JP2005228670A - Distributed electroluminescent device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distributed EL device which inhibits deterioration by ultraviolet rays of fluorescent pigment and coloring at nonluminescence, and to provide its manufacturing method by which the EL device is manufactured easily and simply, without increase in the manufacturing processes of the distributed EL device. <P>SOLUTION: The distributed electroluminescent device includes at least a transparent electrode, a light-emitting layer with EL fluorescent material particles distributed, a dielectric layer, and a backplate, in this order. The fluorescent pigment which converts a part of luminescence from the EL fluorescent material particles into another wavelength is distributed in the light-emitting layer. Its distribution of content of the fluorescent pigment is adjusted to be higher at a backplate side in a thickness of closer in the direction of the light-emitting layer, or the fluorescent pigment, which converts a part of luminescence from the EL fluorescent material particles into another wavelength, is distributed in the dielectric layer, and its distribution of content of the fluorescent pigment is adjusted to be higher, closer it is to the side of the light emitting layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a dispersion type electroluminescent device having a light emitting layer in which electroluminescent phosphor particle powder is dispersedly applied and a method for manufacturing the same.

  Electroluminescent (hereinafter, also referred to as “EL”) phosphor particles are voltage-excited EL phosphor particles, and a dispersion type EL device in which an EL phosphor particle powder is sandwiched between electrodes and used as a light emitting device is known. ing. The general shape of a dispersion-type EL element is a structure in which an EL phosphor particle powder is dispersed in a high dielectric constant binder and sandwiched between two electrodes, at least one of which is transparent. It emits light by applying an alternating electric field to. A light emitting device made using EL phosphor particle powder can have a thickness of several millimeters or less, is a surface light emitter, and has many advantages such as low heat generation, so it can be used for road signs, various interiors and exteriors. There are uses as a light source for a flat panel display such as a liquid crystal display, an illumination light source for a large area advertisement, and the like.

  Dispersed EL elements do not use high-temperature processes, so it is possible to form flexible elements using plastic as a substrate, and they can be manufactured at low cost in a relatively simple process without using a vacuum device. In addition, it has the feature that the light emission color of the element can be easily adjusted by mixing a plurality of EL phosphor particles having different light emission colors, and is applied to backlights and display elements such as LCDs. However, since the light emission luminance and efficiency are low and a high voltage of 100 V or higher is necessary for high luminance light emission, the application range is limited, and further improvement of light emission luminance and light emission efficiency is desired.

  As a means for increasing the light emission luminance or a means for decreasing the light emission voltage, a method of increasing the electric field in the EL phosphor particle layer by reducing the film thickness of the EL phosphor particle layer is widely known. However, in general, when the EL phosphor particles are 20 μm or more, an attempt to apply a smooth EL phosphor particle layer will result in unevenness when the film thickness is suppressed to 60 μm or less, resulting in a decrease in the withstand voltage performance and lifetime of the device. Decrease and non-uniformity of light emission occurs. On the other hand, it is well known that the reduction in size of the particles leads to a decrease in luminance. In particular, in the case of particles having a size of less than 5 μm, the EL phosphor particle layer can be made thin, but it has high luminance and high efficiency. It is well known in the industry that it is incompatible with

  As EL phosphor particle powders, those in which an activator such as copper (metal ion as a light emission center) and a coactivator such as chlorine are added using zinc sulfide as a base material are widely known. However, this light emitting device has the disadvantages that the light emission luminance is low and the light emission life is short compared to the light emitting device based on other principles, and various improvements have been tried so far. Was not enough. These EL phosphor particles are usually irregular particles having a particle size of 20 μm or more. For example, as described in Patent Documents 1 and 2, the raw material zinc sulfide particles are mixed with an inorganic salt called a flux at 1000 ° C. There is a method of obtaining zinc sulfide particles for EL having high luminous efficiency by performing first baking at a very high temperature of ˜1300 ° C. to grow particles and subsequently performing second baking at 500 ° C. to 1000 ° C. It was mainstream. The conventional firing method cannot take a growth mode in which nucleation and growth are separated, and particle convection in the growth crucible cannot be expected. Therefore, it is easily affected by locality of temperature and atmosphere, and the size increases. At the same time, the particle size distribution becomes wider. That is, the particles that grow with growth grow larger, and the smaller particles grow slower and the distribution spreads. As a result, the inter-particle distribution of the light emission characteristics is increased, and it tends to be difficult to obtain high luminance unless a high voltage is applied.

  In addition, in the conventional EL element manufacturing method, several methods for forming a light emitting layer containing EL phosphor particles are disclosed. There is a screen printing method as the most commonly used method, but in order to use a screen mesh, film thickness unevenness of the coating film and multiple times of application to obtain the required film thickness are inefficient. There's a problem. Furthermore, when applying a dielectric layer, the dielectric layer is laminated after the light emitting layer is applied, so that it is necessary to wait for the light emitting layer to dry, or the screen mesh must be replaced. Efficiency. Also, there is a limit in increasing the area. A doctor blade method is disclosed as a continuous application method of the light emitting layer (see, for example, Patent Document 3). However, this method has a problem that the coating liquid film surface before drying is scraped off with a doctor blade, so that coating film failure such as uneven film thickness and streaks is likely to occur.

  Further, the light emission of the EL element is determined by the light emission wavelength of the EL phosphor particles contained in the light emitting layer, but the use can be expanded if it is white light emission. As a method for whitening the light emission of the EL element, there is a method of mixing a plurality of EL phosphor particles that emit light in three primary colors or complementary colors. In these methods, there is a problem that the emission color changes with time due to the initial white color due to the difference in the deterioration rate of the EL phosphor particles of each color as the EL element is driven. In addition, a method of containing a fluorescent pigment that converts a part of light emitted from the EL phosphor particles into a complementary color wavelength in the light emitting layer described in Patent Documents 4 and 5, and a transparent electrode layer described in Patent Document 6 A method of providing a complementary color forming layer containing a fluorescent pigment between the light emitting layer and a light emitting layer in which a large amount of fluorescent pigment is distributed on the transparent electrode side described in Patent Document 7 are disclosed. In these cases, the light emitting layer is colored by the body color of the fluorescent pigment so that it does not appear white when no light is emitted, and the fluorescent pigment is deteriorated by ultraviolet rays or the like.

Next, as a method for solving these problems, a method using a white shielding layer described in Patent Document 8, a method of providing a fluorescent pigment layer described in Patent Document 9 on the side facing the transparent electrode of the light emitting layer, Patent Document 10, a method of using an ultraviolet absorbing film on the EL member described in No. 10, a method of providing a titanium oxide layer having a high ultraviolet absorbing ability, and the like. However, these methods require an expensive material and an extra layer for the EL element, and increase the production process of the EL element, which causes a problem that the manufacturing cost increases.
JP-A-7-62342 JP-A-6-330035 Japanese Patent Laid-Open No. 6-151059 Japanese Patent Publication No. 5-33514 Japanese Patent Publication No. 8-4037 JP-A-6-275380 Japanese Patent Laid-Open No. 2-197077 JP-A-9-245966 JP-A-11-67458 Japanese Patent Laid-Open No. 7-142173

  The present invention provides a dispersion type EL element that suppresses deterioration of a fluorescent pigment due to ultraviolet rays and non-light emission due to the fluorescent pigment without increasing the production process of the dispersion type EL element, and also causes deterioration of the fluorescent pigment due to ultraviolet rays. An object of the present invention is to provide a production method that can easily and easily produce a dispersion-type EL element in which coloring at the time of non-light emission by a fluorescent pigment is suppressed.

As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by adjusting the content of the fluorescent pigment in the layer to which the fluorescent pigment is added in the thickness direction of the layer. As a result of further studies, the present invention has been completed.
That is, the object of the present invention is realized by the following means.
(1) In a dispersive electroluminescence device having at least a transparent electrode, a light emitting layer in which electroluminescent phosphor particles are dispersed, a dielectric layer, and a back electrode in this order, the light emitting layer emits light from the electroluminescent phosphor particles. A fluorescent pigment that converts a part of the fluorescent pigment into another wavelength is dispersed, and the fluorescent pigment has a content distribution that is higher toward the back electrode side in the thickness direction of the light emitting layer. Electroluminescence element.
(2) 50% by mass or more of the content of the fluorescent pigment in the light emitting layer is contained in a portion having a film thickness within 30% from the end surface on the back electrode side with respect to the film thickness of the light emitting layer. The dispersive electroluminescence device according to (1).
(3) In a dispersive electroluminescent device having at least a transparent electrode, a light emitting layer in which electroluminescent phosphor particles are dispersed, a dielectric layer, and a back electrode in this order, the dielectric layer emits light from the electroluminescent phosphor particles. A dispersion type electroluminescent device, wherein a fluorescent pigment that converts a part of the fluorescent pigment to another wavelength is dispersed, and the content distribution of the fluorescent pigment is increased toward the light emitting layer side.
(4) 50% by mass or more of the content of the fluorescent pigment in the dielectric layer is contained within 30% of the film thickness from the end face on the light emitting layer side with respect to the film thickness of the dielectric layer. The dispersive electroluminescence device according to (3).
(5) The dispersion type electroluminescent device according to any one of (1) to (4), wherein the light emitting layer has a thickness in a range of 0.5 μm to 30 μm.
(6) The average particle size of the equivalent sphere diameter of the electroluminescent phosphor particles is in the range of 0.1 μm or more and 15 μm or less, according to any one of (1) to (5), Distributed electroluminescence element.
(7) The fluorescent pigment is a pigment having at least a color conversion material represented by the general formula (A) and a matrix resin that supports the color conversion material. The dispersion type electroluminescent element according to any one of the above.

In general formula (A), R ¹ , R ² , R ³ , R ⁴ , and R ⁵ each represent a hydrogen atom or a substituent. X represents an oxygen atom, a sulfur atom, or N—R ^Y1 , and R ^Y1 represents a hydrogen atom or a substituent. L represents a linking group comprising a conjugated bond. R ^x and R ^y each represent a hydrogen atom or a substituent, and at least one of them represents an electron withdrawing group.
(8) The dispersion type electroluminescent device according to (7), wherein the general formula (A) is represented by the general formula (I).

In the formula, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each represent a hydrogen atom or a substituent. X represents an oxygen atom, a sulfur atom, or N—R ^Y1 , and R ^Y1 represents a hydrogen atom or a substituent. L represents a linking group comprising a conjugated bond. Z ¹ represents an atomic group necessary for forming a 5- to 6-membered ring.

  (9) The dispersion type electroluminescent device according to (8), wherein the general formula (A) is represented by the general formula (II).

In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ³¹ , R ³² , R ³³ and R ³⁴ each represent a hydrogen atom or a substituent. X represents an oxygen atom, a sulfur atom, or N—R ^Y1 , and R ^Y1 represents a hydrogen atom or a substituent. Z ² represents an atomic group necessary for forming a 5- to 6-membered ring. L ₂₁ and L ₂₂ may be the same or different from each other, and each represents a methine group, a substituted methine group or a nitrogen atom. n represents an integer of 0 to 3.
(10) In the method for producing a dispersion-type electroluminescent element according to (1), the electroluminescent phosphor particles, a fluorescent pigment that converts a part of light emitted from the electroluminescent phosphor particles into another wavelength, a binder, and the binder A coating solution adjusting step for preparing a coating solution containing electroluminescent phosphor particles mixed and dispersed with a solvent for dissolving a binder, and applying the electroluminescent phosphor particle-containing coating solution on a transparent electrode to form a light emitting layer A method for producing a dispersion-type electroluminescent device, comprising: a light-emitting layer forming step; and a drying step of drying under conditions such that the content distribution of the fluorescent pigment on the back electrode side in the thickness direction of the light-emitting layer is high.
(11) In the method for producing a dispersion-type electroluminescent element according to (1), the electroluminescent phosphor particles, a fluorescent pigment that converts a part of light emitted from the electroluminescent phosphor particles to another wavelength, a binder, and the binder A coating solution adjusting step of mixing and dispersing a solvent for dissolving the binder while changing the addition amount of the fluorescent pigment to adjust two or more types of electroluminescent phosphor particle-containing coating solutions having different addition amounts of the fluorescent pigment, And two or more kinds of the above-mentioned electroluminescent phosphor particle-containing coating solutions are simultaneously laminated and coated so that the content of the fluorescent pigment is higher toward the back electrode side in the thickness direction of the light emitting layer. A dispersion type electroluminescent device comprising a light emitting layer forming step of forming a light emitting layer in which two or more layers are laminated Production method.

(12) In the method for producing a dispersion type electroluminescent device as described in (3) above, the fluorescent pigment, the binder, and the binding that convert part of the light emitted from the dielectric particles and the electroluminescent phosphor particle powder into different wavelengths Coating liquid adjustment step of adjusting a coating solution containing dielectric particles mixed and dispersed with a solvent for dissolving the agent, forming a dielectric layer by applying the coating solution containing dielectric particles on the back electrode A process for producing a dispersion type electroluminescent device, comprising: a step of drying under a condition that the content distribution of the fluorescent pigment on the light emitting layer side in the thickness direction of the dielectric layer is high.
(13) In the method for producing a dispersion-type electroluminescent element according to the above (3), a fluorescent pigment, a binder, and the binder that convert a part of light emitted from the dielectric particles and the electroluminescent phosphor particles to another wavelength A coating solution adjusting step for adjusting two or more kinds of dielectric particle-containing coating liquids having different fluorescent pigment addition amounts by mixing and dispersing the addition amount of the fluorescent pigment. Two or more layers having different fluorescent pigment contents are laminated such that the dielectric particle-containing coating solution is simultaneously laminated and applied so that the fluorescent pigment content increases toward the light emitting layer side in the thickness direction of the dielectric layer. A process for producing a dispersive electroluminescence device, comprising a dielectric layer forming step of forming a dielectric layer.
(14) The electroluminescent phosphor particle-containing coating solution or the dielectric particle-containing coating solution is applied using a slide coater or an extrusion coater, and any one of the above (10) to (13) The manufacturing method of the dispersive electroluminescent element of 1 item | term.
Here, the transparent electrode represents a transparent electrode that is formed on the main surface of the light emitting layer on the side from which light emitted from the light emitting layer is extracted, and the back electrode represents an electrode on the side that does not extract light emitted from the transparent electrode. .

In the dispersion type EL device of the present invention, the fluorescent pigment is distributed in the vicinity of the interface between the light emitting layer and the dielectric layer. In addition, since the EL phosphor particles serve as a fluorescent pigment shielding layer, coloring of the EL element when no light is emitted can be suppressed. In addition, since light emitted from the EL phosphor particles is efficiently converted to another wavelength, good light emission can be obtained even if the amount of the fluorescent pigment added is reduced.
Moreover, according to the method for manufacturing a dispersion-type EL element of the present invention, it is possible to manufacture an efficient dispersion-type EL element.

