WO2006025403A1

WO2006025403A1 - Dispersion type electroluminescence element

Info

Publication number: WO2006025403A1
Application number: PCT/JP2005/015790
Authority: WO
Inventors: Tadanobu Sato; Takafumi Noguchi; Koji Kawato
Original assignee: Fujifilm Corporation
Priority date: 2004-08-31
Filing date: 2005-08-30
Publication date: 2006-03-09

Abstract

A white-light-emitting dispersion type EL element excellent in color rendering property (especially, red). A dispersion type electroluminescence element comprising a transparent electrode, a rea-surface electrode, and a light emitting particle layer held between the both electrodes, wherein a curve I(λ) obtained by normalizing spectrum when the element emits light is set to satisfy, in a wavelength region of 410nm through 650nm, g(λ)≤ I(λ)≤ f(λ). [Expression 1] g(λ)=0.9exp(-ln(2)((λ-490)/25))2)+0.25exp(-ln(2)((λ-550)/25))2 )+0.4exp(-ln(2)((λ-610)/20))2 )+0.15exp(-ln(2)(( λ-625)/40))2) f(λ)=1.1exp(-ln(2)((λ-490)/55))2)+0.8exp(-ln(2)((λ-605)/25))2 )+0.5exp(-ln(2)(( λ-640)/40))2)

Description

Dispersive electoluminescence device

Technical field

[0001] The present invention relates to a dispersive electoluminescent device having a light emitting particle layer in which an electroluminescent phosphor powder is dispersedly applied.

Background art

[0002] Electric mouth luminescence (hereinafter also referred to as "EL") phosphors are voltage-excited phosphors, and are used as distributed EL devices in which phosphor powder is sandwiched between electrodes to form a light-emitting device. It is known. The general shape of a dispersion-type EL device is a structure in which phosphor powder is dispersed in a high-dielectric-constant inductor and is sandwiched between two electrodes, at least one of which is transparent. Light is emitted by applying an alternating electric field between the electrodes. An EL device, which is a light emitting device made using phosphor powder, can be made to a thickness of 1 mm or less, and since it does not use a high-temperature process in the manufacturing process, it is a flexible and lightweight device using a plastic substrate. Since it has many advantages such as being capable of being formed, being able to be manufactured at a low cost with a relatively simple process without using a vacuum device, and being a surface light emitter, a backlight such as an LCD, It can be applied to display elements, and can be used as road signs, lighting for various interiors and exteriors, light sources for flat panel displays such as liquid crystal displays, and illumination light sources for large areas.

[0003] Dispersion type EL elements that have been proposed to emit white light have a light emission waveform in which light emission intensity is concentrated mainly in two wavelength regions of blue-green and orange to red. For example, as described in many patents such as Patent Documents 1 to 3, a rhodamine-based compound was placed in a light emitting particle layer to form a white light emitting EL.

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

Patent Document 2: JP-A-60-170194

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

Disclosure of the invention

Problems to be solved by the invention [0004] As described above, these dispersed EL elements that emit white light have various advantages as a flexible planar light source, but are inferior in color rendering properties compared to other white light sources such as fluorescent lamps. There was a big problem. When a transparent medium such as a transparent positive image was placed on an EL element and observed, its color reproducibility was greatly inferior to that under conventional illumination using a fluorescent light or the like as a flat light source. For example, in ELs of Patent Documents 1 to 3, orange light emission derived from rhodamine light emission is used as red light emission, and red light is reproduced even when white light emission is placed on a transparent medium such as a transparent positive image. I couldn't.

[0005] Therefore, an object of the present invention is to obtain a dispersive EL element that emits white light and has excellent color rendering (particularly red).

Means for solving the problem

[0006] The present invention can be realized by the following means.

[0007] (1) A curve obtained by standardizing a spectrum when a device emits light, compared with a dispersive electoluminescence device having a transparent electrode, a back electrode, and a luminescent particle layer sandwiched between the two electrodes. Ι (λ) force Wavelength 410nm or more and 650nm or less,

& (λ) ≤ΐ (λ) ≤ί (λ)

A dispersive electoluminescent element characterized by satisfying

[0008] In the above formula, g (e) and ί (λ) are

[0009] [Equation 1]

[0010] is a curve represented by

[0011] (2) A curve obtained by standardizing a spectrum when a device emits light for a dispersive electoluminescence device having a transparent electrode, a back electrode, and a luminescent particle layer sandwiched between the two electrodes. Ι (λ) force Wavelength 400nm to 700nm

& (λ) ≤ΐ (λ) ≤ί (λ)

A dispersive electoluminescent element characterized by satisfying

[0012] In the above formula, g (e) and ί (λ) are [0013] [Equation 2] g {X) = 0.9exp (-ln (2) (^-^) ² ) + 0.25 _ex p (— ln® ^ ⁵⁰ ) ² ) ₊ 0.4exp (— ln (2) ( ^^) ² ) + 0.15exp (-ln (2) (^^) ² )

[0014] is a curve represented by

[0015] (3) The dispersion-type electroluminescent device according to (1) or (2), wherein, in Ι (λ), a maximum value on a longer wave side than a minimum value is 600 nm or more.

[0016] (4) In Ι (λ), the maximum value on the long wave side from the minimum value is Ι (λ) ≤ 0.95. A dispersive electo-luminescence element as described in 1.

[0017] (5) In an electoluminescence device having a transparent electrode, a back electrode, and a luminescent particle layer sandwiched between the two electrodes, a luminescent particle layer, a light scattering layer, and a wavelength conversion material between the two electrodes The dispersion-type electroluminescent device according to any one of (1) and others (4), comprising a layer and a dielectric layer in this order.

[0018] (6) The dispersion-type electroluminescent device according to (5), wherein the light scattering layer is thinner than the dielectric layer.

[0019] (7) The dispersion type electroluminescent device according to (5) or (6) above, wherein an average size used in the light scattering layer is 0.7 m or less.

[0020] (8) The dispersion-type electroluminescent device according to any one of (5) to (7), wherein the wavelength conversion material layer has a thickness of 3 μm to 20 μm. .

[0021] (9) A method for producing a dispersive electoluminescent element according to any one of (5) to (8).

[0022] (10) In an electoluminescence device having a transparent electrode, a back electrode, and a luminescent particle layer sandwiched between the two electrodes, a luminescent particle layer and a dielectric layer are provided between the two electrodes. The dispersion-type electroluminescent device according to (1) or (2) above, wherein the dielectric layer includes dielectric particles and a wavelength conversion material.

[0023] (11) The content ratio of the wavelength conversion material is 1% by mass or more and 20% by mass or less with respect to the dielectric particles, and the thickness of the dielectric layer is 1 m or more and 25 μm or less. Toss The electroluminescent device according to (10) above.

[0024] (12) The electoluminescence device according to (10), wherein the wavelength conversion material has a maximum emission wavelength of 550 nm to 650 nm.

(13) The maximum wavelength of light emission of the wavelength conversion material is 550 nm or more and 650 nm or less, and the content ratio of the wavelength conversion material is 1% by mass or more and 20% by mass or less with respect to the dielectric particles,

The electret luminescence device according to any one of (10) to (13), wherein the dielectric layer has a thickness of 1 μm to 25 m.

