Wavelength conversion component

Abstract

To provide a highly reliable wavelength conversion component. [Solution] A wavelength conversion member comprising a wavelength conversion layer containing quantum dots. The wavelength conversion layer is a cured product of a curable composition containing quantum dots, a first (meth)acrylate containing four or more functional (meth)acrylic groups, and a thiol compound, and has a glass transition temperature of 50°C to 100°C. The curable composition has a molar ratio of the total content of (meth)acrylic groups to the total content of thiol groups of 1.50 to 3.00.

Description

Technical Field

[0001] The present disclosure relates to a wavelength conversion member.

Background Art

[0002] A wavelength conversion member containing quantum dots is used, for example, as a light source for an image display device, and high color reproducibility can be obtained. However, the light emission intensity of a wavelength conversion member containing quantum dots may decrease in a high temperature and high humidity environment. In relation to this, for example, Patent Document 1 discloses a wavelength conversion member including a cured product containing an alkyleneoxy structure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] One aspect of the present disclosure aims to provide a wavelength conversion member with excellent reliability.

Means for Solving the Problems

[0005] [[ID=4|2]]A first aspect is a wavelength conversion member including a wavelength conversion layer containing quantum dots. The wavelength conversion layer is a cured product of a curable composition containing quantum dots, a first (meth)acrylate containing four or more functional (meth)acrylic groups, and a thiol compound, and has a glass transition temperature of 50°C or higher and 100°C or lower. In the curable composition, the molar ratio of the total content of (meth)acrylic groups to the total content of thiol groups is 1.50 or higher and 3.00 or lower.

Effects of the Invention

[0006] According to one aspect of the present disclosure, a wavelength conversion member with excellent reliability can be provided.

Brief Description of the Drawings

[0007] [Figure 1] This figure shows an example of the emission spectrum of a quantum dot. [Modes for carrying out the invention]

[0008] In this specification, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, as long as their intended purpose is achieved. Furthermore, the content of each component in a composition means the total amount of multiple substances present in the composition, unless otherwise specified, if multiple substances corresponding to each component exist in the composition. In addition, the upper and lower limits of numerical ranges described herein can be arbitrarily selected and combined from the numerical values ​​exemplified as numerical ranges. In this specification, (meth)acrylate is a general term for acrylates, methacrylates, and mixtures thereof, and the same applies to other similar expressions. Furthermore, solids mean the residue remaining after removing volatile components (e.g., organic solvents) from a composition or its components. In this specification, in formulas representing the composition of a phosphor or luminescent material, multiple elements separated by commas (,) mean that at least one of these multiple elements is contained in the composition. Furthermore, in formulas representing the composition of a phosphor, the element before the colon (:) represents the matrix crystal, and the element after the colon (:) represents the activating element. In this specification, the relationship between color names and chromaticity coordinates, the relationship between the wavelength range of light and the color names of monochromatic light, etc., shall conform to JIS Z8110. The full width at half maximum (FWHM) of a phosphor refers to the wavelength width (FWHM) of the emission spectrum in which the emission intensity is 50% of the maximum emission intensity. Embodiments of the present invention will be described in detail below. However, the embodiments shown below are illustrative examples of wavelength conversion members for realizing the technical concept of the present invention, and the present invention is not limited to the wavelength conversion members shown below.

[0009] Wavelength conversion component The wavelength conversion member comprises a wavelength conversion layer containing at least quantum dots as a light-emitting material. The wavelength conversion layer may be a cured product of a curable composition containing quantum dots, a first (meth)acrylate containing four or more functional (meth)acrylic groups, and a thiol compound. The glass transition temperature of the cured product of the curable composition may be, for example, 50°C to 100°C. The curable composition may contain quantum dots, a thiol compound, and a polymerizable compound containing at least a first (meth)acrylate. The molar ratio of the total content of (meth)acrylic groups in the polymerizable compound to the total content of thiol groups in the thiol compound may be, for example, 1.92 to 2.75.

[0010] The wavelength conversion layer is a cured product of a curable composition containing a first (meth)acrylate containing four or more (meth)acrylic groups and a thiol compound, and has a glass transition temperature of 50°C to 100°C. For example, degradation of quantum dots contained in the wavelength conversion layer is suppressed, improving the reliability of the wavelength conversion member. This can be thought of as follows: The crosslinking density is improved by the first (meth)acrylate, which can suppress the intrusion of oxygen, water, etc., which are factors that degrade quantum dot materials in high temperature and high humidity environments.

[0011] Wavelength conversion components offer excellent reliability. Here, "excellent reliability" means excellent resistance to moisture and heat.

[0012] The wavelength conversion layer contains quantum dots. Quantum dots are semiconductor crystal particles with particle sizes ranging from a few nanometers to several tens of nanometers. When the size of a material is reduced to the nanometer order, electrons can only exist in a limited state within the material. Therefore, the electronic state becomes discrete, and the band gap changes depending on the particle size. Quantum dots absorb light and emit light with a wavelength corresponding to their band gap energy. Therefore, by controlling the particle size, crystal composition, etc., the emission wavelength of quantum dots can be controlled, and quantum dots function as wavelength conversion materials. The particle size of the quantum dots contained in the wavelength conversion layer may be, for example, 50 nm or less. Preferably, the particle size of the quantum dots may be 1 nm to 20 nm, 1.6 nm to 8 nm, or 2 nm to 7.5 nm.

[0013] Here, the particle size of the semiconductor nanoparticles constituting the quantum dot refers to the longest line segment that passes through the center of the particle, connecting any two points on its outer circumference as observed in a transmission electron microscope (TEM) image. The average particle size of the semiconductor nanoparticles refers to the arithmetic mean of the particle sizes of each semiconductor nanoparticle whose particle size can be measured as observed in a TEM image.

[0014] When semiconductor nanoparticles have a rod-like shape, the length of the minor axis is considered to be the particle size. Here, a rod-like particle refers to a particle that, when observed on a plane including the major axis, is observed as a quadrilateral (with a cross-section that is a circle, ellipse, or polygon), elliptical, or polygonal (for example, a pencil-like shape), and whose ratio of the length of the major axis to the length of the minor axis is greater than 1.2. For a rod-like particle, the length of the major axis refers to the longest line segment connecting any two points on the outer circumference of the particle in the case of an elliptical shape, and the longest line segment connecting any two points on the outer circumference of the particle that is parallel to the longest side defining the outer circumference in the case of a quadrilateral or polygonal shape. The length of the minor axis refers to the longest line segment connecting any two points on the outer circumference that is perpendicular to the line segment defining the length of the major axis. Specifically, the average particle size of semiconductor nanoparticles is determined by measuring the particle size of all measurable semiconductor nanoparticles observed in TEM images at magnifications between 50,000x and 150,000x, and then taking the arithmetic mean of these particle sizes. Here, "measurable" particles are those whose entire contour can be observed in the TEM image. Therefore, particles that are partially not included in the imaging range of the TEM image and are "cut off" are not measurable. If a single TEM image contains 100 or more nanoparticles in total, the average particle size is determined using that single TEM image. If a single TEM image contains a small number of nanoparticles, the imaging location is changed to obtain additional TEM images, and the particle size of 100 or more particles contained in two or more TEM images is measured to determine the average particle size.

[0015] Specific examples of quantum dots include perovskite quantum dots, chalcopyrite quantum dots, and indium phosphide (InP) quantum dots. Perovskite quantum dots may contain, for example, a compound represented by the following formula (1). [M 1 w A 1 (1-w) ] x M 2 y X z (1)

[0016] In the above formula (1), M 1 represents a first element containing at least one selected from the group consisting of Cs, Rb, K, Na, and Li. A 1 represents a non-metallic cation containing at least one selected from the group consisting of ammonium ion, formamidinium ion, guanidinium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, and protonated thiourea ion. M 2 represents a second element containing at least one selected from the group consisting of Ge, Sn, Pb, Sb, and Bi. X represents an anion or ligand containing at least one selected from the group consisting of chloride ion, bromide ion, iodide ion, cyanide ion, thiocyanate, isothiocyanate, and sulfide. x is a number from 1 to 4, y is a number from 1 to 2, z is a number from 3 to 9, and w is a number from 0 to 1. In the above formula (1), when both the first element M 1 and the non-metallic cation A 1 are included, both the first element M 1 and the non-metallic cation A 1 represent atomic groups constituting a ligand.

[0017] The ammonium ion may be represented by, for example, the following formula (A-1). The formamidinium ion may be represented by, for example, the following formula (A-2). The guanidinium ion may be represented by, for example, the following formula (A-3). The protonated thiourea ion may be represented by, for example, the following formula (A-4). The imidazolium ion may be represented by, for example, the following formula (A-5). The pyridinium ion may be represented by, for example, the following formula (A-6). The pyrrolidinium ion may be represented by, for example, the following formula (A-7). In each formula representing a non-metallic cation, R independently represents at least one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a benzyl group, a halogen atom, and a pseudohalogen. Any two Rs in each formula may be linked to each other to form a nitrogen-containing aliphatic ring having 3 to 6 carbon atoms.

[0018] [R4N +(A-1) [(NR2)2RC + (A-2) [(NR2)3C + (A-3) [(NR2)2C + -SR] (A-4)

[0019] [ka]

[0020] A perovskite quantum dot containing a compound having the composition represented by formula (1) emits green or red light when irradiated with light from a light source. With regard to green light, the perovskite quantum dot may emit light with a peak emission wavelength in the range of 475 nm to 560 nm when irradiated with light from a light source having a peak emission wavelength in the range of 380 nm to 545 nm, preferably from a light source having a peak emission wavelength in the range of 380 nm to 500 nm. The peak emission wavelength of a green-emitting perovskite quantum dot may preferably be in the range of 510 nm to 560 nm, 520 nm to 560 nm, or 525 nm to 535 nm. With regard to red light, the perovskite quantum dot may emit light with a peak emission wavelength in the range of 600 nm to 680 nm when irradiated with light from a light source having a peak emission wavelength in the range of 320 nm to 545 nm, preferably from a light source having a peak emission wavelength in the range of 320 nm to 450 nm. The emission peak wavelength of a perovskite quantum dot emitting red light is preferably within the range of 610 nm to 670 nm, 620 nm to 660 nm, or 625 nm to 635 nm. Furthermore, the full width at half maximum in the emission spectrum of the perovskite quantum dot may be, for example, 35 nm or less, preferably 30 nm or less, or 25 nm or less. The perovskite quantum dot may also exhibit band-edge emission in its emission spectrum.

