures is preferably 10°C or higher, more preferably 15°C or higher, even more preferably 20°C or higher, preferably 40°C or lower, more preferably 35°C or lower, and even more preferably 30°C or lower. When mixed at this range of liquid temperatures, quantum dots can be synthesized stably.

[0122] Quantum dots are obtained by mixing a precursor solution with a nonpolar solvent. It is preferable to add the precursor solution to the nonpolar solvent either all at once or over time. The nonpolar solvent generally functions as a poor solvent, making it difficult to dissolve quantum dots. Therefore, a suspension is usually obtained by mixing the precursor solution with the nonpolar solvent, and this suspension contains quantum dots. Thus, quantum dots can be obtained as the solid component of the suspension. Consequently, quantum dots can be obtained by recovering the solid component from the suspension using a recovery method such as centrifugation. If the precursor solution or nonpolar solvent contains any organic ligand, the obtained quantum dots may have any organic ligand coordinated to them.

[0123] A method for manufacturing a quantum dot composite includes a step (I) in which quantum dots are manufactured, followed by a step (II) in which the quantum dots, a first ligand, and a second ligand are mixed. In step (II), the first and second ligands typically coordinate to the quantum dots, resulting in a quantum dot composite. If an arbitrary organic ligand is coordinated to the quantum dots obtained in step (I), the quantum dot composite may contain the arbitrary organic ligand, for example, the arbitrary organic ligand coordinated to the quantum dots. However, typically, the arbitrary organic ligand is detached from the quantum dot in step (II). Therefore, typically, the particle dot composite contains no arbitrary organic ligand, or only a small amount of it.

[0124] The quantum dot, the first ligand, and the second ligand may be mixed simultaneously or sequentially. Preferably, step (II) includes mixing the quantum dot and the second ligand to obtain an intermediate particle, and mixing the intermediate particle and the first ligand to obtain a quantum dot composite. This preferred method will be described below.

[0125] As described above, step (II) preferably includes mixing the quantum dots and the second ligand. At this time, from the viewpoint of good dispersion of the quantum dots and promoting coordination of the second ligand to the quantum dots, it is preferable to mix the quantum dots with the second ligand while they are dispersed in the redispersion medium. As the redispersion medium for dispersing the particle dots, a nonpolar solvent as described in step (I) may be used. The liquid dielectric constant of this nonpolar solvent is preferably 10 μS / cm or less. Furthermore, one type of redispersion medium may be used alone, or two or more types may be used in combination. Specifically, it is preferable to mix the quantum dots and the redispersion medium to obtain a quantum dot dispersion, and then mix this quantum dot dispersion with the second ligand. The concentration range of the quantum dots contained in the quantum dot dispersion may be a range in which the quantum dots can be well dispersed, for example, it may be 0.0002 mol / L or more and 0.065 mol / L or less.

[0126] On the other hand, from the viewpoint of promoting the coordination of the second ligand to the quantum dot, it is preferable to mix the second ligand with the quantum dot in a state where it is dissolved in a suitable solvent. Specifically, it is preferable to mix the second ligand and the solvent to obtain a second ligand solution, and then mix this second ligand solution with the quantum dot. As the solvent for the second ligand solution, any solvent that can dissolve the second ligand can be used, for example, an organic solvent having a liquid dielectric constant of 9 μS / cm or more can be used. In particular, from the viewpoint of effectively removing any organic ligands coordinated to the quantum dot and promoting the coordination of the second ligand, it is preferable to use a polar solvent as the solvent for the second ligand solution. As the polar solvent, the polar solvent described in step (I) can be used. The liquid dielectric constant range of this polar solvent is preferably 20 μS / cm or more, more preferably 30 μS / cm or more, and preferably 90 μS / cm or less. The solvent for the second ligand solution may be used alone or in combination of two or more types. The concentration of the second ligand in the second ligand solution can be adjusted within the range in which the second ligand can dissolve in the solvent. When a polar solvent is used as the solvent for the second ligand solution, from the viewpoint of suppressing the dissolution of quantum dots and increasing the yield of the quantum dot composite, it is preferable that the concentration of the polar solvent in the second ligand solution be low, and therefore that the concentration of the second ligand be high. In one example, the range of the concentration of the second ligand in the second ligand solution may be 0.001 mol / L or more and 100 mol / L or less.

[0127] When using a quantum dot dispersion and a second ligand solution, step (II) preferably includes mixing the quantum dot dispersion and the second ligand solution. Mixing the quantum dot dispersion and the second ligand solution yields a suspension containing intermediate particles as solid matter. Therefore, intermediate particles can be obtained by recovering the solid matter from the suspension using a recovery method such as centrifugation. The resulting intermediate particles contain quantum dots and a second ligand. In these intermediate particles, the second ligand is usually coordinated to the quantum dots.

[0128] After obtaining intermediate particles, step (II) includes mixing the intermediate particles and the first ligand. At this time, from the viewpoint of good dispersion of the intermediate particles and promoting the coordination of the first ligand to the quantum dots in the intermediate particles, it is preferable to mix the intermediate particles with the first ligand while they are dispersed in a redispersion medium. As the redispersion medium for dispersing the intermediate particles, a nonpolar solvent as described in step (I) may be used. The liquid dielectric constant of this nonpolar solvent is preferably 10 μS / cm or less. Furthermore, one type of redispersion medium may be used alone, or two or more types may be used in combination. Specifically, it is preferable to mix the intermediate particles and the redispersion medium to obtain an intermediate particle dispersion, and then mix this intermediate particle dispersion with the first ligand. The concentration range of the quantum dots contained in the intermediate particle dispersion may be a range in which the quantum dots can be well dispersed, for example, it may be 0.0002 mol / L or more and 0.065 mol / L or less.

[0129] On the other hand, from the viewpoint of promoting the coordination of the first ligand to the quantum dot, it is preferable to mix the first ligand with the quantum dot in a dissolved state in a suitable solvent. Specifically, it is preferable to mix the first ligand and the solvent to obtain a first ligand solution, and then mix this first ligand solution with the quantum dot. As the solvent for the first ligand solution, any solvent capable of dissolving the first ligand can be used, for example, a nonpolar solvent can be used. As the nonpolar solvent for dissolving the first ligand, the nonpolar solvent described in step (I) may be used. The liquid dielectric constant of this nonpolar solvent is preferably 10 μS / cm or less. Furthermore, the solvent for the first ligand solution may be used alone or in combination of two or more types. The concentration of the first ligand in the first ligand solution may be within the range in which the first ligand can dissolve in the solvent, for example, it may be 0.001 mol / L or more and 0.25 mol / L or less.

[0130] When using an intermediate particle dispersion and a first ligand solution, step (II) preferably includes mixing the intermediate particle dispersion and the first ligand solution. The mixing yields a quantum dot composite. Typically, a quantum dot composite dispersion is obtained, which includes a dispersion medium and the quantum dot composite dispersed in the dispersion medium. The quantum dot composite may be stored and used in the state of this quantum dot composite dispersion. Alternatively, the quantum dot composite may be recovered from the quantum dot composite dispersion by a recovery method such as centrifugation.

[0131] The method for manufacturing the quantum dot composite may include any additional steps in addition to the steps described above.

[0132] The intermediate particles obtained in step (II) described above may contain not only intermediate particles with a preferred particle size range, but also coarse powder with a larger particle size. Therefore, the method for producing the quantum dot composite may include an optional step in step (II) to remove these coarse particles. For example, the intermediate particles are dispersed in a suitable dispersion medium such as a nonpolar solvent to obtain a pre-dispersion. When this pre-dispersion is centrifuged, the intermediate particles with a preferred particle size usually disperse in the supernatant, while the coarse powder settles. Therefore, by removing the settled coarse powder from the pre-dispersion after centrifugation, a dispersion containing intermediate particles with a preferred particle size can be obtained.

[0133] Furthermore, the quantum dots obtained in step (I) may contain not only quantum dots with a preferred particle size range, but also coarse particles with a larger particle size. Therefore, the method for producing the quantum dot composite may include a step in step (I) to remove these coarse particles. The removal of coarse particles from quantum dots may be carried out by the same method as the removal of coarse particles from intermediate particles.

[0134] <Quantum Dot Composite Dispersion> The quantum dot composite dispersion according to one embodiment of the present invention comprises the above-described quantum dot composite and an organic solvent. In the quantum dot composite dispersion, the quantum dot composite is dispersed in the organic solvent. The quantum dot composite dispersion can suppress the aggregation of the quantum dot composite, thereby suppressing the decrease in the luminescence quantum yield (PLQY) due to such aggregation. Furthermore, since the decrease in the luminescence quantum yield (PLQY) due to illumination with light can be suppressed in the quantum dot composite dispersion, high photostability can be obtained.

