Molded body and method for manufacturing the same, as well as light-emitting device, power-generating device and display body

Abstract

To provide a molded article containing a quantum dot material having a perovskite-type crystal structure, in which the shift of the emission wavelength peak over time is suppressed. [Solution] A molded article comprising a quantum dot material having a perovskite crystal structure, an alkali metal having a smaller ionic radius than the A-site material constituting the A-site of the perovskite crystal structure of the quantum dot material, and a cyclic olefin polymer, wherein the content of the alkali metal relative to the A-site material of the quantum dot material is 0.05 mol% or more.

Description

Technical Field

[0001] The present invention relates to a molded body, a method for manufacturing the same, and a light-emitting device, a power-generation device and a display body using the molded body. [[ID = 6]] [[ID = 7]]

Background Art

[0002] [[ID = 11]] [[ID = 12]]Quantum dot materials having a perovskite crystal structure have attracted attention because they exhibit characteristics such as a high photoluminescence quantum yield and a small variation in emission wavelength distribution (Patent Documents 1 to 3). In the following description, the photoluminescence quantum yield may be referred to as "PLQY" for explanation. [[ID = 13]] [[ID = 14]]

[0003] [[ID = 15]] [[ID = 16]]For example, Patent Document 1 describes a perovskite quantum dot composite in which at least a part of the surface of the compound having a perovskite structure (ABX3) is substituted with A' having a smaller ionic radius than the A site, and an organic acid is coordinated to the A'. In Patent Document 1, the purpose is to suppress the generation of surface defects of the quantum dot material and suppress the decrease in PLQY. [[ID = 17]] [[ID = 18]]

Prior Art Documents

Patent Documents

[0004] [[ID = 25]] [[ID = 26]] [[ID = 27]]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] [[ID = 46]] When the inventors of the present invention considered mixing a quantum dot material having a perovskite crystal structure with a resin to form a molded body and applying it to a light-emitting device or the like, they found that in the molded body containing the quantum dot material, the emission wavelength peak may shift over time.

[0006] The present invention is an invention based on the above findings, and an object thereof is to provide a molded body containing a quantum dot material having a perovskite crystal structure, in which a shift in the emission wavelength peak over time is suppressed, a method for producing the same, and a light-emitting device, a power generation device, and a display using the molded body.

Means for Solving the Problems

[0007] In order to achieve the above object, the inventors of the present invention conducted research and found that by forming a molded body containing a quantum dot material having a perovskite crystal structure and an alkali metal having an ionic radius smaller than the A-site material of the quantum dot material at a predetermined ratio, and further containing a cyclic olefin polymer as a polymer, it is possible to suppress the shift of the emission wavelength peak over time, and thus the present invention was completed.

[0008] The present invention includes the following. <1> A molded body including a quantum dot material having a perovskite crystal structure, an alkali metal having an ionic radius smaller than the A-site material constituting the A-site of the perovskite crystal structure of the quantum dot material, and a cyclic olefin polymer, wherein the content of the alkali metal with respect to the A-site material of the quantum dot material is 0.05 mol% or more. <2> The molded body according to <1>, wherein the cyclic olefin polymer is a non-curing polymer. <3> The molded body according to <1> or <2>, wherein the cyclic olefin polymer includes a norbornene polymer, and the norbornene polymer includes at least one selected from 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 a hydride thereof. <4> The cyclic olefin polymer comprises a hydrogenated block copolymer [E], wherein the hydrogenated block copolymer [E] is a hydrogenated block copolymer obtained by hydrogenating a block copolymer [D] which consists 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. <1> or <2> The molded body described above. <5> The cyclic olefin polymer contains an alkoxysilyl group. <4> The molded body described above. <6> The amount of the quantum dot material relative to 100 parts by weight of the cyclic olefin polymer is 0.001 parts by weight or more and 5 parts by weight or less. <1> ~ <5> A molded article as described in any one of the items. <7> The aforementioned molded body is a film. <1> ~ <6> A molded article as described in any one of the items. <8> <1> ~ <7> A light-emitting device using a molded body described in any one of the items as a light-converting element. <9> <1> ~ <7> A power generation device that uses a molded body described in any one of the items as a power generation element. <10> <1> ~ <7> A display unit using a molded body described in any one of the items as a light conversion element. <11> <1> ~ <7> A method for manufacturing a molded article according to any one of the above, comprising: a first step of obtaining a composition comprising the quantum dot material, the alkali metal, and the cyclic olefin polymer; and a second step of forming a molded article using the composition. <12> The first step includes the steps of obtaining a dispersion containing the quantum dot material and the alkali metal, obtaining a solution of the cyclic olefin polymer, and mixing the dispersion and the solution. <11> A method for manufacturing a molded article as described above. <13> The first step includes the steps of obtaining a dispersion containing the quantum dot material and the alkali metal, and dissolving the cyclic olefin polymer in the dispersion. <11> A method for manufacturing a molded article as described above. <14> The second step includes a step of applying the composition, wherein the method of applying the composition is selected from the group consisting of die coater method, gravure coater method, comma coater method, knife coater method, and inkjet method. <11> ~ <13> A method for manufacturing a molded article as described in any one of the items. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a molded article containing a quantum dot material having a perovskite-type crystal structure, in which the shift of the emission wavelength peak over time is suppressed, a method for manufacturing the same, and a light-emitting device, a power-generating device, and a display using the molded article. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a graph showing the change in emission wavelength peak (change EW) after 1 hour, 3 hours, and 5 hours of light irradiation in the light durability tests for the light-emitting films of Examples 1-4 and Comparative Examples 1-2. [Modes for carrying out the 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 equivalents of the present invention. The components of the embodiments shown below can be combined as appropriate.

[0012] In the following explanation, the term "solvent" includes, for the sake of clarity, not only the medium in a solution but also the dispersion medium used to disperse solid matter within it.

[0013] 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 a resin film.

[0014] <1. Overview of the molded product> A molded article according to one embodiment of the present invention comprises a quantum dot material having a perovskite crystal structure, an alkali metal having a smaller ionic radius than the A-site material constituting the A-site of the perovskite crystal structure of the quantum dot material, and a cyclic olefin polymer.

[0015] In the following explanation, "quantum dot materials having a perovskite crystal structure" may be simply referred to as "quantum dot materials." Also, in the following explanation, "alkali metals having a smaller ionic radius than A-site materials" may be referred to as "alkali metals (A')."

[0016] In the molded article according to this embodiment, the content (mol%) of alkali metal (A') relative to the A-site material in the quantum dot material is greater than or equal to a predetermined value.

[0017] According to this embodiment, by including a quantum dot material and an alkali metal (A') in a predetermined ratio, and further combining these with a cyclic olefin polymer, a molded article can be obtained in which the shift of the emission wavelength peak over time is suppressed.

[0018] Furthermore, according to this embodiment, since the quantum dot material and alkali metal (A') are included in a predetermined ratio, a molded article with good PLQY can usually be obtained.

[0019] Furthermore, according to this embodiment, since the shift in the emission wavelength peak of the quantum dot material over time is suppressed, it is thought that structural changes in the quantum dot material itself are suppressed, and therefore it is possible that the degradation of the quantum dot material itself over time can be suppressed.

[0020] <2. Materials of the molded body> The molded body comprises at least a quantum dot material, an alkali metal (A'), and a cyclic olefin polymer.

[0021] <2.1. Quantum Dot Materials> The quantum dot material contained in the molded body is typically a nano-sized particulate material that emits light in the visible to near-infrared wavelength range (300 nm to 1000 nm). In other words, quantum dot material can be considered as luminescent nanoparticles.

[0022] The quantum dot material contained in the molded body has a perovskite crystal structure. A "perovskite crystal structure" is a type of crystal structure, and refers to the same crystal structure as perovskite (CaTiO3). In a perovskite crystal structure, for example, if the sites of the crystal structure are 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.

