JP7039842B2 - Image display device - Google Patents

Description

The present invention relates to an image display device.

In recent years, a liquid crystal display device has been mainly used as an image display device. In the liquid crystal display device, the light emitted from the backlight device is displayed as an image by using the shutter function of the liquid crystal cell.

Currently, in order to improve color reproducibility, it is being considered to incorporate quantum dots into an image display device. Quantum dots absorb light (primary light) and emit light of different wavelengths (secondary light). The wavelength of the light emitted by the quantum dots mainly depends on the particle size of the quantum dots. Therefore, if quantum dots are used, various colors can be reproduced while using a light source that projects light in a single wavelength range. For example, when a light source that emits blue light is used, the quantum dots can also absorb the blue light and emit green light and red light.

When incorporating quantum dots into an image display device, the quantum dots are often incorporated into a backlight device (see Patent Document 1). The methods for incorporating quantum dots into a backlight device include an on-chip method in which quantum dots are incorporated in a light source, an on-edge method in which a glass tube containing quantum dots is placed between the light source and the light guide plate, and the light emitting side of the light guide plate. An on-surface method is known in which a sheet containing quantum dots is placed on the surface.

Japanese Unexamined Patent Publication No. 2013-218953

Currently, it is being studied to simplify the structure of an image display device using quantum dots, but when incorporating quantum dots into a backlight device, it is a prerequisite to use a liquid crystal cell that provides a shutter function. Therefore, it is practically difficult to display an image without using a liquid crystal cell.

The present invention has been made to solve the above problems. That is, it is an object of the present invention to provide an image display device using quantum dots, which can simplify the structure.

As a result of diligent research on the above-mentioned problems, the present inventors arranged a light emitting element for each sub-pixel and arranged an optical wavelength conversion layer containing quantum dots at a position corresponding to the light emitting element to emit light. It has been found that by performing the shutter function by turning the element on / off, it is possible to display an image without using a liquid crystal cell. The present invention has been completed based on such findings.

According to one aspect of the present invention, a light source including one or more light emitting elements, a light shielding layer arranged on the observer side of the light emitting element and having an opening at a position corresponding to the light emitting element, and the opening. Light that is arranged inside and contains a light wavelength conversion particle and a binder resin, and light that is arranged in the opening and on the observer side of the light wavelength conversion layer and is wavelength-converted by the light wavelength conversion particles. At least one element and a carboxylic acid selected from the group consisting of sulfur, phosphorus, and nitrogen, comprising a colored layer that transmits light and absorbs light from the light emitting element. A first light wavelength conversion particle containing a light-transmitting resin particle containing any of the above, a quantum dot contained in the resin particle, a light-transmitting barrier particle, and a quantum dot contained in the barrier particle. An image display device, which is at least one of the second light wavelength conversion particles including the above, is provided.

In the image display device, the first light wavelength conversion particle may further include a barrier layer covering the surface of the resin particle.

In the image display device, the barrier particles may be inorganic oxide particles.

In the image display device, the light source further includes one or more packages having recesses, the light emitting element is arranged in the recesses, and the distance from the light-shielding layer to the portion of the package corresponding to the light-shielding layer. May be 10 μm or less.

According to another aspect of the present invention, a light source having a package having a recess and a light emitting element arranged in the recess, and a position arranged on the observer side of the light emitting element and corresponding to the light emitting element. A light-shielding layer having an opening, an optical wavelength conversion layer arranged in the opening and containing quantum dots and a binder resin, and arranged in the opening and closer to the observer than the optical wavelength conversion layer, by the quantum dots. An image in which a colored layer that transmits wavelength-converted light and absorbs light from the light emitting element is provided, and the distance from the light-shielding layer to the portion of the package corresponding to the light-shielding layer is 10 μm or less. A display device is provided.

According to another aspect of the present invention, a light source including one or more light emitting elements, a pair of barrier members arranged so as to face each other on the observer side of the light emitting element, and the barrier members are arranged. A light-shielding layer having an opening at a position corresponding to the light-emitting element, an optical wavelength conversion layer arranged in the opening and containing a quantum dot and a binder resin, and an observer in the opening and more than the optical wavelength conversion layer. An image display device is provided that includes a first colored layer that is arranged on the side, transmits light wavelength-converted by the quantum dots, and absorbs light from the light emitting element.

In the image display device, a second unit provided between the barrier member on the light source side and the light wavelength conversion layer, which transmits light from the light emitting element and absorbs light wavelength-converted by the quantum dots. The colored layer of 2 may be further provided.

According to one aspect and the other aspect of the present invention, it is possible to provide an image display device using quantum dots, which can simplify the structure.

It is a schematic block diagram of the image display device which concerns on 1st Embodiment. It is a schematic block diagram of the light wavelength conversion particle shown in FIG. It is a schematic block diagram of another image display device which concerns on 1st Embodiment. It is a schematic block diagram of the light wavelength conversion particle shown in FIG. It is a schematic block diagram of another image display device which concerns on 1st Embodiment. It is a schematic block diagram of the image display device which concerns on 2nd Embodiment.

[First Embodiment]
Hereinafter, the image display device according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an image display device according to the present embodiment, FIG. 2 is a schematic configuration diagram of the light wavelength conversion particles shown in FIG. 1, and FIGS. It is a schematic block diagram of the image display apparatus of FIG. 4, and FIG. 4 is a schematic block diagram of the light wavelength conversion particles shown in FIG.

<<<<< Image display device >>>>>
The image display device 10 shown in FIG. 1 has a light source 20 including one or more light emitting elements 23, and openings 30A, 30B, 30C arranged on the observer side of the light emitting element 23 and at positions corresponding to the light emitting elements 23. The light-shielding layer 30, the light wavelength conversion layers 40 and 45 arranged in the openings 30A and 30B, the light diffusion layer 50 arranged in the openings 30C, and the light wavelength conversion layers 40 and 45 in the openings 30A and 30B. It includes colored layers 60 and 65 arranged on the observer side, and colored layers 70 arranged in the opening 30C and on the observer side of the light diffusion layer 50. The image display device 10 includes a barrier member 80 and a circularly polarizing plate 90 in this order toward the observer side of the colored layers 60 and 70. The image display device 10 does not have to include the light diffusion layer 50, the colored layer 70, the barrier member 80, and the circularly polarizing plate 90. Further, in the present embodiment, the optical wavelength conversion layers 40 and 45 are used, but either one may be used. Further, the light-shielding layer 30 is provided with openings 30A, 30B, and 30C, and it is sufficient that any one of the openings 30A, 30B exists as the opening. The light source 20 is integrated with the light-shielding layer 30, the light wavelength conversion layers 40, 45, and the like via the light-transmitting adhesive layer 95.

<< Light source >>
The light source 20 includes one or more light emitting element packages 21 and a substrate 22 on which the light emitting element packages 21 are mounted. The light emitting element package 21 is arranged for each sub-pixel. The sub-pixel is, for example, each display portion corresponding to red, green, and blue when color display is performed in red, green, and blue. In this case, the red sub-pixel, the green sub-pixel, and the blue are used. It becomes one pixel with three sub-pixels as a unit. The light emitting element package 21 includes a light emitting element 23 and a package 24 having a recess 24A.

<Light emitting element>
Examples of the light emitting element 23 include a light emitting diode element (LED element), a laser diode element (LD element), and the like. As the light emitting element, a light emitting element that emits light in a single wavelength range can be used. In the present embodiment, the light emitting element 23 is a blue light emitting diode (blue LED) that emits blue light.

<Package>
The package 24 has a recess 24A, and the light emitting element 23 is arranged in the recess 24A. The package 24 includes a package body 24B, an electrode layer 24C, and a wire 24D. The light emitting element 24 is electrically connected to the electrode layer 24C via the wire 24D.

<< Shading layer >>
The light-shielding layer 30 is also called a black matrix layer that is divided into sub-pixels. The light-shielding layer 30 contains a black color material and a binder resin. The light-shielding layer 30 is provided on the surface of the barrier member 80 on the light source 20 side and extends toward the light source 20 side. The light-shielding layer 30 is formed in a grid pattern. As used herein, the term "lattice" means a structure in which a plurality of openings are arranged in a matrix in a plan view of a light-shielding layer. Examples of the shape of the opening in the plan view of the light-shielding layer include a polygonal shape such as a quadrangular shape, an elliptical shape, and a circular shape. Examples of the square shape include a square shape and a rectangular shape.

The film thickness of the light-shielding layer 30 is preferably 1 μm or more and 100 μm or less. When the film thickness of the light-shielding layer 30 is 1 μm or more, color mixing with adjacent sub-pixels can be suppressed, and when it is 100 μm or less, it becomes easy to form a fine pattern. The film thickness of the light-shielding layer 30 is determined by photographing a cross section of the light-shielding layer 30 using a scanning electron microscope (SEM), measuring the film thickness of the light-shielding layer 30 at 20 points in the image of the cross section, and measuring the film thickness at 20 points. The average value of the thickness. The lower limit of the film thickness of the light-shielding layer 30 is more preferably 2 μm or more, and the upper limit is more preferably 20 μm or less.

The distance d from the light-shielding layer 30 to the portion of the package 24 corresponding to the light-shielding layer 30 shown in FIG. 1 is preferably 10 μm or less. When this distance d is 10 μm or less, the light wavelength-converted by the quantum dots 41A and 46A, which will be described later, can be suppressed from entering other sub-pixels, so that color mixing can be suppressed. The distance d is more preferably 0 μm. When the distance d is 0 μm, the light-shielding layer 30 is in contact with the package 24. In this embodiment, the light wavelength conversion particles 41 and 46 are used, but when the distance from the light shielding layer to the package portion corresponding to the light shielding layer is 10 μm or less, the light wavelength conversion layer is used. It suffices to contain quantum dots and binder resin, and it is not always necessary to use light wavelength conversion particles.

<Black color material>
Examples of the black color material include those generally used for the light-shielding layer 30 of the color filter, and both pigments and dyes can be used. For example, carbon black, titanium black and the like can be mentioned. The content of the black color material in the light-shielding layer may be the same as that of a general light-shielding layer in a color filter, as long as a desired light-shielding property can be obtained.

<Binder resin>
The binder resin is appropriately selected depending on the method for forming the light-shielding layer 30. In the case of the photolithography method, as the binder resin, for example, a photosensitive resin having a reactive vinyl group such as an acrylate-based resin, a methacrylate-based resin, a polyvinyl chloride-based resin, or a cyclized rubber-based resin is used. In the case of the printing method or the inkjet method, the binder resin includes, for example, polymethylmethacrylate resin, polyacrylate resin, polycarbonate resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, hydroxyethyl cellulose resin, carboxymethyl cellulose resin, polyvinyl chloride resin, and melamine. Examples thereof include resins, phenol resins, alkyd resins, epoxy resins, polyurethane resins, polyester resins, maleic acid resins, polyamide resins and the like.

<< Optical wavelength conversion layer >>
The optical wavelength conversion layers 40 and 45 have a function of converting the wavelength of incident light into another wavelength. In the present embodiment, the light wavelength conversion layer 40 has a function of converting blue light into green light, and the light wavelength conversion layer 45 has a function of converting blue light into red light. The light wavelength conversion layer 40 includes the light wavelength conversion particles 41 and the binder resin 42, and the light wavelength conversion layer 45 contains the light wavelength conversion particles 46 and the binder resin 47. The light wavelength conversion layers 40 and 45 may include light wavelength conversion particles 41 and 46, binder resins 42 and 47, and light scattering particles.

The film thicknesses of the optical wavelength conversion layers 40 and 45 are preferably 1 μm or more and 50 μm or less, respectively. When the film thicknesses of the optical wavelength conversion layers 40 and 45 are 1 μm or more, sufficient optical wavelength conversion efficiency can be obtained, and when the film thickness is 50 μm or less, the image display device is suitable for thinning. The film thicknesses of the optical wavelength conversion layers 40 and 45 can be measured by the same method as the film thickness of the light shielding layer 30. The lower limit of the optical wavelength conversion layers 40 and 45 is more preferably 2 μm or more, and the upper limit is more preferably 20 μm or less.

<Light wavelength conversion particles>
As shown in FIGS. 2 (A) and 2 (B), the optical wavelength conversion particles 41 and 46 are one or more elements selected from the group consisting of sulfur, phosphorus, and nitrogen (hereinafter, this element is referred to as “this element”. It includes resin particles 41B, 46B containing at least one of a specific element) and a carboxylic acid, and one or more quantum dots 41A, 46A contained in the resin particles 41B. The light wavelength conversion particles 41 and 46 shown in FIGS. 2A and 2B further include coating layers 41C and 46C covering the surfaces of the resin particles 41B and 46B. The optical wavelength conversion particles 41 and 46 may not include the coating layers 41C and 46C as long as they include the quantum dots 41A and 46A and the resin particles 41B and 46B.

In the light wavelength conversion particles 41 and 46, the content of the specific element in the light wavelength conversion particles 41 and 46 measured by fluorescent X-ray analysis (XRF) is 0.5% by mass or more. preferable. When the content of the specific element is 0.5% by mass or more, the deterioration of the quantum dots 41A and 46A can be further suppressed. The content of a specific element can be measured by using a fluorescent X-ray analyzer (product name "EDX-800HS", manufactured by Shimadzu Corporation). The content of the specific element shall be the average value of the values obtained by measuring three times. The lower limit of the content of the specific element in the light wavelength conversion particles 41 and 46 measured by fluorescent X-ray analysis (XRF) is more preferably 1% by mass or more, and the upper limit of the content of the specific element is. It is more preferably 20% by mass or less, and further preferably 10% by mass or less. When the content of the specific element is 20% by mass or less, sufficient curing can be performed at the time of forming the light wavelength conversion particles. When the light wavelength conversion particles contain two or more specific elements, the above-mentioned content means the total content of the specific elements.

The average particle size of the optical wavelength conversion particles 41 and 46 is preferably twice or more the average particle size of the quantum dots 41A and 46A. When the average particle diameter of the optical wavelength conversion particles 41 and 46 is at least twice the average particle diameter of the quantum dots 41A and 46A, the distance from the quantum dots 41A and 46A to the surface of the optical wavelength conversion particles 41 and 46 is determined. Since it can be sufficiently secured, deterioration of the quantum dots 41A and 46A due to moisture and oxygen can be further suppressed. The average particle size of the light wavelength conversion particles 41 and 46 is determined by measuring the particle size of 20 light wavelength conversion particles in the observation of the light wavelength conversion particles by a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). It can be obtained by calculating the average value. Further, for the average particle diameter of the quantum dots 41A and 46A, the particle diameter of 20 quantum dots is measured by observing the cross section of the optical wavelength conversion particle with a transmission electron microscope or a scanning transmission electron microscope, and the average value thereof is calculated. Can be found at.