[0135] The amount of quantum dots in the quantum dot composite dispersion is preferably 0.1 mg / mL or more, more preferably 0.5 mg / mL or more, even more preferably 1.0 mg / mL or more, preferably 32.0 mg / mL or less, more preferably 16.0 mg / mL or less, and even more preferably 12.0 mg / mL or less. This is because setting the amount of quantum dots contained in the quantum dot composite in the quantum dot composite dispersion within the above range improves the dispersibility of the quantum dot composite.

[0136] Furthermore, the amount of quantum dot complex in the quantum dot complex dispersion can be, for example, 0.5 mg / mL or more and 60 mg / mL or less.

[0137] As the organic solvent, any solvent capable of dispersing the quantum dot composite can be used, and a nonpolar solvent is preferred. As the nonpolar solvent, the one described in step (I) of the method for producing the quantum dot composite can be used. This nonpolar solvent is preferably an organic solvent with a liquid dielectric constant of 10 μS / cm or less. Furthermore, one type of organic solvent may be used alone, or two or more types may be used in combination.

[0138] The quantum dot composite dispersion may contain any additional components in combination with the quantum dot composite and the organic solvent. Examples of optional components include liquid dielectric constant modifiers, radical scavengers, and ultraviolet absorbers. Any one component may be used alone, or two or more components may be used in combination.

[0139] The quantum dot complex contained in the quantum dot complex dispersion has luminescence capability, as described above. This quantum dot complex also has excellent photostability, as mentioned above. Therefore, the quantum dot complex dispersion can reduce the degree of decrease in the luminescence quantum yield (PLQY) of the quantum dot complex due to illumination with light. Particularly preferably, for example, 100 mW / cm². ２ It can exhibit excellent stability against high-intensity light.

[0140] The degree of decrease in the aforementioned quantum luminescence yield (PLQY) can be evaluated, for example, by a photoendurance test. Specifically, first, excitation light is shone onto a quantum dot composite dispersion, and the luminescence intensity "PLQY" of the light emitted from the quantum dot composite dispersion is evaluated. ｂｅｆ The following is measured: Then, the quantum dot composite dispersion is irradiated with light of a wavelength of 450 nm at an intensity of 100 mW / cm². ２ A photoresistance test will be conducted by irradiating the quantum dot composite dispersion with excitation light for 5 hours. After that, under the same conditions as the measurement before the photoresistance test, the emission intensity of the light emitted from the quantum dot composite dispersion, "PL ａｆｔ The luminescence intensity PL before the light durability test is measured. ｂｅｆ and the luminescence intensity PL after the light durability test ａｆｔ Using the above formula (M1), the maintenance rate of luminescence intensity ΔPL is calculated. The maintenance rate of luminescence intensity ΔPL of the quantum dot composite dispersion is preferably 0.6 or higher, more preferably 0.7 or higher, and even more preferably 0.8 or higher.

[0141] The quantum dot complex dispersion may be produced, for example, by a method including mixing the quantum dot complex and an organic solvent. Alternatively, when producing a quantum dot complex dispersed in an organic solvent by the above-described method, the resulting quantum dot complex dispersion containing the quantum dot complex may be used as is.

[0142] <Quantum Dot Molded Body> A molded body according to one embodiment of the present invention includes the above-described quantum dot composite and a polymer. Hereinafter, this molded body may be referred to as a "quantum dot molded body". Such a quantum dot molded body includes a resin material containing the quantum dot composite and the polymer, or it may contain only the resin material. The polymer can usually function as a binder that binds the quantum dot composite. Therefore, in a quantum dot molded body, the quantum dot composite can be maintained in a dispersed state within the polymer. Consequently, aggregation of the quantum dot composite can be suppressed in a quantum dot molded body, and thus the decrease in the luminescence quantum yield (PLQY) due to such aggregation can be suppressed. Furthermore, since the decrease in the luminescence quantum yield (PLQY) due to illumination with light can be suppressed in a quantum dot molded body, high photostability can be obtained.

[0143] The amount of quantum dot composite may be adjusted according to the application of the quantum dot molded body. Alternatively, the amount of quantum dot composite may be adjusted based on, for example, the amount of quantum dots contained in the quantum dot composite. In one example, from the viewpoint of luminescence, the range of the amount of quantum dots is preferably 0.01 parts by weight or more, more preferably 0.02 parts by weight or more, even more preferably 0.03 parts by weight or more, preferably 50 parts by weight or less, more preferably 25 parts by weight or less, and even more preferably 10 parts by weight or less, per 100 parts by weight of the quantum dot molded body.

[0144] Furthermore, a preferred example of the amount of quantum dot composite is 0.01% by weight or more, but may also be 0.05% by weight or more, or 0.1% by weight or more, based on 100% by weight of the quantum dot molded body. The upper limit of the amount of quantum dot composite is 15% by weight or less, preferably 10% by weight or less, and more preferably 1% by weight or less, based on 100% by weight of the quantum dot molded body.

[0145] As the polymer, a resin capable of binding quantum dot composites can be used. Examples of polymers include acetate polymers such as triacetylcellulose, polyesters, polyethersulfones, polycarbonates, polyamides, polyimides, polyolefins, cyclic olefin polymers, and (meth)acrylic polymers. The polymer may be used alone or in combination of two or more types. Among these, cyclic olefin polymers and (meth)acrylic polymers are preferred, and cyclic olefin polymers are even more preferred from the viewpoint of improving atmospheric stability. Therefore, the polymer preferably contains cyclic olefin polymers, and may contain only cyclic olefin polymers.

[0146] Cyclic olefin polymers can be polymers or hydrides thereof obtained by polymerization reactions of cyclic olefin monomers. Cyclic olefin polymers may be homopolymers or copolymers. Cyclic olefin polymers may have a cyclic structure within their molecule. Typically, cyclic olefin polymers have an alicyclic structure in the repeating units of the polymer. Cyclic olefin polymers can be polymers having an alicyclic structure in the main chain, polymers having an alicyclic structure in the side chains, polymers having an alicyclic structure in both the main chain and side chains, and mixtures of two or more of these in any ratio. From the viewpoint of mechanical strength and heat resistance, cyclic olefin polymers containing an alicyclic structure in the main chain are preferred.

[0147] Examples of alicyclic structures include saturated alicyclic hydrocarbon (cycloalkane) structures and unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structures. Among these, cycloalkane and cycloalkene structures are preferred from the viewpoint of mechanical strength and heat resistance, and cycloalkane structures are particularly preferred.

[0148] When the number of carbon atoms constituting the alicyclic structure is preferably 4 or more, more preferably 5 or more, preferably 30 or less, more preferably 20 or less, and particularly preferably 15 or less, a high degree of balance is achieved in terms of mechanical strength, heat resistance, and moldability.

[0149] In cyclic olefin polymers, the proportion of structural units having an alicyclic structure to all structural units can be appropriately selected depending on the intended use. This proportion is preferably 55% by weight or more, more preferably 70% by weight or more, and even more preferably 90% by weight or more. When the proportion of structural units having an alicyclic structure to all structural units falls within this range, transparency and heat resistance are good.

[0150] Examples of cyclic olefin polymers include norbornene polymers; monocyclic cyclic olefin polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and their hydrides; and hydrides of vinyl aromatic hydrocarbon polymers. Among these, one or more selected from the group consisting of norbornene polymers; vinyl alicyclic hydrocarbon polymers and their hydrides; and hydrides of vinyl aromatic hydrocarbon polymers are more preferred due to their good transparency.

[0151] Examples of norbornene polymers include ring-opening polymers of monomers having a norbornene structure and their hydrides; addition polymers of monomers having a norbornene structure and their hydrides. Examples of ring-opening polymers of monomers having a norbornene structure include ring-opening homopolymers of one type of monomer having a norbornene structure, ring-opening copolymers of two or more types of monomers having a norbornene structure, and ring-opening copolymers of a monomer having a norbornene structure and any monomer copolymerizable therewith. Furthermore, examples of addition polymers of monomers having a norbornene structure include addition homopolymers of one type of monomer having a norbornene structure, addition copolymers of two or more types of monomers having a norbornene structure, and addition copolymers of a monomer having a norbornene structure and any monomer copolymerizable therewith. Among these, hydrides of ring-opening polymers of monomers having a norbornene structure, addition copolymers of monomers having a norbornene structure and α-olefins, and hydrides of addition copolymers of monomers having a norbornene structure and α-olefins are preferred. Furthermore, hydrides of ring-opening copolymers of two or more monomers having a norbornene structure, addition copolymers of monomers having a norbornene structure and α-olefins, and hydrides of addition copolymers of monomers having a norbornene structure and α-olefins are more preferred.