[0023] As a quantum dot material having a perovskite crystal structure (perovskite quantum dot particles), it is preferable to use a material represented by the following compositional formula (A). The material represented by the following compositional formula (A) is also called a metal halide perovskite particle. A (s+a) B (t+b) X (u+c) (A) (In the above compositional formula (A), A is a monovalent cation, B is a divalent metal ion, X is a monovalent anion, a is -0.2 ≤ a ≤ 0.2, b -0.2 ≤ b ≤ 0.2, c is -0.5 ≤ a ≤ 0.5, s is an integer between 1 and 4 (inclusive), t is 1 or 2, u is an integer between 3 and 9 (inclusive), and s + (2 × t) = u.)

[0024] In equation (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:u is represented by positive integers in one of the following ratios: 1:1:3, 4:1:6, and 2:1:4, and particularly preferably s:t:u is represented by 1:1:3.

[0025] In the composition formula (A) above, a is usually -0.2 ≤ a ≤ 0.2, preferably -0.1 ≤ a ≤ 0.1, and ideally a = 0. Also, b is usually -0.2 ≤ b ≤ 0.2, preferably -0.1 ≤ b ≤ 0.1, and ideally b = 0. Also, c is -0.5 ≤ c ≤ 0.5, preferably -0.3 ≤ c ≤ 0.3, and ideally c = 0. In this embodiment, it is preferable that in the composition formula (I) above, a = b = c = 0 and s:t:u is 1:1:3, that is, the quantum dot particle has a composition represented by ABX3.

[0026] The A-site material constituting the A-site of a quantum dot material is usually a monovalent cation, and specifically, it can be an ion from Group 1 of the periodic table (alkali metal ions) or a monovalent organic cation. When the A-site material is an alkali metal ion, examples of alkali metals include cesium (Cs), rubidium (Rb), potassium (K), and sodium (Na). When the A-site material is an organic cation, examples include methylammonium (MA), ethylammonium (EA), formamidinium (FA), and guanidium (GA). In this embodiment, from the viewpoint of the tolerance factor (TF) for the perovskite crystal structure, it is preferable that 60 mol% or more, preferably 70 mol% or more, and more preferably 80 mol% or more of the A-site material is at least one selected from the group consisting of cesium, MA, EA, FA, and GA. The A-site material may be only one type, or it may be two or more types.

[0027] The B-site material that constitutes the B-site of the perovskite crystal structure of the quantum dot material is usually a divalent metal ion. When the B-site material is a divalent metal ion, examples of the metal include group 14 metals such as lead (Pb), germanium (Ge), tin (Sn), and silicon (Si). The B-site material may be only one type, or two or more types. Also, within the range of 5% or less of the elemental ratio of these group 14 metals, it may contain antimony (Sb), bismuth (Bi), copper (Cu), nickel (Ni), cobalt (Co), iron (Fe), manganese (Mn), chromium (Cr), cadmium (Cd), europium (Eu), ytterbium (Yb), silver (Ag), etc.

[0028] The X-site material that constitutes the X-site of the perovskite crystal structure of the quantum dot material is usually a monovalent anion, and specifically can be a halogen ion. Examples of the halogen include chlorine (Cl), bromine (Br), and iodine (I). The X-site material may be only one type, or two or more types. Also, within the range of 20% or less of the elemental ratio of the X-site, it may contain cyanide, isothiocyanate, oxocyanate, thiocyanate, selenocyanate, sulfide, fulminate ion, azide ion, borohydride ion, hexafluorophosphate ion, etc., which are monovalent pseudohalide ions.

[0029] A, B, and X can be appropriately selected considering the energy band gap of the quantum dot material and the sizes of A, B, and X, etc. A p B q X r Specific examples of 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 ) rExamples 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), etc. However, this is not limited to these specific examples.

[0030] For the crystal structure of ABX3, which has a perovskite-type structure, to be stable, the TF is preferably in the range of 0.70 to 1.10. Examples of such compounds include CsPbBr3 (TF=0.86), FAPbBr3 (TF=1.01), CsPbI3 (TF=0.85), and CsSnI3 (TF=0.92).

[0031] The average particle size of the quantum dot material is not particularly limited as long as it is within the range in which it can function as a light-emitting material. The average particle size of the quantum dot material is usually 1 nm or more, preferably 2 nm or more, more preferably 4 nm or more, and usually 100 nm or less, preferably 30 nm or less, more preferably 20 nm or less, and particularly preferably 16 nm or less. When the average particle size of the quantum dot material is within the above range, high solvent dispersibility can be imparted. Furthermore, good solvent dispersibility allows for good processing into molded articles.

[0032] The average particle size of quantum dot materials is determined by the maximum wavelength (λ) of photoluminescence (PL) measured by a fluorescence spectrophotometer or similar instrument. PL It can be determined from ). The energy band gap of quantum dot material, which is a light-emitting material, changes depending on the particle size, λ PL This changes. For example, in the quantum dot material CsPbBr3, 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 500nm, with an average particle size of 15nm. PL This corresponds to 523 nm.

[0033] Quantum dot materials emit light in the visible to near-infrared wavelength range (300-1000 nm). This emission can be caused by photoexcitation or electrical excitation. When emission is caused by photoexcitation, the wavelength of the excitation light is 200-800 nm, specifically 250-750 nm, and more specifically 300-600 nm.

[0034] Alkali metal (A') may be bonded to the surface of the quantum dot material according to this embodiment. For example, alkali metal (A') may be coordinate-bonded to the surface of the quantum dot material. Typically, at least a portion of the A-site material on the surface of the quantum dot material can be replaced by alkali metal (A'). Furthermore, if the molded body further contains an organic acid, the organic acid can usually coordinate to the alkali metal (A'), so the quantum dot material may have a structure in which ligands containing alkali metal (A') are coordinate-bonded to at least a portion of its surface. Since the lattice energy increases as the ionic radius decreases, alkali metal (A') can form strong ionic bonds with halide ions occupying nearby X-sites, thus suppressing ligand desorption on the surface of the quantum dot material. The inventors surmise that suppressing ligand desorption on the surface of the quantum dot material is one of the factors that can suppress the shift of the emission wavelength peak over time. However, the technical scope of the present invention is not limited to the mechanism described above.

[0035] The amount of quantum dot material in the molded body can be appropriately adjusted depending on the application of the molded body, but is preferably 0.001 parts by weight or more, more preferably 0.05 parts by weight or more, even more preferably 0.1 parts by weight or more, preferably 5 parts by weight or less, more preferably 4 parts by weight or less, and even more preferably 3 parts by weight or less, per 100 parts by weight of the cyclic olefin polymer. This is because a molded body exhibiting good luminescence can be obtained by having the amount of quantum dot material in the molded body within the above range.

[0036] <2.2. Alkali Metals (A')> The alkali metal (A') contained in the molded body is an alkali metal with a smaller ionic radius than the A-site material in the quantum dot material. Examples of such alkali metals (A') include sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs). In this embodiment, the alkali metal (A') is preferably potassium (K) or rubidium (Rb), and is preferably potassium (K) from the viewpoint of ease of industrial availability.

[0037] The ratio of the ionic radius of alkali metal (A') to the ionic radius of the A-site material is usually 0.6 or higher, preferably 0.7 or higher, more preferably 0.8 or higher, and can be less than 1, preferably 0.98 or lower, and more preferably 0.95 or lower.

[0038] The type of alkali metal (A') contained in the molded body is appropriately selected depending on the type of A-site material in the quantum dot material. The ionic radius of the alkali metal (A') and the ionic radius of the A-site material in the quantum dot material are usually literature values, for example, the effective ionic radius described in the paper "Organic-Inorganic Perovskites: Structural Versatility for Functional Materials Design" by Bayrammurad Saparov and David B. Mitzi et al., Chemical Reviews Vol 116 April 4, 2016, and the 12-coordinate effective ionic radius described in the paper "Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides" by RD Shannon, Acta Cryst. (1976). A32, 751-767 can be adopted.

