JP5034220B2 - Color filter substrate for organic electroluminescence device - Google Patents

Description

  The present invention relates to a color filter substrate for an organic EL element used in an organic electroluminescence (hereinafter abbreviated as EL) display device.

  In principle, the organic EL element has a structure in which a light emitting layer is sandwiched between an anode and a cathode. Actually, when an organic EL display device for color display is configured using organic EL elements, (1) a method of arranging light emitting layers that emit light of each of the three primary colors, (2) a light emitting layer that emits white light, There are a color filter system combining three primary color layers, and (3) a color conversion system combining a light emitting layer emitting blue light and a color conversion layer converting blue light into green light and red light, respectively.

  In the method (1), it is necessary to make the characteristics of the light emitting layers that emit light of the respective colors uniform, and there is a problem that high-definition patterning is difficult. Therefore, the color filter method (2) and the color conversion method (3) are attracting attention. Since these methods need only use a single type of light-emitting layer, there is no problem like the method (1).

  However, the color conversion method (3) has a problem in that the phosphor in the color conversion layer is excited by external light and the contrast is lowered. For this reason, a colored layer is generally formed between the color conversion layer and the transparent substrate. Moreover, color purity can be improved by providing a colored layer. However, since the color conversion layer is relatively thick, there is a problem in that the light use efficiency is low because light emitted from the phosphor is scattered due to scattering.

  On the other hand, in the color filter system of (2) above, a color conversion layer may be formed between the light emitting layer and the colored layer for hue correction. This is because a general light-emitting light source of a light-emitting layer emits white light with two wavelengths mainly including a blue component and a red component, so that there is little green component, and if hue correction is realized with a colored layer, the green display becomes weak. It is. However, when a color conversion layer is provided, a color conversion layer that converts incident light into green is formed, so that the film thickness of that portion is increased, and no color conversion layer is formed for blue and red. This causes a problem that the transparent electrode layer formed on the colored layer and the color conversion layer is easily disconnected. Also in this case, similarly, since the color conversion layer is relatively thick, light leaks due to light scattering or the like, and thus there is a problem that the light use efficiency is low.

  Further, hue correction and luminance, that is, light extraction efficiency are incompatible with each other, and it is difficult to achieve both improvement in color purity and improvement in luminance.

  Examples of improving the luminance by increasing the light extraction efficiency include a method of providing a light-shielding portion having reflectivity between each color conversion layer (see, for example, Patent Document 1), or a formation between a light emitting layer and a color conversion layer. A method of adjusting the refractive index of the layer to be formed (see, for example, Patent Document 2) has been proposed. However, no example has been reported in which the luminance is improved by the configuration of the color conversion layer itself.

JP 2004-288447 A JP 2003-0777680 A

  The present invention has been made in view of the above problems, and a main object of the present invention is to provide a color filter substrate for an organic EL element capable of obtaining an organic EL display device having high luminance and high efficiency.

  In order to achieve the above object, the present invention includes a transparent substrate, a colored layer formed in a pattern on the transparent substrate, and a color conversion layer partially formed on the colored layer. A color filter substrate for an organic EL element is provided.

In the present invention, since the color conversion layer is partially formed on the colored layer, in the organic EL display device using such a color filter substrate for an organic EL element, one of the light emitted from the light emitting layer is used. The portion is transmitted through the color conversion layer. At this time, incident light is absorbed by the color conversion phosphor in the color conversion layer and fluorescence is emitted, but this fluorescence is scattered by other color conversion phosphors in the color conversion layer and leaks from the side surface of the color conversion layer. End up. In the present invention, since the color conversion layer is partially formed on the colored layer, the scattered and leaked light can be emitted from a region on the colored layer where the color conversion layer is not formed. As a result, light scattered and leaked in the color conversion layer can be efficiently extracted, and the luminance can be improved. Therefore, by using the organic EL element color filter substrate of the present invention, it is possible to provide an organic EL display device with high luminance and high efficiency.
Further, as described above, hue correction and luminance are incompatible with each other, but in the present invention, the above configuration can achieve both high color purity and high light extraction efficiency.

  In the said invention, it is preferable that the said color conversion layer is formed in the pattern form on the said colored layer. Since the color conversion layer is formed in a pattern on the colored layer, the surface area of the color conversion layer is increased, so that the light scattered and leaked in the color conversion layer can be extracted more efficiently, and the luminance can be increased. This is because it can be further improved.

  In the present invention, the colored layer has a red colored portion, a green colored portion, and a blue colored portion, and the color conversion layer is partially formed on the red colored portion. It is preferable to have at least one of the green color conversion parts partially formed on the green coloring part. Since each color conversion part is partially formed on each coloring part, light scattered and leaked in each color conversion part can be efficiently extracted, and the brightness of red light and green light can be improved. Because you can.

  In the said invention, the red color conversion part does not need to be formed on the said red coloring part. This is because when the incident light is white light including components of red light and blue light, for example, a red color conversion unit that converts the incident light into red light may not be formed. Moreover, it is not necessary to repeat the patterning process, which is advantageous in terms of cost and simplifies the manufacturing process.

  In the present invention, it is preferable that a planarization layer is formed on the color conversion layer. This is because the colored layer and the color conversion layer can be protected by forming the planarizing layer. Moreover, when the color filter substrate for organic EL elements of the present invention is used in an organic EL display device, it is possible to reduce the influence at the time of forming the transparent electrode layer and prevent the occurrence of thickness unevenness at the time of forming the organic EL layer. Because it can.

  In this case, the planarization layer may have light scattering properties. By the light-scattering property of the flattening layer, the light converted by the color conversion layer is prevented from leaking in the direction horizontal to the transparent substrate, and the direction perpendicular to the transparent substrate (observer side) This is because light can be extracted efficiently.

  Furthermore, in the present invention, it is preferable that a gas barrier layer is formed on the color conversion layer. Due to the formation of the gas barrier layer, when the color filter substrate for organic EL elements of the present invention is used in an organic EL display device, it is vulnerable to water vapor, oxygen, or desorbed gas from a colored layer, a color conversion layer, or the like. This is because the organic EL layer as a member can be protected from such a gas.

  Moreover, in this invention, the light shielding part may be formed between the said colored layers on the said transparent base material. This is because the formation of the light-shielding portion partitions areas that emit light for each pixel, prevents reflection of external light at the boundaries between the areas that emit light, and increases contrast.

  The present invention is also formed on the transparent electrode layer, the color filter substrate for organic EL elements described above, the transparent electrode layer formed on the color conversion layer side surface of the color filter substrate for organic EL elements, An organic EL display device comprising: an organic EL layer including at least a light emitting layer; and a counter electrode layer formed on the organic EL layer.

  Since the organic EL display device of the present invention uses the above-described color filter substrate for an organic EL element, it is possible to efficiently extract light scattered and leaked in the color conversion layer and to improve luminance. . Therefore, high brightness and high efficiency can be realized.

  In the said invention, it is preferable that the said light emitting layer is what light-emits white by a 2 wavelength light emission light source. In general, white light emitted from a light emitting layer that emits white light includes components of red light and blue light, and often does not include a component of green light. Therefore, a green color conversion unit that converts incident light into green light is formed. It is common. Therefore, in the present invention, the luminance of green light can be improved by, for example, partially forming the green color conversion portion on the green coloring portion. Therefore, an organic EL display device having an excellent balance of color characteristics of the three primary colors can be obtained.

  In the present invention, since the color conversion layer is partially formed on the colored layer, the light scattered and leaked in the color conversion layer can be efficiently extracted, and the luminance can be improved. Play. Therefore, in the organic EL display device using the color filter substrate for organic EL elements of the present invention, it is possible to achieve high luminance and high efficiency.

  Hereinafter, the color filter substrate for organic EL elements of the present invention and the organic EL display device using the same will be described in detail.

A. Color filter substrate for organic EL element The color filter substrate for organic EL element of the present invention is partially formed on a transparent substrate, a colored layer formed in a pattern on the transparent substrate, and the colored layer. And a color conversion layer.

The color filter substrate for organic EL elements of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of a color filter substrate for an organic EL element of the present invention. As shown in FIG. 1, in the color filter substrate 10 for organic EL elements of the present invention, a colored layer 2 composed of a red colored portion 2R, a green colored portion 2G, and a blue colored portion 2B on the transparent substrate 1, A red color conversion unit 3R formed on the red coloring unit 2R and a color conversion layer 3 composed of the green color conversion unit 3G formed on the green coloring unit 2G are sequentially formed. A planarization layer 5 is formed so as to cover the layer 3. A black matrix 4 is formed between the colored portions 2R, 2G, and 2B of the colored layer 2. Further, the red color conversion unit 3R and the green color conversion unit 3G are partially formed on the red coloring unit 2R and the green coloring unit 2G, respectively. A transmissive portion 3B ′ that transmits incident light is formed on the blue colored portion 2B.
Note that the transmissive portion 3B ′ in FIG. 1 may not be formed. Further, when the transmissive portion 3B ′ is not formed, the thickness of the blue colored portion 2B is changed to the total thickness of the red colored portion 2R and the red color converting portion 3R, or the green colored portion 2G and the green color converted for the purpose of film thickness adjustment. You may make it thick so that it may become comparable as the total thickness of the part 3G.