[0026] (14) The electroluminescent device according to any one of (10) to (13), wherein the wavelength converting material is a material in which an organic compound is dispersed in a polymer. The invention's effect

[0027] The EL element of the present invention is particularly excellent in red color rendering than the conventional EL element. In addition, the color rendering property of skin color is greatly improved in the EL device of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0028] The ideal white light-emitting light source emits uniform light intensity at any wavelength in the visible range. In this case, the color rendering properties are the best. However, in the case of dispersive inorganic EL, for example, two large emission bands, namely, electroluminescence (blue-green) of phosphor particles and long-wave emission (orange to red) by a wavelength conversion material that absorbs the light emitted from the phosphor particles. Therefore, how much light is emitted in the vicinity of the wavelength that can best recognize blue, green, and red colors for human vision is a problem. In other words, how much light is emitted in the vicinity of 450 nm, 530 nm, and 610 ηm has a significant effect on the color rendering, and in addition, in the case of EL light emission consisting of these two large light emission bands, color mixing is avoided. In addition, for example, it is necessary to have a wavelength distribution that can clearly separate green and red colors. In other words, taking green and red as an example, if there is little light near the equilibrium point (578nm) of the visual sensitivity of green and red, green and red light can be distinguished and recognized, and better color rendering can be ensured. . When considering compatibility with white light emission, it is important that blue, green, and red light are emitted in a well-balanced manner.

[0029] Considering these, it is very important from the viewpoint of color rendering properties and whiteness to determine the shape of the EL spectrum, and it is necessary to obtain the desired color rendering properties and whiteness. For example, The shape is a shape included in a certain range.

[0030] It is known that the emission spectrum can generally be approximated by a Lorentz type, Gaussian type, or a linear combination type or a point type distribution function thereof. In the present invention, when the EL emission spectra of a number of dispersive ELs were examined, it was found that these spectra were! And that the deviation could be expressed by a linear combination of Gaussian distribution functions. The Gaussian distribution function S (λ) is expressed by the following equation.

G

[0031] [Equation 3]

In the formula, λ represents a measurement wavelength, Α represents a peak height (intensity), u represents a peak wavelength, and w represents a value of 1Z 2 having a half width.

[0033] The EL emission spectrum Ι (λ) of the dispersive EL element is S (

G

λ)) can be expressed as a sum of S (λ), and I (λ) is a linear combination of S (λ). The present invention

G

In, the “normalized” width of the measured spectrum of the EL emission spectrum divided by the maximum value is expressed as I (λ).

[0034] As described above, in many cases, the dispersive EL has two types of luminous power, ie, electroluminescence of phosphor particles and long-wave emission by a wavelength conversion material that absorbs light emitted from the phosphor particles. These emissions give blue-green light and red light. For blue-green light emission, it is ideal to have a light emission band that stimulates human blue and green sights evenly, with a peak at 490 nm and a single Gaussian distribution. It is ideal that the light emission band be expressed by (having an equal energy distribution centered on 490 nm). Even if it emits red light,

It is ideal to have a peak at around 610 nm. For the shape of the emission band, there is a difference in human red visibility and the color expressed as red (light around 650 nm), so there is a single Gaussian distribution. It is better to have a shape that includes a light emission component of a longer wave than the light emission band represented by That is, the red light emission is preferably expressed as a function of the sum of a Gaussian distribution having a peak at a short wave slightly shorter than 6 lOnm and a Gaussian distribution having a peak at a longer wave and a large half-value width. On the other hand, when the blue-green light emission band becomes narrower or the red light emission becomes weaker, the green light becomes weaker and the color rendering of green deteriorates. In this case green In order to supplement the light, it is necessary to cover another emission center represented by another Gaussian distribution in the green emission wavelength region.

[0035] By adding the viewpoint of satisfying white light emission to this concept, the intensity ratio of the blue-green and red light-emitting bands or the blue-green, green and red light-emitting bands can be determined within a certain range. In addition, when the upper and lower limit functions of the spectrum satisfying preferable color rendering properties and whiteness are obtained, the upper limit function f (λ) of the spectrum is

[0036] Painting

/ (l) = le _X p (-l _n (2) (^^) ² ) ₊ 0.8exp (-ln (2) (^^) ² ) + 0.5e _X p (-ln (2X ^^) ² )

[0037] and the lower limit function g (λ) is

[0038] [Equation 5]

[0039] It was found that Therefore, I (λ) obtained by normalizing the spectrum actually measured is in the range of 400 nm to 700 nm which is effective as a spectrum.

& (λ) ≤ΐ (λ) ≤ί (λ)

It is characterized by satisfying. This invention is referred to as the first invention in this specification.

[0040] As described above, in the first invention, Ι (λ) is always 1 (e) or more and g () or more and λ (λ) or less in a section of 400 nm or more and 700 nm or less. On the other hand, g (λ) ≤ΐ (λ) ≤ί (λ) may not be satisfied in the wavelength range where the color rendering properties and whiteness are hardly affected, such as the end of the spectrum. For example, even if the shape is cut by absorption of the sealing film covering the outside of the L element, the color rendering property may not be greatly affected. In other words, g (λ) ≤ ΐ (λ) ≤ ί (λ) is preferably in the range of 400 nm to 700 nm, but it should be at least 410 nm to 650 nm. This latter invention is referred to as the second invention in this specification.

[0041] In order to maintain good color rendering properties of red, it is preferable to satisfy the above. More preferably, in 値 (λ), the maximum value on the long wave side from the minimum value is 600 nm or more, which is derived from the fact that the red emission wavelength of the EL element approaches the human red visibility. [0042] On the other hand, from the viewpoint of maintaining a good white color, it is important to balance the blue-green coloration and the red coloration. In Ι (λ), the maximum value on the longer wave side than the minimum value is It is preferable that Ι (λ) ≤ 0.95.

[0043] The color temperature at the time of light emission of the EL element obtained by the spectrum represented by Ι (λ) is preferably 3500 ° C or more and 85OOK or less, more preferably 5000K or more and 8000K or less. At this time, the preferable values of X and y on the chromaticity coordinates are forces that are each in the range of 0.25 force to 0.45, more preferably both are included in the range of 0.28 to 0.40. It is to be.

[0044] Dispersion EL has the advantage that the spectrum shape can be easily adjusted by mixing a plurality of phosphor particles having different emission colors or using a plurality of wavelength conversion materials. The

[0045] Phosphor particles preferably used in the present invention are particles prepared by various preparation methods such as firing by mixing a base material, an activator, and, if necessary, a coactivator.

[0046] The matrix material used in this case is specifically composed of one or more elements selected from group II elements and group VI elements, and 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, and is arbitrarily selected according to a necessary emission wavelength region. Examples thereof include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, CaS, MgS, SrS, GaP, GaAs, and mixed crystals thereof. ZnS, CdS, CaS, and the like can be preferably used. Furthermore, the base material of the particles includes BaAlS, CaGaS, GaO, ZnSiO, ZnGaO, ZnGaO, ZnGeO, ZnGeO, Zn

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

Al O, CaGa O, CaGeO, Ca Ge O, CaO, Ga O, GeO, SrAl O, SrGa O

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

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

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

SiO, Y GeO, Y Ge O, Y GeO, Y O, Y O S, SnO and their mixed crystals

5 2 5 2 2 7 4 8 2 3 2 2 2

It can be preferably used.

[0047] As the activator, metal ions such as Mn and Cu and rare earth elements can be preferably used.

[0048] Further, as a coactivator added as necessary, halogen elements such as CI, Br, and I, A1 and the like can be preferably used. Furthermore, in the present invention, it is more preferable to use the following phosphor particles.

(a) Phosphor particles whose average particle size (sphere equivalent diameter) force is in the range of 0.1 m or more and 20 μm or less and the particle size variation coefficient force is less than 0%.

(b) Phosphor particles having an average particle size of 0.1 μm or more and 20 m or less and having multiple twin structures inside the particles and having 10 or more layers at intervals of 5 nm or less in one particle .

