JP2022012271A - Organic EL display device - Google Patents

Abstract

Kind Code: A1 To provide an organic EL display device free from the problem of color mixture and having higher luminance than when a color filter having a black matrix is formed. Kind Code: A1 In an organic EL display device in which at least an organic EL element 2 and a color filter 3 are provided in this order on a semiconductor substrate 1 on which a drive circuit is formed, each colored pixel is provided between each colored pixel of the color filter. A resin pattern 4 for partitioning pixels is provided, and the maximum transmittance in the wavelength region of 380 nm or more and 780 nm or less in the width direction of the resin pattern is 20% or less, and the wavelength of 380 nm or more and 780 nm or less of the surface of the resin pattern. An organic EL display device 10 characterized by having a minimum reflectance of 15% or more in a region. [Selection drawing] Fig. 1

Description

The present invention relates to an organic electroluminescence (organic Electro-Luminescence, hereinafter referred to as organic EL) display device. More specifically, the present invention relates to an organic EL display device having no color mixing and high brightness.

In recent years, in electronic devices such as mobile phones and personal digital assistants, organic EL, which is a self-luminous element, is used to meet the demand for thinner and lighter weight and curved surface display, which was difficult with the current mainstream liquid crystal display devices. Development and mass production of display devices using the above are in progress. Among them, in order to take advantage of the features of thinness and weight reduction, it is expected to be applied to high-definition and small displays of about 0.5 inch (hereinafter referred to as microdisplays) such as head-mounted displays and electronic viewfinders. ..

The display method of the organic EL display is a method of forming a film of a white light emitting layer and expressing colors such as RGB using a color filter, and a method of expressing colors by depositing a light emitting layer that emits each color such as RGB. There are two main methods. Since the pixels of a microdisplay are fine, it is very difficult to selectively form an RGB light emitting layer. Therefore, a method of using a color filter for the white light emitting layer is positively adopted for the micro display.

As mentioned above, since the pixel size of a micro display is as fine as 1 μm to 3 μm, the conventional method of manufacturing organic EL elements and color filters on separate substrates and bonding them together reduces accuracy and causes color shift. It will occur. Therefore, a method of forming a color filter on an organic EL element has been proposed.

When a color filter is formed on an organic EL display element and separated into red, green, and blue, the light emission from the organic EL element is isotropic. Therefore, when displaying an arbitrary color, the color filter is adjacent to the color filter. There is a problem that color absorption occurs by the pixels and color reproducibility is deteriorated due to color mixing.

In order to solve the above problems, for example, in Patent Document 1, as shown in FIG. 2, an OLED (Organic Light-Emitting Diode) element 2 is formed on a semiconductor substrate 1, and a red color filter 3 is formed on the OLED (Organic Light-Emitting Diode) element 2. A method of forming a black matrix 7 between green and blue pixels is adopted. The cover glass 6 is attached onto the color filter 3 via the adhesive layer 5, so that the organic EL display device 10'is manufactured.

Japanese Unexamined Patent Publication No. 2012-06745

However, the content of the above-mentioned Patent Document 1 is that although the problem of color mixing is solved by the absorption of light by the black matrix, the light emitted from the organic EL element is absorbed by the black matrix, so that the luminous efficiency is lowered and the luminance is reduced. There was a problem that caused a decline.

In order to solve the above problems, it is an object of the present invention to provide an organic EL display device that reduces the problem of color mixing and has higher brightness than when a color filter provided with a black matrix is formed.

The present invention has adopted the following configuration in order to solve the above problems.

One aspect of the present invention is in an organic EL display device in which at least an organic EL element and a color filter are provided in this order on a semiconductor substrate on which a drive circuit is formed.
A resin pattern for partitioning each colored pixel is provided between each colored pixel of the color filter.
The maximum transmittance in the wavelength region of 380 nm or more and 780 nm or less in the width direction of the resin pattern is 20% or less, and the minimum reflectance in the wavelength region of 380 nm or more and 780 nm or less on the surface of the resin pattern is 15% or more. It is a characteristic organic EL display device.

Further, the resin layer is characterized by containing at least titanium oxide.

According to the organic EL display device of the present invention, the color filter layer formed on the organic EL element has a maximum transmittance of 20% or less in the wavelength region of 380 nm to 780 nm instead of the black matrix, and has a maximum transmittance of 380 nm. It has a gray matrix having a reflectance of 15% or more in a wavelength region of about 780 nm. Therefore, it is possible to provide an organic EL display device having no problem of color mixing and having higher brightness than when a black matrix is used.

It is schematic cross-sectional view which shows an example of the organic EL display apparatus provided with the color filter layer using the gray matrix of this invention. It is schematic cross-sectional view which shows an example of the organic EL display apparatus provided with the color filter layer using the conventional gray matrix.

Hereinafter, the color filter and the organic EL display device used in the present invention will be described in detail.

≪Organic EL display device≫
FIG. 1 shows a cross-sectional view of an embodiment of the organic EL display device of the present invention. In the present invention, an OLED element (hereinafter, also referred to as an organic EL element) 2 is formed on a semiconductor substrate 1, and then a color filter 3 provided with a gray matrix 4 is formed on the OLED element 2 and adhered. This is an organic EL display device 10 to which a cover glass 6 is attached via a layer 5. The gray matrix 4 replaces the black matrix conventionally used for color filters. By increasing the reflectance of light at each pixel interface while having a light-shielding property that can prevent color mixing due to adjacent colored pixels, it is possible to suppress the light emitted from the organic EL element from being absorbed by the gray matrix 4. By doing so, it has a function to improve the brightness.