  When an organic EL display device is manufactured using the color filter substrate for organic EL elements shown in FIG. 1, a transparent electrode layer, a light emitting layer, and a counter electrode layer are sequentially stacked on the planarizing layer 5. In such an organic EL display device, part of the light emitted from the light emitting layer passes through the color conversion layer 3 and further passes through the colored layer 2, and the other part passes through the color conversion layer 3. Without passing through the colored layer 2.

  About some light which permeate | transmits the color conversion layer 3 and the colored layer 2, since incident light is absorbed in the color conversion fluorescent substance in the color conversion layer 3, and fluorescence is emitted, it becomes light by which the hue was correct | amended. The hue-corrected light is scattered by other color conversion phosphors in the color conversion layer 3 and leaks from the side surface of the color conversion layer 3. In the present invention, the color conversion layer 3 is on the colored layer 2. Therefore, the scattered and leaked light can be emitted from a region on the colored layer 2 where the color conversion layer 3 is not formed. As a result, light that has been scattered and leaked in the color conversion layer can be efficiently extracted, and luminance can be improved.

In particular, when an inorganic phosphor is used as the color conversion phosphor, the inorganic phosphor is generally opaque, and the fluorescence emitted from one inorganic phosphor in the color conversion layer is different from other inorganic phosphors. Since the light cannot be transmitted, the luminance can be effectively improved by adopting the structure of the present invention.
Hereinafter, each structure of the color filter substrate for organic EL elements of this invention is demonstrated.

1. Color conversion layer The color conversion layer used in the present invention is partially formed on the colored layer. The formation position of the color conversion layer is not particularly limited as long as it is a part on the colored layer. For example, as shown in FIG. 1, the color conversion layer 3 (3R) is formed at the center of the colored layer 2 (2R, 2G). 3G) may be formed, and the color conversion layer 3 (3R, 3G) may be formed on the colored layer 2 (2R, 2G) as shown in FIG. Further, for example, as shown in FIG. 1, the color conversion layer 3 (3R, 3G) may be formed at one place on the colored layer 2 (2R, 2G). For example, as shown in FIG. (3R, 3G) may be formed in a pattern on the colored layer 2 (2R, 2G).

  The color conversion layer used in the present invention is obtained by dispersing or dissolving a color conversion phosphor that absorbs incident light and emits fluorescence of each color in a resin. As the color conversion phosphor, either an inorganic phosphor or an organic phosphor can be used.

  When an inorganic phosphor is used as the color conversion phosphor, the color conversion layer is preferably formed in a pattern on the colored layer. This is because, as described above, the inorganic phosphor is generally opaque, and the light emitted from one inorganic phosphor in the color conversion layer cannot be transmitted through the other inorganic phosphor but is scattered. This is because it is preferable to increase the surface area of the color conversion layer in order to efficiently extract the scattered and leaked light and improve the luminance. Therefore, when an inorganic phosphor is used, the color conversion layer is preferably formed in a fine pattern on the colored layer. At this time, since it is difficult to form a pattern that is too fine, the fineness of the pattern of the color conversion layer is preferably selected as appropriate in consideration of the intended luminance and patterning characteristics.

  On the other hand, when an organic phosphor is used, the preferred formation position of the color conversion layer is not particularly limited. For example, the color conversion layer may be formed in one place on the colored layer. It may be formed in a pattern on top.

  The occupied area ratio of the color conversion layer to the colored layer in the present invention is not particularly limited as long as light extraction efficiency is improved and high luminance is obtained. The preferred range differs depending on the use. When the inorganic phosphor is used, the occupied area ratio of the color conversion layer to the colored layer is preferably about 20 to 90, more preferably 50 to 80, and still more preferably 70 to 70, where the area of the colored layer is 100. Within the range of 80. On the other hand, when the organic phosphor is used, the occupied area ratio of the color conversion layer to the colored layer is preferably about 70 to 100, more preferably 80 to 98, and still more preferably, where the area of the colored layer is 100. Within the range of 85-95. In any case, if the ratio of the area occupied by the color conversion layer to the colored layer is too small, the color conversion efficiency may be lowered. If the ratio is too large, the colored layer can emit light scattered and leaked in the color conversion layer. This is because the upper region is narrowed, so that the light extraction efficiency is lowered, and the luminance improvement effect may not be obtained.

  The “occupied area ratio of the color conversion layer to the colored layer” referred to herein is, for example, as shown in FIG. ) Refers to the occupied area ratio relative to 2R, not the occupied area ratio of the entire color conversion layer to the entire colored layer.

  In addition, the thickness of the color conversion layer is not particularly limited as long as the light extraction efficiency is improved and high luminance is obtained, but it is preferable when an inorganic phosphor is used and when an organic phosphor is used. The range is different.

  When an inorganic phosphor is used, the thickness of the color conversion layer is preferably about 0.2 μm to 10 μm, more preferably 0.5 μm to 5 μm, and still more preferably 1 μm to 3 μm. This is because if the color conversion layer is too thick, the light emitted from one inorganic phosphor cannot pass through the other inorganic phosphor as described above, and the luminance may decrease. Conversely, if the thickness of the color conversion layer is too thin, the color conversion efficiency may decrease. In addition, it is possible to reduce the thickness of the color conversion layer without decreasing the color conversion efficiency by increasing the content of the inorganic phosphor in the color conversion layer, but the inorganic phosphor in the color conversion layer If the content is too large, concentration quenching may occur. Therefore, when the content of the inorganic phosphor in the color conversion layer is increased to reduce the thickness of the color conversion layer, the thickness is appropriately selected in consideration of concentration quenching.

  On the other hand, when an organic phosphor is used, the thickness of the color conversion layer is preferably about 0.5 μm to 30 μm, more preferably 1 μm to 10 μm, and still more preferably 3 μm to 5 μm. This is because if the thickness of the color conversion layer is too thick, the level difference (unevenness) due to the configuration of the color conversion layer increases, and it becomes difficult to flatten the surface. Conversely, if the thickness of the color conversion layer is too thin, the color conversion efficiency may be reduced. Similarly to the above, concentration quenching may occur when the content of the organic phosphor in the color conversion layer is increased in order to reduce the thickness of the color conversion layer.

  The color conversion layer used in the present invention is provided corresponding to the colored layer, and usually has three types of color conversion units, a red color conversion unit, a green color conversion unit, and a blue color conversion unit. . In the present invention, as described above, the color conversion layer is partially formed on the colored layer. However, all three types of color conversion portions may be partially formed on the colored layer. One type or two types of color conversion units among the types of color conversion units may be partially formed on the colored layer.

  Moreover, the structure of the color conversion layer used for this invention changes with structures of the light emitting layer of the organic electroluminescence display to which the color filter substrate for organic EL elements of this invention is applied.

  When the color filter substrate for organic EL elements of the present invention is used for an organic EL display device having a blue light emitting layer that emits blue light, for example, the incident light to the color conversion layer generally contains a component of blue light, or blue light and In many cases, it contains a green light component.

  When the incident light to the color conversion layer includes a blue light component, the color conversion layer includes a red color conversion unit that converts the incident light into red light and a green color conversion unit that converts the incident light into green light. It should be at least.

  In this case, only the red color conversion part may be partially formed on the red color part, or only the green color conversion part may be partially formed on the green color part, and the red color conversion part and The green color conversion part may be partially formed on each coloring part. Especially, it is preferable that both the red color conversion part and the green color conversion part are partially formed on each coloring part. This is because, with such a configuration, light scattered and leaked in the red color conversion unit and the green color conversion unit can be efficiently extracted, and the luminance can be further improved. In particular, when an inorganic phosphor is used as the color conversion phosphor, it is preferable that the red color conversion unit 3R and the green color conversion unit 3G are formed in a pattern, for example, as shown in FIG. As described above, the red color conversion unit and the green color conversion unit are formed in a pattern and the surface area thereof is increased, so that the light scattered and leaked in the red color conversion unit and the green color conversion unit can be more efficiently This is because it can be taken out and the luminance can be further improved.