The average particle diameter of the light wavelength conversion particles 41 and 46 is preferably 10 nm or more and 100 μm or less. If the average particle size of the light wavelength conversion particles is 10 nm or more, the deterioration of the quantum dots can be further suppressed, and if it is 100 μm or less, there is no deterioration in dispersibility or defects in processing the light wavelength conversion member. .. The lower limit of the average particle size of the light wavelength conversion particles 41 and 46 is preferably 20 nm or more, and the upper limit of the average particle size of the light wavelength conversion particles 41 and 46 is preferably 30 μm or less and 10 μm or less. Is more preferable.

The shapes of the optical wavelength conversion particles 41 and 46 are not particularly limited, and are, for example, spherical (true spherical, substantially true spherical, elliptical spherical, etc.), polyhedral, rod-shaped (cylindrical, prismatic, etc.), flat plate-shaped, and flaky. , Indefinite shape and the like. When the shape of the light wavelength conversion particles 1 is not spherical, the particle diameters of the light wavelength conversion particles 41 and 46 can be set to a true spherical value having the same volume.

It is preferable that each of the optical wavelength conversion particles 41 and 46 contains one or more quantum dots 41A and 46A. If the number of quantum dots contained in one optical wavelength conversion particle is one or more, the brightness does not decrease. The number of quantum dots contained in one optical wavelength conversion particle is 100,000 to 500,000 times the cross section of 20 optical wavelength conversion particles at random using a transmission electron microscope or a scanning transmission electron microscope. The number of quantum dots contained in one light wavelength conversion particle is calculated from the obtained cross-sectional image, and the average value of the calculated number of quantum dots is calculated.

Each of the optical wavelength conversion particles 41, 46 contains two or more quantum dots 41A, 46A, and the quantum dots 41A in the quantum dots 41A, 46A included in one optical wavelength conversion particle 41, 46, The average distance between 46A is preferably 1 nm or more. If the average distance between the quantum dots is 1 nm or more, there is no possibility that the luminous efficiency will decrease due to the concentration quenching that causes quenching due to the energy transfer between the quantum dots. The average distance between the quantum dots is the cross section obtained by randomly photographing the cross section of 20 light wavelength conversion particles with a transmission electron microscope or a scanning transmission electron microscope at a magnification of 100,000 to 500,000 times. The distance between the quantum dots is calculated from the image of, and the average value of the calculated distances between the quantum dots is calculated. It is more preferable that the upper limit of the average distance between the quantum dots 41A and 46A is 100 nm or less.

<Quantum dots>
The quantum dots 41A and 46A are nano-sized semiconductor particles having a quantum confinement effect. The particle diameter and the average particle diameter of the quantum dots 41A and 46A are, for example, 1 nm or more and 20 nm or less. When the quantum dots 41A and 46A absorb light from the excitation source and reach an energy excited state, they emit energy corresponding to the energy band gap of the quantum dots 41A and 46A. Therefore, by adjusting the particle size or the composition of the substance of the quantum dots 41A and 46A, the energy band gap can be adjusted, and energy in various levels of wavelength bands can be obtained. In particular, the quantum dots 41A and 46A can generate strong fluorescence in a narrow wavelength band.

Specifically, the energy band gap of quantum dots increases as the particle size decreases. That is, as the crystal size becomes smaller, the emission of the quantum dots 41A and 46A shifts to the blue side, that is, to the high energy side. Therefore, by changing the particle diameters of the quantum dots 41A and 46A, the emission wavelength can be adjusted over the entire wavelength of the spectrum in the ultraviolet region, the visible region, and the infrared region. For example, when the quantum dot is composed of CdSe / ZnS described later, blue light is emitted when the particle diameter of the quantum dot is 2.0 nm or more and 4.0 nm or less, and the particle diameter of the quantum dot is 3.0 nm. When the particle size is 6.0 nm or less, green light is emitted, and when the particle size of the quantum dots is 4.5 nm or more and 10.0 nm or less, red light is emitted. As used herein, "blue light" is light having a wavelength range of 380 nm or more and less than 480 nm, "green light" is light having a wavelength range of 480 nm or more and less than 590 nm, and "red light" is Light having a wavelength range of 590 nm or more and 750 nm or less. Further, the light intensity of each of the above lights can be measured using a spectral radiance meter (for example, product name "CS2000", manufactured by Konica Minolta Co., Ltd.). In the above, the range of the particle size of the quantum dot emitting blue light and the particle size of the quantum dot emitting green light partially overlaps, and the particle size of the quantum dot emitting green light and the red light are overlapped. The range of the particle size of the emitted quantum dots overlaps in part, but even if the quantum dots have the same particle size, the emission color may differ depending on the size of the core of the quantum dots, so there is no contradiction. It's not something to do.

The quantum dots 41A and 46A can generate strong fluorescence in a desired narrow wavelength range. Therefore, the backlight device using the light wavelength conversion sheet can illuminate the display panel with the light of the three primary colors having excellent color purity. In this case, the display panel will have excellent color reproducibility. In the present embodiment, the quantum dot 41A converts blue light into green light, and the quantum dot 46A converts blue light into red light.

The quantum dots 41A and 46A are, for example, a core made of a first semiconductor compound, a shell made of a second semiconductor compound that covers the core and is different from the first semiconductor compound, and a ligand bonded to the surface of the shell. It is composed of and.

Examples of the first semiconductor compound constituting the core include MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, and the like. II-VI semiconductor compounds such as HgS, HgSe and HgTe, III such as AlN, AlP, AlAs, AlSb, GaAs, GaP, GaN, GaSb, InN, InAs, InP, InSb, TiN, TiP, TiAs and TiSb. Examples thereof include semiconductor compounds such as group V semiconductor compounds, group IV semiconductors such as Si, Ge and Pb, or semiconductor crystals containing semiconductors. Further, a semiconductor crystal containing a semiconductor compound containing three or more elements such as InGaP can also be used. Among these, semiconductor crystals such as CdS, CdSe, CdTe, InP, and InGaP are preferable from the viewpoints of ease of production, controllability of particle size capable of obtaining light emission in the visible range, and the like.

As the second semiconductor compound constituting the shell, it is preferable to use a semiconductor compound having a bandgap higher than that of the first semiconductor compound constituting the core so that excitons are confined in the core. This makes it possible to increase the luminous efficiency of the quantum dots. Examples of the second semiconductor compound constituting the shell include ZnS, ZnSe, CdS, GaN, CdSSe, ZnSeTe, AlP, ZnSTe, ZnSSe and the like.

Specific combinations of the core-shell structure (core / shell) consisting of the core and the shell include, for example, CdSe / ZnS, CdSe / ZnSe, CdSe / CdS, CdTe / CdS, InP / ZnS, Gap / ZnS, Si / ZnS, and the like. InN / GaN, InP / CdSSe, InP / ZnSeTe, InGaP / ZnSe, InGaP / ZnS, Si / AlP, InP / ZnSTe, InP / ZnSSe, InGaP / ZnSTe, InGaP / ZnSSe and the like can be mentioned.

The ligand is for stabilizing unstable quantum dots. Examples of the ligand include sulfur compounds such as thiol, phosphorus compounds such as phosphine compounds or phosphine oxides, nitrogen compounds such as amines, and carboxyl group-containing compounds.

The shape of the quantum dot is not particularly limited, and may be, for example, a spherical shape, a rod shape, a disk shape, or any other shape. When the shape of the quantum dot is not spherical, the particle diameter of the quantum dot can be a true spherical value having the same volume.

Information such as the particle size, average particle size, shape, and dispersed state of the quantum dots can be obtained by a transmission electron microscope or a scanning transmission electron microscope. Further, since the emission color of the quantum dot changes depending on the particle diameter, it is also possible to obtain the particle diameter of the quantum dot by confirming the emission color of the quantum dot. Further, the crystal structure and crystallite size of the quantum dots can be known by X-ray crystal diffraction (XRD). Furthermore, information on the particle size of quantum dots and the like can be obtained from the ultraviolet-visible (UV-Vis) absorption spectrum.

<Resin particles>
The resin particles 41B and 46B contain at least one of a specific element and a carboxylic acid. The resin particles 41B and 46B may contain two or more specific elements, or may contain both a specific element and a carboxylic acid. The specific element or carboxylic acid does not have to be fixed in the resin particles 41B and 46B, but from the viewpoint of preventing the elution of the specific element and the carboxylic acid, the resin is bonded to the resin constituting the resin particles 41B and 46B. It is preferably fixed in the particles 41B and 46B. When at least one of a specific element and a carboxylic acid is fixed to the resin constituting the resin particles 41B and 46B, a compound containing the specific element (hereinafter, this compound is referred to as a "specific compound") and a carboxylic acid. It is preferred that at least one of the acids has a polymerizable functional group. Examples of the polymerizable functional group include an ethylenically unsaturated group such as a (meth) acryloyl group, a vinyl group and an allyl group, an epoxy group, an isocyanate group, or a hydroxyl group. When at least one of the specific compound and the carboxylic acid contains an isocyanate group as a polymerizable functional group, the polymerizable compound used for forming the resin constituting the resin particles 41B and 46B contains a hydroxyl group, and the specific compound and the specific compound and When at least one of the carboxylic acids contains a hydroxyl group as a polymerizable functional group, the polymerizable compound used for forming the resin constituting the resin particles 41B and 46B preferably contains an isocyanate group. When at least one of the specific compound and the carboxylic acid contains a polymerizable functional group, it is possible to polymerize with the polymerizable compound and fix at least one of the specific element and the carboxylic acid in the resin particles 41B and 46B. .. When at least one of the specific compound and the carboxylic acid contains a polymerizable functional group, at least one of the specific compound and the carboxylic acid may contain one or more polymerizable functional groups, but may contain two or more. good.

Whether or not the resin particles 41B and 46B contain a specific element or carboxylic acid can be confirmed as follows. First, as will be described later, a ligand composed of a sulfur-based compound, a phosphorus-based compound, a nitrogen-based compound, a carboxyl group-containing compound, or the like is bound to the surface of the shell of the quantum dot. Even when an element or carboxylic acid is detected, the detected specific element or carboxylic acid is not necessarily the specific element or carboxylic acid contained in the resin particles. On the other hand, since the ligand of the quantum dot is bound to the surface of the shell and the size of the coordination site of the ligand is usually within about 1 nm, it does not exist at a position 3 nm or more away from the surface of the shell. Therefore, specific elements are detected by X-ray photoelectron spectroscopy (XPS) or energy dispersive X-ray analysis (EDS) at any position on the surface or inside of the resin particles at a distance of 3 nm or more from the surface of the shell of the quantum dots. If carboxylic acid is detected by microinfrared spectroscopic analysis (IR), it can be determined that the resin particles contain a specific element or carboxylic acid.

The resin particles 41B and 46B are particles of a cured product of a mixture containing at least one of a specific element and a carboxylic acid and a polymerizable compound. The specific element is one or more elements selected from the group consisting of sulfur, phosphorus, and nitrogen, but when incorporating a specific element, it is preferable to use a specific compound. Specific compounds include, for example, sulfur-based compounds, phosphorus-based compounds, nitrogen-based compounds, or mixtures thereof.

(Sulfur compound)
The sulfur-based compound is a compound containing sulfur. The sulfur-based compound is not particularly limited, and examples thereof include thiol compounds, thioether compounds, disulfide compounds, and thiophene compounds. When a thiol compound is used as the sulfur compound, it is preferable that the thiol compound and the polymerizable compound form a copolymer by a thiol-ene reaction in the resin particles. By copolymerizing the thiol and the polymerizable compound, the thiol compound can be immobilized in the resin particles. In this embodiment, the thiol compound and the polymerizable compound are separate compounds, but a thiol compound having a thiol group and a radically polymerizable functional group in one molecule may be used. When a thiol compound is used, it is particularly preferable to use a secondary thiol compound or a tertiary thiol compound from the viewpoint of pot life at the time of coating and suppression of odor.

The secondary thiol compound is a compound in which two hydrocarbon groups are bonded to carbon to which a thiol group is bonded. The tertiary thiol compound is a compound in which three hydrocarbon groups are bonded to carbon to which a thiol group is bonded. The secondary thiol compound and the tertiary thiol compound may have one or more thiol groups in one molecule, but are preferably two or more from the viewpoint of improving the heat resistance and moisture heat resistance of the quantum dots.

式中、Ｒ^１は置換されていてもよい炭素原子数１～１０のアルキル基であり、Ｒ^２は置換されていてもよい炭素原子数１～１０のアルキレン基であり、Ｒ^３は炭素原子以外の原子を含んでいてもよい炭素原子数１～１５のｎ価の脂肪族基であり、ｍは１～２０の整数であり、ｎは１～３０の整数である。 The secondary thiol compound or the tertiary thiol compound is not particularly limited, but is represented by the following general formula (1) from the viewpoint of curability at the time of forming the optical wavelength conversion layer and improvement of heat resistance and moisture heat resistance of the quantum dots. Compounds are preferred.

In the formula, R ¹ is an alkyl group having 1 to 10 carbon atoms which may be substituted, R ² is an alkylene group having 1 to 10 carbon atoms which may be substituted, and R ³ is a carbon atom. It is an n-valent aliphatic group having 1 to 15 carbon atoms which may contain atoms other than the above, m is an integer of 1 to 20, and n is an integer of 1 to 30.

The alkyl group of R ¹ may be linear or branched. Examples of the alkyl group of R ¹ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, and a neopentyl group. tert-Pentyl group, isopentyl group, 2-methylbutyl group, 1-ethylpropyl group, hexyl group, isohexyl group, 4-methylpentyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3 , 3-dimethylbutyl group, 2,2-dimethylbutyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethylbutyl group, 2,3-dimethylbutyl group, 1-ethylbutyl Examples thereof include a group, a 2-ethylbutyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.

