JP2007109575A - Substrate for electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate for an EL element which is hardly affected by the external light, and superior in display quality such as high contrast and high brightness, and in which light scattering intensity of the three primary colors is controllable. <P>SOLUTION: This is the substrate for the EL element that has a transparent substrate and a light scattering layer which is formed on the transparent substrate, in which particulates are dispersed in a transparent resin, and which is constituted of a scattering part for red light, a scattering part for green light, and a scattering part for blue light, wherein the abundance of the particulates contained respectively in the scattering part for the red light, in the scattering part for the green light, and in the scattering part for the blue light is mutually different. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electroluminescent element substrate used in, for example, an electroluminescent display device.

An electroluminescence (hereinafter abbreviated as EL) element utilizes the principle that a fluorescent substance or the like emits light by recombination energy between holes injected from an anode and electrons injected from a cathode when an electric field is applied. Self-luminous element. The EL element can emit surface light with high luminance of several thousand cd / m ² or more at a low voltage of several volts, and by appropriately selecting an organic compound or the like used for the light emitting layer or the like, from blue to red It has a feature that light emission of an arbitrary wavelength is possible. Since this EL element is a self-luminous element, it has a wide viewing angle and can respond at a high speed of less than μs. Therefore, active research and development has recently been conducted as a display device that can be changed to a liquid crystal display device or a plasma display. ing.

As an example of a basic structure of a conventional EL element, a structure in which a transparent electrode, a light emitting layer, and a back electrode are stacked on a transparent substrate can be exemplified. Usually, a metal electrode having reflection characteristics is used for the back electrode, and among the light emitted from the light emitting layer, the light emitted to the rear side (metal electrode side) of the light emitting layer is reflected by the metal electrode and forward Since it radiates | emits to (transparent electrode side), there exists an advantage that the brightness | luminance of an element improves.
However, since this metal electrode also reflects light incident on the element from the outside, there is a problem that reflection by external light occurs from a pixel that should not be displayed (non-light emitting), and display contrast is lowered. In particular, in a portable display device used in a bright environment such as outdoors, such reflection of external light becomes a problem.

In order to suppress such a decrease in contrast due to reflection of external light, a circularly polarizing plate is generally provided on the front surface of the transparent substrate (see, for example, Patent Document 1). When a circularly polarizing plate is used, the rotation direction of the circularly polarized light is reversed when the external light is reflected by the metal electrode, so that the reflection of the external light can be efficiently suppressed and a high contrast display can be obtained. .
However, since light emitted from the light emitting layer in the EL element is generally non-polarized light, when a circularly polarizing plate is used to prevent reflection of external light, about half of the emitted light is absorbed by the circularly polarizing plate. For this reason, there is a problem that the efficiency of taking out emitted light to the outside is reduced, and the luminance is reduced to half or less.

  Further, in the EL element, light having an incident angle greater than the critical angle determined by the refractive index of the transparent substrate and the refractive index of the output medium (for example, air) out of the light emitted from the light emitting layer is converted into the transparent substrate and the output medium. There is a problem that the light extraction efficiency is lowered because the light is totally reflected at the interface with the light-emitting layer and is confined inside the light emitting layer and cannot be extracted outside.

  Providing a light scattering layer has been proposed as a method for improving the light extraction efficiency (see, for example, Patent Documents 2 to 4). In the organic EL element having the above-described configuration, for example, when a light scattering layer is formed between the transparent substrate and the light emitting layer, the light scattering layer also guides light having an incident angle greater than the critical angle to the emission medium (for example, air). Will be. For this reason, the light extraction efficiency can be improved by forming the light scattering layer.

  However, even if the light scattering effect is obtained by the light scattering layer, the light scattering intensity depends on the wavelength, and the light having a shorter wavelength scatters more strongly. It will be bigger than that. Thus, when the scattering intensity of red light, green light and blue light is different, there is a problem that color shift occurs depending on the viewing angle.

Japanese Patent Laid-Open No. 8-322138 JP-A-6-347617 Japanese Patent Laid-Open No. 6-151061 JP 2004-39388 A

  The present invention has been made in view of the above problems, and is an EL element substrate that is hardly affected by external light, has excellent display quality such as high contrast and high brightness, and can control the scattering intensity of light of three primary colors. The main purpose is to provide

  In order to achieve the above object, the present invention provides a transparent substrate and fine particles dispersed in the transparent resin, the red light scattering portion, the green light scattering portion, and the blue light formed on the transparent substrate. A light scattering layer composed of a light scattering portion, and the abundances of the fine particles contained in the red light scattering portion, the green light scattering portion, and the blue light scattering portion are different from each other. An EL element substrate is provided.

  Since the EL element substrate of the present invention has a light scattering layer, when used in an EL display device, it suppresses reflection of external light and suppresses total reflection of light emission at the interface between the transparent substrate and the emission medium. Is possible. Also, the scattering intensity of light of the three primary colors is controlled by making the amount of the fine particles contained in the red light scattering portion, green light scattering portion, and blue light scattering portion constituting the light scattering layer different. It is possible to prevent occurrence of color shift depending on the viewing angle.

  In the above invention, the red light scattering portion, the green light scattering portion, and the blue light scattering portion may have different thicknesses. The concentration of the fine particles in the red light scattering portion, the green light scattering portion, and the blue light scattering portion may be different from each other. This is because the scattering intensity of light of the three primary colors can be effectively controlled by appropriately adjusting the thickness of each scattering portion or the concentration of fine particles in each scattering portion as described above.

  Furthermore, in this invention, even if the colored layer is formed in the surface on the opposite side to the surface in which the said transparent substrate of the said light-scattering layer is formed between the said transparent substrate and the said light-scattering layer. Good.

  In the present invention, a light shielding portion may be formed in the non-display area on the transparent substrate. This is because the contrast can be further improved.

  Furthermore, in the present invention, the average particle size of the fine particles is preferably in the range of 1.0 μm to 1.6 μm. Since the haze value can be increased by setting the average particle size of the fine particles within a predetermined range, when the EL element substrate of the present invention is used in an EL display device, reflection of external light is suppressed. This is because the contrast can be effectively improved and the light extraction efficiency can be effectively improved by suppressing the total reflection of light emission at the interface between the transparent substrate and the emission medium.

  Moreover, it is preferable that the board | substrate for EL elements of this invention has the haze value in the range of 30-95. This is because if the haze value is smaller than the above range, a sufficient light scattering effect may not be obtained.