[0039] Furthermore, if the A-site material of the quantum dot material is a mixed material, that is, if the A-site material contains two or more different materials, the ionic radius averaged by the molar ratio of each material contained in the A-site material (a weighted average of ionic radii weighted by the proportion (mole ratio) of each material contained in the A-site material) is used as the ionic radius of the A-site material. For example, if the A-site material contains material A1 with an ionic radius x1 and material A2 with an ionic radius x2 in a molar ratio of A1:A2=a1:a2, the ionic radius of the A-site material can be calculated as (a1×x1+a2×x2) / (a1+a2). In this embodiment, if the A-site material of the quantum dot material contains two or more different materials, the ionic radius of alkali metal (A') is usually smaller than the ionic radius averaged by the molar ratio described above, but it is desirable that the ionic radius of alkali metal (A') is smaller than the ionic radius of all monovalent cations contained in the A-site material.

[0040] The alkali metal (A') content (mol%) in the A-site material of the quantum dot material is typically 0.05 mol% or more, preferably 0.06 mol% or more, more preferably 0.07 mol% or more, and typically 1.00 mol% or less, preferably 0.8 mol% or less, and even more preferably 0.6 mol% or less. By having the alkali metal (A') content within the above range, it is possible to produce a molded article in which the shift of the emission wavelength peak over time is suppressed.

[0041] The alkali metal (A') contained in molded products is usually obtained using a weak salt of alkali metal (A') as its raw material. Typically, an organic salt of alkali metal (A') is used as the weak salt. The organic salt of alkali metal (A') will be explained in the manufacturing method section below.

[0042] <2.3. Cyclic Olefin Polymers> The molded article contains a cyclic olefin polymer. Cyclic olefin polymers are typically non-curable polymers, and more specifically, thermoplastic polymers.

[0043] 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, or mixtures of two or more of these in any ratio. From the viewpoint of mechanical strength, heat resistance, etc., cyclic olefin polymers containing an alicyclic structure in the main chain are preferred.

[0044] 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.

[0045] 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 per alicyclic structure, when this range provides a high balance of mechanical strength, heat resistance, and moldability, making it preferable.

[0046] 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. A proportion of structural units having an alicyclic structure to all structural units within this range is preferable from the viewpoint of transparency and heat resistance.

[0047] 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.

[0048] 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. Furthermore, 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.In addition, 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, and 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.

[0049] Examples of monomers having a norbornene structure include bicyclo[2.2.1]hepto-2-ene (common name: norbornene), tricyclo[4.3.0.1 2,5Deca-3,7-diene (common name: dicyclopentadiene), 7,8-benzotricyclo[4.3.0.1 2,5 Deca-3-ene (common name: methanotetrahydrofluorene), tetracyclo[4.4.0.1 2,5 .1 7,10 Examples 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 in any ratio.

[0050] 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.

[0051] Examples of monomers copolymerizable with a monomer having a norbornene structure include monocyclic olefins such as cyclohexene, cycloheptene, and cyclooctene, and their derivatives; and cyclic conjugated dienes such as cyclohexadiene and cycloheptadiene, and their derivatives. A single monomer copolymerizable with a monomer having a norbornene structure may be used alone, or two or more types may be used in any ratio.

[0052] 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.

[0053] 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 any ratio.

[0054] 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.

[0055] 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.

[0056] Examples of norbornene-based polymer trade names include "ZEONOR" and "ZEONEX" from Nippon Zeon Corporation; "ARTON" from JSR Corporation; and "Apel" from Mitsui Chemicals, Inc.

[0057] 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. Alternatively, the polymer may be a copolymer of a vinyl alicyclic hydrocarbon monomer or a vinyl aromatic monomer with another monomer copolymerizable with these monomers. Examples of such 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.

[0058] 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 mean 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.

[0059] Examples of aromatic vinyl compounds corresponding to the repeating unit [I] include styrene; styrenes having C1-C6 alkyl groups 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; styrenes having halogen atoms as substituents, such as 4-chlorostyrene, dichlorostyrene, and 4-monofluorostyrene; styrenes having C1-C6 alkoxy groups as substituents, such as 4-methoxystyrene; styrenes having aryl groups as substituents, such as 4-phenylstyrene; vinylnaphthalenes such as 1-vinylnaphthalene and 2-vinylnaphthalene; and the like. These may be used individually or in combination of two or more in any ratio. Among these, aromatic vinyl compounds that do not contain polar groups, such as styrene and styrenes having C1-C6 alkyl groups as substituents, are preferred because they can reduce hygroscopicity, and styrene is particularly preferred due to its ease of industrial availability.

[0060] 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 mean repeating units having a structure obtained by polymerizing chain-like conjugated diene compounds.

[0061] 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. These may be used individually or in combination of two or more in any ratio. The chain-like conjugated diene compounds may be linear or branched.

[0062] The hydrides of vinyl aromatic hydrocarbon polymers are hydrides of polymers containing repeating units [I] derived from aromatic vinyl compounds. Preferably, the hydrides of polymers containing repeating units [I] derived from aromatic vinyl compounds are specific hydrogenated block copolymers [E]. The hydrogenated block copolymer [E] is a hydride obtained by hydrogenating the aforementioned block copolymer [D].

[0063] Hydrogenated vinyl aromatic hydrocarbon polymers are substances obtained by hydrogenating the unsaturated bonds of the vinyl aromatic hydrocarbon polymer. Here, the unsaturated bonds of the vinyl aromatic hydrocarbon polymer to be hydrogenated include both the carbon-carbon unsaturated bonds of the main chain and side chains of the polymer, as well as the carbon-carbon unsaturated bonds of the aromatic ring.

[0064] 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.

[0065] 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 components using luminescent resin ink and other components (e.g., substrates) can be improved.

[0066] 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 graft polymerization of the pre-reaction polymer with a compound having a silicon atom-containing polar group as a monomer. However, the modified product is not limited by its manufacturing method. An alkoxysilyl group is preferred as the silicon atom-containing polar group.

[0067] Examples of silicon-containing polar groups that can be used as monomers for graft polymerization include ethylenically unsaturated silane compounds having alkoxysilyl groups, such as 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.

[0068] 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.

[0069] The amount of polar group introduced is 1 The amount can be measured using 1H-NMR spectroscopy. Furthermore, when measuring the amount of polar groups introduced, if the amount is small, the number of integration steps can be increased.

[0070] Introducing alkoxysilyl groups as polar groups into a polymer before reaction is called silane modification. In silane modification, the alkoxysilyl groups may be directly bonded to the polymer before reaction, or they may be bonded via divalent organic groups such as alkylene groups. Hereafter, the polymer obtained by silane modification of the polymer before reaction will also be called a "silane-modified polymer."

[0071] 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.

[0072] The weight-average molecular weight Mw of the cyclic olefin polymer is preferably 10,000 or more, more preferably 15,000 or more, particularly preferably 20,000 or more, preferably 100,000 or less, more preferably 80,000 or less, and particularly preferably 50,000 or less. When the weight-average molecular weight is within this range, the mechanical strength and moldability of the cyclic olefin polymer are highly balanced.

[0073] The molecular weight distribution (Mw / Mn) of the cyclic olefin polymer is preferably 1.2 or higher, more preferably 1.5 or higher, particularly preferably 1.8 or higher, preferably 3.5 or lower, more preferably 3.0 or lower, and particularly preferably 2.7 or lower. Here, Mn represents the number-average molecular weight. By setting the molecular weight distribution above the lower limit of the above range, the productivity of the cyclic olefin polymer can be increased and manufacturing costs can be suppressed. Furthermore, by setting it below the upper limit, the amount of low-molecular-weight components is reduced. As a result, relaxation of the layer using the composition when exposed to high temperatures can be suppressed, and the stability of the layer can be increased.