Further, in this case, since the incident light to the color conversion layer includes a blue light component, the blue color conversion unit does not need to perform color conversion in principle, so even if the blue color conversion unit is not formed. Good. Therefore, nothing may be formed on the blue colored portion, but in order to flatten the surface of the color filter substrate for the organic EL element, for example, as shown in FIGS. A transmissive portion 3B ′ having the same thickness may be formed.
This transmissive part transmits incident light and is not particularly limited as long as it transmits blue light when formed on a blue colored part, and does not include, for example, a color conversion phosphor. It can be made of a resin described later. In this case, since the transmissive part does not contain the color conversion phosphor, it is not necessary to be partially formed on the blue colored part in order to improve the luminance. It is common to form.

  On the other hand, when the incident light to the color conversion layer includes blue light and green light components, the color conversion layer may have at least a red color conversion unit that converts the incident light into red light. In this case, the red color conversion part is partially formed on the red coloring part. In particular, when an inorganic phosphor is used as the color conversion phosphor, the red color conversion portion is preferably formed in a pattern. As described above, by forming the red color conversion part in a pattern and increasing its surface area, the light scattered and leaked in the red color conversion part can be extracted more efficiently, and the brightness is further improved. It is because it can be made.

In this case, since the incident light to the color conversion layer includes components of blue light and green light, the blue color conversion unit and the green color conversion unit do not need to perform color conversion in principle. And the green color conversion part may not be formed. Therefore, nothing may be formed on the blue colored portion and the green colored portion, but in order to flatten the surface of the color filter substrate for the organic EL element, the transmissive portion having the same thickness as the red conversion portion. May be formed.
This transmissive part transmits incident light. When formed on the blue colored part, it transmits blue light. When formed on the green colored part, it transmits green light. The material is not particularly limited as long as it is, for example, it does not include a color conversion phosphor and can be made of a resin described later. In this case, since the transmissive part does not contain the color conversion phosphor, it is not necessary to be partially formed on each colored part in order to improve luminance. In general, each is formed.

  Furthermore, when the color filter substrate for organic EL elements of the present invention is used for an organic EL display device having a white light emitting layer that emits white light, for example, the incident light to the color conversion layer generally contains components of red light and blue light. There are many. Therefore, the color conversion layer may have at least a green color conversion unit that converts incident light into green light. In this case, for example, as shown in FIG. 4, the green color conversion portion 3G is partially formed on the green coloring portion 2G. In particular, when an inorganic phosphor is used as the color conversion phosphor, the green color conversion portion 3G is preferably formed in a pattern as shown in FIG. 5, for example. As described above, by forming the green color conversion part in a pattern and increasing its surface area, the light scattered and leaked in the green color conversion part can be taken out more efficiently, further improving the brightness. It is because it can be made.

  In this case, since the incident light to the color conversion layer includes components of red light and blue light, the red color conversion unit and the blue color conversion unit do not need to perform color conversion in principle. And the blue color conversion part may not be formed. In this case, nothing may be formed on the red colored portion and the blue colored portion, but in order to flatten the surface of the color filter substrate for the organic EL element, for example, a green color as shown in FIGS. Transmission portions 3R ′ and 3B ′ having the same thickness as the conversion portion 3G may be formed.

  In the above description, the configuration of the color conversion layer corresponding to the type of light emitting light source of the light emitting layer in the organic EL display device to which the color filter substrate for organic EL elements of the present invention is applied has been described. The configuration of the conversion layer is not particularly limited depending on the type of light emitting light source of the light emitting layer, as long as the color conversion layer can perform desired hue correction.

  The green color conversion portion used in the present invention is obtained by dispersing or dissolving a green conversion phosphor that absorbs incident light and emits green fluorescence.

  As the green conversion phosphor, both inorganic phosphors and organic phosphors can be used as described above.

  Specific examples of the inorganic phosphor used as the green conversion phosphor include rare earth complex phosphors disclosed in Japanese Patent Application Laid-Open No. 2004-14335. Examples of rare earth complex phosphors include those having Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, etc. as rare earth metals. The ligand may be either aromatic or non-aromatic, and is preferably a compound represented by the following general formula (1).

Xa- (Lx)-(Ly) _n- (Lz) -Ya (1)

  Here, in the formula, Lx, Ly, and Lz each independently represent an atom having two or more bonds, n represents 0 or 1, and Xa is a substitution having an atom that can coordinate to the adjacent position of Lx Represents a group, and Ya represents a substituent having an atom capable of coordinating at a position adjacent to Lz. Also, any part of Xa and Lx may be condensed with each other to form a ring, any part of Ya and Lz may be condensed with each other to form a ring, and Lx and Lz A ring may be formed by condensation, and at least one aromatic hydrocarbon ring or aromatic heterocyclic ring is present in the molecule. However, Xa- (Lx)-(Ly) n- (Lz) -Ya represents a β-diketone derivative, a β-ketoester derivative, a β-ketoamide derivative, or an oxygen atom of the ketone as a sulfur atom or —N (R201). Or a crown ether, azacrown ether, thiacrown ether, or a crown ether in which the oxygen atom of the crown ether is replaced by any number of sulfur atoms or -N (R201)- There may be no aromatic hydrocarbon ring or aromatic heterocyclic ring. In —N (R201) —, R201 represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

  In the general formula (1), the coordinating atoms represented by Xa and Ya are specifically an oxygen atom, a nitrogen atom, a sulfur atom, a selenium atom, and a tellurium atom. In addition, the atom having two or more bonds represented by Lx, Ly, and Lz is not particularly limited, and examples thereof include a carbon atom, an oxygen atom, a nitrogen atom, a silicon atom, and a titanium atom. .

Specific examples of the rare earth complex phosphor include rare earth complex phosphors containing Ba and Si such as Ba _2-a Eu _a SiO ₄ , or Ba and Mg such as Ba _1-a Eu _a MgAl ₁₀ O _17. And rare earth complex-based phosphors.

Specific examples of inorganic phosphors used as green conversion phosphors include alkaline earth metal thiogallate phosphors disclosed in JP-T-2004-505167, or ZnS-based fluorescence such as ZnS: Tb. Body and yellow-green pigment (for example, FA005 (trade name) manufactured by Shin-Hiroi).
Further, a ZnS-based phosphor such as ZnS: Mn, ZnS: Mn / ZnMgS, a yellow phosphor such as (Y, Gd) 3 Al ₅ O ₁₂ : Ce, or an orange pigment (for example, FA001 (trade name) manufactured by Shinhiro Corporation) It can also be used. These phosphors are not green phosphors, but each contain a green phosphor component, so that color complementarity is possible and can be used.

  On the other hand, specific examples of organic phosphors used as green conversion phosphors include 2,3,5,6-1H, 4H-tetrahydro-8-trifluoromethylquinolidino (9,9a, 1-gh) coumarin. , 3- (2′-benzothiazolyl) -7-diethylaminocoumarin, 3- (2′-benzoimidazolyl) -7-N, N-diethylaminocoumarin, 3- (2′-N-methylbenzimidazolyl) -7-N, N -Coumarin pigments such as diethylaminocoumarin; Coumarin pigments such as Basic Yellow 51; Naphthalimide pigments such as Solvent Yellow 11 or Solvent Yellow 116;

  As said organic fluorescent substance, said pigment | dye and dye are, for example, polymethacrylic acid ester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, alkyd resin, aromatic sulfonamide resin, urea resin, melamine resin, benzoguanamine resin. Alternatively, a fluorescent pigment kneaded in advance in a resin mixture or the like to form a pigment may be used.

  The inorganic phosphor and the organic phosphor described above may be used alone or in combination of two or more in order to adjust the hue of fluorescence.

A specific example of the inorganic phosphor used as the red conversion phosphor is a rare earth complex phosphor. Specific examples of the rare earth complex phosphor include rare earth complex phosphors containing K and W, such as K ₅ Eu _2.5 (WO ₄ ) _6.25 . The other points of the rare earth complex phosphor are the same as in the above case.
Furthermore, specific examples of inorganic phosphors used as red conversion phosphors include ZnS-based phosphors such as ZnS: Mn, ZnS: Mn / ZnMgS, or orange pigments (for example, FA001 (trade name) manufactured by Shinhiro Corporation). It is done.

  On the other hand, specific examples of organic phosphors used as red conversion phosphors include cyanine dyes such as 4-dicyanomethylene-2-methyl-6- (p-dimethylaminostyryl) -4H-pyran; 1-ethyl- Pyridine dyes such as 2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridium-perchlorate; rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, sulforhodamine, basic violet 11, rhodamine dyes such as Basic Red 2; oxazine dyes; and the like.

  Examples of the organic phosphor include the above-mentioned dyes such as polymethacrylic acid ester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, alkyd resin, aromatic sulfonamide resin, urea resin, melamine resin, benzoguanamine resin, and these. Alternatively, a fluorescent pigment kneaded in advance in a resin mixture or the like may be used.