  Furthermore, the present invention provides an EL display device using the above-described EL element substrate. Since the EL display device of the present invention uses the EL element substrate, color shift can be suppressed and visibility is good.

  When used in an EL display device, the EL element substrate of the present invention has the effect of realizing high contrast and high luminance display. Further, by making the abundances of the fine particles contained in the respective scattering portions constituting the light scattering layer different from each other, there is an effect that the light intensity of the three primary colors can be controlled.

  Hereinafter, the EL element substrate and the EL display device of the present invention will be described in detail.

A. EL Element Substrate The EL element substrate of the present invention is formed on a transparent substrate and the transparent substrate, in which fine particles are dispersed in a transparent resin, and includes a red light scattering portion, a green light scattering portion, and a blue light. A light scattering layer composed of a light scattering portion, and the amount of the fine particles contained in the red light scattering portion, the green light scattering portion, and the blue light scattering portion is different from each other. It is a feature.

The EL element substrate of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of an EL element substrate of the present invention. As illustrated in FIG. 1, an EL element substrate 10 of the present invention includes a transparent substrate 1 and a light scattering layer 2 formed thereon. The light scattering layer 2 is formed by dispersing fine particles in a transparent resin.

  Since the EL element substrate of the present invention has a light scattering layer, when used in an EL display device, reflection of external light is suppressed to improve contrast, and a transparent substrate and an emission medium (for example, air) It is possible to improve the light extraction efficiency by suppressing total reflection of light emission at the interface.

  As illustrated in FIG. 1, the light scattering layer 2 includes a red light scattering portion 2R, a green light scattering portion 2G, and a blue light scattering portion 2B, and each of the scattering portions 2R, 2G, and 2B. The abundance of the fine particles contained in is different depending on the light of the three primary colors.

  FIG. 2 is a graph showing an example of scattering characteristics of a conventional EL element substrate. This graph uses an EL element substrate having a transparent substrate and a light scattering layer, and the EL element substrate and the color filter are arranged in the order of the light source / color filter / EL element substrate / light receiver. This is a result of measuring the scattering intensity of each of red light (R), green light (G), and blue light (B) by placing the light receiver between the light receivers and changing the light receiver by ± 30 °. According to the graph illustrated in FIG. 2, for example, when the light receiving angle is 10 °, the scattering intensity decreases in the order of blue light (B)> green light (G)> red light (R). This is because the light scattering intensity depends on the wavelength, and light having a shorter wavelength is more strongly scattered.

  In the present invention, as described above, the abundances of the fine particles contained in the red light scattering portion, the green light scattering portion, and the blue light scattering portion are different from each other. Light scattering portion> green light scattering portion> blue light scattering portion. In general, the greater the amount of fine particles present, the greater the scattering intensity. Therefore, by reducing the amount of fine particles in the order of red light scattering portion> green light scattering portion> blue light scattering portion, red light scattering intensity is reduced. To increase the scattering intensity distribution of red light, green light, and blue light. Therefore, in the present invention, by appropriately adjusting the abundance of the fine particles in each scattering portion, the scattering characteristics depending on the wavelength of light as illustrated in FIG. 2 can be improved, thereby depending on the viewing angle. It is possible to suppress the occurrence of color shift.

  Further, when the EL element substrate of the present invention is applied to an EL display device using a light emitting layer that emits white light, white light from the light emitting layer mainly has a red component and a blue component, and has a blue tint. Therefore, it is preferable to adjust the abundance of fine particles in each scattering portion so that the scattering intensity of red light is increased with respect to blue light. In this case, the scattering intensity distribution of the light of the three primary colors is made uniform by decreasing the abundance of the fine particles in each scattering portion in the order of, for example, the scattering portion for red light> the scattering portion for green light≈the scattering portion for blue light. be able to.

  In the present invention, a colored layer may be formed on the light scattering layer. For example, as illustrated in FIG. 3A, a colored layer 3 may be formed between the transparent substrate 1 and the light scattering layer 2. Usually, the colored layer 3 includes a red colored pattern 3R, a green colored pattern 3G, and a blue colored pattern 3B.

Furthermore, in the present invention, a light shielding part may be formed in a non-display area on the transparent substrate. This light-shielding part is provided in order to align each scattering part and to shield between each scattering part.
Hereafter, each structure of the board | substrate for EL elements of this invention is demonstrated.

1. Light Scattering Layer The light scattering layer used in the present invention is sufficient to cause appropriate scattering in light emitted from the light emitting layer in the EL display device when the EL element substrate of the present invention is used in, for example, an EL display device. It is provided to ensure high visibility, and is obtained by dispersing fine particles having a light scattering action in a transparent resin.

The light scattering layer includes a red light scattering portion, a green light scattering portion, and a blue light scattering portion, and the abundance of fine particles contained in each scattering portion is different from each other. In the present invention, for example, by making the thickness of each scattering portion different, or by making the concentration of the fine particles in each scattering portion different, the abundance of the fine particles contained in each scattering portion is made different. be able to.
Note that the abundances of the fine particles contained in each scattering part are different from each other, not only when the abundances of all the fine particles are different among the three kinds of scattering parts, but also for the fine particles contained in at least two kinds of scattering parts. This includes cases where the abundance is different. For example, the amount of fine particles contained in the green light scattering portion and the blue light scattering portion is the same, and the amount of fine particles contained in the green light scattering portion and the blue light scattering portion is equal to the red light scattering portion. The abundance of fine particles contained in may be different.

  For example, when the thickness of each scattering portion is different, the thickness of each scattering portion is appropriately adjusted according to the intended scattering intensity of red light, green light, and blue light. Specifically, the thickness of each scattering portion is not particularly limited as long as the transparency of the light scattering layer is not impaired, and can be set at about 0.5 μm to 20 μm, preferably 1 It is in the range of 0.0 μm to 8.0 μm, and more preferably in the range of 1.5 μm to 6.5 μm from the viewpoint of patterning.

  In general, since light having a shorter wavelength scatters more strongly, for example, in order to correct variations in the scattering characteristics depending on the wavelength as shown in FIG. When it is constant, it is preferable that the thickness of each scattering portion becomes thinner in the order of red light scattering portion> green light scattering portion> blue light scattering portion. In this case, generally, the thicker the thickness, the greater the scattering intensity.

  In addition, when the EL element substrate of the present invention is applied to an EL display device using a light emitting layer that emits white light, as described above, the scattering intensity of red light can be increased with respect to blue light. It is preferable to adjust the thickness of each scattering portion. In this case, the scattering intensity distribution of each color can be made uniform by decreasing the thickness of each scattering portion in the order of, for example, the scattering portion for red light> the scattering portion for green light≈the scattering portion for blue light.