The organic EL layer of the organic EL element 2 according to the present invention can be formed of a single organic light emitting layer containing a light emitting substance or a multilayer having other layers formed therein. When formed in multiple layers, for example, a general hole transport layer, an electron transporting organic light emitting layer, a three-layer structure in which electron transport layers are sequentially laminated, a hole (electron) injection layer, and a hole ( A multi-layer structure may be provided in which a layer for separating the electron) transport layer and the injection function and the transport function is provided, or a layer for blocking hole (electron) transport is provided.

<Semiconductor substrate>
The semiconductor substrate 1 is a semiconductor substrate on which a drive circuit for driving the organic EL element 2 is formed. The drive circuit may be a semiconductor circuit in which a silicon wafer is manufactured by a wafer process, or a TFT (Thin Film Transistor) circuit manufactured by forming a thin film transistor using a silicon thin film on the surface of a silicon wafer or a glass substrate. There may be.

<Organic EL element>
In the organic EL element 2 used in the organic EL display device 10 of the present invention, the laminate in which the anode, the organic layer, and the cathode are laminated in order from the substrate (semiconductor substrate 1) side is a barrier layer that does not allow water vapor, oxygen gas, or the like to permeate. It is a composition covered with. The organic EL element 2 shown in FIG. 1 illustrates a case where the organic EL element 2 is configured as a so-called top emission type in which the light emitted by the organic EL element 2 is taken out from the side opposite to the substrate.

Next, a detailed configuration of each part constituting these organic EL elements 2 will be described in the order of a substrate, an anode, a cathode paired with the anode, and an organic layer sandwiched between these anodes and the cathode.

(anode)
The anode is provided on the substrate and is composed of a conductive material having a large work function. Conductive materials with a large work function include, for example, nickel, silver, gold, platinum, palladium, selenium, rhodium, ruthenium, iridium, renium, tungsten, molybdenum, chromium, tantalum, niobium and alloys thereof, or tin oxide ( SnO ₂ ), indium tin oxide (ITO: Indium tin oxide), zinc oxide, titanium oxide and the like.

(cathode)
The cathode is constructed using a conductive material with a small work function. As such a conductive material, for example, an alloy of an active metal such as Li, Mg, or Ca and a metal such as Ag, Al, or In, or a structure in which these are laminated can be used. Further, the structure may be such that a compound layer of an active metal such as Li, Mg, Ca and the like and a halogen such as fluorine and bromine, oxygen and the like is thinly inserted between the organic layer and the organic layer.

The anode and cathode are patterned into a shape suitable for the driving method of the display device composed of the organic EL element. For example, when the drive system of the organic EL display device is a simple matrix type, the anode and the cathode are formed in a striped shape intersecting each other, and the intersecting portion thereof becomes an organic EL element.

(Organic layer)
The organic layer of the organic EL element used in the organic EL display device of the present invention has at least a white light emitting layer, but is usually composed of a plurality of organic layers. For example, it has a charge injection layer such as a hole injection layer and an electron injection layer, a hole transport layer that transports holes to a white light emitting layer, and a charge transport layer such as an electron transport layer that transports electrons to a white light emitting layer.

As the white light emitting layer according to the present invention, known ones can be used as long as white light emission can be obtained. As for the emission characteristics of white, it is sufficient that at least three regions, a red region (600 nm to 780 nm), a green region (475 nm to 600 nm), and a blue region (380 nm to 475 nm), have light emission that becomes white by additive color mixing. The number of emission peaks does not necessarily need to be three or more, and for example, even two emission peaks may have emission in the above region. However, in order to obtain a wide color reproducibility, it is preferable to use a white light emitting layer having three or more emission peaks, and more preferably, there is an emission peak in one or more of the above three color regions.

The material constituting such a white light emitting layer is not particularly limited as long as it emits fluorescence or phosphorescence. Further, the light emitting material may have hole transporting property and electron transporting property. Examples of the light emitting material include a dye-based material, a metal complex-based material, and a polymer-based material.

Examples of the dye-based luminescent material include cyclopendamine derivatives, tetraphenylbutadiene derivatives, triphenylamine derivatives, oxadiazol derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, silol derivatives, and thiophene ring compounds. Examples thereof include a pyridine ring compound, a perinone derivative, a perylene derivative, an oligothiophene derivative, a trifmanylamine derivative, an oxadiazole dimer, a pyrazoline dimer and the like.

Examples of the metal complex-based luminescent material include aluminum quinolinol complex, benzoquinolinol beryllium complex, benzoxazole zinc complex, benzothiazole zinc complex, azomethyl zinc complex, porphyrin zinc complex, and europium complex, or Al, Zn, as a central metal. Examples thereof include metal complexes having Be and the like or rare earth metals such as Tb, Eu and Dy, and having oxadiazole, thiadiazol, phenylpyridine, phenylbenzoimidazole, quinoline structure and the like as ligands.

Examples of the polymer-based light-emitting material include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and the above-mentioned dye-based materials and metal complex-based materials. Examples thereof include polymerized ones.

Examples of the method for forming the white light emitting layer include a vapor deposition method, a printing method, an inkjet method, a spin coating method, a casting method, a dipping method, a bar coating method, a blade coating method, a roll coating method, a gravure coating method, and flexographic printing. A method, a spray coating method, a self-assembling method (alternate adsorption method, self-assembled monolayer method) and the like can be mentioned. In particular, it is preferable to use a vapor deposition method, a spin coating method, and an inkjet method, and the film thickness of the white light emitting layer is usually about 5 nm to 5 μm.