[0074] 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, on a polyisoprene or polystyrene basis.

[0075] In the total polymer contained in the molded article, the weight percentage of the cyclic olefin polymer is preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. The upper limit of the weight percentage is 100% by weight. This is because setting the proportion of the cyclic olefin resin within the above range effectively suppresses the shift in the emission wavelength peak.

[0076] <2.4. Any component> The molded article contains at least the aforementioned quantum dot material, alkali metal (A'), and cyclic olefin polymer, and may further contain any optional components as needed. Optional components may include, for example, organic acid compounds and organic base compounds. If organic acid compounds and organic base compounds are included, these compounds may coordinate to the quantum dot material as organic ligands. If organic ligands are included, the organic ligands may coordinate to the A-site material, B-site material, and X-site material contained in the quantum dot material, or to the alkali metal (A'). Details of the organic acid compounds and organic base compounds used as organic ligands will be described in the manufacturing method section below.

[0077] In addition, optional components include, for example, radical scavengers such as hindered amine-based light stabilizers, phenol-based light stabilizers, and complex light stabilizers, as well as ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and benzophenone-based ultraviolet absorbers.

[0078] Furthermore, the molded article according to this embodiment typically contains no solvent, or if it does, it contains a solvent to an extent that is unavoidable in the manufacturing process of the molded article. Preferably, the amount of solvent is 1 part by weight or less, and more preferably 0.5 parts by weight or less, relative to the molded article.

[0079] <3. Morphology of the molded body> There are no restrictions on the form of the molded article, and it can take various forms depending on its intended use. A film is a preferred form for such a molded article.

[0080] When the molded product 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.

[0081] The film according to this embodiment may have a configuration consisting only of a film layer containing the above-mentioned composition, or it may have a configuration in which a film layer containing the above-mentioned composition is disposed on a substrate as a support. Examples of substrate materials include resin and glass.

[0082] Furthermore, the film according to this embodiment may further include any additional layers, such as a barrier layer or a light scattering layer.

[0083] Another example of a molded body form is, for example, a cap material for an element such as a light-emitting diode (LED) element.

[0084] <4. Characteristics of the molded product> The molded body according to this embodiment can emit light when the quantum dot material is excited. For example, when the molded body is irradiated with excitation light, the quantum dot material is excited by the excitation light and can emit light. Conventionally, the emission wavelength peak of the light thus obtained tended to shift over time to a different wavelength. In contrast, the molded body according to this embodiment can suppress the time-dependent shift of the emission wavelength peak. Therefore, the absolute value of the amount of change (shift) over time of the emission wavelength peak can be reduced, and preferably, the amount of change can be eliminated. In one example, with an irradiation intensity of 100 mW / cm² 2When an evaluation test is performed in which the device is irradiated with excitation light for 5 hours, the absolute value of the change in the emission wavelength peak can be reduced to 2 nm or less. The change in the emission wavelength peak can be measured, for example, by the method described in <Evaluation of Change in Emission Wavelength Peak> in the example described later.

[0085] Furthermore, the molded article according to this embodiment can usually obtain a good PLQY. In addition, the molded article according to this embodiment preferably suppresses the deterioration of the quantum dot material itself over time.

[0086] <5. Method for manufacturing molded articles> The molded articles described above can be manufactured by any manufacturing method, but it is preferable that they be manufactured by a method comprising, for example, a first step of obtaining a composition containing a quantum dot material, an alkali metal (A'), and a cyclic olefin polymer, and a second step of forming a molded article using the composition.

[0087] The method for manufacturing a molded article, including the first and second steps, will be described below as the method for manufacturing a molded article according to this embodiment.

[0088] <5.1. First step> The first step is to obtain a composition comprising a quantum dot material, an alkali metal (A'), and a cyclic olefin polymer.

[0089] The method for obtaining the composition in the first step is not particularly limited. One preferred example is a method comprising the steps of: obtaining a dispersion containing a quantum dot material and an alkali metal (A') (1-1); obtaining a solution of a cyclic olefin polymer (1-2); and mixing the dispersion and the solution (1-3).

[0090] Another preferred example of a method for obtaining the composition in the first step is a method comprising the steps of obtaining a dispersion containing a quantum dot material and an alkali metal (A') (1-1) and dissolving the cyclic olefin polymer in the dispersion (1-4).

[0091] Method 1, which includes steps (1-1) to (1-3), and Method 2, which includes steps (1-1) and (1-4), will be explained below.

[0092] (1) Method 1 Method 1 is a method comprising the steps of obtaining a dispersion containing a quantum dot material and an alkali metal (A') (1-1), obtaining a solution of a cyclic olefin polymer (1-2), and mixing the dispersion and the solution (1-3).

[0093] (1-1. Step to obtain a dispersion containing quantum dot material and alkali metal (A')) In step (1-1), there are no restrictions on the method for obtaining a dispersion containing the quantum dot material and the alkali metal. However, preferred examples include a method comprising the steps of: preparing a precursor solution containing the raw materials for the quantum dot material and a polar solvent; mixing the obtained precursor solution with a nonpolar solvent to obtain the quantum dot material; and mixing the dispersion containing the obtained quantum dot material with a weak salt solution containing a weak salt of the alkali metal (A') to obtain a dispersion containing the target quantum dot material and alkali metal (A'); or a method comprising the steps of: preparing a precursor solution containing the raw materials for the quantum dot material, a weak salt of the alkali metal (A') and a polar solvent; mixing the obtained precursor solution with a nonpolar solvent to obtain a dispersion containing the target quantum dot material and alkali metal (A').

[0094] In the following explanation, in order to distinguish between a dispersion containing quantum dot material (a dispersion that does not contain alkali metal (A')) and a dispersion containing both quantum dot material and alkali metal (A'), the dispersion containing quantum dot material (a dispersion that does not contain alkali metal (A')) will be referred to as a "single dispersion," and the dispersion containing both quantum dot material and alkali metal (A') will be referred to as a "mixed dispersion."

[0095] Examples of raw materials for quantum dot materials that can be used to prepare precursor solutions include compounds containing the A-site material, compounds containing the B-site material, and compounds containing the X-site material, specifically the halide of the A-site material (AX) and the halide of the B-site material (BX2).

[0096] For example, the halide (AX) of the A-site material is A + Monovalent cations 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. In addition, examples of halides for A-site materials include A + Compounds consisting of an organic cation and the aforementioned halide ion include, for example, methylamine hydrohalide (MAX), ethylamine hydrohalide (EAX), formamidine hydrohalide (FAX), and guanidine hydrohalide (GAX). Among these A-site material halides, 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. These compounds can be used individually or in any ratio of two or more.

[0097] As for the B-site material halide (BX2), B 2+Examples include compounds consisting of lead ions, germanium ions, and tin ions, and the aforementioned halide ions. Of these, lead(II) bromide (PbBr2), lead(II) iodide (PbI2), lead(II) chloride (PbCl2), tin(II) bromide (SnBr2), tin(II) iodide (SnI2), tin(II) chloride (SnCl2), germanium(II) bromide (GeBr2), germanium(II) iodide (GeI2), and germanium(II) chloride (GeCl2) are preferred. These compounds can be used individually or in any ratio of two or more.

[0098] The mixing ratio (AX:BX2) of the halide (AX) from the A-site material and the halide (BX2) from the B-site material is typically 1:10 to 10:1 in molar ratio, preferably 1:3 to 3:1, and more preferably 1:1.5 to 1.5:1. This is because having the mixing ratio within this range suppresses the decrease in PLQY caused by the formation of perovskite crystal structures with different valencies of the metal elements in the quantum dot material.