  The inorganic phosphor and the organic phosphor described above may be used alone or in combination of two or more in order to adjust the hue of fluorescence. In general, the conversion efficiency from blue light to red light is low, but the conversion efficiency can be increased by using a mixture of two or more.

  Specific examples of the resin used for each color conversion section include polymethyl methacrylate resin, polyacrylate resin, polycarbonate resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, hydroxyethyl cellulose resin, carboxymethyl cellulose resin, polyvinyl chloride resin, melamine resin, phenol Examples thereof include transparent resins such as resins, alkyd resins, epoxy resins, polyurethane resins, polyester resins, maleic acid resins, and polyamide resins. Specific examples of the resin include ionizing radiation curable resins having reactive vinyl groups such as acrylate, methacrylate, polyvinyl cinnamate, or cyclized rubber (actually, electron beam curable resins). Alternatively, an ultraviolet curable resin, which is often the latter, can be used.

  The ratio of the resin in each color conversion part and each color conversion phosphor is preferably about 100: 0.3 to 100: 5 (mass basis). This is because if the ratio of the color conversion phosphor is too small, sufficient color conversion efficiency may not be obtained, and if the ratio is too large, concentration quenching may occur.

  As a method for forming the color conversion layer, for example, a photolithography method, or the above-described color conversion illuminant and resin are mixed with a solvent, a diluent or an appropriate additive as necessary, and a color conversion layer forming coating solution The printing method which prepares and prints can be mentioned.

2. Colored layer The colored layer used in the present invention is formed in a pattern on a transparent substrate, and usually has a red colored portion, a green colored portion, and a blue colored portion. Each coloring part is regularly arranged corresponding to each pixel, and when the light shielding part is formed, it is provided corresponding to the opening part of the light shielding part.

  Each colored portion used in the present invention is obtained by dispersing or dissolving a colorant such as a pigment or dye of each color in a binder resin.

  Examples of the colorant used in the red coloring part include perylene pigments, lake pigments, azo pigments, quinacridone pigments, anthraquinone pigments, anthracene pigments, and isoindoline pigments. These pigments may be used alone or in combination of two or more.

  Examples of the colorant used in the green coloring portion include phthalocyanine pigments such as halogen polysubstituted phthalocyanine pigments or halogen polysubstituted copper phthalocyanine pigments, triphenylmethane basic dyes, isoindoline pigments, and isoindolinone pigments. Etc. These pigments or dyes may be used alone or in combination of two or more.

  Examples of the colorant used in the blue coloring portion include copper phthalocyanine pigments, anthraquinone pigments, indanthrene pigments, indophenol pigments, cyanine pigments, dioxazine pigments and the like. These pigments may be used alone or in combination of two or more.

  A transparent resin is used as the binder resin used for each colored portion.

  When a printing method is used as a method for forming the colored layer, examples of the binder resin include polymethyl methacrylate resin, polyacrylate resin, polycarbonate resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, hydroxyethyl cellulose resin, carboxymethyl cellulose resin, and polyvinyl chloride resin. Melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, maleic acid resin, polyamide resin and the like.

In addition, when a photolithography method is used as a method for forming the colored layer, the binder resin is usually an ionizing radiation having a reactive vinyl group such as an acrylate, methacrylate, polyvinyl cinnamate, or cyclized rubber. A curable resin is used. Usually, an electron beam curable resin or an ultraviolet curable resin is used.
When an ultraviolet curable resin is used, a photopolymerization initiator is used alone or in combination with a binder resin. Further, when an ultraviolet curable photosensitive resin is used, a sensitizer, a coatability improver, a development improver, a crosslinking agent, a polymerization inhibitor, a plasticizer, a flame retardant, and the like may be used as necessary. .

  As content of a coloring agent, it is preferable to exist in the range of 5 to 50 weight% in each coloring part. The binder resin content is preferably in the range of 30 to 100 parts by weight with respect to 100 parts by weight of the colorant.

  The thickness of such a colored layer is usually about 1 μm to 3 μm.

  The arrangement of the colored portions is not particularly limited as long as the colored portions are arranged on an average when viewed macroscopically, and examples thereof include a stripe arrangement, a mosaic arrangement, and a delta arrangement. Moreover, each coloring part may be formed for every opening part of the light-shielding part.

  As a method for forming the colored layer, a coloring agent is mixed, dispersed or solubilized in a binder resin to prepare a colored layer forming coating solution, and patterning is performed by a photolithography method using the colored layer forming coating solution. The method or the method of patterning by the printing method using the said coating liquid for colored layer formation is used.

3. Transparent base material The transparent base material used for this invention is a support body which supports the color filter substrate for organic EL elements. Moreover, when an organic EL display device is configured using the color filter substrate for organic EL elements of the present invention, it is arranged on the viewer side and is also a support that supports the entire organic EL display device.

  As the transparent substrate, for example, an inorganic plate-like transparent substrate such as glass or quartz glass, an organic (for example, synthetic resin) plate-like transparent substrate such as acrylic resin, or a synthetic resin-made transparent film-like substrate Materials can be used. A very thin glass can also be used as the transparent film substrate.

  Moreover, as a transparent base material, it is preferable that the smoothness of the surface at the side which forms a colored layer, a color conversion layer, etc. is high. Specifically, it is preferable to use one having an average surface roughness (Ra) of 0.5 nm to 3.0 nm (5 μm □ region).

  Specific examples of the synthetic resin constituting the transparent substrate include polycarbonate resin, polyarylate resin, polyethersulfone resin, acrylic resin such as methyl methacrylate resin, cellulose resin such as triacetyl cellulose resin, epoxy resin, or cyclic Examples thereof include olefin resins and cyclic olefin copolymer resins.

4). Light Shielding Part In the present invention, a light shielding part (also referred to as a black matrix) may be formed between the colored layers on the transparent substrate. The light shielding section is provided to partition the light emitting area for each pixel, prevent reflection of external light at the boundary between the light emitting areas, and increase the contrast of images and videos. Therefore, the light shielding portion is not necessarily provided, but it is preferable that the light shielding portion is formed in order to form the colored layer or the like corresponding to the opening of the light shielding portion, in addition to improving the contrast. Further, when the organic EL display device is formed using the color filter substrate for the organic EL element of the present invention, the light shielding portion is formed because the light emitting layer and the like are formed corresponding to the opening of the light shielding portion. It is preferable.

  The light-shielding portion is usually formed in a black line shape, and is formed in a pattern shape having openings such as a matrix shape or a stripe shape. When an organic EL display device is formed using the color filter substrate for organic EL elements of the present invention, light emission from the light emitting layer reaches the observer side via the opening of the light shielding portion.

  The light-shielding part used in the present invention may be insulating or non-insulating, but preferably has insulating properties. If the light-shielding part has an insulating property, even when the light-shielding part and the transparent electrode layer are in contact with each other when the organic EL element color filter substrate of the present invention is used to form an organic EL display device, the light-shielding part is light-shielded. This is because it is possible to avoid electrical conduction between the portion and the transparent electrode layer.

  Examples of the material for forming the light-shielding portion having insulating properties include a resin composition containing a black colorant such as carbon black. Examples of the resin used in the resin composition include ionizing radiation curable resins having reactive vinyl groups such as acrylate-based, methacrylate-based, polyvinyl cinnamate, or cyclized rubber, particularly electron beam curable resins or An ultraviolet curable resin can be used. Also, for example, polymethyl methacrylate resin, polyacrylate resin, polycarbonate resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, hydroxyethyl cellulose resin, carboxymethyl cellulose resin, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin Examples thereof include a polyester resin, a maleic acid resin, and a polyamide resin.

Moreover, as a formation material of the light shielding part which does not have insulation, metals or metal oxides, such as chromium, are mentioned, for example. At this time, the light-shielding part having no insulating property may be a laminate of two layers of a CrO _x film (x is an arbitrary number) and a Cr film, and a CrO _x film with a further reduced reflectance. (X is an arbitrary number), a CrN _y film (y is an arbitrary number), and a three-layered Cr film may be laminated.

  As a method for forming a light-shielding portion having insulating properties, a method of applying the above resin composition on a substrate and patterning it by a photolithography method can be used. Also, a printing method or the like can be used.

  As a method for forming a light-shielding portion having no insulating property, a method of forming a thin film by a vapor deposition method, an ion plating method, a sputtering method, or the like, and patterning using a photolithography method can be used. Further, an electroless plating method or the like can also be used.

  The film thickness of the light-shielding portion is about 0.2 μm to 0.4 μm when formed by vapor deposition, ion plating, sputtering, or the like, and is about 0.2 μm when formed by coating or printing. It is about 5 μm to 2 μm.