(Hole injection layer)
In the present invention, a hole injection layer may be formed between the white light emitting layer and the anode. This is because the hole injection layer stabilizes the injection of holes into the white light emitting layer and enhances the luminous efficiency. As the material for forming the hole injection layer used in the present invention, a material generally used for the hole injection layer of an organic EL device can be used. Further, the material for forming the hole injection layer may be any material having either hole injection property or electron barrier property.

Materials for forming the hole injection layer include triazole derivative, oxadiazole derivative, imidazole derivative, polyarylalkane derivative, pyrazoline derivative, pyrazolone derivative, phenylenediamine derivative, arylamine derivative, amino-substituted carcon derivative, oxazole derivative, and styrylanthracene. Examples thereof include derivatives, fluorenone derivatives, hydrazone derivatives, stylben derivatives, silazane derivatives, polysilane-based, aniline-based copolymers, and conductive polymer oligomers such as thiophene oligomers.

Further, examples of the material for forming the hole injection layer include a porphyrin compound, an aromatic tertiary amine compound, and a styrylamine compound. The film thickness of the hole injection layer is usually about 5 nm to 1 μm.

(Electron injection layer)
In the present invention, an electron injection layer may be formed between the white light emitting layer and the cathode. This is because by providing the electron injection layer, the injection of electrons into the white light emitting layer is stabilized and the luminous efficiency can be improved.

Examples of the material for forming the electron injection layer used in the present invention include heterocyclic tetracarboxylic acid anhydrides such as nitro-substituted fluorene derivatives, anthraquinodimethane derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, naphthalene perylene, and carbodiimide. Freolenilidene methane derivative, anthraquinodimethane and antron derivative, oxadiazole derivative, thiazole derivative in which the oxygen atom of the oxadiazole ring of the oxadiazole derivative is replaced with sulfur atom, quinoxalin ring known as an electron-withdrawing group. Examples thereof include a quinoxalin derivative having the above, a metal complex of an 8-quinolinol derivative such as tris (8-quinolinol) aluminum, a phthalocyanine, a metallic phthalocyanine, and a distyrylpyrazine derivative.

(Barrier membrane)
Since the material of the light emitting layer of the organic EL element is sensitive to humidity, a barrier film is provided in order to develop moisture resistance. As a barrier membrane for an organic EL element, a barrier membrane made of silicon nitride by a plasma CVD method that can be formed at a low temperature is usually used, but if deterioration of the light emitting layer of the organic EL element can be prevented, nitridation is performed. It does not have to be limited to silicon.

<Color filter>
It is necessary to suppress the color mixing in the pixels of the color filter and suppress the decrease in the luminous efficiency. Therefore, instead of the black matrix that partitions each pixel, a gray matrix is formed, and a colored resin layer is formed in the portion partitioned by the gray matrix to form colored pixels.
The gray matrix needs to have a light-shielding property that blocks light from adjacent pixels and has a function of increasing the reflectance of light at each pixel interface.

(Gray matrix)
The gray matrix is a matrix-like resin pattern composed of a resin layer containing a pigment that can be colored gray.
It is necessary that the maximum transmittance in the wavelength region of 380 nm to 780 nm in the width direction in the plan view of the resin pattern is 20% or less. When the maximum transmittance is 20% or less, it is possible to prevent the light emitted from the organic EL element corresponding to a certain pixel from leaking to the adjacent pixel through the resin pattern. Moreover, it is necessary that the minimum reflectance in the wavelength region of 380 nm to 780 nm on the side surface of the resin pattern is 15% or more. When the minimum reflectance is 15% or more, it is possible to prevent the light emitted from the organic EL element from being absorbed when it is incident on the side surface of the resin pattern. Incidentally, the minimum reflectance in the same wavelength region of the black matrix is about 4%.

Titanium oxide can be preferably used as the gray pigment for coloring the gray matrix.
-Titanium oxide Titanium oxide has three crystal forms of anatase type, rutile type and blue kite type, but in this embodiment, at least one of anatase type, which tends to have a small particle size, and rutile type, which has high coloring power. May be contained.

Anatase-type titanium oxide is preferable in that it has a higher reflectance on the short wavelength side in the ultraviolet visible light region and exhibits a paler hue as compared with rutile-type. However, since anatase-type titanium oxide has photocatalytic activity, when it is formed as a decorative layer of a touch panel, it discolors the resin or the like in the composition when it is irradiated with light such as sunlight for a long period of time. There is a fear. Therefore, the rutile type is often used.

The rutile-type titanium oxide has inferior reflectance on the short wavelength side in the ultraviolet visible light region as compared with the anatase-type whiteness, but has almost no photoactivity. Therefore, deterioration such as yellowing of the resin can be suppressed, and a stable decorative layer can be obtained.

Further, among the rutile-type titanium oxides, those produced by the chlorine method are preferable in terms of whiteness and dispersion stability. Further, by mixing titanium oxide with an extender pigment of a natural mineral such as mica or talc, a coating film having high brightness, concealing property and good flatness can be obtained.