[0099] As the polar solvent, a solvent capable of dissolving the precursor of the quantum dot material is used, and usually, a polar solvent miscible with the nonpolar solvent described later is used. As such a polar solvent, an aprotic organic solvent with a liquid dielectric constant of 30 μS / cm or higher is preferred, and specifically, examples 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). Furthermore, if the precursor solution contains an organic ligand, a solvent capable of dissolving the organic ligand is usually used as the polar solvent.

[0100] As a nonpolar solvent that can be mixed with the precursor solution, a nonpolar solvent that is miscible with the polar solvents mentioned above is used. Such a nonpolar solvent is preferably an organic solvent with a liquid dielectric constant of 10 μS / cm or less. Specifically, this includes 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 Examples include ether acetate (PMA, 8.03 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℃)), 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). These can be used individually or mixed in any ratio of two or more, as long as the liquid dielectric constant after mixing is 10 μS / cm or less.

[0101] In this embodiment, it is preferable that at least one of the precursor solution and the nonpolar solvent contains an organic ligand. The organic ligand is a coordinating organic compound. The organic ligand can contribute to uniformizing the particle size and filling surface defects during the production of quantum dot materials. There are no restrictions on the content of the organic ligand, and it can be appropriately adjusted to achieve the effects described above.

[0102] When an organic ligand is included in either the precursor solution or the nonpolar solvent, it may be mixed with the precursor solution first and then mixed with the nonpolar solvent, or it may be mixed with the nonpolar solvent first and then mixed with the precursor solvent.

[0103] Organic acid ligands are compounds (organic acid compounds) that form coordinate bonds with the anions that make up quantum dot materials, specifically B in the general formula ABX3.

[0104] 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). Specific organic acid ligands 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 acid and diisooxylphosphine acid. These compounds can be used individually or in any ratio of two or more.

[0105] Organic base ligands are compounds that form a coordinate bond with the cation that forms the quantum dot material, i.e., mainly X in ABX3, or compounds (organic base compounds) that form a coordinate bond by substituting the cation portion of the organic base ligand with the monovalent cation that forms the quantum dot material, i.e., A in ABX3.

[0106] Examples of organic base ligands include aliphatic amines, aromatic amines, and quaternary ammonium salts. Specific examples of organic base ligands 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-dimethyloctadecylammonio)propanesulfonate salt, and stearyltrimethylammonium salt. These compounds can be used individually or as a mixture of two or more in any ratio.

[0107] The precursor solution, nonpolar solvent, and ligands used as needed can be mixed at a predetermined liquid temperature. The liquid temperature is typically 40°C or lower, preferably 35°C or lower, more preferably 30°C or lower, and typically 10°C or higher, preferably 15°C or higher, more preferably 20°C or higher. This is because the quantum dot material can be stably synthesized by mixing the precursor solution and the nonpolar solvent within the aforementioned liquid temperature range. The precursor solution and the nonpolar solvent typically form a suspension upon mixing.

[0108] The precursor solution and the nonpolar solvent are usually mixed to form a suspension, which typically contains quantum dot material in its solid content. The solid content separated from the suspension may contain not only quantum dot material with the desired particle size but also coarse powder. Therefore, it is preferable to include a step of classifying the solid content recovered from the suspension to remove the coarse powder.

[0109] In the process of removing coarse powder, the solids are first recovered by sedimentation separation of the obtained suspension. Preferably, this is done by separating the solids in the suspension using centrifugal force and recovering the settled solids (centrifugal separation method). The centrifugal separation method can be performed using a known centrifugal separator, adjusting the rotation speed as appropriate. Through the above process, the suspension can usually be separated into a supernatant liquid and solids, and the solids can be obtained by removing the supernatant liquid.

[0110] Next, the solids removed from the suspension are dispersed in a nonpolar solvent to prepare a pre-dispersion, and then the solids are classified to remove coarse powder. The nonpolar solvent can be appropriately selected from among the nonpolar solvents that can be used to prepare the suspension as described above.

[0111] A preferred method for classifying the solid content and removing coarse powder is to separate the coarse powder from the pre-dispersion by centrifugal force. When the pre-dispersion is centrifuged, the quantum dot material having the desired particle size usually exists dispersed in the supernatant, while the coarse powder may settle. By removing the coarse powder from the pre-dispersion after centrifugation, a single dispersion containing the quantum dot material can be obtained. In the first step, any components can be appropriately selected and mixed with the obtained single dispersion as needed.

[0112] A single dispersion containing quantum dot material can be mixed with a weak salt solution containing an alkali metal (A') to obtain a mixed dispersion containing both the quantum dot material and the alkali metal.

[0113] Weak alkali metal (A') salts are typically organic acid salts in which the hydrogen ions of an organic acid are replaced by alkali metal (A') ions. Organic acids include carboxylic acids such as oleic acid, stearic acid, palmitic acid, glutaric acid, sebaciate benzoic acid, and 3,4,5-tri(2-propenoxy)benzoic acid, phosphorus oxoacid compounds such as octylphosphonic acid, tetradecylphosphonic acid, and di-tert-octylphosphinic acid, sulfonic acid compounds, and benzenesulfinic acid. Among these, oleic acid is preferred. This is because oleic acid has a low melting point and is liquid at room temperature (23°C), so it can also function as a solvent.

[0114] The weak salt solution may contain an additional solvent if necessary. A nonpolar solvent capable of dissolving organic acids can be used as the solvent.

[0115] Solutions of alkali metal (A') organic acid salts can be obtained, for example, by mixing alkali metal (A') hydroxide or carbonite with an organic acid. For example, when potassium carbonate (K2CO3) and oleic acid (CH3(CH2)7CH=CH(CH2)7-COOH) are mixed, an organic acid salt (CH3(CH2)7CH=CH(CH2)7-COOK) is obtained. This reaction can be represented by the following chemical formula (1). K2CO3+2CH3(CH2)7CH=CH(CH2)7-COOH →2CH3(CH2)7CH=CH(CH2)7-COOK+H2O+CO2(1)

[0116] Examples of alkali metal (A') organic acid salts include potassium oleate (POAc), sodium oleate (SOAc), and rubidium oleate (ROAc). These compounds can be used individually or in any ratio of two or more. The organic acid used in the organic acid salt and the organic acid used in the organic acid ligand may be the same compound, or different compounds may be used.

[0117] The ratio of a weak alkali metal (A') salt solution to a single dispersion containing quantum dot material is typically adjusted as needed so that the alkali metal content (mol%) relative to the A-site material in the quantum dot material is in the desired proportion.

[0118] As a method for preparing the dispersion containing the quantum dot material and alkali metal (A') described above, a method of preparing a single dispersion containing the quantum dot material and then mixing it with an alkali metal organic acid salt solution has been described in detail. However, as another example, a precursor solution containing the raw materials for the quantum dot material, a weak alkali metal (A') acid salt, and a polar solvent may be prepared, and the dispersion may be obtained by mixing the obtained precursor solution with a nonpolar solvent. In this method as well, at least one of the polar solvent or the nonpolar solvent may contain an organic ligand. The quantum dot material, the weak alkali metal (A') acid salt, the polar solvent, the nonpolar solvent, and the organic ligand used as needed can be appropriately selected from the examples described above.

[0119] (1-2. Step to obtain a solution of cyclic olefin polymer) The cyclic olefin polymer used in the dissolution of the cyclic olefin polymer can be appropriately selected depending on the application of the molded article.

[0120] The solvent used in the dissolution of the cyclic olefin polymer is not particularly limited as long as it is capable of dissolving the cyclic olefin polymer, but usually the nonpolar solvents mentioned above can be used. Furthermore, the nonpolar solvent used for the cyclic olefin polymer and the nonpolar solvent used for the dispersion of the quantum dot material and alkali metal (A') may be the same or different. The former is more preferable. This is because it allows for good dispersibility of the cyclic olefin polymer, quantum dot material and alkali metal (A') in the mixed solution, resulting in a molded article with good uniformity of the quantum dot material and alkali metal (A') within the molded article.