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

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

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

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

[0050] The phosphor particles usable in the present invention can be formed by a firing method (solid phase method) widely used in the industry. For example, in the case of zinc sulfate, a fine particle powder (usually called raw powder) with a crystallite size in the range of 10 nm to 50 nm is prepared by the liquid phase method, and this is used as a primary particle, which is called an activator. Impurities are mixed, and particles are obtained by first firing in a crucible with a flux at a high temperature in the range of 900 ° C to 1300 ° C for 30 minutes to 10 hours. The intermediate phosphor powder obtained by the first firing is repeatedly washed with ion exchange water to remove alkali metal, alkaline earth metal, excess activator, and coactivator. Next, second baking is performed on the obtained intermediate phosphor powder. In the second baking, heating (annealing) is performed at a temperature lower than that of the first baking in the range of 500 ° C. to 800 ° C. and in a short time of 30 minutes to 3 hours. These firings cause many stacking faults in the phosphor particles, but the conditions of the first firing and the second firing are appropriately set so that fine particles and more stacking faults are included in the phosphor particles. It is preferable to select. In addition, by applying an impact force in a certain range to the intermediate phosphor powder, the density of stacking faults without breaking the particles can be greatly increased. As a method of applying impact force, a method of contacting and mixing particles of the intermediate phosphor powder, a sphere such as alumina, etc. A method of mixing and mixing (ball mill), a method of accelerating and colliding particles, a method of irradiating ultrasonic waves, and the like can be preferably used. Thereafter, etching is performed with an acid such as HC1 to remove metal oxides adhering to the surface, and copper sulfide adhering to the surface is removed by washing with KCN and dried to obtain phosphor particles.

[0051] In addition, as a method for forming phosphor particles usable in the present invention, it is preferable to use a hydrothermal synthesis method, a urea melting method, or a spray pyrolysis method. Further, a laser 'ablation method, a CVD method is used. Gas phase methods such as methods combining plasma, chemical vapor deposition, sputtering, resistance heating, electron beam method, fluid oil surface deposition, metathesis method, precursor thermal decomposition method, reverse micelle method It can also be formed by using a method combining calcination with high temperature and a liquid phase method such as freeze-drying.

[0052] The luminescent particle layer can be formed by applying a coating solution containing EL phosphor particles. The EL phosphor particle-containing coating solution is a coating solution containing at least EL phosphor particles, a binder, and a solvent that dissolves the binder. Examples of binders include polymers having a relatively high dielectric constant such as cyanoethyl cellulose resin, polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy resin, and vinylidene fluoride. It is preferable to use fat. To these binders, fine particles with high dielectric constant such as BaTiO and SrTiO

3 3

The dielectric constant can be adjusted by mixing 5 to 50 parts by mass with respect to 100 parts by mass of the binder. As a dispersion method, a homogenizer, a planetary kneader, a roll kneader, an ultrasonic disperser, or the like can be used. As the solvent, any solvent having a high polarity can be used without limitation, and alcohols, ketones, esters, polyhydric alcohols and derivatives thereof, plasticizers, and the like can be preferably used.

[0053] The viscosity of the coating solution containing EL phosphor particles at room temperature is preferably in the range of 0.1 lPa's or more and 10. OPa's or less. 0.3 or more Pa's or more 8. The range of OPa's or less More preferable 1. OPa-s or more 6. OPa's or less is particularly preferable. If the viscosity of the coating solution containing EL phosphor particles is within the above-mentioned range, coating film thickness unevenness hardly occurs, and phosphor particles do not separate and settle with the passage of time after dispersion. It is also possible to apply with the above method. The viscosity is a value measured at 20 ° C. which is the same as the coating temperature.

[0054] The luminescent particle layer is made of a transparent material such as a slide coater or an etrusion coater. It is preferable to apply continuously on a plastic support or the like provided with a bright electrode so that the dry film thickness of the coating film is in the range of 0.5 m or more and 6 O / zm or less. At this time, the film thickness variation of the luminescent particle layer is preferably 12.5% or less, particularly preferably 5% or less.

[0055] The filling rate of the phosphor particles in the luminescent particle layer is not limited !, but is preferably in the range of 60% by mass to 95% by mass, more preferably in the range of 75% by mass to 85% by mass. It is. In one embodiment of the present invention, by making the particle size of the phosphor particles 20 μm or less, the uniformity of the coating film thickness of the luminescent particle layer is improved, and the smoothness of the coating film surface is simultaneously achieved. improves. Furthermore, when the number of particles per unit area is greatly increased, fine light emission unevenness can be remarkably improved. Furthermore, the decrease in the particle size leads to an increase in the applied voltage of the phosphor particles, and in addition to an increase in the electric field strength to the luminescent particle layer due to the thinner luminescent particle layer, it is favorable for improving the luminance of the EL element. It is also preferable for suppressing vibrations that cause noise.

[0056] Examples of the wavelength conversion material preferably used in the present invention include fluorescent pigments and fluorescent dyes. Among these compounds that form these luminescent centers, compounds having rhodamine, latathone, xanthene, quinoline, benzothiazole, triethylindoline, perylene, triphennin, and dicyanomethylene as skeletons are preferred, as well as cyanine dyes. It is also preferable to use an azo dye, a poly-ethylene bi-ylene polymer, a disilane oligo-chelen polymer, a ruthenium complex, a europium complex, or an erbium complex. These compounds may be used alone or in combination. Further, these compounds may be used as a wavelength conversion material after further being dispersed in a polymer or the like. Among these compounds, those having the maximum value of the emission spectrum in the range of 550 ηm to 650 nm are preferred, more preferably those having the emission maximum in the range of 600 nm to 650 nm, particularly preferably 61 Onm force and 630 nm. It has a light emission maximum in the range.

[0057] The EL device of the present invention preferably has a layer containing these wavelength conversion materials. These wavelength conversion materials can be contained in the luminescent particle layer and the Z or dielectric layer, and are preferably contained in the dielectric layer. In addition, the EL element of the present invention may have a wavelength conversion material-containing layer containing a plurality of dielectric layers and containing a wavelength conversion material at a position sandwiched between the two dielectric layers. Furthermore, these wavelength conversion material-containing layers are not provided between the transparent electrode and the back electrode, and as a wavelength conversion film layer on the outside of the transparent electrode and the back electrode. It is also preferable to have it. The wavelength conversion material-containing layer may be provided around the luminescent particle layer, between the luminescent particle layer and the transparent electrode, or between the luminescent particle layer and the dielectric layer. It is also possible to install in the position.

[0058] As described above, it is preferable that the wavelength conversion material is contained in the dielectric layer, or that the wavelength conversion material layer is disposed at a position sandwiched between the two dielectric layers.

[0059] Since the wavelength converting material is a material that absorbs light emitted from the phosphor particles contained in the light emitting particle layer and emits light having a longer wavelength than the light emitted from the phosphor particles, the wavelength converting material is used at these positions. It is preferable. That is, when the material performs wavelength conversion, if there is an overlap in wavelength between the emission band of the wavelength conversion material and the absorption band of the material, the light itself will be absorbed, Apparently, the shape on the short wave side of the emission band changes, and it is observed that no light is emitted. By utilizing this phenomenon, the position of the light emission maximum of the material can be changed by changing the way light is applied to the material without changing the wavelength conversion material, and by changing the amount of light absorption of the material. The emission maximum wavelength (red emission maximum wavelength) of the wavelength conversion material can be adjusted to a desired wavelength.

[0060] In the present invention, an EL device having a light emitting particle layer, a light scattering layer, a wavelength conversion material layer, and a dielectric layer in this order between a transparent electrode and a back electrode is more preferable. More preferably, an EL element having a luminescent particle layer, a light scattering layer, a wavelength conversion material layer, and a dielectric layer in this order from the transparent electrode side between the transparent electrode and the back electrode is used. The light scattering layer can be formed of the same material as the dielectric layer, and is preferably provided as a thin dielectric layer under the light emitting particle layer.