The titanium oxide according to the present embodiment may be surface-treated for the purpose of improving dispersion stability and reflectance, and may be surface-treated with alumina in that the reflectance can be further improved and whiteness can be obtained. Is preferable. Examples of titanium oxide surface-treated with alumina include TIPURE R-100, TIPURE R-101, TIPURE R-102, TIPURE R-103, TIPURE R-104, TIPURE R-105, and TIPURE R-108, manufactured by DuPont. TIPURE R-706, TIPURE R-900, TIPURE R-902, TIPURE R-931, TIPURE R-960, TITANIX JR-300, TITANIX JR-403, TITANIX JR-405, TITANIX JR-600A, ITAN -600E, TITANIX JR-602, TITANIX JR-602S, TITANIX JR-603, TITANIX JR-805, TITANIX JA-4, Sakai Chemical Industry Co., Ltd. TITON R-5N, TITON R-7E, TITON R-21, TITON -25, TITON R-32, TITON R-42, TITON R-44, TITON R-45M, TITON R-49S, TITON R-61N, TITON R-62N, TITON GTR-100, TITON GTR-300, Ishihara Sangyo TIPAQUE CR-50, TIPAQUE CR-57, TIPAQUE CR-58, TIPAQUE CR-60, TIPAQUE CR-63, TIPAQUE CR-67, TIPAQUE CR-80, TIPAQUE CR-85, TIPAQUE CR-90, TIPAQUE 93, TIPAQUE CR-95, TIPAQUE CR-97, TIPAQUE UT771, TIPAQUE R-550, TIPAQUE R-630, TIPAQUE R-670, TIPAQUE R-680, TIPAQUE R-780, TIPAQUE R-830, TIPA TIPAQUE A-220 and the like can be used.

In addition to titanium oxide surface-treated with alumina, it may be further surface-treated with other organic substances or inorganic substances. For example, TIPAQUE R-60-2 (manufactured by Ishihara Sangyo Co., Ltd.) surface-treated with alumina and organic substances, alumina. TIPAQUE R-57, R-67, R-97 (manufactured by Ishihara Sangyo Co., Ltd.), TITON R-61N, TITON GTR-100, TITON GTR-300, etc. (manufactured by Sakai Chemical Industry Co., Ltd.) surface-treated with zirconia are also preferable. Can be used.

In these titanium oxides, the titanium oxides are aggregated with each other as they are. Therefore, distributed processing is required. A dispersant and a solvent are added to titanium oxide to form a mill base, which can be dispersed by a method such as a ball mill, a sand mill, a bead mill, a three-roll, a paint shaker, an ultrasonic wave, or a bubble homogenizer. It is also possible to combine two or more of these processing methods. As the dispersant, a resin or a known dispersant can be used.

The titanium oxide content according to the present embodiment is preferably in the range of 30% to 60% (weight ratio) of the total solid content of the gray matrix. If the content is less than 30%, the amount of the resin in the composition is large, so that it is not possible to obtain a coating film having a high reflectance while suppressing the transmittance in the visible light region.

As an example other than titanium oxide, any white inorganic pigment such as ZrO and alumina can be suitably used.

A photosensitive gray resist may be prepared by using the gray pigment described above. For example, in a photosensitive black resist for producing a black matrix, a photosensitive gray resist can be produced by using a gray pigment instead of a black pigment such as carbon black. Using this, it is possible to form a gray matrix on a desired substrate by performing a manufacturing process similar to that for producing a black matrix.

(Colored pixel)
Next, the components of the colored photosensitive resist for producing the colored pixels of the color filter 3 will be described. Specifically, red pigments, green pigments, yellow pigments, blue pigments, purple pigments, binder resins, photopolymerizable monomers, photopolymerization initiators, and heat curing used for each of the red, green, and blue colored pixels. Sex monomers, chain transfer agents, acid generators, solvents, etc. will be described.

-Red pigment As a red pigment, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 37, 38, 41, 47, 48, 48: 1, 48: 2, 48: 3, 48: 4, 49, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2, 53, 53: 1, 53: 2, 53: 3, 57, 57: 1, 57: 2, 58: 4, 60, 63, 63: 1, 63: 2, 64, 64: 1, 68, 69, 81, 81: 1, 81: 2, 81: 3, 81: 4, 83, 88, 90: 1, 101, 101: 1, 104, 108, 108: 1, 109, 112, 113, 114, 122, 123, 144, 146, 147, 149, 151, 166, 168, 169, 170, 172, 173, 174, 175, 176, 177, 178, 179, 181, 184, 185, 187, 188, 190, 193, 194, 200, 202, 206, 207, 208, 209, 210, 214, 216, 220, 221, 224, 230, 231, 232, 233, 235, 236, 237, 238, 239, 242, 243, 245, 247, 249, 250, 251, 253, 254, 255, 256, 257, 258, 259, 260, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276 and the like.
Examples of the orange pigment include C.I. I. Pigment Orange 36, 38, 43, 51, 55, 59, 61 and the like.
Among these, C.I. I. Pigment Red 254, C.I. I. It is particularly preferred to use Pigment Red 177.

-Green pigment As a green pigment, for example, C.I. I. Pigment Greens 1, 2, 4, 7, 8, 10, 13, 14, 15, 17, 18, 19, 26, 36, 45, 48, 50, 51, 54, 55 or 58 can be mentioned. Among these, C.I. I. Pigment Green 7, 36 or 58, more preferably C.I. I. Pigment Pigment Green 36, C.I. I. Pigment Pigment Green 58.

-Yellow pigment Examples of the yellow pigment include C.I. I. Pigment Yellow 1, 1: 1, 2, 3, 4, 5, 6, 9, 10, 12, 13, 14, 16, 17, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1,37,37: 1,40,41,42,43,48,53,55,61,62,62: 1,63,65,73,74,75,81,83,87,93,94, 95, 97, 100, 101, 104, 105, 108, 109, 110, 111, 116, 117, 119, 120, 126, 127, 127: 1, 128, 129, 133, 134, 136, 138, 139, 142, 147, 148, 150, 151, 153, 154, 155, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 172, 173, 174, 175, 176, 180, 181, 182, 183, 184, 185, 188, 189, 190, 191, 191: 1, 192, 193, 194, 195, 196, 197, 198, 199, 200, 202, 203, 204, 205, 206, 207, 208 and the like can be mentioned. Among these, C.I. I. Pigment Yellow 83, 117, 129, 138, 139, 150, 154, 155, 180, or 185, more preferably C.I. I. Pigment Yellow 138, 139, 150, or 185, more preferably C.I. I. Pigment Yellow 139, C.I. I. Pigment Yellow 185.