[0021] A first embodiment of a chalcopyrite-based quantum dot may comprise a first semiconductor containing, for example, silver (Ag), indium (In), gallium (Ga), and sulfur (S), with a second semiconductor containing Ga and S disposed on its surface. The second semiconductor may further contain Ag. The first semiconductor may be a semiconductor having a chalcopyrite-type structure containing Ag, In, Ga, and S. In the first embodiment of the chalcopyrite-based quantum dot, an adsorbent containing the second semiconductor may be disposed on the surface of a particle containing the first semiconductor, and the adsorbent containing the second semiconductor may cover the particle containing the first semiconductor. Furthermore, the chalcopyrite-based quantum dot may have a core-shell structure in which, for example, a particle containing the first semiconductor serves as the core, and an adsorbent containing the second semiconductor serves as the shell, with the shell disposed on the surface of the core. For details of the chalcopyrite-based quantum dot of the first embodiment, refer to, for example, Japanese Patent Application Publication No. 2018-044142, International Publication No. 2022 / 191032, etc.

[0022] The first semiconductor may contain at least Ag, and a portion of it may be substituted to further contain at least one of copper (Cu), gold (Au), and alkali metals (hereinafter sometimes referred to as Ma), and may be substantially composed of Ag. Here, "substantially" means that the ratio of the number of atoms of elements that substitute for Ag other than Ag to the total number of atoms of Ag and elements that substitute for Ag other than Ag is, for example, 10% or less, preferably 5% or less, and more preferably 1% or less. The first semiconductor may also be substantially composed of Ag and alkali metals. Here, "substantially" means that the ratio of the number of atoms of elements that substitute for Ag other than alkali metals to the total number of atoms of Ag, alkali metals, and elements that substitute for Ag other than Ag and alkali metals is, for example, 10% or less, preferably 5% or less, and more preferably 1% or less. Alkali metals include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs).

[0023] The first semiconductor may have, for example, a composition represented by the following formula (2a). (Agp M a (1-p) ) q In r Ga (1-r) S (q+3) / 2 (2a)

[0024] Here, p, q, and r satisfy 0 < p ≤ 1, 0.20 < q ≤ 1.2, and 0 < r < 1. M a represents an alkali metal.

[0025] In the first aspect of the chalcopyrite-based quantum dots, a second semiconductor may be disposed on the surface. The second semiconductor may include a semiconductor having a larger bandgap energy than the first semiconductor. The second semiconductor may be a semiconductor consisting essentially of Ga and S. Further, the second semiconductor may be a semiconductor consisting essentially of Ag, Ga, and S. Here, "consisting essentially of" means that when the total number of atoms of all elements contained in a semiconductor containing Ga and S, or a semiconductor containing Ag, Ga, and S, is taken as 100%, the proportion of atoms of elements other than Ga and S, or other than Ag, Ga, and S, is, for example, 10% or less, preferably 5% or less, more preferably 1% or less.

[0026] The chalcopyrite-based quantum dots of the first aspect may exhibit band-edge emission having an emission peak wavelength in the wavelength range of, for example, 475 nm or more and 560 nm or less (for example, green) upon light irradiation from a light source having an emission peak wavelength in the range of 380 nm or more and 545 nm or less. The emission peak wavelength may preferably be in the range of 510 nm or more and 550 nm or less, 515 nm or more and 545 nm or less, or 525 nm or more and 535 nm or less. Further, the chalcopyrite-based quantum dots of the first aspect may have a full-width at half-maximum in its emission spectrum of, for example, 45 nm or less, preferably 40 nm or less, 35 nm or less, or 30 nm or less. The full-width at half-maximum may be, for example, 15 nm or more.

[0027] The second aspect of chalcopyrite-based quantum dots may include a third semiconductor containing, for example, copper (Cu), silver (Ag), indium (In), gallium (Ga), and sulfur (S), and a fourth semiconductor containing Ga and S may be disposed on its surface. The fourth semiconductor may further contain Ag. The third semiconductor may be a semiconductor having a chalcopyrite-type structure containing Cu, Ag, In, Ga, and S. In the second aspect of chalcopyrite-based quantum dots, an attachment containing a fourth semiconductor may be disposed on the surface of a particle containing a third semiconductor, and the attachment containing a fourth semiconductor may cover the particle containing a third semiconductor. Further, the chalcopyrite-based quantum dots may have, for example, a core-shell structure in which a particle containing a third semiconductor is used as a core and an attachment containing a fourth semiconductor is used as a shell, and the shell is disposed on the surface of the core. For details of the chalcopyrite-based quantum dots of the second aspect, reference can be made to, for example, the descriptions in International Publication No. 2020 / 162622, International Publication No. 2023 / 013361, etc.

[0028] The third semiconductor contains at least Ag and Cu, and a part of it may be substituted to contain gold (Au) and an alkali metal (Ma). The third semiconductor may substantially have Ag, Cu, and an alkali metal as constituent elements. Here, "substantially" means that the ratio of the number of atoms of elements other than Ag, Cu, and an alkali metal to the total number of atoms of Ag, Cu, and an alkali metal and elements other than Ag, Cu, and an alkali metal is, for example, 10% or less, preferably 5% or less, and more preferably 1% or less. <>

[0029] The third semiconductor may have, for example, a composition represented by the following formula (2b). (Ag s Cu (1-s) ) t In u Ga (1-u) S (t+3) / 2 (2b)

[0030] Here, s, t, and u satisfy 0 < s < 1, 0.20 < t ≤ 1.2, and 0 < u < 1.

[0031] In a second embodiment of the chalcopyrite-based quantum dot, a fourth semiconductor may be disposed on the surface. The fourth semiconductor may include a semiconductor with a larger bandgap energy than the third semiconductor. The fourth semiconductor may be a semiconductor substantially composed of Ga and S. Alternatively, the fourth semiconductor may be a semiconductor substantially composed of Ag, Ga, and S. Here, "substantially" means that when the total number of atoms of all elements contained in the semiconductor containing Ga and S, or the semiconductor containing Ag, Ga, and S, is taken as 100%, the proportion of atoms of elements other than Ga and S, or elements other than Ag, Ga, and S, is, for example, 10% or less, preferably 5% or less, and more preferably 1% or less.

[0032] The chalcopyrite-based quantum dot of the second embodiment may exhibit band-edge emission with an emission peak wavelength in the wavelength range of 600 nm to 680 nm (e.g., red) when irradiated with light from a light source having an emission peak wavelength in the range of 380 nm to 545 nm, and the emission peak wavelength may preferably be in the range of 610 nm to 670 nm, 620 nm to 660 nm, or 625 nm to 635 nm. Furthermore, the full width at half maximum (FWHM) of the emission spectrum of the chalcopyrite-based quantum dot of the second embodiment may be, for example, 70 nm or less, preferably 65 nm or less, 60 nm or less, or 30 nm or less. The FWHM may be, for example, 15 nm or more.

[0033] A third embodiment of the chalcopyrite-based quantum dot may be configured by including, for example, a fifth semiconductor containing silver (Ag), gallium (Ga), and selenium (Se), with a sixth semiconductor containing zinc (Zn) and sulfur (S) disposed on its surface. The fifth semiconductor may contain at least Ag, Ga, and Se, and a portion thereof may be substituted to contain indium (In) and sulfur (S). The sixth semiconductor may further contain at least one of Ga and Se. The fifth semiconductor may be a semiconductor having a chalcopyrite-type structure containing Ag, Ga, and Se. In the third embodiment of the chalcopyrite-based quantum dot, a deposit containing the sixth semiconductor may be disposed on the surface of a particle containing the fifth semiconductor, and the deposit containing the sixth semiconductor may cover the particle containing the fifth semiconductor. Furthermore, the chalcopyrite-based quantum dot may have a core-shell structure in which, for example, a particle containing the fifth semiconductor serves as the core, and a deposit containing the sixth semiconductor serves as the shell, with the shell disposed on the surface of the core. For details of the chalcopyrite-based quantum dots of the third embodiment, refer to the description in, for example, International Publication No. 2021 / 039290.

[0034] The fifth semiconductor comprises at least Ag, Ga, and Se, and may be partially substituted to contain indium (In) and sulfur (S).

[0035] The fifth semiconductor may have, for example, a composition represented by the following formula (2c). AgIn x Ga (1-x) S y Se (1-y) (2c)

[0036] Here, x and y satisfy 0 ≤ x < 1 and 0 ≤ y ≤ 1.

[0037] In a third embodiment of the chalcopyrite quantum dot, a sixth semiconductor may be disposed on the surface. The sixth semiconductor may include a semiconductor with a larger bandgap energy than the fifth semiconductor. The sixth semiconductor may be a semiconductor substantially composed of Zn and S. Here, "substantially" means that when the total number of atoms of all elements contained in the semiconductor containing Zn and S is taken as 100%, the proportion of atoms of elements other than Zn and S is, for example, 10% or less, preferably 5% or less, and more preferably 1% or less.

[0038] The chalcopyrite-based quantum dot of the third embodiment may exhibit band-edge emission with an emission peak wavelength in the wavelength range of 600 nm to 680 nm (e.g., red) when irradiated with light from a light source having an emission peak wavelength in the range of 380 nm to 545 nm, and the emission peak wavelength may preferably be in the range of 610 nm to 670 nm, or 625 nm to 635 nm. Furthermore, the full width at half maximum (FWHM) of the emission spectrum of the chalcopyrite-based quantum dot of the third embodiment may be, for example, 50 nm or less, preferably 40 nm or less, or 30 nm or less. The FWHM may be, for example, 15 nm or more.

[0039] Indium phosphide (InP) quantum dots are a form of semiconductor nanoparticle containing III-V semiconductors. Examples of III-V semiconductors include AlN, AlP, AlAs, AlSb, GaAs, GaP, GaN, GaSb, InN, InAs, InP, InSb, TiN, TiP, TiAs, and TiSb.

