WO2006046607A1

WO2006046607A1 - Dispersion type electroluminescence element

Info

Publication number: WO2006046607A1
Application number: PCT/JP2005/019702
Authority: WO
Inventors: Tadanobu Sato
Original assignee: Fujifilm Corporation
Priority date: 2004-10-29
Filing date: 2005-10-26
Publication date: 2006-05-04

Abstract

An electroluminescence (EL) element containing, in the following order, a transparent electrode, a phosphor layer, a dielectric layer and a back electrode, characterized in that the dielectric layer comprises dielectric particles and a color conversion material, wherein (1) the dielectric layer contains the color conversion material in a specific content and said dielectric layer has a specific thickness, or (2) the color conversion material has a luminous local maximum wave length in the range of 600 to 750 nm. The above electroluminescence element is a dispersion type electroluminescence element which emits a white light and is excellent in color rendering property, in particular, color rendering property for a red color.

Description

Specification

Dispersive electoluminescence device

Technical field

[0001] The present invention relates to a dispersive electoluminescent device having a light emitting particle layer formed by dispersing and applying electoluminescent phosphor particles.

Background art

[0002] Electric mouth luminescence (hereinafter also referred to as "EL") phosphors are voltage-excited phosphors, and are used as distributed EL devices in which phosphor particles are sandwiched between electrodes. It is known. The general shape of a dispersion-type EL device is a structure in which phosphor particles are dispersed in a high-dielectric-constant inductor, and at least one is sandwiched between two transparent electrodes. Light is emitted by applying an alternating electric field between the electrodes. Dispersed EL devices with such a structure can be made to a thickness of lmm or less, and it is possible to form flexible and lightweight devices on plastic substrates without using high-temperature processes in the manufacturing process. It can be manufactured at a low cost with a relatively simple process without using a vacuum device, and has many advantages such as being a surface light emitter. Applications are possible, specifically road signs, lighting for various interiors and exteriors, and light sources for flat panel displays such as liquid crystal displays.

There is a use as an illumination light source for advertising in a large area.

[0003] Application power as a light source of a dispersion-type EL element White color is desirable, but since there is no phosphor that emits white light alone, there are various types of dispersion-type EL elements for obtaining white light. Technology has been proposed. Dispersion EL elements that have been proposed to emit white light have a light emission waveform in which the light emission intensity is concentrated mainly in the two wavelength regions of blue-green and orange to red. As described above, these dispersive EL elements that emit white light have various advantages as a flexible planar light source, and have a color rendering property, particularly a red color rendering property, compared to other white light sources such as fluorescent lamps. There was a serious problem in that it was greatly inferior. For example, when a transmissive medium such as a transparent positive image is placed on an EL element and observed, the red color reproducibility is greatly inferior to the case where a conventional fluorescent light is used as a flat light source, and almost red is expressed. It was impossible.

[0004] For example, many of the conventional dispersion-type ELs have been used as white light-emitting EL elements by putting a rhodamine-based compound in a light-emitting particle layer (for example, Patent Documents 1 to 3). In these EL devices, orange light emission derived from the light emission of rhodamine compounds is used as red light emission. However, although these EL devices emit white light, they have the power to reproduce red when a transmission medium such as a transparent positive image is placed.

[0005] Further, there has been proposed a technique for obtaining EL elements having different emission colors by providing a color conversion layer or a pigment layer above the phosphor layer (transparent electrode side: viewing side) (for example, Patent Documents 4 and 5). etc). Furthermore, there is a technology for obtaining a red light-emitting EL device by laminating a color conversion layer that has a complementary relationship with the emission color of the light-emitting particle layer and a red filter that passes only a wavelength near 600 nm above the light-emitting particle layer. It has been proposed (Patent Document 6). However, even with these technologies, sufficient red reproducibility (red color rendering) could not be obtained.

[0006] On the other hand, in Patent Document 7, an EL element containing a photoexciter in any one of the layers constituting the EL element has been proposed.

Patent Document 1: Japanese Patent Laid-Open No. 60-25195

Patent Document 2: JP-A-60-170194

Patent Document 3: Japanese Patent Laid-Open No. 2-78188

Patent Document 4: JP-A-6-163159

Patent Document 5: Japanese Patent Laid-Open No. 3-15191

Patent Document 6: Japanese Patent Laid-Open No. 11-67456

Patent Document 7: Japanese Patent Laid-Open No. 11-67458

Disclosure of the invention

Problems to be solved by the invention

[0007] An object of the present invention is to obtain a dispersed EL element that emits white light and has excellent color rendering properties, particularly red color rendering properties.

Means for solving the problem

[0008] Conventional dispersive EL devices emit white light, but in all cases, the wavelength of red light is short wave (orange light emission), and red color reproduction when a transparent medium or other transmissive medium is placed Sex (red Color rendering) was extremely bad. The present inventors noticed that the red color reproducibility is poor in the conventional technology, because the conventional dispersion-type EL element hardly contains the wavelength of the original red light. In order to improve the performance, we thought that it was necessary to increase the emission wavelength of the red light component during white light emission from orange to red.

In the dispersive EL element, a color conversion material that emits red light is used in addition to phosphor particles that emit blue-green light to produce white light emission. In a conventional dispersion-type EL device, a pigment obtained by dispersing an organic dye in a polymer and pulverizing it into particles is used as a red color conversion material dispersed in a light emitting particle layer (hereinafter also referred to as a phosphor layer). However, when the emission wavelength of the pigment is measured in such a state that the pigment is dispersed in the medium, it shifts to a shorter wavelength side than the emission wavelength when measured with the pigment powder. This shift toward the short wavelength side reduces red color reproducibility.

[0010] In order to prevent the shift to the short wavelength side described above, the present inventors add a pigment to the dielectric layer, and use the light scattering of the dielectric particles that occurs in the dielectric layer, thereby making the pigment It has been found that the self-absorption of can be increased and the apparent emission wavelength can be increased. This long wave is obtained by (1) high red reproducibility that is particularly large when the pigment content in the dielectric layer is within a specific range and the thickness of the dielectric layer is within a specific range. I found out that In addition, similar findings could be obtained for other color conversion materials such as dyes. Furthermore, (2) it has been found that high red reproducibility can be obtained even when the emission maximum wavelength of the color conversion material contained in the dielectric layer is 600 nm or more and 750 nm or less. Furthermore, we have found that by providing a dielectric layer containing a color conversion material below the phosphor layer, it is possible to obtain an EL device that maintains the brightness while minimizing light absorption from EL emission. Based on these findings, the present inventors have found that an EL element having the following configuration can achieve the above object, and has completed the present invention.

[0011] On the other hand, conventional EL devices are insufficient in durability, and there is a demand for the development of EL devices with excellent durability in which the decrease in emission brightness due to deterioration of phosphor particles is small. It is. As one of the measures to improve the durability of EL elements, EL elements that maintain white and good color rendering for a long time and maintain brightness by preventing moisture from touching phosphor particles I came to get. That is, the present invention has the following configuration.

(1) An electoluminescence device containing a transparent electrode, a phosphor layer, a dielectric layer, and a back electrode in this order, and

The dielectric layer includes dielectric particles and a color conversion material, the content ratio of the color conversion material is 0.1% by mass or more and 20% by mass or less with respect to the dielectric particles, and the thickness of the dielectric layer is An electroluminescent device having an aperture of 1 μm to 20 μm.

(2) An electorium luminescence device containing a transparent electrode, a phosphor layer, a dielectric layer and a back electrode in this order, and

The electroluminescent device, wherein the dielectric layer includes dielectric particles and a color conversion material, and the emission maximum wavelength of the color conversion material is not less than 600 nm and not more than 750 nm

(3) In an electoluminescence device containing a transparent electrode, a phosphor layer, a dielectric layer and a back electrode in this order, the dielectric layer contains dielectric particles and a color conversion material, and the color conversion material The maximum emission wavelength is 600 nm or more and 750 nm or less, the content ratio of the color conversion material is 0.1% by mass or more and 20% by mass or less with respect to the dielectric particles, and the thickness of the dielectric layer is 1 _μm or more. An electoluminescence device having a size of 20 μm or less.