5. Flattening layer In the present invention, a flattening layer may be formed on the color conversion layer. This flattening layer has a role of protecting the colored layer and the color conversion layer, and when the thickness of the colored layer and the color conversion layer is not constant, the surface of the layer is smoothed to obtain a flat surface. When used in a display device, it is provided for the purpose of reducing the influence when forming a transparent electrode layer or the like. In addition, when there is a level difference (unevenness) due to the configuration of the color layer or the color conversion layer, the leveling layer eliminates the level difference to achieve leveling, and forms the organic EL layer at the time of manufacturing the organic EL display device. It is a flattening action that prevents the occurrence of uneven thickness.

  As a material for forming the planarization layer used in the present invention, a transparent resin can be used. Specifically, a photocurable resin or a thermosetting resin having an acrylate-based or methacrylate-based reactive vinyl group can be used. In addition, as the transparent resin, polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl chloride resin, melamine resin, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin A maleic acid resin, a polyamide resin, or the like can be used.

  Moreover, the planarization layer in this invention may have light-scattering property. By the light-scattering property of the flattening layer, the light converted by the color conversion layer is prevented from leaking in the direction horizontal to the transparent substrate, and the direction perpendicular to the transparent substrate (observer side) This is because light can be extracted efficiently.

  In order to impart a light scattering function to the planarizing layer, the planarizing layer may contain light scattering fine particles. The light scattering fine particles used in the present invention are fine particles having a light scattering action. Preferred examples of the light scattering fine particles include inorganic substances such as silicon oxide, aluminum oxide and barium sulfate, acrylic resins, divinylbenzene resins, benzoguanamine resins, styrene resins, melamine resins, acrylic-styrene resins, polycarbonates. Fine particles of organic substances such as resin, polyethylene resin, polyvinyl chloride resin, etc., or fine particles of a mixture of two or more of these can be mentioned. Among these, melamine-based resin, benzoguanamine-based resin, and mixed resin and copolymer fine particles thereof are preferable in terms of transparency and durability.

  The average particle diameter of the light-scattering fine particles is preferably about 0.1 to 5.0 μm, more preferably 0.1 to 4.0 μm, and still more preferably 0.1 to 2.0 μm. It is. This is because a sufficient light scattering effect can be obtained when the average particle diameter is in the above range.

  The light scattering fine particles are preferably spherical in order to increase the light scattering effect.

  As the method for forming the flattening layer, when the flattening layer forming coating liquid containing the transparent resin is a liquid, it is applied by spin coating, roll coating, cast coating, etc. In the case of a curable resin, there may be mentioned a method in which the resin is thermally cured as necessary after irradiation with ultraviolet rays, and in the case of a thermosetting resin, it can be directly heat-cured after film formation. Moreover, when the transparent resin mentioned above is shape | molded in the film form, a planarization layer can be formed by sticking directly or via an adhesive.

  The thickness of such a planarization layer can be set to about 1 to 7 μm, for example.

6). Gas Barrier Layer In the present invention, a gas barrier layer may be formed on the color conversion layer. For example, as shown in FIG. 6, when the planarization layer 5 is formed on the color conversion layer 3, the gas barrier layer 6 is formed on the planarization layer 5. When this gas barrier layer is used in an organic EL display device, it blocks the permeation of water vapor or oxygen from the color filter substrate for organic EL elements or the desorbed gas from a colored layer or color conversion layer to the organic EL layer. It is provided for this purpose.

  The gas barrier layer used in the present invention is not particularly limited as long as it can exhibit gas barrier properties against gases such as water vapor, oxygen, and desorption gas. For example, a transparent inorganic film, a transparent resin A film or an organic-inorganic hybrid film is used. Among these, a transparent inorganic film is preferable because of its high gas barrier property.

  The material used for the transparent inorganic film is not particularly limited as long as it can exhibit gas barrier properties. For example, oxides such as aluminum oxide, silicon oxide, and magnesium oxide; nitriding such as silicon nitride A nitride oxide such as silicon nitride oxide; Among these, silicon nitride oxide is preferable because pinholes and protrusions hardly occur and the gas barrier property is high.

  Further, the gas barrier layer may be a single layer or a multilayer. For example, when the gas barrier layer is a multilayer in which a plurality of silicon nitride oxide films are stacked, the gas barrier property can be further improved. Moreover, when a gas barrier layer is a multilayer, you may use a different material for each layer, respectively.

  The thickness of the gas barrier layer is not particularly limited, and differs depending on the base material to be used, the type of material used for the gas barrier layer, or whether the gas barrier layer is a single layer or a multilayer, and cannot be specified unconditionally. However, it is generally about 20 nm to 2 μm for the entire gas barrier layer. This is because if the thickness of the gas barrier layer is too thin, the gas barrier property may be insufficient, and if the thickness of the gas barrier layer is too thick, a phenomenon such as a crack due to the film stress of the thin film tends to occur.

  When the gas barrier layer is a transparent inorganic film, the method for forming the transparent inorganic film is not particularly limited as long as it is a film forming method that can be formed in a vacuum state. For example, sputtering, chemical vapor deposition ( CVD) method, ion plating method, vacuum deposition method such as electron beam (EB) deposition method and resistance heating method, laser ablation method and the like. Among these, considering the productivity of the color filter substrate for an organic EL element, the sputtering method, the ion plating method, and the CVD method are preferable, and the sputtering method is more preferable. This is because by using the sputtering method, a gas barrier layer having high productivity and excellent quality stability can be formed.

7). Method for Manufacturing Color Filter Substrate for Organic EL Element Hereinafter, an example of a method for manufacturing a color filter substrate for an organic EL element of the present invention will be described.
First, a black matrix is formed by depositing a metal such as chromium or a metal oxide such as chromium oxide on the entire surface of the transparent substrate and patterning it using a photolithography method. Next, a red colored portion forming coating solution in which a red colorant is dispersed or dissolved in a binder resin is applied on a transparent base material on which a black matrix is formed, and then patterned by using a photolithography method. A colored part is formed. A green colored portion and a blue colored portion are formed by the same procedure.
Next, a green color conversion part is formed by applying a green color conversion part forming coating liquid in which a green conversion phosphor is dispersed or dissolved in a resin and patterning the green color part using a photolithography method. . At this time, the green color conversion part is formed in a pattern on the green coloring part.
And a planarization layer is formed so that a green color conversion part and each coloring part may be covered as needed.
In this way, a color filter substrate for an organic EL element can be produced.

B. Organic EL Display Device Next, the organic EL display device of the present invention will be described. The organic EL display device of the present invention includes the above-described color filter substrate for organic EL elements, the transparent electrode layer formed on the color conversion layer side surface of the color filter substrate for organic EL elements, and the transparent electrode layer. The organic EL layer is formed and includes at least a light emitting layer, and a counter electrode layer formed on the organic EL layer.

  Since the organic EL display device of the present invention uses the above-described color filter substrate for an organic EL element, it is possible to efficiently extract light scattered and leaked in the color conversion layer and to improve luminance. .

FIG. 6 is a schematic cross-sectional view showing an example of the organic EL display device of the present invention. In FIG. 6, the organic EL element color filter substrate 10 is formed on the transparent base material 1 with a colored layer composed of the three primary colored portions 2R, 2G, and 2B, and a green color conversion formed on the green colored portion 2G. A color conversion layer having a portion 3G, a light shielding portion 4 is formed between the colored portions 2R, 2G, and 2B, and a planarizing layer 5 is formed so as to cover the colored layer and the color conversion layer. A gas barrier layer 6 is formed thereon. Further, transmissive portions 3R ′ and 3B ′ that transmit incident light are formed on the red colored portion 2R and the blue colored portion 2B, respectively. In the organic EL display device 20 of the present invention, a transparent electrode layer 11, an organic EL layer 12 including a light emitting layer, and a counter electrode layer 13 are formed on the gas barrier layer 6 of the color filter substrate 10 for organic EL elements. An insulating layer 14 is formed between the transparent electrode layers 11 on the gas barrier layer 6, and a partition wall (cathode separator) 15 is formed thereon.
Hereinafter, each configuration of the organic EL display device of the present invention will be described.

1. Organic EL Layer The organic EL layer used in the present invention is composed of one or more organic layers including at least a light emitting layer. That is, the organic EL layer is a layer including at least a light emitting layer, and the layer configuration is a layer having one or more organic layers. Usually, when an organic EL layer is formed by a wet method by coating, it is often difficult to stack a large number of layers in relation to a solvent, so that it is often formed of one or two organic layers. However, it is possible to further increase the number of layers by devising an organic material so that the solubility in a solvent is different or by combining a vacuum deposition method.