Hereinafter, the dispersion type EL element of the present invention will be described in detail.
The dispersion-type EL element of the present invention has a configuration having at least a transparent electrode, a light emitting layer in which EL phosphor particles are dispersed, a dielectric layer, and a back electrode in this order (see FIGS. 5, 7, 9, and 11).
As the transparent electrode and the back electrode, those conventionally used in this type of EL element can be used without particular limitation, and will be described in detail later.
Next, general matters of the light emitting layer and the dielectric layer will be described.
As the light emitting layer, a material in which EL phosphor particles described later are dispersed in a dispersant can be used. As the dispersant, a polymer having a relatively high dielectric constant such as a cyanoethyl cellulose resin, or a resin such as polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy resin, or vinylidene fluoride can be used. The dielectric constant can be adjusted by appropriately mixing fine particles having a high dielectric constant such as BaTiO ₃ and SrTiO _{3 with} these resins. As a dispersion method, a homogenizer, a planetary kneader, a roll kneader, an ultrasonic disperser, or the like can be used.
The thickness of the light emitting layer is preferably in the range of 0.5 μm to 30 μm.
As a dielectric material used for the dielectric layer, any material can be used as long as it has a high dielectric constant and insulation and a high dielectric breakdown voltage. Specifically, it is selected from metal oxides and nitrides. For example, TiO ₂ , BaTiO ₃ , SrTiO ₃ , PbTiO ₃ , KNbO ₃ , PbNbO ₃ , Ta ₂ O ₃ , BaTa ₂ O ₆ , LiTaO ₃ , Y ₂ O ₃ Al ₂ O ₃ , ZrO ₂ , AlON, ZnS, etc. are used. These may be installed as a uniform film, or may be installed as a film having a particle structure. In the case of a uniform film, the dielectric layer is prepared by a vapor phase method such as sputtering or vacuum deposition. In this case, the layer thickness is usually in the range of 0.1 μm to 10 μm.
The thickness of the dielectric layer is preferably 0.5 μm or more and 30 μm or less, and more preferably 20 μm or less.
The light emitting layer and the dielectric layer are preferably formed by applying a coating solution for forming each layer using a spin coating method, a dip coating method, a bar coating method, a spray coating method, or the like. In particular, it is preferable to use a method capable of continuous application, such as a slide coating method or an extrusion coating method.

  In addition, in the element configuration of the present invention, various protective layers, filter layers, light scattering reflection layers, and the like conventionally used in this type of EL element can be used as long as the desired effects of the present invention are not impaired. Can be granted.

In the dispersion-type EL element of the present invention, a fluorescent pigment that converts a part of light emitted from the EL phosphor particles into another wavelength is dispersed in the light-emitting layer or the dielectric layer. Is contained in the light emitting layer, the content distribution is higher toward the back electrode side in the thickness direction of the light emitting layer, and when contained in the dielectric layer, the content is The distribution is increased toward the light emitting layer side.
Hereinafter, the EL phosphor particles used in the light emitting layer in the present invention will be described first.
<EL phosphor particles>
Specifically, the matrix material of the EL phosphor particles preferably used in the present invention is one or more elements selected from the group consisting of Group II elements and Group VI elements, Group III elements and Group V elements. It is a semiconductor fine particle composed of one or more elements selected from the group consisting of group elements, and is 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, and ZnS, CdS, CaS, and the like can be preferably used. Further, the base material of the particles includes BaAl ₂ S ₄ , CaGa ₂ S ₄ , Ga ₂ O ₃ , Zn ₂ SiO ₄ , Zn ₂ GaO ₄ , ZnGa ₂ O ₄ , ZnGeO ₃ , ZnGeO ₄ , ZnAl ₂ O ₄ , _{CaGa 2 O 4, CaGeO 3,} Ca 2 Ge 2 O 7, CaO, Ga 2 O 3, GeO 2, SrAl 2 O 4, SrGa 2 O 4, srP 2 O 7, MgGa 2 O 4, Mg 2 GeO 4, MgGeO ₃ , BaAl ₂ O ₄ , Ga ₂ Ge ₂ O ₇ , BeGa ₂ O ₄ , Y ₂ SiO ₅ , Y ₂ GeO ₅ , Y ₂ Ge ₂ O ₇ , Y ₄ GeO ₈ , Y ₂ O ₃ , Y ₂ O ₂ S, SnO ₂ and mixed crystals thereof can be preferably used. Moreover, as an activator, metal ions, such as Mn and Cu, rare earth elements, etc. can be used preferably. Moreover, as a coactivator added as needed, halogen elements, such as Cl, Br, I, Al, etc. can be used preferably.

Furthermore, in the present invention, it is more preferable to use EL phosphor particles having the following characteristics.
(A) EL phosphor particles having an average particle size (equivalent sphere diameter) in the range of 0.1 to 15 μm and a particle size variation coefficient in the range of 3 to 30%.
(B) An EL phosphor particle synthesized by the urea melting method and having an average particle size in the range of 0.1 μm to 15 μm.
(C) An EL phosphor particle synthesized by a spray pyrolysis method and having an average particle size in the range of 0.1 μm to 15 μm.
(D) An EL phosphor particle comprising zinc sulfide having a multiple twin structure and an average particle size in the range of 5 nm to 15 μm, which is synthesized by a hydrothermal synthesis method.
(E) EL composed of zinc sulfide having an average particle size in the range of 0.1 μm or more and 15 μm or less and having a multiple twin structure inside the particles in an average plane spacing of 0.2 nm or more and 10 nm or less. Phosphor particles.
(F) The average particle size is in the range of 0.1 μm or more and 15 μm or less, and 30% or more of the particles are made of zinc sulfide having a ratio of the major axis to the minor axis of 1.5 or more. EL phosphor particles.
(G) The EL phosphor particles according to any one of (a) to (f), which are covered with a non-light emitting shell layer having a thickness of 0.01 μm or more.
(H) The EL phosphor particle according to any one of (a) to (g), wherein the activator is at least one ion selected from copper, manganese, silver, gold, and a rare earth element.
(I) The EL phosphor particles according to any one of (a) to (h), wherein the coactivator is at least one ion selected from chlorine, bromine, iodine, and aluminum.
(J) The EL phosphor particle according to any one of (a) to (i), wherein the activator is copper ion and the coactivator is chloride ion.

  The EL 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 sulfide, a fine particle powder (usually called raw powder) in the range of 10 nm or more and 50 nm or less is prepared by a liquid phase method, and this is used as a primary particle, and an impurity called an activator is mixed therein. Particles are obtained by performing first firing in a crucible together with the flux at a high temperature in the range of 900 ° C. to 1300 ° C. for 30 minutes to 10 hours. The intermediate EL phosphor particle powder obtained by the first baking is repeatedly washed with ion-exchanged water to remove alkali metal or alkaline earth metal, excess activator, and coactivator. Next, the obtained intermediate EL phosphor particle powder is subjected to second baking. In the second baking, heating (annealing) is performed in a range of 500 to 800 ° C., which is lower than that of the first baking, and in a range of 30 minutes to 3 hours for a short time. Although many stacking faults are generated in the EL phosphor particles due to these firings, the conditions of the first firing and the second firing are performed so that fine particles and more stacking faults are included in the EL phosphor particles. Is preferably selected as appropriate. Further, by applying an impact force in a certain range to the first fired product, the density of stacking faults can be greatly increased without destroying the particles. As a method of applying impact force, a method of contacting and mixing intermediate EL phosphor particles, a method of mixing and mixing spheres such as alumina (ball mill), a method of accelerating and colliding particles, a method of irradiating ultrasonic waves, etc. It can be preferably used. Thereafter, etching is performed with an acid such as HCl to remove the metal oxide adhering to the surface, and copper sulfide adhering to the surface is removed by washing with KCN and dried to obtain EL phosphor particles.

  In addition, in the case of zinc sulfide or the like, a hydrothermal synthesis method is preferably used as the particle formation method of the EL phosphor particles because a multiple twin structure is introduced into the EL phosphor particle crystal. In the hydrothermal synthesis system, particles are dispersed in a well-stirred aqueous solvent, and zinc ions and / or sulfur ions that cause particle growth are determined from the outside of the reaction vessel at a flow rate controlled with an aqueous solution. Add for a long time. Therefore, in this system, the particles can move freely in an aqueous solvent, and the added ions can diffuse in water and cause particle growth uniformly. The concentration distribution of the agent can be changed, and particles that cannot be obtained by the firing method can be obtained. In the control of the particle size distribution, the nucleation process and the growth process can be clearly separated, and the particle size distribution can be controlled by freely controlling the degree of supersaturation during particle growth. Monodispersed zinc sulfide particles having a narrow distribution can be obtained. It is preferable to insert an Ostwald ripening step between the nucleation process and the growth process in order to adjust the grain size and realize a multiple twin structure.

  Zinc sulfide has a very low solubility in water, which is a very disadvantageous property in growing particles by ionic reaction in aqueous solution. The solubility of zinc sulfide in water increases as the temperature increases, but at 375 ° C. or higher, the water becomes supercritical and the solubility of ions decreases drastically. Therefore, the particle preparation temperature is preferably in the range of 100 ° C. to 375 ° C., more preferably in the range of 200 ° C. to 375 ° C. The time required for particle preparation is preferably within 100 hours, more preferably within 12 hours and 5 minutes or more.

  As another method for increasing the solubility of zinc sulfide in water, a chelating agent is preferably used in the present invention. As the chelating agent for zinc ions, those having an amino group or a carboxyl group are preferable. Specifically, ethylenediaminetetraacetic acid (hereinafter referred to as EDTA), N, 2-hydroxyethylethylenediaminetriacetic acid (hereinafter referred to as EDTA-OH). Diethylenetriaminepentaacetic acid, 2-aminoethylethyleneglycoltetraacetic acid, 1,3-diamino-2-hydroxypropanetetraacetic acid, nitrilotriacetic acid, 2-hydroxyethyliminodiacetic acid, iminodiacetic acid, 2-hydroxyethylglycine Ammonia, methylamine, ethylamine, propylamine, diethylamine, diethylenetriamine, triaminotriethylamine, allylamine, ethanolamine, and the like.

  In addition, when synthesizing the constituent metal ions and chalcogen anions by direct precipitation reaction without using the precursors of the constituent elements, rapid mixing of both solutions is necessary, and a double jet mixer is used. preferable.

  It is also preferable to use a urea melting method as a method for forming EL phosphor particles that can be used in the present invention. The urea melting method is a method using molten urea as a medium for synthesizing EL phosphor particles. A substance containing an element forming an EL phosphor particle matrix or an activator is dissolved in a liquid in which urea is maintained at a temperature equal to or higher than the melting point to be in a molten state. Add reactants as needed. For example, when synthesizing sulfide EL phosphor particles, a sulfur source such as ammonium sulfate, thiourea or thioacetamide is added to cause precipitation reaction. When the temperature of the melt is gradually raised to about 450 ° C., a solid in which EL phosphor particles and EL phosphor particle intermediates are uniformly dispersed in a urea-derived resin is obtained. After this solid is finely pulverized, it is fired while thermally decomposing the resin in an electric furnace. By selecting an inert atmosphere, an oxidizing atmosphere, a reducing atmosphere, an ammonia atmosphere, or a vacuum atmosphere as the firing atmosphere, EL phosphor particles based on oxide, sulfide, or nitride can be synthesized.

  Moreover, it is also preferable to use the spray pyrolysis method as a method of forming EL phosphor particles that can be used in the present invention. The precursor solution of the EL phosphor particles is made into fine droplets using an atomizer, and the EL phosphor particles or EL are obtained by condensation in the droplets, chemical reaction, or chemical reaction with the ambient gas around the droplets. A phosphor particle intermediate product can be synthesized. By making the conditions for droplet formation suitable, particles having a fine particle size, a uniform amount of impurities, a spherical shape, and a narrow particle size distribution can be obtained. As an atomizer that generates fine droplets, it is preferable to use a two-fluid nozzle, an ultrasonic atomizer, or an electrostatic atomizer. The fine droplets generated by the atomizer are introduced into an electric furnace with a carrier gas and heated to dehydrate and condense, and the chemical reaction and sintering of the substances in the droplets, or the chemistry with the atmosphere gas The target EL phosphor particles or EL phosphor particle intermediate products are obtained by the reaction. The obtained particles are additionally fired as necessary. For example, when synthesizing zinc sulfide EL phosphor particles, a mixed solution of zinc nitrate and thiourea is atomized and thermally decomposed at about 800 ° C. in an inert gas (for example, nitrogen) to form a spherical zinc sulfide EL. Obtain phosphor particles. If trace impurities such as Mn, Cu and rare earth are dissolved in the starting mixed solution, it acts as a luminescent center. Further, starting from a mixed solution of yttrium nitrate and europium nitrate at about 1000 ° C. in an oxygen atmosphere, yttrium oxide EL phosphor particles activated with europium are obtained. It is not necessary that all components in the droplet are dissolved, and ultrafine particles of silicon dioxide may be contained. Zinc silicate EL phosphor particles can be obtained by thermal decomposition of fine droplets containing zinc solution and silicon dioxide ultrafine particles.

  The EL phosphor particles that can be used in the present invention include laser ablation, CVD, plasma CVD, sputtering, resistance heating, electron beam, and fluid oil surface deposition. Phase methods, metathesis methods, precursor thermal decomposition methods, reverse micelle methods, methods combining these methods with high-temperature firing, and liquid phase methods such as freeze-drying methods can also be used.

  In these methods, EL phosphor particles having an average particle size of 0.1 μm or more and 15 μm or less that are preferably used in the present invention can be obtained by controlling the particle preparation conditions.

  More preferably, the EL phosphor particles have a non-light emitting shell layer on the surface of the particles. This shell layer is preferably formed with a thickness of 0.01 μm or more using a chemical method following the preparation of the fine particles serving as the core of the EL phosphor particles. Preferably it is the range of 0.01 micrometer or more and 1.0 micrometer or less. The non-light emitting shell layer can be formed from an oxide, a nitride, an oxynitride, or a material having the same composition formed on the host EL phosphor particles and containing no emission center. It can also be formed by epitaxially growing substances having different compositions on the matrix EL phosphor particle material. As a method of forming the non-light emitting shell layer, a laser ablation method, a CVD method, a plasma CVD method, a sputtering method, a resistance heating method, an electron beam method, and a gas phase method such as a method combining fluid oil surface deposition, a metathesis method, Sol-gel method, ultrasonic chemistry method, precursor thermal decomposition method, reverse micelle method or a combination of these methods with high-temperature firing, hydrothermal synthesis method, urea melting method, freeze drying method, etc. A thermal decomposition method or the like can also be used.

  In particular, the hydrothermal synthesis method, the urea melting method, and the spray pyrolysis method, which are preferably used for the formation of EL phosphor particles, are also suitable for the synthesis of a non-luminescent shell layer. For example, when a non-light-emitting shell layer is attached to the surface of zinc sulfide EL phosphor particles by using a hydrothermal synthesis method, zinc sulfide EL phosphor particles serving as core particles are added and suspended in a solvent. As in the case of particle formation, a solution containing a metal ion to be a non-light emitting shell layer material and an anion as necessary is added from the outside of the reaction vessel at a controlled flow rate for a predetermined time. By sufficiently agitating the inside of the reaction vessel, the particles can move freely in the solvent, and the added ions can diffuse in the solvent and cause particle growth uniformly. The non-light emitting shell layer can be uniformly formed. By firing the particles as necessary, zinc sulfide EL phosphor particles having a non-light emitting shell layer on the surface can be synthesized.

  In addition, when a non-light emitting shell layer is attached to the surface of the zinc sulfide EL phosphor particles using the urea melting method, the metal salt as the non-light emitting shell layer material is dissolved, and the zinc sulfide EL is dissolved in the molten urea solution. Add phosphor particles. Since zinc sulfide does not dissolve in urea, the temperature of the solution is raised as in the case of particle formation to obtain a solid in which zinc sulfide EL phosphor particles and non-light emitting shell layer material are uniformly dispersed in urea-derived resin. After this solid is finely pulverized, it is fired while thermally decomposing the resin in an electric furnace. Zinc sulfide EL phosphor having non-light emitting shell layer made of oxide, sulfide, nitride on the surface by selecting inert atmosphere, oxidizing atmosphere, reducing atmosphere, ammonia atmosphere, vacuum atmosphere as firing atmosphere Particles can be synthesized.