[0040] III-V group quantum dots may have a deposit containing a seventh semiconductor different from the III-V semiconductor constituting the semiconductor nanoparticles arranged on the surface of semiconductor nanoparticles containing a III-V semiconductor, and the deposit containing the seventh semiconductor may cover the particles containing the III-V semiconductor. Furthermore, III-V group quantum dots may have a core-shell structure in which particles containing a III-V semiconductor serve as the core and a deposit containing the seventh semiconductor serves as the shell, with the shell arranged on the surface of the core. The seventh semiconductor may be a semiconductor with a larger bandgap energy than the III-V semiconductor. Examples of combinations of III-V semiconductors and the seventh semiconductor include InP / ZnS, GaP / ZnS, InN / GaN, InP / CdSSe, InP / ZnSeTe, InGaP / ZnSe, InGaP / ZnS, InP / ZnSTe, InGaP / ZnSTe, and InGaP / ZnSSe.

[0041] III-V semiconductor (e.g., indium phosphide-based) quantum dots may emit green or red light when irradiated with light from a light source having an emission peak wavelength in the range of, for example, 380 nm to 500 nm. III-V semiconductor quantum dots emitting green light may exhibit band-edge emission with an emission peak wavelength in the range of 475 nm to 580 nm when irradiated with light from a light source having an emission peak wavelength in the range of, for example, 380 nm to 545 nm, preferably from a light source having an emission peak wavelength in the range of, for example, 380 nm to 500 nm. The emission peak wavelength may preferably be in the range of 510 nm to 570 nm, 520 nm to 560 nm, or 525 nm to 535 nm. Furthermore, III-V semiconductor quantum dots emitting red light may exhibit band-edge emission with an emission peak wavelength in the wavelength range of 600 nm to 680 nm when irradiated with light from a light source having an emission peak wavelength in the range of 380 nm to 545 nm. The emission peak wavelength may preferably be in the range of 610 nm to 670 nm, 620 nm to 660 nm, or 625 nm to 635 nm. Furthermore, the full width at half maximum (FWHM) of the emission spectrum of the III-V semiconductor quantum dot may be, for example, 70 nm or less, preferably 65 nm or less, 60 nm or less, or 30 nm or less. The FWHM may be, for example, 15 nm or more.

[0042] The quantum dots may include other quantum dots besides perovskite-based quantum dots, chalcopyrite-based quantum dots, and indium phosphide-based quantum dots, as needed. Examples of other quantum dots include particles containing at least one selected from the group consisting of group II-VI semiconductors, group IV-VI semiconductors, and group IV semiconductors.

[0043] Examples of group II-VI semiconductors include CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgST Examples of e include CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, etc. Specific examples of IV-VI semiconductors include SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, etc. Specific examples of Group IV semiconductors include Si, Ge, SiC, and SiGe.

[0044] Quantum dots may have surface modifiers placed on their surfaces. Specific examples of surface modifiers include amino alcohols having 2 to 20 carbon atoms; ionic surface modifiers; nonionic surface modifiers; nitrogen-containing compounds having 4 to 20 hydrocarbon groups; sulfur-containing compounds having 4 to 20 hydrocarbon groups; oxygen-containing compounds having 4 to 20 hydrocarbon groups; phosphorus-containing compounds having 4 to 20 hydrocarbon groups; halides containing at least one element selected from the group consisting of Group 2, Group 12, and Group 13 elements. Surface modifiers may be used individually or in combination of two or more different types.

[0045] The amino alcohol used as a surface modifier may be any compound having an amino group and an alcoholic hydroxyl group, and containing a hydrocarbon group with 2 to 20 carbon atoms. The number of carbon atoms in the amino alcohol is preferably 10 or less, more preferably 6 or less. The hydrocarbon group constituting the amino alcohol may be derived from hydrocarbons such as linear, branched, or cyclic alkanes, alkenes, and alkynes. Derived from a hydrocarbon means that the hydrocarbon group is formed by removing at least two hydrogen atoms from a hydrocarbon. Specific examples of amino alcohols include aminoethanol, aminopropanol, aminobutanol, aminopentanol, aminohexanol, and aminooctanol. For example, when the amino group of an amino alcohol is bonded to the surface of a semiconductor nanoparticle, and the hydroxyl group is exposed on the opposite, outermost surface of the particle, a change in the polarity of the semiconductor nanoparticle occurs, improving its dispersibility in alcohol-based solvents (e.g., methanol, ethanol, propanol, butanol, etc.).

[0046] Examples of ionic surface modifiers used as surface modifiers include nitrogen-containing compounds, sulfur-containing compounds, and oxygen-containing compounds having ionic functional groups within their molecules. The ionic functional group may be cationic or anionic, but it is preferable that it has at least a cationic group. Specific examples of surface modifiers and methods of surface modification can be found, for example, in Chemistry Letters, Vol. 45, pp. 898-900, 2016.

[0047] The ionic surface modifier may be, for example, a sulfur-containing compound having a tertiary or quaternary alkylamino group. The number of carbon atoms in the alkylamino group may be, for example, 1 to 4. The sulfur-containing compound may also be an alkyl or alkenylthiol with 2 to 20 carbon atoms. Specific examples of ionic surface modifiers include hydrogen halides of dimethylaminoethanethiol, halogenated salts of trimethylammoniumethanethiol, hydrogen halides of dimethylaminobutanethiol, and halogenated salts of trimethylammoniumbutanethiol.

[0048] Examples of nonionic surface modifiers used as surface modifiers include nitrogen-containing compounds, sulfur-containing compounds, and oxygen-containing compounds having nonionic functional groups such as alkylene glycol units and alkylene glycol monoalkyl ether units. The number of carbon atoms in the alkylene group of the alkylene glycol unit may be, for example, 2 to 8, preferably 2 to 4. The number of repeating alkylene glycol units may be, for example, 1 to 20, preferably 2 to 10. Nitrogen-containing compounds constituting the nonionic surface modifier may have an amino group, sulfur-containing compounds may have a thiol group, and oxygen-containing compounds may have a hydroxyl group. Specific examples of nonionic surface modifiers include methoxytriethyleneoxyethanethiol and methoxyhexaethyleneoxyethanethiol.

[0049] Examples of nitrogen-containing compounds having hydrocarbon groups with 4 to 20 carbon atoms include amines and amides. Examples of sulfur-containing compounds having hydrocarbon groups with 4 to 20 carbon atoms include thiols. Examples of oxygen-containing compounds having hydrocarbon groups with 4 to 20 carbon atoms include carboxylic acids, alcohols, ethers, aldehydes, and ketones. Examples of phosphorus-containing compounds having hydrocarbon groups with 4 to 20 carbon atoms include trialkylphosphines, triarylphosphines, trialkylphosphine oxides, and triarylphosphine oxides.

[0050] Examples of halides containing at least one element selected from the group consisting of Group 2 elements, Group 12 elements, and Group 13 elements include magnesium chloride, calcium chloride, zinc chloride, cadmium chloride, aluminum chloride, and gallium chloride.

[0051] The quantum dots included in the wavelength conversion layer may include at least one selected from the group consisting of a first quantum dot having an emission peak wavelength in the wavelength range of 475 nm to 560 nm and a second quantum dot having an emission peak wavelength in the wavelength range of 600 nm to 680 nm. The quantum dots may include at least one of the first quantum dots and at least one of the second quantum dots. The first quantum dot may include at least one selected from the group consisting of, for example, perovskite quantum dots, indium phosphide quantum dots and chalcopyrite quantum dots of the first embodiment. Preferably, the first quantum dot may include at least one selected from the group consisting of perovskite quantum dots and chalcopyrite quantum dots of the first embodiment. The second quantum dot may also include at least one selected from the group consisting of, for example, perovskite quantum dots, chalcopyrite quantum dots of the second embodiment and indium phosphide quantum dots. Preferably, the second quantum dot may include at least one selected from the group consisting of chalcopyrite-based quantum dots and indium phosphide-based quantum dots according to the second embodiment. Because the wavelength conversion layer includes the first quantum dot and the second quantum dot, when the wavelength conversion layer is irradiated with blue light having a wavelength of, for example, 420 nm to 460 nm, green light and red light are emitted from the first quantum dot and the second quantum dot, respectively. As a result, white light is obtained by mixing the green light and red light emitted from the first and second quantum dots with the blue light transmitted through the wavelength conversion layer.

[0052] The wavelength conversion layer constituting the wavelength conversion member may be one layer or two or more layers. For example, if there are two wavelength conversion layers, one wavelength conversion layer may contain a first quantum dot and the other wavelength conversion layer may contain a second quantum dot. The wavelength conversion layer may, for example, contain a chalcopyrite-based quantum dot that emits green light and a chalcopyrite-based quantum dot that emits red light. The wavelength conversion layer may contain a chalcopyrite-based quantum dot that emits green light and an indium phosphide-based quantum dot that emits red light. The wavelength conversion layer may contain a perovskite-based quantum dot that emits green light and an indium phosphide-based quantum dot that emits red light. The wavelength conversion layer may contain a perovskite-based quantum dot that emits green light and a chalcopyrite-based quantum dot that emits red light. Furthermore, the wavelength conversion layer may include, for example, a layer containing chalcopyrite-based quantum dots that emit green light and a layer containing chalcopyrite-based quantum dots that emit red light. The wavelength conversion layer may include a layer containing chalcopyrite-based quantum dots that emit green light and a layer containing indium phosphide-based quantum dots that emit red light. The wavelength conversion layer may include a layer containing perovskite-based quantum dots that emit green light and a layer containing indium phosphide-based quantum dots that emit red light. The wavelength conversion layer may include a layer containing perovskite-based quantum dots that emit green light and a layer containing chalcopyrite-based quantum dots that emit red light.