-Blue pigment As a blue pigment, for example, C.I. I. Pigment Blue 1, 1: 2, 9, 14, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 19, 25, 27, 28, 29, 33, 35, 36, 56, 56: 1, 60, 61, 61: 1, 62, 63, 66, 67, 68, 71, 72, 73, 74, 75, 76, 78, 79 and the like can be mentioned. Among these, C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, or 15: 6, more preferably C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 15: 6.

-Purple pigment As a purple pigment, for example, C.I. I. Pigment Violet 1, 1: 1, 2, 2: 2, 3, 3: 1, 3: 3, 5, 5: 1, 14, 15, 16, 19, 23, 25, 27, 29, 31, 32, 37, 39, 42, 44, 47, 49, 50 and the like can be mentioned. Among these, C.I. I. Pigment Violet 19 or 23, more preferably C.I. I. Pigment Violet 23.

-Binder resin As the binder resin, an alkali-soluble non-photosensitive transparent resin and a photosensitive transparent resin can be used.
The alkali-soluble non-photosensitive transparent resin is a transparent resin having a property of dissolving in an alkaline aqueous solution and having no photopolymerizability, and specifically, as such an alkali-soluble non-photosensitive resin, , Acrylic resin with acidic functional group, α-olefin- (anhydrous) maleic acid copolymer, styrene- (anhydrous) maleic acid copolymer, styrene-styrene sulfonic acid copolymer, ethylene- (meth) acrylic acid copolymer Examples thereof include coalescing, isobutylene- (anhydrous) maleic acid copolymer and the like. Among them, at least one selected from an acrylic resin having an acidic functional group, an α-olefin- (anhydrous) maleic acid copolymer, a styrene- (anhydrous) maleic acid copolymer and a styrene-styrene sulfonic acid copolymer. Resin is preferably used.

The photosensitive transparent resin is an ethylene unsaturated compound obtained by reacting a linear polymer having a reactive functional group with a (meth) acrylic compound having a substituent capable of reacting with the reactive functional group, silicic acid, or the like. Examples thereof include a resin in which a heavy bond is introduced into the linear polymer. Further, an ethylene unsaturated double bond is formed by reacting a (meth) acrylic compound having a reactive functional group, silicic acid, or the like with a linear polymer having a substituent capable of reacting with the reactive functional group. Examples thereof include the resin introduced into the state polymer. Examples of the reactive functional group include a hydroxyl group, a carboxyl group and an amino group, and examples of the substituent capable of reacting with the reactive functional group include an isocyanate group, an aldehyde group and an epoxy group.
Further, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is used as a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. The one half-esterified with the above can also be used as a photosensitive resin.

-Photopolymerizable Monomer As the photopolymerizable monomer, a polyfunctional urethane acrylate obtained by reacting a (meth) acrylate having a hydroxyl group with a polyfunctional isocyanate can be used.
Examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropanetri (meth) acrylate, and pentaerythritol tri (pentaerythritoltri (meth) acrylate. Meta) Acrylate, Ditrimethylol Propanetri (Meta) Acrylate, Dipentaerythritol Penta (Meta) Acrylate, Dipentaerythritol Hexa (Meta) Acrylate, Dipentaerythritol Ethylene Oxide Modified Penta (Meta) Acrylate, Dipenta Erythritol Propylene Oxide Modified Penta (Meta) acrylate, dipentaerythritol caprocalactone-modified penta (meth) acrylate, glycerol acrylate methacrylate, glycerol dimethacrylate, 2-hydroxy-3-acryloylpropylmethacrylate, reaction product of epoxy group-containing compound and carboxy (meth) acrylate, Examples thereof include hydroxyl group-containing polyol polyacrylate.
Examples of the polyfunctional isocyanate include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethylene diisocyanate, isophorone diisocyanate, and polyisocyanate.

-Photopolymerization initiator As the photopolymerization initiator, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1 -On, 1-hydroxycyclohexylphenylketone, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholino) Acetphenone-based photopolymerization initiators such as phenyl) -butane-1-one, benzoin-based photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl dimethyl ketal, benzophenone, benzoyl benzoic acid, and benzoyl. Methyl benzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylicized benzophenone, 4-benzoyl-4'-methyldiphenylsulfide and other benzophenone photopolymerization initiators, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, Thioxanthone-based photopolymerization initiators such as 2,4-diisopropylthioxanthone, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-) Methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis ( Trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphtho-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl ( A triazine-based photopolymerization initiator such as 4'-methoxystyryl) -6-triazine, a borate-based photopolymerization initiator, a carbazole-based photopolymerization initiator, an imidazole-based photopolymerization initiator, and the like are used.

The above photopolymerization initiator may be used alone or in combination of two or more, and as a sensitizer, α-acyloxyester, acylphosphine oxide, methylphenylglycilate, benzyl, 9,10-phenanslenquinone may be used. , Phenylquinone, Ethylanthraquinone, 4,4'-diethylisophthalofenone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 4,4'-diethylaminobenzophenone and the like. It can also be used together.