(4) The electroluminescent device according to (3), wherein the color conversion material is a material in which an organic compound is dispersed in a polymer.

(5) An electoluminescence device comprising a transparent electrode, a phosphor layer, a dielectric layer and a back electrode in this order, wherein the phosphor layer includes phosphor particles having a coating layer (1 The electoluminescence device according to any one of (4) to (4).

(6) The coating layer has a wavelength of 280ηπ! The electoluminescence device according to (5), comprising a material having an absorption edge at ˜420 nm.

(7) It has two emission maxima in the visible range, of which the short wave side emission maxima is in the range of 480 nm to 510 nm, and the long wave side emission maxima is in the range of 590 nm to 625 nm, (1) to (6), wherein the emission minimum is in the range of 571 nm to 583 nm. (8) The phosphor particles have an average particle size of 0.1 to 20 / zm, a variation coefficient of particle size distribution of less than 35%, and containing 10 or more layers of stacking faults with a spacing of 5 nm or less. The electroluminescent device according to any one of (5) to (7), wherein the electroluminescent phosphor is a ZnS-based electroluminescent phosphor having 30% by volume or more of the entire phosphor particles. The invention's effect

[0013] According to the EL element of the present invention, it is possible to obtain a dispersed EL element that emits white light and has excellent color rendering properties, particularly red color rendering properties.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the EL element of the present invention will be described in detail.

The EL device of the present invention contains a transparent electrode, a phosphor layer, a dielectric layer, and a back electrode in this order.

[0015] <Dielectric layer>

The dielectric layer includes dielectric particles and a color conversion material.

(1) The content ratio of the color conversion material is 0.1% by mass or more and 20% by mass or less with respect to the dielectric particles, and the thickness of the dielectric layer is 1 μm or more and 20 μm or less.

Or (2) the dielectric layer includes dielectric particles and a color conversion material, and the emission maximum wavelength of the color conversion material is not less than 600 nm and not more than 750 nm.

With the above configuration, a dispersed EL element that emits white light and has excellent color rendering properties, particularly red color rendering properties, can be obtained.

In the above (1), the content ratio of the color conversion material contained in the dielectric layer is 0.1% by mass or more and 20% by mass or less, preferably 0.1% by mass with respect to the dielectric particles as described above. The range is from 5% by mass to 10% by mass.

The thickness of the dielectric layer containing the color conversion material is 1 m or more and 20 m or less as described above, and preferably 3 μm or more and 18 μm or less.

By setting the content ratio of the color conversion material contained in the dielectric layer and the thickness of the dielectric layer within the above ranges, the EL element can realize white color emission and high color rendering. In the above (2), the emission maximum wavelength of the color conversion material is 600 nm or more and 750 nm or less as described above, preferably 610 nm or more and 650 nm or less, more preferably 61 The range is from Onm to 630 nm.

By setting the light emission maximum wavelength of the color conversion material contained in the dielectric layer within the above range, the EL device can achieve high color rendering with white light emission.

Further, as described above, the EL device of the present invention contains a transparent electrode, a phosphor layer, a dielectric layer, and a back electrode in this order, and the color conversion material is below the phosphor layer (on the back electrode side). By installing it in the EL, it is possible to minimize light absorption and maintain brightness

With the above-described configuration, the peak wavelength of red light emission during white light emission of the dispersion-type EL element can be within a preferable range of 590 nm to 625 nm, and the peak wavelength of blue-green light emission is from 480 to 480 nm. It can be 510nm. Further, at this time, the minimum value between the blue-green light emission band and the red light emission band can be set in the range of 571 nm to 583 nm. The red light emission peak wavelength is more preferably in the range of 595 nm to 620 nm, and most preferably 600 nm to 615 nm. The emission peak wavelength of blue-green light emission is more preferably 483 nm to 505 nm, and more preferably 485ηπ! ~ 503nm.

[0017] If the EL element of the present invention has layers in the above order, other layers described later can be provided.

In the present invention, in addition to the above-described dielectric layer containing the color conversion material (hereinafter also referred to as color conversion material-containing dielectric layer or dielectric layer A), the dielectric layer further does not contain a color conversion material. (Hereinafter also referred to as dielectric layer B. The number “dielectric layer B—number” represents the position of dielectric layer B in the EL element.). For example, a dielectric layer A and a dielectric layer B can be stacked to form an EL device having the order of transparent electrode, phosphor layer, dielectric layer A, dielectric layer B, and back electrode. Furthermore, the dielectric layer B is provided on both sides of the dielectric layer A, and the transparent electrode, the phosphor layer, the dielectric layer B-1, the dielectric layer A, the dielectric layer B-2, and the back electrode are arranged in this order. The EL element can be provided. Furthermore, the dielectric layer B is provided on the side opposite to the dielectric layer A (transparent electrode side) across the phosphor layer, and the transparent electrode, dielectric layer B-3, phosphor layer, dielectric layer A and An EL element with the order of the back electrodes can be obtained.

When the dielectric layer B is included in addition to the dielectric layer A, the total thickness of the entire dielectric layer For example, the thickness is preferably 5 μm or more and 40 μm or less, more preferably 5 μm or more and 35 m or less. When the dielectric layer B is provided on both sides of the dielectric layer A, the thickness of the dielectric layer B-1 provided on the phosphor layer side is preferably m or more and 10 m or less, more preferably 7 μm or less. It is.

[0018] The color conversion material-containing dielectric layer A includes dielectric particles and a color conversion material. In the present invention, the color conversion material is substantially contained only in the color conversion material-containing dielectric layer A. “Substantially contained only in the dielectric layer A containing the color conversion material” means that 70% by mass or more of the color conversion material contained in the EL element is contained in the dielectric layer A. When the fluorescent pigment used as the color conversion material has low resistance to the dispersion solvent, the dielectric layer A must contain 1Z2 or more of the dye contained in the fluorescent pigment before being added to the dispersion solvent. However, the color conversion material is substantially contained in the dielectric layer A. Further, the color conversion material is substantially uniformly contained in the color conversion material-containing dielectric layer A. The phrase “substantially uniformly contained” means that molecules and pigment particles of a color conversion material having a concentration gradient when viewed as a whole layer are contained in a state where the distribution as a whole is not biased. At this time, the color conversion material molecules and particles may exist in a state where a plurality of molecules and particles are gathered as long as they are contained substantially uniformly as a whole layer.

[0019] [Dielectric particle]

The color conversion material-containing dielectric layer A is formed including dielectric particles.

The dielectric particles can be formed by using any dielectric material that has a high dielectric breakdown voltage and a high dielectric breakdown voltage, and has a high reflectance. Such materials are selected from metal oxides and nitrides, such as TiO, BaTiO, Sr

twenty three

TiO, PbTiO, KNbO, PbNbO, Ta O, BaTa O, LiTaO, Y O, Al O, Zr

3 3 3 3 2 3 2 6 3 2 3 2 3

O, AION, ZnS etc. are mentioned. The average size of the dielectric particles is the average particle size.

2

It is preferably 2.0 μm or less, more preferably 0.01 μm or more and 1.0 μm or less, and most preferably 0.05 m or more and 0.5 m or less. Similarly to the color conversion material-containing dielectric layer A, the dielectric layer B containing no color conversion material can be formed including dielectric particles. As the dielectric particles, the same or different particles may be used for the color conversion material-containing dielectric layer A and the dielectric layer B not containing the color conversion material. [0020] [Color conversion material]

As the color conversion material used for the color conversion material-containing dielectric layer A, a fluorescent pigment or a fluorescent dye can be preferably used. These may be used in combination. Among these compounds that form the emission center, rhodamine, latathone, xanthene, quinoline, benzothiazole, triethylindoline, perylene, triphenine, and compounds having skeletons of dicyanomethylene are preferred, as well as cyanine dyes, It is also preferable to use an azo dye, a polyphenylene vinylene polymer, a disilane oligochelene polymer, a ruthenium complex, a europium complex, or an erbium complex. These compounds may be used alone or in combination.