The alkylene group of ^R2 may be either linear or branched. Examples of the alkylene group of R ² include a methylene group, an ethylene group, a trimethylene group, a propylene group, an isopropylene group and the like.

When the alkyl group of R ¹ or the alkylene group of R ² is substituted, the substituent includes a halogen atom, a hydroxyl group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, a carboxyl group, a phenyl group and the like. The groups to be selected are listed. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

One methylene group in the alkyl group of R ¹ or the alkylene group of R ² or two or more non-adjacent methylene groups are -O-, -S-, -SO _2- , -CO-, -COO-,-. It may be substituted with at least one group selected from the group consisting of OCO-, -NR ^4- , -CONR ^4- , -NR ⁴ CO-, -N = CH- and -CH = CH- (formula). Among them, ^R4 independently represents hydrogen or an alkyl group having 1 to 5 carbon atoms.)

Examples of the atom other than the carbon atom which may be contained in the aliphatic group of R ³ include a nitrogen atom, an oxygen atom, a sulfur atom and the like.

Of these, an alkyl group having 1 to 5 carbon atoms may be substituted with ^R1 from the viewpoint of curability during formation of light wavelength conversion particles and improvement of heat resistance and moist heat resistance of quantum dots. R ² is an alkylene group having 1 to 5 carbon atoms which may be substituted, R ³ is an aliphatic group having 1 to 10 carbon atoms, m is 1 to 10, and n is 1 to 15. A secondary thiol compound is preferable. One methylene group in the alkylene group of R ² or two or more non-adjacent methylene groups may be substituted with the same group as described above.

Specific examples of the secondary thiol compound include 1,4-bis (3-mercaptobutylyloxy) butane and 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2. , 4, 6 (1H, 3H, 5H) -trion, pentaerythritol tetrakis (3-mercaptobutyrate), trimethylolpropane tris (3-mercaptobutyrate), trimethylolethane ethanetris (3-mercaptobutyrate), etc. Can be mentioned. Specific examples of the tertiary thiol compound include tert-butyl mercaptan and the like.

式中、ｑは０または１の整数であり、Ｒ^５～Ｒ^７は、それぞれ独立して、水素、水酸基、置換されていてもよい炭素原子数１～３０の直鎖または分岐のアルキル基、置換されていてもよい炭素数１～３０の直鎖または分岐のアルコキシ基、置換されていてもよい炭素数１～３０の直鎖または分岐のアルケニル基、置換されていてもよい炭素数１～３０の直鎖または分岐のアルキニル基、置換されていてもよい炭素数３～６のシクロアルキル基、置換されていてもよいフェニル基、置換されていてもよいビフェニル基、置換されていてもよいナフチル基、置換されていてもよいフェノキシ基、または置換されていてもよい複素環基、または水酸基を表す。 (Phosphorus compound)
The phosphorus-based compound is a compound containing phosphorus. The phosphorus-based compound is not particularly limited, and examples thereof include a phosphonic acid-based compound, a phosphinic acid-based compound, a phosphine oxide-based compound, a phosphonic acid-based compound, a subphosphinic acid-based compound, and a phosphinic acid-based compound. Among these, the compound represented by the following general formula (2) is preferable from the viewpoint of curability at the time of forming the light wavelength conversion particles and improvement of heat resistance and moisture heat resistance of the quantum dots.

In the formula, q is an integer of 0 or ¹ , and R5 to ^R7 are independently hydrogen, hydroxyl group, or a linear or branched alkyl group having 1 to 30 carbon atoms which may be substituted. A linear or branched alkoxy group having 1 to 30 carbon atoms which may be substituted, a linear or branched alkenyl group having 1 to 30 carbon atoms which may be substituted, and an alkenyl group having 1 to 30 carbon atoms which may be substituted. 30 linear or branched alkynyl groups, optionally substituted cycloalkyl groups having 3 to 6 carbon atoms, optionally substituted phenyl groups, optionally substituted biphenyl groups, optionally substituted Represents a naphthyl group, an optionally substituted phenoxy group, or an optionally substituted heterocyclic group, or a hydroxyl group.

When any of R ⁵ to R ⁷ has a substituent, the substituent includes a halogen atom (F, Cl, Br), an alkyl group having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. , An alkenyl group having 1 to 6 carbon atoms, an alkynyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a (meth) acryloyl group, a (meth) acryloyloxy group, an amino group, a hydroxyl group, a carboxyl group, Examples thereof include an alkylamino group having 1 to 6 carbon atoms, a nitro group, a phenyl group, a biphenyl group, a naphthyl group, a phenoxy group, a heterocyclic group and the like.

Examples of the heterocyclic group include pyridyl group, pyrimidinyl group, pyridadyl group, pyrazole group, frill group, thienyl group, oxazolyl group, isoxazolyl group, oxadiazolyl group, thiazolyl group, isothiazolyl group, imidazolyl group, triazolyl group, pyrrole group and pyrazolyl group. , Or a tetrazolyl group.

Specific examples of the phosphorus compound include tris (2-ethylhexyl) phosphite, trilaurylphosphite, tris (tridecyl) phosphite, bis (decyl) pentaerythritol diphosphite, and bis (tridecyl) pentaerythritol diphosphite. , Triphenylphosphite, Trisnonylphenylphosphite, Butylacid phosphate, Oleyl acid phosphate, Tetracosyl acid phosphate, 2-Hydroxyethyl methacrylate acid phosphate, Dibutyl phosphate, dimethylvinyl phosphate, Di-2-ethylhexylhydrozen phosphate , Georail Hydrozenphosphite and the like.

(Nitrogen compound)
The nitrogen-based compound is a compound containing nitrogen. The nitrogen-based compound is not particularly limited, but an amine compound is preferable from the viewpoint of curability at the time of forming light wavelength conversion particles and improvement of heat resistance and moisture heat resistance of quantum dots. The amine compound may be any of a primary amine compound, a secondary amine compound, a tertiary amine compound, and a diamine compound.

Specific examples of the amine compound include laurylamine, myristylamine, cetylamine, stearylamine, oleylamine, behenylamine, distearylamine, dimethyllaurylamine, dimethylmyristylamine, dimethylstearylamine, dilaurylmonomethylamine, and trioctylamine. , Oleyl propylene diamine and the like.

(carboxylic acid)
Carboxylic acid is a compound containing at least one carboxyl group. The carboxylic acid may contain two or more carboxyl groups, or may contain a polymerizable functional group.

The weight average molecular weight of the carboxylic acid is preferably 150 or more and 50,000 or less from the viewpoint of being difficult to volatility, having excellent dispersibility, and being easy to work with. In the present specification, the "weight average molecular weight" is a value obtained by dissolving in a solvent such as tetrahydrofuran (THF) and converting into polystyrene by a conventionally known gel permeation chromatography (GPC) method. The lower limit of the weight average molecular weight of the carboxylic acid is more preferably 300 or more, and the upper limit is more preferably 10,000 or less.

The carboxyl group equivalent (weight average molecular weight / number of carboxyl groups) of the carboxylic acid is preferably 150 or more and 50,000 or less from the viewpoint of facilitating the presence of the carboxylic acid around the quantum dots. The lower limit of the carboxyl group equivalent of the carboxylic acid is more preferably 300 or more, and the upper limit is more preferably 10,000 or less.

Specific examples of the above carboxylic acid include ω-carboxy-polycaprolactone mono (meth) acrylate, monohydroxyethyl phthalate (meth) acrylate, 2-acryloyloxyethyl succinic acid, a reaction product of pentaerythritol and acrylic acid, and anhydrous succinic acid. Acid reactants include 3-buteneic acid, 10-undecenoic acid, n-octanoic acid, stearic acid, adipic acid, dodecanoic acid, 47'-dicarboxydiphenyl ether, octadecanoic acid and the like. Among these, ω-carboxy-polycaprolactone mono (meth) acrylate and 2-from the viewpoint of fixing the carboxylic acid in the resin constituting the resin particles 41B and 46B and facilitating the presence of the carboxylic acid around the quantum dots. Acryloyloxyethyl succinic acid is preferred.

(Polymerizable compound)
The polymerizable compound (curable compound) is a polymerizable compound, and examples thereof include an ionizing radiation polymerizable compound (ionizing radiation curable compound) and a thermopolymerizable compound (thermocurable compound). Examples of ionizing radiation in the present specification include visible light and ultraviolet rays, X-rays, electron beams, α rays, β rays, and γ rays.

The ionizing radiation polymerizable compound has at least one ionizing radiation polymerizable functional group in the molecule. Examples of the ionizing radiation polymerizable functional group include ethylenically unsaturated groups such as (meth) acryloyl group, vinyl group and allylic group. The "(meth) acryloyl group" means to include both "acryloyl group" and "methacryloyl group".

Examples of the ionizing radiation polymerizable compound include an ionizing radiation polymerizable monomer, an ionizing radiation polymerizable oligomer, and an ionizing radiation polymerizable prepolymer, which can be appropriately adjusted and used. As the ionizing radiation polymerizable compound, a combination of an ionizing radiation polymerizable monomer and an ionizing radiation polymerizable oligomer or an ionizing radiation polymerizable prepolymer is preferable.

Examples of the ionizing radiation polymerizable monomer include a monomer containing a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate, and ethylene glycol di (meth) acrylate. , Diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, trimethyl propantri (meth) acrylate, trimethyl ethanetri (meth). ) Acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerol (meth) acrylate (Meta) acrylic acid esters such as, etc. may be mentioned.

As the ionizing radiation polymerizable oligomer, a polyfunctional oligomer having two or more functionalities is preferable, and a polyfunctional oligomer having three or more (trifunctional) ionizing radiation polymerizable functional groups is more preferable. Examples of the polyfunctional oligomer include polyester (meth) acrylate, urethane (meth) acrylate, polyester-urethane (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, melamine (meth) acrylate, and isocyanurate. Examples thereof include (meth) acrylate and epoxy (meth) acrylate.

The ionizing radiation polymerizable prepolymer has a weight average molecular weight of more than 10,000, and the weight average molecular weight is preferably 10,000 or more and 80,000 or less, and more preferably 10,000 or more and 40,000 or less. When the weight average molecular weight exceeds 80,000, the viscosity is high, so that the coating suitability is lowered, and the appearance of the obtained light wavelength conversion member may be deteriorated. Therefore, when an ionizing radiation-polymerizable prepolymer having a weight average molecular weight of more than 80,000 is used, it is preferable to mix and use the above-mentioned polymerizable monomer and the above-mentioned polymerizable oligomer. Examples of the polyfunctional polymerizable prepolymer include urethane (meth) acrylate, isocyanurate (meth) acrylate, polyester-urethane (meth) acrylate, and epoxy (meth) acrylate.

The thermopolymerizable compound has at least one thermopolymerizable functional group in the molecule. Examples of the thermopolymerizable functional group include a cyclic ether group such as an epoxy group and an oxetanyl group, a vinyl ether group and the like.

An epoxy compound is a compound having one or more epoxy groups in the molecule. The epoxy compound is not particularly limited, but for example, bisphenol A type epoxy compound, bisphenol F type epoxy compound, bisphenol S type epoxy compound, biphenyl type epoxy compound, fluorene type epoxy compound, novolak phenol type epoxy compound, cresol novolak type epoxy. Aromatic compounds such as compounds and modified products thereof, or alkylene glycol diglycidyl ethers such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether or 1,6-hexanediol diglycidyl ether, glycerin or an alkylene oxide adduct thereof. Diglycidyl ether of polyhydric alcohol such as di or triglycidyl ether, diglycidyl ether of polyethylene glycol or its alkylene oxide adduct, polyalkylene glycol diglycidyl ether such as diglycidyl ether of polypropylene glycol or its alkylene oxide adduct, And aliphatic systems such as alkylene oxide. Here, examples of the alkylene oxide include aliphatic epoxy compounds such as ethylene oxide and propylene oxide, 3', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylmethylmethacrylate and the like. Examples thereof include an alicyclic epoxy compound containing one or more epoxy groups and one or more ester groups in the molecule.

<Coating layer>
The coating layers 41C and 46C coat the surfaces of the resin particles 41B and 46B. The coating layers 41C and 46C are preferably coat layers because they can easily cover the entire surface of the resin particles 41B and 46B. The function of the coating layer 41 is not particularly limited, but for example, the coating layers 41C and 46C have a function of maintaining the shape of the resin particles, a function of preventing the components in the resin particles from being eluted to the outside of the particles, and a dispersion liquid in the resin particles. At least one of the function of preventing permeation of components in the composition, the function of imparting barrier property to oxygen and water vapor, the function of preventing reflection of excitation light incident on resin particles, and the function of imparting resin particle dispersibility in a dispersion liquid or composition. It has the function.

The film thickness of the coating layers 41C and 46C depends on the functions exhibited by the coating layers 41C and 46C, but is 10 nm or more and 5000 nm or less from the viewpoint of ease of production and an appropriate size of the resin particles. Is preferable, and 20 nm or more and 1000 nm or less is more preferable. In particular, when the coating layers 41C and 46C exert a barrier property-imparting function, the film thickness of the coating layers 41C and 46C is 50 nm or more and 1000 nm or less from the viewpoint of preventing cracks in the coating layer while maintaining the barrier property. It is more preferable to be there. Further, when the coating layers 41C and 46C exert an antireflection function and the refractive index satisfies the relationship of binder resin <coating layer <relationship of resin particles or binder resin> coating layer> resin particles, which will be described later, the light wavelength. From the viewpoint of suppressing reflection on the surfaces of the converted particles 41 and 46 and efficiently incorporating the excitation light into the resin particles 41B and 46B, the film thickness of the coating layers 41C and 46C is more preferably 50 nm or more and 300 nm or less. For the film thickness of the coating layers 41C and 46C, a cross section of the light wavelength conversion particles 41 and 46 is photographed using a scanning electron microscope (SEM), and the film thickness of the light wavelength conversion particles 41 and 46 is measured in the image of the cross section. Measure at 20 points and use the average value of the film thickness at those 20 points.

Although it depends on the functions of the coating layers 41C and 46C, when the coating layers 41C and 46C have the function of retaining the shape of the resin particles, the coating layers 41C and 46C may be, for example, a composition for a coating layer containing a polymerizable compound. It can be formed using. Since the polymerizable compound is the same as the polymerizable compound used for forming the resin particles 41B and 46B, the description thereof will be omitted here. Among these, from the viewpoint of improving the adhesion between the resin particles and the coating layer, for example, when the resin particles are formed from an ionized radiation polymerizable compound, they are formed by using a coating layer composition containing an ionized radiation polymerizable compound. It is preferable, and when the resin particles are formed of a thermopolymerizable compound, it is preferably formed by using a composition for a coating layer containing the thermopolymerizable compound.