-Thermosetting monomer As the thermosetting monomer, it is preferable to use a polyfunctional epoxy compound having two or more functionalities. For example, an epoxy compound such as a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a phenol novolac type epoxy compound, a cresol novolac type epoxy compound, an aliphatic epoxy compound, or a bisphenol fluorene type epoxy compound can be mentioned. ..
Specifically, low molecular weight epoxy such as ethylene glycol diglycidyl ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether. Examples include compounds. Product names include EX-810, EX-830, EX-611, EX-421, EX-512, EX-521, EX-611, EX-614, EX-622, EX-314, and EX manufactured by Nagase ChemteX. -321 and EX-411 are mentioned.
Further, a part of the polyfunctional epoxy compound may be replaced with a polyfunctional oxetane compound. The oxetane compound is, for example, an oxetan such as a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a phenol novolac type epoxy compound, a cresol novolac type epoxy compound, an aliphatic epoxy compound, or a bisphenol fluorene type epoxy compound. Examples include compounds.

-Chain transfer agent The colored resin composition can contain a polyfunctional thiol that acts as a chain transfer agent. The amount of the polyfunctional thiol used is preferably 0.1 to 30% by weight, more preferably 1 to 20% by weight, based on the total solid content of the colored resin composition. If it is less than 0.1% by mass, the effect of adding the polyfunctional thiol is insufficient, and if it exceeds 30% by mass, the sensitivity is too high and the resolution is lowered. In addition, since thiol also functions as a curing agent for thermosetting components, it acts to promote photoreactions and thermal reactions, and thus plays a very important role in the present invention.

The polyfunctional thiol may be a compound having two or more thiol groups, for example, hexanedithiol, decandithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene. Glycolbisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropanetristhioglycolate, trimethylolpropanetristhiopropionate, trimethylolpropanetris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, tristrimercaptopropionate (2-hydroxyethyl) isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercapto-s-triazine, 2- (N, N-) Dibutylamino) -4,6-dimercapto-s-triazine and the like can be mentioned. These polyfunctional thiols can be used alone or in admixture of two or more.

-Photoacid generator The composition of the present invention contains a compound that generates an acid by irradiation with active light or radiation (hereinafter, also referred to as a photoacid generator). By advancing the reaction between the acid generated by irradiation with radiation and epoxy and oxetane, it becomes possible to cure the coating film at a low temperature without performing conventional high-temperature firing.

The photoacid generator is preferably a compound that is sensitive to active light having a wavelength of 300 nm or more, preferably 300 to 450 nm, and generates an acid, but is not limited to its chemical structure. In addition, a photoacid generator that is not directly sensitive to active light with a wavelength of 300 nm or more is also sensitized if it is a compound that is sensitive to active light or radiation with a wavelength of 300 nm or more and generates an acid when used in combination with a sensitizer. It can be preferably used in combination with an agent. For example, as the (C) photoacid generator, a compound that generates an organic acid such as an onium salt, a sulfonic acid, a bis (alkylsulfonyl) imide, or a tris (alkylsulfonyl) methide is preferable. Further, as the (C) photoacid generator, trichloromethyl-s-triazines, sulfonium salts, iodonium salts, quaternary ammonium salts, diazomethane compounds, imide sulfonate compounds, oxime sulfonate compounds and the like are also preferable.

-Solute As a solvent, methanol, ethanol, ethyl cellosolve, ethyl cellosolve acetate, jigglime, cyclohexanone, ethylbenzene, xylene, Isoa mill acetate, n-amyl acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether. , Propropylene glycol monoethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, triethylene glycol, triethylene glycol monomethyl ether, tri Ethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether, triethylene glycol monoethyl ether acetate, liquid polyethylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monoethyl Examples include ether acetate, lactic acid ester, ethylethoxypupopionate and the like.

<Manufacturing method of color filter>
The photosensitive coloring resin composition used for forming the pixels of the color filter according to the present invention contains at least a pigment, a photopolymerizable monomer, a photopolymerization initiator, and a surfactant, and can form a pattern by a photolitho method. If so, it is not particularly limited.

The organic EL element is formed on the semiconductor substrate on which the drive circuit is formed, and the color filter is formed on the substrate on which the flattening film is formed on the barrier film of the organic EL element.

As a specific forming method, first, a photosensitive colored resin composition for forming a gray matrix is applied onto a substrate by using a coating technique such as a spin coating method or a die coating method, and dried. Next, a gray matrix is formed by exposure and development via a predetermined photomask. Next, the first color photosensitive coloring resin composition is applied and dried. Next, the colored pixels of the first color are formed by exposure and development via a predetermined photomask. Similarly, a color filter is formed by forming colored pixels for the second and subsequent colors.

Then, if necessary, a flattening film is formed on the color filter to smooth the surface of the color filter.

<Manufacturing method of organic EL display device>
By forming an organic EL element on the semiconductor substrate on which the drive circuit is formed as described above, and further adhering the cover glass on the substrate on which the color filter is formed, the cover glass is attached via the adhesive layer. An organic EL display device 10 as illustrated in FIG. 1 can be obtained.

Hereinafter, the present invention will be described in more detail with reference to examples and the like, but the present invention is not limited to these examples.

<Example 1>
<Manufacturing of organic EL element substrate>
A TFT layer was formed on a silicon substrate using a known TFT manufacturing method. Further, a white organic EL element was formed on the TFT layer using a known organic EL manufacturing method, and then silicon nitride was coated by a plasma CVD method to form an organic EL element substrate.

<Preparation of colored resin composition>
Next, the colored resin composition for the gray matrix that forms the gray matrix on the organic EL element substrate, the red colored resin composition that forms the colored pixels, the green colored resin composition, and the blue colored resin composition are as follows. Made.