  The thickness of each scattering portion can be measured, for example, by observing the cross section of the EL element substrate with a scanning electron microscope (SEM).

  Thus, when the thickness of each scattering part differs, the density | concentration of the microparticles | fine-particles in each scattering part may be the same, and may differ.

  On the other hand, for example, when the concentration of the fine particles in each scattering portion is different, the concentration of the fine particles is appropriately adjusted according to the intended scattering intensity of red light, green light, and blue light. Specifically, the concentration of the fine particles in each scattering portion is not particularly limited as long as it is an amount that can scatter light and does not impair the transparency of the light scattering layer. It can be set at about 70% by weight, and is preferably in the range of 1.0% by weight to 50% by weight. This is because if the concentration of the fine particles is lower than the above range, the light scattering effect may not be obtained. Conversely, if the concentration of the fine particles is higher than the above range, it may be difficult to maintain the transparency and strength of the light scattering layer.

  In general, light having a shorter wavelength is more strongly scattered. Therefore, as in the case described above, for example, in order to correct the dispersion between the colors in the scattering characteristic depending on the wavelength as shown in FIG. When the thickness of the portion is constant, the concentration of the fine particles is preferably decreased in the order of red light scattering portion> green light scattering portion> blue light scattering portion. In this case, generally, the higher the concentration of fine particles, the greater the scattering intensity.

  In addition, when the EL element substrate of the present invention is applied to an EL display device using a light emitting layer that emits white light, as described above, the scattering intensity of red light can be increased with respect to blue light. It is preferable to adjust the concentration of the fine particles in each scattering portion, and by decreasing the concentration of the fine particles in each scattering portion, for example, in order of red light scattering portion> green light scattering portion≈blue light scattering portion. The scattering intensity distribution of each color can be made uniform.

  Thus, when the density | concentration of the microparticles | fine-particles in each scattering part differs, the thickness of each scattering part may be the same and may differ.

  As described above, the light scattering layer used in the present invention is obtained by dispersing fine particles having a light scattering action in a transparent resin. Hereinafter, the constituent material of the light scattering layer and other points will be described.

(1) Fine particles The fine particles used in the present invention are not particularly limited as long as they have a light scattering action. For example, inorganic substances such as silicon oxide, aluminum oxide, barium sulfate, acrylic resins, divinylbenzene Fine particles such as resin, benzoguanamine resin, styrene resin, melamine resin, acrylic-styrene resin, polycarbonate resin, polyethylene resin, polyvinyl chloride resin, or a mixture of two or more of these Can be mentioned.

  The fine particles preferably have transparency. This is because the total light transmittance can be improved. Of these, fine particles such as melamine resin, benzoguanamine resin, polymethyl methacrylate resin, and mixed resins and copolymers thereof are preferably used as such fine particles. These fine particles also have durability.

Here, it is generally known that the particle size of the fine particles greatly affects the optical design of the light scattering layer, and specifically, the scattering state varies depending on the particle size d of the fine particles. That is,
(1) When the particle size d is larger than the light wavelength λ (d> λ), the region becomes a geometric optical region, geometric optical refraction and scattering due to reflection occur, and there is no wavelength dependency.
(2) When the particle diameter d is close to the light wavelength λ (λ / 3 <d <λ), it becomes a diffraction scattering region (Mie scattering), and scattering due to geometric optical scattering and diffraction effect (light interference) occurs. And has a complicated wavelength dependency. For this reason, coloring due to scattering occurs.
(3) When the particle diameter d is smaller than the light wavelength λ (d <λ / 3), it becomes a Rayleigh scattering region, scattering due to interaction with atoms / molecules occurs, and the scattering is almost uniformly performed in all directions. For this reason, not only forward scattering but also back scattering occurs.

  When the EL element substrate of the present invention is used in an EL display device, the reflection of external light is suppressed to improve contrast, and the total reflection of light emission at the interface between the transparent substrate and the emission medium (for example, air) is suppressed. In order to improve the light extraction efficiency, omnidirectional scattering is not preferable. Therefore, it is preferable that the particle diameter of the fine particles corresponds to the case (1) or (2) having excellent forward scattering characteristics among the above. Furthermore, in order to prevent coloring due to scattering, the particle diameter of the fine particles is preferably in the geometric optical region (1).

  Moreover, in order to make the intensity of the scattered light by the light scattering layer sufficient, it is necessary to increase the haze value [haze value = (diffuse light transmittance) / (total light transmittance) × 100]. In particular, in an EL display device, a higher haze value is required. This is because, for example, external light is sometimes used as a light source in a liquid crystal display device. In this case, reflected light is actively used for display, whereas an EL element is a self-luminous element. This is because it is preferable to suppress reflection of external light in order to improve display quality. If the haze value is higher, reflection of external light can be effectively suppressed, and total reflection of light emission at the interface between the transparent substrate and the emission medium (for example, air) can also be effectively suppressed.

  In order to enable a high haze value (high degree of coarseness), it is necessary to increase the concentration of fine particles in each scattering part or increase the thickness of each scattering part. It is not preferable to decrease. For example, when titanium oxide or calcium carbonate, which is known as general fine particles, is used for the light scattering layer, the concentration of fine particles in the light scattering layer is increased or the thickness of the light scattering layer is increased. Although the haze value can be increased, the light shielding property of the fine particles is developed, and the total light transmittance is significantly reduced.

From the above, the average particle size of the fine particles used in the present invention is preferably in the range of 1.0 μm to 1.6 μm, preferably 1.0 μm to 1.4 μm, more preferably 1.2 μm to Within the range of 1.4 μm. This is because when the average particle size is in the above range, a high haze value can be achieved and excellent scattering characteristics can be obtained. As described above, only by controlling the concentration of the fine particles in the light scattering layer or the thickness of the light scattering layer, the haze value increases, but the total light transmittance may decrease. By setting it as the range, the haze value can be increased while suppressing a decrease in the total light transmittance. Furthermore, since reflection of external light can be suppressed without using a circularly polarizing plate as described above, when the EL element substrate of the present invention is used in an EL display device, light emission from the light emitting layer is performed. It can be used effectively and the luminance can be improved.
Furthermore, when the average particle diameter is in the above range, a uniform film thickness distribution can be achieved by application with a normal spinner, and a relatively thin light scattering layer having excellent patterning characteristics can be formed.