When the coating layers 41C and 46C form a barrier layer that suppresses the permeation of water and oxygen, examples of the constituent material of the barrier layer include inorganic oxides. Specifically, examples of the inorganic oxide include silicon oxide (SiO _x ) such as silica, aluminum oxide (Al _{n Om} ) such as alumina, titanium oxide (TIO ₂ ), yttrium oxide, and boron oxide (B). ₂ O ₃ ), calcium oxide ( _CaO ), silicon oxide nitride (SiO _x N _yCz ), etc. Among these, silica or alumina such as glass is selected from the viewpoint of low permeability of oxygen and water vapor. preferable. These materials may be used alone or in combination of two or more. It is also possible to use an inorganic oxide other than an oxide semiconductor.

The barrier layer is preferably surface-modified with a silane coupling agent from the viewpoint of improving the adhesion to the binder resins 42 and 47. The silane coupling agent may be a vinyl group, an epoxy group, a styryl group, a methacrylic group, an acrylic group, an amino group, a ureido group, a mercapto group or a sulfide group, although it depends on the type of the polymerizable compound that becomes the binder resin 16 after curing. And one having one or more reactive functional groups selected from the group consisting of isocyanate groups can be used. When a compound having a (meth) acryloyl group is used as the polymerizable compound, the coupling agent is at least one reactive substance selected from the group consisting of a mercapto group, a (meth) acryloyl group, a vinyl group and a styryl group. It is preferable to have a functional group. When a compound having at least one group selected from the group consisting of an epoxy group, an isocyanate group and a hydroxyl group is used as the polymerizable compound, the silane coupling agent is an epoxy group, an isocyanate group, a mercapto group and an amino. It is preferable to have at least one reactive functional group selected from the group consisting of groups.

When the surface of the light wavelength conversion particles is the surface of the resin particles, the light wavelength conversion particles tend to aggregate in the composition for the light wavelength conversion layer, so that the dispersibility may be poor, but the surface of the light wavelength conversion particles is a barrier. In the case of the surface of the layer, the light wavelength conversion particles are less likely to aggregate in the composition for the light wavelength conversion layer, so that the dispersibility can be improved.

The light wavelength conversion particles 41 and 46 can be produced, for example, by the following method. First, a composition for light wavelength conversion particles containing quantum dots, at least one of the above-mentioned specific compound and a carboxylic acid, and the above-mentioned polymerizable compound is cured to obtain a cured product of the composition for light wavelength conversion particles. Then, this cured product is pulverized by, for example, a bead mill. This makes it possible to obtain light wavelength conversion particles whose surface is the surface of the resin particles. The composition for light wavelength conversion particles preferably contains a polymerization initiator. The light wavelength conversion particles provided with the coating layer can be obtained by forming the coating layer on the surface of the resin particles.

The light wavelength conversion particles 41 and 46 can also be produced by the following methods. First, a composition for light wavelength conversion particles containing quantum dots, at least one of the above-mentioned specific compound and carboxylic acid, and the above-mentioned polymerizable compound is granularly dispersed in a poor solvent such as water. Then, in a state where the composition for light wavelength conversion particles is dispersed in a granular state, the polymerizable compound in the composition for light wavelength conversion particles is polymerized by, for example, suspension polymerization or emulsion polymerization, and the surface thereof is made of resin particles. It is possible to obtain light wavelength conversion particles on the surface. The "poor solvent" means a solvent in which the composition for light wavelength conversion particles is hardly dissolved, and examples thereof include polar solvents such as water. The composition for light wavelength conversion particles preferably contains a polymerization initiator. Also in this case, the light wavelength conversion particles provided with the coating layer can be obtained by forming the coating layer on the surface of the resin particles in the same manner as described above.

When the barrier layer is formed as the coating layers 41C and 46C on the surfaces of the resin particles 41B and 46B, the barrier layer can be produced by using the sol-gel method. Specifically, first, an appropriate amount of a metal alkoxide (1) such as tetraethoxysilane is added to the resin particles and hydrolyzed appropriately to hydrolyze the surface of the resin particles with the metal alkoxide (1). Replace with an object. Such a liquid is referred to as an organic solvent A. On the other hand, an aqueous solution B is obtained by dispersing a metal alkoxide (2) such as 3-mercaptopropyltrimethoxysilane in the aqueous solution and partially hydrolyzing the metal alkoxide (2). Here, as the metal alkoxide (2), one having a slower hydrolysis rate than the metal alkoxide (1) is selected. Then, by mixing the organic solution A and the aqueous solution B, a layer of the metal alkoxide (2) is further formed on the surface of the resin particles covered with the metal alkoxide (1). The resin particles settle in the aqueous phase. Since the metal alkoxide (2) near the surface is hydrolyzed at a slower rate than the metal alkoxide (1), the alkoxide on the surface of the resin particles is dehydrated and condensed at once when it precipitates in the aqueous phase, forming a large lump. prevent. An inorganic oxide layer such as a silica glass layer is further deposited on the resin particles in the aqueous phase. This can be done by hydrolyzing a small amount of metal alkoxide (3) in the alkaline region with a large amount of water and alcohol and depositing it on the core resin particles by the usual Stöber process. This makes it possible to form a barrier layer.

<< Binder resin >>
The binder resins 42 and 47 are not particularly limited, but are the same as the binder resin of the light-shielding layer 30, so the description thereof will be omitted here.

<< Light-scattering particles >>
The light scattering particles are particles having an action of changing the traveling direction of light by scattering the light that has entered the light wavelength conversion layer.

The average particle size of the light-scattering particles is preferably 20 times or more and 2000 times or less, and more preferably 50 times or more and 1000 times or less the average particle size of the quantum dots. If the average particle size of the light-scattering particles is 20 times or more the average particle size of the quantum dots, sufficient light-scattering performance can be obtained in the light wavelength conversion layer, and the average particle size of the light-scattering particles is the quantum dots. If the average particle size is 2000 times or less, the number of light-scattering particles is larger when the addition amount is the same than when the addition amount is more than 2000 times, so that the number of scattering points is large and a sufficient light scattering effect is obtained. Can be obtained. The average particle size of the light-scattering particles can be measured by the same method as the above-mentioned average particle size of the quantum dots.

The average particle size of the light-scattering particles is preferably 1/300 or more and 1/20 or less, and more preferably 1/200 or more and 1/30 or less of the average film thickness of the light wavelength conversion layer. When the average particle size of the light scattering particles is 1/300 or more of the average film thickness of the light wavelength conversion layer, sufficient light scattering performance can be obtained in the light wavelength conversion layer, and the average particle size of the light scattering particles can be obtained. If is 1/20 or less of the average film thickness of the light wavelength conversion layer, the ratio of light scattering particles to the light wavelength conversion layer is larger when the addition amount is the same than when it exceeds 1/20. The number of scattering points is large, and a sufficient light scattering effect can be obtained.

Specifically, the average particle size of the light-scattering particles is, for example, preferably 0.1 μm or more and 10 μm or less, and more preferably 0.3 μm or more and 5 μm or less. When the average particle diameter of the light-scattering particles is 0.1 μm or more, the light wavelength conversion efficiency of the light wavelength conversion member is sufficient. On the other hand, when the average particle size of the light-scattering particles is 10 μm or less, the number of light-scattering particles is larger when the addition amount (mass%) is the same than when the average particle size of the light-scattering particles exceeds 10 μm. Therefore, the number of scattering points increases, and a sufficient light scattering effect can be obtained.

The shape of the light-scattering particles is not particularly limited, and for example, spherical (true spherical, substantially true spherical, elliptical spherical, etc.), polyhedral, rod-shaped (cylindrical, prismatic, etc.), flat plate, flaky, and indefinite shape. And so on. When the shape of the light-scattering particles is not spherical, the particle diameter of the light-scattering particles can be a true spherical value having the same volume.

The light-scattering particles are preferably surface-treated with a silane coupling agent from the viewpoint of firmly fixing the light-scattering particles in the binder resin. By surface-treating with a silane coupling agent, it can be chemically bonded to a binder resin described later.

The silane coupling agent is a group consisting of a vinyl group, an epoxy group, a styryl group, a methacrylic group, an acrylic group, an amino group, a ureido group, a thiol group, a sulfide group and an isocyanate group, although it depends on the type of the polymerizable compound used. It is possible to use one having one or more reactive functional groups selected from. When a compound having a (meth) acryloyl group is used as the polymerizable compound, the coupling agent is at least one reactive selected from the group consisting of a thiol group, a (meth) acryloyl group, a vinyl group and a styryl group. It is preferable to have a functional group. When a compound having at least one group selected from the group consisting of an epoxy group, an isocyanate group and a hydroxyl group is used as the polymerizable compound, the silane coupling agent is an epoxy group, an isocyanate group, a thiol group and an amino. It is preferable to have at least one reactive functional group selected from the group consisting of groups.

The light-scattering particles may be organic particles such as acrylic resin particles, styrene resin particles, melamine resin particles, and urethane resin particles, but the rate of change in brightness before and after the heat resistance test can be reduced, and light can be used. Inorganic particles are preferable because the incident light to the wavelength conversion layer can be suitably scattered and the light wavelength conversion efficiency with respect to the incident light can be preferably improved.

The inorganic particles include an aluminum-containing compound such as Al ₂ O ₃ , a zirconium-containing compound such as ZrO ₂ , a tin-containing compound such as antimony-doped tin oxide (ATO) and indium tin oxide (ITO), and magnesium such as MgO and MgF ₂ . At least one compound selected from the group consisting of compounds, titanium-containing compounds such as TiO ₂ and BaTiO ₃ , antimony-containing compounds such as Sb ₂ O ₅ , silicon-containing compounds such as SiO ₂ , and zinc-containing compounds such as ZnO. Particles can be mentioned. Since these inorganic particles can increase the difference in refractive index from the binder resin, they are also preferable from the viewpoint of obtaining a large Mie scattering intensity. The light scattering particles may be made of two or more kinds of materials because it is possible to more preferably improve the light wavelength conversion efficiency with respect to the incident light by the light wavelength conversion layer.

<< Light diffusion layer >>
The light diffusion layer 50 has a function of diffusing the light from the light emitting element 23. When an LED element is used as the light emitting element, the LED element has strong directivity, so a light diffusion layer 50 is arranged to diffuse the light from the LED element.

The light diffusing layer 50 contains light scattering particles and a binder resin. Since the light-scattering particles and the binder resin are the same as the light-scattering particles and the binder resins 42 and 47 described in the columns of the light wavelength conversion layers 40 and 45, the description thereof will be omitted here.

The film thickness of the light diffusion layer 50 is not particularly limited, but is preferably 0.5 μm or more and 50 μm or less. When the film thickness of the light diffusion layer 50 is 0.5 μm or more, sufficient light diffusion performance can be obtained, and when the film thickness is 50 μm or less, it is suitable for thinning the image display device. The lower limit of the film thickness of the light diffusion layer 50 is more preferably 2 μm, and the upper limit is more preferably 20 μm or less. The film thickness of the light diffusion layer 50 can be measured by the same method as the film thickness of the light shielding layer 30.

<< Colored layer >>
The colored layers 60 and 65 have a function of transmitting light wavelength-converted by the quantum dots 41A and 46A and absorbing light from the light emitting element 23. In the present embodiment, since the quantum dot 41A converts blue light into green light, the colored layer 60 transmits the green light wavelength-converted by the quantum dot 41A and is blue from the light emitting element 23. It is a green colored layer that absorbs light. Further, since the quantum dot 46A converts blue light into red light, the colored layer 65 transmits the red light wavelength-converted by the quantum dot 46A and absorbs the blue light from the light emitting element 23. It is a red colored layer.

The colored layer 70 has a function of transmitting light in a predetermined wavelength range including light diffused by the light diffusing layer 50 and absorbing light in other wavelength ranges. In the present embodiment, since the light diffused by the light diffusing layer 50 is blue light, the colored layer 70 is a blue colored layer that transmits blue light and absorbs light other than blue light.

The colored layers 60, 65, and 70 contain a coloring material and a binder resin. The film thickness of the colored layers 60, 65, and 70 can be the same as the film thickness of a general colored layer in a color filter, and may be, for example, 1 μm or more and 5 μm or less.

<Color material>
The coloring material is not particularly limited, and examples thereof include pigments and dyes of each color. Examples of the green color material used for the green coloring layer include phthalocyanine pigments such as halogen polysubstituted phthalocyanine pigments or halogen polysubstituted copper phthalocyanine pigments, triphenylmethane basic dyes, isoindolin pigments, and isoindolinones. Examples include system pigments. Examples of the red coloring material used for the red coloring layer include perylene-based pigments, lake pigments, azo-based pigments, quinacridone-based pigments, anthraquinone-based pigments, anthracene-based pigments, and isoindoline-based pigments. Examples of the blue coloring material used for the blue coloring layer include copper phthalocyanine pigments, anthraquinone pigments, indanthrone pigments, indanthrone pigments, cyanine pigments, dioxazine pigments and the like. These pigments and dyes may be used alone or in combination of two or more.

<Binder resin>
As the binder resin, the same binder resin as that described in the column of the light-shielding layer 30 can be used, so the description thereof will be omitted here.

<< Barrier member >>
The barrier member 80 is a member for suppressing the permeation of water and oxygen to protect the quantum dots 41A and 46A from water and oxygen. Here, the "barrier member" in the present specification means that the member alone has a water vapor transmittance of less than 0.1 g / ( ^m 2.24 h) at 40 ° C. and a relative humidity of 90%, and has a relative humidity of 23 ° C. It shall mean a member having an oxygen permeability of less than 0.1 cm ³ / ( ^m 2.24 h · atm) at 90%. The barrier member includes not only a single-layer structure member but also a multi-layer structure member. By installing the barrier member while sandwiching the optical wavelength conversion layer, deterioration of the quantum dots can be suppressed.