In the embodiment of (1), it is also preferable to use a color conversion material having an emission maximum wavelength of 600 nm or more and 750 nm or less. Such a configuration is preferable because the color rendering property of red is further improved.

Further, these compounds may be used after further being dispersed in a polymer or the like.

[0021] [Binder]

The dielectric particles are preferably dispersed in a binder. Examples of binders include polymers having a relatively high dielectric constant, such as cyanoethyl cellulose resin, and resins such as polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy resin, and vinylidene fluoride. Is preferred. As a method for dispersing the dielectric particles, it is preferable to use a homogenizer, a planetary kneader, a single kneader, an ultrasonic disperser, or the like.

[0022] The dielectric layer B that does not contain a color conversion material can also be formed as a uniform film. Further, as described above, it can be formed including dielectric particles. Alternatively, a combination of these may be used. “The film is uniform” means that the dielectric layer itself is an amorphous layer or a layer having a crystalline structure. Examples of the uniform film include a layer having only a high dielectric constant binder and a thin film crystal layer. When the dielectric layer B is formed as a uniform film, the thickness is preferably in the range of 0.1 μm to 10 μm.

[0023] When the dielectric layer is formed by coating, it is preferable to use a slide coater or an etrusion coater. In the case of a thin film crystal layer, sputtering, vacuum evaporation, etc. A thin film formed by a vapor phase method or a sol-gel film using an alkoxide such as Ba or Sr may be used.

[0024] When forming the dielectric layer A and when forming the dielectric layer B including dielectric particles, it is preferably formed by applying a coating liquid for forming a dielectric layer. The dielectric layer forming coating solution is a coating solution containing at least dielectric particles, a binder, and a solvent for dissolving the binder. The coating liquid for forming the dielectric layer A further contains a color conversion material. Here, examples of the solvent include the same solvents as those used for the phosphor layer.

[0025] The viscosity of the coating liquid for forming a dielectric layer is preferably in the range of 0.1 Pa's to 5 Pa's, and more preferably in the range of 0.3 Pa's to 1. OPa's. If the viscosity of the coating liquid for forming the dielectric layer is within the above range, the film thickness unevenness of the coating is difficult to occur, and the dielectric particles do not separate and settle with the passage of time after dispersion. Application is also possible and preferable. The viscosity is a value measured at 16 ° C. which is the same as the coating temperature.

[0026] <Phosphor layer>

The phosphor layer is formed including phosphor particles.

[Phosphor particles]

As the phosphor particles preferably used in the present invention, particles prepared by various preparation methods such as firing by mixing a base material, an activator and, if necessary, a coactivator are used. The matrix material used in this case is specifically a group force consisting of Group II elements and Group VI elements, or a group consisting of one or more elements selected from Group III elements and Group V elements. Fine particles of a semiconductor composed of one or a plurality of elements selected from the above, and are arbitrarily selected depending on the necessary emission wavelength region. Examples thereof include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, CaS, MgS, SrS, GaP, GaAs, and mixed crystals thereof. ZnS, CdS, CaS, and the like can be preferably used. Furthermore, the base material of the particles includes BaAlS, CaGaS, GaO, ZnSiO, ZnGaO, ZnGaO, ZnGeO, ZnGeO,

2 4 2 4 2 3 2 4 2 4 2 4 3 4

ZnAl O, CaGa O, CaGeO, Ca Ge O, CaO, Ga O, GeO, SrAl O, Sr

2 4 2 4 3 2 2 7 2 3 2 2 4

Ga O, SrP O, MgGa O, Mg GeO, MgGeO, BaAl O, Ga Ge O, BeGa

2 4 2 7 2 4 2 4 3 2 4 2 2 7

O, Y SiO, Y GeO, Y Ge O, Y GeO, YO, YOS, SnO and their Mixed crystals and the like can also be preferably used.

As the activator, metal ions such as Mn and Cu and rare earth elements can be preferably used.

Moreover, as a coactivator added as necessary, halogen elements such as CI, Br, and I, A1 and the like can be preferably used.

Furthermore, in the present invention, it is more preferable to use the following phosphor particles.

(a) Phosphor particles whose average particle size (sphere equivalent diameter) force is in the range of 0.1 m or more and 20 μm or less and the variation coefficient of the particle size is less than 35%.

(b) A phosphor particle having an average particle size of 0.1 μm or more and 20 μm or less, and containing 10 or more layers of stacking faults with a spacing of 5 nm or less inside the particle.

(c) The phosphor particle according to any one of (a) and (b), which is coated with a non-light-emitting shell layer having a thickness of 0.01 μm or more.

(d) The phosphor particles according to any one of (a) to (c), wherein the activator is at least one ion selected from copper, manganese, silver, gold, and a rare earth element.

(e) The phosphor particles according to any one of (a) to (d), wherein the coactivator is at least one ion selected from chlorine, bromine, iodine, and aluminum.

(f) The phosphor particle according to any one of (a) to (e), wherein the activator is copper ion and the coactivator is chloride ion.

[0028] In particular, in the present invention, it is preferable to use the following phosphor particles.

The phosphor particles preferably have an average particle size in the range of 0.1 to 20 / ζ πι, more preferably 1 to 15 / ζ πι in order to reduce the thickness of the phosphor layer and increase the electric field strength. In order to increase the uniformity of light emission and the filling rate of the phosphor particles in the phosphor layer, the coefficient of variation in particle size is preferably less than 35%, more preferably less than 30%. The inside of the particles has a structure with many planar stacking faults, and the efficiency of light emission is high. Therefore, the number of particles having stacking faults of 10 layers or more with an average spacing of stacking faults of 5 nm or less. Is preferably 30% or more of the total number of phosphor particles, more preferably 50% or more, and even more preferably 70% or more.

The phosphor particles are preferably a ZnS-based electoluminescence phosphor. Use of the phosphor particles as described above is preferable because deterioration due to ultraviolet rays can be further reduced and durability can be improved.

The phosphor particles that can be used in the present invention can be formed by a firing method (solid phase method) widely used in the industry. For example, in the case of zinc sulfate, a fine particle powder (usually called raw powder) with a crystallite size of lOnm or more and 50nm or less is prepared by the liquid phase method, and this is used as the primary particle, which is called an activator. Impurities are mixed, and particles are obtained by first firing in a crucible with a flux at a high temperature in the range of 900 ° C to 1300 ° C for 30 minutes to 10 hours. The intermediate phosphor particles obtained by the first firing are repeatedly washed with ion-exchanged water to remove alkali metal, alkaline earth metal, excess activator and coactivator. Next, second baking is performed on the obtained intermediate phosphor particles. In the second baking, heating (annealing) is performed at a temperature lower than that of the first baking in the range of 500 to 800 ° C, and in a short time of 30 minutes to 3 hours. Although many stacking faults are generated in the phosphor particles by these firings, the conditions for the first firing and the second firing are set so that fine particles and more stacking faults are included in the phosphor particles. It is preferable to select appropriately. Also, by applying an impact force in a certain range to the intermediate phosphor particles, the density of stacking faults without destroying the particles can be greatly increased. The impact force can be applied by contacting and mixing the intermediate phosphor particles, mixing and mixing spheres such as alumina (ball mill), accelerating and colliding the particles, and applying ultrasonic waves. A method or the like can be preferably used. After that, etching with an acid such as HC1 removes the metal oxides adhering to the surface, and the copper sulfide adhering to the surface is removed by washing with KCN and dried to obtain phosphor particles. .

In addition, it is preferable to use a hydrothermal synthesis method, a urea melting method, or a spray pyrolysis method as a method for forming phosphor particles that can be used in the present invention. Further, a laser 'ablation method, a CVD method, a plasma method is used. Vapor phase methods such as CVD method, sputtering, resistance heating, electron beam method, fluid oil surface vapor deposition combined method, etc., double decomposition method, precursor thermal decomposition method, reverse micelle method and these methods and high temperature firing It can also be formed using a combination of these methods, a liquid phase method such as freeze-drying.