  As can also be explained from the relationship between the particle diameter d and the light wavelength λ, as the average particle diameter of the fine particles increases, the light intensity distribution of the three primary colors tends to be uniform. Considering the value, the average particle diameter of the fine particles is preferably in the above range. The haze value that serves as an index of the light scattering effect greatly depends on the average particle size of the fine particles, and it is considered that there is a suitable average particle size of the fine particles in order to obtain the light scattering effect in consideration of contrast, brightness, etc. Because.

  Here, the average particle diameter is generally used to indicate the particle size of the particles, and in the present invention, is a value measured by a laser method. The laser method is a method of measuring an average particle size, a particle size distribution, and the like by dispersing particles in a solvent and thinning and calculating scattered light obtained by applying a laser beam to the dispersion solvent. The average particle size is a value measured using a particle size analyzer Microtrac UPA Model-9230 manufactured by Leeds & Northrup as a particle size measuring device by a laser method.

  The shape of the fine particles is not particularly limited, but is preferably spherical.

  In the present invention, the refractive index of the fine particles is preferably larger than the refractive index of the transparent resin described later. Generally, in order to develop scattering characteristics, the refractive index difference between the fine particles and the transparent resin is used. Ideally, the refractive index of the transparent resin should be set to be larger than the refractive index of the fine particles. Is preferred. However, considering the difference in refractive index between the fine particles and the transparent resin and considering the coloring of the light scattering layer, it is preferable to set the refractive index of the fine particles to be larger than the refractive index of the transparent resin.

  Since the refractive index of a transparent resin to be described later is generally about 1.5, the refractive index of the fine particles is preferably larger than 1.5. Examples of such fine particles include aluminum oxide (1.62), benzoguanamine / formaldehyde condensate (1.66), benzoquamine / melamine / formaldehyde condensates (1.66, 1.52), and melamine / formaldehyde condensates ( 1.66), silica / acrylic compound (1.52), methacrylic compound (1.51) and the like. The numbers in parentheses indicate the refractive index.

(2) Transparent resin The transparent resin used in the present invention is appropriately selected in consideration of the refractive index difference from the fine particles, the transparency of the light scattering layer, the adhesion to the transparent substrate and the colored layer, and the like. Examples of the transparent resin include acrylic resins, epoxy resins, polyvinyl alcohol resins, polyimide resins, vinyl ether resins, and the like. These transparent resins can be used alone or as a mixture of two or more.

(3) Others The total light transmittance of the light scattering layer used in the present invention is preferably 85% or more, more preferably 90% or more, and most preferably 95% or more. This is because if the total light transmittance is too small, the luminance may decrease when the EL element substrate of the present invention is used in an EL display device.

  Moreover, it is preferable that the haze value of a light-scattering layer is about 30-95, More preferably, it exists in the range of 40-80, Most preferably, it exists in the range of 50-70. This is because if the haze value is smaller than the above range, a sufficient light scattering effect may not be obtained.

  In addition, said total light transmittance and haze value are the values measured with the direct reading haze meter by Toyo Seiki Seisakusho Co., Ltd. using the integrating sphere.

  Each scattering portion may be formed according to the pattern of the light emitting layer in the EL display device, and may be formed according to each color coloring pattern of the colored layer when a colored layer described later is formed. . The arrangement of the scattering portions is not particularly limited, and examples thereof include a stripe type, a mosaic type, a triangle type, and a four-pixel arrangement type.

  The light scattering layer used in the present invention can be formed by applying and solidifying a light scattering layer forming coating solution containing fine particles and a transparent resin. In this case, the light scattering layer forming coating solution is preferably an ultraviolet curable resist, and more preferably a negative ultraviolet curable resist. This is because, if the coating solution for forming the light scattering layer is an ultraviolet curable resist, it can be easily patterned by, for example, exposure through a photomask.

  At this time, the ultraviolet curable resist used contains an ultraviolet curable binder resin, a photopolymerization initiator, and the like. When a thick light scattering layer is formed by containing a large amount of this ultraviolet curable binder resin or photopolymerization initiator in an ultraviolet curable resist, the light scattering layer may be colored. For this reason, the thickness of the light scattering layer is preferably relatively thin.

  In addition, the light scattering layer forming coating solution is prepared for each scattering portion, and at this time, the addition amount of the fine particles is appropriately adjusted so that a scattering portion having a desired abundance can be formed. .

2. Transparent substrate The transparent substrate used in the present invention is not particularly limited as long as it can be generally used in an EL display device. For example, inflexible transparent rigid materials such as quartz glass, Pyrex (registered trademark) glass, and synthetic quartz plates, or transparent flexible materials having flexibility such as transparent resin films and optical resin plates may be used. it can. Among these, Corn 2000 Eagle 2000 or 1737 glass is a material having a small coefficient of thermal expansion, excellent dimensional stability and workability in high-temperature heat treatment, and is a non-alkali glass containing no alkali component in the glass. Are preferably used. In particular, the present invention is suitable when the EL element substrate of the present invention is applied to an active display type EL display device.

3. Colored layer In the present invention, a colored layer may be formed on the light scattering layer. The colored layer 3 may be formed between the transparent substrate 1 and the light scattering layer 2 as shown in FIG. 3A, for example. For example, as shown in FIG. You may form in the surface on the opposite side to the surface in which the board | substrate 1 was formed.
When a colored layer is formed between the transparent substrate and the light scattering layer, the transparent substrate surface is flatter than the light scattering layer, and therefore it is easy to form and pattern the colored layer. There are advantages. Further, since the colored layer for correcting the color characteristics is provided on the light exit surface side than the light scattering layer, a high contrast can be obtained even if the light scattering layer is colored. Furthermore, since the light scattering layer can be formed without being exposed to the heat process (post-bake) when forming the colored layer, it is possible to avoid yellowing of the transparent resin in the light scattering layer due to heat.

  The colored layer used in the present invention is composed of a red colored pattern, a green colored pattern, and a blue colored pattern. Usually, each color coloring pattern is provided corresponding to each scattering portion of the light scattering layer. The arrangement of each color coloring pattern is not particularly limited, and examples thereof include a stripe type, a mosaic type, a triangle type, and a four-pixel arrangement type.

  When the light-shielding part mentioned later is not formed in the non-display area | region on a transparent substrate, it is preferable that each color coloring pattern is formed without the gap. This is because the contrast can be improved.

  As a material for forming the colored layer, materials generally used for color filters can be applied, and examples thereof include organic pigments and inorganic pigments.