[0152] Examples of monomers having a norbornene structure include bicyclo[2.2.1]hept-2-ene (common name: norbornene), tricyclo[4.3.0.1 ２，５ Deca-3,7-diene (common name: dicyclopentadiene), 7,8-benzotricyclo[4.3.0.1 ２，５ Deca-3-ene (common name: metanotetrahydrofluorene), tetracyclo[4.4.0.1 ２，５ 1. ７，１０Examples include dodeca-3-ene (common name: tetracyclododecene) and derivatives of these compounds (for example, those having substituents on the ring). Here, examples of substituents include alkyl groups, alkylene groups, polar groups, etc. Multiple substituents may be bonded to the ring, either identical or different in nature. Monomers having a norbornene structure may be used individually or in combination of two or more types.

[0153] Examples of polar groups include heteroatoms or groups of atoms containing heteroatoms. Examples of heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, silicon atoms, and halogen atoms. Specific examples of polar groups include carboxyl groups, carbonyloxycarbonyl groups, epoxy groups, hydroxyl groups, oxy groups, ester groups, silanol groups, silyl groups, amino groups, nitrile groups, and sulfonic acid groups. Cyclic olefin polymers may or may not contain the above-mentioned polar groups, but it is more preferable that they do not contain polar groups.

[0154] Examples of monomers capable of ring-opening copolymerization with monomers having a norbornene structure include monocyclic olefin compounds such as cyclohexene, cycloheptene, and cyclooctene, and their derivatives; and cyclic conjugated dienes such as cyclohexadiene and cycloheptadiene, and their derivatives. Monomers capable of ring-opening copolymerization with monomers having a norbornene structure may be used individually or in combination of two or more types.

[0155] Ring-opening polymers of monomers having a norbornene structure can be produced, for example, by polymerizing or copolymerizing monomers in the presence of a ring-opening polymerization catalyst.

[0156] In addition copolymers of monomers having a norbornene structure and α-olefins, examples of α-olefins include α-olefins having 2 to 20 carbon atoms, such as ethylene, propylene, and 1-butene, and their derivatives. Among these, ethylene is preferred. One type of α-olefin may be used alone, or two or more types may be used in combination.

[0157] Addition polymers of monomers having a norbornene structure can be produced, for example, by polymerizing or copolymerizing monomers in the presence of an addition polymerization catalyst.

[0158] The hydrides of the ring-opening polymers and addition polymers described above can be produced, for example, by hydrogenating the carbon-carbon unsaturated bonds by preferably 90% or more in a solution of the ring-opening polymer or addition polymer in the presence of a hydrogenation catalyst containing a transition metal such as nickel or palladium.

[0159] Examples of norbornene polymer trade names include "ZEONOR" and "ZEONEX" from Nippon Zeon Corporation; "ARTON" from JSR Corporation; and "APPEL" from Mitsui Chemicals, Inc.

[0160] Examples of vinyl alicyclic hydrocarbon polymers include polymers of vinyl alicyclic hydrocarbon monomers such as vinylcyclohexene and vinylcyclohexane, and their hydrides; and hydrides of the aromatic ring portion of polymers of vinyl aromatic monomers. Furthermore, vinyl alicyclic hydrocarbon polymers may also be copolymers of vinyl alicyclic hydrocarbon monomers with any monomer and their hydrides; or hydrides of copolymers of vinyl aromatic monomers with any monomer. Examples of copolymers include random copolymers and block copolymers. Examples of block copolymers include diblock copolymers, triblock copolymers, or multiblock copolymers and graded block copolymers, and are not particularly limited.

[0161] As the vinyl alicyclic hydrocarbon polymer, hydrides of vinyl aromatic hydrocarbon polymers are preferred. A vinyl aromatic hydrocarbon polymer means a polymer containing repeating units [I] derived from aromatic vinyl compounds. "Repeating units derived from aromatic vinyl compounds" means repeating units having a structure obtained by polymerizing aromatic vinyl compounds. However, the polymer and its constituent units are not limited by the manufacturing method.

[0162] Examples of aromatic vinyl compounds corresponding to the repeating unit [I] include styrene; styrene compounds having alkyl groups with 1 to 6 carbon atoms as substituents, such as α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-t-butylstyrene, and 5-t-butyl-2-methylstyrene; styrene compounds having halogen atoms as substituents, such as 4-chlorostyrene, dichlorostyrene, and 4-monofluorostyrene; styrene compounds having alkoxy groups with 1 to 6 carbon atoms as substituents, such as 4-methoxystyrene; styrene compounds having aryl groups as substituents, such as 4-phenylstyrene; vinylnaphthalene compounds such as 1-vinylnaphthalene and 2-vinylnaphthalene; and the like. These may be used individually or in combination of two or more. Among these, aromatic vinyl compounds that do not contain polar groups, such as styrene and styrene compounds having alkyl groups with 1 to 6 carbon atoms as substituents, are preferred because they can reduce hygroscopicity, and styrene is particularly preferred due to its ease of industrial availability.

[0163] The polymer containing repeating units [I] derived from aromatic vinyl compounds is preferably a specific block copolymer [D]. Block copolymer [D] is a block copolymer comprising polymer block [A] and polymer block [B] or polymer block [C]. Polymer block [A] is a polymer block mainly composed of repeating units [I] derived from aromatic vinyl compounds. Polymer block [B] is a polymer block mainly composed of repeating units [I] derived from aromatic vinyl compounds and repeating units [II] derived from chain-like conjugated diene compounds. Polymer block [C] is a polymer block mainly composed of repeating units [II] derived from chain-like conjugated diene compounds. Here, "main component" refers to a component that accounts for 50% by weight or more in the polymer block. The proportion of the main component in the polymer block is preferably 80% by weight or more, more preferably 90% by weight or more, and even more preferably 100% by weight. "Repeating units derived from chain-like conjugated diene compounds" means repeating units having a structure obtained by polymerizing chain-like conjugated diene compounds.

[0164] Examples of chain-like conjugated diene compounds corresponding to the repeating unit [II] include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene. A single chain-like conjugated diene compound may be used, or two or more may be used in combination. The chain-like conjugated diene compound may be linear or branched.

[0165] The hydrides of vinyl aromatic hydrocarbon polymers are hydrides of polymers containing repeating units [I] derived from aromatic vinyl compounds. A specific hydrogenated block copolymer [E] is preferred as the hydride of the polymer containing repeating units [I] derived from aromatic vinyl compounds. The hydrogenated block copolymer [E] is a hydride obtained by hydrogenating the aforementioned block copolymer [D].

[0166] Hydrogenated vinyl aromatic hydrocarbon polymers are substances obtained by hydrogenating the unsaturated bonds of vinyl aromatic hydrocarbon polymers. Here, the unsaturated bonds of the vinyl aromatic hydrocarbon polymer to be hydrogenated include both the carbon-carbon unsaturated bonds of the polymer's main chain and side chains, as well as the carbon-carbon unsaturated bonds of the aromatic ring.

[0167] Hydrides can be produced, for example, by hydrogenating 90% or more of the unsaturated bonds of a vinyl aromatic hydrocarbon polymer in a solution of the polymer in the presence of a hydrogenation catalyst containing a transition metal such as nickel or palladium.

[0168] Further examples of polymers that can be used as cyclic olefin polymers include polymers containing silicon atom-containing polar groups. Examples of such polymers include modified products of the hydrides of the vinyl aromatic hydrocarbon polymers mentioned above, which are modified by silicon atom-containing polar groups. By using polymers containing silicon atom-containing polar groups as cyclic olefin polymers, the adhesion between the quantum dot molded body and other components (e.g., substrates) can be improved.

[0169] Hereinafter, the polymer used in the reaction to obtain the modified product may be appropriately referred to as the "pre-reaction polymer." The modified product may have a structure obtained, for example, by the reaction of the pre-reaction polymer with a compound having a silicon atom-containing polar group as a monomer. The reaction may be, for example, a graft polymerization reaction. However, the modified product is not limited by its manufacturing method. An alkoxysilyl group is preferred as the silicon atom-containing polar group.

[0170] Examples of compounds having a silicon atom-containing polar group include compounds having an alkoxysilyl group. Examples of compounds having an alkoxysilyl group include vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, and 2-norbornene-5-yltrimethoxysilane, which are ethylenically unsaturated silane compounds having an alkoxysilyl group.

[0171] By reacting a polymer before the reaction with a compound having a silicon atom-containing polar group, a silicon atom-containing polar group can be introduced into the polymer before the reaction, thereby obtaining a modified product having a silicon atom-containing polar group. When introducing an alkoxysilyl group as the silicon atom-containing polar group, the amount of alkoxysilyl group introduced is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, even more preferably 0.3 parts by weight or more, preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and even more preferably 3 parts by weight or less, per 100 parts by weight of the polymer before the reaction. When the amount of alkoxysilyl group introduced falls within the above range, it is possible to suppress the excessively high degree of crosslinking between alkoxysilyl groups that have been decomposed by moisture, thereby maintaining high adhesion. Examples of substances having alkoxysilyl groups used for introducing alkoxysilyl groups and modification methods are described in International Publication No. 2015 / 099079.