[0061] With the above element configuration, the light scattering function by the light scattering layer located on the light emitting particle layer side from the wavelength conversion material layer, and the lower side of the wavelength conversion material layer (that is, the back electrode side, the wavelength conversion material). The light scattering state around the wavelength conversion material layer can be controlled by the light reflecting function of the dielectric layer located on the opposite side of the light scattering layer across the layer. That is, between the light scattering layer and the dielectric layer, the light incident from the light emitting particle layer is subjected to multiple reflection Z multiple scattering, and this light is absorbed by a wavelength conversion material such as a pigment in the wavelength conversion material layer, thereby The emission wavelength can be controlled by increasing the self-absorption of the material, controlling the degree of the increase, and adjusting the red emission maximum wavelength to a desired wavelength. Furthermore, the light scattering layer The light incident from the light emitting particle layer is subjected to multiple reflection Z multiple scattering between the light emitting layer and the dielectric layer, and the light emitted from the light emitting particle layer is emitted from the light emitting particle layer by the light. Can be kept to a minimum by absorption of

It is possible to make the L element have high luminance.

[0062] Preferably, the thickness of the light scattering layer is thinner than the thickness of the dielectric layer. The thickness of the light scattering layer is preferably 1 μm or more and 10 μm or less.

[0063] It is preferable that the light scattering layer contains particles capable of obtaining white reflection with a high visible light reflectance. Such materials are selected from sulfates, metal oxides, nitrides, for example MgS

O, BaSO, TiO, BaTiO, SrTiO, PbTiO, KNbO, PbNbO, Ta Ο, BaTa

4 4 2 3 3 3 3 3 2 3 2

Ο, LiTaO, Υ Ο, Α1Ο, ZrO, ΑΙΟΝ, ZnS and the like. Among these

6 3 2 3 2 3 2

The particles used in the light scattering layer are preferably dielectrics.

[0064] Examples of the dielectric particles used in the light scattering layer include dielectric particles used in the dielectric layer described later. When the light scattering layer is a dielectric, the light scattering layer can be formed in the same manner as the dielectric layer.

[0065] The average size of the particles used in the light-scattering layer is an average particle size, preferably not more than 0. m, more preferably not less than 0.01 μm but not more than 0.5 μm, most preferably not more than 0 μm. .05 μm or more and 0.5 m or less. From the viewpoint of reducing the thickness of the light scattering layer, it is also preferable to use a mixture of dielectric particles having different particle sizes. For example, the average particle size is an average particle size of 0 .: m or more and 0.5 m or less. When using particles (also referred to as large size particles), particles having an average particle size of 0.01 μm or more and less than 0.1 μm (also referred to as small size particles) may be mixed. preferable. The average particle size is measured with HORIBALA-920, and is measured when the light transmittance of the measurement sample is 94.5% to 95.4%.

[0066] By setting the thickness of the light scattering layer in the above range, and setting the average size of the dielectric particles used in the light scattering layer in the above range, the wavelength at which incident light is received from the light emitting particle layer. Light emitted from the pigment or the like in the conversion material layer passes through the light scattering layer and is suitably emitted outside the EL element.

[0067] The thickness of the wavelength conversion material layer is preferably 3 m or more and 20 m or less. More preferably, it is 3 μm or more and 15 m or less. The concentration of the material in the wavelength conversion material layer is possible As high as possible is preferable. In other words, it is particularly preferable that the wavelength conversion material layer also has a force only for the wavelength conversion material. “Substantially” means that the concentration of the wavelength converting material in the wavelength converting material layer is 50 mass% to 100 mass%. By setting the thickness of the wavelength conversion material layer in the above range and increasing the concentration, self-absorption of the wavelength conversion material can be increased, which is a preferred embodiment. In the step of forming the wavelength conversion material layer, it is preferable to form the material layer without using a binder. It is preferable that the wavelength converting material is contained in the coating solution and applied. As a dispersion solvent for the wavelength conversion material contained in the coating solution, when a pigment is used for the wavelength conversion material, the pigment used does not dissolve, or the solvent penetrates into the pigment and the fluorescence in the pigment penetrates. It is preferable to use a solvent so that the substance does not elute. Although it depends on the pigment, specific examples include hydrocarbons such as hexane and toluene, alcohols having 3 or more carbon atoms in the main chain such as cyclohexanol and 2-ethylhexanol, glycerin, and ethylene glycol. It is preferable to use a solvent selected from plasticizers such as polyhydric alcohols, halogenated hydrocarbons such as carbon tetrachloride, dioctyl adipate, and dioctyl sebacate. When a binder is used for the wavelength conversion material layer, it is possible to preferably use a binder used when forming the above-described light emitting particle layer or a dielectric layer described later.

[0068] In the present invention, it is also preferable to include a wavelength conversion material in the dielectric layer. More preferably, an EL element having a light emitting particle layer and a dielectric layer containing a wavelength conversion material in this order between a transparent electrode and a back electrode is used. More preferably, the EL element has a light emitting particle layer and a dielectric layer containing a wavelength conversion material in this order from the transparent electrode side between the transparent electrode and the back electrode. As in the case of providing the light scattering layer described above, a wavelength conversion material is placed in a portion where the light scattering is large, and the apparent maximum wavelength of the wavelength conversion material is lengthened by the effect of multiple reflection Z multiple scattering. Is intended.

[0069] When the wavelength converting material and the dielectric particles are mixed, the dielectric particles may be formed using any material as long as the dielectric material has a high dielectric constant and a high reflectance. I can do it. Such materials are selected from metal oxides and nitrides, for example TiO, BaTiO

twenty three

, SrTiO, PbTiO, KNbO, PbNbO, TaO, BaTaO, LiTaO, YO, AlO

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

, ZrO, AION, ZnS and the like can be preferably used. [0070] When the wavelength conversion material and the dielectric particles are mixed, it is preferable to disperse the wavelength conversion material and the dielectric particles in a binder. Examples of binders include polymers having a relatively high dielectric constant such as cyanoethyl cellulose resin, polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy resin, vinylidene fluoride, and the like. Fat is preferred. As a dispersion method of the dielectric material, it is preferable to disperse using a homogenizer, a planetary kneader, a roll kneader, an ultrasonic disperser, or the like.

[0071] When the wavelength conversion material and dielectric particles are mixed, the dielectric layer that also serves as the wavelength conversion material layer is preferably 1 m force to 25 μm, more preferably 5 μm force to 20 μm. The range of. The preferred concentration of the wavelength conversion material when the dielectric particles are mixed with the wavelength conversion material is 1% by mass to 20% by mass, more preferably 2% by mass to 10% by mass with respect to the dielectric particles. .

An embodiment in which all the dielectric layers contained in the EL element also serve as the wavelength conversion material layer is preferable.

More preferably, there are two dielectric layers contained in the EL element, one layer being a dielectric layer containing a wavelength converting material and the other layer being a dielectric layer not containing a wavelength converting material. The In the latter embodiment, either layer may be placed on the back electrode side. Preferably, the dielectric layer containing the wavelength conversion material is on the luminescent particle layer side, and the dielectric layer not containing the wavelength conversion material is on the back electrode side. It is to install in each.

[0073] Further, when the apparent maximum wavelength of the wavelength conversion material is increased by self-absorption as described above, the layer thickness of the layer containing the wavelength conversion material is made as thin as possible, and the wavelength in the layer is reduced. Increasing the concentration of the conversion material is also a preferable means.