  In addition, when a non-light emitting shell layer is attached to the surface of the zinc sulfide EL phosphor particles using the spray pyrolysis method, the zinc sulfide EL phosphor particles are dissolved in a solution in which the metal salt serving as the non-light emitting shell layer material is dissolved. Add. By atomizing and thermally decomposing this solution, a non-light emitting shell layer is generated on the surface of the zinc sulfide EL phosphor particles. By selecting a pyrolysis atmosphere or an additional firing atmosphere, zinc sulfide EL phosphor particles having a non-light emitting shell layer made of oxide, sulfide, or nitride on the surface can be synthesized.

<Fluorescent pigment>
Next, the fluorescent pigment used in the present invention will be described.
The fluorescent pigment used in the present invention is preferably one that converts part of the light emitted from the EL phosphor particles into light having a complementary color relationship. For example, a combination of ZnS: Cu, ClEL phosphor particles that emit blue-green light and rhodamine-based fluorescent pigments, pyridine-based pigments, oxazine-based pigments, and the like that convert red light emission can be suitably used. At this time, the CIE chromaticity coordinates (x, y) are preferably combined so that the x value is in the range of 0.30 to 0.43 and the y value is in the range of 0.27 to 0.41.

  Furthermore, as the fluorescent pigment used in the present invention, it is more preferable to use a fluorescent pigment containing a color conversion material represented by the general formula (A). Furthermore, the fluorescent pigment comprises at least a color conversion material represented by the general formula (A) and a matrix resin that supports the color conversion material, and absorbs light emitted from other than the color conversion material. A pigment that emits light is preferred.

The compound represented by the general formula (A) will be described below.
In general formula (A), R ¹ , R ² , R ³ , R ⁴ , and R ⁵ may be the same or different from each other, and each represents a hydrogen atom or a substituent.

Examples of the substituent represented by R ¹ and R ² include an alkyl group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, and particularly preferably 6 to 12 carbon atoms, such as n-hexyl). , N-octyl, n-decyl, n-hexadecyl, tert-amyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 6 to 20 carbon atoms, more preferably having 6 to 16 carbon atoms, Particularly preferably, it has 6 to 12 carbon atoms, such as 4-hexanyl), an alkynyl group (preferably 6 to 20, more preferably 6 to 16 carbon atoms, particularly preferably 2 to 8 carbon atoms). For example, propargyl, 4-hexanyl, etc.), an aryl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 20 carbon atoms, Preferably have 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl, anthryl, phenanthryl, pyrenyl, etc.), acyl groups (preferably 6 to 20 carbon atoms, more preferably 6 carbon atoms). To 16, particularly preferably 6 to 12 carbon atoms, such as hexanoyl, 2,2-dimethylbutyroyl, benzoyl, etc.), alkoxycarbonyl groups (preferably 6 to 20 carbon atoms, more preferably carbon atoms). 6 to 16, particularly preferably 6 to 12 carbon atoms, such as pentyloxycarbonyl, octyloxycarbonyl, etc.), an aryloxycarbonyl group (preferably 7 to 20 carbon atoms, more preferably 7 to 7 carbon atoms). 16, particularly preferably 7 to 10 carbon atoms, such as phenyloxycarbonyl. ), A sulfamoyl group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as hexyl sulfamoyl, dipropyl sulfamoyl, phenyl sulfa ), A carbamoyl group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as pentylcarbamoyl, dipropylcarbamoyl, phenylcarbamoyl, etc. ), A sulfonyl group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as hexylsulfonyl, tosyl, etc.), sulfinyl. Group (preferably having 6 to 20 carbon atoms, more preferably having 6 to 16 carbon atoms, particularly preferably A prime number 6-12, such as methane sulfinyl, benzenesulfinyl, and the like. ), An imino group, a heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom. Examples thereof include imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino, benzoxazolyl, benzoimidazolyl, benzothiazolyl, carbazolyl, azepinyl and the like. These substituents may be further substituted. When there are two or more substituents, they may be the same or different. If possible, they may be linked to each other to form a ring.

R ¹ and R ² are preferably a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, a heterocyclic group, a group in which L and an alkylene group are linked to form a 5- or 6-membered ring, and R ¹ and R ² are linked. A 5- to 7-membered ring, more preferably a hydrogen atom, an alkyl group, an aryl group, a L-alkylene group connected to form a 5- or 6-membered ring, and R ¹ and R ² connected A 5- to 7-membered ring, particularly preferably an alkyl group having 6 to 12 carbon atoms, a L-alkylene group connected to form a 5- or 6-membered ring, and R ¹ and R ² are They are linked to form a 5- to 7-membered ring.

Examples of the substituent represented by R ^{3 to} R ⁵ include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms, such as methyl and ethyl). , Iso-propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2-20 carbon atoms, more preferably carbon number). 2 to 12, particularly preferably 2 to 8 carbon atoms, such as vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl groups (preferably 2 to 20 carbon atoms, more preferably carbon numbers) 2 to 12, particularly preferably 2 to 8 carbon atoms, such as propargyl and 3-pentynyl), aryl groups (preferably Prime number 6-30, More preferably, it is C6-C20, Most preferably, it is C6-C12, for example, phenyl, p-methylphenyl, naphthyl, anthryl, phenanthryl, pyrenyl etc. are mentioned), an amino group ( Preferably it is C0-20, More preferably, it is C0-12, Most preferably, it is C0-6, for example, amino, methylamino, dimethylamino, diethylamino, diphenylamino, dibenzylamino etc. are mentioned. ), An alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy and the like), an aryloxy group ( Preferably it has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, For example, phenyloxy, 2-naphthyloxy, etc.), a heterocyclic oxy group (preferably having 2 to 20 carbon atoms, more preferably 3 to 16 carbon atoms, particularly preferably 4 to 12 carbon atoms, such as pyridinooxy , Pyrimidinooxy, pyridazinooxy, benzimidazolyloxy, etc.), silyloxy groups (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 20 carbon atoms, such as trimethylsilyloxy, t-butyldimethyloxy, etc.), acyl groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms such as acetyl, benzoyl, formyl, Pivaloyl, etc.), an alkoxycarbonyl group (preferably having 2 to 2 carbon atoms). 0, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl and the like. ), An aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, such as phenyloxycarbonyl), an acyloxy group (preferably). Has 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetoxy, benzoyloxy and the like, and an acylamino group (preferably having 2 to 20 carbon atoms, More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino, benzoylamino and the like, and an alkoxycarbonylamino group (preferably 2 to 20 carbon atoms, more preferably carbon atoms). 2 to 16, particularly preferably 2 to 12, and examples thereof include methoxycarbonylamino and the like. An aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino). A sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfonylamino, benzenesulfonylamino, etc.), a sulfamoyl group ( Preferably it is C0-20, More preferably, it is C0-16, Most preferably, it is C0-12, for example, sulfamoyl, methyl sulfamoyl, dimethyl sulfamoyl, phenyl sulfamoyl etc. are mentioned. ), A carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 1 carbon atoms). Particularly preferably having 1 to 12 carbon atoms, such as carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, Particularly preferably, it has 1 to 12 carbon atoms, and examples thereof include methylthio, ethylthio, etc.), an arylthio group (preferably 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms). For example, phenylthio and the like), a heterocyclic thio group (preferably having 4 to 20 carbon atoms, more preferably 4 to 16 carbon atoms, particularly preferably 4 to 12 carbon atoms, such as pyridinothio, pyrimidinothio, And pyridazinothio, benzimidazolylthio, thiadiazolylthio, etc.). A sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include mesyl and tosyl. ), A sulfinyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), a ureido group (preferably Has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably carbon 1-20, more preferably 1-16 carbon atoms, particularly preferably 1-12 carbon atoms, such as diethyl phosphoric acid amide and phenylphosphoric acid amide)), hydroxy group, mercapto group, halogen atom (For example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, Droxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom. Specific examples include imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino, benzoxazolyl, benzoimidazolyl, benzothiazolyl, carbazolyl, azepinyl, and the like, and a silyl group (preferably having a carbon number). 3 to 40, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include trimethylsilyl and triphenylsilyl). These substituents may be further substituted. When there are two or more substituents, they may be the same or different. If possible, they may be linked to each other to form a ring.

R ³ is preferably a hydrogen atom, an alkyl group, an aryl group, a halogen atom, or a cyano group, more preferably a hydrogen atom or an alkyl group, and still more preferably a hydrogen atom. R ⁴ is preferably a hydrogen atom, an alkyl group, an aryl group, an aromatic heterocyclic group, or a ring formed by linking with R ⁵ , more preferably a hydrogen atom or an alkyl group, still more preferably a hydrogen atom. It is.
R ⁵ is preferably a hydrogen atom, an alkyl group, an aryl group, an aromatic heterocyclic group, or a ring formed by linking with R ⁴ , more preferably an alkyl group (preferably an alkyl having 2 to 20 carbon atoms). Group, more preferably a branched or cyclic alkyl group having 3 to 20 carbon atoms, still more preferably a branched or cyclic alkyl group having a quaternary carbon having 4 to 12 carbon atoms, particularly preferably a tert-butyl group.) An aryl group (preferably an aryl group having a substituent in the o-position, more preferably an alkyl-substituted phenyl group having a substituent in the o-position having 7 to 30 carbon atoms, still more preferably a 2,6-dimethyl-substituted phenyl Group, particularly preferably 2,4,6-trimethylphenyl group.), Particularly preferably tert-butyl group, 2,4,6-trimethylphenyl group. And most preferably a tert-butyl group.

X represents an oxygen atom, a sulfur atom, or N—R ^Y1 , and R ^Y1 represents a hydrogen atom or a substituent. Examples of the substituent represented by R ^Y1 include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms. For example, methyl, ethyl, iso- Propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms). Particularly preferably, it has 2 to 8 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, 3-pentenyl and the like, and an alkynyl group (preferably 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms). Particularly preferably, it has 2 to 8 carbon atoms, and examples thereof include propargyl and 3-pentynyl), an aryl group (preferably A prime number of 6-30, more preferably a carbon number of 6-20, particularly preferably a carbon number of 6-12, for example, phenyl, p-methylphenyl, naphthyl, etc.), an acyl group (preferably a carbon number of 1 20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as acetyl, benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, and more). Preferably it has 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, and examples thereof include methoxycarbonyl, ethoxycarbonyl and the like, and an aryloxycarbonyl group (preferably 7 to 20 carbon atoms, more preferably carbon atoms). 7 to 16, particularly preferably 7 to 10 carbon atoms, such as phenyloxycarbonyl ), A sulfamoyl group (preferably having a carbon number of 0 to 20, more preferably a carbon number of 0 to 16, particularly preferably a carbon number of 0 to 12, such as sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfa A carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl). ), A sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl and tosyl), sulfinyl. Group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, Preferably, it has 1 to 12 carbon atoms, and examples thereof include methanesulfinyl and benzenesulfinyl. ), A heterocyclic group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom and a sulfur atom, specifically, for example, imidazolyl, pyridyl and furyl. , Piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.). These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked to form a ring.

The substituent represented by R ^Y1 is preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, more preferably an alkyl group, an aryl group or an aromatic heterocyclic group, still more preferably Is an alkyl group or an aryl group.

X is preferably an oxygen atom or N—R ^Y1 , more preferably an oxygen atom.

  L represents a linking group of a conjugated bond. The linking group represented by L is preferably a conjugated bond linking group formed of C, N, O, S, Se, Te, Si, Ge or the like, more preferably alkenylene, alkynylene, arylene, divalent. Of the aromatic heterocycle (preferably an aromatic heterocycle formed from azine, azole, thiophene, furan ring) and a combination of N and a combination thereof, more preferably alkenylene, arylene, divalent And a group consisting of a combination of N and these, and particularly preferably a group consisting of a combination of alkenylene and arylene having 6 to 30 carbon atoms or a divalent aromatic heterocyclic ring having 2 to 30 carbon atoms. And most preferred is a group comprising a combination of alkenylene and arylene having 6 to 30 carbon atoms. Specific examples of the linking group represented by L include the following.

The linking group represented by L may have a substituent, and examples of the substituent include those exemplified as the substituents represented by R ^{1 to} R ⁵ . The substituent for L is preferably an alkyl group, alkenyl group, alkynyl group, aryl group, alkoxy group, aryloxy group, acyl group, halogen atom, cyano group, heterocyclic group, silyl group, more preferably an alkyl group. , Alkenyl group, alkynyl group, aryl group, alkoxy group, aryloxy group, halogen atom, cyano group, aromatic heterocyclic group, more preferably alkyl group, aryl group, alkoxy group, aryloxy group, aromatic Heterocyclic group.

R ^x and R ^y may be the same or different from each other, and each represents a hydrogen atom or a substituent, and at least one represents an electron-withdrawing group. R ^x and R ^y may be linked to form a ring.

As the substituents represented by R ^x and R ^y , those exemplified as the substituents of R ^{1 to} R ⁵ can be applied. The substituents represented by R ^x and R ^y are preferably alkyl groups, alkenyl groups, aryl groups, alkoxy groups, aryloxy groups, carbonyl groups, thiocarbonyl groups, oxycarbonyl groups, acylamino groups, carbamoyl groups, sulfonylamino groups. Group, sulfamoyl group, sulfonyl group, sulfinyl group, phosphoryl group, imino group, cyano group, halogen atom, silyl group, aromatic heterocyclic group, more preferably Hammett's σp value (sigma para value) is 0.2 or more And more preferably an aryl group, aromatic heterocyclic group, cyano group, carbonyl group, thiocarbonyl group, oxycarbonyl group, carbamoyl group, sulfamoyl group, sulfonyl group, imino group, halogen atom and R der that ^x and R ^y linked to form a ring electron withdrawing group , Particularly preferably obtained by forming an aromatic heterocyclic group, a carbonyl group, a cyano group, an imino group, and of R ^x and R ^y are joining the ring electron withdrawing groups, and most preferably a cyano group, and R ^{x Ry} is linked to form an electron-withdrawing group ring, and ^Rx and ^Ry are linked to form an electron-withdrawing group ring.

As the compound represented by the general formula (A), a compound represented by the general formula (I) in which R ^x and R ^{y in} the general formula (A) are connected to form a ring is more preferably used.

The general formula (I) will be described below. Z ¹ represents an atomic group necessary for forming a 5-membered ring or a 6-membered ring, and the ring formed is preferably a merocyanine dye which is usually used as an acidic nucleus. Specific examples thereof include the following: Can be mentioned.

(A) 1,3-dicarbonyl nucleus: For example, 1,3-indandione nucleus, 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, 1,3-dioxane-4, 6- Zeon etc.
(B) pyrazolinone nucleus: for example 1-phenyl-2-pyrazolin-5-one, 3-methyl-1-phenyl-2-pyrazolin-5-one, 1- (2-benzothiazoyl) -3-methyl-2 -Pyrazolin-5-one and the like.
(C) Isoxazolinone nucleus: For example, 3-phenyl-2-isoxazolin-5-one, 3-methyl-2-isoxazolin-5-one and the like.
(D) Oxindole nucleus: For example, 1-alkyl-2,3-dihydro-2-oxindole and the like.
(E) 2,4,6-triketohexahydropyrimidine nucleus: for example, barbituric acid or 2-thiobarbituric acid and its derivatives. Examples of derivatives include 1-alkyl compounds such as 1-methyl and 1-ethyl, 1,3-dialkyl compounds such as 1,3-dimethyl, 1,3-diethyl and 1,3-dibutyl, 1,3-diphenyl, 1,3-diaryl compounds such as 1,3-di (p-chlorophenyl), 1,3-di (p-ethoxycarbonylphenyl), 1-alkyl-1-aryl compounds such as 1-ethyl-3-phenyl, 1,3-di (2￣pyridyl) 1,3-diheterocyclic substituents and the like.