[0030] [Coating layer] It is also preferred that the phosphor particles used in the present invention include phosphor particles having a coating layer formed by forming a coating layer on the surface of the core particle as the phosphor particles. The average thickness of the coating layer is preferably from 0.01 to m, and more preferably from 0.05 to 0.5 m. Here, the average film thickness of the coating layer is measured from three cross-sectional SEM photographs of the phosphor particles on which the coating layer was formed. The average value.

When the average film thickness of the coating layer is within the above range, good moisture proofing and ion barrier properties can be obtained, as well as a decrease in luminance and an increase in emission threshold voltage without reducing the electric field strength to the phosphor particles. It is preferable because it is difficult to cause.

In addition, it is preferable that the coating layer has a thickness suitable for the average size of the particles. For example, when a 1 μm coating layer is formed on a 1 μm particle, the electric field strength to the particles is reduced. Easy to cause. Therefore, the ratio of the average film thickness of the coating layer to the average particle size of the particles is preferably in the range of 0.001 to 0.1, and more preferably in the range of 0.002 to 0.05. Good.

[0031] The composition of the coating layer is not particularly limited, but oxides, nitrides, hydroxides, fluorides, phosphates, diamond-like carbon, and organic compounds can be used. The use of a membrane or the like is also preferable. Specifically, SiO, Al 2 O, TiO, ZrO, HfO

2 2 3 2 2 2

, Ta O, Y O, La O, CeO, BaTiO, SrTiO, PZT, Si N, A1N, Al (OH),

2 5 2 3 2 3 2 3 3 3 4 3

MgF, CaF, Mg (PO), Ca (PO), Sr (PO), Ba (PO), fluororesin, etc.

2 2 3 4 2 3 4 2 3 4 2 3 4 2

preferable.

[0032] The coating layer improves the luminous efficiency of the phosphor particles and reduces the deterioration over time. It also provides moisture resistance and ion barrier properties. In addition, by providing a coating layer, it may be possible to add an effect on ultraviolet absorption. As a result, the degradation power over time S can be further reduced, and the color balance deviation can be reduced. preferable. From the viewpoint of ultraviolet absorption, the coating layer has a wavelength of 280ηπ! Those containing a material having an absorption edge at ˜420 nm are preferred.

Examples of such a material include the following materials.

0 The coating material itself absorbs ultraviolet rays (TiO, ZnO, CeO, ZrO, My power, force In the case where the coating layer is formed of olin, sericite, etc., an ultraviolet absorption effect can be obtained simply by coating.

ii) The coating material itself does not absorb ultraviolet light (Al 2 O

2 3, SiO, etc.)

2

UV-absorbing effects can be obtained by further laminating a cinnamate, cinnamic acid, paraaminobenzoic acid, camphor, benzophenone or benzoylmethan UV absorber.

[0033] The coating layer is preferably continuous without pinholes or cracks in order to obtain sufficient moisture resistance and ion barrier properties. Such a coating layer can be formed by using a liquid phase synthesis method such as a sol-gel method, a precipitation method, etc., but a CVD method using a fluidized bed, a stirring bed, a vibrating bed, a rolling bed, etc., a plasma More preferably, it is formed by a CVD method, a sputtering method, a mechanofusion method, or the like.

[0034] The coating layer in the present invention can be formed, for example, by the following method.

As a first method of forming the coating layer, there is a method of forming the coating layer by supplying the raw material of the coating layer and depositing or reacting on the particle surface in a state where the phosphor particle core particles are fluidized.

[0035] Fluidization of the phosphor particle core particles can be performed by appropriately adopting a known method, and examples thereof include a method using a fluidized bed, a stirring bed, a vibrating bed, and a rolling bed. For example, as shown in FIG. 1, the fluidized bed is filled with phosphor particle core particles in a cylindrical container, and floats and flows the phosphor particle core particles filled with the carrier gas introduced through the perforated plate from the bottom of the container. For example, as shown in FIG. 2, the stirring bed is a method of directly fluidizing the filled phosphor particle core particles with an impeller stirrer, etc., and the vibrating bed is shown in FIG. 3, for example. In this method, the phosphor particle core particles filled in the container are mechanically or electrically vibrated together with the container, and the rolling bed is, for example, a cylinder installed in a horizontal or inclined position as shown in FIG. In this method, EL phosphor core particles filled in a container are fluidized by rotating a cylindrical container.

[0036] In particular, in order to obtain a uniform and continuous coating layer, it is preferable to use a fluidized bed. Here, as the phosphor particle size becomes smaller, the tendency to aggregate becomes stronger and fluidization becomes difficult. Therefore, a fluidization accelerator having a particle size larger than that of the phosphor particle core particle is added to the phosphor particle core particle. It is preferable to add. The particle size of the fluidization accelerator is a phosphor particle nucleus. It is preferably about 2 to 5 times the average particle size of the child. As the fluidization accelerator, phosphor particles and substances that are inert at the reaction temperature are preferred. For example, SiO, Al 2 O, ZrO, etc. are preferably used.

2 2 3 2

It can be done.

The shape of the fluidization accelerator is preferably a spherical shape having the best fluidity.

[0037] Supply and reaction of the coating layer material to the surface of the fluidized phosphor particle core particle may be performed by, for example, reacting a carrier gas containing a gaseous coating layer raw material and introducing it in the same route or another route. Can be used on the particle surface. At this time, the coating layer can be formed by thermally decomposing the gaseous coating layer raw material without using the reaction gas. As the raw material for the gaseous coating layer, alkoxides, alkyl compounds, chlorides, hydrides, hydrocarbons, and the like can be used. The temperature of each reaction apparatus is usually a temperature in the range of about 100 to 500 ° C. In order to reduce thermal damage to the phosphor particles, the temperature is preferably 300 ° C or less. It is also preferable to supply the liquid coating layer raw material to the fluidized bed by a method such as spraying.

[0038] A coating layer of oxide, nitride, hydroxide, diamond-like carbon, or the like can be formed by the above method. For example, a TiCl solution can be vaporized by publishing with N gas to contain water vapor.

4 2

TiO precursor coating layer is formed by reacting with N gas and phosphor particle core particle surface

twenty two

A1N coating layer can be formed by the reaction of alkylaluminum and anhydrous ammonia gas.

[0039] As a second method of forming the coating layer, the phosphor particle core particles are dispersed in a solvent.

And a method of forming a coating layer by supplying a raw material of the coating layer and depositing or reacting on the particle surface.

In this method, the phosphor particle core particles can be introduced into a reaction vessel together with a solvent and dispersed using an impeller stirrer or the like. The reaction vessel is preferably cylindrical, and the bottom of the vessel is preferably conical or hemispherical. The shape of the stirring blade can be a screw type, a twisted blade type, a paddle type, or the like, but it is more preferable to use a screw-paddle composite type that can form a stirring flow in a direction perpendicular to the circumferential direction of the stirring shaft. . As shown in Fig. 5, it is preferable to provide a stirrer blade strainer to create a stronger vertical stirring flow. As the solvent, water, an organic solvent, or a mixture thereof can be preferably used. wear. As a special solvent, urea melted by heating to the melting point or higher can also be used. Furthermore, it is also preferable to add a dispersing agent such as a surfactant in the solvent.

[0040] In the formation of the coating layer in the solvent, the coating layer raw material is dissolved in the solvent in which the phosphor particle core particles are dispersed, and the reaction solution is added thereto to form the coating layer on the particle surface. The method or the method of simultaneously adding the coating layer raw material solution and the reaction solution to the solvent in which the phosphor particle core particles are dispersed can be preferably used. At this time, the coating layer raw material solution and the reaction solution are preferably added to the region where stirring is most intensely performed. As a method for adding the coating layer raw material solution and the reaction solution, it is preferable to use a syringe pump with a small amount of pulsation of the pumped liquid that can use a known quantitative pump or calorie with an orifice. In adding the coating layer raw material solution and the reaction solution, it is preferable to individually control the addition rate of each solution by detecting the ion concentration in the reaction vessel. When the solvent is urea, the reactant is not limited to a solution, and can be added as a solid.