Examples of the organic layer formed in the organic EL layer other than the light emitting layer include charge injection layers such as a hole injection layer and an electron injection layer. Furthermore, examples of the other organic layers include a charge transport layer such as a hole transport layer that transports holes to the light-emitting layer and an electron transport layer that transports electrons to the light-emitting layer. In many cases, it is formed integrally with the charge injection layer by imparting a charge transporting function. In addition, as an organic layer formed in the organic EL layer, it prevents holes or electrons from penetrating like a carrier block layer and further prevents diffusion of excitons and confines excitons in the light emitting layer. And a layer for increasing the recombination efficiency.
Hereinafter, each structure of such an organic EL layer will be described.

(1) Light emitting layer The light emitting layer used in the present invention has a function of emitting light by providing a recombination field of electrons and holes. The light emitting layer may be a white light emitting layer that emits white light or a blue light emitting layer that emits blue light.

The blue light-emitting layer usually contains a blue light-emitting body that emits blue light. A general thing can be used as a blue light-emitting body. For example, JP-A-7-122364 and JP-disclosed in Japanese Patent Laid-Open No. _{8-134440, SrGa 2 S 4: Ce} , CaGa 2 S 4: Ce, BaAl 2 S 4: Chiogaredo or thioaluminate such as Eu A blue light emitter excellent in color purity of the system is preferably used. Specific examples of the blue light emitters include fluorescent whitening agents such as benzothiazole, benzimidazole, and benzoxazole exemplified in JP-A-8-279394, and JP-A-63-295695. Metal chelated oxinoid compounds disclosed in US Pat. No. 5,258,793, styrylbenzene compounds disclosed in European Patent No. 0319881, European Patent No. 0373582, and distyryl disclosed in JP-A-2-252793. Examples thereof include pyrazine derivatives or aromatic dimethylidin compounds disclosed in European Patent No. 0388768 and JP-A-3-231970.

  Examples of the benzothiazole fluorescent whitening agent include 2-2 ′-(p-phenylenedivinylene) -bisbenzothiazole. Examples of the benzimidazole-based optical brightener include 2- [2- [4- (2-benzimidazolyl) phenyl] vinyl] benzimidazole or 2- [2- (4-carboxyphenyl) vinyl] benzimidazole. Is mentioned. Examples of the benzoxazole-based optical brightener include 2,5-bis (5,7-di-t-pentyl-2-benzoxazolyl) -1,3,4-thiadiazole, 4,4′-. Bis (5,7-t-pentyl-2-benzoxazolyl) stilbene, 2- [2- (4-chlorophenyl) vinyl] naphtho [1,2-d] oxazole, and the like can be given.

  Examples of the metal chelated oxinoid compound include 8-hydroxyquinoline metal complexes such as tris (8-quinolinol) aluminum, bis (8-quinolinol) magnesium, bis (benzo [f] -8-quinolinol) zinc, Alternatively, dilithium epintridione and the like can be mentioned. Examples of the styrylbenzene compound include 1,4-bis (2-methylstyryl) benzene, 1,4-bis (3-methylstyryl) benzene, 1,4-bis (4-methylstyryl) benzene, and distyryl. Benzene, 1,4-bis (2-ethylstyryl) benzene, 1,4-bis (3-ethylstyryl) benzene, 1,4-bis (2-methylstyryl) -2-methylbenzene, or 1,4- Examples thereof include bis (2-methylstyryl) -2-ethylbenzene.

  Further, examples of the distyrylpyrazine derivative include 2,5-bis (4-methylstyryl) pyrazine, 2,5-bis (4-ethylstyryl) pyrazine, and 2,5-bis [2- (1-naphthyl). ) Vinyl] pyrazine, 2,5-bis (4-methoxystyryl) pyrazine, 2,5-bis [2- (4-biphenyl) vinyl] pyrazine, or 2,5-bis [2- (1-pyrenyl) vinyl ] A pyrazine etc. or those derivatives are mentioned. Examples of the aromatic dimethylidin compounds include 1,4-phenylene dimethylidin, 4,4-phenylene dimethylidin, 2,5-xylene dimethylidin, 2,6-naphthylene dimethylidin, 1,4. -Biphenylene dimethylidin, 1,4-p-terephenylene dimethylidin, 9,10-anthracenediyldimethylidin, 4,4'-bis (2,2-di-t-butylphenylvinyl) biphenyl, Alternatively, 4,4′-bis (2,2-diphenylvinyl) biphenyl and the like, or derivatives thereof can be exemplified.

Specific examples of the blue light emitter include compounds represented by the general formula (Rs-Q) _2- AL-OL disclosed in JP-A-5-258862. Here, in the general formula, L is a hydrocarbon having 6 to 24 carbon atoms including a benzene ring, OL is a phenylate ligand, Q is a substituted 8-quinolinolato ligand, and Rs is It represents an 8-quinolinolato ring substituent selected so as to sterically hinder the bonding of two or more substituted 8-quinolinolato ligands to an aluminum atom. Specifically, bis (2-methyl-8-quinolinolato) (para-phenylphenolate) aluminum (III), bis (2-methyl-8-quinolinolato) (1-naphtholato) aluminum (III), etc. are exemplified. can do.

  On the other hand, white light emission by the white light emitting layer can be obtained by superimposing light emitted from a plurality of light emitters. The white light emitting layer in the present invention may be one that obtains white light emission by superimposing two-color light emission of two kinds of light emitters having a predetermined fluorescence peak wavelength, and three kinds of light emission layers having a predetermined fluorescence peak wavelength. White light emission may be obtained by superimposing three-color light emission of the light emitter. Especially, it is preferable that a white light emitting layer shows white light emission with few components of green light. For example, by forming the green color conversion part partially on the green coloring part, a good green display can be obtained and the brightness of the green light can be improved. This is because an EL display device can be obtained.

In the present invention, the white light-emitting layer preferably emits white light by a so-called two-wavelength light source that obtains white light emission by superimposing two-color light emission of two kinds of light emitters having a predetermined fluorescence peak wavelength. . In particular, the white light emitting layer preferably contains a blue light emitter and a small amount of a red light emitter and emits white light from a two-wavelength light source. The white light emission obtained by such a white light emitting layer contains almost no green light component. However, as described above, for example, by forming a green color conversion part partially on the green coloring part, a good green color can be obtained. This is because a display can be obtained and the luminance of green light can be improved, so that an organic EL display device excellent in the balance of the color characteristics of the three primary colors can be obtained.
Note that the “two-wavelength light source” here includes not only complete two-wavelength light emission but also main light emission having two wavelengths.

  The blue phosphor used for the white light emitting layer preferably has a fluorescence peak wavelength of 380 nm or more and less than 480 nm, more preferably 420 nm or more and less than 475 nm. As such a blue light emitter, among the compounds described in, for example, JP-A-3-231970, International Publication No. WO92 / 05131 or JP-A-7-26254, the above-mentioned fluorescence condition is satisfied. To do. Specific examples include compounds described in JP-A-6-207170.

  Moreover, it is preferable that the red light-emitting body used for a white light emitting layer has a fluorescence peak wavelength of 575 nm or more and 650 nm or less, and more preferably 580 nm or more and 620 nm or less. Examples of such red light emitters include dicyanomethylene pyran derivatives, dicyanomethylene thiopyran derivatives, fluorescein derivatives, and perylene derivatives used as red starting laser dyes described in European Patent Publication No. 0283381. The content of the red light emitter is set in a range in which concentration quenching does not occur.

  Although it does not specifically limit as thickness of a light emitting layer, For example, it can be set as about 5 nm-5 micrometers.

  The method for forming the light emitting layer is not particularly limited as long as it is a method capable of high-definition patterning. For example, vapor deposition method, printing method, inkjet method, spin coating method, casting method, dipping method, bar coating method, blade coating method, roll coating method, gravure coating method, flexographic printing method, spray coating method, and self-assembly method (Alternate adsorption method, self-assembled monolayer method) and the like. Among these, it is preferable to use a vapor deposition method, a spin coating method, and an ink jet method. Further, when the light emitting layer is patterned, it may be separately applied or vapor deposited by a masking method, or a partition may be formed between the light emitting layers.

(2) Hole injection layer In the present invention, a hole injection layer may be formed between the light emitting layer and the anode (transparent electrode layer or counter electrode layer). This is because by providing the hole injection layer, the injection of holes into the light emitting layer is stabilized and the light emission efficiency can be increased.

  As a constituent material of the hole injection layer used in the present invention, a material generally used for a hole injection layer of an organic EL element can be used. The constituent material of the hole injection layer may be any material that has either a hole injection property or an electron barrier property, and may be an organic material or an inorganic material.