The water vapor transmission rate (WVTR) of the barrier member 80 is 1.0 × 10 ⁻² g / ( ^m 2.24 h) or less under the conditions of 40 ° C. and 90% relative humidity. preferable. The water vapor permeability can be measured using a water vapor permeability measuring device (product name "PERMATRAN-W3 / 31", manufactured by MOCON). The water vapor transmittance shall be the arithmetic mean value of the values obtained by measuring three times.

The oxygen transmission rate (OTR) of the barrier member 80 shall be 1.0 × 10 ⁻² cm ³ / ( ^m 2.24 h · atm) or less under the conditions of 23 ° C. and 90% relative humidity. Is more preferable. The oxygen permeability can be measured using an oxygen gas permeability measuring device (product name "OX-TRAN 2/21", manufactured by MOCON). The oxygen permeability shall be the arithmetic mean value of the values obtained by measuring three times.

The barrier member 80 shown in FIG. 1 is made of glass. The barrier member 80 is composed of a light-transmitting base material having no barrier property and a barrier layer provided on the light wavelength conversion unit layer side of the light-transmitting base material and having a function of suppressing the transmission of water and oxygen. It may have been done.

The barrier layer is composed of a thin-film deposition layer having a function of suppressing the permeation of water and oxygen. The thin-film deposition layer is a layer formed by a vapor deposition method such as a physical vapor deposition (PVD) method such as a sputtering method or an ion plating method or a chemical vapor deposition (CVD) method. The thin-film deposition layer has the advantage that the barrier property can be enhanced.

The material for forming the thin-film vapor deposition layer is not particularly limited as long as it can be vapor-deposited by a thin-film deposition method and can obtain a barrier property, and examples thereof include inorganic oxides such as silicon oxide and aluminum oxide, and metals.

The film thickness of the thin-film deposition layer is not particularly limited, but is preferably 0.01 μm or more and 1 μm or less. When the film thickness of the thin-film vapor deposition layer is 0.01 μm or more, the barrier performance of the thin-film deposition layer is sufficient, and when the film thickness is 1 μm or less, cracks or the like of the thin-film deposition layer are unlikely to occur. The lower limit of the film thickness of the vapor-filmed layer is more preferably 0.03 μm or more, and the upper limit is more preferably 0.5 μm or less. The film thickness of the thin-film deposition layer can be measured by the same method as the film thickness of the light-shielding layer.

<< Circularly polarizing plate >>
The circular polarizing plate 90 has a function of suppressing external light reflection. Specifically, when the external light is incident on the image display device 10, the green light contained in the external light is transmitted through the colored layer 60, and the red light contained in the external light is transmitted through the colored layer 65 and is included in the external light. Since the blue light is transmitted through the colored layer 70, it may be reflected by the package 24 and emitted to the outside of the image display device 10. However, the circularly polarizing plate 90 is closer to the observer than the colored layers 60, 65, 70. By providing the above, the external light reflected by the package 24 is absorbed by the circularly polarizing plate 90.

<<<< Other image display device >>>>>
In the image display device 10 shown in FIG. 1, the light wavelength conversion particles 41 and 46 are used, but instead of the light wavelength conversion particles 41 and 46 or together with the light wavelength conversion particles 41 and 46, water and oxygen are used. Light wavelength conversion particles containing light-transmitting barrier particles that suppress transmission and quantum dots contained in the barrier particles may be used.

In the image display device 100 shown in FIG. 3, the optical wavelength conversion layers 110 and 115 are used instead of the optical wavelength conversion layers 40 and 45. Of the members shown in FIGS. 3 and subsequent drawings, those having the same reference numerals as the members shown in FIG. 1 are the same as the members shown in FIG. 1, so the description thereof is omitted. It shall be.

<<< Optical wavelength conversion layer >>>
The optical wavelength conversion layers 110 and 115 have a function of converting the wavelength of incident light into another wavelength. In the present embodiment, the light wavelength conversion layer 110 has a function of converting blue light into green light, and the light wavelength conversion layer 115 has a function of converting blue light into red light. The optical wavelength conversion layer 110 includes the optical wavelength conversion particles 111 and the binder resin 42, and the optical wavelength conversion layer 115 includes the optical wavelength conversion particles 112 and the binder resin 47. The light wavelength conversion layer 111115 may include light wavelength conversion particles 111, 116, binder resins 42, 47, and light scattering particles.

<< Light wavelength conversion particles >>
The light wavelength conversion particles 111 and 116 are also particles that convert the wavelength of incident light into another wavelength. As shown in FIGS. 4A and 4B, the light wavelength conversion particles 111 and 116 are light-transmitting barrier particles 111A and 116A that suppress the transmission of water and oxygen, and barrier particles 111A and 116A. Includes quantum dots 41A and 46A contained in. There is no air layer between the quantum dots 41A and 46A and the barrier particles 111A and 116A, and the surface of the quantum dots 41A and 46A is in close contact with the barrier particles 111A and 116A.

The optical wavelength conversion particles 111 and 116 preferably contain 1 or more and 50 or less quantum dots 41A and 46A per particle, and preferably 1 or more and 40 or less or 1 or more and 35 or less quantum dots per particle. It is more preferable to include dots 41A and 46A. If the number of quantum dots contained in one light wavelength conversion particle is less than one, the brightness may be lowered, and if the number of quantum dots contained in one light wavelength conversion particle exceeds 50, the quantum is quantum. Luminous efficiency may decrease due to concentration dimming that causes quenching due to energy transfer between dots. The number of quantum dots contained in one light wavelength conversion particle is 100,000 times the cross section of 20 light wavelength conversion particles at random using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). It is obtained by taking a picture at a magnification of ~ 500,000 times, calculating the number of quantum dots contained in one optical wavelength conversion particle from the obtained image of the cross section, and calculating the average value of the calculated number of quantum dots. be able to.

The average particle diameter of the optical wavelength conversion particles 111 and 116 is preferably 10 nm or more and 500 nm or less. If the average particle size of the optical wavelength conversion particles is 10 nm or more, sufficient barrier properties can be imparted to the quantum dots, and if it is 500 nm or less, the barrier properties of the barrier particles are not clear, although the reason is not clear. There is no risk of instability. The average particle size of the light wavelength conversion particles is obtained by measuring the particle size of 20 light wavelength conversion particles in the cross-sectional observation of the light wavelength conversion sheet with a transmission electron microscope or a scanning transmission electron microscope, and calculating the average value. You can ask. The lower limit of the average particle size of the light wavelength conversion particles 111 and 116 is preferably 20 nm or more, and the upper limit of the average particle size of the light wavelength conversion particles 111 and 116 is preferably 200 nm or less, preferably 100 nm or less. Is more preferable.

<Barrier particles>
The barrier particles 111A and 116A contain quantum dots 41A and 46A, have a light transmissive property, and have a barrier property of suppressing the permeation of water and oxygen. By wrapping the quantum dots 41A and 46A with the barrier particles 111A and 116A, it is possible to prevent the quantum dots 41A and 46A from coming into contact with water and oxygen, so that the quantum dots 41A and 46A can be prevented from being deteriorated by water and oxygen. .. As a result, it is possible to suppress a decrease in the luminous efficiency of the quantum dots 41A and 46A without providing a barrier layer. In the present specification, "light transmission" means having a property of transmitting light, and "light transmission" also includes transparency. In the present invention, since the quantum dots are included in the barrier particles, it can be said that the barrier particles have light transmittance if the light emission from the quantum dots emitted from the light wavelength conversion sheet can be confirmed. The emission of quantum dots can be confirmed using a fluorometer.

The material for forming the barrier particles 111A and 116A is not particularly limited as long as it has light transmittance and barrier properties, and examples thereof include inorganic oxides. Specifically, examples of the inorganic oxide include silicon oxide (SiO _x ) such as silica, aluminum oxide (Al _{n Om} ) such as alumina, titanium oxide (TIO ₂ ), yttrium oxide, and boron oxide (B). ₂ O ₃ ), calcium oxide ( _CaO ), silicon oxide nitride (SiO _x N _yCz ), etc. Among these, silica or alumina such as glass is selected from the viewpoint of low permeability of oxygen and water vapor. preferable. These materials may be used alone or in combination of two or more. It is also possible to use an inorganic oxide other than an oxide semiconductor.

When the quantum dots 41A and 46A contain Cd, the thickness of the barrier particles 111A and 116A (distance from the surface of the quantum dots to the outer surface of the barrier particles) in order to prevent the elution of Cd contained in the quantum dots 41A and 46A. Is preferably 2 nm or more, and more preferably 4 nm or more. When the average particle diameter of the light wavelength conversion particles 41 and 46 is about 50 nm, the thickness of the barrier particles 111A and 116A can be 10 nm or more. Further, when the average particle diameter of the light wavelength conversion particles 41 and 46 is about 100 nm, the thickness of the barrier particles 111A and 116A can be 20 nm or more. The thickness of the barrier particles can be easily measured as an outer portion that does not contain quantum dots in transmission electron microscope observation. When the thickness differs depending on the position of the peripheral edge of the barrier particle, the thickness of the barrier particle is taken by averaging the entire peripheral edge of the barrier particle.

The barrier particles 111A and 116A are preferably chemically bonded to the binder resins 42 and 47 from the viewpoint of improving the adhesion to the binder resins 42 and 47. This chemical bond can be carried out by the barrier particles 111A and 116A surface-modified with a silane coupling agent.

The silane coupling agent may be a vinyl group, an epoxy group, a styryl group, a methacrylic group, an acrylic group, an amino group, a ureido group, a mercapto group, a sulfide group and an isocyanate group, depending on the type of curable binder resin precursor used. It is possible to use one having one or more reactive functional groups selected from the group consisting of. When a compound having a (meth) acryloyl group is used as the curable binder resin precursor, the coupling agent is at least one selected from the group consisting of a mercapto group, a (meth) acryloyl group, a vinyl group and a styryl group. It is preferable to have a reactive functional group of. When a compound having at least one group selected from the group consisting of an epoxy group, an isocyanate group, and a hydroxyl group is used as the curable binder resin precursor, the silane coupling agent is an epoxy group, an isocyanate group, or a mercapto. It is preferred to have at least one reactive functional group selected from the group consisting of groups and amino groups.

As a method of surface-treating the barrier particles 111A and 116A with a silane coupling agent, a dry method of spraying the silane coupling agent on the barrier particles 111A and 116A or a method of dispersing the barrier particles 111A and 116A in a solvent and then silane coupling is performed. Examples thereof include a wet method in which an agent is added and reacted.

The optical wavelength conversion particles 111 and 116 can be produced, for example, by using the sol-gel method (see Patent No. 5682069). Specifically, first, quantum dots are prepared, and an appropriate amount of a metal alkoxide (1) such as tetraethoxysilane is added to the quantum dots and hydrolyzed appropriately to surface the surface of the quantum dots. Substitute with the hydrolyzate of (1). Such a liquid is referred to as an organic solvent A. On the other hand, an aqueous solution B is obtained by dispersing a metal alkoxide (2) such as 3-mercaptopropyltrimethoxysilane in the aqueous solution and partially hydrolyzing the metal alkoxide (2). Here, as the metal alkoxide (2), one having a slower hydrolysis rate than the metal alkoxide (1) is selected. Then, by mixing the organic solution A and the aqueous solution B, a layer of the metal alkoxide (2) is further formed on the surface of the quantum dots covered with the metal alkoxide (1). Quantum dots that come into contact with water become hydrophilic and move to the aqueous phase as the metal alkoxide on the surface is hydrolyzed. At this time, the quantum dots form an aggregate. Since the metal alkoxide (2) near the surface is hydrolyzed at a slower rate than the metal alkoxide (1), the alkoxide on the surface of the quantum dots is dehydrated and condensed at once when it moves to the aqueous phase, forming a large mass. prevent. An inorganic oxide layer such as a silica glass layer is further deposited on the aggregate in the aqueous phase. This can be done by hydrolyzing a small amount of metal alkoxide (3) in the alkaline region with a large amount of water and alcohol and depositing it on an aggregate of core quantum dots by the usual Stöber process. Thereby, the light wavelength conversion particles 111 and 116 can be obtained.

<<<< Other image display device >>>>>
In the image display devices 10 and 100, since the resin particles 41B and 46B and the barrier particles 111A and 116A that can suppress the deterioration of the quantum dots 41A and 46A contain the quantum dots 41A and 46A, the light emitting element 24 and the optical wavelength conversion are performed. When the barrier layer is not formed between the layers 40 and 45, but the quantum dots are not surrounded by the resin particles or the barrier particles, the barrier layer may be formed between the light emitting element and the optical wavelength conversion layer. preferable.

In the image display device 120 shown in FIG. 5, barrier layers 140 and 145 are formed between the light emitting element 23 and the light wavelength conversion layers 130 and 135.

<< Optical wavelength conversion layer >>
The optical wavelength conversion layers 130 and 135 shown in FIG. 5 include quantum dots 41A and 46A and binder resins 42 and 47, but the quantum dots 41A and 46A are not included in the resin particles or barrier particles.

<< Barrier layer >>
Since the barrier layers 140 and 145 have a function of suppressing the permeation of water and oxygen and are the same as the barrier layer described in the column of the barrier member 80, the description thereof will be omitted here.

<<< Manufacturing method of image display device >>>
The image display device 10 can be manufactured, for example, as follows. First, the light-shielding layer composition is applied to one surface side of the barrier member 80 and dried to form a coating film of the light-shielding layer composition.

After forming the coating film, it is exposed so that an opening is formed, developed, and heat-treated to form a light-shielding layer 30 having openings 30A, 30B, and 30C.

Next, using the composition for each colored layer, the colored layers 60, 65, and 70 are formed in the openings 30A, 30B, and 30C of the light-shielding layer 30 in the same manner as the light-shielding layer 30. After forming the colored layers 60, 65, and 770, the light diffusing layer 50 is formed in the opening 30C by the same method as that of the light shielding layer 30 by using the composition for the light diffusing layer.

After forming the light diffusion layer 50, the light wavelength conversion layers 40 and 45 are formed in the openings 30A and 30B in the same manner as the light shielding layer 30 by using the composition for the light wavelength conversion layer.