[0172] The amount of silicon atom-containing polar group introduced is １ It can be measured using H-NMR spectroscopy. Furthermore, when measuring the amount of silicon atom-containing polar groups introduced, if the amount is small, the number of integration steps can be increased.

[0173] Introducing an alkoxysilyl group as a silicon atom-containing polar group into a polymer before reaction is called silane modification. In silane modification, the alkoxysilyl group may be directly bonded to the polymer before reaction, or it may be bonded via a divalent organic group such as an alkylene group. Hereinafter, the polymer obtained by silane modification of the polymer before reaction will also be called a "silane-modified polymer."

[0174] As the silane-modified polymer, one or more polymers selected from silane-modified styrene-butadiene block copolymers, silane-modified styrene-butadiene-styrene block copolymers, silane-modified styrene-isoprene block copolymers, and silane-modified styrene-isoprene-styrene block copolymers are preferred.

[0175] The amount of cyclic olefin polymer relative to 100% by weight of the total polymer is preferably 50% by weight or more, more preferably 70% by weight or more, even more preferably 90% by weight or more, and usually 100% by weight or less.

[0176] (Meth)acrylic polymers refer to polymers containing repeating units derived from (meth)acrylic monomers. Repeating units derived from (meth)acrylic monomers mean repeating units having a structure obtained by polymerizing (meth)acrylic acid or (meth)acrylic acid derivatives. However, the polymer and its constituent units are not limited by their manufacturing method.

[0177] Examples of (meth)acrylic acid derivatives include (meth)acrylic acid esters, (meth)acrylamide, and (meth)acrylonitrile. Among these, acrylic acid esters and methacrylic acid esters are preferred. Specific examples of acrylic acid esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, sec-butyl acrylate, t-butyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, n-decyl acrylate, and n-dodecyl acrylate. Specific examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, n-decyl methacrylate, and n-dodecyl methacrylate. Furthermore, the (meth)acrylic acid ester may have substituents such as hydroxyl groups and halogen atoms, to the extent that it does not significantly impair the effects of the present invention. In addition, the (meth)acrylic polymer may be a homopolymer or a copolymer. Among these (meth)acrylic polymers, polymethacrylate is preferred, and polymethyl methacrylate is more preferred.

[0178] The weight-average molecular weight Mw of the polymer is preferably 10,000 or more, more preferably 15,000 or more, even more preferably 20,000 or more, preferably 100,000 or less, more preferably 80,000 or less, and even more preferably 50,000 or less. Therefore, the weight-average molecular weight Mw of the cyclic olefin polymer and the (meth)acrylic polymer may be within the above range. When the weight-average molecular weight is within this range, a high degree of balance is achieved between mechanical strength and moldability.

[0179] The molecular weight distribution (Mw / Mn) of the polymer is preferably 1.2 or higher, more preferably 1.5 or higher, even more preferably 1.8 or higher, preferably 3.5 or lower, more preferably 3.0 or lower, and even more preferably 2.7 or lower. Therefore, the molecular weight distribution (Mw / Mn) of the cyclic olefin polymer and the (meth)acrylic polymer may be within the above range. Here, Mn represents the number-average molecular weight. When the molecular weight distribution is above the lower limit of the above range, the productivity of the polymer can be increased and manufacturing costs can be suppressed. Also, when it is below the upper limit, the amount of low molecular weight components is reduced, which suppresses relaxation of the quantum dot molded body when exposed to high temperatures and improves its stability.

[0180] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) mentioned above can be measured using gel permeation chromatography (GPC). Examples of solvents used in GPC include cyclohexane, toluene, and tetrahydrofuran. When using GPC, the weight-average molecular weight is measured as a relative molecular weight, for example, in terms of polyisoprene or polystyrene.

[0181] The amount of polymer is preferably 85% by weight or more, more preferably 90% by weight or more, even more preferably 95% by weight or more, and particularly preferably 99% by weight or more, based on 100% by weight of the quantum dot molded body.

[0182] The quantum dot molded body may contain any additional components in combination with the quantum dot composite and polymer. Examples of optional components include ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and benzophenone-based ultraviolet absorbers; and light diffusing agents such as organic fine particles (polymer fine particles, etc.) and inorganic fine particles (silica particles, etc.).

[0183] Quantum dot molded bodies typically contain no solvent, or if they do, the amount of solvent is unavoidable due to the manufacturing process. For example, the amount of solvent contained in a quantum dot molded body is preferably 1 part by weight or less, and more preferably 0.5 parts by weight or less, per 100 parts by weight of the quantum dot molded body.

[0184] There are no restrictions on the form of the quantum dot molded body, and it can take various forms depending on its application. A film form is preferred for such a quantum dot molded body.

[0185] When the quantum dot molded material is a film, its thickness is appropriately selected according to the application and is not particularly limited, but for example, it is between 10 μm and 1000 μm.

[0186] The film may comprise, for example, only a layer formed of a resin material including a quantum dot composite and a polymer. Alternatively, the film may comprise, for example, the aforementioned resin material layer and any other layer formed of a material other than the resin material. Specifically, the film may comprise a substrate as a support and the aforementioned resin material layer formed on this substrate. Examples of substrate materials include resin and glass. Other examples of arbitrary layers include barrier layers and light scattering layers.

[0187] Another example of the form of a quantum dot molded body is a cap material for devices such as light-emitting diodes.

[0188] The quantum dot composite contained in the quantum dot molded body has luminescence capability, as described above. This quantum dot composite also has excellent photostability, as described above. Therefore, the quantum dot molded body can reduce the degree of decrease in the luminescence quantum yield (PLQY) of the quantum dot composite due to illumination with light. Particularly preferably, for example, 100 mW / cm². ２ It can exhibit excellent stability against high-intensity light.

[0189] The degree of decrease in the aforementioned quantum luminescence yield (PLQY) can be evaluated, for example, by a photoresistance test. Specifically, first, excitation light is irradiated onto a quantum dot molded body, and the luminescence intensity "PLQY" of the light emitted from the quantum dot molded body is evaluated. ｂｅｆ The following is measured: Then, the quantum dot molded body is irradiated with light of a wavelength of 450 nm at an intensity of 100 mW / cm². ２ A light endurance test will be conducted by irradiating the quantum dot molded body with excitation light for 5 hours. After that, under the same conditions as the measurement before the light endurance test, the emission intensity of the light emitted from the quantum dot molded body, "PL ａｆｔ The luminescence intensity PL before the light durability test is measured. ｂｅｆ and the luminescence intensity PL after the light durability test ａｆｔ Using the above formula (M1), the maintenance rate of luminescence intensity ΔPL is calculated. The maintenance rate of luminescence intensity ΔPL of the quantum dot molded body is preferably 0.6 or higher, more preferably 0.7 or higher, and even more preferably 0.8 or higher.

[0190] There are no particular limitations on the method for manufacturing a quantum dot molded body. For example, a quantum dot molded body may be manufactured by a method that includes preparing a resin material containing a quantum dot composite and a polymer, and molding this resin material using a mold. From the viewpoint of smooth manufacturing of quantum dot molded bodies, it is preferable to manufacture a quantum dot molded body by a method that includes the steps of: preparing a liquid composition containing a quantum dot composite, a polymer, and a solvent; molding this liquid composition; and drying the molded liquid composition.

[0191] Liquid compositions can be prepared by mixing quantum dot composites, polymers, and solvents. Typically, organic solvents are used as solvents. The same organic solvent contained in the quantum dot composite dispersion may be used. Furthermore, one type of solvent may be used alone, or two or more types may be used in combination. The quantum dot composites, polymers, and solvents may be mixed simultaneously or sequentially. For example, a liquid composition may be obtained by mixing a quantum dot composite dispersion containing the quantum dot composite and organic solvent with a polymer. Alternatively, a polymer solution may be prepared by mixing the polymer and organic solvent, and this polymer solution may be mixed with the quantum dot composite dispersion to obtain the liquid composition. The resulting liquid composition may be used as an ink.

[0192] After preparing the liquid composition, the liquid composition is molded. For example, the liquid composition is molded into layers having a desired planar shape. The term "planar shape" refers to the shape as viewed from the thickness direction. Examples of molding methods include coating the liquid composition, filling a mold with the liquid composition and molding it, etc. Among these, the coating method is preferred. Therefore, the step of molding the liquid composition preferably includes coating the liquid composition. The coating method for the liquid composition is preferably selected from the group consisting of die coater method, gravure coater method, comma coater method, knife coater method, and inkjet method.

[0193] After molding a liquid composition, a quantum dot molded body can be obtained by drying the molded liquid composition, which is made of a resin material containing quantum dot composites and polymers. Examples of drying methods include natural drying, heat drying, reduced-pressure drying, and reduced-pressure heat drying.

[0194] Furthermore, if the quantum dot molded body is used as a cap material for an element, the quantum dot molded body may be manufactured by dispensing a liquid composition and drying it.