[0053] The wavelength conversion layer may, in addition to quantum dots, optionally contain at least one phosphor as a light-emitting material other than quantum dots. Examples of phosphors include garnet-based phosphors such as aluminum garnet. Examples of garnet-based phosphors include yttrium-aluminum-garnet phosphors activated with cerium, and lutetium-aluminum-garnet phosphors activated with cerium. Other examples of garnet-based phosphors include nitrogen-containing calcium aluminosilicate phosphors activated with europium and / or chromium, silicate phosphors activated with europium, β-SiAlON phosphors, nitride phosphors such as CASN or SCASN, and LnSi3N 11Rare earth nitride phosphors such as the LnSiAlON system, BaSi2O2N2:Eu system, or Ba3Si6O 12 N2:Eu-based oxynitride phosphors, CaS-based, SrGa2S4-based, ZnS-based sulfide phosphors, chlorosilicate phosphors, SrLiAl3N4:Eu phosphors, SrMg3SiN4:Eu phosphors, K2SiF6:Mn phosphors and K2(Si,Al)F6:Mn phosphors as manganese-activated fluoride complex phosphors (e.g., K2Si 0.99 Al 0.01 F 5.99 You can use things like :Mn).

[0054] The wavelength conversion layer may, for example, include chalcopyrite-based quantum dots that emit green light and a manganese-activated fluoride complex phosphor that emits red light, or it may include perovskite-based quantum dots that emit green light and a manganese-activated fluoride complex phosphor that emits red light. Furthermore, the wavelength conversion layer may include a layer containing chalcopyrite-based quantum dots that emit green light and a layer containing a manganese-activated fluoride complex phosphor that emits red light.

[0055] The wavelength conversion layer may contain a cured resin formed from the resin component of the curable composition, in addition to quantum dots. The quantum dot content in the wavelength conversion layer may be, for example, 0.01% by mass or more and 1.0% by mass or less, preferably 0.05% by mass or more and 0.8% by mass or less, or 0.1% by mass or more and 0.7% by mass or less, relative to the total amount of cured resin. In one embodiment, the quantum dot content in the wavelength conversion layer may be 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, or 0.3% by mass or more, and may be 1.0% by mass or less, 0.8% by mass or less, 0.7% by mass or less, or 0.5% by mass or less, relative to the total amount of cured resin. When the quantum dot content is 0.01% by mass or more, sufficient luminescence intensity tends to be obtained when light is irradiated, and when the quantum dot content is 1.0% by mass or less, aggregation of quantum dots tends to be suppressed, and color unevenness tends to be suppressed.

[0056] The curable composition may include a resin component that forms a cured resin in addition to quantum dots. The resin component may include at least one thiol compound and a polymerizable compound, and the polymerizable compound may include at least a first (meth)acrylate containing four or more functional (meth)acrylic groups. The cured resin formed from the thiol compound and the polymerizable compound may include a sulfide structure formed by an enthiol reaction between the thiol group and the double bond of the (meth)acrylic group. This tends to suppress the degradation of the quantum dots. It also tends to improve the adhesion between the wavelength conversion layer and the barrier layer described later.

[0057] The thiol compound contained in the curable composition may be a monofunctional thiol compound having one thiol group (sulfanyl group) in the molecule, or a polyfunctional thiol compound having multiple thiol groups in the molecule. From the viewpoint of reliability as a wavelength conversion member, the thiol compound may contain at least a polyfunctional thiol compound, and may contain a polyfunctional thiol compound with three or more functions. The thiol compound contained in the curable composition may be a single compound or a combination of two or more compounds.

[0058] Specific examples of monofunctional thiol compounds include hexanethiol, 1-heptanethiol, 1-octanethiol, 1-nonanethiol, 1-decanethiol, 3-mercaptopropionic acid, methyl mercaptopropionate, methoxybutyl mercaptopropionate, octyl mercaptopropionate, tridecyl mercaptopropionate, 2-ethylhexyl-3-mercaptopropionate, and n-octyl-3-mercaptopropionate.

[0059] Specific examples of polyfunctional thiol compounds include ethylene glycol bis(3-mercaptopropionate), diethylene glycol bis(3-mercaptopropionate), tetraethylene glycol bis(3-mercaptopropionate), 1,2-propylene glycol bis(3-mercaptopropionate), diethylene glycol bis(3-mercaptobutyrate), 1,4-butanediol bis(3-mercaptopropionate), and 1,4-butanediol bis(3-mercaptopropionate). Lucaptobutyrate), 1,8-octanediol bis(3-mercaptopropionate), 1,8-octanediol bis(3-mercaptobutyrate), hexanediol bisthioglycolate, trimethylolpropantris(3-mercaptopropionate), trimethylolpropantris(3-mercaptobutyrate), trimethylolpropantris(3-mercaptoisobutyrate), trimethylolpropantris(2-mercaptoisobutyrate), Trimethylolpropantris(2-mercaptoisobutyrate), Trimethylol Tyrolpropane tristhioglycolate, tris[(3-mercaptopropionyloxy)-ethyl]isocyanurate, trimethylolethanetris(3-mercaptobutyrate), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), pentaerythritol tetrakis(3-mercaptoisobutyrate), pentaerythritol tetrakis(2-mercaptoisobutyrate), dipenta Examples include erythritol hexakis(3-mercaptopropionate), dipentaerythritol hexakis(2-mercaptopropionate), dipentaerythritol hexakis(3-mercaptobutyrate), dipentaerythritol hexakis(3-mercaptoisobutyrate), dipentaerythritol hexakis(2-mercaptoisobutyrate), pentaerythritol tetrakisthioglycolate, and dipentaerythritol hexakisthioglycolate.

[0060] From the viewpoint of reliability as a wavelength conversion material, the thiol compound may contain at least one of tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate and pentaerythritol tetrakis(3-mercaptopropionate).

[0061] The content of the thiol compound in the curable composition may be, for example, 15% by mass or more and 50% by mass or less, preferably 20% by mass or more, 25% by mass or more, 28% by mass or more, or 30% by mass or more, and may be 45% by mass or less, 40% by mass or less, 36% by mass or less, or 32% by mass or less, based on the total amount of the curable composition. When the content of the thiol compound is within the above range, the adhesion between the wavelength conversion layer and the barrier layer tends to improve. In addition, the reliability of the wavelength conversion member tends to improve.

[0062] The polymerizable compound contained in the curable composition may contain at least a first (meth)acrylate containing four or more (meth)acrylic groups. The number of (meth)acrylic groups contained in one molecule of the first (meth)acrylate is preferably five or more, or six. The first (meth)acrylate may also be a mixture of acrylate compounds containing four or more (meth)acrylic groups.

[0063] Specific examples of the first (meth)acrylate include tetra(meth)acrylate compounds such as ethylene oxide-added pentaerythritol tetra(meth)acrylate, trimethylolpropane tetra(meth)acrylate, and pentaerythritol tetra(meth)acrylate; penta(meth)acrylate compounds such as dipentaerythritol penta(meth)acrylate; and hexa(meth)acrylate compounds such as dipentaerythritol hexa(meth)acrylate. From the viewpoint of the reliability of the wavelength conversion member, the first (meth)acrylate may contain at least one selected from the group consisting of dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate, and may contain at least dipentaerythritol hexa(meth)acrylate.

[0064] The content of the first (meth)acrylate in the curable composition may be, for example, 5% by mass or more and 30% by mass or less, preferably 7% by mass or more, or 10% by mass or more, or 25% by mass or less, 20% by mass or less, or 15% by mass or less, based on the total amount of the curable composition. When the content of the first (meth)acrylate in the curable composition is within the above range, curing shrinkage during curing is suppressed, and the adhesion between the wavelength conversion layer and the barrier layer tends to be further improved.

[0065] Furthermore, the content of the first (meth)acrylate in the polymerizable compound may be, for example, 9% by mass or more and 40% by mass or less, preferably 13% by mass or more, or 15% by mass or more, and may be 37% by mass or less, 35% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total amount of the polymerizable compound. When the content of the first (meth)acrylate in the polymerizable compound is within the above range, curing shrinkage during curing is suppressed, and the adhesion between the wavelength conversion layer and the barrier layer tends to be further improved.

[0066] The polymerizable compound may further contain a bifunctional second (meth)acrylate containing two (meth)acrylic groups in addition to the first (meth)acrylate. The inclusion of both the first (meth)acrylate and the second (meth)acrylate in the polymerizable compound tends to further improve the reliability of the wavelength conversion component.

[0067] Specific examples of the second (meth)acrylate include alkylene glycol di(meth)acrylate compounds such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and 1,9-nonanediol di(meth)acrylate; polyalkylene glycol di(meth)acrylate compounds such as polyethylene glycol di(meth)acrylate and polypropylene glycol di(meth)acrylate; and tricyclodecanedimethanol di(meth)acrylate and cyclohexanedimethanol di(meth)acrylate. Examples include (meth)acrylate compounds having an alicyclic structure, such as 1,3-adamantanedimethanol di(meth)acrylate, hydrogenated bisphenol A (poly)ethoxydi(meth)acrylate, hydrogenated bisphenol A (poly)propoxydi(meth)acrylate, hydrogenated bisphenol F (poly)ethoxydi(meth)acrylate, hydrogenated bisphenol F (poly)propoxydi(meth)acrylate, hydrogenated bisphenol S (poly)ethoxydi(meth)acrylate, and hydrogenated bisphenol S (poly)propoxydi(meth)acrylate. The second (meth)acrylate may contain at least one selected from the group consisting of (meth)acrylate compounds having an alicyclic structure, and may contain at least tricyclodecanedimethanol di(meth)acrylate, from the viewpoint of the reliability of the wavelength conversion member.

[0068] When the curable composition contains a second (meth)acrylate, the content of the second (meth)acrylate in the curable composition may be, for example, 20% by mass or more and 60% by mass or less, preferably 22% by mass or more, 25% by mass or more, 30% by mass or more, or 40% by mass or more, and may be 55% by mass or less, 50% by mass or less, or 48% by mass or less, based on the total amount of the curable composition. When the content of the second (meth)acrylate is within the above range, the decrease in crosslinking density tends to be further suppressed.

[0069] When the curable composition contains a second (meth)acrylate, the content of the second (meth)acrylate in the polymerizable compound may be, for example, 40% to 80% by mass, preferably 45% or more by mass, or 47% or more by mass, or 75% or less by mass, or 70% or less by mass, based on the total amount of the polymerizable compound. When the content of the second (meth)acrylate is within the above range, the decrease in crosslink density tends to be further suppressed.