  Further, the thickness of the colored layer is not particularly limited, but is preferably a thickness capable of correcting colored characteristics of the light scattering layer. For example, the colored characteristics of the light scattering layer can be corrected by making the thickness of the colored layer relatively thin. In this case, the thickness of the colored layer is appropriately adjusted according to the target color characteristic correction.

  The colored layer can be formed by a general pigment dispersion method, dyeing method, electrodeposition method, printing method, or the like. In the case of forming a colored layer by a pigment dispersion method, a pigment dispersion resist in which the above-described organic pigment or inorganic pigment is dispersed is used as a colored layer forming coating solution.

  In order to form each color coloring pattern with high accuracy, an alignment mark is preferably formed. The alignment mark is usually formed simultaneously with the formation of the first color pattern. When a light shielding portion described later is formed at a predetermined position, this light shielding portion can be used as an alignment mark.

4). In the present invention, for example, as shown in FIG. 4, a light shielding portion 5 may be formed in a non-display area on the transparent substrate 1. The light shielding part shields light between the patterns of the light emitting layer in the EL display device, or aligns the scattering parts, or shields light between the colored patterns when the colored layer is formed, or In order to align each color coloring pattern, etc. are provided. By providing the light shielding portion, the contrast can be improved.

  Furthermore, the light-shielding portion only needs to be formed in a non-display area on the transparent substrate, and is formed on either the side of the transparent substrate where the light scattering layer is formed or the side where the light scattering layer is not formed. It may be.

  The light shielding part used in the present invention can be formed of, for example, a light shielding resin, a metal such as chromium, a resist in which a light shielding pigment is dispersed, or the like.

5. Flattening layer In the present invention, in order to eliminate the fine irregularities on the surface of the light scattering layer and form a flat surface, and when the thickness of each scattering portion is different, the flat surface without the step due to each scattering portion Or when the colored layer is formed, the surface of the colored layer is flat to eliminate the fine irregularities, and the irregularities due to the colored patterns of each color are eliminated. In order to form the surface, a planarizing layer may be formed on the light scattering layer or the colored layer.

  In particular, when an EL display device is manufactured using the EL element substrate of the present invention, for example, when a transparent electrode layer or the like is formed on a light scattering layer in the EL element substrate, the planarizing layer is formed. It is preferable that Since the light scattering layer contains fine particles, fine irregularities are likely to occur on the surface, and it may be difficult to form a uniform transparent electrode layer, but by the formation of a planarizing layer on the light scattering layer, This is because a uniform transparent electrode layer can be formed. In addition, when the thickness of each scattering portion is different, if a step due to each scattering portion is reflected in the transparent electrode layer, a short circuit may occur between the electrodes. This is because a short circuit can be prevented.

  In addition, when a colored layer is formed on the light scattering layer, it is possible to planarize fine irregularities on the surface of the light scattering layer by providing a planarizing layer between the light scattering layer and the colored layer. And the patterning characteristics of the colored layer are improved. Furthermore, in this case, since the planarizing layer is formed on the colored layer, a uniform transparent electrode layer can be formed as in the above case. Moreover, the short circuit between the electrodes which arises by the unevenness | corrugation by each color coloring pattern can be prevented by forming the planarization layer on the colored layer.

  On the other hand, for example, in the case where an EL display device is manufactured by separately manufacturing and bonding an EL element substrate and a counter substrate, the planarization layer may not be formed.

  The flattening layer is formed on the light scattering layer when only the light scattering layer is formed on the transparent substrate, but when the colored layer is formed, the light scattering layer and Regardless of the order of lamination of the colored layers, the light scattering layer and the colored layer may be formed on top of each other, or may be formed between the light scattering layer and the colored layer.

  The planarization layer used in the present invention can be formed using, for example, an acrylic resin, an epoxy resin, a vinyl ether resin, a polyimide resin, a propynyl resin, or the like.

6). Gas Barrier Layer In the present invention, a gas barrier layer may be formed on the light scattering layer. Since the light emitting layer and other organic layers in the EL display device are weak members against oxygen, water vapor, and other gases, the generation of dark spots and dark areas can be suppressed by providing a gas barrier layer. It is. In particular, when the colored layer is formed, a gas may be generated from the colored layer or the like during manufacture or driving of an EL display device. Can be prevented from deteriorating.

  When only the light scattering layer is formed on the transparent substrate, the gas barrier layer is formed on the light scattering layer, but when the colored layer is formed, the light scattering layer and the colored layer are formed. Are formed on the stacked layers.

  As the gas barrier layer, those generally used as a gas barrier layer of an EL display device can be used. For example, silicon oxide, silicon nitride, silicon oxynitride or the like is used.

7). Transparent electrode layer In the present invention, a transparent electrode layer may be formed on the light scattering layer. The transparent electrode layer is formed on the light scattering layer when only the light scattering layer is formed on the transparent substrate, but when the colored layer is formed, the light scattering layer and the colored layer are formed. Layers are formed on top of each other.

  As the transparent electrode layer used in the present invention, for example, indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), or an alloy thereof is used. The transparent electrode layer can be formed by a general film forming method such as a sputtering method, a vacuum vapor deposition method, a CVD method or the like.

  The thickness of the transparent electrode layer can be set to about 0.01 μm to 1 μm, and preferably about 0.03 μm to 0.5 μm.

8). Others The haze value of the EL device substrate of the present invention is preferably about 30 to 95, more preferably in the range of 40 to 80, and most preferably in the range of 50 to 70. This is because if the haze value is smaller than the above range, a sufficient light scattering effect may not be obtained. From the viewpoint of front luminance, the upper limit of the haze value is preferably 95.

  Further, the total light transmittance of the EL device substrate of the present invention is preferably 85% or more, more preferably 90% or more, and most preferably 95% or more. This is because if the total light transmittance is too small, the luminance may decrease when the EL element substrate of the present invention is used in an EL display device.

  The haze value and total light transmittance are values measured using a direct reading haze meter manufactured by Toyo Seiki Seisakusho.

  The EL element substrate of the present invention can be applied to a self-luminous display device such as an EL display device, a plasma display (PDP), or a field emission display (FED). By using the EL element substrate of the present invention, it is possible to obtain a display with excellent light scattering characteristics of the three primary colors and high contrast and high brightness.

B. EL Display Device Next, the EL display device of the present invention will be described. The EL display device of the present invention is characterized by using the above-described EL element substrate. Since the EL display device of the present invention uses the EL element substrate, color shift can be suppressed and visibility is good.
The EL display device may be an organic EL display device or an inorganic EL display device.