[0041] The reaction temperature can also be controlled by directly heating the reaction vessel with a mantle heater or the like. By providing a jacket around the reaction vessel and supplying hot or cold water. It is preferable to control. The reaction temperature is preferably in the range of 40 to 80 ° C. when the solvent is water or an organic solvent, and is preferably in the range of 130 to 150 ° C. in the case of urea. Moreover, it is also preferable from the viewpoints of densification of the coating layer and promotion of decomposition'condensation reaction that these are all reacted under pressure by using a force autoclave which is a reaction under normal pressure. In this case, the reaction temperature can be used up to a critical temperature exceeding 100 ° C. It is preferable to add the solution into the autoclave using a liquid feed pump having a pressure resistance equal to or higher than the autoclave internal pressure.

[0042] A coating layer of oxide, hydroxide, phosphate, fluoride, or the like can be formed by the above method. For example, phosphor particles are dispersed in an alcohol solution of titanium alkoxide, and water diluted with alcohol as a reaction solution is added in an amount equivalent to about 10 times that of titanium alkoxide, so that the Ti O precursor coating layer becomes phosphor particle core particles. Can be formed on the surface. Na (PO) aqueous solution

By dispersing phosphor particles in 2 3 4 and adding MgCl aqueous solution as reaction solution, Mg (PO

2 3 4

) A coating layer can be formed on the phosphor particle core particle surface, and an alcohol solution of Mg (CH COO)

2 3 2

Disperse phosphor particles in the solution and add CF COOH diluted with alcohol as the reaction solution. By doing so, the MgF coating layer can be formed on the surface of the phosphor particle core particle.

2

[0043] In addition to the above two coating layer forming methods, it is also preferable to anneal after the forming process.

Annealing can be almost completely converted to an acidic product, such as when a partially oxidized hydroxide is generated, and the denseness of the coating layer is improved to improve moisture resistance and ion barrier properties. To do.

[0044] As a third method of forming the coating layer, there is a method of forming the coating layer by applying mechanical thermal energy in a state where the phosphor particle core particles and the coating layer material are mixed. The coating layer material can be solidified on the surface of the phosphor particle core particle by receiving mechanical thermal energy due to impact or friction. As a device for applying such mechanical thermal energy, a hybridizer, a sheeter composer, or the like can be preferably used. As the coating material, it is preferable to use an organic compound such as high molecular weight resin, but an inorganic compound is also possible. It is also preferable to form a coating layer of an organic compound and then form a multilayer coating layer of the inorganic compound or coat with a mixture of an organic compound and an inorganic compound.

[0045] The phosphor layer can be formed by applying a phosphor particle-containing coating solution. The phosphor particle-containing coating solution is a coating solution containing at least phosphor particles, a binder, and a solvent for dissolving the binder. As the binder, use is made of a polymer having a relatively high dielectric constant, such as cyanoethylcellulose resin, or a resin such as polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy resin, or vinylidene fluoride. I prefer that. To these binders, fine particles with high dielectric constant such as BaTiO and SrTiO are added.

3 3

The dielectric constant can be adjusted by mixing 5 to 50 parts by mass with respect to parts by mass. As a dispersion method, a homogenizer, a planetary kneader, a roll kneader, an ultrasonic disperser, or the like can be used. The solvent can be used without limitation as long as it is a highly polar solvent, and alcohols, ketones, esters, polyhydric alcohols and derivatives thereof, plasticizers, and the like can be preferably used.

[0046] The viscosity of the coating solution containing phosphor particles is preferably in the range of 0.1 Pa's to 5 Pa's, and more preferably in the range of 0.3 Pa's to 1. OPa's. Viscosity and strength of coating solution containing phosphor particles If it is within the above range, coating film thickness unevenness hardly occurs, and phosphor particles do not separate and settle with the passage of time after dispersion. Is also possible and preferred. Na The viscosity is a value measured at 16 ° C. which is the same as the coating temperature.

[0047] The phosphor layer has a dry film thickness of 0.5 m or more and 30 m or less on a plastic support or the like provided with a transparent electrode, using a slide coater or an etrusion coater. It is preferable to apply continuously so that At this time, the thickness variation of the phosphor layer is preferably 12.5% or less, particularly preferably 5% or less.

When the phosphor layer is thinned, the voltage applied to the phosphor layer is higher under the same driving conditions than when the phosphor layer is thick like the conventional EL element, and the luminance is increased. When driving with the same level of brightness as a conventional EL device, the drive voltage and frequency can be lowered, reducing power consumption and further improving vibration and noise. In order to obtain such an effect, the phosphor layer has a thickness of 0.5 / z m or more and 70 m or less, more preferably 10 μm or more and 60 μm or less.

[0048] As described above, the phosphor particles used in the present invention are preferably particles having an average particle diameter in the range of 0.1 µm to 20 µm. Within this range, even when the phosphor layer is 30 m or less, the layer can be formed uniformly, which is preferable. The filling rate of the phosphor particles in the phosphor layer is not limited, but is preferably in the range of 60% by mass to 95% by mass, more preferably in the range of 70% by mass to 90% by mass. In one embodiment of the present invention, by setting the particle size of the phosphor particles to 20 m or less, the uniformity of the coating film thickness of the phosphor layer is improved and the smoothness of the coating film surface is simultaneously improved. Furthermore, since the number of particles per unit area is greatly increased, the fine emission unevenness can be remarkably improved. Furthermore, the decrease in the particle size leads to an increase in the voltage applied to the phosphor particles, and in addition to an increase in the electric field strength to the phosphor layer due to the thin phosphor layer, it is preferable for improving the brightness of the EL element. It is also preferable for suppressing vibrations that cause noise.

[0049] Cu Electrode>

As the transparent electrode used in the EL device of the present invention, an electrode formed using any commonly used transparent electrode material is used. Examples of transparent electrode materials include tin oxides such as tin-doped oxide tin, antimony-doped tin oxide, and zinc-doped oxide oxide tin, a multilayer structure in which a silver thin film is sandwiched between high refractive index layers, and poly-phosphorus. And π-conjugated polymers such as polypyrrole. The transparent electrode has a fine metal such as comb or grid. U, also preferred to improve the conductivity by placing the wire.

The specific resistivity of the transparent electrode is preferably in the range from 0.01 Ω to 30 Ω. The back electrode is the side from which light is not extracted, and any conductive material can be used. For example, it can be selected from metal such as gold, silver, platinum, copper, iron, and aluminum, graphite, and the like according to the form of the element to be created, the temperature of the creation process, and the like. A transparent electrode such as ITO may be used if it is conductive.

In addition, for both the transparent electrode and the back electrode, a conductive material-containing coating solution in which the conductive fine particle material is dispersed together with a binder may be prepared and applied using a slide coater or an etatrusion coater. it can.

[0050] <Others>

In addition, in the element configuration of the present invention, various protective layers, filter layers, light scattering reflection layers, and the like can be provided as necessary.

In the EL device of the present invention, it is preferable to dispose a transparent electrode on a support. As the support that can be used in this case, any support that is flexible and highly transparent can be used without limitation. Preferred are plastic films such as PET (polyethylene terephthalate), PES (polyethersulfone), PAr (polyarylate), PC (polycarbonate), and PEN (polyethylene naphthalate).

[0051] Each functional layer coated on the support is preferably formed as a continuous process including at least a coating step and a drying step. The drying process is divided into a constant rate drying process until the coating film is dried and solidified, and a decreasing rate drying process for reducing the residual solvent of the coating film. In the present invention, since the binder ratio of each functional layer is high, when rapidly dried, only the surface is dried, convection is generated in the coating film, so-called Benard cell is likely to occur, and pre-expansion due to rapid solvent expansion. Star failure is likely to occur, and the uniformity of the coating is significantly impaired. On the other hand, if the final drying temperature is low, the solvent remains in each functional layer, affecting the subsequent processes for forming EL elements such as a moisture-proof film laminating process. Therefore, it is preferable that the drying process is performed slowly at a constant rate, and is performed at a temperature sufficient for the solvent to dry. As a method of slowly performing the constant rate drying process, the drying chamber where the support travels is divided into several zones, and the drying temperature after the coating process is increased stepwise. It is preferable.