[0074] As a preferred example, there is an embodiment in which a wavelength conversion material is not added between the transparent electrode and the back electrode, and the wavelength conversion film layer is used outside the transparent electrode and the back electrode. More preferably, the thickness of the conversion film layer is 0.5 μm or more and 20 μm or less, and the concentration of the wavelength conversion material in the layer is preferably 30% by mass to 100% by mass. μm or more and 15 μm or less, and material concentration is 40% or more and 100% or less by mass. This layer can be formed using a binder. As the noinder, any binder having a high light transmittance can be used. It is also preferable to use a binder used in the luminescent particle layer or dielectric layer in the present invention. High dielectric constant, no need to use polymer, It is also preferable to use olefin resin, such as acrylic resin.

[0075] As another embodiment, phosphor particles that emit red light that is not as strong as the wavelength conversion material can be used as the red light-emitting material. As the phosphor that emits red light, calcium sulfide, strontium sulfide, or a phosphor in which europium or the like is activated using a mixed crystal thereof as a base is preferably used. These red light emitting materials are preferably contained in a light emitting particle layer that emits blue-green light, placed between the light emitting particle layer and the transparent electrode, or between the light emitting particle layer and the dielectric layer. When formed as a layer different from the light emitting particle layer, it can be formed in the same manner as the light emitting particle layer.

[0076] The dielectric layer preferably includes dielectric particles.

[0077] In the present invention, the dielectric particles suitably used for the dielectric layer and the light scattering layer are dielectric materials having a high dielectric breakdown voltage and a high dielectric breakdown voltage with high dielectric constant and insulation properties. Any dielectric material can be used as long as it has a constant rate. Such materials are selected from metal oxides and nitrides, such as TiO, BaTiO, SrTiO, Pb

2 3 3

TiO, KNbO, PbNbO, TaO, BaTaO, LiTaO, YO, AlO, ZrO, AION

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

, ZnS and the like. The average size of the particles used in these dielectric layers is preferably an average particle size of ί to 2.0 μm or less, more preferably ί to 0.01 μm to 1.0 μm, most preferably 0. .05 111 or more and 0.5 / zm or less. These dielectric materials are preferably dispersed in the binder. Examples of binders include polymers with relatively high dielectric constants such as cyanoethyl cellulose resin, polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy resin, and vinylidene fluoride. A cocoa is preferred. As a dispersion method of the dielectric material, it is preferable to disperse using a homogenizer, a planetary kneader, a roll kneader, an ultrasonic disperser, or the like.

The dielectric layer is preferably set as a uniform film or a film having a particle structure. A combination thereof may also be used. “The film is uniform” means that the dielectric layer itself is an amorphous layer or a layer having a crystal structure, and examples of the uniform film include a thin film crystal layer. As a method for providing the dielectric layer as a uniform film, a vapor phase method such as sputtering or vacuum deposition is preferably exemplified. In the case of a uniform film, the thickness of the dielectric layer is preferably in the range of 0.1 μm to 10 μm. [0079] The EL device of the present invention may have one or more dielectric layers. The dielectric layer may be provided on one side of the luminescent particle layer or on both sides of the luminescent particle layer. When provided on both sides of the light emitting particle layer, the dielectric layer on the transparent electrode side may be a film having a particle structure or a dielectric layer consisting only of a high dielectric constant binder. When the dielectric layer is formed by coating, it is preferable to use a slide coater or an etatrusion coater as in the case of the luminescent particle 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.

[0080] The dielectric layer is preferably formed by applying a coating solution containing dielectric particles.

The dielectric particle-containing coating solution is a coating solution containing at least dielectric particles, a binder, and a solvent that dissolves the binder. Here, the binder and the solvent are the same as those used for the light emitting particle layer.

[0081] The viscosity of the coating solution containing dielectric particles at normal temperature is preferably in the range of 0. OlPa's to lOPa's, more preferably in the range of 0.08 Pa's to 8. OPa's. Particularly preferably, it is in the range of 1. OPa's to 6. OPa's. If the viscosity of the coating solution containing dielectric particles is within the above range, the coating film thickness unevenness is difficult to occur, and the dielectric particles do not separate and settle with the passage of time after dispersion. Application is also possible and preferable. The viscosity is a value measured at 20 ° C. which is the same as the coating temperature.

[0082] As the transparent electrode used in the EL device of the present invention, an electrode formed using any commonly used transparent electrode material is used. Examples of transparent electrode materials include tin oxides such as tin-doped oxide tin, antimony-doped tin oxide, and zinc-doped oxide oxide tin, a multilayer structure in which a silver thin film is sandwiched between high refractive index layers, and poly-phosphorus. And π-conjugated polymers such as polypyrrole. For the transparent electrode, it is also preferable to arrange a metal wire such as a comb or grid to improve the conductivity.

[0083] The specific resistivity of the transparent electrode is preferably in the range of 0.01 Ω to 30 Ω.

[0084] The back electrode is the side from which light is not extracted, and any conductive material can be used.

For example, it can be selected from metal such as gold, silver, platinum, copper, iron, and aluminum, graphite, etc. according to the form of the element to be created, the temperature of the creation process, etc. Conductivity If possible, you can use transparent electrodes such as ITO.

[0085] In addition, for both the transparent electrode and the back electrode, a conductive material-containing coating solution in which the conductive fine particle material is dispersed together with a binder is prepared and applied using a slide coater or an etatrusion coater. You can also

[0086] In addition, in the element configuration of the present invention, various protective layers and the like can be applied as necessary.

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

[0088] Each functional layer coated on the support is preferably formed as a continuous process including at least a coating step and a drying step. The drying process is divided into a constant rate drying process until the coating film is dried and solidified, and a decreasing rate drying process for reducing the residual solvent of the coating film. In the present invention, since the binder ratio of each functional layer is high, when rapidly dried, only the surface is dried, convection is generated in the coating film, so-called Benard cell is likely to occur, and pre-expansion due to rapid solvent expansion. Star failure is likely to occur, and the uniformity of the coating is significantly impaired. On the other hand, if the final drying temperature is low, the solvent remains in each functional layer, affecting the subsequent process of EL device fabrication such as the lamination process of moisture-proof film. Therefore, it is preferable that the drying process is performed slowly at a constant rate, and is performed at a temperature sufficient for the solvent to dry. As a method for carrying out the constant rate drying process gently, it is preferable to divide the drying chamber where the support travels into several zones and gradually increase the drying temperature after completion of the coating process.

[0089] In the manufacture of the EL device of the present invention, the light emitting particle layer may be subjected to a force render process using a calendar processor. The smoothness of both main surfaces of the luminescent particle layer formed by calendering is preferably in the range of 0.5 m or less, more preferably 0.2 m or less. The calendar processor to be used is not particularly limited, and can be appropriately selected from among the known devices. A pair of rolls, at least one of which is heated to, for example, 50 ° C to 200 ° C In the meantime, a smoothing process is performed by passing a luminescent particle layer in which phosphor particles are dispersed in a binder while applying pressure as an object. In the calendering process, the heating temperature of the calender roll is preferably higher than the softening temperature of the binder contained in the light emitting particle layer. In addition, the calendar pressure and the conveying speed are not necessary to destroy the phosphor particles or extend the luminescent particle layer more than necessary. It is preferable to select appropriately so that the degree can be obtained.

[0090] The conductive material described above can also be used when providing a compensation electrode to suppress vibration of the EL element. For example, when a compensation electrode is provided outside the transparent electrode from which light is extracted, an oxide such as tin-doped tin oxide, antimony-doped tin oxide, or zinc-doped ichtin tin, or a silver thin film is formed with a high refractive index layer. It is preferable to use transparent electrode materials such as sandwiched multilayer structures, π-conjugated polymers such as polyaline and polypyrrole.