  In particular, the EL display device of the present invention is preferably driven by an active driving method. This is because the EL element substrate can suppress reflection of external light and is suitable for a display device used in a digital still camera or a digital video movie used in an external environment. In general, since a digital still camera, a digital video movie, or the like has a megapixel resolution, a resolution is also required for a display device that displays the resolution. A passive drive display device cannot obtain high resolution due to its configuration, and high-definition display devices have generally shifted to an active drive method. Further, regarding the display colors of colors, an active drive type display device capable of controlling an intermediate color with a thin film transistor (TFT) element can reproduce many display colors.

FIG. 5 shows an example of an EL display device of the present invention. FIG. 5A illustrates an example of a bottom emission EL display device, and FIG. 5B illustrates an example of a top emission EL display device.
For example, in the EL display device 30 shown in FIG. 5A, the transparent electrode layer 12, the light emitting layer 11, and the back electrode layer 13 are formed on the light scattering layer 2 (2R, 2G, and 2B) of the EL element substrate 10. A substrate 15 is formed thereon. A partition wall 16 is formed between the light emitting layers 12, and the transparent electrode layer 12 is formed together with a thin film transistor (TFT) 17.
For example, in the EL display device 30 shown in FIG. 5B, the back electrode layer 13, the light emitting layer 11, the transparent electrode layer 12, and the refractive index matching layer 14 are formed on the EL element substrate 10 and the substrate 15. The counter substrate 20 is laminated. A partition wall 16 is formed between the light emitting layers 12, and the back electrode layer 13 is formed together with a thin film transistor (TFT) 17.

  Among bottom emission and top emission, top emission is advantageous in that the ratio of the light emitting portion (aperture ratio) is large. This is because, in bottom emission, a TFT circuit is formed on the light extraction surface side, and the aperture ratio becomes narrow. However, in top emission, light is extracted from the surface opposite to the TFT circuit formation surface. This is because even if a complicated TFT circuit is formed, the aperture ratio is not affected.

The EL display device of the present invention may be, for example, one using a light emitting layer that emits white light, one using a light emitting layer that emits three primary colors, or one using a light emitting layer that emits blue light. Good.
In the case where the EL element substrate has a transparent substrate and a light scattering layer, an EL display device using light emitting layers that emit three primary colors is preferable. On the other hand, when the EL element substrate has a transparent substrate, a light scattering layer, and a colored layer, an EL display device using a light emitting layer that emits white light is preferably used.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be specifically described with reference to examples.

[Example 1]
(Formation of light shielding part)
As the transparent substrate, soda glass (manufactured by Central Glass Co., Ltd.) having a thickness of 370 mm × 470 mm and a thickness of 0.7 mm was used. On this transparent substrate, a thin film (thickness: 0.2 μm) of oxynitride composite chromium was formed by sputtering. A photosensitive resist is applied on the composite chrome thin film, mask exposure, development, and etching of the composite chrome thin film are sequentially performed, so that 80 μm × 280 μm rectangular openings have a pitch of 100 μm and a long side in the short side direction. Light-shielding portions arranged in a matrix at a pitch of 300 μm in the direction were formed.

(Formation of colored layer)
Red, green, and blue colored layer forming coating solutions were prepared. Condensed azo pigments (manufactured by Ciba Specialty Chemicals, Chromophthalred BRN) as red colorants, phthalocyanine green pigments (Lionol Green 2Y-301, manufactured by Toyo Ink Co., Ltd.), and blue as green colorants Anthraquinone pigments (manufactured by Ciba Specialty Chemicals, Chromophthal Blue A3R) were used as the colorant, and polyvinyl alcohol was used as the binder resin. Each coloring agent was blended at a ratio of 1 part (all parts are based on mass) to 10 parts of a 10% aqueous solution of polyvinyl alcohol. To 100 parts of the obtained solution, 1 part of ammonium dichromate was added as a crosslinking agent to obtain each colored layer forming coating solution.

  Each colored layer was formed using the above-described colored layer forming coating solutions sequentially. That is, a red colored layer forming coating solution was applied by spin coating on the transparent substrate on which the light shielding portion was formed, and prebaked at a temperature of 100 ° C. for 5 minutes. Then, it exposed using the photomask and developed with the developing solution (0.05% KOH aqueous solution). Next, post-baking was performed at a temperature of 200 ° C. for 60 minutes, and a band-like red colored layer having a width of 85 μm and a thickness of 1.5 μm was formed at a predetermined position of the light shielding portion. Thereafter, a green color layer and a blue color layer were formed using a green color layer forming coating solution and a blue color layer forming coating solution in this order.

(Formation of light scattering layer)
First, a coating solution for forming a light scattering layer was prepared.
<Preparation of curable resin composition>
In the polymerization tank, 63 parts by weight of methyl methacrylate (MMA), 12 parts by weight of acrylic acid (AA), 6 parts by weight of 2-hydroxyethyl methacrylate (HEMA), and 88 parts by weight of diethylene glycol dimethyl ether (DMDG) After stirring and dissolving, 7 parts by weight of 2,2′-azobis (2-methylbutyronitrile) was added and dissolved uniformly. Then, it stirred at 85 degreeC under nitrogen stream for 2 hours, and also was made to react at 100 degreeC for 1 hour. 7 parts by weight of glycidyl methacrylate (GMA), 0.4 parts by weight of triethylamine, and 0.2 parts by weight of hydroquinone were further added to the obtained solution, and the mixture was stirred at 100 ° C. for 5 hours to obtain a curable resin composition. (Solid content 50%) was obtained.
Next, the materials having the following composition were mixed and stirred at room temperature to obtain each coating solution for forming a light scattering layer.
<Composition of coating solution for forming light scattering layer for red>
-The above-mentioned curable resin composition (solid content 50%): 16 parts by weight-Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight- Orthocresol novolac-type epoxy resin (Oilized Shell Epoxy Epicoat 180S70): 4 Part by weight: 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight Diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size: 1.2 μm): 10 parts by weight <Composition of coating solution for forming light scattering layer for green>
-The above-mentioned curable resin composition (solid content 50%): 16 parts by weight-Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight- Orthocresol novolac-type epoxy resin (Oilized Shell Epoxy Epicoat 180S70): 4 Part by weight: 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight Diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size: 1.2 μm): 10 parts by weight <Composition of coating solution for forming light scattering layer for blue>
-The above-mentioned curable resin composition (solid content 50%): 16 parts by weight-Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight- Orthocresol novolac-type epoxy resin (Oilized Shell Epoxy Epicoat 180S70): 4 Part by weight: 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight Diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size: 1.2 μm): 10 parts by weight

  Next, a light diffusion layer corresponding to each colored layer was formed using the light scattering layer forming coating solution. That is, a coating solution for forming a light scattering layer for red is applied by spin coating on a substrate on which red, green, and blue colored layers are formed at predetermined positions of a light-shielding portion, and the temperature is 100 ° C. for 5 minutes. Pre-baked. Then, it exposed using the photomask and developed with the developing solution (0.05% KOH aqueous solution). Next, post baking was performed at a temperature of 200 ° C. for 60 minutes to form a strip-shaped red light diffusion layer having a thickness of 2.0 μm on the red colored layer. Thereafter, the green light-scattering layer forming coating liquid and the blue light-scattering layer forming coating liquid are sequentially used, and the green light-diffusing layer (thickness 1.8 μm) and the blue light-diffusing layer (thickness 1. 5 μm) was formed.