  Specifically, the constituent material of the hole injection layer includes triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives. And styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, polysilane-based, aniline-based copolymers, or conductive polymer oligomers such as thiophene oligomers. Furthermore, examples of the constituent material of the hole injection layer include porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds.

  Examples of the porphyrin compound include porphine, 1,10,15,20-tetraphenyl-21H, 23H-porphine copper (II), aluminum phthalocyanine chloride, copper octamethylphthalocyanine, and the like.

  Examples of the aromatic tertiary amine compound include N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl, N, N′-diphenyl-N, N′-bis- ( 3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine, 4- (di-p-tolylamino) -4 ′-[4 (di-p-tolylamino) styryl] stilbene, 3- Methoxy-4'-N, N-diphenylaminostilbenzene, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl, or 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine and the like.

  The thickness of such a hole injection layer is not particularly limited, but can be, for example, about 5 nm to 5 μm.

(3) Electron Injection Layer In the present invention, an electron injection layer may be formed between the light emitting layer and the cathode (transparent electrode layer or counter electrode layer). This is because by providing the electron injection layer, the injection of electrons into the light emitting layer is stabilized and the light emission efficiency can be increased.

  As the constituent material of the electron injection layer used in the present invention, for example, nitro-substituted fluorene derivatives, anthraquinodimethane derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, carbodiimide, Fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, or thiazole derivatives in which the oxygen atom of the oxadiazole ring of the oxadiazole derivative is substituted with a sulfur atom, quinoxaline known as an electron withdrawing group Examples thereof include quinoxaline derivatives having a ring, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum, phthalocyanine, metal phthalocyanine, or distyrylpyrazine derivatives.

  Although it does not specifically limit as thickness of the said electron injection layer, For example, it can be set as about 5 nm-5 micrometers.

2. Transparent electrode layer The transparent electrode layer used in the present invention is for applying a voltage to the organic EL layer sandwiched between the counter electrode layer and causing light emission at a predetermined position. This transparent electrode layer is formed on the color conversion layer side surface of the color filter substrate for the organic EL element described above. For example, as shown in FIG. It is formed in a stripe shape having a width corresponding to the width. In this case, the pitch of the striped transparent electrode layer 11 is the same as the pitch of the openings of the light shielding portion 4.

  The transparent electrode layer in the present invention is usually composed of a metal oxide thin film having transparency and conductivity. Examples of such a metal oxide include indium tin oxide (ITO), indium oxide, zinc oxide, and stannic oxide.

  As a method for forming such a transparent electrode layer, for example, a method of forming a thin film of metal oxide by, for example, vapor deposition or sputtering and then patterning by photolithography is preferably used.

3. Counter Electrode Layer The counter electrode layer used in the present invention forms the other electrode for causing the organic EL layer to emit light, and is an electrode having a charge opposite to that of the transparent electrode layer. This counter electrode layer is formed on the organic EL layer.

The counter electrode layer in the present invention is usually composed of a metal, an alloy, or a mixture thereof having a work function as small as about 4 eV or less. Specifically, sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, indium, Or a lithium / aluminum mixture, a rare earth metal, etc. can be illustrated. More preferable examples include a magnesium / silver mixture, a magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, or a lithium / aluminum mixture.

The counter electrode layer preferably has a sheet resistance of several hundred Ω / cm or less.
The thickness of the counter electrode layer is preferably about 10 nm to 1 μm, more preferably about 50 to 200 nm.

  As a method for forming such a counter electrode layer, a method of forming a thin film by an evaporation method or a sputtering method and then patterning by a photolithography method is preferably used.

4). Others In the present invention, an insulating layer may be formed between the striped transparent electrode layers so as to correspond to the light shielding portion.

  In addition, a partition wall functioning as a mask for forming a light emitting layer or the like may be formed on the insulating layer. As a material for forming the partition wall, for example, a photocurable resin such as a photosensitive polyimide resin or an acrylic resin, a thermosetting resin, an inorganic material, or the like can be used. In this case, you may perform the process which changes the surface energy (wetting property) of a partition part.

  The driving method of the organic EL display device of the present invention may be either a passive matrix or an active matrix.

  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 using examples and comparative examples.
[Example 1]
(Formation of black matrix)
As a transparent substrate, soda glass (manufactured by Central Glass Co., Ltd.) having a size of 150 mm × 150 mm and a thickness of 0.7 mm was prepared. A thin film (thickness 0.2 μm) of oxynitride composite chromium was formed on the entire surface of one side of the transparent substrate by sputtering. A photosensitive resist is applied on the oxynitride composite chrome thin film, mask exposure, development, and etching of the oxynitride composite chrome thin film are sequentially performed, and an 80 μm × 280 μm rectangular opening has a length of 100 μm in the short side direction. A black matrix arranged in a matrix at a pitch of 300 μm in the long side direction was formed.

(Formation of colored layer)
A coating solution for forming colored portions of red, green and blue was prepared. As a red colorant, a condensed azo pigment (manufactured by Ciba Specialty Chemicals, Chromophthalred BRN), as a green colorant, a phthalocyanine green pigment (manufactured by Toyo Ink Manufacturing Co., Ltd., Lionol Green 2Y-301), As the blue colorant, anthraquinone pigments (manufactured by Ciba Specialty Chemicals, Chromophthal Blue A3R) were used. Moreover, polyvinyl alcohol (10% aqueous solution) was used as the binder resin. Each colorant was blended at a ratio of 1 part by weight with respect to 10 parts by weight of the polyvinyl alcohol aqueous solution, and sufficiently mixed and dispersed. Furthermore, 1 part by weight of ammonium dichromate was added as a cross-linking agent to 100 parts by weight of the obtained solution to obtain each colored portion forming coating solution.

  Each colored part was formed using the above-described coating liquid for forming colored parts. That is, on the transparent base material on which the black matrix was formed, a red colored portion forming coating solution was applied by spin coating, and prebaked at 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 is performed at 200 ° C. for 60 minutes to synchronize with the black matrix pattern, and the stripe-shaped red colored portion having a width of 85 μm and a thickness of 1.5 μm is arranged in the width direction of the short side of the opening portion of the black matrix. It formed so that it might become. Thereafter, the green colored portion forming coating solution and the blue colored portion forming coating solution were sequentially used to form striped green colored portions and blue colored portions. This formed a colored layer in which the colored portions of the three primary colors were repeatedly arranged in the width direction.

(Formation of color conversion layer)
After the black matrix and the colored layer are formed, a transparent portion forming coating solution (manufactured by Fuji Hunt Electronics Technology Co., Ltd., transparent photosensitive resin composition, product name: Color Mosaic CB-701) is applied by spin coating. This was applied and prebaked at 100 ° C. for 5 minutes. Next, after patterning by photolithography, post baking was performed at 200 ° C. for 60 minutes. As a result, stripe-shaped transmission portions having a width of 85 μm and a thickness of 2.5 μm were formed on the blue coloring portion and the red coloring portion, respectively.

  Next, an alkali-soluble negative photosensitive resist in which a green conversion phosphor (manufactured by Aldrich Co., Ltd., coumarin 6) is dispersed is used as a conversion green color portion forming coating solution, and the procedure shown in FIG. As described above, a striped green color conversion portion 3G having a width of 10 μm, a gap of 5 μm, and a thickness of 2.5 μm was formed on the green coloring portion 2G.

(Formation of planarization layer)
Next, a flattening layer forming coating solution is prepared by diluting an acrylate-based photocurable resin (manufactured by Nippon Steel Chemical Co., Ltd., trade name: V-259PA / PH5) with propylene glycol monomethyl ether acetate. The coating liquid for forming a chemical layer is applied by spin coating on the color conversion layer, prebaked at 120 ° C. for 5 minutes, and then exposed to ultraviolet rays so that the irradiation dose is 300 mJ. After the exposure, post-baking was performed at 200 ° C. for 60 minutes to form a transparent flattening layer having a thickness of 2 μm so as to cover the entire colored layer and color conversion layer.

(Formation of transparent electrode layer)
Next, an indium tin oxide (ITO) electrode film having a thickness of 150 nm is formed on the planarizing layer by ion plating, a photosensitive resist is applied on the ITO electrode film, mask exposure, development, and ITO electrode film Etching was performed to form a transparent electrode layer. This transparent electrode layer is a striped pattern with a width of 80 μm formed so as to run on the flattening layer from the transparent substrate, and is located on each colored portion of the colored layer on the color conversion layer. It was.

(Formation of insulating layer and partition wall)
After applying a coating solution for forming an insulating layer obtained by diluting a norbornene-based resin having an average molecular weight of about 100,000 (manufactured by JSR Co., Ltd., ARTON) with toluene and covering the transparent electrode layer by spin coating, The insulating film (thickness 1 μm) was formed by baking (100 ° C., 30 minutes). 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 arranged so that the opening of the insulating layer was positioned in the opening of the black matrix, and the opening of the insulating layer was a rectangular shape having a size of 90 μm × 290 μm larger than the opening of the black matrix.