The viscosity of the composition for the optical wavelength conversion layer is preferably 10 mPa · s or more and 10,000 mPa · s or less. If the viscosity of the composition for the light wavelength conversion layer is less than 10 mPa · s, it may be difficult to form a sufficient film thickness, and if it exceeds 10,000 mPa · s, the composition for the light wavelength conversion layer is used. When applying, it becomes difficult to apply, and the leveling property may deteriorate. The lower limit of the viscosity of the composition for the light wavelength conversion layer is preferably 10 mPa · s or more, and the upper limit of the viscosity of the composition for the light wavelength conversion layer is preferably 10000 mPa · s or less.

The content of the quantum dots with respect to the total solid content mass of the composition for the optical wavelength conversion layer is preferably 1% by mass or more and 40% by mass or less, and more preferably 3% by mass or more and 30% by mass or less. When the content of the quantum dots is 1% by mass or more, sufficient emission intensity can be obtained, and when the content of the quantum dots is 40% by mass or less, the processing at the time of film formation becomes easy.

The content of the polymerizable compound with respect to the total solid content mass of the composition for the optical wavelength conversion layer is preferably 30% by mass or more, and preferably 50% by mass or more and 99% by mass or less. When the content of the polymerizable compound is 30% by mass or more, sufficient curability can be obtained when the composition for the optical wavelength conversion layer is cured.

After forming the optical wavelength conversion layers 40 and 45, the light emitting element package 21 having the light emitting element 23 is provided with an adhesive layer such as OCA (Optical Clear Adhesive) so that the light emitting element 23 is on the optical wavelength conversion layers 40 and 45 side. , Attached to the light shielding layer 30 and the light wavelength conversion layers 40 and 45. Finally, the circular polarizing plate 90 is attached to the other surface side of the barrier member 80. As a result, the image display device 10 shown in FIG. 1 is obtained.

According to the present embodiment, the light emitting element 23 is arranged for each subpixel, and the optical wavelength conversion layers 40 and 45 including the quantum dots 41A and 46A and the optical wavelength conversion layers 110 and 115 are provided at positions corresponding to the light emitting elements 23. By arranging the light emitting elements 23 on and off, the same function as the shutter function of the liquid crystal cell can be obtained, so that the image can be displayed without using the liquid crystal cell. As a result, since the liquid crystal cell can be omitted, the image display devices 10 and 100 using the quantum dots 41A and 46A having a simplified structure can be obtained.

According to the present embodiment, since the colored layers 60 and 65 are arranged on the observer side of the light wavelength conversion layers 40 and 45, the light wavelength-converted by the quantum dots 41A and 43A in the colored layers 60 and 65. It is possible to absorb the light emitted from the light emitting element 23 emitted from the optical wavelength conversion layers 40 and 45 without being wavelength-converted by the quantum dots 41A and 43A. As a result, light with high color purity can be emitted from the image display device 10.

When external light is incident on the light wavelength conversion layers 40 and 45, the light wavelength conversion layer may emit light due to the blue light contained in the external light, but the colored layer 60 is closer to the observer than the light wavelength conversion layers 40 and 45. , 65 are arranged, so that blue light can be absorbed by the colored layers 60 and 65. This makes it possible to suppress light emission due to external light.

It is considered that the reason why quantum dots are deteriorated by water and oxygen is as follows. First, as described above, a ligand composed of a sulfur-based compound, a phosphorus-based compound, or the like is coordinated on the surface of the quantum dot, and this ligand is easily desorbed by light or heat. When the ligand is desorbed from the quantum dots, water and oxygen are likely to adhere to the quantum dots, so that the quantum dots are oxidized and deteriorated. It is considered that this causes the quantum dots to deteriorate. On the other hand, in the present embodiment, the light wavelength conversion layers 40 and 45 contain resin particles 41B and 46B containing at least one of one or more elements selected from the group consisting of sulfur, phosphorus and nitrogen and a carboxylic acid. Since the optical wavelength conversion particles 41 and 46 containing the quantum dots 41A and 46A are used, at least one of a sulfur component, a phosphorus component, a nitrogen component and a carboxylic acid should be present in the vicinity of the quantum dots 41A and 46A. As a result, deterioration of the quantum dots 41A and 46A can be suppressed. This is such that at least one of the sulfur component, phosphorus component, nitrogen component and carboxylic acid present in the resin particles 41B, 46B assists the role of the ligand even when the ligand is desorbed from the quantum dots. It is considered that this is because it exerts a function (for example, at least one of the function of binding to a quantum dot instead of the ligand and the function of substituting the ligand and the function of capturing oxygen). Further, in the optical wavelength conversion layers 110 and 115, since the optical wavelength conversion particles 111 and 116 in which the quantum dots 41A and 46A are included in the barrier particles 111A and 116A are used, the quantum dots 41A and 116A are formed by the barrier particles 111A and 116A. The 46A can be protected from water and oxygen, and the deterioration of the quantum dots 41A and 46A can be suppressed. Therefore, in either case, deterioration of the quantum dots 41A and 46A can be suppressed without covering both sides of the optical wavelength conversion layers 40 and 45 with a barrier member.

As described above, in the present embodiment, the resin particles 41B and 46B containing the quantum dots 41A and 46A are at least one of one or more elements and carboxylic acids selected from the group consisting of sulfur, phosphorus and nitrogen. Since it contains, deterioration of the quantum dots 41A and 46A can be suppressed as compared with the resin particles containing no such element or carboxylic acid, but in the quantum dots, a part of the surface of the quantum dots is made of resin. Some are exposed on the surface of the particles. When the coating layers 41C and 46C are barrier layers that suppress the permeation of water and oxygen, even if a part of the quantum dots 41A and 46A is exposed on the surfaces of the resin particles 41B and 46B. Since the barrier layer can suppress the contact between the quantum dots 41A and 46A partially exposed from the resin particles 41B and 46B and the moisture and oxygen, the deterioration of the quantum dots 41A and 46A can be further suppressed.

[Second Embodiment]
Hereinafter, the image display device according to the second embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a schematic configuration diagram of an image display device according to the present embodiment.

<<<<< Image display device >>>>>
The image display device 150 shown in FIG. 6 has a light source 20 including one or more light emitting elements 23, and openings 30A, 30B, and 30C arranged on the observer side of the light emitting element 23 and at positions corresponding to the light emitting elements 23. The light-shielding layer 30, the light wavelength conversion layers 160 and 165 arranged in the openings 30A and 30B, the light diffusion layer 50 arranged in the openings 30C, and the light wavelength conversion layers 160 and 165 in the openings 30A and 30B. The colored layers 60 and 65 as the first colored layer arranged on the observer side, and the colored layers 70 arranged in the opening 30C and on the observer side of the light diffusion layer 50, and in the openings 30A and 30B. Further, it includes colored layers 170 and 175 as a second colored layer arranged on the light emitting element 23 side of the light wavelength conversion layers 160 and 165. The image display device 150 includes a barrier member 80 and a circularly polarizing plate 90 in this order toward the observer side of the colored layers 60 and 70. Further, the image display device 150 includes a barrier member 180 arranged so as to face the barrier member 90 on the light emitting element 23 side of the light shielding layer 30 and the coloring layer 170 and 175. The light-shielding layer 30 is in contact with the barrier member 180. The light source 20 is integrated with the barrier member 180 via a light-transmitting adhesive layer 95.

<< Optical wavelength conversion layer >>
The optical wavelength conversion layers 160 and 165 shown in FIG. 6 include quantum dots 41A and 46A and binder resins 42 and 47, but the quantum dots 41A and 46A are not included in the resin particles or barrier particles.

<< Colored layer >>
The colored layers 170 and 175 have a function of transmitting the light from the light emitting element 23 and absorbing the light wavelength-converted by the quantum dots 41A and 46A. Specifically, since the quantum dot 41A converts blue light into green light, the colored layer 170 transmits the blue light from the light emitting element 23 and the wavelength of the green light is converted by the quantum dot 41A. It is a blue colored layer that absorbs light. Further, since the quantum dot 46A converts blue light into red light, the colored layer 175 transmits the blue light from the light emitting element 23 and absorbs the red light wavelength-converted by the quantum dot 46A. It is a blue colored layer.

The colored layers 170 and 175 contain a coloring material and a binder resin. Since the coloring materials and binder resins of the coloring layers 170 and 175 are the same as those of the coloring layer 70, the description thereof will be omitted here.

<< Barrier member >>
Since the barrier member 180 is the same as the barrier member 90, the description thereof will be omitted here.

According to the present embodiment, the light emitting element 23 is arranged for each sub-pixel, and the optical wavelength conversion layers 160 and 165 including the quantum dots 41A and 46A are arranged at the positions corresponding to the light emitting element 23, and each light emitting element 23 is arranged. By turning on / off, the same function as the shutter function of the liquid crystal cell can be obtained, so that the image can be displayed without using the liquid crystal cell. As a result, since the liquid crystal cell can be omitted, the image display device 150 using the quantum dots 41A and 46A having a simplified structure can be obtained.

According to the present embodiment, since the light wavelength conversion layers 160 and 165 are sandwiched between the barrier members 80 and 180, deterioration of the quantum dots 41A and 46A due to moisture and oxygen can be suppressed by the barrier members 80 and 180.

When the external light is incident on the colored layers 60 and 65, the green light contained in the external light is transmitted through the colored layer 60, and the red light contained in the external light is transmitted through the colored layer 65, but further transmitted through the barrier member 180. When it reaches the light source 20 side, it is reflected by the package 24 and becomes stray light, which may enter other sub-pixels. According to the present embodiment, since the colored layer 170 is arranged on the light emitting element 23 side of the light wavelength conversion layer 160, the green light transmitted through the colored layer 60 can be absorbed by the colored layer 170, and the light can be absorbed. Since the colored layer 175 is arranged on the light emitting element 23 side of the wavelength conversion layer 165, the red light transmitted through the colored layer 65 can be absorbed by the colored layer 175. As a result, the generation of stray light can be suppressed.

In order to explain the present invention in detail, examples will be given below, but the present invention is not limited to these descriptions.

<Manufacturing of light wavelength conversion particles>
Light wavelength conversion particles were obtained according to the following procedure.
(Light wavelength conversion particle G1)
In a polymerization vessel equipped with a stirrer, first, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), tetraethylene glycol bis (3-mercaptopropionate). (Product name "EGMP-4", manufactured by SC Organic Chemistry) 50 parts by mass, green light emitting quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size Composition for light wavelength conversion particles consisting of 1.0 part by mass (3.3 nm) and 1 part by mass of thermal radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) A substance G1 was prepared, and a solvent prepared by dissolving 10 parts by mass of polyvinyl alcohol as a dispersant in 900 parts by mass of ion-exchanged water was added thereto. Then, the composition G1 for light wavelength conversion particles was finely dispersed as droplets in a poor solvent by stirring with a stirring device at a stirring speed of 400 rpm for 10 minutes. Subsequently, stirring by the stirrer is continued at a stirring speed of 400 rpm, the temperature of the reaction solution containing the composition G1 for light wavelength conversion particles and the poor solvent is raised to 50 ° C., and the temperature of the reaction solution is 50 ° C. Suspension polymerization is carried out in this state for 3 hours, and then the temperature of the reaction solution is raised to 80 ° C. in order to completely inactivate the thermal radical initiator, and the temperature of the reaction solution is 80 ° C. The mixture was stirred for 3 hours to obtain a particulate polymer. Then, the reaction solution containing the polymer in the polymerization vessel was cooled to room temperature while stirring with a stirrer. Then, the reaction solution was suction-filtered, the residue of the filtration was washed with ion-exchanged water, and then the solution was removed to obtain light wavelength conversion particles 1. In the light wavelength conversion particles 1, green emission quantum dots were included in the resin particles, and the average particle size of the light wavelength conversion particles 1 was 3 μm. The average particle size of the light wavelength conversion particles A1 was determined by measuring the particle size of 20 light wavelength conversion particles G1 with a transmission electron microscope and calculating the average value thereof. The average particle diameters of the following light wavelength conversion particles 2 to 12 were also determined to be the same as those of the light wavelength conversion particles 1.

(Light wavelength conversion particle R1)
In the light wavelength conversion particle B1, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) The light wavelength conversion particles R1 were obtained by the same procedure as the light wavelength conversion particles G1 except that the composition R1 for the light wavelength wavelength conversion particles containing 1.0 part by mass was used. In the light wavelength conversion particles R1, red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles R1 was 3 μm.

(Light wavelength conversion particle G2)
A silica glass layer as a barrier layer was formed on the surface of the resin particles of the light wavelength conversion particles G1 to obtain light wavelength conversion particles 2. The formation of the barrier layer was performed as follows. First, the surface of the light wavelength conversion particles 1 was covered with dodecylamine and then mixed with toluene (0.4 mL). Next, tetraethoxysilane (TEOS, 10 μL) was added to this mixture, and the mixture was stirred for 3 hours to prepare an organic mixture 1. On the other hand, 3-mercaptopropyltrimethoxysilane (MPS, 1 μL) was mixed with ethanol (25 mL) and aqueous ammonia (4 mL, ammonia concentration 10 wt%) to prepare an aqueous solution 2. Then, when the organic mixture 1 and the aqueous solution 2 were mixed and stirred for 3 hours, the resin particles settled in the aqueous phase. The resin particles were taken out by centrifugation. Finally, 0.5 mL of the aqueous solution containing the above resin particles was taken out, ethanol (8 mL) and aqueous ammonia (0.1 mL, 25 wt%) were added, and TEOS (14 μL) was further added. As a result, the light wavelength conversion particles G2 obtained by covering the surface of the resin particles of the light wavelength conversion particles G1 with a silica glass layer having a film thickness of 50 nm were obtained. The average particle size of the light wavelength conversion particles G2 was 3.1 μm.

(Light wavelength conversion particle R2)
In the light wavelength conversion particle R2, the light wavelength conversion particle R2 was obtained by the same procedure as the light wavelength conversion particle G2 except that the light wavelength conversion particle R1 was used instead of the light wavelength conversion particle G1. The average particle size of the light wavelength conversion particles R2 was 3.1 μm.

(Light wavelength conversion particle G3)
Instead of the composition G1 for optical wavelength conversion particles, 90 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), tetraethylene glycol bis (3-mercaptopropionate) ) (Product name "EGMP-4", manufactured by SC Organic Chemical Co., Ltd.) 10 parts by mass, green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particles For optical wavelength conversion particles consisting of 1.0 part by mass (diameter 3.3 nm) and 1 part by mass of thermal radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) The light wavelength conversion particles G3 were obtained by the same procedure as the light wavelength conversion particles G1 except that the composition G2 was used. In the light wavelength conversion particles 3, green emission quantum dots were included in the resin particles, and the average particle size of the light wavelength conversion particles G3 was 3 μm.