(Formation of planarization layer)
A coating solution for forming a planarization layer was prepared by diluting an acrylate-based photocurable resin (manufactured by Nippon Steel Chemical Co., Ltd., product name: “V-259PA / PH5”) with propylene glycol monomethyl ether acetate. This flattening layer forming coating solution was applied onto the light scattering layer by spin coating, and prebaked at a temperature of 120 ° C. for 5 minutes. Subsequently, after patterning by a photolithography method, post baking was performed at a temperature of 200 ° C. for 60 minutes to form a flattened layer having a thickness of 5 μm.

(Formation of gas barrier layer)
Next, a silicon oxynitride film having a thickness of 150 nm is formed on the planarizing layer by sputtering using an Si ₃ N ₄ target (3N), an argon gas introduction amount: 40 sccm, an RF power: 430 kW, and a substrate temperature: 100 ° C. A film was formed to form a transparent gas barrier layer.

(Formation of transparent electrode layer)
An indium tin oxide (ITO) film having a thickness of 150 nm is formed on the gas barrier layer by ion plating, a photosensitive resist is applied on the ITO film, mask exposure, development, and etching of the ITO film are performed. A transparent electrode layer was formed.
Next, a chrome thin film (thickness 0.2 μm) is formed by sputtering on the entire surface of the gas barrier layer so as to cover the transparent electrode layer, a photosensitive resist is applied on the chrome thin film, mask exposure, development, chromium The auxiliary electrode was formed by etching the thin film.

(Formation of insulating layer and partition)
An insulating layer forming coating solution obtained by diluting norbornene-based resin (manufactured by JSR: ARTON) having an average molecular weight of about 100,000 with toluene is used on the gas barrier layer so as to cover the transparent electrode layer by spin coating. After coating, baking (100 ° C., 30 minutes) was performed to form an insulating film (thickness 1 μm). Next, a photosensitive resist was applied on the insulating film, mask exposure, development, and etching of the insulating film were performed to form an insulating layer. This insulating layer was a strip-like pattern (width 20 μm) intersecting the transparent electrode layer at a right angle, and was located on the light shielding portion.

  Next, a partition wall-forming coating solution (Nippon Zeon Photoresist: ZPN1100) was applied over the entire surface by spin coating so as to cover the insulating layer, and prebaked (70 ° C., 30 minutes). Then, it exposes using the photomask for predetermined | prescribed partition, develops with a developing solution (Nippon-Zeon company make: ZTMA-100), then performs post-baking (100 degreeC, 30 minutes), and on an insulating layer A partition wall was formed.

(Formation of organic EL layer)
Subsequently, the organic EL layer which consists of a positive hole injection layer, a white light emitting layer, and an electron injection layer was formed by the vacuum evaporation method. That is, first, N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine is used as a predetermined opening corresponding to the image display area. A hole injection layer was formed on the transparent electrode layer by vapor deposition up to 600 nm through a photomask provided with a film. Similarly, 4,4′-bis (2,2-diphenylvinyl) biphenyl was deposited to 50 nm to form a film. At the same time, a small amount of rubrene (manufactured by Aldrich Co., Ltd., fluorescence peak wavelength: 585 nm) was contained. This formed the white light emitting layer. Thereafter, tris (8-quinolinol) aluminum was deposited to a thickness of 20 nm to form a film, thereby forming an electron injection layer. The organic EL layer thus formed was present between the partition walls as a strip-shaped pattern having a width of 280 μm.

(Formation of back electrode layer)
Next, magnesium and silver are simultaneously vapor-deposited in a region where the partition wall is formed through a photomask having a predetermined opening wider than the image display region by a vacuum vapor deposition method (magnesium vapor deposition rate = 1. 3 to 1.4 nm / second, silver deposition rate = 0.1 nm / second). Thereby, the partition wall was used as a mask to form a 200 nm-thick back electrode layer made of magnesium / silver compound on the organic EL layer. This back electrode layer was present on the organic EL layer as a band-like pattern having a width of 280 μm.

(Organic EL display device)
The organic EL element was sealed to obtain an organic EL display device. The transparent electrode layer and the back electrode layer intersect each other by applying a voltage of DC 8.5 V to the transparent electrode layer and the back electrode layer of this organic EL display device at a constant current density of 10 mA / cm ² and driving them continuously. The white light emitting layer at the desired site was caused to emit light.

[Example 2]
In Example 1, an organic EL display device was produced in the same manner as Example 1 except that the light scattering layer was formed as follows.
(Formation of light scattering layer)
The materials having the following composition were mixed and stirred at room temperature to prepare each coating solution for forming a light scattering layer. The curable resin composition used was the same as in Example 1.
<Composition of coating solution for forming light scattering layer for red>
Curable resin composition (solid content 50%): 16 parts by weight Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight Orthocresol novolac type epoxy resin (Oka Chemical Shell Epoxy Co., Ltd. Epicoat 180S70): 4 weights Parts: 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size: 1.2 μm): 12 Weight part <Composition of coating solution for forming light scattering layer for green>
Curable resin composition (solid content 50%): 16 parts by weight Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight Orthocresol novolac type epoxy resin (Oka Chemical Shell Epoxy Co., Ltd. Epicoat 180S70): 4 weights Part 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size 1.2 μm): 10 parts Part by weight <Composition of coating solution for forming light scattering layer for blue>
Curable resin composition (solid content 50%): 16 parts by weight Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight Orthocresol novolac type epoxy resin (Oka Chemical Shell Epoxy Co., Ltd. Epicoat 180S70): 4 weights Parts 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight diethylene glycol dimethyl ether: 52 parts by weight Melamine-based resin beads (average particle size 1.2 μm): 8 Parts by weight

  Next, the same procedure as in Example 1 was performed except that the thickness of the red light diffusion layer was 2.0 μm, the thickness of the green light diffusion layer was 2.0 μm, and the thickness of the blue light diffusion layer was 2.0 μm. Thus, a light diffusion layer was formed.