(F) 2-thio-2,4-thiazolidinedione nucleus: for example, rhodanine and its derivatives. Examples of the derivatives include 3-alkylrhodanine such as 3-methylrhodanine, 3-ethylrhodanine and 3-allylrhodanine, 3-arylrhodanine such as 3-phenylrhodanine, and 3- (2-pyridyl) rhodanine. And the like.
(G) 2-thio-2,4-oxazolidinedione (2-thio-2,4- (3H, 5H) -oxazoledione nucleus: for example, 3-ethyl-2-thio-2,4-oxazolidinedione and the like.
(H) Tianaphthenone nucleus: For example, 3 (2H) -thianaphthenone-1, 1-dioxide and the like.
(I) 2-thio-2,5-thiozolidinedione nucleus: For example, 3-ethyl-2-thio-2,5-thiazolidinedione and the like.
(J) 2,4-thiozolidinedione nucleus: for example 2,4-thiazolidinedione, 3-ethyl-2,4-thiazolidinedione, 3-phenyl-2,4-thiazolidinedione, etc. (k) thiazoline-4- On nucleus: For example, 4-thiazolinone, 2-ethyl-4-thiazolinone and the like.
(L) 4-thiazolidinone nucleus: for example, 2-ethylmercapto-5-thiazoline-4-one, 2-alkylphenylamino-5-thiazoline-4-one, and the like.
(M) 2,4-imidazolidinedione (hydantoin) nucleus: for example, 2,4-imidazolidinedione, 3-ethyl-2,4-imidazolidinedione and the like.
(N) 2-thio-2,4-imidazolidinedione (2-thiohydantoin) nucleus: for example 2-thio-2,4-imidazolidinedione, 3-ethyl-2-thio-2, 4-imidazolidinedione Such.
(O) Imidazolin-5-one nucleus: For example, 2-propylmercapto-2-imidazolin-5-one and the like.
(P) 3,5-pyrazolidinedione nucleus: for example, 1,2-diphenyl-3,5-pyrazolidinedione, 1,2-dimethyl-3,5-pyrazolidinedione and the like.
(Q) Benzothiophen-3-one nucleus: for example, benzothiophen-3-one, oxobenzothiophen-3-one, dioxobenzothiophen-3-one and the like.
(R) Indanone nucleus: For example, 1-indanone, 3-phenyl-1-indanone, 3-methyl-1-indanone, 3,3-diphenyl-1-indanone, 3,3-dimethyl-1-indanone and the like.

The ring formed by Z ¹ is preferably 1,3-dicarbonyl nucleus, pyrazolinone nucleus, 2,4,6-triketohexahydropyrimidine nucleus (including thioketone body), 2-thio-2,4-thiazolidinedione Nucleus, 2-thio-2, 4-oxazolidinedione nucleus, 2-thio-2, 5-thiazolidinedione nucleus, 2,4-thiazolidinedione nucleus, 2,4-imidazolidinedione nucleus, 2-thio-2, 4 -Imidazolidinedione nucleus, 2-imidazolin-5-one nucleus, 3,5-pyrazolidinedione nucleus, benzothiophen-3-one nucleus, indanone nucleus, more preferably 1,3-dicarbonyl nucleus, 4,6-triketohexahydropyrimidine nucleus (including thioketone body), 3,5-pyrazolidinedione nucleus, benzothiophen-3-one nucleus, indanone nucleus, Preferably a 1,3-dicarbonyl nucleus or a 2,4,6-triketohexahydropyrimidine nucleus (including a thioketone form), most preferably 1,3-indanedione nucleus.

  Of the compounds represented by the general formula (I), the compound represented by the general formula (II) is more preferable.

In the formula (II), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and X have the same meanings as those in the general formula (I), and preferred ranges are also the same. R ³¹ , R ³² , R ³³ and R ³⁴ each represent a hydrogen atom or a substituent. As the substituents represented by R ³¹ to R ³⁴ , for example, those exemplified as the substituents for R ^{1 to} R ⁵ can be applied. Further, R ³² and R ¹ , R ³⁴ and R ² may be connected to each other to form a ring (5- to 6-membered ring). Z ² represents an atomic group necessary for forming a 5- to 6-membered ring.

The ring formed by Z ² has a 1,3-dicarbonyl structure in the ring formed by Z ^1. For example, 1,3-cyclopentanedione, 1,3-cyclohexane And dione, 1,3-indandione, 3,5-pyrazolidinedione, 2,4,6-triketohexahydropyrimidine nucleus, etc., preferably 1,3-indandione, 3,5-pyrazo Lysine dione, barbituric acid or 2-thiobarbituric acid and derivatives thereof, more preferably 1,3-indandione, 1,2-diaryl-3,5-pyrazolidinedione, still more preferably 1,3- Indandione and 1,2-diphenyl-3,5-pyrazolidinedione are preferable, and 1,3-indandione is particularly preferable. The ring formed by Z ² may have a substituent, and examples of the substituent include those exemplified as the substituents of R ^{1 to} R ⁵ . In addition, substituents may be connected to form a ring.

L ₂₁ and L ₂₂ may be the same or different from each other, each a methine group, a substituted methine group or a nitrogen atom, also via the substituent of the substituted methine group at L ₂₁ or L ₂₂ each other or L ₂₁ and L ₂₂ may be linked to form a 4- to 6-membered ring. Further, when possible, L ₂₁ and L ₂₂ may be linked to R ³ , R ³¹ or R ³³ to form a ring. As the substituent of the substituted methine group, those exemplified as the substituents represented by R ^{1 to} R ⁵ can be applied, and preferably an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group. A group, a cyano group and a halogen atom, more preferably an alkyl group and an alkoxy group, still more preferably a lower alkyl group (preferably having 1 to 4 carbon atoms). L ₂₁ and L ₂₂ are preferably unsubstituted methine groups, alkyl-substituted methine groups, alkoxy-substituted methine groups, or L ₂₂ linked to R ³¹ or R ³³ to form a 5- or 6-membered ring, more preferably Is an unsubstituted methine group, or L ₂₂ linked to R ³¹ or R ³³ to form a 5- or 6-membered ring, more preferably an unsubstituted methine group. n represents an integer of 0 to 3, preferably 0, 1 or 2, more preferably 0 or 1, and still more preferably 1.

  The color conversion material represented by the general formula (A), the general formula (I) and the general formula (II) may be a low molecular weight compound or a high molecular weight compound in which a residue is connected to a polymer main chain (preferably Having a mass average molecular weight of 1,000 to 5,000,000, more preferably 5,000 to 2,000,000, still more preferably 10,000 to 1,000,000), or a compound represented by general formula (A), general formula (I) and general formula (II) in the main chain It may be a high molecular weight compound (preferably a mass average molecular weight of 1,000 to 5,000,000, more preferably 5,000 to 2,000,000, still more preferably 10,000 to 1,000,000). In the case of a high molecular weight compound, it may be a homopolymer, may be a copolymer with another polymer, and if it is a copolymer, it may be a random copolymer or a block copolymer. There may be. The color conversion material of the present invention is preferably a low molecular weight compound. The color conversion material of the present invention may be contained in a state in which a metal chelate is formed.

  Specific examples of the color conversion material include the following, but the present invention is not limited thereto. In addition, the following compound may form the tautomer and metal complex.

In addition, such a color conversion material is made of polymethacrylate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, alkyd resin, aromatic sulfonamide resin, urea resin, melamine resin, benzoguanamine resin, and a mixture of these resins. It is preferable to use it as a fluorescent pigment by kneading into a matrix resin such as These fluorescent pigments may be used alone or in combination of two or more in order to adjust the fluorescent hue.
The blending ratio of the fluorescent pigment is preferably 0.001 to 10 parts by mass with respect to 100 parts by mass of the EL phosphor particles to be used in both cases of inclusion in the light emitting layer and inclusion in the dielectric layer. More preferably, it is 0.01-5 mass parts.

In the present invention, when the fluorescent pigment is added to the light-emitting layer, the light-emitting layer contains the EL phosphor particles, the fluorescent pigment, a binder, and a solvent that dissolves the binder. It is preferably formed by applying a particle-containing coating solution. When the fluorescent pigment is added to the dielectric layer, the dielectric layer includes a dielectric particle-containing coating containing the dielectric particles, the fluorescent pigment, a binder, and a solvent that dissolves the binder. It is preferably formed by applying a liquid.
When the light emitting layer contains a fluorescent pigment, the dielectric layer may or may not contain a fluorescent pigment. When the dielectric layer contains a fluorescent pigment, the light emitting layer contains a fluorescent pigment. It does not have to be allowed. When the fluorescent pigment is not contained, a coating liquid obtained by removing the fluorescent pigment from the EL phosphor particle-containing coating liquid and the dielectric particle-containing coating liquid can be used.
Examples of the binder that can be used in this case include cyano resins, fluorine resins, and urethane resins.
Examples of the solvent that can be used in this case include alcohol solvents, ketone solvents, amide solvents, ether solvents, phenol solvents, and chlorine solvents.
In addition, the amount of the binder used is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the EL phosphor particles or dielectric particles from the viewpoint of phosphor density and adhesion of the light emitting layer. More preferably, it is 60 mass parts.

Moreover, in this invention, it is necessary to provide the distribution of the fluorescent pigment contained in a light emitting layer or a dielectric layer. That is, as shown in FIGS. 5, 7, 9, and 11 described later, the fluorescent pigment is unevenly distributed in the vicinity of the interface between the light emitting layer and the dielectric layer. Distribution can be imparted to the fluorescent pigment in the light emitting layer or dielectric layer by applying multi-layer coating of EL phosphor particle-containing coating solution with different fluorescent pigment addition amount or dielectric fine particle-containing coating solution with different fluorescent pigment addition amount .
Further, in the light emitting layer or the dielectric layer, the distribution can also be imparted by utilizing the difference in sedimentation speed between the fluorescent pigment and the EL phosphor particles or the dielectric particles. The sedimentation rate of the particles is determined by the specific gravity and the particle size. Usually, the specific gravity of the fluorescent pigment is smaller than that of the EL phosphor particles and the dielectric particles. Therefore, if the particle size is the same, the sedimentation rate of the fluorescent pigment is the EL phosphor particles and the dielectric particles. Slower than body particles. It is preferable to make the particle size of the fluorescent pigment smaller than that of the EL phosphor particles and the dielectric particles, thereby further slowing the sedimentation rate and facilitating the distribution of the fluorescent pigment. In such a case, it is preferable to select a fluorescent pigment that does not dissolve in a solvent in which EL phosphor particles or dielectric particles are dispersed. A fluorescent pigment or fluorescent dye made of an inorganic substance is dispersed in an insoluble polymer. Those are more preferred. Since the particle size of the fluorescent pigment is preferably smaller, it is preferable to make it smaller than the EL phosphor particles using a jet mill pulverizer or the like as necessary.

In the EL device of the present invention, when a fluorescent pigment is added to the light emitting layer, the fluorescent pigment is added to the light emitting layer in order to suppress the deterioration of the fluorescent pigment due to ultraviolet rays or to suppress the body color of the EL device when not emitting light. In the case of inclusion, the light emitting layer is formed so that the distribution of the content of the fluorescent pigment becomes higher toward the back electrode side in the film thickness direction of the light emitting layer (see FIGS. 5 and 9).
With this configuration, the ultraviolet light incident from the transparent electrode is absorbed by the EL phosphor particles above the light emitting layer, and the amount of ultraviolet light incident on the fluorescent pigment can be reduced, and the EL above the light emitting layer can be reduced. The phosphor particles shield the fluorescent pigment and have an effect of suppressing the body color of the EL element. Since these effects are higher as the particle size of the EL phosphor particles is smaller, it is preferable that the particle size of the EL phosphor particles is smaller. This is the same when a fluorescent pigment is contained in the dielectric layer.
When a fluorescent pigment is added to the dielectric layer, the dielectric layer is formed so that the content of the fluorescent pigment on the light emitting layer side is increased (see FIGS. 7 and 11). Light emitted from the EL phosphor particles to the dielectric layer is reflected to the transparent electrode by the dielectric particles dispersed in the dielectric layer, so it is concentrated on the light emitting layer side of the dielectric layer. It is efficient to do. In particular, when the particle size of the dielectric particles is reduced, light emitted from the EL phosphor particles is almost reflected on the upper part of the dielectric layer, and therefore, it is not used even if a fluorescent pigment is added to the back electrode side of the dielectric layer. It is preferable to add it concentrated on the light emitting layer side of the dielectric layer.
In order to make the effect of forming the above content distribution more remarkable, 50% by mass or more of the addition amount of the fluorescent pigment is 30% from the end face on the back electrode side with respect to the film thickness of the light emitting layer. Within 50% by mass or more of the added amount of the fluorescent pigment is contained in the part having a film thickness within 30% from the end face on the light emitting layer side with respect to the film thickness of the dielectric layer. It is preferable that 70% by mass or more of the addition amount of the fluorescent pigment is within 30% of the thickness of the light emitting layer from the end surface on the back electrode side or 30% of the thickness of the dielectric layer from the end surface of the light emitting layer side. It is more preferable that it is contained within the film thickness.

  As described above, the EL phosphor particle-containing coating liquid or the dielectric particle-containing coating liquid used in the manufacture of the EL element is at least the EL phosphor particles or the dielectric fine particles, the fluorescent pigment, the binder, and the binder. It is a coating liquid containing the said solvent which melt | dissolves binder. The viscosity of the EL phosphor particle-containing coating solution or the dielectric particle-containing coating solution at room temperature is preferably in the range of 0.1 Pa · s to 5 Pa · s, and in the range of 0.3 Pa · s to 1.0 Pa · s. Is particularly preferred. If the viscosity of the EL phosphor particle-containing coating solution or the dielectric particle-containing coating solution is in the above range, separation and sedimentation of the EL phosphor particles or dielectric fine particles with time lapse after dispersion of the coating film and dispersion Does not occur, and application at a relatively high speed is easy, which is preferable. The viscosity is a value measured at 16 ° C. which is the same as the coating temperature.