[0121] The weight percentage of the olefin polymer in the solution is preferably 5% by weight or more, more preferably 15% by weight or more, preferably 50% by weight or less, and more preferably 45% by weight or less, depending on the molecular weight and composition of the cyclic olefin polymer.

[0122] (1-3. Step of mixing the dispersion and the dissolving solution) The composition is obtained by mixing the dispersion and the solvent. The mixing ratio of quantum dot material and alkali metal (A') in the composition can be appropriately selected depending on the application of the composition, but it is preferable to mix the dispersion and the dissolving solution so that, for example, the weight ratio of quantum dot material to olefin polymer is the desired ratio.

[0123] (2) Method 2 Method 2 is a method comprising the steps of obtaining a dispersion containing a quantum dot material and an alkali metal (A') (1-1) and dissolving the cyclic olefin polymer in the dispersion (1-4).

[0124] Step (1-1) in Method 2 may be the same as the content described in Step (1-1) in Method 1 above.

[0125] In Method 1, a solution is prepared by dissolving the cyclic olefin polymer in a solvent beforehand, and then the dispersion of the quantum dot material and alkali metal (A') is dispersed with the olefin polymer solution. In steps (1-4), the cyclic olefin polymer is added to the dispersion of the quantum dot material and alkali metal (A'), and the cyclic olefin polymer is dissolved in the dispersion medium (solvent) to mix the quantum dot material and the olefin polymer. In step 4, for example, it is preferable to add the cyclic olefin polymer to the dispersion of the quantum dot material and then stir to promote the dissolution of the olefin polymer.

[0126] <5.2.Second process> The second step is to form a molded body using the composition obtained in the first step.

[0127] The method for forming the molded body can be appropriately selected depending on the form of the molded body. For example, if the molded body is a film, it is preferable to include the steps of forming a composition layer using the composition and drying the composition layer.

[0128] The method for forming the composition layer is not particularly limited as long as a composition layer having the desired thickness can be obtained. For example, this could involve coating a substrate with the composition or filling a mold with the composition to form the composition layer, but the former is more preferred.

[0129] If the second step includes a step of applying the composition, the method of applying the composition may include, for example, a die coater, a gravure coater, a comma coater, a knife coater, and an inkjet method.

[0130] The thickness of the composition layer is adjusted as appropriate depending on the solid content concentration in the composition and the desired film thickness.

[0131] Any method that can remove the solvent contained in the composition layer is acceptable for drying the composition layer, and any method can be adopted depending on the boiling point of the solvent used. Examples of drying methods include natural drying, heat drying, vacuum drying, and vacuum heat drying.

[0132] Furthermore, if the molded body is a cap material for an element, the molded body can be formed by extruding the composition and drying it.

[0133] <6. Applications of molded products> The molded body according to this embodiment can exhibit light conversion and photoelectric conversion functions by containing quantum dot material. Therefore, the molded body can be used, for example, as a light conversion element in a light-emitting device, a photoelectric conversion element in a power-generating device, or a light conversion element in a display.

[0134] <7. Light-emitting device> A light-emitting device according to one embodiment of the present invention comprises the molded body described above. In this light-emitting device, the molded body can typically function as a light conversion element.

[0135] According to this embodiment, by using the molded body as a light conversion element, a light-emitting device can be made in which the temporal change in wavelength of the light emitted from the molded body is suppressed. Furthermore, it can be made into a light-emitting device that generally has good luminous efficiency.

[0136] 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.

[0137] Any light source capable of emitting light of a wavelength that can be used as excitation light for quantum dot materials is acceptable, and known light sources such as light-emitting diodes (LEDs) and lasers can be cited. Among these, LEDs are preferred, and blue light-emitting diodes (blue LEDs) and ultraviolet light-emitting diodes (ultraviolet LEDs) are more preferred.

[0138] For example, when using a blue light-emitting diode as a light source, it is preferable that the quantum dot material included in the molded body includes a quantum dot material that emits red fluorescence and a quantum dot material that emits 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 created.

[0139] <8. Power Generation Equipment> A power generation device according to one embodiment of the present invention comprises the molded body described above. In this power generation device, the molded body can function as a power generation element.

[0140] According to this embodiment, by using the molded body as a power generation element, a power generation device with good power generation efficiency that does not change over time can be obtained.

[0141] In this embodiment, the power generation device utilizes the semiconductor function of a quantum dot material having a perovskite crystal structure, and is also referred to as a perovskite solar cell. The power generation element is also referred to as the active layer.

[0142] 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, the aforementioned film 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.

[0143] <9.Display> A display body according to one embodiment of the present invention comprises the molded body described above. In this display body, the molded body can function as a light conversion element.

[0144] According to this embodiment, by using the molded body as a light conversion element, the change in wavelength of the light emitted from the molded body over time is suppressed, thereby making it possible to create a display body in which the change in the color of the displayed image over time is suppressed.

[0145] 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 "OLED display devices").

[0146] 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 of 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 usually has a separate light source, and comprises the light source, a film as a light conversion element, and the liquid crystal panel in that order.

[0147] 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 generate 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 panel is an organic EL panel, the film as a light conversion element is placed on the viewing side of the organic EL panel. [Examples]

[0148] 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 modified and implemented as appropriate without departing from the scope of the claims and equivalents of the present invention.

[0149] In the following explanation, "%" and "parts" refer to weight unless otherwise specified. Furthermore, the operations described below were performed under normal temperature and pressure (23°C, 1 atm) conditions in the atmosphere unless otherwise specified.

[0150] [Evaluation Method] <Evaluation of Emission Wavelength Peak Change> The emission wavelength peaks of the light-emitting films obtained in Examples 1-6 and Comparative Examples 1-5 were measured before and after the light durability test. The emission wavelength peaks were measured using a fluorescence spectrophotometer FP-8600 (manufactured by JASCO Corporation; excitation wavelength 450 nm). In the light durability test, the light-emitting film was placed on an electronic cooling device, and the contact surface of the light-emitting film was set to 25°C. An LED area irradiator (manufactured by CCS, wavelength 450nm) was set parallel to the contact surface and at an irradiation distance of 100mm, and the irradiation intensity to the light-emitting film was set to 100mW / cm². 2 The irradiation intensity was set to [specific value], and light irradiation was performed for 5 hours. Value of the emission wavelength peak λ before the light endurance test PL(before) And the value of the emission wavelength peak after the light endurance test λ PL(after) The difference (λ PL(before) -λ PL(after) This was calculated as the change in the emission wavelength peak (change EW). The calculated change in EW was evaluated using the following indicators. Good: The absolute value of the change EW is 2nm or less. Defect: The absolute value of the change EW is greater than 2 nm.

[0151] <Changes in emission wavelength peak over time> In the light-emitting films of Examples 1-4 and Comparative Examples 1-2, the change in EW was measured at light irradiation times of 1 hour, 3 hours, and 5 hours in the light durability test. The results are shown in Figure 1.

[0152] <PLQY of dispersion> The PLQY and average particle size of the quantum dot material in the dispersions were measured for the mixed dispersions containing quantum dot material and alkali metal (A'), and for the single dispersions containing quantum dot material, prepared in the examples and comparative examples. The measurements were performed using a fluorescence spectrophotometer FP-8600 (JASCO Corporation; excitation wavelength 370 nm) equipped with an integrating sphere. Samples were prepared by diluting the dispersions with spectroscopic toluene (Fujifilm Wako Pure Chemical Industries, Ltd.) to a sample absorption rate of 0.50.

[0153] [Example 1] (1) Manufacturing of mixed dispersion (first step) Follow these steps to access POAc 0.12 A mixed dispersion containing CsPbBr3 was prepared.

[0154] A precursor solution was prepared by dissolving 170.4 mg (0.8 mmol) of cesium bromide (CsBr, Tokyo Chemical Industries, Ltd.) and 293.6 mg (0.8 mmol) of lead(II) bromide (PbBr2, Tokyo Chemical Industries, Ltd.) in 16 mL of N,N-dimethylformamide (DMF, Tokyo Chemical Industries, Ltd.).