[0070] When the curable composition contains a first (meth)acrylate and a second (meth)acrylate as polymerizable compounds, the molar content ratio of the second (meth)acrylate to the first (meth)acrylate in the polymerizable compound may be, for example, 0.5 or more and 10 or less, preferably 0.8 or more and 8 or less. In one embodiment, the molar content ratio of the second (meth)acrylate to the first (meth)acrylate may be 0.5 or more, 0.8 or more, 1.5 or more, 2.0 or more, 2.4 or more, 3 or more, 4 or more, 6 or more, or 7 or more, and may be 10 or less, 9 or less, 8 or less, or 7.8 or less.

[0071] The curable composition may further contain a monofunctional (meth)acrylate having one (meth)acrylic group, if necessary. Specific examples of monofunctional (meth)acrylates include (meth)acrylic acid; alkyl (meth)acrylates with 1 to 18 carbon atoms in the alkyl group, such as methyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate; and aromatic compounds such as benzyl (meth)acrylate and phenoxyethyl (meth)acrylate. (Meth)acrylate compounds having a ring; alkoxyalkyl (meth)acrylates such as butoxyethyl (meth)acrylate; aminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate; diethylene glycol monoethyl ether (meth)acrylate, triethylene glycol monobutyl ether (meth)acrylate, tetraethylene glycol monomethyl ether (meth)acrylate, hexaethylene glycol monomethyl ether (meth)acrylate, octaethyl Polyalkylene glycol monoalkyl ether (meth)acrylates such as ethylene glycol monomethyl ether (meth)acrylate, nonaethylene glycol monomethyl ether (meth)acrylate, dipropylene glycol monomethyl ether (meth)acrylate, heptapropylene glycol monomethyl ether (meth)acrylate, and tetraethylene glycol monoethyl ether (meth)acrylate; polyalkylene glycol monoaryl ether (meth)acrylates such as hexaethylene glycol monophenyl ether (meth)acrylate; alicyclic (meth)acrylate compounds such as cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, and methylene oxide-added cyclodecatriene (meth)acrylate; heterocyclic (meth)acrylate compounds such as (meth)acryloylmorpholine and tetrahydrofurfuryl (meth)acrylate; alkyl fluoride (meth)acrylates such as heptadecafluorodecyl (meth)acrylate;Hydroxylated (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, hexaethylene glycol mono(meth)acrylate, octapropylene glycol mono(meth)acrylate; glycidyl (meth)acrylate compounds such as glycidyl (meth)acrylate; 2-(2-(meth)acryloyloxyethyl oxy)ethyl isocyanate, 2-(meth)acryloyloxyethyl Examples include (meth)acrylate compounds having isocyanate groups such as isocyanates; polyalkylene glycol mono(meth)acrylates such as tetraethylene glycol mono(meth)acrylate, hexaethylene glycol mono(meth)acrylate, and octapropylene glycol mono(meth)acrylate; and (meth)acrylamide compounds such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, and 2-hydroxyethyl(meth)acrylamide.

[0072] From the viewpoint of reliability of the wavelength conversion member, the monofunctional (meth)acrylate may contain at least one selected from the group consisting of (meth)acrylate compounds having an alicyclic structure, and may contain at least isobornyl (meth)acrylate.

[0073] When the curable composition contains monofunctional (meth)acrylate, the content of monofunctional (meth)acrylate in the curable composition may be, for example, 1% by mass or more and 20% by mass or less, preferably 1.5% by mass or more, 2% by mass or more, 5% by mass or more, 8% by mass or more, or 10% by mass or more, 17% by mass or less, or 15% by mass or less, based on the total amount of the curable composition. When the content of monofunctional (meth)acrylate is within the above range, the decrease in crosslinking density tends to be suppressed.

[0074] When the curable composition contains a monofunctional (meth)acrylate as a polymerizable compound, the molar content ratio of the monofunctional (meth)acrylate to the total amount of polymerizable compounds may be, for example, 0.1 or more and 1 or less, and preferably 0.2 or more and 0.5 or less.

[0075] The curable composition may further contain a trifunctional (meth)acrylate having three (meth)acrylic groups, if necessary. Specific examples of trifunctional (meth)acrylates include trimethylolpropane tri(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, and tris(2-acryloyloxyethyl) isocyanurate. When the curable composition contains a trifunctional (meth)acrylate, the molar content ratio of the trifunctional (meth)acrylate to the total amount of polymerizable compounds in the curable composition may be, for example, 0.2 or less, 0.15 or less, or 0.01 or less, and may be, for example, 0.001 or more.

[0076] The content ratio of thiol compounds to polymerizable compounds in the curable composition is expressed as the molar ratio of the total content of (meth)acrylic groups contained in the polymerizable compound to the total content of thiol groups contained in the thiol compound, and may be, for example, 1.50 or more and 3.0 or less, preferably 1.85 or more, 1.90 or more, 2.20 or more, or 2.50 or more, and may be 2.80 or less, or 2.60 or less. When the content ratio of thiol compounds to polymerizable compounds is within the above range, the reliability of the wavelength conversion member tends to improve further. The total content of thiol groups in the curable composition is calculated as the sum of the values ​​obtained by multiplying the number of moles of each thiol compound contained in the curable composition by the number of thiol groups contained in each thiol compound. The total content of (meth)acrylic groups in the curable composition is calculated as the sum of the values ​​obtained by multiplying the number of moles of each (meth)acrylate compound contained in the curable composition by the number of (meth)acrylic groups contained in each (meth)acrylate compound.

[0077] The curable composition may contain at least one photopolymerization initiator. Examples of photopolymerization initiators include compounds that generate radicals upon irradiation with active energy rays such as ultraviolet light.

[0078] Specific examples of photopolymerization initiators include benzophenone, N,N'-tetraalkyl-4,4'-diaminobenzophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propane-1-one, 4,4'-bis(dimethylamino)benzophenone (also known as "Michler's ketone"), 4,4'-bis(diethylamino)benzophenone, 4-methoxy-4'-dimethylaminobenzophenone, and 1-hydroxycyclohexyl Aromatic ketone compounds such as xylphenyl ketone, 1-(4-isopropylphenyl)2-hydroxy-2-methylpropan-1-one, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-2-methyl-1-propan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; quinone compounds such as alkylanthraquinone and phenanthrenequinone; benzoin compounds such as benzoin and alkylbenzoin; benzoin ethers such as benzoin alkyl ether and benzoin phenyl ether. Compounds; benzyl derivatives such as benzyldimethylketal; 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer, 2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer, etc. 2,4,5-triarylimidazole dimers; acridine derivatives such as 9-phenylacridine and 1,7-(9,9'-acridinyl)heptane; oxime ester compounds such as 1,2-octanedione 1-[4-(phenylthio)-2-(O-benzoyl oxime)] and ethanone 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyl oxime); coumarin compounds such as 7-diethylamino-4-methylcoumarin; thioxanthone compounds such as 2,4-diethylthioxanthone;Examples include acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide. A single photopolymerization initiator may be used alone, or two or more may be used in combination.

[0079] As a photopolymerization initiator, from the viewpoint of curability, at least one selected from the group consisting of acylphosphine oxide compounds, aromatic ketone compounds, and oxime ester compounds is preferred, at least one selected from the group consisting of acylphosphine oxide compounds and aromatic ketone compounds is more preferred, and acylphosphine oxide compounds are even more preferred.

[0080] The content of the photopolymerization initiator in the curable composition may be, for example, 0.1% by mass or more and 5% by mass or less, preferably 0.1% by mass or more and 3% by mass or 0.5% by mass or more and 1.5% by mass or less, based on the total amount of the curable composition. When the content of the photopolymerization initiator is 0.1% by mass or more, the sensitivity of the curable composition tends to be sufficient, and when the content of the photopolymerization initiator is 5% by mass or less, the influence on the hue of the curable composition and the decrease in storage stability tend to be suppressed.

[0081] The curable composition may further contain a light-diffusing material as needed. The inclusion of a light-scattering material tends to further improve the light conversion efficiency. Examples of light-diffusing materials include inorganic particles such as titanium dioxide, barium sulfate, zinc oxide, calcium carbonate, and silicon dioxide, and organic particles such as silicone (organopolysiloxane) particles. Among these, silicone particles are preferred.

[0082] The average particle size of the light diffusing material may be, for example, 0.1 μm or more and 5.0 μm or less, preferably 0.2 μm or more, and may be 4.0 μm or less or 3.0 μm or less. The average particle size of the light diffusing material is measured as follows: If the light diffusing material is contained in the curable composition, the extracted light diffusing material is dispersed in purified water containing a surfactant or an organic solvent to obtain a dispersion. Using this dispersion, the average particle size of the light diffusing material is defined as the value corresponding to 50% of the volume accumulation from the smallest diameter side (median diameter D50) in the volume-based particle size distribution measured with a laser diffraction particle size distribution analyzer (e.g., Shimadzu Corporation, SALD-3000J). As a method for extracting the light diffusing material from the curable composition, for example, the curable composition can be diluted in a liquid medium, and the light diffusing material can be precipitated and collected by centrifugation or the like. The average particle size of the light-diffusing material in a cured product obtained by curing a curable composition containing a light-diffusing material can be determined by observing the particles using a scanning electron microscope, calculating the equivalent circle diameter (geometric mean of the major and minor axes) for 50 particles, and then taking the arithmetic mean of these values.

[0083] The light diffusing material may have an organic layer containing organic matter on at least a portion of its surface. Having an organic layer on the surface can suppress aggregation of the light diffusing material in the curable composition. Examples of organic matter include organosilanes, organosiloxanes, fluorosilanes, organic phosphonates, organic phosphoric acid compounds, organic phosphinates, organic sulfonic acid compounds, carboxylic acids, carboxylic acid esters, carboxylic acid derivatives, amides, hydrocarbon waxes, polyolefins, polyolefin copolymers, polyols, polyol derivatives, alkanolamines, alkanolamine derivatives, and organic dispersants. The organic matter preferably contains polyols, organic silanes, etc., and more preferably contains at least one of polyols or organic silanes.