In the manufacture of the EL device of the present invention, the phosphor layer may be subjected to a calendar process using a calendar processor. The smoothness of both main surfaces of the phosphor layer formed by calendering is preferably in the range of 0.5 / zm or less, more preferably 0.2 / zm or less. Force to be used The render processing machine is not particularly limited, and can be appropriately selected from the known powers of known devices. Smoothing treatment is performed by passing a phosphor layer in which phosphor particles are dispersed in a binder while applying pressure between a pair of rolls heated at least one of, for example, 50 ° C to 200 ° C. It is something to apply. In the calendering process, the heating temperature of the calender roll is preferably not less than the softening temperature of the binder contained in the phosphor layer. In addition, the calender pressure and the conveyance speed are set to the required smoothness, taking into account the calender temperature and the coating width of the phosphor layer so as not to break the phosphor particles or extend the phosphor layer more than necessary. It is preferable to select as appropriate so as to obtain.

[0053] The conductive material described above can also be used when a compensation electrode is provided to suppress vibration of the EL element. For example, when a compensation electrode is provided outside the transparent electrode from which light is extracted, an oxide such as tin-doped tin oxide, antimony-doped tin oxide, or zinc-doped ichtin tin, or a silver thin film is formed with a high refractive index layer. It is preferable to use transparent electrode materials such as sandwiched multilayer structures, π-conjugated polymers such as polyaline and polypyrrole.

[0054] Further, when a compensation electrode is provided outside the back electrode without extracting light, any conductive material such as metal such as gold, silver, platinum, copper, iron, aluminum, or graphite may be used. Although it can be used, a transparent electrode such as a bag may be used as long as it has conductivity. The compensation electrode is attached to the transparent electrode and the back electrode through an insulating layer. The insulating layer material is an insulating inorganic material or polymer material, a dispersion liquid in which inorganic material powder is dispersed in a polymer material, or the like. Can be formed by vapor deposition or coating. In addition, a conductive material-containing coating solution in which the conductive fine particle material is dispersed together with a binder can be prepared and applied using a slide coater or an etatrusion coater. Furthermore, an insulating material-containing coating solution in which the insulating material is dispersed together with a binder can be prepared and applied simultaneously with the conductive material-containing coating solution. A voltage is applied to the compensation electrode provided from the drive power source, and at this time, the vibration generated in the phosphor layer can be canceled by setting the phase opposite to the voltage applied to the phosphor layer. Supplement The compensation electrode has the same effect even if it is attached outside the transparent electrode or outside the back electrode with an insulating layer sandwiched between them. However, if one is attached and grounded at the same time, further vibration suppression is achieved. Since an effect can be expected, it is preferable. In order to effectively suppress vibration, it is preferable to adjust the dielectric constant of the phosphor layer (and dielectric layer) and the dielectric constant of the insulating layer inside the compensation electrode to be substantially the same! /.

[0055] As another method for suppressing vibration of the EL element, when a buffer material layer used for the EL element is provided, the buffer material layer is foamed by adding a polymer material having a high impact absorbing ability or a foaming agent. It is preferable to use high polymer materials. Examples of the polymer material having high impact absorbing ability include natural rubber, styrene butadiene rubber, polyisoprene rubber, polybutadiene rubber, nitrile rubber, chloroprene rubber, butyl rubber, hibaron, silicon rubber, urethane rubber, ethylene propylene rubber, and fluorine rubber. Etc. can be used. The hardness of these polymer materials is preferably 50 or less, more preferably 30 or less, from the viewpoint of vibration absorption ability. In addition, butyl rubber, silicon rubber, fluororubber, and the like are more preferable because they have a low water absorption and function as a protective film for protecting the EL element from moisture. It is also preferable to use as a buffer material a material obtained by adding a foaming agent to the above rubber material, polypropylene, polystyrene, or polyethylene resin. The buffer material layer using these buffer materials can be attached by adhering the buffer material layer to the EL element with an adhesive, but the buffer material is dissolved in a solvent to prepare a buffer material-containing coating solution, It can also be applied using a slide coater or an etrusion coater. Although the thickness of the buffer layer depends on the hardness of the polymer material, it needs to be 20 μm or more and preferably 50 μm or more in order to sufficiently absorb vibration. If it exceeds 200 μm, the thickness of the element increases greatly, which is not preferable in terms of mass and flexibility. Further, the combined use of the compensation electrode and the buffer layer is preferable because it can further suppress vibration.

[0056] The dispersion-type EL element of the present invention is preferably processed using a sealing film so as to eliminate the influence of humidity and oxygen from the external environment. Sealing the fill arm for sealing the EL element is preferably water vapor transmission rate of 0. 05gZm ² Zday less at 40 ° C- 90% RH, 0. 01gZm 2 Zday less is more preferable. Further 40 ° C-oxygen permeability at 90% RH is 0. lcm ³ Zm ² ZdayZatm is preferably less instrument 0. 01cm ³ Zm ² ZdayZatm less is more preferable. As such a sealing film, a laminated film of an organic film and an inorganic film is preferable. Used.

As a material for forming the organic film, polyethylene-based resin, polypropylene-based resin, polycarbonate-based resin, polyvinyl alcohol-based resin, and the like are preferably used, and polyvinyl alcohol-based resin can be more preferably used. . Since polyvinyl alcohol resins and the like have water absorption properties, it is more preferable to use those that have been completely dried by intensive treatment such as vacuum heating. An inorganic film is deposited by vapor deposition, sputtering, CVD method, etc. on a material obtained by processing such a resin into a sheet by a method such as coating. As the inorganic film to be deposited, silicon oxide, silicon nitride, silicon oxynitride, acid silicate, zinc oxyaluminum, aluminum nitride or the like is preferably used. In order to obtain a lower water vapor transmission rate and oxygen transmission rate, and to prevent the inorganic film from cracking due to bending, etc., the formation of the organic film and the inorganic film is repeated, or the organic film deposited with the inorganic film is used as the adhesive layer. It is preferable to laminate a plurality of films through a multi-layer film. The thickness of the organic material film is preferably in the range of 5 m to 300 m, more preferably in the range of 10 m to 200 m. The thickness of the inorganic film is preferably in the range of lOnm or more and 300 nm or less, and more preferably in the range of 20 nm or more and 200 nm or less. The film thickness of the laminated sealing film is preferably in the range of 30 m to 1000 m, more preferably in the range of 50 μm to 300 μm. For example, in order to obtain a sealing film with a water vapor transmission rate of 0.05 gZm ² Zday or less at 40 ° C—90% RH, ^two layers of the above organic film and inorganic film are laminated. In 50 ~: L00 μm film thickness The polychlorinated trifluoride titanium conventionally used as a sealing film requires a film thickness of 200 m or more. The thinner the sealing film, the better in terms of light transmission and device flexibility.

When sealing an EL cell with this sealing film, even if the EL cell is sandwiched between two sealing films and sealed, the sealing film overlaps by folding one sealing film in half The part may be adhesively sealed. For the EL cell sealed with the sealing film, only the EL cell may be prepared separately, or the EL cell may be directly formed on the sealing film. In this case, the support can be used instead. The sealing step is preferably performed in a dry atmosphere with vacuum or dew point control. [0058] Even when an advanced sealing process is performed, it is preferable to dispose a desiccant layer around the EL cell. As the desiccant used in the desiccant layer, alkaline earth metal oxides such as CaO, SrO, BaO, acid aluminum, zeolite, activated carbon, silica gel, paper and highly hygroscopic resin are preferably used. In particular, alkaline earth metal oxides are more preferable in terms of moisture absorption performance. These hygroscopic agents can be used even in powder form. For example, the hygroscopic agent can be used by mixing it with a resin material and processing it into a sheet by coating or molding, or by applying a coating liquid mixed with the resin material. It is preferable to dispose the desiccant layer by applying it around the EL element using a dispenser or the like. Furthermore, it is more preferable to cover not only the periphery of the EL cell but also the lower and upper surfaces of the EL cell with a desiccant. In this case, it is preferable to select a highly transparent desiccant layer for the light extraction surface. As the highly transparent desiccant layer, polyamide-based resin can be used.