[0195] Quantum dot molded bodies can exhibit light conversion and photoelectric conversion functions by containing quantum dot composites. Therefore, quantum dot molded bodies may be used, for example, as light conversion elements in light-emitting devices, power generation elements in power-generating devices, and light conversion elements in display devices.

[0196] <Light-emitting device> A light-emitting device according to one embodiment of the present invention comprises the quantum dot molded body described above. This light-emitting device typically comprises a light conversion element, and this light conversion element includes the quantum dot molded body. By using the quantum dot molded body as a light conversion element, a light-emitting device can be obtained in which the decrease in the quantum luminescence quantum yield (PLQY) of the quantum dots in the quantum dot molded body due to light is suppressed. The light-emitting device thus obtained typically has excellent luminescence efficiency.

[0197] A light-emitting device typically comprises a light source and a light conversion element, where a portion of the light from the light source passes through the light conversion element, resulting in wavelength conversion.

[0198] As the light source, one that can emit light of a wavelength that can be used as excitation light for quantum dots is used. Examples of light sources include light-emitting diodes (LEDs) and lasers. Among these, LEDs are preferred, and blue light-emitting diodes (blue LEDs) and ultraviolet light-emitting diodes (ultraviolet LEDs) are more preferred.

[0199] For example, when using a blue light-emitting diode as a light source, it is preferable that the quantum dots in the quantum dot composite include quantum dots that emit red fluorescence and quantum dots that emit green fluorescence. By converting a portion of the blue light from the blue light-emitting diode into red and green light, a light-emitting device that emits white light can be obtained.

[0200] <Power Generation Device> A power generation device according to one embodiment of the present invention comprises the quantum dot molded body described above. This power generation device comprises a power generation element, and this power generation element includes the quantum dot molded body. By using the quantum dot molded body as a power generation element, a power generation device can be obtained in which the decrease in the luminescence quantum yield (PLQY) of quantum dots in the quantum dot molded body due to light is suppressed.

[0201] The power generation device utilizes the semiconductor function of quantum dots having a perovskite crystal structure, and is also called a perovskite solar cell. The power generation element is also called the active layer.

[0202] A power generation device typically comprises a first electrode, an electron transport layer, an active layer as a power generation element, a hole transport layer, and a second electrode in this order. When light is irradiated onto the active layer, electrons flow to the first electrode and holes flow to the second electrode, generating an electromotive force. In such a power generation device, a quantum dot molded material is usually used as the active layer. The first electrode, electron transport layer, hole transport layer, and second electrode used in the power generation device may be the same as those used in known power generation devices.

[0203] <Display Element> A display element according to one embodiment of the present invention comprises the quantum dot molded body described above. This display element includes a light conversion element, and this light conversion element includes the quantum dot molded body. By using the quantum dot molded body as a light conversion element, the decrease in the luminescence quantum yield (PLQY) of the quantum dots in the quantum dot molded body due to light is suppressed, so that a display element with excellent light resistance can be obtained.

[0204] A display unit typically comprises a light source, a display panel, and a light conversion element. If the display panel is a self-emissive display panel, the display panel may also serve as the light source. Examples of display panels include liquid crystal panels as display elements for liquid crystal display devices, and organic electroluminescent (EL) panels as display elements for organic electroluminescent (OLED) display devices (hereinafter sometimes referred to as "organic EL display devices").

[0205] A liquid crystal panel typically comprises a liquid crystal cell, which includes liquid crystal and electrodes to which a voltage can be applied. The liquid crystal cell can be in any mode, such as in-plane switching (IPS) mode, vertical alignment (VA) mode, multi-domain vertical alignment (MVA) mode, continuous spinwheel alignment (CPA) mode, hybrid alignment nematic (HAN) mode, twisted nematic (TN) mode, super-twisted nematic (STN) mode, or optically compensated bend (OCB) mode. When the display panel is a liquid crystal panel, it typically includes a separate light source, comprising the light source, a quantum dot molded body as a light conversion element, and the liquid crystal panel in that order.

[0206] An organic EL panel typically comprises an organic EL element having a transparent electrode layer, an emissive layer, and an electrode layer in that order. In this organic EL element, the emissive layer can emit light when a voltage is applied from the transparent electrode layer and the electrode layer. Examples of materials constituting the organic emissive layer include poly(p-phenylenevinylene), polyfluorene, and polyvinylcarbazole materials. The emissive layer may also have a laminate of multiple layers with different emission colors, or a mixed layer in which a layer of one dye is doped with a different dye. Furthermore, the organic EL element may include functional layers such as a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, an equipotential surface forming layer, and a charge generation layer. When the display panel is an organic EL panel, the quantum dot molded body as a light conversion element may be placed on the viewing side of the organic EL panel.

[0207] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the examples shown below, and can be implemented with modifications as appropriate without departing from the scope of the claims and their equivalents.

[0208] In the following explanation, "%" and "parts" refer to weight unless otherwise specified. Furthermore, the operations described below were performed in ambient air at normal temperature and pressure (23°C, 1 atm) unless otherwise specified.

[0209] <I. Evaluation of Lightfastness of Light-Emitting Films> <Example 1> (1) Production of crude nanoparticles containing quantum dots (Step (I)): 75 mg (0.6 mmol) of formamidine hydrobromide (FABr, manufactured by Tokyo Chemical Industry Co., Ltd.), and lead(II) bromide (PbBr) ２ A precursor solution was prepared by dissolving 220.2 mg (0.6 mmol) of (manufactured by Tokyo Chemical Industry Co., Ltd.) in 1 mL of N,N-dimethylformamide (DMF, also manufactured by Tokyo Chemical Industry Co., Ltd.).

[0210] A nonpolar solution was prepared by dissolving 630 μL (1.98 μmol) of oleic acid (OA, manufactured by Tokyo Chemical Industry Co., Ltd.) and 39 μL (0.235 μmol) of octylamine (OcAm, manufactured by Tokyo Chemical Industry Co., Ltd.), which are optional organic ligands, in 15 mL of propylene glycol 1-monomethyl ether 2-acetate (PGM-Ac, liquid dielectric constant 8.03 μS / cm, manufactured by Tokyo Chemical Industry Co., Ltd.) as a nonpolar solution.

[0211] The entire volume of the obtained nonpolar solution was placed in a screw tube. While stirring the nonpolar solvent at room temperature under atmospheric pressure, 900 μL of the precursor solution was injected and mixed for 3 minutes to obtain a suspension. The obtained suspension was FAPbBr ３ The solution contained quantum dots (0.54 mmol) and oleic acid and octylamine as optional organic ligands coordinated to the quantum dots. The resulting suspension was divided into 12 equal parts and placed into 12 centrifuge tubes. The amount of suspension per centrifuge tube was 1.38 mL (amount of quantum dots: 0.045 mmol).

[0212] 1.38 mL of the suspension was placed in a centrifuge tube, 650 μL of dimethyl carbonate (DMC, manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the mixture was centrifuged for 3 minutes at 16,500 rpm (18,360 G) using a benchtop centrifuge (AS ONE Corporation "AS165W"). The supernatant was then removed to obtain crude nanoparticles. These crude nanoparticles were used in FAPbBr ３ The particles consisted of a quantum dot (0.045 mmol) and oleic acid and octylamine as arbitrary organic ligands coordinated to the quantum dot.

[0213] (2) Preparation of a luminescent nanoparticle dispersion containing a quantum dot composite (Step (II)): 97.9 mg (0.25 mmol) of hexadecyldimethyl(3-sulfopropyl)ammonium hydroxide intramolecular salt (SB3-16, manufactured by Tokyo Chemical Industry Co., Ltd., compound represented by formula (b2)) as a second ligand was added to 1 mL of propylene carbonate (PPC, liquid dielectric constant 64 μS / cm, manufactured by Tokyo Chemical Industry Co., Ltd.), and the mixture was heated and dissolved to obtain a second ligand solution.

[0214] Crude nanoparticles (quantum dot amount: 0.045 mmol) were dispersed in 1.0 mL of toluene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a redispersion medium to prepare a crude nanoparticle dispersion. The entire volume of the obtained crude nanoparticle dispersion was placed in a screw-cap tube, and 60 μL of the second ligand solution was added while stirring at room temperature under atmospheric pressure to prepare a suspension. This suspension contained intermediate nanoparticles containing quantum dots (0.045 mmol) and a second ligand (0.015 mmol) coordinated to the quantum dots. 1.0 mL of this suspension and 1.0 mL of PPC were placed in a centrifuge tube and centrifuged at 16500 rpm (18360 G) for 2 minutes using a benchtop centrifuge (AS ONE "AS165W"). The supernatant was then removed to obtain intermediate nanoparticles.

[0215] A pre-dispersion was prepared by dispersing intermediate nanoparticles in 1.0 mL of toluene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a redispersion medium. The obtained pre-dispersion was centrifuged at 16,500 rpm for 3 minutes. The supernatant containing the intermediate nanoparticles was collected from the pre-dispersion after centrifugation.