[0091] When the compensation electrode is provided outside the back electrode without extracting light, any conductive material such as metal such as gold, silver, platinum, copper, iron, and aluminum, or graphite is used. Although it can be used, a transparent electrode such as a bag may be used as long as it has conductivity. The compensation electrode is attached to the transparent electrode and the back electrode through an insulating layer. The insulating layer material is an insulating inorganic material or polymer material, a dispersion liquid in which inorganic material powder is dispersed in a polymer material, or the like. Can be formed by vapor deposition or coating. In addition, a conductive material-containing coating solution in which the conductive fine particle material is dispersed together with a binder can be prepared and applied using a slide coater or an etatrusion coater. Furthermore, an insulating material-containing coating solution in which the insulating material is dispersed together with a binder can be prepared and applied simultaneously with the conductive material-containing coating solution. A voltage is applied to the compensation electrode provided from the driving power source, and at this time, the vibration generated in the luminescent particle layer can be canceled by setting the phase opposite to that of the voltage applied to the luminescent particle layer. The compensation electrode has the same effect even if it is attached to either the outer side of the transparent electrode or the outer side of the back electrode with an insulating layer sandwiched between them. It is preferable because it is possible. It is also possible to adjust so that the dielectric constant of the light emitting particle layer (the light emitting particle layer and the dielectric layer, if a dielectric layer is provided) and the dielectric constant of the insulating layer inside the compensation electrode are substantially equal. This is preferable for effective suppression.

[0092] As another method for suppressing vibration of the EL element, a buffer layer used for the EL element is 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 as the buffer material layer. Examples of the polymer material having high impact absorbing ability include natural rubber, styrene butadiene rubber, polyisoprene rubber, polybutadiene rubber, nitrile rubber, chloroprene rubber, butyl rubber, hibaron, silicon rubber, urethane rubber, ethylene propylene rubber, and fluorine rubber. Etc. can be used. The hardness of these polymer materials is preferably 50 or less, more preferably 30 or less, from the viewpoint of vibration absorption ability. In addition, butyl rubber, silicon rubber, fluororubber, and the like are more preferable because they have a low water absorption and function as a protective film for protecting the EL element from moisture. It is also preferable to use as a buffer material a material obtained by adding a foaming agent to the above rubber material, polypropylene, polystyrene, or polyethylene resin. The buffer material layer using these buffer materials can be attached by adhering the buffer material layer to the EL element with an adhesive, but the buffer material is dissolved in a solvent to prepare a buffer material-containing coating solution, It can also be applied using a slide coater or an etrusion coater. Although the thickness of the buffer layer depends on the hardness of the polymer material, it needs to be 20 μm or more and preferably 50 μm or more in order to sufficiently absorb vibration. If it exceeds 200 μm, the thickness of the element increases greatly, which is not preferable in terms of mass and flexibility. Further, the combined use of the compensation electrode and the buffer layer is preferable because it can further suppress vibration.

[0093] 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 the fill arm for sealing the EL element, and more preferably not more than 40 ° C-water vapor permeability at 90% RH is preferably is 0. 05gZm ² Zday following instrument 0. 01gZm ² Zday. Further oxygen permeability at 40 ° C- 90% RH 0. Lcm 3 Zm 2 ZdayZatm is preferably less instrument 0. 01cm ³ Zm ² ZdayZatm less and more favorable preferable. As such a sealing film, a laminated film of an organic film and an inorganic film is preferably used.

[0094] As the material for forming the organic film, polyethylene-based resin, polypropylene-based resin, polycarbonate-based resin, polyvinyl alcohol-based resin, and the like are preferably used, and particularly, polyvinyl alcohol-based resin is more preferably used. be able to. Since polyvinyl alcohol resins and the like have water absorption properties, it is more preferable to use those that have been completely dried by intensive treatment such as vacuum heating. A sheet form by applying such resin. An inorganic film is deposited on the processed material by vapor deposition, sputtering, CVD method or the like. As the inorganic film to be deposited, silicon oxide, silicon nitride, silicon oxynitride, acid silicate, zinc oxyaluminum, aluminum nitride or the like is preferably used. In order to obtain a lower water vapor transmission rate and oxygen transmission rate, and to prevent the inorganic film from cracking due to bending, etc., the formation of the organic film and the inorganic film is repeated, or the organic film deposited with the inorganic film is used as the adhesive layer. It is preferable to laminate a plurality of films through a multi-layer film. The thickness of the organic material film is preferably in the range of 5 m to 300 m, more preferably in the range of 10 m to 200 m. The thickness of the inorganic film is preferably in the range of lOnm or more and 300 nm or less, and more preferably in the range of 20 nm or more and 200 nm or less. The film thickness of the laminated sealing film is preferably in the range of 30 m to 1000 m, more preferably in the range of 50 μm to 300 μm. For example, in order to obtain a sealing film with a water vapor transmission rate of 0.05 g / m ² / day or less at 40 ° C—90% RH, two layers of the above organic film and inorganic film are laminated. With the construction as described above, a force of 50 ~: L00 μm is sufficient. Polyethylene trifluoride chilled titanium used as a sealing film conventionally requires a film thickness of 200 m or more. The thinner the sealing film, the better in terms of light transmission and device flexibility.

[0095] When an EL cell is sealed with this sealing film, even if the EL cell is sandwiched between two sealing films and the periphery is adhesively sealed, the sealing film is folded in half and sealed. The part where the films overlap may be adhesively sealed. For the EL cell sealed with the sealing film, only the EL cell may be prepared separately, or the EL cell may be directly formed on the sealing film. In this case, the support can be used instead. The sealing step is preferably performed in a dry atmosphere with vacuum or dew point control.

[0096] Even when an advanced sealing process is performed, it is preferable to dispose a desiccant layer around the EL cell. As the desiccant used in the desiccant layer, alkaline earth metal oxides such as CaO, SrO, BaO, acid aluminum, zeolite, activated carbon, silica gel, paper and highly hygroscopic resin are preferably used. In particular, alkaline earth metal oxides are more preferable in terms of moisture absorption performance. These hygroscopic agents can be used even in powder form. For example, the hygroscopic agent can be used by mixing it with a resin material and processing it into a sheet by coating or molding. It is preferable to dispose a desiccant layer by applying a coating liquid mixed with a fat material around the EL element using a dispenser or the like. Furthermore, it is more preferable to cover not only the periphery of the EL cell but also the lower and upper surfaces of the EL cell with a desiccant. In this case, it is preferable to select a highly transparent desiccant layer for the light extraction surface. As the highly transparent desiccant layer, polyamide-based resin can be used.

Brief Description of Drawings

FIG. 1 is a schematic view of one embodiment of an EL device of the present invention.

[Fig. 2] A diagram showing the relationship between the emission spectrum (A. U. stands for normalized intensity) of each EL element of the normalized comparative example and f (e) and g (λ).

FIG. 3 is a diagram showing the relationship between the emission spectrum (A. U. stands for normalized intensity) of each EL element of the present invention normalized, and f (e) and g (λ).

Explanation of symbols

[0098] 1 Plastic film (support)

2 Transparent electrode layer

3 Luminescent particle layer

4 Wavelength conversion material layer

5 Dielectric layer

6 Back electrode layer

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

Example 1

[0100] "Creation of EL device using conventional technology" (Comparative Example 1)

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

Three

The aluminum sheet coated with a dielectric layer is coated on a 75 μm thick aluminum sheet so that the layer thickness is 30 μm and dried at 110 ° C. for 5 hours. Obtained.