<Manufacturing method>
Next, a manufacturing method of the dispersion type EL element of the present invention will be described.
The manufacturing method of the present invention includes a coating liquid adjusting step for adjusting the EL phosphor particle-containing coating liquid or the dielectric particle-containing coating liquid, the EL phosphor particle-containing coating liquid on the transparent electrode, or the dielectric on the back electrode. A light emitting layer forming step or a dielectric layer forming step of applying a body particle-containing coating solution to form a light emitting layer or a dielectric layer, and fluorescence on the back electrode side or the light emitting layer side in the thickness direction of the light emitting layer or the dielectric layer It can be carried out by carrying out a drying step for drying under conditions that increase the pigment content distribution.
As described above, when the distribution of the fluorescent pigment is applied by the sedimentation speed, the layer on the side containing the fluorescent pigment is formed first. That is, when the light emitting layer contains a fluorescent pigment, a dielectric layer is laminated after forming the light emitting layer on the transparent electrode, and when the fluorescent layer is contained in the dielectric layer, After the dielectric layer is formed, the light emitting layer is laminated.
The coating liquid adjusting step can be usually performed in the same manner as this type of coating liquid.
The light emitting layer forming step and the dielectric layer forming step will be described later.
The drying process will also be described later.
In addition, another production method of the present invention is to mix and disperse the addition amount of the fluorescent pigment and mix two or more kinds of EL phosphor particle-containing coating solution or derivative particle-containing coating solution with different addition amounts of the fluorescent pigment. A coating solution adjusting step to be adjusted (hereinafter, this step is referred to as “second coating solution adjusting step”) and two or more types of EL phosphor particle-containing coating solutions are simultaneously laminated and applied, and the thickness direction of the light emitting layer In step 2, a light emitting layer forming step (hereinafter referred to as “second step”) of forming a light emitting layer in which two or more layers having different fluorescent pigment contents are laminated so that the content of the fluorescent pigment increases toward the back electrode side. Luminescent layer forming step) or two or more kinds of dielectric particle-containing coating liquids are laminated and coated at the same time, so that the fluorescent pigment content increases toward the luminescent layer side in the thickness direction of the dielectric layer. Two or more layers with different pigment contents Can be carried out by performing a dielectric layer forming step (hereinafter referred to as “second dielectric layer forming step”) for forming a dielectric layer (hereinafter referred to as “second manufacturing method”). Means this production method).
The second coating liquid adjustment step is the same as the above-described coating liquid adjustment step except that two or more types are adjusted by changing the content of the fluorescent pigment.
The second light emitting layer forming step and the second dielectric layer forming step will be described later.
The light emitting layer forming step and the dielectric layer forming step, and the second light emitting layer forming step and the second dielectric layer forming step are performed by sliding the EL phosphor particle-containing coating solution or the dielectric particle-containing coating solution. It is preferable to apply continuously on the transparent electrode or the back electrode by using a coater or an extrusion coater. At this time, the dry film thickness of the coating film of the light emitting layer is preferably in the range of 0.5 μm or more and 30 μm or less in order to increase the brightness of the EL element, and in order to suppress the light emission unevenness of the EL element. The variation is preferably 12.5% or less, particularly preferably 5% or less. Similarly, the fluctuation of the film thickness of the dielectric layer is preferably 12.5% or less, particularly preferably 5% or less, in order to suppress the light emission unevenness of the EL element.
The application of the EL phosphor particle-containing coating solution or the dielectric particle-containing coating solution in the light emitting layer forming step and the dielectric layer forming step can be suitably performed, for example, as shown in FIGS. In addition, the multilayer coating of the EL phosphor particle-containing coating film or the dielectric fine particle-containing coating film in which the addition amount of the fluorescent pigment is different in the second light emitting layer forming step and the second dielectric layer forming step is the above-described slide coater or Although application using an extrusion coater can be repeated a plurality of times, for example, it can be suitably performed by using a multistage slide coater or a multistage extrusion coater as shown in FIGS. Hereinafter, the light emitting layer forming step and the dielectric layer forming step, and the second light emitting layer forming step and the second dielectric layer forming step will be described in detail with reference to the drawings. The dielectric layer forming step and the second dielectric layer forming step are the same as the light emitting layer forming step and the second light emitting layer forming step except that the coating liquid is applied on the back electrode instead of on the transparent electrode. Therefore, in the following description, the light emitting layer forming step and the second light emitting layer forming step will be described. The dielectric formation step and the second dielectric layer formation step can be performed by applying a dielectric particle-containing coating solution on the back electrode layer by the same method.
In addition, after forming a layer containing a fluorescent pigment, the step of forming a layer to be laminated can also be carried out by applying a coating solution of a layer not containing a fluorescent pigment on the created layer in the same manner. .

FIG. 1 is a schematic explanatory view for explaining a state in which an EL phosphor particle-containing coating solution is applied onto a transparent electrode using a slide coater in the method for manufacturing an EL element of the present invention.
As shown in FIG. 1, a slide coater 3 is used as an application member for application of the EL phosphor particle-containing application liquid (A) 4 in the light emitting layer forming step. The slide coater 3 is not particularly limited and can be appropriately selected from known ones. The slide coater 3 includes an accommodating portion 3a that accommodates the EL phosphor particle-containing coating solution (A) 4 therein. When the slide coater 3 is activated, the EL phosphor particle-containing coating solution (A) 4 is accommodated. It is discharged from the part 3a to the outside through the discharge port 3b and moves on a surface inclined toward the discharge part tip 3c. The positional relationship between the slide coater 3 and the transparent electrode 1 can be appropriately selected according to the purpose. For example, the transparent electrode 1 is arranged on a plane, and the discharge portion tip 3c is located at a position facing the transparent electrode 1. You may arrange | position the slide coater 3 so that it may. In this case, the transparent electrode 1 is moved in parallel and the slide coater 3 is started. Conversely, the transparent electrode 1 is fixedly arranged and the slide coater 3 is moved in parallel from one end of the transparent electrode 1. Thus, the EL phosphor particle-containing coating solution (A) 4 can be sequentially coated on the transparent electrode 1. Furthermore, the EL phosphor particle-containing coating liquid (A) 4 is applied onto the transparent electrode 1 by moving the slide coater 3 and the transparent electrode 1 arranged opposite to each other in parallel as described above (in the same direction or in the opposite direction). It can also be applied.

  The application of the EL phosphor particle-containing coating solution (A) 4 in the light emitting layer forming step can be most suitably performed according to the following mode. That is, the slide coater 3 is arranged on the first plane, and parallel to the direction perpendicular to the discharge direction of the EL phosphor particle-containing coating liquid (A) 4 on the second plane located parallel to the first plane. In this embodiment, the transparent electrode 1 is arranged so as to be wound on the roller 2 arranged so that the rotation axis C is located. The roller 2 is particularly limited as long as it is a substrate having a circular cross section such as a so-called roller, such as a cylindrical shape or a columnar shape having an arbitrary constant inner diameter, at least in a portion where the transparent electrode 1 is disposed. Instead, it can be appropriately selected from known ones. Further, the roller internal structure can be used in any form regardless of the hollow structure, the filling structure, or the like. The transparent electrode 1 travels at a constant speed in the direction of arrow D together with the roller 2, and the EL phosphor particle-containing coating liquid (A) 4 is discharged from the slide coater 3 activated on the surface thereof, and is sequentially applied at a constant speed. The A cooling water channel 5 in FIG. 1 passes through the inside of the slide coater 3, and cooling water such as well water is circulated in the cooling water channel 5, and the slide coater 3 and the EL phosphor particle-containing coating solution (A) 4. Is kept at a constant temperature. The moving speed when moving at least one of the transparent electrode 1 and the slide coater 3 is preferably in the range of 1 m / min to 100 m / min and preferably in the range of 5 m / min to 50 m / min. More preferred. From the viewpoint of maintaining productivity, ease of speed adjustment, and stable application of the EL phosphor particle-containing coating liquid (A) 4 onto the transparent electrode 1, the relative movement speed is preferably in the above range.

In the present invention, the slide coater 3 is preferably arranged with a gap A (μm) between the discharge portion tip 3c from which the EL phosphor particle-containing coating liquid (A) 4 is discharged and the transparent electrode 1. . The gap A means the distance between the discharge portion tip 3c and the transparent electrode 1 in the shortest distance direction between the rotation axis C of the roller 2 and the discharge portion tip 3c of the EL phosphor particle-containing coating liquid (A) 4. The gap A is determined from the relationship with the film thickness B (μm) of the coating film of the EL phosphor particle-containing coating solution applied on the transparent electrode 1. In the present invention, the gap A and the film thickness B preferably satisfy the following relational expression:
0.25 × B ≦ A ≦ 0.55 × B
Furthermore, it is more preferable to satisfy the following relational expression.
0.30 × B ≦ A ≦ 0.50 × B
Suppression of streaky coating unevenness occurring on the coating surface, formation of a uniform film thickness, that is, the difference in film thickness due to coating unevenness can be suppressed within an allowable value, and application of the coating solution containing EL phosphor particles From the viewpoint of suitability and the difficulty of causing the EL phosphor particle-containing coating solution to run out during coating, the gap A desirably satisfies the above range. Furthermore, it is preferable that the thickness is within the above range, because the film thickness of the coating film at the end in the width direction of the transparent electrode does not increase, and stable winding can be performed.

In addition, the slide coater 3 is disposed on the first plane, but in the positional relationship with the roller 2, the discharge of the EL phosphor particle-containing coating liquid (A) 4 on the second plane parallel to the first plane. The rotation axis C of the roller 2 is located at a position parallel to the direction orthogonal to the direction, and the angle θ formed by the shortest distance direction between the rotation axis C and the discharge portion tip 3c and the second plane is 5 °. It is preferable to arrange in a range of 45 ° or less, and more preferable to arrange in a range of 10 ° or more and 30 ° or less.
The angle θ is preferably within the above range from the viewpoint of suppressing streaky unevenness generated on the surface of the coating film, forming a coating film having a uniform film thickness, and ease of controlling the film thickness of the coating film.
In addition, the coating of the dielectric particle-containing coating solution can be similarly performed in place of the EL phosphor particle-containing coating solution.

FIG. 3 is a schematic diagram for explaining a state in which EL phosphor particle-containing coating liquids having different amounts of fluorescent pigment added in the second light emitting layer forming step are simultaneously coated on a transparent electrode using a multistage slide coater. It is explanatory drawing.
As shown in FIG. 3, a multi-stage slide coater 3 is used as an application member for the simultaneous application of the EL phosphor particle-containing coating solution (A) 4 and the EL phosphor particle-containing coating solution (B) 6. The multistage slide coater 3 is not particularly limited and can be appropriately selected from known ones. The multistage slide coater 3 includes an accommodating portion 3a for accommodating the EL phosphor particle-containing coating liquid (A) 4 therein, and an accommodating portion 3d for accommodating the EL phosphor particle-containing coating solution (B) 6 therein. When the multi-stage slide coater 3 is activated, the EL phosphor particle-containing coating solution (A) 4 and the EL phosphor particle-containing coating solution (B) 6 are discharged from the discharge ports 3b and 3e from the storage portions 3a and 3d. Then, it moves on the surface inclined toward the discharge portion tip 3c. The positional relationship between the multi-stage slide coater 3 and the transparent electrode 1 can be appropriately selected according to the purpose. For example, the transparent electrode 1 is arranged on a plane, and the discharge portion tip 3c is located at a position facing the transparent electrode 1. The multistage slide coater 3 may be disposed so as to be positioned. In this case, the transparent electrode 1 is moved in parallel and the multistage slide coater 3 is started. Conversely, the transparent electrode 1 is fixedly arranged, and the multistage slide coater 3 is moved in parallel from one end of the transparent electrode 1. By doing so, the EL phosphor particle-containing coating liquid (A) 4 and the EL phosphor particle-containing coating liquid (B) 6 can be simultaneously coated on the transparent electrode 1. Furthermore, the EL phosphor particle-containing coating solution (A) 4 is formed on the transparent electrode 1 by moving the multi-stage slide coater 3 and the transparent electrode 1 facing each other as described above in parallel (in the same direction or in the opposite direction). And the EL phosphor particle-containing coating solution (B) 6 can be simultaneously coated. By further increasing the number of stages of the multi-stage slide coater, it is possible to simultaneously apply EL phosphor particle-containing coating liquids with different amounts of fluorescent pigment added. The most suitable conditions for simultaneous application using a multi-stage slide coater are the same as the most suitable conditions for applying the light emitting layer as a single layer using the above-mentioned slide coater.
In addition, the application of the dielectric particle-containing coating solution having a different amount of the fluorescent pigment can be similarly performed in place of the EL phosphor particle-containing coating solution.

FIG. 2 is a schematic explanatory view for explaining a state in which the EL phosphor particle-containing coating liquid in the light emitting layer forming step is coated on the transparent electrode using an extrusion coater.
As shown in FIG. 2, an extrusion coater 3 is used as a coating member for coating the EL phosphor particle-containing coating solution. The extrusion coater 3 is not particularly limited and can be appropriately selected from known apparatuses. The extrusion coater 3 includes an EL phosphor particle-containing coating liquid container 3a for accommodating the EL phosphor particle-containing coating liquid (A) 4 therein, and a tip discharge port 3b. The extrusion coater 3 is activated. Then, the EL phosphor particle-containing coating liquid (A) 4 is discharged from the container 3a to the outside through the tip discharge port 3b. The positional relationship between the extrusion coater 3 and the transparent electrode 1 can be appropriately selected according to the purpose. For example, the transparent electrode 1 is arranged on a plane, and the tip discharge port 3b is located at a position facing the transparent electrode 1. The extrusion coater 3 may be arranged so as to be positioned. In this case, for example, either one of the extrusion coater 3 or the transparent electrode 1 is fixedly arranged, the other is sequentially translated, and the extrusion coater 3 is activated, so that the EL fluorescence is applied to the surface of the transparent electrode 1. The body particle-containing coating solution (A) 4 can be applied. Moreover, the EL phosphor particle-containing coating solution (A) 4 is formed on the surface of the transparent electrode 1 by translating the extrusion coater 3 and the transparent electrode 1 that are arranged to face each other as described above (in the same direction or in the opposite direction). Can also be applied.

In the method for producing an EL device of the present invention, the application of the EL phosphor particle-containing coating solution can be most suitably performed according to the following embodiment. That is, the extrusion coater 3 is disposed on the first plane, and the EL phosphor particles are contained in the second plane located above the tip discharge port 3b of the extrusion coater 3 and parallel to the first plane. In this mode, the transparent electrode 1 is disposed on the roller 2 on which the axial center C is positioned in parallel with the direction orthogonal to the discharge direction of the coating liquid (A) 4. The roller 2 is not particularly limited as long as it is a cylindrical or columnar substrate having an arbitrary constant diameter in the portion where the transparent electrode is disposed. The transparent electrode 1 moves at a constant speed in the direction indicated by the arrow D together with the roller 2, and the EL phosphor particles discharged from the EL phosphor particle-containing coating solution storage unit 3 a on the surface of the transparent electrode 1 when the extrusion coater 3 is activated. The containing coating liquid (A) 4 is sequentially applied at a constant speed. The cooling water channel 5 in FIG. 2 passes through the inside of the extrusion coater 3, and in order to keep the extrusion coater 3 and the EL phosphor particle-containing coating liquid (A) 4 at a constant temperature, Cooling water such as well water is circulated. The movement speed when moving at least one of the extrusion coater 3 and the transparent electrode 1 is preferably in the range of 1 m / min to 100 m / min, and in the range of 5 m / min to 50 m / min. Is more preferable.
From the viewpoint of maintaining productivity, ease of speed adjustment, and stable application of the EL phosphor particle-containing coating liquid (A) 4 onto the transparent electrode 1, the relative movement speed is preferably in the above range.

The extrusion coater 3 is preferably disposed with a gap A (μm) between the tip discharge port 3b from which the EL phosphor particle-containing coating solution (A) 4 is discharged and the transparent electrode 1. This gap A (μm) means the shortest distance between the tip discharge port 3b from which the EL phosphor particle-containing coating solution (A) 4 is discharged and the transparent electrode 1, and the EL phosphor applied on the transparent electrode 1 It is determined from the relationship with the film thickness B (μm) of the coating film of the particle-containing coating solution (A) 4. In the present invention, the gap A (μm) and the film thickness B (μm) of the coating film preferably satisfy the following relational expression:
0.75 × B + 100 ≦ A ≦ 1.10 × B + 130
It is particularly preferable that the following relational expression is satisfied.
0.80 × B + 110 ≦ A ≦ 1.05 × B + 130
Suppression of coating streaks that cannot be eliminated, suppression of coating unevenness such that the difference in film thickness within the same plane exceeds the allowable value, prevention of unwinding due to thick edges, From the viewpoint of ease of coating suitability and prevention of liquid breakage of the EL phosphor particle-containing coating solution (A) 4 during coating, the gap A (μm) between the tip discharge port 3b of the extrusion coater 3 and the transparent electrode 1 ) Is preferably within the above range.