[0216] The suspension in 12 centrifuge tubes was subjected to the above-described centrifugation to form crude nanoparticles, form intermediate nanoparticles, and collect the supernatant containing the intermediate nanoparticles, yielding 12 mL of supernatant containing intermediate nanoparticles. This 12 mL of supernatant contained intermediate nanoparticles, each containing a quantum dot (0.54 mmol) and a second ligand (0.18 mmol) coordinated to the quantum dot. The 12 mL of supernatant containing intermediate nanoparticles was placed in a screw-cap tube.

[0217] 392.5 mg (0.5 mmol) of lecithin (manufactured by Fujifilm Wako Pure Chemical Industries; compound represented by formula (a1)) was dissolved in 1 mL of toluene to obtain a first ligand solution. 240 μL of this first ligand solution was added to a screw tube containing a supernatant liquid with intermediate nanoparticles to obtain a luminescent nanoparticle dispersion containing luminescent nanoparticles as a quantum dot complex. The luminescent nanoparticle dispersion contained luminescent nanoparticles as a quantum dot complex, comprising a quantum dot (0.54 mmol), a first ligand (0.12 mmol) coordinated to the quantum dot, and a second ligand (0.18 mmol) coordinated to the quantum dot, in 12.24 mL.

[0218] An integrating sphere was set in a fluorescence spectrophotometer (FP-8600, manufactured by JASCO Corporation; excitation wavelength 370 nm). The luminescent nanoparticle dispersion was diluted with spectroscopic toluene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to obtain a sample dispersion with a sample absorption rate of 0.50. The sample absorption rate represents the ratio of light absorbed by the sample dispersion at the excitation wavelength. The emission quantum yield (PLQY) of the sample dispersion was measured using the aforementioned fluorescence spectrophotometer. The emission quantum yield (PLQY) was 92%.

[0219] Furthermore, the average particle size of the luminescent nanoparticles contained in the luminescent nanoparticle dispersion is determined by the maximum wavelength of photoluminescence (λ) measured by a fluorescence spectrophotometer. ＰＬ The measurement was taken from [location]. The average particle size of the luminescent nanoparticles was 12 nm.

[0220] (3) Manufacturing of luminescent film (Process (III)): 43.5 g (50 mL) of toluene and 28.9 g (40% by weight) of cyclic olefin polymer (COP, "ZEONOR" manufactured by Nippon Zeon Co., Ltd.) were placed in a 100 mL screw tube and mixed at 600 rpm for 24 hours using a rotating stand. The resin solution was obtained by visually confirming that the cyclic olefin polymer was completely dissolved.

[0221] Toluene was added to the luminescent nanoparticle dispersion obtained in step (II) described above to adjust the amount of quantum dots in the luminescent nanoparticle dispersion to 8.0 mg / mL.

[0222] 7 g of resin solution (containing 2.8 g of polymer) and 1.7 mL of luminescent nanoparticle dispersion (containing 13.6 mg of quantum dots in the luminescent nanoparticles) were placed in a 50 mL screw-cap bottle. Mixing was performed for 20 minutes and degassing for 30 seconds using a mixing device (Thinky Co., Ltd. "Awatori Rentaro AR-100") to obtain a liquid composition. The obtained liquid composition was irradiated with ultraviolet light using a handy UV lamp (AS ONE Corporation, ultraviolet wavelength 365 nm). After confirming that the liquid composition emitted light uniformly, a luminescent resin ink was obtained as the liquid composition.

[0223] A luminescent resin ink was uniformly applied onto a base film at a coating speed of 50 mm / sec using a multi-film applicator (BEVS "1806F / 150") and an auto film applicator (Tester Sangyo Co., Ltd.) with a gap set to 560 μm. A layer of luminescent resin ink was formed by the application. This formed layer of luminescent resin ink was dried on the auto film applicator at room temperature for 30 minutes, and the base film was peeled off to obtain a luminescent film as a molded body. The thickness of the luminescent film was measured with a digital thickness gauge (TECLOCK "PG02A"), and the film thickness was found to be 100 μm.

[0224] (4) Photostability evaluation test: Using a fluorescence spectrophotometer (FP-8600 manufactured by JASCO Corporation; excitation wavelength 450 nm), the luminescence intensity "PL" of the light-emitting film before the photostability test was performed. ｂｅｆ We measured ".

[0225] A light durability test was conducted on the light-emitting film by irradiating it with light. The method of this light durability test is as follows: The light-emitting film was placed on an electronic cooling device. The temperature of the contact surface of the electronic cooling device that contacts the light-emitting film was set to 25°C. An LED area irradiator (manufactured by CCS Corporation, wavelength 450 nm) was set up perpendicular to the contact surface at an irradiation distance of 100 mm. The LED area irradiator was set so that its light-emitting surface was parallel to the contact surface of the electronic cooling device. The output of this LED area irradiator was set so that the irradiation intensity to the light-emitting film was 100 mW / cm². ２ The settings were adjusted, and a light durability test was conducted by irradiating the light-emitting film with light for 5 hours.

[0226] After conducting the light durability test, the emission intensity PL before the light durability test was measured using the aforementioned fluorescence spectrophotometer. ｂｅｆ Under the same conditions as the measurement method, the luminescence intensity "PL" after conducting the light durability test was measured. ａｆｔ The following was measured: luminous intensity PL before the light durability test. ｂｅｆ and the luminescence intensity PL after the light durability test ａｆｔ The luminescence intensity retention rate "ΔPL" was calculated using the following formula (M1). A higher retention rate ΔPL indicates superior light stability. As a result, the luminescence intensity retention rate ΔPL of the luminescent film that underwent 5 hours of light irradiation in the light durability test was 0.82. ΔPL = PL ａｆｔ / PL ｂｅｆ (M1)

[0227] (5) Evaluation of changes over time due to light irradiation: The light-emitting film was irradiated with light under the same conditions as the light durability test described above. The luminescence intensity was measured at 1 hour, 3 hours, 4 hours, and 5 hours after the start of light irradiation (light irradiation time), and the maintenance ratio ΔPL at those times was calculated. From these results, the change in the luminescence intensity of the light-emitting film over time was evaluated. The results are shown in Figure 1 and Table 5.

[0228] <Example 2> 2.00 g (12 mmol) of 4-bromobutyric acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 2.02 g (6 mmol) of N,N-dimethylhexadecylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a three-necked flask. 20 mL of acetonitrile was added, and the mixture was stirred at 75°C for 30 hours under a nitrogen atmosphere. The heating of the solution was then stopped, 20 mL of diethyl ether was added, and the mixture was stirred until the reaction solution reached room temperature. The solid precipitated in the reaction solution was filtered and washed with ethyl acetate to obtain the intramolecular salt of hexadecyldimethyl(3-carboxypropyl)ammonium hydroxide (CB3-16, a compound represented by formula (b5)).

[0229] Except for changing the second ligand used in the preparation of the second ligand solution from SB3-16 to 88.8 mg (0.25 mmol) of CB3-16, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 86%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.87.

[0230] <Example 3> Except for changing the amount of the first ligand solution added to 480 μL, the same method as in Example 1 was used to manufacture and evaluate a luminescent nanoparticle dispersion, a luminescent resin ink, and a luminescent film. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 91%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.84.

[0231] <Example 4> Except for changing the amount of the first ligand solution added to 960 μL, the same method as in Example 1 was used to manufacture and evaluate a luminescent nanoparticle dispersion, a luminescent resin ink, and a luminescent film. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 91%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.81.

[0232] <Example 5> 18.89 g (47.6 mmol) of sodium 2-chloroethanesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 15.9 mL (47.2 mmol) of N,N-dimethylhexadecylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a three-necked flask. 75 mL of DMF was added to the flask and the mixture was stirred at 70°C for 24 hours under a nitrogen atmosphere. The heating of the solution was then stopped, 20 mL of diethyl ether was added, and the mixture was stirred until the reaction solution reached room temperature. The solid precipitated in the reaction solution was filtered and washed with ethyl acetate to obtain the intramolecular salt of hexadecyldimethyl(3-sulfoethyl)ammonium hydroxide (SB2-16, a compound represented by formula (b1)).

[0233] The luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1, except that the second ligand used in the preparation of the second ligand solution was changed from SB3-16 to 94.3 mg (0.25 mmol) of SB2-16. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 99%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.93. Furthermore, the change over time due to light irradiation was evaluated using the same method as in Example 1. The results are shown in Figure 1 and Table 5.