(Pigment)
As the coloring agent used in the coloring resin composition for gray matrix, rutyl-type titanium oxide was added as a gray pigment to the acrylic photosensitive resin obtained by adding an acrylic monomer, a photopolymerization initiator, etc. to the acrylic resin. A photosensitive colored resin composition was used.
The content of rutile-type titanium oxide in this photosensitive colored resin composition is the maximum transmittance of a coating film obtained by applying and drying a colored resin composition for gray matrix on a glass substrate, which corresponds to the thickness of the great matrix between pixels. Is a value adjusted so that 10% and the minimum reflectance of the surface are 37% (Gray 1).

(Pigment)
The following colorants were used as the colorants used in the red colored resin composition.
Red pigment: C.I. I. Pigment Red 254
(BASF's "Ilgar for Red B-CF")
Yellow pigment: C.I. I. Pigment YELlow 139
(BASF's "Pariotor YELlow L 2146HD")

A red colored resin composition was prepared using each pigment.

(Adjustment of red colored resin composition)
After uniformly stirring and mixing the mixture having the following composition, the mixture was dispersed in a sand mill for 5 hours using a glass bead having a diameter of 1 mm, and then filtered through a filter of 5 μm to prepare a dispersion of a red pigment.
Red pigment: C.I. I. Pigment Red 254: 78 parts by weight Yellow pigment: C.I. I. Pigment YELlow 139: 22 parts by weight Acrylic varnish (solid content 20%): 215 parts by weight

Then, the mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 5 μm filter to obtain a red colored material (R-1).

Using the above-mentioned coloring material, a red photosensitive coloring resin composition was prepared so as to have the formulation shown in Table 1 (RR-1).

(Pigment)
The following colorants were used as the colorants used in the green color resin composition.
Green pigment: C.I. I. Pigment Green 58
("FASTOGEN (registered trademark) GREEN A110" manufactured by DIC Corporation)
Yellow pigment: C.I. I. Pigment YELlow 185
(BASF "Pariodol® YELlow L 1155")
A green colored resin composition was prepared using each pigment.

(Adjustment of green colored resin composition)
After uniformly stirring and mixing the mixture having the following composition, the mixture was dispersed in a sand mill for 5 hours using a glass bead having a diameter of 1 mm, and then filtered through a filter of 5 μm to prepare a dispersion of a green pigment.
Green pigment: C.I. I. Pigment Green 58: 65 parts by weight Yellow pigment: C.I. I. Pigment YELlow 185: 35 parts by weight Acrylic varnish (solid content 20%): 215 parts by weight Then, the mixture having the following composition is stirred and mixed so as to be uniform, and then filtered through a 5 μm filter to form a green coloring material (G-1). ) Was obtained.
Using the above-mentioned coloring material, a blue photosensitive coloring resin composition was prepared so as to have the formulation shown in Table 1 (GR-1).

(Pigment)
The following colorants were used as the colorants used in the colored resin composition.
Blue pigment: C.I. I. Pigment Blue 15: 6
("LIONOL BLUE ES" manufactured by Toyo Color Co., Ltd.)
Purple pigment: C.I. I. Pigment Violet 23
("LIONOGEN VIOLET RL" manufactured by Toyo Color Co., Ltd.)
A blue colored resin composition was prepared using each pigment.

(Adjustment of blue colored resin composition)
After uniformly stirring and mixing the mixture having the following composition, the mixture was dispersed in a sand mill for 5 hours using a glass bead having a diameter of 1 mm, and then filtered through a filter of 5 μm to prepare a dispersion of a blue pigment.
Blue pigment: C.I. I. Pigment Blue 15: 6: 63 parts by weight Purple pigment: C.I. I. Pigment Violet 23: 37 parts by weight Acrylic varnish (solid content 20%): 215 parts by weight Then, the mixture having the following composition is stirred and mixed so as to be uniform, and then filtered through a 5 μm filter to form a blue coloring material (B-1). ) Was obtained.

Using the above-mentioned coloring material, a blue photosensitive coloring resin composition was prepared so as to have the formulation shown in Table 1 (BR-1).

<Manufacturing of color filters and organic EL display devices>
A transparent resin composition for a flattening film was applied onto the produced organic EL element substrate with a spinner so that the cured film thickness was 0.1 μm. Then, it was heated at 100 ° C. for 10 minutes using a heating oven to cure, and the formation of the flattening film was completed.

A gray photosensitive resin composition is applied on a flattening film of an organic EL element substrate with a spinner so that the cured finished film thickness is 1.2 μm, and UV exposure, alkaline development, washing and drying are performed via a pattern mask. Through the steps, a gray matrix layer (Gray) of the color filter was formed. Then, it was heated at 80 ° C. for 10 minutes using a heating oven to cure, and the formation of the gray matrix layer (Gray 1) of the color filter was completed.

A green photosensitive resin composition is applied on a gray matrix layer formed on an organic EL element substrate with a spinner so that the cured film has a thickness of 1.2 μm, and is exposed to ultraviolet rays and developed by alkali through a pattern mask. The green layer (Green2) of the color filter was temporarily formed through the washing and drying steps. Then, it was heated at 80 ° C. for 10 minutes using a heating oven to cure, and the formation of the green layer (Green2) of the color filter was completed.

Next, in the same manner as in the method for forming the green layer (Green2) of the color filter described above, the red photosensitive resin composition is applied with a spinner so that the cured finished film thickness is 1.2 μm, and a pattern mask is applied. The green layer (Red1) of the color filter was temporarily formed through the steps of ultraviolet exposure, alkaline development, washing with water, and drying. Then, it was heated at 80 ° C. for 10 minutes using a heating oven to cure, and the formation of the red layer (Red1) of the color filter was completed.