[0101] Subsequently, zinc sulfide particles having an emission maximum at 498 nm activated with copper and chlorine having an average particle size of 15 μm and a 30 mass% cyanoethylcellulose solution were mixed at a ratio of 1.2: 1. Mixed with ' Disperse, and add 3% by weight of Sinloihi's red pigment (Sinloihi FA-001) to zinc oxide particles and disperse. Then, the thickness of the luminescent particle layer is on the aluminum sheet coated with the dielectric layer. It was applied to 45 m. This coating was dried at 110 ° C for 5 hours using a hot air dryer. This coated product is thermocompression-bonded with a film of 100 μm thick polyethylene terephthalate with a spider sprinkled uniformly to a thickness of 40 nm using a sputter, and a lead piece is placed and sealed with a moisture-proof film. The EL element of Example 1 was used.

“Creation of EL device by conventional technology” (Comparative Example 2)

An EL device of Comparative Example 2 was obtained in the same manner as Comparative Example 1 except that the red light-emitting pigment was Sinloich FA-007.

“Preparation of EL device according to the present invention (1)” (Example 1)

Only 30% by weight Cyanethyl cell with BaTiO fine particles with an average particle size of 0.2 μm

Three

It was dispersed in a rosin solution and coated on a 75 μm thick aluminum sheet so that the layer thickness was 20 μm and dried to obtain an aluminum sheet with a dielectric layer. Subsequently, the average after the particle size obtained by dispersing fine particles of BaTiO of 0. 2 / zm to 30 weight ^_0/0 Xia Bruno cellulose solution, this

Three

A red pigment (Sinloihi FA-007) manufactured by Sinloihi to 8% of the BaTiO mass

Three

It was added and dispersed as described above, and applied to the aforementioned aluminum sheet with a dielectric layer so that the final thickness was 10 m, and dried again at 110 ° C. for 5 hours to form a wavelength conversion material layer. In addition, the average particle size Xia Bruno ethylcellulose solution硫I匕zinc particles and 30 mass ^_0/0 with an emission maximum copper and chlorine 15 m to 498nm was activated 1.2: 1 ratio ' After the dispersion, it was applied to an aluminum sheet having a wavelength conversion material layer so that the thickness of the luminescent particle layer was 45 m and dried at 110 ° C. for 5 hours using a hot air dryer. This coated material was thermocompression bonded to a film having a uniform thickness of 40 nm deposited on a polyethylene terephthalate having a thickness of 100 μm by sputtering. Finally, a lead piece was placed and sealed with a moisture-proof film between them to obtain an EL element (1) according to the present invention. (refer graph1)

“Creation of EL device according to the present invention (2)” (Example 2)

In the method for producing an EL device (1) according to the present invention, 40% by mass of the zinc sulfide particles in the luminescent particle layer are particles having an emission maximum at 450 nm, and the remaining 60% by mass are particles having an emission maximum at 498 nm. In addition, the amount of red light emitting pigment added to the wavelength conversion material layer is 10% by mass. Except for the above, an EL device (2) according to the present invention was obtained in the same manner as the method for producing an EL device (1) according to the present invention.

“Creation of EL device according to the present invention (3)” (Example 3)

Three

Add a red pigment that emits light at 620 nm to the dispersion liquid of 6% so that the mass of BaTiO is 6%.

Three

Then, it was applied to the above-mentioned aluminum sheet with a dielectric layer so that the resulting thickness would be 10 m and dried again at 110 ° C. for 5 hours to form a wavelength conversion material layer. Furthermore, zinc sulfide particles having an emission maximum at 498 nm activated with copper and chlorine with an average particle size of 15 m and 30% by mass of cyanocellulose solution were mixed and dispersed at a ratio of 1.2: 1. After that, the aluminum sheet on which the wavelength converting material layer was formed was applied so that the thickness of the luminescent particle layer was 45 μm and dried at 110 ° C. for 5 hours using a hot air dryer. This coated material was thermocompression bonded with a film in which ITO was uniformly deposited to a thickness of 40 nm on a 100 m thick polyethylene terephthalate by sputtering. Finally, a lead piece was placed and sealed with a moisture-proof film between them to make an EL element (3) according to the present invention.

“Production of EL device according to the present invention (4)” (Example 4)

The Xia Bruno ethylcellulose solution硫I匕亜lead particles and 30 mass ^_0/0 having an emission maximum at 498nm with an average particle size was activated with copper and chlorine 15 m 1. 2: mixture 'was dispersed in 1 ratio Thereafter, ITO was applied onto polyethylene terephthalate having a thickness of 100 μm by sputtering so that the luminous particle layer had a thickness of 45 m on a film having a uniform thickness of 40 nm. The coated material was dried at 110 ° C. for 5 hours using a hot air dryer, and then a solution in which BaTiO fine particles having an average particle size of 0.2 μm were dispersed in a 30 mass% cyanoethyl cellulose solution was prepared.

Three

This layer was applied to a thickness of 3 m and dried at 110 ° C. for 5 hours to form a light scattering layer. A solution in which 30% by mass of the red light-emitting pigment used in the EL device (3) according to the present invention was dispersed in cyclohexanol was applied onto the dried product and dried at 110 ° C. for 2 hours to obtain a wavelength conversion material. A layer was formed. The coated product thus obtained has an average particle size of 0.2. dispersed μ particles 30 mass ^_0/0 Xia Bruno ethylcellulose solution of BaTiO 3 m, the induction

Three

It was thermocompression bonded to a sheet coated on a 75 μm thick aluminum sheet so that the thickness of the electrical layer was 25 μm. An EL element (4) according to the present invention was obtained by mounting a lead piece on the EL sheet obtained as described above and sealing it with a moisture-proof film sandwiched between them.

“Production of EL device according to the present invention (5)” (Example 5)

Three

The aluminum sheet coated with a dielectric layer is coated on a 75 μm thick aluminum sheet so that the layer thickness is 30 μm and dried at 110 ° C. for 5 hours. Obtained. Subsequently, the average particle size Xia Bruno ethylcellulose solution硫I匕zinc particles and 30 mass ^_0/0 with an emission maximum copper and chlorine 15 m to 498nm was activated 1.2: mixed • 1 ratio After the dispersion, it was coated on the aluminum sheet coated with the dielectric layer so that the thickness of the luminescent particle layer was 45 m. This coating was dried at 110 ° C. for 5 hours using a hot air dryer. On the other hand, a film in which ΙΤΟ is evenly deposited to a thickness of 40 nm on polyethylene terephthalate with a thickness of 100 μm by sputtering is placed on the surface opposite to the one on which ITO is sputtered. The red luminescent pigment used in 3) was dispersed and applied to a solution of Zeonex made by Nippon Zeon Co., Ltd., and dried at 110 ° C for 3 hours to form a pigment film layer with a thickness of 10 / zm. . The EL device (5) of the present invention was obtained by thermocompression bonding these two coatings so that the luminescent particle layer and ITO were adjacent to each other, mounting a lead piece, and sealing with a moisture-proof film interposed therebetween. "Production of EL device according to the present invention (6)" (Example 6)

Three

The aluminum sheet coated with a dielectric layer is coated on a 75 μm thick aluminum sheet so that the layer thickness is 30 μm and dried at 110 ° C. for 5 hours. Obtained. Subsequently, the average particle size Xia Bruno ethylcellulose solution硫I匕zinc particles and 30 mass ^_0/0 with an emission maximum copper and chlorine 15 m to 498nm was activated 1.2: mixed • 1 ratio After the dispersion, it was coated on the aluminum sheet coated with the dielectric layer so that the thickness of the luminescent particle layer was 45 m. This coating was dried at 110 ° C. for 5 hours using a hot air dryer. On the other hand, a film in which ITO is uniformly deposited to a thickness of 40 nm by sputtering on polyethylene terephthalate having a thickness of 100 μm is made of poly (2-methoxy-5- {2′-ethylhexyloxy). Xy) 1,4-Ferene biylene (molecular weight 70000-100,000) was dispersed in cyanoethyl cellulose solution, coated and dried at 110 ° C. for 3 hours to form a 10 m thick layer. The EL device (6) of the present invention was obtained by thermocompression bonding these two coatings, placing a lead piece, and sealing with a moisture-proof film sandwiched between them.