Further, the extrusion coater 3 is disposed on the first plane. At this time, the EL phosphor particle-containing coating solution on the second plane located in parallel with the first plane in the positional relationship with the roller 2. (A) The axis C of the roller 2 is positioned in parallel with the direction orthogonal to the discharge direction of 4, and the angle θ between the shortest distance direction between the tip discharge port 3b and the roller 2 and the second plane is 0 °. The range of 30 ° or less is preferable, and the range of 0 ° or more and 25 ° or less is particularly preferable.
From the viewpoint of suppressing the thickness unevenness of the light emitting layer, the angle θ formed by the shortest distance direction between the tip discharge port 3b of the extrusion coater 3 and the roller 2 and the second plane is preferably within the above range. .
Further, the angle α formed between the discharge direction of the EL phosphor particle-containing coating liquid (A) 4 and the second plane is preferably in the range of 5 ° to 60 °, and particularly preferably in the range of 5 ° to 30 °. .
From the viewpoint of suppressing the occurrence of light-emitting layer coating streaks and preventing the occurrence of unevenness in the light-emitting layer thickness, the angle α formed between the discharge direction of the EL phosphor particle-containing coating liquid (A) 4 and the second plane is as described above. It is preferable to be within the range.

FIG. 4 is a diagram for explaining a state in which EL phosphor particle-containing coating liquids having different amounts of fluorescent pigment added in the second light emitting layer forming step are simultaneously coated on a transparent electrode using a multistage extrusion coater. It is a schematic explanatory drawing.
As shown in FIG. 4, a multi-stage extrusion coater 3 is used as an application member for simultaneous application of EL phosphor particle-containing application liquids with different amounts of fluorescent pigment added. The multistage extrusion coater 3 is not particularly limited and can be appropriately selected from known apparatuses. The multistage extrusion coater 3 includes an accommodating portion 3a for accommodating the EL phosphor particle-containing coating liquid (A) 4 therein, an accommodating portion 3d for accommodating the EL phosphor particle-containing coating liquid (B) 6 therein, and a tip discharge. When the multistage extrusion coater 3 is activated, the EL phosphor particle-containing coating liquid (A) 4 and the EL phosphor particle-containing coating liquid (B) 6 are contained in the accommodating portions 3a and 3d, respectively. From the tip discharge ports 3b and 3e. The positional relationship between the multistage extrusion coater 3 and the transparent electrode 1 can be appropriately selected according to the purpose. For example, the transparent electrode 1 is arranged on a plane, and the tip discharge port 3b is located at a position facing the transparent electrode 1. And the multistage extrusion coater 3 may be arranged so that 3e is located. In this case, for example, either the multi-stage extrusion coater 3 or the transparent electrode 1 is fixedly arranged, the other is sequentially translated, and the multi-stage extrusion coater 3 is activated to thereby form the surface of the transparent electrode 1. The EL phosphor particle-containing coating solution (A) 4 and the EL phosphor particle-containing coating solution (B) 6 can be applied simultaneously. In addition, the multi-stage extrusion coater 3 and the transparent electrode 1 that are arranged to face each other as described above are moved in parallel (in the same direction or in the opposite direction), so that the EL phosphor particle-containing coating liquid (A) is formed on the surface of the transparent electrode 1. 4 and EL phosphor particle-containing coating solution (B) 6 can also be applied. By further increasing the number of stages of the multi-stage extrusion coater, light emitting layers having different amounts of fluorescent pigment can be applied simultaneously. The most suitable conditions for simultaneous coating using a multi-stage extrusion coater are the same as the most suitable conditions for coating the light emitting layer as a single layer using the aforementioned extrusion coater.
In addition, the application of the dielectric particle-containing coating solution having a different amount of the fluorescent pigment can be similarly performed in place of the EL phosphor particle-containing coating solution.

From the light emitting layer or dielectric layer forming step to the drying step, each is preferably a continuous step. Although the drying process is also performed in the second manufacturing method, it is not necessary to form the content distribution according to the drying conditions. Therefore, the drying performed after the light emitting layer forming process and the dielectric layer forming process containing the fluorescent pigment is performed. It is not necessary to set conditions as much as the process.
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. When dried quickly, only the surface is dried and convection occurs in the coating film, so-called Benard cell is likely to occur, and blister failure is likely to occur due to rapid expansion of the solvent, and the uniformity of the coating film may be significantly impaired. There is. On the other hand, if the final drying temperature is low, the solvent remains in each functional layer, which may affect the subsequent process of forming an EL element such as a lamination process of a moisture-proof film.
Therefore, in order to obtain a desired content distribution, it is preferable that the drying step is performed slowly at a constant rate drying step and performed at a temperature sufficient for the solvent to dry. As a method of slowly performing the constant rate drying step, it is preferable to divide the drying chamber where the transparent electrode travels into several zones and to gradually increase the drying temperature after the coating step from about 40 ° C. .

  In the present invention, it is preferable to perform a calendar process on the light emitting layer using a calendar processor. The smoothness of both main surfaces of the light emitting layer formed by calendering is preferably in the range of 0.01 μm to 0.5 μm, and more preferably 0.2 μm or less. The calendar processing machine to be used is not particularly limited, and can be appropriately selected from known apparatuses. The calendar processing machine performs a smoothing process by passing an object while applying pressure between a pair of rolls in which at least one is heated. The roll surface is made of a mirror-polished metal. In order to prevent transfer of the object to be processed to the calendar roll, the roll surface may be coated with Teflon. The backup roll facing the calendar roll may be made of either metal or plastic, but the plastic roll is preferable because the buffering action works to remove excess stress. Further, the backup roll preferably has a larger outer diameter than the calendar roll, and in order to prevent the calendar roll from slipping, it is preferable that the drive mechanism be held only by the backup roll and the calendar roll be a mechanism that freely rotates. . On the contrary, it is preferable that the pressurizing mechanism is provided on the calender roll in terms of pressurization uniformity. In the calendering process, it is preferable that the heating temperature of the calender roll is equal to or higher than the softening temperature of the binder contained in the light emitting layer. In addition, the calendar pressure and the conveyance speed can obtain the necessary smoothness in consideration of the calendar temperature and the coating width of the light emitting layer so as not to destroy the EL phosphor particles or extend the light emitting layer more than necessary. It is preferable to select appropriately.

<Electrode>
In the EL device of the present invention, any transparent electrode material that is generally used is used as the transparent electrode. Examples thereof include oxides such as tin-doped tin oxide, antimony-doped tin oxide, and zinc-doped tin oxide, a multilayer structure in which a silver thin film is sandwiched between high refractive index layers, and π-conjugated polymers such as polyaniline and polypyrrole. It is also preferred to improve the conductivity by arranging a comb-type or grid-type fine metal wire on these transparent electrodes. The specific resistivity of the transparent electrode is preferably in the range of 0.01Ω / □ to 30Ω / □.
For the back electrode on the side from which light is not extracted, any conductive material can be used. It is selected appropriately from gold, silver, platinum, copper, iron, aluminum and other metals, graphite, etc. depending on the form of the element to be created, the temperature of the creation process, etc. It may be used. Further, both electrodes can be prepared by preparing a conductive material-containing coating solution in which the conductive fine particle material is dispersed together with a binder, and using the above-described slide coater or extrusion coater.

  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 tin oxide, and a multilayer structure in which a thin film of silver is sandwiched between high refractive index layers It is preferable to use transparent electrode materials such as π-conjugated polymers such as polyaniline and polypyrrole. In addition, when a compensation electrode is provided outside the back electrode from which light is not extracted, any conductive material such as metal such as gold, silver, platinum, copper, iron, aluminum, graphite, etc. can be used. A transparent electrode such as ITO may be used as long as it has the property. The compensation electrode is attached to the transparent electrode or the back electrode via 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, coating, or the like. Alternatively, 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 the above-described slide coater or extrusion 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 driving power supply. At this time, the vibration generated in the light emitting layer can be offset by setting the phase opposite to that of the voltage applied to the light emitting layer. The compensation electrode has the same effect even if it is attached to either the outside of the transparent electrode or the outside of the back electrode with an insulating layer sandwiched between them. It is preferable because it is possible. In order to effectively suppress vibrations, it is preferable to adjust the dielectric constant of the light emitting layer (and the dielectric layer) and the dielectric constant of the insulating layer inside the compensation electrode to be substantially equal.

<Other layers applicable to EL elements>
As another method for suppressing vibration of the EL element, a buffer material layer can be provided. In this case, it is preferable to use a polymer material having a high impact absorbing ability or a polymer material foamed by adding a foaming agent. Examples of polymer materials with high impact absorption include natural rubber, styrene butadiene rubber, polyisoprene rubber, polybutadiene rubber, nitrile rubber, chloroprene rubber, butyl rubber, hyperon, silicon rubber, urethane rubber, ethylene propylene rubber, and fluorine rubber. 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, fluorine rubber, and the like are more preferable because they have low water absorption and function as a protective film that protects 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 sticking 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 apply | coat using the above-mentioned slide coater or extrusion coater. Although the thickness of the buffer material 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. When the thickness is 200 μm or more, the thickness of the element is greatly increased, which is not preferable in terms of mass and flexibility. Further, the combined use of the compensation electrode and the buffer material layer is preferable because vibration can be further suppressed.

  However, since the above-described vibration suppression technology alone is insufficient for the generation of vibration that increases due to the increase in the area of the EL element, it is preferable to obtain a synergistic effect in combination with a thinned light emitting layer. When the light emitting layer is thinned, the voltage applied to the light emitting layer is higher than that in the case where the light emitting layer is thick as in the conventional EL element under the same driving conditions, so that the luminance is increased. In the case of driving with a luminance comparable to that of a conventional EL element, the driving voltage and frequency can be lowered, so that vibration and noise can be further improved. In order to obtain such an effect, the light emitting layer preferably has a thickness of 0.5 μm or more and 30 μm or less, and particularly preferably 15 μm or less. Furthermore, the total film thickness of the dielectric layer containing the inorganic phosphor material that includes the EL phosphor particle material in contact with the dielectric material in the light emitting layer, and adjoins the light emitting layer containing the EL phosphor particle material as necessary, The average particle size of the EL phosphor particles is preferably in the range of 3 to 10 times. The contact between the EL phosphor particle material and the dielectric material is preferably that the EL phosphor particle material is completely or partially covered with the non-light emitting shell layer. However, the EL phosphor particle material and the dielectric material may simply be in contact. The lower limit of the element thickness is the EL phosphor particle size, but in order to ensure the smoothness of the element, the element thickness is in the range of 3 to 10 times the size of the EL phosphor particle. Preferably there is. The thickness of the element here refers to the total thickness of the light emitting layer including the EL phosphor particles sandwiched between the electrodes and the dielectric layer adjacent thereto. In this case, the total thickness is preferably 1 μm or more and 50 μm or less, and particularly preferably 30 μm or less.

<Particle size of phosphor particles>
As the EL phosphor particles used in the present invention, it is preferable to use particles having an average particle diameter (sphere equivalent diameter) in the range of 0.1 μm to 15 μm in order to uniformly form a light emitting layer of 30 μm or less. More preferably, it is the range of 0.5 to 10 μm. By setting the particle size of the EL phosphor particles to 15 μm or less, the uniformity of the coating film thickness of the light emitting layer is improved, and the smoothness of the coating film surface is also improved. Furthermore, when the number of particles per unit area is greatly increased, fine light emission unevenness can be remarkably improved. For example, when EL phosphor particles having an average particle diameter of 10 μm are used compared with the conventional case where EL phosphor particles having an average particle diameter of 20 μm are used, it is simply 8 times per unit area at the same coating mass. If an increase in the number of particles is obtained and the average particle diameter is 1 μm, an increase in the number of particles per unit area of 8000 times can be obtained, and the uniformity of light emission can be improved. Further, the decrease in the particle size leads to an increase in the applied voltage of the EL phosphor particles, which is preferable for improving the luminance of the EL element together with an increase in the electric field strength to the light emitting layer due to the thinning of the light emitting layer. It is also preferable for suppressing vibrations.

<Dielectric material shape>
In addition, the dielectric substance of the present invention may be a thin film crystal layer or a particle shape, or a combination thereof, but is preferably a particle shape. The dielectric layer containing the dielectric substance may be provided on one side of the light emitting layer, and is preferably provided on both sides of the light emitting layer. When the dielectric layer is formed by coating, it is preferable to use a slide coater or an extrusion coater similarly to the light emitting layer. In the case of a thin film crystal layer, it may be a thin film formed on a substrate by a vapor phase method such as sputtering, or a sol-gel film using an alkoxide such as Ba or Sr. In the case of particle shape, it is preferable that the size is sufficiently small with respect to the size of the EL phosphor particles. Specifically, a size in the range of 1/1000 to 1/3 of the EL phosphor particle size is preferable.

<Sealing>
The dispersion-type EL element of the present invention is preferably processed so as to eliminate the influence of humidity and oxygen from the external environment using a sealing film. Sealing film for sealing the EL element is preferably not more than the water vapor transmission rate of 0.05g / m ² / day at 40 ° C. -90% RH, more preferably at most 0.01g / m ² / day. Furthermore, the oxygen permeability at 40 ° C.-90% RH is preferably 0.1 cm ³ / m ² / day / atm or less, more preferably 0.01 cm ³ / m ² / day / atm or less. As such a sealing film, a laminated film of an organic film and an inorganic film is preferably used. As the organic film, a polyethylene resin, a polypropylene resin, a polycarbonate resin, a polyvinyl alcohol resin, or the like is preferably used, and in particular, a polyvinyl alcohol resin can be more preferably used. Since polyvinyl alcohol resins and the like have water absorption properties, it is more preferable to use a resin that has been dried in advance by a treatment such as vacuum heating.
An inorganic film is deposited by vapor deposition, sputtering, CVD, or the like on these resins processed into a sheet by a method such as coating. As the inorganic film to be deposited, silicon oxide, silicon nitride, silicon oxynitride, silicon oxide / aluminum oxide, aluminum nitride, or the like is preferably used, and silicon oxide is particularly 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 on which the inorganic film is deposited is attached to the adhesive layer. It is preferable that a plurality of sheets are laminated to form a multilayer film.
The thickness of the organic film is preferably in the range of 5 μm to 300 μm, and more preferably in the range of 10 μm to 200 μm. The thickness of the inorganic film is preferably in the range of 10 nm to 300 nm, and more preferably in the range of 20 nm to 200 nm. The thickness of the laminated sealing film is preferably in the range of 30 μm to 1000 μm, and more preferably in the range of 50 μm to 300 μm. For example, in order to obtain a sealing film having a water vapor transmission rate of 0.05 g / m ² / day or less at 40 ° C.-90% RH, the structure in which two layers of the organic film and the inorganic film are laminated is 50. A film thickness of ˜100 μm is sufficient, but polychlorinated ethylene trifluoride conventionally used as a sealing film requires a film thickness of 200 μm or more. The thinner the sealing film, the better in terms of light transmission and device flexibility.