(Light wavelength conversion particle R3)
In the optical wavelength conversion particle R3, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) The light wavelength conversion particles R3 were obtained by the same procedure as the light wavelength conversion particles G3 except that the composition R2 for light wavelength wavelength conversion particles containing 1.0 part by mass was used. In the light wavelength conversion particles R3, red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles R3 was 3 μm.

(Light wavelength conversion particle G4)
Instead of composition G1 for optical wavelength conversion particles, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), 50 parts by mass of tert-butyl mercaptan, green emission quantum Dot (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3.3 nm) 1.0 part by mass, and thermal radical polymerization initiator (2,2'- Azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) The light wavelength is the same as that of the light wavelength conversion particles G1 except that the composition G3 for light wavelength conversion particles consisting of 1 part by mass is used. Converted particles G4 were obtained. In the light wavelength conversion particles 4, green emission quantum dots and red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles G4 was 3 μm.

(Light wavelength conversion particle R4)
In the optical wavelength conversion particle R4, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) The light wavelength conversion particles R4 were obtained by the same procedure as the light wavelength conversion particles G4 except that the composition R3 for light wavelength wavelength conversion particles containing 1.0 part by mass was used. In the light wavelength conversion particles R4, red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles R4 was 3 μm.

(Light wavelength conversion particle G5)
Instead of the composition G1 for optical wavelength conversion particles, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), 2-metacloyloxyethyl acid phosphate (product name). "Light ester P-2M", manufactured by Kyoeisha Chemical Co., Ltd., 50 parts by mass, green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3. Composition G4 for light wavelength conversion particles consisting of 1.0 part by mass (3 nm) and 1 part by mass of thermal radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) The light wavelength conversion particles G5 were obtained by the same procedure as that of the light wavelength conversion particles G1 except that the above was used. In the light wavelength conversion particles G5, green emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles G5 was 3 μm.

(Light wavelength conversion particle R5)
In the optical wavelength conversion particle R5, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) The light wavelength conversion particles R5 were obtained by the same procedure as the light wavelength conversion particles G5 except that the composition R4 for light wavelength wavelength conversion particles containing 1.0 part by mass was used. In the light wavelength conversion particles R5, red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles R5 was 3 μm.

(Light wavelength conversion particle G6)
Instead of the composition G1 for optical wavelength conversion particles, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), triphenylphosphine (product name "JC-263") , Johoku Chemical Industry Co., Ltd.) 50 parts by mass, green light emitting quantum dot (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3.3 nm) 1.0 mass Except for the fact that the composition G5 for optical wavelength conversion particles consisting of 1 part by mass and 1 part by mass of a thermal radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used. , The light wavelength conversion particles G6 were obtained by the same procedure as the light wavelength conversion particles G1. In the light wavelength conversion particles G6, green emission quantum dots were included in the resin particles, and the average particle size of the light wavelength conversion particles G6 was 3 μm.

(Light wavelength conversion particle R6)
In the optical wavelength conversion particle R6, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) The light wavelength conversion particles R6 were obtained by the same procedure as the light wavelength conversion particles G6 except that the composition R5 for light wavelength wavelength conversion particles containing 1.0 part by mass was used. In the light wavelength conversion particles R6, red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles R6 was 3 μm.

(Light wavelength conversion particle G7)
Instead of the composition G1 for optical wavelength conversion particles, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), stearylamine (product name "Farmin 80", Kao) 50 parts by mass, green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3.3 nm) 1.0 part by mass, and heat Light wavelength conversion except that the composition G6 for light wavelength conversion particles consisting of 1 part by mass of a radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used. Light wavelength conversion particles G7 were obtained by the same procedure as for particles G1. In the light wavelength conversion particles G7, green emission quantum dots were included in the resin particles, and the average particle size of the light wavelength conversion particles G7 was 3 μm.

(Light wavelength conversion particle R7)
In the optical wavelength conversion particle R7, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) The light wavelength conversion particles R7 were obtained by the same procedure as the light wavelength conversion particles G7 except that the composition R6 for light wavelength wavelength conversion particles containing 1.0 part by mass was used. In the light wavelength conversion particles R7, red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles R7 was 3 μm.

(Light wavelength conversion particle G8)
Instead of composition 1 for optical wavelength conversion particles, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), oleylamine (product name "Amin OB", Nichiyu) 50 parts by mass, green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3.3 nm) 1.0 part by mass, and heat Light wavelength conversion except that the composition G7 for light wavelength conversion particles consisting of 1 part by mass of a radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used. Light wavelength conversion particles G8 were obtained by the same procedure as for particles G1. In the light wavelength conversion particles G8, green emission quantum dots were included in the resin particles, and the average particle size of the light wavelength conversion particles G8 was 3 μm.

(Light wavelength conversion particle R8)
In the optical wavelength conversion particle R8, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) Light wavelength conversion particles R8 were obtained by the same procedure as the light wavelength conversion particles G8 except that the composition R7 for light wavelength wavelength conversion particles containing 1.0 part by mass was used. In the light wavelength conversion particles R8, red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles R8 was 3 μm.

(Light wavelength conversion particle G9)
Instead of the composition G1 for optical wavelength conversion particles, tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), 50 parts by mass, ω-carboxy-polycaprolactone mono (meth) acrylate (Product name "M-5300", manufactured by Toa Synthetic Co., Ltd.) 50 parts by mass, green emission quantum dots (Product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3 .3 nm) 1.0 part by mass and 1 part by mass of thermal radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) for optical wavelength conversion particles. The light wavelength conversion particles G9 were obtained by the same procedure as the light wavelength conversion particles G1 except that G8 was used. In the light wavelength conversion particles G9, green emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles G9 was 3 μm.

(Light wavelength conversion particle R9)
In the optical wavelength conversion particle R9, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) The light wavelength conversion particles R9 were obtained by the same procedure as the light wavelength conversion particles G9 except that the composition R8 for light wavelength wavelength conversion particles containing 1.0 part by mass was used. In the light wavelength conversion particles R9, red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles R9 was 3 μm.

(Light wavelength conversion particle G10)
Instead of the composition G1 for optical wavelength conversion particles, 50 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), 2-acryloyloxyethyl succinic acid (product name "" NK ester A-SA ", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) 50 parts by mass, green emission quantum dots (product name" CdSe / ZnS 530 ", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3" .3 nm) 1.0 part by mass and 1 part by mass of thermal radical polymerization initiator (2,2'-azobis (2,4-dimethylvaleronitrile), manufactured by Tokyo Kasei Kogyo Co., Ltd.) for optical wavelength conversion particles The light wavelength conversion particles G10 were obtained by the same procedure as the light wavelength conversion particles G1 except that G9 was used. In the light wavelength conversion particles G10, green emission quantum dots were included in the resin particles, and the average particle size of the light wavelength conversion particles G10 was 3 μm.

(Light wavelength conversion particle R10)
In the optical wavelength conversion particle R10, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) The light wavelength conversion particles R10 were obtained by the same procedure as the light wavelength conversion particles G10 except that the composition R9 for light wavelength wavelength conversion particles containing 1.0 part by mass was used. In the light wavelength conversion particles R10, red emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles R10 was 3 μm.

(Light wavelength conversion particle G11)
First, 0.2 parts by mass of green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle diameter 3.3 nm) were prepared. After preparing the green emission quantum dots, the surface of the green emission quantum dots was covered with dodecylamine, and these quantum dots were dispersed in a toluene solution (0.4 mL, 1.5 μM / L). Then, tetraethoxysilane (TEOS, 10 μL) was added to this solution, and the mixture was stirred for 3 hours to prepare an organic solution 1.

On the other hand, 3-mercaptopropyltrimethoxysilane (MPS, 1 μL) was mixed with ethanol (25 mL) and aqueous ammonia (4 mL, ammonia concentration 10 wt%) to prepare an aqueous solution 2.

Then, when the organic solution 1 and the aqueous solution 2 were mixed and stirred for 3 hours, the green emission quantum dots and the red emission quantum dots moved to the aqueous phase, and further, an aggregate of the green emission quantum dots and the red emission quantum dots in the aqueous phase. Was formed. This aggregate was removed by centrifugation.

Finally, 0.5 mL of the aqueous solution in which the above aggregates were dispersed was taken out, ethanol (8 mL) and aqueous ammonia (0.1 mL, 25 wt%) were added, and TEOS (14 μL) was further added. As a result, the aggregate composed of green emission quantum dots was wrapped in silica glass to obtain light wavelength conversion particles 11 having an average particle diameter of 50 nm.

(Light wavelength conversion particle R11)
In the optical wavelength conversion particle R11, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) The light wavelength conversion particles R11 were obtained by the same procedure as the light wavelength conversion particles G11 except that 0.2 parts by mass was used. In the light wavelength conversion particles R11, the red emission quantum dots were wrapped in silica glass, and the average particle size of the light wavelength conversion particles R11 was 50 nm.

(Light wavelength conversion particle G12)
Instead of the composition G1 for optical wavelength conversion particles, 100 parts by mass of tricyclodecanedimethanol diacrylate (product name "A-DCP", manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), green emission quantum dots (product name "CdSe / ZnS") 530 ”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3.3 nm) 1.0 part by mass, and thermal radical polymerization initiator (2,2'-azobis (2,4-dimethylvalero) Light wavelength conversion particles G12 were obtained by the same procedure as for the light wavelength conversion particles G1 except that the composition G10 for light wavelength conversion particles consisting of 1 part by mass of nitrile) and 1 part by mass was used. In the light wavelength conversion particles G12, green emission quantum dots were included in the resin particles, and the average particle diameter of the light wavelength conversion particles G12 was 12 μm.

(Light wavelength conversion particle R12)
In the optical wavelength conversion particle R12, instead of the green emission quantum dot, the red emission quantum dot (product name “CdSe / ZnS 610”, manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm. ) The light wavelength conversion particles R12 were obtained by the same procedure as the light wavelength conversion particles G12 except that the composition R10 for light wavelength wavelength conversion particles containing 1.0 part by mass was used. In the light wavelength conversion particles R12, red emission quantum dots were included in the resin particles, and the average particle size of the light wavelength conversion particles R12 was 12 μm.

<Adjustment of curable resin composition>
A curable resin composition was obtained according to the following procedure. First, in the polymerization tank, 63 parts by mass of methyl methacrylate (MMA), 12 parts by mass of acrylic acid (AA), 6 parts by mass of -2-hydroxyethyl methacrylate (HEMA), and 88 parts by mass of diethylene glycol dimethyl ether (DMDG). After the parts were charged, stirred and dissolved, 7 parts by mass of 2,2'-azobis (2-methylbutyronitrile) was added and dissolved uniformly. Then, the mixture was stirred at 85 ° C. for 2 hours under a nitrogen stream, and further reacted at 100 ° C. for 1 hour. To the obtained solution, 7 parts by mass of glycidyl methacrylate (GMA), 0.4 parts by mass of triethylamine, and 0.2 parts by mass of hydroquinone were further added, and the mixture was stirred at 100 ° C. for 5 hours to form an ethylenically unsaturated group. An alkali-soluble resin solution 1 (solid content 50%) having a solid content of 50% was obtained.

Then, the alkali-soluble resin solution 1 was used to obtain a curable resin composition 1 having the following composition.
(Curable resin composition 1)
-Alkali-soluble resin solution 1 (solid content 50%): 58 parts by mass-Dipentaerythritol pentaacrylate (product name "SR399", manufactured by Sartmer): 17 parts by mass-polymerization initiator (product name "Irgacure (registered trademark)) 907 ”, manufactured by BASF Japan Ltd.): 4 parts by mass ・ Diethylene glycol dimethyl ether: 21 parts by mass

<Adjustment of composition for optical wavelength conversion layer>
Each component was blended so as to have the composition shown below to obtain a composition for an optical wavelength conversion layer.
(Composition G1 for Light Wavelength Conversion Layer)
-Tetraethylene glycol bis (3-mercaptopropionate) (product name "EGMP-4", manufactured by SC Organic Chemical Co., Ltd.): 10 parts by mass-Curable resin composition 1 (solid content 50%): 20 parts by mass- Light wavelength conversion particles G 1: 5 parts by mass, acetic acid-3-methoxybutyl: 70 parts by mass

(Compositions for light wavelength conversion layer G2 to G12, R1 to R12)
In the compositions for the light wavelength conversion layer G2 to G12 and R1 to R12, the light wavelength conversion composition is provided except that 5 parts by mass of the light wavelength conversion particles shown in Table 2 are used instead of the light wavelength conversion particles G1. The composition was adjusted in the same manner as in G1.