[Example 3]
In Example 1, an organic EL display device was produced in the same manner as Example 1 except that the light scattering layer was formed as follows.
(Formation of light scattering layer)
The materials having the following composition were mixed and stirred at room temperature to prepare each coating solution for forming a light scattering layer. The curable resin composition used was the same as in Example 1.
<Composition of coating solution for forming light scattering layer for red>
Curable resin composition (solid content 50%): 16 parts by weight Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight Orthocresol novolac type epoxy resin (Oka Chemical Shell Epoxy Co., Ltd. Epicoat 180S70): 4 weights Part 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size 1.6 μm): 10 parts Weight part <Composition of coating solution for forming light scattering layer for green>
Curable resin composition (solid content 50%): 16 parts by weight Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight Orthocresol novolac type epoxy resin (Oka Chemical Shell Epoxy Co., Ltd. Epicoat 180S70): 4 weights Part 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size 1.6 μm): 10 parts Part by weight <Composition of coating solution for forming light scattering layer for blue>
Curable resin composition (solid content 50%): 16 parts by weight Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight Orthocresol novolac type epoxy resin (Oka Chemical Shell Epoxy Co., Ltd. Epicoat 180S70): 4 weights Part 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size 1.6 μm): 10 parts Parts by weight

  Next, the same procedure as in Example 1 was performed except that the thickness of the red light diffusion layer was 2.0 μm, the thickness of the green light diffusion layer was 1.8 μm, and the thickness of the blue light diffusion layer was 1.5 μm. Thus, a light diffusion layer was formed.

[Comparative Example 1]
In Example 1, an organic EL display device was produced in the same manner as Example 1 except that the light scattering layer was formed as follows.
(Formation of light scattering layer)
The materials having the following composition were mixed and stirred at room temperature to prepare each coating solution for forming a light scattering layer. The curable resin composition used was the same as in Example 1.
<Composition of coating solution for forming light scattering layer for red>
Curable resin composition (solid content 50%): 16 parts by weight Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight Orthocresol novolac type epoxy resin (Oka Chemical Shell Epoxy Co., Ltd. Epicoat 180S70): 4 weights Part 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size 1.2 μm): 10 parts Weight part <Composition of coating solution for forming light scattering layer for green>
Curable resin composition (solid content 50%): 16 parts by weight Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight Orthocresol novolac type epoxy resin (Oka Chemical Shell Epoxy Co., Ltd. Epicoat 180S70): 4 weights Part 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size 1.2 μm): 10 parts Part by weight <Composition of coating solution for forming light scattering layer for blue>
Curable resin composition (solid content 50%): 16 parts by weight Dipentaerythritol pentaacrylate (Sartomer SR399): 24 parts by weight Orthocresol novolac type epoxy resin (Oka Chemical Shell Epoxy Co., Ltd. Epicoat 180S70): 4 weights Part 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one: 4 parts by weight diethylene glycol dimethyl ether: 52 parts by weight Melamine resin beads (average particle size 1.2 μm): 10 parts Parts by weight

  Next, the same procedure as in Example 1 was performed except that the thickness of the red light diffusion layer was 2.0 μm, the thickness of the green light diffusion layer was 2.0 μm, and the thickness of the blue light diffusion layer was 2.0 μm. Thus, a light diffusion layer was formed.

[Evaluation]
Color shift (Δxy in CIE chromaticity coordinates) and brightness when tilting 45 ° with respect to the front of the substrate with a spectral radiance meter (SR-2 manufactured by Topcon Co., Ltd.) for an arbitrary area of the organic EL display device The visibility under the room (external light reflection reduction effect) was evaluated.

Here, Δxy is obtained from the following equation from the White coordinates (x2, y2) when inclined by 45 ° with respect to the substrate surface with respect to the White coordinates (x1, y1) at the front of the substrate when all colors are lit. Calculated.
Δxy = ((x1−x2) ² + (y1−y2) ² ) ^1/2

Further, the haze value of the light scattering layer was measured with a direct reading haze meter manufactured by Toyo Seiki Seisakusho.
The results are shown in Table 1. In addition, the density | concentration of microparticles | fine-particles in Table 1 is a ratio (%) of microparticle weight with respect to the total weight of solid content in each coating liquid for light diffusion layer formation.

It is a schematic sectional drawing which shows an example of the board | substrate for EL elements of this invention. It is a graph which shows an example of the scattering characteristic of the conventional board | substrate for EL elements. It is a schematic sectional drawing which shows the other example of the board | substrate for EL elements of this invention. It is a schematic sectional drawing which shows the other example of the board | substrate for EL elements of this invention. It is a schematic sectional drawing which shows an example of the EL display apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Light scattering layer 2R ... Red light scattering part 2G ... Green light scattering part 2B ... Blue light scattering part 3 ... Colored layer 5 ... Light-shielding part 10 ... EL element substrate

Claims (8)

  A transparent substrate, and a light scattering layer formed on the transparent substrate, in which fine particles are dispersed in a transparent resin, and comprising a red light scattering portion, a green light scattering portion, and a blue light scattering portion. A substrate for an electroluminescence element, wherein the abundances of the fine particles contained in the red light scattering portion, the green light scattering portion, and the blue light scattering portion are different from each other.   2. The electroluminescent element substrate according to claim 1, wherein the red light scattering portion, the green light scattering portion, and the blue light scattering portion have different thicknesses.   3. The electroluminescent device substrate according to claim 1, wherein concentrations of the fine particles in the red light scattering portion, the green light scattering portion, and the blue light scattering portion are different from each other.   The colored layer is formed between the transparent substrate and the light scattering layer or on the surface of the light scattering layer opposite to the surface on which the transparent substrate is formed. The substrate for electroluminescent elements according to any one of claims 1 to 3.   The electroluminescent element substrate according to any one of claims 1 to 4, wherein a light-shielding portion is formed in a non-display area on the transparent substrate.   6. The electroluminescent element substrate according to claim 1, wherein an average particle diameter of the fine particles is in a range of 1.0 μm to 1.6 μm.   The substrate for electroluminescent elements according to any one of claims 1 to 6, wherein a haze value is in a range of 30 to 95. An electroluminescence display device using the electroluminescence element substrate according to any one of claims 1 to 7.

Images