[0234] <Example 6> 3.73 g (32 mmol) of sodium chloroacetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 15.9 mL (47.2 mmol) of N-dimethylhexadecylamine (manufactured by Tokyo Chemical Industries, Ltd.) were placed in a three-necked flask. 50 mL of pure water was added to the flask and the mixture was stirred at 80°C for 5 hours under a nitrogen atmosphere. The heating of the solution was then stopped, 30 mL of ethyl acetate was added, and the mixture was stirred until the reaction solution reached room temperature. The solid precipitated in the reaction solution was filtered and washed with ethyl acetate to obtain the intramolecular salt of hexadecyldimethyl(3-carboxymethyl)ammonium hydroxide (CB1-16, a compound represented by formula (b4)).

[0235] The luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1, except that the second ligand used in the preparation of the second ligand solution was changed from SB3-16 to 89.1 mg (0.25 mmol) of CB1-16. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 91%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.79.

[0236] <Example 7> 1.36 g (10 mmol) of 1,4-butanesultone (manufactured by Tokyo Chemical Industry Co., Ltd.) and 2.02 mL (6 mmol) of N-dimethylhexadecylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a three-necked flask. 20 mL of acetonitrile was added, and the mixture was stirred at 70°C for 24 hours under a nitrogen atmosphere. The heating of the solution was then stopped, 20 mL of diethyl ether was added, and stirring was continued until the reaction solution reached room temperature. The solid precipitated in the reaction solution was filtered and washed with ethyl acetate to obtain the intramolecular salt of hexadecyldimethyl(3-sulfobutyl)ammonium hydroxide (SB4-16, a compound represented by formula (b3)).

[0237] Except for changing the second ligand used in the preparation of the second ligand solution from SB3-16 to 109.3 mg (0.25 mmol) of SB4-16, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 91%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the phototillage test was 0.85.

[0238] <Example 8> Except for changing the second ligand used in the preparation of the second ligand solution from SB3-16 to 6.27 mg (0.016 mmol) of SB4-16, the same method as in Example 1 was used to manufacture and evaluate a luminescent nanoparticle dispersion, a luminescent resin ink, and a luminescent film. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 89%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.79.

[0239] <Example 9> Except for changing the amount of luminescent nanoparticle dispersion used in the production of the luminescent film from 1.7 mL to 2.5 mL, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 89%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.82.

[0240] <Example 10> Except that the amount of formamidine hydrobromide (FABr) used in the production of crude nanoparticles was changed to methylammonium bromide (MABr, manufactured by Tokyo Chemical Industry Co., Ltd.) at a dose of 67.2 mg (0.6 mmol), the same method as in Example 1 was used to produce a luminescent nanoparticle dispersion, a luminescent resin ink, and a luminescent film. The quantum dots produced in Example 10 were MAPbBr ３ The material consisted of the following. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 94%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.80.

[0241] <Example 11> Except for changing the type of polymer used in the production of the luminescent film from a cyclic olefin polymer to polymethyl methacrylate (PMMA, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), the same method as in Example 1 was used to produce and evaluate a luminescent nanoparticle dispersion, a luminescent resin ink, and a luminescent film. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 94%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.84.

[0242] <Example 12> The second ligand used in the preparation of the second ligand solution was changed from SB3-16 to 88.8 mg (0.25 mmol) of CB3-16. In addition, the type of polymer used in the production of the luminescent film was changed from a cyclic olefin polymer to polymethyl methacrylate (PMMA, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). Except for the above, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 94%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.79.

[0243] <Comparative Example 1> The second ligand was not added when preparing the second ligand solution. Also, the first ligand was not added when preparing the first ligand solution. Except for the above, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. Therefore, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film manufactured in Comparative Example 1 contained FAPbBr instead of quantum dot composite. ３ The solution contained crude nanoparticles comprising quantum dots and oleic acid and octylamine as arbitrary organic ligands coordinated to the quantum dots. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 100%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.32. Furthermore, the change over time due to light irradiation was evaluated using the same method as in Example 1. The results are shown in Figure 1 and Table 5.

[0244] <Comparative Example 2> Except for the absence of the second ligand in the preparation of the second ligand solution, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 99%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.50. Furthermore, the change over time due to light irradiation was evaluated using the same method as in Example 1. The results are shown in Figure 1 and Table 5.

[0245] <Comparative Example 3> The second ligand was not added when preparing the second ligand solution. Also, the amount of the first ligand solution used to prepare the luminescent nanoparticle dispersion was changed to 384 μL. Except for the above, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 91%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.58.

[0246] <Comparative Example 4> A luminescent nanoparticle dispersion, a luminescent resin ink, and a luminescent film were manufactured and evaluated using the same method as in Example 1, except that the first ligand was not added when preparing the first ligand solution. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 96%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.17.

[0247] <Comparative Example 5> The amount of SB3-16 used as the second ligand in the preparation of the second ligand solution was changed to 195.8 mg (0.5 mmol). Also, the first ligand was not added when preparing the first ligand solution. Except for the above, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 100%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.38. Furthermore, the change over time due to light irradiation was evaluated using the same method as in Example 1. The results are shown in Figure 1 and Table 5.

[0248] <Comparative Example 6> The second ligand used in the preparation of the second ligand solution was changed from SB3-16 to 88.8 mg (0.25 mmol) of CB3-16. Also, the first ligand was not added when preparing the first ligand solution. Except for the above, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 94%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.32.

[0249] <Comparative Example 7> The second ligand used in the preparation of the second ligand solution was changed from SB3-16 to 192.7 mg (0.5 mmol) of CB3-16. Also, the first ligand was not added when preparing the first ligand solution. Except for the above, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 84%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.16.

[0250] <Comparative Example 8> The second ligand used in the preparation of the second ligand solution was changed from SB3-16 alone to a combination of 195.8 mg (0.5 mmol) of SB3-16 and 192.7 mg (0.5 mmol) of CB3-16. In addition, the first ligand was not added when preparing the first ligand solution. Except for the above, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 93%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.18.

[0251] <Comparative Example 9> The second ligand was not added when preparing the second ligand solution. Also, the first ligand was not added when preparing the first ligand solution. Furthermore, the type of polymer used in the production of the luminescent film was changed from a cyclic olefin polymer to polymethyl methacrylate (PMMA). Except for the above, the luminescent nanoparticle dispersion, luminescent resin ink, and luminescent film were manufactured and evaluated using the same method as in Example 1. The luminescence quantum yield (PLQY) measured using the luminescent nanoparticle dispersion was 95%. In addition, the luminescence intensity retention rate ΔPL of the luminescent film after 5 hours of light irradiation in the light durability test was 0.52.

[0252] <Results of Lightfastness Evaluation of Light-Emitting Films> The results of measuring the luminescence intensity retention rate ΔPL of the light-emitting films that were irradiated with light for 5 hours in the light-durability tests in Examples 1 to 12 and Comparative Examples 1 to 9 described above are shown in Tables 1 to 4 below. In the tables below, the meanings of the abbreviations are as follows: "Number of intercharge atoms" of the first ligand: Nitrogen atoms N with a positive charge ＋ And, an oxygen atom O that has a negative charge － The number of skeletal atoms connecting the first ligand and the second ligand. The "QD ratio" of the first ligand: the amount of substance of the first ligand relative to the amount of substance of the quantum dot. The "number of intercharge atoms" of the second ligand: positively charged nitrogen atoms N ＋ And, an oxygen atom O that has a negative charge － The number of skeletal atoms connecting the two ligands. "QD ratio" of the second ligand: Amount of substance of the second ligand relative to the amount of substance of the quantum dots. "Molar ratio (first ligand / second ligand)": Molar ratio of the first ligand to the second ligand (amount of substance of the first ligand relative to the amount of substance of the second ligand). "PLQY": Quantum emission yield. "QD concentration": Amount of quantum dots relative to 100% by weight of the luminescent film. "ΔPL": Maintenance rate of luminescence intensity.

[0253]

[0254]

[0255]

[0256]

[0257] As shown in Tables 1 to 4 above, in Examples 1 to 12, a higher luminescence intensity retention rate ΔPL was obtained than in Comparative Examples 1 to 9. Therefore, from these results, it was confirmed that the quantum dot composite of the present invention and the luminescent film as a molded body containing it can suppress the decrease in PLQY due to light irradiation and achieve excellent photostability.

[0258] <Evaluation Results of Changes in the Maintenance Rate of Luminous Emission Intensity of Luminous Emission Films over Time> The maintenance rates of luminous emission intensity ΔPL at 1 hour, 3 hours, 4 hours, and 5 hours of light irradiation in the light durability tests measured in Examples 1 and 5, and Comparative Examples 1, 2, and 5, are shown in Table 5 and Figure 1.

[0259]

[0260] As shown in Table 5 and Figure 1, in Comparative Examples 1, 2, and 5, the retention rate of luminescence intensity ΔPL decreased significantly over time, while in Examples 1 and 5, the decrease in the retention rate of luminescence quantum yield (PLQY) over time was small. Therefore, this result also confirms that the quantum dot composite of the present invention and the luminescent film as a molded article containing it can suppress the decrease in PLQY due to light irradiation and achieve excellent photostability.