Example 1

Hereinafter, the EL device of the present invention will be described in more detail based on examples, but the present invention is not limited to the following examples.

[0060] “Preparation of EL device by conventional technology” (Comparative Example 1 1)

30 mass BaTiO of fine particles having an average particle size of 0. 2 μ m ^_0/0 Xia Roh ethyl cell row

Three

The solution dispersed in the glass solution was applied onto a 75 μm thick aluminum sheet so that the layer thickness was 30 μm and dried at 110 ° C. for 5 hours to obtain an aluminum sheet on which a dielectric layer was formed. Subsequently, copper / chlorine-activated zinc sulfate particles having an average particle size of 15 m and 30% by weight of cyanethyl cellulose solution were mixed and dispersed at a ratio of 1.2: 1, and further manufactured by Sinloihi Add 3% by weight of red pigment (Sinroich FA-001) to the zinc oxide particles and disperse it, and apply it on the aluminum sheet on which the above-mentioned dielectric layer is formed so that the final layer thickness is 45 μm. Then, it was dried at 110 ° C. for 5 hours using a hot air dryer to form a pigment-containing phosphor layer.

A film in which ITO was uniformly deposited to a thickness of 40 nm on a 100 micron thick polyethylene terephthalate by sputtering was produced, and this ITO surface and the surface on which the pigment-containing phosphor layer of the aluminum sheet was formed were thermocompression bonded. Then, the lead piece was placed, sealed with a moisture-proof film, and the EL element of Comparative Example 1-1 was obtained.

[0061] "Preparation of EL device by conventional technology" (Comparative Example 1 2) An EL device of Comparative Example 1-2 was obtained in the same manner as Comparative Example 1 except that the red pigment was changed to Sinloich FA-007.

[0062] "Preparation of EL device by conventional technology" (Comparative Example 1 3)

Three

The solution dispersed in the glass solution was coated on a 75 μm thick aluminum sheet so that the layer thickness was 20 μm and dried at 110 ° C. for 5 hours to obtain an aluminum sheet on which a dielectric layer was formed. Subsequently, BaTiO fine particles having an average particle size of 0.2 μm were mixed with 30 mass% cyanoethyl cellulose.

Three

Disperse in the solution, and then add and disperse the red pigment (Sinloihi FA-007) made by Sinloi to 8% of the mass of BaTiO and disperse the resulting layer to a final layer thickness of 10 / zm.

Three

In the same manner, it was applied to the aluminum sheet on which the dielectric layer was formed, and dried again at 110 ° C. for 5 hours to form a pigment-containing dielectric layer. Subsequently, zinc sulfate particles activated with copper and chlorine having an average particle size of 15 m and 30 mass% cyanoethylcellulose solution were mixed and dispersed at a ratio of 1.2: 1, and further a red pigment ( FA-007) was added and dispersed in 3% by weight with respect to zinc oxide particles, and applied onto an aluminum sheet on which the above-mentioned pigment-containing dielectric layer was formed so that the final layer thickness was 45 m. The pigment-containing phosphor layer was formed by drying at 110 ° C. for 5 hours using a hot air dryer.

A film in which ITO was uniformly deposited to a thickness of 40 nm on a 100 micron thick polyethylene terephthalate by sputtering was produced, and this ITO surface and the surface on which the pigment-containing phosphor layer of the aluminum sheet was formed were thermocompression bonded. Then, the lead piece was placed, sealed with a moisture-proof film, and the EL element of Comparative Example 1-3 was obtained.

[0063] "Creation of EL device according to the present invention (1-1)"

Three

In the same way, apply to the aluminum sheet on which the above dielectric layer is formed, and dry again at 110 ° C for 5 hours. A material-containing dielectric layer was formed. Further, after mixing and dispersing copper / chlorine-activated zinc particles having an average particle size of 15 m and a 30 mass% cyanoethylcellulose solution in a ratio of 1.2: 1, a pigment-containing dielectric The phosphor layer was applied to an aluminum sheet on which the layer had been formed so that the thickness of the phosphor layer was 45 m, and dried at 110 ° C. for 5 hours using a hot air dryer to form a phosphor layer.

A film in which ITO is uniformly deposited to a thickness of 40 nm on a 100-micron polyethylene terephthalate film by sputtering is produced, and the ITO surface and the surface on which the phosphor layer of the aluminum sheet is formed are thermocompression bonded. The EL element (1-1) according to the present invention was obtained by placing the piece and sealing it with a moisture-proof film.

[0064] “Production of EL device according to the present invention (1)”

Three

Disperse it in a solution, and then add a red pigment that emits light at 620 nm to this dispersion.

Add to and disperse to 6% of 3, and apply to the aluminum sheet on which the above-mentioned dielectric layer is formed so that the final layer thickness is 10 m, and dry again at 110 ° C for 5 hours to contain the pigment A dielectric layer was formed. Furthermore, the average硫I spoon zinc particles and 30 mass particles size was activated with copper and chlorine 15 m ^_0/0 of Xia Roh cellulose solution 1.2: 1 after mixing 'dispersed in a ratio, pigment-containing dielectric The phosphor layer was formed by coating the aluminum sheet with the body layer so that the final layer thickness was 45 μm and drying at 110 ° C. for 5 hours using a hot air dryer.

A film in which ITO is uniformly deposited to a thickness of 40 nm on a 100-micron polyethylene terephthalate film by sputtering is produced, and the ITO surface and the surface on which the phosphor layer of the aluminum sheet is formed are thermocompression bonded. The EL element (1-II) according to the present invention was obtained by placing a piece and sealing it with a moisture-proof film.

[0065] "Production of EL device according to the present invention (1 111)"

The EL device of the present invention was produced except that Lumogen F Red 200 (BASF) was used as the red light emitting material instead of the red pigment so as to be 5% of the mass of BaTiO (1 An EL device (1-III) according to the present invention was obtained in the same manner as II).

[0066] "Production of EL device according to the present invention (1 IV)"

Three

A red pigment that emits light at 620 nm.

3) Add and disperse the solution to 6% of the amount so that the layer thickness is 15 m.Apply it on a 75 m thick aluminum sheet and dry it at 110 ° C for 5 hours to form the pigment-containing dielectric layer. A formed aluminum sheet was obtained. Further, the average particle size of 15 / zm copper and硫I chlorine was activated spoon zinc particles and 30 mass ^_0/0 of Xia Roh cellulose solution 1.2: After mixing 'was dispersed in 1 ratio, pigment-containing It was applied to an aluminum sheet with a dielectric layer so that the final layer thickness was 45 μm, and dried at 110 ° C for 5 hours using a hot air dryer to form a phosphor layer.

A film in which ITO is uniformly deposited to a thickness of 40 nm on a 100-micron polyethylene terephthalate film by sputtering is produced, and the ITO surface and the surface on which the phosphor layer of the aluminum sheet is formed are thermocompression bonded. A piece was placed and sealed with a moisture-proof film to obtain an EL device (1 IV) according to the present invention.

[0067] “Production of EL device according to the present invention (1—V)”

30 mass BaTiO of fine particles having an average particle size of 0. 5 μ m ^_0/0 Xia Roh ethyl cell row

Three

The solution dispersed in the glass solution was applied onto a 75 μm thick aluminum sheet so that the layer thickness was 15 m, and dried at 110 ° C. for 5 hours to obtain an aluminum sheet on which a dielectric layer was formed. Subsequently, BaTiO fine particles having an average particle size of 0.5 μm were mixed with 30 mass% cyanoethyl cellulose.