[0084] Specific examples of organic silanes include octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, tridecyltriethoxysilane, tetradecyltriethoxysilane, pentadecyltriethoxysilane, hexadecyltriethoxysilane, heptadecyltriethoxysilane, and octadecyltriethoxysilane.

[0085] Specific examples of organosiloxanes include polydimethylsiloxanes (PDMS) terminated with a trimethylsilyl group, polymethylhydrosiloxanes (PMHS), and polysiloxanes derived from the functionalization of PMHS with olefins (by hydrosilylation).

[0086] Specific examples of organic phosphonates include, for example, n-octylphosphonic acid and its esters, n-decylphosphonic acid and its esters, 2-ethylhexylphosphonic acid and its esters, and campholic phosphonic acid and its esters. Specific examples of organophosphate compounds include organic acid phosphates, organic pyrophosphates, organic polyphosphates, organic metaphosphates, and their salts.

[0087] Specific examples of organic phosphinates include, for example, n-hexylphosphinic acid and its esters, n-octylphosphinic acid and its esters, di-n-hexylphosphinic acid and its esters, and di-n-octylphosphinic acid and its esters. Specific examples of organic sulfonic acid compounds include alkyl sulfonic acids such as hexyl sulfonic acid, octyl sulfonic acid, and 2-ethylhexyl sulfonic acid, as well as salts of these alkyl sulfonic acids with metal ions such as sodium, calcium, magnesium, aluminum, and titanium, ammonium ions, and organic ammonium ions such as triethanolamine.

[0088] Specific examples of carboxylic acids include maleic acid, malonic acid, fumaric acid, benzoic acid, phthalic acid, stearic acid, oleic acid, and linoleic acid. Specific examples of carboxylic acid esters include esters and partial esters produced by the reaction of the above carboxylic acids with hydroxy compounds such as ethylene glycol, propylene glycol, trimethylolpropane, diethanolamine, triethanolamine, glycerol, hexanetriol, erythritol, mannitol, sorbitol, pentaerythritol, bisphenol A, hydroquinone, and phloroglucinol. Specific examples of amides include stearic acid amide, oleic acid amide, and erucic acid amide.

[0089] Specific examples of polyolefins and their copolymers include polyethylene, polypropylene, copolymers of ethylene with one or more compounds selected from propylene, butylene, vinyl acetate, acrylate, acrylamide, etc. Specific examples of polyols include glycerol, trimethylolethane, trimethylolpropane, etc. Specific examples of alkanolamines include diethanolamine, triethanolamine, etc. Specific examples of organic dispersants include citric acid, polyacrylic acid, polymethacrylic acid, polymeric organic dispersants having functional groups such as anionic, cationic, zwitterionic, and nonionic. When aggregation of light diffusing materials in a curable composition is suppressed, the dispersibility of light diffusing materials in the cured product tends to improve.

[0090] The light diffusing material may have a metal oxide layer containing a metal oxide on at least a portion of its surface. Examples of metal oxides included in the metal oxide layer include silicon dioxide, aluminum oxide, zirconia, phosphoria, and boria. The metal oxide layer may be a single layer or two or more layers. When the light diffusing material has two metal oxide layers, it is preferable that it includes a first metal oxide layer containing silicon dioxide and a second metal oxide layer containing aluminum oxide. The presence of a metal oxide layer in the light diffusing material tends to improve the dispersibility of the light diffusing material in the cured product.

[0091] When a light diffusing material has an organic layer containing organic matter and a metal oxide layer, the surface of the light diffusing material may be arranged in the order of the metal oxide layer and the organic layer, that is, with the organic layer as the outer layer. Also, when a light diffusing material has an organic layer and two metal oxide layers, the surface of the light diffusing material may be arranged in the order of a first metal oxide layer containing silicon dioxide, a second metal oxide layer containing aluminum oxide, and the organic layer.

[0092] When the curable composition contains a light diffusing material, the content of the light diffusing material in the wavelength conversion layer formed by curing it may be, for example, 0.1% by mass or more and 1.0% by mass or less, preferably 0.2% by mass or more or 0.3% by mass or more, and 1.0% by mass or less, relative to the total amount of the wavelength conversion layer.

[0093] The curable composition may contain a liquid medium. A liquid medium is a medium that is in a liquid state at room temperature (25°C). Examples of liquid media include ketone solvents, ether solvents, carbonate solvents, ester solvents, aprotic polar solvents, alcohol solvents, glycol monoether solvents, aromatic hydrocarbon solvents, terpene solvents, saturated aliphatic monocarboxylic acids, and unsaturated aliphatic monocarboxylic acids. The curable composition may contain one type of liquid medium alone, or it may contain two or more types of liquid media.

[0094] If the curable composition contains a liquid medium, the content of the liquid medium in the curable composition may be, for example, 1% by mass or more and 10% by mass or less, preferably 4% by mass or more and 10% by mass or 4% by mass or more and 7% by mass or less, based on the total amount of the photocurable composition. In one embodiment, the curable composition may not contain a liquid medium.

[0095] The curable composition may contain a polymerization inhibitor. Including a polymerization inhibitor suppresses viscosity changes during storage of the curable composition and inhibits the formation of polymer impurities while maintaining high curing sensitivity. Examples of polymerization inhibitors include hydroquinone, p-methoxyphenol, di-tert-butyl-p-cresol, pyrogallol, tert-butylcatechol, benzoquinone, 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), N-nitrosophenylhydroxyamine cerium salt, phenothiazine, phenoxazine, 4-methoxynaphthol, 2,2,6,6-tetramethylpiperidine-1-oxyl free radical, 2,2,6,6-tetramethylpiperidine, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical, nitrobenzene, and dimethylaniline. The polymerization inhibitor may preferably include at least one selected from the group consisting of p-benzoquinone, 2,2,6,6-tetramethylpiperidine-1-oxyl free radical, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical, and phenothiazine.

[0096] If the curable composition contains a polymerization inhibitor, the content of the polymerization inhibitor may be, for example, 0.001% by mass or more and 1% by mass or less, preferably 0.005% by mass or more, or 0.008% by mass or more, or 0.5% by mass or less, or 0.05% by mass or less, based on the total amount of polymerizable compounds.

[0097] The curable composition may optionally contain other components such as silane coupling agents, surfactants, adhesion promoters, and antioxidants. The curable composition may contain one of each of these other components alone, or two or more.

[0098] The curable composition can be prepared, for example, by mixing quantum dots, a polymerizable compound containing a primary (meth)acrylate, a thiol compound, and the aforementioned components selected as needed, by conventional methods. The quantum dots may be mixed, for example, in the form of a quantum dot dispersion dispersed in a liquid medium with a monofunctional (meth)acrylate compound having an alicyclic group.

[0099] The wavelength conversion layer can be formed by curing a curable composition containing quantum dots. The wavelength conversion layer can also be formed by molding the curable composition, for example, into a film, and curing the curable composition by irradiating it with active energy rays (e.g., light) to polymerize the polymerizable compound. The wavelength and amount of active energy rays irradiated when forming the wavelength conversion layer can be appropriately set according to the composition of the curable composition. In one embodiment, ultraviolet light with a wavelength of 280 nm to 400 nm is irradiated at 100 mJ / cm². 2 More than 5000mJ / cm 2 The following irradiation doses are permitted. Examples of ultraviolet sources include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, and ultraviolet light-emitting diodes (UV-LEDs).

[0100] The wavelength conversion layer may be formed in the form of a film, sheet, or the like, having two opposing main surfaces and an end surface surrounding the outer edges of the main surfaces. When the wavelength conversion layer is in the form of a film or sheet, the average thickness of the wavelength conversion layer corresponding to the height of the end surface may be, for example, 30 μm or more and 200 μm or less, preferably 30 μm or more and 150 μm or less, or 80 μm or more and 120 μm or less. When the average thickness is 30 μm or more, the wavelength conversion efficiency tends to improve further, and when the average thickness is 200 μm or less, when the wavelength conversion member is applied to a backlight unit, the backlight unit tends to become thinner. The average thickness of the film-like cured material can be determined, for example, as the arithmetic mean of the thicknesses of any three arbitrary locations measured using a reflectance spectrophotometer or the like.

[0101] The wavelength conversion layer may have a glass transition temperature (Tg) of, for example, 50°C to 100°C, preferably 55°C or higher, or 60°C or higher, and 95°C or lower, or 90°C or lower. When the glass transition temperature (Tg) is within the above range, the reliability as a wavelength conversion member tends to improve. The glass transition temperature (Tg) of the wavelength conversion layer can be measured using a dynamic viscoelasticity measuring device (for example, Hitachi High-Tech Corporation: DMS6100) under conditions of a frequency of 1 Hz.

[0102] In addition to the wavelength conversion layer described above, the wavelength conversion member may further include barrier layers laminated on one main surface and the other main surface of the wavelength conversion layer, respectively. The barrier layer can be a barrier film having an inorganic layer. Having an inorganic layer in the barrier layer can more effectively suppress the decrease in the luminescence efficiency of the quantum dots.

[0103] A wavelength conversion member equipped with a barrier layer can be constructed, for example, by applying a curable composition containing quantum dots between two barrier layers, curing the curable composition by irradiation with active energy rays, and forming a wavelength conversion layer containing quantum dots and cured resin.

[0104] The average thickness of the barrier layer may be, for example, 20 μm or more and 150 μm or less, preferably 20 μm or more, or 25 μm or more, and may be 120 μm or less, or 100 μm or less. When the average thickness is 20 μm or more, the barrier properties and other functions tend to be sufficient, and when the average thickness is 150 μm or less, the decrease in light transmittance tends to be suppressed. The average thickness of the barrier layer can be determined in the same way as the film-like wavelength conversion layer.

[0105] The barrier layer preferably has oxygen barrier properties. The oxygen permeability of the barrier layer is, for example, 0.5 mL / (m³). 2 It may be less than or equal to 24h·atm, preferably 0.3 mL / (m³). 2 (24h·atm) or less, or 0.1 mL / (m³) 2It may be less than or equal to 24h·atm. The oxygen permeability of the barrier layer can be measured using an oxygen permeability measuring device (e.g., MOCON, OX-TRAN) under conditions of a temperature of 23°C and a relative humidity of 65%.