[0261] <II. Evaluation of Lightfastness of Luminescent Nanoparticle Dispersion> <Example 13> A luminescent nanoparticle dispersion was prepared using the same method as in Example 5. A sample dispersion was prepared using the same method as the method for measuring the luminescence quantum yield (PLQY) in step (2) of Example 1, and its PLQY was measured.

[0262] Furthermore, the luminescent nanoparticle dispersion was subjected to a fluorescence spectrophotometer under the same conditions as in step (4) of Example 1 to determine the luminescence intensity "PL" before the photodurability test. ｂｅｆ The following was measured. Next, the luminescent nanoparticle dispersion was placed in a transparent container. An LED area irradiator (manufactured by CCS Corporation, wavelength 450 nm) was set up perpendicular to the surface of the luminescent nanoparticle dispersion at an irradiation distance of 100 mm. The LED area irradiator was set so that its light-emitting surface was parallel to the surface of the luminescent nanoparticle dispersion. The output of this LED area irradiator was set so that the irradiation intensity to the luminescent nanoparticle dispersion was 100 mW / cm². ２ The system was configured to perform a photoresistance test, in which the luminescent nanoparticle dispersion was irradiated with light for 5 hours.

[0263] After conducting the light durability test, the emission intensity PL before the light durability test was measured using the aforementioned fluorescence spectrophotometer. ｂｅｆ Under the same conditions as the measurement method, the luminescence intensity "PL" after conducting the light durability test was measured. ａｆｔ The following was measured: luminous intensity PL before the light durability test. ｂｅｆ and the luminescence intensity PL after the light durability test ａｆｔ Therefore, the retention rate of the luminescence intensity of the luminescent nanoparticle dispersion after the light durability test, "ΔPL", was calculated using the above formula (M1). As a result, the retention rate ΔPL was 0.94.

[0264] <Example 14> PLQY was measured and the retention rate ΔPL of the luminescence intensity of the luminescent nanoparticle dispersion after the light durability test was measured using the same method as in Example 13, except that the luminescent nanoparticle dispersion was prepared by the same method as in Example 10. As a result, the retention rate ΔPL was 0.80.

[0265] <Comparative Example 10> PLQY was measured and the retention rate ΔPL of the luminescence intensity of the luminescent nanoparticle dispersion after the light durability test was measured using the same method as in Example 13, except that the luminescent nanoparticle dispersion was prepared by the same method as in Comparative Example 1. As a result, the retention rate ΔPL was 0.56.

[0266] <Results of lightfastness evaluation of luminescent nanoparticle dispersions> The measurement results for Examples 13-14 and Comparative Example 10 described above are shown in Table 6 below. In Table 6, the "QD concentration (wt%)" of the dispersion represents the amount of quantum dots relative to 100% by weight of the luminescent nanoparticle dispersion. The amount of quantum dots in the luminescent nanoparticle dispersions in Examples 13-14 and Comparative Example 10 was 8.0 mg / L in all cases, and the calculation was performed assuming that the solvent was toluene (specific gravity: 0.87 g / mL) in all cases.

[0267]

[0268] As shown in Table 6 above, in Examples 13 and 14, a higher luminescence intensity retention rate ΔPL was obtained than in Comparative Example 10. Therefore, from these results, it was confirmed that the quantum dot composite of the present invention and the luminescent nanoparticle dispersion as a quantum dot composite dispersion containing it can suppress the decrease in PLQY due to light irradiation and achieve excellent photostability.

[0269] Tables 7 and 8 show the composition of the quantum dot composites produced in Examples 1 to 14. In Method 7 and Table 8, the meanings of the abbreviations are as follows: "QD ratio (first ligand)": Amount of substance of the first ligand relative to the amount of substance of the quantum dot "QD ratio (second ligand)": Amount of substance of the second ligand relative to the amount of substance of the quantum dot "QD ratio (total ligand)": The sum of the amounts of substance of the first ligand and the second ligand relative to the amount of substance of the quantum dot "Molar ratio (first ligand / second ligand)": Amount of substance of the first ligand relative to the amount of substance of the second ligand

[0270]

[0271]

Claims

1. A quantum dot complex comprising: a quantum dot having a perovskite-type crystal structure; a first ligand represented by the following formula (1-1); and a second ligand represented by the following formula (2-1). (In formula (1-1), R ａ１ , R ａ２ and R ａ３ each independently represent a hydrogen atom or a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms, R ａ４ represents a divalent aliphatic hydrocarbon group that may have a substituent, and X ａ represents a divalent group.) (In formula (2-1), R ｂ１ represents a monovalent aliphatic hydrocarbon group having 7 or more carbon atoms that may have a substituent, and R ｂ２ and R ｂ３ each independently represent a hydrogen atom or a monovalent aliphatic hydrocarbon group that may have a substituent, R ｂ４ represents a divalent aliphatic hydrocarbon group that may have a substituent, and X ｂ represents a divalent group.) 2. In equation (1-1), the nitrogen atom N has a positive charge. ＋ And, an oxygen atom O that has a negative charge － The quantum dot composite according to claim 1, wherein the number of skeletal atoms connecting the and is 3 or more and 6 or less.

3. In equation (1-1), R ａ４ The number of carbon atoms in the divalent aliphatic hydrocarbon group is R ａ１ , R ａ２ and R ａ３ The quantum dot composite according to claim 1, wherein the number of each carbon atom is greater than the number of carbon atoms in each dot.

4. In equation (2-1), the nitrogen atom N has a positive charge. ＋ And, an oxygen atom O that has a negative charge － The quantum dot composite according to claim 1, wherein the number of skeletal atoms connecting the and is 2 or more and 6 or less.

5. In equation (2-1), R ｂ４ The number of carbon atoms in the divalent aliphatic hydrocarbon group is R ｂ１ The quantum dot composite according to claim 1, wherein the number of carbon atoms is smaller than that of the monovalent aliphatic hydrocarbon group.

6. The quantum dot composite according to claim 1, wherein the total amount of the first ligand and the second ligand is 0.01 times or more and 5.0 times or less on a basis of amount of substance relative to the amount of quantum dots.

7. The quantum dot composite according to claim 1, wherein the amount of the first ligand is 0.2 times or more and 20.0 times or less on a molar basis relative to the amount of the second ligand.

8. The quantum dot composite according to claim 1, wherein the average particle size of the quantum dot composite is 1 nm or more and 30 nm or less.

9. A quantum dot complex dispersion comprising the quantum dot complex according to any one of claims 1 to 8 and an organic solvent.

10. A molded article comprising a quantum dot composite according to any one of claims 1 to 8 and a polymer.

11. The molded article according to claim 10, comprising 99% by weight or more of the polymer.

12. The molded article according to claim 10, wherein the polymer includes a cyclic olefin polymer.

13. The molded article according to claim 12, wherein the cyclic olefin polymer includes a norbornene polymer, and the norbornene polymer includes at least one selected from the group consisting of a hydride of a ring-opening polymer of a monomer having a norbornene structure, an addition copolymer of a monomer having a norbornene structure and an α-olefin, and its hydride.

14. The molded article according to claim 12, wherein the cyclic olefin polymer comprises a hydrogenated block copolymer [E]; and the hydrogenated block copolymer [E] comprises a hydrogenated block copolymer obtained by hydrogenating a block copolymer [D] consisting of a polymer block [A] mainly composed of repeating units [I] derived from an aromatic vinyl compound, a polymer block [B] mainly composed of repeating units [I] derived from an aromatic vinyl compound and repeating units [II] derived from a chain-like conjugated diene compound, or a polymer block [C] mainly composed of repeating units [II] derived from a chain-like conjugated diene compound.

15. The molded article according to claim 14, wherein the cyclic olefin polymer contains an alkoxysilyl group.

16. The molded article according to claim 10, wherein the amount of quantum dots per 100 parts by weight of the molded article is 0.01 parts by weight or more and 50 parts by weight or less.

17. The molded body according to claim 10, wherein the molded body is a film.

18. A light-emitting device comprising a light-converting element, wherein the light-converting element includes the molded body described in claim 10.

19. A power generation device comprising a power generation element, wherein the power generation element includes the molded body described in claim 10.

20. A display body comprising a light conversion element, wherein the light conversion element includes the molded body described in claim 10.

21. A method for producing a quantum dot composite according to claim 1, comprising the steps of: producing a quantum dot having a perovskite crystal structure; and mixing the quantum dot, the first ligand, and the second ligand.

22. A method for manufacturing a molded article according to claim 10, comprising the steps of: molding a liquid composition comprising a quantum dot composite, a polymer, and a solvent; and drying the molded liquid composition.

23. The method for manufacturing a molded article according to claim 22, wherein the step of molding the liquid composition includes applying the liquid composition, and the method of applying the liquid composition is selected from the group consisting of die coater, gravure coater, comma coater, knife coater, and inkjet method.

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