Three

Disperse it in a solution, and then add a red pigment that emits light at 610 nm to this dispersion.

Add to and disperse to 2.8% of 3, and apply to the aluminum sheet on which the above dielectric layer is formed so that the final layer thickness is 15 m, then dry again at 110 ° C for 5 hours, and pigment A containing dielectric layer was formed. Furthermore, the average硫I匕亜lead particles and 30 mass particles size was activated with copper and chlorine 15 m ^_0/0 of Xia Roh cellulose solution 1.2: After mixing 'was dispersed in 1 ratio, pigment-containing It was applied to an aluminum sheet with a dielectric layer so that the final layer thickness was 45 m and dried at 110 ° C for 5 hours using a hot air dryer to form a phosphor layer. A film in which ITO was uniformly deposited to a thickness of 40 nm by sputtering on polyethylene terephthalate having a thickness of 100 microns was fabricated. The ITO surface and the phosphor layer of the aluminum sheet were formed. The EL element (1-V) according to the present invention was obtained by thermocompression bonding with the surface on which the lead was formed, placing a lead piece and sandwiching and sealing with a moisture-proof film.

[0068] "Production of EL device according to the present invention (1 VI)"

Three

The solution dispersed in the glass solution was coated on a 75 m thick aluminum sheet so that the layer thickness was 10 m and dried at 110 ° C. for 5 hours to obtain an aluminum sheet on which a dielectric layer was formed. Subsequently, BaTiO fine particles having an average particle size of 0.5 μm were mixed with 30 mass% cyanoethyl cellulose.

Three

Add to and disperse to 0.8% of 3, and apply to the aluminum sheet on which the above-mentioned dielectric layer is formed so that the final layer thickness is 20 m, and then dry again at 110 ° C for 5 hours. A containing dielectric layer was formed. Furthermore, the average硫I匕亜lead particles and 30 mass particles size was activated with copper and chlorine 15 m ^_0/0 of Xia Roh cellulose solution 1.2: After mixing 'was dispersed in 1 ratio, pigment-containing It was applied to an aluminum sheet with a dielectric layer so that the final layer thickness was 45 m and dried at 110 ° C for 5 hours using a hot air dryer to form a phosphor layer. A film in which ITO is uniformly deposited to a thickness of 40 nm on a 100-micron polyethylene terephthalate film by sputtering is produced, and the ITO surface and the surface on which the phosphor layer of the aluminum sheet is formed are thermocompression bonded. The EL element (1-VI) according to the present invention was obtained by placing the piece and sealing it with a moisture-proof film.

[0069] "Production of EL device according to the present invention (1 VII)"

Three

Disperse in the solution, and then add a red pigment that emits light at 630 nm to this dispersion.

Add to and disperse to 6% of 3, and apply to the aluminum sheet on which the above-mentioned dielectric layer is formed so that the final layer thickness is 15 m, and dry again at 110 ° C for 5 hours to contain the pigment A dielectric layer was formed. Further, the average particle size of 15硫I spoon zinc particles and 30 mass ^_0/0 copper and chlorine were activated in m Xia Roh cellulose solution 1.2: 1 ratio 'after dispersing, It was applied to an aluminum sheet with a pigment-containing dielectric layer so that the final layer thickness would be 45 μm, and dried at 110 ° C for 5 hours using a hot air dryer to form a phosphor layer.

A film in which ITO is uniformly deposited to a thickness of 40 nm on a 100-micron polyethylene terephthalate film by sputtering is produced, and the ITO surface and the surface on which the phosphor layer of the aluminum sheet is formed are thermocompression bonded. The EL element (1 VII) according to the present invention was formed by placing the piece and sealing it with a moisture-proof film.

Table 1 shows the color rendering properties of the EL element of the present invention prepared as described above and the EL element of the comparative example when emitted at 100 V and 1 kHz.

[0071] [Table 1] Sample Average color rendering index (Ra) R9 (color rendering properties of red) R15 (skin color of Japanese women) Comparative Example 1 1 1 64 -102 45 Comparative Example 1 2 69 4 74 Comparative Example 1 3 65 9 63 EL element of the present invention (1-1) 76 38 87 EL element of the present invention (1-11) 76 89 85 EL element of the present invention (1-1 II) 74 72 84 EL element of the present invention ( 1-IV) 81 60 83 EL element of the present invention (1-V) 78 58 80 EL element of the present invention (1-VI) 72 46 79 EL element of the present invention (1-VI 1) 83 90 88

Comparative Examples 1 1 to 1 3 and EL elements (1 I) to (1 VII) of the present invention had a white emission color. It can be seen that the average color rendering index Ra of the EL element of the present invention is superior to the conventional EL element of the comparative example, and particularly excellent in the color rendering property R9 of red. It can be seen that the skin color rendering R15 is greatly improved in the EL device of the present invention. R15 cannot be expressed well when the color rendering property R9 of red is poor, and is an important factor when observing a transmission medium such as a transparent positive image on an EL element.

Example 2

[0073] Each phosphor particle of Example 1 was provided with an Al 2 O coating layer using a fluidized bed reactor using trimethyl aluminum as a raw material and O as a reaction gas. Layer thickness of coating layer

2 2 3

Was 170 nm. Except for using this particle as the phosphor layer particle, all Each element of Example 2 was prepared in the same manner as Example 1, and used as a comparative example and an EL element of the present invention, respectively.

For these EL devices, a 1 kHz AC electric field was applied, the voltage was adjusted so that the initial luminance was 300 cd / m ^{2 at} 25 ° C and a relative humidity of 60%. The luminance half-life is 15-20% longer. Regarding the change in the color rendering index, the change of the average color rendering index was about 5 in the comparative example, which was reduced by about 10, and improved by about 6 in the present invention.

Industrial applicability

[0074] As described above, the electoluminescence device that is effective in the present invention emits white light and has excellent color rendering properties, particularly red color rendering properties, and is suitable for use as a backlight or a display device.

Brief Description of Drawings

[0075] FIG. 1 is a schematic explanatory diagram of a fluidized bed reactor for forming a coating layer on phosphor particles.

FIG. 2 is a schematic explanatory diagram of a stirred bed reaction apparatus for forming a coating layer on phosphor particles.

FIG. 3 is a schematic explanatory diagram of a vibrating bed reactor for forming a coating layer on phosphor particles.

FIG. 4 is a schematic explanatory diagram of a rolling bed reactor for forming a coating layer on phosphor particles.

FIG. 5 is a schematic explanatory diagram of a liquid phase reaction apparatus for forming a coating layer on phosphor particles.

Claims

The scope of the claims

[1] An electroluminescent element containing a transparent electrode, a phosphor layer, a dielectric layer, and a back electrode in this order, and

[2] An electroluminescent element containing a transparent electrode, a phosphor layer, a dielectric layer, and a back electrode in this order, and

[3] In an electroluminescent element containing a transparent electrode, a phosphor layer, a dielectric layer, and a back electrode in this order, the phosphor layer includes phosphor particles having a coating layer. The electoluminescence device according to 1 or 2.

[4] The coating layer has a wavelength of 280ηπ! The electoluminescence device according to claim 3, comprising a material having an absorption edge at ˜420 nm.

[5] It has two emission maxima in the visible range, of which the short wave side emission maxima is in the range of 480 nm to 510 nm, and the long wave side emission maxima is in the range of 590 nm to 625 nm. The electoric luminescence device according to any one of claims 1 to 4, wherein the emission minimum is in the range of 571 nm to 583 nm.

[6] The above phosphor particles have an average particle size of 0.1 to 20 μm, a variation coefficient of the particle size distribution of less than 35%, and particles containing 10 or more layers of stacking faults with a spacing of 5 nm or less 6. The electroluminescent device according to claim 3, wherein the electroluminescent device is a ZnS-based electroluminescent phosphor having 30% by volume or more of the entire phosphor particles.