  When sealing an EL element with this sealing film, even if the EL element is sandwiched between two sealing films and the periphery is adhesively sealed, the sealing film overlaps by folding one sealing film in half The part may be adhesively sealed. As the EL element sealed with the sealing film, only the EL element may be separately prepared, or the EL element may be directly formed on the sealing film. The sealing step is preferably performed in a dry atmosphere with vacuum or dew point management.

  Even when advanced sealing is performed, it is preferable to dispose a desiccant layer around the EL element. As the desiccant used for the desiccant layer, alkaline earth metal oxides such as CaO, SrO, BaO, aluminum oxide, 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 also be used in the form of powder, but for example, a material that is mixed with a resin material and processed into a sheet by application or molding, or a coating liquid mixed with a resin material is dispensed It is preferable to dispose the desiccant layer by applying it around the EL element. Furthermore, it is more preferable to cover not only the periphery of the EL element but also the lower and upper surfaces of the EL element 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, a polyamide-based resin or the like can be used.

  Examples of the EL element of the present invention are described below, but the examples of the present invention are not limited to the following examples. In addition, in a present Example, the viscosity of each coating liquid uses a viscometer (VISCONIC ELD.R and VISCOMETER CONTROLLER E-200 rotor No.71, Tokyo Keiki Co., Ltd. product), and is stirring (rotation speed: 20 rpm). , And measured at a liquid temperature of 16 ° C.

<Preparation of EL phosphor particle-containing coating solution>
ZnS: Cu, ClEL phosphor particles emitting blue-green light with an average particle size of 5 μm as EL phosphor particles, cyanoresin (manufactured by Shin-Etsu Chemical Co., Ltd .; CR-S) as a binder, rhodamine emitting red light with an average particle size of 0.4 μm Dimethylformamide (DMF) is prepared as a solvent for dissolving the fluorescent pigment and binder. The following composition was added to a DMF organic solvent and dispersed with a propeller mixer (rotation speed: 3000 rpm), and then a fluorescent pigment was added and dispersed with a propeller mixer (1000 rpm). Further, an EL phosphor particle-containing coating solution having a viscosity at 16 ° C. of 0.5 Pa · s was prepared.
EL phosphor particles (ZnS: Cu, Mn, Cl) 100 parts by mass Cyanoresin 25 parts by weight Fluorescent pigment X parts X 1.0, 0 0.1 and 0, and EL phosphor particle-containing coating solution (a), EL phosphor particle-containing coating solution (b), and EL phosphor particle-containing coating solution (c), respectively.

<Preparation of coating solution containing dielectric particles>
Barium titanate particles having an average particle size of 0.5 μm as dielectric particles, cyanoresin (manufactured by Shin-Etsu Chemical Co., Ltd .; CR-S) as a binder, rhodamine-based fluorescent pigment and binder having an average particle size of 0.4 μm Prepare DMF as solvent to dissolve. The following composition was added to a DMF organic solvent and dispersed with a propeller mixer (rotation speed: 3000 rpm), and then a fluorescent pigment was added and dispersed with a propeller mixer (1000 rpm). Further, a dielectric particle-containing coating solution having a viscosity at 16 ° C. of 0.5 Pa · s was prepared.
Barium titanate: 90 parts by weight Cyanoresin: 30 parts by weight Fluorescent pigment: Y parts by weight Y is 1.0, 0.1 and 0, respectively, and dielectric particles Containing coating solution (a) ′, dielectric particle-containing coating solution (b) ′, and dielectric particle-containing coating solution (c) ′.

(Example 1)
A roller having a circular cross section and a slide coater are arranged so as to face each other, and a coating apparatus similar to that shown in FIG. 1 in which a transparent electrode is wound on the roller is prepared. The liquid (a) was introduced into the accommodating portion 3a in the slide coater 3 by a liquid feed pump. Polyethylene terephthalate (thickness: 100 μm) on which an ITO transparent electrode was sputtered as a transparent electrode was provided so as to wind the roller 2, and the roller 2 was rotated at a constant speed in the direction of arrow D. In the slide coater 3, the gap A between the discharge portion tip 3 c and the transparent electrode 1 in the shortest distance direction between the rotation axis C of the roller 2 and the discharge portion tip 3 c of the slide coater 3 is set to 50 μm. The angle θ formed by the shortest distance direction between the axis C and the discharge portion tip 3c and the horizontal plane was set to 15 °. Further, a cooling water channel 5 was provided in the slide coater 3, and the temperature of the slide coater 3 and the EL phosphor particle-containing coating solution (a) 4 was maintained at about 16 ° C. by circulating well water. The slide coater 3 is activated, and the EL phosphor particle-containing coating solution (a) accommodated in the accommodating portion 3a is discharged from the discharge port 3b in a constant amount so that the target film thickness of the dry coating film is 20 μm. did. On the other hand, the moving speed of the transparent electrode 1 traveling in the direction of the arrow D is set to a constant speed of 10 m / min. Further, the transparent electrode 1 moves along the inclination from the discharge port 3b and is continuously applied to the transparent electrode 1 with a width of 2 m for 1000 m. . Next, drying is performed in a drying chamber in which the drying temperature changes stepwise from 40 ° C. to 120 ° C., where the zone from 40 ° C. to 80 ° C. is set to ½ of the total drying time. Thus, a sheet-like laminate having a light emitting layer formed on ITO was obtained.

A dielectric layer, a back electrode layer, and a sealing film were formed on the sheet-like laminate obtained as described above to produce an EL element. The sheet-like laminate is placed again on the coating apparatus on which the above-described slide coater is placed, and the dielectric particle-containing coating solution (c) ′ is applied in the same manner as the coating of the light emitting layer, and the dry film thickness of the coating film is 20 μm. The sheet-like laminate was applied and dried at a moving speed of 10 m / min to obtain a sheet-like laminate in which a light emitting layer and a dielectric layer were laminated on ITO. An aluminum foil having a thickness of 30 μm was pasted thereon as a back electrode, and then a sheet-like laminate having a size of 1 m × 1 m was cut out. Thereafter, lead wires for supplying a voltage to the transparent electrode and the back electrode were attached, and the whole was sealed with a sealing film to obtain an EL element having the configuration of FIG.
That is, as shown in FIG. 5, the obtained EL element includes a transparent electrode 7, a light emitting layer 9a formed over the transparent electrode 7, a dielectric layer 10 formed over the light emitting layer 9a, The fluorescent pigment 8 is dispersed in the light emitting layer 9a, and the fluorescent pigment 8 is distributed in the dielectric layer 10 side as shown in FIG. That is, the back electrode 11 side is high. Specifically, it was confirmed that 70% of the added fluorescent pigment was contained in the light emitting layer having a depth of 5 μm from the interface between the light emitting layer and the dielectric layer.

(Example 2)
A coating device similar to that shown in FIG. 1 in which a roller having a circular cross section and a slide coater are arranged so as to face each other and a transparent electrode is wound on the roller is prepared. (A) ′ was introduced into the accommodating portion 3a in the slide coater 3 by a liquid feed pump. An aluminum plate (thickness: 100 μm) was provided as a transparent electrode so as to wind the roller 2, and the roller 2 was rotated so as to run at a constant speed in the direction of arrow D. In the slide coater 3, the gap A between the discharge portion tip 3 c and the transparent electrode 1 in the shortest distance direction between the rotation axis C of the roller 2 and the discharge portion tip 3 c of the slide coater 3 is set to 50 μm. The angle θ formed by the shortest distance direction between the axis C and the discharge portion tip 3c and the horizontal plane was set to 15 °. Further, a cooling water channel 5 is provided in the slide coater 3, and the temperature of the slide coater 3 and the dielectric particle-containing coating liquid (a) ′ 4 is maintained at about 16 ° C. by circulating the well water. The slide coater 3 is started, and the dielectric particle-containing coating solution (a) ′ accommodated in the accommodating portion 3a is discharged from the discharge port 3b in a constant amount so that the target film thickness of the dry coating film becomes 20 μm by the liquid feed pump. did. On the other hand, the moving speed of the transparent electrode 1 traveling in the direction of the arrow D is set to a constant speed of 10 m / min. Further, the transparent electrode 1 moves along the inclination from the discharge port 3b and is continuously applied to the transparent electrode 1 with a width of 2 m for 1000 m. . Next, drying is performed in a drying chamber in which the drying temperature changes stepwise from 40 ° C. to 120 ° C., where the zone from 40 ° C. to 80 ° C. is set to ½ of the total drying time. Thus, a sheet-like laminate having a dielectric layer formed on an aluminum plate was obtained.

A light emitting layer, a transparent electrode layer, and a sealing film were formed on the sheet-like laminate obtained as described above to produce an EL element. The sheet-like laminate is placed again on the coating apparatus on which the above-mentioned slide coater is placed, and the EL phosphor particle-containing coating solution (c) is applied in the same manner as the coating of the dielectric layer so that the dry film thickness of the coating film The sheet-like laminate was applied and dried at a moving speed of 10 m / min so as to be 20 μm, thereby obtaining a sheet-like laminate in which a dielectric layer and a light emitting layer were laminated on an aluminum plate. On top of that, ITO formed by sputtering on a 100 μm thick polyethylene terephthalate film as a transparent electrode was bonded, and then a sheet-like laminate having a size of 1 m × 1 m was cut out. Thereafter, a lead wire for supplying a voltage to the transparent electrode and the back electrode was attached, and the whole was sealed with a sealing film to obtain an EL element having the configuration of FIG.
That is, as shown in FIG. 7, the obtained EL element includes a transparent electrode 7, a light emitting layer 9 c formed over the transparent electrode 7, a dielectric layer 10 a formed over the light emitting layer 9 c, The back surface electrode 11 is provided so as to overlap the dielectric layer 10a. The fluorescent pigment 8 is dispersed in the dielectric layer 10a, and the distribution of the fluorescent pigment 8 is as shown in FIG. It is expensive. Specifically, it was confirmed that 65% of the added fluorescent pigment was contained in the dielectric layer having a depth of 5 μm from the interface between the light emitting layer and the dielectric layer.

(Example 3)
An EL phosphor particle obtained by preparing a coating device similar to that shown in FIG. 3 in which a roller having a circular cross section and a two-stage slide coater are arranged to face each other and a transparent electrode is wound around the roller. The containing coating liquid (a) and the EL phosphor particle-containing coating liquid (b) were introduced into the accommodating portions 3d and 3a in the two-stage slide coater 3 by a liquid feed pump. Polyethylene terephthalate (thickness: 100 μm) on which an ITO transparent electrode was sputtered as a transparent electrode was provided so as to wind the roller 2, and the roller 2 was rotated at a constant speed in the direction of arrow D. The two-stage slide coater 3 has a gap A between the discharge portion tip 3c and the transparent electrode 1 in the shortest distance direction between the rotation axis C of the roller 2 and the discharge portion tip 3c of the two-stage slide coater 3, The angle θ formed by the horizontal distance between the rotation axis C of the roller 2 and the discharge portion tip 3c and the horizontal plane was set to 15 °. Further, a cooling water channel 5 is provided in the two-stage slide coater 3, and the well water is circulated to circulate the two-stage slide coater 3, the EL phosphor particle-containing coating solution (a) 6, and the EL phosphor particle-containing coating solution. (B) The temperature of 4 was maintained at about 16 ° C. The two-stage slide coater 3 is activated, and the EL phosphor particle-containing coating solution (b) accommodated in the accommodating portion 3a by the liquid feed pump and the EL phosphor particle-containing coating solution (a) accommodated in the accommodating portion 3d. Then, the film was discharged from the discharge ports 3b and 3e in a fixed amount so that the target film thickness of the dried coating film was 10 μm. On the other hand, the moving speed of the transparent electrode 1 traveling in the direction of the arrow D is a constant speed of 10 m / min, moves along the inclination from the discharge ports 3b and 3e, and continues on the transparent electrode 1 for 1000 m with a width of 2 m. Applied. Next, drying is performed in a drying chamber in which the drying temperature changes stepwise from 40 ° C. to 120 ° C., where the zone from 40 ° C. to 80 ° C. is set to ½ of the total drying time. Thus, a sheet-like laminate having a light emitting layer formed on ITO was obtained.

A dielectric layer, a back electrode layer, and a sealing film were formed on the sheet-like laminate obtained as described above to produce an EL element. The sheet-like laminate is placed again on the coating apparatus on which the above-mentioned slide coater is placed, and the coating solution containing dielectric fine particles (c) ′ is applied in the same manner as the coating of the light emitting layer, and the dry film thickness of the coating film is 20 μm. The sheet-like laminate was applied and dried at a moving speed of 10 m / min to obtain a sheet-like laminate in which a light emitting layer and a dielectric layer were laminated on ITO. An aluminum foil having a thickness of 30 μm was pasted thereon as a back electrode, and then a sheet-like laminate having a size of 1 m × 1 m was cut out. Thereafter, lead wires for supplying a voltage to the transparent electrode and the back electrode were attached, and the whole was sealed with a sealing film to obtain an EL element having the configuration of FIG.
That is, as shown in FIG. 9, the obtained EL element has a transparent electrode 7, light emitting layers 9b, 9a having a two-layer structure formed on the transparent electrode 7, and a light emitting layer 9a. It consists of the formed dielectric layer 10c and the back electrode 11 provided so as to overlap the dielectric layer 10c. The fluorescent pigment 8 is dispersed in the light emitting layers 9a and 9b, and the distribution of the fluorescent pigment 8 is the light emitting layer. Since 9a is higher than the light emitting layer 9b, the distribution of the fluorescent pigment in the entire light emitting layer is higher on the dielectric layer 10c side, that is, on the back electrode 11 side as shown in FIG. Specifically, it was confirmed that 75% of the added fluorescent pigment was contained in the light emitting layer having a depth of 5 μm from the interface between the light emitting layer and the dielectric layer.

Example 4
A roller having a circular cross section and a two-stage slide coater are arranged so as to face each other, and a coating device similar to that shown in FIG. 3 in which a transparent electrode is wound on the roller is prepared. The coating liquid (a) ′ and the dielectric particle-containing coating liquid (b) ′ were introduced into the accommodating portions 3d and 3a in the two-stage slide coater 3 by a liquid feeding pump. An aluminum plate (thickness: 100 μm) was provided as a transparent electrode so as to wind the roller 2, and the roller 2 was rotated so as to run at a constant speed in the direction of arrow D. The two-stage slide coater 3 has a gap A between the discharge portion tip 3c and the transparent electrode 1 in the shortest distance direction between the rotation axis C of the roller 2 and the discharge portion tip 3c of the two-stage slide coater 3, The angle θ formed by the horizontal distance between the rotation axis C of the roller 2 and the discharge portion tip 3c and the horizontal plane was set to 15 °. In addition, a cooling water channel 5 is provided in the two-stage slide coater 3, and the two-stage slide coater 3, the dielectric particle-containing coating liquid (a) '6 and the dielectric particle-containing coating liquid ( b) The temperature of '4 was kept at about 16 ° C. The two-stage slide coater 3 is activated, and the dielectric particle-containing coating liquid (b) ′ housed in the housing part 3a by the liquid feed pump and the dielectric particle-containing coating liquid (a) ′ housed in the housing part 3d Then, the film was discharged from the discharge ports 3b and 3e in a fixed amount so that the target film thickness of the dried coating film was 10 μm. On the other hand, the moving speed of the transparent electrode 1 traveling in the direction of the arrow D is a constant speed of 10 m / min, moves along the inclination from the discharge ports 3b and 3e, and continues on the transparent electrode 1 for 1000 m with a width of 2 m. Applied. Next, drying is performed in a drying chamber in which the drying temperature changes stepwise from 40 ° C. to 120 ° C., where the zone from 40 ° C. to 80 ° C. is set to ½ of the total drying time. Thus, a sheet-like laminate having a dielectric layer formed on an aluminum plate was obtained.