  Next, a partition wall coating (manufactured by Nippon Zeon Co., Ltd., photoresist, ZPN1100) was applied to the entire surface so as to cover the insulating layer by spin coating, and prebaked (70 ° C., 30 minutes). Then, it exposed using the predetermined | prescribed photomask, developed with the developing solution (Nippon ZEON Co., Ltd. make, ZTMA-100), and then post-baked (100 degreeC, 30 minutes). Thereby, the partition part was formed on the insulating layer. The partition wall had a shape with a height of 10 μm, a lower portion (insulating layer side) width of 15 μm, and an upper portion width of 26 μm.

(Formation of white organic EL layer)
Next, using the partition wall as a mask, an organic EL layer composed of a hole injection layer and a white light emitting layer was formed by vacuum deposition.
That is, first, N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine is provided with an opening corresponding to the image display area. By depositing a film to 60 nm through a photomask and forming a film, the partition walls become a mask pattern, and the hole injection layer forming material passes only between the partition walls to form a hole injection layer on the transparent electrode layer. Formed.
Similarly, 4,4′-bis (2,2′-diphenylvinyl) biphenyl (fluorescence peak wavelength: 465 nm (solid)) was deposited to 40 nm to form a film. At the same time, a small amount of rubrene (manufactured by Aldrich Co., Ltd., fluorescence peak wavelength: 585 nm (dimethylformamide 0.1 wt% solution)) 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 stripe pattern having a width of 280 μm.

(Formation of counter electrode layer)
Next, magnesium and silver are simultaneously deposited by vacuum deposition (magnesium deposition rate) on the region where the partition wall is formed through a photomask having a predetermined opening wider than the image display region. = 1.3 to 1.4 nm / second, silver deposition rate = 0.1 nm / second). Thereby, the partition electrode portion was used as a mask to form a 200 nm-thick counter electrode layer made of a magnesium / silver compound on the organic EL layer. The counter electrode layer was present on the white organic EL layer as a stripe pattern having a width of 280 μm.
Thus, an organic EL display device was produced.

[Comparative Example 1]
An organic EL display device was produced in the same manner as in Example 1 except that the color conversion layer was not formed in Example 1.

[Evaluation]
A transparent electrode layer is formed by applying a voltage of DC 8.5 V at a constant current density of 10 mA / cm ² to the transparent electrode layer and the counter electrode layer of the organic EL display device of Example 1 and Comparative Example 1 and driving them continuously. The white light emitting layer at a desired portion where the counter electrode layer and the counter electrode layer intersect was caused to emit light. The CIE chromaticity coordinates (JIS Z 8701) are used for light emission of each color observed on the opposite surface side of the transparent substrate after color conversion in the color conversion layer or transmission as it is and color correction in the colored layer. It was measured. As a result, in the organic EL display device of Comparative Example 1, green light emission of x = 0.264 and y = 0.534 was confirmed in the CIE chromaticity coordinates, whereas in the organic EL display device of Example 1, the CIE color was confirmed. Green light emission of x = 0.291 and y = 0.564 was confirmed in degree coordinates. Further, comparing the luminance of green light emission, the luminance of the organic EL display device of Example 1 was improved by 5% as compared with the organic EL display device of Comparative Example 1. Thus, the organic EL display device of Example 1 was capable of displaying three primary colors with high luminance and high color purity.

[Example 2]
In Example 1, an organic EL display device was produced in the same manner as in Example 1 except that a colored layer was formed as shown below.
(Formation of colored layer)
A coating solution for forming colored portions of red, green and blue was prepared. As a red colorant, a condensed azo pigment (manufactured by Ciba Specialty Chemicals, Chromophthalred BRN), as a green colorant, a phthalocyanine green pigment (manufactured by Toyo Ink Manufacturing Co., Ltd., Lionol Green 2Y-301), As the blue colorant, anthraquinone pigments (manufactured by Ciba Specialty Chemicals, Chromophthal Blue A3R) were used. As the binder resin, an acrylic UV curable resin composition (acrylic UV curable resin 20%, acrylic UV curable resin monomer 20%, additive 5%, propylene glycol monomethyl ether acetate (PGMEA) 55%) Was used. For each 10 parts of the acrylic UV curable resin composition, each colorant is blended in a ratio of 1 part (all parts are based on mass), and sufficiently mixed and dispersed. Obtained.

Each colored part was formed using the above-described coating liquid for forming colored parts. That is, on the transparent substrate on which the black matrix was formed, a red colored portion forming coating solution was applied by a spin coating method, and prebaked at 120 ° C. for 2 minutes. Then, it exposed using the photomask (integrated exposure amount 300mJ / cm < ² >), and developed with the developing solution (0.05% KOH aqueous solution). Next, post-baking is performed at 230 ° C. for 60 minutes to synchronize with the pattern of the black matrix, and the striped red colored portion having a width of 85 μm and a thickness of 1.5 μm is arranged in the direction of the short side of the opening of the black matrix. It formed so that it might become. Thereafter, the green colored portion forming coating solution and the blue colored portion forming coating solution were sequentially used to form striped green colored portions and blue colored portions. This formed a colored layer in which the colored portions of the three primary colors were repeatedly arranged in the width direction.

(Evaluation)
Similar to the organic EL display device of Example 1, the organic EL display device of Example 2 was capable of displaying three primary colors with high luminance and high color purity.

It is a schematic sectional drawing which shows an example of the color filter substrate for organic EL elements of this invention. It is a schematic sectional drawing which shows the other example of the color filter substrate for organic EL elements of this invention. It is a schematic sectional drawing which shows the other example of the color filter substrate for organic EL elements of this invention. It is a schematic sectional drawing which shows the other example of the color filter substrate for organic EL elements of this invention. It is a schematic sectional drawing which shows the other example of the color filter substrate for organic EL elements of this invention. It is a schematic sectional drawing which shows an example of the organic electroluminescent display apparatus of this invention. 6 is an explanatory diagram for explaining a green color conversion unit in Embodiment 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent base material 2 ... Colored layer 2R ... Red colored part 2G ... Green colored part 2B ... Blue colored part 3 ... Color conversion layer 3R ... Red color conversion part 3G ... Green color conversion part 3R ', 3B' ... Transmission part 4 DESCRIPTION OF SYMBOLS ... Shading part 5 ... Flattening layer 6 ... Gas barrier layer 10 ... Color filter substrate for organic EL elements 11 ... Transparent electrode layer 12 ... Organic EL layer 13 ... Counter electrode layer 20 ... Organic EL display apparatus

Claims (8)

A transparent substrate, a colored layer formed on the transparent substrate, a color conversion layer partially formed on the colored layer, and a planarization layer formed on the color conversion layer The color conversion substrate for an organic electroluminescence element used by arranging the color conversion layer side on the organic electroluminescence element side ,
The planarization layer has light scattering properties;
When an inorganic phosphor is used for the color conversion layer, the occupation area ratio of the color conversion layer is in the range of 20 to 90, where the area of the colored layer is 100,
When an organic phosphor is used for the color conversion layer, the occupation area ratio of the color conversion layer is within a range of 58.82 to 95, where the area of the colored layer is 100. Color filter substrate.   The color filter substrate for an organic electroluminescent element according to claim 1, wherein a plurality of the color conversion layers are partially formed on the colored layer.   The colored layer has a red colored portion, a green colored portion, and a blue colored portion, and the color conversion layer is partially formed on the red colored portion and the green colored portion. The color filter substrate for an organic electroluminescent element according to claim 1, wherein the color filter substrate has at least one of the green color conversion portions formed in a typical manner.   4. The color filter substrate for an organic electroluminescence element according to claim 3, wherein a red color conversion part is not formed on the red coloring part. A color filter substrate for an organic electroluminescence device according to any one of claims of claims 1 to 4, characterized in that the gas barrier layer is formed on the color conversion layer. The color filter substrate for an organic electroluminescent element according to any one of claims 1 to 5 , wherein a light-shielding portion is formed between the colored layers on the transparent substrate. Organic color filter substrate for an electroluminescent device, a transparent electrode layer formed on the color conversion layer side surface of the color filter substrate for the organic electroluminescent device according to any one of claims of claims 1 to 6 And an organic electroluminescence layer formed on the transparent electrode layer and including at least a light emitting layer, and a counter electrode layer formed on the organic electroluminescence layer. The organic electroluminescence display device according to claim 7 , wherein the light emitting layer emits white light from a two-wavelength light source.

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