(Composition G13 for Light Wavelength Conversion Layer)
-Tetraethylene glycol bis (3-mercaptopropionate) (product name "EGMP-4", manufactured by SC Organic Chemical Co., Ltd.): 10 parts by mass-Curable resin composition 1 (solid content 50%): 20 parts by mass- Green emission quantum dots (product name "CdSe / ZnS 530", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 3.3 nm): 0.2 parts by mass, 3-methoxybutyl acetate: 70 Mass part

(Composition R13 for Light Wavelength Conversion Layer)
-Tetraethylene glycol bis (3-mercaptopropionate) (product name "EGMP-4", manufactured by SC Organic Chemical Co., Ltd.): 10 parts by mass-Curable resin composition 1 (solid content 50%): 20 parts by mass- Red emission quantum dots (product name "CdSe / ZnS 610", manufactured by SIGMA-ALDRICH, core: CdSe, shell: ZnS, average particle size 5.2 nm): 0.2 parts by mass, 3-methoxybutyl acetate: 70 Mass part

<Adjustment of composition for light-shielding layer>
First, each component was blended so as to have the composition shown below to obtain a black pigment dispersion liquid 1.
(Black Pigment Dispersion Liquid 1)
-Black pigment: 23 parts by mass-Polymer dispersant (product name "Disperbyk111", manufactured by Big Chemie Japan): 2 parts by mass-Diethylene glycol dimethyl ether: 75 parts by mass

Next, each component was blended so as to have the composition shown below to obtain a light-shielding layer composition 1.
(Composition 1 for light-shielding layer)
・ Black pigment dispersion: 1:61 parts by mass ・ Curable resin composition 1: 20 parts by mass ・ Diethylene glycol dimethyl ether: 30 parts by mass

<Adjustment of composition for blue colored layer>
First, each component was blended so as to have the composition shown below to obtain a blue pigment dispersion liquid 1.
(Blue pigment dispersion liquid 1)
-Blue pigment (CI Pigment Blue 15: 6): 23 parts by mass-Polymer dispersant (product name "Disperbyk111", manufactured by Big Chemie Japan): 2 parts by mass-Diethylene glycol dimethyl ether: 75 parts by mass

Next, each component was blended so as to have the composition shown below to obtain a composition 1 for a blue colored layer.
(Composition for Blue Colored Layer 1)
・ Blue pigment dispersion: 1:61 parts by mass ・ Curable resin composition 1: 20 parts by mass ・ Diethylene glycol dimethyl ether: 30 parts by mass

<Adjustment of composition for green colored layer>
First, each component was blended so as to have the composition shown below to obtain a green pigment dispersion liquid 1.
(Green pigment dispersion liquid 1)
-Green pigment (CI Pigment Green 58): 23 parts by mass-Polymer dispersant (product name "Disperbyk111", manufactured by Big Chemie Japan): 2 parts by mass-Diethylene glycol dimethyl ether: 75 parts by mass

Next, each component was blended so as to have the composition shown below to obtain a composition 1 for a green colored layer.
(Composition for Green Colored Layer 1)
・ Green pigment dispersion: 1:61 parts by mass ・ Curable resin composition 1: 20 parts by mass ・ Diethylene glycol dimethyl ether: 30 parts by mass

<Preparation of composition for red colored layer>
First, each component was blended so as to have the composition shown below to obtain a red pigment dispersion liquid 1.
(Red pigment dispersion liquid 1)
-Red pigment (CI Pigment Red 254): 23 parts by mass-Polymer dispersant (product name "Disperbyk111", manufactured by Big Chemie Japan): 2 parts by mass-Diethylene glycol dimethyl ether: 75 parts by mass

Next, each component was blended so as to have the composition shown below to obtain a composition 1 for a red colored layer.
(Composition for Red Colored Layer 1)
-Red pigment dispersion: 1:61 parts by mass-Curable resin composition 1: 20 parts by mass-Diethylene glycol dimethyl ether: 30 parts by mass

<Preparation of composition for light diffusion layer>
Each component was blended so as to have the composition shown below to obtain a composition 1 for a light diffusion layer.
(Composition 1 for light diffusion layer)
-Tetraethylene glycol bis (3-mercaptopropionate) (product name "EGMP-4", manufactured by SC Organic Chemical Co., Ltd.): 10 parts by mass-Curable resin composition 1 (solid content 50%): 20 parts by mass- Light-scattering particles (crosslinked polystyrene resin particles, product name "SBX-4", manufactured by Sekisui Kasei Kogyo Co., Ltd., average particle diameter 4 μm): 2 parts by mass, 3-methoxybutyl acetate: 70 parts by mass

<Example 1>
First, the light-shielding layer composition 1 is applied on a glass substrate (product name "AN100", manufactured by Asahi Glass Co., Ltd.) having a thickness of 0.7 mm with a spin coater, dried at 100 ° C. for 3 minutes, and has a film thickness of about 2.5 μm. A coating film was formed. Then, this coating film is exposed to a predetermined shape with an ultra-high pressure mercury lamp, developed with a 0.05 wt% potassium hydroxide aqueous solution, and then heat-treated by leaving the substrate in an atmosphere of 180 ° C. for 30 minutes. To form a light-shielding layer having a plurality of openings.

The composition 1 for a blue colored layer was applied onto the substrate on which the light-shielding layer was formed by a spin coating method so as to be inside the opening of the light-shielding layer, and then dried in an oven at 70 ° C. for 3 minutes. Next, a photomask is placed at a distance of 100 μm from the coating film of the composition 1 for the blue colored layer, and ultraviolet rays are applied only to the openings where the blue subpixels should be formed by using a 2.0 kW ultrahigh pressure mercury lamp with a proxymitia liner. Irradiated for 10 seconds. Then, it was immersed in a 0.05 mass% potassium hydroxide aqueous solution (liquid temperature 23 ° C.) for 1 minute for alkaline development, and only the uncured portion of this coating film was removed. Then, the substrate was left in an atmosphere of 180 ° C. for 30 minutes to perform heat treatment to form a blue colored layer having a film thickness of 0.3 μm in the opening in which the blue subpixels should be formed.

Next, using the composition 1 for the green colored layer, a green colored layer having a film thickness of 0.3 μm was formed in the opening in which the green subpixels were to be formed in the same step as the step of forming the blue colored layer. Further, using the composition 1 for the red colored layer, a red colored layer having a film thickness of 0.3 μm was formed in the opening in which the red subpixels should be formed in the same step as the step of forming the blue colored layer.

After forming a colored layer such as a red colored layer, the composition 1 for a light diffusion layer is used in the same step as the step of forming the blue colored layer in the opening where the blue subpixels should be formed and on the blue colored layer. A light diffusion layer having a thickness of 1.9 μm was formed.

Next, using the light wavelength conversion layer composition G1, light wavelength conversion having a thickness of 1.9 μm is performed in the opening where the green subpixels should be formed and on the green colored layer in the same step as the step of forming the blue colored layer. Layer G1 was formed.

Then, using the composition R1 for the light wavelength conversion layer, light wavelength conversion having a thickness of 1.9 μm is performed in the opening where the red subpixels should be formed and on the red colored layer in the same step as the step of forming the blue colored layer. Layer R1 was formed.

Finally, a substrate having a plurality of LED packages in which a blue LED having a emission peak wavelength of 450 nm is arranged in a recess at a position corresponding to each sub-pixel is placed on the OCA layer (product name “Highly transparent adhesive transfer tape 8146-2”). , 3M), and attached to the light diffusion layer, the light wavelength conversion layer G1, and the light wavelength conversion layer R1. As a result, the image display device according to the first embodiment was obtained. The light-shielding layer was in contact with the LED package.

<Examples 2 to 11 and Comparative Examples 1 and 2>
In Examples 2 to 11 and Comparative Examples 1 and 2, Example 1 except that the compositions for each optical wavelength conversion layer shown in Table 2 were used instead of the compositions G1 and R1 for the optical wavelength conversion layer. An image display device was manufactured in the same manner as in the above. In the image display devices according to Comparative Examples 1 and 2, the distance was adjusted so that the distance between the light-shielding layer and the LED package was 20 μm or more.

<Example 12>
In Example 12, the process was the same as in Example 1 until the formation of the light diffusion layer, but after the light diffusion layer was formed, the step of forming the blue colored layer using the light wavelength conversion layer composition G13. In the same step as above, the light wavelength conversion layer G13 having a thickness of 1.9 μm was formed in the opening where the green subpixels should be formed and on the green colored layer. Then, using the light wavelength conversion layer composition R13, light wavelength conversion having a thickness of 1.9 μm is performed in the opening where the red subpixels should be formed and on the red colored layer in the same step as the step of forming the blue colored layer. Layer R13 was formed. Next, after forming the light wavelength conversion layer R13, the composition 1 for the blue colored layer is used in the same step as the step of forming the blue colored layer, in the opening where the green subpixels are to be formed, and the light wavelength conversion layer G1. A blue colored layer having a film thickness of 0.3 μm was formed above and on the light wavelength conversion layer R1 in the opening where the red subpixels should be formed. Then, a glass substrate having a thickness of 0.7 mm (product name "AN100", manufactured by Asahi Glass Co., Ltd.) is in contact with the light diffusion layer, the blue colored layer on the light wavelength conversion layer G1, and the blue colored layer on the light wavelength conversion layer R1. Was pasted.

Finally, a substrate having a plurality of LED packages in which a blue LED having an emission peak wavelength of 450 nm is arranged in a recess at a position corresponding to each sub-pixel is placed on the OCA layer (product name “Highly transparent adhesive transfer tape 8146-2”). It was attached to the glass substrate via 3M). As a result, the image display device according to the twelfth embodiment was obtained.

<Confirmation of specific elements and carboxylic acids in resin particles>
In the light wavelength conversion particles G1 to G10, G12, R1 to R10, and R12, it was confirmed whether or not the above-mentioned specific element or carboxylic acid was detected from the resin particles. Specifically, for the optical wavelength conversion particles G1 to G8, G12, R1 to R8, and R12, the energy dispersive X-ray analyzer (product name "JEM-2800" (equipped with 100 mm ² silicon drift detector (SDD))). , Nippon Denshi Co., Ltd.) under the conditions of an acceleration voltage of 100 kV and a measurement time of 30 seconds, at any position on the surface or inside of the resin particles at a distance of 3 nm or more from the surface of the shell of the quantum dot, sulfur element, phosphorus. It was confirmed whether at least one of the element and the nitrogen element was detected. In addition, for the optical wavelength conversion particles G9, G10, G12, R9, R10, and R12, an infrared microscope (product name "Nicolet iN10", manufactured by Thermo Fisher Scientific) was used to make the quantum dot shell 3 nm or more from the surface of the shell. It was confirmed whether or not the carboxylic acid was detected at an arbitrary position on the surface or inside of the distant resin particles. The confirmation criteria are as follows.
◯: Any of sulfur element, phosphorus element, nitrogen element and carboxylic acid was detected.
X: None of sulfur element, phosphorus element, nitrogen element and carboxylic acid was detected.

<Measurement of content of specific elements>
In the light wavelength conversion particles G1 to G8, G12, R1 to R8, and R12, the content of a specific element contained in the light wavelength conversion particles is determined by a fluorescent X-ray analyzer (product name "EDX-800HS", manufactured by Shimadzu Corporation). Was measured using. The content of the specific element was taken as the average value of the values obtained by measuring three times.

<Measurement of brightness maintenance rate after heat resistance test>
In the image display device according to the above Examples and Comparative Examples, a heat resistance test was performed in which the image display device was left in an environment of 80 ° C. for 500 hours, and the brightness after the heat resistance test with respect to the brightness before the heat resistance test in the image display device. The maintenance rate of was investigated. Specifically, first, the blue LED of the image display device before the heat resistance test is turned on, and the brightness of the light emitted from the display surface of the image display device is measured on the display surface of the image display device in the thickness direction of the image display device. Measurement was performed at a position 400 mm away from the light emitting surface using a spectral radiance meter (product name "CS2000", manufactured by Konica Minolta Co., Ltd.) under the condition of a measurement angle of 1 °.

Next, this image display device was subjected to a heat resistance test in which the image display device was left in an environment of 80 ° C. for 500 hours. Then, the blue LED of the image display device after the heat resistance test is turned on, and the brightness of the light emitted from the display surface of the image display device is 400 mm from the light emitting surface of the display surface of the image display device in the thickness direction of the image display device. Measurements were taken at a distant position using a spectral radiance meter (product name "CS2000", manufactured by Konica Minolta) under the condition of a measurement angle of 1 °.

From these measured luminances, the maintenance rate of the luminance after the heat resistance test with respect to the luminance before the heat resistance test was determined. For the luminance maintenance rate, the luminance retention rate is A, the luminance of the light emitted from the display surface of the image display device before the heat resistance test is B, and the luminance of the light emitted from the display surface of the image display device after the heat resistance test is B. Was C, and it was calculated by the following formula.
A = C / B × 100

The results are shown in Tables 1 and 2 below.

The results will be described below. As can be seen from Table 2, in the image display devices according to Examples 1 to 11, the optical wavelength conversion particles 1 to 10 in which quantum dots are contained in the resin particles containing at least one of a specific element and a carboxylic acid and the like. Since the light wavelength conversion particles 11 in which the quantum dots are contained in the barrier particles are used, the image display device according to Comparative Example 1 which does not use the resin particles themselves or the barrier particles themselves or the resin particles containing the quantum dots are used. However, the brightness retention rate after the heat resistance test was higher than that of the image display device according to Comparative Example 2 in which the resin particles did not contain any specific element or carboxylic acid. Further, in the image display device according to Example 12, although resin particles and barrier particles were not used, since the glass substrates were arranged on both sides of the light wavelength conversion layer, the brightness maintenance rate after the heat resistance test was high.

In the light wavelength conversion particles G1 to 8 and R1 to 8, the content of the specific element measured by fluorescent X-ray analysis was 0.5% by mass or more. On the other hand, in the light wavelength conversion particles 12, the content of the specific element measured by fluorescent X-ray analysis was less than 0.5% by mass. In the light wavelength conversion particles G12 and R12, although the composition for light wavelength conversion particles G10 and R10 used for forming the light wavelength conversion particles G12 and R12 do not contain a specific element, they are specified. It is considered that the reason why the content of the element of is 0.17% by mass and 0.15% by mass, respectively, is that the quantum dot itself contains a sulfur component.

In the above embodiment, CdSe is used as the core material of the green emission quantum dots and the red emission quantum dots, but even if a non-Cd material such as InP or InAs is used as the core material, the same result as in the above embodiment is obtained. was gotten.

10, 100, 120, 150 ... Image display device 20 ... Light source 23 ... Light emitting element 24 ... Package 24A ... Recess 30 ... Shading layer 30A ... Openings 40, 45, 110, 115, 130, 135, 160, 165 ... Optical wavelength conversion Layers 41, 46, 111, 116 ... Light wavelength conversion particles 41A, 46A ... Quantum dots 41B, 46B ... Resin particles 60, 65, 170, 175 ... Colored layers 111A, 116A ... Barrier particles

Claims (2)

A light source with one or more light emitting elements and
A pair of barrier members arranged so as to face each other on the observer side of the light emitting element,
A light-shielding layer arranged between the barrier members and having an opening at a position corresponding to the light-emitting element,
An optical wavelength conversion layer arranged in the opening and containing quantum dots and a binder resin,
A first colored layer arranged in the aperture and on the observer side of the light wavelength conversion layer, transmitting light wavelength-converted by the quantum dots, and absorbing light from the light emitting element.
Equipped with
An image display device in which the barrier member on the light source side is made of glass or is made of a light-transmitting base material and a barrier layer made of an inorganic oxide. A second colored layer provided between the barrier member on the light source side and the light wavelength conversion layer, which transmits light from the light emitting element and absorbs light wavelength-converted by the quantum dots, is further provided. The image display device according to claim 1 .

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