[0106] A barrier film having an inorganic layer constituting the barrier layer may, for example, have a base film and an inorganic layer provided on at least one main surface of the base film. Alternatively, for example, the barrier layer may be a laminated film having two base films and an inorganic layer disposed between the two base films. Examples of constituent materials for the base film include thermoplastic resins such as polyester (e.g., polyethylene terephthalate, polyethylene naphthalate), cellulose triacetate, cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyethersulfone, polysulfone, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyetherketone, polymethyl methacrylate, polycarbonate, and polyurethane. Preferably, the constituent materials for the base film are polyester and cellulose triacetate.

[0107] The average thickness of the base film may be, for example, 10 μm or more and 150 μm or less, preferably 20 μm or more, or 125 μm or less. If the average thickness of the base film is 10 μm or more, the occurrence of wrinkles and folds during the assembly and handling of the wavelength conversion member is effectively suppressed. If it is 150 μm or less, it can contribute to the weight reduction and thinning of the image display device.

[0108] The base film may consist of a single film or a laminated film composed of multiple films. Depending on the application, such a laminated film may consist of multiple layers made of films of the same constituent material or multiple layers made of films of different constituent materials.

[0109] The inorganic layer may be a film made of inorganic compounds such as oxides, nitrides, oxynitrides, and carbides. Specifically, examples include metal oxides such as aluminum oxide, magnesium oxide, tantalum oxide, zirconium oxide, titanium oxide, and indium tin oxide (ITO); metal nitrides such as aluminum nitride, metal carbides such as aluminum carbide, silicon oxides such as silicon oxide, silicon oxide nitride, silicon oxide carbide, and silicon oxide nitride carbide; silicon nitrides such as silicon nitride and silicon oxide carbide; silicon carbides such as silicon carbide; and hydrides thereof. The inorganic layer may be composed of one inorganic compound or two or more inorganic compounds.

[0110] The average thickness of the inorganic layer may be, for example, 10 nm to 200 nm, preferably 10 nm to 100 nm, or 15 nm to 75 nm.

[0111] The inorganic layer can be formed by known methods depending on the forming material. Specifically, examples include plasma CVD methods such as CCP-CVD and ICP-CVD, sputtering methods such as magnetron sputtering and reactive sputtering, vacuum deposition, and vapor deposition.

[0112] The wavelength conversion member may include a laminate containing other layers as needed. Examples of other layers include a hard coat layer, an optical compensation layer, a transparent conductive layer, an adhesion-enhancing layer, and an intermediate layer, which will be described later.

[0113] The laminate may include an intermediate layer positioned between the wavelength conversion layer and the barrier layer. The intermediate layer may be made of a material that has good adhesion to both the wavelength conversion layer and the barrier layer. This can suppress the intrusion of moisture and other substances from the boundary between the intermediate layer and the wavelength conversion layer, the boundary between the intermediate layer and the barrier layer, etc. The intermediate layer may contain, for example, a cured resin having a similar structure to the cured resin exemplified in the description of the wavelength conversion layer as the base material.

[0114] The intermediate layer may further contain at least one functional material in addition to the cured resin. Examples of the functional material include a moisture remover (moisture scavenger), an oxygen remover (oxygen scavenger), an antioxidant, etc., and may contain at least one selected from the group consisting of these.

[0115] Examples of the moisture remover include oxides of Group 2 elements such as magnesium oxide and calcium oxide, hydrotalcite, aluminosilicates (e.g., zeolite), silicon oxide (e.g., silica gel), etc. Here, hydrotalcite may be a compound having a composition represented by the following formula (3). [M 3 1-x M 4 x (OH)2] x +[A n- x / n ·mH2O] x- (3)

[0116] In formula (3), M 3 represents divalent metal ions such as Mg 2+ , Mn 2+ , Fe 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , etc. M 4 represents trivalent metal ions such as Fe 3+ , Cr 3+ , Co 3+ , In 3+ , etc. A n- represents an n-valent anion such as OH - , F - , Cl - , Br - , NO3 - , CO3 2- , SO4 2- , Fe(CN)6 3- , CH3COO - , oxalate ion, salicylate ion, etc. n is an integer from 1 to 3. x satisfies 0 < x ≦ 0.33. m is a positive number.

[0117] Examples of oxygen scavenging agents include ceria-zirconia solid solution (CZ solid solution). Examples of antioxidants include ascorbic acid, catechin, dibutylhydroxytoluene, tocopherol, and butylhydroxyanisole.

[0118] The content of the functional material in the intermediate layer may be, for example, 0.1 parts by mass or more and 20 parts by mass or less per 100 parts by mass of cured resin, preferably 0.1 parts by mass or more and 15 parts by mass or less, or 0.1 parts by mass or more and 2 parts by mass or less. By setting the content of the functional material in the intermediate layer within the above range, it is possible to suppress the intrusion of moisture contained in the outside air, etc., while suppressing the decrease in the luminescence efficiency of the wavelength conversion member caused by the functional material.

[0119] The thickness of the intermediate layer may be, for example, 10 μm or more and 100 μm or less, preferably 20 μm or more, or 30 μm or more, and preferably 70 μm or less, 60 μm or less, or 50 μm or less.

[0120] Light-emitting device The light-emitting device is configured to include the wavelength conversion member and light-emitting element described above. In the light-emitting device, for example, a portion of the light emitted from the light-emitting element is absorbed by quantum dots contained in the wavelength conversion member, causing longer wavelength light to be emitted. The light from the quantum dots and the remainder of the light emitted from the light-emitting element are then mixed, and this mixed light can be used as the light emitted by the light-emitting device.

[0121] Specifically, by using a light-emitting element that emits blue-violet or blue light with a peak wavelength of approximately 400 nm to 490 nm, and using quantum dots that absorb blue light and emit yellow light, a light-emitting device that emits white light can be obtained. Alternatively, a white light-emitting device can also be obtained by using two types of quantum dots: one that absorbs blue light and emits green light, and another that absorbs blue light and emits red light.

[0122] The wavelength conversion member may be in contact with the light-emitting element or may be provided at a distance from the light-emitting element. The wavelength conversion member may be a pellet-shaped member, sheet member, plate-shaped member or rod-shaped member provided at a distance from the light-emitting element, or it may be a member provided in contact with the light-emitting element, for example, a sealing member, a coating member (a member that covers the light-emitting element provided separately from the molded member), or a molded member (for example, a member having a lens shape). Furthermore, if two or more types of quantum dots that emit light at different wavelengths are used in the light-emitting device, the two or more types of quantum dots may be mixed within a single wavelength conversion member, or two or more wavelength conversion members containing only one type of quantum dot may be used in combination. In this case, the two or more types of wavelength conversion members may form a laminated structure or be arranged on a plane as a dot-shaped or stripe-shaped pattern.

[0123] Examples of light-emitting elements include light-emitting diode (LED) chips, which are semiconductor light-emitting elements. The LED chip may have a semiconductor layer made of one or more materials selected from the group consisting of GaN, GaAs, InGaN, AlInGaP, GaP, SiC, and ZnO. Semiconductor light-emitting elements that emit blue-violet light, blue light, or ultraviolet light preferably have a general formula of In X Al Y Ga 1-X-Y It is preferable that the semiconductor layer comprises a GaN-based compound represented by N(0≦X, 0≦Y, X+Y<1).

[0124] The light-emitting device is used, for example, as a backlight unit for an image display device. The backlight unit may be an edge-lit type or a direct-lit type. One embodiment of the light-emitting device is one that emits blue light having an emission peak wavelength in the wavelength range of 430 nm to 480 nm, green light having an emission peak wavelength in the wavelength range of 475 nm to 560 nm, and red light having an emission peak wavelength in the wavelength range of 600 nm to 680 nm. The full width at half maximum of each emission peak of the blue light, green light, and red light may be, for example, 100 nm or less, and preferably 80 nm or less, 50 nm or less, 40 nm or less, 30 nm or less, or 25 nm or less.

[0125] Image display device The image display device includes the light-emitting device described above. The image display device may be, for example, a liquid crystal display device. The liquid crystal display device may include, for example, a light-emitting device that includes a sheet-shaped wavelength conversion member and a liquid crystal cell unit that is positioned opposite the light-emitting device. The liquid crystal cell unit may have a configuration in which a liquid crystal cell is positioned between a first polarizing plate and a second polarizing plate.

[0126] The invention relating to this disclosure may encompass, for example, the following embodiments: [1] A wavelength conversion member comprising a wavelength conversion layer containing quantum dots, wherein the wavelength conversion layer is a cured product of a curable composition containing the quantum dots, a first (meth)acrylate containing four or more functional (meth)acrylic groups, and a thiol compound, the glass transition temperature being 50°C or more and 100°C or less, and the molar ratio of the total content of (meth)acrylic groups to the total content of thiol groups of the curable composition being 1.50 or more and 3.00 or less.

[0127] [2] The wavelength conversion member according to [1], wherein the first (meth)acrylate comprises dipentaerythritol hexaacrylate.

[0128] [3] The wavelength conversion member according to [1] or [2], wherein the thiol compound comprises at least one of tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate and pentaerythritol tetrakis(3-mercaptopropionate).

[0129] [4] The wavelength conversion member according to any one of [1] to [3], further comprising a barrier layer laminated on one main surface and the other main surface of the wavelength conversion layer, respectively. [5] A light-emitting device comprising a wavelength conversion member as described in any of [1] to [4] and a light-emitting element. [6] An image display device comprising the light-emitting device described in [5]. [Examples]

[0130] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0131] Reference Example 1: Preparation of Quantum Dots Step 1 (Core-shell synthesis): 5.498 g (24.0 mmol) of silver ethylxanthogenic acid (Ag(EX)), 7.357 g (25.2 mmol) of indium acetate (In(OAc)3), 20.800 g (48.0 mmol) of gallium ethylxanthogenic acid (Ga(EX)3), and 0.634 g (3.6 mmol) of gallium chloride were mixed with 1412 ml of oleylamine (OLA) to obtain the first mixture. The first mixture was heat-treated at 310°C for 120 minutes with stirring under a nitrogen atmosphere. After the resulting suspension was allowed to cool, it was centrifuged (3000 G, 15 minutes), the supernatant was removed, and the precipitate was collected. 704 ml of chloroform was added to the precipitate, and it was centrifuged again (3000 G, 15 minutes), the precipitate was removed, and the supernatant was collected. 776 mL of methanol was added to the supernatant, and the mixture was centrifuged (1500 G, 5 minutes). The supernatant was removed and the precipitate was collected. 1412 mL of oleylamine (OLA) was added to the precipitate, and the mixture was stirred under reduced pressure at 120°C and 37 Pa for 30 minutes to remove any residual solvents other than oleylamine, yielding a first semiconductor nanoparticle dispersion.