Further, in the same manner as in the method for forming the green layer (Green2) of the color filter described above, the blue photosensitive resin composition is applied with a spinner so that the cured finished film thickness is 1.2 μm, and the film is passed through a pattern mask. The red layer (Blue3) of the color filter was temporarily formed through the steps of ultraviolet exposure, alkaline development, washing with water and drying. Then, it was heated at 80 ° C. for 10 minutes using a heating oven to cure, and the formation of the blue layer (Blue3) of the color filter was completed to prepare a color filter.

After forming the green, red, and blue layers, they were bonded to the cover glass using the sealing agent Stract Bond XMF-T107 (manufactured by Mitsui Chemicals, Inc.) to prepare an organic EL display device.

<Example 2>
Example 1 except that the coloring material forming the gray matrix in the process of forming the color filter was used to form Gray 2 in which the content of titanium oxide was reduced from Gray 1 so as to have a maximum transmittance of 15% and a minimum reflectance of 33%. An organic EL display device was manufactured in the same manner as in the above.

<Example 3>
Example 1 except that the coloring material for which the gray matrix is formed in the color filter forming step is formed with the titanium oxide content further reduced from Gray2 so as to have a maximum transmittance of 20% and a minimum reflectance of 30%. An organic EL display device was manufactured in the same manner as in the above.

<Example 4>
Example 1 except that the coloring material to be formed in the gray matrix in the process of forming the color filter was formed into Gray 4 in which the titanium oxide content was further reduced from Gray 3 so as to have a maximum transmittance of 40% and a minimum reflectance of 15%. An organic EL display device was manufactured in the same manner as in the above.

<Comparative Example 1>
An organic EL display device was produced in the same manner as in Example 1 except that a black matrix was formed instead of forming a gray matrix in the color filter forming step.

The gray matrix prepared in Examples 1 to 4; the maximum transmittance and the minimum reflectance in the wavelength region of 380 nm or more and 780 nm or less of the gray matrix prepared in Gray 1 to Gray 4 and Comparative Example 1 are summarized in Table 2.

<Brightness evaluation>
The chromaticity at the time of red display, green display, and blue display in the organic EL display devices of Example 1 and Comparative Example 1 was measured using a "spectral radiance meter CS-1000" manufactured by Olympus Corporation.

All three color pixels of red, green, and blue are lit and displayed, and those with a brightness of 330 cd / m ² or more when displayed in white are ◎, those with a brightness of 300 cd / m ² or more and less than 330 cd / m ² are 〇, 280 cd /. Those having m ² or more and less than 300 cd / m ² were evaluated as Δ, and those having less than 280 cd / m ² were evaluated as ×.

The results of the brightness evaluation are summarized in Table 3. Comparative Example 1 used a black matrix and was marked with x. On the other hand, in Examples 1 to 3, instead of the black matrix, the gray matrix of Gray1, Gray2, and Gray3 are used, respectively. Therefore, all of them became 〇, and it was possible to confirm the effect of improving the relative luminance in the red, green, and blue displays. It is considered that the reflection of light within the same pixel by the gray matrix can suppress the loss of light absorbed by the adjacent pixels and the black matrix. Regarding Example 4, the minimum reflectance was 25%, which was the smallest value among Examples 1 to 4, so that the value was Δ. However, compared to Comparative Example 1 using a black matrix having a minimum reflectance of 4%. It was confirmed that high brightness could be obtained.

<Color mixing evaluation>
The organic EL display devices of Examples 1 to 4 and Comparative Example 1 were turned on in white, and the degree of color change was visually observed when observed from an oblique direction.
Judgment was carried out as 〇 (no color mixing) for those that did not show color change even when observed from an oblique direction, and × (with color mixing) for those that seemed to have changed.

The results of the color mixing evaluation are summarized in Table 3. As shown in Table 3, it can be seen that in Examples 1 to 4 and Comparative Example 1, all of the organic EL display devices have good color mixing evaluation (◯) and excellent visibility. On the other hand, for reference, in a color filter that does not have a black matrix or a gray matrix, the brightness is not reduced by the black matrix, but the light emitted from the organic EL element is transmitted, and the influence of the light transmitted through the adjacent pixels is affected. It is thought that the color is mixed.

From the above results, in the organic EL display device provided with the color filter using the gray matrix of the present invention, it is possible to increase the brightness as compared with the case of using the black matrix, and it is possible to prevent color mixing. , It is possible to improve the visibility.

The present invention can be used as an organic EL display device for electronic devices such as smart glasses, head-mounted displays, and electronic viewfinders.

1 ... Semiconductor substrate 2 ... OLED element or organic EL element 3 ... Color filter 4 ... Gray matrix 5 ... Adhesive layer 6 ... Cover glass 7 ... Black matrix 10, 10'・ ・ ・ Organic EL display device

Claims (2)

In an organic EL display device in which at least an organic EL element and a color filter are provided in this order on a semiconductor substrate on which a drive circuit is formed.
A resin pattern for partitioning each colored pixel is provided between each colored pixel of the color filter.
The maximum transmittance in the wavelength region of 380 nm or more and 780 nm or less in the width direction of the resin pattern is 20% or less, and the minimum reflectance in the wavelength region of 380 nm or more and 780 nm or less on the surface of the resin pattern is 15% or more. A featured organic EL display device. The organic EL display device according to claim 1, wherein the resin pattern contains at least titanium oxide.

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