[0155] As a nonpolar solution, a nonpolar solution was prepared by dissolving 3.3 mL (10.4 mmol) of oleic acid (OA, Tokyo Chemical Industry Co., Ltd.) and 43.2 μL (0.134 mmol) of oleylamine (OAm, Tokyo Chemical Industry Co., Ltd.) in 10 mL of ethyl acetate (EA, Fujifilm Wako Pure Chemical Industries, Ltd.).

[0156] The obtained nonpolar solution was placed entirely into a screw-cap tube, and 1.6 mL of the precursor solution was injected while stirring at room temperature under atmospheric pressure. The mixture was then mixed for 3 minutes to obtain a suspension. 1.9 mL of the suspension was placed into a centrifuge tube and centrifuged at 16500 rpm (18360 G) for 3 minutes using a benchtop centrifuge AS165W (manufactured by AS ONE Corporation). The supernatant was then removed to obtain crude nanoparticles.

[0157] A pre-dispersion was prepared by dispersing crude nanoparticles in 0.3 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 was collected from the pre-dispersion after centrifugation. The same procedure was repeated several times, and 2 mL of the collected supernatant was placed in a screw tube.

[0158] A weak salt solution was prepared by mixing 138.21 mg (1.0 mmol) of potassium carbonate (POC, Fujifilm Wako Pure Chemical Industries, Ltd.) with 20 mL (63.0 mmol) of OA.

[0159] Add 80 μL of the weak salt solution to a screw tube containing the supernatant liquid so that the molar ratio of CsPbBr3 in the supernatant liquid to POAc in the weak salt solution is CsPbBr3:POAc = 1:0.12, and stir for 2 minutes to extract POAc. 0.12 A mixed dispersion of CsPbBr3 was obtained. The photoluminescence quantum yield (PLQY) of the obtained mixed dispersion was 93.2%. The average particle size was 6.6 nm.

[0160] (2) Manufacturing of light-emitting film (second process) Follow these steps to access POAc 0.12 A light-emitting film containing CsPbBr3 and a cyclic olefin polymer (COP) was manufactured.

[0161] 43.5 g (50 mL) of toluene was mixed in a 100 mL screw-cap tube with 28.9 g (40% by weight) of a cyclic olefin polymer (norbornene-based polymer, ZEONOR, COP, manufactured by Nippon Zeon Corporation) as the polymer, using a rotating stand at 600 rpm for 24 hours. The complete dissolution of the polymer was confirmed visually, and the solution was obtained.

[0162] 7 g of the polymer solution and 1.7 mL of the mixed dispersion were placed in a 50 mL screw-cap bottle and mixed using a mixing device "Awatori Rentaro AR-100" (manufactured by Silky Co., Ltd.) by kneading for 20 minutes and degassing for 30 seconds. The mixture was confirmed to emit light uniformly using a handy UV lamp (AS ONE Corporation, ultraviolet wavelength 365 nm) to obtain the composition. The obtained composition contains quantum dot material in the range of 0.001 parts by weight to 5 parts by weight per 100 parts by weight of polymer.

[0163] The composition was uniformly molded 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 Industries Co., Ltd.) with a gap set to 560 μm. The molded body was dried on the auto film applicator at room temperature for 30 minutes, and the molded body was peeled off the base film to obtain the POAc on the film. 0.12 A light-emitting film of / CsPbBr3 / COP was obtained. The film thickness was measured using a digital thickness gauge (PG02A, manufactured by Teclock Co., Ltd.) and was found to be 110 μm. The obtained light-emitting film was evaluated using the evaluation method described above.

[0164] [Example 2] The same procedure as in Example 1 was followed, except that the concentration of the weak salt solution was changed by setting the amount of OA contained in the weak salt solution to 10 mL (31.5 mmol), so that the molar ratio of CsPbBr3 in the supernatant and POAc in the weak salt solution was CsPbBr3:POAc = 1:0.24. 0.24 and a mixed dispersion containing CsPbBr3 and POAc 0.24 A light-emitting film containing CsPbBr3 and COP was obtained. The PLQY of the obtained mixed dispersion was 93.4%. The obtained light-emitting film was also evaluated using the same procedure as in Example 1.

[0165] [Example 3] The procedure was the same as in Example 2, except that 160 μL of a weak salt solution was mixed with the supernatant liquid recovered from the pre-dispersion by centrifugation, and the molar ratio of CsPbBr3 in the supernatant liquid to POAc in the weak salt solution was set to CsPbBr3:POAc = 1:0.47. 0.47 and a mixed dispersion containing CsPbBr3 and POAc 0.47 A light-emitting film containing CsPbBr3 and COP was obtained. The PLQY of the obtained mixed dispersion was 95.3%. The obtained light-emitting film was also evaluated using the same procedure as in Example 1.

[0166] [Example 4] The same procedure as in Example 1 was followed, except that the concentration of the weak salt solution was changed by setting the amount of OA contained in the weak salt solution to 33.3 mL (104.9 mmol), so that the molar ratio of CsPbBr3 in the supernatant and POAc in the weak salt solution was CsPbBr3:POAc = 1:0.07. 0.07 and a mixed dispersion containing CsPbBr3 and POAc 0.07 A light-emitting film containing CsPbBr3 and COP was obtained. The PLQY of the obtained mixed dispersion was 89.8%. The obtained light-emitting film was also evaluated using the same procedure as in Example 1.

[0167] [Example 5] The same procedure as in Example 1 was followed, except that the POC mixed into the weak salt solution was changed to rubidium carbonate (ROC, Fujifilm Wako Pure Chemical Industries, Ltd.) 230.95 mg (1.0 mmol), and the molar ratio of CsPbBr3 in the supernatant to ROAc in the weak salt solution was set to CsPbBr3:ROAc = 1:0.12. 0.12 and a mixed dispersion containing CsPbBr3 and ROAc 0.12 A light-emitting film containing CsPbBr3 and COP was obtained. The PLQY of the obtained mixed dispersion was 94.3%. The obtained light-emitting film was also evaluated using the same procedure as in Example 1.

[0168] [Comparative Example 1] The same procedure as in Example 1 was followed, except that a weak salt solution was not added, to obtain a single dispersion of CsPbBr3 and a luminescent film containing CsPbBr3 and COP. The PLQY of the obtained mixed dispersion was 60.3%. The obtained luminescent film was also evaluated using the same procedure as in Example 1.

[0169] [Comparative Example 2] The same procedure as in Example 1 was followed, except that the concentration of the weak salt solution was changed by adding 100 mL (315.1 mmol) of OA to the weak salt solution, so that the molar ratio of CsPbBr3 in the supernatant and POAc in the weak salt solution was CsPbBr3:POAc = 1:0.02. 0.02 and a mixed dispersion containing CsPbBr3 and POAc 0.02 A light-emitting film containing CsPbBr3 and COP was obtained. The PLQY of the obtained mixed dispersion was 90.7%. The obtained light-emitting film was also evaluated using the same procedure as in Example 1.

[0170] [Example 6] (1) Manufacturing of mixed dispersion (first step) Follow these steps to access POAc 0.40 A mixed dispersion containing MAPbBr3 was prepared.