A light emitting layer, a transparent electrode layer, and a sealing film were formed on the sheet-like laminate obtained as described above to produce an EL element. The sheet-like laminate is placed again on the coating apparatus on which the above-mentioned slide coater is placed, and the EL phosphor particle-containing coating solution (c) is applied in the same manner as the coating of the dielectric layer so that the dry film thickness of the coating film The sheet-like laminate was applied and dried at a moving speed of 10 m / min so as to be 20 μm, thereby obtaining a sheet-like laminate in which a dielectric layer and a light emitting layer were laminated on an aluminum plate. On top of that, ITO formed by sputtering on a 100 μm thick polyethylene terephthalate film as a transparent electrode was bonded, and then a sheet-like laminate having a size of 1 m × 1 m was cut out. Then, the lead wire for supplying a voltage to a transparent electrode and a back electrode was attached, and the whole was sealed with the sealing film, and the EL element of the structure of FIG. 11 was obtained.
That is, as shown in FIG. 11, the obtained EL device has a laminated structure of a transparent electrode 7, a light emitting layer 9c formed on the transparent electrode 7, and a two-layer laminated structure formed on the light emitting layer 9c. Dielectric layers 10a and 10b and a back electrode 11 provided on the dielectric layer 10b. The fluorescent pigment 8 is dispersed in the dielectric layers 10a and 10b, and the distribution of the fluorescent pigment 8 is dielectric. Since the body layer 10a is higher than the dielectric layer 10b, the distribution of the fluorescent pigment is higher on the light emitting layer 9c side as shown in FIG. Specifically, it was confirmed that 70% of the added fluorescent pigment was contained in the dielectric layer having a depth of 5 μm from the interface between the light emitting layer and the dielectric layer.

(Comparative example)
A roller having a circular cross section and a slide coater are arranged so as to face each other, and a coating apparatus similar to that shown in FIG. 1 in which a transparent electrode is wound on the roller is prepared. (C) ′ was introduced into the accommodating portion 3a in the slide coater 3 by a liquid feed pump. An aluminum plate (thickness: 100 μm) was provided as a transparent electrode so as to wind the roller 2, and the roller 2 was rotated so as to run at a constant speed in the direction of arrow D. In the slide coater 3, the gap A between the discharge portion tip 3 c and the transparent electrode 1 in the shortest distance direction between the rotation axis C of the roller 2 and the discharge portion tip 3 c of the slide coater 3 is set to 50 μm. The angle θ formed by the shortest distance direction between the axis C and the discharge portion tip 3c and the horizontal plane was set to 15 °. Further, a cooling water channel 5 was provided in the slide coater 3, and the temperature of the slide coater 3 and the dielectric particle-containing coating solution (c) ′ 4 was maintained at about 16 ° C. by circulating the well water. The slide coater 3 is started, and the dielectric particle-containing coating solution (c) ′ accommodated in the accommodating portion 3a is discharged from the discharge port 3b in a constant amount so that the target film thickness of the dry coating film becomes 20 μm by the liquid feeding pump. did. On the other hand, the moving speed of the transparent electrode 1 traveling in the direction of the arrow D is set to a constant speed of 10 m / min. Further, the transparent electrode 1 moves along the inclination from the discharge port 3b and is continuously applied to the transparent electrode 1 with a width of 2 m for 1000 m. . Next, drying is performed in a drying chamber in which the drying temperature changes stepwise from 40 ° C. to 120 ° C., where the zone from 40 ° C. to 80 ° C. is set to ½ of the total drying time. Thus, a sheet-like laminate having a dielectric layer formed on an aluminum plate was obtained.

A light emitting layer, a transparent electrode layer, and a sealing film were formed on the sheet-like laminate obtained as described above to produce an EL element. The sheet-like laminate is placed again on the coating apparatus on which the above-described slide coater is placed, and the EL phosphor particle-containing coating solution (a) is applied in the same manner as the coating of the dielectric layer so that the coating film has a dry film thickness. The sheet-like laminate was applied and dried at a moving speed of 10 m / min so as to be 20 μm, thereby obtaining a sheet-like laminate in which a dielectric layer and a light emitting layer were laminated on an aluminum plate. On top of that, ITO formed by sputtering on a 100 μm thick polyethylene terephthalate film as a transparent electrode was bonded, and then a sheet-like laminate having a size of 1 m × 1 m was cut out. Thereafter, a lead wire for supplying a voltage to the transparent electrode and the back electrode was attached, and the whole was sealed with a sealing film to obtain an EL element having the configuration of FIG.
That is, as shown in FIG. 13, the obtained EL element includes a transparent electrode 7, a light emitting layer 9a formed over the transparent electrode 7, a dielectric layer 10c formed over the light emitting layer 9a, The back surface electrode 11 is provided so as to overlap the dielectric layer 10c, the fluorescent pigment 8 is dispersed in the light emitting layer 9a, and the distribution of the fluorescent pigment 8 is on the transparent electrode 7 side as shown in FIG. It is expensive. Specifically, it was confirmed that 70% of the added fluorescent pigment was contained in the light emitting layer having a depth of 5 μm from the interface between the light emitting layer and the transparent electrode layer.

Decrease rate (%) of the emission peak value of the fluorescent pigment after the irradiation of the EL element produced in the examples and comparative examples with 100 mW / cm ² ultraviolet ray using a high pressure mercury lamp for 10 hours, and the EL element, Table 1 shows the body colors. As is clear from Table 1, the emission peak values of the fluorescent pigments of the examples remain within a reduction rate of 5% before and after the ultraviolet irradiation, whereas in the comparative examples, a reduction of 15% or more occurs. . It can also be seen that the body color of the EL element is stronger in pink than in the examples.

FIG. 1 is a schematic diagram for explaining a state in which an EL phosphor particle-containing coating solution or a dielectric particle-containing coating solution is applied onto a transparent electrode using a slide coater in the EL device manufacturing method of the present invention. It is explanatory drawing. FIG. 2 is a diagram for explaining a state in which an EL phosphor particle-containing coating solution or a dielectric particle-containing coating solution is applied on a transparent electrode using an extrusion coater in the EL element manufacturing method of the present invention. It is a schematic explanatory drawing. FIG. 3 illustrates a state in which the EL phosphor particle-containing coating liquid or the dielectric particle-containing coating liquid is simultaneously laminated and coated on a transparent electrode using a two-stage slide coater in the EL element manufacturing method of the present invention. It is a schematic explanatory drawing for doing. FIG. 4 is a diagram for explaining a state in which an EL phosphor particle-containing coating solution or a dielectric particle-containing coating solution is applied onto a transparent electrode using an extrusion coater in the EL device manufacturing method of the present invention. It is a schematic explanatory drawing. FIG. 5 is a schematic cross-sectional view of the EL element prepared in Example 1. FIG. 6 is a graph showing the fluorescent pigment distribution in the light emitting layer of the EL device prepared in Example 1. FIG. 7 is a schematic cross-sectional view of an EL element created in Example 2. FIG. 8 is a graph showing the fluorescent pigment distribution in the light emitting layer of the EL device prepared in Example 2. FIG. 9 is a schematic cross-sectional view of an EL element produced in Example 3. FIG. 10 is a graph showing the fluorescent pigment distribution of the dielectric layer of the EL element produced in Example 3. FIG. 11 is a schematic cross-sectional view of an EL element produced in Example 4. FIG. 12 is a graph showing the fluorescent pigment distribution in the light emitting layer of the EL device prepared in Example 4. FIG. 13 is a schematic cross-sectional view of an EL element created in a comparative example. FIG. 14 is a graph showing the fluorescent pigment distribution in the light emitting layer of the EL device prepared in the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent electrode 2 Roller 3 Coater 3a Storage part 3b of EL phosphor particle containing coating liquid (A) or dielectric particle containing coating liquid (A) 'EL phosphor particle containing coating liquid (A) or dielectric particle containing coating liquid (A) Discharge port 3c Discharge portion tip 3d EL phosphor particle-containing coating solution (B) or dielectric fine particle-containing coating solution (B) 'container 3e EL phosphor particle-containing coating solution (B) or dielectric Fine particle-containing coating solution (B) 'discharge port 4 EL phosphor particle-containing coating solution (A) or dielectric fine particle-containing coating solution (A)'
5 Cooling water channel 6 EL phosphor particle-containing coating solution (B) or dielectric fine particle-containing coating solution (B) '
A The gap between the coater discharge port tip and the transparent electrode B The film thickness C The roller rotation axis D The transparent electrode moving speed θ Angle α Angle formed by the coating liquid discharge direction of the extrusion coater and the horizontal plane 7 Transparent electrode layer 8 Fluorescent pigment particle 9a Light emitting layer a
9b Light emitting layer b
9c Light emitting layer c
10a Dielectric layer a
10b Dielectric layer b
10c Dielectric layer c
11 Back electrode layer

Claims (14)

In a dispersive electroluminescent device having at least a transparent electrode, a light emitting layer in which electroluminescent phosphor particles are dispersed, a dielectric layer, and a back electrode in this order,
In the light emitting layer, a fluorescent pigment for converting a part of light emitted from the electroluminescent phosphor particles into another wavelength is dispersed, and the content distribution of the fluorescent pigment is the back surface in the thickness direction of the light emitting layer. A dispersive electroluminescence element characterized by being made higher toward the electrode side.   50% by mass or more of the content of the fluorescent pigment in the light emitting layer is contained in a portion having a film thickness within 30% from the end face on the back electrode side with respect to the film thickness of the light emitting layer. Item 2. A dispersion type electroluminescent device according to Item 1. In a dispersive electroluminescent device having at least a transparent electrode, a light emitting layer in which electroluminescent phosphor particles are dispersed, a dielectric layer, and a back electrode in this order,
The dielectric layer is dispersed with a fluorescent pigment that converts part of the light emitted from the electroluminescent phosphor particles to a different wavelength, and the content distribution of the fluorescent pigment is increased toward the light emitting layer side. A dispersive electroluminescent device characterized by the above.   50% by mass or more of the content of the fluorescent pigment in the dielectric layer is contained within a film thickness of 30% from the end face on the light emitting layer side with respect to the film thickness of the dielectric layer. Item 4. A dispersed electroluminescent device according to Item 3.   The thickness of the said light emitting layer is the range of 0.5 micrometer or more and 30 micrometers or less, The dispersion type electroluminescent element as described in any one of Claims 1-4 characterized by the above-mentioned.   6. The dispersion type electroluminescent device according to claim 1, wherein an average particle size of a sphere equivalent diameter of the electroluminescent phosphor particles is in a range of 0.1 μm to 15 μm. The fluorescent pigment is a pigment having at least a color conversion material represented by the general formula (A) and a matrix resin that supports the color conversion material. The dispersive electroluminescent element according to 1.
In general formula (A), R ¹ , R ² , R ³ , R ⁴ , and R ⁵ each represent a hydrogen atom or a substituent. X represents an oxygen atom, a sulfur atom, or N—R ^Y1 , and R ^Y1 represents a hydrogen atom or a substituent. L represents a linking group comprising a conjugated bond. R ^x and R ^y each represent a hydrogen atom or a substituent, and at least one of them represents an electron withdrawing group. The dispersion type electroluminescent device according to claim 7, wherein the general formula (A) is represented by the general formula (I).
In the formula, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each represent a hydrogen atom or a substituent. X represents an oxygen atom, a sulfur atom, or N—R ^Y1 , and R ^Y1 represents a hydrogen atom or a substituent. L represents a linking group comprising a conjugated bond. Z ¹ represents an atomic group necessary for forming a 5- to 6-membered ring. The dispersion type electroluminescent device according to claim 8, wherein the general formula (A) is represented by the general formula (II).
In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ³¹ , R ³² , R ³³ and R ³⁴ each represent a hydrogen atom or a substituent. X represents an oxygen atom, a sulfur atom, or N—R ^Y1 , and R ^Y1 represents a hydrogen atom or a substituent. Z ² represents an atomic group necessary for forming a 5- to 6-membered ring. L ₂₁ and L ₂₂ may be the same or different from each other, and each represents a methine group, a substituted methine group or a nitrogen atom. n represents an integer of 0 to 3. In the manufacturing method of the dispersion-type electroluminescent element of Claim 1,
An electroluminescent phosphor particle-containing coating in which an electroluminescent phosphor particle, a fluorescent pigment that converts a part of light emitted from the electroluminescent phosphor particle to a different wavelength, a binder, and a solvent that dissolves the binder are mixed and dispersed. Coating liquid adjustment process for adjusting the liquid,
A light emitting layer forming step of forming the light emitting layer by applying the electroluminescent phosphor particle-containing coating solution on the transparent electrode, and the content distribution of the fluorescent pigment on the back electrode side in the thickness direction of the light emitting layer is increased The manufacturing method of the dispersion-type electroluminescent element characterized by including the drying process dried on conditions. In the manufacturing method of the dispersion-type electroluminescent element of Claim 1,
Mixing the electroluminescent phosphor particles, the fluorescent pigment that converts part of the light emitted from the electroluminescent phosphor particles into a different wavelength, the binder, and the solvent that dissolves the binder while changing the amount of fluorescent pigment added. A coating solution adjusting step of dispersing and adjusting two or more types of electroluminescent phosphor particle-containing coating solutions having different addition amounts of fluorescent pigments, and two or more types of electroluminescent phosphor particle-containing coating solutions are simultaneously laminated and applied. And a light emitting layer forming step of forming a light emitting layer in which two or more layers having different fluorescent pigment contents are laminated so that the content of the fluorescent pigment becomes higher toward the back electrode side in the thickness direction of the light emitting layer. A method for producing a dispersive electroluminescent device, comprising: In the manufacturing method of the dispersion-type electroluminescent element of Claim 3,
Prepare a coating solution containing dielectric particles, in which a fluorescent pigment, a binder, and a solvent that dissolves the binder are mixed and dispersed to convert part of the light emitted from the dielectric particles and the electroluminescent phosphor particles to a different wavelength. Coating liquid adjustment process,
A dielectric layer forming step of forming a dielectric layer by applying the coating solution containing the dielectric particles on the back electrode; and
A method for producing a dispersion-type electroluminescent device, comprising a drying step of drying under a condition that the content distribution of the fluorescent pigment on the light emitting layer side in the thickness direction of the dielectric layer is high. In the manufacturing method of the dispersion-type electroluminescent element of Claim 3,
Mix and disperse the fluorescent pigment, binder, and solvent that dissolves the binder, changing part of the light emitted from the dielectric particles and electroluminescent phosphor particles by changing the amount of fluorescent pigment added. A coating liquid adjusting step for adjusting two or more kinds of dielectric particle-containing coating liquids having different addition amounts of fluorescent pigments,
Two layers having different fluorescent pigment contents so that two or more kinds of the above-mentioned dielectric particle-containing coating solutions are laminated and applied at the same time, and the fluorescent pigment content becomes higher toward the light emitting layer side in the thickness direction of the dielectric layer. A method for manufacturing a dispersion-type electroluminescent element, comprising a dielectric layer forming step of forming a dielectric layer formed by laminating the above.   The dispersion according to any one of claims 10 to 13, wherein the electroluminescent phosphor particle-containing coating liquid or the dielectric particle-containing coating liquid is applied using a slide coater or an extrusion coater. Type electroluminescent element manufacturing method.