[0102] FIGS. 2 and 3 show the spatter when the EL element of the present invention prepared as described above and the EL element of the comparative example emit light, and Table 1 shows a comparison of the color rendering properties at that time.

[0103] [Table 1] fii material Average color rendering index (Ra) R9 (red color rendering) R 1 1 (stock color rendering) R 15 (skinned female skin color) EL device of Comparative Example 1 6 4- 1 0 2 4 0 4 5 EL element of Comparative Example 2 6 9 4 7 0 7 4 EL element of the present invention (1) 7 6 3 8 8 2 8 7 EL element of the present invention (2) 7 3 7 8 7 8 8 9 EL device of the present invention (3) 7 6 8 9 7 6 8 5 EL device of the present invention (4) 8 3 9 6 8 7 8 9 EL device of the present invention (5) 7 4 3 4 7 6 7 7 EL element of the present invention (6) 7 4 5 4 8 1 8 0

[0104] When these elements were caused to emit light, their coordinates on the chromaticity diagram were (X, y) = (0.

313, 0. 336), (x, y) = (0. 324, 0. 326), whereas in the EL element of the present invention, the X force SO. 31 force et al. 0.33 f¾, y force SO.33 force and others were at 0.37.

It can be seen that the average color rendering index of the EL device of the present invention is superior to the conventional EL device of the comparative example, and in particular, it is excellent in red color rendering. The color rendering property of skin color, which is important when observing a transparent medium such as a transparent positive image on the EL element, is greatly improved in the EL element of the present invention.

Example 2

[0106] "Creation of EL device by conventional technology" (Comparative Example 1)

Mix and disperse copper / chlorine-activated zinc oxide particles with an average particle size of 15 m and 30% by weight of cyanethyl cellulose solution in a ratio of 1.2: 1, and then a red pigment manufactured by Sinloi ( 3% by weight of Sinroich FA-007) was added to and dispersed in the zinc oxide particles, and then ITO was sputtered onto a polyethylene terephthalate with a thickness of 100 microns to form a uniform film with a thickness of 40 nm. The luminescent particle layer was applied to a thickness of 50 m. This paint The fabric was dried at 110 ° C for 5 hours using a warm air dryer. The dielectric layer is dispersed to an average of 30 mass particles of particle size of 0. 2 μ m BaTiO ^_0/0 Xia Bruno cellulose solution

Three

The solution was obtained by applying the solution on an aluminum sheet having a thickness of 75 μm so that the dielectric layer had a thickness of 25 μm and drying it at 110 ° C. for 5 hours. The EL device of Comparative Example 1 was obtained by thermocompression bonding these two coated and dried products, mounting lead pieces, and sealing with a moisture-proof film sandwiched between them.

“Creation of EL device according to the present invention (1)”

Mix and disperse copper / chlorine-activated zinc oxide particles with an average particle size of 15 m and 30% by weight of cyanethylcellulose solution in a ratio of 1.2: 1, and then a 100 micron thick polyester. ITO was coated on the terephthalate with a uniform thickness of 40 nm by sputtering so that the thickness of the luminescent particle layer was 50 m. This coating was dried at 110 ° C for 5 hours using a hot air dryer, and then BaTiO fine particles with an average particle size of 0.2 / z m were obtained.

3 A solution in which the particles were dispersed in a 30 mass% cyanoethylcellulose solution was applied and dried at 110 ° C. for 5 hours. The thickness of this BaTiO layer (light scattering layer) was varied between 3 μm and 15 m

Three

Created something. A solution obtained by dispersing 30% by mass of a red pigment (Sinleuhi FA-007) made by Sinlohi Co., in cyclohexanol was applied onto the dried product and dried at 1 10 ° C for 2 hours to form a wavelength conversion material layer. Formed. The amount of red pigment applied was adjusted so that the coordinates on the chromaticity diagram of the finished device were between 0.32 and 0.34 for both x and y. The sheet thus obtained was mixed with 30% by mass of BaTiO fine particles having an average particle size of 0.2 μm.

Three

It was dispersed in a cyanoethyl cellulose solution and thermocompression bonded to a sheet coated on a 75 μm thick aluminum sheet. The dielectric layer thickness was adjusted so that the total thickness with the light scattering layer was 25 m. EL elements (1) to (6) of the present invention were prepared by placing lead pieces on the EL sheet obtained by these methods and sealing them with a moisture-proof film.

"Production of EL device according to the present invention (2)"

BaTiO coated between the luminescent particle layer and the wavelength converting material layer has an average particle size of 0.2 μm.

Three

m BaTiO fine particles mixed with BaTiO with an average particle size of 0.06 / z m

3 3

The EL elements obtained in the same manner as the EL element preparation (1) except for the above were used as EL elements (7) to (12) of the present invention.

Maximum emission wavelength of red light emission when the EL element of the present invention produced as described above is made to emit light Table 2 lists the brightness and brightness compared with those of the comparative example.

[0108] [Table 2]

* Luminance when driving the EL element at 100 V, 1 kHz

[0109] The spectrum of the EL device of the present invention satisfies the curve の (λ) described in claim 1, and the EL device prepared by the conventional technique (the spectrum does not satisfy the curve I (λ)). The emission maximum wavelength of red light emission was longer than that of,), and the red color was vividly expressed, and the color rendering was excellent. In addition, regarding the luminance during EL emission, the EL device of the present invention was higher in luminance than the EL device of the comparative example.

Industrial applicability

[0110] According to the present invention, there is provided an EL element which is particularly excellent in red color rendering and greatly improved in skin color rendering than conventional EL elements.

Claims

Claims [1] A dispersion-type electroluminescent device having a transparent electrode, a back electrode, and a luminescent particle layer sandwiched between the two electrodes is used to standardize the spectrum when the device emits light. Curved I (λ) force Dispersive electoluminescence element characterized by satisfying in the section of wavelength 410 nm or more and 650 nm or less. In the above formula, g () and f () are

[Number 1]

W = l.lexp (-ln (2) (^^) ² ) + 0.8exp (-ln (2) (^^) ¹ ) + 0.5exp (-ln (2) (^^) ³ ) It is a curved line.

[2] Curve I which shows the spectrum when the device emits light in a distributed type electroluminescent device having a transparent electrode, a back electrode, and a luminescent particle layer sandwiched between the two electrodes I (λ) force Dispersion type electroluminescent device characterized by satisfying the following conditions in a wavelength range of 400 nm to 700 nm.

In the above formula, g () and f () are

[Equation 2] gW = 0.9exp (-

Table with fW = l.lexp (-ln (2) (^^) 2) + 0.8exp ( one ^{ln (2) (^^) 2} ) + 0 .5exp (-ln (2) (^^) 2) Is a curved line.

[3] In an electroluminescence device having a transparent electrode, a back electrode, and a luminescent particle layer sandwiched between the two electrodes, a luminescent particle layer, a light scattering layer, a wavelength converting material layer, and a dielectric are interposed between the two electrodes. 3. The dispersion-type electoluminescence device according to claim 1, comprising body layers in this order.

4. The dispersive electoluminescent element _{n according} to claim 3, wherein the light scattering layer is thinner than the dielectric layer. In an electroluminescence element having a transparent electrode, a back electrode, and a luminescent particle layer sandwiched between the two electrodes, the luminescent particle layer and the dielectric layer are provided in this order between the two electrodes. 3. The dispersion type electroluminescent device according to claim 1, wherein the dielectric layer includes dielectric particles and a wavelength conversion material.