[0171] A precursor solution was prepared by dissolving 22.4 mg (0.20 mmol) of methylammonium bromide (MABr, Tokyo Chemical Industries, Ltd.) and 132.1 mg (0.36 mmol) of lead(II) bromide (PbBr2, Tokyo Chemical Industries, Ltd.) in 1 mL of N,N-dimethylformamide (DMF, Tokyo Chemical Industries, Ltd.). As a nonpolar solution, a mixed solvent was prepared by dissolving 15 μL (0.046 mmol) of oleic acid (OA, Tokyo Chemical Industries, Ltd.) and 8 μL (0.048 mmol) of octylamine (OcAm, Tokyo Chemical Industries, Ltd.) in 5 mL of propylene glycol monomethyl ether acetate (PGM-Ac, Tokyo Chemical Industries, Ltd.). The obtained nonpolar solution was placed in a screw-cap vial, and 0.2 mL of the precursor solution was added while stirring at room temperature under atmospheric pressure. The mixture was then mixed for 3 minutes to obtain a suspension. 1.35 mL of the suspension was placed in a centrifuge tube and centrifuged at 16500 rpm (18360 G) for 3 minutes using a benchtop centrifuge AS165W (manufactured by AS ONE Corporation). The supernatant was then removed to obtain crude nanoparticles. A pre-dispersion was prepared by adding 1 mL of toluene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a redispersant to crude nanoparticles and dispersing them. The obtained pre-dispersion was centrifuged at 16,500 rpm for 2 minutes. The supernatant was collected from the pre-dispersion after centrifugation. The same procedure was repeated several times, and 2 mL of the collected supernatant was placed in a screw tube.

[0172] A weak salt solution was prepared by mixing 138.21 mg (1.0 mmol) of POC and 20 mL (63.0 mmol) of OA. The molar ratio of MAPbBr3 in the supernatant and POAc in the weak salt solution was adjusted to CsPbBr3:POAc = 1:0.40. 80 μL of the weak salt solution was added to a screw tube containing the supernatant, and the mixture was stirred for 2 minutes to remove POAc. 0.40 A mixed dispersion containing MAPbBr3 was obtained. The optical properties were measured using the same procedure as in Example 1, and the PLQY of the resulting mixed dispersion was 84.2%.

[0173] (2) Manufacturing of light-emitting film (second process) The composition was obtained using the same procedure as in Example 1, except that the materials for the composition were 7 g of a polymer solution prepared using the same procedure as in Example 1 and 1.7 mL of the mixed dispersion.

[0174] Using the same procedure as in Example 1, POAc 0.40 A luminescent film containing MAPbBr3 and COP was obtained.

[0175] [Comparative Example 3] A mixed dispersion containing MAPbBr3 and a luminescent film containing MAPbBr3 and COP were obtained using the same procedure as in Example 6, except that a weak salt solution was not added. The PLQY of the obtained mixed dispersion was 82.1%.

[0176] [Comparative Example 4] Except for changing the polymer added to the polymer solution from COP to polymethyl methacrylate polymer (PMMA), the same procedure as in Example 1 was followed, and POAc 0.12 A light-emitting film containing CsPbBr3 and PMMA was fabricated.

[0177] [Comparative Example 5] A light-emitting film containing CsPbBr3 / PMMA was prepared using the same procedure as in Comparative Example 1, except that the resin added to the polymer solution was changed to PMMA.

[0178] The results are shown in Table 1 and Figure 1. The chemical compositions in Table 1 represent the alkali metal (A') weak salt, quantum dot material, and polymer used in the manufacture of the molded product, expressed as "alkali metal (A') weak salt / quantum dot material / polymer". The abbreviations in Table 1 have the following meanings. "POAc": Potassium oleate "ROAc": Rubidium oleate "COP": norbornene polymer "PMMA": Polymethyl methacrylate polymer "Alkali metal (A') content": Molar equivalent of alkali metal (A') relative to the A-site material of the quantum dot material. "Ionic radius of alkali metal (A')": This is the ratio of the ionic radius of alkali metal (A') to the ionic radius of the A-site material of the quantum dot material. The ionic radius values ​​used in the calculation are 1.64 Å for potassium (K), 1.72 Å for rubidium (Rb), 1.88 Å for cesium (Cs), and 2.17 Å for methylammonium (MA).

[0179] [Table 1]

[0180] It was confirmed that the PLQY of the mixed dispersions prepared in Examples 1-4, 6 and Comparative Example 2 was significantly improved compared to the single dispersions prepared in Comparative Examples 1 and 3. Patent Document 1 states that adding a weak salt of 0.01 eq or more is sufficient to fill surface defects in the quantum dot material in the dispersion, and since the amount of weak salt added in Examples 1-4, 6 and Comparative Example 2 was 0.01 eq or more, it is considered that the effect described in Patent Document 1 was reproduced.

[0181] On the other hand, as shown in Figure 1, while Comparative Example 2 showed a suppression effect on the change in the emission wavelength peak for a very short period of about one hour, it was confirmed that it was insufficient to suppress the change in the emission wavelength peak.

[0182] Comparing Comparative Example 4 and Comparative Example 5, it was found that even with PMMA resin, some suppression of changes in the emission wavelength peak could be obtained. However, if the emission wavelength peak fluctuates by more than 2 nm, it becomes unsuitable for practical use. Therefore, it was confirmed that the effect of suppressing the change in the emission wavelength peak over time in the emission film can be achieved by using a cyclic olefin polymer containing 0.05 eq or more of a weak alkali metal (A') salt in relation to the quantum dot material.

[0183] Light-emitting films are used in optical devices as components that convert incident light to wavelengths specific to quantum dot materials. In such light-emitting films, if the emission wavelength peak changes over time, there is a concern that the color emitted from the film will change, potentially degrading or hindering the function of the optical device itself. The technology according to the present invention has been confirmed to suppress changes in the emission wavelength peak over time, allowing the characteristics of the light-emitting film to be maintained for extended periods. This technology contributes to extending the lifespan of optical devices.

Claims

1. Quantum dot materials having a perovskite crystal structure, An alkali metal having a smaller ionic radius than the A-site material constituting the A-site of the perovskite-type crystal structure of the quantum dot material, It includes a cyclic olefin polymer, A molded article in which the alkali metal content of the quantum dot material relative to the A-site material is 0.05 mol% or more.

2. The molded article according to claim 1, wherein the cyclic olefin polymer is a non-curing polymer.

3. The cyclic olefin polymer includes a norbornene polymer. The molded article according to claim 1, wherein the norbornene polymer comprises at least one selected from 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 a hydride thereof.

4. The cyclic olefin polymer comprises a hydrogenated block copolymer [E], The hydrogenated block copolymer [E] comprises a polymer block [A] mainly composed of repeating units [I] derived from an aromatic vinyl compound, The molded article according to claim 1, which is a hydrogenated block copolymer obtained by hydrogenating a block copolymer [D] comprising 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.

5. The molded article according to claim 4, wherein the cyclic olefin polymer contains an alkoxysilyl group.

6. The molded article according to claim 1, wherein the amount of the quantum dot material is 0.001 parts by weight or more and 5 parts by weight or less per 100 parts by weight of the cyclic olefin polymer.

7. The molded body according to claim 1, wherein the molded body is a film.

8. A light-emitting device using the molded body described in claim 1 as a light-converting element.

9. A power generation device using the molded body described in claim 1 as a power generation element.

10. A display body using the molded body described in claim 1 as a light conversion element.

11. A method for manufacturing a molded article according to claim 1, A first step to obtain a composition comprising the quantum dot material, the alkali metal, and the cyclic olefin polymer, A method for manufacturing a molded article, comprising a second step of forming a molded article using the aforementioned composition.

12. The first step is, A step of obtaining a dispersion containing the quantum dot material and the alkali metal, A step of obtaining a solution of the cyclic olefin polymer, A method for producing a molded article according to claim 11, comprising the step of mixing the dispersion and the dissolving solution.

13. The first step is, A step of obtaining a dispersion containing the quantum dot material and the alkali metal, A method for producing a molded article according to claim 11, comprising the step of dissolving the cyclic olefin polymer in the dispersion.

14. The second step includes the step of applying the composition, The method for manufacturing a molded article according to claim 11, wherein the method for applying the composition is selected from the group consisting of die coater method, gravure coater method, comma coater method, knife coater method, and inkjet method.

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