[0132] Step 2 (First Gallium Chloride Treatment): To the first semiconductor nanoparticle dispersion obtained in Step 1, 5.481 g (72.0 mmol) of thiourea and 12.678 g (72.0 mmol) of gallium chloride were added to obtain the second mixture. The second mixture was heat-treated at 270°C for 120 minutes under a nitrogen atmosphere with stirring. After the resulting suspension was allowed to cool, it was centrifuged (3000 G, 5 minutes), the supernatant was discarded, and the precipitate was collected. 1412 ml of oleylamine (OLA) was added to the precipitate and dispersed to obtain the second semiconductor nanoparticle dispersion.

[0133] Third step (thickening): 29.120 g (67.2 mmol) of gallium ethylxanthogenic acid (Ga(EX)3) was added to the second semiconductor nanoparticle dispersion obtained in the second step to obtain the third mixture. The third mixture was heat-treated at 270°C for 120 minutes while stirring under a nitrogen atmosphere. After the resulting suspension was allowed to cool, it was collected to obtain the third semiconductor nanoparticle dispersion.

[0134] Step 4 (Gallium Chloride Treatment II): 21.130 g (120 mmol) of gallium chloride was added to the third semiconductor nanoparticle dispersion obtained in Step 3 to obtain the fourth mixture. The fourth mixture was heat-treated at 260°C for 240 minutes while stirring under a nitrogen atmosphere. After the resulting suspension was allowed to cool, it was centrifuged (3000 G, 15 minutes), the supernatant was removed, and the precipitate was collected. 696 ml of ethyl acetate was added to the precipitate, and it was centrifuged (3000 G, 15 minutes). The supernatant was discarded, and the precipitate was collected. Another 696 ml of ethyl acetate was added to the precipitate, and it was centrifuged (3000 G, 15 minutes). The precipitate was collected again. The mass of the precipitate collected at this time was 10.143 g. The precipitate was dispersed in 278 ml (275.62 g) of isobornyl acrylate (IBOA) to obtain the fourth semiconductor nanoparticle dispersion.

[0135] The mass concentration of the fourth semiconductor nanoparticles in the fourth semiconductor nanoparticle dispersion was calculated to be 3.55% by mass using the following formula. 10.143÷(10.143+275.62)×100=3.55(mass%)

[0136] Luminescence characteristics evaluation The luminescence properties of the fourth nanoparticle semiconductor dispersion were measured. The fourth nanoparticle semiconductor dispersion was diluted with chloromolum until the absorbance at 450 nm was 0.15 using a spectrophotometer (U-2900, Hitachi) to obtain a diluted fourth nanoparticle semiconductor dispersion. Using a quantum efficiency analyzer (QE-2100, Otsuka Electronics Co., Ltd.), excitation light with an emission peak wavelength of 450 nm was irradiated onto the diluted fourth nanoparticle semiconductor dispersion, and the emission spectrum at room temperature (25°C) was measured. From the obtained emission spectrum, the internal quantum efficiency (%), emission peak wavelength (nm), and full width at half maximum (nm) of the emission spectrum with the emission peak wavelength were determined. The emission spectrum is shown in Figure 1, and the measurement results are shown in Table 1.

[0137] [Table 1]

[0138] The following materials were prepared to make the curable composition. polymerizable compound Tricyclodecanedimethanol acrylate (bifunctional acrylate; A-DCP; manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) • Trimethylolpropane trimethacrylate (trifunctional acrylate; TMP™; manufactured by Tokyo Chemical Industry Co., Ltd.) • Dipentaerythritol hexaacrylate (hexafunctional acrylate; DPHA; manufactured by Tokyo Chemical Industry Co., Ltd.) Thiol compounds Tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate (TEMPIC; manufactured by Sakai Chemical Industry Co., Ltd.) Photopolymerization initiator • Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO; manufactured by Fujifilm Wako Pure Chemical Corporation)

[0139] Example 1 0.515 g (1.69 mmol) of tricyclodecanedimethanol acrylate (A-DCP), 0.129 g (0.22 mmol) of dipentaerythritol hexaacrylate (DPHA), and 0.010 g (0.03 mmol) of diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide (TPO) were mixed and stirred until the TPO was completely dissolved to prepare an acrylic monomer mixture. Next, 0.347 g (0.66 mmol) of tris[2-(3-mercaptopropionyloxy)ethyl isocyanurate (TEMPIC) and 0.150 g of a 4 nanoparticle semiconductor dispersion were added to the acrylic monomer mixture and stirred using a rotation-orbit mixer (MAZERUSTAR: Kurabo Industries Ltd.) to prepare a curable composition. The composition of the curable composition is shown in Table 2. Note that the molar ratio of acrylic groups to thiol groups in Table 2 was calculated by considering the number of moles of the fourth semiconductor nanoparticle dispersion as the number of moles of isobornyl acrylate.

[0140] Two barrier layers were prepared: a barrier film (TBF1004: manufactured by i-components). A curable composition was applied between the two barrier layers using a roll-to-roll coating machine, and then irradiated with a UV-LED light source with a main wavelength of 385 nm at an irradiance of 80.8 mW / cm². 2 The wavelength conversion member of Example 1 was fabricated by irradiating it with UV light for 225 seconds to initiate the monomer polymerization reaction and cure it, thereby adhering a barrier film to both main surfaces of a 50 μm thick wavelength conversion layer.

[0141] Examples 2 to 3 and Comparative Example 1 The curable composition was prepared in the same manner as in Example 1, except that the composition of the curable composition was changed as shown in Table 2, and the wavelength conversion members of Examples 2 to 3 and Comparative Example 1 were fabricated.

[0142] Comparative Examples 2 to 4 A curable composition was prepared without using dipentaerythritol hexaacrylate (DPHA). Specifically, the wavelength conversion members of Comparative Examples 2 to 4 were fabricated by preparing the curable composition in the same manner as in Example 1, except that the composition of the curable composition was changed as shown in Table 2.

[0143] Comparative Examples 5 to 7 A curable composition was prepared using trimethylolpropane trimethacrylate (trifunctional acrylate TMP™) instead of dipentaerythritol hexaacrylate (DPHA). Specifically, the curable composition was prepared in the same manner as in Example 1, except that the composition of the curable composition was changed as shown in Table 2, and the wavelength conversion members of Comparative Examples 5 to 7 were fabricated.

[0144] [Table 2]

[0145] Preparation of samples for evaluating glass transition temperature As the release film, PET film (Lumirror 40.01: manufactured by Toray Industries, Inc.) was prepared. Using a roll-to-roll coating machine, a curable composition was applied between two release films to a thickness of 50 μm, and then an illuminance of 80.8 mW / cm² was applied using a UV-LED light source with a main wavelength of 385 nm. 2 The material was irradiated with UV light for 225 seconds to initiate the polymerization reaction of the monomers and allow it to cure. After curing, both release films were peeled off to extract only the wavelength conversion layer, which was used as a sample for evaluating the glass transition temperature.

[0146] Glass transition temperature evaluation The glass transition temperature (Tg) of samples prepared using the curable compositions of the examples and comparative examples was evaluated using a dynamic viscoelasticity analyzer (DMS6100: Hitachi High-Tech Corporation). The temperature was increased from 30°C to 200°C at a rate of 2°C / min while applying a frequency of 1 Hz. The glass transition temperature (Tg) of the sample was calculated as the temperature at which the loss tangent (tanδ), which is the ratio of the loss modulus E'' to the storage modulus E', reached its maximum value. The results are shown in Table 2.

[0147] Reliability evaluation (brightness maintenance rate) The reliability of the wavelength conversion members fabricated in the examples and comparative examples was evaluated as follows: Emission peak wavelength of 450 nm, illuminance of 36 mW / cm². 2 A wavelength conversion component was placed on a backlight source to create an evaluation light-emitting device. The fabricated evaluation light-emitting device was continuously lit for 1000 hours in a constant temperature and humidity chamber (manufactured by ESPEC Corporation) at a temperature of 60°C and a relative humidity of 90%. The brightness maintenance rate (%) of the wavelength conversion component after 1000 hours was calculated as a ratio to the initial brightness. The results are shown in Table 2. To measure the brightness of the wavelength conversion component, the wavelength conversion component was placed on a backlight source with an emission peak wavelength of 450 nm, and a prism sheet and a deflection sheet were stacked to form a light-emitting device. The brightness of the light-emitting device at room temperature (25°C) was measured using a spectrophotometer.

Claims

1. Equipped with a wavelength conversion layer containing quantum dots, The wavelength conversion layer is a cured product of a curable composition comprising the quantum dots, a first (meth)acrylate containing four or more (meth)acrylic groups, and a thiol compound, wherein the glass transition temperature is 50°C or higher and 100°C or lower. The curable composition is a wavelength conversion member in which the molar ratio of the total content of (meth)acrylic groups to the total content of thiol groups is 1.50 or more and 3.00 or less.

2. The wavelength conversion member according to claim 1, wherein the first (meth)acrylate comprises dipentaerythritol hexaacrylate.

3. The wavelength conversion member according to claim 1 or 2, wherein the thiol compound comprises at least one of tris[2-(3-mercaptopropionyloxy)ethyl] isocyanurate and pentaerythritol tetrakis(3-mercaptopropionate).

4. The wavelength conversion member according to claim 1 or 2, further comprising a barrier layer laminated on one main surface and the other main surface of the wavelength conversion layer, respectively.

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